Molecular Biology Commons^™

Investigating The Roles Of Platelet Bioenergetics In Hemostasis And Thrombosis, Kanakanagavalli Shravani Prakhya

Theses and Dissertations--Molecular and Cellular Biochemistry

Platelets use a series of energy-dependent processes to mediate hemostasis, yet it is unclear which metabolic fuels/pathways are critical for platelet function. Platelets are metabolically flexible, switching between glycolysis and oxidative phosphorylation (OxPhos) depending on oxygen tension and substrate availability. The deletion of GLUT1 and GLUT3 together revealed an essential role in platelet function and hemostasis. To study platelet bioenergetics, we used clot contraction. We created a sensitive and inexpensive method to simultaneously assess clot contraction kinetics to directly compare and define the effects of different treatments or genetic manipulations on platelet function.

Since the pharmacological inhibitors cannot be used …

The Role Of Dynamin Related Protein 1-Mediated Mitochondrial Dynamics In Colorectal Cancer, Sumati Raj Hasani

Theses and Dissertations--Molecular and Cellular Biochemistry

Cancer cells are known for their ability to adapt variable metabolic programs depending on the availability of specific nutrients. Consequently, metabolic reprogramming has been increasingly recognized as a major mechanism that fuels tumorigenesis and disease progression. Here, we have investigated the role of a pro-fission factor, Dynamin-Related Protein 1 (Drp1), in promoting metabolic adaptation in colon cancer.

Our studies have shown that fatty acid (FAs) uptake alters cellular metabolic pathways in colon cancer cells to favor fatty acid oxidation through the activation of Drp1. Uptake of FAs induces mitochondrial fragmentation by promoting ERK-dependent phosphorylation of Drp1 at the S616 site, …

The Development And Characterization Of Nanobodies Specific To Protein Tyrosine Phosphatase 4a3 (Ptp4a3/Prl-3) To Dissect And Target Its Role In Cancer., Caroline Smith

Theses and Dissertations--Molecular and Cellular Biochemistry

Protein Tyrosine Phosphatase 4A3 (PTP4A3 or PRL-3) is an oncogenic dual-specificity phosphatase that drives tumor metastasis, promotes cancer cell survival, and is correlated with poor patient prognosis in a variety of solid tumors and leukemias. The mechanisms that drive PRL-3’s oncogenic functions are not well understood, in part due to a lack of research tools available to study this protein. The development of such tools has proven difficult, as the PRL family is ~80% homologous and the PRL catalytic binding pocket is shallow and hydrophobic. Currently available small molecules do not exhibit binding specificity for PRL-3 over PRL family members, …

Novel Mechanistic Insight Into Ciliary Regulation: Old Pathways Yield New Mechanisms, Larissa L. Dougherty

Dartmouth College Ph.D Dissertations

Cilia are structures present on most eukaryotic cells which provide important signaling and motile components to cells from early development to fully differentiated and matured cells. Regulation of these structures is critical to proper functioning of the cell and is known to be tied to the cell cycle. Preparation for ciliary assembly following cell cycle exit and ciliary disassembly following cell cycle reentry requires components throughout the cell body and within the cilium to facilitate this process. Here I identify how the cell adapts to ensure modifications to cilia occur for assembly or disassembly using the model organism Chlamydomonas reinhardtii. …

The Effect Of Pomegranate Consumption On The Gut Microbiome, Brant Bandow

Browse all Theses and Dissertations

Pomegranate is known to have antioxidant and prebiotic qualities that have been shown to promote the growth of beneficial bacteria while reducing inflammation in the gut. Inflammation in the gut is an issue that results in many health problems including obesity and colon cancer. In this study, an experimental group received a daily pomegranate supplement for three weeks where a control group did not receive any supplement. After sequencing gDNA isolated from fecal samples from both before and after the trial period there was a significant difference between the two groups. The largest amount of variability is attributed to the …

A Novel Role Of Lipin1 In The Regulation Of Expression And Function Of Nnos, Ayat Azzam

Browse all Theses and Dissertations

Duchenne muscular dystrophy (DMD) is a severe and progressive muscular dystrophy that develops in the skeletal muscles because of mutations in the dystrophin gene. Dystrophin stabilizes sarcolemma and assembles neuronal nitric oxide synthase (nNOS) into the dystrophin-associated protein complex on the sarcolemma. The absence of dystrophin triggers the delocalization of nNOS and contributes to the misregulation of muscle development, blood flow, muscle fatigue, and inflammation. Lipin1 was reduced in the skeletal muscles of patients with DMD and the mdx mouse model of DMD. In this study, we explored the role of lipin1 in the regulation of nNOS expression and function. …

