Biology subjects

Kadler, K.

Publications and source records attributed to Kadler, K..

7 recordsLinked to original sources

bioRxiv2025

Macrophages promote collagen deposition through circadian regulation of fibroblasts

Collagen deposition in fibroblasts, the primary collagen-producing cells, is regulated by both macrophages and the circadian rhythm, although how these regulatory processes interact with one another is unknown. Here, we reveal that macrophage-fibroblast interaction enhances collagen deposition which requires a functional circadian rhythm. This response is also dependent on macrophage polarisation status, where M0 (naive) and M1 (pro-inflammatory) macrophages require direct cell-cell contact; whereas M2 (anti-inflammatory) macrophages utilise an additional mechanism through secreted soluble factors that strengthen circadian rhythms and significantly increase collagen deposition in fibroblasts, independent of cell-cell contact. Using mass spectrometry proteomics analysis, we identified PDGFA as a key factor in induction of circadian amplitude in fibroblasts. Crucially, macrophages lacking PDGFA showed diminished ability to modulate fibroblast circadian rhythms and collagen production. Further, in fibroblasts with impaired circadian rhythms, neither macrophages nor macrophage-secreted factors are capable of inducing collagen deposition. These results confirmed that the collagen secretory pathway is also under circadian clock control in lung fibroblasts, and demonstrated that macrophages influence collagen deposition via circadian clock mediated mechanisms. In conclusion, our findings highlight M2-derived PDGFA as a key macrophage-derived factor in extracellular matrix remodelling.

cell biology↗

bioRxiv2022

Mutual inhibition of airway epithelial responses supports viral and fungal co-pathogenesis during coinfection

Awareness that fungal coinfection complicates viral respiratory infections causing worse disease outcome has recently emerged. The environmental fungus Aspergillus fumigatus (Af) has been reported as the main driver of fungal coinfection in patients suffering from viral infections caused by Cytomegalovirus, Influenza or more recently SARS-CoV2. The airway epithelium is the first common point of contact between inhaled pathogens and the host. Aberrant airway epithelial cell (AEC) responses against fungal challenge have been described in patients susceptible to aspergillosis. Therefore, it is likely that a dysregulation of AEC responses during fungal-viral coinfection represents a potent driver for the development of fungal disease. Here we used an in vitro model of Af-viral infection of AECs to determine outcomes of spore internalisation, killing and viral replication during coinfection. Our data indicate that viral stimulation, while boosting Af uptake by AECs, limits Af spore killing by those cells, favouring fungal persistence and growth. Type I viral-induced interferon release was significantly decreased in the presence of Af hyphal forms suggesting a possible role of Af secreted factors in modulating viral pathogenicity. We next explored the impact of Af challenge in SARS-CoV2 replication within airway epithelial cells using nano-luciferase as a measure of viral replication. We found that Af increased SARS-CoV2 pathogenicity in a strain-dependent manner. Collectively, our findings demonstrate a mutual inhibition of antifungal and antiviral AEC responses during Af-viral coinfection and also suggest that some fungal factors might be key regulators of co-pathogenicity during in lung infection.

microbiology↗

bioRxiv2022

De-tensioning of collagen fibers optimizes endometrial receptivity and improves the rate of embryo implantation

Successful embryo implantation within the uterine wall requires intricate endometrial remodeling. Impaired endometrial receptivity, a common cause of infertility, often results from ineffective remodeling processes. Here, we demonstrate that a single dose of human collagenase-1 administered into the mouse uterus enhances embryo implantation rates. Mechanistically, collagenase-1 induces remodeling of the endometrial extracellular matrix (ECM), leading to the degradation of collagen fibers and proteoglycans. This process releases matrix-bound bioactive factors, such as VEGF, which facilitates local vascular permeability and angiogenesis. Furthermore, collagenase-1 treatment increases NK cell infiltration and elevates levels of the cytokine LIF, a key factor in embryo implantation. Remarkably, the overall structural integrity of the uterine tissue remains uncompromised, even in the presence of reduced tension in endometrial collagen fibers. To assess pre-clinical potential, in-uteri application of collagenase-1 successfully rescued implantation in mouse models subjected to heat stress and embryo transfer, conditions known for their adverse impact on implantation rates. Importantly, ex-vivo exposure of human uterine tissue to collagenase-1 induced collagen de-tensioning and the release of VEGF, demonstrating similar processes observed in the mouse settings, and the potential relevance of this treatment to human conditions. Our findings underscore the immense clinical potential and feasibility of collagenase treatment to enhance uterine receptivity for embryo implantation, offering a controlled and minimally invasive intervention. This innovative approach not only demonstrates the potential to enhance efficiency in livestock breeding but, more importantly, signifies a substantial promise in supporting medical interventions for human reproduction in clinical settings.

