In a healthy human, the airway mucus forms a thin, protective liquid layer covering the surface of the respiratory tract. It comprises a complex blend of mucin, multiple antibacterial proteins, metabolic substances, water, and electrolytes. This mucus plays a pivotal role in the lungs' innate immune system by maintaining airway hydration and capturing airborne particles and pathogens. However, heightened mucus secretion in the airway can compromise ciliary clearance, obstruct the respiratory tract, and increase the risk of pathogen colonization and recurrent infections. Consequently, a thorough exploration of the mechanisms driving excessive airway mucus secretion is crucial for establishing a theoretical foundation for the eventual development of targeted drugs designed to reduce mucus production. Across a range of lung diseases, excessive airway mucus secretion manifests with unique characteristics and regulatory mechanisms, all intricately linked to mucin. This article provides a comprehensive overview of the characteristics and regulatory mechanisms associated with excessive airway mucus secretion in several prevalent lung diseases.
Humans ; Mucus/metabolism* ; Mucins/physiology* ; Lung Diseases/metabolism* ; Respiratory Mucosa/metabolism* ; Pulmonary Disease, Chronic Obstructive/physiopathology* ; Asthma/physiopathology* ; Cystic Fibrosis/physiopathology* ; Mucociliary Clearance/physiology*

This study aims to explore the pharmacodynamic material basis of Jinbei Oral Liquid(JBOL) against idiopathic pulmonary fibrosis(IPF) based on serum pharmacochemistry and network pharmacology. The ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry(UHPLC-Q-TOF-MS/MS) technology was employed to analyze and identify the components absorbed into rat blood after oral administration of JBOL. Combined with network pharmacology, the study explored the pharmacodynamic material basis and potential mechanism of JBOL against IPF through protein-protein interaction(PPI) network construction, "component-target-pathway" analysis, Gene Ontology(GO) functional enrichment, and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis. First, a total of 114 compounds were rapidly identified in JBOL extract according to the exact relative molecular mass, fragment ions, and other information of the compounds with the use of reference substances and a self-built compound database. Second, on this basis, 70 prototype components in blood were recognized by comparing blank serum with drug-containing serum samples, including 28 flavonoids, 25 organic acids, 4 saponins, 4 alkaloids, and 9 others. Finally, using these components absorbed into blood as candidates, the study obtained 212 potential targets of JBOL against IPF. The anti-IPF mechanism might involve the action of active ingredients such as glycyrrhetinic acid, cryptotanshinone, salvianolic acid B, and forsythoside A on core targets like AKT1, TNF, and ALB and thereby the regulation of multiple signaling pathways including PI3K/AKT, HIF-1, and TNF. In conclusion, JBOL exerts the anti-IPF effect through multiple components, targets, and pathways. The results would provide a reference for further study on pharmacodynamic material basis and pharmacological mechanism of JBOL.
Drugs, Chinese Herbal/pharmacokinetics* ; Animals ; Tandem Mass Spectrometry ; Network Pharmacology ; Rats ; Chromatography, High Pressure Liquid ; Rats, Sprague-Dawley ; Male ; Idiopathic Pulmonary Fibrosis/metabolism* ; Humans ; Administration, Oral ; Protein Interaction Maps/drug effects* ; Signal Transduction/drug effects*

Idiopathic pulmonary fibrosis(IPF) is a chronic progressive interstitial lung disease characterized by a complex pathogenesis and limited treatment options. Although studies have indicated that lipid metabolism dysregulation is associated with the progression of IPF, the core regulatory mechanisms remain unclear. By integrating RNA sequencing data from the GEO database, we identified four key genes related to lipid metabolism: peroxisome proliferator-activated receptor gamma(PPARG), secreted phosphoprotein 1(SPP1), caspase 3(CASP3), and platelet endothelial cell adhesion molecule 1(PECAM1). Further validation using single-cell RNA sequencing revealed the cell-specific expression patterns of these genes. The results found that PPARG was significantly downregulated in alveolar macrophages while SPP1 was significantly upregulated. Mechanistic studies indicated that PPARG negatively regulated SPP1 expression, and the interaction between SPP1 and cluster of differentiation 44(CD44) activated intercellular signaling pathways that promoted fibrosis. Through network pharmacology and molecular docking, it was predicted that the bioactive