Are VEGF and SCUBE1 gene expressions increased in diabetic retinopathy?

Abstract

Abstract Objectives In the current study, we synergistically evaluated vascular endothelial growth factor (VEGF) gene expression levels and signal peptide-CUB-EGF domain-containing protein 1 (SCUBE1) gene expression levels in diabetic patients without retinopathy, non-proliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR). Methods 94 blood samples from 26 healthy controls, 29 non-DR, 22 NPDR, and 17 PDR patients were collected in sterile EDTA tubes. Total RNA was obtained from these samples without waiting and then converted to cDNA. The expression levels of the VEGF and SCUBE1 genes were determined by quantitative real-time polymerase chain reaction (qPCR). Results SCUBE1 gene expression levels were 2.15 (p=0.015), 1.75 (p=0.799), 2.37 (p=0.037) times higher, and VEGF gene expression levels were 1.71 (p=0.023), 1.75 (p=0.012), 1.85 (p=0.031) times higher in the non-DR, NPDR, and PDR groups compared to the control group, respectively. VEGF gene expression levels were significantly higher in participants with HbA1c levels ≥5.7% compared to those with <5.7. SCUBE1 and VEGF gene expression levels were significantly higher in participants with fasting plasma glucose (FPG) levels ≥126 mg/dL than those with <126 mg/dL. Conclusions As a result, SCUBE1 gene expression levels are higher than VEGF gene expression levels, especially in the PDR group. Therefore, SCUBE1 may contribute to the pathology of DR just like VEGF by generating angiogenesis. However, we believe there is a need for experimental animal model studies with DR examining SCUBE1 gene expression levels in tissue samples.