title: Inhibition of apoptosis in human induced pluripotent stem cells during expansion in a defined culture using angiopoietin-1 derived peptide QHREDGS.
abstract: Adhesion molecule signaling is critical to human pluripotent stem cell (hPSC) survival, self-renewal, and differentiation. Thus, hPSCs are grown as clumps of cells on feeder cell layers or poorly defined extracellular matrices such as Matrigel. We sought to define a small molecule that would initiate adhesion-based signaling to serve as a basis for a defined substrate for hPSC culture. Soluble angiopoeitin-1 (Ang-1)-derived peptide QHREDGS added to defined serum-free media increased hPSC colony cell number and size during long- and short-term culture when grown on feeder cell layers or Matrigel, i.e. on standard substrates, without affecting hPSC morphology, growth rate or the ability to differentiate into multiple lineages both in vitro and in vivo. Importantly, QHREDGS treatment decreased hPSC apoptosis during routine passaging and single-cell dissociation. Mechanistically, the interaction of QHREDGS with β1-integrins increased expression of integrin-linked kinase (ILK), increased expression and activation of extracellular signal-regulated kinases 1/2 (ERK1/2), and decreased caspase-3/7 activity. QHREDGS immobilization to polyethylene glycol hydrogels significantly increased cell adhesion in a dose-dependent manner. We propose QHREDGS as a small molecule inhibitor of hPSC apoptosis and the basis of an affordable defined substrate for hPSC maintenance.
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada; The Heart and Stroke/Richard Lewar Centre of Excellence, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
authors.forename: Lan T H
authors.initials: LT
authors.lastname: Dang
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada.
authors.forename: Nicole T
authors.initials: NT
authors.lastname: Feric
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada.
authors.forename: Carol
authors.initials: C
authors.lastname: Laschinger
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada; Sprott Centre for Stem Cell Research, The Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada; Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada.
authors.forename: Wing Y
authors.initials: WY
authors.lastname: Chang
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada.
authors.forename: Boyang
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors.forename: Geoffrey A
authors.initials: GA
authors.lastname: Wood
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada; Sprott Centre for Stem Cell Research, The Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada; Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada.
authors.forename: William L
authors.initials: WL
authors.lastname: Stanford
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada; The Heart and Stroke/Richard Lewar Centre of Excellence, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada. Electronic address: m.radisic@utoronto.ca.
authors.forename: Milica
authors.initials: M
authors.lastname: Radisic
mesh_terms: D042683:Angiopoietin-1 / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D002452:Cell Count; D018929:Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D061252:Feeder Cells / Q000166:cytology / Q000187:drug effects; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D019012:Integrin beta1 / Q000378:metabolism; D051379:Mice; D010455:Peptides / Q000494:pharmacology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D013997:Time Factors; D000099200:Scaffold Protein ILK
chemical_list: D042683:Angiopoietin-1; D020169:Caspases; D048049:Extracellular Signal-Regulated MAP Kinases; D019012:Integrin beta1; D010455:Peptides; D017346:Protein Serine-Threonine Kinases; D000099200:Scaffold Protein ILK
keywords: Adhesion; Angiopoietin-1; Apoptosis; Human pluripotent stem cells; Integrins; QHREDGS