RESUMEN
Porphyromonas gingivalis is commonly known as one of the major pathogens contributing to periodontitis, and its persistent infection may increase the risk for the disease. The proinflammatory mediators, including IL-6, TNF-α, and cyclooxygenase-2 (COX-2)/PGE2, are closely associated with progression of periodontitis. In this study, we focused on the cysteine protease "gingipains," lysine-specific gingipain, arginine-specific gingipain (Rgp) A, and RgpB, produced by P. gingivalis, and used the wild-type strain and several gene-deletion mutants (rgpA, rgpB, kgp, and fimA) to elucidate the involvement of gingipains in COX-2 expression and PGE2 production. We infected human monocytes, which are THP-1 cells and primary monocytes, with these bacterial strains and found that gingipains were involved in induction of COX-2 expression and PGE2 production. We have shown that the protease activity of gingipains was crucial for these events by using gingipain inhibitors. Furthermore, activation of ERK1/2 and IκB kinase was required for gingipain-induced COX-2 expression/PGE2 production, and these kinases activated two transcription factors, c-Jun/c-Fos (AP-1) and NF-κB p65, respectively. In particular, these data suggest that gingipain-induced c-Fos expression via ERK is essential for AP-1 formation with c-Jun, and activation of AP-1 and NF-κB p65 plays a central role in COX-2 expression/PGE2 production. Thus, we show the (to our knowledge) novel finding that gingipains with the protease activity from P. gingivalis induce COX-2 expression and PGE2 production via activation of MEK/ERK/AP-1 and IκB kinase/NF-κB p65 in human monocytes. Hence it is likely that gingipains closely contribute to the inflammation of periodontal tissues.
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Ciclooxigenasa 2/biosíntesis , Dinoprostona/biosíntesis , Cisteína-Endopeptidasas Gingipaínas/metabolismo , Sistema de Señalización de MAP Quinasas/fisiología , Periodontitis/patología , Porphyromonas gingivalis/metabolismo , Proteínas Bacterianas/genética , Línea Celular , Cisteína Endopeptidasas/genética , Proteínas Fimbrias/genética , Cisteína-Endopeptidasas Gingipaínas/genética , Humanos , Quinasa I-kappa B/metabolismo , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Monocitos/microbiología , Periodontitis/microbiología , Células THP-1 , Factor de Transcripción AP-1/metabolismo , Factor de Transcripción ReIA/metabolismoRESUMEN
The major active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D3), is known for its wide bioactivity in periodontal tissues. Although the exact mechanisms underlying its protective action against periodontitis remain unclear, recent studies have shown that 1,25D3 regulates autophagy. Autophagy is vital for intracellular pathogen invasion control, inflammation regulation, and bone metabolic balance in periodontal tissue homeostasis, and its regulation could be an interesting pathway for future periodontal studies. Since vitamin D deficiency is a worldwide health problem, its role as a potential regulator of autophagy provides new insights into periodontal diseases. Based on this premise, this narrative literature review aimed to investigate the possible connection between 1,25D3 and autophagy in periodontitis. A comprehensive literature search was conducted on PubMed using the following keywords (e.g., vitamin D, autophagy, periodontitis, pathogens, epithelial cells, immunity, inflammation, and bone loss). In this review, the latest studies on the protective action of 1,25D3 against periodontitis and the regulation of autophagy by 1,25D3 are summarized, and the potential role of 1,25D3-activated autophagy in the pathogenesis of periodontitis is analyzed. 1,25D3 can exert a protective effect against periodontitis through different signaling pathways in the pathogenesis of periodontitis, and at least part of this regulatory effect is achieved through the activation of the autophagic response. This review will help clarify the relationship between 1,25D3 and autophagy in the homeostasis of periodontal tissues and provide perspectives for researchers to optimize prevention and treatment strategies in the future.
