TY  - CONF
AU  - Adžić Bukvić, Marija
AU  - Dragić, Milorad
AU  - Zarić Kontić, Marina
AU  - Nedeljković, Nadežda
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11055
AB  - The antibiotic streptozotocin (STZ) is an FDA approved for pancreatic neuroendocrine tumors. It has also been used for rat model of diabetes induction, where it causes a progressive increase in BBB permeability, and activates glial cells. In intracerebroventricular injected STZ-induced AD model, the abnormal mitochondrial morphology, decrease ATP biosynthesis, accumulation of reactive oxygen species (ROS), disrupted homeostasis of brain insulin signaling and defect in cerebral glucose metabolism were observed. Streptozotocin has been used to induce mitochondrial, endoplasmic and in general oxidative stress in neuronal cells and in astrocytoma C6 cell line in vitro. Our study aimed to analyze the STZ effects on primary rat astrocyte cultures. The testing of STZ concentration range (1, 5, 10 and 20 mM) in MTT assay, excluded the 20 mM STZ which evoked a significant decrease in mitochondrial activity in astrocytes. As ROS are the most pronounced parameters elevated in STZ disease modeling, we analyzed GSH, SH groups and MDA 24 h after the STZ application. The 10 mM STZ lowered GSH levels, while SH groups showed a STZ dose dependent decrease. On the other hand, MDA showed a slight, but not significant increase following STZ concentration increase. Moreover, we investigated changes in the purinergic signaling system. Our results show the drop of CD73 activity 24 h after the 10 mM STZ treatment, accompanied by CD73 immunofluorescence decrease on the astrocyte membranes. Similarly, nucleoside triphosphate diphosphohydrolase 2 (NT2) was downregulated on astrocyte membranes. These results encourage further analysis of the P1 and P2 purinergic receptors
PB  - Belgrade : Serbian Neuroscience Society
C3  - 8th Congress of Serbian neuroscience society with international participation : the book of abstracts; 31 May – 2 June; Belgrade
T1  - Streptozotocin, an FDA approved drug, affects the oxidative stress parameters and purinergic signaling components in primary rat astrocyte cultures
SP  - 102
UR  - https://hdl.handle.net/21.15107/rcub_vinar_11055
ER  - 

@conference{
author = "Adžić Bukvić, Marija and Dragić, Milorad and Zarić Kontić, Marina and Nedeljković, Nadežda",
year = "2023",
abstract = "The antibiotic streptozotocin (STZ) is an FDA approved for pancreatic neuroendocrine tumors. It has also been used for rat model of diabetes induction, where it causes a progressive increase in BBB permeability, and activates glial cells. In intracerebroventricular injected STZ-induced AD model, the abnormal mitochondrial morphology, decrease ATP biosynthesis, accumulation of reactive oxygen species (ROS), disrupted homeostasis of brain insulin signaling and defect in cerebral glucose metabolism were observed. Streptozotocin has been used to induce mitochondrial, endoplasmic and in general oxidative stress in neuronal cells and in astrocytoma C6 cell line in vitro. Our study aimed to analyze the STZ effects on primary rat astrocyte cultures. The testing of STZ concentration range (1, 5, 10 and 20 mM) in MTT assay, excluded the 20 mM STZ which evoked a significant decrease in mitochondrial activity in astrocytes. As ROS are the most pronounced parameters elevated in STZ disease modeling, we analyzed GSH, SH groups and MDA 24 h after the STZ application. The 10 mM STZ lowered GSH levels, while SH groups showed a STZ dose dependent decrease. On the other hand, MDA showed a slight, but not significant increase following STZ concentration increase. Moreover, we investigated changes in the purinergic signaling system. Our results show the drop of CD73 activity 24 h after the 10 mM STZ treatment, accompanied by CD73 immunofluorescence decrease on the astrocyte membranes. Similarly, nucleoside triphosphate diphosphohydrolase 2 (NT2) was downregulated on astrocyte membranes. These results encourage further analysis of the P1 and P2 purinergic receptors",
publisher = "Belgrade : Serbian Neuroscience Society",
journal = "8th Congress of Serbian neuroscience society with international participation : the book of abstracts; 31 May – 2 June; Belgrade",
title = "Streptozotocin, an FDA approved drug, affects the oxidative stress parameters and purinergic signaling components in primary rat astrocyte cultures",
pages = "102",
url = "https://hdl.handle.net/21.15107/rcub_vinar_11055"
}

Adžić Bukvić, M., Dragić, M., Zarić Kontić, M.,& Nedeljković, N.. (2023). Streptozotocin, an FDA approved drug, affects the oxidative stress parameters and purinergic signaling components in primary rat astrocyte cultures. in 8th Congress of Serbian neuroscience society with international participation : the book of abstracts; 31 May – 2 June; Belgrade
Belgrade : Serbian Neuroscience Society., 102.
https://hdl.handle.net/21.15107/rcub_vinar_11055

Adžić Bukvić M, Dragić M, Zarić Kontić M, Nedeljković N. Streptozotocin, an FDA approved drug, affects the oxidative stress parameters and purinergic signaling components in primary rat astrocyte cultures. in 8th Congress of Serbian neuroscience society with international participation : the book of abstracts; 31 May – 2 June; Belgrade. 2023;:102.
https://hdl.handle.net/21.15107/rcub_vinar_11055 .

Adžić Bukvić, Marija, Dragić, Milorad, Zarić Kontić, Marina, Nedeljković, Nadežda, "Streptozotocin, an FDA approved drug, affects the oxidative stress parameters and purinergic signaling components in primary rat astrocyte cultures" in 8th Congress of Serbian neuroscience society with international participation : the book of abstracts; 31 May – 2 June; Belgrade (2023):102,
https://hdl.handle.net/21.15107/rcub_vinar_11055 .

TY  - JOUR
AU  - Zeljković Jovanović, Milica
AU  - Stanojević, Jelena
AU  - Stevanović, Ivana
AU  - Stekić, Anđela
AU  - Bolland, Samuel J.
AU  - Jasnić, Nebojša
AU  - Ninković, Milica
AU  - Zarić Kontić, Marina
AU  - Ilić, Tihomir V.
AU  - Rodger, Jennifer
AU  - Nedeljković, Nadežda
AU  - Dragić, Milorad
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11099
AB  - Parkinson’s disease (PD) is the second most common neurodegenerative disorder characterized by the progressive degeneration of the dopaminergic system, leading to a variety of motor and nonmotor symptoms. The currently available symptomatic therapy loses efficacy over time, indicating the need for new therapeutic approaches. Repetitive transcranial magnetic stimulation (rTMS) has emerged as one of the potential candidates for PD therapy. Intermittent theta burst stimulation (iTBS), an excitatory protocol of rTMS, has been shown to be beneficial in several animal models of neurodegeneration, including PD. The aim of this study was to investigate the effects of prolonged iTBS on motor performance and behavior and the possible association with changes in the NMDAR subunit composition in the 6-hydroxydopamine (6-OHDA)-induced experimental model of PD. Two-month-old male Wistar rats were divided into four groups: controls, 6-OHDA rats, 6-OHDA + iTBS protocol (two times/day/three weeks) and the sham group. The therapeutic effect of iTBS was evaluated by examining motor coordination, balance, spontaneous forelimb use, exploratory behavior, anxiety-like, depressive/anhedonic-like behavior and short-term memory, histopathological changes and changes at the molecular level. We demonstrated the positive effects of iTBS at both motor and behavioral levels. In addition, the beneficial effects were reflected in reduced degeneration of dopaminergic neurons and a subsequent increase in the level of DA in the caudoputamen. Finally, iTBS altered protein expression and NMDAR subunit composition, suggesting a sustained effect. Applied early in the disease course, the iTBS protocol may be a promising candidate for early-stage PD therapy, affecting motor and nonmotor deficits. © 2023 by the authors.
T2  - Cells
T1  - Intermittent Theta Burst Stimulation Improves Motor and Behavioral Dysfunction through Modulation of NMDA Receptor Subunit Composition in Experimental Model of Parkinson’s Disease
VL  - 12
IS  - 11
DO  - 10.3390/cells12111525
ER  - 

@article{
author = "Zeljković Jovanović, Milica and Stanojević, Jelena and Stevanović, Ivana and Stekić, Anđela and Bolland, Samuel J. and Jasnić, Nebojša and Ninković, Milica and Zarić Kontić, Marina and Ilić, Tihomir V. and Rodger, Jennifer and Nedeljković, Nadežda and Dragić, Milorad",
year = "2023",
abstract = "Parkinson’s disease (PD) is the second most common neurodegenerative disorder characterized by the progressive degeneration of the dopaminergic system, leading to a variety of motor and nonmotor symptoms. The currently available symptomatic therapy loses efficacy over time, indicating the need for new therapeutic approaches. Repetitive transcranial magnetic stimulation (rTMS) has emerged as one of the potential candidates for PD therapy. Intermittent theta burst stimulation (iTBS), an excitatory protocol of rTMS, has been shown to be beneficial in several animal models of neurodegeneration, including PD. The aim of this study was to investigate the effects of prolonged iTBS on motor performance and behavior and the possible association with changes in the NMDAR subunit composition in the 6-hydroxydopamine (6-OHDA)-induced experimental model of PD. Two-month-old male Wistar rats were divided into four groups: controls, 6-OHDA rats, 6-OHDA + iTBS protocol (two times/day/three weeks) and the sham group. The therapeutic effect of iTBS was evaluated by examining motor coordination, balance, spontaneous forelimb use, exploratory behavior, anxiety-like, depressive/anhedonic-like behavior and short-term memory, histopathological changes and changes at the molecular level. We demonstrated the positive effects of iTBS at both motor and behavioral levels. In addition, the beneficial effects were reflected in reduced degeneration of dopaminergic neurons and a subsequent increase in the level of DA in the caudoputamen. Finally, iTBS altered protein expression and NMDAR subunit composition, suggesting a sustained effect. Applied early in the disease course, the iTBS protocol may be a promising candidate for early-stage PD therapy, affecting motor and nonmotor deficits. © 2023 by the authors.",
journal = "Cells",
title = "Intermittent Theta Burst Stimulation Improves Motor and Behavioral Dysfunction through Modulation of NMDA Receptor Subunit Composition in Experimental Model of Parkinson’s Disease",
volume = "12",
number = "11",
doi = "10.3390/cells12111525"
}

Zeljković Jovanović, M., Stanojević, J., Stevanović, I., Stekić, A., Bolland, S. J., Jasnić, N., Ninković, M., Zarić Kontić, M., Ilić, T. V., Rodger, J., Nedeljković, N.,& Dragić, M.. (2023). Intermittent Theta Burst Stimulation Improves Motor and Behavioral Dysfunction through Modulation of NMDA Receptor Subunit Composition in Experimental Model of Parkinson’s Disease. in Cells, 12(11).
https://doi.org/10.3390/cells12111525

Zeljković Jovanović M, Stanojević J, Stevanović I, Stekić A, Bolland SJ, Jasnić N, Ninković M, Zarić Kontić M, Ilić TV, Rodger J, Nedeljković N, Dragić M. Intermittent Theta Burst Stimulation Improves Motor and Behavioral Dysfunction through Modulation of NMDA Receptor Subunit Composition in Experimental Model of Parkinson’s Disease. in Cells. 2023;12(11).
doi:10.3390/cells12111525 .

Zeljković Jovanović, Milica, Stanojević, Jelena, Stevanović, Ivana, Stekić, Anđela, Bolland, Samuel J., Jasnić, Nebojša, Ninković, Milica, Zarić Kontić, Marina, Ilić, Tihomir V., Rodger, Jennifer, Nedeljković, Nadežda, Dragić, Milorad, "Intermittent Theta Burst Stimulation Improves Motor and Behavioral Dysfunction through Modulation of NMDA Receptor Subunit Composition in Experimental Model of Parkinson’s Disease" in Cells, 12, no. 11 (2023),
https://doi.org/10.3390/cells12111525 . .

TY  - JOUR
AU  - Dragić, Milorad
AU  - Stekić, Anđela
AU  - Zeljković, Milica
AU  - Zarić Kontić, Marina
AU  - Mihajlović, Katarina
AU  - Adžić, Marija
AU  - Grković, Ivana
AU  - Nedeljković, Nadežda
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10222
AB  - The present study demonstrates altered topographic distribution and enhanced neuronal expression of major adenosine-metabolizing enzymes, i.e. ecto-5ʹ-nucleotidase (eN) and tissue non-specific alkaline phosphatase (TNAP), as well as adenosine receptor subtype A2A in the hippocampus and cortex of male rats from early to late adulthood (3, 6, 12 and 15 months old males). The significant effect of age was demonstrated for the increase in the activity and the protein expression of eN and TNAP. At 15-m, enzyme histochemistry demonstrated enhanced expression of eN in synapse-rich hippocampal and cortical layers, whereas the upsurge of TNAP was observed in the hippocampal and cortical neuropil, rather than in cells and layers where two enzymes mostly reside in 3-m old brain. Furthermore, a dichotomy in A1R and A2AR expression was demonstrated in the cortex and hippocampus from early to late adulthood. Specifically, a decrease in A1R and enhancement of A2AR expression were demonstrated by immunohistochemistry, the latter being almost exclusively localized in hippocampal pyramidal and cortical superficial cell layers. We did not observe any glial upregulation of A2AR, which was common for both advanced age and chronic neurodegeneration. Taken together, the results imply that the adaptative changes in adenosine signaling occurring in neuronal elements early in life may be responsible for the later prominent glial enhancement in A2AR-mediated adenosine signaling, and neuroinflammation and neurodegeneration, which are the hallmarks of both advanced age and age-associated neurodegenerative diseases.
T2  - Neurochemical Research
T1  - Altered Topographic Distribution and Enhanced Neuronal Expression of Adenosine-Metabolizing Enzymes in Rat Hippocampus and Cortex from Early to late Adulthood
DO  - 10.1007/s11064-022-03557-5
ER  - 

