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Much of the information about the size and shape of aerosols forming haze and the cloud layer of Venus is obtained from indirect inferences from nephelometers on probes and from the analysis of the variation of polarization with the phase angle and the glory feature from images of Venus. The microscopic imaging of Venus' aerosols has recently been advocated. Direct measurements from a fluorescence microscope can provide information on the morphology, density, and biochemical characteristics of the particles; thus, fluorescence microscopy is attractive for in situ particle characterization of the Venus cloud layer. Fluorescence imaging of Venus cloud particles presents several challenges owing to the sulfuric acid composition and corrosive effects. In this article, we identify the challenges and describe our approach to overcoming them for a fluorescence microscope based on an in situ biochemical and physical characterization instrument for use in the clouds of Venus from a suitable aerial platform. We report that pH adjustment using alkali was effective for obtaining fluorescence images and that fluorescence attenuation was observed after the adjustment, even when the acidophile suspension in concentrated sulfuric acid was used as a sample.
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Atmósfera , Venus , Aerosoles , Atmósfera/química , Microscopía FluorescenteRESUMEN
BACKGROUND: A brain abscess is a focal infection in which abscesses form in the brain. A brain abscess is a rare but fatal disease when rupture occurs into the ventricles. We report a case of multiple brain abscesses caused by a hematogenous infection from the apical periodontitis of deciduous teeth. CASE PRESENTATION: The patient was a 7-years and 8-months-old male with congenital heart disease. The patient sought medical attention due to fever and headache, for which he was started on three antibiotics with a diagnosis of multiple brain abscesses. Given that apical periodontitis of deciduous teeth was strongly suspected as the source of the brain abscess, the deciduous teeth were extracted. Immediately after deciduous teeth extraction, the patient's headache and neurological symptoms disappeared. CONCLUSIONS: After teeth extraction, a clear shrinkage of the brain abscess was observed, and the patient was discharged from the hospital.
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Absceso Encefálico , Cardiopatías Congénitas , Periodontitis Periapical , Absceso Encefálico/diagnóstico por imagen , Absceso Encefálico/etiología , Cefalea/complicaciones , Cardiopatías Congénitas/complicaciones , Humanos , Lactante , Masculino , Periodontitis Periapical/complicaciones , Diente PrimarioRESUMEN
Special AT-rich sequence-binding protein 2 (SATB2)-associated syndrome (SAS) is characterized by alterations of SATB2. Its clinical features include intellectual disability and craniofacial abnormalities, such as cleft palate, dysmorphic features, and dental abnormalities. Here, we describe three previously undiagnosed, unrelated patients with SAS who exhibited dental abnormalities, including multiple odontomas. Although isolated odontomas are common, multiple odontomas are rare. Individuals in families 1 and 3 underwent whole-exome sequencing. Patient 2 and parents underwent targeted amplicon sequencing. On the basis of the hg19/GRCh37 reference and the RefSeq mRNA NM_001172517, respective heterozygous mutations were found and validated in Patients 1, 2, and 3: a splice-site mutation (chr2:g.200137396C > T, c.1741-1G > A), a nonsense mutation (chr2:g.200213750G > A, c.847C > T, p.R283*), and a frame-shift mutations (chr2:g.200188589_200188590del, c.1478_1479del, p.Q493Rfs*19). All mutations occurred de novo. The mutations in Patients 1 and 3 were novel; the mutation in Patient 2 has been described previously. Tooth mesenchymal cells derived from Patient 2 showed diminished SATB2 expression. Multiple odontomas were evident in the patients in this report; however, this has not been recognized previously as a SAS-associated phenotype. We propose that multiple odontomas be considered as an occasional manifestation of SAS.
