Medicine and Health Sciences Commons^™

Tcf4 Is A Key Mediator Of Cell Identity And Oncogenesis In Neuroblastoma, Nour Aljouda

Theses and Dissertations (ETD)

Neuroblastomas (NB) are embryonal childhood tumors that derive from the multipotent neural crest cells (NCCs) of the peripheral nervous system. NB accounts for more than 15% of all childhood cancer-related deaths. Despite the most intensive multimodal therapy, more than 50% of patients with high-risk NB relapse with often fatal, resistant disease. Novel therapies are desperately needed to improve cure rates. Previous studies proposed that the deregulation of normal neural crest developmental programs contributes to NB oncogenesis by retaining the highly migratory and proliferative traits of NCCs. Thus, activation or repression of neural crest developmental pathways have been implicated in NB …

Methods Development In Inflammatory Bowel Disease, Andrew B. Steimke

Theses and Dissertations (ETD)

Inflammatory bowel disease (IBD) is a disease that is classified into two subtypes: ulcerative colitis (UC) and Crohn’s disease (CD). Symptoms can range from mild discomfort to requiring surgical intervention and affects approximately 1-in-200 adults in America alone, with global incidence rates increasing. While many treatments exist for IBD, perhaps the main reason for the lack of a cure is that there are many different pathogeneses that all lead to a very similar expression of symptoms. Over 240 IBD loci have been identified to date, yet the causative allele that drives the association has only been identified in ~60 of …

A Cloning-Free Recyclable System For Crispr-Cas9 Mediated Mutant And Reversion Construction In Candida Albicans Clinical Isolates, Amanda K. Vogel

Theses and Dissertations (ETD)

Candida albicans is a ubiquitous opportunistic fungal pathogen and one of the most prevalent causes of fungal diseases worldwide. The reference isolate SC5314 is one of the most widely used strains for both experimental and genetic studies, but it is becoming increasingly evident that genetic diversity in clinical isolates plays an important role in antifungal resistance, virulence, and pathogenicity. These recent discoveries highlight the need for genetic tools that are capable of investigating genes in multiple strain backgrounds. Here we build on the SAT1-flipper method and combine it with CRISPR-Cas9 technology to achieve cloning-free homozygous deletion in a single transformation …

Using Crispr Gene Editing To Prevent Accumulation Of Lipids In Hepatocytes, Erin Young, Cem Kuscu, Christine Watkins, Murat Dogan

Longitudinal Scholar's Project

CRISPR gene editing is a molecular technology that can be used to silence gene expression. In this experiment, genes that are known to play a role in lipid accumulation in hepatocytes were targeted. Specifically, levels of fatty acid transport proteins 2 and 5 (FATP2 & 5) have been shown to be elevated in cases of non-alcoholic fatty liver disease. The goal of this experiment was to reduce expression of these genes by using a dead Cas9 (dCas9) protein with an attached inhibitory domain (KRAB) that acts on the promotor region. When measuring the mRNA expression, it was determined that the …

Identifying The Molecular Cause Of Extreme Endoplasmic Reticulum Dilation In Pediatric Osteosarcoma And Its Relationship To The Disease, Rachael Wood

Theses and Dissertations (ETD)

Pediatric osteosarcoma tumors are characterized by an unusual abundance of grossly dilated endoplasmic reticulum and an immense genomic instability that has complicated identifying new effective molecular therapeutic targets. Here we report a novel molecular signature that encompasses the majority of 108 patient tumor samples, PDXs and osteosarcoma cell lines. These tumors exhibit reduced expression of four critical COPII vesicle proteins that has resulted in the accumulation of procollagen-I protein within ‘hallmark’ dilated ER. Using CRISPR activation technology, increased expression of only SAR1A and SEC24D to physiologically normal levels was sufficient to restore both collagen-I secretion and resolve dilated ER morphology …

