University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Coimbra, Portugal; University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal; Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal; Department of Ophthalmology, Centro Hospitalar Leiria E. P. E., Leiria, Portugal; ciTechCare, Center for Innovative Care and Health Technology, Polytechnic Institute of Leiria, Leiria, Portugal.
University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Coimbra, Portugal; University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal; Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal; University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Coimbra, Portugal; University of Coimbra, Instituto de Ciências Nucleares Aplicadas à Saúde (ICNAS), Coimbra, Portugal.
Biomed Pharmacother. 2020 Dec;132:110811. doi: 10.1016/j.biopha.2020.110811. Epub 2020 Oct 15.
Increasing evidence points to inflammation as a key factor in the pathogenesis of diabetic retinopathy (DR). Choroidal changes in diabetes have been reported and several attempts were made to validate in vivo choroidal thickness (CT) as a marker of retinopathy. We aimed to study choroidal and retinal changes associated with retinopathy in an animal model of spontaneous Type 2 diabetes, Goto-Kakizaki (GK) rats. Sclerochoroidal whole mounts and cryosections were prepared from 52-week-old GK and age-matched control Wistar Han rats. CT was measured by optical coherence tomography. Microglia reactivity, pericyte and endothelial cells distribution, and immunoreactivity of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2) were evaluated by immunofluorescence. Choroidal vessels were visualized by direct perfusion with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (Dil). Choroidal vascular density was evaluated by fluorescence microscopy. GK rats had increased CT (58.40 ± 1.15 μm versus 50.90 ± 1.58 μm, p < 0.001), reduced vascular density of the choriocapillaris (CC) (p = 0.045), increased Iba1 cells density in the outer retina (p = 0.003) and increased VEGFR2 immunoreactivity in most retinal layers (p = 0.021 to 0.037). Choroidal microglial cells and pericytes showed polarity in their distribution, sparing the innermost choroid. This cell-free gap in the inner choroid was more pronounced in GK rats. In summary, GK rats have increased CT with decreased vascular density in the innermost choroid, increased VEGFR2 immunoreactivity in the retina and increased Iba1 cells density in the outer retina.
越来越多的证据表明炎症是糖尿病性视网膜病变（DR）发病机制中的一个关键因素。已经报道了糖尿病患者脉络膜的变化，并且已经尝试了几种方法来验证活体脉络膜厚度（CT）作为视网膜病变的标志物。我们旨在研究自发性 2 型糖尿病动物模型，即 Goto-Kakizaki（GK）大鼠中与视网膜病变相关的脉络膜和视网膜变化。从 52 周龄的 GK 大鼠和年龄匹配的对照 Wistar Han 大鼠中制备了巩膜脉络膜全层和冷冻切片。通过光学相干断层扫描测量 CT。通过免疫荧光评估小胶质细胞反应性、周细胞和内皮细胞分布以及血管内皮生长因子（VEGF）和血管内皮生长因子受体 2（VEGFR2）的免疫反应性。通过直接用 1,1'-二辛基-3,3,3',3'-四甲基吲哚羰花青-perchlorate（Dil）灌注来可视化脉络膜血管。通过荧光显微镜评估脉络膜血管密度。GK 大鼠的 CT 增加（58.40 ± 1.15 μm 与 50.90 ± 1.58 μm，p < 0.001），脉络膜毛细血管（CC）的血管密度降低（p = 0.045），外视网膜的 Iba1 细胞密度增加（p = 0.003），并且大多数视网膜层的 VEGFR2 免疫反应性增加（p = 0.021 至 0.037）。脉络膜小胶质细胞和周细胞在其分布中表现出极性，脉络膜最内层不受影响。在 GK 大鼠中，这种内层脉络膜中的无细胞间隙更为明显。总之，GK 大鼠的 CT 增加，最内层脉络膜的血管密度降低，视网膜中 VEGFR2 免疫反应性增加，外视网膜中 Iba1 细胞密度增加。
