Cell Biology Commons^™

Lenalidomide Targets The T-Cell Co-Stimulatory Pathway To Mediate Immune Modulation, Jessica Marie Mcdaniel

USF Tampa Graduate Theses and Dissertations

T-cells are lymphocytes that make up part of the adaptive arm of the immune system, and are essential for efficient protection from and eradication of viruses and pathogens. T-cells not only play an important role in protection from external agents, but also regulate and prevent activation towards self-peptides and detect and remove erratically growing cells. Alterations in T-cell activation and suppression contribute to auto-immunity, immunocompromised disorders, and cancer progression.

The immune system, and T-cells in particular, provides daily surveillance, recognition and destruction of aberrant cells. Although the immune system is proficient at suppressing malignant progression, tumor cells acquire various methods …

Discovery Of Marinopyrrole A (Maritoclax) As A Selective Mcl-1 Antagonist That Overcomes Abt-737 Resistance By Binding To And Targeting Mcl-1 For Proteasomal Degradation*, Kenichiro Doi, Rongshi Li, Shen-Shu Sung, Hongwei Wu, Yan Liu, Wanda Manieri, Gowdahalli Krishnegowda, Andy Awwad, Alden Dewey, Xin Liu, Shantu Amin, Chunwei Cheng, Yong Qin, Ernst Schonbrunn, Gary W. Daughdrill, Thomas P. Loughran Jr., Said M. Sebti, Hong-Gang Wang

Molecular Biosciences Faculty Publications

The anti-apoptotic Bcl-2 family of proteins, including Bcl-2, Bcl-XL and Mcl-1, are well-validated drug targets for cancer treatment. Several small molecules have been designed to interfere with Bcl-2 and its fellow pro-survival family members. While ABT-737 and its orally active analog ABT-263 are the most potent and specific inhibitors to date that bind Bcl-2 and Bcl-XL with high affinity but have a much lower affinity for Mcl-1, they are not very effective as single agents in certain cancer types because of elevated levels of Mcl-1. Accordingly, compounds that specifically target Mcl-1 may overcome this resistance. In this study, we identified …

Arachidonic Acid Signaling In Invasive And Non-Invasive Breast Cancer Cells, Debarshi Roy

Open Access Theses & Dissertations

Breast cancer is the second largest cause of cancer-related deaths in women all over the world. Epidemiological studies suggest that the consumption of high-fat diets can promote the incidence of breast cancers in both developed and developing countries. In particular, the lipid-rich diet contains arachidonic acid (AA, a C20:4 polyunsaturated fatty acid), which has been shown to be associated with tumor formation in breast tissues. Nevertheless, the actual mechanism by which AA induces the metastatic transformation and malignancy is not well understood. The goal of my dissertation, therefore, is to identify the molecules and unravel the pathways that participate in …

Choreographing The Adenylyl Cyclase Signalosome: Sorting Out The Partners And The Steps, Rennolds S. Ostrom, Amy S. Bogard, Robert Gros

Pharmacy Faculty Articles and Research

Adenylyl cyclases are a ubiquitous family of enzymes and are critical regulators of metabolic and cardiovascular function. Multiple isoforms of the enzyme are expressed in a range of tissues. However, for many processes, the adenylyl cyclase isoforms have been thought of as essentially interchangeable, with their impact more dependent on their common actions to increase intracellular cyclic adenosine monophosphate content regardless of the isoform involved. It has long been appreciated that each subfamily of isoforms demonstrate a specific pattern of “upstream” regulation, i.e., specific patterns of ion dependence (e.g., calcium-dependence) and specific patterns of regulation by kinases (protein kinase A …

Effective Non-Viral Delivery Of Sirna To Acute Myeloid Leukemia Cells With Lipid-Substituted Polyethylenimines, Breanne Landry

Pharmacy Faculty Articles and Research

Use of small interfering RNA (siRNA) is a promising approach for AML treatment as the siRNA molecule can be designed to specifically target proteins that contribute to aberrant cell proliferation in this disease. However, a clinical-relevant means of delivering siRNA molecules must be developed, as the cellular delivery of siRNA is problematic. Here, we report amphiphilic carriers combining a cationic polymer (2 kDa polyethyleneimine, PEI2) with lipophilic moieties to facilitate intracellular delivery of siRNA to AML cell lines. Complete binding of siRNA by the designed carriers was achieved at a polymer:siRNA ratio of ~0.5 and led to siRNA/polymer complexes of …

