Mutations in methyl-CpG binding protein 2 (MECP2) gene cause Rett Syndrome (RTT), a neurodevelopmental disorder that afflicts about 1 in 10,000 girls. To understand the pathogenesis of RTT, we previously developed and characterized mouse models recapitulating RTT-associated missense mutations, MeCP2 T158M and R106W, and examined MeCP2-dependent gene expression programs in neuronal cell types of interest. We found that 1) both mutations impair MeCP2 binding to chromatin, resulting in RTT-like phenotypes in mice, but, elevation of MeCP2 mutant protein expression increase the binding of MeCP2 to chromatin and ameliorate RTT-like phenotypes in vivo, raising a new direction to develop therapeutics for RTT; 2) MeCP2 plays a necessary and sufficient role in forebrain GABAergic interneurons mediating neuronal event-related potentials (ERPs), supporting a key role for MeCP2 to regulate information processing; and 3) By developing a Cre-dependent biotin tagging system, we uncovered that MeCP2 modulates gene transcription in a mutation-dependent, cell type-specific, and in both cell and non-cell autonomous manner, particularly in mosaic females. These findings have set the premise to uncover the molecular mechanisms by which MeCP2 modulates cell type-specific gene expression, investigate the molecular etiology of RTT in heterozygous females, and test the causality of MeCP2-dependent molecular pathways that underlie the pathogenesis of RTT. With the combined genetic, genomic, molecular and cellular approaches, we hope to not only reveal novel insight into the pathogenic mechanisms of RTT, but also to expedite the development of mechanism-based therapeutics to improve treatment for RTT. Moreover, our proposed study will provide the research community at large with innovative tools and resources to investigate the epigenetic mechanisms underlying a variety of biological processes and diseases.

Public Health Relevance

Rett Syndrome is caused by mutations in the X-linked gene encoding methyl-CpG binding protein 2 (MeCP2). Despite the known genetic cause, the pathogenic mechanisms of Rett Syndrome are not well understood, thus limiting the development of diagnosis and treatment options. This proposal aims to investigate the molecular etiology of Rett syndrome in defined neuronal cell types of interest in both male and female mouse models, and aims to uncover novel therapeutics to treat Rett Syndrome and other related neurological disorders.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
2R01NS081054-06
Application #
9661180
Study Section
Neurogenesis and Cell Fate Study Section (NCF)
Program Officer
Mamounas, Laura
Project Start
2013-09-01
Project End
2023-08-31
Budget Start
2018-09-01
Budget End
2019-08-31
Support Year
6
Fiscal Year
2018
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Genetics
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
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Fasolino, Maria; Zhou, Zhaolan (2017) The Crucial Role of DNA Methylation and MeCP2 in Neuronal Function. Genes (Basel) 8:
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Lamonica, Janine M; Kwon, Deborah Y; Goffin, Darren et al. (2017) Elevating expression of MeCP2 T158M rescues DNA binding and Rett syndrome-like phenotypes. J Clin Invest 127:1889-1904
Zhao, Ying-Tao; Fasolino, Maria; Zhou, Zhaolan (2016) Locus- and cell type-specific epigenetic switching during cellular differentiation in mammals. Front Biol (Beijing) 11:311-322
Manners, Melissa T; Tian, Yuzhen; Zhou, Zhaolan et al. (2015) MicroRNAs downregulated in neuropathic pain regulate MeCP2 and BDNF related to pain sensitivity. FEBS Open Bio 5:733-40
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Kwon, Deborah Y; Zhou, Zhaolan (2014) Trapping MBD5 to understand 2q23.1 microdeletion syndrome. EMBO Mol Med 6:993-4

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