RESUMO
Vitamin D3 up-regulated protein 1 (VDUP1) is a potent growth suppressor that inhibits tumor cell proliferation and cell cycle progression when overexpressed. In a previous study, we showed that VDUP1 knockout (KO) mice exhibited accelerated liver regeneration because such animals could effectively control the expression of cell cycle regulators that drive the G1-to-S phase progression. In the present study, we further investigated the role played by VDUP1 in initial priming of liver regeneration. To accomplish this, VDUP1 KO and wild-type (WT) mice were subjected to 70% partial hepatectomy (PH) and sacrificed at different times after surgery. The hepatic levels of TNF-alpha and IL-6 increased after PH, but there were no significant differences between VDUP1 KO and WT mice. Nuclear factor-kappaB (NF-kappaB), c-Jun-N-terminal kinase (JNK), and signal transducer and activator of transcription 3 (STAT-3) were activated much earlier and to a greater extent in VDUP1 KO mice after PH. A single injection of TNF-alpha or IL-6 caused rapid activation of JNK and STAT-3 expression in both mice, but the responses were stronger and more sustained in VDUP1 KO mice. In conclusion, our findings provide evidence that VDUP1 plays a role in initiation of liver regeneration.
Assuntos
Animais , Masculino , Western Blotting , Proteínas de Transporte/genética , Proliferação de Células , Regulação da Expressão Gênica , Hepatectomia , Hepatócitos/citologia , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Fígado/fisiologia , Camundongos Knockout , NF-kappa B/genética , Reação em Cadeia da Polimerase , Regeneração , Fator de Transcrição STAT3/genética , Tiorredoxinas/genéticaRESUMO
No abstract available.
Assuntos
Crescimento Excessivo da Gengiva , Granuloma de Células Plasmáticas , Imuno-Histoquímica , Interleucina-6 , Fosfolipases , Plasmócitos , PlasmaRESUMO
BACKGROUND: Hemopoietic cells require the constant presence of growth factors for survival in vitro and in vivo. Caspases have been known as central executors of apoptotic cell death. We have, therefore, investigated the pathways that regulate caspase activity and apoptosis using the CD34+ cell line, TF-1 which requires GM-CSF for survival. METHODS: Apoptosis was measured by annexin V staining and mitochondrial membrane potential was measured by DiOC6 labelling. Intracellular pH was measured using pH sensitive fluorochrome, BCECF or SNARF-1, followed by flow cytometry analysis. Caspase activation was analyzed by PARP cleavage using anti-PARP antibody. RESULTS: Removal of GM-CSF induceed PARP cleavage, a hallmark of caspase activity, concomitant with pHi acidification and a drop in mitochondrial potential. Treatment with ZVAD, a competitive inhibitor of caspases, partially rescued cell death without affecting pHi acidification and the reduction of mitochondrial potential, suggesting that both these events act upstream of caspases. Overexpression of Bcl-2 prevented cell death induced by GM-CSF deprivation as well as pHi acidification and the reduction in mitochondrial membrane potential. In parental cells maintained with GM-CSF, EIPA, a competitive inhibitor of Na+/H+ antiporter induced apoptosis, accompanied by a drastic reduction in mitochondrial potential. In contrast, EIPA induced apoptosis in Bcl-2 transfectants without causing mitochondrial membrane depolarization. CONCLUSION: Taken together, our results suggest that the regulation of H fluxes, either through a mitochondrion- dependent or independent pathway, is central to caspase activation and apoptosis.
Assuntos
Humanos , Anexina A5 , Apoptose , Caspases , Morte Celular , Linhagem Celular , Citometria de Fluxo , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Concentração de Íons de Hidrogênio , Peptídeos e Proteínas de Sinalização Intercelular , Transporte de Íons , Potencial da Membrana Mitocondrial , Membranas Mitocondriais , PaisRESUMO
We report two cases of gingival plasma cell granuloma in a 34-yr-old and 40-yr-old two male renal transplant recipients with cyclosporine A (CsA)-induced gingival overgrowth (GO). Histologically, these lesions were composed of mature plasma cells, showing polyclonality for both lambda and kappa light chains and fibrovascular connective tissue stroma. In addition to the fact that CsA-induced plasma cell granuloma is rare, the salient features of our cases were the secretion of interleukin-6 and overexpression of phospholipase C-gamma1 of the tumor cells, which may explain the mechanisms of CsA- induced GO.
Assuntos
Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ciclosporina/efeitos adversos , Doenças da Gengiva/induzido quimicamente , Granuloma de Células Plasmáticas/induzido quimicamente , Imuno-Histoquímica , Imunossupressores/efeitos adversos , Interleucina-6/metabolismo , Transplante de Rim , Fosfolipase C gama , Fosfolipases Tipo C/metabolismoRESUMO
BACKGROUND: Bone marrow stromal cells (BMSCs) express many cell surface molecules, which regulate the proliferation and differentiation of immune cells within the bone marrow. METHODS: To identify cell surface molecules, which can regulate cell proliferation through cell interaction, monoclonal antibodies (MoAbs) against BMSCs were produced. Among them, 1H8 MoAb, which recognized distinctly an 80 kDa protein, abolished myeloma cell proliferation that was induced by co-culturing with BMSCs. RESULTS: IL-6 gene expression was increased when myeloma or stromal cells were treated with 1H8 MoAb. In addition, the expression of IL-6 receptor and CD40 was up-regulated by 1H8 treatment, suggesting that the molecule recognized by 1H8 MoAb is involved in cell proliferation by modulating the expression of cell growth-related genes. Myeloma cells contain high levels of reactive oxygen species (ROS), which are related to gene expression and tumorigenesis. Treatment with 1H8 decreased the intracellular ROS level and increased PAG antioxidant gene concomitantly. Finally, 1H8 induced the tyrosine phosphorylation of several proteins in U266. CONCLUSION: Taken together, 1H8 MoAb recognized the cell surface molecule and triggered the intracellular signals, which led to modulate gene expression and cell proliferation.
