Department of Physiology, Biomedical Center, Faculty of Medicine, University of Iceland, Reykjavík, Iceland.
Acta Ophthalmol. 2022 Dec;100(8):911-918. doi: 10.1111/aos.15140. Epub 2022 Mar 29.
Mice carrying pathogenic variants in the microphthalmia transcription factor (Mitf) gene show structural and functional changes in the retina and retinal pigment epithelium. The purpose of this study was to assess the vascular changes in Mitf mice carrying pathogenic variants by determining their retinal vessel diameter.
Mice examined in this study were: B6-Mitf (n = 6), B6-Mitf /Mitf (n = 6) and C57BL/6J wild type mice (n = 6), all 3 months old. Fundus images were taken with a Micron IV camera after intraperitoneal injection of fluorescein salt. Images were adjusted to enhance contrast and a custom written MATLAB program used to extract the mean vascular diameter at a pre-defined distance from the optic disc. The number of vessels, mean diameter and mean total diameter were examined.
The mean diameter of retinal veins in Mitf /Mitf mice was 18.8% larger than in wild type (p = 0.026). No differences in the mean diameter of the retinal arteries were found between the genotypes. Mitf /Mitf mice have 17.2% more retinal arteries (p = 0.026), and 15.6% more retinal veins (p = 0.041) than wild type. A 24.8% increase was observed in the mean combined arterial diameter in mice with the Mitf Mitf compared to wild type mice (p = 0.024). A 38.6% increase was found in the mean combined venular diameter in mice with the Mitf /Mitf pathogenic variation as compared to wild type (p = 0.004). The mean combined retinal venular diameter in the Mitf mice was 17.8% larger than in wild type (p = 0.03).
An increase in vascularization of the retina in Mitf /Mitf mice was found, indicating an increased demand for blood flow to the retina.
携带小眼畸形转录因子（Mitf）基因致病性变异的小鼠表现出视网膜和视网膜色素上皮的结构和功能变化。本研究的目的是通过确定其视网膜血管直径来评估携带致病性变异的 Mitf 小鼠的血管变化。
本研究检查的小鼠为：B6-Mitf（n=6）、B6-Mitf/Mitf（n=6）和 C57BL/6J 野生型小鼠（n=6），均为 3 月龄。在腹腔注射荧光素盐后，使用 Micron IV 相机拍摄眼底图像。对图像进行调整以增强对比度，并使用自定义编写的 MATLAB 程序从视盘预定距离处提取平均血管直径。检查了血管数量、平均直径和总平均直径。
Mitf/Mitf 小鼠的视网膜静脉平均直径比野生型大 18.8%（p=0.026）。基因型之间视网膜动脉的平均直径没有差异。Mitf/Mitf 小鼠的视网膜动脉数量多 17.2%（p=0.026），视网膜静脉数量多 15.6%（p=0.041）。与野生型相比，Mitf/Mitf 小鼠的平均总动脉直径增加了 24.8%（p=0.024）。与野生型相比，Mitf/Mitf 小鼠的平均总静脉直径增加了 38.6%（p=0.004）。与野生型相比，Mitf 小鼠的平均总视网膜静脉直径大 17.8%（p=0.03）。
在 Mitf/Mitf 小鼠中发现视网膜血管生成增加，表明对视网膜血流的需求增加。
