ABSTRACT
BACKGROUND: Prostaglandin-E1 (PGE1) is a potent vasodilator with anti-inflammatory and antiplatelet effects. However, the mechanism by which PGE1 contributes to the amelioration of cardiac injury remains unclear. METHODS: The present study was designed to investigate how PGE1 protects against hypoxia/reoxygenation (H/R)-induced injuries by regulating microRNA-21-5p (miR-21-5p) and fas ligand (FASLG). Rat H9C2 cells and isolated primary cardiomyocytes were cultured under hypoxic conditions for 6 h (6H, hypoxia for 6 h), and reoxygenated for periods of 6 (6R, reoxygenation for 6 h), 12, and 24 h, respectively. Cells from the 6H/6R group were treated with various doses of PGE1; after which, their levels of viability and apoptosis were detected. RESULTS: The 6H/6R treatment regimen induced the maximum level of H9C2 cell apoptosis, which was accompanied by the highest levels of Bcl-2-associated X protein (Bax) and cleaved-caspase-3 expression and the lowest level of B-cell lymphoma 2 (Bcl-2) expression. Treatment with PGE1 significantly diminished the cell cytotoxicity and apoptosis induced by the 6H/6R regimen, and also decreased expression of IL-2, IL-6, P-p65, TNF-α, and cleaved-caspase-3. In addition, we proved that PGE1 up-regulated miR-21-5p expression in rat cardiomyocytes exposed to conditions that produce H/R injury. FASLG was a direct target of miR-21-5p, and PGE1 reduced the ability of H/R-injured rat cardiomyocytes to undergo apoptosis by affecting the miR-21-5p/FASLG axis. In addition, we proved that PGE1 could protect primary cardiomyocytes against H/R-induced injuries. CONCLUSIONS: These results indicate that PGE1 exerts cardioprotective effects in H9C2 cells during H/R by regulating the miR-21-5p/FASLG axis.
Subject(s)
Alprostadil/pharmacology , Fas Ligand Protein/genetics , MicroRNAs/genetics , Myocardial Reperfusion Injury/drug therapy , Reperfusion Injury/drug therapy , Animals , Apoptosis/drug effects , Cell Hypoxia/drug effects , Cell Hypoxia/genetics , Disease Models, Animal , Gene Expression Regulation/drug effects , Humans , Myocardial Reperfusion Injury/genetics , Myocardial Reperfusion Injury/pathology , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Protective Agents/pharmacology , Rats , Reperfusion Injury/genetics , Reperfusion Injury/pathology , Signal Transduction/drug effectsABSTRACT
Programmed cell death plays an important role in cardio protection, and Notch1 was an important factor related to programmed cell death. The role of Notch1 on ischemia myocardium remains unclear.H9C2 myocardial cells were cultured with routine medium, transfected with Notch1 over expression plasmid, Notch1-siRNA-overexpression plasmid and vehicle plasmid for further hypoxic experiment. Condition of hypoxic experiment was 1% oxygen centration and culturing for 12hours, then the cell proliferation activity and apoptosis rate was assessed by MTS kit and flow cytometry, respectively. The expressions of Caspase-3, Caspase-9 and Bcl-2 were determined by RT-qPCR and Western Blot, respectively. Compared with normoxia treatment, hypoxia could decrease H9C2 cell proliferation activity as well as Bcl-2 mRNA expression, and increase cell apoptosis rate as well as Caspase-3 and Caspase-9 mRNA expression. Notch1 activation could increase proliferation activity as well as Bcl-2 mRNA expression, while decrease apoptosis rate as well as Caspase-3 and Caspase-9 mRNA expression. Compared with Notch1 activation H9C2 cells, the opposite effect on programmed cell death was observed in cells with Notch1-siRNA-overexpression plasmid. Targeted activation of Notch1 gene to reduce hypoxia-induced programmed cell death in myocardial cells via up-regulating the expression of Caspase-3 and Caspase-9 and inhibiting the expression of Bcl-2.
Subject(s)
Apoptosis , Myocardial Ischemia/prevention & control , Myocytes, Cardiac/metabolism , Receptor, Notch1/metabolism , Animals , Apoptosis Regulatory Proteins/genetics , Apoptosis Regulatory Proteins/metabolism , Cell Hypoxia , Cell Line , Myocardial Ischemia/genetics , Myocardial Ischemia/metabolism , Myocardial Ischemia/pathology , Myocytes, Cardiac/pathology , Rats , Receptor, Notch1/genetics , Signal TransductionABSTRACT
Apolipoprotein M (apoM), a novel human apolipoprotein recently discovered, predominantly presents in high density lipoprotein (HDL) in plasma, exclusively expressed in liver and in kidney. The present data demonstrated apoM protects against atherosclerosis (AS) primarily via partaking in prebeta-HDL formation and promoting cholesterol efflux to HDL. However, this lipid-metabolism-associated pathway seems unlikely responsible for all atheroprotective effects of apoM. Notably, the human apoM gene is just located in the major histocompatibility complex class III region (MHC-III) on chromosome 6, many genes in this region are related to the immune and inflammatory response. Furthermore, apoM has been documented to link with some inflammatory factors including platelet activating factor (PAF) and leptin. These evidences indicate that apoM may be involved in inflammatory activities in vivo and the potential immuno- and inflam-reactive property of apoM may contribute to the anti-inflammatory function of HDL, as generally acknowledged as an important atheroprotective mechanism of HDL.
