Search Results (148)

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease characterized by aberrant fibroblast activation, lysosomal dysfunction, and cellular senescence. Transcriptomic analyses have identified ependymin-related 1 (EPDR1) as a fibroblast-enriched gene in IPF, but its biological function remains unclear. EPDR1 expression was assessed in lung fibroblasts, lung tissues, bronchoalveolar lavage fluid (BALF), and serum from IPF patients and controls using qPCR, Western blotting, ELISA, and immunohistochemistry. Lysosomal function, autophagic flux, and senescence markers were analyzed in primary fibroblasts following siRNA-mediated EPDR1 knockdown. EPDR1 was significantly upregulated in IPF-derived fibroblasts and localized to fibrotic regions enriched with α-SMA⁺, COL1A1⁺, and FN1⁺ myofibroblasts of IPF-derived lung tissues. EPDR1 levels were markedly elevated in the BALF and serum of IPF patients and correlated with increased mortality. IPF fibroblasts exhibited reduced lysosomal acidification and impaired autophagic flux, indicated by p62 and LC3B accumulation. EPDR1 knockdown restored lysosomal function; enhanced autophagic degradation; and reduced senescence markers, including p21, p16, and SA-β-gal activity. EPDR1 drives lysosomal dysfunction and fibroblast senescence in IPF. Its elevated expression in lung tissue and biological fluids, together with its association with prognosis, highlights EPDR1 as a potential biomarker and therapeutic target in IPF. Full article

Background and Objectives: Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease with few effective treatments. In its pathogenesis, damage-associated molecular patterns are released and recognized by Toll-like receptors (TLRs); all TLRs except TLR3 transduce signals through MyD88. Research has shown that autophagy participates in the progression of pulmonary fibrosis, and MyD88 is closely associated with autophagy. However, whether targeting MyD88 can affect fibrosis progression by regulating autophagy during lung fibrosis remains unclear. Materials and Methods: TJ-M2010-5 (TJ-5) is a small molecular derivative of aminothiazole that inhibits MyD88 homodimerization. A bleomycin-induced pulmonary fibrosis model in mice was established, and a human lung fibroblast cell line MRC-5 was cultured, and the mechanism of fibrosis induced by TGF-β1 was studied. TJ-5 and the autophagy inhibitor 3-MA were used to intervene. Results: Our study indicated that TJ-5 suppressed fibrosis foci formation and collagen deposition in fibrotic lungs, effectively increased the survival rate of bleomycin-stimulated mice from 40.0% to 80.0%, and repressed lung fibroblast activation in vitro. Subsequently, TJ-5 could trigger autophagy, as indicated by increased autophagosomes, LC3B-II and Beclin-1 promotion, and p62 degradation. Moreover, inhibition of TJ-5-induced autophagy by 3-MA reversed the anti-fibrosis effect of TJ-5. Furthermore, the autophagy-related pathways PI3K/AKT/mTOR and MAPK/mTOR were inhibited under TJ-5 intervention. Conclusions: Our findings demonstrated that the mechanism of TJ-5 in alleviating lung fibrosis was through triggering MyD88-related autophagy, and TJ-5 may be therapeutically useful for the clinical treatment of IPF. Full article

Background/Objectives: Idiopathic pulmonary fibrosis (IPF) is a progressive disease characterized by lung scarring, impaired function, and high mortality. Effective therapies to reverse fibrosis are lacking. This study aims to uncover the molecular mechanisms of IPF, explore diagnostic biomarkers, and identify therapeutic targets. Methods: Multi-omics data were integrated to identify biomarkers with causal associations to IPF using Mendelian randomization and transcriptomic analysis. Machine learning was employed to construct a diagnostic model, and single-cell transcriptomic analysis determined gene expression patterns in fibrotic lung tissue. Results: Seven core genes (GREM1, UGT1A6, CDH2, TDO2, HS3ST1, ADGRF5, and MPO) were identified, showing strong diagnostic potential (AUC = 0.987, 95% CI: 0.972–0.987). These genes exhibited distinct distribution patterns in fibroblasts, endothelial cells, epithelial cells, macrophages, and dendritic cells. Conclusions: This study highlights key genes driving IPF, involved in pathways related to metabolism, immunity, and inflammation. However, their utility as fluid-based biomarkers remains unproven and requires protein-level validation in prospective cohorts. By integrating genomic, immunological, and cellular insights, it provides a framework for targeted therapies and advances mechanism-based precision medicine for IPF. Full article

