β_1受体反义基因治疗对两肾一夹高血压大鼠心肌Bcl-2的影响

The Inhibitive Effect of β_1 Receptor mRNA Antisense on Bcl-2 expression in Myocardium in 2-Kidney,1-Clip Hypertensive Rats

目的比较两肾一夹(2K1C)肾性高血压大鼠心肌Bcl-2的表达,探讨阳离子脂质体混合物介导的β1受体反义基因治疗对肾性高血压大鼠血压及心肌Bcl-2表达的影响。方法将18只雄性SD大鼠随机分成3组,每组6只。其中2组12只用来制作两肾一夹高血压模型,作为两肾一夹组;6只作为假手术组,仅分离左肾动脉而不套银夹。两肾一夹模型又分为反义寡核苷酸(β1-AS-ODN)组(反义组)和反向寡核苷酸(Inverted ODN,β1-IN-ODN)组(反向组)。阳离子脂质体1,2-bis(oleoyloxy)-3-(trimethylammo-nio)propane/cholesterol(DOTAP)和辅助脂质体l-a-dioleoyl hosphatidylethanolamine(DOPE)以1∶1的摩尔比混合。阳离子脂质体混合物(DOTAP/DOPE)与β1-AS-ODN、β1-IN-ODN混合的摩尔比率均为2.0,经鼠尾静脉注射。监测血压,8周后测定血流动力学指标,免疫组织化学方法检测3组大鼠心肌Bcl-2的表达。结果反义寡核苷酸治疗可使血压显著下降,单剂治疗可维持血压降低27 d,血压最大下降39mm Hg。反义组的心脏湿重/体重(HW/BW)也显著低于对照组(P<0.01)。两肾一夹组心肌Bcl-2表达明显高于假手术组,β1-IN-ODN组心肌Bcl-2表达明显高于β1-AS-ODN组。结论以β1受体为靶基因的反义基因对肾性高血压有效,单剂治疗降压持续时间长,而且在抑制血压和左室肥厚的同时也明显抑制心肌Bcl-2的表达,提示β1-AS-ODN对心肌Bcl-2的抑制在抗高血压靶器官损伤过程中起一定的作用。

Objective To study the inhibitive effect of β1 receptor mRNA antisense on activation of Bcl-2 in myocardium in 2-kidney, 1-Clip （2K1C）hypertensive rats. Methods Eighteen SD rats were divided randomly into 3 groups： two 2K1C hypertension model（n= 12）and one sham operation group. The two 2K1C models were subdivided into β1 receptor antisense oligodeoxy nucleotides（β1-AS-ODN） group and inverted ODN （ β1-IN-ODN ） group, 1, 2-bis （ oleoyloxy）-3-（ trimethylammonio ） propane/cholesterol （DOTAP） and 1-a-dioleoyl posphatidylethanolamine （DOPE） were mixed. Ratio of the liposome/ODN and β1-AS-ODN, β1-IN-ODN was 2 ： 1. This mixture was injected into the veins of rats. The hemodynamic studies of the 2K1C were performed after eight weeks. Results The single dose of β1-AS-ODN decreased blood pressure by up to 39 mm Hg for 27 days. Compared with that of the sham group, left ventricular systolic pressure（LVSP） and left ventricular end diastolic pressure （LVEDP） were increased （P〈 0.01, P〈0.01 ; respectively） and dp/dt were significantly decreased （ P〈0.01, P〈0.01 ; respectively）. Bcl-2 expression in myocardium in 2K1C rats was higher than that of sham group. The lower expression of Bcl-2 was found in β1-AS-ODN group in relative to β1-IN-ODN group. Conclusion β1 receptor antisense oligodeoxynucleotides was effective reduction of high BP in renal hypertension rats. Single dose of β1-AS-ODN maintained anti-hypertension effect for a relative long time.