title: Combined activation of the energy and cellular-defense pathways may explain the potent anti-senescence activity of methylene blue.
abstract: Methylene blue (MB) delays cellular senescence, induces complex-IV, and activates Keap1/Nrf2; however, the molecular link of these effects to MB is unclear. Since MB is redox-active, we investigated its effect on the NAD/NADH ratio in IMR90 cells. The transient increase in NAD/NADH observed in MB-treated cells triggered an investigation of the energy regulator AMPK. MB induced AMPK phosphorylation in a transient pattern, which was followed by the induction of PGC1α and SURF1: both are inducers of mitochondrial and complex-IV biogenesis. Subsequently MB-treated cells exhibited >100% increase in complex-IV activity and a 28% decline in cellular oxidants. The telomeres erosion rate was also significantly lower in MB-treated cells. A previous research suggested that the pattern of AMPK activation (i.e., chronic or transient) determines the AMPK effect on cell senescence. We identified that the anti-senescence activity of MB (transient activator) was 8-times higher than that of AICAR (chronic activator). Since MB lacked an effect on cell cycle, an MB-dependent change to cell cycle is unlikely to contribute to the anti-senescence activity. The current findings in conjunction with the activation of Keap1/Nrf2 suggest a synchronized activation of the energy and cellular defense pathways as a possible key factor in MB's potent anti-senescence activity.
authors.affiliation: College of Medicine, California University of Science & Medicine, Colton, CA 92324, USA; Department of Basic Sciences, The Commonwealth Medical College (TCMC), Scranton, PA 18509, USA. Electronic address: atamnah@calmedu.org.
authors.forename: Hani
authors.initials: H
authors.lastname: Atamna
authors.affiliation: Department of Basic Sciences, The Commonwealth Medical College (TCMC), Scranton, PA 18509, USA.
authors.forename: Wafa
authors.initials: W
authors.lastname: Atamna
authors.affiliation: College of Medicine, California University of Science & Medicine, Colton, CA 92324, USA.
authors.forename: Ghaith
authors.initials: G
authors.lastname: Al-Eyd
authors.affiliation: Department of Basic Sciences, The Commonwealth Medical College (TCMC), Scranton, PA 18509, USA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Shanower
authors.affiliation: Department of Biochemistry, University of California at Riverside, 92521, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Dhahbi
mesh_terms: D000263:Adenylate Kinase / Q000378:metabolism; D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D016922:Cellular Senescence / Q000187:drug effects*; D004353:Drug Evaluation, Preclinical; D003576:Electron Transport Complex IV / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects*; D006801:Humans; D008751:Methylene Blue / Q000494:pharmacology*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D051336:Mitochondrial Membranes / Q000187:drug effects / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D012265:Ribonucleotides / Q000494:pharmacology; D059505:Telomere Homeostasis / Q000187:drug effects; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation
chemical_list: C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D012265:Ribonucleotides; D014157:Transcription Factors; D009243:NAD; D000620:Aminoimidazole Carboxamide; D003576:Electron Transport Complex IV; D000263:Adenylate Kinase; C031143:AICA ribonucleotide; D008751:Methylene Blue
keywords: AMPK; Complex-IV; Mitochondria; NAD; Oxidants; Senescence; Telomeres