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease characterized by the accumulation of fibrotic tissue in the lungs, leading to impaired gas exchange and respiratory failure, with a poor prognosis and limited treatment options. Oleuropein, a compound extracted from olive leaves, demonstrates a range of pharmacological activities, including benefits for non-alcoholic fatty liver disease and cardiac fibrosis. This study investigates the therapeutic potential of oleuropein for IPF and its underlying mechanisms. We first established a bleomycin-induced mouse model of pulmonary fibrosis and evaluated the in vivo efficacy of oleuropein. Our findings demonstrated that oleuropein significantly alleviated lung fibrosis and improved pulmonary function. Through in vitro experiments, we found that oleuropein inhibited TGF-β1-induced fibroblast migration, activation, autophagy, and apoptotic resistance, and mechanistically, oleuropein could regulate the TGF-β1/Smad and TGF-β1/mTOR signaling pathways in fibroblasts. Additionally, molecular docking analysis indicated that FAP-α is a potential target of oleuropein, displaying strong binding affinity. The effects of oleuropein on fibroblasts were markedly disrupted in FAP-α knockout cells. In conclusion, oleuropein exerts its beneficial effects by targeting FAP-α and inhibiting TGF-β1-related signaling pathways, improving the pathological characteristics of pulmonary fibrosis in mouse models, and demonstrating promising application prospects for the treatment of IPF. Full article

Idiopathic pulmonary fibrosis (IPF) is characterized by excessive extracellular matrix (ECM) deposition driven by aberrant fibroblast-to-myofibroblast transition (FMT). However, the upstream regulators and downstream effectors of this process remain incompletely understood. Here, we identify acyl-CoA synthetase long-chain family member 4 (ACSL4), a lipid metabolic enzyme, as a critical mediator linking complement component 5a (C5a)/C5a receptor 1 (C5aR1) signaling to FMT via calcium signaling. In bleomycin (BLM)-induced pulmonary fibrosis of C57BL/6JGpt mice, and in C5a-stimulated primary lung fibroblasts, the expression of ACSL4 was markedly upregulated. Pharmacological inhibition of ACSL4 (PRGL493) or C5aR1 (PMX53) attenuated the deposition of ECM and suppressed the expression of fibrotic markers in vivo and in vitro. Mechanistically, the activation of C5a/C5aR1 signaling increased intracellular calcium levels and promoted the expression of ACSL4, while inhibition of calcium signaling (FK506) reversed the upregulation of ACSL4 and FMT-related changes, including the expression of α-smooth muscle actin (αSMA) and the migration of fibroblasts. Notably, inhibition of ACSL4 did not affect the proliferation of fibroblasts, suggesting its specific role in phenotypic transition. These findings demonstrate that ACSL4 functions downstream of C5a/C5aR1-induced calcium signaling to promote FMT and the progression of pulmonary fibrosis. Targeting ACSL4 may therefore offer a novel therapeutic strategy for IPF. Full article

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing lung disease characterized by chronic inflammation, vascular remodeling, and immune dysregulation. COVID-19, caused by SARS-CoV-2, shares several systemic immunohematologic disturbances with IPF, including cytokine storms, endothelial injury, and prothrombotic states. Unlike general comparisons of viral infections and chronic lung disease, this review offers a focused analysis of the shared hematologic and immunologic mechanisms between COVID-19 and IPF. Our aim is to better understand how SARS-CoV-2 infection may worsen disease progression in IPF and identify converging pathophysiological pathways that may inform clinical management. We conducted a narrative synthesis of the peer-reviewed literature from PubMed, Scopus, and Web of Science, focusing on clinical, experimental, and pathological studies addressing immune and coagulation abnormalities in both COVID-19 and IPF. Both diseases exhibit significant overlap in inflammatory and fibrotic signaling, particularly via the TGF-β, IL-6, and TNF-α pathways. COVID-19 amplifies coagulation disturbances and endothelial dysfunction already present in IPF, promoting microvascular thrombosis and acute exacerbations. Myeloid cell overactivation, impaired lymphocyte responses, and fibroblast proliferation are central to this shared pathophysiology. These synergistic mechanisms may accelerate fibrosis and increase mortality risk in IPF patients infected with SARS-CoV-2. This review proposes an integrative framework for understanding the hematologic and immunologic convergence of COVID-19 and IPF. Such insights are essential for refining therapeutic targets, improving prognostic stratification, and guiding early interventions in this high-risk population. Full article

