Molecular Biology Commons^™

Self-Assembling Rna Nanostructures Are Highly Sensitive To Environmental Conditions, Jordan Aposhian, Surya Pratap S. Deopa, Scott Horowitz, Joseph D. Yesselman

Chemistry and Biochemistry: Faculty Scholarship

Recent developments in RNA nanotechnology have led to an increase in the design of specific, higher-order RNA structures, which will ultimately be used in drug delivery and immunomodulation applications. As researchers create RNA nanostructures with the intention of making them a standard tool in molecular biologists' toolkits, further investigation is required into the robustness of RNA designs. Primarily, in what different molecular contexts are the designed and intended nanostructures stable? In this work, we show that RNA nanostructure self-assembly is highly sensitive to environmental conditions by using second-order right-angle light scattering. While a test RNA hexagonal grid nanostructure forms correctly …

Development Of Self-Assembled Polymeric Polyplexes For Microrna Delivery: Toward Treatment Of Alcohol-Associated Liver Disease, Marjina Akter Kalpana

Theses & Dissertations

Self-assembled polymeric polyplexes have the potential to serve as an RNA interference (RNAi) delivery platform for the combined inhibition of CXCR4 and miR-155 in the treatment of alcohol-associated liver disease (AALD). A central challenge in RNA delivery is balancing the extracellular stability of polyplexes, cellular uptake, and intracellular release of RNA cargo. We developed polymeric polyplexes using the CXCR4-antagonist polymer PAMD, designed to target CXCR4 on activated hepatic stellate cells (HSCs) and deliver therapeutic miRNA to activated Kupffer cells (KCs) in fibrotic liver. We improved the polyplexes by cholesterol modification of PAMD and by PEGylation of PAMD-Ch. The cholesterol modification …

Evaluating Bmx-001 As A Selective Radioprotector For Healthy Tissue In Pelvic Cancers, Molly Myers

Theses & Dissertations

Pelvic cancers, including rectal, anal, and prostate cancer, are relatively survivable cancers with high five-year survival rates, partially due to the addition of radiation to treatment regimens. Radiation confers excellent tumor control, but also causes damage to surrounding tissue, resulting in both short-term and long-term side effects. In a patient population that is surviving longer after treatment, limiting the impact of side effects is instrumental to improving patient quality of life. Radiation-induced ROS is instrumental in causing these side effects and provides a unique opportunity to protect healthy tissue from damage while sensitizing cancer tissue to treatment, as cancer cells …

Investigating The Role And Mechanism Of Faecalibacterium Prausnitzii In Fatty Acid Metabolism And Obesity Using The Drosophila Melanogaster Model, Jackson Head, Whitley Whitehead

Student Scholar Symposium

The obesity epidemic has increased to enormous numbers with 890 million adults being classified as obese (BMI≥30). Obesity is of extreme concern as it is a comorbidity to coronary heart disease, type-2 diabetes, and cancer. Although obesity has classically been attributed to genetics and lifestyle, there is a growing interest in other factors, including the gut microbiome. Germ-free mice are resistant to weight gain even when placed on a high-calorie diet, establishing that metabolites produced by gut microbiota can dramatically inhibit metabolism. Here, we use Faecalibacterium prausnitzii, which has been previously shown to be reduced in obese individuals; however, …

Indole Improves Outcomes Of Cronobacter Sakazakii Infection In C. Elegans Through Ahr-1, Cayden Durrough

Student Scholar Symposium

Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease primarily affecting premature infants. Toll-like receptor 4 (TLR4)-mediated epithelial damage allows microbial translocation, triggering inflammation that can lead to sepsis and death. The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor, and AhR ligands have been shown to prevent NEC in a mouse model. Indole, an AhR ligand, has been reported to extend the healthspan of C. elegans, and we have shown previously it mitigates poor outcomes in wild-type worms infected with Cronobacter sakazakii (Cs), a bacterial pathogen linked to NEC. We hypothesized that C. elegans must express ahr-1, the ortholog …

Levels Of Beta Catenin With Treatment Of Hd5 In Iec-6 Rat Cells, Audrey Birdwell, Josiah Stafford, Obaid Ashari, Emily Powell, Maryam Gerges, Maryam Mina

Student Scholar Symposium

Human Defensin 5 (HD5) is an antimicrobial peptide present in the small intestine that plays a role in gut homeostasis. We have been investigating the role of HD5 in colon cells, but research shows that HD5 levels in the small and large intestine vary significantly in Crohn's. Previous data from our lab suggests that HD5 leads to a decrease in wound healing and an increase in apoptosis in colon cells, we want to see if the same is true in the small intestine. So, we are investigating the effect of HD5 on expression of β-catenin, a key protein in the …

Understanding The Role Of Hd5 In Colonic Epithelial Cell Death, Maryam M. Gerges, Amanda D. Williams

Student Scholar Symposium

Inflammatory bowel disease (IBD) is an autoimmune disorder where the immune system attacks healthy tissue. IBD can occur in both adults and children, describing Ulcerative Colitis (UC) and Crohn’s Colitis (CC). Our lab studies human alpha defensin 5 (HD5), an antimicrobial peptide that normally maintains small intestinal sterility. However, in CC patients, HD5 is overexpressed in the colon. Preliminary data suggests that HD5 increases colonic cell death. This project aims to determine if HD5 induces apoptosis and its mechanisms. To this end, we will test if the suppression of caspase enzymes with a pan-caspase inhibitor reduces cell death triggered by …

Functionality Of The Ryanodine Receptor Type 1 (Ryr1) In The Development Of Malignant Hyperthermia (Mh), Cesar Medina, Joshua Owens

Student Scholar Symposium

Malignant Hyperthermia (MH) is a rare but potentially lethal pharmacogenetic disorder, affecting roughly 1 in 30,000 children and 1 in 100,000 adults undergoing surgery. MH can be triggered by agents used for general anesthesia. These may include volatile anesthetics such as sevoflurane, isoflurane, desflurane, halothane or depolarizing neuromuscular blockers such as succinylcholine. Upon administration of a trigger, an MH susceptible (MHS) patient can develop a hypermetabolic state during the intraoperative or postoperative periods. If not treated quickly, an MH episode could result in organ dysfunction or death. The primary mechanisms involved in the development of an MH crisis include the …

Elucidating The Effects Of Hd5 On Actc1 Expression In Crohn's Disease, Carolyn Tran, Sohir Abdelnour, Joyce Lawson, Ellis Puscas

Student Scholar Symposium

Approximately 1.6 million Americans currently have Crohn’s Disease (CD), a condition that affects the gastrointestinal (GI) tract, particularly the small intestine, leading to chronic inflammation, abdominal pain, severe diarrhea, and fatigue. Although treatments exist, misdiagnosis remains a challenge due to symptom overlap with other inflammatory bowel diseases (IBD). Previous studies have shown an increase in Human Alpha Defensin (HD5) in Crohn’s Colitis, resulting in slower wound healing closure, increased apoptosis, and potential effects regarding alpha-actin expression. However, its effects in the small intestine remain unclear. Alpha-actin is a cytoskeletal protein that maintains cellular structure through cell migration, tissue remodeling, and …

Structural Basis Of A Class Ii Ribonucleotide Reductase Found If Mycobacterium Tuberculosis, Leah Jacob

Student Scholar Symposium

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a leading global health challenge, particularly due to its ability to enter a dormant, drug-tolerant state that enables long-term persistence within the host. Just before dormancy, Mtb replicates its entire genome creating DNA precursors for when the infection reactivates. Ribonucleotide reductases (RNRs) play a critical role in bacterial survival by catalyzing the conversion of ribonucleotides into deoxyribonucleotides, a necessary step for DNA replication and repair. The class II RNR, NrdZ, has been implicated in facilitating Mtb persistence under hypoxic stress conditions, yet its structural and mechanistic function remains largely uncharacterized. …

Structural Basis Of Panx1 Permeation And Positive Modulation By Mefloquine, Yangyang Li, Zheng Ruan, Junuk Lee, Ian Orozco, Edward Zhou, Juan Du, Wei Lü

