Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Arch Toxicol ; 96(9): 2511-2521, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35748891

RESUMEN

The HepaRG cell line represents a successful model for hepatotoxicity studies. These cells are of human origin and are differentiated in vitro into mature and functional hepatocyte-like cells. The objective of this research was to compare two different culture protocols, Sison-Young et al. 2017 (hereinafter referred as Sison) and Gripon et al. 2002 (hereinafter referred as Biopredic) for HepaRG cells in order to optimise this model for drug metabolism and toxicity testing studies. HepaRG cells obtained from the same batch were cultured according to the described protocols. Using both protocols, differentiated HepaRG cells retained their drug metabolic capacity (major phase I/II enzymes) and transporters, as well as their morphological characteristics. Morphologically, HepaRG cells cultured after the Biopredic protocol formed more apical membranes and small ductular-like structures, than those cultivated using the Sison protocol. Also, the efflux activity of multidrug resistance protein 1 (MDR1) and multidrug resistance-associated protein 1 (MRP1) as well as the activity of uridine-glucuronosyltransferase (UGT) and glutathione S-transferase (GST) were significantly reduced in HepaRG cultured using the Sison protocol. Applying well-established drug cocktails to measure cytochrome P450 (CYPs) activity, we found that production of the corresponding metabolites was hampered in Sison-cultured HepaRG cells, indicating that the activity of CYP1A2, CYP2C9, CYP3A4, CYP2B6 and CYP2C19 was significantly reduced. Moreover, HepaRG sensitivity to well-known drugs, namely diclofenac, amiodarone, imipramine and paracetamol, revealed some differences between the two culture protocols. Furthermore, the HepaRG cells can be maintained with higher viability and sufficient CYPs activity and expression (i.e. CYP3A4, CYP1A2 and CYP2B6) as well as liver-specific functions, using Biopredic compared with the Sison culture protocol. These maintained liver-specific functions might be dependent on the prolongation of the culture conditions in the case of the Biopredic protocol. In conclusion, based on the metabolic activity of HepaRG cells using the standard protocol from Biopredic, we believe that this protocol is optimal for investigating drug metabolism and pharmacokinetic screening studies.


Asunto(s)
Citocromo P-450 CYP1A2 , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Línea Celular , Citocromo P-450 CYP1A2/metabolismo , Citocromo P-450 CYP2B6 , Citocromo P-450 CYP3A/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/metabolismo , Hepatocitos/metabolismo , Humanos
2.
Ann Surg ; 270(2): 327-332, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-29916882

RESUMEN

OBJECTIVE: to report the first case of resection and partial liver segment 2-3 transplantation with delayed total hepatectomy (RAPID) from living donor in a patient affected of irresectable colorectal liver metastases (i-CRLM) BACKGROUND:: A renaissance of liver transplantation (LT) for i-CRLM has been recently observed. The Norwegian SECA trial demonstrated a 5-year overall survival rate of approximately 60%, notwithstanding early tumor recurrence. The RAPID technique was recently introduced as alternative to whole deceased donor LT, but it is limited by poor availability of splittable organs and many organisational aspects. In this context left lateral living donor LT may be the ideal solution. METHODS: Report about the technique and results of living donor RAPID procedure. TECHNIQUE: A 49 years old woman affected with i-CRLM from adenocarcinoma of right colon, underwent a left hepatectomy with ligation of right portal vein maintaining the right hepatic artery patent. Subsequently, the left lateral lobe from her son was implanted as auxiliary partial orthotopic LT. Two weeks later completion of hepatectomy was performed. RESULTS: The donor postoperative course was uneventful. The recipient developed postoperatively a slight small for size syndrome which spontaneously resolved. No graft dysfunction and no rejection were observed. At POM 5 micrometastases occurred in bones and lungs, which were treated with radiotherapy and chemotherapy, respectively. Almost 2 years later the patient is alive, in good general condition, although slight progression of bone and lung metastases. CONCLUSIONS: LT poses a valid treatment option for i-CRLM. In times of organ paucity, "living donor-RAPID" procedure may represent a paradigm shift in the management of i-CRLM.


Asunto(s)
Neoplasias Colorrectales/patología , Hepatectomía/métodos , Neoplasias Hepáticas/cirugía , Trasplante de Hígado/métodos , Donadores Vivos , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/secundario , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X , Ultrasonografía Doppler , Adulto Joven
3.
Nephrol Dial Transplant ; 31(9): 1444-52, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-26908771

RESUMEN

BACKGROUND: Human lifespan is increasing continuously and about one-third of the population >70 years of age suffers from chronic kidney disease. The pathophysiology of the loss of renal function with ageing is unclear. METHODS: We determined age-associated gene expression changes in zero-hour biopsies of deceased donor kidneys without laboratory signs of impaired renal function, defined as a last serum creatinine >0.96 mg/dL in females and >1.18 mg/dL in males, using microarray technology and the Significance Analysis of Microarrays routine. Expression changes of selected genes were confirmed by quantitative polymerase chain reaction and in situ hybridization and immunohistochemistry for localization of respective mRNA and protein. Functional aspects were examined in vitro. RESULTS: Donors were classified into three age groups (<40, 40-59 and >59 years; Groups 1, 2 and 3, respectively). In Group 3 especially, genes encoding for metallothionein (MT) isoforms were more significantly expressed when compared with Group 1; localization studies revealed predominant staining in renal proximal tubular cells. RPTEC/TERT1 cells overexpressing MT2A were less susceptible towards cadmium chloride-induced cytotoxicity and hypoxia-induced apoptosis, both models for increased generation of reactive oxygen species. CONCLUSIONS: Increased expression of MTs in the kidney with ageing might be a protective mechanism against increased oxidative stress, which is closely related to the ageing process. Our findings indicate that MTs are functionally involved in the pathophysiology of ageing-related processes.


