Objective Psychological stress has become an important factor in the development of cardiac disorders. MicroRNAs (miRNA) have been implicated in regulation of cardiovascular diseases. Therefore, we investigated whether miRNAs are involved in the psychological stress-induced cardiac disorders.
Methods Stress rat models were established by complex stimulation at different times during the daytime for 2 weeks. Body weight, blood pressure and ECG were measured) every 3 days during processing stress. Adrenocorticotrophic hormone (ACTH) was measured by using ELISA. Cardiac changes were detected by HE staining and electronic microscopy. MicroRNA microarray was used for analysing the differential expression of miRNAs.
Results After psychological stress, rats displayed change in behaviour. Body weight increased slowly and systolic blood pressure increased significantly in stress group from the 6th day to the 15th day. The ECG of all rats was normal before experiment. 2 weeks after stimulation the ECG record of different individuals in stress group showed different arrhythmia, including sinus tachycardia, atrial premature contraction, ventricular arrhythmia, and ST-T changes. Hypothalamic-pituitary-adrenal activity increased in stress group compared to control group by detecting ACTH. And the ultrastructure and histology showed injury changes in stress group. Compared to the control group, there were 55 different miRNAs in stress model including upregulation of 20 and downregulation of left, among which miRNA-141, miRNA−382, miRNA-219-5p and miRNA-296 up-regulate, miRNA-135a and miRNA-466b are significant down-regulate.
Conclusions Complex stimulation can induce psychological stress, which can cause cardiac injury. MiRNAs change in stress rat models, including upregulation of miR-141, miR−382, miR-219-5p and miR-296, and significant downregulation of miR-135a and miR-466b, which may play important roles in psychological stress-induced cardiac disorders. (Supported by research grant NSFC 30940041).
- psychological stress-induced cardiac disorders