Overexpression of H Ferritin and Up-regulation of Iron Regulatory Protein Genes during Differentiation of 3T3-L1 Pre-adipocytes
| Autor: | Guido Mele, Alfredo Colonna, Concetta Pietropaolo, Alfredo Ruffo, Gaetano Ricciardelli, Michela Festa |
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| Přispěvatelé: | Festa, M., Ricciardelli, G., Mele, G., Pietropaolo, Concetta, Ruffo, A., Colonna, A., Festa, Michelina, Ruffo, Alfredo, Colonna, Alfredo |
| Rok vydání: | 2000 |
| Předmět: |
Iron-Sulfur Proteins
Protein subunit Cellular differentiation Adipose tissue Biology Biochemistry Mice Adipocytes Animals Iron Regulatory Protein 1 RNA Messenger Northern blot Molecular Biology Regulation of gene expression Iron-Regulatory Proteins RNA-Binding Proteins Cell Differentiation 3T3-L1 3T3 Cells Cell Biology Blotting Northern Molecular biology Up-Regulation Blot Ferritin Ferritins biology.protein Cytokines Electrophoresis Polyacrylamide Gel |
| Zdroj: | Journal of Biological Chemistry. 275:36708-36712 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m004988200 |
| Popis: | The role of iron-dependent oxidative metabolism in protecting the oxidable substrates contained in mature adipocytes is still unclear. Because differentiation increases ferritin formation in several cell types, thereby leading to an accumulation of H-rich isoferritins, we investigated whether differentiation affects iron metabolism in 3T3-L1 pre-adipocytes. To this aim, we evaluated the expression of the genes coding for the H and L ferritin subunits and for cytoplasmic iron regulatory protein (IRP) during the differentiation of 3T3-L1 cells in adipocytes induced by the addition of isobutylmethylxanthine, insulin, and dexamethasone. Differentiation enhanced ferritin formation and caused overexpression of the H subunit, thus altering the H/L subunit ratio. Northern blot analysis showed increased levels of H subunit mRNA. A gel retardation assay of cytoplasmic extract from differentiated cells, using an iron-responsive element as a probe, revealed enhanced an RNA binding capacity of IRP1, which correlated with the increase of IRP1 mRNA. The observed correlation between differentiation and iron metabolism in adipocytes suggests that an accumulation of H-rich isoferritin may limit the toxicity of iron in adipose tissue, thus exerting an antioxidant function. |
| Databáze: | OpenAIRE |
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