Relationship between glycoxidation and cytokines in the vitreous of eyes with diabetic retinopathy.

PURPOSE

To investigate the correlations among pentosidine, an advanced glycation end product, and related cytokines (vascular endothelial growth factor [VEGF], transforming growth factor [TGF]-beta(2), and monocyte chemotactic protein [MCP]-1), and active oxygen in the vitreous of patients with diabetic retinopathy (DR).

METHODS

Vitreous samples from 43 eyes that underwent vitrectomy to treat DR were divided into four subgroups and analyzed. Vitreous samples from 21 eyes of patients with no systemic conditions served as age- and sex-matched controls. The vitreous levels of pentosidine, cytokines, and hydrogen peroxide (H(2)O(2)) were determined by high-performance liquid chromatography, enzyme-linked immunosorbent assay, and the titanium-hydrogen peroxide colorimetric method, respectively.

RESULTS

The levels of pentosidine, VEGF, total TGF-beta(2), and MCP-1 in the vitreous samples of eyes with DR were significantly higher than in the controls (P <.01). Significant correlations (P <.01) were found between pentosidine and VEGF, pentosidine and H(2)O(2), H(2)O(2) and VEGF, and total TGF-beta(2) and MCP-1 (r = 0.62, 0.58, 0.65, and 0.59, respectively).

CONCLUSIONS

These results suggest that elevated levels of pentosidine may cause increased levels of VEGF in the vitreous of patients with DR. Increased levels of total TGF-beta(2) and MCP-1 together also might play an important role in the development of DR.