HuR mediates motility of human bone marrow-derived mesenchymal stem cells triggered by sphingosine 1-phosphate in liver fibrosis
HuR mediates motility of human bone marrow-derived mesenchymal stem cells triggered by sphingosine 1-phosphate in liver fibrosis
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DOI：
10.1007/s00109-016-1460-x
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发表时间：
2017-01-01
影响因子：
4.7
通讯作者：
Li, Liying
中科院分区：
文献类型：
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作者：
Chang, Na;Ge, Jingjing;Li, Liying
1-磷酸鞘氨醇 (SIP) 在小鼠肝纤维化过程中通过上调 SIP 受体 3 (S1PR3) 参与骨髓 (BM) 来源的间充质干细胞 (BMSC) 向受损肝脏的迁移。但是，其分子机制仍不清楚。 HuR 作为一种 RNA 结合蛋白，调节肿瘤细胞运动。在这里，我们研究了 HuR 在肝纤维化中人 BMSC (hBMSC) 迁移中的作用。结果显示，人类或小鼠纤维化肝脏中 HuR 信使 RNA (mRNA) 水平升高，并与 S1PR3 mRNA 表达相关。利用免疫荧光法，我们发现HuR主要定位于正常肝脏的肝细胞核和非实质细胞。然而，在纤维化肝脏中，我们检测到非实质细胞中 HuR 细胞质定位增加。在 EGFP 标记的 BM 细胞嵌合小鼠中，纤维化区域中有大量 EGFP 阳性细胞（BM 来源）呈 HuR 阳性。同时，HuR 阳性细胞的 cx-SMA（肌成纤维细胞）也呈阳性。在体外，SIP 通过上调 S1PR3 诱导 hBMSC 迁移。 HuR 参与 S1P 诱导的 hBMSC 迁移，并通过与 miR-30e 竞争增加 S1PR3 mRNA 的稳定性。 RNA免疫沉淀显示与S1PR3 mRNA 3rUTR相互作用。此外，SIP 通过 S1PR3 和 p38MAPK 导致 HuR 磷酸化和细胞质易位。此外，我们将含有或不含HuR小干扰RNA（siRNA）的EGFP（+）BMSC移植到四氯化碳处理的小鼠体内，通过体内流式细胞术分析发现HuR的敲低抑制了BMSC向受损肝脏的迁移。我们发现 HuR 和 S1PR3 之间在 SIP 诱导的 BMSC 迁移中存在正反馈调节机制。 HuR 参与 SIP 诱导的 S1PR3 上调。 SlP 通过 S1PR3 导致 HuR 磷酸化和易位。我们的研究结果为肝纤维化的机制提供了一种新的调控方式。
Sphingosine 1-phosphate (SIP) participates in migration of bone marrow (BM)-derived mesenchymal stem cells (BMSCs) toward damaged liver via upregulation of SIP receptor 3 (S1PR3) during mouse liver fibrogenesis. But, the molecular mechanism is still unclear. HuR, as an RNA-binding protein, regulates tumor cell motility. Here, we examined the role of HuR in migration of human BMSCs (hBMSCs) in liver fibrosis. Results showed that HuR messenger RNA (mRNA) level was increased in human or mouse fibrotic livers, and correlated with S1PR3 mRNA expression. Using immunotlitorescence, we found that HuR mainly localized in the nuclei of hepatocytes and non-parenchymal cells in normal livers. However, in fibrotic livers, we detected an increased HuR cytoplasmic localization in non-parenchymal cells. In chimeric mice of BM cell-labeled by EGFP, significant numbers of EGFP-positive cells (BM origin) were positive for HuR in fibrotic areas. Meanwhile, HuR-positive cells were also positive for cx-SMA (myofibroblasts). In vitro, SIP induced hBMSCs migration via S1PR3 upregulation. HuR involved in S1P-induced hBMSCs migration and increased stabilization of S1PR3 mRNA via competing with miR-30e. RNA immunoprecipitation showed that interacted with S1PR3 mRNA 3rUTR. Moreover, SIP resulted in phosphorylation and cytoplasmic translocation of HuR via S1PR3 and p38MAPK. Furthermore, we transplanted EGFP(+) BMSCs with or without HuR small interfering RNA (siRNA) into carbon tetrachloride-treated mice and found that knockdown of HuR inhibited the migration of BMSCs toward injured livers by flow cytometric analysis in vivo. We identified a positive feedback regulation mechanism between HuR and S1PR3 in SIP induced BMSCs migration. HuR participates in upregulation of S1PR3 induced by SIP. SlP results in phosphorylation and translocation of HuR via S1PR3. Our results provide a new regulatory manner to the mechanism of liver fibrogenesis.