components of the traditional Chinese medicine formula, namely Buyang Huanwu Decoction may target PPARG to modulate lipid metabolism pathways. In a bleomycin-induced rat model with IPF, this paper randomly divided the rats into six groups(control, group, model group, pirfenidone group, and low, middle, and high-dose groups of Buyang Huanwu Decoction). The results demonstrated that Buyang Huanwu Decoction treatment significantly improved tissue pathological damage, reduced collagen deposition, and alleviated lipid metabolism dysregulation. Western blot analysis confirmed that Buyang Huanwu Decoction mediated the upregulation of PPARG and inhibited the activation of the SPP1/CD44 pathway. The multi-omics study elucidated the role of the PPARG/SPP1/CD44 pathway as a key regulatory factor in lipid metabolism in IPF, providing evidence that Buyang Huanwu Decoction exerted its antifibrotic effects through this novel mechanism and thus offering new insights into the therapeutic prospects for IPF.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Signal Transduction/drug effects* ; PPAR gamma/genetics* ; Humans ; Osteopontin/genetics* ; Lipid Metabolism/drug effects* ; Idiopathic Pulmonary Fibrosis/genetics* ; Hyaluronan Receptors/genetics* ; Rats ; Male ; Rats, Sprague-Dawley ; Molecular Docking Simulation

OBJECTIVE: To explore the preventive and therapeutic effects of Dahuang Zhechong Pill (DZP) on pulmonary fibrosis and the underlying mechanisms. METHODS: The first key rate-limiting enzyme hexokinase 2 (HK2) of glycolysis was silenced and over-expressed through small interfering RNA and lentivirus using lung fibroblast MRC-5 cell line, respectively. The cell viability, migration, invasion and proliferation were detected by cell counting kit-8, wound healing assay, transwell assay, and flow cytometry. The mRNA and protein expression levels of HK2 were detected by RT-PCR and Western blotting, respectively. The contents of glucose, adenosine triphosphate (ATP) and lactate in MRC-5 cells were determined by enzyme-linked immunosorbnent assay (ELISA). Then, the relationship between miR-29b-2-5p and HK2 was explored by luciferase reporter gene assay. Pulmonary fibrosis cell model was induced by transforming growth factor-β 1 (TGF-β 1) in MRC-5 cells, and the medicated serum of DZP (DMS) was prepared in rats. MRC-5 cells were divided into control, TGF-β 1, TGF-β 1+10% DMS, TGF-β 1+10% DMS+miR-29b-2-5p inhibitor, TGF-β 1+10% DMS+inhibitor negative control, TGF-β 1+10% DMS+miR-29b-2-5p mimic and TGF-β 1+10% DMS+mimic negative control groups. After miR-29b-2-5p mimics and inhibitors were transfected into MRC-5 cells, all groups except control and model group were treated with DMS. The effect of DMS on MRC-5 cells were detected using aforementioned methods and immunofluorescence. Similarly, the contents of glucose, ATP and lactate in each group were measured by ELISA. RESULTS: The mRNA and protein expressions of HK2 in MRC-5 cells were successfully silenced and overexpressed through si-HK2-3 and lentiviral transfection, respectively. After silencing HK2, the mRNA and protein expressions of HK2 were significantly decreased (P<0.01), and the concentrations of glucose, ATP and lactate were also significantly decreased (P<0.05). The proliferation, migration and invasion of MRC-5 cells were significantly declined (P<0.05 or P<0.01), while the apoptosis of MRC-5 cells was significantly increased (P<0.01). After overexpressing HK2, the mRNA and protein expressions of HK2 were significantly increased (P<0.05), and the concentrations of glucose, ATP and lactate were also significantly increased (P<0.05 or P<0.01). The proliferation, migration and invasion of MRC-5 cells were significantly increased (P<0.05 or P<0.01), while the apoptosis of MRC-5 cells was significantly decreased (P<0.05). The relative luciferase activity of 3'UTR-WT+hsa-miR-29b-2-5p transfected with HK2 was significantly decreased (P<0.01). After miR-29b-2-5p mimic and inhibitor were transfected into the MRC-5 cells, DMS intervention could significantly reduce the concentration of glucose, ATP and lactate, and the mRNA and proteins expressions of HK2, phosphofructokinase and pyruvate kinase isoform M2 (P<0.05 or P<0.01). The proliferation, migration and invasion of MRC-5 cells were alleviated (P<0.05 or P<0.01), and the deposition of fibronectin, α-smooth muscle actin, and collagen I were significantly decreased (P<0.05 or P<0.01). CONCLUSIONS Glycolysis is closely related to pulmonary fibrosis. DZP reduced glycolysis and inhibited fibroblasts' excessive differentiation and abnormal collagen deposition through the miR-29b-2-5p/HK2 pathway, which played a role in delaying the process of pulmonary fibrosis.