Asunto(s)
Envejecimiento/patología , Biomarcadores/metabolismo , Riñón/metabolismo , Riñón/patología , Metalotioneína/metabolismo , Estrés Oxidativo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Femenino , Perfilación de la Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Oxidación-Reducción , Especies Reactivas de Oxígeno/metabolismo , Adulto Joven
4.
J Clin Med ; 13(8)2024 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-38673695

RESUMEN

(1) Background: Laparoscopic staging is essential in gastric cancer (GC) to rule out peritoneal metastasis (PM). Hypericin, a plant-derived fluorescent compound, has been suggested to improve laparoscopic visualization of PM from GC. This prospective, single-arm, open-label clinical trial aimed to assess the feasibility and safety of oral hypericin administration as well as the suitability of fluorescence-guided laparoscopy (FGL) for improving the sensitivity and specificity of staging in GC patients (EudraCT-Number: 2015-005277-21; clinicaltrials.gov identifier: NCT-02840331). (2) Methods: GC patients received Laif® 900, an approved hypericin-containing phytopharmaceutical, once orally two to four hours before white light and ultraviolet light laparoscopy. The peritoneal cancer index was evaluated, biopsies taken and hypericin concentrations in serum and peritoneal tissue were determined by mass spectrometry. (3) Results: Between 2017 and 2021, out of 63 patients screened for eligibility, 50 patients were enrolled and treated per protocol. The study intervention was shown to be feasible and safe in all patients. Standard laparoscopy revealed suspicious lesions in 27 patients (54%), among whom 16 (59%) were diagnosed with PM. FGL identified suspicious areas in 25 patients (50%), among whom PM was confirmed in 13 cases (52%). Although hypericin concentrations in serum reached up to 5.64 ng/mL, no hypericin was detectable in peritoneal tissue biopsies. (4) Conclusions: FGL in patients with GC was shown to be feasible but futile in this study. Sufficient levels of hypericin should be ensured in target tissue prior to reassessing FGL with hypericin.

5.
Circ Res ; 108(6): 695-703, 2011 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-21293004

RESUMEN

RATIONALE: There is strong evidence that oxidative modification of low-density lipoprotein (oxLDL) plays a critical role in atherogenesis and that oxLDL may profoundly influence the mechanical stability of atherosclerotic plaques. OBJECTIVE: To block oxLDL, we designed, expressed, and tested Fc-CD68, a soluble oxLDL binding protein consisting of human Fc and the extracellular domain of the human oxLDL-binding receptor CD68. METHODS AND RESULTS: Fc-CD68 bound with high specific affinity to oxLDL and strongly bound and colocalized with oxLDL in plaques. To study the effects of repeated administrations of Fc-CD68 on the progression of atherosclerosis and plaque vulnerability, 12- and 16-week old cholesterol-fed ApoE(-/-) mice received either Fc-CD68 (n = 6) or Fc control protein (n = 6 to 8) thrice weekly for 4 weeks. Macroscopic and histological analysis of Sudan red lipid staining showed strong and significant reduction of plaque extension in the aorta and in the aortic root, respectively. Histological analysis of pentachrome- and Sirius-stained sections of the brachiocephalic arteries of 20 week-old ApoE(-/-) mice revealed that Fc-CD68 significantly reduced the occurrence of spontaneous ruptures of established plaques by ≈20%, compared with Fc and drastically increased the collagen content of plaques. Furthermore, in immunostained sections of the brachiocephalic artery and the aortic root, Fc-CD68 reduced the infiltration of plaques with T lymphocytes, and macrophages by ≈50% and 30%, respectively. CONCLUSIONS: The oxLDL binding protein Fc-CD68 attenuates atherosclerosis and strengthens the stability of atherosclerotic plaques.


Asunto(s)
Antígenos CD/genética , Antígenos de Diferenciación Mielomonocítica/genética , Aterosclerosis/patología , Tronco Braquiocefálico/efectos de los fármacos , Tronco Braquiocefálico/patología , Fragmentos Fc de Inmunoglobulinas/genética , Placa Aterosclerótica/patología , Proteínas Recombinantes de Fusión/farmacología , Animales , Aorta/efectos de los fármacos , Aorta/patología , Apolipoproteínas E/deficiencia , Aterosclerosis/metabolismo , Unión Competitiva , Proteínas Portadoras/metabolismo , Proteínas Portadoras/farmacología , Colágeno/metabolismo , Progresión de la Enfermedad , Humanos , Inflamación/metabolismo , Inflamación/patología , Metabolismo de los Lípidos , Lipoproteínas LDL/metabolismo , Macrófagos/patología , Masculino , Ratones , Ratones Noqueados , Placa Aterosclerótica/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Linfocitos T/patología
6.
Cancers (Basel) ; 15(24)2023 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-38136299

