Biochemistry, Biophysics, and Structural Biology Commons^™

Evaluation Of Extracellular Matrix Composition And Rheology As Determinants Of Growth, Invasion, And Response To Photodynamic Therapy In 3d Cell Culture Models Of Pancreatic Ductal Adenocarcinoma, Gwendolyn M. Cramer

Graduate Doctoral Dissertations

Pancreatic ductal adenocarcinoma (PDAC) is a notoriously lethal disease characterized by prominent stromal involvement, which plays complex roles in regulating tumor growth and therapeutic response. The extracellular matrix (ECM)-rich stroma has been implicated as a barrier to drug penetration, although stromal depletion strategies have had mixed clinical success. It remains less clear how biophysical interactions with the ECM regulate invasive progression and susceptibilities to specific therapies. Here, an integrative approach combining 3D cell culture and quantitative imaging techniques is used to evaluate invasive behavior and motility as determinants of response to classical chemotherapy and photodynamic therapy (PDT), in which light …

Serine-Dependent Sphingolipid Synthesis Is A Metabolic Liability Of Aneuploid Cells, Sunyoung Hwang, H. Tobias Gustafsson, Ciara O’Sullivan, Gianna Bisceglia, Xinhe Huang, Christian Klose, Andrej Schevchenko, Robert C. Dickson, Paola Cavaliere, Noah Dephoure, Eduardo M. Torres

Molecular and Cellular Biochemistry Faculty Publications

Aneuploidy disrupts cellular homeostasis. However, the molecular mechanisms underlying the physiological responses and adaptation to aneuploidy are not well understood. Deciphering these mechanisms is important because aneuploidy is associated with diseases, including intellectual disability and cancer. Although tumors and mammalian aneuploid cells, including several cancer cell lines, show altered levels of sphingolipids, the role of sphingolipids in aneuploidy remains unknown. Here, we show that ceramides and long-chain bases, sphingolipid molecules that slow proliferation and promote survival, are increased by aneuploidy. Sphingolipid levels are tightly linked to serine synthesis, and inhibiting either serine or sphingolipid synthesis can specifically impair the fitness …

Characterization Of Calcium Homeostasis Parameters In Trpv3 And Cav3.2 Double Null Mice, Aujan Mehregan

Masters Theses

In mammals, calcium influx is required for oocyte maturation and egg activation, as it supports the persistent calcium oscillations induced by fertilization. These oscillations are required for the initiation of embryo development. The molecular identities of the plasma membrane calcium-permeant channels that underlie calcium influx are not established. Among these channels, Transient Receptor Potential Vanilloid, member 3 (TRPV3) allows divalent cations, namely strontium (Sr²⁺) and calcium (Ca²⁺) with high permeability, into cells, and its expression pattern seems to predict an essential role in the initiation of development. Another channel that was identified to be expressed in …

Regulation Of Gene Expression By Rna Binding Proteins And Micrornas, Kyle Cottrell

Arts & Sciences Electronic Theses and Dissertations

Regulation of gene expression is essential to life. Post-transcriptional regulation of gene expression is a complex process with many inputs that lead to changes in localization, translation and stability of mRNAs. The translation and stability of many mRNAs is regulated by cis-elements, such as mRNA-structure or codon optimality; and by trans-acting factors such as RBPs and miRNAs. Here I report on the complex interactions between RBPs, miRNAs and characteristics of their target mRNAs in respect to effects on translation and RNA stability.

Using a reporter based approach we studied modulation of microRNA-mediated repression by various mRNA characteristics. We observed the …

Metabolic Reprogramming Of Pancreatic Ductal Adenocarcinoma Cells In Response To Chronic Low Ph Stress, Jaime Abrego

Theses & Dissertations

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal of all cancers with a 5-year survival rate of only 8.2%. This is because PDAC is diagnosed in its advanced stages and is characterized by radio and chemotherapy resistance. Aggressiveness of PDAC tumors is attributed to its high metabolic phenotype, which is characterized by increased glycolysis rate and lactate secretion, while oxidative metabolism is reduced. These metabolic features are required to fulfill the biosynthetic demands of proliferating PDAC cells. However, this increase in metabolic activity results in acidification of the extracellular space because the dense fibrotic stroma of PDAC tumors limits …

