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

项目总结 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)对疾病或药物作出反应的蛋白质(即claudin-5、occludin)。我们的研究表明，claudin-5和 阻塞素的表达和运输受疼痛的调节(即，TJ失调)，这是一种增加大脑的效应 摄取阿片类药物，如可待因。我们的初步数据显示，对乙酰氨基酚(APAP)可以调节 在血脑屏障表达claudin-5，并增加细胞旁通透性(即“泄漏”)。泄密事件此前曾被 显示发生在小剂量、急性可卡因和甲基苯丙胺的情况下。急性呼吸暂停和疼痛 靶向转化生长因子-β(转化生长因子-β)信号，一种控制TJ表达和血脑屏障完整性的途径。 在这项研究中，我们假设APAP本身和在疼痛的情况下，可以增加BBB “泄漏”和加强中枢阿片类药物的输送。这些研究意义重大，因为它们将揭示 阿片类药物抗伤害性感觉改变的机制和个人可能发生的不良药物事件 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 “APAP泄漏”可能导致治疗毒性。 目的1：在体内研究血脑屏障TJ蛋白表达和转运的变化 在APAP管理之后。我们将研究APAP如何改变阿片类药物的中枢神经系统效应和不良事件。 我们将研究跨膜TJ蛋白(即claudin-5，occludin)表达变化的时间进程 和转运及APAP对雄性和大鼠TJ蛋白复合体变化的量效关系 雌性SD大鼠(目标1A)。然后我们将研究中枢阿片类药物之间的时间关系 递送、阿片类药物相关的抗伤害作用、呼吸抑制和阿片类药物相关的奖励行为(目的 1B)。既然我们已经证明了转化生长因子-β(转化生长因子-β)信号调节血脑屏障的完整性，我们将 研究这一途径在claudin-5和occludin表达和贩运中的作用(目标1C)。 目的2：研究APAP对疼痛时血脑屏障完整性的影响。使用已建立的活体疼痛 模型(即L-卡拉胶诱导的急性炎症性疼痛、慢性痛性脊神经结扎)，我们将进行研究 APAP对TJ蛋白表达/运输的影响(即claudin-5、occludin)以及对中枢神经系统的影响 阿片类药物摄取(目标2A)。我们将演示单剂量和多剂量APAP对转化生长因子-β信号转导的影响 两种疼痛模型中的通路(目标2B)。我们将研究中枢阿片类药物输送的变化如何影响阿片类药物 抗伤害性、呼吸抑制和阿片类药物相关的奖励行为(目标2C)。因为我们已经展示了 APAP增加了关键阿片转运体P-糖蛋白的功能表达，我们将研究 Claudin-5/occludin调制和P-gp变化对中枢阿片递送的贡献(Aim 2D)。 我们的团队处于独特的地位，可以提供机械性的解释(即，信令、活动、 在滥用/误用处方止痛药的个人中发生不良药物事件。

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.