| First Author | Stachon P | Year | 2017 |
| Journal | Circulation | Volume | 135 |
| Issue | 25 | Pages | 2524-2533 |
| PubMed ID | 28377486 | Mgi Jnum | J:265380 |
| Mgi Id | MGI:6197652 | Doi | 10.1161/CIRCULATIONAHA.117.027400 |
| Citation | Stachon P, et al. (2017) P2X7 Deficiency Blocks Lesional Inflammasome Activity and Ameliorates Atherosclerosis in Mice. Circulation 135(25):2524-2533 |
| abstractText | BACKGROUND: Extracellular adenosine triphosphate (ATP) binds as a danger signal to purinergic receptor P2X7 and promotes inflammasome assembly and interleukin-1beta expression. We hypothesized a functional role of the signal axis ATP-P2X7 in inflammasome activation and the chronic inflammation driving atherosclerosis. METHODS: P2X7-competent and P2X7-deficient macrophages were isolated and stimulated with lipopolysaccharide, ATP, or both. To assess whether P2X7 may have a role in atherosclerosis, P2X7 expression was analyzed in aortic arches from low density lipoprotein receptor(-/-) mice consuming a high-cholesterol or chow diet. P2X7(+/+) and P2X7(-/-) low density lipoprotein receptor(-/-) mice were fed a high-cholesterol diet to investigate the functional role of P2X7 knockout in atherosclerosis. Human plaques were derived from carotid endarterectomy and stained against P2X7. RESULTS: Lipopolysaccharide or ATP stimulation alone did not activate caspase 1 in isolated macrophages. However, priming with lipopolysaccharide, followed by stimulation with ATP, led to an activation of caspase 1 and interleukin-1beta in P2X7-competent macrophages. In contrast, P2X7-deficient macrophages showed no activation of caspase 1 after sequential stimulation while still expressing a basal amount of interleukin-1beta. P2X7 receptor was higher expressed in murine atherosclerotic lesions, particularly by lesional macrophages. After 16 weeks of a high-cholesterol diet, P2X7-deficient mice showed smaller atherosclerotic lesions than P2X7-competent mice (0.162 cm(2)+/-0.023 [n=9], P2X7(-/-) low density lipoprotein receptor(-/-) : 0.084 cm(2)+/-0.01 [n=11], P=0.004) with a reduced amount of lesional macrophages. In accord with our in vitro findings, lesional caspase 1 activity was abolished in P2X7(-/-) mice. In addition, intravital microscopy revealed reduced leukocyte rolling and adhesion in P2X7-deficient mice. Last, we observe increased P2X7 expression in human atherosclerotic lesions, suggesting that our findings in mice are relevant for human disease. CONCLUSIONS: P2X7 deficiency resolved plaque inflammation by inhibition of lesional inflammasome activation and reduced experimental atherosclerosis. Therefore, P2X7 represents an interesting potential new target to combat atherosclerosis. |
