Improved myeloperoxidase assay for quantitation of neutrophil influx in a rat model of endotoxin-induced uveitis

Qi-Zhi-Wei-Tong granules alleviates chronic non-atrophic gastritis in mice by altering the gut microbiota and bile acid metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine, Qi-zhi-wei-tong granule (QZWT) significantly reduced the major gastrointestinal and psychological symptoms of functional dyspepsia.

AIM OF THE STUDY

We aimed to explore the therapeutic effect of QZWT treated chronic non-atrophic gastritis (CNAG) and to elucidate its potential mechanism.

MATERIALS AND METHODS

The composition of QZWT was analysed by UPLC-Q/TOF-MS. The CNAG mice model was established by chronic restraint stress (CRS) in combination with iodoacetamide (IAA). Morphological staining was utilized to reveal the impact of QZWT on stomach and gut integrity. RT‒qPCR and ELISA were used to measure proinflammatory cytokines in the stomach, colon tissues and serum of CNAG mice. Next-generation sequencing of 16 S rDNA was applied to analyse the gut microbiota community of faecal samples. Finally, we investigated the faecal bile acid composition using GC‒MS.

RESULTS

Twenty-one of the compounds from QZWT were successfully identified by UPLC-Q/TOF-MS analysis. QZWT enhanced gastric and intestinal integrity and suppressed inflammatory responses in CNAG mice. Moreover, QZWT treatment reshaped the gut microbiota structure by increasing the levels of the Akkermansia genus and decreasing the populations of the Desulfovibrio genus in CNAG mice. The alteration of gut microbiota was associated with gut bacteria BA metabolism. In addition, QZWT reduced BAs and especially decreased conjugated BAs in CNAG mice. Spearman's correlation analysis further confirmed the links between the changes in the gut microbiota and CNAG indices.

CONCLUSIONS

QZWT can effectively inhibited gastrointestinal inflammatory responses of CNAG symptoms in mice; these effects may be closely related to restoring the balance of the gut microbiota and regulating BA metabolism to protect the gastric mucosa. This study provides a scientific reference for the pathogenesis of CNAG and the mechanism of QZWT treatment.

Efficacy and Safety Evaluation of Mometasone Furoate in Treating Ocular Inflammation

Mometasone furoate (MF) is a medium-potency synthetic glucocorticosteroid with anti-inflammatory, antipruritic, and vasoconstrictive properties. However, its role in the treatment of ocular inflammation has not yet been explored. This work investigated the anti-inflammatory activity of MF in ocular tissues. First, the in vivo safety of the intravitreal (IVT) injection of MF (80, 160, and 240 µg) was evaluated via clinical examination (including the assessment of intraocular pressure), electroretinography (ERG), and histopathology. Second, MF was tested in an experimental model of bacillus Calmette-Guérin (BCG)-induced uveitis in Wistar rats. Intraocular inflammation was then evaluated via a slit-lamp and fundus examination, ERG, histopathology, and the quantification of pro-inflammatory markers. Intravitreal MF showed no toxicity in all the investigated doses, with 160 µg leading to attenuated disease progression and improvement in clinical, morphological, and functional parameters. There was a significant reduction in the levels of inflammatory markers (myeloperoxidase, interleukins 6 and 1β, CXCL-1, and tumor necrosis factor-alpha) when compared to the levels in untreated animals. Therefore, MF should be further investigated as a promising drug for the treatment of ocular inflammation.

Antimicrobial effects of hydroxyapatite mosaicked polyvinyl alcohol-alginate semi-interpenetrating hydrogel-loaded with ethanolic extract of Glycyrrhiza glabra against oral pathogens

Glycyrrhiza glabra (GG) elicits protective effects against periodontal diseases. However, the sustained bioavailability of GG extract at therapeutic concentration warrants ideal delivery vehicles. Present study has focused on the design, fabrication, and evaluations of ethanolic-crude extract of GG-loaded semi-interpenetrating network (semi-IPN) hydrogel (HAAPS-GG) using alginic acid and polyvinyl alcohol (PVA) hydrogel mosaicked with HA for periodontal regeneration. The study has examined the performance of the hydrogel against the selected oral pathogens S. mutans, E. faecalis, L. acidophilus and C. albicans. HAAPS-GG was successfully fabricated and the surface functional groups were confirmed by attenuated total reflectance-infrared (ATR-IR) spectroscopy. HAAPS-GG displayed interconnecting pores, hydrophilicity and excellent water profile contributing to the biocompatibility as evident from direct contact and MTT assay in L929 fibroblasts. The hydrogel was mechanically stable and was immunocompatible owing to the relatively decreased levels of pro-inflammatory mediators COX2, 5LPO, iNOS and MPO in RAW 264.7 macrophages. In addition, the transcript analysis on RAW 264.7 revealed the down-regulation of inflammatory transcription factor NF-κβ and the pro-inflammatory cytokine TNF-α. Importantly, HAAPS-GG arrested the progression of periodontal pathogens predominantly S. mutans, and C. albicans as evident by disc diffusion assay, MTT assay and confocal microscopy. Overall, the HAAPS-GG system offers promising translational avenues in periodontal regeneration.

Antioxidant Analogue 6-Amino-2,4,5-Trimethylpyridin-3-ol Ameliorates Experimental Colitis in Mice

BACKGROUND

Oxidative stress has been suggested to be a factor contributing to the disease severity of inflammatory bowel disease (IBD). BJ-1108, a derivative of 6-amino-2,4,5-trimethylpyridin-3-ol, is reported to significantly inhibit the generation of reactive oxygen species (ROS) in vitro. However, whether this molecule affects intestinal inflammation is largely unknown. We aimed to investigate the effect of BJ-1108 on dextran sulfate sodium (DSS)-induced experimental colitis in mice.

METHODS

Colitis was induced in mice with DSS, and disease severity was estimated by evaluating body weight, colon length, histology, immune cell infiltration, and intestinal permeability. We examined the protective effects of BJ-1108 on barrier function using Caco-2 cells. Last, we estimated the impact of BJ-1108 on the phosphorylation of NF-kB, PI3K/AKT, and mitogen-activated protein kinases.

RESULTS

Mice treated with BJ-1108 exhibited improved disease severity, as indicated by evaluations of body weight, histological scores, spleen weight, and infiltrates of T cells and macrophages. The administration of BJ-1108 inhibited the colonic mRNA expression of IL-6 and IL-1β in vivo. Additionally, BJ-1108 limited intestinal permeability and enhanced the expression of tight junction (TJ) proteins such as claudin-1 and claudin-3 in the DSS-induced colitis model. In an in vitro model using Caco-2 cells, BJ-1108 ameliorated cytokine-induced ROS generation in a dose-dependent manner and remarkably recovered barrier dysfunction as estimated by evaluating transepithelial electrical resistance and TJ protein expression. BJ-1108 suppressed the NF-kB/ERK/PI3K pathway.

CONCLUSIONS

This study demonstrated that BJ-1108 ameliorated intestinal inflammation in an experimental colitis mouse model, suggesting possible therapeutic implications for IBD.

nNOS induction and NOSIP interaction impact granulopoiesis and neutrophil differentiation by modulating nitric oxide generation

Nitric oxide (NO), a versatile free radical and a signalling molecule, plays an important role in the haematopoiesis, inflammation and infection. Impaired proliferation and differentiation of myeloid cells lead to malignancies and Hematopoietic deficiencies. This study was aimed to define the role of nNOS derived NO in neutrophil differentiation (in-vitro) and granulopoiesis (in-vivo) using multipronged approaches. The results obtained from nNOS over-expressing K562 cells revealed induction in C/EBPα derived neutrophil differentiation as evident by an increase in the expression of neutrophil specific cell surface markers, genes, transcription factors and functionality. nNOS mediated response also involved G-CSFR-STAT-3 axis during differentiation. Consistent increase in NO generation was observed during neutrophil differentiation of mice and human CD34⁺ HSPCs. Furthermore, granulopoiesis was abrogated in the nNOS inhibitor treated mice, depicting a decrease in the numbers of BM mature and progenitor neutrophils. Likewise, in vitro inhibition of nNOS in human CD34⁺ HSPCs indicated an indispensable role of nNOS in neutrophil differentiation. Expression of nNOS inhibitory protein, NOSIP was significantly and consistently decreased during the final stage of differentiation and was linked with the augmentation in NO release. Moreover, neutrophils from CML patients had more NOSIP and less NO generation as compared to the PMNs from healthy individuals. The present study thus indicates a critical role of nNOS, and its interaction with NOSIP during neutrophil differentiation. The study also highlights the importance of nNOS in the neutrophil progenitor proliferation and differentiation warranting investigations to assess its role in the haematopoiesis-related disorders.

