Medical Microbiology Commons^™

Inactivation Of The Fusobacterium Nucleatum Rnf Complex Reduces Fada-Mediated Amyloid Formation And Tumor Development, Timmie A Britton, Ju Huck Lee, Chungyu Chang, Aadil H Bhat, Yi-Wei Chen, Rusul Mohammed Ali, Chenggang Wu, Asis Das, Hung Ton-That

Faculty, Staff and Student Publications

The Gram-negative anaerobe Fusobacterium nucleatum is an oral oncobacterium that promotes colorectal cancer (CRC) development with the amyloid-forming cell surface adhesin FadA integral to CRC tumorigenesis. We describe here molecular genetic studies uncovering a novel mode of metabolic regulation of FadA-mediated tumor formation by a highly conserved respiratory enzyme known as the Rnf complex. First, we show that genetic disruption of Rnf, via rnfC deletion, significantly reduces the level of fadA transcript, accompanied by a near-complete abolishment of the precursor form of FadA (pFadA), reduced assembly of FadA at the mature cell pole, and severe defects in the osmotic stress-induced …

Staphylococcus Aureus Encodes Four Differentially Regulated Pyruvate Transporters, Jennifer L. Endres, Cleofes Sarmiento, William Xiao, Marat R. Sadykov, Kenneth W. Bayles, Mckenzie K. Lehman

Journal Articles: Pathology and Microbiology

The success of Staphylococcus aureus as a pathogen is attributable, in part, to its ability to exploit the diverse nutrient sources available during infection. Critical to this success are the pathways involving pyruvate that serve as a nexus for energy production, oxidative metabolism, and biosynthetic processes. When available, bacteria acquire pyruvate from the environment to fuel growth. Recently, LrgAB was identified as a pyruvate transporter under microaerobic conditions, leading us to speculate that S. aureus encodes other pyruvate transporters that are active during aerobic growth. In this study, we used the toxic pyruvate analog, 3-fluoropyruvic acid (3-FP), to isolate mutants …

The Dna Demethylase Tet1 Modifies The Impact Of Maternal Folic Acid Status On Embryonic Brain Development, Lehua Chen, Bernard K Van Der Veer, Qiuying Chen, Spyridon Champeris Tsaniras, Wannes Brangers, Harm H M Kwak, Rita Khoueiry, Yunping Lei, Robert Cabrera, Steven S Gross, Richard H Finnell, Kian Peng Koh

Faculty, Staff and Students Publications

Folic acid (FA) is well known to prevent neural tube defects (NTDs), but we do not know why many human NTD cases still remain refractory to FA supplementation. Here, we investigate how the DNA demethylase TET1 interacts with maternal FA status to regulate mouse embryonic brain development. We determined that cranial NTDs display higher penetrance in non-inbred than in inbred Tet1−/− embryos and are resistant to FA supplementation across strains. Maternal diets that are either too rich or deficient in FA are linked to an increased incidence of cranial deformities in wild type and Tet1+/− offspring and to …

Nerve Injury Inhibits Oprd1 And Cnr1 Transcription Through Rest In Primary Sensory Neurons, Ashok Subedi, Asieh Etemad, Aadhya Tiwari, Yuying Huang, Biji Chatterjee, Samantha M Mcleod, Yungang Lu, Diangelo Gonzalez, Krishna Ghosh, Mario Sirito, Sanjay K Singh, Elisa Ruiz, Sandra L Grimm, Cristian Coarfa, Hui-Lin Pan, Sadhan Majumder

Faculty, Staff and Students Publications

The transcription repressor REST in the dorsal root ganglion (DRG) is upregulated by peripheral nerve injury and promotes the development of chronic pain. However, the genes targeted by REST in neuropathic pain development remain unclear. The expression levels of four opioid receptor genes (Oprm1, Oprd1, Oprl1 and Oprk1) and the cannabinoid CB1 receptor (Cnr1) gene in the DRG regulate nociception. In this study, we determined the role of REST in controlling their expression in the DRG induced by spared nerve injury (SNI). SNI induced chronic pain hypersensitivity in wild-type mice and was accompanied by increased levels of Rest transcript and …

Phenotypic Diversity Of Type Iii Secretion System Activity In Enteropathogenic Escherichia Coli Clinical Isolates, Carmen A Contreras, Tracy H Hazen, Carmen Guadarrama, Ramón Cervantes-Rivera, Theresa J Ochoa, Pablo Vinuesa, David A Rasko, Jose L Puente

Faculty, Staff and Student Publications

Introduction. Enteropathogenic Escherichia coli (EPEC) strains pose a significant threat as a leading cause of severe childhood diarrhoea in developing nations. EPEC pathogenicity relies on the type III secretion system (T3SS) encoded by the locus of enterocyte effacement (LEE), facilitating the secretion and translocation of bacterial effector proteins.

