Ye Mingji, Xie Xubiao, Peng Longkai, Tan Liang, Lan Gongbin, Yu Shaojie
Department of Urological Organ Transplantation, Central South University, Changsha, China.
Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2011 Sep;36(9):881-8. doi: 10.3969/j.issn.1672-7347.2011.09.012.
To determine the expression and mechanism of osteoactivin (OA) in the kidney by establishing SD rat model of acute cyclosporine A (CsA) toxicity.
SD rats were fed with normal diet for a week, which they were then randomly divided into 3 groups: an experimental group (gavage with cycloporin A and olive oil), a vector group (gavage with olive oil), and a control group (gavage with normal saline). SD rats were killed 2 days, 1 week, or 2 weeks after the gavage to examine the serum creatinine (SCr) and body weight. HE staining was used to detect the kidney histopathological change. Immunohistochemistry was used to observe the staining degree and area of OA. Western blot was used to detect the OA protein.The mRNA expressions of the OA, matrix metalloproteinase-13(MMP-13), and collagen type III(Col III) were examined by RT-PCR.
The body weight and SCr of the rats in the experimental group 1 week and 2 days after the gavage had no significant difference compared with the vector group or the control group (P>0.05).On the end of 2nd week, the rats' body weight was significantly reduced, and SCr significantly increased compared with the vector group or the control group (P<0.001).The main histopathological changes in the experimental group were inflammatory cell infiltration, vacuolar degeneration of interstitial cells, or tubular epithelial cell necrosis. Intense OA expression located in the tubular epithelium and interstitial fibroblasts in the kidney of the experimental group was observed by immunohistochemistry. After CsA gavage, the relative mRNA expressions of OA, MMP-13, and Col III significantly increased with time. Western blot did not find the expression of OA protein in the control and the vector group, which increased with time in the experimental group.
OA expresses in the kidney of SD rats after acute CsA toxicity and mainly expresses in the tubular epithelial cells and renal interstitium. OA is more sensitive to the damage of kidney tissue caused by CsA than by SCr. The early-phase up-regulation of OA expression in the tubular epithelium in response to renal injury caused by acute CsA toxicity might play a key role in triggering the renal interstitial fibrosis via activating expression of MMPs and collagen remodeling in SD rats.
通过建立急性环孢素A（CsA）毒性的SD大鼠模型，确定骨激活素（OA）在肾脏中的表达及机制。
SD大鼠正常饮食喂养1周后，随机分为3组：实验组（灌胃环孢素A和橄榄油）、载体组（灌胃橄榄油）和对照组（灌胃生理盐水）。灌胃后2天、1周或2周处死SD大鼠，检测血清肌酐（SCr）和体重。采用HE染色检测肾脏组织病理学变化。采用免疫组织化学观察OA的染色程度和面积。采用蛋白质印迹法检测OA蛋白。通过逆转录聚合酶链反应（RT-PCR）检测OA、基质金属蛋白酶-13（MMP-13）和Ⅲ型胶原（ColⅢ）的mRNA表达。
实验组大鼠灌胃1周和2天后的体重和SCr与载体组或对照组相比无显著差异（P>0.05）。在第2周结束时，与载体组或对照组相比，大鼠体重显著降低，SCr显著升高（P<0.001）。实验组主要组织病理学变化为炎性细胞浸润、间质细胞空泡变性或肾小管上皮细胞坏死。免疫组织化学观察到实验组大鼠肾脏肾小管上皮和间质成纤维细胞中OA表达强烈。灌胃CsA后，OA、MMP-13和ColⅢ的相对mRNA表达随时间显著增加。蛋白质印迹法未在对照组和载体组中发现OA蛋白表达，实验组中OA蛋白表达随时间增加。
急性CsA毒性后OA在SD大鼠肾脏中表达，主要表达于肾小管上皮细胞和肾间质。OA对CsA所致肾组织损伤比SCr更敏感。急性CsA毒性所致肾损伤时，肾小管上皮中OA表达的早期上调可能通过激活基质金属蛋白酶表达和胶原重塑在SD大鼠肾间质纤维化中起关键作用。
