1405 Cellular and molecular characterization of sebaceous gland self-renewal and regeneration following complete genetic ablation

Sebaceous glands (SG) produce and secrete lipids onto the skin surface to protect it from dehydration harmful pathogens. Peroxisome proliferator-activated receptor-gamma (PPARg) is a member of nuclear receptor family ligand-activated transcription factors that critical for SG formation. Here, we report PPARg initially expressed within transitional basal cells in progenitor compartment. Lineage tracing PPARg-expressing their progeny revealed SGs are maintained independently hair follicle during homeostasis. Upon wounding, however, exit gland, contribute reepithelization, replaced by follicle-derived cells. Targeted single cell RNA-sequencing (scRNA-seq) on sorted uncovered both direct indirect paths which progenitors differentiate into sebocytes. Furthermore, our scRNA-seq analyses identified 3 putative sebocyte states, including early late Finally, deleted adult skin, caused rapid disappearance SGs. Surprisingly, most regenerated 5-10 weeks after initial deletion. This regenerative process was highly dependent cycle FGFR signaling. In summary, studies illuminate intricate cellular interplay governs behavior homeostasis, injury regeneration.