Medicine and Health Sciences Commons^™

Multiple Metabolic Hits Converge On Cd36 As Novel Mediator Of Tubular Epithelial Apoptosis In Diabetic Nephropathy., Katalin Susztak, Emilio Ciccone, Peter Mccue, Kumar Sharma, Erwin P Böttinger

Department of Medicine Faculty Papers

BACKGROUND: Diabetic nephropathy (DNP) is a common complication of type 1 and type 2 diabetes mellitus and the most common cause of kidney failure. While DNP manifests with albuminuria and diabetic glomerulopathy, its progression correlates best with tubular epithelial degeneration (TED) and interstitial fibrosis. However, mechanisms leading to TED in DNP remain poorly understood.

METHODS AND FINDINGS: We found that expression of scavenger receptor CD36 coincided with proximal tubular epithelial cell (PTEC) apoptosis and TED specifically in human DNP. High glucose stimulated cell surface expression of CD36 in PTECs. CD36 expression was necessary and sufficient to mediate PTEC apoptosis induced …

Endothelial-Specific Expression Of Caveolin-1 Impairs Microvascular Permeability And Angiogenesis, Philip M. Bauer, Jun Yu, Yan Chen, Reed Hickey, Pascal N. Bernatchez, Robin Looft-Wilson, Yan Huang, Frank Giordano, Radu V. Stan, William C. Sessa

Dartmouth Scholarship

The functions of caveolae and/or caveolins in intact animals are beginning to be explored. Here, by using endothelial cell-specific transgenesis of the caveolin-1 (Cav-1) gene in mice, we show the critical role of Cav-1 in several postnatal vascular paradigms. First, increasing levels of Cav-1 do not increase caveolae number in the endothelium in vivo. Second, despite a lack of quantitative changes in organelle number, endothelial-specific expression of Cav-1 impairs endothelial nitric oxide synthase activation, endothelial barrier function, and angiogenic responses to exogenous VEGF and tissue ischemia. In addition, VEGF-mediated phosphorylation of Akt and its substrate, endothelial nitric oxide synthase, were …

Palm Is Expressed In Both Developing And Adult Mouse Lens And Retina., Meryl Castellini, Louise V Wolf, Bharesh K Chauhan, Deni S Galileo, Manfred W Kilimann, Ales Cvekl, Melinda K Duncan

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Paralemmin (Palm) is a prenyl-palmitoyl anchored membrane protein that can drive membrane and process formation in neurons. Earlier studies have shown brain preferred Palm expression, although this protein is a major water insoluble protein in chicken lens fiber cells and the Palm gene may be regulated by Pax6. METHODS: The expression profile of Palm protein in the embryonic, newborn and adult mouse eye as well as dissociated retinal neurons was determined by confocal immunofluorescence. The relative mRNA levels of Palm, Palmdelphin (PalmD) and paralemmin2 (Palm2) in the lens and retina were determined by real time rt-PCR. RESULTS: In the …

Global Gene Expression Profiling Of Cells Overexpressing Smc3., Giancarlo Ghiselli, Chang-Gong Liu

Department of Microbiology and Immunology Faculty Papers

BACKGROUND: The Structural Maintenance of Chromosome 3 protein (SMC3) plays an essential role during the sister chromatid separation, is involved in DNA repair and recombination and participates in microtubule-mediated intracellular transport. SMC3 is frequently elevated in human colon carcinoma and overexpression of the protein transforms murine NIH3T3 fibroblasts. In order to gain insight into the mechanism of SMC3-mediated tumorigenesis a gene expression profiling was performed on human 293 cells line stably overexpressing SMC3. RESULTS: Biotinylated complementary RNA (cRNA) was used for hybridization of a cDNAmicroarray chip harboring 18,861 65-mer oligos derived from the published dEST sequences. After filtering, the hybridization …

Mitochondrial Dna Mutations, Apoptosis, And The Misfolded Protein Response., Justin L. Mott, Dekui Zhang, Hans Peter Zassenhaus

