Effects of isoflurane in an intoxication model: experimental study

BACKGROUND

Isoflurane is a volatile anaesthetic that has been commonly used since 1980. The major metabolites of isoflurane are fluoride ion and trifluoroacetate, both excreted in the urine.

AIM

This study manage to show the histopathological findings of ingested isoflurane on liver, kidney and lugs in an animal model. Twenty-one rabbits were selected and divided into three groups: Group Isoflurane-5 (I-5); Group Isoflurane-10 (I-10); and Group Control (C). Each group consisted of seven rabbits. I-5 and I-10 received 5 ml/kg and 10 ml/kg of liquid isoflurane, respectively, via nasogastric tube, while C received 5 ml/kg saline (0.9% NaCI). All animals in I-5 and I-10 were sacrificed without anesthetic drug administration. Tissue samples from livers, kidneys and lungs were collected, preserving tissue unity and avoiding infliction of any trauma. Samples were fixed in 10% formalin solution, embedded in paraffin blocks and sliced into 5 μm sections. To investigate the effects of isoflurane, sections were examined under light microscope and histopathological changes were scored.

RESULTS

Mean injury scores and the appearance of portal lymphocyte infiltration in liver samples showed significant increases in I-5 and I-10 compared to C (p = 0.005, p = 0.001 and p = 0.001, respectively). Mean lung injury scores revealed significant increases after isoflurane treatment in I-5 and I-10 compared to C (p = 0.026 and p = 0.017, respectively).

CONCLUSIONS

Ingested isoflurane led to mild liver and lung injuries in rabbits.

Recombinant adiponectin ameliorates liver ischemia reperfusion injury via activating the AMPK/eNOS pathway

BACKGROUND

It is of importance to minimize ischemia reperfusion (I/R) injury during liver operations. Reducing the inflammatory reaction is an effective way to achieve this goal. Notably, adiponectin (APN) was found to have anti-inflammatory activity in heart and renal I/R injury. Herein, we investigated the role of APN in liver I/R injury.

METHODS

WISTAR RATS WERE RANDOMIZED TO FOUR GROUPS: (1) sham group; (2) I/R control group; (3) I/R+APN group; and (4) I/R+APN+AMPK inhibitor group. Liver and blood samples were collected 6h and 24h after reperfusion. Liver function and histopathologic changes were assessed. Macrophage and neutrophil infiltration was detected by immunohistochemistry staining, while pro-inflammatory cytokines and chemokines released in the liver were measured using ELISA and RT-PCR, respectively. Apoptosis was analyzed by TUNEL staining and caspase-3 expression in the liver. Downstream molecules of APN were investigated by Western blotting.

RESULTS

Circulatory APN was down-regulated during liver I/R. When exogenous APN treatment was administered during liver I/R, alanine transaminase (ALT) and aspartate aminotransferase (AST) were decreased, and less hepatocyte necrosis was observed. Less inflammatory cell infiltration and pro-inflammatory cytokines/chemokines release were also observed in the I/R+APN group when compared with the I/R control group. APN treatment also reduced hepatocyte apoptosis, evidenced by reduced TUNEL positive cells and less caspase-3 expression in the reperfused liver. Finally, the AMPK/eNOS pathway was found to be activated by APN, and administration of an AMPK inhibitor reversed the beneficial effects of APN.

CONCLUSION

APN can protect the liver from I/R injury by reducing the inflammatory response and hepatocyte apoptosis, a process that likely involves the AMPK/eNOS pathway. The current study provides a potential pharmacologic target for liver I/R injury.

Investigation of STW 5 (Iberogast®) preventive effects in experimental sepsis

CONTEXT

STW 5 (Iberogast(®)) is a well known herbal combination drug containing glycosides and flavonoids for which multiple pharmacological properties have been shown.

OBJECTIVE

In this study, attempts were made to assess whether STW 5, an aqueous ethanol solution, has a preventive effect against liver and lung pathological damage in rats after experimental induction of sepsis [cecal ligation and puncture (CLP)].

MATERIALS AND METHODS

Experimental sepsis was induced in rats using CLP operation. The rats (n = 36) were divided into six groups (six/group): Sham-operated (SOP); CLP; CLP + STW 5 (2.5, 5 and 10 mg/kg) and CLP + indomethacin. The drugs were injected intraperitoneally immediately after sepsis induction.

RESULTS

It was found that induction of sepsis 24 h after CLP was associated with significant liver and lung damage, also remaining after STW 5 administration.

DISCUSSION AND CONCLUSION

It appears that STW 5, which has a pronounced efficacy in functional gastro-intestinal diseases, has no effect on septic liver and lung damage in the CLP rat model.

Copper-zinc superoxide dismutase-deficient mice show increased susceptibility to experimental autoimmune encephalomyelitis induced with myelin oligodendrocyte glycoprotein 35-55

In this report, we have addressed the role of copper-zinc superoxide dismutase (SOD1) deficiency in the mediation of central nervous system autoimmunity. We demonstrate that SOD1-deficient C57Bl/6 mice develop more severe autoimmune encephalomyelitis induced with myelin oligodendrocyte glycoprotein (MOG) 35-55, compared with wild type mice. This alteration in the disease phenotype was not due to aberrant expansion of MOG-specific T cells nor their ability to produce inflammatory cytokines; rather lymphocytes generated in SOD1-deficient mice were more prone to spontaneous cell death when compared with their wild type littermate controls. The data point to a role for SOD1 in the maintenance of self-tolerance leading to the suppression of autoimmune responses.

Perthamide C inhibits eNOS and iNOS expression and has immunomodulating activity in vivo

Here we have characterized perthamide C, a cyclopeptide from a Solomon Lithistid sponge Theonella swinhoei, which displays an anti-inflammatory/immunomodulatory activity. The study has been performed using the carragenan-induced mouse paw edema that displays an early (0–6 h) and a late phase (24–96 h). Perthamide C significantly inhibits neutrophils infiltration in tissue both in the early and late phases. This effect was coupled to a reduced expression of the endothelial nitric oxide synthase (eNOS) in the early phase while cyclooxygenase-1 and 2 (COX-1, COX-2), and inducible NOS (iNOS) expression were unaffected. In the late phase perthamide C reduced expression of both NOS isoforms without affecting COXs expression. This peculiar selectivity toward the two enzymes deputed to produce NO lead us to investigate on a possible action of perthamide C on lymphocytes infiltration and activation. We found that perthamide C inhibited the proliferation of peripheral lymphocytes, and that this effect was secondary to its metabolic activation in vivo. Indeed, in vitro perthamide C did not inhibit proliferation as opposite to its metabolite perthamide H.

In conclusion, perthamide C selectively interferes with NO generation triggered by either eNOS or iNOS without affecting either COX-1 or COX-2. This in turn leads to modulation of the inflammatory response through a reduction of vascular permeability, neutrophil infiltration as well as lymphocyte proliferation.

Antidiabetic effect of Streblus asper in streptozotocin-induced diabetic rats

CONTEXT

In the Indian traditional system of medicine, Streblus asper Lour (Moraceae) is prescribed for the treatment of diabetes mellitus.

OBJECTIVE

In the present study, α-amyrin acetate isolated from S. asper, and the petroleum ether extract of S. asper stem bark (PESA) was screened for their antidiabetic properties in streptozotocin (STZ)-induced diabetic rats.

MATERIALS AND METHODS

Successive Soxhlet extraction of the dried stem bark with petroleum ether and then with ethanol (95%) yielded petroleum ether and ethanol extracts, respectively, which were concentrated under reduced pressure. Hyperglycemia was induced in rats by STZ (50 mg/kg, b.w.). Twenty-four hours after STZ induction, respective groups of diabetic rats received PESA (100, 250 and 500 mg/kg, b.w.) and α-amyrin acetate (25, 50 and 75 mg/kg, b.w.) respectively, orally daily for 15 days. Glibenclamide (0.5 mg/kg, orally) served as a reference. Blood glucose levels were measured on every 5th day during the 15 days of treatment. The serum lipid profiles and biochemical parameters, viz., serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP), insulin and glycosylated hemoglobin level, were measured.

RESULTS

PESA significantly (p < 0.01) normalized blood-glucose levels and serum biochemical parameters as compared with those of STZ controls. α-Amyrin acetate (75 mg/kg, b.w.) exhibited maximum glucose lowering effect (71.10%) in diabetic rats compared to the other dose (25, 50 mg/kg) at the end of the study. The protective effect was further confirmed by histopathological examination of the liver.

CONCLUSION

PESA and α-amyrin acetate demonstrated remarkable antidiabetic activity in STZ-induced diabetic rats.

The effect of heparin on antigen-induced mucus hypersecretion in the nasal epithelium of sensitized rats

BACKGROUND

Heparin is a potential anti-inflammatory drug for allergic airway inflammation. To elucidate the effects of heparin on allergic inflammation, we examined the in vivo effects of heparin on antigen-induced mucus hypersecretion and infiltration of eosinophils and neutrophils in the nasal epithelium of sensitized rats.

METHODS

We induced hypertrophic and metaplastic changes of goblet cells in the nasal epithelium of ovalbumin (OVA)-sensitized rats by intranasal challenge with OVA. The effects of intranasal instillation with low molecular weight heparin (LMWH; 1-1000IU/0.1ml) on mucus production and eosinophil/neutrophil infiltration were examined.

RESULTS

Intranasal instillation with low-dose LMWH (1-10IU/0.1ml) at 30 minutes before OVA instillation stimulated OVA-induced mucus production in the nasal epithelium of sensitized rats, whereas treatment with 100IU/0.1ml LMWH showed no effect. Intranasal instillation with high-dose LMWH (1000IU/0.1ml) significantly inhibited OVA-induced mucus production. Intranasal instillation with LMWH (1-1000IU/0.1ml) dose-dependently inhibited eosinophil and neutrophil infiltration into the rat nasal mucosa.

CONCLUSIONS

These results indicate that heparin inhibits mucus hypersecretion and infiltration of eosinophils and neutrophils in allergic inflammation, though the inhibitory effect against mucus production is obtained in high-dose heparin. Intranasal instillation with high-dose heparin may provide a new therapeutic strategy for the treatment of nasal allergic inflammation.