Gap Statement. While the regulatory roles of PerC (plasmid-encoded regulator) and GrlA (global regulator of LEE-activator) in ler expression and LEE gene activation are well-documented in the EPEC prototype strain E2348/69, understanding the variability in LEE gene expression control mechanisms among clinical EPEC isolates remains an area requiring further investigation.

Aim. This …

The Kat Module Of The Saga Complex Maintains The Oncogenic Gene Expression Program In Mycn- Amplified Neuroblastoma, Clare F Malone, Nathaniel W Mabe, Alexandra B Forman, Gabriela Alexe, Kathleen L Engel, Ying-Jiun C Chen, Melinda Soeung, Silvi Salhotra, Allen Basanthakumar, Bin Liu, Sharon Y R Dent, Kimberly Stegmaier

Faculty, Staff and Student Publications

Pediatric cancers are frequently driven by genomic alterations that result in aberrant transcription factor activity. Here, we used functional genomic screens to identify multiple genes within the transcriptional coactivator Spt-Ada-Gcn5-acetyltransferase (SAGA) complex as selective dependencies for MYCN-amplified neuroblastoma, a disease of dysregulated development driven by an aberrant oncogenic transcriptional program. We characterized the DNA recruitment sites of the SAGA complex in neuroblastoma and the consequences of loss of SAGA complex lysine acetyltransferase (KAT) activity on histone acetylation and gene expression. We demonstrate that loss of SAGA complex KAT activity is associated with reduced MYCN binding on chromatin, suppression of …

Bacterial Single-Cell Rna Sequencing Captures Biofilm Transcriptional Heterogeneity And Differential Responses To Immune Pressure, Lee E. Korshoj, Tammy Kielian

Journal Articles: Pathology and Microbiology

Biofilm formation is an important mechanism of survival and persistence for many bacterial pathogens. These multicellular communities contain subpopulations of cells that display metabolic and transcriptional diversity along with recalcitrance to antibiotics and host immune defenses. Here, we present an optimized bacterial single-cell RNA sequencing method, BaSSSh-seq, to study Staphylococcus aureus diversity during biofilm growth and transcriptional adaptations following immune cell exposure. BaSSSh-seq captures extensive transcriptional heterogeneity during biofilm compared to planktonic growth. We quantify and visualize transcriptional regulatory networks across heterogeneous biofilm subpopulations and identify gene sets that are associated with a trajectory from planktonic to biofilm growth. BaSSSh-seq …

Gene Transcription Regulation By Er At The Single Cell And Allele Level, Fabio Stossi, Alejandra Rivera Tostado, Hannah L Johnson, Ragini M Mistry, Maureen G Mancini, Michael A Mancini

Faculty, Staff and Students Publications

In this short review we discuss the current view of how the estrogen receptor (ER), a pivotal member of the nuclear receptor superfamily of transcription factors, regulates gene transcription at the single cell and allele level, focusing on in vitro cell line models. We discuss central topics and new trends in molecular biology including phenotypic heterogeneity, single cell sequencing, nuclear phase separated condensates, single cell imaging, and image analysis methods, with particular focus on the methodologies and results that have been reported in the last few years using microscopy-based techniques. These observations augment the results from biochemical assays that lead …

Targeted Inhibition Of Lncrna Malat1 Alters The Tumor Immune Microenvironment In Preclinical Syngeneic Mouse Models Of Triple-Negative Breast Cancer, Oluwatoyosi Adewunmi, Yichao Shen, Xiang H-F Zhang, Jeffrey M Rosen

Faculty, Staff and Students Publications

Long noncoding RNAs (lncRNA) play an important role in gene regulation in both normal tissues and cancer. Targeting lncRNAs is a promising therapeutic approach that has become feasible through the development of gapmer antisense oligonucleotides (ASO). Metastasis-associated lung adenocarcinoma transcript (Malat1) is an abundant lncRNA whose expression is upregulated in several cancers. Although Malat1 increases the migratory and invasive properties of tumor cells, its role in the tumor microenvironment (TME) is still not well defined. We explored the connection between Malat1 and the tumor immune microenvironment (TIME) using several immune-competent preclinical syngeneic Tp53-null triple-negative breast cancer (TNBC) mouse models that …

