RESUMEN
Lifestyle interventions remain the treatment of choice for patients with obesity and metabolic complications, yet are difficult to maintain and often lead to cycles of weight loss and regain (weight cycling). Literature on weight cycling remains controversial and we therefore investigated the association between weight cycling and metabolic complications using preexistent obese mice. Ldlr-/-.Leiden mice received a high-fat diet (HFD) for 20 weeks to induce obesity. Subsequently, weight-cycled mice were switched between the healthy chow diet and HFD for four 2-week periods and compared to mice that received HFD for the total study period. Repeated weight cycling tended to decrease body weight and significantly reduced fat mass, whereas adipose tissue inflammation was similar relative to HFD controls. Weight cycling did not significantly affect blood glucose or plasma insulin levels yet significantly reduced plasma free fatty acid and alanine transaminase/aspartate transaminase levels. Hepatic macrovesicular steatosis was similar and microvesicular steatosis tended to be increased upon weight cycling. Weight cycling resulted in a robust decrease in hepatic inflammation compared to HFD controls while hepatic fibrosis and atherosclerosis development were not affected. These results argue against the postulate that repeated weight cycling leads to unfavorable metabolic effects, when compared to a continuous unhealthy lifestyle, and in fact revealed beneficial effects on hepatic inflammation, an important hallmark of non-alcoholic steatohepatitis.
Asunto(s)
Hígado , Enfermedad del Hígado Graso no Alcohólico , Humanos , Ratones , Animales , Hígado/metabolismo , Ratones Obesos , Ciclo del Peso , Enfermedad del Hígado Graso no Alcohólico/etiología , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Obesidad/complicaciones , Inflamación/metabolismo , Dieta Alta en Grasa/efectos adversos , Ratones Endogámicos C57BLRESUMEN
Patients with metabolic syndrome are often prescribed statins to prevent the development of cardiovascular disease. Conversely, data on their effects on non-alcoholic steatohepatitis (NASH) are lacking. We evaluated these effects by feeding APOE*3-Leiden mice a Western-type diet (WTD) with or without atorvastatin to induce NASH and hepatic fibrosis. Besides the well-known plasma cholesterol lowering (-30%) and anti-atherogenic effects (severe lesion size -48%), atorvastatin significantly reduced hepatic steatosis (-22%), the number of aggregated inflammatory cells in the liver (-80%) and hepatic fibrosis (-92%) compared to WTD-fed mice. Furthermore, atorvastatin-treated mice showed less immunohistochemically stained areas of inflammation markers. Atorvastatin prevented accumulation of free cholesterol in the form of cholesterol crystals (-78%). Cholesterol crystals are potent inducers of the NLRP3 inflammasome pathway and atorvastatin prevented its activation, which resulted in reduced expression of the pro-inflammatory cytokines interleukin (IL)-1ß (-61%) and IL-18 (-26%). Transcriptome analysis confirmed strong reducing effects of atorvastatin on inflammatory mediators, including NLRP3, NFκB and TLR4. The present study demonstrates that atorvastatin reduces hepatic steatosis, inflammation and fibrosis and prevents cholesterol crystal formation, thereby precluding NLRP3 inflammasome activation. This may render atorvastatin treatment as an attractive approach to reduce NAFLD and prevent progression into NASH in dyslipidemic patients.
Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Ratones , Animales , Enfermedad del Hígado Graso no Alcohólico/etiología , Enfermedad del Hígado Graso no Alcohólico/inducido químicamente , Atorvastatina/efectos adversos , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Hígado/metabolismo , Cirrosis Hepática/metabolismo , Inflamación/metabolismo , Colesterol/metabolismo , Dieta , Apolipoproteínas E/metabolismo , Ratones Endogámicos C57BLRESUMEN
Semaglutide, a glucagon-like peptide-1 receptor agonist, is an antidiabetic medication that has recently been approved for the treatment of obesity as well. Semaglutide is postulated to be a promising candidate for the treatment of non-alcoholic steatohepatitis (NASH). Here, Ldlr-/-.Leiden mice received a fast-food diet (FFD) for 25 weeks, followed by another 12 weeks on FFD with daily subcutaneous injections of semaglutide or vehicle (control). Plasma parameters were evaluated, livers and hearts were examined, and hepatic transcriptome analysis was performed. In the liver, semaglutide significantly reduced macrovesicular steatosis (-74%, p < 0.001) and inflammation (-73%, p < 0.001) and completely abolished microvesicular steatosis (-100%, p < 0.001). Histological and biochemical assessment of hepatic fibrosis showed no significant effects of semaglutide. However, digital pathology revealed significant improvements in the degree of collagen fiber reticulation (-12%, p < 0.001). Semaglutide did not affect atherosclerosis relative to controls. Additionally, we compared the transcriptome profile of FFD-fed Ldlr-/-.Leiden mice with a human gene set that differentiates human NASH patients with severe fibrosis from those with mild fibrosis. In FFD-fed Ldlr-/-.Leiden control mice, this gene set was upregulated as well, while semaglutide predominantly reversed this gene expression. Using a translational model with advanced NASH, we demonstrated that semaglutide is a promising candidate with particular potential for the treatment of hepatic steatosis and inflammation, while for the reversal of advanced fibrosis, combinations with other NASH agents may be necessary.
Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Humanos , Ratones , Animales , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/etiología , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Hígado/metabolismo , Cirrosis Hepática/metabolismo , Fibrosis , Inflamación/metabolismo , Ratones Endogámicos C57BL , Modelos Animales de EnfermedadRESUMEN
The nature of the chronic inflammatory component that drives the development of non-alcoholic steatohepatitis (NASH) is unclear and possible inflammatory triggers have not been investigated systematically. We examined the effect of non-metabolic triggers (lipopolysaccharide (LPS), interleukin-1ß (IL-1ß), administered by slow-release minipumps) and metabolic dietary triggers (carbohydrate, cholesterol) of inflammation on the progression of bland liver steatosis (BS) to NASH. Transgenic APOE3*Leiden.huCETP (APOE3L.CETP) mice fed a high-fat diet (HFD) developed BS after 10 weeks. Then, inflammatory triggers were superimposed or not (control) for six more weeks. Mouse livers were analyzed with particular emphasis on hallmarks of inflammation which were defined in human liver biopsies with and without NASH. Livers of HFD-treated control mice remained steatotic and did not progress to NASH. All four inflammatory triggers activated hepatic nuclear factor-κB (NF-κB) significantly and comparably (≥5-fold). However, HFD+LPS or HFD+IL-1ß did not induce a NASH-like phenotype and caused intrahepatic accumulation of almost exclusively mononuclear cells. By contrast, mice treated with metabolic triggers developed NASH, characterized by enhanced steatosis, hepatocellular hypertrophy, and formation of mixed-type inflammatory foci containing myeloperoxidase-positive granulocytes (neutrophils) as well as mononuclear cells, essentially as observed in human NASH. Specific for the metabolic inducers was an activation of the proinflammatory transcription factor activator protein-1 (AP-1), neutrophil infiltration, and induction of risk factors associated with human NASH, that is, dyslipidemia (by cholesterol) and insulin resistance (by carbohydrate). In conclusion, HFD feeding followed by NF-κB activation per se (LPS, IL-1ß) does not promote the transition from BS to NASH. HFD feeding followed by metabolically evoked inflammation induces additional inflammatory components (neutrophils, AP-1 pathway) and causes NASH.
Asunto(s)
Dieta Alta en Grasa/efectos adversos , Hígado Graso/etiología , Hígado Graso/patología , Interleucina-1beta/toxicidad , Lipopolisacáridos/toxicidad , Animales , Enfermedad Crónica , Dislipidemias/complicaciones , Dislipidemias/metabolismo , Dislipidemias/patología , Hígado Graso/metabolismo , Femenino , Humanos , Mediadores de Inflamación/administración & dosificación , Mediadores de Inflamación/toxicidad , Resistencia a la Insulina , Masculino , Ratones , Persona de Mediana Edad , Monocitos/metabolismo , Monocitos/patología , FN-kappa B/metabolismo , Infiltración Neutrófila/inmunología , Enfermedad del Hígado Graso no Alcohólico , Factor de Transcripción AP-1/metabolismoRESUMEN
Muscle-aging drives sarcopenia and is a major public health issue. Mice are frequently used as a model for human muscle-aging, however, research investigating their translational value is limited. In addition, mechanisms underlying muscle-aging may have sex-specific features in humans, but it is not yet assessed whether these are recapitulated in mice. Here, we studied the effects of aging on a functional, histological and transcriptional level at multiple timepoints in male and female mice (4, 17, 21 and 25 months), with particular emphasis on sex-differences. The effects of natural aging on the transcriptome of quadriceps muscle were compared to humans on pathway level. Significant loss of muscle mass occurred late, at 25 months, in both male (-17%, quadriceps) and female mice (-10%, quadriceps) compared to young control mice. Concomitantly, we found in female, but not male mice, a slower movement speed in the aged groups compared to the young mice (P < 0.001). Consistently, weighted gene co-expression network analysis revealed a stronger association between the aging-related reduction of movement and aging-related changes in muscle transcriptome of female compared to male mice (P < 0.001). In male, but not female mice, major distinctive aging-related changes occurred in the last age group (25 months), which highlights the necessity for careful selection of age using mice as a muscle-aging model. Furthermore, contrasting to humans, more aging-related changes were found in the muscle transcriptome of male mice compared to female mice (4090 vs. 2285 differentially expressed genes at 25 months, respectively). Subsequently, male mice recapitulated more muscle-aging related pathways characteristic for both male and female humans. In conclusion, our data show that sex has a critical effect on the mouse muscle-aging trajectory, although these do not necessarily reflect sex differences observed in the human muscle-aging trajectory.
Asunto(s)
Envejecimiento , Sarcopenia , Humanos , Femenino , Masculino , Ratones , Animales , Anciano , Envejecimiento/fisiología , Sarcopenia/metabolismo , Perfilación de la Expresión Génica , Transcriptoma , Músculos/metabolismo , Músculos/patologíaRESUMEN
Realistic models predicting hepatobiliary processes in health and disease are lacking. We therefore aimed to develop a physiologically relevant human liver model consisting of normothermic machine perfusion (NMP) of explanted diseased human livers that can assess hepatic extraction, clearance, biliary excretion, and drug-drug interaction (DDI). Eleven livers were included in the study, seven with a cirrhotic and four with a noncirrhotic disease background. After explantation of the diseased liver, NMP was initiated. After 120 minutes of perfusion, a drug cocktail (rosuvastatin, digoxin, metformin, and furosemide; OATP1B1/1B3, P-gp, BCRP, and OCT1 model compounds) was administered to the portal vein and 120 minutes later, a second bolus of the drug cocktail was co-administered with perpetrator drugs to study relevant DDIs. The explanted livers showed good viability and functionality during 360 minutes of NMP. Hepatic extraction ratios close to in vivo reported values were measured. Hepatic clearance of rosuvastatin and digoxin showed to be the most affected by cirrhosis with an increase in maximum plasma concentration (Cmax ) of 11.50 and 2.89 times, respectively, compared with noncirrhotic livers. No major differences were observed for metformin and furosemide. Interaction of rosuvastatin or digoxin with perpetrator drugs were more pronounced in noncirrhotic livers compared with cirrhotic livers. Our results demonstrated that NMP of human diseased explanted livers is an excellent model to assess hepatic extraction, clearance, biliary excretion, and DDI. Gaining insight into pharmacokinetic profiles of OATP1B1/1B3, P-gp, BCRP, and OCT1 model compounds is a first step toward studying transporter functions in diseased livers.
Asunto(s)
Furosemida , Metformina , Humanos , Rosuvastatina Cálcica/farmacocinética , Furosemida/farmacocinética , Eliminación Hepatobiliar , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Hígado/metabolismo , Cirrosis Hepática , Metformina/farmacocinética , Digoxina/farmacocinética , Interacciones FarmacológicasRESUMEN
The prevalence of sarcopenia is increasing while it is often challenging, expensive and time-consuming to test the effectiveness of interventions against sarcopenia. Translational mouse models that adequately mimic underlying physiological pathways could accelerate research but are scarce. Here, we investigated the translational value of three potential mouse models for sarcopenia, namely partial immobilized (to mimic sedentary lifestyle), caloric restricted (CR; to mimic malnutrition) and a combination (immobilized & CR) model. C57BL/6J mice were calorically restricted (-40%) and/or one hindleg was immobilized for two weeks to induce loss of muscle mass and function. Muscle parameters were compared to those of young control (4 months) and old reference mice (21 months). Transcriptome analysis of quadriceps muscle was performed to identify underlying pathways and were compared with those being expressed in aged human vastus lateralis muscle-biopsies using a meta-analysis of five different human studies. Caloric restriction induced overall loss of lean body mass (-15%, p<0.001), whereas immobilization decreased muscle strength (-28%, p<0.001) and muscle mass of hindleg muscles specifically (on average -25%, p<0.001). The proportion of slow myofibers increased with aging in mice (+5%, p<0.05), and this was not recapitulated by the CR and/or immobilization models. The diameter of fast myofibers decreased with aging (-7%, p<0.05), and this was mimicked by all models. Transcriptome analysis revealed that the combination of CR and immobilization recapitulated more pathways characteristic for human muscle-aging (73%) than naturally aged (21 months old) mice (45%). In conclusion, the combination model exhibits loss of both muscle mass (due to CR) and function (due to immobilization) and has a remarkable similarity with pathways underlying human sarcopenia. These findings underline that external factors such as sedentary behavior and malnutrition are key elements of a translational mouse model and favor the combination model as a rapid model for testing the treatments against sarcopenia.
RESUMEN
The zebrafish has been shown to be an excellent vertebrate model for studying the roles of specific genes and signaling pathways. The sequencing of its genome and the relative ease with which gene modifications can be performed have led to the creation of numerous human disease models that can be used for testing the potential and the toxicity of new pharmaceutical compounds. Many pharmaceutical companies already use the zebrafish for prescreening purposes. So far, the focus has been on ecotoxicity and the effects on embryonic development, but there is a trend to expand the use of the zebrafish with acute, subchronic, and chronic toxicity studies that are currently still carried out with the more conventional test animals such as rodents. However, before we can fully realize the potential of the zebrafish as an animal model for understanding human development, disease, and toxicology, we must first greatly advance our knowledge of normal zebrafish physiology, anatomy, and histology. To further this knowledge, we describe, in the present article, location and histology of the major zebrafish organ systems with a brief description of their function.
Asunto(s)
Modelos Animales , Pez Cebra/anatomía & histología , AnimalesRESUMEN
Non-alcoholic steatohepatitis (NASH) is the most rapidly growing liver disease that is nevertheless without approved pharmacological treatment. Despite great effort in developing novel NASH therapeutics, many have failed in clinical trials. This has raised questions on the adequacy of preclinical models. Elafibranor is one of the drugs currently in late stage development which had mixed results for phase 2/interim phase 3 trials. In the current study we investigated the response of elafibranor in APOE*3Leiden.CETP mice, a translational animal model that displays histopathological characteristics of NASH in the context of obesity, insulin resistance and hyperlipidemia. To induce NASH, mice were fed a high fat and cholesterol (HFC) diet for 15 weeks (HFC reference group) or 25 weeks (HFC control group) or the HFC diet supplemented with elafibranor (15 mg/kg/d) from week 15-25 (elafibranor group). The effects on plasma parameters and NASH histopathology were assessed and hepatic transcriptome analysis was used to investigate the underlying pathways affected by elafibranor. Elafibranor treatment significantly reduced steatosis and hepatic inflammation and precluded the progression of fibrosis. The underlying disease pathways of the model were compared with those of NASH patients and illustrated substantial similarity with molecular pathways involved, with 87% recapitulation of human pathways in mice. We compared the response of elafibranor in the mice to the response in human patients and discuss potential pitfalls when translating preclinical results of novel NASH therapeutics to human patients. When taking into account that due to species differences the response to some targets, like PPAR-α, may be overrepresented in animal models, we conclude that elafibranor may be particularly useful to reduce hepatic inflammation and could be a pharmacologically useful agent for human NASH, but probably in combination with other agents.
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Chalconas/administración & dosificación , Cirrosis Hepática/prevención & control , Síndrome Metabólico/prevención & control , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Obesidad/prevención & control , Propionatos/administración & dosificación , Animales , Glucemia/análisis , Proteínas de Transferencia de Ésteres de Colesterol/genética , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Humanos , Hígado/metabolismo , Hígado/patología , Cirrosis Hepática/genética , Masculino , Síndrome Metabólico/genética , Ratones , Ratones Transgénicos , Enfermedad del Hígado Graso no Alcohólico/sangre , Enfermedad del Hígado Graso no Alcohólico/etiología , Enfermedad del Hígado Graso no Alcohólico/genética , Obesidad/genética , PPAR alfa/antagonistas & inhibidores , Transcriptoma/efectos de los fármacos , Transcriptoma/genética , Resultado del TratamientoRESUMEN
BACKGROUND: Non-alcoholic steatohepatitis (NASH) has become one of the most common liver diseases and is still without approved pharmacotherapy. Lifestyle interventions using exercise and diet change remain the current treatment of choice and even a small weight loss (5-7%) can already have a beneficial effect on NASH. However, the underlying molecular mechanisms of exercise and diet interventions remain largely elusive, and it is unclear whether they exert their health effects via similar or different pathways. METHODS: Ldlr-/-.Leiden mice received a high fat diet (HFD) for 30â¯weeks to establish a severe state of NASH/fibrosis with simultaneous atherosclerosis development. Groups of mice were then either left untreated (control group) or were treated for 20â¯weeks with exercise (running wheel), diet change (switch to a low fat chow diet) or the combination thereof. The liver and distant organs including heart, white adipose tissue (WAT) and muscle were histologically examined. Comprehensive transcriptome analysis of liver, WAT and muscle revealed the organ-specific effects of exercise and diet and defined the underlying pathways. RESULTS: Exercise and dietary change significantly reduced body weight, fat mass, adipocyte size and improved myosteatosis and muscle function with additive effects of combination treatment. WAT inflammation was significantly improved by diet change, tended to be reduced with exercise, and combination therapy had no additive effect. Hepatic steatosis and inflammation were almost fully reversed by exercise and diet change, while hepatic fibrosis tended to be improved with exercise and was significantly improved with diet change. Additive effects for the combination therapy were shown for liver steatosis and associated liver lipids, and atherosclerosis, but not for hepatic inflammation and fibrosis. Pathway analysis revealed complementary effects on metabolic pathways and lipid handling processes, thereby substantiating the added value of combined lifestyle treatment. CONCLUSIONS: Exercise, diet change and the combination thereof can reverse established NASH/fibrosis in obese Ldlr-/-.Leiden mice. In addition, the lifestyle interventions had beneficial effects on atherosclerosis, WAT inflammation and muscle function. For steatosis and other parameters related to adiposity or lipid metabolism, exercise and dietary change affected more distinct pathways that acted complementary when the interventions were combined resulting in an additive effect for the combination therapy on important endpoints including NASH and atherosclerosis. For inflammation, exercise and diet change shared several underlying pathways resulting in a net similar effect when the interventions were combined.
