Gold Nanoparticles Inhibit Steroid-Insensitive Asthma in Mice Preserving Histone Deacetylase 2 and NRF2 Pathways.

BACKGROUND: Gold nanoparticles (AuNPs) can inhibit pivotal pathological changes in experimental asthma, but their effect on steroid-insensitive asthma is unclear. The current study assessed the effectiveness of nebulized AuNPs in a murine model of glucocorticoid (GC)-resistant asthma. METHODS: A/J mice were sensitized and subjected to intranasal instillations of ovalbumin (OVA) once a week for nine weeks. Two weeks after starting allergen stimulations, mice were subjected to Budesonide or AuNP nebulization 1 h before stimuli. Analyses were carried out 24 h after the last provocation. RESULTS: We found that mice challenged with OVA had airway hyperreactivity, eosinophil, and neutrophil infiltrates in the lung, concomitantly with peribronchiolar fibrosis, mucus production, and pro-inflammatory cytokine generation compared to sham-challenged mice. These changes were inhibited in mice treated with AuNPs, but not Budesonide. In the GC-resistant asthmatic mice, oxidative stress was established, marked by a reduction in nuclear factor erythroid 2-related factor 2 (NRF2) levels and catalase activity, accompanied by elevated values of thiobarbituric acid reactive substances (TBARS), phosphoinositide 3-kinases δ (PI3Kδ) expression, as well as a reduction in the nuclear expression of histone deacetylase 2 (HDAC2) in the lung tissue, all of which sensitive to AuNPs but not Budesonide treatment. CONCLUSION: These findings suggest that AuNPs can improve GC-insensitive asthma by preserving HDAC2 and NRF2.

15-Deoxy-Delta-12,14-Prostaglandin J2 Inhibits Lung Inflammation and Remodeling in Distinct Murine Models of Asthma.

15-deoxy-Δ-12,14-prostaglandin J2 (15d-PGJ2) has been described as an anti-inflammatory lipid mediator in several in vitro and in vivo studies, but its effect on allergic pulmonary inflammation remains elusive. The aim of this study was to investigate the therapeutic potential of 15d-PGJ2 based on distinct murine models of allergic asthma triggered by either ovalbumin (OVA) or house dust mite extract (HDM). Characteristics of lung inflammation, airway hyper-reactivity (AHR), mucus exacerbation, and lung remodeling in sensitized A/J mice treated or not with 15d-PGJ2 were assessed. 15d-PGJ2 treatments were carried out systemically or topically given via subcutaneous injection or intranasal instillation, respectively. Analyses were carried out 24 h after the last allergen provocation. Irrespective of the route of administration, 15d-PGJ2 significantly inhibited the peribronchial accumulation of eosinophils and neutrophils, subepithelial fibrosis and also mucus exacerbation caused by either OVA or HDM challenge. The protective effect of 15d-PGJ2 occurred in parallel with inhibition of allergen-induced AHR and lung tissue production of pro-inflammatory cytokines, such as interleukin (IL)-5, IL-13, IL-17, and TNF-α. Finally, 15d-PGJ2 was found effective in inhibiting NF-κB phosphorylation upon HDM challenge as measured by Western blotting. In conclusion, our findings suggest that 15d-PGJ2 can reduce crucial features of asthma, including AHR, lung inflammation, and remodeling in distinct murine models of the disease. These effects are associated with a decrease in lung tissue generation of pro-inflammatory cytokines by a mechanism related to downregulation of NF-κB phosphorylation.

Effectiveness of Cissampelos sympodialis and its isolated alkaloid warifteine in airway hyperreactivity and lung remodeling in a mouse model of asthma.

BACKGROUND: Cissampelos sympodialis Eichl. (Menispermaceae) is a plant found in Northeastern and Southeast of Brazil and hot water infusion of C. sympodialis root bark is largely used in the indigenous and folk medicine to treat several inflammatory disorders, including asthma. Asthma is a chronic inflammatory allergic disease characterized by airway hyperreactivity (AHR), eosinophil tissue infiltration and lung remodeling. The aim of this study was to evaluate the therapeutic effect of C. sympodialis and its isolated alkaloid warifteine on allergen triggered airway hyperreactivity (AHR) and lung remodeling in murine model of asthma. METHODOLOGY/PRINCIPAL FINDINGS: The oral pre-treatment with C. sympodialis or warifteine inhibited allergen-induced AHR to inhaled methacholine and IL-13 levels in the bronchoalveolar lavage (BAL). In order to investigate the therapeutic potential of C. sympodialis and warifteine, animals were treated 1h after the last ovalbumin (OVA) challenge in sensitized animals. Similarly to the pre-treatment, post-treatment with warifteine was effective to inhibit significantly AHR to inhaled methacholine and to reduce IL-13 levels in the BAL. In addition, oral pre- or post-treatments with C. sympodialis or warifteine reduced OVA-induced eosinophil tissue infiltration, mucus production and subepithelial fibrosis to values similar to nonallergic controls. CONCLUSIONS: Our data show the anti-allergic and immunoregulatory properties of C. sympodialis, acting mostly through the active compound warifteine, to inhibit the airway hyperreactivity and lung remodeling through a mechanism at least partially dependent of IL-13 and eosinophil inhibition. Therefore placing warifteine as an interesting therapeutic candidate in allergic inflammation and corroborating the folk medicine use of C. sympodialis as anti-allergic plant.

