Inhibition of apoptosis induced by galactose by c-myc antisense oligodeoxynucleotide in lens epithelial cells

Background Various studies demonstrated that the apoptosis of lens epithelial cells(LECs) is associated with the overexpression of the c-myc gene in LECs induced by galactose.Inhibiting the abnormal expression of the c-myc gene in LECs is an effective approach to mitigate the pathogenesis and development of cataract.Objective The goal of this study is to investigate the inhibitory effects of c-myc antisense oligodeoxynucleotide(c-myc ASODN) on the apoptosis of LECs in the eye with galactose-induced cataract.Methods Galactose-induced cataract models were established by the retrobulbar injection of 0.2 mL of 20% galactose once per day.Lipo-antisense oligodeoxynucleotide(Lipo-ASODN,0.2 mL) was retrobulbarly injected 4 hours after the injection of galactose at one-day intervals.The animals were sacrificed and lenses were obtained to evaluate the apoptosis of LECs and the effect of c-myc ASODN on LECs apoptosis induced by galactose was examined by TUNEL assay after 7,14 and 24 days.The ultrastructural changes of LECs were examined under the transmission electron microscopy(TEM).Results A significant difference in the apoptotic rate of LECs was found among the 7 day,14 day and 24 day groups(F_(7 days)=3 418.495,P＜0.01;F_(14 days)=1137.555,P＜0.01;F_(24 days)=2198.871,P＜0.01).The apoptotic rate of LECs in the galactose group was markedly higher than that in the normal saline solution group 7 days,14 days and 24 days after the experiment(P＜0.01).The apoptotic rate of LECs in the galactose+lipo+ ASODN group significantly declined in comparison to the galactose group after 7 days,14 days and 24 days(P＜0.05).TUNEL assay showed the condensation,breakage and irregularity of the nuclei of apoptotic cells in the galactose group.The destruction of the ultrastructure of the cells and organelles were observed under the transmission electron microscope.Conclusion Galactose induces apoptosis of LECs in cataractogenesis.C-myc ASODN inhibits apoptosis of LECs induced by galactose. Key words: c-myc antisense oligodeoxynucleotide; galactose; cataract; cell apoptosis