Abstract:

Objective   To explore the effect of NAD on the mRNA expression of collagen type I induced by angiotensin II in cardiac fibroblasts in vitro．Methods   Neonatal rat cardiac fibroblasts  were isolated from wistar rats and then cultured. The generation 2-4 were used for the experiment and treated as follows: control group, Ang II (0.01， 0.1，  1μmol／L) group，NAD (250μmol／L )group, Ang II (1μmol／L)+ NAD (250μmol／L )group, FAM group, Sirt1-siRNA+AngII (1μmol／L) group, Sirt1-siRNA group, Sirt1-siRNA+NAD（250μmol／L）group and Sirt1-siRNA+ Ang II (1μmol／L)+NAD（250μmol／L）group.  24 hours later, the mRNA expressions of SIRT1 and collagen I were measured by real time reverse transcription-polymerase chain reaction(Real time RT-PCR)． Results   After treatment with Ang II for 24 hours，the mRNA expression of collagen I was enhanced in a Ang II dose-dependent manner(P＜0.05). In contrast with control group, the mRNA expression of SIRT1 was enhanced after being treated with NAD（250μmol／L）(P＜0.05) and the mRNA expression of collagen I in AngII (1μmol／L)+ NAD (250μmol／L) group was attenuated compared with Ang II (1μmol／L) group (P＜0.01).  Compared with FAM group, SIRT1 mRNA expression was attenuated(P＜0.05) and collagen I mRNA expression was increased (P＜0.05) in the other groups．Conclusion   The results suggest that NAD and SIRT1 may be beneficial to cardiac fibrosis by attenuating the mRNA expression of collagen type I induced by Ang II in cardiac fibroblatsts.

Key words: Nicotinamide adenine dinucleotide; Collagen I; Angiotensin II; Fibrosis; Cardiac remodeling; SIRT1