Purpose: Chronic obstructive pulmonary disease (COPD) is a persistent inflammatory disorder characterized by minor airway inflammation and emphysema involving various cell types and cytokines. MicroRNAs (miRNAs) have emerged as critical regulators in the pathogenesis of lung diseases. This study investigates the impact of microRNA-24 (miR-24) on airway inflammatory responses in a rat model of COPD.
Materials and methods: The model was established by combining cigarette smoke exposure and lipopolysaccharide stimulation, and rat lung tissues were transfected with adeno-associated viruses overexpressing miR-24. Pathological changes in the lung were assessed using hematoxylin and eosin staining. Levels of pro-inflammatory cytokines, including tumor necrosis factor-alpha, interleukin-6, and interleukin-8, were measured using enzyme-linked immunosorbent assay. Expression of miR-24 and S100A8 was detected through quantitative reverse transcription PCR, while protein levels of S100A8, Toll-like receptor 4 (TLR4), and myeloid differentiation primary response 88 (MyD88) were assessed using western blotting. Bioinformatics analysis and dual-luciferase reporter assay were performed to determine the relationship between S100A8 and miR-24.
Results: The results demonstrated the downregulation of miR-24 in rats with COPD, and its overexpression resulted in a significant decrease in S1008 mRNA levels. Additionally, the protein level of S100A8 was significantly increased in the lung tissues of COPD rats. The upregulation of miR-24, however, not only inhibited the protein expression of S100A8, TLR4, and MyD88 in lung tissues but also reduced the release of pro-inflammatory cytokines in the plasma and bronchoalveolar lavage fluid, thereby attenuating inflammatory responses and pathological injuries in the lung.
Conclusions: Our data suggest that miR-24 attenuates airway inflammatory responses in COPD by inhibiting the TLR4/MyD88 pathway via targeting S100A8.
Recent advances in cystic fibrosis (CF) treatments have led to improved survival, with life expectancy for Australians living with CF at 57yo. As life expectancy improves, long-term cardiovascular disease risk factors (as for the general population) will become an issue in these patients. We hypothesized that increased leukocyte expression of vasoconstriction and pro-fibrotic mediators may contribute to CF severity in adults with CF. We recruited 13 adult and 24 pediatric healthy controls, and 53 adults and 9 children living with CF. Leukocyte expression/release of endothelin-1 (ET1) and members of the TGF-β/Smad signaling were measured by multifluorescence quantitative confocal microscopy, Western blotting, ELISA, and real-time quantitative polymerase chain reaction. The association between plasma ET1 levels and lung function was assessed. Leukocytes from adults living with CF expressed higher ET1 levels (p = 0.0033), and TGF-β (p = 0.0031); the phosphorylation ratio increased for Smad2/3 (p = 0.0136) but decreased for Smad1/5/8 (p = 0.0007), vs. control subjects. Plasma ET1 levels were significantly increased in adults with CF with FEV1<50% (p = 0.002) vs. controls, and adults with CF with normal lung function. The release of ET1 in adult plasma inversely correlated with CF severity (-0.609, p = 0.046). Our data indicates that upregulated ET1 and TGF-β/Smad signaling in leukocytes may contribute to CF severity, highlighting the need for further investigations into their impact on the clinical outcomes of people living with CF.
Purpose: In this study, we identified differentially expressed genes (DEGs) and signaling pathways to gain insight into the pathogenesis of acute lung injury (ALI). Methods: C57BL/6 mice were intravenously injected with lipopolysaccharide (LPS) to establish a sepsis-induced ALI model. Hematoxylin-eosin (H&E) and enzyme-linked immunosorbent assays (ELISAs) were used to evaluate the model. Whole transcriptome sequencing was performed to identify the expression changes in lncRNAs, circRNAs, miRNAs and mRNAs in lung tissues. The crucial RNAs and the biological function of the target genes were confirmed and annotated based on bioinformatics analysis. Real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was employed to verify the expression levels of key lncRNAs, circRNAs, miRNAs and mRNAs in the lung tissues and human bronchoalveolar lavage (BALF). Results: A total of 3304 (1632 upregulated and 1672 downregulated) differentially expressed mRNAs, 794 (397 up and 397 down) differentially expressed lncRNAs, 89 (58 up and 31 down) differentially expressed circRNAs, and 14 (11 up and 3 down) differentially expressed miRNAs were identified between the control and LPS lung tissues. The lncRNA ceRNA subnetwork and circRNA ceRNA subnetwork were constructed based on the observed interaction and co-expression among the differentially expressed RNAs. An analysis of the protein-protein interaction (PPI) network and hub genes revealed crucial mRNAs for circRNA-Tcf20. The lncRNA-Snhg12, Edn1, Stat1, miR-212-3p and miR-223-3p were upregulated in sepsis ARDS patients. CircRNA-Tcf20, Col1a1, Col1a2 and Flt3 were significantly downregulated in sepsis ARDS patients. The biological function analysis indicated that these genes were enriched in the TNF signaling pathway, Necroptosis signaling pathway and the PI3K-Akt signaling pathway. Conclusions: Our findings suggest that circRNA-Tcf20, miR-212-3p, miR-223-3p, Col1a1, Col1a2 and Flt3 may be new regulatory factors that participate in the pathogenesis of sepsis-related acute lung injury. CircRNA-Tcf20, lncRNA-Snhg12 and all the other RNAs may be potential biomarkers for septic ALI/ARDS.
