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Yen, C.-A.

Publications and source records attributed to Yen, C.-A..

2 recordsLinked to original sources

Genetic variation in ALDH4A1 predicts muscle health over the lifespan and across species

Environmental stress can negatively impact organismal aging, however, the long-term impact of endogenously derived reactive oxygen species from normal cellular metabolism remains less clear. Here we define the evolutionarily conserved mitochondrial enzyme ALH-6/ALDH4A1 as a biomarker for age-related changes in muscle health by combining C. elegans genetics and a gene-wide association study (GeneWAS) from aged human participants of the US Health and Retirement Study (HRS)1-4. In a screen for mutations that activate SKN-1-dependent oxidative stress responses in the muscle of C. elegans5-7, we identified 96 independent genetic mutants harboring loss-of-function alleles of alh-6, exclusively. These genetic mutations map across the ALH-6 polypeptide, which lead to age-dependent loss of muscle health. Intriguingly, genetic variants in ALDH4A1 differentially impact age-related muscle function in humans. Taken together, our work uncovers mitochondrial alh-6/ALDH4A1 as a critical component of normal muscle aging across species and a predictive biomarker for muscle health over the lifespan.

genetics↗

Loss of mitochondrial proline catabolism depletes FAD, impairing sperm function, and male reproductive advantage

Exposure to environmental stress is clinically established to influence male reproductive health, but the impact of normal cellular metabolism on sperm quality is less well-defined. Here we show that impaired mitochondrial proline catabolism, reduces energy-storing flavin adenine dinucleotide (FAD) levels, alters mitochondrial dynamics toward fusion, and leads to age-related loss of sperm quality (size and activity), which reduces competitive fitness. Loss of the 1-pyrroline-5-carboxylate dehydrogenase enzyme alh-6 that catalyzes the second step in mitochondrial proline catabolism, leads to premature male reproductive senescence. Reducing the expression of the proline catabolism enzyme alh-6 or FAD biosynthesis pathway genes in the germline is sufficient to recapitulate the sperm-related phenotypes observed in alh-6 loss-of-function mutants. These sperm-specific defects are suppressed by feeding diets that restore FAD levels. Our results define a cell autonomous role for mitochondrial proline catabolism and FAD homeostasis on sperm function and specify strategies to pharmacologically reverse these defects.

cell biology↗