Effect of impaired functional domains of osteopontin on renal crystal formation : Analyses of OPN transgenic and OPN knockout mice.

骨桥蛋白功能域受损对肾晶体形成的影响：OPN 转基因和 OPN 敲除小鼠的分析。

基本信息

批准号：
21791520
负责人：
HIGASHIBATA Yuji
金额：
$ 2.58万
依托单位：
Nagoya City University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Young Scientists (B)
财政年份：
2009
资助国家：
日本
起止时间：
2009 至 2011
项目状态：
已结题

项目摘要

Osteopontin(OPN) has been described as playing a nonredundant role in renal crystal formation.(1) We investigated the effects of impaired domains of OPN, namely, the Arg-Gly-Asp(RGD) sequence and two calcium-binding sites on crystal formation. We used wild-type mice(WT group), OPN knockout mice(KO group), and OPN knockout mice carrying either a transgene in which the RGD sequence had been modified to Arg-Gly-Glu(RGE group) or whose two calcium-binding sites had been deleted(CaX group). In the WT group, crystal deposits increased gradually at the renal corticomedullary junction in an orderly fashion, whereas those in the KO group were observed sporadically in the renal cortex. In both the CaX and RGE groups, deposits were localized near the corticomedullary junction. Crystal deposition was greatest in the WT group and least in the KO group. The number of deposits in the RGE group was nearly equal to that in the KO group. The results indicated the possibility that each domain contributes to the mechanism by which OPN stimulates crystal formation.(2) We investigated the effects of an antimurine osteopontin antibody(35B6-Ab) that specifically reacts with the(162) SLAYGLR(168) sequence, which is exposed by thrombin cleavage and is located adjacent to the RGD sequence, on renal crystal formation. Scanning electron microscopy showed that the crystals in 35B6-Ab-treated mice were aberrantly formed and their density was low ; in contrast, the crystals in untreated mice that were not administered 35B6-Ab had a radial pattern of growth(rosette petal-like crystals), and their density was high. We conclude that thrombin-cleaved osteopontin plays an important role in formation of renal calcium crystals and that 35B6-Ab contributes to the remarkable inhibition of early-stage renal crystal formation by preventing renal tubular cell injury and crystal-cell attachment.

骨桥蛋白（OPN）被描述为在肾脏晶体形成中起非冗余的作用。（1）我们研究了OPN受损域的影响，即Arg-Gly-Asp（RGD）序列（RGD）序列和两个钙结合位点对晶体形成。我们使用了野生型小鼠（WT组），OPN敲除小鼠（KO组）和OPN敲除小鼠，该小鼠携带了一个转基因，其中RGD序列已修改为Arg-Gly-Gly-Glu（RGE组）或两个钙结合位点已被删除（CAX组）。在WT组中，晶体沉积物在肾皮质甲状腺结局处逐渐增加，而在肾脏皮质中偶尔观察到KO组的晶体沉积物。在CAX和RGE组中，沉积物均位于皮质典交界处。在WT组中，晶体沉积最大，在KO组中最少。 RGE组的存款数几乎等于KO组的存款数。结果表明，每个结构域有助于OPN刺激晶体形成的机制。（2）我们研究了一种抗粘着蛋白骨桥蛋白抗体（35b6-ab）的影响，该抗体（35B6-AB）特异性地与（162）slayglr（168）序列（168）序列，该序列暴露于螺旋素的序列中，并与ren固定相邻，并与ISS相邻。扫描电子显微镜表明，在35B6 AB处理的小鼠中的晶体异常形成，其密度较低。相比之下，未治疗的小鼠中未施用的35b6-ab的晶体具有径向的生长模式（玫瑰花花瓣状晶体），它们的密度很高。我们得出的结论是，凝血酶裂解的骨桥蛋白在形成肾钙晶体中起着重要作用，而35B6-AB通过预防肾小管细胞损伤和晶体细胞附着有助于显着抑制早期肾脏晶体形成。