肾上腺髓质肽在大鼠足细胞损伤模型中调控肾小球壁层上皮细胞分化  

Adrenomedullin regulates the differentiation of glomerular parietal epithelial cells in podocyte-injuried rat model

作　　者：薛汝群 杨望 张敏[2] 赵仲华 刘学光 XUE Ru qun;YANG Wang;ZHANG Min;ZHAO Zhong hua;LIU Xue guang(Department of Pathology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China;Department of Clinical Medicine, Fudan University, Shanghai 200032, China)

机构地区：[1]复旦大学基础医学院病理学系,上海200032 [2]复旦大学临床医学院,上海200032

出　　处：《复旦学报（医学版）》2018年第5期611-619,共9页Fudan University Journal of Medical Sciences

基　　金：国家自然科学基金(81100505);复旦大学上海医学院正谊学者基金~~

摘　　要：目的探讨肾上腺髓质肽(adrenomedullin,AM)是否通过调控肾小球壁层上皮细胞(parietal epithelial cells,PECs)分化参与对大鼠足细胞损伤模型的保护作用及可能的分子机制。方法雄性SD大鼠经一次性腹腔注射嘌呤霉素氨基核苷(puromycinaminonucleoside,PAN)(15 mg/100 g体重)建立足细胞损伤模型,随机分为模型组和治疗组,治疗组每天经尾静脉注射AM蛋白质(6.6μg/100 g体重)。分别在首次注射PAN后7、14和21天,观察大鼠尿蛋白水平及肾组织形态改变,并经免疫组化染色、双重或三重免疫荧光染色,检测足细胞数量、肾小球AM的表达、PECs分化以及Notch3表达变化。结果大鼠PAN肾病模型表现为大量蛋白尿、肾小球节段性损伤、足细胞计数显著减少。AM/claudin-1双重荧光染色显示PECs中AM表达显著增强且出现于毛细血管袢内。AM治疗可改善大鼠尿蛋白及肾组织形态,减少足细胞丢失,14天时显著增加共表达PECs(claudin-1)及足细胞特异性标志蛋白(WT-1和synaptopodin)的细胞数。Ki67与claudin-1共定位表达于PECs,但未与WT-1共表达。AM显著抑制由PAN所致的Notch3表达。结论在大鼠PAN足细胞损伤模型中,PECs中AM表达上调提示机体的一种代偿性保护机制,AM可能通过下调Notch3信号通路而促进PECs分化,参与其促进损伤后修复的作用。Objective To elucidate whether adrenomedullin （AM） could regulate the differentiation of glomerular parietal epithelial cells （PECs） to play a protective role in a podocyte injuried rat model and its potential molecular mechanism. Methods A podocyte injuryed model was established by a single intraperitoneal injection of puromycinaminonucleoside （PAN） 15 mg/100 g body wt in male SD rats. Rats were randomly assigned to receive intravenous injection of AM at a daily dose of 6.6 μg/100 g body wt. Animals were sacrificed on 7,14 and 21 d, respectively. Urine albumin was analyzed by SDS PAGE. The histologic alterations were observed under light microscopy. Immunohistochemistry staining,double or triple immunofluorescence staining were applied to observe podocyte number, the expression of AM in glomeruli, the activation and differentiation of PECs,and the expression of Notch3.Results Rat PAN nephrosis showed massive albuminuria,glomerular injury and podocyte depletion. AM expression in PECs was significantly upregulated by PAN and AM＊ /claudin-1 ＊ cells migrated to glomerular tuft. AM protein significantly increased podocyte number, ameliorated albuminurine and improved renal morphology. The number of cells co expressing PECs （claudin 1） and podocyte specific markers （WT-1 and synaptopodin） were markedly increased in AM treated rats on day 14. Ki67 co expressed with claudin 1 in PECs, not with WT-1. AM protein significantly decreased Notch3 activity induced by PAN. Conclusions In rat PAN nephrosis,the upregulation of AM in PECs may represent a compensatory protective mechanism. AM may replenish the injured podocytes by enhancing PECs differentiation into podocytes through modulating Notch3 signaling pathway, thus contributing to its reno protective effect in rat PAN nephrosis.

关 键 词：肾上腺髓质肽 壁层上皮细胞 足细胞 嘌呤霉素氨基核苷 NOTCH 大鼠 

分 类 号：R361.3[医药卫生—病理学]