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Calcitriol , Periodontitis , Humanos , Vitamina D , Autofagia , InflamaciónRESUMEN
BACKGROUND: Plasminogen serves as the precursor to plasmin, an essential element in the fibrinolytic process, and is synthesized primarily in the liver. Plasminogen activation occurs through the action of plasminogen activator, converting it into plasmin. This conversion greatly enhances the fibrinolytic system within tissues and blood vessels, facilitating the dissolution of fibrin clots. Consequently, congenital deficiency of plasminogen results in impaired fibrin degradation. Patients with plasminogen deficiency typically exhibit fibrin deposits in various mucosal sites throughout the body, including the oral cavity, eyes, vagina, and digestive organs. Behcet's disease is a chronic recurrent systemic inflammatory disease with four main symptoms: aphthous ulcers of the oral mucosa, vulvar ulcers, skin symptoms, and eye symptoms, and has been reported worldwide. This disease is highly prevalent around the Silk Road from the Mediterranean to East Asia. We report a case of periodontitis in a patient with these two rare diseases that worsened quickly, leading to alveolar bone destruction. Genetic testing revealed a novel variant characterized by a stop-gain mutation, which may be a previously unidentified etiologic gene associated with decreased plasminogen activity. CASE PRESENTATION: This case report depicts a patient diagnosed with ligneous gingivitis during childhood, originating from plasminogen deficiency and progressing to periodontitis. Genetic testing revealed a suspected association with the PLG c.1468C > T (p.Arg490*) stop-gain mutation. The patient's periodontal condition remained stable with brief intervals of supportive periodontal therapy. However, the emergence of Behçet's disease induced acute systemic inflammation, necessitating hospitalization and treatment with steroids. During hospitalization, the dental approach focused on maintaining oral hygiene and alleviating contact-related pain. The patient's overall health improved with inpatient care and the periodontal tissues deteriorated. CONCLUSIONS: Collaborative efforts between medical and dental professionals are paramount in comprehensively evaluating and treating patients with intricate complications from rare diseases. Furthermore, the PLG c.1468C > T (p.Arg490*) stop-gain mutation could contribute to the association between plasminogen deficiency and related conditions.
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Síndrome de Behçet , Periodontitis , Femenino , Humanos , Fibrinolisina , Síndrome de Behçet/complicaciones , Síndrome de Behçet/genética , Enfermedades Raras/complicaciones , Periodontitis/complicaciones , Periodontitis/genética , Plasminógeno/genética , FibrinaRESUMEN
Dental anterior fractures are common injuries, especially in those who practice extreme sports. This report describes a 25-year-old Bolivian patient who attended our private dental clinic in La Paz, Bolivia after experiencing an accident during downhill mountain biking. An intraoral examination revealed a fracture line on the buccal side in the middle third of the coronal portion of the right central maxillary incisor which extended towards the proximal and lingual sides. Multidisciplinary treatment, including crown lengthening, osteotomy, root canal treatment, fiberglass post insertion, and reattachment of the fracture segment was performed. A follow-up examination at 10 months later revealed that the tooth was completely reestablished both functionally and esthetically and that there was no periapical pathosis or discomfort. This outcome suggests that if a patient seeks a dental consultation soon after a complex crown-root fracture has occurred, and if the broken tooth segment is available, then reattachment offers an economical and simple treatment option which will allow immediate restoration of functionality and esthetic standards. Continued follow-up should form part of such a treatment plan to allow long-term pulp vitality and periodontal health status to be monitored.
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Recubrimiento Dental Adhesivo , Fracturas de los Dientes , Humanos , Adulto , Raíz del Diente/lesiones , Incisivo , Estética Dental , Fracturas de los Dientes/terapia , Tratamiento del Conducto Radicular , Corona del Diente , Restauración Dental PermanenteRESUMEN
There is no conclusive evidence regarding a causal relationship between periodontitis and atherosclerosis. In this study, we examined the microbiome in the oral cavity and atheromatous plaques from atherosclerosis patients with or without periodontitis to investigate the role of oral bacteria in the formation of atheromatous plaques. We chose four patients with and without periodontitis, who had undergone carotid endarterectomy. Bacterial samples were extracted from the tongue surface, from periodontal pocket (during the oral examination), and from the atheromatous plaques (APs). We investigated the general and oral conditions from each patient and performed next-generation sequencing (NGS) analysis for all bacterial samples. There were no significant differences between both groups concerning general conditions. However, the microbiome patterns of the gingival pocket showed differences depending on the absence or presence of periodontitis, while those of the tongue surface were relatively similar. The microbiome pattern of the atheromatous plaques was entirely different from that on the tongue surface and gingival pocket, and oral bacteria were seldom detected. However, the microbiome pattern in atheromatous plaques was different in the presence or absence of periodontitis. These results suggested that oral bacteria did not affect the formation of atheromatous plaques directly.
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Microbiota , Periodontitis , Placa Aterosclerótica , ADN Bacteriano/genética , HumanosRESUMEN
Dental caries is a type of oral microbiome dysbiosis and biofilm infection that affects oral and systemic conditions. For healthy life expectancy, natural bacteriostatic products are ideal for daily and lifetime use as anti-oral infection agents. This study aimed to evaluate the inhibitory effects of abietic acid, a diterpene derived from pine rosin, on the in vitro growth of cariogenic bacterial species, Streptococcus mutans. The effective minimum inhibitory concentration of abietic acid was determined through observation of S. mutans growth, acidification, and biofilm formation. The inhibitory effects of abietic acid on the bacterial membrane were investigated through the use of in situ viability analysis and scanning electron microscopic analysis. Cytotoxicity of abietic acid was also examined in the context of several human cell lines using tetrazolium reduction assay. Abietic acid was found to inhibit key bacterial growth hallmarks such as colony forming ability, adenosine triphosphate activity (both planktonic and biofilm), acid production, and biofilm formation. Abietic acid was identified as bacteriostatic, and this compound caused minimal damage to the bacterial membrane. This action was different from that of povidone-iodine or cetylpyridinium chloride. Additionally, abietic acid was significantly less cytotoxic compared to povidone-iodine, and it exerted lower toxicity towards epithelial cells and fibroblasts compared to that against monocytic cells. These data suggest that abietic acid may prove useful as an antibacterial and antibiofilm agent for controlling S. mutans infection.
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Antiinfecciosos , Caries Dental , Abietanos , Antibacterianos , Biopelículas , Humanos , Pruebas de Sensibilidad Microbiana , Streptococcus mutansRESUMEN
The recruitment of tissue-resident stem cells is important for wound regeneration. Periodontal ligament cells (PDL cells) are heterogeneous cell populations with stemness features that migrate into wound sites to regenerate periodontal fibres and neighbouring hard tissues. Cell migration is regulated by the local microenvironment, coordinated by growth factors and the extracellular matrix (ECM). Integrin-mediated cell adhesion to the ECM provides essential signals for migration. We hypothesized that PDL cell migration could be enhanced by selective expression of integrins. The migration of primary cultured PDL cells was induced by platelet-derived growth factor-BB (PDGF-BB). The effects of blocking specific integrins on migration and ECM adhesion were investigated based on the integrin expression profiles observed during migration. Up-regulation of integrins α3, α5, and fibronectin was identified at distinct localizations in migrating PDL cells. Treatment with anti-integrin α5 antibodies inhibited PDL cell migration. Treatment with anti-integrin α3, α3-blocking peptide, and α3 siRNA significantly enhanced cell migration, comparable to treatment with PDGF-BB. Furthermore, integrin α3 inhibition preferentially enhanced adhesion to fibronectin via integrin α5. These findings indicate that PDL cell migration is reciprocally regulated by integrin α3-mediated inhibition and α5-mediated promotion. Thus, targeting integrin expression is a possible therapeutic strategy for periodontal regeneration.
