["To investigate the effects of high glucose and 5-aza-2'-deoxycytidine (5-aza-dCyd), a selective DNA methyltransferase inhibitor, on CTGF expression and methylation levels in human glomerular mesangial cells (HMCs).", 'HMCs were treated with 5-aza-dCyd with different concentrations (0, 1, 2, 5, 10 μmol/L) for 48 h and cell lysates were collected for genomic DNA, total RNA and total protein; HMCs were cultured in DMEM medium containing different concentrations of D-glucose (5 or 30 mmol/L) and cell lysates were collected at different time points (0, 24, 48, 72 h); methylation-specific PCR (MSP) analysis was used to analyze the methylation status of CTGF gene promoter, while RT-PC and western blot were used to evaluate the expression of CTGF mRNA and protein, respectively.', 'In 5-aza-dCyd treated (48 h) HMCs, CTGF gene promoter was hemi-methylated in 0, 1, 2, or 5 μmol/L groups, and there was low expression of CTGF mRNA and protein with no statistical difference between groups (P>0.05). But its methylation was completely reversed after treated with 10 μmol/L 5-aza-dCyd and the mRNA and protein levels of CTGF in 10 μmol/L group were significantly increased compared to 0 μmol/L group (P<0.01). In the 5 mmol/L D-glucose-treated group, the promoter of CTGF was semi-methylation at all time points, and the expression levels of CTGF mRNA and protein at different time point were all low with no significant difference (P>0.05). However, in the 30 mmol/L group, the semi-methylation of CTGF promoter were detected at 0 h, and it was reduced at 24 h and completely reversed at 48 h. The expression levels of CTGF mRNA and protein at 24, 48, or 72 h in 30 mmol/L group were all significantly elevated compared to 5 mmol/L group(P<0.01).'] Do [ High glucose induce the demethylation of CTGF promoter and gene expression ]?