Journal Articles: Biochemistry & Molecular Biology

Studies of transgenic mice with accelerated accumulation of mtDNA mutations specifically in the heart lead us to propose that apoptotic signaling and cell death is central to the pathogenesis of mtDNA mutations in aging. It is the cellular response to that apoptotic signaling and the organ?s compensatory response to a loss of cells that specify the phenotype of an accumulation of mtDNA mutations. In the heart, cardiomyocytes induce a vigorous anti-apoptotic, pro-survival response to counteract mitochondrial apoptotic signaling. The heart up-regulates contractility of remaining myocytes in order to maintain cardiac output. We hypothesize that mutant mitochondrial proteins originate apoptotic signaling …

Prime-Boost Vaccination With Plasmid And Adenovirus Gene Vaccines Control Her2/Neu+ Metastatic Breast Cancer In Mice, Xiaoyan Wang, Jian-Ping Wang, Xiao-Mei Rao, Janet E Price, Heshan S Zhou, Lawrence B Lachman

Faculty, Staff and Student Publications

INTRODUCTION: Once metastasis has occurred, the possibility of completely curing breast cancer is unlikely, particularly for the 30 to 40% of cancers overexpressing the gene for HER2/neu. A vaccine targeting p185, the protein product of the HER2/neu gene, could have therapeutic application by controlling the growth and metastasis of highly aggressive HER2/neu+ cells. The purpose of this study was to determine the effectiveness of two gene vaccines targeting HER2/neu in preventive and therapeutic tumor models.

METHODS: The mouse breast cancer cell line A2L2, which expresses the gene for rat HER2/neu and hence p185, was injected into the mammary fat pad …

Genetic Networks Controlling Retinal Injury, Felix R Vazquez-Chona, Amna N Khan, Chun K Chan, Anthony N Moore, Pramod K Dash, M Rosario Hernandez, Lu Lu, Elissa J Chesler, Kenneth F Manly, Robert W Williams, Eldon E Geisert

Faculty, Staff and Student Publications

PURPOSE: The present study defines genomic loci underlying coordinate changes in gene expression following retinal injury.

METHODS: A group of acute phase genes expressed in diverse nervous system tissues was defined by combining microarray results from injury studies from rat retina, brain, and spinal cord. Genomic loci regulating the brain expression of acute phase genes were identified using a panel of BXD recombinant inbred (RI) mouse strains. Candidate upstream regulators within a locus were defined using single nucleotide polymorphism databases and promoter motif databases.

RESULTS: The acute phase response of rat retina, brain, and spinal cord was dominated by transcription …

The Kidney-Specific Wnk1 Isoform Is Induced By Aldosterone And Stimulates Epithelial Sodium Channel-Mediated Na+ Transport, Anikó Naray-Fejes-Toth, Peter M. Snyder, Géza Fejes-Toth

Dartmouth Scholarship

WNK1 belongs to a unique family of Ser/Thr kinases that have been implicated in the control of blood pressure. Intronic deletions in the WNK1 gene result in its overexpression and lead to pseudohypoaldosteronism type II, a disease with salt-sensitive hypertension and hyperkalemia. How overexpression of WNK1 leads to Na⁺ retention and hypertension is not entirely clear. Similarly, there is no information on the hormonal regulation of expression of WNK kinases. There are two main WNK1 transcripts expressed in the kidney: the originally described “long” WNK1 and a shorter transcript that is specifically expressed in the kidney (KS-WNK1). The goal …

Regulatory Role Of Glycogen Synthase Kinase 3 For Transcriptional Activity Of Add1/Srebp1c, Kang Ho Kim, Min Jeong Song, Eung Jae Yoo, Sung Sik Choe, Sang Dai Park, Jae Bum Kim

Faculty, Staff and Student Publications

Adipocyte determination- and differentiation-dependent factor 1 (ADD1) plays important roles in lipid metabolism and insulin-dependent gene expression. Because insulin stimulates carbohydrate and lipid synthesis, it would be important to decipher how the transcriptional activity of ADD1/SREBP1c is regulated in the insulin signaling pathway. In this study, we demonstrated that glycogen synthase kinase (GSK)-3 negatively regulates the transcriptional activity of ADD1/SREBP1c. GSK3 inhibitors enhanced a transcriptional activity of ADD1/SREBP1c and expression of ADD1/SREBP1c target genes including fatty acid synthase (FAS), acetyl-CoA carboxylase 1 (ACC1), and steroyl-CoA desaturase 1 (SCD1) in adipocytes and hepatocytes. In contrast, overexpression of GSK3beta down-regulated the transcriptional …

