Search Results (237)

Idiopathic pulmonary fibrosis (IPF) remains a progressive and fatal disease despite major advances in antifibrotic therapy. Pirfenidone and nintedanib slow lung function decline, and the PDE4B inhibitor nerandomilast and treprostinil have recently shown promise as next-generation treatments. However, current therapies neither halt nor reverse disease progression, and tolerability issues often limit adherence. We compared the antifibrotic activity and plasma levels of nintedanib administered by either oral gavage or dietary supplementation in a rat model of pulmonary fibrosis. Male Sprague-Dawley rats received intratracheal bleomycin (1 U/kg) on days 0 and 4. From day 7 to day 28, animals were treated with nintedanib (100 mg/kg/day) by either oral gavage or medicated chow. Lung weight, fibrosis biomarkers (procollagen-I, metalloproteinase-7 or MMP7, WNT1-inducible signaling pathway protein or WISP-1), epithelial injury marker KL-6, target engagement biomarkers (Fibroblast Growth Factor 2 or FGF-2, Vascular Endothelial Growth Factor or VEGF), plasma drug levels, and histological fibrosis scores were evaluated. Both administration regimens significantly reduced procollagen-I, WISP-1 and KL-6, and histological fibrosis scores. Oral gavage produced approximately fourfold-higher peak plasma concentrations of nintedanib 30 min after dosing, whereas dietary administration resulted in lower, more stable plasma levels with reduced variability while resulting in comparable antifibrotic efficacy. In conclusion, nintedanib retained robust antifibrotic activity when administered via dietary supplementation despite lower, but continuous, active plasma concentrations. Collectively, these findings indicate that optimizing drug delivery and absorption kinetics may achieve sustained therapeutic efficacy while reducing unnecessary exposure to supratherapeutic concentrations, thereby potentially improving tolerability. Full article

Background: Pulmonary fibrosis (PF) is a progressive lung disease with limited therapies. Oral Pirfenidone (PFD), an approved anti-fibrotic, shows poor lung bioavailability and significant toxicity. S-Allylmercapto-N-acetylcysteine (ASSNAC) has been demonstrated to possess significant anti-inflammatory and antioxidant properties. Methods: In this study, dry powder inhaler formulations (DPIs) co-encapsulating ASSNAC and PFD in liposomes are reported. The formulation was prepared via spray freeze-drying (SFD) using L-leucine as both a cryoprotectant and a surface morphology modifier. The interfacial enrichment of L-leucine during atomization and freezing created a hydrophobic, corrugated surface that lowered particle surface energy, prevented liquid/solid bridge formation, and reduced hygroscopicity. Results: The resulting liposomal powders exhibited optimal aerosol performance: fine particle fraction (FPF) of 61.08% ± 2.45% and mass median aerodynamic diameter (MMAD) of 2.22 ± 0.11 µm. Cellular studies demonstrated that dual-loaded liposomes were efficiently taken up by Beas-2B and HFL-1 cells, with no cytotoxicity (cell viability > 90%) and negligible hemolysis. In the TGF-β1-induced in vitro fibrosis model, the combined treatment exerted prominent therapeutic effects. This regimen preserved normal epithelial morphology, accelerated wound repair, suppressed fibroblast invasiveness, and lowered the expression levels of Collagen I, Collagen III, and α-SMA. In bleomycin-induced pulmonary fibrosis rats, inhaled ASSNAC + PFD liposomal powder markedly relieved lung tissue injury and collagen accumulation. It restored redox balance and lowered pulmonary TGF-β1, hydroxyproline and collagen III levels. The formulation blocked TGF-β1 signaling and fibrotic gene expression. Conclusions: Pulmonary administration avoids oral pirfenidone-induced liver and stomach toxicity. Collectively, the ASSNAC + PFD co-encapsulated liposomal dry powder produced by SFD represents a safe and efficacious therapeutic strategy for PF. Full article

Background: Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease driven by aberrant extracellular matrix deposition, with the activity of transforming growth factor-beta 1 (TGF-β1) orchestrating fibrogenesis. Current therapies are limited by severe adverse effects, highlighting the unmet need for safer treatments. In this study, the therapeutic potential of chlorogenic acid (CGA) in a murine model of pulmonary fibrosis was evaluated. Methods: Pathology was induced on day 0 via subcutaneous osmotic minipumps delivering bleomycin (BLM) for one week, followed by pump removal on day 10. Therapeutic interventions with intragastric CGA (60 mg/kg) were administered daily from days 14 to 20. Lung tissue samples obtained on day 21 were analyzed via histological, immunohistochemical, and RT–PCR methods. Results: Histological analysis via H&E and Masson’s trichrome staining revealed that CGA treatment significantly attenuated alveolar thickening, restored the alveolar space, and reduced the total cell density and Ashcroft fibrosis score. Furthermore, CGA markedly decreased collagen deposition. Quantitative RT–PCR and immunohistochemical assays revealed that CGA effectively decreased the expression of Col1a1, TGF-β1, and the myofibroblast marker alpha-smooth muscle actin (α-SMA). Conclusions: CGA exerts important therapeutic effects by decreasing the expression of TGF-β1 and the activation of myofibroblasts, indicating that this natural polyphenol is a promising candidate for mitigating the progression of pulmonary fibrosis. Full article

Background/Objectives: Mesenchymal stromal cells from the amniotic membrane (hAMSCs) counteract fibrosis progression, primarily via anti-inflammatory effects like promoting macrophage polarization toward an anti-inflammatory, pro-regenerative phenotype. Methods: We investigated hAMSCs’ ability to prevent and halt lung fibrosis in a bleomycin-induced fibrosis murine model. We focused on their impact on recruitment and polarization of different macrophage populations, including SPARC- and CD169-expressing macrophages, implicated in resolving pulmonary inflammation and fibrosis. Results: hAMSCs, administered early (concomitant with bleomycin, during acute inflammation), or late (at day 7 post-bleomycin, during established fibrosis), showed anti-fibrotic activity, preserving alveolar area, reducing the extent of lung fibrosis, and decreasing α-SMA levels. These preventive and late anti-fibrotic effects of hAMSCs are associated with a context-dependent presence of distinct macrophage signatures. Early treatment reduced macrophage recruitment and increased levels of Arg1⁺/iNOS⁻ macrophages, curbing injury-induced inflammation. Late treatment uniquely increased the lung levels of CD169⁺ macrophages, suggesting their contribution to hAMSCs’ anti-fibrotic effect. We hypothesized a potential involvement of lung CD169⁺ macrophages in promoting recruitment of regulatory T cells (Tregs) to the lungs. Although these macrophages can establish a CCL22-CCR4 axis with Tregs, and treatment effectively boosted Treg lung levels, the Treg increase is not directly attributable to higher CD169⁺ macrophage numbers, implying other potentially IL-10-driven mechanisms. Conclusions: hAMSC treatment effectively prevents and blocks lung fibrosis. These effects are associated with distinct lung macrophage marker profiles, suggesting a potential involvement of different macrophage populations in a time-dependent manner; thus highlighting administration timing’s role in optimizing therapeutic synergy. Full article

Background: Pulmonary fibrosis is a chronic and progressive disease characterized by excessive deposition of extracellular matrix and scarring of lung tissue, resulting in a gradual decline in respiratory function. Despite advances in understanding its pathogenesis, effective therapeutic options remain limited. This study aimed to evaluate the antifibrotic effects of concentrated polyphenolic extracts obtained from bilberry (Vaccinium uliginosum), cranberry (Vaccinium oxycoccos), and lingonberry (Vaccinium vitis-idaea) in a bleomycin-induced rat model of pulmonary fibrosis. Methods: Pulmonary fibrosis was induced in rats through the intratracheal administration of bleomycin. Beginning seven days after fibrosis induction, concentrated polyphenolic extracts from the three Vaccinium species were administered orally for 14 consecutive days. Lung histomorphology, inflammatory cell infiltration, collagen composition, and hemorheological parameters were subsequently evaluated. Results: Treatment with the berry polyphenolic extracts reduced the severity of bleomycin-induced pulmonary fibrosis and decreased inflammatory cell infiltration in lung tissue. The extracts also influenced collagen remodeling, promoting a relative predominance of immature type III collagen over mature type I collagen. Furthermore, bleomycin-induced pulmonary fibrosis was accompanied by increased blood viscosity, whereas treatment with the polyphenolic extracts partially normalized the altered hemorheological parameters. Conclusions: Concentrated polyphenolic extracts derived from Vaccinium species demonstrated antifibrotic, anti-inflammatory, and hemorheological effects in experimental pulmonary fibrosis. These findings support further investigation of their underlying molecular mechanisms and potential translational applications studies. Full article