Sirolimus-Loaded Intravitreal Implant for Effective Treatment of Experimental Uveitis

Non-infectious uveitis, an ocular inflammatory condition that affects the iris, ciliary body, choroid, and adjacent tissues (retina, optic nerve, and vitreous), is an important cause of blindness worldwide. Sirolimus (SRL), a potent immunomodulatory drug, has shown promising results in the treatment of inflammatory ocular diseases. Despite this therapeutic potential, its clinical use is a major challenge due to low bioavailability and poor solubility. Poly(lactic-co-glycolic acid) (PLGA) is a biodegradable polymer commonly used for ophthalmic drug delivery due to its suitable characteristics such as biocompatibility, good mechanical properties, and improvement of the pharmacokinetic profile of the drug. In the present study, we investigated the effects of SRL-PLGA implant on experimental autoimmune uveitis in rabbits. Clinical and histopathological examinations were performed, followed by assessment of protein levels and determination of myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) activity in the aqueous humor/vitreous. As a result, treated eyes had decreased average inflammatory scores, protein significant decreases in treated eyes, assessed after 35 days. Histopathological examination showed less severe intraocular inflammation and decreased tissue damage in treated eyes. According to these results, the SRL-PLGA implant evaluated in this study was apparently safe, reducing inflammation in treated eyes, with an extended effect possibly associated with prolonged release of SRL in the posterior segment of the eye. Therefore, intravitreal SRL-PLGA implant could be a promising alternative for treatment of non-infectious uveitis.

In vivo effect of quantified flavonoids-enriched extract of Scutellaria baicalensis root on acute lung injury induced by influenza A virus

BACKGROUND

Scutellaria baicalensis root is traditionally used for the treatment of common cold, fever and influenza. Flavonoids are the major chemical components of S. baicalensis root.

PURPOSE

To evaluate the therapeutic effects and action mechanism of flavonoids-enriched extract from S. baicalensis root (FESR) on acute lung injury (ALI) induced by influenza A virus (IAV) in mice.

METHODS

The anti-influenza, anti-inflammatory and anti-complementary properties of FESR and the main flavonoids were evaluated in vitro. Mice were challenged intranasally with influenza virus H1N1 (A/FM/1/47) 2  h before treatment. FESR (50, 100 and 200  mg/kg) was administrated intragastrically. Baicalin (BG), the most abundant compound in FESR was given as reference control. Survival rates, life spans and lung indexes of IAV-infected mice were measured. Histopathological changes, virus levels, inflammatory markers and complement deposition in lungs were analyzed.

RESULT

Compared with the main compound BG, FESR and lower content aglycones (baicalein, oroxylin A, wogonin and chrysin) in FESR significantly inhibited H1N1 activity in virus-infected Madin-Darby canine kidney (MDCK) cells and markedly decreased nitric oxide (NO) production from lipopolysaccharide (LPS)-stimulated RAW264.7 cells. In vitro assays showed that FESR and BG had no anti-complementary activity whereas baicalein, oroxylin A, wogonin and chrysin exhibited obvious anti-complementary activity. Oral administration of FESR effectively protected the IAV-infected mice, increased the survival rate (FESR: 67%; BG: 33%), decreased the lung index (FESR: 0.90; BG: 1.00) and improved the lung morphology in comparing with BG group. FESR efficiently decreased lung virus titers, reduced haemagglutinin (HA) titers and inhibited neuraminidase (NA) activities in lungs of IAV-infected mice. FESR modulated the inflammatory responses by decreasing the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1), and increasing the levels of interferon-γ (IFN-γ) and interleukin-10 (IL-10) in lung tissues. Although showing no anti-complementary activity in vitro, FESR obviously reduced complement deposition and decreased complement activation product level in the lung .

CONCLUSION

FESR has a great potential for the treatment of ALI induced by IAV and the underlying action mechanism might be closely associated with antiviral, anti-inflammatory and anti-complementary properties. Furthermore, FESR resulted in more potent therapeutic effect than BG in the treatment of IAV-induced ALI.

Protective effect of oxytocin on LPS-induced acute lung injury in mice

Oxytocin (OT), a neurohypophyseal hormone synthesized in the paraventricular and supraoptic nuclei of the hypothalamus, has been reported to have an anti- inflammatory effect. However, its role in acute lung injury (ALI) has never been investigated. The aim of this study was to explore the therapeutic effects and potential mechanism action of OT on lipopolysaccharide (LPS)-induced ALI. Mice were treated with OT 30 min before the intraperitoneal injection of LPS. After 2 h, the effects of OT on lung histopathological changes, lung wet/dry (W/D) ratio, myeloperoxidase (MPO) activity, levels of inflammatory cytokines in the bronchoalveolar lavage fluid (BALF), and expression of inflammation proteins were detected. The results showed that OT significantly reduced LPS-induced pathological injury, W/D ratio, MPO activity, and the levels of interleukin (IL)-1β, IL-18 and IL-6. Further, OT also inhibited LPS-induced Toll-like receptor 4 expression and NLR family pyrin domain containing 3 inflammasome activation. OT receptor antagonist (L-368,899) was given 90 min before injecting OT to further demonstrate the role of OT in LPS-induced ALI. The results showed OT could not alleviate the aforementioned inflammatory reactions after administering L-368,899. In conclusion, the present results indicated that OT could reduce inflammatory responses of LPS-induced ALI.

A novel synthetic small molecule DMFO targets Nrf2 in modulating proinflammatory/antioxidant mediators to ameliorate inflammation

Inflammation is a protective immune response against invading pathogens, however, dysregulated inflammation is detrimental. As the complex inflammatory response involves multiple mediators, including the involvement of reactive oxygen species, concomitantly targeting proinflammatory and antioxidant check-points may be a more rational strategy. We report the synthesis and anti-inflammatory/antioxidant activity of a novel indanedione derivative DMFO. DMFO scavenged reactive oxygen species (ROS) in in-vitro radical scavenging assays and in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. In acute models of inflammation (carrageenan-induced inflammation in rat paw and air pouch), DMFO effectively reduced paw oedema and leucocyte infiltration with an activity comparable to diclofenac. DMFO stabilised mast cells (MCs) in in-vitro A23187 and compound 48/80-induced assays. Additionally, DMFO stabilised MCs in an antigen (ovalbumin)-induced MC degranulation model in-vivo, without affecting serum IgE levels. In a model of chronic immune-mediated inflammation, Freund's adjuvant-induced arthritis, DMFO reduced arthritic score and contralateral paw oedema, and increased the pain threshold with an efficacy comparable to diclofenac but without being ulcerogenic. Additionally, DMFO significantly reduced serum TNFα levels. Mechanistic studies revealed that DMFO reduced proinflammatory genes (IL1β, TNFα, IL6) and protein levels (COX2, MCP1), with a concurrent increase in antioxidant genes (NQO1, haem oxygenase 1 (HO-1), Glo1, Nrf2) and protein (HO-1) in LPS-stimulated macrophages. Importantly, the anti-inflammatory/antioxidant effect on gene expression was absent in primary macrophages isolated from Nrf2 KO mice suggesting an Nrf2-targeted activity, which was subsequently confirmed using siRNA transfection studies in RAW macrophages. Therefore, DMFO is a novel, orally-active, safe (even at 2 g/kg p.o.), a small molecule which targets Nrf2 in ameliorating inflammation.

25-Hydroxycholesterol protects against acute lung injury via targeting MD-2

Acute lung injury (ALI) is mainly caused by uncontrolled inflammatory response, and it remains without effective therapeutic options. 25‐hydroxycholesterol (25HC) has been reported to be a potent regulator of inflammation. The aim of this study was to investigate the effects of 25HC on lipopolysaccharide (LPS)‐induced ALI. C57BL/6 mice were pretreated with 25HC intraperitoneally before intratracheal exposure to LPS. Our results showed that 25HC pretreatment improved survival rate, attenuated the pathological changes of the lung and decreased the release of inflammatory cytokines in mice. Consistently, 25HC reduced expression of Toll‐like receptor (TLR4)‐mediated inflammatory cytokines in vitro. These effects of 25HC were obtained by preventing LPS binding to TLR4 via interaction with myeloid differentiation protein 2 (MD‐2). Crystal structure analysis suggested that 25HC could bind MD‐2 with high affinity into its hydrophobic pocket. Furthermore, LPS‐induced activation of Akt/NF‐κB pathway was partially down‐regulated by 25HC pretreatment. In summary, this study demonstrates that 25HC could inhibit the overwhelming inflammatory response through MD‐2 interaction, which suppresses Akt/NF‐κB signalling pathway. These findings suggest 25HC may be a promising candidate for ALI prevention.

Catechin ameliorates doxorubicin-induced neuronal cytotoxicity in in vitro and episodic memory deficit in in vivo in Wistar rats

Cognitive dysfunction by chemotherapy compromises the quality of life in cancer patients. Tea polyphenols are known chemopreventive agents. The present study was designed to evaluate the neuroprotective potential of (+) catechin hydrate (catechin), a tea polyphenol, in IMR-32 neuroblastoma cells in vitro and alleviation of episodic memory deficit in Wistar rats in vivo against a widely used chemotherapeutic agent, Doxorubicin (DOX). In vitro, neuroprotective studies were assessed in undifferentiated IMR-32 cells using percentage viability and in differentiated cells by neurite length. These studies showed catechin increased percentage viability of undifferentiated IMR-32 cells. Catechin pretreatment also showed an increase in neurite length of differentiated cells. In vivo neuroprotection of catechin was evaluated using novel object recognition task in time-induced memory deficit model at 50, 100 and 200 mg/kg dose and DOX-induced memory deficit models at 100 mg/kg dose. The latter model was developed by injection of DOX (2.5 mg/kg, i.p.) in 10 cycles over 50 days in Wistar rats. Catechin showed a significant reversal of time-induced memory deficit in a dose-dependent manner and prevention of DOX-induced memory deficit at 100 mg/kg. In addition, catechin treatment showed a significant decrease in oxidative stress, acetylcholine esterase and neuroinflammation in the hippocampus and cerebral cortex in DOX-induced toxicity model. Hence, catechin may be a potential adjuvant therapy for the amelioration of DOX-induced cognitive impairment which may improve the quality of life of cancer survivors. This improvement might be due to the elevation of antioxidant defense, prevention of neuroinflammation and inhibition of acetylcholine esterase enzyme.

3, 4-dihydroxybenzalacetone attenuates lipopolysaccharide-induced inflammation in acute lung injury via down-regulation of MMP-2 and MMP-9 activities through suppressing ROS-mediated MAPK and PI3K/AKT signaling pathways

3, 4-Dihydroxybenzalacetone (DBL) is a constituent of Phellinus linteus. This study demonstrated the protective effect of DBL on lipopolysaccharide (LPS)-induced acute lung injuries in mice. Pretreatment with DBL significantly improved LPS-induced histological alterations in lung tissues. In addition, DBL markedly reduced the total cell number, the leukocytes, the protein concentrations, and decreased the release of nitrite, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and the activities of matrix metalloproteinase (MMP)-2 and -9 in the bronchoalveolar lavage fluid. DBL also inhibited the W/D ratio and myeloperoxidase activity in the lung tissues. Western blot analysis indicated DBL efficiently blocked the protein expressions of inducible nitric oxide synthase, cyclooxygenase-2, MMP-2, MMP-9, and the phosphorylation of mitogen-activated protein kinase (MAPK), phosphoinositide-3-kinase (PI3K), AKT, Toll-like receptor 4 (TLR4) and nuclear factor (NF)-κB. Moreover, DBL enhanced the expression of anti-oxidant proteins, such as superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx). Based on our results, DBL might be a potential target for attenuating tissue oxidative injuries and nonspecific pulmonary inflammation.

Protective Effects of Platycodin D on Lipopolysaccharide-Induced Acute Lung Injury by Activating LXRα-ABCA1 Signaling Pathway

The purpose of this study was to investigate the protective effects of platycodin D (PLD) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and clarify the possible mechanism. An LPS-induced ALI model was used to confirm the anti-inflammatory activity of PLD in vivo. The A549 lung epithelial cells were used to investigate the molecular mechanism and targets of PLD in vitro. In vivo, the results showed that PLD significantly attenuated lung histopathologic changes, myeloperoxidase activity, and pro-inflammatory cytokines levels, including TNF-α, IL-1β, and IL-6. In vitro, PLD inhibited LPS-induced IL-6 and IL-8 production in LPS-stimulated A549 lung epithelial cells. Western blot analysis showed that PLD suppressed LPS-induced NF-κB and IRF3 activation. Moreover, PLD did not act though affecting the expression of TLR4. We also showed that PLD disrupted the formation of lipid rafts by depleting cholesterol and prevented LPS-induced TLR4 trafficking to lipid rafts, thereby blocking LPS-induced inflammatory response. Finally, PLD activated LXRα–ABCA1-dependent cholesterol efflux. Knockdown of LXRα abrogated the anti-inflammatory effects of PLD. The anti-inflammatory effects of PLD was associated with upregulation of the LXRα–ABCA1 pathway, which resulted in disrupting lipid rafts by depleting cholesterol and reducing translocation of TLR4 to lipid rafts.

Extraction, characterization and evaluation of Kaempferia galanga L. (Zingiberaceae) rhizome extracts against acute and chronic inflammation in rats

ETHNOPHARMACOLOGICAL RELEVANCE

The rhizomes of an acaulescent perennial herb, Kaempferia galanga Linn (Family: Zingiberaceae), used as traditional ayurvedic herb to get relief from indigestion, swelling, pain, high blood pressure and dyslipidemia.

AIM OF THE STUDY

To prepare and characterize various extracts of Kaempferia galanga (K. galanga) for their comparative evaluation for the identification of the most efficacious extract and its possible pharmacological implication in acute and chronic inflammatory paradigm.

MATERIALS AND METHODS

Dried and powdered rhizome of K. galanga was subjected to alcoholic extraction as well as successive extractions with various solvents. After phytochemical characterization, all the extracts were standardized for the presence of ethyl-p-methoxycinnamate. The extracts, and the isolated compound, were tested against carrageenan-induced acute inflammation in rats. The most promising extract was tested against adjuvant-induced chronic inflammation in rats. Further, local myeloperoxidase (MPO) levels were investigated to establish the possible mechanism of action.

RESULTS

Among the extracts, petroleum ether extract (SKG-1) and crude alcoholic extract (KG) had the maximum quantity of ethyl-p-methoxycinnamate. SKG-1 (300mg/kg) was found effective against acute inflammation in rats. Further, SKG-1 (100mg/kg) reversed the inflammation and elevated MPO levels found in the chronic model.

