ABSTRACT
Background Protein kinase B (Akt) is the center of multiple cellular signaling pathways,and it participates in the regulation of cell function,such as proliferation,migration,and metabolism of cells.Phosphoinositide 3-kinase (PI3K) promotes activation of Akt and therefore triggers many signal pathways.PI3K inhibitor can silent Akt,but whether it can affect the biological behavior of lens epithelial cells (LECs) during the posterior capsular opacity (PCO) is worthy of investigation.Objective This study was to explore the effect of LY294002,a PI3K inhibitor,on Akt activation in human LECs.Methods Human LECs strain,HLEC-B3 cells,were cultured and passaged.The cells were incubated to 96-well plate for 24 hours,then LY294002 was added with the final concentration at 0,10,20,30,40,50,60,70,80 μmol/L,respectively.After incubation for 24 hours,cell counting kit-8 (CCK-8) was used to detect the inhibitory rate of cell proliferation.Transforming growth factor-β2 (TGF-β2) of 10 μg/L was added in the medium of cells as TGF-β2 group,TGF-β2 + LY294002 (20 μmol/L) was used to coculture the other group of cells,and the cells without TGF-β2 and LY294002 served as the control group.Phosphorylation of Akt (p-Akt) in the cells was detected by laser scan confocal immunofluorescence microscope.The expression level of p-Akt was evaluated using Western blot.Results CCK-8 assay showed that the A value of the cells was gradually reduced with the increase of LY294002 concentration (Fgroup =9.72,P =0.00),but the A value was significant raised along with the lapse of time (Ftime =1737.54,P=0.00).Confocal immunofluorescence revealed that a little of p-Akt was expressed in the control cells.After induced by TGF-β2,lots of red fluorescence of p-Akt was seen in cells around the cell membranes.But in the TGF-β2+LY294002 co-culture cells,the fluorescence of Akt was much weaker.Western blot showed that the expression level of p-Akt was 0.91±0.08,1.48±0.13 and 0.95±0.19 in the control group,TGF-β2 group and TGF-β2 +LY294002 group,respectively,with a significant difference among the three groups (F =15.04,P =0.00).Conclusions LY294002 can inhibit the activation of Akt induced by TGF-β2.LY294002 may have utility in the prevention and treatment of PCO.
ABSTRACT
Background The pathogenesis of age-related cataract is associated with the apoptosis of lens epithelial cells (LECs) caused by oxidative stress.Previous studies showed that intracellular focal adhesion kinase (FAK) pathway can be activated by H2O2 in vitro,which induced apoptosis of cells.To investigate the effect of oxidative on FAK expression in LECs is one of important studies in the prevention of age-related cataract.Objective This study was to investigate the expression and function of FAK in human LECs treated by H2O2.Methods Human LECs strain (HLECs-B3) were cultured in vitro in the low glucose DMEM with 10％ fetal bovine serum.Different concentrations (0,30,50,70,100,300,500,700,1000 μmol/L) of H2O2 were added into the culture medium for 24 hours.The survival rate of the cells was detected by Cell Counting Kit-8 (CCK-8) assay.Cell morphology as well as the expression and distribution of FAK in the cells were observed by immunofluorescent staining under the laser confocal microscope.Apoptosis was observed by hoechst33258 staining,and Western blot assay was used to quantitatively detect the expression and phosphorylation of FAK.Results The survival rate of the cells was (1.00±0.03) ％,(1.24±0.03)％,(1.36±0.24) ％,(0.93±0.02)％,(1.75±0.19)％,(1.37±0.18) ％,(0.64±0.01)％,(0.59±0.11)％,(0.14±0.05)％ in 0,30,50,70,100,300,500,700,1000 μmol/L H2O2 groups,with a significant difference among them (F =95.30,P =0.00).The survival rates of the cells in the below 300 μmol/L H2O2 groups were significantly higher than those in the 0 μmol/L H2O2 group,and survival rates of the cells in the above 500 μmol/L H2O2 groups were significantly lower than those in the 0 μmol/L H2O2 group(all at P＜0.05).After H2 O2 treatment for 24 hours,HLECs-B3 cells transformed from polygon shape to spindle shape and extended pseudopodiums,meanwhile the green fluorescence for FAK exhibited in the cytoplasm.Cell apoptosis was found in the 1000 μ mol/L H2O2 group.Western blot assay revealed that the expressing levels (grey scale) were significantly different among the various groups (F=28.08,P=0.00),and FAK expressing levels in the below 300 μmol/L H2O2 groups were significantly higher than those of the 0 μmol/L H2O2 group; while the expressing levels in the above 500 μmol/L H2O2 groups were lower than those of the control 0 μmol/L H202 group (all at P＜0.05).After treated by different concentrations of H2O2,the phosphorylation level of intracellular FAK (p-FAK) was significantly higher in 3 hours group than that in 30 minutes group (all at P＜0.05).Conclusions H2 O2 can affect the survival,proliferation and morphology of human LECs by activating the intracellular FAK pathway,indicating that FAK may play roles in the regulation process of cell biological behavior.
