Purification and characterization of cytokine-induced neutrophil chemoattractant produced by epithelioid cell line of normal rat kidney (NRK-52E cell)

Breaking the symmetry of cell contractility drives tubulogenesis via CXCL1 polarization

The intricate interplay between biomechanical and biochemical pathways in modulating morphogenesis is an interesting research topic. How biomechanical force regulates epithelial cell tubulogenesis remains poorly understood. Here, we established a model of tubulogenesis by culturing renal proximal tubular epithelial cells on a collagen gel while manipulating contractile force. Epithelial cells were dynamically self-organized into tubule-like structures by augmentation of cell protrusions and cell-cell association. Reduction and asymmetric distribution of phosphorylated myosin light chain 2, the actomyosin contractility, in cells grown on soft matrix preceded tube connection. Notably, reducing matrix stiffness via sonication of collagen fibrils and inhibiting actomyosin contractility with blebbistatin promoted tubulogenesis, whereas inhibition of cytoskeleton polymerization suppressed it. CXC chemokine ligand 1 (CXCL1) expression was transcriptionally upregulated in cells undergoing tubulogenesis. Additionally, inhibiting actomyosin contractility facilitated CXCL1 polarization and cell protrusions preceding tube formation. Conversely, inhibiting the CXCL1-CXC receptor 1 pathway hindered cell protrusions and tubulogenesis. Mechanical property asymmetry with cell-collagen fibril interaction patterns at cell protrusions and along the tube structure supported the association of anisotropic contraction with tube formation. Furthermore, suppressing the mechanosensing machinery of integrin subunit beta 1 reduced CXCL1 expression, collagen remodeling, and impaired tubulogenesis. In summary, symmetry breaking of cell contractility on a soft collagen gel promotes CXCL1 polarization at cell protrusions which in turn facilitates cell-cell association and thus tubule connection.

Fecal Microbiota Transplantation Modulates Renal Phenotype in the Humanized Mouse Model of IgA Nephropathy

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis. Several observations suggest that gut microbiota could be implicated in IgAN pathophysiology. Aiming at exploring whether microbiota modulation is able to influence disease outcome, we performed fecal microbiota transplantation (FMT) from healthy controls (HC-sbjs), non-progressor (NP-pts) and progressor (P-pts) IgAN patients to antibiotic-treated humanized IgAN mice (α1KI-CD89Tg), by oral gavage. FMT was able to modulate renal phenotype and inflammation. On one hand, the microbiota from P-pts was able to induce an increase of serum BAFF and galactose deficient-IgA1 levels and a decrease of CD89 cell surface expression on blood CD11b⁺ cells which was associated with soluble CD89 and IgA1 mesangial deposits. On the other hand, the microbiota from HC-sbjs was able to induce a reduction of albuminuria immediately after gavage, an increased cell surface expression of CD89 on blood CD11b⁺ cells and a decreased expression of KC chemokine in kidney. Higher serum BAFF levels were found in mice subjected to FMT from IgAN patients. The main bacterial phyla composition and volatile organic compounds profile significantly differed in mouse gut microbiota. Microbiota modulation by FMT influences IgAN phenotype opening new avenues for therapeutic approaches in IgAN.

Sevoflurane attenuates systemic inflammation compared with propofol, but does not modulate neuro-inflammation: A laboratory rat study

BACKGROUND

Septic encephalopathy is believed to be a result of neuro-inflammation possibly triggered by endotoxins, such as lipopolysaccharides (LPS). Modulation of the immune system is a property of volatile anaesthetics.

OBJECTIVE

We aimed to investigate the systemic and cerebral inflammatory response in a LPS-induced sepsis model in rats. We compared two different sedation strategies, intravenous propofol and the volatile anaesthetic sevoflurane, with the hypothesis that the latter may attenuate neuro-inflammatory processes.

DESIGN

Laboratory rat study.

SETTING

Basic research laboratories at the University Hospital Zurich and University Zurich Irchel between August 2014 and June 2016.

PATIENTS

A total of 32 adult male Wistar rats.

INTERVENTIONS

After tracheotomy and mechanical ventilation, the anaesthetised rats were monitored before sepsis was induced by using intravenous LPS or phosphate-buffered saline as control. Rats were sedated with propofol (10 mg kg h) or sevoflurane (2 vol%) continuously for 12 h.

MAIN OUTCOME MEASURES

Systemic inflammatory markers such as cytokine-induced neutrophil chemo-attractant protein 1, monocyte chemo-tactic protein-1 and IL-6 were determined. The same cytokines were measured in brain tissue. Cellular response in the brain was assessed by defining neutrophil accumulation with myeloperoxidase and also activation of microglia with ionised calcium-binding adaptor molecule-1 and astrocytes with glial fibrillary acidic protein. Finally, brain injury was determined.

RESULTS

Animals were haemodynamically stable in both sedation groups treated with LPS. Blood cytokine peak values were lower in the sevoflurane-LPS compared with propofol-LPS animals. In brain tissue of LPS animals, chemoattractant protein-1 was the only significantly increased cytokine (P = 0.003), however with no significance between propofol and sevoflurane. After LPS challenge, cerebral accumulation of neutrophils was observed. Microglia activation was pronounced in the hippocampus of animals treated with LPS (P = 0.006). LPS induced prominent astrogliosis (P < 0.001). There was no significant difference in microglia or astrocyte activation or apoptosis in the brain between sevoflurane and propofol.

CONCLUSION

We have shown that systemic attenuation of inflammation by the volatile anaesthetic sevoflurane did not translate into attenuated neuro-inflammation in this LPS-induced inflammation model.

TRIAL REGISTRATION

Animal approval No. 134/2014, Veterinäramt Zürich.

Identification of Novel Inflammatory Cytokines and Contribution of Keratinocyte-Derived Chemokine to Inflammation in Response to Vibrio vulnificus Infection in Mice

Currently, only tumor necrosis factor alpha (TNF-α) and interleukin family cytokines have been found to be elicited in Vibrio vulnificus (V. vulnificus)-infected animal models and humans. However, multiple other cytokines are also involved in the immune and inflammatory responses to foreign microorganism infection. Antibody array technology, unlike traditional enzyme-linked immunosorbent assay (ELISA), is able to detect multiple cytokines at one time. Therefore, in this study, we examined the proinflammatory cytokine profile in the serum and liver homogenate samples of bacterial-infected mice using antibody array technology. We identified nine novel cytokines in response to V. vulnificus infection in mice. We found that keratinocyte-derived chemokine (KC) was the most elevated cytokine and demonstrated that KC played a very important role in the V. vulnificus infection-elicited inflammatory response in mice, as evidenced by the fact that the blocking of KC by anti-KC antibody reduced hepatic injury in vivo and that KC induced by V. vulnificus infection in AML-12 cells chemoattracted neutrophils. Our findings implicate that KC may serve as a novel diagnostic biomarker and a possible therapeutic target for V. vulnificus infection.

Altered expression of Butyrophilin (BTN) and BTN-like (BTNL) genes in intestinal inflammation and colon cancer

Several Butyrophilin (BTN) and Btn‐like (BTNL) molecules control T lymphocyte responses, and are genetically associated with inflammatory disorders and cancer. In this study, we present a comprehensive expression analysis of human and murine BTN and BTNL genes in conditions associated with intestinal inflammation and cancer. Using real‐time PCR, expression of human BTN and BTNL genes was analyzed in samples from patients with ulcerative colitis, irritable bowel syndrome, and colon tumors. Expression of murine Btn and Btnl genes was examined in mouse models of spontaneous colitis (Muc2^−/−) and intestinal tumorigenesis (Apc^Min/+). Our analysis indicates a strong association of several of the human genes with ulcerative colitis and colon cancer; while especially BTN1A1, BTN2A2, BTN3A3, and BTNL8 were significantly altered in inflammation, colonic tumors exhibited significantly decreased levels of BTNL2, BTNL3, BTNL8, and BTNL9 as compared to unaffected tissue. Colonic inflammation in Muc2^−/− mice significantly down‐regulated the expression of particularly Btnl1, Btnl4, and Btnl6 mRNA, and intestinal polyps derived from Apc^Min/+ mice displayed altered levels of Btn1a1, Btn2a2, and Btnl1 transcripts. Thus, our data present an association of BTN and BTNL genes with intestinal inflammation and cancer and represent a valuable resource for further studies of this gene family.

