Objective      To determine the expression of αΒ-crystallin in human retinal pigment epithelial cells (RPEC)

and to investigate the effect of αΒ-crystallin on RPEC proliferation in vitro.       Methods       A-RPE19 cells were subcultured and the expression of αΒ-crystallin was detected using immunofluorescence technique. αΒ-crystallin in different concentrations (V/V: 1/10

2

1/10

3

1/10

4

1/10

5

and 1/10

6

) and its antibody were used for treating different groups of cells

and then OD values and cell cycle together with cell apoptosis at different time points were measured by MTT assay and flow cytometry

respectively.       Results        αΒ-crystallin was found to be expressed in the cytoplasm of human RPEC cultured in vitro. There were statistical significance (P0.05) in cell OD values among the three groups at 48 h when the concentration was 1/10

4

-1/10

2

. The proportion of cells at G

1

phase decreased while the proportion of those at S and G

2

phases increased in αΒ-crystallin group as compared with the control group (0-48 h). The proportion of cells at G

1

phase increased while the proportion of those at S and G

2

phases decreased in αΒ-crystallin antibody group as compared with the control group (0-48 h). The ratios of apoptotic cells among the three groups were significantly different at 48 h (P0.05).       Conclusion        Our study verified the expression of αΒ-crystallin in the cytoplasm of human RPEC in vitro

and αΒ-crystallin plays a distinct role in promoting RPEC proliferation.