scholarly journals Administration of Escherichia coli endotoxin to rat increases liver mass and hepatocyte volume in vivo

1996 ◽  
Vol 313 (2) ◽  
pp. 479-486 ◽  
Author(s):  
Dalong QIAN ◽  
John T. BROSNAN
Keyword(s):  
Escherichia Coli ◽  
Intraperitoneal Administration ◽  
Polyclonal Antiserum ◽  
Metabolic Effects ◽  
Morphometric Study ◽  
Liver Mass ◽  
Hepatic Mass ◽  
Tnf Α ◽  
Factor Α

We have established, in vivo, an increase in liver mass and hepatocyte volume after a single intraperitoneal administration, to fasted rats, of Escherichia coli lipopolysaccharide (0127:B8) at 3 mg/kg. The phenomenon was time- and dose-dependent and could be prevented by treatment with polyclonal antiserum against tumour necrosis factor-α (TNF-α) before the endotoxin injection. Endotoxin caused an increase of 26% in the hepatic mass compared with fasted controls at 24 h. An increase of 27% in the hepatic water content underlay the altered hepatic mass which could not be accounted for by a change in the volume of hepatic blood and/or interstitial fluid (measured in vivo), suggesting an expansion in the hepatocellular volume. This is supported by an increase of 25% in the K+ content of the endotoxic livers. Morphometric study confirmed a 15% increase in hepatocyte volume after endotoxin administration. The data are discussed in the light of possible metabolic effects of increased hepatocyte volume.

scholarly journals L-Selectin–Dependent Leukocyte Adhesion to Microvascular But Not to Macrovascular Endothelial Cells of the Human Coronary System

Blood ◽  
1997 ◽  
Vol 89 (9) ◽  
pp. 3228-3235 ◽  
Author(s):  
A. Zakrzewicz ◽  
M. Gräfe ◽  
D. Terbeek ◽  
M. Bongrazio ◽  
W. Auch-Schwelk ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Time Course ◽  
Leukocyte Adhesion ◽  
Flow Chamber ◽  
Shear Stresses ◽  
Selectin Ligands ◽  
Tnf Α ◽  
Factor Α

Abstract To characterize L-selectin–dependent cell adhesion to human vascular endothelium, human cardiac microvascular endothelial cells (HCMEC) and human coronary endothelial cells (HCEC) were isolated from explanted human hearts. The adhesion behavior of human (NALM-6) and mouse (300.19) pre-B cells transfected with cDNA encoding for human L-selectin was compared with that of the respective nontransfected cells in a flow chamber in vitro. More than 80% of the adhesion to tumor necrosis factor-α (TNF-α)–stimulated HCMEC at shear stresses <2 dyne/cm2 was L-selectin dependent and could be equally well blocked by an anti–L-selectin antibody or a L-selectin-IgG-chimera. No L-selectin dependent adhesion to HCEC could be shown. The L-selectin dependent adhesion to HCMEC was insensitive to neuraminidase, but greatly inhibited by addition of NaClO3 , which inhibits posttranslational sulfation and remained elevated for at least 24 hours of stimulation. E-selectin dependent adhesion of HL60 cells to HCMEC was blocked by neuraminidase, but not by NaClO3 and returned to control levels within 18 hours of HCMEC stimulation. It is concluded that microvascular, but not macrovascular endothelial cells express TNF-α–inducible sulfated ligand(s) for L-selectin, which differ from known L-selectin ligands, because sialylation is not required. The prolonged time course of L-selectin dependent adhesion suggests a role in sustained leukocyte recruitment into inflammatory sites in vivo.

scholarly journals Repetitive Injections of Dendritic Cells Matured with Tumor Necrosis Factor α Induce Antigen-specific Protection of Mice from Autoimmunity

2001 ◽  
Vol 195 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Mauritius Menges ◽  
Susanne Rößner ◽  
Constanze Voigtländer ◽  
Heike Schindler ◽  
Nicole A. Kukutsch ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Cell Immunity ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