Nanotoxicity of poly(n-butylcyano-acrylate) nanoparticles at the blood-brain barrier, in human whole blood and in vivo

Therapy of diseases of the central nervous system is a major challenge since drugs have to overcome the blood-brain barrier (BBB). A powerful strategy to enhance cerebral drug concentration is administration of drug-loaded poly(n-butylcyano-acrylate) (PBCA) nanoparticles coated with polysorbate 80 (PS80). This study evaluates the toxicity of PBCA-nanoparticles at the BBB, representing the target organ, the inflammatory response in human whole blood, as the site of administration and in a rat model in vivo. PBCA-nanoparticles were prepared by a mini-emulsion method and characterized concerning size, surface charge, shape and PS80-adsorption. The influence on metabolic activity, cell viability and integrity of the BBB was analyzed in an in vitro model of the BBB. In ex vivo experiments in human whole blood the release of 12 inflammatory cytokines was investigated. In addition, the inflammatory response was studied in vivo in rats and complemented with the analysis of different organ toxicity parameters. PBCA-nanoparticles showed time- and concentration-dependent effects on metabolic activity, cell viability and BBB integrity. No cell death or loss of metabolic activity was observed for nanoparticle-concentrations ≤500μg/ml up to 3h of treatment. Within 12 tested inflammatory cytokines, only interleukin-8 displayed a significant release after nanoparticle exposure in human blood. No severe inflammatory processes or organ damages were identified in rats in vivo. Thus, PBCA-nanoparticles are a promising drug delivery system to overcome the BBB since they showed hardly any cytotoxic or inflammatory effect at therapeutic concentrations and incubation times.

Butyrophilin-like 1 encodes an enterocyte protein that selectively regulates functional interactions with T lymphocytes

Although local regulation of T-cell responses by epithelial cells is increasingly viewed as important, few molecules mediating such regulation have been identified. Skint1, a recently identified member of the Ig-supergene family expressed by thymic epithelial cells and keratinocytes, specifies the murine epidermal intraepithelial lymphocyte (IEL) repertoire. Investigating whether Skint1-related molecules might regulate IEL in other compartments, this study focuses on buytrophilin-like 1 (Btnl1), which is conspicuously similar to Skint1 and primarily restricted to small intestinal epithelium. Btnl1 protein is mostly cytoplasmic, but surface expression can be induced, and in vivo Btnl1 can be detected adjacent to the IEL. In a newly developed culture system, enforced epithelial cell expression of Btnl1 attenuated the cells' response to activated IEL, as evidenced by suppression of IL-6 and other inflammatory mediators. These findings offer a unique perspective on emerging genetic data that Btnl genes may comprise novel and important local regulators of gut inflammation.

Effect of olprinone, a phosphodiesterase III inhibitor, on hepatic ischemia-reperfusion injury in rats

I/R injury is the main cause for hepatic dysfunction and failure after liver transplantation and liver resection. Therefore, reduction of I/R injury is the most important goal to improve the outcome of these procedures. Olprinone is a newly developed selective phosphodiesterase III inhibitor, which has been reported to ameliorate renal I/R injury in rats. However, no clear evidence for the actions of olprinone on inflammatory response after hepatic I/R injury has been disclosed thus far. Our study was designed to evaluate the action of olprinone on the hepatic I/R injury in rats. Olprinone increased the cyclic adenosine monophosphate level in injured liver tissue and ameliorated the liver injury after hepatic I/R. Moreover, olprinone suppressed the activation of p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, and nuclear factor-kappaB, cytokine production (TNF-alpha, IL-6, and cytokine-induced neutrophil chemoattractant factor 1), and intercellular adhesion molecule 1 expression in liver after hepatic I/R. These observations suggest that olprinone protects liver against I/R injury via the elevation of cyclic adenosine monophosphate level and suppression of intercellular adhesion molecule 1 expression and cytokine production (TNF-alpha, IL-6, and cytokine-induced neutrophil chemoattractant factor 1), possibly by interfering with the signaling pathways of p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, and nuclear factor-kappaB in rats.

Protective effects of immunophilin ligands on testicular torsion/detorsion damage in rats

OBJECTIVES

The purpose was to investigate the role of immunophilin ligands in ischemia/reperfusion (I/R)-induced germ cell apoptosis in the rat.

MATERIALS AND METHODS

Sprague-Dawley rats were divided into five groups with ten animals in each. In animals undergoing torsion/detorsion, right testes were rotated 720 degrees for 1 h. A baseline group was for basal normal values. The sham-operated group served as a control group. The TD group underwent torsion/detorsion surgery alone; the cyclosporine-A group (TD-CsA) received intravenous cyclosporine injection (5 mg/kg) at the time of detorsion, and the FK-506 group (TD-FK) received intravenous FK-506 (3.5 mg/kg) at the time of detorsion. For measurement of lipid peroxidation and antioxidant enzyme activities, the right testes of five animals in each group were excised after 4-h reperfusion. Germ cell apoptosis indices were determined 24 h following detorsion in the right testes of the remaining five animals in each group.

RESULTS

Malondialdehyde (MDA) levels in the TD group were significantly higher compared to control and baseline groups. Moreover, testicular MDA values in TD-CsA and TD-FK groups were significantly lower than in TD. There were also significant decreases in catalase and superxide dismutase activities in the TD group compared to control and baseline groups. These values in TD-CsA and TD-FK groups were significantly higher than in TD. The mean germ cell apoptosis scores were significantly higher in TD animals compared to control and baseline groups; however, CsA and FK-506 treatment significantly reduced the apoptosis compared with the TD group.

CONCLUSION

We have shown that administration of immunophilin ligands in testicular torsion decreases ischemia/reperfusion (I/R) cellular damage. The results of biochemical studies suggest that reduction of oxidative stress along with attenuated neutrophil accumulation by immunophilin ligands may have a major role in their cytoprotective effects.

Upregulation and function of GADD45gamma in unilateral ureteral obstruction

We performed differential display analysis to determine transcriptional activity in the rat kidney, following unilateral ureteral obstruction and found a 12-fold increase in the expression of Growth Arrest and DNA Damage-45gamma (GADD45gamma), a stress-responsive molecule that interacts with cell-cycle proteins. GADD45gamma was strongly expressed in as little as 6 h following ureteric obstruction in the renal tubules, and was also found in kidney tissue of patients with chronic glomerulonephritis. Adenovirus-mediated expression of GADD45gamma in cultured renal tubular cells activated p38 along with a significant upregulation of C-C and C-X3-C chemokine ligands and fibrosis-related factors such as several matrix metalloproteinases, transforming growth factor-beta1, decorin, and bone morphogenetic protein 2. Silencing of GADD45gamma expression significantly blunted the upregulation of these inflammatory and fibrogenic mediators and monocyte infiltration in the ureteral obstructed rat kidney. Our study shows that GADD45gamma is quickly upregulated in the kidney with an obstructed ureter, enhancing the production of factors regulating the pathogenesis of kidney disease.

The role of estrogen receptor subtypes on hepatic neutrophil accumulation following trauma-hemorrhage: direct modulation of CINC-1 production by Kupffer cells

Although 17beta-estradiol (E2) administration following trauma-hemorrhage (T-H) reduces liver injury by decreasing neutrophil accumulation via estrogen receptor (ER)-alpha, it remains unclear whether cytokine-induced neutrophil chemoattractant (CINC)-1 production by Kupffer cells (KC) is directly modulated by ER-alpha under such condition. Male rats underwent laparotomy and hemorrhagic shock (40 mmHg for 90 min), followed by resuscitation with four times the shed blood volume in the form of Ringer's lactate. ER-alpha agonist propyl pyrazole triol (PPT; 5 microg/kg), ER-beta agonist diarylpropionitrile (DPN; 5 microg/kg), E2 (50 microg/kg), or vehicle (10% DMSO) was administered subcutaneously during resuscitation; rats were sacrificed 24h thereafter. KC were isolated and cultured with ER agonists to examine if they directly affect CINC-1 production. T-H increased plasma alanine aminotransferase (ALT; hepatic injury) and hepatic myeloperoxidase (MPO) activity. E2, PPT and DPN administration reduced increased ALT; however, PPT was more effective than DPN. PPT and E2, but not DPN significantly attenuated increased hepatic MPO activity and CINC-1 levels. PPT addition in vitro (10(-7) and 10(-6)M) significantly reduced KC CINC-1 production. In summary, the salutary effects of E2 against hepatic injury are mediated predominantly via ER-alpha which directly modulates KC CINC-1 production and hepatic neutrophil accumulation following T-H.