ABSTRACT
Background The pathogenesis and development of cataract is associated with oxidative stress-induced apoptosis of human lens epithelial cells(LECs).BH3-only protein is a factor that can initiate apoptosis,and thus the apoptotic process is probably related to the activation of the c-Jun N-terminal kinase(JNK).However,the relationship between oxidative stress-induced apoptosis of human LECs and the JNK pathway remains to be illuminated.Objective This study was to investigate the effects of the JNK/c-Jun pathway and its target gene,Bim (Bcl-2 interacting mediator of cell death)and PU M A(p53 up-regulated modulator of apoptosis),on oxidative stressinduced apoptosis of human LECs.Methods The human LECs cell line(HLEC-B3)was cultured and passaged in DMEM with 10％ fetal bovine serum in vitro.Confluent cells were incubated in 24 well plates and divided into 4 groups.Hydrogen peroxide(H2O2)(50 μmol/L)was used to treat the cells for 4,8 or 12 hours,and cells without H2O2 treatment served as the control group.Apoptosis was detected using Hoechst 33258 staining and quantified by counting the number of cells with pyknotic nuclei.In addition,confluent cells were seeded in 6 well plates,and Western blot and RT-PCR were used to detect the expression of the caspase-3,c-Jun,Bim and PUMA proteins and their mRNA in HLEC-B3,respectively.The JNK/c-Jun pathway inhibitors,CEP11004 or SP600125,were added into cultured media with H2O2,and cells treated with DMSO or H2O2 only served as negative and positive control groups.The expression of the p-JNK,JNK,p-c-Jun,c-Jun,Bim,PUMA proteins was detected by Western blot and apoptosis was assayed using Hoechst 33258 staining.200 pmoL/L of Bim or PUMA small interference RNA(siBim or siPUMA)fragments were transfected into the cells for 24 hours,respectively,and H2O2 was then used to treat the cells for 8 hours.The expression of the Bim and PUMA protein and their mRNA in the cells was detected by Western blot and RT-PCR,respectively.Results After H2O2 treatment in HLEC-B3 cells for 4,8,or 12 hours,the rates of apoptosis were 4.30％±1.15％,27.08％±0.74％ and 46.59％±0.91％,showing a significant difference among them (F=1909.433,P=0.000),and those of the 4,8,12 hour groups were significantly increased in comparison to the control group(P =0.049,0.000,0.000).Compared to untreated cells,the levels of expression of the JNK,Bim,PUMA proteins and their mRNA in HLEC-B3 cells were significantly elevated.After the addition of CEP11004 or SP600125,the expression of these protein and mRNA in HLEC-B3 cells in the presence of H2O2 was significantly weaker than that in the DMSO control group(P =0.000,0.000).After the tranfection of siBim or siPUMA,the apoptosis rates of the H2O2 treated groups were significantly higher than those in the Bim-/-or PIMA-/-group (P＜0.05).Conclusions H2O2 can activate the JNK/c-Jun pathway and up-regulate the expression of its target genes Bim and PUMA in human LECs in a time-dependent manner.Inhibiting the JNK/c-Jun pathway and interfering with the expression of Bim and PUMA can protect human LECs against oxidative stress-induced apoptosis.
