Aberrant Wnt Signaling Induces Comedo-Like Changes in the Upper Hair Follicle

The study, conducted 3 years ago, explored the role of Wnt signalling in the formation of comedonal acne, a skin disease characterized by cystic dilation of the hair follicle junctional zone. The researchers used an Lrig1-CreERT2 mouse line to modulate Wnt signalling in stem cells of the junctional zone. They found that persistent activation of Wnt signalling led to the formation of comedone-like cysts with associated atrophic sebaceous glands. These cysts strongly expressed stem cell markers and could be partially reduced by treatment with all-trans retinoic acid, a well-established acne treatment, and by inhibition of Hedgehog signalling. Conversely, loss of Wnt signalling led to enlargement of the junctional zone, infundibulum, and sebaceous glands. The data suggested that abnormal Wnt signalling could be involved in acne pathogenesis by inhibiting differentiation and retaining junctional zone cells in a proliferative progenitor state, leading to their accumulation into comedones.