Idiopathic Pulmonary Fibrosis: An Update on Pathogenesis

METTL14-mediated m6A modification of DDIT4 promotes its mRNA stability in aging-related idiopathic pulmonary fibrosis

Although N6-methyladenosine (m6A) may be related to the pathogenesis of fibrotic process, the mechanism of m6A modification in aging-related idiopathic pulmonary fibrosis (IPF) remains unclear. Three-milliliter venous blood was collected from IPF patients and healthy controls. MeRIP-seq and RNA-seq were utilized to investigate differential m6A modification. The expressions of identified m6A regulator and target gene were validated using MeRIP-qPCR and real-time PCR. Moreover, we established an animal model and a senescent model of A549 cells to explore the associated molecular mechanism. Our study provided a panorama of m6A methylation in IPF. Increased peaks (3756) and decreased peaks (4712) were observed in the IPF group. The association analysis showed that 749 DEGs were affected by m6A methylation in IPF. Among the m6A regulators, the expression of METTL14 decreased in IPF. The m6A level of our interested gene DDIT4 decreased significantly, but the mRNA level of DDIT4 was higher in IPF. This was further verified in bleomycin-induced pulmonary fibrosis. At the cellular level, it was further confirmed that METTL14 and DDIT4 might participate in the senescence of alveolar epithelial cells. The downregulation of METTL14 might inhibit the decay of DDIT4 mRNA by reducing the m6A modification level of DDIT4 mRNA, leading to high expression of DDIT4 mRNA and protein. Our study provided a panorama of m6A alterations in IPF and discovered METTL14 as a potential intervention target for epigenetic modification in IPF. These results pave the way for future investigations regarding m6A modifications in aging-related IPF.

Epigenetic targets and their inhibitors in the treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a deadly lung disease characterized by fibroblast proliferation, excessive extracellular matrix buildup, inflammation, and tissue damage, resulting in respiratory failure and death. Recent studies suggest that impaired interactions among epithelial, mesenchymal, immune, and endothelial cells play a key role in IPF development. Advances in bioinformatics have also linked epigenetics, which bridges gene expression and environmental factors, to IPF. Despite the incomplete understanding of the pathogenic mechanisms underlying IPF, recent preclinical studies have identified several novel epigenetic therapeutic targets, including DNMT, EZH2, G9a/GLP, PRMT1/7, KDM6B, HDAC, CBP/p300, BRD4, METTL3, FTO, and ALKBH5, along with potential small-molecule inhibitors relevant for its treatment. This review explores the pathogenesis of IPF, emphasizing epigenetic therapeutic targets and potential small molecule drugs. It also analyzes the structure-activity relationships of these epigenetic drugs and summarizes their biological activities. The objective is to advance the development of innovative epigenetic therapies for IPF.

Spatially Resolved Metabolomics Reveals Metabolic Heterogeneity Among Pulmonary Fibrosis

Pulmonary fibrosis (PF) is a chronic and progressive lung disease with fatal consequences. The study of PF is challenging due to the complex mechanism involved, the need to understand the heterogeneity and spatial organization within lung tissues. In this study, we investigate the metabolic heterogeneity between two forms of lung fibrosis: idiopathic pulmonary fibrosis (IPF) and silicosis, using advanced spatially-resolved metabolomics techniques. Employing high-resolution mass spectrometry imaging, we spatially mapped and identified over 260 metabolites in lung tissue sections from mouse models of IPF and silicosis. Histological analysis confirmed fibrosis in both models, with distinct pathological features: alveolar destruction and collagen deposition in IPF, and nodule formation in silicosis. Metabolomic analysis revealed significant differences between IPF and silicosis in key metabolic pathways, including phospholipid metabolism, purine/pyrimidine metabolism, and the TCA cycle. Notably, phosphocholine was elevated in silicosis but reduced in IPF, while carnitine levels decreased in both conditions. Additionally, glycolytic activity was increased in both models, but TCA cycle intermediates showed opposing trends. These findings highlight the spatial metabolic heterogeneity of PF and suggest potential metabolic targets for therapeutic intervention. Further investigation into the regulatory mechanisms behind these metabolic shifts may open new avenues for fibrosis treatment.

A novel lncRNA ABCE1-5 regulates pulmonary fibrosis by targeting KRT14

Idiopathic pulmonary fibrosis (IPF) is a progressive and degenerative interstitial lung disease characterized by complex etiology, unclear pathogenesis, and high mortality. Long noncoding RNAs (lncRNAs) have been identified as key regulators in modulating the initiation, maintenance, and progression of pulmonary fibrosis. However, the precise pathological mechanisms through which lncRNAs are involved in IPF remain limited and require further elucidation. A novel lncABCE1-5 was identified as significantly decreased by an ncRNA microarray analysis in our eight IPF lung samples compared with three donor tissues and validated by quantitative real-time polymerase chain reaction (qRT-PCR) analysis in clinical lung samples. To investigate the biological function of ABCE1-5, we performed loss- and gain-of-function experiments in vitro and in vivo. LncABCE1-5 silencing promoted A549 cell migration and A549 and bronchial epithelial cell line (BEAS-2B) cell apoptosis while enhancing the expression of proteins associated with extracellular matrix deposition, whereas overexpression of ABCE1-5 partially attenuated transforming growth factor-beta (TGF-β)-induced fibrogenesis. Forced ABCE1-5 expression by intratracheal injection of adeno-associated virus 6 revealing the antifibrotic effect of ABCE1-5 in bleomycin (BLM)-treated mice. Mechanistically, RNA pull-down (RPD)-mass spectrometry and RNA immunoprecipitation assay demonstrated that ABCE1-5 directly binds to keratin14 (krt14) sequences, potentially impeding its expression by perturbing mRNA stability. Furthermore, decreased ABCE1-5 levels can promote krt14 expression and enhance the phosphorylation of both mTOR and Akt; overexpression of ABCE1-5 in BLM mouse lung tissue significantly attenuated the elevated levels of p-mTOR and p-AKT. Knockdown of krt14 reversed the activation of mTOR signaling mediated by ABCE1-5 silencing. Collectively, the downregulation of ABCE1-5 mediated krt14 activation, thereby activating mTOR/AKT signaling, to facilitate pulmonary fibrosis progression in IPF.NEW & NOTEWORTHY In the present study, our data first reveal that a novel lncRNA ABCE1-5 could inhibit pulmonary fibrosis through interacting with krt14 and negative regulation of its expression, and indicated ABCE1-5 also regulates the phosphorylation of mTOR and Akt, thus acting on extracellular matrix remodeling in lung fibrosis procession. These results suggest that novel molecules within the ABCE1-5-krt14-mTOR axis may serve as potential candidates for clinical application in IPF.

Autophagy inhibition enhances antifibrotic potential of placental mesenchymal stem cells of fetal origin via regulating TGF-β1 mediated protein degradation of HGF

Mesenchymal stem cell (MSC) therapy represents a promising strategy for pulmonary fibrosis (PF) treatment, with hepatocyte growth factor (HGF) serving as a key mediator of MSC-mediated protection. However, the therapeutic efficacy of MSCs is limited by the complex PF microenvironment, and the mechanisms underlying this limitation remain unclear. This study investigates how the PF pathological microenvironment modulates the antifibrotic potential of placental mesenchymal stem cells of fetal origin (fPMSCs) through HGF regulation and elucidates the molecular mechanisms involved. Morphological analysis, flow cytometry, and multilineage differentiation assays were employed to characterize fPMSCs. Transforming growth factor-β1 (TGF-β1) was employed to simulate the PF microenvironment and activate fPMSCs in vitro. ELISA and Western blotting were used to analyze HGF expression, autophagy markers, and Smad signaling. Autophagosome formation was visualized via confocal microscopy and transmission electron microscopy. Co-immunoprecipitation (Co-IP) assays were performed to assess the interaction between p62 and HGF. The antifibrotic function of fPMSCs was further evaluated using a transwell co-culture system with MRC-5 fibroblasts in vitro and a bleomycin-induced PF mouse model in vivo. Phenotypic characterization confirmed that fPMSCs exhibited canonical MSC morphology, expressed CD73/CD90/CD105, lacked CD14/CD34/CD45/HLA-DR, and differentiated into adipogenic, osteogenic, and chondrogenic lineages. TGF-β1 treatment robustly downregulated the antifibrotic capacity, HGF protein expression, and paracrine secretion in fPMSCs. Recombinant HGF enhanced antifibrotic effects, while an HGF-neutralizing antibody abolished them. TGF-β1 induced autophagy in fPMSCs, promoting HGF degradation via p62 interaction and impairing antifibrotic function in vitro and in vivo. Mechanistically, Smad3 phosphorylation mediated the regulation of autophagy and HGF expression in TGF-β1-treated fPMSCs. Our findings demonstrate that TGF-β1 impairs the antifibrotic function of fPMSCs via autophagy-dependent HGF degradation and Smad3 signaling. Conversely, autophagy inhibition restores HGF levels and enhances fPMSCs' therapeutic efficacy in a preclinical PF model. Targeting autophagy inhibition emerges as a promising therapeutic strategy to counteract pulmonary fibrosis.

