Early detection of skeletal muscle bioenergetic deficit by magnetic resonance spectroscopy in cigarette smoke-exposed mice.

Skeletal muscle dysfunction is a common complication and an important prognostic factor in patients with chronic obstructive pulmonary disease (COPD). It is associated with intrinsic muscular abnormalities of the lower extremities, but it is not known whether there is an easy way to predict its presence. Using a mouse model of chronic cigarette smoke exposure, we tested the hypothesis that magnetic resonance spectroscopy allows us to detect muscle bioenergetic deficit in early stages of lung disease. We employed this technique to evaluate the synthesis rate of adenosine triphosphate (ATP) and characterize concomitant mitochondrial dynamics patterns in the gastrocnemius muscle of emphysematous mice. The fibers type composition and citrate synthase (CtS) and cytochrome c oxidase subunit IV (COX4) enzymatic activities were evaluated. We found that the rate of ATP synthesis was reduced in the distal skeletal muscle of mice exposed to cigarette smoke. Emphysematous mice showed a significant reduction in body weight gain, in the cross-sectional area of the total fiber and in the COX4 to CtS activity ratio, due to a significant increase in CtS activity of the gastrocnemius muscle. Taken together, these data support the hypothesis that in the early stage of lung disease, we can detect a decrease in ATP synthesis in skeletal muscle, partly caused by high oxidative mitochondrial enzyme activity. These findings may be relevant to predict the presence of skeletal bioenergetic deficit in the early stage of lung disease besides placing the mitochondria as a potential therapeutic target for the treatment of COPD comorbidities.

Obstructive sleep apnea and nocturnal hypoxemia are associated with an increased risk of lung cancer.

STUDY OBJECTIVES: To identify a link between sleep disordered breathing, nocturnal hypoxemia, and lung cancer. METHODS: We conducted a cross-sectional study of a combined cohort of 302 individuals derived from the sleep apnea in lung cancer study (SAIL; NCT02764866) investigating the prevalence of sleep apnea in lung cancer, and the sleep apnea in lung cancer screening study (SAILS; NCT02764866) investigating the prevalence of sleep apnea in a lung cancer screening program. All subjects had spirometry and a chest CT, underwent home sleep apnea testing (HSAT), and completed a sleep related questionnaire. Subjects from the SAIL study underwent HSAT prior to initiating oncologic therapy or surgery. Subjects with an apnea-hypopnea index (AHI) > 15 were compared with a control group of individuals with an AHI < 15. Propensity score, near neighbor matching, and logistic regression adjusted for potential confounders, were used in order to evaluate the association between sleep apnea, the AHI, oxygen desaturation indices and lung cancer. RESULTS: The prevalence of sleep apnea and lung cancer in the combined cohort was 42% and 21%, respectively. Lung cancer was 8% more prevalent in patients with an AHI >15. The difference was statistically significant when assessed by propensity score matching (p = 0.015) and nearest neighbor matching (p = 0.041). Binary logistic regression adjusted for potential confounders revealed a statistically significant association between AHI (p = 0.04), nocturnal hypoxemia, including time spent below 90% oxyhemoglobin saturation (T90%; p = 0.005), 3% oxygen desaturation index (ODI3; p = 0.02) and lung cancer. CONCLUSIONS: Sleep apnea and nocturnal hypoxemia are associated with an increased prevalence of lung cancer. CLINICAL TRIAL REGISTRATION: SAIL study (NCT02764866) and SAILS study (NCT02764866).

Proliferative activity of liver growth factor is associated with an improvement of cigarette smoke-induced emphysema in mice.

Cigarette smoke (CS)-induced emphysema is a major component of chronic obstructive pulmonary disease (COPD). COPD treatment is based on the administration of bronchodilators and corticosteroids to control symptoms and exacerbations, however, to date, there are no effective therapies to reverse disease progression. Liver growth factor (LGF) is an albumin-bilirubin complex with mitogenic properties, whose therapeutic effects have previously been reported in a model of emphysema and several rodent models of human disease. To approach the therapeutic effect of LGF in a model of previously established emphysema, morphometric and lung function parameters, matrix metalloproteinase (MMP) activity and the expression of several markers, such as VEGF, PCNA, 3NT and Nrf2, were assessed in air-exposed and CS-exposed C57BL/6J male mice with and without intraperitoneal (i.p.) injection of LGF. CS-exposed mice presented a significant enlargement of alveolar spaces, higher alveolar internal area and loss of lung function that correlated with higher MMP activity, higher expression of 3NT and lower expression of VEGF. CS-exposed mice injected with LGF, showed an amelioration of emphysema and improved lung function, which correlated with lower MMP activity and 3NT expression and higher levels of VEGF, PCNA and Nrf2. Taken together, this study suggests that LGF administration ameliorates CS-induced emphysema, highlights the ability of LGF to promote alveolar cell proliferation and may be a promising strategy to revert COPD progression.

