| External factors: | Calorie restricted |
| Aging type: | Prevent |
| Aging characteristic: |
| Category: | Other |
| Phenotype: | Aging |
| Experiment: | SA-β-gal activity assay//Growth curve assay |
| Description: | The growth curves under these conditions for the three cell lines tested, namely IMR-90 (I90-79) (left panel), IMR (I90-26), and WI-38 (AG06814N). Exposure of cultured IMR-90 (I90-79) and WI-38 cells to CR serum induced a significant increase in population doubling levels (PDL) and all three cell lines showed a profound delayed in the onset of senescent growth arrest.When IMR-90 cells grown in the presence of rat sera were analyzed, we found that at PDL 37, the percentage of SA β-gal-positive fibroblasts cultured in DMEM containing 10 % CR serum was reduced more than 8 folds compared to that of cells of the same passage number grown in 10% AL serum . |
| Target gene: | MMP2 |
| R-EF-Target gene: | -- |
| Official symbol(s): | MMP2 |
| Target gene experiment: | Gelatin zymography |
| Target gene description: | When the levels of MMP-2 activity in IMR-90 (PDL 35) fibroblasts grown in medium containing either rat AL or CR serum were analyzed, we found that CR treatment significantly reduced MMP-2 activation . |
| Regulatory pathway: | SIRT1//p53 |
| R-EF-Pathway: | Upregulation//Downregulation |
| Official symbol(s): | SIRT1//TP53 |
| Pathway experiment: | Western blot |
| Pathway description: | The amount of SIRT1 protein found in IMR-90 fibroblasts grown in the presence of CR serum at PDL45 was 15-20% higher than that present in IMR-90 fibroblasts grown with AL-serum at PDL32 . CR rat serum also preserved SIRT1 protein levels in WI-38 fibroblasts when compared to AL rat serum treatment at an intermediate (PDL 37) passage number.We found that CR serum treatment of IMR-90 fibroblasts at PDL43 was accompanied by a decrease in p53 protein levels when compared to AL serum treatment. Specifically, the amount of p53 present in cells cultured in medium with CR serum was 1.6-fold lower than that of the same cells cultured in medium with AL serum. Overexpression of SIRT1 in pSIRT1-transfected IMR-90 (PDL 43) fibroblasts grown in normal medium caused a significant decrease in p53 expression levels . Conversely, the knockdown of SIRT1 in early passage IMR-90 (PDL 29) fibroblasts enhanced p53 expression . |
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