Cannabinoid actions at TRPV channels: effects on TRPV3 and TRPV4 and their potential relevance to gastrointestinal inflammation

• Published in: Acta Physiologica 2012-02, Vol.204 (2), p.255-266
• Main Authors: De Petrocellis, L., Orlando, P., Moriello, A. Schiano, Aviello, G., Stott, C., Izzo, A. A., Di Marzo, V.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Calcium - metabolism; Cannabidiol - chemistry; Cannabidiol - pharmacology; cannabinoids; Cannabinoids - chemistry; Cannabinoids - pharmacology; Dronabinol - chemistry; Dronabinol - pharmacology; endocannabinoids; Fundamental and applied biological sciences. Psychology; Gastrointestinal Diseases - chemically induced; Gastrointestinal Diseases - metabolism; HEK293 Cells; Humans; Inflammation - chemically induced; Inflammation - metabolism; intestine; Intestine, Small - metabolism; Mice; Rats; receptor; TRP channels; TRPV Cation Channels - genetics; TRPV Cation Channels - metabolism; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 1748-1708; 1748-1716
• DOI: 10.1111/j.1748-1716.2011.02338.x

Aim:  Plant cannabinoids, like Δ9‐tetrahydrocannabinol (THC) and cannabidiol (CBD), activate/desensitize thermosensitive transient receptor potential (TRP) channels of vanilloid type‐1 or ‐2 (TRPV1 or TRPV2). We investigated whether cannabinoids also activate/desensitize two other ‘thermo‐TRP’s’, the TRP channels of vanilloid type‐3 or ‐4 (TRPV3 or TRPV4), and if the TRPV‐inactive cannabichromene (CBC) modifies the expression of TRPV1–4 channels in the gastrointestinal tract. Methods:  TRP activity was assessed by evaluating elevation of [Ca2+]i in rat recombinant TRPV3‐ and TRPV4‐expressing HEK‐293 cells. TRP channel mRNA expression was measured by quantitative RT‐PCR in the jejunum and ileum of mice treated with vehicle or the pro‐inflammatory agent croton oil. Results:  (i) CBD and tetrahydrocannabivarin (THCV) stimulated TRPV3‐mediated [Ca2+]i with high efficacy (50–70% of the effect of ionomycin) and potency (EC50∼3.7 μm), whereas cannabigerovarin (CBGV) and cannabigerolic acid (CBGA) were significantly more efficacious at desensitizing this channel to the action of carvacrol than at activating it; (ii) cannabidivarin and THCV stimulated TRPV4‐mediated [Ca2+]i with moderate‐high efficacy (30–60% of the effect of ionomycin) and potency (EC50 0.9–6.4 μm), whereas CBGA, CBGV, cannabinol and cannabigerol were significantly more efficacious at desensitizing this channel to the action of 4‐α‐phorbol 12,13‐didecanoate (4α‐PDD) than at activating it; (iii) CBC reduced TRPV1β, TRPV3 and TRPV4 mRNA in the jejunum, and TRPV3 and TRPV4 mRNA in the ileum of croton oil‐treated mice. Conclusions:  Cannabinoids can affect both the activity and the expression of TRPV1–4 channels, with various potential therapeutic applications, including in the gastrointestinal tract.