Department of Endocrinology, Anhui Provincial Hospital, Anhui Medical University, Hefei, Anhui 230001, China.
Chin Med J (Engl). 2013 Nov;126(21):4054-9.
Oxidative Stress and p38 mitogen-activated protein kinase (p38MAPK) play a vital role in renal fibrosis. Pioglitazone can protect kidney but the underlying mechanisms are less clear. The purpose of this study was to investigate the effect of pioglitazone on oxidative stress and whether the severity of oxidative stress was associated with the phosphorylation level of p38MAPK.
Rat mesangial cells were cultured and randomly assigned to control group, high glucose group and pioglitazone group. After 48-hour exposure, the supernatants and cells were collected. The protein levels of p22(phox), p47(phox), phosphorylated p38MAPK, total p38MAPK were measured by Western blotting. The gene expressions of p22(phox), p47(phox) were detected by RT-PCR. The levels of intracellular reactive oxygen species (ROS) were determined by flow cytometry. The levels of superoxide dismutase (SOD) and maleic dialdehyde (MDA) in the supernatant were determined respectively.
Compared with the control group, the expression levels of p22(phox), p47(phox), phospho-p38 and ROS significantly increased, activity of SOD decreased in high glucose group, while the level of MDA greatly increased (P < 0.01). Pioglitazone significantly suppressed p22(phox), p47(phox) expressions and oxidative stress induced by high glucose. The expressions of p22(phox), p47(phox), phospho-p38MAPK and ROS generation were markedly reduced after pioglitazone treatment (P < 0.05). The activity of SOD in the the supernatant increased (P < 0.05), while the level of MDA decreased greatly by pioglitazone (P < 0.05). The level of oxidative stress was associated with the phosphorylation level of p38MAPK (P < 0.01).
Pioglitazone can inhibit oxidative stress through suppressing NADPH oxidase expression and p38MAPK phosphorylation.
氧化应激和 p38 丝裂原活化蛋白激酶（p38MAPK）在肾纤维化中起着至关重要的作用。吡格列酮可以保护肾脏，但潜在机制尚不清楚。本研究旨在探讨吡格列酮对氧化应激的影响，以及氧化应激的严重程度是否与 p38MAPK 的磷酸化水平有关。
培养大鼠肾小球系膜细胞并随机分为对照组、高糖组和吡格列酮组。暴露 48 小时后，收集上清液和细胞。通过 Western 印迹法检测 p22（phox）、p47（phox）、磷酸化 p38MAPK、总 p38MAPK 的蛋白水平。RT-PCR 检测 p22（phox）、p47（phox）的基因表达。用流式细胞术测定细胞内活性氧（ROS）水平。分别测定上清液中超氧化物歧化酶（SOD）和丙二醛（MDA）的含量。
与对照组相比，高糖组 p22（phox）、p47（phox）、磷酸化 p38MAPK 和 ROS 的表达水平显著增加，SOD 活性降低，MDA 水平显著增加（P<0.01）。吡格列酮显著抑制高糖诱导的 p22（phox）、p47（phox）表达和氧化应激。吡格列酮治疗后 p22（phox）、p47（phox）、磷酸化 p38MAPK 和 ROS 的产生明显减少（P<0.05）。上清液中 SOD 活性增加（P<0.05），而 MDA 水平显著降低（P<0.05）。氧化应激水平与 p38MAPK 的磷酸化水平相关（P<0.01）。
吡格列酮通过抑制 NADPH 氧化酶表达和 p38MAPK 磷酸化抑制氧化应激。
