Rat Model Of Chronic Obstructive Pulmonary Disease Research Articles

Baicalin Exerts Anti-Airway Inflammation and Anti-Remodelling Effects in Severe Stage Rat Model of Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is a worldwide epidemic. Current approaches are disappointing due to limited improvement of the disease development. The present study established 36-week side stream cigarette smoke induced rat model of COPD with advanced stage feature and evaluted the effects of baicalin on the model. Fifty-four Sprague–Dawley rats were randomly divided into six groups including room air control, cigarette smoke exposure, baicalin (40 mg/kg, 80 mg/kg, and 160 mg/kg), and budesonide used as a positive control. Rats were exposed to cigarette smoke from 3R4F research cigarettes. Pulmonary function was evaluated and pathological changes were also observed. Cytokine level related to airway inflammation and remodelling in blood serum, bronchoalveolar lavage fluid, and lung tissue was determined. Blood gases and HPA axis function were also examined, and antioxidant levels were quantified. Results showed that, after treatment with baicalin, lung function was improved and histopathological changes were ameliorated. Baicalin also regulated proinflammatory and anti-inflammatory balance and also airway remodelling and anti-airway remodelling factors in blood serum, bronchoalveolar lavage fluid, and lung tissue. Antioxidant capacity was also increased after treatment with baicalin in COPD rat model. HPA axis function was improved in baicalin treated groups as compared to model group. Therefore, baicalin exerts lung function protection, proinflammatory and anti-inflammatory cytokine regulation, anti-airway remodelling, and antioxidant role in long term CS induced COPD model.

Protective effect of autophagy on endoplasmic reticulum stress induced apoptosis of alveolar epithelial cells in rat models of COPD.

During the present study, we explored the protective effects of autophagy on endoplasmic reticulum (ER) stress (ERS) induced apoptosis belonging to alveolar epithelial cells (AECs) in rat models with chronic obstructive pulmonary disease (COPD). Fifty-six 12-week-old male Sprague–Dawley (SD) rats were randomly assigned into the COPD group (rats exposed to cigarette smoke (CS)), the 3-methyladenine (3-MA) intervention group (COPD rats were administrated with 10 mg/kg autophagy inhibitors), the chloroquine (CQ)-intervention group (COPD rats were administrated 40 mg/kg CQ), and the control group (rats breathed in normal saline). The forced expiratory volume in 0.3 s/forced vital capacity (FEV0.3/FVC%), inspiratory resistance (RI), and dynamic lung compliance (Cdyn) were measured and recorded. The expressions of PKR-like ER kinase (PERK) and CCAAT/enhancer-binding protein-homologous protein (CHOP) were detected by immunohistochemistry. The cell apoptotic rates of AECs were analyzed by terminal deoxynucleotidyl transferase (TdT) mediated dUTP-biotin nick end-labeling (TUNEL) staining. The expression levels of light chain 3 (LC3-II), p62, Beclin-1, ATG5, ATG7, Caspase-12, and Caspase-3 were detected by Western blotting. Results showed that the COPD group exhibited a lower FEV0.3/FVC% and Cdyn, and a higher RI than the control group. Compared with the control group, the integrated optical density (IOD) values of PERK and CHOP, the apoptotic rate of AECs, and expressions of LC3-II, Beclin-1, ATG5, ATG7, Caspase-3, and Caspase-12 expressions were significantly higher, whereas p62 expression was significantly lower in the COPD group. Based on the results obtained during the present study, it became clear that the inhibition of autophagy could attenuate the ERS-induced apoptosis of AECs in rats with COPD.

Tumor necrosis factor-like weak inducer of apoptosis regulates quadriceps muscle atrophy and fiber-type alteration in a rat model of chronic obstructive pulmonary disease

