Development of a highly-specific ^(18)F-labeled irreversible positron emission tomography tracer for monoacylglycerol lipase mapping

As a serine hydrolase,monoacylglycerol lipase(MAGL) is principally responsible for the metabolism of 2-arachidonoylglycerol(2-AG) in the central nervous system(CNS),leading to the formation of arachidonic acid(AA).Dysfunction of MAGL has been associated with multiple CNS disorders and symptoms,including neuroinflammation,cognitive impairment,epileptogenesis,nociception and neurodegenerative diseases.Inhibition of MAGL provides a promising therapeutic direction for the treatment of these conditions,and a MAGL positron emission tomography(PET) probe would greatly facilitate preclinical and clinical development of MAGL inhibitors.Herein,we design and synthesize a small library of fluoropyridyl-containing MAGL inhibitor candidates.Pharmacological evaluation of these candidates by activity-based protein profiling identified 14 as a lead compound,which was then radiolabeled with fluorine-18 via a facile SNAr reaction to form 2-[^(18)F]fluoropyridine scaffold.Good blood-brain barrier permeability and high in vivo specific binding was demonstrated for radioligand [^(18)F]14(also named as [^(18)F]MAGL-1902).This work may serve as a roadmap for clinical translation and further design of potent 18F-labeled MAGL PET tracers.

基于内源性大麻素探讨皂术抗纤方治疗肝纤维化大鼠的作用机制

目的:基于内源性大麻素研究皂术抗纤方对肝纤维化大鼠的药理效应及其作用机制。方法:按照随机数字表法将40只Wistar雄性大鼠随机分为正常组、模型组、皂术抗纤方组和安络化纤丸组,每组10只。模型组、皂术抗纤方组和安络化纤丸组给予四氯化碳(CCl4)腹腔注射8周,复制肝纤维化模型。第5~8周,皂术抗纤方组、安络化纤丸组分别给予皂术抗纤方(16.1g/kg)、安络化纤丸(30g/kg)治疗。检测各组大鼠血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)水平,肝组织羟脯氨酸(Hyp)、N-花生四烯酸氨基乙醇(AEA)、2-花生四烯酸甘油(2-AG)及内源性大麻素水解酶脂肪酰胺水解酶(FAAH)、单酰基甘油酯酶(MGL)mRNA表达量变化。结果:与正常组比较,模型组大鼠肝组织出现明显肝纤维化,血清ALT、AST水平及肝组织Hyp、AEA、2-AG含量显著升高(P<0.01),FAAH、MGL mRNA表达显著降低(P<0.01)。与模型组比较,皂术抗纤方组、安络化纤丸组血清ALT、AST水平及肝组织Hyp含量均显著降低(P<0.01),皂术抗纤方组肝组织大麻素AEA、2-AG含量显著降低(P<0.01),FAAH、MGL mRNA表达显著升高(P<0.01)。结论:皂术抗纤方治疗肝纤维化效果显著,其作用机制与调节内源性大麻素有关。