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Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Proteínas de Unión a la Región de Fijación a la Matriz/genética , Odontoma/diagnóstico , Odontoma/genética , Fenotipo , Factores de Transcripción/genética , Adolescente , Alelos , Análisis Mutacional de ADN , Exones , Femenino , Genotipo , Humanos , Masculino , Mutación , Linaje , Síndrome , Secuenciación del Exoma , Adulto JovenRESUMEN
Non-steroidal anti-inflammatory drugs (NSAIDs) exhibit several divergent biological effects. In this study, we investigated the effect of indomethacin on melanin synthesis using B16F1 melanoma cells. Indomethacin inhibited α-melanocyte stimulating hormone (α-MSH)-enhanced melanin synthesis in a dose-dependent manner. Western blotting analysis revealed that indomethacin significantly suppressed tyrosinase and Mitf protein levels. In a luciferase reporter assay, we found that indomethacin reduced tyrosinase promoter activity. Moreover, real-time RT-PCR analysis showed that indomethacin lowered mRNA levels of melanogenic genes, including Mitf. Together, our findings indicate that indomethacin inhibits melanogenesis via the suppression of Mitf transcription.
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Regulación hacia Abajo/efectos de los fármacos , Indometacina/farmacología , Melaninas/biosíntesis , Factor de Transcripción Asociado a Microftalmía/genética , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Espacio Intracelular/efectos de los fármacos , Espacio Intracelular/metabolismo , Melanoma Experimental/patología , Ratones , Monofenol Monooxigenasa/genética , Monofenol Monooxigenasa/metabolismo , Regiones Promotoras Genéticas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transcripción Genética/efectos de los fármacosRESUMEN
We present a comparative study of the methods used in the search for extraterrestrial microorganism life, including a summary table where different life-detection techniques can be easily compared as an aid to mission and instrument design aimed at life detection. This is an extension of previous study, where detection techniques for a series of target characteristics and molecules that could constitute a positive life detection were evaluated. This comparison has been extended with a particular consideration to sources of false positives, the causes of negative detection, the results of detection techniques when presented regarding terrestrial life, and additional science objectives that could be achieved outside the primary aim of detecting life. These additions address both the scientific and programmatic side of exploration mission design, where a successful proposal must demonstrate probable outcomes and be able to return valuable results even if no life is found. The applicability of the life detection techniques is considered for Earth life, Earth-independent life (life emerging independently from that on Earth,) and Earth-kin life (sharing a common ancestor with life on Earth), and techniques effective in detecting Earth life should also be useful in the detection of Earth-kin life. However, their applicability is not guaranteed for Earth-independent life. As found in our previous study, there exists no realistic single detection method that can conclusively determine the discovery of extraterrestrial life, and no method is superior to all others. In this study, we further consider combinations of detection techniques and identify imaging as a valuable addition to molecule detection methods, even in cases where there is insufficient resolution to observe the detailed morphology of a microbial cell. The search for extraterrestrial life is further divided into a survey-and-detection and analysis-and-conclusion step. These steps benefit from different detection techniques, but imaging is necessary for both parts.
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Marte , Vuelo Espacial , Exobiología/métodos , Medio Ambiente Extraterrestre , Sistema Solar , Planeta TierraRESUMEN
Studies of mice lacking MHC class I (MHC I)-associated proteins have demonstrated a role for MHC I in neurodevelopment. A central question arising from these observations is whether neuronal recognition of MHC I has specificity for the MHC I allele product and the peptide presented. Using a well-established embryonic retina explant system, we observed that picomolar levels of a recombinant self-MHC I molecule inhibited neurite outgrowth. We then assessed the neurobiological activity of a panel of recombinant soluble MHC Is, consisting of different MHC I heavy chains with a defined self- or nonself-peptide presented, on cultured embryonic retinas from mice with different MHC I haplotypes. We observed that self-MHC I allele products had greater inhibitory neuroactivity than nonself-MHC I molecules, regardless of the nature of the peptide presented, a pattern akin to MHC I recognition by some innate immune system receptors. However, self-MHC I molecules had no effect on retinas from MHC I-deficient mice. These observations suggest that neuronal recognition of MHC I may be coordinated with the inherited MHC I alleles, as occurs in the innate immune system. Consistent with this notion, we show that MHC I and MHC I receptors are coexpressed by precursor cells at the earliest stages of retina development, which could enable such coordination.
