Effective-components combination improves airway remodeling in COPD rats by suppressing M2 macrophage polarization via the inhibition of mTORC2 activity

Involvement of M2 macrophages polarization in PM2.5-induced COPD by upregulating MMP12 via IL4/STAT6 pathway

Biomass-related airborne fine particulate matter (PM2.5) is an important risk factor for chronic obstructive pulmonary disease (COPD). Macrophage polarization has been reported to be involved in PM2.5-induced COPD, but the dynamic characteristics and underlying mechanism of this process remain unclear. Our study established a PM2.5-induced COPD mouse model and revealed that M2 macrophages predominantly presented after 4 and 6 months of PM2.5 exposure, during which a notable increase in MMP12 was observed. Single cell analysis of lung tissues from COPD patients and mice further revealed that M2 macrophages were the dominant macrophage subpopulation in COPD, with MMP12 being involved as a hub gene. In vitro experiments further demonstrated that PM2.5 induced M2 polarization and increased MMP12 expression. Moreover, we found that PM2.5 increased IL-4 expression, STAT6 phosphorylation and nuclear translocation. Nuclear pSTAT6 then bound to the MMP12 promoter region. Furthermore, the inhibition of STAT6 phosphorylation effectively abrogated the PM2.5-induced increase in MMP12. Using a coculture system, we observed a significantly reduced level of E-cadherin in alveolar epithelial cells cocultured with PM2.5-exposed macrophages, while the decrease in E-cadherin was reversed by the addition of an MMP12 inhibitor to the co-culture system. Taken together, these findings indicated that PM2.5 induced M2 macrophage polarization and MMP12 upregulation via the IL-4/STAT6 pathway, which resulted in alveolar epithelial barrier dysfunction and excessive extracellular matrix (ECM) degradation, and ultimately led to COPD progression. These findings may help to elucidate the role of macrophages in COPD, and suggest promising directions for potential therapeutic strategies.

Effective-Component Compatibility of Bufei Yishen Formula III Suppresses Mitochondrial Oxidative Damage in COPD: Via Pkm2/Nrf2 Pathway

Purpose

The main objective of this study was to explore the mechanism of effective component compatibility of Bufei Yishen formula III (ECC-BYF III) in inhibiting mitochondrial oxidative stress in a rat model of chronic obstructive pulmonary disease (COPD).

Methods

A549 cells exposed to cigarette smoke extract (CSE) were used to establish a model of mitochondrial oxidative damage. The cells were treated with the plasmid encoding Pkm2 and the enzymes and proteins involved in oxidative stress and mitochondrial function were measured. A rat model of COPD was established using CS and bacteria. Two different treatments were established, ECC-BYF III (5.5 mg/kg/d) and N-acetylcysteine (54 mg/kg/day). Animals were tested for pulmonary function (Vt, PEF, FVC, FEV0.1s and Cdyn) after eight weeks of therapy and were sacrificed. Pulmonary H&E staining was performed, and the total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and malondialdehyde (MDA) content were measured. The mitochondrial function was also examined. Furthermore, the Pkm2/Nrf2 signaling pathway was evaluated.

Results

Overexpression of Pkm2 dramatically ameliorated the CS-induced mitochondrial oxidative damage. Further studies indicated that ECC-BYF III significantly improved mitochondrial function and inhibited oxidative stress in the lung tissues of COPD rats. Moreover, it can upregulate mitochondrial respiratory chain enzyme activity. ECC-BYF III also decreased the MDA content and increased T-SOD, GSH-Px, and T-AOC expression to facilitate oxidative homeostasis. Finally, our results indicated that the Pkm2/Nrf2 pathway is regulated by ECC-BYF III in A549 cells and lung tissue.

Conclusion

These results indicate that ECC-BYF III exerts a strong effective therapeutic effect against cigarette smoke combined with bacteria-induced COPD in rats by activating the Pkm2/Nrf2 signaling pathway and restoring mitochondrial oxidative stress. Although more in vivo animal model research is needed to confirm these findings, this study contributes new data to support the conventional usage of ECC-BYF III.

