In Vivo Characterization of the Ultrapotent Monoacylglycerol Lipase Inhibitor  (1H-1,2,4-triazol-1-yl)methanone (JJKK-048)

Abstract

In Vivo Characterization of the Ultrapotent Monoacylglycerol Lipase Inhibitor {4- [bis-(benzo[d] [1,3]dioxol-5-yl)methyl]-piperidin-1-yl}(1H-1,2,4-triazol-1-yl)methanone Niina Aaltonen, Ewa Kedzierska, Jolanta Orzelska-Górka, Marko Lehtonen, Dina Navia-Paldanius, Hermina Jakupovic, Juha R. Savinainen, Tapio Nevalainen, Jarmo T. Laitinen, Teija Parkkari, and Mikko Gynther ABSTRACT Monoacylglycerol lipase (MAGL) is a serine hydrolase that acts as a principal degradative enzyme for the endocannabinoid 2-arachidonoylglycerol (2-AG). In addition to terminating the signaling function of 2-AG, MAGL liberates arachidonic acid to be used as a primary source for neuroinflammatory prostaglandin synthesis in the brain. MAGL activity also contributes to cancer pathogenicity by producing precursors for tumor-promoting bioactive lipids. Pharmacological inhibitors of MAGL provide valuable tools for characterization of MAGL and 2-AG signaling pathways. They also hold great therapeutic potential to treat several pathophysiological conditions, such as pain, neurodegenerative disorders, and cancer. We have previously reported piperidine triazole urea, {4-[bis- , to be an ultrapotent and highly selective inhibitor of MAGL in vitro. Here, we characterize in vivo effects of JJKK-048. Acute in vivo administration of JJKK-048 induced a massive increase in mouse brain 2-AG levels without affecting brain anandamide levels. JJKK-048 appeared to be extremely potent in vivo. Activity-based protein profiling revealed that JJKK-048 maintains good selectivity toward MAGL over other serine hydrolases. Our results are also the first to show that JJKK-048 promoted significant analgesia in a writhing test with a low dose that did not cause cannabimimetic side effects. At a high dose, JJKK-048 induced analgesia both in the writhing test and in the tail-immersion test, as well as hypomotility and hyperthermia, but not catalepsy. IntroductionEndocannabinoids are lipid-structured signaling molecules that act as natural ligands for cannabinoid CB 1 and CB 2 receptors, which are also the targets of the psychoactive component of Cannabis sativa. The two most intensively studied endocannabinoids are 2-arachidonoylglycerol (2-AG) and anandamide (AEA) (Devane et al., 1992;Mechoulam et al., 1995;Sugiura et al., 1995). Generally, endocannabinoids are synthesized on demand from plasma membrane phospholipid precursors, and after exerting their effect by activating specific receptors, they are rapidly degraded by enzymatic activity. The principal brain endocannabinoid is 2-AG, which regulates central nervous system development and synaptic plasticity (Bisogno et al., 1999;Berghuis et al., 2007;Hashimotodani et al., 2007). Endocannabinoids also regulate cognition, emotional functions, and food intake, and are involved in several pathophysiological processes, including pain and neurodegenerative diseases (Pacher et al., 2006;Di Marzo and Petrosino, 2007;Sugiura, 2009). However, for therapeutic purposes, direct activation of cannabinoid receptors has proved to be c...

Synthesis, docking studies, and pharmacological evaluation of 5HT2C ligands containing the N′‐cyanoisonicotinamidine or N′‐cyanopicolinamidine nucleus

“…Animals were put back in their home cage after each measurement of catalepsy. Mice that remained motionless with their paws on the bar for 10 s (with the exception of respiratory movements) were scored as cataleptic …”

Emerging Role of (Endo)Cannabinoids in Migraine

“…Both within CNS and peripherally, eCBs act as retrograde messengers or synaptic modulators for their respective target cells ( Gabral et al, 2015 ). Thus, one of the main functions of the eCB 2-AG, degraded by the enzyme monoacylglycerol lipase (MAGL, Aaltonen et al, 2016 ), is to serve as a mediator of retrograde signaling to downregulate neurotransmitter release ( Smith et al, 2017 ). Unlike the selective presynaptic inhibitory effect of adenosine on excitatory glutamatergic terminals ( Safiulina et al, 2005 ), activation of CB1 receptor by eCB inhibits the release from presynaptic terminals of both inhibitory and excitatory neurotransmitters ( Gabrielli et al, 2015 ; Iseger and Bossong, 2015 ).…”

“…This complexity may explain why increased doses of cannabinoids diminished their analgesic effect ( Kandasamy et al, 2018 ). It further creates an incentive for development of new synthetic CBs with minimal activity on TRPV1 receptors, or specific MAGL inhibitors, which, apart from triggering the accumulation of anti-nociceptive 2-AG, can decrease the level of the pro-nociceptive arachidonic acid (AA) and reduce pain ( Aaltonen et al, 2016 ). MAGL inhibitors may also reduce the pro-nociceptive downstream products of AA such as endovanilloids, agonists of TRPV1 receptors ( Hwang et al, 2000 ).…”

Cannabinoids affect the mouse visual acuity via the cannabinoid receptor type 2

“…In this set of experiments, the inhibitors JJKK048, RHC80267 and URB597, respectively targeting the enzymes MAGL, DAGL and FAAH, were injected 30 min before assessing the visual acuity. By blocking the enzymes MAGL and FAAH, a rapid rise in 2-AG and AEA levels occurs 10,11 , while the inhibition of DAGL causes a decrease in 2-AG levels 12 . The inhibitor JJKK048 (4 mg/kg) strongly decreased visual acuity while the RHC80267 (10 mg/kg) enhanced it ( Fig.…”