Liao James K
Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02139, USA.
Curr Opin Lipidol. 2005 Dec;16(6):624-9. doi: 10.1097/01.mol.0000191913.16321.60.
Atherosclerosis is a multi-factorial condition involving dyslipidemia that can result in cardiovascular disease. Statins are potent inhibitors of cholesterol biosynthesis, and in clinical trials, statins have been shown to be beneficial in the primary and secondary prevention of coronary heart disease. However, the overall benefits observed with statins appear to occur much earlier and to be greater than what might be expected from changes in lipid levels alone, suggesting effects beyond cholesterol lowering.
Recent studies indicate that some of the cholesterol-independent or 'pleiotropic' effects of statins involve improving endothelial function, enhancing the stability of atherosclerotic plaques, decreasing oxidative stress and inflammation, and inhibiting the thrombogenic response. Many of these pleiotropic effects are mediated by inhibition of isoprenoids, which serve as lipid attachments for intracellular signaling molecules. In particular, inhibition of small GTP-binding proteins, Rho, Ras, and Rac, whose proper membrane localization and function are dependent upon isoprenylation, may play an important role in mediating the pleiotropic effects of statins.
The potential clinical implications of statin pleiotropy suggests that perhaps other biomarkers, in addition to lipid levels, should be used to gauge the full efficacy of statin therapy in patients with cardiovascular risks or that statin therapy may be effective in disease states, such as inflammatory conditions, ischemic stroke or cancer, where elevated cholesterol levels have not been shown to be a strong epidemiological risk for these diseases.
动脉粥样硬化是一种涉及血脂异常的多因素病症,可导致心血管疾病。他汀类药物是胆固醇生物合成的强效抑制剂,在临床试验中,他汀类药物已被证明对冠心病的一级和二级预防有益。然而,他汀类药物所观察到的总体益处似乎出现得更早且大于仅由血脂水平变化所预期的效果,这表明其作用超出了降低胆固醇的范畴。
近期研究表明,他汀类药物的一些非胆固醇依赖性或“多效性”作用包括改善内皮功能、增强动脉粥样硬化斑块的稳定性、降低氧化应激和炎症以及抑制血栓形成反应。这些多效性作用许多是由类异戊二烯的抑制介导的,类异戊二烯作为细胞内信号分子的脂质附着基团。特别是,抑制小GTP结合蛋白Rho、Ras和Rac,其正常的膜定位和功能依赖于异戊二烯化,可能在介导他汀类药物的多效性作用中起重要作用。
他汀类药物多效性的潜在临床意义表明,除了血脂水平外,或许还应使用其他生物标志物来评估他汀类药物治疗对有心血管风险患者的全面疗效,或者他汀类药物治疗可能对某些疾病状态有效,如炎症性疾病、缺血性中风或癌症,在这些疾病中胆固醇水平升高尚未被证明是这些疾病的强大流行病学风险因素。