Cardiac Hypertrophy is Positively Regulated by MicroRNA‑24 in Rats / 中华医学杂志(英文版)
Chinese Medical Journal
; (24): 1333-1341, 2018.
Article
in En
| WPRIM
| ID: wpr-688122
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WPRO
ABSTRACT
<p><b>Background</b>MicroRNA-24 (miR-24) plays an important role in heart failure by reducing the efficiency of myocardial excitation-contraction coupling. Prolonged cardiac hypertrophy may lead to heart failure, but little is known about the role of miR-24 in cardiac hypertrophy. This study aimed to preliminarily investigate the function of miR-24 and its mechanisms in cardiac hypertrophy.</p><p><b>Methods</b>Twelve Sprague-Dawley rats with a body weight of 50 ± 5 g were recruited and randomly divided into two groups: a transverse aortic constriction (TAC) group and a sham surgery group. Hypertrophy index was measured and calculated by echocardiography and hematoxylin and eosin staining. TargetScans algorithm-based prediction was used to search for the targets of miR-24, which was subsequently confirmed by a real-time polymerase chain reaction and luciferase assay. Immunofluorescence labeling was used to measure the cell surface area, and H-leucine incorporation was used to detect the synthesis of total protein in neonatal rat cardiac myocytes (NRCMs) with the overexpression of miR-24. In addition, flow cytometry was performed to observe the alteration in the cell cycle. Statistical analysis was carried out with GraphPad Prism v5.0 and SPSS 19.0. A two-sided P < 0.05 was considered as the threshold for significance.</p><p><b>Results</b>The expression of miR-24 was abnormally increased in TAC rat cardiac tissue (t = -2.938, P < 0.05). TargetScans algorithm-based prediction demonstrated that CDKN1B (p27, Kip1), a cell cycle regulator, was a putative target of miR-24, and was confirmed by luciferase assay. The expression of p27 was decreased in TAC rat cardiac tissue (t = 2.896, P < 0.05). The overexpression of miR-24 in NRCMs led to the decreased expression of p27 (t = 4.400, P < 0.01), and decreased G0/G1 arrest in cell cycle and cardiomyocyte hypertrophy.</p><p><b>Conclusion</b>MiR-24 promotes cardiac hypertrophy partly by affecting the cell cycle through down-regulation of p27 expression.</p>
Key words
Full text:
1
Index:
WPRIM
Main subject:
Pathology
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Physiology
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Cell Cycle
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Rats, Sprague-Dawley
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Cardiomegaly
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Cell Biology
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Myocytes, Cardiac
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MicroRNAs
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Cyclin-Dependent Kinase Inhibitor p27
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Genetics
Limits:
Animals
Language:
En
Journal:
Chinese Medical Journal
Year:
2018
Type:
Article