The Th17/Treg Cytokine Imbalance in Chronic Obstructive Pulmonary Disease Exacerbation in an Animal Model of Cigarette Smoke Exposure and Lipopolysaccharide Challenge Association

A High MCT-Based Ketogenic Diet Suppresses Th1 and Th17 Responses to Ameliorate Experimental Autoimmune Encephalomyelitis in Mice by Inhibiting GSDMD and JAK2-STAT3/4 Pathways

SCOPE

Inflammation and pyroptosis play important roles in the pathogenesis of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). In this study, we evaluated the therapeutic potential of ketogenic diet (KD) in EAE.

METHODS AND RESULTS

The administration of KD reduces demyelination and microglial activation in the spinal cord of EAE mice. Meanwhile, KD decreases the levels of Th1 and Th17 associated cytokines/transcription factors production (T-bet, IFN-γ, RORγt, and IL-17) and increases those of Th2 and Treg cytokines/transcription factors (GATA3, IL-4, Foxp3, and IL-10) in the spinal cord and spleen. Corresponding, KD reduces the expression of chemokines in EAE, which those chemokines associate with T-cell infiltration into central nervous system (CNS). In addition, KD inhibits the GSDMD activation in microglia, oligodendrocyte, CD31+ cells, CCR2+ cells, and T cells in the spinal cord. Moreover, KD significantly decreases the ratios of p-JAK2/JAK2, p-STAT3/STAT3, and p-STAT4/STAT4, as well as GSDMD in EAE mice.

CONCLUSIONS

this study demonstrates that KD reduces the activation and differentiation of T cells in the spinal cord and spleen and prevents T cell infiltration into CNS of EAE via modulating the GSDMD and STAT3/4 pathways, suggesting that KD is a potentially effective strategy in the treatment of MS.

Microbes little helpers and suppliers for therapeutic asthma approaches

Bronchial asthma is a prevalent and increasingly chronic inflammatory lung disease affecting over 300 million people globally. Initially considered an allergic disorder driven by mast cells and eosinophils, asthma is now recognized as a complex syndrome with various clinical phenotypes and immunological endotypes. These encompass type 2 inflammatory endotypes characterized by interleukin (IL)-4, IL-5, and IL-13 dominance, alongside others featuring mixed or non-eosinophilic inflammation. Therapeutic success varies significantly based on asthma phenotypes, with inhaled corticosteroids and beta-2 agonists effective for milder forms, but limited in severe cases. Novel antibody-based therapies have shown promise, primarily for severe allergic and type 2-high asthma. To address this gap, novel treatment strategies are essential for better control of asthma pathology, prevention, and exacerbation reduction. One promising approach involves stimulating endogenous anti-inflammatory responses through regulatory T cells (Tregs). Tregs play a vital role in maintaining immune homeostasis, preventing autoimmunity, and mitigating excessive inflammation after pathogenic encounters. Tregs have demonstrated their ability to control both type 2-high and type 2-low inflammation in murine models and dampen human cell-dependent allergic airway inflammation. Furthermore, microbes, typically associated with disease development, have shown immune-dampening properties that could be harnessed for therapeutic benefits. Both commensal microbiota and pathogenic microbes have demonstrated potential in bacterial-host interactions for therapeutic purposes. This review explores microbe-associated approaches as potential treatments for inflammatory diseases, shedding light on current and future therapeutics.

Astragaloside IV restores Th17/Treg balance via inhibiting CXCR4 to improve chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) has a high fatality rate and poses a great threat to human health. Astragaloside IV (AS-IV) is proven to attenuate cigarette smoke (CS)-induced pulmonary inflammation, based on which this research focuses on the mechanism of AS-IV in COPD.

METHODS

To evaluate the effects of AS-IV, CD4+ T cells received different concentrations of AS-IV. CD4+ T cell viability, T helper 17 (Th17)/regulatory T (Treg) markers and CXCR4 expressions in CD4+ T cells or spleen/lung tissues were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay, quantitative real-time polymerase chain reaction and Western blot. The proportions of Treg and Th17 cells were assessed by flow cytometry. Enzyme-linked immune sorbent assay was employed to determine cytokine contents in serum and lung tissues.

RESULTS

AS-IV with concentration exceeding 40 µM inhibited CD4+ T cell viability. In vitro, AS-IV suppressed the expressions of CXCR4, retinoid-related orphan receptor γt (RORγt), and interleukin (IL)-17A as well as Th17 cells but promoted the expressions of forkhead box p3 (Foxp3) and IL-10 as well as Treg cells, while CXCR4 overexpression reversed the effects of AS-IV. In vivo, AS-IV alleviated COPD, and CS-induced Th17/Treg imbalance in mice and reduced CS-induced down-regulation of IL-10 in serum and lung tissues and Foxp3 and up-regulation of IL-1β, tumor necrosis factor alpha (TNF-α), IL-6, and IL-17A in serum and lung tissues and RORγt. AS-IV mitigated CS-induced CXCR4 up-regulation. Above effects of AS-IV on mice were offset by CXCR4 overexpression.