Traf4-Mediated Nonproteolytic Ubiquitination Of Androgen Receptor Promotes Castration-Resistant Prostate Cancer, Ramesh Singh, Huan Meng, Tao Shen, Lance Edward V Lumahan, Steven Nguyen, Hong Shen, Subhamoy Dasgupta, Li Qin, Dileep Karri, Bokai Zhu, Feng Yang, Cristian Coarfa, Bert W O'Malley, Ping Yi

Faculty, Staff and Students Publications

Castration-resistant prostate cancer (CRPC) poses a major clinical challenge with the androgen receptor (AR) remaining to be a critical oncogenic player. Several lines of evidence indicate that AR induces a distinct transcriptional program after androgen deprivation in CRPCs. However, the mechanism triggering AR binding to a distinct set of genomic loci in CRPC and how it promotes CRPC development remain unclear. We demonstrate here that atypical ubiquitination of AR mediated by an E3 ubiquitin ligase TRAF4 plays an important role in this process. TRAF4 is highly expressed in CRPCs and promotes CRPC development. It mediates K27-linked ubiquitination at the C-terminal …

Hemato-Vascular Specification Requires Arnt1 And Arnt2 Genes In Zebrafish Embryos, Hailey E Edwards, Mary Jane Elizalde, Jaclyn P Souder, Daniel A Gorelick

Faculty, Staff and Students Publications

During embryonic development, a subset of cells in the mesoderm germ layer are specified as hemato-vascular progenitor cells, which then differentiate into endothelial cells and hematopoietic stem and progenitor cells. In zebrafish, the transcription factor npas4l (cloche) is required for the specification of hemato-vascular progenitor cells. However, it is unclear whether npas4l is the sole factor at the top of the hemato-vascular specification cascade. Here, we show that arnt1 and arnt2 genes are required for hemato-vascular specification. We found that arnt1;arnt2 double mutant zebrafish embryos, but not arnt1 or arnt2 single mutants, lack blood cells and most endothelial cells. arnt1/2 …

The Tfiis N-Terminal Domain (Tnd): A Transcription Assembly Module At The Interface Of Order And Disorder, Katerina Cermakova, Vaclav Veverka, H Courtney Hodges

Faculty, Staff and Students Publications

Interaction scaffolds that selectively recognize disordered protein strongly shape protein interactomes. An important scaffold of this type that contributes to transcription is the TFIIS N-terminal domain (TND). The TND is a five-helical bundle that has no known enzymatic activity, but instead selectively reads intrinsically disordered sequences of other proteins. Here, we review the structural and functional properties of TNDs and their cognate disordered ligands known as TND-interacting motifs (TIMs). TNDs or TIMs are found in prominent members of the transcription machinery, including TFIIS, super elongation complex, SWI/SNF, Mediator, IWS1, SPT6, PP1-PNUTS phosphatase, elongin, H3K36me3 readers, the transcription factor MYC, and …

Post-Transcriptional Regulation In Cranial Neural Crest Cells Expands Developmental Potential, Rachel A Keuls, Young Sun Oh, Ivanshi Patel, Ronald J Parchem

Faculty, Staff and Students Publications

Developmental potential is progressively restricted after germ layer specification during gastrulation. However, cranial neural crest cells challenge this paradigm, as they develop from anterior ectoderm, yet give rise to both ectodermal derivatives of the peripheral nervous system and ectomesenchymal bone and cartilage. How cranial neural crest cells differentiate into multiple lineages is poorly understood. Here, we demonstrate that cranial neural crest cells possess a transient state of increased chromatin accessibility. We profile the spatiotemporal emergence of premigratory neural crest and find evidence of lineage bias toward either a neuronal or ectomesenchymal fate, with each expressing distinct factors from earlier stages …

Enhancer-Promoter Entanglement Explains Their Transcriptional Interdependence, Anil K Panigrahi, David M Lonard, Bert W O'Malley

