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1.
PLoS Biol ; 18(9): e3000813, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32991574

RESUMEN

Short-chain fatty acids (SCFAs) produced by gastrointestinal microbiota regulate immune responses, but host molecular mechanisms remain unknown. Unbiased screening using SCFA-conjugated affinity nanobeads identified apoptosis-associated speck-like protein (ASC), an adaptor protein of inflammasome complex, as a noncanonical SCFA receptor besides GPRs. SCFAs promoted inflammasome activation in macrophages by binding to its ASC PYRIN domain. Activated inflammasome suppressed survival of Salmonella enterica serovar Typhimurium (S. Typhimurium) in macrophages by pyroptosis and facilitated neutrophil recruitment to promote bacterial elimination and thus inhibit systemic dissemination in the host. Administration of SCFAs or dietary fibers, which are fermented to SCFAs by gut bacteria, significantly prolonged the survival of S. Typhimurium-infected mice through ASC-mediated inflammasome activation. SCFAs penetrated into the inflammatory region of the infected gut mucosa to protect against infection. This study provided evidence that SCFAs suppress Salmonella infection via inflammasome activation, shedding new light on the therapeutic activity of dietary fiber.


Asunto(s)
Proteínas Adaptadoras de Señalización CARD/metabolismo , Ácidos Grasos Volátiles/metabolismo , Inflamasomas/inmunología , Inflamasomas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Infecciones por Salmonella/prevención & control , Animales , Proteínas Adaptadoras de Señalización CARD/genética , Femenino , Microbioma Gastrointestinal/inmunología , Células HEK293 , Humanos , Inmunidad Innata/fisiología , Activación de Macrófagos/genética , Activación de Macrófagos/inmunología , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Unión Proteica , Receptores Acoplados a Proteínas G/genética , Infecciones por Salmonella/genética , Infecciones por Salmonella/inmunología , Infecciones por Salmonella/metabolismo , Salmonella typhimurium/inmunología , Células U937
2.
J Bone Miner Metab ; 41(4): 470-480, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37036533

RESUMEN

INTRODUCTION: The conditional manipulation of genes using the Cre recombinase-locus of crossover in P1 (Cre/loxP) system is an important tool for revealing gene functions and cell lineages in vivo. The outcome of this method is dependent on the performance of Cre-driver mouse strains. In most cases, Cre knock-in mice show better specificity than randomly inserted Cre transgenic mice. However, following knock-in, the expression of the original gene replaced by Cre is lost. MATERIALS AND METHODS: We generated a new differentiated osteoblast- and osteocyte-specific Cre knock-in mouse line that carries the viral T2A sequence encoding a 2A self-cleaving peptide at the end of the coding region of the dentin matrix protein 1 (Dmp1) gene accompanied by the Cre gene. RESULTS: We confirmed that Dmp1-T2A-Cre mice showed high Cre expression in osteoblasts, osteocytes, odontoblasts, and periodontal ligament cells and that the 2A self-cleaving peptide efficiently produced both Dmp1 and Cre proteins. Furthermore, unlike the Dmp1 knockout mice, homozygous Dmp1-T2A-Cre mice showed no skeletal abnormalities. Analysis using the Cre reporter strain confirmed differentiated osteoblast- and osteocyte-specific Cre-mediated recombination in the skeleton. Furthermore, recombination was also detected in some nuclei of skeletal muscle cells, spermatocytes, and intestinal cells. CONCLUSION: 2A-Cre functions effectively in vivo, and Dmp1-T2A-Cre knock-in mice are a useful tool for studying the functioning of various genes in hard tissues.


Asunto(s)
Integrasas , Péptidos , Masculino , Ratones , Animales , Integrasas/genética , Integrasas/metabolismo , Ratones Transgénicos , Péptidos/genética , Diferenciación Celular/genética , Ratones Noqueados , Proteínas de la Matriz Extracelular/genética
3.
J Proteome Res ; 19(6): 2516-2524, 2020 06 05.
Artículo en Inglés | MEDLINE | ID: mdl-32338917

RESUMEN

Extracellular vesicles such as exosomes are generally covered with an array of glycans, which are controlled by the host-cell glyco-synthetic machinery, similar to secreted and membrane glycoproteins. Several exosome subpopulations classified by their tetraspanin expression have been investigated in the context of diseases. However, a comparative analysis of their glycomics has never been attempted. Herein, we report a method for the comparative glycomic analysis of exosome subpopulations among pancreatic cancer cell lines. Glycomic profiles were obtained for extracellular vesicles, secreted glycoproteins, and membrane glycoproteins from eight cell lines. Statistical analyses revealed high populations of PHA-L-binding proteins in the vesicles. The surfaces of extracellular vesicles were labeled with Cy3 and captured by magnetic beads with antibodies against tetraspanins (CD9, CD63, and CD81). The coprecipitated vesicles were lysed and subjected to a lectin microarray analysis. A hierarchical clustering analysis using 19 glycomic profiles confirmed that most subpopulations, except CD81-positive exosomes, could be distinguished according to the host-cell species. Principal component analysis and subsequent lectin-affinity capturing of intact exosomes highlighted that CD81-positive exosomes preferentially expressed not PHA-L- but LEL-binding proteins on their surfaces. These data suggested that exosomal glycomics depended on the host-cell type and subpopulation.


