scholarly journals KLF15 Regulates Oxidative Stress Response in Cardiomyocytes through NAD+

Metabolites ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 620
Author(s):  
Le Li ◽  
Weiyi Xu ◽  
Lilei Zhang
Keyword(s):  
Oxidative Stress ◽  
Ventricular Myocytes ◽  
Cardiac Metabolism ◽  
Neonatal Rat ◽  
Oxygen Species ◽  
Oxidative Stresses ◽  
Neonatal Rat Ventricular Myocytes ◽  
Rate Limiting ◽  
Defective Clearance

KLF15 has recently emerged as a central regulator of metabolism. Although its connection to oxidative stress has been suspected, there has not been any study to date that directly demonstrates the molecular link. In this study, we sought to determine the role of KLF15 in cardiac oxidative stress. We found that KLF15 deficiency in the heart is associated with increased oxidative stress. Acute deficiency of KLF15 in neonatal rat ventricular myocytes (NRVMs) leads to the defective clearance of reactive oxygen species (ROS) and an exaggerated cell death following a variety of oxidative stresses. Mechanistically, we found that KLF15 deficiency leads to reduced amounts of the rate-limiting NAD+ salvage enzyme NAMPT and to NAD+ deficiency. The resultant SIRT3-dependent hyperacetylation and the inactivation of mitochondrial antioxidants can be rescued by MnSOD mimetics or NAD+ precursors. Collectively, these findings suggest that KLF15 regulates cardiac ROS clearance through the regulation of NAD+ levels. Our findings establish KLF15 as a central coordinator of cardiac metabolism and ROS clearance.

Cytochrome P-450 metabolites in endothelin-stimulated cardiac hormone secretion

2004 ◽  
Vol 286 (5) ◽  
pp. R888-R893 ◽  
Author(s):  
Sook Jeong Lee ◽  
Carol S. Landon ◽  
Stanley J. Nazian ◽  
John R. Dietz
Keyword(s):  
Protein Kinase ◽  
Inhibitory Action ◽  
Ventricular Myocytes ◽  
Hormone Secretion ◽  
Neonatal Rat ◽  
Kinase C ◽  
Neonatal Rat Ventricular Myocytes ◽  
Cytochrome P 450 ◽  
Kinase A

We examined the role of cytochrome P-450-arachidonate (CYP450-AA) metabolites in endothelin-1 (ET-1)-stimulated atrial natriuretic peptide (ANP) and pro-ANP-(1-30) secretion from the heart. 17-Octadecynoic acid (17-ODYA, 10-5 M) significantly inhibited ANP secretion stimulated by ET-1 (10-8 M) in the isolated perfused rat atria and inhibited pro-ANP-(1-30) secretion stimulated by ET-1 (10-8 M) or 20-hydroxyeicosatetraenoic acid in cultured neonatal rat ventricular myocytes (NRVM). In NRVM, 17-ODYA significantly ( P < 0.05) increased secretion of cAMP but had no significant effect on the secretion of cGMP from NRVM. Staurosporine, an inhibitor of protein kinase C, completely blocked the inhibitory action of 17-ODYA, whereas a protein kinase A inhibitor, H-89 (5 × 10-5 M), did not significantly attenuate the effects of 17-ODYA. The results show that the inhibitory action of 17-ODYA on ET-1-augmented ANP secretion is mediated through cAMP and suggest that CYP450-AA may play an important role in ET-1-induced cardiac hormone secretion.

scholarly journals Nitric oxide-induced cardioprotection in cultured rat ventricular myocytes

2000 ◽  
Vol 278 (4) ◽  
pp. H1211-H1217 ◽  
Author(s):  
Roby D. Rakhit ◽  
Richard J. Edwards ◽  
James W. Mockridge ◽  
Anwar R. Baydoun ◽  
Amanda W. Wyatt ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Ventricular Myocytes ◽  
Culture Conditions ◽  
Neonatal Rat ◽  
No Donor ◽  
Rat Ventricular Myocytes ◽  
Kinase C ◽  
Neonatal Rat Ventricular Myocytes ◽  
Oxide Synthase

The aim of this study was to investigate the role of nitric oxide (NO) in a cellular model of early preconditioning (PC) in cultured neonatal rat ventricular myocytes. Cardiomyocytes “preconditioned” with 90 min of stimulated ischemia (SI) followed by 30 min reoxygenation in normal culture conditions were protected against subsequent 6 h of SI. PC was blocked by N G-monomethyl-l-arginine monoacetate but not by dexamethasone pretreatment. Inducible nitric oxide synthase (NOS) protein expression was not detected during PC ischemia. Pretreatment (90 min) with the NO donor S-nitroso- N-acetyl-l,l-penicillamine (SNAP) mimicked PC, resulting in significant protection. SNAP-triggered protection was completely abolished by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) but was unaffected by chelerythrine or the presence of glibenclamide and 5-hydroxydecanoate. With the use of RIA, SNAP treatment increased cGMP levels, which were blocked by ODQ. Hence, NO is implicated as a trigger in this model of early PC via activation of a constitutive NOS isoform. After exposure to SNAP, the mechanism of cardioprotection is cGMP dependent but independent of protein kinase C or ATP-sensitive K+ channels. This differs from the proposed mechanism of NO-induced cardioprotection in late PC.

scholarly journals Matrix metalloproteinase-2 in oncostatin M-induced sarcomere degeneration in cardiomyocytes

2016 ◽  
Vol 311 (1) ◽  
pp. H183-H189 ◽  
Author(s):  
Xiaohu Fan ◽  
Bryan G. Hughes ◽  
Mohammad A. M. Ali ◽  
Brandon Y. H. Chan ◽  
Katherine Launier ◽  
...  
Keyword(s):  
Matrix Metalloproteinase ◽  
Troponin I ◽  
Ventricular Myocytes ◽  
Oncostatin M ◽  
Neonatal Rat ◽  
Matrix Metalloproteinase 2 ◽  
Mmp Inhibitor ◽  
Confocal Immunofluorescence ◽  
Neonatal Rat Ventricular Myocytes

Cardiomyocyte dedifferentiation may be an important source of proliferating cardiomyocytes facilitating cardiac repair. Cardiomyocyte dedifferentiation and proliferation induced by oncostatin-M (OSM) is characterized by sarcomere degeneration. However, the mechanism underlying sarcomere degeneration remains unclear. We hypothesized that this process may involve matrix metalloproteinase-2 (MMP-2), a key protease localized at the sarcomere in cardiomyocytes. We tested the hypothesis that MMP-2 is involved in the sarcomere degeneration that characterizes cardiomyocyte dedifferentiation. Confocal immunofluorescence and biochemical methods were used to explore the role of MMP-2 in OSM-induced dedifferentiation of neonatal rat ventricular myocytes (NRVM). OSM caused a concentration- and time-dependent loss of sarcomeric α-actinin and troponin-I in NRVM. Upon OSM-treatment, the mature sarcomere transformed to a phenotype resembling a less-developed sarcomere, i.e., loss of sarcomeric proteins and Z-disk transformed into disconnected Z bodies, characteristic of immature myofibrils. OSM dose dependently increased MMP-2 activity. Both the pan-MMP inhibitor GM6001 and the selective MMP-2 inhibitor ARP 100 prevented sarcomere degeneration induced by OSM treatment. OSM also induced NRVM cell cycling and increased methyl-thiazolyl-tetrazolium (MTT) staining, preventable by MMP inhibition. These results suggest that MMP-2 mediates sarcomere degeneration in OSM-induced cardiomyocyte dedifferentiation and thus potentially contributes to cardiomyocyte regeneration.

Abstract 16870: Dissociation of Mitochondrial HK-II Triggers Mitochondria Specific Autophagy

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Shigeki Miyamoto ◽  
David J Roberts ◽  
Valerie P Tan-Sah
Keyword(s):  
Energy Production ◽  
Ventricular Myocytes ◽  
Neonatal Rat ◽  
Mouse Heart ◽  
Hexokinase Ii ◽  
Survival Pathway ◽  
Mitochondrial Membrane Depolarization ◽  
Neonatal Rat Ventricular Myocytes

