Ebihara I, Suzuki S, Nakamura T, Fukui M, Yaguchi Y, Tomino Y, Koide H
Department of Medicine, Juntendo University School of Medicine, Tokyo, Japan.
J Am Soc Nephrol. 1993 Jan;3(7):1387-97. doi: 10.1681/ASN.V371387.
This study was designed to assess how the expression of genes for components of the extracellular matrix is altered in a model of focal glomerular sclerosis. In this model, a unilateral nephrectomy combined with injections of puromycin aminonucleoside induces a much higher incidence of focal glomerular sclerosis. Rats received puromycin aminonucleoside on days 0, 27, 34, and 41 and underwent unilateral nephrectomy on day 22. Control rats received physiologic saline injections with and without unilateral nephrectomy. Rats from each group were killed on days 48, 60, and 80. The steady-state levels of glomerular mRNA encoding type IV collagen, the B1 and B2 chains of laminin, heparan sulfate proteoglycan, and type I and type III collagens were compared in both the puromycin aminonucleoside-treated and the control glomeruli. The mRNA levels encoding type IV collagen and laminin B1 and B2 were increased three-, two-, and twofold, respectively, on day 48 of focal glomerular sclerosis. These transcripts were further increased eight-, seven-, and eightfold, respectively, on day 80 compared with the control glomeruli (P < 0.01). In contrast, heparan sulfate proteoglycan mRNA levels were not increased on day 48 when the animals had marked proteinuria. However, the heparan sulfate proteoglycan mRNA levels did become elevated by day 60 and remained elevated thereafter. The expression of type I and type III collagen mRNA was increased 12- and 7-fold, respectively (P < 0.01), on day 80 in focal glomerular sclerosis rats compared with the controls. An immunofluorescence study revealed the accumulation of immunoglobulin M, C3, type IV collagen, laminin, heparan sulfate proteoglycan, and type I and type III collagens in the sclerotic area. These data indicate that changes in the mRNA levels for components of the basement membrane and interstitial collagen are associated with the development of glomerular sclerosis.
本研究旨在评估在局灶性肾小球硬化模型中细胞外基质成分的基因表达是如何改变的。在该模型中，单侧肾切除联合嘌呤霉素氨基核苷注射可诱导更高的局灶性肾小球硬化发生率。大鼠在第0、27、34和41天接受嘌呤霉素氨基核苷，并在第22天接受单侧肾切除。对照大鼠接受生理盐水注射，部分进行单侧肾切除，部分未进行。每组大鼠分别在第48、60和80天处死。比较嘌呤霉素氨基核苷处理组和对照组肾小球中编码IV型胶原、层粘连蛋白B1和B2链、硫酸乙酰肝素蛋白聚糖以及I型和III型胶原的肾小球mRNA稳态水平。在局灶性肾小球硬化第48天时，编码IV型胶原、层粘连蛋白B1和B2的mRNA水平分别增加了3倍、2倍和2倍。与对照肾小球相比，这些转录本在第80天时分别进一步增加了8倍、7倍和8倍（P < 0.01）。相比之下，当动物出现明显蛋白尿时，第48天时硫酸乙酰肝素蛋白聚糖mRNA水平并未升高。然而，硫酸乙酰肝素蛋白聚糖mRNA水平在第60天时确实升高，并在此后一直保持升高。与对照组相比，局灶性肾小球硬化大鼠在第80天时I型和III型胶原mRNA表达分别增加了12倍和7倍（P < 0.01）。免疫荧光研究显示免疫球蛋白M、C3、IV型胶原、层粘连蛋白、硫酸乙酰肝素蛋白聚糖以及I型和III型胶原在硬化区域积聚。这些数据表明，基底膜和间质胶原成分的mRNA水平变化与肾小球硬化的发展有关。
