Protective effects of hydrogen gas in a rat model of branch retinal vein occlusion via decreasing VEGF-α expression

Abstract

Background: Oxidative stress (OS) is an essential factor in the pathogenesis of branch retinal vein occlusion (BRVO). Studies have demonstrated the role of hydrogen gas in the regulation of OS. This study was designed to evaluate the effecacy of hydrogen gas on the BRVO rat model. Methods: Twenty-four BRVO rats were randomly divided into two groups: the hydrogen gas (H) group (42% H2, 21% O2, 37% N2) and the model (M) group (21% O2, 79% N2). Rats in the H group inhaled hydrogen gas for 8 h every day up to 30 d post-occlusion. Twelve age-matched healthy rats served as the control (C) group. Retinal function and morphology were detected at 1, 7, 14 and 30 d post-occlusion. Furthermore, the expression of vascular endothelial growth factor (VEGF-α) was detected by immunofluorescent staining. Results: Full-field electroretinography (ffERG) revealed that the amplitude of the b-wave (dark-adaptation 3.0 response), the amplitude of the OPs2 wave and the light-adapted flicker response in the H group were all higher than those in the M group at 7 d post-occlusion (all p<0.05). The reopen time of occlusive retinal vessels in the H group was 2.235 ± 1.128 d, which was shorter than that in the M group (4.234±2.236 d, p<0.05). The rats in the H group had a thinner IPL+GCL+NFL and an increased total retina compared with those in the M group at 3 d post-occlusion (p<0.05), while the rats in the H group had a thicker INL, IPL+GCL+NFL and total retina compared with those at 7, 14 and 30 d post-occlusion (p<0.05). Moreover, the flow velocity of ear vein blood was increased in the H group compared with that in the M group (p<0.05). The expression of VEGF-α in the H group was dramatically decreased compared with that in the M group at 1, 7 and 14 d post-occlusion (p<0.05), while the expression kept in similar level at 30 d post-occlusion (p>0.05). Conclusions: Our findings demonstrate that inhalation of hydrogen gas could alleviate retinal oedema, shorten reopen time and improve retinal function, and the potential mechanism might be related to a decrease in VEGF-α expression.

Protective Effect of Vitamin C against Infancy Rat Corneal Injury Caused by Acute UVB Irradiation

“…Six paraffin-embedded sections (thickness: 4 μm) were cut along the transverse plane to enable discrimination of the nasal and temporal sides of each tissue slice. Then, the eye sections were prepared in the standard manner and stained with HE as previously described [19,20].…”

“…Immunofluorescence staining was performed according to the manufacturer's instructions at 7 d post-UVB irradiation (n = 3). Eye paraffin sections were deparaffinized in dimethylbenzene and dehydrated in gradient ethyl alcohol as previously described [20]. Then, the sections were washed with PBS (phosphatebuffered saline) (0.1 mM, pH = 7:2 ± 0:1) 3 times for 5 min.…”

Protective effect of aldehyde dehydrogenase 2 against rat corneal dysfunction caused by streptozotocin-induced type I diabetes

“…Immunofluorescence staining was performed at one, two, and three months after T1DM induction ( n = 4 rats) as previously described. 31 Anti-ALDH2 (Abcam, ab108306, USA) and anti-VEGF-A (GeneTex, GTX102643, USA) primary antibodies diluted 1:100 were used. Then, FitC-conjugated IgG (H + L fluorescent secondary antibodies (Zhuangzhi, EK023, China) were used at a dilution of 1:200.…”