CONCLUSIONS

AS-IV restores Th17/Treg balance via impeding CXCR4 to ameliorate COPD.

Mogroside V ameliorates broiler pulmonary inflammation via modulating lung microbiota and rectifying Th17/Treg dysregulation in lipopolysaccharides-induced lung injury

The dysbiosis of lung microbiota and inflammatory factors play a crucial role in the occurrence of lipopolysaccharides (LPS)-induced lung injury. Recently, mogroside V (MGV) has received increasing attention due to its potential health benefits in pneumonia, but its complex mechanism needs further experimental elucidation. In this study, we established an LPS-induced chicken lung injury model to investigate the protective effect of MGV on LPS-induced acute lung injury in broiler and its related mechanisms. A total of 192 one-day-old white-finned broilers were randomly assigned into 4 groups with 6 replicates: 1) control group: basal diet (d 1-44), saline (d 43); 2) LPS group: basal diet (d 1-44), LPS (d 43); 3) MGV group: basal diet + 0.2% MGV (d 1-44), saline (d 43); 4) MGV-LPS group: basal diet + 0.2% MGV (d 1-44), LPS (d 43). The results showed that pathological examination showed that lung tissue inflammation infiltration was reduced after MGV treatment. In addition, MGV can promote the balance of Th17 and Treg cell cytokines, significantly inhibit the expression of proinflammatory cytokines (IL-1β (P < 0.01), IL-6 (P < 0.001), IL-17F (P < 0.05)), and decrease immunosuppressive target expression (PD-L1 (P < 0.01), PD-1 (P < 0.001), RORα (P < 0.001)), activating the immune system. Furthermore, 16S rRNA sequencing analysis showed that MGV treatment could increase the abundance of beneficial bacteria in the lung and reduce the abundance of bacteria associated with inflammation. Generally, MGV intervention has a preventive effect on the pathological damage induced by lipopolysaccharides. Its mechanism is related to inhibiting the inflammatory response, regulating the Th17/Treg balance, and maintaining the stability of lung microbiota.

CXCR4 enhances the inhibitory effects of bone mesenchymal stem cells on lung cell apoptosis in a rat model of smoking-induced COPD

Chronic obstructive pulmonary disease is the 3rd leading cause of death worldwide, and the available treatments are unsatisfactory, resulting in a major economic burden. As cellular therapy is commonly used for lung disease, we investigated a treatment with CXCR4-overexpressing BMSCs in a COPD model. We extracted and purified Bone marrow mesenchymal stem cells (BMSCs) from SD rats. COPD apoptosis model was established by cigarette smoke exposure. BMSCs (1 × 106 cells per injection)were transplanted in vivo twice a month during model establishment, and alveolar rupture in the lung was assessed. Lung cell apoptosis was assessed by terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) analysis, and the concentrations of apoptotic proteins in the lungs were detected by Western blotting. We successfully isolated BMSCs and established CXCR4-overexpressing BMSCs. qRT‒PCR and Western blotting detection both reveal that CXCR4 mRNA level and protein both significantly higher expression in CXCR4-BMSCs than the pBABE-BMSCs. Continuous cigarette smoke exposure caused alveolar septal rupture: In the model group, the alveolar mean linear intercept in the first month was significantly lower than that in the third month (p < 0.05). In the third month, the alveolar mean linear intercept values of the control and CXCR4-BMSC groups were lower than those of the model group (control group p < 0.01, CXCR4-BMSC group p < 0.05), and TUNEL staining revealed that the apoptosis rates of the control and CXCR4-BMSC groups were significantly lower than those of the model group (p < 0.01). Furthermore, the levels of the apoptotic proteins cleaved caspase-8, cleaved caspase-3 and cleaved PARP-1 were higher in the model group than in the control group (p < 0.05) and significantly lower in the CXCR4-BMSC group than in the model group (p < 0.05). The transplantation of CXCR4-overexpressing BMSCs during COPD model generation significantly inhibited apoptosis via the extrinsic apoptosis pathway. CXCR4 enhances the inhibitory effects of bone mesenchymal stem cells on lung cell apoptosis in a rat model of smoking-induced COPD.