BackgroundIn chronic obstructive pulmonary disease (COPD), weakness and muscle mass loss of the quadriceps muscle has been demonstrated to predict survival and mortality rates of patients. Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK), as a member of the TNF superfamily, has recently been identified as a key regulator of skeletal muscle wasting and metabolic dysfunction. So our aim was to study the role of TWEAK during quadriceps muscle atrophy and fiber-type transformation in COPD model rats and its possible pathway.MethodsForty-four healthy male adult Wistar rats were randomly divided into two groups: A normal control group (n = 16) and a COPD model group (n = 28). The COPD group was exposed to cigarette smoke for 90 d and injected with porcine pancreatic elastase on day 15, whereas the control group was injected with saline alone. Following treatment, weights of the quadriceps muscles were measured and hematoxylin and eosin staining was performed to identify structural changes in lung and quadriceps muscle tissue. Immunohistochemical staining was also conducted to determine the localization of TWEAK, nuclear factor (NF)-κB, muscle ring finger (MuRF)-1 and proliferator-activated coactivator (PGC)-1a proteins in the quadriceps muscle, and western blotting was used to assess the level of protein expression.ResultsCompared with controls, COPD model rats exhibited significantly lower quadriceps muscle weight (P < 0.05) accompanied by fiber atrophy and disordered fiber arrangement, a wide gap between adjacent muscle fibers, a significant reduction in nuclear number (P < 0.05) and an uneven size distribution. The proportion of fiber types was also significantly altered (P < 0.05). In addition, TWEAK expression in the quadriceps muscle of COPD model rats was significantly higher than that in control rats (P < 0.05), and was significantly associated with quadriceps atrophy and fiber-type alteration (P < 0.05). Levels of NF-κB, MuRF1 and PGC-1α expression also significantly differed between the two groups (P < 0.05).ConclusionsCollectively these data suggest that increased levels of TWEAK may lead to skeletal muscle atrophy and fiber-type alteration, which in turn may be associated with activation of the ubiquitin-proteasome pathway, involving NF-κB, MuRF1 and PGC-1α as potential regulatory factors. These preliminary results in rats suggest that TWEAK may be a therapeutic target for the treatment of muscle atrophy in COPD.

Curcumin attenuates skeletal muscle mitochondrial impairment in COPD rats: PGC-1α/SIRT3 pathway involved

Curcumin has been widely used to treat numerous diseases due to its antioxidant property. The aim of the present study is to investigate the effect of curcumin on skeletal muscle mitochondria in chronic obstructive pulmonary disease (COPD) and its underlying mechanism. The rat model of COPD was established by cigarette smoke exposure combined with intratracheal administration of lipopolysaccharide. Airway inflammation and emphysema were notably ameliorated by the treatment with curcumin. Oral administration of curcumin significantly improved muscle fiber atrophy, myofibril disorganization, interstitial fibrosis and mitochondrial structure damage in the skeletal muscle of COPD rats. Mitochondrial enzyme activities of cytochrome c oxidase, succinate dehydrogenase, Na+/K+-ATPase and Ca2+-ATPase in skeletal muscle mitochondria from COPD rats were significantly increased after treatment with curcumin. Moreover, curcumin significantly decreased oxidative stress and inflammation by determining the levels of malondialdehyde, manganese superoxide dismutase, glutathione peroxidase, catalase, IL-6 and TNF-α in skeletal muscle of COPD rats. Furthermore, curcumin significantly increased the mRNA and protein expression of PGC-1α and SIRT3 in the skeletal muscle tissues of COPD rats. These results suggested that curcumin can attenuate skeletal muscle mitochondrial impairment in COPD rats possibly by the up-regulation of PGC-1α/SIRT3 signaling pathway.

The Effects of Resveratrol on Inflammation and Oxidative Stress in a Rat Model of Chronic Obstructive Pulmonary Disease

Oxidative stress and inflammation are hypothesized to contribute to the pathogenesis of chronic obstructive pulmonary disease (COPD). Resveratrol (trans-3,5,4′-trihydroxystilbene) is known for its antioxidant and anti-inflammatory properties. The study aimed to investigate the effects of resveratrol in a rat model with COPD on the regulation of oxidative stress and inflammation via the activation of Sirtuin1 (SIRTl) and proliferator-activated receptor-γ coactivator-1α (PGC-1α). Thirty Wistar rats were randomly divided into three groups: control group, COPD group and resveratrol intervention group. The COPD model was established by instilling with lipopolysaccharide (LPS) and challenging with cigarette smoke (CS). The levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) in serum were measured. The levels of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) were measured. The expression levels of SIRT1 and PGC-1α in the lung tissues were examined by immunohistochemistry as well as real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR) and western blotting analysis. After the treatment with resveratrol (50 mg/kg), compared with the COPD group, alleviation of inflammation and reconstruction in the small airways of the lungs were seen. Resveratrol might be correlated not only with the lower level of MDA and the higher activity of SOD, but also with the upregulation of SIRT1 and PGC-1α expression. Resveratrol treatment decreased serum levels of IL-6 and IL-8. Our findings indicate that resveratrol had a therapeutic effect in our rat COPD model, which is related to the inhibition of oxidative stress and inflammatory response. The mechanism may be related to the activation and upgrading of the SIRT1/PGC-1α signaling pathways. Thus resveratrol might be a therapeutic modality in COPD.

