足细胞蛋白Nephrin、Podocin和肾小球疾病

【摘要】肾小球疾病是指累及两侧肾小球的一类疾病,多以蛋白尿为主要临床表现,由于发病机理尚不明确,因此疾病早期缺乏准确有效的检测和诊断手段。近来研究发现足细胞蛋白Nephrin和Podocin在多种肾小球疾病发生发展和诊断预测中起重要作用。本文就近几年Nephrin、Podocin与肾小球疾病的相关研究作一综述。 【关键词】足细胞蛋白;Nephrin;Podocin;肾小球疾病     

Pathogenetische Aspekte des nephrotischen Syndroms

Zusammenfassung Das nephrotische Syndrom ist gekennzeichnet durch Eiweißverlust im Urin, Hypoalbuminämie, Hyperlipidämie und Ödeme. Verschiedene Erkrankungen verursachen ein nephrotisches Syndrom, indem sie zu einer Schädigung des glomerulären Podozyten führen. Diese spezialisierte Epithelzelle bildet zusammen mit dem kapillären Endothel und der glomerulären Basalmembran die Filtrationsbarriere, welche den Übertritt von Eiweiß aus der Zirkulation in das Primärfiltrat verhindert. Störungen dieses Filters führen zur Proteinurie. Die 3 häufigsten primären glomerulären Erkrankungen, welche ein nephrotisches Syndrom auslösen, sind Minimal-change-Disease, membranöse Glomerulonephritis und die primäre fokale segmentale Glomerulosklerose. Selten sind die familiären Formen des nephrotischen Syndroms; die Charakterisierung der genetischen Defekte hat jedoch wesentlich zum Verständnis der Podozytenfunktion und der Pathogenese des nephrotischen Syndroms beigetragen.

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Glomeruli from patients with nephrin mutations show increased number of ciliated and poorly differentiated podocytes

Background

Podocytes are postmitotic, highly specialized cells which maintain the glomerular filtration barrier (GFB). Their injury is characterized by foot processes effacement and change in protein expression leading to proteinuria and end-stage kidney disease.

高同型半胱氨酸血症对膜性肾病大鼠肾组织Nephrin WT1表达的影响

目的:观察高同型半胱氨酸血症对膜性肾病(MN)大鼠肾组织Nephrin、WT1表达的影响,探讨MN足细胞损伤凋亡的可能发生机制.方法:将30只SD雄性大鼠随机分为正常组和模型组,正常组不给予任何处理,模型组尾静脉注射16mg/kg阳离子化牛血清白蛋白(c-BSA)复制MN大鼠模型,于正式免疫第1,2,3,4周末检测24h尿蛋白(24h UTP)水平,并于第4周末检测大鼠血浆尿素(Ure)、血肌酐(Cre)及同型半胱氨酸(Hcy)水平.同时取材鉴定大鼠肾组织成模情况,免疫组化检测大鼠肾组织中Nephrin、WT1的表达,结果:模型组大鼠造模第4周成模稳定,病理表现典型.随造模时间延长,模型组24h UTP呈逐渐增加趋势,与前一周末比较差异均有统计学意义(P＜0.01),2、3、4周末24h UTP较正常组有明显增加(P＜0.01).Nephrin在模型组肾组织中表达较正常组显著减少(P＜0.01),WT1的表达与正常组比较无显著差异.HCY与肾组织Nephrin的表达呈明显负相关,与第4周末24hUTP呈明显正相关,与血浆尿素、血肌酐、肾组织WT1无明显相关关系.结论:MN中高Hey血症可能通过下调Nephrin的表达参与了足细胞的损伤凋亡过程,积极监测Hcy水平及控制高Hcy血症有利于防止MN的进展.     

温阳活血利水方对阿霉素肾病大鼠肾小球足细胞nephrin表达的影响

目的观察温阳活血利水法治疗微小病变肾病综合征的疗效,并观察对足细胞nephrin表达的影响,以探讨其作用机制。方法用阿霉素（ADR）诱导一种类似人类微小病变肾病模型,一周后用温阳活血方（治疗组）治疗,持续4周。并设空白对照组（正常组）、病理对照组（造模组）。观察实验大鼠的一般情况;检测大鼠24小时尿蛋白定量;检测总蛋白、白蛋白、总胆固醇、甘油三酯、低密度脂蛋白的水平;采用RT-PCR和免疫荧光染色测定大鼠肾小球Nephrin的mRNA和蛋白表达水平;光学显微镜观察肾组织形态学变化;电镜下观察足细胞足突的变化。结果模型组24小时尿蛋白定量明显升高（P〈0．01）,血清总蛋白、白蛋白明显降低（P〈0．01）,血清脂质水平升高（P〈0．01）,NephrinmRNA与蛋白表达明显减少,足突融合明显。两个治疗组均能降低24小时尿蛋白定量,升高血清总蛋白、白蛋白水平（P〈0．01）。温阳活血利水方能降低血清脂质水平（P〈0．01）。两个治疗组均能改善肾组织中NephrinmRNA与蛋白的表达的减少,改善其肾组织的病理改变。结论温阳活血利水方减少蛋白尿,可能与改善阿霉素肾病大鼠肾小球Nephrin的表达减少有关。     

Biomarker of Early Glomerular Injury in Pre-eclampsia

Objectives: Nephrin is an integral part of podocytes that together with endothelial cells and the basement form the glomerular filtration barrier. Placental ischemia triggers a cascade of events that ultimately result in endothelial malfunction, hypertension, podocytopathy and fetal compromise. Methods: We review the literature to determine if urine nephrin measurements could serve as a useful biomarker to detect early podocyte injury in pre-eclampsia. Results: Our search identifies eight studies published to date. The findings of these studies demonstrate that urine nephrin excretion plays a critical role in the pathogenesis of proteinuria during pre-eclampsia and that this is a good indicator of glomerular injury. Conclusion: There is thus an urgent need for a large multi-centre clinical study using standardized recruitment criteria to determine the full potential of this biomarker in clinical practice.     

