Feng Chuan, Zhu Jing, Zhao Lili, Lu Tiewei, Zhang Wen, Liu Zhenguo, Tian Jie
Department of Cardiology, Children's Hospital of Chongqing Medical University, People's Republic of China.
Exp Cell Res. 2009 Oct 15;315(17):3044-51. doi: 10.1016/j.yexcr.2009.05.005. Epub 2009 May 13.
This study was to investigate the effect of suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, on cardiomyocyte differentiation of bone marrow mesenchymal stem cells (MSCs) in vitro. Rat MSCs were isolated and induced to differentiate into cardiomyocyte with SAHA or 5-azacytidine (5-aza, a DNA methylation inhibitor) or their combination. Following 7 days of SAHA treatment, the transcriptional expression of the cardiomyocyte-specific genes GATA4, NKx2.5, and Mef2c was dose-dependently increased in the cells with up to 15-fold increase in their mRNA levels over baseline. However, the mRNA levels of these genes were only increased by 2-4 fold in 5-aza-treated cells. After 4 weeks of induction with SAHA, cTnT protein content was substantially increased dose-dependently by up to 8-fold in the cells over the baseline. In contrast, only minimal cTnT protein was found in 5-aza-treated cells. When MSCs were treated with both SAHA and 5-aza, the mRNA levels of GATA4, NKx2.5, and Mef2c and cTnT protein content were the same as those in the cells treated with SAHA alone. These results indicate that SAHA effectively promotes cardiomyocyte differentiation of rat MSCs in vitro. SAHA was a much more potent inducer for cardiac differentiation of MSCs then 5-aza. Our data also indicate that no synergistic or antagonistic effect between SAHA and 5-aza on cardiomyocyte differentiation of MSCs is present, and histone acetylation, not DNA demethylation, may be the dominant mechanism that determines the cardiac differentiation of rat MSCs.
本研究旨在探讨组蛋白去乙酰化酶抑制剂辛二酰苯胺异羟肟酸（SAHA）对体外培养的骨髓间充质干细胞（MSCs）向心肌细胞分化的影响。分离大鼠MSCs，用SAHA或5-氮杂胞苷（5-aza，一种DNA甲基化抑制剂）或二者联合诱导其分化为心肌细胞。SAHA处理7天后，心肌细胞特异性基因GATA4、NKx2.5和Mef2c的转录表达呈剂量依赖性增加，细胞中其mRNA水平比基线水平最高增加了15倍。然而，在5-aza处理的细胞中，这些基因的mRNA水平仅增加了2-4倍。用SAHA诱导4周后，细胞中的心肌肌钙蛋白T（cTnT）蛋白含量呈剂量依赖性显著增加，比基线水平最高增加了8倍。相比之下，在5-aza处理的细胞中仅发现极少的cTnT蛋白。当MSCs同时用SAHA和5-aza处理时，GATA4、NKx2.5和Mef2c的mRNA水平以及cTnT蛋白含量与单独用SAHA处理的细胞相同。这些结果表明，SAHA在体外可有效促进大鼠MSCs向心肌细胞分化。SAHA是比5-aza更有效的MSCs向心肌分化的诱导剂。我们的数据还表明，SAHA和5-aza之间对MSCs向心肌细胞分化不存在协同或拮抗作用，决定大鼠MSCs向心肌分化的主要机制可能是组蛋白乙酰化，而非DNA去甲基化。
