CB2 cannabinoid receptor agonists attenuate TNF-alpha-induced human vascular smooth muscle cell proliferation and migration.
OBJECTIVE
Vascular smooth muscle proliferation and migration triggered by inflammatory stimuli are involved in the development and progression of atherosclerosis and restenosis. Cannabinoids may modulate cell proliferation in various cell types through cannabinoid 2 (CB2) receptors. Here, we investigated the effects of CB2 receptor agonists on TNF-alpha-induced proliferation, migration and signal transduction in human coronary artery smooth muscle cells (HCASMCs).


METHODS
HCASMCs were stimulated with TNF-alpha. Smooth muscle proliferation was determined by the extent of BrdU incorporation and the migration was assayed by modified Boyden chamber. CB2 and/or CB1 receptor expressions were determined by immunofluorescence staining, western blotting, RT-PCR, real-time PCR and flow cytometry.


RESULTS
Low levels of CB2 and CB1 receptors were detectable in HCASMCs compared to the high levels of CB2 receptors expressed in THP-1 monocytes. TNF-alpha triggered up to approximately 80% increase (depending on the method used) in CB2 receptor mRNA and/or protein expression in HCASMCs, and induced Ras, p38 MAPK, ERK 1/2, SAPK/JNK and Akt activation, while increasing proliferation and migration. The CB2 agonists, JWH-133 and HU-308, dose-dependently attenuated these effects of TNF-alpha.


CONCLUSIONS
Since the above-mentioned TNF-alpha-induced phenotypic changes are critical in the initiation and progression of atherosclerosis and restenosis, our findings suggest that CB2 agonists may offer a novel approach in the treatment of these pathologies by decreasing vascular smooth muscle proliferation and migration.
Rajesh
M
M
Section on Oxidative Stress Tissue Injury, Laboratory of Physiological Studies, National Institutes of Health, NIAAA, Bethesda, MD 20892-9413, USA.
Mukhopadhyay
P
P
Haskó
G
G
Huffman
J W
JW
Mackie
K
K
Pacher
P
P
D000906:Antibodies / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D005434:Flow Cytometry; D019085:Fluorescent Antibody Technique, Direct; D011905:Genes, ras / Q000187:drug effects; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000378:metabolism; D051058:Oncogene Protein v-akt / Q000235:genetics / Q000502:physiology; D043885:Receptor, Cannabinoid, CB2 / Q000819:agonists* / Q000096:biosynthesis / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors* / Q000235:genetics; D015854:Up-Regulation / Q000187:drug effects
D000906:Antibodies; D043885:Receptor, Cannabinoid, CB2; D014409:Tumor Necrosis Factor-alpha; D051058:Oncogene Protein v-akt; D020928:Mitogen-Activated Protein Kinases