RESUMEN
Gulf War Illness (GWI) describes a series of symptoms suffered by veterans of the Gulf war, consisting of cognitive, neurological and gastrointestinal dysfunctions. Two chemicals associated with GWI are the insecticide permethrin (PER) and the nerve gas prophylactic pyridostigmine-bromide (PB). In this study we assessed the effects of PER and PB exposure on the pathology and subsequent alcohol (EtOH)-induced liver injury, and the influence of a macrophage depletor, PLX3397, on EtOH-induced liver damage in PER/PB-treated mice. Male C57BL/6 mice were injected daily with vehicle or PER/PB for 10 days, followed by 4 months recovery, then treatment with PLX3397 and a chronic-plus-single-binge EtOH challenge for 10 days. PER/PB exposure resulted in the protracted increase in liver transaminases in the serum and induced chronic low-level microvesicular steatosis and inflammation in GWI vs Naïve mice up to 4 months after cessation of exposure. Furthermore, prior exposure to PER/PB also resulted in exacerbated response to EtOH-induced liver injury, with enhanced steatosis, ductular reaction and fibrosis. The enhanced EtOH-induced liver damage in GWI-mice was attenuated by strategies designed to deplete macrophages in the liver. Taken together, these data suggest that exposure to GWI-related chemicals may alter the liver's response to subsequent ethanol exposure.
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Etanol , Ratones Endogámicos C57BL , Síndrome del Golfo Pérsico , Bromuro de Piridostigmina , Animales , Síndrome del Golfo Pérsico/inducido químicamente , Síndrome del Golfo Pérsico/patología , Masculino , Bromuro de Piridostigmina/farmacología , Ratones , Etanol/efectos adversos , Etanol/toxicidad , Permetrina/toxicidad , Hígado/efectos de los fármacos , Hígado/patología , Insecticidas/toxicidad , Insecticidas/efectos adversos , Modelos Animales de EnfermedadRESUMEN
Gulf War Illness (GWI) describes a series of symptoms suffered by veterans of the Gulf war consisting of cognitive, neurological and gastrointestinal dysfunctions. Two chemicals associated with GWI are the insecticide permethrin (PER) and the nerve gas prophylactic pyridostigmine-bromide (PB). In this study we assessed the effects of PER and PB exposure on pathology and subsequent alcohol (EtOH)-induced liver injury, and the influence of a macrophage depletor, PLX3397, on EtOH-induced liver damage in PER/PB- treated mice. Male C57BL/6 mice were injected daily with vehicle or PER/PB for 10 days, followed by 4 months recovery, then treatment with PLX3397 and a chronic-plus-single-binge EtOH challenge for 10 days. PER/PB exposure resulted in the protracted increase in liver transaminases in the serum and induced chronic low-level microvesicular steatosis and inflammation in GWI vs Naïve mice up to 4 months after cessation of exposure. Furthermore, prior exposure to PER/PB also resulted in exacerbated response to EtOH-induced liver injury, with enhanced steatosis, ductular reaction and fibrosis. The enhanced EtOH-induced liver damage in GWI-mice was attenuated by strategies designed to deplete macrophages in the liver. Taken together, these data suggest that exposure to GWI-related chemicals may alter the liver's response to subsequent ethanol exposure.
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Leptin is an adipokine with roles in food intake and energy metabolism through its actions on neurons in the hypothalamus. The role of leptin in obesity and cardiovascular disorders is well documented. However, its influence on liver conditions such as cholestasis is poorly understood. The effects of exogenous leptin and leptin-neutralizing antibody on biliary hyperplasia, hepatic fibrosis, and inflammation in the multidrug resistance protein 2 knockout (Mdr2KO) mouse model of cholestasis were assessed by quantifying markers specific for cholangiocytes, activated hepatic stellate cells (HSCs), and cytokines. Serum and hepatic leptin were increased in Mdr2KO mice compared with FVB/NJ (FVBN) controls, and exogenous leptin enhanced biliary hyperplasia and liver fibrosis in Mdr2KO and FVBN mice. Leptin administration increased hepatic expression of C-C motif chemokine ligand 2 and IL-6 in Mdr2KO mice. In contrast, leptin-neutralizing antibody reduced intrahepatic bile duct mass and decreased HSC activation in Mdr2KO mice compared with FVBN controls. Sex-related differences were noted, with female Mdr2KO mice having more leptin than males. In cholangiocytes and LX2 cells in vitro, leptin increased phosphorylated Akt and stimulated cell proliferation. Leptin receptor siRNA and inhibitors of Akt phosphorylation impaired leptin-induced cell proliferation and proinflammatory cytokines. The current data suggest that leptin is abnormally increased in cholestatic mice, and excess leptin increases ductular reaction, hepatic fibrosis, and inflammation via leptin receptor-mediated phosphorylation of Akt in cholangiocytes and HSCs.
