Stress regulation of neurotransmission

Project Summary The long-term goal of the proposed research is to identify the mechanisms by which bidirectional communication between the nervous system and the intestine regulates organism-wide responses to oxidative stress through regulated neuropeptide release. Oxidative stress plays a critical role in cognitive dysfunction and neuronal death associated with neurodegenerative diseases, but little is known about the physiological roles that reactive oxygen species play as signaling molecules in the brain. My laboratory uses the model C. elegans to study new signaling pathways that modulate neurotransmitter release. We have identified a role for hydrogen peroxide as a signaling molecule that positively regulates the secretion of specific neuropeptide-like proteins from dense core vesicles through sulfenylation of dense core vesicle (DCV) release factors. We found that the regulated release of these neuropeptides activates the antioxidant transcription factor SKN-1/Nrf2 in the intestine. Here we seek to uncover the molecular mechanisms by which hydrogen peroxide regulates DCV release, and how, in turn, neuropeptide signaling activates the antioxidant response. This study will reveal novel mechanisms underlying ROS regulation of DCV secretion and it will provide fundamental insights into how redox homeostasis is achieved through gut-brain signaling, and may therefore have direct relevance for the development of strategies to treat neurodegenerative diseases whose progression is associated with unregulated ROS signaling.