Depósito Académico
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- Factors related to increased resting energy expenditure in men with liver cirrhosis(2016) Prieto-Frías, C. (Cesár); Conchillo, M. (M.); Payeras, M. (Marina); Iñarrairaegui, M. (Mercedes); D'Avola, D. (Delia); Frühbeck, G. (Gema); Salvador, J. (Javier); Rodriguez, M. (Macarena); Richter, J.A. (José Ángel); Mugueta, C. (Carmen); Gil-Maria, J. (Jesús); Herrero, I. (Ignacio); Prieto, J. (Jesús); Sangro, B. (Bruno); Quiroga, J. (Jorge)Objective Hypermetabolism in cirrhosis is associated with a high risk of complications and mortality. However, studies about underlying mechanisms are usually focussed on isolated potential determinants and specific etiologies, with contradictory results. We aimed at investigating differences in nutrition, metabolic hormones, and hepatic function between hypermetabolic and nonhypermetabolic men with cirrhosis of the liver. Patients and methods We prospectively enrolled 48 male cirrhotic inpatients. We evaluated their resting energy expenditure (REE) and substrate utilization by indirect calorimetry, body composition by dual-energy X-ray absorptiometry, liver function, and levels of major hormones involved in energy metabolism by serum sample tests. Patients with ascites, specific metabolic disturbances, and hepatocellular carcinoma were excluded. Results REE and REE adjusted per fat-free mass (FFM) were significantly increased in cirrhotic patients. Overall, 58.3% of cirrhotic patients were classified as hypermetabolic. Groups did not differ significantly in age, etiology of cirrhosis, liver function, presence of ascites, use of diuretics, β-blockers, or presence of transjugular intrahepatic portosystemic shunts. Hypermetabolic cirrhotic patients had lower weight, BMI (P< 0.05), nonprotein respiratory quotient (P< 0.01), leptin (P<0.05), and leptin adjusted per fat mass (FM) (P<0.05), but higher FFM% (P< 0.05) and insulin resistance [homeostatic model assessment-insulin resistance (HOMA-IR)] (P<0.05). Only HOMA-IR, leptin/FM, and FFM% were independently related to the presence of hypermetabolism. Conclusion Hypermetabolic cirrhotic men are characterized by lower weight, higher FFM%, insulin resistance, and lower leptin/FM when compared with nonhypermetabolic men. HOMA-IR, FFM%, and leptin/FM were independently associated with hypermetabolism, and may serve as easily detectable markers of this condition in daily clinical practice
- Inhibition of FOXP3/NFAT Interaction Enhances T Cell Function after TCR Stimulation(American Association of Immunologists, 2015) Riezu-Boj, J.I. (José Ignacio); Lozano-Moreda, T. (Teresa); Ruiz, M. (Marta); Coffer, P.J. (Paul J.); Oyarzabal, J. (Julen); Lourenço, A.R. (Ana R.); Hervas-Stubbs, S. (Sandra); Durantez, M. (Maika); Casares, N. (Noelia); Bandukwala, H. (Hozefa); Prieto, J. (Jesús); Sarobe, P. (Pablo); Villanueva, L. (Lorea); Gorraiz, M. (Marta); Belsue, V. (Virginia); Lasarte, J.J. (Juan José)Regulatory T cell (Treg) activity is modulated by a cooperative complex between the transcription factor NFAT and FOXP3, a lineage specification factor for Tregs. FOXP3/NFAT interaction is required to repress expression of IL-2, upregulate expression of the Treg markers CTLA4 and CD25, and confer suppressor function to Tregs. However, FOXP3 is expressed transiently in conventional CD4(+) T cells upon TCR stimulation and may lead to T cell hyporesponsiveness. We found that a short synthetic peptide able to inhibit FOXP3/NFAT interaction impaired suppressor activity of conventional Tregs in vitro. Specific inhibition of FOXP3/NFAT interaction with this inhibitory peptide revealed that FOXP3 downregulates NFAT-driven promoter activity of CD40L and IL-17. Inhibition of FOXP3/NFAT interaction upregulated CD40L expression on effector T cells and enhanced T cell proliferation and IL-2, IFN-γ, IL-6, or IL-17 production in response to TCR stimulation. The inhibitory peptide impaired effector T cell conversion into induced Tregs in the presence of TGF-β. Moreover, in vivo peptide administration showed antitumor efficacy in mice bearing Hepa129 or TC1 tumor cells when combined with sorafenib or with an antitumor vaccine, respectively. Our results suggest that inhibition of NFAT/FOXP3 interaction might improve antitumor immunotherapies.
