NADPH 氧化酶在心力衰竭患者心肌中的基因表达及其与心肌纤维化关系的研究

摘要

目的：探讨NADPH氧化酶（ Nox）在心力衰竭患者心肌中的基因表达及其与心肌纤维化的关系。方法采用Real-time PCR检测15例心力衰竭患者（心力衰竭组）和9例心脏移植供体（对照组）左心室心肌组织Nox mRNA表达水平，Western blot检测Nox及MAPKs信号途径磷酸化水平，丙二醛（ MDA）试剂盒检测心肌MDA含量，天狼猩红染色观察心肌纤维化程度。结果与对照组比较，心力衰竭组心肌MDA含量明显升高，分别为（6照．62±0．80） mmol／mg prot和（2．23±0．30）mmol／mg prot，差异有统计学意义（ t ＝－12．947， P ＜0．01）。心肌Nox4 mRNA表达水平明显上调（ t ＝－3．144， P ＜0．01），而Nox2及其亚基表达水平无明显变化；心肌纤维化程度明显增加（ t ＝－12．947、－23．102， P ＜0．01），同时MAPKs 信号途径（p38、ERK1／2、JNK）磷酸化水平明显增加（ t ＝－15．574、－12．434、－30．123， P ＜0．01）。结论心力衰竭患者心肌氧化应激水平增加，可能与Nox4表达增加有关。 Nox4通过激活MAPKs信号途径参与心肌纤维化过程，抑制Nox4可能降低心力衰竭患者心肌氧化应激和纤维化程度。%Objective To investigate the relationship between NADPH oxidase (Nox) expression and myocardial fi-brosis in heart failure patients.Methods Using Real-time PCR to detect left ventricular myocardium of Nox mRNA expression level in 15 cases with congestive heart failure (CHF group) and 9 cases of cardiac transplantation donor (control group). Western blot was used to detect Nox and MAPKs signaling pathway phosphorylation level, malondialdehyde (MDA) kit for the detection of myocardial MDA content and Sirius red staining to observe the degree of myocardial fibrosis.Results Compared with the control group, in heart failure group, the myocardial MDA content increased significantly, (6.62 ±0.80) mmol/mg-prot and (2.23 ±0.30) mmol/mgprot respectively, the difference has statistical significance ( t =-12.947, P <0.01). Myocardial Nox4 mRNA expression levels were significantly up-regulated ( t =-3.144, P <0.01), Nox2 and its subunit expression level had no obvious change; the degree of myocardial fibrosis was significantly increased ( t =-12.947, t =-23.102, P <0.01), and phosphorylation levels of MAPKs signal pathway(p38, ERK1/2 and JNK) significantly increased ( t =-15.574, t =-12.434, t =-30.123, P <0.01).Conclusion The heart failure with myocardial oxidative stress increase may upgrade the expression of Nox4.Nox4 is involved in myocardial fibrosis by activating MAPKs pathway, and in-hibiting Nox4 may reduce myocardial oxidative stress and fibrosis in patients with heart failure.