Study: The role of cannabinoid receptors on inflammatory cells in canine atopic dermatitis
Date of publication: September 19, 2023
Translation: MVZ Flor Ortiz
Edition: ICAN Publishing House
Background
Atopic dermatitis (AD) is one of the most common inflammatory and pruritic skin diseases in dogs; it is multifactorial in nature. As such, AD can be a difficult disease to manage and often the therapeutic strategy is multimodal.
In recent years, research has progressed towards the use of natural products with beneficial effects on inflammation and itching and without side effects. Through various studies, it has been shown that cannabinoid receptors are expressed in healthy and diseased skin.
Target
To immunohistochemically investigate the expression of cannabinoid receptor type 2 (CB2) and cannabinoid-related receptors, such as G protein-coupled receptor 55 (GPR55), transient receptor potential vanilloid 1 (TRPV1) and transient receptor potential vanilloid 1 (TRPV1) and transient receptor protein ankyrin 1 (TRPA1) in mast cells (MC), macrophages, dendritic cells (DC), T cells and neutrophils from the skin of dogs with DA.
Materials and methods
Immunofluorescence-stained cryosections of skin from 8 dogs with AD that had antibodies against CB2R, GPR55, TRPV1, TRPA1 were evaluated semiquantitatively. Inflammatory cells were identified using antibodies against tryptase (mast cells), ionized calcium binding adaptor molecule 1 (IBA1) (macrophages/CD), CD3 (T cells) and calprotectin (neutrophils). The proportions of MC, macrophages/CD, T cells and neutrophils expressing CB2R, GPR55, TRPV1 and TRPA1 were evaluated.
Results
Inflammatory infiltrate cells showed immunoreactivity (IR) for all or some of the cannabinoid and cannabinoid-related receptors studied.
MCs and macrophages/DCs showed CB2R, GPR55, TRPA1 and TRPV.
T cells showed CB2R, GPR55 and TRPA1-IR.
Neutrophils expressed GPR55-IR. Colocalization studies indicated that CB2R-IR was coexpressed with TRPV1-, TRPA1- and GPR55-IR in different cellular elements of the dermis of AD dogs.
Conclusions and clinical significance
Cannabinoid receptor 2 and cannabinoid-related receptors GPR55, TRPV1 and TRPA1 were widely expressed in the inflammatory infiltrate of dogs with AD. Based on the current findings, SEC could be considered a potential therapeutic target for dogs with AD and may mitigate itching and inflammation.
Reference
Chiocchetti, R., Salamanca, G., De Silva, M., Gobbo, F., Aspidi, F., Cunha, R. Z., Galiazzo, G., Tagliavia, C., Sarli, G., & Morini, M. (2022). Cannabinoid receptors in the inflammatory cells of canine atopic dermatitis. Frontiers in veterinary science, 9. https://doi.org/10.3389/fvets.2022.987132. https://doi.org/10.3389/fvets.2022.987132
