Potential role for ET-2 acting through ETA receptors in experimental colitis in mice.

OBJECTIVE AND DESIGN: This study attempted to clarify the roles of endothelins and mechanisms associated with ETA/ETB receptors in mouse models of colitis. MATERIALS AND METHODS: Colitis was induced by intracolonic administration of 2,4,6-trinitrobenzene sulfonic acid (TNBS, 1.5 mg/animal) or dextran sulfate sodium (DSS, 3%). After colitis establishment, mice received Atrasentan (ETA receptor antagonist, 10 mg/kg), A-192621 (ETB receptor antagonist, 20 mg/kg) or Dexamethasone (1 mg/kg) and several inflammatory parameters were assessed, as well as mRNA levels for ET-1, ET-2 and ET receptors. RESULTS: Atrasentan treatment ameliorates TNBS- and DSS-induced colitis. In the TNBS model was observed reduction in macroscopic and microscopic score, colon weight, neutrophil influx, IL-1ß, MIP-2 and keratinocyte chemoattractant (KC) levels, inhibition of adhesion molecules expression and restoration of IL-10 levels. However, A192621 treatment did not modify any parameter. ET-1 and ET-2 mRNA was decreased 24 h, but ET-2 mRNA was markedly increased at 48 h after TNBS. ET-2 was able to potentiate LPS-induced KC production in vitro. ETA and ETB receptors mRNA were increased at 24, 48 and 72 h after colitis induction. CONCLUSIONS: Atrasentan treatment was effective in reducing the severity of colitis in DSS- and TNBS-treated mice, suggesting that ETA receptors might be a potential target for inflammatory bowel diseases.

Inhaled beclomethasone in pregnant asthmatic women--a systematic review.

The aim of this study was to systematically review the safety and efficacy of inhaled beclomethasone for asthma treatment in pregnant women. We performed a systematic review in Medline, LILACS and SciELO electronic databases in December 2012. A total of 3433 articles were found by using the keywords asthma, pregnancy and beclomethasone. Among these, 1666 were from Medline, via PubMed, and 1767 were from LILACS and SciELO. Nine of these articles were selected. Only one paper suggested an increased foetal risk for congenital malformations, and one other for offspring endocrine and metabolic disturbances. Data are mostly reassuring, supporting the use of glucocorticoid inhalants during pregnancy, and we found no evidence of inferiority in relation to efficacy and safety of beclomethasone compared to other drugs used in pregnant asthmatic women.

Inhibitor of PI3Kγ ameliorates TNBS-induced colitis in mice by affecting the functional activity of CD4+CD25+FoxP3+ regulatory T cells.

BACKGROUND AND PURPOSE: Phosphoinositide 3-kinase-γ (PI3Kγ) is implicated in many pathophysiological conditions, and recent evidence has suggested its involvement in colitis. In the present study, we investigated the effects of AS605240, a relatively selective PI3Kγ inhibitor, in experimental colitis and its underlying mechanisms. EXPERIMENTAL APPROACH: Acute colitis was induced in mice by treatment with trinitrobenzene sulphonic acid (TNBS), and the effect of AS605240 on colonic injury was assessed. Pro-inflammatory mediators and cytokines were measured by immunohistochemistry, elisa, real time-polymerase chain reaction and flow cytometry. KEY RESULTS: Oral administration of AS605240 significantly attenuated TNBS-induced acute colitis and diminished the expression of matrix metalloproteinase-9 and vascular endothelial growth factor. The colonic levels and expression of IL-1ß, CXCL-1/KC, MIP-2 and TNF-α were also reduced following therapeutic treatment with AS605240. Moreover, AS605240 reduced MIP-2 levels in a culture of neutrophils stimulated with lipopolysaccharide. The mechanisms underlying these actions of AS605240 are related to nuclear factor-κ (NF-κB) inhibition. Importantly, the PI3Kγ inhibitor also up-regulated IL-10, CD25 and FoxP3 expression. In addition, a significant increase in CD25 and FoxP3 expression was found in isolated lamina propria CD4+ T cells of AS605240-treated mice. The effect of AS605240 on Treg induction was further confirmed by showing that concomitant in vivo blockade of IL-10R significantly attenuated its therapeutic activity. CONCLUSIONS AND IMPLICATIONS: These results suggest that AS605240 protects mice against TNBS-induced colitis by inhibiting multiple inflammatory components through the NF-κB pathway while simultaneously inducing an increase in the functional activity of CD4+CD25+ Treg. Thus, AS605240 may offer a promising new therapeutic strategy for the treatment of inflammatory bowel diseases.