Liver growth factor treatment reverses emphysema previously established in a cigarette smoke exposure mouse model.

Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease largely associated with cigarette smoke exposure (CSE) and characterized by pulmonary and extrapulmonary manifestations, including systemic inflammation. Liver growth factor (LGF) is an albumin-bilirubin complex with demonstrated antifibrotic, antioxidant, and antihypertensive actions even at extrahepatic sites. We aimed to determine whether short LGF treatment (1.7 µg/mouse ip; 2 times, 2 wk), once the lung damage was established through the chronic CSE, contributes to improvement of the regeneration of damaged lung tissue, reducing systemic inflammation. We studied AKR/J mice, divided into three groups: control (air-exposed), CSE (chronic CSE), and CSE + LGF (LGF-treated CSE mice). We assessed pulmonary function, morphometric data, and levels of various systemic inflammatory markers to test the LGF regenerative capacity in this system. Our results revealed that the lungs of the CSE animals showed pulmonary emphysema and inflammation, characterized by increased lung compliance, enlargement of alveolar airspaces, systemic inflammation (circulating leukocytes and serum TNF-α level), and in vivo lung matrix metalloproteinase activity. LGF treatment was able to reverse all these parameters, decreasing total cell count in bronchoalveolar lavage fluid and T-lymphocyte infiltration in peripheral blood observed in emphysematous mice and reversing the decrease in monocytes observed in chronic CSE mice, and tends to reduce the neutrophil population and serum TNF-α level. In conclusion, LGF treatment normalizes the physiological and morphological parameters and levels of various systemic inflammatory biomarkers in a chronic CSE AKR/J model, which may have important pathophysiological and therapeutic implications for subjects with stable COPD.

Home ventilation therapy in obstructive sleep apnea-hypopnea syndrome.

Obstructive sleep apnea-hypopnea is a highly prevalent disease that is often underdiagnosed at present. It has a significant economic and social welfare impact, accounting for a large part of the resources assigned to home respiratory therapies. As part of the 2014 SEPAR Year of the Chronic Patient and Domiciliary Respiratory Care sponsored by the Spanish Society of Pulmonology and Thoracic Surgery, this article reviews the most recent publications on the indications and controversial issues in the treatment of sleep apnea, the latest evidence for indication of various positive pressure devices, and adjustment modes, ranging from the use of empirical formulae or mathematical estimations to modern auto-CPAP equipment, while not forgetting the gold standard of manual titration. Emphasis is placed on the need for monitoring required by patients to ensure treatment adherence and compliance. Finally, other therapies that are not the object of this article are briefly reviewed.

Role of recently migrated monocytes in cigarette smoke-induced lung inflammation in different strain of mice.

This study investigates the role of proinflammatory monocytes recruited from blood circulation and recovered in bronchoalveolar lavage (BAL) fluid in mediating the lung damage in a model of acute cigarette smoke (CS)-induced lung inflammation in two strains of mice with different susceptibility to develop emphysema (susceptible -C57BL/6J and non susceptible -129S2/SvHsd). Exposure to whole-body CS for 3 consecutive research cigarettes in one single day induced acute inflammation in the lung of mice. Analysis of BAL fluid showed more influx of recently migrated monocytes at 72 h after CS-exposition in susceptible compared to non susceptible mice. It correlated with an increase in MMP-12 and TNF-α protein levels in the lung tissue, and with an increment of NF-κB translocation to the nucleus measured by electrophoretic mobility shift assay in C57BL/6J mice. To determine the functional role of these proinflammatory monocytes in mediating CS-induced airway inflammation, alveolar macrophages and blood monocytes were transiently removed by pretreatment with intratracheal and intravenous liposome-encapsulated CL2MDP, given 2 and 4 days prior to CS exposure and their repopulation was studied. Monocytes/macrophages were maximally depleted 48 h after last liposome application and subsequently recently migrated monocytes reappeared in BAL fluid of susceptible mice at 72 h after CS exposure. Recently migrated monocytes influx to the lung correlated with an increase in the MMP-12 protein level in the lung tissue, indicating that the increase in proinflammatory monocytes is associated with a major tissue damaging. Therefore our data confirm that the recruitment of proinflammatory recently migrated monocytes from the blood are responsible for the increase in MMP-12 and has an important role in the pathogenesis of lung disease induced by acute lung inflammation. These results could contribute to understanding the different susceptibility to CS of these strains of mice.

