钠-葡萄糖协同转运蛋白 2 抑制剂恩格列净下调微小 RNA-34a-5p 并靶向 GREM2 以抑制肝星状细胞活化并改善非酒精性脂肪性肝病相关纤维化。

SGLT2 inhibitor empagliflozin downregulates miRNA-34a-5p and targets GREM2 to inactivate hepatic stellate cells and ameliorate non-alcoholic fatty liver disease-associated fibrosis.

机构信息

Department of Endocrinology and Metabolism, the Second Affiliated Hospital of Nanchang University, Nanchang 330006, China; Branch of National Clinical Research Center for Metabolic Diseases, Nanchang 330006, China; Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, Nanchang 330006, China.

Department of Endocrinology and Metabolism, the Second Affiliated Hospital of Nanchang University, Nanchang 330006, China; Guangdong Provincial Key Laboratory of Diabetology, Guangzhou 510630, China; Department of Endocrinology and Metabolism, Jiujiang University Affiliated Hospital, Jiujiang 330300, China.

出版信息

Metabolism. 2023 Sep;146:155657. doi: 10.1016/j.metabol.2023.155657. Epub 2023 Jul 6.

DOI:10.1016/j.metabol.2023.155657

PMID:37422021

Abstract

BACKGROUND AND RATIONALE

Activation of hepatic stellate cells (HSCs), the central event of fibrosis, indicates the severe stage of non-alcoholic fatty liver disease (NAFLD). MicroRNAs (miRNAs) participate in this process. Treatment with a sodium-glucose cotransporter 2 inhibitor (SGLT2i) alleviates liver fibrosis in patients with type 2 diabetes and NAFLD; however, the role of SGLT2i in ameliorating liver fibrosis in NAFLD by regulating miRNAs remains unclear.

APPROACH AND RESULTS

We monitored the expression of NAFLD-associated miRNAs in the livers of two NAFLD models and observed high expression of miR-34a-5p. miR-34a-5p was highly expressed in mouse primary liver non-parenchymal cells and LX-2 HSCs, and this miRNA was positively correlated with alanine transaminase levels in NAFLD models. Overexpression of miR-34a-5p enhanced LX-2 activation, whereas its inhibition prevented HSCs activation by regulating the TGFβ signaling pathway. The SGLT2i empagliflozin significantly downregulated miR-34a-5p, inhibited the TGFβ signaling pathway, and ameliorated hepatic fibrosis in NAFLD models. Subsequently, GREM2 was identified as a direct target of miR-34a-5p through database prediction and a dual-luciferase reporter assay. In LX-2 HSCs, the miR-34a-5p mimic and inhibitor directly downregulated and upregulated GREM2, respectively. Overexpressing GREM2 inactivated the TGFβ pathway whereas GREM2 knockdown activated it. Additionally, empagliflozin upregulated Grem2 expression in NAFLD models. In methionine- and choline-deficient diet-fed ob/ob mice, a fibrosis model, empagliflozin downregulated miR-34a-5p and upregulated Grem2 to improve liver fibrosis.

CONCLUSIONS

Empagliflozin ameliorates NAFLD-associated fibrosis by downregulating miR-34a-5p and targeting GREM2 to inhibit the TGFβ pathway in HSCs.

摘要

背景和原理

肝星状细胞（HSCs）的激活是纤维化的核心事件，表明非酒精性脂肪性肝病（NAFLD）处于严重阶段。微小 RNA（miRNA）参与了这一过程。钠-葡萄糖共转运蛋白 2 抑制剂（SGLT2i）可减轻 2 型糖尿病和 NAFLD 患者的肝纤维化；然而，SGLT2i 通过调节 miRNA 改善 NAFLD 肝纤维化的作用尚不清楚。

方法和结果

我们监测了两种 NAFLD 模型肝脏中与 NAFLD 相关的 miRNA 的表达情况，观察到 miR-34a-5p 的高表达。miR-34a-5p 在小鼠原代肝非实质细胞和 LX-2 HSCs 中高表达，并且该 miRNA 与 NAFLD 模型中的丙氨酸转氨酶水平呈正相关。miR-34a-5p 的过表达增强了 LX-2 的激活，而其抑制通过调节 TGFβ 信号通路防止 HSCs 的激活。SGLT2i 恩格列净显著下调 miR-34a-5p，抑制 TGFβ 信号通路，并改善 NAFLD 模型中的肝纤维化。随后，通过数据库预测和双荧光素酶报告基因检测鉴定 GREM2 为 miR-34a-5p 的直接靶标。在 LX-2 HSCs 中，miR-34a-5p 模拟物和抑制剂分别直接下调和上调 GREM2。过表达 GREM2 可使 TGFβ 通路失活，而 GREM2 敲低则使其激活。此外，恩格列净在 NAFLD 模型中上调 Grem2 的表达。在蛋氨酸和胆碱缺乏饮食喂养的 ob/ob 小鼠（纤维化模型）中，恩格列净下调 miR-34a-5p 并上调 Grem2 以改善肝纤维化。