Enhanced heat shock protein 70 expression alters proteasomal degradation of IkappaB kinase in experimental acute respiratory distress syndrome

OBJECTIVES

Acute respiratory distress syndrome is a common and highly lethal inflammatory lung syndrome. We previously have shown that an adenoviral vector expressing the heat shock protein (Hsp)70 (AdHSP) protects against experimental sepsis-induced acute respiratory distress syndrome in part by limiting neutrophil accumulation in the lung. Neutrophil accumulation and activation is modulated, in part, by the nuclear factor-kappaB (NF-kappaB) signal transduction pathway. NF-kappaB activation requires dissociation/degradation of a bound inhibitor, IkappaBalpha. IkappaBalpha degradation requires phosphorylation by IkappaB kinase, ubiquitination by the SCFbeta-TrCP (Skp1/Cullin1/Fbox beta-transducing repeat-containing protein) ubiquitin ligase, and degradation by the 26S proteasome. We tested the hypothesis that Hsp70 attenuates NF-kappaB activation at multiple points in the IkappaBalpha degradative pathway.

DESIGN

Laboratory investigation.

SETTING

University medical center research laboratory.

SUBJECTS

Adolescent (200 g) Sprague-Dawley rats and murine lung epithelial-12 cells in culture.

INTERVENTIONS

Lung injury was induced in rats via cecal ligation and double puncture. Thereafter, animals were treated with intratracheal injection of 1) phosphate buffer saline, 2) AdHSP, or 3) an adenovirus expressing green fluorescent protein. Murine lung epithelial-12 cells were stimulated with tumor necrosis factor-alpha and transfected. NF-kappaB was examined using molecular biological tools.

MEASUREMENTS AND MAIN RESULTS

Intratracheal administration of AdHSP to rats with cecal ligation and double puncture limited nuclear translocation of NF-kappaB and attenuated phosphorylation of IkappaBalpha. AdHSP treatment reduced, but did not eliminate, phosphorylation of the beta-subunit of IkappaB kinase. In vitro kinase activity assays and gel filtration chromatography revealed that treatment of sepsis-induced lung injury with AdHSP induced fragmentation of the IkappaB kinase signalosome. This stabilized intermediary complexes containing IkappaB kinase components, IkappaBalpha, and NF-kappaB. Cellular studies indicate that although ubiquitination of IkappaBalpha was maintained, proteasomal degradation was impaired by an indirect mechanism.

CONCLUSIONS

Treatment of sepsis-induced lung injury with AdHSP limits NF-kappaB activation. This results from stabilization of intermediary NF-kappaB/IkappaBalpha/IkappaB kinase complexes in a way that impairs proteasomal degradation of IkappaBalpha. This novel mechanism by which Hsp70 attenuates an intracellular process may be of therapeutic value.

Contribution of TNFα, IL-1β and CINC-1 for articular incapacitation, edema and cell migration in a model of LPS-induced reactive arthritis

The protective effect of anti-CINC-1, -TNFalpha and -IL-1beta antisera on articular inflammatory incapacitation, articular diameter and synovial fluid cell content, which are correlated to nociception, edema and cell migration, respectively, were evaluated in a rat model of LPS-induced reactive arthritis. In this model, Escherichia coli lipopolysaccharide (LPS; 30 ng) was injected in a knee-joint previously primed with carrageenan (300 microg). Articular incapacitation was evaluated hourly by the automated registering of the knee-joint function during animal walking, and the knee-joint edema was evaluated by measuring the articular diameter increase. After 6 h, the animals were euthanized for collecting synovial fluid for the evaluation of cell migration. LPS produced dose-dependent incapacitation and edema. Anti-TNFalpha, -IL-1beta, and -CINC-1 antisera (20 and 40 microl) were used as pretreatment into knee-joint before LPS injection. At higher dose, Anti-TNFalpha and anti-CINC-1 were able to inhibit incapacitation, articular edema and mononuclear (MON) migration. Anti-IL1beta did not affect incapacitation at any dose, although inhibited edema and cell migration. Surprisingly, the higher dose of anti-IL1beta antisera did not inhibit cell migration, although inhibited articular edema. These findings corroborate the role TNFalpha has in different forms of arthritis, but points out the idea that CINC-1 (the homologue for human IL-8) may constitute a promising target for reactive arthritis management. Indeed, the potent antiedematogenic effect, and principally the anti-migration effect of anti-CINC-1, raises the possibility of a better control of disease progression than with anti-IL-1beta therapies.

Induction of IL-8 expression by human herpesvirus 8 encoded vFLIP K13 via NF-kappaB activation

Human herpesvirus 8 (HHV-8) encodes a viral FLICE inhibitory protein (vFLIP), called K13, with homology to the prodomain of caspase 8. K13 has been postulated to protect virally infected cells against death receptor-induced apoptosis. We report that K13 leads to constitutive upregulation of IL-8 secretion by transcriptional upregulation of its promoter. K13-induced IL-8 promoter activation is dependent on an intact NF-kappaB-binding site and is associated with increased binding of classical NF-kappaB pathway subunits p65, c-Rel and p50, respectively. IL-8 production is defective in K13 mutants defective in classical NF-kappaB activation and is blocked by genetic and pharmacological inhibitors of this pathway. In contrast, K13 failed to activate the JNK/AP-1 pathway and deletion of AP-1-binding site in the IL-8 promoter or use of a specific JNK inhibitor had only a partial effect on K13-induced IL-8 promoter activation. Collectively, above results demonstrate that K13 is a major mediator of IL-8 production and therapeutic agents targeting K13-induced NF-kappaB pathway may have a role in the treatment of conditions in which HHV-8-induced IL-8 production plays a pathogenic role.

A free radical scavenger but not FGF-2-mediated angiogenic therapy rescues myonephropathic metabolic syndrome in severe hindlimb ischemia

The therapeutic use of angiogenic factors shows promise in the treatment of critical limb ischemia; however, its potential for myonephropathic metabolic syndrome (MNMS), a fatal complication caused by arterial reconstruction, has not been elucidated. The objective of this study was to evaluate the effectiveness of recombinant Sendai virus-mediated gene transfer of fibroblast growth factor-2 (FGF-2) directly compared with that of a radical scavenger, MCI-186, in a rat model of MNMS. MNMS was surgically induced by aortic occlusion below renal arteries for 4 h, followed by 6 h of reperfusion. Administration of MCI-186 (twice; iv 5 min before induced ischemia and ip 5 min before reperfusion; 10 mg/kg, respectively), but not FGF-2 gene transfer (once, 48 h before induced ischemia), dramatically prevented the increase of serum biochemical markers as well as the edema of the gastrocnemius muscle. The effect of MCI-186 was accompanied by the marked suppression of the neutrophilic infiltration into the local (muscle) and remote (lung) organs. Although serum and muscular levels of a neutrophil-chemoattractant (growth-related oncogene/cytokine-induced neutrophil chemoattractant-1) were not affected by any treatment, the serum level of soluble intercellular adhesion molecule-1 was decreased by treatment with MCI-186 but not by treatment with FGF-2. These results suggest the distinct mechanism of MNMS from critical limb ischemia without reperfusion. Therefore, radical scavenging should be paid more attention than therapeutic angiogenesis when arterial circulation is reconstructed.

Increased circulating concentrations of growth-related oncogene (GRO)-alpha in patients with inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory state associated with increased risk of intestinal cancers. The aim of this study is to examine serum concentrations of growth-related oncogene (GRO)-alpha, a cytokine with inflammatory and growth-regulatory properties, in patients with IBD. We measured serum concentrations of GRO-alpha in 60 patients with ulcerative colitis, 42 patients with Crohn's disease, 16 patients with other colitides, 12 patients with colorectal cancer, and 40 normal subjects using an enzyme-linked immunosorbent assay. We then analyzed how the cytokine was related to clinical and laboratory variables. Serum GRO-alpha concentrations in patients with active IBD were significantly higher than those in patients with quiescent disease, which in turn were higher than those in normal controls. Concentrations in patients with active ulcerative colitis were higher than in patients with active Crohn's disease. Analysis of paired serum samples showed a decrease in GRO-alpha after initiation of therapy. Furthermore, serum GRO-alpha correlated well with laboratory markers of IBD activity. We conclude that GRO-alpha may have an important role in development of IBD, and might itself be used as a marker of activity. Manipulation of GRO-alpha function might prove therapeutically useful.

