Experimental Lung Research最新文献

Idiopathic pulmonary fibrosis (IPF) is a progressive fatal disease. Current clinically approved treatments slow disease progression but are not curative. Thus, there is a critical need to better define the pathogenic mechanisms of IPF and develop novel approaches to treat this devastating lung condition. Immune dysregulation of both the innate and adaptive immune systems, accompanied by fibrosis, constitutes a key hallmark of IPF. IPF is generally considered to be a fibroproliferative disorder rather than an immune condition because, historically, immunomodulatory therapies have failed to produce significant clinical effect. This lack of response is frustrating given that there is evidence of immune dysfunction in IPF and highlights the need to clarify the role of immune cells and inflammatory pathways in IPF. There is increasing evidence that the extracellular matrix (ECM) directs cell fate and function, and we propose that ECM remodeling and immune dysfunction in IPF generate a self-perpetuating fibrotic circuit that is refractory to classical anti-inflammatory agents. Understanding the relationship between ECM and immune dysfunction in IPF pathogenesis could help identify novel therapeutic approaches for this devastating disease.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are associated with significant morbidity and mortality rates. Mesenchymal stem cells (MSCs) derived from nasal mucosa, known as EMSCs, have demonstrated therapeutic potential in conditions such as liver failure and bone defects. However, investigations focusing on the application of EMSCs in ALI are still lacking. In our study, an ALI model was induced in rats through lipopolysaccharide (LPS) administration, with subsequent intravenous delivery of either saline or EMSCs. Co-culture experiments using transwell systems revealed that EMSCs improved the viability and proliferation of A549 cells, while also suppressing LPS-induced inflammation and apoptosis. Moreover, the administration of EMSCs not only improved pulmonary microvascular permeability and alleviated histopathological damage, but also exerted downregulatory effects on the levels of pro-inflammatory cytokines, including TNFα, IL6, and IL-1β, while concurrently upregulating the expression of anti-inflammatory cytokine IL-10 in both bronchoalveolar lavage fluid (BALF) and plasma. Immunohistochemistry analysis further revealed an elevated expression of proliferation marker Ki67 and anti-apoptotic protein Bcl2, accompanied by a reduction in the expression of pro-apoptotic protein Bax, thus indicating the beneficial outcomes of EMSCs. Collectively, these findings underscore the potential of EMSC-based therapies as promising and effective strategies for the treatment of lung injury.

Background: Asthma, the most common chronic respiratory disorder affecting individuals of all ages, is driven by inflammation that leads to airway hyperresponsiveness, airway wall remodeling, and mucus production. While inhaled corticosteroids remain the primary treatment despite their limitations, further research into the molecular mechanisms of asthma is needed to identify new therapeutic targets. Methods: A mouse model of asthma was created by treating mice with OVA. HE and PAS staining were used to detect histopathology. Gene and protein expression levels were assessed using qPCR, Western blot, and ELISA. The relationship between USP4 and SRC-1 was examined using Co-IP assay. The ubiquitination levels of SRC-1 were detected using IP assay while macrophage polarization was analyzed by flow cytometry. Results: The ovalbumin-induced mouse model of asthma exhibited a large quantity of inflammatory cell infiltration, proliferation of goblet cells, and increased mucus secretion. SRC-1 expression was upregulated in an OVA-induced mouse model of asthma. Downregulation of SRC-1 reduced macrophage polarization to the M1 phenotype, protecting against OVA-induced asthma, whereas SRC-1 overexpression inhibited M2 macrophage polarization by suppressing the NF-kB signaling pathway. Furthermore, USP4 was found to deubiquitinate SRC-1, enhancing its protein stability. The regulatory axis between USP4 and SRC-1 was validated in vivo. Conclusion: This study demonstrates that USP4 regulates the deubiquitination of SRC-1, which inhibits M2 macrophage polarization and reduces asthma-related inflammation. These findings suggest that USP4 and SRC-1 may serve as potential therapeutic targets for asthma treatment.HighlightsSRC-1 is upregulated in OVA-induced asthma and correlated to macrophage.SRC-1 knockdown reduces M1 macrophage polarization and airway inflammation in the asthma model.SRC-1 overexpression or USP4 overexpression suppresses IL-4-induced M2 polarization via the NF-κB pathway.USP4 regulates the deubiquitination of SRC-1, influencing macrophage polarization and inflammation.

Objective: We aimed to investigate the role and mechanisms of chemokine receptor 1 (CCR1) in airway inflammation in chronic obstructive pulmonary disease (COPD) mice.

Methods: We established a mouse model of cigarette smoke-induced COPD. A mouse model with CCR1 overexpression or silencing COPD was established by tail vein injection of CCR1 overexpression lentivirus or shRNA-CCR1 lentivirus. Pathological changes in the bronchial mucosa were assessed using hematoxylin and eosin (HE) staining. CCR1 expression and cell apoptosis were detected via immunofluorescence and TUNEL. The levels of chemokine (MIP-1β) and inflammatory factors (IL-6 and TNF-α) in bronchoalveolar lavage fluid were detected using enzyme-linked immunosorbent assay (ELISA). The expression levels of the factors in the CCR1 downstream pathway were detected via RT-qPCR and western blotting.

Results: Compared with the COPD mice, the bronchial mucosa of the COPD model mice transfected with the vector showed apoptosis, inflammatory cell infiltration, airway remodeling, and emphysema. The COPD model mice exhibited significantly increased expression levels of p-IKK, p-JAK2, STAT3, and p-p65 and chemokine concentrations (MIP-1β, IL-6 and TNF-α) than the control mice (p < 0.05), which were further aggravated by overexpressed-CCR1 lentiviral transfection but inhibited by shRNA-CCR1 lentiviral transfection or BX471 pretreatment (p < 0.05).

