Endocrinological and immunological study for local regulation of ovarian function

近年来，性类固醇激素、生长因子和细胞因子等调节促性腺激素的作用，被认为参与了卵巢功能的局部调节。在本研究中，我们研究了调节因素，包括内分泌和免疫因素，以全面了解卵巢细胞分化的局部调节系统。本研究采用猪卵泡膜细胞和人卵泡膜细胞培养方法，建立了未成熟小鼠促排卵、猪卵泡膜细胞和人卵泡膜细胞培养模型。通过猪颗粒细胞培养，发现颗粒细胞表面存在氨肽酶活性，其可代谢包括细胞因子在内的多种肽。氨肽酶活性的抑制剂，bestatin的抑制，增强颗粒细胞的黄体化。小鼠卵巢局部给予bestatin刺激排卵，表明膜结合肽酶是卵泡生长的重要调节因子。另一种膜结合肽酶，二肽基肽酶IV（DPPIV），被发现表达于黄体形成过程中的人黄体化颗粒细胞。使用人黄体化颗粒细胞培养物的流式细胞术分析表明，DPPIV的表达被白细胞介素-1 α和肿瘤坏死因子-α增强，但不被hCG增强。HLA-DR和LFA-3，它们是T淋巴细胞上表达的CD 2和4分子的细胞粘附相关细胞表面抗原，也被揭示在人黄体化颗粒细胞上表达，这与先前报道的外周淋巴细胞增强人促黄体化颗粒细胞产生孕酮的观察结果一致。流式细胞术表明，这些抗原的表达也受到细胞因子的调节，这表明免疫系统以及内分泌系统在黄体形成过程中起作用。

Recently, sex steroid hormones, growth factors, and cytokines, which modulate the effects of gonadotropins, have been proposed to be involved in the local regulation for ovarian function. In this study, we investigated the regulatory factors including endocrine and immune ones to totally understand local regulation systems for ovarian cell differentiation. In the aim, we used porcine granulosa cell culture and human luteinizing granulosa cell culture, and have established an immature mouse model for ovulation induction, porcine and human theca cell culture. By using porcine granulosa cell culture, aminopeptidase activity, which can metabolize several peptides including cytokines, was revealed to be present one the cell surface of granulosa cells. The inhibition of the aminopeptidase activity by an inhibitor, bestatin, enhanced luteinization of granulosa cells. Local administration of bestatin into murine ovaries stimulated ovulation, indicating that membrane-bound peptidase (s) are important regulators for follicular growth. Another membrane-bound pepitdase, dipeptidyl peptidase IV (DPPIV) , was found to be expressed on human luteinizing granulosa cells during corpus luteum formation. Flow cytometric analysis using human luteinizing granulosa cell culture indicated that the expression of DPPIV is enhanced by interleukin-1alpha and tumor necrosis factor-alpha, but not by hCG.HLA-DR and LFA-3, which are cell adhesion-related cell surface antigens for CD2 and 4 molecules expressed on T-lymphocytes, were also revealed to be expressed on human luteinizing granulosa cells, being compatible with the previously reported observation that peripheral lymphocytes enhanced progesterone production by human luteinizing granulosa cells. Flow cytometry showed that the expression of these antigens were also regulated by cytokines, suggesting that an immune system as well as an endocrine system operates during corpus luteum formation.