Mesenchymal Stromal Cell Therapy Alleviates Ovalbumin-Induced Chronic Airway Remodeling by Suppressing M2 Macrophage Polarization

Chronic asthma is characterized by airway hyperresponsiveness, inflammation, and remodeling. Previous studies have shown that mesenchymal stromal/stem cells (MSCs) exert anti-inflammatory effects on asthma via regulation of the immune cells. However, the therapeutic mechanism of MSCs, especially the mechanism of airway remodeling in chronic asthma, remains to be elucidated. Here, we aimed to investigate the therapeutic effect of MSCs on airway remodeling in chronic asthma and explored the mechanisms by analyzing the polarization phenotype of macrophages in the lungs. We established a mouse model of chronic asthma induced by ovalbumin (OVA) and evaluated the effect of MSCs on airway remodeling. The data showed that MSCs treatment before the challenge exerted protective effects on OVA-induced chronic asthma, i.e., decreased the inflammatory cell infiltration, Th2 cytokine levels, subepithelial extracellular matrix deposition, and transforming growth factor β (TGF-β)/Smad signaling. Additionally, we found that MSCs treatment markedly suppressed macrophage M2 polarization in lung tissue. At the same time, MSCs treatment inhibited NF-κB p65 nuclear translocation, ER stress, and oxidative stress in the OVA-induced chronic allergic airway remodeling mice model. In conclusion, these results demonstrated that MSCs treatment prevents OVA-induced chronic airway remodeling by suppressing macrophage M2 polarization, which may be associated with the dual inhibition of ER stress and oxidative stress. This discovery may provide a new theoretical basis for the future clinical application of MSCs.

Recent advances in the therapeutic potential of nobiletin against respiratory diseases

BACKGROUND

Nobiletin is a natural polymethoxylated flavonoid widely present in citrus fruit peels. It has been demonstrated to exert the effects of anti-tumor, anti-inflammation, anti-oxidative, anti-apoptotic and improve cardiovascular function. Increasing evidences suggest that nobiletin plays an important role in respiratory diseases (RDs) treatment.

OBJECTIVE

This review aimed to investigate the therapeutic potential of nobiletin against RDs, such as lung cancer, COPD, pulmonary fibrosis, asthma, pulmonary infection, acute lung injury, coronavirus disease 2019, and pulmonary arterial hypertension.

METHODS

We retrieved extensive literature of relevant literatures in English until June 26, 2023 from the database of PubMed, Web of Science, and Scopus databases. The keywords of "nobiletin and lung", "nobiletin and respiratory disease", "nobiletin and chronic respiratory diseases", "nobiletin and metabolites", "nobiletin and pharmacokinetics", "nobiletin and toxicity" were searched in pairs. A total of 298 literatures were retrieved from the above database. After excluding the duplicates and reviews, 53 were included in the current review.

RESULTS

We found that the therapeutic mechanisms are based on different signaling pathways. Firstly, nobiletin inhibited the proliferation and suppressed the invasion and migration of cancer cells by regulating the related pathway or key target, like Bcl-2, PD-L1, PARP, and Akt/GSK3β/β-catenin in lung cancer treatment. Secondly, nobiletin treats COPD and ALI by targeting classical signaling pathway mediating inflammation. Besides, the available findings show that nobiletin exerts the effect of PF treatment via regulating mTOR pathway.

CONCLUSIONS

With the wide range of pharmacological activities, high efficiency and low toxicity, nobiletin can be used as a potential agent for preventing and treating RDs. These findings will contribute to further research on the molecular mechanisms of nobiletin and facilitate in-depth studies on nobiletin at both preclinical and clinical levels for the treatment of RDs.

Macrophage Polarization and Functions in Pathogenesis of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD), the major leading cause of mortality worldwide, is a progressive and irreversible respiratory condition characterized by peripheral airway and lung parenchymal inflammation, accompanied by fibrosis, emphysema, and airflow limitation, and has multiple etiologies, including genetic variance, air pollution, and repetitive exposure to harmful substances. However, the precise mechanisms underlying the pathogenesis of COPD have not been identified. Recent multiomics-based evidence suggests that the plasticity of alveolar macrophages contributes to the onset and progression of COPD through the coordinated modulation of numerous transcription factors. Therefore, this review focuses on understanding the mechanisms and functions of macrophage polarization that regulate lung homeostasis in COPD. These findings may provide a better insight into the distinct role of macrophages in COPD pathogenesis and perspective for developing novel therapeutic strategies targeting macrophage polarization.

Immune Dysregulation in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a disease whose incidence increase with age and is characterised by chronic inflammation and significant immune dysregulation. Inhalation of toxic substances cause oxidative stress in the lung tissue as well as airway inflammation, under the recruitment of chemokines, immune cells gathered and are activated to play a defensive role. However, persistent inflammation damages the immune system and leads to immune dysregulation, which is mainly manifested in the reduction of the body's immune response to antigens, and immune cells function are impaired, further destroy the respiratory defensive system, leading to recurrent lower respiratory infections and progressive exacerbation of the disease, thus immune dysregulation play an important role in the pathogenesis of COPD. This review summarizes the changes of innate and adaptive immune-related cells during the pathogenesis of COPD, aiming to control COPD airway inflammation and improve lung tissue remodelling by regulating immune dysregulation, for further reducing the risk of COPD progression and opening new avenues of therapeutic intervention in COPD.

Metabolic regulation of the Th17/Treg balance in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a long-lasting and inflammatory autoimmune condition affecting the gastrointestinal tract, impacting millions of individuals globally. The balance between T helper 17 (Th17) cells and regulatory T cells (Tregs) is pivotal in the pathogenesis and progression of IBD. This review summarizes the pivotal role of Th17/Treg balance in maintaining intestinal homeostasis, elucidating how its dysregulation contributes to the development and exacerbation of IBD. It comprehensively synthesizes the current understanding of how dietary factors regulate the metabolic pathways influencing Th17 and Treg cell differentiation and function. Additionally, this review presents evidence from the literature on the potential of dietary regimens to regulate the Th17/Treg balance as a strategy for the management of IBD. By exploring the intersection between diet, metabolic regulation, and Th17/Treg balance, the review reveals innovative therapeutic approaches for IBD treatment, offering a promising perspective for future research and clinical practice.

Periodontitis aggravates COPD through the activation of γδ T cell and M2 macrophage

Chronic obstructive pulmonary disease (COPD) is a chronic systemic inflammatory disease with high morbidity and mortality. Periodontitis exacerbates COPD progression; however, the immune mechanisms by which periodontitis affects COPD remain unclear. Here, by constructing periodontitis and COPD mouse models, we demonstrated that periodontitis and COPD could mutually aggravate disease progression. For the first time, we found that the progression was associated with the activation of γδ T cells and M2 macrophages, and M2 polarization of macrophages was affected by γδ T cells activation. In the lung tissues of COPD with periodontitis, the activation of γδ T cells finally led to the increase of IL 17 and IFN γ expression and M2 macrophage polarization. Furthermore, we found that the periodontitis-associated bacteria Porphyromonas gingivalis (P. gingivalis) promoted the activation of γδ T cells and M2 macrophages ex vivo. The data from clinical bronchoalveolar lavage fluid (BALF) samples were consistent with the in vivo and ex vivo experiments. For the first time, our results identified the crucial role of γδ T-M2 immune mechanism in mediating periodontitis-promoted COPD progression. Therefore, targeting at periodontitis treatment and the γδ T-M2 immune mechanism might provide a new practical strategy for COPD prevention or control.IMPORTANCEPeriodontitis exacerbates chronic obstructive pulmonary disease (COPD) progression. For the first time, the current study identified that the impact of periodontitis on COPD progression was associated with the activation of γδ T cells and M2 macrophages and that M2 polarization of macrophages was affected by γδ T cells activation. The results indicated that targeting at periodontitis treatment and the γδ T-M2 immune mechanism might provide a new practical strategy for COPD prevention or control.

The Role of Mitochondrial Quality Control in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity, mortality, and health care use worldwide with heterogeneous pathogenesis. Mitochondria, the powerhouses of cells responsible for oxidative phosphorylation and energy production, play essential roles in intracellular material metabolism, natural immunity, and cell death regulation. Therefore, it is crucial to address the urgent need for fine-tuning the regulation of mitochondrial quality to combat COPD effectively. Mitochondrial quality control (MQC) mainly refers to the selective removal of damaged or aging mitochondria and the generation of new mitochondria, which involves mitochondrial biogenesis, mitochondrial dynamics, mitophagy, etc. Mounting evidence suggests that mitochondrial dysfunction is a crucial contributor to the development and progression of COPD. This article mainly reviews the effects of MQC on COPD as well as their specific regulatory mechanisms. Finally, the therapeutic approaches of COPD via MQC are also illustrated.

MTOR Suppresses Cigarette Smoke-Induced Airway Inflammation and MMP12 Expression in Macrophage in Chronic Obstructive Pulmonary Disease

Background

Macrophage-derived matrix metalloproteinase 12 (MMP12) can cause destruction of lung tissue structure and plays a significant role in the development and progression of chronic obstructive pulmonary disease (COPD). MTOR is a serine/threonine kinase that plays a crucial role in cell growth and metabolism. The activity of MTOR in the lung tissues of COPD patients also shows significant changes. However, it is unclear whether MTOR can regulate the development and progression of COPD by controlling MMP12. This study primarily investigates whether MTOR in macrophages can affect the expression of MMP12 and participate in the progression of COPD.