An alternative pathway of imiquimod-induced psoriasis-like skin inflammation in the absence of interleukin-17 receptor a signaling

Topical application of imiquimod (IMQ) on the skin of mice induces inflammation with common features found in psoriatic skin. Recently, it was postulated that IL-17 has an important role both in psoriasis and in the IMQ model. To further investigate the impact of IL-17RA signaling in psoriasis, we generated IL-17 receptor A (IL-17RA)-deficient mice (IL-17RA(del)) and challenged these mice with IMQ. Interestingly, the disease was only partially reduced and delayed but not abolished when compared with controls. In the absence of IL-17RA, we found persisting signs of inflammation such as neutrophil and macrophage infiltration within the skin. Surprisingly, already in the naive state, the skin of IL-17RA(del) mice contained significantly elevated numbers of Th17- and IL-17-producing γδ T cells, assuming that IL-17RA signaling regulates the population size of Th17 and γδ T cells. Upon IMQ treatment of IL-17RA(del) mice, these cells secreted elevated amounts of tumor necrosis factor-α, IL-6, and IL-22, accompanied by increased levels of the chemokine CXCL2, suggesting an alternative pathway of neutrophil and macrophage skin infiltration. Hence, our findings have major implications in the potential long-term treatment of psoriasis by IL-17-targeting drugs.

Sphingosine 1-phosphate mediates hyperalgesia via a neutrophil-dependent mechanism

Novel classes of pain-relieving molecules are needed to fill the void between non-steroidal anti-inflammatory agents and narcotics. We have recently shown that intraplantar administration of sphingosine 1-phosphate (S1P) in rats causes peripheral sensitization and hyperalgesia through the S1P(1) receptor subtype (S1PR(1)): the mechanism(s) involved are largely unknown and were thus explored in the present study. Intraplantar injection of carrageenan in rats led to a time-dependent development of thermal hyperalgesia that was associated with pronounced edema and infiltration of neutrophils in paw tissues. Inhibition of 1) S1P formation with SK-I, a sphingosine kinase inhibitor, 2) S1P bioavailability with the S1P blocking antibody Sphingomab, LT1002 (but not its negative control, LT1017) or 3) S1P actions through S1PR(1) with the selective S1PR(1) antagonist, W146 (but not its inactive enantiomer, W140) blocked thermal hyperalgesia and infiltration of neutrophils. Taken together, these findings identify S1P as an important contributor to inflammatory pain acting through S1PR(1) to elicit hyperalgesia in a neutrophil-dependant manner. In addition and in further support, we demonstrate that the development of thermal hyperalgesia following intraplantar injection of S1P or SEW2871 (an S1PR(1) agonist) was also associated with neutrophilic infiltration in paw tissues as these events were attenuated by fucoidan, an inhibitor of neutrophilic infiltration. Importantly, FTY720, an FDA-approved S1P receptor modulator known to block S1P-S1PR(1) signaling, attenuated carrageenan-induced thermal hyperalgesia and associated neutrophil infiltration. Targeting the S1P/S1PR(1) axis opens a therapeutic strategy for the development of novel non-narcotic anti-hyperalgesic agents.

Toxicogenomic analysis of the particle dose- and size-response relationship of silica particles-induced toxicity in mice

This study investigated the relationship between particle size and toxicity of silica particles (SP) with diameters of 30, 70, and 300 nm, which is essential to the safe design and application of SP. Data obtained from histopathological examinations suggested that SP of these sizes can all induce acute inflammation in the liver. In vivo imaging showed that intravenously administrated SP are mainly present in the liver, spleen and intestinal tract. Interestingly, in gene expression analysis, the cellular response pathways activated in the liver are predominantly conserved independently of particle dose when the same size SP are administered or are conserved independently of particle size, surface area and particle number when nano- or submicro-sized SP are administered at their toxic doses. Meanwhile, integrated analysis of transcriptomics, previous metabonomics and conventional toxicological results support the view that SP can result in inflammatory and oxidative stress, generate mitochondrial dysfunction, and eventually cause hepatocyte necrosis by neutrophil-mediated liver injury.

The antinociceptive and anti-inflammatory effects of the crude extract of Jatropha isabellei in a rat gout model

ETHNOPHARMACOLOGICAL RELEVANCE

Jatropha isabellei Müll Arg. (Euphorbiaceae) is a medicinal plant that has been used in South American folk medicine for the treatment of arthritic diseases, particularly gout.

AIM OF THE STUDY

This study was designed to verify the antinociceptive, anti-inflammatory and hypouricemic potential of Jatropha isabellei.

MATERIALS AND METHODS

Rats were orally administered with the crude extract (100-300 mg/kg) or a fraction that is rich in alkaloids (0.15 mg/kg) of Jatropha isabellei. An intra-articular (i.a.) injection of 50 μl of monosodium urate (MSU) crystals (1.25mg/site) was used to generate the gout model to assess the effect of the treatment on nociception (thermal and mechanical hyperalgesia) and inflammation (oedema and neutrophil infiltration). The effect of Jatropha isabellei on the serum levels of uric acid was evaluated in a model of hyperuricaemia induced by the intraperitoneal injection of potassium oxonate (250 mg/kg). The side effects were analysed using an open-field test, gastric lesion assessment and by measuring the levels of the ALT and AST enzymes.

RESULTS

Our study demonstrated that the crude extract of Jatropha isabellei and a fraction rich in alkaloids were able to prevent the thermal hyperalgesia, mechanical allodynia, oedema and neutrophil infiltration induced by intra-articular MSU injection in rats. On the other hand, treatment with Jatropha isabellei did not alter the uric acid levels increased by potassium oxonate in the hyperuricaemia model. In addition, Jatropha isabellei did not induce gastric lesions or liver damage and did not alter spontaneous locomotor activity.

CONCLUSION

The crude extract of Jatropha isabellei and its fraction rich in alkaloid presents antinociceptive and anti-inflammatory effects in a rat gout model, similar to that observed after treatment with colchicine, supporting the traditional use of this plant in gouty patients.

Ligand-dependent actions of the vitamin D receptor are required for activation of TGF-β signaling during the inflammatory response to cutaneous injury

The vitamin D receptor (VDR) has both 1,25-dihydroxyvitamin D-dependent and -independent actions in the epidermis. Ligand-dependent actions of the VDR have been shown to promote keratinocyte differentiation and to regulate formation of the epidermal barrier. In contrast, the actions of the VDR that regulate postmorphogenic hair cycling do not require 1,25-dihydroxyvitamin D. The VDR also has immunomodulatory actions that are dependent on its ligand, 1,25-dihydroxyvitamin D. To determine whether the ligand-dependent or -independent actions of the VDR regulate the inflammatory response to cutaneous injury, studies were performed in control, VDR knockout, and vitamin D-deficient mice. These investigations demonstrate that absence of receptor or ligand impairs the dermal response to cutaneous injury. Although neutrophil recruitment is not affected, the absence of VDR signaling leads to defects in macrophage recruitment and granulation tissue formation. Studies performed to identify the molecular basis for this phenotype demonstrate that absence of the VDR, or its ligand, impairs TGF-β signaling in the dermis, characterized by decreased expression of monocyte chemotactic protein-1 and reduced phosphorylation of phosphorylated Smad-3 as well as attenuated phosphorylated Smad-3 phosphorylation in response to TGF-β in primary dermal fibroblasts lacking the VDR. Thus, these data demonstrate that the liganded VDR interacts with the TGF-β signaling pathway to promote the normal inflammatory response to cutaneous injury.

Ozone exaggerates nasal allergic inflammation

A double-blind randomised trail design was used to address the effect of ambient ozone on the nasal airways and to evaluate the effects of ozone on allergic mucosa. Ten grass pollen allergic rhinitics were exposed for 2 hours at rest on 2 separate occasions to 400 ppb ozone and filtered air respectively. The exposure to 400 ppb ozone and filtered air was performed prior to the grass pollen season and again during the season. Baseline nasal lavage in which histamine, eosinophil cationic protein (ECP), myeloperoxidase (MPO), total proteins, and albumin were measured and neutrophils, eosinophils and epithelial cells were counted, was made immediately prior to exposure (-120 min). After 2 h of exposure to ozone/filtered air repeated measurements were performed at 0, 30, 60, 120, 240, 360 minutes post exposure. Significant increases were observed when exposed to ozone versus filtered air during the pollen season for histamine (AUC1; p=0.05), MPO (AUC2; p=0.05), ECP (AUC2; p=0.008), total proteins (AUC, p=0.02; AUC1, p=0.007; AUC2, p=0.05), and albumin (AUC, p=0.007; AUC1, p=0.02; AUC2, p=0.005). There was also a significant increase in the total protein level (AUC, p=0.05; AUC1, p=0.02; AUC2 p=0.05) and albumin (AUC, p=0.03; AUC1, p=0.03; AUC2, p=0.04) after ozone exposure versus air out of season. Significant increase of the neutrophils (p=0.01 and p=0.007) in the nasal lavage fluid (NLF) at time points 0 min and 360 min respectively were observed, while eosinophils and epithelial cells significantly increased only at time point 360 min (p=0.02 and p=0.02 respectively) all of them after ozone exposure versus filtered air during the season. Neutrophils also significantly increased in the NLF at time point 0 min and 360 min (p=0.03 and p=0.01) while epithelial cells increased only at time point 360 min (p=0.01) after ozone exposure versus filtered air out of season. We can conclude that ozone induces neutrophil and eosinophil recruitment into the nose and this is accompanied by activation, as evidenced by release of MPO and ECP in NAL. Pre-existing allergic mucosal inflammation during the pollen season, exaggerates the response to ozone, particularly in relationship to the recruitment of eosinophils and neutrophils 6h following exposure.

Hawthorn leaves flavonoids decreases inflammation related to acute myocardial ischemia/reperfusion in anesthetized dogs

OBJECTIVE

To investigate the effects and mechanisms of hawthorn leaves flavonoids (HLF) on acute myocardial ischemia/reperfusion in anesthetized dogs.

