Cell Biology Commons^™

The Effects Of Lipoxin A4 (Lxa4) On Neutrophil Biology In Sepsis, Benedict Wu

Graduate School of Biomedical Sciences Theses and Dissertations

During sepsis, neutrophils are inappropriately activated and have prolonged lifespans, thus becoming dysfunctional. Excessive neutrophil activation can lead to tissue injury while neutrophil dysfunction can lead to decreased free radical production and reduced phagocytosis, preventing the host from clearing preexisting infections. Lipoxin A4 (LXA4) is a specialized pro-resolution mediator which reduces neutrophil migration and expression of proinflammatory mediators. Intact neutrophil functions are critical for the host to efficiently clear invading pathogens. The effects of LXA4 on neutrophil function in sepsis have not been established. Using the cecal ligation and puncture (CLP) model of sepsis, LXA4 administered 1 h after sepsis …

The Role Of Mammalian Cyclin C In Stress Response And Thyroid Disease Progression, Kun Wang

Graduate School of Biomedical Sciences Theses and Dissertations

The cellular response to stress involves changes in gene expression programs as well as the remodeling of subcellular organelles including the mitochondria. Important for this study, the mitochondria undergo extensive fragmentation when the cell is exposed to a variety of stressors. The cyclin C-Cdk8 kinase is a highly conserved transcription factor that associates with the RNA polymerase II holoenzyme. Using cyclin C knockout (CCNC^-/-) mouse embryonic fibroblast (MEF) cells, I revealed that cyclin C is required for the extensive mitochondrial fragmentation following treatment with pro-oxidants or the anti-cancer drug cisplatin. However, Cdk8 is not required for this process …

Regulation Of Nkcc2 Trafficking By Vesicle Fusion Proteins Vamp2 And Vamp3 In The Thick Ascending Limb, Paulo Sebastian Caceres Puzzella

Wayne State University Dissertations

The thick ascending limb (TAL) in the kidney regulates extracellular fluid volume and blood pressure. The Na/K/2Cl cotransporter NKCC2 plays a central role in NaCl absorption by the TAL and blood pressure. NKCC2 trafficking to the apical membrane is a major mechanism to control NKCC2 activity. However, little is known about the proteins that mediate NKCC2 trafficking. Inhibition of the vesicle fusion proteins VAMP2 and VAMP3 blunts the increase in surface NKCC2 expression and NaCl absorption in response to stimulation by cAMP. In other cells, VAMPs mediate fusion of exocytic vesicles with the plasma membrane. Whether VAMP2 and VAMP3 mediate …

A Novel Function For 12-Lipoxygenase In C-Met And Integrin Β4 Axis Crosstalk, Elizabeth Tovar

Wayne State University Dissertations

Cancer cell metastasis is the single most threatening occurrence of tumor progression and predicts patient prognosis as well as survival. Invasion can be regulated by the Met receptor tyrosine kinase (c-Met), integrin beta4, and the lipid enzyme, 12-Lipoxygenase (12-LOX). Therefore we sought to determine if beta4, c-MET and 12-LOX comprise a signaling axis. c-Met is implicated in cancer cell dissemination through regulation of invasion in EMT where cell-cell junctions are disturbed to allow motility. Furthermore, beta4 promotes cellular adhesion to the extracellular matrix through hemidesmosomes. However, the homeostatic signaling functions of beta4's cytoplasmic tail can be hijacked by growth factor …

Basic Features Of A Cell Electroporation Model: Illustrative Behavior For Two Very Different Pulses, Reuben S. Son, Kyle C. Smith, Thiruvallur R. Gowrishankar, P. Thomas Vernier, James C. Weaver

Bioelectrics Publications

Science increasingly involves complex modeling. Here we describe a model for cell electroporation in which membrane properties are dynamically modified by poration. Spatial scales range from cell membrane thickness (5 nm) to a typical mammalian cell radius (10 μm), and can be used with idealized and experimental pulse waveforms. The model consists of traditional passive components and additional active components representing nonequilibrium processes. Model responses include measurable quantities: transmembrane voltage, membrane electrical conductance, and solute transport rates and amounts for the representative "long" and "short" pulses. The long pulse-1.5 kV/cm, 100 μs-evolves two pore subpopulations with a valley at ~5 …

