Glaucoma Harnessing the Endocannabinoid 2-Arachidonoylglycerol to Lower Intraocular Pressure in a Murine Model Sally Miller,1 Emma Leishman,1 Sherry Shujung Hu,2 Alhasan Elghouche,1 Laura Daily,1 Natalia Murataeva,1 Heather Bradshaw,1 and Alex Straiker1 1Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States 2Department of Psychology, National Cheng Kung University, Tainan, Taiwan Correspondence: Alex Straiker, De- PURPOSE. Cannabinoids, such as D9-THC, act through an endogenous signaling system in the partment of Psychological and Brain vertebrate eye that reduces IOP via CB1 receptors. Endogenous cannabinoid (eCB) ligand, 2- Sciences, Indiana University, Bloom- arachidonoyl glycerol (2-AG), likewise activates CB1 and is metabolized by monoacylglycerol ington, IN 47405, USA; lipase (MAGL). We investigated ocular 2-AG and its regulation by MAGL and the therapeutic
[email protected]. potential of harnessing eCBs to lower IOP. Submitted: February 16, 2016 Accepted: May 16, 2016 METHODS. We tested the effect of topical application of 2-AG and MAGL blockers in normotensive mice and examined changes in eCB-related lipid species in the eyes and spinal Citation: Miller S, Leishman E, Hu SS, cord of MAGL knockout (MAGLÀ/À) mice using high performance liquid chromatography/ et al. Harnessing the endocannabinoid tandem mass spectrometry (HPLC/MS/MS). We also examined the protein distribution of 2-arachidonoylglycerol to lower intra- ocular pressure in a murine model. MAGL in the mouse anterior chamber. Invest Ophthalmol Vis Sci. RESULTS. 2-Arachidonoyl glycerol reliably lowered IOP in a CB1- and concentration-dependent 2016;57:3287–3296. DOI:10.1167/ manner. Monoacylglycerol lipase is expressed prominently in nonpigmented ciliary iovs.16-19356 epithelium.