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1.
Pharmaceuticals (Basel) ; 17(2)2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38399475

RESUMEN

Although a lot of effort has been put into creating drugs and combination therapies against chronic hepatitis, no effective treatment has been established. Type-I interferon is a promising therapeutic for chronic hepatitis due to its excellent anti-inflammatory effects through interferon receptors on hepatic macrophages. To develop a type-I IFN equipped with the ability to target hepatic macrophages through the macrophage mannose receptor, the present study designed a mouse type-I interferon-mannosylated albumin fusion protein using site-specific mutagenesis and albumin fusion technology. This fusion protein exhibited the induction of anti-inflammatory molecules, such as IL-10, IL-1Ra, and PD-1, in RAW264.7 cells, or hepatoprotective effects on carbon tetrachloride-induced chronic hepatitis mice. As expected, such biological and hepatoprotective actions were significantly superior to those of human fusion proteins. Furthermore, the repeated administration of mouse fusion protein to carbon tetrachloride-induced chronic hepatitis mice clearly suppressed the area of liver fibrosis and hepatic hydroxyproline contents, not only with a reduction in the levels of inflammatory cytokine (TNF-α) and fibrosis-related genes (TGF-ß, Fibronectin, Snail, and Collagen 1α2), but also with a shift in the hepatic macrophage phenotype from inflammatory to anti-inflammatory. Therefore, type-I interferon-mannosylated albumin fusion protein has the potential as a new therapeutic agent for chronic hepatitis.

2.
Int J Mol Sci ; 23(13)2022 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-35806419

RESUMEN

Nanoparticles (NPs) enhance soybean growth; however, their precise mechanism is not clearly understood. To develop a more effective method using NPs for the enhancement of soybean growth, fiber crosslinked with zinc oxide (ZnO) NPs was prepared. The solution of ZnO NPs with 200 nm promoted soybean growth at the concentration of 10 ppm, while fibers crosslinked with ZnO NPs promoted growth at a 1 ppm concentration. Soybeans grown on fiber cross-linked with ZnO NPs had higher Zn content in their roots than those grown in ZnO NPs solution. To study the positive mechanism of fiber crosslinked with ZnO NPs on soybean growth, a proteomic technique was used. Proteins categorized in photosynthesis and secondary metabolism accumulated more in soybeans grown on fiber crosslinked with ZnO NPs than in those grown in ZnO NPs solution. Furthermore, significantly accumulated proteins, which were NADPH oxidoreductase and tubulins, were confirmed using immunoblot analysis. The abundance of NADPH oxidoreductase increased in soybean by ZnO NPs application. These results suggest that fiber crosslinked with ZnO NPs enhances soybean growth through the increase of photosynthesis and secondary metabolism. Additionally, the accumulation of NADPH oxidoreductase might relate to the effect of auxin with fiber crosslinked with ZnO NPs on soybean growth.


Asunto(s)
Fabaceae , Nanopartículas , Óxido de Zinc , Fabaceae/metabolismo , NADP/metabolismo , Oxidorreductasas/metabolismo , Proteómica , Plantones/metabolismo , Glycine max/metabolismo , Zinc/metabolismo , Óxido de Zinc/química
4.
Cancer Res ; 81(17): 4545-4559, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-34210751

RESUMEN

Blood levels of acute-phase protein α1-acid glycoprotein (AGP, orosmucoid) increase in patients with cancer. Although AGP is produced from hepatocytes following stimulation by immune cell-derived cytokines under conditions of inflammation and tumorigenesis, the functions of AGP in tumorigenesis and tumor progression remain unknown. In the present study, we revealed that AGP contributes directly to tumor development by induction of programmed death ligand 1 (PD-L1) expression and IL6 production in macrophages. Stimulation of AGP induced PD-L1 expression in both human monocyte-derived macrophages through STAT1 activation, whereas AGP had no direct effect on PD-L1 expression in tumor cells. AGP also induced IL6 production from macrophages, which stimulated proliferation in tumor cells by IL6R-mediated activation of STAT3. Furthermore, administration of AGP to AGP KO mice phenocopied effects of tumor-associated macrophages (TAM) on tumor progression. AGP decreased IFNγ secretion from T cells and enhanced STAT3 activation in subcutaneous tumor tissues. In addition, AGP regulated PD-L1 expression and IL6 production in macrophages by binding with CD14, a coreceptor for Toll-like receptor 4 (TLR4), and inducing TLR4 signaling. These results provide the first evidence that AGP is directly involved in tumorigenesis by interacting with TAMs and that AGP might be a target molecule for anticancer therapy. SIGNIFICANCE: AGP-mediated suppression of antitumor immunity contributes to tumor progression by inducing PD-L1 expression and IL6 production in TAMs.