Effects of Sodium Houttuyfonate on Pulmonary Inflammation in COPD Model Rats.

The anti-inflammatory effect of sodium houttuyfonate (SH), an herbal-originated drug that used in China clinically, was investigated on chronic obstructive pulmonary disease (COPD) inflammatory model rats induced by combination usage of cigarette smoke (CS) and lipopolysaccharide (LPS). The morphology of the lung tissue, the expression levels of cytokines in the bronchoalveolar lavage fluid (BALF), the protein levels of TLR4, NF-κB p65, and SIGIRR, and the mRNA levels of TLR4, MyD88, NF-κB p65, and SIGIRR in lung tissues were investigated, respectively. After treated by SH (24.3mg/kg), the abnormal morphology changes of lung tissues in COPD rats, such as neutrophil infiltration and airway obstruction, were considerably alleviated, as well as both proinflammatory cytokines, TNF-α and IL-1β, significantly decreased in BALF. The mRNA level of TLR4, MyD88, and NF-κB p65 and protein expression of TLR4 and NF-κB p65 in lung tissues decreased significantly after SH treatment, while both SIGIRR mRNA and protein levels increased significantly. These results suggest that SH markedly attenuated the pulmonary inflammation induced by CS and LPS and protected the lung tissue in COPD model rat. The anti-inflammatory effects were related to suppress the TLR4/NF-κB pathway dependent on MyD88. TIR8/SIGIRR might contribute to the protective effects of SH on pulmonary inflammation.

Recuperating lung decoction attenuates inflammation and oxidation in cigarette smoke-induced COPD in rats via activation of ERK and Nrf2 pathways.

Oxidative/antioxidative imbalance and chronic inflammation are the main contributors to the pathogenesis of chronic obstructive pulmonary disease (COPD). This study evaluated the effect of recuperating lung decoction (RLD) on inflammation and oxidative stress in rats with COPD induced by cigarette smoke and lipopolysaccharides (LPS). We used intravenous infusion of LPS combined with cigarette smoke exposure as a COPD rat model. We observed that RLD treatment increased the protein level of GSH and the ratio of GSH/GSSG but decreased 8‐OHdG and 4‐HNE in the serum. Furthermore, RLD significantly inhibited the expressions of IL‐1β, IL‐6, TNF‐α, and TGF‐β induced by cigarette smoke exposure, reduced the number of inflammatory cells in the bronchoalveolar lavage fluid, and alleviated the severity of cigarette smoke‐induced emphysema. Mechanistically, RLD treatment prevented disease through downregulation of phosphorylated‐ERK and Nrf2 expression, which regulates the production of proinflammatory cytokines. RLD treatment exerted a dramatic therapeutic effect on COPD. This study revealed a mechanism that RLD functions on the regulation of ERK signalling to inhibit inflammation.

The Role of Vascular Endothelial Growth Factor in Small-airway Remodelling in a Rat Model of Chronic Obstructive Pulmonary Disease

Small-airway remodelling is one of the most remarkable pathological features of chronic obstructive pulmonary disease (COPD), in which angiogenesis plays a critical role that contributes to disease progression. The endothelial cell-specific mitogen vascular endothelial growth factor (VEGF), as well as its receptors, VEGFR1, VEGFR2, are thought to be the major mediators of pathological angiogenesis, and sunitinib exhibits anti-angiogenesis property through VEGF blockage and has been widely used to treat various cancers. In our study, Sprague-Dawley rats were subjected to lipopolysaccharide (LPS) injection and cigarette smoke (CS) inhalation to induce COPD, following sunitinib administration was conducted. Haematoxylin-eosin, Masson staining and immunostaining analysis were used to evaluate the pathological changes; quantitative real-time PCR and enzyme-linked immunosorbent assay were performed to provide more compelling data on the function of VEGF, VEGFR1, VEGFR2 in angiogenesis. Sunitinib treatment was associated with less angiogenesis in small-airway remodelling with a slightly disordered lung architecture, and lower expression level of VEGF, VEGFR1, VEGFR2. Overall, our results indicate that VEGF is a vital important factor that contributes to the small-airway remodelling in a rat model of COPD through promoting angiogenesis, which mainly depend on the specific binding between VEGF and VEGFR1 and can be effectively attenuated by sunitinib.

