Idiopathic pulmonary fibrosis: Disease mechanisms and drug development

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.

Isomeric 2-isobutylmalate derivatives with anti-pulmonary fibrosis effects from the leaves of Bletilla striata via LC-MS/MS-based molecular networking

Based on the LC-MS/MS molecular networking strategy, nine undescribed 2-isobutylmalate derivatives, namely bletistrosides M-U (compounds 1-7, 9, and 11), together with two known analogues (compounds 8 and 10), were isolated and identified from the leaves of Bletilla striata. Their structures with absolute configurations were deduced from spectroscopic data, acidic hydrolysis, and comparison with reported compounds. Compounds 1/2, 3/4, 5/6, and 7/8 represented four pairs of Z/E isomers regarding cinnamoyl groups, and each pair underwent interconversion under UV radiation at 254 nm. Biologically, compounds 1, 2, and 10 exhibited anti-pulmonary fibrosis effects against bleomycin-stimulated cell injury in A549 cells. Further investigations demonstrated that the anti-pulmonary fibrosis potential of 2 was related to the inhibition of apoptosis and epithelial-mesenchymal transition by blocking the Bax/Bcl-2, TGF-β1/Smad2/3, and PI3K/AKT signaling pathways, while concurrently enhancing the Nrf2 signaling pathway.

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.

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.

Edible and Medicinal Fungi as Candidate Natural Antidepressants: Mechanisms and Nutritional Implications

This systematic review examines the antidepressant potential of edible medicinal fungi (EMFs), focusing on their bioactive compounds and mechanisms of action. EMFs modulate neurotransmitter systems, including serotonin (5-HT) and dopamine (DA), alleviating depressive symptoms. Extracts from EMFs, such as Ganoderma lucidum, Hericium erinaceus, Poria cocos, and Cordyceps militaris, demonstrate significant antidepressant-like effects in preclinical studies. Their bioactive compounds influence the tryptophan-kynurenine (KYN) pathway, regulate the hypothalamus-pituitary-adrenal (HPA) axis, and reduce neuroinflammation, all of which are linked to stress response and mood regulation. The review also explores the gut-brain axis, highlighting how EMF-derived polysaccharides improve gut health by modulating microbiota, potentially mitigating depressive symptoms. Additionally, it discusses the use of EMFs in functional foods and dietary supplements, innovations like 3D food printing for depression-related issues, and synthetic biology for enhancing compound production. Artificial intelligence is used to model complex mechanisms. However, challenges remain, such as standardization and lack of clinical validation. Future research should address these gaps, emphasizing personalized interventions and advanced technologies for next-generation antidepressant foods.

CCTα and GVI iPLA2-induced aberrant phosphatidylcholine metabolism contributes to pulmonary inflammation and fibrosis

To date, no comprehensive profiling of phosphatidylcholine (PC) and lysophosphatidylcholine (LPC) with pulmonary inflammation and fibrosis has been published. Our study aimed to analyze PC and LPC metabolism with the development and persistence of pulmonary inflammation and the progression to fibrosis; and their relationship. Mice and cell models exposed to bleomycin and/or transforming growth factor-β1 (TGF-β1) were developed; and porcine surrogates for pulmonary fibrosis were included. Histopathological, immunofluorescence and immunohistochemical staining, transmission electron microscopy, colorimetric, activity and immune complex (IC) assay, lipidomics analysis; and pharmacological intervention assay were used to analyze PC and LPC profile, pulmonary fibrosis and their relationship. Current evidence suggests that 16:0 20:5 PC is a conserved biomarker; and 16:0 18:1 PC, 16:0 18:2 PC; and 16:0 LPC are the potential targets for this disease. Specifically, 16:0 18:1 PC accumulation and exogenous treatment affected lung cell recruitment, migration, transformation, cross-talk, survival/death; and enhanced profibrotic factor release, IC and extracellular matrix (ECM) deposition, where CTP:phosphocholine cytidylyltransferase α (CCTα) and group VI Ca2+-independent phospholipase A2 (GVI iPLA2) play an important role, particularly in lung and spleen neutrophils, macrophages, and T lymphocytes. Overall, these results provide new insights into how the dysregulated PC metabolism, particularly for 16:0 18:1 PC, affects the development and persistence of lung inflammation and the progression to fibrosis, and thus may facilitate the discovery of biomarkers and targets for this disease.

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.

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.

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.

Broad antifibrotic activities of AK3280 in pulmonary, hepatic, cardiac, and skin fibrosis animal models

Fibrosis is the pathological outcome of many chronic inflammatory diseases, affecting various human organs. It is a significant contributor to global morbidity and mortality that affects nearly half of the elderly population. Pirfenidone (PFD) and nintedanib are approved by the FDA for treating pulmonary fibrosis, but these treatments are associated with poor tolerability and limited efficacy. Moreover, no antifibrotic drugs are approved for other fibrosis-related diseases, highlighting an urgent unmet medical need for more effective therapies. Here we report the in vivo pharmacological activities of AK3280, a novel, orally bioavailable small molecule designed to enhance pharmacokinetics, antifibrotic activity, and tolerability over PFD. AK3280 demonstrated antifibrotic effects across multiple organs, including the lungs, liver, heart, and skin, in various animal models. These results suggest that AK3280 holds promise as a clinically beneficial antifibrotic therapy for a range of fibrotic diseases, especially pulmonary, hepatic, cardiac, and skin fibrosis.

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

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

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

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.

Protective Effects of Qingre Sanjie Jiaonang on Pulmonary Fibrosis: A Pilot Study

Background

Qingre Sanjie Jiaonang (QRSJ) is a single herbal preparation from Senecio scandens Buch.-Ham.ex D. Don which has been proved to have anti-inflammatory and antioxidant effects. QRSJ has been used in treating upper respiratory tract inflammation and acute bronchitis in China for nearly twenty years.

Purpose

This study aims to explore the potential effects of QRSJ in alleviating pulmonary fibrosis (PF) and its mechanisms.

Study Design and Method

A mouse model of PF was induced by intratracheal injection of Bleomycin (BLM, 5 mg/kg), followed by different doses of QRSJ administration (0.5 g/kg, 1.0 g/kg) for 28 days. The lung tissues were collected and prepared for Hematoxylin-Eosin (H&E) staining to observe the pathological changes, while Masson staining was for determining collagen production. RNA sequencing (RNA-seq), flow cytometry and immunofluorescence experiments were employed to investigate the impact of QRSJ on the immune microenvironment. The expression levels of IL-1β, IL-6, CXCL15 (mouse homologue of human IL-8), and TNF-α in the bronchoalveolar lavage fluid (BALF) and serum of mice were observed. Besides, the levels of high mobility group protein B1 (HMGB1), an inflammatory and profibrotic mediator, in the BALF, serum and lung tissues of mice were also detected.

