“Molecular Mechanisms for the Inflammation-Resolving Actions of Lenabasum”

A first-in- class cannabinoid analog called lenabasum that is a CB2 agonist is being developed as an inflammation-resolving drug candidate. Thus far specific therapeutic targets include scleroderma, cystic fibrosis, dermatomyositis and lupus all of which represent unmet medical needs. Two somewhat independent molecular mechanisms for this type of action are here proposed. Both pathways initially involve the release of free arachidonic acid following activation of the CB2 receptor and PLA2 by lenabasum. The pathways then diverge into a COX-2 mediated and a lipoxygenase mediated route. The former leads to increased levels of the cyclopentenone prostaglandin 15-deoxy-Δ12,14-prostaglandin-J2 that can activate the NLPR3 inflammasome, which, in turn releases caspase-3 leading to apoptosis and the resolution of chronic inflammation. The lipoxygenase mediated pathway stimulates the production of lipoxin A4 as well as other signaling molecules called specialized pro-resolving mediators (SPMs). These also have inflammation-resolving actions. It is not well understood under which conditions each of these mechanisms operate and if there is cross-talk between them. Thus, much remains to be learned about the mechanisms describing the actions of lenabasum.

Significance Statement The resolution of chronic inflammation is a major unmet medical need. The synthetic non-psychoactive cannabinoid lenabasum could provide a safe and effective drug for this purpose. Two putative molecular mechanisms are suggested to better understand how lenabasum produces this action. In both different metabolites of arachidonic acid act as mediators.