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Movimiento Celular , Matriz Extracelular/metabolismo , Integrina alfa3/metabolismo , Integrinas/metabolismo , Ligamento Periodontal/fisiología , Adhesión Celular , Proliferación Celular , Células Cultivadas , Perfilación de la Expresión Génica , Humanos , Integrina alfa3/genética , Integrinas/genética , Ligamento Periodontal/citología , Ligamento Periodontal/metabolismoRESUMEN
An insertion sequence, IS1598 (IsPg4) has been found in virulent strains of Porphyromonas gingivalis in a murine abscess model. The present study was performed to investigate the effects of genetic rearrangements by IS1598 on the phenotypic characteristics of the virulent strains. For this purpose, we searched for a common insertion site of IS1598 among the virulent strains. Through cloning and database search, a common insertion site was identified beside an nrdD-like gene in the virulent FDC 381, W83 and W50 strains. In this region, predicted promoters of the nrdD-like gene and IS1598 are located in tandem, and accumulation of nrdD-like gene mRNA was 5-fold higher in virulent strains (W83, W50, FDC 381) than avirulent strains (ATCC33277, SU63, SUNY1021, ESO59 without IS1598). The role of the nrdD-like gene in virulence of P. gingivalis was investigated by constructing a nrdD-deficient mutant. In the murine abscess model, the parental W83 strain produced necrotic abscesses, while the nrdD-deficient mutant had almost lost this ability. Insertion of IS1598 into the nrdD-like gene promoter region may be related to the phenotypic differences in virulence among P. gingivalis strains through upregulation of the expression of this gene.
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Proteínas Bacterianas/metabolismo , Porphyromonas gingivalis/clasificación , Porphyromonas gingivalis/patogenicidad , Ribonucleótido Reductasas/metabolismo , Regulación hacia Arriba/fisiología , Absceso/microbiología , Proteínas Bacterianas/genética , Regulación Enzimológica de la Expresión Génica , Genes Bacterianos , Genoma Bacteriano , Humanos , Mutagénesis Insercional , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ribonucleótido Reductasas/genética , VirulenciaRESUMEN
Interleukin (IL)-6 is a proinflammatory cytokine that performs a wide variety of biological functions, including important roles in the progression of chronic inflammatory diseases such as periodontal disease. (+)-Terrein, a secondary bioactive fungal metabolite isolated from Aspergillus terreus, has various biological activities; however, its anti-inflammatory effects are still unknown. The purpose of this study was to examine the effect of synthetic (+)-terrein on IL-6 signaling and related protein production in human gingival fibroblasts. To our knowledge, this study is the first to report that synthetic (+)-terrein is not cytotoxic at concentrations less than 20 µM and suppresses IL-6/soluble IL-6 receptor (sIL-6R)-induced phosphorylation of signal transducer and activator of transcription-3, extracellular signal-regulated kinase 1/2, and c-jun N-terminal kinase 1/2-signaling proteins that are downstream of IL-6 signaling. In addition, synthetic (+)-terrein suppresses IL-6/sIL-6R-induced vascular endothelial growth factor (VEGF) secretion in a concentration-dependent manner (p<0.01). These data suggest that synthetic (+)-terrein has potential anti-IL-6 signaling activity and suppresses VEGF-associated inflammatory disease progression.
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Ciclopentanos/síntesis química , Ciclopentanos/farmacología , Fibroblastos/efectos de los fármacos , Encía/citología , Interleucina-6/antagonistas & inhibidores , Receptores de Interleucina-6/antagonistas & inhibidores , Factores de Crecimiento Endotelial Vascular/metabolismo , Ciclopentanos/química , Relación Dosis-Respuesta a Droga , Fibroblastos/metabolismo , Humanos , Interleucina-6/metabolismo , Estructura Molecular , Receptores de Interleucina-6/metabolismo , Solubilidad , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
Introduction: Vital pulp therapy (VPT) is performed to preserve dental pulp. However, the biocompatibility of the existing materials is of concern. Therefore, novel materials that can induce pulp healing without adverse effects need to be developed. Resolvin D2 (RvD2), one of specialized pro-resolving mediators, can resolve inflammation and promote the healing of periapical lesions. Therefore, RvD2 may be suitable for use in VPT. In the present study, we evaluated the efficacy of RvD2 against VPT using in vivo and in vitro models. Methods: First molars of eight-week-old male Sprague-Dawley rats were used for pulpotomy. They were then divided into three treatment groups: RvD2, phosphate-buffered saline, and calcium hydroxide groups. Treatment results were assessed using radiological, histological, and immunohistochemical (GPR18, TNF-α, Ki67, VEGF, TGF-ß, CD44, CD90, and TRPA1) analyses. Dental pulp-derived cells were treated with RvD2 in vitro and analyzed using cell-proliferation and cell-migration assays, real-time PCR (Gpr18, Tnf-α, Il-1ß, Tgf-ß, Vegf, Nanog, and Trpa1), ELISA (VEGF and TGF-ß), immunocytochemistry (TRPA1), and flow cytometry (dental pulp stem cells: DPSCs). Results: The formation of calcified tissue in the pulp was observed in the RvD2 and calcium hydroxide groups. RvD2 inhibited inflammation in dental pulp cells. RvD2 promoted cell proliferation and migration and the expression of TGF-ß and VEGF in vitro and in vivo. RvD2 increased the number of DPSCs. In addition, RvD2 suppressed TRPA1 expression as a pain receptor. Conclusion: RvD2 induced the formation of reparative dentin, anti-inflammatory effects, and decreased pain, along with the proliferation of DPSCs via the expression of VEGF and TGF-ß, on the pulp surface in pulpotomy models.
