Molecular and Functional Characterization of Choline Transporter-Like Proteins in Esophageal Cancer Cells and Potential Therapeutic Targets

In this study, we examined the molecular and functional characterization of choline uptake in the human esophageal cancer cells. In addition, we examined the influence of various drugs on the transport of [3H]choline, and explored the possible correlation between the inhibition of choline uptake and apoptotic cell death. We found that both choline transporter-like protein 1 (CTL1) and CTL2 mRNAs and proteins were highly expressed in esophageal cancer cell lines (KYSE series). CTL1 and CTL2 were located in the plasma membrane and mitochondria, respectively. Choline uptake was saturable and mediated by a single transport system, which is both Na+-independent and pH-dependent. Choline uptake and cell viability were inhibited by various cationic drugs. Furthermore, a correlation analysis of the potencies of 47 drugs for the inhibition of choline uptake and cell viability showed a strong correlation. Choline uptake inhibitors and choline deficiency each inhibited cell viability and increased caspase-3/7 activity. We conclude that extracellular choline is mainly transported via a CTL1. The functional inhibition of CTL1 by cationic drugs could promote apoptotic cell death. Furthermore, CTL2 may be involved in choline uptake in mitochondria, which is the rate-limiting step in S-adenosylmethionine (SAM) synthesis and DNA methylation. Identification of this CTL1- and CTL2-mediated choline transport system provides a potential new target for esophageal cancer therapy.

Effect of Trifolium pratense extract on methionine-choline-deficient diet-induced steatohepatitis in C57BL/6 mice / 中国天然药物

AIM@#The potential of Trifolium pratense (red clover) extract in the prevention of lipid disorder has attracted increasing attention in recent years. In this study, the aim was to determine whether and how red clover extract affected the development of murine diet-induced non-alcoholic steatohepatitis.@*METHODS@#Non-alcoholic steatohepatitis was induced in C57BL/6 mice by feeding mice with a methionine-choline-deficient (MCD) diet. Hematoxylin and eosin staining was used for histological analyses. Real-time PCR was used to analyze the mRNA expression levels.@*RESULTS@#Hepatic steatosis and necroinflammation was observed in MCD diet-fed mice, and this diet-induced steatosis was significantly attenuated, whereas liver inflammation was not significantly attenuated, by red clover extract treatment. Consistent with the results of H&E staining, the MCD diet-induced increase of liver triglycerides and cholesterol levels were significantly reduced by red clover extract treatment. However, with the improvement in hepatic steatosis, mRNA levels of acetyl CoA oxidase, carnitine palmitoyl transferase-1, and liver fatty acid-binding protein, three genes regulated by peroxisome proliferator-activated receptor (PPAR) α, were unaffected.@*CONCLUSION@#Red clover extract alleviated MCD diet-induced hepatic steatosis, but did not ameliorate liver inflammation in C57BL/6 mice, and the improvement in hepatic steatosis was not through activating PPARα.

Mechanism of hepatocyte apoptosis in rats with liver fibrosis induced by lipogenic methionine-choline-deficient diet / 中华病理学杂志

