Calmodulin-dependent cyclic nucleotide phosphodiesterase in an experimental rat model of cardiac ischemia–reperfusion

2002 ◽  
Vol 80 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Rakesh Kakkar ◽  
Dallas P Seitz ◽  
Rani Kanthan ◽  
Raju VS Rajala ◽  
Jasim M Radhi ◽  
...  
Keyword(s):  
Cyclic Nucleotide ◽  
Ischemia Reperfusion ◽  
Progressive Increase ◽  
Cyclic Nucleotide Phosphodiesterase ◽  
Calpain Inhibitor ◽  
Rat Myocardium ◽  
Hypoxic Injury ◽  
Heart Ischemia ◽  
Immunohistochemical Studies

In the present study, we investigated the activity and expression of calmodulin-dependent cyclic nucleotide phosphodiesterase (CaMPDE) and the effects of calpains in rat heart after ischemia and reperfusion. Immunohistochemical studies indicated that CaMPDE in normal heart is localized in myocardial cells. Rat ischemic heart showed a decrease in CaMPDE activity in the presence of Ca2+ and calmodulin; however, in ischemic–reperfusion tissue a progressive increase in Ca2+ and calmodulin-independent cyclic nucleotide phosphodiesterase (CaM-independent PDE) activity was observed. Perfusion of hearts with cell-permeable calpain inhibitor suppressed the increase of Ca2+ and CaM-independent PDE activity. Protein expression of CaMPDE was uneffected by hypoxic injury to rat myocardium. The purified heart CaMPDE was proteolyzed by calpains into a 45 kDa immunoreactive fragment in vitro. Based on these results, we propose that hypoxic injury to rat myocardium results in the generation of CaM-independent PDE by calpain mediated proteolysis, allowing the maintenance of cAMP concentrations within the physiological range.Key words: phosphodiesterase, calmodulin, calpains, heart, ischemia, reperfusion.

scholarly journals Phosphorylation by casein kinase II alters the biological activity of calmodulin

1992 ◽  
Vol 283 (1) ◽  
pp. 21-24 ◽  
Author(s):  
D B Sacks ◽  
H W Davis ◽  
J P Williams ◽  
E L Sheehan ◽  
J G N Garcia ◽  
...  
Keyword(s):  
Light Chain ◽  
Cyclic Nucleotide ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Cyclic Nucleotide Phosphodiesterase ◽  
Maximal Velocity ◽  
Intact Cells

Calmodulin is the major intracellular Ca(2+)-binding protein, providing Ca(2+)-dependent regulation of numerous intracellular enzymes. The phosphorylation of calmodulin may provide an additional mechanism for modulating its function as a signal transducer. Phosphocalmodulin has been identified in tissues and cells, and calmodulin is phosphorylated both in vitro and in intact cells by various enzymes. Phosphorylation of calmodulin on serine/threonine residues by casein kinase II decreases its ability to activate both myosin-light-chain kinase and cyclic nucleotide phosphodiesterase. For myosin-light-chain kinase the primary effect is an inhibition of the Vmax. of the reaction, with no apparent change in the concentration at which half-maximal velocity is attained (K0.5) for either Ca2+ or calmodulin. In contrast, for phosphodiesterase, phosphorylation of calmodulin significantly increases the K0.5 for calmodulin without noticeably altering the Vmax. or the K0.5 for Ca2+. The higher the stoichiometry of phosphorylation of calmodulin, the greater the inhibition of calmodulin-stimulated activity for both enzymes. Therefore the phosphorylation of calmodulin by casein kinase II appears to provide a Ca(2+)-independent mechanism whereby calmodulin regulates at least two important target enzymes, myosin-light-chain kinase and cyclic nucleotide phosphodiesterase.

Abstract 82: Regulation Of Frataxin By HIF-1 In The Ischemic Diabetic Heart

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Raj H Amin ◽  
Abdullah AlAsmari ◽  
Gayani Nanayakkari ◽  
John Quindry ◽  
Shavanthi Mouli ◽  
...  
Keyword(s):  
Heart Failure ◽  
Insulin Signalling ◽  
Ischemia Reperfusion ◽  
Mitochondrial Protein ◽  
Hypoxia Inducible Factor ◽  
Diabetic Heart ◽  
Diabetic Patients ◽  
Hypoxic Injury ◽  
Infarction Size

