Age-related declines in ?-Klotho drive progenitor cell mitochondrial dysfunction and impaired muscle regeneration.

ABSTRACT: While young muscle is capable of restoring the original architecture of damaged myofibers, aged muscle displays a markedly reduced regeneration. We show that expression of the "anti-aging" protein, ?-Klotho, is up-regulated within young injured muscle as a result of transient Klotho promoter demethylation. However, epigenetic control of the Klotho promoter is lost with aging. Genetic inhibition of ?-Klotho in vivo disrupted muscle progenitor cell (MPC) lineage progression and impaired myofiber regeneration, revealing a critical role for ?-Klotho in the regenerative cascade. Genetic silencing of Klotho in young MPCs drove mitochondrial DNA (mtDNA) damage and decreased cellular bioenergetics. Conversely, supplementation with ?-Klotho restored mtDNA integrity and bioenergetics of aged MPCs to youthful levels in vitro and enhanced functional regeneration of aged muscle in vivo in a temporally-dependent manner. These studies identify a role for ?-Klotho in the regulation of MPC mitochondrial function and implicate ?-Klotho declines as a driver of impaired muscle regeneration with age.

SUBMITTER: Sahu A 

PROVIDER: S-EPMC6242898 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature