Life Sciences Commons^™

Association Of Circulating Mtdna With Cvd In Hemodialysis Patients And In Vitro Effect Of Exogenous Mtdna On Cardiac Microvascular Inflammation, Zhen Fan, Ya Feng, Li Zang, Yi Guo, Xiao-Yi Zhong

Student and Faculty Publications

BACKGROUND: Chronic kidney disease (CKD) patients sustain a fairly high prevalence of cardiovascular disease (CVD). Microvascular inflammation is an early manifestation of CVD, and the released mitochondrial DNA (MtDNA) has been proposed to be a crucial integrator of inflammatory signals. Herein, the aim of this study was to determine the relationship between CVD, microvessel, and circulating MtDNA in the settings of uremia.

METHODS: Forty-two maintenance hemodialysis (MHD) patients and 36 health controls were enrolled in this study. Plasma cell-free MtDNA was detected by TaqMan-based qPCR assay. CVD risk markers including high-sensitive C-reactive protein (Hs-CRP), monocyte chemoattractant protein-1 (MCP-1), fibrinogen, and …

Type 1 Diabetes Alters Lipid Handling And Metabolism In Human Fibroblasts And Peripheral Blood Mononuclear Cells, Albert R. Jones Iv, Emily L. Coleman, Nicholas R. Husni, Jude T. Deeney, Forum Raval, Devin Steenkamp, Hans Dooms, Barbara S. Nikolajczyk, Barbara E. Corkey

Clinical and Translational Science Faculty Publications

Triggers of the autoimmune response that leads to type 1 diabetes (T1D) remain poorly understood. A possibility is that parallel changes in both T cells and target cells provoke autoimmune attack. We previously documented greater Ca²⁺ transients in fibroblasts from T1D subjects than non-T1D after exposure to fatty acids (FA) and tumor necrosis factor α (TNFα). These data indicate that metabolic and signal transduction defects present in T1D can be elicited ex vivo in isolated cells. Changes that precede T1D, including inflammation, may activate atypical responses in people that are genetically predisposed to T1D. To identify such cellular differences …

Sustained Sensitizing Effects Of Tumor Necrosis Factor Alpha On Sensory Nerves In Lung And Airways, Ruei-Lung Lin, Qihai Gu, Mehdi Khosravi, Lu-Yuan Lee

Physiology Faculty Publications

Tumor necrosis factor alpha (TNFα) plays a significant role in the pathogenesis of airway inflammatory diseases. Inhalation of aerosolized TNFα induced airway hyperresponsiveness accompanied by airway inflammation in healthy human subjects, but the underlying mechanism is not fully understood. We recently reported a series of studies aimed to investigate if TNFα elevates the sensitivity of vagal bronchopulmonary sensory nerves in a mouse model; these studies are summarized in this mini-review. Our results showed that intratracheal instillation of TNFα induced pronounced airway inflammation 24 hours later, as illustrated by infiltration of eosinophils and neutrophils and the release of inflammatory mediators and …

The Tnfα-Transgenic Rat: Hippocampal Synaptic Integrity, Cognition, Function, And Post-Ischemic Cell Loss, L. Creed Pettigrew, Richard J. Kryscio, Christopher M. Norris

Sanders-Brown Center on Aging Faculty Publications

The cytokine, tumor necrosis factor α (TNFα), is a key regulator of neuroinflammation linked to numerous neurodegenerative conditions and diseases. The present study used transgenic rats that overexpress a murine TNFα gene, under the control of its own promoter, to investigate the impact of chronically elevated TNFα on hippocampal synaptic function. Neuronal viability and cognitive recovery in TNFα Tg rats were also determined following an ischemic insult arising from reversible middle cerebral artery occlusion (MCAO). Basal CA3-CA1 synaptic strength, recorded in acute brain slices, was not significantly different between eight-week-old TNFα Tg rats and non-Tg rats. In contrast, slices from …

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 …

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 …

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 …

Inhibition Of Tlr8- And Tlr4-Induced Type I Ifn Induction By Alcohol Is Different From Its Effects On Inflammatory Cytokine Production In Monocytes, Maoyin Pang, Shashi Bala, Karen Kodys, Donna Catalano, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND: Prolonged alcohol consumption is a significant co-factor in the progression of chronic viral infections including hepatitis C and HIV, which are both single-stranded RNA viruses. Toll like receptor 8 (TLR8), a pattern recognition receptor expressed in monocytes, senses viral single stranded RNA as a danger signal and leads to the induction of Type I interferon (IFN) as well as the pro-inflammatory cytokine, tumor necrosis factor alpha (TNF alpha). Lipopolysaccharide (LPS), a Toll like receptor 4 (TLR4) ligand, was shown to affect inflammatory cell activation after alcohol consumption and in HIV and HCV infections. Here we hypothesized that alcohol exposure …

Aberrations In Post-Trauma Monocyte (Mo) Subpopulation: Role In Septic Shock Syndrome, Carol Miller-Graziano, Gyongyi Szabo, Karen Kodys, Katherine Griffey

Gyongyi Szabo

Appearance of increased proportions of monocytes bearing the 72kd(FcRI) receptor for IgG correlated to aberrant monocyte (MO) functions, depressed immune functions, and poor clinical outcome. The trauma patients' FcRI+ MO subpopulation produced the majority of their elevated IL-6, TNF alpha, TGF beta, and PGE2. IgG stimulation of patients' MO through FcRI not only stimulated TNF alpha, IL-6, and PGE2 levels, but also greatly augmented the levels of these monokines produced after subsequent bacterial challenge. Post-trauma increased IL-6 levels can lead to polyclonal B-cell activation and high levels of circulating, nonspecific IgG as seen in trauma patients. This nonspecific IgG triggers …

Effect Of Ethanol On Inflammatory Responses. Implications For Pancreatitis, Gyongyi Szabo, Pranoti Mandrekar, Shilpa Oak, Julia Mayerle

Gyongyi Szabo

BACKGROUND/AIMS: Alcohol use alters inflammatory cell responses. While alcohol has direct effects on pancreatic acinar cells, activation of inflammatory cells is a major component of the pathology of alcoholic pancreatitis.

METHODS: The effects of acute or chronic alcohol exposure were evaluated in human monocytes on the production of TNFalpha or IL-10 production, pro-inflammatory gene and nuclear factor-kappaB (NF-kappaB) activation.

RESULTS: Moderate, acute alcohol consumption or equivalent doses of alcohol in vitro had anti-inflammatory effects on monocyte activation via inhibition of pro-inflammatory genes and NF-kappaB activation, inhibition of TNFalpha production and augmentation of the anti-inflammatory cytokine, IL-10. In contrast, acute alcohol …

Induction And Regulation Of Monocyte Procoagulant Activity, Gyongyi Szabo, Carol Miller-Graziano

Gyongyi Szabo

Monocyte (MO) procoagulant activity (PCA) is induced by various stimuli including allogeneic stimulation, immunocomplexes, and bacterial products. Antigen-antibody complex stimulation therefore represents a pathway for MO PCA induction. Activation of MO PCA has been demonstrated in immunocomplex disease and could represent a major pathology in transplanted immunocomplex disease patients. Stimulation of monocytes via their FcRI receptor has been demonstrated to induce TNF and PGE2. This report demonstrates that stimulation of the high-density FcRI receptor-bearing (FcRI+) MO by resetting with anti-Rh coated erythrocytes also induces significant PCA levels (P less than 0.001). Muramyl dipeptide (MDP), a Gram-positive bacterial cell wall analogue, …

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 …

Increased Lipopolysaccharide Sensitivity In Alcoholic Fatty Livers Is Independent Of Leptin Deficiency And Toll-Like Receptor 4 (Tlr4) Or Tlr2 Mrna Expression, Laszlo Romics, Pranoti Mandrekar, Karen Kodys, Arumugam Velayudham, Yvonne Drechsler, Angela Dolganiuc, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND: Both alcoholic (AFL) and nonalcoholic (NAFL) fatty livers show increased sensitivity to endotoxin-induced injury. Lipopolysaccharide (LPS) is recognized by toll-like receptor 4 (TLR4), whereas lipopeptide triggers TLR2 to induce common downstream activation of nuclear factor (NF)-kappaB and pro-inflammatory pathways that are activated in AFL and NAFL. METHODS: Serum alanine aminotransferase (ALT), tumor necrosis factor (TNF)-alpha, and interleukin (IL)-6 levels; hepatic NF-kappaB activity; and expression of TLR2, TLR4, inducible nitric oxide synthase (iNOS), and heme oxygenase (HO)-1 mRNAs were investigated in lean and leptin-deficient ob/ob mice after LPS challenge in combination with acute or chronic alcohol feeding. RESULTS: Increased LPS …

Elevated Tumor Necrosis Factor Alpha Production Concomitant To Elevated Prostaglandin E2 Production By Trauma Patients' Monocytes, Thomas Takayama, Carol Miller-Graziano, Gyongyi Szabo

