Differential Modulation of Circulating Endothelial Progenitor Cells in Peripheral Blood Monocyte Population of an Early Stage of Streptozotocin-Induced Diabetic Retinopathy

Abstract

Male Wistar rats weighing 220-250 g were used for this study. The animals were individually acclimatized and fed a standard commercial diet and water ad libitum for 7 days. The 12 h light and 12 h dark cycle was followed throughout the study period. All the experiments and Retinal microvascular complications in STZ induced diabetic Wistar rats were validated after 4 months using trypsin digestion assay of retinal vasculature, histological analysis of retina, glial fibrillary acidic protein (GFAP) immunostaining. Subsequently, circulating EPCs were quantified in PBMCs from diabetes induced rats after 4 months using markers such as CD-34, CD-31, CD-146, VE-Cadherin and Flk-1 by flow cytometry. Results: Pericyte loss, acellular capillaries, retinal layer thickness, microglial activation and increased nitric oxide (NO) levels were observed after 4 months of diabetes induction. Whereas the EPC markers. While the EPC markers such as CD-34, CD-31, VE-Cadherin were decreased, the Flk-1+ve cells were up-regulated in the endogenous EPC pool. Conclusion: The quantity of EPCs is modulated in diabetes which may provide an insight into the use of EPCs as a biomarker for the progression of diabetes induced microvascular complication.