PDF(Pubmed)
Abstract：
Increased expression of angiotensin II AT1A receptor (encoded by Agtr1a) and Na+-K+-Cl- cotransporter-1 (NKCC1, encoded by Slc12a2) in the hypothalamic paraventricular nucleus (PVN) contributes to hypertension development. However, little is known about their transcriptional control in the PVN in hypertension. DNA methylation is a critical epigenetic mechanism that regulates gene expression. Here, we determined whether transcriptional activation of Agtr1a and Slc12a2 results from altered DNA methylation in spontaneously hypertensive rats (SHR). Methylated DNA immunoprecipitation and bisulfite sequencing-PCR showed that CpG methylation at Agtr1a and Slc12a2 promoters in the PVN was progressively diminished in SHR compared with normotensive Wistar-Kyoto rats (WKY). Chromatin immunoprecipitation-quantitative PCR revealed that enrichment of DNA methyltransferases (DNMT1 and DNMT3A) and methyl-CpG binding protein 2, a DNA methylation reader protein, at Agtr1a and Slc12a2 promoters in the PVN was profoundly reduced in SHR compared with WKY. By contrast, the abundance of ten-eleven translocation enzymes (TET1-3) at Agtr1a and Slc12a2 promoters in the PVN was much greater in SHR than in WKY. Furthermore, microinjecting of RG108, a selective DNMT inhibitor, into the PVN of WKY increased arterial blood pressure and correspondingly potentiated Agtr1a and Slc12a2 mRNA levels in the PVN. Conversely, microinjection of C35, a specific TET inhibitor, into the PVN of SHR markedly reduced arterial blood pressure, accompanied by a decrease in Agtr1a and Slc12a2 mRNA levels in the PVN. Collectively, our findings suggest that DNA hypomethylation resulting from the DNMT/TET switch at gene promoters in the PVN promotes transcription of Agtr1a and Slc12a2 and hypertension development.
摘要：
下丘脑室旁核（PVN）中血管紧张素IIAT1A受体（由Agtr1a编码）和Na-K-Cl-协同转运蛋白1（NKCC1，由Slc12a2编码）的表达增加有助于高血压的发展。然而,关于高血压PVN中Agtr1a和Slc12a2的转录控制知之甚少。DNA甲基化是调节基因表达的关键表观遗传机制。这里,我们确定了Agtr1a和Slc12a2的转录激活是否由自发性高血压大鼠(SHR)的DNA甲基化改变引起.甲基化DNA免疫沉淀和亚硫酸氢盐测序-PCR显示，与血压正常的Wister-Kyoto大鼠（WKY）相比，SHR中PVN中Agtr1a和Slc12a2启动子处的CpG甲基化逐渐减少。染色质免疫沉淀-qPCR显示DNA甲基转移酶（DNMT1和DNMT3A）和DNA甲基化读数蛋白MeCP2的富集，与WKY相比，SHR中PVN中Agtr1a和Slc12a2启动子的含量大大降低。相比之下,在PVN中，Agtr1a和Slc12a2启动子上的十一种易位酶（TET1-3）的丰度在SHR中比在WKY中高得多。此外，微量注射RG108，一种选择性DNMT抑制剂，进入WKY的PVN会增加动脉血压，并相应地增强PVN中的Agtr1a和Slc12a2mRNA水平。相反，微量注射C35，一种特异性TET抑制剂，SHR的PVN显着降低了动脉血压，伴随着PVN中Agtr1a和Slc12a2mRNA水平的降低。总的来说，我们的研究结果表明,由PVN基因启动子处的DNMT/TET开关引起的DNA低甲基化促进Agtr1a和Slc12a2的转录和高血压的发展.
