Multifaceted Role for IL-17A in the Pathogenesis of Chronic Obstructive Pulmonary Disease

Effect of physical training on cytokine expression in CD4+ T lymphocytes in subjects with stable COPD

Introduction:

Although evidence suggests that physical exercise reduces systemic inflammation, at the plasma level, there are still contradictions in chronic obstructive pulmonary disease (COPD). In this sense, analysis of intracellular cytokines could clear off the effect of physical exercise on the inflammatory profile of these subjects.

Aim:

The aim was to evaluate the effect of physical training on cytokine expression in CD4+ T lymphocytes from subjects with COPD.

Methods:

This is a randomized controlled trial. Subjects with stable COPD were grouped into two groups, exercise and control. In total, 23 subjects with stable COPD were evaluated, of which 15 underwent aerobic strength training [physical exercise group (PEG)] and 8 underwent breathing exercises [respiratory physiotherapy group (RPG)]. Intracellular cytokines [interleukin (IL)-8, IL-13, IL-17, IL-6, IL-2, IL-10, and tumor necrosis factor alpha (TNF-α)] from CD4+ T lymphocytes were analyzed from peripheral blood through flow cytometry, before and after 8 weeks of intervention.

Results:

The PEG and RPG groups had a mean age of 68 ± 5.96 and 72.25 ± 6.86 years and predicted forced expiratory volume in the first second (FEV₁) of 58.6 ± 15.99% and 39.75 ± 10.39%, respectively. It was possible to detect a significant reduction in IL-8 (p = 0.0125) and an increase in IL-13 (p = 0.0014) and an increase in TNF-α (p < 0.001) in both groups.

Conclusion:

Eight weeks of physical training, both peripheral and respiratory, were able to reduce concentrations of IL-8 and to increase IL-13, and TNF-α in CD4+ T lymphocytes in subjects with stable COPD. The findings reinforce the benefits of interventions in subjects with COPD, revealing data not previously investigated.

Exposure to biomass smoke induces pulmonary Th17 cell differentiation by activating TLR2 on dendritic cells in a COPD rat model

Almost three billion people in developing countries are exposed to biomass smoke (BS), which predisposes them to developing chronic obstructive pulmonary disease (COPD). COPD is associated with abnormal innate and adaptive immune responses in the lungs and systemic circulation, but the mechanisms underlying BS-COPD development are uncertain. We investigated the role of dendritic cells (DCs) and interleukin (IL)-17A in BS-COPD. We investigated T helper cell responses in the BS-exposed COPD rat model by flow cytometry, quantitative PCR, and enzyme-linked immunosorbent assays. We conducted ex vivo experiments to determine which antigen-presenting cells induce Th17 cell responses. We evaluated the in vitro effects of BS-related particulate matter (BRPM) (2.5 μm) on the function of bone marrow-derived dendritic cells (BMDCs). We found that BS exposure enhanced Th17 responses in the lungs of the COPD-modelled rats, and the stimulated DCs (but not the macrophages) were sufficient to induce naïve CD4 + T cells to produce IL-17A in ex vivo experiments. BRPM significantly enhanced the maturation and activation of DCs through Toll-like receptor 2 (TLR2), but not TLR4, and induced Th17 responses. Therefore, BS activated lung DCs through TLR2, which led to Th17 responses and emphysema in the rats. This process is possibly therapeutically targetable.

Microbiota Imbalance Contributes to COPD Deterioration by Enhancing IL-17a Production via miR-122 and miR-30a

The changes of microbiota in lungs could change interleukin-17a (IL-17a) expression by altering microRNAs (miRNAs) profile, thus contributing to the pathogenesis of chronic obstructive pulmonary disease (COPD). In this study, we aimed to study molecular mechanisms’ underlying effect of microbiota imbalance on COPD deterioration. Real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) were performed to analyze expression of miRNAs and IL-17a mRNA. ELISA was used to evaluate abundance of IL-17a in plasma, peripheral blood monocyte, and sputum of COPD mice and patients. Luciferase assay was performed to explore underlying molecular mechanisms. The expression of miR-122, miR-30a, and miR-99b were remarkably decreased in COPD mice, while the expression of IL-17a was notably increased in plasma, peripheral blood monocytes, and lung tissues of COPD mice. The levels of Lactobacillus/Moraxella and IL-17a expression were significantly enhanced in sputum of exacerbated COPD patients, along with notably decreased expression of miR-122 and miR-30a. Luciferase assay confirmed that miR-122 and miR-30a played an inhibitory role in IL-17a expression. We identified miR-122 and miR-30a as differentially expressed miRNAs in sputum and plasma of COPD patients in exacerbation-month12 group. Furthermore, downregulated miR-122 and miR-30a expression associated with microbiota imbalance may contribute to COPD deterioration by enhancing IL-17a production.

