Abstract
Purpose :
Our previous studies have reported the protective effect of Lycium Barbarum polysaccharides (LBP) on retinal ganglion cells (RGCs) in acute ocular hypertensive (AOH) mice. However, whether visual function would be recovered along with survival of RGCs remained unknown. The reaction of retinal glial cells during neuron damage in AOH insult is also needed to be investigated. The purpose of this study is to evaluate the effects of LBP on visual function of AOH mice and glial reactivity in AOH retina.
Methods :
AOH mouse model was established in unilateral eye for one hour by introducing 90 mmHg of ocular pressure. The animals were grouped and fed with LBP solution (1mg/kg) or PBS vehicle daily from 7 days before the AOH insult till sacrifice at day 4 post operation. The control group was come from the same-aged normal eyes. Visual functions were analyzed using optokinetic test (OKT) and electroretinography (ERG). Retinal glial cells were analyzed by the number counting (for astrocytes and microglia) as well as the associated biomarker changes using S-100, GFAP, GS, AQP-4 and Iba-1.
Results :
LBP reduced RGC loss in AOH insult, which data was as same as our previous report. The improvement of animal's visual function in LBP+AOH group was detected on OKT scores with 0.218±0.013 cpd vs. 0.150±0.014 cpd in PBS+AOH group (p=0.04, n=15), and amplitude of ERG waves (LBP+AOH group vs. PBS+AOH group as 27.76±1.79μV vs. 20.40±1.75μV in PhNR; 84±3% vs. 66±2% of baseline values in a-waves; 67±2% vs. 59±3% of baseline values in b-waves, p<0.01, n=15). The number of astrocytes and microglia were increased after AOH insult. However, less increased numbers of glials were observed in LBP+AOH group with 43.5% of increased astrocytes vs. 98.3% in PBS+AOH group (p=0.004, n=15) and 25.9% of increased microglia in LBP+AOH group vs. 61.4% in PBS+AOH group (p=0.005, n=15). Histologic data showed the changed expression of biomarkers for astrocytes, Müller cells and microglia in LBP+AOH group vs. PBS+AOH group.
Conclusions :
The present study suggests LBP could improve visual function of AOH mice. The neuroprotective role of LBP is related to regulate the reactivity of retinal glial cells. The remolding effect of LBP on retinal astrocytes was distinct. Further examination will be needed to understand the significance of this kind of morphological remolding.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.