Abstract
Purpose:
Interleukin 10 (IL-10) has been shown to suppress the chronic inflammatory diseases. Our previous study has shown that reduced numbers and impaired function of circulating endothelial progenitor cells (EPCs) contributed to the pathogenesis of DR. In this study we investigated the roles of IL-10 in proliferation , apoptosis and migration of EPCs, the function of IL-10-modified EPCs in progression of non-proliferative diabetic retinopathy (NPDR) and the roles of IL-10-modified EPCs in suppressing the NF-κB pathway and inflammatory environment.
Methods:
We firstly established EPC-GFP-IL-10 stable cell line, and used the cell cycle assay, Annexin V/PI staining and Transwell assay to determine the functions of IL-10 in EPCs. We used Western blot to test the activation of STAT3 pathway in EPCs. Furthermore, we performed intravitreal injection of EPC-GFP-IL-10 cells into the streptozotocin-induced diabetic rats. We used in situ hybridization to test the distribution of EPC-GFP-IL-10 cells and HE staining, Evans blue assay, and Immunofluorescence to test the progression of NPDR. We performed RT-PCR and Western blot to assess the makers of DR. In addition, we performed Western blot, Immunohistochemistry, and Elisa to assess the activation of NF-κB pathway.
Results:
IL-10 increased the proliferation and migration of EPCs, and decreased the apoptosis of EPCs. IL-10 also activated the STAT3 pathway in EPCs. Furthermore, EPC-GFP-IL-10 cells delayed the damage of blood-retinal barrier and down-regulated the expression of DR makers in retina tissues. In addition, EPC-GFP-IL-10 cells decreased the expression of p65, p50 IL-6, IL-8 and TNF-α in retina tissues.
Conclusions:
IL-10-modified EPCs suppress the progression of NPDR by inhibition of NF-κB pathway, and establish a rationale for developing IL-10 as a potential therapeutic agent to treat NPDR.
Keywords: 554 immunohistochemistry •
688 retina •
449 cell survival