@article{
author = "Dragić, Milorad and Stekić, Anđela and Zeljković, Milica and Zarić Kontić, Marina and Mihajlović, Katarina and Adžić, Marija and Grković, Ivana and Nedeljković, Nadežda",
year = "2022",
abstract = "The present study demonstrates altered topographic distribution and enhanced neuronal expression of major adenosine-metabolizing enzymes, i.e. ecto-5ʹ-nucleotidase (eN) and tissue non-specific alkaline phosphatase (TNAP), as well as adenosine receptor subtype A2A in the hippocampus and cortex of male rats from early to late adulthood (3, 6, 12 and 15 months old males). The significant effect of age was demonstrated for the increase in the activity and the protein expression of eN and TNAP. At 15-m, enzyme histochemistry demonstrated enhanced expression of eN in synapse-rich hippocampal and cortical layers, whereas the upsurge of TNAP was observed in the hippocampal and cortical neuropil, rather than in cells and layers where two enzymes mostly reside in 3-m old brain. Furthermore, a dichotomy in A1R and A2AR expression was demonstrated in the cortex and hippocampus from early to late adulthood. Specifically, a decrease in A1R and enhancement of A2AR expression were demonstrated by immunohistochemistry, the latter being almost exclusively localized in hippocampal pyramidal and cortical superficial cell layers. We did not observe any glial upregulation of A2AR, which was common for both advanced age and chronic neurodegeneration. Taken together, the results imply that the adaptative changes in adenosine signaling occurring in neuronal elements early in life may be responsible for the later prominent glial enhancement in A2AR-mediated adenosine signaling, and neuroinflammation and neurodegeneration, which are the hallmarks of both advanced age and age-associated neurodegenerative diseases.",
journal = "Neurochemical Research",
title = "Altered Topographic Distribution and Enhanced Neuronal Expression of Adenosine-Metabolizing Enzymes in Rat Hippocampus and Cortex from Early to late Adulthood",
doi = "10.1007/s11064-022-03557-5"
}

Dragić, M., Stekić, A., Zeljković, M., Zarić Kontić, M., Mihajlović, K., Adžić, M., Grković, I.,& Nedeljković, N.. (2022). Altered Topographic Distribution and Enhanced Neuronal Expression of Adenosine-Metabolizing Enzymes in Rat Hippocampus and Cortex from Early to late Adulthood. in Neurochemical Research.
https://doi.org/10.1007/s11064-022-03557-5

Dragić M, Stekić A, Zeljković M, Zarić Kontić M, Mihajlović K, Adžić M, Grković I, Nedeljković N. Altered Topographic Distribution and Enhanced Neuronal Expression of Adenosine-Metabolizing Enzymes in Rat Hippocampus and Cortex from Early to late Adulthood. in Neurochemical Research. 2022;.
doi:10.1007/s11064-022-03557-5 .

Dragić, Milorad, Stekić, Anđela, Zeljković, Milica, Zarić Kontić, Marina, Mihajlović, Katarina, Adžić, Marija, Grković, Ivana, Nedeljković, Nadežda, "Altered Topographic Distribution and Enhanced Neuronal Expression of Adenosine-Metabolizing Enzymes in Rat Hippocampus and Cortex from Early to late Adulthood" in Neurochemical Research (2022),
https://doi.org/10.1007/s11064-022-03557-5 . .

TY  - JOUR
AU  - Dragić, Milorad
AU  - Mitrović, Nataša Lj.
AU  - Adžić, Marija
AU  - Nedeljković, Nadežda
AU  - Grković, Ivana
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9970
AB  - The present study examined the involvement of purinergic signaling components in the rat model of hippocampal degeneration induced by trimethyltin (TMT) intoxication (8 mg/kg, single intraperitoneal injection), which results in behavioral and neurological dysfunction similar to neurodegenerative disorders. We investigated spatial and temporal patterns of ecto-nucleoside triphosphate diphosphohydrolase 1 (NTPDase1/CD39) and ecto-5′ nucleotidase (eN/CD73) activity, their cell-specific localization, and analyzed gene expression pattern and/or cellular localization of purinoreceptors and proinflammatory mediators associated with reactive glial cells. Our study demonstrated that all Iba1+ cells at the injured area, irrespective of their morphology, upregulated NTPDase1/CD39, while induction of eN/CD73 has been observed at amoeboid Iba1+ cells localized within the hippocampal neuronal layers with pronounced cell death. Marked induction of P2Y12R, P2Y6R, and P2X4-messenger RNA at the early stage of TMT-induced neurodegeneration might reflect the functional properties, migration, and chemotaxis of microglia, while induction of P2X7R at amoeboid cells probably modulates their phagocytic role. Reactive astrocytes expressed adenosine A1, A2A, and P2Y1 receptors, revealed induction of complement component C3, inducible nitric oxide synthase, nuclear factor-kB, and proinflammatory cytokines at the late stage of TMT-induced neurodegeneration. An increased set of purinergic system components on activated microglia (NTPDase1/CD39, eN/CD73, and P2X7) and astrocytes (A1R, A2AR, and P2Y1), and loss of homeostatic glial and neuronal purinergic pathways (P2Y12 and A1R) may shift purinergic signaling balance toward excitotoxicity and inflammation, thus favoring progression of pathological events. These findings may contribute to a better understanding of the involvement of purinergic signaling components in the progression of neurodegenerative disorders that could be target molecules for the development of novel therapies.
T2  - ASN Neuro
T1  - Microglial- and Astrocyte-Specific Expression of Purinergic Signaling Components and Inflammatory Mediators in the Rat Hippocampus During Trimethyltin-Induced Neurodegeneration
VL  - 13
SP  - 17590914211044882
DO  - 10.1177/17590914211044882
ER  - 

@article{
author = "Dragić, Milorad and Mitrović, Nataša Lj. and Adžić, Marija and Nedeljković, Nadežda and Grković, Ivana",
year = "2021",
abstract = "The present study examined the involvement of purinergic signaling components in the rat model of hippocampal degeneration induced by trimethyltin (TMT) intoxication (8 mg/kg, single intraperitoneal injection), which results in behavioral and neurological dysfunction similar to neurodegenerative disorders. We investigated spatial and temporal patterns of ecto-nucleoside triphosphate diphosphohydrolase 1 (NTPDase1/CD39) and ecto-5′ nucleotidase (eN/CD73) activity, their cell-specific localization, and analyzed gene expression pattern and/or cellular localization of purinoreceptors and proinflammatory mediators associated with reactive glial cells. Our study demonstrated that all Iba1+ cells at the injured area, irrespective of their morphology, upregulated NTPDase1/CD39, while induction of eN/CD73 has been observed at amoeboid Iba1+ cells localized within the hippocampal neuronal layers with pronounced cell death. Marked induction of P2Y12R, P2Y6R, and P2X4-messenger RNA at the early stage of TMT-induced neurodegeneration might reflect the functional properties, migration, and chemotaxis of microglia, while induction of P2X7R at amoeboid cells probably modulates their phagocytic role. Reactive astrocytes expressed adenosine A1, A2A, and P2Y1 receptors, revealed induction of complement component C3, inducible nitric oxide synthase, nuclear factor-kB, and proinflammatory cytokines at the late stage of TMT-induced neurodegeneration. An increased set of purinergic system components on activated microglia (NTPDase1/CD39, eN/CD73, and P2X7) and astrocytes (A1R, A2AR, and P2Y1), and loss of homeostatic glial and neuronal purinergic pathways (P2Y12 and A1R) may shift purinergic signaling balance toward excitotoxicity and inflammation, thus favoring progression of pathological events. These findings may contribute to a better understanding of the involvement of purinergic signaling components in the progression of neurodegenerative disorders that could be target molecules for the development of novel therapies.",
journal = "ASN Neuro",
title = "Microglial- and Astrocyte-Specific Expression of Purinergic Signaling Components and Inflammatory Mediators in the Rat Hippocampus During Trimethyltin-Induced Neurodegeneration",
volume = "13",
pages = "17590914211044882",
doi = "10.1177/17590914211044882"
}

Dragić, M., Mitrović, N. Lj., Adžić, M., Nedeljković, N.,& Grković, I.. (2021). Microglial- and Astrocyte-Specific Expression of Purinergic Signaling Components and Inflammatory Mediators in the Rat Hippocampus During Trimethyltin-Induced Neurodegeneration. in ASN Neuro, 13, 17590914211044882.
https://doi.org/10.1177/17590914211044882

Dragić M, Mitrović NL, Adžić M, Nedeljković N, Grković I. Microglial- and Astrocyte-Specific Expression of Purinergic Signaling Components and Inflammatory Mediators in the Rat Hippocampus During Trimethyltin-Induced Neurodegeneration. in ASN Neuro. 2021;13:17590914211044882.
doi:10.1177/17590914211044882 .

Dragić, Milorad, Mitrović, Nataša Lj., Adžić, Marija, Nedeljković, Nadežda, Grković, Ivana, "Microglial- and Astrocyte-Specific Expression of Purinergic Signaling Components and Inflammatory Mediators in the Rat Hippocampus During Trimethyltin-Induced Neurodegeneration" in ASN Neuro, 13 (2021):17590914211044882,
https://doi.org/10.1177/17590914211044882 . .

TY  - JOUR
AU  - Dragić, Milorad
AU  - Zeljković, Milica
AU  - Stevanović, Ivana
AU  - Adžić, Marija
AU  - Stekić, Anđela
AU  - Mihajlović, Katarina
AU  - Grković, Ivana
AU  - Ilić, Nela
AU  - Ilić, Tihomir V.
AU  - Nedeljković, Nadežda
AU  - Ninković, Milica
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10082
AB  - Multiple sclerosis (MS) is a chronic neurodegenerative disease caused by autoimmune-mediated inflammation in the central nervous system. Purinergic signaling is critically involved in MS-associated neuroinflammation and its most widely applied animal model—experimental autoimmune encephalomyelitis (EAE). A promising but poorly understood approach in the treatment of MS is repetitive transcranial magnetic stimulation. In the present study, we aimed to investigate the effect of continuous theta-burst stimulation (CTBS), applied over frontal cranial bone, on the adenosine-mediated signaling system in EAE, particularly on CD73/A2AR/A1R in the context of neuroinflammatory activation of glial cells. EAE was induced in two-month-old female DA rats and in the disease peak treated with CTBS protocol for ten consecutive days. Lumbosacral spinal cord was analyzed immunohistochemically for adenosine-mediated signaling components and pro- and anti-inflammatory factors. We found downregulated IL-1β and NF- κB-ir and upregulated IL-10 pointing towards a reduction in the neuroinflammatory process in EAE animals after CTBS treatment. Furthermore, CTBS attenuated EAE-induced glial eN/CD73 expression and activity, while inducing a shift in A2AR expression from glia to neurons, contrary to EAE, where tight coupling of eN/CD73 and A2AR on glial cells is observed. Finally, increased glial A1R expression following CTBS supports anti-inflammatory adenosine actions and potentially contributes to the overall neuroprotective effect observed in EAE animals after CTBS treatment.
T2  - Brain Sciences
T2  - Brain Sciences
T1  - Downregulation of CD73/A2AR-Mediated Adenosine Signaling as a Potential Mechanism of Neuroprotective Effects of Theta-Burst Transcranial Magnetic Stimulation in Acute Experimental Autoimmune Encephalomyelitis
VL  - 11
IS  - 6
SP  - 736
DO  - 10.3390/brainsci11060736
ER  - 

@article{
author = "Dragić, Milorad and Zeljković, Milica and Stevanović, Ivana and Adžić, Marija and Stekić, Anđela and Mihajlović, Katarina and Grković, Ivana and Ilić, Nela and Ilić, Tihomir V. and Nedeljković, Nadežda and Ninković, Milica",
year = "2021",
abstract = "Multiple sclerosis (MS) is a chronic neurodegenerative disease caused by autoimmune-mediated inflammation in the central nervous system. Purinergic signaling is critically involved in MS-associated neuroinflammation and its most widely applied animal model—experimental autoimmune encephalomyelitis (EAE). A promising but poorly understood approach in the treatment of MS is repetitive transcranial magnetic stimulation. In the present study, we aimed to investigate the effect of continuous theta-burst stimulation (CTBS), applied over frontal cranial bone, on the adenosine-mediated signaling system in EAE, particularly on CD73/A2AR/A1R in the context of neuroinflammatory activation of glial cells. EAE was induced in two-month-old female DA rats and in the disease peak treated with CTBS protocol for ten consecutive days. Lumbosacral spinal cord was analyzed immunohistochemically for adenosine-mediated signaling components and pro- and anti-inflammatory factors. We found downregulated IL-1β and NF- κB-ir and upregulated IL-10 pointing towards a reduction in the neuroinflammatory process in EAE animals after CTBS treatment. Furthermore, CTBS attenuated EAE-induced glial eN/CD73 expression and activity, while inducing a shift in A2AR expression from glia to neurons, contrary to EAE, where tight coupling of eN/CD73 and A2AR on glial cells is observed. Finally, increased glial A1R expression following CTBS supports anti-inflammatory adenosine actions and potentially contributes to the overall neuroprotective effect observed in EAE animals after CTBS treatment.",
journal = "Brain Sciences, Brain Sciences",
title = "Downregulation of CD73/A2AR-Mediated Adenosine Signaling as a Potential Mechanism of Neuroprotective Effects of Theta-Burst Transcranial Magnetic Stimulation in Acute Experimental Autoimmune Encephalomyelitis",
volume = "11",
number = "6",
pages = "736",
doi = "10.3390/brainsci11060736"
}

Dragić, M., Zeljković, M., Stevanović, I., Adžić, M., Stekić, A., Mihajlović, K., Grković, I., Ilić, N., Ilić, T. V., Nedeljković, N.,& Ninković, M.. (2021). Downregulation of CD73/A2AR-Mediated Adenosine Signaling as a Potential Mechanism of Neuroprotective Effects of Theta-Burst Transcranial Magnetic Stimulation in Acute Experimental Autoimmune Encephalomyelitis. in Brain Sciences, 11(6), 736.
https://doi.org/10.3390/brainsci11060736

Dragić M, Zeljković M, Stevanović I, Adžić M, Stekić A, Mihajlović K, Grković I, Ilić N, Ilić TV, Nedeljković N, Ninković M. Downregulation of CD73/A2AR-Mediated Adenosine Signaling as a Potential Mechanism of Neuroprotective Effects of Theta-Burst Transcranial Magnetic Stimulation in Acute Experimental Autoimmune Encephalomyelitis. in Brain Sciences. 2021;11(6):736.
doi:10.3390/brainsci11060736 .

