Acute activation of AMP-activated protein kinase prevents H2O2-induced premature senescence in primary human keratinocytes

• Published in: PloS one Vol. 7; no. 4; p. e35092
• Main Authors: Ido, Yasuo, Duranton, Albert, Lan, Fan, Cacicedo, Jose M, Chen, Tai C, Breton, Lionel, Ruderman, Neil B
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 13-04-2012; Public Library of Science (PLoS)
• Subjects: Abundance; Activation; Adenoviridae - genetics; Aging; Aminoimidazole Carboxamide - analogs & derivatives; Aminoimidazole Carboxamide - pharmacology; AMP; AMP-activated protein kinase; AMP-Activated Protein Kinases - genetics; AMP-Activated Protein Kinases - metabolism; Aorta; Apoptosis; Apoptosis - drug effects; Atherosclerosis; Biology; Cell cycle; Cell division; Cellular Senescence - drug effects; Cyclin-dependent kinase inhibitor p21; Cyclin-dependent kinases; Diabetes; DNA damage; Embryo fibroblasts; Embryos; Endocrinology; Endothelial cells; Enzyme Activation - drug effects; Epidermal growth factor; Fatty acids; Fibroblasts; Fibrosarcoma; Galactosidase; Gene expression; Genetic Vectors - genetics; Humans; Hydrogen peroxide; Hydrogen Peroxide - pharmacology; Hyperglycemia; Incubation; Inhibitors; Insulin; Keratinocytes; Keratinocytes - drug effects; Keratinocytes - metabolism; Kinases; Liver cancer; Low concentrations; MAP kinase; Medicine; Melanoma; Nitric oxide; Oxidative stress; p53 Protein; Pathogenesis; Pharmacology; Phosphorylation; Proteins; Resveratrol; Ribonucleotides - pharmacology; Senescence; Signal Transduction - drug effects; Signaling; Smooth muscle; Staining; Studies; France; United States > US; Massachusetts
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0035092

We investigated the effects of AMPK on H(2)O(2)-induced premature senescence in primary human keratinocytes. Incubation with 50 µM H(2)O(2) for 2 h resulted in premature senescence with characteristic increases in senescence-associated ß-galactosidase (SA-gal) staining 3 days later and no changes in AMPK or p38 MAPK activity. The increase in SA-gal staining was preceded by increases in both p53 phosphorylation (S15) (1 h) and transactivation (6 h) and the abundance of the cyclin inhibitor p21(CIP1) (16 h). Incubation with AICAR or resveratrol, both of which activated AMPK, prevented the H(2)O(2)-induced increases in both SA-Gal staining and p21 abundance. In addition, AICAR diminished the increase in p53 transactivation. The decreases in SA-Gal expression induced by resveratrol and AICAR were prevented by the pharmacological AMPK inhibitor Compound C, expression of a DN-AMPK or AMPK knock-down with shRNA. Likewise, both knockdown of AMPK and expression of DN-AMPK were sufficient to induce senescence, even in the absence of exogenous H(2)O(2). As reported by others, we found that AMPK activation by itself increased p53 phosphorylation at S15 in embryonic fibroblasts (MEF), whereas under the same conditions it decreased p53 phosphorylation in the keratinocytes, human aortic endothelial cells, and human HT1080 fibrosarcoma cells. In conclusion, the results indicate that H(2)O(2) at low concentrations causes premature senescence in human keratinocytes by activating p53-p21(CIP1) signaling and that these effects can be prevented by acute AMPK activation and enhanced by AMPK downregulation. They also suggest that this action of AMPK may be cell or context-specific.