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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 …

Alcohol-Induced Il-1beta In The Brain Is Mediated By Nlrp3/Asc Inflammasome Activation That Amplifies Neuroinflammation, Dora Lippai, Shashi Bala, Jan Petrasek, Timea Csak, Ivan Levin, Evelyn Kurt-Jones, Gyongyi Szabo

Gyongyi Szabo

Alcohol-induced neuroinflammation is mediated by proinflammatory cytokines, including IL-1beta. IL-1beta production requires caspase-1 activation by inflammasomes-multiprotein complexes that are assembled in response to danger signals. We hypothesized that alcohol-induced inflammasome activation contributes to increased IL-1beta in the brain. WT and TLR4-, NLRP3-, and ASC-deficient (KO) mice received an ethanol-containing or isocaloric control diet for 5 weeks, and some received the rIL-1ra, anakinra, or saline treatment. Inflammasome activation, proinflammatory cytokines, endotoxin, and HMGB1 were measured in the cerebellum. Expression of inflammasome components (NLRP1, NLRP3, ASC) and proinflammatory cytokines (TNF-alpha, MCP-1) was increased in brains of alcohol-fed compared with control mice. Increased …

Reduction In Hepatic Inflammation Is Associated With Less Fibrosis Progression And Fewer Clinical Outcomes In Advanced Hepatitis C, Chihiro Morishima, Mitchell Shiffman, Jules Dienstag, Karen Lindsay, Gyongyi Szabo, Gregory Everson, Anna Lok, Adrian Di Bisceglie, Marc Ghany, Deepa Naishadham, Timothy Morgan, Elizabeth Wright

Gyongyi Szabo

OBJECTIVES:During the Hepatitis C Antiviral Long-term Treatment against Cirrhosis Trial, 3.5 years of maintenance peginterferon-alfa-2a therapy did not affect liver fibrosis progression or clinical outcomes among 1,050 previous interferon nonresponders with advanced fibrosis or cirrhosis. We investigated whether reduced hepatic inflammation was associated with clinical benefit in 834 patients with a baseline and follow-up biopsy 1.5 years after randomization to peginterferon or observation. METHODS:Relationships between change in hepatic inflammation (Ishak hepatic activity index, (HAI)) and serum alanine aminotransferase level, fibrosis progression and clinical outcomes after randomization, and hepatitis C virus (HCV) RNA decline before and after randomization were evaluated. Histological …

Type I Interferons Protect From Toll-Like Receptor 9-Associated Liver Injury And Regulate Il-1 Receptor Antagonist In Mice, Jan Petrasek, Angela Dolganiuc, Timea Csak, Evelyn Kurt-Jones, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND and AIMS: Liver inflammation and injury are mediated by the innate immune response, which is regulated by Toll-like receptors (TLR). Activation of TLR9 induces type I interferons (IFNs) via the interferon regulatory factor (IRF)-7. We investigated the roles of type I IFNs in TLR9-associated liver injury. METHODS: Wild-type (WT), IRF7-deficient, and IFN-alpha/beta receptor 1 (IFNAR1)-deficient mice were stimulated with TLR9 or TLR2 ligands. Findings from mice were verified in cultured hepatocytes and liver mononuclear cells (LMNCs) as well as in vivo experiments using recombinant type I IFN and interleukin-1 receptor antagonist (IL-1ra). RESULTS: Type I IFNs were up-regulated during …

The Opposite Effects Of Acute And Chronic Alcohol On Lipopolysaccharide-Induced Inflammation Are Linked To Irak-M In Human Monocytes, Pranoti Mandrekar, Shashi Bala, Donna Catalano, Karen Kodys, Gyongyi Szabo

Gyongyi Szabo

Impaired host defense after alcohol use is linked to altered cytokine production, however, acute and chronic alcohol differently modulate monocyte/macrophage activation. We hypothesized that in human monocytes, acute alcohol induces hyporesponsiveness to LPS, resulting in decreased TNF-alpha, whereas chronic alcohol increases TNF-alpha by sensitization to LPS. We found that acute alcohol increased IL-1R-associated kinase-monocyte (IRAK-M), a negative regulator of IRAK-1, in human monocytes. This was associated with decreased IkappaB alpha kinase activity, NFkappaB DNA binding, and NFkappaB-driven reporter activity after LPS stimulation. In contrast, chronic alcohol decreased IRAK-M expression but increased IRAK-1 and IKK kinase activities, NFkappaB DNA binding, and …

