RESUMEN
BACKGROUND/PURPOSE: The signaling mechanisms for Porphyromonas gingivalis lipopolysaccharide (PgLPS)-induced inflammation in human dental pulp cells are not fully clarified. This in vitro study aimed to evaluate the involvement of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in PgLPS-induced pulpal inflammation. METHODS: Human dental pulp cells (HDPCs) were challenged with PgLPS with or without pretreatment and coincubation with a PI3K/Akt inhibitor (LY294002). The gene or protein levels of PI3K, Akt, interleukin (IL)-6, IL-8, alkaline phosphatase (ALP), osteocalcin and osteonectin were analyzed by reverse transcription polymerase chain reaction (PCR), real-time PCR, western blotting, and immunofluorescent staining. In addition, an enzyme-linked immunosorbent assay was used to analyze IL-6 and IL-8 levels in culture medium. RESULTS: In response to 5 µg/ml PgLPS, IL-6, IL-8, and PI3K, but not Akt mRNA expression of HDPCs, was upregulated. IL-6, IL-8, PI3K, and p-Akt protein levels were stimulated by 10-50 µg/ml of PgLPS in HDPCs. PgLPS also induced IL-6 and IL-8 secretion at concentrations higher than 5 µg/ml. Pretreatment and co-incubation by LY294002 attenuated PgLPS-induced IL-6 and IL-8 mRNA expression in HDPCs. The mRNA expression of ALP, but not osteocalcin and osteonectin, was inhibited by higher concentrations of PgLPS in HDPCs. CONCLUSION: P. gingivalis contributes to pulpal inflammation in HDPCs by dysregulating PI3K/Akt signaling pathway to stimulate IL-6 and IL-8 mRNA/protein expression and secretion. These results are useful for understanding the pulpal inflammation and possible biomarkers of inflamed pulp diagnosis and treatment.
Asunto(s)
Pulpa Dental , Interleucina-6 , Interleucina-8 , Lipopolisacáridos , Porphyromonas gingivalis , Proteínas Proto-Oncogénicas c-akt , Pulpitis , Humanos , Pulpa Dental/inmunología , Pulpa Dental/microbiología , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucina-8/genética , Interleucina-8/metabolismo , Osteonectina/metabolismo , Fosfatidilinositol 3-Quinasa/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Porphyromonas gingivalis/inmunología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Pulpitis/inmunología , Pulpitis/microbiologíaRESUMEN
AIM: To investigate the effects of butyric acid (BA), a metabolic product generated by pulp and root canal pathogens, on the viability and intercellular adhesion molecule-1 (ICAM-1) production of endothelial cells, which are crucial to angiogenesis and pulpal/periapical wound healing. METHODOLOGY: Endothelial cells were exposed to butyrate with/without inhibitors. Cell viability, apoptosis and reactive oxygen species (ROS) were evaluated using an MTT assay, PI/annexin V and DCF fluorescence flow cytometry respectively. RNA and protein expression was determined using a polymerase chain reaction assay and Western blotting or immunofluorescent staining. Soluble ICAM-1 (sICAM-1) was measured using an enzyme-linked immunosorbent assay. The quantitative results were expressed as mean ± standard error (SE) of the mean. The data were analysed using a paired Student's t-test where necessary. A p-value ≤0.05 was considered to indicate a statistically significant difference between groups. RESULTS: Butyrate (>4 mM) inhibited cell viability and induced cellular apoptosis and necrosis. It inhibited cyclin B1 but stimulated p21 and p27 expression. Butyrate stimulated ROS production and hemeoxygenase-1 (HO-1) expression as well as activated the Ac-H3, p-ATM, p-ATR, p-Chk1, p-Chk2, p-p38 and p-Akt expression of endothelial cells. Butyrate stimulated ICAM-1 mRNA/protein expression and significant sICAM-1 production (p < .05). Superoxide dismutase, 5z-7oxozeaenol, SB203580 and compound C (p < .05), but not ZnPP, CGK733, AZD7762 or LY294002, attenuated butyrate cytotoxicity to endothelial cells. Notably, little effect on butyrate-stimulated sICAM-1 secretion was found. Valproic acid, phenylbutyrate and trichostatin (three histone deacetylase inhibitors) significantly induced sICAM-1 production (p < .05). CONCLUSION: Butyric acid inhibited proliferation, induced apoptosis, stimulated ROS and HO-1 production and increased ICAM-1 mRNA expression and protein synthesis in endothelial cells. Cell viability affected by BA was diminished by some inhibitors; however, the increased sICAM-1 secretion by BA was not affected by any of the tested inhibitors. These results facilitate understanding of the pathogenesis, prevention and treatment of pulpal/periapical diseases.
