Idiopathic Pulmonary Fibrosis
Potential role of SIRT-1 and SIRT-3 as biomarkers for the diagnosis and prognosis of idiopathic pulmonary fibrosis
Respir Res. 2024 Apr 27;25(1):189. doi: 10.1186/s12931-024-02796-0.
ABSTRACT
BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a debilitating and progressive lung disease of unknown aetiology, characterized by the relentless deposition of fibrotic tissue. Biomarkers may play a pivotal role as indicators of disease presence, progression, and treatment response. Sirtuins, a family of enzymes with ADP ribosyltransferase or deacetylase activity, have been implicated in several diseases, including pulmonary fibrosis.
METHODS: A cross-sectional, prospective, observational single-center study was conducted to investigate the potential role of serum SIRTs levels as biomarkers in patients with IPF. Demographic, clinical, and functional data and serological samples were collected from 34 patients with IPF followed at the Interstital Lung and Rare Diseases Outpatient Clinic of the Vanvitelli Pneumology Clinic, Monaldi Hospital, Naples, Italy and from 19 age-matched controls.
RESULTS: Serum SIRT-1 levels were significantly reduced in IPF patients compared to controls (median IPF 667 [435-858] pg/mL versus controls 925 [794-1173] pg/mL; p < 0.001 ). In contrast, serum SIRT-3 levels were significantly increased in IPF patients compared to controls (median IPF 338 [230-500] pg/mL versus controls 154 [99.8-246] pg/mL; p < 0.001). There were no statistically significant differences in serum SIRT-6 and SIRT-7 levels between IPF and controls. In addition, we found a significant positive correlation between SIRT-1 and lung function parameters such as FEV1% (ϱ=0.417;p = 0.016), FVC% (ϱ=0.449;p = 0.009) and DLCO% (ϱ=0.393;p = 0.024), while a significant negative correlation was demonstrated between SIR-1 and GAP score, demonstrating a significant reduction in SIRT-1 in advanced Gender-Age-Physiology (GAP) stages 2-3 compared to GAP stage 1 (p = 0.008).
CONCLUSIONS: This prospective, cross-sectional study showed that SIRT-1 was associated with lung function and IPF severity and that both SIRT-1 and SIRT-3 could be considered as potential biomarkers of IPF, whereas SIRT-6 and SIRT-7 were not associated with IPF.
PMID:38678247 | DOI:10.1186/s12931-024-02796-0
Assessment of the impact of social deprivation, distance to hospital and time to diagnosis on survival in Idiopathic pulmonary fibrosis
Respir Med. 2024 Apr 25:107612. doi: 10.1016/j.rmed.2024.107612. Online ahead of print.
ABSTRACT
BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive condition associated with a variable prognosis. The relationship between socioeconomic status or distance travelled to respiratory clinics and prognosis is unclear.
RESEARCH QUESTION: To determine whether socioeconomic status, distance to hospital and time to referral affects survival in patients with IPF.
STUDY DESIGN AND METHODS: In this retrospective cohort study, we used data collected from the British Thoracic Society Interstitial Lung Diseases Registry, between 2013 and 2021 (n = 2359) and calculated the quintile of Index of Multiple Deprivation 2019 score, time from initial symptoms to hospital attendance and distance as the linear distance between hospital and home post codes. Survival was assessed using Cox proportional hazards models.
RESULTS: There was a significant association between increasing quintile of deprivation and duration of symptoms prior to hospital presentation, Gender Age Physiology (GAP) index and receipt of supplemental oxygen and antifibrotic therapies at presentation. The most deprived patients had worse overall survival compared to least deprived after adjusting for smoking status, GAP index, distance to hospital and time to referral (HR = 1.39 [1.11, 1.73]; p = 0.003). Patients living furthest from a respiratory clinic also had worse survival compared to those living closest (HR = 1.29 [1.01, 1.64]; p = 0.041).
INTERPRETATION: The most deprived patients with IPF have more severe disease at presentation and worse outcomes. Living far from hospital was also associated with poor outcomes. This suggests inequalities in access to healthcare and requires consideration in delivering effective and equitable care to patients with IPF.
PMID:38677526 | DOI:10.1016/j.rmed.2024.107612
Curculigoside Attenuates Endoplasmic Reticulum Stress-Induced Epithelial Cell and Fibroblast Senescence by Regulating the SIRT1-P300 Signaling Pathway
Antioxidants (Basel). 2024 Mar 29;13(4):420. doi: 10.3390/antiox13040420.