Methods

We tested the changes in MTOR activity in macrophages exposed to cigarette smoke (CS) both in vivo and in vitro. Additionally, we observed the effect of MTOR on the expression of MMP12 in macrophages and on lung tissue inflammation and structural damage in mice, both in vivo and in vitro, using MTOR inhibitors or gene knockout mice. Finally, we combined inhibitor treatment with gene knockout to demonstrate that MTOR primarily mediates the expression of MMP12 through the NF-κB signaling pathway.

Results

Exposure to CS can enhance MTOR activity in mouse alveolar macrophages. Inhibiting the activity of MTOR or suppressing its expression leads to increased expression of MMP12. Myeloid-specific knockout of MTOR expression can promote the occurrence of CS-induced pulmonary inflammation and emphysema in mice. Inhibiting the activity of NF-κB can eliminate the effect of MTOR on MMP12.

Conclusion

Macrophage MTOR can reduce the expression of MMP12 by inhibiting NF-κB, thereby inhibiting the occurrence of COPD inflammation and destruction of lung tissue structure. Activating the activity of macrophage MTOR may be beneficial for the treatment of COPD.

Rapamycin-based inhaled therapy for potential treatment of COPD-related inflammation: production and characterization of aerosolizable nano into micro (NiM) particles

Our paper describes the production and characterization of inhalable microparticles loaded with nanoparticles for the lung administration of rapamycin (Rapa). In detail, core-shell lipid/polymer hybrid nanoparticles loaded with Rapa (Rapa@Man-LPHNPs) were produced with mean size of about 128 nm and slightly negative ζ potential (-13.8 mV). A fluorescent graft polyaspartamide-poly(lactic-co-glycolic acid) copolymer (PHEA-g-RhB-g-PLGA) for use as the polymeric core was obtained by nanoprecipitation, while an appropriate mixture of DPPC and mannosylated phospholipid (DSPE-PEG2000-Man) was used to provide the macrophage-targeting lipid shell. The successful formation of Rapa@Man-LPHNPs was confirmed by TEM and DSC analyses. The loaded drug (4.3 wt% of the total weight) was slowly released from the polymeric core and protected from hydrolysis, with the amount of intact drug after 24 h of incubation in the medium being equal to 74 wt% (compared to 40% when the drug is freely incubated at the same concentration). To obtain a formulation administrable by inhalation, Rapa@Man-LPHNPs were entrapped inside PVA : LEU microparticles by using the nano into micro (NiM) strategy, specifically by spray drying (SD) in the presence of a pore-forming agent. In this way, NiM particles with geometric and theoretical aerodynamic diameters equal to 4.52 μm and 3.26 μm, respectively, were obtained. Furthermore, these particles showed optimal nebulization performance, having an FPF and an MMAD equal to 27.5% and 4.3 μm, respectively.

Effective-component compatibility of Bufei Yishen formula alleviates chronic obstructive pulmonary disease inflammation by regulating GSK3β-mediated NLRP3 inflammasome activation

Glycogen synthase kinase 3β (GSK3β) has been associated with sensing many different stimuli to trigger the NLRP3 inflammasome, which plays a crucial role in promoting the inflammatory response in diseases, including chronic obstructive pulmonary disease (COPD). Bufei Yishen formula (BYF), a traditional Chinese herbal medicine, has beneficial effects on COPD. Effective-component compatibility of BYF (ECC-BYF), optimized from BYF, is equally effective as BYF in inhibiting COPD inflammation. However, the exact mechanism by which ECC-BYF regulates the activation of NLRP3 inflammasome to inhibit COPD inflammation remains unclear. Hence, we investigated the mechanisms underlying the alleviation of COPD inflammation by ECC-BYF through the inhibition of GSK3β-mediated NLRP3 inflammasome activation by experimental rat model of COPD and lipopolysaccharide/adenosine triphosphate (LPS/ATP) induced macrophages. The data showed that ECC-BYF significantly improved the lung function, attenuated histopathological damage, and alleviated inflammatory cell infiltration and alveolar destruction. Further, it significantly inhibited inflammatory cytokine production and downregulated the phosphorylation of GSK3β by inhibiting the activation of NLRP3 inflammasome in the rat model of COPD. Moreover, ECC-BYF suppressed the activation of the NLRP3 inflammasome by increasing the phosphorylation at serine 9 and decreasing the phosphorylation at tyrosine 216 of GSK3β, followed by the inhibition of IL-1β secretion in macrophages. Together, ECC-BYF effectively ameliorates COPD by suppressing inflammation, which is dependent on the regulation of GSK3β-mediated NLRP3 inflammasome activation.