METHODS

The acute ischemia models were prepared by ligating left anterior descending (LAD) artery for 60 min. Qualified 15 male dogs were randomly divided into 3 groups with 5 in each group: blank control (treated with normal saline 3 mL/kg) group, HLF low dosage (5 mg/kg) group and high dosage (10 mg/kg) group, with an once injection through a femoral vein 5 min before reperfusion. Epicardial electrocardiogram was adopted to measure the scope and degree of myocardial ischemia. Simultaneously, neutrophil infiltration in infarct (Inf) and remote site (RS) of myocardial tissue was measured by myeloperoxidase (MPO) activity assay. The serum interleukin-1 (IL-1) and tumor necrosis factorα (TNF-α) content were quantified by radioimmuno-assay. Furthermore, expression of G protein-coupled receptor kinase 2 (GRK2) and nuclear factor κB (NF-κB) in Inf and RS tissue were detected by Western blotting technique.

RESULTS

Ischemia and reperfusion increased the MPO activity and IL-1 and TNF-α content. HLF (10 and 5 mg/kg) could significantly decrease the degree and scope of myocardial ischemia; markedly inhibit the increase of MPO activity, and IL-1 and TNF-α content induced by myocardial ischemia/infarction. Furthermore, HLF increased GRK2 expression and inhibited NF-κB expression in Inf tissue.

CONCLUSION

HLF could improve the situation of acute myocardial ischemia and inhibit the inflammation in anesthetized dogs, which might be due to its increasing effect on the GRK2 and NF-κB expressions.

Anti-neutrophilic inflammatory secondary metabolites from the traditional Chinese medicine, Tiankuizi

Through bioassay-guided fractionation, thirteen compounds (1-13) were isolated from the dry root of Semiaquilegia adoxoides, known as Tiankuizi in traditional Chinese medicine (TCM). Among these, four benzoic acid derivatives (1, 2, 4, 5), one 4,6-dimethoxy-5-methyl-2H-pyran-2-one (10) and one 1,2,3-propanetriol (13) were found for the first time in S. adoxoides. This is the first record of compound 10 from a natural source. 4-Hydroxybenzoic acid (1) and 3,4-dihyroxybenzoic acid (2) showed selective inhibition against elastase release and superoxide anion generation, with IC50 values of 3.20 and 6.21 microg/mL, respectively. Compound 1 had 7-fold better activity than the positive control against elastase release induced by human neutrophils. Overall, our studies demonstrated Tiankuizi (S. adoxoides) as a potential TCM and isolates 1 and 2 as promising lead compounds for neutrophilic inflammatory diseases.

TEI-A00114: a new vitamin D3 analogue that inhibits neutrophil recruitment in an acute lung injury hamster model while showing reduced hypercalcemic activity

While searching for vitamin D(3) analogues which inhibit neutrophil recruitment in the lung without elevating plasma calcium level, we found that (5Z,7E)-(1S,3R)-20(R)-[(5E)-(2S)-2-hydroxy-2-methyl-cyclopentanone-5-ylidene]methyl-9,10-secopregna-5,7,10(19)-triene-1,3-diol (TEI-A00114) had the best efficacy and calcemic action. TEI-A00114 has a vitamin D receptor affinity 2.5-fold weaker and a vitamin D binding protein affinity 330.9-fold weaker than those of 1α,25(OH)(2)D(3). The estimated effective doses for 40% inhibition (ED(40)) via peroral and intratracheal administration are 7.6 and 0.4 μg/kg, respectively. TEI-A00114 was also tested by inhaled administration, and its ED(40) was calculated as 0.2 μg/kg. The estimated 40% inhibitory concentration (IC(40)) of TEI-A00114 on interleukin (IL)-8 production induced by lipopolysaccharide and on IL-1β in human whole blood cells in vitro were 9.8 × 10(-8) or 1.8 × 10(-9)M, respectively. These levels of TEI-A00114's activities are equal to those of 1α,25(OH)(2)D(3). On the other hand, the calcemic action of TEI-A00114, which was evaluated at day 14 after sequential peroral quaque die administration, was 89-fold weaker (molar ratio) than that of 1α,25(OH)(2)D(3). These results indicate that TEI-A00114 has a dissociated profile between inhibition of neutrophil recruitment in the lung and calcemic action, suggesting its suitability over 1α,25(OH)(2)D(3) as a candidate for the treatment of acute lung injury.

Nitroxides attenuate carrageenan-induced inflammation in rat paws by reducing neutrophil infiltration and the resulting myeloperoxidase-mediated damage

Tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) and other cyclic nitroxides have been shown to inhibit the chlorinating activity of myeloperoxidase (MPO) in vitro and in cells. To examine whether nitroxides inhibit MPO activity in vivo we selected acute carrageenan-induced inflammation on the rat paw as a model. Tempol and three more hydrophobic 4-substituted derivatives (4-azido, 4-benzenesulfonyl, and 4-(4-phenyl-1H-1,2,3-triazol-1-yl)) were synthesized, and their ability to inhibit the in vitro chlorinating activity of MPO and carrageenan-induced inflammation in rat paws was evaluated. All of the tested nitroxides inhibited the chlorinating activity of MPO in vitro with similar IC(50) values (between 1.5 and 1.8 μM). In vivo, the attenuation of carrageenan-induced inflammation showed some correlation with the lipophilicity of the nitroxide at early time points but the differences in the effects were small (<2-fold) compared with the differences in lipophilicity (>200-fold). No inhibition of MPO activity in vivo was evident because the levels of MPO activity in rat paws correlated with the levels of MPO protein. Likewise, paw edema, levels of nitrated and oxidized proteins, and levels of plasma exudation correlated with the levels of MPO protein in the paws of the animals that were untreated or treated with the nitroxides. The effects of the nitroxides in vivo were compared with those of 4-aminobenzoic hydrazide and of colchicine. Taken together, the results indicate that nitroxides attenuate carrageenan-induced inflammation mainly by reducing neutrophil migration and the resulting MPO-mediated damage. Accordingly, tempol was shown to inhibit rat neutrophil migration in vitro.

Oleic acid induces lung injury in mice through activation of the ERK pathway

Oleic acid (OA) can induce acute lung injury in experimental models. In the present work, we used intratracheal OA injection to show augmented oedema formation, cell migration and activation, lipid mediator, and cytokine productions in the bronchoalveolar fluids of Swiss Webster mice. We also demonstrated that OA-induced pulmonary injury is dependent on ERK1/2 activation, since U0126, an inhibitor of ERK1/2 phosphorylation, blocked neutrophil migration, oedema, and lipid body formation as well as IL-6, but not IL-1β production. Using a mice strain carrying a null mutation for the TLR4 receptor, we proved that increased inflammatory parameters after OA challenges were not due to the activation of the TLR4 receptor. With OA being a Na/K-ATPase inhibitor, we suggest the possible involvement of this enzyme as an OA target triggering lung inflammation.

Suppression of NF-κB reduces myocardial no-reflow

No-reflow phenomenon is a risk factor which severely compromises the benefits of coronary revascularization in patients with acute myocardial infarction. Inflammatory response, as an essential component of cardiac ischemia/reperfusion (I/R) injury, has been suggested to contribute to the myocardial no-reflow. Since nuclear factor kappa B (NF-κB) is a key mediator of inflammation, we reasoned that inhibition of NF-κB might reduce the extent of no-reflow. To test this hypothesis, the left circumflex coronary arteries of New Zealand white male rabbits were ligated for 1.5 h, followed by reperfusion for 1 h to induce I/R injury. Pretreatment of the rabbits with a specific NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), significantly attenuated neutrophil infiltration in the no-reflow area as well as the expansion of no-reflow. These beneficial effects were associated with a marked reduction in the serum levels of myocardial induced I/R tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and CXCL16. Consistently, simulative I/R culture of human umbilical vein endothelial cells (HUVECs) resulted in an increase of TNF-α, ICAM-1 and CXCL16, and all of these changes were significantly suppressed by pretreatment of the cells with PDTC or with siRNA-mediated p65 knockdown. Our data thus suggest that inhibition of NF-κB may reduce I/R-associated myocardial no-reflow through reduction of myocardial inflammation.

Changes in the relative inflammatory responses in sheep cells overexpressing of toll-like receptor 4 when stimulated with LPS

BACKGROUND

Many groups of Gram-negative bacteria cause diseases harmful to sheep. TLR4 is an important Toll-like receptor (TLR) which responds to common Gram-negative bacterial infections. Activation of TLR4 leads to the induction of inflammatory responses, which is a linkage between the innate and adaptive immune systems. A vector pTLR4-3S was constructed to overexpress TLR4 gene in sheep. In this study, effects of TLR4 overexpression on inflammation response under LPS stimulated were addressed in vivo and in vitro.

METHODOLOGY/PRINCIPAL FINDINGS

Sheep fetal fibroblasts were transfected with expression vector pTLR4-3S. Transgenic sheep were produced by microinjection of the constructed plasmids into fertilized eggs. Fetal fibroblasts, monocyte-macrophage and fibroblasts isolated from the transgenic sheep were stimulated by LPS. After that immunoactive factors (TNF-α, IL-10, IL-6, IL-8, IFN-γ), nitric oxide, phagocytize ability and adhesion were detected. Furthermore, transgenic sheep were intradermal injected of LPS in ear and observed pathological changes by HE strain. Overexpression of TLR4 gene was observed on transgenic cells and individuals. In vitro, TLR4 overexpression transgenic cells secreted Th1 and Th2 inducing cytokines with a strong LPS mediated inflammation response and promoting the secretion of nitric oxide, and then recovered to initial level. The phagocytosis index of monocyte/macrophage in transgenic sheep was higher than that of non-transgenic sheep (P<0.05). In vivo, tissue sections showed that transgenic individuals launched inflammation response more quickly.

CONCLUSIONS/SIGNIFICANCE

Overexpression of TLR4 in transgenic sheep enhanced the clearance of invaded microbe through secretion of cytokines, activation of macrophage, oxidation damage and infiltration of neutrophil.

Interleukin-37 reduces liver inflammatory injury via effects on hepatocytes and non-parenchymal cells

BACKGROUND AND AIM

The purpose of the present study was to determine the effects of interleukin-37 (IL-37) on liver cells and on liver inflammation induced by hepatic ischemia/reperfusion (I/R).