Environmental And Genetic Factors Affecting Bone Diseases And Phenotypes In Mouse Models, Wei Dong

Theses and Dissertations (ETD)

Bone diseases and phenotypes are affected in multiple ways. We focused on studying the effects of genetic and environmental factors, especially their impact on bone properties. Firstly, we investigated the effects of β-caryophyllene (BCP), a naturally occurring dietary cannabinoid, on protecting bone from vitamin D deficiency in mice fed on a diet lacking or supplemented with vitamin D (VD). We found that the VD-deficient diet enhanced the length of femur and tibia bones (P<0.05), and increased bone volume (BV; P<0.01) and the trabecular bone volume fraction (BV/TV; P <0.01) compared to the D+ diet. When given BCP-containing diet, mice exhibited higher BV and bone mineral density (BMD; P<0.05) than the control group. The trabecular and cortical bone were also affected by VD and BCP. In addition, the inclusion of dietary BCP improved the serum concentrations of klotho (P < 0.05). In summary, these data indicate that BCP enhances the level of klotho in the serum, leading to improved bone properties and mineralization in an experimental mouse model. Under conditions lacking UV light, the D-deficient diet could affect multiple properties of bone, including trabecular and cortical bone, in mice. The D-deficient diet can also result in weight loss in mice.

My second project is to evaluate the bone properties in a mouse model with Il-1rn mutation. When knockout for IL-1rn, mice of Balb/c genomic background exhibited …

Role Of Smad2 And Smad3 On Adipose Tissue Development And Function, Roshan Kumari

Theses and Dissertations (ETD)

Introduction: Obesity and its associated metabolic syndrome are major medical problems worldwide including United States. Adipose tissue is the primary site of energy storage, playing important roles in health. Adipose tissue also has other critical functions, producing adipocytokines and contributing to normal nutrient metabolism, which in turn play important roles in satiety, inflammation, and total energy homeostasis. Activin A and activin B play important roles in maintaining body composition and energy homeostasis. This dissertation highlights the role of activin/SMADs signaling in adipose tissue development, function, and maintenance.

SMAD2/3 proteins are downstream mediators of transforming growth factor-β (TGFβ) family signaling, including …

Genomic Characterization Of Sickle Cell Mouse Models For Therapeutic Genome Editing Applications, Kaitly Jensen Woodard

Theses and Dissertations (ETD)

Sickle cell disease (SCD) is caused by a mutation of the β-globin gene (HBB), resulting in abnormal hemoglobin molecules that polymerize when deoxygenated, forming “sickle” shaped red blood cells (RBCs). Sickle RBCs lead to anemia, multi-organ damage and pain crises, beginning the first year of life. The onset of symptoms coincides with the developmental switch of β-like globin gene expression from fetal stage γ-globin to adult stage β-globin, resulting in a shift from fetal hemoglobin (HbF, α2γ2) to adult hemoglobin (HbA, α2β2). Some individuals harbor rare genetic variants in the extended β-globin gene cluster that cause constitutively elevated postnatal HbF, …

Genetic Mechanisms Of Transcriptional Regulation In Childhood Acute Lymphoblastic Leukemia, Xujie Zhao

Theses and Dissertations (ETD)

Introduction. Advances in genomic profiling and sequencing studies have identified germline and somatic variations that are associated with childhood ALL, improving our understanding of the genetic basis of childhood acute lymphoblastic leukemia (ALL). Recent genome-wide association studies (GWAS) have identified germline genetic variations of ARID5B and, more recently, IGF2BP1 that are associated with susceptibility to ALL. Genome-wide sequencing studies also discovered a new ALL subtype characterized of ZNF384-mediated chromosomal translocations, providing new insights into genetic heterogeneity in childhood ALL. However, the underlying mechanism by which these genetic variants contribute to the transcriptional regulatory circuitries of ALL is still poorly understood. …

Investigating The Role Of Znf384 Rearrangements In Acute Leukemia, Kirsten Dickerson