Background: Diabetes is at epidemic proportions, with the major form of fatality due to congestive heart failure triggered by myocardial infarction (MI). The impaired insulin signalling in the diabetic heart leads to myocardial energy dysregulation that compromises the cardioprotective mechanism against ischemic injury. Therefore understanding how mitochondrial energetics is altered in the diabetic ischemic heart would greatly advance the knowledge base for improving outcomes from heart failure in diabetic patients. Methods/Findings: We observed that db/db mice (leptin deficient, type 2 diabetic mice) have increased infarction size (>30%) compared to wild type mice after ischemia/reperfusion (IR) injury by TTC stain. We also found that activity of Hypoxia inducible factor-1 (HIF1) is involved in the cardioprotective response to ischemia, is impaired in db/db hearts. HIF1 is known to transcriptionally regulate genes involved in myocardial energetics. We recently found that HIF1 transcriptionally regulates the mitochondrial protein frataxin (Fxn) in cardiomyocytes as determined by luciferase assays (>3 fold). In vitro studies indicate that hypoxic conditions increase Fxn protein expression in cardiomyocytes as determined by western analysis (2 fold). Fxn plays an important role in the Fe-S cluster biogenesis required for aconitase, succinate dehydrogenase and complexes in the mitochondria. Interestingly, we observed decreased expression of Fxn in the ischemic diabetic heart. Conclusion: we postulate that attenuated HIF1-Fxn signalling in ischemic diabetic heart leads to abnormally enlarged infarction size in response to IR. The decline in HIF-1 activity in response to hypoxia was further validated in cardiomyocytes cultured in high glucose media. The significance for Fxn against hypoxic injury was confirmed by utilizing overexpressed Fxn cardiomyocytes via MTT, ATP and aconitase activity assays. Current and future work: currently we are attempting to identify the HIF response element (HRE) in Fxn promoter to further validate the transcriptional activity of HIF1. In addition, we are completing the IR surgeries on HIF1 KO mice to address the cardioprotective nature of HIF1-Fxn signalling against MI.

EFFECTS OF SILDENAFIL ON THE RELAXATION OF HUMAN CORPUS CAVERNOSUM TISSUE IN VITRO AND ON THE ACTIVITIES OF CYCLIC NUCLEOTIDE PHOSPHODIESTERASE ISOZYMES

1998 ◽  
Vol 159 (6) ◽  
pp. 2164-2171 ◽  
Author(s):  
STEPHEN A. BALLARD ◽  
CLIVE J. GINGELL ◽  
KIM TANG ◽  
LEIGH A. TURNER ◽  
MARY E. PRICE ◽  
...  
Keyword(s):  
Cyclic Nucleotide ◽  
Corpus Cavernosum ◽  
Cyclic Nucleotide Phosphodiesterase

scholarly journals KS-505a, an isoform-selective inhibitor of calmodulin-dependent cyclic nucleotide phosphodiesterase

1996 ◽  
Vol 316 (1) ◽  
pp. 311-316 ◽  
Author(s):  
Michio ICHIMURA ◽  
Rika EIKI ◽  
Keiko OSAWA ◽  
Satoshi NAKANISHI ◽  
Hiroshi KASE
Keyword(s):  
Cyclic Nucleotide ◽  
Hippocampal Slices ◽  
Selective Inhibitor ◽  
Binding Domain ◽  
Cyclic Nucleotide Phosphodiesterase ◽  
Intracellular Camp ◽  
Camp Concentration ◽  
Striatal Slices

The effects of KS-505a, a novel microbial metabolite, on the activity of calmodulin-dependent cyclic nucleotide phosphodiesterase (CaM-PDE) were investigated. (1) KS-505a potently inhibited the purified 61 kDa isoenzyme of CaM-PDE from bovine brain and required much higher doses to inhibit the purified 59 kDa isoenzyme of CaM-PDE from bovine heart. The inhibition of both isoenzymes was observed only in the presence of calcium-activated calmodulin (Ca2+/CaM). The IC50 values for the 61 and 59 kDa isoenzymes were 0.17 and 13 μM respectively with 20 μM cAMP as a substrate. (2) Kinetic analysis indicated that the inhibitory mode of KS-505a for the 61 kDa isoenzyme was competitive with respect to Ca2+/CaM; the Ki for KS-505a was 0.089 μM. The inhibition was not competitive with respect to the substrates cAMP or cGMP. (3) KS-505a did not interfere with the interaction between Ca2+/CaM and n-phenyl-1-naphthylamine, a hydrophobic fluorescent probe, nor was it adsorbed to CaM-conjugated gels in the presence of Ca2+, thereby indicating that KS-505a does not bind to Ca2+/CaM. (4) Trypsin-activated 61 kDa isoenzyme, which lacked the Ca2+/CaM-binding domain, was not inhibited by KS-505a at less than micromolar concentrations. Taken together, these results suggest that KS-505a apparently bound to a site in the Ca2+/CaM-binding domain of the 61 kDa isoenzyme and selectively inhibited Ca2+/CaM-activated 61 kDa isoenzyme activity. (5) In rat hippocampal slices, KS-505a at 10 μM increased the intracellular cAMP concentration to approximately three times the basal level, whereas in rat striatal slices it had no effect on the cAMP concentration at concentrations of 1.0–10 μM, suggesting that each CaM-PDE isoenzyme functions differentially in these regions. These results demonstrate that KS-505a is a highly potent selective inhibitor both in vitro and in vivo and distinguishes between subfamily members within the CaM-PDE family.

scholarly journals Cyclic nucleotide phosphodiesterase 1C contributes to abdominal aortic aneurysm