Increased exploration and hyperlocomotion in a cigarette smoke and LPS-induced murine model of COPD: linking pulmonary and systemic inflammation with the brain

Brain-related comorbidities are frequently observed in chronic obstructive pulmonary disease (COPD) and are related to increased disease progression and mortality. To date, it is unclear which mechanisms are involved in the development of brain-related problems in COPD. In this study, a cigarette smoke and lipopolysaccharide (LPS) exposure murine model was used to induce COPD-like features and assess the impact on brain and behavior. Mice were daily exposed to cigarette smoke for 72 days, except for days 42, 52, and 62, on which mice were intratracheally exposed to the bacterial trigger LPS. Emphysema and pulmonary inflammation as well as behavior and brain pathology were assessed. Cigarette smoke-exposed mice showed increased alveolar enlargement and numbers of macrophages and neutrophils in bronchoalveolar lavage. Cigarette smoke exposure resulted in lower body weight, which was accompanied by lower serum leptin levels, more time spent in the inner zone of the open field, and decreased claudin-5 and occludin protein expression levels in brain microvessels. Combined cigarette smoke and LPS exposure resulted in increased locomotion and elevated microglial activation in the hippocampus of the brain. These novel findings show that systemic inflammation observed after combined cigarette smoke and LPS exposure in this COPD model is associated with increased exploratory behavior. Findings suggest that neuroinflammation is present in the brain area involved in cognitive functioning and that blood-brain barrier integrity is compromised. These findings can contribute to our knowledge about possible processes involved in brain-related comorbidities in COPD, which is valuable for optimizing and developing therapy strategies.

Microbiome as an immune regulator in health, disease, and therapeutics

New discoveries in drugs and drug delivery systems are focused on identifying and delivering a pharmacologically effective agent, potentially targeting a specific molecular component. However, current drug discovery and therapeutic delivery approaches do not necessarily exploit the complex regulatory network of an indispensable microbiota that has been engineered through evolutionary processes in humans or has been altered by environmental exposure or diseases. The human microbiome, in all its complexity, plays an integral role in the maintenance of host functions such as metabolism and immunity. However, dysregulation in this intricate ecosystem has been linked with a variety of diseases, ranging from inflammatory bowel disease to cancer. Therapeutics and bacteria have an undeniable effect on each other and understanding the interplay between microbes and drugs could lead to new therapies, or to changes in how existing drugs are delivered. In addition, targeting the human microbiome using engineered therapeutics has the potential to address global health challenges. Here, we present the challenges and cutting-edge developments in microbiome-immune cell interactions and outline novel targeting strategies to advance drug discovery and therapeutics, which are defining a new era of personalized and precision medicine.

Implications of regulatory T cells in non-lymphoid tissue physiology and pathophysiology

Treg cells have been initially described as gatekeepers for the control of autoimmunity, as they can actively suppress the activity of other immune cells. However, their role goes beyond this as Treg cells further control immune responses during infections and tumor development. Furthermore, Treg cells can acquire additional properties for e.g., the control of tissue homeostasis. This is instructed by a specific differentiation program and the acquisition of effector properties unique to Treg cells in non-lymphoid tissues. These tissue Treg cells can further adapt to their tissue environment and acquire distinct functional properties through specific transcription factors activated by a combination of tissue derived factors, including tissue-specific antigens and cytokines. In this review, we will focus on recent findings extending our current understanding of the role and differentiation of these tissue Treg cells. As such we will highlight the importance of tissue Treg cells for tissue maintenance, regeneration, and repair in adipose tissue, muscle, CNS, liver, kidney, reproductive organs, and the lung.

MBL Binding with AhR Controls Th17 Immunity in Silicosis-Associated Lung Inflammation and Fibrosis

Objective

Mannan-binding lectin (MBL), a soluble pattern recognition molecule of the innate immune system, is primarily synthesized in the liver and secreted into the circulation. Low serum level of MBL has been reported to be related to an increased risk of lung diseases. Herein, we aimed to investigate the function of MBL in silicosis-associated pulmonary inflammation.

Methods

Serum collected from silicosis patients was tested for correlation between serum MBL levels and Th17 immunity. In vitro studies were performed to further demonstrated the effect of MBL on Th17 polarization. Silica was intratracheally injected in wild type (WT) or MBL-deficient (MBL^–/–) mice to induce silicosis-associated lung inflammation and fibrosis. Th17 response was evaluated to explore the effect of MBL on silicosis in vivo.

Results

Silicosis patients with high serum MBL levels displayed ameliorative lung function. We demonstrated that serum MBL levels negatively correlated to Th17 cell frequency in silicosis patients. MBL protein markedly reduced expression of IL-17 but enhanced expression of Foxp3 in CD4⁺ T cells in vitro when subjected to Th17 or Treg polarizing conditions, respectively. The presence of MBL during Th17 cell polarization significantly limited aryl hydrocarbon receptor (AhR) expression and suppressed the signal transducer and activator of transcription 3 (STAT3) phosphorylation. Treatment with the AhR antagonist abolished the effect of MBL on Th17 response. Strikingly, MBL directly bound to AhR and affected its nuclear translocation. Furthermore, MBL^–/– mice displayed elevated Th17 cell levels compared with WT mice in response to the silica challenge. The CD4⁺ T lymphocytes from silica-administrated MBL^–/– mice exhibited more AhR expression than the wild-type counterparts.

Conclusion

Our study suggested that MBL limited the Th17 immunity via controlling the AhR/STAT3 pathway, thus providing new insight into silicosis and other inflammatory diseases in patients with MBL deficiency.

