title: Andrographolide activates the canonical Wnt signalling pathway by a mechanism that implicates the non-ATP competitive inhibition of GSK-3β: autoregulation of GSK-3β in vivo.
abstract: Wnt/β-catenin signalling is an important pathway that regulates multiple biological processes, including cell adhesion and determination of cell fate during animal development; in the adult nervous system it regulates the structure and function of synapses. Wnt-signalling dysfunction is associated with several neurodegenerative diseases such as schizophrenia and Alzheimer's disease. The use of natural compounds is an interesting strategy in the search for drugs with the therapeutic potential to activate this signalling pathway. In the present study, we report that andrographolide (ANDRO), a component of Andrographis paniculata, is a potent activator of Wnt signalling. Our results indicate that ANDRO activates this pathway, inducing the transcription of Wnt target genes by a mechanism that bypasses Wnt ligand binding to its receptor. In vitro kinase assays demonstrate that ANDRO inhibits glycogen synthase kinase (GSK)-3β by a non-ATP-competitive, substrate-competitive mode of action. In silico analyses suggest that ANDRO interacts with the substrate-binding site of GSK-3β. Finally, we demonstrated that the increase seen in the levels of GSK-3β phosphorylated at Ser⁹ is the result of an autoregulatory mechanism of the kinase in vivo, although not through activation of protein phosphatase type 1. Our results suggest that ANDRO could be used as a potential therapeutic drug for disorders caused by Wnt-signalling dysfunction such as neurodegenerative diseases.
authors.affiliation: *Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Cheril
authors.initials: C
authors.lastname: Tapia-Rojas
authors.affiliation: †Departamento de Genética Molecular y Microbiología; Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schüller
authors.affiliation: *Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Carolina B
authors.initials: CB
authors.lastname: Lindsay
authors.affiliation: *Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Roxana C
authors.initials: RC
authors.lastname: Ureta
authors.affiliation: *Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Cristóbal
authors.initials: C
authors.lastname: Mejías-Reyes
authors.affiliation: §Instituto de Farmacología y Morfofisiología, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: Juan
authors.initials: J
authors.lastname: Hancke
authors.affiliation: †Departamento de Genética Molecular y Microbiología; Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Francisco
authors.initials: F
authors.lastname: Melo
authors.affiliation: *Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Nibaldo C
authors.initials: NC
authors.lastname: Inestrosa
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D020134:Catalytic Domain; D002478:Cells, Cultured; D004224:Diterpenes / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D051379:Mice; D062105:Molecular Docking Simulation; D015394:Molecular Structure; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D018697:Nootropic Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D051381:Rats; D012694:Serine / Q000737:chemistry / Q000378:metabolism; D060449:Wnt Signaling Pathway / Q000187:drug effects*
chemical_list: D004224:Diterpenes; D018697:Nootropic Agents; D047428:Protein Kinase Inhibitors; C030419:andrographolide; D012694:Serine; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3