Next, we compared the protective effects of UV-blocking and non–UV-blocking contact lenses on the UVB-induced effects on protein expression in HLE B-3 cells. The four samples (control, UVB, UVB + UV-blocking contact lens, and UVB + non–UV-blocking contact lens) were pooled and run on each of four 2D gels as a standard. For each protein spot, we determined the ratio of the experimental sample to the pooled sample (control vs. pooled, UVB vs. pooled, UVB + UV-blocking contact lens vs. pooled, and UVB + non–UV-blocking contact lens vs. pooled). Protein spots that changed >1.7-fold in this comparison were considered significant, indicating a 95% confidence interval (that is, 95% of the fold change in protein spots was <1.7). Changes in protein abundance after UVB irradiation were of lower magnitude in samples irradiated through UV-blocking contact lenses. The 3D data sets for a few representative spots are shown in
Figure 3. Mass spectroscopy-based proteomic analyses of these proteins are presented in
Table 3. Protein spot 2422 (β-actin) showed a 2.09-fold increase between the control cells and the UVB-treated cells. This difference decreased to nearly 1, representing no change, when UV-blocking contact lenses were used (control vs. UVB + UV-blocking contact lenses = 1.18) but did not decrease substantially when non–UV-blocking contact lenses were used (C vs. UVB + non–UV-blocking contact lenses = 1.93). The abundance of spot 2580 (G3PDH and annexin A2) and spot 2584 (annexin A2) increased 1.95- and 1.75-fold, respectively, after UVB irradiation. In these cases, only UV-blocking contact lenses protected the cells from these changes, whereas non–UV-blocking contact lens lenses provided no protection (
Table 3). Similarly, spot 3086 (triose phosphate isomerase), spot 4077 (ubiquitin B precursor), and spot 4162 (vimentin, nucleophosmin 1, and β-actin) increased 2.08-, 2.08-, and 1.83-fold, respectively, with UVB treatment. The alterations in spot 4162 (vimentin, nucleophosmin 1, and β-actin) were not protected by non–UV-blocking contact lenses but were somewhat protected by UV-blocking contact lenses. The changes in spot 4077 (ubiquitin B precursor) and spot 3086 (triose phosphate isomerase) were almost completely protected by UV-blocking contact lenses but were not protected by the non–UV-blocking contact lenses. For all proteins, the UV-blocking contact lenses had a greater protective effect than the non–UV-blocking contact lenses. Among the proteins that showed decreased abundance with UVB treatment, spot 1511 (caldesmon 1, ezrin, and zyx protein) decreased 2.01-fold with UVB radiation, and this change was prevented by the UV-blocking contact lenses, whereas no protection was observed with the non–UV-blocking contact lenses. Spot 1529 (lamin A/C transcript variant 1 and other proteins; see
Table 3) decreased 1.7-fold after UVB radiation, and this alteration was completely abrogated by the UV-blocking contact lenses but not by the non–UV-blocking contact lenses. Spot 2284 (eukaryotic translational initiation factor and β-actin) decreased 1.85-fold in the presence of UVB radiation; this change was partially protected by UV-blocking contact lenses but was not protected by non–UV-blocking contact lenses. Although spot 769 (prepro α [1] collagen) decreased 2.86-fold after UVB exposure, the changes in this protein spot were not significantly protected by either lens type, although non–UV-blocking contact lenses protected slightly better protection than did UV-blocking contact lenses.