Proteomics and Metabolomics Analyses Reveal a Dynamic Landscape of Coal Workers' Pneumoconiosis: An Insight into Disease Progression

Coal worker's pneumoconiosis (CWP) is characterized by chronic inflammation and pulmonary fibrosis. The key factor contributing to the incurability of CWP is the unclear pathogenesis. This study explored the characteristic changes in proteomics and metabolomics of early and advanced CWP patients through proteomics and metabolomics techniques. Proteomics identified proteins that change with the progression of CWP, with significant enrichment in the TGF-β signaling pathway and autoimmune disease pathways. Metabolomics revealed the metabolic characteristics of CWP at different stages. These metabolites mainly include changes in amino acid metabolism, unsaturated fatty acid synthesis, and related metabolites. Integrated analysis found that ABC transporters are a shared pathway among the three groups, and ABCD2 is involved in the ABC transporter pathway. In the subsequent independent sample verification analysis, consistent with proteomics experiments, compared to the CM group, FMOD expression level was upregulated in the NIC group. TFR expression level was consistently downregulated in both the IC and NIC groups. Additionally, ABCD2 increased in the IC group but decreased in the NIC group. In summary, this study revealed the metabolic characteristics of CWP at different stages. These findings may provide valuable insights for the early prediction, diagnosis, and treatment of CWP.

SIRT3/6/7: promising therapeutic targets for pulmonary fibrosis

Pulmonary fibrosis is a chronic progressive fibrosing interstitial lung disease of unknown cause, characterized by excessive deposition of extracellular matrix, leading to irreversible decline in lung function and ultimately death due to respiratory failure and multiple complications. The Sirtuin family is a group of nicotinamide adenine dinucleotide (NAD+) -dependent histone deacetylases, including SIRT1 to SIRT7. They are involved in various biological processes such as protein synthesis, metabolism, cell stress, inflammation, aging and fibrosis through deacetylation. This article reviews the complex molecular mechanisms of the poorly studied SIRT3, SIRT6, and SIRT7 subtypes in lung fibrosis and the latest research progress in targeting them to treat lung fibrosis.

A Novel Polysaccharide from the Flowers of Lilium lancifolium Alleviates Pulmonary Fibrosis In Vivo and In Vitro

Lily flowers are widely used in China for lung nourishment; however, their active ingredients remain unknown. To address this question, we isolated a novel polysaccharide (L005-B) from the flowers of Lilium lancifolium. Its backbone is comprised of Glcp, Galp, and 1,2-linked α-Rhap. The branch is composed of Xyl and T-α-Glcp residues substituted at the C-4 position of Rhap, along with portions of Glcp, Galp, Araf, and GlcpA residues substituted at the C-4 position of glucose or the C-3 position of galactose. Bioactivity study showed that L005-B alleviated fibrosis-associated protein (fibronectin, collagen, α-SMA) expression in TGF-β1-induced human fibroblast cells (MRC-5). Moreover, L005-B significantly inhibited the epithelial-mesenchymal transition of the human alveolar type II epithelial cell. More importantly, L005-B dramatically improved bleomycin-induced histopathological changes and attenuated the pulmonary index and hydroxyproline contents. Taken together, our findings revealed that L005-B may serve as a promising leading compound for the development of novel antipulmonary fibrosis therapeutics.

Deciphering the interplay: circulating cell-free DNA, signaling pathways, and disease progression in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a lung disease with an unknown etiology and a short survival rate. There is no accurate method of early diagnosis, and it involves computed tomography (CT) or lung biopsy. Since diagnostic methods are not accurate due to their similarity to other lung pathologies, discovering new biomarkers is a key issue for diagnosticians. Currently, the use of ccf-DNA (circulating cell-free deoxyribonucleic acid) is an important focus due to its association with IPF-induced alterations in metabolic pathways, such as amino acid metabolism, energy metabolism, and lipid metabolism pathways. Other biomarkers associated with metabolic changes have been found, and they are related to changes in type II/type I alveolar epithelial cells (AECs I/II), changes in extracellular matrix (ECM), and inflammatory processes. Currently, IPF pathogenetic treatment remains unknown, and the mortality rates are increasing, and the patients are diagnosed at a late stage. Signaling pathways and metabolic dysfunction have a significant role in the disease occurrence, particularly the transforming growth factor-β (TGF-β) signaling pathway, which plays an essential role. TGF-β, Wnt, Hedgehog (Hh), and integrin signaling are the main drivers of fibrosis. These pathways activate the transformation of fibroblasts into myofibroblasts, extracellular matrix (ECM) deposition, and tissue remodeling fibrosis. Therapy targeting diverse signaling pathways to slow disease progression is crucial in the treatment of IPF. Two antifibrotic medications, including pirfenidone and nintedanib, are Food and Drug Administration (FDA)-approved for treatment. ccf-DNA could become a new biomarker for IPF diagnosis to detect the disease at the early stage, while FDA-approved therapies could help to prevent late conditions from forming and decrease mortality rates.

Molecular Imaging of Pulmonary Fibrosis

Fibrosing lung diseases affect over 160,000 individuals in the United States alone and can carry a prognosis that is worse than many cancers. Antifibrotic treatments modify only the rate of fibrosis progression, and more effective therapies are urgently needed. Molecular imaging enables visualization of disease pathogenesis in progress. It provides a noninvasive means to monitor and quantify dysregulated molecular fibrotic pathways and shows great promise in aiding the diagnosis and disease activity monitoring of pulmonary fibrosis. Here, we review molecular imaging probes under development for use in pulmonary fibrosis. We provide our opinion on current challenges in translating preclinical molecular imaging probes into clinical successes, as well as future directions for expanding their use in drug development.

What rationale for treatment of occupational interstitial lung diseases with the drugs approved for idiopathic pulmonary fibrosis?

PURPOSE OF REVIEW

To critically discuss the rationale for the use of drugs approved for idiopathic pulmonary fibrosis (IPF) to treat occupational interstitial lung diseases (OILDs).

RECENT FINDINGS

Although IPF and OILDs share several clinical, radiological and probably pathogenetic features, currently, OILDs do not have a standard of care. In recent years, our knowledge and understanding of ILDs has improved substantially. Recently, the progressive pulmonary fibrosis (PPF) phenotype, which refers to non-IPF fibrotic ILDs that progress despite appropriate treatment, has been defined. OILDs may also be progressive. Nintedanib, initially approved for treatment of IPF, is also approved in patients with PPF. On the other hand, pirfenidone is approved in IPF but not in PPF, due to the lack of robust evidence of efficacy in this patient subset.

SUMMARY

OILDs are a large and highly heterogeneous group of conditions without a proper standard of care. Nintedanib may slow functional decline and disease progression in progressive OILDs, and new clinical trials are ongoing.

Health position paper and redox perspectives - Bench to bedside transition for pharmacological regulation of NRF2 in noncommunicable diseases

Nuclear factor erythroid 2-related factor 2 (NRF2) is a redox-activated transcription factor regulating cellular defense against oxidative stress, thereby playing a pivotal role in maintaining cellular homeostasis. Its dysregulation is implicated in the progression of a wide array of human diseases, making NRF2 a compelling target for therapeutic interventions. However, challenges persist in drug discovery and safe targeting of NRF2, as unresolved questions remain especially regarding its context-specific role in diseases and off-target effects. This comprehensive review discusses the dualistic role of NRF2 in disease pathophysiology, covering its protective and/or destructive roles in autoimmune, respiratory, cardiovascular, and metabolic diseases, as well as diseases of the digestive system and cancer. Additionally, we also review the development of drugs that either activate or inhibit NRF2, discuss main barriers in translating NRF2-based therapies from bench to bedside, and consider the ways to monitor NRF2 activation in vivo.

Interactions of flavonoid and coumarin derivative compounds with transforming growth factor-beta receptor 1 (TGF-βR1): integrating virtual screening, molecular dynamics, maximum common substructure, and ADMET approaches in the treatment of idiopathic pulmonary fibrosis

CONTEXT

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease characterized by very limited treatment options and significant side effects from existing therapies, highlighting the urgent need for more effective drug-like molecules. Transforming growth factor-beta receptor 1 (TGF-βR1) is a key player in the pathogenesis of IPF and represents a critical target for therapeutic intervention. In this study, the potential of plant-derived flavonoid and coumarin compounds as novel TGF-βR1 inhibitors was explored. A total of 1206 flavonoid and coumarin derivatives were investigated through a series of computational approaches, including drug-like filtering, virtual screening, molecular docking, 200-ns molecular dynamics (MD) simulations in triplicate, maximum common substructure (MCS) analysis, and absorption-distribution-metabolism-excretion-toxicity (ADMET) profiling. 2',3',4'-trihydroxyflavone and dicoumarol emerged as promising plant-based hit candidates, exhibiting comparable docking scores, MD-based structural stability, and more negative MM/PBSA binding free energy relative to the co-crystallized inhibitor, while surpassing pirfenidone in these parameters and demonstrating superior pharmacological properties. In light of the findings from this study, 2',3',4'-trihydroxyflavone and dicoumarol could be considered novel TGF-βR1 inhibitors for IPF treatment, and it is recommended that their structural optimization be pursued through in vitro binding assays and in vivo animal studies.

METHODS

The initial dataset of 1206 flavonoid and coumarin derivatives was filtered for drug-likeness using Lipinski's Rule of Five in the ChemMaster-Pro 1.2 program, resulting in 161 potential candidates. These compounds were then subjected to virtual screening against the TGF-βR1 kinase domain (PDB ID: 6B8Y) using AutoDock Vina 1.2.5, identifying the top three hit compounds-dicoumarol, 2',3',4'-trihydroxyflavone, and 2',3'-dihydroxyflavone. These hits underwent further exhaustive molecular docking for refinement of docking poses, followed by 200-ns MD simulations in triplicate using the AMBER03 force field in GROMACS. Subsequently, the binding free energies were calculated using the Molecular Mechanics/Poisson-Boltzmann Surface Area (MM/PBSA) method. MCS analysis was conducted to determine shared structural features among the top three hits, while ADMET properties were predicted using Deep-PK, a deep learning-based platform. Finally, the ligand-protein interactions were further visualized, analyzed, and rendered using ChimeraX, Discovery Studio Visualizer, and Visual Molecular Dynamics (VMD) program.

