Targeting cannabinoid receptor 2 (CB2) limits collagen production-An in vitro study in a primary culture of human fibroblasts

Autores da FMUP

• Maria Paula De Valadares Souto Pinto Serrão

  Autor

• Maria Augusta Vieira Coelho

  Autor

Participantes de fora da FMUP

• Correia Sa, I
• Carvalho, C
• Machado, VA
• Carvalho, S
• Marques, M.

Unidades de investigação

• Biomedicina

Abstract

Previous studies showed that cannabinoid 2 (CB2) receptor is involved in skin inflammation, fibrogenesis and re-epithelialization in mice, indicating that this receptor may be implicated in wound healing. Thus, topical use of cannabinoids may have a role in local fibrotic and wound healing diseases such as scars or keloids. We investigate the effect of the CB2 selective receptor agonist (6aR,10aR)-3-(1,1-Dimethylbutyl)-6a,7,10,10a-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran (JWH133) and the CB2 selective receptor antagonist (6-Iodo-2-methyl-1-[2-(4-morpholinyl)ethyl]-1H-indol-3-yl)(4-methoxyphenyl)-methanone (AM630), on primary cultures of human fibroblasts. Primary cultures of adult human fibroblasts were obtained from abdominal human skin samples. Fibroblasts pretreated with JWH133 and/or AM630 were stimulated with TGF-beta (10 ng/ml). Fibroblast activation into myofibroblasts was quantified by the expression of alpha-smooth muscle actin (alpha-SMA) using Immunocytochemistry and Western Blot assays. Collagen content was quantified with the Sirius red staining assay. Upon human fibroblasts stimulation with TGF-beta, a significant increase on alpha-SMA and CB2 receptor expression was observed. In these cells, JWH133 decreased alpha-SMA expression and collagen content. However, this effect was not observed in resting human fibroblasts. AM630 decreased alpha-SMA expression and collagen content in both resting and activated fibroblasts. This effect was time- and concentration-dependent with an IC50 value of 11 mu M. The CB2 receptor appears to be involved in fibroblast repair during skin wound healing in humans, as TGF-beta increases CB2 receptor expression and JWH133 produces an anti-fibrotic effect in human fibroblasts. AM630 also showed an anti-fibrotic effect hypothesizing that other cannabinoid receptors, such as TRPV, may be involved in this response.

Keywords

• cannabinoid; CB2; fibroblast; fibrosis; scar; wound healing