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Dieta con Restricción de Grasas , Cirrosis Hepática/terapia , Enfermedad del Hígado Graso no Alcohólico/terapia , Condicionamiento Físico Animal/fisiología , Receptores de LDL/genética , Transducción de Señal/fisiología , Tejido Adiposo Blanco/metabolismo , Tejido Adiposo Blanco/patología , Animales , Aterosclerosis/dietoterapia , Aterosclerosis/genética , Aterosclerosis/patología , Aterosclerosis/terapia , Dieta Alta en Grasa , Metabolismo de los Lípidos , Hígado/metabolismo , Hígado/patología , Cirrosis Hepática/dietoterapia , Cirrosis Hepática/patología , Ratones , Ratones Noqueados , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Enfermedad del Hígado Graso no Alcohólico/dietoterapia , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/patología , Receptores de LDL/metabolismoRESUMEN
Non-alcoholic steatohepatitis (NASH) is a fast-growing liver disorder that is associated with an increased incidence of cardiovascular disease and type 2 diabetes. Animal models adequately mimicking this condition are scarce. We herein investigate whether Ldlr-/-. Leiden mice on different high-fat diets represent a suitable NASH model. Ldlr-/-. Leiden mice were fed a healthy chow diet or fed a high-fat diet (HFD) containing lard or a fast food diet (FFD) containing milk fat. Additionally, the response to treatment with obeticholic acid (OCA) was evaluated. Both high-fat diets induced obesity, hyperlipidemia, hyperinsulinemia, and increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Mice on both diets developed progressive macro- and microvesicular steatosis, hepatic inflammation, and fibrosis, along with atherosclerosis. HFD induced more severe hyperinsulinemia, while FFD induced more severe hepatic inflammation with advanced (F3) bridging fibrosis, as well as more severe atherosclerosis. OCA treatment significantly reduced hepatic inflammation and fibrosis, and it did not affect atherosclerosis. Hepatic transcriptome analysis was compared with human NASH and illustrated similarity. The present study defines a translational model of NASH with progressive liver fibrosis and simultaneous atherosclerosis development. By adaptation of the fat content of the diet, either insulin resistance (HFD) or hepatic inflammation and fibrosis (FFD) can be aggravated.
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Aterosclerosis/sangre , Aterosclerosis/etiología , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Comida Rápida/efectos adversos , Cirrosis Hepática/sangre , Cirrosis Hepática/etiología , Enfermedad del Hígado Graso no Alcohólico/sangre , Enfermedad del Hígado Graso no Alcohólico/etiología , Animales , Aterosclerosis/tratamiento farmacológico , Aterosclerosis/genética , Ácido Quenodesoxicólico/análogos & derivados , Ácido Quenodesoxicólico/uso terapéutico , Hiperinsulinismo/tratamiento farmacológico , Hiperinsulinismo/etiología , Hiperlipidemias/tratamiento farmacológico , Hiperlipidemias/etiología , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/genética , Obesidad/sangre , Obesidad/tratamiento farmacológico , Obesidad/etiología , Receptores de LDL/genética , Transcriptoma , Resultado del TratamientoRESUMEN
BACKGROUND: There is a lack of predictive preclinical animal models combining atherosclerosis and type 2 diabetes. APOE∗3-Leiden (E3L) mice are a well-established model for diet-induced hyperlipidemia and atherosclerosis, and glucokinase+/- (GK+/-) mice are a translatable disease model for glucose control in type 2 diabetes. The respective mice respond similarly to lipid-lowering and antidiabetic drugs as humans. The objective of this study was to evaluate/characterize the APOE∗3-Leiden.glucokinase+/- (E3L.GK+/-) mouse as a novel disease model to study the metabolic syndrome and diabetic complications. METHODS: Female E3L.GK+/-, E3L, and GK+/- mice were fed fat- and cholesterol-containing diets for 37 weeks, and plasma parameters were measured throughout. Development of diabetic macro- and microvascular complications was evaluated. RESULTS: Cholesterol and triglyceride levels were significantly elevated in E3L and E3L.GK+/- mice compared to GK+/- mice, whereas fasting glucose was significantly increased in E3L.GK+/- and GK+/- mice compared to E3L. Atherosclerotic lesion size was increased 2.2-fold in E3L.GK+/- mice as compared to E3L (p = 0.037), which was predicted by glucose exposure (R 2 = 0.636, p = 0.001). E3L and E3L.GK+/- mice developed NASH with severe inflammation and fibrosis which, however, was not altered by introduction of the defective GK phenotype, whereas mild kidney pathology with tubular vacuolization was present in all three phenotypes. CONCLUSIONS: We conclude that the E3L.GK+/- mouse is a promising novel diet-inducible disease model for investigation of the etiology and evaluation of drug treatment on diabetic atherosclerosis.
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Apolipoproteína E3/genética , Aterosclerosis/genética , Complicaciones de la Diabetes/genética , Diabetes Mellitus Tipo 2/genética , Modelos Animales de Enfermedad , Dislipidemias/genética , Animales , Aterosclerosis/sangre , Glucemia/metabolismo , Colesterol/sangre , Complicaciones de la Diabetes/sangre , Diabetes Mellitus Tipo 2/sangre , Dislipidemias/sangre , Femenino , Heterocigoto , Inflamación , Lípidos/sangre , Ratones , Ratones Noqueados , Fenotipo , Riesgo , Investigación Biomédica Traslacional , Triglicéridos/metabolismoRESUMEN
Calorie restriction (CR) is a dietary regimen that supports healthy aging. In this study, we investigated the systemic and liver-specific responses caused by a diet switch to a medium-fat (MF) diet in 24-month-old lifelong, CR-exposed mice. This study aimed to increase the knowledge base on dietary alterations of gerontological relevance. Nine-week-old C57BL/6J mice were exposed either to a control, CR, or MF diet. At the age of 24 months, a subset of mice of the CR group was transferred to ad libitumMF feeding (CR-MF). The mice were sacrificed at the age of 28 months, and then, biochemical and molecular analyses were performed. Our results showed that, despite the long-term exposure to the CR regimen, mice in the CR-MF group displayed hyperphagia, rapid weight gain, and hepatic steatosis. However, no hepatic fibrosis/injury or alteration in CR-improved survival was observed in the diet switch group. The liver transcriptomic profile of CR-MF mice largely shifted to a profile similar to the MF-fed animals but leaving ~22% of the 1,578 differentially regulated genes between the CR and MF diet groups comparable with the expression of the lifelong CR group. Therefore, although the diet switch was performed at an old age, the CR-MF-exposed mice showed plasticity in coping with the challenge of a MF diet without developing severe liver pathologies.
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Restricción Calórica/métodos , Metilación de ADN/genética , Transcriptoma/genética , Envejecimiento , Animales , Dieta , Grasas de la Dieta , Humanos , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
SCOPE: Calorie restriction (CR) has been shown to extend life- and health-span in model species. For most humans, a life-long CR diet is too arduous to adhere to. The aim of this study was to explore whether weekly intermittent CR can (1) provide long-term beneficial effects and (2) counteract diet-induced obesity in male aging mice. METHODS AND RESULTS: In this study, we have exposed C57Bl/6J mice for 24 months to an intermittent (INT) diet, alternating weekly between CR of a control diet and ad libitum moderate-fat (MF) feeding. This weekly intermittent CR significantly counteracted the adverse effects of the MF diet on mortality, body weight, and liver health markers in 24-month-old male mice. Hepatic gene expression profiles of INT-exposed animals appeared much more comparable to CR- than to MF-exposed mice. At 12 months of age, a subgroup of MF-exposed mice was transferred to the INT diet. Gene expression profiles in the liver of the 24-month-old diet switch mice were highly similar to the INT-exposed mice. However, a small subset of genes was consistently changed by the MF diet during the first phase of life. CONCLUSION: Weekly intermittent CR largely, but not completely, reversed adverse effects caused by a MF diet.
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Envejecimiento , Restricción Calórica/métodos , Dieta , Animales , Composición Corporal , Peso Corporal , Biología Computacional , Citocinas/sangre , Grasas de la Dieta/administración & dosificación , Insulina/sangre , Masculino , Ratones , Ratones Endogámicos C57BL , Obesidad/prevención & control , Análisis de Componente Principal , Triglicéridos/sangreRESUMEN
In recent years, a number of proteins have been identified that can modify the activities of the Wilms' Tumor 1 (WT1) proteins. One of these modifiers is the p53 protein. To investigate a genetic interaction between the p53 gene and the wt1 gene, we have crossed their respective knockout mice. The absence of p53 appears to have no gross effect on the phenotype of wt1-null mice. Both wt1-null and double-null embryos develop pericardial bleeding and die in utero. In adult p53-null mice, wt1-heterozygosity (wt1het) predisposes to an earlier onset of lymphomagenesis and the development of kidney abnormalities resembling oncocytoma in humans. wt1-heterozygosity alone predisposes to the development of glomerular sclerosis.
