Medical Genetics Commons^™

The Krüppel-Like Factor 2 And Krüppel-Like Factor 4 Genes Interact To Maintain Endothelial Integrity In Mouse Embryonic Vasculogenesis, Aditi R. Chiplunkar, Benjamin C. Curtis, Gabriel L. Eades, Megan S. Kane, Sean J. Fox, Jack L. Haar, Joyce A. Lloyd

Human and Molecular Genetics Publications

Background Krüppel-like Factor 2 (KLF2) plays an important role in vessel maturation during embryonic development. In adult mice, KLF2 regulates expression of the tight junction protein occludin, which may allow KLF2 to maintain vascular integrity. Adult tamoxifen-inducible Krüppel-like Factor 4 (KLF4) knockout mice have thickened arterial intima following vascular injury. The role of KLF4, and the possible overlapping functions of KLF2 and KLF4, in the developing vasculature are not well-studied.

Results Endothelial breaks are observed in a major vessel, the primary head vein (PHV), in KLF2-/-KLF4-/- embryos at E9.5. KLF2-/-KLF4-/- embryos die by E10.5, which is earlier than either single …

Regulation Of The Mouse And Human Β-Globin Genes By Krüppel Like Transcription Factors Klf1 And Klf2, Yousef N. Alhashem

Theses and Dissertations

Krüppel-like factors KLF1 and KLF2 are closely related transcription factors with three zinc finger domains in their carboxy-termini. KLF1 (erythroid Krüppel-like factor, or EKLF) plays essential roles in embryonic and adult erythropoiesis. KLF2 is a positive regulator of the mouse and human embryonic β- globin genes. KLF1 and KLF2 have overlapping roles in embryonic erythropoiesis, as demonstrated using single and double knockout (KO) mouse models. Ablation of the KLF1 or KLF2 gene causes embryonic lethality, and double KO embryos are more anemic and die sooner than either single KO. We have shown that KLF1 and KLF2 positively regulate the human …

From Linkage To Gwas: A Multifaceted Exploration Of The Genetic Risk For Alcohol Dependence, Amy Adkins

Theses and Dissertations

Family, twin and adoption studies consistently suggest that genetic factors strongly influence the risk for alcohol dependence (AD). Although the literature supports the role of genetics in AD, identification of specific genes contributing to the etiology of AD has proven difficult. These difficulties are due in part to the complex set of risk factors contributing to the development of AD. These risk factors include comorbidities with other clinical diagnoses and behavioral phenotypes (e.g., major depression), physiological differences that contribute to the differences between people in their level of response to ethanol (e.g., initial sensitivity) and finally the large number of …

The Role Of P62 In Osteoclastogenesis And Paget’S Disease Of Bone, Tamer Hadi

Theses and Dissertations

Paget’s disease (PDB) is the second most common metabolic bone disease after osteoporosis, affecting up to 3% of adults over age 55. It is characterized by focal lesions of bone resorbed by hyperactive osteoclasts coupled with rapid formation of highly disorganized, low quality bone formed by osteoblasts. Such lesions cause skeletal deformity, fractures, and other symptoms that significantly decrease quality of life. In 2001, mutations in the SQSTM1/p62 gene were found in a subset of Paget’s patients. The work summarized in this dissertation sought to answer two broad questions: what is the function of p62 in normal bone homeostasis and …

On The Genetic And Environmental Associations Between Body Composition, Depression Symptoms And Smoking Behavior., Roseann Peterson

Theses and Dissertations

Obesity is a serious public health crisis and recent estimates of its incidence are the highest in United States history, with 35% and 17% of American adults and children affected, respectively. The clinical definition of adult obesity is operationalized as a body mass index (BMI) greater than 30 kg/m2. Although the prevalence of common obesity has increased dramatically over the past 30 years–largely thought to be due to changes in the environment, such as high calorie diets and sedentary lifestyles—twin and family studies have shown consistently that relative body weight is under considerable genetic influence in both children and adults, …

Examining Alcohol Dependence And Its Correlates From A Genetically Informative Perspective, Laura Hack

Theses and Dissertations

Alcohol dependence (AD) is a serious and common public health problem that contributes to great societal, medical, and legal costs. It has taken work from multiple disciplines, including developmental psychology, genetic epidemiology, and molecular genetics, to achieve our current understanding of environmental and genetic risk factors for AD as well as its variable developmental trajectories. Nevertheless, there is still much to be learned in order to improve treatment outcomes. One approach to augmenting our understanding of this disorder is through genetically informative study designs that either examine risk in aggregate or assess specific susceptibility variants. In this dissertation, we utilize …

