Medical Sciences Commons^™

Relative Contributions Of Enterococcus Faecalis Og1rf Sortase-Encoding Genes, Srta And Bps (Srtc), To Biofilm Formation And A Murine Model Of Urinary Tract Infection, Kelvin D Kemp, Kavindra V Singh, Sreedhar R Nallapareddy, Barbara E Murray

Journal Articles

Deletion mutants of the two sortase genes of Enterococcus faecalis OG1RF were constructed. srtC (renamed here bps for biofilm and pilus-associated sortase) was previously shown to be necessary for the production of Ebp pili and important for biofilm formation and endocarditis. Here, we report that a srtA deletion mutant showed a small (5%) yet significant (P = 0.037) reduction in biofilm relative to OG1RF, while a DeltasrtA Deltabps double mutant showed a much greater reduction (74% versus OG1RF and 44% versus the Deltabps mutant). In a murine urinary tract infection (UTI), the 50% infective doses of both the DeltasrtA Deltabps …

Computational Identification And Functional Validation Of Regulatory Motifs In Cartilage-Expressed Genes, Sherri R Davies, Li-Wei Chang, Debabrata Patra, Xiaoyun Xing, Karen Posey, Jacqueline Hecht, Gary D Stormo, Linda J Sandell

Journal Articles

Chondrocyte gene regulation is important for the generation and maintenance of cartilage tissues. Several regulatory factors have been identified that play a role in chondrogenesis, including the positive transacting factors of the SOX family such as SOX9, SOX5, and SOX6, as well as negative transacting factors such as C/EBP and delta EF1. However, a complete understanding of the intricate regulatory network that governs the tissue-specific expression of cartilage genes is not yet available. We have taken a computational approach to identify cis-regulatory, transcription factor (TF) binding motifs in a set of cartilage characteristic genes to better define the transcriptional regulatory …

Energizing Mirna Research: A Review Of The Role Of Mirnas In Lipid Metabolism, With A Prediction That Mir-103/107 Regulates Human Metabolic Pathways, Bernard R. Wilfred, Wang-Xia Wang, Peter T. Nelson

Sanders-Brown Center on Aging Faculty Publications

MicroRNAs (miRNAs) are powerful regulators of gene expression. Although first discovered in worm larvae, miRNAs play fundamental biological roles-including in humans-well beyond development. MiRNAs participate in the regulation of metabolism (including lipid metabolism) for all animal species studied. A review of the fascinating and fast-growing literature on miRNA regulation of metabolism can be parsed into three main categories: (1) adipocyte biochemistry and cell fate determination; (2) regulation of metabolic biochemistry in invertebrates; and (3) regulation of metabolic biochemistry in mammals. Most research into the 'function' of a given miRNA in metabolic pathways has concentrated on a given miRNA acting upon …

The Flagellum Of Pseudomonas Aeruginosa Is Required For Resistance To Clearance By Surfactant Protein A, Shiping Zhang, Francis X. Mccormack, Roger C. Levesque, George A. O'Toole, Gee W. Lau

Dartmouth Scholarship

Surfactant protein A (SP-A) is an important lung innate immune protein that kills microbial pathogens by opsonization and membrane permeabilization. We investigated the basis of SP-A-mediated pulmonary clearance of Pseudomonas aeruginosa using genetically-engineered SP-A mice and a library of signature-tagged P. aeruginosa mutants. A mutant with an insertion into flgE, the gene that encodes flagellar hook protein, was preferentially cleared by the SP-A(+/+) mice, but survived in the SP-A(-/-) mice. Opsonization by SP-A did not play a role in flgE clearance. However, exposure to SP-A directly permeabilized and killed the flgE mutant, but not the wild-type parental strain. P. aeruginosa …

Concave Pit-Containing Scaffold Surfaces Improve Stem Cell-Derived Osteoblast Performance And Lead To Significant Bone Tissue Formation., Antonio Graziano, Riccardo D'Aquino, Maria Gabriella Cusella-De Angelis, Gregorio Laino, Adriano Piattelli, Maurizio Pacifici, Alfredo De Rosa, Gianpaolo Papaccio

Department of Orthopaedic Surgery Faculty Papers

BACKGROUND: Scaffold surface features are thought to be important regulators of stem cell performance and endurance in tissue engineering applications, but details about these fundamental aspects of stem cell biology remain largely unclear.

