蛋白激酶B-糖原合成激酶3β信号通路与瓣膜病心房纤颤发生的关系

发布时间：2018-06-29 21:12

本文选题：心房纤颤 + 钙调神经磷酸酶　；参考：《山东大学》2017年硕士论文

【摘要】：研究背景随着我国人口结构老龄化,心房纤颤(atrial fibrillation,AF)的发生率逐渐提高。瓣膜性心脏病伴发房颤时,栓塞和心衰的风险成倍增加,成为家庭和社会巨大的医疗负担。目前关于房颤的发生有很多假说,比如心肌结构重塑,局灶冲动连续发放,多发折返环,以及离子通道电流失常等等。但是,准确的发病机制仍未完全清楚。近年来,钙调神经磷酸酶(Calcineurin,CaN)因在心肌肥厚中发挥重要作用备受关注。CaN是一种Ca2+/钙调蛋白依赖的蛋白磷酸酶,可将细胞浆中的活化T细胞核因子(Nuclear Factor of Activated T-cells,NFAT)去磷酸化从而使其激活,活化的NFAT转入细胞核,启动心肌肥厚基因的表达。与此作用相反的是,糖原合成激酶3β(glycogen synthase kinase 3β,GSK3β)又可将NFAT磷酸化使其失活,促进NFAT转出细胞核,中断肥厚基因表达。蛋白激酶B(Protein kinase B,Akt/PKB)是GSK3β上游一个强有力的调节因子,当Akt第473位丝氨酸(Ser-473)被磷酸化,转变成活化形式p-Akt,p-Akt可将GSK3β位于N端的第9位丝氨酸(Ser-9)磷酸化,使其转变成无活性的p-GSK3β。最近,有研究表明CaN-NFAT通路参与了房颤的发生。基于CaN-NFAT通路和GSK3β-NFAT通路在心肌肥厚过程中的交叉关系,我们推测直接影响NFAT活性的Akt-GSK3β通路也可能参与了房颤的发生过程。然而,关于瓣膜性房颤中Akt-GSK3β信号通路的研究数据有限,尤其是人类中更少。因此,设计这个实验用来探究Akt-GSK3β信号通路是否参与人类瓣膜性房颤的发生。研究目的探讨Akt-GSK3β信号通路与瓣膜性房颤发生的关系。研究方法研究对象包括42名接受心脏换瓣手术的成人瓣膜病患者,按患者的心律状况分为2组:心房纤颤组(n=18),窦性心律组(n=24),手术前收集患者的一般资料及辅助检查的数据。通过蛋白免疫印迹法检测患者左心房心肌组织中钙调神经磷酸酶(CaN),总蛋白激酶B(total Akt),磷酸化蛋白激酶B(p-Akt),总糖原合成激酶3β(total GSK3β)和磷酸化糖原合成激酶3β(p-GSK3β)的蛋白表达水平,以磷酸甘油醛脱氢酶(GAPDH)为内参,所得条带灰度值的比值作为以上蛋白表达的相对含量。研究结果1.临床特征方面的分析:两组病人在性别、年龄、血压、BMI等方面,未见统计学差异(P均0.05);但房颤组病人的心率、BNP明显高于窦律组,其差异具有统计学意义(P均0.05)。2.服用药物方面的分析:房颤组病人服用β阻剂和地高辛的比率高于窦律组,其差异具有统计学意义(P均0.05);其他药物方面未见统计学差异(P均0.05)。3.心功能方面的分析:房颤组病人的心功能较窦律组差,具体表现在左心室射血分数偏低,其差异具有统计学意义(P0.05)。4.两组样本中Akt-GSK3β及CaN蛋白表达情况分析:以GAPDH为参照,房颤组活化形式的p-Akt、非活化形式的p-GSK3β及总GSK3β蛋白表达水平均高于窦性心律组(p-Akt 1.027±0.126 vs 0.729±0.113,P0.001;p-GSK3β0.802±0.116 vs 0.482±0.076,P0.001;total GSK3β 1.047±0.162 vs 0.703±0.109,P0.001),其差异具有统计学意义,提示房颤心房肌活化形式的p-Akt蛋白表达增加,使GSK3β变成失活形式的p-GSK3β增加,从而使NFAT从细胞核转出核外的作用减弱,促进了房颤的发生。此外,两组样本之间总Akt(1.074±0.089 vs 1.028±0.0945,P=0.124)的蛋白表达水平未见统计学差异。房颤组中CaN(1.097±0.153 vs 0.919±0.142,P0.001)的蛋白表达水平高于窦律组。研究结论蛋白激酶B-糖原合成激酶3β信号通路参与了瓣膜性房颤的发生。
[Abstract]:Background: the incidence of atrial fibrillation (AF) is increasing with the aging of the population structure in our country. The risk of embolism and heart failure is multiplied times when valvular heart disease is associated with atrial fibrillation. There are many hypotheses about the occurrence of atrial fibrillation, such as the remodeling of myocardial structure, and the focal impact. Continuous distribution, multiple reentry rings, and ion channel current aberration and so on. But the exact pathogenesis is still not completely clear. In recent years, Calcineurin (CaN) plays an important role in cardiac hypertrophy. It is concerned that.CaN is a Ca2+/ calmodulin dependent protein phosphatase, which can activate T in the cytoplasm. Nuclear Factor of Activated T-cells (NFAT) is dephosphorylated to activate it, and the activated NFAT is transferred into the nucleus and activates the expression of the hypertrophic gene of the myocardium. In contrast, the glycogen synthesis kinase 3 beta (glycogen synthase kinase 3 beta, GSK3 beta) can also phosphorylate the NFAT, and promote the transfer of the nucleus to the nucleus. Protein kinase B (Protein kinase B, Akt/PKB) is a powerful regulator in the upstream of GSK3 beta. When Akt 473rd serine (Ser-473) is phosphorylated and transformed into active form p-Akt, p-Akt can phosphorylate the ninth bit serine of GSK3 beta at the N end and turn it into an inactive beta. Recently, a study table The CaN-NFAT pathway is involved in the occurrence of atrial fibrillation. Based on the cross relationship between the CaN-NFAT pathway and the GSK3 beta -NFAT pathway in the process of myocardial hypertrophy, we speculate that the Akt-GSK3 beta pathway that directly affects