Exogenous NAD(+) supplementation protects H9c2 cardiac myoblasts against hypoxia/reoxygenation injury via Sirt1-p53 pathway.

Abstract

Nicotinamide adenine dinucleotide (NAD(+) ) not only transfers electrons in mitochondrial respiration, but also acts as an indispensable cosubstrate for Sirt1, the class III histone/nonhistone deacetylase. However, NAD(+) is depleted in myocardial ischemia/reperfusion (IR) injury. The objective of this study was to investigate the role of exogenous NAD(+) supplementation in hypoxia/reoxygenation (HR)-stressed H9c2 cardiac myoblasts. Firstly, the effects of distinct treating time points and doses of NAD(+) supplementation on the viability of HR-stressed H9c2 cells were detected. Secondly, intracellular NAD(+) levels in HR-stressed H9c2 cells at various extracellular NAD(+) concentrations were determined. Thirdly, the role of NAD(+) supplementation in HR-induced cell apoptosis and its relevance to Sirtuin 1-p53 pathway were investigated. Exogenous NAD(+) supplementation elevated intracellular NAD(+) level and reduced HR-induced cell death in both time- and concentration-dependent manners. It appeared that NAD(+) supplementation exerted the greatest protection when extracellular concentration ranged from 500 to 1000 μm and when NAD(+) was added immediately after reoxygenation began. NAD(+) replenishment restored Sirt1 activity, reduced the acetylation level of p53 (Lys373 & 382), and attenuated cell apoptosis in HR-stressed H9c2 cells, whereas inhibition of Sirt1 activity alleviated the effects of NAD(+) replenishment. These results indicated that exogenous NAD(+) supplementation attenuated HR-induced cell apoptosis, which was at least partly mediated by restoring Sirt1 activity and subsequently inhibiting p53 activity via deacetylating p53 at lysine 373 and 382.

• Authors: Ling Liu, Ping Wang, Xinwei Liu, Dongwei He, Canxin Liang, Ying Yu
• Journal: Fundamental & clinical pharmacology (Fundam Clin Pharmacol) Vol. 28 Issue 2 Pg. 180-9 (Apr 2014) ISSN: 1472-8206 [Electronic] England
• PMID: 23384296 (Publication Type: Journal Article)
• Copyright: © 2012 The Authors Fundamental and Clinical Pharmacology © 2012 Société Française de Pharmacologie et de Thérapeutique. Published by John Wiley & Sons Ltd.

Chemical References

• Tumor Suppressor Protein p53
• NAD
• Sirt1 protein, rat
• Sirtuin 1
• Oxygen

Topics

• Animals
• Apoptosis (drug effects)
• Cell Culture Techniques
• Cell Hypoxia (drug effects)
• Cell Line
• Cell Survival (drug effects)
• Dose-Response Relationship, Drug
• Myoblasts, Cardiac (drug effects, metabolism, pathology)
• Myocardial Reperfusion Injury (metabolism)
• NAD (metabolism, pharmacology)
• Oxygen (metabolism)
• Rats
• Signal Transduction (drug effects)
• Sirtuin 1 (metabolism)
• Time Factors
• Tumor Suppressor Protein p53 (metabolism)