Erythromycin reverses cigarette smoke extract-induced corticosteroid insensitivity by inhibition of the JNK/c-Jun pathway

Protective Effect of the Total Alkaloid Extract from Bulbus Fritillariae pallidiflorae in a Mouse Model of Cigarette Smoke-Induced Chronic Obstructive Pulmonary Disease

Purpose

In recent years, the incidence of chronic obstructive pulmonary disease (COPD) has been increasing year by year, but therapeutic drugs has no breakthrough. The total alkaloid extract from Bulbus Fritillariae pallidiflorae (BFP-TA) is widely used in treating lung diseases. Therefore, this study aimed to investigate the protective effect and mechanism of BFP-TA in COPD mice.

Methods

BFP-TA was prepared by macroporous adsorbent resin, and the material basis of BFP-TA was analyzed by HPLC-ELSD and UHPLC-MS/MS. Then, the COPD mouse model was induced by cigarette smoke (CS) for 12 weeks, administered at weeks 9-12. Subsequently, the body weight, lung-body ratio, pulmonary function, histopathology, and the levels of pro-inflammatory cytokines, matrix metalloproteinases (MMPs) and oxidative stress markers in the serum of mice were determined. The expressions of related protein of EMT and MAPK signaling pathways in the lung tissues of mice were detected by Western blot.

Results

The alkaloid relative content of BFP-TA is 64.28%, and nine alkaloids in BFP-TA were identified and quantified by UHPLC-MS/MS. Subsequently, the animal experiment showed that BFP-TA could improve pulmonary function, and alleviate inflammatory cell infiltration, pulmonary emphysema, and collagen fiber deposition in the lung of COPD mice. Furthermore, BFP-TA could decrease the levels of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β), MMPs (MMP-9 and MMP-12) and MDA, while increase the levels of TIMP-1 and SOD. Moreover, BFP-TA could decrease the protein expressions of collagen I, vimentin, α-SMA, MMP-9, MMP-9/TIMP-1, Bax, p-JNK/JNK, p-P38/P38, and p-ERK/ERK, while increase the level of E-cadherin.

Conclusion

This study is the first to demonstrate the protective effect of BFP-TA in CS-induced COPD mouse model. Furthermore, BFP-TA may improve airway remodeling by inhibiting the EMT process and potentially exert anti-inflammatory effect by inhibiting the MAPK signaling pathway.

Lung Fibroblasts from Chronic Obstructive Pulmonary Disease Subjects Have a Deficient Gene Expression Response to Cigarette Smoke Extract Compared to Healthy

Background and aim

Cigarette smoking is the most common cause of chronic obstructive pulmonary disease (COPD) but more mechanistic studies are needed. Cigarette smoke extract (CSE) can elicit a strong response in many COPD-related cell types, but no studies have been performed in lung fibroblasts. Therefore, we aimed to investigate the effect of CSE on gene expression in lung fibroblasts from healthy and COPD subjects.

Patients and methods

Primary lung fibroblasts, derived from six healthy and six COPD subjects (all current or ex-smokers), were either unstimulated (baseline) or stimulated with 30% CSE for 4 h prior to RNA isolation. The mRNA expression levels were measured using the NanoString nCounter Human Fibrosis V2 panel (760 genes). Pathway enrichment was assessed for unique gene ontology terms of healthy and COPD.

Results

At baseline, a difference in the expression of 17 genes was found in healthy and COPD subjects. Differential expression of genes after CSE stimulation resulted in significantly less changes in COPD lung fibroblasts (70 genes) than in healthy (207 genes), with 51 genes changed in both. COPD maintained low NOTCH signaling throughout and upregulated JUN >80%, indicating an increase in apoptosis. Healthy downregulated the Mitogen-activated protein kinase (MAPK) signaling cascade, including a ≥50% reduction in FGF2, CRK, TGFBR1 and MEF2A. Healthy also downregulated KAT6A and genes related to cell proliferation, all together indicating possible cell senescence signaling.

