Post-weaning protein malnutrition induces myocardial dysfunction associated with oxidative stress and altered calcium handling proteins in adult rats.

Hypercaloric low-protein diet may lead to a state of malnutrition found in the low-income population of Northeastern Brazil. Although malnutrition during critical periods in the early life is associated with cardiovascular diseases in adulthood, the mechanisms of cardiac dysfunction are still unclear. Here we studied the effects of post-weaning malnutrition due to low protein intake induced by a regional basic diet on the cardiac contractility of young adult rats. In vivo arterial hemodynamic and in vitro myocardial contractility were evaluated in 3-month-old rats. Additionally, protein content of the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA), total phospholamban (PLB) and phosphorylated at serine 16 (p-Ser(16)-PLB), α2-subunit of the Na(+)/K(+)-ATPase (α2-NKA), and Na(+)/Ca(2+) exchanger (NXC) and in situ production of superoxide anion (O2(-)) were measured in the heart. Blood pressure and heart rate increased in the post-weaning malnourished (PWM) rats. Moreover, malnutrition decreased twitch force and inotropic responses of the isolated cardiac muscle. Protein expression of SERCA, PLB/SERCA, and p-Ser(16)-PLB/PLB ratios and α2-NKA were decreased without changing NCX. The contraction dependent on transsarcolemmal calcium influx was unchanged but responsiveness to Ca(2+) and tetanic peak contractions were impaired in the PWM group. Myocardial O2(-) production was significantly increased by PWM. Our data demonstrated that this hypercaloric low-protein diet in rats is associated with myocardial dysfunction, altered expression of major calcium handling proteins, and increased local oxidative stress. These findings reinforce the attention needed for pediatric care, since chronic malnutrition in early life is related to increased cardiovascular risk in adulthood. Graphical Abstract.

Fibroblast growth factor 21 and protein energy wasting in hemodialysis patients.

INTRODUCTION: Protein energy wasting (PEW) is the most important risk factor for morbidity and mortality in hemodialysis patients. Inadequate dietary protein intake is a frequent cause of PEW. Recent studies have identified fibroblast growth factor 21 (FGF21) as an endocrine protein sensor. This study aims to investigate the potential of FGF21 as a biomarker for protein intake and PEW and to investigate intradialytic FGF21 changes. METHODS: Plasma FGF21 was measured using an enzyme-linked immunoassay. Complete intradialytic dialysate and interdialytic urinary collections were used to calculate 24-h urea excretion and protein intake. Muscle mass was assessed using the creatinine excretion rate and fatigue was assessed using the Short Form 36 and the Checklist Individual Strength. RESULTS: Out of 59 hemodialysis patients (65 ± 15 years, 63% male), 39 patients had a low protein intake, defined as a protein intake less than 0.9 g/kg/24-h. Patients with a low protein intake had nearly twofold higher plasma FGF21 compared to those with an adequate protein intake (FGF21 1370 [795-4034] pg/mL versus 709 [405-1077] pg/mL;P < 0.001). Higher plasma FGF21 was associated with higher odds of low protein intake (Odds Ratio: 3.18 [1.62-7.95] per doubling of FGF21; P = 0.004), independent of potential confounders. Higher plasma FGF21 was also associated with lower muscle mass (std ß: -0.34 [-0.59;-0.09];P = 0.009), lower vitality (std ß: -0.30 [-0.55;-0.05];P = 0.02), and more fatigue (std ß: 0.32 [0.07;0.57];P = 0.01). During hemodialysis plasma FGF21 increased by 354 [71-570] pg/mL, corresponding to a 29% increase. CONCLUSION: Higher plasma FGF21 is associated with higher odds of low protein intake in hemodialysis patients. Secondarily, plasma FGF21 is also associated with lower muscle mass, less vitality, and more fatigue. Lastly, there is an intradialytic increase in plasma FGF21. FGF21 could be a valuable marker allowing for objective assessment of PEW.