The treatment of Qibai Pingfei Capsule on chronic obstructive pulmonary disease may be mediated by Th17/Treg balance and gut-lung axis microbiota

BACKGROUND

Chronic obstructive pulmonary disease (COPD), a prevalent, progressive respiratory disease, has become the third leading cause of death globally. Increasing evidence suggests that intestinal and pulmonary microbiota dysbiosis is associated with COPD. Researchers have shown that T helper (Th) 17/regulatory T (Treg) imbalance is involved in COPD. Qibai Pingfei Capsule (QBPF) is a traditional Chinese medicine used to treat COPD clinically in China. However, the effects of QBPF intervention on the Th17/Treg balance and microbiota in the gut and lung are still poorly understood.

METHODS

This study divided the rats into three groups (n = 8): control, model, and QBPF group. After establishing the model of COPD for four weeks and administering of QBPF for two weeks, Th17 cells, Treg cells, their associated cytokines, transcription factors, and intestinal and pulmonary microbiota of rats were analyzed. Furthermore, the correlations between intestinal and pulmonary microbiota and between bacterial genera and pulmonary function and immune function were measured.

RESULTS

The results revealed that QBPF could improve pulmonary function and contribute to the new balance of Th17/Treg in COPD rats. Meanwhile, QBPF treatment could regulate the composition of intestinal and pulmonary microbiota and improve community structure in COPD rats, suppressing the relative abundance of Coprococcus_2, Prevotella_9, and Blautia in the gut and Mycoplasma in the lung, but accumulating the relative abundance of Prevotellaceae_UCG_003 in the gut and Rikenellaceae_RC9_gut_group in the lung. Additionally, gut-lung axis was confirmed by the significant correlations between the intestinal and pulmonary microbiota. Functional analysis of microbiota showed amino acid metabolism was altered in COPD rats in the gut and lung. Spearman correlation analysis further enriched the relationship between the microbiota in the gut and lung and pulmonary function and immune function in COPD model rats.

CONCLUSIONS

Our study indicated that the therapeutic effects of QBPF may be achieved by maintaining the immune cell balance and regulating the gut-lung axis microbiota, providing references to explore the potential biomarkers of COPD and the possible mechanism of QBPF to treat COPD.

Effects of SOCS1-overexpressing dendritic cells on Th17- and Treg-related cytokines in COPD mice

Background

In this study, we established a chronic obstructive pulmonary disease (COPD) model by stimulating mice with cigarette smoke, and observed the effects of dendritic cells (DCs) overexpressing SOCS1 on Th17, Treg and other related cytokines in peripheral blood, bronchoalveolar lavage fluid and lung tissues of COPD mice.

Methods

After successfully transfecting DCs with overexpressing SOCS1 (DC-SOCS1), the mice were injected with DC-SOCS1 (1 × 10⁶), DC-SOCS1 (2 × 10⁶) and immature DCs (1 × 10⁶) via tail vein on days 1 and 7 of COPD fumigation modeling. After day 28 of modeling, the peripheral blood, BALF and lung tissue samples were extracted from the mice, and the changes of DCs, Th17 and Treg cells and related cytokines were detected by immunohistochemistry, immunofluorescence, HE staining, flow cytometry and ELISA.

Results

The results showed that DC-SOCS1 was able to reduce the secretion of pro-inflammatory factors and increase the anti-inflammatory factors in the COPD mice, and the effect of high concentration (2 × 10⁶ DC-SOCS1) was better than low concentration (1 × 10⁶ DC-SOCS1). Moreover, the intervention effect was significant on day 1 compared with day 7. In the mice injected with DC-SOCS1, the expression of CD83, IL-4, Foxp3, and CCR6 was increased on day 1 than those on day 7, while IL-17 and IFN-γ was decreased.

Conclusions

Intervention of COPD mice with high concentrations of DCs-SOCS1 reduced pro-inflammatory factor secretion and attenuated the inflammatory response in COPD.

Trial registration Not applicable.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01931-1.

The effects of exercise training on the lungs and cardiovascular function of animals exposed to diesel exhaust particles and gases

