三种突变GRK4转基因小鼠的血压动态分析

目的建立GRK4γ野生型和三种GRK4γ基因突变的转基因小鼠,并对其血压进行动态分析,建立高血压模型。方法把人GRK4γ野生型、GRK4γR 65L、GRK4γA142V和GRK4γA486V三个突变基因分别插入鸡β-肌动蛋白启动子下游,构建转基因表达载体,显微注射法建立C57BL/6J GRK4野生型和突变的转基因小鼠,PCR鉴定转基因小鼠基因型。采用Western Blot鉴定GRK4在心脏、肾脏和肾上腺中的表达筛选高表达转基因品系。用无创血压测量仪分析转基因小鼠动态血压。结果建立了在心脏、肾脏和肾上腺均高表达GRK4基因的转基因小鼠。转基因表达人GRK4γ野生型和GRK4γR 65L突变的小鼠血压正常,转基因表达人GRK4γA142V突变的小鼠在正常的钠盐摄入情况下即可发生高血压,而转基因表达人GRK4γA486V突变的小鼠只有在增加钠盐摄入情况下才发生高血压。结论 GRK4γA142V转基因小鼠可作为自发性高血压动物模型,GRK4γA486V转基因小鼠可作为盐敏感性高血压动物模型。

Dynamic analysis of blood pressure in three GRK4 variant transgenic mice

Objective G-protein-coupled receptor kinase 4 （GRK4） negatively regulates sodium balance in the proximal tubule of kidney by desensitizing the dopamine-1-receptor. It is reported that mutation of GRK4 gene has been linked to impaired natriuresis and hypertension. In this aritcle, we established GRK4γ wild-type and three GRK4γ variant transgenic mice and analyzeed dynamic changes of blood pressure using this transgenic mouse model. Methods The transgenic vector was constructed by inserting the human GRK4γ wild-type, GRK4γ^R65L , GRK4γ^A142 and GRK4γA486V gene into the downsteam of chicken β-actin promoter, respectively. The transgenie mice were created by microinjection. The genotype of transgenic line was identified by PCR and the expression level of target gene was determined by Western blot. Dynamic changes of blood pressure was measured with a noninvasive blood pressure meter. Results Each line of human wild- type, GRK4γ^R65L, GRK4γA142v and GRK4γA456V C57BL/6J transgenic mice with high levels of GRK4 expression in the heart, kidney and adrenal gland tissues was established. Mice overexpressing the human GRK4γ wild-type and GRK4γR65L gene were normotensive, whereas mice overexpressing the human GRK4γA142V were hypertensive even on a normal NaC1 intake. In contrast, human GRK4γA484V transgenic mice became hypertensive only after an increase of sodium intake. Conclusions GRK4γA142V transgenic mice may serve as an animal model for spontaneous hypertension, whereas GRK4γA486V transgenic mice may serve as an animal model for salt-sensitive hypertension.