MBD1 belongs to a family of methyl-CpG binding proteins that are epigenetic “readers”, linking DNA methylation to transcriptional regulation. MBD1 is expressed in neural stem cells residing in the dentate gyrus of the adult hippocampus (aNSCs), and MBD1 deficiency leads to reduced neuronal differentiation, impaired neurogenesis, learning deficits, and autism-like behaviors in mice; however the precise function of MBD1 in aNSCs remains unexplored. Here, we show that MBD1 is important for maintaining the integrity and stemness of NSCs, which is critical for their ability to generate neurons. MBD1 deficiency leads to the accumulation of undifferentiated NSCs and impaired transition into the neuronal lineage. Transcriptome analysis of neural stem and progenitor cells directly isolated from the dentate gyrus of MBD1 mutant (KO) and wild type (WT) mice showed that gene sets related to cell differentiation, particularly astrocyte lineage genes, were upregulated in KO cells. We further demonstrated that in NSCs, MBD1 directly binds and represses specific genes associated with differentiation. Our results suggest that MBD1 maintains the multipotency of NSCs by restraining the onset of differentiation genes and that untimely expression of these genes in MBD1-deficient stem cells may interfere with normal cell lineage commitment and cause the accumulation of undifferentiated cells. Our data reveal a novel role for MBD1 in stem cell maintenance and provide insight into how epigenetic regulation contributes to adult neurogenesis and the potential impact of its dysregulation.
Adult neural stem cells (aNSCs) in the hippocampus self-renew and generate neurons throughout life. We show that MBD1, a DNA methylation “reader”, is important for maintaining the integrity of NSCs, which is critical for their neurogenic potency. Our data reveal a novel role for MBD1 in stem cell maintenance and provide insight into how epigenetic regulation preserves the multipotency of stem cells for subsequent differentiation.
The authors declare no competing financial interests.
We would like thank Maggie Caulkins and Yina Xing for technical assistance, Natalie Patzlaff and Matthew Doers for editing, Karen Ersland, Dagna Sheerar, and Faye Bruggink at the UWCCC Flow Cytometry Laboratory for cell sorting assistance, Sandra Splinter BonDurant at the University of Wisconsin-Madison Biotechnology Center for library preparation and sequencing advisement, Karla Knobel at the Waisman Cell and Molecular Neuroscience Core, and Jason Pinnow, Dawna Bollig, Megan Eastwood at the Waisman Rodent Models Core. This work was supported by grants from the NIH to X. Z. (RO1MH080434, RO1MH07897, R21NS095632), grants from the NIH to the Waisman Center (P30HD03352; U54 HD090256), a NIH Molecular Biosciences Training Grant to E.M.J (MBTG: T32GM07215), NIH NRSA to B.E.E. (F32NS094120), a UW Hilldale Undergraduate Research Fellowship to L.E.K.