糖基化终末产物对大鼠肾系膜细胞纤溶酶原激活物抑制物-1表达韵影响

目的：观察糖基化终末产物（AGEs）对大鼠肾系膜细胞纤溶酶原激活物抑制物-1（PAI-1）表达的影响及其与细胞外基质（ECM）成分含量的关系。方法：体外培养正常大鼠肾系膜细胞，分别用糖化牛血清白蛋白（AGEs）及未经糖化的牛血清白蛋白（BSA）处理，以常规培养的肾系膜细胞作为对照，检测不同时间、不同浓度AGEs对纤维连接蛋白（FN）、Ⅳ型胶原、PAI-1表达的影响。MTT法检测AGEs对系膜细胞增殖的作用，ELISA测定条件培养基中FN、Ⅳ型胶原及PAI-1蛋白含量，逆转录聚合酶链式反应（RT—PCR）检测系膜细胞PAI-1 mRNA的表达。结果：与相应浓度的BSA比较，AGEs（0—200mg／L）对系膜细胞增殖无明显影响，但可不同程度地刺激系膜细胞FN、Ⅳ型胶原、PAI-1蛋白的产生。RT—PCR检测显示，给予AGEs（100mg／L）的系膜细胞PAI-1 mRNA的表达明显增加（P〈0．01）。结论：AGEs促进系膜细胞PAI—1的表达，提示AGEs通过上调PAI-1的表达而减少细胞外基质降解，可能是糖尿病肾病细胞外基质积聚的原因之一。     

In situ glomerular expression of activated NF-κB in human lupus nephritis and other non-proliferative proteinuric glomerulopathy

Nuclear Factor-κB (NF-κB) has been suggested to play a role in the cellular and molecular mechanisms underlying glomerular injury. We investigated the potential role of NF-κB activation in the pathogenesis of glomerular injury in 31 patients with class III–V lupus nephritis (LN), 14 patients with non-proliferative proteinuric glomerulopathy and six normal controls. The expression of NF-κB subunits p65 and p50, and the NF-κB regulated proinflammatory mediators tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1) as well as CD68 and synaptopodin was examined by Southwestern histochemistry (SWH) or immunohistochemistry. In contrast to non-proliferative glomerulopathy and normal controls, NF-κB activation (both p65 and p50) was enhanced in glomerular endothelial, mesangial cells or infiltrating cells in class IV LN, along with upregulation of TNF-α, IL-1β, IL-6 and ICAM-1 expression. Glomerular endothelial and mesangial activation of NF-κB and mesangial ICAM-1 expression correlated with disease activity and the level of glomerular macrophage infiltration. Podocyte NF-κB overactivation (predominantly p65) paralleled podocyte expression of TNF-α and IL-1β in patients with LN and non-proliferative glomerulopathy. Podocyte staining scores of NF-κB and p65 were positively correlated with the severity of proteinuria in LN and non-proliferative glomerulopathy. These results suggest a pathogenic role for NF-κB in glomerular injury by multiple mechanisms.     

^99mTc—DTPA肾动态显像测定肾小球滤过率常见影响因素辨析

目的探讨在^99mTc—DTPA肾动态显像测定。肾小球滤过率（GFR）过程中是否有影响GFR准确性的因素存在,以确保诊断的准确性。方法对326例患者及1例健康志愿者应用^99mTc—DTPA肾动态显像测定GFR。健康志愿者首次检查在饮水500ml后5min进行;第2次检查按常规在饮水500ml后30min进行。结合肾功能曲线和GFR对检测结果进行分析。结果注射放射性的有效剂量与实测剂量不符导致GFR误差共61例,发生率为18．7％（61／326）。在该类患者中有88．5％（54／61）的病例是由于注射点有放射性药物外渗所致。有8．2％（5／61）的病例因袖口过紧导致放射性药物存留在袖口压迫点的远端并缓慢释放。有3．3％（2／61）病例在测量空针筒时没有采集注射器针帽内漏出的放射性,GFR减低。饮水后短时间内注射放射性药物,导致肾功能曲线峰值减低,排泄段抬高,GFR减低。65例糖尿病患者GFR异常增高,而肾功能曲线形态表现为正常。结论GFR的影响因素较多。综合分析肾功能曲线与GFR值,对于发现误差,确保结果的准确性具有重要意义。再密切结合病史和肾脏影像,可以进一步确保诊断的准确性。     