Department of Biochemistry and Molecular Biology Faculty Papers

Purinergic signaling relies on ATP release through exocytosis and large-pore channels. Large-pore channels permeate both small anions like chloride and large signaling molecules like ATP, but how this broad cargo selectivity is structurally controlled remains elusive. Here we investigate PANX1, a prototypical large-pore channel, and uncover structural plasticity at the extracellular entrance formed by seven tryptophan (W74) residues. The W74 sidechains are flexible, sampling conformations that range from a constricted state permissive only to chloride to a dilated state compatible with ATP. These states are coupled to variable cation-π interactions between W74 and arginine 75 (R75), suggesting a mechanism for …

You Have To Cut&Walk; Before You Can Cut&Run;: Regulation Of Gene Expression By The Vitamin D Receptor (Vdr) In The Annual Killifish, Austrofundulus Limnaeus, Rosalia Tanori

Dissertations and Theses

The annual killifish, Austrofundulus limnaeus, found in ephemeral ponds in South America, possesses a remarkable ability to survive extended periods without water and oxygen. This ability is associated with developmental dormancy known as diapause. Numerous genetic and environmental factors influence the entry into diapause and tolerance to environmental stress. Among these is vitamin D3 signaling mediated by the vitamin D receptor (VDR), which plays a crucial role in regulating entry into diapause and the continuous development of an embryo in a temperature-dependent manner. Vitamin D3 signaling influences a variety of physiological processes in vertebrates. While extensively characterized in mammalian …

Buffer Vs. Swabs: Efficacy Of Carrier Nucleic Acids In Robotic Extractions, Shawn Cecil

Honors Projects

This study compared the efficiency of two carrier nucleic acid methods, specifically using salmon sperm DNA (spDNA), in robotic solid-phase extractions of cotton swab samples. Robotic extractions reduce processing time and workload but result in substantially lower DNA recovery than manual organic extraction. This research tested 10 µg of spDNA being added to the lysis buffer or pre-treating the swabs with it before DNA was added. Both methods showed a significant increase in recovery compared to extractions with no carrier. In the buffer extractions, recovery ranged from 69.4% to 117.5% and the swabs being pre-treated ranged from 84.2% to 125.8% …

Molecular Pathway Dysregulation In Chronic Liver Disease: Metabolic And Mechanotransductive Drivers Of Hepatic Pathophysiology, Samantha Harvat

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Metabolic dysfunction–associated steatotic liver disease (MASLD) represents a rapidly growing cause of chronic liver injury, yet the molecular interactions linking metabolic stress, inflammation, fibrosis, and hepatocellular carcinoma (HCC) remain incompletely defined. This thesis integrates transcriptomic analyses across multiple GEO datasets to identify coordinated metabolic, inflammatory, and mechanotransductive pathways that collectively drive disease progression.

Analysis of human liver biopsy datasets (GSE126848 and GSE89632) revealed consistent suppression of glycolysis, β-oxidation, and oxidative phosphorylation across MASLD and MASH samples, accompanied by modest compensatory TCA cycle activation. These alterations reflect impaired metabolic flexibility, mitochondrial stress, and increased ROS susceptibility. Concurrently, cytokine-network enrichment demonstrated activation …

Evaluating The Effectiveness Of An Air Purification System In Reducing Bacterial Chondronecrosis With Osteomyelitis Lameness In Broiler Chickens, Abdulaziz Ali Alqahtani

Graduate Theses and Dissertations

Bacterial chondronecrosis with osteomyelitis (BCO) is the primary cause of lameness in commercial broiler production and has a profound impact on animal welfare and cost-effectiveness. The purpose of this experiment was to examine the effect of an air purification system on mitigating BCO lameness in broiler chickens. One thousand eight hundred broiler chicks were reared in two side-by-side research barns. Eight air filtration units were installed in one building, and none in the other. Treatment groups in both houses included positive control birds on wire flooring to induce BCO, as well as negative control, feed additive, vaccination, and a combination …

Exploring The Growth Dynamics Of Streptococcus Mutans In Diverse Environmental Conditions, Vanessa Escudero

Theses and Dissertations

Dental caries, a prevalent oral health issue, is primarily associated with the growth of Streptococcus mutans, a Gram-positive bacterium that grows under various oral environments. The primary objective of this study was to evaluate the impact of different beverages and mechanical cleaning on the growth of S. mutans, which plays a crucial role in tooth decay. Using a nano-spectrophotometer we analyzed bacterial growth by constructing growth curves under different conditions, including exposure to cranberry juice, Hawaiian juice, and mechanical brushing.

