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Pulp Cells (pulp + cell)
Kinds of Pulp Cells Selected AbstractsDentinogenic potential of the dental pulp: facts and hypothesesENDODONTIC TOPICS, Issue 1 2007DIMITRIOS TZIAFAS The aim of the present article is to discuss observations and hypotheses from different experimental approaches on the biological mechanisms underlying initiation of tertiary dentin formation and therapeutic control of pulp,dentinal regeneration. The specific dentinogenic potential of dental pulp cells in up-regulating the biosynthetic activity of primary odontoblasts (reactionary dentinogenesis) and differentiation into odontoblast-like cells (reparative dentinogenesis) is described. The role of biologically active matrices and molecules as signaling factors in the expression of the dentinogenic potential of dental pulp cells, in numerous ex vivo and in vivo models, is reviewed. Data are focused on the mechanisms by which the signaling molecules, in the presence of the appropriate pulp microenvironment and specific mechanical support, can induce competent pulpal cells in the acquisition of odontoblast-like cell phenotype and reparative dentin formation. The ability of tissue engineering to stimulate reconstruction of the amputated pulp,dentin complex offers exciting opportunities for the future. Advances in molecular biology and bioengineering research might thus be integrated into the clinical problems of endodontology. Received 13 February 2009; accepted 2 September 2009. [source] Neurosphere generation from dental pulp of adult rat incisorEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2008Ryo Sasaki Abstract Dental pulp is a potential source of cells that can be used in cell replacement therapy for various nervous system disorders. Here we report that adult rat dental pulp cells have the ability to form neurospheres when cultured in serum-free culture medium on super-hydrophilic plates. The cells within small spheres continued to grow, and the dental pulp-derived cells generated large spheres. Sphere formation was dependent on exogenously supplied basic-fibroblast growth factor, but not on epidermal growth factor, and the formation and growth of dental pulp-derived spheres were negatively regulated by transforming growth factor-,. Plating cells that were dissociated from spheres on an adhesive substrate resulted in differentiation into Tuj1- and MAP2-positive neuronal cells. Analysis of the three-dimensional structure of dental pulp-derived spheres shows that they contained nestin-positive progenitors, Tuj1-positive neuronal cells and S100-positive glial cells. We found that spheres contained CD81 (TAPA1) and nestin double-positive cells, and identified a small population of CD81 and nestin double-positive cells in the odontoblast layer of the dental pulp. Flow cytometric analysis showed that CD81-positive cells were enriched in the spheres compared with the dental pulp tissue. Bromodeoxyuridine (BrdU) staining showed that nestin- and BrdU-positive cells were located only in the apical portion of the dental pulp, and the apical portion produced a large number of large-sized spheres. These data suggest that the CD81 and nestin double-positive cells localized in the odontoblast layer of the apical portion of the dental pulp may have the ability to grow and form neurospheres. [source] The location and characteristics of two populations of dental pulp cells affect tooth developmentEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2 2009Yoshinori Sumita This study investigated the characteristics of two dental pulp cell populations during the early stages of crown formation in porcine teeth. A transplantation method was developed to reproduce epithelial cell,mesenchymal cell interactions during odontogenesis (tooth development). The technique allowed two types of cells/tissue to be combined in vivo. Populations of cells localized in the cervical loop epithelium region, dental pulp horn, and dental pulp core chambers were isolated and dissociated into single cells. Each population was examined for its gene-expression pattern using both semiquantitative and quantitative reverse transcription,polymerase chain reaction (RT-PCR) analyses, and for its tissue-formation capability by combining the cervical loop epithelial cells with either pulp horn cells or pulp core cells on biodegradable collagen scaffolds that were subsequently examined using histology and immunohistology. Gene-expression patterns showed that pulp horn cells were more mature than pulp core cells. Cervical loop epithelial cells combined with pulp horn cells mainly reconstituted dentin,cementum structures. By contrast, cervical loop epithelial cells combined with pulp core cells reconstituted enamel,dentin structures. These results suggest that mesenchymal