Ghrelin Deacylase as a Treatment for Opioid Polysubstance Abuse

生长素释放肽脱酰酶治疗阿片类多物质滥用

• 批准号: 10510245
• 负责人: CHANG-GUO ZHAN
• 金额: $ 170.09万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10510245
• 关键词: Acute; Adverse effects; Affect; Aftercare; Alcohols; Amino Acids; Amphetamines; Animals; Attenuated; Behavior; Binding; Biological Assay; Blood Circulation; Brain; Butyrylcholinesterase; Chimeric Proteins; Chronic; Cocaine; DR1 gene; Data; Dependence; Development; Disease; Dopamine; Dopamine Receptor; Down-Regulation; Drug Exposure; Drug abuse; Enzymes; Esthesia; Euphoria; Feeling; Fentanyl; G-Protein-Coupled Receptors; Gastric Acid; Heroin; High Prevalence; Human; Hydrolase; Hyperactivity; Hypesthesia; In Vitro; Ingestion; Investigation; Lead; Ligands; Literature; Methamphetamine; Morphine; National Institute of Drug Abuse; Neurons; Nicotine; Octanoic Acids; Opioid; Pathway interactions; Peptides; Perception; Pharmaceutical Preparations; Play; Presynaptic Terminals; Process; Production; Property; Proteins; Rattus; Receptor Signaling; Recombinant Proteins; Relapse; Reporting; Research; Rewards; Rodent; Rodent Model; Role; Self Administration; Side; Signal Transduction; Site-Directed Mutagenesis; Somatotropin; Stimulant; Stimulus; Stomach; Structure; Substance Use Disorder; Substance of Abuse; Synapses; System; Testing; Therapeutic; Travel; Withdrawal; Work; animal data; antagonist; base; behavioral study; conditioned place preference; deacylation; design; dopamine system; dopamine transporter; dopaminergic neuron; drug reward; effective therapy; enzyme activity; ghrelin; growth hormone secretagogue receptor; improved; in vivo; in vivo evaluation; methamphetamine effect; methamphetamine use; mutant; novel; novel therapeutic intervention; novel therapeutics; opioid use disorder; opioid user; pleasure; polysubstance abuse; polysubstance use; protein expression; protein purification; rational design; receptor; receptor expression; response; substance use; substance use treatment; success; therapeutic candidate; treatment strategy

With currently available medications for opioid use disorder (OUD), the relapse rate is very high. Further, co- use of an opioid and a stimulant, such as methamphetamine (METH), undermines success in treatment for OUD. It is highly desired to develop novel therapeutic options for treatment of OUDs including polysubstance use disorders (PSUDs). Recently reported studies have revealed an interesting role of ghrelin in drug abuse and reward-relevant behaviors. Ghrelin is known as a “growth-hormone-releasing acylated peptide from stomach”, a 28 amino-acid peptide with the third residue (Ser3) acylated by n-octanoic acid. Ghrelin is produced in the stomach, travels to the brain through blood circulation, and acts on ghrelin (or growth hormone secretagogue) receptor (GHSR) to stimulate the mesolimbic dopamine reward pathway and increase rewarding behaviors in rodents. GHSR antagonism has been shown to attenuate rewarding effects induced by various substances including METH, amphetamine, fentanyl, morphine, heroin, cocaine, nicotine, and alcohol. For example, administration of a selective GHSR antagonist significantly reduced the fentanyl‐seeking/relapse‐like behavior in rats. On the other hand, GHSR has diverse regulatory roles associated with its constitutive activity (the activity in the absence of ghrelin ligand) and, hence, GHSR antagonism could also result in unwanted adverse effects. Thus, alternative strategies targeting ghrelin itself could be more interesting. However, whether targeting ghrelin itself would be effective to attenuate the drug rewarding effects remains controversial in literature as ghrelin levels before and after treatment were not measured in previous animal studies targeting ghrelin itself. It is unclear whether any of the previously used approaches was able to decrease the ghrelin level significantly enough to attenuate the substance reward. We propose to use our recently identified ghrelin deacylase (a mutant of human butyrylcholinesterase or BChE) as a safe and effective ghrelin modulator to attenuate substance rewarding effects. Such a ghrelin modulator is expected to be as effective as a GHSR antagonist in treatment of substance use disorders (SUDs) including PSUDs, but without interacting with any brain receptors/transporters. Specifically, in this investigation, we will first evaluate the BChE mutant for its in vivo potency in modulating ghrelin and attenuating the rewarding and reinforcing effects of representative opioids (fentanyl and heroin) and their combinations with METH in various rodent models. Then, we will design and discover a new BChE mutant as a more potent ghrelin deacylase with further improved catalytic activity for ghrelin diacylation, develop its long-acting fusion protein form, and examine the long-term in vivo effects of the long-acting ghrelin deacylase. Accomplishment of this investigation will determine whether ghrelin itself is a truly effective target and whether a potent ghrelin deacylase as a ghrelin modulator is truly effective for treatment of PSUDs. If the answers are all positive, the most effective long-acting ghrelin deacylase (recombinant protein) to be tested and developed may also serve as a promising therapeutic candidate for treatment of PSUDs.

