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Adipokines are a family of hormones and cytokines with both pro- and anti-inflammatory effects released into the circulation to exert their hormonal effects. Adipokines are closely involved in most metabolic pathways and play an important modulatory role in lipid and carbohydrate homeostasis as they are involved in the pathophysiology of most metabolic disorders. Incretin-based therapy is a newly introduced class of antidiabetic drugs that restores euglycemia through several cellular processes; however, its effect on adipokines expression/secretion is not fully understood. In this review, we propose that incretin-based therapy may function through adipokine modulation that may result in pharmacologic properties beyond their direct antidiabetic effects, resulting in better management of diabetes and diabetes-related complications.

Hepatocyte nuclear factor 4 alpha (HNF4) is required for hepatocyte differentiation and regulates expression of genes involved in lipid and carbohydrate metabolism including those that control VLDL secretion and gluconeogenesis. Whereas previous studies have focused on specific genes regulated by HNF4 in metabolism, its overall role in whole-body energy utilization has not been studied. In this study, we used indirect calorimetry to determine the effect of hepatocyte-specific HNF4 deletion (HNF4-KO) in mice on whole-body energy expenditure (EE) and substrate utilization in fed, fasted, and high-fat diet (HFD) conditions. HNF4-KO had reduced resting EE during fed conditions and higher rates of carbohydrate oxidation with fasting. HNF4-KO mice exhibited decreased body mass caused by fat mass depletion despite no change in energy intake and evidence of positive energy balance. HNF4-KO mice were able to upregulate lipid oxidation during HFD, suggesting that their metabolic flexibility was intact. However, only hepatocyte-specific HNF4-KO mice exhibited significant reduction in basal metabolic rate and spontaneous activity during HFD. Consistent with previous studies, hepatic gene expression in HNF4-KO supports decreased gluconeogenesis and decreased VLDL export and hepatic -oxidation in HNF4-KO livers across all feeding conditions. Together, our data suggest that deletion of hepatic HNF4 increases dependence on dietary carbohydrates and endogenous lipids for energy during fed and fasted conditions by inhibiting hepatic gluconeogenesis, hepatic lipid export, and intestinal lipid absorption resulting in decreased whole-body energy expenditure. These data clarify the role of hepatic HNF4 on systemic metabolism and energy homeostasis.

Purpose: Non-alcoholic fatty liver (NAFL) is comorbid to obesity, metabolic syndrome and type 2 diabetes mellitus (T2DM). It is unclear whether NAFLD constitutes a direct risk factor for macrovascular disease in T2DM. This study aimed at revisiting the cardiometabolic traits linked to NADL and micro-/ macrovascular complications in a biethnic Caucasian and African cohort. Methods: Cross-sectional analysis of 568 of T2DM patients (515 Caucasians; 53 Africans) in whom the presence of NAFL was identified by ultrasonography and the cardiometabolic phenotype was exhaustively characterized, including carbohydrate homeostasis, comprehensive lipidogram including Lp(a), cumulative exposure to hyperglycemia, and prevalent micro/macrovascular complications. Results: FL was present in 73% of Caucasians and 36% of Africans (p − in both groups. A marked reduction in diabetic retinopathy (DR), ocular hypertonia and cataracts were found in FL+ of the two ethnicities. In FL+ Caucasians, relative risk of DR was −38%, cataracts −35%, and ocular hypertonia −42%. In FL+ Africans, risk of overall microangiopathy was −66% and that of DR −86%. Conclusions: An inverse association was observed between NAFL and the presence of diabetic retinopathy, cataract and ocular hypertonia. The ophthalmoprotection conferred by liver steatosis was found in Caucasians and Africans. Among the latter, hepatic steatosis was linked to lower lipoprotein(a) levels. There was no association between hepatic steatosis and prevalent macrovascular complications in neither of the two ethnic groups.