7-Epiclusianone, a tetraprenylated benzophenone, relaxes airway smooth muscle through activation of the nitric oxide-cGMP pathway.

This study was undertaken to investigate the putative mechanism(s) underlying the antispasmodic effect of 7-epiclusianone, a naturally occurring compound isolated from the plant Garcinia brasiliensis. Guinea pig tracheal rings were mounted in tissue baths filled with Krebs' solution, and the contractile response to distinct stimuli was measured in the presence or absence of 7-epiclusianone. We also tested the effect of 7-epiclusianone on methacholine-evoked airways obstruction in BALB/c mice using barometric plethysmography. 7-Epiclusianone (10 microM) inhibited epithelium-intact tracheal ring contraction induced by allergen, histamine, 5-hydroxytryptamine, or carbachol challenge. The relaxation effect was abrogated by epithelium removal, the presence of nitric-oxide synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) (100 microM), or soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) (10 microM). 7-Epiclusianone (1-100 microM) induced a dose-dependent increase in the intracellular cGMP levels of cultured tracheal rings. The relaxation effect of 7-epiclusianone was also inhibited by K(+) channel blockers tetraethylammonium (10 microM), glibenclamide (1 microM), or apamin (1 microM), but not by 9-(tetrahydro-2'-furyl)adenine (SQ22,536) (100 microM), an adenylate cyclase inhibitor. In epithelium-intact tracheal rings, 7-epiclusianone also inhibited Ca(2+)-induced contractions in K(+) (60 mM)-depolarized preparations, but it seemed ineffective in assays in which epithelium-denuded tracheal ring preparations were used. Oral administration of 7-epiclusinone (25-100 mg/kg) dose-dependently inhibited airway obstruction triggered by aerosolized methacholine (6-25 mg/ml), in a mechanism sensitive to L-NAME (20 mg/kg). In conclusion, the relaxation effect of 7-epiclusinone seems to be mediated by epithelium-, nitric oxide-, and cGMP-dependent mechanisms. Furthermore, oral administration of 7-epiclusianone reduces episodes of bronchial obstruction, warranting further research on this compound regarding a putative application in asthma therapy.

Contribution of mast cells and snake venom metalloproteinases to the hyperalgesia induced by Bothrops jararaca venom in rats.

Bothrops jararaca venom (Bjv) is known to induce local inflammation and severe pain. Since, mast cells are able to secrete mediators involved in algesic processes, in this study we examined the putative role of these cells in the hyperalgesia triggered by Bjv in the rat paw. We noted that treatment with mast cell stabilizer sodium cromoglicate as well as with histamine and 5-hydroxytriptamine receptor antagonists meclizine and methysergide, respectively, inhibited the Bjv-induced hyperalgesia. In addition, we showed that stimulation of isolated rat peritoneal mast cells with Bjv in vitro resulted in the release of stored and neo-generated inflammatory mediators such as histamine and leukotriene C(4), respectively. Bjv-induced histamine secretion was clearly sensitive to treatment with sodium cromoglicate and sodium nedocromil. We further observed that metalloproteinase inhibitors 1,10-phenantroline and DM43 inhibited mast cell degranulation in vitro, under conditions where inhibitors of phospholipase A(2) as well as of serine- and cysteine-proteinases were inactive. Altogether, our findings indicate that mast cells seem to contribute to the hyperalgesia caused by Bjv in the rat paw, and also provide evidence that this response might be dependent on the ability of the Bjv to activate directly mast cells.

Maus-tratos contra crianças e adolescentes: avaliação das notificações compulsórias no município de São José do Rio Preto / Mistreating children and adolescents: an evaluation of compulsory notifications in the city of São José do Rio Preto – São Paulo

Busca-se, neste trabalho, identificar os tipos de maus-tratos, vítimas, agressores e local de proveniência em notificações de maus-tratos, por meio de estudo retrospectivo de 560 casos de suspeita ou confirmação de maus-tratos contra crianças e adolescentes. O estudo foi realizado a partir da análise das Fichas de Notificação Compulsória encaminhadas à Secretaria Municipal de Saúde de São José do Rio Preto, Estado de São Paulo, no período de maio de 2002 a setembro de 2005. Foram identificados 445 (80%) casos de violência isolada e 115 (20%) de violência associada. A negligência foi o tipo mais freqüente de maus-tratos e as vítimas, de ambos os sexos, com idade abaixo de 9 anos completos. A mãe foi o principal agressor e o Serviço de Emergência de Pediatria do Hospital de Base com n = 204 (28%) apresentou o maior número de notificações.