Results

The mouse model of PF was successfully established by checking the pathological examinations. With QRSJ intervention, BLM-induced destruction of alveolar structure and inflammatory cell infiltration were alleviated. H&E results further revealed that the administration of BLM and QRSJ had no impact on kidney histological structure of mice. Meanwhile, QRSJ inhibited the deposition of collagen, decreased the expression of fibronectin and lumican. Next, QRSJ treatment improved immune cell infiltration in the lung, along with the down-regulation of CD45 and Ly6G, and led to a decrease in the immune cell count in BALF. Furthermore, QRSJ alleviated the release of inflammatory factors, including NE, IL-1β, IL-6, CXCL15, and TNF-α. Besides, QRSJ significantly reduced the level of proinflammatory cytokine HMGB1.

Conclusion

This study demonstrated the benefits of QRSJ in improving the pathological abnormalities in a PF model, revealing the new potential of the old drug. It should be attributed to the regulation of abnormal immune microenvironment and HMGB1 release. Future efforts should focus on its specific pharmacological mechanisms and clinical outcomes.

PI3K/Akt in IPF: untangling fibrosis and charting therapies

Idiopathic Pulmonary Fibrosis (IPF) is a chronic, progressive lung disease characterized by abnormal epithelial repair, persistent inflammation, and excessive extracellular matrix deposition, leading to irreversible scarring and respiratory failure. Central to its pathogenesis is the dysregulation of the PI3K/Akt signaling pathway, which drives fibroblast activation, epithelial-mesenchymal transition, apoptosis resistance, and cellular senescence. Senescent cells contribute to fibrosis through the secretion of pro-inflammatory and profibrotic factors in the senescence-associated secretory phenotype (SASP). Current antifibrotic therapies, Nintedanib and Pirfenidone, only slow disease progression and are limited by side effects, highlighting the need for novel treatments. This review focuses on the role of PI3K/Akt signaling in IPF pathogenesis, its intersection with inflammation and fibrosis, and emerging therapeutic approaches targeting molecules along this pathway.

Is Inducible Nitric Oxide Synthase (iNOS) Promising as a New Target Against Pulmonary Hypertension?

Pulmonary hypertension (PH) is a progressive disease characterized by elevated blood pressure in the pulmonary arteries, associated also with inflammation and oxidative stress. Inducible nitric oxide synthase (iNOS) is one of the key mediators of inflammation and immune system activation. Although preclinical studies mostly suggest a detrimental role of iNOS overactivation in PH, there is a lack of exhaustive analyses and summaries. Therefore, this literature overview aims to fill this gap. The involvement of iNOS in the pathogenesis of the four main clinical groups of PH is discussed to assess whether targeting iNOS could be a promising way to treat PH. iNOS expression patterns in the organs primarily affected by PH are analyzed both in animals and in humans. Consequently, the effectiveness of pharmacological iNOS inhibition and/or iNOS gene deletion is discussed and compared, also with reference to the activity of constitutive NOS isoforms, particularly endothelial NOS (eNOS). Overall, our overview suggests that selective iNOS inhibitors could be considered as a novel treatment strategy for PH, as decreases in right ventricular and pulmonary artery pressure, the alleviation of ventricular hypertrophy, and improvements of pulmonary and cardiac function were observed, among others. Nevertheless, further research efforts in this area are needed.

Activin A Inhibitory Peptides Suppress Fibrotic Pathways by Targeting Epithelial-Mesenchymal Transition and Fibroblast-Myofibroblast Transformation in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and incurable chronic interstitial lung disease characterized by excessive fibrosis and impaired lung function. Current treatments, such as pirfenidone and nintedanib, slow disease progression but fail to halt or reverse fibrosis, highlighting the need for novel approaches. Activin A, which belongs to the TGF-β superfamily, is implicated in various fibrosis-related mechanisms, including epithelial-mesenchymal transition (EMT), a process where epithelial cells acquire mesenchymal characteristics, and fibroblast-myofibroblast transformation (FMT), in which fibroblasts differentiate into contractile myofibroblasts. It also promotes inflammatory cytokine release and extracellular matrix buildup. This study aimed to inhibit Activin A activity using synthetic peptides identified through phage display screening. Of the ten peptides isolated, A7, B9, and E10 demonstrated high binding affinity and inhibitory activity. Computational modeling confirmed that these peptides target the receptor-binding domain of Activin A, with peptide E10 exhibiting superior efficacy. Functional assays showed that E10 reduced cell migration, inhibited EMT in A549 cells, and suppressed FMT in fibroblast cultures, even under pro-fibrotic stimulation with TGF-β. These findings underscore the therapeutic potential of targeting Activin A with synthetic peptides, offering a promising avenue for IPF treatment and expanding the arsenal of anti-fibrotic strategies.

Fritillaria thunbergii Miq. Extract ameliorated experimental pulmonary fibrosis partly through the PI3K/AKT/FOXO signalling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Pulmonary fibrosis is an irreversible lung disease with a high mortality rate. Zhebeimu (ZBM, Fritillaria thunbergii Miq.) is a Chinese medicine commonly used for the treatment of pulmonary fibrosis in China.

AIM OF THE STUDY

In this study, the protective effect and mechanism of ZBM extract in the treatment of pulmonary fibrosis were investigated in vivo and in vitro.

MATERIALS AND METHODS

The protective effect of ZBM extract was assessed using an in vivo model of bleomycin (BLM) tracheal drip and transforming growth factor-β(TGF-β1)-induced fibroblasts to simulate pulmonary fibrosis, and lung function, lung histopathological status and hydroxyproline were tested. Relevant pathways were detected using protein blotting, immunofluorescence and immunohistochemistry.

RESULTS

ZBM extract effectively improved lung function, inflammatory changes and fibrotic deposition in the lungs, and reduced the expression of fibroblast markers in mice. In addition, ZBM extract significantly inhibited TGF-β1-induced hyperphosphorylation of FOXO3, and simultaneously improved the low expression level of FOXO3 prototype protein and significantly reduced the phosphorylation level of PI3K-p85 and AKT1, suggesting that ZBM extract improves lung fibrosis by inhibiting the over-activation of PI3K/AKT/FOXO signalling pathway.

CONCLUSION

The PI3K/AKT/FOXO signalling pathway is critical for ZBM extract to improve pulmonary fibrosis.

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.

Citrus pectin-coated inhalable PLGA nanoparticles for treatment of pulmonary fibrosis

Pulmonary fibrosis (PF) is a chronic interstitial disorder of the respiratory system that can be debilitating as it progresses and has experienced a slow rise in incidence in past years. Treatment is complicated by the complex aetiology of the disease and the off-target effects of the two FDA-approved therapeutics available on the market: pirfenidone and nintedanib. In this work, we propose a multipurpose nanoparticle system consisting of poly(lactic-co-glycolic) acid polymer (PLGA) and a coating of citrus pectin (CP) for galectin-3 targeting and anti-fibrotic therapy. Pectin from citrus peels has been observed to have anti-fibrotic activity in a range of fibrotic tissues, causing a decrease in the expression and activity of galectin-3: a key, upregulated marker of fibrosis. We show that the CP-PLGA nanoparticles (NPs) have an average diameter of 340.5 ± 10.6 nm, compatible with inhalation and retention in the deep lung, and that CP constitutes, on average, 40.3% of the final CP-PLGA formulation. The NPs are well-tolerated by MRC-5 lung fibroblasts up to 2 mg mL-1. We demonstrate the NPs' ability to target transforming growth factor β (TGFβ)-treated fibrotic MRC-5 cells in a specific, dose-dependent manner, saturating at approx. 250 μg mL-1in vitro, and that our NPs have potent anti-fibrotic activity in vivo in particular, reversing bleomycin-induced fibrosis in mouse lungs, accompanied by marked reduction in profibrotic markers including collagen 1, fibronectin, α-smooth muscle actin, β-catenin and galectin-3. In all, we present an inherently therapeutic inhalable nanocarrier for galectin-3 targeting and anti-fibrotic therapy. We envision this carrier to be doubly effective against fibrotic lung tissue when combined with an encapsulated anti-fibrotic drug, improving overall/total therapeutic efficacy and patient compliance via the reduction of off-target effects and additive therapeutic effects.