Asunto(s)
Exosomas , Vesículas Extracelulares , Neoplasias Pancreáticas , Línea Celular , Glicómica , Humanos
4.
Hepatology ; 68(5): 1726-1740, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-29729190

RESUMEN

Drug resistance is a major problem in the treatment of liver cancer. Mammalian Target of Rapamycin 1 (mTORC1) inhibitors have been tested for the treatment of liver cancer based on hyperactive mTOR in this malignancy. However, their clinical trials showed poor outcome, most likely due to their ability to upregulate CD133 and promote chemoresistance. The CD133+ tumor-initiating stem cell-like cells (TICs) isolated from mouse and human liver tumors are chemoresistant, and identification of an approach to abrogate this resistance is desired. In search of a compound that rescinds resistance of TICs to mTORC1 inhibition and improves chemotherapy, we identified baicalein (BC), which selectively chemosensitizes TICs and the human hepatocellular carcinoma (HCC) cell line Huh7 cells but not mouse and human primary hepatocytes. Nanobead pull-down and mass-spectrometric analysis, biochemical binding assay, and three-dimensional computational modeling studies reveal BC's ability to competitively inhibit guanosine triphosphate binding of SAR1B guanosine triphosphatase, which is essential for autophagy. Indeed, BC suppresses autophagy induced by an mTORC1 inhibitor and synergizes cell death caused by mTORC1 inhibition in TIC and Huh7 spheroid formation and in the patient-derived xenograft model of HCC. The BC-induced chemosensitization is rescued by SAR1B expression and phenocopied by SAR1B knockdown in cancer cells treated with a mTORC1 inhibitor. Conclusion: These results identify SAR1B as a target in liver TICs and HCC cells resistant to mTORC1 inhibition.


Asunto(s)
Autofagia/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Flavanonas/farmacología , Neoplasias Hepáticas/tratamiento farmacológico , Células Madre Neoplásicas/efectos de los fármacos , Animales , Línea Celular Tumoral , Resistencia a Antineoplásicos/efectos de los fármacos , GTP Fosfohidrolasas/efectos de los fármacos , Humanos , Hígado/metabolismo , Hígado/patología , Diana Mecanicista del Complejo 1 de la Rapamicina/antagonistas & inhibidores , Ratones , Proteínas de Unión al GTP Monoméricas/metabolismo , Transducción de Señal/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto
5.
Anal Bioanal Chem ; 411(9): 1825-1837, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30627798

RESUMEN

Nanomaterials have extensive applications in the life sciences and in clinical diagnosis. We have developed magnetic nanoparticles with high dispersibility and extremely low nonspecific binding to biomolecules and have demonstrated their application in chemical biology (e.g., for the screening of drug receptor proteins). Recently, the excellent properties of nanobeads have made possible the development of novel rapid immunoassay systems and high-precision technologies for exosome detection. For immunoassays, we developed a technology to encapsulate a fluorescent substance in magnetic nanobeads. The fluorescent nanobeads allow the rapid detection of a specific antigen in solution or in tissue specimens. Exosomes, which are released into the blood, are expected to become markers for several diseases, including cancer, but techniques for measuring the absolute quantity of exosomes in biological fluids are lacking. By integrating magnetic nanobead technology with an optical disc system, we developed a novel method for precisely quantifying exosomes in human serum with high sensitivity and high linearity without requiring enrichment procedures. This review focuses on the properties of our magnetic nanobeads, the development of novel biosensors using these nanobeads, and their broad practical applications. Graphical abstract ᅟ.


