Phenotypes of regulatory T cells in different stages of COPD.

BACKGROUND: Previous studies have shown that failure to control inflammatory processes mediated by regulatory T (Treg) cells contributes to chronic obstructive pulmonary disease (COPD) development and progression. The activity of Treg cells depends on their phenotypic characteristics: resting Treg (rTreg, CD3+CD4+CD25+FOXP3+CD25++CD45RA+) and activated Treg (aTreg, CD3+CD4+CD25+FOXP3+CD25+++CD45RA-) cells exhibit immunosuppressive activity, while cytokine-secreting T cells (FrIII, CD3+CD4+CD25+FOXP3+CD25++CD45RA-) exhibit proinflammatory activity. Previous findings have shown an increased density of cytokine-secreting T cells in COPD patients experiencing exacerbation. However, the methods for evaluating COPD under stable conditions are lacking. AIM: To evaluate Treg cell phenotypes in patients with different stages of COPD under stable conditions. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from non-obstructed smokers and ex-smokers (NOS group, n = 19) and COPD patients at different stages (COPD I-II group, n = 25; COPD III-IV group, n = 25). The phenotypic characteristics of Treg cells and Th17 cells and their respective intracellular cytokines were analyzed by flow cytometry. RESULTS: Both obstructed groups showed an increase in the proportion of rTregs, while the COPD III-IV group showed additional increases in total Treg and Th17 cells and in IL-10+ cells. There was an increase in proinflammatory mediators (CD3+CD4+IL-17+ cells; CD3+CD4+RORγt+ cells) in the COPD I-II group. In contrast, the NOS group demonstrated high proportions of proinflammatory Treg cells and proinflammatory CD8+ T cells (CD3+CD8+IL-17+). CONCLUSION: Despite the increase in both total Treg cells and the rTreg phenotype from the early stages of COPD, there was a decrease in cells expressing IL-10, suggesting a failure in controlling the inflammatory process. These events precede the progression of the inflammatory process mediated by Th17 cells.

Creatine Supply Attenuates Ischemia-Reperfusion Injury in Lung Transplantation in Rats.

Ischemia-reperfusion injury (IRI) is one of the factors limiting the success of lung transplantation (LTx). IRI increases death risk after transplantation through innate immune system activation and inflammation induction. Some studies have shown that creatine (Cr) protects tissues from ischemic damage by its antioxidant action. We evaluated the effects of Cr supplementation on IRI after unilateral LTx in rats. Sixty-four rats were divided into four groups: water + 90 min of ischemia; Cr + 90 min of ischemia; water + 180 min of ischemia; and Cr + 180 min of ischemia. Donor animals received oral Cr supplementation (0.5 g/kg/day) or vehicle (water) for five days prior to LTx. The left lung was exposed to cold ischemia for 90 or 180 min, followed by reperfusion for 2 h. We evaluated the ventilatory mechanics and inflammatory responses of the graft. Cr-treated animals showed a significant decrease in exhaled nitric oxide levels and inflammatory cells in blood, bronchoalveolar lavage fluid and lung tissue. Moreover, edema, cell proliferation and apoptosis in lung parenchyma were reduced in Cr groups. Finally, TLR-4, IL-6 and CINC-1 levels were lower in Cr-treated animals. We concluded that Cr caused a significant decrease in the majority of inflammation parameters evaluated and had a protective effect on the IRI after LTx in rats.

Pre- and postnatal exposure of mice to concentrated urban PM2.5 decreases the number of alveoli and leads to altered lung function at an early stage of life.

