Effects of TET2-targeting miR-27b on oxidized low-density lipoprotein-induced inflammatory responses and apoptosis in endothelial cells
Objective 
To investigate the effects of miR-27b targeting ten-eleven translocation methylcytosine dioxygenase 2 (TET2) on oxidized low-density lipoprotein (ox-LDL) induced inflammatory responses and apoptosis in endothelial cells. 
 
 
Methods 
Double luciferase reporter gene analysis verified the targeting effect of miR-27b on TET2. Human umbilical vein endothelial cells (HUVECs) were induced by ox-LDL in vitro. Eight groups were set up including control group, ox-LDL group, ox-LDL+ anti-miR-con group, ox-LDL+ anti-miR-27b group, ox-LDL+ pcDNA group, ox-LDL+ pcDNA-TET2 group, anti-miR-27b+ si-con group and anti-miR-27b+ si-TET2 group. qRT-PCR was used to detect the expression of miR-27b and TET2 at mRNA level. Cell viability was detected by MTT assay. Cell apoptosis rate was detected by flow cytometry. Western blot was used to detect the expression of TET2, Cyclin D1 and caspase-3 at protein level. 
 
 
Results 
TET2 was the target gene of miR-27b. TET2 expression could be negatively regulated by miR-27b. ox-LDL increased the expression of miR-27b and reduced the expression of TET2 in HUVECs. The secretion of inflammatory factors and apoptosis rates of HUVECs in the control, ox-LDL+ anti-miR-27b, ox-LDL+ pcDNA-TET2 and anti-miR-27b+ si-con groups were significantly lower than those in the ox-LDL, ox-LDL+ anti-miR-con, ox-LDL+ pcDNA and anti-miR-27b+ si-TET2 groups, respectively (P<0.05). 
 
 
Conclusions 
miR-27b promoted ox-LDL-induced inflammatory responses and apoptosis in endothelial cells through down-regulating the expression of TET2. 
 
 
Key words: 
miR-27b; ox-LDL; TET2; HUVEC; Inflammatory response; Apoptosis