Pigment epithelium-derived factor and its role in microvascular-related diseases.

Microvascular diseases are among the most clinically important diseases, and vascular abnormalities are central in the development of such diseases. Pigment epithelium-derived factor (PEDF), a potent inhibitor of angiogenesis, exerts antiangiogenic effects without affecting the structure and function of normal blood vessels. PEDF also has neurotrophic effects, which may be a potential direction for the future treatment of angiogenic diseases with lower side effects. Here, we review (i) the expression levels of PEDF in several important organs and clinically common microvascular diseases and (ii) the effects of its absence and presence on the vasculature and nerves, focusing on both angiogenic and neuroprotective aspects. These effects are both positive and negative, and have the potential to be exploited. Additionally, we summarize and compare various PEDF agents and their possible advantages and disadvantages as therapeutic agents, which, despite most still being in the experimental stage, may provide some new opportunities for future clinical treatments and interventions in PEDF-targeted microvascular diseases.