Dragić, Milorad, Zeljković, Milica, Stevanović, Ivana, Adžić, Marija, Stekić, Anđela, Mihajlović, Katarina, Grković, Ivana, Ilić, Nela, Ilić, Tihomir V., Nedeljković, Nadežda, Ninković, Milica, "Downregulation of CD73/A2AR-Mediated Adenosine Signaling as a Potential Mechanism of Neuroprotective Effects of Theta-Burst Transcranial Magnetic Stimulation in Acute Experimental Autoimmune Encephalomyelitis" in Brain Sciences, 11, no. 6 (2021):736,
https://doi.org/10.3390/brainsci11060736 . .

TY  - JOUR
AU  - Dragić, Milorad
AU  - Milićević, Katarina
AU  - Adžić, Marija
AU  - Stevanović, Ivana
AU  - Ninković, Milica
AU  - Grković, Ivana
AU  - Anđus, Pavle
AU  - Nedeljković, Nadežda
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9174
AB  - Astrocytes are the first responders to noxious stimuli by undergoing cellular and functional transition referred as reactive gliosis. Every acute or chronic disorder is accompanied by reactive gliosis, which could be categorized as detrimental (A1) of beneficial (A2) for nervous tissue. Another signature of pathological astrocyte activation is disturbed Ca2+ homeostasis, a common denominator of neurodegenerative diseases. Deregulation of Ca+ signaling further contributes to production of pro-inflammatory cytokines and reactive oxygen species. Trimethyltin (TMT) intoxication is a widely used model of hippocampal degeneration, sharing behavioral and molecular hallmarks of Alzheimer’s disease (AD), thus representing a useful model of AD-like pathology. However, the role of astrocyte in the etiopathology of TMT-induced degeneration as well as in AD is not fully understood. In an effort to elucidate the role of astrocytes in such pathological processes, we examined in vitro effects of TMT on primary cortical astrocytes. The application of a range of TMT concentrations (5, 10, 50, and 100 μM) revealed changes in [Ca2+]i in a dose-dependent manner. Specifically, TMT-induced Ca2+ transients were due to L-type voltage-gated calcium channels (VGCC). Additionally, TMT induced mitochondrial depolarization independent of extracellular Ca2+ and disturbed antioxidative defense of astrocyte in several time points (4, 6, and 24 h) after 10 μM TMT intoxication, inducing oxidative and nitrosative stress. Chronic exposure (24 h) to 10 μM TMT induced strong upregulation of main pro-inflammatory factors, components of signaling pathways in astrocyte activation, A1 markers, and VGCC. Taken together, our results provide an insight into cellular and molecular events of astrocyte activation in chronic neuroinflammation. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.
T2  - Molecular Neurobiology
T1  - Trimethyltin Increases Intracellular Ca2+ Via L-Type Voltage-Gated Calcium Channels and Promotes Inflammatory Phenotype in Rat Astrocytes In Vitro
VL  - 58
IS  - 4
SP  - 1792
EP  - 1805
DO  - 10.1007/s12035-020-02273-x
ER  - 

@article{
author = "Dragić, Milorad and Milićević, Katarina and Adžić, Marija and Stevanović, Ivana and Ninković, Milica and Grković, Ivana and Anđus, Pavle and Nedeljković, Nadežda",
year = "2021",
abstract = "Astrocytes are the first responders to noxious stimuli by undergoing cellular and functional transition referred as reactive gliosis. Every acute or chronic disorder is accompanied by reactive gliosis, which could be categorized as detrimental (A1) of beneficial (A2) for nervous tissue. Another signature of pathological astrocyte activation is disturbed Ca2+ homeostasis, a common denominator of neurodegenerative diseases. Deregulation of Ca+ signaling further contributes to production of pro-inflammatory cytokines and reactive oxygen species. Trimethyltin (TMT) intoxication is a widely used model of hippocampal degeneration, sharing behavioral and molecular hallmarks of Alzheimer’s disease (AD), thus representing a useful model of AD-like pathology. However, the role of astrocyte in the etiopathology of TMT-induced degeneration as well as in AD is not fully understood. In an effort to elucidate the role of astrocytes in such pathological processes, we examined in vitro effects of TMT on primary cortical astrocytes. The application of a range of TMT concentrations (5, 10, 50, and 100 μM) revealed changes in [Ca2+]i in a dose-dependent manner. Specifically, TMT-induced Ca2+ transients were due to L-type voltage-gated calcium channels (VGCC). Additionally, TMT induced mitochondrial depolarization independent of extracellular Ca2+ and disturbed antioxidative defense of astrocyte in several time points (4, 6, and 24 h) after 10 μM TMT intoxication, inducing oxidative and nitrosative stress. Chronic exposure (24 h) to 10 μM TMT induced strong upregulation of main pro-inflammatory factors, components of signaling pathways in astrocyte activation, A1 markers, and VGCC. Taken together, our results provide an insight into cellular and molecular events of astrocyte activation in chronic neuroinflammation. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.",
journal = "Molecular Neurobiology",
title = "Trimethyltin Increases Intracellular Ca2+ Via L-Type Voltage-Gated Calcium Channels and Promotes Inflammatory Phenotype in Rat Astrocytes In Vitro",
volume = "58",
number = "4",
pages = "1792-1805",
doi = "10.1007/s12035-020-02273-x"
}

Dragić, M., Milićević, K., Adžić, M., Stevanović, I., Ninković, M., Grković, I., Anđus, P.,& Nedeljković, N.. (2021). Trimethyltin Increases Intracellular Ca2+ Via L-Type Voltage-Gated Calcium Channels and Promotes Inflammatory Phenotype in Rat Astrocytes In Vitro. in Molecular Neurobiology, 58(4), 1792-1805.
https://doi.org/10.1007/s12035-020-02273-x

Dragić M, Milićević K, Adžić M, Stevanović I, Ninković M, Grković I, Anđus P, Nedeljković N. Trimethyltin Increases Intracellular Ca2+ Via L-Type Voltage-Gated Calcium Channels and Promotes Inflammatory Phenotype in Rat Astrocytes In Vitro. in Molecular Neurobiology. 2021;58(4):1792-1805.
doi:10.1007/s12035-020-02273-x .

Dragić, Milorad, Milićević, Katarina, Adžić, Marija, Stevanović, Ivana, Ninković, Milica, Grković, Ivana, Anđus, Pavle, Nedeljković, Nadežda, "Trimethyltin Increases Intracellular Ca2+ Via L-Type Voltage-Gated Calcium Channels and Promotes Inflammatory Phenotype in Rat Astrocytes In Vitro" in Molecular Neurobiology, 58, no. 4 (2021):1792-1805,
https://doi.org/10.1007/s12035-020-02273-x . .

TY  - JOUR
AU  - Grković, Ivana
AU  - Mitrović, Nataša Lj.
AU  - Dragić, Milorad
AU  - Adžić, Marija
AU  - Drakulić, Dunja R.
AU  - Nedeljković, Nadežda
PY  - 2019
UR  - http://link.springer.com/10.1007/s12035-018-1217-3
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8102
AB  - Purinergic signaling is the main synaptic and non-synaptic signaling system in brain. ATP acts as a fast excitatory transmitter, while adenosine sets a global inhibitory tone within hippocampal neuronal networks. ATP and adenosine are interconnected by ectonucleotidase enzymes, which convert ATP to adenosine. Existing data point to the converging roles of ovarian steroids and purinergic signaling in synapse formation and refinement and synapse activity in the hippocampus. Therefore, in the present study, we have used enzyme histochemistry and expression analysis to obtain data on spatial distribution and expression of ecto-enzymes NTPDase1, NTPDase2, and ecto-5-nucleotidase (eN) after removal of ovaries (OVX) and estradiol replacement (E2) in female rat hippocampus. The results show that target ectonucleotidases are predominantly localized in synapse-rich hippocampal layers. The most represented NTPDase in the hippocampal tissue is NTPDase2, being at the same time the mostly affected ectonucleotidase by OVX and E2. Specifically, OVX decreases the expression of NTPDase2 and eN, whereas E2 restores their expression to control level. Impact of OVX and E2 on ectonucleotidase expression was also examined in purified synaptosome (SYN) and gliosome (GLIO) fractions. Data reveal that SYN expresses NTPDase1 and NTPDase2, both of which are reduced following OVX and restored with E2. GLIO exhibits NTPDase2-mediated ATP hydrolysis, which falls in OVX, and recovers by E2. These changes in the activity occur without parallel changes in NTPDase2-protein abundance. The same holds for eN. The lack of correlation between NTPDase2 and eN activities and their respective protein abundances suggest a non-genomic mode of E2 action, which is studied further in primary astrocyte culture. Since ovarian steroids shape hippocampal synaptic networks and regulate ectonucleotidase activities, it is possible that cognitive deficits seen after ovary removal may arise from the loss of E2 modulatory actions on ectonucleotidase expression in the hippocampus.
T2  - Molecular Neurobiology
T2  - Molecular Neurobiology
T1  - Spatial Distribution and Expression of Ectonucleotidases in Rat Hippocampus After Removal of Ovaries and Estradiol Replacement
VL  - 56
IS  - 3
SP  - 1933
EP  - 1945
DO  - 10.1007/s12035-018-1217-3
ER  - 

@article{
author = "Grković, Ivana and Mitrović, Nataša Lj. and Dragić, Milorad and Adžić, Marija and Drakulić, Dunja R. and Nedeljković, Nadežda",
year = "2019",
abstract = "Purinergic signaling is the main synaptic and non-synaptic signaling system in brain. ATP acts as a fast excitatory transmitter, while adenosine sets a global inhibitory tone within hippocampal neuronal networks. ATP and adenosine are interconnected by ectonucleotidase enzymes, which convert ATP to adenosine. Existing data point to the converging roles of ovarian steroids and purinergic signaling in synapse formation and refinement and synapse activity in the hippocampus. Therefore, in the present study, we have used enzyme histochemistry and expression analysis to obtain data on spatial distribution and expression of ecto-enzymes NTPDase1, NTPDase2, and ecto-5-nucleotidase (eN) after removal of ovaries (OVX) and estradiol replacement (E2) in female rat hippocampus. The results show that target ectonucleotidases are predominantly localized in synapse-rich hippocampal layers. The most represented NTPDase in the hippocampal tissue is NTPDase2, being at the same time the mostly affected ectonucleotidase by OVX and E2. Specifically, OVX decreases the expression of NTPDase2 and eN, whereas E2 restores their expression to control level. Impact of OVX and E2 on ectonucleotidase expression was also examined in purified synaptosome (SYN) and gliosome (GLIO) fractions. Data reveal that SYN expresses NTPDase1 and NTPDase2, both of which are reduced following OVX and restored with E2. GLIO exhibits NTPDase2-mediated ATP hydrolysis, which falls in OVX, and recovers by E2. These changes in the activity occur without parallel changes in NTPDase2-protein abundance. The same holds for eN. The lack of correlation between NTPDase2 and eN activities and their respective protein abundances suggest a non-genomic mode of E2 action, which is studied further in primary astrocyte culture. Since ovarian steroids shape hippocampal synaptic networks and regulate ectonucleotidase activities, it is possible that cognitive deficits seen after ovary removal may arise from the loss of E2 modulatory actions on ectonucleotidase expression in the hippocampus.",
journal = "Molecular Neurobiology, Molecular Neurobiology",
title = "Spatial Distribution and Expression of Ectonucleotidases in Rat Hippocampus After Removal of Ovaries and Estradiol Replacement",
volume = "56",
number = "3",
pages = "1933-1945",
doi = "10.1007/s12035-018-1217-3"
}

Grković, I., Mitrović, N. Lj., Dragić, M., Adžić, M., Drakulić, D. R.,& Nedeljković, N.. (2019). Spatial Distribution and Expression of Ectonucleotidases in Rat Hippocampus After Removal of Ovaries and Estradiol Replacement. in Molecular Neurobiology, 56(3), 1933-1945.
https://doi.org/10.1007/s12035-018-1217-3

Grković I, Mitrović NL, Dragić M, Adžić M, Drakulić DR, Nedeljković N. Spatial Distribution and Expression of Ectonucleotidases in Rat Hippocampus After Removal of Ovaries and Estradiol Replacement. in Molecular Neurobiology. 2019;56(3):1933-1945.
doi:10.1007/s12035-018-1217-3 .

Grković, Ivana, Mitrović, Nataša Lj., Dragić, Milorad, Adžić, Marija, Drakulić, Dunja R., Nedeljković, Nadežda, "Spatial Distribution and Expression of Ectonucleotidases in Rat Hippocampus After Removal of Ovaries and Estradiol Replacement" in Molecular Neurobiology, 56, no. 3 (2019):1933-1945,
https://doi.org/10.1007/s12035-018-1217-3 . .

