UNIVERSITY OF MASSACHUSETTS
Schizophrenia is defined by a lack of a straightforward genetic cause for a very large majority of affected individuals. The prefrontal cortex (PFC), among other brain regions, is thought to be frequently in subjects in schizophrenia, as reflected by its functional hypoactivity and dysregulated expression for a diverse set of genes. The underlying molecular mechanisms remain unknown but there is evidence that the prolonged maturation of the PFC, extending into or even beyond the second decade of life, plays a crucial role for normal human development and the neurobiology of schizophrenia. Recently, we presented the first evidence that a subset of epigenetic markings, including trimethylated histone H3-lysine 4 at sites of gene promoters, is involved in the dynamic regulation of PFC chromatin during throughout pre- and postnatal development, and may be altered in some cases with schizophrenia. Specifically, we will combine two of the most innovative approaches in the field of neurosciences as it pertains to epigenetics, by selectively sorting neuronal chromatin followed by massively parallel sequencing of immunprecipitates (ChIP-seq) to obtain insight into the epigenomic landscape of prefrontal neurons. We will profile developmental and disease-related changes in histone methylation markings associated with active promoters (trimethyl-H3K4) or transcription (trimethyl-H3K36) selectively in PFC neurons. Furthermore, we will study in conditional mutant mice the role of a candidate histone lysine methyltransferase, Mll1 (mixed-lineage leukemia 1) for normal and diseased prefrontal development, by expressing Cre recombinase selectively in weanling PFC and then monitor behavioral and molecular alterations in the adult animal. The experiments proposed here, which are designed to be accomplished within the challenge grants award period of 24 months, will clarify, for the first time, whether or not chromatin of human PFC neurons is developmentally regulated and altered in disease. The answer to this question on a genome-wide level will be critical in order to find out whether or not chromatin-based mechanisms are part of a final common pathophysiology underlying prefrontal dysfunction in the substantial portion of subjects diagnosed with schizophrenia.