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BACKGROUND/AIM: Malignant melanoma is a tumor with a poor prognosis that can metastasize distally at an early stage. Terrein, a metabolite produced by Aspergillus terreus, suppresses the expression of angiogenin, an angiogenic factor. However, the pharmacological effects of natural terrein have not been elucidated, because only a small amount of terrein can be extracted from large fungal cultures. In this study, we investigated the antineoplastic effects of terrein on human malignant melanoma cells and its underlying mechanisms. MATERIALS AND METHODS: Human malignant melanoma cell lines were cultured in the presence of terrein and analyzed. Angiogenin production was evaluated using ELISA. Ribosome biosynthesis was evaluated using silver staining of the nucleolar organizer region. Intracellular signaling pathways were analyzed using western blotting. Malignant melanoma cells were transplanted subcutaneously into the backs of nude mice. The tumors were removed at 5 weeks and analyzed histopathologically. RESULTS: Terrein inhibited angiogenin expression, proliferation, migration, invasion, and ribosome biosynthesis in malignant melanoma cells. Terrein was shown to inhibit tumor growth and angiogenesis in animal models. CONCLUSION: This study demonstrated that terrein has anti-tumor effects against malignant melanoma. Furthermore, chemically synthesized non-natural terrein can be mass-produced and serve as a novel potential anti-tumor drug candidate.
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Proliferación Celular , Melanoma , Ratones Desnudos , Ribonucleasa Pancreática , Humanos , Animales , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , Melanoma/patología , Ribonucleasa Pancreática/metabolismo , Ratones , Proliferación Celular/efectos de los fármacos , Línea Celular Tumoral , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Ensayos Antitumor por Modelo de Xenoinjerto , Movimiento Celular/efectos de los fármacos , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , CiclopentanosRESUMEN
Periodontal disease is highly prevalent in both humans and dogs. Although there have been reports of cross-infection of periodontopathic bacteria, methods for assessing it have yet to be established. The actual status of cross-infection remains to be seen. The purpose of this study was to evaluate the utility of bacterial DNA and serum immunoglobulin G (IgG) antibody titer assays to assess infection of human-pathogenic and dog-pathogenic Porphyromonas species in dogs. Four experimental beagles were used for establishing methods. Sixty-six companion dogs at veterinary clinics visiting for treatment and prophylaxis of periodontal disease were used and divided into healthy, gingivitis, and periodontitis groups. Periodontal pathogens such as Porphyromonas gingivalis and Porphyromonas gulae were investigated as target bacteria. DNA levels of both bacteria were measured using species-specific primers designed for real-time polymerase chain reaction (PCR). Serum IgG titers of both bacteria were measured by enzyme-linked immunosorbent assay (ELISA). PCR primers were confirmed to have high sensitivity and specificity. However, there was no relationship between the amount of bacterial DNA and the severity of the periodontal disease. In addition, dogs with periodontitis had higher IgG titers against both bacteria compared to dogs in the healthy and gingivitis groups; there was cross-reactivity between the two bacteria. Receiver operating characteristic (ROC) analysis of IgG titers against both bacteria showed high sensitivity (>90 %) and specificity (>75 %). Since both bacteria were distinguished by DNA assays, the combination of these assays may be useful in the evaluation of cross-infection.
