title: α-5 Laminin Synthesized by Human Pluripotent Stem Cells Promotes Self-Renewal.
abstract: Substrate composition significantly impacts human pluripotent stem cell (hPSC) self-renewal and differentiation, but relatively little is known about the role of endogenously produced extracellular matrix (ECM) components in regulating hPSC fates. Here we identify α-5 laminin as a signature ECM component endogenously synthesized by undifferentiated hPSCs cultured on defined substrates. Inducible shRNA knockdown and Cas9-mediated disruption of the LAMA5 gene dramatically reduced hPSC self-renewal and increased apoptosis without affecting the expression of pluripotency markers. Increased self-renewal and survival was restored to wild-type levels by culturing the LAMA5-deficient cells on exogenous laminin-521. Furthermore, treatment of LAMA5-deficient cells with blebbistatin or a ROCK inhibitor partially restored self-renewal and diminished apoptosis. These results demonstrate that endogenous α-5 laminin promotes hPSC self-renewal in an autocrine and paracrine manner. This finding has implications for understanding how stem cells dynamically regulate their microenvironment to promote self-renewal and provides guidance for efforts to design substrates for stem cell bioprocessing.
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, 1550 Engineering Drive, Madison, WI 53706, USA; Wisconsin Institute for Discovery, University of Wisconsin - Madison, 330 North Orchard Street, Madison, WI 53715, USA.
authors.forename: Alex
authors.initials: A
authors.lastname: Laperle
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin - Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
authors.forename: Cheston
authors.initials: C
authors.lastname: Hsiao
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin - Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Lampe
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, 1550 Engineering Drive, Madison, WI 53706, USA.
authors.forename: Jaime
authors.initials: J
authors.lastname: Mortier
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, 1550 Engineering Drive, Madison, WI 53706, USA; Wisconsin Institute for Discovery, University of Wisconsin - Madison, 330 North Orchard Street, Madison, WI 53715, USA.
authors.forename: Krishanu
authors.initials: K
authors.lastname: Saha
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, 1550 Engineering Drive, Madison, WI 53706, USA; Department of Chemical and Biological Engineering, University of Wisconsin - Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Palecek
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, 1550 Engineering Drive, Madison, WI 53706, USA; Wisconsin Institute for Discovery, University of Wisconsin - Madison, 330 North Orchard Street, Madison, WI 53715, USA. Electronic address: kmasters@wisc.edu.
authors.forename: Kristyn S
authors.initials: KS
authors.lastname: Masters
mesh_terms: D017209:Apoptosis; D002460:Cell Line; D049109:Cell Proliferation; D006801:Humans; D007797:Laminin / Q000235:genetics / Q000378:metabolism*; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism*
chemical_list: D007797:Laminin; C097043:laminin alpha5