Jumonji is a potential regulatory factor mediating nitric oxide-induced modulation of cardiac hypertrophy.

Background And Objectives: Jumonji (jmj) is the prototypical member of the jmj domain-containing protein family. It regulates the expression of several genes, in particular genes involved in cardiac cell growth in the embryonic heart. The function of jmj in the mature or developed heart, however, is unclear.

The metalloporphyrin FeTPPS but not by cyclosporin A antagonizes the interaction of peroxynitrate and hydrogen peroxide on cardiomyocyte cell death.

The objective of this study was to determine whether the metalloporphyrin, 5,10,15,20-tetrakis(4-sulfonatophenyl) porphyrinato iron (III) chloride (FeTPPS), antagonized the effect of peroxynitrite, oxygen-free radicals, and the combination of the two, on cardiomyocyte cell viability. We further sought to compare the effects of FeTPPS to an inhibitor of the mitochondrial transmembrane permeability transition pores (PTP)-cyclosporin A. Cardiomyocytes from embryonic chick heart were treated with 3-morpholinosydnonimine (SIN-1), which decomposes to liberate NO and superoxide anion (O(2) (-)) which in turn generates peroxynitrite.

Metalloporphyrins as a therapeutic drug class against peroxynitrite in cardiovascular diseases involving ischemic reperfusion injury.

Peroxynitrite is well-recognized as being capable of inducing damaging cellular effects and has been identified as a mediator of cell damage in numerous disease states, including cardiovascular diseases. Metalloporphyrins are a class of molecule that represents an exciting new pharmacological approach to reducing peroxynitrite levels. These compounds catalyze the conversion of the harmful peroxynitrite molecules into less toxic derivatives and can be considered the reasonable intervention to reduce the toxicity of peroxynitrite.

Palmitate-induced NO production has a dual action to reduce cell death through NO and accentuate cell death through peroxynitrite formation.

The objective of this study was to determine the role of palmitate-induced stimulation of nitric oxide synthase (NOS) on palmitate-induced cell death, specifically distinguishing the effects of the subtype NOS2 from NOS3, defining the effect of NO on mitochondria death pathways, and determining whether palmitate induces peroxynitrite formation which may impact cardiomyocyte cell survival. Cardiomyocytes from embryonic chick hearts were treated with palmitate 300-500 microM. Cell death was assessed by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay.

Sodium nitroprusside activates p38 mitogen activated protein kinase through a cGMP/PKG independent mechanism.

The objective of this study was to understand the mechanism of action of nitric oxide (NO) in the heart by determining whether nitric oxide (NO) released from sodium nitroprusside (SNP) induces p38 mitogen activated protein kinase (p38 MAPK) phosphorylation and whether this is mediated through a cyclic GMP (cGMP)/protein kinase G (PKG) pathway. p38 MAPK activation was examined by Western blotting of whole cell lysates of embryonic chick cardiomyocytes with antibodies specific to the native or phosphorylated forms of p38 MAPK. SNP, 1 mM, which released significant amounts of NO as determined by Griess reaction, induced p38 MAPK phosphorylation that was apparent within 10 min, was significantly (p<0.

The role of p53 in nitric oxide-induced cardiomyocyte cell death.

The role of p53 in mediating nitric oxide (NO)-induced cell death remains uncertain. The exogenous NO donor S-nitrosoglutathione (GSNO) produced a concentration-dependent reduction in cell viability in embryonic chick cardiomyocytes in culture. Western blotting and immunocytochemistry for p53 showed that p53 was increased in whole cell lysates by GSNO: 0.

Omapatrilat enhances adrenomedullin's reduction of cardiomyocyte cell death.

The objective of this study was to determine whether adrenomedullin, a vasodilator peptide, modulates the process of cell death in cardiomyocytes and whether its effect would be enhanced by the endopeptidase inhibitor omapatrilat, which reduces adrenomedullin degradation. Further, we sought to determine whether the effect of adrenomedullin involved an action to preserve mitochondrial transmembrane potential (DeltaPsi(m)). Cardiomyocytes in culture were treated with agents that interrupted the mitochondrial electron transport chain, inhibiting glycolysis and oxidative phosphorylation.

Nitric oxide differentially regulates the gene expression of caspase genes but not some autophagic genes.

Nitric oxide (NO) is fundamentally important molecule which produces a wide range of cellular effects with the most poorly understood one being alteration in the sensitivity to cell death. The objective of this study was to test the hypothesis that NO would differentially affect caspase or autophagy gene expression in a manner that might account for the disparate actions of NO to either enhance or protect against cell death. Neonatal mouse cardiomyocytes in culture were treated with the NO donor SIN-1 (3-morpholinosydnonimine hydrochloride) for up to 20 h.

Ceramide activates a mitochondrial p38 mitogen-activated protein kinase: a potential mechanism for loss of mitochondrial transmembrane potential and apoptosis.

This study examined the impact of ceramide, an intracellular mediator of apoptosis, on the mitochondria to test the hypothesis that ceramide utilized p38 MAPK in the mitochondria to alter mitochondrial potential and induce apoptosis. The capacity of ceramide to adversely affect mitochondria was demonstrated by the significant loss of mitochondrial potential (DeltaPsim), indicated by a J-aggregate fluorescent probe, after embryonic chick cardiomyocytes were treated with the cell permeable ceramide analogue C2-ceramide. p38 MAPK was identified in the mitochondrial fraction of the cell and p38 MAPK phosphorylation in this mitochondrial fraction of the cell occurred with ceramide treatment.