In recent years, the possibility of using intranasally administered insulin to treat Alzheimers disease and other cognitive disorders has been widely studied. At the same time, the possibility of its use in the treatment of diabetes mellitus is practically not investigated, which is due to the insufficient study of the molecular mechanisms of its action on the hormonal and metabolic status of the organism. The review discusses literature data and the results of our own research on the role of insulin in the central regulation of energy homeostasis, as well as on the experience of using intranasally administered insulin to correct eating disorders and metabolic and hormonal dysfunctions developing under conditions of experimental diabetes mellitus and metabolic syndrome. In studies involving healthy volunteers, various effects of intranasally administered insulin were shown, including effects on cognitive function, eating behavior and weight loss, and the gender specificity of its action was found. In the course of numerous studies of intranasally administered insulin in animal models of diabetes mellitus, not only stabilization of carbohydrate homeostasis was shown, but also a positive effect in the form of restoration of the functional activity of insulin signaling pathways in the hypothalamus and other parts of the brain. We have presented and analyzed data on the systemic effects of intranasally administered insulin in rodents with experimental models of diabetes mellitus, as well as in healthy individuals.В последние годы широко изучается возможность применения интраназально вводимого инсулина для лечения болезни Альцгеймера и других когнитивных расстройств. В то же время практически не исследуется возможность его применения в рамках терапии сахарного диабета, что во многом связано с недостаточной изученностью молекулярных механизмов его действия на гормональный и метаболический статусы организма. В обзоре обсуждаются данные литературы и результаты собственных исследований о роли инсулина в центральной регуляции энергетического гомеостаза, а также об опыте применения интраназально вводимого инсулина для коррекции нарушений пищевого поведения и метаболических и гормональных дисфункций, развивающихся в условиях экспериментального сахарного диабета и метаболического синдрома. В исследованиях с участием здоровых добровольцев были показаны различные эффекты интраназально вводимого инсулина, в том числе влияние на когнитивные функции, пищевое поведение и снижение массы тела, а также обнаружена гендерная специфичность его действия. В ходе многочисленных исследований интраназально вводимого инсулина на животных моделях сахарного диабета были показаны не только стабилизация углеводного гомеостаза, но и положительное действие в виде восстановления функциональной активности инсулиновых сигнальных путей в гипоталамусе и других отделах мозга. Нами представлены и проанализированы данные о системных эффектах интраназально вводимого инсулина у грызунов с экспериментальными моделями сахарного диабета, а также у здоровых индивидуумов.

The increasing burden of obesity worldwide and its effect on cardiovascular disease (CVD) risk is an opportunity for evaluation of preventive approaches. Both obesity and CVD have a genetic background and polymorphisms within genes which enhance expression of variant proteins that influence CVD in obesity. Genome-based prediction may therefore be a feasible strategy, but the identification of genetically driven risk factors for CVD manifesting as clinically recognized phenotypes is a major challenge. Clusters of such risk factors include hyperglycaemia, hypertension, ectopic liver fat, and inflammation. All involve multiple genetic pathways having complex interactions with variable environmental influences. The factors that make significant contributions to CVD risk include altered carbohydrate homeostasis, ectopic deposition of fat in muscle and liver, and inflammation, with contributions from the gut microbiome. A futuristic model depends on harnessing the predictive power of plausible genetic variants, phenotype reversibility, and effective therapeutic choices based on genotype-phenotype interactions. Inverting disease phenotypes into ideal cardiovascular health metrics could improve genetic and epigenetic assessment, and form the basis of a future model for risk detection and early intervention.

Biological age measures outperform chronological age in predicting various aging outcomes, yet little is known regarding genetic predisposition. We performed genome‐wide association scans of two age‐adjusted biological age measures (PhenoAgeAcceleration and BioAgeAcceleration), estimated from clinical biochemistry markers (Levine et al., 2018; Levine, 2013) in European‐descent participants from UK Biobank. The strongest signals were found in the APOE gene, tagged by the two major protein‐coding SNPs, PhenoAgeAccel—rs429358 (APOE e4 determinant) (p = 1.50 × 10−72); BioAgeAccel—rs7412 (APOE e2 determinant) (p = 3.16 × 10−60). Interestingly, we observed inverse APOE e2 and e4 associations and unique pathway enrichments when comparing the two biological age measures. Genes associated with BioAgeAccel were enriched in lipid related pathways, while genes associated with PhenoAgeAccel showed enrichment for immune system, cell function, and carbohydrate homeostasis pathways, suggesting the two measures capture different aging domains. Our study reaffirms that aging patterns are heterogeneous across individuals, and the manner in which a person ages may be partly attributed to genetic predisposition., A genome‐wide association study for differences in aging rates was performed in the UK Biobank sample using two previously established aging measures. Results suggest that one was associated with genes involved in lipid metabolism and blood pressure, while the other was associated with genes involved in immune functioning. APOE e4 was associated with faster aging in the measure reflecting lipid age, yet paradoxically, was associated with reduced aging in the measure reflecting immune functioning and inflammation.

Insulin plays a significant role in carbohydrate homeostasis as the blood glucose lowering hormone. Glucose-induced insulin secretion (GSIS) is augmented by glucagon-like peptide (GLP-1), a gastrointestinal peptide released in response to ingesting nutriments. The secretion of insulin and GLP-1 is mediated by the binding of nutrients to G protein-coupled receptors (GPCRs) expressed by pancreatic β-cells and enteroendocrine cells, respectively. Therefore, insulin secretagogues and incretin mimetics currently serve as antidiabetic treatments. This study demonstrates the potency of synthetic isoprenoid derivatives of lysophosphatidylcholines (LPCs) to stimulate GSIS and GLP-1 release. Murine insulinoma cell line (MIN6) and enteroendocrinal L cells (GLUTag) were incubated with LPCs bearing geranic acid (1-GA-LPC), citronellic acid (1-CA-LPC), 3,7-dimethyl-3-vinyloct-6-enoic acid (GERA-LPC), and (E)-3,7,11-trimethyl- 3-vinyldodeca-6,10-dienoic acid (1-FARA-LPC). Respective free terpene acids were also tested for comparison. Besides their insulin- and GLP-1-secreting capabilities, we also investigated the cytotoxicity of tested compounds, the ability to intracellular calcium ion mobilization, and targeted GPCRs involved in maintaining lipid and carbohydrate homeostasis. We observed the high cytotoxicity of 1-GERA-LPC and 1-FARA-LPC in contrast 1-CA-LPC and 1-GA-LPC. Moreover, 1-CA-LPC and 1-GA-LPC demonstrated the stimulatory effect on GSIS and 1-CA-LPC augmented GLP-1 secretion. Insulin and GLP-1 release appeared to be GPR40-, GPR55-, GPR119- and GPR120-dependent.

