Muller glial dysfunction during diabetic retinopathy in rats is linked to accumulation of advanced glycation end-products and advanced lipoxidation end-products

作者：Curtis T M; Hamilton R; Yong P H; McVicar C M; Berner A; Pringle R; Uchida K; Nagai R; Brockbank S; Stitt A W^*

来源：Diabetologia, 2011, 54(3): 690-698.

DOI：10.1007/s00125-010-1971-x

• Advanced glycation end-products
• Advanced lipoxidation end-products
• AGE
• ALE
• Diabetic retina
• Microvascular dysfunction
• Muller glial cells
• Retinopathy

The impact of AGEs and advanced lipoxidation end-products (ALEs) on neuronal and Muller glial dysfunction in the diabetic retina is not well understood. We therefore sought to identify dysfunction of the retinal Muller glia during diabetes and to determine whether inhibition of AGEs/ALEs can prevent it.
Sprague-Dawley rats were divided into three groups: (1) non-diabetic; (2) untreated streptozotocin-induced diabetic; and (3) diabetic treated with the AGE/ALE inhibitor pyridoxamine for the duration of diabetes. Rats were killed and their retinas were evaluated for neuroglial pathology.
AGEs and ALEs accumulated at higher levels in diabetic retinas than in controls (p < 0.001). AGE/ALE immunoreactivity was significantly diminished by pyridoxamine treatment of diabetic rats. Diabetes was also associated with the up-regulation of the oxidative stress marker haemoxygenase-1 and the induction of glial fibrillary acidic protein production in Muller glia (p < 0.001). Pyridoxamine treatment of diabetic rats had a significant beneficial effect on both variables (p < 0.001). Diabetes also significantly altered the normal localisation of the potassium inwardly rectifying channel Kir4.1 and the water channel aquaporin 4 to the Muller glia end-feet interacting with retinal capillaries. These abnormalities were prevented by pyridoxamine treatment.
While it is established that AGE/ALE formation in the retina during diabetes is linked to microvascular dysfunction, this study suggests that these pathogenic adducts also play a role in Muller glial dysfunction.

• 出版日期2011-3