<p><b>OBJECTIVE</b>To clarify the effects of endoplasmic reticulum stress (ER stress) and mitogen-activated protein kinase (MAPK) on hepatocyte apoptosis in rats with non-alcoholic fatty liver fibrosis induced by methionine-choline-deficient diet (MCDD).</p><p><b>METHODS</b>Nonalcoholic steatohepatitis with advanced fibrosis was induced in rats by giving a MCDD for 10 weeks (group M). A methionine-choline-control diet (MCCD) instead of MCDD was given for the last 2 weeks to the experimental group (group R). Steatosis, fibrosis and inflammation were determined by tissue staining. The activation of hepatic stellate cells and oxidative stress were determined by immunostaining, immunoblotting or real time-PCR (RT-PCR), respectively. Hepatocyte apoptosis was determined by TUNEL staining. Expressions of glucose-regulated protein 78 (GRP78), caspase-12, caspase-7, cleaved caspase-7, caspase-3, cleaved caspase-3, and caspase-9 were evaluated to clarify the presence of ER stress. Expressions of c-Jun, ERK1/2, p-ERK1/2 were evaluated to clarify the states of MAPK signaling.</p><p><b>RESULTS</b>Changing the diet from MCDD to MCCD triggered the reduction of fat in hepatocytes, a decrease in inflammatory response, oxidative stress, and fibrosis. The protein expressions of ERP78, caspase-12, caspase-7, and cleaved caspase-7 were increased significantly in group M compared with normal control group (group N, P < 0.05 or P < 0.01), the mRNA expressions of ERP78, caspase-12, and caspase-7 were also increased significantly in group M compared with group N (3.03 ± 0.41 vs 2.12 ± 0.37, 1.86 ± 0.36 vs 0.78 ± 0.20, and 2.38 ± 0.19 vs 1.84 ± 0.13, respectively, P < 0.05 or P < 0.01), while they recovered immediately in group R. In contrast, the protein levels of caspase-3, cleaved caspase-3 and mRNA expressions of caspase-3 and caspase-9 revealed no significant differences in three groups (P > 0.05). The mRNA expressions of c-Jun and protein levels of ERK1 and p-ERK1 were increased significantly in group M compared with group N (P < 0.01), while they recovered immediately after changing the diet from MCDD to MCCD.</p><p><b>CONCLUSIONS</b>ER stress plays a role in the development and regression of non-alcoholic fatty liver fibrosis induced by MCDD, however, ER stress-related caspase-12 pathway may not be the main mechanism of hepatic apoptosis, and MAPK signaling may play an important role in hepatic apoptosis in the model.</p>

Alteración de la función secretora biliar en esteatosis hepática experimental / Altered bile secretory function in experimental non-alcoholic fatty liver disease

Non-alcoholic fatty liver (NAFLD) is a clinical entity whose importance has been increasing, because of its potential progression to chronic liver disease. The alteration of bile secretory function may be a relevant factor of hepatic injury in NAFLD. Objectives: To assess basal bile secretory function and protein mass of three major hepatobiliary transporters in an experimental NAFLD model. Materials and Methods: The bile secretory function was determined by conventional techniques in Sprague-Dawley control rats fed with a choline-deficient diet (CDD) for 8 weeks. Protein mass of Ntcp, Bsep and Mrp2 was measured by western blot. Results: An impaired bile secretory function was observed in rats fed with DDC (reduction of bile flow and secretion of bile acids and organic anions). In addition, DDC fed rats showed higher levels of serum aminotransferases. Ntcp protein mass decreased in rats with DDC, while Bsep and Mrp2 did not show quantitative variations in this experimental model. Conclusions: In this experimental model of NAFLD an impaired bile secretory function was observed, determining a cholestatic pattern. The decrease in Ntcp protein mass with unaltered Bsep and Mrp2 protein mass, associated with a significant decrease in bile secretion suggests a functional impairment of these transporters in rats fed with DDC diet.

El hígado graso no alcohólico (HGNA) es una entidad clínica de importancia creciente por su potencial progresión a daño hepático crónico. La alteración de la función secretora biliar puede ser un factor relevante en el daño o lesión hepática asociada al HGNA. Objetivos: Evaluar la función secretora biliar basal y los niveles de expresión proteica de tres de los principales transportadores hepatobiliares en un modelo de HGNA experimental. Materiales y Métodos: La función secretora biliar fue determinada por técnicas convencionales en ratas Sprague-Dawley control y alimentadas con una dieta deficiente en colina (DDC) durante 8 semanas. Los niveles de expresión proteica de Ntcp, Bsep y Mrp2 fueron cuantificados por western blot. Resultados: Se observó un deterioro de la función secretora biliar en las ratas alimentadas con DDC (reducción del flujo biliar y de secreción de ácidos biliares y aniones orgánicos). Además, las ratas con DDC presentaron niveles más altos de transaminasas séricas. Los niveles de expresión proteica de Ntcp disminuyeron en las ratas con DDC, mientras que Bsep y Mrp2 no presentaron variaciones cuantitativas en este modelo experimental. Conclusiones: En este modelo de HGNA experimental se observó una función secretora biliar alterada, determinando un patrón colestásico. La disminución de los niveles de expresión proteica de Ntcp junto con la mantención de Bsep y Mrp2, asociados a una disminución significativa de la secreción biliar, sugiere un deterioro funcional de estos transportadores en ratas alimentadas con dieta DDC.

