Biochemistry, Biophysics, and Structural Biology Commons^™

Glucose Metabolism Of Breast Cancer Sub-Clones That Preferentially Metastasize To The Lungs And Bone, Anna G. Skubiz

Honors Theses

Malignant breast cancers exhibit preferential metastasis to bone and lung (1). While changes in gene expression in lung-specific (LM) and bone-specific metastasis (BoM) lines derived from the MDA-MB-231 breast cancer line have been identified, few metabolic genes are differentially expressed; thus it is unknown if tissue-specific metabolic reprogramming occurs. Two hallmarks of cancer cells are an altered metabolic phenotype characterized by enhanced conversion of glucose to lactate in spite of adequate oxygen availability for complete mitochondrial oxidation of this substrate (referred to as aerobic glycolysis or the Warburg effect) and a greater dependence on glutamine. These changes in primary tumor …

The Impact Of Age/Rage Signaling On Oxidative Stress Under Diabetic Conditions In Cardiac Fibroblasts, Christopher Dorroh

Honors Theses

Diabetes is a major health concern in the United States, with 1.5 million new cases diagnosed each year. Patients who suffer from diabetes have an increased risk of developing heart failure, a form of cardiovascular disease. Heart failure has been shown to result from increased left ventricular stiffness, which in turn is caused by increased remodeling of the extracellular matrix (ECM). This increase in ECM remodeling is a result of AGE/RAGE signaling, which occurs at a heightened level in the cardiac fibroblast cells of diabetics. Studies have shown that diabetics have elevated levels of AGEs (Advanced Glycation End-Products), which bind …

Characterizing The Role Of Β-Amylase3 In Cold Stress Response And Recovery In Arabidopsis Thaliana, Isabelle G. Houston

Senior Honors Projects, 2020-current

Starch is a polymer of glucose that is used as an energy store in plants. Mobilization of starch has implications in abiotic stress survival and recovery. While the importance of carbon and energy allocation in plant survival has been explored, the specific roles of starch degrading enzymes in plant responses to stress are still unclear. β-Amylase3, or BAM3, is the principle starch degrading enzyme at night and is transcriptionally upregulated in response to cold stress in the plant Arabidopsis thaliana. Using single and quadruple knockout mutant plants, I aimed to clarify the role of BAM3 in the response to …

Mechanisms Of Statin Effects On Muscle And Neuronal Proteostasis, Daniel Yu

University Scholar Projects

Statins are widely prescribed and used chronically, but we know little about the effects on long-term protein homeostasis during stress and aging. Our aim was to quantify the effect of statins on stress-induced protein damage. We administered atorvastatin in a dose-response curve in Caenorhabditis elegans under naïve control conditions and in conditions of hypertonic and heat stress known to induce muscle damage measurable as countable puncta in a polyglutamine aggregation model of damage. We observed that there is significant polyglutamine aggregation variability among worms at baseline and thus further study requires within experiment baseline controls, per worm. Our results are …

The Autoimmune System: The Effect Of Physiological Stressors On Autoantibody Glycosylation And Fidelity Of Autoantibody Profiles, Rahil Kheirkhah

Graduate School of Biomedical Sciences Theses and Dissertations

The presence of thousands of autoantibodies (aABs) in the human sera is typical, and therefore it is possible to identify an aAB profile for each individual. In the first part of this thesis, we will show the cerebrospinal fluid also exhibits an extraordinarily complex immunoglobulin G aAB profile that is composed of thousands of aABs. We show that the pattern of expression of individual aABs in CSF closely mimics that in the blood, indicative of a blood-based origin for CSF aABs. In addition, using longitudinal serum samples obtained over a span of nine years, we show remarkable stability in aAB …

Functional Analysis Of A Critical Glycine (Glycine 12) In Beta-Type Connexins Of Human Skin, Rasheed Bailey

Biology Theses

At least five beta-type connexins are expressed in various layers of the skin (Cx26, Cx30, Cx30.3, Cx31, and Cx32) and all include a glycine residue at position 12. Glycine12 (G12) is located about halfway through the cytoplasmic amino terminus and has been the focus of several studies related to connexin diseases and gap junction channel structure. The importance of this residue is evident in the severity and diversity of diseases associated with amino acid substitutions at G12 including hereditary forms of skin disease, deafness and neuropathy. This study uses bioinformatic analysis in combination with mutational analysis and electrophysiology to better …

