Bacterial interactome disturbance in chronic obstructive pulmonary disease clinical stability and exacerbations.

RATIONALE: Our understanding of airway dysbiosis in chronic obstructive pulmonary disease (COPD) remains incomplete, which may be improved by unraveling the complexity in microbial interactome. OBJECTIVES: To characterize reproducible features of airway bacterial interactome in COPD at clinical stability and during exacerbation, and evaluate their associations with disease phenotypes. METHODS: We performed weighted ensemble-based co-occurrence network analysis of 1742 sputum microbiomes from published and new microbiome datasets, comprising two case-control studies of stable COPD versus healthy control, two studies of COPD stability versus exacerbation, and one study with exacerbation-recovery time series data. RESULTS: Patients with COPD had reproducibly lower degree of negative bacterial interactions, i.e. total number of negative interactions as a proportion of total interactions, in their airway microbiome compared with healthy controls. Evaluation of the Haemophilus interactome showed that the antagonistic interaction networks of this established pathogen rather than its abundance consistently changed in COPD. Interactome dynamic analysis revealed reproducibly reduced antagonistic interactions but not diversity loss during COPD exacerbation, which recovered after treatment. In phenotypic analysis, unsupervised network clustering showed that loss of antagonistic interactions was associated with worse clinical symptoms (dyspnea), poorer lung function, exaggerated neutrophilic inflammation, and higher exacerbation risk. Furthermore, the frequent exacerbators (≥ 2 exacerbations per year) had significantly reduced antagonistic bacterial interactions while exhibiting subtle compositional changes in their airway microbiota. CONCLUSIONS: Bacterial interactome disturbance characterized by reduced antagonistic interactions, rather than change in pathogen abundance or diversity, is a reproducible feature of airway dysbiosis in COPD clinical stability and exacerbations, which suggests that we may target interactome rather than pathogen alone for disease treatment.

The effect of low-dose corticosteroids and theophylline on the risk of acute exacerbations of COPD: the TASCS randomised controlled trial.

BACKGROUND: The highest burden of chronic obstructive pulmonary disease (COPD) occurs in low- and middle-income countries. Low-cost oral medications, if effective, could enable affordable, accessible COPD treatment. METHODS: In this randomised, three-arm, double-blind, double-dummy, placebo-controlled study conducted in 37 centres in China, symptomatic patients with moderate to very severe COPD were randomised 1:1:1 to placebo twice daily plus placebo once daily, low-dose theophylline 100 mg twice daily plus placebo once daily or low-dose theophylline 100 mg twice daily plus low-dose oral prednisone 5 mg once daily for 48 weeks. The primary end-point was annualised exacerbation rate. RESULTS: 1670 subjects were randomised and 1242 completed the study (1142 with acceptable data at week 48). Subjects (75.7% male) had a mean age of 64.4 years, with mean±sd baseline post-bronchodilator forced expiratory volume in 1 s (FEV1) 1.1±0.4 L (42.2% predicted) and St George's Respiratory Questionnaire (SGRQ) score 45.8±20.1. There were negligible differences between annualised exacerbation rates across the three treatments: 0.89 (95% CI 0.78-1.02) on theophylline plus prednisone, 0.86 (95% CI 0.75-0.99) on theophylline plus placebo and 1.00 (95% CI 0.87-1.14) on placebo. The rate ratio for theophylline plus prednisone versus pooled theophylline plus placebo and placebo was 0.96 (95% CI 0.83-1.12), for theophylline plus placebo versus placebo was 0.87 (95% CI 0.73-1.03; p=0.101) and for theophylline plus prednisone versus placebo was 0.90 (95% CI 0.76-1.06; p=0.201). Secondary outcomes of hospitalisations, FEV1, SGRQ and COPD Assessment Test score showed no statistically significant difference between treatment arms. Serious adverse events other than exacerbations were <2% and did not differ between treatment arms. CONCLUSIONS: Low-dose theophylline alone or in combination with prednisone did not reduce exacerbation rates or clinically important secondary end-points compared with placebo.

Mitochondrial Damage-Associated Molecular Patterns Exacerbate Lung Fluid Imbalance Via the Formyl Peptide Receptor-1 Signaling Pathway in Acute Lung Injury.