Faculty, Staff and Students Publications

Enhancers not only activate target promoters to stimulate messenger RNA (mRNA) synthesis, but they themselves also undergo transcription to produce enhancer RNAs (eRNAs), the significance of which is not well understood. Transcription at the participating enhancer-promoter pair appears coordinated, but it is unclear why and how. Here, we employ cell-free transcription assays using constructs derived from the human GREB1 locus to demonstrate that transcription at an enhancer and its target promoter is interdependent. This interdependence is observable under conditions where direct enhancer-promoter contact (EPC) takes place. We demonstrate that transcription activation at a participating enhancer-promoter pair is dependent on i) …

The Temporal Impulse Response Function In Infantile Nystagmus, Gal Avital, Felicia Kuperwaser, Andrew W Pountain, Keenan A Lacey, Erin E Zwack, Magdalena Podkowik, Bo Shopsin, Victor J Torres, Itai Yanai

Faculty, Staff and Student Publications

Innate immune recognition of bacterial pathogens is a key determinant of the ensuing systemic response, and host or pathogen heterogeneity in this early interaction can impact the course of infection. To gain insight into host response heterogeneity, we investigate macrophage inflammatory dynamics using primary human macrophages infected with Group B Streptococcus. Transcriptomic analysis reveals discrete cellular states within responding macrophages, one of which consists of four sub-states, reflecting inflammatory activation. Infection with six additional bacterial species—Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis, Yersinia pseudotuberculosis, Shigella flexneri, and Salmonella enterica—recapitulates these states, though at …

Mir-181a Promotes Multiple Protumorigenic Functions By Targeting Tgfβr3, Vida Chitsazzadeh, Tran N Nguyen, Alvaro De Mingo Pulido, Bruna B Bittencourt, Lili Du, Charles H Adelmann, Ivannie Ortiz Rivera, Kimberly A Nguyen, Leah D Guerra, Andrew Davis, Marco Napoli, Wencai Ma, Richard Eric Davis, Kimal Rajapakshe, Cristian Coarfa, Elsa R Flores, Kenneth Y Tsai

Faculty, Staff and Students Publications

Cutaneous squamous cell carcinoma (cSCC) comprises 15‒20% of all skin cancers and has a well-defined progression sequence from precancerous actinic keratosis to invasive cSCC. To identify targets for chemoprevention, we previously reported a cross-species analysis to identify the transcriptional drivers of cSCC development and identified miR-181a as a potential oncomiR. We show that the upregulation of miR-181a promotes multiple protumorigenic properties by targeting an understudied component of TGFβ signaling, TGFβR3. miR-181a and TGFβR3 are upregulated and downregulated, respectively, in cSCC. miR-181a overexpression (OE) and TGFβR3 knockdown (KD) significantly suppresses UV-induced apoptosis in HaCaT cells and in primary normal human epidermal …

Δnp63 Regulates A Common Landscape Of Enhancer Associated Genes In Non-Small Cell Lung Cancer, Marco Napoli, Sarah J Wu, Bethanie L Gore, Hussein A Abbas, Kyubum Lee, Rahul Checker, Shilpa Dhar, Kimal Rajapakshe, Aik Choon Tan, Min Gyu Lee, Cristian Coarfa, Elsa R Flores

Faculty, Staff and Students Publications

Distinct lung stem cells give rise to lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC). ΔNp63, the p53 family member and p63 isoform, guides the maturation of these stem cells through the regulation of their self-renewal and terminal differentiation; however, the underlying mechanistic role regulated by ∆Np63 in lung cancer development has remained elusive. By utilizing a ΔNp63-specific conditional knockout mouse model and xenograft models of LUAD and LUSC, we found that ∆Np63 promotes non-small cell lung cancer by maintaining the lung stem cells necessary for lung cancer cell initiation and progression in quiescence. ChIP-seq analysis of lung basal cells, …

Identification Of Serum Mirna Signature And Establishment Of A Nomogram For Risk Stratification In Patients With Pancreatic Ductal Adenocarcinoma, Raju Kandimalla, Tadanobu Shimura, Saurav Mallik, Fuminori Sonohara, Susan Tsai, Douglas B Evans, Song Cheol Kim, Hideo Baba, Yasuhiro Kodera, Daniel Von Hoff, Xi Chen, Ajay Goel

Faculty, Staff and Students Publications

OBJECTIVE: The aim of the study was to perform mRNA-miRNA regulatory network analyses to identify a miRNA panel for molecular subtype identification and stratification of high-risk patients with pancreatic ductal adenocarcinoma (PDAC).