Effective-compound combination of Bufei Yishen formula III combined with ER suppress airway mucus hypersecretion in COPD rats: via EGFR/MAPK signaling

BACKGROUND

The aim of this study was to explore the combined efficacy ofeffective-component compatibility of Bufei Yishen formula III (ECC-BYF III) and exercise rehabilitation (ER) in inhibiting airway mucus hypersecretion in a chronic obstructive pulmonary disease (COPD) rat model.

METHODS

A total of 48 SD rats were divided into control, model, acetylcysteine (NAC), ECC-BYF III, ER, and ECC-BYF III + ER groups (n=8). COPD rats were exposed to cigarette smoke and bacteria for 8 weeks and administered various treatments over the next eight weeks. Rats were euthanized at week 17 after pulmonary function testing. Pathological examination of lung tissues was performed. IL-6 and IL-10 levels were measured in bronchoalveolar lavage fluid (BALF) and protein levels of MUC5AC, MUC5B, AQP-5, EGFR, ERK, JNK, and p38 were measured in lung tissues.

RESULTS

Improved pulmonary function and pathological changes were observed in ECC-BYF III, ECC-BYF III + ER, and NAC groups. ECC-BYF III and ECC-BYF III + ER had greater mean alveolar number (MAN) compared with NAC. Lung inflammation and goblet cell generation were reduced and MUC5AC, MUC5B and AQP-5 expressions were lower in all treatment groups. ECC-BYF III has more significant effect on MUC5AC than ER and NAC. ECC-BYFIII + ER had a greater effect on suppressing IL-6 in BALF compared with other treatments. ECC-BYFIII, ER, and ECC-BYF III + ER reduced EGFR, ERK, JNK, and p38 phosphorylated protein levels. ECC-BYFIII+ER had a greater effect on p-JNK and p-p38 than ECC-BYFIII and NAC.

CONCLUSION

ECC-BYF III, ER, and ECC-BYF III + ER have efficacy in inhibiting airway mucus hypersecretion with improved pulmonary function and pathological changes. ECC-BYF III had a greater effect in improving MAN and MUC5AC in lung tissue. ECC-BYF III+ER had a greater effect in alleviating pulmonary pathology and inflammation. These effects may be mediated by inhibition of the EGFR/MAPK pathway.

Maintenance of airway epithelial barrier integrity via the inhibition of AHR/EGFR activation ameliorates chronic obstructive pulmonary disease using effective-component combination

BACKGROUND

Airway epithelial barrier dysfunction is highly related to the pathogenesis of chronic obstructive pulmonary disease (COPD). Effective-component combination (ECC) derived from Bufei Yishen formula (BYF) is an effective treatment regimen for patients with COPD and has previously been found to attenuate COPD and airway epithelial inflammation in rats.

PURPOSE

To determine the mechanism underlying the protective effects of ECC-BYF against the disruption of the airway epithelial barrier in COPD.

METHODS

The protective effects of ECC-BYF on the airway epithelial barrier were investigated in a rat COPD model. BEAS-2B epithelial cells were stimulated with cigarette smoke extract (CSE) to determine the direct effects of ECC-BYF on epithelial barrier function and aryl hydrocarbon receptor (AHR)/ epidermal growth factor receptor (EGFR) signaling.

RESULTS

The results revealed that ECC-BYF attenuated COPD in rats and maintained the airway epithelial barrier by upregulating the expression of apical junction proteins, including occludin (OCC), zonula occludens (ZO)-1, and E-cadherin (E-cad). In BEAS-2B cells, ECC-BYF decreased permeability, increased transepithelial electrical resistance, and prevented the decrease in OCC, ZO-1, and E-cad expression induced by CSE exposure. In addition, transcriptomics and network analysis revealed that the protective effects of ECC-BYF may be related to multiple signaling pathways, including ErbB, AHR, and PI3K-Akt-mTOR pathways. ECC-BYF treatment suppressed the protein levels of p-EGFR and p-ERK1/2 and mRNA levels of CYP1A1 in CSE-exposed BEAS-2B cells as well as the protein levels of p-EGFR, p-ERK1/2, and CYP1A1 in the lungs of rats with COPD. In BEAS-2B cells, the AHR agonist FICZ weakened the protective effect of ECC-BYF on the epithelial barrier by suppressing the increase in ZO-1 and OCC expression induced by ECC-BYF and preventing the inhibitory effects of ECC-BYF on EGFR phosphorylation.

