Regulation of Histone Methylation by Methyl-CpG-Binding Protein 2 in Primary Culture of Mouse Cortical Neurons
Y.Jiang; S.Akbarian.
Abstract
The Rett syndrome gene, methyl-CpG-binding protein 2 (Mecp2), is associated with the regulation of chromatin structure and function, including enzyme-mediated covalent modifications of histone N-terminal tails. Alterations such as histone hyperacetylation were reported not only at defined genomic sequences but also in bulk chromatin from Mecp2-deficient cells.
We use primary cultures to monitor Mecp2 expression and Mecp2-regulated histone modification changes during the course of neuronal maturation. Neuronal cultures from the developing cortex plate (mouse, E15.5) show robust changes in Mecp2 levels between DIV2 and 14, similar to the previously observed increase in neuronal Mecp2 expression during development of cerebral cortex in vivo. Notably, neuronal cultures from wildtype animals show distinct changes in levels of open- and closed chromatin-associated histone methylation in bulk chromatin during the course of maturation in vitro. Ongoing cell culture experiments will compare histone methylation profiles of bulk chromatin and at regulatory sequences of selected candidate genes (Bdnf, Dlx5, Mdr1) between wildtype and Mecp2-deficient neurons.
Lay Summary
MECP2 is thought to play a pivotal role in the silencing of other genes, via regulating the state of histone methylation. Histones are proteins in which MeCP2 interacts with, and when methylated on certain specific areas, can act to repress or activate gene expression. In this abstract, the authors describe the use of cultured mouse neurons to examine the MeCP2-regulated changes in histone methylation, in early neuron development. Here, the authors discuss distinct changes in the levels of histone methylation. Ongoing experiments will look at these changes at RTT genes of interest (Bdnf, Dlx5) in both Mecp2-deficient and non-affected neurons. Dr. Akbarian got started in RTT research with an RSRF award and was able to leverage those funds into a much larger NIH grant.