Figure 3: ERK5 siRNA enhanced tube formation in ECs under normal and high glucose conditions. (a–d): Representative phase-contrast photographs of in vitro angiogenesis assay showing tube formation in ECs. Such tube formations were pronounced following ERK5 siRNA transfection ((c) and (d)), compared with control siRNA transfection ((a) and (b)), both in 5 mmol/l (LG) or 25 mmol/l (HG) glucose. Original magnification at 100x. (e): Quantification of tube formation by counting branch points of tube-like structures confirmed stimulatory effect of ERK5 siRNA on tube formation. [Data are expressed as number of branch points per 100× field, * significantly different from control siRNA in LG, : significant difference from control siRNA in HG, n=3/group].