Differential Regulation of MMPs, Apoptosis and Cell Proliferation by the Cannabinoid Receptors CB1 and CB2 in Vascular Smooth Muscle Cells and Cardiac Myocytes.

Cannabinoids (CB) are implicated in cardiovascular diseases via the two main receptor subtypes CB ₁ R and CB ₂ R. This study investigated whether cannabinoids regulate the activity of matrix metalloproteases (MMP-2, MMP-9) in vascular smooth muscle cells (VSMCs) and in cells of cardiac origin (H9c2 cell line). The influence of CB ₁ - and CB ₂ receptor stimulation or inhibition on cell proliferation, apoptosis and glucose uptake was also evaluated. We used four compounds that activate or block CB receptors: arachidonyl-2-chloroethylamide (ACEA)-CB ₁ R agonist, rimonabant-CB ₁ R antagonist, John W. Huffman (JWH133)-CB ₂ R agonist and CB ₂ R antagonist-6-Iodopravadoline (AM630). Treatment of cells with the CB ₂ R agonist JWH133 decreased cytokine activated secretion of proMMP-2, MMP-2 and MMP-9, reduced Fas ligand and caspase-3-mediated apoptosis, normalized the expression of TGF-beta1 and prevented cytokine-induced increase in glucose uptake into the cell. CB ₁ R inhibition with rimonabant showed similar protective properties as the CB ₂ R agonist JWH133, but to a lesser extent. In conclusion, CB ₁ R and CB ₂ R exert opposite effects on cell glucose uptake, proteolysis and apoptosis in both VSMCs and H9c2 cells. The CB ₂ R agonist JWH133 demonstrated the highest protective properties. These findings may pave the way to a new treatment of cardiovascular diseases, especially those associated with extracellular matrix degradation.