BackgroundGrapevines are commonly infected with one or more viruses causing a significant threat to the sustainability of quality wine grape production worldwide. The recently identified Grapevine red blotch disease (GRBD) significantly affects the yield and quality of wine grapes. It is largely unknown how the red blotch disease affects carbohydrate homeostasis and regulate the source-to-sink relationship in grapevines. We took an integrative approach to determine the consequences of viral infection in commercially grown, two popular wine grape cultivars from distinct locations in the eastern Washington.ResultsThe deep sequencing approach revealed that Grapevine red blotch virus (GRBV) was found in all symptomatic vines, while asymptomatic vines were free of this virus. Analysis of mature berries at commercial harvest in virus-infected vines indicated significant changes in the soluble sugar accumulation along with the increase in leaf sucrose and starch content. To follow up with the altered carbohydrate homeostasis, we analyzed cell wall components in winter canes of virus-infected vines and compared them to their virus-free counterparts. Major cell wall monosaccharide contents and total lignin content was not affected due to red blotch disease in either cultivar. However, high-resolution glycome profiling revealed consistent changes in loosely bound cell wall pectin matrices and tightly bound non-fucosylated xyloglucans in virus-infected vines. Furthermore, in cv. Syrah, co-infection with other viruses leads to additional cell wall compositional variations.ConclusionsThese changes highlighted that virus infection in woody perennial leads to detrimental adjustments in the soluble and storage carbohydrates, and in the cell wall layers that could be attributed to lower vine performance or vine decline in a relatively short time. The information gained from such qualitative cell wall structural fine-tuning could be used in assessing how viruses or other pathogenic agents affect perennial longevity.

The prototypical M13 peptidase, human Neprilysin, functions as a transmembrane “ectoenzyme” that cleaves neuropeptides that regulate e.g. glucose metabolism, and has been linked to type 2 diabetes. The M13 family has undergone a remarkable, and conserved, expansion in the Drosophila genus. Here, we describe the function of Drosophila melanogaster Neprilysin-like 15 (Nepl15). Nepl15 is likely to be a secreted protein, rather than a transmembrane protein. Nepl15 has changes in critical catalytic residues that are conserved across the Drosophila genus and likely renders the Nepl15 protein catalytically inactive. Nevertheless, a knockout of the Nepl15 gene reveals a reduction in triglyceride and glycogen storage, with the effects likely occurring during the larval feeding period. Conversely, flies overexpressing Nepl15 store more triglycerides and glycogen. Protein modeling suggests that Nepl15 is able to bind and sequester peptide targets of catalytically active Drosophila M13 family members, peptides that are conserved in humans and Drosophila, potentially providing a novel mechanism for regulating the activity of neuropeptides in the context of lipid and carbohydrate homeostasis.

The projected impact of global warming on coffee production may require the heat-adapted genotypes in the next decades. To identify thermotolerance cellular strategies, we compared the effect of elevated temperature on two commercialCoffea arabicaL. genotypes exploring leaf physiology, transcriptome and carbohydrate/protein composition. Growth temperatures were 23/19°C (day/night), as optimal condition (OpT), and 30/26°C (day/night) as a possible warmer scenario (WaT). The cv. Acauã showed lower levels of leaf temperature under both conditions compared to cv. Catuaí, whereas slightly or no differences for other leaf physiological parameters. Therefore, to explore thermoregulatory pathways the leaf transcriptome was examined using RNAseq. Genotypes showed a marked number of differentially-expressed genes (DEGs) under OpT, however DEGs strongly decrease in both at WaT condition indicating a transcriptional constraint. DEGs responsive to WaT revealed shared and genotype-specific genes mostly related to carbohydrate metabolism. Under OpT, leaf starch content was greater in cv. Acauã although the levels of leaf starch, sucrose, and leaf protein decreased in both genotypes as WaT was imposed. These findings indicate that genotypes with a greater capacity to maintain carbohydrate homeostasis under temperature fluctuations could be more thermotolerant and which may be useful in breeding for a changing climate.HIGHLIGHTIn response to warming, transcriptional differences decrease in coffee genotypes hampering breeding programs. Differences in gene expression and sugar levels confirm intraspecific variation associating thermotolerance to maintenance of energetic homeostasis.