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.

Rosa roxburghii Fermentation Broths Attenuate Bleomycin-Induced Pulmonary Fibrosis by Activating the Nrf2/HO-1/NQO1 Signaling Pathway and Modulating Gut Microbiota

Pulmonary fibrosis (PF) is a chronic and progressive lung disease, and oxidative stress plays a critical role in its pathogenesis. Rosa roxburghii Tratt, known for its anti-inflammatory and antioxidant properties, has been shown to alleviate fibrosis. This study aimed to explore whether two Rosa roxburghii fermentation broths (RRFBs) (with different proportions) could attenuate bleomycin (BLM)-induced PF in mice and to elucidate the molecular mechanisms. The results revealed that RRFBs reduced structural lung damage, collagen deposition, and lung inflammation. RRFBs also suppressed fibrotic markers (Collagen I, Vimentin, and α-SMA) while enhancing epithelial marker E-cadherin expression. Additionally, RRFBs alleviated BLM-induced oxidative stress and apoptosis by activating the Nrf2/HO-1/NQO1 signaling pathway and facilitating Nrf2 nuclear translocation. Furthermore, RRFBs attenuated the BLM-induced changes in the gut microbiota; in particular, they decreased the abundance of the pathogenic bacterium Proteus and increased the abundance of the probiotics Ileibacterium and Dubosiella. Spearman correlation analysis revealed a strong association between oxidative stress inhibition and gut microbiota composition. These results indicated that RRFBs could exert lung-protective effects by inhibiting oxidative stress and alleviating intestinal disturbances.

Ferroptosis: A New Strategy for the Treatment of Fibrotic Diseases

Ferroptosis is a new type of cell death characterized by iron dependence and the excessive accumulation of lipid reactive oxygen species (lipid ROS) that has gradually become better characterized. There is sufficient evidence indicating that ferroptosis is associated with a variety of human life activities and diseases, such as tumor suppression, ischemic organ injury, and degenerative disorders. Notably, ferroptosis is also involved in the initiation and development of fibrosis in various organs, including liver fibrosis, pulmonary fibrosis, renal fibrosis, and cardiac fibrosis, which is usually irreversible and refractory. Although a large number of patients with fibrosis urgently need to be treated, the current treatment options are still limited and unsatisfactory. Organ fibrosis involves a series of complex and orderly processes, such as parenchymal cell damage, recruitment of inflammatory cells and activation of fibroblasts, which ultimately leads to the accumulation of extracellular matrix (ECM) and the formation of fibrosis. An increasing number of studies have confirmed the close association between these pathological processes and ferroptosis. This review summarizes the role and function of ferroptosis in fibrosis and proposes several potential therapeutic strategies and pathways based on ferroptosis.

Bioimpedance measurements of fibrotic and acutely injured lung tissues

In injured and diseased tissues, changes in molecular and cellular compositions, as well as tissue architecture, lead to alterations in both physiological and physical characteristics. Notably, the electrical properties of tissues, which can be characterized as bioelectrical impedance (bioimpedance), are closely linked to the health and pathological conditions of the tissues. This highlights the significant role of quantitatively characterizing these electrical properties in improving the accuracy and speed of diagnosis and prognosis. In this study, we investigate how diseases, injuries, and physical conditions can affect the electrical properties of lung tissues, using both rat and human lung tissue samples. Results showed that rat lung and trachea tissues exhibit a frequency-dependent behavior to alternating current (AC) across the frequency range of 0.1-300 kHz. The bioimpedance of the lung tissue increased with the level of aeration of the lung, which was manipulated by altering alveolar pressure (PALV: 1-15 cmH2O; bioimpedance level: 1.2-2.8 kΩ; AC frequency: 2 kHz). This increase is mainly because air is electrically nonconductive. The bioimpedance of rat lungs injured via intratracheal aspiration of hydrochloric acid (HCl; volume: 1 mL; AC frequency: 2 kHz) decreased by at least 82 % compared to that of healthy control lungs due to accumulation of fluids inside the airspace of the injured lungs. Moreover, using decellularized lung tissues, we determined the contributions of cellular components and tissue extracellular matrix (ECM) on the electrical characteristics of the lung tissues. Specifically, we observed a considerable increase in bioimpedance in fibrotic human lung tissues due to excessive ECM deposition (healthy: 70.8 Ω ± 10.2 Ω, fibrotic: 132.1 Ω ± 15.8 Ω, frequency: 2 kHz). Overall, the findings of this study can enhance our understanding of the correlation between electrical properties and pathological lung conditions, thereby improving diagnostic and prognostic capabilities and aiding in the treatment of lung diseases and injuries. STATEMENT OF SIGNIFICANCE: The bioelectrical properties of tissue are closely linked to both its physiological and physical characteristics. This underscores the importance of quantitatively characterizing these properties to improve the accuracy and speed of diagnosis and prognosis. In this study, we investigate how the bioelectrical properties of lung tissues are affected by different physical states and pathological conditions using rat and human lung tissues. As the burden of lung diseases continues to increase, our findings can contribute to improved treatment outcomes by enabling accurate and rapid assessment of lung tissue conditions.

PCR array analysis reveals a novel expression profile of ferroptosis-related genes in idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic, irreversible, and fatal disease characterized by progressive interstitial lung fibrosis. Given its insidious onset and poor outcome, there is an urgent need to elucidate the molecular mechanisms underlying IPF and identify effective therapeutic targets and diagnosis and prognosis biomarkers. Ferroptosis is an iron-dependent form of programmed cell death that occurs as lipid peroxides accumulate. Growing evidence suggests that ferroptosis is important in IPF.

METHODS

Human ferroptosis PCR array was performed on IPF and control lung tissue. The differentially expressed ferroptosis-related genes (DE-FRGs) were identified, underwent functional enrichment analyses, protein-protein interaction network construction, and potential drug target prediction. The DE-FRGs were validated and their value as diagnostic and prognostic blood biomarkers were evaluated using the Gene Expression Omnibus dataset GSE28042.