Introduction: There is emerging evidence that the metabolic pathway interplays with the survival pathway to preserve cellular homeostasis. Hexokinases (HKs) catalyze the first step of glucose metabolism and hexokinase-II (HK-II) is the predominant isoform in the heart. Our recent study revealed that HK-II positively regulates general autophagy in the absence of glucose. Mitochondrial HK-II (mitoHK-II) is regulated by Akt and provides cardioprotection while it is decreased in the ischemic heart. Hypothesis: We tested the hypothesis that mitoHK-II dissociation triggers mitochondria specific autophagy (mitophagy). Results: As previously reported, mitoHK-II levels were decreased by ~40% in the perfused mouse heart subjected to global ischemia and in neonatal rat ventricular myocytes (NRVMs) subjected to simulated ischemia. To assess the role of mitoHK-II dissociation, mitoHK-II dissociating peptide (15NG) was expressed in NRVMs. MitoHK-II was decreased by 40% in NRVMs expressing 15NG which was accompanied with Parkin translocation to mitochondria and ubiquitination of mitochondrial proteins. This response was attenuated by Parkin knockdown and reversed by the recovery of mitoHK-II by co-expression of HK-II but not by that of mitochondria binding deficient mutant. 15NG expression did not induce mitochondrial membrane depolarization nor PINK1 stabilization at mitochondria, suggesting that the effects of mitoHK-II dissociation is not dependent on the previously established mitochondria depolarization/PINK1 pathway. This was confirmed by the experiments using PINK1 siRNA. Modest dissociation of mitoHK-II (by 20%) did not induce mitophagic responses but remarkably enhanced FCCP induced mitophagy, indicating that these two pathways are synergetic. We will be analyzing 15NG transgenic mice generated in our lab to determine the mitophagic role of mitoHK-II dissociation in vivo. Conclusions: These results suggest that mitoHK-II dissociation can regulate Parkin dependent mitophagy, in conjunction with depolarization dependent mechanisms and that HK-II could confer cardioprotection by switching the cell from an energy production to an energy conservation mode under ischemia.

scholarly journals Stimulation of multiple mitogen-activated protein kinase sub-families by oxidative stress and phosphorylation of the small heat shock protein, HSP25/27, in neonatal ventricular myocytes

1998 ◽  
Vol 333 (3) ◽  
pp. 581-589 ◽  
Author(s):  
Angela CLERK ◽  
Ashour MICHAEL ◽  
Peter H. SUGDEN
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase ◽  
P38 Mapk ◽  
Ventricular Myocytes ◽  
Small Heat Shock Protein ◽  
Neonatal Rat ◽  
Mitogen Activated Protein ◽  
Powerful Activator ◽  
Neonatal Rat Ventricular Myocytes ◽  
Stimulation Of

We investigated the activation of three subfamilies of mitogen-activated protein kinases (MAPKs), namely the stress-activated protein kinases/c-Jun N-terminal kinases (SAPKs/JNKs), the extracellularly responsive kinases (ERKs) and p38-MAPK, by oxidative stress as exemplified by H2O2 in primary cultures of neonatal rat ventricular myocytes. The 46 and 54 kDa species of SAPKs/JNKs were activated 5- and 10-fold, respectively, by 0.1 mM H2O2 (the maximally effective concentration). Maximal activation occurred at 15–30 min, but was still detectable after 2 h. Both ERK1 and ERK2 were activated 16-fold by 0.1 mM H2O2 with a similar time course to the SAPKs/JNKs, and this was comparable with their activation by 1 µM PMA, the most powerful activator of ERKs that we have so far identified in these cells. The activation of ERKs by H2O2 was inhibited by PD98059, which inhibits the activation of MAPK (or ERK) kinases, and by the protein kinase C (PKC) inhibitor, GF109203X. ERK activation was also inhibited by down-regulation of PMA-sensitive PKC isoforms. p38-MAPK was activated by 0.1 mM H2O2 as shown by an increase in its phosphorylation. However, maximal phosphorylation (activation) was more rapid (< 5 min) than for the SAPKs/JNKs or the ERKs. We studied the downstream consequences of p38-MAPK activation by examining activation of MAPK-activated protein kinase 2 (MAPKAPK2) and phosphorylation of the MAPKAPK2 substrate, the small heat shock protein HSP25/27. As with p38-MAPK, MAPKAPK2 was rapidly activated (maximal within 5 min) by 0.1 mM H2O2. This activation was abolished by 10 µM SB203580, a selective inhibitor of certain p38-MAPK isoforms. The phosphorylation of HSP25/27 rapidly followed activation of MAPKAPK2 and was also inhibited by SB203580. Phosphorylation of HSP25/27 was associated with a decrease in its aggregation state. These data indicate that oxidative stress is a powerful activator of all three MAPK subfamilies in neonatal rat ventricular myocytes. Activation of all three MAPKs has been associated with the development of the hypertrophic phenotype. However, stimulation of p38-MAPK and the consequent phosphorylation of HSP25/27 may also be important in cardioprotection.