Using Genetic Information In Risk Prediction For Alcohol Dependence, Jia Yan

Theses and Dissertations

Family-based and genome-wide association studies (GWAS) of alcohol dependence (AD) have reported numerous associated variants. The clinical validity of these variants for predicting AD compared to family history has not yet been reported. These studies aim to explore the aggregate impact of multiple genetic variants with small effect sizes on risk prediction in order to provide a clinical interpretation of genetic contributions to AD. Data simulations showed that given AD’s prevalence and heritability, a risk prediction model incorporating all genetic contributions would have an area under the receiver operating characteristic curve (AUC) approaching 0.80, which is often a target AUC …

Role Of Nucleosome Remodeling Factor (Nurf) In Tumorigenesis Using A Breast Cancer Mouse Model, Aiman Alhazmi

Theses and Dissertations

Understanding the impact of epigenetic mechanisms on tumorigenesis is essential, as epigenetic alterations are associated with tumor initiation and progression. Because epigenetic changes are reversible, they are potential targets for cancer therapy. Nucleosome Remodeling Factor (NURF) is a chromatin-remodeling complex that regulates gene expression by changing nucleosome positioning along the DNA sequence. Previous studies have shown a role for NURF in embryonic development as well as regulating genes involved in tumor progression. In this work we investigated the impact of eliminating NURF function in tumorigenesis in vivo. BALB/c mice challenged with syngeneic 67NR breast cancer cell lines, injected into the …

The Role Of Tetraspanin-8 In Astrocyte Elevated Gene-1 Mediated Progression Of Hepatocellular Carcinoma, Maaged Akiel

Theses and Dissertations

Hepatocellular carcinoma (HCC) is a devastating form of liver cancer that accounts for 80% of liver cancers. HCC has a poor prognosis with five-year survival of less than 12% in the United States. We in previous studies have identified Astrocyte Elevated Gene-1 (AEG-1) as an aberrantly overexpressed gene in many cancers including HCC, regulating tumor progression. Microarray studies identified the small transmembrane protein, tetraspanin8 (TSPAN8) as a downstream of AEG-1. TSPAN8 belongs to the family of TETRASPANINS with the characteristic of crossing the membrane four times, and regulating a wide range of cellular phenomena. TSPAN8 is implicated in metastasis and …

Characterizing The Role Of Nucleosome Remodeling Factor (Nurf) In Tumorigenesis And Metastatic Progression Using Mouse Models Of Breast Cancer., Suehyb Alkhatib

Theses and Dissertations

Increasingly the role of epigenetic machinery as a bridge between underlying DNA sequence and cellular phenotype is being discovered. The establishment of a myriad of unique cellular types sharing identical gene sequences in a multicellular organism gives a broad sense for the inherent role of epigenetic influence on cell differentiation. Importantly, the epigenetic mechanisms involved in establishing cell identity unsurprisingly contribute to diseased states, including cancer. Recent research continues to elucidate contributory roles of epigenetic mechanisms, such as DNA methylation, histone modification, and microRNA regulation, in human cancers. Additionally, chromatin remodelers, such as the Nucleosome Remodeling Factor (NURF), have been …

Elucidating Genetic And Environmental Influences On Alcohol-Related Phenotypes, Jacquelyn Meyers

Theses and Dissertations

Decades of work has led researchers to believe that risk for complex behavioral phenotypes, such as alcohol use disorders, is likely influenced by multiple genes of small effect acting in conjunction with each other and the environment. Currently, the field of psychiatric genetics is developing methodologies for the identification of genetic risk variants that predispose individuals to the development of complex behavioral disorders. Several challenges related to the complex and polygenic nature of these phenotypes, must be considered. This dissertation study attempts to address these important challenges in the context of alcohol use disorders and related phenotypes. A rich twin …

Otx But Not Mitf Transcription Factors Are Required For Zebrafish Rpe Development, Brandon Lane

Theses and Dissertations

Mitf and Otx transcription factors have been identified as essential to the development of the retinal pigmented epithelium (RPE), but the relationship between these factors and their specific role in the RPE developmental pathway have not been clearly defined. The role of the two Mitf transcription factors (Mitfa and Mitfb) and two Otx transcription factors (Otx1a and Otx2) in zebrafish RPE development was explored in these experiments. The loss of Mitf activity in mitfa, mitfb, or double mitf null mutant fish lines had no effect on RPE pigmentation or development. The loss of Otx2 activity through morpholino knockdown produced a …