Asunto(s)
Antígeno B7-H1/metabolismo , Macrófagos/metabolismo , Orosomucoide/metabolismo , Macrófagos Asociados a Tumores/metabolismo , Animales , Carcinogénesis , Proliferación Celular , Progresión de la Enfermedad , Elementos de Facilitación Genéticos , Hepatocitos/metabolismo , Terapia de Inmunosupresión , Interferón gamma/metabolismo , Macrófagos/citología , Proteínas de la Membrana , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Ratones Noqueados , Monocitos/citología , Orosomucoide/genética , Transducción de Señal , Receptor Toll-Like 4/metabolismo
5.
Toxicol Pathol ; 49(1): 5-109, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33393871

RESUMEN

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions) Project (www.toxpath.org/inhand.asp) is a joint initiative of the societies of toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP), and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying lesions observed in most tissues and organs from the dog used in nonclinical safety studies. Some of the lesions are illustrated by color photomicrographs. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous lesions, lesions induced by exposure to test materials, and relevant infectious and parasitic lesions. A widely accepted and utilized international harmonization of nomenclature for lesions in laboratory animals will provide a common language among regulatory and scientific research organizations in different countries and increase and enrich international exchanges of information among toxicologists and pathologists.


Asunto(s)
Animales de Laboratorio , Animales , Bases de Datos Factuales , Perros , Europa (Continente) , Japón
6.
Intern Med ; 59(18): 2245-2248, 2020 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-32522918

RESUMEN

Recently, immune checkpoint inhibitors (iCIs) have been used to treat cancers. Once some of the iCIs for the treatment of hepatocellular carcinoma (HCC) are certified in clinical trials, they are likely be administered to HCC patients with hepatitis C virus (HCV). However, the immunopathogenesis of HCV after the administration of iCIs has not been clarified. We experienced a lung cancer patient with HCV infection treated by nivolumab, programmed cell death 1 (PD-1) antibody. HCV-RNA gradually decreased after the start of nivolumab treatment. However, no increase in transaminase was observed during the decline of HCV-RNA. It was thought that HCV-specific cytotoxic T lymphocytes (CTLs) were activated by iCIs.


Asunto(s)
Hepacivirus/efectos de los fármacos , Inhibidores de Puntos de Control Inmunológico/farmacología , Neoplasias Pulmonares/tratamiento farmacológico , Nivolumab/farmacología , ARN Viral/efectos de los fármacos , Anciano , Hepatitis C/complicaciones , Humanos , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Neoplasias Pulmonares/complicaciones , Masculino , Nivolumab/uso terapéutico , Transaminasas/sangre
7.
Gan To Kagaku Ryoho ; 47(1): 1-5, 2020 Jan.
Artículo en Japonés | MEDLINE | ID: mdl-32381852

RESUMEN

Recently, the choices of treatments for hepatocellular carcinoma(HCC)were increasing since the several molecular targeting agents(MTA)were approved for treatment of advanced HCC patients. On the other hand, the transarterial chemoembolization( TACE)and hepatic artery infusion chemotherapy(HAIC)have been improved by various kinds of methods. The liver resection, radiofrequency ablation(RFA)and microwave coagulation(MWA)might achieve complete cure. However, the treatment indication of liver resection, RFA and MWA should be limited. Therefore, multidisciplinary treatment including HAIC, TACE, MTA, RFA, MWA, and liver resection should be considered to control HCC.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Quimioembolización Terapéutica , Arteria Hepática , Humanos , Infusiones Intraarteriales
8.
Sci Rep ; 10(1): 941, 2020 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-31969598