CONCLUSIONS

The results suggest that among all the extracts of K. galanga, SKG-1 effectively suppresses the progression of acute and chronic inflammation in rats by inhibition of neutrophil infiltration.

Importance of the Evaluation of N-Acetyltransferase Enzyme Activity Prior to 5-Aminosalicylic Acid Medication for Ulcerative Colitis

BACKGROUND

5-aminosalicylic acid (5-ASA) is a classic anti-inflammatory drug for the treatment of ulcerative colitis. N-acetyltransferase (NAT) enzymes convert 5-ASA to its metabolite N-acetyl-5-ASA, and it is unresolved whether 5-ASA or N-acetyl-5-ASA is the effective therapeutic molecule. We previously demonstrated that colonic production of N-acetyl-5-ASA (NAT activity) is decreased in dextran sulfate sodium-induced colitis. Our hypothesis is that 5-ASA is the therapeutic molecule to improve colitis, with the corollary that altered NAT activity affects drug efficacy. Since varying clinical effectiveness of 5-ASA has been reported, we also ask if NAT activity varies with inflammation in pediatric or adult patients.

METHODS

Acute colonic inflammation was induced in C57BL/6 NAT wild-type (WT) or knockout mice, using 3.5% dextran sulfate sodium (w/v) concurrent with 5-ASA treatment. Adult and pediatric rectosigmoid biopsies were collected from control or patients with ulcerative colitis. Tissue was analyzed for NAT and myeloperoxidase activity.

RESULTS

Dextran sulfate sodium-induced colitis was of similar severity in both NAT WT and knockout mice, and NAT activity was significantly decreased in NAT WT mice. In the setting of colitis, 5-ASA significantly restored colon length and decreased myeloperoxidase activity in NAT knockout but not in WT mice. Myeloperoxidase activity negatively correlated with NAT activity in pediatric patients, but correlation was not observed in adult patients.

CONCLUSIONS

Inflammation decreases NAT activity in the colon of mice and human pediatric patients. Decreased NAT activity enhances the therapeutic effect of 5-ASA in mice. A NAT activity assay could be useful to help predict the efficacy of 5-ASA therapy.

An immunological method to combine the measurement of active and total myeloperoxidase on the same biological fluid, and its application in finding inhibitors which interact directly with the enzyme

Myeloperoxidase (MPO) is a pro-oxidant enzyme involved in inflammation, and the measurement of its activity in biological samples has emerged essential for laboratory and clinical investigations. We will describe a new method which combines the SIEFED (specific immunological extraction followed by enzymatic detection) and ELISA (ELISAcb) techniques to measure the active and total amounts of MPO on the same human sample and with the same calibration curve, as well as to define an accurate ratio between both the active and total forms of the enzyme. The SIEFED/ELISAcb method consists of the MPO extraction from aqueous or biological samples by immobilized anti-MPO antibodies coated onto microplate wells. After a washing step to eliminate unbound material, the activity of MPO is measured in situ by adding a reaction solution (SIEFED). Following aspiration of the reaction solution, a secondary anti-MPO antibody is added into the wells and the ELISAcb test is carried out in order to measure the total MPO content. To validate the combined method, a comparison was made with SIEFED and ELISA experiments performed separately on plasma samples isolated from human whole blood, after a neutrophil stimulation. The SIEFED/ELISAcb provides a suitable tool for the measurement of specific MPO activity in biological fluids and for the estimation of the inhibitory potential of a fluid. The method can also be used as a pharmacological tool to make the distinction between a catalytic inhibitor, which binds to MPO and inhibits its activity, and a steric inhibitor, which hinders the enzyme and prevents its immunodetection.

Novel 2,5-disubstituted-1,3,4-oxadiazoles as anti-inflammatory drugs

OBJECTIVE

1,3,4-oxadiazole ring is a versatile moiety with a wide range of pharmacological properties. The present work deals with the synthesis and evaluation of the anti-inflammatory activity of two novel 2,5-disubstituted-1,3,4-oxadiazoles (OSD and OPD).

MATERIALS AND METHODS

Carrageenan-induced rat hind paw edema was employed as an acute model of inflammation. For evaluating sub-acute anti-inflammatory activity, carrageenan-induced inflammation in rat air pouch was employed. Complete Freund's adjuvant-induced arthritis in rats was used as a model of chronic inflammation. To evaluate in vitro anti-inflammatory activity, lipopolysaccharide (LPS)-stimulated RAW264.7 cells were used.

RESULTS

OSD (100 mg/kg) reduced carrageen-induced paw edema by 60%, and OPD (100 mg/kg) produced a modest 32.5% reduction. OSD also reduced leukocyte influx and myeloperoxidase in carrageenan-induced rat air pouch model. In complete Freund's adjuvant-induced arthritis model, both OSD and OPD (200 mg/kg for 14 days) reduced paw edema and NO levels. In LPS-stimulated RAW264.7 cells, OSD and OPD inhibited formation of nitric oxide and reactive oxygen species, with OPD showing a better activity in comparison to OSD.

CONCLUSIONS

OSD was the better of the two compounds in in vivo models of inflammation. The o-phenol substitution at position 2 of oxadiazole ring in OSD may be responsible for its better in vivo anti-inflammatory activity. The ability of the compounds to inhibit LPS-induced pro-inflammatory mediator release suggests an anti-inflammatory mechanism targeting LPS-TLR4-NF-κB signalling pathway, which needs to be explored in detail. The disparate efficacy in vitro and in vivo also requires in-depth evaluation of the pharmacokinetics of these novel oxadiazoles.

Protective effect of veratric acid on lipopolysaccharide-induced acute lung injury in mice

Veratric acid, a simple benzoic acid derived from plants and fruits, has been reported to exhibit antibacterial, anti-inflammatory and other important therapeutic activities. The aim of this study was to detect the effects of veratric acid on LPS-induced acute lung injury and to investigate the effects of veratric acid on NF-κB signaling pathway. Male BALB/c mice were pretreated with dexamethasone or veratric acid 1h before intranasal instillation of LPS. 7h after LPS administration, the myeloperoxidase in lung tissues, lung wet/dry weight ratio and inflammatory cells in the bronchoalveolar lavage fluid (BALF) were determined. The effects of veratric acid on pro-inflammatory cytokines and signal pathways were analyzed by enzyme-linked immunosorbent assay (ELISA) and Western blotting. The results showed that veratric acid inhibited LPS-induced TNF-α, IL-6 and IL-1β production in a dose dependent manner. It was also observed that veratric acid attenuated lung histopathologic changes. The wet/dry weight ratio of lungs and the number of total cells, neutrophils, macrophages in the BALF were all decreased. Furthermore, veratric acid inhibited the phosphorylation of NF-κB p65 and IκB. These results indicate that veratric acid inhibits NF-κB signaling pathways to attenuate inflammatory injury induced by LPS. Veratric acid may be a potential therapeutic reagent for acute lung injury treatment.