Cellular Regulation Of Extension And Retraction Of Pseudopod-Like Blebs Produced By Nanosecond Pulsed Electric Field, Mikhail A. Rassokhin, Andrei G. Pakhomov

Bioelectrics Publications

Recently we described a new phenomenon of anodotropic pseudopod-like blebbing in U937 cells exposed to nanosecond pulsed electric field (nsPEF). In Ca²⁺ -free buffer such exposure initiates formation of pseudopod-like blebs (PLBs), protrusive cylindrical cell extensions that are distinct from apoptotic and necrotic blebs. PLBs nucleate predominantly on anode-facing cell pole and extend toward anode during nsPEF exposure. Bleb extension depends on actin polymerization and availability of actin monomers. Inhibition of intracellular Ca²⁺ , cell contractility, and RhoA produced no effect on PLB initiation. Meanwhile, inhibition of WASP by wiskostatin causes dose-dependent suppression of PLB growth. Soon after …

Introduction To Fourth Special Issue On Electroporation-Based Technologies And Treatments, Damijan Miklavčič, Lluis M. Mir, P. Thomas Vernier

Bioelectrics Publications

This fourth special electroporation-based technologies and treatments issue of the Journal of Membrane Biology contains reports on recent developments in the field of electroporation by participants in the 7th International Workshop and Postgraduate Course on electroporation based technologies and treatments (EBTT 2013) held in Ljubljana, November 17–23, 2013. The 65 participants included faculty members, invited lecturers, special guests, and young scientists, and students from 16 countries. In addition to lectures on the fundamentals, this year’s sessions included talks on microbial inactivation by pulsed electric fields, modeling of intracellular electroporation, electroporation in food processing, and electrotransfer-facilitated DNA vaccination.

Mechanisms Of Age-Related Inflammation And Cancer : The Synergistic Effect Of Oxidants And Calcium, Donald A. Mccarthy

Legacy Theses & Dissertations (2009 - 2024)

The accumulation of senescent cells during the process of aging has been implicated as causal in numerous age-related pathologies. Senescent cells adopt a secretory phenotype consisting of many factors including matrix remodeling enzymes, growth factors, cytokines, and chemokines. Their secretory nature is the primary reason that they are associated with disease, but it remains unclear why they become so inflammatory. Using primary human fibroblasts cultured to senescence, we mechanistically determined why senescent cells are such potent inducers of inflammation. Our findings indicate that the early production of the cytokine Interleukin 1-α (IL-1α) is central to this transition. We found that …

Molecular Actions Of The Vitamin D Receptor In Breast Cancer, Erika Laporta

Legacy Theses & Dissertations (2009 - 2024)

1,25-Dihydroxyvitamin D (1,25D) exerts anti-cancer actions through the vitamin D receptor (VDR) but the specific targets that mediate these effects remain to be defined. In these studies, growth and genomic responses to 1,25D were evaluated in a cellular model system derived from mammary tumors generated in VDR knockout (KO) and wildtype (WT) mice. WT145 cells (derived from WT tumors) expressed VDR and were growth inhibited by 1,25D, whereas KO240 cells (derived from VDRKO tumors) lacked VDR and were not growth inhibited by 1,25D. KO240 cell clones stably expressing VDR (KOhVDR cells) were sensitized to 1,25D mediated growth arrest. Genomic profiling …

Dephosphorylation Of Iqg1 By Cdc14 Temporally Regulates Actin Ring Formation, Daniel Patrick Miller

