Comparison of expression levels of senescence marker protein 30 in lens epithelial cells among different ages of cataract patients / 中华实验眼科杂志

ABSTRACT

Background Senescence marker protein 30 (SMP30) is a new calcium regulatory protein,which plays anti-oxidation,stable calcium and anti-apoptosis roles in vivo.Researches determined that the expression of SMP30 in human cells gradually decreased as ageing.However,the study on the relationship between SMP30 and age-related cataract is rarely.Objective The aim of this study was to investigate the expression of SMP30 in lens epithelial cells (LECs) of different ages of cataract patients.Methods This study was approved by Ethic Commission of the First Affiliated Hospital of Guangxi Medical University.A non-randomized controlled trail was designed.The samples of the anterior capsular membrane of lens were collected during the cataract surgery from the children group (1-18 years),youth group (19-45 years),mid adult group (46-60 years) and elder group (＞60 years) and 12 pieces of capsular membrane for each group.In addition,12 pieces of lens capsular membrane from normal donors aged 19-45 years were obtained as normal control group.The expression of SMP30 in the samples was detected by indirect immunofluorescence method.The average fluorescent values were calculated as absorbance (A) / area.Results SMP30 was expressed in LECs of different groups with the green fluorescence primarily in the cytoplasm.The mean fluorescence intensity was 0.185±0.020,0.181±0.034,0.207±0.018 and 0.126±0.027 in the children group,youth group,mid adult group and elder group,respectively,which were significantly enhanced than 0.087±0.007 of the normal control group(q=3.96,3.82,4.01,3.55,all at P＜0.01).No significant differences in the expression of SMP30 among the children group,youth group and mid adult group (all at P＞0.05).However,the expression of SMP30 in LECs in the elder group was significantly lower than that in the children group,youth group and mid adult group (q =3.42,3.21,3.80,all at P＜ 0.05).Conclusions Expression of SMP30 in LECs dramatically increases in cataract patients,suggesting that SMP30 may be a protective factor for LECs.But SMP30 contents are lower in age-related cataract patients,which may be one of causes of senior cataract.