Glycyrrhizin inhibits the inflammatory response in mouse mammary epithelial cells and a mouse mastitis model

Glycyrrhizin, a triterpene glycoside isolated from licorice root, is known to have anti-inflammatory activities. However, the effect of glycyrrhizin on mastitis has not been reported. The purpose of this study was to investigate the anti-inflammatory effect and mechanism of action of glycyrrhizin on lipopolysaccharide (LPS)-induced mastitis in mouse. An LPS-induced mouse mastitis model was used to confirm the anti-inflammatory activity of glycyrrhizin in vivo. Primary mouse mammary epithelial cells were used to investigate the molecular mechanism and targets of glycyrrhizin. In vivo, glycyrrhizin significantly attenuated the mammary gland histopathological changes, myeloperoxidase activity and infiltration of neutrophilic granulocytes and downregulated the expression of tumor necrosis factor-α, interleukin (IL)-1β and IL-6 caused by LPS. In vitro, glycyrrhizin dose-dependently inhibited the LPS-induced expression of tumor necrosis factor-α, IL-6, and RANTES. Western blot analysis showed that glycyrrhizin suppressed LPS-induced nuclear factor-κB and interferon regulatory factor 3 activation. However, glycyrrhizin did not inhibit nuclear factor-κB and interferon regulatory factor 3 activation induced by MyD88-dependent (MyD88, IKKβ) or TRIF-dependent (TRIF, TBK1) downstream signaling components. Moreover, glycyrrhizin did not act though affecting the function of CD14 or expression of Toll-like receptor 4. Finally, we showed that glycyrrhizin decreased the levels of cholesterol of lipid rafts and inhibited the translocation of Toll-like receptor 4 to lipid rafts. Moreover, glycyrrhizin activated ATP-binding cassette transporter A1, which could induce cholesterol efflux from lipid rafts. In conclusion, we find that the anti-inflammatory effects of glycyrrhizin may be attributable to its ability to activate ATP-binding cassette transporter A1. Glycyrrhizin might be a useful therapeutic reagent for the treatment of mastitis and other inflammatory diseases.

Experimental gastritis leads to anxiety- and depression-like behaviors in female but not male rats

Human and animals studies support the idea that there is a gender-related co-morbidity of pain-related and inflammatory gastrointestinal (GI) diseases with psychological disorders. This co-morbidity is the evidence for the existence of GI-brain axis which consists of immune (cytokines), neural (vagus nerve) and neuroendocrine (HPA axis) pathways. Psychological stress causes disturbances in GI physiology, such as altered GI barrier function, changes in motility and secretion, development of visceral hypersensitivity, and dysfunction of inflammatory responses. Whether GI inflammation would exert impact on psychological behavior is not well established. We examined the effect of experimental gastritis on anxiety- and depression-like behaviors in male and female Sprague-Dawley rats, and evaluated potential mechanisms of action. Gastritis was induced by adding 0.1% (w/v) iodoacetamide (IAA) to the sterile drinking water for 7 days. Sucrose preference test assessed the depression-like behavior, open field test and elevated plus maze evaluated the anxiety-like behavior. IAA treatment induced gastric inflammation in rats of either gender. No behavioral abnormality or dysfunction of GI-brain axis was observed in male rats with IAA-induced gastritis. Anxiety- and depression-like behaviors were apparent and the HPA axis was hyperactive in female rats with IAA-induced gastritis. Our results show that gastric inflammation leads to anxiety- and depression-like behaviors in female but not male rats via the neuroendocrine (HPA axis) pathway, suggesting that the GI inflammation can impair normal brain function and induce changes in psychological behavior in a gender-related manner through the GI-to-brain signaling.

The Myc 3' Wnt responsive element regulates neutrophil recruitment after acute colonic injury in mice

BACKGROUND

The Wnt/β-catenin pathway regulates intestinal development, homeostasis, and regeneration after injury. Wnt/β-catenin signaling drives intestinal proliferation by activating expression of the c-Myc proto-oncogene (Myc) through the Myc 3' Wnt responsive DNA element (Myc 3' WRE). In a previous study, we found that deletion of the Myc 3' WRE in mice caused increased MYC expression and increased cellular proliferation in the colon. When damaged by dextran sodium sulfate (DSS), the increased proliferative capacity of Myc 3' WRE(-/-) colonocytes resulted in a more rapid recovery compared with wild-type (WT) mice. In that study, we did not examine involvement of the immune system in colonic regeneration.

PURPOSE

To characterize the innate immune response in Myc 3' WRE(-/-) and WT mice during and after DSS-induced colonic injury.

METHODS

Mice were fed 2.5 % DSS in their drinking water for five days to induce colonic damage and were then returned to normal water for two or four days to recover. Colonic sections were prepared and neutrophils and macrophages were analyzed by immunohistochemistry. Cytokine and chemokine levels were analyzed by probing a cytokine array with colonic lysates.

RESULTS

In comparison with WT mice, there was enhanced leukocyte infiltration into the colonic mucosal and submucosal layers of Myc 3' WRE(-/-) mice after DSS damage. Levels of activated neutrophils were substantially increased in damaged Myc 3' WRE(-/-) colons as were levels of the neutrophil chemoattractants C5/C5a, CXCL1, and CXCL2.

CONCLUSION

The Myc 3' WRE regulates neutrophil infiltration into DSS-damaged colons.

Alpinetin attenuates inflammatory responses by interfering toll-like receptor 4/nuclear factor kappa B signaling pathway in lipopolysaccharide-induced mastitis in mice

Alpinetin, a novel plant flavonoid derived from Alpinia katsumadai Hayata, has been reported to exhibit anti-inflammatory properties. However, the effect of alpinetin on mastitis has not been investigated. The aim of this study was to investigate the protective effect of alpinetin against lipopolysaccharide (LPS)-induced mastitis and to clarify the possible mechanism. In the present study, primary mouse mammary epithelial cells and an LPS-induced mouse mastitis model were used to investigate the effect of alpinetin on mastitis and the possible mechanism. In vivo, we observed that alpinetin significantly attenuated the infiltration of neutrophilic granulocytes, and the activation of myeloperoxidase; down-regulated the level of pro-inflammatory cytokines, including TNF-α, IL-1β and IL-6; inhibited the phosphorylation of IκB-α, NF-κB p65 and the expression of TLR4, caused by LPS. In vitro, we also observed that alpinetin inhibited the expression of TLR4 and the production of TNF-α, IL-1β and IL-6 in LPS-stimulated primary mouse mammary epithelial cells. However, alpinetin could not inhibit the production of IL-1β and IL-6 in TNF-α-stimulated primary mouse mammary epithelial cells. In conclusion, our results suggest that the anti-inflammatory effects of alpinetin against LPS-induced mastitis may be due to its ability to inhibit TLR4-mediated NF-κB signaling pathways. Alpinetin may be a promising potential therapeutic reagent for mastitis treatment.

6b,11b-Dihydroxy-6b,11b-dihydro-7H-indeno[1,2-b]naphtho[2,1-d]furan-7-one (DHFO), a small molecule targeting NF-κB, demonstrates therapeutic potential in immunopathogenic chronic inflammatory conditions

6b,11b-Dihydroxy-6b,11b-dihydro-7H-indeno[1,2-b]naphtho[2,1-d]furan-7-one (DHFO), an easily synthesisable, orally bioavailable and relatively non-toxic small molecule synthesised in our lab, was previously reported to possess anti-oxidant, 5-lipoxygenase inhibitory, anti-inflammatory and peripheral analgesic activities. The present work deals with exploration of DHFO's efficacy in immunopathogenic chronic inflammatory conditions - arthritis and allergy. In carrageenan-induced inflammatory air pouch, which resembles the arthritic synovium, DHFO effectively reduced inflammatory redness and swelling and neutrophil infiltration. In complete Freund's adjuvant-induced arthritis, DHFO significantly decreased paw oedema and nitrite levels with efficacy comparable to diclofenac. DHFO inhibited neutrophil activation (observed as decreased myeloperoxidase levels), in both the in vivo models of inflammation. Interestingly, DHFO did not ulcerate the gastrointestinal tract, while diclofenac was observed to be extremely ulcerogenic. In antigen-induced active and passive anaphylaxis (allergy) models, DHFO dose-dependently prevented mesenteric mast cell (MC) degranulation with efficacy comparable to ketotifen. DHFO also inhibited compound 48/80 (C48/80)-induced paw oedema and peritoneal MC degranulation. DHFO stabilised p815 murine MCs stimulated by C48/80 and calcium ionophore-A23187, indicating an action downstream of calcium mobilisation. DHFO's anti-allergic mechanism could be two-pronged involving (1) inhibition of IgE production and/or (2) MC stabilisation. DHFO inhibited lipopolysaccharide (LPS)-induced pro-inflammatory mediator release (ROS, NO, IL-6 levels) and COX2 expression in RAW264.7 murine macrophages. Protein expression studies confirmed DHFO's ability to reduce nuclear levels of NF-κB in LPS-stimulated macrophages. Thus, DHFO is a promising non-ulcerogenic synthetic small molecule lead for immunopathogenic chronic inflammatory conditions.