TY  - JOUR
AU  - Dragić, Milorad
AU  - Zarić, Marina
AU  - Mitrović, Nataša Lj.
AU  - Nedeljković, Nadežda
AU  - Grković, Ivana
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8489
AB  - Enzyme histochemistry is a valuable histological method which provides a connection between morphology, activity, and spatial localization of investigated enzymes. Even though the method relies purely on arbitrary evaluations performed by the human eye, it is still wildly accepted and used in histo(patho)logy. Texture analysis emerged as an excellent tool for image quantification of subtle differences reflected in both spatial discrepancies and gray level values of pixels. The current study of texture analysis utilizes the gray-level co-occurrence matrix as a method for quantification of differences between ecto-5′-nucleotidase activities in healthy hippocampal tissue and tissue with marked neurodegeneration. We used the angular second moment, contrast (CON), correlation, inverse difference moment (INV), and entropy for texture analysis and receiver operating characteristic analysis with immunoblot and qualitative assessment of enzyme histochemistry as a validation. Our results strongly argue that co-occurrence matrix analysis could be used for the determination of fine differences in the enzyme activities with the possibility to ascribe those differences to regions or specific cell types. In addition, it emerged that INV and CON are especially useful parameters for this type of enzyme histochemistry analysis. We concluded that texture analysis is a reliable method for quantification of this descriptive technique, thus removing biases and adding it a quantitative dimension.
T2  - Microscopy and Microanalysis
T1  - Application of Gray Level Co-Occurrence Matrix Analysis as a New Method for Enzyme Histochemistry Quantification
VL  - 25
IS  - 3
SP  - 690
EP  - 698
DO  - 10.1017/S1431927618016306
ER  - 

@article{
author = "Dragić, Milorad and Zarić, Marina and Mitrović, Nataša Lj. and Nedeljković, Nadežda and Grković, Ivana",
year = "2019",
abstract = "Enzyme histochemistry is a valuable histological method which provides a connection between morphology, activity, and spatial localization of investigated enzymes. Even though the method relies purely on arbitrary evaluations performed by the human eye, it is still wildly accepted and used in histo(patho)logy. Texture analysis emerged as an excellent tool for image quantification of subtle differences reflected in both spatial discrepancies and gray level values of pixels. The current study of texture analysis utilizes the gray-level co-occurrence matrix as a method for quantification of differences between ecto-5′-nucleotidase activities in healthy hippocampal tissue and tissue with marked neurodegeneration. We used the angular second moment, contrast (CON), correlation, inverse difference moment (INV), and entropy for texture analysis and receiver operating characteristic analysis with immunoblot and qualitative assessment of enzyme histochemistry as a validation. Our results strongly argue that co-occurrence matrix analysis could be used for the determination of fine differences in the enzyme activities with the possibility to ascribe those differences to regions or specific cell types. In addition, it emerged that INV and CON are especially useful parameters for this type of enzyme histochemistry analysis. We concluded that texture analysis is a reliable method for quantification of this descriptive technique, thus removing biases and adding it a quantitative dimension.",
journal = "Microscopy and Microanalysis",
title = "Application of Gray Level Co-Occurrence Matrix Analysis as a New Method for Enzyme Histochemistry Quantification",
volume = "25",
number = "3",
pages = "690-698",
doi = "10.1017/S1431927618016306"
}

Dragić, M., Zarić, M., Mitrović, N. Lj., Nedeljković, N.,& Grković, I.. (2019). Application of Gray Level Co-Occurrence Matrix Analysis as a New Method for Enzyme Histochemistry Quantification. in Microscopy and Microanalysis, 25(3), 690-698.
https://doi.org/10.1017/S1431927618016306

Dragić M, Zarić M, Mitrović NL, Nedeljković N, Grković I. Application of Gray Level Co-Occurrence Matrix Analysis as a New Method for Enzyme Histochemistry Quantification. in Microscopy and Microanalysis. 2019;25(3):690-698.
doi:10.1017/S1431927618016306 .

Dragić, Milorad, Zarić, Marina, Mitrović, Nataša Lj., Nedeljković, Nadežda, Grković, Ivana, "Application of Gray Level Co-Occurrence Matrix Analysis as a New Method for Enzyme Histochemistry Quantification" in Microscopy and Microanalysis, 25, no. 3 (2019):690-698,
https://doi.org/10.1017/S1431927618016306 . .

TY  - JOUR
AU  - Mitrović, Nataša Lj.
AU  - Dragić, Milorad
AU  - Zarić, Marina
AU  - Drakulić, Dunja R.
AU  - Nedeljković, Nadežda
AU  - Grković, Ivana
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8497
AB  - Extracellular adenine nucleotides and nucleosides, such as adenosine-5'-triphosphate (ATP) and adenosine, are among least investigated signaling factors that participate in 17β-estradiol (E2)-mediated synaptic rearrangements in rodent hippocampus. Their levels in the extrasynaptic space are tightly controlled by ecto-nucleoside triphosphate diphosphohydrolases1-3 (NTPDase1-3)/ecto-5'-nucleotidase (eN) enzyme chain. Therefore, the aim of the present study was to get closer insight in the E2-induced decrease in NTPDase and eN activity in the hippocampal synaptic compartment of male rats and to identify estradiol receptors (ERs i.e. ERα, ERβ or GPER1) responsible for the observed effects of E2. In this study we show indiscriminate participation of estradiol receptor α (ERα), -β (ERβ) and G- protein coupled estrogen receptor 1 (GPER1) in the mediation of E2 actions in hippocampal synaptosomes of male rats. Synaptic NTPDase1-3 activities are modulated only through activation of ERβ, while activation of ERα, -β and/or non-classical GPER1 decreases synaptic eN activity. Since both ATP and adenosine function as neuromodulators in the hippocampal networks, influencing its function, profound knowledge of mechanisms by which ectonucleotidases are regulated/modulated is of great importance. © 2019 Elsevier B.V.
T2  - Neuroscience Letters
T1  - Estrogen receptors modulate ectonucleotidases activity in hippocampal synaptosomes of male rats
VL  - 712
SP  - 134474
DO  - 10.1016/j.neulet.2019.134474
ER  - 

@article{
author = "Mitrović, Nataša Lj. and Dragić, Milorad and Zarić, Marina and Drakulić, Dunja R. and Nedeljković, Nadežda and Grković, Ivana",
year = "2019",
abstract = "Extracellular adenine nucleotides and nucleosides, such as adenosine-5'-triphosphate (ATP) and adenosine, are among least investigated signaling factors that participate in 17β-estradiol (E2)-mediated synaptic rearrangements in rodent hippocampus. Their levels in the extrasynaptic space are tightly controlled by ecto-nucleoside triphosphate diphosphohydrolases1-3 (NTPDase1-3)/ecto-5'-nucleotidase (eN) enzyme chain. Therefore, the aim of the present study was to get closer insight in the E2-induced decrease in NTPDase and eN activity in the hippocampal synaptic compartment of male rats and to identify estradiol receptors (ERs i.e. ERα, ERβ or GPER1) responsible for the observed effects of E2. In this study we show indiscriminate participation of estradiol receptor α (ERα), -β (ERβ) and G- protein coupled estrogen receptor 1 (GPER1) in the mediation of E2 actions in hippocampal synaptosomes of male rats. Synaptic NTPDase1-3 activities are modulated only through activation of ERβ, while activation of ERα, -β and/or non-classical GPER1 decreases synaptic eN activity. Since both ATP and adenosine function as neuromodulators in the hippocampal networks, influencing its function, profound knowledge of mechanisms by which ectonucleotidases are regulated/modulated is of great importance. © 2019 Elsevier B.V.",
journal = "Neuroscience Letters",
title = "Estrogen receptors modulate ectonucleotidases activity in hippocampal synaptosomes of male rats",
volume = "712",
pages = "134474",
doi = "10.1016/j.neulet.2019.134474"
}

Mitrović, N. Lj., Dragić, M., Zarić, M., Drakulić, D. R., Nedeljković, N.,& Grković, I.. (2019). Estrogen receptors modulate ectonucleotidases activity in hippocampal synaptosomes of male rats. in Neuroscience Letters, 712, 134474.
https://doi.org/10.1016/j.neulet.2019.134474

Mitrović NL, Dragić M, Zarić M, Drakulić DR, Nedeljković N, Grković I. Estrogen receptors modulate ectonucleotidases activity in hippocampal synaptosomes of male rats. in Neuroscience Letters. 2019;712:134474.
doi:10.1016/j.neulet.2019.134474 .

Mitrović, Nataša Lj., Dragić, Milorad, Zarić, Marina, Drakulić, Dunja R., Nedeljković, Nadežda, Grković, Ivana, "Estrogen receptors modulate ectonucleotidases activity in hippocampal synaptosomes of male rats" in Neuroscience Letters, 712 (2019):134474,
https://doi.org/10.1016/j.neulet.2019.134474 . .

TY  - JOUR
AU  - Dragić, Milorad
AU  - Zarić, Marina
AU  - Mitrović, Nataša Lj.
AU  - Nedeljković, Nadežda
AU  - Grković, Ivana
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8647
AB  - Astrocytes comprise a heterogenic group of glial cells, which perform homeostatic functions in the central nervous system. These cells react to all kind of insults by changing the morphology and function that result in a transition from the quiescent to a reactive phenotype. Trimethyltin (TMT) intoxication, which reproduces pathological events in the hippocampus similar to those associated with seizures and cognitive decline, has been proven as a useful model for studying responses of the glial cells to neurodegeneration. In the present study, we have explored morphological varieties of astrocytes in the hippocampal subregions of ovariectomized female rats exposed to TMT. We have demonstrated an early loss of neurons in CA1 and DG subfields. Distinct morphotypes of protoplasmic astrocytes observed in CA1/CA3 and the hilus of control animals developed different responses to TMT intoxication, as assessed by GFAP-immunohistochemistry. In CA1 subregion, GFAP+ astrocytes preserved their domain organization and responded with typical hypertrophy, while the hilar GFAP+ astrocytes developed atrophy-like phenotype and increased expression of vimentin and nestin 7 days after the exposure. Both reactive and atrophied-like astrocytes expressed Kir4.1 in CA1/CA3 and the hilus of DG, respectively, indicating that these cells did not change their potential for normal activity at this time point of pathology. Together, the results demonstrate the persistence of two protoplasmic morphotypes of astrocytes, with distinct appearance, function, and fate after TMT-induced neurodegeneration, suggesting their pleiotropic roles in the hippocampal response to neurodegeneration. © 2019 IBRO
T2  - Neuroscience
T1  - Two Distinct Hippocampal Astrocyte Morphotypes Reveal Subfield-Different Fate during Neurodegeneration Induced by Trimethyltin Intoxication
VL  - 423
SP  - 38
EP  - 54
DO  - 10.1016/j.neuroscience.2019.10.022
ER  - 

@article{
author = "Dragić, Milorad and Zarić, Marina and Mitrović, Nataša Lj. and Nedeljković, Nadežda and Grković, Ivana",
year = "2019",
abstract = "Astrocytes comprise a heterogenic group of glial cells, which perform homeostatic functions in the central nervous system. These cells react to all kind of insults by changing the morphology and function that result in a transition from the quiescent to a reactive phenotype. Trimethyltin (TMT) intoxication, which reproduces pathological events in the hippocampus similar to those associated with seizures and cognitive decline, has been proven as a useful model for studying responses of the glial cells to neurodegeneration. In the present study, we have explored morphological varieties of astrocytes in the hippocampal subregions of ovariectomized female rats exposed to TMT. We have demonstrated an early loss of neurons in CA1 and DG subfields. Distinct morphotypes of protoplasmic astrocytes observed in CA1/CA3 and the hilus of control animals developed different responses to TMT intoxication, as assessed by GFAP-immunohistochemistry. In CA1 subregion, GFAP+ astrocytes preserved their domain organization and responded with typical hypertrophy, while the hilar GFAP+ astrocytes developed atrophy-like phenotype and increased expression of vimentin and nestin 7 days after the exposure. Both reactive and atrophied-like astrocytes expressed Kir4.1 in CA1/CA3 and the hilus of DG, respectively, indicating that these cells did not change their potential for normal activity at this time point of pathology. Together, the results demonstrate the persistence of two protoplasmic morphotypes of astrocytes, with distinct appearance, function, and fate after TMT-induced neurodegeneration, suggesting their pleiotropic roles in the hippocampal response to neurodegeneration. © 2019 IBRO",
journal = "Neuroscience",
title = "Two Distinct Hippocampal Astrocyte Morphotypes Reveal Subfield-Different Fate during Neurodegeneration Induced by Trimethyltin Intoxication",
volume = "423",
pages = "38-54",
doi = "10.1016/j.neuroscience.2019.10.022"
}

Dragić, M., Zarić, M., Mitrović, N. Lj., Nedeljković, N.,& Grković, I.. (2019). Two Distinct Hippocampal Astrocyte Morphotypes Reveal Subfield-Different Fate during Neurodegeneration Induced by Trimethyltin Intoxication. in Neuroscience, 423, 38-54.
https://doi.org/10.1016/j.neuroscience.2019.10.022

Dragić M, Zarić M, Mitrović NL, Nedeljković N, Grković I. Two Distinct Hippocampal Astrocyte Morphotypes Reveal Subfield-Different Fate during Neurodegeneration Induced by Trimethyltin Intoxication. in Neuroscience. 2019;423:38-54.
doi:10.1016/j.neuroscience.2019.10.022 .

Dragić, Milorad, Zarić, Marina, Mitrović, Nataša Lj., Nedeljković, Nadežda, Grković, Ivana, "Two Distinct Hippocampal Astrocyte Morphotypes Reveal Subfield-Different Fate during Neurodegeneration Induced by Trimethyltin Intoxication" in Neuroscience, 423 (2019):38-54,
https://doi.org/10.1016/j.neuroscience.2019.10.022 . .

