Objective: Hyperglycemia-induced inflammation is critical in diabetic retinopathy, and toll-like receptors 2 and TLR4 which are expressed in endothelial cells may play a key role in this process. In this study, we examined the expression of TLR2 and TLR4 in endothelial cells under hyperglycemia condition.

Methods: Human microendothelial cells (HMEC-1) were cultured with glucose at doses of 5, 15 and 25 mM for 12 or 24 hours. The expression of TLR2 and TLR4 were examined by flow cytometry and real-time PCR and the cytokine production in the culture supernatant was analyzed by ELISA.

Results: The results showed that high glucose promoted the expression of TLR2, TLR4 and IL-1β by endothelial cells. TLR4 knock-down by siRNA ameliorated the IL-1β production by HMEC-1 cells.

Conclusions: These data suggest that hyperglycemia may induce the expression of TLR2 and TLR4 in human endothelial cells, and the enhancing secreted of inflammatory factors which may play important role in pathogenesis of diabetic retinopathy.