Fig 2: Detection of CXCL16, ADAM10, and ADAM17 in vitreous fluid. The expression of CXCL16, ADAM10, and ADAM17 in equal volumes (15 μl) of vitreous fluid samples from patients with proliferative diabetic retinopathy (PDR) (n=8) and from non-diabetic patients with rhegmatogenous retinal detachment (RD) (n=8) was determined by Western blot analysis. Immunoreactive proteoforms are indicated in kilodaltons (kDa) on the basis of a size standard preparation. Representative sets of samples are shown.

Fig 3: CXCL16 induces vascular endothelial growth factor (VEGF) expression and activates ERK1/2 and NF-κB pathways in Müller cells. Müller cells were left untreated or treated with CXCL16 for 24 h. Levels of VEGF were quantified in the culture media by enzyme-linked immunosorbent assay (ELISA). Protein expression of phospho-ERK1/2 and the p65 subunit of NF-κB in the cell lysates was determined by Western blot analysis (representative Western blots are depicted on top of the graphs). The box plots (median and interquartile range) show results from three different experiments performed in triplicate. (*p < 0.05; Mann-Whitney test).

Fig 4: The proinflammatory cytokine tumor necrosis factor-alpha (TNF-α) induces the expression of CXCL16 and ADAM17 in Müller cells. Müller cells were left untreated or treated with TNF-α (50 ng/ml) for 24 h. Levels of CXCL16 were quantified in the culture media by ELISA. Protein expression of CXCL16, CXCR6, ADAM10, and ADAM17 in cell lysates was determined by Western blot analysis. Results are expressed as median (interquartile range) from three different experiments performed in triplicate. (*p < 0.05; Mann-Whitney test).

Fig 5: Human retinal microvascular endothelial cells (HRMECs) express CXCL16, CXCR6, CX3CL1, and CX3CR1. HRMECs were left untreated or treated with interleukin-1 beta (IL-1β) (50 ng/ml) or tumor necrosis factor-alpha (TNF-α) (50 ng/ml) for 24 h. Protein expression of CXCL16 (A), CXCR6 (B), CX3CL1 (C), and CX3CR1 (D) in cell lysates was determined by Western blot analysis (representative Western blots are depicted on top of the graphs). The same loading control (β-actin) was used for quantitation of the relative band intensity of both CXCL16 and CXCR6. Levels of CX3CL1 were quantified in the culture media by ELISA (E). The box plots (median and interquartile range) show results from three different experiments performed in triplicate. Kruskal-Wallis test and Mann-Whitney tests were used for comparisons between three groups and two groups, respectively. *P < 0.05 compared with values obtained from untreated cells. #p < 0.05 compared with IL-1β-treated cells.