The influence of intestine-based treatment using Xuan Bai Cheng Qi Tang on the concentration of trace elements in the main organs of COPD rats

ObjectiveTo test two theories from traditional Chinese medicine: “exterior–interior relationship between the lung and large intestine” and “treating from the intestine principle for lung disorders”. The influence of intestine-based treatment using Xuan Bai Cheng Qi Tang (XBCQT) on the concentration of three trace elements – copper (Cu), zinc (Zn), and manganese (Mn) – was observed in the tissues of the lung, small intestine, large intestine, and stomach of rats suffering from chronic obstructive pulmonary disease (COPD). MethodsThirty-five male Wistar rats were divided randomly and equally into five groups: control; model; Fei treatment (A); Chang treatment (B); and Fei–Chang treatment (C). A rat model of COPD was prepared by tracheal injection of lipopolysaccharide plus exposure to cigarette smoke. Treatments with medicinal herbs started day-22 of administration and exposure to cigarette smoke for 7 days. The control group and model group were administered physiologic (0.9%) saline solution via the stomach. After 7 days of intervention, the tissues of the lung, small intestine, large intestine, and stomach were removed. Inductively coupled plasma-atomic emission spectroscopy was used to detect the levels of Cu, Zn, and Mn in those tissues. ResultsCompared with the control group, the Cu concentration in the tissues of the small intestine, large intestine, and stomach increased significantly in the model group (P < .05); the Mn concentration in the tissues of the lung, large intestine, and stomach increased significantly in the model group (P < .05); the Zn concentration in the tissues of the lung and large intestine decreased significantly in the model group (P < .05).In comparison of the model group: the Cu concentration in the tissues of the lung and large intestine decreased significantly in the B group (P < .05); the Mn concentration in the tissues of the lung, small intestine, and large intestine decreased significantly in the B group (P < .05); the Zn concentration in the tissues of the lung, small intestine, and large intestine increased significantly in the B group (P < .05).For the A group versus C group comparison, the Zn concentration in the tissues of the small intestine and stomach increased significantly in the latter (P < .05). ConclusionThis study showed that “treating from the intestine” using Xuan Bai Cheng Qi Tang and its modified formulae can regulate the concentration of trace elements in the main organs of COPD rats. This may be one of the mechanisms for intestine-based treatment for COPD.

Curcumin ameliorates alveolar epithelial injury in a rat model of chronic obstructive pulmonary disease

AimsTo investigate the effects of curcumin on alveolar epithelial injury in a rat model of chronic obstructive pulmonary disease (COPD) and its potential mechanism. Main methodsThe rat COPD model was established by cigarette smoke exposure combined with intratracheal administration of lipopolysaccharide. Thirty-eight male Sprague-Dawley rats were randomly divided into four groups: control, COPD model, COPD with curcumin and COPD with solvent groups. Neutrophil and macrophage infiltration in bronchoalveolar lavage fluid (BALF) was evaluated, and the levels of IL-6, IL-8 and TNF-α in BALF and serum were determined by ELISA. Histopathological examination and TUNEL staining were used to assess the alveolar epithelial injury. The protein expression of p66Shc and p-p66Shc in the lung tissues was determined by immunohistochemistry and western blot. Key findingsCurcumin significantly decreased the numbers of total cells, neutrophils and macrophages in BALF from COPD rats. In addition, the levels of IL-6, IL-8 and TNF-α in BALF and serum of COPD rats were significantly decreased after treatment with curcumin. Moreover, curcumin ameliorated emphysema and ultrastructural damage of alveolar epithelial cells in COPD rats. The apoptosis index of alveolar epithelial cells in the COPD with curcumin group was significantly lower than that in the COPD model group. Furthermore, the protein expression of p66Shc and p-p66Shc in alveolar epithelia was significantly decreased in the COPD with curcumin group compared with COPD model group. SignificanceCurcumin attenuates alveolar epithelial injury in COPD rats, which may be partially due to the down-regulation of p66Shc.

