Person: Cubero Palero, Francisco Javier
Loading...
First Name
Francisco Javier
Last Name
Cubero Palero
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Medicina
Department
Inmunología, Oftalmología y ORL
Area
Identifiers
5 results
Search Results
Now showing 1 - 5 of 5
Item Ethanol and Arachidonic Acid Synergize to Activate Kupffer Cells and Modulate the Fibrogenic Response via Tumor Necrosis Factor , Reduced Glutathione, and Transforming Growth Factor beta–Dependent Mechanisms(Hepatology., 2008) Cubero Palero, Francisco Javier; Nieto, NataliaBecause of the contribution of ethanol and polyunsaturated fatty acids (PUFAs) to alcoholic liver disease, we investigated whether chronic ethanol administration and arachidonic acid (AA) could synergistically mediate Kupffer cell (KC) activation and modulate the stellate cell (HSC) fibrogenic response. Results: (1) the effects of ethanol and AA on KC and HSC were as follows: Cell proliferation, lipid peroxidation, H(2)O(2), O(2).(-), nicotinamide adenine dinucleotide phosphate reduced form (NADPH) oxidase activity, and tumor necrosis factor alpha (TNF-alpha) were higher in KC(ethanol) than in KC(control), and were enhanced by AA; HSC(ethanol) proliferated faster, increased collagen, and showed higher GSH than HSC(control), with modest effects by AA. (2) AA effects on the control co-culture: We previously reported the ability of KC to induce a pro-fibrogenic response in HSC via reactive oxygen species (ROS)-dependent mechanisms; we now show that AA further increases cell proliferation and collagen in the control co-culture. The latter was prevented by vitamin E (an antioxidant) and by diphenyleneiodonium (a NADPH oxidase inhibitor). (3) Ethanol effects on the co-cultures: Co-culture with KC(control) or KC(ethanol) induced HSC(control) and HSC(ethanol) proliferation; however, the pro-fibrogenic response in HSC(ethanol) was suppressed because of up-regulation of TNF-alpha and GSH, which was prevented by a TNF-alpha neutralizing antibody (Ab) and by L-buthionine-sulfoximine, a GSH-depleting agent. (4) Ethanol plus AA effects on the co-cultures: AA lowered TNF-alpha in the HSC(control) co-cultures, allowing for enhanced collagen deposition; furthermore, AA restored the pro-fibrogenic response in the HSC(ethanol) co-cultures by counteracting the up-regulation of TNF-alpha and GSH with a significant increase in GSSG and in pro-fibrogenic transforming growth factor beta (TGF-beta). Conclusion: These results unveil synergism between ethanol and AA to the mechanism whereby KC mediate ECM remodeling and suggest that even if chronic ethanol consumption sensitizes HSC to up-regulate anti-fibrogenic signals, their effects are blunted by a second "hit" such as AA.Item Hepatic overexpression of cAMP-responsive element modulator α induces a regulatory T-cell response in a murine model of chronic liver disease(Hepathology, 2016) Cubero Palero, Francisco Javier; Kuttkat, Nadine; Mohs, Antje; Ohl, Kim; Hooiveld, Guido; Longerich, Thomas; Tenbrock, Klaus; Trautwein, ChristianObjective: Th17 cells are a subset of CD4+ T-helper cells characterised by interleukin 17 (IL-17) production, a cytokine that plays a crucial role in inflammationassociated diseases. The cyclic AMP-responsive element modulator-α (CREMα) is a central mediator of T-cell pathogenesis, which contributes to increased IL-17 expression in patients with autoimmune disorders. Since an increased Th17 response is associated with a poor prognosis in patients with chronic liver injury, we investigated the relevance of Th17 cells for chronic liver disease (CLD) and hepatocarcinogenesis. Design: Transgenic mice overexpressing CREMα were crossed with hepatocyte-specific Nemo knockout mice (NemoΔhepa) to generate NemoΔhepa/CREMαTg mice. The impact of CREMαTg on CLD progression was examined. Additionally, soft agar colony formation assays, in vitro studies, adoptive transfer of bone marrow-derived cells (BMDCs) and T cells, and gene arrays in T cells were performed. Results: 8-week-old NemoΔhepa/CREMαTg mice presented significantly decreased transaminase levels, concomitant with reduced numbers of CD11b+ dendritic cells and CD8+ T cells. CREMαTg overexpression in NemoΔhepa mice was associated with significantly reduced hepatic fibrogenesis and carcinogenesis at 52 weeks. Interestingly, hepatic stellate cell-derived retinoic acid induced a regulatory T-cell (Treg) phenotype in CREMαTg hepatic T cells. Moreover, simultaneous adoptive transfer of BMDCs and T cells from CREMαTg into NemoΔhepa mice ameliorated markers of liver injury and hepatitis. Conclusions: Our results demonstrate that overexpression of CREMα in T cells changes the inflammatory milieu, attenuating initiation and progression of CLD. Unexpectedly, our study indicates that CREMα transgenic T cells shift chronic inflammation in NemoΔhepa livers towards a protective Treg response.Item Oxidative stress modulates KLF6Full and its splice variants(Alcoholism: Clinical and Experimental Research, 2012) Urtasun, Raquel; Cubero Palero, Francisco Javier; Nieto, NataliaAbstract Background: Induction of reactive oxygen species (ROS) is a central mechanism in alcohol hepatotoxicity. Krüppel-like factor 6 (KLF6), a transcription factor and a tumor-suppressor gene, is an early-responsive gene to injury; however, the effect of ROS and alcohol on KLF6 induction is unknown. The aim of this study is to investigate the contribution of 2 sources of ROS, cytochrome P450 2E1 (CYP2E1), NAD(P)H quinone oxidoreductase (NQO1), and alcohol on the modulation of KLF6(Full) expression, splicing to KLF6_V1 and KLF6_V2, and the effect on TNFα, a downstream target. Methods and results: Endogenous ROS production in CYP2E1-expressing HepG2 cells induced mRNA and protein expression of KLF6(Full) and its splice variants compared to control cells. Incubation with pro-oxidants such as arachidonic acid (AA), β-naphtoflavone, and H(2) O(2) further enhanced KLF6(Full) and its splice variants. The AA effects on KLF6(Full) and its splice forms were blocked by vitamin E-which prevents lipid peroxidation-and by diallylsulfide-a CYP2E1 inhibitor. Menadione and paraquat, 2 pro-oxidants metabolized via NQO1, induced KLF6(Full) mRNA in a thiol-dependent manner. Antioxidants and an NQO1 inhibitor suppressed the menadione-dependent increase in KLF6(Full) and its splice variants mRNA. Furthermore, primary hepatocytes and livers from chronic alcohol-fed rats, with elevated lipid peroxidation, H(2) O(2) and CYP2E1 but with low GSH, showed a ~2-fold increase in KLF6(Full) mRNA compared to controls. Inhibition of p38 phosphorylation further up-regulated the CYP2E1 and the AA effects on KLF6(Full) mRNA, whereas inhibition JNK and ERK1/2 phosphorylation decreased both. KLF6_V1 but not KLF6(Full) ablation markedly increased TNFα levels in macrophages; thus, TNFα emerges as a downstream target of KLF6_V1. Conclusions: The novel effect of ROS on modulating KLF6(Full) expression and its splice variants could play a relevant role in liver injury and in TNFα regulation.Item Combined Activities of JNK1 and JNK2 in Hepatocytes Protect Against Toxic Liver Injury(Gastroenterology, 2016) Cubero Palero, Francisco Javier; Trautwein, ChristianBACKGROUND & AIMS: c-Jun N-terminal kinase (JNK) 1 and JNK2 are expressed in hepatocytes and have overlapping and distinct functions. JNK proteins are activated via phosphorylation in response to acetaminophen- or carbon tetrachloride (CCl4)- induced liver damage; the level of activation correlates with the degree of injury. SP600125, a JNK inhibitor, has been reported to block acetaminophen-induced liver injury. We investigated the role of JNK in drug-induced liver injury (DILI) in liver tissue from patients and in mice with genetic deletion of JNK in hepatocytes. METHODS: We studied liver sections from patients with DILI (due to acetaminophen, phenprocoumon, nonsteroidal antiinflammatory drugs, or autoimmune hepatitis) or patients without acute liver failure (controls) collected from a DILI Biobank in Germany. Levels of total and activated (phosphorylated) JNK were measured by immunohistochemistry and Western blotting. Mice with hepatocyte-specific deletion of Jnk1 (Jnk1Dhepa) or combination of Jnk1 and Jnk2 (JnkDhepa), as well as Jnk1-floxed C57BL/6 (control) mice, were given injections of CCl4 (to induce fibrosis) or acetaminophen (to induce toxic liver injury). We performed gene expression microarray and phosphoproteomic analyses to determine mechanisms of JNK activity in hepatocytes. RESULTS: Liver samples from DILI patients contained more activated JNK, predominantly in nuclei of hepatocytes and in immune cells, than healthy tissue. Administration of acetaminophen to JnkDhepa mice produced a greater level of liver injury than that observed in Jnk1Dhepa or control mice, based on levels of serum markers and microscopic and histologic analysis of liver tissues. Administration of CCl4 also induced stronger hepatic injury in JnkDhepa mice, based on increased inflammation, cell proliferation, and fibrosis progression, compared with Jnk1Dhepa or control mice. Hepatocytes from JnkDhepa mice given acetaminophen had an increased oxidative stress response, leading to decreased activation of adenosine monophosphate-activated protein kinase, total protein adenosine monophosphate-activated protein kinase levels, and pJunD and subsequent necrosis. Administration of SP600125 before or with acetaminophen protected JnkDhepa and control mice from liver injury. CONCLUSIONS: In hepatocytes, JNK1 and JNK2 appear to have combined effects in protecting mice from CCl4- and acetaminophen-induced liver injury. It is important to study the tissue-specific functions of both proteins, rather than just JNK1, in the onset of toxic liver injury. JNK inhibition with SP600125 shows off-target effects.Item Loss of Caspase-8 Protects Mice Against Inflammation-Related Hepatocarcinogenesis but Induces Non-Apoptotic Liver Injury(Gastroenterology, 2011) Liedtke, Christian; Cubero Palero, Francisco Javier; Trautwein, ChristianBACKGROUND & AIMS: Disruption of the nuclear factor-kB (NF-kB) essential modulator (NEMO) in hepatocytesof mice (NEMOAhepa mice) results in spontaneous liver apoptosis and chronic liver disease involving inflammation, steatosis, fibrosis, and development of hepatocellular carcinoma. Activation of caspase-8 (Casp8) initiates death receptor-mediated apoptosis. We investigated the pathogenic role of this protease in NEMOAhepa mice or after induction of acute liver injury. METHODS: We created mice with conditional deletion of Casp8 in hepatocytes (Casp8Ahepa) and Casp8AhepaNEMOAhepa double knockout mice. Acute liver injury was induced by Fas-activating antibodies, lipopolysaccharides, or concanavalin A. Spontaneous hepatocarcinogenesis was monitored by magnetic resonance imaging. RESULTS: Hepatocyte-specific deletion of Casp8 protected mice from induction of apoptosis and liver injury by Fas or lipopolysaccharides but increased necrotic damage and reduced survival times of mice given concanavalin A. Casp8AhepaNEMOAhepa mice were protected against steatosis and hepatocarcinogenesis but had a separate, spontaneous phenotype that included massive liver necrosis, cholestasis, and biliary lesions. The common mechanism by which inactivation of Casp8 induces liver necrosis in both injury models involves the formation of protein complexes that included the adaptor protein Fas-associated protein with death domain and the kinases receptor-interacting protein (RIP) 1 and RIP3—these have been shown to be required for programmed necrosis. We demonstrated that hepatic RIP1 was proteolytically cleaved by Casp8, whereas Casp8 inhibition resulted in accumulation of RIP complexes and subsequent liver necrosis. CONCLUSIONS: Inhibition of Casp8 protects mice from hepatocarcinogenesis following chronic liver injury mediated by apoptosis of hepatocytes but can activate RIP-mediated necrosis in an inflammatory environment.