Lung Inflammation In Chronic Obstructive Pulmonary Disease Research Articles

Interleukin-2/anti-interleukin-2 complex attenuates inflammation in a mouse COPD model by expanding CD4+ CD25+ Foxp3+ regulatory T cells

Background and purposeChronic, nonspecific inflammation of the alveoli and airways is an important pathological feature of chronic obstructive pulmonary disease (COPD), while sustained inflammatory reactions can cause alveolar damage. Regulatory T cells (Tregs) inhibit inflammation, whereas the interleukin-2/anti-interleukin-2 complex (IL-2C) increases the number of Tregs; however, whether the IL-2C has a therapeutic role in COPD remains unknown. Therefore, this study investigated whether IL-2C alleviates lung inflammation in COPD by increasing the number of Tregs. Experimental approachA mouse COPD model was created by exposing mice to lipopolysaccharides (LPS) and cigarette smoke (CS), and the effects of IL-2C treatment on COPD were evaluated. The number of Tregs in the spleen and lung, pulmonary pathological changes, and inflammatory damage were examined through flow cytometry, histopathology, and immunofluorescence, respectively. Key resultsIL-2C increased the number of Treg cells in the spleen and lungs after exposure to CS and LPS, reduced the number of T helper 17 (Th17) cells in lung tissue, and improved the Th17/Treg balance. IL-2C decreased the number of inflammatory cells and reduced the levels of pro-inflammatory cytokines IL-6, TNF-α, IL-1β, CCL5, KC, and MCP-1 in bronchoalveolar lavage fluid and serum. IL-2C significantly reduced the pathological scores for lung inflammation, as well as decreased airway mucus secretion and infiltration of neutrophils and macrophages in the lungs. The depletion of Tregs using anti-CD25 antibodies eliminated the beneficial effects of IL-2C. Conclusions and implicationsIL-2C is a potential therapeutic agent for alleviating excessive inflammation in the lungs of patients with COPD.

Bulb of Lilium longiflorum Thunb Extract Fermented with Lactobacillus acidophilus Reduces Inflammation in a Chronic Obstructive Pulmonary Disease Model.

Chronic obstructive pulmonary disease (COPD), one of the leading causes of death worldwide, is caused by repeated exposure to harmful matter, such as cigarette smoke. Although Lilium longiflorum Thunb (LLT) has anti-inflammatory effects, there is no report on the fermented LLT bulb extract regulating lung inflammation in COPD. Thus, we investigated the protective effect of LLT bulb extract fermented with Lactobacillus acidophilus 803 in COPD mouse models induced by cigarette smoke extract (CSE) and porcine pancreas elastase (PPE). Oral administration of the fermented product (LS803) suppressed the production of inflammatory mediators and the infiltration of immune cells involving neutrophils and macrophages, resulting in protective effects against lung damage. In addition, LS803 inhibited CSE- and LPS-induced IL-6 and IL-8 production in airway epithelial H292 cells as well as suppressed PMA-induced formation of neutrophil extracellular traps in HL-60 cells. In particular, LS803 significantly repressed the elevated IL-6 and MIP-2 production after CSE and LPS stimulation by suppressing the activity of the nuclear factor kappa-light-chain-enhancer of activated B (NFκB) in mouse peritoneal macrophages. Therefore, our results suggest that the fermented product LS803 is effective in preventing and alleviating lung inflammation.

Effects of photobiomodulation as an adjunctive treatment in chronic obstructive pulmonary disease: a narrative review.

