Genetics and Genomics Commons^™

Comparison Between Listeria Sensu Stricto And Listeria Sensu Lato Strains Identifies Novel Determinants Involved In Infection, Jakob Schardt, Grant Jones, Stefanie Müller-Herbst, Kristina Schauer, Sarah E. F. D'Orazio, Thilo M. Fuchs

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The human pathogen L. monocytogenes and the animal pathogen L. ivanovii, together with four other species isolated from symptom-free animals, form the "Listeria sensu stricto" clade. The members of the second clade, "Listeria sensu lato", are believed to be solely environmental bacteria without the ability to colonize mammalian hosts. To identify novel determinants that contribute to infection by L. monocytogenes, the causative agent of the foodborne disease listeriosis, we performed a genome comparison of the two clades and found 151 candidate genes that are conserved in the Listeria sensu stricto species. Two factors were …

Ablation Of An Ovarian Tumor Family Deubiquitinase Exposes The Underlying Regulation Governing The Plasticity Of Cell Cycle Progression In Toxoplasma Gondii, Animesh Dhara, Rodrigo De Paula Baptista, Jessica C. Kissinger, Ernest Charles Snow, Anthony P. Sinai

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Toxoplasma genome encodes the capacity for distinct architectures underlying cell cycle progression in a life cycle stage-dependent manner. Replication in intermediate hosts occurs by endodyogeny, whereas a hybrid of schizogony and endopolygeny occurs in the gut of the definitive feline host. Here, we characterize the consequence of the loss of a cell cycle-regulated ovarian tumor (OTU family) deubiquitinase, OTUD3A of Toxoplasma gondii (TgOTUD3A; TGGT1_258780), in T. gondii tachyzoites. Rather than the mutation being detrimental, mutant parasites exhibited a fitness advantage, outcompeting the wild type. This phenotype was due to roughly one-third of TgOTUD3A-knockout (TgOTUD3A-KO) tachyzoites exhibiting deviations from endodyogeny …

Cerebral Amyloid Angiopathy In Down Syndrome And Sporadic And Autosomal-Dominant Alzheimer's Disease, María Carmona-Iragui, Mircea Balasa, Bessy Benejam, Daniel Alcolea, Susana Fernández, Laura Videla, Isabel Sala, María Belén Sánchez-Saudinós, Estrella Morenas-Rodriguez, Roser Ribosa-Nogué, Ignacio Illán-Gala, Sofía Gonzalez-Ortiz, Jordi Clarimón, Frederick A. Schmitt, David K. Powell, Beatriz Bosch, Albert Lladó, Michael S. Rafii, Elizabeth Head, José Luis Molinuevo, Rafael Blesa, Sebastián Videla, Alberto Lleó, Raquel Sánchez-Valle, Juan Fortea

Sanders-Brown Center on Aging Faculty Publications

Introduction—We aimed to investigate if cerebral amyloid angiopathy (CAA) is more frequent in genetically determined than in sporadic early-onset forms of Alzheimer's disease (AD) (early-onset AD [EOAD]).

Methods—Neuroimaging features of CAA, APOE, and cerebrospinal fluid-Aβ40 levels were studied in subjects with Down syndrome (DS, n = 117), autosomal-dominant AD (ADAD, n = 29), sporadic EOAD (n = 42), and healthy controls (n = 68).

Results—CAA was present in 31%, 38%, and 12% of cognitively impaired DS, symptomatic ADAD, and sporadic EOAD subjects and in 13% and 4% of cognitively unimpaired DS individuals and healthy controls, respectively. …

Epigenetic Impact Of Endocrine Disrupting Chemicals On Lipid Homeostasis And Atherosclerosis: A Pregnane X Receptor-Centric View, Robert N. Helsley, Changcheng Zhou

Pharmacology and Nutritional Sciences Faculty Publications

Despite the major advances in developing diagnostic techniques and effective treatments, atherosclerotic cardiovascular disease (CVD) is still the leading cause of mortality and morbidity worldwide. While considerable progress has been achieved to identify gene variations and environmental factors that contribute to CVD, much less is known about the role of “gene–environment interactions” in predisposing individuals to CVD. Our chemical environment has significantly changed in the last few decades, and there are more than 100,000 synthetic chemicals in the market. Recent large-scale human population studies have associated exposure to certain chemicals including many endocrine disrupting chemicals (EDCs) with increased CVD risk, …

Hne-Modified Proteins In Down Syndrome: Involvement In Development Of Alzheimer Disease Neuropathology, Eugenio Barone, Elizabeth Head, D. Allan Butterfield, Marzia Perluigi

