Alterations of Proteoglycans in Ultraviolet‐irradiated Skin

Abstract

The effect of UVB exposure on the distribution and synthesis of dermal proteoglycans was measured in the skin of hairless mice. Two groups of mice were included: one was irradiated for 10 weeks; the other was kept as control. After intraperitoneal injection of sodium 35-S-sulfate, punch biopsies were taken for histology and proteoglycans were extracted from the remaining skin with 4 M guanidinium chloride, containing 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (0.5%, weight per volume). Following proteolytic digestion, the glycosaminoglycan constituents were isolated and analyzed by quantitative cellulose acetate electrophoresis and enzymatic digestibility. Under the influence of UVB radiation, newly synthesized proteoglycans measured by 35SO4 uptake increased as much as 60%. In addition, the irradiated skin had a higher average content of proteoglycan than had control skin (4981 micrograms vs 4134 micrograms/g dry weight). This could be ascribed to an increase in heparin (1400 vs 533 micrograms/g dry weight) and heparan sulfate (472 vs 367 micrograms/g dry weight), whereas no change in the concentration of hyaluronic acid (1243 vs 1372 micrograms/g dry weight) and dermatan sulfate (1866 vs 1863 micrograms/g dry weight) was observed. The irradiated animals also exhibited a marked increase in the synthesis of heparan sulfate and heparin (62% and 71%, respectively). These results demonstrate that chronic doses of UVB altered proteoglycan metabolism through both quantitative and qualitative changes.

Topical Tretinoin Increases the Tropoelastin and Fibronectin Content of Photoaged Hairless Mouse Skin

“…In agreement with onr findings on tbe effect of UVR alone, Margelin et al [33] found increased glycosaminoglycan synthesis in explants from UV-inadiated hairless mice. However, the increase was seen only in the proteoglycans beparin and heparan sulfate.…”

Acute UV Irradiation Increases Heparan Sulfate Proteoglycan Levels in Human Skin

“…Chronically UVB-irradiated hairless mouse skin was observed to contain and produce increased HS and heparin proteoglycans (18). In contrast, Iriyama et al (17) reported that HS staining in the dermal-epidermal junction was decreased in acute UVB-irradiated buttock skin, while perlecan core protein and total HS staining did not change, probably through induction of heparanase activity by UV irradiation.…”

Tobacco smoke causes premature skin aging

“…On the other hand, staining for decorin is faint in young rats and distinct in old rats [35]. There are several reports concerning the changes in proteoglycan levels in photoaging, especially UVB irradiation [36,37]. UVB radiation markedly increases proteoglycan synthesis in mice [36].…”

“…There are several reports concerning the changes in proteoglycan levels in photoaging, especially UVB irradiation [36,37]. UVB radiation markedly increases proteoglycan synthesis in mice [36]. Versican and decorin immunostaining is increased in photoaged tissue samples accompanied by similar alterations in gene expression [37].…”