Urology Institute of Capital Medical University, Department of Urology, Capital Medical University Beijing Chaoyang Hospital, Beijing 100020, P.R. China.
Mol Med Rep. 2019 May;19(5):3696-3706. doi: 10.3892/mmr.2019.10045. Epub 2019 Mar 15.
Epithelial‑mesenchymal transition (EMT) has been demonstrated to serve a crucial role in the progression of interstitial fibrosis, which is one of the principal pathological features of chronic allograft nephropathy (CAN). However, to the best of our knowledge, the mechanisms of EMT in CAN have not been investigated. In the present study, the effect of stromal cell‑derived factor 1 (SDF‑1) and the Wnt signaling pathway on the progression of EMT following kidney transplantation was investigated. The CAN model was established using Fisher 344 and Lewis rats, treated with low‑dose cyclosporine with or without AMD3100. CAN was confirmed by the pathological alterations and chronic allograft damage index scoring, and EMT was confirmed by western blotting and reverse transcription‑quantitative polymerase chain reaction. In the AMD3100 group, there were lower expression levels of α‑SMA and higher expression levels of E‑cadherin, which indicated that CAN and EMT were ameliorated by AMD3100. The kidney tissue was analyzed using an mRNA + long noncoding (lnc)RNA microarray. A total of 506 mRNAs and 404 lncRNAs were demonstrated to be significantly differentially expressed between the two groups, which revealed the involvement of SDF‑1/CXC chemokine receptor 4 (CXCR4) and the Wnt pathway. SDF‑1 was demonstrated to induce EMT in vitro through the upregulation of α‑SMA, downregulation of E‑cadherin and the wound healing assay, and in the rat renal tubular epithelial cells via the nuclear accumulation of β‑catenin, which were all inhibited by either AMD3100 or DKK‑1. CXXC finger protein 5 (CXXC5), a negative regulator of the Wnt pathway, was downregulated following treatment with SDF‑1, which was inhibited by AMD3100 but not by DKK‑1. Thus, CXXC5 may be a regulator downstream of SDF‑1/CXCR4 in EMT. In conclusion, SDF‑1/CXCR4 induces EMT of renal tubular epithelial cells with the involvement of the Wnt pathway, which may be a novel mechanism and therapeutic target in kidney allograft fibrosis of rats.
上皮-间充质转化 (EMT) 已被证明在间质纤维化的进展中起关键作用，而间质纤维化是慢性移植肾肾病 (CAN) 的主要病理特征之一。然而，据我们所知，CAN 中 EMT 的机制尚未得到研究。本研究探讨了基质细胞衍生因子 1 (SDF-1) 和 Wnt 信号通路对肾移植后 EMT 进展的影响。采用 Fisher 344 和 Lewis 大鼠建立 CAN 模型，并用低剂量环孢素联合或不联合 AMD3100 进行治疗。通过病理改变和慢性移植物损伤指数评分证实 CAN，通过 Western blot 和逆转录-定量聚合酶链反应证实 EMT。在 AMD3100 组中，α-SMA 的表达水平降低，E-钙黏蛋白的表达水平升高，这表明 AMD3100 改善了 CAN 和 EMT。通过 mRNA+长非编码 (lnc)RNA 微阵列分析肾脏组织。两组间共鉴定出 506 个 mRNAs 和 404 个 lncRNAs 显著差异表达，揭示了 SDF-1/CXC 趋化因子受体 4 (CXCR4) 和 Wnt 通路的参与。SDF-1 被证明可通过上调α-SMA、下调 E-钙黏蛋白和伤口愈合试验，在体外诱导 EMT，并通过核β-连环蛋白的积累，在大鼠肾小管上皮细胞中诱导 EMT，这些作用均被 AMD3100 或 DKK-1 抑制。CXXC 手指蛋白 5 (CXXC5) 是 Wnt 通路的负调节剂，在 SDF-1 处理后下调，被 AMD3100 抑制，但不被 DKK-1 抑制。因此，CXXC5 可能是 SDF-1/CXCR4 在 EMT 中的下游调节因子。总之，SDF-1/CXCR4 诱导肾小管上皮细胞 EMT，涉及 Wnt 通路，这可能是大鼠肾移植纤维化的一种新的机制和治疗靶点。
