RESUMO
Camphorquinone (CQ) and resin monomers are included in dentin bonding agents (DBAs) and composite resin to restore tooth defects due to abrasion, crown fracture, or dental caries. DBAs, CQ, and bisphenol A-glycidyl methacrylate (BisGMA) applications influence the biological activities of the dental pulp. The current investigation aimed to delineate the effect of DBAs, CQ, and BisGMA on cathepsin L production/expression, lysosomal activity, and autophagy induction in human dental pulp cells (HDPCs). HDPCs were exposed to DBAs, CQ, or BisGMA with/without inhibitors for 24 h. Enzyme-linked immunosorbent assay was employed to determine the cathepsin L level in culture medium. The cell layer was utilized to measure cell viability by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl -tetrazolium bromide (MTT) assay. Real-time PCR was used to evaluate the mRNA expression. Western blotting or immunofluorescent staining was used to study protein expression. Lysosomal density was evaluated by lysotracker red staining. We found that DBAs, CQ, and BisGMA stimulated cathepsin L mRNA, protein expression, and production in HDPCs. In addition, CQ and BisGMA induced lysosomal activity, Beclin1, ATG12, LC3B, Bax, and p53 expression in HDPCs, indicating the stimulation of autophagy. Glutathione (GSH) prevented CQ- and BisGMA-induced cytotoxicity. Moreover, E64d, cathepsin L inhibitor (two cathepsin inhibitors), and Pifithrin-α (a p53 inhibitor) showed little preventive effect toward CQ- and BisGMA-induced cytotoxicity. Autophagy inhibitors (NH4Cl, Lys05) mildly enhanced the CQ- and BisGMA-induced cytotoxicity. These results indicate that DBAs stimulated cathepsin L, possibly due to their content of CQ and BisGMA that may induce cathepsin L in HDPCs. CQ and BisGMA stimulated lysosomal activity, autophagy, and apoptosis, possibly via induction of Beclin 1, ATG12, LC-3B, Bax, and p53 expression. In addition, CQ and BisGMA cytotoxicity was related to redox change and autophagy. These events are important role in pulpal changes after the restoration of tooth decay using CQ- and BisGMA-containing DBAs and resin composite.
Assuntos
Cárie Dentária , Proteína Supressora de Tumor p53 , Humanos , Bis-Fenol A-Glicidil Metacrilato , Catepsina L , Polpa Dentária , Proteína X Associada a bcl-2 , Resinas Compostas , Adesivos DentináriosRESUMO
INTRODUCTION: Basic fibroblast growth factor (bFGF) plays a critical role in odontoblast differentiation and dentin matrix deposition, thereby aiding pulpo-dentin repair and regeneration. OBJECTIVES: The purpose of this study was to clarify the effects of bFGF on plasminogen activation factors, TIMP-1), ALP; and SPARC (osteonectin) expression/production of stem cells from apical papilla (SCAP) in vitro; and the involvement of MEK/ERK, p38, Akt, and TAK1 signaling. METHODS: SCAP were exposed to bFGF with/without pretreatment and co-incubation with various signal transduction inhibitors (U0126, SB203580, LY294002, and 5Z-7-oxozeaenol). The expression of FGF receptors (FGFRs), PAI-1, uPA, p-ERK, p-TAK1, and p-p38 was analyzed via immunofluorescent staining. The gene expression and protein secretion of SCAP were determined via real-time PCR and ELISA. ALP activity was evaluated via ALP staining. RESULTS: SCAP expressed FGFR1, 2, 3, and 4. bFGF stimulated the PAI-1, uPA, uPAR, and TIMP-1 mRNA expression (p < 0.05). bFGF induced PAI-1, uPA, and soluble uPAR production (p < 0.05) but suppressed the ALP activity and SPARC production (p < 0.05) of SCAP. bFGF stimulated ERK, TAK1, and p38 phosphorylation of SCAP. U0126 (a MEK/ERK inhibitor) and 5Z-7-oxozeaenol (a TAK1 inhibitor) attenuated the bFGF-induced PAI-1, uPA, uPAR, and TIMP-1 expression and production of SCAP, but SB203580 (a p38 inhibitor) did not. LY294002, SB203580, and 5Z-7oxozeaenol could not reverse the inhibition of ALP activity caused by bFGF. Interestingly, U0126 and 5Z-7-oxozeaenol prevented the bFGF-induced decline of SPARC production (p < 0.05). CONCLUSION: bFGF may regulate fibrinolysis and matrix turnover via modulation of PAI-1, uPA, uPAR, and TIMP-1, but bFGF inhibited the differentiation (ALP, SPARC) of SCAP. These events are mainly regulated by MEK/ERK, p38, and TAK1. Combined use of bFGF and SCAP may facilitate pulpal/root repair and regeneration via regulation of the plasminogen activation system, migration, matrix turnover, and differentiation of SCAP.
