Mitochondrial dysfunction plays a key role in premature musculoskeletal aging in hypochondroplasia mouse model

Abstract

Hypochondroplasia (HCH) is a mild form of chondrodysplasia, caused by variants in fibroblast growth factor receptor 3 (FGFR3). Today, the biological mechanism underlying musculoskeletal aging in HCH remains largely unknown. In this study, we show that Hch mice exhibit phenotypic traits of bone fragility and accelerated age-dependent articular cartilage and subchondral bone changes. Hch mice also presented decreased muscle strength and reduction in muscle fibers size. Furthermore, proteomics analyses of the cortical bone revealed that Hch mice follow a different aging trajectory than control. FGFR3 mutation leads to a premature boost of the mitochondrial processes forcing the mutant to reach a physiological state much earlier than the control. Together, these findings demonstrate that aging in Hch mice is accompanied by bone fragility and osteoarthritis-like changes. Proteomics analyses highlighted the key role for mitochondria in the cortical bone of Hch mice, providing insight into the mechanisms underlying premature aging in HCH.