Peripheral expression of long non-coding RNAs in bipolar patients.

BACKGROUND: Long non-coding RNAs (lncRNAs) have established roles in the pathogenesis of diverse human disorders including neuropsychiatric disorders.

METHODS: In the current study, we evaluated expression levels of six apoptosis-related lncRNAs (CCAT2, TUG1, PANDA, NEAT1, FAS-AS1 and OIP5-AS1) in the peripheral blood of bipolar disorder (BD) patients and healthy subjects to assess their contribution in the pathogenesis of BD.

RESULTS: CCAT2, TUG1 and PANDA were up-regulated in total BD patients compared with total healthy subjects (P values = 0.006, <0.001 and 0.004 respectively) while OIP5-AS1 was down-regulated (P = 0.001). When expression levels of these genes were compared between patients and sex-matched healthy subjects, CCAT2 and TUG1 expression levels were only different in male subgroups; while PANDA expression was different in both male and female subgroups compared with the corresponding control subgroups. Transcript levels of lncRNAs were not correlated with any of demographic or clinical parameters of BD patients or controls after adjustment for gender. Pairwise correlations between expression levels of lncRNAs followed a disease-dependent manner. Based on receiver operating characteristic curves, among the assessed lncRNAs TUG1 had the highest diagnostic power in BD. Combination of transcript levels of CCAT2, TUG1, PANDA and OIP5-AS1 improved both sensitivity and specificity resulting in diagnostic power of 0.96.

CONCLUSION: Our data demonstrated a possible role of certain lncRNAs in the pathogenesis of BD and potentiated them as diagnostic markers in this disorder.