Degree

Doctor of Philosophy (PhD)

Department

Kinesiology

Document Type

Dissertation

Abstract

Spaceflight has been shown to induce severe physiological adaptations that cause chronic health conditions. One of these major adaptations is spaceflight-induced muscular atrophy which is characterized by the loss of muscle mass. Apart from losses in force production and work capacity, there is evidence that muscular metabolism is adversely affected.

Mitochondria have been shown to have a central role in spaceflight induced adaptations and physiological changes. As these organelles are at the center of metabolic function, changes in their function have severe consequences on cellular health. Prior studies have shown that spaceflight can cause reduced bioenergetic capacity. Also shown is a shift in fuel utilization that is associated with altered reliance on different metabolic pathways.

Changes in metabolic function of the mitochondria are closely tied to changes in mitochondrial morphology. In health cells, the mitochondrial network is maintained by several processes at the genetic, protein, and post-translational level. These processes combat mitochondrial dysfunction through the scavenging of oxidative species, the repair and removal of damaged mitochondrial proteins, and the synthesis and integration of new proteins into the mitochondrial network. There is evidence in ground-based models that muscular disuse and ionizing radiation both induce mitochondrial dysfunction through inhibition of these processes.

The purpose of this dissertation is to examine the effects of spaceflight on mitochondrial quality control pathways and associated changes in mitochondrial function. To do this, we utilized spaceflight and spaceflight analog models to examine changes in muscle proteins and gene expression associated with mitochondrial quality control and bioenergetics. Our findings indicated that several stressors associated with the environment of space contribute to the induction of mitochondrial dysfunction, causing muscular dysfunction and atrophy.

Date

4-3-2025

Committee Chair

Heather Allaway

Available for download on Thursday, April 01, 2032

Included in

Kinesiology Commons

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