Men Tong, Piao Shan-Hua, Teng Chun-Bo
Laboratory of Animal Developmental Biology, College of Life Sciences, Northeast Forestry University, Harbin 150040, China.
Yi Chuan. 2013 Nov;35(11):1283-90. doi: 10.3724/sp.j.1005.2013.01283.
Mesenchymal stem cells (MSCs) are pluripotent cells which can differentiate into several distinct lineages, such as chondrocytes, adipocytes and myofibers. It has been reported that the lineage-specific transcriptional factors including Runt related transcription factor 2 (RUNX2), Peroxisome proliferator-activator receptor gamma (PPARgamma) and Myogenic differentiation 1 (MyoD) may play key regulatory roles among the differentiation of MSCs. Recently, researches have confirmed that the Hippo pathway impacts the differentiation fates of MSCs through regulating the activity of line- age-specific transcription factors by the Hippo pathway effectors Tafazzin (TAZ) and/or Yes-associated protein (YAP). The interaction between TAZ and RUNX2 boosts the osteogenic processes and promotes MSCs differentiating into osteoblast lineage. However, PPARgamma binding to TAZ may inhibit the adipocytes differentiation, and thus overexpression of TAZ in mesenchymal stem cell-like cells increases the expression of myogenic genes and hastens myofiber formation through a MyoD-dependent manner. Moreover, other signaling pathways (such as BMP-2, TNF-alpha, Eph-Ephrin, etc.), small molecules (KR62980, TM-25659, etc.), and mechanistic stimuli can also affect the fate by regulating the activity of TAZ/YAP. In this review, we summarized the signaling pattern of Hippo pathway and the function mechanism of TAZ and/or YAP by enumerating their interaction to several lineage-specific transcriptional factors and relationship with other signal pathways during MSCs differentiation.
间充质干细胞(MSCs)是多能细胞,可分化为几种不同的谱系,如软骨细胞、脂肪细胞和肌纤维。据报道,包括Runx相关转录因子2(RUNX2)、过氧化物酶体增殖物激活受体γ(PPARγ)和成肌分化1(MyoD)在内的谱系特异性转录因子可能在MSCs的分化中起关键调节作用。最近,研究证实Hippo信号通路通过Hippo信号通路效应器塔法兹蛋白(TAZ)和/或Yes相关蛋白(YAP)调节谱系特异性转录因子的活性,从而影响MSCs的分化命运。TAZ与RUNX2之间的相互作用促进成骨过程,并促进MSCs分化为成骨细胞谱系。然而,PPARγ与TAZ结合可能会抑制脂肪细胞分化,因此在间充质干细胞样细胞中过表达TAZ会通过依赖MyoD的方式增加成肌基因的表达并加速肌纤维形成。此外,其他信号通路(如BMP-2、TNF-α、Eph-Ephrin等)、小分子(KR62980、TM-25659等)和机械刺激也可通过调节TAZ/YAP的活性来影响细胞命运。在本综述中,我们通过列举TAZ和/或YAP与几种谱系特异性转录因子的相互作用以及它们在MSCs分化过程中与其他信号通路的关系,总结了Hippo信号通路的信号模式以及TAZ和/或YAP的功能机制。