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Alelos , Presentación de Antígeno , Antígenos de Histocompatibilidad Clase I/genética , Neuronas/inmunología , Péptidos/inmunología , Animales , Autoantígenos/inmunología , Células Madre Embrionarias , Inmunidad Innata , Ratones , Neuritas/inmunología , Neuronas/citología , Retina/embriologíaRESUMEN
The detection and analysis of extraterrestrial life are important issues of space science. Mars is among the most important planets to explore for extraterrestrial life, owing both to its physical properties and to its ancient and present environments as revealed by previous exploration missions. In this paper, we present a comparative study of methods for detecting extraterrestrial life and life-related substances. To this end, we have classified and summarized the characteristics targeted for the detection of extraterrestrial life in solar system exploration mission and the methods used to evaluate them. A summary table is presented. We conclude that at this moment (i) there is no realistic single detection method capable of concluding the discovery of extraterrestrial life, (ii) no single method has an advantage over the others in all respects, and (iii) there is no single method capable of distinguishing extraterrestrial life from terrestrial life. Therefore, a combination of complementary methods is essential. We emphasize the importance of endeavoring to detect extraterrestrial life without overlooking possible alien life forms, even at the cost of tolerating false positives. Summaries of both the targets and the detection methods should be updated continuously, and comparative studies of both should be pursued. Although this study assumes Mars to be a model site for the primary environment for life searches, both the targets and detection methods described herein will also be useful for searching for extraterrestrial life in any celestial environment and for the initial inspection of returned samples.
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Marte , Vuelo Espacial , Exobiología , Medio Ambiente Extraterrestre , Planetas , Sistema SolarRESUMEN
Stem cells from human exfoliated deciduous teeth (SHED) are mesenchymal stem cells with multipotent differentiation potential present in the dental pulp tissue of the deciduous teeth. SHED produce secretions that have immunomodulatory and regenerative functions. In the present study, we investigated the effects of SHED-conditioned medium (SHED-CM) on osteopenia induced by the ovariectomy (OVX) phenotype and its corresponding immunological changes. Eleven-week-old female C3H/HeJ mice were subjected to OVX. SHED-CM was administered intraperitoneally in these mice for 4 weeks starting immediately after OVX. SHED-CM improved bone mass after OVX and elevated the polarization of M2 macrophages in the peritoneal cavity. SHED-CM also suppressed an OVX-induced increase in interferon-γ (INF-γ) and interleukin-17 (IL-17) concentrations in the peripheral blood. Inhibition of M2 macrophage polarization with neutralizing antibodies did not reduce the concentration of IFN-γ and IL-17 in peripheral blood, which were increased by OVX, and did not alleviate osteopenia induced by the OVX phenotype. Mechanistically, these findings suggest that SHED-CM alleviates bone resorption by suppressing the activation of IFN-γ and IL-17 cells by polarizing M2 macrophages. In conclusion, our data indicate that SHED-CM contains active secretions that may have promising efficacy to ameliorate OVX-induced osteopenia. We suggest that SHED-CM has the potential to be used as a novel therapeutic agent to inhibit osteoporosis.
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OBJECTIVES: Osteoclasts can sense the surface topography of materials. However, it is difficult to identify the structural factors that affect osteoclast formation and its function. Furthermore, we hypothesized that the type of osteoclast precursor cells also affects osteoclastogenesis in the materials. In this study, we investigated the effects of defined micro/nanoscale patterns on osteoclastogenesis from bone marrow cells (BMCs). METHODS: Various cyclo-olefin polymer (COP) patterns were prepared using nanoimprinting. The effects of shape, size, and height of the patterns, and the wettability of the patterned surfaces on osteoclastogenesis from BMCs were evaluated in vitro. RESULTS: Osteoclast formation was promoted on pillars (diameter, 1 µm or 500 nm; height, 500 nm). Notably, osteoclastogenesis from BMCs was better promoted on hydrophobic pillars than on hydrophilic pillars. In contrast, decreased osteoclast formation was observed on the nanopillars (diameter, 100 nm; height, 200 nm). CONCLUSIONS: We demonstrated the promotion of osteoclast formation from BMCs on hydrophobic pillars with diameters of 1 µm and 500 nm. Some cellular behaviors in the patterns were dependent on the type of osteoclast precursor cells. The designed patterns are useful for designing the surface of dental implants or bone replacement materials with a controllable balance between osteoblast and osteoclast activities.
