Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Nature ; 512(7514): 324-7, 2014 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-25043048

RESUMEN

Monoallelic point mutations of isocitrate dehydrogenase type 1 (IDH1) are an early and defining event in the development of a subgroup of gliomas and other types of tumour. They almost uniformly occur in the critical arginine residue (Arg 132) in the catalytic pocket, resulting in a neomorphic enzymatic function, production of the oncometabolite 2-hydroxyglutarate (2-HG), genomic hypermethylation, genetic instability and malignant transformation. More than 70% of diffuse grade II and grade III gliomas carry the most frequent mutation, IDH1(R132H) (ref. 3). From an immunological perspective, IDH1(R132H) represents a potential target for immunotherapy as it is a tumour-specific potential neoantigen with high uniformity and penetrance expressed in all tumour cells. Here we demonstrate that IDH1(R132H) contains an immunogenic epitope suitable for mutation-specific vaccination. Peptides encompassing the mutated region are presented on major histocompatibility complexes (MHC) class II and induce mutation-specific CD4(+) T-helper-1 (TH1) responses. CD4(+) TH1 cells and antibodies spontaneously occurring in patients with IDH1(R132H)-mutated gliomas specifically recognize IDH1(R132H). Peptide vaccination of mice devoid of mouse MHC and transgenic for human MHC class I and II with IDH1(R132H) p123-142 results in an effective MHC class II-restricted mutation-specific antitumour immune response and control of pre-established syngeneic IDH1(R132H)-expressing tumours in a CD4(+) T-cell-dependent manner. As IDH1(R132H) is present in all tumour cells of these slow-growing gliomas, a mutation-specific anti-IDH1(R132H) vaccine may represent a viable novel therapeutic strategy for IDH1(R132H)-mutated tumours.


Asunto(s)
Vacunas contra el Cáncer/inmunología , Vacunas contra el Cáncer/uso terapéutico , Glioma/inmunología , Glioma/terapia , Isocitrato Deshidrogenasa/genética , Isocitrato Deshidrogenasa/inmunología , Proteínas Mutantes/inmunología , Animales , Especificidad de Anticuerpos , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/inmunología , Femenino , Glioma/enzimología , Glioma/genética , Antígenos de Histocompatibilidad Clase II/inmunología , Humanos , Inmunidad Humoral , Inmunoterapia/métodos , Masculino , Ratones , Proteínas Mutantes/genética , Mutación , Linfocitos T Colaboradores-Inductores/inmunología , Ensayos Antitumor por Modelo de Xenoinjerto
2.
J Immunol ; 198(8): 3109-3117, 2017 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-28264972

RESUMEN

The development of rheumatoid arthritis (RA) is linked to functional changes in synovial fibroblasts (SF) and local infiltration of T lymphocytes. Fibroblasts possess the capacity to suppress T cell responses, although the molecular mechanisms of this suppression remain incompletely understood. In this study, we aimed to define the mechanisms by which noninflammatory SF modulate Th cell responses and to determine the immunosuppressive efficacy of RASF. Hence, the influence of SF from osteoarthritis or RA patients on total Th cells or different Th cell subsets of healthy donors was analyzed in vitro. We show that SF strongly suppressed the proliferation of Th cells and the secretion of IFN-γ in a cell contact-independent manner. In cocultures of SF and Th cells, tryptophan was completely depleted within a few days, resulting in eukaryotic initiation factor 2α phosphorylation, TCRζ-chain downregulation, and proliferation arrest. Blocking IDO1 activity completely restored Th cell proliferation, but not IFN-γ production. Interestingly, only the proliferation of Th1 cells, but not of Th2 or Th17 cells, was affected. Finally, RASF had a significantly lower IDO1 expression and a weaker Th cell suppressive capacity compared with osteoarthritis SF. We postulate that the suppression of Th cell growth by SF through tryptophan catabolism may play an important role in preventing inappropriate Th cell responses under normal conditions. However, expansion of Th17 cells that do not induce IDO1-mediated suppression and the reduced capacity of RASF to restrict Th cell proliferation through tryptophan metabolism may support the initiation and propagation of synovitis in RA patients.


