Inhibition of the Schizophrenia-Associated MicroRNA miR-137 Disrupts Nrg1α Neurodevelopmental Signal Transduction

Publication date: 5 July 2017
Source:Cell Reports, Volume 20, Issue 1
Author(s): Kristen Therese Thomas, Bart Russell Anderson, Niraj Shah, Stephanie Elaine Zimmer, Daniel Hawkins, Arielle Nicole Valdez, Qiaochu Gu, Gary Jonathan Bassell
Genomic studies have repeatedly associated variants in the gene encoding the microRNA miR-137 with increased schizophrenia risk. Bioinformatic predictions suggest that miR-137 regulates schizophrenia-associated signaling pathways critical to neural development, but these predictions remain largely unvalidated. In the present study, we demonstrate that miR-137 regulates neuronal levels of p55γ, PTEN, Akt2, GSK3β, mTOR, and rictor. All are key proteins within the PI3K-Akt-mTOR pathway and act downstream of neuregulin (Nrg)/ErbB and BDNF signaling. Inhibition of miR-137 ablates Nrg1α-induced increases in dendritic protein synthesis, phosphorylated S6, AMPA receptor subunits, and outgrowth. Inhibition of miR-137 also blocks mTORC1-dependent responses to BDNF, including increased mRNA translation and dendritic outgrowth, while leaving mTORC1-independent S6 phosphorylation intact. We conclude that miR-137 regulates neuronal responses to Nrg1α and BDNF through convergent mechanisms, which might contribute to schizophrenia risk by altering neural development.

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Teaser

Thomas et al. show that the schizophrenia-associated microRNA miR-137 regulates neuronal responses to neuregulin-1α and BDNF signaling. miR-137 targets multiple components of the PI3K-Akt-mTOR pathway, which act downstream of both neuregulin and BDNF. Inhibition of miR-137 blocks stimulus-induced dendritic protein synthesis and outgrowth among other responses critical to neuronal development.


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