氯吡格雷是心脑血管病抗血小板治疗的金标准药物之一，但仍有5～44%患者因氯吡格雷抵抗导致血栓等临床事件，其抵抗机制研究已成为热点，但目前仍有约80%抵抗机制不明确。申请人前期研究发现：CES1A1基因低甲基化通过上调CES1表达，促进氯吡格雷及其活性代谢物水解，从而导致氯吡格雷抵抗。鉴于PXR活化是调控CES1A1的主要途径，DNMTs抑制是基因去甲基化调控的主要机制，我们提出假说：DNMTs介导CES1A1去甲基化，通过激活PXR而上调CES1A1表达，促进氯吡格雷及其活性代谢物水解失活，从而导致氯吡格雷抵抗。本项目以DNA甲基化为切入点，拟研究DNMTs介导CES1A1甲基化状态差异，阐明影响PXR/RXR与CES1A1启动子相互作用而调控CES1A1表达并诱导氯吡格雷抵抗的关键因素，从临床、动物和细胞水平揭示抵抗的分子机制，预期结果可能揭示逆转抵抗的潜在药物靶标，具有重要的临床意义。

Clopidogrel is one of the gold standard drugs of antiplatelet therapy of cardiovascular and cerebrovascular disease. About 5 to 44% patients will have thrombosis clinical events because of clopidogrel resistance, and the mechanism of clopidogrel resistance has become a hot. However, nearly 80% of clopidogrel resistance mechanisms are unclear. The previous research findings of the applicant find that: CES1A1 hypomethylation promotes the hydrolytic inactivation of clopidogrel and its active metabolite by up-regulating CES1A1 expression, which causse clopidogrel resistance. Based on the fact that the activation of PXR is the major regulator of CES1A1 expression and DNMTs inhibition is the main mechanism to induce gene demethylation, we put forward the hypothesis: DNMTs mediates the demethylation of CES1A1, raises the CES1A1 expression through activation of PXR and promotes the hydrolytic inactivation of clopidogrel and its active metabolite, which leads to clopidogrel resistance. With DNA methylation as the breakthrough point, the project aims to clarify the various subtypes of DNMTs which mediates CES1A1 methylation differences and the interaction of PXR/RXR and CES1A1 promoter, leading to the modulated regulation of CES1A1 and eventually clopidogrel resistance. The project reveals the molecular mechanisms of clopidogrel resistance from clinical, animal and cellular levels. It may reveal the potential drug targets to overcome clopidogrel resistance with important clinical significance.