Asunto(s)
Artritis Reumatoide/inmunología , Fibroblastos/inmunología , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Células TH1/inmunología , Triptófano/metabolismo , Diferenciación Celular/inmunología , Cromatografía Líquida de Alta Presión , Técnicas de Cocultivo , Fibroblastos/metabolismo , Humanos , Immunoblotting , Indolamina-Pirrol 2,3,-Dioxigenasa/inmunología , Activación de Linfocitos/inmunología , Osteoartritis/inmunología , Reacción en Cadena de la Polimerasa , Membrana Sinovial/inmunología , Células Th17/inmunología , Células Th2/inmunología , Triptófano/inmunología
3.
J Biol Chem ; 289(19): 13503-18, 2014 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-24671420

RESUMEN

The cell adhesion molecule L1 is a Lewis(x)-carrying glycoprotein that plays important roles in the developing and adult nervous system. Here we show that myelin basic protein (MBP) binds to L1 in a Lewis(x)-dependent manner. Furthermore, we demonstrate that MBP is released by murine cerebellar neurons as a sumoylated dynamin-containing protein upon L1 stimulation and that this MBP cleaves L1 as a serine protease in the L1 extracellular domain at Arg(687) yielding a transmembrane fragment that promotes neurite outgrowth and neuronal survival in cell culture. L1-induced neurite outgrowth and neuronal survival are reduced in MBP-deficient cerebellar neurons and in wild-type cerebellar neurons in the presence of an MBP antibody or L1 peptide containing the MBP cleavage site. Genetic ablation of MBP in shiverer mice and mutagenesis of the proteolytically active site in MBP or of the MBP cleavage site within L1 as well as serine protease inhibitors and an L1 peptide containing the MBP cleavage site abolish generation of the L1 fragment. Our findings provide evidence for novel functions of MBP in the nervous system.


Asunto(s)
Proteína Básica de Mielina/metabolismo , Molécula L1 de Adhesión de Célula Nerviosa/metabolismo , Neuritas/metabolismo , Proteolisis , Animales , Dominio Catalítico , Supervivencia Celular/fisiología , Ratones , Ratones Mutantes , Mutagénesis , Proteína Básica de Mielina/genética , Molécula L1 de Adhesión de Célula Nerviosa/genética , Estructura Terciaria de Proteína
4.
J Immunother Cancer ; 11(11)2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37963637

RESUMEN

BACKGROUND: The metabolism of tryptophan to kynurenines (KYN) by indoleamine-2,3-dioxygenase or tryptophan-2,3-dioxygenase is a key pathway of constitutive and adaptive tumor immune resistance. The immunosuppressive effects of KYN in the tumor microenvironment are predominantly mediated by the aryl hydrocarbon receptor (AhR), a cytosolic transcription factor that broadly suppresses immune cell function. Inhibition of AhR thus offers an antitumor therapy opportunity via restoration of immune system functions. METHODS: The expression of AhR was evaluated in tissue microarrays of head and neck squamous cell carcinoma (HNSCC), non-small cell lung cancer (NSCLC) and colorectal cancer (CRC). A structure class of inhibitors that block AhR activation by exogenous and endogenous ligands was identified, and further optimized, using a cellular screening cascade. The antagonistic properties of the selected AhR inhibitor candidate BAY 2416964 were determined using transactivation assays. Nuclear translocation, target engagement and the effect of BAY 2416964 on agonist-induced AhR activation were assessed in human and mouse cancer cells. The immunostimulatory properties on gene and cytokine expression were examined in human immune cell subsets. The in vivo efficacy of BAY 2416964 was tested in the syngeneic ovalbumin-expressing B16F10 melanoma model in mice. Coculture of human H1299 NSCLC cells, primary peripheral blood mononuclear cells and fibroblasts mimicking the human stromal-tumor microenvironment was used to assess the effects of AhR inhibition on human immune cells. Furthermore, tumor spheroids cocultured with tumor antigen-specific MART-1 T cells were used to study the antigen-specific cytotoxic T cell responses. The data were analyzed statistically using linear models. RESULTS: AhR expression was observed in tumor cells and tumor-infiltrating immune cells in HNSCC, NSCLC and CRC. BAY 2416964 potently and selectively inhibited AhR activation induced by either exogenous or endogenous AhR ligands. In vitro, BAY 2416964 restored immune cell function in human and mouse cells, and furthermore enhanced antigen-specific cytotoxic T cell responses and killing of tumor spheroids. In vivo, oral application with BAY 2416964 was well tolerated, induced a proinflammatory tumor microenvironment, and demonstrated antitumor efficacy in a syngeneic cancer model in mice. CONCLUSIONS: These findings identify AhR inhibition as a novel therapeutic approach to overcome immune resistance in various types of cancers.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Dioxigenasas , Neoplasias de Cabeza y Cuello , Neoplasias Pulmonares , Humanos , Ratones , Animales , Triptófano , Receptores de Hidrocarburo de Aril/genética , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Leucocitos Mononucleares/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Quinurenina/metabolismo , Inmunoterapia , Factores Inmunológicos , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Microambiente Tumoral
5.
Clin Cancer Res ; 25(1): 253-265, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30274984