ABSTRACT
Background Surgical induced astigmatism induced by a 5.5mm of superior scleral tunnel incision is a key cause of influencing vision outcome in the high myopic eyes after implantation of Artisan phakic intraocular lens(IOL).Objective This study was to evaluate the surgical induced astigmatism through a 5.5mm superior scleral tunnel incision during the implantation of Artisan phakic IOL.Methods This was a case observational study.The clinical data of 202 eyes of 111 patients with Artisan IOL implantation for high myopia from October 2004 through October 2008 was collected.The patients were followed-up for 12 months.The uncorrected visual acuity(UCVA),best spectacle-corrected visual acuity(BCVA),spherical equivalent(SE),cylinder equivalent(CE) and cylinder axis were examined before surgery and postoperative 1,3,6,12 months.The patients were divided into with rule group and against rule group according to the cylinder axis.Surgery-induced astigmatism value was calculated using Holladay vector analysis formula.This clinical trial was approved by the Ethics Committee of Guangdong General Hospital.Written informed consent was obtained from each patient prior to the surgery.Results The UCVA of 195 eyes(94.1%) was 0.5 or better in postoperative 12 months,and that of 172 eyes(85.1%) showed the improvement of BCVA during the follow-up duration.The mean CE values were reduced in 1,3,6,12 months after surgery in comparison with before surgery(t=-4.30,P=0.00;t=-2.27,P=0.01;t=-2.04,P=0.04;t=-2.79,P=0.01).Vector analysis of total surgically induced astigmatism revealed that the mean incision-induced astigmatism value was +1.94D,+2.26D,+2.29D,+2.25D at 171°,170°,181°,175° in 1,3,6,12 months after surgery.The surgery-induced astigmatism was(+1.97±1.84)D,(+2.25±1.75)D,(+2.27±1.76)D,(+2.24±1.75)D in with rule group at postoperative 1,3,6,12 months respectively;while those in against rule group was(+1.75±1.88)D,(+2.35±1.74)D,(+2.38±1.76)D,(+2.34±1.74)D respectively.No significant differences were found between the two groups(t=0.54,-0.29,-0.27,-0.29;P=0.59,0.78,0.79,0.78).Conclusion Implantation of Artisan IOL is an effective approach for correction of high myopia.A 5.5mm superior scleral tunnel incision in operation induces a +2.25D astigmatism at 175° meridian.
ABSTRACT
Background Some aboard studies showed that polyatomic pathway play an important role in the microsvasculopathy of type 2 diabetes,and sorbitol dehydrogenase (SDH) gene is involved in the pathogenesis of diabetic retinopathy(DR).There is no relevant research at home up to now.Objective This study was to investigate the correlation of sorbitol dehydrogenase (SDH) G-888C gene polymorphism with diabetic retinopathy (DR) in type 2 diabetes mellitus.Methods The SDH genotypes were determined by polymerase chain reactionreaction fragment length polymorphism (PCR-RFLP) in 187 patients with diabetes and 123 normal contrels.Patients were divided into two groups depending on the presence or absence of DR(DR:n=118;NDR:n=69).The frequencies of SDH genotype and allele were assayed and compared among these groups.This study was approved by Ethic Committee of Guangdong General Hospital.Written informed consent was obtained from each individual prior to any relevant medical procedure.Results The disease course in the DR group was significantly longer than that in NDR group(t=2.070,P=0.042),and other clinical features in both groups were non-significant (all P>0.05).The genotype frequencies in the DR group,NDR group and normal control group were 24.6%,8.7% and 8.1%,respectively,and frequencies of the G allele were 42.4%,25.4% and 29.7%,showing statistically significant differences among these three groups.The GG genotype and G allele frequencies were significantly higher in the DR group than those in the NDR group and normal control group (GG:P=0.007,P=0.001;G:P=0.001,P=0.004).There were no significant differences in the frequencies of the GG genotype and G allele between the NDB group and normal control group ( P>0. 05) as well as the proliferative DR group and non-proliferative DR group (P>0.05).Conclusion SDH G-888C gene polymorphism is associated with the development of diabetic retinopathy in southern Chinese.