RESUMEN

Mechanisms of hepatitis B virus (HBV) reactivation after hepatitis C virus (HCV) elimination by direct-acting antiviral (DAA) treatment in HBV/HCV-co-infected patients remain unclear. We examined RIG-I-like helicase (RLH) pathway activation by HBV mono-infection, HCV mono-infection or HBV/HCV co-infection and interference between HBV and HCV in primary human hepatocytes. Interference between HBV and HCV and HBV reactivation after DAA treatment in humanized-liver mice were assessed. HCV infection activated RLH pathway, as evidenced by RIG-I, ISG15 and ISG56 expression induction; HBV caused only RIG-I induction in vitro. RLH activation was also found in HBV/HCV-co-infected cells, and HBV replication were suppressed in HBV/HCV-co-infected than in HBV-mono-infected cells. siRNA-mediated double knockdown of ISG15 and ISG56 increased HBV replication in HBV/HCV-co-infected cells. HCV infection activated RLH pathway and suppressed HBV replication in humanized-liver mice. Subsequent elimination of HCV by DAA administration downregulated RLH pathway and upregulated HBV replication in mice. RLH pathway was activated in livers of chronic hepatitis C patients compared to those of chronic hepatitis B or non-B, non-C patients. The RLH pathway activation was downregulated by HCV elimination. In conclusion, HCV infection activated RLH pathway and suppressed HBV replication in human hepatocytes. HCV elimination upregulated HBV replication, probably through RLH pathway downregulation.


Asunto(s)
Coinfección/virología , Proteína 58 DEAD Box/metabolismo , ARN Helicasas DEAD-box/metabolismo , Virus de la Hepatitis B/fisiología , Hepatitis C Crónica/virología , Hepatitis C/virología , Hepatocitos/virología , Transducción de Señal , Replicación Viral , Animales , Células Cultivadas , Regulación hacia Abajo , Humanos , Hígado/metabolismo , Hígado/virología , Ratones , Receptores Inmunológicos
9.
Sci Rep ; 9(1): 13393, 2019 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-31527804

RESUMEN

It has been reported that various kinds of miRNAs could affect the pathogenesis of hepatitis C virus infection. Recently, our group reported that deep-sequencing analysis was useful to detect disease-specific miRNAs. The aim of this study is to identify the HCV-specific miRNAs that could contribute to the immunopathogenesis of HCV by using clinical samples and in vitro analysis. Five miRNAs (hsa-miR181a-2-3p, hsa-miR-374a-3p, hsa-miR374a-5p, hsa-miR-204-5p and hsa-miR146b-5p) were shown to be significantly downregulated in CH-C by deep sequence analysis. The average ratio (PBMCs miRNAs/serum miRNAs) of hsa-miR146b-5p was highest among all the miRNAs. Moreover, serum hsa-miR146b-5p was significantly down-regulated in CH-C patients in comparison to CH-B patients and healthy subjects. The expression of hsa-miR146b-5p in CD3+ T cells and CD14+ monocytes of CH-C patients was significantly lower than that of the other groups. The hsa-miR146b-5p expression in CD14+ monocytes of SVR patients treated with Peg-IFN/RBV was significantly higher than in those of non-SVR patients treated with Peg IFN/RBV. However, the hsa-miR146b-5p expression in CD14+ monocytes of SVR patients treated with DCV and ASV was comparable to that in monocytes of non-SVR patients treated with DCV and ASV. Moreover, the expression levels of hsa-miR146b-5p in CD14+ monocytes were significantly increased after achieving SVR and 1(OH)Vitamin D3 treatment. Further, the expression of HCV-Core could suppress miR146b-5p expression in immune cells and affect the expression of various kinds of cytokines by affecting the NF-κB signaling. In conclusion, the reduction of miR146b-5p in monocytes and T cells could contribute to the immunopathogenesis of hepatitis C virus infection.