ABSTRACT
The senescence of alveolar epithelial cells (AECs) and fibroblasts plays a pivotal role in the pathogenesis of idiopathic pulmonary fibrosis (IPF), a condition lacking specific therapeutic interventions. Curculigoside (CCG), a prominent bioactive constituent of Curculigo, exhibits anti-osteoporotic and antioxidant activities. Our investigation aimed to elucidate the anti-senescence and anti-fibrotic effects of CCG in experimental pulmonary fibrosis and delineate its underlying molecular mechanisms. Our findings demonstrate that CCG attenuates bleomycin-induced pulmonary fibrosis and lung senescence in murine models, concomitantly ameliorating lung function impairment. Immunofluorescence staining for senescence marker p21, alongside SPC or α-SMA, suggested that CCG's mitigation of lung senescence correlates closely with the deceleration of senescence in AECs and fibroblasts. In vitro, CCG mitigated H2O2-induced senescence in AECs and the natural senescence of primary mouse fibroblasts. Mechanistically, CCG can upregulate SIRT1 expression, downregulating P300 expression, enhancing Trim72 expression to facilitate P300 ubiquitination and degradation, reducing the acetylation levels of antioxidant enzymes, and upregulating their expression levels. These actions collectively inhibited endoplasmic reticulum stress (ERS) and alleviated senescence. Furthermore, the anti-senescence effects and mechanisms of CCG were validated in a D-galactose (D-gal)-induced progeroid model. This study provides novel insights into the mechanisms underlying the action of CCG in cellular senescence and chronic diseases, offering potential avenues for the development of innovative drugs or therapeutic strategies.
PMID:38671868 | DOI:10.3390/antiox13040420
Mimosa pudica L. extract ameliorates pulmonary fibrosis via modulation of MAPK signaling pathways and FOXO3 stabilization
J Ethnopharmacol. 2024 Apr 24:118226. doi: 10.1016/j.jep.2024.118226. Online ahead of print.
ABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing pulmonary disorder that has a poor prognosis and high mortality. Although there has been extensive effort to introduce several new anti-fibrotic agents in the past decade, IPF remains an incurable disease. Mimosa pudica L., an indigenous Vietnamese plant, has been empirically used to treat respiratory disorders. Nevertheless, the therapeutic effects of M. pudica (MP) on lung fibrosis and the mechanisms underlying those effects remain unclear.
AIM OF THE STUDY: This study investigated the protective effect of a crude ethanol extract of the above-ground parts of MP against pulmonary fibrogenesis.
MATERIALS AND METHODS: Inflammatory responses triggered by TNFα in structural lung cells were examined in normal human lung fibroblasts and A549 alveolar epithelial cells using Western blot analysis, reverse transcription-quantitative polymerase chain reaction assays, and immunocytochemistry. The epithelial-to-mesenchymal transition (EMT) was examined via cell morphology observations, F-actin fluorescent staining, gene and protein expression measurements, and a wound-healing assay. Anti-fibrotic assays including collagen release, differentiation, and measurements of fibrosis-related gene and protein expression levels were performed on TGFβ-stimulated human lung fibroblasts and lung fibroblasts derived from mice with fibrotic lungs. Finally, in vitro anti-fibrotic activities were validated using a mouse model of bleomycin-induced pulmonary fibrosis.
RESULTS: MP alleviated the inflammatory responses of A549 alveolar epithelial cells and lung fibroblasts, as revealed by inhibition of TNFα-induced chemotactic cytokine and chemokine expression, along with inactivation of the MAPK and NFκB signalling pathways. MP also partially reversed the TGFβ-promoted EMT via downregulation of mesenchymal markers in A549 cells. Importantly, MP decreased the expression levels of fibrosis-related genes/proteins including collagen I, fibronectin, and αSMA; moreover, it suppressed collagen secretion and prevented myofibroblast differentiation in lung fibroblasts. These effects were mediated by FOXO3 stabilization through suppression of TGFβ-induced ERK1/2 phosphorylation. MP consistently protected mice from the onset and progression of bleomycin-induced pulmonary fibrosis.
CONCLUSION: This study explored the multifaceted roles of MP in counteracting the pathobiological processes of lung fibrosis. The results suggest that further evaluation of MP could yield candidate therapies for IPF.
