title: Phosphatidylcholine metabolism and choline kinase in human osteoblasts.
abstract: There is a paucity of information about phosphatidylcholine (PC) biosynthesis in bone formation. Thus, we characterized PC metabolism in both primary human osteoblasts (HOB) and human osteosarcoma MG-63 cells. Our results show that the CDP-choline pathway is the only de novo route for PC biosynthesis in both HOB and MG-63 cells. Both CK activity and CKα expression in MG-63 cells were significantly higher than those in HOB cells. Silencing of CKα in MG-63 cells had no significant effect on PC concentration but decreased the amount of phosphocholine by approximately 80%. The silencing of CKα also reduced cell proliferation. Moreover, pharmacological inhibition of CK activity impaired the mineralization capacity of MG-63 cells. Our data suggest that CK and its product phosphocholine are required for the normal growth and mineralization of MG-63 cells.
authors.affiliation: The Molecular and Cell Biology of Lipids, The Department of Biochemistry, The Alberta Diabetes Institute and Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta T6G 2S2 Canada.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Li
authors.affiliation: The Molecular and Cell Biology of Lipids, The Department of Biochemistry, The Alberta Diabetes Institute and Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta T6G 2S2 Canada.
authors.forename: Gengshu
authors.initials: G
authors.lastname: Wu
authors.affiliation: The Molecular and Cell Biology of Lipids, The Department of Biochemistry, The Alberta Diabetes Institute and Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta T6G 2S2 Canada.
authors.forename: Jelske N
authors.initials: JN
authors.lastname: van der Veen
authors.affiliation: The Molecular and Cell Biology of Lipids, The Department of Biochemistry, The Alberta Diabetes Institute and Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta T6G 2S2 Canada.
authors.forename: Martin
authors.initials: M
authors.lastname: Hermansson
authors.affiliation: The Molecular and Cell Biology of Lipids, The Department of Biochemistry, The Alberta Diabetes Institute and Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta T6G 2S2 Canada. Electronic address: dennis.vance@ualberta.ca.
authors.forename: Dennis E
authors.initials: DE
authors.lastname: Vance
mesh_terms: D002113:Calcification, Physiologic / Q000235:genetics*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002797:Choline Kinase / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D006426:Hemicholinium 3 / Q000494:pharmacology; D006801:Humans; D050356:Lipid Metabolism / Q000235:genetics; D010006:Osteoblasts / Q000201:enzymology; D010012:Osteogenesis / Q000235:genetics*; D010713:Phosphatidylcholines / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering
chemical_list: D010713:Phosphatidylcholines; D034741:RNA, Small Interfering; D006426:Hemicholinium 3; D002797:Choline Kinase
keywords: Choline kinase; MG-63 cells; Mineralization; Phosphatidylcholine; Phosphocholine; Proliferation