Exploring The Role of TOP2A in the Intersection of Pathogenic Mechanisms Between Rheumatoid Arthritis and Idiopathic Pulmonary Fibrosis Based on Bioinformatics

Background

Rheumatoid arthritis (RA) and idiopathic pulmonary fibrosis (IPF) share a common pathogenic mechanism, but the underlying mechanisms remain ambiguous. Our study aims at exploring the genetic-level pathogenic mechanism of these two diseases.

Methods

We carried out bioinformatics analysis on the GSE55235 and GSE213001 datasets. Machine learning was employed to identify candidate genes, which were further verified using the GSE92592 and GSE89408 datasets, as well as quantitative real-time PCR (qRT-PCR). The expression levels of TOP2A in RA and IPF in vitro models were confirmed using Western blotting and qRT-PCR. Furthermore, we explored the influence of TOP2A on the occurrence and development of RA and IPF by using the selective inhibitor PluriSIn #2 in an in vitro model. Finally, an in vivo model of RA and IPF was constructed to assess TOP2A expression levels via immunohistochemistry.

Results

Our bioinformatics analysis suggests a potential intersection in the pathogenic mechanisms of RA and IPF. We have identified 7 candidate genes: CXCL13, TOP2A, MMP13, MMP1, LY9, TENM4, and SEMA3E. Our findings reveal that the expression level of TOP2A is significantly elevated in both in vivo and in vitro models of RA and IPF. Additionally, our research indicates that PluriSIn #2 can effectively restrain inflammatory factors, extracellular matrix deposition, migration, invasion, the expression and nuclear uptake of p-smad2/3 protein in RA and IPF in vitro models.

Conclusion

There is a certain correlation between RA and IPF at the genetic level, and the molecular mechanisms of their pathogenesis overlap, which might be the reason for the progression of RA. Among the candidate genes we identified, TOP2A may influence the occurrence and development of RA and IPF through the TGF-β/Smad signal pathway. This could be beneficial to the study of the pathogenesis and treatment of RA and IPF.

Efficacy of ginkgo biloba extract in the treatment of idiopathic pulmonary fibrosis: a systematic review and meta-analysis of randomized controlled trials

Objective

This systematic review and meta-analysis aims to assess the efficacy of GBE in the treatment of IPF by evaluating its impact on total effective rate, blood gas analysis, pulmonary function tests, and markers of inflammation and fibrosis.

Methods

We conducted a comprehensive search across seven databases, including PubMed, EMBASE, Web of Science, CNKI, Wanfang DATA, VIP, and CBM, without restrictions on publication date. Randomized controlled trials (RCTs) that investigated the effects of GBE on IPF patients were eligible for inclusion. Relevant literature was screened, and the data in the included studies were extracted for quality assessment according to the Risk of bias tool.

Results

A total of 14 RCTs involving 1043 patients were included in the analysis. GBE significantly improved the total effective rate, arterial oxygen partial pressure, arterial oxygen saturation, forced vital capacity, forced expiratory volume in one second, maximum voluntary ventilation, and 6-min walk test compared to the control group. Additionally, there was a significant reduction in arterial carbon dioxide partial pressure, interleukin-4, hyaluronan, and laminin levels.

Conclusion

GBE may offer therapeutic benefits in IPF by improving respiratory function, modulating inflammation, and affecting fibrosis markers. These findings support the potential use of GBE as an adjunct therapy in IPF and suggest that further large-scale, multicenter trials are warranted to confirm its efficacy and safety.

Modification of the course of disease progression in idiopathic pulmonary fibrosis by pirfenidone: evidence of the potential for disease reversal

Idiopathic pulmonary fibrosis (IPF) is a fibrosing pneumonia of unknown causation with a chronic, progressive course that may be modified by treatment with the antifibrotic agents, pirfenidone and nintedanib. Both drugs have been shown to slow disease progression, but, in rare cases, pirfenidone has been shown to stabilise and even improve lung function. We present a case of a patient whose lung function and pathognomonic features on CT imaging improved significantly on commencement of treatment with pirfenidone. Withholding pirfenidone was associated with a functional and morphological deterioration on imaging that subsequently reversed and stabilised following recommencement of this treatment. We discuss potential mechanisms that might explain this treatment response, compare our case to others described previously and the potential consequences that restricted prescribing within a specified range of vital capacity may have on the opportunity to influence the natural history of IPF early before irreversible fibrosis develops.

The role of TRP channels in lung fibrosis: Mechanisms and therapeutic potential

Idiopathic pulmonary fibrosis (IPF) is a severe lung disease affecting around 5 million people globally, with a median survival of 3-4 years. Characterized by excessive scarring of lung tissue, IPF results from the accumulation of myofibroblasts that deposit extracellular matrix (ECM), causing fibrosis. Current treatments, pirfenidone and nintedanib, slow the disease but do not stop its progression. IPF pathogenesis involves repeated alveolar injury, leading to pro-fibrotic mediators like TGFβ1, which trigger fibroblast-to-myofibroblast transitions and ECM deposition. Recent research suggests that transient receptor potential (TRP) channels, such as TRPV4, TRPC6, and TRPA1, play a key role in regulating calcium signalling and mechanical stress, crucial in myofibroblast activation. Targeting TRP channels may disrupt fibrosis and offer new therapeutic strategies. Preclinical studies indicate that inhibiting TRP channels could reduce fibrosis, warranting further trials to explore their efficacy and safety in treating IPF and related fibrotic conditions.

Modulating NLRP3 Inflammasomes in Idiopathic Pulmonary Fibrosis: A Comprehensive Review on Flavonoid-Based Interventions

Idiopathic Pulmonary Fibrosis (IPF) is a severe, rapidly advancing disease that drastically diminishes life expectancy. Without treatment, it can progress to lung cancer. The precise etiology of IPF remains unknown, but inflammation and damage to the alveolar epithelium are widely thought to be pivotal in its development. Research has indicated that activating the NLRP3 inflammasome is a crucial mechanism in IPF pathogenesis, as it triggers the release of pro-inflammatory cytokines such as IL-1β, IL-18, and TGF-β. These cytokines contribute to the myofibroblast differentiation and extracellular matrix (ECM) accumulation. Currently, treatment options for IPF are limited. Only two FDA-approved medications, pirfenidone and nintedanib, are available. While these drugs can decelerate disease progression, they come with a range of side effects and do not cure the disease. Additional treatment strategies primarily involve supportive care and therapy. Emerging research has highlighted that numerous flavonoids derived from traditional medicines can inhibit the critical regulators responsible for activating the NLRP3 inflammasome. These flavonoids show promise as potential therapeutic agents for managing IPF, offering a new avenue for treatment that targets the core inflammatory processes of this debilitating condition.

Genome-wide CRISPR/Cas9 screening identifies key profibrotic regulators of TGF-β1-induced epithelial-mesenchymal transformation and pulmonary fibrosis

Background

The idiopathic pulmonary fibrosis (IPF) is a progressive and lethal interstitial lung disease with high morbidity and mortality. IPF is characterized by excessive extracellular matrix accumulation (ECM) and epithelial-mesenchymal transformation (EMT). To date, few anti-fibrotic therapeutics are available to reverse the progression of pulmonary fibrosis, and it is important to explore new profibrotic molecular regulators mediating EMT and pulmonary fibrosis.

Methods

Based on our model of TGF-β1-induced EMT in BEAS-2B cells, we performed the genome-wide CRISPR/Cas9 knockout (GeCKO) screening technique, pathway and functional enrichment analysis, loss-of-function experiment, as well as other experimental techniques to comprehensively investigate profibrotic regulators contributing to EMT and the pathogenesis of pulmonary fibrosis.

Results

Utilizing the GeCKO library screening, we identified 76 top molecular regulators. Ten candidate genes were subsequently confirmed by integrating the high-throughput data with findings from pathway and functional enrichment analysis. Among the candidate genes, knockout of COL20A1 and COL27A1 led to decreased mRNA expression of ECM components (Fibronectin and Collagen-I), as well as an increased rate of cell apoptosis. The mRNA expression of Collagen-I, together with the cell viability and migration, were inhibited when knocking out the WNT11. In addition, a decrease in the protein deposition of ECM components was observed by suppressing the expression of COL20A1, COL27A1, and WNT11.

Conclusion

Our study demonstrates that the COL20A1, COL27A1, and WNT11 serve as key profibrotic regulators of EMT. Gaining understanding and insights into these key profibrotic regulators of EMT paves the way for the discovery of new therapeutic targets against the onset and progression of IPF.