Sanders-Brown Center on Aging Faculty Publications

Down syndrome (DS), trisomy of chromosome 21, is the most common genetic form of intellectual disability. The neuropathology of DS involves multiple molecular mechanisms, similar to AD, including the deposition of beta-amyloid (Aβ) into senile plaques and tau hyperphosphorylating in neurofibrillary tangles. Interestingly, many genes encoded by chromosome 21, in addition to being primarily linked to amyloid-beta peptide (Aβ) pathology, are responsible for increased oxidative stress (OS) conditions that also result as a consequence of reduced antioxidant system efficiency. However, redox homeostasis is disturbed by overproduction of Aβ, which accumulates into plaques across the lifespan in DS as well as …

Mutsβ Abundance And Msh3 Atp Hydrolysis Activity Are Important Drivers Of Ctg•Cag Repeat Expansions, Norma Keogh, Kara Y. Chan, Guo-Min Li, Robert S. Lahue

Toxicology and Cancer Biology Faculty Publications

CTG•CAG repeat expansions cause at least twelve inherited neurological diseases. Expansions require the presence, not the absence, of the mismatch repair protein MutSβ (Msh2-Msh3 heterodimer). To evaluate properties of MutSβ that drive expansions, previous studies have tested under-expression, ATPase function or polymorphic variants of Msh2 and Msh3, but in disparate experimental systems. Additionally, some variants destabilize MutSβ, potentially masking the effects of biochemical alterations of the variations. Here, human Msh3 was mutated to selectively inactivate MutSβ. Msh3^−/− cells are severely defective for CTG•CAG repeat expansions but show full activity on contractions. Msh3^−/− cells provide a single, isogenic system …

Clinical And Experimental Studies Of A Novel P525r Fus Mutation In Amyotrophic Lateral Sclerosis, Lisha Kuang, Marisa Kamelgarn, Alexandra Arenas, Jozsef Gal, Deborah Taylor, Weiming Gong, Martin Brown, Daret St. Clair, Edward J. Kasarskis, Haining Zhu

Molecular and Cellular Biochemistry Faculty Publications

Objective: To describe the clinical features of a novel fused in sarcoma (FUS) mutation in a young adult female amyotrophic lateral sclerosis (ALS) patient with rapid progression of weakness and to experimentally validate the consequences of the P525R mutation in cellular neuronal models.

Methods: We conducted sequencing of genomic DNA from the index patient and her family members. Immunocytochemistry was performed in various cellular models to determine whether the newly identified P525R mutant FUS protein accumulated in cytoplasmic inclusions. Clinical features of the index patient were compared with 19 other patients with ALS carrying the P525L mutation in the same …

The Feoabc Locus Of Yersinia Pestis Likely Has Two Promoters Causing Unique Iron Regulation, Lauren O'Connor, Jacqueline D. Fetherston, Robert D. Perry

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The FeoABC ferrous transporter is a wide-spread bacterial system. While the feoABC locus is regulated by a number of factors in the bacteria studied, we have previously found that regulation of feoABC in Yersinia pestis appears to be unique. None of the non-iron responsive transcriptional regulators that control expression of feoABC in other bacteria do so in Y. pestis. Another unique factor is the iron and Fur regulation of the Y. pestis feoABC locus occurs during microaerobic but not aerobic growth. Here we show that this unique iron-regulation is not due to a unique aspect of the Y. pestis …

Crystal Structure Of Yersinia Pestis Virulence Factor Yfea Reveals Two Polyspecific Metal-Binding Sites, Christopher D. Radka, Lawrence J. Delucas, Landon S. Wilson, Matthew B. Lawrenz, Robert D. Perry, Stephen G. Aller

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Gram-negative bacteria use siderophores, outer membrane receptors, inner membrane transporters and substrate-binding proteins (SBPs) to transport transition metals through the periplasm. The SBPs share a similar protein fold that has undergone significant structural evolution to communicate with a variety of differentially regulated transporters in the cell. In Yersinia pestis, the causative agent of plague, YfeA (YPO2439, y1897), an SBP, is important for full virulence during mammalian infection. To better understand the role of YfeA in infection, crystal structures were determined under several environmental conditions with respect to transition-metal levels. Energy-dispersive X-ray spectroscopy and anomalous X-ray scattering data show that …

Zinc Transporters Ybtx And Znuabc Are Required For The Virulence Of Yersinia Pestis In Bubonic And Pneumonic Plague In Mice, Alexander G. Bobrov, Olga Kirillina, Marina Y. Fosso, Jacqueline D. Fetherston, M. Clarke Miller, Tiva T. Vancleave, Joseph A. Burlison, William K. Arnold, Matthew B. Lawrenz, Sylvie Garneau-Tsodikova, Robert D. Perry

