title: E-cadherin protects primary hepatocyte spheroids from cell death by a caspase-independent mechanism.
abstract: Cultivation of primary hepatocytes as spheroids creates an efficient three-dimensional model system for hepatic studies in vitro and as a cell source for a spheroid reservoir bioartificial liver. The mechanism of spheroid formation is poorly understood, as is an explanation for why normal, anchorage-dependent hepatocytes remain viable and do not undergo detachment-induced apoptosis, known as anoikis, when placed in suspension spheroid culture. The purpose of this study was to investigate the role of E-cadherin, a calcium-dependent cell adhesion molecule, in the formation and maintenance of hepatocyte spheroids. Hepatocyte spheroids were formed by a novel rocker technique and cultured in suspension for up to 24 h. The dependence of spheroid formation on E-cadherin and calcium was established using an E-cadherin blocking antibody and a calcium chelator. We found that inhibiting E-cadherin prevented cell-cell attachment and spheroid formation, and, surprisingly, E-cadherin inhibition led to hepatocyte death through a caspase-independent mechanism. In conclusion, E-cadherin is required for hepatocyte spheroid formation and may be responsible for protecting hepatocytes from a novel form of caspase-independent cell death.
authors.affiliation: Department of Surgery, Division of Transplant Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Luebke-Wheeler
authors.forename: Geir
authors.initials: G
authors.lastname: Nedredal
authors.forename: Le
authors.initials: L
authors.lastname: Yee
authors.forename: Bruce P
authors.initials: BP
authors.lastname: Amiot
authors.forename: Scott L
authors.initials: SL
authors.lastname: Nyberg
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis; D015820:Cadherins / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D020169:Caspases / Q000378:metabolism*; D002448:Cell Adhesion; D002478:Cells, Cultured; D022781:Hepatocytes / Q000166:cytology*; D008297:Male; D011804:Quinolines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018874:Spheroids, Cellular
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D015820:Cadherins; D011804:Quinolines; C468548:quinoline-val-asp(OMe)-CH2-OPH; D020169:Caspases; D002118:Calcium