TY  - JOUR
AU  - Stuenaes, Jorid T.
AU  - Bolling, Astrid
AU  - Ingvaldsen, Ada
AU  - Rommundstad, Camilla
AU  - Sudar, Emina
AU  - Lin, Fang-Chin
AU  - Lai, Yu-Chiang
AU  - Jensen, Jorgen
PY  - 2010
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3977
AB  - Background and purpose: Genetic approaches have documented protein kinase B (PKB) as a pivotal regulator of heart function. Insulin strongly activates PKB, whereas adrenaline is not considered a major physiological regulator of PKB in heart. In skeletal muscles, however, adrenaline potentiates insulin-stimulated PKB activation without having effect in the absence of insulin. The purpose of the present study was to investigate the interaction between insulin and beta-adrenergic stimulation in regulation of PKB phosphorylation. Experimental approach: Cardiomyocytes were isolated from adult rats by collagenase, and incubated with insulin, isoprenaline, and other compounds. Protein phosphorylation was evaluated by Western blot and phospho-specific antibodies. Key results: Isoprenaline increased insulin-stimulated PKB Ser473 and Thr308 phosphorylation more than threefold in cardiomyocytes. Isoprenaline alone did not increase PKB phosphorylation. Isoprenaline also increased insulin-stimulated GSK-3 beta Ser9 phosphorylation approximately twofold, supporting that PKB phosphorylation increased kinase activity. Dobutamine (beta(1)-agonist) increased insulin-stimulated PKB phosphorylation as effectively as isoprenaline (more than threefold), whereas salbutamol (beta(2)-agonist) only potentiated insulin-stimulated PKB phosphorylation by approximately 80%. Dobutamine, but not salbutamol, increased phospholamban Ser16 phosphorylation and glycogen phosphorylase activation (PKA-mediated effects). Furthermore, the cAMP analogue that activates PKA (dibutyryl-cAMP and N6-benzoyl-cAMP) increased insulin-stimulated PKB phosphorylation by more than threefold without effect alone. The Epac-specific activator 8-(4-chlorophenylthio)-2-O-methyl-cAMP (007) increased insulin-stimulated PKB phosphorylation by approximately 50%. Db-cAMP and N6-benzoyl-cAMP, but not 007, increased phospholamban Ser16 phosphorylation. Conclusions and implications: beta-adrenoceptors are strong regulators of PKB phosphorylation via cAMP and PKA when insulin is present. We hypothesize that PKB mediates important signalling in the heart during beta-adrenergic receptors stimulation.
T2  - British Journal of Pharmacology
T1  - beta-Adrenoceptor stimulation potentiates insulin-stimulated PKB phosphorylation in rat cardiomyocytes via cAMP and PKA
VL  - 160
IS  - 1
SP  - 116
EP  - 129
DO  - 10.1111/j.1476-5381.2010.00677.x
ER  - 