Theses and Dissertations (ETD)

Chromosomal rearrangements involving ZNF384 are the defining lesion in 5% of pediatric and adult B-cell acute lymphoblastic leukemia and tumors are characterized by aberrant myeloid marker expression. Additionally, ZNF384 rearrangements are the defining lesion in nearly half of pediatric B/myeloid mixed phenotype acute leukemia. These fusions juxtapose full-length ZNF384 to the N terminal portion of a diverse range of partners, most often, transcription factors or epigenetic modifiers. It has been shown that ZNF384-rearranged tumors have a distinct gene expression profile that is consistent between disease groups and N terminal partners. Genomic analyses of patient tumors has shown that ZNF384 fusions …

Systems Genetics And Systems Biology Analysis Of Paraquat Effects In Bxd Recombinant Inbred Mice, Carolina Del Valle Torres Rojas

Theses and Dissertations (ETD)

Paraquat (PQ) is a chemical herbicide that is used in many countries including the United States. It is also highly acutely toxic to humans and has been used as a means of suicide. As PQ is applied mainly in agricultural settings, it moves to soil and well water. Chronic low dose exposure via drinking water may have adverse effects on humans, including increased risk for sporadic Parkinson’s disease (sPD). The etiology of sPD is unclear and the most accepted hypothesis states it is the result of the interaction between environmental factors and genetic susceptibility. Increasing evidence led us to infer …

Dissecting Drivers Of Basal Immunity And Acute Responses To Viral Infection, Aisha Nadia Hegab Souquette

Theses and Dissertations (ETD)

Heterogeneity in the human immune system can lead to limited vaccine efficacy, poor response to therapeutics, increased susceptibility to immune mediated diseases, and differential outcome to infection. Studies to date have suggested a role for biological, environmental, and genetic factors in immune variation; however, they are often focused on a specific subset of the population (e.g. ancestral group, age range) which can exclude phenotypes unique to a diverse population and bias results. To address this gap, we have utilized samples from healthy or influenza virus infected subjects from 8 distinct populations in 5 countries to conduct an integrative analysis of …

Genetic Variation And Sex Mediate Differential Responses To ∆-9-Tetrahydrocannabinol Among Inbred Mice, Cory Parks

Theses and Dissertations (ETD)

The plant Cannabis sativa has been used by people for both recreational and medicinal use for thousands of years, but scientific investigation of the plant and its components didn’t begin until the early nineteen hundreds when Cannabis components known as phytocannabinoids were characterized and later isolated. In the 1970’s, ∆9-tetrahydrocannabinol (THC) was isolated and recognized as the major constituent responsible for the psychoactive and intoxicating effects associated with consumption of cannabis. This opened the door for intensive research in the field that lead to the discovery of the endogenous cannabinoid system and its associated receptors, effectors of signaling, and biosynthetic …

Validation And Application Of A Novel Target-Based Whole-Cell Screen To Identify Antifungal Compounds, Christian Alexander Dejarnette

Theses and Dissertations (ETD)

Traditional approaches to drug discovery are inefficient and have several key limitations that constrain our capacity to rapidly identify and develop novel experimental therapeutics. To address this, we have devised a second-generation target-based whole-cell screening assay based on the principles of competitive fitness, which can rapidly identify target-specific and physiologically-active compounds. Briefly, strains expressing high, intermediate, and low levels of a preselected target protein were constructed, tagged with spectrally distinct fluorescent proteins (FPs), and mixed together. The pooled strains were then grown in the presence of various small molecules, and the relative growth of each strain within the mixed culture …

Somatic Mutation Detection In Leukemia-Derived Circulating Dna: Utility In Monitoring Clonal Dynamics And Disease Response In Pediatric Acute Lymphoblastic Leukemia, Sarah Hisham Abdelaziz Youssef

Theses and Dissertations (ETD)

