Publication Date

2019

Document Type

Honors Project

Degree Name

Bachelor of Arts

Department

Biochemistry

Advisors

Stylianos P. Scordilis

Keywords

Skeletal muscle, Sarcopenia, Proteomics, Oxidative stress, Omega-3 diet, Aging, Metabolism, Inflammation, Autophagy

Abstract

Sarcopenia is the process of skeletal muscle aging, which has an extremely complex molecular component. As one ages, the proteome of the skeletal muscle changes to result in the phenotype of weakness. Elucidating these changes in protein abundances that occur with aging, can help to evaluate potential interventions against aging. Interventions that can help preserve muscle function and resiliency are important to study, particularly in a society with an ever growing aged population. In this study, we seek to elucidate proteomic changes that occur in the medial gastrocnemius muscle as a result of aging with the added variable of omega-3 enriched diet (O3). To study these two variables, four conditions of rat medial gastrocnemius were studied; young control diet (YCTL), aged control diet (ACTL), young omega-3 (YO3), and aged omega-3 (AO3). Proteomic differences were established by isobaric TMT-tags and quantitative LC-MS. O3 diet resulted in an overall increase of protein abundance that seems to have been caused by an overall increase in oxidative stress protection proteins. The increase in oxidative stress protection may lead to a decrease in oxidative damage and an increase in whole protein abundance. The diet caused a greater effect on protein increases in the young rats than the aged rats, indicating that the pathway through which O3 leads to increase in oxidative stress protection proteins may be age sensitive.

O3 diet preferentially increased the expression of myosin and myosin related proteins over other types of proteins. Aside from contractile elements increasing, there was also an increase in mitophagy related proteins, electron transport chain proteins, and biogenesis proteins with O3 that was decreased with age.

The trend of proteins decreasing with age but increasing with diet suggests that O3 is a possible therapeutic agent against age-related decreases in protein abundances. Mechanistically this is probably due to increases in biogenesis and autophagy related proteins that are lost with age in skeletal muscle.

Rights

©2019 Marguerite Aurora Pacheco. Access limited to the Smith College community and other researchers while on campus. Smith College community members also may access from off-campus using a Smith College log-in. Other off-campus researchers may request a copy through Interlibrary Loan for personal use.

Language

English

Comments

80 pages : color illustrations. Includes bibliographical references (pages 77-79)

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