Characterization Of The Chicken Inward Rectifier K+ Channel Irk1/Kir2.1 Gene., Hideki Mutai, Lawrence C Kenyon, Emily Locke, Nami Kikuchi, John Carl Oberholtzer

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Inward rectifier potassium channels (IRK) contribute to the normal function of skeletal and cardiac muscle cells. The chick inward rectifier K+ channel cIRK1/Kir2.1 is expressed in skeletal muscle, heart, brain, but not in liver; a distribution similar but not identical to that of mouse Kir2.1. We set out to explore regulatory domains of the cIRK1 promoter that enhance or inhibit expression of the gene in different cell types. RESULTS: We cloned and characterized the 5'-flanking region of cIRK1. cIRK1 contains two exons with splice sites in the 5'-untranslated region, a structure similar to mouse and human orthologs. cIRK1 has …

Rgs14 Is A Mitotic Spindle Protein Essential From The First Division Of The Mammalian Zygote., Luke Martin-Mccaffrey, Francis S Willard, Antonio J Oliveira-Dos-Santos, David R C Natale, Bryan E Snow, Randall J Kimple, Agnieszka Pajak, Andrew J Watson, Lina Dagnino, Josef M Penninger, David P Siderovski, Sudhir J A D'Souza

Obstetrics & Gynaecology Publications

Heterotrimeric G protein alpha subunits, RGS proteins, and GoLoco motif proteins have been recently implicated in the control of mitotic spindle dynamics in C. elegans and D. melanogaster. Here we show that "regulator of G protein signaling-14" (RGS14) is expressed by the mouse embryonic genome immediately prior to the first mitosis, where it colocalizes with the anastral mitotic apparatus of the mouse zygote. Loss of Rgs14 expression in the mouse zygote results in cytofragmentation and failure to progress to the 2-cell stage. RGS14 is found in all tissues and segregates to the nucleus in interphase and to the mitotic spindle …

A Vibrio Cholerae Classical Tcpa Amino Acid Sequence Induces Protective Antibody That Binds An Area Hypothesized To Be Important For Toxin-Coregulated Pilus Structure, Ronald K. Taylor, Thomas J. Kirn, Michael D. Meeks, Terri K. Wade, William F. Wade

Dartmouth Scholarship

Vibrio cholerae is a gram-negative bacterium that has been associated with cholera pandemics since the early 1800s. Whole-cell, killed, and live-attenuated oral cholera vaccines are in use. We and others have focused on the development of a subunit cholera vaccine that features standardized epitopes from various V. cholerae macromolecules that are known to induce protective antibody responses. TcpA protein is assembled into toxin-coregulated pilus (TCP), a type IVb pilus required for V. cholerae colonization, and thus is a strong candidate for a cholera subunit vaccine. Polypeptides (24 to 26 amino acids) in TcpA that can induce protective antibody responses have …

Heme Oxygenase-2 Gene Deletion Attenuates Oxidative Stress In Neurons Exposed To Extracellular Hemin., Raymond F Regan, Jing Chen, Luna Benvenisti-Zarom

Department of Emergency Medicine Faculty Papers

BACKGROUND: Hemin, the oxidized form of heme, accumulates in intracranial hematomas and is a potent oxidant. Growing evidence suggests that it contributes to delayed injury to surrounding tissue, and that this process is affected by the heme oxygenase enzymes. In a prior study, heme oxygenase-2 gene deletion increased the vulnerability of cultured cortical astrocytes to hemin. The present study tested the effect of HO-2 gene deletion on protein oxidation, reactive oxygen species formation, and cell viability after mixed cortical neuron/astrocyte cultures were incubated with neurotoxic concentrations of hemin. RESULTS: Continuous exposure of wild-type cultures to 1-10 microM hemin for 14 …

