MEK/ERK and p38 MAPK regulate chondrogenesis of rat bone marrow mesenchymal stem cells through delicate interaction with TGF-β1/Smads pathway
MEK/ERK and p38 MAPK regulate chondrogenesis of rat bone marrow mesenchymal stem cells through delicate interaction with TGF-β1/Smads pathway
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DOI：
10.1111/j.1365-2184.2010.00682.x
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发表时间：
2010-08-01
影响因子：
8.5
通讯作者：
Liu, Y.
中科院分区：
文献类型：
--
作者：
Li, J.;Zhao, Z.;Liu, Y.
目的：探讨MEK/ERK和p38信号通路在大鼠骨髓间充质干细胞（BMSCs）向软骨细胞分化中的作用及机制，并进一步探讨丝裂原活化蛋白激酶（MAPK）和转化生长因子-β 1（TGF-β 1）/Smads信号通路在BMSCs向软骨细胞分化过程中的相互作用。Western Blot分析ERK 1/2和p38激酶活性。应用特异性MAPK抑制剂PD 98059和SB 20350研究MEK/ERK和p38信号对软骨细胞特异性标志物基因表达的调控作用，以及TGF-β 1下游Smad 2/3通路的调控作用。这两种MAPK亚型在介导Col 2 α和聚集蛋白聚糖的软骨特异性基因的转录中发挥相反的作用。TGF-β 1刺激的软骨形成调节因子Sox 9、Runx 2和Ihh的基因表达也受到PD 98059和SB 203580活性的不同程度的影响。然而，MAPK抑制剂对基因表达的影响相对较小，当不与TGF-β 1处理。此外，Smad 2/3的基因转录显着上调TGF-β 1，但调节更微妙的治疗与MAPK inhibitors.Conclusions：MAPK亚型似乎调节软骨形成与微妙的平衡，相互作用与TGF-β 1/Smads信号通路。
Objectives:This study was carried out to reveal functions and mechanisms of MEK/ERK and p38 pathways in chondrogenesis of rat bone marrow mesenchymal stem cells (BMSCs), and to investigate further any interactions between the mitogen-activated protein kinase (MAPK) and transforming growth factor-beta 1 (TGF-beta 1)/Smads pathway in the process.Materials and methods:Chondrogenic differentiation of rat BMSCs was initiated in micromass culture, in the presence of TGF-beta 1, for 2 weeks. ERK1/2 and p38 kinase activities were investigated by Western Blot analysis. Specific MAPK inhibitors PD98059 and SB20350 were employed to investigate regulatory effects of MEK/ERK and p38 signals on gene expression of chondrocyte-specific markers, and TGF-beta 1 downstream pathways of Smad2/3.Results:ERK1/2 was phosphorylated in a rapid but transient manner, whereas p38 was activated in a slow and sustained way. The two MAPK subtypes played opposing roles in mediating transcription of cartilage-specific genes for Col2 alpha and aggrecan. TGF-beta 1-stimulated gene expression of chondrogenic regulators, Sox9, Runx2 and Ihh, was also affected by activity of PD98059 and SB203580, to different degrees. However, influences of MAPK inhibitors on gene expression were relatively minor when not treated with TGF-beta 1. In addition, gene transcription of Smad2/3 was significantly upregulated by TGF-beta 1, but was regulated more subtly by treatment with MAPK inhibitors.Conclusions:MAPK subtypes seemed to regulate chondrogenesis with a delicate balance, interacting with the TGF-beta 1/Smads signalling pathway.