OBJECTIVES: To investigate the effect of mitochondrial damage-associated molecular patterns on the lung fluid homeostasis in experimental acute lung injury. DESIGN: Experimental study. SETTING: Research laboratory. SUBJECTS: Patients with acute respiratory distress syndrome and control subjects, wild-type C57BL/6 and formyl peptide receptor-1 gene knockout mice, and primary rat alveolar epithelial type II cells. INTERVENTIONS: Samples of bronchoalveolar lavage fluid and serum were obtained from patients and control subjects. Mice were intratracheally instilled with lipopolysaccharide and mitochondrial damage-associated molecular patterns. The primary rat alveolar epithelial type II cells were isolated and incubated with mitochondrial damage-associated molecular patterns. MEASUREMENTS AND MAIN RESULTS: Patients were divided into direct (pulmonary) and indirect (extrapulmonary) injury groups based on etiology. The release of mitochondrial peptide nicotinamide adenine dinucleotide dehydrogenase 1 in both bronchoalveolar lavage fluid and serum was induced in patients and was associated with etiology. In the lipopolysaccharide-induced lung injury, administration of mitochondrial damage-associated molecular patterns exacerbated the lung fluid imbalance, which was mitigated in formyl peptide receptor-1 knockout mice. Proteomic analysis of mouse lung tissues revealed the involvement of ion channels and tight junction proteins in this process. Treatment with mitochondrial damage-associated molecular patterns decreased the expression of epithelial sodium channel α, zonula occludens-1, and occludin via the formyl peptide receptor-1/p38 pathway in the primary rat alveolar epithelial type II cells. CONCLUSIONS: Mitochondrial damage-associated molecular patterns exacerbate lung fluid imbalance in the experimental acute lung injury model through formyl peptide receptor-1 signaling, the inhibition of which may prevent exacerbation of lung fluid imbalance induced by mitochondrial damage-associated molecular patterns. Thus, formyl peptide receptor-1 is a potential therapeutic target for acute respiratory distress syndrome.

[Resveratrol inhibits hypoxia-induced oxidative stress and proliferation in pulmonary artery smooth muscle cells through the HIF-1α/NOX4/ROS signaling pathway].

The purpose of the present study was to determine the effects of resveratrol on hypoxia-induced oxidative stress and proliferation in pulmonary artery smooth muscle cells (PASMCs) and the underlying mechanism. Primary rat PASMCs were isolated and cultured in vitro and pretreated with different concentrations of resveratrol (10, 20, and 40 µmol/L) or the NADPH oxidase (NOX) inhibitor VAS2870 (10 µmol/L) for 0.5 h. The cells were then cultured under normoxia (21% O2, 5% CO2) or hypoxia (2% O2, 5% CO2) for 24 h. The proliferation of cells was measured using the CCK-8 method and the expression of proliferating cell nuclear antigen (PCNA). The production of reactive oxygen species (ROS) was detected by DCFH-DA. The expression of rat NOX1, NOX4 and hypoxia inducible factor 1α (HIF-1α) was detected by real-time RT-PCR and Western blotting assays. The related signaling pathways were determined using the small interference RNAs (siRNAs) specifically targeting Hif-1α and Nox4. The results showed that resveratrol and VAS2870 significantly inhibited hypoxia-induced cell proliferation and ROS production in rat PASMCs. Resveratrol also effectively prevented hypoxia-induced increase of HIF-1α protein levels and NOX4 up-regulation, but had little effect on NOX1. After the knocking down of Hif-1α or Nox4 with siRNAs, hypoxia-induced cell proliferation and ROS accumulation were significantly decreased, and both were further inhibited by resveratrol treatment. These results suggest that resveratrol inhibits hypoxia-induced oxidative stress and cell proliferation in rat PASMCs possibly through blocking the HIF-1α/NOX4/ROS pathway.

Mitochondrial peptides cause proinflammatory responses in the alveolar epithelium via FPR-1, MAPKs, and AKT: a potential mechanism involved in acute lung injury.

