基质Gla蛋白与骨形成蛋白2在草酸钙肾结石患者Randall钙斑中的表达

Expression of matrix Gla protein and bone morphogenetic protein 2 in renal papillary tissues in patients with calcium oxalate kidney stones

目的:对比基质Gla蛋白(matrix Gla protein,MGP)及骨形成蛋白2(bone morphogenetic protein 2,BMP-2)在草酸钙结石肾乳头Randall钙化斑组织中的表达,探讨其在草酸钙肾结石形成过程中的相关机制。方法:收集中南大学湘雅医院泌尿外科2015年4月至12月期间住院的30例草酸钙肾结石患者的肾乳头钙化斑组织标本作为实验组,10例同期患肾肿瘤行根治性肾切除术患者的肾乳头组织标本作为对照组,利用实时荧光定量聚合酶链式反应(real-time polymerase chain reaction,RT-PCR)和Western印迹检测MGP和BMP-2在肾乳头组织中的表达,并采用免疫组织化学技术观察MGP和BMP-2在肾乳头组织中的表达。结果:1)RT-PCR检测实验组和对照组MGP mRNA的表达量为0.760±0.804和1.365±0.348,差异有统计学意义(P<0.05);实验组和对照组BMP-2 mRNA表达量分别为2.500±0.725和1.485±0.870,差异有统计学意义(P<0.05)。2)Western印迹检测实验组和对照组的MGP蛋白表达量分别为0.130±0.424和0.202±0.704,差异无统计学意义(P>0.05);实验组和对照组BMP-2蛋白表达量为0.885±0.220和0.682±0.272,差异有统计学意义(P<0.05)。3)免疫组织化学结果显示实验组MGP的表达较对照组低,而实验组BMP-2表达较对照组高(均P<0.05)。结论:草酸钙肾结石患者的肾乳头组织内BMP-2表达增多,MGP表达减少,草酸钙肾结石的形成可能是一种与MGP和BMP-2相关的类成骨反应或异位钙化。

Objective： To compare expression levels of matrix Gla protein（MGP） and bone morphogenetic protein 2（BMP-2） in Randall＇s plaque of renal papillary tissues in patients with calcium oxalate kidney stones and the underlying mechanism for stone formation. Methods： A total of 30 samples of Randall＇s plaque in renal papillary tissues from patients with calcium oxalate kidney stones were collected from the Department of Urology of Xiangya Hospital of Central South University from April, 2015 to December, 2015 and served as an experimental group. Ten samples of renal papillary tissues in patients undergone renal tumor nephrectomy were collected from the same hospital and served as a control group. The expressions of MGP and BMP-2 mRNA and protein were detected by quantitative real-time PCR and Western blot.Meanwhile, immunohistochemical technique was used to observe the expressions of MGP and BMP-2 in different parts of renal papillary tissues in the 2 groups. Results： 1） The mRNA expression levels of MGP in the experimental group and the control group were 0.760±0.804 and 1.365±0.348, respectively, with significant difference between them（P〈0.05）. ThemRNA levels of BMP-2 in the experimental group and the control group were 2.500±0.725 and 1.485±0.870, respectively, with significant difference between them（P〈0.05）. The expression levels of MGP protein in the experimental group and the control group were 0.130±0.424 and 0.202±0.704, respectively, with no significant difference between them（P〈0.05）. The expression levels of BMP-2 protein in the experimental group and the control group were 0.885±0.220 and 0.682±0.272, respectively, with significant difference between them（P〈0.05）. The immunohistochemistry showed that the protein expression of MGP in the experimental group was lower than that in the control group, while the protein expression of BMP-2 in the experimental group was higher than that in the control group（both P〈0.05）. Conclusion： The BMP-2 expression is increased while MGP expression is decreased in renal papillary tissues in patients with calcium oxalate kidney stones, and the formation of calcium oxalate kidney stone might be a kind of osteogenetic reaction or ectopic calcification.