Study On The Mechanism Of Wheat Germ Peptide Delaying Senile Osteoporosis

Senile osteoporosis is a kind of primary osteoporosis closely related to oxidative stress.A large number of studies have shown that reducing the level of oxidative stress can effectively improve senile osteoporosis.Wheat germ peptide ADWGGPLPH is a natural bioactive peptide.Previous studies in our group showed that ADWGGPLPH effectively reduced the level of oxidative stress,but its effect on senile osteoporosis and underlying mechanism are not clear.In this study,we established an oxidative stress model using osteoblast-osteoclast(OB-OC)co-culture system.The aged rats were used to study the effect of wheat germ peptide on delaying senile osteoporosis and underlying mechanism.The main results are as follows:(1)The oxidative stress model induced by H₂O₂was established using the OB-OC co-culture system.The effects of wheat germ peptide on the proliferation and apoptosis of osteoblast under oxidative stress were measured by flow cytometry,MTT proliferation test,FITC/PI double staining and other methods.The results showed that wheat germ peptide ADWGGPLPH can effectively promote the proliferation of osteoblast and inhibit the apoptosis of osteoblast in the co-culture system.The effects of wheat germ peptide on the differentiation of osteoblast and osteoclast under oxidative stress were studied by alkaline phosphatase(ALP)activity assay,enzyme linked immunosorbent assay(ELISA),tartrate-resistant acid phosphatase(TRAP)staining and other methods.The results showed that wheat germ peptide ADWGGPLPH can effectively improve the differentiation of osteoblast and inhibit the differentiation of osteoclast in the co-culture system.(2)The natural aging rats were used as the animal model of senile osteoporosis.The wheat germ peptide was injected into mice from 9 months to 21months.Serum biochemical indexes,bone histomorphometry,bone biomechanics and other indexes were determined to evaluate the effect of wheat germ peptide on osteoporosis in senile rats.The results showed that wheat germ peptide ADWGGPLPH could effectively reduced the oxidative stress level of serum and bone tissue,and improved bone microstructure and bone density of aged rats,which indicated that wheat germ peptide was effective in delaying osteoporosis in the elderly.(3)Based on in vivo and in vitro models,the expression of osteoporosis-related proteins was determined to clarify the mechanism by which wheat germ peptide delaysenile osteoporosis.The results showed that wheat germ peptide ADWGGPLPH could not only promote the expression of proliferating protein Ki67,differentiation protein type I collagen(Col-I)and osteocalcin(OCN),but also inhibit the expression of apoptotic protein Bax/Bcl-2 in aging rat femoral osteoblast.In addition,wheat germ peptide ADWGGPLPH can inhibit the expression of osteoblast nuclear factor kappa B receptor activator ligand(RANKL)and receptor nuclear factor kappa B receptor activator(RANK)in osteoclast membrane by regulating tumor necrosis factor receptor-associated protein 6(TRAF6)pathway in the femur of aging rats.It can promote the expression of the decoy receptor osteoprotectin(OPG)in osteoblast,thereby inhibiting the differentiation of osteoclast and delaying the development of senile osteoporosis.In conclusion,the study proved that wheat germ peptide ADWGGPLPH can inhibit the apoptosis of osteoblast,promote proliferation and differentiation of osteoblast and inhibit differentiation of osteoclast by regulating TRAF6 related pathway under oxidative stress to delay senile osteoporosis,thereby providing scientific evidence for the effective treatment of osteoporosis.