School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, United Kingdom.
Glia. 2018 Jun;66(6):1176-1184. doi: 10.1002/glia.23303. Epub 2018 Feb 7.
Studies from a number of areas of neuroendocrinology indicate that hypothalamic tanycytes play a key role in control of energy metabolism. First, profound annual changes in gene expression have been identified in these unusual glial cells in seasonal mammals, for example in genes relating to the transport and metabolism of thyroid hormone into the hypothalamus. The consequent changes in local thyroid hormone availability in the hypothalamus have been shown experimentally to regulate annual cycles in energy intake, storage and expenditure in seasonal species. This is reflected in overt seasonal changes in appetite, body fat composition and torpor. Second, studies in laboratory rodents demonstrate that hypothalamic tanycytes possess transport mechanisms and receptors that indicate they have a cellular function as nutrient sensors. Ex vivo studies with organotypic tanycyte cultures confirm that acute changes in nutrient availability alter calcium and purinergic signalling within and between tanycytes. Finally, tanycytes are components of a stem cell niche in the hypothalamus whose activity can be regulated by the nutritional environment. Experimental depletion of cell division in the hypothalamus alters the homeostatic response to nutrient excess in mice raised in high fat diets. These convergent lines of evidence suggest that tanycytes are nutrient and metabolite sensors that impact upon plasticity and neuronal function in the surrounding hypothalamus, and consequently have an important role in energy intake and expenditure.
神经内分泌学的多个领域的研究表明，下丘脑的室管膜细胞在控制能量代谢方面发挥着关键作用。首先，在季节性哺乳动物中，这些不寻常的神经胶质细胞中已经确定了深刻的年度基因表达变化，例如与甲状腺激素向下丘脑转运和代谢相关的基因。实验表明，下丘脑局部甲状腺激素可用性的变化调节了季节性物种的能量摄入、储存和消耗的年度周期。这反映在明显的季节性食欲、体脂肪组成和昏睡变化上。其次，实验室啮齿动物的研究表明，下丘脑的室管膜细胞具有运输机制和受体，表明它们具有作为营养传感器的细胞功能。器官型室管膜细胞培养的离体研究证实，营养物质可用性的急性变化会改变室管膜细胞内和室管膜细胞之间的钙和嘌呤能信号。最后，室管膜细胞是下丘脑干细胞龛的组成部分，其活性可以通过营养环境进行调节。在高脂肪饮食中饲养的小鼠中，通过实验耗尽下丘脑的细胞分裂会改变对营养过剩的稳态反应。这些相互一致的证据表明，室管膜细胞是营养物质和代谢物的传感器，影响周围下丘脑的可塑性和神经元功能，因此在能量摄入和消耗方面发挥着重要作用。
