Cell Biology Commons^™

Candida Albicans Als5p Amyloid In Host-Microbe Interactions: A Ceanorhabditis Elegans Study, Michael Bois

Dissertations, Theses, and Capstone Projects

Candida albicans, a dimorphic fungus and an opportunistic pathogen, possesses a myriad of adherence factors including members of the agglutinin-like sequence (Als) family of mannoproteins. The adhesin Als5p mediates adhesion to many substrates, and is upregulated during commensal interactions, but is downregulated during active C. albicans infections[1]. An amyloid forming core sequence at residues 325-331 has been shown to be important for Als5p function, because a single amino acid substitution at position 326 (V326N) greatly reduces Als5p-mediated adherence[2]. We evaluated the role of Als5p in host-microbe interactions, using Caenorhabditis elegans as a host model and feeding them Saccharomyces cerevisiae expressing …

Polymerase Alpha Components Associate With Telomeres To Mediate Overhang Processing, Raffaella Diotti

Dissertations, Theses, and Capstone Projects

Telomeres consist of TTAGGG repeats, which end with a 3' G-overhang and are bound by a six-protein complex, known as Shelterin. In humans, telomeres shorten at each cell division, unless telomerase is expressed and able to add telomeric repeats to the 3' G-overhang. However, for effective telomere maintenance, the DNA strand complementary to that made by telomerase must be synthesized. In this study, I focused on the Polα/primase complex, in particular the subunits p68 (POLA2, the regulatory subunit) and p180 (Polα, the catalytic subunit), and their potential roles at telomeres. I was able to detect p180, p68 and OBFC1, a …

The Sex Of The Cell Dictates Its Response, Carlos Ganesh Penaloza

Dissertations, Theses, and Capstone Projects

Male and female differences in frequency of occurrence in disease have perplexed scientists for some time. This in part derives from limitations in the systems in which one can evaluate sex differences. At the organismal level, differences can be hidden by a myriad of extensive and complex factors. Additional limitations exist since most biomedical studies are performed almost exclusively on male subjects, as the female hormonal milieu is intrinsically more variable and too troublesome for routine inclusion in research protocols. Research documenting sex differences continues to grow, and while most researchers suggests that sex hormones are at the core of …

Lipid Dependence In Ras-Driven Tumors, Darin Salloum

Dissertations, Theses, and Capstone Projects

Over past decade, metabolic alterations in cancer cells have received a substantial amount of interest. It had been established that cancer cells undergo a significant amount of metabolic alterations, and some of these alterations are similar to those in normal highly proliferative cells. However, it is becoming more apparent that many of the metabolic alterations are specific to particular oncogenic signaling pathways. Although altered metabolic machinery makes cancer cells more efficient at promoting growth when nutrients are supplied at the sufficient amounts, the dependency of cancer cells on particular metabolic reprogramming deems cancer cells susceptible to disruptions within metabolic network. …

Metabolic Checkpoints In Cancer Cell Cycle, Mahesh Saqcena

Dissertations, Theses, and Capstone Projects

Growth factors (GFs) as well as nutrient sufficiency regulate cell division in metazoans. The vast majority of mutations that contribute to cancer are in genes that regulate progression through the G1 phase of the cell cycle. A key regulatory site in G1 is the growth factor-dependent Restriction Point (R), where cells get permissive signals to divide. In the absence of GF instructions, cells enter the quiescent G0 state. Despite fundamental differences between GF signaling and nutrient sensing, they both have been confusingly referred to as R and therefore by definition considered to be a singular event in G1. Autonomy from …

The Effect Of Drying On Desiccation Tolerance And Late Embryogenesis Abundant Protein Gene Expression In Immature Seeds Of Phalaenopsis Amabilis, Huijing Zhu

Masters Theses

Orchidaceae as the most diverse family of flowering plants are endangered due to losing habitats or destruction of their unique symbiotic living style. Long-term seed storage banks can be a solution for threatened plant species but the stored seeds must tolerate extreme drying and cold. This ability is acquired during the last stage (maturation drying) of seed development and is correlated with a decline in water content and expression of the Late Embryogenesis Abundant (LEA) protein genes. Our goal is to investigate if premature orchid seeds can be artificially induced to become desiccation tolerant and the potential role of LEA …

