Evaluation of Correlations between Genetic Variants and High-Resolution Computed Tomography Patterns in Idiopathic Pulmonary Fibrosis

Relative incidence of interstitial lung diseases in Brazil

OBJECTIVE

To assess the relative frequency of incident cases of interstitial lung diseases (ILDs) in Brazil.

METHODS

This was a retrospective survey of new cases of ILD in six referral centers between January of 2013 and January of 2020. The diagnosis of ILD followed the criteria suggested by international bodies or was made through multidisciplinary discussion (MDD). The condition was characterized as unclassifiable ILD when there was no specific final diagnosis following MDD or when there was disagreement between clinical, radiological, or histological data.

RESULTS

The sample comprised 1,406 patients (mean age = 61 ± 14 years), and 764 (54%) were female. Of the 747 cases exposed to hypersensitivity pneumonitis (HP)-related antigens, 327 (44%) had a final diagnosis of HP. A family history of ILD was reported in 8% of cases. HRCT findings were indicative of fibrosis in 74% of cases, including honeycombing, in 21%. Relevant autoantibodies were detected in 33% of cases. Transbronchial biopsy was performed in 23% of patients, and surgical lung biopsy, in 17%. The final diagnoses were: connective tissue disease-associated ILD (in 27%), HP (in 23%), idiopathic pulmonary fibrosis (in 14%), unclassifiable ILD (in 10%), and sarcoidosis (in 6%). Diagnoses varied significantly among centers (c2 = 312.4; p < 0.001).

CONCLUSIONS

Our findings show that connective tissue disease-associated ILD is the most common ILD in Brazil, followed by HP. These results highlight the need for close collaboration between pulmonologists and rheumatologists, the importance of detailed questioning of patients in regard with potential exposure to antigens, and the need for public health campaigns to stress the importance of avoiding such exposure.

Radiological usual interstitial pneumonia pattern is associated with two-year mortality in patients with idiopathic pulmonary fibrosis

Introduction

The new diagnostic guidelines for idiopathic pulmonary fibrosis (IPF) did not rule out the possibility of combining the radiological patterns of usual interstitial pneumonia (UIP) and probable UIP, given the similar management and diagnostic capacity. However, the prognostic implications of these patterns have not been fully elucidated, with different studies showing heterogeneous results. We applied the new criteria to a retrospective series of patients with IPF, assessing survival based on radiological patterns, findings, and their extension.

Methods

Two thoracic radiologists reviewed high-resolution computed tomography images taken at diagnosis in 146 patients with IPF, describing the radiological findings and patterns. The association of each radiological finding and radiological patterns with two-year mortality was analysed.

Results

The two-year mortality rate was 40.2% in IPF patients with an UIP radiological pattern versus 7.1% in those with probable UIP. Compared to the UIP pattern, probable UIP was protective against mortality, even after adjusting for age, sex, pulmonary function, and extent of fibrosis (hazard ratio (HR) 0.23, 95% confidence interval (CI) 0.06-0.99). Receiving antifibrotic treatment was also a protective factor (HR 0.51, 95%CI 0.27-0.98). Honeycombing (HR 3.62, 95%CI 1.27-10.32), an acute exacerbation pattern (HR 4.07, 95%CI 1.84-8.96), and the overall extent of fibrosis (HR 1.04, 95%CI 1.02-1.06) were predictors of mortality.

Conclusions

In our series, two-year mortality was higher in patients with IPF who presented a radiological pattern of UIP versus probable UIP on the initial scan. Honeycombing, an acute exacerbation pattern, and a greater overall extent of fibrosis were also predictors of increased mortality. The prognostic differences between the radiological pattern of UIP and probable UIP in our series would support maintaining them as two differentiated patterns.

The association between patient preoperative disposition and outcomes after diagnostic lung biopsy

Background

Surgical diagnostic lung biopsy (DLB) is performed to guide the management of pulmonary disease with unclear etiology. However, the utilization of surgical DLB in critically ill patients remains unclear. The purpose of this study was to determine if patient preoperative disposition impacts complication rates after DLB.

Methods

This was retrospective cohort study using electronic health record (EHR) data at one academic institution [2013-2021]. Patients who underwent DLB were identified using current procedural terminology (CPT) codes and cohorted based on preoperative disposition. The primary outcome was 30-day mortality; secondary outcomes were overall morbidity, individual complications, and changes to medical therapy. Complication rates were compared using chi-squared tests, Fisher's exact tests, or analysis of variance (ANOVA). Multivariable logistic regression was performed to generate risk-adjusted odds ratios (ORs) for each complication.

Results

Of 285 patients, 238 (83.5%) presented from home, 26 (9.1%) from inpatient floor units, and 21 (7.4%) from intensive care units (ICUs). Patients requiring ICU had the highest 30-day rates of mortality, overall morbidity, and all individual complications (all P<0.05). After risk adjustment, non-ICU inpatients had higher odds of postoperative ventilator use, prolonged ventilation, and ICU need than outpatients (all P<0.05). Preoperative ICU disposition was associated with increased OR of 30-day mortality [OR, 70.92; 95% confidence interval (CI): 5.55-906.32] and overall morbidity (OR, 7.27; 95% CI: 1.93-27.42) compared to patients with other preoperative dispositions. There were no differences in changes to medical therapy between the cohorts.

Conclusions

Patients requiring ICU before DLB had significantly higher risk-adjusted rates of mortality and postoperative complications than outpatients and other inpatients. A clear benefit from tissue diagnosis should be defined prior to performing DLB on critically ill patients.

Functional Progression after Dose Suspension or Discontinuation of Nintedanib in Idiopathic Pulmonary Fibrosis: A Real-Life Multicentre Study

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease with rapidly progressive evolution and an unfavorable outcome. Nintedanib (NTD) is an antifibrotic drug that has been shown to be effective in slowing down the progression of the disease. The aim of our study was to examine the efficacy, especially in terms of the functional decline, and the safety profile of NTD in patients treated with the recommended dose and subjects who reduced or suspended the therapy due to the occurrence of adverse reactions.

METHODS

We conducted a real-life retrospective study based on the experience of NTD use in two centers between 2015 and 2022. Clinical data were evaluated at baseline, at 6 and 12 months after the NTD introduction in the whole population and in subgroups of patients who continued the full-dose treatment, at a reduced dosage, and at the discontinuation of treatment. The following data were recorded: the demographic features, IPF clinical features, NTD therapeutic dosage, tolerability and adverse events, pulmonary function tests (PFTs), the duration of treatment upon discontinuation, and the causes of interruption.

RESULTS

There were 54 IPF patients who were included (29.6% females, with a median (IQR) age at baseline of 75 (69.0-79.0) years). Twelve months after the introduction of the NTD therapy, 20 (37%) patients were still taking the full dose, 11 (20.4%) had reduced it to 200 mg daily, and 15 (27.8%) had stopped treatment. Gastrointestinal intolerance predominantly led to the dose reduction (13.0%) and treatment cessation (20.4%). There were two deaths within the initial 6 months (3.7%) and seven (13.0%) within 12 months. Compared to the baseline, the results of the PFTs remained stable at 6 and 12 months for the entire NTD-treated population, except for a significant decline in the DLCO (% predicted value) at both 6 (38.0 ± 17.8 vs. 43.0 ± 26.0; p = 0.041) and 12 months (41.5 ± 15.3 vs. 44.0 ± 26.8; p = 0.048). The patients who continued treatment at the full dose or a reduced dosage showed no significant differences in the FVC and the DLCO at 12 months. Conversely, those discontinuing the NTD exhibited a statistically significant decline in the FVC (% predicted value) at 12 months compared to the baseline (55.0 ± 13.5 vs. 70.0 ± 23.0; p = 0.035).

CONCLUSIONS

This study highlights the functional decline of the FVC at 12 months after the NTD initiation among patients discontinuing therapy but not among those reducing their dosage.

Olfactory mucosa mesenchymal stem cells alleviate pulmonary fibrosis via the immunomodulation and reduction of inflammation

BACKGROUND

Pulmonary fibrosis (PF) is a progressive fibrosing interstitial pneumonia that leads to respiratory failure and other complications, which is ultimately fatal. Mesenchymal stem cells (MSCs) transplant is a promising strategy to solve this problem, while the procurement of MSCs from the patient for autotransplant remains a challenge.

METHODS

Here, we presented olfactory mucosa mesenchymal stem cells (OM-MSCs) from mouse turbinate and determined the preventing efficacy of allotransplant for PF. We demonstrated the antiinflammation and immunomodulatory effects of OM-MSCs. Flow cytometric analysis was used to verify the effect of OM-MSCs on monocyte-derived macrophage populations in the lung.

RESULTS

Administration of OM-MSCs reduces inflammation, attenuates the matrix metallopeptidase 13 (MMP13) expression level and restores the bleomycin (BLM)-induced pulmonary fibrosis by assessing the architecture of lung, collagen type I; (COL1A1), actin alpha 2, smooth muscle, aorta (ACTA2/α-SMA) and hydroxyproline. This therapeutic effect of OM-MSCs was related to the increase in the ratio of nonclassical monocytes to proinflammatory monocytes in the lung.

