小鼠胚胎干细胞自我更新的信号调控机制

小鼠胚胎干细胞是一种全能干细胞，具有体内体外全能分化特性。体外培养时能够进行自我更新，即细胞通过对称分裂在维持全能性不丢失的情况下细胞数目增多。全能性维持受多条信号通路的调控，其中gp130下游的JAK-STAT3及P13K通路的活化能维持胚胎干细胞的自我更新，而SHP2-Ras-ERK的激活则促使胚胎干细胞分化。无血清条件下BMP4激活的通路与JAK-STAT3联合作用可保持胚胎干细胞的全能性。此外，Wnt信号通路的活化也参与对胚胎干细胞的自我更新的调控。总之，多种信号通路形成的网络精确调控小鼠胚胎干细胞的自我更新与分化。本文主要综述gp130在小鼠ES细胞增殖过程中作用，包括JAK-STAT3通路活化抑制小鼠ES细胞分化，P13K通路活化维持ES细胞的自我更新和SHP-2-Ras通路活化促进ES细胞分化，以及其他信号通路对小鼠ES细胞自我更新的影响，包括无血清条件下BMP联合LIF能维持ES细胞的高度自我更新，Wnt信号通路活化促进ES细胞自我更新。

Signaling Pathways Regulating Self-renewal of Mouse Embryonic Stem Cells——Review

Mouse embryonic stem cells (ES cells) are pluripotent in that they can give rise to almost all the cell types in vitro and in vivo. Also, they can sustain self-renewal in vitro owing to symmetrical mitosis, i.e., only the cell number increases while the daughter cells remain pluripotent. Self-renewal and pluripotency of ES cells are under stringent regulation of several signaling pathways. Activation of either JAK-STAT3 or PI3K, the downstream cascade of gp130, can maintain the self-renewal of ES cells, while phosphorylation of another gp130-related branch, SHP2-Ras-ERK, drives the differentiation. BMP2/4-mediated signaling is capable of suppressing the differentiation of ES cells in collaboration with activated JAK-STAT3 under serum free culture conditions. Other signaling such as Wnt also contributes to the self-renewal of ES cells. Generally, the network, which is composed of various signaling pathways, modulates the self-renewal and differentiation of mouse ES cells precisely. This review focuses on the role of gp130 in proliferation of mouse ES cells including inhibitory effect of JAK-STAT3 pathway activation on differentiation of mouse ES cells, maintenance effect of PI3K pathway activation on self-renewal of ES cells, promotive effect of SHP-2-Ras-ERK pathway activation on differentiation of ES cells, and influence of other signaling pathways on self-renewal of mouse ES cells, including maintenance effect of BMP combination with LIF under serum free culture conditions on self-renewal of ES cells and promotive effect of Wnt pathway activation on self-renewal of ES cells.