BACKGROUND: Recent transcriptional profiling effort in PDAC has led to the identification of molecular subtypes that associate with poor survival; however, their clinical significance for risk stratification in patients with PDAC has been challenging.

METHODS: By performing a systematic analysis in The Cancer Genome Atlas and International Cancer Genome Consortium cohorts, we discovered a panel of miRNAs that associated with squamous and other poor molecular subtypes in PDAC. …

Interleukin-10 Suppression Enhances T-Cell Antitumor Immunity And Responses To Checkpoint Blockade In Chronic Lymphocytic Leukemia., J R Rivas, Y Liu, S S Alhakeem, J M Eckenrode, F Marti, J P Collard, Y Zhang, K A Shaaban, N Muthusamy, G C Hildebrandt, L Chen, J S Thorson, M Leggas, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

T-cell dysfunction is a hallmark of B-cell Chronic Lymphocytic Leukemia (CLL), where CLL cells downregulate T-cell responses through regulatory molecules including programmed death ligand-1 (PD-L1) and Interleukin-10 (IL-10). Immune checkpoint blockade (ICB) aims to restore T-cell function by preventing the ligation of inhibitory receptors like PD-1. However, most CLL patients do not respond well to this therapy. Thus, we investigated whether IL-10 suppression could enhance antitumor T-cell activity and responses to ICB. Since CLL IL-10 expression depends on Sp1, we utilized a novel, better tolerated analogue of the Sp1 inhibitor mithramycin (MTM

In Vivo Transplantation Of Human Intestinal Organoids Enhances Select Tight Junction Gene Expression, Mariaelena A Boyle, David J Sequeira, Eoin P Mcneill, Zachary K Criss, Noah F Shroyer, Allison L Speer

Faculty, Staff and Student Publications

BACKGROUND: Short bowel syndrome is a potentially fatal condition with inadequate management options. Tissue-engineered small intestine (TESI) is a promising solution, but confirmation of TESI function will be crucial before human application. We sought to define intestinal epithelial barrier function in human intestinal organoid (HIO)-derived TESI.

MATERIALS AND METHODS: HIOs were generated in vitro from human embryonic stem cells. After 1 mo, HIOs were collected for analysis or transplanted into the kidney capsule of immunocompromised mice. Transplanted HIOs (tHIOs) were harvested for analysis at 4 or 8 wk. Reverse transcription quantitative polymerase chain reaction and immunofluorescent staining were performed for …

The Trophic Life Cycle Stage Of The Opportunistic Fungal Pathogen Pneumocystis Murina Hinders The Ability Of Dendritic Cells To Stimulate Cd4+ T Cell Responses, Heather M. Evans, Andrew Simpson, Shu Shen, Arnold J. Stromberg, Carol L. Pickett, Beth A. Garvy

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The life cycle of the opportunistic fungal pathogen Pneumocystis murina consists of a trophic stage and an ascus-like cystic stage. Infection with the cyst stage induces proinflammatory immune responses, while trophic forms suppress the cytokine response to multiple pathogen-associated molecular patterns (PAMPs), including β-glucan. A targeted gene expression assay was used to evaluate the dendritic cell response following stimulation with trophic forms alone, with a normal mixture of trophic forms and cysts, or with β-glucan. We demonstrate that stimulation with trophic forms downregulated the expression of multiple genes normally associated with the response to infection, including genes encoding …

Apparent Role For Borrelia Burgdorferi Luxs During Mammalian Infection, William K. Arnold, Christina R. Savage, Alyssa D. Antonicello, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Lyme disease spirochete, Borrelia burgdorferi, controls protein expression patterns during its tick-mammal infection cycle. Earlier studies demonstrated that B. burgdorferi synthesizes 4,5-dihydroxy-2,3-pentanedione (autoinducer-2 [AI-2]) and responds to AI-2 by measurably changing production of several infection-associated proteins. luxS mutants, which are unable to produce AI-2, exhibit altered production of several proteins. B. burgdorferi cannot utilize the other product of LuxS, homocysteine, indicating that phenotypes of luxS mutants are not due to the absence of that molecule. Although a previous study found that a luxS mutant was capable of infecting mice, a critical caveat to those results is that bacterial …

