The methylation state of VDR gene in pulmonary tuberculosis patients

Abstract

Background: Our previous study suggested that the methylation of vitamin D receptor (VDR) gene affected its expression and the defense against tuberculosis (TB) infection in vitro. In this study, we further investigated the methylation level of VDR gene in pulmonary TB patients. Methods: The consecutive TB patients who were admitted into our department from January 2013 to January 2015 were recruited. The potential methylation sites analyzed in this study included 16 CpG sites. The amplification of bisulfite modified genomic DNA was ligated to pUC18-T vector and the positive clone of blue-white selection was sequenced to analyze the methylation state of VDR gene. Results: This study had samples of 27 TB patients and 30 healthy controls. TB patients were in the hypermethylation state compared to the healthy controls. The significant differences between TB patients and healthy controls were detected in 7 of these 16 CpG sites. The mRNA expression of AKT, GSK3β and FOXO1 decreased in TB patients compared to that of healthy controls. Conclusions: Our study contributes to supplying more evidences that the methylation level of VDR gene affects the progression of TB.