Abstract
Abstract: :
Purpose: To determine whether gap junction protein, connexin-43 (Cx43), plays a role in the maintenance of vascular homeostasis in diabetic retinopathy. This study examined whether high glucose condition alters the expression of Cx43 and gap junction intercellular communication (GJIC) activity in retinal pericytes. Methods: Western blot analysis was performed to determine Cx43 protein level in human and bovine retinal pericytes grown for 8 days in normal (5mM) or high (30mM) glucose medium. In parallel experiments performed with human retinal pericytes, GJIC activity was assessed using the scrape load dye transfer technique. Results: Western blot analysis showed Cx43 expression was reduced in bovine retinal pericytes (53.8±16.9% of control, p=0.01, n=4) and in human retinal pericytes (49.0±23% of control, p=0.02, n=4) grown in high glucose medium compared to cells grown in normal medium. The ability of the cells to transfer Lucifer yellow through gap junctions was also reduced in high glucose condition (49±25% of control, p=0.04, n=3). Conclusion: High glucose condition reduces Cx43 expression in retinal pericytes and inhibits GJIC activity. Maintenance of retinal vascular homeostasis through gap junctions may be disturbed by high glucose condition and result in pericyte dysfunction in diabetic retinopathy.
Keywords: 388 diabetic retinopathy • 340 cell-cell communication • 614 vascular cells