Background

Kidney damage often develops into renal fibrosis. Apoptosis and inflammatory response are the main factors driving the process of renal fibrosis. Here we showed that lncRNA XIST/ miR-19b / SOX6 signal axis regulated apoptosis and inflammation of renal fibrosis.

Methods

HK-2 cells were treated with TGF-β1 to construct cell fibrosis model, and UUO surgery was performed to construct mouse renal fibrosis model. The expression of XIST, miR-19b and SOX6 were examined by qPCR. And levels of fibrosis-related proteins were detected by western blotting. Levels of IL-1β and TNF-α were assessed by qPCR and ELISA, respectively. Renal pathology and fibrosis were evaluated by HE and Masson staining. Flow cytometry and TUNEL staining were employed to evaluate cell apoptosis in cell fibrosis model and mouse renal fibrosis model, respectively. Besides, dual luciferase reporter assay was employed to verify whether XIST had a binding site to miR-19b, and whether miR-19b had a binding site to SOX6.

Results

Here we showed that XIST and SOX6 were upregulated in both HK-2 cells treatment of TGF-β1 and kidneys of UUO mice, while miR-19b was downregulated. Dual luciferase reporter assay displayed that XIST directly bound to miR-19b, and SOX6 was the target of miR-19b. Knockdown of XIST inhibited apoptosis, inflammation and fibrosis in HK-2 cells treatment of TGF-β1 via miR-19b-mediated downregulation of SOX6, while inhibition of miR-19b reversed the effect. Similarly, knockdown of XIST in vivo inhibited apoptosis, inflammation and fibrosis in kidneys of UUO mice via miR-19b-mediated downregulation of SOX6.

Discussion

These results provided evidence that knockdown of XIST inhibited apoptosis and inflammation of renal fibrosis via miR-19b-mediated downregulation of SOX6.

中文翻译：

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敲低 lncRNA XIST 通过 microRNA-19b 介导的 SOX6 下调抑制肾纤维化中的细胞凋亡和炎症

背景

肾损伤常发展为肾纤维化。细胞凋亡和炎症反应是驱动肾纤维化过程的主要因素。在这里我们发现 lncRNA XIST/miR-19b/SOX6 信号轴调节肾纤维化的细胞凋亡和炎症。

方法

用TGF-β1处理HK-2细胞构建细胞纤维化模型，并进行UUO手术构建小鼠肾纤维化模型。通过qPCR检测XIST、miR-19b和SOX6的表达。并且通过蛋白质印迹检测纤维化相关蛋白的水平。分别通过 qPCR 和 ELISA 评估 IL-1β 和 TNF-α 的水平。通过 HE 和 Masson 染色评估肾脏病理和纤维化。流式细胞术和TUNEL染色分别用于评估细胞纤维化模型和小鼠肾纤维化模型中的细胞凋亡。此外，采用双荧光素酶报告基因检测来验证 XIST 是否具有与 miR-19b 的结合位点，以及 miR-19b 是否具有与 SOX6 的结合位点。

结果

在这里，我们发现 XIST 和 SOX6 在 TGF-β1 和 UUO 小鼠肾脏的 HK-2 细胞处理中上调，而 miR-19b 下调。双荧光素酶报告基因检测显示 XIST 直接与 miR-19b 结合，SOX6 是 miR-19b 的靶标。XIST 的敲低通过 miR-19b 介导的 SOX6 下调抑制了 HK-2 细胞处理 TGF-β1 的细胞凋亡、炎症和纤维化，而 miR-19b 的抑制则逆转了这种作用。同样，体内 XIST 的敲低通过 miR-19b 介导的 SOX6 下调抑制了 UUO 小鼠肾脏的细胞凋亡、炎症和纤维化。

讨论

这些结果提供的证据表明，XIST 的敲低通过 miR-19b 介导的 SOX6 下调抑制了肾纤维化的细胞凋亡和炎症。