Idiopathic pulmonary fibrosis

Hesperidin alleviates pulmonary fibrosis by regulating EI24-mediated autophagy

BACKGROUND

Etoposide-induced protein 2.4 (EI24), an essential component of autophagy, is lowly expressed in pulmonary fibrosis. Hesperidin (Hes), a flavonoid, can regulate autophagy in various diseases. However, whether Hes can inhibit pulmonary fibrosis by mechanically regulating EI24-mediated autophagy has not been uncovered.

METHODS

RLE-6TN cells were treated with transforming growth factor β1 (TGF-β1) and rats were injected with bleomycin (BLM) to construct the pulmonary fibrosis model. The effect of Hes on pulmonary fibrosis was evaluated by cell counting kit-8, immunofluorescence, hematoxylin and eosin, masson trichome staining and western blotting.

RESULTS

Hes reduced cell viability of TGF-β1-induced RLE-6TN cells. Administration of Hes restored the decrease in autophagy marker levels in TGF-β1-induced RLE-6TN cells. Hes inhibited the transcriptional and translational levels of α-SMA, collagen I and fibronectin that were increased by TGF-β1 in RLE-6TN cells. Mechanically, Hes restored EI24 expression, and EI24 knockdown reversed the effect of Hes on the expressions of autophagy and fibrosis-related proteins. Additionally, Hes enhanced autophagy and fibrosis markers, which were worsened by EI24 knockdown in BLM-induced rats.

CONCLUSION

Hes activated autophagy by upregulating EI24, which improved pulmonary fibrosis both in vitro and in vivo.

Mai-wei-yang-fei decoction protects against pulmonary fibrosis by reducing telomere shortening and inhibiting AECII senescence via FBW7/TPP1 regulation

BACKGROUND

Pulmonary fibrosis (PF) is a fatal disease associated with ageing. The senescence of alveolar epithelial type II cells (AECIIs) can drive PF. Therefore, reducing AECII senescence is a promising treatment to prevent PF. Mai-wei-yang-fei decoction (MWYF) has shown significant clinical efficacy in the treatment of patients with PF. However, its mechanism of action remains unclear.

PURPOSE

To investigate the role and underlying mechanism of MWYF in protecting against PF.

METHODS

The main chemical components of MWYF were identified using UPLC-MS. The mouse and in vitro cell models of PF were established using BLM. Micro-CT, H&E, and Masson staining were used to observe the protective effect of MWYF on mice with PF. Immunohistochemistry, β-galactosidase staining, and IF-FISH were used to observe the inhibitory effect of MWYF on senescence and telomere shortening in mouse lung tissue or A549 cells. The Transwell assay and cell co-culture method were used to observe the effect of MWYF on the migration and activation of lung fibroblasts by inhibiting AECII senescence. Finally, lentiviral vector was used to overexpress FBW7 gene in A549 cells in vitro to observe the mechanism pathway of MWYF inhibiting AECII senescence and telomere shortening.

RESULTS

MWYF was effective in protecting against bleomycin (BLM)-induced PF. Furthermore, MWYF alleviated cellular senescence by reducing the DNA damage response (DDR) and shortening of the telomere in AECⅡs in mouse lung tissues. Mechanistically, genes related to telomere disorders were detected in BLM-induced PF mouse models using q-PCR. MWYF mainly inhibited telomere shortening by regulating FBW7 and reducing the degradation of TPP1. In vitro, MWYF reduced BLM-induced senescence in A549 cells, as well as proliferation and migration of MRC5 cells, by inhibiting DDR and telomere shortening via regulation of the FBW7/TPP1 axis.

CONCLUSION

MWYF is a potential therapeutic agent against PF, as it inhibits telomere shortening and reduces AECII senescence by regulating FBW7/TPP1.

Discovery of novel selective HDAC6 inhibitors via a scaffold hopping approach for the treatment of idiopathic pulmonary fibrosis (IPF) in vitro and in vivo

Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible, and fatal pulmonary disease. Owing to its complex pathogenesis and lack of effective treatment, patients have a short survival time after diagnosis. Although pirfenidone and nintedanib can mitigate declines in lung function, neither has stopped the progression of IPF nor significantly improved long-term survival in patients. HDAC6 inhibitors have been reported to inhibit TGF-β1-induced collagen expression to protect mice from pulmonary fibrosis, and this pharmacological mechanism has been supported by immunohistochemical studies of HDAC6 overexpression in IPF lung tissue. In this study, a series of novel derivatives were obtained based on the reported active compounds through the ring closure strategy in scaffold hopping theory. Compound W28 was selected from in vitro screening for better HDAC6 selectivity, and it was used for in-depth pharmacokinetic and pharmacodynamic studies. Detailed molecular docking studies, molecular dynamics (MD) simulations and the structure-activity relationship (SAR) discussion will contribute to guiding the design of new molecules. In further studies, the ability of W28 to inhibit the IPF phenotype was confirmed, and the corresponding pharmacological mechanism was also demonstrated. Moreover, the pharmacokinetic characteristics of W28 were also tested to guide pharmacodynamic studies in vivo, and the therapeutic effect of W28 on bleomycin-induced pulmonary fibrosis in mice was found to be satisfactory. The results reported in this paper may provide a reference for promoting the discovery of new selective HDAC6 inhibitors as drug molecules for the treatment of 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.

Cellular crosstalk in fibrosis: insights into macrophage and fibroblast dynamics

Pathological fibrosis, the excessive deposition of extracellular matrix and tissue stiffening that causes progressive organ dysfunction, underlies diverse chronic diseases. The fibrotic microenvironment is driven by the dynamic microenvironmental interaction between various cell types; macrophages and fibroblasts play central roles in fibrotic disease initiation, maintenance, and progression. Macrophage functional plasticity to microenvironmental stimuli modulates fibroblast functionality by releasing pro-inflammatory cytokines, growth factors, and matrix remodeling enzymes that promote fibroblast proliferation, activation, and differentiation into myofibroblasts. Activated fibroblasts and myofibroblasts serve as the fibrotic effector cells, secreting extracellular matrix components and initiating microenvironmental contracture. Fibroblasts also modulate macrophage function through the release of their own pro-inflammatory cytokines and growth factors, creating bidirectional crosstalk that reinforces the chronic fibrotic cycle. The intricate interplay between macrophages and fibroblasts, including their secretomes and signaling interactions, leads to tissue damage and pathological loss of tissue function. In this review, we examine macrophage-fibroblast reciprocal dynamic interactions in pathological fibrotic conditions. We discuss the specific lineages and functionality of macrophages and fibroblasts implicated in fibrotic progression, with focus on their signal transduction pathways and secretory signalling that enables their pro-fibrotic behaviour. We then finish with a set of recommendations for future experimentation with the goal of developing a set of potential targets for anti-fibrotic therapeutic candidates. Understanding the cellular interactions between macrophages and fibroblasts provides valuable insights into potential therapeutic strategies to mitigate fibrotic disease progression.

Role of Stem Cells in Ageing and Age-related Diseases

Stem cell functions and ageing are deeply interconnected, continually influencing each other in multiple ways. Stem cells play a vital role in organ maintenance, regeneration, and homeostasis, all of which decline over time due to gradual reduction in their self-renewal, differentiation, and growth factor secretion potential. The functional decline is attributed to damaging extrinsic environmental factors and progressively worsening intrinsic genetic and biochemical processes. These ageing-associated deteriorative changes have been extensively documented, paving the way for the discovery of novel biomarkers of ageing for detection, diagnosis, and treatment of age-related diseases. Age-dependent changes in adult stem cells include numerical decline, loss of heterogeneity, reduced self-renewal and differentiation, leading to a drastic reduction in regenerative potential, and thereby drive the ageing process. Conversely, ageing also adversely alters the stem cell niche, disrupting the molecular pathways underlying stem cell homing, self-renewal, differentiation, and growth factor secretion, all of which are critical for tissue repair and regeneration. A holistic understanding of these molecular mechanisms, through empirical research and clinical trials, is essential for designing targeted therapies to modulate ageing and improve health parameters in older individuals.

Genetically determined α-Klotho levels and causal association with aging-related lung diseases

BACKGROUND

Abnormal α-Klotho (KL) levels play an essential role in the pathogenesis of aging-related lung diseases. However, the correlation between circulating KL levels and aging-related lung diseases has not been determined. This study aimed to determine whether circulating KL levels causally affect aging-related lung diseases using Mendelian randomization (MR).

METHODS

Five KL-associated Single-nucleotide polymorphisms (SNPs) were analyzed using two-sample MR to assess their effects on three aging-related lung diseases: idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), and lung cancer.

RESULTS

Based on a main casual effects model with MR analyses by the inverse variance weighted (IVW) method including multiplicative random-effects model (IVW-mre) and fixed-effects inverse variance-weighted model (IVW-fe), genetically predicted circulating KL levels were negatively related with risk of IPF (Odds ratio (ORIVW-mre), 0.999, 95 % CI, 0.999-1.000, PIVW-mre = 0.008; OR IVW-fe, 0.999, 95 % CI, 0.999-1.000, PIVW-fe = 0.042). Inversely, the circulating levels of KL displayed no clear association with COPD and lung cancer. No pleiotropy was detected.

CONCLUSIONS

Genetically predicted circulating KL was causally associated with a lower risk of IPF, suggesting a protective effect in preventing IPF risk. Therefore, KL may be a promising target for the prevention and therapeutic intervention in patients with IPF.