Nutritional recovery with a soybean diet impaired the glucagon response but did not alter liver gluconeogenesis in the adult offspring of rats deprived of protein during pregnancy and lactation.

Nutritional recovery of early malnutrition with a soybean diet reduces liver glycogen stores in the fed state and produces liver insulin resistance. We investigated whether nutritional recovery on a soybean flour diet alters hepatic gluconeogenesis in the adult offspring of rats deprived of protein during pregnancy and lactation. Male rats from mothers that were fed either 17% (C) or 6% (L) protein during pregnancy and lactation were maintained on a 17% casein (CC, n = 16 and LC, n = 17), 17% soybean flour (CS, n = 10 and LS, n = 10), or 6% casein (LL, n = 10) diet after weaning. The soybean diet reduced basal serum glucose (soybean diet, 5.6 ± 0.6 mmol/L vs. casein diet, 6.2 ± 0.6 mmol/L; p < 0.05) but increased alanine aminotransferase mRNA/GAPDH (soybean diet, 0.062 ± 0.038 vs. casein diet, 0.024 ± 0.011; p < 0.01), phosphoenolpyruvate carboxykinase mRNA/GAPDH (soybean diet, 1.53 ± 0.52 vs. casein diet, 0.95 ± 0.43; p < 0.05), and glycerokinase protein content (soybean diet, 0.86 ± 0.08 vs. casein diet, 0.75 ± 0.11; p < 0.05). The serum glucose concentration (recovered groups, 5.6 ± 0.5 mmol/L vs. control groups, 6.2 ± 0.7 mmol/L; p < 0.05) and phosphoenolpyruvate carboxykinase activity (recovered groups, 2.8 ± 0.6 µU/mg vs. control groups, 3.6 ± 0.6 µU/mg; p < 0.05) were decreased in rats subjected to protein restriction in early life. The glucose area under the curve during the pyruvate tolerance test did not differ among groups, whereas glucose area under the curve after glucagon infusion was reduced by early malnutrition (recovered groups, 4210 ± 572 mg/dL·40 min vs. control groups, 4493 ± 688 mg/dL·40 min; p < 0.001) and by the soybean diet (soybean diet, 3995 ± 500 mg/dL·40 min vs. casein diet, 4686 ± 576 mg/dL·40 min; p < 0.05). Thus, the soybean diet impaired the response to glucagon but did not alter gluconeogenesis.

Reduced glucose-induced insulin secretion in low-protein-fed rats is associated with altered pancreatic islets redox status.

In the present study, we investigated the relationship between early life protein malnutrition-induced redox imbalance, and reduced glucose-stimulated insulin secretion. After weaning, male Wistar rats were submitted to a normal-protein-diet (17%-protein, NP) or to a low-protein-diet (6%-protein, LP) for 60 days. Pancreatic islets were isolated and hydrogen peroxide (H2 O2 ), oxidized (GSSG) and reduced (GSH) glutathione content, CuZn-superoxide dismutase (SOD1), glutathione peroxidase (GPx1) and catalase (CAT) gene expression, as well as enzymatic antioxidant activities were quantified. Islets that were pre-incubated with H2 O2 and/or N-acetylcysteine, were subsequently incubated with glucose for insulin secretion measurement. Protein malnutrition increased CAT mRNA content by 100%. LP group SOD1 and CAT activities were 50% increased and reduced, respectively. H2 O2 production was more than 50% increased whereas GSH/GSSG ratio was near 60% lower in LP group. Insulin secretion was, in most conditions, approximately 50% lower in LP rat islets. When islets were pre-incubated with H2 O2 (100 µM), and incubated with glucose (33 mM), LP rats showed significant decrease of insulin secretion. This effect was attenuated when LP islets were exposed to N-acetylcysteine.

Genetic Engineering: A Possible Strategy for Protein-Energy Malnutrition Regulation.

