Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
Biochem Biophys Res Commun. 2012 Aug 24;425(2):443-9. doi: 10.1016/j.bbrc.2012.07.121. Epub 2012 Jul 27.
The prognosis of patients after acute kidney injury (AKI) is poor and treatment is limited. AKI is mainly caused by renal ischemia/reperfusion injury (IRI). During the extension phase of IRI, endothelial damage may participate in ischemia and inflammation. Endothelin-1 (ET-1) which is mostly secreted by endothelial cells is an important actor of IRI, particularly through its strong vasoconstrictive properties. We aimed to analyze the specific role of ET-1 from the endothelial cells in AKI.
We used mice lacking ET-1 in the vascular endothelial cells (VEETKO). We induced IRI in VEETKO mice and wild type controls by clamping both kidneys for 30min. Sham operated mice were used as controls. Mice were sacrificed one day after IRI in order to investigate the extension phase of IRI. Kidney function was assessed based on serum creatinine concentration. Levels of expression of ET-1, its receptor ET(A), protein kinase C, eNOS, E-Cadherin and inflammation markers were evaluated by real time PCR or western blot. Tubular injury was scored on periodic acid Schiff stained kidney preparations. Lumen and wall area of small intrarenal arteries were measured on kidney slices stained for alpha smooth muscle cell actin. Oxidative stress, macrophage infiltration and cell proliferation was evaluated on slices stained for 8-hydroxy-2'-deoxyguanosine, F4/80 and PCNA, respectively.
IRI induced kidney failure and increased ET-1 and ET(A) receptor expression. This was accompanied by tubular injury, wall thickening and reduction of lumen area/wall area ratio of small renal arteries, increased oxidative stress and inflammation. These parameters were attenuated in VEETKO mice.
Our results suggest that suppression of ET-1 from the endothelial cells attenuates IRI kidney injury. Blocking ET-1 effects may represent a therapeutic strategy in the management of AKI.
急性肾损伤（AKI）患者的预后较差，治疗方法有限。AKI 主要由肾缺血/再灌注损伤（IRI）引起。在 IRI 的扩展阶段，内皮损伤可能参与缺血和炎症。内皮素-1（ET-1）主要由内皮细胞分泌，是 IRI 的重要因素，特别是通过其强烈的血管收缩特性。我们旨在分析内皮细胞中 ET-1 在 AKI 中的具体作用。
我们使用血管内皮细胞中缺乏 ET-1 的小鼠（VEETKO）。通过夹闭双侧肾脏 30min 来诱导 VEETKO 小鼠和野生型对照小鼠的 IRI。假手术小鼠作为对照。在 IRI 后一天处死小鼠以研究 IRI 的扩展阶段。根据血清肌酐浓度评估肾功能。通过实时 PCR 或 Western blot 评估 ET-1、其受体 ET(A)、蛋白激酶 C、eNOS、E-钙黏蛋白和炎症标志物的表达水平。用过碘酸希夫染色的肾切片评估肾小管损伤评分。用α平滑肌肌动蛋白染色的肾切片测量小肾内动脉的管腔和壁面积。用 8-羟基-2'-脱氧鸟苷、F4/80 和 PCNA 染色切片分别评估氧化应激、巨噬细胞浸润和细胞增殖。
IRI 诱导肾功能衰竭和增加 ET-1 和 ET(A)受体表达。这伴随着肾小管损伤、壁增厚和小肾内动脉管腔/壁面积比降低、氧化应激和炎症增加。这些参数在 VEETKO 小鼠中减弱。
我们的结果表明，从内皮细胞中抑制 ET-1 可减轻 IRI 肾损伤。阻断 ET-1 作用可能是 AKI 管理的一种治疗策略。