Binding Affinity And Specificity Of Sh2 Domain Interactions In Receptor Tyrosine Kinase Signaling Networks, Tom Ronan

McKelvey School of Engineering Theses & Dissertations

Receptor tyrosine kinase (RTK) signaling mechanisms play a central role in intracellular signaling and control development of multicellular organisms, cell growth, cell migration, and programmed cell death. Dysregulation of these signaling mechanisms results in defects of development and diseases such as cancer. Control of this network relies on the specificity and selectivity of Src Homology 2 (SH2) domain interactions with phosphorylated target peptides. In this work, we review and identify the limitations of current quantitative understanding of SH2 domain interactions, and identify severe limitations in accuracy and availability of SH2 domain interaction data. We propose a framework to address some …

Mechanistic Insights Into The Regulation Of Mitochondrial Fission By Cyclin C, Vidyaramanan Ganesan, Katrina F Cooper, Randy Strich

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Cyclin C is a component of the mediator complex of RNA polymerase II that localizes to the nucleus under normal conditions. In response to stress, cyclin C translocates to the cytosol and mitochondria and mediates stress‐induced mitochondrial fission and apoptosis. The molecular mechanisms by which cyclin C induces mitochondrial fission are unknown. Using in vitro experimental approaches, we sought to investigate the mechanistic basis of cyclin C mediated mitochondrial fission.

Translocation Of Cyclin C During Oxidative Stress Is Regulated By Interactions With Multiple Trafficking Proteins, Daniel G J Smethurst, Katrina F Cooper, Randy Strich

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Eukaryotic cells take cues from their environment and interpret them to enact a response. External stresses can produce a decision between adjusting to behaviors which promote surviving the stress, or enacting a cell death program. The decision to undergo programmed cell death (PCD) is controlled by a complex interaction between nuclear and mitochondrial signals. The mitochondria are highly dynamic organelles that constantly undergo fission and fusion. However, a dramatic shift in mitochondrial morphology toward fission occurs early in the PCD process. We have identified the transcription factor cyclin C as the biochemical trigger for stress‐induced mitochondrial hyper‐fragmentation in yeast (Cooper …

The Role Of Mapk And Scf In The Destruction Of Med13 In Cyclin C Mediated Cell Death, David C Stieg, Stephen D Willis, Joseph Scuorzo, Mia Song, Vidyaramanan Ganesan, Randy Strich, Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

In response to stress, the yeast¹ and mammalian² cyclin C translocate from the nucleus to the cytoplasm, where it associates with the GTPase Drp1/Dnm1 to drive mitochondrial fragmentation and apoptosis. Therefore, the decision to release cyclin C represents a key life or death decision. In unstressed cells, the cyclin C‐Cdk8 kinase regulates transcription by associating with the Mediator of RNA polymerase II. We previously reported that the Mediator component Med13 anchors cyclin C in the nucleus³. Loss of Med13 function leads to constitutive cytoplasmic localization of cyclin C, resulting in fragmented mitochondria, hypersensitivity to stress and …

Snf1 Dependent Destruction Of Med13 Is Required For Programmed Cell Death Following Oxidative Stress In Yeast, Stephen D Willis, David C Stieg, R. Shah, Randy Strich, Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

All eukaryotic cells, when faced with unfavorable environmental conditions, have to decide whether to mount a survival or cell death response. The conserved cyclin C and its kinase partner Cdk8 play a key role in this decision. Both are members of the Cdk8 kinase module that, along with Med12 and Med13, associate with the core mediator complex of RNA polymerase II. In S. cerevisiae, oxidative stress triggers Med13 destruction¹, which thereafter releases cyclin Ci nto the cytoplasm. Cytoplasmic cyclin C associates with mitochondria where it induces hyper-fragmentation and programmed cell death². This suggests a model in …