Masters Theses

"Cytokinesis is the final step in cell division when the cell separates the cytoplasm by contracting a ring composed of filamentous actin (F-actin) and type II myosin. Iqg1, an IQGAP family member, is an essential scaffolding protein in budding yeast (S. cerevisiae) required for actin recruitment to, and contraction of, the actomyosin ring. Actin is recruited by the calponin homology domain (CHD) in anaphase after Iqg1 is localized to the bud neck. Consensus sites for the cyclin-dependent kinase (CDK) Cdc28 were identified flanking the CHD. This led us to the hypothesis that phosphorylation of Iqg1 by Cdc28 negatively regulates actin …

Regulation Of Inositol Biosynthesis And Cellular Consequences Of Inositol Depletion: Implications For The Mechanism Of Action Of Valproate, Rania M. Deranieh

Wayne State University Dissertations

Inositol is a six-carbon cyclitol that is ubiquitous in biological systems. It is a precursor for the synthesis of numerous biologically important compounds, including inositol phosphates and phosphoinositides that are essential for cell function and viability. Inositol compounds play a role in membrane formation, gene regulation, signaling, regulation of ion channels, and membrane trafficking. Furthermore, inositol regulates hundreds of genes, including those involved in the biosynthesis of inositol and phospholipids. While transcriptional regulation of inositol biosynthesis has been extensively studied and well characterized, regulation of inositol biosynthesis at the enzymatic level has not been addressed. The current study shows that …

The Interactions Between Jak/Stat Signaling Ligands In Drosophila Melanogaster, Qian Chen

Theses and Dissertations--Biology

The development of multi-cellular organisms requires extensive cell-cell communication to coordinate cell functions. However, only a handful of signaling pathways have emerged to mediate all the intercellular communications; therefore, each of them is under an array of regulations to achieve signaling specificity and diversity. One such signaling pathway is the Janus Kinase/ Signal Transducer and Activator of Transcription (JAK/STAT) pathway, which is the primary signaling cascade responding to a variety of cytokines and growth factors in mammals and involved in many developmental processes. This signaling pathway is highly conserved between mammals and Drosophila, …

Tracing Beta Strands Using Strandtwister From Cryo-Em Density Maps At Medium Resolutions, Dong Si, Jing He

Computer Science Faculty Publications

Major secondary structure elements such as α helices and β sheets can be computationally detected from cryoelectron microscopy (cryo-EM) density maps with medium resolutions of 5–10 A˚ . However, a critical piece of information for modeling atomic structures is missing, because there are no tools to detect β strands from cryo-EM maps at medium resolutions. We propose a method, StrandTwister, to detect the traces of β strands through the analysis of twist, an intrinsic nature of a β sheet. StrandTwister has been tested using 100 β sheets simulated at 10 A˚ resolution and 39 β sheets computationally detected from cryo-EM …

A Structure-Function Analysis Of The Arabidopsis Chloroplast Import Protein Attic20, James H. Campbell

Theses and Dissertations (Comprehensive)

Arabidopsis thaliana protein Tic20 (atTic20) is a member of the translocon at the inner envelope membrane of chloroplasts. Evidence to date suggests it is part of the main preprotein conducting aperture in the complex, but its exact role is still debated. To help characterize its role, a protocol optimizing yield and purity of recombinantly expressed atTic20 was developed, and a series of experiments was performed to examine its secondary structure and its ability to interact with chloroplast transit peptides. The attempt to increase protein yield was successful, with growth at 20^oC in the auto-inducing media ZYP-5052 showing the …

Characterizing Dsrna Production In Virus-Infected Fish Cells, Amal Brek Aloufi

Theses and Dissertations (Comprehensive)

Viral dsRNA is produced by almost all viruses sometime during their replicative cycle. These viral nucleic acids are potent inducers of both innate and adaptive immune responses, and are therefore considered important immuno-modulators. Previous studies have shown that viruses produce dsRNA when replicating in mammalian cells; however, to date no one has demonstrated viral dsRNA production in virus infected fish cells. Therefore, the goal of this study is to investigate dsRNA production by fish viruses in fish cells, verifying production and performing initial characterization of the dsRNA molecules being produced. Three different rainbow trout cell lines were used in this …

