title: The crucial role of vitamin C and its transporter (SVCT2) in bone marrow stromal cell autophagy and apoptosis.
abstract: Vitamin C is an antioxidant that plays a vital role in various biological processes including bone formation. Previously, we reported that vitamin C is transported into bone marrow stromal cells (BMSCs) through the sodium dependent Vitamin C Transporter 2 (SVCT2) and this transporter plays an important role in osteogenic differentiation. Furthermore, this transporter is regulated by oxidative stress. To date, however, the exact role of vitamin C and its transporter (SVCT2) in ROS regulated autophagy and apoptosis in BMSCs is poorly understood. In the present study, we observed that oxidative stress decreased survival of BMSCs in a dose-dependent manner and induced growth arrest in the G1 phase of the cell cycle. These effects were accompanied by the induction of autophagy, confirmed by P62 and LC3B protein level and punctate GFP-LC3B distribution. The supplementation of vitamin C significantly rescued the BMSCs from oxidative stress by regulating autophagy. Knockdown of the SVCT2 transporter in BMSCs synergistically decreased cell survival even under low oxidative stress conditions. Also, supplementing vitamin C failed to rescue cells from stress. Our results reveal that the SVCT2 transporter plays a vital role in the mechanism of BMSC survival under stress conditions. Altogether, this study has given new insight into the role of the SVCT2 transporter in oxidative stress related autophagy and apoptosis in BMSCs.
authors.affiliation: Department of Orthopaedic Surgery, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: Rajnikumar
authors.initials: R
authors.lastname: Sangani
authors.affiliation: Cellular Biology and Anatomy, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: Sudharsan
authors.initials: S
authors.lastname: Periyasamy-Thandavan
authors.affiliation: Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: Rajneesh
authors.initials: R
authors.lastname: Pathania
authors.affiliation: Department of Ophthalmology, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: Saif
authors.initials: S
authors.lastname: Ahmad
authors.affiliation: Department of Pathology, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: Ammar
authors.initials: A
authors.lastname: Kutiyanawalla
authors.affiliation: Department of Pathology, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: Ravindra
authors.initials: R
authors.lastname: Kolhe
authors.affiliation: Department of Orthopaedic Surgery, Georgia Regents University, Augusta, GA 30912, USA; Institute of Regenerative and Reparative Medicine, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: Maryka H
authors.initials: MH
authors.lastname: Bhattacharyya
authors.affiliation: Department of Orthopaedic Surgery, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: Norman
authors.initials: N
authors.lastname: Chutkan
authors.affiliation: Department of Orthopaedic Surgery, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: Monte
authors.initials: M
authors.lastname: Hunter
authors.affiliation: Cellular Biology and Anatomy, Georgia Regents University, Augusta, GA 30912, USA; Institute of Regenerative and Reparative Medicine, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: William D
authors.initials: WD
authors.lastname: Hill
authors.affiliation: Cellular Biology and Anatomy, Georgia Regents University, Augusta, GA 30912, USA; Institute of Regenerative and Reparative Medicine, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Hamrick
authors.affiliation: Department of Orthopaedic Surgery, Georgia Regents University, Augusta, GA 30912, USA; Institute of Regenerative and Reparative Medicine, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: Carlos
authors.initials: C
authors.lastname: Isales
authors.affiliation: Department of Orthopaedic Surgery, Georgia Regents University, Augusta, GA 30912, USA; Institute of Regenerative and Reparative Medicine, Georgia Regents University, Augusta, GA 30912, USA. Electronic address: sfulzele@gru.edu.
authors.forename: Sadanand
authors.initials: S
authors.lastname: Fulzele
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001205:Ascorbic Acid / Q000494:pharmacology*; D001343:Autophagy / Q000187:drug effects*; D001854:Bone Marrow Cells / Q000166:cytology*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D059585:G1 Phase Cell Cycle Checkpoints / Q000187:drug effects; D006360:Heat-Shock Proteins / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects; D000071456:Sequestosome-1 Protein; D060347:Sodium-Coupled Vitamin C Transporters / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D006360:Heat-Shock Proteins; C480860:Map1lc3b protein, mouse; D008869:Microtubule-Associated Proteins; D016877:Oxidants; D000071456:Sequestosome-1 Protein; C555165:Slc23a2 protein, mouse; D060347:Sodium-Coupled Vitamin C Transporters; C101343:Sqstm1 protein, mouse; D001205:Ascorbic Acid