ABSTRACT
Objective To investigate the expression of microRNA-34a (miR-34a) and silent information regulator 1 (SIRT1) in human lens epithelial cells under H2O2-induced oxidative stress.Methods Different concentrations of H2O2 (0 μmol · L-1,100 μ mol· L-1,200 μmol · L-1,300 μmol · L-1,and 400 μmol · L-1) were used to stimulate SRA01/04 cells for 24 hours.Cell viability was measured using cell counting kit-8 (CCK-8) assay.Cell apoptosis was detected by flow cytometry.Expression levels of miR-34a/SIRT1 were measured by RT-PCR.Results CCK-8 assay showed that a certain concentration range of H2O2 had a proliferation inhibition on SRA01/04 cells.There was a dose response relationship between 100 μmol · L-1 and 400 μmol · L-1.Compared with 0 μmol · L-1 H2O2 group,the difference was statistically significant (all P ＜ 0.01).According to flow cytometry results,apoptotic rate of SRA01/04 cells in control group and H2O2(100-300 μmol · L-1) groups were (6.1 ± 1.2)％,(26.3 ± 1.8)％,(32.5 ± 2.2) ％,and (64.7 ± 5.3) ％.Compared with 0 μmol · L-1 H2 O2 group,the differences were statistically significant (all P ＜ 0.01).RT-PCR test results showed that the expression of miR-34a increased significantly in a dose-dependent manner after the SRA01/04 cells treated with different concentrations of H2O2,while SIRT1 expression level was decreased,there were significant differences compared with control group (all P ＜ 0.001).Conclusion There is a significantly increase of miR-34a and decrease of SIRT1 in human lens epithelial cells under the oxidative stress of a certain concentration of H2O2.Down-regulated expression of miR-34a can increase the survival rate of human lens epithelial cells under H2O2-induced oxidative stress.
ABSTRACT
AIM: To construct the prokaryotic expression system containing protein transduction domain (PTD) with heat shock protein 27 (HSP27) in order to prepare and purify the recombinant protein , and to verify whether the recombinant protein PTD-HSP27 has the ability to penetrate the human lens epithelial cell ( HLEC) membrane and the rabbit cornea.METHODS:The plasmid pKYB-PTD-HSPB1-6His was constructed by the technique of overlap extension PCR.The plasmid was transformed and PTD-HSP27 was purified through nickel affinity chromatography column and identi-fied by Western blotting.PTD-HSP27-6His was labeled with the fluorescein isothiocyanate (FITC).The penetrating ability of PTD-HSP27 into HLECs and rabbit cornea was tested .RESULTS:The recombinant PTD-HSP27 plasmid was success-fully cloned and effectively expressed .The correctness of the recombinant protein PTD-HSP27 was demonstrated .Fluores-cence microscopic examination showed that PTD-HSP27-FITC was internalized by HLECs .Fluorescent labeled PTD-HSP27 was then observed in the rabbit aqueous humor .CONCLUSION:The recombined gene PTD-HSPB1 was constructed by o-verlap extension PCR technique and the PTD-HSP27 fusion protein was prepared and purified by nickel affinity chromatog-raphy column.Using the technique of PTD-fusion protein, HSP27 was transduced into HLECs and passed through the cor-nea .
ABSTRACT
Background Corneal blindness is one of the major blinding eye diseases in China.With the development and progress of tissue engineering technology,tissue-engineered corneas offers a new approach to the treatment of corneal diseases.To select and cultivate ideal seed cells is a foundation of construction of tissueengineered corneas.Objective This study was to evaluate the efficiency of stripe off the Descemet membrane with endothelium plus enzymic digestion in the isolation of corneal endothelial cells and analyze the bionomics of rabbit corneal endothelial cells (CECs) in vitro.Methods Descemet membrane was stripped from fresh cornea of New Zealand rabbit under the dissection microscope.Descemet membrane with endothelium was incubated in trypsin and EDTA solution at 37 ℃ and then purified for CECs subculture in vitro.The morphology of the cultured cells was observed under the inverted microscope and marked by CM-Dil dye solution.Then the shape of the cells was observed by hematoxylin and eosin staining and the cells were identified for the expression of neuron specific enolase (NSE) using immunochemistry.The viability of the cells were evaluated by trypan blue staining.The surface structure of the cells were examined under the scanning electron microscope.Intercellular zonula occludens-1 (ZO-1) was identified by immunofluorecsence staining.Results A large number of purified CECs were obtained from Descemet membrane with endothelium through enzymic digestion.Cultured cells grew well and formed monolayer 5-7 days later with the cobblestone stone-like arrangement.The survival rate of the cells was 95％.CECs presented with the red annular fluorescence for CM-Dil with the labeling rate ＞90％.NSE was positively expressed in the cytoplasm.Polygon CECs were seen by hematoxylin and eosin staining and showed the brown staining.Abundant microvilli on the cellular surface and interconnected foot process were seen under the scanning electron microscope.ZO-1 showed the green fluorescence.Conclusions The method of striping off the corneal Descemet membrane with endothelium plus enzymic digestion can obtain abundant CECs.Cultured cells have good biological properties.This study may offer a feasible application in the engineering of corneal transplant membrane.