METHODS

Mice were subjected to I/R. Some mice received recombinant IL-37 (IL-37) at the time of reperfusion. Serum levels of alanine aminotransferase, and liver myeloperoxidase content were assessed. Serum and liver tumor necrosis factor-α (TNF-α), macrophage inflammatory protein-2 (MIP-2) and keratinocyte chemokine (KC) were also assessed. Hepatic reactive oxygen species (ROS) levels were assessed. For in vitro experiments, isolated hepatocytes and Kupffer cells were treated with IL-37 and inflammatory stimulants. Cytokine and chemokine production by these cells were assessed. Primary hepatocytes underwent induced cell injury and were treated with IL-37 concurrently. Hepatocyte cytotoxicity and Bcl-2 expression were determined. Isolated neutrophils were treated with TNF-α and IL-37 and neutrophil activation and respiratory burst were assessed.

RESULTS

IL-37 reduced hepatocyte injury and neutrophil accumulation in the liver after I/R. These effects were accompanied by reduced serum levels of TNF-α and MIP-2 and hepatic ROS levels. IL-37 significantly reduced MIP-2 and KC productions from lipopolysaccharide-stimulated hepatocytes and Kupffer cells. IL-37 significantly reduced cell death and increased Bcl-2 expression in hepatocytes. IL-37 significantly suppressed TNF-α-induced neutrophil activation.

CONCLUSIONS

IL-37 is protective against hepatic I/R injury. These effects are related to the ability of IL-37 to reduce proinflammatory cytokine and chemokine production by hepatocytes and Kupffer cells as well as having a direct protective effect on hepatocytes. In addition, IL-37 contributes to reduce liver injury through suppression of neutrophil activity.

Treatment of autoimmune inflammation by a TLR7 ligand regulating the innate immune system

The Toll-like receptors (TLR) have been advocated as attractive therapeutic targets because TLR signaling plays dual roles in initiating adaptive immune responses and perpetuating inflammation. Paradoxically, repeated stimulation of bone marrow mononuclear cells with a synthetic TLR7 ligand 9-benzyl-8-hydroxy-2-(2-methoxyethoxy) adenine (called 1V136) leads to subsequent TLR hyporesponsiveness. Further studies on the mechanism of action of this pharmacologic agent demonstrated that the TLR7 ligand treatment depressed dendritic cell activation, but did not directly affect T cell function. To verify this mechanism, we utilized experimental allergic encephalitis (EAE) as an in vivo T cell dependent autoimmune model. Drug treated SJL/J mice immunized with proteolipid protein (PLP)_139–151 peptide had attenuated disease severity, reduced accumulation of mononuclear cells in the central nervous system (CNS), and limited demyelination, without any apparent systemic toxicity. Splenic T cells from treated mice produced less cytokines upon antigenic rechallenge. In the spinal cords of 1V136-treated EAE mice, the expression of chemoattractants was also reduced, suggesting innate immune cell hyposensitization in the CNS. Indeed, systemic 1V136 did penetrate the CNS. These experiments indicated that repeated doses of a TLR7 ligand may desensitize dendritic cells in lymphoid organs, leading to diminished T cell responses. This treatment strategy might be a new modality to treat T cell mediated autoimmune diseases.

Molecular and cellular mechanisms of cigarette smoke-induced myocardial injury: prevention by vitamin C

BACKGROUND

Cardiovascular disease (CVD) remains one of the major killers in modern society. One strong risk factor of CVD is cigarette smoking that causes myocardial injury and leads to the genesis of pathological cardiovascular events. However, the exact toxic component(s) of cigarette smoke (CS) and its molecular and cellular mechanisms for causing myocardial injury leading to heart damage and its prevention are largely unknown.

METHODOLOGY/PRINCIPAL FINDINGS

Using a guinea pig model, here we show that chronic exposure to CS produces myocardial injury that is prevented by vitamin C. Male guinea pigs were fed either vitamin C-deficient (0.5 mg/day) or vitamin C-sufficient (15 mg/day) diet and subjected to CS exposure from 5 Kentucky Research cigarettes (3R4F)/day (6 days/week) in a smoke chamber up to 8 weeks. Pair-fed sham controls were subjected to air exposure instead of CS exposure under similar conditions. Myocardial injury was produced in CS-exposed marginal vitamin C-deficient guinea pigs as evidenced by release of cardiac Troponin-T and I in the serum, oxidative stress, inflammation, apoptosis, thrombosis and collagen deposition in the myocardium. Treatment of rat cardiomyocyte cells (H9c2) in vitro and guinea pigs in vivo with p-benzoquinone (p-BQ) in amounts derived from CS revealed that p-BQ was a major factor responsible for CS-induced myocardial damage. A moderately large dose of vitamin C (15 mg/day) prevented CS/p-BQ-induced myocardial injury. Population based studies indicated that plasma vitamin C levels of smokers without disease were significantly lower (p = 0,0000) than that of non-smokers. Vitamin C levels of CS-related cardiovascular patients were further lower (p = 0.0000) than that of smokers without disease.

CONCLUSIONS/SIGNIFICANCE

The results indicate that dietary supplementation of vitamin C may be a novel and simple therapy for the prevention of pathological cardiovascular events in habitual smokers.

Both lethal and edema toxins of Bacillus anthracis disrupt the human dendritic cell chemokine network

Bacillus anthracis, the agent of anthrax, produces two main virulence factors: a capsule and two toxins. Both lethal toxin (LT) and edema toxin (ET) paralyze the immune defense system. Here, we analyze the effects of LT and ET on the capacity of human monocyte-derived dendritic cells (MoDC) to produce proinflammatory chemokines. We show that both toxins disrupt proinflammatory chemokine production. LT has more pronounced effects than ET on CXCL8 production, which is correlated with impaired recruitment of neutrophils in vitro. Finally, we show that both toxins also differentially disrupt IL-12p70, IL-10, and TNF-α production. Taken together, these results demonstrate that both B. anthracis toxins alter MoDC functions and the activation of the innate immune system.

Arvelexin inhibits colonic inflammation by suppression of NF-κB activation in dextran sulfate sodium-induced mice and TNF-α-induced colonic epithelial cells

Recently, we reported the anti-inflammatory effects of arvelexin isolated from Brassica rapa in macrophages. In the present study, the effects of arvelexin were investigated in a dextran sulfate sodium (DSS)-induced colitis mouse model and in a cellular model. In the DSS-induced colitis model, arvelexin significantly reduced the severity of colitis, as assessed by disease activity, colonic damage, neutrophil infiltration, and levels of colonic iNOS. Moreover, arvelexin inhibited the expressions of IL-8, IP-10, ICAM-1, and VCAM-1 in HT-29 colonic epithelial cells. Arvelexin also inhibited the TNF-α-induced adhesion of U937 monocytic cells to HT-29 cells. Furthermore, arvelexin reduced p65 NF-κB subunit translocation to the nucleus and IκBα degradation in the colonic tissues and in TNF-α-induced HT-29 cells. These results demonstrate that the ameliorative effects of arvelexin on colonic injury are mainly related to its ability to inhibit the inflammatory responses via NF-κB inactivation, and support its possible therapeutic role in colitis.

Minocycline inhibits alkali burn-induced corneal neovascularization in mice

The purpose of this study was to investigate the effects of minocycline on alkali burn-induced corneal neovascularization (CNV). A total of 105 mice treated with alkali burns were randomly divided into three groups to receive intraperitoneal injections of either phosphate buffered saline (PBS) or minocycline twice a day (60 mg/kg or 30 mg/kg) for 14 consecutive days. The area of CNV and corneal epithelial defects was measured on day 4, 7, 10, and14 after alkali burns. On day 14, a histopathological examination was performed to assess morphological change and the infiltration of polymorphonuclear neutrophils (PMNs). The mRNA expression levels of vascular endothelial growth factor (VEGF) and its receptors (VEGFRs), basic fibroblast growth factor (bFGF), matrix metalloproteinases (MMPs), interleukin-1α, 1β, 6 (IL-1α, IL-1β, IL-6) were analyzed using real-time quantitative polymerase chain reaction. The expression of MMP-2 and MMP-9 proteins was determined by gelatin zymography. In addition, enzyme-linked immunosorbent assay was used to analyze the protein levels of VEGFR1, VEGFR2, IL-1β and IL-6. Minocycline at a dose of 60 mg/kg or 30 mg/kg significantly enhanced the recovery of the corneal epithelial defects more than PBS did. There were significant decreases of corneal neovascularization in the group of high-dosage minocycline compared with the control group at all checkpoints. On day 14, the infiltrated PMNs was reduced, and the mRNA expression of VEGFR1, VEGFR2, bFGF, IL-1β, IL-6, MMP-2, MMP-9, -13 as well as the protein expression of VEGFR2, MMP-2, -9, IL-1β, IL-6 in the corneas were down-regulated with the use of 60 mg/kg minocycline twice a day. Our results showed that the intraperitoneal injection of minocycline (60 mg/kg b.i.d.) can significantly inhibit alkali burn-induced corneal neovascularization in mice, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors, inflammatory cytokines and MMPs.

[Characteristic of early mucosal immune response in mice during intravaginal infection caused by Chlamydia muridarum]

AIM

Comparison of features of recruitment to infection focus of cells mediating early immune reactions in intravaginally infected mice that had previously received or not received covinan (progesterone analogue).

MATERIALS AND METHODS

A/Sn and BALB/c line mice were used in the study. C. muridarum strain Nigg infection was carried out intravaginally or intraperitoneally. For synchronization of sexual cycle a group of mice received subcutaneously a synthetic analogue of progesterone--proligeston (covinan) at a single dose of 33 mg/kg. Acute urogenital infection was evaluated by culture method. Quantitative determination of C. muridarum DNA (including study of persistence) was carried out by real time PCR. Subpopulation structure of cell population of peritoneal and vaginal lavage was evaluated by flow cytofluorometry.

RESULTS

Intravaginal infection of mice that had not received covinan resulted in a pronounced recruitment of cells into vaginal cavity at 24 hours after the infection. Influx of neutrophils, dendritic cells and T-lymphocytes was especially pronounced. Prior administration of covinan practically nullified cell recruitment to infection focus though partial preservation of subpopulations of activated dendritic cells and CD8+ T-cells was observed.

CONCLUSION

In mice with artificially induced by progesterone sensitivity to chlamydias the ability of recruitment to the infection focus of cells that mediate early immune reactions is reduced, that gives evidence on the importance of these reactions for infection outcome.