Tryptanthrin alleviate lung fibrosis via suppression of MAPK/NF-κB and TGF-β1/SMAD signaling pathways in vitro and in vivo

Idiopathic pulmonary fibrosis (IPF), a progressive interstitial lung disease of unknown etiology, remains a therapeutic challenge with limited treatment options. This study investigates the therapeutic potential and molecular mechanisms of Tryptanthrin, a bioactive indole quinazoline alkaloid derived from Isatis tinctoria L., in pulmonary fibrosis. In a bleomycin-induced murine IPF model, Tryptanthrin administration (5 and 10 mg/kg/day for 28 days) significantly improved pulmonary function parameters and attenuated histological evidence of fibrosis. Mechanistic analysis revealed dual pathway modulation: Tryptanthrin suppressed MAPK/NF-κB signaling through inhibition of phosphorylation events, subsequently reducing pulmonary levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6). Concurrently, it attenuated TGF-β1/Smad pathway activation by decreasing TGF-β1 expression and Smad2/3 phosphorylation, thereby downregulating fibrotic markers including COL1A1, α-smooth muscle actin (α-SMA), and fibronectin in lung tissues. Complementary in vitro studies using Lipopolysaccharide (LPS) or TGF-β1-stimulated NIH3T3 fibroblasts confirmed these anti-inflammatory and anti-fibrotic effects through analogous pathway inhibition. Our findings demonstrate that Tryptanthrin exerts therapeutic effects against pulmonary fibrosis via coordinated modulation of both inflammatory (MAPK/NF-κB) and fibrotic (TGF-β1/Smad) signaling cascades, suggesting its potential as a novel multi-target therapeutic agent for IPF management.

Kynurenine acts as a signaling molecule to attenuate pulmonary fibrosis by enhancing the AHR-PTEN axis

INTRODUCTION

Pulmonary fibrosis (PF) is a fatal fibrotic lung disease without any options to halt disease progression. Feasible evidence suggests that aberrant metabolism of amino acids may play a role in the pathoetiology of PF. However, the exact impact of kynurenine (Kyn), a metabolite derived from tryptophan (Trp) on PF is yet to be addressed.

OBJECTIVES

This study aims to elucidate the role of kynurenine in both the onset and advancement of PF.

METHODS

Liquid chromatography-tandem mass spectrometry was employed to assess Kyn levels in patients with idiopathic PF and PF associated with Sjögren's syndrome. Additionally, a mouse model of PF induced by bleomycin was utilized to study the impact of Kyn administration. Furthermore, cell models treated with TGF-β1 were used to explore the mechanism by which Kyn inhibits fibroblast functions.

RESULTS

We demonstrated that high levels of Kyn are a clinical feature in both idiopathic PF patients and primary Sjögren syndrome associated PF patients. Further studies illustrated that Kyn served as a braking molecule to suppress fibroblast functionality, thereby protecting mice from bleomycin-induced lung fibrosis. The protective effects depend on AHR, in which Kyn induces AHR nuclear translocation, where it upregulates PTEN expression to blunt TGF-β mediated AKT/mTOR signaling in fibroblasts. However, in fibrotic microenviroment, the expression of AHR is repressed by methyl-CpG-binding domain 2 (MBD2), a reader interpreting the effect of DNA methylation, which results in a significantly reduced sensitivity of Kyn to fibroblasts. Therefore, exogenous administration of Kyn substantially reversed established PF.

CONCLUSION

Our studies not only highlighted a critical role of Trp metabolism in PF pathogenesis, but also provided compelling evidence suggesting that Kyn could serve as a promising metabolite against PF.

Ginseng and Platycodon grandiflorum ameliorated pulmonary fibrosis and inflammation targeting TLR4-P2X7r/NLRP3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ginseng and Platycodon grandiflorum (Jacq.) A. DC. (PG) are traditional Chinese herb medicine and classified into the lung meridian, which traditionally used to treat respiratory disorders.

AIM OF THE STUDY

This study investigated the protective mechanisms of ginseng and PG against pulmonary fibrosis.

MATERIALS AND METHODS

Panax ginseng C.A.Mey. (GS), Ginseng Radix et Rhizoma Rubra (RGR), PG and GS + PG extracts were prepared using aqueous or ethanol extraction methods and analyzed by HPLC. Cigarette smoke (CS)-induced pulmonary fibrosis mice were administrated with GS, RGR, PG, GS + PG aqueous extracts or platycodin D (PD, the major active component of PG), respectively. A549 were stimulated with different stimulators TGF-β, LPS + ATP or conditioned medium from LPS-primed THP-1 (CM), then cultured with PG, PD or A438079 (P2X7r antagonist), respectively.

RESULTS

In CS-exposed mice, GS, RGR, PG, or GS + PG extracts significantly reduced lung index elevation without effects on kidney, cardiac or liver indices. These extracts ameliorated CS-induced alveolar wall thickening, extracellular matrix (ECM) accumulation, inflammation, and inhibited P2X7r/NLRP3, TLR4/IRAK4, and NF-κB/IκB-α. PG or PD significantly alleviated lung injury and ECM deposition in CS-exposed mice. PG or PD inhibited CS-induced inflammatory cytokine secretion and immune cell recruitment by TLR4-P2X7r/NLRP3 blockade. In CM-stimulated A549, PG or PD significantly reduced ECM accumulation and inflammatory factors release. PG blocked CM-triggered TLR4-P2X7r/NLRP3 activation in A549, with similar functioning as A438079.

CONCLUSIONS

GS and PG ameliorated pulmonary fibrosis via TLR4-P2X7r/NLRP3. PG and PD regulated cell crosstalk in alveolar microenvironment against pulmonary injury, which might be novel therapeutic strategy for pulmonary fibrosis.

Blocking ATF4 attenuates pulmonary fibrosis by preventing lung fibroblast activation and macrophage M2 program

Idiopathic pulmonary fibrosis (IPF) is a devastating disease characterized by myofibroblasts accumulation and uncontrolled extracellular matrix (ECM) deposition. Here, we reported that activating transcription factor 4 (ATF4), a multifunctional transcription regulatory protein, is overexpressed in IPF lungs and mouse fibrotic lungs, mainly in myofibroblasts and macrophages. Haplodeletion of Atf4 in mice or blockage of Atf4 with Atf4 shRNA-loaded lentiviruses in mice reduced bleomycin (BLM)-induced pulmonary fibrosis (PF) in vivo. Mechanistically, we found that ATF4 directly binds to the promoter of Acta2 (encodes α-SMA), and promotes lung fibroblasts activation and myofibroblasts accumulation. Additionally, ATF4 regulates macrophage M2 program, and promotes TGFβ1 secretion by directly influencing Tgfb1 gene expression in macrophages, subsequently enhances crosstalk between macrophages and lung fibroblasts. These data suggest that strategies for inhibiting ATF4 may represent an effective treatment for PF.

Inhibition of sphingosine 1-phosphate receptor 3 ameliorates bleomycin-induced pulmonary fibrosis by suppressing macrophage M2 polarization

Pulmonary fibrosis is a devastating lung disease without effective treatment options. Sphingosine-1-phosphate receptor 3 (S1pr3), a receptor for the lipid signaling molecule sphingosine-1-phosphate, has been shown to mediate the development of pulmonary fibrosis, although the underlying mechanism is not fully understood. Here, we found increased expression of S1pr3 in the lung during the process of bleomycin-induced pulmonary fibrosis in mice and specific overexpression of S1pr3 in the infiltrated M2 macrophages. We constructed LysM-Cre + /S1pr3 flox/flox mice, in which S1pr3 was conditionally depleted in myeloid cells, and this depletion protected mice from bleomycin-induced lung injury and fibrosis, with reduced M2 macrophage accumulation in the lung. Increased S1pr3 expression was found in bone marrow-derived macrophages after alternatively activated by IL4 ex vivo, while loss of S1pr3 attenuated IL-4-induced M2 polarization in bone marrow-derived macrophages by repressing the PI3K/Akt-Stat3 signaling pathway. Moreover, the S1pr3 inhibitors CAY10444 and TY52156 exerted protective effects on pulmonary fibrosis in mice. Taken together, our research showed that inhibition of S1pr3 ameliorates bleomycin-induced pulmonary fibrosis by reducing macrophage M2 polarization via the PI3K/Akt-Stat3 signaling pathway, indicating that S1pr3 may be a potential target for pulmonary fibrosis treatment.

Ferroptosis: the potential key roles in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease characterized by recurrent injury to alveolar epithelial cells, epithelial-mesenchymal transition, and fibroblast activation, which leads to excessive deposition of extracellular matrix (ECM) proteins. However, effective preventative and therapeutic interventions are currently lacking. Ferroptosis, a unique form of iron-dependent lipid peroxidation-induced cell death, exhibits distinct morphological, physiological, and biochemical features compared to traditional programmed cell death. Recent studies have revealed a close relationship between iron homeostasis and the pathogenesis of pulmonary interstitial fibrosis. Ferroptosis exacerbates tissue damage and plays a crucial role in regulating tissue repair and the pathological processes involved. It leads to recurrent epithelial injury, where dysregulated epithelial cells undergo epithelial-mesenchymal transition via multiple signaling pathways, resulting in the excessive release of cytokines and growth factors. This dysregulated environment promotes the activation of pulmonary fibroblasts, ultimately culminating in pulmonary fibrosis. This review summarizes the latest advancements in ferroptosis research and its role in the pathogenesis and treatment of IPF, highlighting the significant potential of targeting ferroptosis for IPF management. Importantly, despite the rapid developments in this emerging research field, ferroptosis studies continue to face several challenges and issues. This review also aims to propose solutions to these challenges and discusses key concepts and pressing questions for the future exploration of ferroptosis.

"Capture and kill" circulating fibrocytes by cisplatin prodrug loaded albumin disrupt the progress of pulmonary fibrosis in mice

Pulmonary fibrosis (PF) is a progressive chronic disease characterized by a continuous decline in lung function, for which effective therapies remain elusive. Increasing evidence suggests that the recruitment of fibrocytes from the circulatory system to lungs plays a pivotal role in the pathogenesis of PF. Once into the lungs, these fibrocytes differentiate into myofibroblasts, the primary producers of extracellular collagen. Given the difficulty in reversing the disease course, targeting this key mechanism in the early stages of the disease presents a promising therapeutic strategy. To this end, we engineered a plerixafor (CXCR4 antagonist)-modified serum albumin delivery system loaded with a cisplatin prodrug (Cpro@P-SA). This system is specifically designed to target CXCR4-positive circulating fibrocytes after intravenous administration, enhance cellular uptake of Cpro@P-SA, and facilitate the intracellular conversion of cisplatin prodrug to exert its cytotoxic effects, thereby inducing fibrocytes apoptosis. Utilizing a bleomycin-induced PF mouse model, we have demonstrated that Cpro@P-SA maintains prolonged circulation, enabling it to selectively identify and eradicate recruiting fibrocytes with an optimized treatment regimen. Our results confirm that Cpro@P-SA can effectively reduce fibrocyte levels in the circulatory system, thereby mitigating PF symptoms and controlling disease progression, as evidenced by key biochemical markers and histological analyses. Furthermore, the safety of this designed system was validated through multiple evaluations. Consequently, Cpro@P-SA offers a novel and promising therapeutic approach for the treatment of early PF.

Ubiquitin-specific peptidase 10 attenuates bleomycin-induced pulmonary fibrosis via modulating autophagy depending on sirtuin 6-mediated AKT/mTOR

Idiopathic pulmonary fibrosis (IPF), characterized by fibroblast activation and collagen deposition, is a progressive lung disease that lacks effective interventions. Ubiquitin-specific peptidase 10 (USP10) acts as a multifunctional player in inflammatory response and progression of cancers, the effect on pulmonary fibrosis is unknown. Here, we demonstrated downregulated expression of USP10 in fibrotic lung tissues of IPF patients. In the current study, lung tissues were collected at the end of weeks 1, 2, or 3 post bleomycin (BLM)-intratracheal delivery. Consistently, USP10 expression levels were reduced after BLM challenge in a time-dependent manner. Mice treated with lentivirus overexpressing USP10 exhibited mitigative lung injury and reduced collagen deposition. USP10 overexpression enhanced autophagy in BLM-treated mouse lungs. Interestingly, the protective effect of USP10 was attenuated as the pulmonary autophagy flux was blocked by autophagy inhibitor 3-methyladenine (3-MA). Primary human and mouse lung fibroblasts were treated with pro-fibrotic TGF-β1 to verify the role of USP10 in vitro. Mechanically, the deubiquitinating enzyme USP10 interacted with Sirtuin 6 (Sirt6) and inhibited its degradation. Furthermore, USP10 overexpression inhibited the activation of Sirt6-mediated AKT/mTOR pathway in both lung tissues and fibroblasts. Our findings suggest that USP10 might attenuate pulmonary fibrosis through the promotion of Sirt6/AKT/mTOR-mediated autophagy. These data prioritize USP10 as a therapeutic target for treating IPF.

A Systematic Review of Mortality Risk Prediction Models for Idiopathic Pulmonary Fibrosis

Aims/Background Idiopathic pulmonary fibrosis (IPF) is associated with an increased mortality risk. However, the factors that contribute to this risk remain unknown. This study aimed to systematically review existing predictive models for IPF-related mortality and to evaluate prognostic factors associated with patient outcomes. Methods A comprehensive literature search was conducted on PubMed, Cochrane Library, Web of Science, and Embase for studies on IPF mortality risk prediction models published between 1 January 1984 and 15 November 2024. Two independent reviewers screened, extracted, and cross-checked the data. The risk of bias and model applicability were also evaluated. Results A total of 17 risk prediction models were identified. The area under the receiver operating characteristic (ROC) curve (AUC) ranged from 0.728 to 0.907, while the model validation results ranged from 0.750 to 0.920. The concordance index (C-index) of 10 studies was more than 0.7, indicating good predictive performance. This study encompassed a total of 17 risk prediction models incorporating between 3 and 8 combined prognostic variables, with the most frequently included predictors being forced vital capacity as a percentage of the predicted value (FVC%pred), carbon monoxide diffusion capacity as a percentage of the predicted value (DLCO%pred), gender, age, six-minute walk test (6MWT) results, and dyspnea severity. Conclusion Current IPF mortality risk prediction models remain in an exploratory phase, with a generally high risk of bias. Furthermore, the lack of external validation in some models limits their generalizability. Future research should focus on improving the applicability of the model to enhance clinical application.

Collagenase-functionalized Liposomes Based on Enhancing Penetration into the Extracellular Matrix Augment Therapeutic Effect on Idiopathic Pulmonary Fibrosis

In this study, a quercetin-loaded liposome system modified with collagenase was developed to increase QU penetration in the ECM and improve IPF treatment. Quercetin-loaded long circulation liposome (QU-LP) and quercetin-loaded liposome modified with collagenase type I (QU-CLP) were prepared, followed by characterization of the encapsulation efficiency, particle size, morphology, and in vitro drug release. Their effect on the cytotoxicity of A549 cells was detected by the Cell Counting Kit-8, and the cellular uptake was investigated using cellular fluorescence imaging and flow cytometry. TGF-β1 induced A549 cell model was established to mimic pulmonary fibrosis to explore further the anti-pulmonary fibrosis effect of QU-CLP by CCK8 experiment. QU-CLP significantly improves the solubility and bioavailability of QU by encapsulating it in the internal cavity with a high encapsulation efficiency (EE%) of 92.86 ± 1.03%. Liposomes alleviate the influence of QU on normal A549 cell growth. Enhanced fluorescence intensity was observed in A549 cells treated with coumarin 6-labeled and collagenase-modified nanoliposomes (C6-CLP) after 4 h of incubation on the collagen matrix, confirming that collagenase-loaded liposomes could penetrate the collagen barrier and cells internalized more hydrophobic drug. The mean fluorescence intensity (MFI) of the C6-CLP group was 2.88 times that of the C6-labeled nanoliposomes (C6-LP). Moreover, QU-CLP significantly (**P < 0.01) inhibited the proliferation of A549 cells stimulated by TGF-β1. QU-CLP has excellent potential for delivering QU with enhanced bioavailability, high cellular uptake efficiency, and improved therapeutic efficacy in IPF.

Epigenetic silencing of SOD2 exacerbates mitochondrial oxidative stress and promotes pulmonary fibrosis

Mitochondrial oxidative damage-mediated dysfunction is implicated in pulmonary pathogenesis, yet the molecular mechanisms linking redox imbalance to pulmonary fibrosis remain elusive. In this study, we demonstrate that DNA methyltransferase 3 A (DNMT3A) drives fibroblast activation and pulmonary fibrosis by epigenetically repressing superoxide dismutase 2 (SOD2), a critical antioxidant enzyme. Using fibroblast-specific DNMT3A-deficient mice and bleomycin-induced pulmonary fibrosis models, we observed that DNMT3A ablation significantly attenuated mitochondrial oxidant overproduction, restored mitochondrial membrane potential (MMP), and reduced fibrotic progression. Mechanistically, DNMT3A directly bound to the SOD2 promoter, inducing hypermethylation and transcriptional silencing, which exacerbated oxidative stress and fibroblast proliferation. Conversely, AAV6-mediated SOD2 overexpression or DNMT3A knockdown rescued SOD2 expression, suppressed mitochondrial oxidative burden, and ameliorated fibrosis. Clinically, idiopathic pulmonary fibrosis (IPF) patient tissues exhibited elevated DNMT3A levels, diminished SOD2 expression, and marked mitochondrial dysfunction, corroborating our experimental findings. These results unveil a novel DNMT3A/SOD2 axis as an epigenetic regulator of mitochondrial redox dysregulation-driven fibrosis, providing a potential therapeutic avenue for targeting oxidative damage in pulmonary fibrotic disorders.

Anti-fibrotic effects of Saengmaek-san, a prescription of traditional Korean medicine in bleomycin-induced pulmonary fibrosis mice model

ETHNOPHARMACOLOGICAL RELEVANCE

Saengmaek-san (SMS) is a herbal prescription comprising Liriope platyphylla, Panax ginseng, and Schisandra chinensis. In traditional Korean medicine (TKM), SMS has been used to treat a condition known as the dual deficiency of qi and yin in the lungs, a syndrome characterized by the depletion of vitality and body fluids, often resulting from heat exhaustion. SMS has primarily been used to promote fluid production, alleviate dry cough, and relieve progressive dyspnea.

AIM OF THE STUDY

The current study was planned to explore the efficacy and underlying mechanisms of SMS in managing idiopathic pulmonary fibrosis.

MATERIALS AND METHODS

In mice with bleomycin-induced pulmonary fibrosis, the SMS water extract was administered at doses of 50, 150, and 450 mg/kg twice daily for 14 days. The extent of pulmonary fibrosis was assessed using the Ashcroft scale in stained lung tissues. The levels of transforming growth factor-β, α-smooth muscle actin (α-SMA), and collagen accumulation were also evaluated. Bronchoalveolar lavage fluid (BALF) was collected to measure the total cell counts, white blood cell ratios, and cytokine levels (IL-6 and IL-10).

