Related Experiment Video
Updated: Jul 2, 2026
Evaluation of Vascular Control Mechanisms Utilizing Video Microscopy of Isolated Resistance Arteries of Rats
Published on: December 5, 2017
[Differential expression of microRNAs in the aorta of spontaneously hypertensive rats]
Chan-Chan Xu1, Wei-Qing Han, Bing Xiao
1Ruijin Hospital, Shanghai Institute of Hypertension, Shanghai Jiaotong University Medical School, Chinese Academy of Sciences and State Key Laboratory of Medical Genomics, Shanghai 200025, China.
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 aorta were 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.
Insights
MicroRNA-155 (miR-155) is less expressed in the aorta of hypertensive rats and correlates with blood pressure, suggesting its role in hypertension development. MicroRNA-208 (miR-208) expression declines with age in rat aortas.
Area of Science:
- Cardiovascular Biology
- Molecular Genetics
- Epigenetics
Background:
- MicroRNAs (miRNAs) are small non-coding RNAs regulating gene expression post-transcriptionally.
- Hypertension pathogenesis may involve dysregulation of the miRNA system.
- This study investigates miRNA involvement in hypertension using spontaneously hypertensive rats (SHR).
Purpose of the Study:
- To investigate the role of specific miRNAs in the pathogenesis of hypertension.
- To analyze the expression levels of candidate miRNAs (miR-1, miR-133a, miR-155, miR-208) in the aorta of SHR and WKY rats.
- To correlate miRNA expression with blood pressure and age.
Main Methods:
- Bioinformatic prediction of miRNA targets using Miranda, Target Scan, and PicTar.
- Real-time RT-PCR to quantify miRNA and mRNA expression in rat aortas.
- Correlation analysis between miRNA levels, blood pressure, and age.
Main Results:
- miR-155 expression was significantly lower in the aorta of adult SHR compared to WKY rats and negatively correlated with blood pressure.
- miR-208 expression was abundant in young rats and declined significantly with age in both SHR and WKY rats, negatively correlating with blood pressure and age.
- No significant differential expression was found for miR-1 or miR-133a between SHR and WKY rats.
Conclusions:
- miR-155 may be involved in the development and progression of hypertension due to its reduced expression in SHR aortas.
- miR-208 expression decreases with aging in rat aortas and may play a role in vascular development.
- Predicted target gene mRNA levels did not correlate with miR-155 or miR-208 levels in this study.
More Related Videos
06:08Ultrasound Imaging of the Thoracic and Abdominal Aorta in Mice to Determine Aneurysm Dimensions
Published on: March 8, 2019
08:08Two-photon Imaging of Intracellular Ca2+ Handling and Nitric Oxide Production in Endothelial and Smooth Muscle Cells of an Isolated Rat Aorta
Published on: June 10, 2015