Diabetes mellitus is a chronic, life-threatening metabolic disorder that occurs worldwide. Despite an increase in the knowledge of the risk factors that are associated with diabetes mellitus, its worldwide prevalence has continued to rise; thus, necessitating more research into its aetiology. Recent researches are beginning to link a dysregulation of the circadian rhythm to impairment of intermediary metabolism; with evidences that circadian rhythm dysfunction might play an important role in the aetiology, course or prognosis of some cases of diabetes mellitus. These evidences thereby suggest possible relationships between the circadian rhythm regulator melatonin, and diabetes mellitus. In this review, we discuss the roles of the circadian rhythm in the regulation of the metabolism of carbohydrates and other macronutrients; with emphasis on the importance of melatonin and the impacts of its deficiency on carbohydrate homeostasis. Also, the possibility of using melatonin and its analogs for the “prophylaxis” or management of diabetes mellitus is also considered.

Nowadays, an acute myocardial infarction is one of the leading causes of mortality among the population. The EHS-DH registry data clearly illustrate the association between the comorbidities and high mortality following acute myocardial infarction during a year period of follow up. The pronounced influence of carbohydrate metabolism disturbances on the survival of such patients has already been reported. The aim of the study was to analyze the immune inflammation relationships based on assessing calprotectin and the parameters of lipid and carbohydrate metabolism, to evaluate the presence and nature of the relationship between these parameters and carbohydrate metabolism parameters based on the study of blood glucose, insulin and insulin resistance (by the indices HOMA, QUICKI, Caro), anthropometric indicators and inflammatory indicators (monocyte and neutrophile levels). Materials and methods. The study included 64 patients (mean age 65, 31 ± 1.62 years) with acute myocardial infarction and concomitant diabetes mellitus type 2. The design of the study included the primary laboratory investigation of patients during the first day since the onset of acute myocardial infarction with the elevation of the ST segment before the initiation of thrombolytic therapy or percutaneous intervention. The direct correlation between the calprotectin concentration and the HOMA insulin resistance index (R = 0.52; p 0.05 and R = 0.18; p> 0.05, respectively). Conclusions. The increase in the body mass index and the activity of serum monocytes and neutrophils is associated with high concentrations of calprotectin that is accompanied by disturbances of carbohydrate homeostasis towards the growth of insulin resistance and changes of lipidograms of proatherrogenic nature.

Methylmercury (MeHg) is a well-known neurotoxicant; however, its role in metabolic diseases has been gaining wider attention. We have previously shown that MeHg causes metabolic alterations in Caenorhabditis elegans, leading to decreased nicotinamide adenine dinucleotide cofactor, mitochondrial dysfunction, and oxidative stress. We were, therefore, interested in whether MeHg also affects nutrient metabolism, particularly lipid homeostasis, which may contribute to the development of metabolic conditions such as obesity or metabolic syndrome (MS). RNA from wild-type worms exposed to MeHg was collected immediately after treatment and used for gene expression analysis by DNA microarray. MeHg differentially regulated 215 genes, 17 genes involved in lipid homeostasis, and 12 genes involved in carbohydrate homeostasis. Of particular interest was cebp-1, the worm ortholog to human C/EBP, a pro-adipogenic transcription factor implicated in MS. MeHg increased the expression of cebp-1 as well as pro-adipogenic transcription factors sbp-1 and nhr-49, triglyceride synthesis enzyme acl-6, and lipid transport proteins vit-2 and vit-6. Concurrent with the altered gene expression, MeHg increased triglyceride levels, lipid storage, and feeding behaviors. Worms expressing mutant cebp-1 were protected from MeHg-induced alterations in lipid content, feeding behaviors, and gene expression, highlighting the importance of this transcription factor in the worm’s response to MeHg. Taken together, our data demonstrate that MeHg induces biochemical, metabolic, and behavioral changes in C. elegans that can lead to metabolic dysfunction.

The ability to accurately predict complex trait phenotypes from genetic and genomic data are critical for the implementation of personalized medicine and precision agriculture; however, prediction accuracy for most complex traits is currently low. Here, we used data on whole genome sequences, deep RNA sequencing, and high quality phenotypes for three quantitative traits in the ∼200 inbred lines of the Drosophila melanogaster Genetic Reference Panel (DGRP) to compare the prediction accuracies of gene expression and genotypes for three complex traits. We found that expression levels (r = 0.28 and 0.38, for females and males, respectively) provided higher prediction accuracy than genotypes (r = 0.07 and 0.15, for females and males, respectively) for starvation resistance, similar prediction accuracy for chill coma recovery (null for both models and sexes), and lower prediction accuracy for startle response (r = 0.15 and 0.14 for female and male genotypes, respectively; and r = 0.12 and 0.11, for females and male transcripts, respectively). Models including both genotype and expression levels did not outperform the best single component model. However, accuracy increased considerably for all the three traits when we included gene ontology (GO) category as an additional layer of information for both genomic variants and transcripts. We found strongly predictive GO terms for each of the three traits, some of which had a clear plausible biological interpretation. For example, for starvation resistance in females, GO:0033500 (r = 0.39 for transcripts) and GO:0032870 (r = 0.40 for transcripts), have been implicated in carbohydrate homeostasis and cellular response to hormone stimulus (including the insulin receptor signaling pathway), respectively. In summary, this study shows that integrating different sources of information improved prediction accuracy and helped elucidate the genetic architecture of three Drosophila complex phenotypes.