RESULTS

The array identified 13 DE-FRGs. Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that the DE-FRGs were mainly related to iron ion transport, blood microparticles, and oxidoreductase activity, and were involved in porphyrin metabolism, necroptosis, and the p53 signaling pathway in addition to ferroptosis. The 13 DE-FRGs were analyzed using the Drug-Gene Interaction Database to explore novel IPF therapeutic agents, yielding 42 potential drugs. Four DE-FRGs (BBC3, STEAP3, EPRS, SLC39A8) in the peripheral blood of IPF patients from the GSE28042 dataset demonstrated the same expression pattern as that observed in the lung tissue array. The receiver operating characteristic analysis demonstrated that the area under the curve of STEAP3 and EPRS were > 0.75. The survival analysis demonstrated that STEAP3 and EPRS were significantly different between the IPF and control groups.

CONCLUSIONS

The FRG expression profiles in IPF and control lung tissue were characterized. The findings provided valuable ideas to elucidate the role of ferroptosis in IPF and aided the identification of novel IPF therapeutic targets and biomarkers.

Genetic underpinning of idiopathic pulmonary fibrosis: the role of mucin

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterized by progressive scarring and reduced survival. The development of IPF is influenced by rare and common genetic variants, cigarette smoking, aging, and environmental exposures. Among the two dozen genetic contributors, the MUC5B promoter variant (rs35705950) is the dominant risk factor, increasing the risk of both familial and sporadic IPF and accounting for nearly 50% of the genetic predisposition to the disease.

AREAS COVERED

This review provides an expert perspective on the genetic underpinnings of IPF rather than a systematic analysis, emphasizing key insights into its genetic basis. The articles referenced in this review were identified through targeted searches in PubMed, Scopus, and Web of Science for studies published between 2000 and 2023, prioritizing influential research on the genetic factors contributing to IPF. Search terms included 'idiopathic pulmonary fibrosis,' 'genetics,' 'MUC5B,' 'telomere dysfunction,' and 'surfactant proteins.' The selection of studies was guided by the authors' expertise, focusing on the most relevant publications.

EXPERT OPINION

The identification of genetic variants not only highlights the complexity of IPF but also offers potential for earlier diagnosis and personalized treatment strategies targeting specific genetic pathways, ultimately aiming to improve patient outcomes.

A micro-lung chip with macrophages for targeted anti-fibrotic therapy

Idiopathic pulmonary fibrosis (IPF) is a lethal lung disease of unknown etiology. Macrophages are implicated in the fibrotic process, but exhibit remarkable plasticity in the activated immune environmentin vivo, presenting significant challenges as therapeutic targets. To explore the influence of macrophages on IPF and develop macrophage-targeted therapies, we engineered a micro-lung chip with a lung epithelium-interstitium tissue unit to establish a controlled immune environment containing only macrophages. We discovered that macrophages exacerbated inflammation and fibrosis by comparing microchips treated with bleomycin (BLM) in the presence and absence of macrophages. Based on the duration of BLM treatment, we established pathological models corresponding to inflammation and fibrosis stages. Transcriptome analysis revealed that activation of the PI3K-AKT signalling pathway facilitates the transition from inflammation to fibrosis. However, LY294002, a PI3K inhibitor, not only suppressed fibrosis and decreased the accumulation of M2 macrophages but also intensified the severity of inflammation. These findings suggest that macrophages play a pivotal role in the potential development at the tissue level. The micro-lung chip co-cultured with macrophages holds significant potential for exploring the pathological progression of IPF and elucidating the mechanisms of anti-fibrotic drugs.

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

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

RTN3 regulates collagen biosynthesis and profibrotic macrophage differentiation to promote pulmonary fibrosis via interacting with CRTH2

BACKGROUND

As an endoplasmic reticulum (ER) protein, Reticulum 3 (RTN3) has been reported to play a crucial role in neurodegenerative diseases, lipid metabolism, and chronic kidney disease. The involvement of RTN3 in idiopathic pulmonary fibrosis (IPF), a progressive and fatal interstitial lung disease, remains unexplored.

METHODS

In this study, we explored the role of RTN3 in pulmonary fibrosis using public datasets, IPF patient samples, and animal models. We investigated its pathogenic mechanisms in lung fibroblasts and alveolar macrophages.

RESULTS

We found decreased levels of RTN3 in IPF patients, bleomycin-induced mice, and TGFβ-treated cell lines. RTN3-null mice exhibited more severe pulmonary fibrosis phenotypes in old age or after bleomycin treatment. Collagen synthesis was significantly increased in RTN3-null mice lung tissues and lung fibroblasts. Mechanistic studies revealed that RTN3 deficiency reduced the ER-anchored CRTH2 in lung fibroblasts, which serves as an antifibrotic molecule via antagonizing collagen biosynthesis. Simultaneously, RTN3 deficiency reduced the autophagy degradation of CRTH2 which acts as an activator of profibrotic macrophage differentiation. Both effects of RTN3 and CRTH2 in lung fibroblasts and alveolar macrophages aggravated age-or bleomycin-induced pulmonary fibrosis. Additionally, we also identified a mutation of RTN3 in patients with ILD.

CONCLUSIONS

Our research demonstrated that RTN3 plays a significant role in the lung, and reduction of RTN3 levels may be a risk factor for IPF and related diseases.

The role of oxidative stress-related genes in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is an age-related interstitial lung disease of unknown cause. Oxidative stress, an imbalance between oxidants and antioxidants, is implicated in IPF pathogenesis and prognosis but needs further study. We used transcriptome sequencing data (GSE70866) and oxidative stress-related genes from GeneCards. A prognostic risk model for IPF patients was constructed using LASSO. Functional and pathway differences were analyzed between risk score groups, along with comparisons of immune cells and functions. An IPF rat model with vitamin D3 (VD3) intervention was also established. Finally, we used IL-4 to induce M2 macrophages to explore the mechanism of action of CCL2. We identified 483 DEGs and 50 oxidative stress-related DEGs (OSDEGs). Single-factor COX regression identified 34 prognostic OSDEGs, and LASSO identified an 8-gene signature for the risk model. The high-risk group had more CD8 + T cells, macrophages, APC costimulation, and cytokine-cytokine receptor activity. CCL2 was significantly correlated with macrophages in IPF. VD3 inhibited the TGF-β signaling pathway and reduced macrophage M2 infiltration in the rat model. In the IL-4 induced M2 macrophage model, we found that M2 macrophages produced more CCL2, and the production of CCL2 was significantly reduced after VD3 intervention. We established prognostic markers of eight oxidative stress-related genes. The risk score effectively predicts adverse outcomes in IPF. VD3 may alleviate IPF by reducing macrophage infiltration and inhibiting the TGF-β signaling pathway.

Identification and Analysis of Key Immune- and Inflammation-Related Genes in Idiopathic Pulmonary Fibrosis

Background

Studies suggest that immune and inflammation processes may be involved in the development of idiopathic pulmonary fibrosis (IPF); however, their roles remain unclear. This study aims to identify key genes associated with immune response and inflammation in IPF using bioinformatics.

Methods

We identified differentially expressed genes (DEGs) in the GSE93606 dataset and GSE28042 dataset, then obtained differentially expressed immune- and inflammation-related genes (DE-IFRGs) by overlapping DEGs. Two machine learning algorithms were used to further screen key genes. Genes with an area under curve (AUC) of > 0.7 in receiver operating characteristic (ROC) curves, significant expression and consistent trends across datasets were considered key genes. Based on these key genes, we carried out nomogram construction, enrichment and immune analyses, regulatory network mapping, drug prediction, and expression verification.

