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  - 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  - 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  - Filipović, Dragana
AU  - Martinović, Jelena
AU  - Inta, Dragos
AU  - Bjelobaba, I.
AU  - Stojiljković, Mirjana
AU  - Gass, Peter
PY  - 2011
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4409
AB  - Mitochondria are central integrators and transducers of proapoptotic signals for neuronal apoptosis. The tumor suppressor protein p53 can trigger apoptosis independently of its transcriptional activity, through subcellular translocation of cytochrome c and caspase activation. To define better the proapoptotic role of p53 under various stress conditions, we investigated the protein levels of p53 and cytochrome c in mitochondrial and cytosolic fractions, as well as caspase-3 activation and apoptosis, in the prefrontal cortex and hippocampus of male Wistar rats subjected to acute, chronic, or combined stressors. Mitochondrial p53 can suppress the antioxidant enzyme MnSOD, so its activity was also determined. In the prefrontal cortex, but not in hippocampus, increased protein levels of p53 were found in mitochondria, leading to cytochrome c release into cytoplasm, activation of caspase-3, and apoptotic cell death following combined stressors. Decreased mitochondrial MnSOD activity following combined stressors in both brain structures indicated a state of oxidative stress. This suggests that chronic isolation stress compromises mitochondrial MnSOD activity in both the prefrontal cortex and the hippocampus but likely results in mitochondrial-triggered proapoptotic signaling mediated by a transcription-independent p53 mechanism only in the prefrontal cortex. Thus, our data demonstrate a tissue-specific (prefrontal cortex vs. hippocampus) response to applied stressors. (C) 2011 Wiley-Liss, Inc.
T2  - Journal of Neuroscience Research
T1  - Chronic Isolation Stress Predisposes the Frontal Cortex but Not the Hippocampus to the Potentially Detrimental Release of Cytochrome c From Mitochondria and the Activation of Caspase-3
VL  - 89
IS  - 9
SP  - 1461
EP  - 1470
DO  - 10.1002/jnr.22687
ER  - 

@article{
author = "Filipović, Dragana and Martinović, Jelena and Inta, Dragos and Bjelobaba, I. and Stojiljković, Mirjana and Gass, Peter",
year = "2011",
abstract = "Mitochondria are central integrators and transducers of proapoptotic signals for neuronal apoptosis. The tumor suppressor protein p53 can trigger apoptosis independently of its transcriptional activity, through subcellular translocation of cytochrome c and caspase activation. To define better the proapoptotic role of p53 under various stress conditions, we investigated the protein levels of p53 and cytochrome c in mitochondrial and cytosolic fractions, as well as caspase-3 activation and apoptosis, in the prefrontal cortex and hippocampus of male Wistar rats subjected to acute, chronic, or combined stressors. Mitochondrial p53 can suppress the antioxidant enzyme MnSOD, so its activity was also determined. In the prefrontal cortex, but not in hippocampus, increased protein levels of p53 were found in mitochondria, leading to cytochrome c release into cytoplasm, activation of caspase-3, and apoptotic cell death following combined stressors. Decreased mitochondrial MnSOD activity following combined stressors in both brain structures indicated a state of oxidative stress. This suggests that chronic isolation stress compromises mitochondrial MnSOD activity in both the prefrontal cortex and the hippocampus but likely results in mitochondrial-triggered proapoptotic signaling mediated by a transcription-independent p53 mechanism only in the prefrontal cortex. Thus, our data demonstrate a tissue-specific (prefrontal cortex vs. hippocampus) response to applied stressors. (C) 2011 Wiley-Liss, Inc.",
journal = "Journal of Neuroscience Research",
title = "Chronic Isolation Stress Predisposes the Frontal Cortex but Not the Hippocampus to the Potentially Detrimental Release of Cytochrome c From Mitochondria and the Activation of Caspase-3",
volume = "89",
number = "9",
pages = "1461-1470",
doi = "10.1002/jnr.22687"
}

Filipović, D., Martinović, J., Inta, D., Bjelobaba, I., Stojiljković, M.,& Gass, P.. (2011). Chronic Isolation Stress Predisposes the Frontal Cortex but Not the Hippocampus to the Potentially Detrimental Release of Cytochrome c From Mitochondria and the Activation of Caspase-3. in Journal of Neuroscience Research, 89(9), 1461-1470.
https://doi.org/10.1002/jnr.22687

Filipović D, Martinović J, Inta D, Bjelobaba I, Stojiljković M, Gass P. Chronic Isolation Stress Predisposes the Frontal Cortex but Not the Hippocampus to the Potentially Detrimental Release of Cytochrome c From Mitochondria and the Activation of Caspase-3. in Journal of Neuroscience Research. 2011;89(9):1461-1470.
doi:10.1002/jnr.22687 .

Filipović, Dragana, Martinović, Jelena, Inta, Dragos, Bjelobaba, I., Stojiljković, Mirjana, Gass, Peter, "Chronic Isolation Stress Predisposes the Frontal Cortex but Not the Hippocampus to the Potentially Detrimental Release of Cytochrome c From Mitochondria and the Activation of Caspase-3" in Journal of Neuroscience Research, 89, no. 9 (2011):1461-1470,
https://doi.org/10.1002/jnr.22687 . .

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 . .