Stem cell-derived Sca-1+ progenitors differentiate into smooth muscle cells, which is mediated by collagen IV-integrin α1/β1/αv and PDGF receptor pathways
Stem cell-derived Sca-1+ progenitors differentiate into smooth muscle cells, which is mediated by collagen IV-integrin α1/β1/αv and PDGF receptor pathways
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DOI：
10.1152/ajpcell.00341.2006
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发表时间：
2007-01-01
影响因子：
5.5
通讯作者：
Xu, Qingbo
中科院分区：
文献类型：
--
作者：
Xiao, Qingzhong;Zeng, Lingfang;Xu, Qingbo
胚胎干细胞（ES）可以分化为平滑肌细胞（SMC），可用于组织工程和修复受损器官。然而，对这些细胞分化的分子机制知之甚少。在本研究中，我们发现IV型胶原可以促进ES细胞分化为干细胞抗原1阳性（Sca-1（+））祖细胞和平滑肌细胞。用抗IV型胶原抗体预处理ES细胞可显著抑制SMC标志物的表达。为了进一步阐明IV型胶原对SMC分化的诱导和维持的作用，用磁珠分离Sca-1（+）祖细胞，置于IV型胶原包被的烧瓶中，并在含有或不含血小板衍生生长因子（PDGF）-BB的分化培养基中培养6 - 90天。免疫染色和荧光激活细胞分选仪分析显示，这些细胞中的大多数是阳性的SMC特异性标志物。用抗整合素α（1）、α（v）和β（1）的抗体预处理Sca-1（+）祖细胞，但不能抑制β（3），抑制粘着斑激酶（FAK）和桩蛋白磷酸化，并导致SMC分化的显著抑制。各种酪氨酸激酶抑制剂和磷脂酰肌醇3-激酶（PI 3-激酶）和PDGF受体β的特异性siRNA显著抑制SMC标志物表达。综上所述，我们首次证明了IV型胶原在SMC分化的早期阶段起着至关重要的作用，并且整合素（α（1）、β（1）和α（v））-FAK-PI 3-激酶-丝裂原活化蛋白激酶和PDGF受体-β信号通路参与SMC分化。
Embryonic stem (ES) cells can differentiate into smooth muscle cells (SMCs) that can be used for tissue engineering and repair of damaged organs. However, little is known about the molecular mechanisms of differentiation in these cells. In the present study, we found collagen IV can promote ES cells to differentiate into stem cell antigen-1-positive (Sca-1(+)) progenitor cells and SMCs. Pretreatment of ES cells with antibodies against collagen IV significantly inhibited SMC marker expression. To further elucidate the effect of collagen IV on the induction and maintenance of SMC differentiation, Sca-1(+) progenitor cells were isolated with magnetic beads, placed in collagen-IV-coated flasks, and cultured in differentiation medium with or without platelet-derived growth factor ( PDGF)-BB for 6 - 90 days. Both immunostaining and fluorescence-activated cell sorter analyses revealed that the majority of these cells were positive for SMC-specific markers. Pretreatment of Sca-1(+) progenitors with antibodies against integrin alpha(1), alpha(v), and beta(1), but not beta(3), inhibited focal adhesion kinase (FAK) and paxillin phosphorylation and resulted in a marked inhibition of SMC differentiation. Various tyrosine kinase inhibitors, and specific siRNA for phosphatidylinositol 3-kinase (PI 3-kinase) and PDGF receptor-beta significantly inhibited SMC marker expression. Taken together, we demonstrate for the first time that collagen IV plays a crucial role in the early stage of SMC differentiation and that integrin (alpha(1), beta(1), and alpha(v))-FAK-PI 3-kinase-mitogen-activated protein kinase and PDGF receptor-beta signaling pathways are involved in SMC differentiation.