Brain Glycogen – Beyond Energy Storage In Glycogen Storage Diseases, Kia H. Markussen

Theses and Dissertations--Molecular and Cellular Biochemistry

Glycogen is a carbohydrate molecule that is traditionally viewed as a convenient and easily accessible energy storage form of glucose. However,emerging evidence supports the role of glycogen as more than a glucose storage form. During the last 20 years, glycogen has been shown to play pivotal roles in learning and memory, signaling events, viscosity, protein glycosylation, and be acritical hallmark in devastating diseases. Not only, does glycogen play a role as an energy substrate and critical metabolite during energy deprivation, glycogen is central for neurotransmitter homeostasis, tumor initiation, and ontributes to proper protein glycosylation in the brain. In this work, …

Metabolic Reprogramming Driven By Ezh2 Inhibition Depends On Cell–Matrix Interactions, Teresa W-M Fan, Jahid M. M. Islam, Richard M. Higashi, Penghui Lin, Christine F. Brainson, Andrew N. Lane

Markey Cancer Center Faculty Publications

EZH2 (Enhancer of Zeste Homolog 2), a subunit of Poly- comb Repressive Complex 2 (PRC2), catalyzes the trimethyla- tion of histone H3 at lysine 27 (H3K27me3), which represses expression of genes. It also has PRC2-independent functions, including transcriptional coactivation of oncogenes, and is frequently overexpressed in lung cancers. Clinically, EZH2 in- hibition can be achieved with the FDA-approved drug EPZ- 6438 (tazemetostat). To realize the full potential of EZH2 blockade, it is critical to understand how cell-cell/cell-matrix interactions present in 3D tissue and cell culture systems in- fluences this blockade in terms of growth-related metabolic functions. Here, we show that …

A Monoadduct Generating Ru(Ii) Complex Induces Ribosome Biogenesis Stress And Is A Molecular Mimic Of Phenanthriplatin, Richard Joseph Mitchell, Sarah M. Kriger, Alexander D. Fenton, Dmytro Havrylyuk, Ankit Pandeya, Yang Sun, Tami Smith, Jason E. Derouchey, David K. Heidary, Edith C. Glazer

Markey Cancer Center Faculty Publications

Ruthenium complexes are often investigated as potential replacements for platinum-based chemotherapeutics in hopes of identifying systems with improved tolerability in vivo and reduced susceptibility to cellular resistance mechanisms. Inspired by phenanthriplatin, a non-traditional platinum agent that contains only one labile ligand, monofunctional ruthenium polypyridyl agents have been developed, but until now, few demonstrated promising anticancer activity. Here we introduce a potent new scaffold, based on [Ru(tpy)(dip)Cl]Cl (tpy = 2,20:60,200-terpyridine and dip = 4,7-diphenyl-1,10-phenanthroline) in pursuit of effective Ru(II )-based monofunctional agents. Notably, the extension of the terpyridine at the 40 position with an aromatic ring resulted in a molecule that …

Bilirubin Levels Are Negatively Correlated With Adiposity In Obese Men And Women, And Its Catabolized Product, Urobilin, Is Positively Associated With Insulin Resistance, Zachary A. Kipp, Mei Xu, Evelyn A. Bates, Wang-Hsin Lee, Philip A. Kern, Terry D. Hinds Jr.

Markey Cancer Center Faculty Publications

Bilirubin levels in obese humans and rodents have been shown to be lower than in their lean counterparts. Some studies have proposed that the glucuronyl UGT1A1 enzyme that clears bilirubin from the blood increases in the liver with obesity. UGT1A1 clearance of bilirubin allows more conjugated bilirubin to enter the intestine, where it is catabolized into urobilin, which can be then absorbed via the hepatic portal vein. We hypothesized that when bilirubin levels are decreased, the urobilin increases in the plasma of obese humans, as compared to lean humans. To test this, we measured plasma levels of bilirubin and urobilin, …

