Effect of OPG gene mutation on protein expression and biological activity in osteoporosis.

ABSTRACT: The effect of an osteoprotegerin (OPG) gene mutation was investigated on its protein expression and biological activity in osteoporosis. The pcDNA3.0-OPG plasmid or wild-type plasmid were transfected into HEK293 cells. Osteoclast tartrate-resistant acid phosphatase (TRAP) staining and counting were then performed, and the expression of genes related to osteoclast differentiation and activation were measured by RT-PCR. The wild-type or mutant-type OPG at concentrations of 0, 10, 20, 50 and 100 ng/ml were added respectively to RAW264.7 cells and incubated for 24 h. The viability of cells treated with the wild-type and mutant-type OPG at a concentration of 100 ng/ml was still over 99%, which indicated that the wild-type and mutant-type OPG at this concentration had no cytotoxic effect on RAW264.7 cells. The number of TRAP-positive cells decreased with increasing concentration of wild-type or mutant-type OPG. At the concentrations of 20, 50 and 100 ng/ml, the inhibitory effect of wild-type OPG was significantly higher than that of mutant-type OPG (p<0.05). Both mutant-type and wild-type OPG inhibited the bone resorption activity of osteoclasts, and the inhibitory effect of wild-type OPG was significantly higher than that of mutant-type OPG at the concentrations of 20, 50 and 100 ng/ml (p<0.05). The levels of TRAP and RANK mRNA in the wild-type OPG treatment group were significantly lower than those in the control group, while the levels of TRAP and RANK mRNA in the mutant-type OPG treatment group were significantly lower than those in the wild-type group (p<0.05). The genetic mutation did not affect the protein expression levels of OPG, but inhibited the normal activity of OPG.

SUBMITTER: Qin S 

PROVIDER: S-EPMC5526059 | biostudies-other | 2017 Aug

REPOSITORIES: biostudies-other