Temporal Layering of Signaling Effectors Drives Chromatin Remodeling during Hair Follicle Stem Cell Lineage Progression.

Publication Type Academic Article
Authors Adam R, Yang H, Ge Y, Lien W, Wang P, Zhao Y, Polak L, Levorse J, Baksh S, Zheng D, Fuchs E
Journal Cell Stem Cell
Volume 22
Issue 3
Pagination 398-413.e7
Date Published 01/11/2018
ISSN 1875-9777
Keywords Cell Lineage, Chromatin Assembly and Disassembly, Hair Follicle, Signal Transduction, Stem Cells
Abstract Tissue regeneration relies on resident stem cells (SCs), whose activity and lineage choices are influenced by the microenvironment. Exploiting the synchronized, cyclical bouts of tissue regeneration in hair follicles (HFs), we investigate how microenvironment dynamics shape the emergence of stem cell lineages. Employing epigenetic and ChIP-seq profiling, we uncover how signal-dependent transcription factors couple spatiotemporal cues to chromatin dynamics, thereby choreographing stem cell lineages. Using enhancer-driven reporters, mutagenesis, and genetics, we show that simultaneous BMP-inhibitory and WNT signals set the stage for lineage choices by establishing chromatin platforms permissive for diversification. Mechanistically, when binding of BMP effector pSMAD1 is relieved, enhancers driving HF-stem cell master regulators are silenced. Concomitantly, multipotent, lineage-fated enhancers silent in HF-stem cells become activated by exchanging WNT effectors TCF3/4 for LEF1. Throughout regeneration, lineage enhancers continue reliance upon LEF1 but then achieve specificity by accommodating additional incoming signaling effectors. Barriers to progenitor plasticity increase when diverse, signal-sensitive transcription factors shape LEF1-regulated enhancer dynamics.
DOI 10.1016/j.stem.2017.12.004
PubMed ID 29337183
PubMed Central ID PMC6425486
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