Asunto(s)
Técnicas Biosensibles , Inmunoensayo/métodos , Magnetismo , Nanoestructuras , Exosomas , Fluorescencia , Límite de Detección , Nanopartículas
6.
Gastroenterology ; 152(6): 1477-1491, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28143772

RESUMEN

BACKGROUND & AIMS: Stearoyl-CoA desaturase (SCD) synthesizes monounsaturated fatty acids (MUFAs) and has been associated with the development of metabolic syndrome, tumorigenesis, and stem cell characteristics. We investigated whether and how SCD promotes liver fibrosis and tumor development in mice. METHODS: Rodent primary hepatic stellate cells (HSCs), mouse liver tumor-initiating stem cell-like cells (TICs), and human hepatocellular carcinoma (HCC) cell lines were exposed to Wnt signaling inhibitors and changes in gene expression patterns were analyzed. We assessed the functions of SCD by pharmacologic and conditional genetic manipulation in mice with hepatotoxic or cholestatic induction of liver fibrosis, orthotopic transplants of TICs, or liver tumors induced by administration of diethyl nitrosamine. We performed bioinformatic analyses of SCD expression in HCC vs nontumor liver samples collected from patients, and correlated levels with HCC stage and patient mortality. We performed nano-bead pull-down assays, liquid chromatography-mass spectrometry, computational modeling, and ribonucleoprotein immunoprecipitation analyses to identify MUFA-interacting proteins. We examined the effects of SCD inhibition on Wnt signaling, including the expression and stability of low-density lipoprotein-receptor-related proteins 5 and 6 (LRP5 and LRP6), by immunoblot and quantitative polymerase chain reaction analyses. RESULTS: SCD was overexpressed in activated HSC and HCC cells from patients; levels of SCD messenger RNA (mRNA) correlated with HCC stage and patient survival time. In rodent HSCs and TICs, the Wnt effector ß-catenin increased sterol regulatory element binding protein 1-dependent transcription of Scd, and ß-catenin in return was stabilized by MUFAs generated by SCD. This loop required MUFA inhibition of binding of Ras-related nuclear protein 1 (Ran1) to transportin 1 and reduced nuclear import of elav-like protein 1 (HuR), increasing cytosolic levels of HuR and HuR-mediated stabilization of mRNAs encoding LRP5 and LRP6. Genetic disruption of Scd and pharmacologic inhibitors of SCD reduced HSC activation and TIC self-renewal and attenuated liver fibrosis and tumorigenesis in mice. Conditional disruption of Scd2 in activated HSCs prevented growth of tumors from TICs and reduced the formation of diethyl nitrosamine-induced liver tumors in mice. CONCLUSIONS: In rodent HSCs and TICs, we found SCD expression to be regulated by Wnt-ß-catenin signaling, and MUFAs produced by SCD provided a forward loop to amplify Wnt signaling via stabilization of Lrp5 and Lrp6 mRNAs, contributing to liver fibrosis and tumor growth. SCD expressed by HSCs promoted liver tumor development in mice. Components of the identified loop linking HSCs and TICs might be therapeutic targets for liver fibrosis and tumors.


Asunto(s)
Carcinoma Hepatocelular/metabolismo , Ácidos Grasos Monoinsaturados/metabolismo , Cirrosis Hepática/metabolismo , Neoplasias Hepáticas/metabolismo , Estearoil-CoA Desaturasa/genética , Estearoil-CoA Desaturasa/metabolismo , Vía de Señalización Wnt/genética , Animales , Carcinoma Hepatocelular/inducido químicamente , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Estudios de Casos y Controles , Línea Celular Tumoral , Colestasis/complicaciones , Dietilnitrosamina , Proteína 1 Similar a ELAV/metabolismo , Células Estrelladas Hepáticas , Humanos , Cirrosis Hepática/etiología , Cirrosis Hepática/patología , Neoplasias Hepáticas/inducido químicamente , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad/genética , Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad/metabolismo , Proteína-6 Relacionada a Receptor de Lipoproteína de Baja Densidad/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baja Densidad/metabolismo , Masculino , Ratones , Estadificación de Neoplasias , Trasplante de Neoplasias , Células Madre Neoplásicas , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Tasa de Supervivencia , Transcripción Genética , beta Catenina/metabolismo , beta Carioferinas/metabolismo , Proteína de Unión al GTP ran/metabolismo
7.
Clin Chem ; 64(10): 1463-1473, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30021922

RESUMEN

BACKGROUND: Although circulating exosomes in blood play crucial roles in cancer development and progression, difficulties in quantifying exosomes hamper their application for reliable clinical testing. By combining the properties of nanobeads with optical disc technology, we have developed a novel device named the ExoCounter to determine the exact number of exosomes in the sera of patients with various types of cancer. METHOD: In this system, individual exosomes were captured in the groove of an optical disc coated with antibodies against exosome surface antigens. The captured exosomes were labeled with antibody-conjugated magnetic nanobeads, and the number of the labeled exosomes was counted with an optical disc drive. RESULTS: We showed that the ExoCounter could detect specific exosomes derived from cells or human serum without any enrichment procedures. The detection sensitivity and linearity with this system were higher than those with conventional detection methods such as ELISA or flow cytometry. In addition to the ubiquitous exosome markers CD9 and CD63, the cancer-related antigens CD147, carcinoembryonic antigen, and human epidermal growth factor receptor 2 (HER2) were also used to quantify cancer cell line-derived exosomes. Furthermore, analyses of a cross-sectional cohort of sera samples revealed that HER2-positive exosomes were significantly increased in patients with breast cancer or ovarian cancer compared with healthy individuals and those with noncancer diseases. CONCLUSIONS: The ExoCounter system exhibits high performance in the direct detection of exosomes in cell culture and human sera. This method may enable reliable analysis of liquid biopsies.


