Saracatinib, a Selective Src Kinase Inhibitor, Blocks Fibrotic Responses in Preclinical Models of Pulmonary Fibrosis

Discovery of potent anti-idiopathic pulmonary fibrosis (IPF) agents based on an o-aminopyridinyl alkynyl scaffold

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease with high mortality and limited treatment options. Targeting multiple kinase-driven pathological processes offers a promising strategy. Using epithelial-mesenchymal transition (EMT) phenotypic screening, we optimized a series of o-aminopyridinyl alkynyl compounds derived from CSF-1R relatively selective inhibitor, compound 1, through a structure-activity relationship (SAR) study, integrating liver and kidney cytotoxicity evaluations. Compound 22, emerged as the potent antifibrotic candidate, exhibiting low cytotoxic effects against human kidney (HEK293) and hepatocyte (L02) cell lines, and minimal hERG inhibition. In addition, 22 showed significant inhibition against other IPF-related processes, including fibroblast-to-myofibroblast transition (FMT)-driven fibrosis in both human fetal lung fibroblasts cell line (HFL1) and primary human lung fibroblasts (HLFs), as well as pro-fibrotic M2 polarization. In vivo, compound 22 exhibited the acceptable PK properties and low toxicity profiles. In addition, oral administration of 22 demonstrated superior anti-fibrotic efficacy compared to Nintedanib, significantly attenuating bleomycin-induced lung fibrosis, reducing inflammation and pro-fibrotic M2-associated cytokine levels, and improving lung function. Preliminary kinase profiling indicates that compound 22 likely targets CSF-1R, PDGFR-α and Src family kinases to inhibit IPF progression, while sparing VEGFRs, FGFRs and Abl to minimize off-target toxicity commonly associated with multi-kinase inhibitor treatment. These findings highlight the advantages and therapeutic potential of a multi-kinase targeting strategy, enabling selective inhibition key IPF-associated kinases to develop more effective and safer anti-IPF agents.

Omentin-1 attenuates atrial fibrillation via Src/PI3K/Akt signaling-mediated anti-fibrotic effects in cardiac fibroblasts

BACKGROUND

Atrial fibrillation (AF) is characterized by progressive atrial fibrosis, leading to increased morbidity and mortality. While the novel adipokine Omentin-1 demonstrates anti-fibrotic potential across organ systems, its role in AF pathogenesis remains unclear. This study investigates Omentin-1's therapeutic effects and the underlying mechanisms in angiotensin II (Ang II)-induced atrial fibrosis and AF.

METHODS

Atrial fibrosis was induced in C57BL/6 mice via continuous Ang II infusion for 4 weeks. Omentin-1 overexpression was achieved using adeno-associated virus serotype 2/9 (AAV2/9). AF susceptibility was assessed by programmed electrical stimulation, and atrial fibrosis was quantified using histological staining and Western blot analysis. Immunofluorescence co-localization assessed cell-type specific expression of Omentin-1, and proteomic analysis of atrial fibroblasts was conducted to explore molecular pathways involved. In vitro studies using primary fibroblasts were conducted to validate Omentin-1's effects.

RESULTS

Omentin-1 levels were significantly decreased in both serum and atrial tissue of Ang II-treated mice. Omentin-1 overexpression reduced AF inducibility, decreased atrial fibrosis, and improved left atrial strain parameters. Immunofluorescence showed that Omentin-1 predominantly localized to atrial fibroblasts. Mechanistically, Omentin-1 regulated collagen metabolism by targeting fibroblasts, with Src kinase acting as a critical mediator of fibroblast activation through the PI3K/Akt signaling pathway.

CONCLUSION

Omentin-1 attenuates atrial fibrosis and AF susceptibility through regulation of the Src/PI3K/Akt signaling pathway in atrial fibroblasts. These findings suggest that Omentin-1 may represent a potential therapeutic target for the prevention and treatment of AF.

Natural products for anti-fibrotic therapy in idiopathic pulmonary fibrosis: marine and terrestrial insights

Idiopathic Pulmonary Fibrosis (IPF) is a chronic fibrotic interstitial lung disease (ILD) of unknown etiology, characterized by increasing incidence and intricate pathogenesis. Current FDA-approved drugs suffer from significant side effects and limited efficacy, highlighting the urgent need for innovative therapeutic agents for IPF. Natural products (NPs), with their multi-target and multifaceted properties, present promising candidates for new drug development. This review delineates the anti-fibrotic pathways and targets of various natural products based on the established pathological mechanisms of IPF. It encompasses over 20 compounds, including flavonoids, saponins, polyphenols, terpenoids, natural polysaccharides, cyclic peptides, deep-sea fungal alkaloids, and algal proteins, sourced from both terrestrial and marine environments. The review explores their potential roles in mitigating pulmonary fibrosis, such as inhibiting inflammatory responses, protecting against lipid peroxidation damage, suppressing mesenchymal cell activation and proliferation, inhibiting fibroblast migration, influencing the synthesis and secretion of pro-fibrotic factors, and regulating extracellular matrix (ECM) synthesis and degradation. Additionally, it covers various in vivo and in vitro disease models, methodologies for analyzing marker expression and signaling pathways, and identifies potential new therapeutic targets informed by the latest research on IPF pathogenesis, as well as challenges in bioavailability and clinical translation. This review aims to provide essential theoretical and technical insights for the advancement of novel anti-pulmonary fibrosis drugs.

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.

From Epithelium to Therapy: Transitional Cells in Lung Fibrosis

Patients with idiopathic pulmonary fibrosis and lung fibrosis secondary to infections such as influenza A and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have limited treatment options outside of supportive therapy and lung transplantation. Multiple lung stem cell populations have been implicated in the pathogenesis of lung fibrosis, and more progenitor cell populations continue to be discovered and characterized. In this review, we summarize the functions and differentiation pathways of various cells that constitute the lung epithelium. We then focus on two subpopulations of KRT5+ or KRT8+ transitional cells that both originate from alveolar type II cells but experience different cell fates and play important roles in lung regeneration and repair. We address these transitional cells' potential role in fibrosis and bronchiolization of the alveoli, as they are correlated to aggregate near fibrotic foci in both in vivo models and in human fibrotic lung disease. We conclude by discussing recent advances in cell and organoid therapy to replace aberrant transitional cells and treat lung fibrosis. Namely, we focus on strategies to minimize immune clearance of transplanted cells and to optimize engraftment by transplanting cells precultured as three-dimensional organoids.

Effective-compounds of Jinshui Huanxian Formula acts as an SRC inhibitor to inhibit HK2-mediated H3K18 lactation and improve pulmonary fibrosis

BACKGROUND

The Active Ingredient Composition of Jinshui Huanxian Formula (ECC-JHF) consists of five active ingredients: icariin, isoliquiritigenin, nobiletin, peimine, and paeoniflorin, which demonstrate notable therapeutic effects on pulmonary fibrosis.

PURPOSE

Inhibition of glycolysis has been demonstrated to be effective in treating experimental idiopathic pulmonary fibrosis (IPF). This research seeks to explore the impact of aerobic glycolysis on the mitigation of pulmonary fibrosis through ECC-JHF.

METHODS

A pulmonary fibrosis mouse model was generated through the administration of bleomycin (Bleomycin). The degree of pulmonary fibrosis was analyzed through hematoxylin and eosin (H&E) staining as well as Masson's trichrome staining. Western Blot (WB), Immunofluorescence (IF), and real-time quantitative PCR (Q-PCR) assay for fibroblast activation markers and glycolysis-related genes in lung tissues. The Lactic Acid (LA) Content Assay Kit was employed to quantify lactate concentrations in lung tissues and fibroblast cultures. Immunoprecipitation (IP) was applied to detect lactylated modified protein levels, and mass spectrometry (MS) was used to analyze lactate substrate profiles in fibroblasts. WB was employed to detect the lactate modification level of histone H3K18 (H3K18la). The targets of ECC-JHF were analyzed using network pharmacology, while molecular docking and cellular enthusiasm transfer analysis (CETSA) examined the binding of ECC-JHF to SRC. The influence of ECC-JHF on SRC activation was assessed using WB. SRC small interfering RNA (siSRC) was designed and transfected into L929 cells to validate the function of SRC in the inhibition of fibroblast activation by ECC-JHF.