Central endothelin ETBreceptors mediate IL-1-dependent fever induced by preformed pyrogenic factor and corticotropin-releasing factor in the rat

Blockade of central endothelin ETBreceptors inhibits fever induced by LPS in conscious rats. The contribution of ETBreceptor-mediated mechanisms to fever triggered by intracerebroventricular IL-6, PGE2, PGF2α, corticotropin-releasing factor (CRF), and preformed pyrogenic factor derived from LPS-stimulated macrophages (PFPF) was examined. The influence of natural IL-1 receptor antagonist or soluble TNF receptor I on endothelin (ET)-1-induced fever was also assessed. The selective ETBreceptor antagonist BQ-788 (3 pmol icv) abolished fever induced by intracerebroventricular ET-1 (1 pmol) or PFPF (200 ng) and reduced that caused by ICV CRF (1 nmol) but not by IL-6 (14.6 pmol), PGE2(1.4 nmol), or PGF2α(2 nmol). CRF-induced fever was also attenuated by bosentan (dual ETA/ETBreceptor antagonist; 10 mg/kg iv) but unaffected by BQ-123 (selective ETAreceptor antagonist; 3 pmol icv). α-Helical CRF9–41(dual CRF1/CRF2receptor antagonist; 6.5 nmol icv) attenuated fever induced by CRF but not by ET-1. Human IL-1 receptor antagonist (9.1 pmol) markedly reduced fever to IL-1β (180 fmol) or ET-1 and attenuated that caused by PFPF or CRF. Murine soluble TNF receptor I (23.8 pmol) reduced fever to TNF-α (14.7 pmol) but not to ET-1. The results of the present study suggest that PFPF and CRF recruit the brain ET system to cause ETBreceptor-mediated IL-1-dependent fever.

Inhibition of endotoxin- and antigen-induced airway inflammation by fudosteine, a mucoactive agent

We evaluated the effect of a mucoactive agent (-)-(R)-2-amino-3-(3-hydroxypropylthio) propionic acid (fudosteine), on airway inflammation using endotoxin- and antigen-induced models. Time courses of growth related oncogene/cytokine-induced neutrophil chemoattractant-1 (GRO/CINC-1) production, neutrophil migration and goblet cell hyperplasia were examined in endotoxin-induced rat airway inflammation. GRO/CINC-1 in bronchoalveolar lavage fluid (BALF) increased in response to intratracheal instillation of endotoxin and peaked within 4 h. Neutrophils in BALF and goblet cells on trachea peaked 24 and 96 h after endotoxin instillation, respectively. Fudosteine significantly inhibited increases in GRO/CINC-1 at 10-100 mg/kg, and neutrophils and goblet cells at 30 and 100 mg/kg. These results suggest that inflammatory events including neutrophil chemoattractant production and neutrophil migration play important roles for goblet cell hyperplasia in endotoxin-induced airway inflammation, and fudosteine inhibits goblet cell hyperplasia by inhibiting GRO/CINC-1 production and/or neutrophil migration. Furthermore, fudosteine (100 mg/kg) inhibited ovalbumin-induced eosinophil infiltration into BALF, suggesting it attenuates asthmatic inflammation.

The mechanism of cleavage of EGFR ligands induced by inflammatory cytokines in gastric cancer cells

BACKGROUND & AIMS

The epidermal growth factor (EGF) receptor (EGFR) can be transactivated by many factors including G-protein-coupled receptor agonists and cytokines. Although this EGFR transactivation reportedly requires a disintegrin and metalloproteinase (ADAM) that sheds the ectodomain of EGFR ligands, the detailed mechanisms are still unknown. This study evaluated the mechanism of interleukin (IL)-8- and IL-1beta-dependent shedding of the EGFR ligand in KATO III cells.

METHODS

We established transfectants stably expressing alkaline phosphatase-tagged heparin-binding EGF-like growth factor (HB-EGF), transforming growth factor alpha, or amphiregulin precursors, and depleted ADAM proteins, using short interfering RNA against ADAM10, 12, or 17. We assessed shedding of EGFR ligands by measuring AP activities in the conditioned media after IL-1beta or IL-8 stimulation. EGFR activation was examined by immunoprecipitation and Western blotting using antiphosphotyrosine antibody. KB-R7785 and anti-IL-8 neutralizing antibody were used to inhibit activities of ADAMs and IL-8 action, respectively.

RESULTS

IL-8 dose dependently released the EGFR ligands and transiently phosphorylated EGFR, with a peak at 15 minutes. KB-R7785 completely blocked IL-8-induced shedding and EGFR transactivation. Depletion of ADAM10 also dramatically reduced IL-8-induced shedding and EGFR transactivation, but depletion of ADAM12 and 17 did not. IL-1beta dose dependently enhanced shedding of HB-EGF, which was not blocked by KB-R7785 in the early phase. In the late phase, however, the EGFR transactivation was blocked by KB-R7785 and abrogated by anti-IL-8 neutralizing antibody.

CONCLUSIONS

IL-8 induces shedding of EGFR ligands because of an ADAM10-dependent pathway in gastric cancer cells, whereas IL-1beta acts principally by an ADAM-independent pathway. IL-1beta-dependent prolonged EGFR transactivation involves multiple pathways, including an IL-8-dependent pathway.

The chemokine KC regulates HGF-stimulated epithelial cell morphogenesis

Hepatocyte growth factor (HGF) induces migration, proliferation, and branching in renal epithelial cells from the inner medullary collecting duct (mIMCD-3 cells). Microarray analysis after HGF stimulation of these cells revealed upregulation of the chemokine KC. We found that both the message and protein levels of KC are increased after HGF treatment and that mIMCD-3 cells express the KC receptor CXCR2. Treatment with KC results in stimulation of mIMCD-3 cell proliferation but has no effect on basal rates of cell migration or branching morphogenesis. In contrast to its known stimulatory effect on neutrophil migration, KC markedly inhibits HGF-mediated cell migration and branching morphogenesis, resulting in shorter tubules with fewer branch points. Examination of the mechanism of this effect reveals that KC does not alter phosphorylation of the c-met receptor or the initial activation of the MAPK or phosphoinositide 3-kinase (PI 3-K) signaling pathways. However, sustained activation of the PI 3-K pathway by HGF was inhibited by treatment with KC, and mimicking this effect by treatment with LY-294002 2 h after HGF stimulation reproduced the inhibition of HGF-stimulated branching morphogenesis. These data demonstrate that HGF-mediated KC production can act in an autocrine fashion to downregulate excessive branching and migration of renal epithelial cells in response to HGF, while still supporting cell proliferation. These characteristics may play a role in modulating the response to HGF during developmental tubule formation and/or during the repair of the tubular architecture following injury.

Tumor necrosis factor-alpha-induced cytokine-induced neutrophil chemoattractant-1 (CINC-1) production by rat gastric epithelial cells: role of reactive oxygen species and nuclear factor-kappaB

Rat cytokine-induced neutrophil chemoattractant-1 (CINC-1), a counterpart of the human growth-regulated oncogene product (GRO), has been suggested to participate in neutrophil recruitment in an experimental model of gastritis in rat. However, the mechanism(s) involved in regulation of CINC-1 production by the gastric mucosa remains unclear. The aim of this study was to investigate the mechanism(s) of CINC-1 production by rat gastric mucosa in vitro. All experiments were performed using rat normal gastric mucosal cell line (RGM-1). RGM-1s were stimulated with tumor necrosis factor (TNF)-alpha, and CINC-1 mRNA levels (reverse transcription-polymerase chain reaction) and protein secretion (enzyme-linked immunosorbent assay) were assessed. The production of reactive oxygen species (ROS) and nuclear factor (NF)-kappaB activation (translocation to the nuclei) in response to TNF-alpha stimulation was evaluated using fluorescence microscopy in the presence or absence of the inhibitors of mitochondrial electron flow and NF-kappaB activation. Stimulation of RGM-1 cells with TNF-alpha resulted in an increase in intracellular oxidative stress, NF-kappaB translocation to the nuclei, and up-regulation of CINC-1 mRNA and protein, which was prevented by interfering with mitochondria-dependent ROS production and NF-kappaB activation. Taken together, these findings indicate that CINC-1, a counterpart of the human GRO, production by rat gastric epithelial cells in response to TNF-alpha stimulation is an oxidant stress-mediated and NF-kappaB-dependent event.

Therapy of AIDS-associated Kaposi's sarcoma: targeting pathogenetic mechanisms

Only a small number of the many agents with the potential to inhibit factors known to stimulate KS growth have been tested clinically, and many were investigated at a time when treatment options for HIV infection were relatively ineffective. The failure of some of these agents to induce KS regression may not signify failure to achieve a relevant biologic effect in all cases, but may simply mean that in a neoplasm that expresses a broad array of growth factors, inhibition of a single factor may be insufficient to achieve tumor regression. Moreover, agents that inhibit angiogenesis may be expected to stabilize tumors rather then eradicate them, but tumor stabilization is a difficult endpoint to quantify. In fact, given the redundancy of growth factors believed to be involved in KS development, it is perhaps remarkable that members of several classes of agents (eg, a synthetic retinoid, an MMPI, thalidomide, IL-12) have induced KS regression in a substantial minority of patients. It is likely, however, that drug combinations that target several pathogenetic mechanisms will be more effective than will single drugs in suppressing KS growth. A particular need. especially in the early evaluation of therapies aimed at specific pathogenic targets, is the development of assays to measure specific biologic effects (eg, changes in the activity of signal transduction pathways within tumor biopsy specimens) related to the agent's putative mechanism of action. Greater availability and clinical application of these types of markers of biologic efficacy may speed the identification of potentially active agents that could then be "fast tracked" into larger efficacy trials and combination studies.

