Nicotinamide phosphoribosyltransferase delays cellular senescence by upregulating SIRT1 activity and antioxidant gene expression in mouse cells

In this study, we found that primary mouse embryonic fibroblast (MEF) cells undergo progressive decline of NAMPT and NAD+ contents during serial passaging before becoming senescent. Furthermore, we showed that constitutive Nampt over‐expression increases cellular NAD+ content and delays cellular senescence of MEF cells in vitro. We further found that constitutive Nampt over‐expression increases SIRT1 activity, increases the expression of antioxidant genes, superoxide dismutase 2 and catalase and promotes resistance against oxidative stress. These findings suggest that Nampt over‐expression in MEF cells delays cellular senescence by the mitigation of oxidative stress via the upregulation of superoxide dismutase 2 and catalase gene expressions by SIRT1 activation. We showed that constitutive Nampt over‐expression elevates cellular NAD+ content, SIRT1 activity, superoxide dismutase 2 and catalase mRNA expressions and extends the replicative lifespan in MEF cells. These findings suggest that Nampt over‐expression in MEF cells delays cellular senescence by the mitigation of oxidative stress via the upregulation of superoxide dismutase 2 and catalase gene expressions by SIRT1 activation.
Source: Genes to Cells - Category: Genetics & Stem Cells Authors: Tags: ORIGINAL ARTICLE Source Type: research