Extracellular Vesicles as a Potential Biomarker of Pulmonary Arterial Hypertension in Systemic Sclerosis

Introduction: Pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD) are severe complications of patients with systemic sclerosis (SSc). Currently, there are a few tests for early identification of these conditions, although they are invasive and time-consuming. Extracellular vesicles (EVs) offer a promising possibility for gathering information on tissue health. This study aims to characterize EVs in cases of systemic sclerosis complicated by pulmonary hypertension and pulmonary fibrosis. Methods: A cohort of 58 patients with SSc was evaluated, including 14 with pulmonary hypertension, 17 with pulmonary fibrosis, and 27 without complications. Additionally, 11 healthy subjects, matched for sex and age, served as a control group. EVs were characterized by using a MACSplex kit to analyze the expression of 37 membrane markers. Results: After the overall analysis, we show that EVs from SSc patients had higher expression of CD146, CD42a, and CD29 (p = 0.03, p = 0.02 and p = 0.05) but lower expression of HLA-ABC with respect to the control patients (p = 0.02). Multivariate analyses demonstrated that only CD42a has a significant association with the disease (p = 0.0478). In group comparative analyses (PAH, ILD, uncomplicated systemic sclerosis (named SSc no PAH no ILD), and controls), CD3 and CD56 were higher in PAH patients, with respect to the controls, ILD, and the group SSc no PAH no ILD (CD3: p = 0.01, p = 0.003, p = 0.0005; CD56: p = 0.002, p < 0.0001, p = 0.0002). HLA-DR showed higher expression in PAH patients with respect to ILD patients (p = 0.02), CD25 showed higher expression in PAH patients with respect uncomplicated SSc (p = 0.02), and CD42a showed higher expression in PAH patients with respect to the controls (p = 0.03); nevertheless, multivariate analyses demonstrated that only CD3 retained its association with PAH. Conclusions: The expression of CD42a, a platelet-derived marker indicating endothelial damage, suggests its potential to provide information on the state of the microcirculation in systemic sclerosis. The higher expression of CD3 on the surface of the EVs in PAH patients might indicate increased T-cell activity in tissues, with a possible association with the development of pulmonary hypertension.

Novel Cyclohexyl Amido Acid Antagonists of Lysophosphatidic Acid Type 1 Receptor for the Treatment of Pulmonary Fibrosis

Lysophosphatidic acid (LPA) is a phospholipid activating different biological functions by binding to G protein-coupled receptors (LPA1-6). Among these, the role of the LPA1 receptor in modulating fibrotic processes is well-known, making it a therapeutic target for pulmonary fibrosis and other fibrotic disorders. Herein we report the search for a new class of LPA1 antagonists for the oral treatment of idiopathic pulmonary fibrosis with a focus on hepatobiliary safety. Compound 7 excelled in in vitro and in vivo efficacy, showing significant efficacy both in PD studies and in a rodent lung fibrosis model, with a promising in vitro hepatic safety profile. However, in a dose range finding (DRF) toxicity study, compound 7 did not ensure safety regarding potential hepatobiliary toxicity, leading to its development being halted.

FBR2 modulates ferroptosis via the SIRT3/p53 pathway to ameliorate pulmonary fibrosis

Background

Idiopathic Pulmonary Fibrosis (IPF), an interstitial lung disease of unknown etiology, remains incurable with current therapies, which fail to halt disease progression or restore lung function. However, Feibi Recipe No. 2 (FBR2), a clinically validated traditional Chinese medicine formula, exhibits potential as an IPF treatment.

Objective

This study aimed to investigate the regulatory effect of FBR2 on ferroptosis through the SIRT3/p53 pathway and its therapeutic potential in improving IPF.

Methods

Pulmonary fibrosis was induced in C57BL/6J mice by intratracheal instillation of Bleomycin (BLM), followed by FBR2 treatment via gavage. Assessments encompassed histopathology, ELISA for cytokine detection, IHC and Western blot for protein expression analysis, and qRT-PCR for gene expression quantification. Transmission electron microscopy (TEM) was used to observe mitochondrial morphology. The roles of Erastin and the SIRT3 inhibitor 3-TYP were also explored to elucidate FBR2's mechanisms of action.

Results

FBR2 treatment significantly mitigated BLM-induced lung injury in mice, as evidenced by improved body weight and survival rates, and reduced levels of inflammatory cytokines, including IL-6 and TNF-α. FBR2 decreased collagen deposition in lung tissue, as shown by Masson's staining and IHC detection of Col-I and α-SMA, confirming its anti-fibrotic effects. It also reduced iron and MDA levels in lung tissue, increased GSH-Px activity, improved mitochondrial morphology, and enhanced the expression of GPX4 and SLC7A11, indicating its ferroptosis-inhibitory capacity. Furthermore, FBR2 increased SIRT3 levels and suppressed p53 and its acetylated forms, promoting the translocation of p53 from the nucleus to the cytoplasm where it co-localized with SIRT3. The protective effects of FBR2 were reversed by Erastin, confirming the central role of ferroptosis in pulmonary fibrosis treatment. The use of 3-TYP further confirmed FBR2's intervention in ferroptosis and cellular senescence through the SIRT3/p53 pathway.

Conclusion

FBR2 shows therapeutic potential in a BLM-induced pulmonary fibrosis mouse model, with its effects mediated through modulation of the ferroptosis pathway via the SIRT3/p53 mechanism. This study provides novel evidence for the targeted treatment of IPF and offers further insights into its pathogenesis.

Contribution of cuproptosis and immune-related genes to idiopathic pulmonary fibrosis disease

Background

Idiopathic pulmonary fibrosis (IPF) is a degenerative respiratory condition characterized by significant mortality rates and a scarcity of available treatment alternatives. Cuproptosis, a novel form of copper-induced cell death, has garnered attention for its potential implications. The study aimed to explore the diagnostic value of cuproptosis-related hub genes in patients with IPF. Additionally, multiple bioinformatics analyses were employed to identify immune-related biomarkers associated with the diagnosis of IPF, offering valuable insights for future treatment strategies.

Methods

Four microarray datasets were selected from the Gene Expression Omnibus (GEO) collection for screening. Differentially expressed genes (DEGs) associated with IPF were analyzed. Additionally, weighted gene coexpression network analysis (WGCNA) was employed to identify the DEGs most associated with IPF. Ultimately, we analyzed five cuproptosis-related hub genes and assessed their diagnostic value for IPF in both the training and validation sets. Additionally, four immune-related hub genes were screened using a protein-protein interaction (PPI) network and evaluated through the receiver operating characteristic (ROC) curve. Lastly, single-cell RNA-seq was employed to further investigate differential gene distribution.

Results

We identified a total of 92 DEGs. Bioinformatics analysis highlighted five cuproptosis-related genes as candidate biomarkers, including three upregulated genes (CFH, STEAP1, and HDC) and two downregulated genes (NUDT16 and FMO5). The diagnostic accuracy of these five genes in the cohort was confirmed to be reliable. Additionally, we identified four immune-related hub genes that demonstrated strong diagnostic performance for IPF, with CXCL12 showing an AUROC of 0.90. We also examined the relationship between these four genes and immune cells. CXCL12 was significantly negatively associated with neutrophils, while CXCR2 was associated exclusively with neutrophils, consistent with our single-cell sequencing results. CTSG showed a primarily positive association with follicular helper T, and SPP1 was most strongly associated with macrophages. Finally, our single-cell sequencing data revealed that in patients with IPF, CXCL12 was highly expressed in the endothelial cell subset (ECs), while SPP1 exhibited high expression in multiple cellular populations. The expression of the CTSG showed statistically significant differences in monocyte macrophages.

Conclusion

The research methodically depicted the intricate interplay among five cuproptosis-related genes, four immune-related hub genes, and IPF, offering new ideas for diagnosing and treating patients with IPF.

Engineering Lipid Nanoparticles to Enhance Intracellular Delivery of Transforming Growth Factor-Beta siRNA (siTGF-β1) via Inhalation for Improving Pulmonary Fibrosis Post-Bleomycin Challenge

Background/Objectives: Transforming Growth Factor-beta (TGFβ1) plays a core role in the process of pulmonary fibrosis (PF). The progression of pulmonary fibrosis can be alleviated by siRNA-based inhibiting TGF-β1. However, the limitations of naked siRNA lead to the failure of achieving therapeutic effect. This study aimed to design lipid nanoparticles (LNPs) that can deliver siTGF-β1 to the lungs for therapeutic purposes. Methods: The cytotoxicity and transfection assay in vitro were used to screen ionizable lipids (ILs). Design of Experiments (DOE) was used to obtain novel LNPs that can enhance resistance to atomization shear forces. Meanwhile, the impact of LNPs encapsulating siTGF-β1 (siTGFβ1-LNPs) on PF was investigated. Results: When DLin-DMA-MC3 (MC3) was used as the ILs, the lipid phase ratio was MC3:DSPC:DMG-PEG2000:cholesterol = 50:10:3:37, and N/P = 3.25; the siTGFβ1-LNPs could be stably delivered to the lungs via converting the siTGFβ1-LNPs solution into an aerosol (atomization). In vitro experiments have confirmed that siTGFβ1-LNPs have high safety, high encapsulation, and can promote cellular uptake and endosomal escape. In addition, siTGFβ1-LNPs significantly reduced inflammatory infiltration and attenuated deposition of extracellular matrix (ECM) and protected the lung tissue from the toxicity of bleomycin (BLM) without causing systemic toxicity. Conclusions: The siTGFβ1-LNPs can be effectively delivered to the lungs, resulting in the silencing of TGF-β1 mRNA and the inhibition of the epithelial-mesenchymal transition pathway, thereby delaying the process of PF, which provides a new method for the treatment and intervention of PF.

The Comorbidity of Lung Cancer and ILD: A Review

Patients with interstitial lung disease (ILD) and especially with idiopathic pulmonary fibrosis(IPF) suffer from reduced survival expectation and risk of exacerbations. Lung cancer is a relevant comorbidity in ILD patients and associated with impaired survival.The most frequent ILD among patients with NSCLC (Non-small cell lung cancer) is idiopathic pulmonary fibrosis (IPF), which is associated with an greater decline in lung function and a higher risk of death.The prevalence of lung cancer in patients with ILD is up to 10% and in autopsy studies a prevalence up to 48% has been found.There are no guidelines for patients with lung cancer and ILD. Moreover, no adequate evidence is available.Therefore, we reviewed currently available literature to present an overview of the state of the art.In this review we focus on staging and treatment of the comorbidity of lung cancer and ILD.