PMID:38670401 | DOI:10.1016/j.jep.2024.118226
lncRNA-mRNA Co-Expression and Regulation Analysis in Lung Fibroblasts from Idiopathic Pulmonary Fibrosis
Noncoding RNA. 2024 Apr 17;10(2):26. doi: 10.3390/ncrna10020026.
ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease marked by abnormal accumulation of extracellular matrix (ECM) due to dysregulated expression of various RNAs in pulmonary fibroblasts. This study utilized RNA-seq data meta-analysis to explore the regulatory network of hub long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) in IPF fibroblasts. The meta-analysis unveiled 584 differentially expressed mRNAs (DEmRNA) and 75 differentially expressed lncRNAs (DElncRNA) in lung fibroblasts from IPF. Among these, BCL6, EFNB1, EPHB2, FOXO1, FOXO3, GNAI1, IRF4, PIK3R1, and RXRA were identified as hub mRNAs, while AC008708.1, AC091806.1, AL442071.1, FAM111A-DT, and LINC01989 were designated as hub lncRNAs. Functional characterization revealed involvement in TGF-β, PI3K, FOXO, and MAPK signaling pathways. Additionally, this study identified regulatory interactions between sequences of hub mRNAs and lncRNAs. In summary, the findings suggest that AC008708.1, AC091806.1, FAM111A-DT, LINC01989, and AL442071.1 lncRNAs can regulate BCL6, EFNB1, EPHB2, FOXO1, FOXO3, GNAI1, IRF4, PIK3R1, and RXRA mRNAs in fibroblasts bearing IPF and contribute to fibrosis by modulating crucial signaling pathways such as FoxO signaling, chemical carcinogenesis, longevity regulatory pathways, non-small cell lung cancer, and AMPK signaling pathways.
PMID:38668384 | DOI:10.3390/ncrna10020026
A Machine Learning System to Indicate Diagnosis of Idiopathic Pulmonary Fibrosis Non-Invasively in Challenging Cases
Diagnostics (Basel). 2024 Apr 17;14(8):830. doi: 10.3390/diagnostics14080830.
ABSTRACT
Radiologic usual interstitial pneumonia (UIP) patterns and concordant clinical characteristics define a diagnosis of idiopathic pulmonary fibrosis (IPF). However, limited expert access and high inter-clinician variability challenge early and pre-invasive diagnostic sensitivity and differentiation of IPF from other interstitial lung diseases (ILDs). We investigated a machine learning-driven software system, Fibresolve, to indicate IPF diagnosis in a heterogeneous group of 300 patients with interstitial lung disease work-up in a retrospective analysis of previously and prospectively collected registry data from two US clinical sites. Fibresolve analyzed cases at the initial pre-invasive assessment. An Expert Clinical Panel (ECP) and three panels of clinicians with varying experience analyzed the cases for comparison. Ground Truth was defined by separate multi-disciplinary discussion (MDD) with the benefit of surgical pathology results and follow-up. Fibresolve met both pre-specified co-primary endpoints of sensitivity superior to ECP and significantly greater specificity (p = 0.0007) than the non-inferior boundary of 80.0%. In the key subgroup of cases with thin-slice CT and atypical UIP patterns (n = 124), Fibresolve's diagnostic yield was 53.1% [CI: 41.3-64.9] (versus 0% pre-invasive clinician diagnostic yield in this group), and its specificity was 85.9% [CI: 76.7-92.6%]. Overall, Fibresolve was found to increase the sensitivity and diagnostic yield for IPF among cases of patients undergoing ILD work-up. These results demonstrate that in combination with standard clinical assessment, Fibresolve may serve as an adjunct in the diagnosis of IPF in a pre-invasive setting.
PMID:38667475 | DOI:10.3390/diagnostics14080830
Smoking and idiopathic pulmonary fibrosis: A meta-analysis
Nicotine Tob Res. 2024 Apr 26:ntae100. doi: 10.1093/ntr/ntae100. Online ahead of print.
ABSTRACT
INTRODUCTION: In this study, we aimed to systematically explore the relationship between smoking and idiopathic pulmonary fibrosis (IPF).
METHODS: The PubMed, Web of Science and Embase databases were searched to systematically identify eligible studies. The Newcastle‒Ottawa Quality Assessment Scale (NOS) was used to evaluate the quality of the selected studies. The pooled odds ratio (OR) and survival hazard ratio (HR) were calculated with a random effects model using Stata 16.0 software.