Chronic obstructive pulmonary disease (COPD) is a disease characterized by chronic airway inflammation and remodeling and lung parenchymal inflammation and destruction, which result in many pulmonary and extrapulmonary manifestations. The anti-inflammatory effect of photobiomodulation (PBM) has been reported in previous studies. This review was conducted to evaluate the direct effect of PBM on lung inflammation in COPD. The other effects of PBM on modulation of peripheral and respiratory muscle metabolism and angiogenesis in lung tissues were also discussed. The databases of PubMed, Cochrane Library, and Google Scholar were searched to find the relevant studies. Keywords included PBM and related terms, COPD-related signs, and lung inflammation. A total of 12 articles were selected and reviewed in this study. Based on the present review, PBM is helpful in reducing lung inflammation through decreasing the inflammatory cytokines and chemokines at multiple levels and increasing anti-inflammatory cytokines. In addition, PBM also improves both peripheral and respiratory muscle metabolism and promote angiogenesis. This review demonstrated that PBM is a promising adjunctive treatment modality for COPD management which merits further validation.

Effects of Maxingloushi decoction on immune inflammation and programmed death markers in mice with chronic obstructive pulmonary disease.

To investigate effects of Maxingloushi decoction on lung inflammation and programmed death markers (programmed death-1 [PD-1], programmed death-ligand 1 [PD-L1]) in the lung tissue, peripheral blood, and bronchoalveolar lavage fluid (BLF) in a mouse model of chronic obstructive pulmonary disease (COPD). Thirty-six mature male BALB/C mice were randomly divided into normal group (group A, n=6), COPD model group (group B, n=10), Maxingloushi decoction + COPD group (group C, n=10), and PD-1 inhibitor + COPD group (group D, n=10). The COPD model was established by smoke inhalation combined with lipopolysaccharide (LPS). Levels of PD-1 and PD-L1 in plasma and BLF were measured by enzyme-linked immunosorbent assay (ELISA). Histopathological techniques were used to semi-quantitatively analyze the immuno-fluorescence optical density (IOD) value of the lung tissue. In plasma and BLF, the expression of PD-1 in the group B was higher than that in the group A, and the expression of PD-L1 was lower than that in the group A. The expression of PD-1 and PD-L1 in the lung tissue was normalized in the group C in comparison with the group B (P<0.05) and the group D (P<0.05), and inflammatory cell infiltration in the lung tissue was also improved. These findings reveal that COPD causes an immune imbalance in the peripheral blood and lung tissue, and that both Maxingloushi decoction and PD-1 inhibitor treatment can mitigate lung inflammation in COPD by reducing PD-1 expression and increasing PD-L1 expression. The treatment effect of Maxingloushi decoction may be superior to that of PD-1 inhibitor.

Contribution of dipeptidyl peptidase 4 to non-typeable Haemophilus influenzae-induced lung inflammation in COPD.

Dipeptidyl peptidase 4 (DPP4) expression is increased in the lungs of chronic obstructive pulmonary disease (COPD). DPP4 is known to be associated with inflammation in various organs, including LPS-induced acute lung inflammation. Since non-typeable Haemophilus influenzae (NTHi) causes acute exacerbations in COPD patients, we examined the contribution of DPP4 in NTHi-induced lung inflammation in COPD. Pulmonary macrophages isolated from COPD patients showed higher expression of DPP4 than the macrophages isolated from normal subjects. In response to NTHi infection, COPD, but not normal macrophages show a further increase in the expression of DPP4. COPD macrophages also showed higher expression of IL-1β, and CCL3 responses to NTHi than normal, and treatment with DPP4 inhibitor, diprotin A attenuated this response. To examine the contribution of DPP4 in NTHi-induced lung inflammation, COPD mice were infected with NTHi, treated with diprotin A or PBS intraperitoneally, and examined for DPP4 expression, lung inflammation, and cytokine expression. Mice with COPD phenotype showed increased expression of DPP4, which increased further following NTHi infection. DPP4 expression was primarily observed in the infiltrated inflammatory cells. NTHi-infected COPD mice also showed sustained neutrophilic lung inflammation and expression of CCL3, and this was inhibited by DPP4 inhibitor. These observations indicate that enhanced expression of DPP4 in pulmonary macrophages may contribute to sustained lung inflammation in COPD following NTHi infection. Therefore, inhibition of DPP4 may reduce the severity of NTHi-induced lung inflammation in COPD.

Cigarette smoke-induced lung inflammation in COPD mediated via CCR1/JAK/STAT /NF-κB pathway.