Effects of an early intervention using human amniotic epithelial cells in a COPD rat model

The study aimed to investigate the effect of an early intervention using human amniotic epithelial cell (hAEC) in a rat model of chronic obstructive pulmonary disease (COPD). Twenty-four specific pathogen-free Wistar rats were randomized to the control, COPD, and COPD+hAEC groups. COPD was established by intratracheal LPS injection combined with smoke fumigation over 30days. On the first day of model establishment rats in the AEC group also received intratracheal instillation of 500,000 hAECs isolated from the placenta of healthy donors. The mean linear intercept (MLI) and mean alveolar number (MAN) were used to assess the degree of lung emphysema. IL-8 was measured using a radioimmunoassay, surfactant protein D (SP-D) was measured by ELISA, and matrix metalloproteinase (MMP)2 and MMP8 expression was assessed by PCR. Smoke fumigation combined to LPS injection successfully established a COPD rat model with significant emphysema and airway inflammation, elevated MLI and MAN, elevated systemic and lung tissue levels of IL-8 and SP-D (P<0.05), and high expression of MMP2 and MMP8. Rats in the COPD+hAEC group exhibited alleviated lung damage, MLI and MAN (P<0.05), reduced systemic and lung tissue levels of IL-8 and SP-D (P<0.05) and MMP2 and MMP8 expression (P<0.05). Early intervention using hAECs could delay disease progression in rats with COPD.

Anti-inflammatory effect of Yu-Ping-Feng-San via TGF-β1 signaling suppression in rat model of COPD.

Yu-Ping-Feng-San (YPFS) is a classical traditional Chinese medicine that is widely used for treatment of the diseases in respiratory systems, including chronic obstructive pulmonary disease (COPD) recognized as chronic inflammatory disease. However, the molecular mechanism remains unclear. Here we detected the factors involved in transforming growth factor beta 1 (TGF-β1)/Smad2 signaling pathway and inflammatory cytokines, to clarify whether YPFS could attenuate inflammatory response dependent on TGF-β1/Smad2 signaling in COPD rats or cigarette smoke extract (CSE)-treated human bronchial epithelial (Beas-2B) cells. The COPD rat model was established by exposure to cigarette smoke and intratracheal instillation of lipopolysaccharide, YPFS was administered to the animals. The efficacy of YPFS was evaluated by comparing the severity of pulmonary pathological damage, pro-inflammation cytokines, collagen related genes and the activation of TGF-β1/Smad2 signaling pathway. Furthermore, CSE-treated cells were employed to confirm whether the effect of YPFS was dependent on the TGF-β1/Smad2 signaling via knockdown Smad2 (Si-RNA), or pretreatment with the inhibitor of TGF-β1. Administration of YPFS effectively alleviated injury of lung, suppressed releasing of pro-inflammatory cytokines and collagen deposition in COPD animals (P<0.05), whereas exogenous TGF-β1 promoted releasing of IL-1β, IL-6, TNFα (P<0.05). Administration YPFS reduced inflammatory response significantly, also down-regulated TGF-β1/Smad2 signaling in vivo and in vitro. Unexpectedly, knockdown Smad2 or inhibition of TGF-β1 abolished anti-inflammatory effect of YPFS in CSE-treated cells. YPFS accomplished anti-inflammatory effects mainly by suppressing phosphorylation of Smad2, TGF-β1/Smad2 signaling pathway was required for YPFS-mediated anti-inflammation in COPD rats or CSE-treated Beas-2B cells.

Bufei Yishen granules combined with acupoint sticking therapy suppress oxidative stress in chronic obstructive pulmonary disease rats: Via regulating peroxisome proliferator-activated receptor-gamma signaling

