2. Academic Validation
  3. Defining the mechanism of galectin-3-mediated TGF-β1 activation and its role in lung fibrosis

Defining the mechanism of galectin-3-mediated TGF-β1 activation and its role in lung fibrosis

  • J Biol Chem. 2024 Jun;300(6):107300. doi: 10.1016/j.jbc.2024.107300.
Jessica F Calver 1,  Nimesh R Parmar 2,  Gemma Harris 3,  Ryan M Lithgo 4,  Panayiota Stylianou 5,  Fredrik R Zetterberg 6,  Bibek Gooptu 5,  Alison C Mackinnon 7,  Stephen B Carr 8,  Lee A Borthwick 9,  David J Scott 10,  Iain D Stewart 11,  Robert J Slack 12,  R Gisli Jenkins 11,  Alison E John 13
Affiliations

Affiliations

  • 1 School of Medicine, University of Nottingham, Nottingham, United Kingdom; Stevenage Bioscience Catalyst, Galecto Biotech AB, Stevenage, United Kingdom.
  • 2 School of Medicine, University of Nottingham, Nottingham, United Kingdom; Roche Products Limited, Welwyn Garden City, Hertfordshire, United Kingdom.
  • 3 Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, Oxfordshire, United Kingdom.
  • 4 Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, Oxfordshire, United Kingdom; School of Biosciences, University of Nottingham, Loughborough, Leicestershire, United Kingdom; Membrane Protein Laboratory, Diamond Light Source, Rutherford Appleton Laboratory, Didcot, Oxfordshire, United Kingdom; Diamond Light Source, Diamond House, Rutherford Appleton Laboratories, Didcot, Oxfordshire, United Kingdom.
  • 5 Institute for Lung Health, NIHR Leicester Respiratory Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom; Leicester Institute for Structural and Chemical Biology, Henry Wellcome Building, University of Leicester, Leicester, United Kingdom.
  • 6 Galecto Biotech AB, Sahlgrenska Science Park, Gothenburg, Sweden.
  • 7 Galecto Biotech AB, Nine Edinburgh BioQuarter, Edinburgh, United Kingdom.
  • 8 Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, Oxfordshire, United Kingdom; Department of Chemistry, University of Oxford, Oxford, Oxfordshire, United Kingdom.
  • 9 Fibrofind Ltd, Newcastle upon Tyne, United Kingdom; Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom.
  • 10 Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, Oxfordshire, United Kingdom; School of Biosciences, University of Nottingham, Loughborough, Leicestershire, United Kingdom.
  • 11 National Heart and Lung Institute, Imperial College London, London, United Kingdom.
  • 12 Stevenage Bioscience Catalyst, Galecto Biotech AB, Stevenage, United Kingdom.
  • 13 National Heart and Lung Institute, Imperial College London, London, United Kingdom. Electronic address: [email protected].
PMID: 38641066 DOI: 10.1016/j.jbc.2024.107300
Abstract

Integrin-mediated activation of the profibrotic mediator transforming growth factor-β1 (TGF-β1), plays a critical role in idiopathic pulmonary fibrosis (IPF) pathogenesis. Galectin-3 is believed to contribute to the pathological wound healing seen in IPF, although its mechanism of action is not precisely defined. We hypothesized that Galectin-3 potentiates TGF-β1 activation and/or signaling in the lung to promote fibrogenesis. We show that Galectin-3 induces TGF-β1 activation in human lung fibroblasts (HLFs) and specifically that extracellular Galectin-3 promotes oleoyl-L-α-lysophosphatidic acid sodium salt-induced integrin-mediated TGF-β1 activation. Surface plasmon resonance analysis confirmed that Galectin-3 binds to αv integrins, αvβ1, αvβ5, and αvβ6, and to the TGFβRII subunit in a glycosylation-dependent manner. This binding is heterogeneous and not a 1:1 binding stoichiometry. Binding interactions were blocked by small molecule inhibitors of Galectin-3, which target the carbohydrate recognition domain. Galectin-3 binding to β1 Integrin was validated in vitro by coimmunoprecipitation in HLFs. Proximity ligation assays indicated that Galectin-3 and β1 Integrin colocalize closely (≤40 nm) on the cell surface and that colocalization is increased by TGF-β1 treatment and blocked by Galectin-3 inhibitors. In the absence of TGF-β1 stimulation, colocalization was detectable only in HLFs from IPF patients, suggesting the proteins are inherently more closely associated in the disease state. Galectin-3 Inhibitor treatment of precision cut lung slices from IPF patients' reduced Col1a1, TIMP1, and hyaluronan secretion to a similar degree as TGF-β type I receptor inhibitor. These data suggest that Galectin-3 promotes TGF-β1 signaling and may induce fibrogenesis by interacting directly with components of the TGF-β1 signaling cascade.

Keywords

fibroblast; galectin; integrin; pulmonary fibrosis; transforming growth factor beta (TGF-β).

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