Asunto(s)
Hepacivirus/inmunología , Hepatitis C/inmunología , MicroARNs/genética , Monocitos/inmunología , Linfocitos T/inmunología , Estudios de Casos y Controles , Perfilación de la Expresión Génica , Hepatitis C/genética , Hepatitis C/patología , Hepatitis C/virología , Humanos , Monocitos/metabolismo , Monocitos/patología , Monocitos/virología , Linfocitos T/metabolismo , Linfocitos T/patología , Linfocitos T/virología
10.
Hepatol Res ; 49(3): 355-359, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30375711

RESUMEN

AIMS: Previously, our group reported that lymphotropic hepatitis C virus (HCV) could induce various kinds of immune dysfunctions. The immune dysfunctions could cause vascular disease by inducing cryoglobulinemia. It has been reported that ischemic heart diseases might be caused by HCV. However, the infectious rate of HCV in patients with ischemic heart disease has not been clarified in northern Japan. Therefore, we tried to determine the rate of HCV infectivity in patients with ischemic heart disease. METHODS: The target patients of this study were automatically selected using an electronic medical record system to exclude selection bias. The system identified 16 484 patients with ischemic heart disease who were included in this study. In addition, 12 902 subjects who had received medical checkups were included as the control group. RESULTS: The positive rate of HCV antibody among the patients with ischemic disease in our hospital was 2.58%, which was significantly higher (P < 0.01) than in the medical checkup patients (0.84%). The positive rate of HCV antibody in the patients with ischemic heart disease in each age group was significantly higher than in the corresponding age groups of the medical checkup patients. The rate of chronic kidney disease in HCV antibody-positive patients treated by percutaneous coronary intervention (PCI) was significantly higher than in HCV antibody-negative patients treated by PCI (P = 0.02). CONCLUSIONS: Hepatitis C virus infection might be associated with the pathogenesis of ischemic heart disease and HCV antibody positivity might be a risk factor for ischemic heart disease in northern Japan.

11.
Intern Med ; 57(21): 3157-3162, 2018 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-29877257

RESUMEN

Pembrolizumab, a humanized monoclonal IgG4 antibody directed against programmed death-1, is an immune checkpoint inhibitor that has been introduced for the treatment of non-small-cell lung cancer. However, immune checkpoint inhibitors may cause severe immune-related adverse events. We herein present a case of lung cancer with complete atrioventricular block associated with acute myocarditis, which developed 16 days after the administration of pembrolizumab. The clinical course of this case suggested a strong need for close cardiac monitoring when pembrolizumab is administered on an outpatient basis.


Asunto(s)
Anticuerpos Monoclonales Humanizados/efectos adversos , Antineoplásicos Inmunológicos/efectos adversos , Bloqueo Atrioventricular/inducido químicamente , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Miocarditis/inducido químicamente , Enfermedad Aguda , Anciano , Humanos , Masculino , Monitoreo Fisiológico , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores
12.
J Toxicol Pathol ; 29(4): 265-268, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27821912

RESUMEN

Mott cells are a variant form of plasma cells in humans and laboratory animals. This report describes the morphological characteristics of Mott cells observed in a 33-week-old female CB6F1-Tg rasH2 mouse. Microscopically, a large number of round cells with abundant eosinophilic globules, which were variable in size, were observed in the spleen and were densely distributed in the red pulp adjacent to the marginal zone. A few similar cells were present in the submandibular lymph node and bone marrow. Neither systemic nor local chronic inflammatory changes were seen in this animal. These cells were positive for mouse immunoglobulins. Ultrastructurally, the dilated rough endoplasmic reticulum had a homogenous substances with an intermediate electron density. On the basis of the above findings, these cells were identified as Mott cells. The present lesion is thought to be a spontaneous lesion, an unusual appearance of Mott cells without any associated pathological conditions.