Microbiology, Immunology, and Molecular Genetics Faculty Publications

A number of bacterial pathogens require the ZnuABC Zinc (Zn²⁺) transporter and/or a second Zn²⁺ transport system to overcome Zn²⁺ sequestration by mammalian hosts. Previously we have shown that in addition to ZnuABC, Yersinia pestis possesses a second Zn²⁺ transporter that involves components of the yersiniabactin (Ybt), siderophore-dependent iron transport system. Synthesis of the Ybt siderophore and YbtX, a member of the major facilitator superfamily, are both critical components of the second Zn²⁺ transport system. Here we demonstrate that a ybtX znu double mutant is essentially avirulent in mouse models of bubonic and pneumonic …

Genome- And Cd4+ T-Cell Methylome-Wide Association Study Of Circulating Trimethylamine-N-Oxide In The Genetics Of Lipid Lowering Drugs And Diet Network (Goldn), Stella Aslibekyan, Marguerite R. Irvin, Bertha A. Hidalgo, Rodney T. Perry, Elias J. Jeyarajah, Erwin Garcia, Irina Shalaurova, Paul N. Hopkins, Michael A. Province, Hemant K. Tiwari, Jose M. Ordovas, Devin M. Absher, Donna K. Arnett

Epidemiology and Environmental Health Faculty Publications

Background: Trimethylamine-N-oxide (TMAO), an atherogenic metabolite species, has emerged as a possible new risk factor for cardiovascular disease. Animal studies have shown that circulating TMAO levels are regulated by genetic and environmental factors. However, large-scale human studies have failed to replicate the observed genetic associations, and epigenetic factors such as DNA methylation have never been examined in relation to TMAO levels.

Methods and results: We used data from the family-based Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) to investigate the heritable determinants of plasma TMAO in humans. TMAO was not associated with other plasma markers of cardiovascular disease, …

Overcoming Hurdles To Development Of A Vaccine Against Pneumocystis Jirovecii, Beth A. Garvy

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Development of Pneumocystis pneumonia (PCP) is a common problem among immunosuppressed individuals. There are windows of opportunity in which vaccination would be beneficial, but to date, no vaccines have made it to clinical trials. Significant hurdles to vaccine development include host range specificity, making it difficult to translate from animal models to humans. Discovery of cross-reactive epitopes is critical to moving vaccine candidates from preclinical animal studies to clinical trials.

Csf Protein Changes Associated With Hippocampal Sclerosis Risk Gene Variants Highlight Impact Of Grn/Pgrn, David W. Fardo, Yuriko Katsumata, John S. K. Kauwe, Yuetiva Deming, Oscar Harari, Carlos Cruchaga, Alzheimer’S Disease Neuroimaging Initiative, Peter T. Nelson

Sanders-Brown Center on Aging Faculty Publications

Objective—Hippocampal sclerosis of aging (HS-Aging) is a common cause of dementia in older adults. We tested the variability in cerebrospinal fluid (CSF) proteins associated with previously identified HS-Aging risk single nucleotide polymorphisms (SNPs).

Methods—Alzheimer’s Disease Neuroimaging Initiative cohort (ADNI; n=237) data, combining both multiplexed proteomics CSF and genotype data, were used to assess the association between CSF analytes and risk SNPs in four genes (SNPs): GRN (rs5848), TMEM106B (rs1990622), ABCC9 (rs704180), and KCNMB2 (rs9637454). For controls, non-HS-Aging SNPs in APOE (rs429358/rs7412) and MAPT (rs8070723) were also analyzed against Aβ1-42 and total tau CSF analytes.

Results—The GRN risk …

Latexin Inactivation Enhances Survival And Long-Term Engraftment Of Hematopoietic Stem Cells And Expands The Entire Hematopoietic System In Mice, Yi Liu, Cuiping Zhang, Zhenyu Li, Chi Wang, Jianhang Jia, Tianyan Gao, Gerhard C. Hildebrandt, Daohong Zhou, Subbarao Bondada, Peng Ji, Daret K. St. Clair, Jinze Liu, Chang-Guo Zhan, Hartmut Geiger, Shuxia Wang, Ying Liang