CONCLUSIONS

This is the first study to demonstrate the protective effect of ECC-BYF on airway epithelial barrier function. The underlying mechanism may be associated with the suppression of the AHR/EGFR pathway to promote apical junction protein adhesion.

Tissue Inhibitor of Metalloproteinase-1 Enhances Eosinophilic Airway Inflammation in Severe Asthma

PURPOSE

Severe asthma (SA) is characterized by persistent airway inflammation and remodeling, followed by lung function decline. The present study aimed to evaluate the role of tissue inhibitor of metalloproteinase-1 (TIMP-1) in the pathogenesis of SA.

METHODS

We enrolled 250 adult asthmatics (54 with SA and 196 with non-SA) and 140 healthy controls (HCs). Serum TIMP-1 levels were determined by enzyme-linked immunosorbent assay. The release of TIMP-1 from airway epithelial cells (AECs) in response to stimuli as well as the effects of TIMP-1 on the activations of eosinophils and macrophages were evaluated in vitro and in vivo.

RESULTS

Significantly higher levels of serum TIMP-1 were noted in asthmatics than in HCs, in the SA group than in non-SA group, and in the type 2 SA group than in non-type 2 SA group (P < 0.01 for all). A negative correlation between serum TIMP-1 and FEV₁% values (r = -0.400, P = 0.003) was noted in the SA group. In vitro study demonstrated that TIMP-1 was released from AECs in response to poly I:C, IL-13, eosinophil extracellular traps (EETs) and in coculture with eosinophils. TIMP-1-stimulated mice showed eosinophilic airway inflammation, which was not completely suppressed by steroid treatment. In vitro and in vivo functional studies showed that TIMP-1 directly activated eosinophils and macrophages, and induced the release of EETs and macrophages to polarize toward M2 subset, which was suppressed by anti-TIMP-1 antibody.

CONCLUSIONS

These findings suggest that TIMP-1 enhances eosinophilic airway inflammation and that serum TIMP-1 may be a potential biomarker and/or therapeutic target for type 2 SA.

Tong Sai granules improves AECOPD via regulation of MAPK-SIRT1-NF-κB pathway and cellular senescence alleviation

ETHNOPHARMACOLOGICAL RELEVANCE

Tong Sai granules (TSG) a traditional Chinese medicine, are used to treat acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Cellular senescence is considered the mechanism underlying AECOPD progression.

AIM OF THE STUDY

This study aimed to investigate the therapeutic mechanisms of TSG in an AECOPD rat model (established using cigarette smoke exposure and bacterial infection) and focused on the inhibition of cellular senescence in vivo and in vitro.

MATERIALS AND METHODS

Histological changes and levels of inflammatory cytokines, matrix metalloproteinases (MMPs), p53, and p21 were determined. A cellular senescence model was established by challenging airway epithelial cells with cigarette smoke extract (CSE) and lipopolysaccharide (LPS). Quantitative PCR, western blotting, and immunofluorescence were used to measure mRNA and protein levels. Additionally, UPLC-Q-Extractive-Orbitrap MS analysis, network analysis, and transcriptomics were used to analyze the potential compounds and molecular mechanisms of TSG.

RESULTS

The results showed that oral administration of TSG significantly reduced the severity of AECOPD in rats by ameliorating lung function decline and pathological injuries and increasing the levels of C-reactive protein and serum amyloid A, two well-known proinflammatory mediators of the acute phase response. Oral TSG administration also decreased the expression levels of proinflammatory cytokines (e.g., IL-6, IL-1β, and TNF-α), MMPs (e.g., MMP-2 and MMP-9), critical regulators of senescence such as p21 and p53, and the apoptotic marker γH2AX, all of which are factors in cellular senescence in lung tissue. TSG4 was isolated from TSGs using macroporous resin and found to significantly suppress cellular senescence in CSE/LPS-induced bronchial epithelial cells. Furthermore, 26 of 56 compounds identified in TSG4 were used to predict 882 potential targets. Additionally, 317 differentially expressed genes (DEGs) were detected in CSE/LPS-treated bronchial epithelial cells. Network analysis of the 882 targets and 317 DEGs revealed that TSG4 regulated multiple pathways, among which the mitogen-activated protein kinase-sirtuin 1-nuclear factor kappa B (MAPK-SIRT1-NF-κB) pathway is important in terms of antisenescent mechanisms. Moreover, in CSE/LPS-induced bronchial epithelial cells, p-p38, p-ERK1/2, p-JNK, and p-p65 levels were increased and SIRT1 levels were decreased after TSG4 treatment. Additionally, oral TSG administration decreased p-p38 and p-p65 levels and increased SIRT1 levels in the lung tissues of AECOPD model rats.

