title: S100A8, An Oocyte-Specific Chemokine, Directs the Migration of Ovarian Somatic Cells During Mouse Primordial Follicle Assembly.
abstract: In the mammalian ovaries, the primordial follicle pool determines the reproductive capability over the lifetime of a female. The primordial follicle is composed of two cell members, namely the oocyte and the pre-granulosa cells that encircle the oocyte. However, it is unclear what factors are involved in the reorganization of the two distinct cells into one functional unit. This study was performed to address this issue. Firstly, in an in vitro reconstruction system, dispersed ovarian cells from murine fetal ovaries at 19.0 days post coitum (dpc) reassembled into follicle-like structures, independent of the physical distance between the cells, implying that either oocytes or ovarian somatic cells (OSCs) were motile. We then carried out a series of transwell assay experiments, and determined that it was in fact 19.0 dpc OSCs (as opposed to oocytes), which exhibited a significant chemotactic response to both fetal bovine serum and oocytes themselves. We observed that S100A8, a multi-functional chemokine, may participate in the process as it is mainly expressed in oocytes within the cysts/plasmodia. S100A8 significantly promoted the number of migrating OSCs by 2.5 times in vitro, of which 66.9% were FOXL2 protein-positive cells, implying that the majority of motile OSCs were pre-granulosa cells. In addition, an S100A8-specific antibody inhibited the formation of follicle-like reconstruction cell mass in vitro. And, the primordial follicle formation was reduced when S100a8-specific siRNA was applied onto in vitro cultured 17.5 dpc ovary. Therefore, S100A8 could be a chemokine of oocyte origin, which attracts OSCs to form the primordial follicles.
authors.affiliation: State Key Laboratory of Agro-biotechnology, College of Biological Science, China Agricultural University, Beijing,, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Teng
authors.affiliation: State Key Laboratory of Agro-biotechnology, College of Biological Science, China Agricultural University, Beijing,, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agro-biotechnology, College of Biological Science, China Agricultural University, Beijing,, China.
authors.forename: Yijing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agro-biotechnology, College of Biological Science, China Agricultural University, Beijing,, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Agro-biotechnology, College of Biological Science, China Agricultural University, Beijing,, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Xiang
authors.affiliation: State Key Laboratory of Agro-biotechnology, College of Biological Science, China Agricultural University, Beijing,, China.
authors.forename: Wanbao
authors.initials: W
authors.lastname: Niu
authors.affiliation: State Key Laboratory of Agro-biotechnology, College of Biological Science, China Agricultural University, Beijing,, China.
authors.forename: Lizhao
authors.initials: L
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Agro-biotechnology, College of Biological Science, China Agricultural University, Beijing,, China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Agro-biotechnology, College of Biological Science, China Agricultural University, Beijing,, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Agro-biotechnology, College of Biological Science, China Agricultural University, Beijing,, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Agro-biotechnology, College of Biological Science, China Agricultural University, Beijing,, China.
authors.forename: Guoliang
authors.initials: G
authors.lastname: Xia
mesh_terms: D000818:Animals; D040501:Calgranulin A / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D002633:Chemotaxis; D018920:Coculture Techniques; D005260:Female; D000074842:Forkhead Box Protein L2; D051858:Forkhead Transcription Factors / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006107:Granulosa Cells / Q000378:metabolism*; D051379:Mice; D009865:Oocytes / Q000378:metabolism*; D006080:Ovarian Follicle / Q000196:embryology / Q000378:metabolism*; D034622:RNA Interference; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection
chemical_list: D040501:Calgranulin A; D000074842:Forkhead Box Protein L2; D051858:Forkhead Transcription Factors; C498893:Foxl2 protein, mouse; C086145:S100a8 protein, mouse