An experimental assessment of toxic potential of nanoparticle preparation of heavy metals in streptozotocin induced diabetes

Nanoparticle preparations of heavy metals have attracted enormous scientific and technological interest. Biologically produced nanoparticle preparations of heavy metals are elaborately described in traditional texts and being widely prescribed. The underlying interactions of nano preparations within the physiological fluids are key feature to understand their biological impact. In this perspective, we performed an experimental assessment of the toxicity potential of a marketed metallic preparation named Vasant Kusumakar Ras (VKR), wherein different heavy metals in composite form are reduced to nanoparticle size to produce the desired effect in diabetes and its complications.VKR (50 mg/kg) was administered to Albino Wistar rats rendered diabetic using streptozotocin (90 mg/kg) in 2 days old neonates. Anti-hyperglycemic effect was observed with VKR along with increased levels of plasma insulin. Renal variables including total proteins and albumin along with glomerular filtration rate were found to improve biochemically. The results were supplemented by effects on different inflammatory and growth factors like TNF-α, nitric oxide, TGF-β and VEGF. However, the results observed in kidney histopathology were not in accordance with the biochemical parameters. Inflammation observed in kidney was confirmed by immunostaining metallothionein, which was due to the accumulation of heavy metals. Furthermore, mercury accumulation in kidney further confirmed by autometallography, which activated mononuclear phagocyte system, which generated an immune response. This was further supported by increase in the extent of apoptosis in kidney tissues.In conclusion, nanoparticle preparations of heavy metals can be toxic to kidney if it is not regulated with respect to its surface chemistry and dosage.     

Genetic forms of nephrotic syndrome: a single-center experience in Brussels

The aim of the study was to present our experience in treating children with genetic forms of nephrotic syndrome and diagnosing these diseases. We retrospectively reviewed the clinical data, mutational analyses, histopathological features, treatment modalities, and outcome of 26 consecutive children (20 families) suffering from congenital and/or steroid-resistant nephrotic syndrome who were assessed by genetic analysis. Ten out of 26 children (38%) had congenital nephrotic syndrome, 4/26 (15%) had infantile nephrotic syndrome, 10/26 (38%) had late-onset nephrotic syndrome, and 2/26 (9%) had asymptomatic proteinuria. We detected a mutation in 21/26 (81%) patients and in 15/20 (75%) families. NPHS1 mutation analyses were positive in 4/20 (20%), NPHS2 mutations in 4/20 (20%), WT1 mutations in 4/20 (20%), and PLCE1 mutations in 3/20 (15%) families. NPHS1 and PLCE1 mutations were solely found in patients with the earliest onset. The majority of patients, especially those with early onset of nephrotic syndrome, had serious adverse events related to the nephrotic status, and 19/26 (73%) reached end-stage renal failure at a median age of 27 months. Genetic forms of nephrotic syndrome comprise a heterogeneous group of genetic mutations. The progression toward end-stage renal failure is the rule but is highly variable between patients. Other participating authors are listed in the appendix. An erratum to this article can be found at     

亚硒酸钠对糖尿病肾病大鼠肾脏脂联素和nephrin表达的影响

目的 探讨亚硒酸钠对糖尿病肾病大鼠肾脏脂联素和nephrin表达的影响及其相互间的关系,从而研究亚硒酸钠与脂联素、nephrin在糖尿病肾病中的作用机制.方法 通过链脲佐菌素法加高脂饮食诱导模拟大鼠糖尿病肾病模型,实验设完全空白对照组、糖尿病组、糖尿病药物干预组,药物干预组每日给予亚硒酸钠溶液灌胃,其它组给予等量盐水溶液灌胃.10周后处死大鼠,取血、尿标本测相关生化指标,取肾脏组织分别提取DNA和蛋白质标本,石蜡切片光镜观察病理改变及免疫组化分析蛋白表达定位,实时定量PCR法检测脂联素mRNA表达、RT-PCR法检测nephrin mRNA表达,Western印迹法检测脂联素和nephrin蛋白表达.结果 亚硒酸钠干预组大鼠生化指标较糖尿病组明显改善,光镜下观察亚硒酸钠干预组病理改变较糖尿病组明显减轻.免疫组化分析,亚硒酸钠干预组脂联素蛋白着色较糖尿病组明显增强,且肾小管、肾小球内均有着色;糖尿病组nephrin蛋白表达着色较空白对照组减少,亚硒酸钠干预组较糖尿病组着色明显增多.亚硒酸钠干预组脂联素mRNA和蛋白表达明显高于糖尿病组和正常对照组,差异有统计学意义(均P＜0.05).亚硒酸钠干预组nephrin mRNA和蛋白表达均较糖尿病组明显增加,但仍较空白对照组降低,差异均有统计学意义(P＜0.05).结论 亚硒酸钠能促进大鼠肾脏脂联素和nephrin表达,表明亚硒酸钠、脂联素和nephrin在延缓和防治糖尿病肾病的发生发展中可能起重要作用.