Activation of NADPH oxidases leads to DNA damage in esophageal cells

Cartilage injury induced by acute excessive contact stress is common and mostly afects young adult. Although early detection of cartilage injury may prevent serious and lifelong arthritic complications, early detection and treatment is not possible due to the lack of a reliable detection method. Since chondrocyte injury and subsequent cell death are the early signs of cartilage injury, it is likely that cartilage cell apoptosis can be used to predict the extent of injury. To test this hypothesis, a near infrared probe was fabricated to have high afnity to apoptotic cells. In vitro tests show that this apoptosis probe has low toxicity, high specifcity, and high afnity to apoptotic cells. In addition, there is a positive relationship between apoptotic cell numbers and fuorescence intensities. Using a mouse xiphoid injury model, we found signifcant accumulation of the apoptosis probes at the injured xiphoid cartilage site. There was also a positive correlation between probe accumulation and the number of apoptotic chondrocytes within the injured xiphoid cartilage, which was confrmed by TUNEL assay. The results support that the apoptosis probes may serve as a powerful tool to monitor the extent of mechanical force-induced cartilage injury in vivo.