Despite the improved outcome associated with current treatment strategies ofpediatric acute lymphoblastic leukemia (ALL), relapse still represents a major challenge. Pediatric ALL demonstrates branched evolution in response to selective pressure exerted by therapy; relapse founder clones emerge from pre-leukemic clones or minor subclones present at diagnosis. It is hence crucial to develop biomarkers capable of tracking subclones throughout therapy. Current practices for monitoring disease response in leukemia rely on the analysis of BM biopsy sample at specific time points throughout therapy. Not only the invasiveness of the BM biopsy hinders the sequential sampling, but also, the currently implied techniques are …

Revealing A Non-Canonical Role Of Anti-Apoptotic Mcl-1 In Early Embryonic Development, Xue Yang

Theses and Dissertations (ETD)

MCL-1, a well-known pro-survival BCL-2 family member, is indispensable for the survival of various cellular lineages and is also among the most frequently amplified genes in a variety of human malignancies. Gene ablation studies previously revealed that Mcl-1 deficiency leads to embryonic lethality around E3.5 during peri-implantation stage. Strikingly, the study did not detect any increase in apoptotic cells of the blastocyst, indicating a function of MCL-1 beyond regulating apoptosis. Our previous studies revealed an unrecognized role of MCL-1 in promoting mitochondrial physiology, which is independent of its classical anti-apoptotic function and requires being imported into the mitochondrial matrix. In …

Environmental Signaling Through The Target Of Rapamycin Complex 1 (Torc1) And The Regulation Of Epigenetic Mechanisms, Jason J. Workman

Theses and Dissertations (ETD)

The gene expression profile of a eukaryotic cell is responsive to a variety of extracellular stimuli, including nutrient availability, which allows cells to toggle between anabolism and catabolism based on the favorability of their environment. Much of this information is relayed through signaling complexes, such as the target of rapamycin complex 1 (TORC1), to downstream chromatin modifying enzymes. These enzymes impact the gene regulatory process through altered histone post-translation modifications, changes in chromatin structure, and docking of chromatin regulatory complexes. Yet, despite preliminary studies suggesting that TORC1 affects epigenetic mechanisms, including histone H3 lysine 56 acetylation (H3K56ac), almost nothing is …

Functional Analysis Of Genomic Variation And Impact On Molecular And Higher Order Phenotypes, Ashutosh Kumar Pandey

Theses and Dissertations (ETD)

Reverse genetics methods, particularly the production of gene knockouts and knockins, have revolutionized the understanding of gene function. High throughput sequencing now makes it practical to exploit reverse genetics to simultaneously study functions of thousands of normal sequence variants and spontaneous mutations that segregate in intercross and backcross progeny generated by mating completely sequenced parental lines. To evaluate this new reverse genetic method we resequenced the genome of one of the oldest inbred strains of mice—DBA/2J—the father of the large family of BXD recombinant inbred strains. We analyzed ~100X wholegenome sequence data for the DBA/2J strain, relative to C57BL/6J, the …

Downregulation Of Prdm16 Is Critical For Hoxb4-Mediated Benign Hsc Expansion In Vivo, Hui Yu

Theses and Dissertations (ETD)

Overexpression of HOXB4 in hematopoietic stem cells (HSCs) leads to increased self-renewal without causing hematopoietic malignancies in transplanted mice. The molecular basis of HOXB4-mediated benign HSC expansion in vivo is not well understood. To gain further insight into the molecular events underlying HOXB4-mediated HSC expansion, we analyzed gene expression changes at multiple time points in Lin-Sca1+c-kit+ (LSK) cells from mice transplanted with bone marrow (BM) cells transduced with a MSCV-HOXB4-ires-YFP vector. A distinct HOXB4 transcriptional program was reproducibly induced and stabilized by 12 weeks after transplant. Dynamic expression changes were observed in genes critical for HSC self- renewal as well …

Effect Of Nedd4 Haploinsufficiency On Insulin Sensitivity, Adiposity And Neuronal Behaviors, Jingjing Li