Methionine- and choline-deficient diet induces hepatic changes characteristic of non-alcoholic steatohepatitis / Dieta deficiente em metionina e colina induz mudanças hepáticas características de esteatohepatite não-alcoólica

CONTEXT: Non-alcoholic steatohepatitis is a disease with a high incidence, difficult diagnosis, and as yet no effective treatment. So, the use of experimental models for non-alcoholic steatohepatitis induction and the study of its routes of development have been studied. OBJECTIVES: This study was designed to develop an experimental model of non-alcoholic steatohepatitis based on a methionine- and choline-deficient diet that is manufactured in Brazil so as to evaluate the liver alterations resulting from the disorder. METHODS: Thirty male C57BL6 mice divided in two groups (n = 15) were used: the experimental group fed a methionine- and choline-deficient diet manufactured by Brazilian company PragSoluções®, and the control group fed a normal diet, for a period of 2 weeks. The animals were then killed by exsanguination to sample blood for systemic biochemical analyses, and subsequently submitted to laparotomy with total hepatectomy and preparation of the material for histological analysis. The statistical analysis was done using the Student's t-test for independent samples, with significance level of 5 percent. RESULTS: The mice that received the methionine- and choline-deficient diet showed weight loss and significant increase in hepatic damage enzymes, as well as decreased systemic levels of glycemia, triglycerides, total cholesterol, HDL and VLDL. The diagnosis of non-alcoholic steatohepatitis was performed in 100 percent of the mice that were fed the methionine- and choline-deficient diet. All non-alcoholic steatohepatitis animals showed some degree of macrovesicular steatosis, ballooning, and inflammatory process. None of the animals which were fed the control diet presented histological alterations. All non-alcoholic steatohepatitis animals showed significantly increased lipoperoxidation and antioxidant enzyme GSH activity. CONCLUSION: The low cost and easily accessible methionine- and choline-deficient diet explored in this study is highly effective in inducing steatosis and steatohepatitis in animal model, alterations that are similar to those observed in human livers.

CONTEXTO: A esteatohepatite não-alcoólica é uma doença com alta incidência, difícil diagnóstico e tratamentos ainda não efetivos. Com isso, o uso de modelos experimentais para indução da esteatohepatite não-alcoólica e o estudo das rotas de desenvolvimento desta doença vem sendo empregado. OBJETIVO: Desenvolver um modelo experimental de esteatohepatite não-alcoólica a partir do uso de uma dieta deficiente de metionina e colina fabricada no Brasil e avaliar as alterações hepáticas decorrentes da doença. MÉTODO: Foram utilizados 30 camundongos machos da linhagem C57BL6, onde a metade foi alimentada com dieta deficiente em metionina e colina desenvolvida no Brasil e o restante com dieta controle no período de duas semanas. Após, os animais foram mortos por exaguinação e foi realizada laparotomia com hepatectomia total e preparo do material para análise histológica, coleta de sangue para análises bioquímicas sistêmicas. O nível de significância foi 5 por cento. RESULTADOS: Os ratos que receberam a dieta deficiente em metionina e colina apresentaram perda de peso e aumento significativo das enzimas de integridade hepática e diminuição dos níveis bioquímicos sistêmicos de glicemia, triglicerídeos, colesterol total, HDL e VLDL. Todos os animais com esteatohepatite não-alcoólica mostraram, pelo menos, algum grau de esteatose macrovesicular. O diagnóstico de esteatohepatite não-alcoólica foi realizado em 100 por cento dos camundongos que receberam a dieta deficiente em metionina e colina e nenhum dos animais que recebeu dieta controle apresentou alterações histológicas. Os animais com esteatohepatite não-alcoólica apresentaram aumento de lipoperoxidação e da enzima antioxidante GSH. CONCLUSÃO:A dieta deficiente de metionina e colina desenvolvida neste estudo apresenta índices elevados de indução de esteatose e esteatohepatite em modelo animal, apresentando comportamento patológico semelhante ao humano, com custo adequado e facilidade na sua aquisição.

