Objective To investigate the effects of caveolin-1 scaffolding domain peptide ( CSD-p)on expressions of extracellular matrix and Smads in human fetal lung fibroblasts. Methods Human fetal lung fibroblasts were cultured in vitro and divided into four groups. A control group: the cells were cultured in DMEMwithout TGF-β1 or CSD-p. A CSD-p treatment group: the cells were cultured in DMEMcontaining 5 μmol /L CSD-p. A TGF-β1 treatment group: the cells were cultured in DMEMcontaining 5 μg/L TGF-β1 .A TGF-β1 + CSD-p treatment group: the cells were cultured in DMEM containing 5 μg/L TGF-β1 and 5 μmol /L CSD-p. Caveolin -1 mRNA was detected by RT-PCR. Caveolin-1, collagen-Ⅰ, α-SMA, p-Smad2,p-Smad3 and Smad7 proteins were measured by Western blot. Results Compared with the control group,the Caveolin -1 mRNA and protein expressions in the cells of TGF-β1 group significantly reduced ( mRNA:0. 404 ±0. 027 vs. 1. 540 ±0. 262; protein: 0. 278 ±0. 054 vs. 1. 279 ±0. 085; P lt; 0. 01) , and the expression levels of collagen-Ⅰ and α-SMA proteins significantly increased ( collagen-Ⅰ: 1. 127 ±0. 078 vs.0. 234 ±0. 048; α-SMA: 1. 028 ±0. 058 vs. 0. 295 ±0. 024) . Meanwhile, the expression levels of p-Smad2 ( 1. 162 ±0. 049 vs. 0. 277 ±0. 014) and p-Smad3 proteins ( 1. 135 ±0. 057 vs. 0. 261 ±0. 046) increased with statistical significance ( P lt; 0. 01) , but the expression level of Smad7 protein significantly reduced( 0. 379 ±0. 004 vs. 1. 249 ±0. 046, P lt;0. 001) . In the CSD-p group, CSD-p had no significant effects on the expressions of above proteins compared with the control group. But in the TGF-β1 +CSD-p group, the overexpressions of collagen-Ⅰ, α-SMA, p-Smad2 and p-Smad3 induced by TGF-β1 were obviously inhibited by CSD-p ( collagen-Ⅰ: 0. 384 ±0. 040 vs. 1. 127 ±0. 078; α-SMA: 0. 471 ±0. 071 vs. 1. 127 ±0. 078;p-Smad2: 0. 618 ±0. 096 vs. 1. 162 ±0. 049; p-Smad3: 0. 461 ±0. 057 vs. 1. 135 ±0. 057; P lt; 0. 01) .Otherwise, the up-regulation of Smad7 ( 0.924 ±0. 065 vs. 0.379 ±0. 004) was found. Conclusions CSD-p can reduce fibroblast collagen-I and α-SMA protein expressions stimulated by TGF-β1 , possibly through regulation of TGF-β1 /Smads signaling pathway. It is suggested that an increase in caveolin -1 function through the use of CSD-p may be an intervention role in pulmonary fibrosis.
Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic at the end of December 2019, more than 85% of the population in China has been infected. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mainly affects the respiratory system, especially the lungs. The mortality rate of patients with severe infection is high. A percentage of 6% to 10% of patients will eventually develop into COVID-related acute respiratory distress syndrome (CARDS), which requires mechanical ventilation and extracorporeal membrane oxygenation (ECMO) support. Some patients who survive acute lung injury will subsequently develop post COVID-19 pulmonary fibrosis (PCPF). Both fully treated CARDS and severe PCPF are suitable candidates for lung transplantation. Due to the special course, evaluation strategies are different from those used in patients with common end-stage lung disease. After lung transplantation in COVID-19 patients, special treatment is required, including standardized nucleic acid testing for the novel coronavirus, adjustment strategy of immunosuppressive drugs, and rational use of antiviral drugs, which is a big challenge for the postoperative management of lung transplantation. This consensus was evidence-based written and was reached by experts after multiple rounds of discussions, providing reference for assessment and postoperative management of patients with interstitial pneumonia after COVID-19 infection.
Objective To evaluate the effects of two different epidermal growth factor receptor tyrosine kinase inhibitors ( EGFR-TKIs) , Gefitinib and Erlotinib, on lung fibrosis induced by bleomycin.Methods Forty BALB/c female mice were randomly divided into four groups, ie. a control group( saline given orally and intratracheally) , a fibrosis group( saline given orally with bleomycin instillation) , a Gefitnib group( Gefitnib 20 mg/kg given orally with bleomycin instillation) , and an Erlotinib group ( Erlotinib25 mg/kg given orally with bleomycin instillation) . Bleomycin ( 3 mg/kg) was intratracheally instilled on the first day. Gefitinib or Erlotinib was given orally daily and normal saline as control. Then they were sacrificed by abdominal aortic bleeding 14 days after the bleomycin instillation. The left lung was stained with HE and Masson’s trichrome staining respectively for pathological examination. Total EGFR and phosphorylated EGFR were detected by immunohistochemistry. Hydroxyproline ( HYP) assay was performed in the right lung.Results Both Gefitinib and Erlotinib significantly reduced lung collagen accumulation and the content of HYP. Immunohistochemistry revealed that phosphorylation of EGFR in lung mesenchymal cells induced by bleomycin was inhibited. Furthermore, there was no difference between Gefitinib and Erlotinib in inhibiting lung fibrosis. Conclusion Our findings suggest that, in the preclinical setting, EGFR-TKIs may have aprotective effect on lung fibrosis induced by bleomycin.