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disorder characterized by excessive scarring of lung tissue, predominantly affecting middle-aged and elderly populations. Oxidative stress plays a pivotal role in the pathogenesis of pulmonary fibrosis, disrupting redox homeostasis and driving fibrotic progression. Glutathione reductase (GSR), a key antioxidant enzyme, is essential for maintaining cellular glutathione (GSH) levels and mitigating oxidative damage. However, the specific involvement of GSR in IPF remains poorly understood. This study found that GSR levels were downregulated in IPF patients and mice treated with bleomycin (BLM). GSR knockdown enhanced epithelial-to-mesenchymal transition (EMT) in A549 cells and promoted the activation of MRC5 cells. Additionally, GSR depletion promoted cellular migration and senescence in both A549 and MRC5 cells. Mechanistically, silencing GSR in A549 and MRC5 cells led to a marked reduction in intracellular GSH levels, resulting in elevated reactive oxygen species (ROS) accumulation, thereby promoting the activation of the TGF-β/Smad2 signaling pathway. In conclusion, our findings demonstrate that GSR deficiency aggravates pulmonary fibrosis by impairing antioxidant defense mechanisms, promoting EMT, and activating fibroblasts through the TGF-β/Smad2 signaling. These findings suggest that GSR may be essential in reducing the fibrotic progression of IPF. Full article

Background and Objectives: Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal interstitial lung disease with limited therapeutic options. Current therapies (pirfenidone, nintedanib) exhibit modest efficacy and significant side effects, underscoring the need for novel strategies targeting early pathogenic drivers. Saroglitazar (SGZ), a dual PPARα/γ agonist with anti-inflammatory properties approved for diabetic dyslipidemia, has not been explored for IPF. We aimed to investigate SGZ’s therapeutic potential in pulmonary fibrosis and elucidate its mechanisms of action. Materials and Methods: Using a bleomycin (BLM)-induced murine pulmonary fibrosis model, we administered SGZ therapeutically. A histopathological assessment (H&E, Masson’s trichrome, collagen I immunofluorescence), Western blotting, and qRT-PCR analyzed the fibrosis progression and inflammatory markers. Flow cytometry evaluated the macrophage polarization. In vitro studies used RAW264.7 macrophages stimulated with BLM/LPS and MRC-5 fibroblast co-cultures. The NF-κB/NLRP3 pathway activation was assessed through protein and gene expression. Results: SGZ significantly attenuated BLM-induced histopathological hallmarks, including alveolar wall thickening, collagen deposition, and inflammatory infiltration. Fibrotic markers (OPN, α-SMA) and pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) were downregulated in the SGZ-treated mice. Mechanistically, SGZ suppressed the M1 macrophage polarization (reduced CD86⁺ populations) and inhibited the NF-κB/NLRP3 pathway activation in the alveolar macrophages. In the RAW264.7 cells, SGZ decreased the NLRP3 inflammasome components (ASC, cleaved IL-1β) and cytokine secretion. Co-cultures demonstrated that the SGZ-treated macrophage supernatants suppressed the fibroblast activation (α-SMA, collagen I) in MRC-5 cells. Conclusions: SGZ attenuates pulmonary fibrosis by suppressing macrophage-driven inflammation via NF-κB/NLRP3 inhibition and disrupting the macrophage–fibroblast crosstalk. These findings nominate SGZ as a promising candidate for preclinical optimization and future clinical evaluation in IPF. Full article

