Cytokines and Growth Factors Influence Hair Growth In Vitro: Possible Implications for the Pathogenesis and Treatment of Alopecia Areata

The study investigated the role of cytokines and growth factors in hair growth using in vitro cultures of human hair follicles. It found that certain cytokines, such as IL-2, IL-10, and IFN-γ, did not affect hair growth, while TGFβ1 partially inhibited it. EGF, TNFα, and IL-1β completely halted hair growth, with EGF and TNFα inducing a catagen-like morphology in hair follicles. The research suggested that cytokines and growth factors were crucial regulators of hair growth in vitro and highlighted IL-1's potential role in the pathogenesis of alopecia areata (AA). The study also noted that therapeutic mediators like IL-10, TGFβ1, TNFα, and PGE2 did not counteract IL-1β-induced hair growth inhibition, implying they modulated the immune response in AA rather than directly reversing hair growth inhibition.