Neuroprotection of tanshinone IIA against cerebral ischemia/reperfusion injury through inhibition of macrophage migration inhibitory factor in rats

Background

Ischemia/reperfusion (I/R) injury is associated with systemic inflammatory response. Macrophage migration inhibitory factor (MIF) has been implicated in many inflammatory processes. Tanshinone IIA (TSA) is one of the active ingredients in danshen, which derived from the dried root or rhizome of Salviae miltiorrhizae Bge. Recent studies have demonstrated that TSA has protective effects against focal cerebral I/R injury. However, little is known about the underlying mechanisms. Here we put forward the hypothesis that TSA acts through inhibition of MIF expression during focal cerebral I/R injury in rats.

Methodology/Principal Findings

Rats were subjected to middle cerebral artery occlusion (MCAO) for 2 hours. This was followed by reperfusion. We measured neurological deficits, brain water content, and infarct volume, and found that neurological dysfunction, brain edema, and brain infarction were significantly attenuated by TSA 6 hours after reperfusion. We also measured myeloperoxidase (MPO) activity at 6 and 24 hours, and found that neutrophil infiltration was significantly higher in the vehicle+I/R group than in the TSA+I/R group. ELISA demonstrated that TSA could inhibit MIF expression and the release of TNF-α and IL-6 induced by I/R injury. Western blot analysis and immunofluorescence staining showed that MIF expression was significantly lower in the TSA+I/R group than in the vehicle+I/R group. MIF was found almost all located in neurons and hardly any located in astrocytes in the cerebral cortex. Western blot analysis and EMSA demonstrated that NF-κB expression and activity were significantly increased in the vehicle+I/R group. However, these changes were attenuated by TSA.

Conclusion/Significance

Our results suggest that TSA helps alleviate the proinflammatory responses associated with I/R-induced injury and that this neuroprotective effect may occur through down-regulation of MIF expression in neurons.

Methothrexate attenuates early neutrophil infiltration and the associated lipid peroxidation in the injured spinal cord but does not induce neurotoxicity in the uninjured spinal cord in rats

BACKGROUND

The goal of most acute therapies for spinal cord injury (SCI) in humans include attenuation of the early inflammatory response and may limit the extent of tissue injury and the consequent disability.

OBJECTIVE

The purpose of this study was to investigate the early effects of methothrexate (MTX) treatment on myeloperoxidase (MPO) activity, malondialdehyde (MDA) level, and ultrastructural findings in the injured and uninjured spinal cords of rats. The effects of MTX treatment were also compared with methylprednisolone sodium succinate (MPSS) treatment.

METHODS

Wistar rats were divided into seven groups: control; trauma alone (50 g/cm weight drop trauma); SCI + MPSS (30 mg/kg); SCI + low-dose (0.5 mg/kg) MTX (LDMTX); SCI + higher-dose (1 mg/kg) MTX (HDMTX); non-trauma + LDMTX; non-trauma + HDMTX.

RESULTS

Administration of MTX and MPSS treatments significantly decreased MPO activity (p < 0.05) and MDA level (p < 0.05) in the first 24 h. The MTX treatments, particularly HDMTX, were more effective than MPSS in reducing MPO activity, and MTX treatments were also more effective than MPSS in reducing MDA level (p < 0.05). The MTX treatment was more protective on large- and medium-diameter myelinated axons in minimizing ultrastructural changes in the spinal-cord-injured rats, but did not induce neurotoxicity in normal spinal cord.

CONCLUSION

The results of this study indicate that MTX treatment has a beneficial effect by reducing early neutrophil infiltration and the associated lipid peroxidation, and has significantly protective effects on the injured spinal cord tissue in the first 24 h after SCI. Given the anti-inflammatory properties of MTX, a single dose of MTX a week is used for non-neoplastic disease in humans, and MTX may have a beneficial role in the immediate management of acute SCI.

α1-Acid glycoprotein decreases neutrophil migration and increases susceptibility to sepsis in diabetic mice

The mechanisms underlying immune deficiency in diabetes are largely unknown. In the present study, we demonstrate that diabetic mice are highly susceptible to polymicrobial sepsis due to reduction in rolling, adhesion, and migration of leukocytes to the focus of infection. In addition, after sepsis induction, CXCR2 was strongly downregulated in neutrophils from diabetic mice compared with nondiabetic mice. Furthermore, CXCR2 downregulation was associated with increased G-protein-coupled receptor kinase 2 (GRK2) expression in these cells. Different from nondiabetic mice, diabetic animals submitted to mild sepsis displayed a significant augment in α1-acid glycoprotein (AGP) hepatic mRNA expression and serum protein levels. Administration of AGP in nondiabetic mice subjected to mild sepsis inhibited the neutrophil migration to the focus of infection, as well as induced l-selectin shedding and rise in CD11b of blood neutrophils. Insulin treatment of diabetic mice reduced mortality rate, prevented the failure of neutrophil migration, impaired GRK2-mediated CXCR2 downregulation, and decreased the generation of AGP. Finally, administration of AGP abolished the effect of insulin treatment in diabetic mice. Together, these data suggest that AGP may be involved in reduction of neutrophil migration and increased susceptibility to sepsis in diabetic mice.

Tanshinone IIA attenuates the inflammatory response and apoptosis after traumatic injury of the spinal cord in adult rats

BACKGROUND

Spinal cord injury (SCI), including immediate mechanical injury and secondary injury, is associated with the inflammatory response, apoptosis and oxidative stress in response to traumatic injury. Tanshinone IIA (TIIA) is one of the major extracts obtained from Salvia miltiorrhiza BUNGE, which has anti-inflammatory and anti-apoptotic effects on many diseases. However, little is known about the effects of TIIA treatment on SCI. Therefore, the aim of the present study is to evaluate the pharmacological action of TIIA on secondary damage and the underlying mechanisms of experimental SCI in rats.

METHODOLOGY/PRINCIPAL FINDINGS

SCI was generated using a weight drop device on the dorsal spinal cord via a two-level T9-T11 laminectomy. SCI in rats resulted in severe trauma, characterized by locomotor disturbance, edema, neutrophil infiltration, the production of astrocytes and inflammatory mediators, apoptosis and oxidative stress. TIIA treatment (20 mg/kg, i.p.) after SCI induced significant effects: (1) improved motor function (Basso, Beattie and Bresnahan scores), (2) reduced the degree of tissue injury (histological score), neutrophil infiltration (myeloperoxidase activity) and the expression of astrocytes, (3) inhibited the activation of SCI-related pathways, such as NF-κB and MAPK signaling pathways, (4) decreased the production of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) and iNOS, (5) reduced apoptosis (TUNEL staining, and Bcl-2 and caspase-3 expression) and (6) reversed the redox state imbalance.

CONCLUSIONS/SIGNIFICANCE

The results clearly show that TIIA has a prominent protective effect against SCI through inhibiting the inflammatory response and apoptosis in the spinal cord tissue after SCI.

Evaluation of the effects of a high dose of erythropoietin-beta on early endotoxemia using a rat model

BACKGROUND

Endotoxins can cause serious organ damage and death by triggering the secretion of pro-inflammatory cytokines such as TNF-alpha, IL-6 and IL-1beta in bacterial infections.

OBJECTIVES

The goal of this study was to evaluate the effects of a high dose (3000 U/kg) of erythropoietin-beta (EPO) on inflammatory cytokine levels, renal function and histological changes during the early period of Lipopolysaccharide (LPS)-induced endotoxemia using a rat model.

MATERIAL AND METHODS

Male Sprague Dawley (350-400 g) rats were randomized into 3 groups: Control group (n = 7); LPS group (received 20 mcg/kg LPS through intraperitoneal (i.p.) injection (n = 7); LPS+EPO group (received 3000 U/kg, ip 30 minutes before LPS administration (n = 7). Four hours after the administration of LPS, kidney tissue and serum samples were collected. Kidney function parameters, TNF-alpha, IL-6, IL-1beta, C reactive protein (CRP) and complete blood counts (CBC) were measured. The severity of renal tubular injury and caspase-9 immunoreactive cells was expressed as a percentage.

RESULTS

Serum levels of urea, creatinine, TNF-alpha, IL-6 and IL-1beta were significantly increased in the LPS group (p < 0.0001 - p = 0.04) and were lower in LPS+EPO group (p < 0.0001, p = 0.01, p = 0.02, p = 01 and p < 0.0001, respectively). Pretreatment with EPO significantly increased platelet counts (p = 0.00) and decreased white blood cell counts (p = 0.02). The renal tubular injury percentage was significantly higher in the LPS group than in the control and LPS+EPO groups (p = 0.002, p = 0.003, and p = 0.005, respectively) and caspase-9 expression was lower in the LPS+EPO and control groups than in the LPS group.

CONCLUSIONS

EPO might have renoprotective effects against the inflammatory process and cell apoptosis during endotoxemia.

Modulation of experimental herpes encephalitis-associated neurotoxicity through sulforaphane treatment

Reactive oxygen species (ROS) produced by brain-infiltrating macrophages and neutrophils, as well as resident microglia, are pivotal to pathogen clearance during viral brain infection. However, unchecked free radical generation is also responsible for damage to and cytotoxicity of critical host tissue bystander to primary infection. These unwanted effects of excessive ROS are combated by local cellular production of antioxidant enzymes, including heme oxygenase-1 (HO-1) and glutathione peroxidase 1 (Gpx1). In this study, we showed that experimental murine herpes encephalitis triggered robust ROS production, as well as an opposing upregulation of the antioxidants HO-1 and Gpx1. This antioxidant response was insufficient to prevent tissue damage, neurotoxicity, and mortality associated with viral brain infection. Previous studies corroborate our data supporting astrocytes as the major antioxidant producer in brain cell cultures exposed to HSV-1 stimulated microglia. We hypothesized that stimulating opposing antioxidative responses in astrocytes, as well as neurons, would mitigate the effects of ROS-mediated neurotoxicity both in vitro and during viral brain infection in vivo. Here, we demonstrate that the addition of sulforaphane, a potent stimulator of antioxidant responses, enhanced HO-1 and Gpx1 expression in astrocytes through the activation of nuclear factor-E2-related factor 2 (Nrf2). Additionally, sulforaphane treatment was found to be effective in reducing neurotoxicity associated with HSV-stimulated microglial ROS production. Finally, intraperitoneal injections of sulforaphane into mice during active HSV infection reduced neuroinflammation via a decrease in brain-infiltrating leukocytes, macrophage- and neutrophil-produced ROS, and MHCII-positive, activated microglia. These data support a key role for astrocyte-produced antioxidants in modulating oxidative stress and neuronal damage in response to viral infection.