2021 ◽  
Vol 118 (31) ◽  
pp. e2107898118
Author(s):  
Chongyang Zhang ◽  
Hongmei Zhao ◽  
Yujun Cai ◽  
Jian Xiong ◽  
Amy Mohan ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Cyclic Nucleotide ◽  
Aortic Aneurysms ◽  
Cyclic Nucleotide Phosphodiesterase ◽  
Causative Role ◽  
Abdominal Aortic

Abdominal aortic aneurysm (AAA) is characterized by aorta dilation due to wall degeneration, which mostly occurs in elderly males. Vascular aging is implicated in degenerative vascular pathologies, including AAA. Cyclic nucleotide phosphodiesterases, by hydrolyzing cyclic nucleotides, play critical roles in regulating vascular structure remodeling and function. Cyclic nucleotide phosphodiesterase 1C (PDE1C) expression is induced in dedifferentiated and aging vascular smooth muscle cells (SMCs), while little is known about the role of PDE1C in aneurysm. We observed that PDE1C was not expressed in normal aorta but highly induced in SMC-like cells in human and murine AAA. In mouse AAA models induced by Angiotensin II or periaortic elastase, PDE1C deficiency significantly decreased AAA incidence, aortic dilation, and elastin degradation, which supported a causative role of PDE1C in AAA development in vivo. Pharmacological inhibition of PDE1C also significantly suppressed preestablished AAA. We showed that PDE1C depletion antagonized SMC senescence in vitro and/or in vivo, as assessed by multiple senescence biomarkers, including senescence-associated β-galactosidase activity, γ-H2AX foci number, and p21 protein level. Interestingly, the role of PDE1C in SMC senescence in vitro and in vivo was dependent on Sirtuin 1 (SIRT1). Mechanistic studies further showed that cAMP derived from PDE1C inhibition stimulated SIRT1 activation, likely through a direct interaction between cAMP and SIRT1, which leads to subsequent up-regulation of SIRT1 expression. Our findings provide evidence that PDE1C elevation links SMC senescence to AAA development in both experimental animal models and human AAA, suggesting therapeutical significance of PDE1C as a potential target against aortic aneurysms.

Porcine detrusor cyclic nucleotide phosphodiesterase isoenzymes: Characterization and functional effects of various phosphodiesterase inhibitors in vitro

Urology ◽  
1995 ◽  
Vol 45 (5) ◽  
pp. 893-901 ◽  
Author(s):  
Michael C. Truss ◽  
Rüdiger Hess ◽  
Stefan Ückert ◽  
Wolf-Georg Forssmann ◽  
Christian G. Stief ◽  
...  
Keyword(s):  
Cyclic Nucleotide ◽  
Phosphodiesterase Inhibitors ◽  
Cyclic Nucleotide Phosphodiesterase ◽  
Phosphodiesterase Isoenzymes

Regional differentiation in the rat aorta: effects of cyclooxygenase inhibitors

1997 ◽  
Vol 273 (3) ◽  
pp. H1478-H1483 ◽  
Author(s):  
D. Schachter ◽  
J. C. Sang
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Cyclic Nucleotide ◽  
Rat Aorta ◽  
Cyclic Nucleotide Phosphodiesterase ◽  
Cyclooxygenase Inhibitors ◽  
Regional Differentiation ◽  
Phosphodiesterase Activity ◽  
Dynamic Regulation

Rat aortic endothelium is differentiated regionally for signaling the underlying smooth muscle via nitric oxide to increase the level of guanosine 3',5'-cyclic monophosphate (cGMP) [R.E. Abbott and D. Schachter. Am. J. Physiol. 266 (Heart Circ. Physiol. 35): H2287-H2295, 1994]. Maximal activity is just distal to the aortic arch, i.e., in the "windkessel" region, and diminishes peripherally. This report describes the same pattern of endothelial differentiation for a second signal arising from the cyclooxygenase arm of the eicosanoid pathway. Treatment of sequential segments of rat aorta in vitro with indomethacin (50 microM) or acetylsalicylate (100 microM) increased the cGMP content selectively in aortic segments prepared from the windkessel region. The indomethacin effect was eliminated by denuding the endothelium or by inhibiting cyclic nucleotide phosphodiesterase activity. Prostaglandin H2 was identified as a cyclooxygenase product involved in this signal pathway because treatment with the compound decreased cGMP levels, and this effect was eliminated by inhibiting cyclic nucleotide phosphodiesterase activity. Endothelial regulation of smooth muscle cGMP via nitric oxide and cyclooxygenase pathways supports the concept of dynamic regulation of aortic wall properties in the windkessel region.

scholarly journals Cyclic nucleotide phosphodiesterase 3A1 protects the heart against ischemia-reperfusion injury

2013 ◽  
Vol 64 ◽  
pp. 11-19 ◽  
Author(s):  
Masayoshi Oikawa ◽  
Meiping Wu ◽  
Soyeon Lim ◽  
Walter E. Knight ◽  
Clint L. Miller ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Cyclic Nucleotide ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cyclic Nucleotide Phosphodiesterase
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