Utilizing Breathing Techniques To Maximize Training Performance, Peyton Cater

UNLV Theses, Dissertations, Professional Papers, and Capstones

Anaerobic exercise causes metabolic acidosis to occur in the muscle, which is unfavorable for sustaining high intensity activity, as fatigue starts to set in. In order to compensate for the onset of fatigue produced by an acidic environment, respiratory alkalosis, induced by hyperventilation, can be performed to mitigate these effects. In contrast, research has shown that slowing down the breath rate, such as a two second inhale and three second exhale, has led to an increase in performance outcomes. Purpose: To investigate power output and the physiological responses after implementation of different breathing techniques during the recovery periods of intermittent …

Alternative Polyadenylation Modulates Expression Of Pro-Fibrotic Proteins And Contributes To Lung Fibrosis, Junsuk Ko

Dissertations and Theses (Open Access)

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease which affects about 5 to 8 million individuals in the world. Despite the high prevalence, there is currently no cure for IPF, and the cause of this disease is still unclear. Our laboratory and collaborators have shown that nudix hydrolase 21 (NUDT21, which is also known as cleavage factor 25, CFIm25) is a key regulator of alternative polyadenylation (APA). NUDT21 depletion causes 3’UTR shortening via APA leading to enhanced mRNA stability and protein translation. This NUDT21 reduction promotes tumor growth in glioblastoma by enhancing expression of oncogenes. Cancer and IPF share …

Rapid Evolution Of Starvation Resistance In Drosophila: Physiological And Molecular Mechanisms, Austin Joseph Mckenna

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Gibbs lab has maintained starvation-selected Drosophila melanogaster for >130 generations. These starvation-selected flies evolved an obese phenotype with a suite of physiological differences compared to control-fed flies. Previous studies have shown that long-term starvation-selected Drosophila contain more lipids, have lower metabolic rates and develop more slowly than controls. This dissertation encompasses 1) Examining the molecular mechanisms contributing to starvation resistance, 2) Functional validation of the candidate plin1 allele, and 3) Rapid physiological and genomic evolution in starvation-selected Drosophila.

Starvation-selected Drosophila survive starvation conditions much longer than control-fed flies. This study took a simple approach to identify possible differences in …

Aminoacyl-Trna Synthetases, Miguel Angel Rubio Gomez, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The aminoacyl-tRNA synthetases are an essential and universally distributed family of enzymes that plays a critical role in protein synthesis, pairing tRNAs with their cognate amino acids for decoding mRNAs according to the genetic code. Synthetases help to ensure accurate translation of the genetic code by using both highly accurate cognate substrate recognition and stringent proofreading of noncognate products. While alterations in the quality control mechanisms of synthetases are generally detrimental to cellular viability, recent studies suggest that in some instances such changes facilitate adaption to stress conditions. Beyond their central role in translation, synthetases are also emerging as key …

Characterization Of A Split-Nluc Assay For Monitoring Changes In Alpha-Synuclein Solubility In Living Cells, Baolong Truong

Honors Program: Senior Projects (Public)

Alpha-synuclein is the primary constituent of Lewy Bodies, protein aggregates associated with Parkinson’s Disease, Dementia with Lewy Bodies, and Multiple Systems Dystrophy. Given the terminal nature of these synucleinopathies, the need for an assay that can report on alpha-synuclein aggregation levels in living systems is critical. Western blotting represents one potential approach to this problem; however, this technique can often be limited by selectivity of available antibodies and experimental reproducibility. Herein, we describe a novel luminescence-based assay capable of detecting alpha-synuclein solubility in bacterial cells. This platform can report on the influence of disease-relevant mutations and small molecules. Antibodies are …

Mixed-Lineage Kinase-3 (Mlk3) Plays A Negative Modulatory Role In Insulin Secretion From The Pancreatic Β-Cell, Tyler Russeth, Vijayalakshmi Thamilselvan, Anjaneyulu Kowluru

Medical Student Research Symposium

Glucose-stimulated insulin secretion (GSIS) from the pancreatic β-cell in response to elevated levels of glucose is controlled by a variety of signals including intracellular calcium and nucleotides such as cAMP, ATP and GTP. These cellular signals are responsible for activation of specific kinases that mediate phosphorylation of key exocytotic proteins that lead to GSIS. In the context of protein kinases, mixed-lineage kinases (MLKs) have been implicated in an assortment of cellular functions, including cell proliferation and apoptosis. However, very little is known on potential regulatory roles of MLKs in islet β-cell function, including GSIS. The goal of this study is …

