Cell Biology Commons^™

Uncovering Genes Involved In Non-Npc-Associated Dbp5 Function, Jonah Hooks, Rebecca Adams

[Archive] Belmont University Research Symposium (BURS)

During an mRNA’s lifecycle, RNA-binding proteins (RBP) are added and removed in order to facilitate export from the nucleus to the cytoplasm through the nuclear pore complex (NPC). During the RNA export process, a class of proteins termed Dead-box proteins (Dbps) are strategically located at the cytoplasmic face of the NPC to remove mRNPs from the mRNA-protein complex, providing one way directionality for export in the process termed mRNA-protein (mRNP) remodeling. Specifically, Mex67 is an RBP which ferries the transcript through the nuclear pore complex and is removed by Dbp5, which is located at the cytoplasmic …

Transcriptional Silencing Of Cdk18 And Its Role In Lung Carcinogenesis Of Brg1-Mutant Lung Cancers, Loryn M. Phillips

Biology ETDs

BRG1 is mutated in 10% of lung cancers, making this mutation clinically relevant. The downstream effects of BRG1 included significantly affecting the cell cycle control and chromosomal replication pathway. CDK18, a cyclin-dependent kinase, was determined to be the gene with significantly decreased expression (p < 0.0001) in the cell cycle control and chromosomal replication pathway. CDK18 is active during the S-phase of the cell cycle and required for genomic stability. Studies were conducted to determine the epigenetic mechanisms that contributed to the repression of CDK18. Histone methylation contributes to the repression of CDK18, and histone deacetylation globally regulates expression of CDK18, while cytosine methylation was found to not contribute to CDK18 expression. Studies were performed to elucidate CDK18 functional role lung carcinogenesis and the genome-wide impact of CDK18 repression. Repression of CDK18 affects cell migration, proliferation, cell-cell signaling, and anchorage-independent growth that contribute to cancer initiation and progression.

Influence Of Metabolic Interventions On Animal Aging And Lifespan, Bhaswati Ghosh

LSU Doctoral Dissertations

Aging is associated with metabolic rewiring. Most lifespan-extending longevity interventions target metabolic pathways. Genetic or pharmacological metabolic approaches that mediate longer lifespan and healthspan, are often linked to detrimental effects on human health. Here, I show that supplementation of botanical extracts from Artemisia scoparia (SCO), dramatically increases animal lifespan. Mechanistically, this lifespan extension is dependent on AMPK-DAF-16 signaling via inhibition of the insulin pathway. In SCO-fed worms, longer lifespan was accompanied by higher fat storage and improved resiliency to age-related physiological stress. Notably, DAF-16, the master regulator of longevity, activated the fatty acid desaturation processes, which promoted the accumulation of …

Novel Mechanisms Of Systemic Sclerosis-Associated Lung Fibrosis, Joe E. Mouawad

MUSC Theses and Dissertations

Systemic sclerosis (SSc), also known as scleroderma, is an autoimmune disorder that affects the connective tissues and has the highest mortality rate among the rheumatic diseases. One of the hallmarks of SSc is fibrosis, which may develop systemically, affecting the skin and virtually any visceral organ in the body. Fibrosis of the lungs leads to interstitial lung disease (ILD), which is currently the leading cause of death in SSc. The identification of effective treatments to stop or reverse lung fibrosis has been the main challenge in reducing SSc mortality and improving patient outcomes and quality of life. Currently, only two …

Svip Dependent Tubular Lysosomal Restoration: A New Direction In Vcp Diseases, Ankita Basu

LSU Doctoral Dissertations

Multisystem Proteinopathy-1 (MSP-1) is a rare, autosomal dominant, degenerative disease resulting from single amino acid mis-sense mutations in the AAA+ ATPase, Valosin containing protein (VCP). Patients with VCP mutations vary widely in their pathology and clinical penetrance, making it difficult to devise effective treatment strategies. To investigate the pathology of VCP- related disease, we engineered CRISPR knock-in Drosophila models for nine MSP-1 associated VCP mutations. These mutant animals mimic human MSP-1 disease phenotypes, including progressive mobility decline and accumulation of protein aggregates, making them excellent models to study the pathology of VCP associated mutations and test potential treatment strategies. At …