CONCLUSIONS

This study suggests that transplant of OM-MSCs represents an effective and safe treatment for PF.

ILD-GAP combined with the monocyte ratio could be a better prognostic prediction model than ILD-GAP in patients with interstitial lung diseases

BACKGROUND

The ILD-GAP scoring system is known to be useful in predicting prognosis in patients with interstitial lung disease (ILD). An elevated monocyte count was associated with increased risks of IPF poor prognosis. We examined whether the ILD-GAP scoring system combined with the monocyte ratio (ILD-GAPM) is superior to the conventional ILD-GAP model in predicting ILD prognosis.

METHODS

In patients with ILD treated between April 2013 and April 2017, we were retrospectively assessed the relationships between baseline clinical parameters, including age, sex, Charlson Comorbidity Index score (CCIS), ILD diagnosis, blood biomarkers, pulmonary function test results, and disease outcomes. In ILD patients were included idiopathic pulmonary fibrosis (IPF), idiopathic nonspecific interstitial pneumonia (iNSIP), collagen vascular disease-related interstitial pneumonia (CVD-IP), chronic hypersensitivity pneumonitis (CHP), and unclassifiable ILD (UC-ILD). We also assessed the ability to predict prognosis was compared between the ILD-GAP and ILD-GAPM models.

RESULTS

A total of 179 patients (mean age, 73 years) were assessed. All of them were taken pulmonary function test, including percentage predicted diffusion capacity for carbon monoxide. ILD patients included 56 IPF cases, 112 iNSIP and CVD-IP cases, 6 CHP cases and 5 UC-ILD cases. ILD-GAPM provided a greater area under the receiver-operating characteristic curve (0.747) than ILD-GAP (0.710) for predicting 3-year ILD-related events. Furthermore, the log-rank test showed that the Kaplan-Meier curves in ILD-GAPM were significantly different by stage (P = 0.015), but not by stage in ILD-GAP (P = 0.074).

CONCLUSIONS

The ILD-GAPM model may be a more accurate predictor of prognosis for ILD patients than the ILD-GAP model.

Genetic association analysis of dietary intake and idiopathic pulmonary fibrosis: a two-sample mendelian randomization study

BACKGROUND

IPF is a complex lung disease whose aetiology is not fully understood, but diet may have an impact on its development and progression. Therefore, we investigated the potential causal connection between dietary intake and IPF through TSMR to offer insights for early disease prevention recommendations.

METHODS

The study incorporated 29 dietary exposure factors, oily fish intake, bacon intake, processed meat intake, poultry intake, beef intake, pork intake, lamb/mutton intake, non-oily fish intake, fresh fruit intake, cooked vegetable intake, baked bean intake, fresh tomato intake, tinned tomato intake, salad/raw vegetable intake, Fresh fruit intake, coffee intake, tea intake, water intake, red wine intake, average weekly beer plus cider intake, alcoholic drinks per week, cereal intake, bread intake, whole-wheat intake, whole-wheat cereal intake, cheese intake, yogurt intake, salt added to food and whole egg intake. The study explored the causal link between diet and IPF using TSMR analysis, predominantly the IVW method, and performed sensitivity analyses to validate the results.

RESULT

The study revealed that consuming oily fish, yogurt, and dried fruits had a protective effect against IPF, whereas the consumption of alcoholic beverages and beef was linked to an increased risk of IPF.

CONCLUSION

In this MR study, it was discovered that the consumption of oily fish, yogurt, and dried fruits exhibited a protective effect against IPF, whereas the intake of alcoholic beverages and beef was associated with an elevated risk of IPF. These findings underscore the significance of making informed and timely dietary decisions in IPF prevention.

Development of a Novel Biomarker for the Progression of Idiopathic Pulmonary Fibrosis

The progression of idiopathic pulmonary fibrosis (IPF) is diverse and unpredictable. We identified and validated a new biomarker for IPF progression. To identify a candidate gene to predict progression, we assessed differentially expressed genes in patients with advanced IPF compared with early IPF and controls in three lung sample cohorts. Candidate gene expression was confirmed using immunohistochemistry and Western blotting of lung tissue samples from an independent IPF clinical cohort. Biomarker potential was assessed using an enzyme-linked immunosorbent assay of serum samples from the retrospective validation cohort. We verified that the final candidate gene reflected the progression of IPF in a prospective validation cohort. In the RNA-seq comparative analysis of lung tissues, CD276, COL7A1, CTSB, GLI2, PIK3R2, PRAF2, IGF2BP3, and NUPR1 were up-regulated, and ADAMTS8 was down-regulated in the samples of advanced IPF. Only CTSB showed significant differences in expression based on Western blotting (n = 12; p < 0.001) and immunohistochemistry between the three groups of the independent IPF cohort. In the retrospective validation cohort (n = 78), serum CTSB levels were higher in the progressive group (n = 25) than in the control (n = 29, mean 7.37 ng/mL vs. 2.70 ng/mL, p < 0.001) and nonprogressive groups (n = 24, mean 7.37 ng/mL vs. 2.56 ng/mL, p < 0.001). In the prospective validation cohort (n = 129), serum CTSB levels were higher in the progressive group than in the nonprogressive group (mean 8.30 ng/mL vs. 3.00 ng/mL, p < 0.001). After adjusting for baseline FVC, we found that CTSB was independently associated with IPF progression (adjusted OR = 2.61, p < 0.001). Serum CTSB levels significantly predicted IPF progression (AUC = 0.944, p < 0.001). Serum CTSB level significantly distinguished the progression of IPF from the non-progression of IPF or healthy control.

Advances in Diagnostics and Management of Respiratory System Diseases

Recently, significant innovations in the diagnosis and management of respiratory diseases have been developed [...].

Efficacy and Safety of Hydrogen Therapy in Patients with Early-Stage Interstitial Lung Disease: A Single-Center, Randomized, Parallel-Group Controlled Trial

Purpose

Several in vivo experiments have shown that molecular hydrogen is a promising therapeutic agent for interstitial lung diseases (ILD). In this study, hydrogen therapy was investigated to determine whether it is superior to N-Acetylcysteine (NAC) for the treatment of patients with early-stage ILD.

Patients and Methods

A prospective, single-center, randomized, controlled clinical trial was conducted in 87 patients with early-stage ILD. Hydrogen or NAC therapy was randomly assigned (1:1 ratio) to the eligible patients. The primary endpoint was the change in the high-resolution computed tomography (HRCT) and composite physiologic index (CPI) scores from baseline to week 48. Pulmonary function was evaluated as a secondary endpoint, and adverse events were recorded for safety analysis.

Results

The rate of HRCT image improvement from the baseline in the HW group (63.6%) was higher than that in the NAC group (39.5%). A significant decrease in CPI and improvement in DLCO-sb were observed in the hydrogen group compared with those in the control group. Changes in other pulmonary function parameters, including FVC, FEV1, FEV1/FVC%, and TLC, were not significantly different between the two groups. Adverse events were reported in 7 (15.9%) patients in the HW group and 10 (23.3%) patients in the NAC group, but the difference was not significant (P=0.706).

Conclusion

Hydrogen therapy exhibits superior efficacy and acceptable safety compared with NAC therapy in patients with early-stage ILD.

Daphnetin Alleviates Bleomycin-Induced Pulmonary Fibrosis through Inhibition of Epithelial-to-Mesenchymal Transition and IL-17A

Idiopathic pulmonary fibrosis (IPF) is a chronic and refractory interstitial lung disease. Although there is no cure for IPF, the development of drugs with improved efficacy in the treatment of IPF is required. Daphnetin, a natural coumarin derivative, has immunosuppressive, anti-inflammatory, and antioxidant activities. However, its antifibrotic effects have not yet been elucidated. In this study, we investigated the antifibrotic effects of daphnetin on pulmonary fibrosis and the associated molecular mechanism. We examined the effects of daphnetin on splenocytes cultured in Th17 conditions, lung epithelial cells, and a mouse model of bleomycin (BLM)-induced pulmonary fibrosis. We identified that daphnetin inhibited IL-17A production in developing Th17 cells. We also found that daphnetin suppressed epithelial-to-mesenchymal transition (EMT) in TGF-β-treated BEAS2B cells through the regulation of AKT phosphorylation. In BLM-treated mice, the oral administration of daphnetin attenuated lung histopathology and improved lung mechanical functions. Our findings clearly demonstrated that daphnetin inhibited IL-17A and EMT both in vitro and in vivo, thereby protecting against BLM-induced pulmonary fibrosis. Taken together, these results suggest that daphnetin has potent therapeutic effects on lung fibrosis by modulating both Th17 differentiation and the TGF-β signaling pathway, and we thus expect daphnetin to be a drug candidate for the treatment of IPF.

