A close relationship between type 1 diabetes and vitamin A-deficiency and matrix metalloproteinase and hyaluronidase activities in skin tissues.

Numerous wrinkles are observed in the skin of streptozotocin (STZ)-induced type 1 diabetic rats, which are similar to those seen in vitamin A-deficient (VAD) rats. Retinoic acid (RA), the active form of vitamin A, promotes the production of collagen in dermis and induces cell growth and inhibition of epidermal differentiation in skin tissues. Normal skin function is maintained by the extracellular matrix (ECM)-degrading enzymes, matrix metalloproteinase (MMP) and hyaluronidase (HAase). This study is the first comparison of MMP and HAase activities in skin tissues of type 1 diabetic, VAD and RA-treated animal models. In skin tissues of type 1 diabetic and VAD rats or VAD mice, both MMP-2 and HAase activities increased as compared with controls. In contrast, MMP and HAase activities were reduced in the skin tissues of RA-treated mice. Blood retinol levels in type 1 diabetic rats were lower than controls. These results indicate a close relationship between type 1 diabetes and vitamin A-deficiency on MMP and HAase in skin tissues, suggesting that type 1 diabetic rats could be vitamin A-deficient. Vitamin A-derived RA might be a significant regulator of ECM-degrading enzyme expression and diabetic symptoms.