Medical Sciences Commons^™

Na/K-Atpase Alphα1 Regulates Adipogenesis Via Its Conserved Caveolin Binding Motif, Minqi Huang

Theses, Dissertations and Capstones

The Na/K-ATPase (NKA) was identified in 1957 by Dr. Jens C. Skou. It belongs to the P-type ATPase family, which can actively transport ions across cell membranes by using the energy from adenosine triphosphate (ATP) hydrolysis. During the second half of the 20th century, the molecular mechanism of the NKA catalytic cycle was clarified, and the isoform diversity of NKA in different species and organs was identified. The active ion transport through NKA generates cell membrane ion gradients and the electric potential. Hence, the enzymatic function of NKA is critical for cell viability as well as multiple physiological processes including …

Potential Counter Regulatory Effects Of A Gut Microbiota Metabolite In Alleviating Down-Regulation Krüppel-Like Factor 4 In Intestinal Inflammation, Ylva Forslund

Theses, Dissertations and Capstones

Inflammatory bowel disease (IBD) is a medical condition characterized by chronic inflammation of the intestinal epithelium. Krüppel-like factor 4 (KLF4), a zinc finger transcription factor, is vital for maintaining intestinal epithelial homeostasis. KLF4 promotes differentiation of goblet cells that generate the protective mucus layer. Reduced goblet cell number and defective mucus layer are associated with IBD. Shortchain fatty acids (SCFA) are known to play an important role in the maintenance of a strong and healthy intestinal epithelial layer and also in goblet cell differentiation. However, whether the positive effects of SCFAs on goblet cells are mediated, at least partly, via …

Targeting Epigenetic Mechanisms In Endometriosis, Sarah Elizabeth Brunty

Theses, Dissertations and Capstones

Endometriosis is a complex and elusive gynecological disease in which the inner lining of the uterus grows in locations outside of the uterus and forms lesions. It is known to affect 1 in 9 women of reproductive age worldwide. Symptoms of endometriosis include severe pain, heavy periods, and infertility. While multiple theories of origin exist, none fully encompass all aspects of the disease, although all theories agree that this is an inflammation-driven disease. Due to this, many researchers are turning towards epigenetics to explain the initiation and progression of endometriosis. However, what is causing these epigenetic changes is still a …

The Epigenetic Effects Of Omega-3 Fatty Acids In Diffuse Large B-Cell Lymphoma, Tanner Jeffrey Bakhshi

Theses, Dissertations and Capstones

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma. It is an aggressive cancer, with 50-70% of patients diagnosed at an advanced stage and 30-50% of patients not cured by chemoimmunotherapy. DLBCL is almost always caused by genetic damage sustained during the germinal center (GC) reaction. The mechanisms that govern the GC reaction bear a striking resemblance to those that drive DLBCL. Genomic studies have shown that some of its most common mutations occur in genes that encode epigenetic modifiers, including the lysine (histone) acetyltransferases CREBBP and p300. These mutations prevent the acetylation of multiple histone residues, …

Regulation Of Na-K-Atpase By Arachidonic Acid Metabolites In Intestinal Epithelial Cells, Niraj Nepa

Theses, Dissertations and Capstones

The integral membrane protein sodium potassium adenosine triphosphate (Na-K-ATPase), has been extensively studied in various animal cell models. Na-K-ATPase is a multifunctional enzyme which plays a significant role in cellular physiology by regulating electrochemical potential, cell volume, pH, cytosolic calcium, and many nutrient and electrolyte transport processes. As such, it has been implicated in the pathogenesis of inflammatory bowel diseases (IBD) and has been shown to play a vital role in the malabsorption of nutrients and electrolytes. In this context, a significant amount of research has been done over the last two decades to understand the mechanisms of alteration of …

Endogenous Antioxidant Overexpression As An Adjuvant To Diet Or Exercise Intervention As Therapy To Counteract Obesity And Beneficially Shift The Gut Microbiome, Deborah Lynn Amos

Theses, Dissertations and Capstones

Oxidative stress plays a key role in metabolic syndrome which includes obesity and cardiometabolic diseases. It is implicated that oxygen-derived free radicals generated during the mitochondrial electron transport chain alter the function of specific biological components, thus activating obesogenic pathways such as glucose and lipid signaling. Research on this topic is of vital importance as obesity is a high-risk factor in the development and progression of severe, debilitating, life-threatening maladies such as cardiometabolic diseases, chronic inflammatory pathologies, and cancer. Furthermore, there is no universal effective therapy to combat the rising rates of obesity with over 1.9 billion (39%) adults classified …

Understanding Pseudomonas Aeruginosa Alginate Regulation And Its Link To Chronic Lung Infections In Cystic Fibrosis Patients, Roy Al Ahmar

Theses, Dissertations and Capstones

Cystic Fibrosis (CF) is a genetic disorder caused by mutations in the gene encoding Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). This disorder results in thick lung secretions which compromise the patient’s immune system. Chronic lung infections with Pseudomonas aeruginosa biofilms is a major factor that contributes to poor outcome for clinical treatment. The overall hypothesis of this dissertation is that small colony variant and pyrimidine biosynthesis are linked with biofilm formation, alginate production is dependent on MucA proteolysis, rifaximin can be repurposed to treat biofilm infection and multiplex PCR can be used to rapidly measure the bacterial cell density in …

Exploring The Regulatory Mechanism Of The Notch Ligand Receptor Jagged1 Via The Aryl Hydrocarbon Receptor In Breast Cancer, Sean Alan Piwarski

Theses, Dissertations and Capstones

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that binds pollutants, therapeutic drugs and endogenous ligands. AHR is of particular interest in cancer and has been shown to play roles in both tumor progression and tumor suppression. As a result, it has received growing attention as a possible chemotherapeutic target. AHR is expressed in all breast cancer subtypes and can promote or inhibit breast cancer depending on the ligand it binds. The Notch signaling pathway is a highly conserved evolutionary pathway that plays extremely vital roles during development by regulating cell fate and differentiation. Notch signaling has increasingly …

Employing The Enzyme Cofactor Function Of Ascorbic Acid To Affect Oncogenic Pathways In Human Melanoma: Modulating Hypoxia Inducible Factor-1Α And Dna Demethylation To Reduce Malignant Potential, Adam Patrick Fischer

Theses, Dissertations and Capstones

Dioxygenase enzymes such as the HIF hydroxylases (PHD1-3, FIH) and the Ten-eleven translocation (TET1-3) enzymes regulate the activity of the hypoxia inducible factor-1_a (HIF1_a) transcription factor and the DNA methylation status of cells, respectively. Aberrant accumulation and activation of HIF-1_a can allow malignant cells to acquire attributes that promote progression, chemotherapy resistance, and survival, while aberrant hypermethylation of gene promoters can silence the expression of tumor suppressor genes essential to preventing tumorigenesis. Inadequate levels of intracellular ascorbic acid (AA), a necessary cofactor for optimal dioxygenase enzyme function, could potentiate these tumorigenic conditions. In fact, plasma levels …

Epigenetic Role Of Ptip In Mouse Spermatogenesis, Chengjing Liu

Theses, Dissertations and Capstones

In mammals, spermatogenesis is a biological process inside the testis to produce spermatozoa from spermatogonia. This process is governed by both genetic and epigenetic mechanisms and thus is a powerful system for epigenetic research. Methylation of histone 3 lysine 4 (H3K4) is an epigenetic mark, which has been found to be dynamically modulated in mouse male germ cells during spermatogenesis. Pax2 Transactivation domain Interaction Protein (PTIP) has been recently identified as part of a H3K4 methyltransferase complex. In this study, I hypothesize that PTIP is an essential epigenetic regulator in mouse spermatogenesis. To test this hypothesis, I first established a …