The insulin receptor (IR) and insulin-like growth factor 1 receptor (IGF1-R) play key roles in growth, regulation of nutrient metabolism and carbohydrate homeostasis. Insulin-like molecules in prokaryotes and other early life have been reported. However, an account of metabolic effects of insulin, transcriptomic evidence of expression of glucose transporting channels (GLUT) and homology modelling of IR and IGF1-R like proteins in unicellular life-forms have yet to be established. Acanthamoeba spp. has existed for about 2 billion years and is one of the earliest mitochondriate unicellular eukaryotic cells on Earth. Despite Acanthamoeba spp. being grown in a medium called peptone-yeast-glucose (PYG) for over 50 years, the mechanism and regulation of glucose uptake by IR or IGF1-R molecules in this microbe has not yet been reported. Several methods were utilized to validate the effects of insulin on trophozoites of A. castellanii, including: growth assays with insulin, estimation of glucose and potassium (K+) entry into the cell, and histology showing anabolic effects on proteins. Bioinformatic computational tools and homology modeling demonstrated the involvement of IR like proteins, GLUT, and adapter proteins in mediating the IR cascade. Growth assays showed proliferative effects in a dose range of 2.98–5.97 µmol/mL of insulin. After insulin exposure, A. castellanii trophozoites displayed enhanced Periodic acid-Sciff (PAS) staining. Amino acid sequence similarities and homology modelling revealed ACA1_163470 in Acanthamoeba spp. to be a homolog of human-IR. Acanthamoeba protein ACA1_336150 shares similarities with IGF1-R. Additionally, some proteins like ACA1_060920 have attributes of GLUT like channels on homology modelling and show similarity with human GLUT. Knowledge of IR and insulin effects in Acanthamoeba spp. contributes to its biology and advances current understanding behind the evolution of IR and IGF1-R signalling cascade.

Human exposure to bisphenol A (BPA) could favor obesity and related metabolic disorders such as hepatic steatosis. Investigations in rodents have shown that these deleterious effects are observed not only when BPA is administered during the adult life but also with different protocols of perinatal exposure. Whether perinatal BPA exposure could pose a risk in human is currently unknown, and thus appropriate in vitro models could be important to tackle this major issue. Accordingly, we determined whether long-term BPA treatment could induce steatosis in human HepaRG cells by using a protocol mimicking perinatal exposure. To this end, the kinetics of expression of seven proteins differentially expressed during liver development was determined during a 4-week period of cell culture required for proliferation and differentiation. By analogy with data reported in rodents and humans, our results indicated that the period of cell culture around day 15 and day 18 after seeding could be considered as the "natal" period. Consequently, HepaRG cells were treated for 3 weeks with BPA (from 0.2 to 2000 nM), with a treatment starting during the proliferating period. BPA was able to induce steatosis with a nonmonotonic dose response profile, with significant effects on neutral lipids and triglycerides observed for the 2 nM concentration. However, the expression of many enzymes involved in lipid and carbohydrate homeostasis was unchanged in exposed HepaRG cells. The expression of other potential BPA targets and enzymes involved in BPA biotransformation was also determined, giving answers as well as new questions regarding the mechanisms of action of BPA. Hence, HepaRG cells provide a valuable model that can prove useful for the toxicological assessment of endocrine disruptors on hepatic metabolisms, in particular in the developing liver. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1024-1036, 2017.

Aging is a complex phenomenon caused by the time-dependent loss of cellular homeodynamics and consequently of physiological organismal functions. This process is affected by both genetic and environmental (e.g., diet) factors, as well as by their constant interaction. Consistently, deregulation of nutrient sensing and signaling pathways is considered a hallmark of aging. Nutrigenomics is an emerging scientific discipline that studies changes induced by diet on the genome and thus it considers the intersection of three topics, namely health, diet, and genomics. Model organisms, such as the fruit fly Drosophila melanogaster, have been successfully used for in vivo modeling of higher metazoans aging and for nutrigenomic studies. Drosophila is a well-studied organism with sophisticated genetics and a fully annotated sequenced genome, in which ~ 75% of human disease-related genes have functional orthologs. Also, flies have organs/tissues that perform the equivalent functions of most mammalian organs, while discrete clusters of cells maintain insect carbohydrate homeostasis in a way similar to pancreatic cells. Herein, we discuss the mechanistic connections between nutrition and aging in Drosophila, and how this model organism can be used to study the effect of different diets (including natural products and/or their derivatives) on higher metazoans longevity. Electronic supplementary material The online version of this article (10.1186/s12263-019-0638-6) contains supplementary material, which is available to authorized users.

