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Full-Text Articles in Diseases

Crosstalk Between Brca-Fanconi Anemia And Mismatch Repair Pathways Prevents Msh2-Dependent Aberrant Dna Damage Responses, Min Peng, Jenny X. Xie, Anna J. Ucher, Janet Stavnezer, Sharon B. Cantor Aug 2015

Crosstalk Between Brca-Fanconi Anemia And Mismatch Repair Pathways Prevents Msh2-Dependent Aberrant Dna Damage Responses, Min Peng, Jenny X. Xie, Anna J. Ucher, Janet Stavnezer, Sharon B. Cantor

Janet M. Stavnezer

Several proteins in the BRCA-Fanconi anemia (FA) pathway, such as FANCJ, BRCA1, and FANCD2, interact with mismatch repair (MMR) pathway factors, but the significance of this link remains unknown. Unlike the BRCA-FA pathway, the MMR pathway is not essential for cells to survive toxic DNA interstrand crosslinks (ICLs), although MMR proteins bind ICLs and other DNA structures that form at stalled replication forks. We hypothesized that MMR proteins corrupt ICL repair in cells that lack crosstalk between BRCA-FA and MMR pathways. Here, we show that ICL sensitivity of cells lacking the interaction between FANCJ and the MMR protein MLH1 is …


Alcohol And Hcv: Implications For Liver Cancer, Gyongyi Szabo, Banishree Saha, Terence Bukong Jun 2015

Alcohol And Hcv: Implications For Liver Cancer, Gyongyi Szabo, Banishree Saha, Terence Bukong

Gyongyi Szabo

Liver cancers are one of the deadliest known malignancies which are increasingly becoming a major public health problem in both developed and developing countries. Overwhelming evidence suggests a strong role of infection with hepatitis B and C virus (HBV and HCV), alcohol abuse, as well as metabolic diseases such as obesity and diabetes either individually or synergistically to cause or exacerbate the development of liver cancers. Although numerous etiologic mechanisms for liver cancer development have been advanced and well characterized, the lack of definite curative treatments means that gaps in knowledge still exist in identifying key molecular mechanisms and pathways …


Gut-Liver Axis In Alcoholic Liver Disease, Gyongyi Szabo Jun 2015

Gut-Liver Axis In Alcoholic Liver Disease, Gyongyi Szabo

Gyongyi Szabo

Alcoholic liver disease (ALD) has been among the leading causes of cirrhosis and liver-related death worldwide for decades. Early discoveries in alcoholic liver disease identified increased levels of bacterial endotoxin in the portal circulation, suggesting a role for gut-derived toxins in ALD. Indeed, alcohol consumption can disrupt the intestinal epithelial barrier and result in increased gut permeability that increasingly is recognized as a major factor in ALD. Bacterial endotoxin, lipopolysaccharide, is a prototypic microbe-derived inflammatory signal that contributes to inflammation in ALD through activation of the Toll-like receptor 4. Recent studies also have shown that alcohol consumption is associated with …


Osteopontin: A Bridge Between Bone And The Immune System, Ellen M. Gravallese Apr 2015

Osteopontin: A Bridge Between Bone And The Immune System, Ellen M. Gravallese

Ellen M. Gravallese

The molecular mechanisms underlying the putative role of osteopontin in the chronic inflammatory disease rheumatoid arthritis are unclear. A study in a murine model of arthritis now demonstrates that a specific antibody directed against the exposed osteopontin epitope SLAYGLR is capable of preventing inflammatory cell infiltration in arthritic joints.


The Role Of Tnf-Receptor Family Members And Other Traf-Dependent Receptors In Bone Resorption, Ellen M. Gravallese, Deborah L. Galson, Steven R. Goldring, Philip E. Auron Apr 2015

The Role Of Tnf-Receptor Family Members And Other Traf-Dependent Receptors In Bone Resorption, Ellen M. Gravallese, Deborah L. Galson, Steven R. Goldring, Philip E. Auron

Ellen M. Gravallese

The contribution of osteoclasts to the process of bone loss in inflammatory arthritis has recently been demonstrated. Studies in osteoclast biology have led to the identification of factors responsible for the differentiation and activation of osteoclasts, the most important of which is the receptor activator of NF-kappa B ligand/osteoclast differentiation factor (RANKL/ODF), a tumor necrosis factor (TNF)-like protein. The RANKL/ODF receptor, receptor activator of NF-kappa B (RANK), is a TNF-receptor family member present on both osteoclast precursors and mature osteoclasts. Like other TNF-family receptors and the IL-1 receptor, RANK mediates its signal transduction via TNF receptor-associated factor (TRAF) proteins, suggesting …


