TGF-β signaling and collagen deposition in chronic rhinosinusitis

A high TGF-β 1 protein expression, increased TGF-β RI expression, and a high number of pSmad 2-positive cells all indicate an enhanced TGF-β signaling in CRSsNP, whereas a low TGF-β 1 protein concentration, a decreased expression of TGF-β RII, and a low number of pSmad 2-positive cells in CRSwNP indicate a low level of TGF-β signaling in CRSwNP. These findings are compatible with the remodeling patterns observed, reflected by a lack of collagen in CRSwNP, and excessive collagen production with thickening of the collagen fibers in the extracellular matrix in CRSsNP.