Abstract Body: Background: Duchenne muscular dystrophy (DMD) cardiomyopathy is characterized by progressive cardiac dysfunction driven in part by oxidative stress. Emerging evidence in skeletal muscle suggests that alterations in the microtubule cytoskeleton can regulate reactive oxygen species (ROS) production through mechanosensitive pathways, including X-ROS signaling mediated by NADPH oxidase 2. However, the relationship between microtubule remodeling and ROS signaling in DMD cardiomyocytes remains poorly understood. We hypothesized that microtubule dynamics regulate ROS production through activation of the NADPH oxidase pathway.
Methods: Cardiomyocytes differentiated from Pluripotent stem cells WA07(Alias_H7) were used to investigate the role of microtubule dynamics in regulating oxidative stress. Microtubules dynamics were modulated using colchicine/paclitaxel and intracellular ROS levels were quantified using CM-H2DCFDA . To determine whether NADPH oxidases contribute to this response, cells were treated with an inhibitor of NOX2. In parallel, expression of NOX2 was examined in cardiac tissue from dystrophic and control hearts.
Results & Conclusion: Disruption of microtubules using colchicine significantly reduced intracellular ROS levels in cardiomyocytes. Combined inhibition of NOX2 and microtubule disruption resulted in a marked reduction in ROS, indicating that microtubule-dependent ROS production occurs primarily through a NOX2-mediated mechanism. Consistent with these findings, dystrophic hearts exhibited elevated NOX2 expression compared with controls, suggesting enhanced NADPH oxidase signaling in the disease state. These findings identify microtubule organization as a regulator of NOX2-dependent ROS production in cardiomyocytes. Targeting NOX2-mediated redox signaling may therefore represent a potential therapeutic strategy to mitigate exacerbation of cardiomyopathy in dystrophic hearts.