Critical Roles For Interleukin 1 And Tumor Necrosis Factor Alpha In Antibody-Induced Arthritis, Hong Ji, Allison Pettit, Koichiro Ohmura, Adriana Ortiz-Lopez, Veronique Duchatelle, Claude Degott, Ellen M. Gravallese, Diane Mathis, Christophe Benoist Apr 2015

Critical Roles For Interleukin 1 And Tumor Necrosis Factor Alpha In Antibody-Induced Arthritis, Hong Ji, Allison Pettit, Koichiro Ohmura, Adriana Ortiz-Lopez, Veronique Duchatelle, Claude Degott, Ellen M. Gravallese, Diane Mathis, Christophe Benoist

Ellen M. Gravallese

In spontaneous inflammatory arthritis of K/BxN T cell receptor transgenic mice, the effector phase of the disease is provoked by binding of immunoglobulins (Igs) to joint surfaces. Inflammatory cytokines are known to be involved in human inflammatory arthritis, in particular rheumatoid arthritis, although, overall, the pathogenetic mechanisms of the human affliction remain unclear. To explore the analogy between the K/BxN model and human patients, we assessed the role and relative importance of inflammatory cytokines in K/BxN joint inflammation by transferring arthritogenic serum into a panel of genetically deficient recipients. Interleukin (IL)-1 proved absolutely necessary. Tumor necrosis factor (TNF)-alpha was also …


Long-Term Changes Of Functional Mri-Based Brain Function, Behavioral Status, And Histopathology After Transient Focal Cerebral Ischemia In Rats, Kenneth Sicard, Nils Henninger, Marc Fisher, Timothy Duong, Craig Ferris Apr 2015

Long-Term Changes Of Functional Mri-Based Brain Function, Behavioral Status, And Histopathology After Transient Focal Cerebral Ischemia In Rats, Kenneth Sicard, Nils Henninger, Marc Fisher, Timothy Duong, Craig Ferris

Nils Henninger

BACKGROUND AND PURPOSE: The relation between recovery of brain function and neurological status after clinical and experimental cerebral ischemia is incompletely characterized. We assessed the evolution of ischemic injury, behavioral status, and brain activity at acute to chronic periods after transient middle cerebral artery occlusion (tMCAO) in rats. METHODS: Male Sprague-Dawley rats were subjected to 20-minute tMCAO (n=10) or sham operation (n=10). Sensorimotor behavioral testing and multimodal (diffusion, perfusion, T2, and functional) MRI, as well as postmortem hematoxylin-eosin staining, were performed before and up to 21 days after tMCAO. MRI and histological parameters were evaluated in 5 regions of interest …


Stimulating Circle Of Willis Nerve Fibers Preserves The Diffusion-Perfusion Mismatch In Experimental Stroke, Nils Henninger, Marc Fisher Apr 2015

Stimulating Circle Of Willis Nerve Fibers Preserves The Diffusion-Perfusion Mismatch In Experimental Stroke, Nils Henninger, Marc Fisher

Nils Henninger

BACKGROUND AND PURPOSE: Stimulation of the nerves traversing the ethmoidal foramen (including postsynaptic, parasympathetic projections from the sphenopalatine ganglion [SPG], henceforth referred to as "SPG-stimulation") has been shown to elevate cerebral blood flow (CBF) and to be neuroprotective after permanent, middle cerebral artery occlusion (pMCAO). METHODS: Employing diffusion (DWI)- and perfusion (PWI) weighted MRI, the effect of SPG-stimulation (started at 60 minutes post-MCAO) on the spatiotemporal evolution of ischemia during and after pMCAO was investigated. In an additional experiment, regional CBF changes were investigated in the nonischemic brain. RESULTS: In the nonischemic brain, SPG stimulation significantly elevated CBF predominantly within …


Dual Engagement Of The Nlrp3 And Aim2 Inflammasomes By Plasmodium-Derived Hemozoin And Dna During Malaria, Parisa Kalantari, Rosane B. Deoliveira, Jennie Chan, Yolanda Corbett, Vijay A. K. Rathinam, Andrea Stutz, Eicke Latz, Ricardo T. Gazzinelli, Douglas T. Golenbock, Katherine A. Fitzgerald Dec 2014

Dual Engagement Of The Nlrp3 And Aim2 Inflammasomes By Plasmodium-Derived Hemozoin And Dna During Malaria, Parisa Kalantari, Rosane B. Deoliveira, Jennie Chan, Yolanda Corbett, Vijay A. K. Rathinam, Andrea Stutz, Eicke Latz, Ricardo T. Gazzinelli, Douglas T. Golenbock, Katherine A. Fitzgerald