RESULTS

We observed statistically significant and potential anti-fibrotic effects in the SMS 450 mg/kg treatment group in terms of preventing body weight loss, decreasing Ashcroft scale, and reducing macrophage and granulocyte counts in BALF, as well as reducing α-SMA and collagen production. Additionally, an increase was observed in the levels of anti-inflammatory cytokine IL-10.

CONCLUSIONS

SMS demonstrated potential as a therapeutic candidate for idiopathic pulmonary fibrosis by exerting anti-inflammatory effects and reducing collagen deposition.

Targeted immunotherapy rescues pulmonary fibrosis by reducing activated fibroblasts and regulating alveolar cell profile

Idiopathic pulmonary fibrosis (IPF) is a severe lung disease occurring throughout the world; however, few clinical therapies are available for treating this disorder. Overactivated fibroblasts drive abnormal fibrosis accumulation to maintain dynamic balance between inflammation and extracellular matrix (ECM) stiffness. Given pulmonary cell can regenerate, the lung may possess self-repairing abilities if fibrosis is removed via clearance of overactivated fibroblasts. The aim of this study was to evaluate the therapeutic activity of transient antifibrotic chimeric antigen receptor (CAR) T cells (generated via a novelly-designed lipid nanoparticle-messenger RNA (LNP-mRNA) system) and explore the regeneration mechanisms of lung in a male mouse model of bleomycin-induced pulmonary fibrosis. Here we found that fibrosis-induced ECM stiffening impaired alveolar epithelial cell compensation. The proposed LNP-mRNA therapy eliminated overactivated fibroblasts to rescue pulmonary fibrosis. The restored ECM environment regulated the cellular profile. The elevated plasticity of AT2 and Pclaf+ cells increased AT1 cell population via polarization. Apoe+ macrophages and increased numbers of effector T cells were shown to reestablish pulmonary immunity. Hence, LNP-mRNA treatment for fibrosis can restore pulmonary structure and function to similar degrees to those of a healthy lung. This therapy is a potential treatment for IPF patients.

Identifying TNFSF4low-MSCs superiorly treating idiopathic pulmonary fibrosis through Tregs differentiation modulation

BACKGROUND

Idiopathic pulmonary fibrosis is a progressive lung disorder, presenting clinically with symptoms such as shortness of breath and hypoxemia. Despite its severe prognosis and limited treatment options, the pathogenesis of idiopathic pulmonary fibrosis remains poorly understood. This study aims to investigate the therapeutic potential of mesenchymal stromal cells in treating idiopathic pulmonary fibrosis, focusing on their ability to modulate regulatory T cells through the low tumor necrosis factor superfamily member 4 (TNFSF4) pathway. The goal is to identify mesenchymal stromal cells subtypes with optimal immunomodulatory effects to enhance regulatory T cells functions and ameliorate fibrosis.

METHODS

We identified the immune characteristics of idiopathic pulmonary fibrosis by mining and analyzing multiple public datasets and detecting regulatory T cells in the blood and lung tissues of idiopathic pulmonary fibrosis patients. An extensive examination followed, including assessing the impact of mesenchymal stromal cells on regulatory T cells proportions in peripheral blood and lung tissue, and exploring the specific role of TNFSF4 expression in regulatory T cells modulation. Whole-genome sequencing and cluster analysis were used to identify mesenchymal stromal cells subtypes with low TNFSF4 expression.

RESULTS

Mesenchymal stromal cells characterized by TNFSF4 expression (TNFSF4low-MSCs) demonstrated enhanced ability to regulate regulatory T cells subpopulations and exhibited pronounced anti-fibrotic effects in the bleomycin-induced idiopathic pulmonary fibrosis mouse model. These mesenchymal stromal cells increased regulatory T cells proportions, reduced lung fibrosis, and improved survival rates. TNFSF4-tumor necrosis factor receptor superfamily member 4 (TNFRSF4) signaling was identified as a critical pathway influencing regulatory T cells generation and function.

CONCLUSIONS

Our findings underscore the pivotal role of TNFSF4 in mesenchymal stromal cells mediated regulatory T cells modulation and highlight the therapeutic potential of selecting mesenchymal stromal cells subtypes based on their TNFSF4 expression for treating idiopathic pulmonary fibrosis. This approach may offer a novel avenue for the development of targeted therapies aimed at modulating immune responses and ameliorating fibrosis in idiopathic pulmonary fibrosis.

TRIAL REGISTRATION

Our study involved collecting 10 mL of peripheral blood from idiopathic pulmonary fibrosis patients, and the Medical Ethics Committee of Nanjing Drum Tower Hospital approved our study protocol with the approval number 2023-675-01.

Combination Treatment of Timosaponin BII and Pirfenidone Attenuated Pulmonary Fibrosis Through Anti-Inflammatory and Anti-Fibrotic Process in Rodent Pulmonary Fibrosis Model and Cellular Epithelial-Mesenchymal Transition Model

Pulmonary fibrosis (PF) is a progressive lung disease with a poor prognosis. Pirfenidone (PFD) can slow down the decline of lung function, but defects in efficacy and accompanying side effects limit its application; hence, implementing methods including combination therapy might be a viable option. Given this, we hypothesized that combining timosaponin BII (TS BII) with PFD might offer a more effective treatment approach. Bleomycin-induced rodent PF model and TGF-β1-induced cellular epithelial-mesenchymal transition (EMT) model were applied in the study. The results showed that the combination of TS BII and PFD was more effective in reducing the production of IL-1β, TNF-α, collagen fibers, hydroxyproline, and MDA. Moreover, the combination treatment could better restore levels SOD and GSH-Px. In addition, TS BII combined with PFD could downregulate the expression of NF-κB and the ratio of p-IκBα/IκBα, and modulate the aberrant expression of epithelial-mesenchymal transition markers. In addition, the combination treatment could regulate the intestinal flora of PF mice. It is worth noting that among the above results, there were significant differences (p < 0.05) between the combination group and either the TS BII or PFD monotherapy group. These findings indicate that the combination of TS BII and PFD has a synergistic effect in the treatment of PF and represents a promising treatment strategy.

Gui-zhi-fu-ling-wan alleviates bleomycin-induced pulmonary fibrosis through inhibiting epithelial-mesenchymal transition and ferroptosis

Background

Idiopathic pulmonary fibrosis (IPF) has a higher morbidity and poor prognosis. Gui-Zhi-Fu-Ling-Wan (GFW) is a traditional Chinese herbal formula which exerts anti-inflammatory and anti-oxidative effects. The goal was to determine the protective effect of GFW on bleomycin (BLM)-induced pulmonary fibrosis.

Methods

One hundred and twenty-four mice were randomly divided into eight groups, and orally supplemented with GFW (1 g/kg) in 1 week ago and continuing to 1 week later of single BLM intratracheal injection (5.0 mg/kg). Lung tissues were collected in 7 days and 21 days after BLM injection. BEAS-2B cells were pretreated with GFW (100 μg/mL) for three consecutive days before BLM (10 μg/mL) exposure. Cells were harvested in 12 or 24 h after BLM co-culture.

Results

GFW supplementation alleviated BLM-induced alveolar structure destruction and inflammatory cell infiltration in mice lungs. BLM-incurred collagen deposition was attenuated by GFW. In addition, GFW pretreatment repressed BLM-evoked downregulation of E-cadherin, and elevation of N-cadherin and Vimentin in mouse lungs. Besides, BLM-excited GPX4 reduction, ferritin increases, lipid peroxidation, and free iron overload were significantly relieved by GFW pretreatment in mouse lungs and BEAS-2B cells. Notably, BLM-provoked mitochondrial reactive oxygen species (mtROS) excessive production, elevation of mitochondrial stress markers, such as HSP70 and CLPP, and mitochondrial injury, were all abolished in mouse lungs and BEAS-2B cells by GFW pretreatment.

Conclusion

GFW supplementation attenuated BLM-evoked lung injury and pulmonary fibrosis partially through repressing EMT and mtROS-mediated ferroptosis in pulmonary epithelial cells.

Inhibition of sphingosine-1-phosphate receptor-2 attenuates idiopathic pulmonary fibrosis by preventing its binding to dapper1 in bronchial epithelial cells

BACKGROUND AND PURPOSE

Activation of the sphingosine-1-phosphate receptor-2 (S1P2 receptor) promotes idiopathic pulmonary fibrosis (IPF). However, the mechanisms associated with IPF development via S1P2 receptor signalling are poorly understood and no S1P2 receptor antagonists have been approved for clinical use.

EXPERIMENTAL APPROACH

Western blotting and immunohistochemical assays analysed inflammatory factors and epithelial-mesenchymal transition (EMT) markers. Co-immunoprecipitation and immunofluorescence analysed the binding of S1P2 receptor to dapper1 (Dpr1) and cyclic AMP response-binding protein 1 (CREB1). X-ray-based computed tomography diagnosed IPF in bleomycin (BLM)-treated mice. Barometric whole-body plethysmography tested pulmonary function of mice. Masson's trichrome and Sirius red staining analysed extracellular matrix deposition. Enzyme-linked immunosorbent assays analysed inflammatory factors and hydroxyproline.

KEY RESULTS

Activation of S1P2 receptors promoted IPF through the binding of S1P2 receptor to Dpr1, decreasing dishevelled (Dvl) degradation to accumulate β-catenin. The β-catenin accumulated in the nucleus, upregulating its target genes by binding to T-cell factor/lymphoid enhancer factor. The binding of S1P2 receptor to Dpr1 also led to S1P2 receptor translocation to the nucleus, where it promoted EMT by activating CREB1. BLM-induced IPF in mice was characterised by activated-S1P2 receptor signalling. Inhibition of S1P2 receptor prevented the binding of S1P2 receptor to Dpr1, resulting in decreased β-catenin accumulation and blocking nuclear translocation of S1P2 receptor. The S1P2 receptor antagonist S118 was more effective than pirfenidone in attenuating IPF through anti-inflammatory, anti-fibrosis, and anti-EMT effects.