Development Of Novel Subunit Vaccine Against H5n1 Influenza, Lu Zhang

Graduate Theses and Dissertations

Influenza is a common infectious disease resulting from a frequently mutated RNA virus. Vaccination is currently the most effective method to prevent people from seasonal or pandemic influenza. The production of traditional egg-based influenza vaccine is time-consuming and provides limited effect against new strains. Therefore, it is necessary to develop a rapid method to produce influenza vaccines. We proposed a novel influenza vaccine based on the E.coli expression system. Hemagglutinin (HA) is the major target surface protein of influenza virus for vaccine development. In this study, we sub-cloned the HAs encoding gene into an E. coli expression vector; the signal …

New Insights Into The Roles Of Human Dna Damage Checkpoint Protein Atr In The Regulation Of Nucleotide Excision Repair And Dna Damage-Induced Cell Death, Zhengke Li

Electronic Theses and Dissertations

Integrity of the human genome is frequently threatened by endogenous and exogenous DNA damaging reagents that may lead to genome instability and cancer. Cells have evolved multiple mechanisms to repair DNA damage or to eliminate the damaged cells beyond repair and to prevent diverse diseases. Among these are ataxia telangiectasia and Rad3-related (ATR)-mediated DNA damage checkpoint and nucleotide excision repair (NER) that are the major pathways by which cells handle ultraviolet C (UV-C)- or other exogenous genotoxin-induced bulky DNA damage. However, it is unclear how these 2 pathways may be coordinated. In this study we show that ATR physically interacts …

The Development Of An In Vivo Microdialysis Collection Method Of Cytokines From Brain Tissue, Anthony W. Herbaugh

Graduate Theses and Dissertations

In this thesis, different methods to improve the microdialysis collection procedure for cytokines from brain tissue are presented. The first method was based on stopped flow and results indicating that no significant difference in relative recovery between stopped flow and continuous flow are shown. The second method is an antibody bead-based enhancement method. With the antibody bead-based method, a 3.5 fold increase in the collected concentrations of Chemokine (C-C motif) Ligand 2 (CCL2) were observed. However, there was no significant increase in the in vivo collection efficiency of Interleukin-6 (IL-6) using the antibody enhancement. Finally the development of an in-house …

Bacterial Transcription Factors Grea, Greb And Dksa: Characterization Of Their Interaction With Rna Polymerase And Molecular Mechanism Of Action, Andrey Parshin

Graduate School of Biomedical Sciences Theses and Dissertations

The activity of RNA polymerase (RNAP), the key enzyme of transcription process, is regulated by a large number of transcription factors acting at each step of the transcription cycle. Our research project is focused on studying the structure and function of bacterial transcript cleavage factors GreA, GreB and the stringent response regulator DksA. Gre factors bind in the secondary channel of RNAP in backtracked (inactive) ternary elongation complexes and stimulate the enzyme's intrinsic RNase activity, which is required for suppression of transcription pause and arrest, enhancement of transcription fidelity, and efficient promoter escape. DksA also acts through the RNAP secondary …

Identification Of Proteins Potentially Involved In The Formation Of Lafora Bodies, A Hallmark Of Lafora Disease, Elham Schokraie, Oliver Kötting, Matthew S. Gentry

Molecular and Cellular Biochemistry Presentations

Lafora Disease (LD) is a fatal teenage-onset progressive myoclonus epilepsy. It is characterized by the formation of Lafora bodies (LBs), deposits of abnormally branched, insoluble, hyperphosphorylated glycogen-like polymers that are generally believed to trigger the development of the clinical symptoms of LD. 58% and 35% of the LD cases are caused by mutations in EPM2A (laforin) and EPM2B (malin), respectively. However, little is known about their function in LB formation. Two different mechanisms have been proposed to explain the accumulation of insoluble LBs: first, excessive glycogen phosphorylation and, second, an imbalance between glycogen synthesizing enzymes. The present study aims at …

