INTRAFOLLICULAR REGULATION OF OVARIAN TGF-B1 EXPRESSION

转化生长因子β 1（TGF-β 1）已被确定为一个潜在的重要的卵巢内生长因子，由于其对卵泡膜和颗粒细胞功能的显着影响，以及TGF-β 1和卵泡发生的工作的增长的本地化，仍然是一个显着的赤字，我们的知识，它在细胞水平上的调节，以及如何这与卵巢功能。解决有关TGF-β 1功能和调节的谜团代表了该项目的长期目标。使用培养的细胞和完整的半卵泡从猪卵巢，一个模型的调节TGF-β 1的表达已经制定。数据表明，虽然这两种细胞类型表达TGF-β 1 mRNA，只有卵泡膜细胞表达和分泌的生长因子。FSH、LH和cAMP均不刺激培养物中任一分离细胞类型的TGF-β切片。然而，在小的半卵泡中，FSH而不是LH刺激TGF-β 1的分泌，cAMP也是如此。我们推测卵泡膜细胞在卵泡发育过程中表达和分泌TGF-β 1，但它是在FSH作用于颗粒细胞的指导下进行的。我们进一步假设FSH刺激的颗粒细胞产物通过激活PLA/PKC信号转导系统调节卵泡膜细胞TGF-β的表达。为了进一步描述TGF-β 1的卵泡间调节，将确定TGF-β 1自身表达是否发生在颗粒细胞而不是卵泡膜细胞中，这是否由TGF-β I型和II型受体的选择性表达介导，以及自身表达或受体表达是否随卵泡发育而变化。将确定FSH和TGF-β 1 β调节颗粒细胞中其他受体表达的程度。颗粒细胞通过分泌因子直接调节卵泡膜细胞TGF-β 1表达的程度将通过共培养实验进行测试。将确定卵泡TGF-β 1表达是否随着卵泡发育从FSH调控切换到LH调控。最后，将研究能够结合抑制翻译的TGF-β 1 mRNA 5 '-非翻译区的调节茎环结构的胞质蛋白的选择性颗粒细胞表达。这可能是颗粒细胞差异表达TGF-β 1 mRNA而非生长因子的机制。相信本文所述研究的完成将提供关于TGF-β 1的滤泡间旁分泌调节的新的和重要的信息，这将提供对其在卵泡发育期间的作用的深入了解。

Transforming growth factor beta1 (TGF-beta1) has been identified as a potentially important intraovarian growth factor due to its pronounced effects upon theca and granulosa cell function and the localization of the growth of work regarding TGF-beta1 and folliculogenesis, there remains a notable deficit in our knowledge regarding its regulation at the cellular level and how this relates to ovarian function. Solving the riddle regarding TGF- beta1 function and regulation represents the long term goals of this project. Using both cultured cells and intact hemi-follicles from the porcine ovary, a model for the regulation of TGF-beta1 expression has been formulated. Data suggest that although both cell types express TGF-beta1mRNA, only theca cells express and secrete the growth factor. Neither FSH, LH, nor cAMP stimulates TGF-beta section in either isolated cell type in culture. In small hemi-follicles, however, FSH but not LH stimulates TGF-beta1 secretion as does cAMP. We hypothesize that theca cells express and secrete TGF-beta1 during follicle development but that it is under the direction of FSH acting upon granulosa cells. We further hypothesize that a FSH-stimulated granulosa cell product regulates theca cell TGF-beta expression by activating the PLA/PKC signal transduction system. To further delineate the inter-follicular regulation of TGF-beta1 it will be established whether TGF- beta1 auto expression occurs in granulosa but not theca cells, whether this is mediated by selective expression of TGF-beta type I and II receptors, and whether auto-expression or receptor expression change with follicle development. The extent to which FSH and TGF-beta1 reciprocally regulate the expression of the other receptor in granulosa cells will be determined. The extent to which granulosa cells can directly regulate theca cell TGF- beta1 expression via secretory factors will be tested by co-culture experiments. Whether follicular TGF-beta1 expression switches from FSH to LH governance with follicle development will be determined. Lastly, the selective granulosa cell expression of a cytosolic protein capable of binding to a regulatory stem-loop structure of the TGF-beta1 mRNA 5'-untranslated region which inhibits translation will be investigated. This may be the mechanism by which granulosa cells differentially express TGF-beta1 mRNA but not the growth factor. It is believed that completion of the studies described herein will provide novel and important information regarding inter-follicular, paracrine regulation of TGF-beta1, which will provide insight into its role during follicle development.