Protein-energy malnutrition (PEM) has adversely affected the generations of developing countries. It is a syndrome that in severity causes death. PEM generally affects infants of 1-5 age group. This manifestation is maintained till adulthood in the form of poor brain and body development. The developing nations are continuously making an effort to curb PEM. However, it is still a prime concern as it was in its early years of occurrence. Transgenic crops with high protein and enhanced nutrient content have been successfully developed. Present article reviews the studies documenting genetic engineering-mediated improvement in the pulses, cereals, legumes, fruits and other crop plants in terms of nutritional value, stress tolerance, longevity and productivity. Such genetically engineered crops can be used as a possible remedial tool to eradicate PEM.

PEX2 is the E3 ubiquitin ligase required for pexophagy during starvation.

Peroxisomes are metabolic organelles necessary for anabolic and catabolic lipid reactions whose numbers are highly dynamic based on the metabolic need of the cells. One mechanism to regulate peroxisome numbers is through an autophagic process called pexophagy. In mammalian cells, ubiquitination of peroxisomal membrane proteins signals pexophagy; however, the E3 ligase responsible for mediating ubiquitination is not known. Here, we report that the peroxisomal E3 ubiquitin ligase peroxin 2 (PEX2) is the causative agent for mammalian pexophagy. Expression of PEX2 leads to gross ubiquitination of peroxisomes and degradation of peroxisomes in an NBR1-dependent autophagic process. We identify PEX5 and PMP70 as substrates of PEX2 that are ubiquitinated during amino acid starvation. We also find that PEX2 expression is up-regulated during both amino acid starvation and rapamycin treatment, suggesting that the mTORC1 pathway regulates pexophagy by regulating PEX2 expression levels. Finally, we validate our findings in vivo using an animal model.

Altered gene expression in hippocampus and depressive-like behavior in young adult female mice by early protein malnutrition.

Perinatal development represents a critical period in the life of an individual. A common cause of poor development is that which comes from undernutrition or malnutrition. In particular, protein deprivation during development has been shown to have deep deleterious effects on brain's growth and plasticity. Early-life stress has also been linked with an increased risk to develop different psychopathologies later in life. We have previously shown that perinatal protein malnutrition in mice leads to the appearance of anxiety-related behaviors in the adulthood. We also found evidence that the female offspring was more susceptible to the development of depression-related behaviors. In the present work, we further investigated this behavior together with its molecular bases. We focused our study on the hippocampus, as it is a structure involved in coping with stressful situations. We found an increase in immobility time in the forced swimming test in perinatally malnourished females, and an alteration in the expression of genes related with neuroplasticity, early growth response 1, calcineurin and c-fos. We also found that perinatal malnutrition causes a reduction in the number of neurons in the hippocampus. This reduction, together with altered gene expression, could be related to the increment in immobility time observed in the forced swimming test.

DNA Methylation Signatures of Early Childhood Malnutrition Associated With Impairments in Attention and Cognition.

BACKGROUND: Early childhood malnutrition affects 113 million children worldwide, impacting health and increasing vulnerability for cognitive and behavioral disorders later in life. Molecular signatures after childhood malnutrition, including the potential for intergenerational transmission, remain unexplored. METHODS: We surveyed blood DNA methylomes (~483,000 individual CpG sites) in 168 subjects across two generations, including 50 generation 1 individuals hospitalized during the first year of life for moderate to severe protein-energy malnutrition, then followed up to 48 years in the Barbados Nutrition Study. Attention deficits and cognitive performance were evaluated with the Connors Adult Attention Rating Scale and Wechsler Abbreviated Scale of Intelligence. Expression of nutrition-sensitive genes was explored by quantitative reverse transcriptase polymerase chain reaction in rat prefrontal cortex. RESULTS: We identified 134 nutrition-sensitive, differentially methylated genomic regions, with most (87%) specific for generation 1. Multiple neuropsychiatric risk genes, including COMT, IFNG, MIR200B, SYNGAP1, and VIPR2 showed associations of specific methyl-CpGs with attention and IQ. IFNG expression was decreased in prefrontal cortex of rats showing attention deficits after developmental malnutrition. CONCLUSIONS: Early childhood malnutrition entails long-lasting epigenetic signatures associated with liability for attention and cognition, and limited potential for intergenerational transmission.

