Pyrroloquinoline quinone prevents knee osteoarthritis by inhibiting oxidative stress and chondrocyte senescence.

Accumulating evidence suggests that oxidative stress plays an important role in the progression of osteoarthritis (OA), and pyrroloquinoline quinone (PQQ) is considered a strong antioxidant. However, it is unclear whether PQQ can prevent the progression of OA by inhibiting oxidative stress. In this study, anterior cruciate ligament transection (ACLT)-induced OA mice received a diet supplemented with/without PQQ, and were compared with each other and with sham-operated mice. Our results showed that in PQQ-untreated OA mice, articular surfaces collapsed, while the thickness of articular cartilage and the abundance of cartilage matrix protein decreased significantly, whereas PQQ supplementation largely prevented these alterations. We also found that oxidative stress, DNA damage, cellular senescence and the secretion of senescence-associated inflammatory cytokines were increased in PQQ-untreated OA mice compared with sham-operated mice. However, these parameters were obviously rescued in PQQ-treated OA mice. This study demonstrated that PQQ supplementation can prevent ACLT-induced OA by inhibiting oxidative stress, DNA damage, cell senescence and the development of the senescence-associated secretory phenotype.