Increased CNS Opioid Exposure by an Acetaminophen-Induced Blood-Brain Barrier Mechanism

项目摘要 在过去的几年里，我们研究了临界血脑屏障（BBB）紧密连接的变化， (TJ)蛋白质（即，claudin-5，occludin）。我们的工作表明，claudin-5和 闭合蛋白的表达和运输受到疼痛的调节（即，TJ失调），一种增加大脑 服用阿片类药物，如可待因。我们的初步数据表明，对乙酰氨基酚（APAP）可以调节 封闭蛋白-5在BBB的表达并增加细胞旁通透性（即，“泄漏”）。此前， 显示在低剂量、急性可卡因给药以及甲基苯丙胺时发生。APAP和疼痛 靶向转化生长因子- β（TGF-β）信号传导，这是一种控制TJ表达和BBB完整性的途径。 在这项研究中，我们假设APAP本身和疼痛情况下可以增加BBB “泄漏”和增强CNS阿片样物质递送。这些研究非常重要，因为它们将揭示 阿片类药物抗伤害感受改变的机制和可能发生在个体中的药物不良事件 滥用或误用阿片类药物或APAP。此外，APAP与其他中枢作用药物一起服用 其中“APAP泄漏”可导致治疗毒性。 目的1：研究在体条件下，血脑屏障中TJ蛋白表达和运输的变化 APAP管理后。我们将研究APAP如何改变阿片类药物的CNS效应和不良事件。 我们将研究跨膜TJ蛋白变化的时间过程（即，claudin-5，occludin）表达 APAP对男性和女性TJ蛋白复合物的影响及其剂量-反应关系 雌性Sprague-Dawley大鼠（Aim 1A）。然后我们将研究中枢神经系统阿片类药物之间的时间关系 传递、阿片相关的抗伤害感受、呼吸抑制和阿片相关的奖赏行为（目的 1B）。由于我们已经证明转化生长因子- β（TGF-β）信号转导调节血脑屏障的完整性，我们将 研究该通路对claudin-5和occludin表达和运输的作用（Aim 1C）。 目的2：研究疼痛时APAP对BBB完整性的影响。使用已建立的体内疼痛 模型（即，l-角叉菜胶诱导的急性炎性疼痛、慢性疼痛脊神经结扎），我们将研究 APAP影响TJ蛋白表达/运输的时间过程（即，claudin-5，occludin）以及CNS 阿片样物质摄取（Aim 2A）。我们将证明APAP单次与多次给药对TGF-β信号传导的影响 两种疼痛模型中的通路（Aim 2B）。我们将研究中枢阿片传递的变化如何影响阿片 抗伤害感受、呼吸抑制和阿片类药物相关的奖赏行为（Aim 2C）。因为我们已经证明 APAP增加了关键阿片转运蛋白P-糖蛋白的功能表达，我们将研究 claudin-5/occludin调节和P-gp变化对CNS阿片样物质递送的贡献（Aim 2D）。 我们的小组处于独特的地位，可以提供一个机械的解释（即，信号，活动， 贩运），用于滥用/误用处方止痛药的个人的药物不良事件。

PROJECT SUMMARY Over the past several years, we have studied changes in critical blood-brain barrier (BBB) tight junction (TJ) proteins (i.e., claudin-5, occludin) in response to diseases or drugs. Our work has shown that claudin-5 and occludin expression and trafficking is modulated by pain (i.e., TJ dysregulation), an effect that increases brain uptake of opioids such as codeine. Our preliminary data show that acetaminophen (APAP) can modulate expression of claudin-5 at the BBB and increase paracellular permeability (i.e., “leak”). Leak has previously been shown to occur with low dose, acute cocaine administration as well as methamphetamine. Both APAP and pain target transforming growth factor- β (TGF-β) signaling, a pathway that controls TJ expression and BBB integrity. In this grant, we hypothesize that APAP, by itself and in the setting of pain, can increase BBB “leak” and enhance CNS opioid delivery. These studies are highly significant because they will uncover mechanisms of altered opioid antinociception and adverse drug events that can occur in individuals who abuse or misuse opioids or APAP. Additionally, APAP is taken with other centrally acting drugs where “APAP leak” can lead to therapeutic toxicity. Aim 1: To investigate, in vivo, changes in TJ protein expression and trafficking at the BBB following APAP administration. We will study how APAP alters CNS effects and adverse events of opioids. We will investigate the time course of changes in transmembrane TJ protein (i.e., claudin-5, occludin) expression and trafficking and the dose-response relationship of APAP on changes in TJ protein complexes in male and female Sprague-Dawley rats (Aim 1A). We will then study the temporal relationship between CNS opioid delivery, opioid-associated antinociception, respiratory depression, and opioid-associated reward behavior (Aim 1B). Since we have shown that transforming growth factor- β (TGF-β) signaling regulates BBB integrity, we will study the role of this pathway on claudin-5 and occludin expression and trafficking (Aim 1C). Aim 2: To examine involvement of APAP on BBB integrity in pain. Using established in vivo pain models (i.e., l-carrageenan-induced acute inflammatory pain, chronic pain spinal nerve ligation), we will study the time course of APAP effects on TJ protein expression/trafficking (i.e., claudin-5, occludin) as well as on CNS opioid uptake (Aim 2A). We will demonstrate effects of single versus multiple doses of APAP on TGF-β signaling pathways in both pain models (Aim 2B). We will study how changes in CNS opioid delivery affect opioid antinociception, respiratory depression, and opioid-associated reward behavior (Aim 2C). Since we have shown that APAP increases functional expression of the critical opioid transporter P-glycoprotein, we will examine the contribution of claudin-5/occludin modulation and P-gp changes to CNS opioid delivery (Aim 2D). Our group is uniquely positioned to provide a mechanistic explanation (i.e., signaling, activity, trafficking) for adverse drug events in individuals who abuse/misuse prescription pain drugs.