Gestational exposure to air pollution is associated with negative outcomes in newborns and children. In a previous study, we demonstrated a synergistic negative effect of pre- and postnatal exposure to PM2.5 on lung development in mice. However, the means by which air pollution affects development of the lung have not yet been identified. In this study, we exposed pregnant BALB/c mice and their offspring to concentrated urban PM2.5 (from São Paulo, Brazil; target dose 600 µg/m3 for 1 h daily). Exposure was started on embryonic day 5.5 (E5.5, time of placental implantation). Lung tissue of fetuses and offspring was submitted to stereological and transcriptomic analyses at E14.5 (pseudoglandular stage of lung development), E18.5 (saccular stage) and P40 (postnatal day 40, alveolarized lung). Additionally, lung function and cellularity of bronchoalveolar lavage (BAL) fluid were studied in offspring animals at P40. Compared to control animals that were exposed to filtered air throughout gestation and postnatal life, PM-exposed mice exhibited higher lung elastance and a lower alveolar number at P40 whilst the total lung volume and cellularity of BAL fluid were not affected. Glandular and saccular structures of fetal lungs were not altered upon gestational exposure; transcriptomic signatures, however, showed changes related to DNA damage and its regulation, inflammation and regulation of cell proliferation. A differential expression was validated at E14.5 for the candidates Sox8, Angptl4 and Gas1. Our data substantiate the in utero biomolecular effect of gestational exposure to air pollution and provide first-time stereological evidence that pre- and early life-postnatal exposure compromise lung development, leading to a reduced number of alveoli and an impairment of lung function in the adult mouse.

A treatment with a protease inhibitor recombinant from the cattle tick (Rhipicephalus Boophilus microplus) ameliorates emphysema in mice.

AIMS: To determine whether a serine protease inhibitor treatment can prevent or minimize emphysema in mice. METHODS: C57BL/6 mice were subjected to porcine pancreatic elastase (PPE) nasal instillation to induce emphysema and were treated with a serine protease inhibitor (rBmTI-A) before (Protocol 1) and after (Protocol 2) emphysema development. In both protocols, we evaluated lung function to evaluate the airway resistance (Raw), tissue damping (Gtis) and tissue elastance (Htis). The inflammatory profile was analyzed in the bronchoalveolar lavage (BALF) and through the use of morphometry; we measured the mean linear intercept (Lm) (to verify alveolar enlargement), the volume proportion of collagen and elastic fibers, and the numbers of macrophages and metalloprotease 12 (MMP-12) positive cells in the parenchyma. We showed that at both time points, even after the emphysema was established, the rBmTI-A treatment was sufficient to reverse the loss of elastic recoil measured by Htis, the alveolar enlargement and the increase in the total number of cells in the BALF, with a primary decrease in the number of macrophages. Although, the treatment did not control the increase in macrophages in the lung parenchyma, it was sufficient to decrease the number of positive cells for MMP-12 and reduce the volume of collagen fibers, which was increased in PPE groups. These findings attest to the importance of MMP-12 in PPE-induced emphysema and suggest that this metalloprotease could be an effective therapeutic target.

Immunosuppression effects on airway mucociliary clearance: comparison between two triple therapies.

BACKGROUND: Tacrolimus and mycophenolate have now become the most widely used combination for maintenance immunosuppressive regimens after lung transplantation in comparison with cyclosporine and azathioprine. However, limited information is available with respect to their effects on cells, other than those from the immunologic compartment. We hypothesized that different triple therapies could have different effects on airway mucociliary clearance, playing an important role in respiratory infections observed after lung transplantation. METHODS: Ninety rats were assigned to three groups (n = 30 each): control = vehicle, therapy 1 = tacrolimus + mycophenolate + prednisone, and therapy 2 = cyclosporine + azathioprine + prednisone. After 7, 15, or 30 days of treatment by gavage, the animals were killed and the following parameters were studied: mucus transportability, ciliary beating frequency, mucociliary transport velocity, and neutral and acid mucus production. RESULTS: There was a significant decrease in ciliary beating frequency, mucociliary transport velocity, and neutral mucus production in all immunosuppressed animals; indeed, both therapies, mainly therapy 1, caused an increase in acid mucus production for as long as 15 days of treatment. CONCLUSIONS: Both triple therapies impaired airway mucociliary clearance of rats, but therapy 1 had a more deleterious effect. These data suggest that these undesirable effects can contribute to the high incidence of respiratory infections observed in patients undergoing lung transplantation.

Cigarette smoke dissociates inflammation and lung remodeling in OVA-sensitized and challenged mice.

