Does quorum sensing rely on Fgf9 and shh-gli signaling? Does minoxidil provide those? Not disagreeing, I just don't know. I think the quorum sensing is the newest puzzle piece for wounding?
No, it doesn't, but quorum sensing is just part of it.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5135642/
"Further testing demonstrated that quorum sensing in the skin was mediated by an immune cascade in which plucking injury induced the release of CCL2 which then recruited TNF-α-secreting macrophages to hone toward plucked hair follicles and their unplucked neighbors. TNF-α then stimulates the NF-κB pathway to increase Wnt signaling activating stem cells to induce hair regeneration"
Without fgf9 Wnt signalling is limited:
https://www.ncbi.nlm.nih.gov/pubmed/23727932
"Here we show that fibroblast growth factor 9 (Fgf9), initially secreted by γδ T cells, modulates hair follicle regeneration after wounding the skin of adult mice. Reducing Fgf9 expression decreases this wound-induced hair neogenesis (WIHN). Conversely, overexpression of Fgf9 results in a two- to threefold increase in the number of neogenic hair follicles. We found that Fgf9 from γδ T cells triggers Wnt expression and subsequent Wnt activation in wound fibroblasts."
Wnt signalling alone is not enough:
https://www.ncbi.nlm.nih.gov/pubmed/30464171
"While long-term Wnt activation is associated with fibrosis, Shh signal activation in Wnt active cells promotes the dermal papilla fate in scarring wounds. These studies demonstrate that mechanisms of scarring and regeneration are not distant from one another and that wound repair can be redirected to promote regeneration following injury by modifying a key dermal signal."
