@entity1 express three distinct collagenases, @entity3334 , @entity5952 , and @entity1550 , that initiate degradation of fibrillar type I collagen. We have previously reported that ultraviolet irradiation causes increased expression of @entity3334 , but not @entity1550 , in keratinocytes and fibroblasts in @entity1 skin in vivo. We report here that ultraviolet irradiation increases expression of @entity5952 in @entity1 skin in vivo. Western analysis revealed that levels of the full-length, 85 kDa proenzyme form of @entity5952 increased significantly within 8 h post ultraviolet irradiation (2 minimal erythema doses). Increased full-length @entity5952 protein was associated with infiltration into the skin of neutrophils, which are the major cell type that expresses @entity5952 . Immunofluorescence revealed coexpression of @entity5952 and neutrophil elastase, a marker for neutrophils. Immunohistology demonstrated @entity5952 expression in neutrophils in the papillary dermis between 4 and 8 h post ultraviolet irradiation, and in the epidermis at 24 h post radiation. @entity5952 mRNA expression was not detected in nonirradiated or ultraviolet-irradiated @entity1 skin, indicating that increased @entity5952 following ultraviolet irradiation resulted from preexisting @entity5952 protein in infiltrating neutrophils. Pretreatment of skin with the glucocorticoid @entity6914 , but not @entity1968 , significantly blocked ultraviolet-induced increases in @entity5952 protein levels, and neutrophil infiltration. In contrast, @entity1968 and @entity6914 were equally effective in blocking ultraviolet induction of @entity3334 and degradation of collagen in @entity1 skin in vivo. Taken together, these data demonstrate that ultraviolet irradiation increases @entity5952 protein, which exists predominantly in a latent form within neutrophils, in @entity1 skin in vivo. Although ultraviolet irradiation induces both @entity3334 and @entity5952 , ultraviolet-induced collagen degradation is initiated primarily by @entity3334 , with little, if any, contribution by @entity5952 .

Ultraviolet irradiation increases matrix metalloproteinase-8 protein in XXXX skin in vivo.

@entity1 :: ('9606', 'Species') :: ['human', 'Humans'] @entity3334 :: ('4312', 'Gene') :: ['MMP-1'] @entity1550 :: ('4322', 'Gene') :: ['MMP-13'] @entity6914 :: ('MESH:D002990', 'Chemical') :: ['clobetasol'] @entity5952 :: ('4317', 'Gene') :: ['MMP-8'] @entity1968 :: ('MESH:D014212', 'Chemical') :: ['all-trans retinoic acid']
@entity1 :: (9606,Species) :: ['human']
