Mitochondrial Involvement in Synaptic Dysfunction During Aging and AD

项目摘要(见说明)：在前一次供资期间，我们就雌激素对线粒体的作用机制进行了一些基本观察，以指导本提案的目标。我们有证据表明，在正常脑老化和AD期间出现的生物能量危机是由线粒体结构、功能和运动障碍引起的，线粒体结构、功能和运动障碍导致突触完整性崩溃，导致认知能力下降，这是衰老和AD的特征。目前这项资助的延续将进一步评估雌激素对线粒体的影响机制(S)，并确定这些影响是否发生在体内和女性的身体样本中。我们将解决4个具体目标。具体目的1将确定PKA/Drp1通路的药理拮抗或遗传减少是否导致原代海马神经元突触完整性丧失、线粒体分裂和静止以及生物能量下降。具体目标2将确定卵巢切除2周、12周或20周是否损害了PKA/DRp1途径，导致突触丢失和线粒体功能障碍，以及在体内，这些缺陷是否可以通过雌激素受体(ER)激动剂、DPN或P4治疗6周而恢复。具体目标3将确定年龄和卵巢切除后的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/Drp1途径功能，从而改善5XFAD小鼠模型中出现的突触完整性丧失、线粒体静止和碎裂。对于所有的目标，我们将评估DRPI的磷酸化状态，一组突触前和突触后的标志物，以及一组生物能量指标。对于目标1和目标4，我们将对线粒体碎裂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标的新理解，以及潜在的治疗与年龄相关的认知下降和AD的新疗法。

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.