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Colestasis , Receptores de Leptina , Animales , Anticuerpos Neutralizantes , Colestasis/metabolismo , Citocinas/metabolismo , Modelos Animales de Enfermedad , Femenino , Células Estrelladas Hepáticas/metabolismo , Hiperplasia/patología , Inflamación/patología , Leptina/metabolismo , Leptina/farmacología , Hígado/metabolismo , Cirrosis Hepática/patología , Masculino , Ratones , Ratones Noqueados , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores de Leptina/metabolismoRESUMEN
Recent studies on liver disease burden worldwide estimated that cirrhosis is the 11th most common cause of death globally, and there is a great need for new therapies to limit the progression of liver injuries in the early stages. Cholestasis is caused by accumulation of hydrophobic bile acids (BA) in the liver due to dysfunctional BA efflux or bile flow into the gall bladder. Therefore, strategies to increase detoxification of hydrophobic BA and downregulate genes involved in BA production are largely investigated. Farnesoid X receptor (FXR) has a central role in BA homeostasis and recent publications revealed that changes in autophagy due to BA-induced reactive oxygen species and increased anti-oxidant response via nuclear factor E2-related factor 2 (NRF2), result in dysregulation of FXR signaling. Several mechanistic studies have identified new dysfunctions of the cholestatic liver at cellular and molecular level, opening new venues for developing more performant therapies.
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Ácidos y Sales Biliares/metabolismo , Colestasis/tratamiento farmacológico , Fármacos Gastrointestinales/uso terapéutico , Hepatopatías/tratamiento farmacológico , Hígado/efectos de los fármacos , Receptores Citoplasmáticos y Nucleares/efectos de los fármacos , Animales , Autofagia/efectos de los fármacos , Colestasis/complicaciones , Colestasis/diagnóstico , Colestasis/metabolismo , Fármacos Gastrointestinales/efectos adversos , Humanos , Ligandos , Hígado/metabolismo , Hígado/patología , Hepatopatías/diagnóstico , Hepatopatías/etiología , Hepatopatías/metabolismo , Terapia Molecular Dirigida , Factor 2 Relacionado con NF-E2/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Transducción de SeñalRESUMEN
The liver is a major metabolic organ and an immunologically complex organ. It produces and uses many substances such as acute phase proteins, cytokines, chemokines, and complementary components to maintain the balance between immunity and tolerance. Interleukins are important immune control cytokines, that are produced by many body cells. In liver injury, interleukins are produced in large amount by various cell types, and act as pro-inflammatory (e.g. interleukin (IL)-6, IL-13, IL-17, and IL-33) as well as anti-inflammatory (e.g. IL-10) functions in hepatic cells. Recently, interleukins are regarded as interesting therapeutic targets for the treatment of liver fibrosis patients. Hepatic cells such as hepatocytes, hepatic stellate cells, and hepatic macrophages are involved to the initiation, perpetuation, and resolution of fibrosis. The understanding of the role of interleukins in such cells provides opportunity for the development of therapeutic target drugs. This paper aims to understand the functional roles of interleukins in hepatic and immune cells when the liver is damaged, and suggests the possibility of interleukins as a new treatment target in liver fibrosis.
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The orexigenic peptide ghrelin (Ghr) stimulates hunger signals in the hypothalamus via growth hormone secretagogue receptor (GHS-R1a). Gastric Ghr is synthetized as a preprohormone which is proteolytically cleaved, and acylated by a membrane-bound acyl transferase (MBOAT). Circulating Ghr is reduced in cholestatic injuries, however Ghr's role in cholestasis is poorly understood. We investigated Ghr's effects on biliary hyperplasia and hepatic fibrosis in Mdr2-knockout (Mdr2KO) mice, a recognized model of cholestasis. Serum, stomach and liver were collected from Mdr2KO and FVBN control mice treated with Ghr, des-octanoyl-ghrelin (DG) or vehicle. Mdr2KO mice had lower expression of Ghr and MBOAT in the stomach, and lower levels of circulating Ghr compared to WT-controls. Treatment of Mdr2KO mice with Ghr improved plasma transaminases, reduced biliary and fibrosis markers. In the liver, GHS-R1a mRNA was expressed predominantly in cholangiocytes. Ghr but not DG, decreased cell proliferation via AMPK activation in cholangiocytes in vitro. AMPK inhibitors prevented Ghr-induced FOXO1 nuclear translocation and negative regulation of cell proliferation. Ghr treatment reduced ductular reaction and hepatic fibrosis in Mdr2KO mice, regulating cholangiocyte proliferation via GHS-R1a, a G-protein coupled receptor which causes increased intracellular Ca2+ and activation of AMPK and FOXO1, maintaining a low rate of cholangiocyte proliferation.