RESULTS

In BLM-induced pulmonary fibrosis mice, ECC-JHF significantly reduced alveolar inflammation and collagen deposition. In lung tissues and fibroblasts, ECC-JHF notably inhibited the expression of HK2, lactate levels, and lactylated modifying proteins. IP-MS and WB analyses showed that ECC-JHF significantly reduced H3K18la levels. Network pharmacology analysis, molecular docking and CETSA results indicated that SRC serves as a key target for ECC-JHF. siSRC effectively mitigated the impact of ECC-JHF on the expression of HK2, levels of H3K18la, and the activation of fibroblasts.

CONCLUSION

ECC-JHF may improve pulmonary fibrosis by inhibiting SRC activation, blocking HK2-mediated lactate production, down-regulating H3K18la levels, and inhibiting fibroblast activation. Our results serve as a significant reference for the advancement of ECC-JHF and the exploration of IPF.

Calcaratarin D, A Labdane Diterpenoid, Attenuates Bleomycin-Induced Pulmonary Fibrosis by Blocking Wnt/β-Catenin Signaling Pathway

Idiopathic pulmonary fibrosis (IPF) is one of the most common interstitial lung diseases with a high mortality rate. Calcaratarin D (CalD), a labdane diterpenoid, has been shown to possess anti-inflammatory properties. The present study evaluated the therapeutic potential of CalD in pulmonary fibrosis. A single dose of bleomycin (BLM, 2.5mg/kg) was instilled intratracheally in mice for up to 21 days to develop lung fibrosis. Oral CalD (50mg/kg) reduced BLM-induced inflammatory cell infiltration, especially pro-fibrotic Arg1-expressing interstitial macrophages in the bronchoalveolar lavage fluid. During the late fibrotic phase, CalD decreased BLM-induced mortality and body weight loss. In addition, CalD ameliorated lung histopathology, reduced collagen deposition and mucus hypersecretion, and improved lung functions in BLM-exposed mice. Furthermore, CalD modulated the levels of pro-inflammatory cytokines, chemokines, and growth factors in BAL fluid and lung tissues. In mouse lungs, BLM selectively upregulated Wnt10A level and promoted β-catenin nuclear translocation. CalD not only blocked Wnt10A/β-catenin signaling pathway but also reduced pro-fibrotic markers such as collagens, α-SMA and FHL2. In normal human lung fibroblasts, CalD inhibited TGF-β1-stimulated pro-fibrotic markers and Wnt/β-catenin signaling pathway by reducing Wnt10A production, upregulating endogenous Wnt antagonist DKK1 level, dephosphorylating Wnt ligand co-receptor LRP6, and preventing β-catenin and YAP/TAZ nuclear translocation. The antifibrotic action of CalD was shown to be dependent on its α,β-unsaturated γ-butyrolactone structure that is essential for CalD to form covalent interaction with cellular protein targets. Our results imply that CalD could be a novel antifibrotic agent for IPF, acting through blockade of the Wnt/β-catenin signaling pathway.

Fibrosis in PCLS: comparing TGF-β and fibrotic cocktail

INTRODUCTION

Fibrotic cocktail (FC) is a combination of pro-fibrotic and pro-inflammatory mediators that induces early fibrotic changes in organotypic lung models. We hypothesised that transforming growth factor beta 1 (TGF-β1) alone induces a pro-fibrotic effect similar to FC. Our aim was to compare the pro-fibrotic effects of TGF-β1 with FC in human precision-cut lung slices (PCLS).

METHODS

PCLS from "healthy" lung tissue of cancer patients undergoing surgery (n = 7) were incubated with TGF-β1, FC or control for 72 h. Gene expression markers for myofibroblasts differentiation, extracellular matrix (ECM), as well as TGF-β receptors were assessed (RT-qPCR). ECM proteins expression in lysates and supernatant was assessed by ELISA and immunofluorescence.

RESULTS

We found that TGF-β1 significantly increased gene expression of ACTA2, COL1A1, CCN2, and VIM compared to control but also compared to FC. FC showed a significant increase of matrix metalloproteinase (MMP) 7 and 1 compared to control, while TGF-β receptor 2 was lower after FC compared to TGF-β1 or control. FC or TGF-β1 showed similar fibronectin protein expression in lysates and supernatants, while type I collagen protein expression in lysates was significantly greater with TGF-β1 compared to control.

CONCLUSIONS

Our findings show that TGF-β1 induces consistent pro-fibrotic changes in PCLS after 72 h. Compared to TGF-β1, FC treatment resulted in reduced gene expression of TGF-β receptor 2 and increased MMPs expression, potentially mitigating the early pro-fibrotic effects. Selecting specific pro-fibrotic stimuli may be preferable depending on the research question and time point of interest in lung fibrosis studies using PCLS.

Saracatinib, a Src kinase inhibitor, enhances the renoprotective effect of metformin and losartan in diabetic nephropathy

OBJECTIVE

This research assesses renoprotective effects of saracatinib (Src) in diabetic nephropathy (DN) and the potential underlying processes.

MATERIALS AND METHODS

Rats were divided into: control, DN, DN + Met + Los, DN + Met + Src, and DN + Met + Los + Src. Rats' ABP, urinary albumin, urinary nephrin, and creatinine clearance were assessed. Blood samples were collected for measuring glycaemic state parameters, renal functions, oxidative stress markers, inflammatory mediators, aldosterone, and lipid profile. Kidneys were extracted for KIM-1 and nephrin gene expression, H&E, Masson's trichrome staining, and immunohistochemical assessment.

RESULTS

Significant increases in ABP, urinary albumin and nephrin, glycaemic measurements, urea, creatinine, aldosterone, inflammatory cytokines, MDA, lipids, renal fibrosis, H scores of VEGF and TGF-β, and renal KIM-1 expression were related to DN. However, there was a significant decrease in creatinine clearance, GSH, and nephrin expression in DN group compared with control group.

DISCUSSION AND CONCLUSION

The combination of metformin (Met), losartan (Los), and Src repaired DN alterations. Adding Src to Met and Los is superior to using them alone.

Pharmacological targeting of ECM homeostasis, fibroblast activation and invasion for the treatment of pulmonary fibrosis

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease with a dismal prognosis. While the standard-of-care (SOC) drugs approved for IPF represent a significant advancement in antifibrotic therapies, they primarily slow disease progression and have limited overall efficacy and many side effects. Consequently, IPF remains a condition with high unmet medical and pharmacological needs.

AREAS COVERED

A wide variety of molecules and mechanisms have been implicated in the pathogenesis of IPF, many of which have been targeted in clinical trials. In this review, we discuss the latest therapeutic targets that affect extracellular matrix (ECM) homeostasis and the activation of lung fibroblasts, with a specific focus on ECM invasion.

EXPERT OPINION

A promising new approach involves targeting ECM invasion by fibroblasts, a process that parallels cancer cell behavior. Several cancer drugs are now being tested in IPF for their ability to inhibit ECM invasion, offering significant potential for future treatments. The delivery of these therapies by inhalation is a promising development, as it may enhance local effectiveness and minimize systemic side effects, thereby improving patient safety and treatment efficacy.

Inhibition of Src signaling induces autophagic killing of Toxoplasma gondii via PTEN-mediated deactivation of Akt

The intracellular protozoan Toxoplasma gondii manipulates host cell signaling to avoid targeting by autophagosomes and lysosomal degradation. Epidermal Growth Factor Receptor (EGFR) is a mediator of this survival strategy. However, EGFR expression is limited in the brain and retina, organs affected in toxoplasmosis. This raises the possibility that T. gondii activates a signaling mechanism independently of EGFR to avoid autophagic targeting. We report T. gondii activates Src to promote parasite survival even in cells that lack EGFR. Blockade of Src triggered LC3 and LAMP-1 recruitment around the parasitophorous vacuole (PV) and parasite killing dependent on the autophagy protein, ULK1, and lysosomal enzymes. Src promoted PI3K activation and recruitment of activated Akt to the PV membrane. T. gondii promoted Src association with PTEN, and PTEN phosphorylation at Y240, S380, T382, and T383, hallmarks of an inactive PTEN conformation known to maintain Akt activation. Blockade of parasite killing was dependent of activated Akt. Src knockdown or treatment with the Src family kinase inhibitor, Saracatinib, impaired these events, leading to PTEN accumulation around the PV and a reduction in activated Akt recruitment at this site. Saracatinib treatment in mice with pre-established cerebral and ocular toxoplasmosis promoted PTEN recruitment around tachyzoites in neural tissue impairing recruitment of activated Akt, profoundly reducing parasite load and neural histopathology that were dependent of the autophagy protein, Beclin 1. Our studies uncovered an EGFR-independent pathway activated by T. gondii that enables its survival and is central to the development of neural toxoplasmosis.

