Blood Brain Barrier Changes Induced by Pain

描述（由申请人提供）：疼痛每年折磨超过1.16亿美国人，估计花费6350亿美元用于医疗和生产力损失。疼痛（急性/术后和慢性）的治疗通常涉及阿片类镇痛药。我们已经表明，外周炎性疼痛（PIP）促进BBB功能障碍，其特征在于外排转运蛋白和紧密连接（TJ）蛋白的表达和定位的变化以及增加的细胞旁通透性（即，泄漏）。这些变化的临床相关性改变了阿片类镇痛药的脑摄取。 在这次更新中，我们提出了一个新的假设，即PIP期间的BBB功能障碍，改变了细胞旁通透性和阿片类镇痛药的CNS递送，可以通过治疗靶向病理诱导的P-糖蛋白（Pgp）和TJ蛋白封闭蛋白和封闭蛋白的运输变化来调节，这些变化对TJ寡聚蛋白组装体的形成和完整性至关重要。两个具体目标将 测试这个假设。 目的1：确定PIP诱导的Pgp转运变化如何导致Pgp药物外排活性增加。在这个目标中，我们将确定从脑微血管中分离的Pgp储存室的组分（目标1A）。我们还将在1-72小时的时间过程中（一次性或再激发）将Pgp阿片类药物外排活性的变化与Pgp转运的变化相关联（目的1B）。由于活性氧（ROS）的产生是疼痛/炎症的关键成分，我们将评估施用TEMPOL（即，4-羟基-2，2，6，6-四甲基哌啶-N-氧基）（一种ROS清除剂）对Pgp运输以及阿片类药物在1-72小时PIP时间过程中的脑摄取和镇痛功效的影响（一次性或再激发）（目的1C）。 目的2：研究PIP诱导的TJ蛋白运输变化如何调节细胞旁血脑屏障通透性。在这个目标中，我们将确定与从脑微血管中分离的TJ相关的蛋白质（Aim 2A）。我们还将细胞旁BBB通透性的变化与蛋白质-蛋白质相互作用的变化相关联，所述蛋白质-蛋白质相互作用导致在PIP的1-72小时时间过程中闭合蛋白和密蛋白的细胞内运输的变化（一次击中或再激发）（Aim 2B）。然后，我们将评估TEMPOL施用对闭合蛋白/密蛋白运输、对可待因的BBB细胞旁渗透性和在PIP的1-72小时时程内的可待因功效（一次击中或再激发）的影响。(Aim 2C）。 我们在此更新的目标是发现新的治疗靶点，通过定义蛋白质运输在促进BBB结构/功能变化中的作用来治疗疼痛和疼痛诱导的BBB功能障碍，从而导致PIP期间CNS药物递送的改变。

DESCRIPTION (provided by applicant): Pain afflicts over 116 million Americans annually and costs an estimated $635 billion dollars in medical treatments and lost productivity. The treatment of pain (both acute/post-surgical and chronic) often involves opioid analgesics. We have shown that peripheral inflammatory pain (PIP) promotes BBB dysfunction characterized by changes in expression and localization of efflux transporter and tight junction (TJ) proteins as well as increased paracellular permeability (i.e., leak). The clinical relevance of these changes i altered brain uptake of opioid analgesics. In this renewal, we propose to test the novel hypothesis that BBB dysfunction during PIP, which alters paracellular permeability and CNS delivery of opioid analgesics, can be modulated by therapeutic targeting of pathology-induced changes in trafficking of P- glycoprotein (Pgp) and of TJ proteins occludin and claudins that are critical to the formation and integrity of TJ oligomeric protein assemblies. Two specific aims will test this hypothesis. Aim 1: To determine how PIP-induced changes in Pgp trafficking result in increased Pgp drug efflux activity. In this aim, we will identify components of Pgp storage compartment(s) isolated from cerebral microvessels (Aim 1A). We will also correlate changes in Pgp opioid efflux activity with changes in Pgp trafficking over a 1-72 hr time course (one-hit or rechallenge) (Aim 1B). Since production of reactive oxygen species (ROS) is a critical component of pain/inflammation, we will evaluate the effect of administration of TEMPOL (i.e., 4-hydroxy-2,2,6,6-tetramethylpiperidine-N- oxyl), a ROS scavenger, on Pgp trafficking as well as brain uptake and analgesic efficacy of opioids over a 1-72 hr time course of PIP (one-hit or rechallenge) (Aim 1C). Aim 2: To examine how PIP-induced changes in TJ protein trafficking modulate paracellular BBB permeability. In this aim, we will identify proteins associated with TJs isolated from cerebral microvessels (Aim 2A). We will also correlate changes in paracellular BBB permeability with changes in protein-protein interactions that cause changes in intracellular trafficking of occludin and claudins over a 1-72 hr time course of PIP (one-hit or rechallenge) (Aim 2B). We will then evaluate the effect of TEMPOL administration on occludin/claudin trafficking, on BBB paracellular permeability to codeine and codeine efficacy over a 1-72 hr time course of PIP (one-hit or rechallenge). (Aim 2C). Our goal in this renewal is to discover novel therapeutic targets for treating both pain and pain-induced BBB dysfunction by defining the role of protein trafficking in promoting changes in BBB structure/function that lead to altered CNS drug delivery during PIP.