Angiopoietin-like 3 (ANGPTL3) is a regulator of plasma triglyceride (TRG) levels due to its inhibitory action on the activity of lipoprotein lipase (LPL). ANGPTL3 is proteolytically cleaved by proprotein convertases to generate an active N-terminal domain, which forms a complex with ANGPTL8 orchestrating LPL inhibition. ANGPTL3-4-8 mouse model studies indicate that these three ANGPTL family members play a significant role in partitioning the circulating TRG to specific tissues according to nutritional states. Recent data indicate a positive correlation of ANGPTL3 with plasma glucose, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR) in insulin-resistant states. The aim of this review is to critically present the metabolic effects of ANGPTL3, focusing on the possible mechanisms involved in the dysregulation of carbohydrate homeostasis by this protein. Heterozygous and homozygous carriers of ANGPTL3 loss-of-function mutations have reduced risk for type 2 diabetes mellitus. Suggested mechanisms for the implication of ANGPTL3 in carbohydrate metabolism include the (i) increment of free fatty acids (FFAs) owing to the enhancement of lipolysis in adipose tissue, which can induce peripheral as well as hepatic insulin resistance; (ii) promotion of FFA flux to white adipose tissue during feeding, leading to the attenuation of de novo lipogenesis and decreased glucose uptake and insulin sensitivity; (iii) induction of hypothalamic LPL activity in mice, which is highly expressed throughout the brain and is associated with enhanced brain lipid sensing, reduction of food intake, and inhibition of glucose production (however, the effects of ANGPTL3 on hypothalamic LPL in humans need more clarification); and (iv) upregulation of ANGPTL4 expression (owing to the plasma FFA increase), which possibly enhances insulin resistance due to the selective inhibition of LPL in white adipose tissue leading to ectopic lipid accumulation and insulin resistance. Future trials will reveal if ANGPTL3 inhibition could be considered an alternative therapeutic target for dyslipidemia and dysglycemia.

Hepatocyte Nuclear Factor 4 alpha (HNF4α) is required for hepatocyte differentiation and regulates expression of genes involved in lipid and carbohydrate metabolism including those that control VLDL secretion and gluconeogenesis. Whereas previous studies have focused on specific genes regulated by HNF4α in metabolism, its overall role in whole body energy utilization has not been studied. In this study, we used indirect calorimetry to determine the effect of hepatocyte-specific HNF4α deletion (HNF4α-KO) in mice on whole body energy expenditure (EE) and substrate utilization in fed, fasted, and high fat diet (HFD) conditions. HNF4α-KO had reduced resting EE during fed conditions and higher rates of carbohydrate oxidation with fasting. HNF4α-KO mice exhibited decreased body mass caused by fat mass depletion despite no change in energy intake and evidence of positive energy balance. HNF4α-KO mice were able to upregulate lipid oxidation during HFD suggesting that their metabolic flexibility was intact. However, only hepatocyte specific HNF4α-KO mice exhibited significant reduction in basal metabolic rate and spontaneous activity during HFD. Consistent with previous studies, hepatic gene expression in HNF4α-KO supports decreased gluconeogenesis and decreased VLDL export and hepatic β-oxidation in HNF4α-KO livers across all feeding conditions. Together, our data suggest deletion of hepatic HNF4α increases dependence on dietary carbohydrates and endogenous lipids for energy during fed and fasted conditions by inhibiting hepatic gluconeogenesis, hepatic lipid export, and intestinal lipid absorption resulting in decreased whole body energy expenditure. These data clarify the role of hepatic HNF4α on systemic metabolism and energy homeostasis.

Newborns with intrauterine growth-restriction are at increased risk of mortality and life-long comorbidities. Insulin-like growth factor-II (IGF2) deficiency in humans, as well as in mice, leads to intrauterine growth restriction and decreased neonatal glycogen stores. The present study aims to further characterize the metabolic and transcriptional consequences of Igf2 deficiency in the newborn. We found that, despite being born significantly smaller than their wild-type ( Igf2+/+) littermates, brain size was preserved in Igf2 knockout ( Igf2−/−), consistent with nutritional deficiency. Histological and triglyceride analyses of newborn livers revealed that Igf2−/−mice are born with hepatic steatosis. Gene expression analysis in Igf2−/−newborn livers showed an alteration of genes known to be dysregulated in chronic caloric restriction, including the most upregulated gene, serine dehydratase. Multiple genes connected with lipid metabolism and/or hepatic steatosis were also upregulated. Ingenuity Pathway Analysis confirmed that the biological functions most altered in livers of Igf2−/−newborns are related to lipid metabolism, with the top upstream regulator predicted to be the peroxisome proliferator-activated receptor alpha, a master regulator of hepatic lipid and carbohydrate homeostasis. Together, our data indicate that Igf2 deficiency leads to a newborn phenotype strongly reminiscent of nutritional deficiency, including growth retardation, increased brain/body weight ratio, hepatic steatosis, and characteristic changes in hepatic gene expression. We propose that in addition to its growth factor proliferating functions, Igf2 may also regulate growth by altering the expression of genes that control nutrient metabolism in the newborn.