Targeting Trna-Synthetase Interactions Towards Novel Therapeutic Discovery Against Eukaryotic Pathogens, Paul Kelly, Fatemeh Hadi-Nezhad, Dennis Y. Liu, Travis J. Lawrence, Roger G. Linington, Michael Ibba, David H. Ardell

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The development of chemotherapies against eukaryotic pathogens is especially challenging because of both the evolutionary conservation of drug targets between host and parasite, and the evolution of strain-dependent drug resistance. There is a strong need for new nontoxic drugs with broad-spectrum activity against trypanosome parasites such as Leishmania and Trypanosoma. A relatively untested approach is to target macromolecular interactions in parasites rather than small molecular interactions, under the hypothesis that the features specifying macromolecular interactions diverge more rapidly through coevolution. We computed tRNA Class-Informative Features in humans and independently in eight distinct clades of trypanosomes, identifying parasite-specific informative features, …

Isothermal Environmental Heat Energy Utilization By Transmembrane Electrostatically Localized Protons At The Liquid-Membrane Interface, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

This study employing the latest theory on transmembrane electrostatic proton localization has now, for the first time, consistently elucidated a decades-longstanding bioenergetic conundrum in alkalophilic bacteria and more importantly discovered an entirely new feature: isothermal environmental heat utilization by electrostatically localized protons at the liquid-membrane interface. It was surprisingly revealed that the protonic motive force (equivalent to Gibbs free energy) from the isothermal environmental heat energy utilization through the electrostatically localized protons is not constrained by the overall energetics of the redox-driven proton pump system because of the following: (a) the transmembrane electrostatically localized protons are not free to move …

Non-Invasive Method For Leptin Supplementation In Zebrafish (Danio Rerio), Regan Mcnamara

Williams Honors College, Honors Research Projects

I tested the hypothesis that recombinant leptin protein can be introduced to zebrafish in vivo through non-invasive soaking in a solution containing the protein. One way to study various molecules’ effects in vivo is through intraperitoneal or intracerebroventricular injections during the embryonic or larval stage, which is invasive, difficult to administer, and can have a high mortality rate. 48 hours post fertilization (hpf) zebrafish were soaked in a His-tagged recombinant leptin protein solution at 10 nM and 100 nM concentrations (produced by Genscript). After soaking, zebrafish larvae were washed extensively to remove all recombinant protein on their exterior before homogenization. …

Seasonal Variation In Mitochondrial Bioenergetics Of The Bluegill Sunfish, Lepomis Macrochirus, From A Shallow Midwest River, Derick Isaac Lamptey

Masters Theses

As average global temperature increase, the frequency and magnitude of extreme temperatures in shallow aquatic ecosystems are more ubiquitous. In order to understand how these changing thermal regimes affect aquatic ectotherms, it is essential to develop studies evaluating the response of ectotherms to seasonal fluctuating thermal regimes. Previous studies on fluctuating temperature regimes have reported an increased physiological stress leading to morphological, behavioral and biochemical adaptations. From the latter, the adaptive capacity and seasonal performance associated with optimal function of the oxidative phosphorylation system (OXPHOS) are key for species persistence. However, studies on this matter are scarce. This study explores …

Can The Carbon And Nitrogen Isotope Values Of Offspring Be Used As A Proxy For Their Mother's Diet? Using Foetal Physiology To Interpret Bulk Tissue And Amino Acid Δ15N Values, Nico Lübcker, John P. Whiteman, Seth D. Newsome, Robert P. Millar, P.J. Nico De Bruyn

Biological Sciences Faculty Publications

The measurement of bulk tissue nitrogen (δ¹⁵N) and carbon isotope values (δ¹³C) chronologically along biologically inert tissues sampled from offspring can provide a longitudinal record of their mothers' foraging habits. This study tested the important assumption that mother-offspring stable isotope values are positively and linearly correlated. In addition, any change in the mother-offspring bulk tissues and individual amino acids that occurred during gestation was investigated. Whiskers sampled from southern elephant seal pups (Mirounga leonina) and temporally overlapping whiskers from their mothers were analyzed. This included n = 1895 chronologically subsampled whisker segments for bulk …

Structural Features Contributing To Methylenedioxypyrovalerone (Mdpv) Analog Inhibition Of The Human Dopamine Transporter, Zachary R. Spires