Variable number tandem repeats in the promoter region of prostacyclin synthase gene in choline deficient rats

Weanling Sprague-Dawley rats were fed on a choline-deficient diet with hydrogenated vegetable oil and corn oil as lipids develop acute renal failure. Pathogenesis of the latter is controversial and an ischemic mechanism has been proposed. Arachidonic acid derivatives are involved in the regulation of vascular tonus. Vasospasm could be due to an increase in tromboxane A2-mediated vasoconstriction or to a decrease in prostacyclin-induced vasodilatation. Enzymes involved in the synthesis of both compounds are tromboxane A2- and prostacyclin-synthase respectively. The aim of this study was to identify the variable number tandem repeats (VNTR) in the promoter region of prostacyclin synthase gene and verify if there exists a relationship between the occurrence of VNTR in those choline-deficient rats which die because of acute renal failure and those which do not. We verified the presence of the VNTR in the prostacyclin synthase rat gene, but we did not find any difference in the molecular weight of the alleles between experimental and control rats. Renal reparation of the acute kidney injury due to choline deficiency in some rats is not related with differences in VNTR in the promoter region of the prostacyclin synthase gene.

The vitamin E reduces liver lipoperoxidation and fibrosis in a model of nonalcoholic steatohepatitis / A vitamina E reduz a lipoperoxidação hepática e a fibrose em modelo experimental de esteatohepatite não-alcoólica

CONTEXT: No effective treatment is available for nonalcoholic steatohepatitis in nowadays. OBJECTIVES: To develop a model of nonalcoholic steatohepatitis induced by a methionine and choline deficient diet, as well as to evaluate the role of metformin, vitamin E and simvastatin in the nonalcoholic steatohepatitis progression. METHODS: The study analyzed prospectively 50 Wistar rats for a 90-day period and divided them into five groups of 10 rats. One group was given standard rat diet and the others received the methionine and choline deficient diet. Among the four groups that received this diet, one received saline 0,9 percent and the others received metformin, vitamin E or simvastatin. After the study period, the animals were sacrificed and their blood was collected for biochemical analysis. The livers were removed for lipoperoxidation analysis and for the histological examinations. RESULTS: The methionine and choline deficient diet was able to induce steatosis in 100 percent of the animals and nonalcoholic steatohepatitis in 27 (69.2 percent). The alanine aminotransferase levels were significantly higher in the simvastatin group. The aspartate aminotransferase levels were also higher in the simvastatin group, but were statistically significant only in relation to the standard diet group. When lipoperoxidation values were compared, the groups that received standard rat diet and methionine and choline deficient with vitamin E presented significantly lower rates than the others. The presence of fibrosis was significantly smaller in the group receiving vitamin E. CONCLUSIONS: The diet used was able to induce steatosis and nonalcoholic steatohepatitis. Besides vitamin E showed to reduce the liver oxidative stress, as well as the fibrosis development

