Chaperone Effects Of Alpha A Crystallin In Naphthalene-Induced Cataract In Cultured Rat Lens

The pathogenesis of cataract is very complicated and multi factors related.As the most important structural protein in lens,crystallin accounts 90%of water-soluble proteins.Crystallin can be divided into two families,αcrystallin andβγcrystallin,αcrystallin is the major part,accounting approximately 65%of lens proteins. Studies have shown thatαcrystallin presents chaperone activity,which is inhibition of protein aggregation and inhibition of enzyme deactivation.Previous studies focus on the chaperone characteristics of the lens proteins themselves,but not much on the cataract process.And naphthalene cataract model is a mature model of cataract in the study of the cataract mechanism.Thus,we studied the chaperone activity ofαA crystallin in the naphthalene-induced cataract model and the prevention effects of aspirin on it.Part OnePurpose:To investigate the chaperone activity ofαA crystallin of naphthalene cataract in vitroMethods:Rat lens were cultured in vitro and divided into two groups(the normal control group and the naphthalene cataract group),αA crystallin was separated and purified by HPLC(High performance Liquid Chromatography).Detect the thermal stability protective activity against bovine LDH(Lactate Dehydrogenenase) to indicate the chaperone effect.Results:Morphologic change of lens cultured with 5×10^-5 mol/L naphthalene was significant,especially after 3 days.αA crystallin's thermal stability protective activity against LDH was 46.25%±0.27 in the normal control group and 25.9%±0.11 in the naphthalene cataract group,P<0.001.Conclusion:Cataract can be induced by naphthalene in cultured rat lens in vitro,the chaperone activity ofαA crystallin decreases.Part TwoPurpose:to investigate the effect of aspirin on the chaperone activity ofαA crystallin in naphthalene induced cataract model in vitro.Methods:Rat lens were cultured in vitro and divided into three groups (the normal control group,the naphthalene cataract group and the aspirin group),αA crystallin was separated and purified by HPLC. Detect the thermal stability protective activity against LDH to indicate the chaperone effect.Results:αA crystallin's thermal stability protective activity against LDH was 28.12%±0.13 in 20ug/ml aspirin group,36.5%±0.16 in 200ug/ml aspirin group,34.1%±0.18 in 2mg/ml aspirin group and 25.9%±0.11 in non aspirin group.There are significant statistic differences between each group under the student' s T test except the one between the non aspirin group and the 20ug/ml aspirin group,which has a P>0.05.Conclusion:Aspirin can inhibits the decrease of chaperone activity ofαA crystallin in naphthalene induced cataract in vitro and the inhibition ability is positive correlated with the concentration of aspirin.