Institute of Cardiovascular & Medical Sciences, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK.
Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
J Hypertens. 2019 May;37(5):985-996. doi: 10.1097/HJH.0000000000001960.
Combined congenic breeding and microarray gene expression profiling previously identified glutathione S-transferase μ-type 1 (Gstm1) as a positional and functional candidate gene for blood pressure (BP) regulation in the stroke-prone spontaneously hypertensive (SHRSP) rat. Renal Gstm1 expression in SHRSP rats is significantly reduced when compared with normotensive Wistar Kyoto (WKY) rats. As Gstm1 plays an important role in the secondary defence against oxidative stress, significantly lower expression levels may be functionally relevant in the development of hypertension. The aim of this study was to investigate the role of Gstm1 in BP regulation and oxidative stress by transgenic overexpression of the Gstm1 gene.
Two independent Gstm1 transgenic SHRSP lines were generated by microinjecting SHRSP embryos with a linear construct controlled by the EF-1α promoter encoding WKY Gstm1 cDNA [SHRSP-Tg(Gstm1)1 and SHRSP-Tg(Gstm1)2].
Transgenic rats exhibit significantly reduced BP and pulse pressure when compared with SHRSP [systolic: SHRSP 205.2 ± 3.7 mmHg vs. SHRSP-Tg(Gstm1)1 175.5 ± 1.6 mmHg and SHRSP-Tg(Gstm1)2 172 ± 3.2 mmHg, P < 0.001; pulse pressure: SHRSP 58.4 ± 0.73 mmHg vs. SHRSP-Tg(Gstm1)1 52.7 ± 0.19 mmHg and SHRSP-Tg(Gstm1)2 40.7 ± 0.53 mmHg, P < 0.001]. Total renal and aortic Gstm1 expression in transgenic animals was significantly increased compared with SHRSP [renal relative quantification (RQ): SHRSP-Tg(Gstm1)1 1.95 vs. SHRSP 1.0, P < 0.01; aorta RQ: SHRSP-Tg(Gstm1)1 2.8 vs. SHRSP 1.0, P < 0.05]. Renal lipid peroxidation (malondialdehyde: protein) and oxidized : reduced glutathione ratio levels were significantly reduced in both transgenic lines when compared with SHRSP [malondialdehyde: SHRSP 0.04 ± 0.009 μmol/l vs. SHRSP-Tg(Gstm1)1 0.024 ± 0.002 μmol/l and SHRSP-Tg(Gstm1)2 0.021 ± 0.002 μmol/l; (oxidized : reduced glutathione ratio): SHRSP 5.19 ± 2.26 μmol/l vs. SHRSP-Tg(Gstm1)1 0.17 ± 0.11 μmol/l and SHRSP-Tg(Gstm1)2 0.47 ± 0.22 μmol/l]. Transgenic SHRSP rats containing the WKY Gstm1 gene demonstrate significantly lower BP, reduced oxidative stress and improved levels of renal Gstm1 expression.
These data support the hypothesis that reduced renal Gstm1 plays a role in the development of hypertension.
先前的研究通过结合同源基因系繁育和微阵列基因表达谱分析，发现谷胱甘肽 S-转移酶 μ 型 1（Gstm1）是自发性高血压脑卒中倾向大鼠（SHRSP）血压调节的一个位置和功能候选基因。与血压正常的 Wistar Kyoto（WKY）大鼠相比，SHRSP 大鼠的肾脏 Gstm1 表达显著降低。由于 Gstm1 在应对氧化应激的二级防御中发挥着重要作用，因此其表达水平的显著降低可能与高血压的发生有关。本研究旨在通过过表达 Gstm1 基因来研究 Gstm1 在血压调节和氧化应激中的作用。
通过将包含 EF-1α 启动子控制的 WKY Gstm1 cDNA 的线性构建物显微注射到 SHRSP 胚胎中，生成了两个独立的 Gstm1 转基因 SHRSP 系[SHRSP-Tg（Gstm1）1 和 SHRSP-Tg（Gstm1）2]。
与 SHRSP 相比，转基因大鼠的血压和脉搏压明显降低[收缩压：SHRSP 205.2 ± 3.7mmHg 与 SHRSP-Tg（Gstm1）1 175.5 ± 1.6mmHg 和 SHRSP-Tg（Gstm1）2 172 ± 3.2mmHg，P < 0.001；脉搏压：SHRSP 58.4 ± 0.73mmHg 与 SHRSP-Tg（Gstm1）1 52.7 ± 0.19mmHg 和 SHRSP-Tg（Gstm1）2 40.7 ± 0.53mmHg，P < 0.001]。与 SHRSP 相比，转基因动物的总肾和主动脉 Gstm1 表达明显增加[肾相对定量（RQ）：SHRSP-Tg（Gstm1）1 1.95 与 SHRSP 1.0，P < 0.01；主动脉 RQ：SHRSP-Tg（Gstm1）1 2.8 与 SHRSP 1.0，P < 0.05]。与 SHRSP 相比，两个转基因系的肾脂质过氧化（丙二醛：蛋白）和氧化还原型谷胱甘肽比值明显降低[丙二醛：SHRSP 0.04 ± 0.009 μmol/l 与 SHRSP-Tg（Gstm1）1 0.024 ± 0.002 μmol/l 和 SHRSP-Tg（Gstm1）2 0.021 ± 0.002 μmol/l；（氧化还原型谷胱甘肽比值）：SHRSP 5.19 ± 2.26 μmol/l 与 SHRSP-Tg（Gstm1）1 0.17 ± 0.11 μmol/l 和 SHRSP-Tg（Gstm1）2 0.47 ± 0.22 μmol/l]。含有 WKY Gstm1 基因的转基因 SHRSP 大鼠表现出明显较低的血压、降低的氧化应激和改善的肾 Gstm1 表达水平。
这些数据支持了这样一种假设，即肾脏 Gstm1 的减少在高血压的发生发展中起作用。
