Biology subjects

Elfari, L.

Publications and source records attributed to Elfari, L..

2 recordsLinked to original sources

bioRxiv2025

Mechanical signalling through collagen I regulates cholangiocyte specification and tubulogenesis during liver development

Cholangiocyte dysfunction accounts for a third of liver transplantations, access to which is limited by a shortage of healthy donor organs. A promising alternative is the therapeutic use of human induced pluripotent stem cell (hiPSC)-derived cholangiocytes. However, the use of hiPSCs is impeded by a lack of knowledge regarding intrahepatic cholangiocyte development, limiting the generation of fully functional cells. In this study, we generate hiPSC-derived tubular cholangiocytes using an approach based in synthetic hydrogels. These hydrogels exert control over stiffness and extracellular matrix (ECM) composition and stability, allowing us to address a critical gap in understanding cholangiocyte development. Our findings reveal that stable collagen I functionalisation, particularly on a soft substrate, enhances cholangiocyte differentiation, largely irrespective of substrate stiffness. Furthermore, high collagen I stability on a soft substrate suppresses hepatic identity whilst promoting biliary identity and duct morphogenesis. Our findings highlight the importance of collagen I mechanical signalling in regulating hepatoblast fate determination. Overall, we propose a mechanism by which the ECM modulates cholangiocyte and bile duct development and present a scalable platform for future clinical applications in the understanding and treatment of cholangiopathies.

developmental biology↗

bioRxiv2021

Architecture of cell-cell junctions in situ reveals a mechanism for bacterial biofilm inhibition

Many bacteria, including the major human pathogen Pseudomonas aeruginosa, are naturally found in multicellular, antibiotic-tolerant biofilm communities, where cells are embedded in an extracellular matrix of polymeric molecules. Cell-cell interactions within P. aeruginosa biofilms are mediated by CdrA, a large, membrane-associated adhesin present in the extracellular matrix of biofilms, regulated by the cytoplasmic concentration of cyclic diguanylate. Here, using electron cryotomography of focused-ion beam milled specimens, we report the architecture of CdrA molecules in the extracellular matrix of P. aeruginosa biofilms at intact cell-cell junctions. Combining our in situ observations at cell-cell junctions with biochemistry, native mass spectrometry and cellular imaging, we demonstrate that CdrA forms an extended structure that projects from the outer membrane to tether cells together via polysaccharide binding partners. We go on to show the functional importance of CdrA using custom single-domain antibody (nanobody) binders. Nanobodies targeting the tip of functional cell-surface CdrA molecules could be used to inhibit bacterial biofilm formation or disrupt pre-existing biofilms in conjunction with bactericidal antibiotics. These results reveal a functional mechanism for cell-cell interactions within bacterial biofilms and highlight the promise of using inhibitors targeting biofilm cell-cell junctions to prevent or treat problematic, chronic bacterial infections.

microbiology↗