GSE125806
Mechanical stretch induces hair regeneration through the alternative activation of macrophages
Tissues and cells in organism are continuously exposed to a complicated set of mechanical cues from the environment. Mechanical stimulations affect cell proliferation, differentiation, migration, and determine tissue homeostasis as well as repair. By using a specially designed skin-stretching device, we discover hair stem cells proliferate in response to stretch and hair regeneration occurs only when proper strain and duration were delivered. Counterbalance between WNT and BMP-2 followed by a two-step mechanism was identified through molecular and genetic analyses. Macrophages were first recruited by chemokines elicited by stretch and polarized to M2 phenotype. Growth factors such as HGF and IGF-1 released by M2 macrophages then activated hair stem cells and facilitate hair regeneration. Collectively, a hierarchical control from mechanics, chemical signals, cell behaviors, to tissue responses was revealed. This novel finding shed new light on regenerative medicine and disease control since one can manipulate cellular processes through simple mechanical stimulation. Overall design: By using a specially designed skin-stretching device to discover the hair stem cells biological process and hair regeneration mechanism.