亚溶量C5b-9与足细胞损伤及其信号传导的研究进展

膜性肾病的发病机制与亚溶量C5b-9(SC5b-9)诱导足细胞损伤有关.SC5b-9刺激足细胞产生的氧化剂、蛋白酶、前列腺素类、细胞外基质及各种细胞因子对足细胞有损伤作用.SC5b-9对足细胞的作用主要表现为引起足细胞凋亡、足细胞脱落以及对细胞周期的影响.MAPK通路在SC5b-9导致足细胞损伤中起到重要的作用.     

儿童局灶节段性肾小球硬化

局灶节段性肾小球硬化（FSGS）近年来有增多趋势，FSGS不仅是一种形态学描述，而被视为一种临床病理综合征，表现为蛋白尿，常为肾病水平蛋白尿，并有局灶节段分布的肾小球硬化和足突融合。FSGS可为原发性（特发性）、继发性和遗传家族性。最近FSGS被区分为5种变异型，提示其不同的发病机制和预后，这5型包括特异FSGS、门周型、细胞型、顶端病变和塌陷型。该文还就FSCS的治疗和预后进行了讨论。     

罗格列酮对糖尿病鼠足细胞分布排泄的影响

目的观察糖尿病(DM)大鼠肾小球足细胞的表达及尿液足细胞(UPC)排泄的改变,及罗格列酮对DM大鼠肾小球足细胞分布及UPC排泄的影响.方法雄性Wistar大鼠随机分为正常对照组和糖尿病模型组;后者经STZ诱导糖尿病模型成功后再随机分为糖尿病组和治疗组(罗格列酮 5 mg·kg-1·d-1).实验10 w末测24 h尿蛋白定量(TP)、血糖(BG)、肾素活性(RA)、血管紧张素Ⅱ(AngⅡ)和醛固酮(Ald)水平.间接免疫荧光法检测尿沉渣足细胞特异性标志蛋白PCX(podocalyxin)以观察UPC排泄水平,检测肾小球上皮细胞蛋白-1(GLEPP1)以观察肾小球足细胞分布.结果DM组及治疗组UPC、TP、BG、PRA、AngⅡ、Ald水平较对照组明显升高(P＜0.01).与DM组相比,治疗组TP、BG、AngⅡ显著降低(P＜0.01),UPC亦降低(P＜0.05).病理组织肾小球荧光染色示GLEPP1在对照组正常,DM组明显缺失,治疗组呈节段性缺失.UPC与TP、Ang Ⅱ呈正相关(r=0.41,0.38,P＜0.05),而与BG、PRA、Ald无显著相关性(r=0.19,0.23,0.13,P＞0.05).结论肾小球足细胞缺失参与糖尿病肾病(DN)的发病.罗格列酮可减轻DN大鼠尿蛋白,减少足细胞脱落及尿液足细胞的排泄.     

Role of NOD2-regulated Snail expression in epithelial-mesenchymal transition in podocyte of diabetic nephropathy

Objective To observe the expression of NOD2 and epithelial-mesenchymal transition (EMT) related proteins in podocytes in high glucose environment, and explore the molecular mechanism of NOD2 involved in EMT. Methods The human glomerular podocytes were the subjects of study. α-SMA and Nephrin expressions were detected by immunofluorescence; the mRNA and protein expressions of NOD2, Snail and EMT related proteins (α-SMA , Desmin, E-cadherin, Nephrin) were detected by real-time fluorescence quantitative PCR and Western blotting. The podocytes were stimulated by high-glucose after shRNA interfering the of NOD2 expression, and the expressions of Snail and subsequent EMT-related proteins were detected by Western blotting. Prior to the activation of NOD2 by muramyl dipeptide (MDP), shRNA was used to interfere with the expression of Snail. E-cadherin, Nephrin, Desmin, and α-SMA were detected by Western blotting. Results After 24 hours of high glucose stimulation, PCR and Western blotting results showed that the expressions of NOD2 and Snail were significantly increased; the expressions of epithelial phenotype proteins E-cadherin and Nephrin were down-regulated; and the expressions of interstitial phenotype proteins Desmin and α-SMA were increased (all P＜0.05); while there was no significant change in the hypertonic control group. After interference with NOD2, the abnormal expression of Snail and EMT related proteins were all recovered. After interference with Snail expression, Compared with the MDP group, the protein expressions of E-cadherin and Nephrin were significantly increased (all P＜0.05); the expressions of Desmin and α-SMA were significantly decreased. Conclusions High glucose can induce NOD2 expression in podocytes, and promote podocyte epithelial-mesenchymal transition by upregulating Snail expression. Gene intervention targeting the NOD2/Snail/EMT pathway can reduce high-glucose-induced podocyte injury and may provide new ideas for the treatment of diabetic nephropathy.     