RESULTS: Thirty studies were enrolled. All of the included studies were considered to have intermediate or high quality. Nine studies were suitable for meta-analysis of ORs, and twenty-one studies were suitable for meta-analysis of survival HR. The pooled analysis revealed a significant difference in the risk of IPF between the smoking group and the never smoking group (OR 1.71, 95% CI 1.27-2.30, P < 0.001), indicating that smoking is a risk factor for IPF. When analyzing pooled survival HRs, never smoking was compared to former smoking or current smoking. Former smoking was shown to be a poor prognostic factor for IPF (HR 1.43, 95% CI 1.18-1.74, P < 0.001), but current smoking was not a significant factor.
CONCLUSIONS: Our results indicated that smoking is a risk factor for IPF patients.
IMPLICATIONS: In this study, we mainly concluded that smoking is a risk factor for IPF and that former smoking is a poor prognostic factor for IPF. To our knowledge, this is the first meta-analysis report focusing on the association between smoking per se and IPF. Through our current study, we hope to further raise awareness of the relationship between smoking and IPF.
PMID:38666790 | DOI:10.1093/ntr/ntae100
A preoperative use of manual therapy in a patient with idiopathic pulmonary fibrosis awaiting lung transplant: a case report
Physiother Theory Pract. 2024 Apr 26:1-12. doi: 10.1080/09593985.2024.2343046. Online ahead of print.
ABSTRACT
INTRODUCTION: This case report describes the outcomes of a patient with idiopathic pulmonary fibrosis (IPF) treated with manual therapy (MT) in an outpatient physical therapy setting. IPF is a life-threatening interstitial lung disease, often requiring lung transplant for prolonged health related quality of life and survival. There is little literature to support use of MT for IPF.
CLINICAL FINDINGS: The patient was a 66-year-old male with IPF and on the Organ Procurement and Transplant Network (OPTN). The patient was dependent on oxygen and referred to physical therapy with neck pain, shoulder pain, and headaches. Evaluation revealed impairments classified as thoracic hypomobility paired with upper extremity referred pain, shoulder impairments and neck pain. Headaches were classified as cervicogenic in nature.
OUTCOMES: Improved objective measures of cardiovascular function and quality of life pre- and post- transplant were observed in this patient after 14 treatment visits.
DISCUSSION: The utilization of MT appeared to address the patient's impairments, improved quality of life, improved pulmonary function and improved transplant outcomes.
PMID:38666526 | DOI:10.1080/09593985.2024.2343046
Protection of Qingfei Xieding prescription from idiopathic pulmonary fibrosis by regulating renin-angiotensin and ferroptosis in MLE-12 cells
Histol Histopathol. 2024 Apr 11:18746. doi: 10.14670/HH-18-746. Online ahead of print.
ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is a lifelong lung disease, but there is no specific drug for treatment. Qingfei Xieding prescription (QF) is active in the treatment of lung diseases. More comprehensive mechanisms over how QF exhibits anti-pulmonary fibrosis need to be elucidated. TGF-β was used to construct a pulmonary fibrosis cell model in vitro. Bleomycin was applied to induce a lung tissue fibrosis model in mice in vivo. Flow cytometry was used to detect cellular ROS and lipid oxidation levels. Cell substructure was observed by Transmission Electron Microscopy. ELISA was used to determine the levels of inflammatory factors. HE staining, Masson staining and immunohistochemistry were performed to evaluate the degree of fibrosis. Western Blot assay was used to determine the protein expressions of different molecules. In TGF-β-exposed lung epithelial MLE-12 cell model, α-SMA and Collagen I were significantly elevated and cell viability was reduced. QF treatment restored the cell viability decreased by exogenous TGF-β. Ferroptosis inducer Erastin administration could reverse the beneficial effects such as lipid oxidation and ROS reduction caused by QF treatment. QF was proven to inhibit ferroptosis and alleviated the process of IPF by activating ACE2 signal axis. In bleomycin induced IPF mice model, QF altered lung coefficient, body weight and the expression of inflammatory factors, which were prevented by ferroptosis activator Erastin. QF was demonstrated to affect the ACE2-ERK signaling axis in vivo. QF alleviated idiopathic pulmonary fibrosis by regulating renin-angiotensin through blocking ferroptosis. This research offers evidence for the potentiality of QF in clinical application for IPF therapy.