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Osteoclastos , Ligando RANK , Animales , Células de la Médula Ósea , Ratones , Osteoblastos , Osteogénesis , Ligando RANK/farmacologíaRESUMEN
Background: Denosumab, a human monoclonal antibody against receptor activator of nuclear factor-kappa B ligand (RANKL), is a novel bone antiresorptive agent used in patients with osteoporosis or metastatic bone cancer. Denosumab-related osteonecrosis of the jaw (DRONJ) has been recently reported in patients using denosumab. However, the mechanisms of DRONJ are not fully understood. Appropriate pathogenic mechanisms of DRONJ have yet to be established. Therefore, we investigated the pathogenesis of DRONJ in mice. Methods: Anti-mouse RANKL monoclonal antibody and melphalan were performed to create a mouse model of DRONJ-like lesions in female C57BL/6J mice. We examined the development of DRONJ-like lesions and immune function. Results: We showed that administration of anti-mouse RANKL monoclonal antibody and melphalan caused DRONJ-like lesions that recapitulated major clinical manifestations of the human disease, including the characteristic features of an open alveolar socket and exposed necrotic bone. In the analysis using a mouse model of DRONJ-like lesion, it was revealed that anti-mouse RANKL monoclonal antibody and melphalan suppress autoimmune regulator (AIRE) expression in the thymus and imbalanced T cell populations. Conclusion: This study suggests evidence of an immunity-based mechanism of DRONJ-like disease. This work may contribute to a better understanding of the pathogenesis of human DRONJ.
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Recent research has shown that platinum nanoparticles (nano-Pt) efficiently quench reactive oxygen species (ROS) as a reducing catalyst. ROS have been suggested to regulate receptor activator of NF-κB ligand (RANKL)-stimulated osteoclast differentiation. In the present study, we examined the direct effects of platinum nano-Pt on RANKL-induced osteoclast differentiation of murine pre-osteoclastic RAW 264.7 cells. The effect of the nano-Pt on the number of osteoclasts was measured and their effect on the mRNA expression for osteoclast differentiation was assayed using real-time PCR. Nano-Pt appeared to have a ROS-scavenging activity. Nano-Pt decreased the number of osteoclasts (2+ nuclei) and large osteoclasts (8+ nuclei) in a dose-dependent manner without affecting cell viability. In addition, this agent significantly blocked RANKL-induced mRNA expression of osteoclastic differentiation genes such as c-fms, NFATc1, NFATc2, and DC-STAMP as well as that of osteoclast-specific marker genes including MMP-9, Cath-K, CLC7, ATP6i, CTR, and TRAP. Although nano-Pt attenuated expression of the ROS-producing NOX-family oxidases, Nox1 and Nox4, they up-regulated expression of Nox2, the major Nox enzyme in macrophages. These findings suggest that the nano-Pt inhibit RANKL-stimulated osteoclast differentiation via their ROS scavenging property. The use of nano-Pt as scavengers of ROS that is generated by RANKL may be a novel and innovative therapy for bone diseases.
