RESUMEN

Background: Assessing and evaluating health care is important, and an abundance of instruments are developed in different languages. Translating existing, validated instruments is demanding and calls for adherence to protocol. Purpose: The purpose of this study was to translate and culturally adapt the FAMCARE-2 scale for use in Sweden. Methods: Traditional back-translation and the decentering stance were utilized and assessed. Experts in palliative care clinic and research were involved; the FAMCARE-2 instrument was discussed with family caregivers and content validity was assessed by experienced health professionals. Results: Significant discrepancies were not revealed by back-translation. Using the decentering stance gave reliable structure and opportunities for reflection throughout the translation process. Discussion: Translating an existing instrument into a second language requires interpretation and adaptation more than a naive translation. The back-translation process may be enhanced if the decentering stance is adopted.

RESUMEN

OBJECTIVE: Previous studies have indicated that the hyperlipidemia and gene expression changes induced by a short-term high-fat diet (HFD) are mediated through the peroxisome proliferator-activated receptor gamma coactivator (PGC)-1beta, and that in vitro both PGC-1beta and PGC -1alpha increase PPARalpha-mediated transcriptional activities. Here, we examined the in vivo effects of these two coactivators in potentiating the lipid lowering properties of the PPARalpha agonist Wy14,643 (Wy). METHODS AND RESULTS: C57BL/6 mice were fed chow or HFD and transduced with adenoviruses encoding PGC-1alpha or PGC-1beta. On chow, hepatic PGC-1beta overexpression caused severe combined hyperlipidemia including elevated plasma apolipoprotein B levels. Hepatic triglyceride secretion, DGAT1, and FAT/CD36 expression were increased whereas PPARalpha and hepatic lipase mRNA levels were reduced. PGC-1beta overexpression blunted Wy-mediated changes in expression levels of PPARalpha and downstream genes. Furthermore, PGC-1beta did not potentiate Wy-stimulated fatty acid oxidation in primary hepatocytes. PGC-1beta and PGC-1alpha overexpression did not alter SREBP-1c, SREBP-1c target gene expression, nor hepatic triglyceride content. On HFD, PGC-1beta overexpression decreased hepatic SREBP-1c, yet increased FAS and ACCalpha mRNA and plasma triglyceride levels. CONCLUSIONS: Hepatic PGC-1beta overexpression caused combined hyperlipidemia independent of SREBP-1c activation. Hepatic PGC-1beta overexpression reduced the potentially beneficial effects of PPARalpha activation on gene expression. Thus, inhibition of hepatic PGC-1beta may provide a therapy for treating combined hyperlipidemia.

Asunto(s)

Anticolesterolemiantes/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Hiperlipidemia Familiar Combinada/prevención & control , Hígado/efectos de los fármacos , PPAR alfa/agonistas , Pirimidinas/farmacología , Transactivadores/metabolismo , Acetil-CoA Carboxilasa/metabolismo , Adenoviridae/genética , Animales , Anticolesterolemiantes/uso terapéutico , Apolipoproteínas B/sangre , Antígenos CD36/metabolismo , Células Cultivadas , Diacilglicerol O-Acetiltransferasa/metabolismo , Grasas de la Dieta/administración & dosificación , Modelos Animales de Enfermedad , Ácido Graso Sintasas/metabolismo , Ácidos Grasos/metabolismo , Vectores Genéticos , Hiperlipidemia Familiar Combinada/genética , Hiperlipidemia Familiar Combinada/metabolismo , Lipasa/metabolismo , Metabolismo de los Lípidos/efectos de los fármacos , Metabolismo de los Lípidos/genética , Hígado/metabolismo , Ratones , Ratones Endogámicos C57BL , PPAR alfa/metabolismo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma , Pirimidinas/uso terapéutico , ARN Mensajero/metabolismo , Receptores de Lipoproteína/metabolismo , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Transactivadores/genética , Factores de Transcripción , Transducción Genética , Triglicéridos/metabolismo , Regulación hacia Arriba