Tgf-Beta Receptors And Alcohol Sensitivity In Drosophila, Kristyn Sennett

Theses and Dissertations

Clic proteins influence ethanol-related behavior in flies and other species and also mediate TGF-β signaling. These findings suggest that Clics and the TGF-β signaling pathway might work together to modulate behavioral responses to ethanol. I used the Drosophila model to address the hypothesis that TGF-β signaling is important for ethanol sensitivity. Ethanol sensitivity was blunted by multiple transposon insertions in the TGF-β receptor gene thickveins. Collectively, however, I found no consistent correlation between expression of thickveins and altered ethanol sensitivity in flies harboring transposons. I therefore also assessed ethanol sensitivity in flies with loss of function point mutations in thickveins. …

Quantitative Genetic Methods To Dissect Heterogeneity In Complex Traits, T. Bernard Bigdeli

Theses and Dissertations

Etiological models of complex disease are elusive[46, 33, 9], as are consistently replicable findings for major genetic susceptibility loci[54, 14, 15, 24]. Commonly-cited explanations invoke low-frequency genomic variation[41], allelic heterogeneity at susceptibility loci[33, 30], variable etiological trajectories[18, 17], and epistatic effects between multiple loci; these represent among the most methodologically-challenging issues in molecular genetic studies of complex traits. The response has been con- sistently reactionary—hypotheses regarding the relative contributions of known func- tional elements, or emphasizing a greater role of rare variation[46, 33] have undergone periodic revision, driving increasingly collaborative efforts to ascertain greater numbers of participants and which assay …

Mosaicism For Trisomy21: Utility Of Array-Based Technology For Its Detection And Its Influence On Telomere Length And The Frequency Of Acquired Chromosome Abnormalities, Chariyawan Charalsawadi

Theses and Dissertations

The primary aim of this study was to determine the effectiveness of array-based technology for detecting and quantifying the presence of mosaicism. This aim was achieved by studying individuals having mosaicism for Down syndrome. SNP arrays were performed on 13 samples from individuals with mosaicism for trisomy 21, 13 samples from individuals with normal chromosome 21complements (negative controls) and 5 samples from individuals with full or partial trisomy 21 (positive controls). In addition, BAC arrays were processed on 6 samples from individuals with mosaicism for trisomy 21, 3 negative controls and 1 positive control. These studies have shown that array-based …

Creation Of Multilinage Adult Stem-Like Cells From Terminally Differentiatied Fibroblasts, John Moore

Theses and Dissertations

Induced Pluripotent Stem cells (iPScs) are artificially generated cells that demonstrate multilineage differentiation potential. These cells demonstrate similar morphology and high differentiation potential to Embryonic Stem Cells (ESCs). Generation of these cells from a terminally differentiated cell line requires activation of the core pluripotency genes Nanog, Oct4, and Sox2 as well as an oncogenic stimulus such as c-Myc. Here we examine the effect of the Human Pappiloma Virus derived proteins E6 and E7 on the ability of a terminally differentiated fibroblast cell line to a more primitive state and examine its multilineage differentiation capacity. In this paper, we attempt to …

A Review Of Common And Rare Genetic Variants In Schizophrenia, Jonathan Luedders

Theses and Dissertations

Genetic epidemiology has shown a large role for genetic influences on schizophrenia. However, the nature of the variants involved is debated. The common disease-common variant (CDCV) hypothesis suggests that schizophrenia is caused by common alleles with small effect sizes. According to the common disease-rare variant (CDRV) hypothesis, schizophrenia is caused by rare variants with large effect sizes. In recent years, evidence has been found for both common and rare variants in schizophrenia. Several SNPs have been associated with schizophrenia through genome-wide association studies (GWAS), supporting the CDCV hypothesis. In support of the CDRV hypothesis, individuals with schizophrenia have been found …

Expression Profiling And Functional Validation Of Micrornas Involved In Schizophrenia And Bipolar Disorder, Albert H. Kim

Theses and Dissertations

MicroRNAs (miRNAs) are a family of small non-coding RNAs that regulate gene expression at both the mRNA and protein levels. MiRNAs have been shown to affect neuronal differentiation, synaptosomal complex localization and synapse plasticity, all functions thought to be disrupted in schizophrenia. We investigated the expression of 667 miRNAs (miRBase v.13) in the prefrontal cortex of individuals with schizophrenia (SZ, N = 35) and bipolar disorder (BP, N =35) using a real-time PCR-based Taqman Low Density Array (TLDA). After extensive QC steps, 441 miRNAs were included in the final analyses. At a FDR of 10%, 22 miRNAs were identified as …

