Department of Vision Science, School of Optometry, The University of Alabama at Birmingham, Birmingham, AL, USA.
Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA.
Transl Vis Sci Technol. 2023 Apr 3;12(4):20. doi: 10.1167/tvst.12.4.20.
The expression of silent information regulator (SIRT) 1 is reduced in diabetic retinopathy (DR). Previous studies showed that alterations in SIRT1 messenger RNA (mRNA) and protein expression are implicated in progressive inflammation and formation of retinal acellular capillaries. Treatment with the SIRT1 agonist, SRT1720, improved visual response by restoration of a- and b-wave responses on electroretinogram scotopic measurements in diabetic (db/db) mice. In this study, we investigated the effects of intravitreal SIRT1 delivery on diabetic retinal pathology.
Nine-month-old db/db mice received one intravitreal injection of either AAV2-SIRT1 or AAV2-GFP control virus, and after 3 months, electroretinography and optomotor responses were measured. Their eyes were then removed and analyzed by immunohistochemistry and flow cytometry.
SIRT1 mRNA and protein levels were increased following AAV2-SIRT1 administration compared to control virus AAV2-GFP injected mice. IBA1+ and caspase 3 expression were decreased in retinas of db/db mice injected with AAV2-SIRT1, and reductions in scotopic a- and b-waves and high spatial frequency in optokinetic response were prevented. Retinal hypoxia inducible factor 1α (HIF-1α) protein levels were reduced in the AAV2-SIRT1-injected mice compared to control-injected mice. Using flow cytometry to assess changes in intracellular HIF-1α levels, endothelial cells (CD31+) from AAV-2 SIRT1 injected mice demonstrated reduced HIF-1α expression compared to db/db mice injected with the control virus.
Intravitreal AAV2-SIRT1 delivery increased retina SIRT1 and transduced neural and endothelial cells, thus reversing functional damage and improving overall visual function.
AAV2-SIRT1 gene therapy represents a beneficial approach for the treatment of chronic retinal conditions such as DR.
沉默信息调节因子（SIRT）1 的表达在糖尿病性视网膜病变（DR）中减少。先前的研究表明，SIRT1 信使 RNA（mRNA）和蛋白质表达的改变与进行性炎症和视网膜无细胞毛细血管的形成有关。用 SIRT1 激动剂 SRT1720 治疗可改善糖尿病（db/db）小鼠视网膜电图暗适应测量中的 a 波和 b 波反应，从而改善视觉反应。在这项研究中，我们研究了玻璃体内 SIRT1 传递对糖尿病性视网膜病变的影响。
9 个月大的 db/db 小鼠接受单次玻璃体内注射 AAV2-SIRT1 或 AAV2-GFP 对照病毒，3 个月后测量视网膜电图和光动反应。然后取出眼睛并通过免疫组织化学和流式细胞术进行分析。
与注射对照病毒 AAV2-GFP 的小鼠相比，AAV2-SIRT1 给药后 SIRT1 mRNA 和蛋白质水平增加。db/db 小鼠注射 AAV2-SIRT1 后，IBA1+和 caspase 3 的表达减少，暗适应 a 波和 b 波以及光动反应的高频减少得到预防。与注射对照病毒的小鼠相比，AAV2-SIRT1 注射小鼠的视网膜缺氧诱导因子 1α（HIF-1α）蛋白水平降低。通过流式细胞术评估细胞内 HIF-1α 水平的变化，与注射对照病毒的 db/db 小鼠相比，注射 AAV-2 SIRT1 的内皮细胞（CD31+）的 HIF-1α表达减少。
玻璃体内 AAV2-SIRT1 传递增加了视网膜 SIRT1 并转导了神经和内皮细胞，从而逆转了功能损伤并改善了整体视觉功能。
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