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Colestasis/tratamiento farmacológico , Ghrelina/administración & dosificación , Cirrosis Hepática/prevención & control , Receptores de Ghrelina/genética , Subfamilia B de Transportador de Casetes de Unión a ATP/genética , Acetiltransferasas/metabolismo , Animales , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Colestasis/genética , Colestasis/metabolismo , Modelos Animales de Enfermedad , Proteína Forkhead Box O1/metabolismo , Ghrelina/metabolismo , Ghrelina/farmacología , Cirrosis Hepática/genética , Cirrosis Hepática/metabolismo , Ratones , Ratones Noqueados , Transaminasas/sangre , Miembro 4 de la Subfamilia B de Casete de Unión a ATPRESUMEN
Allergic diseases have been classified in the last decades using various theories. The main classes of the newest classification in allergic respiratory diseases focus on the characterization of the endotype (which takes into account biomarkers related to determinant pathophysiological mechanisms) and of the phenotype (based on the description of the disease). Th2, Th1 and Th17 lymphocytes and the type of inflammatory response mediated by them represent the basis for Th2 and non-Th2 endotype classification. In addition, new lymphocytes were also used to characterize allergic diseases: Th9 lymphocytes, Th22 lymphocytes, T follicular helper cells (TFH) lymphocytes and invariant natural killer T (iNKT) lymphocytes. In the last decade, a growing body of evidence focused on chemokines, chemoattractant cytokines, which seems to have an important contribution to the pathogenesis of this pathology. This review presents the interactions between chemokines and Th lymphocytes in the context of Th2/non-Th2 endotype classification of respiratory allergies.
RESUMEN
Background Allergic rhinitis (AR) is a chronic and frequent condition characterized by an excessive response of the immune system to innocent substances encountered in the nasal mucosa. These reactions are mediated by many factors, including chemokines. Chemokine ligand 3 (CCL3, a macrophage inflammatory protein 1α) is a chemokine implicated in the activation of mast cells - white cells shown to be highly involved in orchestrating allergic reactions. The present study evaluated the role of CCL3 in AR. Material and methods Thirty-nine participants, including 24 patients with AR and 15 healthy controls, were evaluated for allergies to dust mites, cat and dog danders, cockroaches (Blatella germanica), molds, grasses, weeds, and tree pollen using skin prick tests. Participants were also evaluated for inflammatory conditions by measuring total blood count with differential; concentrations of rheumatoid factor, fibrinogen, and C-reactive protein; and erythrocyte sedimentation rate. CCL3 in blood samples was measured at the Immunology Laboratory, Cantacuzino National Institute for Military Medical Research and Development, Bucharest, Romania, using Human Multianalyte Profiling Base Kits (R&D Systems Inc., Minneapolis, MN). Results Mean serum CCL3 concentration was significantly higher in patients with AR than in controls (15.03 ± 7.11 pg/ml vs. 8.34 ± 4.46 pg/ml, p = 0.001 [t-test] and p = 0.026 [Mann-Whitney test]). CCL3 concentrations correlated with polysensitization, defined as two or more positive prick tests per patient (r = 0.325, p = 0.046) and seasonal AR (r = 0.482, p = 0.002). Conclusions Elevated levels of CCL3 were seen in our patients with AR. We have observed correlations with polysensitization and seasonal allergies. These results suggest that chemokines might play an important role in the pathogenesis of AR. In the future, chemokines might be used in endotype classification of patients with AR and as a possible target in the treatment of AR.