ObjectiveTo construct a luciferase reporter fusion containing the human connective tissue growth factor (CTGF) gene promoter.MethodsThe promoter region of the human CTGF gene (-835/+214) was amplified by polymerase chain reaction (PCR) using specially-designed primers, and subsequently cloned into the pGL3.0-Basic vector. Following screening and verification by single colony PCR, double digestion, and sequencing, the resulting pGL3.0-Basic-CTGF was used to transfect the human embryonic kidney cells 293T, human bronchial epithelial cells HBE and human lung epithelial cells A549, and its function in each cell line was determined by luciferase assay.ResultsSequence alignment showed 99.5% identity, suggesting successful construction of the pGL3.0-Basic-CTGF reporter fusion. Promoter activities were detected 48 hours after transfection of pGL3.0-Basic-CTGF into the 293T, HBE, and A549 cells, and the promoter activities were 2.416, 0.027, and 0.121, respectively (P<0.01). Moreover, the luciferase activity in the A549 cells was statistically higher than that in the HBE cells (P<0.01).ConclusionsThe human pGL3.0-Basic-CTGF luciferase reporter fusion has been successfully constructed. The construct exhibits promoter activity in the bronchial epithelial cells HBE and the lung epithelial cells A549, and can therefore serve as a useful tool for future research in transcriptional regulation.
ObjectiveTo investigate the effects and mechanism of atorvastatin in the experimental pulmonary fibrosis. MethodsFifty-four C57BL/6 mice were randomly divided into a control group,a bleomycin group and an atorvastatin group. The mice in the bleomycin group and the atorvastatin group received a single dose intratracheal injection of bleomycin (2.5 mg/kg),while the mice in the control group were injected with isodose physiological saline. The mice in the atorvastatin group were treated with atorvastatin 10 mg·kg-1·d-1 by intragastric administration the day after bleomycin instillation. All groups were sacrificed on the day 3,14 and 28,respectively. HE staining and Masson staining were used to detect the architecture of alveolar and the deposition of cellularity and collagen. RT-PCR and immunohistochemical technology were performed to detect the expression of Krüppel like factor 4 (KLF4). Zymography was used to investigate the activation of matrix metalloproteinase-2(MMP-2). ResultsAfter the treatment of bleomycin,the lung tissues showed acute inflammation on the day 3,the collagen deposition was more obvious and the architecture of alveolar was destroyed on the day 14. The alveolar structure,the inflammation and collagen deposition were attenuated on the day 28 compared with the day 14. Compared with the bleomycin group,the inflammation and the collagen deposition were significantly reduced in the atorvastatin group (P<0.05). Compared with bleomycin group,the expression of KLF4 significantly decreased in the atorvastatin group,although the expression of KLF4 mRNA increased on the day 3 compared with the bleomycin group (0.502±0.261 vs. 0.326±0.164,P<0.05). The expression of KLF4 protein on the day 3 was significantly decreased compared with the bleomycin group (0.048±0.015 vs. 0.130±0.017,P<0.05). After the intervention of bleomycin,the activation of MMP-2 on the day 3 and 14 significantly increased compared with the control group (3.136±1.321 and 3.449±0.356 vs. 0.983±0.147,P<0.05),and significantly decreased after the treatment of atorvastatin (2.191±0.800 and 2.506±0.761). ConclusionAtorvastatin may have anti-inflammation and anti-fibrosis activities in experimental pulmonary fibrosis through KLF4 pathway.
ObjectiveAlthough evidence links idiopathic pulmonary fibrosis (IPF) and diabetes mellitus (DM), the exact underlying common mechanism of its occurrence is unclear. This study aims to explore further the molecular mechanism between these two diseases. MethodsThe microarray data of idiopathic pulmonary fibrosis and diabetes mellitus in the Gene Expression Omnibus (GEO) database were downloaded. Weighted Gene Co-Expression Network Analysis (WGCNA) was used to identify co-expression genes related to idiopathic pulmonary fibrosis and diabetes mellitus. Subsequently, differentially expressed genes (DEGs) analysis and three public databases were employed to analyze and screen the gene targets related to idiopathic pulmonary fibrosis and diabetes mellitus. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed by Metascape. In addition, common microRNAs (miRNAs), common in idiopathic pulmonary fibrosis and diabetes mellitus, were obtained from the Human microRNA Disease Database (HMDD), and their target genes were predicted by miRTarbase. Finally, we constructed a common miRNAs-mRNAs network by using the overlapping genes of the target gene and the shared gene. ResultsThe results of common gene analysis suggested that remodeling of the extracellular matrix might be a key factor in the interconnection of DM and IPF. Finally, hub genes (MMP1, IL1R1, SPP1) were further screened. miRNA-gene network suggested that has-let-19a-3p may play a key role in the common molecular mechanism between IPF and DM. ConclusionsThis study provides new insights into the potential pathogenic mechanisms between idiopathic pulmonary fibrosis and diabetes mellitus. These common pathways and hub genes may provide new ideas for further experimental studies.