Results

27 DE-IFRGs were identified by intersecting 256 DEGs, 1793 immune-related genes, and 1019 inflammation-related genes. Three genes (RNASE3, S100A12, S100A8) were obtained by crossing two machine algorithms (Boruta and LASSO),which had good diagnostic performance with AUC values. These key genes were all enriched in the same pathways, such as GOCC_azurophil_granule, IL-12 signalling and production in macrophages is the pathway with the strongest role for key genes. Six distinct immune cells, including naive CD4 T cells, T cells CD4 memory resting, T cells regulatory (Tregs), Monocytes, Macrophages M2, Neutrophils were identified. Real-time quantitative polymerase chain reaction (RT-qPCR) results were consistent with the training and validation sets, and the expression of these key genes was significantly upregulated in the IPF samples.

Conclusion

This study identified three key genes (RNASE3, S100A12 and S100A8) associated with immune response and inflammation in IPF, providing valuable insights into the diagnosis and treatment of IPF.

Nano-XRF of lung fibrotic tissue reveals unexplored Ca, Zn, S and Fe metabolism: a novel approach to chronic lung diseases

Synchrotron-radiation nano-X-Ray Fluorescence (XRF) is a cutting-edge technique offering high-resolution insights into the elemental composition of biological tissues, shedding light on metabolic processes and element localization within cellular structures. In the context of Idiopathic Pulmonary Fibrosis (IPF), a debilitating lung condition associated with respiratory complications and reduced life expectancy, nano-XRF presents a promising avenue for understanding the disease's intricate pathology. Our developed workflow enables the assessment of elemental composition in both human and rodent fibrotic tissues, providing insights on the interplay between cellular compartments in chronic lung diseases. Our findings demonstrate trace element accumulations associated with anthracosis, a feature observed in IPF. Notably, Zn and Ca clusters approximately 750 nm in size were identified exclusively in IPF samples. While their specific role remains unclear, their presence may be associated with disease-specific processes. Additionally, we observed Fe and S signal colocalization in 650-nm structures within some IPF cells. Fe-S complexes in mitochondria are known to be associated with increased ROS production, suggesting a potential connection to the disease pathology. In contrast, a bleomycin-induced fibrosis rodent model exhibits a different elemental phenotype with low Fe and increased S, Zn, and Ca. Overall, our workflow highlights the effectiveness of synchrotron-based nano-XRF mapping in analyzing the spatial distribution of trace elements within diseased tissue, offering valuable insights into the elemental aspects of IPF and related chronic lung diseases.

Idiopathic Pulmonary Fibrosis: In Silico Therapeutic Potential of Doxycycline, Pirfenidone, and Nintedanib, and the Role of Next-Generation Phenomics in Drug Discovery

Innovation in drug discovery for human diseases stands to benefit from systems science and next-generation phenomics approaches. An example is idiopathic pulmonary fibrosis (IPF) that is a chronic pulmonary disorder leading to respiratory failure and for which preventive and therapeutic medicines are sorely needed. Matrix metalloproteinases (MMPs), particularly MMP1 and MMP7, have been associated with IPF pathogenesis and are thus relevant to IPF drug discovery. This study evaluates the comparative therapeutic potentials of doxycycline, pirfenidone, and nintedanib in relation to MMP1 and MMP7 using molecular docking, molecular dynamics simulations, and a next-generation phenomics approach. Adsorption, distribution, metabolism, excretion, and toxicity analysis revealed that doxycycline and nintedanib adhered to Lipinski's rule of five, while pirfenidone exhibited no violations. The toxicity analysis revealed favorable safety profiles, with lethal dose 50 values of doxycycline, pirfenidone, and nintedanib being 2240kg, 580, and 500 mg/kg, respectively. Homology modeling validated the accuracy of the structures of the target proteins, that is, MMP1 and MMP7. The Protein Contacts Atlas tool, a next-generation phenomics platform that broadens the scope of phenomics research, was employed to visualize protein contacts at atomic levels, revealing interaction surfaces in MMP1 and MMP7. Docking studies revealed that nintedanib exhibited superior binding affinities with the candidate proteins (-6.9 kcal/mol for MMP1 and -7.9 kcal/mol for MMP7) compared with doxycycline and pirfenidone. Molecular dynamics simulations further demonstrated the stability of protein-ligand complexes. These findings highlight the notable potential of nintedanib in relation to future IPF therapeutics innovation. By integrating in silico and a next-generation phenomics approach, this study opens up new avenues for drug discovery and development for IPF and possibly, for precision/personalized medicines that consider the molecular signatures of therapeutic candidates for each patient.

Single Cell RNA-Seq Identifies Cell Subpopulations Contributing to Idiopathic Pulmonary Fibrosis in Humans

The cell populations, particularly subpopulations, involved in the onset and progression of idiopathic pulmonary fibrosis (IPF) remain incompletely understood. This study employed single-cell RNA-seq to identify cell populations and subpopulations with significantly altered proportions in the lungs of patients with IPF. In IPF lungs, endothelial cell proportions were significantly increased, while alveolar epithelial cell proportions were markedly decreased. Among the three identified fibroblast subpopulations, the proportion of myofibroblasts was significantly increased, while the proportions of the other two fibroblast subtypes were reduced. Similarly, within the three macrophage subpopulations, the macrophage_SPP1 subpopulation, localised to fibroblastic foci, showed a significant increase in proportion, while the alveolar macrophage subpopulation was significantly reduced. Trajectory analysis revealed that fibroblasts in IPF lungs could differentiate into myofibroblasts, and alveolar macrophages could transition into the macrophage_SPP1 subpopulation. Among T-cell subpopulations, only the CD4 T_FOXP3 subpopulation exhibited a significant change, whereas all four B-cell subpopulations showed significant proportional shifts. These findings provide a comprehensive view of the cellular alterations contributing to IPF pathogenesis. Extensive interactions among various cell populations and subpopulations were identified. The proportions of various cell populations and subpopulations in IPF lungs, including endothelial cells, fibroblasts, macrophages and B cells, were significantly altered. Further in-depth investigation into the roles of cell subpopulations with significantly altered proportions in the onset and progression of IPF will provide valuable insights into the pathological mechanisms underlying the disease. This understanding could facilitate the development of novel therapeutic strategies and medications for IPF treatment.

Cell therapy: A beacon of hope in the battle against pulmonary fibrosis

Pulmonary fibrosis (PF) is a chronic and progressive interstitial lung disease characterized by abnormal activation of myofibroblasts and pathological remodeling of the extracellular matrix, with a poor prognosis and limited treatment options. Lung transplantation is currently the only approach that can extend the life expectancy of patients; however, its applicability is severely restricted due to donor shortages and patient-specific limitations. Therefore, the search for novel therapeutic strategies is imperative. In recent years, stem cells have shown great promise in the field of regenerative medicine due to their self-renewal capacity and multidirectional differentiation potential, and a growing body of literature supports the efficacy of stem cell therapy in PF treatment. This paper systematically summarizes the research progress of various stem cell types in the treatment of PF. Furthermore, it discusses the primary methods and clinical outcomes of stem cell therapy in PF, based on both preclinical and clinical data. Finally, the current challenges and key factors to consider in stem cell therapy for PF are objectively analyzed, and future directions for improving this therapy are proposed, providing new insights and references for the clinical treatment of PF patients.