RESUMEN

OBJECTIVE: Growth hormone (GH) enhances lipolysis in adipose tissue, thereby increasing the flux of fatty acids to other tissues. Moreover, GH increases hepatic triglyceride synthesis and secretion in rats and decreases the action of peroxisome proliferator-activated receptor (PPAR)alpha. PPARalpha is activated by fatty acids and regulates hepatic lipid metabolism in rodents. The aim of this study was to investigate the importance of PPARalpha for the effects of GH on hepatic gene expression and lipoprotein metabolism. DESIGN: Bovine GH was given as a continuous infusion (5mg/kg/day) for 7 days to PPARalpha-null and wild-type (wt) mice. Plasma and liver lipids and hepatic gene expression were measured. In separate experiments, hepatic triglyceride secretion was measured. RESULTS: GH treatment decreased hepatic triglyceride content and increased hepatic triglyceride secretion rate and serum cholesterol levels. Furthermore, GH increased hepatic acylCoA:diacylglycerol acyltransferase (DGAT)2 mRNA levels, but decreased the hepatic mRNA expression of acyl-CoA oxidase, medium-chain acyl-CoA dehydrogenase and PPARgamma1. All these GH effects were independent of PPARalpha. However, the effect of GH on Cyp4a10, PPARgamma2, and DGAT1 was different between the genotypes. GH treatment decreased Cyp4a10 mRNA expression in wt mice, but increased the expression in PPARalpha-null mice. In contrast, GH decreased the expression of DGAT1 and PPARgamma2 in PPARalpha-null mice, but not in wt mice. CONCLUSIONS: Most of the effects of GH on lipid and lipoprotein metabolism were independent of PPARalpha. However, GH had unique effects on Cyp4a10, DGAT1, and PPARgamma2 gene expression in PPARalpha-null mice showing cross-talk between GH and PPARalpha signalling in vivo.

Asunto(s)

Expresión Génica/efectos de los fármacos , Hormona del Crecimiento/farmacología , Metabolismo de los Lípidos/efectos de los fármacos , Lipoproteínas VLDL/metabolismo , Hígado/metabolismo , PPAR alfa/fisiología , Animales , Peso Corporal/efectos de los fármacos , Sistema Enzimático del Citocromo P-450/genética , Diacilglicerol O-Acetiltransferasa/genética , Ácidos Grasos/metabolismo , Femenino , Factor I del Crecimiento Similar a la Insulina/metabolismo , Metabolismo de los Lípidos/genética , Lípidos/sangre , Hígado/efectos de los fármacos , Masculino , Ratones , Ratones Mutantes , Oxidación-Reducción , PPAR alfa/genética , PPAR gamma/genética , ARN Mensajero/análisis , ARN Mensajero/metabolismo , Factores Sexuales , Triglicéridos/análisis , Triglicéridos/metabolismo

RESUMEN

Epigallocatechin gallate (EGCG) increases the formation of cytosolic lipid droplets by a mechanism that is independent of the rate of triglyceride biosynthesis and involves an enhanced fusion between lipid droplets, a process that is crucial for their growth in size. EGCG treatment reduced the secretion of both triglycerides and apolipoprotein B-100 (apoB-100) VLDLs but not of transferrin, albumin, or total proteins, indicating that EGCG diverts triglycerides from VLDL assembly to storage in the cytosol. This is further supported by the observed increase in both intracellular degradation of apoB-100 and ubiquitination of the protein (indicative of increased proteasomal degradation) in EGCG-treated cells. EGCG did not interfere with the microsomal triglyceride transfer protein, and the effect of EGCG on the secretion of VLDLs was found to be independent of the LDL receptor. Thus, our results indicate that EGCG promotes the accumulation of triglycerides in cytosolic lipid droplets, thereby diverting lipids from the assembly of VLDL to storage in the cytosol. Our results also indicate that the accumulation of lipids in the cytosol is not always associated with increased secretion of VLDL.

