Shifts in renin–angiotensin system components, angiogenesis,
and oxidative stress-related protein expression in the lamina cribrosa
region of streptozotocin-induced diabetic mice
Received: 16 June 2017 /Revised: 26 October 2017 /Accepted: 11 December 2017 / Published online: 5 February 2018
Springer-Verlag GmbH Germany, part of Springer Nature 2018
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, histo-
pathological staining showed significant reduction in the whole retinal thickness. GFAP expression was slightly higher, whereas
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.
Keywords Diabetic retinopathy
Diabetes mellitus is a serious disease because of its high prev-
alence and associated mortality, accounting for approximately
5.1 million deaths globally in 2013 . It affected approxi-
mately 2.8% of the population worldwide in 2000, and its
prevalence is expected to increase to 4.4% by 2030 .
Diabetic retinopathy (DR), an irreversible blinding eye dis-
ease, is frequently observed in patients with long-term
diabetes . Laser photocoagulation, intravitreal injection of
anti-vascular endothelial growth factor (VEGF) agents, and
surgery are the currently available treatment modalities for
macular oedema and late-stage DR . However, DR pro-
gresses slowly before becoming symptomatic (e.g. aneurysm,
vascular leakage, neovascularisation); therefore, it is difficult
to accurately determine diabetes duration .
Both the central retinal artery (CRA) and central retinal vein
(CRV) are crucial for maintaining normal visual function be-
cause they are the only vascular structures to serve the inner
retina [6, 7]. The lamina cribrosa (LC) comprises glial columns
and connective tissue plates that align to form channels that
guide and support ganglion cell axons as they exit the eye .
* Qianying Gao
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic
Center, Sun Yat-sen University, Guangzhou 510060, China
Graefe's Archive for Clinical and Experimental Ophthalmology (2018) 256:525–534