Asunto(s)
Antígenos de Neoplasias/sangre , Biomarcadores de Tumor/sangre , Exosomas , Dispositivos Laboratorio en un Chip , Procedimientos Analíticos en Microchip/métodos , Neoplasias/sangre , Células A549 , Exosomas/inmunología , Células HCT116 , Células HEK293 , Humanos , Sensibilidad y Especificidad , Coloración y Etiquetado , Tetraspanina 30/inmunología
8.
J Clin Biochem Nutr ; 63(1): 12-17, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30087538

RESUMEN

Progesterone receptor membrane associated component 1 is a multifunctional heme-binding protein that plays a role in several biological processes such as tumor progression, metabolic regulation, and viability control of nerve cells. Notably, progesterone receptor membrane associated component 1 is highly expressed in various types of cancer cells, and facilitates cancer proliferation and chemoresistance. Recently, progesterone receptor membrane associated component 1 structure has been explored by X-ray crystallographic analysis. Interestingly, whereas apo- progesterone receptor membrane associated component 1 exists as a monomer, the heme-bound progesterone receptor membrane associated component 1 converts into a stable dimer by forming a unique heme-heme stacking structure, leading to activation of epidermal growth factor receptor signaling and chemoresistance in cancer cells. Furthermore, the gas mediator carbon monoxide inhibits progesterone receptor membrane associated component 1-mediated activation in cancer cells by dissociating the heme-stacking dimer of progesterone receptor membrane associated component 1. The dynamic structural regulation of progesterone receptor membrane associated component 1 will provide new insights for understanding the mechanisms underlying its various functions.

9.
Pharmacol Res ; 117: 67-74, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-28007569

RESUMEN

A controversial relationship between sigma-2 and progesterone receptor membrane component 1 (PGRMC1) proteins, both representing promising targets for the therapy and diagnosis of tumors, exists since 2011, when the sigma-2 receptor was reported to be identical to PGRMC1. Because a misidentification of these proteins will lead to biased future research hampering the possible diagnostic and therapeutic exploitation of the two targets, there is the need to solve the debate on their identity. With this aim, we have herein investigated uptake and distribution of structurally different fluorescent sigma-2 receptor ligands by flow cytometry and confocal microscopy in MCF7 cells, where together with intrinsic sigma-2 receptors, PGRMC1 was constitutively present or alternatively silenced or overexpressed. HCT116 cells, with constitutive or silenced PGRMC1, were also studied. These experiments showed that the fluorescent sigma-2 ligands bind to their receptor irrespective of PGRMC1 expression. Furthermore, isothermal titration calorimetry was conducted to examine if DTG and PB28, two structurally distinct nanomolar affinity sigma-2 ligands, bind to purified PGRMC1 proteins that have recently been revealed to form both apo-monomeric and heme-mediated dimeric forms. While no binding to apo-PGRMC1 monomer was detected, a micromolar affinity to heme-mediated dimerized PGRMC1 was demonstrated in DTG but not in PB28. The current data provide evidence that sigma-2 receptor and PGRMC1 are not identical, paving the pathway for future unbiased research in which these two attractive targets are treated as different proteins while the identification of the true sigma-2 protein further needs to be pursued.


Asunto(s)
Proteínas de la Membrana/metabolismo , Receptores de Progesterona/metabolismo , Receptores sigma/metabolismo , Línea Celular Tumoral , Colorantes Fluorescentes/metabolismo , Células HCT116 , Humanos , Ligandos , Células MCF-7
10.
Microcirculation ; 23(3): 183-90, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26537442

RESUMEN

CO is a gaseous mediator generated by HO. Our previous studies revealed that CO generated from inducible HO-1 or from constitutive HO-2 modulates function of different heme proteins or enzymes through binding to their prosthetic ferrous heme to alter their structures, regulating biological function of cells and organs. Such CO-directed target macromolecules include sGC and CBS. In the liver, CO serves as a sinusoidal dilator through its action on sGC in hepatic stellate cells, while the same gas accounts for vasoconstrictor that inhibits H2S generated by CO-sensitive CBS in astrocytes. Since molecular O2 is a substrate for HO, the latter mechanism contributes to hypoxic vasodilation in neurovascular units. We have recently uncovered that stress-inducible CO in and around cancer cells suppresses CBS to result in decreased methylation of PFKFB3, the enzyme regulating PFK-1, leading to a shift of glucose biotransformation from glycolysis toward pentose phosphate pathway; such a metabolic remodeling causes chemoresistance through increasing NADPH and reduced glutathione under stress conditions for cancer cells. This article reviews the intriguing networks of CO-sensitive metabolic regulatory mechanisms in microcirculation and cancer.


