CB2 receptor antibody signal specificity: correlations with the use of partial CB2-knockout mice and anti-rat CB2 receptor antibodies.

CB2 receptor antibody signal specificity: correlations with the use of partial CB2-knockout mice and anti-rat CB2 receptor antibodies.
Acta Pharmacol Sin. 2018 Jul 02;:
Authors: Zhang HY, Shen H, Jordan CJ, Liu QR, Gardner EL, Bonci A, Xi ZX
Abstract
Cannabinoid CB1 receptors are highly expressed in the brain and functionally modulate presynaptic neurotransmitter release, while cannabinoid CB2 receptors (CB2Rs) were initially identified in the spleen and regarded as peripheral cannabinoid receptors. Recently, growing evidence indicates the presence of functional CB2Rs in the brain. However, this finding is disputed because of the specificity of CB2R antibody signals. We used two strains of currently available partial CB2-knockout (CB2-KO) mice as controls, four anti-rat or anti-mouse CB2R antibodies, and mRNA quantification to further address this issue. Western blot assays using the four antibodies detected a CB2R-like band at ~40 kD in both the brain and spleen. Notably, more bands were detected in the brain than in the spleen, and specific immune peptides blocked band detection. Immunohistochemical assays also detected CB2-like immunostaining in mouse midbrain dopamine neurons. CB2R deletion in CB2-KO mice may reduce or leave CB2R-like immunoreactivity unaltered depending on antibody epitope. Antibodies with epitopes at the receptor-deleted region detected a significant reduction in CB2R band density and immunostaining in N-term...

Source: Acta Pharmacologica Sinica - July 2, 2018 Category: Drugs & Pharmacology Authors: Zhang HY, Shen H, Jordan CJ, Liu QR, Gardner EL, Bonci A, Xi ZX Tags: Acta Pharmacol Sin Source Type: research