METHODOLOGY AND FINDINGS: In the present study, smooth clinical-grade lactide-coglyolic acid 85:15 (PLGA) scaffolds were carved as membranes and treated with NMP (N-metil-pyrrolidone) to create controlled subtractive pits or microcavities. Scanning electron and confocal microscopy revealed that the NMP-treated membranes contained: (i) large microcavities of 80-120 microm in diameter and 40-100 microm in depth, which we termed primary; and (ii) smaller microcavities of 10-20 microm in diameter …

Effects Of Low Dose Gm-Csf On Microglial Inflammatory Profiles To Diverse Pathogen-Associated Molecular Patterns (Pamps)., Nilufer Esen, Tammy Kielian

Journal Articles: Pathology and Microbiology

BACKGROUND: It is well appreciated that obtaining sufficient numbers of primary microglia for in vitro experiments has always been a challenge for scientists studying the biological properties of these cells. Supplementing culture medium with granulocyte-macrophage colony-stimulating factor (GM-CSF) partially alleviates this problem by increasing microglial yield. However, GM-CSF has also been reported to transition microglia into a dendritic cell (DC)-like phenotype and consequently, affect their immune properties.

METHODS: Although the concentration of GM-CSF used in our protocol for mouse microglial expansion (0.5 ng/ml) is at least 10-fold less compared to doses reported to affect microglial maturation and function (>/= …

The Nestin Progenitor Lineage Is The Compartment Of Origin For Pancreatic Intraepithelial Neoplasia, Catherine Carriere, Elliot S. Seeley, Tobias Goetze, Daniel S. Longnecker, Murray Korc

Dartmouth Scholarship

To determine the cell compartment in which initial oncogenic mutations occur in pancreatic ductal adenocarcinoma (PDAC), we generated a mouse model in which endogenous expression of mutated Kras (Kras(G12D)) was initially directed to a population of pancreatic exocrine progenitors characterized by the expression of Nestin. Targeting of oncogenic Kras to such a restricted cell compartment was sufficient for the formation of pancreatic intraepithelial neoplasias (PanINs), putative precursors to PDAC. PanINs appeared with the same grade and frequency as observed when Kras(G12D) was targeted to the whole pancreas by a Pdx1-driven Cre recombinase strategy. Thus, the Nestin cell lineage is highly …

Department Of Pathology, Thomas Jefferson University, Identification Of Conserved Gene Expression Features Between Murine Mammary Carcinoma Models And Human Breast Tumors., Jason I Herschkowitz, Karl Simin, Victor J Weigman, Igor Mikaelian, Jerry Usary, Zhiyuan Hu, Karen E Rasmussen, Laundette P Jones, Shahin Assefnia, Subhashini Chandrasekharan, Michael G Backlund, Yuzhi Yin, Andrey I Khramtsov, Roy Bastein, John Quackenbush, Robert I Glazer, Powel H Brown, Jeffrey E Green, Levy Kopelovich, Priscilla A Furth, Juan P Palazzo, Olufunmilayo I Olopade, Philip S Bernard, Gary A Churchill, Terry Van Dyke, Charles M Perou

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Although numerous mouse models of breast carcinomas have been developed, we do not know the extent to which any faithfully represent clinically significant human phenotypes. To address this need, we characterized mammary tumor gene expression profiles from 13 different murine models using DNA microarrays and compared the resulting data to those from human breast tumors. RESULTS: Unsupervised hierarchical clustering analysis showed that six models (TgWAP-Myc, TgMMTV-Neu, TgMMTV-PyMT, TgWAP-Int3, TgWAP-Tag, and TgC3(1)-Tag) yielded tumors with distinctive and homogeneous expression patterns within each strain. However, in each of four other models (TgWAP-T121, TgMMTV-Wnt1, Brca1Co/Co;TgMMTV-Cre;p53+/- and DMBA-induced), tumors with a variety of …