Asunto(s)

Apolipoproteínas B/metabolismo , Catequina/análogos & derivados , Metabolismo de los Lípidos/efectos de los fármacos , Lipoproteínas VLDL/metabolismo , Adipocitos/efectos de los fármacos , Adipocitos/metabolismo , Animales , Apolipoproteína B-100 , Apolipoproteínas B/genética , Secuencia de Bases , Catequina/farmacología , Línea Celular , Citosol/efectos de los fármacos , Citosol/metabolismo , ADN Complementario/genética , Heparina/farmacología , Humanos , Lípidos/sangre , Lipoproteínas/sangre , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Transgénicos , Células 3T3 NIH , Perilipina-2 , Ratas , Receptores de LDL/efectos de los fármacos , Receptores de LDL/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo

RESUMEN

We have previously shown that growth hormone (GH) overexpression in the brain increased food intake, accompanied with increased hypothalamic agouti-related protein (AgRP) expression. Ghrelin, which stimulates both appetite and GH secretion, was injected intracerebroventricularly to GHR-/- and littermate control (+/+) mice to determine whether ghrelin's acute effects on appetite are dependent on GHR signaling. GHR-/- mice were also analyzed with respect to serum levels of lipoproteins, apolipoprotein (apo)B, leptin, glucose, and insulin as well as body composition. Central injection of ghrelin into the third dorsal ventricle increased food consumption in +/+ mice, whereas no change was observed in GHR-/- mice. After ghrelin injection, AgRP mRNA expression in the hypothalamus was higher in +/+ littermates than in GHR-/- mice, indicating a possible importance of AgRP in the GHR-mediated effect of ghrelin. Compared with controls, GHR-/- mice had increased food intake, leptin levels, and total and intra-abdominal fat mass per body weight and deceased lean mass. Moreover, serum levels of triglycerides, LDL and HDL cholesterol, and apoB, as well as glucose and insulin levels were lower in the GHR-/- mice. In summary, ghrelin's acute central action to increase food intake requires functionally intact GHR signaling. Long-term GHR deficiency in mice is associated with high plasma leptin levels, obesity, and increased food intake but a marked decrease in all lipoprotein fractions.

Asunto(s)

Conducta Alimentaria/efectos de los fármacos , Hipolipoproteinemias/inducido químicamente , Hipolipoproteinemias/fisiopatología , Obesidad/inducido químicamente , Obesidad/fisiopatología , Hormonas Peptídicas/administración & dosificación , Receptores de Somatotropina/deficiencia , Animales , Peso Corporal/efectos de los fármacos , Femenino , Ghrelina , Inyecciones , Masculino , Ratones , Ratones Noqueados

RESUMEN

Adipose differentiation-related protein (ADRP) is a lipid droplet-associated protein that is expressed in various tissues. In mice treated with the peroxisome proliferator-activated receptor alpha (PPARalpha) agonist Wy14,643 (Wy), hepatic mRNA and protein levels of ADRP as well as hepatic triglyceride content increased. Also in primary mouse hepatocytes, Wy increased ADRP expression and intracellular triglyceride mass. The triglyceride mass increased in spite of unchanged triglyceride biosynthesis and increased palmitic acid oxidation. However, Wy incubation decreased the secretion of newly synthesized triglycerides, whereas apolipoprotein B secretion increased. Thus, decreased availability of triglycerides for VLDL assembly could help to explain the cellular accumulation of triglycerides after Wy treatment. We hypothesized that this effect could be mediated by increased ADRP expression. Similar to PPARalpha activation, adenovirus-mediated ADRP overexpression in mouse hepatocytes enhanced cellular triglyceride mass and decreased the secretion of newly synthesized triglycerides. In ADRP-overexpressing cells, Wy incubation resulted in a further decrease in triglyceride secretion. This effect of Wy was not attributable to decreased cellular triglycerides after increased fatty acid oxidation because the triglyceride mass in Wy-treated ADRP-overexpressing cells was unchanged. In summary, PPARalpha activation prevents the availability of triglycerides for VLDL assembly and increases hepatic triglyceride content in part by increasing the expression of ADRP.

Asunto(s)

Hepatocitos/metabolismo , Proteínas de la Membrana/metabolismo , PPAR alfa/metabolismo , Triglicéridos/metabolismo , Acil-CoA Deshidrogenasa de Cadena Larga/genética , Acil-CoA Oxidasa/genética , Animales , Apolipoproteína B-100 , Apolipoproteína B-48 , Apolipoproteínas B/metabolismo , Carnitina O-Palmitoiltransferasa/genética , Grasas de la Dieta/administración & dosificación , Grasas de la Dieta/farmacología , Expresión Génica/efectos de los fármacos , Expresión Génica/genética , Hepatocitos/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Oxidación-Reducción , PPAR alfa/antagonistas & inhibidores , PPAR alfa/genética , Ácido Palmítico/metabolismo , Perilipina-2 , Proliferadores de Peroxisomas/farmacología , Pirimidinas/farmacología , Transfección , Triglicéridos/biosíntesis

RESUMEN

Hepatic PPARgamma expression is increased in several animal models of diabetes and obesity, and liver-specific overexpression of PPARgamma induces liver steatosis. The aim of this study was to investigate the regulation of PPARgamma expression in primary mouse hepatocytes. PPARgamma2, but not PPARgamma1, was up-regulated by insulin and to a lesser extent by oleic acid. Insulin increased transcription of the PPARgamma2 gene via phosphatidylinositol 3-kinase activation. The PPARgamma agonist, rosiglitazone, increased PPARgamma2 expression, but not PPARgamma1, only in the presence of insulin. Also aP2 mRNA expression was induced by rosiglitazone to a higher degree in the presence of insulin, while acyl-CoA oxidase was increased independently of insulin. In summary, PPARgamma2 is increased in hepatocytes by oleic acid and insulin. These results may help to understand the regulation of PPARgamma expression in liver, which possibly plays a role in the development of liver steatosis.

Asunto(s)

Hepatocitos/metabolismo , Insulina/administración & dosificación , Ácido Oléico/administración & dosificación , PPAR gamma/metabolismo , Tiazolidinedionas/administración & dosificación , Animales , Células Cultivadas , Relación Dosis-Respuesta a Droga , Regulación de la Expresión Génica/efectos de los fármacos , Hepatocitos/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Rosiglitazona , Activación Transcripcional/efectos de los fármacos

RESUMEN

Human growth hormone (GH) excess is linked to increased cardiovascular morbidity and mortality. However, little is known about the effect of GH excess on atherosclerosis. We developed a new mouse model to assess the hypothesis that GH overexpression accelerates atherosclerotic lesion formation. apoE(-/-) mice were crossed with bovine GH (bGH) transgenic mice to yield apoE(-/-) mice overexpressing bGH (apoE(-/-)/bGH). The mice were fed either standard or Western diet. At 22 weeks, atherosclerotic lesion area of thoracic aorta was larger in apoE(-/-)/bGH mice compared with littermate apoE(-/-) mice fed either diet (standard: +161+/-50%, Western: +430+/-134%). Aortic sinus lesions were more severe in apoE(-/-)/bGH mice fed standard diet compared with littermate apoE(-/-) mice. apoE(-/-)/bGH mice had lower (VLDL+LDL)/HDL ratios compared with littermate apoE(-/-) mice, while systolic blood pressure was higher in apoE(-/-)/bGH mice, irrespective of diet. The levels of serum amyloid A and hepatic CRP mRNA were higher in apoE(-/-)/bGH mice than in littermate apoE(-/-) mice. In conclusion, this study shows that excess GH augments the development of atherosclerosis in apoE(-/-) mice. The mechanisms could be direct effects of GH on cellular processes in the vessel wall or the result of concomitant processes such as hypertension or a general inflammatory state.

Asunto(s)

Aorta/patología , Apolipoproteínas E/deficiencia , Aterosclerosis/patología , Dieta , Modelos Animales de Enfermedad , Hormona del Crecimiento/metabolismo , Animales , Apolipoproteínas E/genética , Aterosclerosis/metabolismo , Presión Sanguínea , Proteína C-Reactiva/genética , Proteína C-Reactiva/metabolismo , Cruzamientos Genéticos , Cartilla de ADN , Hormona del Crecimiento/genética , Ratones , Ratones Noqueados , Proteína Amiloide A Sérica/metabolismo

