Background Plasma membrane calcium ATPase 3 (PMCA3) participates in the regulation of Ca2+ level in lens epithelial cells (LECs),which may be associated with the pathogenesis of cataract.It has been proved that ultraviolet B (UVB) is one of causing-factors of cataract.However,the effect of UVB on the expression of PMCA3 in LECs is unclear.Objective This study was to investigate the effects of UVB irradiation on the expression of PMCA3 in human LECs B-3.Methods HLE B-3 cells were cultured and passaged.The cells were exposed to 0,5,10 and 20 mJ · s/cm2 UVB for 0,20,40,80 s,respectively and further cultured for 24,48 and 72 hours.MTT assay was used to detect the cell proliferation rate.JC-1 staining was used to detect the changes of mitochondrial membrane potential (△ψm) in the cells.The intracellular reactive oxygen species (ROS) level was detected by DCFH-DA staining,and cell apoptosis was evaluated using annexin V-FITC/PI staining.In addition,the intracellular calcium ion (Ca2+) concentration in the cells was assayed with Fluo-3/AM staining.The expression levels of PMCA3 mRNA and PMCA protein in the HLE B-3 cells were detected by real-time PCR and Western blot,respectively.Results The survival rates of the cells were significantly reduced with the increase of irradiated intensity of UVB and the lapse of time (Fgroup =72.411,P =0.000 ; Ftime =36.588,P =0.000),and the survival rates of the cells in the 10 mJ · s/cm2 and 20 mJ · s/cm2 UVB for 24 hours were (75.3 ± 2.2) ％ and (48.7 ±4.5) ％,respectively,which were significantly lower than those in the 0 mJ · s/cm2 UVB group ([100.0±0.0] ％) (P=0.001,0.000).The survival rates of the cells in the 5,10,20 mJ · s/cm2 UVB for 48 hours were (84.9± 1.2) ％,(69.3±17.4)％ and (32.8±4.5)％,showing significant declines in comparison with the 0 mJ · s/cm2 UVB group ([100.0±0.0] ％) (P =0.047,0.000,0.000).In 72 hours following 5,10,20 mJ · s/cm2 UVB irradiation,the survival rates of the cells were (55.1 ± 3.0) ％,(42.1 ± 1.9) ％ and (26.1 ±4.7) ％,respectively,with significant differences in comparison with the 0 mJ · s/cm2 UVB group ([100.0 ± 0.0] ％) (P =0.000,0.000,0.000).JC-1staining exhibited the intracellular red fluorescence in the normal cells group.However,in the 5 mJ · s/cm2 UVB group,weak green fluorescence was seen,and the green fluorescence was enhanced in the 10 mJ · s/cm2 and 20 mJ · s/cm2 UVB groups.After irradiated by 5,10 and 20 mJ · s/cm2 UVB,the ROS levels in the cells increased from 0.4％ to 35.8％,51.9％ and 76.7％,respectively.The apoptosis and necrosis rate of the cells was 2.0％ in the 0 mJ · s/cm2 UVB and 4.2％,7.6％,15.1％ in the 5,10,20 mJ · s/cm2 UVB groups,respectively.The Ca2+ level raised by (1.2±0.1) and (1.3±0.1) folds in the 10 and 20 mJ · s/cm2 UVB groups more than that in the 0 mJ · s/cm2 group (P =0.039,0.004).The expression levels of PMCA3 mRNA in the cells were significantly reduced (P=0.001,0.004,0.000),and the expression levels of the PMCA protein were declined in the 5,10 and 20 mJ · s/cm2 UVB groups compared with the 0 mJ · s/cm2 UVB group (P=0.000,0.000,0.001).Conclusions UVB irradiation causes cataract probably through downregulating the expression of PMCA3 in human LECs and inducing apoptosis of LECs in a dose-and time-dependent manner.

AIM:To bring forward a method of determining aflatoxin G_2、G_1、B_2、B_1 in six kinds of traditional Chinese drugs by HPLC.METHODS:After being extracted by 70% methanol,purified by immunoaffinity column,aflatoxins were analysed by HPLC with fluorescence detection.RESULTS:Aflatoxin G_2、B_2 showed a good linear relationship at a range of 1.5-60pg,and Aflatoxin G_1、B_1 at a range of 5-200 pg,r＞0.999 9.The recovery was between 60%-120%.CONCLUSION:The method is simple,accurate and can be used to determine aflatoxin G_2、G_1、B_2、B_1 in Naoliqing Pill,Renshen Yangrong Pill,Rensen Jiapi Pill,Sanqi Tablet,Jinshuibao Capsule and Bailine Capsule.

0.999 9.The recovery was between 60%-120%.CONCLUSION:The method is simple,accurate and can be used to determine aflatoxin G2、G1、B2、B1 in Naoliqing Pill,Renshen Yangrong Pill,Rensen Jiapi Pill,Sanqi Tablet,Jinshuibao Capsule and Bailine Capsule.