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微小RNA在自发性高血压大鼠主动脉的差异表达

许婵婵, 韩卫青, 肖冰, 李宁宁, 朱鼎良, 高平进

上海交通大学附属瑞金医院,上海市高血压研究所,上海市血管生物学重点实验室,医学基因组学国家重点实验室,中科院上海生命科学研究院健康科学研究所.上海 200025

摘要

微小RNAs(microRNAs,miRNAs)是一类基因组编码、非蛋白质编码的小RNA,在转录后水平负性调节靶基因表达。该研究探讨miRNAs在自发性高血压大鼠(spontaneously hypertensive rats,SHR)主动脉的表达特征及其与高血压的关系。取4、8、16和24周龄雄性SHR大鼠及同龄正常血压对照(Wistar--Kyoto,WKY)大鼠。MiRanda、TargetScan和PicTar用于候选miRNAs及靶基因预测分析。通过实时定量RT--PCR检测大鼠主动脉miR--1、miR--133a、miR--155及miR--208的表达,并进一步通过实时定量RT--PCR检测呈差异表达的miR--155和miR--208的预测靶基因mRNA表达。结果显示,SHR大鼠主动脉miR--155表达在4、8、24周时与同龄WKY大鼠无显著差异,但在16周时明显低于同龄WKY大鼠({sl P}<0.05),且大鼠主动脉miR--155表达量与血压呈负相关({sl r}=--0.525,{sl P}<0.05)。MiR--208表达在4周龄时最高,随年龄增长明显下降({sl P}<0.05),其表达水平与血压和年龄呈负相关({sl r}=--0.400,{sl P}<0.05;{sl r}=--0.684,{sl P}<0.0001),但在SHR和WKY大鼠之间无显著差异。miR--1和miR--133a在各年龄组SHR和WKY大鼠间未呈现差异表达。MiR--155和miR--208表达与相应预测靶基因mRNA表达无显著负相关性。以上结果表明,miR--155表达在成年SHR大鼠主动脉明显低于WKY,并与血压呈负相关,提示miR--155可能参与高血压的发生发展,主动脉miR--155表达异常可能是SHR大鼠血压升高的原因之一。大鼠主动脉miR--208表达在幼年时最高,随年龄增长而明显下降,提示其可能与血管发育有关。

关键词： 微小RNAs; 自发性高血压大鼠; 主动脉; RT-PCR

Differential expression of microRNAs in the aorta of spontaneously hypertensive rats

Xu Chanchan, Han Weiqing, Xiao Bing, Li Ningning, Zhu Dingliang, Gao Pingjin

Ruijin Hospital,Shanghai Institute of Hypertension,Shanghai Jiaotong University Medical School,Shanghai Institute for Vascular Biological Sciences,Institute of Health Sciences,Chinese Academy of Sciences and State Key Laboratory of Medical Genomics.Shanghai 200025

Abstract

MicroRNAs (miRNAs) are genomically encoded non-protein-encoding small RNAs, which negatively regulate target gene expression at post-transcriptional level. The present study aimed to investigate whether disorders of miRNAs system were involved in the pathogenesis of hypertension in spontaneously hypertensive rats (SHR). MiRanda, Target Scan and PicTar were utilized for predictive analysis of miRNAs and target genes. MiR-1, miR-133a, miR-155 and miR-208 were selected as the candidate miRNAs potentially related to blood pressure. The expression levels of miR-1, miR-133a, miR-155 and miR-208 in the aorta of 4-, 8-, 16- and 24-week-old SHR and age-matched Wistar-Kyoto (WKY) rats were detected by real-time RT-PCR. The mRNA levels of angiotensin II receptor type 1 (AGTR1a), angiotensin II receptor associated protein (AGTRAP), divalent metal transporter 1 (DMT1), low-density lipoprotein-related protein 1B (LRP1B), fibroblast growth factor-7 (FGF-7), protocadherin 9 precursor (PCDH9), chloride channel protein 5 (CLCN-5), small conductance calcium activated potassium channel protein 3 (KCNN3) and thyroid hormone receptor associated protein 1 (THRAP1), which were predicted to be target genes of differentially expressed miRNAs, were further detected by real-time RT-PCR. The results obtained showed that the expression levels of miR-1, miR-155 and miR-208 in the aortawere significantly different from those in the heart of WKY rats. The miR-155 level was significantly lower in aorta of 16-week-old SHR than that of age-matched WKY rats (P<0.05), but there was no difference between SHR and WKY rats in other age groups. In addition, miR-155 level was negatively correlated to blood pressure (r= -0.525, P<0.05). Both in WKY rats and SHR, miR-208 was most abundantly expressed in 4-week-old rats, but declined significantly in 8-, 16- and 24-week-old rats (P<0.05). No difference in miR-208 levels was observed between age-matched SHR and WKY rats. Moreover, miR-208 expression in aorta was negatively correlated with blood pressure (r= -0.400, P<0.05) and age (r= -0.684, P<0.0001). Neither miR-1 nor miR-133a was differentially expressed in SHR and WKY rats in different age groups. The mRNA levels of predicted target genes were not correlated to miR-155 or miR-208 levels. These results indicate that miR-155 is less expressed in the aorta of adult SHR compared with that of WKY rats and is negatively correlated with blood pressure, suggesting it is possibly involved in the development and pathologic progress of hypertension. The miR-208 expression in rat aorta declines with aging and it may play a role in the blood vessel development.

Key words: microRNAs;spontaneously hypertensive eats;aorta;RT-PCR

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引用本文：

许婵婵, 韩卫青, 肖冰, 李宁宁, 朱鼎良, 高平进. 微小RNA在自发性高血压大鼠主动脉的差异表达[J]. 生理学报 2008; 60 (4): 553-560.

Xu Chanchan, Han Weiqing, Xiao Bing, Li Ningning, Zhu Dingliang, Gao Pingjin. Differential expression of microRNAs in the aorta of spontaneously hypertensive rats. Acta Physiol Sin 2008; 60 (4): 553-560 (in Chinese with English abstract).