Protein-energy malnutrition is frequent and precocious in children with cri du chat syndrome.

Protein-energy malnutrition (PEM) is poorly reported in cri du chat syndrome (CDCS) (OMIM #123450), a genetic disease that causes developmental delay and global growth retardation. The objective was to determine the nutritional status at different ages in children with CDCS and factors associated with PEM. A questionnaire focused on growth and nutritional care was sent to 190 families. Among 36 analyzable questionnaires, growth and nutritional indices compatible with PEM occurred in 47% of patients: 19% before 6 months of age, 24% between 6-12 months and 34% after 12 months. Eight patients received enteral feeding. Speech therapy for swallowing education was performed more often in malnourished children (63% vs. 22%, P < 0.02). PEM is frequent and occurs early in this disease, requiring closed nutritional monitoring.

Protein energy-malnutrition: does the in vitro zinc sulfate supplementation improve chromosomal damage repair?

Protein-energy malnutrition (PEM) is originated by a cellular imbalance between nutrient/energy supply and body's demand. Induction of genetic damage by PEM was reported. The purpose of this study was to determine the genetic effect of the in vitro zinc sulfate (ZnSO4) supplementation of cultured peripheral blood lymphocytes from children with PEM. Twenty-four samples from 12 children were analyzed. Anthropometric and biochemical diagnosis was made. For the anthropometric assessment, height-for-age index, weight-for-age index, and weight-for-height index were calculated (WHO, 2005). Micronutrient status was evaluated. A survey for assessed previous exposure to potentially genotoxic agents was applied. Results were statistically evaluated using paired sample t test and χ (2) test. Each sample was fractionated and cultured in two separate flasks to performed two treatments. One was added with 180 µg/dl of ZnSO4 (PEMs/ZnSO4) and the other remains non-supplemented (PEMs). Cytotoxic effects and chromosomal damage were assessed using the cytokinesis-block micronucleus assay (CBMN). All participants have at least one type of malnutrition and none have anemia, nor iron, folate, vitamin A, and zinc deficiency. All PEMs/ZnSO4 samples have a significant reduction in the micronucleus (MNi) frequency compared with PEMs (t = 6.25685; p < 0.001). Nuclear division index (NDI) increase in PEMs/ZnSO4 (t = -17.4226; p < 0.001). Nucleoplasmic bridge (NPBs) frequency was four times smaller in PEMs/ZnSO4 (χ (2) = 40.82; p < 0.001). No nuclear buds (NBuds) were observed. Cytotoxic effects and chromosomal damage observed in children suffering from PEM can be repaired in vitro with zinc sulfate supplementation.

Oxidative status and DNA damage in chidren with marasmic malnutrition.

Malnutrition as a lack of several substances containing antioxidants such as vitamins and micronutrients, while showing a predisposition for lipid peroxidation and DNA damage, is also characterized by a slowing down of the metabolic processes, which may then have protective properties against DNA damage due to a reduction in endogenous free radical production. This study aimed to examine the oxidative status and DNA damage in cases of marasmus. The study comprised 28 infants aged 6-24 months with marasmus only and 28 age-matched healthy infants. DNA damage was examined by the alkali single cell electrophoresis method (Comet assay) on mononuclear leukocytes. The total oxidant status (TOS) and total antioxidant status (TAS) were measured by colormetric auto-analyzer and the oxidative stress index (OSI) was calculated. The TOS, TAS, and OSI levels of the patient group were found to be significantly lower compared to the control group (P < 0.01, P < 0.01, P < 0.01, respectively). No statistically significant difference was found between the two groups in terms of mononuclear leukocyte DNA damage (P > 0.05). The findings of this study showed that in marasmus cases, the oxidative and antioxidative processes, which have a counteractive effect, decreased together. The other results of the study indicate that there is no increase in DNA damage in marasmus cases.

