ABSTRACT

Iron has been implicated in oxidative tissue injury owing to its ability to generate reactive oxygen species (ROS). We investigated the reno-protective effects of alpha lipoic acid (ALA) by investigating its effects on the kidney isoform of NADPH oxidase (Nox4) and the specific signaling pathways, p38 MAPK and PI3K/Akt, which participate in apoptosis and survival, respectively. We established four groups of seven rats: control, 100 mg/kg ALA, 80 mg/kg iron sucrose (IS) and IS + ALA. IS and ALA were injected intravenously and rats were sacrificied after 6 h. The mRNA expression of the subunits of NADPH oxidase, Nox4 and p22phox; tumor necrosis factor-alpha (TNF-α); and kidney injury molecule-1 (KIM-1) were measured using quantitative real time polymerase chain reaction (qRT-PCR). Active caspase-3 protein expression was evaluated by immunostaining. Also, p38 MAPK and PI3K/Akt signaling pathways were analyzed using western blot. ALA suppressed the mRNA expression of Nox4, p22phox, TNF-α and KIM-1. Active caspase-3 protein expression induced by IS was decreased by ALA. ALA also suppressed p38 MAPK and activated the PI3K/Akt signaling pathway following IS administration. We found that ALA may be an effective strategy for preventing oxidative acute kidney injury caused by IS.

摘要

由于铁能够产生活性氧 (ROS)，因此铁与氧化性组织损伤有关。我们通过研究α硫辛酸 (ALA) 对 NADPH 氧化酶 (Nox4) 肾脏同工型和特定信号通路 p38 MAPK 和 PI3K/Akt 的影响，分别参与细胞凋亡和存活，从而研究了它的肾脏保护作用。我们建立了四组，每组七只大鼠：对照、100 毫克/千克 ALA、80 毫克/千克蔗糖铁 (IS) 和 IS + ALA。静脉注射IS和ALA，6小时后处死大鼠。NADPH氧化酶亚基Nox4和p22phox的mRNA表达；肿瘤坏死因子-α (TNF-α); 使用定量实时聚合酶链反应 (qRT-PCR) 测量肾损伤分子 1 (KIM-1) 和肾损伤分子 1 (KIM-1)。通过免疫染色评估活性 caspase-3 蛋白表达。此外，使用蛋白质印迹分析了 p38 MAPK 和 PI3K/Akt 信号通路。ALA 抑制 Nox4、p22phox、TNF-α 和 KIM-1 的 mRNA 表达。由IS诱导的活性caspase-3蛋白表达被ALA降低。在 IS 给药后，ALA 还抑制 p38 MAPK 并激活 PI3K/Akt 信号通路。我们发现 ALA 可能是预防 IS 引起的氧化性急性肾损伤的有效策略。