ShaShen-MaiDong decoction attenuates bleomycin-induced pulmonary fibrosis by inhibiting TGF-β/smad3, AKT/MAPK, and YAP/TAZ pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Pulmonary fibrosis (PF) is progressive and terminal lung disease, which is also the most common sequelae of Corona Virus Disease (2019) (COVID-19) survivors. Unfortunately, there is currently no cure for PF. ShaShen-MaiDong decoction (SMT), a traditional Chinese medicine, has been employed in treating various lung diseases, which may offer potential therapeutic benefits for PF.

AIM OF THE STUDY

To investigate the antifibrotic efficacy of SMT and its major active ingredients as well as the underlying mechanisms for treating PF.

MATERIALS AND METHODS

Fist, we build the UPLC-MS based qualitative and quantitative profiling for the quality control of SMT. Then, the antifibrotic efficacy of SMT was investigated in bleomycin (BLM)-induced PF mice model. Network pharmacology was used to predict the mechanism and active components of SMT for the treatment of PF, which was further verified in vitro and in vivo.

RESULTS

SMT improved the weight loss and attenuated hydroxyproline, inflammatory cytokines, and collagen deposition in BLM-induced PF mice model in a dose-dependent manner. Mechanistically, as predicted by network pharmacology analysis, SMT and its active compounds (kaempferol, quercetin, and isorhamnetin) regulated the mitogen-activated protein kinase (MAPK) signaling pathways, TGF-β/Smad signaling pathway, and YAP/TAZ signaling pathway, which was further verified in the PF mice and TGF-β-induced A549 cell model. Moreover, SMT balanced the proportions of increased CD4+ and decreased CD8+ T cells in the peripheral blood of PF mice model.

CONCLUSIONS

Considering the high mortality and complex pathogenesis of fibrotic diseases, our results provide novel evidence that SMT would be beneficial for pulmonary fibrosis therapy by modulating MAPK, TGF-β/Smad, and YAP/TAZ signaling pathways at same time.

MSC-derived exosome ameliorates pulmonary fibrosis by modulating NOD 1/NLRP3-mediated epithelial-mesenchymal transition and inflammation

Background

Pulmonary fibrosis (PF) is an irreversible and usually fatal lung disease. In recent years, the therapeutic role of exosomes derived from mesenchymal stem cells (MSC-exos) in anti-fibrotic treatment has received much attention. In this study, we aimed to determine the anti-fibrotic properties and related molecular mechanisms of MSC-exos in Bleomycin(BLM)-induced PF.

Methods

We used BLM-induced mice model of PF and in vitro model. MSC-exos were isolated from BMSCs cells using Exo Quick-TC kit and identified using conventional methods. Using cell counting kit-8 (CCK-8) to detect cell viability. Classic molecular biology approaches such as RT-qPCR, Western blot, immunofluorescence, and ELISA were used to examine molecular pathways. Histopathological examination was performed using HE and Masson staining.

Results

MSC-exos alleviated inflammation, inhibited epithelial-mesenchymal transition (EMT), and ameliorated PF. Further studies showed that MSC-exos regulated NOD1/NF-kB signaling pathway to suppress the activation of NLRP3 inflammasomes both in vivo and in vitro. Additionally, overexpression of NLRP3 significantly reversed the anti-fibrotic effects of MSC-exos in BLM-induced lung epithelial cells.

Conclusion

MSC-derived exosome ameliorates pulmonary fibrosis by modulating NOD 1/NLRP3-mediated epithelial-mesenchymal transition and inflammation.

Inhalable Carbonyl Sulfide Donor-Hybridized Selective Phosphodiesterase 10A Inhibitor for Treating Idiopathic Pulmonary Fibrosis by Inhibiting Tumor Growth Factor-β Signaling and Activating the cAMP/Protein Kinase A/cAMP Response Element-Binding Protein (CREB)/p53 Axis

Idiopathic pulmonary fibrosis (IPF) is a debilitating, incurable, and life-threatening disease that lacks effective therapy. The overexpression of phosphodiesterase 10A (PDE10A) plays a vital role in pulmonary fibrosis (PF). However, the impact of selective PDE10A inhibitors on the tumor growth factor-β (TGF-β)/small mother against decapentaplegic (Smad) signaling pathway remains unclear. Herein, we have exploited a novel carbonyl sulfide (COS)/hydrogen sulfide (H2S)-donor hybrid PDE10A inhibitor called COS-2080 with a well-defined mechanism of H2S-releasing action. It exhibited highly potent inhibitory activity against PDE10A and excellent PDE subfamily selectivity. Moreover, COS-2080 demonstrated significant antifibrotic effects by inhibiting cell proliferation and mitigating fibroblast-to-myofibroblast transition (FMT). A dry powder inhalation formulation called COS-2080-DPI has been developed using the ultrasonic spray freeze drying (USFD) technique, demonstrating significant antifibrotic efficacy in mice with bleomycin-induced PF at a dosage approximately 600 times lower than pirfenidone. This remarkable antifibrotic efficacy of COS-2080 on TGF-β1-induced FMT could be primarily attributed to its inhibition of the Smad2/Smad3 phosphorylation. Moreover, COS-2080 effectively attenuated fibrosis in MRC-5 cells by activating the cAMP/protein kinase A (PKA)/CREB pathway and potentially increasing levels of p53 protein. Our findings suggest that effective inhibition of PDE10A potentially confers a protective effect on FMT in PF by impeding TGF-β signaling and activating the cAMP/PKA/CREB/p53 axis.

Ultrasonic Microfluidic Method Used for siHSP47 Loaded in Human Embryonic Kidney Cell-Derived Exosomes for Inhibiting TGF-β1 Induced Fibroblast Differentiation and Migration

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and devastating lung disorder. In response to transforming growth factor-β (TGF-β), normal lung cells proliferate and differentiate into myofibroblasts, which are instrumental in promoting disease progression. Small interfering RNA (siRNA) targeting heat shock protein 47 (HSP47) has been demonstrated to alleviate IPF by blocking collagen synthesis and secretion. Exosomes (EXOs) have been investigated for drug delivery due to their superior carrier properties. However, their loading efficiency has been a limiting factor in widely application as drug carriers. In this study, an ultrasonic microfluidic method was employed to enhance the loading efficiency of siHSP47 into EXOs, achieving 31.1% efficiency rate. EXOs were isolated from human embryonic kidney cells (293F) and loaded with siHSP47 (EXO-siHSP47). The findings indicated that EXO-siHSP47 penetrated the collagen barrier and effectively silenced HSP47 expression in activated fibroblasts in vitro. Western blotting and immunofluorescence analyses confirmed that EXO-siHSP47 significantly reduced the secretion and deposition of extracellular matrix (ECM) proteins. Wound healing and Transwell migration assays demonstrated that EXO-siHSP47 inhibited fibroblast differentiation and migration. In conclusion, 293F-derived EXOs loaded with siHSP47 present a promising therapeutic strategy for IPF.