Tissue-specific selection of reference genes is required for expression studies in the mouse model of maternal protein undernutrition.

Suboptimal maternal nutrition during gestation results in the establishment of long-term phenotypic changes and an increased disease risk in the offspring. To elucidate how such environmental sensitivity results in physiological outcomes, the molecular characterisation of these offspring has become the focus of many studies. However, the likely modification of key cellular processes such as metabolism in response to maternal undernutrition raises the question of whether the genes typically used as reference constants in gene expression studies are suitable controls. Using a mouse model of maternal protein undernutrition, we have investigated the stability of seven commonly used reference genes (18s, Hprt1, Pgk1, Ppib, Sdha, Tbp and Tuba1) in a variety of offspring tissues including liver, kidney, heart, retro-peritoneal and inter-scapular fat, extra-embryonic placenta and yolk sac, as well as in the preimplantation blastocyst and blastocyst-derived embryonic stem cells. We find that although the selected reference genes are all highly stable within this system, they show tissue, treatment and sex-specific variation. Furthermore, software-based selection approaches rank reference genes differently and do not always identify genes which differ between conditions. Therefore, we recommend that reference gene selection for gene expression studies should be thoroughly validated for each tissue of interest.

The liver X-receptor gene promoter is hypermethylated in a mouse model of prenatal protein restriction.

Prenatal nutrition as influenced by the nutritional status of the mother has been identified as a determinant of adult disease. Feeding low-protein diets during pregnancy in rodents is a well-established model to induce programming events in offspring. We hypothesized that protein restriction would influence fetal lipid metabolism by inducing epigenetic adaptations. Pregnant C57BL/6J mice were exposed to a protein-restriction protocol (9% vs. 18% casein). Shortly before birth, dams and fetuses were killed. To identify putative epigenetic changes, CG-dinucleotide-rich region in the promoter of a gene (CpG island) methylation microarrays were performed on DNA isolated from fetal livers. Two hundred four gene promoter regions were differentially methylated upon protein restriction. The liver X-receptor (Lxr) alpha promoter was hypermethylated in protein-restricted pups. Lxr alpha is a nuclear receptor critically involved in control of cholesterol and fatty acid metabolism. The mRNA level of Lxra was reduced by 32% in fetal liver upon maternal protein restriction, whereas expression of the Lxr target genes Abcg5/Abcg8 was reduced by 56% and 51%, respectively, measured by real-time quantitative PCR. The same effect, although less pronounced, was observed in the fetal intestine. In vitro methylation of a mouse Lxra-promoter/luciferase expression cassette resulted in a 24-fold transcriptional repression. Our study demonstrates that, in mice, protein restriction during pregnancy interferes with DNA methylation in fetal liver. Lxra is a target of differential methylation, and Lxra transcription is dependent on DNA methylation. It is tempting to speculate that perinatal nutrition may influence adult lipid metabolism by DNA methylation, which may contribute to the epidemiological relation between perinatal/neonatal nutrition and adult disease.

Protein-energy malnutrition contributes to increased structural chromosomal alteration frequencies in Argentinean children.

The relationship between protein-energy malnutrition and genetic damage has been studied in human beings and laboratory animals, but results are still conflicting. The aim of the present study was to assess the induction of structural chromosomal aberrations in peripheral blood lymphocytes of children with primary protein-energy malnutrition. A case-control study was performed. Samples were obtained from 25 primary malnourished infants (mean age, 22 months; range, 1-66 months). The control group consisted of 25 eutrophic children from the same population who were matched 1:1 by age and sex. Anthropometric and clinic evaluations were performed to assess nutritional condition. Before blood collection, we interviewed each individual's parent to complete a semi-structural survey specifying age, dietary habits, viral or bacterial diseases; previous exposure to diagnostic x-rays; and use of therapeutic drugs. After 48 hours, 100 cultured lymphocytes were analyzed per patient. Statistical analysis was performed using the Epi Dat 3.0 program (P < or = .05). The chromosomal aberration frequency was nearly 7 times higher in malnourished infants than in controls (14.61% vs 2.2%, respectively). This difference was statistically significant (P < .001) and may be explained by the occurrence of achromatic lesions, breaks, and telomeric associations. DNA damage could be attributed to several factors: severe deficiency of essential nutrients (ie zinc, iron, and vitamin A) required in the synthesis of DNA maintenance factors; deterioration of repair mechanisms allowing the persistence of an unusually high number of structural chromosomal aberrations; and/or the absence of specific factors needed to protect the cell against oxidative DNA damage.

