Augmentation of monocyte chemotactic protein-1 and mRNA transcript in chronic inflammatory states induced by potassium permanganate (KMnO4) in vivo

Localized delivery of dexamethasone-21-phosphate via microdialysis implants in rat induces M(GC) macrophage polarization and alters CCL2 concentrations

Microdialysis sampling probes were implanted into the subcutaneous space on the dorsal side of male Sprague Dawley rats to locally deliver dexamethasone-21-phosphate (Dex) with the aim of altering in vivo macrophage polarization. Macrophage polarization is of significant interest in the field of biomaterials since wound-healing macrophages are a possible means to extend implant life as well as improve tissue remodeling to an implant. Quantitative analysis of CCL2 in collected dialysates, gene expression and immunohistochemistry performed on the tissue surrounding the microdialysis implant were used to evaluate if Dex polarized macrophages. Dex infusion down-regulated IL-6 and CCL2 gene expression and decreased CCL2 concentrations in dialysates collected at the implant site. Dex appeared to have no significant effect on the gene regulation of CD163, a commonly used M2c macrophage surface marker; Arg2; and iNOS2. However, Dex infusion was effective at increasing the number of CD163(+) cells surrounding the implanted microdialysis probe. This work demonstrates the use of microdialysis sampling to deliver agents such as Dex to alter macrophage polarization in vivo while allowing the ability to collect cytokines in the surrounding microenvironment.

RANTES (CCL5) potentiates calcium ionophore in the production of LTB4 in rat adherent macrophages from granuloma induced by KMnO4: inhibiton by NDGA

The activation of monocytes/macrophages by several stimuli is an initial event in the inflammatory response. To ascertain the importance of LTB(4) and 5-lypoxigenase in the inflammatory site, we isolated and stimulated rat adherent granuloma macrophages (RAGMs) with calcium ionophore in the presence or absence of regulated on activation, normal T expressed and secreted (RANTES) [CCL5] at different concentrations. We tested the hypothesis that RANTES may influence the production of LTB(4) stimulated by calcium ionophore A23187 (2.5 microM/ml) in rat adherent granuloma macrophages derived from granuloma induced by potassium permanganate diluted 1:40 saturated solution. To test this hypothesis, we measured LTB(4) production, in rat granuloma macrophages stimulated with A23187 (2.5 microM) alone and in combination with RANTES at different concentrations. In these studies, the cell-free supernatant of stimulated RAGMs with the ionophore A23187, resulted in a drastic increase of LTB(4). However, when the cells were treated with the combination RANTES plus A23187 the stimulatory effect was more pronounced than A23187 alone. LTB(4) production was quantitated. The calcium ionophore A23187 directly induced LTB(4) in macrophages, this production was markedly enhanced when the cells were pretreated with RANTES. However, the addition of RANTES in the absence of calcium ionophore A23187 did not directly induce LTB(4) release, nor was lypoxigenase expression augmented. Preincubation of RAGMs with NDGA (nordihydroguiaretic acid) (10(-5)M) completely abolished the production of LTB4 on RAGMSs challenged with A23187 in combination with RANTES or A23187 alone in the supernatants. Similar effects were obtained when the cells were pretreated with dexamethasone. These data suggest, for the first time, that RANTES may stimulate the release of LTB(4), only when it is associated to other stimuli and for this reason we conclude that RANTES modulates inflammatory diseases, and may require other stimuli to be effective in amplifying its spectrum of action(s).

Glucocorticoid treatment down-regulates chemokine expression of bacterial cholangitis in cholestatic rats

BACKGROUND

Postoperative cholangitis is common after operation for biliary atresia. Empirical pulse therapy with glucocorticoid is effective in reversing some detrimental clinical manifestations, but the rationale for such a therapy still is not substantiated.

METHODS

Adult male rats were divided into groups according to the treatment: sterile normal saline (NS) or Escherichia coli (EC, 1 mL containing 10(8) cells of ATCC 25922 strain), 1 mL, were infused into the proximal choledochostomy (PC) tube 2 weeks after ligation of the PC tube (bile duct ligation, BDL), then immediate tube-tube choledocho-choledochostomy (biliary drainage, BD) was constructed. A high dose of dexamethasone (DEX, intraperitoneal injection; 2 mg/kg of body weight) was given after BD in treatment groups. Histopathology of the liver, as well as liver chemokine mRNA expression and serum chemokine levels, were studied 24 hours after treatment.

RESULTS

Inflammatory cell infiltration to the liver was retarded with DEX treatment, which was correlated with a significantly lower expression of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) mRNA in the liver (P =.006). Serum IL-8 and MCP-1 levels were also significantly down-regulated with DEX treatment (P = 0.008).

CONCLUSIONS

Glucocorticoid treatment is effective in modulating IL-8 and MCP-1 expression and ameliorating inflammatory cell infiltration in rat liver with bacterial cholangitis and cholestasis.

Interferon beta-1b modulates MCP-1 expression and production in relapsing-remitting multiple sclerosis

Monocyte chemoattractant protein-1 (MCP-1) seems to be involved in the pathogenesis of multiple sclerosis (MS). We found that in unstimulated (PHA(-)) and PHA-stimulated (PHA(+)) peripheral blood mononuclear cells (PBMC), MCP-1 and TNFalpha levels are higher in stable untreated MS patients. Interferon gamma (IFNgamma) is higher in relapsing patients in PHA(-) cultures and in stable patients in PHA(+) cultures. Chronic IFNbeta-1b treatment down-regulates TNFalpha, IFNgamma and MCP-1 production except for TNFalpha in relapsing patients. IFNbeta-1b, in vitro, increases MCP-1, TNFalpha and IFNgamma spontaneous production in all patients. Multivariate analysis suggests that MCP-1 production is dependent from clinical status and not from TNFalpha and IFNgamma production. Logistic regression analysis shows that MCP-1 production is significantly modified by treatment. Further studies are needed to clarify the role of MCP-1 in MS.