Asunto(s)
Genes del Tumor de Wilms/fisiología , Genes p53/genética , Proteínas WT1/genética , Adenoma Oxifílico/genética , Animales , Femenino , Glomérulos Renales/patología , Linfoma/genética , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Esclerosis/genética , Neoplasias del Timo/genética , Proteína p53 Supresora de Tumor/deficiencia , Proteína p53 Supresora de Tumor/genética , Proteínas WT1/deficienciaRESUMEN
BACKGROUND AND AIMS: The recently developed histological scoring system for non-alcoholic fatty liver disease (NAFLD) by the NASH Clinical Research Network (NASH-CRN) has been widely used in clinical settings, but is increasingly employed in preclinical research as well. However, it has not been systematically analyzed whether the human scoring system can directly be converted to preclinical rodent models. To analyze this, we systematically compared human NAFLD liver pathology, using human liver biopsies, with liver pathology of several NAFLD mouse models. Based upon the features pertaining to mouse NAFLD, we aimed at establishing a modified generic scoring system that is applicable to broad spectrum of rodent models. METHODS: The histopathology of NAFLD was analyzed in several different mouse models of NAFLD to define generic criteria for histological assessment (preclinical scoring system). For validation of this scoring system, 36 slides of mouse livers, covering the whole spectrum of NAFLD, were blindly analyzed by ten observers. Additionally, the livers were blindly scored by one observer during two separate assessments longer than 3 months apart. RESULTS: The criteria macrovesicular steatosis, microvesicular steatosis, hepatocellular hypertrophy, inflammation and fibrosis were generally applicable to rodent NAFLD. The inter-observer reproducibility (evaluated using the Intraclass Correlation Coefficient) between the ten observers was high for the analysis of macrovesicular steatosis and microvesicular steatosis (ICCâ=â0.784 and 0.776, all p<0.001, respectively) and moderate for the analysis of hypertrophy and inflammation (ICCâ=â0.685 and 0.650, all p<0.001, respectively). The intra-observer reproducibility between the different observations of one observer was high for the analysis of macrovesicular steatosis, microvesicular steatosis and hypertrophy (ICCâ=â0.871, 0.871 and 0.896, all p<0.001, respectively) and very high for the analysis of inflammation (ICCâ=â0.931, p<0.001). CONCLUSIONS: We established a simple NAFLD scoring system with high reproducibility that is applicable for different rodent models and for all stages of NAFLD etiology.
Asunto(s)
Hígado/patología , Enfermedad del Hígado Graso no Alcohólico/patología , Animales , Modelos Animales de Enfermedad , Femenino , Hepatomegalia/patología , Técnicas Histológicas , Humanos , Inflamación/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Reproducibilidad de los Resultados , Índice de Severidad de la EnfermedadRESUMEN
The kidney has a high capacity to regenerate after ischemic injury via several mechanisms, one of which involves bone marrow-derived (stem) cells. The ATP binding cassette transporters, P-glycoprotein and breast cancer resistance protein, are determinants for the enriched stem and progenitor cell fraction in bone marrow. Because they are upregulated after acute kidney injury, we hypothesized that both efflux pumps may play a role in protecting against renal injury. Surprisingly, transporter-deficient mice were protected against ischemia-induced renal injury. To further study this, bone marrow from irradiated wild-type mice was reconstituted by bone marrow from wild-type, P-glycoprotein- or breast cancer resistance protein-deficient mice. Four weeks later, kidney injury was induced and its function evaluated. Significantly more bone marrow-derived cells were detected in kidneys grafted with transporter-deficient bone marrow. A gender mismatch study suggested that cell fusion of resident tubular cells with bone marrow cells was unlikely. Renal function analyses indicated an absence of renal damage following ischemia-reperfusion in animals transplanted with transporter-deficient bone marrow. When wild-type bone marrow was transplanted in breast cancer resistance protein-deficient mice this protection is lost. Furthermore, we demonstrate that transporter-deficient bone marrow contained significantly more monocytes, granulocytes, and early outgrowth endothelial progenitor cells.
Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/deficiencia , Transportadoras de Casetes de Unión a ATP/metabolismo , Lesión Renal Aguda/metabolismo , Riñón/metabolismo , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Lesión Renal Aguda/sangre , Lesión Renal Aguda/orina , Animales , Células de la Médula Ósea/metabolismo , Trasplante de Médula Ósea , Femenino , Humanos , Isquemia/metabolismo , Riñón/irrigación sanguínea , Pruebas de Función Renal , Ratones , Ratones Noqueados , Daño por Reperfusión/metabolismo , Transducción GenéticaRESUMEN
Renal malformations are common human birth defects that sometimes occur in the context of the caudal regression syndrome. Here, we found that exposure of pregnant mice to all-trans retinoic acid, at a time when the metanephros has yet to form, causes a failure of kidney development along with caudal regression. Maternal treatment with Am580 (retinoic acid receptor alpha agonist) also induced similar patterns of kidney maldevelopment in the fetus. In metanephroi from retinoic acid-treated pregnancies, renal mesenchyme condensed around the ureteric bud but then failed to differentiate into nephrons, instead undergoing involution by fulminant apoptosis to produce a renal agenesis phenotype. Results of whole organ cultures in serum-free medium, and also tissue recombination experiments, showed that the nephrogenic defect was intrinsic to the kidney and that it resided in the metanephric mesenchyme and not the ureteric bud. Renal mesenchyme from control embryos expressed Wilms' tumor 1 (Wt1), but this transcription factor, which is indispensable for kidney development, failed to express in metanephroi of retinoic acid-exposed embryos. Wt1 expression and organogenesis were both restored, however, when metanephroi from retinoic acid-treated pregnancies were grown in serum-containing media. Our data illuminate the pathobiology of a severe, teratogen-induced kidney malformation.
Asunto(s)
Anomalías Múltiples/inducido químicamente , Canal Anal/anomalías , Genes del Tumor de Wilms , Riñón/anomalías , Riñón/embriología , Vértebras Lumbares/anomalías , Médula Espinal/anomalías , Tretinoina , Animales , Técnicas de Cocultivo , Anomalías Congénitas/embriología , Anomalías Congénitas/genética , Anomalías Congénitas/patología , Desarrollo Embrionario/genética , Femenino , Expresión Génica , Riñón/patología , Mesodermo/metabolismo , Ratones , Ratones Endogámicos ICR , Síndrome , Técnicas de Cultivo de TejidosRESUMEN
Glomerular disease is one of the most common causes of end-stage renal failure. Increasing evidence suggests that these glomerulopathies are frequently caused by primary lesions in the renal podocytes. One of the major consequences of podocyte lesions is the accumulation of mesangial matrix in the glomerular basement membrane, a process called glomerulosclerosis. Mesangial sclerosis is one of the most consistent findings in Denys-Drash patients and can be caused by dominant mutations in the Wilms' tumor 1 gene (WT1). The underlying mechanism, however, is poorly understood. WT1 is expressed in the podocytes throughout life, but its function in this cell type is unknown. Combining Wt1-knockout and inducible yeast artificial chromosome transgenic mouse models, we demonstrate that reduced expression levels of WT1 result in either crescentic glomerulonephritis or mesangial sclerosis depending on the gene dosage. Strikingly, the two podocyte-specific genes nphs1 and podocalyxin are dramatically downregulated in mice with decreased levels of Wt1, suggesting that these two genes act downstream of Wt1. Taken together, our data provide genetic evidence that reduced levels of Wt1 are responsible for the pathogenesis of two distinct renal diseases and offer a molecular explanation for the increased occurrence of glomerulosclerosis in patients with WAGR syndrome.
Asunto(s)
Mesangio Glomerular/metabolismo , Glomerulonefritis/metabolismo , Glomeruloesclerosis Focal y Segmentaria/metabolismo , Enfermedades Renales/metabolismo , Glomérulos Renales/patología , Proteínas WT1/metabolismo , Animales , Regulación hacia Abajo , Mesangio Glomerular/patología , Glomerulonefritis/patología , Glomeruloesclerosis Focal y Segmentaria/patología , Humanos , Enfermedades Renales/patología , Proteínas de la Membrana , Ratones , Ratones Noqueados , Proteínas/metabolismo , Esclerosis , Sialoglicoproteínas/metabolismo , Proteínas WT1/genéticaRESUMEN
In the present study, it is shown that mice heterozygous for wt1 develop glomerular sclerosis and the nature and time course of events leading to the glomerular scarring are determined. Wt1-heterozygous (wt1het) mice and their wild-type littermates were closely monitored from birth and plasma levels of urea, creatinine, and albumin were compared with histological data and clinical features. One of the first indications of nephropathy in the wt1het mouse was the development of proteinuria, accompanied by progressive elevation of the plasma levels of urea and creatinine. Subsequently, the mice developed albuminuria, which correlated with thickening of the glomerular basement membrane and fusion of the podocyte foot processes. Glomerulosclerosis was a relatively late event, accompanied by severe albuminuria and loss of WT1, nephrin, CD2AP, and alpha-actinin-4.