Innate Immune Response And Hepatic Inflammation, Gyongyi Szabo, Pranoti Mandrekar, Angela Dolganiuc

Gyongyi Szabo

Inflammation is a pathogenic component of various types of acute and chronic liver diseases, and it contributes to progressive liver damage and fibrosis. Cells of the innate immune system initiate and maintain hepatic inflammation though mediator production as a result of their activation by pathogen-derived products recognized by pattern recognition receptors. Innate immune cells, particularly dendritic cells, have a pivotal role in sensing pathogens and initiating adaptive immune responses by activation and regulation of T-lymphocyte responses. Although the liver provides a "tolerogenic" immune environment for antigen-specific T-cells, activation of Kupffer cells, recruited macrophages, and inflammatory cells results in production of …

Bone Marrow-Derived Immune Cells Mediate Sensitization To Liver Injury In A Myeloid Differentiation Factor 88-Dependent Fashion, Istvan Hritz, Arumugam Velayudham, Angela Dolganiuc, Karen Kodys, Pranoti Mandrekar, Evelyn Kurt-Jones, Gyongyi Szabo

Gyongyi Szabo

Toll-like receptors (TLRs) expressed on both immune cells and hepatocytes recognize microbial danger signals and regulate immune responses. Previous studies showed that TLR9 and TLR2 mediate Propionibacterium acnes-induced sensitization to lipopolysaccharide-triggered acute liver injury in mice. Ligand-specific activation of TLR2 and TLR9 are dependent on the common TLR adaptor, myeloid differentiation factor 88 (MyD88). Here, we dissected the role of MyD88 in parenchymal and bone marrow (BM)-derived cells in liver sensitization. Using chimeric mice with green fluorescent protein-expressing BM cells, we identified that P. acnes-induced liver inflammatory foci are of BM origin. Chimeras with MyD88-deficient BM showed no inflammatory foci …

Moderate Drinking, Inflammation, And Liver Disease, Gyongyi Szabo

Gyongyi Szabo

It is well known that heavy drinking increases the risk of alcohol-related liver disease (ALD). Female gender, hepatitis C or B, obesity, and other cofactors increase susceptibility to ALD, so “safe” levels of alcohol consumption in regard to ALD vary among individuals. Inflammation is one mechanism by which alcohol causes liver damage. Increasing evidence suggests that in contrast to the proinflammatory activation by chronic excessive alcohol consumption, acute moderate alcohol administration has anti-inflammatory effects. Long-term alcohol administration results in increased baseline nuclear regulatory factor κB (NF-κB) activation in the livers of mice; in contrast, acute alcohol administration in mice attenuates …

A Recent Perspective On Alcohol, Immunity, And Host Defense, Gyongyi Szabo, Pranoti Mandrekar

Gyongyi Szabo

BACKGROUND: Multiple line of clinical and experimental evidence demonstrates that both acute, moderate, and chronic, excessive alcohol use result in various abnormalities in the functions of the immune system.

METHODS: Medline and PubMed databases were used to identify published reports with particular interest in the period of 2000-2008 in the subject of alcohol use, infection, inflammation, innate, and adaptive immunity.

RESULTS: This review article summarizes recent findings relevant to acute or chronic alcohol use-induced immunomodulation and its consequences on host defense against microbial pathogens and tissue injury. Studies with in vivo and in vitro alcohol administration are both discussed. The …

Hepatitis C Core And Nonstructural 3 Proteins Trigger Toll-Like Receptor 2-Mediated Pathways And Inflammatory Activation, Angela Dolganiuc, Shilpa Oak, Karen Kodys, Douglas Golenbock, Robert Finberg, Evelyn Kurt-Jones, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND AND AIMS: Recent evidence suggests that toll-like receptors (TLRs) recognize certain viruses. We reported that hepatitis C virus (HCV) core and nonstructural 3 (NS3) proteins activate inflammatory pathways in monocytes. The aim of this study was to investigate the role of TLRs in innate immune cell activation by core and NS3 proteins. METHODS: Human monocytes, human embryonic kidney cells transfected with TLR2, and peritoneal macrophages from TLR2, MyD88 knockout, and wild-type mice were studied to determine intracellular signaling and proinflammatory cytokine induction by HCV proteins. RESULTS: HCV core and NS3 proteins triggered inflammatory cell activation via the pattern recognition …

Viral And Host Factors Induce Macrophage Activation And Loss Of Toll-Like Receptor Tolerance In Chronic Hcv Infection, Angela Dolganiuc, Oxana Norkina, Karen Kodys, Donna Catalano, Gennadiy Bakis, Christopher Marshall, Pranoti Mandrekar, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND and AIMS: Persistent inflammation contributes to progression of liver damage in chronic HCV (cHCV) infection. Repeated exposure to toll-like receptor (TLR) ligands results in tolerance, a protective mechanism aimed at limiting inflammation.

