title: Selective lysis of early embryonic cells by the alternative pathway of complement--a possible mechanism for programmed cell death in embryogenesis.
abstract: Early embryonic cells and early mouse embryos were shown to activate the alternative pathway of complement, and to be highly sensitive to complement-mediated cytolysis (Kircheis et al, In Vivo 9: 85-98, 1995). Under further development embryonic cells become resistant. The induction of resistance to the alternative pathway of complement correlates with: a) altered splicing of Cr2-transcript and b) changes in the acidic glycolipids under differentiation. Early embryonic cells have low amounts of sialic acid-containing glycolipids or express mainly GM3. The induction of differentiation changes the glycolipid pattern leading to an increase in membrane-bound sialic acid. The importance of membrane-bound sialic acid in the restriction of complement activation is demonstrated by increased sensitivity to complement after pre-treatment of cells with neuraminidase. The results indicate that there is target-specific lysis of early embryonic cells by the alternative pathway of complement. Early embryonic cells activate the alternative pathway of complement by expressing activators and low levels of membrane-bound sialic acid. Induction of differentiation changes the glycolipid pattern, leading to an increase in membrane-bound sialic acid sufficient to restrict complement-activation on the cell surface.
authors.affiliation: Biotechnology Research Center, Teikyo University, Kawasaki, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Kircheis
authors.forename: L
authors.initials: L
authors.lastname: Kircheis
authors.forename: H
authors.initials: H
authors.lastname: Oshima
authors.forename: C
authors.initials: C
authors.lastname: Kohchi
authors.forename: G
authors.initials: G
authors.lastname: Soma
authors.forename: D
authors.initials: D
authors.lastname: Mizuno
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002454:Cell Differentiation; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003165:Complement System Proteins; D004622:Embryo, Mammalian / Q000502:physiology; D006017:Glycolipids / Q000378:metabolism; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D009439:Neuraminidase / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D006017:Glycolipids; D003165:Complement System Proteins; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid