The Effect of Thyroxin on the Biological Effects of High Glucose-Induced Human Retinal Endothelial Cells and B-Cell Lymphoma 2/Bcl-2 Associated X

This study intends to assess the biological effect of TTR on human retinal endothelial cells under high glucose. Cells were assigned into normal group, high glucose (HG) group and TTR intervention group followed by analysis of cell biological activity and protein expression. The retinal endothelial cell proliferation rate was significantly promoted in HG group (P < 0.05) and inhibited in intervention group (P < 0.05). The HG group had significantly higher cell migration number than normal group (P < 0.05). However, migrated cell number in intervention group was reduced significantly (P < 0.05). In addition, high glucose also significantly enhanced the invasion of retinal endothelial cells (P < 0.05), which was inhibited after TTR intervention (P < 0.05). Moreover, Bcl-2 protein was significantly downregulated and Bax was upregulated in HG group compared to normal group (P < 0.05). Interestingly, their levels were normalized after TTR intervention without difference compared to their levels in normal group (P < 0.05). Consistently, the mRNA level of Bcl-2 and Bax showed similar expression profiles to the protein expression in different groups (P < 0.05). In conclusion, TTR can inhibit the retinal endothelial cell proliferation, migration and invasion ability and regulate Bcl-2/Bax expression.