Ascending cholangitis provokes IL-8 and MCP-1 expression and promotes inflammatory cell infiltration in the cholestatic rat liver

BACKGROUND/PURPOSE

Postoperative cholangitis is one of the most common complications after bile duct reconstruction. The pathogenesis and early consequences of ascending cholangitis still are unidentified.

METHODS

Male Sprague-Dawley rats were divided into 5 treatment groups: control (n = 4), blood sampling and liver biopsy only; group I, [BDL/Eschericha coli; n = 6], ligation of common bile duct (BDL) for a week, followed by Roux-en-Y choledochojejunostomy (RYCJ) and injection of E coli (ATCC 25922) into Roux limb after 24 hours; group II, [BDL/NS; n = 5], same procedures as in group I, with injection of normal saline (NS) into Roux limb; group III, [SBDL/E coli; n = 6], primary RYCJ was constructed 1 week after sham ligation of common bile duct (SBDL) followed by the same treatment as group I; Group IV, [SBDL/N.S; n = 6], same procedures as in group III, but injecting NS into Roux limb. All animals were killed after 24 hours of treatment. Blood was sampled for culture and serum cytokine levels. The liver was harvested for quantitative bacterial culture, as well as for MCP-1, interleukin (IL)-8 (CINC in the rat) and transforming growth factor beta1 mRNA expression by reverse transcriptase polymerase chain reaction (RT-PCR) and for immunohistochemistry. The choledochojejunostomy was resected for culture. Serum cytokine levels were detected by ELISA kits.

RESULTS

A significant increase of E coli ATCC 25922, occurred in the livers of group I rats, compared with group IV (P =.037). MCP-1 expression increased in all groups, compared with control (P =.000). The IL-8 mRNA expression was significantly higher in group I than in control (P =.021). The expression of TGF-beta1 mRNA was similar among the groups (P =.361), consistent with the immunohistochemistry results. The serum MCP-1 and IL-8 levels were higher in the 4 groups than in the control (P =.000) and were significantly higher in group I than in group IV (P =.001).

CONCLUSIONS

This study found that a significant colonization of E coli of the same strain was present in the cholestatic rat liver injected into the Roux limb, which was associated with a higher expression of liver MCP-1 and IL-8 mRNA, a significant increase of serum MCP-1 and IL-8, and a more evident inflammatory cell infiltration into the porta hepatis.

RANTES production and expression is reduced in relapsing-remitting multiple sclerosis patients treated with interferon-beta-1b

RANTES (regulated upon activation, normal T-cell expressed and secreted), a CC chemokine, appears to play a role in the pathogenesis of relapsing-remitting multiple sclerosis (RR-MS), enhancing the inflammatory response within the nervous system. We have demonstrated that RANTES production is increased in RR-MS compared to controls. Interferon-beta-1b (IFN-beta-1b) treatment reduces RANTES production in sera and peripheral blood adherent mononuclear cell (PBAM) supernatants both in relapse and remission. IFN-beta-1b also reduces RANTES expression in PBAM. Our results suggest that RANTES modulation might represent one of the mechanisms of action of IFN-beta-1b in RR-MS.

Vitamin B6-deficient diet plus 4-deoxypyridoxine (4-DPD) reduces the inflammatory response induced by T. spiralis in diaphragm, masseter and heart muscle tissue of mice

Animals fed diets deficient in vitamin B6 develop microcytic anemia, alterations of growth, and other pathologies. 4-deoxypirydoxine is a potent antagonist of vitamin B6 coenzyme which depresses IL-1, TNF and IL-6 and has anti-inflammatory properties. The aim of this study was to show the anti-inflammatory effects of 4-DPD on chronic inflammation caused by the nematode parasite T. spiralis, specifically on the recruitment and the activation of inflammatory cells. Two groups of mice, 6 weeks of age, were used: one was maintained on a vitamin B6-deficient synthetic pellet diet for 15 days before injection of the nematode, and administered an intraperitoneal injection (i.p.) of 4-DPD (250 microg/mouse) for 15 days (the first, 5 days before infection), and the second group was maintained on a normal diet for the total duration of the experiment. These two groups were then injected with 150 larvae (L1-T7 spiralis) per os. Chronic inflammation was caused by infection of treated or untreated mice with T7 spiralis parasite. After 14 days post-infection all mice developed a chronic inflammatory response. Mice fed with a B6-deficient diet showed a significant decrease in the number of cysts found in the diaphragm when compared to mice treated with normal diet. In addition, in all mice treated with vitamin B6-deficient diet plus 4-DPD the average body weight was significantly lower, compared to the mice on normal diet in all weeks examined. Moreover, in sections of the diaphragm, masseter and myocardium muscles, the infiltration of inflammatory cells, such as macrophages, lymphocytes, and eosinophils were more intense in untreated mice compared to those fed a vitamin B6-deficient diet. These results show that BALB/c mice infected with T. spiralis and fed a vitamin B6-deficient diet plus the vitamin B6 antagonist, 4-DPD, prolong the time of invasion of the larvae in the muscle cells, influence the recruitment of inflammatory cells and the intensity of the inflammatory reaction compared to infected untreated mice (control).