METHODS: Monocytes/macrophages were repeatedly stimulated via proinflammatory cytokine-inducing TLRs and evaluated for activation markers.

RESULTS: Unlike monocytes of controls or patients with nonalcoholic steatohepatitis, the monocytes of cHCV patients were hyperresponsive and failed to show homo- or heterotolerance to TLR ligands, manifested by elevated tumor necrosis factor (TNF)-alpha production. Serum levels of interferon (IFN)-gamma, endotoxin (TLR4 ligand), and HCV core protein (TLR2 ligand) were elevated in cHCV …

Microrna Expression Profile In Lieber-Decarli Diet-Induced Alcoholic And Methionine Choline Deficient Diet-Induced Nonalcoholic Steatohepatitis Models In Mice, Angela Dolganiuc, Jan Petrasek, Karen Kodys, Donna Catalano, Pranoti Mandrekar, Arumugam Velayudham, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND: Alcoholic and nonalcoholic steatohepatitis are leading causes of liver diseases worldwide. While of different etiology, these share common pathophysiological mechanisms and feature abnormal fat metabolism, inflammation and fibrosis. MicroRNAs (miRNA) are highly conserved noncoding RNAs that control gene expression at the post-transcriptional level either via the degradation of target mRNAs or the inhibition of translation. Each miRNA controls the expression of multiple targets; miRNAs have been linked to regulation of lipid metabolism and inflammation. METHODS: We fed Lieber-DeCarli alcohol or methionine-choline-deficient (MCD) diets to C57Bl6 and analyzed livers for histopathology, cytokines by ELISA, alanine aminotransferase (ALT) by biochemical assay, …

Acute Alcohol Exposure Exerts Anti-Inflammatory Effects By Inhibiting Ikappab Kinase Activity And P65 Phosphorylation In Human Monocytes, Pranoti Mandrekar, Valentina Jeliazkova, Donna Catalano, Gyongyi Szabo

Gyongyi Szabo

Acute alcohol use is associated with impaired immune responses and decreased proinflammatory cytokine production. Our earlier studies have shown that acute alcohol intake inhibits NF-kappaB DNA binding in an IkappaBalpha-independent manner. We report using human peripheral blood monocytes and Chinese hamster ovary cells transfected with CD14 cells that acute alcohol treatment in vitro exerts NF-kappaB inhibition by disrupting phosphorylation of p65. Immunoprecipitation of p65 and IkappaBalpha revealed that acute alcohol exposure for 1 h decreased NF-kappaB-IkappaBalpha complexes in the cytoplasm. Phosphorylation of p65 at Ser(536) is mediated by IkappaB kinase (IKK)beta and is required for NF-kappaB-dependent cellular responses. We show …

Tlr2- And Tlr4-Mediated Signals Determine Attenuation Or Augmentation Of Inflammation By Acute Alcohol In Monocytes, Shilpa Oak, Pranoti Mandrekar, Donna Catalano, Karen Kodys, Gyongyi Szabo

Gyongyi Szabo

Most pathogens express ligands for multiple TLRs that share common downstream signaling. In this study, we investigated the effects of acute alcohol on inflammatory pathways induced by TLR2 or TLR4 ligands and their combination. In human monocytes, alcohol attenuated TLR4- but not TLR2-induced TNF-alpha protein and mRNA levels and NF-kappaB activation. In contrast, acute alcohol augmented TNF-alpha production when both TLR2 and TLR4 ligands were present. IL-1R-associated kinase (IRAK)-1 activity was reduced by alcohol in TLR4, but it was augmented in TLR2- plus TLR4-stimulated cells. IRAK-monocyte, an inhibitor of IRAK-1, was induced in TLR4, but it was reduced in TLR2- …