PROJECT SUMMARY Mitochondria, essential cellular organelles, are increasingly recognized for their central role in human health. Beyond their canonical function in energy production, mitochondria are implicated in diverse cellular processes, influencing metabolism, apoptosis, and signaling pathways. Dysregulation of mitochondrial dynamics has been implicated in a spectrum ranging from neurodegenerative disorders and metabolic syndromes to muscle-related disorders and aging, highlighting the multifaceted impact of mitochondria on human health. Recent studies have established the crucial roles of the evolutionarily conserved aldehyde dehydrogenase enzyme ALH-6/ALDH4A1 and the cytoprotective transcription factor SKN-1/NRF2 in mediating responses to mitochondrial stress. Significantly, C. elegans mutants encoding single amino acid mutations in the alh-6 gene developed mitochondria- and muscle-related dysfunction earlier than the normal counterparts, and the SKN-1/NRF2 stress response is activated to curtail cellular dysfunction. Our investigation builds upon established knowledge of alh- 6 mutations in Caenorhabditis elegans, which induce premature aging, impaired muscle function, and mitochondrial abnormalities. The project's intellectual significance lies in unraveling the cell autonomous and non-autonomous functions of mitochondrial health, specifically mitochondrial amino acid metabolism, and deciphering its impact on muscle-mitochondrial dynamics. My preliminary findings suggest the potential to decouple lifespan effects from other healthspan metrics in single tissues, offering a unique view of the impact of tissue-specific alh-6 rescues and its implications for overall organismal well-being. The proposed research investigates the role of mitochondrial proline catabolism, specifically the aldehyde dehydrogenase gene alh-6, in the context of muscle-mitochondrial health and its implications for overall organismal longevity. Thus, through meticulously designed aims, my first aim will employ innovative techniques, including CRISPR/Cas9-genetically edited tissue-specific rescues, single-cell RNA sequencing with 10x Genomics, and mitochondrial assessments, to comprehensively characterize alh-6 activity. This investigation delves into the molecular landscape of tissue-specific alh-6 rescues, offering insights into cellular heterogeneity and contributing to our understanding of how aberrations in mitochondrial proline catabolism impact muscle cells. My second aim will unravel the intricate inter-tissue coordination vital for maintaining mitochondrial health via mutagenesis screens, genetic mapping, and physiological analyses, seeking to identify and understand the specific molecular pathways transmitting signals to the body wall muscle. Together, my research aligns with human health relevance, as mitochondrial dysfunction is a hallmark of muscle-related diseases, including Sarcopenia and muscular dystrophy. By linking mitochondrial structure and functio...