CARM1维持羊水干细胞干性的机制

CARM1 is required to maintain stemness of amniotic fluid-derived stem cells

背景:研究表明,CARM1催化的组蛋白H3R17/R26的甲基化修饰对于胚胎干细胞干性的维持起着非常重要的作用,但其在羊水干细胞干性维持中的作用及机制目前尚不明确。目的:初步探讨CARM1在维持羊水干细胞干性中的作用及其分子机制。方法:分离、培养人妊娠晚期羊水干细胞,RT-PCR鉴定干细胞标志物及CARM1基因的表达。利用CARM1的两条shR NA慢病毒表达载体,沉默羊水干细胞中CARM1基因的表达。RT-qP CR检测CARM1基因的表达沉默效率,Western blot检测组蛋白H3R17的甲基化水平。RT-qP CR检测干细胞标志物OCT4,SOX2和NANOG基因的表达水平。结果与结论:(1)人妊娠晚期羊水干细胞能够表达干细胞标志物,包括OCT4、SOX2、Nanog和KLF4,并表达CARM1基因;(2)CARM1的两条shR NA均能够有效沉默CARM1基因的表达;(3)CARM1表达沉默后,羊水干细胞中组蛋白H3R17的甲基化水平降低,OCT4和SOX2的表达也降低,而NANOG的表达没有发生变化;(4)结果表明,CARM1可能通过调控OCT4和SOX2基因的表达,进而起到维持羊水干细胞干性的作用。

BACKGROUND： Studies have shown that methylation modification using CARM1-catalyzed histone H3R17/R26 can maintain the stemness of embryonic stem cells. However, mechanism underlying CARM1 effect on the stemness of amniotic fluid-derived stem cells is still unclear. OBJECTIVE： To investigate the function and underlying molecular mechanism of CARM1 to maintain stemness in the amniotic fluid-derived stem cells. METHODS： Amniotic fluid-derived stem cells from term pregnancy were isolated and cultured. RT-PCR was used to identify the stem cell mark and CARM1 gene expression. CARM1 expression in amniotic fluid-derived stem cells was knocked down by using two sh RNA. RT-qP CR was used to detect the silencing efficiency, and western blot employed to examine the methylation level of Arginines 17 at N terminus of histone 3（H3mR 17）. Moreover, the expression of embryonic stem cell markers, including OCT4, SOX2 and NANOG, were detected. RESULTS AND CONCLUSION： Amniotic fluid-derived stem cells from term pregnancy could express CARM1 and stem cell markers, including OCT4, SOX2, Nanog and KLF4. Both of the sh RNAs could knock down the expression of CARM1 efficiently. When CARM1 was knocked down, the H3 m R17 level was decreased and OCT4, SOX2 expression was also reduced, but NANOG expression had no change. All these indicate that CARM1 is required for amniotic fluid-derived stem cells to maintain stemness through regulating OCT4 and SOX2 expression.