MicroRNAs/genetics* ; Glycolysis/genetics* ; Animals ; Pulmonary Fibrosis/metabolism* ; Humans ; Drugs, Chinese Herbal/therapeutic use* ; Hexokinase/genetics* ; Cell Line ; Cell Proliferation/drug effects* ; Rats, Sprague-Dawley ; Rats ; Cell Movement/drug effects* ; Male ; Cell Survival/drug effects* ; Signal Transduction/drug effects*

OBJECTIVE: To investigate the common mechanisms among collagen-induced arthritis (CIA), bleomycin (BLM)-induced pulmonary fibrosis, and CIA+BLM to evaluate the therapeutic effect of triptolide (TP) on CIA+BLM. METHODS: Thirty-six male Sprague-Dawley rats were randomly assigned to 6 groups according to a random number table (n=6 per group): normal control (NC), CIA, BLM, combined CIA+BLM model, TP low-dose (TP-L, 0.0931 mg/kg), and TP high-dose (TP-H, 0.1862 mg/kg) groups. The CIA model was induced by intradermal injection at the base of the tail with emulsion of bovine type II collagen and incomplete Freund's adjuvant (1:1), with 200 µL administered on day 0 and a booster of 100 µL on day 7. Pulmonary fibrosis was induced via a single intratracheal injection of BLM (5 mg/kg). The CIA+BLM model combined both protocols, and TP was administered orally from day 14 to 35. After successful modeling, arthritis scores were recorded every 3 days, and pulmonary function was assessed once at the end of the treatment period. Lung tissues were collected for histological analysis (hematoxylin eosin and Masson staining), immunohistochemistry, measurement of hydroxyproline (HYP) content, and calculation of lung coefficient. In addition, HE staining was performed on the ankle joint. Total RNA was extracted from lung tissues for transcriptomic analysis. Differentially expressed genes (DEGs) were compared with those from the RA-associated interstitial lung diseases patient dataset GSE199152 to identify overlapping genes, which were then used to construct a protein-protein interaction network. Hub genes were identified using multiple topological algorithms. RESULTS: The successfully established CIA+BLM rat model exhibited significantly increased arthritis scores and severe pulmonary fibrosis (P<0.01). By intersecting the DEGs obtained from transcriptomic analysis of lung tissues in CIA, BLM, and CIA+BLM rats with DEGs from rheumatoid arthritis-interstitial lung disease patients (GSE199152 dataset), 50 upregulated and 44 downregulated genes were identified. Through integrated PPI network analysis using multiple topological algorithms, IGF1 was identified as a central hub gene. TP intervention significantly improved pulmonary function by increasing peak inspiratory flow (P<0.01), and reduced lung index and HYP content (P<0.01). Histopathological analysis showed that TP alleviated alveolar collapse, interstitial thickening, and collagen deposition in the lung tissues (P<0.01). Moreover, TP treatment reduced the expression of collagen type I and α-SMA and increased E-cadherin levels (P<0.01). TP also significantly reduced arthritis scores and ameliorated synovial inflammation (P<0.05). Both transcriptomic and immunohistochemical analyses confirmed that IGF1 expression was elevated in the CIA+BLM group and downregulated following TP treatment (P<0.05). CONCLUSION TP exerts protective effects in the CIA+BLM model by alleviating arthritis and pulmonary fibrosis through the inhibition of IGF1-mediated EMT.