Neutrophils Promote Mycobacterial Trehalose Dimycolate-Induced Lung Inflammation via the Mincle Pathway

Trehalose 6,6'-dimycolate (TDM), a cord factor of Mycobacterium tuberculosis (Mtb), is an important regulator of immune responses during Mtb infections. Macrophages recognize TDM through the Mincle receptor and initiate TDM-induced inflammatory responses, leading to lung granuloma formation. Although various immune cells are recruited to lung granulomas, the roles of other immune cells, especially during the initial process of TDM-induced inflammation, are not clear. In this study, Mincle signaling on neutrophils played an important role in TDM-induced lung inflammation by promoting adhesion and innate immune responses. Neutrophils were recruited during the early stage of lung inflammation following TDM-induced granuloma formation. Mincle expression on neutrophils was required for infiltration of TDM-challenged sites in a granuloma model induced by TDM-coated-beads. TDM-induced Mincle signaling on neutrophils increased cell adherence by enhancing F-actin polymerization and CD11b/CD18 surface expression. The TDM-induced effects were dependent on Src, Syk, and MAPK/ERK kinases (MEK). Moreover, coactivation of the Mincle and TLR2 pathways by TDM and Pam3CSK4 treatment synergistically induced CD11b/CD18 surface expression, reactive oxygen species, and TNFα production by neutrophils. These synergistically-enhanced immune responses correlated with the degree of Mincle expression on neutrophil surfaces. The physiological relevance of the Mincle-mediated anti-TDM immune response was confirmed by defective immune responses in Mincle⁻/⁻ mice upon aerosol infections with Mtb. Mincle-mutant mice had higher inflammation levels and mycobacterial loads than WT mice. Neutrophil depletion with anti-Ly6G antibody caused a reduction in IL-6 and monocyte chemotactic protein-1 expression upon TDM treatment, and reduced levels of immune cell recruitment during the initial stage of infection. These findings suggest a new role of Mincle signaling on neutrophils during anti-mycobacterial responses.

Effect of dietary advanced glycation end products on mouse liver

The exact pathophysiology of non-alcoholic steatohepatitis (NASH) is not known. Previous studies suggest that dietary advanced glycation end products (AGEs) can cause oxidative stress in liver. We aim to study the effects of dietary AGEs on liver health and their possible role in the pathogenesis of NASH.

METHODS

Two groups of mice were fed the same diet except the AGE content varied. One group was fed a high AGE diet and the second group was fed a regular AGE diet. Liver histology, alanine aminotransferase, aspartate aminotransferase, fasting glucose, fasting insulin, insulin resistance and glucose tolerance were assessed.

RESULTS

Histology revealed that neutrophil infiltration occurred in the livers of the high AGE group at week 26; steatosis did not accompany liver inflammation. At week 39 livers from both groups exhibited macro- or micro-steatosis, yet no inflammation was detected. Higher insulin levels were detected in the regular AGE group at week 26 (P = 0.034), compared to the high AGE group. At week 39, the regular AGE group showed higher levels of alanine aminotransferase (P<0.01) and aspartate aminotransferase (P = 0.02) than those of the high AGE group.

CONCLUSIONS

We demonstrate that a high AGE diet can cause liver inflammation in the absence of steatosis. Our results show that dietary AGEs could play a role in initiating liver inflammation contributing to the disease progression of NASH. Our observation that the inflammation caused by high AGE alone did not persist suggests interesting future directions to investigate how AGEs contribute to pro-oxidative and anti-oxidative pathways in the liver.

Protective effect of Danning tablet on acute livery injury with cholestasis induced by α-naphthylisothiocyanate in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Danning tablet, as a composite prescription of traditional Chinese medicine, has been used clinically to relieve liver and gallbladder diseases in China. However, the mechanisms involved are still unclear.

AIM OF THE STUDY

The present investigation was designed to assess the effects and possible mechanisms of Danning tablet on α-naphthylisothiocyanate (ANIT)-induced liver injury with cholestasis.

MATERIALS AND METHODS

Danning tablet (3, 1.5 or 0.75g/kg body weight/day) was intragastrically (i.g.) given to experimental rats for seven days before they were treated with ANIT (60mg/kg daily via i.g.) which caused liver injury. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltranspeptidase (γ-GTP), total bilirubin (T-Bil), direct bilirubin (D-Bil), total bile acid (TBA) and bile flow were measured to evaluate the protective effect of Danning tablet at 48h after ANIT treatment. Furthermore, protective mechanisms of Danning tablet against ANIT-induced liver injury were elucidated by assays of liver enzyme activities and component contents including myeloperoxidase (MPO), superoxide dismutase (SOD), glutathione peroxidase (Gpx), catalase (CAT) and glutathione S-transferase (GST), as well as liver lipid peroxide (LPO) and glutathione (GSH). The biochemical observations were supplemented by histopathological examination. Phytochemical analysis of Danning tablet was performed by UPLC-MASS.

RESULTS

Obtained results demonstrated that high dose (3g/kg) of Danning tablet significantly prevented ANIT-induced changes in bile flow (P<0.01), and serum levels of ALT, AST, ALP, γ-GTP, T-Bil, D-Bil (P<0.01) and TBA (P<0.05). In addition, ANIT-induced increases in hepatic MPO, GST activities and GSH, LPO contents were significantly (P<0.01) reduced, while SOD, Gpx, CAT activities in the liver tissue which were suppressed by ANIT were significantly (P<0.01) elevated in the groups pretreated with Danning tablet at the dose of 3g/kg B.W. Histopathology of the liver tissue showed that pathological injuries were relieved after Danning tablet (3g/kg) pretreatment. The results also showed that medium dose (1.5g/kg) of Danning tablet exhibited partially protective effect on ANIT-induced liver injury with cholestasis by reversing part of biochemical parameters and histopathological changes. Low dose (0.75g/kg) of Danning tablet did not show any protective effect on ANIT-induced liver injury with cholestasis. Phytochemical analyses revealed the presence of anthraquinones, flavonoids and stilbene in the Danning tablet.

CONCLUSION

These findings indicate that Danning tablet exerts a dose-dependently protective effect on ANIT-induced liver injury with cholestasis in rats, and the possible mechanism of this activity is likely due to its attenuation of oxidative stress in the liver tissue and neutrophil infiltration.

Decreased leukocyte recruitment by inorganic nitrate and nitrite in microvascular inflammation and NSAID-induced intestinal injury

Nitric oxide (NO) generated by vascular NO synthases can exert anti-inflammatory effects, partly through its ability to decrease leukocyte recruitment. Inorganic nitrate and nitrite, from endogenous or dietary sources, have emerged as alternative substrates for NO formation in mammals. Bioactivation of nitrate is believed to require initial reduction to nitrite by oral commensal bacteria. Here we investigated the effects of inorganic nitrate and nitrite on leukocyte recruitment in microvascular inflammation and in NSAID-induced small-intestinal injury. We show that leukocyte emigration in response to the proinflammatory chemokine MIP-2 is reduced by 70% after 7 days of dietary nitrate supplementation as well as by acute intravenous nitrite administration. Nitrite also reduced leukocyte adhesion to a similar extent and this effect was inhibited by the soluble guanylyl cyclase inhibitor ODQ, whereas the effect on emigrated leukocytes was not altered by this treatment. Further studies in TNF-α-stimulated endothelial cells revealed that nitrite dose-dependently reduced the expression of ICAM-1. In rats and mice subjected to a challenge with diclofenac, dietary nitrate prevented the increase in myeloperoxidase and P-selectin levels in small-intestinal tissue. Antiseptic mouthwash, which eliminates oral nitrate reduction, markedly blunted the protective effect of dietary nitrate on P-selectin levels. Despite attenuation of the acute immune response, the overall ability to clear an infection with Staphylococcus aureus was not suppressed by dietary nitrate as revealed by noninvasive IVIS imaging. We conclude that dietary nitrate markedly reduces leukocyte recruitment to inflammation in a process involving attenuation of P-selectin and ICAM-1 upregulation. Bioactivation of dietary nitrate requires intermediate formation of nitrite by oral nitrate-reducing bacteria and then probably further reduction to NO and other bioactive nitrogen oxides in the tissues.

2-methoxycinnamaldehyde from Cinnamomum cassia reduces rat myocardial ischemia and reperfusion injury in vivo due to HO-1 induction

ETHNOPHARMACOLOGICAL RELEVANCE

Cinnamomum cassia Blume has been used as a traditional Chinese herbal medicine for alleviation of fever, inflammation, chronic bronchitis, and to improve blood circulation.

AIM OF THE STUDY

We addressed whether 2-methoxycinnamaldehyde (2-MCA), one of active ingredients of Cinnamomum cassia, reduces vascular cell adhesion molecule-1 (VCAM-1) expression in tumor necrosis factor-alpha (TNF-α)-activated endothelial cells and protects ischemia/reperfusion (I/R)-injury due to heme oxygenase (HO)-1 induction.

MATERIALS AND METHODS

Adult male rats were subjected to 30 min of ischemia by occlusion of the left anterior descending coronary artery followed by 24h of reperfusion. Rats were randomized to receive vehicle or 2-MCA (i.v.) 10 min before reperfusion.

RESULTS

Administration of 2-MCA significantly improved I/R-induced myocardial dysfunction by increasing the values of the first derivative (±dp/dt) of left ventricular pressure and decreased infarct size. In addition, 2-MCA reduced the expression of high mobility group box 1 (HMGB1), an activator of the inflammatory cascade when released into the extracellular space, and VCAM-1 in I/R myocardium along with increase of HO-1 induction. The reduced injury was accompanied by significantly reduction of neutrophils infiltration and increased SOD activity in ischemic tissues and reduced serum level of cardiac troponin I (cTnI). Furthermore, 2-MCA significantly increased HO-1 induction by translocation of Nrf-2 from cytosol to nucleus in endothelial cells. Inhibition of VCAM-1 expression by 2-MCA was reversed both by SnPPIX, a HO-1 inhibitor and siHO-1 RNA trasfection in TNF-α-activated cells. In addition, 2-MCA significantly inhibited NF-κB luciferase activity in TNF-α-activated endothelial cells. As expected, 2-MCA significantly inhibited monocyte (U937) adhesion to endothelial cells.

