Research articleSupplementation with vitamins C and E improves mouse lung repair
Introduction
Chronic obstructive pulmonary disease (COPD) is a major and increasing global health problem, which is predicted to become the third commonest cause of death and the fifth commonest cause of disability in the world by 2020 [1], [2]. Cigarette smoke (CS)-induced emphysema is one of the major causes of COPD [3], [4], but there are several other risk factors, including air pollution (particularly indoor air pollution from burning fuels) [5], poor diet [6] and occupational exposure [7]. Emphysema is characterized by enlargement of alveolar spaces together with destruction of alveolar walls in the absence of obvious fibrosis [8]. CS causes an inflammatory response in the lower respiratory tract characterized by accumulation of alveolar macrophages associated with a recruitment of fewer neutrophils [9], [10]. These activated inflammatory cells release a variety of mediators, including proteases, oxidants and toxic peptides, which can damage lung structures and are believed to be a major cause of the tissue destruction found in emphysema [11].
Matrix metalloproteinases (MMPs) are a large family of zinc-dependent proteinases that regulate the destruction of extracellular matrix components in lung [12]. There is increasing evidence for a role for MMPs in COPD [4]. The concentration, expression and activity of lung MMP-9 (gelatinase B) are increased in emphysema patients [13], [14]. The interest in MMPs has also been heightened by the demonstration that emphysema induced by chronic CS exposure is prevented in MMP-12−/− mice [15].
Oxidative stress plays a key role in the pathophysiology of COPD and amplifies the inflammatory and destructive process [16], [17]. Reactive oxygen species (ROS) from CS or from inflammatory cells (particularly macrophages and neutrophils) result in several damaging effects in COPD [18], including decreased antiprotease defenses [19] and antioxidants. Many of the adverse effects of smoking may result from oxidative damage to critical biological molecules [9]. Epidemiological evidence indicates that reduced dietary intake of antioxidants may be a determinant of COPD [20]; moreover, population surveys have linked a low dietary intake of the antioxidant vitamins C and E to declining lung function [21]. Supplementary treatment with vitamin E (100 mg/kg/day) reduced bacterial colonization in the lower respiratory tract of smoke-treated rats [22]. Moreover, pretreatment (100 mg/kg/day) of either ascorbic acid or α-tocopherol acetate before smoke inhalation completely prevented single-strand DNA breaks in the lung, stomach and liver [23]. Also, α-tocopherol (50 mg/kg/day) and ascorbic acid (100 mg/kg/day) protected sperm by inhibiting the induction of ROS generation by Aroclor 1254 [24]. Bezerra et al. [9] showed that inflammatory alveolar cells and levels of tumor necrosis factor (TNF)-α, NF-κB and MMP-12 in lungs of mice exposed to CS for a short period (5 days) were reduced to control levels by ascorbic acid, α-tocopherol or, more efficiently, supplementation with both vitamins. However, it remains unclear whether vitamins C and E may play a role in mouse lung repair after emphysema induced by long-term CS exposure.
Because of the enormous burden of COPD and escalating health care costs, there is now renewed interest in the underlying cellular and molecular mechanisms and a search for new treatment strategies. Vitamins C and E are antioxidants and can therefore be expected to change the oxidant–antioxidant imbalance induced in lungs by CS. Our aim was to study the effects of vitamins C and E on mouse lung repair as evaluated by catalase (CAT) and superoxide dismutase (SOD) activities, by quantification of TNF-α and MMP-9 zymography in lung homogenates, by cell quantification in bronchoalveolar lavage (BAL) fluid and by morphometric and stereological parameters.
Section snippets
Reagents and animals
Thiobarbituric acid, adrenaline, acrylamide, gelatin, sodium dodecyl sulfate (SDS), Triton X-100, Tris–HCl, CaCl2, ZnCl2, Coomassie Blue, hematoxylin–eosin, orcein and Sirius red were purchased from Sigma Chemical Co. (St. Louis, MO, USA). Specific enzyme-linked immunosorbent assay (ELISA) for TNF-α was purchased from R&D Systems (Minneapolis, MN, USA). Diff-Quik was purchased from Baxter Dade AG (Dudingen, Switzerland). Bradford reagent was purchased from Bio-Rad (Hercules, CA, USA). Formalin,
Vitamins C and E improved lung repair after emphysema
Histological changes are illustrated in Fig. 1. The control group lungs were histologically normal, with parenchyma consisting of alveoli connected to alveolar ducts, separated from each other only by thin alveolar septa (Fig. 1A). Collagen and elastic fibers in the alveolar septa were characterized by delicate branching fibers (Fig. 1B and C).
The lungs of all CSv mice showed emphysematous lesions, areas of alveolar septa disruption and enlarged air spaces (Fig. 1D). Collagen and elastic fibers
Discussion
The present study reports lung repair after emphysema induced by long-term CS exposure in mice supplemented with vitamins C and E. A marked neutrophilia associated with high TNF-α content and emphysema was observed in mice previously exposed to smoke for 60 days (CSv group), but the inflammatory status was reduced by vitamins C and E with improved lung histology.
