Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou, P.R. China.
Department of Nephrology, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, P.R. China.
J Cell Biochem. 2018 Apr;119(4):3149-3161. doi: 10.1002/jcb.26466. Epub 2018 Jan 2.
This study aims to explore whether microRNA-381 (miR-381) mediating CXCR4 affects the renal tubular epithelial cells (RTEC) of renal ischemia reperfusion (I/R) injury. Forty-eight rats were assigned into the I/R (n = 24, successfully established as I/R model) and sham (n = 24) groups. After collecting kidney tissues, immunohistochemistry, and microvascular density (MVD) counting were conducted for CXCR4 positive expression and MVD numbers. RTECs were assigned into the sham, blank, negative control (NC), miR-381 mimics, miR-381 inhibitor, si-CXCR4, and miR-381 inhibitor + si-CXCR4 groups. RT-qPCR and Western blotting were performed for relative expressions in tissues and cells. Cell proliferation and apoptosis were measured by MTT assay and flow cytometry. Results showed that compared with the sham group, positive expression of CXCR4 and MVD number were higher in the I/R group, which exhibited decreased miR-381 and increased expression of CXCR4, stromal cell-derived factor-1 (SDF1), vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1 (HIF-1α) and Tie-2. Dual luciferase reporter gene assay verified that CXCR4 is a target gene of miR-381. MiR-381 expression was lower in the miR-381 inhibitor + si-CXCR4 and miR-381 inhibitor groups and higher in the miR-381 mimics group than the blank and NC groups. Compared with the blank and NC groups, the miR-381 mimics and si-CXCR4 groups exhibited higher cell proliferation but lower cell apoptosis and expression of CXCR4, SDF1, VEGF, HIF-1α, and Tie-2, whereas the miR-381 inhibitor group exhibited the opposite trend. In conclusion, miR-381 may promote RTEC proliferation in rats with renal I/R injury by down-regulating CXCR4.
本研究旨在探讨微小 RNA-381(miR-381)介导的趋化因子受体 4(CXCR4)是否影响肾缺血再灌注(I/R)损伤的肾小管上皮细胞(RTEC)。将 48 只大鼠分为 I/R 组(n=24,成功建立 I/R 模型)和假手术组(n=24)。收集肾脏组织后,进行免疫组织化学和微血管密度(MVD)计数,以检测 CXCR4 阳性表达和 MVD 数量。将 RTEC 分为假手术组、空白组、阴性对照组(NC)、miR-381 模拟物组、miR-381 抑制剂组、si-CXCR4 组和 miR-381 抑制剂+si-CXCR4 组。采用 RT-qPCR 和 Western blot 检测组织和细胞中的相对表达水平。通过 MTT 检测和流式细胞术检测细胞增殖和凋亡。结果显示,与假手术组相比,I/R 组 CXCR4 阳性表达和 MVD 数量较高,miR-381 表达降低,CXCR4、基质细胞衍生因子 1(SDF1)、血管内皮生长因子(VEGF)、缺氧诱导因子 1(HIF-1α)和 Tie-2 表达增加。双荧光素酶报告基因实验验证 CXCR4 是 miR-381 的靶基因。miR-381 抑制剂+si-CXCR4 组和 miR-381 抑制剂组的 miR-381 表达低于空白组和 NC 组,miR-381 模拟物组的 miR-381 表达高于空白组和 NC 组。与空白组和 NC 组相比,miR-381 模拟物组和 si-CXCR4 组的细胞增殖率较高,细胞凋亡率和 CXCR4、SDF1、VEGF、HIF-1α、Tie-2 表达水平较低,而 miR-381 抑制剂组的细胞增殖率较低,细胞凋亡率和 CXCR4、SDF1、VEGF、HIF-1α、Tie-2 表达水平较高。综上所述,miR-381 可能通过下调 CXCR4 促进肾 I/R 损伤大鼠 RTEC 的增殖。