Apoptosis of glomerular mesangial cells induced by sublytic C5b‐9 complexes in rats with Thy‐1 nephritis is dependent on Gadd45γ upregulation

The complement C5b‐9 complexes can result in cell apoptosis, but the mechanism of sublytic C5b‐9‐mediated glomerular mesangial cell (GMC) apoptosis in Thy‐1 nephritis (Thy‐1N) remains largely unclear. The Gadd45 gene is involved in the cellular response to DNA damage and can promote cell apoptosis. In this study, both Gadd45γ expression patterns and pathologic changes of renal tissue were examined in rat Thy‐1N. Both Gadd45γ expression and GMC apoptosis were significantly decreased in Thy‐1N rats upon the depletion of complement with cobra venom factor. Our in vitro studies showed that Gadd45γ over‐expression increased sublytic C5b‐9‐induced GMC apoptosis, while Gadd45γ gene knockdown by siRNA greatly reduced GMC apoptosis. Moreover, Gadd45γ gene silencing in vivo markedly inhibited the pathologic changes in the renal tissue of Thy‐1N rats. These data suggest that Gadd45γ gene expression is involved in regulating GMC apoptosis mediated by sublytic C5b‐9 in Thy‐1N.     

肿瘤坏死因子与肾小球系膜细胞的关系

目的研究肾小球系膜细胞的肿瘤坏死因子的自分泌功能,肿瘤坏死因子对肾小球系膜细胞作用的机制。方法利用体外培养的人和大鼠的肾小球系膜细胞,通过逆转录－多聚酶链反应、原位杂交和免疫组化方法,探讨它们之间的关系。结果肾小球系膜细胞既可产生肿瘤坏死因子,又有肿瘤坏死因子受体。结论肾小球系膜细胞是肿瘤坏死因子作用的靶细胞,肿瘤坏死因子通过旁分泌和自分泌两种途径作用于肾小球系膜细胞。     

Interaction of transforming growth factor β1 with human glomerular epithelial cells in culture: opposite effects on synthesis of matrix proteins and on urokinase plasminogen activator

The effect of transforming growth factor- (TGF-) was analyzed on the synthesis of fibronectin, collagen type IV, and urokinase plasminogen activator in human glomerular epithelial cells in culture. An increase in the abundance of specific mRNA was found for collagen type IV and fibronectin. Fibronectin protein synthesis was also increased in TGF- treated cells; most of the de novo synthesized fibronectin was found as an unsoluble protein associated with extracellular matrix. In the same cells the amount of plasminogen activator mRNA was found leading also to a decreased surface expression of urokinase plasminogen activator. The data support the concept that by upregulating matrix protein synthesis and downregulating the plasminogen activator system, TGF- favors the development of sclerosis.Abbreviations FN Fibronectin - GEC Glomerular epithelial cells - TGF- Transforming growth factor - uPA Urokinase-type plasminogen activator     

Distribution of renal integrin receptors and their ligands in congenital nephrotic syndrome of the finnish type

The aim of this study was to examine the distribution of 1 and v integrins (Ints) and some of their ligands in the kidneys of patients with congenital nephrotic syndrome of the Finnish type (CNF) and in controls using indirect immunofluorescence with monoclonal antibodies. The mesangial reactivity of Int 1 and Int 1 subunits was more variable and an increased glomerular reactivity with Int 3 and Int-6 antibodies was found in CNF kidneys than in controls. Int 2 subunit was either completely missing from or found in significantly lesser amounts in CNF kidney glomeruli. The immunoreactivity for Int v was more variable, fainter and also more granular in CNF samples than in control kidneys. The glomerular reactivity for Int 5 was more diffuse and weaker, and in sclerotic Bowman's capsules more intense in CNF kidneys than in controls. Immunoreactivity for Int 6 was restricted and was comparable in extent in CNF and control kidneys. Of the extracellular matrix components studied, the expression of EDAFn, EDBFn, OncFn, Ln 2 chain, Ln 1 chain and tenascin was increased. This is also seen in several glomerular diseases with inflammation and sclerosis. Immunoreactivity for vitronectin was decreased. Several differences were found in the intensity or location of the immunostaining for the 1 and v Ints and their ligands in CNF kidneys compared with controls, which have not been found in any other proteinuric disease. Disturbed Int expression pattern in CNF may specifically reflect the disturbance of glomerular function caused by the primary defect in this disease.     