The study was designed to mimic real-world oral conditions by testing S. mutans in four distinct environments. First, we established …

Development Of Novel Small Molecule Therapeutics For Myotonic Dystrophy, Xhesika Azis

Biological Sciences

Myotonic Dystrophy type 1 (DM1) results from expanded CUG repeat RNA that sequesters MBNL proteins and disrupts alternative splicing. Small molecules that bind toxic repeat RNA and release MBNL proteins represent a promising therapeutic strategy. This thesis examines newly synthesized modified polycyclic compounds (MPCs) engineered to target CUG RNA with enhanced specificity and efficacy. Through Suzuki–Miyaura coupling and benzoquinone-mediated cyclization, MPC03 was synthesized and characterized by NMR and LC–MS.

The biological activity of these compounds was assessed in DM1 patient-derived myotubes and fibroblasts. MPC03 consistently produced dose-dependent rescue of multiple MBNL-regulated exons, restoring splicing patterns toward those observed in healthy …

Transcription Factors And Regulatory Proteins In The Control Of Eukaryotic Gene Expression, Maya M. Minkara

Honors Theses

Transcription factors (TFs) function as precision switches that integrate signaling inputs, chromatin state, and protein homeostasis to control gene expression. This thesis unites three interconnected research themes: (1) mechanistic studies of the ubiquitin-proteasome system (UPS) in regulating eukaryotic TFs, focusing on polymerase-associated Factor 1 (Paf1) and TATA-box binding protein-associated factor 2 (Taf2); (2) identification of biomarker genes within odor-related TF networks; and (3) integration of published undergraduate research linking molecular regulation, bioinformatics, and synthetic biology. These themes are purposefully structured so that mechanistic insight into TF control sets up network-level discovery and, in turn, motivates applied and translational directions. In …

Investigating The Impacts Of Azole Antifungals On Growth Of Cryptococcus Neoformans, Gnanambika Sindhe

All Theses

Cryptococcus neoformans, an opportunistic fungal pathogen is responsible for cryptococcosis, leading to approximately 181,000 deaths annually, predominantly in regions such as Sub-Saharan Africa. Fluconazole, a widely used fungistatic azole, is often administered due to its relative affordability and lower toxicity. However, resistance to fluconazole in C. neoformans can arise through aneuploidy, complicating treatment efforts. This study aims to deepen our understanding of resistance mechanisms to azole drugs by comparing fluconazole with other azoles, including both clinical and agricultural azole antifungals. Disk diffusion assays were performed to evaluate the ability of C. neoformans to develop resistance to these compounds, focusing …

Context Dependent Regulation Of Dicer Function During Oocyte-To-Embryo Transition, Nick A. Newkirk

Dissertations and Theses (Open Access)

Over two decades ago, Dicer was discovered as the primary enzyme responsible for the generation of small RNAs known as the microRNAs (miRNAs) and short interfering RNAs (siRNAs). Spatiotemporal regulation of Dicer-dependent small-RNA biogenesis affects many aspects of biology, including aging, disease progression, fertility, and cancer. Interestingly, a distinct population of Dicer-dependent small RNAs, known as the endogenous siRNAs (endo-siRNAs), are uniquely abundant in the germ cells and gametes, and are critical for normal fertility. Despite their function regulating new life, the mechanisms controlling their biogenesis and subsequent germ cell functions remain poorly defined. Work to parse these mechanisms in …

Exploring Glycosomes As Therapeutic Targets For Trypanosoma Brucei, Sabrina Sutton Pizarro

All Dissertations

Trypanosoma brucei is a protozoan parasite which causes human African trypanosomiasis and the livestock wasting disease, nagana. These parasites have highly specialized peroxisomes, called glycosomes, which house a variety of essential metabolic pathways, including glycolysis. Glycolysis is the sole means of energy production in the infective life stage of T. brucei making glycosomes and the glycolytic pathway promising targets for therapeutic strategies. In this work, we have studied the glycosome as a therapeutic target from multiple perspectives. The first portion of this work addresses drug trafficking. The efficacy of small-molecule inhibitors of glycosomal enzymes is restricted by the rate of …