Vaccination With A Genetically Modified Brugia Malayi Cysteine Protease Inhibitor-2 Reduces Adult Parasite Numbers And Affects The Fertility Of Female Worms Following A Subcutaneous Challenge Of Mongolian Gerbils (Meriones Unguiculatus) With B. Malayi Infective Larvae., Sridhar Arumugam, Junfei Wei, Danielle Ward, David Abraham, Sara Lustigman, Bin Zhan, Thomas R. Klei

Department of Microbiology and Immunology Faculty Papers

Vaccination of Mongolian gerbils with Brugia malayi cysteine protease inhibitor-2 in which the amino acid Asn66 was mutated to Lys66 (Bm-CPI-2M) resulted in reduced parasite numbers of 48.6% and 48.0% at 42 and 90 days p.i. with B. malayi L3s. Fertility of female worms was also affected at 90 days p.i. In vitro killing of L3s observed in the presence of gerbil peritoneal exudate cells and anti-Bm-CPI-2M sera suggests antibody-dependent cell-mediated cytotoxicity as a putative protective mechanism. These observations suggest that Bm-CPI-2M is a promising prophylactic and anti-fecundity vaccine candidate.

Cyclic Di-Gmp-Dependent Signaling Pathways In The Pathogenic Firmicute Listeria Monocytogenes, Li-Hong Chen, Volkan K. Köseoğlu, Zehra T. Güvener, Tanya Myers-Morales, Joseph M. Reed, Sarah E. F. D'Orazio, Kurt W. Miller, Mark Gomelsky

Microbiology, Immunology, and Molecular Genetics Faculty Publications

We characterized key components and major targets of the c-di-GMP signaling pathways in the foodborne pathogen Listeria monocytogenes, identified a new c-di-GMP-inducible exopolysaccharide responsible for motility inhibition, cell aggregation, and enhanced tolerance to disinfectants and desiccation, and provided first insights into the role of c-di-GMP signaling in listerial virulence. Genome-wide genetic and biochemical analyses of c-di-GMP signaling pathways revealed that L. monocytogenes has three GGDEF domain proteins, DgcA (Lmo1911), DgcB (Lmo1912) and DgcC (Lmo2174), that possess diguanylate cyclase activity, and three EAL domain proteins, PdeB (Lmo0131), PdeC (Lmo1914) and PdeD (Lmo0111), that possess c-di-GMP phosphodiesterase activity. Deletion of all …

Vcam-1/Α4Β1 Integrin Interaction Is Crucial For Prompt Recruitment Of Immune T Cells Into The Brain During The Early Stage Of Reactivation Of Chronic Infection With Toxoplasma Gondii To Prevent Toxoplasmic Encephalitis, Qila Sa, Eri Ochiai, Tomoko Sengoku, Melinda E. Wilson, Morgan Brogli, Stephen Crutcher, Sara A. Michie, Baohui Xu, Laura Payne, Xisheng Wang, Yasuhiro Suzuki

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Reactivation of chronic infection with Toxoplasma gondii can cause life-threatening toxoplasmic encephalitis in immunocompromised individuals. We examined the role of VCAM-1/α4β1 integrin interaction in T cell recruitment to prevent reactivation of the infection in the brain. SCID mice were infected and treated with sulfadiazine to establish a chronic infection. VCAM-1 and ICAM-1 were the endothelial adhesion molecules detected on cerebral vessels of the infected SCID and wild-type animals. Immune T cells from infected wild-type mice were treated with anti-α4 integrin or control antibodies and transferred into infected SCID or nude mice, and the animals received the same antibody every other …

A Central Role For Carbon-Overflow Pathways In The Modulation Of Bacterial Cell Death., Vinai Chittezham Thomas, Marat Sadykov, Sujata S. Chaudhari, Joselyn Jones, Jennifer L. Endres, Todd J. Widhelm, Jong-Sam Ahn, Randeep S. Jawa, Matthew C. Zimmerman, Kenneth W. Bayles

Journal Articles: Pathology and Microbiology

Similar to developmental programs in eukaryotes, the death of a subpopulation of cells is thought to benefit bacterial biofilm development. However mechanisms that mediate a tight control over cell death are not clearly understood at the population level. Here we reveal that CidR dependent pyruvate oxidase (CidC) and α-acetolactate synthase/decarboxylase (AlsSD) overflow metabolic pathways, which are active during staphylococcal biofilm development, modulate cell death to achieve optimal biofilm biomass. Whereas acetate derived from CidC activity potentiates cell death in cells by a mechanism dependent on intracellular acidification and respiratory inhibition, AlsSD activity effectively counters CidC action by diverting carbon flux …