We evaluated the effects of cigarette smoke (CS) on lung inflammation and remodeling in a model of ovalbumin (OVA)-sensitized and OVA-challenged mice. Male BALB/c mice were divided into 4 groups: non-sensitized and air-exposed (control); non-sensitized and exposed to cigarette smoke (CS), sensitized and air-exposed (OVA) (50 µg+OVA 1% 3 times/week for 3 weeks) and sensitized and cigarette smoke exposed mice (OVA+CS). IgE levels were not affected by CS exposure. The increases in total bronchoalveolar fluid cells in the OVA group were attenuated by co-exposure to CS, as were the changes in IL-4, IL-5, and eotaxin levels as well as tissue elastance (p<0.05). In contrast, only the OVA+CS group showed a significant increase in the protein expression of IFN-γ, VEGF, GM-CSF and collagen fiber content (p<0.05). In our study, exposure to cigarette smoke in OVA-challenged mice resulted in an attenuation of pulmonary inflammation but led to an increase in pulmonary remodeling and resulted in the dissociation of airway inflammation from lung remodeling.

Non-asthmatic patients show increased exhaled nitric oxide concentrations.

OBJECTIVE: Evaluate whether exhaled nitric oxide may serve as a marker of intraoperative bronchospasm. INTRODUCTION: Intraoperative bronchospasm remains a challenging event during anesthesia. Previous studies in asthmatic patients suggest that exhaled nitric oxide may represent a noninvasive measure of airway inflammation. METHODS: A total of 146,358 anesthesia information forms, which were received during the period from 1999 to 2004, were reviewed. Bronchospasm was registered on 863 forms. From those, three groups were identified: 9 non-asthmatic patients (Bronchospasm group), 12 asthmatics (Asthma group) and 10 subjects with no previous airway disease or symptoms (Control group). All subjects were submitted to exhaled nitric oxide measurements (parts/billion), spirometry and the induced sputum test. The data was compared by ANOVA followed by the Tukey test and Kruskal-Wallis followed by Dunn's test. RESULTS: The normal lung function test results for the Bronchospasm group were different from those of the asthma group (p <0.05). The median percentage of eosinophils in induced sputum was higher for the Asthma [2.46 (0.45-6.83)] compared with either the Bronchospasm [0.55 (0-1.26)] or the Control group [0.0 (0)] (p <0.05); exhaled nitric oxide followed a similar pattern for the Asthma [81.55 (57.6-86.85)], Bronchospasm [46.2 (42.0 -62.6] and Control group [18.7 (16.0-24.7)] (p< 0.05). CONCLUSIONS: Non-asthmatic patients with intraoperative bronchospasm detected during anesthesia and endotracheal intubation showed increased expired nitric oxide.

Non-asthmatic patients show increased exhaled nitric oxide concentrations

OBJECTIVE: Evaluate whether exhaled nitric oxide may serve as a marker of intraoperative bronchospasm. INTRODUCTION: Intraoperative bronchospasm remains a challenging event during anesthesia. Previous studies in asthmatic patients suggest that exhaled nitric oxide may represent a noninvasive measure of airway inflammation. METHODS: A total of 146,358 anesthesia information forms, which were received during the period from 1999 to 2004, were reviewed. Bronchospasm was registered on 863 forms. From those, three groups were identified: 9 non-asthmatic patients (Bronchospasm group), 12 asthmatics (Asthma group) and 10 subjects with no previous airway disease or symptoms (Control group). All subjects were submitted to exhaled nitric oxide measurements (parts/billion), spirometry and the induced sputum test. The data was compared by ANOVA followed by the Tukey test and Kruskal-Wallis followed by Dunn's test. RESULTS: The normal lung function test results for the Bronchospasm group were different from those of the asthma group (p <0.05). The median percentage of eosinophils in induced sputum was higher for the Asthma [2.46 (0.45-6.83)] compared with either the Bronchospasm [0.55 (0-1.26)] or the Control group [0.0 (0)] (p <0.05); exhaled nitric oxide followed a similar pattern for the Asthma [81.55 (57.6-86.85)], Bronchospasm [46.2 (42.0 -62.6] and Control group [18.7 (16.0-24.7)] (p< 0.05). CONCLUSIONS: Non-asthmatic patients with intraoperative bronchospasm detected during anesthesia and endotracheal intubation showed increased expired nitric oxide.