Endocrinological and immunological study for local regulation of ovarian function

最近，调节促性腺激素作用的性激素、生长因子和细胞因子被认为参与了卵巢功能的局部调节。在本研究中，我们研究了包括内分泌和免疫在内的调控因素，以全面了解卵巢细胞分化的局部调控系统。本实验采用猪颗粒细胞培养和人黄体生成颗粒细胞培养，建立了小鼠促排卵、猪和人卵泡膜细胞培养的幼鼠模型。利用猪颗粒细胞培养，发现颗粒细胞表面存在氨肽酶活性，该酶能代谢包括细胞因子在内的多种多肽。抑制氨基肽酶的活性，促进颗粒细胞的黄体化。小鼠卵巢局部应用Bestatin可促进排卵，提示膜结合肽酶(S)是卵泡生长的重要调节因子。在黄体形成过程中，人黄体颗粒细胞表达另一种膜结合的二肽基肽酶IV(DPPIV)。人黄体颗粒细胞培养的流式细胞术分析表明，白介素1α和肿瘤坏死因子α可促进DPPIV的表达，但hCG不能促进DPPIV的表达，而CD2和T淋巴细胞表面表达CD2和4分子的细胞表面抗原HLADR和LFA-3也表达在人黄体颗粒细胞上，这与以前报道的外周血淋巴细胞促进黄体颗粒细胞孕酮产生的结果一致。流式细胞术显示，这些抗原的表达也受细胞因子的调节，这表明在黄体形成过程中，免疫系统和内分泌系统都在运行。

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.