Spirometry. Spanish Society of Pulmonology and Thoracic Surgery (SEPAR).

Spirometry is the main pulmonary function test and is essential for the evaluation and monitoring of respiratory diseases. Its utility transcends the field of Respiratory Medicine, is becoming increasingly important in primary care and applications have even been described outside the field of respiratory diseases. This document is therefore intended to serve as support for all health professionals who use spirometry, providing recommendations based on the best scientific evidence available. An update of the indications and contraindications of the test is proposed. The document sets out recommendations on the requirements necessary for conventional spirometers and portable office equipment, as well as on spirometer hygiene and quality control measures. Spirometric parameters that must be considered, performance of manoeuvres, criteria for acceptability and repeatability of measurements and their quality control are defined. A proposal is also established for presentation of the results and an evaluation and interpretation is proposed according to information generated in recent years. Finally, lines of adaptation and integration of spirometry in the field of new technologies are considered.

Cigarette smoke-induced oxidative stress in skeletal muscles of mice.

Cigarette smoke (CS)-induced oxidative stress may cause muscle alterations in chronic conditions such as chronic obstructive pulmonary disease (COPD). We sought to explore in AKR/J mice exposed to CS for 6 months and in control animals, levels of protein oxidation, oxidized proteins (immunoblotting, proteomics) and antioxidant mechanisms in both respiratory and limb muscles, body weight modifications, systemic inflammation, and lung structure. Compared to control mice, CS-exposed animals exhibited a reduction in body weight gain at 3 months and thereafter, showed lung emphysema, and exhibited increased oxidative stress levels in their diaphragms and gastrocnemius at 6 months. Proteins involved in glycolysis, ATP production and distribution, carbon dioxide hydration, and muscle contraction were carbonylated in respiratory and limb muscles. Blood tumor necrosis factor (TNF)-alpha levels were significantly greater in CS-exposed mice than in control animals. In AKR/J mice, chronic exposure to CS induces lung emphysema concomitantly with greater oxidative modifications on muscle proteins in both respiratory and limb muscles, and systemic inflammation.

Early detection of susceptibility to acute lung inflammation by molecular imaging in mice exposed to cigarette smoke.

Matrix metalloproteinases (MMPs) are extracellular proteolytic enzymes involved in acute lung inflammation in response to cigarette smoke exposure (CSE). We present the in vivo detection of MMP activity using a specific MMP-activatable, near-infrared, polymer-based proteolytic probe in strains of mice with different susceptibility to developing smoking-induced emphysema (susceptible mice, C57BL/6j, and resistant mice, 129S2/SvHsd) to characterize the distinctive profile of CSE-induced acute inflammation. In vivo imaging of pulmonary inflammation expressing MMPs revealed a significantly different median ratio twofold higher in smoker than in nonsmoker susceptible mice (C57BL/6j) and no significant differences between the smoker and the nonsmoker group in resistant mice (129S2/SvHsd). Ex vivo imaging of the lungs of each group of mice confirmed the same in vivo experiment results obtained for both strains of mice. In the biochemical study of lung tissue, the proteolytic signal colocalized with the endogenously expressed MMP protein levels, with MMP-9 levels that are 2.2 times higher than in the nonsmoke-exposed group in C57BL/6j mice and no significant differences in the 129S2/SvHsd mice. The MMP-activatable probe provides a useful reagent for the in vivo and ex vivo detection of MMP-selective proteolytic activity. We are able to distinguish between susceptible and resistant strains of mice in terms of the profile of MMP activity in the early stages of pulmonary disease.

[Liver growth factor improves pulmonary fibrosis secondary to cadmium administration in rats]. / El factor de crecimiento de hígado mejora la fibrosis pulmonar inducida tras la administración de cadmio en ratas.

