Faculty Opinions Recommendation of Lrig1 Expression Defines a Distinct Multipotent Stem Cell Population in Mammalian Epidermis
TLDR Lrig1 marks a unique group of stem cells in mouse skin that can become different skin cell types.
In this study, Jensen et al. identified a distinct stem cell population in the mammalian epidermis marked by Lrig1 expression, located in the junctional zone of the hair follicle. This population was shown to have progenitor potential for all epidermal lineages, distinct from the bulge region stem cells. The study used knockout and inducible reporter mouse models to demonstrate that Lrig1 acts as a repressor of Myc, regulating epidermal proliferation and stem cell quiescence. Lrig1 expression was found to be transcriptionally activated by Myc, which is a beta catenin target, suggesting a complex regulatory mechanism involving these molecules. The findings highlighted the role of Lrig1 as a 'molecular brake' on stem cell activation and proliferation, with implications for understanding the regulation and development of epidermal stem cell populations.
