Original Article
The Protective Function of PSMB5 Overexpression to Human Lens Epithelial Cells under the Oxidative Environment
Tieying Zhang, Yuxian Zhang, Jing Wang
Published 2023-03-25
Cite as Chin J Optom Ophthalmol Vis Sci, 2023, 25(3): 195-200. DOI: 10.3760/cma.j.cn115909-20220916-00361
Abstract
Objective:To observe the protective function of proteasome β5 subunit (PSMB5) overexpression to the human lens epithelial cells under the oxidative environment.
Methods:Experimental study. Human lens epithelial cells strain of stable overexpression of PSMB5 gene was established as experimental group, and cell strain with empty pcDNA3.1 transfection as control group. Western blot was performed to detect the PSMB5 protein, proteasome β2 (PSMB7) protein, and proteasome β1 (PSMB6) protein expression in the two groups. Artificial polypeptide Suc-Leu-Leu-Val-Tyr-AMC (LLVY), Boc-Bal-Gly-Arg-AMC (VGR), and Z-Leu-Leu-Glu-βNA (LLE) were used separately to detect the viability changes of the PSMB5, PSMB7, and PSMB6 protein in the two group cells. The cell viability and the intracellular carbonylated protein content change were detected after the experimental group cells and control group cells were treated by 40 μmol/L H2O2 Data were analyzed by a paired t test.
Results:The expression of PSMB5 protein was significantly upregulated in PSMB5-transfected human lens epithelial cells than in the control group cells. The expression of subunit PSMB6 and PSMB7 protein were increased dramatically. Additionally, the proteasome activity of these three subunits were statistically higher. After exposure to 40 μmol/L H2O2 for 4 hours, the cell viability were both inhibited in the control group cells and PSMB5 transfected group cells, and the cell viability percentage were 6.99±3.43 % and 72.47±5.56 % respectively in the two groups. But the cell viability was notably higher in the control group cells than that in the PSMB5 transfected group cells, the difference was statistically significant (t=22.41, P<0.001). After 40 μmol/L H2O2 treated for 4 hours, the oxidation protein content in the control group cells and PSMB5 transfected group cells were 2.65±0.44 nmol/mg and 1.63±0.36 nmol/mg respectively, all increased than before treated by H2O2 (0.41±0.10 nmol/mg and 0.45±0.12 nmol/mg). However, the oxidation protein content in the PSMB5 transfected group cells was statistically lower than in the control group cells (t=4.01, P=0.008).
Conclusions:Overexpression of the PSMB5 gene catalytic subunit in human lens epithelial cells can increase the proteasome catalitic activity and cell antioxidative ability with protective effect.
Key words:
proteasome; PSMB5; lens; overexpression; oxidation; protective
Contributor Information
Tieying Zhang
Department of Ophthalmology, Panyu Maternal and Child Care Service Center of Guangzhou, Hexian Memorial Affiliated Hospital of Southern Medical University, Guangzhou 511400, China
Yuxian Zhang
Department of Ophthalmology, Panyu Maternal and Child Care Service Center of Guangzhou, Hexian Memorial Affiliated Hospital of Southern Medical University, Guangzhou 511400, China
Jing Wang
Department of Ophthalmology, Panyu Maternal and Child Care Service Center of Guangzhou, Hexian Memorial Affiliated Hospital of Southern Medical University, Guangzhou 511400, China
