Tau/P-Tau as Biomarkers of Anesthesia- and Surgery-Induced Cognitive Impairment in a Murine Model

 描述(申请人提供)：本R01申请已提交给资助机会公告(PAR-13-195)。每年有数以百万计的儿童接受手术和麻醉。最近的人口研究表明，在较小年龄接受麻醉和手术的儿童可能会增加患神经发育障碍(例如认知障碍)的风险。因此，迫切需要对这一新的和研究不足的领域进行研究：麻醉和手术导致的儿童认知障碍。然而，到目前为止，还没有开发出这种认知障碍的生物标记物。这种知识上的差距阻碍了这类研究的进展。因此，我们建议在小鼠模型中开发和验证生物标记物，这些生物标记物以后可以用来提供信息并有效地转化为儿童临床试验，以研究麻醉和手术导致的认知障碍。与磷酸化牛磺酸(P-Tau)和神经发生有助于认知功能的观点一致，我们的初步研究表明，麻醉剂七氟醚可以增加幼鼠脑内P-Tau的水平，抑制神经发生，导致认知障碍，并增加血液中的Tau水平。因此，我们假设血和尿中的Tau和P-Tau可作为麻醉和手术所致幼年小鼠认知障碍的生物标志物，P-Tau通过破坏神经前体细胞微管的稳定性来抑制其迁移。使用体外和体内的方法，以及创新的纳米生物传感器技术，我们将用三个具体的目标来验证我们的假设。在目标1中，我们将利用质谱学、Western印迹和纳米生物传感器技术来筛选和鉴定特定麻醉和手术后小鼠脑组织和脑脊液中Tau(可溶性和不溶性)和特异性P-Tau的升高。我们还将测定小鼠的相关认知功能。在目标2中，我们将利用纳米生物传感器技术显示麻醉和手术后小鼠血液和尿液中Tau和特异性P-Tau(与脑和脑脊液中相同)的升高。然后，在干预性验证研究中，我们将确定Tau的锂和敲除(KO)(使用Tau KO小鼠)是否可以减轻麻醉和手术所致的认知障碍，并减轻幼年小鼠血和尿中Tau和P-Tau的升高。在机制验证研究(AIM 3)中，我们将评估麻醉和手术引起的P-Tau增加是否会损害(体外)鼻咽癌细胞微管的稳定性，并减缓(体内和体外)鼻咽癌细胞的迁移。我们将确定Tau的锂和KO是否能挽救这些效应。换言之，该项目将为麻醉和手术导致的幼鼠认知障碍开发生物标记物，稍后可用于儿童。从科学上讲，该项目将阐明Tau影响NPC迁移的创新机制。该项目的结果最终将为儿童带来更安全的麻醉护理和更好的术后结果。

 DESCRIPTION (provided by applicant): This R01 application is submitted to the funding opportunity announcement (PAR-13-195). Millions of children have surgery and anesthesia each year. Recent population studies have suggested that children who undergo anesthesia and surgery at an earlier age could have an increased risk for neurodevelopment disabilities (e.g., cognitive impairment). It is therefore urgent to perform studies in this new and under-investigated area: anesthesia- and surgery-induced cognitive impairment in children. However, thus far, no biomarker of such cognitive impairment has been developed. This gap in knowledge impedes the progress of such research. Therefore, we have proposed to develop and validate biomarkers in mouse models that can later be used to inform and effectively translate to clinical trials in children to study anesthesia- and surgery-induced cognitive impairment. Consistent with the notion that phosphorylated Tau (P-Tau) and neurogenesis contribute to cognitive function, our Preliminary studies show that anesthetic sevoflurane can increase levels of brain P-Tau, inhibit neurogenesis, cause cognitive impairment and increase blood Tau levels in young mice. Therefore, we hypothesize that Tau and P-Tau in blood and urine serve as the biomarkers for anesthesia- and surgery-induced cognitive impairment in young mice, and P-Tau inhibits the migration of neural progenitor cells (NPCs) by de-stabilizing their microtubules. Using both in vitro and in vivo approaches, and the innovative nano biosensor technology, we will test our hypothesis with three Specific Aims. In Aim 1, we will use mass spectrometry, Western blot and nano biosensor technology to screen and then identify the elevation of Tau (soluble and insoluble) and specific P-Tau in mouse brain tissues and cerebrospinal fluid (CSF) following the particular anesthesia and surgery. We will also determine the associated cognitive function in the mice. In Aim 2, we will use nano biosensor technology to show that there is elevation of Tau and specific P-Tau (same as those in the brain and CSF) in the blood and urine following the anesthesia and surgery in mice. Then, in the interventional validation studies, we will determine whether lithium and knockout (KO) of Tau (employing Tau KO mice) can mitigate the anesthesia- and surgery-induced cognitive impairment, and attenuate the elevation of Tau and P-Tau in the blood and urine of young mice. In the mechanistic validation studies (Aim 3), we will assess whether anesthesia- and surgery-induced increases in P-Tau will damage microtubule stability of the NPCs (in vitro) and slow down the NPCs migration (in vivo and in vitro). We will determine whether lithium and KO of Tau can rescue these effects. Translationally, this project would develop biomarkers for anesthesia- and surgery-induced cognitive impairment in young mice, which could later be used in children. Scientifically, this project would elucidate an innovative mechanism by which Tau affects NPCs migration. The results of this project would ultimately lead to safer anesthesia care and better postoperative outcomes for children.