(A) ECs were transfected with either a let-7b-5p mimic (right) or a let-7b-5p inhibitor (left). The random sequence anti-miR miRNA inhibitor (scramble) was used as control. Efficiency of let-7b-5p transfection was assessed by qPCR using U6 as a normalizer. (B) Matrigel assay photomicrograph (the scale bar represents 100 μm) and quantification (total length of tube-like structures), 5× magnification. (C and D) Caspase activity (C) and BrdU incorporation (D) of ECs transfected as previously described. (E) Relative expression of the let-7b-5p direct target gene TGFBR1 (measured by PCR using ubiquitin C [UBC] as normalizer). All values are mean + SEM. *p ≤ 0.05, **p ≤ 0.01, and ***p ≤ 0.001 versus the respective scramble control (unpaired Student’s t test); n = 4.