Cerium Oxide Nanoparticles Attenuate Polymicrobial Sepsis Induced Splenic Damage In Male Sprague Dawley Rats, Venkata Vinay Kumar Bandarupalli

Theses, Dissertations and Capstones

Sepsis is a serious life threatening medical emergency which, if not treated properly, oftentimes results in organ failure and death. Current sepsis treatment protocols are largely centered on the use of antibiotics and supportive care. Recent studies have suggested that antibiotics fail to be effective for sepsis treatment when administered during hypo-dynamic phase of sepsis that is usually characterized by the presence of a cytokine storm. As such, there is an urgent need to develop novel therapeutic drugs that target the inflammatory cytokines that are secreted as a result of increased reactive oxygen species. Cerium oxide nanoparticles (CeO2) have been …

Benzyl Isothiocyanate As An Adjuvant Chemotherapy Option For Head And Neck Squamous Cell Carcinoma, Mary Allison Wolf

Theses, Dissertations and Capstones

Isothiocyanates (ITCs) are natural phytochemicals produced by cruciferous vegetables. Recent evidence supports that, in addition to cancer prevention, ITCs can use various mechanisms to target malignant cells. Current therapies for cancer often provoke detrimental side effects, however clinical evidence supports that ITCs have little to no side effects in patients. Consequently, ITCs may be a promising treatment option for cancer patients, especially patients suffering from head and neck squamous cell carcinoma (HNSCC).

Despite recent improvements in cancer treatment, overall survival of advanced HNSCC has not improved in the past three decades. Metastasis and chemoresistance represent two detrimental events that greatly …

Chmp1 Negatively Regulates Epidermal Growth Factor Signaling In The Drosophila Wing, Meagan Elisabeth Valentine

Theses, Dissertations and Capstones

A critical step in cellular signaling through transmembrane receptors is the down-regulation of activated receptors through the multivesicular body (MVB) pathway to the lysosome. MVB generation is mediated by the highly conserved ESCRT (0, I, II, and III) protein complexes. Though the ESCRT-III complex provides the core function of the ESCRT machinery, it is the least characterized of the ESCRT complexes. The Chmp1 protein is an ESCRT-III component and a putative tumor suppressor that has been linked to pancreatic and renal cancers in humans. However, published data on Chmp1 activity are conflicting and its role during tissue development is not …

Identification And Characterization Of Downstream Effector Protein(S) Regulated By P53 And Prb, Miranda B. Carper

Theses, Dissertations and Capstones

A commonality among cancer types is the high frequency of mutations that inhibit or alter signaling of the p53 and pRb (Retinoblastoma) tumor suppressors. These genes regulate processes vital for cancer suppression such as apoptosis, senescence, and cell cycle arrest among others. Loss of both p53 and pRb promotes processes that support cancer progression and is associated with decreased patient survival and increased rates of tumor reoccurrence. Although data points to the ability of p53 and pRb to collaborate and to inhibit tumorigenesis, it remains unclear how p53 and pRb cooperate toward this task. Using RNA expression profiling, 179 p53 …

Role Of Iron In Ethanol Derived Hepatic Stress, Jesse A. Thornton

Theses, Dissertations and Capstones

Chronic alcohol abuse is the third leading cause of preventable death in the United States. Ethanol metabolism causes liver injury through alterations in hepatic metabolic state, redox status, and acetaldehyde adduct formations. Increased iron absorption is associated with chronic ethanol consumption and may play a role in ethanol induced oxidative stress. We tested the hypothesis that normal labile iron in the liver plays a role in ethanol related pathological stress, using C57/Bl6 mice pair-fed Lieber-DeCarli liquid ethanol diets for 11 and 22 weeks. Normal iron group mice received 55mg/kg iron as ferric citrate, whereas the low iron groups received 5mg/kg. …

Nuclear Receptor Expression And Characterization Of The Major Retinoic Acid Target Gene In Melanoma, Linda L. Eastham

