The biphasic and age-dependent impact of Klotho on hallmarks of aging and skeletal muscle function
Abstract
Aging is accompanied by disrupted information flow, resulting from accumulation of molecular mistakes. These mistakes ultimately give rise to debilitating disorders including skeletal muscle wasting, or sarcopenia. To derive a global metric of growing 'disorderliness' of aging muscle, we employed a statistical physics approach to estimate the state parameter, entropy, as a function of genes associated with hallmarks of aging. Escalating network entropy reached an inflection point at old age, while structural and functional alterations progressed into oldest-old age. To probe the potential for restoration of molecular 'order' and reversal of the sarcopenic phenotype, we systemically overexpressed the longevity protein, Klotho, via AAV. Klotho overexpression modulated genes representing all hallmarks of aging in old and oldest-old mice, but pathway enrichment revealed directions of changes were, for many genes, age-dependent. Functional improvements were also age-dependent. Klotho improved strength in old mice, but failed to induce benefits beyond the entropic tipping point.
Data availability
Sequencing data has been deposited in GEO accession: GSE156343.
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The biphasic and age-dependent impact of Klotho on hallmarks of aging and skeletal muscle functionNCBI Gene Expression Omnibus, GSE156343.
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Tabula Muris SenisNCBI Gene Expression Omnibus, GSE132040.
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Skeletal Muscle Transcriptome in Healthy AgingNCBI Gene Expression Omnibus, GSE164471.
Article and author information
Author details
Funding
National Institute on Aging (R01AG052978)
- Fabrisia Ambrosio
National Institute on Aging (R01AG061005)
- Fabrisia Ambrosio
Boehringer Ingelheim
- Fabrisia Ambrosio
J.H., S.K. and M.F. are employees of Boehringer Ingelheim Pharmaceutical Company. They contributed to development, testing and validation of the AAV-Klotho vector, as well as the overall study design.
Ethics
Animal experimentation: All animal experiments were performed with prior approval from the Institutional Animal Care and Use Committee of the University of Pittsburgh. These experiments were conducted in accordance with protocol 17080802 (University of Pittsburgh ARO: IS00017744). All surgeries and invasive procedures were performed under isoflurane anesthesia, with painkillers administered afterwards. Every effort was made to minimize suffering.
Copyright
© 2021, Clemens et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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