Simpson K S, Byers M J, Curry T E
Department of Obstetrics and Gynecology, University of Kentucky, Lexington, Kentucky 40536, USA.
Endocrinology. 2001 May;142(5):2058-69. doi: 10.1210/endo.142.5.8167.
The tissue inhibitors of metalloproteinases (TIMPs) within the ovary closely regulate the matrix metalloproteinases, enzymes capable of degrading components of the extracellular matrix. The purpose of this study was to examine the spatial and temporal messenger RNA (mRNA) expression of the TIMPs in the ovaries of normally cycling rats. Ovaries were collected at 1100 h on each day of the 4-day estrous cycle, and TIMP mRNA expression was examined by Northern blot, RT-PCR, or in situ hybridization. TIMP-1 mRNA levels were significantly higher on estrus than on any other day. Although the 1.0-kb TIMP-2 transcript did not change across the cycle, the 3.5-kb transcript decreased significantly between metestrus and diestrus. Expression of TIMP-3 mRNA decreased significantly between proestrus and estrus. TIMP-1, TIMP-2, and TIMP-3 mRNAs were primarily localized to the theca, stroma, and corpora lutea (CL) on all days of the cycle, but with distinct cyclic changes. Thecal expression of TIMP-1 and TIMP-2 mRNAs was especially high immediately before and after ovulation. TIMP-1 and TIMP-3 mRNAs, which were low to undetectable in the granulosa cells of preovulatory follicles, were greatly increased in the luteinizing cells of newly forming CL on estrus. Although the presence of TIMP-1 mRNA in the granulosa cells of preovulatory follicles by in situ hybridization was near background levels, it was specifically identified in granulosa cells of follicles on all days of the cycle using laser capture microdissection and RT-PCR. Both TIMP-2 and TIMP-3 transcripts were up-regulated in luteinized follicles on proestrus and were present throughout the cycle in regressing CL. In summary, the unique and dynamic expression patterns of the TIMPs suggest that they have important, yet distinct, functions in the ovary. The high levels of TIMP-1 mRNA in the CL on estrus indicate a likely role for this inhibitor in luteal formation. The presence of TIMP-2 mRNA in regressing CL suggests an involvement in luteal demise, whereas TIMP-3 may play a role in the health of the follicle as well as in CL regression.
卵巢中的金属蛋白酶组织抑制剂（TIMPs）紧密调节基质金属蛋白酶，这些酶能够降解细胞外基质的成分。本研究的目的是检测正常发情周期大鼠卵巢中TIMPs的时空信使核糖核酸（mRNA）表达。在4天发情周期的每一天的1100时采集卵巢，并通过Northern印迹、逆转录聚合酶链反应（RT-PCR）或原位杂交检测TIMP mRNA表达。TIMP-1 mRNA水平在发情期显著高于其他任何一天。虽然1.0 kb的TIMP-2转录本在整个周期中没有变化，但3.5 kb的转录本在动情后期和间情期之间显著下降。TIMP-3 mRNA表达在发情前期和发情期之间显著降低。在周期的所有日子里，TIMP-1、TIMP-2和TIMP-3 mRNA主要定位于卵泡膜、基质和黄体（CL），但有明显的周期性变化。排卵前后，卵泡膜中TIMP-1和TIMP-2 mRNA的表达特别高。在排卵前卵泡的颗粒细胞中低至无法检测到的TIMP-1和TIMP-3 mRNA，在发情期新形成的CL的黄体化细胞中大大增加。尽管通过原位杂交在排卵前卵泡的颗粒细胞中TIMP-1 mRNA的存在接近背景水平，但使用激光捕获显微切割和RT-PCR在周期的所有日子里在卵泡的颗粒细胞中都能特异性地鉴定到它。TIMP-2和TIMP-3转录本在发情前期的黄体化卵泡中均上调，并在退化的CL中整个周期都存在。总之，TIMPs独特而动态的表达模式表明它们在卵巢中具有重要但不同的功能。发情期CL中高水平的TIMP-1 mRNA表明该抑制剂在黄体形成中可能起作用。退化CL中TIMP-2 mRNA的存在表明其参与黄体退化，而TIMP-3可能在卵泡健康以及CL退化中起作用。
