皮质星形胶质细胞中神经胶质递质的胞吐作用:对突触可塑性和衰老的影响。
Exocytosis of gliotransmitters from cortical astrocytes: implications for synaptic plasticity and aging.
作者信息
Lalo Ulyana, Rasooli-Nejad Seyed, Pankratov Yuriy
机构信息
*School of Life Sciences, University of Warwick, Coventry CV4 7AL, U.K.
出版信息
Biochem Soc Trans. 2014 Oct;42(5):1275-81. doi: 10.1042/BST20140163.
Maintaining brain function during aging is very important for mental and physical health. Recent studies showed a crucial importance of communication between two major types of brain cells: neurons transmitting electrical signals, and glial cells, which maintain the well-being and function of neurons. Still, the study of age-related changes in neuron-glia signalling is far from complete. We have shown previously that cortical astrocytes are capable of releasing ATP by a quantal soluble N-ethylmaleimide-sensitive factor-attachment protein receptor (SNARE) complex-dependent mechanism. Release of ATP from cortical astrocytes can be activated via various pathways, including direct UV-uncaging of intracellular Ca²⁺ or G-protein-coupled receptors. Importantly, release of both ATP and glutamate from neocortical astrocytes was not observed in brain slices of dominant-negative SNARE (dnSNARE) mice, expressing dnSNARE domain selectively in astrocytes. We also discovered that astrocyte-driven ATP can cause significant attenuation of synaptic inhibition in the pyramidal neurons via Ca²⁺-interaction between the neuronal ATP and γ-aminobutyric acid (GABA) receptors. Furthermore, we showed that astrocyte-derived ATP can facilitate the induction of long-term potentiation of synaptic plasticity in the neocortex. Our recent data have shown that an age-related decrease in the astroglial Ca²⁺ signalling can cause a substantial decrease in the exocytosis of gliotransmitters, in particular ATP. Age-related impairment of ATP release from cortical astrocytes can cause a decrease in the extent of astroglial modulation of synaptic transmission in the neocortex and can therefore contribute to the age-related impairment of synaptic plasticity and cognitive decline. Combined, our results strongly support the physiological relevance of glial exocytosis for glia-neuron communications and brain function.
在衰老过程中维持大脑功能对身心健康非常重要。最近的研究表明,两种主要类型的脑细胞之间的通讯至关重要:传递电信号的神经元和维持神经元健康与功能的神经胶质细胞。然而,对神经元 - 神经胶质细胞信号传导中与年龄相关变化的研究仍远未完成。我们之前已经表明,皮质星形胶质细胞能够通过一种依赖于量子可溶性N - 乙基马来酰亚胺敏感因子附着蛋白受体(SNARE)复合体的机制释放ATP。皮质星形胶质细胞释放ATP可通过多种途径激活,包括细胞内Ca²⁺的直接紫外线解笼或G蛋白偶联受体。重要的是,在显性负性SNARE(dnSNARE)小鼠的脑片中未观察到新皮质星形胶质细胞释放ATP和谷氨酸,dnSNARE小鼠在星形胶质细胞中选择性表达dnSNARE结构域。我们还发现,星形胶质细胞驱动的ATP可通过神经元ATP与γ - 氨基丁酸(GABA)受体之间的Ca²⁺相互作用,显著减弱锥体神经元中的突触抑制。此外,我们表明星形胶质细胞衍生的ATP可促进新皮质中突触可塑性的长时程增强的诱导。我们最近的数据表明,与年龄相关的星形胶质细胞Ca²⁺信号传导的减少可导致神经胶质递质,特别是ATP的胞吐作用大幅下降。皮质星形胶质细胞ATP释放的与年龄相关的损伤可导致新皮质中星形胶质细胞对突触传递的调节程度降低,因此可能导致与年龄相关的突触可塑性损伤和认知衰退。综合来看,我们的结果有力地支持了神经胶质细胞胞吐作用对神经胶质细胞 - 神经元通讯和大脑功能的生理相关性。