Inflammation is an important cause of chronic obstructive pulmonary disease (COPD) and its acute exacerbation. However, the critical role of C-C chemokine receptor (CCR)1 in progression of cigarette smoke-induced chronic inflammation remains unclear. We studied CCR1 expression using immunohistochemistry, immunofluorescence, and real-time polymerase chain reaction (RT-PCR) in COPD patients and controls. Cytokine levels in peripheral blood were measured by enzyme-linked immunosorbent assay (ELISA). In vitro, we investigated Janus kinase/signal transducers and activators of transcription (JAK/STAT)/nuclear factor-κB (NF-κB) signaling in cigarette smoke extract-induced or CCR1 deficiency/overexpressed mouse macrophage cell line MH-S by RT-PCR and western blot, and measured the cytokine levels in the supernatant with ELISA. We found that CCR1 expression was upregulated in COPD patients and there was a negative correlation between CCR1 mRNA levels and predicted % forced expiratory volume in 1 min. Inflammatory cytokine levels in the peripheral blood were higher in COPD patients than controls, and these were positively correlated with CCR1 levels. CCR1 was shown to play a critical role in regulating smoke-induced inflammation via JAK/STAT3/NF-κB signaling in vitro. CCR1 may play a critical role in airway inflammation in COPD. Additionally, understanding the molecular mechanism may help develop novel methods for the treatment of COPD.

Sphingolipids in COPD.

Sphingolipids are a distinct class of lipid molecules widely found in nature, principally as cell membrane constituents. After initial uncertainty about their function, sphingolipids have been increasingly recognised to be metabolically active entities involved in many biological processes, including the control of inflammation. Their role as mediators of inflammation may have significant implications for a range of lung diseases in which inflammation is a central element of pathogenesis. Chronic obstructive pulmonary disease (COPD), a highly prevalent and morbid condition predominantly affecting cigarette smokers, is a prime example of a respiratory illness with an inflammatory component. Understandably, sphingolipids have received growing attention for their increasingly demonstrated role in the pathophysiology of COPD. The present review aims to be among the first to focus exclusively on the connection between sphingolipids and lung inflammation in COPD, providing the reader with a clinically oriented synopsis of this intriguing association.

Picroside II Isolated from Pseudolysimachion rotundum var. subintegrum Inhibits Glucocorticoid Refractory Serum Amyloid A (SAA) Expression and SAA-induced IL-33 Secretion.

Chronic obstructive pulmonary disease (COPD) is a major inflammatory lung disease characterized by irreversible and progressive airflow obstruction. Although corticosteroids are often used to reduce inflammation, steroid therapies are insufficient in patients with refractory COPD. Both serum amyloid A (SAA) and IL-33 have been implicated in the pathology of steroid-resistant lung inflammation. Picroside II isolated from Pseudolysimachion rotundum var. subintegrum (Plantaginaceae) is a major bioactive component of YPL-001, which has completed phase-2a clinical trials in chronic obstructive pulmonary disease patients. In this study, we investigated whether picroside II is effective in treating steroid refractory lung inflammation via the inhibition of the SAA-IL-33 axis. Picroside II inhibited LPS-induced SAA1 expression in human monocytes, which are resistant to steroids. SAA induced the secretion of IL-33 without involving cell necrosis. Picroside II, but not dexamethasone effectively inhibited SAA-induced IL-33 expression and secretion. The inhibitory effect by picroside II was mediated by suppressing the mitogen-activated protein kinase (MAPK) p38, ERK1/2, and nuclear factor-κB pathways. Our results suggest that picroside II negatively modulates the SAA-IL-33 axis that has been implicated in steroid-resistant lung inflammation. These findings provide valuable information for the development of picroside II as an alternative therapeutic agent against steroid refractory lung inflammation in COPD.