TY  - JOUR
AU  - Mitrović, Nataša Lj.
AU  - Zarić, Marina
AU  - Drakulić, Dunja R.
AU  - Martinović, Jelena
AU  - Sevigny, Jean
AU  - Stanojlović, Miloš R.
AU  - Nedeljković, Nadežda
AU  - Grković, Ivana
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1459
AB  - 17 beta-Estradiol (E2) rapidly, by binding to membrane estrogen receptors, activates cell signaling cascades which induce formation of new dendritic spines in the hippocampus of males as in females, but the interaction with other metabolic processes, such as extracellular adenine nucleotides metabolism, are currently unknown. Extracellular adenine nucleotides play significant roles, controlling excitatory glutamatergic synapses and development of neural circuits and synaptic plasticity. Their precise regulation in the synaptic cleft is tightly controlled by ecto-nucleoside triphosphate diphosphohydrolase (NTPDase)/ecto-5-nucleotidase (eN) enzyme chain. Therefore, we sought to clarify whether a single systemic injection of E2 in male rats is accompanied by changes in the expression of the pre- and postsynaptic proteins and downstream kinases linked to E2-induced synaptic rearrangement as well as alterations in NTPDase/eN pathway in the hippocampal synaptosomes. Obtained data showed activation of mammalian target of rapamycin and upregulation of key synaptic proteins necessary for spine formation, 24 h after systemic E2 administration. In E2-mediated conditions, we found downregulation of NTPDase1 and NTPDase2 and attenuation of adenine nucleotide hydrolysis by NTPDase/eN enzyme chain, without changes in NTPDase3 properties and augmentation of synaptic tissue-nonspecific alkaline phosphatase (TNAP) activity. Despite reduced NTPDase activities, increased TNAP activity probably prevents toxic accumulation of ATP in the extracellular milieu and also hydrolyzes accumulated ADP due to unchanged NTPDase3 activity. Thus, our initial evaluation supports idea of specific roles of different ectonucleotidases and their coordinated actions in E2-mediated spine remodeling and maintenance.
T2  - Journal of Molecular Neuroscience
T1  - 17 beta-Estradiol-Induced Synaptic Rearrangements Are Accompanied by Altered Ectonucleotidase Activities in Male Rat Hippocampal Synaptosomes
VL  - 61
IS  - 3
SP  - 412
EP  - 422
DO  - 10.1007/s12031-016-0877-6
ER  - 

@article{
author = "Mitrović, Nataša Lj. and Zarić, Marina and Drakulić, Dunja R. and Martinović, Jelena and Sevigny, Jean and Stanojlović, Miloš R. and Nedeljković, Nadežda and Grković, Ivana",
year = "2017",
abstract = "17 beta-Estradiol (E2) rapidly, by binding to membrane estrogen receptors, activates cell signaling cascades which induce formation of new dendritic spines in the hippocampus of males as in females, but the interaction with other metabolic processes, such as extracellular adenine nucleotides metabolism, are currently unknown. Extracellular adenine nucleotides play significant roles, controlling excitatory glutamatergic synapses and development of neural circuits and synaptic plasticity. Their precise regulation in the synaptic cleft is tightly controlled by ecto-nucleoside triphosphate diphosphohydrolase (NTPDase)/ecto-5-nucleotidase (eN) enzyme chain. Therefore, we sought to clarify whether a single systemic injection of E2 in male rats is accompanied by changes in the expression of the pre- and postsynaptic proteins and downstream kinases linked to E2-induced synaptic rearrangement as well as alterations in NTPDase/eN pathway in the hippocampal synaptosomes. Obtained data showed activation of mammalian target of rapamycin and upregulation of key synaptic proteins necessary for spine formation, 24 h after systemic E2 administration. In E2-mediated conditions, we found downregulation of NTPDase1 and NTPDase2 and attenuation of adenine nucleotide hydrolysis by NTPDase/eN enzyme chain, without changes in NTPDase3 properties and augmentation of synaptic tissue-nonspecific alkaline phosphatase (TNAP) activity. Despite reduced NTPDase activities, increased TNAP activity probably prevents toxic accumulation of ATP in the extracellular milieu and also hydrolyzes accumulated ADP due to unchanged NTPDase3 activity. Thus, our initial evaluation supports idea of specific roles of different ectonucleotidases and their coordinated actions in E2-mediated spine remodeling and maintenance.",
journal = "Journal of Molecular Neuroscience",
title = "17 beta-Estradiol-Induced Synaptic Rearrangements Are Accompanied by Altered Ectonucleotidase Activities in Male Rat Hippocampal Synaptosomes",
volume = "61",
number = "3",
pages = "412-422",
doi = "10.1007/s12031-016-0877-6"
}

Mitrović, N. Lj., Zarić, M., Drakulić, D. R., Martinović, J., Sevigny, J., Stanojlović, M. R., Nedeljković, N.,& Grković, I.. (2017). 17 beta-Estradiol-Induced Synaptic Rearrangements Are Accompanied by Altered Ectonucleotidase Activities in Male Rat Hippocampal Synaptosomes. in Journal of Molecular Neuroscience, 61(3), 412-422.
https://doi.org/10.1007/s12031-016-0877-6

Mitrović NL, Zarić M, Drakulić DR, Martinović J, Sevigny J, Stanojlović MR, Nedeljković N, Grković I. 17 beta-Estradiol-Induced Synaptic Rearrangements Are Accompanied by Altered Ectonucleotidase Activities in Male Rat Hippocampal Synaptosomes. in Journal of Molecular Neuroscience. 2017;61(3):412-422.
doi:10.1007/s12031-016-0877-6 .

Mitrović, Nataša Lj., Zarić, Marina, Drakulić, Dunja R., Martinović, Jelena, Sevigny, Jean, Stanojlović, Miloš R., Nedeljković, Nadežda, Grković, Ivana, "17 beta-Estradiol-Induced Synaptic Rearrangements Are Accompanied by Altered Ectonucleotidase Activities in Male Rat Hippocampal Synaptosomes" in Journal of Molecular Neuroscience, 61, no. 3 (2017):412-422,
https://doi.org/10.1007/s12031-016-0877-6 . .

TY  - JOUR
AU  - Mitrović, Nataša Lj.
AU  - Zarić, Marina
AU  - Drakulić, Dunja R.
AU  - Martinović, Jelena
AU  - Sevigny, Jean
AU  - Stanojlović, Miloš R.
AU  - Nedeljković, Nadežda
AU  - Grković, Ivana
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1460
T2  - Journal of Molecular Neuroscience
T1  - Erratum to: 17 beta-Estradiol-Induced Synaptic Rearrangements Are Accompanied by Altered Ectonucleotidase Activities in Male Rat Hippocampal Synaptosomes
VL  - 61
IS  - 3
SP  - 423
EP  - 424
DO  - 10.1007/s12031-016-0879-4
ER  - 

@article{
author = "Mitrović, Nataša Lj. and Zarić, Marina and Drakulić, Dunja R. and Martinović, Jelena and Sevigny, Jean and Stanojlović, Miloš R. and Nedeljković, Nadežda and Grković, Ivana",
year = "2017",
journal = "Journal of Molecular Neuroscience",
title = "Erratum to: 17 beta-Estradiol-Induced Synaptic Rearrangements Are Accompanied by Altered Ectonucleotidase Activities in Male Rat Hippocampal Synaptosomes",
volume = "61",
number = "3",
pages = "423-424",
doi = "10.1007/s12031-016-0879-4"
}

Mitrović, N. Lj., Zarić, M., Drakulić, D. R., Martinović, J., Sevigny, J., Stanojlović, M. R., Nedeljković, N.,& Grković, I.. (2017). Erratum to: 17 beta-Estradiol-Induced Synaptic Rearrangements Are Accompanied by Altered Ectonucleotidase Activities in Male Rat Hippocampal Synaptosomes. in Journal of Molecular Neuroscience, 61(3), 423-424.
https://doi.org/10.1007/s12031-016-0879-4

Mitrović NL, Zarić M, Drakulić DR, Martinović J, Sevigny J, Stanojlović MR, Nedeljković N, Grković I. Erratum to: 17 beta-Estradiol-Induced Synaptic Rearrangements Are Accompanied by Altered Ectonucleotidase Activities in Male Rat Hippocampal Synaptosomes. in Journal of Molecular Neuroscience. 2017;61(3):423-424.
doi:10.1007/s12031-016-0879-4 .

Mitrović, Nataša Lj., Zarić, Marina, Drakulić, Dunja R., Martinović, Jelena, Sevigny, Jean, Stanojlović, Miloš R., Nedeljković, Nadežda, Grković, Ivana, "Erratum to: 17 beta-Estradiol-Induced Synaptic Rearrangements Are Accompanied by Altered Ectonucleotidase Activities in Male Rat Hippocampal Synaptosomes" in Journal of Molecular Neuroscience, 61, no. 3 (2017):423-424,
https://doi.org/10.1007/s12031-016-0879-4 . .

TY  - JOUR
AU  - Grković, Ivana
AU  - Bjelobaba, Ivana
AU  - Mitrović, Nataša Lj.
AU  - Lavrnja, Irena
AU  - Drakulić, Dunja R.
AU  - Martinović, Jelena
AU  - Stanojlović, Miloš R.
AU  - Horvat, Anica
AU  - Nedeljković, Nadežda
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1289
AB  - Nucleoside triphosphate diphosphohydrolase3 (NTPDase3) is membrane-bound ecto-enzyme which hydrolyzes extracellular ATP, thus modulating the function of purinergic receptors and the pattern of purinergic signaling. Here we analyzed the developmental expression of NTPDase3 in female hypothalamus, cerebral cortex and hippocampal formation at different postnatal ages (PD7-PD90) by qRT-PCR and immunohistochemistry. In hypothalamus and hippocampus, a similar developmental profile was seen: NTPDase3 gene expression was stable during postnatal development and increased in adults. In the cortex, upregulation of NTPDase3 mRNA expression was seen at PD15 and further increase was evidenced in adults. Immunohistochemical analysis at PD7 revealed faint neuronal NTPDase3 localization in a dorsal hypothalamus. The immunoreactivity (ir) gradually increased in PD15 and PD20, in clusters of cells in the lateral, ventral and dorsomedial hypothalamus. Furthermore, in PD20 animals, NTPDase3-ir was detected on short fibers in the posterior hypothalamic area, while in PD30 the fibers appeared progressively longer and markedly varicose. In adults, the strongest NTPDase3-ir was observed in collections of cells in dorsomedial hypothalamic nucleus, dorsal and lateral hypothalamus and in several thalamic areas, whereas the varicose fibers traversed entire diencephalon, particularly paraventricular thalamic nucleus, ventromedial and dorsomedial hypothalamic nuclei, the arcuate nucleus and the prefornical part of the lateral hypothalamus. The presumably ascending NTPDase3-ir fibers were first observed in PD20; their density and the varicose appearance increased until the adulthood. Prominent enhancement of NTPDase3-ir in the hypothalamus coincides with age when animals acquire diurnal rhythms of sleeping and feeding, supporting the hypothesis that this enzyme may be involved in regulation of homeostatic functions. (C) 2016 Elsevier B.V. All rights reserved.
T2  - Journal of Chemical Neuroanatomy
T1  - Expression of ecto-nucleoside triphosphate diphosphohydrolase3 (NTPDase3) in the female rat brain during postnatal development
VL  - 77
SP  - 10
EP  - 18
DO  - 10.1016/j.jchemneu.2016.04.001
ER  - 

@article{
author = "Grković, Ivana and Bjelobaba, Ivana and Mitrović, Nataša Lj. and Lavrnja, Irena and Drakulić, Dunja R. and Martinović, Jelena and Stanojlović, Miloš R. and Horvat, Anica and Nedeljković, Nadežda",
year = "2016",
abstract = "Nucleoside triphosphate diphosphohydrolase3 (NTPDase3) is membrane-bound ecto-enzyme which hydrolyzes extracellular ATP, thus modulating the function of purinergic receptors and the pattern of purinergic signaling. Here we analyzed the developmental expression of NTPDase3 in female hypothalamus, cerebral cortex and hippocampal formation at different postnatal ages (PD7-PD90) by qRT-PCR and immunohistochemistry. In hypothalamus and hippocampus, a similar developmental profile was seen: NTPDase3 gene expression was stable during postnatal development and increased in adults. In the cortex, upregulation of NTPDase3 mRNA expression was seen at PD15 and further increase was evidenced in adults. Immunohistochemical analysis at PD7 revealed faint neuronal NTPDase3 localization in a dorsal hypothalamus. The immunoreactivity (ir) gradually increased in PD15 and PD20, in clusters of cells in the lateral, ventral and dorsomedial hypothalamus. Furthermore, in PD20 animals, NTPDase3-ir was detected on short fibers in the posterior hypothalamic area, while in PD30 the fibers appeared progressively longer and markedly varicose. In adults, the strongest NTPDase3-ir was observed in collections of cells in dorsomedial hypothalamic nucleus, dorsal and lateral hypothalamus and in several thalamic areas, whereas the varicose fibers traversed entire diencephalon, particularly paraventricular thalamic nucleus, ventromedial and dorsomedial hypothalamic nuclei, the arcuate nucleus and the prefornical part of the lateral hypothalamus. The presumably ascending NTPDase3-ir fibers were first observed in PD20; their density and the varicose appearance increased until the adulthood. Prominent enhancement of NTPDase3-ir in the hypothalamus coincides with age when animals acquire diurnal rhythms of sleeping and feeding, supporting the hypothesis that this enzyme may be involved in regulation of homeostatic functions. (C) 2016 Elsevier B.V. All rights reserved.",
journal = "Journal of Chemical Neuroanatomy",
title = "Expression of ecto-nucleoside triphosphate diphosphohydrolase3 (NTPDase3) in the female rat brain during postnatal development",
volume = "77",
pages = "10-18",
doi = "10.1016/j.jchemneu.2016.04.001"
}

Grković, I., Bjelobaba, I., Mitrović, N. Lj., Lavrnja, I., Drakulić, D. R., Martinović, J., Stanojlović, M. R., Horvat, A.,& Nedeljković, N.. (2016). Expression of ecto-nucleoside triphosphate diphosphohydrolase3 (NTPDase3) in the female rat brain during postnatal development. in Journal of Chemical Neuroanatomy, 77, 10-18.
https://doi.org/10.1016/j.jchemneu.2016.04.001

Grković I, Bjelobaba I, Mitrović NL, Lavrnja I, Drakulić DR, Martinović J, Stanojlović MR, Horvat A, Nedeljković N. Expression of ecto-nucleoside triphosphate diphosphohydrolase3 (NTPDase3) in the female rat brain during postnatal development. in Journal of Chemical Neuroanatomy. 2016;77:10-18.
doi:10.1016/j.jchemneu.2016.04.001 .

Grković, Ivana, Bjelobaba, Ivana, Mitrović, Nataša Lj., Lavrnja, Irena, Drakulić, Dunja R., Martinović, Jelena, Stanojlović, Miloš R., Horvat, Anica, Nedeljković, Nadežda, "Expression of ecto-nucleoside triphosphate diphosphohydrolase3 (NTPDase3) in the female rat brain during postnatal development" in Journal of Chemical Neuroanatomy, 77 (2016):10-18,
https://doi.org/10.1016/j.jchemneu.2016.04.001 . .