biochemistry↗

bioRxiv2020

IL-13 deficiency exacerbates lung damage and impairs epithelial-derived type 2 molecules during nematode infection

IL-13 plays a key role during protective type 2 immune responses at mucosal sites, such as during infection with nematodes. However, dysregulation of IL-13 can also contribute to the pathogenesis of atopic and fibrotic diseases such as allergic asthma. Matrix remodelling is an important component of repair processes in the lung but also a hallmark of chronic conditions involving fibrosis. Hence, understanding the role of IL-13 in tissue remodelling has important clinical implications. Since IL-13 shares receptors and signalling pathways with IL-4, disentangling the relative contributions of these type 2 cytokines has been challenging. Additionally, little is known about the singular role of IL-13 following acute tissue injury. In this study, we used Nippostrongylus brasiliensis infection as a model of acute lung tissue damage comparing responses between WT and IL-13-deficient mice, in which IL-4 signalling is intact. Importantly, we found that IL-13 played a critical role in limiting tissue injury and haemorrhaging in the lung following infection. Through proteomic and transcriptomic profiling, we identified IL-13-dependent changes in matrix and associated regulators. We further showed that IL-13 is required for the induction of epithelial-derived type 2 effector molecules such as RELM- and surfactant protein D. Pathway analyses predicted that IL-13 was heavily involved in the induction of cellular stress responses and regulation of lung epithelial cell differentiation by suppression of Foxa2 pathways. Thus, we propose that IL-13 has tissue-protective functions during lung injury and regulates epithelial cell responses during type 2 immunity in this acute setting.

immunology↗

bioRxiv2020

Dynamic protein quantification (DyProQ) of procollagen-I by CRISPR-Cas9 NanoLucIferase tagging

The ability to quantitate a protein of interest temporally and spatially at subcellular resolution in living cells would generate new opportunities for research and drug discovery but remains a major technical challenge. Here, we describe dynamic protein quantitation (DyProQ) which is effective across microscopy and multiwell platforms. Using collagen as a test protein, CRISPR-Cas9-mediated introduction of nluc (encoding NanoLuciferase, NLuc) into the Col1a2 locus enabled simplification and miniaturisation of procollagen-I (PC-I) quantitation. We robustly assessed extracellular, intracellular, and subcellular PC-I levels, by correlating to known concentrations of recombinant NLuc in the presence of substrate. Loss of collagen causes tissue degeneration whereas excess collagen results in fibrosis (often with poor-outcome) and is evident in aggressive cancers; however, treatment options are extremely limited. Using collagen-DyProQ, we screened a library of 1,971 FDA-approved compounds and identified 10 candidates for repurposing in the treatment of fibrotic and 7 for degenerative diseases.

cell biology↗

bioRxiv2020

Material-Driven Fibronectin Assembly Rescues Matrix Defects due to Mutations in Collagen IV in Fibroblasts

Basement membranes (BMs) provide structural support to tissues and influence cell signaling. Mutations in COL4A1/COL4A2, a major BM component, cause eye, kidney and cerebrovascular disease, including stroke. Common variants in these genes are risk factors for intracerebral hemorrhage in the general population. However, the contribution of the matrix to the disease mechanism(s) and its effects on the biology of cells harboring a collagen IV mutation remain poorly understood. To shed light on this, we engineered controlled microenvironments using polymer biointerfaces coated with ECM proteins laminin or fibronectin (FN), to investigate the cellular phenotype of primary fibroblasts harboring a COL4A2+/G702D mutation. FN nanonetworks assembled on poly(ethyl acrylate) (PEA) induced increased deposition and assembly of collagen IV in COL4A2+/G702D cells, which was associated with reduced ER size and enhanced levels of protein chaperones such as BIP, suggesting increased protein folding capacity of cells. FN nanonetworks on PEA also partially rescued the reduced stiffness of the deposited matrix and cells, and enhanced cell adhesion through {beta}1-mediated signaling and actin-myosin contractility, effectively rescuing some of the cellular phenotypes associated with COL4A1/4A2 mutations. Collectively, these results suggest that biomaterials are able to shape the matrix and cellular phenotype of the COL4A2+/G702D mutation in patient-derived cells.

bioengineering↗

bioRxiv2018

Collagen assembly and turnover imaged with a CRISPR-Cas9 engineered Dendra2 tag

Electron microscopy has been the \"gold standard\" for studying collagen networks but dynamic information on how cells synthesise the networks has been lacking. Live imaging methods have been unable to distinguish newly-synthesised fibrils from pre-existing fibrils and intracellular collagen. Here, we tagged endogenous collagen-I using CRISPR-Cas9 with photoswitchable Dendra2 and demonstrate live cells synthesising, migrating on, and interacting with, collagen fibrils. This strategy is applicable for other long half-life proteins.

cell biology↗