The Effects Of Specialized Pro-Resolving Mediator Lipoxin A4 On Pseudomonas Aeruginosa Biofilms And Interactions With Monocytes, Julianne M. Thornton

Graduate School of Biomedical Sciences Theses and Dissertations

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen known as a major cause of hospital-acquired secondary infections, commonly causing chronic respiratory infections in immunocompromised individuals, especially those with cystic fibrosis, and often found in wound infections. P. aeruginosa uses the quorum sensing pathway to readily form protective biofilms, which reduce the efficacy of antibiotics and access by host immune cells to eradicate the pathogen. Specialized pro-resolving mediators (SPMs) are lipids endogenously produced by the host immune response to infection to aid in infection resolution. One SPM, Lipoxin A4 (LxA4), has been shown to be a robust quorum sensing inhibitor.

The …

Modeling The Tripartite Role Of Cyclin C In Cellular Stress Response Coordination, Steven J. Doyle

Graduate School of Biomedical Sciences Theses and Dissertations

For normal cellular function, exogenous signals must be interpreted and careful coordination must take place to ensure desired fates are achieved. Mitochondria are key regulatory nodes of cellular fate, undergoing fission/fusion cycles depending on the needs of the cell, and help mediate cell death fates. The CKM or Cdk8 kinase module, is composed of cyclin C (CC), Cdk8, Med12/12L, and Med13/13L. The CKM controls RNA polymerase II, acting as a regulator of stress-response and growth-control genes. Following stress, CC translocates to the mitochondria and interacts with both fission and iRCD apoptotic mediators. We hypothesize that CC represents a key mediator, …

Investigating The Antibacterial And Immunomodulatory Properties Of Lactobacillus Acidophilus Postbiotics, Rachael M. Wilson

Graduate School of Biomedical Sciences Theses and Dissertations

Probiotics are nonpathogenic microorganisms that have been extensively studied for their ability to prevent various infectious, gastrointestinal, and autoimmune diseases. The mechanisms underlying these probiotic effects have not been elucidated. However, we and other researchers have evidence suggesting that probiotic bacteria secrete metabolites that are antimicrobial and anti-inflammatory. As such, we developed a methodology to collect the secreted metabolites from a probiotic bacterium, Lactobacillus acidophilus, and tested this cell free filtrate (CFF) both in vitro and in vivo. Using this CFF, we have demonstrated that L. acidophilus secretes a molecule(s) that has specific bactericidal activity against the opportunistic pathogen, Pseudomonas …

Med13 Degradation Defines A New Receptor-Mediated Autophagy Pathway Activated By Nutrient Deprivation, Sara E. Hanley

Graduate School of Biomedical Sciences Theses and Dissertations

Cells are exposed to an enormous amount of diverse extracellular cues but have a limited arsenal of weapons for protecting and maintaining homeostasis. To overcome these restrictions, nature has engineered proteins that have multiple functions. The pleiotropy of using one protein to carry out a variety of functions allows cells to rapidly execute tailored responses to a diverse set of signals. The Cdk8 kinase module (CKM) is a conserved detachable unit of the Mediator complex predominantly known for its role in transcriptional regulation. The CKM is composed of four proteins, the scaffolding proteins Med13 and Med12, as well as the …

Immunohistochemical Investigation Of Wwp1 Expression During Embryonic Heart Development And Its Implications For Cardiac Aging, Savannah L. Bowers

Senior Theses

Cardiovascular disease is the leading cause of mortality globally, with the aging population being most vulnerable. Cardiomyocytes and cardiac fibroblasts mediate pathophysiological changes of cardiac aging including interstitial fibrosis, left ventricular hypertrophy, lethal arrhythmias, and eventual culmination in heart failure. Interestingly, subclinical congenital heart disease and hypertrophic cardiomyopathy, originating in embryonic development, induce accelerated cardiac aging. The diverse developmental origins of cardiac fibroblasts suggest that perturbations in gene expression within this heterogeneous cell population during embryonic heart development have significant consequences for cardiac aging. Previous studies implicate the E3 ubiquitin ligase WWP1, a post-translational regulatory protein, in accelerated cardiac aging. …

Characterization And Genomic Analysis Of Two Escherichia Coli O157:H7 Bacteriophages Isolated From Pigeons, Mohamad I. Alolama

Dissertations

Enterohemorrhagic Escherichia coli, also known as EHEC, is a subset of Shiga toxin-producing E. coli (STEC), and it has recently been identified as one of the principal foodborne pathogens. E. coli O157:H7 is the most important serotype of STEC for its role in causing foodborne illnesses. E. coli O157:H7 could cause various gastroenteritis symptoms such as diarrhea, hemolytic uremic syndrome, hemorrhagic colitis, and thrombotic thrombocytopenic purpura and may cause death. Elimination of E. coli O157:H7 during food processing and storage is a possible solution. Bacteriophages have a significant impact on bacterial populations in nature due to their ability to …

Mirna-489 Induces Immunogenic Cell Death In Triple Negative Breast Cancer Cells, Ryan P. Titus

Senior Theses

It has been well established that microRNAs (miRNAs) play an important role in the regulation of gene expression and consequently promoting or downregulating molecular pathways. When dysregulated, miRNAs have been found to serve as important biomarkers for cancer diagnosis and influence tumor initiation and progression. It has been previously established that miRNA-489 is a tumor suppressor microRNA, and it directly targets cell proliferative pathways like the HER2-SHP2-MAPK pathway. In this study, we focus on the role of miRNA-489, in the induction of immunogenic cell death (ICD) in triple-negative breast cancer cell lines. We first examined the effects of miRNA-489 on …

Mc-02 Increased Wound Healing In P-Glycoprotein Deficient Intestinal Cells, Madison T. Mcneill, Scott Tanner

SC Upstate Research Symposium

Inflammatory bowel disease (IBD) is an autoimmune disease of unknown cause and includes conditions such as Crohn’s disease and ulcerative colitis. With no cure and only palliative therapies available, many patients with these conditions struggle with diarrhea, abdominal pain, and other chronic symptoms. This study is interested in investigating the multidrug resistance gene (MDR) which encodes the small molecule pump P-glycoprotein (P-gp).

This gene is responsible for regulating drug absorption and accumulation in various parts of the body such as the intestines which is of particular interest to this study. Polymorphisms of the MDR1 gene (encoding p-glycoprotein) have consequently been …

The Prognostic Value Of Baseline Clinical And Radiologic Imaging Features In Patients With Unresectable Hepatocellular Carcinoma Treated With Atezolizumab Plus Bevacizumab, Mikhail Bogdanov

Faculty, Staff and Student Publications

Membrane asymmetry means that the two sides of membrane are structurally, physically and functionally different. Membrane asymmetry is largely related to the lipid sidedness and particularly to compositional (lipid head and acyl group) and physical (lipid packing order, charge, hydration and H-bonding interactions) differences in the inner and outer leaflets of lipid bilayer. Chemically, structurally and conformationally different non-covalent bound lipid molecules are physically fluid and deformable and enable to interact dynamically to form transient arrangements with asymmetry both perpendicular and parallel to the plane of the lipid bilayer. Although biological membranes are almost universally asymmetric however the asymmetry is …

Renovating A Double Fence With Or Without Notifying The Next Door And Across The Street Neighbors: Why The Biogenic Cytoplasmic Membrane Of Gram-Negative Bacteria Display Asymmetry?, Mikhail Bogdanov

Faculty, Staff and Student Publications

The complex two-membrane organization of the envelope of Gram-negative bacteria imposes an unique biosynthetic and topological constraints that can affect translocation of lipids and proteins synthesized on the cytoplasm facing leaflet of the cytoplasmic (inner) membrane (IM), across the IM and between the IM and outer membrane (OM). Balanced growth of two membranes and continuous loss of phospholipids in the periplasmic leaflet of the IM as metabolic precursors for envelope components and for translocation to the OM requires a constant supply of phospholipids in the IM cytosolic leaflet. At present we have no explanation as to why the biogenic E. …

Surveillance And Stewardship: Where Infection Prevention And Antimicrobial Stewardship Intersect, Fred C. Tenover, Debra A. Goff

Biology Faculty Publications

Colonization with multidrug-resistant organisms (MDROs) is a risk factor for subsequent infection. Surveillance for MDROs, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Enterobacterales, and carbapenemase-producing organisms, is commonly conducted in hospitals to prevent spread of MDROs, in part to reduce the potential for additional infections. Although colonization is a risk factor for infection, data on colonization with various MDROs are often not considered when selecting anti-infective therapy. There are conflicting data on the strength of the positive and negative predictive values of the colonization test results to guide therapeutic strategies. Defining therapeutic strategies for patients with complicated or …

Crosstalk Between The Extracellular Matrix And The Cell- Cell Junction - Associated Rnai Machinery Regulates Colon Cancer Cell Behavior, Amanda Daulagala

MUSC Theses and Dissertations

Colon cancer is the third most common and second deadliest type of cancer. Colon cancer is broadly characterized by compromised epithelial integrity and by aberrant extracellular matrix (ECM) remodeling. However, a potential mechanistic connection between epithelial integrity and ECM remodeling that could be contributing to the disease progression, has not been explored yet. The Adherens Junction (AJ) is a cell-cell adhesion complex composed of cadherin and catenin family proteins and essential for establishing and maintaining epithelial tissue integrity. Our previous work revealed that PLEKHA7, an E-cadherin-p120 catenin partner, recruits the microprocessor and the RNA-induced silencing complex (RISC), key components of …

Effects On Primary Endothelial Cells When Exposed To Polyethylene Terephthalate Nanoplastic, David Guzman

Seaver College Research And Scholarly Achievement Symposium

As the use of plastics becomes more predominant in our environment, the interactions between nanoplastics and the human body have increased dramatically. One of the most common and prevalent plastics is polyethylene, and more specifically polyethylene terephthalate (PET). Tissue exposure to nanoplastics occurs through surface contact upon ingestion or inhalation where nanoplastics can pass readily through the epithelial layer. Directly beneath gut and lung epithelia is the endothelial layer of capillaries. Very little is known about the interactions between polyethylene and human cells, with no information currently available on its effects with the endothelial layer. Our previous research showed that …

Amphiphilic Cell-Penetrating Peptides Containing Arginine And Hydrophobic Residues As Protein Delivery Agents, Jonathan Moreno, Khalid Zoghebi, David Salehi, Lois Kim, Sorour Khayyatnejad Shoushtari, Rakesh K. Tiwari, Keykavous Parang

Pharmacy Faculty Articles and Research

The entry of proteins through the cell membrane is challenging, thus limiting their use as potential therapeutics. Seven cell-penetrating peptides, designed in our laboratory, were evaluated for the delivery of proteins. Fmoc solid-phase peptide synthesis was utilized for the synthesis of seven cyclic or hybrid cyclic–linear amphiphilic peptides composed of hydrophobic (tryptophan (W) or 3,3-diphenylalanine (Dip) and positively-charged arginine (R) residues, such as [WR]4, [WR]9, [WWRR]4, [WWRR]5, [(RW)5K](RW)5, [R5K]W7, and [DipR]5. Confocal microscopy was used to screen the peptides as a protein delivery system of model cargo proteins, green and red fluorescein proteins (GFP and RFP). Based on the confocal …

Epidermal Threads Reveal The Origin Of Hagfish Slime, Yu Zeng, David C. Plachetzki, Kristen Nieders, Hannah Campbell, Marissa Cartee, M. Sabrina Pankey, Kennedy Guillen, Douglas Fudge

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

When attacked, hagfishes produce a soft, fibrous defensive slime within a fraction of a second by ejecting mucus and threads into seawater. The rapid setup and remarkable expansion of the slime make it a highly effective and unique form of defense. How this biomaterial evolved is unknown, although circumstantial evidence points to the epidermis as the origin of the thread- and mucus-producing cells in the slime glands. Here, we describe large intracellular threads within a putatively homologous cell type from hagfish epidermis. These epidermal threads averaged ~2 mm in length and ~0.5 μm in diameter. The entire hagfish body is …