Ethnopharmacological relevanceTraditional Chinese medicine (TCM) is clinically used under the guidance of its unique theory system. Bufei Yishen (BY) granules, an oral Chinese herbal formula, is confirmed effective for treating the syndrome of lung-kidney qi deficiency in chronic obstructive pulmonary disease (COPD) patients. Shu-Fei Tie ointment is another prescription for acupoint sticking (AS) therapy based on the theory of treating an internal disease by external treatment on proper acupoints. The beneficial effects of BY granules combined with Shu-Fei Tie have been proved in previous clinical trials. However, the underlying mechanism remains unclear. The present study was initiated to explore the antioxidative mechanism of the integrated therapy of BY granules and acupoint sticking via regulating by peroxisome proliferator activated receptor-gamma (PPARγ) signaling in a cigarette-smoke/bacterial exposure induced COPD rat model. Materials and methodsRats were randomized into Control, Model, BY, AS, BY+AS and aminophylline (APL) groups. COPD rats were induced by cigarette-smoke and bacterial exposures, and were administrated with normal saline, BY granules, AS, BY+AS or aminophylline from week 9 and sacrificed at week 20. Activity of superoxide dismutase (SOD) and levels of methane dicarboxylic aldehyde (MDA) in peripheral blood and bronchoalveolar lavage fluid (BALF) were determined by hydroxylamine and thiobarbituric acid methods. The gene and protein expressions of PPARγ in the lung tissues were analyzed by quantitative polymerase chain reaction and western blot. ResultsSerum and BALF SOD decreased significantly in Model group (P<0.01), while MDA increased (P<0.01). Compared to COPD rats, serum SOD was higher in all treatment groups (P<0.01), and BALF SOD was higher in BY and BY+AS groups (P<0.01); serum and BALF MDA was lower in all treatment groups (P<0.01). Serum and BALF SOD was higher in BY+AS group than in AS group, while MDA was lower (P<0.05). BALF SOD increased in BY+AS group compared with APL group, while MDA decreased (P<0.05). PPARγ mRNA and protein and the phosphorylation of PPARγ (p-PPARγ) decreased in COPD rats (P<0.01), and increased in all treatment groups (P<0.01). PPARγ mRNA was higher in BY+AS group than in AS group (P<0.05), PPARγ and p-PPARγ were higher in BY+AS group than in AS and APL groups (P<0.05, P<0.01); PPARγ protein was higher in BY group than in APL group (P<0.05). ConclusionBufei Yishen granules, Shu-Fei Tie and their combination have beneficial effects in stable COPD, and can attenuate the oxidative stress, and the activation of PPARγ signaling might be involved in the underlying mechanisms, but there are no obvious synergistic effect of Bufei Yishen granules and Shu-Fei Tie.

Mechanism of intestinal mucosal barrier dysfunction in a rat model of chronic obstructive pulmonary disease: An observational study.

The aim of the present study was to investigate intestinal mucosal barrier dysfunction in a rat model of chronic obstructive pulmonary disease (COPD). Male Sprague Dawley rats (n=40) were evenly randomized into control and COPD groups and the COPD model was established by regulated exposure to cigarette smoke for 6 months. Histopathological changes of the lung and intestinal tissues were detected by hematoxylin and eosin staining. Expression of the tight junction proteins occludin and zona occludens-1 (ZO-1) in the intestinal tissues were analyzed by western blotting, serum diamine oxidase (DAO) activity was detected by spectrophotometry, the urinary lactulose to mannitol ratio (L/M) was evaluated by high performance liquid chromatography, and intestinal tissue secretion of tumor necrosis factor (TNF)-α, interferon (IFN)-γ and interleukin (IL)-8 were detected by ELISA. Lung histopathology revealed thinned alveolar walls, ruptured alveolar septa, enlarged and deformed alveoli, and the formation of bullae and emphysema due to alveolar fusion in the COPD group, while intestinal histopathology indicated clearly swollen intestines with darkened and gray mucosa, neutrophil infiltration of the intestinal mucosal and regional epithelial shedding. The occludin and ZO-1 expression levels were significantly lower in the COPD group compared with those in the corresponding control group (P<0.05), while the urinary L/M ratio was significantly higher (P<0.05). Furthermore, the serum DAO activity and secretion of TNF-α, IFN-γ and IL-8 in the intestinal tissues were significantly higher in the COPD group than in the control group (each P<0.05). Dysfunctional and structural changes were observed in the intestinal mucosal barrier in COPD model rats, which may be associated with the increased intestinal inflammatory responses.

A mucoactive drug carbocisteine ameliorates steroid resistance in rat COPD model

Steroid insensitivity has been commonly found in chronic obstructive pulmonary disease (COPD) patients, which is mediated by the reduction of histone deacetylase (HDAC) 2. Here we aimed to establish a steroid resistant model on experimental COPD rats and evaluate the effect of carbocisteine (S-CMC), a mucoactive drug. Exposure to cigarette smoke (CS) caused marked pathological features of COPD which are insensitive to DEX associated with the down-regulation of HDAC2 expression/activity. The DEX insensitivity observed in COPD featured rats was improved by S-CMC in the aspects of inhibiting chronic lung inflammation (total and differential inflammatory cell counts, inflammatory cytokines release and inflammatory cells infiltration); ameliorating airway remodeling (thickness of airway epithelium and smooth muscle, airway fibrosis, and the level of α-SMA and TGF-β1); improving emphysema (emphysema index D2, level of MMP-9 in BALF and the expression of alpha-1 antitrypsin) and preventing impairments of lung function (PEF, IP and IP-slope). Simultaneously, down-regulation of HDAC2 expression/activity was ameliorated by S-CMC treatment. These results indicate that the rat COPD model with steroid resistance was established by active smoking in a short time frame and demonstrate that the failure of steroid therapy can be restored by S-CMC accompanied by increasing HDAC2 expression/activity, providing additional evidence that S-CMC might be used for GC resistance in COPD.