Conclusion

Overall, COPD lung fibroblasts responded to CSE stimulation with a very different and deficient expression profile compared to healthy. Highlighting that stimulated healthy cells are not an appropriate substitute for COPD cells which is important when investigating the mechanisms of COPD.

Quercetin promotes autophagy to alleviate cigarette smoke-related periodontitis

BACKGROUND AND OBJECTIVES

Cigarette smoking has been reported as an independent risk factor for periodontitis. Tobacco toxins affect periodontal tissue not only locally but also systemically, leading to the deterioration and recurrence of periodontitis. However, the mechanism of cigarette smoke-related periodontitis (CSRP) is unclear and thus lacks targeted treatment strategies. Quercetin, a plant-derived polyphenolic flavonoid, has been reported to have therapeutic effects on periodontitis due to its documented antioxidant activity. This study aimed to evaluate the effects of quercetin on CSRP and elucidated the underlying mechanism.

METHODS

The cigarette smoke-related ligature-induced periodontitis mouse model was established by intraperitoneal injection of cigarette smoke extract (CSE) and silk ligation of bilateral maxillary second molars. Quercetin was adopted by gavage as a therapeutic strategy. Micro-computed tomography was used to evaluate the alveolar bone resorption. Immunohistochemistry detected the oxidative stress and autophagy markers in vivo. Cell viability was determined by Cell Counting Kit-8, and oxidative stress levels were tested by 2,7-dichlorodihydrofluorescein diacetate probe and lipid peroxidation malondialdehyde assay kit. Alkaline phosphatase and alizarin red staining were used to determine osteogenic differentiation. Network pharmacology analysis, molecular docking, and western blot were utilized to elucidate the underlying molecular mechanism.

RESULTS

Alveolar bone resorption was exacerbated and oxidative stress products were accumulated during CSE exposure in vivo. Oxidative stress damage induced by CSE caused inhibition of osteogenic differentiation in vitro. Quercetin effectively protected the osteogenic differentiation of human periodontal ligament cells (hPDLCs) and periodontal tissue by upregulating the expression of Beclin-1 thus to promote autophagy and reduce oxidative stress damage.

CONCLUSION

Our results established a role of oxidative stress damage and autophagy dysfunction in the mechanism of CSE-induced destruction of periodontal tissue and hPDLCs, and provided a potential application value of quercetin to ameliorate CSRP.

Herb-symptom analysis of Erchen decoction combined with Xiebai powder formula and its mechanism in the treatment of chronic obstructive pulmonary disease

Background: In recent years, the incidence and mortality rates of chronic obstructive pulmonary disease (COPD) have increased significantly. Erchen Decoction combined with Xiebai Powder (ECXB) formula is mainly used to treat lung diseases in traditional Chinese medicine (TCM). However, the active ingredients of ECXB formula, COPD treatment-related molecular targets, and the mechanisms are still unclear. To reveal its underlying action of mechanism, network pharmacology, molecular docking, and molecular dynamic (MD) simulation approaches were used to predict the active ingredients and potential targets of ECXB formula in treating COPD. As a result, Herb-Symptom analysis showed that the symptoms treated by both TCM and modern medicine of ECXB formula were similar to the symptoms of COPD. Network pharmacology identified 170 active ingredients with 137 targets, and 7,002 COPD targets was obtained. 120 targets were obtained by intersection mapping, among which the core targets include MAPK8, ESR1, TP53, MAPK3, JUN, RELA, MAPK1, and AKT1. Functional enrichment analysis suggested that ECXB formula might exert its treat COPD pharmacological effects in multiple biological processes, such as cell proliferation, apoptosis, inflammatory response, and synaptic connections, and ECXB formula treated COPD of the KEGG potential pathways might be associated with the TNF signaling pathway, cAMP signaling pathway, and VEGF signaling pathway. Molecular docking showed that ECXB formula treatment COPD core active ingredients can bind well to core targets. MD simulations showed that the RELA-beta-sitosterol complex and ESR1-stigmasterol complex exhibited higher conformational stability and lower interaction energy, further confirming the role of ECXB formula in the treatment of COPD through these core components and core targets. Our study analyzed the medication rule of ECXB formula in the treatment of COPD from a new perspective and found that the symptoms treated by both TCM and modern medicine of ECXB formula were similar to the symptoms of COPD. ECXB formula could treat COPD through multi-component, multi-target, and multi-pathway synergistic effects, providing a scientific basis for further study on the mechanism of ECXB formula treatment of COPD. It also provides new ideas for drug development.