RESUMEN

PURPOSE: Resistance is an obstacle of glioma therapy. Despite targeted interventions, tumors harbor primary resistance or become resistant over short course of treatment. This study examined the mouse double minute 2 (MDM2) inhibitor RG7388 together with radiotherapy and analyzed strategies to overcome acquired MDM2 inhibitor resistance in glioblastoma. EXPERIMENTAL DESIGN: Effects of RG7388 and radiotherapy were analyzed in p53 wild-type glioblastoma cell lines and glioma-initiating cells. RG7388 resistant cells were generated by increasing RG7388 doses over 3 months. Regulated pathways were investigated by microarray, qRT-PCR, and immunoblot analysis and specifically inhibited to evaluate rational salvage therapies at RG7388 resistance. Effects of RG7388 and trametinib treatment were challenged in an orthotopical mouse model with RG7388 resistant U87MG glioblastoma cells. RESULTS: MDM2 inhibition required functional p53 and showed synergistic activity with radiotherapy in first-line treatment. Long-term exposure to RG7388 induced resistance by activation of the extracellular signal-regulated kinases 1/2 (ERK1/2)-insulin growth factor binding protein 1 (IGFBP1) signaling cascade, which was specifically overcome by ERK1/2 pathway inhibition with trametinib and knockdown of IGFBP1. Combining trametinib with continued RG7388 treatment enhanced antitumor effects at RG7388 resistance in vitro and in vivo. CONCLUSIONS: These data provide a rationale for combining RG7388 and radiotherapy as first-line therapy with a specific relevance for tumors insensitive to alkylating standard chemotherapy and for the addition of trametinib to continued RG7388 treatment as salvage therapy after acquired resistance against RG7388 for clinical practice.


Asunto(s)
Glioblastoma/tratamiento farmacológico , Proteína 1 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Proteínas Proto-Oncogénicas c-mdm2/genética , Proteína p53 Supresora de Tumor/genética , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Línea Celular Tumoral , Resistencia a Antineoplásicos/efectos de los fármacos , Glioblastoma/genética , Glioblastoma/patología , Glioblastoma/radioterapia , Xenoinjertos , Humanos , Ratones , Piridonas/farmacología , Pirimidinonas/farmacología , Pirrolidinas/farmacología , Transducción de Señal/efectos de los fármacos , para-Aminobenzoatos/farmacología
6.
Nat Commun ; 10(1): 4877, 2019 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-31653831

RESUMEN

The interaction between the mammalian host and its resident gut microbiota is known to license adaptive immune responses. Nutritional constituents strongly influence composition and functional properties of the intestinal microbial communities. Here, we report that omission of a single essential amino acid - tryptophan - from the diet abrogates CNS autoimmunity in a mouse model of multiple sclerosis. Dietary tryptophan restriction results in impaired encephalitogenic T cell responses and is accompanied by a mild intestinal inflammatory response and a profound phenotypic shift of gut microbiota. Protective effects of dietary tryptophan restriction are abrogated in germ-free mice, but are independent of canonical host sensors of intracellular tryptophan metabolites. We conclude that dietary tryptophan restriction alters metabolic properties of gut microbiota, which in turn have an impact on encephalitogenic T cell responses. This link between gut microbiota, dietary tryptophan and adaptive immunity may help to develop therapeutic strategies for protection from autoimmune neuroinflammation.