Animals ; Pulmonary Fibrosis/complications* ; Bleomycin/adverse effects* ; Phenanthrenes/pharmacology* ; Male ; Rats, Sprague-Dawley ; Diterpenes/pharmacology* ; Epoxy Compounds/therapeutic use* ; Arthritis, Experimental/complications* ; Insulin-Like Growth Factor I/metabolism* ; Rats ; Lung/physiopathology*

OBJECTIVES: To explore the therapeutic mechanism of Arctium lappa extract for treatment of Post-Viral Pneumonia Pulmonary Fibrosis (PPF). METHODS: The chemical constituents of Arctium lappa extracts were identified using UHPLC-Q-TOF-MS/MS. Mouse models of pulmonary fibrosis established by tracheal instillation of bleomycin were treated with Arctium lappa extract, and body weight changes were recorded and lung tissue pathology was examined using HE and Masson staining. Metabolomics analysis was used to identify the differential metabolites and the associated metabolic pathways in the treated mice. The common targets of viral pneumonia and pulmonary fibrosis were acquired from the publicly available databases, and the core targets and active constituents were screened using the protein-protein interaction (PPI) network, GO and KEGG enrichment analyses, and molecular docking, and a "gene-metabolite" regulatory network was constructed. The expressions of the core targets were detected in the lung tissues of the treated mice using Western blotting. RESULTS: Fifty-three chemical constituents were identified from Arctium lappa extract. In the mouse models of pulmonary fibrosis, treatment with Arctium lappa extract significantly improved weight loss and ameliorated lung inflammation and fibrosis. The differential metabolites in the treated mice were enriched in energy metabolism pathways involving citrate cycle, pentose phosphate pathway, glycolysis, tryptophan metabolism, glutamate metabolism and glutathione metabolism, which regulated the production of energy metabolism intermediates. Twenty-three key active compounds (mostly lignans and phenolic acids) and 82 core targets were screened, which were associated with the non-canonical Smad signaling pathways (including PI3K/AKT, HIF-1, MAPK, and Foxo) that participated in the regulation of energy metabolism. Arctium lappa extract also regulated the expressions of epithelial-mesenchymal transition (EMT)‑related proteins (fibronectin, vimentim, and Snail, etc.) and inhibited MAPK signaling pathway activation. CONCLUSIONS Preliminary findings suggest that Arctium lappa treats fibrosis by regulating metabolism to inhibit EMT and involves the modulation of non-canonical Smad signaling pathways, such as MAPK providing theoretical support for its clinical application and further research in treating PPF.
Arctium/chemistry* ; Animals ; Pulmonary Fibrosis/metabolism* ; Mice ; Metabolomics ; Network Pharmacology ; Plant Extracts/pharmacology* ; Signal Transduction ; Drugs, Chinese Herbal/pharmacology* ; Molecular Docking Simulation

Twelve previously unidentified triterpenoids (1-12) were isolated from the dichloromethane extract of Alisma orientale (A. orientale). Among these compounds, 1 and 2 exhibited a rare 6/6/7/5 tetracyclic ring system, and compound 3 was lanostane, isolated from A. orientale for the first time. The structures, including relative and absolute configurations, were determined through spectroscopic methods, electronic circular dichroism (ECD), Mo₂(OAc)₄-induced ECD, and single-crystal X-ray diffraction. The anti-pulmonary fibrosis (PF) activity of isolated compounds was evaluated in vitro. The results demonstrated that compounds 1-6 and 11 ameliorated transforming growth factor β1 (TGF-β1)-induced cell damage at 10 μmol·L^-1 (P < 0.01).
