Expression analysis of vitamin D receptor-associated lncRNAs in epileptic patients

Vitamin D has been vastly acknowledged as a neuroactive steroid controlling neurodevelopment. As it exerts its functions through activation of vitamin D receptor (VDR), several studies have assessed the role of VDR in brain function. More recently, a number of long non-coding RNAs (lncRNAs) have been recognized that alter expression of VDR. In the current study, we evaluated expression of four VDR-related lncRNAs (LINC00511, LINC00346, SNHG6 and SNHG16) in peripheral blood of 40 epileptic patients and 39 healthy subjects using quantitative real time PCR method. The relative expression levels of SNHG16 and LINC00511 were higher in epileptic patients compared with healthy subjects. For SNHG16, the difference was only significant between male patients and male controls, while LINC00511 had the opposite pattern. The results of Quantile regression model showed significant associations between SNHG6 and SNHG16 expressions and gender (P values of 0.027 and 0.009 respectively). Significant correlations were detected between expression levels of SNHG6 and SNHG16 (r = 0.32, P = 0.004), SNHG6 and LINC00346 (r = 0.37, P = 0.001), SNHG16 and LINC00346 (r = 0.30, P = 0.007) as well as SNHG16 and LINC00511 (r = 0.29, P = 0.009). Expression of LINC00346 was inversely correlated with vitamin D levels only in male epileptic patients (r = -0.58, P = 0.011). Expression of SNHG6 was correlated with vitamin D levels in male controls but no other subgroups (r = 0.51, P = 0.044). Based on the results of ROC curve analysis, SNHG16 had the diagnostic power of 0.86 in male subjects. Taken together, the current study provides evidences for dys-regulation of VDR-related lncRNAs in epileptic patients. The clinical significance of these finding should be explored in future studies.