CONTEXTO: Ainda não há um tratamento comprovadamente eficaz para a esteatohepatite não-alcoólica. OBJETIVO: Desenvolver um modelo experimental de esteatohepatite não-alcoólica induzida por dieta deficiente em metionina e colina, bem como avaliar o papel do metformina, da vitamina E e da sinvastatina na evolução da esteatohepatite não-alcoólica. MÉTODOS: Foram estudados prospectivamente 50 ratos da linhagem Wistar, por um período de 90 dias, sendo os mesmos divididos em cinco grupos de 10 ratos. Um grupo recebeu ração convencional e os demais a dieta deficiente em metionina e colina. Dentre os quatro grupos que receberam a dieta, para um foi administrado soro fisiológico e para os demais o metformina, a vitamina E e a sinvastatina. Após o período de estudo os animais foram mortos, sendo colhido sangue para análise bioquímica e removido o fígado para análise da lipoperoxidação através do teste de substâncias reativas ao ácido tiobarbitúrico e para a realização dos exames histológicos. RESULTADOS: A dieta deficiente em metionina e colina foi capaz de induzir esteatose em 100 por cento dos animais enquanto que esteatohepatite não-alcoólica foi diagnosticada em 27 (69,2 por cento). Os níveis da ALT foram significativamente maiores no grupo da sinvastatina. Os níveis de AST também foram maiores no grupo da sinvastatina, mas apenas foram estatisticamente significantes em relação ao grupo da ração. Quando se compararam os valores de lipoperoxidação, os grupos da ração convencional e da vitamina E apresentaram índices significativamente menores que os demais. A presença de fibrose foi significativamente menor no grupo que recebeu a vitamina E. CONCLUSÕES: A dieta utilizada foi capaz de induzir esteatose e esteatohepatite não-alcoólica, sendo que a vitamina E demonstrou reduzir o estresse oxidativo hepático, bem como o desenvolvimento de fibrose

Involvement of endoplasmic reticulum stress in development of fatty liver fibrosis induced by methionine-choline-deficient diet in rats / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To study role of endoplasmic reticulum stress in the development of fatty liver fibrosis induced by methionine-choline-deficient diet in rats.</p><p><b>METHODS</b>Non-alcoholic steatohepatitis was induced by 10 weeks- methionine-choline-deficient diet (MCDD), Markers of endoplasmic reticulum stress were determined by immunoblotting and real-time PCR.</p><p><b>RESULTS</b>The number of apoptotic hepatocytes, The expression levels of endoplasmic reticulum stress markers were increased significantly in MCDD group compared to control group (probability value less than 0.05 or probability value less than 0.01), while ratio of hepatocyte proliferation/apoptosis was decreased in MCDD group (probability value less than 0.01). The number of hepatocytes apoptosis, and the expression levels of endoplasmic reticulum stress markers were decreased significantly 2 weeks after the feeding with normal diet in MCDD group (probability value less than 0.05 or probability value less than 0.01).</p><p><b>CONCLUSION</b>MCDD induces endoplasmic reticulum stress and fibrosis in rats.</p>

Modelo experimental de esteatohepatite não-alcoólica com dieta deficiente em metionina e colina / Model of experimental nonalcoholic steatohepatitis from use of methionine and choline deficient diet

CONTEXTO: Ainda existem vários aspectos desconhecidos a respeito da esteatohepatite não-alcoólica, principalmente em relação à fisiopatologia e ao seu tratamento medicamentoso. Dessa forma, os modelos experimentais são importante para o melhor entendimento dessa doença, bem como para a avaliação do efeito das drogas. OBJETIVO: Desenvolver um modelo experimental de esteatohepatite não-alcoólica a partir do uso de dieta deficiente em metionina e colina. MÉTODOS: Foram utilizados 50 ratos machos da linhagem Wistar. A dieta deficiente em metionina e colina foi processada de forma artesanal. Um grupo de 40 animais recebeu a dieta durante 90 dias e utilizou-se um grupo controle com 10 ratos que recebeu ração padronizada pelo mesmo período. Após, os animais foram mortos por decapitação e foi realizada laparotomia com hepatectomia total e preparo do material para análise macroscópica e histológica. O nível de significância foi a = 0,05. RESULTADOS: Os ratos que receberam a dieta apresentaram perda significativa de peso, com achados de desnutrição e todos mostraram, pelo menos, algum grau de esteatose macrovesicular. O diagnóstico de esteatohepatite não-alcoólica foi realizado em 27 (70 por cento) dos 39 ratos que receberam a dieta. Nenhum dos 10 ratos que recebeu ração apresentou alterações histológicas. CONCLUSÃO:A dieta com restrição de metionina e colina desenvolvida apresenta índices elevados de indução de esteatose e esteatohepatite em modelo animal com baixo custo.

