The Cannabis sativa plant has been used for centuries as a recreational drug and more recently in the treatment of patients with neurological or psychiatric disorders. In many instances, treatment goals include relief from posttraumatic disorders, anxiety, or to support treatment of chronic pain. Ligands acting on cannabinoid receptor 1 (CB1R) are also potential targets for the treatment of other health conditions. Using an evidence-based approach, pharmacological investigation of CB1R agonists is timely, with the aim to provide chronically ill patients relief using well-defined and characterized compounds from cannabis. Hexahydrocannabinol (HHC), currently available over the counter in many countries to adults and even children, is of great interests to policy makers, legal administrators, and healthcare regulators, as well as pharmacologists. Herein, we studied the pharmacodynamics of HHC epimers, which activate CB1R. We compared their key CB1R-mediated signaling pathway activities and compared them to the pathways activated by Δ9-tetrahydrocannabinol (Δ9-THC). We provide evidence that activation of CB1R by HHC ligands is only broadly comparable to those mediated by Δ9-THC, and that both HHC epimers have unique properties. Together with the greater chemical stability of HHC compared to Δ9-THC, these molecules have a potential to become a part of modern medicine.

• MeSH
• agonisté kanabinoidních receptorů farmakologie   MeSH
• HEK293 buňky MeSH
• kanabinol farmakologie   MeSH
• lidé MeSH
• myši MeSH
• receptor kanabinoidní CB1 * metabolismus   agonisté   MeSH
• signální transdukce * účinky léků   MeSH
• tetrahydrokanabinol * farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• agonisté kanabinoidních receptorů MeSH
• kanabinol MeSH
• receptor kanabinoidní CB1 * MeSH
• tetrahydrokanabinol * MeSH

Cannabinoid receptor 1 (CB1R), a G protein-coupled receptor, plays a fundamental role in synaptic plasticity. Abnormal activity and deregulation of CB1R signaling result in a broad spectrum of pathological conditions. CB1R signaling is regulated by receptor desensitization including phosphorylation of residues within the intracellular C terminus by G protein-coupled receptor kinases (GRKs) that may lead to endocytosis. Furthermore, CB1R signaling is regulated by the protein Src homology 3-domain growth factor receptor-bound 2-like (SGIP1) that hinders receptor internalization, while enhancing CB1R association with β-arrestin. It has been postulated that phosphorylation of two clusters of serine/threonine residues, 425 SMGDS429 and 460 TMSVSTDTS468 , within the CB1R C-tail controls dynamics of the association between receptor and its interaction partners involved in desensitization. Several molecular determinants of these events are still not well understood. We hypothesized that the dynamics of these interactions are modulated by SGIP1. Using a panel of CB1Rs mutated in the aforementioned serine and threonine residues, together with an array of Bioluminescence energy transfer-based (BRET) sensors, we discovered that GRK3 forms complexes with Gβγ subunits of G proteins that largely independent of GRK3's interaction with CB1R. Furthermore, CB1R interacts only with activated GRK3. Interestingly, phosphorylation of two specific residues on CB1R triggers GRK3 dissociation from the desensitized receptor. SGIP1 increases the association of GRK3 with Gβγ subunits of G proteins, and with CB1R. Altogether, our data suggest that the CB1R signalosome complex is dynamically controlled by sequential phosphorylation of the receptor C-tail and is also modified by SGIP1.

• Klíčová slova
• G protein-coupled receptor kinase, G protein-coupled receptors, SGIP1, cannabinoid receptor 1, phosphorylation, β-arrestin,
• MeSH
• fosforylace MeSH
• kinetika MeSH
• proteiny vázající GTP * MeSH
• receptory kanabinoidní metabolismus   MeSH
• serin metabolismus   MeSH
• threonin metabolismus   MeSH
• transportní proteiny * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• proteiny vázající GTP * MeSH
• receptory kanabinoidní MeSH
• serin MeSH
• threonin MeSH
• transportní proteiny * MeSH