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Galanin (Gal) is a peptide with a role in neuroendocrine regulation of the liver. In this study, we assessed the role of Gal and its receptors, Gal receptor 1 (GalR1) and Gal receptor 2 (GalR2), in cholangiocyte proliferation and liver fibrosis in multidrug resistance protein 2 knockout (Mdr2KO) mice as a model of chronic hepatic cholestasis. The distribution of Gal, GalR1, and GalR2 in specific liver cell types was assessed by laser-capture microdissection and confocal microscopy. Galanin immunoreactivity was detected in cholangiocytes, hepatic stellate cells (HSCs), and hepatocytes. Cholangiocytes expressed GalR1, whereas HSCs and hepatocytes expressed GalR2. Strategies were used to either stimulate or block GalR1 and GalR2 in FVB/N (wild-type) and Mdr2KO mice and measure biliary hyperplasia and hepatic fibrosis by quantitative PCR and immunostaining of specific markers. Galanin treatment increased cholangiocyte proliferation and fibrogenesis in both FVB/N and Mdr2KO mice. Suppression of GalR1, GalR2, or both receptors in Mdr2KO mice resulted in reduced bile duct mass and hepatic fibrosis. In vitro knockdown of GalR1 in cholangiocytes reduced α-smooth muscle actin expression in LX-2 cells treated with cholangiocyte-conditioned media. A GalR2 antagonist inhibited HSC activation when Gal was administered directly to LX-2 cells, but not via cholangiocyte-conditioned media. These data demonstrate that Gal contributes not only to cholangiocyte proliferation but also to liver fibrogenesis via the coordinate activation of GalR1 in cholangiocytes and GalR2 in HSCs.
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Subfamilia B de Transportador de Casetes de Unión a ATP/genética , Colestasis/metabolismo , Galanina/metabolismo , Cirrosis Hepática/metabolismo , Receptor de Galanina Tipo 1/metabolismo , Receptor de Galanina Tipo 2/metabolismo , Animales , Conductos Biliares/metabolismo , Proliferación Celular , Colestasis/patología , Modelos Animales de Enfermedad , Células Epiteliales/metabolismo , Femenino , Galanina/genética , Células Estrelladas Hepáticas/metabolismo , Células Estrelladas Hepáticas/patología , Hígado/metabolismo , Hígado/patología , Cirrosis Hepática/patología , Ratones , Ratones Noqueados , Receptor de Galanina Tipo 1/genética , Receptor de Galanina Tipo 2/genética , Miembro 4 de la Subfamilia B de Casete de Unión a ATPRESUMEN
Acute liver failure is a serious consequence of acetaminophen (APAP)-induced hepatotoxic liver injury with high rates of morbidity and mortality. Transforming growth factor beta 1 (TGFß1) is elevated during liver injury and influences hepatocyte senescence during APAP-induced hepatotoxicity. This study investigated TGFß1 signaling in the context of inflammation, necrotic cell death, and oxidative stress during APAP-induced liver injury. Male C57Bl/6 mice were injected with 600 mg/kg APAP to generate liver injury in the presence or absence of the TGFß receptor 1 inhibitor, GW788388, 1 h prior to APAP administration. Acetaminophen-induced liver injury was characterized using histological and biochemical measures. Transforming growth factor beta 1 expression and signal transduction were assessed using immunohistochemistry, Western blotting and ELISA assays. Hepatic necrosis, liver injury, cell proliferation, hepatic inflammation, and oxidative stress were assessed in all mice. Acetaminophen administration significantly induced necrosis and elevated serum transaminases compared with control mice. Transforming growth factor beta 1 staining was observed in and around areas of necrosis with phosphorylation of SMAD3 observed in hepatocytes neighboring necrotic areas in APAP-treated mice. Pretreatment with GW788388 prior to APAP administration in mice reduced hepatocyte cell death and stimulated regeneration. Phosphorylation of SMAD3 was reduced in APAP mice pretreated with GW788388 and this correlated with reduced hepatic cytokine production and oxidative stress. These results support that TGFß1 signaling plays a significant role in APAP-induced liver injury by influencing necrotic cell death, inflammation, oxidative stress, and hepatocyte regeneration. In conclusion, targeting TGFß1 or downstream signaling may be a possible therapeutic target for the management of APAP-induced liver injury.
