Regulation of energy metabolism in the growth plate and osteoarthritic chondrocytes.

Osteoarthritis (OA) is a chronic disorder associated mainly with pain, limited range of motion, stiffness, low-grade systemic inflammation, and articular cartilage destruction. Recent studies have demonstrated the involvement of chondrocyte differentiation (hypertrophy) as one of the mechanisms in cartilage degradation in OA. This implicates the involvement of principal changes in the regulation of cellular function associated with profound alterations in chondrocyte energy metabolism in the course of cartilage resorption. Therefore, this review describes the major energy-generating pathways and their regulatory molecules used by the growth plate chondrocytes during endochondral ossification and by articular chondrocytes in OA. These regulatory molecules facilitate either the glycolytic pathway of energy generation, which controls cell proliferation, or mitochondrial oxidative phosphorylation promoted by AMPK and sirtuins and responsible for tissue regeneration. Consideration of the disturbances in energy metabolic pathways associated with OA might provide an approach to disclose the primary causes of the disease's development and progression. Medline/PubMed was searched for publications in English using key words: osteoarthritis, epiphyseal growth plate, articular cartilage, glycolysis, oxidative phosphorylation, and regulation of energy metabolism.