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Ácido Butírico/farmacología , Células Endoteliales/metabolismo , Molécula 1 de Adhesión Intercelular , Enfermedades Periapicales , Células Cultivadas , Pulpa Dental/citología , Humanos , Molécula 1 de Adhesión Intercelular/metabolismoRESUMEN
Horizontal root fractures (HRF) were observed mostly in the anterior teeth of young adults due to dental injury. However, HRFs in posterior teeth (PHRF) without dental trauma cannot be neglected. The etiology and risk factors of PHRF were unclear. Lower premolars and palatal root of maxillary molars were particularly affected, indicating the specificity of this diseased entity. PHRF were mainly reported in Asian population, suggesting possible racial difference. Whereas most PHRF teeth showed symptoms mimicking endodontic and periodontal lesions, some affected teeth were asymptomatic. Periodontal pocket, soft tissue swelling, chronic pain or discomfort during mastication were commonly noted. Diagnosis of PHRF depended on thorough clinical examination, radiographic images or exploratory surgery. Intracanal bleeding and electronic apex locator confirmation during endodontic treatment were also useful for diagnosis. Flexible splinting, endodontic/periodontal treatment or root amputation were treatment strategies to preserve the fractured teeth. The aim of this narrative review is to summarize the demography, tooth and root distribution, diagnostic methods, etiology and possible related factors, clinical features, radiographic characteristics, and the treatment schemes of PHRF without dental trauma. A better understanding and identification of this particular root fracture could be achieved. The diagnostic tools and practical management are useful for clinical guides.
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Fracturas de los Dientes , Raíz del Diente , Diente Premolar , Humanos , Diente Molar , Bolsa Periodontal , Tratamiento del Conducto Radicular , Adulto JovenRESUMEN
BACKGROUND/PURPOSE: The unpredictable condition of cracked teeth warrants further investigation and clinical experiences. The purpose of this study was to collect and record data on demographics, clinical characteristics, different treatment modalities and survival of cracked teeth at 6-month, 1-year and 2-year recalls. METHODS: 77 cracked teeth from 65 patients were included. Data on demographics, clinical parameters, treatment modalities and recall were collected. Binomial, multinomial and chi square tests were used for statistical analysis. RESULTS: Most cracked teeth occurred in patients greater than 40 years old (p < 0.01). Cracked teeth themselves were most often molars (79.22%; p < 0.01), a non-terminal tooth in the arch (62.34%; p < 0.05) and nonendodontically-treated teeth (94.81%; p < 0.01). Cracked teeth exhibited pain to percussion (63.64%, p < 0.05) or biting (74.03%; p < 0.01), and no or only positive mobility (76.62%; p < 0.01). Cracks were most often oriented in the mesiodistal direction (68.83%; p < 0.01). Higher survival rates were noted in cracked teeth lacking pre-operative pain to palpation or spontaneous pain, and with no or only positive mobility at 6-month and 1-year recalls. In vital cracked teeth, higher survival rates were noted in teeth lacking pre-operative pain to palpation and with no or only positive mobility at 2-year recalls. CONCLUSION: The absence of pre-operative palpation discomfort, spontaneous pain and minimal mobility, as well as the presence of pulp vitality were associated with higher survival rates of cracked teeth at all recall times. Results are useful for diagnosis and outcomes-based treatment planning of cracked teeth.
Asunto(s)
Síndrome de Diente Fisurado , Traumatismos de los Dientes , Adulto , Restauración Dental Permanente , Análisis del Estrés Dental , HumanosRESUMEN
BACKGROUND/PURPOSE: Understanding the root canal systems of molars and the association of root canal system in adjacent or contralateral molars is important for dental practice. This study aimed to use cone-beam computed tomography (CBCT) to analyze the morphology similarity of root canal systems in the maxillary first and second molars. METHODS: CBCT images of 1741 maxillary molars in a total of 519 patients were blindly examined to analyze the correlation of root canal systems between maxillary first and second molars as well as the bilateral first and second molars. RESULTS: The most common type in maxillary first molars is 3R4C (3 roots/4 canals), whereas in maxillary second molars is 3R3C.The symmetry in type of root canals in bilateral maxillary first and second molars were 87.36% and 79.85%, respectively. The similarities of root canal system in adjacent maxillary first and second molars were 53.07% (right side) and 52.58% (left side). The concurrence of MB2 canal in bilateral maxillary first molars is 77.8%, and 35.97% in maxillary second molars. In the 110 patients with MB2 canal in bilateral maxillary second molars, the chance of bilateral MB2 canals in their maxillary first molar is almost 100%. CONCLUSION: Maxillary first molars have higher prevalence of 3R4C than second molars. The symmetry in bilateral maxillary molars is higher than the similarity in adjacent maxillary first and second molars. Application of CBCT analysis of root canal system can improve endodontic treatment outcomes. The correlation of root canal system between teeth is useful for genetic linkage.
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Tomografía Computarizada de Haz Cónico , Cavidad Pulpar , Maxilar , Raíz del Diente , Cavidad Pulpar/diagnóstico por imagen , Humanos , Maxilar/diagnóstico por imagen , Diente Molar/diagnóstico por imagen , Raíz del Diente/diagnóstico por imagenRESUMEN
BACKGROUND/PURPOSE: Basic fibroblast growth factor (bFGF) exhibits multiple biological functions in various tissues. Stem cells from apical papilla (SCAP) can be isolated from human apical papilla tissues in developmental teeth of children. The purposes of this study were to investigate the expression of FGF receptors (FGFRs) and the effects of bFGF on SCAP and related MEK/ERK signaling. METHODS: SCAP cells were treated under different concentrations of bFGF with or without U0126 (an inhibitor of MEK/ERK). Expression of FGFR1 and FGFR2 in SCAP was analyzed by RT-PCR. Cell proliferation was measured by MTT assay. The expressions of type I collagen, cdc 2, cyclin B1, TIMP-1 and p-ERK proteins were examined by Western blot. RESULTS: SCAP cells expressed FGFR1 and FGFR2. Exposure of SCAP to bFGF enhanced cell proliferation, and the expression cyclinB1, cdc 2, and TIMP-1, but not type I collagen. U0126 pretreatment and co-incubation attenuated the bFGF-induced proliferation, cdc2, cyclin B1 and TIMP-1 proteins' expression, but not type I collagen in SCAP. CONCLUSION: SCAP cells express FGFRs. bFGF may stimulate proliferation and affect the matrix turnover of SCAP cells, possibly via stimulation of FGFRs and MEK/ERK signaling pathway. These results are useful for clinical therapies for apexogenesis and regeneration of pulpo-dentin complex.
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Células Madre , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Quinasas MAP Reguladas por Señal Extracelular , Factor 2 de Crecimiento de Fibroblastos , Humanos , Sistema de Señalización de MAP Quinasas , Quinasas de Proteína Quinasa Activadas por MitógenosRESUMEN
Betel quid (BQ) chewing increased the risk of oral cancer and oral submucous fibrosis (OSMF), an oral premalignant disorder (OPMD) with malignant transformation potential. BQ components such as areca nut (AN), trauma by coarse AN fiber, catechin, copper, alkaloids, stimulated reactive oxygen species (ROS), inflammation and cytotoxicity are suggested to be the contributing factors. They may induce tissue inflammation, proliferation of fibroblasts and collagen deposition, myofibroblast differentiation and contraction, collagen cross-links and inhibit collagen phagocytosis, finally leading to the development of OSMF and oral cancer. These events are mediated by BQ components-induced changes of extracellular matrix (ECM) turnover via regulation of TGF-ß1, plasminogen activator inhibitor-1 (PAI-1), cystatin, lysyl oxidase (LOX) and tissue inhibitors of metalloproteinases (TIMPs) and metalloproteinases (MMPs). Genetic susceptibility is also involved in these disease processes. Further understanding the molecular mechanisms of BQ-induced OSMF and oral cancer can be helpful for future disease prevention and treatment.
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Areca/efectos adversos , Proteínas de la Matriz Extracelular/metabolismo , Matriz Extracelular/metabolismo , Predisposición Genética a la Enfermedad , Fibrosis de la Submucosa Bucal/patología , Humanos , Fibrosis de la Submucosa Bucal/etiología , Fibrosis de la Submucosa Bucal/metabolismoRESUMEN
Platelets play crucial roles in thrombosis and hemostasis through platelet activation and aggregation that are crucial in cardiovascular diseases. Hydroquinone (HQ) and its derivatives are present in many dermatological creams, paints, motor fuels, air, microorganisms, and plant products like wheat bread, fruit, coffee, and red wine. The effect of HQ on humans is not clear. In this study, we found that HQ (>25 µM) inhibited arachidonic acid (AA)-induced platelet aggregation. HQ suppressed AA-induced thromboxane B2 production of platelets. HQ (>10 µM) also attenuated ex vivo platelet-rich plasma aggregation. HQ prevented the interleukin (IL)-1ß-induced 8-isoprostane, and PGE2 production, but not IL-8 production of pulp cells. These results indicate that HQ may have an antiplatelet effect via inhibition of thromboxane production. HQ has antioxidative and anti-inflammatory effects, and possible inhibition of COX. Exposure and consumption of HQ-containing products, food or drugs may have antiplatelet, antioxidative, and anti-inflammatory effects.
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Antiinflamatorios/farmacología , Antioxidantes/farmacología , Plaquetas/efectos de los fármacos , Pulpa Dental/efectos de los fármacos , Hidroquinonas/farmacología , Inhibidores de Agregación Plaquetaria/farmacología , Agregación Plaquetaria/efectos de los fármacos , Animales , Plaquetas/metabolismo , Células Cultivadas , Ciclooxigenasa 2/metabolismo , Pulpa Dental/citología , Pulpa Dental/metabolismo , Dinoprost/análogos & derivados , Dinoprost/metabolismo , Dinoprostona/metabolismo , Humanos , Mediadores de Inflamación/metabolismo , Interleucina-8/metabolismo , Ratones , Conejos , Transducción de Señal , Tromboxano A2/metabolismoRESUMEN
BACKGROUND/PURPOSE: Interleukin 1 beta (IL-1ß) is a pro-inflammatory cytokine involved in the acute and chronic inflammatory processes of dental pulp. Intercellular adhesion molecule-1 (ICAM-1) and IL-8 are two major inflammatory mediators. However, the role of interleukin-1 receptor-associated kinases (IRAKs) signaling pathways in responsible for the inflammatory effects of IL-1ß on dental pulp cells is not clear. METHODS: Cultured human dental pulp cells were exposed to IL-1ß with/without pretreatment and co-incubation with IRAK1/4 inhibitor or SB203580 (p38 inhibitor). IRAK-1 phosphorylation was evaluated by immunno fluorescent staining. The protein expression of ICAM-1 and IL-8 were tested by western blotting. The secretion of soluble ICAM-1 (sICAM-1) and IL-8 was measured by enzyme-linked immunosorbant assay (ELISA). RESULTS: IL-1ß stimulated IRAK-1 phosphorylation of pulp cells within 120 min of exposure. IRAK1/4 inhibitor attenuated the IL-1ß-induced ICAM-1, but not IL-8 protein expression. IRAK1/4 inhibitor also prevented the IL-1ß-induced sICAM-1, but not IL-8 secretion. SB203580 showed little effect on IL-1ß-induced sICAM-1 secretion, but effectively inhibited its induction of IL-8 secretion in pulp cells. CONCLUSION: The Results reveal the important role of IL-1ß in pulpal inflammatory responses via stimulation of IL-8 and ICAM-1 expression and secretion. Moreover, IL-1ß-induced effects on IL-8 and ICAM-1 are differentially regulated by IRAK1/4 and p38 signaling in dental pulp cells. Blocking of IRAKs and p38 signaling may have potential to control inflammation of dental pulp in the future.
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Pulpa Dental/citología , Molécula 1 de Adhesión Intercelular/metabolismo , Quinasas Asociadas a Receptores de Interleucina-1/antagonistas & inhibidores , Interleucina-1beta/farmacología , Interleucina-8/metabolismo , Western Blotting , Células Cultivadas , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Humanos , Transducción de Señal/efectos de los fármacos , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidoresRESUMEN
BACKGROUND/PURPOSE: Apical surgery is an option for management of endodontically-treated tooth with persistent periapical lesions or symptom and sign. The objective of this study was to investigate the correlation between the demography, preoperative, postoperative factors and healed rate of apical surgery. METHODS: Subjects were retrospectively collected from patients who received apical surgery/apicoectomy at the Endodontic Department, National Taiwan University Hospital from January 2013 to June 2015. The standard apical surgery procedures were performed. The demography, preoperative clinical and radiographic examination data as well as postoperative variables were collected. The outcome assessment was carried out after surgery. Statistical analysis was performed by chi square test to evaluate the potential outcome predictors. RESULTS: Total 187 patients and 234 teeth receiving apical surgery were included. 53 male and 134 female patients were collected. The age was ranged between 17 and 89 years old and the mean age was 43.64 years old. Better healed rate with significant differences were observed in female patient (p < 0.05), age ≤60 years old (p < 0.01), preoperative root canal filling material >2 mm short of apex (p < 0.01), lesion size from ≤2 mm to ≤12 mm (p < 0.05) and follow-up period â§12 months (p < 0.01) groups. CONCLUSION: Gender, age, preoperative root canal filling material extent, lesion size and follow-up period may affect the outcome of apical surgery. Tooth type, post, prosthesis, and lesion area showed no marked effect on apical healing. These results provide more detailed information for the clinical practitioners to make treatment plans and are important for clinical endodontic practices.
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Apicectomía/estadística & datos numéricos , Materiales de Obturación del Conducto Radicular/uso terapéutico , Ápice del Diente/cirugía , Diente no Vital/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiografía Dental , Estudios Retrospectivos , Taiwán , Ápice del Diente/diagnóstico por imagen , Resultado del Tratamiento , Adulto JovenRESUMEN
Cemental tear is a special kind of root surface fracture, contributing to periodontal and periapical breakdown. However, it is a challenge for doctors to diagnose, resulting in delayed or improper treatment. We reviewed the predisposing factors, location, radiographic/clinical characteristics, diagnosis and treatments of cemental tears. From the literature, patients with cemental tear were mainly males, over 60 year-old. Possible predisposing factors include gender, age, tooth type, traumatic occlusal force and vital teeth. Cemental tears were common in upper and lower anterior teeth, single or multiple, and can be present in cervical, middle and apical third of roots. Morphology of cemental tears can be either piece-shaped or U-shaped. Clinically, cemental tear shows a unitary periodontal pocket and signs/symptoms mimicking localized periodontitis, apical periodontitis and vertical root fractures. Treatment of cemental tears include scaling, root planning, root canal treatment, periodontal/periapical surgery, guided tissue regeneration, bone grafting, and intentional replantation. Recurrence of cemental tear is possible especially when the fracture involves root apex. Extraction is recommended for teeth with poor prognosis. In conclusion, cemental tears can involve both periodontal and periapical area. Dentists should understand the predisposing factors and clinical features of cemental tears for early diagnosis/treatment to prevent bone loss/tooth extraction.
Asunto(s)
Cemento Dental/lesiones , Anciano , Anciano de 80 o más Años , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tratamiento del Conducto Radicular/efectos adversos , Fracturas de los Dientes/etiología , Raíz del Diente/lesionesRESUMEN
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.
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Pulpa Dental/citología , Células Epiteliales/efectos de los fármacos , Interleucina-1beta/farmacología , Interleucina-8/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Fragmentos de Péptidos/metabolismo , Activador de Plasminógeno de Tipo Uroquinasa/metabolismo , Butadienos/farmacología , Células Cultivadas , Inhibidores Enzimáticos/farmacología , Humanos , Quinasas Quinasa Quinasa PAM/metabolismo , Nitrilos/farmacología , Zearalenona/análogos & derivados , Zearalenona/farmacologíaRESUMEN
Butyric acid as a histone deacetylase (HDAC) inhibitor is produced by a number of periodontal and root canal microorganisms (such as Porphyromonas, Fusobacterium, etc.). Butyric acid may affect the biological activities of periodontal/periapical cells such as osteoblasts, periodontal ligament cells, etc., and thus affect periodontal/periapical tissue destruction and healing. The purposes of this study were to study the toxic effects of butyrate on the matrix and mineralization marker expression in MG-63 osteoblasts. Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cellular apoptosis and necrosis were analyzed by propidium iodide/annexin V flow cytometry. The protein and mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) were analyzed by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). OPG, soluble RANKL (sRANKL), 8-isoprostane, pro-collagen I, matrix metalloproteinase-2 (MMP-2), osteonectin (SPARC), osteocalcin and osteopontin (OPN) secretion into culture medium were measured by enzyme-linked immunosorbant assay. Alkaline phosphatase (ALP) activity was checked by ALP staining. Histone H3 acetylation levels were evaluated by immunofluorescent staining (IF) and Western blot. We found that butyrate activated the histone H3 acetylation of MG-63 cells. Exposure of MG-63 cells to butyrate partly decreased cell viability with no marked increase in apoptosis and necrosis. Twenty-four hours of exposure to butyrate stimulated RANKL protein expression, whereas it inhibited OPG protein expression. Butyrate also inhibited the secretion of OPG in MG-63 cells, whereas the sRANKL level was below the detection limit. However, 3 days of exposure to butyrate (1 to 8 mM) or other HDAC inhibitors such as phenylbutyrate, valproic acid and trichostatin stimulated OPG secretion. Butyrate stimulated 8-isoprostane, MMP-2 and OPN secretion, but not procollagen I, or osteocalcin in MG-63 cells. Exposure to butyrate (2â»4 mM) for 3 days markedly stimulated osteonectin secretion and ALP activity. In conclusion, higher concentrations of butyric acid generated by periodontal and root canal microorganisms may potentially induce bone destruction and impair bone repair by the alteration of OPG/RANKL expression/secretion, 8-isoprostane, MMP-2 and OPN secretion, and affect cell viability. However, lower concentrations of butyrate (1â»4 mM) may stimulate ALP, osteonectin and OPG. These effects are possibly related to increased histone acetylation. These events are important in the pathogenesis and repair of periodontal and periapical destruction.
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Butiratos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Histonas/metabolismo , Isoprostanos/biosíntesis , Osteoblastos/metabolismo , Osteoprotegerina/biosíntesis , Ligando RANK/biosíntesis , Acetilación/efectos de los fármacos , Butiratos/metabolismo , Línea Celular , Cavidad Pulpar/metabolismo , Cavidad Pulpar/microbiología , Cavidad Pulpar/patología , Histonas/genética , Humanos , Isoprostanos/genética , Osteoblastos/patología , Osteoprotegerina/genética , Periodontitis/genética , Periodontitis/metabolismo , Periodontitis/microbiología , Periodontitis/patología , Ligando RANK/genéticaRESUMEN
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.
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Ciclooxigenasa 2/metabolismo , Dinoprostona/metabolismo , Células Epiteliales/citología , Transducción de Señal/efectos de los fármacos , Factor de Crecimiento Transformador beta1/farmacología , Benzamidas/farmacología , Butadienos/farmacología , Diferenciación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Ciclooxigenasa 2/genética , Pulpa Dental/citología , Pulpa Dental/efectos de los fármacos , Dioxoles/farmacología , Células Epiteliales/efectos de los fármacos , Humanos , Nitrilos/farmacología , Proteínas Serina-Treonina Quinasas/metabolismo , Receptor Tipo I de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Proteína Smad2/metabolismoRESUMEN
BACKGROUND/PURPOSE: In order to clarify the role of transforming growth factor beta 1 (TGF-ß1) in pulp repair/regeneration responses, we investigated the differential signaling pathways responsible for the effects of TGF-ß1 on collagen turnover, matrix metalloproteinase-3 (MMP-3), and tissue inhibitor of metalloproteinase-1 (TIMP-1) production in human dental pulp cells. METHODS: Pulp cells were exposed to TGF-ß1 with/without pretreatment and coincubation by 1,4-diamino-2,3-dicyano-1,4-bis(o-aminophenyl mercapto)butadiene (U0126; a mitogen-activated protein kinase kinase [MEK]/extracellular signal-regulated kinase [ERK] inhibitor) and 4-(5-benzol[1,3]dioxol-5-yl-4-pyrldin-2-yl-1H- imidazol-2-yl)-benzamide hydrate (SB431542; an activin receptor-like kinase-5/Smad signaling inhibitor). Sircol collagen assay was used to measure cellular collagen content. Culture medium procollagen I, TIMP-1, and MMP-3 levels were determined by enzyme-linked immunosorbent assay. RESULTS: TGF-ß1 increased the collagen content, procollagen I, and TIMP-1 production, but slightly decreased MMP-3 production of pulp cells. SB431542 and U0126 prevented the TGF-ß1-induced increase of collagen content and TIMP-1 production of dental pulp cells. CONCLUSION: These results indicate that TGF-ß1 may be involved in the healing/regeneration processes of dental pulp in response to injury by stimulation of collagen and TIMP-1 production. These events are associated with activin receptor-like kinase-5/Smad2/3 and MEK/ERK signaling.
Asunto(s)
Colágeno Tipo I/metabolismo , Colágeno/fisiología , Regeneración/fisiología , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Factor de Crecimiento Transformador beta1/fisiología , Benzamidas/farmacología , Butadienos/farmacología , Células Cultivadas , Pulpa Dental/citología , Dioxoles/farmacología , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/fisiología , Nitrilos/farmacología , Proteínas Serina-Treonina Quinasas/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/fisiología , Receptor Tipo I de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/efectos de los fármacos , Receptores de Factores de Crecimiento Transformadores beta/fisiología , Regeneración/efectos de los fármacos , Proteínas Smad/efectos de los fármacos , Proteínas Smad/fisiologíaRESUMEN
BACKGROUND/PURPOSE: Betel quid (BQ) chewing is popular in Taiwan and many other countries. There are about 200-600 million BQ chewers in the world. BQ chewing is one major risk factor of oral cancer and oral submucous fibrosis (OSF). While areca nut (AN), a main component of BQ, exhibits genotoxicity, its transformation capacity and its role in the initiation and promotion stages of carcinogenesis are not fully clear. METHODS: Mouse C3H10T1/2 cells were exposed to AN extract (ANE) for 24 hours. Cytotoxicity was evaluated by colony forming efficiency. For the transformation assay, C3H10T1/2 cells were exposed to ANE for 24 hours and then incubated in medium with/without 12-O-tetradecanolylphorbol-13-acetate (TPA; a tumor promoter) for 42 days. Cells were stained with Giemsa and type II and type III transformed foci were counted for analysis of the transformation capacity of ANE. RESULTS: ANE exhibited cytotoxicity to C3H10T/12 cells at concentrations higher than 320 µg/mL as shown by a decrease in colony numbers. ANE (80-640 µg/mL) alone mildly stimulated the transformed foci formation (p > 0.05). In the presence of TPA, ANE (80-640 µg/mL) markedly stimulated the transformed foci formation. The percentage of dishes with foci increased from 0% in controls to 20% in ANE (80 µg/mL and 320 µg/mL)-treated groups and further increased to 65-94% in ANE plus TPA groups. CONCLUSION: These results indicate that ANE is a weak complete carcinogen. ANE is an effective tumor initiator and can induce malignant transformation of C3H10T1/2 cells in the presence of a tumor promoter. ANE may be involved in multistep chemical carcinogenesis by its malignant transformation capacity.
Asunto(s)
Areca/química , Nueces/química , Extractos Vegetales/toxicidad , Células Madre Pluripotentes/efectos de los fármacos , Animales , Línea Celular , Ratones , Neoplasias de la Boca/inducido químicamente , Especies Reactivas de Oxígeno/metabolismo , TaiwánRESUMEN
BACKGROUND/PURPOSE: In Taiwan, the combination of betel quid chewing, alcohol consumption, and smoking habits increases oral cancer risk by 123-fold compared to persons without these habits. Lymphocyte populations in patients may potentially affect the malignant transformation of oral precancer. METHODS: A total of 28 patients with oral precancer from our previous cohort were enrolled in this study, and their personal information and oral habits were documented. Their lymphocyte populations (CD4+, CD8+, CD19+, and CD56+) and activation markers (CD25 and CD69) were determined by flow cytometry from 1999 to 2004. After follow up till December 2014, data of patients with/without malignant transformation were recorded, and the relation between oral habits and percentage of initial lymphocyte markers was evaluated using the Student t test and Fisher's exact test. RESULTS: Ten precancer patients developed oral squamous cell carcinoma with a mean period of malignant transformation of 6.8 ± 2.1 years. Patients with malignant transformation had a mean age of 48.4 ± 5.0 years (n = 10), relatively more than that of patients without malignant transformation (41.6 ± 6.3 years, n = 18) (p < 0.05). An increase was noted in the population of peripheral blood mononuclear cells expressing CD4+CD69+, CD19+CD69+, and CD56+CD69+ (p < 0.05) in precancer patients with malignant transformation. Alcohol consumption showed an association with the malignant transformation of patients with precancer (p = 0.030), whereas betel quid and smoking showed little effect. CONCLUSION: These results suggest that age, alcohol consumption, and early activation of T cells, B cells, and natural killer cells are crucial in the malignant transformation of oral precancer. Analysis of patient's lymphocyte populations may help predict the malignant transformation of oral precancer.
Asunto(s)
Consumo de Bebidas Alcohólicas/epidemiología , Areca/efectos adversos , Carcinoma de Células Escamosas/epidemiología , Subgrupos Linfocitarios/inmunología , Neoplasias de la Boca/epidemiología , Fumar/epidemiología , Adulto , Linfocitos B/inmunología , Biomarcadores/análisis , Humanos , Células Asesinas Naturales/inmunología , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/etiología , Taiwán/epidemiologíaRESUMEN
OBJECTIVE: Interleukin-1ß (IL-1ß) is an important inflammatory mediator of the dental pulp. IL-1ß stimulates cyclooxygenase-2 (COX-2) expression and prostanoid production of pulp cells and affects the inflammatory and healing processes of the dental pulp. There are two interleukin-1 (IL-1) receptors, IL-1RI and IL-1RII, with opposing effect after activation. However, the expression of IL-1Rs, the effects of IL-1ß on intercellular adhesion molecule-1 (ICAM-1) of dental pulp cells, and its relation to protein kinase B (Akt) signaling and COX activation are not clear. METHOD: Human dental pulp cells were treated with IL-1ß with/without pretreatment and co-incubation by LY294002 (a PI3K/Akt inhibitor), U0126 [a mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) inhibitor], aspirin (a COX inhibitor), or eugenol (a COX inhibitor) for different time periods. The expression of ICAM-1, IL-1RI, and IL-1RII messenger RNA (mRNA) was evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR). ICAM-1 protein expression was examined by western blotting. Soluble ICAM-1 (sICAM-1) level in the culture medium was determined by enzyme-linked immunosorbent assay (ELISA). Activation of Akt and ERK by IL-1ß was measured by Pathscan p-Akt ELISA or western blot. Viable cell number was evaluated by 3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: Dental pulp cells expressed IL-1RI, but little IL-1RII. IL-1ß stimulated COX-2 and ICAM-1 mRNA and protein expression as well as sICAM-1 production of pulp cells. Aspirin and eugenol enhanced the IL-1ß-induced sICAM-1 production and ICAM-1 expression. IL-1ß rapidly activated Akt and ERK. LY294002 and U0126 attenuated IL-1ß-induced ICAM-1 expression and sICAM-1 production. CONCLUSIONS: These results reveal that IL-1ß may be involved in the pulpal inflammatory processes by stimulating ICAM-1 expression and secretion. These events are associated with IL-1RI expression and differential activation of PI3K/Akt and MEK/ERK and COX. CLINICAL RELEVANCE: Pharmacological inhibition of IL-1ß, IL-1RI, COX-2, ICAM-1, and related signaling pathways (MEK/ERK and PI3K/Akt) may be useful for the control of pulpal inflammation.
Asunto(s)
Ciclooxigenasa 2/metabolismo , Pulpa Dental/citología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Molécula 1 de Adhesión Intercelular/metabolismo , Interleucina-1beta/farmacología , Fosfatidilinositol 3-Quinasas/metabolismo , Aspirina/farmacología , Western Blotting , Cromonas/farmacología , Ensayo de Inmunoadsorción Enzimática , Eugenol/farmacología , Humanos , Morfolinas/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/efectos de los fármacosRESUMEN
BACKGROUND/PURPOSE: Mechanical loading plays an important role in regulating bone formation and remodeling. Relevant mechanical stretching can increase the proliferation and differentiation of osteoblastic cells in vitro. However, little is known about the effects of supraphysiological high-level mechanical stretching on the growth and cell cycle progression of osteoblastic cells. METHODS: Osteoblast-like MG-63 cells were seeded onto flexible-bottomed plates and subjected to cyclic mechanical stretching (15% elongation, 0.5 Hz) for 24 and 48 hours in a Flexercell FX-4000 strain unit. Cellular activities were measured by an assay based on the reduction of the tetrazolium salt, 3-[4,5-dimethyldiazol-2-yl]-2,5-diphenyl tetra-zolium bromide (MTT). The number of viable cells was also determined by the trypan blue dye exclusion technique. Cell cycle progression was checked by flow cytometry. mRNA expressions of apoptosis- and cell cycle-related genes (Bcl2, Bax, cdc2, cdc25C, and cyclin B1) were analyzed using an RT-PCR technique. RESULTS: The number of viable cells significantly decreased in osteoblast-like MG-63 cells subjected to cyclic mechanical stretching for 24 or 48 hours. The MTT activity of stretched cells did not change at 24 hours, whereas a significant decrease was noted at 48 hours in comparison to the unstretched controls. The flow cytometry showed that mechanical stretching induced S-phase cell cycle arrest. Furthermore, exposure to mechanical stretching led to apoptotic cell death, as shown by the increase in the hypodiploid sub-G0/G1 cell population. Furthermore, a decreased cdc25C mRNA level was consistently noted in stretched cells. However, the mRNA expressions of Bcl2, Bax, cdc2, and cyclin B1 genes were not significantly altered compared to the unstretched control cells. CONCLUSION: High-level mechanical stretching induced S-phase cell cycle arrest and apoptotic cell death in osteoblastic cells. The results suggest that heavy tensional force is a negative regulator of osteoblastic activities and should, therefore, be minimized if bone formation is attempted during orthodontic/orthopedic treatment.
Asunto(s)
Osteoblastos/fisiología , Estrés Fisiológico/fisiología , Apoptosis , Fenómenos Biomecánicos , Proteína Quinasa CDC2 , Proliferación Celular , Supervivencia Celular , Células Cultivadas , Ciclina B1/genética , Quinasas Ciclina-Dependientes/genética , Expresión Génica , Humanos , Proteínas Proto-Oncogénicas c-bcl-2/genética , Puntos de Control de la Fase S del Ciclo Celular , Fosfatasas cdc25/genéticaRESUMEN
This longevity of life expectancy has indirectly led to an increase in the number of chronic diseases such as periodontitis, apical periodontitis (AP), and diabetes mellitus (DM) in the aging society, thus affecting people's quality of life. There is an interaction between periodontitis/AP and DM with a two-way relationship. Although type 1 and 2 diabetes (T1DM, T2DM) have different etiologies, glycemic control may affect the infection, inflammation and tissue healing of periodontitis and AP. Non-surgical periodontal treatment may influence the glycemic control as shown by decrease of HbA1c level in T2DM patient. However, the effect of periodontal treatment on glycemic control in T1DM and root canal treatment/apical surgery on T1DM and T2DM patients awaits investigation. DM may affect the periodontal and periapical tissues possibly via altered oral microbiota, impairment of neutrophils' activity and host immune responses and cytokine production, induction of oxidative stress etc. While periodontitis associated systemic inflammation and hyperlipidemia is suggested to contribute to the control of T2DM, more intricate studies are necessary to clarify the detailed mechanisms. The interactions between DM (T1DM and T2DM) and periodontitis and AP are therefore reviewed to provide a basis for the treatment of subsequent patients with pulpal/periodontal disease and diabetes. A two-pronged approach of medical and dental treatment is needed for the management of these patients, with emphasis on blood glucose control and improving oral hygiene and periodontal maintenance care, to ensure the best treatment outcome.