有氧康复运动通过上调EETs负向调控PCSK9的实验研究

Increased proprotein convertase subtilisin/kexin type 9 (PCSK9) in statin therapy partially withdraws the lowing-cholesterol effect of statins. Although PCSK9 antibody /inhibitors were available now, their application were restricted.. We found that, compared with control group, plasma PCSK9 were decreased obviously in coronary heart disease（CHD）patients with taking statins after aerobic rehabilitation exercise. Besides, low density lipoprotein (LDL-C) in those patients were improved better. but the mechanism is unknown.. We observed that aerobic exercise increased the concentration of epoxyeicosatrienoic acids (EETs) in plasma in CHD patients. Previously, we have proved that EETs had ablility to decrease LDL-C. Furthermore, we found that expression of PCSK9 was controled by EETs. Thus, it is hypothesized that aerobic exercise negatively regulates PCSK9 by raising EETs.. So firstly, We are planing to observe changes in EETs and PCSK concentration in CHD patients and high fat diet (HFD) hyperlipidemia mice after aerobic exercise. Then to verify that EETs take part in aerobic exercise regulating PCSK9 from multiple perspectives. Lastly, we need to clarify that EETs regulate PCSK9 by activating FoxO3a - Sirt6 axis.. This study will provide a new exploring ways to solve the problems appeared in the process of statin therapy, providing new evidence from basic research for cardiac rehabilitation therapy in CHD patients as well.

他汀治疗过程中出现前蛋白转化酶枯草溶菌素9(PCSK9)升高部分抵消了他汀降低低密度脂蛋白胆固醇(LDL-C)的作用,虽然PCSK9单抗/抑制剂能改善此负效应,但临床应用受限。前期我们发现有氧康复运动配合他汀治疗冠心病患者,能减少患者血中PCSK9含量，更好地改善 LDL-C水平；同时发现有氧运动上调血浆环氧二十碳三烯酸(EETs)浓度。我们已证明EETs具有降低LDL-C的作用，接着观察到PCSK9表达受EETs调控。由此设想有氧运动通过上调EETs发挥负向调控PCSK9效应。为此本研究首先观察冠心病患者及饮食性高脂血症小鼠进行有氧运动后EETs及PCSK9的变化,再从多角度验证EETs参与有氧运动对PCSK9的调控,进一步以FoxO3a-Sirt6轴为切入点阐明EETs调控PCSK9的分子机制。旨在为解决“他汀治疗过程中出现的PCSK9升高”难题提供新方法,为心脏康复治疗提供新的理论。

临床他汀治疗过程中伴随前蛋白转化酶枯草溶菌素9(PCSK9)表达升高而部分抵消他汀降低低密度脂蛋白胆固醇(LDL-C)水平的作用, 因而出现尽管他汀剂量加倍，但其降脂疗效仅增加6%的困境。虽然PCSK9抑制剂能改善此负效应，但价格昂贵且临床应用受限。前期我们发现在包含他汀的冠心病标准治疗基础上联合有氧运动, 能降低患者血浆PCSK9水平，进一步促进 LDL-C下降 ；同时发现有氧运动上调血浆环氧二十碳三烯酸(EETs)浓度。已知EETs具有降低LDL-C作用，由此推测有氧运动可能通过上调EETs发挥负向调控 PCSK9的作用。. 我们首先明确服用他汀的冠心病患者及饮食性高胆固醇血症（HFD）小鼠进行有氧运动后血浆PCSK9浓度下降、LDL-C下降、EETs浓度升高。接着，我们通过检测不同EETs浓度与作用时间及阻断EETs作用后对肝脏PCSK9的分泌及表达的影响，从而验证有氧运动通过上调EETs负向调控HFD小鼠PCSK9，增加LDL受体（LDLR）表达，从而促进LDL-C进一步下降，且不依赖于SREBP2途径。更重要的是，我们首次发现EETs增强剂TPPU可能通过影响肝脏LDLR的再分布并且增加LDLR对LDL的摄取而降低LDL-C。在机制的研究中，通过体内、外实验验证有氧运动通过升高EETs浓度进一步激动FoxO3a-Sirt6轴，FoxO3a活化后促使其入核与PCSK9基因结合，同时Sirt6被FoxO3a募集并结合于PCSK9基因远端启动子区域而负向调控PCSK9，进一步增加LDLR转运及表达，最终降低LDL-C水平。. 本研究验证了“有氧运动有益于血脂调控”理论，为解决“他汀治疗过程中出现的PCSK9升高”的临床难题提供新方法、为更好地管理冠心病患者的LDL-C开拓新的思路，为心脏康复治疗提供新的基础研究依据。