Prevention of radiotherapy-induced pro-tumorigenic microenvironment by SFK inhibitors

Background: Radiotherapy is a widely employed technique for eradication of tumor using high-energy beams, and has been applied to approximately 50% of all solid tumor patients. However, its non-specific, cell-killing property leads to inevitable damage to surrounding normal tissues. Recent findings suggest that radiotherapy-induced tissue damage contributes to the formation of a pro-tumorigenic microenvironment. Methods: Here, we utilized two mouse strains and two organ-targeted radiotherapy models to uncover the mechanisms underlying the development of the radiotherapy-induced microenvironment. Results: Radiotherapy-induced tissue damage stimulates infiltration of monocyte-derived macrophages and their differentiation into M2 macrophages, ultimately leading to fibrosis and the formation of a pro-tumorigenic microenvironment. Notably, SRC family kinases (SFKs) emerged as crucial factors in the formation of the radiotherapy-induced pro-tumorigenic microenvironment. SFKs activation in epithelial cells and fibroblasts was triggered by direct exposure to irradiation or M2 macrophage cytokines. Remarkably, the administration of SFK-targeted inhibitors reversed myofibroblast activation, effectively ameliorating fibrosis and the pro-tumorigenic microenvironment in radiated tissues. Further, combined administration of radiotherapy and SFK-targeted inhibitors significantly enhanced the survival of tumor-bearing mice. Conclusions: Reshaping the tissue microenvironment by targeting SFKs is a potential strategy for preventing metastasis and recurrence following radiotherapy. The finding that clinically imperceptible damage can trigger a pro-tumorigenic microenvironment suggests the need for combining SFK-targeted inhibitors with radiotherapy.

Molecular imaging in experimental pulmonary fibrosis reveals that nintedanib unexpectedly modulates CCR2 immune cell infiltration

BACKGROUND

Pulmonary fibrosis is a challenging clinical problem with lung pathology featuring immune cell infiltrates, fibroblast expansion, and matrix deposition. Molecular analysis of diseased lungs and preclinical models have uncovered C-C chemokine receptor type 2 (CCR2)+ monocyte egress from the bone marrow into the lung, where they acquire profibrotic activities. Current drug treatment is focused on fibroblast activity. Alternatively, therapeutic targeting and monitoring CCR2+ cells may be an effective patient management strategy.

METHODS

Inhibition of CCR2+ cells and, as a benchmark, the clinical antifibrotic agent, nintedanib, were used in mouse lung fibrosis models. Lungs were evaluated directly for CCR2+ cell infiltration and by non-invasive CCR2+ positron emission tomography imaging (CCR2-PET).

FINDINGS

Lung CCR2+ cells were significantly elevated in the bleomycin model as determined by tissue evaluation and CCR2-PET imaging. A protective treatment protocol with an oral CCR2 inhibitor was compared to oral nintedanib. While we expected disparate effects on CCR2+ cells, each drug similarly decreased lung CCR2+ cells and fibrosis. Chemotaxis assays showed nintedanib indirectly inhibited C-C motif chemokine 2 (CCL2)-mediated migration of CCR2+ cells. Even delayed therapeutic administration of nintedanib in bleomycin and the silicosis progressive fibrosis models decreased the accumulation of CCR2+ lung cells. In these treatments early CCR2-PET imaging predicted the later development of fibrosis.

INTERPRETATION

The inhibition of CCR2+ cell egress is likely a critical controller for stabilising lung fibrosis, as provided by nintedanib. Imaging with CCR2-PET may be useful to monitor nintedanib treatment responses, guide decision-making in the treatment of patients with progressive pulmonary fibrosis, and as a biomarker for drug development.

FUNDING

National Institutes of Health (NIH), R01HL131908 (SLB), R35HL145212 (YL), P41EB025815 (YL), K01DK133670 (DHK); Barnes Jewish Hospital Foundation (SLB).

Precision Cut Lung Slices: Emerging Tools for Preclinical and Translational Lung Research. An Official American Thoracic Society Workshop Report

The urgent need for effective treatments for acute and chronic lung diseases underscores the significance of developing innovative preclinical human research tools. The 2023 ATS Workshop on Precision Cut Lung Slices (PCLS) brought together 35 experts to discuss and address the role of human tissue-derived PCLS as a unique tool for target and drug discovery and validation in pulmonary medicine. With increasing interest and usage, along with advancements in methods and technology, there is a growing need for consensus on PCLS methodology and readouts. The current document recommends standard reporting criteria and emphasizes the requirement for careful collection and integration of clinical metadata. We further discuss current clinically relevant readouts that can be applied to PCLS and highlight recent developments and future steps for implementing novel technologies for PCLS modeling and analysis. The collection and correlation of clinical metadata and multiomic analysis will further advent the integration of this preclinical platform into patient endotyping and the development of tailored therapies for lung disease patients.

Construction of a prognostic model for colon cancer by combining endoplasmic reticulum stress responsive genes

Endoplasmic reticulum stress may affect the occurrence and development of cancer. However, its effect on the prognosis of colon cancer (CC) patients is not clear yet. Herein, based on TCGA database, we screened 15 endoplasmic reticulum stress responsive genes (ERSRGs) associated with the prognosis of CC patients by Cox regression. By LASSO and multivariate Cox regression analyses, a prognostic risk assessment model involving 12 genes (DNAJB2, EIF4A1, YPEL4, COQ10A, IRX3, ASPHD1, NTRK2, TRIM39, XBP1, GRIN2B, LRRC59, and RORC) was built. The survival curves indicated that patients in the low-risk group had good prognosis. ROC curves demonstrated a good performance of this 12-gene prognostic model, and the Riskscore could be considered as an independent prognostic factor. Patients in low-risk group benefit more from immune checkpoint inhibitor and immune checkpoint blockade (ICB) treatment. Besides, the enrichment analysis suggested a remarkable difference in Ca2+ signaling in both groups. Finally, based on the cMAP database, we identified several potential drugs that could target high-risk groups, such as Dasatinib, GNF-2, Saracatinib, and WZ-1-84. To sum up, our research constructed an ERSRGs-characteristic prognostic model. The model is a promising biomarker for prediction of clinical outcomes and immune therapy response of CC patients. SIGNIFICANCE: Based on the transcriptomic data of colon cancer in the TCGA database, this study screens 12 endoplasmic reticulum stress-related genes (ERSRGs), including DNAJB2, EIF4A1, YPEL4, COQ10A, IRX3, ASPHD1, NTRK2, TRIM39, XBP1, asphD1, NTRK2. GRIN2B, LRRC59, and RORC, and a prognostic model was constructed. This model can be used as a predictor of prognosis and immunotherapy response in colon cancer patients. At the same time, model-based prediction of drugs can also be a potential option for colon cancer treatment in the future.

What Is on the Horizon for Treatments in Idiopathic Pulmonary Fibrosis?

Idiopathic pulmonary fibrosis (IPF) is a progressive and often fatal lung disease most commonly encountered in older individuals. Several decades of research have contributed to a better understanding of its pathogenesis, though only two drugs thus far have shown treatment efficacy, i.e., by slowing the decline of lung function. The pathogenesis of IPF remains incompletely understood and involves multiple complex interactions and mechanisms working in tandem or separately to result in unchecked deposition of extracellular matrix components and collagen characteristic of the disease. These mechanisms include aberrant response to injury in the alveolar epithelium, inappropriate communication between epithelial cells and mesenchymal cells, imbalances between oxidative injury and tissue repair, recruitment of inflammatory pathways that induce fibrosis, and cell senescence leading to sustained activation and proliferation of fibroblasts and myofibroblasts. Targeted approaches to each of these mechanistic pathways have led to recent clinical studies evaluating the safety and efficacy of several agents. This review highlights selected concepts in the pathogenesis of IPF as a rationale for understanding current or future therapeutic approaches, followed by a review of several selected agents and their recent or active clinical studies. Current novel therapies include approaches to attenuating or modifying specific cellular or signaling processes in the fibrotic pathway, modifying inflammatory and metabolic derangements, and minimizing inappropriate cell senescence.

Albendazole ameliorates aerobic glycolysis in myofibroblasts to reverse pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic and lethal lung disorder for which effective treatments remain limited. Recent investigations revealed a potential link between altered glucose metabolism and the activation of fibroblasts, the key cells responsible for generating and depositing extracellular matrix proteins within the lung interstitium during IPF development.

