脑组织过表达犬尿氨酸酶的转基因小鼠对血压的影响

目的本研究旨在构建脑组织选择性过表达犬尿氨酸酶（Kynu）的转基因小鼠,在整体水平研究KYNU活性增强对血压的影响。方法构建在神经元特异性烯醇酶（NSE）启动子控制下的大鼠Kynu表达载体,采用受精卵原核注射的方法获得脑组织过表达Kynu的转基因小鼠。采用PCR鉴定转基因阳性小鼠;荧光实时定量逆转录PCR（Real Time RT-PCR）、蛋白免疫印迹技术（Western blot）免疫组织化学方法检测转基因的表达;高效液相色谱（HPLC）检测KYNU的活性;鼠尾法测量小鼠血压。结果转基因小鼠与同窝阴性对照小鼠相比,脑干组织中KYNU的表达有显著的差异（P〈0.01）,不同发育阶段转基因小鼠脑干组织Kynu活性与同窝阴性对照小鼠相比,存在显著差异（12周,0.1613±0.0153 vs.0.0019±0.0002 nmol/min/mg,P〈0.01;35周,0.5817±0.1476vs. 0.0038±0.0004 nmol/min/mg,P〈0.05;〉1年,0.1909±0.0115 vs.0.0036±0.0011 nmol/min/ mg,P〈0.01）。但两组小鼠的收缩压没有显著差异（12周,113.6±3.9 Vs.109.3±2.3 mmHg,P〉0.05;35周,114.6±2.5 vs.113.1±4.2 mmHg,P〉0.05;〉1年,121.3±2.6 vs.123.9±3.5 mmH8,P〉0.05）。给予游泳应激刺激后,两组小鼠间的血压也无显著差别。结论脑干组织Kynu的过表达并没有引起日间的和应激的血压值改变,KYNU在血压调节中的作用有待于进一步的研究。

Effect of Selective Brain Overexpression of Kynu reninase on Blood Pressure in Mice

Objective Construction of transgenic mice with selective brain overexpression of Kynureninase（Kynu） to investigate the effect of increased KYNU activity on blood pressure （BP）. Methods We constructed a rat Kynu gene under the control of the neuron-specific enolase （NSE） promoter and derived transgenic mice with an elevated expression of Kynu in the brain. We detected the expression of Kynu and its activity in the brain of transgenic mice and its littermates, as well as measured the BP using tail-cuff method during development. Results We got several lines of mice that have direct transgene-Kynu expression to the brain, The transgenic mouse had significant higher expression of Kynu in the brainstem than its littermates （ P 〈 0.01 ）. and the KYNU activity for transgenic mice in three different period of development were significant higher than its littermates （ 12w, 0. 1613 ± 0. 0153 vs. 0. 0019 ±0. 0002 nmol/min/mg, P 〈0. 0l ;35w, 0.5817 ±0. 1476 vs. 0. 0038 ±0. 0004 nmol/min/mg, t9 〈0.05; 〉 1 year, 0. 1909 _＋0.0115 vs. 0. 0036 ＋0.0011 nmolfmin/mg, P 〈 0.01 ）. The BP levels at different age stage displayed no significant difference between two groups （ 12w, 113.6 ± 3.9 vs. 109.3 ±2.3 mmHg, P 〉 0.05 ; 35w, 114.6 ± 2.5 vs. 113.1 ± 4.2 mmHg, P 〉 0.05 ; 〉 1 year, 121.3 ± 2.6 vs. 123.9 ± 3.5mmHg, P 〉 0. 05） , and there was no significant difference in the stress-stimulated BP levels. Conclusion Overexpression of Kynu in the brainstem of mice leads to no alteration of daily life-BP and stress-stimulating BP, further study was required to test its potential role in BP regulation.