RESUMEN

Patient-derived xenograft (PDX) tumor models are essential for identifying new biomarkers, signaling pathways and novel targets, to better define key factors of therapy response and resistance mechanisms. Therefore, this study aimed at establishing pancreas carcinoma (PC) PDX models with thorough molecular characterization, and the identification of signatures defining responsiveness toward drug treatment. In total, 45 PC-PDXs were generated from 120 patient tumor specimens and the identity of PDX and corresponding patient tumors was validated. The majority of engrafted PDX models represent ductal adenocarcinomas (PDAC). The PDX growth characteristics were assessed, with great variations in doubling times (4 to 32 days). The mutational analyses revealed an individual mutational profile of the PDXs, predominantly showing alterations in the genes encoding KRAS, TP53, FAT1, KMT2D, MUC4, RNF213, ATR, MUC16, GNAS, RANBP2 and CDKN2A. Sensitivity of PDX toward standard of care (SoC) drugs gemcitabine, 5-fluorouracil, oxaliplatin and abraxane, and combinations thereof, revealed PDX models with sensitivity and resistance toward these treatments. We performed correlation analyses of drug sensitivity of these PDX models and their molecular profile to identify signatures for response and resistance. This study strongly supports the importance and value of PDX models for improvement in therapies of PC.

7.
Am J Physiol Endocrinol Metab ; 300(2): E321-6, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21045174

RESUMEN

Stearoyl-CoA desaturase-1 (SCD1) has gained much interest as a future drug target to treat fatty liver and its consequences. However, there are few and inconsistent human data about expression and activity of this important enzyme. We investigated activity and expression of SCD1 and their relationships with liver fat (LF) content in human liver samples. Fifty subjects undergoing liver surgery were studied. SCD1 activity was estimated from the ratio of oleate (C18:1) to stearate (C18:0) within lipid subfractions. Furthermore, SCD1 mRNA expression and LF content were measured. Similarly to previous studies, we observed a strong positive correlation between LF content and the C18:1/C18:0 ratio in the combined fatty acid (FA) fractions (r = 0.96, P < 0.0001), which could be interpreted as higher SCD1 activity with increasing LF. However, hepatic SCD1 mRNA expression did not correlate with LF (r = 0.16, P = 0.13). To solve these conflicting data, we analyzed the FA composition of hepatic lipid subfractions. With increasing LF content the amount of FAs from the triglyceride (TG) fraction increased (r = 0.96, P < 0.0001), whereas the FAs from the phospholipid (PL) fraction remained unchanged (r = -0.17, P = 0.19). Of these two major lipid fractions, the C18:1/C18:0 ratio in TG was 16-fold higher than in PL. Supporting the SCD1 mRNA expression data, the C18:1/C18:0 ratio of the TG or PL fraction did not correlate with LF (r = 0.26, P = 0.12 and r = 0.08, P = 0.29). We provide novel information that SCD1 activity and mRNA expression appear not to be elevated in subjects with high LF content. We suggest that the FA composition of lipid subclasses, rather than of mixed lipids, should be analyzed to estimate SCD1 activity.


Asunto(s)
Metabolismo de los Lípidos/fisiología , Hígado/enzimología , Hígado/metabolismo , ARN Mensajero/biosíntesis , Estearoil-CoA Desaturasa/metabolismo , Anciano , Biopsia , Ésteres del Colesterol/metabolismo , Ácidos Grasos/metabolismo , Femenino , Humanos , Neoplasias Hepáticas/metabolismo , Masculino , Persona de Mediana Edad , Fosfolípidos/metabolismo , ARN Mensajero/genética , Triglicéridos/metabolismo
8.
J Mol Cell Cardiol ; 49(3): 532-42, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20430036

RESUMEN

Glycoprotein VI (GPVI) mediates binding of platelets to subendothelial collagen during acute arterial thrombosis. GPVI interactions with the activated atherosclerotic vascular endothelium during early atherosclerosis, however, are not well understood. In ApoE-/- mice, platelet adhesion to atherosclerotic arteries was increased, as measured by intravital microscopy. This platelet adhesion was significantly inhibited by IV injection of GPVI-Fc (1 mg/kg body weight). Atherosclerosis in ApoE-/- mice was attenuated both after 7 and 10 weeks of treatment with the anti-GPVI antibody JAQ1 (2 mg/kg body weight i.p. twice weekly). Binding of GPVI-Fc (1 mg/kg IV) occurred to deeper layers, but also to the luminal site of plaques in atherosclerotic rabbits, but not to the vessel wall of healthy littermates. Gene transfer of GPVI-Fc to the carotid vascular wall significantly attenuated athero-progression and endothelial dysfunction in atherosclerotic rabbits in vivo. Specific binding of the soluble GPVI receptor (GPVI-Fc) to fibronectin was found in vitro to coated ELISA plates. Platelet adhesion to fibronectin was significantly inhibited both by GPVI-Fc and by the anti-GPVI antibody 5C4 ex vivo in flow chamber experiments. GPVI plays a role in platelet adhesion to atherosclerotic endothelium in the absence of plaque rupture. Inhibition of GPVI both via GPVI-Fc and anti-GPVI-antibodies results in protection against atherosclerosis in both cholesterol-fed rabbits and ApoE-/- mice. This novel mechanism of GPVI-mediated platelet adhesion-possibly via fibronectin-could relevantly contribute to platelet-triggered atheroprogression.