Trained immunity (TI) represents a form of immune memory in innate immune cells, driven by sustained epigenetic and metabolic reprogramming that potentiates innate immune responses. Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease characterized by persistent alveolar injury and pathological tissue remodeling. Given the central role of macrophages in IPF pathogenesis, we hypothesized that inducing TI could functionally reprogram these cells and attenuate fibrosis. In a murine model of pulmonary fibrosis induced by bleomycin, prior induction of TI via β-glucan enhanced autophagic activity in macrophages and reduced pathological collagen deposition. This trained response restricted bleomycin-triggered mitochondrial DNA release and suppressed the mitochondrial apoptosis pathway, thereby promoting macrophage survival. The protective effects were diminished by administration of the AMPK inhibitor Compound C. Our findings indicate that TI promotes mitophagy correlating with the AMPK-ULK1 signaling axis, thereby reducing alveolar macrophage apoptosis and uncovering a potential therapeutic strategy for pulmonary fibrosis. Full article

Background: Idiopathic pulmonary fibrosis (IPF) is closely associated with fibroblast proliferation, macrophage polarization, and the accumulation of extracellular matrix (ECM). Targeting CSF-1R can rebalance macrophages, reduce ECM deposition, and block pro-fibrotic signaling. Methods: A Fab fragment targeting CSF-1R was screened via phage display. After sequence optimization, it was constructed into an IgG1 antibody (BC006). In vitro activity, domain binding, and signaling blockade were investigated, and in vitro safety indicators were evaluated. Efficacy was assessed using an induced IPF organoid-on-a-chip and bleomycin-induced mouse model. In vivo safety evaluation was conducted in cynomolgus monkeys. Results: BC006 showed an EC₅₀ value of 226 ± 57 nM and a KD of 30 ± 2 nM. It specifically bound to the Ig4-5 domain of CSF-1R by inhibiting receptor dimerization without blocking ligand binding. It could dose-dependently inhibit the differentiation of monocytes into M2 macrophages and exert anti-IPF effects. In the induced IPF organoid-on-a-chip model, BC006 maintained lung barrier function and decreased α-SMA and Collagen I. It also improved lung function and attenuated the degree of fibrosis in the mouse model. Moreover, BC006 had no ADCC, CDC, cytokine release, or hemagglutination, and demonstrated favorable safety profiles in cynomolgus monkeys. Conclusions: BC006 is a novel anti-fibrosis antibody specifically targeting the CSF-1R Ig4-5 domain and offers a new therapeutic strategy for IPF. Full article

Background/Objectives: Pulmonary fibrosis is a progressive and fatal disease characterized by excessive extracellular matrix deposition and irreversible lung remodeling. Although modified mRNA (modRNA) therapeutics offer a promising strategy for regulating disease-driving pathways, effective pulmonary delivery remains challenging due to the inherent liver tropism of conventional lipid nanoparticles (LNPs). This study aimed to establish an optimized platform for lung-selective modRNA delivery and therapeutic screening for pulmonary fibrosis. Methods: A panel of charge-modified LNP formulations was evaluated in vivo for pulmonary tropism following systemic administration of luciferase (Luc) modRNA. Administration routes, biodistribution in healthy and bleomycin (BLM)-induced fibrotic lungs, and endogenous microRNA (miRNA)-mediated de-targeting strategies were assessed. Candidate antifibrotic modRNAs targeting the transforming growth factor-beta (TGF-β) signaling pathway were subsequently evaluated in normal human lung fibroblasts (NHLFs). Results: Among the formulations tested, 50% DOTAP MC3 LNPs demonstrated the most favorable balance of pulmonary transfection, physicochemical properties, and limited off-target expression. Intravenous (IV) administration achieved robust lung expression with a superior safety profile compared with intratracheal (IT) delivery. Importantly, pulmonary biodistribution was preserved in BLM-induced fibrotic lungs despite extensive tissue remodeling. Incorporation of miR-122 recognition sites further enhanced selectivity, resulting in 94.5% of total transgene expression being localized to the lungs while substantially reducing residual hepatic expression. In vitro screening identified dominant-negative TGF-β receptor II (DNTGFBR2) modRNA as a potent inhibitor of TGF-β-induced fibrotic activation, significantly suppressing α-SMA and CTGF expression. Conclusions: These findings establish a comprehensive platform for pulmonary modRNA therapeutic development by integrating lung-selective LNP engineering, optimal systemic delivery, miRNA-mediated de-targeting, and therapeutic payload screening. This strategy provides a foundation for the development of targeted RNA therapies for pulmonary fibrosis and other organ-specific diseases. Full article