CONCLUSIONS AND IMPLICATIONS

Activation of S1P2 receptors promotes IPF through the binding of S1P2 receptor to Dpr1 and the nuclear translocation of S1P2 receptor to activate CREB1. Thus, the S1P2 receptor antagonist S118 has potential clinical application in attenuating IPF.

Dehydrocorydaline attenuates bleomycin-induced pulmonary fibrosis by inhibiting fibroblast activation

BACKGROUND

Pulmonary fibrosis (PF) is an irreversible, progressive, chronic and fatal interstitial lung disease with limited therapeutic options. Dehydrocorydaline (DHC), derived from the traditional Chinese medicinal plant Corydalis yanhusuo, has exhibited a variety of pharmacological properties. Nevertheless, the potential function and mechanism of DHC in the management of PF have yet to be elucidated.

PURPOSE

To evaluate the therapeutical efficacy of DHC in different PF models and elucidate its underlying mechanism.

METHODS

A well-established Bleomycin-induced PF mouse model and human precision-cut lung slices (hPCLS) following fibrosis-inducing cocktail stimulation were employed. The antifibrotic effects of DHC on PF were measured by histopathological manifestation, immunofluorescent staining and expression levels of fibrosis related markers. Human primary pulmonary fibroblasts (HPFs) were used to explore the impact of DHC on fibroblast function and the underlying mechanism.

RESULTS

Here, we demonstrated that DHC exhibited a therapeutic efficacy in Bleomycin-induced PF mouse model with a dose dependent, as well as in hPCLS after fibrosis-inducing cocktail stimulation, as evidenced by histopathological staining, decrease of Fibronectin, Collagen 1 and α-SMA expression. Additionally, in vitro experiments indicated that DHC effectively suppressed fibroblast to myofibroblast transition, but had no significant effect on the proliferation and migration of fibroblast. Mechanistic studies revealed that the inhibitory effect of DHC on fibroblast activation was dependent on the endoplasmic reticulum stress, thereby inhibiting TGF-β/SMAD signal pathway.

CONCLUSIONS

Our study implied that DHC hold a promise therapeutic approach against PF by suppressing fibroblast activation. The safety and efficacy of DHC have been preliminary demonstrated in a mouse model.

Tissue-resident Klebsiella quasipneumoniae contributes to progression of idiopathic pulmonary fibrosis by triggering macrophages mitophagy in mice

Idiopathic pulmonary fibrosis (IPF) is a progressive and chronic interstitial lung disease with unclear underlying pathogenic mechanisms. Dysbiosis of the lung microbiota is believed to be associated with the development of fibrosis; however, the roles of the microbiome in the respiratory functions of hosts with IPF remain poorly understood. To investigate the relationship between the lung microbiome and the pathological processes of idiopathic pulmonary fibrosis under laboratory conditions, C57BL/6 J mice were exposed to bleomycin and observed at 7, 14, 21, and 28 days post-exposure. 16S rDNA analysis revealed that the lung microbial community exhibited dysbiosis in the bleomycin-induced pulmonary fibrosis model, characterized by an abnormally high proportion of Klebsiella quasipneumoniae (K. quasipneumoniae), as confirmed by RNA fluorescence in situ hybridization. Throughout the progression of experimental pulmonary fibrosis, Tax4Fun analysis indicated that the abundance of K. quasipneumoniae differed significantly between model mice and control mice, correlating with the sustained activation of reactive oxygen species (ROS) pathways. Importantly, the dysbiosis of K. quasipneumoniae may serve as a critical factor triggering increased ROS levels, accompanied by macrophage mitophagy, ultimately leading to the overexpression of TGF-β1, a key player in the pathogenesis of pulmonary fibrosis. These findings suggest that lung microbiota dysbiosis exacerbates the progression of bleomycin-induced pulmonary fibrosis related to macrophage mitophagy.

High matrix stiffness promotes senescence of type II alveolar epithelial cells by lysosomal degradation of lamin A/C in pulmonary fibrosis

BACKGROUND

Cellular senescence is one of the key steps in the progression of pulmonary fibrosis, and the senescence of type II alveolar epithelial cells (AEC IIs) may potentially accelerate the progression of pulmonary fibrosis. However, the molecular mechanisms underlying cellular senescence in pulmonary fibrosis remain unclear.

METHODS

The researchers first conducted in vitro experiments to investigate whether AEC IIs cultured on high matrix stiffness would lead to cellular senescence. Next, samples from mouse pulmonary fibrosis models and clinical idiopathic pulmonary fibrosis (IPF) patients were tested to observe extracellular matrix deposition, lamin A/C levels, and cellular senescence status in lung tissue. Construct lamin A/C knockdown and overexpression systems separately in AEC IIs, and observe whether changes in lamin A/C levels lead to cellular senescence. Further explore the degradation mechanism of lamin A/C using protein degradation inhibitors.

RESULTS

In vitro experiments have found that high matrix stiffness promotes senescence of AEC IIs. In a mouse model of pulmonary fibrosis, AEC IIs were found to exhibit significant cellular senescence on day 21. In clinical IPF samples, it was found that senescent cells expressed low levels of lamin A/C. In the lamin A/C SiRNA knockdown system, it was further confirmed that AEC IIs with low levels of lamin A/C are more prone to cellular senescence. Under high matrix stiffness, lamin A/C in AEC IIs is degraded through the autophagy lysosome pathway. The use of chloroquine can effectively alleviate cellular senescence.

CONCLUSIONS

High matrix stiffness degrades lamin A/C in pulmonary fibrosis through lysosomal degradation pathways, promoting AEC II senescence. Inhibition the degradation of lamin A/C could alleviate AEC II senescence.

Single-cell transcriptome analysis revealing mechanotransduction via the Hippo/YAP pathway in promoting fibroblast-to-myofibroblast transition and idiopathic pulmonary fibrosis development

OBJECTIVE

Idiopathic pulmonary fibrosis (IPF) is an irreversible and fatal interstitial lung disease, characterized by excessive extracellular matrix (ECM) secretion that disrupts normal alveolar structure. This study aims to explore the potential molecular mechanisms underlying the promotion of IPF development.

METHODS

Firstly, we compared the transcriptome and single-cell sequencing data from lung tissue samples of patients with IPF and healthy individuals. Subsequently, we conducted Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses on the differentially expressed genes (DEGs). Furthermore, we employed sodium alginate hydrogels with varying degrees of crosslinking to provide differential mechanical stress, mimicking the mechanical microenvironment in vivo during lung fibrosis. On this basis, we examined cytoskeletal remodeling in fibroblasts MRC-5, mRNA expression of multiple related genes, immunofluorescence localization, and cellular proliferation capacity.

RESULTS

Bioinformatics analysis revealed a series of DEGs associated with IPF. Further functional and pathway enrichment analyses indicated that these DEGs were primarily enriched in ECM-related biological processes. Single-cell sequencing data revealed that fibroblasts and myofibroblasts are the main contributors to excessive ECM secretion and suggested activation of mechanotransduction and the Hippo/YAP signaling pathway in myofibroblasts. Cellular experiments demonstrated that sodium alginate hydrogels with different stiffness can simulate different mechanical stress environments, thereby affecting cytoskeletal rearrangement and Hippo/YAP pathway activity in MRC-5 lung fibroblasts. Notably, high levels of mechanical stress promoted YAP nuclear translocation, increased expression of type I collagen and α-SMA, and enhanced proliferative capacity. Additionally, we also found that fibroblasts primarily participate in mechanotransduction through the Rho/ROCK and Integrin/FAK pathways under high mechanical stress conditions, ultimately upregulating the gene expression of CCNE1/2, CTGF, and FGF1.

CONCLUSION

Our study uncovers the crucial role of cytoskeletal mechanotransduction in myofibroblast transformation and IPF development through activation of the Hippo/YAP pathway, providing new insights into understanding the pathogenesis of IPF.

The dual missions of FoxO3a in inflammatory diseases: Regulation of antioxidant enzymes and involvement in programmed cell death

The transcription factor FoxO3a plays a crucial role in the process of cells adapting to various stress conditions. Multiple post - translational modifications and epigenetic mechanisms work together to precisely regulate the activity of FoxO3a, influencing its subcellular localization, stability, interactions with other proteins, DNA - binding affinity, and transcriptional regulatory capacity. Under different chemical signal stimuli and subcellular environments, the activation of FoxO3a triggered by oxidative stress can initiate diverse transcriptional programs, which are essential for the body to resist oxidative damage. In the development and progression of inflammatory diseases, FoxO3a exerts an important function by regulating the expression levels of antioxidant enzymes and participating in key physiological processes such as programmed cell death. This article comprehensively reviews the structural characteristics, mechanism of action of FoxO3a, as well as its functions in regulating antioxidant enzymes and programmed cell death. The aim is to deeply explore the potential of FoxO3a as a potential therapeutic target for preventing and treating damages such as inflammatory diseases caused by cellular stress.