Asunto(s)
Aterosclerosis/patología , Endotelio Vascular/metabolismo , Fibronectinas/metabolismo , Adhesividad Plaquetaria/fisiología , Glicoproteínas de Membrana Plaquetaria/metabolismo , Adenoviridae/genética , Animales , Anticuerpos Monoclonales/farmacología , Apolipoproteínas E/fisiología , Aterosclerosis/metabolismo , Células CHO , Arterias Carótidas/metabolismo , Arterias Carótidas/patología , Cricetinae , Cricetulus , Endotelio Vascular/patología , Técnicas de Transferencia de Gen , Proteínas Fluorescentes Verdes , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Activación Plaquetaria , Glicoproteínas de Membrana Plaquetaria/genética , Glicoproteínas de Membrana Plaquetaria/inmunología , Conejos
9.
Gastroenterology ; 137(6): 2063-2073.e4, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19549531

RESUMEN

BACKGROUND & AIMS: Neural stem and progenitor cells from the enteric nervous system have been proposed for use in cell-based therapies against specific neurogastrointestinal disorders. Recently, enteric neural progenitors were generated from human neonatal and early postnatal (until 5 years after birth) gastrointestinal tract tissues. We investigated the proliferation and differentiation of enteric nervous system progenitors isolated from human adult gastrointestinal tract. METHODS: Human enteric spheroids were generated from adult small and large intestine tissues and then expanded and differentiated, depending on the applied cell culture conditions. For implantation studies, spheres were grafted into fetal slice cultures and embryonic aganglionic hindgut explants from mice. Differentiating enteric neural progenitors were characterized by 5-bromo-2-deoxyuridine labeling, in situ hybridization, immunocytochemistry, quantitative real-time polymerase chain reaction, and electrophysiological studies. RESULTS: The yield of human neurosphere-like bodies was increased by culture in conditional medium derived from fetal mouse enteric progenitors. We were able to generate proliferating enterospheres from adult human small or large intestine tissues; these enterospheres could be subcultured and maintained for several weeks in vitro. Spheroid-derived cells could be differentiated into a variety of neuronal subtypes and glial cells with characteristics of the enteric nervous system. Experiments involving implantation into organotypic intestinal cultures showed the differentiation capacity of neural progenitors in a 3-dimensional environment. CONCLUSIONS: It is feasible to isolate and expand enteric progenitor cells from human adult tissue. These findings offer new strategies for enteric stem cell research and future cell-based therapies.


Asunto(s)
Células Madre Adultas/fisiología , Diferenciación Celular , Proliferación Celular , Sistema Nervioso Entérico/fisiología , Intestinos/inervación , Neuroglía/fisiología , Neuronas/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Técnicas de Cocultivo , Medios de Cultivo Condicionados/metabolismo , Embrión de Mamíferos/metabolismo , Sistema Nervioso Entérico/citología , Femenino , Feto/metabolismo , Regulación del Desarrollo de la Expresión Génica , Humanos , Inmunohistoquímica , Hibridación in Situ , Intestinos/embriología , Masculino , Potenciales de la Membrana , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Técnicas de Placa-Clamp , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Esferoides Celulares , Factores de Tiempo , Técnicas de Cultivo de Tejidos
10.
Vet Comp Orthop Traumatol ; 33(4): 274-278, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32349137

RESUMEN

OBJECTIVE: The main purpose of the study was to compare reliability of measurements for the evaluation of hip joint laxity in 59 dogs. MATERIALS AND METHODS: Measurement of the distraction index (DI) of the PennHIP method and the Norberg angle (NA) of the Fédération Cynologique Internationale (FCI) scoring scheme as well as scoring according to the FCI scheme and the Swiss scoring scheme were performed by three observers at different level of experience. For each dog, two radiographs were acquired with each method by the same operator to evaluate intraoperator-reliability. RESULTS: Intraoperator-reliability was slightly better for the NA compared with the DI with an intraclass correlation coefficient (ICC) of 0.962 and 0.892 respectively. The ICC showed excellent results in intraobserver-reliability and interobserver-reliability for both the NA (ICC 0.975; 0.969) and the DI (ICC 0.986; 0.972). Thus, the NA as well as the DI can be considered as reliable measurements. The FCI scheme and the Swiss scoring scheme provide similar reliability. While the FCI scheme seems to be slightly more reliable in experienced observers (Kappa FCI 0.687; Kappa Swiss 0.681), the Swiss scoring scheme had a noticeable better reliability for the unexperienced observer (Kappa FCI 0.465; Kappa Swiss 0.514). CLINICAL SIGNIFICANCE: The Swiss scoring scheme provides a structured guideline for the interpretation of hip radiographs and can thus be recommended to unexperienced observers.


Asunto(s)
Displasia Pélvica Canina/diagnóstico por imagen , Articulación de la Cadera/diagnóstico por imagen , Variaciones Dependientes del Observador , Radiografía/veterinaria , Animales , Perros , Cabeza Femoral/diagnóstico por imagen , Articulación de la Cadera/fisiología , Radiografía/métodos , Reproducibilidad de los Resultados
11.
Food Chem Toxicol ; 138: 111188, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32045649

RESUMEN

Hepatotoxicity is among the most frequent reasons for drug withdrawal from the market. Therefore, there is an urgent need for reliable predictive in vitro tests, which unfailingly identify hepatotoxic drug candidates, reduce drug development time, expenses and the number of test animals. Currently, human hepatocytes represent the gold standard. However, the use of hepatocytes is challenging since the cells are not constantly available and lose their metabolic activity in culture. To solve these problems many different approaches have been developed in the past decades. The aim of this review is to present these approaches and to discuss the possibilities and limitations as well as future opportunities and directions.