METHOD

In this study, we aimed to investigate the potential therapeutic impact of albendazole on fibroblast to myofibroblast transition in IPF. We assess albendazole's effectiveness in attenuating the activation of fibroblasts. We focused on elucidating the mechanism underlying albendazole's impact on TGF-β1-induced aerobic glycolysis in both lung tissues and fibroblasts obtained from patients with IPF and other lung fibrosis types. Furthermore, the antifibrotic effects of oral administration of albendazole were investigated in mouse models of pulmonary fibrosis induced by BLM or SiO2. Human precision-cut lung slices were employed to evaluate the impact of albendazole following TGF-β1 stimulation.

RESULT

In this work, we demonstrated that albendazole, a first-line broad-spectrum anthelmintic drug, effectively attenuated fibroblast to myofibroblast transition through alleviating TGF-β1-induced aerobic glycolysis dependent on the LRRN3/PFKFB3 signaling pathway. Additionally, LRRN3 expression was downregulated in both lung tissues and fibroblasts from patients with IPF and other types of lung fibrosis. Importantly, the levels of LRRN3 correlated with the progression of the disease. Notably, oral administration of albendazole exerted potent antifibrotic effects in mouse models of pulmonary fibrosis induced by BLM or SiO2, and in human precision-cut lung slices after TGF-β1 stimulation, as evidenced by improvements in lung morphology, reduced myofibroblast formation, and downregulation of α-SMA, collagen type 1 and Fibronectin expression in the lungs.

CONCLUSION

Our study implies that albendazole can act as a potent agonist of LRRN3 during fibroblast to myofibroblast differentiation and its oral administration shows potential as a viable therapeutic approach for managing IPF.

Flavonoids for treating pulmonary fibrosis: Present status and future prospects

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with an unknown underlying cause. There is no complete cure for IPF; however, two anti-fibrotic agents (Nintedanib and pirfenidone) are approved by the USFDA to extend the patient's life span. Therefore, alternative therapies supporting the survival of fibrotic patients have been studied in recent literature. The abundance of phenolic compounds, particularly flavonoids, has gathered attention due to their potential health benefits. Various flavonoids, like naringin, quercetin, baicalin, baicalein, puerarin, silymarin, and kaempferol, exhibit anti-inflammatory and anti-oxidant properties, which help decrease lung fibrosis. Various databases, including PubMed, EBSCO, ProQuest, and Scopus, as well as particular websites, such as the World Health Organisation and the National Institutes of Health, were used to conduct a literature search. Several mechanisms of action of flavonoids are reported with the help of in vivo and cell line studies emphasizing their ability to modulate oxidative stress, inflammation, and fibrotic processes in the lungs. They are reported for the restoration of biomarkers like hydroxyproline, cytokines, superoxide dismutase, malondialdehyde and others associated with IPF and for modulating various pathways responsible for the progression of pulmonary fibrosis. Yet, flavonoids have some drawbacks, such as poor solubility, challenging drug loading, stability issues, and scarce bioavailability. Therefore, novel formulations of flavonoids are explored, including liposomes, solid lipid microparticles, polymeric nanoparticles, nanogels, and nanocrystals, to enhance the therapeutic efficacy of flavonoids in pulmonary fibrosis. This review focuses on the role of flavonoids in mitigating idiopathic pulmonary fibrosis, their mode of action and novel formulations.

Toll-like Receptor 9 Inhibition Mitigates Fibroproliferative Responses in Translational Models of Pulmonary Fibrosis

RATIONALE

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease for which current treatment options only slow clinical progression. Previously, we identified a subset of patients with IPF with an accelerated disease course associated with fibroblast expression of Toll-Like Receptor 9 (TLR9) mediated by interactions with its ligand mitochondrial DNA (mtDNA).

OBJECTIVES

We aimed to show that TLR9 activation induces fibroproliferative responses that are abrogated by its antagonism by using two commercially-available indirect inhibitors and a proprietary, selective direct small molecule inhibitor.

METHODS

We employed two independent cohorts of patients with IPF, multiple in vitro fibroblast cell culture platforms, an in vivo mouse model, and an ex vivo human precision cut lung slices system to investigate the clinical and biologic significance of TLR9 in this disease.

MEASUREMENTS AND MAIN RESULTS

In two independent IPF cohorts, plasma mtDNA activates TLR9 in a manner associated with the expression of MCP-1, IL-6, TNFα, and IP-10 and worsened transplant-free survival. Our cell culture platform showed that TLR9 mediates fibroblast activation via TGFβ1 and stiff substrates, and that its antagonism, particularly direct inhibition, ameliorates this process, including production of these TLR9 associated pharmacodynamic endpoints. We further demonstrated that direct TLR9 inhibition mitigates these fibroproliferative responses in our in vivo and ex vivo models of pulmonary fibrosis.

CONCLUSIONS

In this novel study, we found that direct TLR9 inhibition mitigates fibroproliferative responses in preclinical models of pulmonary fibrosis. Our work demonstrates the therapeutic potential of direct TLR9 antagonism in IPF and related fibrotic lung diseases.

Characteristics of human donor lungs utilized for research

Introduction

Many fundamental discoveries have occurred using primary cells from deceased donor lungs. These cells respond differently to injury when there are underlying co-morbidities like diabetes mellitus, hypertension, aging and exposures to cigarette smoke, cocaine and chronic alcohol use. However, the prevalence of these characteristics in donor lungs utilized for research is currently unknown.

Methods

This retrospective cohort study procured data of lung transplant donors from Mid-America Transplant from January 2017 until July 2023. The donors were characterized based on lung utilization into three groups - lungs used for research, lungs used for transplant, and lungs not recovered from donors for either research or transplantation.

Results

The mean age of donors whose lungs were utilized for research was 41±18 years. 25% of them were expanded criteria donors (ECD) while 10% of the donors in the transplant cohort were ECD. 14% of the donors whose lungs were utilized for research had history of diabetes compared to 8% of donors whose lungs were transplanted. A quarter of the research donor population had positive history of cigarette use within the preceding 20 years. At least 40% of donors had a positive history of non-intravenous drug use, of whom a majority had a history of continued non-intravenous drug use.

Conclusions

No strict selection criteria or protocols exist when human donor lungs are obtained for ex-vivo research. There is a high prevalence of diabetes mellitus, history of smoking and non-intravenous drug use along with older age distribution in donors whose lungs used are for research.

Highlights on Future Treatments of IPF: Clues and Pitfalls

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease characterized by irreversible scarring of lung tissue, leading to death. Despite recent advancements in understanding its pathophysiology, IPF remains elusive, and therapeutic options are limited and non-curative. This review aims to synthesize the latest research developments, focusing on the molecular mechanisms driving the disease and on the related emerging treatments. Unfortunately, several phase 2 studies showing promising preliminary results did not meet the primary endpoints in the subsequent phase 3, underlying the complexity of the disease and the need for new integrated endpoints. IPF remains a challenging condition with a complex interplay of genetic, epigenetic, and pathophysiological factors. Ongoing research into the molecular keystones of IPF is critical for the development of targeted therapies that could potentially stop the progression of the disease. Future directions include personalized medicine approaches, artificial intelligence integration, growth in genetic insights, and novel drug targets.

Sinomenine ameliorates bleomycin-induced pulmonary fibrosis by inhibiting the differentiation of fibroblast into myofibroblast

Idiopathic pulmonary fibrosis (IPF) represents a severe interstitial lung disease characterized by limited therapeutic interventions. Recent study has suggested that sinomenine (SIN), an alkaloid derived from the roots of Sinomenium acutum, demonstrates efficacy in interrupting aerobic glycolysis, a predominant metabolic pathway in myofibroblasts. However, its pharmacological potential in the context of pulmonary fibrosis remains inadequately explored. In the present study, we established a bleomycin (BLM)-induced pulmonary fibrosis mouse model and subjected the mice to a one-week regimen of SIN treatment to assess its efficacy. Additionally, a TGF-β1-induced primary lung fibroblast model was employed to investigate the molecular mechanism underlying the effects of SIN. Our observations revealed robust anti-pulmonary fibrosis properties associated with SIN treatment, as evidenced by reduced extracellular matrix deposition, diminished hydroxyproline contents, improved Ashcroft scores, and enhanced lung function parameters. Furthermore, SIN administration significantly impeded TGF-β1-induced fibroblast-to-myofibroblast differentiation. Mechanistically, SIN exerted its beneficial effects by mitigating aerobic glycolysis, achieved through the inhibition of the expression of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (Pfkfb3). Notably, the protective effects of SIN on fibroblasts were reversed upon ectopic overexpression of Pfkfb3. In conclusion, our data underscore the potential of SIN to attenuate fibroblast-to-myofibroblast differentiation by modulating Pfkfb3-associated aerobic glycolysis and SIN emerges as a promising anti-fibrotic agent for pulmonary fibrosis in clinical practice.