Blockade Of Mast Cell Activation Reduces Cutaneous Scar Formation, Lin Chen, Megan Schrementi, Matthew J. Ranzer, Traci A. Wilgus, Luisa A. Dipietro

Faculty Publications & Research

Damage to the skin initiates a cascade of well-orchestrated events that ultimately leads to repair of the wound. The inflammatory response is key to wound healing both through preventing infection and stimulating proliferation and remodeling of the skin. Mast cells within the tissue are one of the first immune cells to respond to trauma, and upon activation they release pro-inflammatory molecules to initiate recruitment of leukocytes and promote a vascular response in the tissue. Additionally, mast cells stimulate collagen synthesis by dermal fibroblasts, suggesting they may also influence scar formation. To examine the contribution of mast cells in tissue repair, …

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 …

Effects Of Altering The Peroxisomal Redox State In Models Of Degenerative Disease, Courtney Rose Giordano

Wayne State University Dissertations

Peroxisomes are important regulators of cellular redox balance and function as a signaling platform to regulate anti-aging metabolic and communication networks. In addition the organelle has emerged as a major player in maintaining cellular ROS at an optimal level. At such levels, these ROS are involved in initiation of signaling cascades and that produce an array of anti-aging and disease processes. However, as cells age over time, ROS amass within the peroxisome and elsewhere in the cell. This leads to an imbalance in oxidative homeostasis and results in compromised signaling networks. The goal of this dissertation was to treat disease …

Protein 14-3-3 (Ywha) Isoforms And Their Roles In Regulating Mouse Oocyte Maturation, Santanu De

Biology Faculty Books and Book Chapters

The 14-3-3 (YWHA) is a highly conserved, ubiquitously expressed protein family regulating important cellular processes including cell cycle. This work, for the first time, explored the differential expression and roles of 14-3-3 isoforms during mouse oocyte maturation.

All seven mammalian 14-3-3 isoforms were identified in mouse eggs and ovarian follicular cells including oocytes, by Western blotting. Immunocytochemical and immunohistochemical staining confirmed the presence of all 14-3-3 isoforms in oocytes, eggs and ovarian follicles with characteristic similarities and differences in their distributions.

Mammalian oocytes are arrested at meiosis prophase I by an inhibitory phosphorylation on Cyclin-Dependent Kinase I (CDK1), released by …

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 …

Clinical Features And Outcome Of Sporadic Colorectal Carcinoma In Young Patients: A Cross-Sectional Analysis From A Developing Country, Muhammad Nauman Zahir, Eisha Mahpara Azhar, Sobia Rafiq, Kulsoom Ghias, Munira Shabbir-Moosajee

Department of Biological & Biomedical Sciences

Background: Early onset colorectal carcinoma (CRC) is rare and has been hypothesized to be a biologically and clinically distinct entity personifying aggressive disease and worse survival.
Methods: Data for 131 patients was collected by retrospective chart review. Cox proportional hazard model was used to compute prevalence ratios and 95% confidence intervals.
Results: Early onset sporadic CRC accounted for 32% of all CRC treated in the specified time period. The mean age was 33.3 ± 7.9 years and the male to female ratio was 2 : 1. Colon and rectal cancers accounted for 55% and 45% of patients, respectively. 96% of …

Nel Positively Regulates The Genesis Of Retinal Ganglion Cells By Promoting Their Differentiation And Survival During Development, Chizu Nakamoto, Soh-Leh Kuan, Amy Findlay, Elaine Durward, Zhufeng Ouyang, Masaru Nakamoto, Ewa Zakrewska, Takuma Endo

Biology Faculty Publications

For correct functioning of the nervous system, the appropriate number and complement of neuronal cell types must be produced during development. However, the molecular mechanisms that regulate the production of individual classes of neurons are poorly understood. In this study, we investigate the function of the thrombospondin-1–like glycoprotein, Nel (neural epidermal growth factor [EGF]-like), in the generation of retinal ganglion cells (RGCs) in chicks. During eye development, Nel is strongly expressed in the presumptive retinal pigment epithelium and RGCs. Nel overexpression in the developing retina by in ovo electroporation increases the number of RGCs, whereas the number of displaced amacrine …