Usual Interstitial Pneumonia Pattern and Mycobacteria Lung Diseases: A Case Series

BACKGROUND

Interstitial lung diseases (ILDs) are a heterogeneous group of conditions that can cause fibrosis of the lung interstitium, resulting in respiratory failure and death. Patients with an ILD, particularly idiopathic pulmonary fibrosis (IPF) or connective tissue disease-associated ILDs (CTD-ILDs), are prone to develop chronic pulmonary infections such as tuberculosis (TB) and non-tuberculous mycobacterial pulmonary disease (NTM-PD).

METHODS

This case series examines the management of three ILD patients with a usual interstitial pneumonia (UIP) pattern and concomitant NTM-PD or TB at National Institute for Infectious Diseases "Lazzaro Spallanzani" in Rome, Italy, over three years (2019-2022).

RESULTS AND CONCLUSIONS

Multi-disciplinary discussion (MDD) was crucial to define the therapeutic approach due to the increased risk of side effects and drug interactions. Our work underscored how a comprehensive diagnostic evaluation, enriched by MDD, is useful for optimizing the management and reducing drug-related adverse effects and interactions in ILD patients with cavitary lesions.

Inhaled exogenous thymosin beta 4 suppresses bleomycin-induced pulmonary fibrosis in mice via TGF-β1 signalling pathway

OBJECTIVES

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and fibrotic interstitial lung disease. The two drugs indicated for IPF have limited efficacy and there is an urgent need to develop new drugs. Thymosin β4 (Tβ4) is a natural endogenous repair factor whose antifibrotic effects have been reported. This study aimed to evaluate the effect of exogenous recombinant human thymosin beta 4 (rhTβ4) on pulmonary fibrosis.

METHODS

Pulmonary fibrosis was induced in mice with bleomycin, and rhTβ4 was administrated by nebulization following three strategies: early dosing, mid-term dosing, and late dosing. The rhTβ4 efficacy was assessed by hydroxyproline, lung function, and lung histopathology. In vitro, the effects of rhTβ4 on fibroblast and lung epithelial cell phenotypes, as well as the TGF-β1 pathway, were evaluated.

KEY FINDINGS

Aerosol administration of rhTβ4 could alleviate bleomycin-induced pulmonary fibrosis in mice at different stages of fibrosis. Studies conducted in vitro suggested that rhTβ4 could suppress lung fibroblasts from proliferating, migrating, and activation via regulating the TGF-β1 signalling pathway. In vitro, rhTβ4 also inhibited the epithelial-mesenchymal transition-like process of pulmonary epithelial cells.

CONCLUSIONS

This study suggests that nebulized rhTβ4 is a potential treatment for IPF.

ESR Essentials: imaging in fibrotic lung diseases-practice recommendations by the European Society of Thoracic Imaging

Fibrotic lung diseases (FLDs) represent a subgroup of interstitial lung diseases (ILDs), which can progress over time and carry a poor prognosis. Imaging has increased diagnostic discrimination in the evaluation of FLDs. International guidelines have stated the role of radiologists in the diagnosis and management of FLDs, in the context of the interdisciplinary discussion. Chest computed tomography (CT) with high-resolution technique is recommended to correctly recognise signs, patterns, and distribution of individual FLDs. Radiologists may be the first to recognise the presence of previously unknown interstitial lung abnormalities (ILAs) in various settings. A systematic approach to CT images may lead to a non-invasive diagnosis of FLDs. Careful comparison of serial CT exams is crucial in determining either disease progression or supervening complications. This 'Essentials' aims to provide radiologists a concise and practical approach to FLDs, focusing on CT technical requirements, pattern recognition, and assessment of disease progression and complications. Hot topics such as ILAs and progressive pulmonary fibrosis (PPF) are also discussed. KEY POINTS: Chest CT with high-resolution technique is the recommended imaging modality to diagnose pulmonary fibrosis. CT pattern recognition is central for an accurate diagnosis of fibrotic lung diseases (FLDs) by interdisciplinary discussion. Radiologists are to evaluate disease behaviour by accurately comparing serial CT scans.

Interleukin-11 Is Involved in Hyperoxia-induced Bronchopulmonary Dysplasia in Newborn Mice by Mediating Epithelium-Fibroblast Cross-talk

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a chronic lung disorder predominantly affecting preterm infants. Oxygen therapy, a common treatment for BPD, often leads to hyperoxia-induced pulmonary damage, particularly targeting alveolar epithelial cells (AECs). Crucially, disrupted lung epithelium-fibroblast interactions significantly contribute to BPD's pathogenesis. Previous studies on interleukin-11 (IL-11) in lung diseases have yielded conflicting results. Recent research, however, highlights IL-11 as a key regulator of fibrosis, stromal inflammation, and epithelial dysfunction. Despite this, the specific role of IL-11 in BPD remains underexplored. Our transcriptome analysis of normal and hyperoxia-exposed murine lung tissues revealed an increased expression of IL-11 RNA. This study aimed to investigate IL-11's role in modulating the disrupted interactions between AECs and fibroblasts in BPD.

METHODS

BPD was modeled in vivo by exposing C57BL/6J neonatal mice to hyperoxia. Histopathological changes in lung tissue were evaluated with hematoxylin-eosin staining, while lung fibrosis was assessed using Masson staining and immunohistochemistry (IHC). To investigate IL-11's role in pulmonary injury contributing to BPD, IL-11 levels were reduced through intraperitoneal administration of IL-11RαFc in hyperoxia-exposed mice. Additionally, MLE-12 cells subjected to 95% oxygen were collected and co-cultured with mouse pulmonary fibroblasts (MPFs) to measure α-SMA and Collagen I expression levels. IL-11 levels in the supernatants were quantified using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Both IHC and Masson staining revealed that inhibiting IL-11 expression alleviated pulmonary fibrosis in neonatal mice induced by hyperoxia, along with reducing the expression of fibrosis markers α-SMA and collagen I in lung tissue. In vitro analysis showed a significant increase in IL-11 levels in the supernatant of MLE-12 cells treated with hyperoxia. Silencing IL-11 expression in MLE-12 cells reduced α-SMA and collagen I concentrations in MPFs co-cultured with the supernatant of hyperoxia-treated MLE-12 cells. Additionally, ERK inhibitors decreased α-SMA and collagen I levels in MPFs co-cultured with the supernatant of hyperoxia-treated MLE-12 cells. Clinical studies found increased IL-11 levels in tracheal aspirates (TA) of infants with BPD.

CONCLUSION

This research reveals that hyperoxia induces IL-11 secretion in lung epithelium. Additionally, IL-11 derived from lung epithelium emerged as a crucial mediator in myofibroblast differentiation via the ERK signaling pathway, highlighting its potential therapeutic value in BPD treatment.

Btbd8 deficiency exacerbates bleomycin-induced pulmonary fibrosis in mice by enhancing myofibroblast accumulation and inflammatory responses

BTBD8 contributes to the pathogenesis of inflammatory bowel disease through regulating intestinal barrier integrity and inflammation. However, its role in idiopathic pulmonary fibrosis (IPF) remains unknown. Here we investigated whether BTBD8 plays a role in bleomycin-induced pulmonary fibrosis. Pulmonary fibrosis was induced in wild-type (WT) and Btbd8 knockout (KO) mice by intratracheal instillation of bleomycin. The mice were sacrificed on day 7 or 12. Subsequently, the progression of bleomycin-induced pulmonary fibrosis was assessed. We found that Btbd8 KO mice are more susceptible to bleomycin-induced pulmonary fibrosis, with more severe body weight loss and pulmonary injury, increased collagen deposition and myofibroblast accumulation. We further demonstrated that BTBD8 functions in pulmonary fibroblasts to suppress the conversion of fibroblasts to myofibroblasts. Moreover, Btbd8 deficiency promotes the infiltration of inflammatory cells and the secretion of pro-inflammatory cytokines in IPF mouse model. These results highlight the critical role of BTBD8 in the pathogenesis of bleomycin-induced pulmonary fibrosis in mice, and suggest that BTBD8 may alleviate bleomycin-induced fibrosis by suppressing the differentiation of fibroblasts to myofibroblast, as well as inflammatory responses.

Cough in idiopathic pulmonary fibrosis: what is new

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and fatal interstitial fibrosing disease and, despite some well-known risk factors, its cause is still unknown. Cough is experienced by most patients and is commonly chronic and refractory, having a significant impact on quality of life. Its aetiology is complex, combining factors related to interstitial lung disease (ILD) such as an increased sensitivity of cough-sensitive nerves, structural lung changes and inflammation, genetic factors, several comorbidities and medication-adverse effects. Despite the therapeutic advancements in IPF over the past decade with the introduction of antifibrotic drugs that slow disease progression, effective treatment options for cough in IPF remain unavailable. Cough management often relies on empirical approaches based on studies involving chronic cough patients of unspecified causes and ILD physicians' personal experiences. Different classes of medications have been tried over time and, more recently, the focus has turned to neuromodulators and opioids, but several studies have shown suboptimal efficacy in cough. On the other hand, these drugs are associated with significant physical, psychological and economic burdens. However, the future brings us hope to the extent that most current ongoing clinical trials are using new molecules and some have demonstrated promising antitussive effects. This review aims to provide a practical guide to understanding and managing cough in IPF patients, presenting pharmacological and non-pharmacological approaches over time, as well as those treatments that are currently being investigated in clinical settings.

