Immunoreactivity of receptor and transporters for lactate located in astrocytes and epithelial cells of choroid plexus of human brain
Immunoreactivity of receptor and transporters for lactate located in astrocytes and epithelial cells of choroid plexus of human brain
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DOI：
10.1016/j.neulet.2020.135479
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发表时间：
2021-01-10
影响因子：
2.5
通讯作者：
Ueno，Masaki
中科院分区：
文献类型：
--
作者：
Murakami，Ryuta;Chiba，Yoichi;Ueno，Masaki
葡萄糖代谢在厌氧环境中产生乳酸和氢离子。脑缺血或缺氧被认为是渐进性乳酸血症。内皮细胞中的单羧酸转运体(MCTs)对于乳酸从血液到大脑的运输是必不可少的。此外，星形胶质细胞和神经细胞中的MCT在能量代谢产物在神经元和星形胶质细胞之间的穿梭中起着关键作用。然而，乳酸在大脑中的作用仍有待澄清。在这项研究中，乳酸转运体和细胞摄取乳酸的受体在尸检的人脑中进行了免疫组织化学检测。MCT1在脉络丛部分上皮细胞、星形胶质细胞和毛细血管壁的顶端胞质膜上呈阳性反应，而MCT4在少数上皮细胞、星形胶质细胞和毛细血管壁的基底外侧胞膜上呈免疫反应阳性。此外，细胞摄取乳酸的受体--羟基羧酸1受体(HCA1受体)在上皮细胞、星形胶质细胞和神经细胞的基侧细胞膜上也有免疫反应。在脉络丛上皮细胞、星形胶质细胞和毛细血管壁上皮细胞胞浆中观察到乳酸脱氢酶B的免疫反应。这些免疫组织化学结果提示MCT1、MCT4、HCA1受体和LDH-B在脉络丛上皮细胞和星形胶质细胞中的定位，并提示血管内乳酸通过脉络丛上皮细胞和脑血管运输到脑内，以及乳酸被用于上皮细胞的可能性。
Glucose metabolism produces lactate and hydrogen ions in an anaerobic environment. Cerebral ischemia or hypoxia is believed to become progressively lactacidemic. Monocarboxylate transporters (MCTs) in endothelial cells are essential for the transport of lactate from the blood into the brain. In addition, it is considered that MCTs located in astrocytic and neuronal cells play a key role in the shuttling of energy metabolites between neurons and astrocytes. However, roles of lactate in the brain remain to be clarified. In this study, the localization of lactate transporters and a receptor for cellular uptake of lactate was immunohistochemically examined in autopsied human brains. Immunoreactivity for MCT1 was observed in the apical cytoplasmic membrane of some epithelial cells in the choroid plexus as well as astrocytes and the capillary wall, whereas that for MCT4 was found in the basolateral cytoplasmic membrane of small number of epithelial cells as well as astrocytes and the capillary wall. In addition, immunoreactivity for the hydroxy-carboxylic acid 1 receptor (HCA1 receptor), a receptor for cellular uptake of lactate, was also found on the basolateral cytoplasmic membrane of epithelial cells as well as astrocytic and neuronal cells. Immunoreactivity for lactate dehydrogenase (LDH)-B was observed in the cytoplasm of epithelial cells in the choroid plexus as well as astrocytes and the capillary wall.These immunohistochemical findings indicate the localization of MCT1, MCT4, the HCA1 receptor, and LDH-B in epithelial cells of the choroid plexus as well as astrocytes, and suggest the transport of intravascular lactate into the brain through epithelial cells of the choroid plexus as well as cerebral vessels and the possibility of lactate being utilized in epithelial cells.