ABSTRACT
Nonalcoholic fatty liver disease is a common chronic liver disease with the risk of progression to nonalcoholic hepatitis, liver fibrosis, and hepatocellular carcinoma. Nonalcoholic fatty liver disease has various pathogeneses, among which abnormal metabolism of branched-chain amino acids can induce oxidative stress, autophagy, and mitochondrial dysfunction in hepatocytes and is the most important mechanism in the development and progression of nonalcoholic fatty liver disease. This article reviews related research advances and analyzes the possible role of abnormal metabolism of branched-chain amino acids in the development and progression of nonalcoholic fatty liver disease, in order to improve clinical awareness and diagnosis.
ABSTRACT
ABSTRACT Background: Huntington's disease (HD), caused by an expanded CAG repeat at HTT, has no treatment, and biomarkers are needed for future clinical trials. Objective: The objective of this study was to verify if free carnitine and branched chain amino acids levels behave as potential biomarkers in HD. Methods: Symptomatic and asymptomatic HD carriers and controls were recruited. Age, sex, body mass index (BMI), age of onset, disease duration, UHDRS scores, and expanded CAG tract were obtained; valine, leucine, isoleucine, and free carnitine were measured. Baseline and longitudinal analysis were performed. Results: Seventy-four symptomatic carriers, 20 asymptomatic carriers, and 22 non-carriers were included. At baseline, valine levels were reduced in symptomatic and asymptomatic HD carriers when compared to non-carriers. No difference in free carnitine or isoleucine+leucine levels were observed between groups. BMI of symptomatic individuals was lower than those of non-carriers. Valine levels correlated with BMI. Follow-up evaluation was performed in 43 symptomatic individuals. UHDRS total motor score increased 4.8 points/year on average. No significant reductions in BMI or valine were observed, whereas free carnitine and isoleucine+leucine levels increased. Conclusions: Although valine levels were lower in HD carriers and were related to BMI losses observed in pre-symptomatic individuals, none of these metabolites seem to be biomarkers for HD.
RESUMO Introdução: A doença de Huntington (DH), causada por uma repetição CAG expandida no HTT, não possui tratamento e biomarcadores são necessários para futuros ensaios clínicos. Objetivo: Nosso objetivo foi verificar se os níveis de carnitina livre e aminoácidos de cadeia ramificada se comportam como potenciais biomarcadores na DH. Métodos: Portadores sintomáticos e assintomáticos e controles foram recrutados. Idade, sexo, índice de massa corporal (IMC), idade de início, duração da doença, escores UHDRS e trato CAG expandido foram obtidos; valina, leucina, isoleucina e carnitina livre foram medidas. Foram realizadas análises basal e longitudinal. Resultados: Setenta e quatro portadores sintomáticos, 20 portadores assintomáticos e 22 não portadores foram incluídos. No início do estudo, os níveis de valina estavam reduzidos em portadores de DH sintomáticos e assintomáticos quando comparados aos não portadores. Não foram observadas diferenças nos níveis de carnitina livre ou isoleucina + leucina entre os grupos. O IMC dos indivíduos sintomáticos foi menor que o dos não portadores. Níveis de valina correlacionaram-se com o IMC. Avaliação de acompanhamento foi realizada em 43 indivíduos sintomáticos. A pontuação do escore motor total da UHDRS aumentou 4,8 pontos/ano em média. Não foram observadas reduções significativas no IMC ou na valina, enquanto os níveis de carnitina livre e isoleucina+leucina aumentaram. Conclusões: Embora os níveis de valina tenham sido menores nos portadores de DH e estivessem relacionados às perdas de IMC observadas em indivíduos pré-sintomáticos, nenhum desses metabólitos parece ser biomarcador para a DH.
Subject(s)
Humans , Huntington Disease , Biomarkers , Carnitine , Amino Acids, Branched-ChainABSTRACT
ABSTRACT Alongside a proper diet, ergogenic aids with potential direct and/or indirect physical performance enhancing effects are sought after for improved adaptation to physical training. Nutritional ergogenics include diet composition changes and/or dietary supplementation. Branched-chain amino acids valine, leucine and isoleucine are widely popular among products with ergogenic claims. Their major marketing appeal derives from allegations that branched-chain amino acids intake combined with resistance physical exercise stimulates muscle protein synthesis. Evidence supporting the efficacy of branched-chain amino acids alone for muscle hypertrophy in humans is somewhat equivocal. This brief review describes physiological and biochemical mechanisms underpinning the effects of complete protein source and branched-chain amino acid intake on skeletal muscle growth in the postabsorptive and post-exercise state. Evidence in favor of or against potential anabolic effects of isolated branched-chain amino acid intake on muscle protein synthesis in humans is also examined.
RESUMO No treinamento físico, buscam-se, além de uma dieta adequada, recursos ergogênicos que possam maximizar direta e/ou indiretamente o desempenho físico. Entre as categorias de recursos ergogênicos, o nutricional compreende a modulação da composição dietética e/ou uso de suplementação. A comercialização dos suplementos de aminoácidos de cadeia ramificada valina, leucina e isoleucina possui muita popularidade entre aqueles com alegação ergogênica. O principal marketing está na afirmação de que o consumo isolado de aminoácidos de cadeia ramificada associado ao exercício físico resistido estimula a síntese de proteína muscular. As evidências da eficácia da ingestão isolada de aminoácidos de cadeia ramificada para a hipertrofia muscular em humanos parecem equivocadas. Nesta breve revisão, apresentamos a compreensão fisiológica e bioquímica de como a ingestão de uma fonte completa de proteína e de aminoácidos de cadeia ramificada afeta o crescimento do músculo esquelético no estado pós-absortivo e pós-exercício. Mostramos também as evidências que suportam ou não a afirmação dos potenciais efeitos anabólicos na síntese de proteína muscular dos aminoácidos de cadeia ramificada quando consumidos isoladamente em humanos.
Subject(s)
Humans , Amino Acids, Branched-Chain/metabolism , Muscle Proteins/biosynthesis , Exercise/physiology , Muscle, Skeletal/metabolism , Postprandial Period/drug effects , Dietary Supplements , Gastrointestinal Absorption/drug effects , Amino Acids, Branched-Chain/physiologyABSTRACT
Objective: To observe the effect of imbalanced BCAA on metabolism of gastric cancer cell line 800-7901 in Vitro. Methods: L-Valine(L-Val) of MEM culture medium Were restricted to serial levels of 1/2, 1/4, 1/8 or 1/16 concentration of normal With increased L-Leucine(L-Leu) concentration to 1 fold, 2 folds cc 4 folds respectively. Gastric poor differentiated cancer cell line 800-7901 and fetal liver cell were cultured in these culture media. Morphologic character of two cell lines were observed everyday. Total protein mounts were recorded on the 3nd day and 5th day of incubation. Consuming volume of L-Val , L-Les and glucose of 800-7901 were detected respectively. Results :Restricted L-Val to less than 1/8 concentration retard 300-7901 cell's growth, reduced protein volume of SGC-7901. 300-7901 cell required more glucose when L-Val supply was subtracted. At same restricted level of L-Val, increasing L-Val to 4 times increased their glucose utilization. Few effect en fetal liver cell growth was found Con-elusion: Increasing L-Leu and restricting L-Val supply can inhibit growth of cancer cell. Gastric cancer uptake high mount of L-Val for both protein synthesis end energy supply through gluconeogenesis.