Functional PU.1 in macrophages has a pivotal role in NF-κB activation and neutrophilic lung inflammation during endotoxemia

Although the role of ETS family transcriptional factor PU.1 is well established in macrophage maturation, its role in mature macrophages with reference to sepsis- related animal model has not been elucidated. Here, we report the in vivo function of PU.1 in mediating mature macrophage inflammatory phenotype by using bone marrow chimera mice with conditional PU.1 knockout. We observed that the expression of monocyte/macrophage-specific markers CD 11b, F4/80 in fetal liver cells, and bone marrow-derived macrophages were dependent on functional PU.1. Systemic inflammation as measured in terms of NF-κB reporter activity in lung, liver, and spleen tissues was significantly decreased in PU.1-deficient chimera mice compared with wild-type chimeras on lipopolysaccharide (LPS) challenge. Unlike wild-type chimera mice, LPS challenge in PU.1-deficient chimera mice resulted in decreased lung neu-trophilic inflammation and myeloperoxidase activity. Similarly, we found attenuated inflammatory gene expression (cyclooxygenase-2, inducible nitric-oxide synthase, and TLR4) and inflammatory cytokine secretion (IL-6, MCP-1, IL-1β, TNF-α, and neutrophilic chemokine keratinocyte-derived chemokine) in PU.1-deficient mice. Most importantly, this attenuated lung and systemic inflammatory phenotype was associated with survival benefit in LPS-challenged heterozygotic PU.1-deficient mice, establishing a novel protective mechanistic role for the lineage-specific transcription factor PU.1.

G-protein coupled receptor kinase 5 mediates lipopolysaccharide-induced NFκB activation in primary macrophages and modulates inflammation in vivo in mice

G-protein coupled receptor kinase-5 (GRK5) is a serine/threonine kinase discovered for its role in the regulation of G-protein coupled receptor signaling. Recent studies have shown that GRK5 is also an important regulator of signaling pathways stimulated by non-GPCRs. This study was undertaken to determine the physiological role of GRK5 in Toll-like receptor-4-induced inflammatory signaling pathways in vivo and in vitro. Using mice genetically deficient in GRK5 (GRK5(-/-) ) we demonstrate here that GRK5 is an important positive regulator of lipopolysaccharide (LPS, a TLR4 agonist)-induced inflammatory cytokine and chemokine production in vivo. Consistent with this role, LPS-induced neutrophil infiltration in the lungs (assessed by myeloperoxidase activity) was markedly attenuated in the GRK5(-/-) mice compared to the GRK5(+/+) mice. Similar to the in vivo studies, primary macrophages from GRK5(-/-) mice showed attenuated cytokine production in response to LPS. Our results also identify TLR4-induced NFκB pathway in macrophages to be selectively regulated by GRK5. LPS-induced IκBα phosphorylation, NFκB p65 nuclear translocation, and NFκB binding were markedly attenuated in GRK5(-/-) macrophages. Together, our findings demonstrate that GRK5 is a positive regulator of TLR4-induced IκBα-NFκB pathway as well as a key modulator of LPS-induced inflammatory response.

Anti-platelet effects of Curcuma oil in experimental models of myocardial ischemia-reperfusion and thrombosis

Extensive research on the mechanism of action and medicinal importance of curcumin obtained from turmeric (Curcuma longa) has unfolded its potential therapeutic value against many chronic ailments. Curcuma oil (C.oil), the highly lipophilic component from Curcuma longa has been documented for its neuroprotective efficacy against rat cerebral ischemia-reperfusion injury; however its effect on myocardial reperfusion injury remains unexplored. In the present study, effect of C.oil (500 mg/kg, po) was evaluated against myocardial ischemia-reperfusion induced injury in the rat model. C.oil failed to confer protection against cardiac injury, however significant reversal of ADP induced platelet aggregation (p<0.05) was evident in the same animals. Moreover, collagen and thrombin induced platelet aggregation (p<0.001) as well as tyrosine phosphorylation of various proteins in activated platelets was also suppressed. C.oil also offered significant protection against collagen-epinephrine induced thromboembolism in mice as well as augmented total time to occlusion against FeCl(3) induced arterial thrombosis in rats. C.oil however had no effect on coagulation parameters (TT, PT and aPTT) and exerted a mild effect on the bleeding time. Bioavailability of C.oil, as assessed by monitoring ar-turmerone, α,β-turmerone and curlone, was 13%, 11% and 7% respectively, indicating high systemic exposure. Moreover, longer mean residence time (MRT) of ar-turmerone (13.2h), α,β-turmerone (11.6h) and Curlone (14.0 h) and plasma elimination half lives in the range of 5.5 to 7.2h correlated with single 500 mg/kg dose regimen of C.oil. In the present study, C.oil thus seems to be an efficacious and safe anti-platelet agent which was protective against intravascular thrombosis.

Functional and molecular characterization of NOS isoforms in rat neutrophil precursor cells

Previous studies from this laboratory have demonstrated importance of neutrophil-derived nitric oxide (NO) in free radical generation, characterized nitric oxide synthase (NOS) isoforms, and have reported subcellular distribution of NOS in rat peripheral neutrophils. Maximum number of neutrophils are added per day to the circulation from bone marrow, thus neutrophils might add substantial amount of NO in the bone marrow. NO generating ability and NOS isoforms characteristics in bone marrow neutrophil precursor cells is, however, still unexplored. This study was, therefore, undertaken to investigate NO generation ability and the molecular/biochemical characteristics of NOS isoforms in neutrophil precursor cells. The neutrophil precursors were separated on Percoll density gradient and characterized by Giemsa staining, CD markers, and by their size and granularity at various stages of maturation as Bands 1, 2, and 3. Mature neutrophils were efficient in free radical generation and phagocytosis, whereas immature cells had more mitochondria and myeloperoxidase. Amount of NO augmented from immature to mature neutrophils as assessed by fluorescent probe DAF-2DA and Griess reagent. Measurement of NOS enzyme activity further confirmed the functional status of NOS in these cells. NOS isoforms were differentially expressed during neutrophil maturation as confirmed by enzyme activity, Western blotting, flowcytometry, and RT-PCR. Expression of nNOS was predominantly stable in all the stages of neutrophil maturation. iNOS expression was, however, consistently augmented during maturation, whereas eNOS expression was downregulated with neutrophil maturation. Furthermore, all NOS isoforms proteins were distributed in cytosol as well as nucleus as assessed by confocal microscopy. This study for the first time report biochemical and molecular characteristics of NOS isoforms in rat neutrophil precursor cells.

Activation of cannabinoid 2 receptors protects against cerebral ischemia by inhibiting neutrophil recruitment

Activation of the cannabinoid 2 receptor (CB(2)) reduces ischemic injury in several organs. However, the mechanisms underlying this protective action are unclear. In a mouse model of ischemic stroke, we show that the CB(2) agonist JWH-133 (1 mg . kg(-1) . d(-1)) decreases the infarct size measured 3 d after onset of ischemia. The neuroprotective effect of JWH-133 was lost in CB(2)-deficient mice, confirming the specificity of JWH-133. Analysis of bone marrow chimeric mice revealed that bone marrow-derived cells mediate the CB(2) effect on ischemic brain injury. CB(2) activation reduced the number of neutrophils in the ischemic brain as shown by FACS analysis and by measuring the levels of the neutrophil marker enzyme myeloperoxidase. Indeed, we found in vitro that CB(2) activation inhibits adherence of neutrophils to brain endothelial cells. JWH-133 (1 microM) also interfered with the migration of neutrophils induced by the endogenous chemokine CXCL2 (30 ng/ml) through activation of the MAP kinase p38. This effect on neutrophils is likely responsible for the neuroprotection mediated by JWH-133 because JWH-133 was no longer protective when neutrophils were depleted. In conclusion, our data demonstrate that by activating p38 in neutrophils, CB(2) agonists inhibit neutrophil recruitment to the brain and protect against ischemic brain injury.-Murikinati, S., Jüttler, E., Keinert, T., Ridder, D. A., Muhammad, S., Waibler, Z., Ledent, C., Zimmer, A., Kalinke, U., Schwaninger, M. Activation of cannabinoid 2 receptors protects against cerebral ischemia by inhibiting neutrophil recruitment.

