MicroRNA-511 Binds to FKBP5 mRNA, Which Encodes a Chaperone Protein, and Regulates Neuronal Differentiation

Abstract

Single nucleotide polymorphisms in the FKBP5 gene increase the expression of the FKBP51 protein and have been associated with increased risk for neuropsychiatric disorders such as major depression and post-traumatic stress disorder. Moreover, levels of FKBP51 are increased with aging and in Alzheimer disease, potentially contributing to disease pathogenesis. However, aside from its glucocorticoid responsiveness, little is known about what regulates FKBP5. In recent years, non-coding RNAs, and in particular microRNAs, have been shown to modulate disease-related genes and processes. The current study sought to investigate which miRNAs could target and functionally regulate FKBP5. Following in silico data mining and initial target expression validation, miR-511 was found to suppress FKBP5 mRNA and protein levels. Using luciferase p-miR-Report constructs and RNA pulldown assays, we confirmed that miR-511 bound directly to the 3-UTR of FKBP5, validating the predicted gene-microRNA interaction. miR-511 suppressed glucocorticoidinduced up-regulation of FKBP51 in cells and primary neurons, demonstrating functional, disease-relevant control of the protein. Consistent with a regulator of FKBP5, miR-511 expression in the mouse brain decreased with age but increased following chronic glucocorticoid treatment. Analysis of the predicted target genes of miR-511 revealed that neurogenesis, neuronal development, and neuronal differentiation were likely controlled by these genes. Accordingly, miR-511 increased neuronal differentiation in cells and enhanced neuronal development in primary neurons. Collectively, these findings show that miR-511 is a functional regulator of FKBP5 and can contribute to neuronal differentiation. FKBP51 (FK506 binding protein 51 kDa) is dysregulated in several diseases, but there is a paucity of data regarding its functional regulation. FKBP51 is an Hsp90 co-chaperone that helps regulate the function of specific Hsp90 clients, such as the glucocorticoid receptor (GR) 3 and the microtubule-associated protein Tau. FKBP51 inhibits GR function, leading to delayed hypothalamic-pituitary-adrenal axis feedback and elevated circulating glucocorticoid levels (1-3), a phenomenon observed in major depression (4). In fact, single nucleotide polymorphisms in the FKBP5 gene have been associated with increased risk for depression, as well as other neuropsychiatric disorders including post-traumatic stress disorder (PTSD) (5-7). Mice with a targeted deletion of Fkbp5 display resilience to stress and accelerated hypothalamic-pituitary-adrenal axis reactivity (8, 9). FKBP51 expression is also increased in Alzheimer disease (AD), which is characterized by accumulation of misfolded Tau (10). FKBP51 has been shown to accelerate Tau oligomerization and neurotoxicity in vitro and in vivo, suggesting that it may be contributing to the pathogenesis of AD (11). Therefore, reducing FKBP51 expression is of significant interest in both depression and AD; however, little is known about what genetically regulates FKBP5, aside from...

Hippocampal Neurogenesis Is Enhanced in Adult Tau Deficient Mice

“…M17 cells were transfected with MAPT and control siRNA for a total of 72 h using siLentFect (Bio-Rad, Hercules, CA, USA) and were subsequently transfected with a GRE-luciferase reporter, a GR cDNA plasmid and pRL-CMV using Lipofectamine 2000 (Invitrogen, Waltham, MA, USA) for 48 h, as previously described [32]. For the last 4 h cells were exposed to 50 nm Dexamethasone or DMSO.…”

“…10% charcoal-stripped FBS was used throughout (Life Technologies, Carlsbad, CA, USA). Cells were lysed and subjected to Dual-Luciferase reporter assay kit (Promega, Madison, WI, USA) as previously described [32,33]. A parallel experiment was lysed in MPER and 30 µg of lysate was evaluated by Western blotting, as we have done previously [32], using Tau 12 (kind gift from Nicholas Kanaan) and Actin (Sigma Aldrich, St. Louis, MO, USA) antibodies.…”

The FKBP51 Glucocorticoid Receptor Co-Chaperone: Regulation, Function, and Implications in Health and Disease

“…So far, five different miRNA molecules have been reported or predicted to bind to the FKBP5 mRNA: miR-124 [ 107 ], miR-15a [ 120 ], miR-142 [ 120 ], miR-340 [ 120 ], and miR-511 [ 121 ] ( Figure 3 b). Specifically, miR-124 was shown to bind to FKBP5 ’s exon 9 using data from photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP) [ 107 ], although this finding has yet to be replicated.…”

“…Finally, by using multiple programs to predict potential miRNA candidates that could target FKBP5 , three miRNA were identified with potential binding to this gene: miR-142, miR-340, and miR-511 [ 121 ]. Although all three miRNAs were shown to regulate FKBP5 mRNA expression in vitro, only miR-511 was found to robustly reduce FKBP51 protein levels as well [ 121 ].…”

“…Finally, by using multiple programs to predict potential miRNA candidates that could target FKBP5 , three miRNA were identified with potential binding to this gene: miR-142, miR-340, and miR-511 [ 121 ]. Although all three miRNAs were shown to regulate FKBP5 mRNA expression in vitro, only miR-511 was found to robustly reduce FKBP51 protein levels as well [ 121 ]. miR-511 has been shown to suppress the glucocorticoid-induced upregulation of FKBP51 in cells and primary neurons, suggesting an important role of this miRNA in FKBP51’s modulatory function in GR activity [ 122 ].…”