Department of Molecular and Cellular Neurobiology, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan.
Biochem Biophys Res Commun. 2013 Nov 15;441(2):327-32. doi: 10.1016/j.bbrc.2013.10.046. Epub 2013 Oct 23.
Thermosensitive transient receptor potential (thermo TRP) channels are important for sensory transduction. Among them, TRPV2 has an interesting characteristic of being activated by very high temperature (>52 °C). In addition to the heat sensor function, TRPV2 also acts as a mechanosensor, an osomosensor and a lipid sensor. It has been reported that TRPV2 is expressed in heart, intestine, pancreas and sensory nerves. In the central nervous system, neuronal TRPV2 expression was reported, however, glial expression and the precise roles of TRPV2 have not been determined. To explore the functional expression of TRPV2 in astrocytes, the expression was determined by histological and physiological methods. Interestingly, TRPV2 expression was detected in plasma membrane of astrocytes, and the astrocytic TRPV2 was activated by very high temperature (>50 °C) consistent with the reported characteristic. We revealed that the astrocytic TRPV2 was also activated by lysophosphatidylcholine, a known endogenous lipid ligand for TRPV2, suggesting that astrocytic TRPV2 might regulate neuronal activities in response to lipid metabolism. Thus, for the first time we revealed that TRPV2 is functionally expressed in astrocytes in addition to neurons.
热敏瞬时受体电位 (thermo TRPV) 通道对于感觉转导很重要。其中,TRPV2 的一个有趣特征是可以被非常高的温度(>52°C)激活。除了热传感器功能外,TRPV2 还充当机械传感器、渗透压传感器和脂质传感器。已经报道 TRPV2 在心脏、肠、胰腺和感觉神经中表达。在中枢神经系统中,报道了神经元 TRPV2 的表达,然而,胶质细胞的表达和 TRPV2 的精确作用尚未确定。为了研究 TRPV2 在星形胶质细胞中的功能表达,通过组织学和生理学方法确定了表达情况。有趣的是,TRPV2 表达在星形胶质细胞膜上,并且星形胶质细胞的 TRPV2 被非常高的温度(>50°C)激活,与报道的特征一致。我们揭示了星形胶质细胞的 TRPV2 也被溶血磷脂酰胆碱激活,溶血磷脂酰胆碱是 TRPV2 的已知内源性脂质配体,表明星形胶质细胞的 TRPV2 可能会响应脂质代谢调节神经元活动。因此,我们首次揭示了 TRPV2 除了在神经元中外,还在星形胶质细胞中具有功能性表达。