Wang Xiuqing, Sun Zhongjie, Cade Robert
Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida 32610, USA.
Kidney Int. 2005 Aug;68(2):680-7. doi: 10.1111/j.1523-1755.2005.00446.x.
Renin has been linked to the pathogenesis of some forms of hypertension, including cold-induced hypertension (CIH). Although several antihypertensive drugs that inhibit angiotensin-converting enzyme (ACE) and angiotensin II (Ang II) type 1 (AT(1)) receptors are available, they are short-lasting and have side effects. Inhibition of renin [the first and rate-limiting step of the renin-angiotensin system (RAS)] would provide an inhibition of the entire RAS. Thus, we developed an antisense approach for specific inhibition of renin based on the genetic design. The objective of this study was to test our hypothesis that adenoviral delivery of renin antisense inhibits renin and attenuates CIH.
Recombinant adenoviruses carrying rat renin antisense (rAdv.RRA) and LacZ reporter gene (rAdv.LacZ) were constructed and used for in vivo gene transfer via intravenous injection. Four groups of rats were used (six rats/group). Blood pressure did not differ among the four groups during the control period at room temperature (25 degrees C). Two groups of rats received rAdv.RRA (2.5 x 10(9) pfu/rat, intravenously), while the other two groups received the same dose of rAdv.LacZ and served as controls. After gene delivery, one rAdv.LacZ-treated and one rAdv.RRA-treated group were exposed to cold (5 degrees C), while the remaining groups were kept at 25 degrees C. Blood pressure was monitored weekly during cold exposure. A 24-hour urine sample was collected during weeks 1, 3, and 5 for measuring urinary aldosterone excretion. At the end of week 5, all animals were killed and blood was collected for measurement of plasma renin activity (PRA), total plasma renin, plasma active renin, and plasma aldosterone. Vascular Ang II contents were measured in all rats.
Blood pressure of the rAdv.LacZ-treated group rose significantly within 2 weeks of exposure to cold and reached 158.2 +/- 6.4 mm Hg by week 5. In contrast, blood pressure (117.1 +/- 5.3 mm Hg) of the cold-exposed group treated with rAdv.RRA did not increase until 5 weeks after exposure to cold. Thus, a single dose of rAdv.RRA prevented CIH for at least 5 weeks. rAdv.RRA abolished the cold-induced increases in PRA, total plasma renin, plasma active renin, vascular Ang II, and plasma and urine aldosterone, indicating effective inhibition of the entire RAS.
rAdv.RRA effectively inhibited the entire RAS and produced prolonged attenuation of CIH. Antisense inhibition of renin may be a novel and ideal approach for long-term control of hypertension.
肾素与某些类型高血压的发病机制有关，包括冷诱导高血压（CIH）。尽管有几种抑制血管紧张素转换酶（ACE）和血管紧张素II（Ang II）1型（AT(1)）受体的抗高血压药物，但它们作用时间短且有副作用。抑制肾素[肾素-血管紧张素系统（RAS）的第一步和限速步骤]将抑制整个RAS。因此，我们基于基因设计开发了一种特异性抑制肾素的反义方法。本研究的目的是检验我们的假设，即腺病毒介导的肾素反义基因递送可抑制肾素并减轻CIH。
构建携带大鼠肾素反义基因（rAdv.RRA）和LacZ报告基因（rAdv.LacZ）的重组腺病毒，并通过静脉注射用于体内基因转移。使用四组大鼠（每组6只）。在室温（25℃）的对照期内，四组大鼠的血压无差异。两组大鼠接受rAdv.RRA（2.5×10(9) pfu/大鼠，静脉注射），而另外两组接受相同剂量的rAdv.LacZ并作为对照。基因递送后，一组rAdv.LacZ处理组和一组rAdv.RRA处理组暴露于寒冷环境（5℃），其余组保持在25℃。在寒冷暴露期间每周监测血压。在第1、3和5周收集24小时尿液样本以测量尿醛固酮排泄。在第5周结束时，处死所有动物并采集血液以测量血浆肾素活性（PRA）、总血浆肾素、血浆活性肾素和血浆醛固酮。测量所有大鼠的血管Ang II含量。
rAdv.LacZ处理组的血压在暴露于寒冷环境2周内显著升高，到第5周时达到158.2±6.4 mmHg。相比之下，用rAdv.RRA处理的寒冷暴露组的血压（117.1±5.3 mmHg）直到暴露于寒冷环境5周后才升高。因此，单剂量的rAdv.RRA至少5周预防了CIH。rAdv.RRA消除了寒冷诱导的PRA、总血浆肾素、血浆活性肾素、血管Ang II以及血浆和尿醛固酮的增加，表明有效抑制了整个RAS。
rAdv.RRA有效抑制了整个RAS并产生了对CIH的长期减轻作用。肾素的反义抑制可能是长期控制高血压的一种新的理想方法。