Racial Differences In The Genetics Of Preeclampsia, Lori Hill

Theses and Dissertations

Preeclampsia (PE), characterized by hypertension and proteinuria after 20 weeks of gestation, affects 5-8% of pregnancies worldwide. Although preeclampsia is a significant cause of maternal and perinatal mortality and morbidity, its etiology remains to be elucidated. Racial differences have been observed for preeclampsia, with U.S. Blacks having higher rates and more severe disease, compared to U.S. Whites and Hispanics. One potential source of racial differences in preeclampsia is genetic variation between populations. Genetic susceptibility to preeclampsia is well established, but the specific contributions of maternal vs. fetal genes, and how these vary among racial groups is poorly understood. This dissertation …

Heat Shock Proteins As Novel Cancer Therapeutics: Targeting The Hallmarks Of Cancer, Chao Li

Theses and Dissertations

Molecular chaperones, commonly known as heat shock proteins (HSPs), are essential for mammalian cells to maintain homeostasis, and HSPs function by inducing an ATPase-coupled structural change, followed by interactions with diverse co-chaperones and over 200 client proteins implicated in many critical signaling networks. These highly expressed HSPs participate in the onset and progression of several human diseases including cancer, and their connection with tumorigenesis has facilitated research and clinical trials related to targeting HSPs as a novel anti-tumor therapy. The predominant mechanism of chaperone inhibition is through either disruption of the HSP association with client protein or an altered binding …

The Natural Polyphenol Resveratrol Potentiates The Lethality Of Hdac Inhibitors In Acute Myelogenous Leukemia Cells Through Multiple Mechanisms., Alae Abod Yaseen

Theses and Dissertations

This study examined the mechanisms underlying the interactions between the natural polyphenol Resveratrol and HDAC inhibitors in both U937 myelomonocytic leukemia cell line and blood samples from AML patients and normal cord blood. Simultaneous exposure to Resveratrol and HDAC inhibitors (Vorinostat-SAHA or Panobinostat-LBH589) resulted in potentiating the lethality caused by any single agent of the combination, this interaction found to be synergistic at multiple concentrations. Exposing U937 cells to minimal toxic doses of Resveratrol and HDACIs results in release of mitochondrial pro-apoptotic proteins AIF and cytochrome c, pro-apoptotic caspase activation especially caspase-8, and induction of DNA damage. These events were …

Pediatrician Perceptions Of The Patient-Centered Medical Home Model, Christopher Ray

Theses and Dissertations

The Patient-Centered Medical Home (PCMH) is an emerging model of health care designed to provide a simpler, more effective health care experience. The model places heavy emphasis on the concept of every patient having a "personal physician" who is the point of access for all health care needs and concerns. The personal physician integrates all relevant health care information to provide the patient with a holistic picture of his health. The supposed benefits of the PCMH model include an improved patient experience, increased effectiveness of care, increased efficiency of care, greater access to care, among others. Only now is evidence …

Approaches For Enhancing Therapeutic Efficacy Of A Novel Il-10 Gene Family Member: Mda-7/Il-24, Belal Azab

Theses and Dissertations

Melanoma differentiation associated gene-7 (mda-7) was discovered in the Fisher laboratory by subtraction hybridization of temporally spaced subtracted cDNA libraries prepared from terminally differentiated human melanoma cells treated with human fibroblast interferon (IFN-β) and the protein kinase C activator mezerein (MEZ), an approach called ‘differentiation induction subtraction hybridization’ (DISH). mda-7 is located in human chromosome 1q32–33 and based on sequence homology, chromosomal localization, and its functional properties, the mda-7 gene is now classified as a member of the IL-10 family of cytokines and named IL-24. The mda-7/IL-24 cDNA encodes a protein of 206-amino acids with a predicted size of ~24-kDa, …

The Effects Of Age And Heterochromatin On Frequencies Of Acquired Chromosomal Aneuploidy In Uncultured Human Leukocytes, Noran Aboalela

Theses and Dissertations

While age-related sex chromosomal aneuploidy is a well-characterized phenomenon, the relationship between autosomal loss and age remains unclear. The emergence of the specific and highly sensitive fluorescence in situ hybridization (FISH) technology has enabled investigators to study interphase cells, thereby overcoming problems inherent with the study of metaphase spreads for acquired aneuploidy assessment. Despite all the advantages of this technique, there are some limitations that could be misleading when scoring interphase autosomal aneuploidy. In this study we show that sex chromosomal hypoploidy is correlated with age. By using a twin study design, we evaluated Y chromosome hypoploidy frequencies and found …

