Tissue-targeted R-spondin mimetics for liver regeneration

Sci Rep. 2020 Aug 18;10(1):13951. doi: 10.1038/s41598-020-70912-3.

Abstract

R-spondin (RSPO) proteins amplify Wnt signaling and stimulate regeneration in a variety of tissues. To repair tissue in a tissue-specific manner, tissue-targeted RSPO mimetic molecules are desired. Here, we mutated RSPO (RSPO2 F105R/F109A) to eliminate LGR binding while preserving ZNRF3/RNF43 binding and targeted the mutated RSPO to a liver specific receptor, ASGR1. The resulting bi-specific molecule (αASGR1-RSPO2-RA) enhanced Wnt signaling effectively in vitro, and its activity was limited to ASGR1 expressing cells. Systemic administration of αASGR1-RSPO2-RA in mice specifically upregulated Wnt target genes and stimulated cell proliferation in liver but not intestine (which is more responsive to non-targeted RSPO2) in healthy mice, and improved liver function in diseased mice. These results not only suggest that a tissue-specific RSPO mimetic protein can stimulate regeneration in a cell-specific manner, but also provide a blueprint of how a tissue-specific molecule might be constructed for applications in a broader context.

MeSH terms

  • Animals
  • Asialoglycoprotein Receptor / drug effects
  • Asialoglycoprotein Receptor / metabolism
  • Cell Line
  • Cell Proliferation
  • Drug Discovery / methods
  • HEK293 Cells
  • Humans
  • Intercellular Signaling Peptides and Proteins / genetics
  • Intercellular Signaling Peptides and Proteins / metabolism
  • Intercellular Signaling Peptides and Proteins / pharmacology*
  • Liver Regeneration / drug effects*
  • Liver Regeneration / physiology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Receptors, G-Protein-Coupled / metabolism
  • Signal Transduction / drug effects
  • Thrombospondins / metabolism
  • Thrombospondins / therapeutic use
  • Ubiquitin-Protein Ligases / metabolism
  • Wnt Signaling Pathway / drug effects
  • beta Catenin / metabolism

Substances

  • ASGR1 protein, human
  • Asialoglycoprotein Receptor
  • Intercellular Signaling Peptides and Proteins
  • Receptors, G-Protein-Coupled
  • Rspo2 protein, human
  • Thrombospondins
  • beta Catenin
  • Ubiquitin-Protein Ligases