Theses and Dissertations

Monoamine transporters (MATs) are transmembrane neurotransmitter sodium symporters consisting of the dopamine, norepinephrine, and serotonin transporters: DAT, NET, and SERT, respectively. Following an action potential and neurotransmitter vesicular release, MAT-mediated reuptake of these neurotransmitters in the presynaptic membrane contributes to the termination of monoaminergic neurotransmission. MATs are the targets of many drugs providing therapeutic benefits or taken recreationally. One of these drugs is methylenedioxypyrovalerone (MDPV), an abused synthetic cathinone that is a high potency uptake inhibitor of the human DAT (hDAT). In contrast, MDPV is a low potency uptake inhibitor of the Drosophila melanogaster dopamine transporter (dDAT). The reasons for …

Alanyl-Trna Synthetase Quality Control Prevents Global Dysregulation Of The Escherichia Coli Proteome, Paul Kelly, Nicholas Backes, Kyle Mohler, Christopher Buser, Arundhati Kavoor, Jesse Rinehart, Gregory Phillips, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Mechanisms have evolved to prevent errors in replication, transcription, and translation of genetic material, with translational errors occurring most frequently. Errors in protein synthesis can occur at two steps, during tRNA aminoacylation and ribosome decoding. Recent advances in protein mass spectrometry have indicated that previous reports of translational errors have potentially underestimated the frequency of these events, but also that the majority of translational errors occur during ribosomal decoding, suggesting that aminoacylation errors are evolutionarily less tolerated. Despite that interpretation, there is evidence that some aminoacylation errors may be regulated, and thus provide a benefit to the cell, while others …

The Fitness Landscape Of The African Salmonella Typhimurium St313 Strain D23580 Reveals Unique Properties Of The Pbt1 Plasmid, Rocío Canals, Roy R. Chaudhuri, Rebecca E. Steiner, Siân V. Owen, Natalia Quinones-Olvera, Melita A. Gordon, Michael Baym, Michael Ibba, Jay C. D. Hinton

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We have used a transposon insertion sequencing (TIS) approach to establish the fitness landscape of the African Salmonella enterica serovar Typhimurium ST313 strain D23580, to complement our previous comparative genomic and functional transcriptomic studies. We used a genome-wide transposon library with insertions every 10 nucleotides to identify genes required for survival and growth in vitro and during infection of murine macrophages. The analysis revealed genomic regions important for fitness under two in vitro growth conditions. Overall, 724 coding genes were required for optimal growth in LB medium, and 851 coding genes were required for growth in SPI-2-inducing minimal medium. These …

Inhibition Of Mitochondrial Permeability Transition By Deletion Of The Ant Family And Cypd, Jason Karch, Michael J. Bround, Hadi Khalil, Michelle A. Sargent, Nadina Latchman, Naohiro Terada, Pablo M. Peixoto, Jeffery D. Molkentin

Publications and Research

The mitochondrial permeability transition pore (MPTP) has resisted molecular identification. The original model of the MPTP that proposed the adenine nucleotide translocator (ANT) as the inner membrane pore-forming component was challenged when mitochondria from Ant1/2 double null mouse liver still had MPTP activity. Because mice express three Ant genes, we reinvestigated whether the ANTs comprise the MPTP. Liver mitochondria from Ant1, Ant2, and Ant4 deficient mice were highly refractory to Ca2+-induced MPTP formation, and when also given cyclosporine A (CsA), the MPTP was completely inhibited. Moreover, liver mitochondria from mice with quadruple deletion of Ant1, Ant2, Ant4, and Ppif (cyclophilin …

Translational Control Of Antibiotic Resistance, Anne Witzky, Rodney Tollerson Ii, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Many antibiotics available in the clinic today directly inhibit bacterial translation. Despite the past success of such drugs, their efficacy is diminishing with the spread of antibiotic resistance. Through the use of ribosomal modifications, ribosomal protection proteins, translation elongation factors and mistranslation, many pathogens are able to establish resistance to common therapeutics. However, current efforts in drug discovery are focused on overcoming these obstacles through the modification or discovery of new treatment options. Here, we provide an overview for common mechanisms of resistance to translation-targeting drugs and summarize several important breakthroughs in recent drug development.