Aging enhances susceptibility to cigarette smoke-induced inflammation through bronchiolar chemokines

Cigarette smoking and aging are major risk factors for chronic obstructive pulmonary disease. An unsolved question is whether elderly lungs are particularly vulnerable to cigarette smoke (CS) exposure. In this study, we used a mouse model to test the hypothesis that aging increases the susceptibility to CS-induced pulmonary inflammation. We subjected 9-week-old and 69-week-old C57BL/6J mice to CS (whole-body exposure, 90 min/d), and evaluated neutrophil infiltration in the lungs, the levels of keratinocyte-derived chemokine (KC) and macrophage inflammatory protein (MIP)-2 in bronchoalveolar lavage fluid, and mRNA expression in bronchiolar epithelium retrieved by laser capture microdissection. The 69-week-old mice showed a greater number of neutrophils and higher levels of bronchiolar KC and MIP-2 expression than 9-week-old mice after 9 days of CS exposure. Furthermore, single CS exposure induced the rapid up-regulation of KC and MIP-2 in bronchiolar epithelium in both 9-week-old and 69-week-old mice, and the much higher levels in 69-week-old mice were associated with greater nuclear translocation of NF-kappaB. In contrast, no age-related differences were observed in the bronchiolar expression of NF-E2-related factor 2-regulated antioxidant and detoxification genes, heme oxygenase-1, reduced nicotinamide adenine dinucleotide phosphate quinone reductase 1, and glutamate-cysteine ligase, modifier unit, or antioxidant activity in bronchoalveolar lavage fluid, regardless of CS exposure. In summary, aging increases susceptibility to CS-induced inflammation in a mouse model, and robust mRNA up-regulation and nuclear translocation of NF-kappaB in bronchiolar epithelium may be involved.

Amelioration of pulmonary dysfunction and neutrophilic inflammation by PPAR gamma agonist in LPS-exposed guinea pigs

Airway dysfunction and pulmonary neutrophilic inflammation are the major characteristics of inflammatory conditions of lungs like chronic obstructive pulmonary disease (COPD). Lipopolysaccharide (LPS), a constituent of cigarette smoke, has been identified as the most important risk factor for COPD development. Inhalation exposure to LPS or cigarette smoke elicits an inflammatory response accompanied by airway hyperresponsiveness, elevated proinflammatory mediators and inflammatory cells similar to COPD. In the present study, we have evaluated the effects of pioglitazone, a peroxisome proliferator-activated receptor gamma (PPAR gamma) agonist, in LPS-induced pulmonary dysfunction, inflammatory changes and oxidative stress in guinea pigs. Inhalation exposure to nebulised LPS (30 microg ml(-1)) resulted in significant increase in the breathing frequency and bronchoconstriction accompanied with a significant decrease in tidal volume. Our results demonstrated that the LPS-induced pulmonary dysfunction was temporally associated with neutrophil infiltration as evident from heavy neutrophilia, increased TNFalpha in bronchoalveolar lavage fluid (BAL), elevated myeloperoxidase (MPO) level and histology of the lung tissue. Exposure to LPS also produced significant increase in tissue malondialdehyde (MDA) level indicating underlying oxidative stress. The results also reveal that pioglitazone (3, 10 and 30 mg kg(-1), p.o.) is effective in abrogating the pulmonary dysfunction by attenuating neutrophilia, TNFalpha release and oxidative stress in LPS-induced model of acute lung inflammation. Results from the present study have added to the emergent body of evidence that PPAR gamma agonists are effective in the therapy of inflammatory disease of the lungs.

A2B adenosine receptor signaling attenuates acute lung injury by enhancing alveolar fluid clearance in mice

Although acute lung injury contributes significantly to critical illness, resolution often occurs spontaneously via activation of incompletely understood pathways. We recently found that mechanical ventilation of mice increases the level of pulmonary adenosine, and that mice deficient for extracellular adenosine generation show increased pulmonary edema and inflammation after ventilator-induced lung injury (VILI). Here, we profiled the response to VILI in mice with genetic deletions of each of the 4 adenosine receptors (ARs) and found that deletion of the A2BAR gene was specifically associated with reduced survival time and increased pulmonary albumin leakage after injury. In WT mice, treatment with an A2BAR-selective antagonist resulted in enhanced pulmonary inflammation, edema, and attenuated gas exchange, while an A2BAR agonist attenuated VILI. In bone marrow-chimeric A2BAR mice, although the pulmonary inflammatory response involved A2BAR signaling from bone marrow-derived cells, A2BARs located on the lung tissue attenuated VILI-induced albumin leakage and pulmonary edema. Furthermore, measurement of alveolar fluid clearance (AFC) demonstrated that A2BAR signaling enhanced amiloride-sensitive fluid transport and elevation of pulmonary cAMP levels following VILI, suggesting that A2BAR agonist treatment protects by drying out the lungs. Similar enhancement of pulmonary cAMP and AFC were also observed after beta-adrenergic stimulation, a pathway known to promote AFC. Taken together, these studies reveal a role for A2BAR signaling in attenuating VILI and implicate this receptor as a potential therapeutic target during acute lung injury.

Phagocyte migration and cellular stress induced in liver, lung, and intestine during sleep loss and sleep recovery

Sleep is understood to possess recuperative properties and, conversely, sleep loss is associated with disease and shortened life span. Despite these critical attributes, the mechanisms and functions by which sleep and sleep loss impact health still are speculative. One of the most consistent, if largely overlooked, signs of sleep loss in both humans and laboratory rats is a progressive increase in circulating phagocytic cells, mainly neutrophils. The destination, if any, of the increased circulating populations has been unknown and, therefore, its medical significance has been uncertain. The purpose of the present experiment was to determine the content and location of neutrophils in liver and lung tissue of sleep-deprived rats. These are two principal sites affected by neutrophil migration during systemic inflammatory illness. The content of neutrophils in the intestine also was determined. Sleep deprivation in rats was produced for 5 and 10 days by the Bergmann-Rechtschaffen disk method, which has been validated for its high selectivity under freely moving conditions and which was tolerated and accompanied by a deep negative energy balance. Comparison groups included basal conditions and 48 h of sleep recovery after 10 days of sleep loss. Myeloperoxidase (MPO), an enzyme constituent of neutrophils, was extracted from liver, lung, and intestinal tissues, and its activity was determined by spectrophotometry. Leukocytes were located in vasculature and interstitial spaces in the liver and the lung by immunohistochemistry. Heme oxygenase-1, also known as heat shock protein-32 and a marker of cellular stress, and corticosterone also were measured. The results indicate neutrophil migration into extravascular liver and lung tissue concurrent with cell stress and consistent with tissue injury or infection induced by sleep loss. Plasma corticosterone was unchanged. Recovery sleep was marked by increased lung heme oxygenase-1, increased intestinal MPO activity, and abnormally low corticosterone, suggesting ongoing reactive processes as a result of prior sleep deprivation.

