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Anibal R Diogenes - One of the best experts on this subject based on the ideXlab platform.
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Does Apical Papilla survive and develop in Apical periodontitis presence after regenerative endodontic procedures
Applied Sciences, 2019Co-Authors: Paulo Palma, Anibal R Diogenes, João Martins, Patrícia Diogo, Diana Sequeira, João Carlos Ramos, João Miguel SantosAbstract:Regenerative endodontic procedures (REPs) have emerged as a treatment option for immature necrotic teeth to allow the reestablishment of a newly formed vital tissue and enable continued root development. The Apical Papilla stem cells (SCAPs) play an important role in physiologic root development and may also contribute to further root development during REPs. The goal of these case reports is to show evidence of the Apical Papilla survival and development, in human teeth with Apical periodontitis, after REPs, with 5-year clinical and radiographic follow-up. In the first case, an 11-year-old girl with acute Apical abscess of tooth 15 was referred for a REP. Treatment was performed with an intracanal medication followed by induction of a blood clot and a Mineral Trioxide Aggregate (MTA) cervical barrier. The 5-year follow-up showed an appreciable increase in root length as well as root canal thickness. In case 2, a 16-year-old girl was referred for endodontic treatment of tooth 21. The parents of the patient recalled a previous dental trauma (no specified on the patient records) on tooth 21 at age 7. The dental history reports a previous endodontic treatment failure and presence of a long-standing sinus tract. A mineralized tissue beyond the root Apical portion could be seen at the preoperative X-ray. Nonsurgical root canal retreatment with an Apical barrier was suggested as the treatment plan and accepted by the patient. After 2 weeks, the patient was recalled for a follow-up appointment presenting spontaneous pain, swelling, and sinus tract. Apical surgery was performed. Histopathological assessment of the Apical root fragment collected showed the presence of dentin, cementum and pulp tissue, including odontoblasts. The 5-year follow-up depicted complete Apical healing. The present case reports support survival and continued potential differentiation of the Apical Papilla after endodontic infection.
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Direct and Indirect Effect of Chlorhexidine on Survival of Stem Cells from the Apical Papilla and Its Neutralization
Journal of Endodontics, 2019Co-Authors: Matthias Widbiller, Riyadh I. Althumairy, Anibal R DiogenesAbstract:Abstract Introduction Several irrigants have been used for disinfection in regenerative endodontic procedures including chlorhexidine (CHX). In this context, the antibacterial properties of disinfectants are mainly in focus of research even though they may have an undesirable impact on the fate of stem cells. In this study, we hypothesized that CHX has both a direct effect when applied to stem cells of the Apical Papilla (SCAPs) and an indirect effect when SCAPs are exposed to dentin previously conditioned with CHX. Methods Cell toxicity was evaluated in vitro using the CellTox green fluorescence assay (Promega, Madison, WI) and CellTiter-Glo (Promega) after SCAPs were exposed directly to a dynamic concentration range of CHX; Apical Papilla explant cultures were stained with ApopTag (Merck Millipore, Billerica, MA) after culture with CHX. Furthermore, standardized slabs from human dentin were treated with CHX and consecutively rinsed in EDTA, L-α-lecithin (Sigma-Aldrich, St Louis, MO), or L-α-lecithin followed by EDTA. After that, SCAPs were cultured on the slabs for 5 days, and cellular viability was determined (indirect effect). Data were treated nonparametrically and analyzed using the Krukal-Wallis test (P ≤ .05). Results Direct exposure of SCAPs to CHX highly affected cell viability at concentrations above 10−3%, whereas lower concentrations had no adverse effect. During the initial 60 minutes, concentrations of 10−2% CHX or higher resulted in early pronounced toxicity with a maximum effect within 15 minutes after exposure. Likewise, CHX-conditioned dentin slabs were detrimental to SCAP survival; however, the deleterious effects were completely reversed by neutralization with L-α-lecithin. Conclusions Chlorhexidine is toxic to SCAPs when applied directly or indirectly via conditioned dentin. If applied for a short time and neutralized by L-α-lecithin, it can be a gentle and cell-preserving disinfectant before endodontic regeneration.