PMID:38666295 | DOI:10.14670/HH-18-746
O-GlcNAc transferase regulates collagen deposition and fibrosis resolution in idiopathic pulmonary fibrosis
Front Immunol. 2024 Apr 11;15:1387197. doi: 10.3389/fimmu.2024.1387197. eCollection 2024.
ABSTRACT
BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic pulmonary disease that is characterized by an excessive accumulation of extracellular matrix (ECM) proteins (e.g. collagens) in the parenchyma, which ultimately leads to respiratory failure and death. While current therapies exist to slow the progression, no therapies are available to resolve fibrosis.
METHODS: We characterized the O-linked N-Acetylglucosamine (O-GlcNAc) transferase (OGT)/O-GlcNAc axis in IPF using single-cell RNA-sequencing (scRNA-seq) data and human lung sections and isolated fibroblasts from IPF and non-IPF donors. The underlying mechanism(s) of IPF were further investigated using multiple experimental models to modulate collagen expression and accumulation by genetically and pharmacologically targeting OGT. Furthermore, we hone in on the transforming growth factor-beta (TGF-β) effector molecule, Smad3, by co-expressing it with OGT to determine if it is modified and its subsequent effect on Smad3 activation.
RESULTS: We found that OGT and O-GlcNAc levels are upregulated in patients with IPF compared to non-IPF. We report that the OGT regulates collagen deposition and fibrosis resolution, which is an evolutionarily conserved process demonstrated across multiple species. Co-expression of OGT and Smad3 showed that Smad3 is O-GlcNAc modified. Blocking OGT activity resulted in decreased phosphorylation at Ser-423/425 of Smad3 attenuating the effects of TGF-β1 induced collagen expression/deposition.
CONCLUSION: OGT inhibition or knockdown successfully blocked and reversed collagen expression and accumulation, respectively. Smad3 is discovered to be a substrate of OGT and its O-GlcNAc modification(s) directly affects its phosphorylation state. These data identify OGT as a potential target in pulmonary fibrosis resolution, as well as other diseases that might have aberrant ECM/collagen accumulation.
PMID:38665916 | PMC:PMC11043510 | DOI:10.3389/fimmu.2024.1387197
A Rare Case of Idiopathic Pleuro-Parenchymal Fibroelastosis Presenting With Bilateral Spontaneous Pneumothoraces
Cureus. 2024 Mar 26;16(3):e56975. doi: 10.7759/cureus.56975. eCollection 2024 Mar.
ABSTRACT
Pleuroparenchymal fibroelastosis (PPFE) is a rare interstitial lung disease (ILD), characterized by predominantly upper lobe pleural and subjacent sub-pleural parenchymal fibrosis. Its name refers to a combination of fibrosis involving the visceral pleura with fibroelastotic changes, predominantly in the subpleural lung parenchyma. We describe the case of a 67-year-old lady who presented to the accident and emergency department of Weston General Hospital with worsening shortness of breath (SOB) and cachexia of six to eight months' duration. The initial imaging studies showed bilateral spontaneous pneumothoraces on a background of pleural-based consolidation and fibrotic changes. A subsequent high-resolution CT (HRCT) chest showed evidence of pleuroparenchymal fibroelastosis in the background. She was not considered for anti-fibrotic medications due to the advanced stage of the disease and was managed with supportive measures, including oxygen support, oral steroids and antibiotics to cover for any infections. After initial management of symptoms and long discussions with the patient, family and the palliative team, she was discharged home with community follow-up.
PMID:38665718 | PMC:PMC11045163 | DOI:10.7759/cureus.56975
Antifibrotic treatment adherence, efficacy and outcomes for patients with idiopathic pulmonary fibrosis in Spain: a real-world evidence study
BMJ Open Respir Res. 2024 Apr 24;11(1):e001687. doi: 10.1136/bmjresp-2023-001687.
ABSTRACT
BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a rare disorder associated with increased mortality and morbidity. There are currently two drugs approved for IPF but their safety and efficacy profile in real-world settings in Spain is not well understood.
METHODS: An observational, multicentre, prospective study was carried out among patients with IPF who started treatment with pirfenidone or nintedanib from 2015 to 2021. Data regarding clinical characteristics, drug adherence, safety profiles and clinical outcomes between these two drugs were collected.