Asunto(s)
Monóxido de Carbono/metabolismo , Cistationina betasintasa/metabolismo , Sulfuro de Hidrógeno/metabolismo , Neoplasias Hepáticas/metabolismo , Hígado/metabolismo , Proteínas de Neoplasias/metabolismo , Animales , Capilares/metabolismo , Capilares/patología , Hemo Oxigenasa (Desciclizante)/metabolismo , Hemo-Oxigenasa 1/metabolismo , Humanos , Macrófagos del Hígado/metabolismo , Macrófagos del Hígado/patología , Hígado/patología , Neoplasias Hepáticas/patología , Transmisión Sináptica
11.
Nitric Oxide ; 46: 102-13, 2015 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-25461272

RESUMEN

CD44 expressed in cancer cells was shown to stabilize cystine transporter (xCT) that uptakes cystine and excretes glutamate to supply cysteine as a substrate for reduced glutathione (GSH) for survival. While targeting CD44 serves as a potentially therapeutic stratagem to attack cancer growth and chemoresistance, the impact of CD44 targeting in cancer cells on metabolic systems of tumors and host tissues in vivo remains to be fully determined. This study aimed to reveal effects of CD44 silencing on alterations in energy metabolism and sulfur-containing metabolites in vitro and in vivo using capillary electrophoresis-mass spectrometry and quantitative imaging mass spectrometry (Q-IMS), respectively. In an experimental model of xenograft transplantation of human colon cancer HCT116 cells in superimmunodeficient NOG mice, snap-frozen liver tissues containing metastatic tumors were examined by Q-IMS. As reported previously, short hairpin CD44 RNA interference (shCD44) in cancer cells caused significant regression of tumor growth in the host liver. Under these circumstances, the CD44 knockdown suppressed polyamines, GSH and energy charges not only in metastatic tumors but also in the host liver. In culture, HCT116 cells treated with shCD44 decreased total amounts of methionine-pool metabolites including spermidine and spermine, and reactive cysteine persulfides, suggesting roles of these metabolites for cancer growth. Collectively, these results suggest that CD44 expressed in cancer accounts for a key regulator of metabolic interplay between tumor and the host tissue.


Asunto(s)
Cisteína/metabolismo , Receptores de Hialuranos/metabolismo , Metaboloma/fisiología , Neoplasias/metabolismo , Animales , Técnicas de Silenciamiento del Gen , Células HCT116 , Humanos , Receptores de Hialuranos/genética , Hígado/química , Hígado/metabolismo , Masculino , Espectrometría de Masas , Metaboloma/efectos de los fármacos , Metaboloma/genética , Metabolómica , Ratones , Neoplasias/genética , Interferencia de ARN , ARN Interferente Pequeño/farmacología , Trasplante Heterólogo
12.
Proc Natl Acad Sci U S A ; 109(4): 1293-8, 2012 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-22232681

RESUMEN

Enhancement of cerebral blood flow by hypoxia is critical for brain function, but signaling systems underlying its regulation have been unclear. We report a pathway mediating hypoxia-induced cerebral vasodilation in studies monitoring vascular disposition in cerebellar slices and in intact mouse brains using two-photon intravital laser scanning microscopy. In this cascade, hypoxia elicits cerebral vasodilation via the coordinate actions of H(2)S formed by cystathionine ß-synthase (CBS) and CO generated by heme oxygenase (HO)-2. Hypoxia diminishes CO generation by HO-2, an oxygen sensor. The constitutive CO physiologically inhibits CBS, and hypoxia leads to increased levels of H(2)S that mediate the vasodilation of precapillary arterioles. Mice with targeted deletion of HO-2 or CBS display impaired vascular responses to hypoxia. Thus, in intact adult brain cerebral cortex of HO-2-null mice, imaging mass spectrometry reveals an impaired ability to maintain ATP levels on hypoxia.