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Acetaminofén/toxicidad , Benzamidas/farmacología , Hepatocitos/metabolismo , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Pirazoles/farmacología , Factor de Crecimiento Transformador beta/antagonistas & inhibidores , Factor de Crecimiento Transformador beta/metabolismo , Animales , Antioxidantes , Apoptosis/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Glutatión/metabolismo , Hepatocitos/efectos de los fármacos , Hepatocitos/patología , Inflamación , Hígado/efectos de los fármacos , Fallo Hepático Agudo/inducido químicamente , Masculino , Ratones , Ratones Endogámicos C57BL , Necrosis/metabolismo , Estrés Oxidativo/efectos de los fármacos , Fosforilación , Sustancias Protectoras/farmacología , Regeneración , Transducción de Señal/efectos de los fármacosRESUMEN
BACKGROUND: Acute liver failure resulting from drug-induced liver injury can lead to the development of neurological complications called hepatic encephalopathy (HE). Hepatic transforming growth factor beta 1 (TGFß1) is upregulated due to liver failure in mice and inhibiting circulating TGFß reduced HE progression. However, the specific contributions of TGFß1 on brain cell populations and neuroinflammation during HE are not known. Therefore, the aim of this study was to characterize hepatic and brain TGFß1 signaling during acute liver failure and its contribution to HE progression using a combination of pharmacological and genetic approaches. METHODS: C57Bl/6 or neuron-specific transforming growth factor beta receptor 2 (TGFßR2) null mice (TGFßR2ΔNeu) were treated with azoxymethane (AOM) to induce acute liver failure and HE. The activity of circulating TGFß1 was inhibited in C57Bl/6 mice via injection of a neutralizing antibody against TGFß1 (anti-TGFß1) prior to AOM injection. In all mouse treatment groups, liver damage, neuroinflammation, and neurological deficits were assessed. Inflammatory signaling between neurons and microglia were investigated in in vitro studies through the use of pharmacological inhibitors of TGFß1 signaling in HT-22 and EOC-20 cells. RESULTS: TGFß1 was expressed and upregulated in the liver following AOM injection. Pharmacological inhibition of TGFß1 after AOM injection attenuated neurological decline, microglia activation, and neuroinflammation with no significant changes in liver damage. TGFßR2ΔNeu mice administered AOM showed no effect on liver pathology but significantly reduced neurological decline compared to control mice. Microglia activation and neuroinflammation were attenuated in mice with pharmacological inhibition of TGFß1 or in TGFßR2ΔNeu mice. TGFß1 increased chemokine ligand 2 (CCL2) and decreased C-X3-C motif ligand 1 (CX3CL1) expression in HT-22 cells and reduced interleukin-1 beta (IL-1ß) expression, tumor necrosis factor alpha (TNFα) expression, and phagocytosis activity in EOC-20 cells. CONCLUSION: Increased circulating TGFß1 following acute liver failure results in activation of neuronal TGFßR2 signaling, driving neuroinflammation and neurological decline during AOM-induced HE.
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Corteza Cerebral/patología , Encefalopatía Hepática/etiología , Fallo Hepático Agudo/complicaciones , Fallo Hepático Agudo/patología , Neuronas/metabolismo , Receptor Tipo II de Factor de Crecimiento Transformador beta/deficiencia , Factor de Crecimiento Transformador beta1/sangre , Animales , Anticuerpos/uso terapéutico , Azoximetano/toxicidad , Benzamidas/farmacología , Carcinógenos/toxicidad , Línea Celular Transformada , Modelos Animales de Enfermedad , Encefalopatía Hepática/tratamiento farmacológico , Inflamación/tratamiento farmacológico , Inflamación/etiología , Isoquinolinas/farmacología , Hígado/metabolismo , Hígado/patología , Fallo Hepático Agudo/inducido químicamente , Fallo Hepático Agudo/genética , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Microglía/efectos de los fármacos , Neuronas/efectos de los fármacos , Fagocitosis/efectos de los fármacos , Fagocitosis/genética , Pirazoles/farmacología , Piridinas/farmacología , Pirroles/farmacología , Receptor Tipo II de Factor de Crecimiento Transformador beta/genética , Transducción de Señal/efectos de los fármacos , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/inmunología , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genéticaRESUMEN
The Hypothalamic-Pituitary-Adrenal (HPA) axis has an important role in maintaining the physiological homeostasis in relation to external and internal stimuli. The HPA axis dysfunctions were extensively studied in neuroendocrine disorders such as depression and chronic fatigue syndrome but less so in hepatic cholestasis, cirrhosis or other liver diseases. The HPA axis controls many functions of the liver through neuroendocrine forward signaling pathways as well as negative feedback mechanisms, in health and disease. This review describes cell and molecular mechanisms of liver and HPA axis physiology and pathology. Evidence is presented from clinical and experimental model studies, demonstrating that dysfunctions of HPA axis are correlated with liver cholestatic disorders. The functional interactions of HPA axis with the liver and immune system in cases of bacterial and viral infections are also discussed. Proinflammatory cytokines stimulate glucocorticoid (GC) release by adrenals but they also inhibit bile acid (BA) efflux from liver. Chronic hepatic inflammation leads to cholestasis and impaired GC metabolism in the liver, so that HPA axis becomes depressed. Recently discovered interactions of GC with self-oscillating transcription factors that generate circadian rhythms of gene expression in brain and liver, in the context of GC replacement therapies, are also outlined.
