Adenosine Stimulates Fibroblast Growth Factor-7 Gene Expression Via Adenosine A2b Receptor Signaling in Dermal Papilla Cells

This study demonstrated that adenosine stimulated fibroblast growth factor-7 (FGF-7) gene expression in dermal papilla cells (DPCs) via the A2b adenosine receptor, with a greater than 2-fold increase in FGF-7 mRNA and protein levels. The upregulation was inhibited by the A2b receptor-specific antagonist alloxazine, but not by antagonists for other subtypes. Adenosine also increased intracellular cAMP levels in a dose-dependent manner, which further augmented FGF-7 upregulation. Additionally, FGF-7 treatment at concentrations of 10 ng/ml or greater significantly stimulated hair fiber elongation in human scalp hair follicle organ cultures, suggesting that adenosine might promote hair growth through FGF-7 upregulation in DPCs.