Andrea L Johnstone1, Jiaqi J O'Reilly2, Annika J Patel3, Zhihong Guo4, Nadja S Andrade3, Marco Magistri3, Lubov Nathanson5, Rustam Esanov6, Brooke H Miller7, Gustavo Turecki8, Shaun P Brothers3, Zane Zeier3, Claes Wahlestedt9. 1. The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA; EpiCypher, Durham, NC, USA. 2. The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA; Institute for Biomedical Sciences, George Washington University, Washington, DC, USA. 3. The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA. 4. The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA. 5. Institute for Neuro Immune Medicine, Nova Southeastern University, Fort Lauderdale, FL, USA. 6. The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA. 7. McKnight Brain Institute and Department of Psychiatry, University of Florida College of Medicine, Gainesville, FL, USA. 8. Department of Psychiatry, McGill University, Quebec, Canada. 9. The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA. Electronic address: cwahlestedt@med.miami.edu.
Abstract
BACKGROUND: With the capacity to modulate gene networks in an environmentally-sensitive manner, the role of epigenetic systems in mental disorders has come under intense investigation. Dysregulation of epigenetic effectors, including microRNAs and histone-modifying enzymes, may better explain the role of environmental risk factors and the observed heritability rate that cannot be fully attributed to known genetic risk alleles. Here, we aimed to identify novel epigenetic targets of the schizophrenia-associated microRNA 132 (miR-132). METHODS: Histone modifications were quantified by immunodetection in response to viral-mediated overexpression of miR-132 while a luminescent reporter system was used to validate targets of miR-132 in vitro. Genome-wide profiling, quantitative PCR and NanoSting were used to quantify gene expression in post-mortem human brains, neuronal cultures and prefrontal cortex (PFC) of mice chronically exposed to antipsychotics. Following viral-mediated depletion of Enhancer of Zeste 1 (EZH1) in the murine PFC, behaviors including sociability and motivation were assessed using a 3-chambered apparatus and forced-swim test, respectively. RESULTS: Overexpression of miR-132 decreased global histone 3 lysine 27 tri-methylation (H3K27me3), a repressive epigenetic mark. Moreover, the polycomb-associated H3K27 methyltransferase, EZH1, is regulated by miR-132 and upregulated in the PFC of schizophrenics. Unlike its homolog EZH2, expression of EZH1 in the murine PFC decreased following chronic exposure to antipsychotics. Viral-mediated depletion of EZH1 in the mouse PFC attenuated sociability, enhanced motivational behaviors, and affected gene expression pathways related to neurotransmission and behavioral phenotypes. CONCLUSIONS: EZH1 is dysregulated in schizophrenia, sensitive to antipsychotic medications, and a brain-enriched miR-132 target that controls neurobehavioral phenotypes.
BACKGROUND: With the capacity to modulate gene networks in an environmentally-sensitive manner, the role of epigenetic systems in mental disorders has come under intense investigation. Dysregulation of epigenetic effectors, including microRNAs and histone-modifying enzymes, may better explain the role of environmental risk factors and the observed heritability rate that cannot be fully attributed to known genetic risk alleles. Here, we aimed to identify novel epigenetic targets of the schizophrenia-associated microRNA 132 (miR-132). METHODS: Histone modifications were quantified by immunodetection in response to viral-mediated overexpression of miR-132 while a luminescent reporter system was used to validate targets of miR-132 in vitro. Genome-wide profiling, quantitative PCR and NanoSting were used to quantify gene expression in post-mortem human brains, neuronal cultures and prefrontal cortex (PFC) of mice chronically exposed to antipsychotics. Following viral-mediated depletion of Enhancer of Zeste 1 (EZH1) in the murine PFC, behaviors including sociability and motivation were assessed using a 3-chambered apparatus and forced-swim test, respectively. RESULTS: Overexpression of miR-132 decreased global histone 3 lysine 27 tri-methylation (H3K27me3), a repressive epigenetic mark. Moreover, the polycomb-associated H3K27 methyltransferase, EZH1, is regulated by miR-132 and upregulated in the PFC of schizophrenics. Unlike its homolog EZH2, expression of EZH1 in the murine PFC decreased following chronic exposure to antipsychotics. Viral-mediated depletion of EZH1 in the mouse PFC attenuated sociability, enhanced motivational behaviors, and affected gene expression pathways related to neurotransmission and behavioral phenotypes. CONCLUSIONS: EZH1 is dysregulated in schizophrenia, sensitive to antipsychotic medications, and a brain-enriched miR-132 target that controls neurobehavioral phenotypes.