Theses and Dissertations (ETD)

The neural precursor cell expressed developmentally down-regulated gene 4 (NEDD4) is a HECT-type E3 ubiquitin ligase that has received broad attention in recent years. Many of its reported substrates are active players in metabolism, implying a potential role of NEDD4 itself in metabolic regulation. Since homozygous Nedd4 deletion leads to embryonic or perinatal lethality, we investigated the function of NEDD4 in metabolic regulation in vivo, using Nedd4- haploinsufficient mice in a high fat diet-induced obesity (HFDIO) model.

Our studies show that Nedd4-haploinsufficient mice fed a normal diet (ND) exhibited decreased body weight in both genders and proportionally reduced tissue mass …

The Role Of Mcl-1 In The Heart: Gateway From Life To Death, Xi Wang

Theses and Dissertations (ETD)

MCL-1 is an essential BCL-2 family member that promotes the survival of multiple cellular lineages, but its role in cardiac muscle has remained unclear. Here, we have demonstrated that cardiac-specific ablation of Mcl-1 results in a rapidly fatal, dilated cardiomyopathy preceded by loss of myofibrils and cardiac contractility, abnormal mitochondria ultrastructure, defective mitochondrial respiration, and impaired autophagy. Genetic ablation of both pro-apoptotic effectors (Bax and Bak) could largely rescue the lethality and impaired cardiac function induced by Mcl-1 deletion. However, Mcl-1-, Bax-, and Bak-deficient hearts still revealed mitochondrial ultrastructural abnormalities and displayed deficient mitochondrial respiration, and are hypersensitive to chronic …

Autoimmune Susceptibility Imposed By Public Tcrβ Chains, Yunqian Zhao

Theses and Dissertations (ETD)

The major histocompatibility complex (MHC) is the strongest genetic risk factor for autoimmunity. It acts together with a corresponding TCR repertoire, yet, considering the extent of the repertoire's diversity, how this imposes disease susceptibility on a population is not well understood. We address the hypothesis that shared or public TCR, those present in most individuals, modulate autoimmune risk. High resolution analyses of autoimmune encephalomyelitis-associated T-cell receptor β chain (TCRβ) showed preferential utilization of public TCR sequences, implicating them in pathogenesis. Disease-associated public TCRβ, when transgenically expressed in association with endogenously rearranged T-cell receptor α chain (TCRα), could further endow unprimed …

Gene Therapy And Stem Cell Therapy To Improve The Outcome Of Human Islet Transplantation, Hao Wu

Theses and Dissertations (ETD)

Since its first introduction in 1990s, the Edmonton Protocol for human islet transplantation has helped more than 500 patients with type 1 diabetes worldwide and met great success from bench to bedside. The Edmonton Protocol involves isolating islets from a cadaveric donor pancreas by enzymatic digestion and infusing into the patient's portal vein. Each recipient usually receives islets from two or three donors for an optimal outcome and is dosed with two immunosuppressive drugs, sirolimus and tacrolimus and a monoclonal antibody drug daclizumab to prevent the graft rejection. However, despite the administration of immunosuppressive drugs and the recent improvement in …

Functional Study Of Hemogen Knockout Mouse Model, Peng Gao

Theses and Dissertations (ETD)

Mouse Hemogen (Hemgn) is regarded as a homologue of human Erythroid Differentiation Associated Gene (EDAG). EDAG overexpression has been postulated for association with some leukemia cases. Meanwhile, Hemgn has been found to contribute to Hoxb4 mediated hematopoietic stem cell expansion. Based on these postulations and evidences, a Hemgn knockout mouse model has been generated to study its function in normal and stress hematopoiesis. I confirmed the Hemgn expression in hematopoietic organs including bone marrow and spleen, as well as round spematids in testis. Hemgn is expressed in mouse hematopoietic stem cells and erythroid progenitor cells. Moreover, Hemgn was also found …

