AIM: To investigate the effect of silencing SIAH1 gene on H₂O₂-induced apoptosis of human lens epithelial cells.

METHODS: The human lens epithelial cell line HLE-B3 was cultured and divided into normal group, H₂O₂ group(cultured with medium containing 400μmol/L H₂O₂)and H₂O₂+siR-SIAH1 group(transfected with SIAH1 interference sequence, followed by cultured with medium containing 400μmol/L H₂O₂)and siR-NC group(transfected with negative control sequence, followed by cultured with medium containing 400μmol/L H₂O₂). The expression of SIAH1 gene in cells was detected by real-time fluorescent quantitative PCR. The apoptosis rate was detected by flow cytometry. The expressions of p38 MAPK, p-p38 MAPK, Bcl-2 and Bax proteins were detected by Western blot.

RESULTS: The relative expression levels of SIAH1 mRNA in the H₂O₂ group, siR-NC group and H₂O₂+siR-SIAH1 group were higher than that in the normal group(P<0.05). The relative expression level of SIAH1 mRNA in H₂O₂+siR-SIAH1 group was lower than those in the H₂O₂ group and siR-NC group(P<0.05). The apoptosis rates in the H₂O₂ group, siR-NC group and H₂O₂+siR-SIAH1 group were higher than that in the normal group(P<0.05). The apoptosis rate in the H₂O₂+siR-SIAH1 group was lower than those in the H₂O₂ group and siR-NC group(P<0.05). The expression levels of p38 MAPK and Bcl-2 proteins in the H₂O₂ group, siR-NC group and H₂O₂+siR-SIAH1 group were lower than those in the normal group, while the expression levels of p-p38 MAPK and Bax proteins were higher than those in the normal group(P<0.05). The expression levels of p38 MAPK and Bcl-2 proteins in the H₂O₂+siR-SIAH1 group were higher than those in the H₂O₂ group and siR-NC group, while the expression levels of p-p38 MAPK and Bax proteins were lower than those in the H₂O₂ group and siR-NC group(P<0.05).

CONCLUSION: Down-regulation the expression of SIAH1 gene could inhibit H₂O₂-induced apoptosis of human lens epithelial cell line HLE-B3, which might be related to inhibition of p38 MAPK signaling pathway activation.