Mesenchymal stem cell-derived exosomes inhibit the VEGF-A expression in human retinal vascular endothelial cells induced by high glucose
Authors:   Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300070, China; Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin 300020, China; Ophthalmic Center of Xinjiang Production and Construction Corps Hospital, Urumqi 830002, Xinjiang Uygur Autonomous Region, China, He Guang-Hui , Dong Meng ,   Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300070, China; Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin 300020, China, Chen Song ,   Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300070, China; Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin 300020, China, Wang Yu-Chuan ,   Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300070, China; Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin 300020, China, Gao Xiang ,   Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin 300020, China; Medical College of NanKai University, Tianjin 300000, China, Wu Bin ,   Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300070, China; Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin 300020, China, Wang Jian ,   Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300070, China; Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin 300020, China, Wang Jun-Hua ,   Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300070, China; Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin 300020, China
Published: November 2021

AIM: To determine the effect of exosomes derived from human umbilical cord blood mesenchymal stem cells (hUCMSCs) on the expression of vascular endothelial growth factor A (VEGF-A) in human retinal vascular endothelial cells (HRECs).
METHODS: Exosomes were isolated from hUCMSCs using cryogenic ultracentrifugation and characterized by transmission electron microscopy, Western blotting and nanoparticle tracking analysis. HRECs were randomly divided into a normal control group (group A), a high glucose model group (group B), a high glucose group with 25 μg/mL (group C), 50 μg/mL (group D), and 100 μg/mL exosomes (group E). Twenty-four hours after coculture, the cell proliferation rate was detected using flow cytometry, and the VEGF-A level was detected using immunofluorescence. After coculture 8, 16, and 24h, the expression levels of VEGF-A in each group were detected using PCR and Western blots.
RESULTS: The characteristic morphology (membrane structured vesicles) and size (diameter between 50 and 200 nm) were observed under transmission electron microscopy. The average diameter of 122.7 nm was discovered by nanoparticle tracking analysis (NTA). The exosomal markers CD9, CD63, and HSP70 were strongly detected. The proliferation rate of the cells in group B increased after 24h of coculture. Immunofluorescence analyses revealed that the upregulation of VEGF-A expression in HRECs stimulated by high glucose could be downregulated by cocultured hUCMSC-derived exosomes (F=39.03, P<0.01). The upregulation of VEGF-A protein (group C: F=7.96; group D: F=17.29; group E: F=11.89; 8h: F=9.45; 16h: F=12.86; 24h: F=42.28, P<0.05) and mRNA (group C: F=4.137; group D: F=13.64; group E: F=22.19; 8h: F=7.253; 16h: F=16.98; 24h: F=22.62, P<0.05) in HRECs stimulated by high glucose was downregulated by cocultured hUCMSC-derived exosomes (P<0.05).
CONCLUSION: hUCMSC-derived exosomes downregulate VEGF-A expression in HRECs stimulated by high glucose in time and concentration dependent manner.