Toxicology and Cancer Biology Faculty Publications

Natural genetic diversity offers an important yet largely untapped resource to decipher the molecular mechanisms regulating hematopoietic stem cell (HSC) function. Latexin (Lxn) is a negative stem cell regulatory gene identified on the basis of genetic diversity. By using an Lxn knockout mouse model, we found that Lxn inactivation in vivo led to the physiological expansion of the entire hematopoietic hierarchy. Loss of Lxn enhanced the competitive repopulation capacity and survival of HSCs in a cell-intrinsic manner. Gene profiling of Lxn-null HSCs showed altered expression of genes enriched in cell-matrix and cell-cell interactions. Thrombospondin 1 (Thbs1 …

Cpt1a Methylation Is Associated With Plasma Adiponectin, S. Aslibekyan, A. N. Do, H. Xu, S. Li, M. R. Irvin, D Zhi, H. K. Tiwari, D. M. Absher, A. R. Shuldiner, T. Zhang, W. Chen, K. Tanner, C. Hong, B. D. Mitchell, G. Berenson, Donna K. Arnett

Epidemiology and Environmental Health Faculty Publications

Background and Aims—Adiponectin, an adipose-secreted protein that has been linked to insulin sensitivity, plasma lipids, and inflammatory patterns, is an established biomarker for metabolic health. Despite clinical relevance and high heritability, the determinants of plasma adiponectin levels remain poorly understood.

Methods and Results—We conducted the first epigenome-wide cross-sectional study of adiponectin levels using methylation data on 368,051 cytosine-phosphate-guanine (CpG) sites in CD4+ T-cells from the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN, n= 991). We fit linear mixed models, adjusting for age, sex, study site, T-cell purity, and family. We have identified a positive association (regression …

Pneumocystis Infection Alters The Activation State Of Pulmonary Macrophages, Jessica M. Deckman, Cathryn J. Kurkjian, Joseph P. Mcgillis, Theodore J. Cory, Susan E. Birket, Linda M. Schutzman, Brian S. Murphy, Beth A. Garvy, David J. Feola

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Recent studies show a substantial incidence of Pneumocystis jirovecii colonization and infection in patients with chronic inflammatory lung conditions. However, little is known about the impact of Pneumocystis upon the regulation of pulmonary immunity. We demonstrate here that Pneumocystis polarizes macrophages towards an alternatively activated macrophage-like phenotype. Genetically engineered mice that lack the ability to signal through IL-4 and IL-13 were used to show that Pneumocystis alternative macrophage activation is dependent upon signaling through these cytokines. To determine whether Pneumocystis-induced macrophage polarization would impact subsequent immune responses, we infected mice with Pneumocystis and then challenged them with Pseudomonas aeruginosa 14 …

Inhibition Of The Integrin/Fak Signaling Axis And C-Myc Synergistically Disrupts Ovarian Cancer Malignancy, B. Xu, Jason R. Lefringhouse, Z. Liu, D. West, Lauren A. Baldwin, C. Ou, L. Chen, Dana L. Napier, Luksana Chaiswing, Lawrence D. Brewer, Daret K. St Clair, Olivier Thibault, John R. Van Nagell, Binhua P. Zhou, R. Drapkin, J.-A. Huang, M. L. Lu, Frederick R. Ueland, X. H. Yang

Pharmacology and Nutritional Sciences Faculty Publications

Integrins, a family of heterodimeric receptors for extracellular matrix, are promising therapeutic targets for ovarian cancer, particularly high-grade serous-type (HGSOC), as they drive tumor cell attachment, migration, proliferation and survival by activating focal adhesion kinase (FAK)-dependent signaling. Owing to the potential off-target effects of FAK inhibitors, disruption of the integrin signaling axis remains to be a challenge. Here, we tackled this barrier by screening for inhibitors being functionally cooperative with small-molecule VS-6063, a phase II FAK inhibitor. From this screening, JQ1, a potent inhibitor of Myc oncogenic network, emerged as the most robust collaborator. Treatment with a combination of VS-6063 …

Radiation Induced Apoptosis Of Murine Bone Marrow Cells Is Independent Of Early Growth Response 1 (Egr1), Karine Z. Oben, Beth W. Gachuki, Sara S. Alhakeem, Mary Kathryn Mckenna, Ying Liang, Daret K. St. Clair, Vivek M. Rangnekar, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

An understanding of how each individual 5q chromosome critical deleted region (CDR) gene contributes to malignant transformation would foster the development of much needed targeted therapies for the treatment of therapy related myeloid neoplasms (t-MNs). Early Growth Response 1 (EGR1) is a key transcriptional regulator of myeloid differentiation located within the 5q chromosome CDR that has been shown to regulate HSC (hematopoietic stem cell) quiescence as well as the master regulator of apoptosis—p53. Since resistance to apoptosis is a hallmark of malignant transformation, we investigated the role of EGR1 in apoptosis of bone marrow cells; a cell population from which …