Effects of H2O2 Derived Hydroxyl Radicals Treated Fibronectin on Rat Calvarial Osteoblast

Shin, Sang Jin; Kang, Eung Shick; Kim, Sung Jae

Abstract

Fibronectin is involved in various cellular activities such as adhesion, proliferation and migration as a substratum. Since the metabolic turnover of fibronectin is much slower than other cellular components, it may be affected by the oxygen free radicals produced in the aging process. Hydroxyl radicals are known to be generated during inflammation and aging process. The purpose of this study is to investigate the influence of fibronectin treated with hydroxyl radicals generated by the H2O2-Cu2+ systems on osteoblast. The bone nodule formation, alkaline phosphatase activity, cell proliferation study and secretion of type I collagen were compared among non-coated, fibronectin-coated and hydroxyl radical treated fibronectin-coated groups. SDS-PAGE and Western blot analysis showed that fibronectin was degradated with hydroxyl radical treatment. The bone nodule formation in the fibronectin-coated group was significantly greater than that in non-coated or hydroxyl radical treated fibronectin-coated group. Alkaline phosphatase activity and cell proliferation were reduced in hydrokyl radical treated fibronectin coated group. In hydrosyl radical treated fibronectin-coated group, mRNA level of type I collagen by RT-PCR was also decreased. This study suggested that fibronectin played important roles in osteoblast activity and fibronectin damaged by the hydrokyl radicals reduced the bone formation of osteoblast through the inhibition of cell proliferation, differentiation and calcification processed.