Medicine and Health Sciences Commons^™

Mechanisms Of How Diet And Light Interact To Influence Drosophila Longevity Through The Eye, Charles H. Lau

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Previous studies in Drosophila melanogaster have established that overexposure to light damages photoreceptors and that photoreceptor degeneration contributes to shortened lifespans. However, the role of diet and circadian rhythms in the eye has not yet been elucidated. Many vital processes in the eye are regulated by circadian rhythms, and circadian misalignment has been proven as a driver of aging. In the eye, one of the most enriched circadian functions is phototransduction. Phototransduction plays a major role in the organism’s ability to detect light. Our lab has previously proven that Dietary Restrictions (DR) can play a role in amplifying circadian rhythms …

Advancing The Preclinical Development Of Secondary Metabolites From Cacospongia Mycofijiensis For The Treatment Of Cancer, Joseph Morris

Natural Sciences and Mathematics | Biological Sciences Master's Theses

The marine sponge Cacospongia mycofijiensis from the Indo-Pacific has proven to be a source of structurally diverse secondary metabolites that are biologically active against a variety of distinct targets. Current interest in the secondary metabolites of C. mycofijiensis largely stems from a) their potent and preferential cytotoxicity for cancer cell lines versus normal cells, making many of them promising leads as cancer therapeutics and b) the novel mechanisms of action responsible for their impressive cytotoxicity. However, limited compound availability has resulted in a paucity of studies aimed at advancing the preclinical development of these secondary metabolites from C. mycofijiensis for …

Determining The Role Of Methylglyoxal (Mgo) And The Trpa1 Channel In Inducing Astrocyte Senescence And Neurodegeneration, Natalie Hill

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Aging is the largest risk factor for the development of Alzheimer’s disease (AD) and related dementias. A recently proposed driver of age-related pathologies is cellular senescence, a phenotype that consists of cell-cycle arrest and an inflammatory response known as the senescence-associated secretory phenotype (SASP). Although there is a link between the accumulation of senescent cells and neurodegeneration, much remains unknown about how senescent cells arise in the brain. Astrocytes are the most abundant cell type in the brain that serve important roles like supporting neurons and proliferating in response to stress. Methylglyoxal (MGO) is a glycolytic byproduct that can react …

Modulating Matrix Metalloproteases And Inflammation In Huntington’S Disease, Alejandro Lopez Ramirez

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Huntington’s disease (HD) is a rare and incurable autosomal neurodegenerative disease affecting 1-10 in every 100,000 people in the world. There is no cure for HD and treatments available alleviate certain symptoms for short periods of time. Evidence suggests that neuropathology of HD begins with the proteolysis of the mutated Huntingtin (mHTT) protein. A variety of proteases, like the matrix metalloproteases, cleave mHTT creating proteinaceous fragments that are thought to be neurotoxic. As these fragments increase in the brain, the damage to neurons also increases, leading to chronic inflammation due to hyper reactive microglia and astrocytes attempting to minimize and …

Neuroprotection Against Alzheimer’S And Lifespan Extension Induced By Dietary Restriction Are Associated With Metabolomic Changes And Depend On Oxidative Resistance Protein 1 (Oxr1), George W. Brownridge Iii

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Dietary restriction (DR) has been demonstrated to be a robust means of extending the healthspan and lifespan, along with improving cognitive performance in various model organisms from yeast to primates, possibly by mediating neuroprotection. We utilized the Drosophila melanogaster model organism to better understand the molecular pathways that enable DR-induced benefits. By performing a genome-wide associated screening of the Drosophila Genetic Reference Panel (DGRP) that catalogues all natural genetic variants, we discovered that Oxidative resistance protein 1 (OXR1) showed the most significant difference in expression between DR and the inverse intervention of ad libitum (AL). Our research found that OXR1 …

Elucidating The Effects Of Glucose Toxicity On Tauopathy And Aging, Lukas Fluitt

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Diabetes patients are at higher risk of contracting an age-related neurodegenerative disease such as Alzheimer’s disease (AD). However, the mechanisms which link these diseases are poorly understood. We hypothesize that glucose and elevated levels of the glycolysis by product advanced glycation end-products (AGEs), may be involved. AGEs accumulate with age and are elevated in both diabetic and AD patients. Diabetes is a metabolic disorder for which consumption of sugar-rich diets is a major risk factor and is central to etiology in the vast majority of cases.

We show that transgenic C. elegans expressing wild type (WT) human tau fed a …

Determining The Link Between Advanced Glycation Endproducts (Ages), Feeding, And Metabolism, Lauren Wimer

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Reactive a-dicarbonyls (a-DC’s), such as methylglyoxal (MGO), are unavoidable metabolites generated during glycolysis that accumulate with age and have been linked with chronic age-related metabolic diseases such as Diabetes Mellitus. Diabetes Mellitus is generally characterized by peripheral neuropathy and sustained hyperglycemia. Chronic hyperglycemia leads to an increase in glycolysis and a downstream increase in reactive a-DC’s. The human body has a natural method of detoxifying these a-DC’s. Glycolytic cells have enzymes which can detoxify a-DC’s, but if overwhelmed, a-DC’s can accumulate and react non-enzymatically with proteins, lipids and DNA to yield a group of molecules called advanced glycation end-products (AGEs). …

Dietary Restriction Enhances Circadian Amplitude And Delays Visual Decline By A Clock-Driven Increase In Phototransduction, Geoff Meyerhof

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Aging is accompanied by a progressive loss of circadian rhythms. Lifespan-extending dietary paradigms such as dietary restriction (DR) enhance circadian amplitude and appear to extend lifespan in a clock-dependent fashion. However, the mechanisms by which DR amplifies circadian rhythms and why circadian rhythms decline with age have yet to be fully elucidated. Here we find that DR amplifies circadian amplitude by enhancing light sensitivity in the eye. We performed a circadian mRNA microarray in flies (Drosophila melanogaster) reared on DR or a high nutrient diet and found that DR increases the number of circadian transcripts and selectively amplifies the …

Investigating Neuroinflammation And Demyelination In The Nervous System Of Twitcher Mice By The Use Of Immunohistochemistry, Irene Wilson

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Neuroinflammation and demyelination are the hallmark lesions of the Twitcher mouse—the model of Krabbe Disease. By analyzing hemibrains and sciatic nerves via immunohistochemistry, we supported the microglial hypothesis that early activation of microglial cells, macrophages, and globoid cells in the nervous system of Twitcher mice results in specific cellular polarization states that may contribute to myelin loss. The influx of activated macrophages seen in both the central and peripheral nervous systems at days 21 and 17, respectively, accounted for this polarization. Using selected M1 and M2 markers, YKL-40, and GPNMB and CD206, respectively, we proved that microglial cells and macrophages …

Modulating P300 Acetylation Promotes The Rapid Degradation Of Erbb2 Mrna In Erbb2-Positive Breast Cancer Cells., Jacob Rose

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Histone deacetylase inhibitors (HDACi) are a novel class of drugs that target histone deacetylases, enzymes that by removing acetyl groups from the lysine resides of histones and many other non-histone proteins alter the cell’s chromatin structure and cellular functions, including regulation of protein translation and transcript stability. The mechanism of how these inhibitors destabilize some but not all transcripts remains incompletely understood. Our recent research has demonstrated that treatment of ERBB2-positive breast cancer cells with the HDAC1/2 selective HDACi, FK228 (Romidepsin) promotes rapid decay of various oncogenic mRNA transcripts including ERBB2 mRNA. Most recently we have demonstrated that histone acetyltransferase …