9-Aminoacridine Inhibits Ribosome Biogenesis And Synergizes With Cytotoxic Drugs To Induce Selective Killing Of P53-Deficient Cells, Leonid Anikin, Dimitri G Pestov

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Common cancer treatments target rapidly dividing cells and do not discriminate between cancer and normal host cells. One approach to mitigating negative side‐effects of cancer treatment is to temporarily arrest cell cycle progression and thus protect normal cells during cytotoxic treatments, a concept called cyclotherapy. We recently proposed that transient inhibition of post‐transcriptional steps of ribosome biogenesis (RBG) can be used to selectively arrest p53‐positive host cells and not p53‐null cancer cells. In this study, we investigated whether cytoprotective RBG inhibition can be achieved through small molecule treatment.

The Regulation Of Extracellular Amyloid-Β Levels By Ionotropic Glutamatergic Transmission In An Alzheimer’S Disease Mouse Model, Jane Cecelia Hettinger

Arts & Sciences Electronic Theses and Dissertations

Brain extracellular concentration of the peptide amyloid-β (Aβ) is a major contributor to Alzheimer’s disease (AD) pathogenesis. High Aβ levels in the extracellular space precipitate aggregation of the peptide into soluble and insoluble toxic species. This process begins decades before cognitive impairment and triggers the cascade of pathology that eventually leads to AD. Synaptic activity is key to the regulation of extracellular Aβ levels. Presynaptic activity drives the production of Aβ, while postsynaptic receptor activation exhibits more nuanced regulation. For example, high levels of NMDA receptor (NMDA-R) activation have been shown to decrease Aβ production through the extracellular signal-regulated kinase …

Role Of Ezrin In Colorectal Cancer Cell Survival Regulation, Premila Leiphrakpam

Theses & Dissertations

Colorectal cancer (CRC) is the second most common cause of cancer related deaths in the United States, mainly due to metastasis to the distant organ sites. However, the molecular basis of CRC metastasis is poorly understood. Therefore, identification and characterization of novel potential anti-cancer therapeutic targets CRC is of urgent need. Utilizing a 2D-DIGE proteomics approach ezrin was identified as a protein that is differentially expressed between primary colon tumors xenografts, orthotopically implanted in athymic nude mice, and corresponding and liver metastatic deposits. Ezrin, a cytoskeletal protein belonging to the ezrin–radixin–moesin (ERM) family plays important roles in cell motility, invasion …

Insights Into The Molecular Roles Of Zika Virus In Human Reproductive Complications And Congenital Neuropathologies, Rajendra Ghardbaran, Latchman Somenarain

Publications and Research

The recent upsurge in the association of congenital neurological disorders and infection by the Zika virus (ZIKV) has resulted in increased research focus on the biology of this flavivirus. Studies in animal models indicate that ZIKV can breach the placental barrier and selectively infect and deplete neuroprogenitor cells (NPCs) of the developing fetus, resulting in changes of brain structures, reminiscent of human microcephaly. In vitro and ex vivo studies using human cells and tissues showed that human NPCs and placental cells are targeted by ZIKV. Also of concern is the impact of ZIKV on human reproductive structures, with the potential …

The Pul37 Tegument Protein Guides Alphaherpesvirus Retrograde Axonal Transport To Promote Neuroinvasion, Alexsia L. Richards, Patricia J. Sollars, Jared D. Pitts, Austin M. Stults, Ekaterina E. Heldwein, Gary E. Pickard, Gregory A. Smith

School of Veterinary and Biomedical Sciences: Faculty Publications

A hallmark property of the neurotropic alpha-herpesvirinae is the dissemination of infection to sensory and autonomic ganglia of the peripheral nervous system following an initial exposure at mucosal surfaces. The peripheral ganglia serve as the latent virus reservoir and the source of recurrent infections such as cold sores (herpes simplex virus type I) and shingles (varicella zoster virus). However, the means by which these viruses routinely invade the nervous system is not fully understood. We report that an internal virion component, the pUL37 tegument protein, has a surface region that is an essential neuroinvasion effector. Mutation of this region rendered …

Nuclear Genome Size Diversity Of Marine Invertebrate Taxa Using Flow Cytometric Analysis, Kyle Roebuck