A Molecular Mechanism Of Epithelial To Mesenchymal Transition (Emt): An Evidence Based Lesson Applying Molecular Biology Through The Lens Of Cancer, Sophie Hasson, Melissa Rowland-Goldsmith

Open Educational Resources

This lesson aims to strengthen students’ critical thinking and molecular biology data analysis skills as well as their understanding of concepts related to the hallmark of cancer: tissue invasion and metastasis. Students begin by learning about the invasion of cancer cells, Epithelial-Mesenchymal Transition (EMT), and an important protein involved in EMT: E-cadherin. They then apply molecular biology knowledge to analyze data from multiple papers to infer the relationship between Snail and E-cadherin in different types of cancers. Next, they continue to interpret data from many papers to determine that a repressor transcription factor is present during EMT in cancer cells …

Mitochondria-Mediated Epigenetic Transfer Between Chondrosarcoma And Wild-Type Cells, Caleb C. J. Wyckoff

Biomedical Sciences Theses & Dissertations

Glioblastoma (GB), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), cholangiocarcinoma, and chondrosarcoma (CS) cancers all contain mutations in the gene isocitrate dehydrogenase 2 (IDH2). The mutant IDH2 enzyme exhibits transformation of alpha-ketoglutarate (αKG) into the oncometabolite D-2-hydroxyglutarate (D2HG) in the mitochondria of these cancers. Mitochondrial-mediated transfer between cancer cells and recipient cells is a significant event that impacts the physiology of the receiving cell, specifically the epigenetic landscape. Previous experiments indicating increased DNA methylation in mesenchymal stem cells exposed to IDH1 or IDH2 conditioned medium underscore the potential role of D2HG to alter methylation states. Additionally, the presence of …

Dna Extrusion Size Determines Pathway Choice During Cag Repeat Expansion, Mayuri Bhatia, Ashutosh S. Phadte, Anna Lakhina, Anthony R. Monte Carloi Iii, Sarah Barndt, Anna Pluciennik

Department of Biochemistry and Molecular Biology Faculty Papers

DNA triplet repeat expansion causes several primarly neurological disorders like Huntington's disease, myotonic dystrophy type 1, and fragile-X related disorders. There is general consensus that recognition of extrahelical extrusions or hairpin-loop structures (formed by strand slippage) by the DNA mismatch repair protein MutSβ leads to repeat expansion by a mutagenic process. By contrast, the FAN1 nuclease attenuates triplet repeat expansion, the molecular basis of which was explained by our recent finding that FAN1 nuclease cleaves and initiates removal of extrahelical extrusions. Here we show that extrusions containing two or more triplet repeats are subject to recognition and processing by either …

Liver-Directed Base Editing Of Abcc6 Prevents Ectopic Calcification In A Variant-Humanized Mouse Model Of Pseudoxanthoma Elasticum, Lauren C. Testa, Dora Obiri-Yeboah, Hooda Said, Ping Qu, Michael A. Levine, Mohamad-Gabriel Alameh, Kiran Musunuru, Qiaoli Li, Xiao Wang

Department of Biochemistry and Molecular Biology Faculty Papers

Pseudoxanthoma elasticum (PXE) is an autosomal recessive connective tissue disorder characterized by ectopic calcification of elastic fibers throughout the skin, retina, and arteries. It is caused by pathogenic variants in ABCC6 , which encodes a transmembrane transporter that primarily localizes to hepatocytes. Loss of ABCC6 function in hepatocytes leads to systemic deficiency of inorganic pyrophosphate (PPi), a potent inhibitor of calcification; such depletion of PPi from the circulation is responsible for multisystemic ectopic calcification seen in PXE. Therefore, liver-targeted variant correction by genome editing and subsequent restoration of systemic PPi may offer a one-and-done therapeutic approach for PXE. The ABCC6 …

