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.
Objective To investigate the preventive therapeutic effects of CPD1, a novel phosphodiesterase 5 inhibitor, on lung pathological phenotype and interstitial fibrosis of lung in pulmonary fibrosis model rats caused by bleomycin (BLM). Methods Rats were randomly divided into a sham surgery group (n=10), a model group (n=14), a CPD1 treatment group (n=13), and a nintedanib positive control drug treatment group (n=13). Pulmonary fibrosis model was constructed by slowly instilling BLM (3 mg/kg) into the left bronchus in the model group and two treatment groups. Two hours after BLM infusion, the rats were treated with CPD1 (20 mg·kg–1·d–1), or positive control drug nintedanib (50 mg·kg–1·d–1) by intragastric administration, respectively, for 2 weeks. To observe the effect of CPD1 treatment on pathological structural damage, collagen deposition, and the expression of fibronectin (Fn), α-smooth muscle actin (α-SMA), Collagen Ⅰ, and E-cadherin (E-Cad) in the affected lung tissues of unilateral pulmonary fibrosis rats. Moreover, to further observed the effects of CPD1 intervention on the expression of transforming growth factor β1 (TGF-β1) and Smad3 in the cell model of human alveolar basal epithelial A549 cells. Results Compared with the control group, the lung tissue structure was seriously damaged in the BLM group, and with expansion of the alveolar space, collapse of the alveolar lumen. Significant widening of the alveolar septum and thickening of the alveolar wall were observed in the BLM group. There was a marked increase in collagen deposition in the thickened walls of the BLM group. Moreover, the expressions of Fn, α-SMA, Collagen Ⅰ, TGF-β and Smad3 were increased, while the expression of E-Cad significantly decreased in the BLM group (all P<0.05). Compared with the BLM group, the lung tissue damage was significantly improved in the CPD1 group rats. Furthermore, CPD1 inhibit the expression of Fn, α-SMA, Collagen Ⅰ, TGF-β and Smad3, and upregulate the expression of E-Cad (all P<0.05). Conclusions Prophylactic treatment with phosphodiesterase 5 inhibitor CPD1 strongly attenuates BLM-induced pulmonary fibrosis by inhibiting the lung injury and inflammation response via targeting TGF-β/Smad pathway, reducing the deposition of extracellular matrix.
ObjectiveTo investigate the effect of diammonium glycyrrhizinate (DG) plus bone marrow mesenchymal stem cells (MSCs) transplantation in the treatment of acute exacerbation of pulmonary fibrosis induced by bleomycin (BLM) in rats.MethodsMSCs were isolated from male Wistar rats and cultured in vitro. Twenty-four female Wistar rats were randomly divided into 4 groups. The NC group was intratracheally injected with normal saline; the BLM group, the MSC group and the DGMSC group were intratracheally injected with BLM for 7 days; then the MSC group was injected with 0.5 mL of MSCs solution (2.5×106 cells) into the tail vein; the DGMSC group was intraperitoneally injected with DG for 21 days in a dose of 150 mg·kg–1·d–1 on the base of the MSCs injection. The rats were sacrificed on the 28th day and the lung tissue was extracted. Pathological examination was performed to determine the degree of alveolitis and pulmonary fibrosis. Immunofluorescence was used to detect the number and distribution of alveolar type Ⅱ epithelial cells. Alkali hydrolysis method was used to determine the content of hydroxyproline (HYP) in lung tissue; thiobarbituric acid method was used to measure the content of malondialdehyde (MDA) in lung tissue; colorimetric method was used to determine the superoxide dismutase activity (SOD) and total antioxidant capacity (T-AOC); enzyme linked immunosorbent assay was used to detect the expression levels of tumor necrosis factor-α (TNF-α ) and transforming growth factor-β1 (TGF-β1) in lung tissue homogenates.ResultsThe DG combined with MSCs injection can reduce the degree of alveolitis and pulmonary fibrosis in BLM model rats. The content of HYP and TGF-β1 in lung tissue homogenate of the DGMSC group were significantly lower than those in the MSC group (P<0.05). Meanwhile, DG combined with MSCs injection significantly increased the antioxidant capacity of the BLM model rats. MDA content decreased, SOD activity and T-AOC ability improved significantly in the DGMSC group compared with the MSC group (P<0.05). The alveolar type Ⅱ epithelial cells were significantly increased and the cell morphology was maintained in the DGMSC group compared with the MSC group.ConclusionsDG has a synergistic effect with MSCs in treatment of acute exacerbation of pulmonary fibrosis. The mechanism may be related to reducing inflammatory factors during pulmonary fibrosis, attenuating oxidative stress and promoting MSCs migration into lung tissue and transformation to alveolar type Ⅱ epithelial cells.