Asunto(s)
Monóxido de Carbono/metabolismo , Cerebro/irrigación sanguínea , Sulfuro de Hidrógeno/metabolismo , Hipoxia/fisiopatología , Microcirculación/fisiología , Flujo Sanguíneo Regional/fisiología , Vasodilatación/fisiología , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico , Adenosina Trifosfato/metabolismo , Análisis de Varianza , Animales , Western Blotting , Cistationina betasintasa/metabolismo , Cartilla de ADN/genética , Hemo Oxigenasa (Desciclizante)/genética , Hemo Oxigenasa (Desciclizante)/metabolismo , Inmunohistoquímica , Espectrometría de Masas , Ratones , Microscopía Confocal
13.
Proteomics ; 14(7-8): 810-9, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23818158

RESUMEN

Imaging MS combined with CE/MS serves as a method to provide semi-quantitative and spatial information of small molecular metabolites in tissue slices. However, not all metabolites including amino acids have fully been visualized, because of low-ionization efficiency in MALDI MS. This study aimed to acquire semi-quantitative spatial information for multiple amino acids in frozen tissue slices. As a derivatization reagent, p-N,N,N-trimethylammonioanilyl N'-hydroxysuccinimidyl carbamate iodide (TAHS) was applied to increase their ionization efficiency and detection sensitivity. Semi-quantitative MALDI-imaging MS allowed us to visualize and quantify free amino acid pools in human colon cancer xenografts using a model of liver metastases in super-immunodeficient NOD/scid/γ(null) mice (NOG mice). Because the m/z values of several TAHS-derivatized amino acids overlap with those of the 2,5-dihydroxybenzoic acid background and other endogenous compounds, we imaged them with tandem MS. The results indicated that regional contents of glutamate, glutamine, glycine, leucine/isoleucine/hydroxyproline, phenylalanine, and alanine were significantly elevated in metastatic tumors versus parenchyma of tumor-bearing livers. On-tissue TAHS derivatization thus serves as a useful method to detect alterations in many amino acid levels in vivo, thereby enabling understanding of the spatial alterations of these metabolites under varied disease conditions including cancer.


Asunto(s)
Aminoácidos/aislamiento & purificación , Neoplasias del Colon/patología , Imagen Molecular/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Aminoácidos/metabolismo , Animales , Neoplasias del Colon/metabolismo , Humanos , Ratones , Metástasis de la Neoplasia , Proteómica , Ensayos Antitumor por Modelo de Xenoinjerto
14.
Cancer Res ; 84(7): 1065-1083, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38383964

RESUMEN

Triple-negative breast cancer (TNBC) chemoresistance hampers the ability to effectively treat patients. Identification of mechanisms driving chemoresistance can lead to strategies to improve treatment. Here, we revealed that protein arginine methyltransferase-1 (PRMT1) simultaneously methylates D-3-phosphoglycerate dehydrogenase (PHGDH), a critical enzyme in serine synthesis, and the glycolytic enzymes PFKFB3 and PKM2 in TNBC cells. 13C metabolic flux analyses showed that PRMT1-dependent methylation of these three enzymes diverts glucose toward intermediates in the serine-synthesizing and serine/glycine cleavage pathways, thereby accelerating the production of methyl donors in TNBC cells. Mechanistically, PRMT1-dependent methylation of PHGDH at R54 or R20 activated its enzymatic activity by stabilizing 3-phosphoglycerate binding and suppressing polyubiquitination. PRMT1-mediated PHGDH methylation drove chemoresistance independently of glutathione synthesis. Rather, activation of the serine synthesis pathway supplied α-ketoglutarate and citrate to increase palmitate levels through activation of fatty acid synthase (FASN). Increased palmitate induced protein S-palmitoylation of PHGDH and FASN to further enhance fatty acid synthesis in a PRMT1-dependent manner. Loss of PRMT1 or pharmacologic inhibition of FASN or protein S-palmitoyltransferase reversed chemoresistance in TNBC. Furthermore, IHC coupled with imaging MS in clinical TNBC specimens substantiated that PRMT1-mediated methylation of PHGDH, PFKFB3, and PKM2 correlates with chemoresistance and that metabolites required for methylation and fatty acid synthesis are enriched in TNBC. Together, these results suggest that enhanced de novo fatty acid synthesis mediated by coordinated protein arginine methylation and protein S-palmitoylation is a therapeutic target for overcoming chemoresistance in TNBC. SIGNIFICANCE: PRMT1 promotes chemoresistance in TNBC by methylating metabolic enzymes PFKFB3, PKM2, and PHGDH to augment de novo fatty acid synthesis, indicating that targeting this axis is a potential treatment strategy.