Losartan does not inhibit cigarette smoke-induced lung inflammation in mice

Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease largely caused by cigarette smoking (CS) and is characterized by lung inflammation and airflow limitation that is not fully reversible. Approximately 50% of people with COPD die of a cardiovascular comorbidity and current pharmacological strategies provide little benefit. Therefore, drugs that target the lung and the cardiovascular system concurrently may be an advantageous therapeutic strategy. The aim of this study was to see whether losartan, an angiotensin-II AT1a receptor antagonist widely used to treat hypertension associated with cardiovascular disease, protects against CS-induced lung inflammation in mice. Male BALB/c mice were exposed to CS for 8 weeks and treated with either losartan (30 mg/kg) or vehicle daily. Mice were euthanized and bronchoalveolar lavage fluid (BALF) inflammation, and whole lung cytokine, chemokine and protease mRNA expression assessed. CS caused significant increases in BALF total cells, macrophages, neutrophils and whole lung IL-6, TNF-α, CXCL-1, IL-17A and MMP12 mRNA expression compared to sham-exposed mice. However, losartan only reduced CS-induced increases in IL-6 mRNA expression. Angiotensin-II receptor expression was reduced in lung tissue from CS-exposed mice. In conclusion, losartan did not inhibit CS-induced BALF cellularity despite reducing whole lung IL-6 mRNA and Ang-II receptor expression.

Genetic polymorphisms of IL17A, TLR4 and P2RX7 and associations with the risk of chronic obstructive pulmonary disease

We investigated the association between genetic polymorphisms of IL17A, TLR4 and P2RX7 genes and chronic obstructive pulmonary disease (COPD) in a Han population. We performed a case-control study with 152 COPD subjects from the Third People's Hospital of Nantong in 2015. Healthy controls were selected from a group of people attending the physical examination and were frequency-matched to the cases by sex and age. Genotyping was performed using TaqMan allelic discrimination technology. A logistic regression model was used to calculated odds ratios (OR) and 95% confidence intervals (CI). After Bonferroni correction, polymorphisms rs2275913 and rs763780 in the IL17A gene, rs10759932 and rs2737190 in the TLR4 gene, and rs1718119 in the P2RX7 gene were significantly associated with altered risk for COPD. Individuals carrying rs2275913 allele A had a reduced risk (OR 0.62; 95% CI: 0.46-0.86). Individuals carrying rs763780 allele C had an increased risk (OR 1.96; 95% CI: 1.29-2.98). Individuals carrying rs10759932 allele C had a reduced risk (OR 0.49; 95% CI: 0.34-0.73). Individuals carrying rs2737190 allele G had a reduced risk (OR 0.51; 95% CI: 0.37-0.71). Individuals carrying rs1718119 allele A had a reduced risk (OR 0.69; 95% CI: 0.45-1.06).Genetic polymorphisms in IL17A, TLR4 and P2RX7 genes were significantly associated with altered risks for COPD.

Scabies increased the risk and severity of COPD: a nationwide population-based study

Background

Scabies is a common parasitic infectious disease, and COPD is a major pulmonary disease. However, there have been no previous studies that have investigated the relationship between scabies and COPD.

Materials and methods

This nationwide population-based study included a total of 3,568 patients with scabies as the study group and 14,255 patients as a control group. We followed up patients in both groups for a 5-year period to identify any new diagnoses of COPD. We then followed them up for an additional 2-year period to determine the severity of any newly diagnosed cases of COPD as indicated by acute respiratory events. Cox proportional hazard regression analyses were performed to calculate the hazard ratio (HR) of COPD during the 5-year follow-up period and COPD complication during the additional 2-year follow-up period.

Results

Of the 17,823 patients in the study, 2,765 (15.5%) were newly diagnosed with COPD during the 5-year follow-up period; 904 (32.7%) were from the scabies group; and 1,861 (67.3%) were from the control group. Compared to the patients without scabies, the adjusted HR (aHR) for COPD for the subjects with scabies was 1.72 (95% CI: 1.59–1.87) during the 5-year follow-up period. For those newly diagnosed with COPD, the aHR for COPD with acute exacerbation was 1.85 (95% CI: 1.67–2.06), the aHR for COPD with pneumonia was 3.29 (95% CI: 2.77–3.92), the aHR for COPD with acute respiratory failure was 4.00 (95% CI: 3.08–5.19), and the aHR for COPD with cardiopulmonary arrest was 3.95 (95% CI: 2.25–6.95) during the additional 2-year follow-up period.

Conclusion

The results of this study indicate a 72% increased risk for COPD among patients with scabies. The results also reveal an increased risk of severe COPD complications such as acute respiratory failure, cardiopulmonary arrest, pneumonia, and acute exacerbation among patients with scabies. This useful information may help physicians in treating scabies and remaining alert to the potential development of COPD and its severe complications.