Air pollution has been identified as one of the main environmental risks to health. Since exercise training seems to act as an anti-inflammatory modulator, our hypothesis is that exercise training prevents damage to respiratory and cardiovascular function caused by diesel exhaust particle (DEP) exposure. This study aimed to evaluate whether aerobic exercise training prior to DEP exposure prevents inflammatory processes in the pulmonary and cardiovascular systems. Therefore, BALB/C male mice were or were not submitted to a 10-week exercise training protocol (5×/week, 1 h/d), and after four weeks, they were exposed to DEP in a chamber with 24 μg/m³ PM2.5 or filtered air. Heart rate variability, lung mechanics and bronchoalveolar lavage fluid, cytokines and polymorphonuclear cells in the lung parenchyma were evaluated. Exposure to DEPs reduced heart rate variability and the elastance of the respiratory system and increased the number of cells in bronchoalveolar lavage fluid, as well as macrophages, neutrophils and lymphocytes, the density of polymorphonuclear cells and the proportion of collagen fibres in the lung parenchyma. Additionally, DEP-exposed animals showed increased expression of IL-23 and IL-12p40 (proinflammatory cytokines) and inducible nitric oxide synthase. Exercise training avoided the increases in all these inflammatory parameters, except the elastance of the respiratory system, the amount of collagen fibres and the expression of inducible nitric oxide synthase. Additionally, trained animals showed increased expression of the anti-inflammatory cytokine IL-1ra. Although our data showed a reduction in proinflammatory markers and an increase in markers of the anti-inflammatory pathway, these changes were not sufficient to prevent damage to the lung and cardiovascular function induced by DEPs. Based on these data, we propose that aerobic exercise training prevents the lung inflammatory process induced by DEPs, although it was not sufficient to avoid chronic damage, such as a loss of lung function or cardiovascular events.

Th17/Treg Imbalance in Chronic Obstructive Pulmonary Disease: Clinical and Experimental Evidence

The imbalance between pro- and anti-inflammatory immune responses mediated by Th17 and Treg cells is deeply involved in the development and progression of inflammation in chronic obstructive pulmonary disease (COPD). Several clinical and experimental studies have described the Th17/Treg imbalance in COPD progression. Due to its importance, many studies have also evaluated the effect of different treatments targeting Th17/Treg cells. However, discrepant results have been observed among different lung compartments, different COPD stages or local and systemic markers. Thus, the data must be carefully examined. In this context, this review explores and summarizes the recent outcomes of Th17/Treg imbalance in COPD development and progression in clinical, experimental and in vitro studies.

Xuanbai Chengqi Decoction Ameliorates Pulmonary Inflammation via Reshaping Gut Microbiota and Rectifying Th17/Treg Imbalance in a Murine Model of Chronic Obstructive Pulmonary Disease

Purpose

Chronic obstructive pulmonary disease (COPD), a prevalent obstructive airway disease, has become the third most common cause of death globally. Xuanbai Chengqi decoction (XBCQ) is a traditional Chinese medicine prescription for the acute exacerbation of COPD. Here, we aimed to reveal the therapeutic effects of XBCQ administration and its molecular mechanisms mediated by Th17/Treg balance and gut microbiota.

Methods

We determined the counts of Th17 and Treg cells in the serum of 15 COPD and 10 healthy subjects. Then, cigarette smoke extract-induced COPD mice were gavaged with low, middle, and high doses of XBCQ, respectively. Weight loss, pulmonary function and inflammation, Th17/Treg ratio, and gut microbiota were measured to evaluate the efficacy of XBCQ on COPD.

Results

COPD patients had a higher Th17/Treg ratio in the serum than healthy controls, which was consistent with the results in the lung and colon of COPD mice. The middle dose of XBCQ (M-XBCQ) significantly decreased the weight loss and improved the pulmonary function (FEV0.2/FVC) in COPD mice. Moreover, M-XBCQ alleviated lung inflammation by rectifying the Th17/Treg imbalance, reducing the expressions of TNF-α, IL-1β, and MMP-9, and suppressing inflammatory cells infiltration. Meanwhile, M-XBCQ greatly improved the microbial homeostasis in COPD mice by accumulating probiotic Gordonibacter and Akkermansia but inhibiting the growth of pathogenic Streptococcus, which showed significant correlations with pulmonary injury.

Conclusion

Oral M-XBCQ could alleviate COPD exacerbations by reshaping the gut microbiota and improving the Th17/Treg balance, which aids in elucidating the mechanism through which XBCQ as a therapy for COPD.

Role of STAT3 Transcription Factor in Pathogenesis of Bronchial Asthma

Bronchial asthma is a heterogeneous chronic inflammatory disease of airways. The studies of molecular and cellular mechanisms of bronchial asthma have established that a wide range of immune (T and B cells, eosinophils, neutrophils, macrophages, etc.) and structural (epithelial and endothelial) cells are involved in its pathogenesis. These cells are activated in response to external stimuli (bacteria, viruses, allergens, and other pollutants) and produce pro-inflammatory factors (cytokines, chemokines, metalloproteinases, etc.), which ultimately leads to the initiation of pathological processes in the lungs. Genes encoding transcription factors of the STAT family (signal transducer and activator of transcription), that includes seven representatives, are involved in the cell activation. Recent studies have shown that the transcription factor STAT3 plays an important role in the activation of the abovementioned cells, thus contributing to the development of asthma. In animal studies, selective inhibition of STAT3 significantly reduces the severity of lung inflammation, which indicates its potential as a therapeutic target. In this review, we describe the mechanisms of STAT3 activation and its role in polarization of Th2/Th17 cells and M2 macrophages, as well as in the dysfunction of endothelial cells, which ultimately leads to development of bronchial asthma symptoms, such as infiltration of neutrophils and eosinophils into the lungs, bronchial hyperreactivity, and the respiratory tract remodeling.