Haploinsufficiency Of Rai1 And Its Effect On Bdnf Expression, Sun Kim

Theses and Dissertations

Smith-Magenis Syndrome (SMS) [OMIM, #182290] is a congenital anomaly and mental retardation (MCA/MR) syndrome associated with deletion of chromosome17p11.2 [1]. The clinical phenotype has been well described and includes minor craniofacial anomalies, self-injurious behaviors as well as sleep disturbances, speech delays, and obesity [1,2,3]. The incidence of SMS is estimated to be ~ 1:15,000 - 25,000 births [2,6]. Among SMS patients, ~90% are comprised of 17p11.2 deletions, while ~10% have RAI1 mutations [8]. All 17p11.2 deletions associated with SMS include RAI1 deletion [10]. RAI1 is thought to function as a transcriptional factor although its cellular role is still unclear. First, …

The Mechanism Of Obesity In Rai1+/- Mice, Kristie Schmidt

Theses and Dissertations

Smith-Magenis syndrome (SMS) is a genetic disorder caused by a deletion or mutation of the retinoic acid induced 1 (RAI1) gene on chromosome 17p11.2 that results in haploinsufficiency. SMS patients with a deletion account for 90% of the cases, while the other 10% have a mutation in RAI1. The syndrome is characterized by cognitive impairment, craniofacial abnormalities, sleep disturbances, developmental delay, obesity, and behavioral phenotypes. SMS is thought to affect 1:25,000 live births, although due to similar infantile phenotypes with Down syndrome and Prader-Willi syndrome, SMS may be mis- or under-diagnosed. In a study of 54 children, it was shown …

Identification And Characterization Of A Second Wolfram Syndrome Gene, Sami Amr

Theses and Dissertations

Wolfram Syndrome (WFS) is a debilitating autosomal recessive neurodegenerative disorder characterized by juvenile onset insulin dependent diabetes mellitus (DM) and optic atrophy (OA) as well as a number of neurological and endocrine complications that result in early death due to respiratory complications. Previous research has mapped Wolfram syndrome to chromosome 4p16.1 and the disease has been attributed to mutations in the WFS1 gene affecting the WFS1 protein (wolframin), an ER membrane glycoprotein that plays an important role in the unfolded protein response (UPR) and in intracellular Ca2+ homeostasis. An additional locus for WFS on chromosome 4q22-24 was identified by linkage …

Mechanisms Associated With Aging And Age-Related Disease In Drosophila, Melanie Jones

Theses and Dissertations

Aging is an intrinsic process that is independent of obvious disease. In contrast to normal aging, age-related diseases are conditions that typically manifest at advanced ages, are associated with explicit pathology and cause disability and premature death. We used Drosophila as a model to investigate the molecular-genetic mechanisms associated with aging and age-related disease. Age-related locomotor impairment (ARLI) is a serious condition for the elderly and greatly impacts their quality of life. Toward identifying genes and mechanisms that influence ARLI, we performed a forward genetic screen using Drosophila mutants. This screen identified a loss of function mutant in PDK1, a …

Identification Of Loci Contributing To The Smith-Magenis Syndrome-Like Phenotype And Molecular Evaluation Of The Retinoic Acid Induced 1 Gene, Stephen Williams

Theses and Dissertations

Smith-Magenis syndrome (SMS) is a multiple congenital abnormalities intellectual disability syndrome that results from a deletion of chromosome 17p11.2 or mutation of the retinoic acid inducted one gene (RAI1). SMS is characterized by a multitude of phenotypic features including craniofacial defects, short stature, obesity, intellectual disability, self-abusive behavior, sleep disturbance and behavioral abnormalities. Interestingly, although SMS is a clearly defined syndrome with a known molecular change at its foundation, ~40% of all candidate cases sent to the Elsea lab for evaluation do not have a mutation or deletion of RAI1. We hypothesize that at least one other locus must be …

Regulation Of Telomerase Expression In Stem Cell Reprogramming, Patrick Sachs

Theses and Dissertations

A great need exists for an abundant, easily accessible source of patient-specific cells that will function for use in regenerative medicine. One promising source is the adult stem cell derived from adipose tissue (ASCs). Isolated from waste lipoaspiration, these cells could serve as a readily available source for the regeneration of damaged tissues. To further define the biology of ASCs, we have isolated multiple cell strains from different adipose tissue sources, indicating wide-spread distribution in the body. We find that a widely used set of cell surface markers fail to distinguish ASCs from normal fibroblasts. However, our ASC isolations are …