Novel elasticity measurements reveal C. elegans cuticle stiffens with age and in a long-lived mutant.

TitleNovel elasticity measurements reveal C. elegans cuticle stiffens with age and in a long-lived mutant.
Publication TypeJournal Article
Year of Publication2022
AuthorsRahimi, M, Sohrabi, S, Murphy, CT
JournalBiophys J
Volume121
Issue4
Pagination515-524
Date Published2022 02 15
ISSN1542-0086
KeywordsAnimals, Caenorhabditis elegans, Caenorhabditis elegans Proteins, Collagen, Elasticity, Longevity, Mammals
Abstract

<p>Changes in biomechanical properties have profound impacts on human health. C. elegans might serve as a model for studying the molecular genetics of mammalian tissue decline. Previously, we found that collagens are required for insulin signaling mutants' long lifespan and that overexpression of specific collagens extends wild-type lifespan. However, whether these effects on lifespan are due to mechanical changes during aging has not yet been established. Here, we have developed two novel methods to study the cuticle: we measure mechanical properties of live animals using osmotic shock, and we directly perform the tensile test on isolated cuticles using microfluidic technology. Using these tools, we find that the cuticle, not the muscle, is responsible for changes in the "stretchiness" of C. elegans, and that cuticle stiffness is highly nonlinear and anisotropic. We also found that collagen mutations alter the integrity of the cuticle by significantly changing the elasticity. In addition, aging stiffens the cuticle under mechanical loads beyond the cuticle's healthy stretched state. Measurements of elasticity showed that long-lived daf-2 mutants were considerably better at preventing progressive mechanical changes with age. These tests of C. elegans biophysical properties suggest that the cuticle is responsible for their resilience.</p>

DOI10.1016/j.bpj.2022.01.013
Alternate JournalBiophys J
PubMed ID35065051
PubMed Central IDPMC8874029
Grant ListP40 OD010440 / OD / NIH HHS / United States