Norepinephrine transporter expression in cholinergic sympathetic neurons: differential regulation of membrane and vesicular transporters.
Norepinephrine transporter expression in cholinergic sympathetic neurons: differential regulation of membrane and vesicular transporters.
复制标题
胆碱能交感神经元去甲肾上腺素转运蛋白的表达：膜和囊泡转运蛋白的差异调节。
DOI：
10.1006/dbio.2000.9631
复制
发表时间：
2000
影响因子：
2.7
通讯作者：
Packard,BA
中科院分区：
文献类型：
--
作者：
Habecker,BA;Klein,MG;Cox,BC;Packard,BA
交感神经元经历去甲肾上腺素能到胆碱能的表型变化，为研究合成、储存或移除特定神经递质所需蛋白质的发育调节提供了一个有用的模型系统。这种类型的变化发生在交感汗腺神经支配的发育过程中，可以通过含有汗腺的足垫提取物或白血病抑制因子在培养的交感神经元中诱导。交感神经元最初产生去甲肾上腺素(NE)，并含有囊泡性单胺转运体2(VMAT2)和去甲肾上腺素转运体(NET)，前者将NE包装成小泡，后者将NE从突触间隙中移除以终止信号传递。我们使用了各种生化和分子技术来测试VMAT2和Net在交感神经元中的水平是否降低，交感神经元停止产生NE并产生乙酰胆碱。在培养的交感神经细胞中，净蛋白和mRNA在向胆碱能表型转变的过程中下降，但VMAT2的mRNA和蛋白没有下降。体内发育中的汗腺神经支配的净免疫反应性消失，因为它获得了胆碱能特性。令人惊讶的是，Net同时出现在汗腺肌上皮细胞中。肌上皮细胞中Net的存在不需要交感神经支配。VMAT2水平并没有随着汗腺神经支配的胆碱能而降低，表明NE合成和囊泡包装在这个系统中没有耦合。因此，去甲肾上腺素的产生和去甲肾上腺素能传递所需的转运体在胆碱能发育过程中不受协调调节。
Sympathetic neurons that undergo a noradrenergic to cholinergic change in phenotype provide a useful model system to examine the developmental regulation of proteins required to synthesize, store, or remove a particular neurotransmitter. This type of change occurs in the sympathetic sweat gland innervation during development and can be induced in cultured sympathetic neurons by extracts of sweat gland-containing footpads or by leukemia inhibitory factor. Sympathetic neurons initially produce norepinephrine (NE) and contain the vesicular monoamine transporter 2 (VMAT2), which packages NE into vesicles, and the norepinephrine transporter (NET), which removes NE from the synaptic cleft to terminate signaling. We have used a variety of biochemical and molecular techniques to test whether VMAT2 and NET levels decrease in sympathetic neurons which stop producing NE and make acetylcholine. In cultured sympathetic neurons, NET protein and mRNA decreased during the switch to a cholinergic phenotype but VMAT2 mRNA and protein did not decline. NET immunoreactivity disappeared from the developing sweat gland innervation in vivo as it acquired cholinergic properties. Surprisingly, NET simultaneously appeared in sweat gland myoepithelial cells. The presence of NET in myoepithelial cells did not require sympathetic innervation. VMAT2 levels did not decrease as the sweat gland innervation became cholinergic, indicating that NE synthesis and vesicular packaging are not coupled in this system. Thus, production of NE and the transporters required for noradrenergic transmission are not coordinately regulated during cholinergic development.