Effects of the histone acetylase inhibitor C646 on growth and differentiation of adipose-derived stem cells

As an important histone acetylase, the transcriptional coactivator P300/CBP affects target gene expression and plays a role in the maintenance of stem cell characteristics and differentiation potential. In this study, we explored the action of a highly effective selective histone acetylase inhibitor, C646, on goat adipose-derived stem cells (gADSCs), and investigated the impact of histone acetylation on the growth characteristics and the differentiation potential of ADSCs. We found that C646 blocked the cell proliferation, arrested the cell cycle, and triggered apoptosis. Notably, immunocytochemistry and western blot analyses showed that the acetylation level of histone H3K9 was increased. Moreover, although real-time quantitative PCR and western blot confirmed that P300 expression was inhibited under these conditions, the expression level of two other histone acetylases, TIP60 and PCAF, was significantly increased. Furthermore, C646 clearly promoted the differentiation of gADSCs into adipocytes and had an impact on their differentiation into neuronal cells. This study provides new insights into the epigenetic regulation of stem cell differentiation and may represent an experimental basis for the comprehension of stem cell characteristics and function. Furthermore, it is of great relevance for the application of adult stem cells to somatic cell cloning, which may improve the efficiency of large livestock cloning and foster the production of transgenic animals.

作为一类重要的组蛋白乙酰转移酶（histone acetylase），转录共激活因子P300/CBP可影响靶基因（target gene）的表达，在维持干细胞特性与分化潜能中发挥关键作用。本研究探究了高效选择性组蛋白乙酰转移酶抑制剂（histone acetylase inhibitor）C646对山羊脂肪间充质干细胞（goat adipose-derived stem cells，gADSCs）的作用，并解析了组蛋白乙酰化（histone acetylation）对脂肪间充质干细胞（adipose-derived stem cells，ADSCs）生长特性及分化潜能的影响。研究发现，C646可阻滞细胞增殖、使细胞周期停滞并诱导细胞凋亡。值得注意的是，免疫细胞化学（immunocytochemistry）与蛋白质印迹（Western Blot）分析结果显示，组蛋白H3K9的乙酰化水平升高。此外，尽管实时荧光定量聚合酶链式反应（real-time quantitative PCR）与蛋白质印迹实验证实，P300的表达在该处理条件下受到抑制，但另外两种组蛋白乙酰转移酶TIP60与PCAF的表达水平显著上调。进一步研究表明，C646可显著促进山羊脂肪间充质干细胞向脂肪细胞（adipocytes）分化，并对其向神经元细胞（neuronal cells）分化产生影响。本研究为干细胞分化的表观遗传调控（epigenetic regulation）机制提供了新的见解，可为理解干细胞特性与功能奠定实验基础。此外，该研究对于成体干细胞在体细胞克隆领域的应用具有重要参考价值，有望提升大型家畜克隆效率并推动转基因动物的制备。