Isoforskolin, an adenylyl cyclase activator, attenuates cigarette smoke-induced COPD in rats

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterized by limited airflow due to pulmonary and alveolar abnormalities from exposure to cigarette smoke (CS). Current therapeutic drugs are limited and the development of novel treatments to prevent disease progression is challenging. Isoforskolin (ISOF) from the plant Coleus forskohlii is an effective activator of adenylyl cyclase (AC) isoforms. Previously we found ISOF could attenuate acute lung injury in animal models, while the effect of ISOF on COPD has not been elucidated.

PURPOSE

In this study, we aimed to evaluate the efficacy of ISOF on COPD and reveal its potential mechanisms.

METHODS

A rat model of COPD was established by long-term exposure to CS, then the rats were orally administered with ISOF (0.5, 1 and 2 mg/kg). The pulmonary function, lung morphology, inflammatory cells and cytokines in serum or bronchoalveolar lavage fluid (BALF) were evaluated. Transcriptomics, proteomics and network pharmacology analysis were utilized to identify potential mechanisms of ISOF. Droplet digital PCR was used to detect the mRNA expression of AC1-10 in donor lung tissues. AC activation was determined in recombinant human embryonic kidney 293 (HEK293) cells stably expressing human AC isoforms. In addition, ISOF caused trachea relaxation ex vivo were assessed in isolated trachea rings from guinea pigs.

RESULTS

ISOF significantly ameliorated pathological damage of lung tissue and improved pulmonary function in COPD rats. ISOF treatment decreased the number of inflammatory cells in peripheral blood, and also the levels of pro-inflammatory cytokines in serum and BALF. Consistent with omics-based analyses, ISOF markedly downregulated the mTOR level in lung tissue. Flow cytometry analysis revealed that ISOF treatment reduced the ratio of Th17/Treg cells in peripheral blood. Furthermore, the expression levels of AC1 and AC2 are relatively higher than other AC isoforms in normal lung tissues, and ISOF could potently activate AC1 and AC2 in vitro and significantly relax isolated guinea pig trachea.

CONCLUSION

Collectively, our studies suggest that ISOF exerts its anti-COPD effect by improving lung function, anti-inflammation and trachea relaxation, which may be related to AC activation, mTOR signaling and Th17/Treg balance.

The Mechanism of Penehyclidine Hydrochloride and Its Effect on the Inflammatory Response of Lung Tissue in Rats with Chronic Obstructive Pulmonary Disease During Mechanical Ventilation

Background

Penehyclidine hydrochloride is a selective antagonist of M1 and M3 receptors. Clinical studies suggest that it is a potential drug for the treatment of chronic obstructive pulmonary disease (COPD). The purpose of this study was to evaluate the effect of penehyclidine hydrochloride on the inflammatory response of lung tissue during mechanical ventilation in rats with COPD and explore the role of the c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) signaling pathway.

Methods

Eight-week-old male Sprague Dawley rats were exposed to cigarette smoke for 30 minutes every day for two months, and on the first and thirtieth days, 200 ug of lipopolysaccharide was injected into the trachea. Two months later, the rats were randomly divided into the control group (C), model group (M), model + normal saline group (N), and penehyclidine hydrochloride group (H) to undergo anesthesia and mechanical ventilation. In group H, 1 mg/kg of penehyclidine hydrochloride was injected intravenously.

Results

The results showed that: ① Compared with group C, the other groups all showed typical chronic obstructive pathological changes in the lung tissue; their wet/dry weight ratio (W/D), TNF-α, JNK, and p-JNK levels increased (P < 0.05), and their interleukin (IL)-10 levels decreased (P < 0.05). ② Compared with group M, there was no significant change in the lung tissue indexes in group N (P > 0.05). ③ Compared with group N, the W/D, TNF-α, JNK, and p-JNK levels in group H decreased (P < 0.05), while the levels of IL-10 increased (P < 0.05).

Conclusion

Penehyclidine hydrochloride can alleviate the pulmonary inflammatory response in rats with COPD undergoing mechanical ventilation. The JNK/SAPK signaling pathway may be involved in this process.