Podocytes are new cellular targets of haemoglobin‐mediated renal damage

Recurrent and massive intravascular haemolysis induces proteinuria, glomerulosclerosis, and progressive impairment of renal function, suggesting podocyte injury. However, the effects of haemoglobin (Hb) on podocytes remain unexplored. Our results show that cultured human podocytes or podocytes isolated from murine glomeruli bound and endocytosed Hb through the megalin–cubilin receptor system, thus resulting in increased intracellular Hb catabolism, oxidative stress, activation of the intrinsic apoptosis pathway, and altered podocyte morphology, with decreased expression of the slit diaphragm proteins nephrin and synaptopodin. Hb uptake activated nuclear factor erythroid‐2‐related factor 2 (Nrf2) and induced expression of the Nrf2‐related antioxidant proteins haem oxygenase‐1 (HO‐1) and ferritin. Nrf2 activation and Hb staining was observed in podocytes of mice with intravascular haemolysis. These mice developed proteinuria and showed podocyte injury, characterized by foot process effacement, decreased synaptopodin and nephrin expression, and podocyte apoptosis. These pathological effects were enhanced in Nrf2‐deficient mice, whereas Nrf2 activation with sulphoraphane protected podocytes against Hb toxicity both in vivo and in vitro. Supporting the translational significance of our findings, we observed podocyte damage and podocytes stained for Hb, HO‐1, ferritin and phosphorylated Nrf2 in renal sections and urinary sediments of patients with massive intravascular haemolysis, such as atypical haemolytic uraemic syndrome and paroxysmal nocturnal haemoglobinuria. In conclusion, podocytes take up Hb both in vitro and during intravascular haemolysis, promoting oxidative stress, podocyte dysfunction, and apoptosis. Nrf2 may be a potential therapeutic target to prevent loss of renal function in patients with intravascular haemolysis. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

尿足细胞及其标志蛋白podocalyxin测定对2型糖尿病肾病的诊断价值

目的探讨尿足细胞及其标志蛋白(podocalyxin,PCX)测定对2型糖尿病肾病(diabetic nephropathy,DN)的诊断价值。方法选取160例临床确诊为2型糖尿病的患者,依据尿清蛋白(Alb)/肌酐(Cr)比值(UACR)将患者分为正常清蛋白尿组(NA)、微量清蛋白尿组(MA)和大量清蛋白尿组(LA);选取同期体检健康者50人作为对照组。用流式细胞术检测尿中足细胞,ELISA法检测尿中PCX含量,两者之间相关性采用pearson相关分析。结果 NA组、MA组、LA组以及健康人对照组尿足细胞检测结果分别为(0.96±0.36)、(3.09±0.86)、(5.53±1.44)和(0.65±0.31)units/μL,尿PCX检测结果分别为(0.62±0.13)、(1.49±0.47)、(2.19±0.47)和(0.46±0.08)ng/μmol Cr,糖尿病患者尿足细胞及PCX显著高于健康人对照组,差异有统计学意义(P0.05),且随着病程进展而升高。Pearson相关分析结果表明,尿足细胞和PCX呈正相关(r=0.86,P0.01)。在NA患者中,足细胞及PCX阳性率分别为51.9%、73.1%,差异有统计学意义(P0.05);两者联合检测阳性率为76.9%。结论糖尿病患者肾损伤时尿足细胞和PCX明显增加,两者联合检测对于2型糖尿病肾病早期诊断具有重要价值。     

液基薄层细胞学技术联合免疫荧光染色在尿足细胞检测中的应用

目的观察液基薄层细胞学技术(TCT)联合间接免疫荧光染色对尿液中足细胞的染色效果并探讨其临床应用价值。方法收集50例2型糖尿病肾病患者和14例健康对照者晨尿标本,TCT制片与传统离心涂片后均行间接免疫荧光染色,观察足细胞形态。结果 64例标本中TCT制片满意率(85.94%)高于传统离心涂片(50.00%),TCT制片的足细胞检出率(73.47%)高于传统离心涂片(51.02%),差异有统计学意义(P0.05)。2种方法检测足细胞均阳性时,TCT制片的阅片效果优于传统离心涂片。结论较传统离心涂片而言,TCT制片联合间接免疫荧光染色在尿足细胞检测中具有优越性。