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.
Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is defined as an acute and clinically significant respiratory deterioration characterized by evidence of new, widespread alveolar abnormality. In the past, AE-IPF was considered to be idiopathic, which was hard to be prevented and its prognosis was hard to be obviously improved; the latest researches have shown that AE-IPF can be triggered by known causes, including pulmonary infection, aspiration, etc. This review summarizes the etiology or risk factors, treatment and prevention of AE-IPF according to the latest researches.
Objective To explore the role of chronic ethanol ingestion in pulmonary fibrosis. Methods Twenty SD rats were randomly divided into a control group (n=10) and an ethanol group ( n=10) , and fed with quantitative non-ethanol and ethanol Lieber-DeCarli liquid diet every day respectively. All rats were sacrificed after 8 weeks. The morphological changes and collagen deposition of lung tissue were observed under light microscope by HE and Masson staining. Levels of glutathione (GSH) and hydroxyproline (HYP) in lung tissues were measured by colorimetric method. The content of connective tissue growth factor (CTGF) in lung tissue was detected by ELISA. Results Compared with the control group, varied degrees of alveolar and alveolar septal infiltration of inflammatory cells can be shown in the ethanol group, and also some alveolar wall damage or collapse.Masson staining showed that the ethanol group has more significant deposition of collagen fibers in alveolar interstitumthan the control group. The content of GSH in rat lung tissue reduced, but the contents of HYP and CTGF increased in the ethanol group compared with the control group [ GSH( mg/g) :0.08±0.04 vs. 0.22±0.14, HYP(mg/g) : 0.57±0.15 vs. 0.40 ± 0.09, CTGF(ng/mL) :306.57±46.86 vs. 134.02±79.82, Plt;0.05] . Conclusions Lieber-DeCarli ethanol liquid diet can establish a rat model of chronic ethanol ingestion. Lung injury and pulmonary fibrosis in rats can be induced by chronic ethanol ingestion. Ethanol may be one of the causes of the pulmonary fibrosis.
Idiopathic pulmonary fibrosis (IPF) is a progressive scar-forming disease with a high mortality rate that has received widespread attention. Epithelial mesenchymal transition (EMT) is an important part of the pulmonary fibrosis process, and changes in the biomechanical properties of lung tissue have an important impact on it. In this paper, we summarize the changes in the biomechanical microenvironment of lung tissue in IPF-EMT in recent years, and provide a systematic review on the effects of alterations in the mechanical microenvironment in pulmonary fibrosis on the process of EMT, the effects of mechanical factors on the behavior of alveolar epithelial cells in EMT and the biomechanical signaling in EMT, in order to provide new references for the research on the prevention and treatment of IPF.
Objective To study the risk factors of developing progressive pulmonary fibrosis (PPF) within one year in patients diagnosed with rheumatoid arthritis-associated interstitial lung disease (RA-ILD), and develop a nomogram. Methods A retrospective study was conducted in 145 cases of RA-ILD patients diagnosed and followed up in the Affiliated Hospital of Qingdao University from January 2010 to October 2022. Among them, 106 patients and 39 patients were randomly assigned to a training group and a verification group. The independent predictors of PPF in patients with RA-ILD within one year were determined by univariate and multivariate logistic regression analysis. Then a nomogram is established through these independent predictive variables. Calibration curve, Hosmer-Lemeshow test, receiver operating characteristic (ROC) curve and area under ROC curve (AUC) and clinical decision curve were used to evaluate the predictive efficiency of the nomogram model for PPF in RA-ILD patients within one year. Finally, internal validation was used to test the stability of the model. Results Of the 145 patients with RA-ILD, 62 (42.76%) developed PPF within one year, including 40 (37.7%) in the training group and 22 (56.41%) in the verification group. The PPF patients had higher proportion of subpleural abnormalities, higher visual score of fibrosis and shorter duration of RA. Logistic regression analysis showed that the duration of rheumatoid arthritis (RA), visual score of fibrosis and subpleural abnormality were independent risk factors for the occurrence of PPF within one year after diagnosis of RA-ILD. A nomogram was constructed based on these independent risk factors. The AUC values of the training group and the verification group were 0.798 (95%CI 0.713 - 0.882) and 0.822 (95%CI 0.678 - 0.967) respectively, indicating that the model had a good ability to distinguish. The clinical decision curve showed that the clinical benefit of PPF risk prediction model was greater when the risk threshold was between 0.06 and 0.71. Conclusion According to the duration of RA, the visual score of fibrosis and the presence of subpleural abnormalities, the predictive model of PPF was drawn to provide reference for the clinical prediction of PPF in patients with RA-ILD within one year after diagnosis.
Objective To investigate the impact and mechanisms of periostin (POSTN), Krebs von den Lungen-6 (KL-6), pulmonary surfactant protein A (SP-A), and pulmonary surfactant protein D (SP-D) on the diagnosis and disease assessment of idiopathic pulmonary fibrosis (IPF), and conduct a comparative analysis. Methods From October 2022 to October 2023, a total of 55 patients diagnosed with IPF and treated at the Third Affiliated Hospital of Anhui Medical University were enrolled as an IPF group. Additionally, 30 patients with bacterial pneumonia and 30 healthy individuals undergoing concurrent health examinations during the same period were selected as a pneumonia control group and a healthy control group, respectively. All participants underwent enzyme-linked immunosorbent assay to measure serum levels of POSTN, KL-6, SP-A, and SP-D, along with pulmonary function tests. The IPF patients also underwent high-resolution computed tomography (HRCT) and echocardiography to quantify HRCT scores and pulmonary artery systolic pressure (PASP). Receiver operating characteristic (ROC) curves were plotted to analyze the significance of serum POSTN, KL-6, SP-A, and SP-D levels in IPF diagnosis. Pearson and Spearman correlation tests were used to analyze the relationships between these biomarkers and pulmonary function, PASP, and HRCT scores. Results Serum concentrations of POSTN, KL-6, SP-A, and SP-D were significantly elevated in the IPF group compared with the pneumonia group and the healthy controls (P<0.05), while serum levels of SP-A and SP-D were notably higher in the pneumonia group compared with the healthy control group (P<0.05). Within the IPF group, serum POSTN levels were negatively correlated with forced expiratory volume in the first second as a percentage of predicted value (FEV1%pred) and diffusion capacity of the lung for carbon monoxide as a percentage of predicted value (DLCO%pred) (P<0.05); KL-6 and SP-D levels were also negatively correlated with FEV1%pred, forced vital capacity as a percentage of predicted value (FVC%pred), and DLCO%pred (P<0.05); and the concentration of SP-A was negatively correlated with DLCO%pred and positively correlated with PASP (P<0.05). Additionally, serum levels of POSTN, KL-6, and SP-A in the IPF group showed significant positive associations with HRCT scores (P<0.01). Conclusions POSTN is a valuable serum biomarker for IPF, exhibiting the highest sensitivity and specificity among the four serum markers, with diagnostic performance superior to KL-6, SP-A, and SP-D. POSTN, KL-6, SP-A, and SP-D can all be used for the diagnosis and assessment of IPF.
Objective To observe the effects of cigarette smoke extract ( CSE) on the proliferation and secretion of hydrogen peroxide ( H2O2 ) in human lung fibroblasts ( HLFs) induced by transforming growth factor-β1 ( TGF-β1 ) . Methods Cultured HLFs were divided into a normal group and a model group induced by TGF-β1 ( 5 ng/mL) , then intervened with CSE at different concentrations ( 0% , 2. 5% , 5% ,10% , respectively) . Brdu ELISA assay was used to detect cell proliferation. H2O2 release from cultured cells was assayed using a fluorimetric method. Cellular localization of H2O2 and expression of α-SMA were performed using a fluorescent-labeling strategy. Results TGF-β1 stimulated group showed positive expression of α-SMA, implying TGF-β1 had induced fibroblasts to differentiate into myofibroblasts. In TGF-β1 stimulated group, 2. 5% and 5% CSE promoted cell proliferation ( P lt; 0. 01 or 0. 05) , while 10% CSE inhibited cell proliferation ( P lt; 0. 01) . In the normal group, both low and high concentration of CSE inhibited cell proliferation ( P lt; 0. 01 or P lt; 0. 05) , and the inhibition effect was dose-dependent. HLF induced by TGF-β1 generated low constitutive levels of extracellular H2O2 that was markedly enhanced by CSE treatment ( P lt; 0. 01) . Pretreatment with DPI, an inhibitor of NADPH oxidase, abolished secretion of H2O2 . Cellular localization of H2O2 by a fluorescent-labeling strategy demonstrated that extracellular secretion of H2O2 is specific to the myofibroblast. Conclusions Low concentration of CSE can promote myofibroblast proliferation, and markedly increase extracellular secretion of H2O2 . CSE possibly take part in the development and progress of idiopathic pulmonary fibrosis by increasing oxidative stress.