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 …

Non-Raft Ac2 Defines A Camp Signaling Compartment That Selectively Regulates Il-6 Expression In Airway Smooth Muscle Cells, Amy S. Bogard, Anna V. Birg, Rennolds S. Ostrom

Pharmacy Faculty Articles and Research

Adenylyl cyclase (AC) isoforms differ in their tissue distribution, cellular localization, regulation, and protein interactions. Most cell types express multiple AC isoforms. We hypothesized that cAMP produced by different AC isoforms regulates unique cellular responses in human bronchial smooth muscle cells (BSMC). Overexpression of AC2, AC3, or AC6 had distinct effects on forskolin (Fsk)-induced expression of a number of known cAMP-responsive genes. These data show that different AC isoforms can differentially regulate gene expression. Most notable, overexpression and activation of AC2 enhanced interleukin 6 (IL-6) expression, but overexpression of AC3 or AC6 had no effect. IL-6 production by BSMC was …

Cellular Coping Mechanisms To Hypoxia In The Longhorn Sculpin (Myoxocephalus Octodecemspinosus) Brain, Kelly Heino

College of Graduate Studies: Theses & Dissertations

The loss of neurological function due to hypoxia remains to be a challenge in many species due to the lack of knowledge and understanding of cellular responses. To investigate cellular responses and survival strategies of the brain during hypoxia and post-hypoxia recovery in a moderate hypoxia-tolerant species, with the hopes of identifying possible therapeutic remedies, thirty Longhorn sculpin, Myoxocephalus octodecimspinosus, were challenged with acute hypoxia (40% O2 saturation for 1 h) and twelve additional sculpin were used as controls (~90% O₂ saturation). Fish were sampled at each of the following time points: control/normoxic conditions (T=0 h); hypoxic conditions …

Paracrine-Rescued Lobulogenesis In Chimeric Outgrowths Comprising Progesterone-Receptor-Null Mammary Epithelium And Redirected Wild-Type Testicular Cells, Robert D. Bruno, Corinne A. Boulanger, Sonia M. Rosenfield, Lisa H. Anderson, John P. Lydon, Gilbert H. Smith

School of Medical Diagnostics & Translational Sciences Publications

We have previously shown that non-mammary and tumorigenic cells can respond to the signals of the mammary niche and alter their cell fate to that of mammary epithelial progenitor cells. Here we tested the hypothesis that paracrine signals from mammary epithelial cells expressing progesterone receptor (PR) are dispensable for redirection of testicular cells, and that re-directed wild-type testicular-derived mammary cells can rescue lobulogenesis of PR-null mammary epithelium by paracrine signaling during pregnancy. We injected PR-null epithelial cells mixed with testicular cells from wild-type adult male mice into cleared fat-pads of recipient mice. The testicular cells were redirected in vivo to …

Dielectric Characterization Of Coastal Cartilage Chondrocytes, Michael W. Stacey, Ahmet C. Sabuncu, Ali Beskok

Bioelectrics Publications

BACKGROUND: Chondrocytes respond to biomechanical and bioelectrochemical stimuli by secreting appropriate extracellular matrix proteins that enable the tissue to withstand the large forces it experiences. Although biomechanical aspects of cartilage are well described, little is known of the bioelectrochemical responses. The focus of this study is to identify bioelectrical characteristics of human costal cartilage cells using dielectric spectroscopy.

METHODS: Dielectric spectroscopy allows non-invasive probing of biological cells. An in house computer program is developed to extract dielectric properties of human costal cartilage cells from raw cell suspension impedance data measured by a microfluidic device. The dielectric properties of chondrocytes are …

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.