Chronosort: Revealing Hidden Dynamics In Alphafold3 Structure Predictions, Matthew J. Argyle, William P. Heaps, Corbyn Kubalek, Spencer Gardiner, Bradley C. Bundy, Dennis Della Corte

Faculty Publications

Protein function emerges from dynamic conformational changes, yet structure prediction methods provide only static snapshots. While AlphaFold3 (AF3) predicts protein structures, the potential for extracting dynamic information from its ensemble predictions has remained underexplored. Here, we demonstrate that AF3 structural ensembles contain substantial dynamic information that correlates remarkably well with molecular dynamics simulations (MD). We developed ChronoSort, a novel algorithm that organizes static structure predictions into temporally coherent trajectories by minimizing structural differences between neighboring frames. Through systematic analysis of four diverse protein targets, we show that root-mean-square fluctuations derived from AF3 ensembles can correlate strongly with those from MD …

Parameterizing Ion–Lipid Interactions From Local Clusters To Reproduce Experimental Bulk Properties Of Lipid Bilayers, W. Matthew Saunders

USF Tampa Graduate Theses and Dissertations

Phospholipids are the main component of cell membranes, providing a delimiting boundary for cells from their environments or from their organelles from the cytosol. Thiscompartmentalization allows cells to maintain quite different solutions within their cells and organelles, including different mixtures dissolved ions. Consequently, these membranes are constantly flanked by complex mixtures of salts at varied concentrations. To study membrane structure, one cannot neglect the contribution of the salts in the local solution. Ions perturb bilayer structure via specific interaction with the phospholipids, primarily with the headgroups. Experimental studies of these systems are somewhat at odds — scattering experiments with different …

Improving Coral Restoration Outcomes Through Novel Molecular Applications, Matthew H. Gamache

USF Tampa Graduate Theses and Dissertations

Coral reef ecosystems are declining globally from numerous stressors, including localized pollution, disease, and marine heatwaves induced by climate change. To preserve these ecosystems, it is critical to identify corals that can withstand stressors—primarily future marine heatwaves—and prioritize them for coral restoration efforts until these stressors are mitigated. Coral responses to thermal stress can be influenced by several partners, including mutualistic microalgae and a vast prokaryotic community. Here, I use advanced molecular techniques to examine which partners (coral host, algal symbiont, and microbial communities) are associated with coral health, how they contribute to holobiont physiology, and their potential to increase …

Screening For Potential Plant Growth‐Promoting Rhizobacteria (Pgpr)-Assisted Phytoremediation To Mitigate Lead Toxicity In Uae Soils, Zeinab Mohamed Abdalla

Theses

This study investigates the potential of lead (Pb)-tolerant actinobacteria that possess 1-aminocyclopropane-1-carboxylate deaminase (ACCD) activity and plant growth-promoting (PGP) traits to serve as a biological tool for enhancing the growth of corn (Zea mays L.) under Pb stress. The primary objective of this research was to isolate and characterize novel, Pb-tolerant, rhizosphere-competent actinobacteria and to evaluate their efficacy in mitigating Pb toxicity, reducing its uptake, and promoting biomass accumulation in corn grown in contaminated soil. A total of 43 actinobacterial isolates were obtained from Pb-contaminated rhizosphere soil and screened for Pb tolerance, rhizosphere competence, ACCD activity, and PGP traits. …

Targeting The Bcl2 Family: Advances And Challenges In Bh3 Mimetic-Based Therapies, Nabanita Mukherjee, James Sheetz, Yiqun Shellman

Student Papers, Posters & Projects

The BCL2 family of proteins plays a pivotal role in regulating apoptosis and cellular homeostasis, making them critical therapeutic targets in cancer and other diseases characterized by pathological cell survival. BH3 mimetics, small molecules that selectively inhibit anti-apoptotic BCL2 family members, have achieved significant clinical success, particularly in hematologic malignancies. However, several challenges remain, including resistance mechanisms, toxicity (such as MCL1 inhibitor-associated cardiotoxicity), and the intricate balance between apoptotic and non-apoptotic functions. This review provides a comprehensive overview of BCL2 family biology, the development and clinical application and outcomes of BH3 mimetics, and the emerging resistance mechanism known as double-bolt …