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据5月15日的《科学》杂志报道说，研究人员发现了可有助启动雌性小鼠卵巢内排卵过程的一对酶。 这些发现可能对研发不孕症的新的治疗方法非常重要，尽管人们首先必须作更多的研究以了解干扰这些酶的功能会对其它类型的组织造成怎样的影响。 在雌性的哺乳动物中，其脑垂体会释放出黄体生成素的每月一次的高峰。这些黄体生成素会与那些准备排卵的卵泡颗粒细胞结合。 研究人员仍然在试图解析接着发生的那些导致排卵（或在某些情况下没有排卵）的分子信号级联反应。 Heng-Yu Fan及其同僚现在证明，激酶ERK1和ERK2是该激素信号的至关重要的下游标靶。 在那些颗粒细胞中缺乏这些酶的雌性小鼠中，其卵母细胞不会成熟，因而不会从它们的滤泡中释放出来。 同样地，用激素刺激过的滤泡不会转变成为“黄体”（即在滤泡从其卵巢中释放出卵母细胞之后通常会形成的组织）。 研究人员报告说，ERK1 和ERK2本身看来会将一个叫做CEBPbeta的转录因子作为其标靶，而它们是在一个非常短暂的时间窗内（大约为2小时）发挥其功效的。 一则相关的Perspective文章指出，这些发现可以帮助阐明人类的诸如多发性卵巢囊肿等卵巢疾病的发病机制，这是女性不孕症的一种常见原因。 推荐原始出处： Science 15 May 2009: DOI: 10.1126/science.1171396 MAPK3/1 (ERK1/2) in Ovarian Granulosa Cells Are Essential for Female Fertility Heng-Yu Fan,1 Zhilin Liu,1 Masayuki Shimada,2 Esta Sterneck,3 Peter F. Johnson,4 Stephen M. Hedrick,5 JoAnne S. Richards1,* A surge of luteinizing hormone (LH) from the pituitary gland triggers ovulation, oocyte maturation, and luteinization for successful reproduction in mammals. Because the signaling molecules RAS and ERK1/2 (extracellular signal–regulated kinases 1 and 2) are activated by an LH surge in granulosa cells of preovulatory follicles, we disrupted Erk1/2 in mouse granulosa cells and provide in vivo evidence that these kinases are necessary for LH-induced oocyte resumption of meiosis, ovulation, and luteinization. In addition, biochemical analyses and selected disruption of the Cebpb gene in granulosa cells demonstrate that C/EBPβ (CCAAT/Enhancer-binding protein–β) is a critical downstream mediator of ERK1/2 activation. Thus, ERK1/2 and C/EBPβ constitute an in vivo LH-regulated signaling pathway that controls ovulation- and luteinization-related events. 1 Department of Molecular and Cellular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA. 2 Department of Applied Animal Science, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, 739-8528, Japan. 3 Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute–Frederick, Frederick, MD 21702–1201, USA. 4 Basic Research Laboratory, Center for Cancer Research, National Cancer Institute–Frederick, Frederick, MD 21702–1201, USA. 5 Molecular Biology Section, Division of Biological, Sciences and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA. (责任编辑：Doctor001) |