Assuntos
Humanos , Anticorpos Monoclonais , Medula Óssea , Carcinogênese , Comunicação Celular , Proliferação de Células , Expressão Gênica , Interleucina-6 , Células-Tronco Mesenquimais , Fosforilação , Espécies Reativas de Oxigênio , Receptores de Interleucina-6 , Células Estromais , TirosinaRESUMO
No abstract available.
Assuntos
Linhagem Celular , Proliferação de Células , Citocinas , Leucemia Eritroblástica AgudaRESUMO
Highly specific and sensitive immunoassay method for soluble human recombinant interleukin-6 (hu rlL-6) was established by two different immunization methods. One is conventional method by Freund's adjuvant method and the other is special method which is directly injected to mouse spleen. Among seven established monoclonal antibodies (mAbs), two typical monoclonal antibodies, designated YB3 (IgG1) and NY2 (IgM), were further characterized. These mAbs highly bound to IL-6, however did not show cross reactivity with IL-1B and IL-2. As the results of ELISA inhibition assay and western blotting method, it was further identified that YB3 and NY2 had high binding specificity with IL-6. And the limiting detection amount of rlL-6 for YB3 was 5 ng/ml and for NY2 was 0.5 ng/ml. Furthermore, N-glycosylated human rlL-6 was also bound to YB3 on ELISA. On the other hand YB-3 furtherly recognized N-glycosylated human rlL-6 by sandwich ELISA method. These mAbs may be of use to diagnose the gynecopathy which contains abortion and preterm labor.
Assuntos
Animais , Feminino , Humanos , Camundongos , Gravidez , Anticorpos Monoclonais , Western Blotting , Ensaio de Imunoadsorção Enzimática , Adjuvante de Freund , Mãos , Imunização , Imunoensaio , Interleucina-2 , Interleucina-6 , Trabalho de Parto Prematuro , Sensibilidade e Especificidade , BaçoRESUMO
The pleckstrin homology (PH) domain is a protein module of approximately 100 amino acids, that has been found in signaling molecules, including serinelthreonine kinase, GTPase-activating protein, phospholipase, and some cytoskeletal proteins. Although the specific function of PH domain has not been defined yet, it is believed that this domain is involved in the regulation of signal transduction pathway. The expression plasmids of human PLCg PH domains were constructed to see the roles of them in IL-6 signal transduction. When these expression plasmids are transfected into B9 cells, only N-terminal of PH domain inhibited IL-6-induced B9 cell proliferation. These results suggest that N-terminal of PH domain is critical for IL-6 signal transduction in B9 cells. To search the binding proteins associated PH domains of PLCy1 in B9 cells, Glutathione S-trnaferase (GST) fusion proteins containg PH domains were expressed in E. coli. Then, IL-6-dependent B9 cells were treated with 10 unit/ml IL-6 and the cell lysates were immunoprecipited with GST-PH doman fusion proteins. In vitro kinase assay of immune complex demonstrated that p38 (38 KDa) protein was coprecipitated with NC fusion protein, but IL-6 had no additional effect on it. When S-methaionine labelled cell lysates were used for immunoprecipitation, the same result was observed, conforming the association of p38 with NC motive of PH domain.
Assuntos
Humanos , Aminoácidos , Complexo Antígeno-Anticorpo , Proteínas de Transporte , Proliferação de Células , Proteínas do Citoesqueleto , Glutationa , Proteínas Ativadoras de GTPase , Concentração de Íons de Hidrogênio , Imunoprecipitação , Interleucina-6 , Fosfolipases , Fosfotransferases , Plasmídeos , Transdução de SinaisRESUMO
Peripheral T cell lymphoma encompasses lymphomas with a variety of histologic appearances and clinical patterns. Recently, it has been suggested that almost all of the histologic features described under the name of polymorphic reticulosis(PR), lethal midline granuloma, and midline malignant reticulosis can be included in those generally described for malignant lymphomas of peripheral T cell origin(PTCL). There have been few studies of pathogenesis or tissue damage mechanism in PR patients. The need for a precise mechanism for tissue damage has important therapeutic implications. Using immunohistochemical methods with polyclonal anti IL-6 antibody, the authors describe 5 cases of PR with clinically and pathologically typical PR demonstrating a high expression of IL-6. According to classification, 2 cases of grade 1 PR showed the highest expressions, and 2 cases of grade 2 PR with atypical lymphoid cells showed moderate activity, but one case progressed into frank lymphoma(grade 3) and lost IL-6 expression. This strongly implies that some cases of PR have a different mechanism of tissue damage from frank PTCL, despite the one disease spectrum. Further studies on more cases may help clarify the pathogenesis.
Assuntos
Adulto , Feminino , Humanos , Masculino , Estudo Comparativo , Imuno-Histoquímica , Interleucina-6/fisiologia , Linfoma de Células T/metabolismo , Microscopia , Pessoa de Meia-Idade , Fenótipo , Polimorfismo Genético , Doenças Linfáticas/genéticaRESUMO
No abstract available.