title: Retardation of removal of radiation-induced apoptotic cells in developing neural tubes in macrophage galactose-type C-type lectin-1-deficient mouse embryos.
abstract: MGL1/CD301a is a C-type lectin that recognizes galactose and N-acetylgalactosamine as monosaccharides and is expressed on limited populations of macrophages and dendritic cells at least in adult mice. In this study, pregnant mice with Mgl1+/- genotype were mated with Mgl1+/- or Mgl1-/- genotype males, and the embryos were used to assess a hypothesis that this molecule plays an important role in the clearance of apoptotic cells. After X-ray irradiation at 1 Gy of developing embryos at 10.5 days post coitus (d.p.c.), the number of Mgl1-/- pups was significantly reduced as compared with Mgl1+/+ pups. Distributions of MGL1-positive cells, MGL2-positive cells, and apoptotic cells were histologically examined in irradiated Mgl1+/+ embryos. MGL1-positive cells were detected in the neural tube in which many cells undergo apoptosis, whereas MGL2-positive cells were not observed. Biotinylated recombinant MGL1 bound a significant portion of the apoptotic cells. When Mgl1+/+ and Mgl1-/- embryos were examined for the presence of apoptotic cells, similar numbers of apoptotic cells gave rise, but the clearance of these cells was slower in Mgl1-/- embryos than in Mgl1+/+ embryos. These results strongly suggest that MGL1/CD301a is involved in the clearance of apoptotic cells. This process should be essential in the repair and normal development of X-ray-irradiated embryos.
authors.affiliation: Department of Radiation Oncology, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yuita
authors.forename: Makoto
authors.initials: M
authors.lastname: Tsuiji
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tajika
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Kazuya
authors.initials: K
authors.lastname: Hirano
authors.forename: Norio
authors.initials: N
authors.lastname: Suzuki
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Irimura
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D017209:Apoptosis; D001212:Asialoglycoproteins / Q000235:genetics; D001665:Binding Sites; D019921:Biotinylation; D005260:Female; D005690:Galactose / Q000737:chemistry; D005838:Genotype; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D037102:Lectins / Q000235:genetics*; D037181:Lectins, C-Type / Q000235:genetics; D008264:Macrophages / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009432:Neural Crest / Q000166:cytology* / Q000196:embryology* / Q000378:metabolism; D010587:Phagocytosis; D011994:Recombinant Proteins / Q000737:chemistry; D013997:Time Factors; D014965:X-Rays
chemical_list: D000911:Antibodies, Monoclonal; D001212:Asialoglycoproteins; C064720:Clec10a protein, mouse; D037102:Lectins; D037181:Lectins, C-Type; D008565:Membrane Proteins; D011994:Recombinant Proteins; D005690:Galactose