13.
Cell Biol Int ; 39(11): 1288-98, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26095163

RESUMEN

The precise localization and biological characteristics of the adipose progenitor cells are still a focus of debate. In this study, the localization of the adipose progenitor cells was determined using an organotypic culture system of adipose tissue slices. The tissue slices of subcutaneous white adipose tissue from rats were placed on a porous membrane and cultured at the interface between air and the culture medium for up to 5 days with or without adipogenic stimulation. The structure of adipose tissue components was sufficiently preserved during the culture and, following adipogenic stimulation with insulin, dexamethasone, and 3-isobutyl-1-methylxanthine, numerous multilocular adipocytes appeared in the interstitium among the mature adipocytes. Histomorphological 3-D observation using confocal laser microscopy revealed the presence of small mesenchymal cells containing little or no fat residing in the perivascular region and on the mature adipocytes and differentiation from the pre-existing mesenchymal cells to multilocular adipocytes. Immunohistochemistry demonstrated that these cells were initially present within the fibronectin-positive extracellular matrix (ECM). The adipose differentiation of the mesenchymal cells was confirmed by the enhanced expression of C/EBP-ß suggesting adipose differentiation and the concurrent advent of CD105-expressing mesenchymal cells within the interstitium of the mature adipocytes. Based on the above, the mesenchymal cells embedded in the ECM around the mature adipocytes were confirmed to be responsible for adipogenesis because the transition of the mesenchymal cells to the stem state contributed to the increase in the number of adipocytes in rat adipose tissue.


Asunto(s)
Adipocitos/citología , Tejido Adiposo Blanco/citología , Células Madre/citología , Adipocitos/metabolismo , Tejido Adiposo Blanco/metabolismo , Animales , Técnicas de Cultivo de Célula/métodos , Diferenciación Celular/fisiología , Medios de Cultivo , Matriz Extracelular/metabolismo , Masculino , Células Madre Mesenquimatosas/citología , Microscopía Confocal/métodos , Ratas , Ratas Sprague-Dawley , Células Madre/metabolismo
14.
J Toxicol Pathol ; 26(3): 319-23, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24155566

RESUMEN

This report describes the morphological and immunohistochemical characteristics of an adrenocortical carcinoma with distant metastasis in a Sprague-Dawley rat. Macroscopically, a single large mass was observed in the adrenal gland, and multiple nodules were noted in the lung, liver and thyroid. Histologically, the adrenal tumor consisted of a solid growth of eosinophilic round cells with nuclear atypia. Vascular invasion was present, and multiple metastatic lesions were also observed in the lungs, liver, and mediastinal lymph nodes. Immunohistochemically, the nuclei of these tumor cells were positive for Steroidogenic Factor-1 (SF-1). In the thyroid, tumor cells histologically resembling adrenal cells were immunohistochemically negative for SF-1 but positive for calcitonin; thus the lesion was diagnosed as thyroid C-cell carcinoma. From these results, the present case was diagnosed as adrenocortical carcinoma with distant metastases. SF-1 could be a valuable marker for the differential diagnosis of adrenocortical tumors versus other endocrine tumors such as C-cell carcinoma.

15.
J Toxicol Pathol ; 26(2): 209-13, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23914064

RESUMEN

The protein expressions of steroidogenic factor l (SF-l) and pituitary-specific transcription factor 1 (Pit-1) were investigated immunohistochemically for 53 spontaneous pituitary adenomas of the pars distalis from male Crl:CD(SD) rats. Luteinizing hormone (LH)-positive/prolactin (PRL)-negative and LH-negative/PRL-positive adenomas showed that the expression of SF-1 and Pit-1 was exclusively related to the immunoreactivity of LH and PRL, respectively. All double-positive adenomas (positive for both LH and PRL) were positive for Pit-1 and were supposed to be derived from PRL cells, although some of them also showed SF-1 immunoreactivity. In addition, all null cell adenomas (negative for all anterior pituitary hormones) were positive for SF-1 and negative for Pit-1, indicating that they originated from the gonadotroph cell lineage. This is the first report focusing on the application of transcription factors for the classification of rat pituitary adenomas.

