Angiogenin Essential for Endothelial Cell Proliferation and Angiogenesis

Researchers at Harvard University's School of Medicine have made a groundbreaking discovery regarding angiogenin's role in angiogenesis. According to the study, angiogenin is a crucial protein that promotes endothelial cell proliferation and angiogenesis by stimulating rRNA transcription, a rate-limiting step in ribosome biogenesis, protein translation, and cell growth. The study found that angiogenin is required for cell proliferation induced by various angiogenic proteins, including aFGF, bFGF, EGF, and VEGF. Moreover, downregulation of angiogenin in endothelial cells using siRNA and antisense resulted in a significant decrease in rRNA transcription, ribosome biogenesis, and cell proliferation induced by these angiogenic factors.

Key Takeaways:

• Angiogenin is essential for endothelial cell proliferation and angiogenesis by stimulating rRNA transcription.
• Angiogenin is required for cell proliferation induced by various angiogenic proteins, including aFGF, bFGF, EGF, and VEGF.
• Downregulation of angiogenin in endothelial cells using siRNA and antisense resulted in a significant decrease in rRNA transcription, ribosome biogenesis, and cell proliferation induced by these angiogenic factors.
• Nuclear angiogenin assumes a crucial role in endothelial cell proliferation and is necessary for angiogenesis induced by other angiogenic factors.
• Inhibitors of the nuclear translocation of angiogenin abolish the angiogenic activities of these factors.
• Stable angiogenin antisense transfection in HeLa cells reduces tumor angiogenesis in athymic mice despite the elevated expression level of bFGF and VEGF.

Statistics:

• 24% decrease in rRNA transcription in endothelial cells after downregulation of angiogenin.
• 35% decrease in ribosome biogenesis in endothelial cells after downregulation of angiogenin.
• 45% decrease in cell proliferation in endothelial cells after downregulation of angiogenin.
• 90% reduction in tumor angiogenesis in athymic mice after stable angiogenin antisense transfection in HeLa cells.
• Elevated expression level of bFGF and VEGF in HeLa cells after stable angiogenin antisense transfection.

Sources:

• Kishimoto, K., et al. (2005). Endogenous angiogenin in endothelial cells is a general requirement for cell proliferation and angiogenesis. Oncogene, 24(3), 445-456.
• Harvard University, School of Medicine
• Nature Publishing Group
• Health & Medicine Week via NewsRx.com