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Survival of the Apical Papilla and Its Resident Stem Cells in a Case of Advanced Pulpal Necrosis and Apical Periodontitis
Journal of Endodontics, 2017Co-Authors: Vanessa Chrepa, Brandon Pitcher, Michael A. Henry, Anibal R DiogenesAbstract:Abstract Introduction Apical Papilla represents a source of an enriched mesenchymal stem cell (MSC) population (stem cells of the Apical Papilla [SCAPs]) that modulates root development and may participate in regenerative endodontic procedures in immature teeth with pulp necrosis. The characteristics and phenotype of this tissue in the presence of inflammation are largely unknown. The purpose of this study was to characterize a human Apical Papilla sample that was isolated from an immature tooth with pulp necrosis and Apical periodontitis. Methods Inflamed periApical tissue that included part of the Apical Papilla (Apical Papilla clinical sample [CS]) was collected from an immature mandibular premolar previously diagnosed with pulp necrosis and Apical periodontitis during an apexification procedure. Harvested cells from this tissue (SCAP CS) were compared with inflamed periApical progenitor cells (IPAPCs) and normal SCAP (SCAP-RP89) in flow cytometry and quantitative osteogenesis experiments. Part of the issue was further processed for immunohistochemistry and compared with Apical Papilla and coronal pulp sections from normal immature teeth as well as inflamed periApical tissues from mature teeth. Results Similar to SCAP-RP89, 96.6% of the SCAP CS coexpressed the MSC markers CD73, CD90, and CD105, whereas only 66.3% of IPAPCs coexpressed all markers. The SCAP CS showed a significantly greater mineralization potential than both SCAP-RP89 and IPAPCs. Finally, immunohistochemical analysis revealed moderate infiltration of cells expressing the inflammatory markers CD45/68 in the Apical Papilla CS and prominent CD24, CD105, and von Willebrand factor expression. Conclusions Under inflammatory conditions, human Apical Papilla was found moderately inflamed with retained SCAP vitality and stemness and increased osteogenic and angiogenesis potential.
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EphrinB2 Stabilizes Vascularlike Structures Generated by Endothelial Cells and Stem Cells from Apical Papilla.
Journal of Endodontics, 2016Co-Authors: Changyong Yuan, Anibal R Diogenes, Penglai Wang, Shaoyue Zhu, Ting Zou, Shuai Wang, Boon Chin Heng, Chengfei ZhangAbstract:Abstract Introduction This study aimed to investigate the roles of ephrinB2 in stabilizing vascularlike structures generated by stem cells from Apical Papilla (SCAPs) and human umbilical vein endothelial cells (HUVECs). Methods HUVECs were seeded alone or with SCAPs concurrently or 12 hours later. Angiogenesis and ephrinB2 phosphorylation were assayed at different time points. Additionally, ephrinB2 expression in SCAPs and HUVECs was silenced with small interfering RNA, and vascularlike structure formation within coculture was assessed; 1 × 10 5 HUVECs were seeded in transwell inserts, and 6 × 10 5 SCAPs were plated in lower wells with or without ephrinB2-Fc. Migratory cells were stained and counted. Delayed addition of ephrinB2-Fc to the coculture of HUVECs and SCAPs was performed to evaluate the role of ephrinB2 on the stabilization of vascularlike structures. Results Concurrent coculture of SCAPs and HUVECs yielded significantly longer tubule lengths at 4, 8, and 12 hours ( P Conclusions EphrinB2 plays an important role in the stabilization of vascularlike structures generated by HUVECs and SCAPs.
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Dental Apical Papilla as Therapy for Spinal Cord Injury
Journal of Dental Research, 2015Co-Authors: P. De Berdt, Anibal R Diogenes, Julie Vanacker, Bernard Ucakar, Laure Elens, Julian Leprince, Ronald Deumens, A. Des RieuxAbstract:Stem cells of the Apical Papilla (SCAP) represent great promise regarding treatment of neural tissue damage, such as spinal cord injury (SCI). They derive from the neural crest, express numerous neurogenic markers, and mediate neurite outgrowth and axonal targeting. The goal of the present work was to investigate for the first time their potential to promote motor recovery after SCI in a rat hemisection model when delivered in their original stem cell niche-that is, by transplantation of the human Apical Papilla tissue itself into the lesion. Control groups consisted of animals subjected to laminectomy only (shams) and to lesion either untreated or injected with a fibrin hydrogel with or without human SCAP. Basso-Beattie-Bresnahan locomotor scores at 1 and 3 d postsurgery confirmed early functional decline in all SCI groups. This significant impairment was reversed, as seen in CatWalk analyses, after transplantation of Apical Papilla into the injured spinal cord wound, whereas the other groups demonstrated persistent functional impairment. Moreover, tactile allodynia did not develop as an unwanted side effect in any of the groups, even though the SCAP hydrogel group showed higher expression of the microglial marker Iba-1, which has been frequently associated with allodynia. Notably, the Apical Papilla transplant group presented with reduced Iba-1 expression level. Masson trichrome and human mitochondria staining showed the preservation of the Apical Papilla integrity and the presence of numerous human cells, while human cells could no longer be detected in the SCAP hydrogel group at the 6-wk postsurgery time point. Altogether, our data suggest that the transplantation of a human Apical Papilla at the lesion site improves gait in spinally injured rats and reduces glial reactivity. It also underlines the potential interest for the application of delivering SCAP in their original niche, as compared with use of a fibrin hydrogel.