Combined Adipocyte-Macrophage Fatty Acid-Binding Protein Deficiency Improves Metabolism, Atherosclerosis, And Survival In Apolipoprotein E-Deficient Mice., Jeffrey Boord, Kazuhisa Maeda, Liza Makowski, Vladimir R Babaev, Sergio Fazio, Macrae F Linton, Gökhan S Hotamisligil

Hospital Medicine

BACKGROUND: The adipocyte fatty acid-binding protein (FABP) aP2 is expressed by adipocytes and macrophages and modulates insulin resistance, glucose and lipid metabolism, and atherosclerosis. Insulin sensitivity is improved in obese but not in lean aP2-deficient mice. A second fatty acid-binding protein, mal1, also is expressed in adipocytes and macrophages, and mal1 deficiency produces similar effects on insulin resistance. We tested the hypothesis that combined aP2 and mal1 deficiency would produce synergistic effects on metabolism and reduce atherosclerosis in apolipoprotein E-deficient (apoE-/-) mice.

METHODS AND RESULTS: Male and female apoE-/- mice null for both aP2 and mal1 (3KO) and apoE-/- controls …

Cd4+ T Cells In The Pathogenesis Of Murine Ocular Toxoplasmosis, Fangli Lu, Shiguang Huang, Lloyd H. Kasper

Dartmouth Scholarship

The role of CD4⁺ T cells in the pathogenesis of ocular toxoplasmosis was investigated in murine models utilizing inbred C57BL/6 mice deficient either in CD4⁺, CD8⁺, or B cells (μMT). Severe necrosis and inflammation with replicating parasites were observed in the eyes of control mice after primary ocular infection, and near-normal histology with few tachyzoites was observed in the eyes of mice immunized intraperitoneally with the avirulent ts-4 strain followed by intraocular challenge with the RH strain of Toxoplasma gondii. In contrast, mild inflammation without evidence of necrosis associated with increased parasite burdens were …

Nf-Kappab And Ap-1 Connection: Mechanism Of Nf-Kappab-Dependent Regulation Of Ap-1 Activity, Shuichi Fujioka, Jiangong Niu, Christian Schmidt, Guido M Sclabas, Bailu Peng, Tadashi Uwagawa, Zhongkui Li, Douglas B Evans, James L Abbruzzese, Paul J Chiao

Faculty, Staff and Student Publications

Nuclear factor kappaB (NF-kappaB) and activator protein 1 (AP-1) transcription factors regulate many important biological and pathological processes. Activation of NF-kappaB is regulated by the inducible phosphorylation of NF-kappaB inhibitor IkappaB by IkappaB kinase. In contrast, Fos, a key component of AP-1, is primarily transcriptionally regulated by serum responsive factors (SRFs) and ternary complex factors (TCFs). Despite these different regulatory mechanisms, there is an intriguing possibility that NF-kappaB and AP-1 may modulate each other, thus expanding the scope of these two rapidly inducible transcription factors. To determine whether NF-kappaB activity is involved in the regulation of fos expression in response …

Esophageal Muscle Physiology And Morphogenesis Require Assembly Of A Collagen Xix-Rich Basement Membrane Zone., Hideaki Sumiyoshi, Niv Mor, Sui Y Lee, Stephen Doty, Scott Henderson, Shizuko Tanaka, Hidekatsu Yoshioka, Satish Rattan, Francesco Ramirez

Department of Medicine Faculty Papers

Collagen XIX is an extremely rare extracellular matrix component that localizes to basement membrane zones and is transiently expressed by differentiating muscle cells. Characterization of mice harboring null and structural mutations of the collagen XIX (Col19a1) gene has revealed the critical contribution of this matrix protein to muscle physiology and differentiation. The phenotype includes smooth muscle motor dysfunction and hypertensive sphincter resulting from impaired swallowing-induced, nitric oxide-dependent relaxation of the sphincteric muscle. Muscle dysfunction was correlated with a disorganized matrix and a normal complement of enteric neurons and interstitial cells of Cajal. Mice without collagen XIX exhibit an additional defect, …

