title: Cellular localization of NRF2 determines the self-renewal and osteogenic differentiation potential of human MSCs via the P53-SIRT1 axis.
abstract: NRF2 (nuclear factor erythroid-derived 2-like 2) plays an important role in defense against oxidative stress at the cellular level. Recently, the roles of NRF2 in embryonic and adult stem cells have been reported, but its role in maintaining self-renewal and differentiation potential remains unknown. We studied the mechanisms of NRF2 action in mesenchymal stem cells (MSCs) derived from human bone marrow. We found that the cellular localization of NRF2 changed during prolonged cell passage and osteogenic differentiation. Blocking the nuclear import of NRF2 using ochratoxin A (OTA) induced the loss of the self-renewal and osteogenic potential of early-passage (EP) MSCs. Conversely, reinforcing the nuclear import of NRF2 using tert-butylhydroquinone (t-BHQ) improved the self-renewal capacity and maintained the differentiation potential in the osteogenic lineage of EP MSCs. Real-time quantitative PCR and western blot analysis showed that NRF2 positively regulates sirtuin 1 (SIRT1) at the mRNA and protein levels via the negative regulation of p53. The self-renewal and osteogenic potential suppressed in OTA-treated or NRF2-targeting small hairpin RNA (shRNA)-infected EP MSCs were rescued by introducing small interfering RNA (siRNA) targeting p53. t-BHQ treatment in late-passage (LP) MSCs, which lost their self-renewal and osteogenic potential, reversed these effects. In LP MSCs treated with t-BHQ for ∼7 days, the phosphorylation and nuclear localization of NRF2 improved and SIRT1 protein level increased, whereas p53 protein levels decreased. Therefore, our results suggest that NRF2 plays an important role in regulating p53 and SIRT1 to maintain MSC stemness. This study is the first to establish a functional link between NRF2 and SIRT1 expression in the maintenance of MSC self-renewal and differentiation potential.
authors: Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, South Korea.
authors: D S
authors: DS
authors: Yoon
authors: Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, South Korea.|Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, South Korea.
authors: Y
authors: Y
authors: Choi
authors: Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, South Korea.|Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, South Korea.
authors: J W
authors: JW
authors: Lee
mesh_terms: D000328:Adult; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D002478:Cells, Cultured; D057809:HEK293 Cells; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology; D010766:Phosphorylation; D056564:Sirtuin 1 / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D016159:Tumor Suppressor Protein p53; C447939:SIRT1 protein, human; D056564:Sirtuin 1