Cryptotanshinone Reverses Corticosteroid Insensitivity by Inhibition of Phosphoinositide-3-Kinase-δ in Chronic Obstructive Pulmonary Disease

Purpose

Corticosteroid insensitivity has become a major barrier in the treatment of chronic obstructive pulmonary disease (COPD). It is known that oxidative stress reduces the expression and activity of histone deacetylase (HDAC)-2 by activating phosphoinositide-3-kinase-δ(PI3Kδ)/Akt pathway, which is a common mechanism. The aim of this study was to investigate whether cryptotanshinone (CPT) can improve corticosteroid sensitivity and to investigate the molecular mechanisms by which this occurs.

Patients and Methods

Corticosteroid sensitivity in peripheral blood mononuclear cells (PBMCs) collected from COPD patients, or in human monocytic U937 monocytic cells exposed to cigarette smoke extract (CSE), was quantified as the dexamethasone concentration required to achieve 30% inhibition of tumor necrosis factor-α (TNFα)-induced interleukin 8 (IL-8) production in the presence or absence of cryptotanshinone. PI3K/Akt activity (measured as the relative ratio of phosphorylated Akt at Ser-473 to total Akt) and HDAC2 expression levels were determined by western blotting. HDAC activity was evaluated by a Fluo-Lys HDAC activity assay kit in U937 monocytic cells.

Results

Both PBMCs in patients with COPD and U937 cells exposed to CSE were found to be insensitive to dexamethasone, accompanied by increased phosphorylated Akt (pAkt) and decreased HDAC2 protein expression. The pretreatment of cryptotanshinone restored their sensitivity to dexamethasone, and simultaneously downregulated the level of phosphorylated Akt and upregulated the level of HDAC2 protein. Pretreatment with cryptotanshinone or IC87114 reversed the decrease in HDAC activity in CSE-stimulated U937 cells.

Conclusion

Cryptotanshinone restores corticosteroid sensitivity induced by oxidative stress via inhibition of PI3Kδ and is a potential treatment for corticosteroid-insensitive diseases such as COPD.

Erythromycin attenuates oxidative stress-induced cellular senescence via the PI3K-mTOR signaling pathway in chronic obstructive pulmonary disease

Background and Purpose: Chronic obstructive pulmonary disease (COPD) is proposed to hasten lung aging. Erythromycin protects against oxidative stress and inflammatory responses. However, the potential anti-senescence effect of erythromycin remains disclosed. In the present study, we investigated whether erythromycin influenced oxidative stress-induced cellular senescence and investigated its related mechanisms. Methods: A cigarrete smoke (CS) -induced emphysema mouse model and a H₂O₂-induced premature senescence model in human bronchial epithelial cell line (BEAS-2B) were established. Senescence-related markers (P53, P21 and SA-β-Gal activity), and levels of oxidative stress biomarkers (MDA, SOD and ROS) were measured. Additionally, cells were pretreated with rapamycin (mTOR inhibitor) or erythromycin, and the expression levels of components of the PI3K-mTOR signaling pathway were measured in BEAS-2B cells. Results: Exposed to H₂O₂, increased SA-β-gal activity was observed in BEAS-2B cells suggesting premature senescence. Erythromycin inhibited the expression of P53 and P21 in the CS-induced emphysema mouse model. MDA levels significantly increased and SOD levels decreased in the CS-exposed mice and H₂O₂-induced BEAS-2B cells. Rapamycin and erythromycin significantly suppressed the expression of P53 and P21. Additionally, rapamycin and erythromycin inhibited the PI3K-mTOR signaling pathway. Conclusion: Our findings suggest that erythromycin ameliorates oxidative stress-induced cellular senescence via the PI3K-mTOR signaling pathway. Hence, we establish a theoretical foundation for the clinical application of erythromycin for COPD prevention and treatment.

