Expression of CB₂ in murine HSPCs. (A) Expression of CB₂ in mouse BM cells. The surface expression of cannabinoid receptors was analyzed in total cells, non-SP (side population) cells, and SP cells. This is a representative experiment of 5 experiments. (B) Expression of CB₂ receptors on mouse LSK cells. Total BM cells were gated for lineage-negative cells (Lin⁻), followed by selection of c-kit/sca1 double-positive cells. CB₂ expression was determined in the LSK population. This is a representative experiment of 4 experiments. (C) Analysis of CB₂ mRNA expression in BM MNCs compared with isolated LSK and SLAM (LSK CD150⁺ CD48⁻) cells. RNA was isolated from the indicated murine populations of BM cells, and the expression of cannabinoid receptor mRNA was evaluated using the RT-PCR technique. Actin was used as an internal control.