HCNSO Student Theses and Dissertations

Genomic analysis provides a substantial amount of information on evolutionary history, novel genes, transcriptomic expression and regulation in response to environmental stimuli, how efficiently organisms utilize their genome, and directional genome evolution. Genome size analysis serves as the first step in the sequencing process, because sequencing and annotation costs are directly correlated with genome size. Invertebrates represent the vast majority of faunal diversity on the planet, and, to a greater extent, the marine environment, although they are vastly understudied when compared to vertebrate genomes. Flow cytometry is a widely used, reliable, and accurate means of estimating genome sizes and has …

One-Step Hot Formamide Extraction Of Rna From Saccharomyces Cerevisiae, Daniel Shedlovskiy, Natalia Shcherbik, Dimitri G Pestov

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Current methods for isolating RNA from budding yeast require lengthy and laborious steps such as freezing and heating with phenol, homogenization with glass beads, or enzymatic digestion of the cell wall. Here, extraction with a solution of formamide and EDTA was adapted to isolate RNA from whole yeast cells through a rapid and easily scalable procedure that does not require mechanical cell lysis, phenol, or enzymes. RNA extracted with formamide-EDTA can be directly loaded on gels for electrophoretic analysis without alcohol precipitation. A simplified protocol for downstream DNase treatment and reverse transcription reaction is also included. The formamide-EDTA extraction of …

Endocytic Trafficking Of The Amyloid Precursor Protein In Rat Cortical Neurons, Sahily Reyes

Dissertations & Theses (Open Access)

Amyloid-beta (Aβ) aggregation and deposition into extracellular plaques is a hallmark of the most common forms of dementia, including Alzheimer’s disease. The Aβ-containing plaques result from pathogenic cleavage of amyloid precursor protein (APP) by secretases resulting in intracellular production of Aβ peptides that are secreted and accumulate extracellularly. Despite considerable progress towards understanding APP processing and Aβ aggregation, the mechanisms underlying endosomal production of Aβ peptides and their secretion remain unclear. Using endosomes isolated from cultured primary neurons, we determined that the trafficking of APP from the endosomal membrane into internal vesicles of late endosome/multivesicular bodies (MVB) is dependent on …

Zika Virus Encoding Nonglycosylated Envelope Protein Is Attenuated And Defective In Neuroinvasion, Arun Saravanakumar Annamalai, Aryamav Pattnaik, Bikash R. Sahoo, Ezhumalai Muthukrishnan, Sathish Kumar Natarajan, David Steffen, Hiep Vu, Gustavo A. Delhon, Fernando Osorio, Thomas M. Petro, Shi-Hua Xiang, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

ABSTRACT Zika virus (ZIKV), a mosquito-transmitted flavivirus responsible for sporadic outbreaks of mild and febrile illness in Africa and Asia, reemerged in the last decade causing serious human diseases, including microcephaly, congenital malformations, and Guillain-Barré syndrome. Although genomic and phylogenetic analyses suggest that genetic evolution may have led to the enhanced virulence of ZIKV, experimental evidence supporting the role of specific genetic changes in virulence is currently lacking. One sequence motif, VNDT, containing an N-linked glycosylation site in the envelope (E) protein, is polymorphic; it is absent in many of the African isolates but present in all isolates from the …

Zika Virus Encoding Nonglycosylated Envelope Protein Is Attenuated And Defective In Neuroinvasion, Arun S. Annamalai, Aryamav Pattnaik, Bikash R. Sahoo, Ezhumalai Muthukrishnan, Sathish Kumar Natarajan, David Steffen, Hiep Vu, Gustavo Delho, Fernando Osorio, Thomas M. Petro, Shi-Hua Xiang, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Zika virus (ZIKV), a mosquito-transmitted flavivirus responsible for sporadic outbreaks of mild and febrile illness in Africa and Asia, reemerged in the last decade causing serious human diseases, including microcephaly, congenital malformations, and Guillain-Barré syndrome. Although genomic and phylogenetic analyses suggest that genetic evolution may have led to the enhanced virulence of ZIKV, experimental evidence supporting the role of specific genetic changes in virulence is currently lacking. One sequence motif, VNDT, containing an N-linked glycosylation site in the envelope (E) protein, is polymorphic; it is absent in many of the African isolates but present in all isolates from the recent …