Gitr Activation Induces An Opposite Effect On Alloreactive Cd4(+) And Cd8(+) T Cells In Graft-Versus-Host Disease., Stephanie J Muriglan, Teresa Ramirez-Montagut, Onder Alpdogan, Thomas W Van Huystee, Jeffrey M Eng, Vanessa M Hubbard, Adam A Kochman, Kartono H Tjoe, Carlo Riccardi, Pier Paolo Pandolfi, Shimon Sakaguchi, Alan N Houghton, Marcel R M Van Den Brink

Department of Medical Oncology Faculty Papers

Glucocorticoid-induced tumor necrosis factor receptor family-related gene (GITR) is a member of the tumor necrosis factor receptor (TNFR) family that is expressed at low levels on unstimulated T cells, B cells, and macrophages. Upon activation, CD4(+) and CD8(+) T cells up-regulate GITR expression, whereas immunoregulatory T cells constitutively express high levels of GITR. Here, we show that GITR may regulate alloreactive responses during graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT). Using a BMT model with major histocompatibility complex class I and class II disparity, we demonstrate that GITR stimulation in vitro and in vivo enhances alloreactive CD8(+)CD25(-) T …

A Novel Triterpenoid Induces Transforming Growth Factor Β Production By Intraepithelial Lymphocytes To Prevent Ileitis, Laurie A. Minns, Dominique Buzoni-Gatel, Kenneth H. Ely, Nicolas Rachinel, Souphalone Luangsay, Lloyd H. Kasper

Dartmouth Scholarship

The loss of homeostasis is a hallmark of inflammatory bowel disease. Oral infection of susceptible mice with Toxoplasma gondii results in an acute lethal ileitis characterized by increased interferon γ, tumor necrosis factor α, and inducible nitric oxide synthase; homeostasis results from transforming growth factor β production by intraepithelial lymphocytes. The synthetic oleanane triterpenoid 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO) is a potent anti-inflammatory molecule previously shown in vitro to suppress the de novo synthesis of inducible nitric oxide synthase and to induce the transcription and activation of genes from the transforming growth factor β signaling pathway. We evaluated the immune response in …

Endogenous No Regulates Superoxide Production At Low Oxygen Concentrations By Modifying The Redox State Of Cytochrome C Oxidase, Miriam Palacios-Callender, Marisol Quintero, Veronica S. Hollis, Roger J. Springett, Salvador Moncada

Dartmouth Scholarship

We have investigated in whole cells whether, at low oxygen concentrations ([O(2)]), endogenous nitric oxide (NO) modulates the redox state of the mitochondrial electron transport chain (ETC), and whether such an action has any signaling consequences. Using a polarographic-and-spectroscopic-coupled system, we monitored redox changes in the ETC cytochromes b(H), cc(1), and aa(3) during cellular respiration. The rate of O(2) consumption (VO(2)) remained constant until [O(2)] fell below 15 microM, whereas the onset of reduction of cytochromes aa(3), part of the terminal ETC enzyme cytochrome c oxidase, occurred at approximately 50 microM O(2). Incubation of the cells with an inhibitor of …

Deletion Of The Na/K-Atpase Alpha1-Subunit Gene (Atp1a1) Does Not Prevent Cavitation Of The Preimplantation Mouse Embryo., L C Barcroft, A E Moseley, J B Lingrel, A J Watson

Obstetrics & Gynaecology Publications

Increases in Na/K-ATPase activity occur concurrently with the onset of cavitation and are associated with increases in Na(+)-pump subunit mRNA and protein expression. We have hypothesized that the alpha1-isozyme of the Na/K-ATPase is required to mediate blastocyst formation. We have tested this hypothesis by characterizing preimplantation development in mice with a targeted disruption of the Na/K-ATPase alpha1-subunit (Atp1a1) using embryos acquired from matings between Atp1a1 heterozygous mice. Mouse embryos homozygous for a null mutation in the Na/K-ATPase alpha1-subunit gene are able to undergo compaction and cavitation. These findings demonstrate that trophectoderm transport mechanisms are maintained in the absence of the …

Conversion Of Myoblasts To Physiologically Active Neuronal Phenotype, Yumi Watanabe, Sei Kameoka, Vidya Gopalakrishnan, Kenneth D Aldape, Zhizhong Z Pan, Frederick F Lang, Sadhan Majumder