CONTEXT: There are still many unknown aspects about nonalcoholic steatohepatitis, especially regarding its pathophysiology and pharmacological treatment. Thus, experimental models are important for a better understanding of this disease and the evaluation of the effects of drugs. OBJECTIVE: To develop a model of experimental nonalcoholic steatohepatitis from use of methionine and choline deficient diet. METHODS: Fifty Wistar male rats were studied. A methionine and choline deficient diet has been processed in a craft. A group of 40 animals received the deficient diet for 90 days, and a group of 10 rats (control group) received the standardized ration in the same period. After, the animals were killed by decapitation, and laparotomy was performed. Hepatectomy was performed and the liver was studied by macroscopy and microscopy. The level of significance considered was of 0,05. RESULTS: The rats that received the deficient diet showed significant loss of weight with findings from malnutrition and all of them had at least some degree of macrovesicular steatosis. The diagnosis of nonalcoholic steatohepatitis was performed in 27 (70 percent) of the 39 rats that received this deficient diet (1 rat died during the study). None of the 10 rats that received the standardized diet had histological abnormalities. CONCLUSION: The diet restricted in methionine and choline induced steatosis and steatohepatitis in an animal model with low cost.

Genomic DNA Methylation Status and Plasma Homocysteine in Choline- and Folate-Deficient Rats

Elevated plasma homocysteine ( Hcy) is a risk factor for cognitive dysfunction and Alzheimer disease, although the mechanism is still unknown. Both folate and betaine, a choline metabolite, play essential roles in the remethylation of Hcy to methionine. Choline deficiency may be associated with low folate status and high plasma Hcy. Alterations in DNA methylation also have established critical roles for methylation in development of the nervous system. This study was un-dertaken to assess the effect of choline and folate deficiency on Hcy metabolism and genomic DNA methylation status of the liver and brain. Groups of adult male Sprague Dawley rats were fed on a control, choline-deficient ( CD) , folate-deficient ( FD) or choline/folate-deficient ( CFD) diets for 8 weeks. FD resulted in a significantly lower hepatic folate ( 23%)(p < 0.001) and brain folate ( 69%)(p < 0.05) compared to the control group. However, plasma and brain folate remained unaltered by CD and hepatic folate reduced to 85% of the control by CD ( p < 0.05) . Plasma Hcy was signi-ficantly increased by FD ( 18.34 +/- 1.62 micrometer) and CFD ( 19.35 +/-3.62 micrometer) compared to the control ( 6.29 +/-0.60 micrometer) ( p < 0.001) , but remained unaltered by CD. FD depressed S-adenosylmethionine ( SAM) by 59% ( p < 0.001) and ele-vated S-adenosylhomocysteine ( SAH) by 47% in liver compared to the control group ( p < 0.001) . In contrast, brain SAM levels remained unaltered in CD, FD and CFD rats. Genomic DNA methylation status was reduced by FD in liver ( p< 0.05) . Genomic DNA hypomethylation was also observed in brain by CD, FD and CFD although it was not signifi-cantly different from the control group. Genomic DNA methylation status was correlated with folate stores in liver ( r = - 0.397, p < 0.05) and brain ( r = - 0.390, p < 0.05) , respectively. In conclusion, our data demonstrated that genomic DNA methylation and SAM level were reduced by folate deficiency in liver, but not in brain, and correlated with folate concentration in the tissue. The fact that folate deficiency had differential effects on SAM, SAH and genomic DNA methylation in liver and brain suggests that the Hcy metabolism and DNA methylation are regulated in tissue-specific ways.

Choline: are our university students eating enough? / La Colina: ¿la Ingieren nuestros estudiantes universitarios en cantidades suficientes?

