TBBPA exposure causes cartilage cell damage in both in vitro and in vivo models

Tetrabromobisphenol A (TBBPA) is a widely used flame retardant. TBBPA is a persistent pollutant that is difficult to degrade and causes sustained pollution to the environment. TBBPA has been detected in human blood and tissues, and studies indicate it causes various toxicological damages to tissues and cells. To date, the toxicological effects of TBBPA on chondrocytes are not fully understood. Here, we evaluated the toxicological effects of TBBPA on chondrocytes and tissues. For this, human- and mouse-derived chondrocyte models were used to analyze the toxicological effects of TBBPA. Physiological concentrations of TBBPA were used to stimulate chondrocytes. Indirect immunofluorescence, flow cytometry, and biochemical assays were utilized to investigate TBBPA's toxicological impact on chondrocytes. The CCK8 experiment indicated that TBBPA reduced chondrocyte proliferation. ELISA and Western blot results indicated that TBBPA increased inflammatory factor expression in chondrocytes. We also found that TBBPA caused oxidative stress in chondrocytes. Mechanistic study showed that TBBPA triggered a imbalance in the homeostasis of calcium ions, leading to mitochondrial depolarization, which induces inflammation and oxidative stress of chondrocytes. In vivo model, our research showed that TBBPA caused inflammation in knee joint cartilage. Safranin O-Fast Green and H&E staining revealed cartilage tissue damage following TBBPA treatment. TBBPA increased MMP9 and MMP13 expression and down-regulated COL2 expression. In summary, we assessed TBBPA's impact on chondrocytes. The experimental data indicate that TBBPA causes damage to chondrocytes. This study establishes a basis for future research on the toxicological impacts of TBBPA.