What factor does the retinal pigment epithelium secrete to counteract VEGF?

What factor does the retinal pigment epithelium secrete to counteract VEGF?

• A. VEGF
• B. PEDF
• C. IGF-1
• D. EPO

Answer: (B)

The retinal pigment epithelium maintains a balance of angiogenic and anti-angiogenic signals, and the factor it secretes to counteract VEGF is PEDF. PEDF helps keep blood vessel growth in check by inhibiting endothelial cell proliferation and promoting their apoptosis, opposing the pro-angiogenic effects of VEGF. This anti-angiogenic influence from the RPE is crucial for preserving retinal structure; when PEDF is reduced relative to VEGF, neovascularization can occur, as seen in diseases like AMD. The other candidates don’t specifically counteract VEGF in this context: VEGF itself promotes angiogenesis, while IGF-1 and EPO have other roles and do not function as the primary anti-VEGF factor produced by the RPE.

The retinal pigment epithelium maintains a balance of angiogenic and anti-angiogenic signals, and the factor it secretes to counteract VEGF is PEDF. PEDF helps keep blood vessel growth in check by inhibiting endothelial cell proliferation and promoting their apoptosis, opposing the pro-angiogenic effects of VEGF. This anti-angiogenic influence from the RPE is crucial for preserving retinal structure; when PEDF is reduced relative to VEGF, neovascularization can occur, as seen in diseases like AMD. The other candidates don’t specifically counteract VEGF in this context: VEGF itself promotes angiogenesis, while IGF-1 and EPO have other roles and do not function as the primary anti-VEGF factor produced by the RPE.