title: Integrin-linked kinase production prevents anoikis in human mesenchymal stem cells.
abstract: Human mesenchymal stem cells (hMSCs) were infected with an adenovirus expressing integrin-linked kinase (ILK) to understand the role of cell-ECM signal transduction cascades in suppressing anoikis. Survivability of ILK-infected hMSCs encapsulated in poly(ethylene glycol) (PEG) hydrogels, an anoikis-inducing environment, was sustained at 90% over 7 weeks, and survival was attributed to increased protein kinase B (PKB/Akt) activation. hMSCs encapsulated in RGD-modified hydrogels induced an upregulation in ILK production, PKB/Akt activation, and subsequent survival to the same extent of ILK-infected, encapsulated hMSCs. As negative controls, encapsulated hMSCs were infected with cyclization recombinase (a protein not associated with cell survival)-expressing virus, and uninfected hMSCs exhibited very little ILK production, PKB/Akt activation, and survival ( approximately 55% after 7 weeks). As a measure of cell-matrix interactions, vinculin was also quantified for the encapsulated hMSCs and found to be 30-fold greater for cells encapsulated in RGD-modified hydrogels and fivefold greater for ILK-infected hMSCs than controls, indicating that cell-material interactions are inducing the cell survivability of hMSCs encapsulated in RGD-modified hydrogels. In sum, ILK infection can support cell survival in the absence of matrix interactions and enable fundamental studies of three-dimensional cell function in response to extrinsic signals, independently of matrix-ligand interactions.
authors.affiliation: Department of Chemical and Biological Engineering, University of Colorado, 424 UCB ECCH 111, Boulder, Colorado 80309, USA.
authors.forename: Danielle S W
authors.initials: DS
authors.lastname: Benoit
authors.forename: Margaret C
authors.initials: MC
authors.lastname: Tripodi
authors.forename: James O
authors.initials: JO
authors.lastname: Blanchette
authors.forename: Steve J
authors.initials: SJ
authors.lastname: Langer
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Leinwand
authors.forename: Kristi S
authors.initials: KS
authors.lastname: Anseth
mesh_terms: D023102:Anoikis / Q000187:drug effects / Q000502:physiology*; D001672:Biocompatible Materials; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D020100:Hydrogels; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000201:enzymology* / Q000378:metabolism; D009842:Oligopeptides / Q000494:pharmacology; D011092:Polyethylene Glycols; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis* / Q000235:genetics; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D015398:Signal Transduction; D014162:Transfection; D016596:Vinculin / Q000378:metabolism; D000099200:Scaffold Protein ILK
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D009842:Oligopeptides; D011092:Polyethylene Glycols; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D011994:Recombinant Proteins; D016596:Vinculin; D000099200:Scaffold Protein ILK; C047981:arginyl-glycyl-aspartic acid