cells residing in a specific location of the pulp possess a specific tissue-formation potential when combined with epithelial cells. [source] Prostaglandin F2, stimulates MEK-ERK signalling but decreases the expression of alkaline phosphatase in dental pulp cellsINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2010M. C. Chang Chang MC, Chen YJ, Lee MY, Lin LD, Wang TM, Chan CP, Tsai YL, Wang CY, Lin BR, Jeng JH. Prostaglandin F2, stimulates MEK-ERK signalling but decreases the expression of alkaline phosphatase in dental pulp cells. International Endodontic Journal, 43, 461,468, 2010. Abstract Aim, To study prostaglandin F2, (PGF2,) receptor expression and downstream signalling in cultured human dental pulp cells and the effect of PGF2, on the alkaline phosphatase (ALP) activity of dental pulp cells. Methodology, Human dental pulp cells were cultured and exposed to PGF2,. The expression of PGF2, (FP) receptors was analysed by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. The activation of extracellular regulated kinase (ERK) and cAMP responsive element binding protein/activating transcription factor-1 (CREB/ATF-1) signalling was determined by Western blotting. The expression of ALP in pulp cells after exposure to PGF2, was evaluated by ALP staining and PCR. Results, Dental pulp cells expressed FP receptor mRNA and protein. Exposure to PGF2, revealed little cytotoxicity to pulp cells. PGF2, induced both ERK and CREB/ATF-1 phosphorylation in pulp cells. Exposure to PGF2, (>1 ,mol L,1) further decreased the ALP activity and mRNA expression. However, U0126 (an inhibitor of MEK1) showed little preventive effect on the decline of ALP activity in dental pulp cells by PGF2,. Conclusion, PGF2, may potentially activate FP receptors leading to ERK/CREB-ATF-1 activation during its production in inflamed dental pulp. PGF2, attenuated the ALP activity of pulp cells possibly via pathways not solely by MEK/ERK activation. PGF2, is a contributing factor of pulpal inflammation by regulating the activities of pulp cells. [source] Localization of substance P-induced upregulated interleukin-8 expression in human dental pulp explantsINTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2008G. T.-J. Abstract Aim, To localize ex vivo expression of interleukin-8 (IL-8) induced by substance P (SP) in human dental pulps. Methodology, Intact caries-free, freshly extracted third molars (n = 20) were collected from patients (15,25 years old). The teeth were split and pulpal tissue was obtained and stored in Dulbecco's modified Eagle medium. Human dental pulp tissue explants were stimulated with SP. Expression of IL-8 in pulp explants was detected and localized by immunohistochemistry. Results, Moderated IL-8 immunoreactivities were detected mainly in the cell-rich zone in pulp tissues 12 h after tumour necrosis factor alpha (TNF-,) stimulation (positive controls), whereas only weak IL-8 expression was observed in tissues stimulated with SP at the same time interval. These data did not differ from those in negative controls. Increased IL-8 expression in pulp explants after 24 h of SP stimulation was noted compared with negative controls and located in fibroblast-like cells, blood vessel-associated cells and extracellular matrix in the central zone and cell-rich zone of pulp explants. Tissues stimulated with TNF-, for 24 h (positive controls) revealed weak IL-8 immunoreactivities with altered cell morphology. Conclusions, Substance P induces IL-8 expression and was located in fibroblast-like pulp cells, blood vessel-associated cells and extracellular matrix of human dental explants. These data support the hypothesis that neuropeptide (SP) coordinates the modulation of pulpal inflammation via up-regulating chemokine IL-8. [source] Examination of the signal transduction pathways leading to upregulation of tissue type plasminogen activator by Porphyromonas endodontalis in human pulp cellsINTERNATIONAL ENDODONTIC JOURNAL, Issue 12 2005F.-M. Huang Abstract Aim, To investigate the tissue type plasminogen activator (t-PA) activity in human pulp cells stimulated with Porphyromonas endodontalis (P. endodontalis) in the absence or presence of p38 inhibitor SB203580, mitogen-activated protein kinase kinase (MEK) inhibitor U0126 and phosphatidylinositaol 3-kinase (PI3K) inhibitor LY294002. Methodology, The supernatants of P. endodontalis were used to evaluate t-PA activity in human pulp cells using casein zymography and enzyme-linked immunosorbent assay (ELISA). Furthermore, to search for possible signal transduction pathways, SB203580, U0126 and LY294002 were added to test how they modulated the t-PA activity. Results, The main casein secreted by human pulp cells migrated at 70 kDa and represented t-PA. Secretion of t-PA was found to be stimulated with P. endodontalis