Huang H L, Chu S T, Chen Y H
Institute of Biochemical Sciences, College of Science, National Taiwan University, Taipei, Taiwan, Republic of China.
J Endocrinol. 1999 Jul;162(1):11-9. doi: 10.1677/joe.0.1620011.
We examined 24p3 expression in the mouse uterus at various stages of the natural estrous cycle and during the preimplantation period. The level of 24p3 mRNA appeared intensively in proestrus and estrus, then declined sharply from metestrus to diestrus. Consistent with this observation, 24p3 protein was abundant in proestrus, decreased from estrus to metestrus and declined to a very low level in diestrus. The uterine 24p3 expression closely overlapped with the estradiol (E2) surge in proestrus and estrus but it was suppressed when progesterone (P4) rose to a high level during the reproductive cycle. Neither the protein nor its message was detected in the uteri of immature mice or ovariectomized adult animals. While an injection of P4 to these animals was unable to initiate uterine 24p3 expression, administration of estrogenic steroids to these animals markedly stimulated the gene expression. Treatment of these animals with E2 together with P4, on the other hand, did not stimulate the gene expression. In pregnant animals (day 1 (D1)=day of vaginal plug), 24p3 mRNA remained at a high level on D1 and D2 but dropped to an almost undetectable level on D3 and D4. This was accompanied by a decrease in 24p3 protein from D1 to D2 and a decline in the protein to undetectable levels from D3 to D4. The staining patterns of both the immunohistochemical localization of 24p3 protein and in situ hybridization for the detection of 24p3 mRNA in the uterine sections showed that 24p3 expression took place mainly in the luminal and glandular epithelial cells of the endometrium. This together with our previous observation that 24p3 protein is found in uterine luminal fluid indicates that the protein is secreted primarily from these cells to their respective luminal surfaces during proestrus and estrus.
我们检测了自然发情周期各阶段及着床前期小鼠子宫中24p3的表达情况。24p3 mRNA水平在发情前期和发情期大量出现，然后从间情期到动情后期急剧下降。与该观察结果一致，24p3蛋白在发情前期丰富，从发情期到间情期减少，在动情后期降至极低水平。子宫24p3表达在发情前期和发情期与雌二醇（E2）激增密切重叠，但在生殖周期中当孕酮（P4）升至高水平时受到抑制。在未成熟小鼠或去卵巢成年动物的子宫中未检测到该蛋白及其信息。虽然向这些动物注射P4无法启动子宫24p3表达，但给这些动物施用雌激素类固醇可显著刺激基因表达。另一方面，用E2和P4共同处理这些动物并未刺激基因表达。在怀孕动物中（第1天（D1）=出现阴栓的日子），24p3 mRNA在D1和D2保持高水平，但在D3和D4降至几乎不可检测的水平。这伴随着24p3蛋白从D1到D2的减少以及从D3到D4该蛋白降至不可检测水平。子宫切片中24p3蛋白的免疫组织化学定位和用于检测24p3 mRNA的原位杂交的染色模式均表明，24p3表达主要发生在子宫内膜的腔上皮细胞和腺上皮细胞中。这与我们之前在子宫腔液中发现24p3蛋白的观察结果一起表明，该蛋白在发情前期和发情期主要从这些细胞分泌到各自的腔表面。
