ORCID

https://orcid.org/0000-0002-8483-9852

Date of Award

Fall 2024

Language

English

Embargo Period

10-9-2024

Document Type

Master's Thesis

Degree Name

Master of Science (MS)

College/School/Department

Department of Biological Sciences

Program

Biology

First Advisor

Thomas Begley

Committee Members

Gabriele Fuchs, J. Andres Melendez

Keywords

senescence, aging, epitranscriptomics, RNA, senolytics, senomorphics

Abstract

In senescence that occurs with aging, cells stop dividing and initiate a pro-inflammatory program called the senescence associated secretory phenotype (SASP). SASP can lead to cell damage and has been linked to age-related conditions such as cancer, diabetes, osteoporosis, cardiovascular disease, Alzheimer’s disease, and osteoarthritis. The epitranscriptome regulates translation through post-transcriptional RNA modifications and can control when and how much of protein synthesis occurs. Several tRNA modifications that include 5-methoxycarbonylmethyl (mcm5U), 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U), and mcm5Um (5-methoxycarbonylmethyl-2′-O-methyluridine) are linked to the translation of enzymes involved in the detoxification of reactive oxygen species (ROS), and defects in these tRNA modifications have been shown to promote senescence. We examined the reprogramming of tRNA modifications in response to pharmaceuticals that limit senescence or SASP in mouse embryonic fibroblast (MEF) cells and human lung fibroblast (IMR-90) cells. These cells were treated with senolytics (Navitoclax and Quercetin) and senomorphs (Metformin and Taurine). Small RNA was purified to analyze tRNA modifications by LC-MS/MS. We have demonstrated that senolytics and senomorphs can re-program tRNA modifications in wild type mouse embryonic fibroblasts, specifically 5-methylthio-2-methyluracil (s2mo5U), 7-methylguanosine (m7G), 5-methylcytosine-2-thiouridine (mcm5s2U), 2’-O-methylguanosine (Gm), N1-Methyladenosine (m1A), and 5-methoxyuridine (mo5U). We have also demonstrated that senolytics and senomorphs can re-program tRNA modifications in senescent human lung fibroblasts, specifically 7-methylguanosine (m7G), 1-methylguanosine (m1G), N2,N2-dimethylguanosine (m22G), 2-methylguanosine (m2G), 5-methylcytosine (m5C), N6-methyladenosine (m6Am), 5-methoxycarbonylmethyl (mcm5U), 2-thiocytidine (s2C), and pseudouridine (Ψ), with our studies being some of the first to explore this hypothesis. Our studies highlight the potential of using senolytic and senomorphic therapeutic agents to treat tRNA-related diseases.

License

This work is licensed under the University at Albany Standard Author Agreement.

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