CONCLUSION

We concluded that 2-MCA protects of myocardial I/R-injury due to antioxidant and anti-inflammatory action possibly by HO-1 induction which can be explained why Cinnamomum cassia has been used in inflammatory disorders.

Tumor necrosis factor-α-mediated threonine 435 phosphorylation of p65 nuclear factor-κB subunit in endothelial cells induces vasogenic edema and neutrophil infiltration in the rat piriform cortex following status epilepticus

BACKGROUND

Status epilepticus (SE) induces severe vasogenic edema in the piriform cortex (PC) accompanied by neuronal and astroglial damages. To elucidate the mechanism of SE-induced vasogenic edema, we investigated the roles of tumor necrosis factor (TNF)-α in blood-brain barrier (BBB) disruption during vasogenic edema and its related events in rat epilepsy models provoked by pilocarpine-induced SE.

METHODS

SE was induced by pilocarpine in rats that were intracerebroventricularly infused with saline-, and soluble TNF p55 receptor (sTNFp55R) prior to SE induction. Thereafter, we performed Fluoro-Jade B staining and immunohistochemical studies for TNF-α and NF-κB subunits.

RESULTS

Following SE, most activated microglia showed strong TNF-α immunoreactivity. In addition, TNF p75 receptor expression was detected in endothelial cells as well as astrocytes. In addition, only p65-Thr435 phosphorylation was increased in endothelial cells accompanied by SMI-71 expression (an endothelial barrier antigen). Neutralization of TNF-α by soluble TNF p55 receptor (sTNFp55R) infusion attenuated SE-induced vasogenic edema and neuronal damages via inhibition of p65-Thr435 phosphorylation in endothelial cells. Furthermore, sTNFp55R infusion reduced SE-induced neutrophil infiltration in the PC.

CONCLUSION

These findings suggest that impairments of endothelial cell functions via TNF-α-mediated p65-Thr 485 NF-κB phosphorylation may be involved in SE-induced vasogenic edema. Subsequently, vasogenic edema results in extensive neutrophil infiltration and neuronal-astroglial loss.

IL-22 is required for imiquimod-induced psoriasiform skin inflammation in mice

Psoriasis is a common chronic autoimmune skin disease of unknown cause that involves dysregulated interplay between immune cells and keratinocytes. IL-22 is a cytokine produced by the TH1, TH17, and TH22 subsets that are functionally implicated in the psoriatic pathology. We assessed the role of IL-22 in a mouse model where psoriasiform skin inflammation is triggered by topical application of the TLR7/8 agonist imiquimod. At the macroscopic level, scaly skin lesions induced by daily applications of imiquimod in wild-type mice were almost totally absent in IL-22-deficient mice or in mice treated with a blocking anti-IL-22 Ab. At the microscopic level, IL-22-deficient mice showed a dramatic decrease in the development of pustules and a partial decrease in acanthosis. At the molecular level, the absence or inhibition of IL-22 strongly decreased the expression of chemotactic factors such as CCL3 and CXCL3 and of biomarkers such as S100A8, S100A7, and keratin 14, which reflect the antimicrobial and hyperproliferative responses of keratinocytes. IL-22 also played a major role in neutrophil infiltration after imiquimod treatment. IL-23 was required for IL-22 production, and γδ TCR lymphocytes represented the major source of IL-22 in lymph nodes from imiquimod-treated mice. However, T cells were not absolutely required for IL-22 production because imiquimod-induced IL-22 expression in the skin is still preserved in Rag2(-/-) mice. Taken together, our data show that IL-22 is required for psoriasis-like lesions in the mouse imiquimod model and is produced by both T cells and innate immune cells.

Influence of season and location on pulmonary response to California's San Joaquin Valley airborne particulate matter

Season and location have documented impacts on particulate matter (PM)-induced morbidity and mortality. Seasonal and regional influences on the physical and chemical properties of PM₂.₅ (also known as fine/ultrafine PM) contribute to differences in exposure burden and adverse respiratory health outcomes experienced in California's San Joaquin Valley (SJV), which ranks among the worst in the nation for PM pollution. Current regulations are driven by the association between mass concentrations and adverse health outcomes. However, this association is difficult to reproduce in toxicological studies and suggests a role for other parameters, such as chemical composition, involved in PM-induced adverse pulmonary health effects. Pulmonary toxicity of summer/winter and rural/urban SJV PM was evaluated given the unique geography, metereology and sources of the region. Healthy juvenile male mice inhaled summer/winter and urban/rural concentrated ambient PM (CAP) or ambient PM for 6 h/d for 10 d, and pulmonary inflammatory responses were measured 48 h postexposure. Exposure concentrations ranged from 10 to 20 μg/m³ for ambient air control mice and from 86 to 284 μg/m³. Mice exposed to rural but not urban CAP, displayed significant neutrophil influx that was more than 50-fold greater than control levels, which ranged from 21 to 60 neutrophils/ml for all experiments. Pulmonary neutrophilic inflammation was measured despite lower CAP concentrations in the rural compared to the urban location and in the absence of cytotoxicity, oxidative stress, or elevations in cytokine and chemokines expression. Further, the inflammatory responses induced by rural winter CAP were associated with the highest levels of organic carbon (OC) and nitrates (NO₃⁻). Evidence indicates that regional/seasonal influences on PM chemical composition rather than PM mass may be associated with increased PM-induced adverse health effects.

Early growth response factor-1 limits biliary fibrosis in a model of xenobiotic-induced cholestasis in mice

Hepatic expression of the transcription factor early growth response-1 (Egr-1) is increased in livers of patients with cholestatic liver disease. Bile acid induction of inflammatory genes in hepatocytes is Egr-1 dependent, and Egr-1 expression is increased in livers of mice after bile duct ligation. Of importance, Egr-1 deficiency reduces liver inflammation and injury in that model. However, it is not known whether Egr-1 promotes inflammation in other models of cholestasis. We tested the hypothesis that Egr-1 contributes to liver inflammation in mice exposed chronically to the bile duct epithelial cell (BDEC) toxicant alpha-naphthylisothiocyanate (ANIT). Egr-1-knockout (Egr-1(-/-)) mice and wild-type mice were fed a diet containing 0.025% ANIT for 2 weeks. Expression of Egr-1 mRNA and protein was significantly increased in livers of mice fed ANIT diet. Egr-1 deficiency did not significantly affect ANIT diet-induced hepatocellular injury, inflammatory gene induction, BDEC hyperplasia, or hepatic neutrophil accumulation. In contrast, the deposition of Type 1 collagen was significantly increased in livers of Egr-1(-/-) mice fed ANIT diet compared with wild-type mice fed ANIT diet. Interestingly, this increase in liver fibrosis occurred in association with elevated expression of the β6 integrin (Itgb6) gene, suggesting the potential for increased local activation of transforming growth factor beta. Taken together, the results indicate that Egr-1 does not contribute to liver injury or inflammation in mice fed a diet containing ANIT. Rather, these studies indicate that Egr-1 deficiency worsens liver fibrosis in conjunction with enhanced expression of the profibrogenic Itgb6 gene.

1α,25-Dihydroxyvitamin D₃ inhibits neutrophil recruitment in hamster model of acute lung injury

The chemokine interleukin-8 (IL-8) is involved in the pathogenesis of acute lung injury (ALI). Although several studies have reported that 1α,25-dihydroxyvitamin D(3) (1α,25(OH)(2)D(3)) suppresses IL-8 production in vitro and in vivo, 1α,25(OH)(2)D(3) has not been demonstrated to be effective in an animal model of ALI. Here, we determined its effects of 1α,25(OH)(2)D(3) in a hamster model where ALI was induced by lipopolysaccharide (LPS) inhalation. 1α,25(OH)(2)D(3) inhibited neutrophil recruitment in the lung by approximately 40% without increasing plasma calcium concentration, while it did not inhibit monocyte recruitment. Our findings show that vitamin D(3) analogues may be suitable as novel anti-inflammatory agents for ALI.

Enhanced Th17-cell responses render CCR2-deficient mice more susceptible for autoimmune arthritis

CCR2 is considered a proinflammatory mediator in many inflammatory diseases such as rheumatoid arthritis. However, mice lacking CCR2 develop exacerbated collagen-induced arthritis. To explore the underlying mechanism, we investigated whether autoimmune-associated Th17 cells were involved in the pathogenesis of the severe phenotype of autoimmune arthritis. We found that Th17 cells were expanded approximately 3-fold in the draining lymph nodes of immunized CCR2^−/− mice compared to WT controls (p = 0.017), whereas the number of Th1 cells and regulatory T cells are similar between these two groups of mice. Consistently, levels of the Th17 cell cytokine IL-17A and Th17 cell-associated cytokines, IL-6 and IL-1β were approximately 2–6-fold elevated in the serum and 22–28-fold increased in the arthritic joints in CCR2^−/− mice compared to WT mice (p = 0.04, 0.0004, and 0.01 for IL-17, IL-6, and IL-1β, respectively, in the serum and p = 0.009, 0.02, and 0.02 in the joints). Furthermore, type II collagen-specific antibodies were significantly increased, which was accompanied by B cell and neutrophil expansion in CCR2^−/− mice. Finally, treatment with an anti-IL-17A antibody modestly reduced the disease severity in CCR2^−/− mice. Therefore, we conclude that while we detect markedly enhanced Th17-cell responses in collagen-induced arthritis in CCR2-deficient mice and IL-17A blockade does have an ameliorating effect, factors additional to Th17 cells and IL-17A also contribute to the severe autoimmune arthritis seen in CCR2 deficiency. CCR2 may have a protective role in the pathogenesis of autoimmune arthritis. Our data that monocytes were missing from the spleen while remained abundant in the bone marrow and joints of immunized CCR2^−/− mice suggest that there is a potential link between CCR2-expressing monocytes and Th17 cells during autoimmunity.

