Mitochondrial Involvement in Synaptic Dysfunction During Aging and AD

项目总结（见说明）：在之前的资助期间，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，在正常的大脑衰老和阿尔茨海默病中，生物能量危机是由线粒体结构、功能和活动功能障碍引起的，这些功能障碍导致突触完整性的破坏，从而导致认知能力下降，这是衰老和阿尔茨海默病的特征。目前这项拨款的延续将进一步评估雌激素对线粒体影响的机制，并确定这些影响是否发生在体内和死后的女性样本中。我们将解决4个具体目标。特异性目的1将确定PKA/DRP1通路的药理学拮抗或遗传减少是否会导致突触完整性丧失、线粒体分裂和不动，以及初级海马神经元的生物能量下降。特异性目标2将确定卵巢切除2周、12周或20周是否会损害PKA/DRP1通路，导致突触丧失和线粒体功能障碍，以及这些缺陷是否可以通过E2、ER(3)激动剂、DPN或P4治疗6周在体内恢复。特异性Aim 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。特异性Aim 4将确定DPN治疗是否能改善PKA/DRP1通路功能，从而改善5XFAD小鼠模型中出现的突触完整性丧失、线粒体不动和碎片化。为了达到所有的目的，我们将评估DRPI的磷酸化状态，一组突触前和突触后标记，以及一组生物能量测量。对于目标1和目标4，我们将对线粒体分裂和迁移进行详细的评估。这些研究的成功完成可能会导致对大脑中雌激素靶点的新认识，以及与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.