Clinical trials and meta-analyses have shown that statins can dose dependently increase the incidence of new-onset diabetes mellitus (DM) especially in patients with underlying abnormalities of carbohydrate homeostasis. Mendelian randomization studies support these findings since genetic variants in the gene encoding the target of statins, the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase, are associated with increased incidence of new-onset DM, suggesting that the so-called diabetogenic effect of statins is an "on-target effect" possibly related to their main mechanism of action, that is the increased low-density lipoprotein (LDL) receptor expression. Additionally, Mendelian randomization studies have shown that genetic variants as proxies of other drugs that increase LDL receptor expression (ezetimibe and proprotein convertase subtilisin/kexin type 9 [PCSK9] inhibitors) also increase the risk of new-onset DM. This concept is supported by the fact of decreased DM prevalence in patients with familial hypercholesterolemia who have decreased LDL receptor expression. In contrast, hypolipidemic drugs, such as the cholesteryl ester transfer protein inhibitors, that decrease LDL cholesterol without directly interfering with the LDL receptor expression do not seem to detrimentally affect carbohydrate homeostasis. However, the clinical trials of ezetimibe and PCSK9 inhibitors have not shown an increased DM risk, possibly suggesting that other potential non-well-defined "off-target effects" of hypolipidemic drugs may affect carbohydrate homeostasis. Thus, the long-term effect of hypolipidemic drugs on DM risk depends not only on their final mechanism of hypolipidemic action but also on other "on-target" and "off-target" effects of these drugs.

SummaryFibroblast growth factor 15 (FGF15) has been proposed as a postprandial hormone that signals from intestine to liver to regulate bile acid and carbohydrate homeostasis. However, detecting FGF15 in blood using conventional techniques has proven difficult. Here, we describe a stable isotope standards and capture by anti-peptide antibodies (SISCAPA) assay that combines immuno-enrichment with selected reaction monitoring (SRM) mass spectrometry to overcome this issue. Using this assay, we show that FGF15 circulates in plasma in an FXR and circadian rhythm-dependent manner at concentrations that activate its receptor. Consistent with the proposed endocrine role for FGF15 in liver, mice lacking hepatocyte expression of the obligate FGF15 co-receptor, β-Klotho, have increased bile acid synthesis and reduced glycogen storage despite having supraphysiological plasma FGF15 concentrations. Collectively, these data demonstrate that FGF15 functions as a hormone and highlight the utility of SISCAPA-SRM as a sensitive assay for detecting low-abundance proteins in plasma.

Purpose Previous studies have shown that several components of the metabolic syndrome, such as hypertension, obesity or imbalanced lipid and carbohydrate homeostasis, are associated with the sympathetic nervous system overactivity. Therefore, the inhibition of the adrenergic nervous system seems to be a reasonable and appropriate therapeutic approach for the treatment of metabolic disturbances. It has been suggested that non-selective adrenoceptor antagonists could be particularly beneficial, since $\alpha$1-adrenoceptor antagonists can improve disrupted lipid and carbohydrate profiles, while the inhibition of the $\alpha$2-adrenoceptor may contribute to body weight reduction. The aim of the present study was to investigate the metabolic benefits deriving from administration of a non-selective $\alpha$-adrenoceptor antagonist from the group of pyrrolidin-2-one derivatives. The aim of the present study was to investigate the potential metabolic benefits deriving from chronic administration o a non-selective $\alpha$-adrenoceptor antagonist, from the group of pyrrolidin-2-one derivatives. Methods The $\alpha$1- and $\alpha$2-adrenoreceptor affinities of the tested compound-1-(3-(4-(o-tolyl)piperazin-1-yl)propyl) pyrrolidin-2-one had been investigated previously by means of the radioligand binding assay. In the present study, we extended the pharmacological profile characteristics of the selected molecule by additional intrinistic activity assays. Next, we investigated the influence of the tested compound on body weight, hyperglycemia, hypertriglyceridemia, blood pressure in the animal model of obesity induced by a highfat diet, and additionally we measured the spontaneous activity and body temperature. Results The intrinistic activity studies revealed that the tested compound is a potent, non-selective antagonist of $\alpha$1B and $\alpha$2A-adrenoceptors. After the chronic administration of the tested compound, we observed reduced level of triglycerides and glucose in the rat plasma. Interestingly, the tested did not reduce the body weight and did not influence the blood pressure in normotensive animals. Additionally, the administration of the tested compound did not change the animals' spontaneous activity and body temperature. Conclusion Non-selective $\alpha$-adrenoceptor antagonist seems to carry potential benefits in the improvement of the reduction of elevated glucose and triglyceride level. The lack of influence on blood pressure suggests that compounds with such a pharmacological profile may be particulary beneficial for the patients with disturbed lipid and carbohydrate profile, who do not suffer from hypertension. These results are particulary valuable, since currently there are no safe $\alpha$2A-adrenoceptor antagonist drugs available in clinical use with the ability to modulate hyperglycemia that would not affect blood pressure.