Heat-shock preconditioning protects fatty livers in genetically obese Zucker rats from microvascular perfusion failure after ischemia reperfusion

Reduced tolerance of steatotic livers to ischemic injury is considered to correlate with impaired microcirculation. The aim of this study was to investigate the impact of heat-shock preconditioning (HSPC) on microcirculatory failure after ischemia/reperfusion (I/R) in steatotic livers by means of intra-vital fluorescence microscopy. Obese Zucker rats were used. In the HS group, rats underwent whole-body hyperthermia followed by 60-min partial liver ischemia. In group IR, rats were exposed only to ischemia. Microcirculation parameters (sinusoidal perfusion rate, sinusoidal diameter, leukocyte-endothelial interaction) were significantly better preserved in the HS group than in the IR group. Liver enzymes, oxygenated glutathione/reduced glutathione (GSSG/GSH) ratio, and electron microscopy showed less damage in the HS group. A marked expression of heat shock protein 72 (HSP72) and heme oxygenase (HO-1) was found only in the livers of group HS. HSPC mitigated the I/R injury of steatotic livers by preventing post-ischemic failure of microcirculation. This beneficial effect was found to be associated with the induction of HSP72 and HO-1.

Storage solution containing fructose-1,6-bisphosphate inhibits the excess activation of Kupffer cells in cold liver preservation

BACKGROUND

In liver transplantation, the activation of Kupffer cells at the time of cold preservation and reperfusion is considered to play an important role. In the present study, the usefulness of cold storage solution containing fructose-1,6-bisphosphate (FBP) was compared with University of Wisconsin (UW) solution in the function of Kupffer cells.

METHODS

Kupffer cells were separated from rat liver stored at 4 degrees C in each storage solution. Four kinds of storage solutions were used: UW, simplified UW without FBP (0-FBP), and solutions with 10 or 20 mM FBP (10-FBP, 20-FBP). Lipopolysaccharide (LPS) labeled by fluorescein was loaded after 12 or 24 hr of cold preservation in each solution. The rates of cells uptaking LPS as phagocytic ability were measured using flow cytometry. Tumor necrosis factor-alpha, cytokine-induced neutrophil chemoattractant, and nitric oxide (NO) were measured in the supernatant.

RESULTS

Tumor necrosis factor-alpha values in the 20-FBP group were significantly lower than those in the UW group. Cytokine-induced neutrophil chemoattractant values at 60 min after loading LPS were significantly lower in the 20-FBP group than in the UW group. NO values at 24 hr after loading LPS were significantly lower in the 20-FBP group compared with the UW group. The 20-FBP group was highest in the rates of cells uptaking LPS after 24-hr cold preservation.

CONCLUSIONS

The storage solution containing FBP controlled the secretion of cytokines and NO from Kupffer cells and maintained phagocytic ability. This solution was considered to be more useful than UW solution for Kupffer cell protection.

Effect of cold-ischemia time on C-X-C chemokine expression and neutrophil accumulation in the graft liver after orthotopic liver transplantation in rats

BACKGROUND

The precise mechanisms leading to polymorphonuclear neutrophil (PMN) recruitment and activation in the extended cold-preserved liver after transplantation are not yet fully understood.

METHODS

We histologically evaluated the number of accumulated PMNs in graft livers, with varying time periods of cold ischemia (1, 6, and 24 hr in University of Wisconsin solution at 4 degrees C), after liver transplantation in rats. Intragraft expression of macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (CINC) mRNA, as well as immunohistochemical expression of MIP-2 and CINC in the graft liver, were investigated after reperfusion. The levels of MIP-2 and CINC in the hepatic vein, and tumor necrosis factor (TNF)-alpha, which stimulates these chemokine production, were also monitored.

RESULTS

The number of accumulated PMNs in sinusoids significantly increased in the 24-hr cold-ischemia group within 3 hr after reperfusion, compared with the 1-hr and 6-hr groups. Serum MIP-2 levels in the 24-hr group significantly increased at 3, 6, and 12 hr after reperfusion, compared with the other groups. Intragraft MIP-2 mRNA was also up-regulated to a greater extent in the 24-hr group. Similarly, serum CINC levels in the 24-hr group significantly increased at 3 hr, compared with the 1-hr group. CINC mRNA also increased as cold-ischemia time was prolonged. Immunohistochemical staining revealed that hepatocytes were the main source of both MIP-2 and CINC protein. In addition, TNF-alpha in the hepatic vein was detected only in the 24-hr group after reperfusion.

CONCLUSION

Extended cold preservation of the graft liver might up-regulate MIP-2 and CINC expression of hepatocytes, most probably through elevated TNF-alpha, and might contribute to PMN recruitment and activation after reperfusion.

Compartmentalization of macrophage inflammatory protein-2, but not cytokine-induced neutrophil chemoattractant, in rats challenged with intratracheal endotoxin

An important feature of the pulmonary inflammatory response is that the production of certain cytokines and chemokines is largely confined to the lung. This study investigated the local and systemic responses of macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (CINC) in rats administered with either intratracheal or intravenous lipopolysaccharide (LPS). Intratracheal LPS induced a significant increase in MIP-2 in bronchoalveolar lavage (BAL) fluid with no detectable MIP-2 in the plasma. In contrast, CINC was significantly increased in both BAL fluid and the plasma after intratracheal LPS challenge. Cell-associated MIP-2 was increased in the pulmonary-recruited neutrophils (PMNs) but not in the circulating PMNs in rats given intratracheal LPS. Cell-associated CINC was increased in both the recruited and circulating PMNs in these animals. Intravenous LPS caused a marked increase in plasma MIP-2 and CINC, whereas only a small elevation of both MIP-2 and CINC concentrations in BAL fluid was observed. The lack of CINC compartmentalization compared to MIP-2 implies that these C-X-C chemokines are regulated differentially and may have different effects upon polymorphonuclear leukocyte (PMN) recruitment into the alveolar space in response to intrapulmonary LPS or bacterial challenge.

Fatty acids enhance GRO/CINC-1 and interleukin-6 production in rat intestinal epithelial cells

Intestinal mucosal immunity is modulated by cytokine release from intestinal cells, but little is known about the relation between nutrient absorption and cytokine release. In this study, we examined how exposure to fatty acids affects the production of growth-regulated oncogene/cytokine-induced neutrophil chemoattractant-1 (GRO/CINC-1) and interleukin (IL)-6 in rat intestinal epithelial cells (IEC). The long-chain fatty acids, oleic, linoleic and arachidonic acids, and the middle-chain fatty acid octanoic acid were administered to subconfluent cultures of IEC-6 cells alone, or in combination with IL-1beta and transforming growth factor (TGF)-beta. The GRO/CINC-1 and IL-6 concentrations in culture media were determined by sandwich enzyme immunoassay. In epithelial cells, GRO/CINC-1 and IL-6 mRNA expression were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and mitogen-activated protein kinase (MAPK) activities determined by immunoblotting. Administration of long-chain fatty acids significantly increased the GRO/CINC-1 and IL-6 secretion into culture media, and this secretion was markedly increased (P < 0.05) in the presence of IL-1beta or TGF-beta. Octanoic acid had no effect on GRO/CINC-1 or IL-6 production. Furthermore, treatment with long-chain fatty acids significantly enhanced the GRO/CINC-1 and IL-6 expression that was induced by IL-1beta or TGF-beta. MAPK activity was significantly enhanced by treatment with long-chain fatty acids. Inhibitors of phospholipase C, protein kinase C or MAPK significantly reduced the fatty acid-induced increase in GRO/CINC-1 secretion, whereas a calcium/calmodulin inhibitor did not attenuate the secretion. These results suggest that long-chain fatty acids enhance cytokine release under conditions of inflammatory stimulation in the intestinal mucosa.

Suppression of tumor necrosis factor-alpha production and neutrophil infiltration during ischemia-reperfusion injury of the liver after heat shock preconditioning

BACKGROUND/AIMS

Heat shock preconditioning provides the liver with ischemic tolerance. In this study we examined the effects of heat shock preconditioning on hepatic nonparenchymal cells in light of tumor necrosis factor-alpha (TNF-alpha) production and neutrophil infiltration.