during 2-day cultured period (P < 0.05). From the results of casein zymography and ELISA, SB203580 and U0126 significantly reduced the P. endodontalis stimulated t-PA production respectively (P < 0.05). However, LY294002 lacked the ability to change the P. endodontalis stimulated t-PA production (P > 0.05). Conclusions,Porphyromonas endodontalis enhances t-PA production in human pulp cells, and the signal transduction pathways p38 and MEK are involved in the inhibition of t-PA. [source] Immunolocalization of bone extracellular matrix proteins (type I collagen, osteonectin and bone sialoprotein) in human dental pulp and cultured pulp cellsINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2003J. M. Q. Garcia Abstract Aim, To simultaneously analyse the expression of type I collagen, osteonectin and bone sialoprotein (BSP) in human dental pulp of different ages. Methodology, Cultured dental pulp fibroblasts (FP1 cell line), pulps from dental germs with incomplete root formation (n = 4) and pulps of erupted teeth with total root formation (n = 4) were used. Bone proteins were searched by immunohistochemistry and immunofluorescence using polyclonal antibodies and compared among the three groups assessed. Results, Immunohistochemistry detected the three proteins in dental pulp tissue, as it labelled extracellular matrix, predentine and odontoblasts. The BSP label was weaker, when compared to both type I collagen and osteonectin. The presence of type I collagen was more evident in pulps from erupted teeth, when compared to germ dental pulps. On the other hand, a strong expression of osteonectin in germ dental pulps was observed. Conclusions, Regardless of the degree of maturation, dental pulps present type I collagen, osteonectin and BSP in the extracellular matrix (ECM) and in the odontoblastic layer. Thus, the results suggest that these proteins are related to the production and mineralization of dentine. [source] Cytotoxicity of dentine-bonding agents on human pulp cells in vitroINTERNATIONAL ENDODONTIC JOURNAL, Issue 11 2002F.-M. Huang No abstract is available for this article. [source] Effects of sequential exposure to lipopolysaccharide and heat stress on dental pulp cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2006Chiaki Kitamura Abstract In the present study, we examined the effects of sequential exposure to bacterial lipopolysaccharide (LPS) and heat stress on dental pulp cells. LPS induced the proliferation of pulp cells through the activation of p38 MAPK. HSP27 was expressed in cells with or without LPS during the entire period of heat stress, while transiently phosphorylated by short-term heat stress. In LPS-treated cells, short-term heat stress also induced the phosphorylation of HSF1. The immediate phosphorylation of HSF1 and HSP27 in LPS-treated cells by short-term heat stress occurred dependent on the activation of p38 MAPK. However, with long-term heat stress, the activation of HSF1 and induction of HSP27 occurred independent of p38 MAPK. Further, full activation of Akt in LPS-treated cells was immediately induced by short-term heat stress and lasted during the entire period of heat stress. I,B, was induced and phosphorylated throughout sequential exposure to LPS and heat stress. These results suggest that LPS has the unique effects on the cytoprotection and the cell death of pulp cells during heat stress through the modification and the activation of heat stress responsive molecules, HSF1 and HSP27, and cell survival molecules, Akt and NF-,B/I,B,. J. Cell. Biochem. 99: 797,806, 2006. © 2006 Wiley-Liss, Inc. [source] Expression of Notch signalling-related genes in normal and differentiating rat dental pulp cellsAUSTRALIAN ENDODONTIC JOURNAL, Issue 2 2010Hantang Sun dds Abstract Notch signalling is of fundamental importance to various processes during embryonic development and in adults. The possible role of Hey1, an important Notch signalling component, in odontoblast differentiation was evaluated in this study. Primary cultured dental pulp cells, derived from upper incisors of 5-week-old Wistar rats, were placed in ,-modification of Eagle's minimal essential medium supplemented with 10% Fetal Bovine Serum (FBS), and ascorbic acid (AA) and ,-glycerophosphate (,-GP), with or without dexamethasone, and cultured on dishes coated with collagen type IA for 7 days. Conventional and real-time Polymerase Chain Reaction (PCR) was performed to determine the expression of Notch-related genes and dentin sialophosphoprotein as a marker of odontoblast differentiation. Dentin sialophosphoprotein and Hey1 expression was significantly increased and decreased in the presence of AA + ,-GP compared with controls, respectively. These findings suggest that Hey1 may be a negative regulator in odontoblast differentiation. [source] | |||||||||||||