Differential roles of neuronal and astrocytic aromatase in status epilepticus and chronic epilepsy

项目摘要 雌激素和癫痫之间的关系长期以来一直被认为是雌激素，如雌二醇， 主要与致惊厥作用有关传统上，卵巢作为生殖器官的来源受到最多关注。 雌二醇，特别是在与某些雌二醇相关的月经性癫痫发作加重的情况下， 女性月经周期的主要阶段。然而，大脑本身是雌二醇的来源， 性别雌二醇是由睾酮通过芳香酶合成的，芳香酶在睾丸中高度表达。 大脑，特别是与癫痫密切相关的区域。在海马体中，芳香化酶几乎只 在基础条件下，星形胶质细胞在神经元中表达，但在创伤（如损伤或中风）后，星形胶质细胞也可以表达， 高水平的芳香化酶表达。脑源性雌二醇在癫痫中的作用，以及 神经元和星形胶质细胞作为雌二醇的来源在这种关系中，仍然不清楚。拟议的研究将 解决关于芳香化酶和雌激素合成的相对贡献的知识的主要差距， 神经元与星形胶质细胞与两种不同的癫痫发作活动状态有关：癫痫持续状态（SE）和慢性 癫痫，自发性反复发作的状态。我们的理由是，理解不同的作用， 神经元和星形胶质细胞在SE和癫痫的不同阶段作为雌激素的来源， 选择性靶向脑源性雌激素的产生并最大化癫痫发作的新治疗策略- 抑制作用，同时最大限度地减少对突触功能和记忆的有害影响。我们会用一本小说 转基因小鼠和芳香酶的受控细胞特异性减少的组合，与24小时 癫痫发作的视频脑电图监测、多标记免疫荧光显微镜检查和生化测量 海马雌二醇的含量来检验我们的总体假设，即神经元和星形胶质细胞具有不同的作用， SE和慢性癫痫中海马雌二醇的来源。在目标1中，我们将定义 海马神经元和星形胶质细胞芳香化酶表达与SE、癫痫发生和慢性 癫痫在目标2和3中，我们将确定海马神经元与星形胶质细胞芳香化酶在SE中的作用。 易感性和慢性癫痫。这些研究将使用一种小鼠癫痫模型， 概括了人类颞叶癫痫的几个关键EEG和组织病理学特征。这些研究 将通过提供对芳香酶表达动力学的新见解， 神经元和星形胶质细胞在SE和慢性癫痫，从而解决2020年NINDS的多个目标 癫痫研究基准，了解癫痫的原因和相关的神经系统疾病，以预防 癫痫的发展，并改善治疗方案，同时尽量减少副作用。

PROJECT SUMMARY A relationship between estrogens and epilepsy has long been acknowledged with estrogens, such as estradiol, primarily linked to proconvulsant effects. The ovaries traditionally receive the most attention as sources of estradiol, particularly in the context of catamenial seizure exacerbations in association with certain estradiol- dominant phases of the menstrual cycle in women. However, the brain itself is a source of estradiol in both sexes. Estradiol is synthesized from testosterone by the aromatase enzyme, which is highly expressed in the brain, particularly in areas strongly implicated in epilepsy. In the hippocampus, aromatase is almost exclusively expressed in neurons in basal conditions, but after trauma such as injury or stroke, astrocytes can also show high levels of aromatase expression. Roles for brain-derived estradiol in epilepsy, and the specific roles of neurons and astrocytes as sources of estradiol in this relationship, remain unclear. The proposed research will address major gaps in knowledge regarding the relative contributions of aromatase and estrogen synthesis in neurons vs. astrocytes in relation to two distinct states of seizure activity: status epilepticus (SE) and chronic epilepsy, the state of spontaneous recurrent seizures. Our rationale is that understanding distinct roles of neurons and astrocytes as sources of estrogens at different phases of SE and epilepsy will enable development of new therapeutic strategies to selectively target production of brain-derived estrogens and maximize seizure- suppressive effects, while minimizing deleterious effects on synaptic function and memory. We will use a novel combination of transgenic mice and controlled cell-specific reduction of aromatase, in combination with 24-hour video-EEG monitoring of seizures, multilabel immunofluorescence microscopy, and biochemical measurement of hippocampal estradiol to test our overall hypothesis that neurons and astrocytes have differential roles as sources of hippocampal estradiol in SE and chronic epilepsy. In Aim 1, we will define the temporal dynamics of hippocampal neuronal and astrocytic aromatase expression in association with SE, epileptogenesis, and chronic epilepsy. In Aims 2 and 3, we will determine the roles of hippocampal neuronal vs. astrocytic aromatase in SE susceptibility and chronic epilepsy, respectively. These studies will use a mouse model of epilepsy that recapitulates several critical EEG and histopathological features of human temporal lobe epilepsy. These studies will have positive translational impact by providing new insights into the dynamics of aromatase expression in neurons and astrocytes in SE and chronic epilepsy, and thereby address multiple goals of the 2020 NINDS Epilepsy Research Benchmarks to understand causes of epilepsy and related neurologic conditions, to prevent the progression of epilepsy, and improve treatment options while minimizing side effects.