TY  - JOUR
AU  - Mitrović, Nataša Lj.
AU  - Zarić, Marina
AU  - Drakulić, Dunja R.
AU  - Martinović, Jelena
AU  - Stanojlović, Miloš R.
AU  - Sevigny, Jean
AU  - Horvat, Anica
AU  - Nedeljković, Nadežda
AU  - Grković, Ivana
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1022
AB  - 17 beta-Estradiol (E2) crucially affects several processes in the hippocampus of both sexes. E2 acts upon estradiol receptors ER alpha and ER beta, influencing target gene expression and/or modulates intracellular signaling cascades. Another potent modulator of hippocampal function is nucleoside adenosine, the final product of ectonucleoti-dase cascade, enzymes which hydrolyze extracellular ATP to adenosine. The last and rate-limiting step of the hydrolysis is catalyzed by membrane-bound ecto-50-nucleotidase (eN). Previous findings obtained on adenosine metabolism in brain suggest that eN may be modulated by ovarian steroids. Therefore, the present study reports that the activity and protein abundance of membrane-bound eN fluctuates across the estrus cycle in the hippocampal synaptosomes of female rats. Further, we analyzed the role of E2 and its intracellular receptors on the expression of eN in ovariectomized females. We found that E2 upregulated eN activity and protein abundance in the hippocampal synaptosomes. Application of nonspecific ER antagonist, ICI 182,780 and selective ERa and ERb agonists, PPT and DPN, respectively, demonstrated the involvement of both receptor subtypes in observed actions. Selective ERa receptor agonist, PPT, induced upregulation of both the protein level and activity of eN, while application of selective ERb receptor agonist, DPN, increased only the activity of eN. In both cases, E2 entered into the intracellular compartment and activated ER(s), which was demonstrated by membrane impermeable E2-BSA conjugate. Together these results imply that E2-induced effects on connectivity and functional properties of the hippocampal synapses may be in part mediated through observed effect on eN. (C) 2016 IBRO. Published by Elsevier Ltd. All rights reserved.
PB  - Elsevier
T2  - Neuroscience
T1  - 17 beta-ESTRADIOL UPREGULATES ECTO-5 -NUCLEOTIDASE (CD73) IN HIPPOCAMPAL SYNAPTOSOMES OF FEMALE RATS THROUGH ACTION MEDIATED BY ESTROGEN RECEPTOR-alpha AND -beta
VL  - 324
SP  - 286
EP  - 296
DO  - 10.1016/j.neuroscience.2016.03.022
ER  - 

@article{
author = "Mitrović, Nataša Lj. and Zarić, Marina and Drakulić, Dunja R. and Martinović, Jelena and Stanojlović, Miloš R. and Sevigny, Jean and Horvat, Anica and Nedeljković, Nadežda and Grković, Ivana",
year = "2016",
abstract = "17 beta-Estradiol (E2) crucially affects several processes in the hippocampus of both sexes. E2 acts upon estradiol receptors ER alpha and ER beta, influencing target gene expression and/or modulates intracellular signaling cascades. Another potent modulator of hippocampal function is nucleoside adenosine, the final product of ectonucleoti-dase cascade, enzymes which hydrolyze extracellular ATP to adenosine. The last and rate-limiting step of the hydrolysis is catalyzed by membrane-bound ecto-50-nucleotidase (eN). Previous findings obtained on adenosine metabolism in brain suggest that eN may be modulated by ovarian steroids. Therefore, the present study reports that the activity and protein abundance of membrane-bound eN fluctuates across the estrus cycle in the hippocampal synaptosomes of female rats. Further, we analyzed the role of E2 and its intracellular receptors on the expression of eN in ovariectomized females. We found that E2 upregulated eN activity and protein abundance in the hippocampal synaptosomes. Application of nonspecific ER antagonist, ICI 182,780 and selective ERa and ERb agonists, PPT and DPN, respectively, demonstrated the involvement of both receptor subtypes in observed actions. Selective ERa receptor agonist, PPT, induced upregulation of both the protein level and activity of eN, while application of selective ERb receptor agonist, DPN, increased only the activity of eN. In both cases, E2 entered into the intracellular compartment and activated ER(s), which was demonstrated by membrane impermeable E2-BSA conjugate. Together these results imply that E2-induced effects on connectivity and functional properties of the hippocampal synapses may be in part mediated through observed effect on eN. (C) 2016 IBRO. Published by Elsevier Ltd. All rights reserved.",
publisher = "Elsevier",
journal = "Neuroscience",
title = "17 beta-ESTRADIOL UPREGULATES ECTO-5 -NUCLEOTIDASE (CD73) IN HIPPOCAMPAL SYNAPTOSOMES OF FEMALE RATS THROUGH ACTION MEDIATED BY ESTROGEN RECEPTOR-alpha AND -beta",
volume = "324",
pages = "286-296",
doi = "10.1016/j.neuroscience.2016.03.022"
}

Mitrović, N. Lj., Zarić, M., Drakulić, D. R., Martinović, J., Stanojlović, M. R., Sevigny, J., Horvat, A., Nedeljković, N.,& Grković, I.. (2016). 17 beta-ESTRADIOL UPREGULATES ECTO-5 -NUCLEOTIDASE (CD73) IN HIPPOCAMPAL SYNAPTOSOMES OF FEMALE RATS THROUGH ACTION MEDIATED BY ESTROGEN RECEPTOR-alpha AND -beta. in Neuroscience
Elsevier., 324, 286-296.
https://doi.org/10.1016/j.neuroscience.2016.03.022

Mitrović NL, Zarić M, Drakulić DR, Martinović J, Stanojlović MR, Sevigny J, Horvat A, Nedeljković N, Grković I. 17 beta-ESTRADIOL UPREGULATES ECTO-5 -NUCLEOTIDASE (CD73) IN HIPPOCAMPAL SYNAPTOSOMES OF FEMALE RATS THROUGH ACTION MEDIATED BY ESTROGEN RECEPTOR-alpha AND -beta. in Neuroscience. 2016;324:286-296.
doi:10.1016/j.neuroscience.2016.03.022 .

Mitrović, Nataša Lj., Zarić, Marina, Drakulić, Dunja R., Martinović, Jelena, Stanojlović, Miloš R., Sevigny, Jean, Horvat, Anica, Nedeljković, Nadežda, Grković, Ivana, "17 beta-ESTRADIOL UPREGULATES ECTO-5 -NUCLEOTIDASE (CD73) IN HIPPOCAMPAL SYNAPTOSOMES OF FEMALE RATS THROUGH ACTION MEDIATED BY ESTROGEN RECEPTOR-alpha AND -beta" in Neuroscience, 324 (2016):286-296,
https://doi.org/10.1016/j.neuroscience.2016.03.022 . .

TY  - JOUR
AU  - Mitrović, Nataša Lj.
AU  - Guševac, Ivana
AU  - Drakulić, Dunja R.
AU  - Stanojlović, Miloš R.
AU  - Martinović, Jelena
AU  - Sevigny, Jean
AU  - Horvat, Anica
AU  - Nedeljković, Nadežda
AU  - Grković, Ivana
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1222
AB  - Ecto-5-nucleotidase (eN), a membrane rate-limiting enzyme of the purine catabolic pathway, catalyzes the conversion of AMP to adenosine involved in the regulation of many brain physiological and pathological processes. Since gender fundamentally determines hormonal milieu in the body and brain, it is reasonable to assume that sex differences in the activity of various signaling systems, including adenosine, may be generated by gonadal steroids. Thus, we examined expression of eN as a component of adenosine signaling system in the basal state in cerebral cortex and hippocampus of male and female rats at gene, protein and functional level, as well as in the state of gonadal hormone deprivation, induced by ovariectomy (OVX), whereas impact of steroid hormones was explored after repeated administration of 17 alpha-estradiol, 17 beta-estradiol and progesterone for seven consecutive days. Results showed regional and sex-related differences in basal eN activity level, with the highest AMP hydrolysis observed in the hippocampus of male rats. Furthermore, ovarian steroids do not contribute to basal gene eN expression or the activity in cortical and hippocampal region of female rats. However, protein eN expression was increased in OVX rats in both investigated region. Investigated exogenous steroids had no influence on eN expression in male brain, while in OVX females alterations in eN activity were induced. The observed effects in female rats were different between examined regions e.g. in cortex, applied treatments predominantly decreased whereas in hippocampus increased eN activity. Based on the presented results, eN exerts regional and sex-related response in basal state as well as after treatment with female gonadal hormones, however the exact mechanisms of sex steroids actions on eN remain unclear and should be fully explored. (C) 2016 Elsevier Inc. All rights reserved.
T2  - General and Comparative Endocrinology
T1  - Regional and sex-related differences in modulating effects of female sex steroids on ecto-5-nucleotidase expression in the rat cerebral cortex and hippocampus
VL  - 235
SP  - 100
EP  - 107
DO  - 10.1016/j.ygcen.2016.06.018
ER  - 

@article{
author = "Mitrović, Nataša Lj. and Guševac, Ivana and Drakulić, Dunja R. and Stanojlović, Miloš R. and Martinović, Jelena and Sevigny, Jean and Horvat, Anica and Nedeljković, Nadežda and Grković, Ivana",
year = "2016",
abstract = "Ecto-5-nucleotidase (eN), a membrane rate-limiting enzyme of the purine catabolic pathway, catalyzes the conversion of AMP to adenosine involved in the regulation of many brain physiological and pathological processes. Since gender fundamentally determines hormonal milieu in the body and brain, it is reasonable to assume that sex differences in the activity of various signaling systems, including adenosine, may be generated by gonadal steroids. Thus, we examined expression of eN as a component of adenosine signaling system in the basal state in cerebral cortex and hippocampus of male and female rats at gene, protein and functional level, as well as in the state of gonadal hormone deprivation, induced by ovariectomy (OVX), whereas impact of steroid hormones was explored after repeated administration of 17 alpha-estradiol, 17 beta-estradiol and progesterone for seven consecutive days. Results showed regional and sex-related differences in basal eN activity level, with the highest AMP hydrolysis observed in the hippocampus of male rats. Furthermore, ovarian steroids do not contribute to basal gene eN expression or the activity in cortical and hippocampal region of female rats. However, protein eN expression was increased in OVX rats in both investigated region. Investigated exogenous steroids had no influence on eN expression in male brain, while in OVX females alterations in eN activity were induced. The observed effects in female rats were different between examined regions e.g. in cortex, applied treatments predominantly decreased whereas in hippocampus increased eN activity. Based on the presented results, eN exerts regional and sex-related response in basal state as well as after treatment with female gonadal hormones, however the exact mechanisms of sex steroids actions on eN remain unclear and should be fully explored. (C) 2016 Elsevier Inc. All rights reserved.",
journal = "General and Comparative Endocrinology",
title = "Regional and sex-related differences in modulating effects of female sex steroids on ecto-5-nucleotidase expression in the rat cerebral cortex and hippocampus",
volume = "235",
pages = "100-107",
doi = "10.1016/j.ygcen.2016.06.018"
}

Mitrović, N. Lj., Guševac, I., Drakulić, D. R., Stanojlović, M. R., Martinović, J., Sevigny, J., Horvat, A., Nedeljković, N.,& Grković, I.. (2016). Regional and sex-related differences in modulating effects of female sex steroids on ecto-5-nucleotidase expression in the rat cerebral cortex and hippocampus. in General and Comparative Endocrinology, 235, 100-107.
https://doi.org/10.1016/j.ygcen.2016.06.018

Mitrović NL, Guševac I, Drakulić DR, Stanojlović MR, Martinović J, Sevigny J, Horvat A, Nedeljković N, Grković I. Regional and sex-related differences in modulating effects of female sex steroids on ecto-5-nucleotidase expression in the rat cerebral cortex and hippocampus. in General and Comparative Endocrinology. 2016;235:100-107.
doi:10.1016/j.ygcen.2016.06.018 .

Mitrović, Nataša Lj., Guševac, Ivana, Drakulić, Dunja R., Stanojlović, Miloš R., Martinović, Jelena, Sevigny, Jean, Horvat, Anica, Nedeljković, Nadežda, Grković, Ivana, "Regional and sex-related differences in modulating effects of female sex steroids on ecto-5-nucleotidase expression in the rat cerebral cortex and hippocampus" in General and Comparative Endocrinology, 235 (2016):100-107,
https://doi.org/10.1016/j.ygcen.2016.06.018 . .

TY  - JOUR
AU  - Laketa, Danijela
AU  - Savić, Jasmina
AU  - Bjelobaba, Ivana
AU  - Lavrnja, Irene
AU  - Vasić, Vesna M.
AU  - Stojiljković, Mirjana
AU  - Nedeljković, Nadežda
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/385
AB  - Background: Cortical stab injury (CSI) induces changes in the activity, expression and cellular distribution of specific ectonucleotidases at the injury site. Also, several experimentally induced neuropathologies are associated with changes in soluble ectonucleotidase activities in the plasma and serum, whilst various insults to the brain alter purine compounds levels in cerebrospinal fluid, but also in serum, indicating that insults to the brain may induce alterations in nucleotides release and rate of their hydrolysis in the vascular system. Since adenine nucleotides and adenosine regulate diverse cellular functions in the vascular system, including vascular tone, platelet aggregation and inflammatory responses of lymphocytes and macrophages, alterations of ectonucleotidase activities in the vascular system may be relevant for the clinical outcome of the primary insult. Methods: We explored ectonucleotidase activities using specific enzyme assays and determined adenine nucleotides concentrations by the UPLC method in the rat serum after cortical stab injury. Results: At 4-h post-injury, ATP and AMP hydrolysis increased by about 60% and 40%, respectively, while phosphodiesterase activity remained unchanged. Also, at 4-h postinjury a marked decrease in ATP concentration and more than 2-fold increase in AMP concentration were recorded. Conclusions: CSI induces rapid up-regulation of nucleotide catabolizing soluble ectonucleotidases in rat serum, which leads to the observed shift in serum nucleotide levels. The results obtained imply that ectonucleotidases and adenine nucleotides participate in the communication between the brain and the vascular system in physiological and pathological conditions and thereby may be involved in the development of various human neuropathologies.
T2  - Journal of Medical Biochemistry
T1  - Brain Injury Alters Ectonucleotidase Activities and Adenine Nucleotide Levels in Rat Serum
VL  - 34
IS  - 2
SP  - 215
EP  - 222
DO  - 10.2478/jomb-2014-0025
ER  - 

