Distinct mechanisms for sebaceous gland self-renewal and regeneration provide durability in response to injury

SUMMARY

Sebaceous glands (SGs) release oils that protect our skin, but how these glands respond to injury has not been previously examined. Here, we report that SGs are largely self-renewed by dedicated stem cell pools during homeostasis. Using targeted single-cell RNA sequencing, we uncovered both direct and indirect paths by which resident SG progenitors ordinarily differentiate into sebocytes, including transit through a Krt5+PPARγ+ transitional basal cell state. Upon skin injury, however, SG progenitors depart their niche, re-epithelialize the wound, and are replaced by hair-follicle-derived stem cells. Furthermore, following targeted genetic ablation of >99% of SGs from dorsal skin, these glands unexpectedly regenerate within weeks. This regenerative process is mediated by alternative stem cells originating from the hair follicle bulge, is dependent upon FGFR2 signaling, and can be accelerated by inducing hair growth. Altogether, our studies demonstrate that stem cell plasticity promotes SG durability following injury.

Graphical Abstract

In brief

Veniaminova et al. characterize the development, maintenance, and regeneration of sebaceous glands (SGs). Although SGs are largely self-maintained by dedicated stem cells during homeostasis, alternative stem cells enter and regenerate the gland following injury. This regenerative process relies on FGF signaling and can be accelerated by stimulating hair growth.