Abstract 307: Phospholipase Cε Is Involved in Gq-Dependent Protein Kinase D Activation in Cardiac Myocytes

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Alan Smrcka ◽  
Lianghui Zhang ◽  
Sundeep Malik
Keyword(s):  
Protein Kinase ◽  
G Proteins ◽  
Ventricular Myocytes ◽  
Neonatal Rat ◽  
Protein Kinase D ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Neonatal Rat Ventricular Myocytes ◽  
Phospholipase Cε

We previously demonstrated that PLCε is a critical mediator of endothelin-1 (ET-1)- and norepinephrine (NE)-dependent hypertrophy in neonatal rat ventricular myocytes (NRVMs). Both α-adrenergic and ET-1 receptors couple to Gq as well as other G proteins. To determine if PLCε is required for Gαq-dependent hypertrophy NRVMs were infected with adenoviruses expressing wtGαq and PLCε siRNA followed by measurement of hypertrophy. PLCε-siRNA significantly inhibited Gαq-induced increases in myocyte area and atrial natriuretic factor (ANF) mRNA expression. Similarly, disruption of PLCε association with perinuclear mAKAP inhibited Gαq-dependent hypertrophy. These data suggest that ET-1 and PE signal, at least in part, through Gαq and PLCε. To explore the functional role of PLCε in ET-1/Gq dependent hypertrophy, activation of protein kinase D (PKD) in NRVMs was assessed in response to ET-1. PLCε-siRNA significantly inhibited ET-1 induced PKD activation (∼50% inhibition). Disruption of PLCε-mAKAP interactions also significantly inhibited ET-1 induced PKD activation (∼50% inhibition). We propose that PLCε scaffolded to mAKAP at the nuclear envelope responds to Gαq-dependent, as well as other hypertrophic signals, to locally regulate PKD in a process that is critical for hypertrophy development.

scholarly journals Protective Role of Peroxiredoxins against Reactive Oxygen Species in Neonatal Rat Testicular Gonocytes

Antioxidants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 32 ◽  
Author(s):  
Cristian O’Flaherty ◽  
Annie Boisvert ◽  
Gurpreet Manku ◽  
Martine Culty
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Gene Array ◽  
Reactive Oxygen ◽  
Fold Increase ◽  
Protective Role ◽  
Neonatal Rat ◽  
Oxygen Species ◽  
Antioxidant Genes

Peroxiredoxins (PRDXs) are antioxidant enzymes that protect cells from oxidative stress and play a role in reactive oxygen species (ROS)-mediated signaling. We reported that PRDXs are critical for human fertility by maintaining sperm viability and regulating ROS levels during capacitation. Moreover, studies on Prdx6−/− mice revealed the essential role of PRDX6 in the viability, motility, and fertility competence of spermatozoa. Although PRDXs are abundant in the testis and spermatozoa, their potential role at different phases of spermatogenesis and in perinatal germ cells is unknown. Here, we examined the expression and role of PRDXs in isolated rat neonatal gonocytes, the precursors of spermatogonia, including spermatogonial stem cells. Gene array, qPCR analyses showed that PRDX1, 2, 3, 5, and 6 transcripts are among the most abundant antioxidant genes in postnatal day (PND) 3 gonocytes, while immunofluorescence confirmed the expression of PRDX1, 2, and 6 proteins. The role of PRDXs in gonocyte viability was examined using PRDX inhibitors, revealing that the 2-Cys PRDXs and PRDX6 peroxidases activities are critical for gonocytes viability in basal condition, likely preventing an excessive accumulation of endogenous ROS in the cells. In contrast to its crucial role in spermatozoa, PRDX6 independent phospholipase A2 (iPLA2) activity was not critical in gonocytes in basal conditions. However, under conditions of H2O2-induced oxidative stress, all these enzymatic activities were critical to maintain gonocyte viability. The inhibition of PRDXs promoted a two-fold increase in lipid peroxidation and prevented gonocyte differentiation. These results suggest that ROS are produced in neonatal gonocytes, where they are maintained by PRDXs at levels that are non-toxic and permissive for cell differentiation. These findings show that PRDXs play a major role in the antioxidant machinery of gonocytes, to maintain cell viability and allow for differentiation.

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