Ye EA – This study investigated the hypothesis that transforming growth factor beta 3 (TGF–beta3)/ vascular endothelial growth factor (VEGF) signaling inhibition by miR–15a/16 may maintain endothelial cell barrier protein levels. The authors concluded that miR–15a/16 may maintain the retinal endothelial cell barrier protein levels by reducing TGF–beta3/VEGF signaling and increasing the levels of key tight junction proteins.

Methods

• Human primary retinal endothelial cells (REC) were maintained in normal (5 mM) glucose or transferred to high glucose medium (25 mM) for 3 days and transfected with miRNA mimics (hsa–miR–15a–5p and –16–5p)

Results

• Overexpression of miR–15a/16 decreased TGF–beta3 signaling and VEGF levels, and tight junction proteins, zonula occludens–1 (ZO–1), and occludin levels were elevated in cultured REC grown in high glucose conditions.
• Cellular permeability reduced by inhibiting VEGF signaling.