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Dental caries are an oral infectious disease that can affect human health both orally and systemically. It remains an urgent issue to establish a novel antibacterial method to prevent oral infection for a healthy life expectancy. The aim of this study was to evaluate the inhibitory effects of novel iron chelators, super-polyphenols (SPs), on the cariogenic bacterium Streptococcus mutans, in vitro. SPs were developed to reduce the side effects of iron chelation therapy and were either water-soluble or insoluble depending on their isoforms. We found that SP6 and SP10 inhibited bacterial growth equivalent to povidone-iodine, and viability tests indicated that their effects were bacteriostatic. These results suggest that SP6 and SP10 have the potential to control oral bacterial infections such as Streptococcus mutans.
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Apical periodontitis is an inflammatory response caused by pulp infection. It induces bone resorption in the apical and periapical regions of the tooth. The most conservative approach to treat this condition is nonsurgical endodontic treatment. However, clinical failure has been reported with this approach; thus, alternative procedures are required. This review highlights recent literature regarding advanced approaches for the treatment of apical periodontitis. Various therapies, including biological medications, antioxidants, specialized pro-resolving lipid mediators, and stem cell therapy, have been tested to increase the success rate of treatment for apical periodontitis. Some of these approaches remain in the in vivo phase of research, while others have just entered the translational research phase to validate clinical application. However, a detailed understanding of the molecular mechanisms that occur during development of the immunoinflammatory reaction in apical periodontitis remains unclear. The aim of this review was to summarize advanced approaches for the treatment of apical periodontitis. Further research can confirm the potential of these alternative nonsurgical endodontic treatment approaches.
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Current periodontal treatment focuses on the mechanical removal of the source of infection, such as bacteria and their products, and there is no approach to control the host inflammatory response that leads to tissue destruction. In order to control periodontal inflammation, we have previously reported the optimization of (+)-terrein synthesis methods and the inhibitory effect of (+)-terrein on osteoclast differentiation in vitro. However, the pharmacological effect of (+)-terrein in vivo in the periodontitis model is still unknown. In this study, we investigated the effect of synthetic (+)-terrein on inflammatory bone resorption using a ligature-induced periodontitis mouse model. Synthetic (+)-terrein (30 mg/kg) was administered intraperitoneally twice a week to the mouse periodontitis model. The control group was treated with phosphate buffer. One to two weeks after the induction of periodontitis, the periodontal tissues were harvested for radiological evaluation (micro-CT), histological evaluation (HE staining and TRAP staining), and the evaluation of inflammatory cytokine production in the periodontal tissues and serum (quantitative reverse-transcription PCR, ELISA). The synthetic (+)-terrein-treated group suppressed alveolar bone resorption and the number of osteoclasts in the periodontal tissues compared to the control group (p < 0.05). In addition, synthetic (+)-terrein significantly suppressed both mRNA expression of TNF-α in the periodontal tissues and the serum concentration of TNF-α (both p < 0.05). In conclusion, we have demonstrated that synthetic (+)-terrein abrogates alveolar bone resorption via the suppression of TNF-α production and osteoclast differentiation in vivo. Therefore, we could expect potential clinical effects when using (+)-terrein on inflammatory bone resorption, including periodontitis.
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A series of isobutenyl compounds possessing various alkyl chain lengths (C(n)-1) with a carbon number of n = 14-21 were synthesized and their two-dimensional (2D) structures were systematically studied using scanning tunnelling microscopy (STM) at a highly oriented pyrolytic graphite (HOPG)/solvent interface. Two kinds of solvent, such as 1-phenyloctane (PO) and 1-phenylnonane (PN), were selected to examine the 2D structures by changing the alkyl chain length of the isobutenyl compounds. At the HOPG/PO interface, C(n)-1 molecules with shorter alkyl chains (n = 14-17) showed the same zig-zag shaped 2D structure regardless of the alkyl chain length, whereas an odd-even effect was recognized in C(n)-1 compounds with longer alkyl chains (n = 18-21) displaying the wavy and tripod structures, alternately. This odd-even effect was also observed at the HOPG/PN interface rather more distinctly. These results suggest that there is a specific alkyl chain length range that shows the odd-even effect in the present 2D system. After a tandem Claisen rearrangement (TCR), the 2D structures of all the C(n)-2 compounds formed were converged into the same linear structure, i.e. the odd-even effect was cancelled by the conformational limitation induced by the TCR.
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Alquenos/química , Alquenos/síntesis química , Microscopía de Túnel de Rastreo , Estructura Molecular , Solventes/químicaRESUMEN
Neutrophils from people with poorly controlled diabetes present a primed phenotype and secrete excessive superoxide. Phospholipase A(2) (PLA(2))-derived arachidonic acid (AA) activates the assembly of NADPH oxidase to generate superoxide anion. There is a gap in the current literature regarding which PLA(2) isoform regulates NADPH oxidase activation. The aim of this study was to identify the PLA(2) isoform involved in the regulation of superoxide generation in neutrophils and investigate if PLA(2) mediates priming in response to pathologic hyperglycemia. Neutrophils were isolated from people with diabetes mellitus and healthy controls, and HL60 neutrophil-like cells were grown in hyperglycemic conditions. Incubating neutrophils with the Ca(2+)-independent PLA(2) (iPLA(2)) inhibitor bromoenol lactone (BEL) completely suppressed fMLP-induced generation of superoxide. The nonspecific actions of BEL on phosphatidic acid phosphohydrolase-1, p47(phox) phosphorylation, and apoptosis were ruled out by specific assays. Small interfering RNA knockdown of iPLA(2) inhibited superoxide generation by neutrophils. Neutrophils from people with poorly controlled diabetes and in vitro incubation of neutrophils with high glucose and the receptor for advanced glycation end products ligand S100B greatly enhanced superoxide generation compared with controls, and this was significantly inhibited by BEL. A modified iPLA(2) assay, Western blotting, and PCR confirmed that there was increased iPLA(2) activity and expression in neutrophils from people with diabetes. AA (10 microM) partly rescued the inhibition of superoxide generation mediated by BEL, confirming that NADPH oxidase activity is, in part, regulated by AA. This study provides evidence for the role of iPLA(2) in enhanced superoxide generation in neutrophils from people with diabetes mellitus and presents an alternate pathway independent of protein kinase C and phosphatidic acid phosphohydrolase-1 hydrolase signaling.
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Calcio/sangre , Diabetes Mellitus Tipo 1/inmunología , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 2/inmunología , Diabetes Mellitus Tipo 2/metabolismo , Fosfolipasas A2 Grupo VI/sangre , Neutrófilos/enzimología , Estrés Oxidativo/inmunología , Adulto , Calcio/fisiología , Diabetes Mellitus Tipo 1/enzimología , Diabetes Mellitus Tipo 2/enzimología , Femenino , Marcación de Gen , Fosfolipasas A2 Grupo VI/antagonistas & inhibidores , Fosfolipasas A2 Grupo VI/genética , Fosfolipasas A2 Grupo VI/fisiología , Células HL-60 , Humanos , Masculino , Persona de Mediana Edad , Neutrófilos/inmunología , Fosfatidato Fosfatasa/fisiología , Proteína Quinasa C/fisiología , Transducción de Señal/genética , Transducción de Señal/inmunología , Superóxidos/sangre , Regulación hacia Arriba/inmunologíaRESUMEN
The study aims to reveal the composition of subgingival bacteria in monozygotic twins with discordant in severity and progression risk of periodontitis. Microbiome analysis indicated that most bacteria were heritable but differed in their abundance and immune response. The dysbiotic bacteria can be considered as risk markers for periodontitis progression.
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Resolvins are endogenous lipid mediators that actively regulate the resolution of acute inflammation. Resolvin E1 (RvE1; (5S,12R,18R)-trihydroxy-6Z,8E,10E,14Z,16E-eicosapentaenoic acid) is an endogenous anti-inflammatory and pro-resolving mediator derived from eicosapentaenoic acid that regulates leukocyte migration and enhances macrophage phagocytosis of apoptotic neutrophils to resolve inflammation. In the inflammatory milieu, RvE1 mediates counter-regulatory actions initiated via specific G protein-coupled receptors. Here, we have identified RvE1-specific signaling pathways initiated by the RvE1 receptor ChemR23. RvE1 stimulated phosphorylation of Akt that was both ligand- and receptor-dependent. RvE1 regulated Akt phosphorylation in a time (0-15 min)- and dose-dependent (0.01-100 nm) manner in human ChemR23-transfected Chinese hamster ovary cells. RvE1 stimulated phosphorylation of both Akt and a 30-kDa protein, a downstream target of Akt, identified using a phospho-Akt substrate antibody. The 30-kDa protein was identified as ribosomal protein S6, a translational regulator, and its phosphorylation was inhibited by a phosphatidylinositol 3-kinase (PI3K) inhibitor (wortmannin) and an ERK inhibitor (PD98059) but not by a p38-MAPK inhibitor (SB203580). Ribosomal protein S6 is a downstream target of the PI3K/Akt signaling pathway as well as the Raf/ERK pathway. In ChemR23-expressing differentiated HL60 cells, RvE1 also stimulated the phosphorylation of ribosomal protein S6. In addition, RvE1 enhanced phagocytosis of zymosan A by human macrophages, which are inhibited by PD98059 and rapamycin (mTOR inhibitor). These results indicate that RvE1 initiates direct activation of ChemR23 and signals receptor-dependent phosphorylation. These phosphorylation-signaling pathways identified for RvE1 receptor-ligand interactions underscore the importance of endogenous pro-resolving agonists in resolving acute inflammation.
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Ácido Eicosapentaenoico/análogos & derivados , Receptores de Quimiocina/química , Animales , Células CHO , Diferenciación Celular , Cricetinae , Cricetulus , Ácido Eicosapentaenoico/química , Flavonoides/farmacología , Células HL-60 , Humanos , Inflamación , Lípidos/química , Macrófagos/metabolismo , Fagocitosis , Fosforilación , Receptores de Quimiocina/metabolismo , Sirolimus/farmacología , Zimosan/farmacologíaRESUMEN
Osteoporosis is a common disease characterized by a systemic impairment of bone mass and microarchitecture that results in fragility fractures. Severe bone loss due to osteoporosis triggers pathological fractures and consequently decreases the daily life activity and quality of life. Therefore, prevention of osteoporosis has become an important issue to be addressed. We have reported that the fungal secondary metabolite (+)-terrein (TER), a natural compound derived from Aspergillus terreus, has shown receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation by suppressing nuclear factor of activated T-cell 1 (NFATc1) expression, a master regulator of osteoclastogenesis. TER has been shown to possess extensive biological and pharmacological benefits; however, its effects on bone metabolism remain unclear. In this study, we investigated the effects of TER on the femoral bone metabolism using a mouse-ovariectomized osteoporosis model (OVX mice) and then on RANKL signal transduction using mouse bone marrow macrophages (mBMMs). In vivo administration of TER significantly improved bone density, bone mass, and trabecular number in OVX mice (p < 0.01). In addition, TER suppressed TRAP and cathepsin-K expression in the tissue sections of OVX mice (p < 0.01). In an in vitro study, TER suppressed RANKL-induced phosphorylation of PKCα/ßII, which is involved in the expression of NFATc1 (p < 0.05). The PKC inhibitor, GF109203X, also inhibited RANKL-induced osteoclastogenesis in mBMMs as well as TER. In addition, TER suppressed the expression of osteoclastogenesis-related genes, such as Ocstamp, Dcstamp, Calcr, Atp6v0d2, Oscar, and Itgb3 (p < 0.01). These results provide promising evidence for the potential therapeutic application of TER as a novel treatment compound against osteoporosis.