%0 Journal Article %1 schwede2015rpcamps %A Schwede, F. %A Chepurny, O. G. %A Kaufholz, M. %A Bertinetti, D. %A Leech, C. A. %A Cabrera, O. %A Zhu, Y. %A Mei, F. %A Cheng, X. %A Manning Fox, J. E. %A MacDonald, P. A. %A Genieser, H. %A Herberg, F. W. %A Holz, G. G. %D 2015 %J Molecular Endocrinology %K herberg myown %N 7 %P 988-1005 %R 10.1210/me.2014-1330 %T Rp-cAMPS Prodrugs Reveal the cAMP Dependence of First-Phase Glucose-Stimulated Insulin Secretion %U http://www.ncbi.nlm.nih.gov/pubmed/?term=Rp-cAMPS+Prodrugs+Reveal+the+cAMP %V 29 %X Adenosine 3',5'-cyclic monophosphate (cAMP) elevating agents such as the incretin hormone glucagon-like peptide-1 (GLP-1) potentiate glucose-stimulated insulin secretion (GSIS) from pancreatic beta cells. However, a debate has existed since the 1970's concerning whether or not cAMP signaling is essential for glucose alone to stimulate insulin secretion. Here we report that the first-phase kinetic component of GSIS is cAMP-dependent, as revealed through the use of a novel highly membrane permeable para-acetoxybenzyl (pAB) ester prodrug that is a bioactivatable derivative of the cAMP antagonist Rp-cAMPS. In dynamic perifusion assays of human or rat islets, a step-wise increase of glucose concentration leads to biphasic insulin secretion, and under these conditions Rp-8-Br-cAMPS-pAB inhibits first-phase GSIS by up to 80%. Surprisingly, second-phase GSIS is inhibited to a much smaller extent (< 20%). Using luciferase, FRET, and BRET assays performed in living cells, we validate that Rp-8-Br-cAMPS-pAB does in fact block cAMP-dependent protein kinase (PKA) activation. Novel actions of Rp-8-Br-cAMPS-pAB to block cAMP sensor Epac1 and Epac2 activation are also validated using genetically encoded Epac biosensors, and are independently confirmed in an in vitro Rap1 activation assay using Rp-cAMPS and Rp-8-Br-cAMPS. Thus, in addition to revealing the cAMP-dependence of first-phase GSIS from human and rat islets, these findings establish a pAB-based chemistry for the synthesis of highly membrane permeable prodrug derivatives of Rp-cAMPS that act with micromolar or even nanomolar potency to inhibit cAMP signaling in living cells.

@article{schwede2015rpcamps, abstract = {Adenosine 3',5'-cyclic monophosphate (cAMP) elevating agents such as the incretin hormone glucagon-like peptide-1 (GLP-1) potentiate glucose-stimulated insulin secretion (GSIS) from pancreatic beta cells. However, a debate has existed since the 1970's concerning whether or not cAMP signaling is essential for glucose alone to stimulate insulin secretion. Here we report that the first-phase kinetic component of GSIS is cAMP-dependent, as revealed through the use of a novel highly membrane permeable para-acetoxybenzyl (pAB) ester prodrug that is a bioactivatable derivative of the cAMP antagonist Rp-cAMPS. In dynamic perifusion assays of human or rat islets, a step-wise increase of glucose concentration leads to biphasic insulin secretion, and under these conditions Rp-8-Br-cAMPS-pAB inhibits first-phase GSIS by up to 80%. Surprisingly, second-phase GSIS is inhibited to a much smaller extent (< 20%). Using luciferase, FRET, and BRET assays performed in living cells, we validate that Rp-8-Br-cAMPS-pAB does in fact block cAMP-dependent protein kinase (PKA) activation. Novel actions of Rp-8-Br-cAMPS-pAB to block cAMP sensor Epac1 and Epac2 activation are also validated using genetically encoded Epac biosensors, and are independently confirmed in an in vitro Rap1 activation assay using Rp-cAMPS and Rp-8-Br-cAMPS. Thus, in addition to revealing the cAMP-dependence of first-phase GSIS from human and rat islets, these findings establish a pAB-based chemistry for the synthesis of highly membrane permeable prodrug derivatives of Rp-cAMPS that act with micromolar or even nanomolar potency to inhibit cAMP signaling in living cells.}, added-at = {2015-05-11T09:10:39.000+0200}, author = {Schwede, F. and Chepurny, O. G. and Kaufholz, M. and Bertinetti, D. and Leech, C. A. and Cabrera, O. and Zhu, Y. and Mei, F. and Cheng, X. and Manning Fox, J. E. and MacDonald, P. A. and Genieser, H. and Herberg, F. W. and Holz, G. G.}, biburl = {https://www.bibsonomy.org/bibtex/22782df024b6ad35fd9fc13af11b96419/biochemie}, doi = {10.1210/me.2014-1330}, interhash = {ba10f9290f23537278217e229aa92f67}, intrahash = {2782df024b6ad35fd9fc13af11b96419}, journal = {Molecular Endocrinology}, keywords = {herberg myown}, number = 7, pages = {988-1005}, pmid = {26061564}, timestamp = {2015-07-27T15:52:08.000+0200}, title = {Rp-cAMPS Prodrugs Reveal the cAMP Dependence of First-Phase Glucose-Stimulated Insulin Secretion}, url = {http://www.ncbi.nlm.nih.gov/pubmed/?term=Rp-cAMPS+Prodrugs+Reveal+the+cAMP}, volume = 29, year = 2015 }