Nintedanib improves bleomycin-induced pulmonary fibrosis by inhibiting the Clec7a/SPP1 pathway in interstitial macrophages

Idiopathic pulmonary fibrosis (IPF) is a terminal lung disease with high mortality rate. Although Nintedanib (Nin) is an effective treatment for IPF, its precise mechanism of action remains unclear. In this study, we performed an integrated analysis of single-cell sequencing and RNA-seq data from lung tissues of both fibrotic and Nin-treated fibrotic mice to uncover new therapeutic mechanisms of Nin in IPF. Our results revealed an increase in interstitial macrophages following bleomycin (BLM) treatment. We used Monocle2, Cellchat, and in vivo experiments to demonstrate that Nin can inhibit Clec7a in interstitial macrophages, thereby suppressing the SPP1-mediated profibrotic pathway. Additionally, we utilized Scenic to predict transcription factors and identified NFκB as a major transcription factor in interstitial macrophages. In the in vitro experiments, we found that inhibiting Clec7a improved the secretion of SPP1 by M2 macrophages through the NFκB pathway. In subsequent in vivo experiments, we found that inhibiting of Clec7a improves pulmonary fibrosis through the NFκB/SPP1 pathway, and Nin alleviated BLM-induced pulmonary fibrosis by inhibiting Clec7a in interstitial macrophages. In summary, our study indicates that interstitial macrophages are upregulated in pulmonary fibrosis, and Nin reduces fibrosis by inhibiting Clec7a in interstitial macrophages, which in turn diminishes the NFκB /SPP1 pathway. These findings provided a new perspective on the mechanism of action of Nin in treating pulmonary fibrosis.

Idiopathic Pulmonary Fibrosis Caused by Damaged Mitochondria and Imbalanced Protein Homeostasis in Alveolar Epithelial Type II Cell

Alveolar epithelial Type II (ATII) cells are closely associated with early events of Idiopathic pulmonary fibrosis (IPF). Proteostasis dysfunction, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction are known causes of decreased proliferation of alveolar epithelial cells and the secretion of pro-fibrotic mediators. Here, a large body of evidence is systematized and a cascade relationship between protein homeostasis, endoplasmic reticulum stress, mitochondrial dysfunction, and fibrotropic cytokines is proposed, providing a theoretical basis for ATII cells dysfunction as a possible pathophysiological initiating event for idiopathic pulmonary fibrosis.

Regorafenib exerts an inhibitory effect on the proliferation of human lung fibroblasts by reducing the production of several cytokines in vitro study

BACKGROUND

Pulmonary fibrosis is a disease that leads to respiratory failure and death. There has been little progress in therapeutic strategies for pulmonary fibrosis. There have been several reports on the cytokines associated with pulmonary fibrosis, including IL-6 and TGF-β1. Angiogenesis is one of the most important phenomena in the pathogenesis of pulmonary fibrosis. Previously, we reported the preventive effects of thalidomide against pulmonary fibrosis via the inhibition of neovascularization by angiogenic factors such as VEGF. Regorafenib is a multikinase inhibitor, which inhibits tyrosine kinase receptors such as VEGFR1-3 and TIE2. In the clinical setting, regorafenib has been widely used for anti-cancer therapy for metastatic colorectal cancer. In this study, we examined the preventive effects of regorafenib against pulmonary fibrosis.

METHODS

We investigated whether regorafenib had an inhibitory effect on the proliferation, viability, and production of several cytokines in lung fibroblasts.

RESULTS

We demonstrated an inhibitory effect of regorafenib on the proliferation and viability of lung fibroblasts. Moreover, regorafenib reduced the production of several cytokines associated with the pathogenesis of pulmonary fibrosis, including IL-6, VEGF and TGF- β1, and collagen synthesis from lung fibroblasts.

CONCLUSIONS

These data suggest that regorafenib may have potential clinical applications in the prevention of pulmonary fibrosis.

Visual Diagnosis of Drug-Induced Pulmonary Fibrosis Based on a Mitochondrial Viscosity-Activated Red Fluorescent Probe

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and irreversible fatal disease, the prevalence of which has been increasing in recent years. Nonradiographic and noninvasive early diagnosis of pulmonary fibrosis could improve prognosis but is a formidable challenge. As one of the fundamental microenvironmental parameters, viscosity is relevant to various pathological states, such as acute inflammation. Nevertheless, the potential biological roles of viscosity during the IPF process have been relatively underexplored. To address this issue, herein, we developed a new viscosity-responsive probe (JZ-2), which displayed high sensitivity and selectivity for viscosity, as well as excellent characteristics for targeting mitochondria. JZ-2 was successfully applied to map the changes in mitochondrial viscosity in cells caused by various stimuli, such as nystatin and lipopolysaccharide. Besides, JZ-2 was capable of differentiating cancer cells from normal cells and even tissues. More importantly, JZ-2 has been demonstrated to be sufficiently sensitive for tumor detection and early identification of IPF in vivo, revealing a significant increase in the viscosity of lung fibrosis tissues. Thus, JZ-2 is expected to be a swift and reliable diagnostic modality for the prediction of IPF progression in clinical settings.

Inhalable Hsa-miR-30a-3p Liposomes Attenuate Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) remains an incurable form of interstitial lung disease with sub-optimal treatments that merely address adverse symptoms or slow fibrotic progression. Here, inhalable hsa-miR-30a-3p-loaded liposomes (miR-30a) for the treatment of bleomycin-induced pulmonary fibrosis in mice are presented. It was previously found that exosomes (Exo) derived from lung spheroid cells are therapeutic in multiple animal models of pulmonary fibrosis and are highly enriched for hsa-miR-30a-3p. The present study investigates this miRNA as a singular factor to treat IPF. Liposomes containing miR-30a mimic can be delivered to rodents through dry powder inhalation. Inhaled miR-30a and Exo consistently lead to improved pulmonary function across six consecutive pulmonary function tests and promote de-differentiation of profibrotic myofibroblasts. The heterogenous composure of Exo also promotes reparative alveolar type I and II cell remodeling and vascular wound healing through broad transforming growth factor-beta signaling downregulation, while miR-30a targets myofibroblast de-differentiation through CNPY2/PERK/DDIT3 signaling. Overall, inhaled miR-30a represses the epithelial-mesenchymal transition of myofibroblasts, providing fibrotic attenuation and subsequent improvements in pulmonary function.

Targeted therapy for idiopathic pulmonary fibrosis: a bibliometric analysis of 2004-2024

Background

Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible interstitial lung disease characterized by high mortality rates. An expanding body of evidence highlights the critical role of targeted therapies in the management of IPF. Nevertheless, there is a paucity of bibliometric studies that have comprehensively assessed this domain. This study seeks to examine global literature production and research trends related to targeted therapies for IPF.

Method

A literature search was conducted using the Web of Science Core Collection, encompassing publications from 2004 to 2024, focusing on targeted therapies for IPF. The bibliometric analysis utilized tools such as VOSviewer, CiteSpace, and the "bibliometrix" package in R.

Results

A total of 2,779 papers were included in the analysis, demonstrating a general trend of continuous growth in the number of publications over time. The United States contributed the highest number of publications, totaling 1,052, while France achieved the highest average citation rate at 75.74. The University of Michigan Medical School was the leading institution in terms of publication output, with 88 papers. Principal Investigator Naftali Kaminski was identified as the most prolific researcher in the field. The American Journal of Respiratory Cell and Molecular Biology emerged as the journal with the highest number of publications, featuring 98 articles. In recent years, the research has emerged surrounding targeted therapies for IPF, particularly focusing on agents such as TGF-β, pathogenesis, and autotaxin inhibitor.

Conclusion

In this bibliometric study, we systematically analyze research trends related to targeted therapies for IPF, elucidating recent research frontiers and emerging directions. The selected keywords-idiopathic pulmonary fibrosis, targeted therapy, bibliometric analysis, transforming growth factor β, and autotaxin inhibitor-capture the essential aspects of this research domain. This analysis serves as a reference point for future investigations into targeted therapies.

Impact of the Human Leukocyte Antigen Complex on Idiopathic Pulmonary Fibrosis Development and Progression in the Sardinian Population

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease characterized by the disruption of the alveolar and interstitial architecture due to extracellular matrix deposition. Emerging evidence suggests that genetic susceptibility plays a crucial role in IPF development. This study explores the role of human leukocyte antigen (HLA) alleles and haplotypes in IPF susceptibility and progression within the genetically distinct Sardinian population. Genotypic data were analyzed for associations with disease onset and progression, focusing on allele and haplotype frequencies in patients exhibiting slow (S) or rapid (R) progression. While no significant differences in HLA allele frequencies were observed between IPF patients and controls, the HLA-DRB1*04:05 allele and the extended haplotype (HLA-A*30:02, B*18:01, C*05:01, DQA1*05:01, DQB1*02:01, DRB1*03:01) were associated with a slower disease progression and improved survival (log-rank = 0.032 and 0.01, respectively). At 36 months, carriers of these variants demonstrated significantly better pulmonary function, measured with single-breath carbon monoxide diffusing capacity (DLCO%p) (p = 0.005 and 0.02, respectively). Multivariate analysis confirmed these findings as being independent of confounding factors. These results highlight the impact of HLA alleles and haplotypes on IPF outcomes and underscore the potential of the Sardinian genetic landscape to illuminate immunological mechanisms, paving the way for predictive biomarkers and personalized therapies.

Cost-effectiveness of novel diagnostic tools for idiopathic pulmonary fibrosis in the United States

OBJECTIVES

Novel non-invasive machine learning algorithms may improve accuracy and reduce the need for biopsy when diagnosing idiopathic pulmonary fibrosis (IPF). We conducted a cost-effectiveness analysis of diagnostic strategies for IPF.

METHODS

We developed a decision analytic model to evaluate diagnostic strategies for IPF in the United States. To assess the full spectrum of costs and benefits, we compared four interventions: a machine learning diagnostic algorithm, a genomic classifier, a biopsy-all strategy, and a treat-all strategy. The analysis was conducted from the health sector perspective with a lifetime horizon. The primary outcome measures were costs, Quality-Adjusted Life-Years (QALYs) gained, and Incremental Cost-Effectiveness Ratios (ICERs) based on the average of 10,000 probabilistic runs of the model.