@article{
author = "Stuenaes, Jorid T. and Bolling, Astrid and Ingvaldsen, Ada and Rommundstad, Camilla and Sudar, Emina and Lin, Fang-Chin and Lai, Yu-Chiang and Jensen, Jorgen",
year = "2010",
abstract = "Background and purpose: Genetic approaches have documented protein kinase B (PKB) as a pivotal regulator of heart function. Insulin strongly activates PKB, whereas adrenaline is not considered a major physiological regulator of PKB in heart. In skeletal muscles, however, adrenaline potentiates insulin-stimulated PKB activation without having effect in the absence of insulin. The purpose of the present study was to investigate the interaction between insulin and beta-adrenergic stimulation in regulation of PKB phosphorylation. Experimental approach: Cardiomyocytes were isolated from adult rats by collagenase, and incubated with insulin, isoprenaline, and other compounds. Protein phosphorylation was evaluated by Western blot and phospho-specific antibodies. Key results: Isoprenaline increased insulin-stimulated PKB Ser473 and Thr308 phosphorylation more than threefold in cardiomyocytes. Isoprenaline alone did not increase PKB phosphorylation. Isoprenaline also increased insulin-stimulated GSK-3 beta Ser9 phosphorylation approximately twofold, supporting that PKB phosphorylation increased kinase activity. Dobutamine (beta(1)-agonist) increased insulin-stimulated PKB phosphorylation as effectively as isoprenaline (more than threefold), whereas salbutamol (beta(2)-agonist) only potentiated insulin-stimulated PKB phosphorylation by approximately 80%. Dobutamine, but not salbutamol, increased phospholamban Ser16 phosphorylation and glycogen phosphorylase activation (PKA-mediated effects). Furthermore, the cAMP analogue that activates PKA (dibutyryl-cAMP and N6-benzoyl-cAMP) increased insulin-stimulated PKB phosphorylation by more than threefold without effect alone. The Epac-specific activator 8-(4-chlorophenylthio)-2-O-methyl-cAMP (007) increased insulin-stimulated PKB phosphorylation by approximately 50%. Db-cAMP and N6-benzoyl-cAMP, but not 007, increased phospholamban Ser16 phosphorylation. Conclusions and implications: beta-adrenoceptors are strong regulators of PKB phosphorylation via cAMP and PKA when insulin is present. We hypothesize that PKB mediates important signalling in the heart during beta-adrenergic receptors stimulation.",
journal = "British Journal of Pharmacology",
title = "beta-Adrenoceptor stimulation potentiates insulin-stimulated PKB phosphorylation in rat cardiomyocytes via cAMP and PKA",
volume = "160",
number = "1",
pages = "116-129",
doi = "10.1111/j.1476-5381.2010.00677.x"
}

Stuenaes, J. T., Bolling, A., Ingvaldsen, A., Rommundstad, C., Sudar, E., Lin, F., Lai, Y.,& Jensen, J.. (2010). beta-Adrenoceptor stimulation potentiates insulin-stimulated PKB phosphorylation in rat cardiomyocytes via cAMP and PKA. in British Journal of Pharmacology, 160(1), 116-129.
https://doi.org/10.1111/j.1476-5381.2010.00677.x

Stuenaes JT, Bolling A, Ingvaldsen A, Rommundstad C, Sudar E, Lin F, Lai Y, Jensen J. beta-Adrenoceptor stimulation potentiates insulin-stimulated PKB phosphorylation in rat cardiomyocytes via cAMP and PKA. in British Journal of Pharmacology. 2010;160(1):116-129.
doi:10.1111/j.1476-5381.2010.00677.x .

Stuenaes, Jorid T., Bolling, Astrid, Ingvaldsen, Ada, Rommundstad, Camilla, Sudar, Emina, Lin, Fang-Chin, Lai, Yu-Chiang, Jensen, Jorgen, "beta-Adrenoceptor stimulation potentiates insulin-stimulated PKB phosphorylation in rat cardiomyocytes via cAMP and PKA" in British Journal of Pharmacology, 160, no. 1 (2010):116-129,
https://doi.org/10.1111/j.1476-5381.2010.00677.x . .

TY  - JOUR
AU  - Velebit, Jelena
AU  - Kovacic, Petra Brina
AU  - Prebil, Mateja
AU  - Chowdhury, Helena H.
AU  - Grilc, Sonja
AU  - Kreft, Marko
AU  - Jensen, Jorgen
AU  - Isenović, Esma R.
AU  - Zorec, Robert
PY  - 2008
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3537
AB  - In this study we hypothesized that rosiglitazone, an antidiabetic high-affinity agonist for the peroxisome proliferator-activated receptor gamma, affects the plasma membrane (PM) turnover in single 3T3-L1 adipocytes. To study the PM turnover, the patch-clamp electrophysiological method was used to measure changes in membrane capacitance (C-m), a parameter linearly related to the PM area. Microscopy results show that the presence of rosiglitazone in the differentiating medium significantly increased the differentiation of 3T3-L1 adipocytes in cell culture, based on oil red O-stained area (11.4 +/- 1.2%) vs. controls (3.1 +/- 0.5%). Moreover, rosiglitazone treatment significantly reduced the size of single 3T3-L1 adipocytes; their average radius of 21.1 +/- 1.1 mu m in controls was reduced to 17.5 +/- 0.5 mu m in rosiglitazone-treated cells. Consistent with this, insulin application increased the rate of C-m increase to 2.34 +/- 0.10%/min, which was significantly different from controls (0.12 +/- 0.08%/min). However, pretreatment of cells with rosiglitazone prior to the treatment with insulin resulted in an attenuated rate of C (m) increase. These data support the involvement of insulin in the modulation of membrane area and show that treatment by rosiglitazone reduced the insulin-mediated membrane area increase in 3T3-L1 adipocytes.
T2  - Journal of Membrane Biology
T1  - Rosiglitazone modulates insulin-induced plasma membrane area changes in single 3T3-L1 adipocytes
VL  - 223
IS  - 3
SP  - 141
EP  - 149
DO  - 10.1007/s00232-008-9120-x
ER  - 

