Mitochondrial Involvement in Synaptic Dysfunction During Aging and AD

项目摘要（见说明）：在上一个资助期，我们对雌激素对线粒体的作用机制进行了一些基本观察，这些观察指导了本提案的目标。我们有证据表明，在正常脑老化和AD中观察到的生物能量危机是由线粒体结构、功能和运动功能障碍引起的，线粒体结构、功能和运动功能障碍导致突触完整性的破坏，从而导致认知能力下降，这是衰老和AD的特征。目前继续这项赠款将进一步评估雌激素对线粒体的作用机制，并确定这些作用是否发生在体内和妇女的死后样本中。我们将实现四个具体目标。具体目标1将确定PKA/DRP 1通路中的药理学拮抗作用或遗传减少是否导致突触完整性丧失、线粒体分裂和不动性以及原代海马神经元中的生物能下降。具体目标2将确定卵巢切除术2、12或20周是否损害PKA/DRP 1通路，导致突触丢失和线粒体功能障碍，以及这些缺陷是否可以通过E2、ER β激动剂、DPN或P4治疗6周在体内恢复。具体目标3将确定年龄和卵巢切除术后持续时间是否会改变突触神经体对E2、DPN或P4的反应。具体目标4将确定DPN治疗是否改善PKA/DRP 1通路功能，从而改善5XFAD小鼠模型中观察到的突触完整性、线粒体不动性和片段化的丧失。为了实现所有目标，我们将评估DRPI磷酸化状态、一组突触前和突触后标记物以及一组生物能量指标。对于目标1和4，我们将对线粒体碎片化和流动性进行详细评估。成功完成这些拟议的研究可能会导致对大脑中雌激素靶点的新理解，以及对年龄相关的认知衰退和AD的潜在新疗法。

PROJECT SUMMARY (See instructions): During the previous funding period, we made a number of fundamental observations relative to the mechanism of action of estrogens on mitochondria that guide the aims of the present proposal. We have evidence that the bioenergetic crisis seen during normal brain aging and in AD is caused by mitochondrial structure, function and mobility dysfunctions that leads to a breakdown in synaptic integrity resulting in cognitive decline that characterizes both aging and AD. The present continuation of this grant will further assess the mechanism(s) of effects of estrogens on mitochondria and determine if these effects occur in vivo and in post-mortem samples from women. We will address 4 specific aims. Specific Aim 1 will determine if pharmacological antagonism or genetic reduction in the PKA/DRP1 pathway leads to a loss of synaptic integrity, mitochondrial fission and immobility, and bioenergetic decline in primary hippocamal neurons. Specific Aim 2 will determine if ovariectomy for 2, 12 or 20 weeks compromises the PKA/DRP1 pathway leading to synaptic loss and mitochondrial dysfunction and if these deficits can be restored by E2, an ER(3 agonist, DPN, or P4 treatment for 6 weeks, in vivo. Specific Aim 3 will determine if age and post-ovariectomy duration, changes the synaptoneurosome response to E2, DPN or P4. Specific Aim 4 will determine if therapy with DPN improves PKA/DRP1 pathway function, thereby ameliorating loss of synaptic integrity, mitochondrial immobility and fragmentation seen in a 5XFAD mice model. For all of the aims, we will assess DRPI phosphorylation state, a panel of pre- and post-synaptic markers, and a panel of bioenergetic measures. For aims 1 and 4, we will conduct a detailed assessment of mitochnodrial fragmentation and mobility. Successful completion of these proposed studies could lead to new understanding of estrogen targets in the brain as well as potential new therapies for age-related cognitive decline and AD.