Department of Endocrinology and Metabolism, The Third Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong, China.
Department of Endocrinology and Metabolism, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong, China.
J Diabetes Res. 2020 Mar 19;2020:6894684. doi: 10.1155/2020/6894684. eCollection 2020.
Type 2 diabetes mellitus (T2DM) is featured by insulin resistance and lipid metabolism dysregulation. A large number of miRNAs were identified in exosomes derived from adipose tissue macrophages associated with T2DM pathogenesis, but its pathogenic roles remain unknown. This study is aimed at investigating the function of miR-210 in diabetic obesity.
Exosomes from mouse macrophage RAW264.7 cells were characterized by electron microscopy, combined with biomarker expression by western blot. Expression of miR-210 was determined by quantitative RT-PCR. Glucose uptake was measured by a fluorometric method, and the mitochondrial respiratory chain activity was evaluated by ELISA. The target gene of miR-210 was validated by dual-luciferase reporter and pull-down assays. A mouse obese diabetic model was established by a high-fat diet and streptozocin treatment.
miR-210 was highly expressed in exosomes derived from high glucose-induced macrophage RAW264.7 cells. Macrophage-derived exosomes impaired glucose uptake and mitochondrial CIV complex activity and suppressed NADH dehydrogenase ubiquinone 1 alpha subcomplex 4 (NDUFA4) expression in 3T3-L1 adipocytes. miR-210 directly bind with mRNA sequences of NDUFA4 gene. Inhibition of miR-210 mitigated the effects of macrophage-derived exosomes on the glucose uptake and complex IV (CIV) activity in 3T3-L1 adipocytes, and NDUFA4 overexpression offset the inhibition of glucose uptake and CIV activity by macrophage-derived exosomes. Furthermore, mice with miR-210 knockout showed greatly repressed diabetic obesity development.
miR-210 derived from adipose tissue macrophages promotes mouse obese diabetes pathogenesis by regulating glucose uptake and mitochondrial CIV activity through targeting NDUFA4 gene expression.
2 型糖尿病（T2DM）的特征是胰岛素抵抗和脂质代谢失调。大量 miRNA 已在与 T2DM 发病机制相关的脂肪组织巨噬细胞衍生的外泌体中被鉴定出来，但它们的致病作用仍不清楚。本研究旨在研究 miR-210 在糖尿病肥胖中的作用。
通过电子显微镜结合western blot 检测，对来自鼠巨噬细胞 RAW264.7 细胞的外泌体进行了表征。通过定量 RT-PCR 测定 miR-210 的表达。通过荧光法测定葡萄糖摄取，通过 ELISA 评估线粒体呼吸链活性。通过双荧光素酶报告和下拉实验验证 miR-210 的靶基因。通过高脂肪饮食和链脲佐菌素处理建立肥胖糖尿病小鼠模型。
高糖诱导的巨噬细胞 RAW264.7 细胞衍生的外泌体中 miR-210 高表达。巨噬细胞衍生的外泌体损害 3T3-L1 脂肪细胞的葡萄糖摄取和线粒体 CIV 复合物活性，并抑制 NADH 脱氢酶泛醌 1 亚基 4（NDUFA4）的表达。miR-210 直接与 NDUFA4 基因的 mRNA 序列结合。抑制 miR-210 减轻了巨噬细胞衍生的外泌体对 3T3-L1 脂肪细胞葡萄糖摄取和复合物 IV（CIV）活性的影响，而 NDUFA4 的过表达则抵消了巨噬细胞衍生的外泌体对葡萄糖摄取和 CIV 活性的抑制作用。此外，miR-210 敲除的小鼠表现出糖尿病肥胖发展的显著抑制。
脂肪组织巨噬细胞衍生的 miR-210 通过靶向 NDUFA4 基因表达调节葡萄糖摄取和线粒体 CIV 活性，促进肥胖糖尿病的发生。