Mature dendritic cells (DCs) are believed to induce T cell immunity, whereas immature DCs induce T cell tolerance. Here we describe that injections of DCs matured with tumor necrosis factor (TNF)-α (TNF/DCs) induce antigen-specific protection from experimental autoimmune encephalomyelitis (EAE) in mice. Maturation by TNF-α induced high levels of major histocompatibility complex class II and costimulatory molecules on DCs, but they remained weak producers of proinflammatory cytokines. One injection of such TNF/DCs pulsed with auto-antigenic peptide ameliorated the disease score of EAE. This could not be observed with immature DCs or DCs matured with lipopolysaccharide (LPS) plus anti-CD40. Three consecutive injections of peptide-pulsed TNF/DCs derived from wild-type led to the induction of peptide-specific predominantly interleukin (IL)-10–producing CD4+ T cells and complete protection from EAE. Blocking of IL-10 in vivo could only partially restore the susceptibility to EAE, suggesting an important but not exclusive role of IL-10 for EAE prevention. Notably, the protection was peptide specific, as TNF/DCs pulsed with unrelated peptide could not prevent EAE. In conclusion, this study describes that stimulation by TNF-α results in incompletely matured DCs (semi-mature DCs) which induce peptide-specific IL-10–producing T cells in vivo and prevent EAE.

scholarly journals Effect of the proinflammatory cytokine TNF-α on intestinal riboflavin uptake: inhibition mediated via transcriptional mechanism(s)

2018 ◽  
Vol 315 (5) ◽  
pp. C653-C663 ◽  
Author(s):  
Kasin Yadunandam Anandam ◽  
Omar A. Alwan ◽  
Veedamali S. Subramanian ◽  
Padmanabhan Srinivasan ◽  
Rubina Kapadia ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Significant Inhibition ◽  
Mrna Levels ◽  
In Vivo Models ◽  
Uptake Inhibition ◽  
Tnf Α ◽  
Vitro Model ◽  
Factor Α

Riboflavin (RF), is essential for normal cellular metabolism/function. Intestinal RF absorption occurs via a specific carrier-mediated process that involves the apical transporter RFVT-3 ( SLC52A3) and the basolateral RFVT-1 (SLC52A1). Previously, we characterized different cellular/molecular aspects of the intestinal RF uptake process, but nothing is known about the effect of proinflammatory cytokines on the uptake event. We addressed this issue using in vitro, ex vivo, and in vivo models. First, we determined the level of mRNA expression of the human (h)RFVT-3 and hRFVT-1 in intestinal tissue of patients with inflammatory bowel disease (IBD) and observed a markedly lower level compared with controls. In the in vitro model, exposing Caco-2 cells to tumor necrosis factor-α (TNF-α) led to a significant inhibition in RF uptake, an effect that was abrogated upon knocking down TNF receptor 1 (TNFR1). The inhibition in RF uptake was associated with a significant reduction in the expression of hRFVT-3 and -1 protein and mRNA levels, as well as in the activity of the SLC52A3 and SLC52A1 promoters. The latter effects appear to involve Sp1 and NF-κB sites in these promoters. Similarly, exposure of mouse small intestinal enteroids and wild-type mice to TNF-α led to a significant inhibition in physiological and molecular parameters of intestinal RF uptake. Collectively, these findings demonstrate that exposure of intestinal epithelial cells to TNF-α leads to inhibition in RF uptake and that this effect is mediated, at least in part, via transcriptional mechanism(s). These findings may explain the significantly low RF levels observed in patients with IBD.

TNF-α and myocardial depression in endotoxemic rats: temporal discordance of an obligatory relationship

1998 ◽  
Vol 275 (2) ◽  
pp. R502-R508 ◽  
Author(s):  
Xianzhong Meng ◽  
Lihua Ao ◽  
Daniel R. Meldrum ◽  
Brian S. Cain ◽  
Brian D. Shames ◽  
...  
Keyword(s):  
Temporal Relationship ◽  
Contractile Function ◽  
Myocardial Depression ◽  
Tnf Α ◽  
Myocardial Contractile ◽  
Factor Α ◽  
Relationship Of