Asunto(s)
Fosfoglicerato-Deshidrogenasa , Neoplasias de la Mama Triple Negativas , Humanos , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/genética , Resistencia a Antineoplásicos , Serina/metabolismo , Palmitatos , Ácidos Grasos , Línea Celular Tumoral , Proteína-Arginina N-Metiltransferasas/genética , Proteínas Represoras
15.
Mol Pharmacol ; 83(3): 613-20, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23229512

RESUMEN

Vitamin K2 (VK2, menaquinone) is known to have anticancer activity in vitro and in vivo. Although its effect is thought to be mediated, at least in part, by the induction of apoptosis, the underlying molecular mechanism remains elusive. Here, we identified Bcl-2 antagonist killer 1 (Bak) as a molecular target of VK2-induced apoptosis. VK2 directly interacts with Bak and induces mitochondrial-mediated apoptosis. Although Bak and Bcl-2-associated X protein (Bax), another member of the Bcl-2 family, are generally thought to be functionally redundant, only Bak is necessary and sufficient for VK2-induced cytochrome c (cyt c) release and cell death. Moreover, VK2-2,3 epoxide, an intracellular metabolite of VK2, was shown to covalently bind to the cysteine-166 residue of Bak. Several lines of evidence suggested that the covalent attachment of VK2 is critical for apoptosis induction. Thus this study reveals a specific role for Bak in mitochondria-mediated apoptosis. This study also provides insight into the anticancer effects of VK2 and suggests that Bak may be a potential target of cancer therapy.


Asunto(s)
Apoptosis/efectos de los fármacos , Vitamina K 2/metabolismo , Vitamina K 2/farmacología , Proteína Destructora del Antagonista Homólogo bcl-2/metabolismo , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Cisteína/metabolismo , Citocromos c/metabolismo , Células HL-60 , Células HeLa , Humanos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo
16.
Mol Pharmacol ; 83(5): 930-8, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23393163

RESUMEN

Vesnarinone is a synthetic quinolinone derivative used in the treatment of cardiac failure and cancer. It is also known to cause agranulocytosis as a side effect, which restricts its use, although the mechanism underlying agranulocytosis is not well understood. Here, we show that vesnarinone binds to valosin-containing protein (VCP), which interacts with polyubiquitinated proteins and is essential for the degradation of IκBα to activate nuclear factor (NF)κB. We show that vesnarinone impairs the degradation of IκBα, and that the impairment of the degradation of IκBα is the result of the inhibition of the interaction between VCP and the 26S proteasome by vesnarinone. These results suggest that vesnarinone suppresses NFκB activation by inhibiting the VCP-dependent degradation of polyubiquitinated IκBα, resulting in the suppression of tumor necrosis factor-α mRNA expression.


Asunto(s)
Adenosina Trifosfatasas/antagonistas & inhibidores , Proteínas de Ciclo Celular/antagonistas & inhibidores , Quinolinas/farmacología , ARN Mensajero/antagonistas & inhibidores , ARN Mensajero/biosíntesis , Factor de Necrosis Tumoral alfa/genética , Adenosina Trifosfatasas/genética , Adenosina Trifosfatasas/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Línea Celular , Células HEK293 , Humanos , Proteínas I-kappa B/genética , Proteínas I-kappa B/metabolismo , Inhibidor NF-kappaB alfa , FN-kappa B/genética , FN-kappa B/metabolismo , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Pirazinas , ARN Mensajero/genética , Factor de Necrosis Tumoral alfa/metabolismo , Proteína que Contiene Valosina
17.
JCI Insight ; 8(8)2023 04 24.
Artículo en Inglés | MEDLINE | ID: mdl-36917179

RESUMEN

Metabolic crosstalk from skeletal muscle to multiple organs is important for maintaining homeostasis, and its dysregulation can lead to various diseases. Chronic glucocorticoid administration often induces muscle atrophy and metabolic disorders such as diabetes and central obesity; however, the detailed underlying mechanism remains unclear. We previously reported that the deletion of glucocorticoid receptor (GR) in skeletal muscle increases muscle mass and reduces fat mass through muscle-liver-fat communication under physiological conditions. In this study, we show that muscle GR signaling plays a crucial role in accelerating obesity through the induction of hyperinsulinemia. Fat accumulation in liver and adipose tissue, muscle atrophy, hyperglycemia, and hyperinsulinemia induced by chronic corticosterone (CORT) treatment improved in muscle-specific GR-knockout (GR-mKO) mice. Such CORT-induced fat accumulation was alleviated by suppressing insulin production (streptozotocin injection), indicating that hyperinsulinemia enhanced by muscle GR signaling promotes obesity. Strikingly, glucose intolerance and obesity in ob/ob mice without CORT treatment were also improved in GR-mKO mice, indicating that muscle GR signaling contributes to obesity-related metabolic changes, regardless of systemic glucocorticoid levels. Thus, this study provides insight for the treatment of obesity and diabetes by targeting muscle GR signaling.


