RNA阵列技术检测自发性高血压大鼠 G蛋白-肌醇磷脂途径基因表达改变

目的探讨G蛋白-肌醇磷脂途径基因表达改变在原发性高血压病理机制中的作用.方法分别提取2、4、6、8、10、12周龄各组雄性自发性高血压大鼠(SHR,38只)和正常血压大鼠(WKY,38只)心室肌、血管平滑肌、肝脏和肾脏组织的总RNA,共294个样品,利用高通量RNA阵列技术检测组织中G蛋白G11、Gq和PLCβ在不同周龄SHR中mRNA的表达谱改变.结果 (1)SHR在6、8、10、12周龄血压158 mm Hg±8 mm Hg(1 mm Hg=0.133 kPa), 174 mm Hg±4 mm Hg,198 mm Hg±13 mm Hg,217 mm Hg±9 mm Hg],显著高于同周龄WKY组(109 mm Hg±6 mm Hg,128 mm Hg±5 mm Hg,142 mm Hg±4 mm Hg,141 mm Hg±5 mm Hg,P均<0.01),10、12周龄心室肌重量/体重比显著增加(P均<0.01);(2)SHR在4、6、8、10、12周龄,心肌组织G11的表达(1.42±0.35、1.87±0.40、1.96±0.24、2.09±0.38、2.34±0.45)显著性高于WKY(1.05±0.18、1.25±0.37、1.26±0.35、1.45±0.30、1.51±0.42,P<0.05或P<0.01),G11在血管平滑肌和肾脏组织的表达有类似的结果;(3)SHR在4、6、8、10、12周龄心肌组织Gq的表达(1.12±0.21、1.30±0.26、1.45±0.35、1.77±0.42、2.05±0.46)显著高于WKY(0.88±0.09、0.96±0.10、1.03±0.10、1.21±0.38、1.29±0.39,P<0.05或P<0.01),血管平滑肌和肾脏组织亦有相似的结果;(4)PLCβ基因表达在心肌组织和肾脏中在4、6、8、10、12周龄出现显著性升高(P<0.05或P<0.01),而在血管平滑肌组织中未见PLCβ的明显差异表达;(5)肝脏组织中未见上述基因的明显差异表达.结论 G蛋白-肌醇磷脂途径相关基因mRNA表达增加是原发性高血压的发生和发展过程中重要的分子生物学机制.

Alterations of expression of G protein-inositol phosphates pathway-related genes in essential hypertension: experiment with spontaneously hypertensive rats

OBJECTIVE: To investigate the changes of G protein-inositol phosphates pathway-related genes and evaluate the role of such changes in the pathogenesis of essential hypertension. METHODS: The pressures of the caudal arteries and body weights of 30 spontaneous hypertensive rats (SHRs), 7 two-week-old, 7 4-week-old, 6 six-week-old, 6 eight-week-old, 6 ten-week-old, and 6 twelve-week-old, and 38 normotensive Wistar-Kyoto (WKY) rats, 6 two-week-old, 6 four-week-old, 6 six-week-old, 6 six-week-old, 6 eight-week-old, 7 ten-week-old, and 7 twelve-week-old, were measured. Then the rats were killed and their hearts, aortas, livers, and kidneys were taken out. 294 specimens of total RNA were obtained from the tissues of ventricle of heart, aortic smooth muscle, liver and kidney. RNA array was used to determine the mRNA levels of G proteins G11 and Gq, and phospholipase C-beta (PLCbeta). RESULTS: The systolic blood pressures of the 6, 8, 10, and 12-week-old SHRs were 158 mm Hg +/- 8 mm Hg, 174 mm Hg +/- 4 mm Hg, 198 mm Hg +/- 13 mm Hg, and 217 mm Hg +/- 9 mm Hg respectively, all significantly higher than those of the age-matched WKY rats (109 mm Hg +/- 6 mm Hg, 128 mm Hg +/- 5 mm Hg,142 mm Hg +/- 4 mm Hg, and 141 mm Hg +/- 5 mm Hg respectively, all P <0.01). The cardiosomatic ratios of the 10- and 12-week-old SHRs were both significantly higher than those of the age-matched WKY rats (both P < 0.01). The G11 mRNA levels in the heart tissue of the 4, 6, 8, 10, and 12-week-old SHRs were 1.42 +/- 0.35, 1.87 +/- 0.40, 1.96 +/- 0.24, 2.09 +/- 0.38, and 2.34 +/- 0.45, all significantly higher than those of the age-matched WKY rats (1.05 +/- 0.18, 1.25 +/- 0.37, 1.26 +/- 0.35, 1.45 +/- 0.30, and 1.51 +/- 0.42 respectively, P < 0.05 or P < 0.01). The Gq mRNA levels of the 4, 6, 8, 10, and 12-week-old SHRs were 1.12 +/- 0.21, 1.30 +/- 0.26, 1.45 +/- 0.35, 1.77 +/- 0.42, and 2.05 +/- 0.46, respectively, all significantly higher than those of the age-matched WKY rats (0.88 +/- 0.09, 0.96 +/- 0.10, 1.03 +/- 0.10, 1.21 +/- 0.38, and 1.29 +/- 0.39 respectively, P < 0.05 or P < 0.01). Similar results were found in the G11 and Gq mRNA levels of the aorta and kidney tissues. The levels of PLCbeta expression in the heart and kidney tissues of the 4, 6, 6, 8, 10, and 12-week-old SHRs were all significantly increased (P <0.05 or P <0.01). Galpha, Gq, and PLCbeta were not significantly expressed in the liver. PLCbeta was hardly found in the aorta. CONCLUSION: Increase of the expression of G protein-inositol phosphates pathway-related genes is an important molecular biological mechanism in the pathogenesis and development of essential hypertension.