Anti-Apoptotic Mcl-1 Localizes To The Mitochondrial Matrix And Couples Mitochondrial Fusion To Respiration, Rhonda Perciavalle

Theses and Dissertations (ETD)

MCL-1, an anti-apoptotic BCL-2 family member that is essential for the survival of multiple cell lineages, is also among the most highly amplified genes in cancer. Although MCL-1 is known to oppose cell death, precisely how it functions to promote survival of normal and malignant cells is poorly understood. Here, I report that different forms of MCL-1 reside in distinct mitochondrial locations and exhibit separable functions. On the outer mitochondrial membrane, a MCL-1 isoform acts like other anti-apoptotic BCL-2 molecules to antagonize apoptosis, whereas an amino-terminally truncated isoform of MCL-1 that is imported into the mitochondrial matrix is necessary to …

The Role Of Pkd1 In Mouse Inner Ear Hair Cells, Katherine Ann Steigelman

Theses and Dissertations (ETD)

The polycystic kidney disease-1 (Pkd1) gene encodes a large transmembrane protein (polycystin-1 or PC-1) that is reported to function as a fluid flow-sensor in the kidney. As a member of the transient receptor potential (TRP) family, PC-1 has also been hypothesized to play a role in the elusive mechanoelectrical transduction (MET) channel in inner ear hair cells based on PC-1 role of fluid flow sensing and calcium uptake into renal epithelial cells. However, two independent mouse lines with PC-1 mutations exhibit normal MET channel function despite hearing loss and ultra-structural abnormalities of stereocilia that remain properly polarized at …

Systems Biology Approach To Identifying Host Interactive Pathways Modulating The Severity Of Streptococcal Sepsis, Nourtan Fatthy Abdeltawab

Theses and Dissertations (ETD)

Clinical outcomes of infectious diseases are controlled by complex interactions between the host and the pathogen. Epidemiological, genetic and molecular studies in my mentor’s laboratory provided evidence that in invasive Group A streptococcal (GAS) infections, genetic variations in both bacteria and patients influenced the severity of GAS sepsis. Allelic variations in class II human leukocyte antigens (HLA) contributed significantly to differences in the severity of group A streptococcal sepsis caused by the same virulent strain of the bacteria. HLA class II molecules present streptococcal superantigens (SAgs) to T cells, and variations in HLA class II molecules can strongly influence SAg …

Uncovering P53 Mutations And Abnormal Gene Expression In Pediatric Adrenocortical Cancer, Alina Nico West

Theses and Dissertations (ETD)

Pediatric adrenocortical cancer is extremely rare and often fatal (approximately 0.3-0.4 cases per million worldwide; 50% 5-year survival). The incidence of pediatric adrenocortical cancer in southern Brazil is 10-15 times higher than the worldwide incidence. Due to the rarity of adrenocortical cancer, especially in children, underlying gene dysregulation and mechanisms of tumorigenesis of the adrenal gland are very poorly described in the literature. However, it is well-known that the tumor suppressor p53, which is mutated in over 50% of all human cancers, is commonly mutated in pediatric adrenocortical cancer. In addition, evidence strongly suggests that if a child has adrenocortical …

Genetic Control Of Eye Development, A Case Study Focused On The Murine Mutation Belly Spot And Tail (Bst), Qing Tang

Theses and Dissertations (ETD)

Development of the eye is controlled by a network of genes, often conserved, that regulate the timing and location of cellular differentiation. One approach to understanding this network of genes and their interaction is to focus on mutations, spontaneous or induced, that predictably disrupt the proper function of such networks, and by examining the effect of such disruption on the function of other genes.

The Belly spot and tail (Bst) semi-dominant mutation, mapped to mouse Chromosome 16, leads to developmental defects of the eye, skeleton, and coat pigmentation. In the eye, the mutant phenotype is characterized by the presence of …