Expression and glycosylation with polylactosamine of CD44 antigen on macrophages during follicular atresia in pig ovaries
Expression and glycosylation with polylactosamine of CD44 antigen on macrophages during follicular atresia in pig ovaries
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DOI：
10.1095/biolreprod.105.045641
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发表时间：
2006-03-01
影响因子：
3.6
通讯作者：
Sato, E
中科院分区：
文献类型：
--
作者：
Miyake, Y;Matsumoto, H;Sato, E
巨噬细胞在清除卵泡闭锁过程中凋亡碎片中是必不可少的。然而，这一过程的关键因素仍不清楚。在本研究中，我们评估了CD 44 mRNA，CD 44蛋白，和CD 44抗原糖基化的巨噬细胞在卵泡闭锁在猪。闭锁分为5个阶段：第1阶段，健康卵泡;第2阶段，早期闭锁卵泡，颗粒细胞凋亡，基底膜不清;第3阶段，进展性闭锁卵泡，颗粒细胞凋亡，颗粒细胞完全从基底膜扩散;第4阶段，晚期闭锁卵泡，溶酶体活性增加;和V期，闭锁卵泡解体，卵泡膜细胞塌陷，溶酶体活性强。免疫组织化学分析显示，表达CD 44的巨噬细胞侵入III期卵泡内部，伴随着基底膜的塌陷。半定量RT-PCR结果显示，卵泡内细胞中仅表达CD 44标准亚型（CD 44 s）的mRNA，而不表达CD 44变异亚型（CD 44 v）的mRNA。CD 44 s mRNA表达在III期增加。Westernblot和凝集素印迹分析表明，CD 44在III期显著表达，同时被聚乳糖胺糖基化。在III-V期闭锁卵泡中，巨噬细胞侵入后，巨噬细胞上表达的CD 44被聚乳糖胺糖基化。溶酶体活性在IV期开始增加，并在V期达到最高水平。增加的CD 44 s蛋白和翻译后修饰的CD 44与聚乳糖胺对巨噬细胞从III期可能参与清除凋亡的颗粒细胞。
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 1, 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.