Purpose: Ischemia-reperfusion injury (IRI) is a major challenge in lung transplantation often causing graft dysfunction and chronic airway illnesses in recipients. To prevent potential transplant related complications, strict guidelines were put in place to choose viable donor lungs with minimal risk of IRI. These regulations deem most of the donor organs unfit for transplant which then are donated for research to understand the mechanisms of health and diseases in human. However, resected organs that are being transported undergo cold ischemia that can negatively affect the tissue architecture and other cellular functions under study. Thus, it is important to assess how cold ischemia time (CIT) affects the physiological mechanism. In this respect, we are interested in studying how CIT affects cellular senescence in normal aging and various pulmonary pathologies. We thus hypothesized that prolonged CIT exhibits cell-type specific changes in lung cellular senescence in mice. Methods: Lung lobes from C57BL/6J (n = 5-8) mice were harvested and stored in UW Belzer cold storage solution for 0, 4-, 9-, 12-, 24-, and 48-h CIT. Lung cellular senescence was determined using fluorescence (C12FdG) assay and co-immunolabelling was performed to identify changes in individual cell types. Results: We found a rapid decline in the overall lung cellular senescence after 4-h of CIT in our study. Co-immunolabelling revealed the endothelial cells to be most affected by cold ischemia, demonstrating significant decrease in the endothelial cell senescence immediately after harvest. Annexin V-PI staining further revealed a prominent increase in the number of necrotic cells at 4-h CIT, thus suggesting that most of the cells undergo cell death within a few hours of cold ischemic injury. Conclusions: We thus concluded that CIT significantly lowers the cellular senescence in lung tissues and must be considered as a confounding factor for mechanistic studies in the future.
Background: Lung ischemia-reperfusion injury (LIRI) is among the complications observed after lung transplantation and is associated with morbidity and mortality. Preconditioning of the donor lung before organ retrieval may improve organ quality after transplantation. We investigated whether preconditioning with metformin (Met) ameliorates LIRI after lung transplantation. Methods: Twenty Lewis rats were randomly divided into the sham, LIRI, and Met groups. The rats in the LIRI and Met groups received saline and Met, respectively, via oral gavage. Subsequently, a donor lung was harvested and kept in cold storage for 8 h. The LIRI and Met groups then underwent left lung transplantation. After 2 h of reperfusion, serum and transplanted lung tissues were examined. Results: The partial pressure of oxygen (PaO2) was greater in the Met group than in the LIRI group. In the Met group, wet-to-dry (W/D) weight ratios, inflammatory factor levels, oxidative stress levels and apoptosis levels were notably decreased. Conclusions: Met protects against ischemia-reperfusion injury after lung transplantation in rats, and its therapeutic effect is associated with its anti-inflammatory, antioxidative, and antiapoptotic properties.
Background: Macrophages constitute the main part of infiltrating immune cells in Malignant pleural mesothelioma (MPM) and abnormally high ratios of M2 macrophages are present in both pleural effusion and tissue samples of MPM patients. Whether MPM cells affect formation of M2 macrophages is poorly understood. In this study, we focused on identification of MPM-cells-derived soluble factors with M2-promoting effects. Methods: Media of malignant pleural mesothelioma cells were collected and soluble factors affecting macrophages were analyzed by mass spectrometry. TGF-β receptor inhibitor SB431542 was used as the entry point to explore the downstream mechanism of action by qRT-PCR, WB and immunofluorescence. Results: The serum-free culture media collected from the human MPM cells Meso1 and Meso2 significantly enhanced expression of the M2 signature molecules including IL-10, TGF-β and CD206 in the human macrophages THP-1, while the culture medium of the human MPM cells H2452 did not show such M2-promoting effects. Analysis of proteins by mass spectrometry and ELISA suggested that Leucine rich α2 glycoprotein 1(LRG1) was a potential candidate. LRG1 time- and dose-dependently increased expression of the M2 signature molecules, confirming its M2-promoting effects. Furthermore, LRG1's M2-promoting effects were reduced by the TGF-β receptor inhibitor SB431542, and LRG1 increased phosphorylation of Smad2, indicating that M2-promoting effects of LRG1 were via the TGF-β receptor/Smad2 signaling pathway. Conclusions: Our results provide a potential M2-promoting new member, LRG1, which contributes to the immune escape of MPM via the TGF-β receptor/Smad2 signaling pathway.
