title: Sarcopenia in the Caenorhabditis elegans pharynx correlates with muscle contraction rate over lifespan.
abstract: In muscles, sarcopenia, the loss of muscle mass, is the major cause of aging-related functional decline and frailty. Several factors are correlated with sarcopenia during aging, including contraction-related cellular injury, oxidative stress, endocrine changes and reduced regenerative potential. However the involvement of these factors has not been experimentally investigated. Here, we report that contraction-related injury may significantly promote the progression of sarcopenia in the pharynx of the nematode, Caenorhabditis elegans, a model of aging in non-regenerative tissues. Both functional and structural declines in the pharynx during aging were significantly delayed in mutants with reduced muscle contraction rates. We also examined the role of bacteria in pharynx muscle decline during aging, as previous studies reported that antimicrobial treatments could extend C. elegans lifespan. Although microbial infection may have enhanced functional decline in the pharynx during aging, it was not the sole cause of decreased pumping rates in old animals. This study identifies contraction-related injury as a factor affecting the initiation and progression of sarcopenia during aging. Further, characterization of the specific types of damage induced by muscle contraction will be helpful for understanding the underlying causes of sarcopenia.
authors.affiliation: Laboratory of Neurosciences, National Institute on Aging/Intramural Research Program (NIA/IRP), Gerontology Research Center, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA.
authors.forename: David K
authors.initials: DK
authors.lastname: Chow
authors.forename: Charles F
authors.initials: CF
authors.lastname: Glenn
authors.forename: Josiah L
authors.initials: JL
authors.lastname: Johnston
authors.forename: Ilya G
authors.initials: IG
authors.lastname: Goldberg
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Wolkow
mesh_terms: D000375:Aging / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001419:Bacteria / Q000254:growth & development; D001424:Bacterial Infections / Q000150:complications; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism; D004195:Disease Models, Animal; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000382:microbiology / Q000503:physiopathology; D009133:Muscular Atrophy / Q000209:etiology / Q000503:physiopathology*; D009154:Mutation; D018384:Oxidative Stress / Q000502:physiology; D010614:Pharynx / Q000187:drug effects / Q000382:microbiology / Q000503:physiopathology*; D012701:Serotonin / Q000494:pharmacology; D018490:Serotonin Agents / Q000494:pharmacology
chemical_list: D029742:Caenorhabditis elegans Proteins; D018490:Serotonin Agents; D012701:Serotonin