Susceptibility to Aspergillus Infections in Rats with Chronic Obstructive Pulmonary Disease via Deficiency Function of Alveolar Macrophages and Impaired Activation of TLR2.

Clinical evidence indicates that patients with severe chronic obstructive pulmonary disease (COPD) are more susceptible to Aspergillus. However, the exact mechanisms underlying this effect are not known. In this study, we used cigarette smoke exposure to generate COPD rat model. colony-forming units (CFU) count assessment and phagocytosis were applied to evaluate the defense function of COPD rats against Aspergillus challenge. ELISA, western blotting, and GST-Rac1 pull-down assays were conducted to determine the expressions of cytokines and TLR2-associated signaling pathway. Our data showed that Aspergillus burdens increased, phagocytosis of Aspergillus as well as the expressions of inflammatory cytokines from alveolar macrophages (AMs) were impaired in COPD rats compared with normal rats. Though TLR2 signaling-related proteins were induced in response to the stimulation of Aspergillus or Pam3csk4 (TLR2 agonist), the activation of TLR2-associated signaling pathway was apparently interfered in rats with COPD, compared to that in normal rats. Taken together, our study demonstrated that COPD caused the deficiency of AMs function and impaired the activation of TLR2/PI3K/Rac 1 signaling pathway, leading to invasion of Aspergillus infection, which also provides a future basis for the infection control in COPD patients.

Long-Term Effects of Acupuncture Treatment on Airway Smooth Muscle in a Rat Model of Smoke-Induced Chronic Obstructive Pulmonary Disease

BackgroundChronic obstructive pulmonary disease (COPD) is one of the most common lung diseases. It is a chronic inflammatory process characterised by airway obstruction and progressive lung inflammation, associated with difficulty breathing and insensitivity to corticosteroid therapy. Although there is some preliminary evidence to suggest a beneficial effect of acupuncture on COPD, its mechanism of action has not been investigated. Our aim was to examine the anti-inflammatory effects of acupuncture in a rat model of COPD induced by exposure to cigarette smoke (CS).MethodsSixty Sprague–Dawley rats were exposed to the smoke of 15 cigarettes for 1 h/day, 6 days/week for 3 months to induce COPD and treated with acupuncture at BL13 (Feishu), BL23 (Shenshu) and Dingchuan (COPD+Acupuncture, n=15), sham acupuncture (COPD+Sham, n=15) or left untreated (n=15). Exposed rats were compared with controls not exposed to CS (control, n=15). Pulmonary function was measured, and tumour necrosis factor-α (TNF-α) and interleukin-8 (IL-8) levels were determined in bronchoalveolar lavage fluid by ELISA. Histone deacetylase 2 (HDAC2) protein and mRNA expression were examined in lung tissue and in bronchus.ResultsAcupuncture treatment appeared to protect pulmonary function and reduce the COPD-induced inflammatory response by decreasing cell inflammation and the production of TNF-α and IL-8. Acupuncture also enhanced HDAC2 mRNA and protein expression, suggesting a possible direct effect on protein structure through post-translational modifications.ConclusionsOur results suggest that acupuncture regulates inflammatory cytokines and contributes to lung protection in a rat model of smoke-induced COPD by modulating HDAC2.

Pinellia ternata Attenuates Mucus Secretion and Airway Inflammation after Inhaled Corticosteroid Withdrawal in COPD Rats.

