Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece.
Warwickshire Institute for the Study of Diabetes, Endocrinology and Metabolism (WISDEM), University Hospitals Coventry and Warwickshire NHS Trust, Coventry CV2 2DX, UK.
Int J Mol Sci. 2021 Jan 15;22(2):818. doi: 10.3390/ijms22020818.
AIMS/HYPOTHESIS: SGLT-2 inhibitors (SGLT-2i) have been studied as potential treatments against NAFLD, showing varying beneficial effects. The molecular mechanisms mediating these effects have not been fully clarified. Herein, we investigated the impact of empagliflozin on NAFLD, focusing particularly on ER stress, autophagy and apoptosis.
Five-week old ApoE mice were switched from normal to a high-fat diet (HFD). After five weeks, mice were randomly allocated into a control group (HFD + vehicle) and Empa group (HFD + empagliflozin 10 mg/kg/day) for five weeks. At the end of treatment, histomorphometric analysis was performed in liver, mRNA levels of , , , , , , , , , , , , , , , , , , , , , and were measured by qRT-PCR, and protein levels of p-EIF2α, EIF2a, CHOP, LC3II, P62, BECLIN-1 and cleaved CASPASE-8 were assessed by immunoblotting.
Empagliflozin-treated mice exhibited reduced fasting glucose, total cholesterol and triglyceride serum levels, as well as decreased NAFLD activity score, decreased expression of lipogenic enzymes (, and ) and inflammatory molecules ( and ), compared to the Control group. Empagliflozin significantly decreased the expression of ER stress molecules , , , , , , , and ; whilst activating autophagy via increased AMPK phosphorylation, decreased and increased expression. Finally, empagliflozin increased the ratio and inhibited CASPASE-8 cleavage, reducing liver cell apoptosis. Immunoblotting analysis confirmed the qPCR results.
These novel findings indicate that empagliflozin treatment for five weeks attenuates NAFLD progression in ApoE mice by promoting autophagy, reducing ER stress and inhibiting hepatic apoptosis.
目的/假设：SGLT-2 抑制剂（SGLT-2i）已被研究作为治疗非酒精性脂肪性肝病（NAFLD）的潜在方法，显示出不同的有益作用。介导这些作用的分子机制尚未完全阐明。在此，我们研究了恩格列净对 NAFLD 的影响，特别关注内质网应激、自噬和细胞凋亡。
五周龄 ApoE 小鼠从正常饮食切换至高脂肪饮食（HFD）。五周后，将小鼠随机分为对照组（HFD + 载体）和 Empa 组（HFD + 恩格列净 10mg/kg/天），治疗五周。治疗结束时，对肝脏进行组织形态计量学分析，通过 qRT-PCR 测量 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 和 的 mRNA 水平，并通过免疫印迹评估 p-EIF2α、EIF2a、CHOP、LC3II、P62、BECLIN-1 和 cleaved CASPASE-8 的蛋白水平。
与对照组相比，恩格列净治疗组小鼠空腹血糖、总胆固醇和甘油三酯血清水平降低，NAFLD 活性评分降低，脂肪生成酶（ 、 和 ）和炎症分子（ 和 ）表达降低。恩格列净显著降低 ER 应激分子 、 、 、 、 、 、 和 的表达；同时通过增加 AMPK 磷酸化来激活自噬，减少 和增加 表达。最后，恩格列净增加了 比值并抑制了 CASPASE-8 切割，减少了肝实质细胞凋亡。免疫印迹分析证实了 qPCR 结果。
这些新发现表明，恩格列净治疗五周可通过促进自噬、减轻内质网应激和抑制肝实质细胞凋亡来减轻 ApoE 小鼠的 NAFLD 进展。