Modulation Of Bax/Bak Dependent Apoptosis By Sirtuin 3 And Mitochondrial Permeability Transition By Sirtuin 4, Manish Verma

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondria are dynamic organelles that regulate a myriad of cellular functions, including energy production and metabolic regulation. Mitochondria are also a critical regulator of cell death signaling cascades modulating both apoptotic and necrotic cell death. However, what determines which cell death pathway is activated is still unclear. The mitochondrial/intrinsic pathway of apoptosis is dependent on the activation of pro-apoptotic proteins, Bax and Bak, which induce mitochondrial outer membrane permeabilization (MOMP). Once the integrity of outer mitochondrial membrane (OMM) is compromised, pro-apoptotic intermembrane space proteins like cytochrome c, Smac/Diablo, Omi/HtrA2 and AIF are released into the cytoplasm, which activates the post-mitochondrial …

Med13p Prevents Stress-Independent Mitochondrial Hyperfragmentation And Aberrant Apoptosis Activation In Saccharomyces Cerevisiae By Controlling Cyclin C Nuclear Localization, Svetlana Khakhina

Graduate School of Biomedical Sciences Theses and Dissertations

During aging, and as a result of environmental changes, cells are exposed to elevated levels of reactive oxygen species (ROS). High ROS levels induce lipid oxidation, protein aggregation, mitochondrial hyperfragmentation, DNA damage and programmed cell death (PCD), also called apoptosis. PCD is a highly regulated process and its misregulation has been linked to neurodegenerative diseases and cancer development.

Our hypothesis is that cyclin C plays a role in the initiation of apoptosis. During normal conditions, cyclin C represses the transcription of stress response genes (SRG). In response to stress, cyclin C translocates to the cytoplasm where it facilitates mitochondrial hyperfragmentation …

Post-Injury Calcium Chelation Rescues Skeletal Muscle Regeneration In Mice, Matthew D. Magda

Honors Scholar Theses

During aging the ability of skeletal muscle to regenerate after injury wanes until muscle integrity cannot be maintained. In this study it is shown that calcium chelation can restore young-like regenerative ability in an aged mouse model of skeletal muscle regeneration.

Characterization Of Jak, Stat, And Src Interactions In Head And Neck Squamous Cell Carcinoma, Reshma Jaseja, Reshma Jaseja

Dissertations and Theses (Open Access)

Recurrence of Head and Neck Squamous Cell Carcinoma (HNSCC) is common; thus, it is essential to improve the effectiveness and reduce toxicity of current treatments. Proteins in the Src/Jak/STAT pathway represent potential therapeutic targets, as this pathway is hyperactive in HNSCC and it has roles in cell migration, metastasis, proliferation, survival, and angiogenesis. During short-term Src inhibition, Janus kinase (Jak) 2, and signal transducer and activator of transcription (STAT) 3 and STAT5 are dephosphorylated and inactivated. Following sustained Src inhibition, STAT5 remains inactive, but Jak2 and STAT3 are reactivated following their early inhibition. To further characterize the mechanism of this …

Divergent Mechanisms Of Interaction Of Helicobacter Pylori And Campylobacter Jejuni With Mucus And Mucins, Julie Ann Naughton, Karina Mariño, Brendan Dolan, Colm Reid, Ronan Gough, Mary Gallagher, Michelle Kilcoyne, Jared Gerlachscience,, Lokesh Joshi, Pauline Rudd, Stephen Carrington, Billy Bourke, Marguerite Clyne

Articles

Helicobacter pylori and Campylobacter jejuni colonize the stomach and intestinal mucus, respectively. Using a combination of mucus-secreting cells, purified mucins, and a novel mucin microarray platform, we examined the interactions of these two organisms with mucus and mucins. H. pylori and C. jejuni bound to distinctly different mucins. C. jejuni displayed a striking tropism for chicken gastrointestinal mucins compared to mucins from other animals and preferentially bound mucins from specific avian intestinal sites (in order of descending preference: the large intestine, proximal small intestine, and cecum). H. pylori bound to a number of animal mucins, including porcine stomach mucin, but …