The PPAR gamma 2 Pro12Ala variant predicts ESRD and mortality in patients with type 1 diabetes and diabetic nephropathy

The Pro12Ala polymorphism in the peroxisome proliferator-activated receptor-γ2 gene is suggested to associate with diabetic nephropathy and cardiovascular disease in type 2 diabetes. The aim of this study was to investigate the polymorphism in relation to diabetic nephropathy, end-stage renal disease (ESRD), mortality and cardiovascular (CVD) events in type 1 diabetic patients.This prospective observational follow-up study included 415 type 1 diabetic patients with overt diabetic nephropathy (252 men; age 42.2 ± 10.4 years [mean ± SD], duration of diabetes 28.3 ± 8.8 years, GFR 66 ± 8.8 ml/min) and 428 patients with longstanding type 1 diabetes and persistent normoalbuminuria (230 men; age 45.4 ± 11.6 years, duration of diabetes 27.8 ± 10.1 years). Follow-up: 8.1 (0.0–12.8) years (median [range]).There where no significant differences between cases and controls in genotype (p = 0.51) or allele frequencies (p = 0.25). Cox regression analysis revealed a covariate-adjusted hazard ratio (HR) for all-cause mortality in patients with the Ala/Ala genotype of 2.44 (1.23–4.84). The Pro12Ala polymorphism did not predict CVD events. However, the Ala/Ala genotype predicts ESRD (covariate-adjusted HR 2.60 (1.11–6.07)). Furthermore, Carriers of the Ala-allele had a higher rate of decline in GFR (p = 0.040).In conclusion, the Pro12Ala polymorphism is not associated with type 1 diabetic nephropathy. The Ala-allele is associated with enhanced decline in GFR and predicts ESRD and all-cause mortality in patients with nephropathy.     

Acquired glomerular lesions in patients with Down syndrome

The long-term survival of persons with Down syndrome has dramatically increased over the past 50 years. There are no studies addressing the spectrum of glomerular lesions in these patients. We reviewed the clinical-pathologic characteristics of 17 patients with Down syndrome who underwent renal biopsy. The cohort consisted of 12 whites and 5 African Americans with mean age of 29 years (range, 6-45 years). History of hypothyroidism was present in 8 patients. Renal presentations included renal insufficiency (15 patients, mean serum creatinine 3.4 mg/dL), proteinuria (all patients, including 3 with nephrotic syndrome, mean 24-hour urine protein 4.2 g), and hematuria (14 patients, including 4 with gross hematuria). The glomerular diseases found on biopsy were IgA nephropathy (n = 5 patients), focal segmental glomerulosclerosis (n = 4), membranoproliferative glomerulonephritis (n = 2), acute postinfectious glomerulonephritis (n = 2), pauci-immune crescentic glomerulonephritis (n = 2), membranous glomerulonephritis (n = 1), and lupus nephritis (n = 1). Follow-up (mean, 47 months; range, 2-141 months) was available on 16 patients (94%). Two patients (1 with membranous glomerulonephritis and 1 with acute postinfectious glomerulonephritis) had complete remission; 8 patients (4 with IgA nephropathy, 2 with focal segmental glomerulosclerosis, 1 with lupus nephritis, and 1 with acute postinfectious glomerulonephritis) had chronic kidney disease; and 6 patients (2 with pauci-immune crescentic glomerulonephritis, 2 with membranoproliferative glomerulonephritis, 1 with IgA nephropathy, and 1 with focal segmental glomerulosclerosis) progressed to end-stage renal disease, 4 of whom died. In summary, a wide spectrum of glomerular diseases can be seen in patients with Down syndrome, with IgA nephropathy and focal segmental glomerulosclerosis being the most common. Renal biopsy is necessary to determine the type of glomerular lesion and appropriate treatment.