Katherine A. Fitzgerald

Hemozoin (Hz) is the crystalline detoxification product of hemoglobin in Plasmodium-infected erythrocytes. We previously proposed that Hz can carry plasmodial DNA into a subcellular compartment that is accessible to Toll-like receptor 9 (TLR9), inducing an inflammatory signal. Hz also activates the NLRP3 inflammasome in primed cells. We found that Hz appears to colocalize with DNA in infected erythrocytes, even before RBC rupture or phagolysosomal digestion. Using synthetic Hz coated in vitro with plasmodial genomic DNA (gDNA) or CpG oligodeoxynucleotides, we observed that DNA-complexed Hz induced TLR9 translocation, providing a priming and an activation signal for inflammasomes. After phagocytosis, Hz and …


Sting-Irf3 Pathway Links Endoplasmic Reticulum Stress With Hepatocyte Apoptosis In Early Alcoholic Liver Disease, Jan Petrasek, Arvin Iracheta-Vellve, Timea Csak, Abhishek Satishchandran, Karen Kodys, Evelyn A. Kurt-Jones, Katherine A. Fitzgerald, Gyongyi Szabo Sep 2014

Sting-Irf3 Pathway Links Endoplasmic Reticulum Stress With Hepatocyte Apoptosis In Early Alcoholic Liver Disease, Jan Petrasek, Arvin Iracheta-Vellve, Timea Csak, Abhishek Satishchandran, Karen Kodys, Evelyn A. Kurt-Jones, Katherine A. Fitzgerald, Gyongyi Szabo

Katherine A. Fitzgerald

Emerging evidence suggests that innate immunity drives alcoholic liver disease (ALD) and that the interferon regulatory factor 3 (IRF3),a transcription factor regulating innate immune responses, is indispensable for the development of ALD. Here we report that IRF3 mediates ALD via linking endoplasmic reticulum (ER) stress with apoptotic signaling in hepatocytes. We found that ethanol induced ER stress and triggered the association of IRF3 with the ER adaptor, stimulator of interferon genes (STING), as well as subsequent phosphorylation of IRF3. Activated IRF3 associated with the proapoptotic molecule Bax [B-cell lymphoma 2 (Bcl2)-associated X protein] and contributed to hepatocyte apoptosis. Deficiency of …


Binge Ethanol And Liver: New Molecular Developments, Shivendra Shukla, Stephen Pruett, Gyongyi Szabo, Gavin Arteel Sep 2014

Binge Ethanol And Liver: New Molecular Developments, Shivendra Shukla, Stephen Pruett, Gyongyi Szabo, Gavin Arteel

Gyongyi Szabo

Binge consumption of alcohol is an alarming global health problem. Binge (acute) ethanol (EtOH) is implicated in the pathophysiology of alcoholic liver disease (ALD). New studies from experimental animals and from humans indicate that binge EtOH has profound effects on immunological, signaling, and epigenetic parameters of the liver. This is in addition to the known metabolic effects of acute EtOH. Binge EtOH alters the levels of several cellular components and dramatically amplifies liver injury in chronically EtOH exposed liver. These studies highlight the importance of molecular investigations into binge effects of EtOH for a better understanding of ALD and also …


Chronic Alcohol-Induced Microrna-155 Contributes To Neuroinflammation In A Tlr4-Dependent Manner In Mice, Dora Lippai, Shashi Bala, Timea Csak, Evelyn A. Kurt-Jones, Gyongyi Szabo Sep 2014

Chronic Alcohol-Induced Microrna-155 Contributes To Neuroinflammation In A Tlr4-Dependent Manner In Mice, Dora Lippai, Shashi Bala, Timea Csak, Evelyn A. Kurt-Jones, Gyongyi Szabo

Gyongyi Szabo

INTRODUCTION: Alcohol-induced neuroinflammation is mediated by pro-inflammatory cytokines and chemokines including tumor necrosis factor-alpha (TNFalpha), monocyte chemotactic protein-1 (MCP1) and interleukin-1-beta (IL-1beta). Toll-like receptor-4 (TLR4) pathway induced nuclear factor-kappaB (NF-kappaB) activation is involved in the pathogenesis of alcohol-induced neuroinflammation. Inflammation is a highly regulated process. Recent studies suggest that microRNAs (miRNAs) play crucial role in fine tuning gene expression and miR-155 is a major regulator of inflammation in immune cells after TLR stimulation. AIM: To evaluate the role of miR-155 in the pathogenesis of alcohol-induced neuroinflammation. METHODS: Wild type (WT), miR-155- and TLR4-knockout (KO) mice received 5% ethanol-containing or isocaloric …


Toll-Like Receptors In Liver Disease, Jan Petrasek, Timea Csak, Gyongyi Szabo Sep 2014

Toll-Like Receptors In Liver Disease, Jan Petrasek, Timea Csak, Gyongyi Szabo

Gyongyi Szabo

Activation of inflammatory signaling pathways is of central importance in the pathogenesis of alcoholic liver disease (ALD) and nonalcoholic steatohepatitis (NASH). Recent studies demonstrated that Toll-like receptors, the sensors of microbial and endogenous danger signals, are expressed and activated in innate immune cells as well as in parenchymal cells in the liver and thereby contribute to ALD and NASH. In this review, we emphasize the importance of gut-derived endotoxin and its recognition by TLR4 in the liver. The significance of TLR-induced intracellular signaling pathways and cytokine production as well as the contribution of individual cell types to the inflammation is …


Sting-Irf3 Pathway Links Endoplasmic Reticulum Stress With Hepatocyte Apoptosis In Early Alcoholic Liver Disease, Jan Petrasek, Arvin Iracheta-Vellve, Timea Csak, Abhishek Satishchandran, Karen Kodys, Evelyn A. Kurt-Jones, Katherine A. Fitzgerald, Gyongyi Szabo Sep 2014

Sting-Irf3 Pathway Links Endoplasmic Reticulum Stress With Hepatocyte Apoptosis In Early Alcoholic Liver Disease, Jan Petrasek, Arvin Iracheta-Vellve, Timea Csak, Abhishek Satishchandran, Karen Kodys, Evelyn A. Kurt-Jones, Katherine A. Fitzgerald, Gyongyi Szabo

Gyongyi Szabo

Emerging evidence suggests that innate immunity drives alcoholic liver disease (ALD) and that the interferon regulatory factor 3 (IRF3),a transcription factor regulating innate immune responses, is indispensable for the development of ALD. Here we report that IRF3 mediates ALD via linking endoplasmic reticulum (ER) stress with apoptotic signaling in hepatocytes. We found that ethanol induced ER stress and triggered the association of IRF3 with the ER adaptor, stimulator of interferon genes (STING), as well as subsequent phosphorylation of IRF3. Activated IRF3 associated with the proapoptotic molecule Bax [B-cell lymphoma 2 (Bcl2)-associated X protein] and contributed to hepatocyte apoptosis. Deficiency of …


The Genome Of Anopheles Darlingi, The Main Neotropical Malaria Vector, Osvaldo Marinotti, Adam R. Wespiser, Daniel R. Caffrey, Douglas T. Golenbock, Neal S. Silverman Apr 2014

The Genome Of Anopheles Darlingi, The Main Neotropical Malaria Vector, Osvaldo Marinotti, Adam R. Wespiser, Daniel R. Caffrey, Douglas T. Golenbock, Neal S. Silverman

Neal Silverman

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors approximately 100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In …


Dendritic Cells In Hepatitis C Infection: Can They (Help) Win The Battle, Angela Dolganiuc, Gyongyi Szabo Oct 2012

Dendritic Cells In Hepatitis C Infection: Can They (Help) Win The Battle, Angela Dolganiuc, Gyongyi Szabo

Gyongyi Szabo

Infection with hepatitis C virus (HCV) is a public health problem; it establishes a chronic course in ~85% of infected patients and increases their risk for developing liver cirrhosis, hepatocellular carcinoma, and significant extrahepatic manifestations. The mechanisms of HCV persistence remain elusive and are largely related to inefficient clearance of the virus by the host immune system. Dendritic cells (DCs) are the most efficient inducers of immune responses; they are capable of triggering productive immunity and maintaining the state of tolerance to self- and non-self antigens. During the past decade, multiple research groups have focused on DCs, in hopes of …


Hypoxia And Hypoxia Inducible Factors: Diverse Roles In Liver Diseases, Bharath Nath, Gyongyi Szabo Oct 2012

Hypoxia And Hypoxia Inducible Factors: Diverse Roles In Liver Diseases, Bharath Nath, Gyongyi Szabo

Gyongyi Szabo

Hypoxia has been shown to have a role in the pathogenesis of several forms of liver disease. The hypoxia inducible factors (HIFs) are a family of evolutionarily conserved transcriptional regulators that affect a homeostatic response to low oxygen tension and have been identified as key mediators of angiogenesis, inflammation, and metabolism. In this review we summarize the evidence for a role of HIFs across a range of hepatic pathophysiology. We describe regulation of the HIFs and review investigations that demonstrate a role for HIFs in the development of liver fibrosis, activation of innate immune pathways, hepatocellular carcinoma, as well as …


Mitochondrial Antiviral Signaling Protein Defect Links Impaired Antiviral Response And Liver Injury In Steatohepatitis In Mice, Timea Csak, Angela Dolganiuc, Karen Kodys, Bharath Nath, Jan Petrasek, Shashi Bala, Dora Lippai, Gyongyi Szabo Oct 2012

Mitochondrial Antiviral Signaling Protein Defect Links Impaired Antiviral Response And Liver Injury In Steatohepatitis In Mice, Timea Csak, Angela Dolganiuc, Karen Kodys, Bharath Nath, Jan Petrasek, Shashi Bala, Dora Lippai, Gyongyi Szabo

Gyongyi Szabo

Mitochondrial dysfunction is a pathogenic feature of nonalcoholic steatohepatitis (NASH). NASH complicates hepatotropic viral disease. The mitochondrial antiviral signaling protein (MAVS) is the adapter of helicase receptors involved in sensing double-stranded RNA (dsRNA). We hypothesized that impaired MAVS function may contribute to insufficient antiviral response and liver damage in steatohepatitis. We identified reduced MAVS protein levels and increased MAVS association with the proteasome subunit alpha type 7 (PSMA7) in livers from mice given a methionine-choline-deficient (MCD) diet. Decreased association of MAVS with mitochondria and increased cytosolic cytochrome c indicated mitochondrial damage in steatohepatitis. In vivo administration of the synthetic dsRNA …


An Essential Role For Monocyte Chemoattractant Protein-1 In Alcoholic Liver Injury: Regulation Of Proinflammatory Cytokines And Hepatic Steatosis In Mice, Pranoti Mandrekar, Aditya Ambade, Arlene Lim, Gyongyi Szabo, Donna Catalano Oct 2012

An Essential Role For Monocyte Chemoattractant Protein-1 In Alcoholic Liver Injury: Regulation Of Proinflammatory Cytokines And Hepatic Steatosis In Mice, Pranoti Mandrekar, Aditya Ambade, Arlene Lim, Gyongyi Szabo, Donna Catalano

Gyongyi Szabo

The importance of chemokines in alcoholic liver injury has been implicated. The role of the chemokine, monocyte chemoattractant protein-1 (MCP-1), elevated in patients with alcoholic liver disease is not yet understood. Here, we evaluated the pathophysiological significance of MCP-1 and its receptor, chemokine (C-C motif) receptor 2 (CCR2), in alcoholic liver injury. The Leiber-DeCarli diet containing alcohol or isocaloric control diets were fed to wild-type (WT) and MCP-1-deficient knockout (KO) mice for 6 weeks. In vivo and in vitro assays were performed to study the role of MCP-1 in alcoholic liver injury. MCP-1 was increased in Kupffer cells (KCs) as …


Hepatocyte-Specific Hypoxia-Inducible Factor-1alpha Is A Determinant Of Lipid Accumulation And Liver Injury In Alcohol-Induced Steatosis In Mice, Bharath Nath, Ivan Levin, Timea Csak, Jan Petrasek, Christian Mueller, Karen Kodys, Donna Catalano, Pranoti Mandrekar, Gyongyi Szabo Oct 2012

Hepatocyte-Specific Hypoxia-Inducible Factor-1alpha Is A Determinant Of Lipid Accumulation And Liver Injury In Alcohol-Induced Steatosis In Mice, Bharath Nath, Ivan Levin, Timea Csak, Jan Petrasek, Christian Mueller, Karen Kodys, Donna Catalano, Pranoti Mandrekar, Gyongyi Szabo

Gyongyi Szabo

Chronic alcohol causes hepatic steatosis and liver hypoxia. Hypoxia-regulated hypoxia-inducible factor 1-alpha, (HIF-1alpha) may regulate liporegulatory genes, but the relationship of HIF-1 to steatosis remains unknown. We investigated HIF-1alpha in alcohol-induced hepatic lipid accumulation. Alcohol administration resulted in steatosis, increased liver triglyceride levels, and increased serum alanine aminotransferase (ALT) levels, suggesting liver injury in wild-type (WT) mice. There was increased hepatic HIF-1alpha messenger RNA (mRNA), protein, and DNA-binding activity in alcohol-fed mice compared with controls. Mice engineered with hepatocyte-specific HIF-1 activation (HIF1dPA) had increased HIF-1alpha mRNA, protein, and DNA-binding activity, and alcohol feeding in HIF1dPA mice increased hepatomegaly and hepatic …


Lipopolysaccharide Induces And Activates The Nalp3 Inflammasome In The Liver, Michal Ganz, Timea Csak, Bharath D. Nath, Gyongyi Szabo Oct 2012

Lipopolysaccharide Induces And Activates The Nalp3 Inflammasome In The Liver, Michal Ganz, Timea Csak, Bharath D. Nath, Gyongyi Szabo

Gyongyi Szabo

AIM: To examine the activation of the Nalp3 inflammasome and its downstream targets following lipopolysaccharide (LPS)-induced stimulation in the liver. METHODS: Six-to-eight-week-old C57BL/6 chow fed mice were injected intraperitoneally with 0.5 mug/g bodyweight LPS and sacrificed 2, 4, 6, 18 or 24 h later. LPS-induced liver damage was confirmed by a biochemical assay to detect alanine aminotransferase (ALT) levels. To determine if LPS stimulation in the liver led to activation of the inflammasome, real-time quantitative polymerase chain reaction was used to evaluate the mRNA expression of components of the Nalp3 inflammasome. Enzyme-linked immunosorbent assays were used to determine the protein …


Fatty Acid And Endotoxin Activate Inflammasomes In Mouse Hepatocytes That Release Danger Signals To Stimulate Immune Cells, Timea Csak, Michal Ganz, Justin Pespisa, Karen Kodys, Angela Dolganiuc, Gyongyi Szabo Oct 2012

Fatty Acid And Endotoxin Activate Inflammasomes In Mouse Hepatocytes That Release Danger Signals To Stimulate Immune Cells, Timea Csak, Michal Ganz, Justin Pespisa, Karen Kodys, Angela Dolganiuc, Gyongyi Szabo

Gyongyi Szabo

The pathogenesis of nonalcoholic steatohepatitis (NASH) and inflammasome activation involves sequential hits. The inflammasome, which cleaves pro-interleukin-1beta (pro-IL-1beta) into secreted IL-1beta, is induced by endogenous and exogenous danger signals. Lipopolysaccharide (LPS), a toll-like receptor 4 ligand, plays a role in NASH and also activates the inflammasome. In this study, we hypothesized that the inflammasome is activated in NASH by multiple hits involving endogenous and exogenous danger signals. Using mouse models of methionine choline-deficient (MCD) diet-induced NASH and high-fat diet-induced NASH, we found up-regulation of the inflammasome [including NACHT, LRR, and PYD domains-containing protein 3 (NALP3; cryopyrin), apoptosis-associated speck-like CARD-domain containing …


Hepatocyte-Specific Hypoxia-Inducible Factor-1alpha Is A Determinant Of Lipid Accumulation And Liver Injury In Alcohol-Induced Steatosis In Mice, Bharath Nath, Ivan Levin, Timea Csak, Jan Petrasek, Christian Mueller, Karen Kodys, Donna Catalano, Pranoti Mandrekar, Gyongyi Szabo Oct 2012

Hepatocyte-Specific Hypoxia-Inducible Factor-1alpha Is A Determinant Of Lipid Accumulation And Liver Injury In Alcohol-Induced Steatosis In Mice, Bharath Nath, Ivan Levin, Timea Csak, Jan Petrasek, Christian Mueller, Karen Kodys, Donna Catalano, Pranoti Mandrekar, Gyongyi Szabo

Christian Mueller

Chronic alcohol causes hepatic steatosis and liver hypoxia. Hypoxia-regulated hypoxia-inducible factor 1-alpha, (HIF-1alpha) may regulate liporegulatory genes, but the relationship of HIF-1 to steatosis remains unknown. We investigated HIF-1alpha in alcohol-induced hepatic lipid accumulation. Alcohol administration resulted in steatosis, increased liver triglyceride levels, and increased serum alanine aminotransferase (ALT) levels, suggesting liver injury in wild-type (WT) mice. There was increased hepatic HIF-1alpha messenger RNA (mRNA), protein, and DNA-binding activity in alcohol-fed mice compared with controls. Mice engineered with hepatocyte-specific HIF-1 activation (HIF1dPA) had increased HIF-1alpha mRNA, protein, and DNA-binding activity, and alcohol feeding in HIF1dPA mice increased hepatomegaly and hepatic …


Evidence That Distinct States Of The Integrin Alpha6beta1 Interact With Laminin And An Adam, M. S. Chen, E. A. Almeida, A. P. Huovila, Y. Takahashi, Leslie M. Shaw, Arthur M. Mercurio, J. M. White Nov 2010

Evidence That Distinct States Of The Integrin Alpha6beta1 Interact With Laminin And An Adam, M. S. Chen, E. A. Almeida, A. P. Huovila, Y. Takahashi, Leslie M. Shaw, Arthur M. Mercurio, J. M. White

Arthur M. Mercurio

Integrins can exist in different functional states with low or high binding capacity for particular ligands. We previously provided evidence that the integrin alpha6beta1, on mouse eggs and on alpha6-transfected cells, interacted with the disintegrin domain of the sperm surface protein ADAM 2 (fertilin beta). In the present study we tested the hypothesis that different states of alpha6beta1 interact with fertilin and laminin, an extracellular matrix ligand for alpha6beta1. Using alpha6-transfected cells we found that treatments (e.g., with phorbol myristate acetate or MnCl2) that increased adhesion to laminin inhibited sperm binding. Conversely, treatments that inhibited laminin adhesion increased sperm binding. …


The Integrin Alpha6beta4 Functions In Carcinoma Cell Migration On Laminin-1 By Mediating The Formation And Stabilization Of Actin-Containing Motility Structures, Isaac Rabinovitz, Arthur M. Mercurio Nov 2010

The Integrin Alpha6beta4 Functions In Carcinoma Cell Migration On Laminin-1 By Mediating The Formation And Stabilization Of Actin-Containing Motility Structures, Isaac Rabinovitz, Arthur M. Mercurio

Arthur M. Mercurio

Functional studies on the alpha6beta4 integrin have focused primarily on its role in the organization of hemidesmosomes, stable adhesive structures that associate with the intermediate filament cytoskeleton. In this study, we examined the function of the alpha6beta4 integrin in clone A cells, a colon carcinoma cell line that expresses alpha6beta4 but no alpha6beta1 integrin and exhibits dynamic adhesion and motility on laminin-1. Time-lapse videomicroscopy of clone A cells on laminin-1 revealed that their migration is characterized by filopodial extension and stabilization followed by lamellae that extend in the direction of stabilized filopodia. A function-blocking mAb specific for the alpha6beta4 integrin …


Role Of E-Cadherin In The Response Of Tumor Cell Aggregates To Lymphatic, Venous And Arterial Flow: Measurement Of Cell-Cell Adhesion Strength, Stephen W. Byers, Connie L. Sommers, Becky Hoxter, Arthur M. Mercurio, Aydin Tozeren Nov 2010

Role Of E-Cadherin In The Response Of Tumor Cell Aggregates To Lymphatic, Venous And Arterial Flow: Measurement Of Cell-Cell Adhesion Strength, Stephen W. Byers, Connie L. Sommers, Becky Hoxter, Arthur M. Mercurio, Aydin Tozeren

Arthur M. Mercurio

Defects in the expression or function of the calcium dependent cell-cell adhesion molecule E-cadherin are common in invasive, metastatic carcinomas. In the present study the response of aggregates of breast epithelial cells and breast and colon carcinoma cells to forces imposed by laminar flow in a parallel plate flow channel was examined. Although E-cadherin negative tumor cells formed cell aggregates in the presence of calcium, these were significantly more likely than E-cadherin positive cell aggregates to disaggregate in response to low shear forces, such as those found in a lymphatic vessel or venule (< 3.5 dyn/cm2). E-cadherin positive normal breast epithelial cells and E-cadherin positive breast tumor cell aggregates could not be disaggregated when exposed to shear forces in excess of those found in arteries (> 100 dyn/cm2). E-cadherin negative cancer cells …


Regulation Of Cellular Interactions With Laminin By Integrin Cytoplasmic Domains: The A And B Structural Variants Of The Alpha 6 Beta 1 Integrin Differentially Modulate The Adhesive Strength, Morphology, And Migration Of Macrophages, Leslie M. Shaw, Arthur M. Mercurio Nov 2010

Regulation Of Cellular Interactions With Laminin By Integrin Cytoplasmic Domains: The A And B Structural Variants Of The Alpha 6 Beta 1 Integrin Differentially Modulate The Adhesive Strength, Morphology, And Migration Of Macrophages, Leslie M. Shaw, Arthur M. Mercurio

Arthur M. Mercurio

Several integrin alpha subunits have structural variants that are identical in their extracellular and transmembrane domains but that differ in their cytoplasmic domains. The functional significance of these variants, however, is unknown. In the present study, we examined the possibility that the A and B variants of the alpha 6 beta 1 integrin laminin receptor differ in function. For this purpose, we expressed the alpha 6A and alpha 6B cDNAs, as well as a truncated alpha 6 cDNA (alpha 6-delta CYT) in which the cytoplasmic domain sequence was deleted after the GFFKR pentapeptide, in P388D1 cells, an alpha 6 deficient …


Adam12 Induces Actin Cytoskeleton And Extracellular Matrix Reorganization During Early Adipocyte Differentiation By Regulating Beta1 Integrin Function, Nobuko Kawaguchi, Christina Sundberg, Marie Kveiborg, Behzad Moghadaszadeh, Meena Asmar, Nikolaj Dietrich, Charles Kumar Thodeti, Finn C. Nielsen, Peter Moller, Arthur M. Mercurio, Reidar Albrechtsen, Ulla M. Wewer Nov 2010

Adam12 Induces Actin Cytoskeleton And Extracellular Matrix Reorganization During Early Adipocyte Differentiation By Regulating Beta1 Integrin Function, Nobuko Kawaguchi, Christina Sundberg, Marie Kveiborg, Behzad Moghadaszadeh, Meena Asmar, Nikolaj Dietrich, Charles Kumar Thodeti, Finn C. Nielsen, Peter Moller, Arthur M. Mercurio, Reidar Albrechtsen, Ulla M. Wewer

Arthur M. Mercurio

Changes in cell shape are a morphological hallmark of differentiation. In this study we report that the expression of ADAM12, a disintegrin and metalloprotease, dramatically affects cell morphology in preadipocytes, changing them from a flattened, fibroblastic appearance to a more rounded shape. We showed that the highest levels of ADAM12 mRNA were detected in preadipocytes at the critical stage when preadipocytes become permissive for adipogenic differentiation. Furthermore, as assessed by immunostaining, ADAM12 was transiently expressed at the cell surface concomitant with the reduced activity of beta1 integrin. Co-immunoprecipitation studies indicated the formation of ADAM12/beta1 integrin complexes in these preadipocytes. Overexpression …


Regulation Of Alpha 6 Beta 1 Integrin Laminin Receptor Function By The Cytoplasmic Domain Of The Alpha 6 Subunit, Leslie M. Shaw, Arthur M. Mercurio Nov 2010

Regulation Of Alpha 6 Beta 1 Integrin Laminin Receptor Function By The Cytoplasmic Domain Of The Alpha 6 Subunit, Leslie M. Shaw, Arthur M. Mercurio

Arthur M. Mercurio

The alpha 6 beta 1 integrin is expressed on the macrophage surface in an inactive state and requires cellular activation with PMA or cytokines to function as a laminin receptor (Shaw, L. M., J. M. Messier, and A. M. Mercurio. 1990. J. Cell Biol. 110:2167-2174). In the present study, the role of the alpha 6 subunit cytoplasmic domain in alpha 6 beta 1 integrin activation was examined. The use of P388D1 cells, an alpha 6-integrin deficient macrophage cell line, facilitated this analysis because expression of either the alpha 6A or alpha 6B subunit cDNAs restores their activation responsive laminin adhesion …


Transcriptional Activation Of Integrin Beta6 During The Epithelial-Mesenchymal Transition Defines A Novel Prognostic Indicator Of Aggressive Colon Carcinoma, Richard C. Bates, David I. Bellovin, Courtney Brown, Elizabeth Maynard, Bingyan Wu, Hisaaki Kawakatsu, Dean Sheppard, Peter Oettgen, Arthur M. Mercurio Nov 2010

Transcriptional Activation Of Integrin Beta6 During The Epithelial-Mesenchymal Transition Defines A Novel Prognostic Indicator Of Aggressive Colon Carcinoma, Richard C. Bates, David I. Bellovin, Courtney Brown, Elizabeth Maynard, Bingyan Wu, Hisaaki Kawakatsu, Dean Sheppard, Peter Oettgen, Arthur M. Mercurio

Arthur M. Mercurio

We used a spheroid model of colon carcinoma to analyze integrin dynamics as a function of the epithelial-mesenchymal transition (EMT), a process that provides a paradigm for understanding how carcinoma cells acquire a more aggressive phenotype. This EMT involves transcriptional activation of the beta6 integrin subunit and a consequent induction of alphavbeta6 expression. This integrin enhances the tumorigenic properties of colon carcinoma, including activation of autocrine TGF-beta and migration on interstitial fibronectin. Importantly, this study validates the clinical relevance of the EMT. Kaplan-Meier analysis of beta6 expression in 488 colorectal carcinomas revealed a striking reduction in median survival time of …