Proteomic And Biochemical Studies Of Estrogen-Mediated Signaling And Novel Estrogen Receptor-Interacting Proteins In Breast Cancer Cells, Zhenqi Zhou

Graduate Theses and Dissertations

Estrogen plays essential roles in the growth, development, and homeostasis of a number of tissues, and can also be linked to the growth of breast cancer. The biological activities of estrogen are mediated by estrogen receptors (ERs) ERá and ERâ, and also orphan G-protein-coupled receptor 30 (GPR30). In order to identify novel proteins that are involved in ER-mediated actions of estrogen, we used mass spectrometry-based quantitative proteomic methods to systematically profile global protein expression in responses to E2 (17â-estradiol) stimulation in human breast cancer cell, and identify and characterize cellular novel proteins that are associated with ERs in breast cancer …

New Types Of Morpho-Physiological Changes In Cells Exposed To Nanosecond Pulsed Electric Field, Mikhail A. Rassokhin

Theses and Dissertations in Biomedical Sciences

Exposure of cells to a pulsed electric field (PEF) is the basis of multiple techniques and treatments. Nanosecond pulsed electric field (nsPEF) poses unique characteristics to induce subtle cellular effects while preserving cell integrity. Improving understanding of the mechanisms triggered by nsPEF in cells inspires new applications for the nanosecond pulse technology. Although many effects of nsPEF remain unknown, they can be inferred from morpho-physiologic changes, or cell reshaping, that accompany nsPEF exposure. During the exposure cells undergo reshaping that is manifested in swelling and diffuse blebbing. Recently we identified two new distinct forms of reshaping, pseudopod-like blebbing and microvesiculation, …

Validation Of Antibodies Used To Study Hypoxia Inducible Factors In Two Species Of Fundulus, Jenna D. Hill

LSU New Orleans Theses and Dissertations

Hypoxia inducible factors (HIFs) are transcription factors and the master regulators of oxygen-dependent gene expression in animals. The focus of this thesis is the distribution of HIF protein in tissues of the fish Fundulus heteroclitus and F. grandis, two widespread species that occur in naturally hypoxic waters. Polyclonal antibodies against HIF-1α, HIF-2α, and HIF-3α were tested on proteins made in vitro and on extracts made from several tissues of normoxic and hypoxic fish. Antibodies against HIF-1α and 3α bound specifically to full length protein made in vitro, and produced bands on western blots of nuclear extracts of near …

Dikar-Induced Synthetic Lethality In A Drosophila Model Of Cag Repeat Diseases Does Not Result From An Expression Feedback Loop, Daniel Camacho

Honors Scholar Theses

Human CAG repeat diseases manifest themselves through the common pathology of neurodeneration. This pathological link is attributed to the property shared by all nine of these diseases: an expanded polyglutamine (polyQ) tract. The most evident result of polyQ expansion is protein aggregation, and it is believed that this phenomenon is partly responsible for conferring cytotoxic properties on the mutated protein. Apart from sequestering the mutated protein, cellular aggregates are able to incorporate native proteins via polyQ-mediated aggregation, thus disrupting important cellular pathways. Using Drosophila melanogaster as a disease model, researchers have been able to compile collections of these so-called disease …

Investigations In Enhancing The Reproducibility Of Implantable Amperometric Glucose Biosensors For Mass Production, Dipesh Manharbhai Patel

Honors Scholar Theses

Implantable glucose sensors for Diabetes management should possess several attributes such as linearity, sensitivity, selectivity, long life time and should elicit no negative tissue response. Based on this, the UConn implantable glucose sensor team has developed a 5-layer sensor architecture that simultaneously affords the aforementioned requirements. However, the large scale production of these 5-layer sensors is inhibited by the lack of high sensor-to-sensor reproducibility. Herein, we investigate the origin of sensor-to-sensor irreproducibility and develop methodologies for large-scale fabrication of these devices.