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Nanopartículas , Osteoclastos/efectos de los fármacos , Platino (Metal)/química , Especies Reactivas de Oxígeno/metabolismo , Animales , Diferenciación Celular/efectos de los fármacos , Línea Celular , Relación Dosis-Respuesta a Droga , Depuradores de Radicales Libres/administración & dosificación , Depuradores de Radicales Libres/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ratones , Osteoclastos/metabolismo , Platino (Metal)/administración & dosificación , Ligando RANK/antagonistas & inhibidores , ARN Mensajero/metabolismoRESUMEN
Working in a general hospital psychiatry department, the authors treat patients with psychiatric emergencies who also have physical complications. Three primary treatment paradigms exist. The first is the medical management of patients with psychiatric emergencies who also have physical illnesses. Physical complications may occur due to external injury, internal secretions, metabolic disease, and treatment for psychiatric emergencies. In such cases, patients require not only psychiatric treatment but also medical treatment for their physical symptoms or problems. The second pattern is the management of patients brought to the emergency department after a suicide attempt. In this case, the cause of the physical complications is action derived from suicidal ideation, and somatic therapy is given priority. The third pattern is the often difficult management of physical illness in patients who suffer from chronic psychiatric illness. In a general hospital with no department of psychiatry, psychiatric patients with physical emergencies are often unable to obtain appropriate diagnosis and treatment. There is a greater need for general hospitals able to manage psychiatric emergencies and their physical complications during medical treatment.
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Servicio de Educación en Hospital , Trastornos Mentales/complicaciones , Intento de Suicidio , Hospitales Generales , HumanosRESUMEN
This study examined the effects of N-acetylcysteine (NAC) on the inflammatory reactions of murine osteoblastic cells cultured on the 4-methacryloxyethyl trimellitate anhydride/methyl methacrylate (4-META/MMA)-based resin. Superbond C&B (SB) was used as the 4-META/MMA-based resin and placed in a 48-well cell culture plate. The cells were cultured in αMEM (control) as well as on SB and SB in αMEM with NAC (SB+NAC). They were examined using the WST-1 proliferation assay, real-time PCR, enzyme-linked immunosorbent assay (ELISA), intracellular reactive oxygen species (ROS) measurements, and cellular glutathione (GSH) detection. COX-2 and IL-6 gene expressions were upregulated in SB; however, they were suppressed by NAC. Furthermore, PGE2 production in the culture medium was increased in SB, whereas NAC decreased the PGE2 production. NAC lowered the ROS level in the culture medium and significantly increased the intracellular GSH level. The present in vitro study demonstrated that NAC might be effective for dental material detoxification.
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Acetilcisteína , Dinoprostona , Acetilcisteína/farmacología , Animales , Células Cultivadas , Metacrilatos , Ratones , Especies Reactivas de OxígenoRESUMEN
Modulation of the physiologically influential Na(+),K(+)-ATPase is a complex process involving a wide variety of factors. To determine the possible effects of the protein tyrosine phosphatase (PTP) inhibitors dephostatin and Et-3,4-dephostatin on human and pig, renal cells and enzymatic extracts, we treated our samples (15 min-24 h) with those PTP inhibitors (0-100 microM). PTP inhibitors were found to possess a concentration-dependent inhibition of Na(+),K(+)-ATPase activity in both human and pig samples. The inhibition was similarly demonstrated on all cellular, microsomal fraction and purified Na(+),K(+)-ATPase levels. Despite rigorous activity recovery attempts, the PTP inhibitors' effects were sustained on Na(+),K(+)-ATPase activity. Western blotting experiments revealed the expression of both alpha(1)- and beta(1)-subunits in both human and pig tissues. alpha(1)-Subunits possessed higher tyrosine phosphorylation levels with higher concentrations of PTP inhibitors. Meanwhile, serine/threonine residues of both alpha(1)- and beta(1)-subunits demonstrated diminished phosphorylation levels upon dephostatin treatment. Accordingly, we provide evidence that Na(+),K(+)-ATPase can be regulated through tyrosine phosphorylation of primarily their alpha(1)-subunits, using PTP inhibitors.