Asunto(s)
Autoinmunidad/inmunología , Dieta , Encefalomielitis Autoinmune Experimental/inmunología , Microbioma Gastrointestinal/inmunología , Linfocitos T/inmunología , Triptófano , Animales , Proteínas en la Dieta , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/microbiología , Microbioma Gastrointestinal/genética , Ratones , Esclerosis Múltiple , ARN Ribosómico 16S/genética
7.
Nat Med ; 24(8): 1192-1203, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29988124

RESUMEN

The oncometabolite (R)-2-hydroxyglutarate (R-2-HG) produced by isocitrate dehydrogenase (IDH) mutations promotes gliomagenesis via DNA and histone methylation. Here, we identify an additional activity of R-2-HG: tumor cell-derived R-2-HG is taken up by T cells where it induces a perturbation of nuclear factor of activated T cells transcriptional activity and polyamine biosynthesis, resulting in suppression of T cell activity. IDH1-mutant gliomas display reduced T cell abundance and altered calcium signaling. Antitumor immunity to experimental syngeneic IDH1-mutant tumors induced by IDH1-specific vaccine or checkpoint inhibition is improved by inhibition of the neomorphic enzymatic function of mutant IDH1. These data attribute a novel, non-tumor cell-autonomous role to an oncometabolite in shaping the tumor immune microenvironment.


Asunto(s)
Glutaratos/metabolismo , Inmunidad , Linfocitos T/inmunología , Adenosina Trifosfato/metabolismo , Animales , Apoptosis , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/inmunología , Calcio/metabolismo , Línea Celular Tumoral , Proliferación Celular , Glioma/genética , Glioma/inmunología , Humanos , Isocitrato Deshidrogenasa/genética , Isocitrato Deshidrogenasa/metabolismo , Activación de Linfocitos/inmunología , Ratones Endogámicos C57BL , Mutación/genética , Factores de Transcripción NFATC/metabolismo , Comunicación Paracrina , Poliaminas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Transducción de Señal
8.
J Neuroimmunol ; 297: 117-26, 2016 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-27397084

RESUMEN

Relapsing-remitting multiple sclerosis (MS)(2) is characterized by phases of acute neuroinflammation followed by spontaneous remission. Termination of inflammation is accompanied by an influx of regulatory T cells (Tregs).(3) The molecular mechanisms responsible for directing Tregs into the inflamed CNS tissue, however, are incompletely understood. In an MS mouse model we show that the stress kinase general control non-derepressible 2 (GCN2),(4) expressed in T cells, contributes to the resolution of autoimmune neuroinflammation. Failure to recover from acute inflammation was associated with reduced frequencies of CNS-infiltrating Tregs. GCN2 deficient Tregs displayed impaired migration to a CCL2 gradient. These data suggest an important contribution of the T cell stress response to the resolution of autoimmune neuroinflammation.