Abstract A32: Mechanistic Dissection of Lung Cancer Promotion by Airway Inflammation

Abstract Cigarette smoking is the principal cause of lung carcinogenesis, however, smokers with chronic obstructive pulmonary disease (COPD) have an increased risk of lung cancer (3 to 10 fold) compared to smokers with comparable cigarette exposure but without COPD. Histopathologic studies have clearly demonstrated lung inflammation in COPD, and it persists even after cessation of cigarette smoking. These facts suggest a strong link between COPD-related airway inflammation and lung cancer promotion independent of smoking but the precise mechanistic link is not known. We developed a COPD-like mouse model of airway inflammation through repeated aerosol challenge to a lysate of non-typeable Haemophilus influenzae (NTHi) which commonly colonizes the airways of COPD patients. Then, we showed that this type of airway inflammation, but not asthma-like airway inflammation, promotes lung cancer in a K-ras mutant mouse model of lung cancer (CC-LR). This was associated with NF-kB pathway activation, and up-regulation of its downstream target genes, including IL-6 and T helper 17 (Th17) response. Therefore, we studied the role of NF-kB in lung cancer promotion by targeting its expression in airway epithelium. CC-LR mice were crossed with IKK-βf/f mice to develop a mouse with lack of NF-kB activity in airway secretory cells (CC-LR-IKKβ mice). NF-kB deficiency in the airway epithelium changed the bronchoalveolar lavage fluid (BALF) cellular component (mostly reduction in macrophage number) of the CC-LR mice, and resulted in a ∼70% (3.4-fold) reduction in lung surface tumor number compared to age and sex matched control CC-LR mice. It also significantly reduced the number of visible tumors on the lung surface of the CC-LR mice by &amp;gt;60% (2.6-fold) after inducing COPD-like airway inflammation using weekly NTHi exposure for 8 weeks. We then genetically ablated IL-6 in the CC-LR mice. Lack of IL-6 did not change the BALF inflammatory cell component of the CC-LR mice. However, it not only inhibited intrinsic lung cancer development (1.7-fold, 41%), but also inhibited the promoting effect of extrinsic NTHi-induced COPD-like airway inflammation (2.6-fold, 62%) on lung carcinogenesis, suggesting a role for IL-6 mediated epithelial cell signaling in tumor promotion by COPDlike airway inflammation. This is under further investigation by our group. IL-6 is required for differentiation of Th17 cells from naive T cells. Th17 cells mostly produce IL-17A, and IL-17F. These both bind to the IL-17 receptor (IL-17R), and IL-17R signaling is required for lung CXC chemokine expression and neutrophil recruitment, however, we found that only the IL-17R KO and IL-17A KO but not IL-17F KO mice showed lower levels of neutrophilic influx into the BALF and less inflammatory cell infiltration in lung tissue in response to NTHi. Furthermore, IL-17A induces more production of IL-6 by epithelial cells. So, CC-LR mice were crossed with IL-17A KO mice. Lack of IL-17A resulted in a ∼70% (3.4-fold) reduction in lung surface tumor number compared to age and sex matched control CC-LR mice. It also significantly reduced the number of visible tumors on the lung surface of the CCLR mice by ∼54% (2.2-fold) after inducing COPD-like airway inflammation using weekly NTHi exposure for 4 weeks from the age of 10 weeks. We conclude that airway inflammation through NF-kB mediated activation of the IL-6/Th17 signaling pathway promotes lung carcinogenesis.

Effects of inhaled corticosteroids on airway inflammation in chronic obstructive pulmonary disease: a systematic review and meta-analysis