Glutathione S-transferase polymorphisms may be associated with risk of oedematous severe childhood malnutrition.

It has been estimated that more than 50 % of deaths before the age of 5 years have undernutrition as an underlying cause. Severe childhood malnutrition, an extreme form of undernutrition, occurs as oedematous and non-oedematous syndromes. The reasons why only some children develop oedematous severe childhood malnutrition (OSCM) have remained elusive, but the heterogeneity of clinical appearances among children from relatively homogeneous backgrounds suggests that interindividual variation in susceptibility to OSCM may exist. We investigated variants of four glutathione S-transferase (GST) genes in a retrospective study among subjects (n 136) previously admitted to the Tropical Metabolism Research Unit, Jamaica, for the treatment of either OSCM (cases) or non-oedematous severe childhood malnutrition (controls). We found that GSTP1 Val(105) homozygotes were significantly more common among the cases (odds ratio (OR) 3.5; 95 % CI 1.1, 10.8). We also found an association of borderline significance between non-deletion GSTT1 genotypes (i.e. +/+ or +/0) and OSCM (OR 2.4; 95 % CI 1.0, 5.9). There was no significant association between OSCM and any of the other GST variants. These preliminary findings suggest that genetic variation within the GST superfamily may contribute to the risk of OSCM. Additional, larger data sets and studies of variants in other candidate genes are required in order to properly assess the true contribution, if any, of genetic variation to risk of OSCM. Such studies may improve our understanding of the causes of clinical heterogeneity in malnutrition.

Differential gene expression in lymphocytes from malnourished children.

Malnutrition, which is widespread in developing countries, may be particularly devastating during childhood, when tissue development is occurring and nutrient requirements are great. Since protein-energy malnutrition potentially involves many cellular alterations, we have evaluated gene expression changes in lymphocytes from malnourished children using differential hybridization cloning. A cDNA library was generated from well-nourished children and differential screenings were performed with cDNAs obtained from well-nourished and malnourished children who presented with bacterial gastrointestinal infections. Differential expression was detected for genes involved in cell development and differentiation, and for genes involved in lymphocyte and mitochondrial functions. The genes detected in the present study suggest mechanisms for the changes in cell growth and immune function that are associated with protein-energy malnutrition. Two down-regulated genes in malnourished children may represent mechanisms of protection against immunosuppression. This finding clearly merits further investigation.

Identification of genes enhanced by protein-calorie malnutrition by differential display polymerase chain reaction (expression of fibrinogen B beta chain, B cell translocation gene 1 and thyroid hormone responsive protein genes).