使用目前可用的阿片类药物使用障碍（OUD），复发率非常高。此外，CO- 阿片类药物和兴奋剂如甲基苯丙胺（METH）的使用破坏了OUD治疗的成功。 高度期望开发用于治疗OUD的新的治疗选择，包括多物质使用 疾病（PSUD）。最近报道的研究揭示了胃饥饿素在药物滥用中的有趣作用， 奖励相关的行为。Ghrelin被称为“来自胃的生长激素释放酰化肽”， 第三个残基（Ser 3）被正辛酸酰化的28个氨基酸肽。生长激素释放肽产生于 胃，通过血液循环到达大脑，并作用于ghrelin（或生长激素促分泌素） 受体（GHSR）刺激中脑边缘多巴胺奖励途径，增加奖励行为， 啮齿动物GHSR拮抗作用已被证明可减弱各种物质诱导的奖赏效应 包括甲基苯丙胺芬太尼吗啡海洛因可卡因尼古丁和酒精比如说， 给予选择性GHSR拮抗剂显著降低了芬太尼寻求/复发样行为 对大鼠另一方面，GHSR具有与其组成性活性（活性）相关的多种调节作用。 在缺乏生长素释放肽配体的情况下），因此，GHSR拮抗作用也可能导致不希望的副作用。 因此，针对ghrelin本身的替代策略可能更有趣。然而，是否针对生长激素释放肽 其本身是否能有效减弱药物奖赏效应在文献中仍存在争议， 在以前针对生长素释放肽本身的动物研究中没有测量治疗前后的水平。是 不清楚以前使用的任何方法是否能够显著降低ghrelin水平 足以削弱物质奖励。我们建议使用我们最近发现的ghrelin脱酰酶（突变体 人丁酰胆碱酯酶或BChE）作为一种安全有效的胃饥饿素调节剂 奖励效应预期这种生长激素释放肽调节剂在治疗胃肠道疾病中与GHSR拮抗剂一样有效。 物质使用障碍（SUD），包括PSUD，但不与任何脑受体/转运蛋白相互作用。 具体而言，在这项研究中，我们将首先评估BChE突变体在调节细胞内代谢方面的体内效力， 生长激素释放肽和减弱代表性阿片类药物（芬太尼和海洛因）的奖励和强化作用， 在各种啮齿动物模型中与METH的组合。然后，我们将设计并发现一个新的BChE突变体， 作为一种更有效的生长素释放肽脱酰酶，具有进一步改善的生长素释放肽二酰化催化活性，开发其 长效融合蛋白形式，并检查长效生长素释放肽脱酰基酶的长期体内作用。 这项研究的完成将决定ghrelin本身是否是一个真正有效的目标， 作为生长素释放肽调节剂的有效的生长素释放肽脱酰基酶对于治疗PSUD确实有效。如果答案都是 阳性，待测试和开发的最有效的长效生长激素释放肽脱酰基酶（重组蛋白）可 也作为治疗PSUD的有前景的治疗候选物。