Loxl2

Cells were fixed with 4% paraformaldehyde followed by permeabilisation and staining with primary antibodies for LOXL2 (1:100, R&D Systems), PLOD2 (1:100, Proteintech) and tetramethylrhodamine (TRITC)-conjugated Phalloidin (1:1000, Millipore UK Limited, Watford, UK). The secondary antibodies used were Alexafluor 488 and 647 (1:1000, BioLegend UK Ltd, London, UK). Cell nuclei were counterstained with 4',6-Diamidino-2-Phenylindole, Dihydrochloride (DAPI) (1:1000, Millipore UK Limited, Watford, UK). Cells were imaged using an inverted confocal microscope (Leica TCS-SP5 Confocal Microscope, Leica Microsystems).

Fibroblasts were lysed using 2 x Laemmli SDS sample buffer or urea buffer (8 M Urea, 1 M Thiourea, 0.5% CHAPS, 50 mM DTT, and 24 mM Spermine). Western blotting of cellular lysates was performed for β-actin (1:100.000, Sigma-Aldrich, Poole, UK), LOXL2 (1:1000, R&D Systems, Abingdon, UK), HIF1α (1:1000, BD Biosciences, Wokingham, UK), FIH (1:200, mouse monoclonal 162 C) (Wang et al., 2018 (link)), β-tubulin (1:1000, Cell Signaling Technology, London, UK), HIF1 β (1:1000, Cell Signaling Technology), p-Smad2/3 (1:1000, Cell Signaling Technology), p-ERK (1:1000, Cell Signaling Technology), active β-catenin (1:1000, Cell Signaling Technology). Immunodetected proteins were identified using the enhanced chemiluminescence system (Clarity Western Blotting ECL Substrate, Bio-Rad Laboratories Ltd, Watford, UK) or Odyssey imaging system (LI-COR), and evaluated by ImageJ 1.42q software (National Institutes of Health).

Levels of fibrosis biomarkers were measured on EDTA plasma by ELISA or multiplex assay using commercially available kits. HA (Echelon Biosciences, Salt Lake City, UT), LOXL2 (R&D Systems, Minneapolis, Minnesota), and CICP and CIC C1Q (Quidel, San Diego, CA) were measured by ELISA. PAI-1, PCSK9, TGF-ß₁-₃, MMP-2, MMP-9, TIMP-1, CXCL4, Chi3L1 (all R&D Systems, Minneapolis, MN) were measured using Luminex xMAP technology. All analytes except LOXL2 were measured according to the manufacturers' instructions. For LOXL2, the ELISA plates were coated overnight with capture antibody at room temperature. The plate was blocked with reagent diluent 1 (R&D Systems, Minneapolis, MN) for 1 hour and washed. Plasma was diluted 1:10 in PBS-Tween 10 and added to the plate. After incubating for 2 hours at 37° C and washing, detection antibody was added for 2 hours at 37° C. The plate was washed, streptavidin was added and the plate was incubated for 20 minutes at room temperature. After washing, TMB was added (Sigma-Aldrich Corp., St. Louis, MO), the plate was incubated for 20 minutes at room temperature, and sulfuric acid was added to stop the reaction. The plate was read at 450 nm.