16.
Mol Cancer Res ; 11(9): 973-85, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23741060

RESUMEN

UNLABELLED: Activation of aerobic glycolysis in cancer cells is well known as the Warburg effect, although its relation to cell- cycle progression remains unknown. In this study, human colon cancer cells were labeled with a cell-cycle phase-dependent fluorescent marker Fucci to distinguish cells in G1-phase and those in S + G2/M phases. Fucci-labeled cells served as splenic xenograft transplants in super-immunodeficient NOG mice and exhibited multiple metastases in the livers, frozen sections of which were analyzed by semiquantitative microscopic imaging mass spectrometry. Results showed that cells in G1-phase exhibited higher concentrations of ATP, NADH, and UDP-N-acetylglucosamine than those in S and G2-M phases, suggesting accelerated glycolysis in G1-phase cells in vivo. Quantitative determination of metabolites in cells synchronized in S, G2-M, and G1 phases suggested that efflux of lactate was elevated significantly in G1-phase. By contrast, ATP production in G2-M was highly dependent on mitochondrial respiration, whereas cells in S-phase mostly exhibited an intermediary energy metabolism between G1 and G2-M phases. Isogenic cells carrying a p53-null mutation appeared more active in glycolysis throughout the cell cycle than wild-type cells. Thus, as the cell cycle progressed from G2-M to G1 phases, the dependency of energy production on glycolysis was increased while the mitochondrial energy production was reciprocally decreased. IMPLICATIONS: These results shed light on distinct features of the phase-specific phenotypes of metabolic systems in cancer cells.


Asunto(s)
Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Metabolismo Energético , Fase G1 , Glucólisis , Adenosina Trifosfato/metabolismo , Animales , Línea Celular , Fase G2 , Células HCT116 , Xenoinjertos , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/secundario , Ratones , Mitocondrias/metabolismo , Trasplante de Neoplasias , Fosforilación Oxidativa , Fase S
17.
J Clin Biochem Nutr ; 46(1): 36-42, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20104263

RESUMEN

Sustained virologic response with peg-interferon and ribavirin combination therapy for 48 weeks is still inadequate. Our study examined whether short-term administration of retinol clinically influences the anti-viral activity of interferon early during interferon and ribavirin combination therapy. The control group received 6 MIU of interferon alpha-2b every day for two weeks and then 3 times a week for 22 weeks intramuscularly plus 600 mg or 800 mg per day of ribavirin orally for 24 weeks. The retinol group, in addition to above treatment, received retinol 30,000 units per day orally for 3 weeks from one week before the start of interferon alpha-2b plus ribavirin combination therapy. The hepatitis C virus (HCV) RNA negativity rate at 1 week after the end of interferon alpha-2b and ribavirin combination therapy was 46.7% (28/60) for the retinol group and 31.7% (19/60) for the control group, which was significantly higher for the retinol group. The level of serum HCV RNA in the retinol group was significantly lower at 1 week after beginning treatment as compared to the control group (p<0.01). Furthermore, serum 2,5'AS protein at 1 week after beginning treatment was significantly higher in the retinol group (p = 0.0002). The results suggest that retinol supplement increases the antiviral effect of interferon alpha-2b plus ribavirin only during the administration of IFN alpha-2b, ribavirin and retinol in patients with chronic hepatitis C.

18.
Antioxid Redox Signal ; 13(2): 157-92, 2010 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-19939208

RESUMEN

The diverse physiological actions of the "biologic gases," O2, CO, NO, and H2S, have attracted much interest. Initially viewed as toxic substances, CO, NO, and H2S play important roles as signaling molecules. The multiplicity of gas actions and gas targets and the difficulty in measuring local gas concentrations obscures detailed mechanisms whereby gases exert their actions, and many questions remain unanswered. It is now readily apparent, however, that heme-based proteins play central roles in gas-generation/reception mechanisms and provide a point where multiple gases can interact. In this review, we consider a number of key issues related to "gas biology," including the effective tissue concentrations of these gases and the importance and significance of the physical proximity of gas-producing and gas-receptor/sensors. We also take an integrated approach to the interaction of gases by considering the physiological significance of CO, NO, and H2S on mitochondrial cytochrome c oxidase, a key target and central mediator of mitochondrial respiration. Additionally, we consider the effects of biologic gases on mitochondrial biogenesis and "suspended animation." By evaluating gas-mediated control functions from both in vitro and in vivo perspectives, we hope to elaborate on the complex multiple interactions of O2, NO, CO, and H2S.


