沉默 miR-21 通过靶向 ERK1/2 信号通路抑制小鼠肾间质纤维化。

Silenced miR-21 inhibits renal interstitial fibrosis via targeting ERK1/2 signaling pathway in mice.

机构信息

Department of Nephrology, The First Affiliated Hospital of Jinan University, Guangzhou, China.

出版信息

Eur Rev Med Pharmacol Sci. 2019 Aug;23(3 Suppl):110-116. doi: 10.26355/eurrev_201908_18637.

DOI:10.26355/eurrev_201908_18637

PMID:31389582

Abstract

OBJECTIVE

To study the influence of micro ribonucleic acid (miR)-21 on the renal interstitial fibrosis (RIF) model mice, and to preliminarily elucidate the mechanism of action of miR-21 in the development of RIF by studying the influences of miR-21 on the expressions of the proteins related to the extracellular signal-regulated kinase (ERK) 1/2 signaling pathway and its downstream proteins.

MATERIALS AND METHODS

The mouse model of the left unilateral ureteral obstruction (UUO) was established. The experimental mice were divided into the Sham group and UUO group and were normally fed for 3 weeks. Then, they were executed, and their blood was extracted to determine the renal function-related indicators. The left kidney was excised, and the corresponding specimens were reserved for observing the appearance of the kidney and the morphology of the renal tubules and interstitium. The relative expression levels of epithelial (E-)cadherin, α-smooth muscle actin (α-SMA), and ERK1/2 phosphorylated ERK1/2 (p-ERK1/2), the transforming growth factor-β1 (TGF-β1) and the connective tissue growth factor (CTGF) proteins in renal tissues were determined. After the human renal proximal tubular epithelial cell line, the human kidney-2 (HK-2) was treated with high glucose (HG) combined with silenced miR-21 or the ERK1/2 inhibitor PD98059, the relative expression levels of ɑ-SMA and TGF-β1 protein were measured.

RESULTS

UUO group had significantly higher content of blood urea nitrogen (BUN), serum creatinine (SCr), and uric acid (UA) than the Sham group, and exhibited the infiltration of renal interstitial monocytes and lymphocytes, renal tubular podocyte damage, phenotypic transformation and atrophy, the activation and proliferation of interstitial fibroblasts, and excessive deposition of extracellular matrix (ECM). Moreover, the expression level of E-cadherin in the renal tissues was decreased, but the relative expression levels of ɑ-SMA, and TGF-β1, CTGF, and p-ERK1/2 proteins were evidently elevated. Lower relative expression levels of ɑ-SMA and TGF-β1 protein were detected in the human renal proximal tubular epithelial cell line HK-2 after the combined treatment with HG and silenced miR-21 or the ERK1/2 inhibitor PD98059.

CONCLUSIONS

MiR-21 may be related to the occurrence and development of RIF. Silenced miR-21 probably suppresses RIF via the ERK1/2 signaling pathway.

摘要

目的

研究微小 RNA-21（miR-21）对肾间质纤维化（RIF）模型小鼠的影响，并通过研究 miR-21 对细胞外信号调节激酶（ERK）1/2 信号通路相关蛋白及其下游蛋白表达的影响，初步阐明 miR-21 在 RIF 发生发展中的作用机制。

材料和方法

建立单侧输尿管梗阻（UUO）小鼠模型。将实验小鼠分为假手术组和 UUO 组，正常饲养 3 周后处死，提取血液检测肾功能相关指标，切取左肾，保留相应标本观察肾脏外观及肾小管和肾间质形态学变化，检测肾组织上皮（E-）钙黏蛋白、α-平滑肌肌动蛋白（α-SMA）和 ERK1/2 磷酸化 ERK1/2（p-ERK1/2）、转化生长因子-β1（TGF-β1）和结缔组织生长因子（CTGF）蛋白的相对表达水平。用高糖（HG）联合沉默 miR-21 或 ERK1/2 抑制剂 PD98059 处理人肾近端管状上皮细胞系 HK-2 后，检测 α-SMA 和 TGF-β1 蛋白的相对表达水平。

结果

UUO 组血尿素氮（BUN）、血清肌酐（SCr）和尿酸（UA）含量明显高于假手术组，出现肾间质单核细胞和淋巴细胞浸润、肾小管足细胞损伤、表型转化和萎缩、间质成纤维细胞激活和增殖、细胞外基质（ECM）过度沉积；肾组织 E-钙黏蛋白表达水平降低，α-SMA 及 TGF-β1、CTGF、p-ERK1/2 蛋白相对表达水平明显升高；HG 联合沉默 miR-21 或 ERK1/2 抑制剂 PD98059 处理后，人肾近端管状上皮细胞系 HK-2 中 α-SMA 和 TGF-β1 蛋白的相对表达水平降低。