Acute lung injury (ALI) is characterized by alveolar epithelial damage and uncontrolled pulmonary inflammation. Mitochondrial damage-associated molecular patterns (DAMPs), including mitochondrial peptides [ N-formyl peptides (NFPs)], are released during cell injury and death and induce inflammation by unclear mechanisms. In this study, we have investigated the role of mitochondrial DAMPs (MTDs), especially NFPs, in alveolar epithelial injury and lung inflammation. In murine models of ALI, high levels of mitochondrial NADH dehydrogenase 1 in bronchoalveolar lavage fluid (BALF) were associated with lung injury scores and increased formyl peptide receptor (FPR)-1 expression in the alveolar epithelium. Cyclosporin H (CsH), a specific inhibitor of FPR1, inhibited lung inflammation in the ALI models. Both MTDs and NFPs upon intratracheal challenge caused accumulation of neutrophils into the alveolar space with elevated BALF levels of mouse chemokine KC, interleukin-1ß, and nitric oxide and increased pulmonary FPR-1 levels. CsH significantly attenuated MTDs or NFP-induced inflammatory lung injury and activation of MAPK and AKT pathways. FPR1 expression was present in rat primary alveolar epithelial type II cells (AECIIs) and was increased by MTDs. CsH inhibited MTDs or NFP-induced CINC-1/IL-8 release and phosphorylation of p38, JNK, and AKT in rat AECII and human cell line A549. Inhibitors of MAPKs and AKT also suppressed MTD-induced IL-8 release and NF-κB activation. Collectively, our data indicate an important role of the alveolar epithelium in initiating immune responses to MTDs released during ALI. The potential mechanism may involve increase of IL-8 production in MTD-activated AECII through FPR-1 and its downstream MAPKs, AKT, and NF-κB pathways.

WNT/ß-catenin signaling regulates cigarette smoke-induced airway inflammation via the PPARδ/p38 pathway.

The mechanisms of WNT/ß-catenin signaling involved in airway inflammation of chronic obstructive pulmonary disease (COPD) remain unknown, although recent observations have suggested an important contribution of the pathway in pulmonary parenchymal tissue repair and airway epithelium differentiation. We investigated the role of WNT/ß-catenin signaling in cigarette smoke (CS)-related airway inflammation using patient lung tissues, human bronchial epithelial cells (16HBECs), and mouse models. Reduced activity of WNT/ß-catenin signaling was observed in the airway epithelium of smokers with or without COPD. The mRNA expression of WNT transcription factor TCF4 negatively correlated with the pack year. The mRNA levels of WNT receptor FZD4 negatively correlated with the mRNA levels of IL-1ß. CS exposure decreased the activity of WNT/ß-catenin signaling in both 16HBECs and mice. In vitro studies demonstrated the upregulation of inflammatory cytokines TNF-α and IL-1ß secretion induced by CS extract (CSE) could be attenuated by ß-catenin activator SB216763 and be exacerbated by ß-catenin small-interfering RNA (siRNA), respectively. Furthermore, the decrease in the expression of peroxisome proliferator-activated receptor (PPARδ) induced by CSE stimulation could be rescued by SB216763. SB216763 also attenuated the upregulation of phosphorylated p38 mitogen-activated protein kinase (MAPK) stimulated by CSE. Both PPARδ agonist and p38 MAPK inhibitor could suppress the TNF-α and IL-1ß release induced by CSE treatment. In addition, PPARδ activation could abolish ß-catenin siRNA-mediated aggravation of phosphorylated p38 MAPK in response to CSE. Finally, SB216763 treatment significantly ameliorated peribronchial inflammatory cell infiltration, leukocyte influx, and the release of TNF-α and IL-1ß in the bronchoalveolar lavage fluid of CS-exposed mice. Taken together, our findings indicate that the reduced activity of WNT/ß-catenin signaling induced by CS may promote inflammatory cytokine production in airway epithelium and have an essential role in airway inflammation in COPD by PPARδ/p38 MAPK pathway.

[Immune mediated inflammatory pathogenesis and assessment of disease activity in rheumatoid arthritis].

Rheumatoid arthritis (RA) is a systemic chronic inflammatory disease with synovitis and pannus formation as its basic pathologic features. Immune mediated inflammation is the core event in the occurrence and development of RA, but the inflammatory mechanism in RA pathogenesis remains unclear and needs more research to be illustrated. T cells, B cells, proinflammatory cytokine network and chemokines were confirmed to be involved in the process. In addition, the cells related to the structure of bone and joint, such as synovial cells, osteoblasts and osteoclasts, also participate in the inflammation progression of RA acting as the effector cells of immune regulation. The severity of inflammation of RA is closely related to disease activity. There are many kinds of tools for the assessment of disease activity of RA, The rationale use and optimization of these assessment tools will be helpful to make the treatment decision and improve the prognosis of RA.

Matrix metalloproteinase-9 activates TGF-ß and stimulates fibroblast contraction of collagen gels.

Matrix metalloproteinase-9 (MMP-9) is a matrix-degrading enzyme implicated in many biological processes, including inflammation. It is produced by many cells, including fibroblasts. When cultured in three-dimensional (3D) collagen gels, fibroblasts contract the surrounding matrix, a function that is thought to model the contraction that characterizes both normal wound repair and fibrosis. The current study was designed to evaluate the role of endogenously produced MMP-9 in fibroblast contraction of 3D collagen gels. Fibroblasts from mice lacking expression of MMP-9 and human lung fibroblasts (HFL-1) transfected with MMP-9 small-interfering RNA (siRNA) were used. Fibroblasts were cast into type I collagen gels and floated in culture medium with or without transforming growth factor (TGF)-ß1 for 5 days. Gel size was determined daily using an image analysis system. Gels made from MMP-9 siRNA-treated human fibroblasts contracted less than control fibroblasts, as did fibroblasts incubated with a nonspecific MMP inhibitor. Similarly, fibroblasts cultured from MMP-9-deficient mice contracted gels less than did fibroblasts from control mice. Transfection of the MMP-9-deficient murine fibroblasts with a vector expressing murine MMP-9 restored contractile activity to MMP-9-deficient fibroblasts. Inhibition of MMP-9 reduced active TGF-ß1 and reduced several TGF-ß1-driven responses, including activity of a Smad3 reporter gene and production of fibronectin. Because TGF-ß1 also drives fibroblast gel contraction, this suggests the mechanism for MMP-9 regulation of contraction is through the generation of active TGF-ß1. This study provides direct evidence that endogenously produced MMP-9 has a role in regulation of tissue contraction of 3D collagen gels mediated by fibroblasts.

Emodin ameliorates LPS-induced acute lung injury, involving the inactivation of NF-κB in mice.

Acute lung injury (ALI) and its severe manifestation of acute respiratory distress syndrome (ARDS) are well-known illnesses. Uncontrolled and self-amplified pulmonary inflammation lies at the center of the pathology of this disease. Emodin, the bio-active coxund of herb Radix rhizoma Rhei, shows potent anti-inflammatory properties through inactivation of nuclear factor-κB (NF-κB). The aim of this study was to evaluate the effect of emodin on lipopolysaccharide (LPS)-induced ALI in mice, and its potential bio-mechanism. In our study, BALB/c mice were stimulated with LPS to induce ALI. After 72 h of LPS stimulation, pulmonary pathological changes, lung injury scores, pulmonary edema, myeloperoxidase (MPO) activity, total cells, neutrophils, macrophages, TNF-α, IL-6 and IL-1ß in bronchoalveolar lavage fluid (BALF), and MCP-1 and E-selectin expression were notably attenuated by emodin in mice. Meanwhile, our data also revealed that emodin significantly inhibited the LPS-enhanced the phosphorylation of NF-κB p65 and NF-κB p65 DNA binding activity in lung. Our data indicates that emodin potently inhibits LPS-induced pulmonary inflammation, pulmonary edema and MCP-1 and E-selectin expression, and that these effects were very likely mediated by inactivation of NF-κB in mice. These results suggest a therapeutic potential of emodin as an anti-inflammatory agent for ALI/ARDS treatment.

[Diammonium glycyrrhizinate promotes aquaporin-5 in LPS-induced acute lung injury via inactivation of NF-kappaB].

OBJECTIVE: To determine the therapeutic value and associated mechanism of diammonium glycyrrhizinate (DG) on the expression of AQP-5 in lipapolysacchairides (LPS)-induced acute lung injury in mice. METHODS: Thirty male BALB/c mice were randomly divided into three groups equally: Control, LPS+DG and LPS. HE staining and lung injury score system were used to evaluate the pathological changes in the lung tissues. Wet to dry ratio (W/D) was used to measure the degree of lung edema. RT-PCR and Western blot were obtained to measure AQP-5 expression. Total NF-kappaB p65 and phospho-NF-kappaB p65 (p-NF-kappaB p65) were evaluated by Western blot. RESULTS: After 3 days of LPS intratracheal injection, severe pathological changes, increased W/D, down-regulated AQP-5 expression and increased p-NF-kappaB p65/total NF-kappaB p65 were observed. Compared with mice in the LPS group, mice in the LPS+DG group had more significantly ameliorated pathological changes and increased W/ D, up-regulated AQP-5 expression, and reduced p-NF-kappaB p65/total NF-kappaB p65. CONCLUSION: DG up-regulates AQP-5 in vivo, possibly resulting from inactivation of NF-kappaB.

High-dose N-acetylcysteine in the prevention of COPD exacerbations: rationale and design of the PANTHEON Study.

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation; from a pathophysiological point of view it involves many components, including mucus hypersecretion, oxidative stress and inflammation. N-acetylcysteine (NAC) is a mucolytic agent with antioxidant and anti-inflammatory properties. Long-term efficacy of NAC 600mg/d in COPD is controversial; a dose-effect relationship has been demonstrated, but at present it is not known whether a higher dose provides clinical benefits. The PANTHEON Study is a prospective, ICS stratified, randomized, double-blind, placebo-controlled, parallel-group, multi-center trial designed to assess the efficacy and safety of high-dose (1200 mg/daily) NAC treatment for one year in moderate-to-severe COPD patients. The primary endpoint is the annual exacerbation rate. Secondary endpoints include recurrent exacerbations hazard ratio, time to first exacerbation, as well as quality of life and pulmonary function. The hypothesis, design and methodology are described and baseline characteristics of recruited patients are presented. 1006 COPD patients (444 treated with maintenance ICS, 562 ICS naive, aged 66.27±8.76 yrs, average post-bronchodilator FEV1 48.95±11.80 of predicted) have been randomized at 34 hospitals in China. Final results of this study will provide objective data on the effects of high-dose (1200 mg/daily) long-term NAC treatment in the prevention of COPD exacerbations and other outcome variables.

Ox-LDL-induced TGF-ß1 production in human alveolar epithelial cells: involvement of the Ras/ERK/PLTP pathway.

Oxidized-low density lipoprotein (Ox-LDL) has been shown to play an important role in impaired surfactant metabolism and transforming growth factor-ß1 (TGF-ß1) is a critical mediator in the pathogenesis of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). In this study, we investigated whether Ox-LDL can induce TGF-ß1 protein production, and if so, how it achieves this induction in human alveolar epithelial cells (A549). We show here that Ox-LDL not only caused a dose- and time-dependent up-regulation of TGF-ß1 production, but also increased Smad3 phosphorylation, Ras/extracellular signal-regulated kinase (ERK) activity and phospholipid transfer protein (PLTP) expression in A549 cells. The inhibition of Ras/ERK activity with specific inhibitors significantly suppressed Ox-LDL-induced TGF-ß1 production, Smad3 phosphorylation and PLTP expression. Furthermore, treatment of cells with PLTP siRNA suppressed both TGF-ß1 release and Smad3 activation induced by Ox-LDL, but not the activation of Ras/ERK cascade. Taken together, we provide evidences that induction of TGF-ß1 production and Smad3 phosphorylation by Ox-LDL is mediated by Ras/ERK/PLTP pathway in human alveolar epithelial cells.

Blood Eosinophils in Chinese COPD Participants and Response to Treatment with Combination Low-Dose Theophylline and Prednisone: A Post-Hoc Analysis of the TASCS Trial.

BACKGROUND AND OBJECTIVES: The burden of chronic obstructive pulmonary disease (COPD) disproportionately affects patients in low to middle-income countries. Although the Theophylline and Steroids in COPD Study (TASCS) showed no clinical benefit from administering low-dose theophylline and prednisone in COPD patients compared to placebo, it was hypothesized that those with elevated blood eosinophil counts would receive clinical benefit from the intervention. METHODS: This was a post-hoc analysis of the TASCS dataset - a double-blinded, placebo-controlled trial conducted in patients with moderate-severe COPD in China. Participants were allocated 1:1:1 to low-dose oral theophylline (100mg bd) and prednisone (5mg qd; PrT), theophylline (100mg bd) and prednisone-matched placebo (TP), or double-matched placebo (DP) groups and followed-up for 48 weeks. A baseline count of ≥300 eosinophils/µL blood was categorized as elevated/eosinophilic, and the primary outcome was the annualized moderate-severe exacerbation rate. RESULTS: Of 1487 participants eligible for analysis, 325 (22%) were eosinophilic. These participants were predominantly male (82%), had a mean (SD) age of 64 (±8) years and a predicted forced expiratory volume in 1s (FEV1) of 43% (±16). The annualized moderate-severe exacerbation rate was significantly higher in the PrT group compared to the pooled results of the TP and DP groups (incidence rate ratio = 1.6; ([95% CI 1.06-1.76]) p = 0.016). Changes in spirometry values and reported disease impact scores (St. George's Respiratory Questionnaire and COPD Assessment Test) at week 48 were not significantly different between groups. CONCLUSION: Combination low-dose theophylline and prednisone was associated with a significant increase in the annual moderate-severe exacerbation rate in participants with a blood eosinophil count ≥300 cells/µL compared to placebo.

Effects of formoterol-budesonide on airway remodeling in patients with moderate asthma.

AIM: To evaluate the effect of inhaled formoterol-budesonide on airway remodeling in adult patients with moderate asthma. METHODS: Thirty asthmatic patients and thirty control subjects were enrolled. Asthmatic subjects used inhaled Symbicort 4.5/160 µg twice daily for one year. The effect of formoterol-budesonide on airway remodeling was assessed with comparing high-resolution computer tomography (HRCT) images of asthmatic patients and controls, as well as expression levels of cytokines and growth factors, inflammatory cell count in induced sputum, and airway hyper-responsiveness. RESULTS: The differences in age and gender between the two groups were not significant. However, differences in FVC %pred, FEV(1) %pred, and PC(20) between the two groups were significant. After treatment with formoterol-budesonide, the asthma patients' symptoms were relieved, and their lung function was improved. The WT and WA% of HRCT images in patients with asthma was increased, whereas treatment with formoterol-budesonide caused these values to decrease. The expression of MMP-9, TIMP-1, and TGF-ß(1) in induced sputum samples increased in patients with asthma and decreased dramatically after treatment with formoterol-budesonide. The WT and WA% are correlated with the expression levels of cytokines and growth factors, inflammatory cell count in induced sputum, and airway hyper-responsiveness, while these same values are correlated negatively with FEV(1)/FVC and FEV(1)%. CONCLUSION: Formoterol-budesonide might interfere in chronic inflammation and airway remodeling in asthmatic patients. HRCT can be used to effectively evaluate airway remodeling in asthmatic patients.

[Integripetal rhodiola herb attenuates high altitude-induced pulmonary arterial remodeling and expression of vascular endothelial growth factor in rats].

The aim of this study was to investigate the effect of integripetal rhodiola herb on pulmonary arterial remodeling and expression of vascular endothelial growth factor (VEGF) in high altitude pulmonary hypertension in rats. Fifty healthy male Wistar rats were divided into five groups randomly: Plain control group (LC group), 10-day plateau group (H(10) group), 30-day plateau group (H(30) group), 10-day rhodiola-treated plateau group (R(10) group), and 30-day rhodiola-treated plateau group (R(30) group). Each group included 10 rats. The rats in LC group were kept in Chengdu (500 meters above sea level), and rats in H and R groups were kept in Lhasa (3 700 meters above sea level). The rats in R group were daily treated with integripetal rhodiola herb extract (24%, 10 mL/kg) intragastrically for 10 d or 30 d, while rats in LC and H groups were treated with the same volume of saline. Mean pulmonary arterial pressure (mPAP) was detected via a catheter in the pulmonary artery by pressure waveform monitoring. The ratio value of right ventricle weight to left ventricle plus septum weight [RV/(LV + S)] was measured. The microstructure of pulmonary arterioles was examined by electron microscopy. The expression of VEGF in the lung was investigated using immunohistochemistry. The results showed that mPAP and [RV/(LV + S)] in H(10) group and H(30) group were higher than those in LC group (P < 0.05); but there was no significant difference between H(10) group and R(10) group (P < 0.05); and mPAP and [RV/(LV + S)] in H(30) group were lower than those in H(30) group (P < 0.05). Electron microscopy showed that compared to LC group, arteriolar endothelial cells were arranged in a columnar or palisading form, protruding into the lumen, accompanied with luminal stenosis, irregular internal elastic membrane, and proliferation of vascular smooth muscle cells in H groups, which was more obvious in H(30) group than in H(10) group; while these pathological changes were attenuated in the R groups compared to H groups. The levels of VEGF protein in H groups were also higher than those in LC group (P < 0.05); while the expression of VEGF in R(30) group was lower than that in H(30) group. In summary, the results show that the integripetal rhodiola herb can attenuate high altitude-induced pulmonary arterial remodeling in rats, and the inhibition of VEGF protein expression by rhodiola may be one of the mechanisms.

The Multifaceted Therapeutic Role of N-Acetylcysteine (NAC) in Disorders Characterized by Oxidative Stress.

Oxidative stress, which results in the damage of diverse biological molecules, is a ubiquitous cellular process implicated in the etiology of many illnesses. The sulfhydryl-containing tripeptide glutathione (GSH), which is synthesized and maintained at high concentrations in all cells, is one of the mechanisms by which cells protect themselves from oxidative stress. N-acetylcysteine (NAC), a synthetic derivative of the endogenous amino acid L-cysteine and a precursor of GSH, has been used for several decades as a mucolytic and as an antidote to acetaminophen (paracetamol) poisoning. As a mucolytic, NAC breaks the disulfide bonds of heavily cross-linked mucins, thereby reducing mucus viscosity. In vitro, NAC has antifibrotic effects on lung fibroblasts. As an antidote to acetaminophen poisoning, NAC restores the hepatic GSH pool depleted in the drug detoxification process. More recently, improved knowledge of the mechanisms by which NAC acts has expanded its clinical applications. In particular, the discovery that NAC can modulate the homeostasis of glutamate has prompted studies of NAC in neuropsychiatric diseases characterized by impaired glutamate homeostasis. This narrative review provides an overview of the most relevant and recent evidence on the clinical application of NAC, with a focus on respiratory diseases, acetaminophen poisoning, disorders of the central nervous system (chronic neuropathic pain, depression, schizophrenia, bipolar disorder, and addiction), cardiovascular disease, contrast-induced nephropathy, and ophthalmology (retinitis pigmentosa).

Combined BRM270 and endostatin inhibit relapse of NSCLC while suppressing lung cancer stem cell proliferation induced by endostatin.

Endostatin (ES, ENDO) has been reported to suppress the growth of tumors while inducing the proliferation of lung cancer stem cells (LCSCs), causing a poor prognosis for lung cancer. In this study, we aimed to clarify whether BRM270 can inhibit the proliferation of cancer stem cells (CSCs). Endostatin + BRM270 showed anti-tumor effects by reducing tumor volume and increasing survival. Administration of BRM270 reduced the number of aldehyde dehydrogenase-positive (ALDH+) cells and the level of ALDH1A1 expression in tumors by increasing the level of miR-128 while decreasing the levels of BMI-1, ABCC-5, E2F3, and c-MET. The luciferase activity of miR-128 promoter was increased by an increasing concentration of BRM270. In addition, BMI-1, ABCC-5, E2F3, and c-MET were identified as candidate targets of miR-128, and the overexpression of miR-128 significantly reduced mRNA/protein levels of BMI-1, ABCC-5, E2F3, and c-MET in A549 and H460 cells. Administration of BRM270 inhibited the expression of BMI-1, ABCC-5, E2F3, and c-MET in a dose-dependent manner. In this study, we showed for the first time that the combined administration of endostatin and BRM270 achieved anti-tumor effects while suppressing the proliferation of stem cells.

Mitochondrial-Targeting Antioxidant SS-31 Suppresses Airway Inflammation and Oxidative Stress Induced by Cigarette Smoke.

This study investigated whether the mitochondrial-targeted peptide SS-31 can protect against cigarette smoke- (CS-) induced airway inflammation and oxidative stress in vitro and in vivo. Mice were exposed to CS for 4 weeks to establish a CS-induced airway inflammation model, and those in the experimental group were pretreated with SS-31 1 h before CS exposure. Pathologic changes and oxidative stress in lung tissue, inflammatory cell counts, and proinflammatory cytokine levels in bronchoalveolar lavage fluid (BALF) were examined. The mechanistic basis for the effects of SS-31 on CS extract- (CSE-) induced airway inflammation and oxidative stress was investigated using BEAS-2B bronchial epithelial cells and by RNA sequencing and western blot analysis of lung tissues. SS-31 attenuated CS-induced inflammatory injury of the airway and reduced total cell, neutrophil, and macrophage counts and tumor necrosis factor- (TNF-) α, interleukin- (IL-) 6, and matrix metalloproteinase (MMP) 9 levels in BALF. SS-31 also attenuated CS-induced oxidative stress by decreasing malondialdehyde (MDA) and myeloperoxidase (MPO) activities and increasing that of superoxide dismutase (SOD). It also reversed CS-induced changes in the expression of mitochondrial fission protein (MFF) and optic atrophy (OPA) 1 and reduced the amount of cytochrome c released into the cytosol. Pretreatment with SS-31 normalized TNF-α, IL-6, and MMP9 expression, MDA and SOD activities, and ROS generation in CSE-treated BEAS-2B cells and reversed the changes in MFF and OPA1 expression. RNA sequencing and western blot analysis showed that SS-31 inhibited CS-induced activation of the mitogen-activated protein kinase (MAPK) signaling pathway in vitro and in vivo. Thus, SS-31 alleviates CS-induced airway inflammation and oxidative stress via modulation of mitochondrial function and regulation of MAPK signaling and thus has therapeutic potential for the treatment of airway disorders caused by smoking.