@article{
author = "Laketa, Danijela and Savić, Jasmina and Bjelobaba, Ivana and Lavrnja, Irene and Vasić, Vesna M. and Stojiljković, Mirjana and Nedeljković, Nadežda",
year = "2015",
abstract = "Background: Cortical stab injury (CSI) induces changes in the activity, expression and cellular distribution of specific ectonucleotidases at the injury site. Also, several experimentally induced neuropathologies are associated with changes in soluble ectonucleotidase activities in the plasma and serum, whilst various insults to the brain alter purine compounds levels in cerebrospinal fluid, but also in serum, indicating that insults to the brain may induce alterations in nucleotides release and rate of their hydrolysis in the vascular system. Since adenine nucleotides and adenosine regulate diverse cellular functions in the vascular system, including vascular tone, platelet aggregation and inflammatory responses of lymphocytes and macrophages, alterations of ectonucleotidase activities in the vascular system may be relevant for the clinical outcome of the primary insult. Methods: We explored ectonucleotidase activities using specific enzyme assays and determined adenine nucleotides concentrations by the UPLC method in the rat serum after cortical stab injury. Results: At 4-h post-injury, ATP and AMP hydrolysis increased by about 60% and 40%, respectively, while phosphodiesterase activity remained unchanged. Also, at 4-h postinjury a marked decrease in ATP concentration and more than 2-fold increase in AMP concentration were recorded. Conclusions: CSI induces rapid up-regulation of nucleotide catabolizing soluble ectonucleotidases in rat serum, which leads to the observed shift in serum nucleotide levels. The results obtained imply that ectonucleotidases and adenine nucleotides participate in the communication between the brain and the vascular system in physiological and pathological conditions and thereby may be involved in the development of various human neuropathologies.",
journal = "Journal of Medical Biochemistry",
title = "Brain Injury Alters Ectonucleotidase Activities and Adenine Nucleotide Levels in Rat Serum",
volume = "34",
number = "2",
pages = "215-222",
doi = "10.2478/jomb-2014-0025"
}

Laketa, D., Savić, J., Bjelobaba, I., Lavrnja, I., Vasić, V. M., Stojiljković, M.,& Nedeljković, N.. (2015). Brain Injury Alters Ectonucleotidase Activities and Adenine Nucleotide Levels in Rat Serum. in Journal of Medical Biochemistry, 34(2), 215-222.
https://doi.org/10.2478/jomb-2014-0025

Laketa D, Savić J, Bjelobaba I, Lavrnja I, Vasić VM, Stojiljković M, Nedeljković N. Brain Injury Alters Ectonucleotidase Activities and Adenine Nucleotide Levels in Rat Serum. in Journal of Medical Biochemistry. 2015;34(2):215-222.
doi:10.2478/jomb-2014-0025 .

Laketa, Danijela, Savić, Jasmina, Bjelobaba, Ivana, Lavrnja, Irene, Vasić, Vesna M., Stojiljković, Mirjana, Nedeljković, Nadežda, "Brain Injury Alters Ectonucleotidase Activities and Adenine Nucleotide Levels in Rat Serum" in Journal of Medical Biochemistry, 34, no. 2 (2015):215-222,
https://doi.org/10.2478/jomb-2014-0025 . .

TY  - JOUR
AU  - Drakulić, Dunja R.
AU  - Stanojlović, Miloš R.
AU  - Nedeljković, Nadežda
AU  - Grković, Ivana
AU  - Velickovic, Natasa
AU  - Guševac, Ivana
AU  - Mitrović, Nataša Lj.
AU  - Buzadzic, Ivana
AU  - Horvat, Anica
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/446
AB  - Although dexamethasone (DEX), a synthetic glucocorticoid receptor (GR) analog with profound effects on energy metabolism, immune system, and hypothalamic-pituitary-adrenal axis, is widely used therapeutically, its impact on the brain is poorly understood. The aim of the present study was to explore the effect of repeated low-dose DEX administration on the activity and expression of the ectonucleotidase enzymes which hydrolyze and therefore control extracellular ATP and adenosine concentrations in the synaptic cleft. Ectonucleotidases tested were ectonucleoside triphosphate diphosphohydrolase 1-3 (NTPDase1-3) and ecto-5-nucleotidase (eN), whereas the effects were evaluated in two brain areas that show different sensitivity to glucocorticoid action, hippocampus, and cerebral cortex. In the hippocampus, but not in cerebral cortex, modest level of neurodegenerative changes as well as increase in ATP, ADP, and AMP hydrolysis and upregulation of NTPDase1 and eN mRNA expression ensued under the influence of DEX. The observed pattern of ectonucleotidase activation, which creates tissue volume with enhanced capacity for adenosine formation, is the hallmark of the response after different insults to the brain.
T2  - Journal of Molecular Neuroscience
T1  - Upregulation of Nucleoside Triphosphate Diphosphohydrolase-1 and Ecto-5-Nucleotidase in Rat Hippocampus after Repeated Low-Dose Dexamethasone Administration
VL  - 55
IS  - 4
SP  - 959
EP  - 967
DO  - 10.1007/s12031-014-0452-y
ER  - 

@article{
author = "Drakulić, Dunja R. and Stanojlović, Miloš R. and Nedeljković, Nadežda and Grković, Ivana and Velickovic, Natasa and Guševac, Ivana and Mitrović, Nataša Lj. and Buzadzic, Ivana and Horvat, Anica",
year = "2015",
abstract = "Although dexamethasone (DEX), a synthetic glucocorticoid receptor (GR) analog with profound effects on energy metabolism, immune system, and hypothalamic-pituitary-adrenal axis, is widely used therapeutically, its impact on the brain is poorly understood. The aim of the present study was to explore the effect of repeated low-dose DEX administration on the activity and expression of the ectonucleotidase enzymes which hydrolyze and therefore control extracellular ATP and adenosine concentrations in the synaptic cleft. Ectonucleotidases tested were ectonucleoside triphosphate diphosphohydrolase 1-3 (NTPDase1-3) and ecto-5-nucleotidase (eN), whereas the effects were evaluated in two brain areas that show different sensitivity to glucocorticoid action, hippocampus, and cerebral cortex. In the hippocampus, but not in cerebral cortex, modest level of neurodegenerative changes as well as increase in ATP, ADP, and AMP hydrolysis and upregulation of NTPDase1 and eN mRNA expression ensued under the influence of DEX. The observed pattern of ectonucleotidase activation, which creates tissue volume with enhanced capacity for adenosine formation, is the hallmark of the response after different insults to the brain.",
journal = "Journal of Molecular Neuroscience",
title = "Upregulation of Nucleoside Triphosphate Diphosphohydrolase-1 and Ecto-5-Nucleotidase in Rat Hippocampus after Repeated Low-Dose Dexamethasone Administration",
volume = "55",
number = "4",
pages = "959-967",
doi = "10.1007/s12031-014-0452-y"
}

Drakulić, D. R., Stanojlović, M. R., Nedeljković, N., Grković, I., Velickovic, N., Guševac, I., Mitrović, N. Lj., Buzadzic, I.,& Horvat, A.. (2015). Upregulation of Nucleoside Triphosphate Diphosphohydrolase-1 and Ecto-5-Nucleotidase in Rat Hippocampus after Repeated Low-Dose Dexamethasone Administration. in Journal of Molecular Neuroscience, 55(4), 959-967.
https://doi.org/10.1007/s12031-014-0452-y

Drakulić DR, Stanojlović MR, Nedeljković N, Grković I, Velickovic N, Guševac I, Mitrović NL, Buzadzic I, Horvat A. Upregulation of Nucleoside Triphosphate Diphosphohydrolase-1 and Ecto-5-Nucleotidase in Rat Hippocampus after Repeated Low-Dose Dexamethasone Administration. in Journal of Molecular Neuroscience. 2015;55(4):959-967.
doi:10.1007/s12031-014-0452-y .

Drakulić, Dunja R., Stanojlović, Miloš R., Nedeljković, Nadežda, Grković, Ivana, Velickovic, Natasa, Guševac, Ivana, Mitrović, Nataša Lj., Buzadzic, Ivana, Horvat, Anica, "Upregulation of Nucleoside Triphosphate Diphosphohydrolase-1 and Ecto-5-Nucleotidase in Rat Hippocampus after Repeated Low-Dose Dexamethasone Administration" in Journal of Molecular Neuroscience, 55, no. 4 (2015):959-967,
https://doi.org/10.1007/s12031-014-0452-y . .

TY  - JOUR
AU  - Grković, Ivana
AU  - Bjelobaba, Ivana
AU  - Nedeljković, Nadežda
AU  - Mitrović, Nataša Lj.
AU  - Drakulić, Dunja R.
AU  - Stanojlović, Miloš R.
AU  - Horvat, Anica
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/64
AB  - Ecto-5-nucleotidase (e-5NT), a glycosylphosphatidylinositol-linked membrane protein, catalyzes a conversion of AMP to adenosine, which influences nearly every aspect of brain physiology, including embryonic and postnatal brain development. The present study aimed to investigate a pattern of expression, activity and kinetic properties of e-5NT in the hippocampal formation and synaptic plasma membrane (SPM) preparations in rats at postnatal days (PDs) 7, 15, 20, 30 and 90. By combining gene expression analysis and enzyme histochemistry, we observed that e-5NT mRNA reached the adult level at PD20, while the enzyme activity continued to increase beyond this age. Further analysis revealed that hippocampal layers rich in synapses expressed the highest levels of e-5NT activity, while in layers populated with neuronal cell bodies, the enzyme activity was weak or absent. Therefore, activity and expression of e-5NT were analyzed in SPM preparations isolated from rats at different ages. The presence of two protein bands of about 65 and 68 kDa was determined by immunoblot analysis. The 65-kDa band was present at all ages, and its abundance increased from PD7 to PD20. The 68-kDa band appeared at PD15 and increased until PD30, coinciding with the increase of e-5NT activity, substrate affinity and enzymatic efficiency. Since distinct e-5NT isoforms may derive from different patterns of the enzyme protein N-glycosylation, we speculate that long-term regulation of e-5NT activity in adulthood may be effectuated at posttranslational level and without overall change in the gene and protein expression.
T2  - Journal of Molecular Neuroscience
T1  - Developmental Increase in Ecto-5-Nucleotidase Activity Overlaps with Appearance of Two Immunologically Distinct Enzyme Isoforms in Rat Hippocampal Synaptic Plasma Membranes
VL  - 54
IS  - 1
SP  - 109
EP  - 118
DO  - 10.1007/s12031-014-0256-0
ER  - 

@article{
author = "Grković, Ivana and Bjelobaba, Ivana and Nedeljković, Nadežda and Mitrović, Nataša Lj. and Drakulić, Dunja R. and Stanojlović, Miloš R. and Horvat, Anica",
year = "2014",
abstract = "Ecto-5-nucleotidase (e-5NT), a glycosylphosphatidylinositol-linked membrane protein, catalyzes a conversion of AMP to adenosine, which influences nearly every aspect of brain physiology, including embryonic and postnatal brain development. The present study aimed to investigate a pattern of expression, activity and kinetic properties of e-5NT in the hippocampal formation and synaptic plasma membrane (SPM) preparations in rats at postnatal days (PDs) 7, 15, 20, 30 and 90. By combining gene expression analysis and enzyme histochemistry, we observed that e-5NT mRNA reached the adult level at PD20, while the enzyme activity continued to increase beyond this age. Further analysis revealed that hippocampal layers rich in synapses expressed the highest levels of e-5NT activity, while in layers populated with neuronal cell bodies, the enzyme activity was weak or absent. Therefore, activity and expression of e-5NT were analyzed in SPM preparations isolated from rats at different ages. The presence of two protein bands of about 65 and 68 kDa was determined by immunoblot analysis. The 65-kDa band was present at all ages, and its abundance increased from PD7 to PD20. The 68-kDa band appeared at PD15 and increased until PD30, coinciding with the increase of e-5NT activity, substrate affinity and enzymatic efficiency. Since distinct e-5NT isoforms may derive from different patterns of the enzyme protein N-glycosylation, we speculate that long-term regulation of e-5NT activity in adulthood may be effectuated at posttranslational level and without overall change in the gene and protein expression.",
journal = "Journal of Molecular Neuroscience",
title = "Developmental Increase in Ecto-5-Nucleotidase Activity Overlaps with Appearance of Two Immunologically Distinct Enzyme Isoforms in Rat Hippocampal Synaptic Plasma Membranes",
volume = "54",
number = "1",
pages = "109-118",
doi = "10.1007/s12031-014-0256-0"
}

Grković, I., Bjelobaba, I., Nedeljković, N., Mitrović, N. Lj., Drakulić, D. R., Stanojlović, M. R.,& Horvat, A.. (2014). Developmental Increase in Ecto-5-Nucleotidase Activity Overlaps with Appearance of Two Immunologically Distinct Enzyme Isoforms in Rat Hippocampal Synaptic Plasma Membranes. in Journal of Molecular Neuroscience, 54(1), 109-118.
https://doi.org/10.1007/s12031-014-0256-0

Grković I, Bjelobaba I, Nedeljković N, Mitrović NL, Drakulić DR, Stanojlović MR, Horvat A. Developmental Increase in Ecto-5-Nucleotidase Activity Overlaps with Appearance of Two Immunologically Distinct Enzyme Isoforms in Rat Hippocampal Synaptic Plasma Membranes. in Journal of Molecular Neuroscience. 2014;54(1):109-118.
doi:10.1007/s12031-014-0256-0 .

Grković, Ivana, Bjelobaba, Ivana, Nedeljković, Nadežda, Mitrović, Nataša Lj., Drakulić, Dunja R., Stanojlović, Miloš R., Horvat, Anica, "Developmental Increase in Ecto-5-Nucleotidase Activity Overlaps with Appearance of Two Immunologically Distinct Enzyme Isoforms in Rat Hippocampal Synaptic Plasma Membranes" in Journal of Molecular Neuroscience, 54, no. 1 (2014):109-118,
https://doi.org/10.1007/s12031-014-0256-0 . .