Adult Renal Stem/Progenitor Cells Can Modulate T Regulatory Cells and Double Negative T Cells

Adult Renal Stem/Progenitor Cells (ARPCs) have been recently identified in the human kidney and several studies show their active role in kidney repair processes during acute or chronic injury. However, little is known about their immunomodulatory properties and their capacity to regulate specific T cell subpopulations. We co-cultured ARPCs activated by triggering Toll-Like Receptor 2 (TLR2) with human peripheral blood mononuclear cells for 5 days and 15 days and studied their immunomodulatory capacity on T cell subpopulations. We found that activated-ARPCs were able to decrease T cell proliferation but did not affect CD8⁺ and CD4⁺ T cells. Instead, Tregs and CD3⁺ CD4^- CD8^- double-negative (DN) T cells decreased after 5 days and increased after 15 days of co-culture. In addition, we found that PAI1, MCP1, GM-CSF, and CXCL1 were significantly expressed by TLR2-activated ARPCs alone and were up-regulated in T cells co-cultured with activated ARPCs. The exogenous cocktail of cytokines was able to reproduce the immunomodulatory effects of the co-culture with activated ARPCs. These data showed that ARPCs can regulate immune response by inducing Tregs and DN T cells cell modulation, which are involved in the balance between immune tolerance and autoimmunity.

The BRD4 inhibitor JQ1 protects against chronic obstructive pulmonary disease in mice by suppressing NF-κB activation

OBJECTIVE

To examine the effect of the BRD4 inhibitor JQ1 on mice with chronic obstructive pulmonary disease (COPD) via NF-κB.

METHODS

COPD models constructed by exposure to cigarette smoke and intratracheal instillation of lipopolysaccharides (LPS) in mice were treated with JQ1 (15, 25 or 50 mg/kg). HE staining was performed to observe histopathological changes in the lung tissues. Enzyme-linked immunosorbent assays (ELISAs) were used to measure the levels of IL-10, IFN-γ, IL-17, IL-1β, IL-6, TNF-α, MMP-2, MMP-9, MDA, SOD, T-AOC and HO-1, and gelatin zymography assays were used to examine MMP-2 and MMP-9 activity. A TransAMTM NF-κB p65 detection kit was used to test NF-κB p65/DNA binding activity. Western blotting was conducted to analyze NF-κB p65 in the nucleus and its acetylation.

RESULTS

JQ1 dose-dependently improved the histopathological changes in the lung tissues and decreased the mean linear intercept (MLI), destructive index and inflammatory score of the mice with COPD. The mice with COPD showed increased levels of MMP-2, MMP-9, IFN-γ, IL-17, IL-1β, IL-6 and TNF-α with decreased IL-10 level; these changes were reversed by JQ1 in a dose-dependent manner. In addition, JQ1 reduced the MDA level and increased the SOD, HO-1 and T-AOC levels in mice with COPD, with suppression of NF-κB p65 expression in the nucleus, NF-κB/p65 (Lys310) acetylation and NF-κB p65/DNA binding activity in the lung tissues.

CONCLUSION

The BRD4 inhibitor JQ1 can downregulate MMP-2 and MMP-9 expression, reduce inflammatory responses, and alleviate oxidative stress in mice with COPD, and this mechanism might be related to the inhibition of NF-κB.

Screening of Lactobacillus salivarius strains from the feces of Chinese populations and the evaluation of their effects against intestinal inflammation in mice

Lactobacillus salivarius is a species of lactic acid bacteria with probiotic potency. Compared to such well-known probiotics as L. rhamnosus and L. casei, the genomic characteristics and health-beneficial effects of L. salivarius are inadequately researched. For this study, a medium with enhanced selectivity for the isolation of L. salivarius was developed by optimizing the carbon source and antibiotics in the medium. Seventy-three L. salivarius strains were isolated from 472 fecal samples from Chinese populations, and their pan-genomic and phylogenetic characterizations were analyzed. Three strains (L. salivarius HN26-4, NT4-8, and FXJCJ7-2) that were clearly categorized in different sub-phylotypes of the phylogenetic tree were randomly selected for further studies. Compared to the other two tested strains, L. salivarius FXJCJ7-2 showed higher tolerance to simulated gastrointestinal tract conditions and more significant anti-inflammatory effects in lipopolysaccharides (LPS)-treated RAW264.7 murine macrophages. This strain was also more effective in reversing LPS-induced alterations in gut barrier function, colonic histopathology, Treg/Th-17 balance, immunomodulatory indicators, nuclear factor kappa B pathway activation, and the intestinal microenvironment of the mice than the other two tested strains. Comparative genomic analysis indicated that these protective effects may be related to the specific genes of L. salivarius FXJCJ7-2 that were involved in the tolerance to the gastrointestinal environment, short-chain fatty acid production, and host-bacterium interaction.

Th17/Treg imbalance in COPD development: suppressors of cytokine signaling and signal transducers and activators of transcription proteins

Th17/Treg imbalance contributes to chronic obstructive pulmonary disease (COPD) development and progression. However, intracellular signaling by suppressor of cytokine signaling (SOCS) 1 and SOCS3 and the proteins signal transducer and activator of transcription (STAT) 3 and STAT5 that orchestrate these imbalances are currently poorly understood. Thus, these proteins were investigated in C57BL/6 mice after exposure to cigarette smoke (CS) for 3 and 6 months. The expression of interleukin was measured by ELISA and the density of positive cells in peribronchovascular areas was quantified by immunohistochemistry. We showed that exposure to CS in the 3rd month first induced decreases in the numbers of STAT5+ and pSTAT5+ cells and the expression levels of TGF-β and IL-10. The increases in the numbers of STAT3+ and pSTAT3+ cells and IL-17 expression occurred later (6th month). These findings corroborate the increases in the number of SOCS1+ cells in both the 3rd and 6th months, with concomitant decreases in SOCS3+ cells at the same time points. Our results demonstrated that beginning with the initiation of COPD development, there was a downregulation of the anti-inflammatory response mediated by SOCS and STAT proteins. These results highlight the importance of intracellular signaling in Th17/Treg imbalance and the identification of possible targets for future therapeutic approaches.