Inhalable siRNA Targeting IL-11 Nanoparticles Significantly Inhibit Bleomycin-Induced Pulmonary Fibrosis

For idiopathic pulmonary fibrosis (IPF), interleukin 11 (IL-11) is a pivotal cytokine that stimulates the transformation of fibroblasts into myofibroblasts, thus accelerating the progression of pulmonary fibrosis. Here, we develop an innovative inhalable small interfering RNA (siRNA) delivery system termed PEI-GBZA, which demonstrates impressive efficiency in loading siIL-11 targeting IL-11 (siIL-11) and substantially suppresses the differentiation of fibroblasts into myofibroblasts and epithelial-mesenchymal transition (EMT), reduces neutrophil and macrophage recruitment, and ultimately relieves the established fibrotic lesions in the IPF model. PEI-GBZA is prepared by modifying low-molecular-weight polyethylenimine (PEI) with 4-guanidinobenzoic acid (GBZA). The resulting PEI-GBZA may effectively encapsulate siIL-11 through a variety of interactions such as hydrophobic, hydrogen bonding, and electrostatic interactions, creating stable carrier/siIL-11 nanoparticles (PEI-GBZA/siIL-11 NPs). Upon inhalation, PEI-GBZA/siIL-11 NPs demonstrate effective retention in fibrotic lesions, leading to a marked mitigation of disease progression in a bleomycin-induced pulmonary fibrosis model. Impressively, this inhalation therapy exhibits negligible systemic toxicity. This work provides a universal and noninvasive RNA therapeutic delivery platform that holds significant promise for respiratory diseases. The potential for clinical application of this platform is substantial, offering a frontier for the treatment of IPF and potentially other pulmonary disorders.

Human epididymis protein 4-annexin II binding promotes aberrant epithelial-fibroblast crosstalk in pulmonary fibrosis

Invasive lung myofibroblasts are the main cause of tissue remodeling in idiopathic pulmonary fibrosis (IPF). A key mechanism contributing to this important feature is aberrant crosstalk between the abnormal/injured lung epithelium and pulmonary fibroblasts. Here, we demonstrate that lungs from patients with IPF and from mice with bleomycin (BLM)-induced pulmonary fibrosis (PF) are characterized by the induction of human epididymis protein 4 (HE4) overexpression in epithelial cells. HE4 knockdown primarily in epithelial cells attenuates BLM-induced PF in mice, whereas the administration of recombinant mouse HE4 exacerbates fibrosis after BLM stimulation. Mechanistic analysis shows that HE4 and annexin II (ANXA2) specific binding enhances the profibrotic phenotype in epithelial cells, and directly promotes lung fibroblast activation, leading to aberrant epithelial-fibroblast crosstalk and the persistent myofibroblast phenotype. The HE4 and ANXA2 binding site is located after the 30th amino acid at the N terminus of the HE4 molecule. Finally, intratracheal administration of HE4 shRNA lentivirus protects mice against BLM-induced PF. These data suggest that HE4 can serve as a potential therapeutic target in the treatment of IPF.

Substrate stiffness dictates unique doxorubicin-induced senescence-associated secretory phenotypes and transcriptomic signatures in human pulmonary fibroblasts

Cells are subjected to dynamic mechanical environments which impart forces and induce cellular responses. In age-related conditions like pulmonary fibrosis, there is both an increase in tissue stiffness and an accumulation of senescent cells. While senescent cells produce a senescence-associated secretory phenotype (SASP), the impact of physical stimuli on both cellular senescence and the SASP is not well understood. Here, we show that mechanical tension, modeled using cell culture substrate rigidity, influences senescent cell markers like SA-β-gal and secretory phenotypes. Comparing human primary pulmonary fibroblasts (IMR-90) cultured on physiological (2 kPa), fibrotic (50 kPa), and plastic (approximately 3 GPa) substrates, followed by senescence induction using doxorubicin, we identified unique high-stiffness-driven secretory protein profiles using mass spectrometry and transcriptomic signatures, both showing an enrichment in collagen proteins. Consistently, clusters of p21 + cells are seen in fibrotic regions of bleomycin induced pulmonary fibrosis in mice. Computational meta-analysis of single-cell RNA sequencing datasets from human interstitial lung disease confirmed these stiffness SASP genes are highly expressed in disease fibroblasts and strongly correlate with mechanotransduction and senescence-related pathways. Thus, mechanical forces shape cell senescence and their secretory phenotypes.

PLAC8 attenuates pulmonary fibrosis and inhibits apoptosis of alveolar epithelial cells via facilitating autophagy

Idiopathic pulmonary fibrosis (IPF) is an irreversible lung condition that progresses over time, which ultimately results in respiratory failure and mortality. In this study, we found that PLAC8 was downregulated in the lungs of IPF patients based on GEO data, in bleomycin (BLM)-induced lungs of mice, and in primary murine alveolar epithelial type II (pmATII) cells and human lung epithelial cell A549 cells. Overexpression of PLAC8 facilitated autophagy and inhibited apoptosis of pmATII cells and A549 cells in vitro. Moreover, inhibition of autophagy or overexpression of p53 partially abolished the effects of PLAC8 on cell apoptosis. ATII cell-specific overexpression of PLAC8 alleviated BLM-induced pulmonary fibrosis in mice. Mechanistically, PLAC8 interacts with VCP-UFD1-NPLOC4 complex to promote p53 degradation and facilitate autophagy, resulting in inhibiting apoptosis of alveolar epithelial cells and attenuating pulmonary fibrosis. In summary, these findings indicate that PLAC8 may be a key target for therapeutic interventions in pulmonary fibrosis.

Targeting pleuro-alveolar junctions reverses lung fibrosis in mice

Lung fibrosis development utilizes alveolar macrophages, with mechanisms that are incompletely understood. Here, we fate map connective tissue during mouse lung fibrosis and observe disassembly and transfer of connective tissue macromolecules from pleuro-alveolar junctions (PAJs) into deep lung tissue, to activate fibroblasts and fibrosis. Disassembly and transfer of PAJ macromolecules into deep lung tissue occurs by alveolar macrophages, activating cysteine-type proteolysis on pleural mesothelium. The PAJ niche and the disassembly cascade is active in patient lung biopsies, persists in chronic fibrosis models, and wanes down in acute fibrosis models. Pleural-specific viral therapeutic carrying the cysteine protease inhibitor Cystatin A shuts down PAJ disassembly, reverses fibrosis and regenerates chronic fibrotic lungs. Targeting PAJ disassembly by targeting the pleura may provide a unique therapeutic avenue to treat lung fibrotic diseases.

Regenerative Capacity of Alveolar Type 2 Cells Is Proportionally Reduced Following Disease Progression in Idiopathic Pulmonary Fibrosis-Derived Organoid Cultures

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease that culminates in respiratory failure and death due to irreversible scarring of the distal lung. While initially considered a chronic inflammatory disorder, the aberrant function of the alveolar epithelium is now acknowledged as playing a central role in the pathophysiology of IPF. This study aimed to investigate the regenerative capacity of alveolar type 2 (AT2) cells using IPF-derived alveolar organoids and to examine the effects of disease progression on this capacity.

METHODS

Lung tissues from three pneumothorax patients and six IPF patients (early and advanced stages) were obtained through video-assisted thoracoscopic surgery and lung transplantation. HTII-280+ cells were isolated from CD31-CD45-epithelial cell adhesion molecule (EpCAM)+ cells in the distal lungs of IPF and pneumothorax patients using fluorescence-activated cell sorting (FACS) and resuspended in 48-well plates to establish IPF-derived alveolar organoids. Immunostaining was used to verify the presence of AT2 cells.

RESULTS

FACS sorting yielded approximately 1% of AT2 cells in early IPF tissue, and the number decreased as the disease progressed, in contrast to 2.7% in pneumothorax. Additionally, the cultured organoids in the IPF groups were smaller and less numerous compared to those from pneumothorax patients. The colony forming efficiency decreased as the disease advanced. Immunostaining results showed that the IPF organoids expressed less surfactant protein C (SFTPC) compared to the pneumothorax group and contained keratin 5+ (KRT5+) cells.

CONCLUSION

This study confirmed that the regenerative capacity of AT2 cells in IPF decreases as the disease progresses, with IPF-derived AT2 cells inherently exhibiting functional abnormalities and altered differentiation plasticity.

Idiopathic Pulmonary Fibrosis Is Associated With Type 1 Diabetes: A Two-Sample Mendelian Randomization Study

BACKGROUND

The pathogenesis of idiopathic pulmonary fibrosis (IPF) remains unclear; previous studies revealed the underlying connection between IPF and diabetes, but there is no consensual opinion. This study is aimed at examining the association between Type 1 diabetes (T1D) and IPF using Mendelian randomization (MR).

METHOD

In our two-sample MR study, we selected single nucleotide polymorphisms (SNPs) that are strongly associated with T1D in a genome-wide association study (GWAS) from IEU (dataset: ebi-a-GCST005536) and obtained their corresponding effect estimates on T1D risk in an IPF GWAS from IEU (dataset: finn-b-IPF). We conducted a multivariable Mendelian randomization (MVMR) analysis to eliminate the interference of aging.

RESULT

In the outcome of inverse-variance weighted (IVW) method, T1D showed a promoting effect on IPF (odds ratio (OR): 1.132, p = 0.005). The statistics passed the MR-PRESSO test, and no outliers were observed (global test p = 0.238). MVMR study was performed, and the aging-adjusted result remains almost the same (OR = 1.132, OR_95% CI: 1.034-1.239, p = 0.007).

CONCLUSION

Our study shows a causal relation between T1D and IPF; further investigation should be conducted.