The role of the extracellular matrix protein mindin in airway response to environmental airways injury

BACKGROUND

Our previous work demonstrated that the extracellular matrix protein mindin contributes to allergic airways disease. However, the role of mindin in nonallergic airways disease has not previously been explored.

OBJECTIVES

We hypothesized that mindin would contribute to airways disease after inhalation of either lipopolysaccharide (LPS) or ozone.

METHODS

We exposed C57BL/6J and mindin-deficient (-/-) mice to aerosolized LPS (0.9 μg/m3 for 2.5 hr), saline, ozone (1 ppm for 3 hr), or filtered air (FA). All mice were evaluated 4 hr after LPS/saline exposure or 24 hr after ozone/FA exposure. We characterized the physiological and biological responses by analysis of airway hyperresponsiveness (AHR) with a computer-controlled small-animal ventilator (FlexiVent), inflammatory cellular recruitment, total protein in bronchoalveolar lavage fluid (BALF), proinflammatory cytokine profiling, and ex vivo bronchial ring studies.

RESULTS

After inhalation of LPS, mindin-/- mice demonstrated significantly reduced total cell and neutrophil recruitment into the airspace compared with their wild-type counterparts. Mindin-/- mice also exhibited reduced proinflammatory cytokine production and lower AHR to methacholine challenge by FlexiVent. After inhalation of ozone, mice had no detectible differences in cellular inflammation or total BALF protein dependent on mindin. However, mindin-/- mice were protected from increased proinflammatory cytokine production and AHR compared with their C57BL/6J counterparts. After ozone exposure, bronchial rings derived from mindin-/- mice demonstrated reduced constriction in response to carbachol.

CONCLUSIONS

These data demonstrate that the extracellular matrix protein mindin modifies the airway response to both LPS and ozone. Our data support a conserved role of mindin in production of proinflammatory cytokines and the development of AHR in two divergent models of reactive airways disease, as well as a role of mindin in airway smooth muscle contractility after exposure to ozone.

Intracerebral administration of recombinant rabies virus expressing GM-CSF prevents the development of rabies after infection with street virus

Recently it was found that prior immunization with recombinant rabies virus (RABV) expressing granulocyte-macrophage colony-stimulating factor (GM-CSF) (LBNSE-GM-CSF) resulted in high innate/adaptive immune responses and protection against challenge with virulent RABV (Wen et al., JVI, 2011). In this study, the ability of LBNSE-GM-CSF to prevent animals from developing rabies was investigated in mice after infection with lethal doses of street RABV. It was found that intracerebral administration of LBNSE-GM-CSF protected more mice from developing rabies than sham-treated mice as late as day 5 after infection with street RABV. Intracerebral administration of LBNSE-GM-CSF resulted in significantly higher levels of chemokine/cytokine expression and more infiltration of inflammatory and immune cells into the central nervous system (CNS) than sham-administration or administration with UV-inactivated LBNSE-GM-CSF. Enhancement of blood-brain barrier (BBB) permeability and increases in virus neutralizing antibodies (VNA) were also observed in mice treated with LBNSE-GM-CSF. On the other hand, intracerebral administration with UV-inactivated LBNSE-GM-CSF did not increase protection despite the fact that VNA were induced in the periphery. However, intracerebral administration with chemoattractant protein-1 (MCP-1, also termed CCL2) increased significantly the protective efficacy of UV-inactivated LBNSE-GM-CSF. Together these studies confirm that direct administration of LBNSE-GM-CSF can enhance the innate and adaptive immunity as well as the BBB permeability, thus allowing infiltration of inflammatory cells and other immune effectors enter into the CNS to clear the virus and prevent the development of rabies.

HIV-1 Tat-induced microgliosis and synaptic damage via interactions between peripheral and central myeloid cells

Despite the ability of combination antiretroviral treatment (cART) to reduce viral burden to nearly undetectable levels in cerebrospinal fluid and serum, HIV-1 associated neurocognitive disorders (HAND) continue to persist in as many as half the patients living with this disease. There is growing consensus that the actual substrate for HAND is destruction of normal synaptic architecture but the sequence of cellular events that leads to this outcome has never been resolved. To address whether central vs. peripheral myeloid lineage cells contribute to synaptic damage during acute neuroinflammation we injected a single dose of the HIV-1 transactivator of transcription protein (Tat) or control vehicle into hippocampus of wild-type or chimeric C57Bl/6 mice genetically marked to distinguish infiltrating and resident immune cells. Between 8–24 hr after injection of Tat, invading CD11b⁺ and/or myeloperoxidase-positive leukocytes with granulocyte characteristics were found to engulf both microglia and synaptic structures, and microglia reciprocally engulfed invading leukocytes. By 24 hr, microglial processes were also seen ensheathing dendrites, followed by inclusion of synaptic elements in microglia 7 d after Tat injection, with a durable microgliosis lasting at least 28 d. Thus, central nervous system (CNS) exposure to Tat induces early activation of peripheral myeloid lineage cells with phagocytosis of synaptic elements and reciprocal microglial engulfment of peripheral leukocytes, and enduring microgliosis. Our data suggest that a single exposure to a foreign antigen such as HIV-1 Tat can lead to long-lasting disruption of normal neuroimmune homeostasis with deleterious consequences for synaptic architecture, and further suggest a possible mechanism for enduring neuroinflammation in the absence of productive viral replication in the CNS.

The appearance of renal cells cytoplasmic degeneration and nuclear destruction might be an indication of GNPs toxicity

BACKGROUND

Advances in nanotechnology have identified promising candidates for many biological and biomedical applications. Since the properties of nanoparticles (NPs) differ from that of their bulk materials, they are being increasingly exploited for medical uses and other industrial applications. The histological and the histochemical alterations in the renal tissues due to gold nanoparticles (GNPs) have not well documented and have not yet been identified. The aim of the present study was to investigate the particle-size effect of GNPs on the renal tissue in an attempt to address their potential toxicity.

METHODS

A total of 70 healthy male Wistar-Kyoto rats were exposed to GNPs received 50 or 100 μl of GNPs infusion of size (10, 20 and 50 nm for 3 or 7 days) to investigate particle-size effect of GNPs on the renal tissue. Animals were randomly divided into groups, 6 GNPs-treated rats groups and one control group. Groups 1, 2 and 3 received infusion of 50 μl GNPs of size 10 nm (3 or 7 days), size 20 nm (3 or 7 days) and 50 nm (3 or 7 days), respectively; while groups 4, 5 and 6 received infusion of 100 μl GNPs of size 10 nm, size 20 nm and 50 nm, respectively.

RESULTS

The histological alterations were mainly seen in the cortex and the proximal renal convoluted tubules were more affected than the distal ones. In comparison with respective control rats, exposure to GNPs doses has produced the following renal tubular alterations: cloudy swelling and renal tubular necrosis. Interstitial alterations included: intertubular blood capillaries dilatation, intertubular hemorrhage and inflammatory cell infiltrations. The glomeruli showed moderate congestion with no hypercelluraity and mesangial proliferation or basement membrane thickening.

CONCLUSIONS

The induced histological alterations might be an indication of injured renal tubules due to GNPs toxicity that become unable to deal with the accumulated residues resulting from metabolic and structural disturbances caused by these NPs. These alterations were size-dependent with smaller ones induced more effects and related with time exposure of GNPs. The produced histological alterations may suggest that GNPs interact with proteins and enzymes of the renal tissue interfering with the antioxidant defense mechanism and leading to reactive oxygen species (ROS) generation which in turn may induce stress in the renal cells to undergo atrophy and necrosis. More histomorphologcal investigations are needed to address the potential threat of GNPs as a therapeutic and diagnostic tool.

Natural almond skin reduced oxidative stress and inflammation in an experimental model of inflammatory bowel disease

The aim of the present study was to examine the effects of natural almond skin (NS) powder in mice subjected to experimental colitis. Colitis was induced in mice by intracolonic instillation of dinitrobenzene sulfonic acid (DNBS). NS powder was administered daily orally (30 mg/kg). Four days after DNBS administration, colon NF-κB and p-JNK activation was increased as well as TNF-α and IL-1β productions. Neutrophil infiltration, by myeloperoxidase (MPO) activity, in the mucosa was associated with up-regulation of ICAM-1 and P-selectin. Immunohistochemistry for i-NOS, nitrotyrosine and poly (ADP-ribose) polymerase (PARP) showed an intense staining in the inflamed colon. Treatment with NS powder significantly reduced the appearance of diarrhea and body weight loss. This was associated with a significant reduction in colonic MPO activity. NS powder also reduced NF-κB and p-JNK activation, the pro-inflammatory cytokines release, the appearance of i-NOS, nitrotyrosine and PARP in the colon and reduced the up-regulation of ICAM-1 and the expression of P-selectin. The results of this study suggested that administration of NS powder may be beneficial for treatment of inflammatory bowel disease.

Effect of garlic oil on neutrophil infiltration in the small intestine of endotoxin-injected rats and its association with levels of soluble and cellular adhesion molecules

Garlic ( Allium sativum ) possesses anti-inflammatory effects. This study investigated the effects of garlic oil on endotoxin-induced neutrophil infiltration in the small intestine. Wistar rats received by gavage 10, 50, or 100 mg/kg body wt garlic oil (GO) or the vehicle (corn oil; 2 mL/kg body wt) every other day for 2 weeks before being injected with endotoxin (ip, 5 mg/kg body wt). Control rats were administered corn oil and injected with sterile saline. Blood samples for the measurement of soluble adhesion molecules were collected at various time points after injection, and all other samples were collected 18 h after injection. The 10 and 50 mg/kg doses suppressed endotoxin-induced neutrophilia, serum levels of sL-selectin and sICAM-1, cellular CD11b on neutrophils, intestinal ICAM-1 content, and neutrophil infiltration (P < 0.05). The 100 mg/kg dose significantly lowered local ICAM-1 and cellular CD11b on neutrophils (P < 0.05) but did not have a beneficial effect on neutrophil infiltration. In addition, 100 mg/kg of GO worsened the elevation of the local TNF-α level and neutrophilia. Appropriate doses of garlic oil have a preventive effect on endotoxin-induced neutrophil infiltration and damage to the small intestine.