Asunto(s)
Monóxido de Carbono/metabolismo , Sulfuro de Hidrógeno/metabolismo , Óxido Nítrico/metabolismo , Oxígeno/metabolismo , Transducción de Señal/fisiología , Animales , Enfermedades del Sistema Nervioso Central/metabolismo , Transporte de Electrón/fisiología , Hemo/química , Hemo Oxigenasa (Desciclizante)/química , Hemo Oxigenasa (Desciclizante)/metabolismo , Hemoproteínas/química , Hemoproteínas/metabolismo , Humanos , Mitocondrias/metabolismo , Modelos Moleculares , Estructura Molecular , Oxidación-Reducción , Distribución Tisular
19.
Cancer Cell ; 11(5): 407-20, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17482131

RESUMEN

Many cancer cells are characterized by increased glycolysis and decreased respiration, even under aerobic conditions. The molecular mechanisms underlying this metabolic reprogramming are unclear. Here we show that hypoxia-inducible factor 1 (HIF-1) negatively regulates mitochondrial biogenesis and O(2) consumption in renal carcinoma cells lacking the von Hippel-Lindau tumor suppressor (VHL). HIF-1 mediates these effects by inhibiting C-MYC activity via two mechanisms. First, HIF-1 binds to and activates transcription of the MXI1 gene, which encodes a repressor of C-MYC transcriptional activity. Second, HIF-1 promotes MXI-1-independent, proteasome-dependent degradation of C-MYC. We demonstrate that transcription of the gene encoding the coactivator PGC-1beta is C-MYC dependent and that loss of PGC-1beta expression is a major factor contributing to reduced respiration in VHL-deficient renal carcinoma cells.


Asunto(s)
Carcinoma de Células Renales/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/fisiología , Neoplasias Renales/metabolismo , Mitocondrias/metabolismo , Proteínas Proto-Oncogénicas c-myc/antagonistas & inhibidores , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/patología , Proteínas Portadoras/genética , Línea Celular Tumoral , Humanos , Neoplasias Renales/genética , Neoplasias Renales/patología , Oxígeno/metabolismo , Proteínas Proto-Oncogénicas c-myc/fisiología , ARN Mensajero/genética , Proteínas de Unión al ARN , Transcripción Genética/fisiología
20.
Cell ; 129(1): 111-22, 2007 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-17418790

RESUMEN

O(2) is the ultimate electron acceptor for mitochondrial respiration, a process catalyzed by cytochrome c oxidase (COX). In yeast, COX subunit composition is regulated by COX5a and COX5b gene transcription in response to high and low O(2), respectively. Here we demonstrate that in mammalian cells, expression of the COX4-1 and COX4-2 isoforms is O(2) regulated. Under conditions of reduced O(2) availability, hypoxia-inducible factor 1 (HIF-1) reciprocally regulates COX4 subunit expression by activating transcription of the genes encoding COX4-2 and LON, a mitochondrial protease that is required for COX4-1 degradation. The effects of manipulating COX4 subunit expression on COX activity, ATP production, O(2) consumption, and reactive oxygen species generation indicate that the COX4 subunit switch is a homeostatic response that optimizes the efficiency of respiration at different O(2) concentrations. Thus, mammalian cells respond to hypoxia by altering COX subunit composition, as previously observed in yeast, but by a completely different molecular mechanism.


Asunto(s)
Hipoxia de la Célula , Respiración de la Célula , Complejo IV de Transporte de Electrones/metabolismo , Regulación Enzimológica de la Expresión Génica , Factor 1 Inducible por Hipoxia/metabolismo , Aerobiosis , Animales , Línea Celular , Línea Celular Tumoral , Células Cultivadas , Complejo IV de Transporte de Electrones/química , Complejo IV de Transporte de Electrones/genética , Embrión de Mamíferos/citología , Fibroblastos , Células HeLa , Humanos , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Ratones , Miocitos del Músculo Liso , Proteasa La/genética , Proteasa La/metabolismo , Subunidades de Proteína/química , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Arteria Pulmonar/citología , ARN Mensajero , Elementos de Respuesta
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