Effect of erythromycin on the ultrastructure of human macrophages exposed to cigarette smoke extract in vitro

Macrophages serve an active role in the pathophysiology of chronic obstructive pulmonary disease (COPD). Erythromycin (EM) has been verified as an effective treatment for COPD. However, there are few studies on the effect of EM on the ultrastructure of macrophages exposed to cigarette smoke extract (CSE). In the present study, human macrophages were randomly divided into three groups: The control, CSE and the CSE+EM group, using electron microscopy, the effect of EM was evaluated by comparing the ultrastructural changes between these groups. The macrophages were additionally divided into a further four groups: The control, CSE, CSE+EM 24 h and CSE+EM 48 h groups. The generation of reactive oxygen species (ROS) in each group was evaluated by detecting fluorescence intensity. It was observed that the cellular ultrastructure of the CSE group exhibited abnormal changes, though this effect was reversed back to the level of the control in the CSE+EM group. Compared with the control group, the ROS expression level was significantly increased in the CSE group (P < .05); however, compared with the CSE group, the ROS concentration was decreased in the CSE+EM 24 h (P < .05) and CSE+EM 48 h groups (P < .05), though this was more apparent in the EM 48 h group. It was concluded that EM protects human macrophages against CSE. Moreover, it was hypothesized that EM may reduce the symptoms of patients with COPD by protecting the macrophage ultrastructure from the effects of CSE, resulting in the decreased generation of ROS, inhibiting autophagy and reducing endoplasmic reticulum stress.

CpG Oligodeoxynucleotides Attenuate OVA-Induced Allergic Airway Inflammation via Suppressing JNK-Mediated Endoplasmic Reticulum Stress

Purpose

CpG-ODN has been found to attenuate allergic airway inflammation in our previous study. Here, we aimed to further investigate whether CpG-ODN exerts such effect via regulating endoplasmic reticulum (ER) stress and revealed the underlying mechanism.

Methods

Five-week-old C57BL/6 mice were randomly grouped and treated with or without CpG-ODN or/and SP600125. Meantime, RAW264.7 cells were used to investigate the effect of CpG-ODN on OVA-induced ER stress in vitro. The cellularity of bronchoalveolar lavage fluid (BALF) was classified and counted after Wright-Giemsa staining. HE and PAS staining methods were applied to analyze airway inflammation. The protein levels of IL-4, IL-5, IL-13, p-JNK, JNK, CHOP, XBP1, ATF6α and GRP78 in lung tissues were detected by Western blotting. Correspondingly, the ER stress markers were detected by Western blotting and immunofluorescence in RAW264.7 cells.

Results

In OVA-induced allergic airway inflammation, CpG-ODN significantly suppressed inflammatory cells infiltration, goblet cell hyperplasia and the protein expression of Th2 cytokines. Moreover, OVA exposure strongly increased the activation of ER stress with higher protein expressions of CHOP, XBP1, ATF6α and GRP78. However, these OVA-induced increase of ER stress markers were markedly suppressed by CpG-ODN treatment. In addition, exposure to OVA significantly increased the phosphorylation of JNK, which was significantly reduced by CpG-ODN treatment. Remarkably, single treatment of SP600125, an antagonist of JNK, functioned similarly as CpG-ODN in mitigating allergic airway inflammation and suppressing OVA-induced activation of ER stress; however, no significant synergistic effect was evidenced by combined treatment of SP600125 and CpG-ODN. Furthermore, in OVA-stimulated RAW264.7 cells, we also found that OVA stimulation increased the expressions of ER stress markers, and CpG-ODN significantly reduced their expression levels via suppressing the phosphorylation of JNK.