Growth Differentiation Factor 15 (GDF15), also known as non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1) or macrophage inhibitory cytokine 1 (MIC-1), is a stress- and inflammation-induced cytokine distantly related to the TGF-β superfamily. Its highly elevated levels showed close association with various pathological conditions, making it an emerging biomarker of disease prognosis. However, most GDF15-mediated effects under normal physiology and various pathological conditions are poorly understood. This is partly because the only known GDF15 receptor is exclusively localized in the brain, and how GDF15 functions peripherally is currently unknown. Mounting recent evidence has shown GDF15’s critical role in fibrosis in multiple organs, such as the liver, lung, and kidney. Evidence further suggests that it can either contribute to fibrosis by promoting inflammation and fibroblast activation or confer protective effects by modulating the immune response and mitigating fibrosis severity. Thus, the exact role of GDF15 in fibrosis can vary depending on the organ involved and the specific disease context. For example, increased GDF15 in idiopathic pulmonary fibrosis (IPF) promotes fibrosis via fibroblast activation and collagen deposition. Conversely, GDF15 might have a protective role in liver fibrosis, with decreased GDF15 levels causing increased fibrosis severity, while GDF15 treatment ameliorates fibrosis. Due to its close association with fibrosis, GDF15 is being investigated as a potential biomarker for disease severity and monitoring treatment response. However, further research unraveling its mechanisms of action is needed to explore the potential of GDF15 as a therapeutic target for treating fibrosis, either by modulating its expression or utilizing its immunomodulatory properties. This review marshals the limited studies addressing the recently appreciated differential role of GDF15 in regulating the fibrotic process in different organs. The review also discusses the aspects of further research needed to highlight GDF 15 as a novel predictor and therapeutic target for fibrosis in different organs. Full article

Background: Cancer and fibrotic diseases represent major global health challenges, underscoring the need for safe, multifunctional natural therapies. Although natural products possess notable anticancer properties, their clinical translation is often hindered by non-selective cytotoxicity toward normal cells. Moreover, their therapeutic potential against chronic conditions such as idiopathic pulmonary fibrosis (IPF) remains insufficiently explored. This study aimed to evaluate the efficacy and safety of a natural hydrosol blend, The Greatest Love of Nature (TGLON), in inhibiting cancer cell proliferation and mitigating IPF. Methods: TGLON, composed of 12 steam-distilled plant hydrosols, was chemically characterized by gas chromatography–mass spectrometry (GC-MS). Its cytotoxicity was assessed using the MTT assay against five human cancer cell lines (A-549, HepG2, MCF-7, MKN-45, and MOLT-4) and normal human lung fibroblasts (MRC-5). In vivo safety and therapeutic efficacy were evaluated in Sprague Dawley rats and a bleomycin-induced IPF mouse model, following protocols approved by the Institutional Animal Care and Use Committee (IACUC). Results: TGLON maintained >90% viability in MRC-5 cells at an 80-fold dilution and significantly inhibited the proliferation of A-549 (41%), HepG2 (84%), MCF-7 (50%), MKN-45 (38%), and MOLT-4 (52%) cells. No signs of toxicity were observed in rats administered TGLON orally at 50% (v/v), 10 mL/kg. In mice, TGLON alleviated bleomycin-induced pulmonary inflammation and fibrosis. Conclusions: TGLON exhibited selective anticancer and anti-fibrotic activities under non-toxic conditions, supporting its potential as a bioactive agent for early-stage disease prevention and non-clinical health maintenance. Full article

In a susceptible individual, persistent, low-level injury to the airway epithelium initiates an exaggerated wound repair response, ultimately leading to idiopathic pulmonary fibrosis (IPF). The mechanisms driving this fibroproliferative response are not fully understood. Here, we review recent spatially resolved transcriptomics and proteomics studies that provide insight into two distinct matricellular microenvironments important in this pathological fibroproliferation. First, in response to alveolar epithelial injury, alveolar differentiation intermediate (ADI) basal cells arising from Secretoglobin (Scgb1a1) progenitors re-populate the injured alveolus remodeling the extracellular matrix (ECM). ADI cells exhibit an interconnected cellular stress response involving the unfolded protein response (UPR), epithelial–mesenchymal transition (EMT) and senescence pathways. These pathways reprogram cellular metabolism to support fibrillogenic ECM remodeling. In turn, the remodeled ECM tonically stimulates EMT in the ADI population, perpetuating the transitional cell state. Second, fibroblastic foci (FF) are a distinct microenvironment composed of activated aberrant “basaloid” cells supporting transition of adjacent mesenchyme into hyaluronan synthase (HAS^hi)-expressing fibroblasts and myofibroblasts. Once formed, FF are the major matrix-producing factories that invade and disrupt the alveolar airspace, forming a mature scar. In both microenvironments, the composition and characteristics of the ECM drive persistence of atypical epithelium sustaining matrix production. New approaches to monitor cellular trans-differentiation and matrix characteristics using positron emission tomography (PET)–magnetic resonance imaging (MRI) and optical imaging are described, which hold the potential to monitor the effects of therapeutic interventions to modify the ECM. Greater understanding of the bidirectional interrelationships between matrix and cellular phenotypes will identify new therapeutics and diagnostics to affect the outcomes of this lethal disease. Full article

