Androgens and Very Low Density Lipoprotein Are Essential for the Growth of Previtellogenic Oocytes from Japanese Eel, Anguilla japonica, In Vitro
Androgens and Very Low Density Lipoprotein Are Essential for the Growth of Previtellogenic Oocytes from Japanese Eel, Anguilla japonica, In Vitro
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DOI：
10.1095/biolreprod.110.087163
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发表时间：
2011-04-01
影响因子：
3.6
通讯作者：
Yamauchi, Kohei
中科院分区：
文献类型：
--
作者：
Endo, Taku;Todo, Takashi;Yamauchi, Kohei
为了更详细地研究鳗鱼卵母细胞对脂质摄取的调控，在体外测定了11-酮睾酮（11-KT）和脂质转运蛋白（脂蛋白）的作用。卵巢外植体从previtellogenic日本鳗鱼（日本鳗鲡）孵育28天与11-KT和/或极低密度脂蛋白（VLDL），低密度脂蛋白（LDL），或高密度脂蛋白（HDL）从鳗鱼血浆纯化。雄激素11-KT诱导卵母细胞直径显著增加，这是伴随着空泡的出现，而不是脂质。LDL和HDL增加卵母细胞直径，而VLDL没有。然而，共孵育的11-KT和VLDL，而不是LDL或HDL，导致卵母细胞的大小和脂滴表面积显着增加。11-KT（卵母细胞的大小）和VLDL（脂滴表面积）的影响是剂量依赖性的1和100 ng/ml之间和0.5和5 mg/ml之间，分别。有趣的是，如果Vldl浓度足够高（>= 5 mg Vldl/ml培养基），在与11-KT和Vldl共培养的条件下，异常卵母细胞细胞学基本上可以被预防。与11-KT不同，雌二醇-17 β对卵母细胞直径或脂滴表面积没有影响。我们的结论是，VLDL是一个关键的中性脂质的转运蛋白，积累到鳗鱼卵母细胞在卵子发生和VLDL依赖的脂质摄取刺激的雄激素11-KT。
To investigate the regulation of lipid uptake into the eel oocyte in more detail, effects of 11-ketotestosterone (11-KT) and lipid transporters (lipoproteins) were determined in vitro. Ovarian explants from previtellogenic Japanese eels (Anguilla japonica) were incubated for 28 days with 11-KT and/or with very low density lipoproteins (Vldl), low density lipoproteins (Ldl), or high density lipoproteins (Hdl) purified from eel plasma. The androgen 11-KT induced notable increases in oocyte diameter, which were accompanied by the appearance of vacuoles rather than lipid. Ldl and Hdl increased oocyte diameters, whereas Vldl did not. However, coincubation of 11-KT and Vldl, but not of Ldl or Hdl, resulted in dramatic increases in oocyte size and lipid droplet surface area. Effects of both 11-KT (oocyte size) and Vldl (lipid droplet surface area) were dose-dependent between 1 and 100 ng/ml and between 0.5 and 5 mg/ml, respectively. Interestingly, abnormal oocyte cytology under conditions of coculture with 11-KT and Vldl could essentially be prevented if Vldl concentrations were high enough (>= 5 mg Vldl/ml medium). Unlike 11-KT, estradiol-17beta had no effect on oocyte diameter or lipid droplet surface area. We conclude that Vldl is a key transporter of neutral lipids that accumulate into the eel oocyte during oogenesis and that Vldl-dependent lipid uptake is stimulated by the androgen 11-KT.