ANGPTL4 mediated mesothelial-mesenchymal transition in pulmonary fibrosis: a potential therapeutic target

BACKGROUND

Glycolysis plays a major role in progression of idiopathic pulmonary fibrosis (IPF). Here, we aim to explore the predictive signature based on glycolysis-related genes for predicting the prognosis and identified a potential therapeutic target for IPF.

METHODS

Gene expression data of bronchoalveolar lavage (BAL) cells and clinical information were downloaded from the Gene Expression Omnibus database. Bioinformatic analysis was then performed to identify differentially expressed genes (DEGs). Lasso multivariate cox analysis and multivariate Cox regression were used to establish a gene signature. The prediction model was evaluated using the time-dependent receiver operating characteristic (ROC) curve and validated using an external independent dataset. The expression of these key genes in cellular level analyzed from Single Cell Expression Atlas. Cell Counting Kit-8 assay, immunofluorescence, wound healing and plasmid transfection were performed.

RESULTS

A total of 4 gene (ANGPTL4, ME2, TPBG and IER3), which were associated with the prognosis of IPF patients, were selected to establish our signature. The prediction model was an independent prognostic indicator for IPF patients. ANGPTL4 was significantly upregulated in pleural mesothelial cells (PMCs). In vitro assay showed that ANGPTL4 promoted PMCs proliferation and migration. Knockdown of ANGPTL4 can inhibit mesothelial-mesenchymal transition by suppressed glycolysis-associated gene, such as PGM1, GPI, PGK1, LDHA, ALDOA, ENO1 and TPI1.

CONCLUSIONS

Our research established a glycolysis-associated gene signature that holds potential to assist clinicians in the personalized management of IPF. Furthermore, we identified that ANGPTL4 mediates mesothelial-mesenchymal transition, suggesting its viability as a therapeutic target for IPF treatment.

Prevalence and clinical features of interstitial lung disease in patients with psoriasis

BACKGROUND

Despite the autoimmune nature of psoriasis, the potential association between psoriasis and interstitial lung disease (ILD) remains underexplored. This study aimed to investigate the frequency and clinical features of ILD in patients with psoriasis and propose a new conceptual framework of "ILD associated with psoriasis".

METHODS

A retrospective analysis of 117 patients with psoriasis was conducted, excluding those without chest imaging prior to methotrexate or biologic use and those with other comorbidities leading to ILD.

RESULTS

ILD was identified in 12 (10%) patients with psoriasis; 6/50 with psoriasis vulgaris and 6/65 with psoriatic arthritis. Three of 12 patients had no history of smoking. Serum Krebs von den Lungen-6 (KL-6) levels were elevated in patients with ILD compared to those in patients without ILD. The indeterminate for usual interstitial pneumonia (UIP) pattern was the most prevalent CT finding. A lung biopsy specimen from a representative case revealed equivalent indeterminate for UIP. Over a median 8.9-year observation period, ILD progressed in only 5 patients, with no cases of respiratory failure or death due to ILD progression, suggesting generally favourable prognoses.

CONCLUSIONS

ILD associated with psoriasis would be present, and its frequency is 10% of patients with psoriasis. We propose that chest radiography and a serum KL-6 test at the initial diagnosis of psoriasis would be useful in screening for the detection of ILD. We also recommend that a physician diagnosing ILD should carefully examine the skin findings, considering if psoriasis could be associated with ILD.

TRIAL REGISTRATION

Not applicable.

Stage-Dependent Fibrotic Gene Profiling of WISP1-Mediated Fibrogenesis in Human Fibroblasts

Idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung disease with unknown etiology, characterized by chronic inflammation and tissue scarring. Although, Pirfenidone and Nintedanib slow the disease progression, no currently available drugs or therapeutic interventions address the underlying cause, highlighting the unmet medical need. A matricellular protein, Wnt-1-induced secreted protein 1 (WISP1), also referred to as CCN4 (cellular communication network factor 4), is a secreted multi-modular protein implicated in multi-organ fibrosis. Although the precise mechanism of WISP1-mediated fibrosis remains unclear, emerging evidence indicates that WISP1 is profibrotic in nature. While WISP1-targeting therapy is applied in the clinic for fibrosis, detailed interrogation of WISP1-mediated fibrogenic molecular and biological pathways is lacking. Here, for the first time, using NanoString® technology, we identified a novel WISP1-associated profibrotic gene signature and molecular pathways potentially involved in the initiation and progression of fibrosis in primary human dermal and lung fibroblasts from both healthy individuals and IPF patients. Our data demonstrate that WISP1 is upregulated in IPF-lung fibroblasts as compared to healthy control. Furthermore, our results confirm that WISP1 is downstream of the transforming growth factor-β (TGFβ), and it induces fibroblast cell proliferation. Additionally, WISP1 induced IL6 and CCL2 in fibroblasts. We also developed a novel, combined TGFβ and WISP1 in vitro system to demonstrate a role for WISP1 in the progression of fibrosis. Overall, our findings uncover not only similarities but also striking differences in the molecular profile of WISP1 in human fibroblasts, both during the initiation and progression phases, as well as in disease-specific context.

Anti-Inflammatory Effects of Aptamin C in Pulmonary Fibrosis Induced by Bleomycin

Background/Objectives: Vitamin C is a well-known antioxidant with antiviral, anticancer, and anti-inflammatory properties. However, its therapeutic applications are limited by rapid oxidation due to heat and light sensitivity. Aptamin C, which employs aptamers to bind vitamin C, has demonstrated enhanced stability and efficacy. This study investigates the potential of Aptamin C to inhibit the progression of pulmonary fibrosis, a prominent inflammatory lung disease with no effective treatment. Methods: Mice bearing bleomycin-induced pulmonary fibrosis were administered vitamin C or Aptamin C, and their weight changes and survival rates were monitored. Inflammatory cell infiltration was assessed in the bronchoalveolar lavage fluid (BALF), and the degree of alveolar fibrosis was measured by H&E and Masson's trichrome staining. To elucidate the mechanism of action of Aptamin C, Western blot analysis was performed in HaCaT and lung tissues from bleomycin-induced pulmonary fibrosis mice. Results: The Aptamin C-treated group showed a notably higher survival rate at 50%, whereas all subjects in the vitamin C-treated group died. Histological examination of lung tissue showed that inflammation was significantly suppressed in the Aptamin C-supplemented group compared to the vitamin C-supplemented group, with a 10% greater reduction in cell infiltrations, along with noticeably less tissue damage. Additionally, it was observed that Aptamin C increased SVCT-1 expression in the HaCaT cells and the lung tissues. Conclusions: Taken together, Aptamin C not only increases the stability of vitamin C but also induces an increase in SVCT-1 expression, facilitating greater vitamin C absorption into cells and tissues, thereby inhibiting the progression of symptoms and associated inflammatory responses in pulmonary fibrosis.

Substrate Stiffness Dictates Unique Doxorubicin-induced Senescence-associated Secretory Phenotypes and Transcriptomic Signatures in Human Pulmonary Fibroblasts

Cells are subjected to dynamic mechanical environments which impart forces and induce cellular responses. In age-related conditions like pulmonary fibrosis, there is both an increase in tissue stiffness and an accumulation of senescent cells. While senescent cells produce a senescence-associated secretory phenotype (SASP), the impact of physical stimuli on both cellular senescence and the SASP is not well understood. Here, we show that mechanical tension, modeled using cell culture substrate rigidity, influences senescent cell markers like SA-β-gal and secretory phenotypes. Comparing human primary pulmonary fibroblasts (IMR-90) cultured on physiological (2 kPa), fibrotic (50 kPa), and plastic (approximately 3 GPa) substrates, followed by senescence induction using doxorubicin, we identified unique high-stiffness-driven secretory protein profiles using mass spectrometry and transcriptomic signatures, both showing an enrichment in collagen proteins. Consistently, clusters of p21+ cells are seen in fibrotic regions of bleomycin induced pulmonary fibrosis in mice. Computational meta-analysis of single-cell RNA sequencing datasets from human interstitial lung disease confirmed these stiffness SASP genes are highly expressed in disease fibroblasts and strongly correlate with mechanotransduction and senescence-related pathways. Thus, mechanical forces shape cell senescence and their secretory phenotypes.

Triangle correlations of lung microbiome, host physiology and gut microbiome in a rat model of idiopathic pulmonary fibrosis

Changes in lung and gut microbial communities have been associated with idiopathic pulmonary fibrosis (IPF). This study aimed to investigate correlations between microbial changes in the lung and gut and host physiological indices in an IPF model, exploring potential mechanisms of the lung-gut axis in IPF pathogenesis. IPF model rats were established via trans-tracheal injection of bleomycin, with assessments of hematological indices, serum cytokines, lung histopathology, and microbiome alterations. Significant differences in microbial structure and composition were observed in the IPF model compared to controls, with 14 lung and 7 gut microbial genera showing significant abundance changes. Further analysis revealed 20 significant correlations between pulmonary and gut genera. Notably, 11 pairs of correlated genera were linked to the same IPF-related physiological indices, such as hydroxyproline, mean corpuscular volume (MCV), and red cell distribution width-standard deviation (RDW-SD). We identified 24 instances where a lung and a gut genus were each associated with the same physiological index, forming "lung genus-index-gut genus" relationships. Mediation analysis showed that indices like hydroxyproline, MCV, and RDW-SD mediated correlations between 10 lung genera (e.g., Cetobacterium, Clostridium XVIII ) and the gut genus Allobaculum. This study first describes gut-lung microbial interactions in pulmonary fibrosis. Mediation analysis suggests pathways underlying "lung genus-host index-gut genus" and "gut genus-host index-lung genus" correlations, thus providing clues to further elucidate the mechanisms of the "gut-lung axis" in IPF pathogenesis.

