Karsdal, M. A. | bioRxiv Science

bioRxiv2026

Circulating biomarkers reflecting type III, IV and VI collagen remodeling are present in lung tissue of patients with pulmonary fibrosis and non-fibrotic controls

BackgroundThe extracellular matrix (ECM) is a dynamic network that provides structural support and maintains tissue homeostasis. Collagens are the main structural components of the ECM, occupying distinct tissue compartments and serving specialized roles. Dysregulated ECM remodeling involves an imbalance between collagen production and degradation, generating neoepitope-specific fragments that can be released into circulation. Serological measurements of these fragments can be used as biomarkers of disease and have been associated with progression and mortality in different fibrotic diseases, including pulmonary fibrosis (PF). This study aimed to investigate whether these systemic biomarkers originate from human lung tissue in patients with PF and non-fibrotic controls. MethodsLung tissue was collected from patients with PF (n = 21) and non-fibrotic controls (n = 21) and processed in parallel as formalin-fixed paraffin-embedded or snap-frozen samples. Serum samples were collected from patients with PF and healthy controls (n = 21). Neoepitope-specific biomarkers reflecting type III, IV, and VI collagen production (PRO-C3, PRO-C4, and PRO-C6) and degradation (C3M, C4M, C4Ma3, and C6M) were quantified in serum and proteolytically degraded lung tissue, and their spatial distribution was assessed by immunohistochemistry in lung tissue sections. ResultsAll collagen remodeling biomarkers were significantly increased in serum of patients with PF compared with healthy controls (PRO-C3: p = 0.0006, all others: p < 0.0001). Collagen degradation fragments (C3M, C4M, and C6M) could be generated and released from both non-fibrotic and fibrotic human lung tissue following proteolytic cleavage with pepsin, collagenase, and/or MMP-9. All biomarkers were detected in lung tissue by immunohistochemical staining, with widespread distribution of type III and IV collagen fragments, whereas type VI collagen (PRO-C6) production showed a more compartment-specific pattern. ConclusionsThese findings demonstrated that neoepitope-specific collagen remodeling biomarkers, usually detected in circulation, are present and can be released from human lung tissue. Their spatial distribution suggests that ECM remodeling is heterogeneous and differs according to collagen type and distinct tissue compartments. Collectively, our findings support the use of collagen remodeling biomarkers as tools to assess ECM remodeling in pulmonary disease.

molecular biology↗

bioRxiv2025

Tankyrase inhibition demonstrates anti-fibrotic effects in preclinical pulmonary fibrosis models

BackgroundIdiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease with limited treatment options. Although transforming growth factor beta 1 (TGFB1, TGF{beta}) is a key driver of fibrosis, additional signaling pathways, including wingless-type mammary tumor virus integration site (WNT)/{beta}-catenin and yes-associated protein 1 (YAP), contribute to IPF pathogenesis. Clinical data indicate that inhibition of TGF{beta} alone provides limited efficacy or is associated with toxicity, underscoring the need for alternative therapeutic approaches. Tankyrase (TNKS) 1 and 2 are post-translational regulators of WNT/{beta}-catenin and YAP signaling and therefore represent promising antifibrotic targets. OM-153, a potent and selective TNKS inhibitor, exhibits pharmacological properties suitable for preclinical development in IPF. MethodsPrimary normal human lung fibroblasts (NHLF), Scar-in-a-Jar assays, lung-on-a-chip models, and precision-cut lung slices (PCLS) from non-pulmonary fibrosis (non-PF) tissue were stimulated with an IPF-relevant cytokine cocktail (IPF-RC) designed to accurately recapitulate the pro-fibrotic environment and compared to TGF{beta}. These models, with bleomycin-challenged mice and PCLS from end-stage pulmonary fibrosis (PF) patients, were treated with OM-153. Fibrosis markers, extracellular matrix (ECM) components, and signaling pathway-specific gene expression or protein markers were assessed by real-time qRT-PCR, RNA sequencing, immunoblotting, ELISA, and immunofluorescence. ResultsOM-153 stabilized the direct TNKS targets axin 1 (AXIN1) and angiomotin-like 1 (AMOTL1), suppressed WNT/{beta}-catenin and YAP signaling. In parallel, it reduced profibrotic ECM expression across in vitro, in vivo, and ex vivo IPF models. ConclusionsSelective TNKS inhibition by OM-153 demonstrates broad antifibrotic activity in multiple preclinical models, supporting further development as a potential disease-modifying strategy for IPF. Shareable abstractOur findings show that the potent and selective TNKS inhibitor OM-153 suppresses WNT/{beta}-catenin and YAP signaling, reducing pro-fibrotic ECM expression in preclinical IPF models, supporting TNKS inhibition as a novel antifibrotic strategy.

cell biology↗