Aims: This study was aimed to determine whether microRNA1 (miR1) plays a role in the activation of myosin light chain kinase (MLCK) mediated by oxLDL in human umbilical vein endothelial cells (HUVECs).
Main methods: HUVECs were treated with oxLDL along with a control miR or miR1 mimic. MiR1 expression was assayed by miRNA plate assay kit and mirVana™ miRNA isolation kit. The MLCK protein, transcript, and kinase activity were measured by Western blot, real-time-polymerase chain reaction and γ-(32)P-ATP phosphate incorporation, respectively. In addition, phosphorylation of MLC, ERK and p38 was analyzed by Western blot.
Key findings: The results showed that upon treatment with oxLDL, miR1 expression was decreased, whereas MLCK expression was increased, in a time- and dose-dependent manner. Consistent with this, miR1 mimic prevented MLCK expression and activation and attenuated the phosphorylation of MLC and ERK/p38 in oxLDL-treated HUVECs. Furthermore, we showed that miR1 was able to bind a site located at the 3'un-translational region of MLCK mRNA and inhibited its expression.
Significance: Taken together, this study demonstrated that the effect of miR1 on hyperlipidemia is mediated through down-regulation of MLCK and the ERK/p38 MAPK pathway.
Keywords: HUVECs; Hyperlipidemia; MicroRNA1; Myosin light chain kinase.
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