Asunto(s)
Citocinas/metabolismo , Encefalomielitis Autoinmune Experimental/inmunología , Encefalomielitis Autoinmune Experimental/fisiopatología , Proteínas Serina-Treonina Quinasas/metabolismo , Linfocitos T Reguladores/fisiología , Animales , Anexina A5/metabolismo , Astrocitos/metabolismo , Encéfalo/citología , Movimiento Celular/fisiología , Citocinas/farmacología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Células Endoteliales/fisiología , Femenino , Citometría de Flujo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Glicoproteína Mielina-Oligodendrócito/toxicidad , Fragmentos de Péptidos/toxicidad , Proteínas Serina-Treonina Quinasas/genética , Estadísticas no Paramétricas , Linfocitos T Reguladores/efectos de los fármacos , Factores de Tiempo
9.
J Clin Invest ; 125(2): 593-606, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25555220

RESUMEN

For a targeted cancer vaccine to be effective, the antigen of interest needs to be naturally processed and presented on MHC by the target cell or an antigen-presenting cell (APC) in the tumor stroma. The presence of these characteristics is often assumed based on animal models, evaluation of antigen-overexpressing APCs in vitro, or assays of material-consuming immune precipitation from fresh solid tissue. Here, we evaluated the use of an alternative approach that uses the proximity ligation assay (PLA) to identify the presentation of an MHC class II-restricted antigen in paraffin-embedded tissue sections from patients with brain tumors. This approach required a specific antibody directed against the epitope that was presented. We used an antibody that specifically binds an epitope of mutated isocitrate dehydrogenase type 1 (IDH1R132H), which is frequently expressed in gliomas and other types of tumors. In situ PLA showed that the IDH1R132H epitope colocalizes with MHC class II in IDH1R132H-mutated glioma tissue. Moreover, PLA demonstrated colocalization between the class II epitope-containing melanoma antigen New York esophageal 1 and MHC class II. Collectively, our data suggest that PLA may be a useful tool to acquire information on whether an antigen is presented in situ, and this technique has potential to guide clinical studies that use antigen-specific cancer immunotherapy.


Asunto(s)
Presentación de Antígeno , Células Presentadoras de Antígenos/inmunología , Neoplasias Encefálicas/inmunología , Glioma/inmunología , Inmunohistoquímica/métodos , Isocitrato Deshidrogenasa/inmunología , Mutación Missense , Adulto , Anciano , Anciano de 80 o más Años , Células Presentadoras de Antígenos/metabolismo , Células Presentadoras de Antígenos/patología , Neoplasias Encefálicas/enzimología , Neoplasias Encefálicas/patología , Vacunas contra el Cáncer/genética , Vacunas contra el Cáncer/inmunología , Vacunas contra el Cáncer/metabolismo , Vacunas contra el Cáncer/farmacología , Línea Celular Tumoral , Epítopos/genética , Epítopos/inmunología , Epítopos/metabolismo , Femenino , Glioma/enzimología , Glioma/genética , Glioma/patología , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase II/inmunología , Antígenos de Histocompatibilidad Clase II/metabolismo , Humanos , Isocitrato Deshidrogenasa/genética , Isocitrato Deshidrogenasa/metabolismo , Masculino , Persona de Mediana Edad
10.
Front Immunol ; 5: 673, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25628622

RESUMEN

The tryptophan (TRP) to kynurenine (KYN) metabolic pathway is now firmly established as a key regulator of innate and adaptive immunity. A plethora of preclinical models suggests that this immune tolerance pathway - driven by the key and rate-limiting enzymes indoleamine-2,3-dioxygenase and TRP-2,3-dioxygenase - is active in cancer immunity, autoimmunity, infection, transplant rejection, and allergy. Drugs targeting this pathway, specifically indoleamine-2,3-dioxygenase, are already in clinical trials with the aim at reverting cancer-induced immunosuppression. In the past years, there has been an increase in our understanding of the regulation and downstream mediators of TRP metabolism, such as the aryl hydrocarbon receptor as a receptor for KYN and kynurenic acid. This more detailed understanding will expand our opportunities to interfere with the pathway therapeutically on multiple levels. Here, we discuss the perspective of targeting TRP metabolism at these different levels based on reviewing recent insight into the regulation of TRP metabolism and its downstream effectors.