Bufei Yishen Formula Restores Th17/Treg Balance and Attenuates Chronic Obstructive Pulmonary Disease via Activation of the Adenosine 2a Receptor

Bufei Yishen formula (BYF) is a Traditional Chinese Medicine (TCM) reported to ameliorate chronic obstructive pulmonary disease (COPD) by regulating the balance between T helper (Th) 17 and regulatory T (Treg) cells. However, its mechanism remains unknown. Therefore, this study aimed to explore the underlying mechanisms of BYF. Naïve CD4+ T cells were exposed to anti-CD3, anti-CD28, transforming growth factor (TGF)-β, and/or interleukin (IL)-6 to promote their differentiation into Th17 or Treg cells. A rat model of cigarette smoke- and bacterial infection-induced COPD was established and orally treated with BYF and/or an adenosine 2a receptor (A2aR) antagonist. Then, the rats were sacrificed, their lung tissues were removed for histological analysis, and their spleens were collected to evaluate Th17 and Treg cells. The results showed that BYF significantly suppressed Th17 cell differentiation and its related cytokines and enhanced Treg cell differentiation and its related cytokines. In addition, BYF activated the A2aR, increased the levels of p-signal transducer and activator of transcription (STAT)5, and decreased the level of p-STAT3 in Treg and Th17 cells. The A2aR antagonist suppressed the changes induced by BYF treatment in Th17 and Treg cells. Furthermore, the A2aR antagonist diminished the therapeutic effect of BYF on COPD, as indicated by the lung injury scores, bronchiole wall thickness, small pulmonary vessels wall thickness, bronchiole stenosis, alveolar diameters, decrease in inflammatory cytokines, increase in alveolar number, and lung functions. Similarly, the A2aR antagonist reversed the effects of BYF on the proportion of Th17 and Treg cells in the spleen. Additionally, BYF increased the protein and mRNA levels of A2aR and regulated the phosphorylation of STAT3 and STAT5 in spleen and lung tissues, which were inhibited by cotreatment with the A2aR antagonist. In conclusion, this study suggested that BYF exhibited its anti-COPD efficacy by restoring the Th17/Treg balance via activating A2aR, which may provide evidence for the clinical application of BYF in the treatment of COPD.

Low-level laser therapy attenuates lung inflammation and airway remodeling in a murine model of idiopathic pulmonary fibrosis: Relevance to cytokines secretion from lung structural cells

Idiopathic pulmonary fibrosis (IPF) is a progressive and chronic inflammatory disease with a poor prognosis and very few available treatment options. Low-level laser therapy (LLLT) has been gaining prominence as a new and effective anti-inflammatory and immunomodulatory agent. Can lung inflammation and the airway remodeling be regulated by LLLT in an experimental model of IPF in C57Bl/6 mice? The present study investigated if laser attenuates cellular migration to the lungs, the airway remodeling as well as pro-fibrotic cytokines secretion from type II pneumocytes and fibroblasts. Mice were irradiated (780 nm and 30 mW) and then euthanized fifteen days after bleomycin-induced lung fibrosis. Lung inflammation and airway remodeling were evaluated through leukocyte counting in bronchoalveolar lavage fluid (BALF) and analysis of collagen in lung, respectively. Inflammatory cells in blood were also measured. For in vitro assays, bleomycin-activated fibroblasts and type II pneumocytes were irradiated with laser. The pro- and anti-inflammatory cytokines level in BALF as well as cells supernatant were measured by ELISA, and the TGFβ in lung was evaluated by flow cytometry. Lung histology was used to analyze collagen fibers around the airways. LLLT reduced both migration of inflammatory cells and deposition of collagen fibers in the lungs. In addition, LLLT downregulated pro-inflammatory cytokines and upregulated the IL-10 secretion from fibroblasts and pneumocytes. Laser therapy greatly reduced total lung TGFβ. Systemically, LLLT also reduced the inflammatory cells counted in blood. There is no statistical difference in inflammatory parameters studied between mice of the basal group and the laser-treated mice. Data obtained indicate that laser effectively attenuates the lung inflammation, and the airway remodeling in experimental pulmonary fibrosis is driven to restore the balance between the pro- and anti-inflammatory cytokines in lung and inhibit the pro-fibrotic cytokines secretion from fibroblasts.