The genetic underpinnings of mental health disorders are highly complex, involving multifaceted interactions between risk genes, the environment, and experiential factors. It is well known that adverse early life events confer significantly greater susceptibility to psychiatric conditions in later life. However, the epigenetic mechanisms by which environmental factors interact with genetic programs in the nervous system remain poorly understood. This is partially due to the complex heterogeneity of neuronal cell types and the limitations of existing techniques. Here we propose to investigate the epigenetic modifications such as DNA methylation and chromatin organization induced by early-life stress with conceptually and technically innovative approaches. We plan to map the stress-induced DNA methylation changes by directly sequencing the methylated DNA and by directly examining the dynamic association of methyl- CpG binding proteins (MBPs) with methylated DNA. To achieve this, we will generate two transgenic mouse lines: one line expresses biotin ligase (BirA) and GFP in a spatially and temporally controlled manner;while the other line carries an endogenous MBP tagged with a biotinylation signal sequence. In the resulting progeny of these two mouse lines, MBP will be specifically biotinylated in a defined population of GFP-positive neurons. Following experimental treatment of these transgenic mice, the genome-wide DNA methylation loci in specific neuronal populations will be mapped by high throughput sequencing MeDIP-seq and bioMBP-ChIP-seq. In addition, the chromatin complexes associated with each MBP will be characterized by systematic mass spectrometry bioMBP-ChIP-MS/MS to investigate the molecular mechanisms underlying epigenetic modifications. With the combined genomic and proteomic approaches, we hope to gain an insight into the epigenetic mechanisms through which early-life stress interacts with susceptibility genes and confers risks to mental illness. Our proposed study will also allow greater understanding of the underlying causes of mental health disorders and provide the necessary foundation for improved diagnosis and interventions.

Public Health Relevance

The goal of this proposal is to develop an innovative strategy to investigate the epigenetic mechanisms by which environmental factors such as early life stress interact with genetics, and how these interactions increase the risk of mental illness. We plan to generate novel genetically modified mouse lines to tag methyl-CpG binding proteins specifically in a defined population of neurons. We will then investigate the epigenetic changes associated with environmental cues in the brain with both genomic and proteomic approaches. The proposed studies will be of significance not only in understanding the epigenetic control of experience-dependent brain development, but also in understanding the molecular and cellular basis of mental disorders. It is tempting to argue that our research may identify potential molecular, cellular, and circuit targets to intervene and/or prevent mental illness.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Project (R01)
Project #
5R01MH091850-02
Application #
8123187
Study Section
Special Emphasis Panel (ZMH1-ERB-L (04))
Program Officer
Beckel-Mitchener, Andrea C
Project Start
2010-08-15
Project End
2015-05-31
Budget Start
2011-06-01
Budget End
2012-05-31
Support Year
2
Fiscal Year
2011
Total Cost
$490,485
Indirect Cost
Name
University of Pennsylvania
Department
Genetics
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Iwase, Shigeki; Bérubé, Nathalie G; Zhou, Zhaolan et al. (2017) Epigenetic Etiology of Intellectual Disability. J Neurosci 37:10773-10782
Kwon, Deborah Y; Zhao, Ying-Tao; Lamonica, Janine M et al. (2017) Locus-specific histone deacetylation using a synthetic CRISPR-Cas9-based HDAC. Nat Commun 8:15315
Fasolino, Maria; Zhou, Zhaolan (2017) The Crucial Role of DNA Methylation and MeCP2 in Neuronal Function. Genes (Basel) 8:
Fasolino, Maria; Liu, Shuo; Wang, Yinsheng et al. (2017) Distinct cellular and molecular environments support aging-related DNA methylation changes in the substantia nigra. Epigenomics 9:21-31
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
Wood, Kathleen H; Johnson, Brian S; Welsh, Sarah A et al. (2016) Tagging methyl-CpG-binding domain proteins reveals different spatiotemporal expression and supports distinct functions. Epigenomics 8:455-73
Wood, Kathleen H; Zhou, Zhaolan (2016) Emerging Molecular and Biological Functions of MBD2, a Reader of DNA Methylation. Front Genet 7:93
Goffin, Darren; Brodkin, Edward S; Blendy, Julie A et al. (2014) Cellular origins of auditory event-related potential deficits in Rett syndrome. Nat Neurosci 17:804-6
Bissonnette, J M; Schaevitz, L R; Knopp, S J et al. (2014) Respiratory phenotypes are distinctly affected in mice with common Rett syndrome mutations MeCP2 T158A and R168X. Neuroscience 267:166-76

Showing the most recent 10 out of 14 publications