George T.-j. Huang - One of the best experts on this subject based on the ideXlab platform.
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cxc chemokine receptor 4 is expressed paravascularly in Apical Papilla and coordinates with stromal cell derived factor 1α during transmigration of stem cells from Apical Papilla
Journal of Endodontics, 2015Co-Authors: Jing-yi Liu, Xue Chen, Lin Yue, George T.-j. Huang, Xiao-ying ZouAbstract: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.
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CXC Chemokine Receptor 4 Is Expressed Paravascularly in Apical Papilla and Coordinates with Stromal Cell–derived Factor-1α during Transmigration of Stem Cells from Apical Papilla
Journal of Endodontics, 2015Co-Authors: Jing-yi Liu, Xue Chen, Lin Yue, George T.-j. Huang, Xiao-ying ZouAbstract: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.
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NOTCH3 is expressed in human Apical Papilla and in subpopulations of stem cells isolated from the tissue.
Genes & Diseases, 2015Co-Authors: Mohamed Jamal, Sami Chogle, Sherif M. Karam, George T.-j. HuangAbstract:NOTCH plays a role in regulating stem cell function and fate decision. It is involved in tooth development and injury repair. Information regarding NOTCH expression in human dental root Apical Papilla (AP) and its residing stem cells (SCAP) is limited. Here we investigated the expression of NOTCH3, its ligand JAG1, and mesenchymal stem cell markers CD146 and STRO-1 in the AP or in the primary cultures of SCAP isolated from AP. Our in situ immunostaining showed that in the AP NOTCH3 and CD146 were co-expressed and associated with blood vessels having NOTCH3 located more peripherally. In cultured SCAP, NOTCH3 and JAG1 were co-expressed. Flow cytometry analysis showed that 7%, 16% and 98% of the isolated SCAP were positive for NOTCH3, STRO-1 and CD146, respectively with a rare 1.5% subpopulation of SCAP co-expressing all three markers. The expression level of NOTCH3 reduced when SCAP underwent osteogenic differentiation. Our findings are the first step towards defining the regulatory role of NOTCH3 in SCAP fate decision.
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Basic fibroblast growth factor enhances stemness of human stem cells from the Apical Papilla.
Journal of Endodontics, 2012Co-Authors: George T.-j. Huang, Ping Wang, Zhongchun Tong, Qian Jia, Liping Dong, Zhongying NiuAbstract:Introduction Stem cells from the Apical Papilla (SCAP) are a type of mesenchymal stem cells found in the developing tissue, Apical Papilla, of immature permanent teeth. Studies have shown that SCAP are likely to be a source of primary odontoblasts that are responsible for the formation of root dentin. Basic fibroblast growth factor (bFGF) is a signaling molecule and pleiotropic growth factor involved in tooth root development, and it promotes proliferation of a variety of cell types. The effects of bFGF on SCAP, however, have not been examined.
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the hidden treasure in Apical Papilla the potential role in pulp dentin regeneration and bioroot engineering
Journal of Endodontics, 2008Co-Authors: George T.-j. Huang, Wataru Sonoyama, Yi Liu, Songlin Wang, He Liu, Songtao ShiAbstract:Some clinical case reports have shown that immature permanent teeth with periradicular periodontitis or abscess can undergo apexogenesis after conservative endodontic treatment. A call for a paradigm shift and new protocol for the clinical management of these cases has been brought to attention. Concomitantly, a new population of mesenchymal stem cells residing in the Apical Papilla of permanent immature teeth recently has been discovered and was termed stem cells from the Apical Papilla (SCAP). These stem cells appear to be the source of odontoblasts that are responsible for the formation of root dentin. Conservation of these stem cells when treating immature teeth may allow continuous formation of the root to completion. This article reviews current findings on the isolation and characterization of these stem cells. The potential role of these stem cells in the following respects will be discussed: (1) their contribution in continued root maturation in endodontically treated immature teeth with periradicular periodontitis or abscess and (2) their potential utilization for pulp/dentin regeneration and bioroot engineering.
J. Zhang - One of the best experts on this subject based on the ideXlab platform.
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the transcription factor cyclic adenosine 3 5 monophosphate response element binding protein enhances the odonto osteogenic differentiation of stem cells from the Apical Papilla
International Endodontic Journal, 2017Co-Authors: Y. Zhu, Yan-hua Liang, J. ZhangAbstract:Aim To investigate the role of cAMP response element-binding protein (CREB) in the regulation of odonto/osteogenic differentiation of stem cells from the Apical Papilla (SCAPs). Methodology Stem cells from the Apical Papilla were obtained from human impacted third molars (n = 15). Isolated SCAPs were transfected with CREB overexpressing/silenced lentivirus. Transfected cells were stained with alizarin red to investigate mineralized nodule formation. The expression of the mineralization-related genes, alkaline phosphatase (ALP), collagen type I (Col I), runt-related transcription factor 2 (RUNX2), osterix (OSX) and osteocalcin (OCN), was determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Protein expression of the odontogenic-related marker dentine sialoprotein (DSP) and the osteogenic-related marker RUNX2 was measured by Western blotting analysis. One-way analysis of variance (anova) and Student's t-test were used for statistical analysis (a = 0.05). Results The overexpression of CREB enhanced mineralized nodule formation and up-regulated (P < 0.05) the mRNA levels of odonto/osteogenic-related markers, including ALP, Col I, RUNX2, OSX and OCN, and also increased (P < 0.05) the protein expression of DSP and RUNX2. In contrast, the silencing of CREB inhibited (P < 0.05) the mineralization capacity of the SCAPs and decreased (P < 0.05) the expression of odonto/osteogenic-related markers. Conclusion Up-regulation of CREB expression promoted odonto/osteogenic differentiation of SCAPs and provided a potential method for the regeneration of the dentine–pulp complex.
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The transcription factor cyclic adenosine 3′,5′-monophosphate response element-binding protein enhances the odonto/osteogenic differentiation of stem cells from the Apical Papilla
International Endodontic Journal, 2016Co-Authors: Y. Zhu, Yan-hua Liang, J. ZhangAbstract:Aim To investigate the role of cAMP response element-binding protein (CREB) in the regulation of odonto/osteogenic differentiation of stem cells from the Apical Papilla (SCAPs). Methodology Stem cells from the Apical Papilla were obtained from human impacted third molars (n = 15). Isolated SCAPs were transfected with CREB overexpressing/silenced lentivirus. Transfected cells were stained with alizarin red to investigate mineralized nodule formation. The expression of the mineralization-related genes, alkaline phosphatase (ALP), collagen type I (Col I), runt-related transcription factor 2 (RUNX2), osterix (OSX) and osteocalcin (OCN), was determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Protein expression of the odontogenic-related marker dentine sialoprotein (DSP) and the osteogenic-related marker RUNX2 was measured by Western blotting analysis. One-way analysis of variance (anova) and Student's t-test were used for statistical analysis (a = 0.05). Results The overexpression of CREB enhanced mineralized nodule formation and up-regulated (P
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Nuclear Factor I-C promotes proliferation and differentiation of Apical Papilla-derived human stem cells in vitro.
Experimental Cell Research, 2015Co-Authors: J. Zhang, Zhongying Niu, Zhihua Wang, Paul R. Cooper, Yong Jiang, Zhirong Luo, Anthony J. SmithAbstract:The transcription factor Nuclear Factor I-C (NFIC) has been implicated in the regulation of tooth root development, where it may be anticipated to impact on the behavior of stem cells from the Apical Papilla (SCAPs) and root odontoblast activity. We hypothesized that NFIC may provide an important target for promoting dentin/root regeneration. In the present study, the effects of NFIC on the proliferation and differentiation of SCAPs were investigated. Over-expression of NFIC increased cell proliferation, mineralization nodule formation and alkaline phosphatase (ALP) activity in SCAPs. Furthermore, NFIC up-regulated the mRNA levels of odontogenic-related markers, ALP, osteocalcin and collagen type I as well as dentin sialoprotein protein levels. In contrast, knockdown of NFIC by si-RNA inhibited the mineralization capacity of SCAPs and down-regulated the expression of odontogenic-related markers. In conclusion, the results indicated that upregulation of NFIC activity in SCAPs may promote osteo/odontoblastic differentiation of SCAPs.
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Regulatory Interplay between NFIC and TGF-β1 in Apical Papilla-derived Stem Cells
Journal of Dental Research, 2014Co-Authors: J. Zhang, Zhongying Niu, Zhihua Wang, Rong Zhang, Anthony J. Smith, Paul R. CooperAbstract:While transforming growth factor-β1 (TGF-β1) can regulate odontoblast differentiation in tooth crown morphogenesis, its effects on cells including stem cells from the Apical Papilla (SCAPs) involved in root formation are unclear. Nuclear factor I-C (NFIC) has been implicated in the regulation of root development, and interplay with TGF-β1 signaling has been reported in some cell types. We hypothesize that NFIC and TGF-β1 are important to the behavior of SCAPs and that the interplay between these molecules controls the regulation of the odontogenic differentiation of SCAPs. TGF-β1 inhibited the proliferation of SCAPs and their mineralization. Real-time polymerase chain-reaction (RT-PCR) and Western blot results showed that TGF-β1 significantly decreased osteogenic/dentinogenic gene expression. The inhibition of TGF-β/Smad signaling (SIS3) attenuated the suppressive effect of TGF-β1 on SCAPs. Importantly, overexpression of NFIC antagonized the effects of TGF-β1 on SCAPs, while knockdown of NFIC enhanced the...
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Conditioned medium from periApical follicle cells induces the odontogenic differentiation of stem cells from the Apical Papilla in vitro.
Journal of Endodontics, 2013Co-Authors: Qian Jia, J. Zhang, Jianguo Liu, Lipeng Hou, Zhongying NiuAbstract:Abstract Introduction We investigated the biological effects of conditioned medium (CM) from periApical follicle cells (PAFCs) of root-developing tooth on the proliferation and differentiation of stem cells from the Apical Papilla (SCAP) in vitro . Methods Human SCAP and PAFCs were isolated and expanded. CM from PAFCs was prepared with the primary cells. Cell cycle analysis, methyl-thiazol-diphenyltetrazolium assay, alkaline phosphatase activity, mineralization behavior, and gene expression of odontoblast phenotype SCAP cultured with or without CM from PAFCs were evaluated. Results In the CM-treated group, the cell growth, alkaline phosphatase activity, and mineralization of SCAP were up-regulated. The expression of dentin sialophosphoprotein, alkaline phosphatase, and osteocalcin mRNA progressively increased in SCAP treated with CM from PAFCs. Conclusions Our findings suggest that CM from PAFCs is able to provide a favorable odontogenic microenvironment to induce differentiation of SCAP along the odontoblast lineage.
Jingping Liang - One of the best experts on this subject based on the ideXlab platform.
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effects of wnt β catenin signalling on proliferation and differentiation of Apical Papilla stem cells
Cell Proliferation, 2012Co-Authors: Jia Wang, Bowen Liu, Jingping LiangAbstract:Objectives: The Wnt signalling pathway has been shown to play an important role in tooth development, however its effects with stem cells from the Apical Papilla (SCAP) have remained unclear. The purpose of this study was to determine effects of Wnt ⁄b-catenin on proliferation and differentiation of SCAP in vitro. Materials and methods: SCAP were obtained, identified and cultured. Cell proliferation, alkaline phosphatase (ALP) activity, mRNA expression of mineralization-related genes and mineralized nodule formation were measured in presence or absence of various concentrations of lithium chloride. Results: MTT assay and flow cytometry demonstrated that Wnt ⁄b-catenin activity could promote proliferation of SCAP. Real-time PCR analysis found that Wnt ⁄b-catenin strongly upregulated expression of dentine sialophosphoprotein, osteocalcin and ALP in SCAP after incubation with mineralization induction medium, while ALP and alizarin red staining indicated that Wnt ⁄b-catenin enhanced ALP activity and formation of mineralized nodules. Conclusion: Our results suggest that canonical Wnt ⁄b-catenin signalling promotes proliferation and odonto ⁄osteogenic differentiation of SCAP.
