mTOR Signaling Promotes Stem Cell Activation via Counterbalancing BMP-Mediated Suppression During Hair Regeneration
January 2015
in “
Journal of molecular cell biology/Journal of Molecular Cell Biology
”
TLDR mTOR signaling helps activate hair stem cells by balancing out the suppression caused by BMP during hair growth.
The study revealed that mTOR complex 1 (mTORC1) signaling plays a crucial role in the activation of hair follicle stem cells (HFSCs) during the transition from the resting phase (telogen) to the regeneration phase (anagen) of hair follicles. The researchers used gene targeting and pharmacological inhibition to show that hair follicles unable to respond to mTOR signaling had delayed HFSC activation and an extended resting phase. They found that mTORC1 signaling negatively regulates BMP signaling, which is a suppressive signal for HFSC activation. The study also demonstrated that inhibiting BMP signaling with its antagonist Noggin could rescue the activation defect in HFSCs lacking mTORC1 signaling. This indicates that mTORC1 facilitates HFSC activation by counteracting BMP-mediated suppression during hair regeneration.