Topical N-acetyl-S-farnesyl-L-cysteine inhibits mouse skin inflammation, and unlike dexamethasone, its effects are restricted to the application site

N-acetyl-S-farnesyl-L-cysteine (AFC), a modulator of G protein and G-protein coupled receptor signaling, inhibits neutrophil chemotaxis and other inflammatory responses in cell-based assays. Here, we show topical AFC inhibits in vivo acute inflammation induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and arachidonic acid using the mouse ear model of inflammation. AFC inhibits edema, as measured by ear weight, and also inhibits neutrophil infiltration as assayed by direct counting in histological sections and by measuring myeloperoxidase (MPO) activity as a neutrophil marker. In addition, AFC inhibits in vivo allergic contact dermatitis in a mouse model utilizing sensitization followed by a subsequent challenge with 2,4-dinitrofluorobenzene. Unlike the established anti-inflammatories dexamethasone and indomethacin, AFC's action was restricted to the site of application. In this mouse model, both dexamethasone and indomethacin inhibited TPA-induced edema and MPO activity in the vehicle-treated, contralateral ear. AFC showed no contralateral ear inhibition for either of these end points. A marginally significant decrease due to AFC treatment was seen in TPA-induced epidermal hyperplasia at 24 hours. This was much less than the 90% inhibition of neutrophil infiltration, suggesting that AFC does not act by directly inhibiting protein kinase C.

Experimental gastritis in mice enhances anxiety in a gender-related manner

There is a gender-related comorbidity of pain-related and inflammatory bowel diseases with psychiatric diseases. Since the impact of experimental gastrointestinal inflammation on the emotional-affective behavior is little known, we examined whether experimental gastritis modifies anxiety, stress coping and circulating corticosterone in male and female Him:OF1 mice. Gastritis was induced by adding iodoacetamide (0.1%) to the drinking water for at least 7 days. Inflammation was assessed by gastric histology and myeloperoxidase activity, circulating corticosterone determined by enzyme immunoassay, anxiety-related behavior evaluated with the elevated plus maze and stress-induced hyperthermia tests, and depression-like behavior estimated with the tail suspension test. Iodoacetamide-induced gastritis was associated with gastric mucosal surface damage and an increase in gastric myeloperoxidase activity, this increase being significantly larger in female mice than in male mice. The rectal temperature of male mice treated with iodoacetamide was enhanced, whereas that of female mice was diminished. The circulating levels of corticosterone were reduced by 65% in female mice treated with iodoacetamide but did not significantly change in male mice. On the behavioral level, iodoacetamide treatment caused a decrease in nocturnal home-cage activity, drinking and feeding. While depression-related behavior remained unaltered following induction of gastritis, behavioral indices of anxiety were significantly enhanced in female but not male mice. There was no correlation between the estrous cycle and anxiety as well as circulating corticosterone. Radiotracer experiments revealed that iodoacetamide did not readily enter the brain, the blood-brain ratio being 20:1. Collectively, these data show that iodoacetamide treatment causes gastritis in a gender-related manner, its severity being significantly greater in female than in male mice. The induction of gastritis in female mice is associated with a reduction of circulating corticosterone and an enforcement of behavioral indices of anxiety. Gastric inflammation thus has a distinct gender-dependent influence on emotional-affective behavior and its neuroendocrine control.

Identification of ectonucleotidases CD39 and CD73 in innate protection during acute lung injury

Acute lung injury (ALI), such as that which occurs with mechanical ventilation, contributes to morbidity and mortality of critical illness. Nonetheless, in many instances, ALI resolves spontaneously through unknown mechanisms. Therefore, we hypothesized the presence of innate adaptive pathways to protect the lungs during mechanical ventilation. In this study, we used ventilator-induced lung injury as a model to identify endogenous mechanisms of lung protection. Initial in vitro studies revealed that supernatants from stretch-induced injury contained a stable factor which diminished endothelial leakage. This factor was subsequently identified as adenosine. Additional studies in vivo revealed prominent increases in pulmonary adenosine levels with mechanical ventilation. Because ectoapyrase (CD39) and ecto-5'-nucleotidase (CD73) are rate limiting for extracellular adenosine generation, we examined their contribution to ALI. In fact, both pulmonary CD39 and CD73 are induced by mechanical ventilation. Moreover, we observed pressure- and time-dependent increases in pulmonary edema and inflammation in ventilated cd39(-/-) mice. Similarly, pharmacological inhibition or targeted gene deletion of cd73 was associated with increased symptom severity of ventilator-induced ALI. Reconstitution of cd39(-/-) or cd73(-/-) mice with soluble apyrase or 5'-nucleotidase, respectively, reversed such increases. In addition, ALI was significantly attenuated and survival improved after i.p. treatment of wild-type mice with soluble apyrase or 5'-nucleotidase. Taken together, these data reveal a previously unrecognized role for CD39 and CD73 in lung protection and suggest treatment with their soluble compounds as a therapeutic strategy for noninfectious ALI.

Deletion of the acid-sensing ion channel ASIC3 prevents gastritis-induced acid hyperresponsiveness of the stomach-brainstem axis

Gastric acid challenge of the rat and mouse stomach is signalled to the brainstem as revealed by expression of c-Fos. The molecular sensors relevant to the detection of gastric mucosal acidosis are not known. Since the acid-sensing ion channels ASIC2 and ASIC3 are expressed by primary afferent neurons, we examined whether knockout of the ASIC2 or ASIC3 gene modifies afferent signalling of a gastric acid insult in the normal and inflamed stomach. The stomach of conscious mice (C57BL/6) was challenged with intragastric HCl; two hours later the activation of neurons in the nucleus tractus solitarii (NTS) of the brainstem was visualized by c-Fos immunocytochemistry. Mild gastritis was induced by addition of iodoacetamide (0.1%) to the drinking water for 7 days. Exposure of the gastric mucosa to HCl (0.25M) caused a 3-fold increase in the number of c-Fos-positive neurons in the NTS. This afferent input to the NTS remained unchanged by ASIC3 knockout, whereas ASIC2 knockout augmented the c-Fos response to gastric HCl challenge by 33% (P<0.01). Pretreatment of wild-type mice with iodoacetamide induced mild gastritis, as revealed by increased myeloperoxidase activity, and enhanced the number of NTS neurons responding to gastric HCl challenge by 41% (P<0.01). This gastric acid hyperresponsiveness was absent in ASIC3 knockout mice but fully preserved in ASIC2 knockout mice. The current data indicate that ASIC3 plays a major role in the acid hyperresponsiveness associated with experimental gastritis. In contrast, ASIC2 appears to dampen acid-evoked input from the stomach to the NTS.

Absorption and metabolism of albendazole after intestinal ischemia/reperfusion

Pathophysiological processes involving inflammatory response may affect absorption and biotransformation of some drugs, modifying their pharmacokinetic behaviour. Ischemia/reperfusion (I/R) injury has been used as a model for inflammatory processes. The aim of this work was to study the effect of intestinal I/R injury on the absorption and metabolism processes of one orally administered drug, albendazole that is anthelmintic drug, it undergoes intestinal bioconversion into albendazole sulfoxide by two enzymatic systems, cytochromes P450 (CYP450) and flavin-containing monooxygenase (FMO). Male Wistar rats were used to study the influence of I/R in the intestinal absorption and metabolism of albendazole, after 60 min of mesenteric occlusion and 30 min of reperfusion. The intestinal studies were performed in microsomal, and everted ring incubations. During in situ studies, the I/R group had faster disappearance of albendazole from the lumen. In addition, albendazole only appeared in blood samples of the I/R group, while albendazole sulfoxide appeared in both samples and was higher in the control group. These findings are supported by significant reductions of albendazole sulfoxide formation in intestinal everted ring assays and in microsomal incubations after the I/R process. Both metabolizing systems, CYP4503A and FMO, were affected by I/R. Our data indicate that I/R injury, considered as an inflammatory model, reduces absorption and metabolism processes of albendazole.