Asunto(s)
Técnicas de Cultivo de Célula , Enfermedad Hepática Inducida por Sustancias y Drogas/terapia , Hepatocitos/efectos de los fármacos , Activación Metabólica , Línea Celular , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Técnicas de Cocultivo , Medios de Cultivo/química , Desarrollo de Medicamentos , Hepatocitos/citología , Hepatocitos/metabolismo , Humanos , Fallo Hepático Agudo/complicaciones , Fallo Hepático Agudo/diagnóstico , Modelos Animales , Esferoides Celulares , Andamios del Tejido
12.
Biochem Biophys Res Commun ; 386(1): 232-6, 2009 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-19523443

RESUMEN

Rapamycin is an immunosuppressive drug, which inhibits the mammalian target of rapamycin (mTOR) kinase activity inducing changes in cell proliferation. Synthesis of poly(ADP-ribose) (PAR) is an immediate cellular response to genotoxic stress catalyzed mostly by poly(ADP-ribose) polymerase 1 (PARP-1), which is also controlled by signaling pathways. Therefore, we investigated whether rapamycin affects PAR production. Strikingly, rapamycin inhibited PAR synthesis in living fibroblasts in a dose-dependent manner as monitored by immunofluorescence. PARP-1 activity was then assayed in vitro, revealing that down-regulation of cellular PAR production by rapamycin was apparently not due to competitive PARP-1 inhibition. Further studies showed that rapamycin did not influence the cellular NAD pool and the activation of PARP-1 in extracts of pretreated fibroblasts. Collectively, our data suggest that inhibition of cellular PAR synthesis by rapamycin is mediated by formation of a detergent-sensitive complex in living cells, and that rapamycin may have a potential as therapeutic PARP inhibitor.


Asunto(s)
Inmunosupresores/farmacología , Poli Adenosina Difosfato Ribosa/antagonistas & inhibidores , Sirolimus/farmacología , Células Cultivadas , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Poli Adenosina Difosfato Ribosa/biosíntesis , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Poli(ADP-Ribosa) Polimerasas/metabolismo
13.
Clin Chem ; 55(12): 2113-20, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19850634

RESUMEN

BACKGROUND: Stearoyl-coenzyme A desaturase 1 (SCD1) catalyzes the limiting step of monounsaturated fatty acid synthesis in humans and is an important player in triglyceride generation. SCD1 has been repeatedly implicated in the pathogenesis of metabolic and inflammatory diseases. Therefore it is of great importance to determine SCD1 activity in human samples. In this study we aimed to evaluate a hepatic SCD1 activity index derived from plasma VLDL triglyceride composition as a tool to estimate hepatic SCD1 expression in humans. Additionally, we further evaluated commonly used fatty acid ratios [elongase, de novo lipogenesis, and Delta5 and Delta6 desaturase] in plasma VLDL and hepatic lipid fractions. DESIGN AND METHODS: Liver biopsies and plasma samples were simultaneously collected from 15 individuals. Plasma VLDL was obtained by ultracentrifugation. Hepatic and plasma VLDL lipids were fractionated by thin-layer chromatography, and the fatty acid composition of each fraction was analyzed by gas chromatography. Hepatic SCD1 expression was determined by real-time PCR. RESULTS: Hepatic SCD1 mRNA expression was associated with the product/precursor ratios (16:1/16:0 and 18:1/18:0) of hepatic lipid fractions. The 16:1/16:0 ratio in hepatic and VLDL triglycerides as well as the 18:1/18:0 ratio in plasma VLDL were closely associated with hepatic SCD1 expression. The hepatic de novo lipogenesis index from triglycerides was associated with expression of lipogenic genes [fatty acid synthase (FASN), acetyl-Coenzyme A carboxylase alpha (ACACA), and sterol regulatory element binding transcription factor 1 (SREBP-1)] and is closely reflected by the de novo lipogenesis index in VLDL triglycerides. CONCLUSION: We demonstrated for the first time that hepatic SCD1 expression can be estimated noninvasively from routine blood samples by measuring the SCD1 activity index in fasting plasma VLDL.


Asunto(s)
Ácidos Grasos no Esterificados/química , Lípidos/química , Lipoproteínas VLDL/química , Hígado/metabolismo , ARN Mensajero/biosíntesis , Estearoil-CoA Desaturasa/biosíntesis , Triglicéridos/química , Acetil-CoA Carboxilasa/biosíntesis , Acetiltransferasas/biosíntesis , Acetiltransferasas/genética , Anciano , Cromatografía en Capa Delgada , delta-5 Desaturasa de Ácido Graso , Ácido Graso Desaturasas/biosíntesis , Ácido Graso Desaturasas/genética , Elongasas de Ácidos Grasos , Ácido Graso Sintasas/biosíntesis , Ácidos Grasos no Esterificados/sangre , Femenino , Humanos , Linoleoil-CoA Desaturasa/biosíntesis , Linoleoil-CoA Desaturasa/genética , Lipogénesis , Lipoproteínas VLDL/sangre , Hígado/enzimología , Masculino , Estearoil-CoA Desaturasa/genética , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/biosíntesis , Triglicéridos/sangre
14.
Int J Oncol ; 34(5): 1247-56, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19360338