An Ims/Atp Assay For The Detection Of Mycobacterium Tuberculosis In Urine, Dawn M. Hunter, Daniel V. Lim

Molecular Biosciences Faculty Publications

Background. Although sputum smears are the gold standard for diagnosis of tuberculosis, sensitivity in HIV/TB coinfection cases is low, indicating a need for alternative methods. Urine is being increasingly evaluated. Materials and Methods. A novel method for detecting Mycobacterium tuberculosis (MTB) in synthetic urine using a combined IMS/ATP assay was evaluated. Preliminary work established standard ATP conditions and the sensitivity and specificity of the MTB antibody. Eighty-four blinded samples in four replicate assays were evaluated for the presence of MTB using labeled immunomagnetic beads for capture. Beads were separated, washed, and resuspended in broth and added to a …

Cell Wall Antibiotics Provoke Accumulation Of Anchored Mcherry In The Cross Wall Of Staphylococcus Aureus, Wenqi Yu, Friedrich Götz

Molecular Biosciences Faculty Publications

A fluorescence microscopy method to directly follow the localization of defined proteins in Staphylococcus was hampered by the unstable fluorescence of fluorescent proteins. Here, we constructed plasmid (pCX) encoded red fluorescence (RF) mCherry (mCh) hybrids, namely mCh-cyto (no signal peptide and no sorting sequence), mCh-sec (with signal peptide), and mCh-cw (with signal peptide and cell wall sorting sequence). The S. aureus clones targeted mCh-fusion proteins into the cytosol, the supernatant and the cell envelope respectively; in all cases mCherry exhibited bright fluorescence. In staphylococci two types of signal peptides (SP) can be distinguished: the +YSIRK motif SPlip and the −YSIRK …

Effects Of Binge Alcohol Exposure On Canonical Wnt Signaling During Fracture Repair, Kristen Leigh Lauing

Dissertations

Excessive alcohol consumption is associated with increased fracture risk, delayed bone healing and fracture non-union. Binge alcohol consumption has occurred in 25-40% of all orthopaedic trauma cases. The canonical Wnt pathway, through tight regulation of stabilized beta-catenin, plays an essential and pivotal role in the formation of new bone and cartilage to initiate bone repair. We sought to determine the molecular mechanisms behind alcohol-related fracture complications by testing the hypothesis that binge alcohol exposure deregulates canonical Wnt signaling in the fracture callus, leading to impaired healing.

To test this, C57BL/6 or beta-catenin/TCF-reporter male mice were exposed to intraperitoneal alcohol or …

Probing Molecular Mechanisms Of The Hsp90 Chaperone: Biophysical Modeling Identifies Key Regulators Of Functional Dynamics, Anshuman Dixit, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Deciphering functional mechanisms of the Hsp90 chaperone machinery is an important objective in cancer biology aiming to facilitate discovery of targeted anti-cancer therapies. Despite significant advances in understanding structure and function of molecular chaperones, organizing molecular principles that control the relationship between conformational diversity and functional mechanisms of the Hsp90 activity lack a sufficient quantitative characterization. We combined molecular dynamics simulations, principal component analysis, the energy landscape model and structure-functional analysis of Hsp90 regulatory interactions to systematically investigate functional dynamics of the molecular chaperone. This approach has identified a network of conserved regions common to the Hsp90 chaperones that could …

Using Comparative Genomics For Inquiry-Based Learning To Dissect Virulence Of Escherichia Coli O157:H7 And Yersinia Pestis, David J. Baumler, Lois M. Banta, Kai F. Hung, Jodi A. Schwarz, Eric L. Cabot, Jeremy D. Glasner, Nicole T. Perna

Kai F. Hung

Genomics and bioinformatics are topics of increasing interest in undergraduate biological science curricula. Many existing exercises focus on gene annotation and analysis of a single genome. In this paper, we present two educational modules designed to enable students to learn and apply fundamental concepts in comparative genomics using examples related to bacterial pathogenesis. Students first examine alignments of genomes of Escherichia coli O157:H7 strains isolated from three food-poisoning outbreaks using the multiple-genome alignment tool Mauve. Students investigate conservation of virulence factors using the Mauve viewer and by browsing annotations available at the A Systematic Annotation Package for Community Analysis of …

Bacterial Host Interactions In Cystic Fibrosis, Máire Callaghan, Siobhan Mcclean

Articles

Chronic infection is a hallmark of cystic fibrosis (CF) and the main contributor to morbidity. Microbial infection in CF is complex, due to the number of different species that colonise the CF lung. Their colonisation is facilitated by a host response that is impaired or compromised by highly viscous mucous, zones of hypoxia and the lack of the cystic fibrosis transmembrane regulator (CFTR). Successful dominant CF pathogens combine an effective arsenal to establish infection and counter-attack the host response, together with an ability to adapt readily to an unfavourable environment. Hypermutability is common among CF pathogens facilitating adaptation and as …

Development Of Novel Chemical Tools For Proteasome Biology & A New Approach To 1-Azaspirocyclic Ring System, Lalit Kumar

Theses and Dissertations--Chemistry

The proteasome, a multiprotease complex, is clinically validated as an anticancer target by the FDA approval of bortezomib and carfilzomib for the treatment of multiple myeloma. The emergence of resistance to proteasome inhibitors however remains a major clinical challenge. Recently, distinct types of proteasomes termed ‘intermediate proteasomes’, which contain unconventional mixtures of catalytic subunits, have been implicated with drug resistance of tumor cells. In elucidating the role of intermediate proteasomes in drug resistance, a crucial step is to unequivocally determine the subunit composition of intermediate proteasomes in cells. With this in mind, the goal of the studies reported in this …

Acth: The Uninhibitable (Or Is It)?, Anthony Baglio, Jonathan Forsberg, Daniel Mcfarlane, Justin Nichols, Heather G. Kuruvilla

Science and Mathematics Faculty Presentations

Adrenal corticotropic hormone, or ACTH, is a peptide hormone secreted by the anterior pituitary gland. The full-length peptide is 39 amino acids long. ACTH signals through a G-protein linked receptor in humans, using the adenylyl cyclase pathway. Potassium and chloride channels have also been implicated in human ACTH signaling.

Tetrahymena thermophila are free-living, ciliated ptotozoans. These organisms exhibit avoidance behavior toward many polycationic peptides, which serve as chemorepellents. The reason for this is unknown; however, it is hypothesized that natural predators of T. thermophila secrete polycationic peptides, and that polycation avoidance allows T. thermophila to escape predation. We obtained a …

Protein Folding By 'Levels Of Separation': A Hypothesis, Lesley H. Greene, Terri M. Grant

Chemistry & Biochemistry Faculty Publications

The protein folding process has been studied both computationally and experimentally for over 30 years. To date there is no detailed mechanism to explain the formation of long-range interactions between the transition and native states. Long-range interactions are the principle determinants of the tertiary structure. We present a theoretical model which proposes a mechanism for the acquisition of these interactions as they form in a modified version of ‘degrees of separation’, that we term ‘levels of separation’. It is based on the integration of network science and biochemistry. (C) 2012 Federation of European Biochemical Societies.

Novel Report Of Expression And Function Of Cd97 In Malignant Gliomas: Correlation With Wilms Tumor 1 Expression And Glioma Cell Invasiveness Laboratory Investigation, Archana Chidambaram, Helen L. Fillmore, Timothy E. Van Meter, Catherine I. Dumur, William C. Broaddus

Office of Research Faculty & Staff Publications

Object. The Wilms tumor 1 (WT1) protein—a developmentally regulated transcription factor—is aberrantly expressed in gliomas and promotes their malignant phenotype. However, little is known about the molecular allies that help it mediate its oncogenic functions in glioma cells.

Methods. The authors used short interfering RNA (siRNA) to suppress WT1 expression in glioblastoma (GBM) cells and evaluated the effect of this on GBM cell invasiveness. Gene expression analysis was then used to identify the candidate genes that were altered as a result of WT1 silencing. One candidate target, CD97, was then selected for further investigation into its role by suppressing …

A Preliminary Study On The Potential Of Manuka Honey And Platelet-Rich Plasma In Wound Healing, Scott A. Sell, Patricia S. Wolfe, Andrew J. Spence, Isaac A. Rodriguez, Jennifer M. Mccoll, Rebecca L. Petrella, Koyal Garg, Jeffery J. Ericksen, Gary L. Bowlin

Nursing Faculty Publications

Aim. The purpose of this study was to determine the in vitro response of cells critical to the wound healing process in culture media supplemented with a lyophilized preparation rich in growth factors (PRGF) and Manuka honey. Materials and Methods. This study utilized cell culture media supplemented with PRGF, as well as whole Manuka honey and the medical-grade Medihoney (MH), a Manuka honey product. The response of human fibroblasts (hDF), macrophages, and endothelial cells (hPMEC) was evaluated, with respect to cell proliferation, chemotaxis, collagen matrix production, and angiogenic potential, when subjected to culture with media containing PRGF, MH, Manuka honey, …

Identification Of New Cell Size Control Genes In S. Cerevisiae, Huzefa Dungrawala, Hui Hua, Jill Wright, Lesley Abraham, Thivakorn Kasemsri, Anthony Mcdowell, Jessica Stilwell, Brandt L. Schneider

Molecular Biosciences Faculty Publications

Cell size homeostasis is a conserved attribute in many eukaryotic species involving a tight regulation between the processes of growth and proliferation. In budding yeast S. cerevisiae, growth to a “critical cell size” must be achieved before a cell can progress past START and commit to cell division. Numerous studies have shown that progression past START is actively regulated by cell size control genes, many of which have implications in cell cycle control and cancer. Two initial screens identified genes that strongly modulate cell size in yeast. Since a second generation yeast gene knockout collection has been generated, we screened …

Using Comparative Genomics For Inquiry-Based Learning To Dissect Virulence Of Escherichia Coli O157:H7 And Yersinia Pestis, David Baumler, Lois Banta, Kai Hung, Jodi Schwarz, Eric Cabot, Jeremy Glasner, Nicole Perna

Faculty Research & Creative Activity

Genomics and bioinformatics are topics of increasing interest in undergraduate biological science curricula. Many existing exercises focus on gene annotation and analysis of a single genome. In this paper, we present two educational modules designed to enable students to learn and apply fundamental concepts in comparative genomics using examples related to bacterial pathogenesis. Students first examine alignments of genomes of Escherichia coli O157:H7 strains isolated from three food-poisoning outbreaks using the multiple-genome alignment tool Mauve. Students investigate conservation of virulence factors using the Mauve viewer and by browsing annotations available at the A Systematic Annotation Package for Community Analysis of …

A Proposal To Test The Effects Of Factor Ecat1 On Pluripotency, From Reprogramming To Differentiation Of Human Somatic Cells, Vritti R. Goel

CMC Senior Theses

The field of stem cell research has been growing more because of the interest in using stem cells to cure diseases and heal injuries. Human embryonic stem cells, because of the controversy surrounding them—and subsequently the difficulties in acquiring samples of the existing aging cell lines—can only be used in limited capacities. While the development of induced pluripotent stem cells in the last decade has allowed the field to progress closer to medical treatments, the low efficiency of reprogramming a somatic cell to a pluripotent state, and the vast molecular and genomic differences between human embryonic stem cells and human …

Inefficient Replication Reduces Reca-Mediated Repair Of Uvdamaged Plasmids Introduced Into Competent Escherichia Coli, Harout Arthur Jeiranian, Charmain T. Courcelle, Justin Courcelle

Biology Faculty Publications and Presentations

Transformation of Escherichia coli with purified plasmids containing DNA damage is frequently used as a tool to characterize repair pathways that operate on chromosomes. In this study, we used an assay that allowed us to quantify plasmid survival and to compare how efficiently various repair pathways operate on plasmid DNA introduced into cells relative to their efficiency on chromosomal DNA. We observed distinct differences between the mechanisms operating on the transforming plasmid DNA and the chromosome. An average of one UV-induced lesion was sufficient to inactivate ColE1-based plasmids introduced into nucleotide excision repair mutants, suggesting an essential role for repair …

Uvrd Participation In Nucleotide Excision Repair Is Required For The Recovery Of Dna Synthesis Following Uv-Induced Damage In Escherichia Coli, Kelley Nicole Newton, Charmain T. Courcelle, Justin Courcelle

Biology Faculty Publications and Presentations

UvrD is a DNA helicase that participates in nucleotide excision repair and several replication-associated processes, including methyl-directed mismatch repair and recombination. UvrD is capable of displacing oligonucleotides from synthetic forked DNA structures in vitro and is essential for viability in the absence of Rep, a helicase associated with processing replication forks. These observations have led others to propose that UvrD may promote fork regression and facilitate resetting of the replication fork following arrest. However, the molecular activity of UvrD at replication forks in vivo has not been directly examined. In this study, we characterized the role UvrD has in processing …

Electric Field Exposure Triggers And Guides Formation Of Pseudopod-Like Blebs In U937 Monocytes, Mikhail A. Rassokhin, Andrei G. Pakhomov

Bioelectrics Publications

We describe a new phenomenon of anodotropic pseudopod-like blebbing in U937 cells stimulated by nanosecond pulsed electric field (nsPEF). In contrast to "regular," round-shaped blebs, which are often seen in response to cell damage, pseudopod-like blebs (PLBs) formed as longitudinal membrane protrusions toward anode. PLB length could exceed the cell diameter in 2 min of exposure to 60-ns, 10-kV/cm pulses delivered at 10-20 Hz. Both PLBs and round-shaped nsPEF-induced blebs could be efficiently inhibited by partial isosmotic replacement of bath NaCl for a larger solute (sucrose), thereby pointing to the colloid-osmotic water uptake as the principal driving force for bleb …

Oxidative Effects Of Nanosecond Pulsed Electric Field Exposure In Cells And Cell-Free Media, Olga N. Pakhomova, Vera A. Khorokhorina, Angela M. Bowman, Raminta Rodaitė-Riševičienė, Gintautas Saulis, Shu Xiao, Andrei G. Pakhomov

Bioelectrics Publications

Nanosecond pulsed electric field (nsPEF) is a novel modality for permeabilization of membranous structures and intracellular delivery of xenobiotics. We hypothesized that oxidative effects of nsPEF could be a separate primary mechanism responsible for bioeffects. ROS production in cultured cells and media exposed to 300-ns PEF (1–13 kV/cm) was assessed by oxidation of 2′, 7′-dichlorodihydrofluoresein (H₂DCF), dihidroethidium (DHE), or Amplex Red. When a suspension of H₂DCF-loaded cells was subjected to nsPEF, the yield of fluorescent 2′,7′dichlorofluorescein (DCF) increased proportionally to the pulse number and cell density. DCF emission increased with time after exposure in nsPEF-sensitive Jurkat …

The Role Of Nucleotide Excision Repair In Restoring Replication Following Uv-Induced Damage In Escherichia Coli, Kelley Nicole Newton

Dissertations and Theses

Following low levels of UV exposure, Escherichia coli cells deficient in nucleotide excision repair recover and synthesize DNA at near wild type levels, an observation that formed the basis of the post replication recombination repair model. In this study, we characterized the DNA synthesis that occurs following UV-irradiation in the absence of nucleotide excision repair and show that although this synthesis resumes at near wild type levels, it is coincident with a high degree of cell death. We confirm that the replication occurring under these conditions involves extensive levels of strand exchange. However, cells undergoing this form of replication accumulate …

The Effect Of Exercise On Endothelin And Endothelin Receptor Levels In Shr And Wky Male And Female Rats, Lacey Stiller

All Graduate Theses, Dissertations, and Other Capstone Projects

The role of exercise as a means to modulate renal function in hypertension is unclear. However, prior studies in the laboratory of Dr. Penny Knoblich indicate that exercised female spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKY) rats excrete significantly more sodium in response to a rise in blood pressure relative to exercised male and sedentary female SHR and WKY rats. The purpose of this study was to evaluate the effects of exercise on endothelin and endothelin receptor levels in the urine and kidneys of male and female SHR and WKY rats, to elucidate potential mechanisms to explain an increase …