Asunto(s)
Diabetes Mellitus , Intolerancia a la Glucosa , Hiperinsulinismo , Ratones , Animales , Glucocorticoides/metabolismo , Intolerancia a la Glucosa/metabolismo , Obesidad/metabolismo , Hiperinsulinismo/metabolismo , Corticosterona/metabolismo , Receptores de Glucocorticoides/metabolismo , Diabetes Mellitus/metabolismo , Músculo Esquelético/metabolismo , Atrofia Muscular/metabolismo
18.
Antioxidants (Basel) ; 12(2)2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36829799

RESUMEN

Pathological examination of formalin-fixed paraffin-embedded (FFPE) needle-biopsied samples by certified pathologists represents the gold standard for differential diagnosis between ductal carcinoma in situ (DCIS) and invasive breast cancers (IBC), while information of marker metabolites in the samples is lost in the samples. Infrared laser-scanning large-area surface-enhanced Raman spectroscopy (SERS) equipped with gold-nanoparticle-based SERS substrate enables us to visualize metabolites in fresh-frozen needle-biopsied samples with spatial matching between SERS and HE staining images with pathological annotations. DCIS (n = 14) and IBC (n = 32) samples generated many different SERS peaks in finger-print regions of SERS spectra among pathologically annotated lesions including cancer cell nests and the surrounding stroma. The results showed that SERS peaks in IBC stroma exhibit significantly increased polysulfide that coincides with decreased hypotaurine as compared with DCIS, suggesting that alterations of these redox metabolites account for fingerprints of desmoplastic reactions to distinguish IBC from DCIS. Furthermore, the application of supervised machine learning to the stroma-specific multiple SERS signals enables us to support automated differential diagnosis with high accuracy. The results suggest that SERS-derived biochemical fingerprints derived from redox metabolites account for a hallmark of desmoplastic reaction of IBC that is absent in DCIS, and thus, they serve as a useful method for precision diagnosis in breast cancer.

19.
Cell Stem Cell ; 30(6): 766-780.e9, 2023 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-37267913

RESUMEN

iPSC-based drug discovery led to a phase 1/2a trial of ropinirole in ALS. 20 participants with sporadic ALS received ropinirole or placebo for 24 weeks in the double-blind period to evaluate safety, tolerability, and therapeutic effects. Adverse events were similar in both groups. During the double-blind period, muscle strength and daily activity were maintained, but a decline in the ALSFRS-R, which assesses the functional status of ALS patients, was not different from that in the placebo group. However, in the open-label extension period, the ropinirole group showed significant suppression of ALSFRS-R decline and an additional 27.9 weeks of disease-progression-free survival. iPSC-derived motor neurons from participants showed dopamine D2 receptor expression and a potential involvement of the SREBP2-cholesterol pathway in therapeutic effects. Lipid peroxide represents a clinical surrogate marker to assess disease progression and drug efficacy. Limitations include small sample sizes and high attrition rates in the open-label extension period, requiring further validation.


Asunto(s)
Esclerosis Amiotrófica Lateral , Células Madre Pluripotentes Inducidas , Humanos , Esclerosis Amiotrófica Lateral/tratamiento farmacológico , Indoles/efectos adversos , Indoles/farmacología , Neuronas Motoras
20.
Cell Rep ; 42(6): 112610, 2023 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-37294636

RESUMEN

Group 2 innate lymphoid cells (ILC2s) produce large amounts of type 2 cytokines including interleukin-5 (IL-5) and IL-13 in response to various stimuli, causing allergic and eosinophilic diseases. However, the cell-intrinsic regulatory mechanisms of human ILC2s remain unclear. Here, we analyze human ILC2s derived from different tissues and pathological conditions and identify ANXA1, encoding annexin A1, as a commonly highly expressed gene in non-activated ILC2s. The expression of ANXA1 decreases when ILC2s activate, but it increases autonomously as the activation subsides. Lentiviral vector-based gene transfer experiments show that ANXA1 suppresses the activation of human ILC2s. Mechanistically, ANXA1 regulates the expression of the metallothionein family genes, including MT2A, which modulate intracellular zinc homeostasis. Furthermore, increased intracellular zinc levels play an essential role in the activation of human ILC2s by promoting the mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB) pathways and GATA3 expression. Thus, the ANXA1/MT2A/zinc pathway is identified as a cell-intrinsic metalloregulatory mechanism for human ILC2s.


Asunto(s)
Anexina A1 , Inmunidad Innata , Humanos , Linfocitos/metabolismo , Zinc/metabolismo , Citocinas/metabolismo
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