Transforming growth factor--sphingosine kinase 1/S1P signaling upregulates microRNA-21 to promote fibrosis in renal tubular epithelial cells
Transforming growth factor--sphingosine kinase 1/S1P signaling upregulates microRNA-21 to promote fibrosis in renal tubular epithelial cells
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DOI：
10.1177/1535370215605586
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发表时间：
2016-02-01
影响因子：
3.2
通讯作者：
Xu, Lihong
中科院分区：
文献类型：
--
作者：
Liu, Xiujuan;Hong, Quan;Xu, Lihong
肾纤维化是以肾小管上皮细胞凋亡、肾小管间质成纤维细胞增生和细胞外基质（ECM）过度沉积为特征的进行性病理改变。miR-21与转化生长因子（TGF-）刺激的组织纤维化有关。最近的研究表明，鞘氨醇激酶/鞘氨醇-1-磷酸（SphK/S1 P）也是TGF-刺激的组织纤维化的关键;然而，目前尚不清楚SphK/S1 P是否与miR-21相互作用。在这项研究中，我们假设SphK/S1 P信号转导与TGF-β上调miR-21有关。为了验证这一假设，我们首先通过使用qRT-PCR和北方印迹法确定miR-21在TGF-β刺激的肾小管上皮细胞（TEC）中高表达。同时，抑制miR-21，介导的相应antiir，显着降低的表达和沉积的I型胶原，纤连蛋白（Fn），富含半胱氨酸的蛋白61（CCN 1），平滑肌肌动蛋白，和成纤维细胞特异性蛋白1在TGF-处理的TEC。ELISA和qRT-PCR检测TEC中S1 P和SphK 1的水平。TGF-β通过激活SphK 1诱导S1 P产生。此外，观察到TGF-β刺激的miR-21上调被SphK 1 siRNA消除，并通过添加外源性S1 P恢复。阻断S1 PR（2）也抑制了miR-21的上调。此外，miR-21过表达减弱了SphK 1和S1 PR（2）siRNA对TGF-刺激的ECM沉积和上皮-间质转化的抑制。总之，我们的研究证明了SphK 1/S1 P和TGF-诱导的miR-21在肾TEC中的联系，并可能代表肾纤维化的新治疗靶点。
Renal fibrosis is a progressive pathological change characterized by tubular cell apoptosis, tubulointerstitial fibroblast proliferation, and excessive deposition of extracellular matrix (ECM). miR-21 has been implicated in transforming growth factor- (TGF-)-stimulated tissue fibrosis. Recent studies showed that sphingosine kinase/sphingosine-1-phosphate (SphK/S1P) are also critical for TGF--stimulated tissue fibrosis; however, it is not clear whether SphK/S1P interacts with miR-21 or not. In this study, we hypothesized that SphK/S1P signaling is linked to upregulation of miR-21 by TGF-. To verify this hypothesis, we first determined that miR-21 was highly expressed in renal tubular epithelial cells (TECs) stimulated with TGF- by using qRT-PCR and Northern blotting. Simultaneously, inhibition of miR-21, mediated by the corresponding antimir, markedly decreased the expression and deposition of type I collagen, fibronectin (Fn), cysteine-rich protein 61 (CCN1), -smooth muscle actin, and fibroblast-specific protein1 in TGF--treated TECs. ELISA and qRT-PCR were used to measure the S1P and SphK1 levels in TECs. S1P production was induced by TGF- through activation of SphK1. Furthermore, it was observed that TGF--stimulated upregulation of miR-21 was abolished by SphK1 siRNA and was restored by the addition of exogenous S1P. Blocking S1PR(2) also inhibited upregulation of miR-21. Additionally, miR-21 overexpression attenuated the repression of TGF--stimulated ECM deposition and epithelial-mesenchymal transition by SphK1 and S1PR(2) siRNA. In summary, our study demonstrates a link between SphK1/S1P and TGF--induced miR-21 in renal TECs and may represent a novel therapeutic target in renal fibrosis.