- Helper cell-independent antitumor activity of potent CD8+ T cell epitope peptide vaccines is dependent upon CD40L(Taylor & Francis, 2013) Zabaleta, A. (Aintzane); Borras-Cuesta, F. (Francisco); Ruiz, M. (Marta); Prieto, J. (Jesús); Huarte, E. (Eduardo); Bezunartea, J. (Jaione); Llopiz, D. (Diana); Sarobe, P. (Pablo); Belsue, V. (Virginia); Lasarte, J.J. (Juan José)Peptide vaccines derived from CD8+ T-cell epitopes have shown variable efficacy in cancer patients. Thus, some peptide vaccines are capable of activating CD8+ T-cell responses, even in the absence of CD4+ T-cell epitopes or dendritic cell (DC)-activating adjuvants. However, the mechanisms underlying the clinical activity of these potent peptides are poorly understood. Using CT26 and ovalbumin-expressing B16 murine allograft tumor models, we found that the antitumor effect of helper cell-independent CD8 T-cell peptide vaccines is inhibited by the blockade of CD40 ligand (CD40L) in vivo. Furthermore, in vitro stimulation with antigenic peptides of cells derived from immunized mice induced the expression of CD40L on the surface of CD8+ T cells and fostered DC maturation, an effect that was partially inhibited by CD40L-blocking antibodies. Interestingly, CD40L blockade also inhibited CD8+ T-cell responses, even in the presence of fully mature DCs, suggesting a role for CD40L not only in promoting DC maturation but also in mediating CD8+ T-cell co-stimulation. Importantly, these potent peptides share features with bona fide CD4 epitopes, since they foster responses against less immunogenic CD8+ T-cell epitopes in a CD40L-dependent manner. The analysis of peptides used for the vaccination of cancer patients in clinical trials showed that these peptides also induce the expression of CD40L on the surface of CD8+ T cells. Taken together, these results suggest that CD40L expression induced by potent CD8+ T-cell epitopes can activate antitumor CD8+ T-cell responses, potentially amplifying the immunological responses to less immunogenic CD8+ T-cell epitopes and bypassing the requirement for CD4+ helper T cells in vaccination protocols.
- Brain ventricular enlargement in human and murine acute intermittent porphyria(2020) González-Aseguinolaza, G. (Gloria); D'Avola, D. (Delia); Benito, M. (Marina); Lanciego, J.L. (José Luis); Desco, M. (Manuel); Luis, E. (Elkin); Ortiz-de-Solorzano, C. (Carlos); Córdoba, K.M. (Karol M.); Fernández-Seara, M.A. (María A.); Pastor, M.A. (María A.); Larriva-Hormigos, M. (María); Prieto, J. (Jesús); Enriquez-de-Salamanca, R. (Rafael); Fontanellas-Romá, A. (Antonio); Morales-Urteaga, X. (Xabier); Cussó, L. (Lorena); Alegre-Esteban, M. (Manuel); Sampedro, A. (Ana); Jericó-Asenjo, D. (Daniel)The morphological changes that occur in the central nervous system of patients with severe acute intermittent porphyria (AIP) have not yet been clearly established. The aim of this work was to analyze brain involvement in patients with severe AIP without epileptic seizures or clinical posterior reversible encephalopathy syndrome, as well as in a mouse model receiving or not liver-directed gene therapy aimed at correcting the metabolic disorder. We conducted neuroradiologic studies in 8 severely affected patients (6 women) and 16 gender- and age-matched controls. Seven patients showed significant enlargement of the cerebral ventricles and decreased brain perfusion was observed during the acute attack in two patients in whom perfusion imaging data were acquired. AIP mice exhibited reduced cerebral blood flow and developed chronic dilatation of the cerebral ventricles even in the presence of slightly increased porphyrin precursors. While repeated phenobarbital-induced attacks exacerbated ventricular dilation in AIP mice, correction of the metabolic defect using liver-directed gene therapy restored brain perfusion and afforded protection against ventricular enlargement. Histological studies revealed no signs of neuronal loss but a denser neurofilament pattern in the periventricular areas, suggesting compression probably caused by imbalance in cerebrospinal fluid dynamics. In conclusion, severely affected AIP patients exhibit cerebral ventricular enlargement. Liver-directed gene therapy protected against the morphological consequences of the disease seen in the brain of AIP mice.
- Recombinant porphobilinogen deaminase targeted to the liver corrects enzymopenia in a mouse model of acute intermittent porphyria(2022) Berraondo, P. (Pedro); Corrales, F.J. (Fernando José); Martini, P. (Paolo); Lanciego, J.L. (José Luis); Córdoba-Quiñones, K. M. (Karol Marcela); Serrano-Mendioroz, I. (Irantzu); Prieto, J. (Jesús); Fontanellas-Romá, A. (Antonio); Merino-Díaz, M. (María); Garrido, M.J. (María Jesús); Alegre-Esteban, M. (Manuel); Sampedro, A. (Ana); Jericó-Asenjo, D. (Daniel); Jiang, L. (Lei)Correction of enzymatic deficits in hepatocytes by systemic administration of a recombinant protein is a desired therapeutic goal for hepatic enzymopenic disorders such as acute intermittent porphyria (AIP), an inherited porphobilinogen deaminase (PBGD) deficiency. Apolipoprotein A-I (ApoAI) is internalized into hepatocytes during the centripetal transport of cholesterol. Here, we generated a recombinant protein formed by linking ApoAI to the amino terminus of human PBGD (rhApoAI-PBGD) in an attempt to transfer PBGD into liver cells. In vivo experiments showed that, after intravenous injection, rhApoAI-PBGD circulates in blood incorporated into high-density lipoprotein (HDL), penetrates into hepatocytes, and crosses the blood-brain barrier, increasing PBGD activity in both the liver and brain. Consistently, the intravenous administration of rhApoAI-PBGD or the hyperfunctional rApoAI-PBGD-I129M/N340S (rApoAI-PBGDms) variant efficiently prevented and abrogated phenobarbital-induced acute attacks in a mouse model of AIP. One month after a single intravenous dose of rApoAI-PBGDms, the protein was still detectable in the liver, and hepatic PBGD activity remained increased above control values. A long-lasting therapeutic effect of rApoAI-PBGDms was observed after either intravenous or subcutaneous administration. These data describe a method to deliver PBGD to hepatocytes with resulting enhanced hepatic enzymatic activity and protection against AIP attacks in rodent models, suggesting that the approach might be an effective therapy for AIP.
- Identifying Differentially Expressed MicroRNAs, Target Genes, and Key Pathways Deregulated in Patients with Liver Diseases(2020) Post, M. (Mariola); Kurzawski, M. (Mateusz); Prieto, J. (Jesús); Kaderali, L. (Lars); Gholizadeh, M. (Maryam); Argemí, J. (Josepmaria); Szelag-Pieniek, S. (Sylwia); Drozdzik, M. (Marek)Liver diseases are important causes of morbidity and mortality worldwide. The aim of this study was to identify differentially expressed microRNAs (miRNAs), target genes, and key pathways as innovative diagnostic biomarkers in liver patients with different pathology and functional state. We determined, using RT-qPCR, the expression of 472 miRNAs in 125 explanted livers from subjects with six different liver pathologies and from control livers. ANOVA was employed to obtain differentially expressed miRNAs (DEMs), and miRDB (MicroRNA target prediction database) was used to predict target genes. A miRNA–gene differential regulatory (MGDR) network was constructed for each condition. Key miRNAs were detected using topological analysis. Enrichment analysis for DEMs was performed using the Database for Annotation, Visualization, and Integrated Discovery (DAVID). We identified important DEMs common and specific to the different patient groups and disease progression stages. hsa-miR-1275 was universally downregulated regardless the disease etiology and stage, while hsa-let-7a*, hsa-miR-195, hsa-miR-374, and hsa-miR-378 were deregulated. The most significantly enriched pathways of target genes controlled by these miRNAs comprise p53 tumor suppressor protein (TP53)-regulated metabolic genes, and those involved in regulation of methyl-CpG-binding protein 2 (MECP2) expression, phosphatase and tensin homolog (PTEN) messenger RNA (mRNA) translation and copper homeostasis. Our findings show a novel panel of deregulated miRNAs in the liver tissue from patients with different liver pathologies. These miRNAs hold potential as biomarkers for diagnosis and staging of liver diseases.
- Application of a split-Cre system for high-capacity adenoviral vector amplification(Wiley, 2023) Prieto, J. (Jesús); Ortiz-de-Landazuri, I. (Iñaki); Hernandez-Alcoceba, R. (Rubén); Buñuales, M. (María); Gonzalez-Aparicio, M. (Manuela)Background and aims: High-capacity adenoviral vectors (HC-AdV) show extended DNA payload and stability of gene expression in vivo due to the absence of viral coding sequences. However, production requires methods to trans-complement viral proteins, usually through Helper Viruses (HV). The Cre/loxP system is frequently employed to remove the packaging signal in HV genomes, in order to avoid their encapsidation. However, chronic exposure to the Cre recombinase in packaging cells is detrimental. We have applied the dimerizable Cre system to overcome this limitation. Methods and results: Cre was split in two fragments devoid of recombinase function (N-terminal 244 and C-terminal 99 amino-acids). In one version of the system, interaction with both moieties was favored by rapamycin-dependent heterodimerization domains (DiCre). Other version contained only Cre sequences (oCre). We generated packaging cells and HVs expressing the complementary fragments and studied their performance for HC-AdV production. We found that both conformations avoided interference with the growth of packaging cells, and the oCre system was particularly suitable for HC-AdV amplification. Conclusions: The split-Cre system improves the performance of packaging cells and can reduce the time and cost of HC-AdV amplification up to 30% and 15%, respectively. This may contribute to the standardization of HC-AdV production.
- TMEM173 alternative spliced isoforms modulate viral replication through STING pathway(American Association of Immunologists, 2018) Rodríguez-García, E. (Estefanía); Ferrero, R. (Roberto); González-Aseguinolaza, G. (Gloria); Ríus-Rocabert, S. (Sergio); Olagüe, C. (Cristina); Larrea, E. (Esther); Nistal-Villan, E. (Estanislao); Prieto, J. (Jesús); Fortes, P. (Puri); Llorens, C. (Carles)The innate immune system provides a primary line of defense against pathogens. Stimulator of IFN genes (STING), encoded by the TMEM173 gene, is a critical protein involved in IFN-b induction in response to infection by different pathogens. In this study, we describe the expression of three different alternative-spliced human (h) TMEM173 mRNAs producing STING truncated isoforms 1, 2, and 3 in addition to the full-length wild-type (wt) hSTING. All of the truncated isoforms lack exon 7 and share the N-terminal transmembrane region with wt hSTING. Overexpression of the three STING truncated isoforms failed to induce IFN-b, and they acted as selective pathway inhibitors of wt hSTING even in combination with upstream inducer cyclic-di-GMP-AMP synthase. Truncated isoforms alter the stability of wt hSTING, reducing protein t1/2 to some extent by the induction of proteasome-dependent degradation. Knocking down expression of truncated isoforms increased production of IFN-b by THP1 monocytes in response to intracellular cytosolic DNA or HSV-1 infection. At early stages of infection, viruses like HSV-1 or vesicular stomatitis virus reduced the ratio of full-length wt hSTING/truncated STING isoforms, suggesting the skewing of alternative splicing of STING toward truncated forms as a tactic to evade antiviral responses. Finally, in silico analysis revealed that the human intron–exon gene architecture of TMEM173 (splice sites included) is preserved in other mammal species, predominantly primates, stressing the relevance of alternative splicing in regulating STING antiviral biology.
- The cirrhotic liver is depleted of docosahexaenoic acid (DHA), a key modulator of NF-κB and TGFβ pathways in hepatic stellate cells(Springer Science and Business Media LLC, 2019) Enguita, M. (Mónica); Prieto, J. (Jesús); Razquin, N. (Nerea); Pamplona, R. (Reinald); Fortes, P. (Puri); Quiroga, J. (Jorge)Liver cirrhosis results from chronic hepatic damage and is characterized by derangement of the organ architecture with increased liver fibrogenesis and defective hepatocellular function. It frequently evolves into progressive hepatic insufficiency associated with high mortality unless liver transplantation is performed. We have hypothesized that the deficiency of critical nutrients such as essential omega-3 fatty acids might play a role in the progression of liver cirrhosis. Here we evaluated by LC-MS/MS the liver content of omega-3 docosahexaenoic fatty acid (DHA) in cirrhotic patients and investigated the effect of DHA in a murine model of liver injury and in the response of hepatic stellate cells (HSCs) (the main producers of collagen in the liver) to pro-fibrogenic stimuli. We found that cirrhotic livers exhibit a marked depletion of DHA and that this alteration correlates with the progression of the disease. Administration of DHA exerts potent anti-fibrogenic effects in an acute model of liver damage. Studies with HSCs show that DHA inhibits fibrogenesis more intensely than other omega-3 fatty acids. Data from expression arrays revealed that DHA blocks TGFβ and NF-κB pathways. Mechanistically, DHA decreases late, but not early, SMAD3 nuclear accumulation and inhibits p65/RelA-S536 phosphorylation, which is required for HSC survival. Notably, DHA increases ADRP expression, leading to the formation of typical quiescence-associated perinuclear lipid droplets. In conclusion, a marked depletion of DHA is present in the liver of patients with advanced cirrhosis. DHA displays anti-fibrogenic activities on HSCs targeting NF-κB and TGFβ pathways and inducing ADPR expression and quiescence in these cells.
- Promoter hypermethylation of the AE2/SLC4A2 gene in PBC(Elsevier, 2019) Medina, J.F. (Juan Francisco); Saez, E. (Elena); Melero, S. (Saida); Prieto, J. (Jesús); Arenas, F. (Fabián); Parés, A. (Albert); Hervias, I. (Isabel)Primary biliary cholangitis (PBC) is a chronic immuneassociated cholestatic liver disease with unclear complex/multifactorial etiopathogenesis affecting mostly middle-aged women. Patients with PBC exhibit reduced expression of the AE2/SLC4A2 gene. Herein, we found that AE2 promoter regions are hypermethylated in the liver and peripheral blood mononuclear cells of patients with PBC. This increased methylation is associated with downregulated AE2-gene expression, which might contribute to the pathogenesis of PBC. Therefore, novel epigenetic targets may improve treatment in patients with PBC who respond poorly to current pharmacological therapies.