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Lozar_dissertation document.pdf (2.43 MB)
ETD Abstract Container
Abstract Header
Does Proteasome Activity Impact Skeletal Muscle Hypertrophy?
Author Info
Lozar, Olivia Mae
Permalink:
http://rave.ohiolink.edu/etdc/view?acc_num=toledo1576264202406223
Abstract Details
Year and Degree
2019, Doctor of Philosophy, University of Toledo, Exercise Science.
Abstract
The Ubiquitin-Proteasome System (UPS) is the primary machinery responsible for protein degradation within skeletal muscle. There is evidence to suggest that the proteasome is activated during skeletal muscle hypertrophy, indicating a causative relationship between hypertrophy and protein degradation. However, there is no evidence to suggest the direct role that the proteasome plays on skeletal muscle growth. Therefore, the purpose of this study was to pharmacologically inhibit the proteasome in order to directly measure its contribution to skeletal muscle hypertrophy. Given the relationship between proteasome activity and hypertrophy, we hypothesized that upon inhibition of the proteasome there would be a reduction in skeletal muscle hypertrophy. To determine the role of the proteasome on skeletal muscle hypertrophy, a 10-day bilateral synergist ablation or a sham surgery was utilized. Twice daily injections of 7.5mg/kg MG-132 or vehicle (20g/L carboxymethylcellulose + 2.5g/L Tween-20 + 20% DMSO) were administered during this time. To determine the extent of muscle hypertrophy, plantaris muscles were weighed directly after excision, and whole muscle and individual fiber CSA were analyzed. Release of fluorescent signal was monitored over a two-hour time point. Additionally, total ubiquitination was measured through western blotting. Our findings show that i) proteasome activity is increased following synergist ablation ii) inhibition of the proteasome resulted in a reduced response in hypertrophy following synergist ablation iii) total ubiquitination increased following synergist ablation but was attenuated following MG-132 administration. The major finding of this study was that proteasome activity increased following chronic overload, and when the proteasome was inhibited, hypertrophy did not occur to the same extent. Therefore, our findings suggest that an increase in proteasome activity is necessary to support exercise-induced skeletal muscle hypertrophy.
Committee
Thomas McLoughlin (Advisor)
Barry Scheuermann (Committee Member)
Abraham Lee (Committee Member)
Wendi Goodlin-Fahncke (Committee Member)
Pages
75 p.
Subject Headings
Biology
;
Kinesiology
Keywords
Skeletal muscle hypertrophy
;
proteasome
;
ubiquitin-proteasome
;
protein degradation
;
hypertrophy
;
MG132
;
MG-132
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Citations
Lozar, O. M. (2019).
Does Proteasome Activity Impact Skeletal Muscle Hypertrophy?
[Doctoral dissertation, University of Toledo]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1576264202406223
APA Style (7th edition)
Lozar, Olivia.
Does Proteasome Activity Impact Skeletal Muscle Hypertrophy?
2019. University of Toledo, Doctoral dissertation.
OhioLINK Electronic Theses and Dissertations Center
, http://rave.ohiolink.edu/etdc/view?acc_num=toledo1576264202406223.
MLA Style (8th edition)
Lozar, Olivia. "Does Proteasome Activity Impact Skeletal Muscle Hypertrophy?" Doctoral dissertation, University of Toledo, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1576264202406223
Chicago Manual of Style (17th edition)
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Document number:
toledo1576264202406223
Download Count:
223
Copyright Info
© 2019, some rights reserved.
Does Proteasome Activity Impact Skeletal Muscle Hypertrophy? by Olivia Mae Lozar is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by University of Toledo and OhioLINK.