Department of Pharmacology, Kyungpook National University School of Medicine, Daegu, Korea.
J Renin Angiotensin Aldosterone Syst. 2012 Mar;13(1):11-8. doi: 10.1177/1470320311415738. Epub 2011 Jul 29.
The (pro)renin receptor [(P)RR] non-proteolytically, through conformational change, activates prorenin which can convert angiotensinogen to angiotensin I in addition to the classic conversion of angiotensinogen to angiotensin I by circulating renin. Since renal (P)RR is upregulated in hypertension and implicated in the pathogenesis of malignant hypertension, we hypothesized that (pro)renin receptor promoter is enriched with activating histone codes in the kidney of spontaneously hypertensive rats (SHR).
The mRNA and protein expression levels were measured by real-time polymerase chain reaction (PCR) and western blot, respectively. The DNA methylation status of (P)RR promoter region was analyzed by bisulfite sequencing. The histone modifications were determined by chromatin immunoprecipitation followed by real-time PCR.
The (P)RR mRNA expression in the kidney was about six times greater in SHR than in Wistar-Kyoto (WKY) rats. The (P)RR promoter was little methylated in the kidneys of both WKY and SHR. Acetylated histone H3 (H3Ac) and di-methylated histone H3 at lysine 4 (H3K4me2), activating histone codes, were about 25 and three times higher in SHR than in WKY, respectively. On the other hand, di-methylated histone H3 at lysine 9 (H3K9me2), a suppressive histone code, was 50 times lower in SHR than in WKY.
These results suggest that the (P)RR promoter is enriched with activating histone codes in the kidneys of SHR.
（前）肾素受体[(P)RR] 通过构象变化非蛋白水解地激活原肾素，原肾素除了可以通过循环肾素来将血管紧张素原转化为血管紧张素 I 外，还可以将血管紧张素原转化为血管紧张素 I。由于高血压患者的肾脏（P)RR 上调，并与恶性高血压的发病机制有关，我们假设自发性高血压大鼠（SHR）肾脏中（前）肾素受体启动子富含激活组蛋白密码。
通过实时聚合酶链反应（PCR）和 Western blot 分别测量 mRNA 和蛋白表达水平。通过亚硫酸氢盐测序分析（P)RR 启动子区域的 DNA 甲基化状态。通过染色质免疫沉淀 followed by real-time PCR 确定组蛋白修饰。
与 Wistar-Kyoto（WKY）大鼠相比，SHR 肾脏中的（P)RR mRNA 表达高约 6 倍。WKY 和 SHR 肾脏中的（P)RR 启动子几乎没有甲基化。乙酰化组蛋白 H3（H3Ac）和组蛋白 H3 赖氨酸 4 二甲基化（H3K4me2），激活组蛋白密码，在 SHR 中分别比在 WKY 中高约 25 倍和 3 倍。另一方面，组蛋白 H3 赖氨酸 9 二甲基化（H3K9me2），一种抑制性组蛋白密码，在 SHR 中比在 WKY 中低 50 倍。
这些结果表明，在 SHR 的肾脏中，（P)RR 启动子富含激活组蛋白密码。
