miRNA findings in BD significantly vary between studies, but are consistent to suggest a key role for these molecules in BD's pathophysiology and treatment, particularly miR-34a and miR-137.
We performed qPCR analyses of 29 miRNAs previously implicated in psychiatric illness (major depressive disorder (MDD), bipolar disorder (BP) and/or schizophrenia (SZ)) in AnCg of patients with MDD and BP versus controls. miR-132, miR-133a and miR-212 were initially identified as differentially expressed in BP, miR-184 in MDD and miR-34a in both MDD and BP (although none survived multiple correction testing and must be considered preliminary).
Taken together, we propose that miR-34a serves as a critical link between multiple etiological factors for BD and its pathogenesis through the regulation of a molecular network essential for neuronal development and synaptogenesis.