Pericyte-Endothelial Interactions in the Retinal Microvasculature

Area of Science:

• Ophthalmology
• Vascular Biology
• Cell Biology

Background:

• The retinal microvasculature, composed of pericytes and endothelial cells (ECs), is essential for vision.
• Pericyte-EC interactions are critical for microvascular formation, maturation, and stability, and their perturbation underlies retinal vascular diseases.
• Dysfunctional communication between pericytes and ECs compromises the retinal neurovascular unit (NVU).

Purpose of the Study:

• To review the fundamental knowledge and recent advancements in pericyte-endothelial cell interactions within the retinal microvasculature.
• To highlight the molecular mechanisms governing these interactions and their disruption in disease.
• To explore the role of extracellular exosomes in pericyte-EC communication.

Main Methods:

• Literature review of studies on retinal microvasculature, pericyte-endothelial cell interactions, and associated signaling pathways.
• Analysis of established and emerging molecular mechanisms regulating vascular development and pathology.
• Synthesis of current understanding of factors disrupting cell communication, including oxidative stress, inflammation, and exosomes.

Main Results:

• Key signaling pathways (VEGF, PDGFB, Notch, Angiopoietin, Norrin, TGF-β) are crucial for pericyte-EC interactions during development and in mature vasculature.
• Disruptions in signaling, metabolism, oxidative stress, and inflammation can impair pericyte-EC communication, leading to blood-retinal barrier (BRB) breakdown and microangiopathies.
• Extracellular exosomes are increasingly recognized as mediators of communication, both normal and aberrant, between pericytes and ECs.

Conclusions:

• Understanding pericyte-EC interactions is fundamental for addressing retinal vascular disorders.
• Therapeutic strategies targeting these interactions hold promise for preventing and treating diseases like diabetic retinopathy and retinopathy of prematurity.
• Further research into exosome-mediated communication could reveal novel therapeutic targets for retinal vascular diseases.