Brain Energy Homeostasis And The Regulation Of N-Acetyl-Aspartate Metabolism In Development And Disease, Samantha Zaroff

Graduate School of Biomedical Sciences Theses and Dissertations

N-acetylaspartate (NAA) is a non-invasive clinical marker of neuronal metabolic integrity because of its strong proton magnetic resonance spectroscopy (H-MRS) peak and direct correlation with energetic integrity. Specifically, NAA is used to track the progression of neurodegenerative diseases due to the characteristic reduction of whole brain levels of NAA which occur simultaneously with reduced glucose utilization and mitochondrial dysfunction, but prior to the onset of disease specific pathology. However, NAA will also significantly increase simultaneously with energetic integrity during periods of recovery or remission in applicable disorders, such as traumatic brain injuries. Unfortunately, it remains enigmatic exactly why NAA is …

Detection Of Survival And Proliferation Of Sulfate Reducers Under Simulated Martian Atmospheric And Soil Conditions, Sergio Mosquera Mora

Graduate Theses and Dissertations

Numerous studies have tried to determine the survivability and proliferation of microorganisms under simulated Martian conditions. Furthermore, most of them have been focused on the ability of these microbes to cope with high brines’ salt (NaCl) concentrations inherent of the Martian surface. However, there are not studies related to the ability of bacteria to survive on subsurface environments that have increasing concentrations of sulfate compounds. For this research, a group of microorganisms known as sulfate-reducing bacteria or simply sulfate reducers were chosen due to their ability to use sulfate compounds as terminal electron acceptors to produce metabolic energy, their tolerance …

Characterization Of Notch1 And Pi3k-Pten-Akt/Mtor Pathway Interaction In Head And Neck Squamous Cell Carcinoma, Kyriante' Henry

Dissertations & Theses (Open Access)

Head and neck squamous cell carcinoma (HNSCC) affects various mucosal sites of the upper aerodigestive tract, including the nasal and oral cavities, the nasopharynx, and the oropharynx. More than five hundred thousand new cases of HNSCC occurred in 2011 alone, with 50,000 reported cases in the United States. This trend made HNSCC the seventh most common non-skin cancer worldwide (Ferlay et al., 2015). Although significant epidemiological and pathological advancements have been made, survival rates have not improved much over the last 40 years, leaving a mortality rate that remains at approximately 50%. An unbiased drug screen demonstrated that HNSCC cell …

Cellular Mechanisms Of Ionoregulation In The Gill Of Japanese Medaka And Rainbow Trout, Rebecca Jo Bollinger

Graduate Theses and Dissertations

Euryhaline fishes are capable of adapting to a wide range of salinities such as freshwater, brackish water or seawater. Through the combined effort of the gill, kidney and intestine, they are able to osmoregulate to maintain a constant internal hydromineral balance. As the gill is in direct contact with the external environment, it is continuously working to maintain ion and acid/base balance, gas exchange and eliminate nitrogenous waste. Fish in freshwater are subjected to osmotic water gain and diffusional ion loss across the gill and experience the opposite in seawater. Therefore, the gill exhibits extreme plasticity when experiencing a change …

Determination Of The Effects Of Different Maillard Reaction Products On The Taxonomic Composition Of The Gut Microbiota, Nesreen Hamdan Aljahdali

Graduate Theses and Dissertations

The Maillard Reaction (MR) is a non-enzymatic chemical reaction which results in linkage between the amino group of amino acids and the carbonyl group of reduced sugars. This reaction generates Maillard reaction products (MRPs) which are not present naturally in foods, and are responsible for a range of colors, odors, flavors, and other sensory properties. Conflicting reports of MRPs impacts on human health are probably due to the fact that bioconversion of these digestible molecules by the gut microbiota has been marginally taken into account. This study aimed to determine the effects of different MRPs on rodent’s gut microbiota through16S …