Precision cut lung slices: an integrated ex vivo model for studying lung physiology, pharmacology, disease pathogenesis and drug discovery

Precision Cut Lung Slices (PCLS) have emerged as a sophisticated and physiologically relevant ex vivo model for studying the intricacies of lung diseases, including fibrosis, injury, repair, and host defense mechanisms. This innovative methodology presents a unique opportunity to bridge the gap between traditional in vitro cell cultures and in vivo animal models, offering researchers a more accurate representation of the intricate microenvironment of the lung. PCLS require the precise sectioning of lung tissue to maintain its structural and functional integrity. These thin slices serve as invaluable tools for various research endeavors, particularly in the realm of airway diseases. By providing a controlled microenvironment, precision-cut lung slices empower researchers to dissect and comprehend the multifaceted interactions and responses within lung tissue, thereby advancing our understanding of pulmonary pathophysiology.

Inhibition of TGF-β1/Smad3 signaling by compound 5aa: A potential treatment for idiopathic pulmonary fibrosis

The incidence of idiopathic pulmonary fibrosis (IPF) has been steadily increasing each year, posing significant challenges in its treatment. In this study, we conducted the design and synthesis of 23 new inhibitors that specifically target the TGF-β1/Smad3 pathway. Initially, we employed a cell model of TGF-β-induced pulmonary fibrosis, using cell survival rate and HYP expression as indicators to identify the potent ingredient 5aa, which demonstrated significant anti-pulmonary fibrosis activity. Subsequently, we induced mice with bleomycin (BLM) to establish an experimental animal model of pulmonary fibrosis, and evaluated the pharmacodynamics of 5aa in vivo against pulmonary fibrosis. The alterations in HYP and collagen levels in BLM-induced pulmonary fibrosis mice were analyzed using ELISA and immunohistochemistry techniques. The results indicated that compound 5aa effectively suppressed the fibrotic response induced by TGF-β1, inhibited the expression of the fibrotic marker α-SMA, and hindered the EMT process in NIH3T3 cells. Additionally, oral administration of 5aa demonstrated significant therapeutic effects in a mouse model of IPF, comparable to the established drug Nintedanib. Moreover, compound 5aa exhibited higher bioavailability in vivo compared to Nintedanib. These collective outcomes suggest that 5aa holds promise as a potential inhibitor of TGF-β1/Smad3 signaling for the treatment of IPF.

Low concentrations of saracatinib promote definitive endoderm differentiation through inhibition of FAK-YAP signaling axis

Optimizing the efficiency of definitive endoderm (DE) differentiation is necessary for the generation of diverse organ-like structures. In this study, we used the small molecule inhibitor saracatinib (SAR) to enhance DE differentiation of human embryonic stem cells and induced pluripotent stem cells. SAR significantly improved DE differentiation efficiency at low concentrations. The interaction between SAR and Focal Adhesion Kinase (FAK) was explored through RNA-seq and molecular docking simulations, which further supported the inhibition of DE differentiation by p-FAK overexpression in SAR-treated cells. In addition, we found that SAR inhibited the nuclear translocation of Yes-associated protein (YAP), a downstream effector of FAK, which promoted DE differentiation. Moreover, the addition of SAR enabled a significant reduction in activin A (AA) from 50 to 10 ng/mL without compromising DE differentiation efficiency. For induction of the pancreatic lineage, 10 ng/ml AA combined with SAR at the DE differentiation stage yielded a comparative number of PDX1+/NKX6.1+ pancreatic progenitor cells to those obtained by 50 ng/ml AA treatment. Our study highlights SAR as a potential modulator that facilitates the cost-effective generation of DE cells and provides insight into the orchestration of cell fate determination.

Deficiency of Nuclear Receptor Coactivator 3 Aggravates Diabetic Kidney Disease by Impairing Podocyte Autophagy

Nuclear receptors (NRs) are important transcriptional factors that mediate autophagy, preventing podocyte injury and the progression of diabetic kidney disease (DKD). However, the role of nuclear receptor coactivators that are powerful enhancers for the transcriptional activity of NRs in DKD remains unclear. In this study, a significant decrease in Nuclear Receptor Coactivator 3 (NCOA3) is observed in injured podocytes caused by high glucose treatment. Additionally, NCOA3 overexpression counteracts podocyte damage by improving autophagy. Further, Src family member, Fyn is identified to be the target of NCOA3 that mediates the podocyte autophagy process. Mechanistically, NCOA3 regulates the transcription of Fyn in a nuclear receptor, PPAR-γ dependent way. Podocyte-specific NCOA3 knockout aggravates albuminuria, glomerular sclerosis, podocyte injury, and autophagy in DKD mice. However, the Fyn inhibitor, AZD0530, rescues podocyte injury of NCOA3 knockout DKD mice. Renal NCOA3 overexpression with lentivirus can ameliorate podocyte damage and improve podocyte autophagy in DKD mice. Taken together, the findings highlight a novel target, NCOA3, that protects podocytes from high glucose injury by maintaining autophagy.

Kefir peptides mitigate bleomycin-induced pulmonary fibrosis in mice through modulating oxidative stress, inflammation and gut microbiota

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive and life-threatening lung disease with high mortality rates. The limited availability of effective drugs for IPF treatment, coupled with concerns regarding adverse effects and restricted responsiveness, underscores the need for alternative approaches. Kefir peptides (KPs) have demonstrated antioxidative, anti-inflammatory, and antifibrotic properties, along with the capability to modulate gut microbiota. This study aims to investigate the impact of KPs on bleomycin-induced pulmonary fibrosis.

METHODS

Mice were treated with KPs for four days, followed by intratracheal injection of bleomycin for 21 days. Comprehensive assessments included pulmonary functional tests, micro-computed tomography (µ-CT), in vivo image analysis using MMPsense750, evaluation of inflammation- and fibrosis-related gene expression in lung tissue, and histopathological examinations. Furthermore, a detailed investigation of the gut microbiota community was performed using full-length 16 S rRNA sequencing in control mice, bleomycin-induced fibrotic mice, and KPs-pretreated fibrotic mice.

RESULTS

In KPs-pretreated bleomycin-induced lung fibrotic mice, notable outcomes included the absence of significant bodyweight loss, enhanced pulmonary functions, restored lung tissue architecture, and diminished thickening of inter-alveolar septa, as elucidated by morphological and histopathological analyses. Concurrently, a reduction in the expression levels of oxidative biomarkers, inflammatory factors, and fibrotic indicators was observed. Moreover, 16 S rRNA sequencing demonstrated that KPs pretreatment induced alterations in the relative abundances of gut microbiota, notably affecting Barnesiella_intestinihominis, Kineothrix_alysoides, and Clostridium_viride.

CONCLUSIONS

Kefir peptides exerted preventive effects, protecting mice against bleomycin-induced lung oxidative stress, inflammation, and fibrosis. These effects are likely linked to modifications in the gut microbiota community. The findings highlight the therapeutic potential of KPs in mitigating pulmonary fibrosis and advocate for additional exploration in clinical settings.

Dual Drug Repurposing: The Example of Saracatinib

Saracatinib (AZD0530) is a dual Src/Abl inhibitor initially developed by AstraZeneca for cancer treatment; however, data from 2006 to 2024 reveal that this drug has been tested not only for cancer treatment, but also for the treatment of other diseases. Despite the promising pre-clinical results and the tolerability shown in phase I trials, where a maximum tolerated dose of 175 mg was defined, phase II clinical data demonstrated a low therapeutic action against several cancers and an elevated rate of adverse effects. Recently, pre-clinical research aimed at reducing the toxic effects and enhancing the therapeutic performance of saracatinib using nanoparticles and different pharmacological combinations has shown promising results. Concomitantly, saracatinib was repurposed to treat Alzheimer's disease, targeting Fyn. It showed great clinical results and required a lower daily dose than that defined for cancer treatment, 125 mg and 175 mg, respectively. In addition to Alzheimer's disease, this Src inhibitor has also been studied in relation to other health conditions such as pulmonary and liver fibrosis and even for analgesic and anti-allergic functions. Although saracatinib is still not approved by the Food and Drug Administration (FDA), the large number of alternative uses for saracatinib and the elevated number of pre-clinical and clinical trials performed suggest the huge potential of this drug for the treatment of different kinds of diseases.

