University of Miami, Miller School of Medicine, Miami Project, 1095 NW 14(th) terrace, Miami, FL 33136, USA.
University of Miami, Miller School of Medicine, Miami Project, 1095 NW 14(th) terrace, Miami, FL 33136, USA.
Pharmacol Biochem Behav. 2021 Jun;205:173182. doi: 10.1016/j.pbb.2021.173182. Epub 2021 Mar 25.
Cannabinoid (CB) receptor agonists show robust antinociceptive effects in various pain models. However, most of the clinically potent CB1 receptor-active drugs derived from cannabis are considered concerning due to psychotomimetic side effects. Selective CB receptor ligands that do not induce CNS side effects are of clinical interest. The venoms of marine snail Conus are a natural source of various potent analgesic peptides, some of which are already FDA approved. In this study we evaluated the ability of several Conus venom extracts to interact with CB1 receptor. HEK293 cells expressing CB1 receptors were treated with venom extracts and CB1 receptor internalization was analyzed by immunofluorescence. Results showed C. textile (C. Tex) and C. miles (C. Mil) samples as the most potent. These were serially subfractionated by HPLC for subsequent analysis by internalization assays and for analgesic potency evaluated in the formalin test and after peripheral nerve injury. Intrathecal injection of C. Tex and C. Mil subfractions reduced flinching/licking behavior during the second phase of formalin test and attenuated thermal and mechanical allodynia in nerve injury model. Treatment with proteolytic enzymes reduced CB1 internalization of subfractions, indicating the peptidergic nature of CB1 active component. Further HPLC purification revealed two potent antinociceptive subfractions within C. Tex with CB1 and possible CB2 activity, with mild to no side effects in the CB tetrad assessment. CB conopeptides can be isolated from these active Conus venom-derived samples and further developed as novel analgesic agents for the treatment of chronic pain using cell based or gene therapy approaches.
大麻素 (CB) 受体激动剂在各种疼痛模型中显示出强大的镇痛作用。然而，大多数源自大麻的具有临床效力的 CB1 受体活性药物由于具有致幻副作用而被认为令人担忧。不引起中枢神经系统副作用的选择性 CB 受体配体具有临床意义。海洋蜗牛 Conus 的毒液是各种有效止痛肽的天然来源，其中一些已获得 FDA 批准。在这项研究中，我们评估了几种 Conus 毒液提取物与 CB1 受体相互作用的能力。用毒液提取物处理表达 CB1 受体的 HEK293 细胞，并通过免疫荧光分析 CB1 受体内化。结果表明 C. textile (C. Tex) 和 C. miles (C. Mil) 样品是最有效的。这些样品通过 HPLC 进行连续亚分级，然后通过内化测定和福尔马林试验以及周围神经损伤后评估镇痛效力进行后续分析。鞘内注射 C. Tex 和 C. Mil 亚级分可减少福尔马林试验第二阶段的畏缩/舔舐行为，并减轻神经损伤模型中的热和机械性痛觉过敏。用蛋白水解酶处理可降低亚级分的 CB1 内化，表明 CB1 活性成分具有肽性质。进一步的 HPLC 纯化显示 C. Tex 中有两个具有 CB1 和可能的 CB2 活性的强效镇痛亚级分，在 CB 四联体评估中具有轻度至无副作用。可以从这些具有活性的 Conus 毒液衍生样品中分离出 CB 短肽，并通过基于细胞或基因治疗的方法进一步开发为治疗慢性疼痛的新型镇痛剂。