A three-gene random forest model for diagnosing idiopathic pulmonary fibrosis based on circadian rhythm-related genes in lung tissue

BACKGROUND

The disorder of circadian rhythm could be a key factor mediating fibrotic lung disease Therefore, our study aims to determine the diagnostic value of circadian rhythm-related genes (CRRGs) in IPF.

METHODS

We retrieved the data on CRRGs from previous studies and the GSE150910 dataset. The participants from the GSE150910 dataset were divided into training and internal validation sets. Next, we used several various bioinformatics methods and machine learning algorithms to screen genes. Next, we identified SEMA5A, COL7A1, and TUBB3, which were included in the random forest (RF) diagnostic model. Finally, external validation was conducted on data retrieved from the GSE184316 datasets.

RESULTS

The results revealed that the RF diagnostic model could diagnose patients with IPF in the internal validation set with the area under the ROC curve (AUC) value of 0.905 and in the external validation with the AUC value of 0.767. Furthermore, real-time quantitative PCR and western blotting results revealed a significant decrease in SEMA5A (p < 0.05) expression level and an increase in COL7A1 and TUBB3 expression levels in TGF-β1-treated normal human lung fibroblasts.

CONCLUSION

We constructed an RF diagnostic model based on SEMA5A, COL7A1, and TUBB3 expression in lung tissue for diagnosing patients with IPF.

Cellular Senescence: A Troy Horse in Pulmonary Fibrosis

Pulmonary fibrosis (PF) is a chronic interstitial lung disease characterized by myofibroblast abnormal activation and extracellular matrix deposition. However, the pathogenesis of PF remains unclear, and treatment options are limited. Epidemiological studies have shown that the average age of PF patients is estimated to be over 65 years, and the incidence of the disease increases with age. Therefore, PF is considered an age-related disease. A preliminary study on PF patients demonstrated that the combination therapy of the anti-senescence drugs dasatinib and quercetin improved physical functional indicators. Given the global aging population and the role of cellular senescence in tissue and organ aging, understanding the impact of cellular senescence on PF is of growing interest. This article systematically summarizes the causes and signaling pathways of cellular senescence in PF. It also objectively analyzes the impact of senescence in AECs and fibroblasts on PF development. Furthermore, potential intervention methods targeting cellular senescence in PF treatment are discussed. This review not only provides a strong theoretical foundation for understanding and manipulating cellular senescence, developing new therapies to improve age-related diseases, and extending a healthy lifespan but also offers hope for reversing the toxicity caused by the massive accumulation of senescence cells in humans.

Idiopathic pulmonary fibrosis: Addressing the current and future therapeutic advances along with the role of Sotatercept in the management of pulmonary hypertension

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive and debilitating lung disease characterized by irreversible scarring of the lungs. The cause of IPF is unknown, but it is thought to involve a combination of genetic and environmental factors. There is no cure for IPF, and treatment is focused on slowing disease progression and relieving symptoms.

AIMS

We aimed in this review to investigate and provide the latest insights into IPF management modalities, including the potential of Saracatinibas a substitute for current IPF drugs. We also investigated the therapeutic potential of Sotatercept in addressing pulmonary hypertension associated with IPF.

MATERIALS AND METHODS

We conducted a comprehensive literature review of relevant studies on IPF management. We searched electronic databases, including PubMed, Scopus, Embase, and Web of science.

RESULTS

The two Food and Drug Administration-approved drugs for IPF, Pirfenidone, and Nintedanib, have been pivotal in slowing disease progression, yet experimental evidence suggests that Saracatinib surpasses their efficacy. Preclinical trials investigating the potential of Saracatinib, a tyrosine kinase inhibitor, have shown to be more effective than current IPF drugs in slowing disease progression in preclinical studies. Also, Sotatercept,a fusion protein, has been shown to reduce pulmonary vascular resistance and improve exercise tolerance in patients with PH associated with IPF in clinical trials.

CONCLUSIONS

The advancements discussed in this review hold the promise of improving the quality of life for IPF patients and enhancing our understanding of this condition. There remains a need for further research to confirm the efficacy and safety of new IPF treatments and to develop more effective strategies for managing exacerbations.

JTE-013 Alleviates Pulmonary Fibrosis by Affecting the RhoA/YAP Pathway and Mitochondrial Fusion/Fission

Pulmonary fibrosis may be due to the proliferation of fibroblasts and the aggregation of extracellular matrix, resulting in the stimulation of inflammation damage, destroying lung tissue structure, seriously affecting the patient's respiratory function, and even leading to death. We investigated the role and mechanism of JTE-013 in attenuating bleomycin (BLM)-induced pulmonary fibrosis. BLM-induced pulmonary fibrosis was established in mice. Type 2 alveolar epithelial cells (MLE-12) were stimulated with sphingosine monophosphate (S1P) in vitro. JTE-013, an S1PR2 (sphingosine 1-phosphate receptor 2) antagonist, and Verteporfin were administered in vivo and in vitro. IL-4, IL-5, TNF-α, and IFN-γ were measured by ELISA. IL-4 and IFN-γ positive cells were detected by flow cytometry. Inhibition of S1PR2 with JTE-013 significantly ameliorated BLM-induced pathological changes and inflammatory cytokine levels. JTE-013 also significantly reduced the expression of RHOA/YAP pathway proteins and mitochondrial fission protein Drp1, apoptosis, and the colocalization of α-SMA with YAP, Drp1, and Tom20, as detected by immunohistochemistry, immunofluorescence staining, TUNEL, and Western blot. In vitro, S1PR2 and YAP knockdown downregulated RHOA/YAP pathway protein expression, Drp1 phosphorylation, and Drp1 translocation, promoted YAP phosphorylation and phenotypic transformation of MFN2, and inhibited the up-regulation of mitochondrial membrane potential, reactive oxygen species production, and cell apoptosis (7.13% vs. 18.14%), protecting the integrity of the mitochondrial dynamics. JTE-013 also inhibited the expression of fibrosis markers α-SMA, MMP-9, and COL1A1, and alleviated the symptoms of pulmonary fibrosis. Conclusively, JTE-013 has great anti-pulmonary fibrosis potential by regulating RHOA/YAP and mitochondrial fusion/fission.

Circulating inflammatory cytokines and risk of idiopathic pulmonary fibrosis: a Mendelian randomization study

BACKGROUND

The previous epidemiological and experimental evidence has implied the linkage between chronic inflammation to idiopathic pulmonary fibrosis (IPF). However, it was still unclear whether there were casual associations between circulating inflammatory cytokines and IPF development. The objective of present study was to examine whether altered genetically predicted concentration of circulating cytokines were associated with IPF development using a two-sample Mendelian randomization (MR) analysis.

MATERIALS AND METHODS

The causal effects of 23 circulating inflammatory cytokines were evaluated on IPF using MR analysis. The primary approach of MR analysis was the inverse variance-weighted (IVW) method. The sensitivity analyses were conducted by simple median, weighted median, penalized weighted median and MR-Egger regression methods.

RESULTS

The present MR study found suggestive evidence that a higher circulating IL-14 level was associated with an increased risk of IPF (random effects IVW method: odds ratio: 1.001, 95% confidence interval: 1.000-1.001, P = 0.026). The sensitivity analysis yielded directionally similar results for IL-14. There was no significant association found between other circulating inflammatory cytokines and IPF.

CONCLUSION

The high level of IL14 predicted by genes had a casual relationship with the increased risk of IPF. This finding provided epidemiological evidence for drug therapy targeting inflammatory factors in the prevention and treatment of IPF. It's warranted further exploration to validate the clinical significance of IL14 associated with developmental risk of IPF.

Overexpression of KLF4 Suppresses Pulmonary Fibrosis through the HIF-1α/Endoplasmic Reticulum Stress Signaling Pathway

The hypoxia-inducible factor-1α/endoplasmic reticulum stress signaling pathway (HIF-1α/ERS) has a crucial role in the pathogenetic mechanism of pulmonary fibrosis (PF). However, the upstream regulatory mediators of this pathway remain unclear. In the present study, by conducting bioinformatics analysis, we found that Krüppel-like factor 4 (KLF4) expression was decreased in the lung tissues of patients with idiopathic pulmonary fibrosis (IPF) as compared to that in patients with non-IPF. Furthermore, KLF4 expression was significantly reduced (p = 0.0331) in bleomycin-induced fibrotic HFL-1 cells. Moreover, in mice with bleomycin-induced PF, the degree of fibrosis was significantly reduced in mice overexpressing KLF4 as compared to that in wild-type mice. In mice and HFL-1 cells, KLF4 overexpression significantly reduced bleomycin-induced protein expression of HIF-1α (p = 0.0027) and ERS markers, particularly p-IRE1α (p = 0.0255) and ATF6 (p = 0.0002). By using the JASPAR database, we predicted that KLF4 has five binding sites for the HIF-1α promoter. The results of in vitro and in vivo studies suggest that KLF4 may inhibit PF through the HIF-1α/ERS pathway. This finding could guide the development of future therapies for PF and facilitate the identification of appropriate biomarkers for routine clinical diagnosis of PF.

