Vascular endothelial growth factor-A (VEGF-A) expression is reduced in lentivirus (LV)–small hairpin RNA (shRNA)-VEGF-A-transduced and Avastin-treated vessels with decreased CD31 staining. (a, first to third columns) In situ hybridization of mRNA for VEGF-A in the LV-transduced vessels when compared with scrambled-shRNA-VEGF-A (control (C)) vessels, with arrows on cells positive for VEGF-A mRNA expression (brown). By day 3 (D3), there was a reduction of mRNA for VEGF-A being localized to the media and adventitia and by day 7 (D7), it was localized to the media and intima. In contrast, the vessels transduced with C shRNA showed increased mRNA expression of VEGF-A in the adventitia and media by day 3, and in the media and intima by day 7. (b) Pooled data for the in situ transcript levels of VEGF-A in the outflow vein of the LV-transduced vessels that was significantly reduced when compared with C vessels at day 7 (P<0.0001). (c) Upper panel shows the representative real-time PCR (RT-PCR) blots of the VEGF-A with 18S gene for loading with pooled data from the mean gene expression of VEGF-A using RT-PCR analysis. This demonstrates that there is significant reduction in the mean VEGF-A expression in the LV-transduced vessels when compared with C vessels at day 7 (P<0.0001). (d) Representative sections from VEGF-A staining at the venous stenosis of the LV and C-transduced vessels or Avastin-treated or immunoglobulin G (IgG) controls at days 14 and 28. At day 14, there is a significant reduction in the mean VEGF-A staining in the LV-transduced vessels and Avastin-treated vessels when compared with controls (P<0.0001). (e) Representative sections from CD31 staining at the venous stenosis of the LV and C-transduced vessels or Avastin-treated vessels or IgG controls at days 14 and 28. Cells staining brown are positive for CD-31. All are original magnification × 40. Bar=200 μm. *Indicates the lumen. Qualitatively, in the C tissue, when compared with the LV-transduced vessels, there is increased CD31 staining localized to the neointima/media junction by days 14 to 28 in the control tissue. Similar results in the IgG control tissues when compared with Avastin-treated vessels. (b–d) Each bar shows mean±s.e.m. of 4–6 animals per group. Two-way analysis of variance (ANOVA) followed by Student's t-test with post hoc Bonferroni's correction was performed. Significant difference from control value is indicated by #P<0.0001.