Abstract
Purpose :
Inflammation plays an important role in the pathogenesis of diabetic retinopathy. By examining the transcriptome profile and molecular signaling pathway analysis of human retinal endothelial cells (HREC) treated with advanced glycation end products, we have previously shown that the chemokine CXCL1 gene was significantly up-regulated. The purpose of the present study is to determine the effect of CXCL1 and its contribution to the increased vascular permeability and disruption of tight-junctions in retinal vessels in DR.
Methods :
Recombinant CXCL1 (100 ng/eye) or sterile water (vehicle) was injected intravitreally into the eyes of C57bl/6 mice (n=5) followed by FACS analysis of immune cell infiltration in the retinas. Next, qPCR analysis was used to determine mRNA expression of key proteases and chemokines. Western Blot analysis was used to evaluate the expression of albumin and VE-cadherin. CXCL1 levels in retinas of streptozotocin induced diabetic mice b(two months duration) was measured by qPCR. ELISA was used to measure CXCL1 levels in serum samples of human diabetic retinopathy patients.
Results :
Recombinant CXCL1 injected intravitreally caused significant increase in the infiltration of immune cells: two fold increase of neutrophils and 3-fold increase in monocytes. Importantly, qPCR analysis of retinas revealed increased mRNA expression of CCL2 (4-fold), MMP12 (3-fold) and Cathepsin L (2-fold). Western Blot analysis confirmed that CXCL1 caused a significant increase in retinal vessel permeability, which correlates with increased albumin and decreased VE-cadherin expression. CXCL1 expression was significantly increased in the retinas from diabetic mice. Also, CXCL1 level was significantly increased in the serum samples of diabetic retinopathy patients compared to non-diabetic subjects (p=0.001).
Conclusions :
In this study we have shown the role of the chemokine CXCL1 in alteration of blood retinal barrier in diabetic retinopathy, and thus as a potential novel therapeutic target.
This is a 2021 ARVO Annual Meeting abstract.