Hair follicle stem cells sense niche integrity and recruit immune cells to contain barrier breaches

We demonstrated that hair follicle stem cells (HFSCs) are able to sense the integrity of their epithelial niche. By ablating a core cell junction component E-cadherin (encoded by Cdh1), the epithelial niche no longer maintains proper barrier function, leading to microbial infiltration through the hair follicle. The surrounding HFSCs respond by increasing its expression of immune associated genes and recruiting immune cells to their niche so as to cope with compromised tissue function. Transcriptomes of hair follicle stem cells (HFSCs) FACS-purified from Cdh1 cKO and Het mice non-treated or treated with the immunosuppressant dexamethasone (Dex) were subjected to Ilumina HiSeq4000 next-generation sequencing. Transcriptomes of cells comprising the HFSC bulge niche were FACS-purified from Cdh1 cKO and Het mice and subjected to Ilumina HiSeq4000 next-generation sequencing.