Cell. 2015 Apr 9;161(2):277-90. doi: 10.1016/j.cell.2015.02.016.
Organ-level quorum sensing directs regeneration in hair stem cell populations.
Chen CC1, Wang L2, Plikus MV3, Jiang TX4, Murray PJ5, Ramos R3, Guerrero-Juarez CF3, Hughes MW6, Lee OK7, Shi S8, Widelitz RB4, Lander AD9, Chuong CM10.
Coordinated organ behavior is crucial for an effective response to environmental stimuli. By studying regeneration of hair follicles in response to patterned hair plucking, we demonstrate that organ-level quorum sensing allows coordinated responses to skin injury. Plucking hair at different densities leads to a regeneration of up to five times more neighboring, unplucked resting hairs, indicating activation of a collective decision-making process. Through data modeling, the range of the quorum signal was estimated to be on the order of 1 mm, greater than expected for a diffusible molecular cue. Molecular and genetic analysis uncovered a two-step mechanism, where release of CCL2 from injured hairs leads to recruitment of TNF-?-secreting macrophages, which accumulate and signal to both plucked and unplucked follicles. By coupling immune response with regeneration, this mechanism allows skin to respond predictably to distress, disregarding mild injury, while meeting stronger injury with full-scale cooperative activation of stem cells.
I have not personally seen such responses, but I will reach out to my colleagues and ask for their opinions. I already had a response from Dr. Bernstein in New York when asked about pucking, said: “No… I’ve been plucking for years – and look where it got me.” Dr. Bernstain has a Class 6 balding pattern as you can see on his informative hair restoration site here: https://www.bernsteinmedical.com/