RESUMEN

BACKGROUND AIMS: Marked changes in metabolism, including liver steatosis and hypoglycemia, occur after partial hepatectomy. Peroxisome proliferator-activated receptor alpha (PPAR alpha) is a nuclear hormone receptor that is activated by fatty acids and involved in hepatic fatty acid metabolism and regeneration. Liver fatty acid binding protein (LFABP) is an abundant protein in liver cytosol whose expression is regulated by PPAR alpha. It is involved in fatty acid uptake and diffusion and in PPAR alpha signaling. The aim of this study was to investigate the expression of PPAR alpha and LFABP during liver regeneration. METHODS: Male Sprague-Dawley rats and male C57 Bl/6 mice were subjected to 2/3 hepatectomy and LFABP and PPAR alpha mRNA and protein levels were measured at different time points after surgery. The effect of partial hepatectomy was followed during 48 h in rats and 72 h in mice. RESULTS: PPAR alpha mRNA and protein levels were decreased 26 h after hepatectomy of rats. The LFABP mRNA and protein levels paralleled those of PPAR alpha and were also decreased 26 h after hepatectomy. In mice, the mRNA level was decreased after 36 and 72 h after hepatectomy. In this case, LFABP mRNA levels decreased more slowly after partial hepatectomy than in rats. CONCLUSIONS: A marked decrease in PPAR alpha expression may be important for changed gene expression, e.g. LFABP, and metabolic changes, such as hypoglycemia, during liver regeneration.

Asunto(s)

Proteínas Portadoras/metabolismo , Hepatectomía , Hígado/metabolismo , PPAR alfa/metabolismo , Actinas/genética , Actinas/metabolismo , Animales , Glucemia/análisis , Proteínas Portadoras/genética , Proteínas de Unión a Ácidos Grasos , Expresión Génica , Glucógeno/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , PPAR alfa/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Especificidad de la Especie , Triglicéridos/metabolismo

RESUMEN

Microsomal triglyceride transfer protein (MTP) is rate-limiting in the assembly and secretion of lipoproteins containing apolipoprotein (apo) B. Previously we demonstrated that Wy 14,643 (Wy), a peroxisome proliferator-activated receptor (PPAR) alpha agonist, increases apoB-100 secretion despite decreased triglyceride synthesis. In this study, we sought to determine whether PPARalpha activation increases MTP expression and activity. Treatment with Wy increased hepatic MTP expression and activity in rats and mice and increased MTP expression in primary cultures of rat and mouse hepatocytes. Addition of actinomycin D blocked this increase and the MTP promoter (-136 to +67) containing a conserved DR1 element was activated by Wy, showing that PPARalpha activates transcription of the gene. Wy did not affect MTP expression in the intestine or in cultured hepatocytes from PPARalpha-null mice. A retinoid X receptor agonist (9-cis-retinoic acid), but not a PPARgamma agonist (rosiglitazone), increased MTP mRNA expression in cultured hepatocytes from both wild type and PPARalpha-null mice. In rat hepatocytes incubated with Wy, MTP mRNA levels increased between 6 and 24 h, and MTP protein expression and apoB-100 secretion increased between 24 and 72 h. In conclusion, PPARalpha activation stimulates hepatic MTP expression via increased transcription of the Mtp gene. This effect is paralleled by a change in apoB-100 secretion, indicating that the effect of Wy on apoB-100 secretion is mediated by increased expression of MTP.

Asunto(s)

Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Regulación de la Expresión Génica , Hígado/metabolismo , PPAR alfa/metabolismo , Alitretinoína , Animales , Apolipoproteínas B/metabolismo , Línea Celular , Células Cultivadas , Dactinomicina/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Hígado/citología , Hígado/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Regiones Promotoras Genéticas/genética , Pirimidinas/farmacología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Rosiglitazona , Tiazolidinedionas/farmacología , Transcripción Genética/efectos de los fármacos , Tretinoina/farmacología

RESUMEN

It is known that bovine GH (bGH) transgenic mice have increased body mass, insulin resistance, and altered lipoprotein metabolism when fed a normal diet (ND). In this study, the effects of 8 wk of high-fat diet (HFD) were investigated in 6-month-old male bGH mice. Although littermate controls had unchanged energy intake, energy intake was higher in the bGH mice on a HFD than on a low-fat diet. Nevertheless, the bGH mice were resistant to diet-induced weight gain, and only in the bGH mice did the HFD result in increased energy expenditure. Glucose oxidation was higher in the bGH mice compared with littermate controls on both a HFD and ND. In addition, the bGH mice had 0.5 C higher body temperature throughout the day and increased hepatic uncoupling protein 2 expression; changes that were unaffected by the HFD. On a HFD, the effect of bGH overexpression on serum triglycerides and apolipoprotein B was opposite to that on a ND, resulting in higher serum concentrations of triglycerides and apolipoprotein B compared with littermate controls. Increased serum triglycerides were explained by decreased triglyceride clearance. The HFD led to diabetes only in the bGH mice. In conclusion, bGH transgenic mice were resistant to diet-induced obesity despite hyperphagia, possibly due to increased energy expenditure. On a HFD, bGH mice became dyslipidemic and diabetic and thereby more accurately reflect the metabolic situation in acromegalic patients.

