Could Aging Human Skin Use a Connective Tissue Growth Factor Boost to Increase Collagen Content?

The roles of connective tissue growth factor (CTGF) and transforming growth factor-β (TGF-β), both well-known collagen production stimulators, were examined in skin aging. Aged skin and fibroblasts exhibited a coordinate decrease in CTGF, TGF-β, and type I procollagen expression and content. CTGF knockdown and TGF-β blockade in normal dermal fibroblasts reduced procollagen expression, whereas overexpressing CTGF increased procollagen by a TGF-β/Smad signaling–dependent mechanism without involving Smad2/3.