Exogenous tumor necrosis factor-α (TNF-α) induces delayed myocardial depression in vivo but promotes rapid myocardial depression in vitro. The temporal relationship between endogenous TNF-α and endotoxemic myocardial depression is unclear, and the role of TNF-α in this myocardial disorder remains controversial. Using a rat model of endotoxemia not complicated by shock, we sought to determine 1) the temporal relationship of changes in circulating and myocardial TNF-α with myocardial depression, 2) the influences of protein synthesis inhibition or immunosuppression on TNF-α production and myocardial depression, and 3) the influence of neutralization of TNF-α on myocardial depression. Rats were treated with lipopolysaccharide (LPS, 0.5 mg/kg ip). Circulating and myocardial TNF-α increased at 1 and 2 h, whereas myocardial contractility was depressed at 4 and 6 h. Pretreatment with cycloheximide or dexamethasone abolished the increase in circulating and myocardial TNF-α and preserved myocardial contractile function. Similarly, treatment with TNF binding protein immediately after LPS prevented myocardial depression. We conclude that endogenous TNF-α mediates delayed myocardial depression in endotoxemic rats and that inhibition of TNF-α production or neutralization of TNF-α preserves myocardial contractile function in endotoxemia.

Nonstressed rat model of acute endotoxemia that unmasks the endotoxin-induced TNF-α response

1999 ◽  
Vol 276 (2) ◽  
pp. H671-H678 ◽  
Author(s):  
David W. A. Beno ◽  
Robert E. Kimura
Keyword(s):  
Rat Model ◽  
Endotoxic Shock ◽  
Stress Hormones ◽  
Tnf Α ◽  
Baseline Concentrations ◽  
Experimental Protocols ◽  
Factor Α ◽  
Necrosis Factor

Previous investigators have demonstrated that the tumor necrosis factor-α (TNF-α) response to endotoxin is inhibited by exogenous corticosterone or catecholamines both in vitro and in vivo, whereas others have reported that surgical and nonsurgical stress increase the endogenous concentrations of these stress-induced hormones. We hypothesized that elevated endogenous stress hormones resultant from experimental protocols attenuated the endotoxin-induced TNF-α response. We used a chronically catheterized rat model to demonstrate that the endotoxin-induced TNF-α response is 10- to 50-fold greater in nonstressed (NS) rats compared with either surgical-stressed (SS, laparotomy) or nonsurgical-stressed (NSS, tail vein injection) models. Compared with the NS group, the SS and NSS groups demonstrated significantly lower mean peak TNF-α responses at 2 mg/kg and 6 μg/kg endotoxin [NS 111.8 ± 6.5 ng/ml and 64.3 ± 5.9 ng/ml, respectively, vs. SS 3.9 ± 1.1 ng/ml ( P < 0.01) and 1.3 ± 0.5 ng/ml ( P < 0.01) or NSS 5.2 ± 3.2 ng/ml ( P < 0.01) at 6 μg/kg]. Similarly, baseline concentrations of corticosterone and catecholamines were significantly lower in the NSS group [84.5 ± 16.5 ng/ml and 199.8 ± 26.2 pg/ml, respectively, vs. SS group 257.2 ± 35.7 ng/ml ( P< 0.01) and 467.5 ± 52.2 pg/ml ( P < 0.01) or NS group 168.6 ± 14.4 ng/ml ( P < 0.01) and 1,109.9 ± 140.7 pg/ml ( P < 0.01)]. These findings suggest that the surgical and nonsurgical stress inherent in experimental protocols increases baseline stress hormones, masking the endotoxin-induced TNF-α response. Subsequent studies of endotoxic shock should control for the effects of protocol-induced stress and should measure and report baseline concentrations of corticosterone and catecholamines.

scholarly journals Short-term alpha- or gamma-delta-enriched tocopherol oil supplementation differentially affects the expression of proinflammatory mediators: selective impacts on characteristics of protein tyrosine nitration in vivo

2013 ◽  
Vol 3 (1) ◽  
pp. 6 ◽  
Author(s):  
Ted H. Elsasser ◽  
Stanislaw Kahl ◽  
Katie M. Lebold ◽  
Maret G. Traber ◽  
Jessica Shaffer ◽  
...  
Keyword(s):  
Plasma Concentrations ◽  
Short Term ◽  
Proinflammatory Response ◽  
E Coli ◽  
Amyloid A ◽  
Proinflammatory Mediators ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

