Embryonic stem cell differentiation into smooth muscle cells is mediated by Nox4-produced H 2 O 2

作者：Qingzhong Xiao, Zhenling Luo, Anna Pepe, Andriani Margariti, Lingfang Zeng, Qingbo Xu · 发表于：American Journal of Physiology-Cell Physiology · 年份：2008 · DOI：10.1152/ajpcell.00442.2008 · 被引用次数：182 · 研究领域：Neutrophil, Myeloperoxidase and Oxidative Mechanisms、Nitric Oxide and Endothelin Effects、Angiogenesis and VEGF in Cancer

NADPH oxidase (Nox4) produces reactive oxygen species (ROS) that are important for vascular smooth muscle cell (SMC) behavior, but the potential impact of Nox4 in stem cell differentiation is unknown. When mouse embryonic stem (ES) cells were plated on collagen IV-coated dishes/flasks, a panel of SMC-specific genes was significantly and consistently upregulated. Nox4 expression was markedly correlated with such a gene induction as confirmed by real-time PCR, immunofluorescence, and Western blot analysis. Overexpression of Nox4 specifically resulted in increased SMC marker production, whereas knockdown of Nox4 induced a decrease. Furthermore, SMC-specific transcription factors, including serum response factor (SRF) and myocardin were activated by Nox4 gene expression. Moreover, Nox4 was demonstrated to drive SMC differentiation through generation of H(2)O(2). Confocal microscopy analysis indicates that SRF was translocated into the nucleus during SMC differentiation in which SRF was phosphorylated. Additionally, autosecreted transforming growth factor (TGF)-beta(1) activated Nox4 and promoted SMC differentiation. Interestingly, cell lines generated from stem cells by Nox4 transfection and G418 selection displayed a characteristic of mature SMCs, including expression of SMC markers and cells with contractile function. Thus we demonstrate for the first time that Nox4 is crucial for SMC differentiation from ES cells, and enforced Nox4 expression can maintain differentiation statu...