CONCLUSION

Collectively, these results indicate that TSGs ameliorate AECOPD by regulating the MAPK-SIRT1-NF-κB signaling pathway and subsequently suppressing cellular senescence.

PPARγ inhibits small airway remodeling through mediating the polarization homeostasis of alveolar macrophages in COPD

The role of Peroxisome Proliferator-Activated Receptor-γ (PPARγ) in alveolar macrophages(AMs) polarization homeostasis is closely associated with airway remodeling in COPD, but the definite mechanism remains unclear. In this study, elevated percentage of M1-type AMs and the expression of functionally cytokines were found in COPD patients and mice, which closely related to the disease severity. PPARγ was markedly up-regulated in M2-type AMs and down-regulated in M1-type AMs, and was associated with disease severity in COPD. Co-cultured with M1- or M2-type AMs promoted the epithelial-mesenchymal transition (EMT) of airway epithelial cells and the proliferation of airway smooth muscle cells. Moreover, airway remodeling and functional damage were observed in both IL4R-/- COPD mice with runaway M1-type AMs polarization and TLR4-/- COPD mice with runaway M2-type AMs polarization. Cigarette extract (CS) or lipopolysaccharide (LPS) stimulated PPARγ-/- AMs showed more serious polarization disorder towards M1, as well as CS induced PPARγ-/- COPD mice, which led to more severe airway inflammation, lung function damage, and airway remodeling. Treatment with PPARγ agonist significantly improved the polarization disorder and function activity in CS/LPS stimulated-AMs by inhibiting the JAK-STAT, MAPK and NF-κB pathways, and alleviated the airway inflammation, restored the lung function and suppressed airway remodeling in CS induced-COPD mice. Our research demonstrates that polarization homeostasis of AMs mediated by PPARγ has the protective effect in airway remodeling, and may be a novel therapeutic target for the intervention and treatment of airway remodeling in COPD.

MicroRNA Let-7 Induces M2 Macrophage Polarization in COPD Emphysema Through the IL-6/STAT3 Pathway

Background

M2 polarized macrophages are involved in the occurrence and development of emphysema in COPD patients. However, the molecular mechanism of M2 macrophage polarization is still unclear. This study investigated the molecular mechanism of let-7 differentially expressed in bronchial epithelial cells of COPD patients participating in COPD emphysema by regulating the expression of IL-6 and inducing M2 polarization of alveolar macrophages (AM).

Materials and Methods

We measured let-7c expression in human lung tissue, serum and the lung tissue of cigarette smoke (CS)-exposed mice by qRT‒PCR. We observed the M1/M2 AM polarization in the lungs of COPD patients and COPD model mice by immunofluorescence analysis. Western blotting was used to determine the expression of MMP9/12 in the lung tissue of COPD patients and CS-exposed mice. An in vitro experiment was performed to determine the molecular mechanism of let-7c-induced macrophage polarization.

Results

Let-7c expression was downregulated in COPD patients, CS-exposed mice, and CS extract (CSE)-treated human bronchial epithelial (HBE) cells. AMs in COPD patients and CS-exposed mice were dominated by the M2 type, and the release of MMP9/12 was increased. In vitro, the transfection of mimics overexpressing let-7 or the use of tocilizumab to block signal transduction between HBE cells and macrophages inhibited the IL-6/STAT3 pathway. M2 macrophage polarization was inhibited, and MMP9/12 release was reduced.

Conclusion

Our results indicate that CS decreased let-7c expression in HBE cells, and M2 AM polarization was dominant in COPD. In HBE cells, let-7c could inhibit M2 polarization of AMs through the IL-6/STAT3 pathway, providing potential diagnostic and therapeutic value for slowing COPD emphysema.

Network Pharmacology and Experimental Validation to Reveal Effects and Mechanisms of Icariin Combined with Nobiletin against Chronic Obstructive Pulmonary Diseases

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a long-term respiratory disorder marked by restricted airflow and persistent respiratory symptoms. According to previous studies, icariin combined with nobiletin (I&N) significantly ameliorates COPD, but the therapeutic mechanisms remain unclear.