While vitamin E has been used for decades in cattle diets, the principle form used traditionally is the synthetic α-isoform acetate or succinate and largely no data exist on the biological partitioning or functionality of the major naturally occurring γ- and δ-isoforms in cattle. Using tyrosine 3’-nitrated protein (pNT) as a biomarker of nitrosative cell stress, we sought to evaluate the effectiveness of short-term feeding supplementation of high content natural α-tocopherol (<em>α-T</em>, 96% α-isomer) compared to high content γ- and δ-enriched low α-content mixed tocopherol oils (<em>γ-T</em>, ~70% <em>γ-</em>, 20% δ-, &lt;5% α-isoform) to mitigate systemic and hepatic aspects of the proinflammatory response to endotoxin (LPS). Calves fed diets supplemented with <em>α-T</em>, <em>γ-T</em> for five days or no tocopherol supplement (<em>T0E</em>) were challenged with a low-level of LPS (0.25 μg/kg, iv, <em>E. coli </em>055:B5) sufficient to effect a liver nitration response. As fed,<em> α-T</em> or <em>γ-T</em> increased plasma and liver content of the respective tocopherols reflecting their relative abundance in the respective diets. Plasma or tissue mediators and biomarkers of the proinflammatory response [plasma concentrations of tumor necrosis factor-α (TNF-α, P&lt;0.001), nitrate+nitrite (NOx, P&lt;0.01), and serum amyloid A (SAA, P&lt;0.001)], and general liver content of pNT (P&lt;0.005) increased after LPS. LPS-mediated increases in TNF-α were not dif- ferent between diet treatments; both plasma NOx (P&lt;0.05) and generalized liver pNT (P&lt;0.03) responses were attenuated significantly in <em>α-T </em>and <em>γ-T versus T0E calves</em>. Plasma SAA was significantly decreased in γ-T calves at 24 h post-LPS relative to responses in <em>α-T</em> or <em>T0E </em>calves. The nitration of the mitochondrial proteins 24 h post-LPS was not only attenuated in <em>α-T</em> and <em>γ-T vs T0E</em>, but also the mitigating effect of <em>γ-T</em> on these specific nitration events was greater than that of <em>α-T </em>(P&lt;0.01). Results are consistent with the concept that short-term <em>α-T</em> or <em>γ-T</em> supplementation can effectively decrease proinflammatory liver pNT after LPS; some mitochondrial nitration targets may be better protected with prophylactic supplementation with γ-,δ-tocopherol enriched oil.

Differential protective effects of Bcl-xL and Bcl-2 on apoptotic liver injury in transgenic mice

1999 ◽  
Vol 277 (3) ◽  
pp. G702-G708 ◽  
Author(s):  
Alix de la Coste ◽  
Monique Fabre ◽  
Nathalie McDonell ◽  
Arlette Porteu ◽  
Helène Gilgenkrantz ◽  
...  
Keyword(s):  
Liver Injury ◽  
Transgenic Mice ◽  
Fas Ligand ◽  
Dependent Manner ◽  
Protective Effects ◽  
Tnf Α ◽  
Apoptotic Pathways ◽  
Induced Apoptosis ◽  
Factor Α

Fas ligand (CD95L) and tumor necrosis factor-α (TNF-α) are pivotal inducers of hepatocyte apoptosis. Uncontrolled activation of these two systems is involved in several forms of liver injury. Although the broad antiapoptotic action of Bcl-2 and Bcl-xL has been clearly established in various apoptotic pathways, their ability to inhibit the Fas/CD95- and TNF-α-mediated apoptotic signal has remained controversial. We have demonstrated that the expression of BCL-2 in hepatocytes protects them against Fas-induced fulminant hepatitis in transgenic mice. The present study shows that transgenic mice overexpressing[Formula: see text]in hepatocytes are also protected from Fas-induced apoptosis in a dose-dependent manner. Bcl-xL and Bcl-2 were protective without any change in the level of endogenous[Formula: see text]or Bax and inhibited hepatic caspase-3-like activity. In vivo injection of TNF-α caused massive apoptosis and death only when transcription was inhibited. Under these conditions,[Formula: see text]mice were partially protected from liver injury and death but PK-BCL-2 mice were not. A similar differential protective effect of Bcl-xL and Bcl-2 transgenes was observed when Fas/CD95 was activated and transcription blocked. These results suggest that apoptosis triggered by activation of both Fas/CD95 and TNF-α receptors is to some extent counteracted by the transcription-dependent protective effects, which are essential for the antiapoptotic activity of Bcl-2 but not of Bcl-xL. Therefore, Bcl-xL and Bcl-2 appear to have different antiapoptotic effects in the liver whose characterization could facilitate their use to prevent the uncontrolled apoptosis of hepatocytes.

