PT - JOURNAL ARTICLE AU - Rocco G. Gogliotti AU - Nicole M. Fisher AU - Branden J. Stansley AU - Carrie K. Jones AU - Craig W. Lindsley AU - P. Jeffrey Conn AU - Colleen M. Niswender TI - Total RNA Sequencing of Rett Syndrome Autopsy Samples Identifies the M<sub>4</sub> Muscarinic Receptor as a Novel Therapeutic Target AID - 10.1124/jpet.117.246991 DP - 2018 May 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 291--300 VI - 365 IP - 2 4099 - http://jpet.aspetjournals.org/content/365/2/291.short 4100 - http://jpet.aspetjournals.org/content/365/2/291.full SO - J Pharmacol Exp Ther2018 May 01; 365 AB - Mutations in the MeCP2 gene are responsible for the neurodevelopmental disorder Rett syndrome (RTT). MeCP2 is a DNA-binding protein whose abundance and ability to complex with histone deacetylase 3 is linked to the regulation of chromatin structure. Consequently, loss-of-function mutations in MeCP2 are predicted to have broad effects on gene expression. However, to date, studies in mouse models of RTT have identified a limited number of gene or pathway-level disruptions, and even fewer genes have been identified that could be considered amenable to classic drug discovery approaches. Here, we performed RNA sequencing (RNA-seq) on nine motor cortex and six cerebellar autopsy samples from RTT patients and controls. This approach identified 1887 significantly affected genes in the motor cortex and 2110 genes in the cerebellum, with a global trend toward increased expression. Pathway-level analysis identified enrichment in genes associated with mitogen-activated protein kinase signaling, long-term potentiation, and axon guidance. A survey of our RNA-seq results also identified a significant decrease in expression of the CHRM4 gene, which encodes a receptor [muscarinic acetylcholine receptor 4 (M4)] that is the subject of multiple large drug discovery efforts for schizophrenia and Alzheimer’s disease. We confirmed that CHRM4 expression was decreased in RTT patients, and, excitingly, we demonstrated that M4 potentiation normalizes social and cognitive phenotypes in Mecp2+/− mice. This work provides an experimental paradigm in which translationally relevant targets can be identified using transcriptomics in RTT autopsy samples, back-modeled in Mecp2+/− mice, and assessed for preclinical efficacy using existing pharmacological tool compounds.