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Riñón/enzimología , Subunidades de Proteína/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Tirosina/metabolismo , Animales , Western Blotting , Catecolaminas/farmacología , Línea Celular Tumoral , Citometría de Flujo , Humanos , Hidroquinonas/farmacología , Compuestos Nitrosos/farmacología , Fosforilación/efectos de los fármacos , Proteínas Tirosina Fosfatasas/antagonistas & inhibidores , PorcinosRESUMEN
We developed a novel method to isolate functionally active single cells from environmental samples and named it the functional single-cell (FSC) isolation method. This method is based on a combination of substrate-responsive direct viable counts, live-cell staining with 5-carboxyfluorescein diacetate acetoxymethyl ester, and micromanipulation followed by cultivation in a medium. To evaluate this method, we applied it to study a denitrifying community in rice paddy soil. Similar denitrifier counts were obtained by the conventional most probable number analysis and our FSC isolation method. Using the FSC isolation method, 37 denitrifying bacteria were isolated, some of which harbored copper-containing nitrite reductase gene (nirK). The 16S rRNA gene analysis showed that members belonging to the genera Azospirillum and Ochrobactrum may be the major denitrifiers in the rice paddy soil. These results indicate that the FSC isolation method is a useful tool to obtain functionally active single cells from environmental samples.
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Bacterias/aislamiento & purificación , Técnicas Bacteriológicas , Oryza , Microbiología del Suelo , Azospirillum/clasificación , Azospirillum/aislamiento & purificación , Bacterias/clasificación , Bacterias/genética , ADN Bacteriano/genética , ADN Ribosómico/genética , Fluoresceínas , Nitratos/metabolismo , Ochrobactrum/clasificación , Ochrobactrum/aislamiento & purificación , Filogenia , ARN Ribosómico 16S/genéticaRESUMEN
We investigated the possible roles of estrogen on plasma membrane Ca(2+)-ATPase (PMCA) in human fibroblast-like synovial cells (HFLS) and mouse macrophage-like cells (RAW 264.7). Western blots revealed the expression of PMCA 2 and 4 in both cells. In vitro treatments with 17beta-estradiol for 24 hours resulted in a concentration dependent decrease in PMCA expression. Moreover, Ca(2+)-ATPase specific activity was similarly decreased with estrogen treatments. However, treatments for 1 hour in the presence or absence of cycloheximide demonstrated non-significant effects. These results suggest that estrogen has a modulatory role on Ca(2+) homeostasis through decreasing PMCA expression and abating their activity.
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Estradiol/farmacología , Macrófagos/efectos de los fármacos , ATPasas Transportadoras de Calcio de la Membrana Plasmática/metabolismo , Animales , Western Blotting , Calcio/metabolismo , Línea Celular , Cicloheximida/farmacología , Humanos , Macrófagos/citología , Macrófagos/enzimología , Ratones , Inhibidores de la Síntesis de la Proteína/farmacología , Líquido Sinovial/citología , Líquido Sinovial/efectos de los fármacos , Líquido Sinovial/enzimologíaRESUMEN
Clostridium tagluense strain A121T was isolated from a permafrost core in the Canadian High Arctic. This endospore-forming strain is a strictly anaerobic, Gram-positive, and psychrotolerant bacterium. This article describes the draft genome sequence of C. tagluense strain A121T.
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In submandibular gland atrophy, most acinar cells disappear by apoptosis, while many duct cells remain. The present study aimed to establish whether Bcl-2 and Bax, members of the Bcl-2 gene family, regulating the signalling pathway of apoptosis were involved in duct cell survival and acinar cell death in atrophic submandibular glands. The excretory duct of rat submandibular gland was doubly ligated with metal clips from 1 to 14 days to induce atrophy to the gland. The expressions of Bcl-2 and Bax in the atrophic submandibular gland were examined using immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). Immunohistochemically, Bcl-2 expression was identified in duct cells in the experimental glands at all time points. Some acinar cells showed Bax positivity 1 day after excretory duct ligation, and there were more Bax-positive acinar cells on days 3 and 5 when many apoptotic acinar cells were observed. Analysis by RT-PCR showed that the expression of mRNA for Bcl-2 became stronger as the glandular atrophy progressed and that Bax mRNA strongly expressed on days 1 and 3. These observations suggest that Bcl-2 inhibits duct cell apoptosis and Bax promotes apoptosis of acinar cells during atrophy of submandibular glands.
