Search Results (135)

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

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

Acute Respiratory Distress Syndrome (ARDS) is a complex and devastating form of respiratory failure, with high mortality rates, for which there is no pharmacological treatment. The acute exudative phase of ARDS is characterized by severe damage to the alveolar–capillary barrier, infiltration of protein-rich fluid into the lungs, neutrophil recruitment, and high levels of inflammatory mediators. Rapid resolution of this reversible acute phase, with efficient restoration of alveolar functional integrity, is essential before the establishment of irreversible fibrosis and respiratory failure. Several lines of in vitro and in vivo evidence support the involvement of potassium (K⁺) channels—particularly KvLQT1, expressed in alveolar cells—in key cellular mechanisms for ARDS resolution, by promoting alveolar fluid clearance and epithelial repair processes. The aim of our study was to investigate whether pharmacological activation of KvLQT1 channels could elicit beneficial effects on ARDS parameters in an animal model of acute lung injury. We used the well-established bleomycin model, which mimics (at day 7) the key features of the exudative phase of ARDS. Our data demonstrate that treatments with the KvLQT1 activator R-L3, delivered to the lungs, failed to improve endothelial permeability and lung edema in bleomycin mice. However, KvLQT1 activation significantly reduced neutrophil recruitment and tended to decrease levels of pro-inflammatory cytokines/chemokines in bronchoalveolar lavages after bleomycin administration. Importantly, R-L3 treatment was associated with significantly lower injury scores, higher levels of alveolar type I (HTI-56, AQP5) and II (pro-SPC) cell markers, and improved alveolar epithelial repair capacity in the presence of bleomycin. Together, these results suggest that the KvLQT1 K⁺ channel may be a potential target for the resolution of the acute phase of ARDS. Full article

Background: Pulmonary fibrosis (PF), the end-stage manifestation of interstitial lung disease, is defined by excessive extracellular matrix deposition and alveolar destruction. Activated fibroblasts, the primary matrix producers, rely heavily on dysregulated glucose metabolism for their activation. While Salt Inducible Kinase 2 (SIK2) regulates glycolytic pathways in oncogenesis, its specific contributions to fibroblast activation and therapeutic potential in PF pathogenesis remain undefined. This study elucidates the functional role of SIK2 in PF and assesses its viability as a therapeutic target. Methods: SIK2 expression/localization in fibrosis was assessed by Western blot and immunofluorescence. Fibroblast-specific Sik2 KO mice evaluated effects on bleomycin-induced fibrosis. SIK2’s role in fibroblast activation and glucose metabolism impact (enzyme expression, metabolism assays, metabolites) were tested. SIK2 inhibitors were screened and evaluated therapeutically in fibrosis models. Results: It demonstrated significant SIK2 upregulation, specifically within activated fibroblasts of fibrotic lungs from both PF patients and murine models. Functional assays demonstrated that SIK2 is crucial for fibroblast activation, proliferation, and migration. Mechanistically, SIK2 enhances fibroblast glucose metabolism by increasing the expression of glycolysis-related enzymes. Additionally, this study demonstrated that the SIK2 inhibitor YKL06-061 effectively inhibited PF in both bleomycin and FITC-induced PF mouse models with the preliminary safety profile. Furthermore, we identified a novel therapeutic application for the clinically approved drug fostamatinib, demonstrating it inhibits fibroblast activation via SIK2 targeting and alleviates PF in mice. Conclusions: Our findings highlight SIK2 as a promising therapeutic target and provide compelling preclinical evidence for two distinct anti-fibrotic strategies with significant potential for future PF treatment. 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

