Figure 6. miR-92a regulates endothelial function in vitro and ex vivo.

(A) HUVECs were transfected with control RNA or anti-92a. After 48 hr, the NO bioavailability was detected by fluorometric assay and expressed as nmol/10⁶ cells. In (B), HUVECs were transfected with pre-92a and infected with Ad-KLF2-3’UTR or Ad-null for 48 hr. The level of KLF2 and eNOS mRNA was assessed by qRT-PCR and NO bioavailability was measured. (C) pre-92a or control RNA was administered to the carotid arteries of C57BL6 mice by pluronic gel F-127. Five days later, the arteries were isolated. The expression levels of miR-92a, KLF2 and eNOS in the isolated vessels (n=6) were assessed by qRT-PCR. miR-92a level was normalized to that of U6 RNA, whereas KLF2 and eNOS levels were normalized to that of GAPDH. The data represent mean±SD. (D) The flow-induced vasodilation ex vivo was measured by use of the SoftEdge Acquisiton Subsystem in the presence or absence of L-NAME (1 µM). The dilation ability is defined as the percentage of the diameter change of the flow-induced dilation compared to the diameter change of the PE-induced constriction. The bars represent mean±SEM. p<0.05 between the 2 groups being compared by Student t test (A,C) or two-way ANOVA followed by the Bonferroni posthoc test (B,D).