Protein-calorie malnutrition (PCM), as one of global health problems, arises during protein and/or energy deficit due to disease and nutritional inadequacy. Previously, we showed that PCM elicited oxidative stress with activation of the phase II detoxifying gene expression, which was reversed by cysteine supplementation. As part of the attempts to identify the cellular adaptive responses and the associated gene expression during PCM, the current study was initiated to analyze the genes differentially expressed in the rat during PCM. Among 1,916 bands amplified, 85 putative differentially amplified bands were enhanced by PCM in the liver, while the expression of 64 bands was suppressed. Northern and/or reverse transcription-polymerase chain reaction (RT-PCR) analyses revealed that PCM increased the expression of fibrinogen B beta chain, B cell translocation gene I (BTGI) and thyroid hormone responsive protein (THRP) mRNAs. The increase in the hepatic fibrinogen B beta chain mRNA was not prevented by cysteine supplementation, whereas cysteine decreased the enhancement in the rGSTA2 and microsomal epoxide hydrolase mRNA expression. Cysteine was also active in reversing the increase in BTG1 mRNA during PCM. This was supported by the increase in BTG1 mRNA in H4IIE cells exposed to sulfur amino acid-deprived medium. Northern blot analysis revealed that THRP, highly expressed in the brain in a tissue-specific manner, was induced by PCM and that cysteine supplementation abolished the THRP induction. Conversely, the level of hepatic albumin mRNA was markedly decreased by PCM, which was partially restored by cysteine supplementation. Differential display RT-PCR analysis allowed us to identify the genes that are responsive to oxidative stress during PCM and to characterize the differential role of cysteine on the expression of the fibrinogen B beta chain, BTG1 and THRP genes as a homeostatic adaptive response during protein deficiency.

Nutritional regulation of visceral markers in rat liver and cultured hepatoma cells.

Protein malnutrition in humans and other animals is consistently associated with a decreased concentration of circulating serum albumin, transthyretin (TTR), and insulin-like growth factor-I (IGF-I). The molecular mechanisms for regulation of the three polypeptides by dietary protein remain to be completely elucidated. The abundance of albumin, TTR and IGF-I mRNA is decreased in liver of juvenile rats consuming insufficient amounts of protein. Moreover, protein restriction specifically decreases the abundance of albumin and TTR nuclear transcripts, indicating that the reduction in mRNA levels for these two genes is caused at least partly by a decrease in gene transcription. Expression of several other genes transcribed at a high level in the liver is also decreased under conditions of dietary protein restriction, suggesting that the level/functional activity of liver-enriched transcription factor(s) might be decreased under these conditions. Limitation of cultured hepatoma cells for a single amino acid also selectively decreases the mRNA levels of several genes with liver-enriched expression, including albumin and TTR. The decrease in albumin mRNA is caused partly by decreased albumin gene transcription and partly by destabilization of albumin mRNA.

High prevalence of hyperhomocysteinemia in chronic alcoholism: the importance of the thermolabile form of the enzyme methylenetetrahydrofolate reductase (MTHFR).

Alcoholism is related to malnutrition and low levels of several vitamins that take part in the metabolism of homocysteine. The objective of the study was to analyze the prevalence of hyperhomocysteinemia in patients with heavy alcohol intake and the factors on which it depends. Included in the study were 103 hospitalized heavy drinkers (i.e., patients with an intake of alcohol greater than 80 g per day). Serum homocysteine, folate, and vitamin B(12) levels, plasma vitamin B(6) levels, and CT677 polymorphisms of methylenetetrahydrofolate reductase (MTHFR) were determined. We also recorded the intensity of alcoholism, the status of nutrition, and the existence of liver cirrhosis. Determination of biochemical data was repeated after 15 days of withdrawal. Serum homocysteine levels were found to be significantly elevated, whereas serum folate and plasma B(6) levels were significantly decreased. Serum homocysteine levels were significantly higher in those heavy drinkers who showed the TT polymorphism of MTHFR, with a prevalence of hyperhomocysteinemia of 84.2% in the homozygote TT, 54.3% in the heterozygote CT, and 31.6% in the normal CC genotype. Serum homocysteine inversely correlated with serum folate, serum B(12), and plasma B(6) levels. We did not find any relation between serum homocysteine and intensity of alcoholism, nutritional status, or liver cirrhosis. Serum folate levels were significantly decreased in heavy drinkers, mainly depending on irregular feeding and malnutrition. After 15 days of withdrawal, serum homocysteine levels significantly decreased, whereas folate, B(12), and B(6) levels significantly increased. The conclusion is that heavy drinkers show a high prevalence of hyperhomocysteinemia related to low levels of folate, B(6), and B(12) and to the TT polymorphism of MTHFR.