Background: Localized scleroderma (LoS) is a chronic autoimmune condition marked by cutaneous fibrosis and persistent inflammation. Modulating the activation of inflammatory cells and fibroblasts remains a central strategy in LoS treatment. We investigate the anti-fibrotic effects of Annexin A5 (AnxA5), identified as a key inflammatory component in fat extract, and assess its therapeutic efficacy. Methods: In vitro experiments were performed using TGF-β-stimulated primary human dermal fibroblasts treated with recombinant AnxA5. The anti-fibrotic effects and underlying mechanisms were assessed using CCK-8 assays, quantitative real-time PCR, Western blotting, and immunocytochemistry. In vivo, AnxA5 was administered via both preventative and therapeutic protocols in bleomycin-induced LoS mouse models. Treatment outcomes were evaluated by histological staining, collagen quantification, immunostaining, and measurement of pro-inflammatory cytokines. Results: TGF-β stimulation induced myofibroblast differentiation and extracellular matrix (ECM) production in dermal fibroblasts, both of which were significantly attenuated by AnxA5 treatment through the inhibition of phosphorylation of Smad2. In vivo, both preventative and therapeutic administration of AnxA5 effectively reduced dermal thickness, collagen deposition, ECM accumulation, M1 macrophage infiltration, and levels of pro-inflammatory cytokines. Conclusions: Through both preventative and therapeutic administration, AnxA5 ameliorates LoS by exerting dual anti-fibrotic and anti-inflammatory effects, underscoring its potential for treating fibrotic diseases. 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

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

Background: Pulmonary fibrosis (PF) is a progressive interstitial lung disease characterized by chronic inflammation and excessive extracellular matrix deposition, with fibrocytes playing a pivotal role in fibrotic remodeling. This study aimed to identify upstream molecular mechanisms regulating fibrocyte recruitment and activation, focusing on the SPHK1 pathway as a potential therapeutic target. Methods: We utilized Mendelian Randomization and phenome-wide association analyses on genes involved in sphingolipid metabolism to identify potential regulators of idiopathic pulmonary fibrosis (IPF). A bleomycin-induced mouse model was employed to examine the role of the SPHK1-S1P axis in fibrocyte recruitment, using SKI-349 to target SPHK1 and FTY720 to antagonize S1PR1. Results: Our analyses revealed SPHK1 as a significant genetic driver of IPF. Targeting SPHK1 and S1PR1 led to a marked reduction in fibrocyte accumulation, collagen deposition, and histopathological fibrosis. Additionally, PAXX and RBKS were identified as downstream effectors of SPHK1. Our protein–protein interaction mapping indicated potential therapeutic synergies with existing anti-fibrotic drug targets. Conclusions: Our findings establish the SPHK1-S1P-S1PR1 axis as a key regulator of fibrocyte-mediated pulmonary fibrosis and support SPHK1 as a promising therapeutic target. Full article

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterized by the fibrotic thickening of the alveolar walls, resulting in compromised gas exchange, restricted ventilation, and respiratory failure. It has been indicated that elastase inhibitors reduced the severity of IPF by neutralizing excessive elastase levels in the lungs. ShSPI is an elastase inhibitor derived from centipede toxin. The present study evaluates the therapeutic effects of ShSPI in a bleomycin-induced idiopathic pulmonary fibrosis model. According to the results, ShSPI markedly reduced the weight loss, showing the improvement of health status in bleomycin-induced mice. Its robust antifibrotic effects were evidenced by the mitigation of alveolar structural damage, reduction in inflammatory cell infiltration, inhibition of collagen deposition, and suppression of fibrotic nodule formation. ShSPI effectively attenuated inflammatory responses by downregulating pro-inflammatory factors (IL-6, IL-1β, and MCP-1) and upregulating the anti-inflammatory factor interleukin-10 (IL-10). After delivered via inhalation, ShSPI exhibited favorable pharmacokinetic properties. It could be detected at 8 h at doses of 1 mg/kg and achieved maximum plasma concentrations (Cmax) of 188.00 ± 64.40 ng/mL in vivo. At high doses (160 mg/kg), ShSPI maintained a strong safety profile, with no detectable toxicity observed. This feature shows the therapeutic potential of ShSPI in the treatment of idiopathic pulmonary fibrosis and provides valuable evidence for its development as a novel peptide-based therapy. Full article