Assuntos
Fosfatase Alcalina , Fator 2 de Crescimento de Fibroblastos , Fosfatase Alcalina/metabolismo , Fosfatase Alcalina/farmacologia , Butadienos , Fator 2 de Crescimento de Fibroblastos/metabolismo , Fator 2 de Crescimento de Fibroblastos/farmacologia , Lactonas , Sistema de Sinalização das MAP Quinases , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/farmacologia , Nitrilas , Osteonectina/metabolismo , Osteonectina/farmacologia , Plasminogênio/metabolismo , Plasminogênio/farmacologia , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Inibidor 1 de Ativador de Plasminogênio/farmacologia , Resorcinóis , Transdução de Sinais , Células-Tronco/metabolismo , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Inibidor Tecidual de Metaloproteinase-1/farmacologia , Zearalenona/administração & dosagemRESUMO
The 4-dimethylaminobenzoic acid ethyl ester (DMABEE) is an important co-initiator for resin polymerization in dental resinous materials. As a radical forming chemical with high lipophilicity, the genotoxicity and cytotoxicity of DMABEE deserve prudent investigation. In this study, we found that DMABEE reduced the viability and proliferation of Chinese hamster ovary (CHO-K1) cells in a dose-dependent manner, and altered cell morphology at higher concentrations. G0/G1 cell cycle arrest was induced by DMABEE at 0.25-0.75 mM, and cell proportion of sub-G0/G1 phase was significantly elevated at 1 mM while cell apoptosis was observed. Genotoxic effect was noted when cells were treated by 0.1 mM DMABEE, as revealed by increase of micronucleus formation. Reactive oxygen species overproduction was observed as cells treated with 0.75 and 1 mM, while elevation of intracellular glutathione was noticeable since 0.1 mM. Contrary to our expectation, pretreatment by N-acetyl-l-cysteine enhanced the toxicity of DMABEE on CHO-K1 cells. Catalase mildly reduced the toxic effect and carboxylesterase showed obvious ability to reverse the toxicity of DMABEE. These findings highlight the mechanism of DMABEE toxicity and provide clues for safety improvement of its application in clinical dental treatment.
Assuntos
Carboxilesterase/metabolismo , Fotoiniciadores Dentários/efeitos adversos , Fotoiniciadores Dentários/química , para-Aminobenzoatos/efeitos adversos , para-Aminobenzoatos/química , Animais , Apoptose/efeitos dos fármacos , Células CHO , Catalase/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Cricetulus , Dano ao DNA/efeitos dos fármacos , Glutationa/metabolismo , Humanos , Oxirredução , Polimerização , Espécies Reativas de Oxigênio/metabolismoRESUMO
BACKGROUND/PURPOSE: Interleukin 1 beta (IL-1ß) is a pro-inflammatory cytokine involved in the inflammatory processes of dental pulp. IL-8 and urokinase plasminogen activator (uPA) are two inflammatory mediators. However, the role of transforming growth factor beta-activated kinase-1 (TAK1) and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathways in responsible for the effects of IL-1ß on IL-8 and uPA expression/secretion of dental pulp cells are not clear. METHODS: Human dental pulp cells were exposed to IL-1ß with/without pretreatment with 5z-7-oxozeaneaeol (a TAK1 inhibitor) or U0126 (a MEK/ERK inhibitor). TAK1 activation was determined by immunofluorescent staining. The protein expression of IL-8 was tested by western blot. The expression of IL-8 and uPA mRNA was studied by reverse transcriptase-polymerase chain reaction (RT-PCR). The secretion of IL-8 and uPA was measured by enzyme-linked immunosorbent assay. RESULTS: Exposure of dental pulp cells to IL-1ß (0.1-10 ng/ml) stimulated IL-8 and uPA expression. IL-1ß also induced IL-8 and uPA secretion of dental pulp cells. IL-1ß stimulated p-TAK1 activation of pulp cells. Pretreatment and co-incubation of pulp cells by 5z-7oxozeaenol (1 and 2.5 µM) and U0126 (10 and 20 µM) prevented the IL-1ß-induced IL-8 and uPA expression. 5z-7oxozeaenol and U0126 also attenuated the IL-1ß-induced IL-8 and uPA secretion. CONCLUSION: IL-1ß is important in the pathogenesis of pulpal inflammatory diseases and repair via stimulation of IL-8 and uPA expression and secretion. These events are associated with TAK1 and MEK/ERK signaling. Blocking of TAK1 and MEK/ERK signaling has potential to control inflammation of dental pulp.
