Gu Junfei, Ye Shandong, Wang Shan, Sun Wenjia, Hu Yuanyuan
Department of Endocrinology, Anhui Provincial Hospital Affiliated to Anhui Medical University, Hefei, Anhui 230001, China.
Department of Endocrinology, Anhui Provincial Hospital Affiliated to Anhui Medical University, Hefei, Anhui 230001, China. Email:
Chin Med J (Engl). 2014;127(9):1755-60.
The renoprotective mechanisms of adenosine monophosphate (AMP)-activated protein kinase (AMPK) agonist - metformin have not been stated clearly. We hypothesized that metformin may ameliorate inflammation via AMPK interaction with critical inflammatory cytokines. The aim of this study was to observe the effects of metformin on expression of nuclear factor-κB (NF-κB), monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1) and transforming growth factor-beta 1 (TGF-β1) induced by high glucose (HG) in cultured rat glomerular mesangial cells (MCs).
MCs were cultured in the medium with normal concentration glucose (group NG, 5.6 mmol/L), high concentration glucose (group HG, 25 mmol/L) and different concentrations of metformin (group M1, M2, M3). After 48-hour exposure, the supernatants and MCs were collected. The expression of NF-κB, MCP-1, ICAM-1, and TGF-β1 mRNA was analyzed by real time polymerase chain reaction. Western blotting was used to detect the expression of AMPK, phospho-Thr-172 AMPK (p-AMPK), NF-κB p65, MCP-1, ICAM-1, and TGF-β1 protein.
After stimulated by HG, the expression of NF-κB, MCP-1, ICAM-1, TGF-β1 mRNA and protein of MCs in group HG increased significantly compared with group NG (P < 0.05). Both genes and protein expression of NF-κB, MCP-1, ICAM-1, TGF-β1 of MCs induced by high glucose were markedly reduced after metformin treatment in a dose-dependent manner (P < 0.05). The expression of p-AMPK increased with the rising of metformin concentration, presenting the opposite trend, while the level of total-AMPK protein was unchanged with exposure to HG or metformin. Conlusion Metformin can suppress the expression of NF-κB, MCP-1, ICAM-1 and TGF-β1 of glomerular MCs induced by high glucose via AMPK activation, which may partly contribute to its reno-protection.
单磷酸腺苷（AMP）激活的蛋白激酶（AMPK）激动剂二甲双胍的肾脏保护机制尚未明确阐述。我们推测二甲双胍可能通过与关键炎性细胞因子相互作用的AMPK改善炎症。本研究的目的是观察二甲双胍对高糖（HG）诱导的培养大鼠肾小球系膜细胞（MCs）中核因子κB（NF-κB）、单核细胞趋化蛋白-1（MCP-1）、细胞间黏附分子-1（ICAM-1）和转化生长因子-β1（TGF-β1）表达的影响。
将MCs培养于正常浓度葡萄糖（NG组，5.6 mmol/L）、高浓度葡萄糖（HG组，25 mmol/L）和不同浓度二甲双胍（M1组、M2组、M3组）的培养基中。暴露48小时后，收集上清液和MCs。通过实时聚合酶链反应分析NF-κB、MCP-1、ICAM-1和TGF-β1 mRNA的表达。采用蛋白质印迹法检测AMPK、磷酸化苏氨酸-172 AMPK（p-AMPK）、NF-κB p65、MCP-1、ICAM-1和TGF-β1蛋白的表达。
与NG组相比，HG刺激后HG组MCs中NF-κB、MCP-1、ICAM-1、TGF-β1 mRNA和蛋白表达显著增加（P < 0.05）。二甲双胍处理后，高糖诱导的MCs中NF-κB、MCP-1、ICAM-1、TGF-β1的基因和蛋白表达均呈剂量依赖性显著降低（P < 0.05）。p-AMPK的表达随二甲双胍浓度升高而增加，呈现相反趋势，而总AMPK蛋白水平在暴露于HG或二甲双胍时不变。结论二甲双胍可通过激活AMPK抑制高糖诱导的肾小球MCs中NF-κB、MCP-1、ICAM-1和TGF-β1的表达，这可能部分有助于其肾脏保护作用。