Tracing Nutrient Sources To Lipid Production In Insects Using Stable Isotope (Δ13c, Δ2h) Tracers: Implications For Nutritional Physiology Of Migratory Species., Libesha Anparasan, Keith A. Hobson

Western Research Forum

Using stable isotope measurements of insect tissues to determine origin and migratory patterns is well established. However, isotopically determining nutritional origins of lipids, the primary fuel of migration, has not been as thoroughly researched. We explored isotopic links between diet and stored lipids in laboratory raised True armyworm moths (Mythimna unipuncta) using δ¹³C and δ²H measurements. Pupae were randomly separated into four groups (n=20) and fed isotopically distinct nectar, each consisting of a combination of high δ¹³C (C4 sugar), or low δ¹³C (C3 sugar) carbohydrate, with high δ²H (deuterium spiked), …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi S. Patel

University Scholar Projects

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi Patel

Honors Scholar Theses

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

A Dedicated Chaperone Mediates The Safe Transfer Of Mitoribosomal Proteins To Their Site Of Assembly, Gabrielle Ashley Hillman

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondrial ribosomes are functionally specialized for the synthesis of several essential inner membrane proteins of the respiratory chain. While remarkable progress has recently been made towards understanding the structure of mitoribosomes, the unique pathways and factors that facilitate their biogenesis remain largely unknown. This dissertation defines the physiological role of an evolutionarily conserved yeast protein called Mam33 in mitochondrial ribosome assembly. The biomedical relevance of this finding stems from the fact that mutations or changes in its expression of the human ortholog p32 result in mitochondrial dysfunction. In human patients, bi-allelic mutations cause severe multisystemic defects in mitochondrial energy metabolism, …

Extracellular Vesicles As Biological Shuttles For Targeted Therapies., Stefania Raimondo, Gianluca Giavaresi, Aurelio Lorico, Riccardo Alessandro

College of Osteopathic Medicine (TUN) Publications and Research

The development of effective nanosystems for drug delivery represents a key challenge for the improvement of most current anticancer therapies. Recent progress in the understanding of structure and function of extracellular vesicles (EVs)-specialized membrane-bound nanocarriers for intercellular communication-suggests that they might also serve as optimal delivery systems of therapeutics. In addition to carrying proteins, lipids, DNA and different forms of RNAs, EVs can be engineered to deliver specific bioactive molecules to target cells. Exploitation of their molecular composition and physical properties, together with improvement in bio-techniques to modify their content are critical issues to target them to specific cells/tissues/organs. Here, …

Alternative Nad(P)H Dehydrogenase And Alternative Oxidase: Proposed Physiological Roles In Animals, Allison Mcdonald, Dmytro V. Gospodaryov

Biology Faculty Publications

The electron transport systems in mitochondria of many organisms contain alternative respiratory enzymes distinct from those of the canonical respiratory system depicted in textbooks. Two of these enzymes, the alternative NADH dehydrogenase and the alternative oxidase, were of interest to a limited circle of researchers until they were envisioned as gene therapy tools for mitochondrial disease treatment. Recently, these enzymes were discovered in several animals. Here, we analyse the functioning of alternative NADH dehydrogenases and oxidases in different organisms. We propose that both enzymes ensure bioenergetic and metabolic flexibility during environmental transitions or other conditions which may compromise the operation …

Antisense Oligonucleotides Targeting Angiotensinogen: Insights From Animal Studies, Chia-Hua Wu, Ya Wang, Murong Ma, Adam E. Mullick, Rosanne M. Crooke, Mark J. Graham, Alan Daugherty, Hong S. Lu

Saha Cardiovascular Research Center Faculty Publications

Angiotensinogen (AGT) is the unique substrate of all angiotensin peptides. We review the recent preclinical research of AGT antisense oligonucleotides (ASOs), a rapidly evolving therapeutic approach. The scope of the research findings not only opens doors for potentially new therapeutics of hypertension and many other diseases, but also provides insights into understanding critical physiological and pathophysiological roles mediated by AGT.

Data Collection Curated With An Application Ontology Describes The Methods And Results Upon Performing An Ex-Vivo Voltage-Clamp Assay On Outer Hair Cells Of The Mammalian Cochlea, Brenda Farrell, Jason Bengtson

Research Data

This data collection describes the electrical properties of outer hair cells isolated from the mammalian cochlea of the domestic guinea pig. This data was obtained by performing whole-cell patch clamp voltage clamp assay on cells and monitoring the electrical admittance during a DC voltage ramp. The membrane capacitance was then calculated at each membrane potential from this admittance, and the voltage-independent and voltage-dependent membrane capacitance was determined upon further analysis. In some case the DC conductance was also measured by interrogation of the cell with voltage-step function which was calculated from the change in the mean steady-state current with respect …