Asunto(s)

Diabetes Mellitus Experimental/fisiopatología , Hormona del Crecimiento/genética , Hiperlipidemias/fisiopatología , Hiperfagia/fisiopatología , Obesidad/fisiopatología , Acromegalia/metabolismo , Acromegalia/fisiopatología , Animales , Composición Corporal , Temperatura Corporal , Proteínas Portadoras/genética , Bovinos , Diabetes Mellitus Experimental/metabolismo , Grasas de la Dieta/farmacología , Ingestión de Alimentos , Metabolismo Energético/fisiología , Prueba de Tolerancia a la Glucosa , Hiperlipidemias/metabolismo , Hiperfagia/metabolismo , Canales Iónicos , Lípidos/sangre , Lipoproteínas/sangre , Proteínas de la Membrana/genética , Proteínas de Transporte de Membrana/genética , Ratones , Ratones Transgénicos , Proteínas Mitocondriales/genética , Obesidad/metabolismo , Consumo de Oxígeno/fisiología , Proteína Desacopladora 1 , Proteína Desacopladora 2

RESUMEN

Peroxisome proliferator-activated receptor (PPAR) alpha is a nuclear receptor that is mainly expressed in tissues with a high degree of fatty acid oxidation such as liver, heart, and skeletal muscle. Unsaturated fatty acids, their derivatives, and fibrates activate PPARalpha. Male rats are more responsive to fibrates than female rats. We therefore wanted to investigate if there is a sex difference in PPARalpha expression. Male rats had higher levels of hepatic PPARalpha mRNA and protein than female rats. Fasting increased hepatic PPARalpha mRNA levels to a similar degree in both sexes. Gonadectomy of male rats decreased PPARalpha mRNA expression to similar levels as in intact and gonadectomized female rats. Hypophysectomy increased hepatic PPARalpha mRNA and protein levels. The increase in PPARalpha mRNA after hypophysectomy was more pronounced in females than in males. GH treatment decreased PPARalpha mRNA and protein levels, but the sex-differentiated secretory pattern of GH does not determine the sex-differentiated expression of PPARalpha. The expression of PPARalpha mRNA in heart or soleus muscle was not influenced by gender, gonadectomy, hypophysectomy, or GH treatment. In summary, pituitary-dependent hormones specifically regulate hepatic PPARalpha expression. Sex hormones regulate the sex difference in hepatic PPARalpha levels, but not via the sexually dimorphic GH secretory pattern.

Asunto(s)

Hormonas Esteroides Gonadales/fisiología , Hormonas Hipofisarias/fisiología , Receptores Citoplasmáticos y Nucleares/genética , Caracteres Sexuales , Factores de Transcripción/genética , Animales , Estradiol/farmacología , Ayuno , Femenino , Expresión Génica/efectos de los fármacos , Hormona del Crecimiento/farmacología , Hipofisectomía , Hígado/química , Masculino , Músculo Esquelético/química , Miocardio/química , Orquiectomía , Ovariectomía , ARN Mensajero/análisis , Ratas , Ratas Sprague-Dawley , Receptores Citoplasmáticos y Nucleares/análisis , Testosterona/farmacología , Factores de Transcripción/análisis

