title: Expression and glycosylation with polylactosamine of CD44 antigen on macrophages during follicular atresia in pig ovaries.
abstract: Macrophages are essential in cleaning up apoptotic debris during follicular atresia. However, the key factors of this process are still unclear. In the present study, we evaluated CD44 mRNA, CD44 protein, and CD44 antigen glycosylation on macrophages during follicular atresia in the pig. Atresia was classified into five stages: stage I, healthy follicles; stage II, early atretic follicles having apoptotic granulosa cells with an unclear basement membrane; stage III, progressing atretic follicles having apoptotic granulosa cells completely diffused from the basement membrane; stage IV, late atretic follicles with increasing lysosomal activity; and stage V, disintegrated atretic follicles having collapsed theca cells and strong lysosomal activity. Immunohistological analysis showed that macrophages expressing CD44 invaded the inside of stage III follicles, accompanied by a collapse of basement membrane. Semiquantitative RT-PCR showed that only mRNA of the CD44 standard isoform (CD44s) was present in inner cells of follicles, and not any CD44 variant isoform (CD44v) mRNAs. The amount of CD44s mRNA was increased at stage III. Western blot and lectin blot analyses showed that CD44 was markedly expressed at stage III and glycosylated with polylactosamine at the same time. After macrophages invaded atretic follicles at stages III-V, the CD44 expressed on macrophages was glycosylated with polylactosamine. The lysosomal activity began to increase at stage IV, and reached the highest level at stage V. Increased CD44s protein and posttranslational modification of CD44 with polylactosamine on macrophages from stage III could be involved in the cleaning up apoptotic granulosa cells.
authors.affiliation: Laboratories of Animal Reproduction, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555, Japan. yuko-okuy@bios.tohoku.ac.jp
authors.forename: Yuko
authors.initials: Y
authors.lastname: Miyake
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Masaki
authors.initials: M
authors.lastname: Yokoo
authors.forename: Kohtaro
authors.initials: K
authors.lastname: Miyazawa
authors.forename: Naoko
authors.initials: N
authors.lastname: Kimura
authors.forename: Woro Anindito Sri
authors.initials: WA
authors.lastname: Tunjung
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimizu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sasada
authors.forename: Hisashi
authors.initials: H
authors.lastname: Aso
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Eimei
authors.initials: E
authors.lastname: Sato
mesh_terms: D000606:Amino Sugars / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D005260:Female; D005496:Follicular Atresia / Q000378:metabolism*; D015870:Gene Expression / Q000502:physiology; D006031:Glycosylation; D006107:Granulosa Cells / Q000166:cytology / Q000378:metabolism; D018960:Hyaluronan Receptors / Q000235:genetics* / Q000378:metabolism*; D008247:Lysosomes / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000378:metabolism*; D010053:Ovary / Q000166:cytology / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000378:metabolism; D034421:Sus scrofa
chemical_list: D000606:Amino Sugars; D018960:Hyaluronan Receptors; D011134:Polysaccharides; D012333:RNA, Messenger; C066929:polylactosamine