Theses, Dissertations and Capstones

Malignant melanoma is the primary cause of death from all diseases arising from the skin and it is one of the most resistant tumors to standard treatment options. The increasing incidence of melanoma and its poor prognosis makes the understanding of melanoma cell biology very important. Melanoma progression is a complex, multi-step process, and the molecular events leading to melanoma tumor cell proliferation and invasion still need further examination. This study is focused on measuring the expression and activity of two specific genes and their protein counterparts that are altered during melanoma progression. It also examines the mechanism through which …

The Role Of Ptip In Breast Cancer, Lina Niu

Theses, Dissertations and Capstones

In the U.S., breast cancer comprises about 30% of all cancer cases (excluding skin cancer) in women. Such a high incidence makes breast cancer a significant health concern, but our understanding of the molecular and cellular mechanisms of this disease is still limited. Growing evidence suggests that the development of human breast cancer may involve epigenetics, which attributes changes in phenotype to mechanisms other than changes in the DNA sequence itself. Histones as the chief proteins of chromatin work on gene expression, and methylation of histone 3 lysine 4 (H3K4) results in transcriptional activation. Lately, Paired box (Pax) trans-activation domain-interacting …

Pitx2 Is Overexpressed In Follicular Cell-Derived Thyroid Cancer And Promotes Thyroid Cancer Proliferation By Regulating Cell Cycle, Yue Huang

Theses, Dissertations and Capstones

Thyroid cancer is the most prevailing malignancy of the endocrine system. Its incidence is rapidly rising at the second fastest rate of all malignancies in the United States, making it a significant health problem. Although the majority of thyroid cancer is slowly-growing and well-differentiated, available treatment options are very limited, and most of them require complete removal of the thyroid gland and surrounding tissues. Patients who have undergone thyroid removal have to take life-long hormone replacement therapy, which is very inconvenient and costly. Therefore, there is an urgent need to develop new treatments for this disease. As a prerequisite for …

Treatment Strategies In Acute Myelogenous Leukemia : Investigating Hsp90 And P53 As Targets, Jennifer M. Napper

Theses, Dissertations and Capstones

Acute myelogenous leukemia (AML) is the deadliest of the lymphatic and bone marrow cancers. Patients diagnosed with AML have a five year survival rate of 23.4%. AML is characterized by an accumulation of undifferentiated and functionless myeloid precursors in the bone marrow and blood. Heat shock protein 90 (Hsp90) inhibitors, such as 17-AAG, an analog of geldanamycin (GM), are currently undergoing phase I, and II and III clinical trials for various cancers with mixed results. I found distinct responses to 17-AAG treatment among the AML cell lines tested. I also discovered two mutant TP53 alleles in Kasumi-3 cells, an AML …

Genetic And Environmental Factors Suggest That Dietary Fatty Acid Content, Lipid Metabolism, And Bone Properties Are Key Regulators Of Myeloid Progenitor Cell Frequency, Melinda E. Varney

Theses, Dissertations and Capstones

Acute myelogenous leukemia (AML) and its precursors are the result of the dysregulation of hematopoiesis. Hematopoiesis proceeds in a stepwise manner, beginning with hematopoietic stem cells, continuing to develop into various stages of progenitor cells, and finally becoming fully functional blood cells. As this process goes awry, immature, functionless cells of the myeloid lineage proliferate out of control. Discerning how myeloid progenitor frequency is regulated allows for a better understanding of how the process may lose control. Hematopoiesis has been shown to depend on genetic and environmental factors. In this work, I have added to this knowledge base by providing …

The Expression And Function Of Hypoxia Inducible Factor-1Α In Human Melanoma, Sandeep S. Joshi

Theses, Dissertations and Capstones

Hypoxia inducible factor-1α (HIF-1α) protein, a key regulator of oxygen homeostasis, is stabilized under hypoxia and degraded under normal oxygen tension. Here, the human melanoma cells were found to express an elevated amount of HIF-1α mRNA and protein relative to normal human melanocytes under normoxic conditions. The amount of HIF-1α expressed is roughly correlated with the stage of melanoma from which the cell line was established. In addition, a splice variant mRNA of HIF-1α785 is expressed at higher levels than full-length HIF-1α mRNA in the more aggressive melanoma cells. This splice variant lacks part of the oxygen regulation domain. Ectopic …

Efficacy Of Deferasirox In Preventing Complications Of Iron Overload In The Iron Overloaded Gerbil, Rabaa M. Al-Rousan

Theses, Dissertations and Capstones

Iron overload is a significant, world-wide problem that results in several chronic diseases including cardiovascular, hepatic and pancreatic complications.The newly developed, orally effective, iron chelating agent deferasirox is thought to offer tremendous promise as an alternative to deferoxamine. However, the efficacy and safety profile of deferasirox is not yet clear. In the present study, the efficacy of deferasirox in removing iron from target tissues has been examined using the gerbil model of iron overload. Deferasirox administration resulted in a significant reduction of iron from cardiac and hepatic tissue. In addition deferasirox reduced iron induced increase in cardiac and hepatic oxidative …

Identification And Characterization Of Novel Sir3/Mecp2-Chromatin Interactions, Nicholas L. Adkins

Theses, Dissertations and Capstones

The eukaryotic genome is packaged into chromosomes that are made up of a highly organized and heavily regulated structure called chromatin. The proteins involved in the compaction of DNA into this condensed state are mostly understood at the level of the structure of the nucleosome. The higher order arrangement of chromatin and how it effects gene regulation is only partially understood and characterized. The compaction of nucleosomal arrays into 30-nm and higher structures are partially the responsibility of architectural, or structural, chromatin associated proteins. The following dissertation analyzes the individual chromatin contributions of two well studied architectural proteins, the yeast …

The Function And Mechanism Of Chmp1a In Tumor Development, Jing Li

Theses, Dissertations and Capstones

Chmp1A (Chromatin modifying protein 1A/Charged multivesicular protein 1A) is a member of the ESCRT-III (Endosomal Sorting Complex Required for Transport) family, which mediates trafficking via MVB (multivesicular body) formation and sorting. Our studies suggest that Chmp1A is a novel tumor suppressor, especially in the pancreas. Knockdown of Chmp1A resulted in an increase of anchorage-independent growth of HEK 293T cells. Moreover, we showed that Chmp1A depleted HEK 293T cells forms tumor in xenograft mice. Knockdown of Chmp1A in PanC-1 cells promoted cell growth. In contrast, Doxycycline induced over-expression of Chmp1A in pancreatic cancer cells (PanC-1) resulted in cell growth inhibition, tumor …

Manganese Superoxide Dismutase Contributes To Cisplatin-Induced Cytotoxicity Rather Than All-Trans Retinoic Acid-Dependent Chemoresistance, Zina-Ann Cardozo

Theses, Dissertations and Capstones

Neuroblastoma is an extra-cranial solid tumor of the nervous system occurring predominantly in infants and children younger than five years of age. Neuroblastoma presents a challenge to therapy primarily due to a decreased responsiveness to anticancer agents like cisplatin (CDDP), leading to recurrence. Vitamin A and its derivatives, known as retinoids, are preventive against cancer and induce differentiation in some cell lines. Retinoids are now being tested clinically for the treatment of neuroblastoma. One major limitation to retinoid therapy is the development of chemoresistance. In the present study human SK-N-SH neuroblastoma cells pretreated with 10 μM all-trans retinoic acid (ATRA) …

Mlck/Actin Interaction In The Contracting A7r5 Cell And Vascular Smooth Muscle, Sean Eric Thatcher

Theses, Dissertations and Capstones

Myosin light chain kinase (MLCK) is an enzyme that phosphorylates the serine-19 residue on myosin regulatory light chains (MLCs) which serves to activate the Mg2+-ATPase of myosin. This catalytic activity is thought to be the primary role of MLCK; however, it has recently been suggested that MLCK’s actin binding and bundling properties may also be of importance in smooth muscle contraction. In the absence of calcium and calmodulin (CaM), MLCK will bundle actin filaments with its N-terminus. During calcium influx and subsequent CaM activation, MLCK binding to actin decreases resulting in unbundling of actin filaments and allows myosin and actin …