Assuntos
Polpa Dentária/citologia , Células Epiteliais/efeitos dos fármacos , Interleucina-1beta/farmacologia , Interleucina-8/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Fragmentos de Peptídeos/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Butadienos/farmacologia , Células Cultivadas , Inibidores Enzimáticos/farmacologia , Humanos , MAP Quinase Quinase Quinases/metabolismo , Nitrilas/farmacologia , Zearalenona/análogos & derivados , Zearalenona/farmacologiaRESUMO
BACKGROUND/PURPOSES: TGF-ß1 is an important growth factor that may influence the odontoblast differentiation and matrix deposition in the reactionary/reparative dentinogenesis to dental caries or other tooth injuries. TGF-ß1 exerts its effects through various signaling pathways, such as Smads and MAPKs. Cyclooxygenase-2 (COX-2) is a membrane-associated enzyme that produces prostaglandin E2 (PGE2) at sites of pulpal injury and inflammation, which leads to tissue swelling, redness and pain. The purposes of this study were to investigate the differential signal transduction pathways of TGF-ß1 that mediate COX-2 stimulation and PGE2 production in dental pulp cells. METHODS: Pulp cells were exposed to TGF-ß1 with/without SB431542 (an ALK5/Smad2 inhibitor) and U0126 (a MEK/ERK inhibitor). MTT assay was used to estimate cell viability. Enzyme-linked immunosorbent assay (ELISA) was used for measurement of PGE2 levels. RT-PCR and western blot were used to determined COX-2 mRNA and protein, respectively. RESULTS: Exposure to TGF-ß1 (1-10 ng/ml) increased the COX-2 mRNA and protein level of cultured pulp cells. Exposure to TGF-ß1 (0.1-10 ng/mL) significantly stimulated PGE2 production of dental pulp cells. Under the pretreatment of SB431542, the stimulatory effect of TGF-ß1 on COX-2 level of pulp cells was inhibited. Similarly, U0126 also partly inhibited the TGF-ß1-induced COX-2 expression. CONCLUSION: TGF-ß1 increased the COX-2 and PGE2 level of cultured pulp cells. The effect of TGF-ß1 on COX-2 protein expression was associated with ALK5/Smad2/3 and MEK/ERK pathways. These events are important in the early inflammation, repair and regeneration of dental pulp in response to injury.
