In vivo dynamical monitoring of rat bone marrow-derived cells participating in choroidal neovascularization under hyperglycemia / 中华实验眼科杂志

ABSTRACT

Background Our previous study demonstrated that hyperglycemia aggravate the choroidal neovascularization (CNV) by promoting the chemotaxis process of bone marrow-derived cells (BMCs).Bioluminescence imaging (BLI) can dynamically monitor CNV in vivo.However,how diabetes mellitus (DM)participate in CNV is still in research.Objective This study was to dynamically observe the influence of BMCs to CNV under hyperglycaemia by using BLI combined with histopathology.Methods BMCs from luciferase-green fluorescent protein (Fluc-GFP) double transgenic mice were injected to adult wild type C57BL/6J mice (nine mice per group) via caudal vein to create the chimera models with a chimerism degree higher than 85％,and the chimeric mice were randomized into the control group and DM group based on randomized number table.Streptozotocin [60 mg/(kg · d)] was intraperitoneally injected daily for 5 days to establish the DM models in the chimeric mice of the DM group.CNV was induced in the chimeric mice of both control group and DM group with 532 nm laser photocoagulation.BLI signal of BMCsFluc+GFP+ was in vivo examined by IVIS Kinetics system 1,3,5,7,14,21 and 28 days after CNV modeling.At the seventh day after laser,part of mice were sacrificed,and choroidal and retinal sections were prepared for histopathological examination.The length and thickness of CNV were compared between the control group and DM group.The use and care of experimental followed Statement of ARVO.Results The chimerism degree of the chimeric mice was (88.85 ± 2.46) ％ 28 days after BMCs transplantation,and the blood glucose concentration in the DM group was (17.88±0.86)mmol/L.Histopathological examination revealed that CNV broke through the Bruch membrane toward subretinas.The length of the CNV was (338.67±33.17) μm in the DM group and (180.33±24.68)μm in the control group,showing a significant difference between the two groups (t =8.943,P＜0.05).However,no significant difference was seen in the CNV thickness between the two groups (t =1.790,P＞0.05).Light signals appeared 1 day and reach strongest 7 days after CNV modeling in both groups.The Light signals were stronger in the DM group than those in the control group on 5,7,14 and 21 days after CNV modeling (t =3.411,5.594,5.067,2.663,all at P＜0.05).Conclusions Hyperglycemia can promote more BMCs to participate in the pathogenesis and aggravation of CNV.The behavior of BMCs in CNV can be evaluated using BLI in vivo.