Extracellular Vesicle Distribution And Localization In Skeletal Muscle At Rest And Following Disuse Atrophy, Ahmed Ismaeel, Douglas W. Van Pelt, Zachary Hettinger, Xu Fu, Christopher I. Richards, Timothy A. Butterfield, Jonathan J. Petrocelli, Ivan J. Vechetti Jr., Amy L. Confides, Micah J. Drummond, Esther E. Dupont-Versteegden

Markey Cancer Center Faculty Publications

Background Skeletal muscle (SkM) is a large, secretory organ that produces and releases myokines that can have autocrine, paracrine, and endocrine effects. Whether extracellular vesicles (EVs) also play a role in the SkM adaptive response and ability to communicate with other tissues is not well understood. The purpose of this study was to investigate EV biogenesis factors, marker expression, and localization across cell types in the skeletal muscle. We also aimed to investigate whether EV concentrations are altered by disuse atrophy.

Methods To identify the potential markers of SkM‑derived EVs, EVs were isolated from rat serum using density gradient ultracentrifugation, …

Polycomb Deficiency Drives A Foxp2-High Aggressive State Targetable By Epigenetic Inhibitors, Fan Chen, Aria Byrd, Jinpeng Liu, Robert M. Flight, Tanner Ducote, Kassandra J. Naughton, Xiulong Song, Abigail R Edgin, Alexsandr Lukyanchuk, Danielle T. Dixon, Christian M. Gosser, Dave-Preston Esoe, Rani Jayswal, Stuart H. Orkin, Hunter N. B. Moseley, Chi Wang, Christine Fillmore Brainson

Markey Cancer Center Faculty Publications

Inhibitors of the Polycomb Repressive Complex 2 (PRC2) histone methyltransferase EZH2 are approved for certain cancers, but realizing their wider utility relies upon understanding PRC2 biology in each cancer system. Using a genetic model to delete Ezh2 in KRAS-driven lung adenocarcinomas, we observed that Ezh2 haplo-insufficient tumors were less lethal and lower grade than Ezh2 fully-insufficient tumors, which were poorly differentiated and metastatic. Using three-dimensional cultures and in vivo experiments, we determined that EZH2-deficient tumors were vulnerable to H3K27 demethylase or BET inhibitors. PRC2 loss/inhibition led to de-repression of FOXP2, a transcription factor that promotes migration and stemness, and FOXP2 …

Suppressing Hepatic Ugt1a1 Increases Plasma Bilirubin, Lowers Plasma Urobilin, Reorganizes Kinase Signaling Pathways And Lipid Species And Improves Fatty Liver Disease, Evelyn A. Bates, Zachary A. Kipp, Genesee J. Martinez, Olufunto O. Badmus, Mangala M. Soundarapandian, Donald Foster, Mei Xu, Justin F. Creeden, Jennifer R. Greer, Andrew J. Morris, David E. Stec, Terry D. Hinds Jr.

Markey Cancer Center Faculty Publications

Several population studies have observed lower serum bilirubin levels in patients with non-alcoholic fatty liver disease (NAFLD). Yet, treatments to target this metabolic phenotype have not been explored. Therefore, we designed an N-Acetylgalactosamine (GalNAc) labeled RNAi to target the enzyme that clears bilirubin from the blood, the UGT1A1 glucuronyl enzyme (GNUR). In this study, male C57BL/6J mice were fed a high-fat diet (HFD, 60%) for 30 weeks to induce NAFLD and were treated subcutaneously with GNUR or sham (CTRL) once weekly for six weeks while continuing the HFD. The results show that GNUR treatments significantly raised plasma bilirubin levels and …

The Link Between Intracellular Calcium Signaling And Exosomal Pd-L1 In Cancer Progression And Immunotherapy, Rakibul Alam, Mizanur Rahman, Zhiguo Li

Markey Cancer Center Faculty Publications

Exosomes are small membrane vesicles containing microRNA, RNA, DNA fragments, and proteins that are transferred from donor cells to recipient cells. Tumor cells release exo- somes to reprogram the factors associated with the tumor microenvironment (TME) causing tu- mor metastasis and immune escape. Emerging evidence revealed that cancer cell-derived exosomes carry immune inhibitory molecule program death ligand 1 (PD-L1) that binds with re- ceptor program death protein 1 (PD-1) and promote tumor progression by escaping immune response. Currently, some FDA-approved monoclonal antibodies are clinically used for cancer treatment by blocking PD-1/PD-L1 interaction. Despite notable treatment outcomes, some pa- tients show …

Tissue And Sex-Dependent Regulation Of Innate Immunity And Rna Editing In Mice, Kelsey R. Kendrick

Graduate Theses/Dissertations

Inflammation occurs as a result of insult or infection within the body. Individual cells respond to inflammation by upregulating genes that help mediate the immune response, such as ADAR1. ADAR1 helps regulate the immune response but also catalyzes a process called RNA editing. RNA editing alters the sequence of select mRNAs to alter the encoded proteins. The result is altered function of the encoded protein, which is often beneficial for the cell. Our goal was to determine how inflammation affects the function of ADAR1. Since we know that the effects of inflammation vary between different organs and sexes, we examined …

Sex-Dependent Effects Of Induced Acute Inflammation On Glucose Homeostasis And Rna Editing Enzymes, Christian A. Rivas

Graduate Theses/Dissertations

The first line of defense against bodily insults, like pathogen invasion, is the innate immune system. Innate immunity sets in motion countless cascades that result in inflammation. Inflammation simultaneously affects multiple biological processes like metabolism and gene expression. Males and females react differently to inflammation. To understand both molecular and physiological sex differences in inflammation, we examined how inflammation affects gene expression and glucose metabolism. Adenosine deaminase acting on RNA (ADAR1) is upregulated by inflammation and catalyzes RNA editing, a process where nucleotides encoded by the genome are modified. ADAR1 also controls the innate immune reaction by decreasing activity of …

Molecular Investigation Of Minor Genomic Populations And Biological Exposures In Human Health, Brandon Ned Johnson

Dissertations and Theses

The study of genetics has contributed to countless discoveries related to human health and disease. However, the complexities of human biology reside not only in the genome but also in the contributions from environmental exposures, as measured via the classical twin design. To understand the influence of biological exposures, I implemented study designs to explore both the health associations and propagation of foreign genetic material. Microchimerism has been studied for association with several clinical conditions, and I further investigated if male microchimerism could elucidate the etiology of Mayer-Rokitansky-Küster-Hauser syndrome. Prevalence of male microchimerism in women with no history of pregnancy …

The Type Iv Pilus Secretin Bfpb: Structural Analysis And Binding Interactions, Janay I. Little

Theses and Dissertations

Enteropathogenic Escherichia coli (EPEC) causes severe diarrhea in young children. The type IV pilus (T4P) of EPEC, known as the bundle-forming pilus (BFP), plays an important role in EPEC pathogenesis. T4Ps are a family of surface appendages that are important for adhesion, colonization, biofilm formation, virulence, twitching motility and many other functions. One essential component of the BFP system is the secretin, BfpB. Secretins are a large family of integral outer membrane proteins found in T4Ps as well as type II and type III secretion systems, and filamentous phages. Details of the secretin structure have been limited to the overall …

Protacs – A Novel And Rapidly Developing Field Of Targeted Protein Degradation, Hannah R. Gatley

Theses and Dissertations

There is a continued need for new technology and strategies for tackling cancer and other diseases, and within the current century a novel therapeutic strategy has emerged in the realm of targeted protein degradation called Proteolysis-Targeting Chimeras (PROTACs). This technology specifically targets and degrades disease-causing proteins via the ubiquitin-proteasome system, and has seen an explosion of research and intrigue in both academia and industry over the past two decades. The diversity of PROTAC classes based on the E3 ligase recruiting ligand and the target protein allows for a universal molecular structure that can be customized for a specific target and …

Development Of A Chemical Biology Approach To Uncover The Influence Of Sequence Variations On Ces1 Activity In Live Cells, Samuel James Knebel

Masters Theses

Drug metabolism is the biochemical process of modifying drugs to detoxify and remove them through enzymatic transformations. These biotransformation’s occur primarily in the liver and are critical to understanding how pharmaceutical compounds are chemically altered inside the human body. Human carboxylesterases (CESs) catalyze the hydrolysis of esters, amides, thioesters, and carbamates. CES-mediated hydrolysis plays an important role in the metabolism of many drugs including the first FDA approved antiviral treatment for COVID-19, remdesivir (Veklury), the seizure control medication rufinamide (Banzel), and the flu antiviral drug oseltamivir (Tamiflu). CES activity is known to be influenced by a variety of factors including …