IADR Abstract Archives
Hypoxia-induced ROS Contribute to Myoblast Pyroptosis Dduring Obstructive Sleep Apnea via the NF-κB/HIF-1α Signaling Pathway
Objectives: Tissue hypoxia caused by upper airway collapse is a main cause of excessive oxidative stress and systemic inflammation in obstructive sleep apnea (OSA) patients. Increased reactive oxygen species (ROS) and inflammatory responses affect cell survival and ultimately contribute to tissue injury. In the present study, we proposed that the induction of ROS by hypoxia, as an intrinsic stress, activates myoblast pyroptosis in OSA.
Methods: In vivo study, seletal muscle tissues from OSA and control mice were tested for pyrotosis-related genes and proteins. In vitro study, cobalt chloride (CoCl2) was used to mimic hypoxia in this study. Cultured C2C12 cells were treated with or without CoCl2. Real-time PCR and western blotting analysis were applied to compare the difference of pyrotosis-related genes and proteins between the control cells and CoCl2-induced cells.
Results: We found increased cell death and abnormal expression of pyroptosis markers in the skeletal muscle of OSA mice. In vitro studies showed hypoxia-induced pyroptotic death of C2C12 myoblasts, as evidenced by the activation of caspase-1 and gasdermin D (GSDMD). Hypoxia induced ROS overproduction and accumulation in myoblasts. More importantly, applying N-acetylcysteine (NAC), an ROS scavenger, rescued cell swelling, downregulated the inflammatory response, and prevented pyroptotic death in hypoxia-cultured myoblasts. Hypoxia stimulation promoted NF-κB P65 phosphorylation and HIF-1α nuclear translocation. Moreover, hypoxia increased the nuclear level of cleaved caspase-1 and GSDMD. NAC inhibited hypoxia-induced variations in the HIF-1α and NF-κB signaling pathway.
Conclusions: Taken together, our results determined that hypoxia-induced ROS contribute to myoblast pyroptosis. Therefore, our findings suggest that ROS may be a potential therapeutic target for ameliorating hypoxia-induced cell death and tissue injury, especially in OSA and hypoxia-related diseases.
Methods: In vivo study, seletal muscle tissues from OSA and control mice were tested for pyrotosis-related genes and proteins. In vitro study, cobalt chloride (CoCl2) was used to mimic hypoxia in this study. Cultured C2C12 cells were treated with or without CoCl2. Real-time PCR and western blotting analysis were applied to compare the difference of pyrotosis-related genes and proteins between the control cells and CoCl2-induced cells.
Results: We found increased cell death and abnormal expression of pyroptosis markers in the skeletal muscle of OSA mice. In vitro studies showed hypoxia-induced pyroptotic death of C2C12 myoblasts, as evidenced by the activation of caspase-1 and gasdermin D (GSDMD). Hypoxia induced ROS overproduction and accumulation in myoblasts. More importantly, applying N-acetylcysteine (NAC), an ROS scavenger, rescued cell swelling, downregulated the inflammatory response, and prevented pyroptotic death in hypoxia-cultured myoblasts. Hypoxia stimulation promoted NF-κB P65 phosphorylation and HIF-1α nuclear translocation. Moreover, hypoxia increased the nuclear level of cleaved caspase-1 and GSDMD. NAC inhibited hypoxia-induced variations in the HIF-1α and NF-κB signaling pathway.
Conclusions: Taken together, our results determined that hypoxia-induced ROS contribute to myoblast pyroptosis. Therefore, our findings suggest that ROS may be a potential therapeutic target for ameliorating hypoxia-induced cell death and tissue injury, especially in OSA and hypoxia-related diseases.