Gyongyi Szabo

The level of tumor necrosis factor alpha (TNF alpha), a monokine implicated in mediating septic shock, is elevated in the blood of some patients with sepsis. Monocytes from 11 trauma patients and 11 burn patients were suboptimally stimulated with interferon gamma and muramyl dipeptide, an analogue of bacterial wall products. The patients with sepsis showed significantly greater total TNF alpha levels (secreted in combination with cell-associated) 3 days before septic episodes, as compared with normal controls (32.38 to 2231.76 ng/10(6) monocytes per milliliter, median = 121.03 ng/10(6) monocytes per milliliter; normal control: 0.00 to 18.20 ng/10(6) monocytes per milliliter, median …

Regulation Of Human Monocyte Functions By Acute Ethanol Treatment: Decreased Tumor Necrosis Factor-Alpha, Interleukin-1 Beta And Elevated Interleukin-10, And Transforming Growth Factor-Beta Production, Gyongyi Szabo, Pranoti Mandrekar, Linda Girouard, Donna Catalano

Gyongyi Szabo

We and others have previously shown that even acute ethanol exposure has the capacity to modulate immune functions, particularly monocyte functions. Herein, we tested the hypothesis that acute ethanol treatment inhibits inflammatory, while increasing inhibitory cytokine production in human blood monocytes that, in turn, could contribute to the overall immune abnormalities seen after alcohol use. Our data show that in vitro treatment of blood monocytes with a physiologically relevant dose of alcohol (25 mM) results in significantly decreased induction of tumor necrosis factor-alpha (TNF alpha) and interleukin (IL)-1 beta by bacterial stimulation of either Gram-positive [staphylococcal enterotoxin B (SEB), 1 …

Ethanol-Mediated Regulation Of Transcription Factors In Immunocompetent Cells, Gyongyi Szabo, Pranoti Mandrekar

Gyongyi Szabo

The immunomodulatory effects of acute and chronic alcohol use are characterized by impaired antigen-specific immune activation and by increased susceptibility to infections due to alterations in innate immune responses and inflammatory mediator production. The central feature of cellular responses to inflammatory and stress signals is the activation of the nuclear regulatory kappa B/Rel family of transcriptional factors via various surface receptor systems in immunocompetent cells. Activation of NF-kappa B, however, is regulated at multiple levels including I-kappa B degradation, nuclear translocation, and by interaction of NF-kappa B/Rel with other transcription factors. Data from our and other laboratories demonstrate that acute …

Modulation Of Non-Alcoholic Steatohepatitis By Pattern Recognition Receptors In Mice: The Role Of Toll-Like Receptors 2 And 4, Gyongyi Szabo, Arumugam Velayudham, Laszlo Romics, Pranoti Mandrekar

Gyongyi Szabo

Toll-like receptors (TLR) recognize pathogen-derived molecules and induce downstream activation of inflammatory pathways. Fatty liver has been shown to result in increased sensitivity to lipopolysaccharide (LPS), a TLR4 ligand. In this study, we investigated the roles of TLR2 and TLR4 in liver damage and on cytokine induction in a methionine-choline deficient (MCD) diet-induced model of nonalcoholic steatohepatitis. We found that mice with nonalcoholic fatty liver had increased liver injury and inflammatory cytokine induction after challenge with a TLR4 but not with a TLR2 ligand. TLR2 deficient mice were not protected against the development of steatohepatitis after MCD diet feeding. On …

The Critical Role Of Toll-Like Receptor (Tlr) 4 In Alcoholic Liver Disease Is Independent Of The Common Tlr Adapter Myd88, Istvan Hritz, Pranoti Mandrekar, Arumugam Velayudham, Donna Catalano, Angela Dolganiuc, Karen Kodys, Evelyn Kurt-Jones, Gyongyi Szabo

Gyongyi Szabo

The Toll-like receptor 4 (TLR4) that recognizes endotoxin, a trigger of inflammation in alcoholic liver disease (ALD), activates two signaling pathways utilizing different adapter molecules: the common TLR adapter, myeloid differentiation factor 88 (MyD88), or Toll/interleukin immune-response-domain-containing adaptor inducing interferon (IFN)-beta. The MyD88 pathway induces proinflammatory cytokine activation, a critical mediator of ALD. Here we evaluated the role of MyD88 in alcohol-induced liver injury in wild-type, TLR2-deficient, TLR4-deficient, or MyD88-deficient (knockout [KO]) mice after administration of the Lieber-De-Carli diet (4.5% volume/volume ethanol) or an isocaloric liquid control diet for 5 weeks. Alcohol feeding resulted in a significant increase in serum …