11.
J Neuroimmunol ; 265(1-2): 106-16, 2013 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-24090655

RESUMEN

Malignant gliomas are primary brain tumors characterized by profound local immunosuppression. While the remarkable plasticity of perivascular cells - resembling mesenchymal stem cells (MSC) - in malignant gliomas and their contribution to angiogenesis is increasingly recognized, their role as potential mediators of immunosuppression is unknown. Here we demonstrate that FACS-sorted malignant glioma-derived pericytes (HMGP) were characterized by the expression of CD90, CD248, and platelet-derived growth factor receptor-ß (PDGFR-ß). HMGP shared this expression profile with human brain vascular pericytes (HBVP) and human MSC (HMSC) but not human cerebral microvascular endothelial cells (HCMEC). CD90+PDGFR-ß+perivascular cells distinct from CD31+ endothelial cells accumulated in human gliomas with increasing degree of malignancy and negatively correlated with the presence of blood vessel-associated leukocytes and CD8+ T cells. Cultured CD90+PDGFR-ß+HBVP were equally capable of suppressing allogeneic or mitogen-activated T cell responses as human MSC. HMGP, HBVP and HMSC expressed prostaglandin E synthase (PGES), inducible nitric oxide synthase (iNOS), human leukocyte antigen-G (HLA-G), hepatocyte growth factor (HGF) and transforming growth factor-ß (TGF-ß). These factors but not indoleamine 2,3-dioxygenase-mediated conversion of tryptophan to kynurenine functionally contributed to immunosuppression of immature pericytes. Our data provide evidence that human cerebral CD90+ perivascular cells possess T cell inhibitory capability comparable to human MSC and suggest that these cells, besides their critical role in tumor vascularization, also promote local immunosuppression in malignant gliomas and possibly other brain diseases.


Asunto(s)
Neoplasias Encefálicas/inmunología , Neoplasias Encefálicas/patología , Glioma/inmunología , Glioma/patología , Terapia de Inmunosupresión , Pericitos/inmunología , Diferenciación Celular , Células Cultivadas , Cromatografía Líquida de Alta Presión , Citometría de Flujo , Antígenos HLA-G/metabolismo , Factor de Crecimiento de Hepatocito/metabolismo , Humanos , Indolamina-Pirrol 2,3,-Dioxigenasa , Interferón gamma/genética , Interferón gamma/metabolismo , Oxidorreductasas Intramoleculares/metabolismo , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/fisiología , Óxido Nítrico Sintasa de Tipo II/metabolismo , Osteogénesis , Pericitos/metabolismo , Prostaglandina-E Sintasas , ARN Mensajero/metabolismo , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Índice de Severidad de la Enfermedad , Antígenos Thy-1/metabolismo
12.
Exp Neurol ; 247: 517-30, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23360803

RESUMEN

Chondroitin sulfate (CS) and dermatan sulfate (DS) proteoglycans are major components of the extracellular matrix implicated in neural development, plasticity and regeneration. While it is accepted that CS are major inhibitors of neural regeneration, the contributions of DS to regeneration have not been assessed. To enable a novel approach in studies on DS versus CS roles during development and regeneration, we generated a mouse deficient in the dermatan 4-O-sulfotransferase1 (Chst14(-/-)), a key enzyme in the synthesis of iduronic acid-containing modules found in DS but not CS. In wild-type mice, Chst14 is expressed at high levels in the skin and in the nervous system, and is enriched in astrocytes and Schwann cells. Ablation of Chst14, and the assumed failure to produce DS, resulted in smaller body mass, reduced fertility, kinked tail and increased skin fragility compared with wild-type (Chst14(+/+)) littermates, but brain weight and gross anatomy were unaffected. Neurons and Schwann cells from Chst14(-/-) mice formed longer processes in vitro, and Chst14(-/-) Schwann cells proliferated more than Chst14(+/+) Schwann cells. After femoral nerve transection/suture, functional recovery and axonal regrowth in Chst14(-/-) mice were initially accelerated but the final outcome 3months after injury was not better than that in Chst14(+/+) littermates. These results suggest that while Chst14 and its enzymatic products might be of limited importance for neural development, they may contribute to the regeneration-restricting environment in the adult mammalian nervous system.