TY  - JOUR
AU  - Stanojević, Ivana
AU  - Bjelobaba, Ivana
AU  - Nedeljković, Nadežda
AU  - Drakulić, Dunja R.
AU  - Petrović, Snježana
AU  - Stojiljković, Mirjana
AU  - Horvat, Anica
PY  - 2011
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4376
AB  - Ecto-5-nucleotidase (CD73; EC 3.1.3.5, e-5NT) is regarded as the key enzyme in the extracellular formation of adenosine, which acts as a neuromodulator and important trophic and homeostatic factor in the brain. In the present study, we have investigated e-5NT activity, kinetic properties concerning AMP hydrolysis and the enzyme protein abundance in the purified synaptic plasma membrane (SPM) preparations isolated from whole female rat brain at different ages. We observed pronounced increase in AMP hydrolyzing activity in SPM during maturation, with greatest increment between juvenile (15-day-old) and pre-pubertal (30-day-old) rats. Immunodetection of e-5NT protein in the SPM displayed the reverse pattern of expression, with the maximum relative abundance at juvenile and minimum relative abundance in the adult stage. Negative correlation between the enzyme activity and the enzyme protein abundance in the SPM indicates that e-5NT has additional roles in the synaptic compartment during postnatal brain development, other than those related to AMP hydrolysis. Determination of kinetic parameters, K(m) and V(max), suggested that the increase in the enzyme activity with maturation was entirely due to the increase in the enzyme catalytic efficiency (V(max)/K(m)). Finally, double immunofluorescence staining against e-5NT and presynaptic membrane marker syntaxin provided first direct evidence for the existence of this ecto-enzyme in the presynaptic compartment. The results of the study suggest that e-5NT may be a part of general scheme of brain development and synapse maturation and provide rationale for the previously reported inconsistencies between enzyme immunohistochemical and biochemical studies concerning localization of e-5NT in the brain. (C) 2011 ISDN. Published by Elsevier Ltd. All rights reserved.
T2  - International Journal of Developmental Neuroscience
T1  - Ontogenetic profile of ecto-5 -nucleotidase in rat brain synaptic plasma membranes
VL  - 29
IS  - 4
SP  - 397
EP  - 403
DO  - 10.1016/j.ijdevneu.2011.03.003
ER  - 

@article{
author = "Stanojević, Ivana and Bjelobaba, Ivana and Nedeljković, Nadežda and Drakulić, Dunja R. and Petrović, Snježana and Stojiljković, Mirjana and Horvat, Anica",
year = "2011",
abstract = "Ecto-5-nucleotidase (CD73; EC 3.1.3.5, e-5NT) is regarded as the key enzyme in the extracellular formation of adenosine, which acts as a neuromodulator and important trophic and homeostatic factor in the brain. In the present study, we have investigated e-5NT activity, kinetic properties concerning AMP hydrolysis and the enzyme protein abundance in the purified synaptic plasma membrane (SPM) preparations isolated from whole female rat brain at different ages. We observed pronounced increase in AMP hydrolyzing activity in SPM during maturation, with greatest increment between juvenile (15-day-old) and pre-pubertal (30-day-old) rats. Immunodetection of e-5NT protein in the SPM displayed the reverse pattern of expression, with the maximum relative abundance at juvenile and minimum relative abundance in the adult stage. Negative correlation between the enzyme activity and the enzyme protein abundance in the SPM indicates that e-5NT has additional roles in the synaptic compartment during postnatal brain development, other than those related to AMP hydrolysis. Determination of kinetic parameters, K(m) and V(max), suggested that the increase in the enzyme activity with maturation was entirely due to the increase in the enzyme catalytic efficiency (V(max)/K(m)). Finally, double immunofluorescence staining against e-5NT and presynaptic membrane marker syntaxin provided first direct evidence for the existence of this ecto-enzyme in the presynaptic compartment. The results of the study suggest that e-5NT may be a part of general scheme of brain development and synapse maturation and provide rationale for the previously reported inconsistencies between enzyme immunohistochemical and biochemical studies concerning localization of e-5NT in the brain. (C) 2011 ISDN. Published by Elsevier Ltd. All rights reserved.",
journal = "International Journal of Developmental Neuroscience",
title = "Ontogenetic profile of ecto-5 -nucleotidase in rat brain synaptic plasma membranes",
volume = "29",
number = "4",
pages = "397-403",
doi = "10.1016/j.ijdevneu.2011.03.003"
}

Stanojević, I., Bjelobaba, I., Nedeljković, N., Drakulić, D. R., Petrović, S., Stojiljković, M.,& Horvat, A.. (2011). Ontogenetic profile of ecto-5 -nucleotidase in rat brain synaptic plasma membranes. in International Journal of Developmental Neuroscience, 29(4), 397-403.
https://doi.org/10.1016/j.ijdevneu.2011.03.003

Stanojević I, Bjelobaba I, Nedeljković N, Drakulić DR, Petrović S, Stojiljković M, Horvat A. Ontogenetic profile of ecto-5 -nucleotidase in rat brain synaptic plasma membranes. in International Journal of Developmental Neuroscience. 2011;29(4):397-403.
doi:10.1016/j.ijdevneu.2011.03.003 .

Stanojević, Ivana, Bjelobaba, Ivana, Nedeljković, Nadežda, Drakulić, Dunja R., Petrović, Snježana, Stojiljković, Mirjana, Horvat, Anica, "Ontogenetic profile of ecto-5 -nucleotidase in rat brain synaptic plasma membranes" in International Journal of Developmental Neuroscience, 29, no. 4 (2011):397-403,
https://doi.org/10.1016/j.ijdevneu.2011.03.003 . .

TY  - JOUR
AU  - Laketa, Danijela
AU  - Bjelobaba, Ivana
AU  - Savić, Jasmina
AU  - Lavrnja, Irena
AU  - Stojiljković, Mirjana
AU  - Rakić, Ljubisav
AU  - Nedeljković, Nadežda
PY  - 2010
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3996
AB  - Biochemical properties of nucleotide pyrophosphatase/phosphodiesterase (NPP) in rat serum have been described by assessing its nucleotide phosphodiesterase activity, using p-nitrophenyl-5-thymidine monophosphate (p-Nph-5-TMP) as a substrate. It was demonstrated that NPP activity shares some typical characteristics described for other soluble NPP, such as divalent cation dependence, strong alkaline pH optimum (pH 10.5), inhibition by glycosaminoglycans, and K (m) for p-Nph-5-TMP hydrolysis of 61.8 +/- A 5.2 mu M. In order to characterize the relation between phosphodiesterase and pyrophosphatase activities of NPP, we have analyzed the effects of different natural nucleotides and nucleotide analogs. ATP, ADP, and AMP competitively inhibited p-Nph-5-TMP hydrolysis with K (i) values ranging 13-43 mu M. Nucleotide analogs, alpha,beta-metATP, BzATP, 2-MeSATP, and dialATP behaved as competitive inhibitors, whereas alpha,beta-metADP induced mixed inhibition, with K (i) ranging from 2 to 20 mu M. Chromatographic analysis revealed that alpha,beta-metATP, BzATP, and 2-MeSATP were catalytically degraded in the serum, whereas dialATP and alpha,beta-metADP resisted hydrolysis, implying that the former act as substrates and the latter as true competitive inhibitors of serum NPP activity. Since NPP activity is involved in generation, breakdown, and recycling of extracellular adenine nucleotides in the vascular compartment, the results suggest that both hydrolyzable and non-hydrolyzable nucleotide analogs could alter the amplitude and direction of ATP actions and could have potential therapeutic application.
T2  - Molecular and Cellular Biochemistry
T1  - Biochemical characterization of soluble nucleotide pyrophosphatase/phosphodiesterase activity in rat serum
VL  - 339
IS  - 1-2
SP  - 99
EP  - 106
DO  - 10.1007/s11010-009-0373-1
ER  - 

@article{
author = "Laketa, Danijela and Bjelobaba, Ivana and Savić, Jasmina and Lavrnja, Irena and Stojiljković, Mirjana and Rakić, Ljubisav and Nedeljković, Nadežda",
year = "2010",
abstract = "Biochemical properties of nucleotide pyrophosphatase/phosphodiesterase (NPP) in rat serum have been described by assessing its nucleotide phosphodiesterase activity, using p-nitrophenyl-5-thymidine monophosphate (p-Nph-5-TMP) as a substrate. It was demonstrated that NPP activity shares some typical characteristics described for other soluble NPP, such as divalent cation dependence, strong alkaline pH optimum (pH 10.5), inhibition by glycosaminoglycans, and K (m) for p-Nph-5-TMP hydrolysis of 61.8 +/- A 5.2 mu M. In order to characterize the relation between phosphodiesterase and pyrophosphatase activities of NPP, we have analyzed the effects of different natural nucleotides and nucleotide analogs. ATP, ADP, and AMP competitively inhibited p-Nph-5-TMP hydrolysis with K (i) values ranging 13-43 mu M. Nucleotide analogs, alpha,beta-metATP, BzATP, 2-MeSATP, and dialATP behaved as competitive inhibitors, whereas alpha,beta-metADP induced mixed inhibition, with K (i) ranging from 2 to 20 mu M. Chromatographic analysis revealed that alpha,beta-metATP, BzATP, and 2-MeSATP were catalytically degraded in the serum, whereas dialATP and alpha,beta-metADP resisted hydrolysis, implying that the former act as substrates and the latter as true competitive inhibitors of serum NPP activity. Since NPP activity is involved in generation, breakdown, and recycling of extracellular adenine nucleotides in the vascular compartment, the results suggest that both hydrolyzable and non-hydrolyzable nucleotide analogs could alter the amplitude and direction of ATP actions and could have potential therapeutic application.",
journal = "Molecular and Cellular Biochemistry",
title = "Biochemical characterization of soluble nucleotide pyrophosphatase/phosphodiesterase activity in rat serum",
volume = "339",
number = "1-2",
pages = "99-106",
doi = "10.1007/s11010-009-0373-1"
}

Laketa, D., Bjelobaba, I., Savić, J., Lavrnja, I., Stojiljković, M., Rakić, L.,& Nedeljković, N.. (2010). Biochemical characterization of soluble nucleotide pyrophosphatase/phosphodiesterase activity in rat serum. in Molecular and Cellular Biochemistry, 339(1-2), 99-106.
https://doi.org/10.1007/s11010-009-0373-1

Laketa D, Bjelobaba I, Savić J, Lavrnja I, Stojiljković M, Rakić L, Nedeljković N. Biochemical characterization of soluble nucleotide pyrophosphatase/phosphodiesterase activity in rat serum. in Molecular and Cellular Biochemistry. 2010;339(1-2):99-106.
doi:10.1007/s11010-009-0373-1 .

Laketa, Danijela, Bjelobaba, Ivana, Savić, Jasmina, Lavrnja, Irena, Stojiljković, Mirjana, Rakić, Ljubisav, Nedeljković, Nadežda, "Biochemical characterization of soluble nucleotide pyrophosphatase/phosphodiesterase activity in rat serum" in Molecular and Cellular Biochemistry, 339, no. 1-2 (2010):99-106,
https://doi.org/10.1007/s11010-009-0373-1 . .

TY  - JOUR
AU  - Nedeljković, Nadežda
AU  - Horvat, Anica
PY  - 2007
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3164
AB  - Membrane-bound ATPases, such as Na,K-ATPase and nucleotide triphospho-diphosphohydrolase (NTPDase), being one of the first targets of a toxic action are generally considered as good markers for estimating toxicity. A bioluminescence assay was applied for fast and sensitive evaluation of heavy metals effect on the rat brain synaptosomal membrane ATPase activity. The assay consists of ATP-consuming reaction catalyzed by synaptic plasma membrane ATPases coupled to the luminescent firefly luciferase reaction, which consumes residual ATP after the course of ATPase reaction. The bioluminescence ATPase assay was applied to study the effect of heavy and transitional metals (Cu2+, Pb2+, Cd2+, Hg2+) on rat brain ATPase activity after assay optimization. All metals applied inhibited synaptic membrane ATPase activity in a concentration dependent manner. The IC (50) values (Hg2+ LT Cu2+ LT Cd2+ LT Pb2+) obtained with the bioluminescence assay were highly correlated with those obtained by the spectrophotometric method. The fast bioluminescence ATPase assay with small sample and substrate requirements could be adjusted for high-throughput environmental and pharmacological screening.
T2  - Monatshefte Fur Chemie
T1  - One-step bioluminescence ATPase assay for the evaluation of neurotoxic effects of metal ions
VL  - 138
IS  - 3
SP  - 253
EP  - 260
DO  - 10.1007/s00706-007-0595-4
ER  - 

@article{
author = "Nedeljković, Nadežda and Horvat, Anica",
year = "2007",
abstract = "Membrane-bound ATPases, such as Na,K-ATPase and nucleotide triphospho-diphosphohydrolase (NTPDase), being one of the first targets of a toxic action are generally considered as good markers for estimating toxicity. A bioluminescence assay was applied for fast and sensitive evaluation of heavy metals effect on the rat brain synaptosomal membrane ATPase activity. The assay consists of ATP-consuming reaction catalyzed by synaptic plasma membrane ATPases coupled to the luminescent firefly luciferase reaction, which consumes residual ATP after the course of ATPase reaction. The bioluminescence ATPase assay was applied to study the effect of heavy and transitional metals (Cu2+, Pb2+, Cd2+, Hg2+) on rat brain ATPase activity after assay optimization. All metals applied inhibited synaptic membrane ATPase activity in a concentration dependent manner. The IC (50) values (Hg2+ LT Cu2+ LT Cd2+ LT Pb2+) obtained with the bioluminescence assay were highly correlated with those obtained by the spectrophotometric method. The fast bioluminescence ATPase assay with small sample and substrate requirements could be adjusted for high-throughput environmental and pharmacological screening.",
journal = "Monatshefte Fur Chemie",
title = "One-step bioluminescence ATPase assay for the evaluation of neurotoxic effects of metal ions",
volume = "138",
number = "3",
pages = "253-260",
doi = "10.1007/s00706-007-0595-4"
}

Nedeljković, N.,& Horvat, A.. (2007). One-step bioluminescence ATPase assay for the evaluation of neurotoxic effects of metal ions. in Monatshefte Fur Chemie, 138(3), 253-260.
https://doi.org/10.1007/s00706-007-0595-4

Nedeljković N, Horvat A. One-step bioluminescence ATPase assay for the evaluation of neurotoxic effects of metal ions. in Monatshefte Fur Chemie. 2007;138(3):253-260.
doi:10.1007/s00706-007-0595-4 .

Nedeljković, Nadežda, Horvat, Anica, "One-step bioluminescence ATPase assay for the evaluation of neurotoxic effects of metal ions" in Monatshefte Fur Chemie, 138, no. 3 (2007):253-260,
https://doi.org/10.1007/s00706-007-0595-4 . .