Development and Evaluation of ABI-171, a New Fluoro-Catechin Derivative, for the Treatment of Idiopathic Pulmonary Fibrosis

The persistent challenge of idiopathic pulmonary fibrosis (IPF), characterized by disease progression and high mortality, underscores the urgent need for innovative therapeutic strategies. We have developed a novel small molecule-catechin derivative ABI-171-selectively targeting dual-specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A) and proviral integration site for Moloney murine leukemia virus 1 (PIM1) kinases, crucial in the pathogenesis of fibrotic processes. We employed the Bleomycin-induced (intratracheal) mouse model of pulmonary fibrosis (PF) to evaluate the therapeutic efficacy of ABI-171. Mice with induced PF were treated QD with ABI-171, either prophylactically or therapeutically, using oral and intranasal routes. Pirfenidone (100 mg/kg, TID) and Epigallocatechin gallate (EGCG, 100 mg/kg, QD), a natural catechin currently in a Phase 1 clinical trial, were used as reference compounds. ABI-171, administered prophylactically, led to a significant reduction in hydroxyproline levels and fibrotic tissue formation compared to the control group. Treatment with ABI-171 improved body weight, indicating mitigation of disease-related weight loss. Additionally, ABI-171 demonstrated anti-inflammatory activity, reducing lymphocyte and neutrophil infiltration. In the therapeutic setting, ABI-171, administered 7 days post-induction, reduced mortality rates (p = 0.04) compared with the bleomycin and EGCG control groups. ABI-171 also ameliorated the severity of lung injuries assessed by improved Masson's trichrome scores when administered both orally and intranasally. ABI-171 significantly decreases bleomycin-induced PF and improves survival in mice, showcasing promising therapeutic potential beyond current medications like pirfenidone and EGCG for patients with IPF. Based on these results, further studies with ABI-171 are ongoing in preclinical studies.

Interaction between CD244 and SHP2 regulates inflammation in chronic obstructive pulmonary disease via targeting the MAPK/NF-κB signaling pathway

This study delved into the interplay between CD244 and Src Homology 2 Domain Containing Phosphatase-2 (SHP2) in chronic obstructive pulmonary disease (COPD) pathogenesis, focusing on apoptosis and inflammation in cigarette smoke extract (CSE)-treated human bronchial epithelial (HBE) cells. Analysis of the GSE100153 dataset identified 290 up-regulated and 344 down-regulated differentially expressed genes (DEGs). Weighted gene co-expression network analysis (WGCNA) highlighted the turquoise module had the highest correlation with COPD samples. Functional enrichment analysis linked these DEGs to critical COPD processes and pathways like neutrophil degranulation, protein kinase B activity, and diabetic cardiomyopathy. Observations on CD244 expression revealed its upregulation with increasing CSE concentrations, suggesting a dose-dependent relationship with inflammatory cytokines (IL-6, IL-8, TNF-α). CD244 knockdown mitigated CSE-induced apoptosis and inflammation, while overexpression exacerbated these responses. Co-immunoprecipitation (Co-IP) confirmed the physical interaction between CD244 and SHP2, emphasizing their regulatory connection. Analysis of Concurrently, the Nuclear Factor-kappa B (NF-κB) and Mitogen-activated protein kinase (MAPK) signaling pathways showed that modulating CD244 expression impacted key pathway components (p-JNK, p-IKKβ, p-ERK, p-P38, p-lkBα, p-P65), an effect reversed upon SHP2 knockdown. These findings underscore the pivotal role of the CD244/SHP2 axis in regulating inflammatory and apoptotic responses in CSE-exposed HBE cells, suggesting its potential as a therapeutic target in COPD treatment strategies.

Novel Small-Molecule ROCK2 Inhibitor GNS-3595 Attenuates Pulmonary Fibrosis in Preclinical Studies

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease that leads to respiratory decline caused by scarring and thickening of lung tissues. Multiple pathways contribute to the fibrotic process in this disease, such as inflammation, epithelial-to-mesenchymal transition, and oxidative stress. The Rho-associated coiled-coil forming protein kinase (ROCK) signaling pathway is a key regulator of profibrotic signaling, as it affects the organization of actin-myosin and the remodeling of the extracellular matrix. ROCK1/2, a downstream effector of RhoA, is overexpressed in patients with IPF and is a promising target for IPF therapy. However, because of the hypotensive side effects of ROCK1/2 inhibitors, selective ROCK2 compounds are being explored. In this study, we report the discovery of GNS-3595, a potent and selective ROCK2 inhibitor that has ∼80-fold selectivity over ROCK1 at physiological concentrations of ATP. GNS-3595 effectively inhibited ROCK2-mediated phosphorylation of myosin light chain and reduced the expression of fibrosis-related proteins (e.g., collagen, fibronectin, and α-smooth muscle actin) in various in vitro cellular models. GNS-3595 also prevented transforming growth factor β-induced fibroblast-to-myofibroblast transition. In addition, in a bleomycin-induced mouse model of pulmonary fibrosis, therapeutic exposure to GNS-3595, suppressed lung fibrosis, stabilized body weight loss, and prevented fibrosis-induced lung weight gain. Transcriptome and protein expression analysis from lung tissues showed that GNS-3595 can revert the fibrosis-related gene expression induced by bleomycin. These results indicate that GNS-3595 is a highly potent, selective, and orally active ROCK2 inhibitor with promising therapeutic efficacy against pulmonary fibrosis.

Updates on the controversial roles of regulatory lymphoid cells in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most common and severe form of pulmonary fibrosis, characterized by scar formation in the lung interstitium. Transforming growth factor beta (TGF-β) is known as a key mediator in the fibrotic process, acting on fibroblasts and mediating their proliferation and differentiation into myofibroblasts. Although the immune system is not considered responsible for the initiation of IPF, markers of tolerogenic immunity define the pro-fibrotic microenvironment in the lungs. In homeostatic conditions, regulatory T cells (Tregs) constitute the main lymphoid population responsible for maintaining peripheral tolerance. Similar to Tregs, regulatory B cells (Bregs) represent a recently described subset of B lymphocytes with immunosuppressive functions. In the context of IPF, numerous studies have suggested a role for Tregs in enhancing fibrosis, mainly via the secretion of TGF-β. In humans, most studies show increased percentages of Tregs associated with the severity of IPF, although their exact role remains unclear. In mice, the most commonly used model involves triggering acute lung inflammation with bleomycin, leading to a subsequent fibrotic process. Consequently, data are still conflicting, as Tregs may play a protective role during the inflammatory phase and a deleterious role during the fibrotic phase. Bregs have been less studied in the context of IPF, but their role appears to be protective in experimental models of lung fibrosis. This review presents the latest updates on studies exploring the implication of regulatory lymphoid cells in IPF and compares the different approaches to better understand the origins of conflicting findings.

Molecular mechanism of Dang-Shen-Yu-Xing decoction against Mycoplasma bovis pneumonia based on network pharmacology, molecular docking, molecular dynamics simulations and experimental verification

Mycoplasma bovis pneumonia is a highly contagious respiratory infection caused by Mycoplasma bovis. It is particularly prevalent in calves, posing a significant threat to animal health and leading to substantial economic losses. Dang-Shen-Yu-Xing decoction is often used to treat this condition in veterinary clinics. It exhibits robust anti-inflammatory effects and can alleviate pulmonary fibrosis. However, its mechanism of action remains unclear. Therefore, this study aimed to preliminarily explore the molecular mechanism of Dang-Shen-Yu-Xing decoction for treating mycoplasma pneumonia in calves through a combination of network pharmacology, molecular docking, molecular dynamics simulation methods, and experimental validation. The active components and related targets of Dang-Shen-Yu-Xing decoction were extracted from several public databases. Additionally, complex interactions between drugs and targets were explored through network topology, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. Subsequently, the binding affinity of drug to disease-related targets was verified through molecular docking and molecular dynamics simulation. Finally, the pharmacodynamics were verified via animal experiments. The primary network topology analysis revealed two core targets and 10 key active components of Dang-Shen-Yu-Xing decoction against Mycoplasma bovis pneumonia. Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that the mechanism of Dang-Shen-Yu-Xing decoction for treating mycoplasma bovis pneumonia involved multiple signaling pathways, with the main pathways including PI3K-Akt and IL17 signaling pathways. Moreover, molecular docking predicted the binding affinity and conformation of the core targets of Dang-Shen-Yu-Xing decoction, IL6, and IL10, with the associated main active ingredients. The results showed a strong binding of the active ingredients to the hub target. Further, molecular docking dynamics simulation revealed three key active components of IL10 induced by Dang-Shen-Yu-Xing decoction against Mycoplasma bovis pneumonia. Finally, animal experiments confirmed Dang-Shen-Yu-Xing decoction pharmacodynamics, suggesting that it holds potential as an alternative therapy for treating mycoplasma bovis pneumonia.

Causal relationship between circulating glutamine levels and idiopathic pulmonary fibrosis: a two-sample mendelian randomization study

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive and debilitating respiratory disease with a median survival of less than 5 years. In recent years, glutamine has been reported to be involved in the regulation of collagen deposition and cell proliferation in fibroblasts, thereby influencing the progression of IPF. However, the relationships between glutamine and the incidence, progression, and treatment response of IPF remain unclear. Our study aimed to investigate the relationship between circulating glutamine levels and IPF, as well as its potential as a therapeutic target.

METHODS

We performed a comprehensive Mendelian Randomization (MR) analysis using the most recent genome-wide association study summary-level data. A total of 32 single nucleotide polymorphisms significantly correlated to glutamine levels were identified as instrumental variables. Eight MR analysis methods, including inverse variance weighted, MR-Egger, weighted median, weighted mode, constrained maximum likelihood, contamination mixture, robust adjusted profile score, and debiased inverse-variance weighted method, were used to assess the relationship between glutamine levels with IPF.

