Romi Muhammad Mansyur, Arfian Nur, Tranggono Untung, Setyaningsih Wiwit Ananda Wahyu, Sari Dwi Cahyani Ratna
Department of Anatomy, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.
Department of Surgery, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.
BMC Nephrol. 2017 Oct 31;18(1):326. doi: 10.1186/s12882-017-0736-x.
Uric acid (UA) plays important roles in inducing renal inflammation, intra-renal vasoconstriction and renal damage. Endothelin-1 (ET-1) is a well-known profibrotic factor in the kidney and is associated with fibroblast expansion. We examined the role of hyperuricemia conditions in causing elevation of ET-1 expression and kidney injury.
Hyperuricemia was induced in mice using daily intraperitoneal injection of uric acid 125 mg/Kg body weight. An NaCl injection was used in control mice. Mice were euthanized on days-7 (UA7) and 14 (UA14). We also added allopurinol groups (UAL7 and UAL14) with supplementation of allopurinol 50 mg/Kg body weight orally. Uric acid and creatinine serum were measured from blood serum. Periodic Acid Schiff (PAS) and Sirius Red staining were done for glomerulosclerosis, tubular injury and fibrosis quantification. mRNA expression examination was performed for nephrin, podocin, preproEndothelin-1 (ppET-1), MCP-1 and ICAM-1. PDGFRβ immunostaining was done for quantification of fibroblast, while α-SMA immunostaining was done for localizing myofibroblast. Western blot analysis was conducted to quantify TGF-β1, α-SMA and Endothelin A Receptor (ETAR) protein expression.
Uric acid and creatinine levels were elevated after 7 and 14 days and followed by significant increase of glomerulosclerosis and tubular injury score in the uric acid group (p < 0.05 vs. control). Both UA7 and UA14 groups had higher fibrosis, tubular injury and glomerulosclerosis with significant increase of fibroblast cell number compared with control. RT-PCR revealed down-regulation of nephrin and podocin expression (p < 0.05 vs. control), and up-regulation of MCP-1, ET-1 and ICAM-1 expression (p < 0.05 vs. control). Western blot revealed higher expression of TGF-β1 and α-SMA protein expression. Determination of allopurinol attenuated kidney injury was based on reduction of fibroblast cell number, inflammation mediators and ppET-1 expression with reduction of TGF-β1 and α-SMA protein expression.
UA induced glomerulosclerosis, tubular injury and renal fibrosis with reduction of podocyte function and inflammatory mediator elevation. ET-1 and fibroblast expansion might modulate hyperuricemia induced renal fibrosis.
尿酸（UA）在诱导肾脏炎症、肾内血管收缩和肾损伤中起重要作用。内皮素-1（ET-1）是肾脏中一种众所周知的促纤维化因子，与成纤维细胞增殖有关。我们研究了高尿酸血症状态在导致ET-1表达升高和肾损伤中的作用。
通过每日腹腔注射125mg/Kg体重的尿酸诱导小鼠高尿酸血症。对照组小鼠注射氯化钠。在第7天（UA7）和第14天（UA14）对小鼠实施安乐死。我们还添加了别嘌醇组（UAL7和UAL14），口服补充50mg/Kg体重的别嘌醇。从血清中测量尿酸和肌酐。进行高碘酸希夫（PAS）和天狼星红染色以量化肾小球硬化、肾小管损伤和纤维化。对nephrin、podocin、前内皮素-1（ppET-1）、单核细胞趋化蛋白-1（MCP-1）和细胞间黏附分子-1（ICAM-1）进行mRNA表达检测。进行血小板衍生生长因子受体β（PDGFRβ）免疫染色以量化成纤维细胞，而进行α-平滑肌肌动蛋白（α-SMA）免疫染色以定位肌成纤维细胞。进行蛋白质免疫印迹分析以量化转化生长因子-β1（TGF-β1）、α-SMA和内皮素A受体（ETAR）蛋白表达。
7天和14天后尿酸和肌酐水平升高，随后尿酸组的肾小球硬化和肾小管损伤评分显著增加（与对照组相比，p<0.05）。与对照组相比，UA7和UA14组均有更高的纤维化、肾小管损伤和肾小球硬化，成纤维细胞数量显著增加。逆转录-聚合酶链反应（RT-PCR）显示nephrin和podocin表达下调（与对照组相比，p<0.05），MCP-1、ET-1和ICAM-1表达上调（与对照组相比，p<0.05）。蛋白质免疫印迹显示TGF-β1和α-SMA蛋白表达更高。别嘌醇减轻肾损伤的测定基于成纤维细胞数量、炎症介质和ppET-1表达的减少以及TGF-β1和α-SMA蛋白表达的减少。
尿酸诱导肾小球硬化、肾小管损伤和肾纤维化，同时足细胞功能降低且炎症介质升高。ET-1和成纤维细胞增殖可能调节高尿酸血症诱导的肾纤维化。