In COPD, MMPs play an important role in the destruction of lung tissue [3], [11]. MMPs attack and degrade extracellular matrix
Acknowledgments
Funding for this study was provided by FAPERJ, CNPq and UERJ.
References (42)
- et al.
A qualitative study of compliance with medication and lifestyle modification in chronic obstructive pulmonary disease (COPD)
Prim Care Respir J
(2004) - et al.
Oxidant–protease interaction in the lung. Prospects for antioxidant therapy
Chest
(1996) - et al.
Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs in the respiratory tract: potential implications in asthma and other lung diseases
Eur J Pharmacol
(2006) - et al.
Ameliorative effect of vitamins (alpha-tocopherol and ascorbic acid) on PCB (Aroclor 1254) induced oxidative stress in rat epididymal sperm
Reprod Toxicol
(2007) Catalase in vitro
Methods Enzymol
(1984)A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein–dye binding
Anal Biochem
(1976)- et al.
Quantitative analysis of matrix metalloproteinases-2 and -9, and their tissue inhibitors-1 and -2 in human placenta throughout gestation
Life Sci
(2000) - et al.
Neutrophil elastase contributes to cigarette smoke-induced emphysema in mice
Am J Pathol
(2003) - et al.
The role of ascorbate in the prolyl hydroxylase reaction
Biochem Biophys Res Commun
(1978) - et al.
Epidemiology of chronic obstructive pulmonary disease: health effects of air pollution
Respirology
(2006)
Global impact of COPD
Exp Lung Res
Pathogenesis of COPD
Semin Respir Crit Care Med
The role of matrix metalloproteinases (MMPs) in the pathophysiology of chronic obstructive pulmonary disease (COPD): a therapeutic role for inhibitors of MMPs?
Inflamm Res
Chronic obstructive pulmonary disease (COPD): smoking remains the most important cause
N Z Med J
Chronic obstructive pulmonary disease (COPD) and occupational exposures
J Occup Med Toxicol
Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. NHLBI/WHO Global Initiative for Chronic Obstructive Lung Disease (GOLD) Workshop summary
Am J Respir Crit Care Med
Alpha-tocopherol and ascorbic acid supplementation reduced acute lung inflammatory response by cigarette smoke in mouse
Nutrition
Time course of cigarette smoke-induced pulmonary inflammation in mice
Eur Respir J
Release and activity of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 by alveolar macrophages from patients with chronic obstructive pulmonary disease
Am J Respir Cell Mol Biol
Matrix metalloproteinase-mediated extracellular matrix protein degradation in human pulmonary emphysema
Lab Invest
Requirement for macrophage elastase for cigarette smoke-induced emphysema in mice
Science
Cited by (31)
Diallyl disulfide prevents cigarette smoke-induced emphysema in mice
2021, Pulmonary Pharmacology and TherapeuticsEffects of dietary vitamin E on growth, immunity and oxidation resistance related to the Nrf2/Keap1 signalling pathway in juvenile Sillago sihama
2020, Animal Feed Science and TechnologyEucalyptol promotes lung repair in mice following cigarette smoke-induced emphysema
2019, PhytomedicineCitation Excerpt :Some scientific studies have used natural products or compounds isolated from natural products for the treatment of COPD. Zataria multiflora (Boskabady and Gholami Mahtaj, 2015), mate tea (Lanzetti et al., 2011), vitamin C/E (Valenca et al., 2008) and propolis extract (Barroso et al., 2017) were associated with preventive and/or therapeutic resource for lung inflammation and oxidative stress caused by CS. However, this is the first study to demonstrate the anti-inflammatory and antioxidant effects of eucalyptol in mouse pulmonary emphysema induced by CS.
AT-RVD1 repairs mouse lung after cigarette smoke-induced emphysema via downregulation of oxidative stress by NRF2/KEAP1 pathway
2018, International ImmunopharmacologyCitation Excerpt :In addition, we acknowledge that we did not quantify the expression of intranuclear Nrf2 to confirm its translocation from the nucleus; however, the increase in the expression of one of the main enzymes produced by its translocation and subsequent transduction (HO-1) supports this hypothesis. Finally, BAL cells and ROS observed here are inconsistent with previous result from our group [50–52]. However this apparent inconsistency maybe due vehicle/resource route of administration (please see Supplement).
Propolis reversed cigarette smoke-induced emphysema through macrophage alternative activation independent of Nrf2
2017, Bioorganic and Medicinal ChemistryCitation Excerpt :This model characterizes a post-treatment since at 60 days, the animals already had emphysema and the treatment was initiated after disease was established. Mice from the CS groups were exposed to 12 commercial filtered cigarettes per day (4 cigarettes in the morning, 4 cigarettes at noon and 4 cigarettes in the afternoon) using a smoking chamber as described previously.40–43 Briefly, the animals were placed in an inhalation chamber (40 cm long, 30 cm wide, 25 cm high) inside an exhaustion chapel.