Secreted phosphoprotein 1 (SPP1), also known as osteopontin (OPN) or early T lymphocyte activation protein 1 (ETA-1), is a multifunctional protein involved in numerous biological processes, including immune modulation, stress response, and tissue remodeling. The role of SPP1 in interstitial lung diseases (ILDs) has become an area of increasing interest, given its elevated expression in various ILDs such as idiopathic pulmonary fibrosis (IPF), connective tissue disease-associated ILD (CTD-ILD), and pneumoconiosis, especially with recent data derived from single-cell RNA sequencing. In addition to ILDs, SPP1 has been implicated in infectious granulomatous lung diseases, lung and pleural malignancies, airway diseases, and COVID-19. In most cases, higher SPP1 levels in serum, bronchoalveolar lavage fluid, or lung tissue carry a poor prognosis. SPP1 is expressed in multiple cells critical for fibrogenesis, including macrophages, epithelial cells, and fibroblasts, and SPP1 has emerged as a potential target for therapeutic interventions. Here, we review the proposed mechanisms by which SPP1 contributes to the development of lung disease, with an emphasis on ILD. Full article

Background/Objectives: Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterized by excessive extracellular matrix (ECM) production and tissue stiffening, resulting in impaired lung function. Sodium hydrogen exchanger isoform 1 (NHE1) is a key mediator of intracellular and extracellular pH regulation, influencing fibroblast activation, motility, and proliferative pathways. This study investigates the role of NHE1 in actin stress fiber formation, fibroblast-to-myofibroblast differentiation, and cytokine secretion in IPF progression. Methods: Fibroblasts were treated with profibrotic agonists, including transforming growth factor-beta (TGFβ), lysophosphatidic acid (LPA), and serotonin (THT), in the presence or absence of the NHE1-specific inhibitor, EIPA. Actin stress fibers were visualized using phalloidin staining, while α-smooth muscle actin (α-SMA) expression and cytokine secretion (TGFβ, IL-6, and IL-8) were quantified using immunostaining and ELISA. Intracellular pH changes were measured using BCECF-AM fluorescence. Results: Profibrotic agonists induced significant actin stress fiber formation and α-SMA expression in fibroblasts, both of which were abolished by EIPA. NHE1 activity was shown to mediate intracellular alkalization, a critical factor for fibroblast activation. Cytokine secretion, including TGFβ, IL-6, and IL-8, was enhanced by agonist treatments but reduced with NHE1 inhibition. Chronic TGFβ exposure increased intracellular pH and sustained myofibroblast differentiation, which was partially reversed by EIPA. Conclusions: NHE1 is indicated to play a novel and potential role in processes supporting profibrotic agonists driving fibroblast activation and IPF progression. Targeting NHE1 could present a potential therapeutic approach to disrupt profibrotic pathways and mitigate IPF severity. Full article

Idiopathic pulmonary fibrosis (IPF) is a disease with a poor prognosis and no curative therapies. Fibroblast activation by transforming growth factor β1 (TGFβ1) and disrupted metabolic pathways, including the arginine–polyamine pathway, play crucial roles in IPF development. Polyamines are agonists of the calcium/cation-sensing receptor (CaSR), activation of which is detrimental for asthma and pulmonary hypertension, but its role in IPF is unknown. To address this question, we evaluated polyamine abundance using metabolomic analysis of IPF patient saliva. Furthermore, we examined CaSR functional expression in human lung fibroblasts (HLFs), assessed the anti-fibrotic effects of a CaSR antagonist, NPS2143, in TGFβ1-activated normal and IPF HLFs by RNA sequencing and immunofluorescence imaging, respectively; and NPS2143 effects on polyamine synthesis in HLFs by immunoassays. Our results demonstrate that polyamine metabolites are increased in IPF patient saliva. Polyamines activate fibroblast CaSR in vitro, elevating intracellular calcium concentration. CaSR inhibition reduced TGFβ1-induced polyamine and pro-fibrotic factor expression in normal and IPF HLFs. TGFβ1 directly stimulated polyamine release by HLFs, an effect that was blocked by NPS2143. This suggests that TGFβ1 promotes CaSR activation through increased polyamine expression, driving a pro-fibrotic response. By halting some polyamine-induced pro-fibrotic changes, CaSR antagonists exhibit disease-modifying potential in IPF onset and development. Full article

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. Full article