Expression of stem cell factor/c‐kit signaling pathway components in diabetic fibrovascular epiretinal membranes

Abstract

Abstract Purpose Stem cell factor (SCF)/c‐kit signaling promotes recruitment of endothelial progenitor cells and contributes to ischemia‐induced new vessel formation. We investigated the expression of the components of this pathway including c‐kit, SCF, granulocyte colony‐stimulating factor (G‐CSF), endothelial nitric oxide synthase (eNOS), and the chemokine receptor CXCR4 in proliferative diabetic retinopathy (PDR) epiretinal membranes. Methods Membranes from 8 patients with active PDR and 12 patients with inactive PDR were studied by immunohistochemistry. Results Blood vessels expressed c‐kit, SCF, G‐CSF, eNOS, and CXCR4 in 18, 15, 19, 20 and 20 out of 20 membranes, respectively. Significant correlations were detected between number of blood vessels expressing CD34 and number of blood vessels expressing SCF (r=0.463; p=0.04), G‐CSF (r=0.87; p<0.001), eNOS (r=0.864; p<0.001), and CXCR4 (r=0.864; p<0.001). Stromal cells expressed c‐kit, SCF, eNOS, and CXCR4 in 19, 15, 20, and 20 membranes, respectively. The numbers of blood vessels expressing CD34 (p=0.005), c‐kit (p=0.03), G‐CSF (p=0.007), eNOS (p=0.001), and CXCR4 (p=0.018), and stromal cells expressing c‐kit (p=0.013), SCF (p<0.001), eNOS (p=0.048), and CXCR4 (p=0.003) were significantly higher in active membranes than in inactive membranes. Conclusion SCF/c‐kit signaling might contribute to neovascularization in PDR.