Role of Gut Microbiome in HIV/Opioid Induced Peripheral Neuropathy

项目摘要 长期使用阿片类药物会导致非典型疼痛(痛觉过敏)的矛盾增加。尽管它已知 尽管存在局限性，但阿片类药物引起的痛觉过敏的机制仍然是一个认识上的重大空白。 周围神经病变已成为HIV患者最常见的神经系统并发症， 在感染患者中高达69.4%，值得注意的是，艾滋病毒感染的阿片类药物滥用者似乎表现出更严重的 神经病变比HIV感染的非吸毒者更多。此外，据报告，反复使用阿片类镇痛剂可 促进艾滋病毒患者的神经病理性疼痛。对于抗逆转录病毒治疗是否会导致周围神经病变以及是否 在慢性阿片类药物使用者中，这种情况会加剧。吗啡及其衍生物的主要代谢途径 在哺乳动物中是由UDP-葡萄糖醛酸基转移酶(UGT)催化的葡萄糖醛酸化反应。吗啡是 主要代谢成两种代谢物，吗啡-3-葡萄糖醛酸(M3G)和吗啡-6-葡萄糖醛酸 (M6G)(1，2)。M-3-G是啮齿动物体内唯一产生的代谢物，没有任何止痛作用，但具有 最近的研究表明，它可以激活和调制TLR信号。此外，抗逆转录病毒药物 尤其是整合酶抑制剂，也通过UGT-葡萄糖醛酸化途径代谢。近期 研究表明，整合酶抑制剂齐多夫定的代谢产物比母体毒性更大 化合物。在初步数据中，我们显示慢性吗啡治疗会导致肠道微生物显著增加。 与合成β-葡萄糖醛酸酶的细菌群落显著减少同时发生的生物失调 葡萄糖苷酸酶活性下降。我们在初步数据中表明，细菌群落的枯竭 参与β-葡萄糖苷酸酶的合成导致a)肠道和血清中M-3-G积聚增加 以及b)减少吗啡的肠-肝循环。我们进一步证明，吗啡治疗在 HIV感染的背景导致机械性异位痛觉(Von Frey)和 热痛觉过敏试验(Hargraves)试验。促炎症细胞因子水平与吗啡诱导 TLR2基因敲除小鼠的痛觉过敏明显减轻。基于这些观察结果，我们假设 这会减少与β葡萄糖醛酸苷酶合成相关的微生物群落 暴露于大剂量吗啡可导致M-3-G代谢物蓄积和中毒 小肠中的葡萄糖醛酸化ART有助于实现特定目标1：建立 肠道中的吗啡代谢物M-3-葡萄糖苷可导致阿片类药物引起的痛敏和HIV引起的 使用阿片类药物的HIV患者的周围神经病变。具体目标2：确定TLR2信号在 ART治疗中吗啡引起的痛觉过敏和HIV相关的周围神经病。 具体目标3：利用基因工程共生菌治疗受控表达的B- 葡萄糖醛酸苷酶与TLR2/4拮抗剂联合应用将保护小肠屏障完整性并减弱 周围神经病和延长吗啡镇痛。

Project Summary Prolonged use opioids results in a paradoxical increase in atypical pain (hyperalgesia). Despite its known limitations, mechanisms underlying opioid-induced hyperalgesia still remains a significant gap in knowledge. Peripheral neuropathy has become the most common neurologic complication in HIV patients, with prevalence as high as 69.4% in infected patients, Notably, HIV-infected opioid abusers appear to exhibit more severe neuropathy than HIV-infected non-drug users. Furthermore, repeated use of opioid analgesics are reported to promote neuropathic pain in HIV patients. Very little is known if ART contributes to peripheral neuropathy and if it is exacerbated in chronic opioid users. The main metabolic pathway for morphine and morphine derivatives in mammals is glucuronidation catalyzed by UDP-glucuronosyltransferase (UGT) enzymes. Morphine is metabolized predominantly to two metabolites, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) (1,2). M-3-G is the only metabolite produced in rodents and does not have any analgesic effects but have been shown in recent studies to activate and modulate TLR signaling. Furthermore, antiretroviral drugs particularly, intergrase inhibitors, are also metabolized through the UGT- glucuronidation pathway. Recent studies show that the metabolites of the intergrase inhibitor zidovudine to be more toxic than the parent compound. In preliminary data we show that chronic morphine treatment results in significant gut microbial dysbiosis with significant decrease in bacterial communities that synthesize β-glucuronidase with a concurrent decrease in glucuronidase activity. We show in preliminary data that depletion in the bacterial communities involved in the synthesis of β -glucuronidase results in a) increased accumulation M-3-G in the gut and serum and b) reduced enterohepatic recycling of morphine. We further demonstrate that morphine treatment in the context of HIV infection results in significant hyperalgesia in the both the Mechanical allodynia (Von Frey) and Thermal hyperalgesia test (Hargraves) tests. Proinflammatory cytokine levels and morphine induced hyperalgesia are significantly attenuated in TLR2 knock out mice. Based on these observations we hypothesize that decreased microbial communities associated with β glucuronidase synthesis following prolonged exposure to high dose morphine results in accumulation of M-3-G morphine metabolite and toxic glucuronidated ART in the small intestine contributing to Specific Aim 1: Establish that accumulation of the morphine metabolite M-3-glucoronide in the gut results in opioid induced hyperalgesia and HIV induced peripheral neuropathy in opiod using HIV patients. Specific Aim 2: Determine the role of TLR2 signaling in morphine induced hyperalgesia and HIV associated peripheral neuropathy in the context of ART treatment. Specific Aim 3: Treatment with genetically engineered commensal bacteria with controlled expression of B- glucuronidase in combination with TLR2/4 antagonist will preserve small intestinal barrier integrity and attenuate peripheral neuropathy and prolong morphine analgesia.