RESUMEN
Gulf War Illness (GWI) is a chronic multisymptom disorder affecting veterans of the 1990-91 Gulf war. GWI was linked with exposure to chemicals including the nerve gas prophylactic drug pyridostigmine-bromide (PB) and pesticides (DEET, permethrin). Veterans with GWI exhibit prolonged, low-level systemic inflammation, though whether this impacts the liver is unknown. While no evidence exists that GWI-related chemicals are hepatotoxic, the prolonged inflammation may alter the liver's response to insults such as cholestatic injury. We assessed the effects of GWI-related chemicals on macrophage infiltration and its subsequent influence on hepatic cholestasis. Sprague Dawley rats were treated daily with PB, DEET and permethrin followed by 15 minutes of restraint stress for 28 days. Ten weeks afterward, GWI rats or naïve age-matched controls underwent bile duct ligation (BDL) or sham surgeries. Exposure to GWI-related chemicals alone increased IL-6, and CD11b+F4/80- macrophages in the liver, with no effect on biliary mass or hepatic fibrosis. However, pre-exposure to GWI-related chemicals enhanced biliary hyperplasia and fibrogenesis caused by BDL, compared to naïve rats undergoing the same surgery. These data suggest that GWI patients could be predisposed to developing worse liver pathology due to sustained low-level inflammation of the liver when compared to patients without GWI.
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Colestasis/inmunología , DEET/toxicidad , Permetrina/toxicidad , Síndrome del Golfo Pérsico/inmunología , Bromuro de Piridostigmina/toxicidad , Estrés Psicológico/inmunología , Animales , Conductos Biliares/efectos de los fármacos , Conductos Biliares/inmunología , Conductos Biliares/patología , Conductos Biliares/cirugía , Antígeno CD11b/genética , Antígeno CD11b/inmunología , Movimiento Celular/efectos de los fármacos , Colestasis/genética , Colestasis/psicología , Colestasis/cirugía , Modelos Animales de Enfermedad , Expresión Génica , Humanos , Inmovilización , Inflamación , Interleucina-6/genética , Interleucina-6/inmunología , Ligadura , Hígado/efectos de los fármacos , Hígado/inmunología , Hígado/patología , Masculino , Monocitos/efectos de los fármacos , Monocitos/inmunología , Monocitos/patología , Síndrome del Golfo Pérsico/inducido químicamente , Síndrome del Golfo Pérsico/genética , Síndrome del Golfo Pérsico/psicología , Ratas , Ratas Sprague-Dawley , Estrés Psicológico/genética , Estrés Psicológico/patologíaRESUMEN
BACKGROUND & AIMS: Hepatic encephalopathy is a serious neurologic complication of acute and chronic liver diseases. We previously showed that aberrant bile acid signaling contributes to the development of hepatic encephalopathy via farnesoid X receptor (FXR)-mediated mechanisms in neurons. In the brain, a novel alternative bile acid synthesis pathway, catalyzed by cytochrome p450 46A1 (Cyp46A1), is the primary mechanism by which the brain regulates cholesterol homeostasis. The aim of this study was to determine if FXR activation in the brain altered cholesterol homeostasis during hepatic encephalopathy. METHODS: Cyp7A1-/- mice or C57Bl/6 mice pretreated with central infusion of FXR vivo morpholino, 2-hydroxypropyl-ß-cyclodextrin, or fed a cholestyramine-supplemented diet were injected with azoxymethane (AOM). Cognitive and neuromuscular impairment as well as liver damage and expression of Cyp46A1 were assessed using standard techniques. The subsequent cholesterol content in the frontal cortex was measured using commercially available kits and by Filipin III and Nile Red staining. RESULTS: There was an increase in membrane-bound and intracellular cholesterol in the cortex of mice treated with AOM that was associated with decreased Cyp46A1 expression. Strategies to inhibit FXR signaling prevented the down-regulation of Cyp46A1 and the accumulation of cholesterol. Treatment of mice with 2-hydroxypropyl-ß-cyclodextrin attenuated the AOM-induced cholesterol accumulation in the brain and the cognitive and neuromuscular deficits without altering the underlying liver pathology. CONCLUSIONS: During hepatic encephalopathy, FXR signaling increases brain cholesterol and contributes to neurologic decline. Targeting cholesterol accumulation in the brain may be a possible therapeutic target for the management of hepatic encephalopathy.
