Pulmonary Emphysema Cross-Linking with Pulmonary Fibrosis and Vice Versa: a Non-usual Experimental Intervention with Elastase and Bleomycin.

Elastase (PPE) is usually used for emphysema models, whereas bleomycin (BLM) is used for fibrosis models. The aim of this study was to investigate the effect of BLM in PPE-induced emphysema, as well as the effect of PPE in BLM-induced fibrosis. C57BL/6 mice were divided into five groups: control, PPE, BLM, PPE + BLM, and BLM + PPE. Mice received saline, PPE (3 U/mouse), or BLM (20 U/kg) by intranasal instillation. Mice from the BLM and BLM + PPE groups received BLM on day 0 and saline or PPE on day 21, respectively. Those in the PPE and PPE + BLM groups received PPE on day 0 and saline or BLM on day 21, respectively. Mice were euthanized on day 42. We performed histology, morphometry in lung sections and ELISA, zymography and western blotting in BAL samples or lung homogenates. In the lungs of PPE + BLM and BLM + PPE groups, we observed inflammation, oxidative stress and expression of MMP-2 and MMP-9. The alveolar enlargement was reduced in the PPE + BLM group, suggesting that the BLM could participate in the alveolar remodeling process. The significance of this result supports future therapeutic approaches targeting extracellular-matrix deposition in patients with emphysema as a way to repair the enlargement of alveoli and airspaces.

Atorvastatin and Simvastatin Promoted Mouse Lung Repair After Cigarette Smoke-Induced Emphysema.

Cigarette smoke (CS) induces pulmonary emphysema by inflammation, oxidative stress, and metalloproteinase (MMP) activation. Pharmacological research studies have not focused on tissue repair after the establishment of emphysema but have instead focused on inflammatory stimulation. The aim of our study was to analyze the effects of atorvastatin and simvastatin on mouse lung repair after emphysema caused by CS. Male mice (C57BL/6, n = 45) were divided into the following groups: control (sham-exposed), CSr (mice exposed to 12 cigarettes a day for 60 days and then treated for another 60 days with the vehicle), CSr+A (CSr mice treated with atorvastatin for 60 days), and CSr+S (CSr mice treated with simvastatin for 60 days). The treatment with atorvastatin and simvastatin was administered via inhalation (15 min with 1 mg/mL once a day). Mice were sacrificed 24 h after the completion of the 120-day experimental procedure. We performed biochemical, morphological, and physiological analyses. We observed decreased levels of leukocytes and cytokines in statin-treated mice, accompanied by a reduction in oxidative stress markers. We also observed a morphological improvement confirmed by a mean linear intercept counting in statin-treated mice. Finally, statins also ameliorated lung function. We conclude that inhaled atorvastatin and simvastatin improved lung repair after cigarette smoke-induced emphysema in mice.

Eucalyptol attenuates cigarette smoke-induced acute lung inflammation and oxidative stress in the mouse.

Short-term cigarette smoke (CS) exposure does not cause emphysema; however, some pathogenesis hallmarks are maintained, such as oxidative stress and inflammation. This study aimed to test the efficacy of eucalyptol against short-term CS exposure in mice. C57BL/6 mice were exposed to 12 cigarettes per day for 5 days (CS group). The control group was exposed to sham smoking. Three groups of mice exposed to CS were treated to different concentrations of eucalyptol (1, 3, 10 mg/mL) via inhalation (15 min/daily) for 5 days (CS + 1 mg, CS+3 mg and CS+10 mg groups). CS group and control one were sham treated by using vehicle. The anti-inflammatory and antioxidant effects of eucalyptol were assessed 24 h after the last CS exposure by determining cell counts, measuring cytokine production and performing western blotting, biochemical and histological analyses. Eucalyptol at 3 mg/mL and 10 mg/mL concentrations reduced total leukocyte numbers compared to the CS group (p < 0.001), while macrophage numbers were reduced at all concentrations (p < 0.001). Myeloperoxidase, used as neutrophil marker, was reduced at 3 mg/mL (p < 0.01) and 10 mg/mL (p < 0.05) concentrations. Eucalyptol reduced cytokine levels (IL-1ß, IL-6 and KC) at 3 mg/mL and 10 mg/mL concentrations (p < 0.01) compared to the CS group. The exception was TNF-α, with a reduction only at 10 mg/mL of eucalyptol compared to the CS group (p < 0.001). Additionally, eucalyptol decreased the NF-kappa B p65 subunit at 3 mg/mL and 10 mg/mL compared to the CS group (p < 0.01). Regarding oxidative stress, eucalyptol reduced reactive oxygen species, superoxide dismutase, catalase and malondialdehyde, mainly at 3 mg/mL and 10 mg/mL concentrations compared to the CS group (at least p < 0.05), parallel to reduced glutathione levels at the same concentrations (p < 0.001). Furthermore, treatment with eucalyptol attenuated CS-induced histopathological alterations. Collectively, these results indicate that eucalyptol acts through a mechanism involving decreased oxidative stress, inflammation and the NF-kappa B p65 subunit against CS-induced acute lung inflammation. Thus, eucalyptol may be a potential agent in the treatment of pulmonary inflammation caused by CS in humans.

T-cell responses associated with resistance to Leishmania infection in individuals from endemic areas for Leishmania (Viannia) braziliensis.