The Effect Of Lactic Acid On Mast Cell Function, Andrew J. Spence

Theses and Dissertations

This study shows for the first time the effect that L-(+)-lactic acid has on mast cell activation. Lactic acid is a byproduct of anaerobic glycolysis and is associated with inflammatory environments such as wounds, tumors and, asthma. In this study, pre-treatment with lactic acid altered cytokine production by bone marrow-derived mast cells (BMMC). Specifically, lactic acid enhanced cytokine secretion following IgE cross-linking, but decreased IL-33 mediated cytokine production. These effects were altered by genetic background, since C57BL/6 mast cells demonstrated the aforementioned result, but lactic acid had no effect on IgE-mediated cytokine production in 129/SvJ mast cells. The affected cytokines …

Mitochondrial Dynamics: Exploring A Novel Target Against Myocardial Ischemia-Reperfusion Injury, Yi Dong

Wayne State University Dissertations

Mitochondrial fusion and fission, collectively termed mitochondrial dynamics, are among the core mechanisms responsible for maintaining mitochondrial health and functional integrity. Dynamin-related protein 1 (DRP1) is a key regulator of mitochondrial fission. Recent studies suggest that i) mitochondrial dynamics, particularly, mitochondrial fission, serves as a mediator of cell fate in the setting of ischemia-reperfusion (IR) injury, and, ii) inhibition of DRP1 and mitochondrial fission provides cardioprotection against IR injury. However, the precise role of DRP1 translocation to mitochondria in the pathogenesis of myocardial ischemia-reperfusion injury has not been established.

Using an established model of hypoxia-reoxygenation (HR) in cultured HL-1 cardiomyocytes, …

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 …

The Lipogenic Phenotype Of Her2/Neu-Positive Breast Cancer Cells, Jan Martin Baumann

Legacy Theses & Dissertations (2009 - 2024)

Recent work has shown that HER2/neu-positive breast cancer cells rely on a unique Warburg-like metabolism for survival and aggressive behavior. These cells are dependent on fatty acid (FA) synthesis, show markedly increased levels of stored fats and disruption of the synthetic process results in apoptosis. Supplementation of the growth media with physiological concentrations of saturated FAs induces cell death, whereas HER2-normal cells are not affected. This is particularly interesting in the context of new epidemiological data showing that a diet rich in saturated FAs is positively correlated with the development of HER2-negative disease, but not HER2/neu-positive disease.

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 …

Computational Modeling-Driven Study Of Signaling Pathway Affecting Cleft Formation During Submandibular Salivary Gland Development, Shayoni Ray

Legacy Theses & Dissertations (2009 - 2024)

Branching morphogenesis is a conserved mechanism of mammalian organ development (salivary glands, lungs, mammary glands, pancreas, kidney, etc.), and has been a classic topic of study for generations of developmental biologists. During the process of tissue formation, several cellular and molecular and protein signaling events occur at successive stages enabling proper formation of tissue shape and structure. In order to provide a comprehensive understanding of the process of branching morphogenesis, we need a systems level approach to integrate multifactorial information. My overall global hypothesis is that multiple mathematical modeling approaches can be utilized to extract crucial cellular and tissue level …

Effect Of Long Term Rapamycin Treatment On Mtor Signalling Network In Colon And Liver Of C57bl/6 Mice, John Sorge

Wayne State University Theses

Many studies have investigated the effects of rapamycin on aging and cancer. However, the effects of long-term rapamycin supplementation on a cancer model have not been performed. This is the first study that investigates the effects of long-term supplementation of rapamycin in a cancer model. ACF analysis of colon tissues in mice showed no significant difference between controls and those supplemented with rapamycin. Factors such as energy balance, cellular environment, PI3K/Akt/mTOR pathway, and more have been assessed in this study. The duration of rapamycin supplementation seems to play an important role in the protection against cancer. Ultimately, this study suggests …

Characterization Of Adult Zebrafish Retinal Regeneration Following Two Different Damage Models, Jennifer Lee Thomas

Wayne State University Dissertations

Unlike mammals, zebrafish can regenerate all of their retinal neurons through Müller glial cells, which respond to retinal damage by re-entering the cell cycle to create clusters of progenitor cells. The progenitors continue to proliferate as they migrate to the site of damage, where they ultimately differentiate into new retinal neurons. In contrast, Müller glia of the mammalian retina respond to injury with reactive gliosis, which if persistent, can lead to loss of Müller cell function and devastating vision loss. Despite this, multiple lines of evidence suggest that mammalian Müller glial cells possess a latent ability to regenerate retinal neurons. …