Figure 6.

Summary of potential mechanisms of action for GzmB in UV-irradiated skin. After UV irradiation, GzmB is expressed and released into the extracellular space by a number of cells (keratinocytes, mast cells). GzmB can cleave fibronectin to form fragments that increase the expression and release of MMPs from fibroblasts. GzmB cleavage of decorin renders collagen fibrils more susceptible to MMP-mediated degradation. Overall, there is a loss of collagen density and organization leading to a phenotype of aged skin.