RESULTS: 232 patients were included in the analysis. There were no meaningful differences between both groups at baseline. Patients who started pirfenidone showed a decreased risk for treatment withdrawal compared with those starting nintedanib (HR 0.65 (95% CI 0.46 to 0.94; p=0.002)). Time to first adverse event and all-cause mortality was similar between study groups. Risk factors for withdrawal were female sex, diarrhoea and photosensitivity.
CONCLUSIONS: in this real-world study, both pirfenidone and nintedanib showed similar efficacy profiles. Pirfenidone was associated with less treatment discontinuations due to side effects.
PMID:38663886 | DOI:10.1136/bmjresp-2023-001687
Body weight loss is a simple and useful indicator of prognosis and predictive tolerability in the first year of nintedanib therapy in patients with interstitial lung disease
Respir Investig. 2024 Apr 24;62(4):551-557. doi: 10.1016/j.resinv.2024.04.011. Online ahead of print.
ABSTRACT
BACKGROUND: Nintedanib is generally safe and well tolerated and can improve prognosis in patients with various interstitial lung diseases (ILDs). Appropriate management of adverse events of nintedanib is important to ensure its long-term persistent use. Weight loss is a routinely assessed adverse event in clinical practice. This study aimed to elucidate whether body weight change in the first year of nintedanib therapy can indicate prognosis and predict tolerability in patients with ILD.
METHODS: We analysed 245 consecutive ILD patients treated with nintedanib. We calculated the slope of body weight change using baseline weight and that recorded closest after the first year and then categorized percent change in body weight at this time. Significant weight loss was defined as that ≥5%.
RESULTS: Subjects included 67 patients with idiopathic pulmonary fibrosis (IPF) and 76 with non-IPF progressive fibrosing-ILD including fibrotic hypersensitivity pneumonitis (n = 16), unclassifiable (n = 35), connective tissue disease-ILD (n = 21), and nonspecific interstitial pneumonia (n = 4). Older age, low body weight at initial examination, significant weight loss, and lower %FVC were significant predictors of discontinuation of nintedanib. Patients with weight loss ≥5% over the first year showed worse survival than those with weight loss <5% regardless of whether IPF existed or BMI indicated obesity.
CONCLUSIONS: Careful monitoring of body weight change might suggest useful information for predicting long-term use of nintedanib and mortality risk in ILD patients treated with nintedanib. Appropriate body weight management is needed to prevent adverse events of nintedanib itself.
PMID:38663299 | DOI:10.1016/j.resinv.2024.04.011
A protective role for B-1 cells and oxidation-specific epitope IgM in lung fibrosis
bioRxiv [Preprint]. 2024 Apr 15:2024.04.11.589137. doi: 10.1101/2024.04.11.589137.
ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is a morbid fibrotic lung disease with limited treatment options. The pathophysiology of IPF remains poorly understood, and elucidation of the cellular and molecular mechanisms of IPF pathogenesis is key to the development of new therapeutics. B-1 cells are an innate B cell population which play an important role linking innate and adaptive immunity. B-1 cells spontaneously secrete natural IgM and prevent inflammation in several disease states. One class of these IgM recognize oxidation-specific epitopes (OSE), which have been shown to be generated in lung injury and to promote fibrosis. A main B-1 cell reservoir is the pleural space, adjacent to the typical distribution of fibrosis in IPF. In this study, we demonstrate that B-1 cells are recruited to the lung during injury where they secrete IgM to OSE (IgM OSE ). We also show that the pleural B-1 cell reservoir responds to lung injury through regulation of the chemokine receptor CXCR4. Mechanistically we show that the transcription factor Id3 is a novel negative regulator of CXCR4 expression. Using mice with B-cell specific Id3 deficiency, a model of increased B-1b cells, we demonstrate decreased bleomycin-induced fibrosis compared to littermate controls. Furthermore, we show that mice deficient in secretory IgM ( sIgM -/- ) have higher mortality in response to bleomycin-induced lung injury, which is partially mitigated through airway delivery of the IgM OSE E06. Additionally, we provide insight into potential mechanisms of IgM in attenuation of fibrosis through RNA sequencing and pathway analysis, highlighting complement activation and extracellular matrix deposition as key differentially regulated pathways.
