Autophagy in osteoporosis: Relation to oxidative stress

Impaired autophagy and oxidative stress are implicated in the development of many diseases. This study aimed to investigate the involvement of autophagy represented by autophagy-related gene 7 (Atg7) and oxidative stress represented by superoxide dismutase 2 (SOD2) gene expression and enzyme activity in the pathogenesis of osteoporosis. Atg7 and SOD2 gene relative expression were evaluated by SYBR green quantitative real-time-polymerase chain reaction in the osteoporotic group (n = 26) versus the osteoporosis free group (n = 14). SOD2 enzyme activity was evaluated by colorimetric method in both study groups. Both Atg7 and SOD2 relative expression showed highly significant decrease (P < 0.01) between both groups. However, SOD2 enzyme activity showed no significant difference between the two groups. There was a significant direct correlation between Atg7 and SOD2 gene expression in both study groups. Atg7 relative expression showed significant ( P < 0.01) direct correlation with vitamin D serum levels and body mass index in osteoporotic group. In conclusion, both genes are involved in the pathogenesis of osteoporosis and this could be amenable to future therapeutic intervention.