Figure 2
Effects of siRNA knock-down of IRS-1 on BAEC angiogenesis and cell signalling:
BAEC were subjected to siRNA knock-down of IRS-1as described in the Materials and Methods section of this article. After 48 h treatment, approximately an 85% reduction in IRS-1 gene expression was noted (A). In contrast, NC siRNA had no effect on IRS-1 gene expression. Knock-down was tested for each experiment and found to be similar and the figure shows a representative example. (B) a reduction (50%) in mCRP-induced tube-like-structure formation was seen in siRNA-treated cells. The bar chart shows significant reduction in tube formation in the presence of IRS-1 siRNA (**p < 0.01; *p < 0.05). Pre-incubation with our characterised antibody specific for mCRP (4 h; 1 μg/ml) was able to inhibit both p-ERK1/2 and p-IRS-1 expression in BAEC (C) and also, significantly, tube-like-structure formation (D; *p < 0.05). Note nCRP was not tested in these assays as we have previously shown that it has no pro-angiogenic activity8 These experiments were carried out three times and where statistical analysis was performed, results represent the mean ± S.D of these experiments.
