Department of Laboratory Medicine, Albert Szent-Györgyi Medical School, University of Szeged, 6725 Szeged, Hungary.
Department of Cell Biology and Molecular Medicine, Albert Szent-Györgyi Medical School, University of Szeged, 6720 Szeged, Hungary.
Int J Mol Sci. 2022 Aug 11;23(16):8946. doi: 10.3390/ijms23168946.
Estrogens regulate a variety of neuroendocrine, reproductive and also non-reproductive brain functions. Estradiol biosynthesis in the central nervous system (CNS) is catalyzed by the enzyme aromatase, which is expressed in several brain regions by neurons, astrocytes and microglia. In this study, we performed a complex fluorescent immunocytochemical analysis which revealed that aromatase is colocalized with the nuclear stain in glial fibrillary acidic protein (GFAP) positive astrocytes in cell cultures. Confocal immunofluorescent Z-stack scanning analysis confirmed the colocalization of aromatase with the nuclear DAPI signal. Nuclear aromatase was also detectable in the S100β positive astrocyte subpopulation. When the nuclear aromatase signal was present, estrogen receptor alpha was also abundant in the nucleus. Immunostaining of frozen brain tissue sections showed that the nuclear colocalization of the enzyme in GFAP-positive astrocytes is also detectable in the adult rat brain. CD11b/c labelled microglial cells express aromatase, but the immunopositive signal was distributed only in the cytoplasm both in the ramified and amoeboid microglial forms. Immunostaining of rat ovarian tissue sections and human granulosa cells revealed that aromatase was present only in the cytoplasm. This novel observation suggests a new unique mechanism in astrocytes that may regulate certain CNS functions via estradiol production.
雌激素调节多种神经内分泌、生殖和非生殖脑功能。中枢神经系统 (CNS) 中的雌二醇生物合成由芳香酶催化，神经元、星形胶质细胞和小胶质细胞在几个脑区表达芳香酶。在这项研究中，我们进行了复杂的荧光免疫细胞化学分析，结果显示芳香酶与胶质纤维酸性蛋白 (GFAP) 阳性星形胶质细胞中的核染色剂共定位。共聚焦免疫荧光 Z -stack 扫描分析证实了芳香酶与核 DAPI 信号的共定位。核芳香酶也可在 S100β 阳性星形胶质细胞亚群中检测到。当存在核芳香酶信号时，核雌激素受体 α 也丰富存在于核内。冷冻脑组织切片的免疫染色显示，GFAP 阳性星形胶质细胞中酶的核共定位在成年大鼠脑中也可检测到。CD11b/c 标记的小胶质细胞表达芳香酶，但免疫阳性信号仅分布在有分支和阿米巴样形态的小胶质细胞的细胞质中。对大鼠卵巢组织切片和人颗粒细胞的免疫染色显示，芳香酶仅存在于细胞质中。这一新颖的观察结果表明，星形胶质细胞中存在一种新的独特机制，可能通过雌二醇的产生来调节某些 CNS 功能。