METHODS

Rats were exposed to heat shock pretreatment at 42 degrees C in the heat shock group (group HS) and at 37 degrees C in the control group (group C). After a 48-h recovery, the left hepatic lobes were given a 90-min ischemia and reperfused. Plasma concentrations of TNF-alpha, cytokine-induced neutrophil chemoattractant (CINC) and alanine aminotransferase (ALT) were measured. Liver tissues were checked for the presence of TNF-alpha mRNA. Histological staining for CINC and polymorphonuclear leukocyte (PMN) was also evaluated.

RESULTS

In group HS, plasma TNF-alpha levels were significantly more suppressed than in group C (P<0.0001). Expressions of TNF-alpha mRNA in the liver was suppressed in group HS. Production of CINC 2 h after reperfusion was reduced in group HS (P<0.05). PMN infiltration was significantly reduced in group HS (P<0.01). In group HS, liver histology revealed less cellular damage and the plasma level of ALT was significantly reduced (P<0.0001).

CONCLUSIONS

Heat shock preconditioning suppressed the production of TNF-alpha and CINC in the liver during reperfusion and consequently reduced neutrophil infiltration.

Vestibular modulation of plasma vasopressin levels in rats

Recent studies, which have shown an increase of plasma vasopressin (VP) in experimental motion sickness and the efficacy of VP antagonists for motion sickness, suggest an important role of VP in the development of vestibulo-autonomic responses. We have recently found evidence of the co-existence of vasopressinergic neurons with the stress-sensitive chemokinergic neuronal system in the hypothalamo-pituitary pathway in rats, which uses cytokine-induced neutrophil chemoattractant (CINC) as an effector molecule. In this study, to elucidate possible roles of VP and CINC in the vestibulo-autonomic responses, we simultaneously measured plasma VP and CINC concentrations after electrical or caloric vestibular stimulation in urethane-anesthetized rats. Electrical vestibular stimulation with more than 200 microA increased the plasma levels of VP in a current intensity-dependent manner, and stimulation with 500 microA increased the plasma VP levels to 350% of the normal control group, which received no stimulation. Caloric vestibular stimulation with cold water increased the plasma VP levels to 262% of the control group, which received caloric stimulation with water at 37 degrees C, and stimulation with warm water tended to increase the plasma VP levels. Plasma CINC levels were neither affected by electrical nor caloric vestibular stimulation. These findings indicate that vestibular stimulation increased plasma levels of VP but not CINC, and this vestibular-induced activation of VP neurons may be involved in a mechanism of vestibulo-autonomic responses.

The role of cytokine-induced neutrophil chemoattractant-1 in neutrophil-mediated remote lung injury after intestinal ischaemia/reperfusion in rats

OBJECTIVE

Remote lung injury is induced by ischaemia/reperfusion (I/R) of the gastrointestinal tract and the liver following hypovolaemic shock. In the present study, the role of cytokine-induced neutrophil chemoattractant (CINC), a member of the interleukin (IL)-8 family, in neutrophil-mediated remote lung injury following intestinal I/R was investigated in anaesthetized rats.

METHODOLOGY

The I/R group was subjected to 60 min of occlusion of the superior mesenteric artery with laparotomy, followed by 240 min of intestinal reperfusion. The sham-operated (sham) group was subjected to the same procedures with the exception of intestinal I/R.

RESULTS

In the I/R group, the permeability index of the lung, the neutrophil count in pulmonary vascular lavage fluid and bronchoalveolar lavage fluid (BALF), lung myeloperoxidase activity and neutrophil oxidative production were all significantly greater than those in the sham group. Cytokine-induced neutrophil chemoattractant-1 levels in blood and BALF were significantly increased at 240 min after intestinal reperfusion. There was a significant relationship between neutrophils in BALF and CINC-1 level in BALE CONCLUSION: These findings suggest that intestinal reperfusion was associated with activation and accumulation of neutrophils in the lung and resulted in remote lung injury with increased microvascular permeability. Thus, CINC-1 in BALF may induce neutrophil migration from the pulmonary vessels to the interstitium and alveolar spaces in remote lung injury after intestinal I/R.

Urinary trypsin inhibitor reduces C-X-C chemokine production in rat liver ischemia/reperfusion

BACKGROUND AND AIM

Protease inhibitors attenuate ischemia/reperfusion injury. However, the underlying mechanisms by which protease inhibitors prevent reperfusion injury remain obscure. Neutrophils play an important role in reperfusion injury. We studied the effects of urinary trypsin inhibitor (UTI) on production of the C-X-C chemokine, cytokine-induced neutrophil chemoattractant (CINC), by Kupffer cells during ischemia/reperfusion of the liver.

METHODS

Liver ischemia was induced in rats by occlusion of the portal vein for 30 min. UTI (50,000 U/kg) was injected intravenously 5 min before vascular clamping. Serum CINC concentrations were measured by enzyme-linked immunosorbent assay. Levels of CINC mRNA in the liver were determined by Northern blot analysis. We also examined the inhibitory effects of UTI on in vitro CINC production by peritoneal macrophages in response to neutrophil elastase (NE).

RESULTS

Serum CINC concentrations increased and peaked 6 h after reperfusion. However, pretreatment of animals with UTI blunted this increase in CINC and significantly reduced CINC mRNA levels in the liver after ischemia/reperfusion. UTI also decreased neutrophil accumulation in the liver 24 h after reperfusion. In vitro CINC production by Kupffer cells from rats pretreated with UTI 3 h after ischemia/reperfusion was significantly decreased compared to those from untreated animals. UTI reduced NE activity in vitro in a dose-dependent manner, and UTI significantly reduced in vitro CINC production by peritoneal macrophages stimulated with NE.

CONCLUSION

UTI reduces the production of CINC by Kupffer cells stimulated with NE, attenuating ischemia/reperfusion injury of the liver.

Fasting exacerbates acute pancreatitis by occlusion of the common bile duct in rats

We examined the effects of fasting and non-fasting on gallstone-related acute pancreatitis by the occlusion of the common bile duct (OCD). We prepared a rat OCD-induced pancreatitis model under both fasting and non-fasting conditions, and we measured amylase activity in ascites as well as production of inflammatory cytokines and chemokines. We also examined the pathology of the pancreas, myeloperoxidase (MPO) activity in some tissues and mortality rates. In the fasted OCD group, ascites containing a large amount of amylase, interleukin 1beta (IL-1beta), interleukin 6 (IL-6), and cytokine-induced neutrophil chemoattractant-1 (CINC-1) as well as marked hemorrhage and necrosis of the pancreatic acinar cells were observed. Pulmonary MPO activity increased 3.4-fold compared to the control group. In the non-fasted OCD group, there was no development of ascites. Slight necrosis of acinar cells and slight increases in pulmonary MPO activity were observed. In addition, in the fasted OCD group, the cumulative mortality rate was 50% 6 days after ligation. However, in the non-fasted OCD group, none of the animals died. These results suggest that gallstone-related severe pancreatitis depends on fasting-related structural and/or functional changes in the pancreas. Moreover, increased production of inflammatory cytokines and chemokines in ascites under fasting condition may be involved in multiple organ failure resulting from severe acute pancreatitis.

Thrombin and factor Xa enhance neutrophil chemoattractant production after ischemia/reperfusion in the rat liver

BACKGROUND

Clotting proteases may affect leukocyte effector function. Activation of the coagulation cascade after ischemia/reperfusion stimulates cytokine production by activated macrophages. Cytokine-induced neutrophil chemoattractant (CINC) may also be important in the pathophysiology of liver ischemia/reperfusion injury. We investigated the effects of a selective factor Xa inhibitor, DX-9065a, on CINC expression after ischemia/reperfusion in the rat liver.

METHODS

Liver ischemia was induced in rats by occluding the portal vein for 30 min. DX-9065a (9 mg/kg) was injected intravenously 5 min before vascular clamping. Serum CINC concentrations were measured by enzyme-linked immunosorbent assay. Levels of CINC mRNA in the liver were determined by Northern blot analysis. We also examined in vitro CINC production by peritoneal macrophages in response to alpha-thrombin or factor Xa.

RESULTS

Serum CINC concentrations increased and peaked 6 h after reperfusion. However, pretreatment of animals with DX-9065a resulted in significantly smaller increases in CINC after reperfusion. Pretreatment with DX-9065a also significantly reduced CINC mRNA levels in the liver after ischemia/reperfusion. In vitro CINC production by peritoneal macrophages was enhanced by alpha-thrombin, as well as factor Xa.

CONCLUSIONS

Thrombin and factor Xa stimulate CINC production by macrophages. A selective inhibitor of factor Xa, DX-9065a, attenuates neutrophil chemoattractant production after ischemia/reperfusion injury of the rat liver.

