title: Up-regulation of nicotinamide phosphoribosyltransferase and increase of NAD+ levels by glucose restriction extend replicative lifespan of human fibroblast Hs68 cells.
abstract: Calorie restriction (CR) extends lifespan in a remarkable range of organisms. However, the mechanisms of CR related to the longevity effects are not fully elucidated to date. Using human fibroblast Hs68 (Hs68) cells cultured at a lower level of medium glucose (i.e., glucose restriction; GR) to mimic CR, we investigated the crucial role of nicotinamide phosphoribosyltransferase (Nampt), nicotinamide adenine dinucleotide (NAD(+)), and nicotinamide (NAM) in GR-extended replicative lifespan of Hs68 cells. We found that GR extended the lifespan of Hs68 cells, in parallel to significantly increased expression of Nampt, intracellular NAD(+) levels, and SIRT1 activities, and to significantly decreased NAM levels. The lifespan-extending effects of GR were profoundly diminished by FK866 (a noncompetitive inhibitor of Nampt) and blocked by sirtinol (a noncompetitive inhibitor of sirtuins). However, the steady-state intracellular NAM level (averaged 2.5 μM) was much lower than the IC50 of NAM on human SIRT1 (about 50 μM). All these results suggest that up-regulation of Nampt play an important role in GR-extended lifespan of Hs68 cells by increasing the intracellular NAD(+) levels followed by activating SIRT1 activity in Hs68 cells. In contrast, the role of NAM depletion is limited.
authors.affiliation: School of Nutrition, Chung Shan Medical University, No.110, Sec.1, Jianguo N. Rd., Taichung City, 40201, Taiwan, ROC, naeman@csmu.edu.tw.
authors.forename: Nae-Cherng
authors.initials: NC
authors.lastname: Yang
authors.forename: Tuzz-Ying
authors.initials: TY
authors.lastname: Song
authors.forename: Yan-Zin
authors.initials: YZ
authors.lastname: Chang
authors.forename: Mei-Yau
authors.initials: MY
authors.lastname: Chen
authors.forename: Miao-Lin
authors.initials: ML
authors.lastname: Hu
mesh_terms: D000178:Acrylamides / Q000494:pharmacology; D001549:Benzamides / Q000494:pharmacology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects* / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects* / Q000502:physiology; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D009243:NAD / Q000378:metabolism*; D009284:Naphthols / Q000494:pharmacology; D009536:Niacinamide / Q000378:metabolism; D054409:Nicotinamide Phosphoribosyltransferase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010880:Piperidines / Q000494:pharmacology; D056564:Sirtuin 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects*
chemical_list: D000178:Acrylamides; D001549:Benzamides; D016207:Cytokines; C480543:N-(4-(1-benzoylpiperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide; D009284:Naphthols; D010880:Piperidines; C439060:sirtinol; D009243:NAD; D009536:Niacinamide; D054409:Nicotinamide Phosphoribosyltransferase; C085455:nicotinamide phosphoribosyltransferase, human; C447939:SIRT1 protein, human; D056564:Sirtuin 1; D005947:Glucose