Lee Hyojin, Kim Heejung, Chung Yiwa, Kim Jinhee, Yang Hyunwon
Department of Bioenvironmental Technology, College of Natural Sciences, Seoul Women's University, Seoul 139-774, Republic of Korea.
Dev Reprod. 2013 Dec;17(4):441-9. doi: 10.12717/DR.2013.17.4.441.
Recent study showed that T cells in the immune organs and peripheral blood are influenced by estradiol, leading to a dysfunction of the immune system. However, little is known about the thymic-gonadal relationship during the estrous cycle in mouse. Therefore, the purpose of this study was to elucidate the mechanism by which a change in estradiol levels during the estrous cycle regulates the development of T cells in the mouse thymus. Six-week-old ICR mice were used and divided into four groups, including diestrous, proestrous, estrous, and metestrous. We first confirmed that ER-α and - β estrogen receptors were expressed in thymic epithelial cells, showing that their expression was not different during the estrous cycle. There was also no significant difference in thymic weight and total number of thymocytes during the estrous cycle. To determine the degree of thymocyte differentiation during the estrous cycle, we analyzed thymocytes by flow cytometry. As a result, the percentage of CD4+CD8+ double-positive (DP) T cells was significantly decreased in the proestrous phase compared to the diestrous phase. However, CD4+CD8- or CD4-CD8+ (SP) T cells were significantly increased in the proestrous phase compared to the diestrous phase. In addition, the percentage of CD44+CD25- (DN1) T cells was significantly decreased in the estrous phase compared to other phases, whereas the percentages of CD44+CD25+ (DN2), CD44-CD25+ (DN3), and CD44-CD25- (DN4) were not changed during the estrous cycle. These results indicate that the development of thymocytes may arrest in the DP to SP transition stage in the proestrous phase displaying the highest serum level of estradiol. This study suggests that a change in estradiol levels during the estrous cycle may be involved in the regulation of thymocyte differentiation in the mouse thymus.
最近的研究表明，免疫器官和外周血中的T细胞会受到雌二醇的影响，从而导致免疫系统功能失调。然而，对于小鼠发情周期中胸腺与性腺的关系却知之甚少。因此，本研究的目的是阐明发情周期中雌二醇水平的变化调节小鼠胸腺中T细胞发育的机制。使用6周龄的ICR小鼠并将其分为四组，包括动情后期、动情前期、发情期和动情间期。我们首先证实雌激素受体ER-α和 - β在胸腺上皮细胞中表达，表明它们在发情周期中的表达没有差异。发情周期中胸腺重量和胸腺细胞总数也没有显著差异。为了确定发情周期中胸腺细胞的分化程度，我们通过流式细胞术分析胸腺细胞。结果显示，与动情后期相比，动情前期CD4+CD8+双阳性（DP）T细胞的百分比显著降低。然而，与动情后期相比，动情前期CD4+CD8-或CD4-CD8+（SP）T细胞显著增加。此外，与其他阶段相比，发情期CD44+CD25-（DN1）T细胞的百分比显著降低，而动情周期中CD44+CD25+（DN2）、CD44-CD25+（DN3）和CD44-CD25-（DN4）的百分比没有变化。这些结果表明，在动情前期雌二醇血清水平最高时，胸腺细胞的发育可能停滞在DP向SP的转变阶段。本研究表明，发情周期中雌二醇水平的变化可能参与小鼠胸腺中胸腺细胞分化的调节。