Production and regulation of cytokine-induced neutrophil chemoattractant in rat ovulation

A cytokine-induced neutrophil chemoattractant (CINC/gro), which belongs to the interleukin (IL)-8 family, acts as a functional chemoattractant for neutrophils in rats. In the present study, we examined whether CINC/gro contributes to the ovulation process in the rat ovulation system. In rat ovaries, CINC/gro was immunohistochemically recognized in the theca layer of the antral follicle but not in the granulosa cells. To clarify the role of CINC/gro in the ovulation process, CINC/gro protein and mRNA were examined during pregnant mare serum gonadotropin (PMSG)-hCG treatment. CINC/gro protein did not increase as a result of PMSG injection. However, it increased rapidly after hCG injection and peaked at 6 h after hCG. CINC/gro mRNA was also strongly expressed after hCG injection. The increase of CINC/gro protein followed increases in IL-1beta and tumor necrosis factor alpha (TNFalpha). In the whole ovarian dispersate culture, FSH, hCG, IL-1beta, and TNFalpha stimulated the production of CINC/gro protein in a dose-dependent manner. In particular, the stimulatory effects of IL-1beta and TNFalpha were stronger than those of gonadotropins. These results suggest that CINC/gro plays an important role in the rat ovulation process by attracting neutrophils. CINC/gro increased just prior to ovulation, and it may be regulated directly by cytokines such as IL-1beta and TNFalpha and indirectly by gonadotropins.

Rat CXC chemokine GRO/CINC-1 paradoxically stimulates the growth of gastric epithelial cells

BACKGROUND

CXC chemokines such as interleukin (IL)-8 are neutrophil chemoattractants, the levels of which increase in Helicobacter pylori-infected gastric mucosa. Many investigators have focused on the chemotactic aspects of IL-8: however, CXC chemokines are also reported to have angiogenic activity and to serve as remodelling factors. Rat GRO/CINC-1 is a rodent counterpart of human GROalpha, a member of the family of CXC chemokines. Gastric mucosa infected with H. pylori is in a state of hyperproliferation, with increases in the amounts of growth factors such as hepatocyte growth factor (HGF).

AIM

To investigate whether rat GRO/CINC-1 had growth-stimulating activity for gastric epithelial cells.

METHODS

The rat gastric epithelial cell line RGM-1 was incubated in serum-free medium for 12 h to adjust the cell cycle to the G0 phase, and GRO/CINC-1 was then added for 24 h. The total cell number was determined by fluorogenic analysis after propidium iodide staining, and cell proliferation was assessed by measuring 5-bromo-2'-deoxyuridine (BrdU) incorporation. The activity of p42/p44 mitogen-activated protein kinase (MAPK) was measured 5-20 min after the start of GRO/CINC-1 exposure.

RESULTS

Cultures treated with GRO/CINC-1 showed a significant increase in cell number and BrdU incorporation in a concentration-dependent fashion. The MAPK activity increased within 5 min after GRO/CINC-1 application and returned to the control level at 20 min.

CONCLUSION

The growth-stimulatory effect of GRO/CINC-1 on rat gastric epithelial cells suggests a dual function of this chemokine: proinflammatory action and induction of epithelial proliferation.

Attenuation of cadmium-induced liver injury in senescent male fischer 344 rats: role of Kupffer cells and inflammatory cytokines

In the previous study we showed that senescent male Fischer 344 rats were resistant to Cd-induced hepatotoxicity compared with young-adult rats. In the present study we investigated the role of Kupffer cells and inflammatory cytokines in this effect of aging. The phagocytic activity of Kupffer cells, determined as the removal of carbon from blood, was stimulated by the administration of a hepatotoxic dose of Cd (3 mg/kg sc) in young-adult (5 months) rats but not in old (28 months) rats. Hepatic concentrations of interleukin (IL)-1beta and cytokine-induced neutrophil chemoattractant (CINC), but not of tumor necrosis factor-alpha or IL-6, were elevated in young rats treated with Cd. In old rats, however, the increase in IL-1beta produced by Cd was not statistically significant and the increase in CINC was much lower than in young-adult rats. Pretreatment with gadolinium chloride or cyclosporin A inhibited the elevations in hepatic cytokines and attenuated Cd-induced liver damage, assessed on the basis of serum alanine aminotransferase and sorbitol dehydrogenase activities. Cd-induced hepatotoxicity in the different treatment groups correlated well with hepatic levels of CINC (r = 0.98, p < 0.001) but not with those of IL-1beta. The results suggest that (1) Kupffer cell activation is essential for inflammatory liver damage from Cd, (2) IL-1beta and CINC are important mediators of the inflammatory response induced by Cd, and (3) the attenuation of Cd-induced liver injury in senescent rats is caused by an impairment in Kupffer cell activation, leading to a lower production of CINC and less inflammatory liver injury.

Insulin-induced hypoglycemia activates a chemokinergic neuronal pathway in the hypothalamo-pituitary system

Recently, we found the presence of cytokine-induced neutrophil chemoattractant (CINC) neuronal pathway in the hypothalamo-pituitary system. This observation prompted us to investigate the effect of insulin-induced hypoglycemia on CINC neuronal pathway in the hypothalamo-pituitary system. An insulin injection decreased the plasma glucose level, which followed a prompt rise in plasma ACTH level and an increase in serum CINC level. Before the insulin injection, the signal for CINCmRNA was undetectable in the paraventricular hypothalamic nucleus (PVN). The hypoglycemic challenge induced strong hybridization signals of CINC mRNA in the parvocellular and magnocellular subdivision of the PVN within 30 min, and reached the peak within 3 h. No change was observed in the supraoptic nucleus after the hypoglycemic challenge. These studies demonstrate the presence of a hypoglycemia-sensitive chemokinergic neuronal pathway in the hypothalamo-neurohypophysial system and this newly described pathway will provide novel information for understanding pathophysiology of hypoglycemia.

NF-κB-Inducing Kinase Is a Common Mediator of IL-17-, TNF-α-, and IL-1β-Induced Chemokine Promoter Activation in Intestinal Epithelial Cells

IL-17 expression is restricted to activated T cells, whereas the IL-17R is expressed in a variety of cell types including intestinal epithelial cells. However, the functional responses of intestinal epithelial cells to stimulation with IL-17 are unknown. Moreover, the signal transduction pathways activated by the IL-17R have not been characterized. IL-17 induced NF-κB protein-DNA complexes consisting of p65/p50 heterodimers in the rat intestinal epithelial cell line IEC-6. The induction of NF-κB correlated with the induction of CXC and CC chemokine mRNA expression in IEC-6 cells. IL-17 acted in a synergistic fashion with IL-1β to induce the NF-κB site-dependent CINC promoter. Induction of the CINC promoter by IL-17 in IEC-6 cells was TNF receptor-associated factor-6 (TRAF6), but not TRAF2, dependent. Furthermore, IL-17 induction of the CINC promoter could be inhibited by kinase-negative mutants of NF-κB-inducing kinase and IκB kinase-α. In addition to activation of the NF-κB, IL-17 regulated the activities of extracellular regulated kinase, c-Jun N-terminal kinase, and p38 mitogen-activated protein kinases in IEC-6 cells. Whereas the IL-17-mediated activation of extracellular regulated kinase mitogen-activated protein kinases was mediated through ras, c-Jun N-terminal kinase activation was dependent on functional TRAF6. These data suggest that NF-κB-inducing kinase serves as the common mediator in the NF-κB signaling cascades triggered by IL-17, TNF-α, and IL-1β in intestinal epithelial cells.

H-ras-transformed NRK-52E renal epithelial cells have altered growth, morphology, and cytoskeletal structure that correlates with renal cell carcinoma in vivo

We studied the effect of the ras oncogene on the growth kinetics, morphology, cytoskeletal structure, and tumorigenicity of the widely used NRK-52E rat kidney epithelial cell line and two H-ras oncogene-transformed cell lines, H/1.2-NRK-52E (H/1.2) and H/6.1-NRK-52E (H/6.1). Population doubling times of NRK-52E, H/1.2, and H/6.1 cells were 28, 26, and 24 h, respectively, with the transformed cells reaching higher saturation densities than the parent cells. NRK-52E cells had typical epithelial morphology with growth in colonies. H/1.2 and H/6.1 cell colonies were more closely packed, highly condensed, and had increased plasma membrane ruffling compared to parent cell colonies. NRK-52E cells showed microfilament, microtubule, and intermediate filament networks typical of epithelial cells, while H/1.2 and H/6.1 cells showed altered cytoskeleton architecture, with decreased stress fibers and increased microtubule and intermediate filament staining at the microtubule organizing center. H/1.2 and H/6.1 cells proliferated in an in vitro soft agar transformation assay, indicating anchorage-independence, and rapidly formed tumors in vivo with characteristics of renal cell carcinoma, including mixed populations of sarcomatoid, granular, and clear cells. H/6.1 cells consistently showed more extensive alterations of growth kinetics, morphology, and cytoskeleton than H/1.2 cells, and formed tumors of a more aggressive phenotype. These data suggest that analysis of renal cell characteristics in vitro may have potential in predicting tumor behavior in vivo, and significantly contribute to the utility of these cell lines as in vitro models for examining renal epithelial cell biology and the role of the ras proto-oncogene in signal transduction involving the cytoskeleton.