Long-term exacerbation by interleukin 13 of IgE-mediated eosinophilia in rats.

Recent work shows that at least two cycles of antigen challenge applied in a 7-day interval are required to yield tissue eosinophil accumulation in IgE-passively sensitized rats. Since interleukin (IL)-13 is widely regarded as a key mediator in eosinophilic responses associated with mast cells and IgE, we investigated whether this cytokine could replace the first cycle of sensitization and challenge in its proeosinophilic role. We found that IL-13 (25 and 50 ng/cavity) injected into the rat pleural space led to eotaxin generation and a dose-dependent accumulation of eosinophils following IgE-passive sensitization and challenge 7 days later. IL-13 failed to cause eosinophil chemotaxis in vitro but induced eosinophil accumulation into the pleural cavity of naïve rats, which peaked 1 day and faded 72 h post-challenge. No changes were found 1 week after intrapleural injection of IL-13, except an approximately 40-50% increase in the number of adhered and non-adhered pleural mast cells. As recovered from the pleural effluent 1 week after IL-13, mast cells expressed the same amount of IgE bound on their surface as compared to controls. However, they generated 3-fold more LTC(4) following IgE-sensitization and challenge in vitro, keeping intact the amount of histamine released. Finally, pretreatment with zileuton (50 microg/cavity) 1 h before allergen challenge prevented eosinophil accumulation in those animals injected with IL-13 1 week before. In conclusion, our findings show that IL-13 causes a long-term exacerbation of the IgE-mediated eosinophilic response in a mechanism associated with heightened cysteinyl-leukotriene (cys-LT) production by resident mast cells.

Soluble factors released by Toxoplasma gondii-infected astrocytes down-modulate nitric oxide production by gamma interferon-activated microglia and prevent neuronal degeneration.

The maintenance of a benign chronic Toxoplasma gondii infection is mainly dependent on the persistent presence of gamma interferon (IFN-gamma) in the central nervous system (CNS). However, IFN-gamma-activated microglia are paradoxically involved in parasitism control and in tissue damage during a broad range of CNS pathologies. In this way, nitric oxide (NO), the main toxic metabolite produced by IFN-gamma-activated microglia, may cause neuronal injury during T. gondii infection. Despite the potential NO toxicity, neurodegeneration is not a common finding during chronic T. gondii infection. In this work, we describe a significant down-modulation of NO production by IFN-gamma-activated microglia in the presence of conditioned medium of T. gondii-infected astrocytes (CMi). The inhibition of NO production was paralleled with recovery of neurite outgrowth when neurons were cocultured with IFN-gamma-activated microglia in the presence of CMi. Moreover, the modulation of NO secretion and the neuroprotective effect were shown to be dependent on prostaglandin E(2) (PGE(2)) production by T. gondii-infected astrocytes and autocrine secretion of interleukin-10 (IL-10) by microglia. These events were partially eliminated when infected astrocytes were treated with aspirin and cocultures were treated with anti-IL-10 neutralizing antibodies and RP-8-Br cyclic AMP (cAMP), a protein kinase A inhibitor. Further, the modulatory effects of CMi were mimicked by the presence of exogenous PGE(2) and by forskolin, an adenylate cyclase activator. Altogether, these data point to a T. gondii-triggered regulatory mechanism involving PGE(2) secretion by astrocytes and cAMP-dependent IL-10 secretion by microglia. This may reduce host tissue inflammation, thus avoiding neuron damage during an established Th1 protective immune response.

Effect of selective phosphodiesterase inhibitors on the rat eosinophil chemotactic response in vitro

In the present study, we have performed a comparative analysis of the effect of selective inhibitors of phosphodiesterase (PDE) type III, IV and V on eosinophil chemotaxis triggered by platelet activating factor (PAF) and leukotriene B4 (LTB4) in vitro. The effect of the analogues N6-2'-O-dibutyryladenosine 3':5' cyclic monophosphate (Bt2 cyclic AMP) and N2-2'-O-dibutyrylguanosine 3':5' cyclic monophosphate (Bt2 cyclic GMP) has also been determined. The eosinophils were obtained from the peritoneal cavity of naive Wistar rats and purified in discontinuous Percoll gradients to 85-95 per cent purity. We observed that pre-incubation of eosinophils with the PDE type IV inhibitor rolipram suppressed the chemotactic response triggered by PAF and LTB4 in association with an increase in the intracellular levels of cyclic AMP. In contrast, neither zaprinast (type V inhibitor) nor type III inhibitors milrinone and SK&F 94836 affected the eosinophil migration. Only at the highest concentration tested did the analogue Bt2 cyclic AMP suppress the eosinophil chemotaxis, under conditions where Bt2 cyclic GMP was ineffective. We have concluded that inhibition of PDE IV, but not PDE III or V, was able to block the eosinophil chemotaxis in vitro, suggesting that the suppresive activity of selective PDE IV inhibitors on tissue eosinophil accumulation may, at least, be partially dependent on their ability to directly inhibit the eosinophil migration.