Gene Therapy, Stress and Hippocampal Function

描述（由申请人提供）：海马体的突触可塑性、在认知中的作用以及发生在成人海马体中的神经发生已被研究。与此同时，人们对海马功能的内分泌调节剂也有了新的认识。具体来说，应激时分泌的肾上腺激素糖皮质激素（GCs）会破坏突触可塑性和认知功能，并抑制神经发生。相反，雌激素可以增强可塑性、认知和神经发生。在利用病毒载体将转基因传递到中枢神经系统方面也取得了进展。我们将在基因治疗策略中使用单纯疱疹病毒-1载体来保护海马免受GC和应激的破坏性影响，并将一些GC影响转化为有益的雌激素效应。我们已经构建并希望探索表达a)降解GCs的酶的载体的保护潜力；b)显性GC阴性受体；c)结合GCs的嵌合类固醇受体，但具有雌激素受体的基因组作用。在Aim 1中，我们将改变这些载体，使它们能够被应激和GCs诱导，作为一种手段，使它们的表达被侮辱触发。然后我们将描述他们的表达方式。然后，我们将检查这些载体的保护潜力，检查前两个备用神经元是否受到不利的GC效应，以及嵌合载体在暴露于GC时是否也产生有益的雌激素效应。在Aim 2中，终点将是死前不同GC暴露或应激机制的大鼠海马切片的长期增强。在目标3中，我们将研究GCs，压力和这些载体对海马依赖性认知任务的影响。在aims 4中，我们将研究体外和成人海马中的神经发生。我们将描述GCs，应激和雌激素对其的影响。然后，我们将确定这些载体是否可以保护神经发生免受GCs的抑制作用，并且在嵌合载体的情况下，利用这一点产生刺激性雌激素作用。

DESCRIPTION (provided by applicant): The hippocampus has been studied for its synaptic plasticity, role in cognition, and the neurogenesis that occurs in the adult hippocampus. With this has come an appreciation of endocrine modulators of hippocampal function. Specifically, glucocorticoids (GCs), adrenal steroids secreted during stress, disrupt [or] impair facets of synaptic plasticity and cognition, and inhibit neurogenesis. Estrogen, in contrast, enhances plasticity, cognition and neurogenesis. There has also been progress in the use of viral vectors to deliver transgenes into the CNS. We will use herpes simplex virus-1 vectors in a gene therapy strategy to protect the hippocampus from the disruptive effects of GCs and of stress, and to divert some of those GC effects into salutary estrogenic ones. We have constructed and wish to explore the protective potential of vectors expressing a) an enzyme which degrades GCs; b) a dominant negative GC receptor; c) a chimeric steroid receptor which binds GCs but has the genomic actions of an estrogen receptor. In Aim 1, we will alter these vectors to make them inducible by stress and GCs, as a means to have their expression triggered by insults. We will then characterize their patterns of expression. We will then examine the protective potential of these vectors, examining if the first two spare neurons from adverse GC effects, and if the chimeric vector also generates the salutary estrogenic effects when exposed to GCs. In Aim 2, the endpoint will be long-term potentiation in hippocampal slices generated from rats with differing pre-mortem regimes of GC exposure or stress. In Aim 3, we will study the effects of GCs, stress, and these vectors upon a hippocampal-dependent cognitive task. In Aim 4, we will study neurogenesis in vitro and in the adult hippocampus. We will characterize the effects of GCs, stress and estrogen upon it. We will then determine whether these vectors can protect neurogenesis from the inhibitory effects of GCs and, in the case of the chimeric vector, harness this to produce stimulatory estrogenic effects.