Regulation of epithelial-mesenchymal cell-cell partners by complexes of paracrine signals and sulfated oligosaccharides.

Abstract

Complexes of paracrine signals and synthesized, sulfated oligosaccharides regulate expansion and/or differentiation of human epithelial-mesenchymal cell-cell partners with lineage-stage-specific distinctions exemplified in mature hepatocytes versus organoids of stem cells. Of a bank of 53 synthesized heparan sulfate-(HS)-oligosaccharides, 28 formed triggering complexes with selected paracrine signals. Of these, the 12-mer oligosaccharides proved representative for the biological effects of a specific chain chemistry. Optimized conditions for responses to complexes are:(1) A trigger consisting of a paracrine signal bound tightly to a sulfated oligosaccharide; (2) Biologically active sulfated oligosaccharides are of minimum size of 10-12-mers and with ones up to 18-mers giving similar but enhanced responses; (3) Full cell polarization. Responses are not observed at all or not observed fully in cells in two-dimensional formats even when on complex matrix substrata; (4) Epithelial-mesenchymal cell-cell signaling; (5) Serum-free, wholly defined medium tailored to the cells' maturational lineage stage; (6) Responses are predictable by a tell, the ability of a complex to trigger significant changes in sizes of cell nuclei within ∼18 hours. The complexes offer nuanced regulatory controls of growth and differentiation of organs and tissues. Representative triggering complexes [HS-oligosaccharide + paracrine signal] include ones regulating: Self-renewal: fibroblast growth factor-2 (FGF2) bound to an HS-oligosaccharide containing [NS2S] or WNT3A bound to [NS2S6S3S]. Hypertrophy: vascular epithelial growth factor-A (VEGF-A) bound to an HS-oligosaccharidecontaining [NS2S6S3S or NS2S6S]. Expansion in parallel with differentiation: various complexes with a paracrine signal and an oligosaccharide containing [NS2S6S3S]; representative paracrine signals include FGF2, hepatocyte growth factor (HGF), and others. Newly prepared, synthesized chondroitin sulfate-(CS)-oligosaccharides also form triggering complexes with biological responses requiring similar conditions as those for HS-oligosaccharides. Ongoing research efforts are surveying the specific biological responses to particular complexes of CS-oligosaccharides and paracrine signals.