Regulation of granulocyte apoptosis by NF-κB

2004 ◽  
Vol 32 (3) ◽  
pp. 465-467 ◽  
Author(s):  
C. Ward ◽  
A. Walker ◽  
I. Dransfield ◽  
C. Haslett ◽  
A.G. Rossi
Keyword(s):  
Nuclear Factor Κb ◽  
Resolution Of Inflammation ◽  
Tnf Α ◽  
Successful Resolution ◽  
Factor Α ◽  
Apoptotic Effects ◽  
Second Wave ◽  
Crucial Part

Granulocyte apoptosis is a crucial part of the successful resolution of inflammation. In vitro results show that activation of NF-κB (nuclear factor κB) in granulocytes is a survival mechanism. NF-κB inhibitors increase the rate of constitutive apoptosis in neutrophils and eosinophils and cause these cells to respond to the pro-apoptotic effects of TNF-α (tumour necrosis factor-α). Results from both in vivo and in vitro experiments suggest that there are at least two important waves of NF-κB activation in inflammatory loci, which increase the expression of COX-2 (cyclooxygenase-2), itself an NF-κB controlled gene. The first wave causes the production of inflammatory mediators such as PGE2 (prostaglandin E2), allowing the establishment of inflammation. The second wave causes the synthesis of PGD2 and its metabolites that induce granulocyte apoptosis by inhibiting NF-κB activation. These metabolites may therefore be important physiological mediators controlling the resolution of inflammation. Although NF-κB is an important target for anti-inflammatory therapy, the timing of inhibition in vivo may be crucial, to ensure that production of PGD2 and its sequential metabolites can occur.

A novel fluorinated stilbene exerts hepatoprotective properties in CCl4-induced acute liver damage

2011 ◽  
Vol 89 (10) ◽  
pp. 759-766 ◽  
Author(s):  
Horacio Rivera ◽  
Martha S. Morales-Ríos ◽  
Wendy Bautista ◽  
Mineko Shibayama ◽  
Víctor Tsutsumi ◽  
...  
Keyword(s):  
Liver Damage ◽  
Inflammatory Responses ◽  
Acute Liver Damage ◽  
Tnf Α ◽  
Male Wistar Rats ◽  
Anti Inflammatory ◽  
Factor Α ◽  
Glutamyl Transpeptidase

There has been a recently increase in the development of novel stilbene-based compounds with in vitro anti-inflamatory properties. For this study, we synthesized and evaluated the anti-inflammatory properties of 2 fluorinated stilbenes on carbon tetrachloride (CCl4)-induced acute liver damage. To achieve this, CCl4 (4 g·kg–1, per os) was administered to male Wistar rats, followed by either 2-fluoro-4′-methoxystilbene (FME) or 2,3-difluoro-4′-methoxystilbene (DFME) (10 mg·kg–1, per os). We found that although both of the latter compounds prevented cholestatic damage (γ-glutamyl transpeptidase activity), only DFME showed partial but consistent results in the prevention of necrosis, as assessed by both alanine aminotransferase activity and histological analysis. Since inflammatory responses are mediated by cytokines, mainly tumour necrosis factor α (TNF-α), we used the Western blot technique to determine the action of FME and DFME on the expression level of this cytokine. The observed increase in the level of TNF-α caused by CCl4 administration was only prevented by treatment with DFME, in agreement with our biochemical findings. This result was confirmed by measuring interleukin-6 (IL-6) levels, since the expression of this protein depends on the level of TNF-α. In this case, DFME completely blocked the CCl4-induced increase of IL-6. Our results suggest that DFME possesses greater anti-inflammatory properties in vivo than FME. DFME constitutes a possible therapeutic agent for liver disease and could serve as a template for structure optimization.

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