Conclusion

These results indicated that CpG-ODN mitigates allergic airway inflammation via suppressing the activation of JNK-medicated ER stress.

The Inflammatory Response Induced by RELMβ Upregulates IL-8 and IL-1β Expression in Bronchial Epithelial Cells in COPD

Purpose

Chronic obstructive pulmonary disease (COPD) is associated with a complex inflammatory regulatory network. Resistin-like molecule β (RELMβ) is highly expressed in the lungs of COPD patients. We aimed to investigate the proinflammatory effect of RELMβ on airway epithelial cells in COPD.

Methods

First, a GEO dataset was used to analyze the expression of the RELMβ gene in the COPD and control groups as well as the protein levels of RELMβ in the sera of outpatients with COPD and normal control subjects in our hospital. We also stimulated 16HBE bronchial epithelial cells with recombinant RELMβ protein and analyzed the expression of IL-8 and IL-1β. We upregulated and downregulated the gene expression of RELMβ in 16HBE cells and analyzed the expression of the inflammatory cytokines IL-8 and IL-1β. In addition, we also examined the mechanism by which the p38 MAPK signaling pathway contributed to the regulation of IL-8 and IL-1β expression by RELMβ.

Results

RELMβ expression was increased in COPD tissues in different data sets and in the serum of COPD patients in our hospital. IL-8 and IL-1β expression was also increased in COPD tissues with high RELMβ gene expression in different data sets. The RELMβ gene was mainly related to inflammatory factors and inflammatory signaling pathways in the PPI regulatory network. Experiments at the cellular level showed that RELMβ promoted the expression of the inflammatory cytokines IL-8 and IL-1β, and this regulation was mediated by the p38 MAPK signaling pathway.

Conclusion

RELMβ can promote the expression of the inflammatory cytokines IL-8 and IL-1β in bronchial epithelial cells of patients with COPD and exert inflammatory effects. RELMβ may be a potential target for the treatment of COPD.

JNK modulates RAGE/β-catenin signaling and is essential for allergic airway inflammation in asthma

As a leading cause of occupational asthma, toluene diisocyanate (TDI)-induced asthma is an inflammatory disease of the airways with one of the most significant characteristics involving inflammation, in which the receptor of advanced glycation end products (RAGE) plays an extremely important role. However, the mechanism underlying the upregulation of RAGE is still unknown. The aim of the present study was to examine whether JNK mediates β-catenin stabilization via activation of RAGE in asthma. Herein from the results by analyzing the blood from healthy donors and patients with asthma, it was found that the expression of RAGE and p-JNK is highly correlated and elevated concomitantly with the severity of bronchial asthma. Additionally, upon sensitizing and challenging the mice with TDI, we found that RAGE inhibitor (FPS-ZM1) and JNK inhibitor (SP600125) significantly reduced the TDI-induced asthma inflammation in vivo. Furthermore, SP600125 also considerably restored RAGE and p-JNK expression. Besides, the in vitro results from TDI-HSA treatment of 16HBE cells reveal that therapeutic inhibition of JNK reduced TDI driving RAGE expression and β-catenin translocation, while treatment with Anisomycin, a JNK agonist, showed the opposite effect. Moreover, genetic knockdown of RAGE does not contribute to JNK phosphorylation, indicating that JNK functions upstream of RAGE. Collectively, these findings highlight a role for JNK signaling in RAGE/β-catenin regulation and have important therapeutic implications for the treatment of TDI induced asthma.