Functional Proteomic Analysis Reveals The Involvement Of Kiaa1199 In Breast Cancer Growth, Motility And Invasiveness., Mohammad-Saeid Jami, Jinxuan Hou, Miao Liu, M L. Varney, Hesham Hassan, Jixin Dong, Liying Geng, J. Wang, Fang Yu, Xin Huang, Hong Peng, Kai Fu, Yan Li, Rakesh Singh, Shi-Jian Ding

Journal Articles: Pathology and Microbiology

BACKGROUND: KIAA1199 is a recently identified novel gene that is up-regulated in human cancer with poor survival. Our proteomic study on signaling polarity in chemotactic cells revealed KIAA1199 as a novel protein target that may be involved in cellular chemotaxis and motility. In the present study, we examined the functional significance of KIAA1199 expression in breast cancer growth, motility and invasiveness.

METHODS: We validated the previous microarray observation by tissue microarray immunohistochemistry using a TMA slide containing 12 breast tumor tissue cores and 12 corresponding normal tissues. We performed the shRNA-mediated knockdown of KIAA1199 in MDA-MB-231 and HS578T cells to …

Septins Of Platyhelminths: Identification, Phylogeny, Expression And Localization Among Developmental Stages Of Schistosoma Mansoni, Ana E. Zeraik, Gabriel Rinaldi, Victoria H. Mann, Anastas Popratiloff, Ana P.U. Araujo, Ricardo Demarco, Paul J. Brindley

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Septins are a family of eukaryotic GTP binding proteins conserved from yeasts to humans. Originally identified in mutants of budding yeast, septins participate in diverse cellular functions including cytokinesis, organization of actin networks, cell polarity, vesicle trafficking and many others. Septins assemble into heteroligomers to form filaments and rings. Here, four septins of Schistosoma mansoni are described, which appear to be conserved within the phylum Platyhelminthes. These orthologues were related to the SEPT5, SEPT10 and SEPT7 septins of humans, and hence we have termed the schistosome septins SmSEPT5, SmSEPT10, SmSEPT7.1 and SmSEPT7.2. Septin transcripts were detected throughout the developmental cycle …

Gene Expression Analysis Of A Murine Model With Pulmonary Vascular Remodeling Compared To End-Stage Ipah Lungs, Kayoko Shimodaira, Yoichiro Okubo, Eri Ochiai, Haruo Nakayama, Harutaka Katano, Megumi Wakayama, Minoru Shinozaki, Takao Ishiwatari, Daisuke Sasai, Naobumi Tochigi, Tetsuo Nemoto, Tsutomu Saji, Katsuhiko Kamei, Kazutoshi Shibuya

Microbiology, Immunology, and Molecular Genetics Faculty Publications

BACKGROUND: Idiopathic pulmonary arterial hypertension (IPAH) continues to be one of the most serious intractable diseases that might start with activation of several triggers representing the genetic susceptibility of a patient. To elucidate what essentially contributes to the onset and progression of IPAH, we investigated factors playing an important role in IPAH by searching discrepant or controversial expression patterns between our murine model and those previously published for human IPAH. We employed the mouse model, which induced muscularization of pulmonary artery leading to hypertension by repeated intratracheal injection of Stachybotrys chartarum, a member of nonpathogenic and ubiquitous fungus in our …

Latexin Is Down-Regulated In Hematopoietic Malignancies And Restoration Of Expression Inhibits Lymphoma Growth, Yi Liu, Dianna Howard, Kyle Rector, Carol Swiderski, Jason Brandon, Lawrence Schook, Jayesh Mehta, J. Scott Bryson, Subbarao Bondada, Ying Liang

Internal Medicine Faculty Publications

Latexin is a negative regulator of hematopoietic stem cell number in mice. Its dysregulated expression in other tumors led us to hypothesize that latexin may have tumor suppressor properties in hematological malignancies. We found that latexin was down-regulated in a variety of leukemia and lymphoma cell lines as well as in CD34+ cells from the blood and marrow of patients with these malignancies. 5-aza-2'-deoxycytodine treatment and bisulfite sequencing revealed hypermethylation of latexin promoter in tumor cells. Retrovirus-mediated latexin overexpression in A20 mouse lymphoma cells inhibited their in vitro growth by 16 fold and in vivo tumor volume by 2 fold. …