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

This paper investigates the ability of our selective small molecule TG2 inhibitor 1-155 in reducing fibrosis in a bleomycin-induced pulmonary fibrosis mouse model. Formulated as a fine stable suspension, 1-155 was delivered intranasally (IN) at 3 mg/kg via IN delivery once daily. It significantly inhibited collagen deposition in the lungs in the bleomycin-challenged mice. Compared to its vehicle control treatment, a significant reduction in a key myofibroblast marker α smooth muscle actin and TG2 was also detected in the 1-155-treated animals. Most importantly, 1-155 treatment significantly improved several key lung function parameters, such as cord compliance, vital capacity, and dynamic compliance, which are comparable to that found for the positive control nintedanib at a much higher dosage of 60 mg/kg twice daily via oral delivery. The 1-155-treated mice showed a trend in improvement of average body weight. For the first time, our study demonstrates the effectiveness of a selective small molecule TG2 inhibitor in reducing pulmonary fibrosis in a pre-clinical model. Importantly, we were able to correlate this effect of 1-155 with the improvement of animal lung function showing the potential of the use of TG2 inhibitors as a therapeutic treatment for fibrotic lung conditions like IPF. Full article

Systemic sclerosis (SSc) is a complex autoimmune disease characterized by fibrosis, immune dysregulation, and vascular dysfunction, yet its pathogenesis remains incompletely understood. This study compares two widely used animal models of SSc—the bleomycin-induced fibrosis model and the collagen-V-induced autoimmune model—to evaluate their ability to replicate key disease features. In the bleomycin model, consistent cardiac fibrosis was observed across treatment groups despite variability in fibrosis in the skin and lungs, suggesting organ-specific differences in susceptibility. The collagen-V model demonstrated robust autoantibody production against collagen-V, confirming its utility in studying immune activation, though fibrosis was largely confined to the heart. While the bleomycin model excels at mimicking rapid fibrosis and is suitable for testing antifibrotic therapies, the collagen-V model provides insights into antigen-specific autoimmunity. Both models highlight the dynamic nature of fibrosis, where ECM deposition and degradation occur concurrently, complicating its use as a quantitative disease marker. Cardiac fibrosis emerged as a consistent feature in both models, emphasizing its relevance in SSc pathophysiology. Combining these models or refining their design through hybrid approaches, extended timelines, or sex and age adjustments could enhance their translational utility. These findings advance understanding of SSc mechanisms and inform therapeutic development for this challenging disease. Full article

Tissue fibrosis, characterized by excessive collagen accumulation, leads to impaired organ function and is a hallmark of various chronic diseases. Fibroblasts play a central role in collagen production and deposition. This study examines the impact of ursolic acid, a pentacyclic triterpenoid compound present in various fruits and vegetables, on collagen homeostasis in primary human dermal fibroblasts. Ursolic acid (UA) was observed to significantly reduce collagen production while markedly increasing the activity of matrix metalloproteinase-1 (MMP-1), an enzyme responsible for collagen degradation. Mechanistically, ursolic acid was found to inhibit TGF-β/Smad signaling, leading to decreased collagen production, and to activate mitogen-activated protein kinase (MAPK) pathways and activator protein 1 (AP-1), resulting in enhanced MMP-1 production. These in vitro findings were further validated in an in vivo mouse model of fibrosis, where ursolic acid significantly mitigated bleomycin-induced skin fibrosis. These results suggest that UA could be a promising candidate for treating skin fibrosis due to its dual effects on collagen homeostasis: inhibiting collagen production and promoting collagen degradation. Full article

Background/Objectives: The identification of inflammatory mediators and the involvement of CD206 macrophages in anti-inflammatory responses, along with the synthesis of fibrotic mediators, are crucial for the diagnosis and treatment of Idiopathic Pulmonary Fibrosis (IPF). Methods: In this study, the assessment of ⁶⁸Ga-labeled linear and cyclic forms of the RP832c peptide, which demonstrate a specific affinity for CD206 macrophages, was performed to evaluate efficacy for CD206 imaging through PET/CT, biodistribution studies, and CD206 staining in a bleomycin-induced lung injury mouse model (BLM). This model serves as a representative framework for inflammation and fibrosis. Results: The findings reveal significant peak PET/CT signals (SUV means), ID/gram values, and CD206 staining scores in lung tissues at one week post bleomycin instillation, likely due to the heightened expression of CD206 in the bleomycin-induced lung injury model. In contrast, the healthy mice exhibited no detectable CD206 staining, lower PET signals, and reduced radiopharmaceutical accumulation in lung tissues at the same timepoint. Conclusions: These findings suggest that both linear and cyclic [⁶⁸Ga]Ga-RP832c may function as promising PET imaging agents for CD206 macrophages, and thereby a strategy to non-invasively explore the role of macrophages during fibrogenesis. Full article