Correlation between plasma long non-coding RNA MEG-3 and inflammatory cytokines in patients with diabetic nephropathy

To identify the correlation between the plasma long non-coding RNA maternally expressed gene 3 (lncRNA MEG-3) and inflammatory cytokines in patients with diabetic nephropathy (DN) and search for a potential index for the diagnosis of DN. Quantitative real-time PCR (qPCR) was used to assess lncRNA MEG-3 expression. The levels of plasma cytokines were detected via enzyme-linked immunosorbent assay (ELISA). 20 patients with type 2 diabetes (T2DM) and DN (DM+DN+ group), 19 patients with T2DM (DM+DN- group), and 17 healthy subjects (DM-DN-group) were finally enrolled. The expression of lncRNA MEG-3 was significantly upregulated in the DM+DN+ group compared to the DM+DN- group (p < 0.05) and the DM-DN- group (p < 0.001). Pearson's correlation analysis showed a positive correlation of lncRNA MEG-3 levels with cystatin C (Cys-C) (r = 0.468, p < 0.05), albumin-creatinine ratio (ACR) (r = 0.532, p < 0.05), and creatinine (Cr) (r = 0.468, p < 0.05), and a negative correlation with estimated glomerular filtration rate (eGFR) (r = -0.674, p < 0.01). Furthermore, the expression level of plasma lncRNA MEG-3 had a significantly positive correlation with the level of interleukin 1 beta (IL-1 beta) (r = 0.524, p < 0.05) and interleukin 18 (IL-18) (r = 0.230, p < 0.05). Binary regression analysis showed that lncRNA MEG-3 was a risk factor for DN with odds ration (OR) value of 1.71 (p < 0.05). The area under receiver operation characteristic (ROC) curve (AUC) of DN identified by lncRNA MEG-3 was 0.724. LncRNA MEG-3 was highly expressed in DN patients and showed a positive correlation with IL-1 beta, IL-18, ACR, Cys-C, and Cr.