RESULTS

Compared to a biopsy-all strategy the machine learning algorithm and genomic classifer reduced diagnostic-related costs by $14,876 and $3,884, respectively. Use of the machine learning algorithm consistently reduced diagnostic costs. When including downstream treatment costs and benefits of anti-fibrotic treatment, the machine learning algorithm had an ICER of $331,069 per QALY gained compared to the biopsy-all strategy. The genomic classifier had a higher ICER of $390,043 per QALY gained, while the treat-all strategy had the highest ICER of $3,245,403 per QALY gained. Results were sensitive to changes in various input parameters including IPF treatment costs, sensitivity and specificity of novel screening tools, and the rate of additional diagnostics following inconclusive results. High treatment costs were found to drive overall cost regardless of the diagnostic method. As treatment costs lowered, the supplemental diagnostic tools became increasingly cost-effective.

CONCLUSIONS

Novel tools for diagnosing IPF reduced diagnostic costs, while overall incremental cost-effectiveness ratios were high due to treatment costs. New IPF diagnosis approaches may become more favourable with lower-cost treatments for IPF.

Identification and validation of biomarkers related to ferroptosis in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a kind of interstitial lung disease (ILD). It has a high incidence rate and mortality. Its pathogenesis remains unclear. So far, no effective methods have been found for the early diagnosis of IPF. Ferroptosis has been reported to be critical in the initiation and progression of IPF. Therefore, our aim was to identify the hub gene related to ferroptosis co-expressed in the peripheral blood and pulmonary tissue of patients with IPF. Sequencing data were obtained from the Gene Expression Omnibus database. A comprehensive analysis was conducted on the differentially expressed genes (DEGs) to extract ferroptosis-related differentially expressed genes (FRDEGs). The results showed that ferroptosis-related signal paths were highly enriched in IPF, and 10 FRDEGs were identified.The hub gene was predicted through protein-protein interactions (PPI) and Cytoscape. The diagnostic utility of the hub gene was proven by enzyme-linked immunosorbent assay (ELISA) in serum and by immunohistochemistry (IHC) in pulmonary tissues. The results of ELISA indicated that the levels of ATM in the serum of patients with IPF were significantly lower than the normal levels. In contrast, the results of IHC showed that the expression of ATM in the pulmonary tissues of IPF patients exhibited a notably elevated trend. The immune status was assessed by the CIBERSORT method and so was the relevance between ATM and immune cells. These findings unveiled significant differences in various immune cell types in peripheral blood and pulmonary tissue between the IPF group and the control group. Furthermore, ATM was associated with various immune cells. This study suggests that as a ferroptosis-related gene, ATM assumes a pivotal role in the diagnosis and treatment of IPF. This discovery presents a novel approach for the clinical diagnosis and therapy of IPF.

Intranasal delivery of extracellular vesicles: A promising new approach for treating neurological and respiratory disorders

BACKGROUND

Extracellular vesicles (EVs) are membrane vesicles secreted by all types of cells, including bacteria, animals, and plants. These vesicles contain proteins, nucleic acids, and lipids from their parent cells and can transfer these components between cells. EVs have attracted attention for their potential use in diagnosis and therapy due to their natural properties, such as low immunogenicity, high biocompatibility, and ability to cross the blood-brain barrier. They can also be engineered to carry therapeutic molecules. EVs can be delivered via various routes. The intranasal route is particularly advantageous for delivering them to the central nervous system, making it a promising approach for treating neurological disorders.

SCOPE OF REVIEW

This review delves into the promising potential of intranasally administered EVs-based therapies for various medical conditions, with a particular focus on those affecting the brain and central nervous system. Additionally, the potential use of these therapies for pulmonary conditions, cancer, and allergies is examined, offering a hopeful outlook for the future of medical treatments.

MAJOR CONCLUSIONS

The intranasal administration of EVs offers significant advantages over other delivery methods. By directly delivering EVs to the brain, specifically targeting areas that have been injured, this administration proves to be highly efficient and effective, providing reassurance about the progress in medical treatments. Intranasal delivery is not limited to brain-related conditions. It can also benefit other organs like the lungs and stimulate a mucosal immune response against various pathogens due to the highly vascularized nature of the nasal cavity and airways. Moreover, it has the added benefit of minimizing toxicity to non-targeted organs and allows the EVs to remain longer in the body. As a result, there is a growing emphasis on conducting clinical trials for intranasal administration of EVs, particularly in treating respiratory tract pathologies such as coronavirus disease.

Involvement of lncRNA MIR205HG in idiopathic pulmonary fibrosis and IL-33 regulation via Alu elements

Idiopathic pulmonary fibrosis (IPF) causes remodeling of the distal lung. Pulmonary remodeling is histologically characterized by fibrosis, as well as appearance of basal cells; however, the involvement of basal cells in IPF remains unclear. Here, we focus on the long noncoding RNA MIR205HG, which is highly expressed in basal cells, using RNA sequencing. Through RNA sequencing of genetic manipulations using primary cells and organoids, we discovered that MIR205HG regulates IL-33 expression. Mechanistically, the AluJb element of MIR205HG plays a key role in IL-33 expression. Additionally, we identified a small molecule that targets the AluJb element, leading to decreased IL-33 expression. IL-33 is known to induce type 2 innate lymphoid cells (ILC2s), and we observed that MIR205HG expression was positively correlated with the number of ILC2s in patients with IPF. Collectively, these findings provide insights into the mechanisms by which basal cells contribute to IPF and suggest potential therapeutic targets.

Targeted imaging of pulmonary fibrosis by a cyclic peptide LyP-1

Pulmonary fibrosis (PF) is an interstitial chronic lung disease characterized by interstitial inflammation and extracellular matrix deposition, resulting in progressive lung dysfunction and ultimate respiratory failure. However, lacking of precise and noninvasive tracers for fibrotic lesions limits timely diagnosis and treatment. Here, we identified LyP-1, a cyclic peptide, as a specific and sensitive tracer for PF detection using PET/CT imaging. FITC-LyP-1 selectively recognized fibrotic regions in bleomycin-induced PF mice, indicating its targeting capability. The colocalization of FITC-LyP-1 with extracellular collagen I within the fibrotic lesions validated its specificity, and further analysis revealed several potential target molecules. In the in vivo application studies, radiolabeled [68Ga]Ga-LyP-1 showed significantly increased lung uptake in PF mice, specifically enriching fibrotic regions on PET/CT imaging. Notably, compared to CT imaging that showed increased mean lung density throughout the phases after bleomycin-administration, lung uptake of [68Ga]Ga-LyP-1 was only increased in the later phase, indicating that LyP-1 recognizes the fibrous changes rather than the inflammatory cells in vivo. These results suggest that the new radiotracer [68Ga]Ga-LyP-1 specifically detects the extracellular matrix in fibrotic lungs. LyP-1 shows promise as a noninvasive tracer for assessing human pulmonary fibrosis, offering potential for improved diagnostic accuracy and timely intervention.

Design, synthesis, and biological evaluation of a potent and orally bioavailable FGFRs inhibitor for fibrotic treatment

Organ fibrosis, such as lung fibrosis and liver fibrosis, is a progressive and fatal disease. Fibroblast growth factor receptors (FGFRs) play an important role in the development and progression of fibrosis. Through scaffold hopping, bioisosteric replacement design, and structure-activity relationship optimization, we developed a series of highly potent FGFRs inhibitors, and the indazole-containing candidate compound A16 showed potent kinase activity comparable to that of AZD4547. In addition, A16 effectively suppressed the activation of lung fibroblasts and hepatic stellate cells (HSCs) induced by TGF-β1, leading to a reduction in collagen deposition. Notably, A16 exhibited potent anti-fibrotic effects through the inhibition of the FGFR pathway in vitro. Compound A16 also showed reasonable pharmacokinetic properties (F = 21.84 %) and favorable cardiac safety (hERG IC50 > 20 μM). Moreover, in models of pulmonary fibrosis, A16 ameliorated (in the prevention model) and reversed (in the treatment model) bleomycin-induced lung fibrosis, as well as mitigated inflammatory immune response in the lung. Furthermore, in the CCl4-induced liver fibrosis model, when A16 was administrated orally at a dose of 30 mg/kg/day for 3 weeks, it effectively improved liver function, restored damaged liver structures, and reduced collagen deposition. Taken together, these results suggest that A16 could be a potential drug candidate for the treatment of organ fibrosis.

Decreased Complex I Activity in Blood lymphocytes Correlates with Idiopathic Pulmonary Fibrosis Severity

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease linked to aging. Mitochondrial dysfunction in circulating T cells, often caused by disruption of mitochondrial DNA (mtDNA), may play a role in age-related conditions like IPF. In our previous study, we found high mtDNA mutational loads in blood lymphocytes from IPF patients, especially in regions critical for mtDNA expression. Since Complex I of the electron transport chain, partly encoded by mtDNA, is essential for energy production, we conducted a preliminary study on its activity. We found significantly reduced Complex I activity (p < 0.001) in lymphocytes from 40 IPF patients compared to 40 controls, which was positively correlated with lung function decline, specifically in functional vital capacity and diffusing capacity for carbon monoxide. These findings indicate that T cell mitochondrial dysfunction is associated with disease progression in IPF. Future work will explore the mechanisms linking T cell mitochondrial disruption with fibrosis, potentially uncovering new therapeutic targets.