Heparan sulfate of perlecan is involved in glomerular filtration
Heparan sulfate of perlecan is involved in glomerular filtration
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DOI：
10.1681/asn.2004050387
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发表时间：
2005-06-01
影响因子：
13.6
通讯作者：
Tryggvason, K
中科院分区：
文献类型：
--
作者：
Morita, H;Yoshimura, A;Tryggvason, K
串珠素是一种硫酸乙酰肝素蛋白聚糖，是肾小球基底膜的主要成分。为了理解串珠素的硫酸乙酰肝素链在肾小球滤过中的作用，对Hspg 2（Delta 3/Delta 3）小鼠的肾脏进行了详细分析，其串珠素在N-末端结构域I中缺乏硫酸乙酰肝素附着位点。宏观，组织学，和电子显微镜观察，以及免疫组织化学和免疫电子显微镜分析，使用特异性抗体对串珠蛋白聚糖和聚集蛋白核心蛋白，发现这些小鼠在生理条件下没有显着异常。聚乙烯亚胺染色显示肾小球基底膜电荷密度无明显变化。其他硫酸乙酰肝素蛋白聚糖、聚集蛋白和胶原蛋白XVIII型以及串珠素的转录物的表达水平与野生型同窝仔相似。由Hspg 2（Delta 3/Delta 3）成纤维细胞合成的串珠素中约40%被硫酸肝素取代，60%被硫酸软骨素取代。由野生型成纤维细胞合成的所有串珠素都含有硫酸肝素，表明Hspg 2（Delta 3/Delta 3）串珠素上糖胺聚糖的改变的取代。免疫组化结果显示，Hspg 2（Delta 3/Delta 3）肾小球基底膜中硫酸软骨素的表达明显增加。当腹腔注射BSA时，Hspg 2（Delta 3/Delta 3）小鼠表现出显著的蛋白尿。这些结果表明串珠素的硫酸乙酰肝素链在肾小球滤过，特别是大量蛋白质的滤过中起重要作用。
Perlecan is a heparan sulfate proteoglycan and a major component of the glomerular basement membrane. To understand the role of heparan sulfate chains of perlecan in glomerular filtration, detailed analyses were performed of the kidneys of Hspg2(Delta 3/Delta 3) mice, whose perlecan lacks heparan sulfate attachment sites in N-terminal domain I. Macroscopic, histologic, and electron microscopic observations, as well as immunohistochemical and immunoelectron microscopic analyses using specific antibodies against perlecan and agrin core proteins, revealed no significant abnormalities in these mice under physiologic conditions. Polyethyleneimine staining demonstrated no significant changes in charge density in the glomerular basement membrane. Transcripts of other heparan sulfate proteoglycans, agrin, and collagen type XVIII, as well as perlecan, were expressed at similar levels to those in the wild-type littermates. Approximately 40% of the perlecan synthesized by Hspg2(Delta 3/Delta 3) fibroblasts was substituted with heparin sulfate and 60% was substituted with chondroitin sulfate. All of the perlecan synthesized by wild-type fibroblasts contained heparin sulfate, indicating an altered substitution of glycosaminoglycans on Hspg2(Delta 3/Delta 3) perlecan. Immunostaining indicated that the level of chondroitin sulfate was actually increased in the Hspg2(Delta 3/Delta 3) glomerular basement membrane. When administered intraperitoneally with BSA, Hspg2(Delta 3/Delta 3) mice exhibited remarkable proteinuria. These findings suggest that heparan sulfate chains of perlecan play an important role in glomerular filtration, especially of a large amount of protein.