This study investigated the mechanism of TGF-β1-induced Nox4 expression in pulmonary fibrosis (PF) and the anti-fibrotic effects of Tanshinone IIA (Tan-IIA). In a bleomycin-induced pulmonary fibrosis mouse model and in TGF-β1-stimulated fibroblasts, Tan-IIA attenuated fibrosis, oxidative stress, and fibroblast activation. Pharmacological inhibition revealed that the JNK/c-Jun and Smad3 pathways cooperatively mediate TGF-β1-induced expression of Nox4 and fibrotic markers (Collagen I/III, α-SMA). Tan-IIA exerted these effects by dually inhibiting the JNK/c-Jun and Smad2/3 pathways, reducing their phosphorylation and nuclear signaling, which consequently suppressed Nox4 transcription and protein expression. The combination of Tan-IIA with JNK or Smad3 inhibitors synergistically enhanced these effects. We identified a tandem c-Jun/Smad binding element in the Nox4 promoter that is critical for TGF-β1 response. Reporter assays and CUT&RUN experiments confirmed that TGF-β1-induced transcriptional activation depends on an intact c-Jun/Smad binding element and recruitment of c-Jun and Smad2/3. Moreover, Tan-IIA inhibited the enrichment of c-Jun and Smad2/3 at the Nox4 promoter. Collectively, our findings demonstrate that a c-Jun/Smad element integrates profibrotic JNK and Smad signaling to drive Nox4 expression. Tan-IIA presents a novel therapeutic strategy for fibrosis by simultaneously targeting these two key pathways, thereby mitigating Nox4-dependent oxidative stress and fibroblast activation. Full article

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease with limited therapeutic options. To investigate the roles of the pulmonary microbiota and metabolism in fibrosis, we established a bleomycin (BLM)-induced mouse model at 14- and 28-day timepoints and performed integrated 16S rRNA gene amplicon sequencing and untargeted metabolomic analyses. Histological and Western blot analyses confirmed significant fibrotic changes and the upregulation of fibrotic markers. Microbiome profiling revealed marked dysbiosis after BLM exposure, characterized by reduced microbial diversity and enrichment of Klebsiella. LC-MS–based metabolomic analysis identified substantial perturbations in the lung tissue metabolome, particularly in lipid metabolism, amino acid metabolism, and energy pathways. Correlation analysis indicated a strong positive association between the abundance of Klebsiella and the levels of specific dipeptides, including Ala-Hyp-Gly, Asp-His, and Asp-Asn. The accumulation of these dipeptides may reflect increased collagen degradation and turnover in fibrotic lungs. Collectively, our findings demonstrate that BLM-induced pulmonary fibrosis is accompanied by coordinated alterations in the lung microbiome and metabolome. Notably, microbial dysbiosis, particularly the expansion of Klebsiella, may be associated with alterations in amino acid metabolism and fibrotic progression. Full article

