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

摘要:

目的 研究优化后的TMSN-AA 纳米复合物促进人胚胎干细胞（hESCs）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hESCs 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cTnI 、 FLK -1 以及干性基因OCT 4 和SOX 2 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hESCs 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hESCs 的存活和凋亡；且TMSN-AA 诱导后，干性基因OCT 4 和SOX 2 均下调，且上调心 肌标记基因cTnI 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hESCs 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。

Abstract:

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.