Carolina Cucco1, Zhaocheng Zhang2, Tatiana M Botero2, Daniel J Chiego2, Rogerio M Castilho3, Jacques E Nör4. 1. Department of Cariology, Restorative Sciences, Endodontics, University of Michigan School of Dentistry, Ann Arbor, Michigan; Department of Endodontics, University of Iowa College of Dentistry, Iowa City, Iowa. 2. Department of Cariology, Restorative Sciences, Endodontics, University of Michigan School of Dentistry, Ann Arbor, Michigan. 3. Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, Michigan. 4. Department of Cariology, Restorative Sciences, Endodontics, University of Michigan School of Dentistry, Ann Arbor, Michigan; Department of Biomedical Engineering, University of Michigan College of Engineering, Ann Arbor, Michigan; Department of Otolaryngology, University of Michigan School of Medicine, Ann Arbor, Michigan; Comprehensive Cancer Center, University of Michigan, Ann Arbor, Michigan. Electronic address: jenor@umich.edu.
Abstract
INTRODUCTION: The maintenance of a stem cell pool is imperative to enable healing processes in the dental pulp tissue throughout life. As such, knowing mechanisms underlying stem cell self-renewal is critical to understand pulp pathophysiology and pulp regeneration. The purpose of this study was to evaluate the impact of stem cell factor (SCF) signaling through its receptor tyrosine kinase (c-Kit) on the self-renewal of human dental pulp stem cells (hDPSCs). METHODS: The hDPSCs were stably transduced with lentiviral vectors expressing shRNA-c-Kit or vector control. The impact of the SCF/c-Kit axis on hDPSC self-renewal was evaluated by using a pulpsphere assay in low attachment conditions and by evaluating the expression of polycomb complex protein Bmi-1 (master regulator of self-renewal) by Western blot and flow cytometry. RESULTS: The c-Kit-silenced hDPSCs formed fewer pulpspheres when compared with hDPSCs transduced with control vector (P < .05). Evaluation of pulpsphere morphology revealed the presence of 3 distinct sphere types, ie, holospheres, merospheres, and paraspheres. Although c-Kit silencing decreased the number of holospheres compared with control cells (P < .05), it had no effect on the number of merospheres and paraspheres. Recombinant human stem cell factor (rhSCF) increased the number of holospheres (P < .05) and induced dose-dependent Bmi-1 expression in hDPSCs. As expected, the inductive capacity of rhSCF on Bmi-1 expression and fraction of Bmi-1-positive cells was inhibited when we silenced c-Kit in hDPSCs. CONCLUSIONS: These results unveiled the role of SCF/c-Kit signaling on the self-renewal of hDPSCs and suggested that this pathway enables long-term maintenance of stem cell pools in human dental pulps.
INTRODUCTION: The maintenance of a stem cell pool is imperative to enable healing processes in the dental pulp tissue throughout life. As such, knowing mechanisms underlying stem cell self-renewal is critical to understand pulp pathophysiology and pulp regeneration. The purpose of this study was to evaluate the impact of stem cell factor (SCF) signaling through its receptor tyrosine kinase (c-Kit) on the self-renewal of human dental pulp stem cells (hDPSCs). METHODS: The hDPSCs were stably transduced with lentiviral vectors expressing shRNA-c-Kit or vector control. The impact of the SCF/c-Kit axis on hDPSC self-renewal was evaluated by using a pulpsphere assay in low attachment conditions and by evaluating the expression of polycomb complex protein Bmi-1 (master regulator of self-renewal) by Western blot and flow cytometry. RESULTS: The c-Kit-silenced hDPSCs formed fewer pulpspheres when compared with hDPSCs transduced with control vector (P < .05). Evaluation of pulpsphere morphology revealed the presence of 3 distinct sphere types, ie, holospheres, merospheres, and paraspheres. Although c-Kit silencing decreased the number of holospheres compared with control cells (P < .05), it had no effect on the number of merospheres and paraspheres. Recombinant humanstem cell factor (rhSCF) increased the number of holospheres (P < .05) and induced dose-dependent Bmi-1 expression in hDPSCs. As expected, the inductive capacity of rhSCF on Bmi-1 expression and fraction of Bmi-1-positive cells was inhibited when we silenced c-Kit in hDPSCs. CONCLUSIONS: These results unveiled the role of SCF/c-Kit signaling on the self-renewal of hDPSCs and suggested that this pathway enables long-term maintenance of stem cell pools in human dental pulps.
Authors: Y Yarden; W J Kuang; T Yang-Feng; L Coussens; S Munemitsu; T J Dull; E Chen; J Schlessinger; U Francke; A Ullrich Journal: EMBO J Date: 1987-11 Impact factor: 11.598
Authors: Zi Y Kok; Nadia Y A Alaidaroos; Amr Alraies; John S Colombo; Lindsay C Davies; Rachel J Waddington; Alastair J Sloan; Ryan Moseley Journal: Stem Cells Int Date: 2022-01-04 Impact factor: 5.443