A Potential Research Target for Scleral Remodeling: Effect of MiR-29a on Scleral Fibroblasts

Abstract

Introduction: The purpose of this study was to determine whether miR-29a regulates cell survival and apoptosis and the expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN), MMP-2, and collagen I in scleral fibroblasts. Methods: We transfected scleral fibroblasts with the miR-29a mimic and inhibitor. The effects of miR-29a on cell proliferation and apoptosis were determined using the CCK-8 assay and flow cytometry, respectively. Quantitative polymerase chain reaction (qPCR) was used to determine whether miR-29a regulates the mRNA levels of PTEN, MMP-2, and collagen I. The protein expression of PTEN, MMP-2, and collagen I was also assessed by western blot analysis. Results: The results of CCK-8 showed that, at 0, 24, 48, and 72 h after transfection, the relative optical density values in the mimic group were 0.233 ± 0.005, 0.380 ± 0.008, 0.650 ± 0.040, and 0.906 ± 0.032, and in the inhibitor group were 0.272 ± 0.011, 0.393 ± 0.029, 0.597 ± 0.059, and 0.950 ± 0.101, respectively. The flow cytometry results showed that the apoptosis rates of each group were as follows: the mimic group (0.043 ± 0.007), the NC group (0.040 ± 0.006), the inhibitor group (0.032 ± 0.003), the inhibitor NC group (0.027 ± 0.010), the lipofectamine group (0.027 ± 0.005), and the blank group (0.031 ± 0.009). The qPCR results indicated that in the mimic group, PTEN (0.795 ± 0.182, p = 0.2783), MMP-2 (0.621 ± 0.105, p = 0.0033), and COL1A1 (0.271 ± 0.100, p = 0.0002) expression decreased, whereas in the inhibitor group, PTEN (1.211 ± 0.100, p = 0.2614), MMP-2 (1.161 ± 0.053, p = 0.1190), and COL1A1 (1.7040 ± 0.093, p = 0.0003) increased. Western blot analysis showed that in the mimic group, the expression of PTEN (0.392 ± 0.039, p < 0.0001), MMP-2 (0.577 ± 0.017, p < 0.0001), and COL1A1 (0.072 ± 0.006, p < 0.0001) protein decreased, whereas in the inhibitor group, PTEN (1.043 ± 0.042, p = 0.9413), MMP-2 (1.397 ± 0.075, p = 0.0002), and COL1A1 (1.935 ± 0.081, p < 0.0001) expression increased. Conclusion: MiR-29a inhibits the expression of PTEN, MMP-2, and collagen I on scleral fibroblasts, which may provide a basis studies in sclera.