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Overexpression of microRNA-1 causes atrioventricular block in rodents.
|Title||Overexpression of microRNA-1 causes atrioventricular block in rodents.|
|Publication Type||Journal Article|
|Year of Publication||2013|
|Authors||Zhang Y, Sun L, Zhang Y, Liang H, Li X, Cai R, Wang L, Du W, Zhang R, Li J, Wang Z, Ma N, Wang X, Du Z, Yang B, Gao X, Shan H|
|Journal||International journal of biological sciences|
The present study was designed to investigate whether microRNAs (miRNAs) are involved in atrioventricular block (AVB) in the setting of myocardial ischemia (MI). A cardiac-specific miR-1 transgenic (Tg) mouse model was successfully established for the first time in this study using microinjection. miR-1 level was measured by real-time qRT-PCR. Whole-cell patch clamp was employed to record L-type calcium current (I Ca,L) and inward rectifier K(+) current (I K1). Expression of connexin 43 (Cx43) protein was determined by western blot analysis. Alternations of [Ca(2+)]i was detected by laser scanning confocal microscopy in ventricular myocytes. The incidence of AVB was higher in miR-1 Tg mice than that in wild-type (WT) mice. The normalized peak current amplitude of I Ca,L was lower in ventricular myocytes from miR-1 Tg mice as compared with WT mice. Similarly, the current density of I K1 was decreased in miR-1 Tg mice than that in WT mice. Compared with WT mice, miR-1 Tg mice exhibited a significant decrease of the systolic [Ca(2+)]i in ventricular myocytes but a prominent increase of the resting [Ca(2+)]i. Moreover, Cx43 protein was downregulated in miR-1 Tg mice compared to that in WT mice. Administration of LNA-modified antimiR-1 reversed all the above changes. miR-1 overexpression may contribute to the increased susceptibility of the heart to AVB, which provides us novel insights into the molecular mechanisms underlying ischemic cardiac arrhythmias.
|Alternate Journal||Int. J. Biol. Sci.|