Genome-wide DNA methylation analysis of Astragalus and Danshen on the intervention of myofibroblast activation in idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF), a chronic progressive interstitial lung disease of unknown etiology, is characterized by continuous damage to alveolar epithelial cells, abnormal repair of alveolar tissue, and alveolar wall scar formation. Currently, the recommended treatment for IPF in Western medicine is relatively limited. In contrast, traditional Chinese medicine and compound prescriptions show advantages in the diagnosis and treatment of IPF, which can be attributed to their multi-channel and multi-target characteristics and minimal side-effects. The purpose of this study was to further corroborate the effectiveness and significance of the traditional Chinese medications Astragalus and Danshen in IPF treatment.

METHODS

We performed whole-genome methylation analysis on nine rat lung tissue samples to determine the epigenetic variation between IPF and non-fibrotic lungs using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses and quantitative reverse transcription polymerase chain reactions.

RESULTS

We identified differentially methylated regions and 105 associated key functional genes in samples related to IPF and Chinese medicine treatment. Based on the methylation levels and gene expression profiles between the Chinese medicine intervention and pulmonary fibrosis model groups, we speculated that Astragalus and Salvia miltiorrhiza (traditionally known as Danshen) act on the Isl1, forkhead box O3, and Sonic hedgehog genes via regulation at transcriptional and epigenetic levels during IPF.

CONCLUSIONS

These findings provide novel insights into the epigenetic regulation of IPF, indicate the effectiveness of Astragalus and Danshen in treating IPF, and suggest several promising therapeutic targets for preventing and treating IPF.

Underlying Molecular Mechanism and Construction of a miRNA-Gene Network in Idiopathic Pulmonary Fibrosis by Bioinformatics

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease, but its pathogenesis is still unclear. Bioinformatics methods were used to explore the differentially expressed genes (DEGs) and to elucidate the pathogenesis of IPF at the genetic level. The microarray datasets GSE110147 and GSE53845 were downloaded from the Gene Expression Omnibus (GEO) database and analyzed using GEO2R to obtain the DEGs. The DEGs were further analyzed for Gene Ontology (GO) and Kyoto Encyclopedia of Genomes (KEGG) pathway enrichment using the DAVID database. Then, using the STRING database and Cytoscape, a protein-protein interaction (PPI) network was created and the hub genes were selected. In addition, lung tissue from a mouse model was validated. Lastly, the network between the target microRNAs (miRNAs) and the hub genes was constructed with NetworkAnalyst. A summary of 240 genes were identified as DEGs, and functional analysis highlighted their role in cell adhesion molecules and ECM-receptor interactions in IPF. In addition, eight hub genes were selected. Four of these hub genes (VCAM1, CDH2, SPP1, and POSTN) were screened for animal validation. The IHC and RT-qPCR of lung tissue from a mouse model confirmed the results above. Then, miR-181b-5p, miR-4262, and miR-155-5p were predicted as possible key miRNAs. Eight hub genes may play a key role in the development of IPF. Four of the hub genes were validated in animal experiments. MiR-181b-5p, miR-4262, and miR-155-5p may be involved in the pathophysiological processes of IPF by interacting with hub genes.

Prognostic Value of Serum Biomarkers in Patients with Idiopathic Pulmonary Fibrosis in Relation to Disease Progression

BACKGROUND

The aim of this present study was to determine serum biomarker levels and their correlation with respiratory function and the clinical course of patients with idiopathic pulmonary fibrosis (IPF).

MATERIALS AND METHODS

This study included 72 IPF patients, according to the ATS/ERS criteria, in whom antifibrotic treatment was initiated. Blood samples were taken, and serum biomarkers, such as KL-6, SP-D, CCL18, CXCL13, VEGF-A, IL-8, IGFBP-1, IGFBP-2, IGFBP-7 and ICAM-1 were measured using ELISA methodology. Pulmonary function tests (FVC, TLC, DLCO-% pred) were determined at baseline and after 12 and 24 months and analyzed in correlation with the biomarkers.

RESULTS

The majority of patients (mean age 72 ± 6 years) were men (83%). The FVC and DLCO values at the 12-month follow-up were found to be statistically decreased in deceased patients (p < 0.05). The SP-D (p < 0.001) and the IGFBP-1 (p = 0.021) levels were found to be increased at the 1-year follow-up in deceased patients, and similarly, the SP-D (p = 0.005) and ICAM-1 (p = 0.043) levels at the 2-year follow-up. A chi-square test revealed that 70% of the category IV GAP index was found with cut-off elevated levels of a biomarker combination (KL-6, SP-D, VEGF-A) from the ROC curve analysis (p < 0.05).

CONCLUSION

This study provides evidence, for the first time in a Greek population, of the possibility of using a combination of KL-6, SP-D, and VEGF-A serum levels along with the GAP index.

Angiotensin I-Converting Enzyme Inhibitory Activity of Two Peptides Derived from In Vitro Digestion Products of Pork Sausage with Partial Substitution of NaCl by KCl

This study aimed to identify angiotensin I-converting enzyme (ACE) from in vitro digestion products of pork sausage with partial substitution of NaCl by KCl (PSRK). Peptides from in vitro digestion products of PSRK were identified through liquid chromatography with tandem mass spectrometry analysis coupled with de novo sequencing. Subsequently, the ACE inhibitory peptides LIVGFPAYGH and IVGFPAYGH were screened based on PeptideRanker, in silico absorption, molecular docking, and the determination of ACE inhibitory activity. In addition, the ACE inhibitory peptides LIVGFPAYGH and IVGFPAYGH were mixed-type inhibitors; these peptides' ACE inhibitory activities were expressed as the 50% inhibitory concentration (IC₅₀) values in vitro, which were 196.16 and 150.88 μM, respectively. After 2 h of incubation, LIVGFPAYGH and IVGFPAYGH could be transported through Caco-2 cell monolayers with paracellular passive diffusion. Furthermore, LIVGFPAYGH and IVGFPAYGH significantly increased the levels of ACE2 and nitric oxide while decreasing the levels of ACE, angiotensin II, and endothelin-1 in Ang I-treated human umbilical vein endothelial cells, indicating the ACE inhibitory effect of LIVGFPAYGH and IVGFPAYGH. In summary, LIVGFPAYGH and IVGFPAYGH from PSRK can be used as functional foods with antihypertensive activity.

Changes in patient-reported outcomes in patients with non-idiopathic pulmonary fibrosis fibrotic interstitial lung disease and progressive pulmonary fibrosis

Background

Health-related quality of life (HRQoL) captures different aspects of the fibrotic interstitial lung disease (FILD) evaluation from the patient's perspective. However, little is known about how HRQoL changes in patients with non-idiopathic pulmonary fibrosis (IPF) FILD, especially in those with progressive pulmonary fibrosis (PPF). The aim of this study is to clarify whether HRQoL deteriorates in patients with non-IPF FILD and to evaluate the differences in the changes in HRQoL between those with and without PPF.

Methods

We collected data from consecutive patients with non-IPF FILD and compared annual changes in HRQoL over 2 years between patients with PPF and those without. The St George's respiratory questionnaire (SGRQ) and COPD assessment test (CAT) were used to assess HRQoL. Changes in the SGRQ and CAT scores for 24 months from baseline were evaluated with a mixed-effect model for repeated measures.

Results

A total of 396 patients with non-IPF FILD were reviewed. The median age was 65 years and 202 were male (51.0%). The median SGRQ and CAT scores were 29.6 and 11, respectively. Eighty-six (21.7%) showed PPF. Both SGRQ and CAT scores were significantly deteriorated in patients with PPF compared to those without PPF (p < 0.01 for both). Clinically important deterioration in the SGRQ and CAT scores were observed in 40.0 and 35.7% of patients with PPF and 11.7 and 16.7% of those without, respectively. PPF was significantly associated with clinically important deterioration in the SGRQ score (odds ratio 5.04; 95%CI, 2.61-9.76, p < 0.01) and CAT score (odds ratio 2.78; 95%CI, 1.27-6.06, p = 0.02).

Conclusion

The SGRQ and CAT scores were significantly deteriorated in patients with non-IPF FILD and PPF. Considering an evaluation of HRQoL would be needed when assessing PPF.

The Role of Erythrocyte Membrane Protein Band 4.1-like 3 in Idiopathic Pulmonary Fibrosis

Novel genetic and epigenetic factors involved in the development and prognosis of idiopathic pulmonary fibrosis (IPF) have been identified. We previously observed that erythrocyte membrane protein band 4.1-like 3 (EPB41L3) increased in the lung fibroblasts of IPF patients. Thus, we investigated the role of EPB41L3 in IPF by comparing the EPB41L3 mRNA and protein expression of lung fibroblast between patients with IPF and controls. We also investigated the regulation of epithelial-mesenchymal transition (EMT) in an epithelial cell line (A549) and fibroblast-to-myofibroblast transition (FMT) in a fibroblast cell line (MRC5) by overexpressing and silencing EPB41L3. EPB41L3 mRNA and protein levels, as measured using RT-PCR, real-time PCR, and Western blot, were significantly higher in fibroblasts derived from 14 IPF patients than in those from 10 controls. The mRNA and protein expression of EPB41L3 was upregulated during transforming growth factor-β-induced EMT and FMT. Overexpression of EPB41L3 in A549 cells using lenti-EPB41L3 transfection suppressed the mRNA and protein expression of N-cadherin and COL1A1. Treatment with EPB41L3 siRNA upregulated the mRNA and protein expression of N-cadherin. Overexpression of EPB41L3 in MRC5 cells using lenti-EPB41L3 transfection suppressed the mRNA and protein expression of fibronectin and α-SMA. Finally, treatment with EPB41L3 siRNA upregulated the mRNA and protein expression of FN1, COL1A1, and VIM. In conclusion, these data strongly support an inhibitory effect of EPB41L3 on the process of fibrosis and suggest the therapeutic potential of EPB41L3 as an anti-fibrotic mediator.

Neutrophil-Related Gene Expression Signatures in Idiopathic Pulmonary Fibrosis: Implications for Disease Characteristic and Identification of Diagnostic Hub Genes

Background

Idiopathic pulmonary fibrosis (IPF) is a disease with unclear etiology and a poor prognosis. Although the involvement of neutrophils in IPF pathogenesis has been suggested, the exact nature of this relationship remains unclear.

Methods

We analyzed data from the Gene Expression Omnibus (GEO) using immune infiltration analysis, weighted gene co-expression network analysis (WGCNA), and consensus cluster analysis. Neutrophil-related genes and hub genes related to neutrophils were identified and differentially expressed between IPF patients and healthy controls. We also validated the expression differences of hub genes in a bleomycin-induced mice model.

Results

Immune infiltration analysis revealed a significantly decreased percentage of neutrophils in the lung tissue of IPF patients compared with healthy controls (P<0.001) in both the train and validation sets. Neutrophil-related genes in IPF were identified by WGCNA, and functional enrichment analysis showed that these genes were mainly involved in the cytokine-cytokine receptor interaction pathway and correlated with lung disease, consistent with DEGs between IPF and healthy controls. Eight hub genes related to neutrophils were identified, including MMP16, ARG1, IL1R2, PROK2, MS4A2, PIR, and ZNF436. Consensus cluster analysis revealed a low neutrophil-infiltrating cluster that was correlated with IPF (P<0.001), and a principal component analysis-generated score could distinguish IPF patients from healthy controls, with an area under the curve of 0.930 in the train set and 0.768 in the validation set. We also constructed a diagnostic model using hub genes related to neutrophils, which showed a reliable diagnostic value with an area under the curve of 0.955 in the train set and 0.995 in the validation set.

Conclusion

Our findings provide evidence of a low neutrophil-infiltrating characteristic in the IPF microenvironment and identify hub genes related to neutrophils that may serve as diagnostic biomarkers for the disease.

Amelioration of Pulmonary Fibrosis by Matrix Metalloproteinase-2 Overexpression

Idiopathic pulmonary fibrosis is a progressive and fatal disease with a poor prognosis. Matrix metalloproteinase-2 is involved in the pathogenesis of organ fibrosis. The role of matrix metalloproteinase-2 in lung fibrosis is unclear. This study evaluated whether overexpression of matrix metalloproteinase-2 affects the development of pulmonary fibrosis. Lung fibrosis was induced by bleomycin in wild-type mice and transgenic mice overexpressing human matrix metalloproteinase-2. Mice expressing human matrix metalloproteinase-2 showed significantly decreased infiltration of inflammatory cells and inflammatory and fibrotic cytokines in the lungs compared to wild-type mice after induction of lung injury and fibrosis with bleomycin. The computed tomography score, Ashcroft score of fibrosis, and lung collagen deposition were significantly reduced in human matrix metalloproteinase transgenic mice compared to wild-type mice. The expression of anti-apoptotic genes was significantly increased, while caspase-3 activity was significantly reduced in the lungs of matrix metalloproteinase-2 transgenic mice compared to wild-type mice. Active matrix metalloproteinase-2 significantly decreased bleomycin-induced apoptosis in alveolar epithelial cells. Matrix metalloproteinase-2 appears to protect against pulmonary fibrosis by inhibiting apoptosis of lung epithelial cells.

Oxy210, a Semi-Synthetic Oxysterol, Inhibits Profibrotic Signaling in Cellular Models of Lung and Kidney Fibrosis

Oxy210, a semi-synthetic oxysterol derivative, displays cell-selective inhibition of Hedgehog (Hh) and transforming growth factor beta (TGF-β) signaling in epithelial cells, fibroblasts, and macrophages as well as antifibrotic and anti-inflammatory efficacy in models of liver fibrosis. In the present report, we examine the effects of Oxy210 in cellular models of lung and kidney fibrosis, such as human lung fibroblast cell lines IMR-90, derived from healthy lung tissue, and LL97A, derived from an idiopathic pulmonary fibrosis (IPF) patient. In addition, we examine the effects of Oxy210 in primary human renal fibroblasts, pericytes, mesangial cells, and renal tubular epithelial cells, known for their involvement in chronic kidney disease (CKD) and kidney fibrosis. We demonstrate in fibroblasts that the expression of several profibrotic TGF-β target genes, including fibronectin (FN), collagen 1A1 (COL1A1), and connective tissue growth factor (CTGF) are inhibited by Oxy210, both at the basal level and following TGF-β stimulation in a statistically significant manner. The inhibition of COL1A1 gene expression translated directly to significantly reduced COL1A1 protein expression. In human primary small airway epithelial cells (HSAECs) and renal tubular epithelial cells, Oxy210 significantly inhibited TGF-β target gene expression associated with epithelial-mesenchymal transition (EMT). Oxy210 also inhibited the proliferation of fibroblasts, pericytes, and mesangial cells in a dose-dependent and statistically significant manner.

Identification of diagnostic gene biomarkers related to immune infiltration in patients with idiopathic pulmonary fibrosis based on bioinformatics strategies

Objective

The study aims to identify potential diagnostic markers of idiopathic pulmonary fibrosis (IPF) and analyze the significance of immune cell infiltration in this pathology.

Materials and methods

Download two publicly available gene expression profiles (GSE10667 and GSE24206 datasets) from the GEO database including 48 Idiopathic pulmonary fibrosis (IPF) samples and 21 human control samples and select for distinctly expressed genes (DEG) from them. Lasso regression model and support vector machine recursive feature elimination S,V,R,F analysis were used to check candidate biomarkers. The area under the subject's work characteristic curve (AUC) value is used to evaluate its recognition ability. The GSE53845 dataset (40 IPF patients and 8 controls) continue to validate the expression level and diagnostic value of biomarkers in IPF. Comprehensive analysis of immune infiltrated cells of IPF was performed using R software and immune cell infiltration estimation analysis tool- deconvolution algorithm (CIBERSORT).

Results

43 DEGs were identified in total. The identified DEGs mostly involve pneumonia, lung disease, collagen disease, obstructive pulmonary disease and other diseases. The activation of IL-17 signaling pathways, amoebic disease, interaction of viral proteins with cytokines and cytokine receptors, protein digestion and absorption, and flaccid hormone signaling pathways in IPF were different from the control group. The expression degree of CRTAC1, COL10A1, COMP, RPS4Y1, IGFL2, NECAB1, SCG5, SLC6A4, and SPP1 in IPF tissue were prominently higher than the normal group. Immune cell infiltration analysis showed that CRTAC1, COL10A1, COMP, IGFL2, NECAB1, SCG5, SLC6A4, and SPP1 were associated with monocytes, plasma cells, neutrophils, and regulatory (treg) T cells.

Conclusion

CRTAC1, COL10A1, COMP, IGFL2, NECAB1, SCG5, SLC6A4, and SPP1 can be used as diagnostic markers for IPF, providing new ideas for the future study of IPF occurrence and molecular mechanisms.

Genetics in Idiopathic Pulmonary Fibrosis: A Clinical Perspective

BACKGROUND

Unraveling the genetic background in a significant proportion of patients with both sporadic and familial IPF provided new insights into the pathogenic pathways of pulmonary fibrosis.

AIM

The aim of the present study is to overview the clinical significance of genetics in IPF.

PERSPECTIVE

It is fascinating to realize the so-far underestimated but dynamically increasing impact that genetics has on aspects related to the pathophysiology, accurate and early diagnosis, and treatment and prevention of this devastating disease. Genetics in IPF have contributed as no other in unchaining the disease from the dogma of a "a sporadic entity of the elderly, limited to the lungs" and allowed all scientists, but mostly clinicians, all over the world to consider its many aspects and "faces" in all age groups, including its co-existence with several extra pulmonary conditions from cutaneous albinism to bone-marrow and liver failure.

CONCLUSION

By providing additional evidence for unsuspected characteristics such as immunodeficiency, impaired mucus, and surfactant and telomere maintenance that very often co-exist through the interaction of common and rare genetic variants in the same patient, genetics have created a generous and pluralistic yet unifying platform that could lead to the understanding of the injurious and pro-fibrotic effects of many seemingly unrelated extrinsic and intrinsic offending factors. The same platform constantly instructs us about our limitations as well as about the heritability, the knowledge and the wisdom that is still missing.

Gastroesophageal Reflux Disease in Idiopathic Pulmonary Fibrosis: Viewer or Actor? To Treat or Not to Treat?

Background: Idiopathic pulmonary fibrosis (IPF) is a rare and severe disease with a median survival of ∼3 years. Several risk factors have been identified, such as age, genetic predisposition, tobacco exposure, and gastro-oesophageal reflux disease (GERD). Prevalence of GERD in IPF is high and may affect 87% of patients, of whom only half (47%) report symptoms. Objective: The aim of this study is to review current evidence regarding the correlation between GERD and IPF and to evaluate the current studies regarding treatments for GERD-IPF. Methods: A review to identify research papers documenting an association between GERD and IPF was performed. Results: We identified several studies that have confirmed the association between GERD and IPF, with an increased acid exposure, risk of gastric aspiration and bile acids levels in these patients. Few studies focused their attention on GERD treatment, showing how antiacid therapy was not able to change IPF evolution. Conclusions: This review investigating the correlation between GERD and IPF has confirmed the hypothesized association. However, further large prospective studies are needed to corroborate and elucidate these findings with a focus on preventative and treatment strategies.

Chronic Thromboembolic Pulmonary Hypertension: An Observational Study

Background and Objectives: Chronic thromboembolic pulmonary hypertension (CTEPH) has a high mortality. The treatment of CTEPH could be balloon pulmonary angioplasty (BPA), medical (MT) or pulmonary endarterectomy (PEA). This study aims to assess the clinical characteristics of CTEPH patients, surgically or medically treated, in a pulmonology referral center. Materials and Methods: A total of 124 patients with PH with suspected CTEPH (53 male subjects and 71 female subjects; mean age at diagnosis 67 ± 6) were asked to give informed consent and then were evaluated. The presence of CTEPH was ascertained by medical evaluations, radiology and laboratory tests. Results: After the evaluation of all clinical data, 65 patients met the inclusion criteria for CTEPH and they were therefore enrolled (22 males and 43 females; mean age at diagnosis was 69 ± 8). 26 CTEPH patients were treated with PEA, 32 with MT and 7 with BPA. There was a statistically significant age difference between the PEA and MT groups, at the time of diagnosis, the PEA patients were younger than the MT patients, whereas there was no statistically significant difference in other clinical characteristics (e.g., smoking habit, thrombophilia predisposition), as well as functional and hemodynamic parameters (e.g., 6-min walk test, right heart catheterization). During three years of follow-up, no patients in the PEA groups died; conversely, eleven patients in the MT group died during the same period (p < 0.05). Furthermore, a significant decrease in plasma BNP values and an increase in a meter at the six-minute walk test, 1 and 3 years after surgery, were observed in the PEA group (p < 0.05). Conclusions: This study seems to confirm that pulmonary endarterectomy (PEA) can provide an improvement in functional tests in CTEPH.

Research Progress in the Molecular Mechanisms, Therapeutic Targets, and Drug Development of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease. Recent studies have identified the key role of crosstalk between dysregulated epithelial cells, mesenchymal, immune, and endothelial cells in IPF. In addition, genetic mutations and environmental factors (e.g., smoking) have also been associated with the development of IPF. With the recent development of sequencing technology, epigenetics, as an intermediate link between gene expression and environmental impacts, has also been reported to be implicated in pulmonary fibrosis. Although the etiology of IPF is unknown, many novel therapeutic targets and agents have emerged from clinical trials for IPF treatment in the past years, and the successful launch of pirfenidone and nintedanib has demonstrated the promising future of anti-IPF therapy. Therefore, we aimed to gain an in-depth understanding of the underlying molecular mechanisms and pathogenic factors of IPF, which would be helpful for the diagnosis of IPF, the development of anti-fibrotic drugs, and improving the prognosis of patients with IPF. In this study, we summarized the pathogenic mechanism, therapeutic targets and clinical trials from the perspective of multiple cell types, gene mutations, epigenetic and environmental factors.

Zoledronic Acid Targeting of the Mevalonate Pathway Causes Reduced Cell Recruitment and Attenuates Pulmonary Fibrosis

Background and aim: Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease causing irreparable scarring of lung tissue, with most patients succumbing rapidly after diagnosis. The mevalonate pathway, which is involved in the regulation of cell proliferation, survival, and motility, is targeted by the bisphosphonate zoledronic acid (ZA). The aim of this study was to assess the antifibrotic effects of ZA and to elucidate the mechanisms by which potential IPF treatment occurs.

Methods: A series of in vitro and in vivo models were employed to identify the therapeutic potential of ZA in treating IPF. In vitro transwell assays were used to assess the ability of ZA to reduce fibrotic-related immune cell recruitment. Farnesyl diphosphate synthase (FDPS) was screened as a potential antifibrotic target using a bleomycin mouse model. FDPS-targeting siRNA and ZA were administered to mice following the onset of experimentally-induced lung fibrosis. Downstream analyses were conducted on murine lung tissues and lung fluids including 23-plex cytokine array, flow cytometry, histology, Western blotting, immunofluorescent staining, and PCR analysis.

Results:In vitro administration of ZA reduced myofibroblast transition and blocked NF-κB signaling in macrophages leading to impaired immune cell recruitment in a transwell assay. FDPS-targeting siRNA administration significantly attenuated profibrotic cytokine production and lung damage in a murine lung fibrosis model. Furthermore, ZA treatment of mice with bleomycin-induced lung damage displayed decreased cytokine levels in the BALF, plasma, and lung tissue, resulting in less histologically visible fibrotic scarring. Bleomycin-induced upregulation of the ZA target, FDPS, was reduced in lung tissue and fibroblasts upon ZA treatment. Confirmatory increases in FDPS immunoreactivity was seen in human IPF resected lung samples compared to control tissue indicating potential translational value of the approach. Additionally, ZA polarized macrophages towards a less profibrotic phenotype contributing to decreased IPF pathogenesis.

Conclusion: This study highlights ZA as an expedient and efficacious treatment option against IPF in a clinical setting.

Targeting Growth Factor and Cytokine Pathways to Treat Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease of unknown origin that usually results in death from secondary respiratory failure within 2–5 years of diagnosis. Recent studies have identified key roles of cytokine and growth factor pathways in the pathogenesis of IPF. Although there have been numerous clinical trials of drugs investigating their efficacy in the treatment of IPF, only Pirfenidone and Nintedanib have been approved by the FDA. However, they have some major limitations, such as insufficient efficacy, undesired side effects and poor pharmacokinetic properties. To give more insights into the discovery of potential targets for the treatment of IPF, this review provides an overview of cytokines, growth factors and their signaling pathways in IPF, which have important implications for fully exploiting the therapeutic potential of targeting cytokine and growth factor pathways. Advances in the field of cytokine and growth factor pathways will help slow disease progression, prolong life, and improve the quality of life for IPF patients in the future.

Changes in Thoracic Cavity Volume After Bilateral Lung Transplantation

Purpose

End-stage lung diseases result in anatomical changes of the thoracic cavity. However, very few studies have assessed changes in the thoracic cavity after lung transplantation (LTx). This study aimed to evaluate the relationships between thoracic cavity volume (TCV) changes after LTx and underlying lung disease.

Methods

We reviewed 89 patients who underwent a pre-LTx pulmonary function test (PFT), chest computed tomography (CT) scan, and 1-year follow-up CT after LTx. These patients were classified into two groups according to pre-LTx PFT as follows: obstructive group [forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio < 70%] and restrictive group (FEV1/FVC ratio > 70%). We measured TCV using CT scan before and at 1 year after LTx and compared the TCV change in the two groups.

Results

In the restrictive group, TCV increased after LTx (preop: 2,347.8 ± 709.5 mL, 1-year postop: 3,224.4 ± 919.0 mL, p < 0.001). In contrast, in the obstructive group, it decreased after LTx (preop: 4,662.9 ± 1,296.3 mL, 1-year postop: 3,711.1 ± 891.7 mL, p < 0.001). We observed that restrictive lung disease, taller stature, lower body mass index, and larger donor lung were independently associated with increased TCV after LTx.

Conclusion

The disease-specific chest remodeling caused by restriction and hyperinflation is at least, in part, reversible. After LTx, the chest remodeling appears to occur in the opposite direction to the disease-specific remodeling caused by the underlying lung disease in recipients.

Catalpol Attenuates Pulmonary Fibrosis by Inhibiting Ang II/AT1 and TGF-β/Smad-Mediated Epithelial Mesenchymal Transition

Background

Idiopathic pulmonary fibrosis (IPF) is a progressive and devastating chronic lung condition affecting over 3 million people worldwide with a high mortality rate and there are no effective drugs. Angiotensin II (Ang II), as a major effector peptide of the renin angiotensin aldosterone system, has been shown to act in tandem with the transforming growth factor-β (TGF-β) signaling pathway to promote the infiltration of inflammatory cells, production of reactive oxygen species (ROS) and profibrotic factors after lung injury, and to participate in the process of epithelial mesenchymal transition (EMT). Catalpol (CAT) has been shown to have anti-inflammatory and antifibrotic effects. However, the effects and mechanisms of CAT on pulmonary fibrosis are not clear.

Purpose

To assess the effects and mechanisms of catalpol on bleomycin-induced pulmonary fibrosis in mice.

Methods

We used bleomycin-induced mouse model of pulmonary fibrosis to evaluate the alleviation effect of CAT at 7, 14, 28d, respectively. Next, enzyme-linked immunosorbent assay, hematoxylin-eosin staining, immunofluorescence, Masson trichrome staining and western blotting were used to study the underlying mechanism of CAT on bleomycin-induced pulmonary fibrosis.

Results

It's demonstrated that CAT exerted a potent anti-fibrotic function in BLM-induced mice pulmonary fibrosis via alleviating inflammatory, ameliorating collagen deposition, reducing the level of Ang II and HYP and alleviating the degree of EMT. Moreover, CAT attenuate BLM-induced fibrosis by targeting Ang II/AT₁ and TGF-β/Smad signaling in vivo.

Conclusion

CAT may serve as a novel therapeutic candidate for the simultaneous blockade of Ang II and TGF-β pathway to attenuate pulmonary fibrosis.

Glutamine Metabolism Is Required for Alveolar Regeneration during Lung Injury

(1) Background: Abnormal repair after alveolar epithelial injury drives the progression of idiopathic pulmonary fibrosis (IPF). The maintenance of epithelial integrity is based on the self-renewal and differentiation of alveolar type 2 (AT2) cells, which require sufficient energy. However, the role of glutamine metabolism in the maintenance of the alveolar epithelium remains unclear. In this study, we investigated the role of glutamine metabolism in AT2 cells of patients with IPF and in mice with bleomycin-induced fibrosis. (2) Methods: Single-cell RNA sequencing (scRNA-seq), transcriptome, and metabolomics analyses were conducted to investigate the changes in the glutamine metabolic pathway during pulmonary fibrosis. Metabolic inhibitors were used to stimulate AT2 cells to block glutamine metabolism. Regeneration of AT2 cells was detected using bleomycin-induced mouse lung fibrosis and organoid models. (3) Results: Single-cell analysis showed that the expression levels of catalytic enzymes responsible for glutamine catabolism were downregulated (p < 0.001) in AT2 cells of patients with IPF, suggesting the accumulation of unusable glutamine. Combined analysis of the transcriptome (p < 0.05) and metabolome (p < 0.001) revealed similar changes in glutamine metabolism in bleomycin-induced pulmonary fibrosis in mice. Mechanistically, inhibition of the key enzymes involved in glucose metabolism, glutaminase-1 (GLS1) and glutamic-pyruvate transaminase-2 (GPT2) leads to reduced proliferation (p < 0.01) and differentiation (p < 0.01) of AT2 cells. (4) Conclusions: Glutamine metabolism is required for alveolar epithelial regeneration during lung injury.

An Overview of Different Techniques for Improving the Treatment of Pulmonary Hypertension Secondary in Systemic Sclerosis Patients

In systemic sclerosis (SSc) mortality is mainly linked to lung involvement which is characterized by interstitial lung disease (ILD) and pulmonary hypertension (PH). In SSc, PH may be due to different etiologies, including ILD, chronic thromboembolic disease, pulmonary veno-occlusive disease, and pulmonary arterial hypertension (PAH). The main tool to screen PAH is transthoracic echocardiography (TTE), which has a sensitivity of 90%, even if definitive diagnosis should be confirmed by right heart catheterization (RHC). The radiological evaluation (i.e., HRTC) plays an important role in defining the possible causes and in monitoring the evolution of lung damage. For PAH, identifying individuals who have borderline elevation of pulmonary arterial pressure needs to be appropriately managed and followed. In the past few years, the strategy for the management of PAH has significantly evolved and new trials are underway to test other therapies. This review provides an overview of the tools to evaluate PAH in SSc patients and on treatment options for these patients.

Discrimination between NSIP- and IPF-Derived Fibroblasts Based on Multi-Parameter Characterization of Their Growth, Morphology and Physic-Chemical Properties

Background: The aim of the research presented here was to find a set of parameters enabling discrimination between three types of fibroblasts, i.e., healthy ones and those derived from two disorders mimicking each other: idiopathic pulmonary fibrosis (IPF), and nonspecific interstitial pneumonia (NSIP). Methods: The morphology and growth of cells were traced using fluorescence microscopy and analyzed quantitatively using cell proliferation and substrate cytotoxicity indices. The viability of cells was recorded using MTS assays, and their stiffness was examined using atomic force microscopy (AFM) working in force spectroscopy (FS) mode. To enhance any possible difference in the examined parameters, experiments were performed with cells cultured on substrates of different elasticities. Moreover, the chemical composition of cells was determined using time-of-flight secondary ion mass spectrometry (ToF-SIMS), combined with sophisticated analytical tools, i.e., Multivariate Curve Resolution (MCR) and Principal Component Analysis (PCA). Results: The obtained results demonstrate that discrimination between cell lines derived from healthy and diseased patients is possible based on the analysis of the growth of cells, as well as their physical and chemical properties. In turn, the comparative analysis of the cellular response to altered stiffness of the substrates enables the identification of each cell line, including distinguishing between IPF- and NSIP-derived fibroblasts.

High-Resolution Computed Tomography and Lung Ultrasound in Patients with Systemic Sclerosis: Which One to Choose?

Imaging plays a pivotal role in systemic sclerosis for both diagnosis management of pulmonary complications, and high-resolution computed tomography (HRCT) is the most sensitive technique for the evaluation of systemic sclerosis-associated interstitial lung disease (SSc-ILD). Indeed, several studies have demonstrated that HRCT helps radiologists and clinicians to make a correct diagnosis on the basis of recognised typical patterns for SSc-ILD. Most SSc patients affected by ILD have a non-specific interstitial pneumonia pattern (NISP) on HRCT scan, whilst a minority of cases fulfil the criteria for usual interstitial pneumonia (UIP). Moreover, several recent studies have demonstrated that lung ultrasound (LUS) is an emergent tool in SSc diagnosis and follow-up, although its role is still to be confirmed. Therefore, this article aims at evaluating the role of LUS in SSc screening, aimed at limiting the use of CT to selected cases.

Telomere Dysfunction in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis is an age-dependent progressive and fatal lung disease of unknown etiology, which is characterized by the excessive accumulation of extracellular matrix inside the interstitial layer of the lung parenchyma that leads to abnormal scar architecture and compromised lung function capacity. Recent genetic studies have attributed the pathological genes or genetic mutations associated with familial idiopathic pulmonary fibrosis (IPF) and sporadic IPF to telomere-related components, suggesting that telomere dysfunction is an important determinant of this disease. In this study, we summarized recent advances in our understanding of how telomere dysfunction drives IPF genesis. We highlighted the key role of alveolar stem cell dysfunction caused by telomere shortening or telomere uncapping, which bridged the gap between telomere abnormalities and fibrotic lung pathology. We emphasized that senescence-associated secretory phenotypes, innate immune cell infiltration, and/or inflammation downstream of lung stem cell dysfunction influenced the native microenvironment and local cell signals, including increased transforming growth factor-beta (TGF-β) signaling in the lung, to induce pro-fibrotic conditions. In addition, the failed regeneration of new alveoli due to alveolar stem cell dysfunction might expose lung cells to elevated mechanical tension, which could activate the TGF-β signaling loop to promote the fibrotic process, especially in a periphery-to-center pattern as seen in IPF patients. Understanding the telomere-related molecular and pathophysiological mechanisms of IPF would provide new insights into IPF etiology and therapeutic strategies for this fatal disease.

Lung Tissue Microbiome Is Associated With Clinical Outcomes of Idiopathic Pulmonary Fibrosis

Background: Several studies using bronchoalveolar lavage fluid (BALF) reported that lung microbial communities were associated with the development and clinical outcome of idiopathic pulmonary fibrosis (IPF). However, the microbial communities in IPF lung tissues are not well known. This study is aimed to investigate bacterial microbial communities in lung tissues and determine their impact on the clinical outcomes of patients with IPF. Methods: Genomic DNA extracted from lung tissues of patients with IPF (n = 20; 10 non-survivors) and age- and sex-matched controls (n = 20) was amplified using fusion primers targeting the V3 and V4 regions of the 16S RNA genes with indexing barcodes. Results: Mean age of IPF subjects was 63.3 yr, and 65% were male. Alpha diversity indices did not significantly differ between IPF patients and controls, or between IPF non-survivors and survivors. The relative abundance of Lactobacillus, Paracoccus, and Akkermansia was increased, whereas that of Caulobacter, Azonexus, and Undibacterium decreased in patients with IPF compared with that in the controls. A decreased relative abundance of Pelomonas (odds ratio [OR], 0.352, p = 0.027) and Azonexus (OR, 0.013, p = 0.046) was associated with a diagnosis of IPF in the multivariable logistic analysis adjusted by age and gender. Multivariable Cox analysis adjusted for age and forced vital capacity (FVC) revealed that higher relative abundance of Streptococcus (hazard ratio [HR], 1.993, p = 0.044), Sphingomonas (HR, 57.590, p = 0.024), and Clostridium (HR, 37.189, p = 0.038) was independently associated with IPF mortality. The relative abundance of Curvibacter (r = 0.590) and Thioprofundum (r = 0.373) was correlated positively, whereas that of Anoxybacillus (r = -0.509) and Enterococcus (r = -0.593) was correlated inversely with FVC. In addition, the relative abundance of the Aquabacterium (r = 0.616) and Peptoniphilus (r = 0.606) genera was positively correlated, whereas that of the Fusobacterium (r = -0.464) and Phycicoccus (r = -0.495) genera was inversely correlated with distance during the 6-min walking test. Conclusions: The composition of the microbiome in lung tissues differed between patients with IPF and controls and was associated with the diagnosis, mortality, and disease severity of IPF.

Cabozantinib ameliorates lipopolysaccharide-induced lung inflammation and bleomycin--induced early pulmonary fibrosis in mice

The lung, as the primary organ for gas exchange in mammals, is the main target organ for many pathogens and allergens, which may cause acute lung injury. A certain proportion of acute lung injury may progress into irreversible pulmonary fibrosis. Both acute lung injury and pulmonary fibrosis have high mortality rates and few effective treatments. Cabozantinib is a multi-target small molecule tyrosine kinase inhibitor and has been approved for the treatment of multiple malignant solid tumors. In this study, we explored the role of cabozantinib in acute lung injury and pulmonary fibrosis in vivo and in vitro. In the lipopolysaccharide and bleomycin induced mouse lung injury models, cabozantinib significantly improved the pathological state and reduced the infiltration of inflammatory cells in the lung tissues. In the bleomycin induced pulmonary fibrosis model, cabozantinib significantly reduced the area of pulmonary fibrosis and improved lung function in mice. The results of in vitro studies showed that cabozantinib could inhibit the inflammatory response and apoptosis of alveolar epithelial cells by inhibiting the activation of TLR4/NF-κB and NLRP3 inflammasome pathways. At the same time, cabozantinib could inhibit the activation of lung fibroblasts through suppressing the TGF-β1/Smad pathway, and promote the apoptosis of fibroblasts. In summary, cabozantinib could alleviate lung injury through regulating the TLR4 /NF-κB/NLRP3 inflammasome pathway, and alleviate pulmonary fibrosis by inhibiting the TGF-β1/Smad3 signaling pathway.

High-Resolution Computed Tomography: Lights and Shadows in Improving Care for SSc-ILD Patients

The diagnosis and classification of systemic sclerosis-associated interstitial lung disease (SSc-ILD) is essential to improve the prognosis of systemic sclerosis (SSc) patients. The risk-stratification of disease severity and follow-up requires a multidisciplinary approach, integrating high-resolution computed tomography (HRTC) of the lung, pulmonary function tests (PFT), along with clinical and symptomatic evaluations. The use of HRCT in detecting SSc-ILD is not so much based on a definitive validation, but rather reflects the widespread clinician recognition of dissatisfaction with other modalities. However, due to the heterogeneity of SSc-ILD and the potential absence of symptoms in early or mild disease, it is prudent to consider as many parameters as possible in the assessment and monitoring of newly diagnosed patients. An early diagnosis meets the primary goal, i.e., the prevention of disease progression. The current first line treatment regimens are mainly centered on immunosuppressive therapy. This review assesses the role HRCT plays in optimizing care and improving clinical outcomes in SSc-ILD patients.

Pre-existing interstitial lung disease in patients with coronavirus disease 2019: A meta-analysis

Background

The impact of pre-existing interstitial lung disease (ILD) on the severity and mortality of COVID-19 remains largely unknown. The purpose of this meta-analysis was to investigate the prevalence of ILD among patients with COVID-19 and figure out the relationship between ILD and the poor clinical outcomes of COVID-19.

Methods

A systematic literature search was conducted in the PubMed, EMBASE, Web of Science and MedRxiv Database from 1 January 2020 to 26 May 2021.

Results

15 studies with 135,263 COVID-19 patients were included for analysis of ILD prevalence. The pooled prevalence of comorbid ILD in patients with COVID-19 was 1.4% (95% CI, 1.1%-1.8%, I² = 91%) with significant between-study heterogeneity. Moreover, the prevalence of ILD in non-survival patients with COVID-19 was 2.728-folds higher than that in corresponding survival patients (RR = 2.728, 95% CI 1.162–6.408, I² = 54%, p = 0.021). Additionally, 2–3 studies were included for comparison analysis of clinical outcome between COVID-19 patients with and without ILD. The results showed that the mortality of COVID-19 patients with ILD was remarkably elevated compared with patients without ILD (RR = 2.454, 95% CI 1.111–5.421, I² = 87%, p = 0.026). Meanwhile, the pooled RR of ICU admission for ILD vs. non-ILD cases with COVID-19 was 3.064 (95% CI 1.889–4.972, I² = 0, p < 0.0001). No significant difference in utilizing rate of mechanical ventilation was observed between COVID-19 patients with and without ILD.

Conclusions

There is great variability in ILD prevalence among patients with COVID-19 across the globe. Pre-existing ILD is associated with higher severity and mortality of COVID-19.

Interstitial Lung Disease at High Resolution CT after SARS-CoV-2-Related Acute Respiratory Distress Syndrome According to Pulmonary Segmental Anatomy

Background: The purpose of this study was to evaluate High-Resolution CT (HRCT) findings in SARS-CoV-2-related ARDS survivors treated with prolonged low-dose methylprednisolone after hospital discharge. Methods: A total of 44 consecutive patients (M: 32, F: 12, average age: 64), hospitalised in our department from April to September 2020 for SARS-CoV-2-related ARDS, who had a postdischarge CT scan, were enrolled into this retrospective study. We reviewed the electronic medical charts to collect laboratory, clinical, and demographic data. The CT findings were evaluated and classified according to lung segmental distribution. The imaging findings were correlated with spirometry results and included ground glass opacities (GGOs), consolidations, reticulations, bronchiectasis/bronchiolectasis, linear bands, and loss of pulmonary volume. Results: Alterations in the pulmonary parenchyma were observed in 97.7% of patients at HRCT (median time lapse between ARDS diagnosis and HRCT: 2.8 months, range 0.9 to 6.7). The most common findings were linear bands (84%), followed by GGOs (75%), reticulations (34%), bronchiolectasis (32%), consolidations (30%), bronchiectasis (30%) and volume loss (25%). They had a symmetric distribution, and both lower lobes were the most affected areas. Conclusions: A reticular pattern with a posterior distribution was observed 3 months after discharge from severe COVID-19 pneumonia, and this differs from previously described postCOVID-19 fibrotic-like changes. We hypothesized that the systematic use of prolonged low-dose of corticosteroid could be the main reason of this different CT scan appearance.

Recognition of Connective Tissue Disease-Related Interstitial Pneumonia Based on Histological Score-A Validation Study of an Online Diagnostic Decision Support Tool

Objectives: to evaluate the number of cases of idiopathic pulmonary fibrosis (IPF) that included histological features of connective tissue disease (CTD) and to check whether they demonstrated the clinical features of CTD, using a previously reported CTD-interstitial pneumonia (IP) index that histologically differentiates CTD-associated and idiopathic IP. Methods: patients diagnosed with IPF following video-assisted thoracoscopic biopsy through multidisciplinary team diagnosis between 2014 and 2017 were selected. Pathological observation was made by four pathologists who scored eight observational items needed for the CTD-IP index. Cases determined as CTD, by the CTD-IP index, were extracted, and their clinical features were compared. Results: a total of 94 cases of IPF were identified, of which 20 were classified into the CTD group using the CTD-IP index with reasonable interobserver agreement (k = 0.76). Cases pathologically classified into the CTD group were significantly associated with female sex, non-smoking history, autoantibody positivity, and CTD symptoms (p = 0.01, 0.03, 0.01, and 0.04, respectively). Conclusions: patients with IPF with pathological findings of CTD showed clinical characteristics similar to those of patients with CTD.