Assuntos
Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Células Epiteliais/citologia , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta1/farmacologia , Benzamidas/farmacologia , Butadienos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ciclo-Oxigenase 2/genética , Polpa Dentária/citologia , Polpa Dentária/efeitos dos fármacos , Dioxóis/farmacologia , Células Epiteliais/efeitos dos fármacos , Humanos , Nitrilas/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Proteína Smad2/metabolismoRESUMO
Camphorquinone (CQ) is a popularly-used photosensitizer in composite resin restoration. In this study, the effects of CQ on cytotoxicity and inflammation-related genes and proteins expression of pulp cells were investigated. The role of reactive oxygen species (ROS), ATM/Chk2/p53 and hemeoxygenase-1 (HO-1) and MEK/ERK signaling was also evaluated. We found that ROS and free radicals may play important role in CQ toxicity. CQ (1 and 2 mM) decreased the viability of pulp cells to about 70% and 50% of control, respectively. CQ also induced G2/M cell cycle arrest and apoptosis of pulp cells. The expression of type I collagen, cdc2, cyclin B, and cdc25C was inhibited, while p21, HO-1 and cyclooxygenase-2 (COX-2) were stimulated by CQ. CQ also activated ATM, Chk2, and p53 phosphorylation and GADD45α expression. Besides, exposure to CQ increased cellular ROS level and 8-isoprostane production. CQ also stimulated COX-2 expression and PGE2 production of pulp cells. The reduction of cell viability caused by CQ can be attenuated by N-acetyl-L-cysteine (NAC), catalase and superoxide dismutase (SOD), but can be promoted by Zinc protoporphyin (ZnPP). CQ stimulated ERK1/2 phosphorylation, and U0126 prevented the CQ-induced COX-2 expression and prostaglandin E2 (PGE2) production. These results indicate that CQ may cause cytotoxicity, cell cycle arrest, apoptosis, and PGE2 production of pulp cells. These events could be due to stimulation of ROS and 8-isoprostane production, ATM/Chk2/p53 signaling, HO-1, COX-2 and p21 expression, as well as the inhibition of cdc2, cdc25C and cyclin B1. These results are important for understanding the role of ROS in pathogenesis of pulp necrosis and pulpal inflammation after clinical composite resin filling.
Assuntos
Cânfora/análogos & derivados , Polpa Dentária/efeitos dos fármacos , Polpa Dentária/metabolismo , Dinoprostona/biossíntese , Adulto , Apoptose/efeitos dos fármacos , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Cânfora/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Quinase do Ponto de Checagem 2/metabolismo , Polpa Dentária/citologia , Polpa Dentária/enzimologia , Dinoprosta/análogos & derivados , Dinoprosta/biossíntese , Heme Oxigenase-1/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Cultura Primária de Células , Espécies Reativas de Oxigênio/metabolismo , Adulto JovemRESUMO
Catechol (benzenediol) is present in plant-derived products, such as vegetables, fruits, coffee, tea, wine, areca nut and cigarette smoke. Because platelet dysfunction is a risk factor of cardiovascular diseases, including stroke, atherosclerosis and myocardial infarction, the purpose of this study was to evaluate the anti-platelet and anti-inflammatory effect of catechol and its mechanisms. The effects of catechol on cyclooxygenase (COX) activity, arachidonic acid (AA)-induced aggregation, thromboxane B2 (TXB2) production, lactate dehydrogenase (LDH) release, reactive oxygen species (ROS) production and extracellular signal-regulated kinase (ERK)/p38 phosphorylation were determined in rabbit platelets. In addition, its effect on IL-1ß-induced prostaglandin E2 (PGE2) production by fibroblasts was determined. The ex vivo effect of catechol on platelet aggregation was also measured. Catechol (5-25 µM) suppressed AA-induced platelet aggregation and inhibited TXB2 production at concentrations of 0.5-5 µM; however, it showed little cytotoxicity and did not alter U46619-induced platelet aggregation. Catechol (10-50 µM) suppressed COX-1 activity by 29-44% and COX-2 activity by 29-50%. It also inhibited IL-1ß-induced PGE2 production, but not COX-2 expression of fibroblasts. Moreover, catechol (1-10 µM) attenuated AA-induced ROS production in platelets and phorbol myristate acetate (PMA)-induced ROS production in human polymorphonuclear leukocytes. Exposure of platelets to catechol decreased AA-induced ERK and p38 phosphorylation. Finally, intravenous administration of catechol (2.5-5 µmole/mouse) attenuated ex vivo AA-induced platelet aggregation. These results suggest that catechol exhibited anti-platelet and anti-inflammatory effects, which were mediated by inhibition of COX, ROS and TXA2 production as well as ERK/p38 phosphorylation. The anti-platelet effect of catechol was confirmed by ex vivo analysis. Exposure to catechol may affect platelet function and thus cardiovascular health.
Assuntos
Catecóis/farmacologia , Inibidores de Ciclo-Oxigenase/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Espécies Reativas de Oxigênio/antagonistas & inibidores , Tromboxano A2/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Animais , Ácido Araquidônico/farmacologia , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Humanos , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Fosforilação/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Testes de Função Plaquetária/métodos , Prostaglandina-Endoperóxido Sintases/metabolismo , Coelhos , Espécies Reativas de Oxigênio/metabolismo , Tromboxano A2/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
AIMS: Chewing of betel quid (BQ) increases the risk of oral cancer and oral submucous fibrosis (OSF), possibly by BQ-induced toxicity and induction of inflammatory response in oral mucosa. METHODS: Primary gingival keratinocytes (GK cells) were exposed to areca nut (AN) components with/without inhibitors. Cytotoxicity was measured by 3-(4,5-dimethyl- thiazol- 2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. mRNA and protein expression was evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) and western blotting. PGE2/PGF2α production was measured by enzyme-linked immunosorbent assays. RESULTS: Areca nut extract (ANE) stimulated PGE2/PGF2α production, and upregulated the expression of cyclooxygenase-2 (COX-2), cytochrome P450 1A1 (CYP1A1) and hemeoxygenase-1 (HO-1), but inhibited expression of keratin 5/14, cyclinB1 and cdc25C in GK cells. ANE also activated epidermal growth factor receptor (EGFR), Src and Ras signaling pathways. ANE-induced COX-2, keratin 5, keratin 14 and cdc25C expression as well as PGE2 production were differentially regulated by α-naphthoflavone (a CYP 1A1/1A2 inhibitor), PD153035 (EGFR inhibitor), pp2 (Src inhibitor), and manumycin A (a Ras inhibitor). ANE-induced PGE2 production was suppressed by piper betle leaf (PBL) extract and hydroxychavicol (two major BQ components), dicoumarol (a NAD(P)H: Quinone Oxidoreductase--NQO1 inhibitor) and curcumin. ANE-induced cytotoxicity was inhibited by catalase and enhanced by dicoumarol, suggesting that AN components may contribute to the pathogenesis of OSF and oral cancer via induction of aberrant differentiation, cytotoxicity, COX-2 expression, and PGE2/PGF2α production. CONCLUSIONS: CYP4501A1, reactive oxygen species (ROS), EGFR, Src and Ras signaling pathways could all play a role in ANE-induced pathogenesis of oral cancer. Addition of PBL into BQ and curcumin consumption could inhibit the ANE-induced inflammatory response.
Assuntos
Areca/química , Expressão Gênica/efeitos dos fármacos , Queratinócitos/metabolismo , Extratos Vegetais/toxicidade , Células Cultivadas , Curcumina/farmacologia , Ciclina B1/metabolismo , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Dicumarol/farmacologia , Dinoprostona/biossíntese , Receptores ErbB/metabolismo , Gengiva/patologia , Heme Oxigenase-1/metabolismo , Humanos , Queratinócitos/efeitos dos fármacos , Queratinas/genética , Queratinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Fosfatases cdc25/genética , Fosfatases cdc25/metabolismo , Proteínas ras/metabolismo , Quinases da Família src/metabolismoRESUMO
The toxic effect of urethane dimethacrylate (UDMA), a major dental resin monomer, on human dental pulp is not fully clear. In this study, we investigated the influence of UDMA on the cytotoxicity, cell cycle distribution, apoptosis and related gene expression of dental pulp cells. The role of reactive oxygen species, hemeoxygenase-1 (HO-1) and carboxylesterase (CES) in UDMA cytotoxicity, was evaluated. UDMA induced morphological changes of pulp cells and decreased cell viability by 29-49% at concentrations of 0.1-0.35 mM. UDMA induced G0/G1, G2/M cell cycle arrest and apoptosis. The expression of cdc2, cyclinB1 and cdc25C was inhibited by UDMA. Moreover, UDMA stimulated COX-2, HO-1 and CES2 mRNA expression of pulp cells. The cytotoxicity of UDMA was attenuated by N-acetyl-l-cysteine, catalase and esterase, but was enhanced by Zn-protoporphyrin (HO-1 inhibitor), BNPP (CES inhibitor) and loperamide (CES2 inhibitor). Exposure of UDMA may potentially induce the inflammation and toxicity of dental pulp. These findings are important for understanding the clinical response of human pulp to resin monomers after operative restoration and pulp capping, and also provide clues for improvement of dental materials.
Assuntos
Carboxilesterase/metabolismo , Ciclo-Oxigenase 2/metabolismo , Polpa Dentária/citologia , Polpa Dentária/enzimologia , Heme Oxigenase (Desciclizante)/metabolismo , Metacrilatos/farmacologia , Poliuretanos/farmacologia , Acetilcisteína/farmacologia , Antioxidantes/farmacologia , Carboxilesterase/genética , Catalase/metabolismo , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Polpa Dentária/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Heme Oxigenase (Desciclizante)/genética , Humanos , Cinética , Loperamida/farmacologia , Nitrofenóis/farmacologia , Protoporfirinas/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
Monomers released from resin-containing products may cause various adverse effects. Urethane dimethacrylate (UDMA) is a principal resin monomer and also a major component released from various dental resin materials. Thus the toxic effects and mechanisms should be elucidated for improving of its safety use. Here we investigated the effects of UDMA on the growth, cell cycle progression, reactive oxygen species (ROS) production and glutathione (GSH) alteration in CHO-K1 cells, and the preventive effects by antioxidants (NAC and catalase) were also evaluated. UDMA elicited growth inhibition (>0.025 mm) of CHO-K1 cells in a clearly dose-dependent manner. Cell cycle perturbation and ROS overproduction were also observed. A 0.1 mm UDMA-induced S-phase cell cycle arrest and ROS accumulation. Cell apoptosis and necrosis became significant when UDMA concentration was 0.25 mm. GSH depletion occurred at cells treated with 0.25 mm UDMA, a highly cytotoxic concentration at which point myriad cells were under apoptosis or necrosis. Thus GSH depletion can be crucial for the death of CHO-K1 cells. Furthermore NAC (0.5-10 mm) and catalase (250-1000 U/ml) obviously attenuated the UDMA-induced toxicity by reducing ROS generation and cell cycle disturbance, and the effects were dose-related. These results suggest that UDMA toxicity is associated with ROS production, GSH depletion, cell cycle disturbance and cell apoptosis/necrosis.
Assuntos
Metacrilatos/efeitos adversos , Poliuretanos/efeitos adversos , Animais , Apoptose/efeitos dos fármacos , Células CHO , Catalase/metabolismo , Ciclo Celular/efeitos dos fármacos , Cricetinae , Cricetulus , Glutationa/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
BACKGROUND/PURPOSE: Although the general profile of oral biopsies from Asian children has been reported, it was still worth examining whether there were racial and geographic variations in the categories and incidence of pediatric oral lesions. This retrospective study mainly evaluated the categories and incidence of biopsied oral lesions in Taiwanese pediatric patients. METHODS: Biopsy records of all oral lesions from pediatric patients, aged 0-14 years, in the files of the Department of Pathology, National Taiwan University Hospital from 1988 to 2007 were evaluated. The patients were divided into three age groups (0-5, 6-10, and 11-14 years), and the oral lesions were classified into four main categories: inflammatory and reactive, cystic, neoplastic, and other lesions. RESULTS: Of a total of 11,986 biopsied oral lesions, 797 (6.6%) were found in pediatric patients. The most common oral lesions were inflammatory and reactive (45.5%), followed by neoplastic (23.5%), cystic (22.2%), and other (8.8%) lesions. The majority of oral biopsies (47.3%) were taken from patients in the 11-14 years age group. Of the 187 oral neoplastic lesions, 178 (95%) were benign and nine (5%) were malignant, including two premalignant lesions. The maxilla (66 cases) and the mandible (61 cases) were the two most common sites for pediatric neoplastic lesions. The top five oral lesions in pediatric patients were mucous extravasation phenomenon (195 cases), dentigerous cyst (84 cases), odontoma (83 cases), radicular cyst (38 cases), and dental follicle (26 cases). CONCLUSION: The mucous extravasation phenomenon, odontoma, or dentigerous cyst was the most common inflammatory and reactive, neoplastic, or cystic lesion, respectively, in pediatric patients. The relatively high incidence of inflammatory and reactive lesions in pediatric patients implies the importance of stringent oral hygiene in children. Most oral neoplastic lesions in pediatric patients are benign, and malignant oral tumors rarely occur in pediatric patients.
Assuntos
Mucosa Bucal/patologia , Adolescente , Biópsia , Criança , Pré-Escolar , Cistos/epidemiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Neoplasias Bucais/epidemiologia , Lesões Pré-Cancerosas/epidemiologia , Estudos Retrospectivos , Taiwan/epidemiologiaRESUMO
Epidemiological studies have shown a strong association between environmental exposure to betel quid (BQ) and oral cancer. Areca nut (AN), an ingredient of BQ, contains genotoxic and mutagenic compounds. In this study, we found that AN extract (ANE) inhibited the growth of Chinese hamster ovary cells (CHO-K1) in a dose- and time-dependent manner. Intracellular reactive oxygen species (ROS) levels and micronuclei (MN) frequency were significantly increased following ANE treatment in CHO-K1 cells. Addition of catalase markedly inhibited ANE-induced MN formation, indicating that ANE-induced genotoxicity was correlated with intracellular H(2)O(2). Incubation of CHO-K1 cells with ANE (400-800 microg/ml) for 24 hr caused G2/M arrest, and prolonged exposure to ANE (800 microg/ml) significantly induced cell death. Surprisingly, ANE itself caused cytokinesis failure and subsequent increase in binucleated cell formation. Coexposure to catalase (2,000 U/ml) and ANE (800 microg/ml) reduced the generation of binucleated cells, indicating that ANE-induced cytokinesis failure was associated with oxidative stress. Following prolonged exposure to ANE, an accumulation of hyperploid/aneuploid cells concomitant with bi-, micro- or multinucleated cells was found. In summary, our results demonstrate that ANE exposure to CHO-K1 cells caused increased MN frequency, G2/M arrest, cytokinesis failure, and an accumulation of hyperploid/aneuploid cells. These events are associated with an increase in intracellular H(2)O(2) level and actin filament disorganization.
Assuntos
Actinas/metabolismo , Areca/química , Citocinese/efeitos dos fármacos , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Extratos Vegetais/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Animais , Células CHO , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cricetinae , Cricetulus , Peróxido de Hidrogênio/metabolismo , Extratos Vegetais/químicaRESUMO
Incontinentia pigmenti (IP) is a rare X-linked dominant inherited disorder which has a variety of ectodermal aberrations. Skin hyperpigmentation is the most characteristic feature of IP. However, extracutaneous anomalies involving dentition, hair, eyes, and central nervous system are also found. The dental anomalies reported include peg-shaped or malformed teeth, hypodontia, delayed eruption, and impacted tooth. This report describes the dental anomalies in 2 IP patients who had the characteristic features of skin hyperpigmentation. One was a 13-year-old girl who had slender cone-shaped permanent anterior teeth, hypodontia, and delayed eruption of teeth which are characteristic dental anomalies in an IP patient. The other was a 10-year-old girl who only had 2 tulip-shaped maxillary permanent central incisors with shorter tapering roots but no congenital missing teeth or delayed eruption of teeth. Our findings suggest that IP may present a broad variation of dental anomalies individually. However, the characteristic finding of permanent anterior teeth with a longer crown and a shorter root found in both of our IP patients may be worthy of consideration in the differential diagnosis of IP.
Assuntos
Incontinência Pigmentar/patologia , Anormalidades Dentárias/patologia , Adolescente , Criança , Cromossomos Humanos X , Feminino , Ligação Genética , Humanos , Incontinência Pigmentar/genéticaRESUMO
2-Hydroxy-ethyl methacrylate (HEMA) is the major component released from resin-modified glass ionomer cements and dental adhesives. Human tissues mainly affected by HEMA are oral epithelium and dental pulp. We treated human gingival epithelial S-G cells and pulp fibroblasts (HPF) with various concentrations of HEMA, to evaluate its effects on cell growth, cell cycle progression, intracellular glutathione (GSH) level and reactive oxygen species (ROS) production. HEMA-induced growth inhibition in HPF and S-G cells in a dose-dependent manner, which may be partially explained by induction of cell cycle perturbation. G(2)/M phase arrest was noted after exposure of HPF to 5 and 10mm of HEMA, concomitant with glutathione depletion and ROS production. S-phase arrest occurred in S-G cells when treated with 2.5 and 5mm, while at 10mm a sub-G(0)/G(1) peak was noted, indicating the potential induction of apoptosis. GSH depletion was marked in S-G cells only at concentrations of 5 and 10mm, but excessive ROS production was noted at concentration of 1mm and rose with dose increase between 1 and 5mm, then lessened at 10mm. This suggested that the increase of ROS in S-G cells was not mainly caused by GSH depletion. These results helped to define the mechanism of the cytotoxicity caused by HEMA.