RESUMEN

Availability of an individualized preselection of oncolytic viruses to be used for virotherapy of tumor patients would be of great help. Using primary liver tumor resection specimens we evaluated the precision-cut liver slice (PCLS) technology as a novel in vitro test system for characterization of paramount tumor infection parameters of individual patients. PCLS slices from resection specimens of 20 liver tumor patients were cultivated in vitro for up to 5 days and infected with 5 different oncolytic measles vaccine virus (MeV) strains. Effectiveness of tumor infection was monitored by viral nucleocapsid (N) protein detection in immunofluorescence staining or Western blot analysis or by detection of GFP marker gene expression. MeV spreading in PCLS cultures was visualized by confocal microscopy. Oncolytic MeV vaccine particles were demonstrated to efficiently infect PCLS slices originating from different primary and secondary tumors of the liver with MeV strains Moraten/Edmonston Zagreb and AIK-C showing highest infection rates (75% of all tested tumor specimens). Employing mixed liver tissue slices (exhibiting both tumorous and non-tumorous tissue areas on one and the same sample) a distinct tumor area favouring pattern of MeV infections was observed being in accordance with our finding that primary human hepatocytes are also permissive to MeV particles, albeit at a much lower rate and with a much less pronounced cytopathic effect. Furthermore, confocal microscopy demonstrated virus penetration throughout tumor tissues into deep cell layers. In conclusion, the PCLS technology is suitable to perform a tumor-patient individualized preselection of oncolytic agents prior to clinical virotherapeutic applications.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/terapia , Hígado/patología , Vacuna Antisarampión/uso terapéutico , Microdisección/métodos , Viroterapia Oncolítica , Animales , Biopsia/métodos , Carcinoma Hepatocelular/patología , Células Cultivadas , Chlorocebus aethiops , Células HT29 , Humanos , Individualidad , Hígado/virología , Neoplasias Hepáticas/patología , Sarampión/patología , Sarampión/virología , Pronóstico , Células Vero
15.
Chem Res Toxicol ; 22(7): 1221-31, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19610676

RESUMEN

For early detection of toxicity and improved mechanistic understanding, GC/MS-, 1H NMR-, and LC/MS-based metabonomics were applied to urine samples from a rodent toxicity study on the mycotoxin and renal carcinogen ochratoxin A (OTA). OTA was administered at doses of 0, 21, 70, and 210 microg/kg body wt for up to 90 days. Urine samples were collected at 24 h intervals 14, 28, and 90 days after the start of treatment and analyzed with GC/MS, 1H NMR, and LC/MS. Principal component analysis and orthogonal projection to latent structures discriminate analysis (OPLS-DA) based on GC/MS and 1H NMR data discriminated controls from animals dosed with 210 microg/kg body wt OTA as early as 14 days and animals dosed with 70 microg/kg body wt 28 days after the start of treatment, correlating with mild histopathological changes in the kidney. Integration of histopathology scores as discriminators in OPLS-DA models resulted in better multivariate model predictivity and facilitated marker identification. Decreased 2-oxoglutarate and citrate excretion and increased glucose, creatinine, pseudouridine, 5-oxoproline, and myo-inositol excretion were detected with GC/MS. Decreased 2-oxoglutarate and citrate excretion and increased amino acid excretion were found with 1H NMR. Increased urinary glucose is a well-established indicator of kidney damage, and altered excretion of TCA cycle intermediates (citrate and 2-oxoglutarate) is found as a general response to toxic insult in many metabonomics studies. Other markers are associated with cell proliferation (pseudouridine), changes in renal osmolyte handling (myo-inositol), and oxidative stress (5-oxoproline), established mechanisms of OTA toxicity. LC/MS was also able to discriminate controls and treated animals but contained more noise, and marker annotation was only speculative due to lack of reference databases. Use of multiple analytical platforms for metabonomics analysis may result in a more comprehensive metabolite coverage and may be applied to obtain mechanistic information from conventional rodent toxicity studies.


Asunto(s)
Biomarcadores/orina , Carcinógenos/toxicidad , Metabolómica/métodos , Ocratoxinas/toxicidad , Pruebas de Toxicidad , Animales , Biomarcadores/química , Carcinógenos/administración & dosificación , Carcinógenos/metabolismo , Cromatografía Líquida de Alta Presión , Interpretación Estadística de Datos , Cromatografía de Gases y Espectrometría de Masas , Riñón/patología , Espectroscopía de Resonancia Magnética , Masculino , Espectrometría de Masas , Ocratoxinas/administración & dosificación , Ocratoxinas/metabolismo , Fenotipo , Ratas
16.
Front Immunol ; 10: 2526, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31803175

RESUMEN

Background: Radiofrequency ablation (RFA) is an established treatment option for malignancies located in the liver. RFA-induced irreversible coagulation necrosis leads to the release of danger signals and cellular content. Hence, RFA may constitute an endogenous in situ tumor vaccination, stimulating innate and adaptive immune responses, including tumor-antigen specific T cells. This may explain a phenomenon termed abscopal effect, namely tumor regression in untreated lesions evidenced after distant thermal ablation or irradiation. In this study, we therefore assessed systemic and local immune responses in individual patients treated with RFA. Methods: For this prospective clinical trial, patients with liver metastasis from colorectal carcinoma (mCRC) receiving RFA and undergoing metachronous liver surgery for another lesion were recruited (n = 9) during a 5-year period. Tumor and non-malignant liver tissue samples from six patients were investigated by whole transcriptome sequencing and tandem-mass spectrometry, characterizing naturally presented HLA ligands. Tumor antigen-derived HLA-restricted peptides were selected by different predefined approaches. Further, candidate HLA ligands were manually curated. Peripheral blood mononuclear cells were stimulated in vitro with epitope candidate peptides, and functional T cell responses were assessed by intracellular cytokine staining. Immunohistochemical markers were additionally investigated in surgically resected mCRC from patients treated with (n = 9) or without RFA (n = 7). Results: In all six investigated patients, either induced immune responses and/or pre-existing T cell immunity against the selected targets were observed. Multi-cytokine responses were inter alia directed against known tumor antigens such as cyclin D1 but also against a (predicted) mutation contained in ERBB3. Immunohistochemistry did not show a relevant influx of immune cells into distant malignant lesions after RFA treatment (n = 9) as compared to the surgery only mCRC group (n = 7). Conclusions: Using an individualized approach for target selection, RFA induced and/or boosted T cell responses specific for individual tumor antigens were more frequently detectable as compared to previously published observations with well-characterized tumor antigens. However, the witnessed modest RFA-induced immunological effects alone may not be sufficient for the rejection of established tumors. Therefore, these findings warrant further clinical investigation including the assessment of RFA combination therapies e.g., with immune stimulatory agents, cancer vaccination, and/or immune checkpoint inhibitors.


Asunto(s)
Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/patología , Inmunidad , Neoplasias Hepáticas/inmunología , Neoplasias Hepáticas/secundario , Anciano , Ablación por Catéter/métodos , Cromatografía Liquida , Biología Computacional , Femenino , Perfilación de la Expresión Génica , Antígenos HLA/inmunología , Antígenos HLA/metabolismo , Humanos , Inmunidad/genética , Inmunofenotipificación , Ligandos , Neoplasias Hepáticas/cirugía , Masculino , Inestabilidad de Microsatélites , Persona de Mediana Edad , Proteómica/métodos , Linfocitos T/inmunología , Linfocitos T/metabolismo , Espectrometría de Masas en Tándem , Resultado del Tratamiento , Secuenciación del Exoma
17.
J Nutr ; 138(8): 1452-5, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18641190

RESUMEN

Results of animal experiments suggest that consumption of refined carbohydrates (e.g. fructose) can result in small intestinal bacterial overgrowth and increased intestinal permeability, thereby contributing to the development of nonalcoholic fatty liver disease (NAFLD). Furthermore, increased plasminogen activator inhibitor (PAI)-1 has been linked to liver damage of various etiologies (e.g. alcohol, endotoxin, nonalcoholic). The aim of the present pilot study was to compare dietary factors, endotoxin, and PAI-1 concentrations between NAFLD patients and controls. We assessed the dietary intake of 12 patients with NAFLD and 6 control subjects. Plasma endotoxin and PAI-1 concentrations as well as hepatic expression of PAI-1 and toll-like receptor (TLR) 4 mRNA were determined. Despite similar total energy, fat, protein, and carbohydrate intakes, patients with NAFLD consumed significantly more fructose than controls. Endotoxin and PAI-1 plasma concentrations as well as hepatic TLR4 and PAI-1 mRNA expression of NAFLD patients were significantly higher than in controls. The plasma PAI-1 concentration was positively correlated with the plasma endotoxin concentration (Spearman r = 0.83; P < 0.005) and hepatic TLR4 mRNA expression (Spearman r = 0.54; P < 0.05). Hepatic mRNA expression of PAI-1 was positively associated with dietary intakes of carbohydrates (Spearman r = 0.67; P < 0.01), glucose (Spearman r = 0.58; P < 0.01), fructose (Spearman r = 0.58; P < 0.01), and sucrose (Spearman r = 0.70; P < 0.01). In conclusion, our results suggest that dietary fructose intake, increased intestinal translocation of bacterial endotoxin, and PAI-1 may contribute to the development of NAFLD in humans.


Asunto(s)
Endotoxinas/sangre , Hígado Graso/inducido químicamente , Hígado Graso/metabolismo , Fructosa/efectos adversos , Inhibidor 1 de Activador Plasminogénico/sangre , Adulto , Estudios de Casos y Controles , Dieta , Carbohidratos de la Dieta/administración & dosificación , Carbohidratos de la Dieta/efectos adversos , Relación Dosis-Respuesta a Droga , Hígado Graso/sangre , Femenino , Fructosa/administración & dosificación , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Hígado/metabolismo , Masculino , Persona de Mediana Edad , Proyectos Piloto , Inhibidor 1 de Activador Plasminogénico/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptor Toll-Like 4/sangre , Receptor Toll-Like 4/genética
18.
Sci Rep ; 8(1): 6974, 2018 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-29725116

RESUMEN

Donor organ quality affects long term outcome after renal transplantation. A variety of prognostic molecular markers is available, yet their validity often remains undetermined. A network-based molecular model reflecting donor kidney status based on transcriptomics data and molecular features reported in scientific literature to be associated with chronic allograft nephropathy was created. Significantly enriched biological processes were identified and representative markers were selected. An independent kidney pre-implantation transcriptomics dataset of 76 organs was used to predict estimated glomerular filtration rate (eGFR) values twelve months after transplantation using available clinical data and marker expression values. The best-performing regression model solely based on the clinical parameters donor age, donor gender, and recipient gender explained 17% of variance in post-transplant eGFR values. The five molecular markers EGF, CD2BP2, RALBP1, SF3B1, and DDX19B representing key molecular processes of the constructed renal donor organ status molecular model in addition to the clinical parameters significantly improved model performance (p-value = 0.0007) explaining around 33% of the variability of eGFR values twelve months after transplantation. Collectively, molecular markers reflecting donor organ status significantly add to prediction of post-transplant renal function when added to the clinical parameters donor age and gender.