Aging Influences Multiple Indices Of Oxidative Stress In The Heart Of The Fischer 344/Nnia X Brown Norway/Binia Rat, Shinichi Asano

Theses, Dissertations and Capstones

Here we report the influence of aging on multiple markers of oxidativenitrosative stress in the heart of adult (6-month), aged (30-month) and very aged (36- month) Fischer 344/NNiaHSd X Brown Norway/BiNia (F344/NXBN) rats. Compared to 6 month old rat hearts, indices of oxidative (superoxide anion (–O2 ·), 4-hyrdoxy-2- nonenal (4-HNE)) and nitrosative (protein nitrotyrosylation) stress were 34.1 ± 28.1%, 186 ± 28.1% and 94 ± 5.8% higher, respectively, in 36-month hearts and these findings were highly correlated with increases in left ventricular wall thickness (r>0.669; r>0.710 and p<0.01, respectively). Regression analysis showed that increases in cardiac oxidative-nitrosative stress with aging were significantly correlated with changes in the expression and/or regulation of proteins involved in transcriptional (NF-κB) activities, signaling (mitogen activated protein kinases along with Src), apoptotic ( Bcl-2, Traf-2), and cellular stress (HSPs). These results suggest that the aging F344/NXBN heart may be highly suited for unraveling the molecular events that lead to age-associated alterations in cardiac oxidative stress.

Protein Kinase C Activity In Mouse Eggs Regulates Gamete Membrane Interaction, Hiroto Akabane

Theses, Dissertations and Capstones

Every mammalian life develops from one cell after fertilization of an egg by the sperm. The molecular pathways governing this event are still poorly understood. Numerous reports indicate that mammalian eggs highly express various protein kinase C (PKC) isoforms. Accordingly, we hypothesize that PKC activity in the egg plays an important role during egg-sperm membrane binding and fusion. In this study, we tested our hypothesis in mouse gametes using two types of PKC inhibitors (calphostin c and staurosporine) and the typical PKC activator, phorbol ester 12-tetradecanoylphorbol-13 acetate (PMA). After treatment with the individual drug, eggs were inseminated with sperm. The …

Thimerosal-Induced Neuritoxicity: Apoptosis Occurs Through A Mitochondrial-Mediated Pathway Via The Jnk Signaling Pathway, Michelle L. Herdman

Theses, Dissertations and Capstones

Thimerosal is an organic mercurial containing an ethylmercury moiety attached to the sulfur atom of thiosalicylate. Since the 1930s, thimerosal has been used as an antiseptic and a preservative in a wide variety of products, including medicinal preparations administered to children and pregnant women. Past exposures to mercurials have indicated that mercury is a neurotoxin, and can also affect the kidney, skin, eyes, and immune system. Additionally, fetuses exposed to mercurials are more susceptible to toxicity because the nervous system is continuously developing. However, despite its widespread use, thimerosal was only studied on a limited basis until the end of …

Regulation Of Biofilm Formation Of Pseudomonas Aeruginosa, Nathaniel Edwards Head

Theses, Dissertations and Capstones

Cystic fibrosis (CF) is the most common, autosomal recessive lethal genetic disease in the Caucasian population, resulting from a malfunctioned cystic fibrosis transmembrane conductance regulator (CFTR) and leading to bacterial lung infections. P. aeruginosa, an opportunistic pathogen, establishes a chronic infection in CF with a phenotype of overproduction of an exopolysaccharide (alginate) due to host-directed mutagenesis. While free-floating planktonic bacteria can be properly cleared from the CF lung, P. aeruginosa, along with alginate production, establishes an infection in the form of a biofilm which supports its survival in nature and in vivo. As a result, genomic structure, …