TMSN-AA纳米复合物促进人胚胎干细胞向心肌细胞分化的潜在机制研究

Effect of TMSN-AA nanocomposites on promoting differentiation of hESCs into cardiomyocytes

目的研究优化后的TMSN-AA纳米复合物促进人胚胎干细胞(h ESCs)心肌分化的可能性,并探讨其诱导心肌分化的潜在机制。方法采用优化抗坏血酸(AA)负载的荧光TRITC介孔二氧化硅纳米粒子(TMSN-AA)作为诱导剂,诱导h ESCs细胞心肌分化。通过荧光定位检测该诱导剂进入细胞情况,流式细胞仪检测其进入细胞后对细胞存活与凋亡的影响,Western blot检测TMSN-AA诱导后,心肌标记基因cTn I、FLK-1以及干性基因OCT4和SOX2的表达以及相关信号通路ERK1/2的激活情况。结果荧光定位发现TMSN-AA可以靶向进入h ESCs细胞,流式细胞仪分析结果显示,二氧化硅和荧光染料四甲基罗丹明修饰介孔二氧化硅不会影响h ESCs的存活和凋亡;且TMSN-AA诱导后,干性基因OCT4和SOX2均下调,且上调心肌标记基因c Tn I和FLK-1的表达。Western blot检测结果显示,TMSN-AA的处理可以激活ERK1/2信号通路,同时证实,该过程Akt信号通路并未参与其中。结论优化后的TMSN-AA纳米载体可以成功进入h ESCs细胞,并靶向诱导其心肌分化,而该诱导过程,至少在一定程度上是通过激活ERK1/2,而不是Akt信号通路实现的。

Objective To investigate the effect of TRITC mesoporous silica nanoparticles （TMSN-AA） nanocomposite in promoting differentiation of hESCs into cardiomyocyte and potential mechanisms. Methods TMSN-AA loaded with ascorbic acid （AA） was used as an stimulation to induce differentiation of hESCs into cardiomyocytes. Expression of cTnI, FLK-1, SOX2 and OCT4 were measured by western blot. Activation of ERK1/2 pathway was also detected. Results Fluorescence localization analysis showed that TMSN-AA successfully moved into hESCs. Flow cytometry analysis indicated that MSN and TMSN did not affect hESCs growth. Expressions of cTnI and FLK-1 were up-regulated while OCT4 and SOX2 were down-regulated by TMSN-AA. Western blot suggested that TMSN-AA treatment activated ERK1/2 signaling pathway without involvement of Akt signaling pathway. Conclusion TMSN-AA nanocarrier may be a good approach for induction of hESCs differentiation through activating ERK1/2 signaling pathway.