Zheng F, Li L, Liu Z
Research Institute of Nephrology, Jinling Hospital, Nanjing.
Zhonghua Yi Xue Za Zhi. 1995 Apr;75(4):197-200, 253.
The levels of extracellular matrix protein mRNAs were increased prior to the appearance of histological glomerulosclerosis in isolated glomeruli from several animal models. Striker studied renal biopsies (Seminar in Nephrology, 13:508,1993). We made a comparable study in human renal biopsies to assess the levels of glomerular alpha 2 (IV) and alpha 3 (IV) collagen gene expressions in renal biopsies. Renal biopsy specimens were obtained from 11 patients (7 IgA nephropathy and 4 mesangial proliferative glomerulonephritis). Glomerular lesion was divided into 5 grades. The amount of collagen type IV in glomerular matrix was evaluated by immunoperoxidase staining using a monoclonal antibody to type IV collagen. For gene expression analysis, glomeruli were dissected out from about 10% of each biopsy specimen. The expressions of alpha 2 (IV) and alpha 3 (IV) collagen mRNAs were analyzed by using in situ reverse transcription coupled with polymerase chain reaction. Each PCR reaction contained an amount of cDNA template equivalent to that obtained from 1/10 of a glomerulus, alpha 2 (IV) and alpha 3 (IV) collagen mRNAs were detected in all specimens. All 3 cases of IgAN with grade III glomerular lesion had a more marked increment of glomerular alpha 2 (IV) collagen cDNA than that of the other 3 IgAN patients with grade II lesion (the intensity of PCR product, grade III 0.54 +/- 0.12, VS grade II 0.25 +/- 0.08, P < 0.05). No discrepancies were detected in the level of glomerular alpha 3 (IV) collagen cDNA and the intensity of collagen IV staining between these two groups of IgAN. Interestingly, in MsPGN patients there was no difference in the expression of glomerular alpha 2 (IV) collagen mRNA between grade II and grade III glomerular lesions. The results suggested that the detection of glomerular alpha 2 (IV) collagen mRNA level in IgAN patients may help to define the pathological classification.
在几种动物模型的分离肾小球中，细胞外基质蛋白mRNA水平在组织学肾小球硬化出现之前就升高了。斯特赖克研究了肾活检（《肾脏病学研讨会》，13:508,1993）。我们对人类肾活检进行了类似研究，以评估肾活检中肾小球α2（IV）和α3（IV）胶原基因的表达水平。从11名患者（7例IgA肾病和4例系膜增生性肾小球肾炎）获取肾活检标本。肾小球病变分为5级。使用抗IV型胶原单克隆抗体通过免疫过氧化物酶染色评估肾小球基质中IV型胶原的含量。对于基因表达分析，从每个活检标本的约10%中分离出肾小球。通过原位逆转录结合聚合酶链反应分析α2（IV）和α3（IV）胶原mRNA的表达。每个PCR反应包含的cDNA模板量相当于从1/10个肾小球获得的量，在所有标本中均检测到α2（IV）和α3（IV）胶原mRNA。所有3例肾小球病变为III级的IgA肾病患者肾小球α2（IV）胶原cDNA的增加比其他3例病变为II级的IgA肾病患者更明显（PCR产物强度，III级0.54±0.12，对比II级0.25±0.08，P<0.05）。这两组IgA肾病患者在肾小球α3（IV）胶原cDNA水平和IV型胶原染色强度方面未检测到差异。有趣的是，在系膜增生性肾小球肾炎患者中，II级和III级肾小球病变之间肾小球α2（IV）胶原mRNA的表达没有差异。结果表明，检测IgA肾病患者肾小球α2（IV）胶原mRNA水平可能有助于确定病理分类。