Conclusion: CCR1 aggravates the progression of COPD mice by activating JAK/STAT3/NF-κB signaling. This study has the potential to provide theoretical evidence for the diagnosis and therapeutic strategies of cigarette smoke-induced inflammation in COPD patients.

Aim/Purpose of the study: Acute lung injury (ALI) is a severe respiratory disease with high mortality, mainly due to overactivated oxidative stress and subsequent pyroptosis. Mesencephalic astrocyte-derived neurotrophic factor (MANF), an inducible secretory endoplasmic reticulum (ER) stress protein, inhibits lipopolysaccharide (LPS)-induced acute lung injury (ALI). However, the exact molecular mechanism remains unclear. Peroxiredoxin 6 (PRDX6), a peroxidase with a dual enzymatic function, is essential in regulating oxidative stress, which is closely associated with ALI. Furthermore, PRDX6 is an interacting protein of MANF. Therefore, this study aims to investigate the role of PRDX6 in the protective effect of MANF on ALI.

Materials and Methods: In this study, we used LPS to establish the LPS-induced ALI model. Recombinant human MANF was administrated to wide-type (WT) and PRDX6 knockout (PRDX6^-/-) rats.

Results: In WT rats, MANF reversed the increases of PRDX6, ROS overgeneration, and pyroptosis-related protein-Gasdermin D (GSDMD) induced by LPS challenge. In PRDX6^-/- rats, ROS generation, the protein level of GSDMD-N, and lung injury were not significantly decreased after human recombinant MANF administration in LPS-induced ALI.

Conclusions: PRDX6 is involved in the protective role of MANF on ALI. It is a key target molecule for MANF to exert ALI inhibitory effects.

Aim of the study: Phenotype modulation of airway smooth muscle cells (ASMC), characterized by a shift toward a more proliferative and synthetic phenotype from contractile cells, plays a crucial role in airway remodeling in asthma. STIM1 and Orai1, key components of store-operated Ca²⁺ entry (SOCE), have been demonstrated to enhance ASMC proliferation and migration. This study investigated the impact of STIM1/Orai1-mediated SOCE on ASMC phenotype transition and extracellular matrix (ECM) deposition in asthma.

Materials and methods: The ASMCs were treated with PDGF-BB and SOCE inhibitors. Immunocytochemistry staining, enzyme-linked immunosorbent assay, and western blot assay were employed to detect the ASMC's proliferation as well as the expressions of contractile proteins, inflammatory cytokines and ECM. Moreover, the effect of SOCE repression in ECM deposition were evaluated in an asthmatic mouse model.

Results: ASMCs from airways of mice were treated with PDGF-BB to induce the 'proliferative/synthetic' phenotype. We observed elevated expressions of STIM1 and Orai1 in phenotype-switched ASMCs, along with enhanced SOCE. SKF-96365 and RO2959, which target of STIM1/Orai1, could significantly inhibit SOCE activation in ASMCs. Moreover, these SOCE inhibitors mitigated the elevated proliferation rate, decreased the secretion of inflammatory cytokines and restored the reduced levels of contractile proteins in phenotype-switched ASMCs induced by PDGF-BB. Furthermore, we observed that PDGF-BB-induced 'proliferative/synthetic' ASMCs exhibited increased production of ECM components, including collagen I and fibronectin, as well as metalloproteinases (MMPs) such as MMP2 and MMP9, all of which were effectively inhibited by SKF-96365 and RO2959. In vivo experiments also demonstrated that SOCE inhibitors decreased ECM deposition and MMPs production in the asthmatic mouse model.

Conclusions: These findings underscored the significant role of STIM1/Orai1-mediated SOCE in ASMC phenotype modulation and its impact on the excessive ECM deposition driven by ASMCs. Thus, our findings suggest that STIM1/Orai1-mediated SOCE may contribute to airway remodeling in asthma.

Aim: Artificial Stone Dust (ASD) exposure has been identified as a significant health risk for workers, leading to oxidative stress, inflammatory responses, and potential systemic autoimmune diseases due to its high crystalline silica content. The aim of this study is to identify the impact of ASD on the permeability of alveolar epithelial cells and the mechanisms underlying particle translocation across the alveolar membrane remain unexplored. Methods: The acute toxicological effects of ASD on human bronchial submucosal gland cells CALU-3 cells in vitro were investigated to assess its impact on epithelial barrier integrity, in comparison to crystalline silica particles (Min-U-Sil^®5). Results: Exposure to ASD increased oxidative stress, evidenced by heightened Reactive Oxygen Species (ROS) levels and Heme Oxygenase-1 (HO-1) gene expression in CALU-3 cells, exceeding effects observed with Min-U-Sil^®5. Notably, ASD exposure resulted in a significant decrease in Transepithelial Electrical Resistance (TEER), indicating compromised epithelial barrier integrity, especially at higher concentrations (3.7 mg,18.5 mg and 37 mg) after 24, 48 and 72 h. These findings were not paralleled by a decrease in cell viability, underscoring a specific effect on cellular barrier function rather than cytotoxicity. Conclusions: Our study reveals that ASD induces oxidative stress and disrupts epithelial barrier integrity in vitro, potentially contributing to systemic translocation of particles and subsequent health effects. These findings underscore the need for a rigorous protective measure for workers and highlight potential biomarkers of ASD-induced cellular damage.