Estradiol targets synaptic proteins to induce glutamatergic synapse formation in cultured hippocampal neurons:: Critical role of estrogen receptor-α
Estradiol targets synaptic proteins to induce glutamatergic synapse formation in cultured hippocampal neurons:: Critical role of estrogen receptor-α
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DOI：
10.1523/jneurosci.0909-07.2007
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发表时间：
2007-06-27
影响因子：
5.3
通讯作者：
Wise, Phyllis
中科院分区：
文献类型：
--
作者：
Jelks, Karen Bozak;Wylie, Rebecca;Wise, Phyllis
雌二醇介导海马体突触的结构变化，海马体是大脑中对学习和记忆至关重要的区域。本研究旨在验证雌激素通过雌激素受体(ER)介导突触蛋白亚细胞变化以诱导新突触的假说。为了阐明谷氨酸能突触形成的机制，我们用免疫细胞化学和共聚焦显微镜观察了雌二醇对培养的海马神经元突触蛋白的影响。用突触前囊泡谷氨酸转运蛋白(VGlut1)和突触后NMDA受体(NR1亚单位)抗体鉴定突触蛋白的分布和大小。我们观察到NR1和vGlut1共同定位的突触密度增加，在去类固醇的培养液中培养的神经元的树突上，雌二醇(10 NM)作用48h。此外，NR1亚单位在突触簇处丰富。免疫细胞化学和共聚焦成像显示，表达NR1的海马神经元的树突上可见核外内质网点状染色。雌激素增加了ER-α和ER-β蛋白簇沿树突的密度。为了测试雌激素受体是否在雌激素诱导的突触形成中发挥重要作用，我们使用了雌激素受体拮抗剂[7α，17β[9[(4，4，5，5，5-五氟戊基)亚磺基]壬基]雌二醇-1，3，5(10)-三烯-3，17-二醇(ICI182,780)以及ER-α和ER-β特异性激动剂[1，3，5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole和2，3-双(4-羟基苯基)丙腈。ICI 182,780阻断了突触密度的增加。用PPT处理，而不是DPN，诱导突触密度显著增加，这类似于用雌二醇处理。总之，我们的结果表明，雌激素通过ER-α依赖的机制刺激发育中的海马区谷氨酸能突触的形成。这些发现对雌激素影响学习、记忆以及可能的激素调节的神经退化的潜力具有深远的影响。
Estradiol mediates structural changes at synapses of the hippocampus, an area in the brain important for learning and memory. This study was designed to test the hypothesis that estradiol mediates subcellular changes of synaptic proteins to induce new synapses via an estrogen receptor (ER)- mediated process. To elucidate the mechanisms involved in glutamatergic synapse formation, we investigated effects of estradiol on synaptic proteins in cultured hippocampal neurons using immunocytochemistry and confocal microscopy. Synaptic protein distribution and size were identified with antibodies to the presynaptic vesicular glutamate transporter protein (vGlut1) and postsynaptic NMDA receptor (NR1 subunit). We observed an increase in synapse density, as detected by NR1 and vGlut1 colocalization, along dendrites of neurons cultured in steroid- stripped media and exposed to estradiol (10 nM) for 48 h. Additionally, the NR1 subunit was enriched at synaptic clusters. Immunocytochemistry and confocal imaging revealed punctate staining of extranuclear ERs along dendrites of hippocampal neurons expressing NR1. Estradiol increased the density of both ER-alpha and ER- beta protein clusters along dendrites. To test whether ERs play an important functional role in the estradiol- induced synaptogenesis, we used the ER antagonist [7 alpha, 17 beta-[9[( 4,4,5,5,5-pentafluoropentyl) sulfinyl] nonyl] estra-1,3,5( 10)-triene-3,17-diol (ICI 182,780)] and the ER-alpha- and ER-beta-specific agonists [1,3,5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT) and 2,3-bis(4-hydroxyphenyl) propionitrile (DPN), respectively]. ICI 182,780 blocked the increase in synapse density. Treatment with PPT, but not DPN, induced significant increases in synapse density that mimicked treatment with estradiol. Together, our results demonstrate that estradiol stimulates glutamatergic synapse formation in the developing hippocampus through an ER-alpha-dependent mechanism. These findings carry profound implications regarding the potential of estrogen to influence learning, memory, and possibly hormone-modulated neurodegeneration.