Losartan attenuates chronic cigarette smoke exposure-induced pulmonary arterial hypertension in rats: possible involvement of angiotensin-converting enzyme-2.

Chronic cigarette smoking induces pulmonary arterial hypertension (PAH) by largely unknown mechanisms. Renin-angiotensin system (RAS) is known to function in the development of PAH. Losartan, a specific angiotensin II receptor antagonist, is a well-known antihypertensive drug with a potential role in regulating angiotensin-converting enzyme-2 (ACE2), a recently found regulator of RAS. To determine the effect of losartan on smoke-induced PAH and its possible mechanism, rats were daily exposed to cigarette smoke for 6months in the absence and in the presence of losartan. Elevated right ventricular systolic pressure (RVSP), thickened wall of pulmonary arteries with apparent medial hypertrophy along with increased angiotensin II (Ang II) and decreased ACE2 levels were observed in smoke-exposed-only rats. Losartan administration ameliorated pulmonary vascular remodeling, inhibited the smoke-induced RVSP and Ang II elevation and partially reversed the ACE2 decrease in rat lungs. In cultured primary pulmonary artery smooth muscle cells (PASMCs) from 3- and 6-month smoke-exposed rats, ACE2 levels were significantly lower than in those from the control rats. Moreover, PASMCs from 6-month exposed rats proliferated more rapidly than those from 3-month exposed or control rats, and cells grew even more rapidly in the presence of DX600, an ACE2 inhibitor. Consistent with the in vivo study, in vitro losartan pretreatment also inhibited cigarette smoke extract (CSE)-induced cell proliferation and ACE2 reduction in rat PASMCs. The results suggest that losartan may be therapeutically useful in the chronic smoking-induced pulmonary vascular remodeling and PAH and ACE2 may be involved as part of its mechanism. Our study might provide insight into the development of new therapeutic interventions for PAH smokers.

Role of chymase in cigarette smoke-induced pulmonary artery remodeling and pulmonary hypertension in hamsters.

BACKGROUND: Cigarette smoking is an important risk factor for pulmonary arterial hypertension (PAH) in chronic obstructive pulmonary disease (COPD). Chymase has been shown to function in the enzymatic production of angiotensin II (AngII) and the activation of transforming growth factor (TGF)-beta1 in the cardiovascular system. The aim of this study was to determine the potential role of chymase in cigarette smoke-induced pulmonary artery remodeling and PAH. METHODS: Hamsters were exposed to cigarette smoke; after 4 months, lung morphology and tissue biochemical changes were examined using immunohistochemistry, Western blotting, radioimmunoassay and reverse-transcription polymerase chain reaction. RESULTS: Our results show that chronic cigarette smoke exposure significantly induced elevation of right ventricular systolic pressures (RVSP) and medial hypertrophy of pulmonary arterioles in hamsters, concurrent with an increase of chymase activity and synthesis in the lung. Elevated Ang II levels and enhanced TGF-beta1/Smad signaling activation were also observed in smoke-exposed lungs. Chymase inhibition with chymostatin reduced the cigarette smoke-induced increase in chymase activity and Ang II concentration in the lung, and attenuated the RVSP elevation and the remodeling of pulmonary arterioles. Chymostatin did not affect angiotensin converting enzyme (ACE) activity in hamster lungs. CONCLUSIONS: These results suggest that chronic cigarette smoke exposure can increase chymase activity and expression in hamster lungs. The capability of activated chymase to induce Ang II formation and TGF-beta1 signaling may be part of the mechanism for smoking-induced pulmonary vascular remodeling. Thus, our study implies that blockade of chymase might provide benefits to PAH smokers.