Dyrk1A经ASF调控CaMKⅡδ可变剪接在肾血管性高血压大鼠心肌肥厚中的作用

摘要

ATM; To investigate the role of dual - specificity tyrosine phosporylation -regulated kinase 1A (DyrklA) - alternative splicing factor (ASF) - calcium/calmodulin - dependent protein kinase II δ( CaMK II δ) pathway in the progression of myocardial hypertrophy in renovascular hypertensive rats . METHODS: The renovascular hypertension was induced by two -kidney one -clip (2K1C) method. The changes of blood pressure and myocardial hypertrophy were measured. The techniques of RT - PCR and Western blotting were used to detect CaMK II 8 alternative splicing and the protein expression of DyrklA and ASF, respectively. RESULTS; Eight weeks after operation , systolic blood pressure (SBP) and diastolic blood pressure (DBP) in 2K1C rats increased (P <0. 05). The increases in left ventricular weight (LVW) , the ratio of LVW to body weight (BW) and the area of myocardial cells indicated that the hypertensive rats developed sig -nificant cardiac hypertrophy. The protein expression of Dyrkl A and mRNA expression of CaMK II 8A and 8B were significantly increased, while the protein expression of ASF and mRNA expression of CaMK II 8C were decreased compared with sham - operated control rats (P<0.05). Treatment with DryklA inhibitor epigallocatechin gallate (EGCG) or harmine effectively attenuated cardiac hypertrophy and reversed the changes in the protein expression of Dyrk 1A, ASF and alternative splicing of CaMK II 8 ( all P < 0. 05 ) . CONCLUSION: Dyrkl A - ASF - CaMK II 8 pathway plays a role in the develop -ment of myocardial hypertrophy in renovascular hypertensive rats .%目的:探讨双特异性酪氨酸磷酸化调节激酶1A (Dyrk1A) 经可变剪接因子(ASF)对钙/钙调素依赖蛋白激酶Ⅱδ(CaMKⅡδ)可变剪接的调控在肾血管性高血压大鼠心肌肥厚中的作用.方法:制备两肾一夹肾血管性高血压大鼠模型,给予Dyrk1A抑制剂表没食子儿茶素没食子酸酯(EGCG)和哈尔碱 (harmine) 干预,观察大鼠血压及心肌肥厚程度变化,逆转录-多聚酶链反应法检测CaMKⅡδ可变剪接的改变,免疫印迹法检测大鼠心肌Dyrk1A和ASF蛋白质表达的变化.结果:两肾一夹术后8周,与假手术组相比,手术组大鼠血压显著升高(P<0.05),大鼠左室重、左室重/体重比值及心肌细胞面积均增高(P<0.05),同时该组大鼠心肌中Dyrk1A蛋白表达增加,ASF蛋白表达下降(P<0.05),CaMKⅡδ亚型可变剪接表现为CaMKⅡδA、δB mRNA表达升高,δC mRNA表达降低(P<0.05);与手术组相比,EGCG和哈尔碱组大鼠左室重、左室重/体重比值和心肌细胞面积下降,同时大鼠心肌中Dyrk1A蛋白表达降低,ASF蛋白表达上调,CaMKⅡδ亚型可变剪接逆转(均P<0.05).结论:Dyrk1A可通过ASF调控CaMKⅡδ的可变剪接,从而参与肾血管性高血压大鼠心肌肥厚的发生.