the NFAT activity may also be involved in the process of atrial fibrillation. However, the data on the Akt-GSK3 beta signaling pathway in valvular atrial fibrillation is limited, especially in the case of valvular atrial fibrillation. This experiment is designed to explore whether the Akt-GSK3 beta signaling pathway is involved in valvular atrial fibrillation. The purpose of this study is to explore the relationship between the Akt-GSK3 beta signaling pathway and valvular atrial fibrillation. The research object included 42 adult valvular patients who underwent cardiac valve replacement surgery, according to the heart rhythm of the patients. The conditions were divided into 2 groups: the atrial fibrillation group (n=18), the sinus rhythm group (n=24), the general data of the patients before the operation and the data of the auxiliary examination. The protein immunoblotting was used to detect the calcineurin (CaN), the total protein kinase B (total Akt), the phosphorylated protein kinase B (p-Akt), the total glycogen kinase 3 beta (total G) in the left atrial myocardium of the patients. SK3 beta and phosphorylated glycogen synthesis kinase 3 beta (p-GSK3 beta) protein expression level, glyceraldehyde phosphate dehydrogenase (GAPDH) as the internal parameter, the ratio of gray value of the bands as the relative content of the above protein expression. Study results 1. clinical characteristics of the analysis: two groups of patients in sex, age, blood pressure, BMI and so on, no statistical difference (P All 0.05), but the heart rate of the patients with atrial fibrillation was significantly higher than that in the sinus rhythm group, and the difference was statistically significant (P 0.05).2. medication analysis: the ratio of beta blockers and digoxin in the atrial fibrillation group was higher than that in the sinus rhythm group, and the difference was statistically significant (P 0.05), and there was no statistical difference between other drugs (P 0.05).3. cardiac work Analysis of energy: the heart function of the patients with atrial fibrillation is worse than that in the sinus rhythm group, and the specific expression is that the left ventricular ejection fraction is low. The difference is statistically significant (P0.05) the expression of Akt-GSK3 beta and CaN in the samples of.4. two groups: GAPDH as the reference, the activation of p-Akt in the atrial fibrillation group, the expression of the non activated p-GSK3 beta and the total GSK3 beta protein expression The levels were higher than that in the sinus rhythm group (p-Akt 1.027 + 0.126 vs 0.729 + 0.113, P0.001, p-GSK3 beta 0.802 + 0.116 vs 0.482 + 0.076, P0.001, total GSK3 beta 1.047 + 0.162 vs 0.703 + 0.109, P0.001), and the difference was statistically significant, suggesting that the expression of p-Akt protein in atrial fibrillation of atrial fibrillation increased. In addition, the role of NFAT from the nucleus out of the nucleus weakened and promoted the occurrence of atrial fibrillation. In addition, the protein expression level of total Akt (1.074 + 0.089 vs 1.028 + 0.0945, P=0.124) between the two groups was not statistically significant. The protein expression level of CaN (1.097 + 0.153 vs 0.919 + 0.142, P0.001) in the atrial fibrillation group was higher than that in the sinus rhythm group. The white kinase B- glycogen synthase kinase 3 beta signaling pathway is involved in valvular atrial fibrillation.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R541.75

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