RESUMEN

Alzheimer's disease (AD) is a progressive neurodegenerative disorder, of which the pathogenesis is thought to involve increased beta-amyloid (Abeta) deposition and abnormal immunological responses. To elucidate the mechanisms involved in Abeta-mediated inflammation, we used immunocytochemistry and in situ hybridization to study the potential role of the cytokines interferon-gamma (IFN-gamma), interleukin (IL)-12 and IL-4 in transgenic mice APP(SWE) (Tg2576) that overexpress the human beta-amyloid precursor protein gene. Cytokine and cytokine mRNA expression was detected in brain sections from cortical regions at various postnatal ages ranging from 3 to 19 months. High levels of IFN-gamma and IL-12 mRNA expression, as well as their protein production, appeared early at 9 months and peaked at 17-19 months in Tg2576 mice. Significantly increased transcripts of IFN-gamma and IL-12 genes were found in the reactive microglia and astrocytes surrounding beta-amyloid deposits. In accordance with the kinetics of mRNA levels, the expression of IFN-gamma and IL-12 at the protein level was positively correlated with age and reached a maximum in 17-19-month-old mice. Both findings suggest a role for the pro-inflammatory cytokines IFN-gamma and IL-12 in early disease development and are consistent with microglial activation related to beta-amyloid formation. In contrast, transcription and production of IL-4 in brain sections was almost undetectable in transgenic mice up to post-natal ages of 17-19 months. These results suggest a major pro-inflammatory role for IL-12 and IFN-gamma in Tg2576 transgenic mice that may provide the association between beta-amyloid plaque formation and microglial and astrocyte activation in these animals. These observations call for further studies on the potential role of anti-inflammatory therapeutic strategies for AD.

Asunto(s)

Precursor de Proteína beta-Amiloide/genética , Corteza Cerebral/inmunología , Interferón gamma/genética , Interleucina-12/genética , Interleucina-4/genética , Factores de Edad , Animales , Corteza Cerebral/metabolismo , Regulación hacia Abajo/inmunología , Femenino , Expresión Génica/inmunología , Interferón gamma/inmunología , Interferón gamma/metabolismo , Interleucina-12/inmunología , Interleucina-12/metabolismo , Interleucina-4/inmunología , Interleucina-4/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , ARN Mensajero/análisis , Regulación hacia Arriba/inmunología

RESUMEN

Natural killer (NK) cells are implicated in T cell-mediated autoimmune diseases. Experimental autoimmune neuritis (EAN) is a CD4+ T cell-mediated animal model of the Guillain-Barré syndrome in human. The role of NK cells in the initiation and development of EAN remains unclear. In the present study, we demonstrate that anti-NKR-P1A monoclonal antibody (mAb) treatment in vivo did not affect the initiation and development of clinical EAN in Lewis rats induced by immunization with peripheral nerve myelin P0 protein peptide 180-199 and Freund's complete adjuvant, as well as the proportion of NKR-P1A+ cells (including NK cells and NKT cells) in the spleen. Furthermore, inflammatory cell infiltrations and demyelination in the peripheral nervous system (PNS) and in vitro P0 peptide 180-199-specific splenocyte proliferation were not different in anti-NKR-P1A mAb-treated rats compared to the control antibody-treated rats. The cytotoxic activity of NKR-P1A+ cells, determined by NK cell-sensitive K562 cells as target cells, decreased markedly in anti-NKR-P1A mAb-treated rats, suggesting that decrease of the cytotoxic activities of NKR-P1A+ cells is not sufficient to alter clinical EAN, although NKR-P1A+ cells may participate in the pathogenesis of T cell-mediated autoimmune diseases, such as EAN, by the mechanisms that involve the release of cytokines.

Asunto(s)

Antígenos de Superficie/inmunología , Células Asesinas Naturales/inmunología , Lectinas Tipo C , Neuritis Autoinmune Experimental/inmunología , Neuritis Autoinmune Experimental/fisiopatología , Animales , Anticuerpos Monoclonales/farmacología , Citotoxicidad Inmunológica/inmunología , Enfermedades Desmielinizantes/inmunología , Citometría de Flujo , Síndrome de Guillain-Barré/inmunología , Síndrome de Guillain-Barré/fisiopatología , Masculino , Proteína P0 de la Mielina/farmacología , Subfamilia B de Receptores Similares a Lectina de Células NK , Fragmentos de Péptidos/farmacología , Nervios Periféricos/inmunología , Nervios Periféricos/fisiopatología , Ratas , Ratas Endogámicas Lew , Bazo/citología , Bazo/inmunología