Background: Solriamfetol, a dopamine and norepinephrine reuptake inhibitor widely used in narcolepsy management, has not been thoroughly investigated for its anti-fibrotic and anti-inflammatory properties. Herein, we investigated its potential therapeutic applications and underlying mechanisms in both cellular and murine models of pulmonary fibrosis. Methods: To induce fibrosis, C57BL/6 male mice (six-week-old) were administered bleomycin via the intratracheal route. These animals subsequently received solriamfetol orally once per day at dosages of 3 or 10 mg/kg. Histological and immunohistochemical techniques were employed to evaluate inflammatory cell infiltration, collagen accumulation, and α-smooth muscle actin (α-SMA) expression in bronchoalveolar lavage samples and lung tissue sections. Cytokine levels were measured by ELISA, and gene/protein expression of pro-fibrotic markers, A_2A/A_2B adenosine receptors (ARs), adenylate cyclases (ACs), Epac, K_Ca3.1, and adenosine deaminase (ADA) were assessed via quantitative PCR and Western blot. Electrophysiological recordings evaluated K_Ca3.1 channel activity. Purified ADA and normal human lung fibroblasts (NHLFs) were treated with solriamfetol to assess effects on ADA activity and levels of cAMP and adenosine, respectively. Results: Solriamfetol significantly reduced inflammatory cell infiltration, collagen accumulation, and α-SMA expression in fibrotic lungs. Solriamfetol restored downregulated A_2AAR, A_2BAR, ACs, and Epac, while suppressing ADA expression and activity, resulting in elevated extracellular adenosine and intracellular cAMP. The intervention potentiated Epac signaling and inhibited fibroblast activation. Solriamfetol inhibited the K_Ca3.1 current in fibroblasts and reduced K_Ca3.1 protein expression levels in TGFβ-treated fibroblasts and lung tissues from bleomycin-challenged mice. Notably, these effects were abolished by A_2AAR or A_2BAR antagonists, implying that they occur through AR-mediated pathways. Conclusions: Solriamfetol inhibits ADA and reinforces adenosine–cAMP signaling, suppressing pathological fibroblast activation. These findings suggest its therapeutic utility as a novel anti-fibrotic compound for various fibrotic diseases, including pulmonary fibrosis. Full article

Reproducible experimental models of localized dermal–hypodermal fibrosis are essential for standardized investigation of regenerative interventions. Variability in bleomycin dosing, anatomical targeting, and assessment strategies limits cross-study comparability. This study describes a methodological framework for standardized induction of early dermal–hypodermal remodeling in a rat model followed by autologous subcutaneous tissue grafting and multimodal longitudinal evaluation. Female Wistar rats underwent subcutaneous bleomycin administration at 1 mg/kg/day for three consecutive days. Clinical documentation, high-frequency ultrasonography with fixed imaging parameters, and sequential biopsies from a predefined thoracic anatomical site were performed at baseline, intermediate reassessment, and final evaluation. Autologous subcutaneous tissue grafting was conducted at Day 17 after study initiation. The protocol enabled controlled induction of early structural remodeling and consistent longitudinal documentation of dermal–hypodermal thickness, echogenicity changes, and histological architecture within a standardized anatomical region. This protocol development study establishes a reproducible and spatially consistent experimental platform integrating imaging and histological assessment, facilitating future hypothesis-driven investigations of fibrotic remodeling and regenerative strategies. Full article

Background/Objectives: Bleomycin is an antineoplastic antibiotic used in the management of various malignancies. Nevertheless, its benefits are constrained by the development of pulmonary fibrosis. Amentoflavone, a biflavonoid, exhibits diverse pharmacological activities, including anti-inflammatory, antiviral, antioxidant, and antitumor effects, whereas alogliptin possesses antioxidant and anti-inflammatory properties. This study aimed to assess the potential protective effects of alogliptin and/or amentoflavone in a murine model of bleomycin-induced pulmonary fibrosis and to clarify the underlying mechanisms. Methods: Fifty male C57BL/6 mice were randomly divided into 5 equal groups: control, bleomycin, bleomycin + alogliptin, bleomycin + amentoflavone, and bleomycin + alogliptin + amentoflavone. The assessed endpoints included lung weight/body weight index, lung tissue fibrotic mediators, oxidative stress parameters, proinflammatory cytokines, and pyroptotic and autophagy mediators. Also, the bronchoalveolar lavage fluid (BALF) was evaluated for total and differential leukocytic counts and lactate dehydrogenase (LDH) activity. Moreover, vascular responses to potassium chloride, phenylephrine, and carbachol, together with tracheal responses to carbachol were determined. Lung tissues were further examined histopathologically and immunohistochemically. Results: Treatment with alogliptin and/or amentoflavone significantly decreased the lung weight/body weight index and BALF LDH activity, concomitant with mitigation of lung tissue oxidative stress parameters, fibrotic mediators, apoptosis, and pyroptosis with a significant augmentation of autophagy signals, alongside marked improvement in the lung architecture and vascular and airway reactivity compared with the bleomycin group. These effects were most pronounced with animals treated with the alogliptin/amentoflavone combination. Conclusions: These findings suggest that combined alogliptin and amentoflavone may constitute a promising strategy to prevent bleomycin-induced lung fibrosis. Full article