ObjectiveTo investigate the causal relationship between gut microbiota and idiopathic pulmonary fibrosis (IPF). MethodsGenome-wide association studies (GWAS) data of gut microbiota and IPF were obtained from MiBioGen and Finngen databases, respectively. Instrumental variables were screened by means of significance, linkage disequilibrium, weak instrumental variable screening, and removal of confounding factors (genetics, smoking, host characteristics). Inverse variance weighted (IVW) was used as the main Mendelian randomization (MR) analysis method, and the weighted median, simple mode, MR-Egger, and weighted mode were used to perform MR to reveal the causal effect of gut microbiota and IPF. The Cochrane's Q, leave-one-out, MR-Egger-intercept, and Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) and Steiger tests were used to analyze the heterogeneity, horizontal pleiotropy, outliers, and directionality, respectively. ResultsIVW analysis results showed that Actinomycetes [OR=1.773, 95%CI (1.323, 2.377), P<0.001], Erysipelatoclostridium [OR=2.077, 95%CI (1.107, 3.896), P=0.023], and Streptococcus [OR=1.35, 95%CI (1.100, 1.657), P=0.004] could increase the risk of IPF. Bifidobacterium [OR=0.668, 95%CI (0.620, 0.720), P<0.001], Ruminococcus [OR=0.434, 95%CI (0.222,0.848), P=0.015], and Tyzzerella [OR=0.479, 95%CI (0.304, 0.755), P=0.001] could reduce the risk of IPF. No significant heterogeneity, horizontal pleiotropy, outliers, and reverse causality were found. ConclusionActinobacteria, Erysipelatoclostridium and Streptococcus may increase the risk of IPF, while Bifidobacterium, Ruminococcus and Tyzzerella may reduce the risk of IPF. Regulation of the above gut microbiota may become a new direction in the study of the pathogenesis of IPF.
Objective To investigate the role of IFN-γ in suppressing bleomycin-induced pulmonary fibrosis in rats.Methods Seventy-five SD rats were randomly divided into five groups (15 rats in each group)，ie.a normal group，a bleomycin-induced pulmonary fibrosis model group，a dexamethasone-treated group，a high-dose IFN-γ-treated group (150 000 U/kg) and a low-dose IFN-γ-treated group (50 000 U/kg).Five rats in each group were randomly killed in 7th day，14th day and 28th day after relative treatment respectively，and lung tissue samples were harvested for histopathology study.HE and Masson staining were used to determine the extent of alveolus inflammation and pulmonary fibrosis respectively.Histoimmunochemical method were adapted to determine protein levels of TGF-β1，CTGF，type Ⅰcollagen and type Ⅲ collagen in pulmonary tissues.Results Histopathological study showed that treatment with either dexamethasone or IFN-γ (both high dose and low dose) remarkably meliorated the extent of alveolus inflammation and suppressed pulmonary fibrosis (compared with model group，all Plt;0.05).Histoimmunochemical study suggested that both dexamethasone and IFN-γ could inhibit the expression of TGF-β1，CTGF，type Ⅰand type Ⅲ collagen (compared with model group，all Plt;0.05)，and the suppression of TGF-β1，type Ⅰand type Ⅲ collagen expression was more obvious in high-dose IFN-γ-treated group than those in low-dose group (Plt;0.05).Conclusions INF-γ possesses apparent anti-fibrosis effect that is similar to dexamethasone but with less side effect.Such effect may resulted from reduced production of type Ⅰand type Ⅲ collagen through expression inhibition of cytokines such as TGF-β1 and CTGF.
Objective To investigate the prevalence of obstructive sleep apnea hypopnea syndrome ( OSAHS) in patients with idiopathic pulmonary fibrosis ( IPF) and its clinical significance. Methods Sleep quality and breathing disorders were measured by polysomnography and the relationship with lung function was analyzed in 20 IPF patients. Results Thirteen of 20 subjects ( 65% ) had OSAHS as defined by an AHI ≥5 events per hour. Three subjects ( 15% ) had mild OSAHS ( AHI,5 to 20 events per hour) , and 10 subjects ( 50% ) had moderate-to-severe OSAHS ( AHI≥20 events per hour) . The sleep architecture in these patients showed a reduction in sleep efficiency, rapid eye movement ( REM) sleep and slow wave sleep, and a marked sleep fragmentation due to an increased arousal index. The AHI was negatively correlated with FVC% pred ( r =-0.672, P=0.001) and FEV1% pred ( r =-0.659, P=0.002) , and positively correlated with body mass index ( BMI) ( r=0.791, Plt;0.0001) . Conclusions OSAHS is a common comorbidity in IPF. Early treatment of OSAHS may improve quality of life and the prognosis of patients with IPF.