@article{
author = "Velebit, Jelena and Kovacic, Petra Brina and Prebil, Mateja and Chowdhury, Helena H. and Grilc, Sonja and Kreft, Marko and Jensen, Jorgen and Isenović, Esma R. and Zorec, Robert",
year = "2008",
abstract = "In this study we hypothesized that rosiglitazone, an antidiabetic high-affinity agonist for the peroxisome proliferator-activated receptor gamma, affects the plasma membrane (PM) turnover in single 3T3-L1 adipocytes. To study the PM turnover, the patch-clamp electrophysiological method was used to measure changes in membrane capacitance (C-m), a parameter linearly related to the PM area. Microscopy results show that the presence of rosiglitazone in the differentiating medium significantly increased the differentiation of 3T3-L1 adipocytes in cell culture, based on oil red O-stained area (11.4 +/- 1.2%) vs. controls (3.1 +/- 0.5%). Moreover, rosiglitazone treatment significantly reduced the size of single 3T3-L1 adipocytes; their average radius of 21.1 +/- 1.1 mu m in controls was reduced to 17.5 +/- 0.5 mu m in rosiglitazone-treated cells. Consistent with this, insulin application increased the rate of C-m increase to 2.34 +/- 0.10%/min, which was significantly different from controls (0.12 +/- 0.08%/min). However, pretreatment of cells with rosiglitazone prior to the treatment with insulin resulted in an attenuated rate of C (m) increase. These data support the involvement of insulin in the modulation of membrane area and show that treatment by rosiglitazone reduced the insulin-mediated membrane area increase in 3T3-L1 adipocytes.",
journal = "Journal of Membrane Biology",
title = "Rosiglitazone modulates insulin-induced plasma membrane area changes in single 3T3-L1 adipocytes",
volume = "223",
number = "3",
pages = "141-149",
doi = "10.1007/s00232-008-9120-x"
}

Velebit, J., Kovacic, P. B., Prebil, M., Chowdhury, H. H., Grilc, S., Kreft, M., Jensen, J., Isenović, E. R.,& Zorec, R.. (2008). Rosiglitazone modulates insulin-induced plasma membrane area changes in single 3T3-L1 adipocytes. in Journal of Membrane Biology, 223(3), 141-149.
https://doi.org/10.1007/s00232-008-9120-x

Velebit J, Kovacic PB, Prebil M, Chowdhury HH, Grilc S, Kreft M, Jensen J, Isenović ER, Zorec R. Rosiglitazone modulates insulin-induced plasma membrane area changes in single 3T3-L1 adipocytes. in Journal of Membrane Biology. 2008;223(3):141-149.
doi:10.1007/s00232-008-9120-x .

Velebit, Jelena, Kovacic, Petra Brina, Prebil, Mateja, Chowdhury, Helena H., Grilc, Sonja, Kreft, Marko, Jensen, Jorgen, Isenović, Esma R., Zorec, Robert, "Rosiglitazone modulates insulin-induced plasma membrane area changes in single 3T3-L1 adipocytes" in Journal of Membrane Biology, 223, no. 3 (2008):141-149,
https://doi.org/10.1007/s00232-008-9120-x . .