Jing-Yi Liu1, Xue Chen1, Lin Yue1, George T-J Huang2, Xiao-Ying Zou3. 1. Department of Cariology, Endodontology and Operative Dentistry, School and Hospital of Stomatology, Peking University, Beijing, People's Republic of China. 2. Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, Memphis, Tennessee. 3. Department of Cariology, Endodontology and Operative Dentistry, School and Hospital of Stomatology, Peking University, Beijing, People's Republic of China. Electronic address: zouxiaoying1125@163.com.
Abstract
INTRODUCTION: Stem cells from the apical papilla (SCAPs) at the apex may be attracted into the root canal space as a cell source for pulp-dentin regeneration. To test this possibility, we used in vitro transmigration models to investigate whether SCAPs can be chemoattracted by the delivery of the chemotactic cytokine stromal cell-derived factor-1α (SDF-1α). METHODS: We first examined the expression of CXC chemokine receptor 4 (CXCR4) for SDF-1α in the apical papilla and in cultured SCAPs using immunofluorescence, reverse-transcription polymerase chain reaction (RT-PCR), and flow cytometric analyses. A standard Transwell migration assay and a 3-dimensional cell migration assay were used to analyze transmigration of SCAPs via the SDF-1α/CXCR4 axis. RESULTS: CXCR4 was expressed in the paravascular region of the apical papilla and detected in SCAP cultures. Most cultured SCAPs harbored intracellular CXCR4 (58%-99%, n = 4), whereas only a few cells had detectable CXCR4 on the cell surface (0.3%-2.34%, n = 4). Although SDF-1α had no significant effect on SCAP proliferation, it significantly promoted a higher number of migrated cells; this effect was abolished by anti-CXCR4 antibodies. Interestingly, cell surface CXCR4 on SCAPs was not detectable until after transmigration. The 3-dimensional migration assay revealed that SDF-1α significantly enhanced SCAP migration in the collagen gel. CONCLUSIONS: SCAPs can be chemoattracted via the SDF-1α/CXCR4 axis, suggesting that SDF-1α may be used clinically to induce CXCR4-expressing SCAPs in the apical papilla to transmigrate into the root canal space as an endogenous cell source for pulp regeneration.
INTRODUCTION: Stem cells from the apical papilla (SCAPs) at the apex may be attracted into the root canal space as a cell source for pulp-dentin regeneration. To test this possibility, we used in vitro transmigration models to investigate whether SCAPs can be chemoattracted by the delivery of the chemotactic cytokine stromal cell-derived factor-1α (SDF-1α). METHODS: We first examined the expression of CXC chemokine receptor 4 (CXCR4) for SDF-1α in the apical papilla and in cultured SCAPs using immunofluorescence, reverse-transcription polymerase chain reaction (RT-PCR), and flow cytometric analyses. A standard Transwell migration assay and a 3-dimensional cell migration assay were used to analyze transmigration of SCAPs via the SDF-1α/CXCR4 axis. RESULTS:CXCR4 was expressed in the paravascular region of the apical papilla and detected in SCAP cultures. Most cultured SCAPs harbored intracellular CXCR4 (58%-99%, n = 4), whereas only a few cells had detectable CXCR4 on the cell surface (0.3%-2.34%, n = 4). Although SDF-1α had no significant effect on SCAP proliferation, it significantly promoted a higher number of migrated cells; this effect was abolished by anti-CXCR4 antibodies. Interestingly, cell surface CXCR4 on SCAPs was not detectable until after transmigration. The 3-dimensional migration assay revealed that SDF-1α significantly enhanced SCAP migration in the collagen gel. CONCLUSIONS: SCAPs can be chemoattracted via the SDF-1α/CXCR4 axis, suggesting that SDF-1α may be used clinically to induce CXCR4-expressing SCAPs in the apical papilla to transmigrate into the root canal space as an endogenous cell source for pulp regeneration.
Authors: Ronald B Driesen; Petra Hilkens; Nick Smisdom; Tim Vangansewinkel; Yörg Dillen; Jessica Ratajczak; Esther Wolfs; Pascal Gervois; Marcel Ameloot; Annelies Bronckaers; Ivo Lambrichts Journal: Front Cell Dev Biol Date: 2020-01-21