Choline is an essential nutrient; dietary deficiency of choline is associated with impaired liver function, elevated blood concentrations of alanine aminotransferase, creatinine phosphokinase and homocysteine. There is also depletion of acetylcholine concentration in the brain, leading to deficit in memory function. The authors examined the dietary intake of choline in groups of students at the Mona Campus of the University of the West Indies. Sixty-two medical students (first and second years) and biochemistry students (final year) were recruited They were asked to (including amounts) record all foods and drinks consumed for three days (two weekdays and one weekend day). The sheets were collected and the amount of choline and betaine (a metabolite of choline) consumed were calculated Dietary intake of folate was also evaluated. The analysis revealed that 86.2of the females and 90.9of the males reported diets that delivered less daily choline than the adequate intake quoted by the Institute of Medicine of the National Academy of Sciences, USA (425-550 mg/day). The betaine consumption ranged between 25 to 620 mg/day (no adequate intake documented) and the folate consumed was more than the recommended daily allowance of folate (180-200 microg/day). The dietary intake of choline in the majority of students is below adequate intake. Although folate also serves similar functions to choline, it is unlikely that it can substitute for choline in all physiological aspects and therefore the implications of low dietary choline need further investigation.

La colina es un nutriente esencial. La deficiencia dietética de colina está asociada con el deterioro de la función hepática, así como con elevadas concentraciones en sangre de alanina-aminotrans-ferasa, creatinina-fosfoquinasa y homocisteína. Asimismo, se produce un agotamiento de la concentración de acetilcolina en el cerebro, lo cual conduce a un déficit en la función de la memoria. Los autores examinaron la ingestión dietética de colina en grupos de estudiantes del campus de Mona de la Universidad de West Indies. Se reclutaron sesenta y dos estudiantes de ciencias médicas (de primer y segundo año) y bioquímica (FAltimo año). Se les pidió que tomaran notas (incluyendo cantidades) de todos los alimentos y bebidas consumidos en tres días (dos días de entre semana y un día de fin de semana). Se recogieron las anotaciones y se calculó el consumo de colina y betaína (un metabolito de la colina). Se evaluó la ingestión de folato. El análisis reveló que el 86.2% de las mujeres y el 90.9% de los hombres, reportaron dietas cuyo suministro de colina por día se hallaba por debajo del consumo adecuado indicado por el Instituto de Medicina de la Academia Nacional de Ciencias de Estados Unidos (425–550 mg/día). El consumo de betaína osciló de 25 a 620 mg/día (no existe documentación sobre el consumo adecuado), en tanto que el folato consumido estuvo por encima de la ingestión diaria de folato recomendada (180 – 200 ug/día). El consumo dietético de colina de la mayoría de los estudiantes está por debajo del consumo adecuado.

Liver mitochondrial dysfunction and oxidative stress in the pathogenesis of experimental nonalcoholic fatty liver disease

Oxidative stress and hepatic mitochondria play a role in the pathogenesis of nonalcoholic fatty liver disease. The aim of the present study was to evaluate the role of hepatic mitochondrial dysfunction and oxidative stress in the pathogenesis of the disease. Fatty liver was induced in Wistar rats with a choline-deficient diet (CD; N = 7) or a high-fat diet enriched with PUFAs-omega-3 (H; N = 7) for 4 weeks. The control group (N = 7) was fed a standard diet. Liver mitochondrial oxidation and phosphorylation were measured polarographically and oxidative stress was estimated on the basis of malondialdehyde and glutathione concentrations. Moderate macrovacuolar liver steatosis was observed in the CD group and mild liver steatosis was observed in the periportal area in the H group. There was an increase in the oxygen consumption rate by liver mitochondria in respiratory state 4 (S4) and a decrease in respiratory control rate (RCR) in the CD group (S4: 32.70 ± 3.35; RCR: 2.55 ± 0.15 ng atoms of O2 min-1 mg protein-1) when compared to the H and control groups (S4: 23.09 ± 1.53, 17.04 ± 2.03, RCR: 3.15 ± 0.15, 3.68 ± 0.15 ng atoms of O2 min-1 mg protein-1, respectively), P < 0.05. Hepatic lipoperoxide concentrations were significantly increased and the concentration of reduced glutathione was significantly reduced in the CD group. A choline-deficient diet causes moderate steatosis with disruption of liver mitochondrial function and increased oxidative stress. These data suggest that lipid peroxidation products can impair the flow of electrons along the respiratory chain, causing overreduction of respiratory chain components and enhanced mitochondrial reactive oxygen species. These findings are important in the pathogenesis of nonalcoholic fatty liver disease.