Background: Pulmonary fibrosis (PF) is a chronic, progressive lung disease with limited treatment options. Liuweidihuang pill (LDP), a classical formula for kidney-yin deficiency, has been reported to have anti-inflammatory and anti-oxidative activities, suggesting potential relevance to PF. Purpose: This study evaluated whether LDP attenuates bleomycin-induced PF in mice and whether gut microbiota remodeling may contribute to its protective effects. Methods: Mice received intratracheal bleomycin followed by LDP gavage. Lung pathology was assessed by hematoxylin–eosin (HE) and Masson staining. Inflammatory cytokines, hydroxyproline (HYP), and α-SMA were measured. LDP and LDP-containing serum were profiled by UPLC-MS. The gut microbiota was analyzed using 16S rDNA sequencing. To further explore whether microbiota-related changes were associated with the protective phenotype, fecal microbiota transplantation (FMT) and probiotic VSL#3 intervention were performed. In addition, LDP-containing serum was tested in a TGF-β1-induced EMT model in A549 cells. Results: LDP reduced lung index, inflammatory infiltration, interstitial fibrosis, α-SMA expression, HYP content, and pro-inflammatory cytokine levels in bleomycin-treated mice. These effects were accompanied by gut microbiota remodeling and transcriptomic changes related to inflammation, metabolism, and fibrosis. VSL#3 partially reproduced the protective phenotype, whereas FMT showed limited efficacy. LDP-containing serum had a limited inhibitory effect on EMT inhibited EMT in vitro, suggesting that systemic host responses may contribute to the in vivo effect. Conclusions: LDP attenuated early bleomycin-induced PF and was associated with reduced inflammation and gut microbiota remodeling. These findings suggest a possible role for microbiota–host interactions in LDP-associated protection; however, causal directionality, key active effectors, and protein-level pathway validation remain unresolved. Full article

Radiation-induced trismus (RIT) is a common and function-limiting late complication of radiotherapy for head and neck cancers, particularly when the masticatory muscles and temporomandibular joint receive high doses. Despite advances in intensity-modulated radiotherapy, RIT remains a significant survivorship problem, and robust biological biomarkers capable of predicting individual susceptibility are lacking. Heat shock protein 27 (HSP27; HSPB1) is a small heat shock protein that regulates multiple cellular stress responses, including proteostasis, cytoskeletal dynamics, redox homeostasis, apoptosis, and inflammatory signaling. In head and neck malignancies, HSP27 overexpression has been associated with treatment resistance and fibrosis-prone tissue remodeling. Experimental studies further demonstrate that HSP27 promotes transforming growth factor-β-mediated myofibroblast differentiation and extracellular matrix deposition, whereas pharmacologic or genetic inhibition attenuates radiation- or bleomycin-induced pulmonary fibrosis in vivo. Evidence from skeletal muscle biology also indicates that HSP27 modulates muscle integrity, denervation-associated atrophy, inflammatory signaling, and cytoskeletal stability. Although HSP27 has been widely investigated in radiation responses, fibrosis, and skeletal muscle stress adaptation, its potential involvement in the pathogenesis of RIT has not been systematically examined. This review proposes a conceptual framework in which HSP27 functions as an integrative molecular mediator linking radiation-induced oxidative stress, endothelial injury, and fibro-atrophic remodeling within the masticatory apparatus. By integrating current evidence on the epidemiology, dosimetric determinants, imaging correlates, and pathophysiology of RIT with the structural and functional biology of HSP27, this review provides the first tissue-specific synthesis of molecular stress signaling and clinical mechanisms relevant to RIT susceptibility. We further suggest that HSP27 signaling may influence susceptibility to fibro-neuromuscular injury in irradiated masticatory tissues. Given the absence of direct experimental or clinical evidence in this setting, these considerations are derived from mechanistic convergence across related biological systems and should be interpreted as biologically plausible but unproven, with potential implications for future biomarker development and biologically informed prevention strategies. Full article