Inhaled corticosteroids (ICS) are widely used to manage chronic obstructive pulmonary disease (COPD). However, withdrawal of ICS generally causes various adverse effects, warranting careful management of the ICS withdrawal. Pinellia ternata, a traditional Chinese herbal medicine, has been used to treat respiratory diseases in China for centuries. Here, we investigated its role in antagonizing ICS withdrawal-induced side effects, and explored the underlying mechanisms. The rat COPD model was established using a combination of passive cigarette smoking and intratracheal instillation of lipopolysaccharide (LPS). COPD rats were treated with saline or budesonide inhalation, or with budesonide inhalation followed by saline inhalation or Pinellia ternata gavage. The number of goblet cells and the level of mucin 5AC (MUC5AC) were enhanced by budesonide withdrawal. Pinellia ternata treatment significantly blocked these effects. Further, Pinellia ternata treatment reversed budesonide withdrawal-induced increase of interleukin 1[Formula: see text] (IL-1[Formula: see text] and tumor necrosis factor [Formula: see text] (TNF-[Formula: see text]) levels in bronchoalveolar lavage fluid (BALF). Extracellular signal-regulated kinase (ERK), but neither p38 nor c-Jun N-terminal kinase (JNK), was activated by budesonide withdrawal, and the activation was blocked by Pinellia ternata treatment. The MUC5AC expression was positively correlated with goblet cell number, IL-1[Formula: see text] and TNF-[Formula: see text] levels, and ERK activity. Pinellia ternata treatment protected the airway from ICS withdrawal-induced mucus hypersecretion and airway inflammation by inhibiting ERK activation. Pinellia ternata treatment may represent a novel therapeutic strategy to prevent ICS withdrawal-induced side effects in COPD patients.

Effects of Bufei Yishen Granules Combined with Acupoint Sticking Therapy on Pulmonary Surfactant Proteins in Chronic Obstructive Pulmonary Disease Rats.

Our previous studies have demonstrated the beneficial effects of Bufei Yishen granules combined with acupoint sticking therapy (the integrated therapy) in chronic obstructive pulmonary disease (COPD), but the underlying mechanism remains unclear. Dysfunction of pulmonary surfactant proteins (SPs, including SP-A, SP-B, SP-C, and SP-D) may be included in pathophysiology of COPD. This study aimed to explore the mechanism of the integrated therapy on SPs. COPD rat models were established. The treatment groups received Bufei Yishen granules or acupoint sticking or their combination. Using aminophylline as a positive control drug. The levels of SPs in serum, BALF, and lung were measured. The results showed that the integrated therapy markedly reduced the levels of SPs in serum and increased these indicators in the lung. The integrated therapy was better than aminophylline in reducing the levels of SPs and was better than Bufei Yishen granules in reducing SP-A, SP-C, and SP-D in serum. The integrated therapy was better than aminophylline and Bufei Yishen granules in increasing SP-A, SP-B, and SP-D mRNA in the lung. SP-A and SP-D in BALF were positively correlated with PEF and EF50. The levels of SPs are associated with airway limitation. The beneficial effects of the integrated therapy may be involved in regulating pulmonary surfactant proteins.

Upregulation of ICAM-1 and IL-1β protein expression promotes lung injury in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a devastating lung disorder characterized by sustained airway flow restriction that is not fully reversible. The precise pathogenic mechanisms are unknown, but it is clear that cigarette smoking and chronic inflammatory stimulation are the major causes of COPD. Lung inflammation associated with COPD involves multiple cytokines, aggregation, and activation of neutrophils in the airway and lung tissue, and release of proteases and oxygen free radicals. In this study, a rat model of COPD was established by daily cigarette smoke exposure plus endotoxin treatment (the experimental group). Respiratory curves were recorded by the BL-420 biological signal collecting and processing system. Furthermore, the contents of inflammatory mediators, intercellular adhesion molecular (ICAM)-1 and interleukin (IL)-1β, in bronchoalveolar lavage fluid (BALF) were determined by enzyme linked immunosorbent assay for experimental, smoke-exposed only (control), and untreated (blank) rat groups. Protein expression levels of ICAM-1 and IL-1β in the lung tissue were also compared among groups by the immunohistochemical streptavidin-peroxidase method. The COPD model rats exhibited severe dyspnea and lung inflammation as evidenced by significantly prolonged expiratory duration, higher respiratory rate, elevated ICAM-1 and IL-1β in BALF, and higher ICAM-1 and IL-1β protein expression in lung tissue compared to control and blank group rats. Chronic cigarette smoke exposure plus endotoxin is a feasible and reliable model of COPD that recapitulates many clinical signs and pathogenic responses. ICAM-1 and IL-1β upregulation are possible early contributors to COPD-associated inflammatory lung injury.