The Cannabinoid Receptor Type 1 Is Essential for Mesenchymal Stem Cell Survival and Differentiation: Implications for Bone Health
Figure 2
Δ9-THC negatively affects MSC viability and inhibits MSC osteogenesis. (a) Treatment of undifferentiated MSCs with Δ9-THC (1 μM) significantly reduced viability compared to control undifferentiated MSCs (Con; *, 1-way ANOVA and Newman-Keuls, ). Also, differentiation of MSCs in the presence of Δ9-THC significantly decreased viability compared to control differentiated MSCs (Con; +, 1-way ANOVA and Newman-Keuls, ). (b) Treatment of undifferentiated MSCs with Δ9-THC induced a significant increase in the percentage of apoptotic nuclei compared to control MSCs (Con; ***, 1-way ANOVA and Newman-Keuls, ). Also, differentiation of MSCs in the presence of Δ9-THC significantly increased the percentage of apoptotic nuclei compared to control differentiated MSCs (++, 1-way ANOVA and Newman-Keuls, ). (c) Representative images of cells stained for active caspase-3 in control undifferentiated MSCs (i), undifferentiated MSCs treated with Δ9-THC (ii), control differentiated MSCs (iii), and differentiated MSCs in the presence of Δ9-THC (iv). (d) Differentiation of MSCs in the presence of Δ9-THC (1 μM) significantly decreased hydroxyapatite deposits compared to control differentiated MSCs (+++, 1-way ANOVA and Newman-Keuls, ).