Ruz-Maldonado, InmaculadaPingitore, AttilioLiu, BoAtanes, PatricioHuang, Guo CaiBaker, DavidAlonso, Francisco JoséBermúdez-Silva, Francisco JavierPersaud, Shanta J2023-01-252023-01-252018-01-10http://hdl.handle.net/10668/11877To examine the effects of Abn-CBD (GPR55 agonist) and LH-21 (CB1 antagonist) on human and mouse islet function, and to determine signalling via GPR55 using islets from GPR55-/- mice. Islets isolated from human organ donors and mice were incubated in the absence or presence of Abn-CBD or LH-21, and insulin secretion, [Ca2+ ]i, cAMP, apoptosis, β-cell proliferation and CREB and AKT phosphorylation were examined using standard techniques. Abn-CBD potentiated glucose-stimulated insulin secretion and elevated [Ca2+ ]i in human islets and islets from both GPR55+/+ and GPR55-/- mice. LH-21 also increased insulin secretion and [Ca2+ ]i in human islets and GPR55+/+ mouse islets, but concentrations of LH-21 up to 0.1 μM were ineffective in islets from GPR55-/- mice. Neither ligand affected basal insulin secretion or islet cAMP levels. Abn-CBD and LH-21 reduced cytokine-induced apoptosis in human islets and GPR55+/+ mouse islets, and these effects were suppressed after GPR55 deletion. They also increased β-cell proliferation: the effects of Abn-CBD were preserved in islets from GPR55-/- mice, while those of LH-21 were abolished. Abn-CBD and LH-21 increased AKT phosphorylation in mouse and human islets. This study showed that Abn-CBD and LH-21 improve human and mouse islet β-cell function and viability. Use of islets from GPR55-/- mice suggests that designation of Abn-CBD and LH-21 as a GPR55 agonist and a CB1 antagonist, should be revised.encannabinoidsinsulin secretionisletsproliferationβ-cell functionAdultAnimalsCells, CulturedFemaleHumansInsulin-Secreting CellsIslets of LangerhansMaleMiceMice, Inbred C57BLMice, KnockoutMiddle AgedReceptors, CannabinoidReceptors, G-Protein-CoupledResorcinolsSignal TransductionTriazolesresearch article29205751open access10.1111/dom.131801463-1326https://kclpure.kcl.ac.uk/portal/files/97046207/data_proof_2.pdf