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Jonk, S.

Publications and source records attributed to Jonk, S..

2 recordsLinked to original sources

Supplementation via DAF-16 and pnk-1 driven pantothenate-coenzyme A flux improves disease related stress resistance in C. elegans

Metabolic pathways are increasingly recognized as tractable targets in aging and disease. Building on prior work demonstrating that supplementation with low-molecular weight metabolites (amino acids, vitamins, and their intermediates) can extend lifespan in Caenorhabditis elegans, we focused on pantothenate (vitamin B5), which is dysregulated in sarcopenic muscle and in several neurodegenerative and metabolic disorders. Pantothenate is the obligate precursor of coenzyme A through a short, highly conserved biosynthetic pathway in which loss-of-function mutations can cause neurodegeneration with brain iron accumulation. In C. elegans, the longevity curtailing transcription factor DAF-16/FOXO has a conserved binding element in the promoter region of pnk-1, encoding the first enzyme (PNK-1) in the coenzyme A pathway, and pnk-1 is markedly upregulated in long-lived daf-2 (insulin/-like receptor) mutants, implicating coenzyme A metabolism in longevity. Here, we demonstrate that CoA levels naturally increase during early life and decrease towards older age in C. elegans. Dietary pantothenate supplementation increases coenzyme A levels with minimal effects on lifespan but systemic effects on lipid metabolism, mitochondrial dynamics, and muscle structure under basal conditions. Under DAF-16-associated stress conditions, including heat and oxidative stress, pnk-1 expression is upregulated and pantothenate supplementation robustly extends lifespan and improves mobility. Finally, we demonstrate dysregulation of daf-16 and pnk-1 expression in amyotrophic lateral sclerosis (ALS) models, in which pantothenate supplementation confers both lifespan extension and cholinergic neuroprotection.

neuroscience↗

Metabolic analysis of sarcopenic muscle identifies positive modulators of longevity and health span in C. elegans

Sarcopenia is the age-related degeneration of skeletal muscle, resulting in loss of skeletal muscle tone, mass, and quality. Skeletal muscle is a source of systemic metabolites and macromolecules important for neuronal health, function and healthy neuronal aging. Age-related loss of skeletal muscle might result in decreased metabolite and macromolecule availability, resulting in reduced neuronal function or increased susceptibility to unhealthy aging and neurodegenerative diseases. We aimed to identify muscle metabolite candidates that regulate healthy aging. C57BL/6J mice were aged to young adult (4 months) and old age (25 months) and skeletal muscle was collected. Age related muscle loss was confirmed by reduced muscle mass, muscle fiber degeneration, reduced myosin intensity, in addition to a metabolic shift and increased DNA damage in skeletal muscle. Using a low molecular weight enriched metabolomics protocol, we assessed the metabolic profile of skeletal muscle from young adult and old mice and identified 20 metabolites that were significantly changed in aged muscle. These candidate metabolites were tested in C. elegans assays of lifespan, health span, muscle-, and mitochondrial morphology under normal and stressed conditions. We identified four candidate metabolites (beta-alanine, 4-guanidinobutanoic acid, 4-hydroxyproline, pantothenic acid) that when supplemented in C. elegans provided robust gero- and mitochondrial protection. These candidates also affected life-, and health span in C. elegans models of amyotrophic lateral sclerosis and Duchenne muscular dystrophy. Our findings support that aging muscle can be used to identify novel metabolite modulators of lifespan and health and may show promise for future treatments of neurodegenerative and neuromuscular disorders.

cell biology↗