Expression of matrix Gla protein and bone morphogenetic protein 2 in renal papillary tissues in patients with calcium oxalate kidney stones / 中南大学学报(医学版)

ABSTRACT

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).Them RNA 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).T-he 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 ofosteogenetic reaction or ectopic calcification.