The relevance of kinin B1 receptor upregulation in a mouse model of colitis.

BACKGROUND AND PURPOSE: Kinins are implicated in many pathophysiological conditions, and recent evidence has suggested their involvement in colitis. This study assessed the role of the kinin B1 receptors in a mouse model of colitis. EXPERIMENTAL APPROACH: Colitis was induced in mice by 2,4,6-trinitrobenzene sulphonic acid (TNBS), and tissue damage and myeloperoxidase activity were assessed. B1 receptor induction was analysed by organ bath studies, binding assay and reverse transcription PCR. KEY RESULTS: TNBS-induced colitis was associated with tissue damage, neutrophil infiltration and time-dependent increase of colon B1 receptor-mediated contraction, with the maximal response observed at 72 h. The upregulation of the B1 receptor at this time point was also confirmed by means of binding studies. B1 receptor mRNA levels were elevated as early as 6 h after colitis induction and remained high for up to 48 h. TNBS-evoked tissue damage and neutrophil influx were reduced by the selective B1 receptor antagonist SSR240612, and in B1 receptor knockout mice. In vivo treatment with inhibitors of protein synthesis, nuclear factor-kappaB activation, inducible nitric oxide synthase (iNOS) or tumour necrosis factor alpha (TNFalpha) significantly reduced B1 receptor agonist-induced contraction. Similar results were observed in iNOS and TNF receptor 1-knockout mice. CONCLUSIONS AND IMPLICATIONS: These results provide convincing evidence on the role of B1 receptors in the pathogenesis of colitis. Therefore, the blockade of kinin B1 receptors might represent a new therapeutic option for treating inflammatory bowel diseases.

Mating activity of yellow and sepia Drosophila willistoni mutants.

By analyzing the mating activity of newly isolated yellow and sepia mutants of Drosophila willistoni no difference in behavior between sepia and wild-type flies were observed, whereas yellow males were less successful than wild-type males when competing for females. These results are in agreement with those reported for other Drosophila species. D. willistoni was different in the 'females-competing' crosses because wild-type males mated more frequently with wild-type females whereas yellow males mated successfully with both phenotypes. These results indicate the complexity of the courtship behavior in D. willistoni and provide data for comparative and evolutionary research into the genus.

Role of cholinergic and adrenergic pathways of the medial septal area in the control of water intake and renal excretion in rats.

In this study, we investigated an interaction between noradrenergic and cholinergic pathways of the medial septal area (MSA) on the control of water intake and urinary electrolyte excretion by means of injection of their respective agonists. Noradrenaline (a nonspecific alpha-adrenergic agonist) and clonidine (an alpha 2-adrenergic agonist), but not phenylephrine (an alpha 1-adrenergic agonist), induced natriuresis and kaliuresis. alpha-Adrenergic activation had no effect on the natriuresis and kaliuresis induced by carbachol (a cholinergic agonist) and it inhibited the antinatriuresis and antikaliuresis induced by isoproterenol (a beta-adrenergic agonist). Interactions related to volume excretion are complex, alpha-Adrenergic activation induced a mild diuresis and inhibited the antidiuresis induced by isoproterenol, but phenylephrine combined with carbachol induced antidiuresis. The water intake induced by carbachol was inhibited by clonidine and noradrenaline, but not phenylephrine. These results show an asymmetry in the interaction between alpha-adrenergic and cholinergic receptors concerning water intake and electrolyte excretion.