Abnormal pattern of vitamin D receptor-associated genes and lncRNAs in patients with bipolar disorder

BACKGROUND: Bipolar disorder (BD) is a multifactorial condition. Several signaling pathways affect development of this disorder. With the purpose of exploring the role of vitamin D receptor (VDR) signaling in this disorder, we measured expression of selected mRNA coding genes and long non-coding RNAs (lncRNAs) in this pathway in patients versus normal subjects. METHODS: We measured expression of VDR-associated lncRNAs and mRNAs (SNHG6, MALAT1, Linc00511, Linc00346, VDR and CYP27B1) in the peripheral blood of BD patients vs. healthy individuals. RESULTS: Expression of SNHG6 was significantly higher in cases vs. controls (Posterior beta = 1.29, P value < 0.0001. Subgroup analysis by sex revealed significant results in both subgroups (P value < 0.0001 and P value = 0.023 for males and females, respectively). Expression of CYP27B1 was up-regulated in cases vs. controls (Posterior beta = 0.415, P < 0.0001). Such pattern was also detected among males (P < 0.0001), but not females (P = 0.419). Similarly, MALAT1 and Linc00346 were up-regulated in total cases vs. controls (Posterior beta = 0.694, P < 0.0001 and Posterior beta = 0.4, P = 0.012, respectively) and in male cases compared with male controls (Posterior beta = 0.712, P < 0.0001 and Posterior beta = 0.41, P value = 0.038, respectively). Expression of VDR was up-regulated in total cases compared with controls (Posterior beta = 0.683, P value = 0.001). Finally, expression of Linc00511 was not different between groups. MALAT1, SNHG6, CYP27B1, VDR and Linc00346 had AUC values of 0.95, 0.94, 0.91, 0.85 and 0.83 in differentiation of male patients from controls, respectively. CONCLUSION: The current study suggests VDR-associated genes as possible markers for BD.