Subclinical or asymptomatic infection is documented in individuals living in endemic areas for leishmaniasis suggesting that the development of an appropriate immune response can control parasite replication and maintain tissue integrity. A low morbidity indicates that intrinsic factors could favor resistance to Leishmania infection. Herein, leishmanial T-cell responses induced in subjects with low susceptibility to leishmaniasis as asymptomatic subjects were compared to those observed in cured cutaneous leishmaniasis (CCL) patients, who controlled the disease after antimonial therapy. All of them have shown maintenance of specific long-term immune responses characterized by expansion of higher proportions of CD4+ as compared to CD8+ Leishmania reactive T-lymphocytes. Asymptomatic subjects had lower indexes of in vitro Leishmania induced lymphoproliferative responses and interferon-gamma (IFN-gamma) production in comparison to CCL patients. On the other hand, interleukin (IL-10) production was much higher in asymptomatics than in CCL, while no differences in IL-5 levels were found. In conclusion, long lived T-cell responses achieved by asymptomatic individuals differed from those who had developed symptomatic leishmaniasis in terms of intensity of lymphocyte activation (proliferation or IFN-gamma) and regulatory mechanisms (IL-10). The absence of the disease in asymptomatics could be explained by their intrinsic ability to create a balance between immunoregulatory (IL-10) and effector cytokines (IFN-gamma), leading to parasite destruction without producing skin tissue damage. The establishment of profiles of cell-mediated immune responses associated with resistance against Leishmania infection is likely to make new inroads into understanding the long-lived immune protection against the disease.

T-cell responses associated with resistance to Leishmania infection in individuals from endemic areas for Leishmania (Viannia) braziliensis

Subclinical or asymptomatic infection is documented in individuals living in endemic areas for leishmaniasis suggesting that the development of an appropriate immune response can control parasite replication and maintain tissue integrity. A low morbidity indicates that intrinsic factors could favor resistance to Leishmania infection. Herein, leishmanial T-cell responses induced in subjects with low susceptibility to leishmaniasis as asymptomatic subjects were compared to those observed in cured cutaneous leishmaniasis (CCL) patients, who controlled the disease after antimonial therapy. All of them have shown maintenance of specific long-term immune responses characterized by expansion of higher proportions of CD4+ as compared to CD8+ Leishmania reactive T-lymphocytes. Asymptomatic subjects had lower indexes of in vitro Leishmania induced lymphoproliferative responses and interferon-gamma (IFN-gamma) production in comparison to CCL patients. On the other hand, interleukin (IL-10) production was much higher in asymptomatics than in CCL, while no differences in IL-5 levels were found. In conclusion, long lived T-cell responses achieved by asymptomatic individuals differed from those who had developed symptomatic leishmaniasis in terms of intensity of lymphocyte activation (proliferation or IFN-gamma) and regulatory mechanisms (IL-10). The absence of the disease in asymptomatics could be explained by their intrinsic ability to create a balance between immunoregulatory (IL-10) and effector cytokines (IFN-gamma), leading to parasite destruction without producing skin tissue damage. The establishment of profiles of cell-mediated immune responses associated with resistance against Leishmania infection is likely to make new inroads into understanding the long-lived immune protection against the disease.

G-CSF does not improve systolic function in a rat model of acute myocardial infarction.

OBJECTIVE: Granulocyte colony-stimulating factor (G-CSF) has been reported to improve cardiac performance by increasing the number of bone marrow stem cell in the peripheral circulation. The aim of this study was to investigate the impact of G-CSF administration on cardiac function in a rat model of acute myocardial infarction. METHODS: Recombinant human G-CSF (Filgrastim, 100 microg/kg, sc) twice a day during seven consecutive days (G-CSF group, n=13) or vehicle (control group, n=10) was administrated three hours after left anterior coronary artery ligation. Cardiac performance was evaluated 19-21 days after myocardial infarction by electro- and echocardiography, hemodynamic and treadmill exercise test. RESULTS: Both infarcted groups exhibit impaired cardiac function compared to sham-operated rats. Moreover, all cardiac functional parameters were not statistically different between G-CSF and infarcted group at resting conditions as well as after treadmill exercise stress test. There was no sign of cardiac regeneration and infarct size was not different on histological analysis between groups. CONCLUSIONS: These data clearly shows that G-CSF treatment was unable to prevent cardiac remodeling or to improve cardiovascular function in a rat model of acute myocardial infarction, by permanent LAD ligation, despite bone marrow stem cell mobilization.

T-cell-mediated immune responses in patients with cutaneous or mucosal leishmaniasis: long-term evaluation after therapy.

T-cell immune responses in patients with cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML) were studied during the active disease, at the end of therapy, and 1 to 17 years posttherapy (long-term follow-up). Lymphocyte proliferative responses, phenotypic characterization of CD4(+) and CD8(+) Leishmania-reactive T cells, and cytokine production were assayed. Patients with active ML and CL showed higher proportions of CD4(+) than CD8(+) T cells. In CL, the healing process was associated with a decrease of CD4(+) and an increase of CD8(+), leading to similar CD4(+) and CD8(+) proportions. This pattern was only seen in ML after long-term therapy. Long-term follow-up of patients with CL showed a positive CD4(+)/CD8(+) ratio as observed during the active disease, although the percentages of these T cell subsets were significantly lower. Patients with CL did not show significant differences between gamma interferon (IFN-gamma) and interleukin-5 (IL-5) production during the period of study. Patients with active ML presented higher IFN-gamma and IL-5 levels compared to patients with active CL. IL-4 was only detected during active disease. Patients long term after cure from ML showed increasing production of IFN-gamma, significant decrease of IL-5, and no IL-4 production. Two apparently beneficial immunological parameters were detected in tegumentary leishmaniasis: (i) decreasing proportions of CD4(+) Leishmania-reactive T cells in the absence of IL-4 production associated with cure of CL and ML and (ii) decreasing levels of IL-5 long after cure, better detected in patients with ML. The observed T-cell responses maintained for a long period in healed patients could be relevant for immunoprotection against reinfection and used as a parameter for determining the prognosis of patients and selecting future vaccine preparations.