Objective: The aim of this study is to assess the impact of Liver X receptors (LXRs) on airway inflammation, airway remodeling, and lipid deposition induced by cigarette smoke and lipopolysaccharide (LPS) exposure in the lung.
Methods: Wild mice and LXR-deficient mice were exposed to cigarette smoke and LPS to induce airway inflammation and remodeling. In addition, some wild mice received intraperitoneal treatment with the LXR agonist GW3965 before exposure to cigarette smoke and LPS. Lung tissue and bronchoalveolar lavage fluid were collected to evaluate airway inflammation, airway remodeling and lipid deposition.
Results: Exposure to cigarette smoke and LPS resulted in airway inflammation, emphysema and lipid accumulation in wild mice. These mice also exhibited downregulated LXRα and ABCA1 in the lung. Treatment with GW3965 mitigated inflammation, remodeling and lipid deposition, while the deletion of LXRs exacerbated these effects. Furthermore, GW3965 treatment following exposure to cigarette smoke and LPS increased LXRα and ABCA1 expression and attenuated MyD88 expression in wild mice.
Conclusion: LXRs demonstrate the potential to mitigate cigarette smoke and LPS- induced airway inflammation, emphysema and lipid disposition in mice.
Introduction: Bronchopulmonary dysplasia (BPD) impacts life expectancy and long-term quality of life. Currently, BPD mouse models exposed to high oxygen are frequently used, but to reevaluate their relevance to human BPD, we attempted an assessment using micro-computed tomography (µCT).
Methods: Newborn wildtype male mice underwent either 21% or 95% oxygen exposure for 4 days, followed until 8 wk. Weekly µCT scans and lung histological evaluations were performed independently.
Results: Neonatal hyperoxia for 4 days hindered lung development, causing alveolar expansion and simplification. Histologically, during the first postnatal week, the exposed group showed a longer mean linear intercept, enlarged alveolar area, and a decrease in alveolar number, diminishing by week 4. Weekly µCT scans supported these findings, revealing initially lower lung density in newborn mice, increasing with age. However, the high-oxygen group displayed higher lung density initially. This difference diminished over time, with no significant contrast to controls at 3 wk. Although no significant difference in total lung volume was observed at week 1, the high-oxygen group exhibited a decrease by week 2, persisting until 8 wk.
Conclusion: This study highlights µCT-detected changes in mice exposed to high oxygen. BPD mouse models might follow a different recovery trajectory than humans, suggesting the need for further optimization.
Background: Acute respiratory distress syndrome (ARDS) is a respiratory failure syndrome characterized by hypoxemia and changes in the respiratory system. ARDS is the most common cause of death in COVID-19 deaths was ARDS. In this study, we explored the role of miR-223 in exosomes in ARDS.
Methods: Exosomes were purified from the supernatants of macrophages. qPCR was used to detect relative mRNA levels. A luciferase reporter assay was performed to verify the miRNA target genes. Western blotting was used to detect the activation of inflammatory pathways. Flow cytometry was performed to assess apoptosis. An LPS-induced ARDS mouse model was used to assess the function of miR-223 in ARDS.
Results: Exosomes secreted by macrophages promoted apoptosis in A549 cells. Macrophages and exosomes contain high levels of miR-223. Exogenous miR-223 can decrease the expression of insulin-like growth factor 1 receptor (IGF-1R) in A549 and promote the apoptosis of A549.Transfection of anti-miR223 antisense nucleotides effectively reduced the level of miR-223 in macrophages and exosomes and eliminated the pro-apoptotic effect of A549. In vivo, LPS stimulation increased inflammatory cell infiltration in the lungs of mice, whereas knockdown of miR-223 in mice resulted in significantly reduced eosinophil infiltration.
Conclusions: Macrophages can secrete exosomes containing miR-223 and promote apoptosis by targeting the IGF-1R/Akt/mTOR signaling pathway in A549 cells and mouse models, suggesting that miR-223 is a potential target for treating COVID-19 induced ARDS.
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：