Faculty, Staff and Student Publications

Repressor element 1 (RE1)-silencing transcription factor (REST)/neuron-restrictive silencer factor (NRSF) can repress several terminal neuronal differentiation genes by binding to a specific DNA sequence (RE1/neuron-restrictive silencer element [NRSE]) present in their regulatory regions. REST-VP16 binds to the same RE1/NRSE, but activates these REST/NRSF target genes. However, it is unclear whether REST-VP16 expression is sufficient to cause formation of functional neurons either from neural stem cells or from heterologous stem cells. Here we show that the expression of REST-VP16 in myoblasts grown under muscle differentiation conditions blocked entry into the muscle differentiation pathway, countered endogenous REST/NRSF-dependent repression, activated the REST/NRSF target …

P38 Mapk Signaling During Murine Preimplantation Development., David R Natale, Andrew J M Paliga, Frank Beier, S J A D'Souza, Andrew J Watson

Obstetrics & Gynaecology Publications

Mitogen-activated protein kinase (MAPK) pathways mediate some important cellular processes and are likely to also regulate preimplantation development. The role of p38 MAP kinase signaling during murine preimplantation development was investigated in the present study. p38 MAPK, p38-regulated or -activated kinase (PRAK; MK5), map kinase-activated protein kinase 2 (MK2), and heat shock protein 25 (hsp25) mRNAs and proteins were detected throughout preimplantation development. Two-cell stage embryos cultured in the presence of SB220025 and SB203580 (specific inhibitors of p38 MAPK alpha/beta), progressed to the eight-cell stage with the same frequency as controls; however, treated embryos halted their development at the 8- …

Combined Tlr And Cd40 Triggering Induces Potent Cd8+ T Cell Expansion With Variable Dependence On Type I Ifn, Cory L. Ahonen, Christie L. Doxsee, Sean M. M. Mcgurran, Tony R. Riter, William F. Wade, Richard J. Barth, John P. Vasilakos, Randolph J. Noelle, Ross M. Kedl

Dartmouth Scholarship

Toll-like receptors are important in the activation of innate immunity, and CD40 is a molecule critical for many T and B cell responses. Whereas agonists for either pathway have been used as vaccine adjuvants, we show that a combination of Toll-like receptor (TLR)7 and CD40 agonists synergize to stimulate CD8⁺ T cell responses 10–20-fold greater than the use of either agonist alone. Antigen-specific CD8⁺ T cells elicited from combination CD40/TLR7 treatment demonstrated both lytic activities and interferon (IFN)γ production and an enhanced secondary response to antigenic challenge. Agonists for TLRs 2/6, 3, 4, and 9 also synergized with …

The Tumor Suppressor Lkb1 Kinase Directly Activates Amp-Activated Kinase And Regulates Apoptosis In Response To Energy Stress, Reuben J. Shaw, Monica Kosmatka, Nabeel Bardeesy, Rebecca L. Hurley, Lee A. Witters, Ronald A. Depinho, Lewis C. Cantley

Dartmouth Scholarship

AMP-activated protein kinase (AMPK) is a highly conserved sensor of cellular energy status found in all eukaryotic cells. AMPK is activated by stimuli that increase the cellular AMP/ATP ratio. Essential to activation of AMPK is its phosphorylation at Thr-172 by an upstream kinase, AMPKK, whose identity in mammalian cells has remained elusive. Here we present biochemical and genetic evidence indicating that the LKB1 serine/threonine kinase, the gene inactivated in the Peutz-Jeghers familial cancer syndrome, is the dominant regulator of AMPK activation in several mammalian cell types. We show that LKB1 directly phosphorylates Thr-172 of AMPKalpha in vitro and activates its …

Hearing Loss And Retarded Cochlear Development In Mice Lacking Type 2 Iodothyronine Deiodinase, Lily Ng, Richard J. Goodyear, Chad A. Woods, Mark J. Schneider

Dartmouth Scholarship

The later stages of cochlear differentiation and the developmental onset of hearing require thyroid hormone. Although thyroid hormone receptors (TRs) are a prerequisite for this process, it is likely that other factors modify TR activity during cochlear development. The mouse cochlea expresses type 2 deiodinase (D2), an enzyme that converts thyroxine, the main form of thyroid hormone in the circulation, into 3,5,3'-triiodothyronine (T3) the major ligand for TRs. Here, we show that D2-deficient mice have circulating thyroid hormone levels that would normally be adequate to allow hearing to develop but they exhibit an auditory phenotype similar to that caused by …

Immune Responses Of Different Mouse Strains After Challenge With Equivalent Lethal Doses Of Toxoplasma Gondii, Y. H. Lee, L. H. Kasper

Dartmouth Scholarship

Most immunological studies that utilize different strains of inbred mice following T. gondii infection fail to compensate for differences in host susceptibility to the size of the parasite innoculum. To address this concern, susceptible C57BL/6 and resistant CBA/J mice were orally infected with either an equivalent 50 % lethal dose (LD₅₀) of brain cysts of the 76K strain of T. gondii (15 cysts in C57BL/6, 400 cysts in CBA/J) or the same dose of parasites in each mouse strain. C57BL/6 mice receiving 400 cysts (LD₅₀ of CBA/J mice) died post infection, whereas CBA/J mice that received 15 …

The Nad(P)H Oxidase Homolog Nox4 Modulates Insulin-Stimulated Generation Of H202 And Plays An Integral Role In Insulin Signal Transduction, Kalyankar Mahadev, Hiroyuki Motoshima, Xiangdong Wu, Jean Marie Ruddy, Rebecca S. Arnold, Guangjie Cheng, J. David Lambeth, Barry J. Goldstein

Department of Medicine Faculty Papers

Insulin stimulation of target cells elicits a burst of H₂O₂ that enhances tyrosine phosphorylation of the insulin receptor and its cellular substrate proteins as well as distal signaling events in the insulin action cascade. The molecular mechanism coupling the insulin receptor with the cellular oxidant-generating apparatus has not been elucidated. Using reverse transcription-PCR and Northern blot analyses, we found that Nox4, a homolog of gp91phox, the phagocytic NAD(P)H oxidase catalytic subunit, is prominently expressed in insulin-sensitive adipose cells. Adenovirus-mediated expression of Nox4 deletion constructs lacking NAD(P)H or FAD/NAD(P)H cofactor binding domains acted in a dominant-negative …

All-1/Mll1, A Homologue Of Drosophila Trithorax, Modifies Chromatin And Is Directly Involved In Infant Acute Leukaemia., E Canaani, T Nakamura, T Rozovskaia, S T Smith, T Mori, C M Croce, Alexander Mazo

Kimmel Cancer Center Faculty Papers

Rearrangements of the ALL-1/MLL1 gene underlie the majority of infant acute leukaemias, as well as of therapy-related leukaemias developing in cancer patients treated with inhibitors of topoisomerase II, such as VP16 and doxorubicin. The rearrangements fuse ALL-1 to any of >50 partner genes or to itself. Here, we describe the unique features of ALL-1-associated leukaemias, and recent progress in understanding molecular mechanisms involved in the activity of the ALL-1 protein and of its Drosophila homologue TRITHORAX.

Muc4 Mucin Expression In Human Pancreatic Tumours Is Affected By Organ Environment: The Possible Role Of Tgfbeta2., A. Choudhury, N. Moniaux, A. B. Ulrich, B. M. Schmied, J. Standop, Parviz M. Pour, S. J. Gendler, Michael A. Hollingsworth, J-P Aubert, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

MUC4 is highly expressed in human pancreatic tumours and pancreatic tumour cell lines, but is minimally or not expressed in normal pancreas or chronic pancreatitis. Here, we investigated the aberrant regulation of MUC4 expression in vivo using clonal human pancreatic tumour cells (CD18/HPAF) grown either orthotopically in the pancreas (OT) or ectopically in subcutaneous tissue (SC) in the nude mice. Histological examination of the OT and SC tumours showed moderately differentiated and anaplastic morphology, respectively. The OT tumour cells showed metastases to distant lymph nodes and faster tumour growth (P