Asunto(s)
Neuropatía Femoral/patología , Neuropatía Femoral/fisiopatología , Regulación del Desarrollo de la Expresión Génica/genética , Regeneración Nerviosa/genética , Neuronas/fisiología , Sulfotransferasas/deficiencia , Factores de Edad , Animales , Animales Recién Nacidos , Axones/patología , Índice de Masa Corporal , Proliferación Celular , Células Cultivadas , Modelos Animales de Enfermedad , Ganglios Espinales/citología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Actividad Motora/genética , Vaina de Mielina/metabolismo , Neuritas/fisiología , Neuroglía/fisiología , Neuronas/citología , Células de Schwann/patología , Células de Schwann/fisiología , Células de Schwann/ultraestructura , Sulfotransferasas/genética , Degeneración Walleriana/patología , Degeneración Walleriana/fisiopatología , Carbohidrato Sulfotransferasas
13.
Cancer Res ; 73(11): 3225-34, 2013 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-23548271

RESUMEN

Quinolinic acid is a product of tryptophan degradation and may serve as a precursor for NAD(+), an important enzymatic cofactor for enzymes such as the DNA repair protein PARP. Pathologic accumulation of quinolinic acid has been found in neurodegenerative disorders including Alzheimer and Huntington disease, where it is thought to be toxic for neurons by activating the N-methyl-D-aspartate (NMDA) receptor and inducing excitotoxicity. Although many tumors including gliomas constitutively catabolize tryptophan, it is unclear whether quinolinic acid is produced in gliomas and whether it is involved in tumor progression. Here, we show that quinolinic acid accumulated in human gliomas and was associated with a malignant phenotype. Quinolinic acid was produced by microglial cells, as expression of the quinolinic acid-producing enzyme 3-hydroxyanthranilate oxygenase (3-HAO) was confined to microglia in glioma tissue. Human malignant glioma cells, but not nonneoplastic astrocytes, expressed quinolinic acid phosphoribosyltransferase (QPRT) to use quinolinic acid for NAD(+) synthesis and prevent apoptosis when de novo NAD(+) synthesis was blocked. Oxidative stress, temozolomide, and irradiation induced QPRT in glioma cells. QPRT expression increased with malignancy. In recurrent glioblastomas after radiochemotherapy, QPRT expression was associated with a poor prognosis in two independent datasets. Our data indicate that neoplastic transformation in astrocytes is associated with a QPRT-mediated switch in NAD(+) metabolism by exploiting microglia-derived quinolinic acid as an alternative source of replenishing intracellular NAD(+) pools. The elevated levels of QPRT expression increase resistance to oxidative stress induced by radiochemotherapy, conferring a poorer prognosis. These findings have implications for therapeutic approaches inducing intracellular NAD(+) depletion, such as alkylating agents or direct NAD(+) synthesis inhibitors, and identify QPRT as a potential therapeutic target in malignant gliomas.


Asunto(s)
Glioma/metabolismo , NAD/metabolismo , Estrés Oxidativo/fisiología , Ácido Quinolínico/metabolismo , Triptófano/metabolismo , Antineoplásicos Alquilantes/farmacología , Apoptosis/fisiología , Línea Celular Tumoral , Dacarbazina/análogos & derivados , Dacarbazina/farmacología , Resistencia a Antineoplásicos , Glioma/patología , Humanos , Microglía/enzimología , Microglía/metabolismo , Microglía/patología , Estrés Oxidativo/efectos de los fármacos , Pentosiltransferasa/metabolismo , Temozolomida , Triptófano Oxigenasa/metabolismo
14.
Neurobiol Dis ; 28(2): 165-74, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17761426