PMID:38659897 | PMC:PMC11042183 | DOI:10.1101/2024.04.11.589137
Mendelian randomisation highlights type 1 diabetes as a causal determinant of idiopathic pulmonary fibrosis
Diabetol Metab Syndr. 2024 Apr 24;16(1):90. doi: 10.1186/s13098-024-01331-x.
ABSTRACT
BACKGROUND: It is unclear whether type 1 diabetes (T1D) causes idiopathic pulmonary fibrosis (IPF), despite observational research linking the two conditions. Therefore, our study aimed to examine the causal link between T1D and the likelihood of IPF by employing the Mendelian randomization (MR) technique of two-sample Mendelian randomization.
METHODS: Using data from two genome-wide association studies (GWAS) with European ancestry, we performed a two-sample MR analysis. These studies involved 18,856 individuals (6,683 cases and 12,173 controls) for T1D and 198,014 individuals (10,028 cases and 196,986 controls) for IPF. We utilized inverse-variance weighted (IVW) analysis as our main approach to determine the association between the risk of IPF and T1D. To evaluate multidirectionality, the MR-Egger regression test was utilized, whereas heterogeneity was assessed using Cochran's Q test. Additionally, a leave-one-out analysis was performed to assess the reliability of the results.
RESULTS: 38 SNPs linked to T1D were employed as instrumental variables (IVs). Multiple MR methods yielded consistent results, and the MR analysis reveals a significant and positive causal impact of T1D on IPF (MR-IVW, odds ratio [OR] = 1.128, 95% confidence interval [CI] 1.034-1.230; P = 0.006). The limitations of the study include the lack of data from non-European groups and the inability to rule out the possibility of small links. Larger MR experiments are necessary to investigate minute impacts.
CONCLUSIONS: The results of this study provide evidence that T1D contributes to the onset and advancement of IPF. This finding may provide important insights into the cause of IPF and possible treatments in the future.
PMID:38659065 | DOI:10.1186/s13098-024-01331-x
Downregulation of HMGCS2 mediated AECIIs lipid metabolic alteration promotes pulmonary fibrosis by activating fibroblasts
Respir Res. 2024 Apr 24;25(1):176. doi: 10.1186/s12931-024-02816-z.
ABSTRACT
BACKGROUND: Abnormal lipid metabolism has recently been reported as a crucial signature of idiopathic pulmonary fibrosis (IPF). However, the origin and biological function of the lipid and possible mechanisms of increased lipid content in the pathogenesis of IPF remains undetermined.
METHODS: Oil-red staining and immunofluorescence analysis were used to detect lipid accumulation in mouse lung fibrosis frozen sections, Bleomycin-treated human type II alveolar epithelial cells (AECIIs) and lung fibroblast. Untargeted Lipid omics analysis was applied to investigate differential lipid species and identified LysoPC was utilized to treat human lung fibroblasts and mice. Microarray and single-cell RNA expression data sets identified lipid metabolism-related differentially expressed genes. Gain of function experiment was used to study the function of 3-hydroxy-3-methylglutaryl-Coa Synthase 2 (HMGCS2) in regulating AECIIs lipid metabolism. Mice with AECII-HMGCS2 high were established by intratracheally delivering HBAAV2/6-SFTPC- HMGCS2 adeno-associated virus. Western blot, Co-immunoprecipitation, immunofluorescence, site-directed mutation and flow cytometry were utilized to investigate the mechanisms of HMGCS2-mediated lipid metabolism in AECIIs.
RESULTS: Injured AECIIs were the primary source of accumulated lipids in response to Bleomycin stimulation. LysoPCs released by injured AECIIs could activate lung fibroblasts, thus promoting the progression of pulmonary fibrosis. Mechanistically, HMGCS2 was decreased explicitly in AECIIs and ectopic expression of HMGCS2 in AECIIs using the AAV system significantly alleviated experimental mouse lung fibrosis progression via modulating lipid degradation in AECIIs through promoting CPT1A and CPT2 expression by interacting with PPARα.
CONCLUSIONS: These data unveiled a novel etiological mechanism of HMGCS2-mediated AECII lipid metabolism in the genesis and development of pulmonary fibrosis and provided a novel target for clinical intervention.
PMID:38658970 | DOI:10.1186/s12931-024-02816-z
Research progress of PD-L1 in inflammatory lung diseases
Sheng Li Xue Bao. 2024 Apr 25;76(2):346-352.
ABSTRACT
Programmed death-ligand 1 (PD-L1) is important in maintaining central and peripheral immune tolerance in normal tissues, mediating tumor immune escape and keeping the balance between anti- and pro-inflammatory responses. Inflammation plays an important role in inflammatory lung diseases. This article reviews the research progress and potential clinical value of PD-L1 in inflammatory lung diseases, including acute lung injury, chronic obstructive pulmonary disease, asthma and idiopathic pulmonary fibrosis.
PMID:38658383
Idiopathic pulmonary fibrosis (IPF): Diagnostic routes using novel biomarkers
Biomed J. 2024 Apr 22:100729. doi: 10.1016/j.bj.2024.100729. Online ahead of print.
ABSTRACT
Idiopathic pulmonary fibrosis (IPF) diagnosis is still the diagnosis of exclusion. Differentiating from other forms of interstitial lung diseases (ILDs) is essential, given the various therapeutic approaches. The IPF course is now unpredictable for individual patients, although some genetic factors and several biomarkers have already been associated with various IPF prognoses. Since its early stages, IPF may be asymptomatic, leading to a delayed diagnosis. The present review critically examines the recent literature on molecular biomarkers potentially useful in IPF diagnostics. The examined biomarkers are grouped into breath and sputum biomarkers, serologically assessed extracellular matrix neoepitope markers, and oxidative stress biomarkers in lung tissue. Fibroblasts and complete blood count have also gained recent interest in that respect. Although several biomarker candidates have been profiled, there has yet to be a single biomarker that proved specific to the IPF disease. Nevertheless, various IPF biomarkers have been used in preclinical and clinical trials to verify their predictive and monitoring potential.
PMID:38657859 | DOI:10.1016/j.bj.2024.100729
Lipid Deficiency Contributes to Impaired Alveolar Progenitor Cell Function in Aging and Idiopathic Pulmonary Fibrosis
Am J Respir Cell Mol Biol. 2024 Apr 24. doi: 10.1165/rcmb.2023-0290OC. Online ahead of print.
ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is an aging-associated interstitial lung disease resulting from repeated epithelial injury and inadequate epithelial repair. Alveolar type II cells (AEC2) are progenitor cells that maintain epithelial homeostasis and repair the lung after injury. In the current study, we assessed lipid metabolism in AEC2s from human lungs of IPF patients and healthy donors, as well as AEC2s from bleomycin-injured young and old mice. Through single cell RNA sequencing (scRNA-seq), we observed that lipid metabolism-related genes were downregulated in IPF AEC2s and bleomycin-injured mouse AEC2s. Aging aggravated this decrease and hindered recovery of lipid metabolism gene expression in AEC2s after bleomycin injury. Pathway analyses revealed down-regulation of genes related to lipid biosynthesis and fatty acid -oxidation in AEC2s from IPF lungs and bleomycin-injured, aged mouse lungs compared to the respective controls. We confirmed decreased cellular lipid content in AEC2s from IPF lungs and bleomycin-injured, aged mouse lungs using immunofluorescence staining and flow cytometry. We further show that lipid metabolism was associated with AEC2 progenitor function. Lipid supplementation and peroxisome proliferator activated receptor gamma (PPARγ) activation promoted progenitor renewal capacity of both human and mouse AEC2s in 3D organoid cultures. Lipid supplementation also increased AEC2 proliferation and expression of SFTPC in AEC2s. In summary, we identified a lipid metabolism deficiency in AEC2s from lungs of patients with IPF and bleomycin-injured aged mice. Restoration of lipid metabolism homeostasis in AEC2s might promote AEC2 progenitor function and offer new opportunities for therapeutic approaches to IPF.
PMID:38657143 | DOI:10.1165/rcmb.2023-0290OC
Progressive pulmonary Fibrosis
Ther Umsch. 2024 Feb;81(1):12-15.
ABSTRACT
Progressive pulmonary Fibrosis Abstract: Cough and dyspnea on excertion are common and early symptoms of interstitial lung diseases (ILD). Thoracic imaging (particularly computed tomography) detects such lung structural alterations early in the disease course. Knowledge of these diseases and their management is necessary in the daily business. The term "progressive pulmonary fibrosis" subsumes a heterogene group of interstitial lung diseases with a similar course of progressive fibrosis. The management of these diseases should be discussed interdisciplinary, similar to the management of the Idiopathic pulmonary fibrosis (IPF). Antifibrotic drugs are new therapeutic options.
PMID:38655828