Promising advances in treatments for the management of idiopathic pulmonary fibrosis

INTRODUCTION

Following the INPULSIS and ASCEND studies, leading to the first two approved antifibrotic therapies for patients with IPF, ongoing investigations are firmly exploring novel agents for a targeted effective and better tolerated therapy able to improve the natural history of the disease.

AREAS COVERED

This review aims to analyze recent advances in pharmacological research of IPF, discussing the currently available treatments and the novel drugs under investigation in phase 3 trials, with particular emphasis on BI 1015550 and inhaled treprostinil. The literature search utilized Medline and Clinicaltrials.org databases. Critical aspects of clinical trial design in IPF are discussed in light of recently completed phase III studies.

EXPERT OPINION

While randomized clinical trials in IPF are currently underway, future objectives should explore potential synergistic benefits when combining novel molecules with the existing therapies and identify more specific molecular targets. Moreover, refining the study design represent another crucial goal. The aim of the pharmacological research will be not only stabilizing but also potentially reversing the fibrotic changes in IPF.

Classification of molecular subtypes for colorectal cancer and development of a prognostic model based on necroptosis-related genes

Background

Necroptosis could regulate immunity in cancers, and stratification of colorectal cancer (CRC) subtypes based on key genes related to necroptosis might be a novel strategy for CRC treatment.

Method

The RNA-sequencing data of CRC and other 31 types of cancers were obtained from The Cancer Genome Atlas (TCGA) database. Consensus clustering was performed based on protein-coding genes (PCGs) related to necroptosis score calculated by single sample gene set enrichment analysis (ssGSEA). Module genes showing a significant positive correlation with the necroptosis score were identified by weighted correlation network analysis (WGCNA) and further used to develop a risk stratification model applying least absolute shrinkage and selection operator (LASSO) and Cox regression analysis. The risks score for each sample in CRC cohorts, immunotherapy cohorts and pan-cancer study cohorts was calculated.

Result

Two subgroups (C1 cluster and C2 cluster) of CRC were identified based on the necroptosis score. Compared with C1 cluster, the survival possibility of C2 cluster was greatly reduced, the levels of necroptosis score, immune cell infiltration, immune score and expression of immune checkpoint molecules were significantly increased and immunotherapy response was less active. Low-risk patients defined by the risk model had a significant survival advantage than high-risk counterparts in both CRC and the other 31 cancer types. Furthermore, the risk model was also more efficient than the Tumor Immune Dysfunction and Exclusion (TIDE) tool in predicting OS and immunotherapy response for the samples in the immunotherapy cohort.

Conclusion

CRC patients were classified by necroptosis score-related PCGs, and a risk model was designed to evaluate the immunotherapy and prognosis of patients with CRC. The current molecular subtype and prognostic model could help stratify patients with different risks and predict their prognosis and immunotherapy sensitivity.

ERS International Congress 2023: highlights from the Basic and Translational Sciences Assembly

Early career members of Assembly 3 (Basic and Translational Sciences) of the European Respiratory Society (ERS) summarise the key messages discussed during six selected sessions that took place at the ERS International Congress 2023 in Milan, Italy. Aligned with the theme of the congress, the first session covered is "Micro- and macro-environments and respiratory health", which is followed by a summary of the "Scientific year in review" session. Next, recent advances in experimental methodologies and new technologies are discussed from the "Tissue modelling and remodelling" session and a summary provided of the translational science session, "What did you always want to know about omics analyses for clinical practice?", which was organised as part of the ERS Translational Science initiative's aims. The "Lost in translation: new insights into cell-to-cell crosstalk in lung disease" session highlighted how next-generation sequencing can be integrated with laboratory methods, and a final summary of studies is presented from the "From the transcriptome landscape to innovative preclinical models in lung diseases" session, which links the transcriptome landscape with innovative preclinical models. The wide range of topics covered in the selected sessions and the high quality of the research discussed demonstrate the strength of the basic and translational science being presented at the international respiratory conference organised by the ERS.

Localized Administration of Bcar3 siRNA via Nano-Self-Assembly to Treat Idiopathic Pulmonary Fibrosis by Disrupting Macrophage-Fibroblast Crosstalk

Background

Idiopathic pulmonary fibrosis (IPF) is a severe interstitial lung disease characterized by chronic lung injury leading to macrophage infiltration and fibroblast activation. However, there is no effective therapeutic strategy targeting the crucial crosstalk between macrophages and fibroblasts to halt IPF progression.

Methods

Studies were conducted in IPF patients and fibrotic mice models to elucidate the role of Bcar3 in the pathogenesis of pulmonary fibrosis. The effect of Bcar3 on macrophage polarization, fibroblast activation, and related signaling pathways were next investigated to unravel the underlying mechanisms.

Results

Our study elucidates a marked increase in Bcar3 expression in lung tissues from IPF patients and fibrotic mice, recording 1.7 and 7.8-fold increases compared to control subjects, respectively. Additionally, Bcar3 was found to significantly enhance macrophage activation and fibroblast differentiation, observable in both in vivo and in vitro settings. Mechanistically, the upregulation of Bcar3 in macrophages was reliant on Stat6, while in fibroblasts, it depended on TGFβR1/Smad3. Furthermore, Bcar3 augmented IL-4/Stat6 pathway in macrophages and TGF-β/Smad3 pathway in fibroblasts, supporting a synergistic activation loop that expedited lung fibrogenesis. Notably, intratracheal injection of liposomes containing Bcar3 siRNA precisely delivered gene therapeutics to lung macrophages and fibroblasts, effectively reducing Bcar3 expression to 59% of baseline levels. Importantly, this intervention protected mice from lung fibrosis induced by either FITC or bleomycin, as well as human precision-cut lung slices against TGF-β1 stimulation.

Conclusion

Our study underscores the pivotal role of Bcar3 in orchestrating the macrophage-fibroblast crosstalk during pulmonary fibrosis progression. Targeting Bcar3 emerges as a novel therapeutic avenue to halt IPF progression and enhance patient prognosis.

Pulmonary Fibrosis Stakeholder Summit: A Joint NHLBI, Three Lakes Foundation, and Pulmonary Fibrosis Foundation Workshop Report

Despite progress in elucidation of disease mechanisms, identification of risk factors, biomarker discovery, and the approval of two medications to slow lung function decline in idiopathic pulmonary fibrosis and one medication to slow lung function decline in progressive pulmonary fibrosis, pulmonary fibrosis remains a disease with a high morbidity and mortality. In recognition of the need to catalyze ongoing advances and collaboration in the field of pulmonary fibrosis, the NHLBI, the Three Lakes Foundation, and the Pulmonary Fibrosis Foundation hosted the Pulmonary Fibrosis Stakeholder Summit on November 8-9, 2022. This workshop was held virtually and was organized into three topic areas: 1) novel models and research tools to better study pulmonary fibrosis and uncover new therapies, 2) early disease risk factors and methods to improve diagnosis, and 3) innovative approaches toward clinical trial design for pulmonary fibrosis. In this workshop report, we summarize the content of the presentations and discussions, enumerating research opportunities for advancing our understanding of the pathogenesis, treatment, and outcomes of pulmonary fibrosis.

Saracatinib inhibits necroptosis and ameliorates psoriatic inflammation by targeting MLKL

Necroptosis is a kind of programmed cell death that causes the release of damage-associated molecular patterns and inflammatory disease including skin inflammation. Activation of receptor-interacting serine/threonine kinase 1 (RIPK1), RIPK3, and mixed lineage kinase domain-like protein (MLKL) is the hallmark of tumour necrosis factor α (TNF)-induced necroptosis. Here, we screened a small-molecule compound library and found that saracatinib inhibited TNF-induced necroptosis. By targeting MLKL, Saracatinib interfered with the phosphorylation, translocation, and oligomerization of MLKL induced by TNF. Consistently, mutation of the saracatinib-binding site of MLKL reduced the inhibitory effect of saracatinib on TNF-induced necroptosis. In an imiquimod (IMQ)-induced psoriasis mouse model, saracatinib effectively blocked MLKL phosphorylation and inflammatory responses in vivo. Taken together, these findings indicate that saracatinib inhibits necroptosis by targeting MLKL, providing a potential therapeutic approach for skin inflammation-related diseases such as psoriasis.

