专题：Nature系列
动脉粥样硬化（atheroma)是一组动脉硬化的血管病中常见的最重要的一种，其特点是受累动脉病变从内膜开始。一般先有脂质和复合糖类积聚、出血及血栓形成，纤维组织增生及钙质沉着，并有动脉中层的逐渐蜕变和钙化，病变常累及弹性及大中等肌性动脉，一旦发展到足以阻塞动脉腔，则该动脉所供应的组织或器官将缺血或坏死。由于在动脉内膜积聚的脂质外观呈黄色粥样，因此称为动脉粥样硬化。
对吃高胆固醇食物、易患动脉粥样硬化症的（缺少“载脂蛋白E”的）小鼠所做一项研究表明，小胆固醇晶体会出现在动脉粥样硬化的最早阶段，而且这些晶体能激发吞噬细胞中的NLRP3炎性体。
这表明，减少胆固醇沉积或阻断炎性体通道的治疗策略可能具有抗动脉粥样硬化效果。
生物谷推荐原文出处：
Nature doi:10.1038/nature08938
NLRP3 inflammasomes are required for atherogenesis and activated by cholesterol crystals
Peter Duewell,Hajime Kono,Katey J. Rayner,Cherilyn M. Sirois,Gregory Vladimer,Franz G. Bauernfeind,George S. Abela,Luigi Franchi,Gabriel Nu?ez,Max Schnurr,Terje Espevik,Egil Lien,Katherine A. Fitzgerald,Kenneth L. Rock,Kathryn J. Moore,Samuel D. Wright,Veit Hornung" Eicke Latz
The inflammatory nature of atherosclerosis is well established but the agent(s) that incite inflammation in the artery wall remain largely unknown. Germ-free animals are susceptible to atherosclerosis, suggesting that endogenous substances initiate the inflammation1. Mature atherosclerotic lesions contain macroscopic deposits of cholesterol crystals in the necrotic core, but their appearance late in atherogenesis had been thought to disqualify them as primary inflammatory stimuli. However, using a new microscopic technique, we revealed that minute cholesterol crystals are present in early diet-induced atherosclerotic lesions and that their appearance in mice coincides with the first appearance of inflammatory cells. Other crystalline substances can induce inflammation by stimulating the caspase-1-activating NLRP3 (NALP3 or cryopyrin) inflammasome2, 3, which results in cleavage and secretion of interleukin (IL)-1 family cytokines. Here we show that cholesterol crystals activate the NLRP3 inflammasome in phagocytes in vitro in a process that involves phagolysosomal damage. Similarly, when injected intraperitoneally, cholesterol crystals induce acute inflammation, which is impaired in mice deficient in components of the NLRP3 inflammasome, cathepsin B, cathepsin L or IL-1 molecules. Moreover, when mice deficient in low-density lipoprotein receptor (LDLR) were bone-marrow transplanted with NLRP3-deficient, ASC (also known as PYCARD)-deficient or IL-1α/β-deficient bone marrow and fed on a high-cholesterol diet, they had markedly decreased early atherosclerosis and inflammasome-dependent IL-18 levels. Minimally modified LDL can lead to cholesterol crystallization concomitant with NLRP3 inflammasome priming and activation in macrophages. Although there is the possibility that oxidized LDL activates the NLRP3 inflammasome in vivo, our results demonstrate that crystalline cholesterol acts as an endogenous danger signal and its deposition in arteries or elsewhere is an early cause rather than a late consequence of inflammation. These findings provide new insights into the pathogenesis of atherosclerosis and indicate new potential molecular targets for the therapy of this disease.
