The impact of 1,25-dihydroxy vitamin D3 on the expressions of vascular endothelial growth factor and transforming growth factor-β1 in the retinas of rats with diabetes

AimsTo define whether 1,25-dihydroxy vitamin D3 (1,25-(OH)2 D3) can protect diabetic retinopathy and to investigate its impact on the expressions of vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1) in the retinas of rats with diabetes.MethodsMale Sprague-Dawley (SD) rats were divided into normal control group, 1,25-(OH)2 D3 group and diabetes group. The rats in 1,25-(OH)2 D3 group and diabetes group were established to type 2 diabetes model with high-fat and high-sugar diet and streptozotocin (STZ). Meanwhile, the rats of 1,25-(OH)2 D3 group were treated with 1,25-(OH)2 D3. After 13 weeks, morphological changes of retinal tissues were observed under microscopes after hematoxylin–eosin staining. VEGF and TGF-β1 expressions in the retinal tissues were detected with immunohistochemistry staining.ResultsPathological examination showed an appearance of edema and disordered arrangement of retinal tissues in diabetes group, but milder pathological changes in 1,25-(OH)2 D3 group. VEGF and TGF-β1 expressions of both diabetes group and 1,25-(OH)2 D3 group significantly increased (P < 0.05), but those of 1,25-(OH)2 D3 group were significantly lower than diabetes group (P < 0.05).Conclusion1,25-(OH)2 D3 had partially protective effect on diabetic retinopathy of diabetic rats, the mechanism of which might inhibit VEGF and TGF-β1 expressions in the retinal tissues.