卵巢胰岛素抵抗对卵巢糖代谢及功能影响的实验研究

Insulin resistance enhanced the response of the ovary

目的探讨卵巢内胰岛素信号分子缺失对卵巢自身功能影响，为阐明卵巢局部胰岛素抵抗对生殖功能作用提供理论支撑。方法（1）分别选择蛋白激酶B2（AKT2）基因缺失的（AKT2-）和其同窝出生的有完整AKT2基因（AKT2＋）的雌性小鼠评估卵巢糖摄取情况，并进行卵巢交互移植，构建AKT2基因型组合个体分别为A组（躯体＋，卵巢＋）12只，B组（躯体＋，卵巢-）15只，C组（躯体-，卵巢＋）8只。（2）监测动情周期，随机分组，对刺激组小鼠采用卵泡刺激素（0．75IU／g）进行干预后取材。评估各组小鼠卵巢组织形态与生殖激素指标，并且采用RT-PCR检测卵巢内胰岛素信号分子和甾体激素合成酶的表达。结果（1）AKT2-卵巢的葡萄糖摄取能力显著下降。（2）B组动情周期显著延长，卵巢内黄体数量明显减少，而卵泡的数量明显增多，同时17一OH和T的水平显著升高。（3）基础状态下，B组卵巢内ERK-1和CYP17的表达明显增强。刺激状态下，B组卵巢内ERK-1、CYP17、CYP19和GSK3B均显著升高。结论（1）AKT2-小鼠卵巢存在胰岛素抵抗，出现动情周期延长，卵巢多囊性改变和雄激素及其合成酶水平增高，类似PCOS表现。（2）卵巢局部胰岛素抵抗使卵巢自身糖代谢异常，细胞分裂增殖功能亢进，卵巢对促性腺激素反应性增高，卵巢功能放大，可能是PCOS发病的关键因素。

Objective To search for the role of impaired insulin signaling in the ovary reproductive failure and abnormal metabolic profiles in the AKT2 - mouse. Methods Adult, female129/C57BIJ6 （AKT2 - ） mice were used in these studies. Littermate wide types C57BL/6J（ AKT2 ＋ ）, as well as mutant genotypes （AKT2 - ）. The ovaries were abtained from 6 AKT2 ＋ type mice as wall as 6 mutant genotypes, which was used for insulin stimulated glucose uptake study. By ovary transplantation on the day of 12 weeks, three genotypic mice were constructed with body AKT2 ＋ and ovary AKT2 ＋ in Group A, body AKT2 ＋ and ovary AKT2 - in Group B, body AKT2 - and ovary AKT2 ＋ in Group C. The vaginal smear was done to evaluate the recovery and cyclicity of transplanted ovaries with mutant or intact AKT2. Before execution, every group was randomly separated into basal and stimulated groups in which the mice were injected recombination FSH （0. 75 IU/g） , and then AKT2,GSK3[5,ERK-1 ,CYP17 and CYP19 were determined by RT-PCR in the ovaries, and the serum were reserved for the assay of HDL-C, CHO, TG, 17-OHP progesterone, E2, T, and LH. The weight of each mouse, their ovary and their fat pads and the estrus cycle,were also recorded. Results （ 1 ） The weight of fat pads beside ovaries and fold inguen in C group were significant higher than the other groups. （2） The level of 17-OHP progesterone in B group was higher than A or C group both in basal and FSH-stimulated groups. （ 3 ） In the basal group the expression of ERK- land CYP17 were enhanced. Moreover in FSH-dtimulated group, the expression of ERK-1 , CYP17, CYP19 and GSK3B in B group were higher as compared with the other groups. Conclusion （ 1 ） IR existed in the ovary of AKT2 - type, and the mice with AKT2 - type ovary had delayed cycle, PCO and high level of 17- OHP, which were similar with PCOS. （2） Metabolic dysfunction in the AKT2 - mice has close relationship with whole body condition, but not defective insulin signal within ovaries. （3） Defects of insulin activity in the metabolic pathway could induce the increased expression of ERK-1 and mitogenic potential indicating the cross-talk between two pathways of insulin signaling within ovarian cells. Consequently, ovarian hyperovarianism was induced in the defective ovaries, which contribute to the enhanced response to gonadotropin and synthesis of steroid hormone.