Modulation of endogenous opioid signaling by inhibitors of puromycin sensitive aminopeptidase.
Modulation of endogenous opioid signaling by inhibitors of puromycin sensitive aminopeptidase.
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嘌呤霉素敏感氨肽酶抑制剂调节内源性阿片类信号传导。
DOI：
10.1101/2024.04.02.587756
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发表时间：
2024
期刊：
影响因子：
--
通讯作者：
More,SwatiS
中科院分区：
文献类型：
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作者：
Singh,Rohit;Jiang,Rongrong;Williams,Jessica;Dobariya,Prakashkumar;Hanak,Filip;Xie,Jiashu;Rothwell,PatrickE;Vince,Robert;More,SwatiS
内源性阿片系统通过局部释放神经肽和调节它们对阿片受体的作用来调节疼痛。然而，阿片肽的作用是短暂的，因为它们被脑啡肽降解酶迅速水解。反过来，一种治疗疼痛的创新方法是通过防止脑啡肽被神经脑啡肽酶（如嘌呤霉素敏感氨基肽酶（PSA））失活来增加局部浓度并延长其稳定性。我们之前的结构-活性关系研究表明，嘌呤霉素的s -二苯基甲基半胱氨酸衍生物（20）是一种纳米摩尔的PSA抑制剂。然而，这类化学物质对肾毒性嘌呤霉素氨基核苷（PAN）的代谢不良。为了防止这种毒性，我们设计并合成了5 ' -氯取代衍生物。该化合物保留了相应的5′-羟基类似物的PSA抑制效力，并提高了对PSA的选择性。在抗痛觉试验中，用先导化合物进行体内治疗可显著降低疼痛反应，无论是单独治疗还是与met -脑啡肽联合治疗。镇痛作用被阿片拮抗剂纳洛酮逆转，提示阿片受体参与其中。此外，脑切片中化合物19对PSA的抑制导致内源性脑啡肽水平的局部增加，证实了我们的理论基础。化合物19的药代动力学评估显示出良好的血浆稳定性，并确定半胱氨酸硫是代谢倾向的主要位点。我们通过分子建模获得了抑制剂- psa相互作用的额外见解，这强调了大体积芳香氨基酸在嘌呤霉素支架中的重要性。这项研究的结果有力地支持了我们开发PSA抑制剂用于有效疼痛管理的基本原理。
The endogenous opioid system regulates pain through local release of neuropeptides and modulation of their action on opioid receptors. However, the effect of opioid peptides, the enkephalins, is short-lived due to their rapid hydrolysis by enkephalin-degrading enzymes. In turn, an innovative approach to the management of pain would be to increase the local concentration and prolong the stability of enkephalins by preventing their inactivation by neural enkephalinases such as puromycin-sensitive aminopeptidase (PSA). Our previous structure-activity relationship studies offered the S-diphenylmethyl cysteinyl derivative of puromycin (20) as a nanomolar inhibitor of PSA. This chemical class, however, suffered from undesirable metabolism to nephrotoxic puromycin aminonucleoside (PAN). To prevent such toxicity, we designed and synthesized 5′-chloro substituted derivatives. The compounds retained the PSA inhibitory potency of the corresponding 5′-hydroxy analogs and had improved selectivity toward PSA. In vivo treatment with the lead compound19caused significantly reduced pain response in antinociception assays, alone and in combination with Met-enkephalin. The analgesic effect was reversed by the opioid antagonist naloxone, suggesting the involvement of opioid receptors. Further, PSA inhibition by compound19in brain slices caused local increase in endogenous enkephalin levels, corroborating our rationale. Pharmacokinetic assessment of compound19showed desirable plasma stability and identified the cysteinyl sulfur as the principal site of metabolic liability. We gained additional insight into inhibitor-PSA interactions by molecular modeling, which underscored the importance of bulky aromatic amino acid in puromycin scaffold. The results of this study strongly support our rationale for the development of PSA inhibitors for effective pain management.