RESUMEN
Acute liver failure is a devastating consequence of hepatotoxic liver injury that can lead to the development of hepatic encephalopathy. There is no consensus on the best model to represent these syndromes in mice, and therefore the aim of this study was to classify hepatic and neurological consequences of azoxymethane- and thioacetamide-induced liver injury. Azoxymethane-treated mice were euthanized at time points representing absence of minor and significant stages of neurological decline. Thioacetamide-treated mice had tissue collected at up to 3 days following daily injections. Liver histology, serum chemistry, bile acids, and cytokine levels were measured. Reflexes, grip strength measurement, and ataxia were calculated for all groups. Brain ammonia, bile acid levels, cerebral edema, and neuroinflammation were measured. Finally, in vitro and in vivo assessments of blood-brain barrier function were performed. Serum transaminases and liver histology demonstrate that both models generated hepatotoxic liver injury. Serum proinflammatory cytokine levels were significantly elevated in both models. Azoxymethane-treated mice had progressive neurological deficits, while thioacetamide-treated mice had inconsistent neurological deficits. Bile acids and cerebral edema were increased to a higher degree in azoxymethane-treated mice, while cerebral ammonia and neuroinflammation were greater in thioacetamide-treated mice. Blood-brain barrier permeability exists in both models but was likely not due to direct toxicity of azoxymethane or thioacetamide on brain endothelial cells. In conclusion, both models generate acute liver injury and hepatic encephalopathy, but the requirement of a single injection and the more consistent neurological decline make azoxymethane treatment a better model for acute liver failure with hepatic encephalopathy.
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Azoximetano/toxicidad , Modelos Animales de Enfermedad , Encefalopatía Hepática/patología , Tioacetamida/toxicidad , Animales , Biomarcadores/sangre , Encéfalo/metabolismo , Encéfalo/patología , Encefalopatía Hepática/etiología , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
Hepatic cholestasis is associated with a significant suppression of the hypothalamus-pituitary-adrenal axis (HPA). In the present study, we tested the hypothesis that activation of the HPA axis by corticosterone treatment can reverse liver inflammation and fibrosis in a multidrug resistance protein 2 knockout (MDR2KO) transgenic mouse model of hepatic cholestasis. Friend Virus B NIH-Jackson (FVBN) control and MDR2KO male and female mice were treated with vehicle or corticosterone for two weeks, then serum and liver analyses of hepatic cholestasis markers were performed. Indicators of inflammation, such as increased numbers of macrophages, were determined. MDR2KO mice had lower corticotropin releasing hormone and corticosterone levels than FVBN controls in the serum. There was a large accumulation of CD68 and F4/80 macrophages in MDR2KO mice livers, which indicated greater inflammation compared to FVBNs, an effect reversed by corticosterone treatment. Intrahepatic biliary duct mass, collagen deposition and alpha smooth muscle actin (αSMA) were found to be much higher in livers of MDR2KO mice than in controls; corticosterone treatment significantly decreased these fibrosis markers. When looking at the gender-specific response to corticosterone treatment, male MDR2KO mice tended to have a more pronounced reversal of liver fibrosis than females treated with corticosterone.
Asunto(s)
Subfamilia B de Transportador de Casetes de Unión a ATP/genética , Glucocorticoides/administración & dosificación , Inflamación/genética , Cirrosis Hepática/genética , Animales , Corticosterona/sangre , Hormona Liberadora de Corticotropina/sangre , Femenino , Sistema Hipotálamo-Hipofisario/metabolismo , Inflamación/sangre , Inflamación/patología , Hígado/metabolismo , Hígado/patología , Cirrosis Hepática/sangre , Cirrosis Hepática/metabolismo , Cirrosis Hepática/patología , Masculino , Ratones , Ratones Noqueados , Sistema Hipófiso-Suprarrenal/metabolismo , Caracteres Sexuales , Miembro 4 de la Subfamilia B de Casete de Unión a ATPRESUMEN
Hepatic encephalopathy (HE) is a neuropsychiatric complication that occurs due to deteriorating hepatic function and this syndrome influences patient quality of life, clinical management strategies and survival. During acute liver failure, circulating bile acids increase due to a disruption of the enterohepatic circulation. We previously identified that bile acid-mediated signaling occurs in the brain during HE and contributes to cognitive impairment. However, the influences of bile acids and their downstream signaling pathways on HE-induced neuroinflammation have not been assessed. Conjugated bile acids, such as taurocholic acid (TCA), can activate sphingosine-1-phosphate receptor 2 (S1PR2), which has been shown to promote immune cell infiltration and inflammation in other models. The current study aimed to assess the role of bile-acid mediated S1PR2 signaling in neuroinflammation and disease progression during azoxymethane (AOM)-induced HE in mice. Our findings demonstrate a temporal increase of bile acids in the cortex during AOM-induced HE and identified that cortical bile acids were elevated as an early event in this model. In order to classify the specific bile acids that were elevated during HE, a metabolic screen was performed and this assay identified that TCA was increased in the serum and cortex during AOM-induced HE. To reduce bile acid concentrations in the brain, mice were fed a diet supplemented with cholestyramine, which alleviated neuroinflammation by reducing proinflammatory cytokine expression in the cortex compared to the control diet-fed AOM-treated mice. S1PR2 was expressed primarily in neurons and TCA treatment increased chemokine ligand 2 mRNA expression in these cells. The infusion of JTE-013, a S1PR2 antagonist, into the lateral ventricle prior to AOM injection protected against neurological decline and reduced neuroinflammation compared to DMSO-infused AOM-treated mice. Together, this identifies that reducing bile acid levels or S1PR2 signaling are potential therapeutic strategies for the management of HE.
RESUMEN
This study provides insight into the attitude of Romanian consumers towards organic food. Furthermore, it examines the sustainable food production system in Romania from the perspective of consumer behavior. This study used a mathematical model of linear regression with the main purpose being to determine the best prediction for the dependent variable when given a number of new values for the independent variable. This empirical research is based on a survey with a sample of 672 consumers, which uses a questionnaire to analyze their intentions towards sustainable food products. The results indicate that a more positive attitude of consumers towards organic food products will further strengthen their purchasing intentions, while the status of the consumption of organic consumers will not affect their willingness to purchase organic food products. Statistics have shown that sustainable food consumption is beneficial for health, so it can also become a profitable business in Romania. Furthermore, food sustainability in Romania depends on the ability of an organic food business to adapt to the new requirements of green consumption.
RESUMEN
Although human liver fatty acid-binding protein (FABP1) T94A variant has been associated with nonalcoholic fatty liver disease and reduced ability of fenofibrate to lower serum triglycerides (TG) to target levels, molecular events leading to this phenotype are poorly understood. Cultured primary hepatocytes from female human subjects expressing the FABP1 T94A variant exhibited increased neutral lipid (TG, cholesteryl ester) accumulation associated with (1) upregulation of total FABP1, a key protein stimulating mitochondrial glycerol-3-phosphate acyltransferase (GPAM), the rate-limiting enzyme in lipogenesis; (2) increased mRNA expression of key enzymes in lipogenesis (GPAM, LPIN2) in heterozygotes; (3) decreased mRNA expression of microsomal triglyceride transfer protein; (4) increased secretion of ApoB100 but not TG; (5) decreased long-chain fatty acid (LCFA) ß-oxidation. TG accumulation was not due to any increase in LCFA uptake, de novo lipogenesis, or the alternate monoacylglycerol O-acyltransferase pathway in lipogenesis. Despite increased expression of total FABP1 mRNA and protein, fenofibrate-mediated FABP1 redistribution to nuclei and ligand-induced peroxisome proliferator-activated receptor (PPAR-α) transcription of LCFA ß-oxidative enzymes (carnitine palmitoyltransferase 1A, carnitine palmitoyltransferase 2, and acyl-coenzyme A oxidase 1, palmitoyl) were attenuated in FABP1 T94A hepatocytes. Although the phenotype of FABP1 T94A variant human hepatocytes exhibits some similarities to that of FABP1-null or PPAR-α-null hepatocytes and mice, expression of FABP1 T94A variant did not abolish or reduce ligand binding. Thus the FABP1 T94A variant represents an altered/reduced function mutation resulting in TG accumulation.