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Genes bcl-2 , Conductos Salivales/metabolismo , Transducción de Señal/genética , Glándula Submandibular/metabolismo , Glándula Submandibular/patología , Proteína X Asociada a bcl-2/genética , Animales , Apoptosis/genética , Atrofia/genética , Expresión Génica , Inmunohistoquímica , Etiquetado Corte-Fin in Situ , Ligadura , Masculino , Proteínas Proto-Oncogénicas c-bcl-2/análisis , Ratas , Ratas Wistar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Conductos Salivales/química , Conductos Salivales/patología , Glándula Submandibular/química , Proteína X Asociada a bcl-2/análisisRESUMEN
Matrix metalloproteinases (MMPs) play important roles in the invasion and metastasis to soft tissues of carcinomas including, oral squamous cell carcinomas (SCCs). Although, osteoclastic bone resorption is an important step in bone involvement in a variety of malignancies, the mechanism of bone involvement of oral SCC remains unclear. Once cancer cells arrest in bone, the bone is a storehouse of a variety of cytokines and growth factors and thus provides an extremely fertile environment for cell growth. The bone-invasive oral cancer cell line, BHY, transcriptionally expressed detectable levels of TGF-beta, IL-1beta, IL-8, parathyroid hormone-related protein (PTHrP) and vascular endothelial growth factor (VEGF) mRNAs and failed to express GM-CSF, IL-6, and TNF-alpha. Furthermore, the BHY-conditioned medium greatly upregulated IL-6 and RANKL/ODF mRNA expression in osteoblasts, suggesting a potential indirect stimulation of osteoclastogenesis via the osteogenic lineage. Seven out of eleven patients with carcinomas of the lower alveolus and gingiva showing infiltrative bone involvement expressed PTHrP mRNA. These data suggest that the occurrence of PTHrP may be an indication of developing oral malignant carcinomas.
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Carcinoma de Células Escamosas/patología , Diferenciación Celular , Neoplasias de la Boca/patología , Osteoblastos/citología , Osteoclastos/citología , Proteína Relacionada con la Hormona Paratiroidea/metabolismo , Animales , Células de la Médula Ósea , Carcinoma de Células Escamosas/metabolismo , Células Cultivadas , Técnicas de Cocultivo , Medios de Cultivo Condicionados/farmacología , Citocinas/metabolismo , Expresión Génica , Neoplasias Gingivales/genética , Neoplasias Gingivales/metabolismo , Neoplasias Gingivales/patología , Humanos , Ratones , Ratones Endogámicos C57BL , Neoplasias de la Boca/metabolismo , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Proteína Relacionada con la Hormona Paratiroidea/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Although it is known that mechanical stress to osteoblast and periodontal ligament cells suppresses osteoclast differentiation, little is known about the direct effect of mechanical stress on osteoclast differentiation. In this study, we examined the role of mechanical stress on osteoclast differentiation using murine pre-osteoclastic RAW264.7 cells treated with receptor activator of nuclear factor-kappaB ligand (RANKL). RAW cells were cultured with RANKL, and mechanical stress was applied for a given period. We counted the number of osteoclast cells which were tartrate-resistant acid phosphatase (TRAP)-positive and multinucleated (2 nuclei or more), and measured mRNA by RT-PCR. There was a decrease in the number of osteoclasts under mechanical stress compared with the number under no mechanical stress. The number of nuclei per osteoclast also decreased compared to the number of nuclei per osteoclast cultured with the application of mechanical stress. As the cells were cultured for a period of 1-7 days and/or for different periods of mechanical stress application, osteoclast differentiation decreased with mechanical stress and increased after removing mechanical stress. Expression of mRNA for the osteoclast-specific genes, TRAP, matrix metalloproteinase-9, cathepsin-K and calcitonin receptor, decreased with mechanical stress and was associated with the number of osteoclasts. Inducible nitric oxide synthase mRNA which inhibits osteoclast differentiation, increased with mechanical stress. In spite of the decrease in osteoclast number with mechanical stress, nuclear factor of activated T cell cytoplasmic 1 (NFATc1) and NFATc2 mRNA expression increased with mechanical stress. These findings indicate that mechanical stress directly suppresses osteoclast differentiation and increases NFATc1 and NFATc2 suggesting delayed differentiation.