RESUMEN

Defects of adrenoleukodystrophy protein (ALDP) lead to X-linked adrenoleukodystrophy (X-ALD), a disorder mainly affecting the nervous system white matter and the adrenal cortex. In the present study, we examine the expression of ALDP in various human tissues and cell lines by multiple-tissue RNA expression array analysis, Western blot analysis, and immunohistochemistry. ALDP-encoding mRNA is most abundant in tissues with high energy requirements such as heart, muscle, liver, and the renal and endocrine systems. ALDP selectively occurs in specific cell types of brain (hypothalamus and basal nucleus of Meynert), kidney (distal tubules), skin (eccrine gland, hair follicles, and fibroblasts), colon (ganglion cells and epithelium), adrenal gland (zona reticularis and fasciculata), and testis (Sertoli and Leydig cells). In pituitary gland, ALDP is confined to adrenocorticotropin-producing cells and is significantly reduced in individuals receiving long term cortisol treatment. This might indicate a functional link between ALDP and proopiomelanocortin-derived peptide hormones.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/metabolismo , Encéfalo/metabolismo , Piel/metabolismo , Vísceras/metabolismo , Miembro 1 de la Subfamilia D de Transportador de Casetes de Unión al ATP , Transportadoras de Casetes de Unión a ATP/genética , Adolescente , Corteza Suprarrenal/citología , Corteza Suprarrenal/metabolismo , Adrenoleucodistrofia/genética , Adrenoleucodistrofia/metabolismo , Adrenoleucodistrofia/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Encéfalo/citología , Encéfalo/fisiopatología , Niño , Colon/citología , Colon/metabolismo , Metabolismo Energético/fisiología , Femenino , Humanos , Inmunohistoquímica/métodos , Lactante , Riñón/citología , Riñón/metabolismo , Masculino , Persona de Mediana Edad , Hipófisis/citología , Hipófisis/metabolismo , Proopiomelanocortina/metabolismo , ARN Mensajero/análisis , ARN Mensajero/metabolismo , Piel/citología , Testículo/citología , Testículo/metabolismo , Vísceras/citología
15.
Hum Mol Genet ; 14(9): 1127-37, 2005 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-15772093

RESUMEN

X-linked adrenoleukodystrophy (X-ALD, OMIM 300100) is a severe inherited neurodegenerative disease, associated with the accumulation of very long-chain fatty acids (VLCFA). The recent unexpected observation that the accumulation of VLCFA in tissues of the Abcd1-deficient mouse model for X-ALD is not due to a deficiency in VLCFA degradation, led to the hypothesis that mitochondrial abnormalities might contribute to X-ALD pathology. Here, we report that in spite of substantial accumulation of VLCFA in whole muscle homogenates, normal VLCFA levels were detected in mitochondria obtained by organellar fractionation. Polarographic analyses of the respiratory chain as well as enzymatic assays of isolated muscle mitochondria revealed no differences between X-ALD and control mice. Moreover, analysis by electron microscopy, revealed normal size, structure and localization of mitochondria in muscle of both groups. Similar to the results obtained in skeletal muscle, the mitochondrial enzyme activities in brain homogenates of Abcd1-deficient and wild-type animals also did not differ. Finally, studies on mitochondrial oxidative phosphorylation in permeabilized human skin fibroblasts of X-ALD patients and controls revealed no abnormalities. Thus, we conclude that the accumulation of VLCFA per se does not cause mitochondrial abnormalities and vice versa-mitochondrial abnormalities are not responsible for the accumulation of VLCFA in X-ALD mice.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/genética , Adrenoleucodistrofia/genética , Adrenoleucodistrofia/metabolismo , Ácidos Grasos no Esterificados/biosíntesis , Mitocondrias/metabolismo , Miembro 1 de la Subfamilia D de Transportador de Casetes de Unión al ATP , Adenosina Trifosfato/análisis , Adenosina Trifosfato/biosíntesis , Animales , Encéfalo/enzimología , Encéfalo/ultraestructura , Fraccionamiento Celular , Células Cultivadas , Diafragma/ultraestructura , Fibroblastos/metabolismo , Glucosa/metabolismo , Humanos , Ácido Láctico/biosíntesis , Masculino , Ratones , Ratones Noqueados , Mitocondrias/enzimología , Mitocondrias/ultraestructura , Músculo Esquelético/enzimología , Músculo Esquelético/ultraestructura , Fosforilación Oxidativa , Ácido Pirúvico/metabolismo , Piel/citología , Fracciones Subcelulares/metabolismo , Cromosoma X
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA