摘要：
Objective·To investigate the changes and distribution of thyroid transcription factor-1 (TTF1) expression around the puberty and to explore the position relationship among gonadotropin-releasing hormone (GnRH), KiSS1 and TTF1 expression in the hypothalamus of female SD rats. Methods?·?Female SD rats were divided into three groups: juvenile (JUV), early puberty (EP), and adult (AD). Tissue immunofluorescence staining was used to detect the expression of TTF1, KiSS1 and GnRH immunoreactive cells in the hypothalamus and the relative position among them. Real-time PCR was used to measure the expression of KiSS1, GnRH, TTF1 on mRNA levels in the hypothalamus, anteroventral periventricular nucleus (AVPV), and arcuate nucleus (ARC) respectively. Western blotting was performed to detect the changes in protein level of KiSS1 and TTF1. Results?·?TTF1 was densely expressed in hypothalamus nucleus AVPV, ARC and median eminence (ME) of female rats. GnRH,KiSS1 and TTF1 were adjacently expressed in ARC and ME. The mRNA level of TTF1 in the hypothalamus showed an upward trend after a slight decrease, while in AVPV and ARC tended to be consistent and showed an upward trend. The GnRH mRNA expression levels were significantly increased and reached the peak at AD. The mRNA expression levels of KiSS1 showed a sharp rise which was prior to the peak expression of GnRH mRNA at EP and then sustained the high level until AD. The protein expression level of TTF1 reached the peak at AD and the KiSS1 expression showed a sustained growth. Both of them showed an upward trend and basically consistent with the mRNA expression trend. Conclusion?·?Neuronal nuclei protein TTF1 mainly expressed in the nuclei AVPV, ARC, and ME of female rat hypothalamus. It was prominent in cells of ARC and ME which were localized GnRH, KiSS1, TTF1 positive neural cells. During the development of puberty onset, KiSS1 mRNA preceded GnRH mRNA to reach the peak at EP. The expression of TTF1 mRNA increased and reached a peak at AD, which was consistent with the overall increase of KiSS1 and GnRH expression. Protein expression of KiSS1 showed a corresponding upward trend together with their mRNA expression. TTF1 protein expression increased and peaked in AD.%目的·探讨TTF1(thyroid transcription factor-1)在雌性SD大鼠青春发育前后下丘脑中表达的变化、分布及其与KiSS1、GnRH(gonadotropin-releasing hormone)表达的关系.方法·SD雌鼠按性发育阶段分为幼年组(JUV组)、性发育早期组(EP组)、性成熟组(AD组);组织免疫荧光染色检测TTF1、KiSS1、GnRH免疫反应阳性细胞在下丘脑的分布及相对位置关系;real-time PCR技术检测各组下丘脑、前腹侧室周核(AVPV)及弓状核(ARC)中KiSS1、GnRH、TTF1 mRNA表达,Western blotting技术检测KiSS1、TTF1蛋白在下丘脑的表达水平.结果·TTF1在雌鼠下丘脑AVPV、ARC、正中隆突(ME)有较密集表达.GnRH、KiSS1与TTF1在ARC及ME存在共同染色区域.在下丘脑,TTF1 mRNA表达趋势显示为先略有下降后显著升高;在AVPV、ARC核团中,TTF1 mRNA表达皆呈上升趋势. GnRH mRNA的表达水平随青春发育持续上升,在AD期达高峰;KiSS1 mRNA表达先于GnRH mRNA,在EP期达高峰,AD期维持高水平.在下丘脑,EP期TTF1蛋白表达下降,在AD期达到高峰,KiSS1蛋白表达呈持续上升趋势,与mRNA表达趋势一致.结论· 核蛋白TTF1主要分布于下丘脑AVPV、ARC、ME,GnRH、KiSS1与其在ARC及ME有共同表达区域.随着青春发育,在mRNA水平上,KiSS1先于GnRH在EP达峰值,TTF1表达呈升高趋势,在AD达到高峰,与KiSS1、GnRH表达趋势一致.蛋白水平上,KiSS1表达与mRNA整体升高趋势相同,TTF1表达呈升高趋势,在AD达到峰值.