RESULTS

The inverse variance weighted analysis revealed a significant inverse correlation between glutamine levels and IPF risk (Odds Ratio = 0.750; 95% Confidence Interval : 0.592-0.951; P = 0.017). Sensitivity analyses, including MR-Egger regression and MR-PRESSO global test, confirmed the robustness of our findings, with no evidence of horizontal pleiotropy or heterogeneity.

CONCLUSION

Our study provides novel evidence for a causal relationship between lower circulating glutamine levels and increased risk of IPF. This finding may contribute to the early identification of high-risk individuals for IPF, disease monitoring, and development of targeted therapeutic strategies.

Role of telomere dysfunction and immune infiltration in idiopathic pulmonary fibrosis: new insights from bioinformatics analysis

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease characterized by unexplained irreversible pulmonary fibrosis. Although the etiology of IPF is unclear, studies have shown that it is related to telomere length shortening. However, the prognostic value of telomere-related genes in IPF has not been investigated.

Methods

We utilized the GSE10667 and GSE110147 datasets as the training set, employing differential expression analysis and weighted gene co-expression network analysis (WGCNA) to screen for disease candidate genes. Then, we used consensus clustering analysis to identify different telomere patterns. Next, we used summary data-based mendelian randomization (SMR) analysis to screen core genes. We further evaluated the relationship between core genes and overall survival and lung function in IPF patients. Finally, we performed immune infiltration analysis to reveal the changes in the immune microenvironment of IPF.

Results

Through differential expression analysis and WGCNA, we identified 35 significant telomere regulatory factors. Consensus clustering analysis revealed two distinct telomere patterns, consisting of cluster A (n = 26) and cluster B (n = 19). Immune infiltration analysis revealed that cluster B had a more active immune microenvironment, suggesting its potential association with IPF. Using GTEx eQTL data, our SMR analysis identified two genes with potential causal associations with IPF, including GPA33 (PSMR = 0.0013; PHEIDI = 0.0741) and MICA (PSMR = 0.0112; PHEIDI = 0.9712). We further revealed that the expression of core genes is associated with survival time and lung function in IPF patients. Finally, immune infiltration analysis revealed that NK cells were downregulated and plasma cells and memory B cells were upregulated in IPF. Further correlation analysis showed that GPA33 expression was positively correlated with NK cells and negatively correlated with plasma cells and memory B cells.

Conclusion

Our study provides a new perspective for the role of telomere dysfunction and immune infiltration in IPF and identifies potential therapeutic targets. Further research may reveal how core genes affect cell function and disease progression, providing new insights into the complex mechanisms of IPF.

Cepharanthine attenuates pulmonary fibrosis via modulating macrophage M2 polarization

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a group of chronic interstitial pulmonary diseases characterized by myofibroblast proliferation and extracellular matrix (ECM) deposition. However, current treatments are not satisfactory. Therefore, more effective therapies need to be explored. Cepharanthine (CEP) is a naturally occurring alkaloid that has recently been reported to have multiple pharmacological effects, particularly in chronic inflammation.

METHODS

For in vivo experiments, first, a pulmonary fibrosis murine model was generated via tracheal injection of bleomycin (BLM). Second, the clinical manifestations and histopathological changes of the mice were used to verify that treatment with CEP might significantly reduce BLM-induced fibrosis. Furthermore, flow cytometric analysis was used to analyze the changes in the number of M2 macrophages in the lung tissues before and after treatment with CEP to explore the relationship between macrophage M2 polarization and pulmonary fibrosis. In vitro, we constructed two co-culture systems (THP-1 and MRC5 cells, RAW264.7 and NIH 3T3 cells), and measured the expression of fibrosis-related proteins to explore whether CEP could reduce pulmonary fibrosis by regulating macrophage M2 polarization and fibroblast activation.

RESULTS

The results showed that the intranasal treatment of CEP significantly attenuated the symptoms of pulmonary fibrosis induced by BLM in a murine model. Our findings also indicated that CEP treatment markedly reduced the expression of fibrosis markers, including TGF-β1, collagen I, fibronectin and α-SMA, in the mouse lung. Furthermore, in vitro studies demonstrated that CEP attenuated pulmonary fibrosis by inhibiting fibroblast activation through modulating macrophage M2 polarization and reducing TGF-β1 expression.

CONCLUSIONS

This study demonstrated the potential and efficacy of CEP in the treatment of pulmonary fibrosis. In particular, this study revealed a novel mechanism of CEP in inhibiting fibroblast activation by regulating macrophage M2 polarization and reducing the expression of fibrosis-associated factors. Our findings open a new direction for future research into the treatment of pulmonary fibrosis.

YAP/TAZ Signaling in the Pathobiology of Pulmonary Fibrosis

Pulmonary fibrosis (PF) is a severe, irreversible lung disease characterized by progressive scarring, with idiopathic pulmonary fibrosis (IPF) being the most prevalent form. IPF's pathogenesis involves repetitive lung epithelial injury leading to fibroblast activation and excessive extracellular matrix (ECM) deposition. The prognosis for IPF is poor, with limited therapeutic options like nintedanib and pirfenidone offering only modest benefits. Emerging research highlights the dysregulation of the yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) signaling pathway as a critical factor in PF. YAP and TAZ, components of the Hippo pathway, play significant roles in cell proliferation, differentiation, and fibrosis by modulating gene expression through interactions with TEA domain (TEAD) transcription factors. The aberrant activation of YAP/TAZ in lung tissue promotes fibroblast activation and ECM accumulation. Targeting the YAP/TAZ pathway offers a promising therapeutic avenue. Preclinical studies have identified potential treatments, such as trigonelline, dopamine receptor D1 (DRD1) agonists, and statins, which inhibit YAP/TAZ activity and demonstrate antifibrotic effects. These findings underscore the importance of YAP/TAZ in PF pathogenesis and the potential of novel therapies aimed at this pathway, suggesting a new direction for improving IPF treatment outcomes. Further research is needed to validate these approaches and translate them into clinical practice.

The association between testosterone, estradiol, estrogen sulfotransferase and idiopathic pulmonary fibrosis: a bidirectional mendelian randomization study

BACKGROUND

The causal relationships between testosterone, estradiol, estrogen sulfotransferase, and idiopathic pulmonary fibrosis (IPF) are not well understood. This study employs a bidirectional two-sample Mendelian Randomization (MR) approach to explore these associations.

METHODS

All genetic data utilized in our study were obtained from the IEU Open GWAS project. For the MR analysis, we employed the inverse variance weighted (IVW), MR-Egger, and weighted median methods to assess the causal relationships. We also conducted a multivariate MR (MVMR) analysis, with adjustments made for smoking. To ensure the robustness of our findings, sensitivity analyses were conducted using Cochran's Q test, MR-Egger regression, the MR-PRESSO global test, and the leave-one-out method.

RESULTS

Genetically predicted increases in serum testosterone levels by one standard deviation were associated with a 58.7% decrease in the risk of developing IPF (OR = 0.413, PIVW=0.029, 95% CI = 0.187 ∼ 0.912), while an increase in serum estrogen sulfotransferase by one standard deviation was associated with a 32.4% increase in risk (OR = 1.324, PIVW=0.006, 95% CI = 1.083 ∼ 1.618). No causal relationship was found between estradiol (OR = 1.094, PIVW=0.735, 95% CI = 0.650 ∼ 1.841) and the risk of IPF. Reverse MR analysis did not reveal any causal relationship between IPF and testosterone (OR = 1.001, PIVW=0.51, 95% CI = 0.998 ∼ 1.004), estradiol (OR = 1.001, PIVW=0.958, 95% CI = 0.982 ∼ 1.019), or estrogen sulfotransferase (OR = 0.975, PIVW=0.251, 95% CI = 0.933 ∼ 1.018). The MVMR analysis demonstrated that the association between testosterone (OR = 0.442, P = 0.037, 95% CI = 0.205 ∼ 0.953) and estrogen sulfotransferase (OR = 1.314, P = 0.001, 95% CI = 1.118 ∼ 1.545) and the risk of IPF persisted even after adjusting for smoking.

CONCLUSIONS

Increased serum levels of testosterone are associated with a reduced risk of IPF, while increased levels of serum estrogen sulfotransferase are associated with an increased risk. No causal relationship was found between estradiol and the development of IPF. No causal relationship was identified between IPF and testosterone, estradiol, or estrogen sulfotransferase.

Cellular and Molecular Genetic Mechanisms of Lung Fibrosis Development and the Role of Vitamin D: A Review

Idiopathic pulmonary fibrosis remains a relevant problem of the healthcare system with an unfavorable prognosis for patients due to progressive fibrous remodeling of the pulmonary parenchyma. Starting with the damage of the epithelial lining of alveoli, pulmonary fibrosis is implemented through a cascade of complex mechanisms, the crucial of which is the TGF-β/SMAD-mediated pathway, involving various cell populations. Considering that a number of the available drugs (pirfenidone and nintedanib) have only limited effectiveness in slowing the progression of fibrosis, the search and justification of new approaches aimed at regulating the immune response, cellular aging processes, programmed cell death, and transdifferentiation of cell populations remains relevant. This literature review presents the key modern concepts concerning molecular genetics and cellular mechanisms of lung fibrosis development, based mainly on in vitro and in vivo studies in experimental models of bleomycin-induced pulmonary fibrosis, as well as the latest data on metabolic features, potential targets, and effects of vitamin D and its metabolites.