ObjectiveTo observe the effects of overexpression of S100A4 protein on retinal capillary cells and retinal ganglion cells (RGC) after retinal ischemia-reperfusion injury (RIRI). MethodsOne hundred healthy adult male C57BL/6 mice were randomly divided into normal control group (group C), RIRI group, adeno-associated virus (AAV2)-S100A4 green fluorescent protein (GFP) intravitreal injection group (group S), RIRI+AAV2-GFP intravitreal injection group (group GIR), and RIRI+AAV2-S100A4-GFP intravitreal injection group (group SIR), with 20 mice in each group. The RIRI model was established using the high intraocular pressure anterior chamber method in the RIRI, GIR and SIR groups of mice. Eyes were enucleated 3 days after modelling by over anaesthesia. The number of retinal capillary endothelial cells and pericytes in the retinal capillaries of mice in each group was observed by retinal trypsinised sections and hematoxylin-eosin and periodic acid-Schiff staining; immunofluorescence staining was used to observe endothelial cell, pericyte coverage and RGC survival; The relative expression of Toll-like receptor 4 (TLR4), p38 MAPK and nuclear factor erythroid 2-related factor 2 (NRF2) in retinal tissues was measured by Western blot. One-way analysis of variance was used to compare data between groups. ResultsThree days after modeling, the endothelial cell to pericyte ratio in group C was compared with group S and SIR, and the difference was not statistically significant (F=106.30, P＞0.05); the SIR group was compared with group RIRI and GIR, and the difference was statistically significant (F=106.30, P＜0.000 1). Comparison of endothelial cell coverage in each group, the difference was not statistically significant (F=3.44, P＞0.05); compared with the pericyte coverage in group C, the RIRI group and the GIR group were significantly lower, and the difference was statistically significant (F=62.69, P＜0.001). Compared with the RGC survival rate in group C, it was significantly lower in RIRI and GIR groups, and the difference was statistically significant (F=171.60, P＜0.000 1); compared with RIRI and GIR groups, the RGC survival rate in SIR group was significantly higher, and the difference was statistically significant (F=171.60, P＜0.000 1). The relative expression levels of TLR4, p38 and NRF2 proteins were statistically significant among all groups (F=42.65, 20.78, 11.55; P＜0.05). ConclusionsPericytes are more sensitive to ischemia than endothelial cells after retinal RIRI in mice, and early vascular cell loss is dominated by pericytes rather than endothelial cells. The overexpression of S100A4 protein protects against loss of pericytes and RGC after RIRI by inhibiting the TLR4/p38/NRF2 signaling pathway.
[Abstract]Objective To observe the clinical and imaging features of non-arteriotic central retinal artery occlusion (NA-CRAO) with internal boundary membrane detachment (ILMD), and to analyze its relationship with visual prognosis. MethodsA retrospective clinical study. A total of 88 patients with NA-CRAO hospitalized in Department of Ophtalmology, Xi'an People's Hospital (Xi'an Fourth Hospital) from January 2014 to June 2023 were included in the study. Best corrected visual acuity (BCVA), optical coherence tomography (OCT) and fluorescein fundus angiography (FFA) were performed. The BCVA test used the international standard visual acuity chart, which was statistically converted to the logMAR visual acuity. OCT observed the presence of ILMD and the thickening of the inner retina and the disappearance of anatomical stratification. FFA recorded arm-retinal circulation time (A-Rct) and retinal arterion-distal filling time (FT), and observed ciliary retinal artery, fluorescein retrograde filling, cotton spots, luciferin nodal filling, macular non-perfusion, capillary fluorescein leakage, optic disc strong fluorescence, choroidal background weak fluorescence and other characteristics. According to whether there was ILMD, the patients were divided into ILMD group and non-ILMD group, with 44 cases and 44 eyes respectively. The two groups received the same treatment. The follow-up time was 30 days after treatment. The clinical, FFA characteristics and BCVA before and after treatment were compared between the two groups. t-test was used for comparison between groups. ResultsIn ILMD group and non-ILMD group, there were 43 cases of male and 1 case of female, respectively, and the proportion of male was significantly higher than that of female. Before and after treatment, the logMAR BCVA of ILMD group and non-ILMD group were 2.35±0.42, 2.01±0.46, 1.47±0.60, 0.77±0.49, respectively. There were significant differences in logMAR BCVA between the two groups before and after treatment (t=8.025, 12.358; P＜0.001). Before treatment, A-Rct and FT in ILMD group were longer than those in non-ILMD group, and the difference was statistically significant (t=3.052, 3.385; P＜0.05). After treatment, there was no significant difference (t=1.040, 1.447; P＞0.05). The proportion of ciliary retinal artery and cotton plaque in ILMD group was lower than that in non-ILMD group. There was no significant difference in ciliary retinal artery between the two groups (χ2=－0.961, P＞0.05), but there was a significant difference in cotton wool plaque between the two groups (χ2=－3.364, P＜0.05). Compared to the non-ILMD group, The proportion of retrograde fluorescein filling in retinal artery (χ2=－2.846), segment filling (χ2=－3.907), macular non-perfusion (χ2=－6.656), capillary fluorescein leakage (χ2=－4.367), optic disc strong fluorescence (χ2=－3.525) and choroidal background weak fluorescence (χ2=－2.276) increased, the difference was statistically significant (P＜0.05). ConclusionsIn patients with NA-CRAO, compared with those without ILMD, those with ILMD have more severe retinal ischemia and worse BCVA before and after treatment. ILMD is one of the poor prognostic markers of NA-CRAO vision.