Ocular lesions and experimental choline deficiency

Previous studies have shown ocular haemorrhages in choline-deficient rats. The aim of this paper is to study further the relationship between ocular and renal lesions and biochemical alterations in rats fed a choline-deficient diet. Fifty one weanling male Wistar rats, were divided into two groups. Thirty one ofthem were fed a choline-deficient diet and the rest was fed a choline- supplemented diet ad libitum. Animalsfrom both groups were killed between the fifth and the eighth day. Urea, creatinine and homocysteine concentrations in blood were determined. Eyes were used for light microscopy study; high resolution lightmicroscopy and the study of the retina as “rétine a plat”. Kidneys were studied by light microscopy. Cholinesupplementedrats did not show ocular or renal lesion. Choline-deficient rats that showed renal lesions, tubular or cortical necrosis, did not always have ocular changes. There were no ocular changes in the only cholinedeficient rat without renal lesion. The ocular changes consisted mainly in haemorrhage in both cameras andciliary and vitreous bodies. Correlations between ocular and renal lesion (r=0.72, p<0.0001, CI 95%: 0.48-0.86); ocular lesion and creatinine (r=0.86, p<0.0001, CI 95%: 0.72-0.93) and ocular lesion and urea (r=0.70, p<0.0001, CI 95%: 0.44-0.85) were positive. Choline-deficiency induces ocular haemorrhagic lesions after the development of renal necrosis. The ocular pathology could be due to the immaturity of the ocular vasculature at this age. The hyaloid, choroid and retinal system are involved

Estudios previos han demostradohemorragia ocular en ratas deficientes en colina. El objetivo de este trabajo es profundizar en la relación entre las alteraciones oculares, renales y bioquímicas en ratas deficientes en colina. Cincuenta y una ratas Wistar macho recién destetadas fueron divididas en dos grupos: treinta y una fueron alimentadas con una dieta colino deficiente y el resto con colina suplementada ad-libitum. Los animales de ambos grupos fueron sacrificados entre el quinto y el octavo día. Se midió la concentración de urea, creatinina y homocisteína en sangre. Los ojos fueron estudiados por microscopía de luz, microscopía óptica de alta resolución y para el estudio de la retina como retina plana. Los riñones fueron estudiados por microscopía de luz. Las ratas suplementadas con colina no mostraron lesiones oculares o renales. Las colino deficientes que mostraron lesiones renales, necrosis tubular o cortical, no siempre tuvieron cambios oculares. No se encontraron cambios oculares en la única rata deficiente en colina sin lesión renal. Los cambios oculares consistieron principalmente en hemorragia enambas cámaras, cuerpo ciliar y vítreo. La correlación entre la lesión ocular y renal (r=0.72, p<0.0001, CI 95%:0.48-0.86), lesión ocular y creatinina (r=0.86, p<0.0001, CI 95%: 0.72-0.93) y lesión ocular y urea (r=0.70,p<0.0001, CI 95%: 0.44-0.85) fue positiva. La deficiencia de colina induce lesiones oculares luego del desarrollode la necrosis renal. La patología ocular podría ser debida a la inmadurez de los vasos oculares. El sistemahialoide, coroideo y retinal están involucrados

Light & electron microscopy of proliferating oval cells during early chemical hepatocarcinogenesis.

Early hepatic changes were studied in male albino rats (70) of Sprague Dawley strain fed a choline devoid diet containing 0.05 per cent w/w AAF (2-acetylaminofluorene) for 12 days. Proliferating periductal and ductal cells appeared in the portal area on days 1 and 3 respectively in the experimental group. On day 7, these cells infiltrated within the sinusoids of adjacent lobules up to the first one or two layers of hepatocytes. Subsequently, these cells extended up to the midzonal region on day 21 and by day 24 the entire lobule was infiltrated. Formation of duct like structures by the proliferating cells was seen on day 21. Ultrastructurally both periductal and ductal cells showed only a few organelles. Periductal and ductal cells are the earliest cells to appear in the portal area in chemically induced hepatocarcinogenesis. Its undifferentiated ultrastructure, may suggest the stem cell nature of these cells.