Uncoupling Protein-2 Participates in Cellular Defense against Oxidative Stress in Clonal β-Cells
| Autor: | Frank Skorpen, Kjartan Egeberg, Valdemar Grill, Li-Xin Li, Ingrid Hals Jørgensen |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Cell Survival
medicine.medical_treatment Biophysics Biology medicine.disease_cause Biochemistry Ion Channels Flow cytometry Mitochondrial Proteins Islets of Langerhans medicine Humans Vitamin E Uncoupling Protein 2 MTT assay RNA Messenger Viability assay Molecular Biology chemistry.chemical_classification Reactive oxygen species medicine.diagnostic_test Membrane Transport Proteins Proteins Hydrogen Peroxide Cell Biology Transfection Molecular biology Clone Cells Oxidative Stress Gene Expression Regulation chemistry Toxicity Oxidative stress |
| Zdroj: | Biochemical and Biophysical Research Communications. 282:273-277 |
| ISSN: | 0006-291X |
| DOI: | 10.1006/bbrc.2001.4577 |
| Popis: | The role of uncoupling protein-2 (UCP-2) in beta-cells is presently unclear. We have tested the notion that UCP-2 participates in beta-cell defense against oxidants. Expression of the UCP-2 gene in clonal beta-cells (INS-1) was decreased by 45% after 48 h of culture with vitamin E and selenite. When INS-1 cells were exposed to 200 microM H(2)O(2) for 5 min, the cell viability (MTT assay) decreased to 85 +/- 1, 61 +/- 1, 40 +/- 2, and 39 +/- 2% of control when measured respectively 30 min, 2 h, 6 h, and 16 h after H(2)O(2) exposure. At corresponding time points UCP-2 mRNA levels were 1.01 +/- 0.09, 1.53 +/- 0.15 (P0.05), 1.44 +/- 0.18 (P = 0.06), and 1.12 +/- 0.09 fold of control, i.e., transiently increased. We next tested whether overexpression of UCP-2 could enhance resistance of beta-cells toward H(2)O(2) toxicity. A cotransfection method using EGFP as a suitable marker and a human cDNA UCP-2 construct was used for transient overexpression of UCP-2. Transfected cells expressed the gene about 30-fold more than normal cells. After exposure to H(2)O(2) (200 micrometer, 5 min), the survival of UCP-2 overexpressing cells was measured 30-45 min later by flow cytometry. Survival was 13 +/- 0.05% higher than control (EGFP only) cells, P0.004 for difference. The results indicate that oxidative stress induces UCP-2 expression in beta-cells, and that UCP-2 serves a role in beta-cell defense against oxidative stress. |
| Databáze: | OpenAIRE |
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