The Functions Of Setd5 And Mir-221 In Embryonic Stem Cell Differentiation, Tsai-Yu Chen

Dissertations & Theses (Open Access)

Embryonic stem cells (ESCs) are a widely used model system to study cellular differentiation because of their pluripotent characteristics, and ESC differentiation is an epigenetic process. In an effort to identify a new epigenetic factor that is required for ESC differentiation, the function of SETD5 in ESCs was studied for this thesis. Results show that SETD5 is essential for retinoic acid (RA)-induced differentiation of mouse ESCs and for RA-induced expression of critical developmental genes (e.g., Hoxa1 and Hoxa2) and neuron-related genes (e.g., Nestin and Pax6). SETD5 was upregulated during ESC differentiation. Additional results demonstrated that SETD5 bound to …

Insights Into The Therapeutic Potential Of Salt Inducible Kinase 1: A Novel Mechanism Of Metabolic Control, Randi Fitzgibbon

Dissertations & Theses (Open Access)

Salt inducible kinase 1 (SIK1) has been considered a stress-inducible kinase since it was first cloned in 1999. Continued efforts since this time have been dedicated to characterizing the structure and function of SIK1. Such research has laid the ground work for our understanding of SIK1 action and regulation in tissue and stimuli dependent manners. The fundamental findings of this dissertation continue in this tradition and include investigations of SIK1 regulatory mechanisms in skeletal muscle cells, the cellular and physiological effects of SIK1 loss of function in vitro and in vivo, and intracellular metabolic and mitochondrial regulation by this …

Transcriptome-Wide Identification Of The Rna-Binding Landscape Of The Chromatin-Associated Protein Parp1 Reveals Functions In Rna Biogenesis, Manana Melikishvili, Julia H. Chariker, Eric C. Rouchka, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Recent studies implicate Poly (ADP-ribose) polymerase 1 (PARP1) in alternative splicing regulation, and PARP1 may be an RNA-binding protein. However, detailed knowledge of RNA targets and the RNA-binding region for PARP1 are unknown. Here we report the first global study of PARP1–RNA interactions using PAR–CLIP in HeLa cells. We identified a largely overlapping set of 22 142 PARP1–RNA-binding peaks mapping to mRNAs, with 20 484 sites located in intronic regions. PARP1 preferentially bound RNA containing GC-rich sequences. Using a Bayesian model, we determined positional effects of PARP1 on regulated exon-skipping events: PARP1 binding upstream and downstream of the skipped exons …

Role Of Heat Shock Transcription Factor 1 In Ovarian Cancer Epithelial-Mesenchymal Transition And Drug Sensitivity, Chase David Powell

USF Tampa Graduate Theses and Dissertations

The heat shock response (HSR) is a robust cellular reaction to mitigate protein damage from heat and other challenges to the proteome. This protective molecular program in humans is controlled by heat shock transcription factor 1 (HSF1). Activation of HSF1 leads to the induction of an array of cytoprotective genes, many of which code for chaperones. These chaperones, known as heat shock proteins (HSPs), are responsible for maintaining the functional integrity of the proteome. HSPs achieve this by promoting proper folding and assembly of nascent proteins, refolding denatured proteins, and processing for degradation proteins and aggregates which cannot be returned …

The Role Of Sgs1 And Exo1 In The Maintenance Of Genome Stability., Lillian Campos-Doerfler

USF Tampa Graduate Theses and Dissertations

Genome instability is a hallmark of human cancers. Patients with Bloom’s syndrome, a rare chromosome breakage syndrome caused by inactivation of the RecQ helicase BLM, result in phenotypes associated with accelerated aging and develop cancer at a very young age. Patients with Bloom’s syndrome exhibit hyper-recombination, but the role of BLM and increased genomic instability is not fully characterized. Sgs1, the only member of the RecQ family of DNA helicases in Saccharomyces cerevisiae, is known to act both in early and late stages of homology-dependent repair of DNA damage. Exo1, a 5′–3′ exonuclease, first discovered to play a role …