Tirone E, Siracusa G, Hascall V C, Frajese G, Salustri A
Department of Public Health and Cell Biology, University of Rome Tor Vergata, Italy.
Dev Biol. 1993 Dec;160(2):405-12. doi: 10.1006/dbio.1993.1316.
A soluble factor(s) produced by fully grown oocytes is essential, together with follicle stimulating hormone (FSH), to stimulate in vitro hyaluronic acid (HA) synthesis by mouse cumulus cells (CCs). The stability of the response to this stimulus by CCs in culture was investigated. The data showed that preculture for 8 hr in basal medium reduced to approximately 30% the ability of CCs to synthesize HA in response to FSH or dibutyryl cyclic AMP (Bt2cAMP) and soluble oocyte factor(s). However, if CCs were precultured for the same period of time as intact cumulus cell-oocyte complexes, or in the presence of fully grown oocytes, or in medium conditioned by fully grown oocytes, their ability to synthesize HA was 75-95% preserved. In vitro stimulation of dermatan sulfate (DS) synthesis by CCs does not require oocyte factors and is induced by FSH or Bt2cAMP treatment alone. However, the preservation of such activity, like that of HA synthesis, depended on the presence of a soluble oocyte factor(s) during preculture. The presence of isolated oocytes or of oocyte-conditioned medium also prevented the spreading of CCs in culture. However, inhibiting CC spreading by culture on agar-coated plates or in serum-free medium did not preserve their HA or DS synthetic activity, thus suggesting that the two oocyte actions on CCs are independent. Growing oocytes were unable both to induce HA synthesis in freshly isolated CCs stimulated with FSH and to preserve the ability to synthesize HA and DS in 8-hr precultured CCs. The results suggest that the stability of the differentiated state of mouse CCs in vitro depends upon continued exposure to a soluble factor(s) produced by fully grown oocytes.
完全成熟的卵母细胞产生的一种或多种可溶性因子，与促卵泡激素（FSH）一起，对于刺激小鼠卵丘细胞（CCs）体外透明质酸（HA）合成至关重要。研究了培养中的CCs对这种刺激反应的稳定性。数据显示，在基础培养基中预培养8小时后，CCs对FSH或二丁酰环磷腺苷（Bt2cAMP）以及可溶性卵母细胞因子作出反应合成HA的能力降低至约30%。然而，如果CCs与完整的卵丘细胞 - 卵母细胞复合体预培养相同的时间，或者在完全成熟的卵母细胞存在的情况下，或者在完全成熟的卵母细胞条件培养基中预培养，它们合成HA的能力可保留75 - 95%。CCs体外硫酸皮肤素（DS）合成的刺激不需要卵母细胞因子，单独的FSH或Bt2cAMP处理即可诱导。然而，与HA合成一样，这种活性的保留取决于预培养期间可溶性卵母细胞因子的存在。分离的卵母细胞或卵母细胞条件培养基的存在也阻止了CCs在培养中的铺展。然而，通过在琼脂包被的平板上培养或在无血清培养基中培养来抑制CCs铺展并不能保留它们的HA或DS合成活性，因此表明卵母细胞对CCs的这两种作用是独立的。正在生长的卵母细胞既不能在FSH刺激的新鲜分离的CCs中诱导HA合成，也不能在预培养8小时的CCs中保留合成HA和DS的能力。结果表明，小鼠CCs体外分化状态的稳定性取决于持续暴露于完全成熟的卵母细胞产生的一种或多种可溶性因子。
