A Functional riboSNitch in the 3′ Untranslated Region ofFKBP5Alters MicroRNA-320a Binding Efficiency and Mediates Vulnerability to Chronic Post-Traumatic Pain

Previous studies have shown that common variants of the gene coding for FK506-binding protein 51 (FKBP5), a critical regulator of glucocorticoid sensitivity, affect vulnerability to stress-related disorders. In a previous report,FKBP5rs1360780 was identified as a functional variant because of its effect on gene methylation. Here we report evidence for a novel functionalFKBP5allele, rs3800373. This study assessed the association between rs3800373 and post-traumatic chronic pain in 1607 women and men from two ethnically diverse human cohorts. The molecular mechanism through which rs3800373 affects adverse outcomes was established viain silico,in vivo, andin vitroanalyses. The rs3800373 minor allele predicted worse adverse outcomes after trauma exposure, such that individuals with the minor (risk) allele developed more severe post-traumatic chronic musculoskeletal pain. Among these individuals, peritraumatic circulatingFKBP5expression levels increased as cortisol and glucocorticoid receptor (NR3C1) mRNA levels increased, consistent with increased glucocorticoid resistance. Bioinformatic,in vitro, and mutational analyses indicate that the rs3800373 minor allele reduces the binding of a stress- and pain-associated microRNA, miR-320a, toFKBP5via altering theFKBP5mRNA 3′UTR secondary structure (i.e., is a riboSNitch). This results in relatively greaterFKBP5translation, unchecked by miR-320a. Overall, these results identify an important gene–miRNA interaction influencing chronic pain risk in vulnerable individuals and suggest that exogenous methods to achieve targeted reduction in poststressFKBP5mRNA expression may constitute useful therapeutic strategies.SIGNIFICANCE STATEMENTFKBP5is a critical regulator of the stress response. Previous studies have shown that dysregulation of the expression of this gene plays a role in the pathogenesis of chronic pain development as well as a number of comorbid neuropsychiatric disorders. In the current study, we identified a functional allele (rs3800373) in the 3′UTR ofFKBP5that influences vulnerability to chronic post-traumatic pain in two ethnic cohorts. Using multiple complementary experimental approaches, we show that theFKBP5rs3800373 minor allele alters the secondary structure ofFKBP5mRNA, decreasing the binding of a stress- and pain-associated microRNA, miR-320a. This results in relatively greaterFKBP5translation, unchecked by miR-320a, increasing glucocorticoid resistance and increasing vulnerability to post-traumatic pain.