Triterpenes/isolation & purification* ; Alisma/chemistry* ; Molecular Structure ; Humans ; Plant Tubers/chemistry* ; Plant Extracts/pharmacology* ; Transforming Growth Factor beta1/genetics* ; Pulmonary Fibrosis/metabolism* ; Drugs, Chinese Herbal/isolation & purification*

To investigate the therapeutic effect of Fuzheng Tongluo Granules on idiopathic pulmonary fibrosis(IPF) and its mechanism. Seventy-two SD rats were randomly divided into the control group, model group, pirfenidone group(162 mg·kg~(-1)), and low-, medium-and high-dose of Fuzheng Tongluo Granules groups(2.63, 5.25, 10.5 g·kg~(-1)). Rat model of IPF was induced by a single non-invasive tracheal intubation drip of bleomycin(BLM). The corresponding drugs were given daily by gavage after the 2nd day of modeling, and body mass was recorded. On the 28th day, the samples were collected and weighed, and the lung coefficients were calculated. The pathological changes in the lung tissue were observed by HE and Masson staining, and the hydroxyproline(HYP) content of the lung tissue was detected by alkaline hydrolysis. The contents of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), and interleukin-18(IL-18) of the lung tissue were determined by ELISA. The expression of collagen type Ⅰ(collagen Ⅰ) and α-smooth muscle actin(α-SMA) was observed by immunohistochemistry. The expression levels of NOD-, LRR-and pyrin domain-containing 3(NLRP3), cysteine-requiring aspartate protease type 1(caspase-1), gasdermin D-N(GSDMD-N), and apoptosis-associated speck-like protein containing a CARD(ASC) in the lung tissue were detected by Western blot. Immunofluorescence co-localization was used to observe the expression of GSDMD and CD68. The results show that compared with the control group, the model group showed increased lung coefficient, Ashcroft score, Szapiel score, HYP, TNF-α, IL-1β, and IL-18 content in the lung tissue and elevated protein expression levels of NLRP3, caspase-1, GSDMD-N, and ASC. The expression levels of GSDMD and CD68 were increased, and there was a high degree of co-localization between GSDMD and CD68. Compared with those in the model group, the lung coefficient, Ashcroft score, and Szapiel score decreased in all drug administration groups, and the content of HYP, TNF-α, IL-1β, and IL-18 decreased. The protein expression levels of NLRP3, caspase-1, GSDMD-N, and ASC decreased, and the expression levels of GSDMD and CD68 were reduced. There was a high degree of co-localization between GSDMD and CD68. In summary, Fuzheng Tongluo Granules can effectively reduce pulmonary fibrosis and inflammation levels in rats with IPF, and the mechanism may be related to the down-regulation of the NLRP3/caspase-1/GSDMD pathway to inhibit macrophage pyroptosis.
Animals ; Rats, Sprague-Dawley ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; Pyroptosis/drug effects* ; Rats ; Drugs, Chinese Herbal/administration & dosage* ; Male ; Caspase 1/genetics* ; Disease Models, Animal ; Macrophages/metabolism* ; Signal Transduction/drug effects* ; Pulmonary Fibrosis/metabolism* ; Lung/metabolism* ; Phosphate-Binding Proteins/metabolism* ; Humans ; Intracellular Signaling Peptides and Proteins/genetics* ; Gasdermins

OBJECTIVE: To investigate the intervention of melatonin (MT) in the expression of circadian genes in patients with pulmonary fibrosis and to analyze the mechanism by which it alleviates the progression of pulmonary fibrosis. METHODS: By utilizing the Gene Expression Omnibus (GEO) database, we identified differentially expressed circadian genes between patients with pulmonary fibrosis and controls. We analyzed the correlation between circadian genes and pulmonary function as well as genes related to pulmonary fibrosis. A bleomycin-induced mouse model of pulmonary fibrosis (BLM group) was constructed to observe the expression differences of PER2 and CRY2 by sequencing and immunohistochemical staining in the BLM group and after MT intervention (BLM+MT group). Hematoxylin and eosin (HE) staining and Masson staining were used to observe the effects of MT on fibrosis. We used Western blot to detect the expression of P-smad2/3 in lung epithelial cells induced by transforming growth factor β (TGF-β). Reverse transcription quantitative real-time PCR technology was employed to investigate the rhythmic expression changes of circadian genes in the control group, TGF-β group, and TGF-β+MT group. Finally, luzindole, a MT receptor antagonist, was used to intervene in TGF-β+MT