State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing 100850, China.
State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing 100850, China; School of Pharmacy, Yantai University, Yantai 264005, China.
Life Sci. 2020 Jul 1;252:117676. doi: 10.1016/j.lfs.2020.117676. Epub 2020 Apr 15.
Many μ-opioid receptor (MOR)-associated proteins can regulate the MOR signaling pathway. Using a bacterial two-hybrid screen, we found that the C-terminal of the MOR associated with heat shock protein 90 isoform β (Hsp90β). Here, we explored the effect of Hsp90β on MOR signaling transduction and function.
The interaction of Hsp90β with MOR was detected by co-immunoprecipitation and immunofluorescence. The effects of Hsp90β on MOR signaling induced by opioids were studied in vitro and in vivo. The effects of the Hsp90β inhibitor 17-N-allylamino-17-demethoxygeldanamycin (17-AAG) on morphine tolerance and dependence were studied via a hot plate test and CPP test.
Hsp90β, instead of Hsp90α, interacted with the MOR in HEK293 cells and SH-SY5Y cells, and the interaction was augmented after morphine pretreatment. The interaction of Hsp90β and MOR increased the inhibition of cAMP and decreased PKA activity under opioid treatment. The functional Hsp90β-MOR complex also promoted the phosphorylation and internalization of the MOR induced by DAMGO in MOR-CHO cells. 17-AAG blocked Hsp90β-MOR interactions and decreased the effect of Hsp90β on the MOR signal transduction. In C57BL/6 mice, 17-AAG decreased morphine-induced acute anti-nociception in the hot plate test, with an increase in phosphorylated PKA and phosphorylated JNK and a decrease in phosphorylated CREB and phosphorylated ERK in murine brains. Chronic morphine treatment induced tolerance, and dependence was inhibited by 17-AAG co-administration.
Hsp90β is a positive co-regulator of the MOR via the activation of a G-protein-dependent and β-arrestin-dependent pathway. Hsp90β has the potential to improve the pharmacologic profile of existing opiates. It is conceivable that in future clinical treatments, the Hsp90β inhibitor, 17-AAG, could decrease the tolerance and dependence in cancer patients induced by opioids.
许多μ-阿片受体（MOR）相关蛋白可以调节 MOR 信号通路。我们使用细菌双杂交筛选，发现 MOR 与热休克蛋白 90 同工型β（Hsp90β）的 C 端相互作用。在这里，我们探讨了 Hsp90β对 MOR 信号转导和功能的影响。
通过共免疫沉淀和免疫荧光检测 Hsp90β 与 MOR 的相互作用。在体外和体内研究 Hsp90β 对阿片类药物诱导的 MOR 信号的影响。通过热板试验和 CPP 试验研究 Hsp90β 抑制剂 17-N-烯丙基-17-去甲氧基格尔德霉素（17-AAG）对吗啡耐受和依赖的影响。
Hsp90β 而不是 Hsp90α，与 HEK293 细胞和 SH-SY5Y 细胞中的 MOR 相互作用，并且在吗啡预处理后增强。在阿片类药物治疗下，Hsp90β 和 MOR 的相互作用增加了 cAMP 的抑制和 PKA 活性的降低。功能性 Hsp90β-MOR 复合物还促进了 DAMGO 诱导的 MOR-CHO 细胞中 MOR 的磷酸化和内化。17-AAG 阻断了 Hsp90β-MOR 相互作用，降低了 Hsp90β 对 MOR 信号转导的影响。在 C57BL/6 小鼠中，17-AAG 降低了吗啡在热板试验中的急性镇痛作用，同时增加了磷酸化 PKA 和磷酸化 JNK，减少了磷酸化 CREB 和磷酸化 ERK 在小鼠大脑中的表达。慢性吗啡处理诱导耐受，17-AAG 共给药抑制依赖。
Hsp90β 通过激活 G 蛋白依赖性和β-arrestin 依赖性途径，是 MOR 的正协同调节剂。Hsp90β 有可能改善现有阿片类药物的药理特性。可以想象，在未来的临床治疗中，Hsp90β 抑制剂 17-AAG 可以降低癌症患者因阿片类药物引起的耐受和依赖。
