Umekawa T, Yamate T, Amasaki N, Kohri K, Kurita T
Department of Urology, Kinki University School of Medicine, Osaka, Japan.
Urol Int. 1995;55(1):6-10. doi: 10.1159/000282737.
We had sequenced a cDNA of calcium oxalate urinary stone protein extracted with 0.1 M EDTA. cDNA sequences showed complete homology between urinary stone protein and human osteopontin (OPN, bone sialoprotein I). In the present study, we investigated the expression of OPN mRNA in the rat kidney in an experimental model of renal stone formation using glyoxylic acid and 1,25-dihydroxyvitamin D3 (D3). In the renal stone formation model with and without renal failure, OPN mRNA was shown to be localized by in situ hybridization using an OPN cRNA probe mainly in the distal convoluted tubule of the kidney, and was enhanced compared with the normal control which was sporadically positive. By Northern blot analysis, the expression of OPN mRNA was shown to be increased by about 5.2-fold in the renal stone formation model and 2.3-fold in D3-administered rats compared with controls. However, no change in the expression of OPN mRNA was observed in an acute renal failure model induced by gentamicin or in rats administered glycoxylic acid alone. Therefore, the promotion of OPN mRNA expression was intrinsic to this stone formation model, and not secondary to acute renal failure because of obstruction by microcrystals in the renal tubules or gentamicin.
我们已对用0.1M乙二胺四乙酸（EDTA）提取的草酸钙尿结石蛋白的互补脱氧核糖核酸（cDNA）进行了测序。cDNA序列显示尿结石蛋白与人骨桥蛋白（OPN，骨唾液蛋白I）完全同源。在本研究中，我们使用乙醛酸和1,25 - 二羟基维生素D3（D3），在肾结石形成的实验模型中研究了大鼠肾脏中OPN信使核糖核酸（mRNA）的表达。在有和没有肾衰竭的肾结石形成模型中，使用OPN互补核糖核酸（cRNA）探针通过原位杂交显示OPN mRNA主要定位于肾脏的远曲小管，并且与偶尔呈阳性的正常对照相比有所增强。通过Northern印迹分析，与对照相比，在肾结石形成模型中OPN mRNA的表达增加了约5.2倍，在给予D3的大鼠中增加了2.3倍。然而，在庆大霉素诱导的急性肾衰竭模型或单独给予乙醛酸的大鼠中未观察到OPN mRNA表达的变化。因此，OPN mRNA表达的促进是该结石形成模型所固有的，而不是继发于肾小管中微晶阻塞或庆大霉素所致的急性肾衰竭。
