Abstract:

Objective To investigate the expression of ELR+ and ELR-CXC chemokines in diabetic rats induced by streptozotocin (STZ). Methods Thirty-four healthy male Wistar rats were randomly divided into control group (CON group, n=10), diabetes mellitus 2 months group (DM2M group, n=12) and diabetes mellitus 4 months group (DM4M group, n=12). Rat diabetes model was induced by a single intraperitoneal injection of STZ (65 mg/kg). Left ventricular perfusion of Evens blue was performed, and microvascular proliferation was observed with retinal preparations. The expression of chemokines in the serum, retina and vitreous humor of each group was detected by ELISA, and statistical analysis was conducted. The expression of CXCR3 in retina was observed with immunofluorescence staining. Results The expression of ELR+ CXC chemokines of GRO, ENA-78, SDF-1 and that of ELR- CXC chemokines IP-10 and MIG in DM2M group and DM4M group was significantly higher than that in CON group (P<0.01). The expression of chemokines in DM4M group was significantly higher than that in DM2M group (P<0.05). The expression of chemokines in retina was significantly higher than that in vitreous humor and serum (P<0.05). The expression of CXCR3 in retina in DM4M group and DM2M group was relatively higher, especially for DM4M group, and the expression of CXCR3 was mainly found in the inner granular layer and nerve fiber layer. Conclusion ELR+ and ELR- CXC chemokines may participate in the development of diabetic retinopathy, which may play an important role in mediating vascular proliferation and fibration.

Key words: diabetic retinopathy, retina, vitreous body, chemokines, chemokine receptor