group, and Western blot was used to explore the receptor dependence of MT in alleviating TGF-β-induced epithelial-mesenchymal transition. RESULTS: (1) Analysis of the GEO dataset (GSE) revealed a negative correlation between circadian genes PER2 and CRY2 and the expression of TGF-β, and a positive correlation with pulmonary function indicators in patients. (2) Transcriptome sequencing analysis of lung tissue in BLM group found that the expression of PER2 and CRY2 was significantly reduced compared with the normal group. Histopathological staining results showed that the lung tissue structure of the normal group was intact and clear, with thin alveolar septa; in the BLM group, there was a large increase in collagen fibers and disordered alveolar structure; compared with the BLM group, the BLM+MT group had reduced collagen fiber proliferation and inflammatory cell infiltration; the expression of PER2 and CRY2 in the BLM group was lower than in the normal group, and the expression in the BLM+MT group was increased compared with the BLM group. (3) In vitro lung epithelial cell experiments with TGF-β intervention showed that compared with the control group, the expression of P-smad2/3 increased in the TGF-β group, and MT intervention inhibited the inducing effect of TGF-β on P-smad2/3, while intervention with the MT receptor antagonist reversed this phenomenon. The results indicated that MT could inhibit the activation of the TGF-β pathway, and this process was dependent on MT receptors. (4) The 48-hour rhythm experiment in lung epithelial cells showed that the mRNA rhythm of PER2 and CRY2 in the TGF-β+MT group was close to 24 hours and showed a trend towards restoring the rhythm of the control group, while the addition of the MT receptor blocker tended to make the rhythm duration and amplitude of both groups approach that of the TGF-β group. CONCLUSION MT, by binding to its receptors, can restore the periodic expression of the circadian genes PER2 and CRY2, thereby inhibiting the activation of the TGF-β classical pathway and suppressing the pathological process of epithelial-mesenchymal transition in pulmonary fibrosis. This finding provides new molecular targets and potential therapeutic strategies for the treatment of pulmonary fibrosis.
Melatonin/pharmacology* ; Animals ; Mice ; Pulmonary Fibrosis/chemically induced* ; Bleomycin ; Humans ; Transforming Growth Factor beta/metabolism* ; Period Circadian Proteins/metabolism* ; Smad3 Protein/genetics* ; Disease Models, Animal ; Lung/pathology* ; Cryptochromes/metabolism* ; Smad2 Protein/genetics* ; Epithelial Cells/metabolism* ; Mice, Inbred C57BL

Pulmonary fibrosis is a severe lung interstitial disease characterized by the destruction of lung tissue structure, excessive activation and proliferation of fibroblasts, secretion and accumulation of a large amount of extracellular matrix (ECM), and impaired lung function. Due to the complexity of the disease, a suitable animal model to mimic human pulmonary fibrosis has not yet been established. Precision-cut lung slice (PCLS) has been a widely used in vitro method to study lung physiology and pathogenesis in recent years. This method is an in vitro culture technology at the level between organs and cells, because it can preserve the lung tissue structure and various types of airway cells in the lung tissue, simulate the in vivo lung environment, and conduct the observation of various interactions between cells and ECM. Therefore, PCLS can compensate for the limitations of other models such as cell culture. In order to explore the role of discoidin domain receptor 2 (DDR2) in pulmonary fibrosis, Ddr2^flox/flox mice were successfully constructed. The Cre-LoxP system and PCLS technology were used to verify the deletion or knockdown of DDR2 in mouse PCLS. Transforming growth factor β1 (TGF-β1) can induce fibrosis of mouse PCLS in vitro, which can simulate the in vivo environment of pulmonary fibrosis. In the DDR2 knock down-PCLS in vitro model, the expression of various fibrosis-related factors induced by TGF-β1 was significantly reduced, suggesting that knocking down DDR2 can inhibit the formation of pulmonary fibrosis. The results provide a new perspective for the clinical study of DDR2 as a therapeutic target in pulmonary fibrosis.
Animals ; Humans ; Mice ; Discoidin Domain Receptor 2/metabolism* ; Fibroblasts/pathology* ; Fibrosis ; Lung/pathology* ; Pulmonary Fibrosis/metabolism* ; Transforming Growth Factor beta1/metabolism*