TrxR/Trx inhibitor butaselen ameliorates pulmonary fibrosis by suppressing NF-κB/TGF-β1/Smads signaling

Pulmonary fibrosis is highly lethal with limited treatments. Butaselen (BS) is an inhibitor of thioredoxin reductase (TrxR)/thioredoxin (Trx) with anti-tumor activity. However, its impact on pulmonary fibrosis and the involved mechanisms remain unclear. Here, we demonstrate that BS is a potential drug for the treatment of pulmonary fibrosis. Specifically, BS can inhibit pulmonary fibrosis both in vitro and in vivo, with comparable efficacy and enhanced safety when compared with pirfenidone. BS and dexamethasone display a synergistic effect in inhibiting pulmonary fibrosis both in vitro and in vivo. Mechanistic studies reveal that BS can inhibit the TrxR activity during pulmonary fibrosis. RNA-sequencing analysis identifies that genes of ECM-related signaling pathways are notably affected by BS. BS can not only inhibit the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and reduce pulmonary fibrosis-related inflammation, but also reduce NF-κB-activated transcriptional expression of transforming growth factor-β1 (TGF-β1), which leads to the inactivation of Smad2/Smad3 and decrease of collagen formation and fibrosis. Moreover, the knockdown of Trx1 with siRNA can also inhibit NF-κB/TGF-β1/Smads signaling. In conclusion, the TrxR/Trx inhibitor butaselen can suppress pulmonary fibrosis by inhibiting NF-κB/TGF-β1/Smads signaling.

Perspectives on Post-COVID-19 Pulmonary Fibrosis Treatment

Pulmonary fibrosis, a critical outcome of chronic inflammatory diseases, has gained prominence in the context of post-coronavirus (post-COVID-19) complications. This review delves into the multifaceted landscape of post-COVID-19 pulmonary fibrosis, elucidating the intricate molecular mechanisms underlying its pathogenesis and highlighting promising therapeutic avenues. Examining the aftermath of severe acute respiratory syndrome-2 (SARS-CoV-2) infection, the review reveals key signaling pathways implicated in the fibrotic cascade. Drawing parallels with previous coronavirus outbreaks enhances our understanding of the distinctive features of post-COVID-19 fibrosis. Antifibrotic drugs, like pirfenidone and nintedanib, take center stage; their mechanisms of action and potential applications in post-COVID-19 cases are thoroughly explored. Beyond the established treatments, this review investigates emerging therapeutic modalities, including anti-interleukin agents, immunosuppressants, and experimental compounds, like buloxybutide, saracatinib, sirolimus, and resveratrol. Emphasizing the critical importance of early intervention, this review highlights the dynamic nature of post-COVID-19 pulmonary fibrosis research. In conclusion, the synthesis of current knowledge offers a foundation for advancing our approaches to the prevention and treatment of these consequential sequelae of COVID-19.

Unagi: Deep Generative Model for Deciphering Cellular Dynamics and In-Silico Drug Discovery in Complex Diseases

Human diseases are characterized by intricate cellular dynamics. Single-cell sequencing provides critical insights, yet a persistent gap remains in computational tools for detailed disease progression analysis and targeted in-silico drug interventions. Here, we introduce UNAGI, a deep generative neural network tailored to analyze time-series single-cell transcriptomic data. This tool captures the complex cellular dynamics underlying disease progression, enhancing drug perturbation modeling and discovery. When applied to a dataset from patients with Idiopathic Pulmonary Fibrosis (IPF), UNAGI learns disease-informed cell embeddings that sharpen our understanding of disease progression, leading to the identification of potential therapeutic drug candidates. Validation via proteomics reveals the accuracy of UNAGI's cellular dynamics analyses, and the use of the Fibrotic Cocktail treated human Precision-cut Lung Slices confirms UNAGI's predictions that Nifedipine, an antihypertensive drug, may have antifibrotic effects on human tissues. UNAGI's versatility extends to other diseases, including a COVID dataset, demonstrating adaptability and confirming its broader applicability in decoding complex cellular dynamics beyond IPF, amplifying its utility in the quest for therapeutic solutions across diverse pathological landscapes.

Pulmonary fibrosis: Emerging diagnostic and therapeutic strategies

Fibrosis is the concluding pathological outcome and major cause of morbidity and mortality in a number of common chronic inflammatory, immune-mediated and metabolic diseases. The progressive deposition of a collagen-rich extracellular matrix (ECM) represents the cornerstone of the fibrotic response and culminates in organ failure and premature death. Idiopathic pulmonary fibrosis (IPF) represents the most rapidly progressive and lethal of all fibrotic diseases with a dismal median survival of 3.5 years from diagnosis. Although the approval of the antifibrotic agents, pirfenidone and nintedanib, for the treatment of IPF signalled a watershed moment for the development of anti-fibrotic therapeutics, these agents slow but do not halt disease progression or improve quality of life. There therefore remains a pressing need for the development of effective therapeutic strategies. In this article, we review emerging therapeutic strategies for IPF as well as the pre-clinical and translational approaches that will underpin a greater understanding of the key pathomechanisms involved in order to transform the way we diagnose and treat pulmonary fibrosis.

Emerging opportunities to treat idiopathic pulmonary fibrosis: Design, discovery, and optimizations of small-molecule drugs targeting fibrogenic pathways

Idiopathic pulmonary fibrosis (IPF) is the most common fibrotic form of idiopathic diffuse lung disease. Due to limited treatment options, IPF patients suffer from poor survival. About ten years ago, Pirfenidone (Shionogi, 2008; InterMune, 2011) and Nintedanib (Boehringer Ingelheim, 2014) were approved, greatly changing the direction of IPF drug design. However, limited efficacy and side effects indicate that neither can reverse the process of IPF. With insights into the occurrence of IPF, novel targets and agents have been proposed, which have fundamentally changed the treatment of IPF. With the next-generation agents, targeting pro-fibrotic pathways in the epithelial-injury model offers a promising approach. Besides, several next-generation IPF drugs have entered phase II/III clinical trials with encouraging results. Due to the rising IPF treatment requirements, there is an urgent need to completely summarize the mechanisms, targets, problems, and drug design strategies over the past ten years. In this review, we summarize known mechanisms, target types, drug design, and novel technologies of IPF drug discovery, aiming to provide insights into the future development and clinical application of next-generation IPF drugs.

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

BACKGROUND

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

AIMS

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Targeting the deubiquitinase USP2 for malignant tumor therapy (Review)

The ubiquitin‑proteasome system is a major degradation pathway for >80% of proteins in vivo. Deubiquitylases, which remove ubiquitinated tags to stabilize substrate proteins, are important components involved in regulating the degradation of ubiquitinated proteins. In addition, they serve multiple roles in tumor development by participating in physiological processes such as protein metabolism, cell cycle regulation, DNA damage repair and gene transcription. The present review systematically summarized the role of ubiquitin‑specific protease 2 (USP2) in malignant tumors and the specific molecular mechanisms underlying the involvement of USP2 in tumor‑associated pathways. USP2 reverses ubiquitin‑mediated degradation of proteins and is involved in aberrant proliferation, migration, invasion, apoptosis and drug resistance of tumors. Additionally, the present review summarized studies reporting on the use of USP2 as a therapeutic target for malignancies such as breast, liver, ovarian, colorectal, bladder and prostate cancers and glioblastoma and highlights the current status of pharmacological research on USP2. The clinical significance of USP2 as a therapeutic target for malignant tumors warrants further investigation.

SRC and TKS5 mediated podosome formation in fibroblasts promotes extracellular matrix invasion and pulmonary fibrosis

The activation and accumulation of lung fibroblasts resulting in aberrant deposition of extracellular matrix components, is a pathogenic hallmark of Idiopathic Pulmonary Fibrosis, a lethal and incurable disease. In this report, increased expression of TKS5, a scaffold protein essential for the formation of podosomes, was detected in the lung tissue of Idiopathic Pulmonary Fibrosis patients and bleomycin-treated mice. Τhe profibrotic milieu is found to induce TKS5 expression and the formation of prominent podosome rosettes in lung fibroblasts, that are retained ex vivo, culminating in increased extracellular matrix invasion. Tks5+/- mice are found resistant to bleomycin-induced pulmonary fibrosis, largely attributed to diminished podosome formation in fibroblasts and decreased extracellular matrix invasion. As computationally predicted, inhibition of src kinase is shown to potently attenuate podosome formation in lung fibroblasts and extracellular matrix invasion, and bleomycin-induced pulmonary fibrosis, suggesting pharmacological targeting of podosomes as a very promising therapeutic option in pulmonary fibrosis.

