Decision Letter: Hair Follicle Epidermal Stem Cells Define a Niche for Tactile Sensation

In 2018, a study was conducted to understand the role of compartmentalized epidermal stem cells in tactile sensory unit formation in the mouse hair follicle. The researchers found that these stem cells express a unique set of extracellular matrix (ECM) and neurogenesis-related genes and deposit an ECM protein called EGFL6 into the collar matrix. This protein was found to be required for the proper patterning, touch responses, and αv integrin-enrichment of lanceolate complexes. The study also found that EGFL6 knockout mice had misaligned and overlapping structures of axonal endings and terminal Schwann cell processes in their hair follicles, and exhibited defects in mechanical responses. Furthermore, the study discovered that the removal of a club hair led to changes in the lanceolate complex structure. The researchers concluded that the formation and preservation of the old bulge provides a stable epidermal-neuronal interface and induces a lanceolate complex structure oriented toward the caudal side of the hair follicle.