PURPOSE

The aim of the study is to investigate the therapeutic mechanisms of I&N against COPD using network pharmacology and experimental validation.

METHODS

The targets of I&N and related genes of COPD were screened and their intersection was selected. Next, the protein-protein interaction (PPI) networks, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. Further, a COPD rat model was established to validate the effect and mechanisms of I&N.

RESULTS

445 potential targets I&N were obtained from SwissTargetPrediction, STITCH 5.0, and PharmMapper databases. 1831 related genes of COPD were obtained from GeneCards, DrugBank, and DisGeNet databases. 189 related genes were screened via matching COPD targets with I&N. 16 highest score targets among 189 targets were obtained according to PPI networks. GO and KEGG pathway enrichment analyses of 16 highest score targets suggested that these key genes of I&N were mostly enriched in the tumor necrosis factor (TNF) pathway, mitogen-activated protein kinase (MAPK) pathway, and phosphatidyl inositol 3-kinase (PI3K)-protein kinase B (AKT) pathway. Therefore, the treatments of I&N for COPD were connected with inflammation-related pathways. In in vivo experiments, the studies indicated that I&N improved the lung function and alleviated the damage of pulmonary histopathology. Moreover, I&N reduced levels of interleukin (IL)-6, IL-1β, and TNF-α in lung tissues of COPD rats and inhibited the activation of the MAPK pathway and PI3K-Akt pathway.

CONCLUSIONS

Icariin combined with nobiletin has therapeutic effects on COPD by inhibiting inflammation. The potential mechanisms of I&N may relate to the MAPK pathway and PI3K-Akt pathway.

Effective-Component Compatibility of Bufei Yishen Formula III Combined with Electroacupuncture Suppresses Inflammatory Response in Rats with Chronic Obstructive Pulmonary Disease via Regulating SIRT1/NF-κB Signaling

Objective

To explore more efficient treatments for chronic obstructive pulmonary disease (COPD), effective-component compatibility of Bufei Yishen formula III (ECC-BYF III) and electroacupuncture were tested on rats with COPD, and silent information regulator transcript-1 (SIRT1)/nuclear factor-kappaB (NF-κB) signaling was further investigated to interpret the therapy.

Methods

In total, 70 rats were randomly divided into control (Control), model (Model), aminophylline (APL), ECC-BYF III, electroacupuncture (EA), ECC-BYF III+EA, and sham electroacupuncture (SA) groups. Cigarette smoke exposure combined with repeated bacterial infections was used to establish COPD models in 1-12 weeks. From 13 to 20 weeks, the ECC-BYF III and APL groups received corresponding drugs; the EA group received electroacupuncture therapy, wherein Dazhui (GV 14), Feishu (BL 13), and Shenshu (BL 23) points were selected; the ECC-BYF III+EA group received ECC-BYF III intragastrically combined with electroacupuncture; and the SA group received simulated electroacupuncture (nonacupoint). Pulmonary function, pulmonary histopathology, the expressions of SIRT1/NF-κB signaling, and inflammation-related mRNA and protein were detected.

Results

Significant deterioration was observed in pulmonary function and pulmonary histopathology in rats with COPD (P < 0.01), and inflammatory state was illustrated by increased levels of interleukin- (IL-) 6 and tumor necrosis factor alpha (TNF-α) and decreased levels of IL-10 (P < 0.01). After the intervention of APL, ECC-BYF III, EA, and ECC-BYF III+EA, both pulmonary function and pulmonary histopathology were improved (P < 0.05 and P < 0.01), whereas the levels of IL-6 and TNF-α were decreased and IL-10 was increased (P < 0.05 and P < 0.01). Additionally, the mRNA expressions of IL-6, TNF-α, NF-κB, and acetylated NF-κBp65 (Ac-NF-κB) were noted to decrease, and SIRT1 and IL-10 were increased (P < 0.05 and P < 0.01); the protein expression of SIRT1 was upregulated, and NF-κBp65 and Ac-NF-κB were downregulated (P < 0.05 and P < 0.01). The effect of ECC-BYF III+EA was better in terms of improving pulmonary function and alleviating inflammation than that of the other treatment groups (P < 0.01 and P < 0.05).

Conclusions

ECC-BYF III, electroacupuncture, and their combination can suppress inflammation, among which the combination therapy has been proven to be the most effective treatment, and the mechanism may be involved in activating SIRT1/NF-κB signaling.