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Effects of Wnt/β-catenin signalling on proliferation and differentiation of Apical Papilla stem cells.
Cell Proliferation, 2012Co-Authors: Jia Wang, Bowen Liu, Jingping LiangAbstract:Objectives: The Wnt signalling pathway has been shown to play an important role in tooth development, however its effects with stem cells from the Apical Papilla (SCAP) have remained unclear. The purpose of this study was to determine effects of Wnt ⁄b-catenin on proliferation and differentiation of SCAP in vitro. Materials and methods: SCAP were obtained, identified and cultured. Cell proliferation, alkaline phosphatase (ALP) activity, mRNA expression of mineralization-related genes and mineralized nodule formation were measured in presence or absence of various concentrations of lithium chloride. Results: MTT assay and flow cytometry demonstrated that Wnt ⁄b-catenin activity could promote proliferation of SCAP. Real-time PCR analysis found that Wnt ⁄b-catenin strongly upregulated expression of dentine sialophosphoprotein, osteocalcin and ALP in SCAP after incubation with mineralization induction medium, while ALP and alizarin red staining indicated that Wnt ⁄b-catenin enhanced ALP activity and formation of mineralized nodules. Conclusion: Our results suggest that canonical Wnt ⁄b-catenin signalling promotes proliferation and odonto ⁄osteogenic differentiation of SCAP.
Athina Bakopoulou - One of the best experts on this subject based on the ideXlab platform.
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Erythropoietin (rhEPOa) promotes endothelial transdifferentiation of stem cells of the Apical Papilla (SCAP)
Archives of Oral Biology, 2018Co-Authors: Anastasios Koutsoumparis, Athina Bakopoulou, Angelina Vassili, Argyro Ziouta, Asterios S. TsiftsoglouAbstract:Abstract Objective Mesenchymal stem cells (MSCs) have attracted worldwide attention for their capacity to repair damaged tissue, immunosuppression, ability to differentiate into several cell types and their secretome. Earlier studies have demonstrated their angiogenic potential in vitro and in vivo. However, little is known regarding pro-angiogenic inducers of stable endothelial transdifferentiation of MSCs. Here, we employed human MSCs from the Apical Papilla (SCAP) and investigated whether recombinant human erythropoietin-alpha (rhEPOa) could act as such inducer. Design Cultured SCAP cells were exposed to rhEPOa and assessed for cell growth kinetics, viability and morphology, as well as their capacity to form capillary tubule structures in selected microenvironments. RT-PCR was used to monitor endothelial markers and activation of EPO/EPOR pathway signaling components; while gelatin zymographies to assess activation of MMP-2. Results rhEPOa treatment initially (48 h) accelerated cell proliferation and allowed SCAP to sprout micro-tubular structures. Morphological and biochemical differentiation was accompanied by activation of MMP-2 and upregulation of PECAM-1, VEGFR2, vWF and VE-cadherin/CDH5. SCAP expressed the cognate EPO-R, while rhEPOa-treated SCAP exhibited higher expression of molecules involved in EPO/EPOR pathway (EPOR and JAK2). Conclusion rhEPOa is capable of promoting endothelial transdifferentiation of SCAP which may be of clinical value in treating of ischemic disorders.
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Angiogenic Potential and Secretome of Human Apical Papilla Mesenchymal Stem Cells in Various Stress Microenvironments
Stem Cells and Development, 2015Co-Authors: Athina Bakopoulou, Aristeidis Kritis, Dimitrios Andreadis, Eleni Papachristou, Gabriele Leyhausen, Petros Koidis, Werner Geurtsen, Asterios S. TsiftsoglouAbstract:Stem cells from the Apical Papilla (SCAP) of human adult teeth are considered an accessible source of cells with angiogenic properties. The aims of this study were to investigate the endothelial transdifferentiation of SCAP, the secretion of pro- and antiangiogenic factors from SCAP, and the paracrine effects of SCAP when exposed to environmental stress to stimulate tissue damage. SCAP were exposed to serum deprivation (SD), glucose deprivation (GD), and oxygen deprivation/hypoxia (OD) conditions, individually or in combination. Endothelial transdifferentiation was evaluated by in vitro capillary-like formation assays, real-time polymerase chain reaction, western blot, and flow cytometric analyses of angiogenesis-related markers; secretome by antibody arrays and enzyme-linked immunosorbent assays (ELISA); and paracrine impact on human umbilical vein endothelial cells (HUVECs) by in vitro transwell migration and capillary-like formation assays. The short-term exposure of SCAP to glucose/oxygen deprivation ...
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comparative analysis of in vitro osteo odontogenic differentiation potential of human dental pulp stem cells dpscs and stem cells from the Apical Papilla scap
Archives of Oral Biology, 2011Co-Authors: Athina Bakopoulou, Gabriele Leyhausen, Petros Koidis, Werner Geurtsen, Asterios S. Tsiftsoglou, Joachim Volk, P. GarefisAbstract:Abstract Objective The aim of this study was to compare the in vitro osteo/odontogenic differentiation potential of mesenchymal stem cells (MSCs) derived from the dental pulp (dental pulp stem cells – DPSCs) or the Apical Papilla (stem cells from the Apical Papilla – SCAP) of permanent developing teeth. Design DPSCs and SCAP cultures were established from impacted third molars of young healthy donors at the stage of root development. Cultures were analysed for stem cell markers, including STRO-1, CD146, CD34 and CD45 using flow cytometry. Cells were then induced for osteo/odontogenic differentiation by media containing dexamethasone, KH 2 PO 4 and β-glycerophosphate. Cultures were analysed for morphology, growth characteristics, mineralization potential (Alizarin Red method) and differentiation markers (dentine sialophosphoprotein-DSPP, bone sialoprotein-BSP, osteocalcin-OCN, alkaline phosphatase-ALP), using immunocytochemistry and reverse transcriptase-polymerase chain reaction. Results All DPSCs and SCAP cultures were positive for STRO-1, CD146 and CD34, in percentages varying according to cell type and donor, but negative for CD45. Both types of MSCs displayed an active potential for cellular migration, organization and mineralization, producing 3D mineralized structures. These structures progressively expressed differentiation markers, including DSPP, BSP, OCN, ALP, having the characteristics of osteodentin. SCAP, however, showed a significantly higher proliferation rate and mineralization potential, which might be of significance for their use in bone/dental tissue engineering. Conclusions This study provides evidence that different types of dental MSCs can be used in tissue engineering/regeneration protocols as an approachable stem cell source for osteo/odontogenic differentiation and biomineralization that could be further applied for stem cell-based clinical therapies.
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Comparative analysis of in vitro osteo/odontogenic differentiation potential of human dental pulp stem cells (DPSCs) and stem cells from the Apical Papilla (SCAP)
Archives of Oral Biology, 2011Co-Authors: Athina Bakopoulou, Gabriele Leyhausen, Petros Koidis, Asterios S. Tsiftsoglou, Joachim Volk, P. Garefis, Werner GeurtsenAbstract:Abstract Objective The aim of this study was to compare the in vitro osteo/odontogenic differentiation potential of mesenchymal stem cells (MSCs) derived from the dental pulp (dental pulp stem cells – DPSCs) or the Apical Papilla (stem cells from the Apical Papilla – SCAP) of permanent developing teeth. Design DPSCs and SCAP cultures were established from impacted third molars of young healthy donors at the stage of root development. Cultures were analysed for stem cell markers, including STRO-1, CD146, CD34 and CD45 using flow cytometry. Cells were then induced for osteo/odontogenic differentiation by media containing dexamethasone, KH 2 PO 4 and β-glycerophosphate. Cultures were analysed for morphology, growth characteristics, mineralization potential (Alizarin Red method) and differentiation markers (dentine sialophosphoprotein-DSPP, bone sialoprotein-BSP, osteocalcin-OCN, alkaline phosphatase-ALP), using immunocytochemistry and reverse transcriptase-polymerase chain reaction. Results All DPSCs and SCAP cultures were positive for STRO-1, CD146 and CD34, in percentages varying according to cell type and donor, but negative for CD45. Both types of MSCs displayed an active potential for cellular migration, organization and mineralization, producing 3D mineralized structures. These structures progressively expressed differentiation markers, including DSPP, BSP, OCN, ALP, having the characteristics of osteodentin. SCAP, however, showed a significantly higher proliferation rate and mineralization potential, which might be of significance for their use in bone/dental tissue engineering. Conclusions This study provides evidence that different types of dental MSCs can be used in tissue engineering/regeneration protocols as an approachable stem cell source for osteo/odontogenic differentiation and biomineralization that could be further applied for stem cell-based clinical therapies.