Background:Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation in the small airways. The effect of inhaled corticosteroids (ICS) on lung inflammation in COPD remains uncertain. We sought to determine the effects of ICS on inflammatory indices in bronchial biopsies and bronchoalveolar lavage fluid of patients with COPD.Methods:We searched Medline, Embase, Cinahl, and the Cochrane database for randomized, controlled clinical trials that used bronchial biopsies and bronchoalveolar lavage to evaluate the effects of ICS in stable COPD. For each chosen study, we calculated the mean differences in the concentrations of inflammatory cells before and after treatment in both intervention and control groups. These values were then converted into standardized mean differences (SMD) to accommodate the differences in patient selection, clinical treatment, and biochemical procedures that were employed across the original studies. If significant heterogeneity was present (P < 0.1), then a random effects model was used to pool the original data; otherwise, a fixed effects model was used.Results:We identified eight original studies that met the inclusion criteria. Four studies used bronchial biopsies (n =102 participants) and showed that ICS were effective in reducing CD4 and CD8 cell counts (SMD, −0.52 units and −0.66 units, 95% confidence interval). The five studies used bronchoalveolar lavage fluid (n =309), which together showed that ICS reduced neutrophil and lymphocyte counts (SMD, −0.64 units and −0.64 units, 95% confidence interval). ICS on the other hand significantly increased macrophage counts (SMD, 0.68 units, 95% confidence interval) in bronchoalveolar lavage fluid.Conclusion:ICS has important immunomodulatory effects in airways with COPD that may explain its beneficial effect on exacerbations and enhanced risk of pneumonia.

Telomere Dysfunction Causes Sustained Inflammation in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is associated with chronic inflammation of unknown pathogenesis. To investigate whether telomere dysfunction and senescence of pulmonary vascular endothelial cells (P-ECs) induce inflammation in COPD. Prospective comparison of patients with COPD and age- and sex-matched control smokers. Investigation of mice null for telomerase reverse transcriptase (Tert) or telomerase RNA component (Terc) genes. In situ lung specimen studies showed a higher percentage of senescent P-ECs stained for p16 and p21 in patients with COPD than in control subjects. Cultured P-ECs from patients with COPD exhibited early replicative senescence, with decreased cell-population doublings, a higher percentage of β-galactosidase-positive cells, reduced telomerase activity, shorter telomeres, and higher p16 and p21 mRNA levels at an early cell passage compared with control subjects. Senescent P-ECs released cytokines and mediators: the levels of IL-6, IL-8, monocyte chemotactic protein (MCP)-1, Hu-GRO, and soluble intercellular adhesion molecule (sICAM)-1 were elevated in the media of P-ECs from patients compared with control subjects at an early cell passage, in proportion to the senescent P-EC increase and telomere shortening. Up-regulation of MCP-1 and sICAM-1 led to increased monocyte adherence and migration. The elevated MCP-1, IL-8, Hu-GROα, and ICAM-1 levels measured in lungs from patients compared with control subjects correlated with P-EC senescence criteria and telomere length. In Tert(-/-) and/or Terc(-/-) mouse lungs, levels of the corresponding cytokines (MCP-1, IL-8, Hu-GROα, and ICAM-1) were also altered, despite the absence of external stimuli and in proportion to telomere dysfunction. Telomere dysfunction and premature P-EC senescence are major processes perpetuating lung inflammation in COPD.

Current Perspectives on Role of Chromatin Modifications and Deacetylases in Lung Inflammation in COPD

Chromatin modifications and epigenetic regulation are critical for sustained and abnormal inflammatory response seen in lungs of patients with chronic obstructive pulmonary disease (COPD) because the activities of enzymes that regulate these epigenetic modifications are altered in response to cigarette smoke. Cigarette smoke induces chromatin modifications and epigenetic changes by causing post-translational modifications of histone acetyltransferases, and histone/non-histone deacetylases (HDACs), such as HDAC2 and sirtuin 1 (SIRT1), which leads to chromatin remodeling. In this review, we discussed the current knowledge on cigarette smoke/oxidants-induced post-translational modifications of deacetylases (HDAC2 and SIRT1), disruption of HDAC2/SIRT1-RelA/p65 corepressor complex associated with acetylation of RelA/p65, and chromatin modifications (histone H3 phospho-acetylation) leading to sustained pro-inflammatory gene transcription. Knowledge on molecular mechanisms of epigenetic changes in abnormal lung inflammation will help in understanding the pathophysiology of COPD which may lead to the development of novel epigenetic therapies in the near future.