INTRODUCTION: Liver growth factor (LGF) is a liver mitogen with regenerating and anti-fibrotic activity even at extrahepatic sites. We used LGF in a lung fibrosis model induced by cadmium chloride (CdCl(2)), to study its antifibrotic capacity. METHODS: Forty-two male Wistar rats were administered a single dose of 0.5ml/rat of CdCl2 0.025% (n=21) or the same volume of saline (control group, n=21). After 35 days, once a lesion was established, we started a 3 week treatment with LGF, after which we determined lung function--inspiratory capacity (IC), lung compliance (LC), forced vital capacity (FVC) and expiratory flow at 75% (FEF75%)-, lung morphometry--alveolar internal area (AIA), mean linear intersection (LM)-, and collagen (both by Sirius red and hydroxyproline residues) and elastin contents. RESULTS: Pulmonary fibrosis in CdCl(2) rats was characterized by a marked decrease in pulmonary function with respect to healthy controls -reductions of 28% in IC, 38% in CL, 31% in FVC, and 54% in FEF75%- which was partially recovered after LGF injection -18% IC, 27% CL, 19% FVC and 35% FEF75%-; increase in collagen and elastin contents -165% and 76%, respectively, in CdCl2 rats, versus 110% and 34% after LGF injection-; and increases in AIA and LM, partially reverted by LGF. CONCLUSIONS: Together, these data seem to demonstrate that LGF is able to improve lung function and partially reverts the increase in lung matrix proteins produced by CdCl(2) instillation.

Oral N-acetylcysteine attenuates elastase-induced pulmonary emphysema in rats.

STUDY OBJECTIVE: To study the effect of the antioxidant N-acetylcysteine (NAC) in the development of elastase-induced emphysema in rats. MATERIALS AND METHODS: Wistar rats (n = 72) were orotracheally instilled with 75 IU elastase or saline solution. Eighteen rats from each group received the antioxidant NAC from 2 days before induction of the lesion until they were killed 2, 8, and 28 days after instillation. The effects of treatment were assessed by measuring collagen content for the left lung, a histopathology evaluation (ie, mean alveolar internal surface area (AIA) and mean linear intercept measurement), and lung function. RESULTS: Twenty-eight days after elastase instillation, rats treated with NAC showed significant attenuation of the lesion in comparison with rats treated only with elastase, including the following: normalization of mean (+/- SEM) collagen content (1.23 +/- 0.09 vs 1.51 +/- 0.10 mg per left lung, respectively; p < 0.05); partial inhibition of mean AIA (14,860 +/- 1,135 vs 19,622 +/- 1,294 micro m(2), respectively; p < 0.05) and mean linear intercept (108.8 +/- 3.7 vs 123.0 +/- 4.2 micro m, respectively; p < 0.05); and increases and improvement in expiratory flows (27.8 +/- 1.2 vs 23.4 +/- 1.3 mL/s, respectively; p < 0.05). NAC was not able to avoid the compliance increase in the elastase-plus-NAC group. CONCLUSION: Consistent with the results of anatomic, pathologic, and functional studies, NAC is able to attenuate the lesions induced by elastase in rats, which is in accordance with previous data supporting the idea that oxidant injury could contribute to the development of elastase-induced emphysema.

Gene therapy with galectin-3 inhibits bronchial obstruction and inflammation in antigen-challenged rats through interleukin-5 gene downregulation.

The pathophysiology of asthma involves an intricate network of molecular and cellular interactions. Elevated Th2 cytokines (interleukin [IL]-5 and IL-4) associated with eosinophilic inflammation characterize allergic diseases and provide potential targets for immunomodulation. Recent evidence has demonstrated that galectin-3 induces selective downregulation of IL-5 gene expression in several cell types (eosinophils, T cell lines, and antigen specific T cells). Accordingly, we sought to elucidate whether in vivo intratracheal instillation of plasmid DNA encoding galectin-3 would inhibit an experimental asthmatic reaction in a rat model with increased eosinophils and T cells in bronchoalveolar fluid and impaired pulmonary function. We found that instillation of galectin-3 gene in these rats led to normalization of the eosinophil and T cell count in bronchoalveolar lavage fluid and that there was a strong concomitant inhibition of IL-5 mRNA in the lungs. As a consequence, galectin-3-treated rats showed recovery of pulmonary functional parameters, such as pulmonary pressure and expiratory flows. These data emphasize the potential utility of galectin-3 as a novel therapeutic approach for treatment of allergic asthma.