Pulmonary inflammation and fibroblast immunoregulation: from bench to bedside

In recent years, there has been an explosion of interest in how fibroblasts initiate, sustain, and resolve inflammation across disease states. Fibroblasts contain heterogeneous subsets with diverse functionality. The phenotypes of these populations vary depending on their spatial distribution within the tissue and the immunopathologic cues contributing to disease progression. In addition to their roles in structurally supporting organs and remodeling tissue, fibroblasts mediate critical interactions with diverse immune cells. These interactions have important implications for defining mechanisms of disease and identifying potential therapeutic targets. Fibroblasts in the respiratory tract, in particular, determine the severity and outcome of numerous acute and chronic lung diseases, including asthma, chronic obstructive pulmonary disease, acute respiratory distress syndrome, and idiopathic pulmonary fibrosis. Here, we review recent studies defining the spatiotemporal identity of the lung-derived fibroblasts and the mechanisms by which these subsets regulate immune responses to insult exposures and highlight past, current, and future therapeutic targets with relevance to fibroblast biology in the context of acute and chronic human respiratory diseases. This perspective highlights the importance of tissue context in defining fibroblast-immune crosstalk and paves the way for identifying therapeutic approaches to benefit patients with acute and chronic pulmonary disorders.

Contemporary Concise Review 2022: Interstitial lung disease

Novel genetic associations for idiopathic pulmonary fibrosis (IPF) risk have been identified. Common genetic variants associated with IPF are also associated with chronic hypersensitivity pneumonitis. The characterization of underlying mechanisms, such as pathways involved in myofibroblast differentiation, may reveal targets for future treatments. Newly identified circulating biomarkers are associated with disease progression and mortality. Deep learning and machine learning may increase accuracy in the interpretation of CT scans. Novel treatments have shown benefit in phase 2 clinical trials. Hospitalization with COVID-19 is associated with residual lung abnormalities in a substantial number of patients. Inequalities exist in delivering and accessing interstitial lung disease specialist care.

Perspectives on precision cut lung slices-powerful tools for investigation of mechanisms and therapeutic targets in lung diseases

Precision cut lung slices (PCLS) have emerged as powerful experimental tools for respiratory research. Pioneering studies using mouse PCLS to visualize intrapulmonary airway contractility have been extended to pulmonary arteries and for assessment of novel bronchodilators and vasodilators as therapeutics. Additional disease-relevant outcomes, including inflammatory, fibrotic, and regenerative responses, are now routinely measured in PCLS from multiple species, including humans. This review provides an overview of established and innovative uses of PCLS as an intermediary between cellular and organ-based studies and focuses on opportunities to increase their application to investigate mechanisms and therapeutic targets to oppose excessive airway contraction and fibrosis in lung diseases.

An update on current and emerging drug treatments for idiopathic pulmonary fibrosis

INTRODUCTION

Idiopathic Pulmonary Fibrosis (IPF) is a progressive and devastating lung disease, characterized by progressive lung scarring.

AREAS COVERED

Prior to antifibrotic therapy (pirfenidone and nintedanib), there was no validated pharmaceutical therapy for IPF. Both antifibrotics can slow disease progression, however, IPF remains a detrimental disease with poor prognosis and treated survival rates of less than 7 years from diagnosis. Despite their effect the disease remains non-reversible and progressing whilst their side effect profile is often challenging. Treatment of comorbidities is also crucial. In this review, we discuss the current pharmacological management as well as management of comorbidities and symptoms. We also reviewed clinicaltrials.gov and summarised all the mid to late stage clinical trials (phase II and III) registered in IPF over the last 7 years and discuss the most promising drugs in clinical development.

EXPERT OPINION

Future for IPF management will need to focus on current unresolved issues. First a primary pathogenetic pathway has not been clearly identified. Future management may involve a combination of brushstroke approach with antifibrotics with targeted treatments for specific pathways in patient subsets following an 'oncological' approach. Another unmet need is management of exacerbations, which are deathly in most cases as well as either treating or preventing lung cancer.

Differences in Treatment Response in Bronchial Epithelial Cells from Idiopathic Pulmonary Fibrosis (IPF) Patients: A First Step towards Personalized Medicine?

Idiopathic pulmonary fibrosis (IPF) has a detrimental prognosis despite antifibrotic therapies to which individual responses vary. IPF pathology is associated with oxidative stress, inflammation and increased activation of SRC family kinases (SFK). This pilot study evaluates individual responses to pirfenidone, nintedanib and SFK inhibitor saracatinib, markers of redox homeostasis, fibrosis and inflammation, in IPF-derived human bronchial epithelial (HBE) cells. Differentiated HBE cells from patients with and without IPF were analyzed for potential alterations in redox and profibrotic genes and pro-inflammatory cytokine secretion. Additionally, the effects of pirfenidone, nintedanib and saracatinib on these markers were determined. HBE cells were differentiated into a bronchial epithelium containing ciliated epithelial, basal, goblet and club cells. NOX4 expression was increased in IPF-derived HBE cells but differed on an individual level. In patients with higher NOX4 expression, pirfenidone induced antioxidant gene expression. All drugs significantly decreased NOX4 expression. IL-6 (p = 0.09) and IL-8 secretion (p = 0.014) were increased in IPF-derived HBE cells and significantly reduced by saracatinib. Finally, saracatinib significantly decreased TGF-β gene expression. Our results indicate that treatment responsiveness varies between IPF patients in relation to their oxidative and inflammatory status. Interestingly, saracatinib tends to be more effective in IPF than standard antifibrotic drugs.

Cellular and Molecular Control of Lipid Metabolism in Idiopathic Pulmonary Fibrosis: Clinical Application of the Lysophosphatidic Acid Pathway

Idiopathic pulmonary fibrosis (IPF) is a representative disease that causes fibrosis of the lungs. Its pathogenesis is thought to be characterized by sustained injury to alveolar epithelial cells and the resultant abnormal tissue repair, but it has not been fully elucidated. IPF is currently difficult to cure and is known to follow a chronic progressive course, with the patient's survival period estimated at about three years. The disease occasionally exacerbates acutely, leading to a fatal outcome. In recent years, it has become evident that lipid metabolism is involved in the fibrosis of lungs, and various reports have been made at the cellular level as well as at the organic level. The balance among eicosanoids, sphingolipids, and lipid composition has been reported to be involved in fibrosis, with particularly close attention being paid to a bioactive lipid "lysophosphatidic acid (LPA)" and its pathway. LPA signals are found in a wide variety of cells, including alveolar epithelial cells, vascular endothelial cells, and fibroblasts, and have been reported to intensify pulmonary fibrosis via LPA receptors. For instance, in alveolar epithelial cells, LPA signals reportedly induce mitochondrial dysfunction, leading to epithelial damage, or induce the transcription of profibrotic cytokines. Based on these mechanisms, LPA receptor inhibitors and the metabolic enzymes involved in LPA formation are now considered targets for developing novel means of IPF treatment. Advances in basic research on the relationships between fibrosis and lipid metabolism are opening the path to new therapies targeting lipid metabolism in the treatment of IPF.

Inhibition of Oncogenic Src Ameliorates Silica-Induced Pulmonary Fibrosis via PI3K/AKT Pathway

Silicosis is a refractory disease. Previous studies indicate that damaged alveolar epithelial cells act as a driver in pulmonary fibrosis. Our results show that epithelial cells that acquire the mesenchymal phenotype are associated with the pathogenesis of silicosis. c-Src kinase, a non-receptor tyrosine kinase, has been shown to be a positive regulator of organ fibrosis, but specific mechanisms remain unclear and rarely researched in silicosis. The activated Phosphatidylinositol-3 kinases/AKT(PI3K/AKT) pathway promotes fibrosis. We aimed to determine whether c-Src regulates fibrosis via the PI3K/AKT signaling pathway in the development of silicosis. C57/BL mice were intratracheally perfused with 10 mg silica suspension to establish a model of silicosis. In vivo, silica particles induced lung fibrosis. The profibrotic cytokine transforming growth factor-β1 (TGF-β1) exhibited a high expression in pulmonary fibrosis. The phosphorylated c-Src protein was increased and the PI3K/AKT pathway was activated in model lung tissue. In vitro, silica increased the expression of TGF-β1- and TGF-β1-induced mesenchymal phenotype and fibrosis in a mouse epithelial cells line. siRNA-Src inhibited the c-Src, the phosphorylation of the PI3K/AKT pathway, and the mesenchymal phenotype induced by TGF-β1. LY294002, a specific inhibitor of PI3K, suppressed the phosphorylation of PI3K/AKT but did not affect Src activation. SU6656, a selective Src inhibitor, attenuated fibrosis in silicosis model. In summary, c-Src promotes fibrosis via the PI3K/AKT pathway in silica-induced lung fibrosis, and Src kinase inhibitors are potentially effective for silicosis treatment.