Pathology of idiopathic pulmonary fibrosis with particular focus on vascular endothelium and epithelial injury and their therapeutic potential

Idiopathic pulmonary fibrosis (IPF) remains a challenging disease with no drugs available to change the trajectory. It is a condition associated with excessive and highly progressive scarring of the lungs with remodelling and extracellular matrix deposition. It is a highly "destructive" disease of the lungs. The diagnosis of IPF is challenging due to continuous evolution of the disease, which also makes early interventions very difficult. The role of vascular endothelial cells has not been explored in IPF in great detail. We do not know much about their contribution to arterial or vascular remodelling, extracellular matrix changes and contribution to pulmonary hypertension and lung fibrosis in general. Endothelial to mesenchymal transition appears to be central to such changes in IPF. Similarly, for epithelial changes, the process of epithelial to mesenchymal transition seem to be the key both for airway epithelial cells and type-2 pneumocytes. We focus here on endothelial and epithelial cell changes and its contributions to IPF. In this review we revisit the pathology of IPF, mechanistic signalling pathways, clinical definition, update on diagnosis and new advances made in treatment of this disease. We discuss ongoing clinical trials with mode of action. A multidisciplinary collaborative approach is needed to understand this treacherous disease for new therapeutic targets.

The molecular and metabolic landscape of ferroptosis in respiratory diseases: Pharmacological aspects

Ferroptosis is a form of cell death that occurs when there is an excess of reactive oxygen species (ROS), lipid peroxidation, and iron accumulation. The precise regulation of metabolic pathways, including iron, lipid, and amino acid metabolism, is crucial for cell survival. This type of cell death, which is associated with oxidative stress, is controlled by a complex network of signaling molecules and pathways. It is also implicated in various respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), acute lung injury (ALI), lung cancer, pulmonary fibrosis (PF), and the coronavirus disease 2019 (COVID-19). To combat drug resistance, it is important to identify appropriate biological markers and treatment targets, as well as intervene in respiratory disorders to either induce or prevent ferroptosis. The focus is on the role of ferroptosis in the development of respiratory diseases and the potential of targeting ferroptosis for prevention and treatment. The review also explores the interaction between immune cell ferroptosis and inflammatory mediators in respiratory diseases, aiming to provide more effective strategies for managing cellular ferroptosis and respiratory disorders.

Ginsenoside Rb1 Relieves Cellular Senescence and Pulmonary Fibrosis by Promoting NRF2/QKI/SMAD7 Axis

Cellular senescence is an adverse factor in the development of pulmonary fibrosis (PF). Ginsenoside Rb1 has been found to inhibit both cellular senescence and PF. This study aimed to elucidate the molecular mechanisms by which ginsenoside Rb1 regulates cellular senescence and PF. A PF mouse model was established by Bleomycin (BLM) administration, and a cell model of senescence was constructed using MRC-5 cells treated with Adriamycin RD (ARD) administration. Hematoxylin and Eosin (HE) staining and Masson staining were employed to evaluate cellular structure and collagen fiber content. RT-qPCR and western blotting were used to detect mRNA and protein expression of the target genes. Enzyme-linked Immunosorbent Assay (ELISA) was applied to measure the protein concentration of IL-1[Formula: see text] and IL-18. SA-[Formula: see text]-gal staining was used to evaluate cellular senescence. Our results show that ginsenoside Rb1 effectively suppressed BLM-induced PF in mice. ARD administration to induce cellular senescence reduced NRF2, QKI, and SMAD7 expression in MRC-5 cells. By inducing NRF2 overexpression, ARD-induced cellular senescence and fibrosis in MRC-5 cells were relieved. Notably, NRF2 knockdown abolished the mitigating effects of ginsenoside Rb1 on ARD-induced cellular senescence and fibrosis in MRC-5 cells. Mechanistically, NRF2 increased SMAD7 mRNA stability through the transcriptional regulation of QKI. As expected, ginsenoside Rb1 alleviated ARD-induced senescence and fibrosis in MRC-5 cells by activating the NRF2/QKI/SMAD7 axis. Therefore, it was found that ginsenoside Rb1 mitigates cellular senescence and fibrosis during PF progression by activating the NRF2/QKI/SMAD7 axis. This study provides a potential therapeutic strategy for the treatment of PF and elucidates its mechanism of action.

Nintedanib attenuates NLRP3 inflammasome-driven liver fibrosis by targeting Src signaling

Liver injury induces an inflammatory response that activates hepatic stellate cells, which is the initial factor of liver fibrosis. Nintedanib, a multi-targeted tyrosine kinase inhibitor targeting the Src signalling pathway, has been approved for the treatment of idiopathic pulmonary fibrosis. However, it is still not known whether nintedanib ameliorates liver fibrosis by inhibiting inflammasome activation. Here, a carbon tetrachloride (CCl4)-induced liver fibrosis model was used to assess the anti-fibrotic efficacy of nintedanib in vivo. Lipopolysaccharide and ATP were used to activate nucleotide oligomerisation domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasomes in LX-2 cells, and the efficacy of nintedanib on NLRP3 inflammasome activation was evaluated. Moreover, we used Src-overexpressing and Src-downregulating lentiviruses to transfect LX-2 cells to explore the targets of nintedanib. Nintedanib attenuated inflammation and extracellular matrix accumulation in CCl4-induced fibrotic livers and reduced the expression of NLRP3, fibrotic makers, and the phosphorylation of Src, epidermal growth factor receptor (EGFR), AKT, ERK1/2 in LX-2 cells. Furthermore, nintedanib thwarted NLRP3 inflammasome activation by suppressing the phosphorylation of Src and its downstream signalling pathway and reducing reactive oxygen species production. Our study indicates that nintedanib effectively suppresses NLRP3 inflammasome activation and has the potential for the treatment of liver fibrosis.

Investigates the Role of PANoptosis in Idiopathic Pulmonary Fibrosis and Potential Therapeutic Targets

Purpose

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease. PANoptosis, a unique inflammatory programmed cell death, it manifests as the simultaneous activation of signaling markers for pyroptosis, apoptosis, and necroptosis. However, research on the role of PANoptosis in the development of IPF is currently limited. This study was aimed to explore the role of PANoptosis in IPF.

Methods

In this study, we first identified PANDEGs using the GEO database. Exploring potential biological functions and immune cell infiltration abundance through GO/KEGG enrichment analysis and Immune infiltration analysis. Through machine learning and experimental validation, we identified four diagnostic genes and four prognostic genes associated with PANoptosis, leading to the development of a diagnostic and prognostic model for IPF. Our single-cell analysis further explored the role of these PANoptosis prognostic genes. Additionally, the L1000FWD application was used to identify small molecule drugs, based on the four PANoptosis prognostic genes, and confirmed their efficacy through molecular docking.

Results

104 PANoptosis differentially expressed genes were identified from IPF and normal tissues. Enrichment analysis indicated that these genes were associated with immune-inflammatory response pathway. We developed a diagnostic and prognostic models based on PANoptosis related genes. The diagnostic model included AKT1, PDCD4, PSMA2, and PPP3CB. Conversely, the prognostic model included TNFRSF12A, DAPK2, UACA, and DSP. External dataset validation and qPCR showed the reliability of most of the conclusions. Additionally, potential therapeutic drugs, including Metergoline, Candesartan, and Selumetinib, were identified based on four prognostic genes. Molecular docking shows that these drugs have good binding ability with their targets.

Conclusion

Importantly, our findings provide scientific evidence for the diagnosis and prognostic biomarkers of IPF patients, as well as small molecule therapeutic drugs.

Rationale for phosphodiesterase-4 inhibition as a treatment strategy for interstitial lung diseases associated with rheumatic diseases

Interstitial lung disease (ILD) associated with rheumatoid arthritis or with connective tissue diseases such as systemic sclerosis can be collectively named systemic autoimmune rheumatic disease-associated ILDs (SARD-ILDs) or rheumatic musculoskeletal disorder-associated ILDs. SARD-ILDs result in substantial morbidity and mortality, and there is a high medical need for effective therapies that target both fibrotic and inflammatory pathways in SARD-ILD. Phosphodiesterase 4 (PDE4) hydrolyses cyclic AMP, which regulates multiple pathways involved in inflammatory processes. PDE4 is overexpressed in peripheral blood monocytes from patients with inflammatory diseases. However, clinical data on pan-PDE4 inhibition in fibrotic conditions are lacking. The PDE4B subtype is highly expressed in the brain, lungs, heart, skeletal muscle and immune cells. As such, inhibition of PDE4B may be a novel approach for fibrosing ILDs such as idiopathic pulmonary fibrosis (IPF) and SARD-ILD. Preclinical data for PDE4B inhibition have provided initial evidence of both anti-inflammatory and antifibrotic activity, with reduced potential for gastrointestinal toxicity compared with pan-PDE4 inhibitors. In a proof-of-concept phase II trial in patients with IPF, nerandomilast (BI 1015550), the only PDE4B inhibitor currently in clinical development, prevented a decline in lung function over 12 weeks compared with placebo. The potential clinical benefit of PDE4B inhibition is now being investigated in the phase III setting, with two trials evaluating nerandomilast in patients with IPF (FIBRONEER-IPF) or with progressive pulmonary fibrosis other than IPF (FIBRONEER-ILD). Here, we review the preclinical and clinical data that provide rationale for PDE4B inhibition as a treatment strategy in patients with SARD-ILD.

Multiscale drug screening for cardiac fibrosis identifies MD2 as a therapeutic target

Cardiac fibrosis impairs cardiac function, but no effective clinical therapies exist. To address this unmet need, we employed a high-throughput screening for antifibrotic compounds using human induced pluripotent stem cell (iPSC)-derived cardiac fibroblasts (CFs). Counter-screening of the initial candidates using iPSC-derived cardiomyocytes and iPSC-derived endothelial cells excluded hits with cardiotoxicity. This screening process identified artesunate as the lead compound. Following profibrotic stimuli, artesunate inhibited proliferation, migration, and contraction in human primary CFs, reduced collagen deposition, and improved contractile function in 3D-engineered heart tissues. Artesunate also attenuated cardiac fibrosis and improved cardiac function in heart failure mouse models. Mechanistically, artesunate targeted myeloid differentiation factor 2 (MD2) and inhibited MD2/Toll-like receptor 4 (TLR4) signaling pathway, alleviating fibrotic gene expression in CFs. Our study leverages multiscale drug screening that integrates a human iPSC platform, tissue engineering, animal models, in silico simulations, and multiomics to identify MD2 as a therapeutic target for cardiac fibrosis.

RNA-seq analysis and in vivo experiments identified the protective effect of kaempferol on idiopathic pulmonary fibrosis by regulating the PPARG/TNC signaling pathway to reduce ECM deposition

Idiopathic pulmonary fibrosis (IPF) is a chronic age-related lung disease with a high mortality rate. Kaempferol (KMP), an active ingredient in common plants and foods with anti-inflammatory, antioxidant and immunomodulatory properties, has been shown to be effective against fibrotic diseases. However, the molecular mechanisms underlying the treatment of IPF with KMP remain unclear. Therefore, IPF mice were established by intratracheal instillation of bleomycin (BLM) to explore the efficacy and underlying mechanism of KMP in the treatment of IPF. We found that KMP improved the body weight changes of BLM-induced IPF mice, alleviated inflammatory infiltration and collagen deposition, and decreased the expression levels of hydroxyproline, α-SMA, Col3a1, Mmp2, Timp1, Vim, Fn, TNF-α, TGF-β1, IL-6 and IL-8, while up-regulating the expression E-cadherin in lung tissues. The transcriptomic results showed that KMP may exert therapeutic effects against IPF by regulating the PPARG/TNC signaling pathway to reduce extracellular matrix (ECM) deposition. Interestingly, ROC curve analysis suggested that TNC and PPARG had good diagnostic performance for IPF, and TF prediction revealed that PPARG is an important upstream gene regulating TNC, and the IF experiment confirmed the co-localization of TNC and PPARG. Molecular docking showed that KMP bound well to PPARG and TNC, and IF results revealed that KMP significantly reduced the interaction between PPARG and TNC. Furthermore, RT-PCR, WB, IHC and IF experiments confirmed that KMP elevated the expression of PPARG and inhibited the expression of TNC, thus inhibiting the ECM-receptor interaction pathway and ultimately serving as a therapeutic treatment for IPF mice. These findings revealed that KMP reduced inflammatory infiltration and collagen deposition in the lungs of IPF mice and that the PPARG/TNC signaling pathway may be an important mechanism for the treatment of IPF with KMP, which provides a new perspective for the development of therapeutic approaches for IPF.

ANRIL upregulates TGFBR1 to promote idiopathic pulmonary fibrosis in TGF-β1-treated lung fibroblasts via sequestering let-7d-5p

Idiopathic pulmonary fibrosis (IPF) is a progressive and life-threatening respiratory disease characterized by worsening lung function due to excessive scarring. The objective of this study was to investigate the role of the long non-coding RNA ANRIL (antisense non-coding RNA in the INK4 locus) in the development of IPF. Our research revealed a significant increase in ANRIL expression in pulmonary fibrosis, consistent with prior studies indicating elevated ANRIL levels in fibrotic tissues. In vitro experiments demonstrated that elevated ANRIL expression promoted fibroblast activation, as evidenced by the upregulation of fibrosis-related markers. Mechanistically, we found that ANRIL interacts with let-7d-5p, a microRNA involved in gene regulation, acting as a sponge for let-7d-5p. Functional experiments confirmed a potential influence of let-7d-5p on fibroblast activation through direct interaction with ANRIL. Furthermore, our investigation identified TGFBR1 as a potential mediator of ANRIL's fibrogenic effects. Silence of TGFBR1 mitigated the fibrotic phenotype induced by ANRIL overexpression. Collectively, these results suggest that ANRIL promotes fibroblast activation and fibrosis development, possibly through the let-7d-5p/TGFBR1 axis, indicating that ANRIL could be a potential therapeutic target for pulmonary fibrosis.