Acute biological effects of intratracheally instilled titanium dioxide whiskers compared with nonfibrous titanium dioxide and amosite in rats

The dimensions of man-made mineral fiber whiskers are similar to those of some kinds of asbestos. Thus these mineral fibers raise the concern for potential health hazard for workers exposed in the occupational environments. This study was designed to define acute biological effects of intratracheally administered titanium dioxide whiskers (TO1) compared with nonfibrous titanium dioxide (TOP) and UICC amosite (Ams), and their relations to acute lung inflammation in rats. The observed geometric mean length (microm) and width (microm) and geometric standard deviation are: TO1(2.1[2.0], 0.14[1. 53]); Ams (4.3[3.3], 0.31[1.9]); and TOP (50 nm, 1-2 microm aggregates). Ten-week-old Wistar-Jcl male rats received a single tracheal injection of test materials at doses between 0.05 and 1.0 mg/rat. Control animals were injected with the same volume of saline. Lung tissue and bronchoalveolar lavage (BAL) fluid were collected from rats on days 1, 3, and 7 after administration. In the group injected with TO1, total protein, cytokine-induced neutrophil chemoattractant (CINC)/growth-regulated gene product (GRO), interleukin (IL) 1beta, and tumor necrosis factor (TNF) alpha increased on day 1. Subsequently, total elastolytic activity and fucose levels in BAL increased by day 3. All parameters, except for fucose in BAL, recovered to the normal levels. Animals in the Ams group showed increased total protein and CINC/GRO and decreased total elastolytic activity in a dose-dependent manner on day 1. The fucose level increased on day 3 in the Ams group. All parameters returned to their control levels on day 7. Animals in the TOP group did not show significant changes any of parameters during the experimental period. Gene expression of TNF-alpha and monocyte chemoattractant protein (MCP) 3 in the lung increased dose-dependently in the animals treated with the three materials. The mRNAs for eotaxin and MIP-1alpha were overexpressed in the lung of animals treated with Ams and TO1, while RANTES mRNA was overexpressed dose-dependently in the lung of animals treated with Ams on day 1. Onset of inflammatory response was more rapid in the Ams group than the TO1 group. Recovery of the fucose level in BAL was slower in the TO1 group than in the Ams group, though we observed similar histopathological changes in the lung of animals with TO1 or Ams. We conclude that whisker-induced acute biological effects in the lung may be related to the shape of the whiskers and not to their chemical composition or surface crystal structure, showing biological effects similar to those of UICC amosite.

A hyperalgesic effect of intracerebroventricular cytokine-induced neutrophil chemoattractant-1 in the rat paw pressure test

Cytokine-induced neutrophil chemoattractant-1 (CINC-1) is a member of the chemokine superfamily. The effect of intracerebroventricular (i.c.v) injection of CINC-1 on the mechanical nociceptive threshold in the rat was examined using the paw-pressure test. An i.c.v. injection of CINC-1 at doses of 1 and 10 pg/rat tended to decrease the nociceptive threshold for mechanical stimuli at 15 min after the injection, and significantly lowered the threshold at 30 min. The threshold stayed at these lowered level over 180 min after the injection. Lower (100 fg/rat) and higher (30 and 100 pg/rat, and 1 and 10 ng/rat) doses of CINC-1 had no effect on the mechanical nociceptive threshold. The present results suggest that CINC-1 facilitates mechanical nociception in the central nervous system (CNS).

Xanthine oxidase inhibition attenuates kupffer cell production of neutrophil chemoattractant following ischemia-reperfusion in rat liver

We investigated the effects of the xanthine oxidase inhibitor, BOF-4272, on the production of cytokine-induced neutrophil chemoattractant (CINC) following reperfusion injury in rat liver. Ischemia was induced for 30 minutes by portal vein occlusion. Animals were pretreated with intravenous injection of BOF-4272 (1 mg/kg) or heparin (50 U/kg) 5 minutes before vascular clamp. Both BOF-4272 and heparin limited increases in the chemoattractant compared with nonpretreated rats. Pretreatment with BOF-4272 plus heparin resulted in an additive effect. Most cells immunostained for chemoattractant were macrophages in sinusoids. In vitro chemoattractant production by Kupffer cells isolated from animals pretreated with heparin or BOF-4272 was significantly lower than by Kupffer cells from nonpretreated animals. Expression of transcripts in liver for chemoattractant peaked 3 hours after reperfusion in nonpretreated animals, while pretreatment with heparin or BOF-4272 significantly decreased chemoattractant mRNA levels. In vitro chemoattractant transcription and production could be induced in naive Kupffer cells by hypoxanthine and xanthine oxidase, but BOF-4272 prevented these increases. We conclude that Kupffer cells release chemoattractant in response to oxygen radicals reducible by xanthine oxidase inhibition.

Induction of CINC (interleukin-8) production in rat liver by non-parenchymal cells

The production of interleukin-8 (CINC: cytokine-induced neutrophil chemo-attractant) from different cell populations in the rat liver was studied and cells related to the initiation of CINC production in lipopolysaccharide (LPS)-injected endotoxaemic rats were characterized. Sinusoidal endothelial cells (16.4 +/- 10.6 ng/mL) produced significantly higher amounts of CINC in 24 h primary cultures compared with hepatocytes (0.9 +/- 0.9 ng/mL; P < 0.05) and Kupffer cells (6.5 +/- 5.1 ng/mL; P < 0.05). Lipopolysaccharide, tumour necrosis factor-alpha (TNF-alpha), and interleukin-1 alpha (IL-1 alpha) stimulated different liver cell populations to produce CINC; LPS mainly stimulated Kupffer cells. TNF-alpha stimulated hepatocytes and IL-1 alpha stimulated all three types of cells. Intraperitoneal injection of LPS (4 mg/kg) caused CINC accumulation in non-parenchymal cells of the rat liver within 1 h of injection, as shown by immunohistochemical staining. In contrast, CINC-positive hepatocytes were not seen until 3 h after injection of LPS. Ethanol was not a direct inducer of CINC production by rat hepatocytes in vitro. These findings strongly suggest that non-parenchymal liver cells, including sinusoidal endothelial cells, are the main source of CINC. Our data also suggest that during endotoxaemia, CINC production is initiated by non-parenchymal cells and this is followed by production from hepatocytes.

Induction of cytokine-induced neutrophil chemoattractant in response to various stresses in rat C6 glioma cells

The effect of stress on the production of cytokine-induced neutrophil chemoattractant (CINC) was examined in rat C6 glioma cells. We studied the production of CINC, an interleukin-8 (IL-8) family protein, with bacterial endotoxin, H2O2, and tumor necrosis factor-alpha (TNF-alpha). Each stress induced CINC mRNA in a concentration-dependent manner. Since stress activates the protein kinases regulating nuclear transcription factors, we examined the effects of protein kinase inhibitors and the over-expression of dominant-negative Ras on CINC mRNA expression. Neither over-expression of dominant-negative Ras nor pretreatment with PD98059 (MEK-1 inhibitor), SB203580 (p38MAPK inhibitor), or GF109203X (protein kinase C (PKC) inhibitor) altered stress-induced CINC mRNA expression. This suggests that the Ras-MAPK, p38MAPK, and PKC pathways are not involved in CINC mRNA expression in glial cells. On the other hand, pretreatment with herbimycin A, a potent tyrosine kinase inhibitor, or Ro31-8220, a non-selective serine/threonine kinase inhibitor, suppressed stress-induced CINC mRNA expression. This indicates that stress-induced CINC mRNA expression is mediated by herbimycin A-, or Ro31-8220-sensitive kinases in glial cells. Since stress activates NF-kappaB and NF-IL6, we examined that the effect of herbimycin A, which suppresses CINC mRNA expression, on NF-kappaB and NF-IL6 activation. Herbimycin A suppressed NF-kappaB but not NF-IL6. These results suggest that in rat glial cells, the factors that induce CINC mRNA expression are mediated by herbimycin A-sensitive NF-kappaB activation, but not through the PKC, Ras-MAPK or p38 MAPK pathways.