Use of precision deuteration to determine the contribution of norbuprenorphine to buprenorphine-associated neonatal abstinence syndrome

项目摘要/摘要 丁丙诺啡(BUP)是治疗阿片类药物使用障碍(OUD)的有效药物； 在怀孕期间，子代的身体依赖率很高，并导致戒断 称为新生儿禁欲综合征(NAS)的综合症。可以说，BUP是目前最好的治疗方法 因为与其他治疗或不治疗相比，它可以改善母婴结局，但 与BUP相关的NAS的高发生率表明需要改进治疗。了解 促进BUP相关NAS的机制可以促进改进治疗的发展。 有证据表明，胎儿接触BUP的一种主要活性代谢物，称为去丁丙诺啡 (NorBUP)，可能会促进BUP关联的NAS。此外，NorBUP似乎并没有对 BUP的疗效，说明NorBUP对BUP的治疗不是至关重要的。因此，减少或 消除NorBUP的形成是改善BUP治疗的潜在策略。然而，在多大程度上 NorBUP对NAS的贡献当前未定义，因为没有方法区分 BUP和NorBUP对BUP用药的影响。这项提议寻求开发一种新的工具， 氢化丁丙诺啡(BUP-D2)，这将区分NorBUP和BUP在 BUP关联的NAS。初步数据表明，相对于BUP，BUP-D2抵抗NorBUP的代谢 但完全保留了BUP的阿片活性。这些特性将阐明胎儿是否接触NorBUP 极大地促进了BUP相关的NAS。这项研究中提出的实验将确定 慢性产前应用BUP-D2后胎儿对NorBUP的暴露是否减少 相对于BUP，将表征阿片受体亲和力和BUP-D2的活性。我们假设 与BUP相比，BUP-D2在怀孕期间服用时将减少胎儿对NorBUP的暴露 并将保留BUP的阿片类活性。目标1将比较胎儿大脑中NorBUP的浓度 在妊娠晚期使用BUP-D2与BUP进行慢性产前治疗后收获。Aim 1也将 测量母体药物NorBUP和其他主要代谢物在母体血浆中的浓度 大脑、胎儿血浆和胎儿大脑，以确定这些是否发生代偿性药代动力学变化 BUP-D2给药后的化合物。目标2将表征BUP-D2与 BUP使用转染人Mu、Delta或kappa阿片受体的CHO细胞进行体外检测。如果BUP- D2减少胎儿大脑对NorBUP的暴露并保留BUP的活性，它将在未来的研究中用于 确定产前BUP治疗期间胎儿暴露于NorBUP的影响。如果NorBUP确认为 对胎儿产生不良影响，将研究BUP-D2作为治疗OUD的潜在改进方法 怀孕了。

PROJECT SUMMARY/ABSTRACT Buprenorphine (BUP) is an effective treatment for opioid use disorder (OUD); however, treatment with BUP during pregnancy is associated with a high rate of physical dependence in offspring and leads to a withdrawal syndrome known as neonatal abstinence syndrome (NAS). Arguably, BUP is currently the best treatment for OUD during pregnancy because it improves maternal—child outcomes relative to other or no treatments, but the high rate of NAS associated with BUP indicates that improved treatments are needed. Understanding the mechanisms that promote BUP-associated NAS can facilitate the development of improved treatments. Evidence suggests that fetal exposure to a major active metabolite of BUP, called norbuprenorphine (NorBUP), may promote BUP-associated NAS. Moreover, NorBUP does not appear to contribute to the therapeutic effects of BUP, indicating that NorBUP is not vital for BUP treatment. Therefore, reducing or eliminating NorBUP formation is a potential strategy to improve BUP treatment. However, the degree to which NorBUP contributes to NAS is currently undefined because there have been no means to distinguish the effects of BUP and NorBUP following BUP administration. This proposal seeks to develop a new tool, deuterated buprenorphine (BUP-D2), that will distinguish the contributions of NorBUP and BUP in BUP-associated NAS. Preliminary data suggests that BUP-D2 resists metabolism to NorBUP relative to BUP but fully retains the opioid activity of BUP. These properties will elucidate whether fetal exposure to NorBUP substantially contributes to BUP-associated NAS. The experiments proposed in this study will determine whether fetal exposure to NorBUP is reduced following chronic prenatal treatment with BUP-D2 relative to BUP, and will characterize opioid receptor affinity and activity of BUP-D2. We hypothesize that relative to BUP, BUP-D2 will decrease fetal exposure to NorBUP when administered during pregnancy and will retain the opioid activity of BUP. Aim 1 will compare concentrations of NorBUP in fetal brains harvested during late gestation following chronic prenatal treatment with BUP-D2 versus BUP. Aim 1 also will measure concentrations of parent drugs, NorBUP, and other major metabolites in maternal plasma, maternal brain, fetal plasma, and fetal brain to determine if compensatory pharmacokinetics changes occur with these compounds following BUP-D2 administration. Aim 2 will characterize the affinity and activity of BUP-D2 versus BUP with in vitro assays using CHO cells transfected with human mu, delta, or kappa opioid receptors. If BUP- D2 reduces fetal brain exposure to NorBUP and retains the activity of BUP, it will be used in future studies to determine the impact of fetal exposure to NorBUP during prenatal BUP treatment. If NorBUP is confirmed to exert adverse effects on the fetus, BUP-D2 will be investigated as a potential improved therapy for OUD during pregnancy.