Apical Papilla - Explore the Science & Experts | ideXlab

Scan Science and Technology

Contact Leading Edge Experts & Companies

Apical Papilla

The Experts below are selected from a list of 1431 Experts worldwide ranked by ideXlab platform

Apical Papilla – Free Register to Access Experts & Abstracts

Anibal R Diogenes – One of the best experts on this subject based on the ideXlab platform.

  • Does Apical Papilla survive and develop in Apical periodontitis presence after regenerative endodontic procedures
    Applied Sciences, 2019
    Co-Authors: Paulo Palma, Anibal R Diogenes, João Martins, Patrícia Diogo, Diana Sequeira, João Carlos Ramos, João Miguel Santos
    Abstract:

    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.

  • Direct and Indirect Effect of Chlorhexidine on Survival of Stem Cells from the Apical Papilla and Its Neutralization
    Journal of Endodontics, 2019
    Co-Authors: Matthias Widbiller, Riyadh I. Althumairy, Anibal R Diogenes
    Abstract:

    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.

  • Survival of the Apical Papilla and Its Resident Stem Cells in a Case of Advanced Pulpal Necrosis and Apical Periodontitis
    Journal of Endodontics, 2017
    Co-Authors: Vanessa Chrepa, Brandon Pitcher, Michael A. Henry, Anibal R Diogenes
    Abstract:

    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.

George T.-j. Huang – One of the best experts on this subject based on the ideXlab platform.

  • 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, 2015
    Co-Authors: Jing-yi Liu, Xue Chen, Lin Yue, George T.-j. Huang, Xiao-ying Zou
    Abstract:

    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.

  • 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, 2015
    Co-Authors: Jing-yi Liu, Xue Chen, Lin Yue, George T.-j. Huang, Xiao-ying Zou
    Abstract:

    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.

  • NOTCH3 is expressed in human Apical Papilla and in subpopulations of stem cells isolated from the tissue.
    Genes & Diseases, 2015
    Co-Authors: Mohamed Jamal, Sherif M. Karam, Sami Chogle, George T.-j. Huang
    Abstract:

    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.

J. Zhang – One of the best experts on this subject based on the ideXlab platform.

  • 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, 2017
    Co-Authors: Y. Zhu, Yan-hua Liang, J. Zhang
    Abstract:

    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.

  • 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, 2016
    Co-Authors: Y. Zhu, Yan-hua Liang, J. Zhang
    Abstract:

    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 

  • Nuclear Factor I-C promotes proliferation and differentiation of Apical Papilla-derived human stem cells in vitro.
    Experimental Cell Research, 2015
    Co-Authors: J. Zhang, Zhongying Niu, Paul R. Cooper, Zhihua Wang, Yong Jiang, Zhirong Luo, Anthony J. Smith
    Abstract:

    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.