Cell Biology Commons^™

Using Mouse Models To Define How The P53 R72p Polymorphism Impacts The Adverse Effects Of Doxorubicin And Ionizing Radiation, Emily Dominguez

Dissertations and Theses (Open Access)

The single nucleotide polymorphism (SNP) at codon 72 of the tumor suppressor gene p53 codes for either an arginine (R) or proline (P) (p53 R72P). This SNP may impact how cells respond to genotoxic insult. Studies in cell culture and in tissues from mouse models of the SNP indicate that, in response to gentoxic treatment, the two variants may differentially induce apoptosis and expression of p53 target genes. In epidemiological studies, the P variant is associated with decreased cancer survival and increased risk of side-effects from genotoxic cancer treatment. Genotoxic therapy is still the mainstay of cancer treatment, and doxorubicin …

Characterization Of Vesicular Monoamine Transporter 2 And Its Role In Parkinson's Disease Pathogenesis Using Drosophila, Antonio Joel Tito Jr., Sheng Zhang

Dissertations and Theses (Open Access)

Parkinson’s disease (PD) is a progressive neurodegenerative disorder caused by the selective loss of the dopaminergic neurons in the Substantia nigra pars compacta region of the brain. PD is also the most common neurodegenerative disorder and the second most common movement disorder. PD patients exhibit the cardinal symptoms, including tremor of the extremities, rigidity, slowness of movement, and postural instability, after 70-80% of DA neurons degenerate. It is, therefore, imperative to elucidate the underlying mechanisms involved in the selective degeneration of DA neurons. Although increasing numbers of PD genes have been identified, why these largely widely expressed genes induce …

Microenvironment-Induced Pten Loss By Exosomal Microrna Primes Brain Metastasis Outgrowth, Lin Zhang

Dissertations and Theses (Open Access)

Development of life-threatening cancer metastases at distant organs requires disseminated tumor cells’ adaptation to and co-evolution with the drastically different microenvironments of metastatic sites. Cancer cells of common origin manifest distinct gene expression patterns after metastasizing to different organs. Clearly, the dynamic interplay between metastatic tumor cells and extrinsic signals at individual metastatic organ sites critically impacts the subsequent metastatic outgrowth. Yet, it is unclear when and how disseminated tumor cells acquire the essential traits from the microenvironment of metastatic organs that prime their subsequent outgrowth. Here we show that primary tumor cells with normal expression of PTEN, an important …

Effect Of Oxygen-Limiting Tidal Conditions On Muscle Metabolism And Structure In The Giant Acorn Barnacle, Balanus Nubilus, Katie O. Grady

Master's Theses

Crustacean muscle fibers are some of the largest cells in the animal kingdom, with fiber diameters in the giant acorn barnacle (Balanus nubilus) exceeding 3 mm. Sessile animals with extreme muscle sizes and that live in the hypoxia-inducing intertidal zone – like B. nubilus – represent ideal models for probing the effects of oxygen limitation on muscle cells. We investigated changes in metabolism and structure of B. nubilus muscle in response to: normoxic immersion, anoxic immersion, or air emersion, for acute (6h) or chronic (6h exposures twice daily for 2wks) time periods. Following exposure, we immediately measured hemolymph …

Influence Of Ph And Acidic Side Chain Charges On The Behavior Of Designed Model Peptides In Lipid Bilayer Membranes, Venkatesan Rajagopalan

Graduate Theses and Dissertations

The molecular properties of transmembrane proteins and their interactions with lipids regulate biological function. Of particular interest are interfacial aromatic residues and charged residues in the core helix whose functions range from stabilizing the native structure to regulating ion channels. This dissertation addresses the pH dependence and influence of potentially negatively charged tyrosine, glutamic acid or aspartic acid side chains. We have employed GWALP23 (acetyl-GGALW5LALALALALALALW19LAGA-amide) as favorable host peptide framework. We have substituted W5 with Tyr (Y5GWALP23) and Leu residues with Glu (L12E, L14E or L16E) or Asp (L14D or L16D), and have incorporated specific 2H-labeled alanine residues within the …

Dopamine Effects Of Stimulant And Non-Stimulant Drugs Used In The Treatment Of Attention Deficit Hyperactivity Disorder, Preeti Chalwadi

Theses and Dissertations

Attention deficit hyperactivity disorder (ADHD) is thought to be associated with dysfunction of ascending catecholamine neuronal systems, particularly dopamine (DA) and norepinephrine (NE). Dysfunction of these catecholamine neurons innervating the prefrontal cortex is hypothesized to underlie impaired executive functions. Dysfunction of the DA neurons innervating the striatum is additionally hypothesized to underlie deficits in motivation and reinforcement learning. However, mechanisms of action of therapeutic drugs used for treating ADHD have mainly focused on catecholamines in the prefrontal cortex and have not adequately addressed the role played by DA signaling in the striatum. Stimulants such as Adderall® and Ritalin® are chemically …

Mxa Is A Novel Regulator Of Endosome-Associated Transcriptional Signaling By Bone Morphogenetic Proteins 4 And 9 (Bmp4 And Bmp9), Huijuan Yuan, Pravin B. Sehgal

NYMC Faculty Publications

There is confusion about the role that IFN-α plays in the pathogenesis of pulmonary arterial hypertension (PAH) with different investigators reporting a causative or a protective role. There is now clear evidence in PAH pathogenesis for the involvement of BMP4 and BMP9 signaling, and its disruption by mutations in BMPR2. In the present study, we investigated MxA, an IFN-α-inducible cytoplasmic dynamin-family GTPase for effects on BMP4/9 signaling, including in the presence of PAH-disease-associated mutants of BMPR2. In human pulmonary arterial endothelial cells (HPAECs), IFN-α-induced endogenous as well as exogenously expressed MxA was associated with endosomes that aligned alongside microtubules and …

Vdr-Ripk1 Interaction And Its Implications In Cell Death And Cancer Intervention, Waise Quarni

USF Tampa Graduate Theses and Dissertations

Receptor interacting protein kinase 1 (RIPK1) is an enzyme acting downstream of tumor necrosis factor alpha to control cell survival and death. RIPK1 expression has been reported to cause drug resistance in cancer cells; but so far, no published studies have investigated the role of RIPK1 in vitamin D action. In the present study, we investigated whether RIPK1 played any role in 1,25-dihydroxyvitamin D3 (1,25D3)-induced growth suppression. In our studies, RIPK1 decreased the transcriptional activity of vitamin D receptor (VDR) in luciferase reporter assays independently of its kinase activity, suggesting a negative role of RIPK1 in 1,25D3 action. RIPK1 also …

Pt-Mal-Lhrh Mediates Breast Cancer Cell Cytotoxicity Through Increased Apoptosis, Kendall E. Collins

Posters-at-the-Capitol

In the United States one in eight women will be afflicted with breast cancer. It is estimated that in 2016 there will be approximately 246,600 new invasive breast cancer cases and 61,000 new non-invasive cases. Triple negative breast cancers account for 15% of all breast cancers and are significantly more aggressive than other subtypes. Treatment options for triple negative breast cancer are limited due to the cancers not expressing the estrogen, progestogen, or herceptin receptors making them unresponsive to hormonal therapy. Our recent work centers around developing a novel chemotherapeutic agent that will direct therapy selectively to triple negative (4T1) …

Localization And Distribution Of Primary Cilia In The Adult Mouse Heart, Ali Zarban, Hannah C. Saternos, Andrea L. Kalinoski, Lijun Liu, Surya M. Nauli, Wissam A. Aboualaiwi

Pharmacy Faculty Articles and Research

Although primary cilia have been shown to play crucial roles in the development of embryonic mouse heart, their presence and function in adult mouse heart remains controversial. In this study, the presence of primary cilia in adult mouse heart was investigated. The presence of primary cilia was initially demonstrated in the surface of cardiac cells of mouse hearts from both young and adult mice by immunostaining with acetylated α-tubulin, a ciliary structural marker. The presence of cardiac primary cilia in 1-, 3-, 6- and 12-month old mice was further confirmed by staining heart tissues with an antibody against pericentrin, a …

Effects Of Anchor Structure And Glycosylation Of Fcî³ Receptor Iii On Ligand Binding Affinity, Ning Jiang, Wei Chen, Prithiviraj Jothikumar, Jaina M. Patel, Rangaiah Shashidharamurthy, Periasamy Selvaraj, Cheng Zhu

PCOM Scholarly Works

Isoforms of the Fcγ receptor III (FcγRIII or CD16) are cell surface receptors for the Fc portion of IgG and important regulators of humoral immune responses. Different ligand binding kinetics of FcγRIII isoforms are obtained in three dimensions by surface plasmon resonance and in two dimensions by a micropipette adhesion frequency assay. We show that the anchor structure of CD16 isoforms isolated from the cell membrane affects their binding affinities in a ligand-specific manner. Changing the receptor anchor structure from full to partial to none decreases the ligand binding affinity for human IgG1 (hIgG1) but increases it for murine IgG2a …

Understanding The Differences Between Neuronal Calcium Sensor Proteins: A Comparison Of Neurocalcin Delta And Hippocalcin, Jeffrey M. Viviano

Graduate School of Biomedical Sciences Theses and Dissertations

Many neuronal functions, including learning and memory are driven by changes in intracellular Ca2+concentrations. The Neuronal Calcium Sensor (NCS) family of proteins is responsible for mediating the response to calcium. They are typically comprised of 4 EF hands; of which EF 2, 3, and 4 bind calcium.

Hypothesis: NCS proteins carry out unique, non-overlapping functions, and that specific characteristics of the family can be mapped to precise regions of the proteins.

Results: The effect on the following properties were investigated primarily on two highly similar NCS proteins, Neurocalcin Delta (NCALD) and Hippocalcin (HPCA): (1) Response to calcium was determined through …

Leukocyte Telomere Length In Relation To 17 Biomarkers Of Cardiovascular Disease Risk: A Cross-Sectional Study Of Us Adults, David Rehkopf, Belinda L. Needham, Jue Lin, Elizabeth Blackburn, Ami R. Zota, Janet Wojcicki, Elissa Epel

Environmental and Occupational Health Faculty Publications

Background

Leukocyte telomere length (LTL) is a putative biological marker of immune system age, and there are demonstrated associations between LTL and cardiovascular disease. This may be due in part to the relationship of LTL with other biomarkers associated with cardiovascular disease risk. However, the strength of associations between LTL and adiposity, metabolic, proinflammatory, and cardiovascular biomarkers has not been systematically evaluated in a United States nationally representative population.

Methods and Findings

We examined associations between LTL and 17 cardiovascular biomarkers, including lipoproteins, blood sugar, circulatory pressure, proinflammatory markers, kidney function, and adiposity measures, in adults ages 20 to 84 …

Pleckstrin Homology (Ph) Domain Leucine-Rich Repeat Protein Phosphatase Controls Cell Polarity By Negatively Regulating The Activity Of Atypical Protein Kinase C, Xiaopeng Xiong, Xin Li, Yang-An Wen, Tianyan Gao

Markey Cancer Center Faculty Publications

The proper establishment of epithelial polarity allows cells to sense and respond to signals that arise from the microenvironment in a spatiotemporally controlled manner. Atypical PKCs (aPKCs) are implicated as key regulators of epithelial polarity. However, the molecular mechanism underlying the negative regulation of aPKCs remains largely unknown. In this study, we demonstrated that PH domain leucine-rich repeat protein phosphatase (PHLPP), a novel family of Ser/Thr protein phosphatases, plays an important role in regulating epithelial polarity by controlling the phosphorylation of both aPKC isoforms. Altered expression of PHLPP1 or PHLPP2 disrupted polarization of Caco2 cells grown in 3D cell cultures …

Oxidative Stress In Oocytes During Midprophase Induces Premature Loss Of Cohesion And Chromosome Segregation Errors, Adrienne T. Perkins, Thomas M. Das, Lauren C. Panzera, Sharon E. Bickel

Dartmouth Scholarship

In humans, errors in meiotic chromosome segregation that produce aneuploid gametes increase dramatically as women age, a phenomenon termed the "maternal age effect." During meiosis, cohesion between sister chromatids keeps recombinant homologs physically attached and premature loss of cohesion can lead to missegregation of homologs during meiosis I. A growing body of evidence suggests that meiotic cohesion deteriorates as oocytes age and contributes to the maternal age effect. One hallmark of aging cells is an increase in oxidative damage caused by reactive oxygen species (ROS). Therefore, increased oxidative damage in older oocytes may be one of the factors that leads …

Sulfatase 2 Facilitates Lymphangiogenesis In Breast Cancer By Regulating Vegf-D., Chenfang Zhu, Xiaoliang Qi, Xin Zhou, Xin Nie, Yan Gu

Surgery Faculty Publications

In our previous studies, sulfatase 2 (Sulf2) was found to upregulate vascular endothelial growth factor-D (VEGF-D) expression in breast cancer. As VEGF-D plays an important role in lymphangiogenesis, we hypothesized that Sulf2 facilitates lymphangiogenesis in breast cancer by regulating VEGF-D. To evaluate the functions of Sulf2 on lymphangiogenesis in breast cancer, proliferation, apoptosis, cell cycle, cell mobility and tube-formation of lymphatic endothelial cells (LECs) were measured in vitro. Lymphangiogenesis in nude mouse ears and breast cancer xenografts were examined in vivo. Furthermore, the expression levels of related signaling pathway genes were screened and verified in LECs. We found that Sulf2 …

Replication-Transciption Switch In Human Mitochondria, Karen Agaronyan

Graduate School of Biomedical Sciences Theses and Dissertations

Coordinated replication and expression of mitochondrial genome is critical for metabolically active cells during various stages of development. However, it is not known whether replication and transcription can occur simultaneously without interfering with each other and whether mtDNA copy number can be regulated by the transcription machinery. Human mitochondrial RNA polymerase (mtRNAP) is a central enzyme involved in gene expression in mitochondria. It generates genome-size polycistronic transcripts and also makes replication primers at two origins of replication. MtRNAP is distantly related to phage T7 RNAP. While T7 RNAP is optimized to produce large amounts of transcripts to overcompete the bacterial …

An Arginine Finger Regulates The Sequential Action Of Asymmetrical Hexameric Atpase In The Double-Stranded Dna Translocation Motor, Zhengyi Zhao, Gian Marco De-Donatis, Chad T. Schwartz, Huaming Fang, Jingyuan Li, Peixuan Guo

Pharmaceutical Sciences Faculty Publications

Biological motors are ubiquitous in living systems. Currently, how the motor components coordinate the unidirectional motion is elusive in most cases. Here, we report that the sequential action of the ATPase ring in the DNA packaging motor of bacteriophage ϕ29 is regulated by an arginine finger that extends from one ATPase subunit to the adjacent unit to promote noncovalent dimer formation. Mutation of the arginine finger resulted in the interruption of ATPase oligomerization, ATP binding/hydrolysis, and DNA translocation. Dimer formation reappeared when arginine mutants were mixed with other ATPase subunits that can offer the arginine to promote their interaction. Ultracentrifugation …

Depletion Of The Rna Helicase Skiv2l2 Impedes Mitotic Progression And Histone Mrna Turnover In Murine Cell Lines, Alexis Marie Onderak

Dissertations (1934 -)

RNA surveillance via the nuclear exosome requires cofactors such as the helicase SKIV2L2 to process and degrade certain noncoding RNAs. This dissertation aimed to characterize the phenotype associated with RNAi knockdown of SKIV2L2 in two murine cancer cell lines: Neuro2A and P19. Skiv2l2 knockdown in Neuro2A and P19 cells induced changes in gene expression indicative of cell differentiation and reduced cellular proliferation. Analysis of the cell cycle revealed defective progression through mitosis following SKIV2L2 depletion. These results indicate that SKIV2L2 enhances mitotic progression, thereby maintaining cancer cell proliferation and preventing differentiation. Indeed, SKIV2L2 levels were found to be downregulated during …

Molecular Analysis Of Ftsz-Ring Assembly In E. Coli Cytokinesis, Kuo-Hsiang Huang

Dissertations, Theses, and Capstone Projects

An essential first step in bacterial division is the assembly of a cytokinetic ring (Z-ring) formed by the tubulin-like FtsZ at midcell. The highly conserved core domain of FtsZ has been reported to mediate assembly of FtsZ polymers in vivo and in vitro. Species-specific differences in the FtsZ C-terminal domain such as the FtsZ CTV region and interactions with several modulatory proteins such as ZapC and ZapD, restricted to certain bacterial classes, also serve as key determinants of FtsZ protofilament bundling. Here, we characterize (i) the roles of the FtsZ CTV region in mediating both longitudinal and lateral interactions …