Xiaobing Qian1, Leilei Lin1, Yao Zong1, Yongguang Yuan1, Yanmin Dong1, Yue Fu1, Wanwen Shao1, Yujie Li1, Qianying Gao2. 1. State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China. 2. State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China. gaoqy@mail.sysu.edu.cn.
Abstract
PURPOSE: This study aimed to analyse shifts in renin-angiotensin system (RAS) components, angiogenesis, and oxidative stress-related protein expression in the lamina cribrosa (LC) region in streptozotocin (STZ)-induced diabetic mice. METHODS: Six months after diabetes induction, the retinal vessels of male C57BL/6 J mice were observed by colour photography, fundus fluorescein angiography (FFA), and immunofluorescent staining following incubation with CD31. Immunofluorescence for glial fibrillary acidic protein (GFAP), alpha-smooth muscle actin (α-SMA),and NG2 was also performed. Angiotensin-converting enzyme 1 (ACE1), angiotensin II type I receptor (AT1R), renin, hypoxia-inducible factor 1-alpha (HIF-1α), vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR2), and haeme oxygenase 1 (HO-1) expression levels were confirmed by immunohistochemical and western blotting analyses. RESULTS: Compared with control mice, diabetic mice had significantly higher blood glucose concentrations (p < 0.001) and significantly lower body weights (p < 0.001). Colour photography and FFA did not reveal any vessel abnormalities in the diabetic mice; however, immunostaining of whole-mount retinas revealed an increased number of retinal vessels. Furthermore, histopathological staining showed significant reduction in the whole retinal thickness. GFAP expression was slightly higher, whereas fewer NG2+ pericytes were observed in diabetic mice than in control mice. ACE1, AT1R, renin, HIF-1α, VEGF, VEGFR2, and HO-1 expression were up-regulated in the LC of the STZ-induced diabetic mice. CONCLUSIONS: Collectively, ACE 1, AT1R, HIF-1α, VEGF, VEGFR2, and HO-1 activation in the LC region in diabetic mice may be involved in diabetes via the RAS and induction of angiogenesis and oxidative stress.
PURPOSE: This study aimed to analyse shifts in renin-angiotensin system (RAS) components, angiogenesis, and oxidative stress-related protein expression in the lamina cribrosa (LC) region in streptozotocin (STZ)-induced diabeticmice. METHODS: Six months after diabetes induction, the retinal vessels of male C57BL/6 J mice were observed by colour photography, fundus fluorescein angiography (FFA), and immunofluorescent staining following incubation with CD31. Immunofluorescence for glial fibrillary acidic protein (GFAP), alpha-smooth muscle actin (α-SMA),and NG2 was also performed. Angiotensin-converting enzyme 1 (ACE1), angiotensin II type I receptor (AT1R), renin, hypoxia-inducible factor 1-alpha (HIF-1α), vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR2), and haeme oxygenase 1 (HO-1) expression levels were confirmed by immunohistochemical and western blotting analyses. RESULTS: Compared with control mice, diabeticmice had significantly higher blood glucose concentrations (p < 0.001) and significantly lower body weights (p < 0.001). Colour photography and FFA did not reveal any vessel abnormalities in the diabeticmice; however, immunostaining of whole-mount retinas revealed an increased number of retinal vessels. Furthermore, histopathological staining showed significant reduction in the whole retinal thickness. GFAP expression was slightly higher, whereas fewer NG2+ pericytes were observed in diabeticmice than in control mice. ACE1, AT1R, renin, HIF-1α, VEGF, VEGFR2, and HO-1 expression were up-regulated in the LC of the STZ-induced diabeticmice. CONCLUSIONS: Collectively, ACE 1, AT1R, HIF-1α, VEGF, VEGFR2, and HO-1 activation in the LC region in diabeticmice may be involved in diabetes via the RAS and induction of angiogenesis and oxidative stress.
Entities:
Keywords:
Angiogenesis; Diabetic retinopathy; Lamina cribrosa; Oxidative stress; Renin–angiotensin system