Regulation of rat ovarian cell growth and steroid secretion
Regulation of rat ovarian cell growth and steroid secretion
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大鼠卵巢细胞生长和类固醇分泌的调节
作者：
C. Johnson;W. Dawson;J. Turner;J. Wyche
使用培养的大鼠卵巢细胞系（31 A-F（2））研究生长因子（表皮生长因子[EGF]和成纤维细胞生长因子[FGF]）、存活因子（卵巢生长因子[OGF]）、激素（胰岛素）和铁结合蛋白（转铁蛋白）在规定的培养条件下对细胞增殖和类固醇产生的影响。EGF和胰岛素对在无血清培养基中培养的31A-F（2）细胞显示出促有丝分裂作用（半最大反应分别为0.12 nM和0.11 μ M）。EGF在细胞群中诱导多达三个倍增，而胰岛素平均诱导一个细胞群倍增。当在无血清培养基中单独与31A-F（2）细胞孵育时，发现FGF、OGF和转铁蛋白对细胞分裂没有任何显著影响。然而，EGF、OGF、胰岛素和转铁蛋白的组合刺激细胞分裂的程度与在5%胎牛血清存在下孵育的细胞相同。当单独与31A-F（2）细胞孵育时，EGF或胰岛素对总细胞胆固醇水平（相对于在无血清培养基中孵育的细胞）没有显著影响。然而，细胞胆固醇水平增加OGF（250%），FGF（370%），或胰岛素和EGF（320%）的组合。EGF（25%）、FGF（80%）和胰岛素（115%）可增强31A-F（2）细胞的孕酮分泌。然而，加入EGF、OGF、胰岛素和转铁蛋白的促有丝分裂混合物抑制孕酮分泌，低于对照培养物的50%。这些研究使我们能够确定EGF和胰岛素是31A-F（2）细胞生长所需的促有丝分裂因子，而OGF和转铁蛋白是促进生长的正辅因子。此外，额外的数据表明，31A-F（2）细胞中胆固醇和孕酮的产生可以通过肽生长因子和胰岛素激素来调节。
A cultured rat ovarian cell line (31 A-F(2)) was used to study the effect of growth factors (epidermal growth factor [EGF] and fibroblast growth factor [FGF]), a survival factor (ovarian growth factor [OGF]), a hormone (insulin), and an iron-binding protein (transferring) on cell proliferation and steroid production under defined culture conditions. EGF and insulin were shown to be mitogenic (half-maximal response at 0.12 nM and 0.11 muM, respectively) for 31A-F(2) cells incubated in serum-free medium. EGF induced up to three doublings in the cell population, whereas insulin induced an average of one cell population doubling. FGF, OGF, and transferrin were found not to have any prominent effect on cell division when incubated individually with 31A-F(2) cells in serum-free medium. However, a combination of EGF, OGF, insulin, and transferrin stimulated cell division to the same approximate extent as cells incubated in the presence of 5 percent fetal calf serum. EGF or insulin did not significantly affect total cell cholesterol levels (relative to cells incubated in serum-free medium) when incubated individually with 31A-F(2) cells. However, cell cholesterol levels were increased by the addition of OGF (250 percent), FGF (370 percent), or a combination of insulin and EGF (320 percent). Progesterone secretion from 31A-F(2) cells was enhanced by EGF (25 percent), FGF (80 percent), and insulin (115 percent). However, the addition of a mitogenic mixture of EGF, OGF, insulin, and transferrin suppressed progesterone secretion 150 percent) below that of control cultures. These studies have permitted us to determine that EGF and insulin are mitogenic factors that are required for the growth of 31A-F(2) cells and that OGF and transferrin are positive cofactors that enhance growth. Also, additional data suggest that cholesterol and progesterone production in 31A-F(2) cells can be regulated by peptide growth factors and the hormone insulin.