Asunto(s)
Supervivencia de Injerto , Trasplante de Riñón , Riñón/fisiología , Biología de Sistemas/métodos , Factores de Edad , Biomarcadores/análisis , Femenino , Tasa de Filtración Glomerular , Rechazo de Injerto/etiología , Humanos , Modelos Lineales , Masculino , Modelos Biológicos , Medición de Riesgo , Factores de Riesgo , Factores Sexuales , Donantes de Tejidos , Transcriptoma
19.
Cancer Res ; 78(16): 4627-4641, 2018 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-29789417

RESUMEN

Immune cell infiltrates have proven highly relevant for colorectal carcinoma prognosis, making colorectal cancer a promising candidate for immunotherapy. Because tumors interact with the immune system via HLA-presented peptide ligands, exact knowledge of the peptidome constitution is fundamental for understanding this relationship. Here, we comprehensively describe the naturally presented HLA ligandome of colorectal carcinoma and corresponding nonmalignant colon (NMC) tissue. Mass spectrometry identified 35,367 and 28,132 HLA class I ligands on colorectal carcinoma and NMC, attributable to 7,684 and 6,312 distinct source proteins, respectively. Cancer-exclusive peptides were assessed on source protein level using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein analysis through evolutionary relationships (PANTHER), revealing pathognomonic colorectal carcinoma-associated pathways, including Wnt, TGFß, PI3K, p53, and RTK-RAS. Relative quantitation of peptide presentation on paired colorectal carcinoma and NMC tissue further identified source proteins from cancer- and infection-associated pathways to be overrepresented merely within the colorectal carcinoma ligandome. From the pool of tumor-exclusive peptides, a selected HLA-ligand subset was assessed for immunogenicity, with the majority exhibiting an existing T-cell repertoire. Overall, these data show that the HLA ligandome reflects cancer-associated pathways implicated in colorectal carcinoma oncogenesis, suggesting that alterations in tumor cell metabolism could result in cancer-specific, albeit not mutation-derived, tumor antigens. Hence, a defined pool of unique tumor peptides, attributable to complex cellular alterations that are exclusive to malignant cells, might comprise promising candidates for immunotherapeutic applications.Significance: Cancer-associated pathways are reflected in the antigenic landscape of colorectal cancer, suggesting that tumor-specific antigens do not necessarily have to be mutation-derived but may also originate from other alterations in cancer cells. Cancer Res; 78(16); 4627-41. ©2018 AACR.


Asunto(s)
Transformación Celular Neoplásica/genética , Neoplasias Colorrectales/genética , Antígenos HLA/genética , Inmunoterapia , Secuencia de Aminoácidos/genética , Presentación de Antígeno/inmunología , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/inmunología , Transformación Celular Neoplásica/inmunología , Neoplasias Colorrectales/inmunología , Humanos , Ligandos , Espectrometría de Masas , Péptidos/genética , Péptidos/inmunología , Linfocitos T/inmunología , Linfocitos T/patología
20.
J Clin Endocrinol Metab ; 103(12): 4373-4383, 2018 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-30202879

RESUMEN

Context: Reduced ß-cell mass, impaired islet function, and dedifferentiation are considered causal to development of hyperglycemia and type 2 diabetes. In human cohort studies, changes of islet cell-specific expression patterns have been associated with diabetes but not directly with in vivo insulin secretion. Objective: This study investigates alterations of islet gene expression and corresponding gene variants in the context of in vivo glycemic traits from the same patients. Methods: Fasting blood was collected before surgery, and pancreatic tissue was frozen after resection from 18 patients undergoing pancreatectomy. Islet tissue was isolated by laser capture microdissection. Islet transcriptome was analyzed using microarray and quantitative RT-PCR. Proteins were examined by immunohistochemistry and western blotting. The association of gene variants with insulin secretion was investigated with oral glucose tolerance test (OGTT)-derived insulin secretion measured in a large cohort of subjects at increased risk of type 2 diabetes and with hyperglycemic clamp in a subset. Results: Differential gene expression between islets from normoglycemic and hyperglycemic patients was prominent for the glycolytic enzyme ALDOB and the obesity-associated gene FAIM2. The mRNA levels of both genes correlated negatively with insulin secretion and positively with HbA1c. Islets of hyperglycemic patients displayed increased ALDOB immunoreactivity in insulin-positive cells, whereas α- and δ-cells were negative. Exposure of isolated islets to hyperglycemia augmented ALDOB expression. The minor allele of the ALDOB variant rs550915 associated with significantly higher levels of C-peptide and insulin during OGTT and hyperglycemic clamp, respectively. Conclusion: Our analyses suggest that increased ALDOB expression in human islets is associated with lower insulin secretion.


Asunto(s)
Diabetes Mellitus Tipo 2/metabolismo , Fructosa-Bifosfato Aldolasa/metabolismo , Hiperglucemia/metabolismo , Secreción de Insulina/fisiología , Islotes Pancreáticos/metabolismo , Glucemia , Células Cultivadas , Estudios Transversales , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/genética , Fructosa-Bifosfato Aldolasa/genética , Perfilación de la Expresión Génica , Técnica de Clampeo de la Glucosa , Prueba de Tolerancia a la Glucosa , Hemoglobina Glucada/análisis , Voluntarios Sanos , Humanos , Hiperglucemia/sangre , Hiperglucemia/genética , Insulina/sangre , Captura por Microdisección con Láser , Pancreatectomía , Neoplasias Pancreáticas/cirugía , Polimorfismo de Nucleótido Simple , Cultivo Primario de Células
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA