The phytocannabinoid, Δ(9) -tetrahydrocannabivarin, can act through 5-HT1 A receptors to produce antipsychotic effects

Funded by: •GW Pharmaceuticals Acknowledgements: The authors wish to thank Mrs Lesley Stevenson for technical support and Dr John Raymond, Dr Keith Parker and Dr Ethan Russo for providing human 5-HT1A CHO cells. This research was supported by a grant from GW Pharmaceuticals to M. G. C. and R. G. P.Peer reviewedPostprin

Inverse agonism at cannabinoid receptors

Abstract There are at least two types of cannabinoid receptor, CB 1 and CB 2 , both G protein coupled. CB 1 receptors are expressed predominantly at nerve terminals and mediate inhibition of transmitter release. CB 2 receptors are found mainly on immune cells, one of their roles being to modulate cytokine release. Endogenous ligands for these receptors (endocannabinoids) also exist. These discoveries have prompted the development of CB 1 -and CB 2 -selective agonists and antagonists. The latter include the CB 1 -selective SR141716A and LY320135 and the CB 2 -selective SR144528 and AM630, all of which appear to be inverse agonists. Indeed, antagonists without inverse agonist activity have yet to be developed. As most experiments directed at investigating inverse agonism at cannabinoid receptors have been performed with SR141716A, this review focusses on this agent. It presents evidence that the endocannabinoid system is tonically active and that this activity can stem both from ongoing release of endocannabinoids and from the presence of constitutively active CB 1 receptors. Thus, SR141716A seems to induce some inverse cannabimimetic effects by opposing responses to endogenously released endocannabinoids and other such effects by decreasing tonic activity induced by constitutively active CB 1 receptors. The interaction of SR141716A with constitutively active receptors is discussed in terms of ''two-state'' and ''three-state'' models.

Increasing levels of the endocannabinoid 2-AG is neuroprotective in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of Parkinson's disease

Date of Acceptance: 28/07/2015 The authors are grateful to the staff of the Medical Research Facility for their help with the animal care. This work was supported by the NHS Endowment fund 09/03 and the Wellcome Trust (WT080782MF). We thank Merck & Co. Inc., Rathway NJ, USA for the supply of DFU.Peer reviewedPublisher PD

Disease associated polymorphisms within the conserved ECR1 enhancer differentially regulate the tissue specific activity of the cannabinoid‐1 receptor gene promoter; implications for cannabinoid pharmacogenetics

EH was funded by Medical Research Scotland (PhD-719-2013) and GW Pharmaceuticals. AMcE was funded by BBSRC project grant (BB/N017544/1). PB and DW are funded by the Scottish Government Rural and Environment Science and Analytical Services Division to the Rowett Institute. The authors declare no conflicts of interest.Peer reviewedPublisher PD

Anticancer effects of n-3 EPA and DHA and their endocannabinoid derivatives on breast cancer cell growth and invasion

Acknowledgements We would like to acknowledge NHS Grampian Endowment funds and TENOVUS Scotland for funding. JL was funded by a scholarship from Fraserburgh Moonlight Prowl and AAS was funded by the Scottish Government’s Rural and Environment Science and Analytical Services Division (RESAS). We also thank Dr Raphael Mechoulam, University of Jerusalem, for the gift of the endocannabinoids.Peer reviewedPostprin

Identification of the first synthetic allosteric modulator of the CB2receptors and evidence of its efficacy for neuropathic pain relief

The direct activation of cannabinoid receptors (CBRs) results in several beneficial effects, therefore numerous CB1R and CB2R ligands have been developed and tested in vitro and in vivo, but none of them reached an advanced stage of clinical development due to several side effects in particular on the CNS. Medicinal chemistry approaches are now engaged to develop allosteric modulators that might offer a novel therapeutic approach to achieve potential therapeutic benefits avoiding inherent side effects of orthosteric ligands. Here we identify the first ever synthetized positive allosteric modulator (PAM) that targets CB2Rs. The evidence for this was obtained using [3H]CP55940 and [35S]GTPγS binding assays. This finding will be useful for the characterization of allosteric binding site(s) on CB2Rs which will be essential for the further development of CB2R allosteric modulators. Moreover, the new CB2R PAM displayed antinociceptive activity in vivo in an experimental mouse model of neuropathic pain, raising the possibility that it might be a good candidate for clinical development

Design, synthesis and biological evaluation of novel orthosteric-allosteric ligands of the cannabinoid receptor type 2 (CB2R)

It is well known that G protein–coupled receptors (GPCRs) assume multiple active states. Orthosteric ligands and/or allosteric modulators can preferentially stabilize specific conformations, giving rise to pathway-biased signaling. One of the most promising strategies to expand the repertoire of signaling-selective GPCR activators consists of dualsteric agents, which are hybrid compounds consisting of orthosteric and allosteric pharmacophoric units. This approach proved to be very promising showing several advantages over monovalent targeting strategies, including an increased affinity or selectivity, a bias in signaling pathway activation, reduced off-target activity and therapeutic resistance. Our study focused on the cannabinoid receptor type 2 (CB2R), considered a clinically promising target for the control of brain damage in neurodegenerative disorders. Indeed, CB2R was found highly expressed in microglial cells, astrocytes, and even in some neuron subpopulations. Here, we describe the design, synthesis, and biological evaluation of two new classes of potential dualsteric (bitopic) CB2R ligands. The new compounds were obtained by connecting, through different linkers, the pharmacophoric portion of the CB2R positive allosteric modulator (PAM), EC21a, with that of the CB2R selective orthosteric agonist LV62, both developed in our laboratories. A preliminary screening enabled us to identify compound JR64a as the most promising of the series. Indeed, functional examination highlighted a signaling ‘bias’ in favor of G protein activation over βarrestin2 recruitment, combined with high affinity for CB2R and the ability to efficiently prevent inflammation in human microglial cells (HMC3) exposed to LPS/TNFα stimulation, thus demonstrating great promise for the treatment of neurodegenerative diseases

Synthesis and In Vitro Characterization of Selective Cannabinoid CB2 Receptor Agonists: Biological Evaluation against Neuroblastoma Cancer Cells

1,8-naphthyridine-3-carboxamide structures were previously identified as a promising scaffold from which to obtain CB2R agonists with anticancer and anti-inflammatory activity. This work describes the synthesis and functional characterization of new 1,8-naphthyridin-2(1H)-one-3-carboxamides with high affinity and selectivity for CB2R. The new compounds were able to pharmacologically modulate the cAMP response without modulating CB2R-dependent beta-arrestin2 recruitment. These structures were also evaluated for their anti-cancer activity against SH-SY5Y and SK-N-BE cells. They were able to reduce the cell viability of both neuroblastoma cancer cell lines with micromolar potency (IC50 of FG158a = 11.8 mu M and FG160a = 13.2 mu M in SH-SY5Y cells) by a CB2R-mediated mechanism. Finally, in SH-SY5Y cells one of the newly synthesized compounds, FG158a, was able to modulate ERK1/2 expression by a CB2R-mediated effect, thus suggesting that this signaling pathway might be involved in its potential anti-cancer effect

Novel Electrophilic and Photoaffinity Covalent Probes for Mapping the Cannabinoid 1 Receptor Allosteric Site(s)

ACKNOWLEDGMENTS The work was supported by National Institutes of Health grants DA027113 and EY024717 to G.A.T. and DA09158 to A.M. A portion of this work was submitted in 2011 by A. Kulkarni in partial fulfillment of M.S. degree requirements from Northeastern University, Boston, MA.Peer reviewedPublisher PD

Synthesis, radio-synthesis and in vitro evaluation of terminally fluorinated derivatives of HU-210 and HU-211 as novel candidate PET tracers

We thank the EPSRC National Mass Spectrometry Service Centre (Swansea, UK), for performing HRMS analyses.Peer reviewedPostprin