The sessile lifestyle of higher plants is accompanied by their remarkable ability to tolerate unfavorable environmental conditions. This is because, during evolution, plants developed a sophisticated repertoire of molecular and metabolic reactions to cope with changing biotic and abiotic challenges. In particular, the abiotic factors light intensity and ambient temperature are characterized by altering their amplitude within comparably short periods of time and are causative for onset of dynamic plant responses. These rapid responses in plants are also classified as 'acclimation reactions' which differ, due to their reversibility and duration, from non-reversible 'adaptation reactions'. In this review, we demonstrate the remarkable importance of stress-induced changes in carbohydrate homeostasis of plants exposed to high light or low temperatures. These changes represent a co-ordinated process comprising modifications of (i) the concentrations of selected sugars; (ii) starch turnover; (iii) intracellular sugar compartmentation; and (iv) corresponding gene expression patterns. The critical importance of these individual processes has been underlined in the recent past by the analyses of a large number of mutant plants. The outcome of these analyses raised our understanding of acclimation processes in plants per se but might even become instrumental to develop new concepts for directed breeding approaches with the aim to increase abiotic stress tolerance of crop species, which in most cases have high stress sensitivity. The latter direction of plant research is of special importance since abiotic stress stimuli strongly impact on crop productivity and are expected to become even more pronounced because of human activities which alter environmental conditions rapidly.

Cholesteryl ester transfer protein (CETP) inhibitors significantly increase serum high-density lipoprotein cholesterol (HDL) cholesterol levels and decrease low-density lipoprotein cholesterol (LDL) cholesterol concentration. However, three drugs of this class failed to show a decrease of cardiovascular events in high-risk patients. A new CETP inhibitor, anacetrapib, substantially increases HDL cholesterol and apolipoprotein (Apo) AI levels with a profound increase of large HDL2 particles, but also pre-β HDL particles, decreases LDL cholesterol levels mainly due to increased catabolism of LDL particles through LDL receptors, decreases lipoprotein a (Lp(a)) levels owing to a decreased Apo (a) production and, finally, decreases modestly triglyceride (TRG) levels due to increased lipolysis and increased receptor-mediated catabolism of TRG-rich particles. Interestingly, anacetrapib may be associated with a beneficial effect on carbohydrate homeostasis. Furthermore, the Randomized EValuation of the Effects of Anacetrapib Through Lipid-modification (REVEAL) trial showed that anacetrapib administration on top of statin treatment significantly reduces cardiovascular events in patients with atherosclerotic vascular disease without any significant increase of adverse events despite its long half-life. Thus, anacetrapib could be useful for the effective management of dyslipidemias in high-risk patients that do not attain their LDL cholesterol target or are statin intolerable, while its role in patients with increased Lp(a) levels remains to be established.

Hypoglycemia in the neonatal period is one of the urgent problems of pediatric endocrinology. The main factors that lead to disruption of carbohydrate homeostasis are generally known, but the issues of neonatal hypoglycemia continue to be actively studied. In the last few years, the effect of low blood glucose on brain neurons has been studied, the issues of glycemia monitoring in the first days of life have been outlined, and strategies for managing newborns with hypoglycemic syndrome are being discussed.Гипогликемии в периоде новорожденности являются одной из актуальных проблем детской эндокринологии. Основные факторы, приводящие к нарушению гомеостаза углеводов, в целом известны, однако вопросы неонатальных гипогликемий продолжают активно изучаться. В последние годы исследуется влияние низкого уровня глюкозы крови на нейроны головного мозга, дискутируются вопросы мониторинга гликемии в первые дни жизни, обсуждается тактика ведения новорожденных с гипогликемическим синдромом.

Statins are the cornerstone of lipid-lowering treatment in patients with or without type 2 diabetes. Prospective randomized clinical trials and meta-analyses have shown that the statin-mediated decrease in plasma low-density lipoprotein cholesterol (LDL-C) is associated with a significant decrease in cardiovascular (CV) morbidity and mortality. Furthermore, high-intensity statin treatment in high-risk individuals is followed by a significantly greater decrease in CV events compared with moderate dose statin treatment. However, the majority of high-risk individuals do not attain the LDL-C targets set by the guidelines even if high-intensity statin therapy is used. This is especially relevant in diabetic patients who need aggressive lipid management to decrease macrovascular complications. To further decrease this residual CV risk associated with suboptimal reduction in LDL-C levels, combination lipid-lowering treatment (eg, statin þ ezetimibe) is an attractive option. Ezetimibe targets the Niemann-Pick C1-like 1 (NPC1L1) protein and thus decreases cholesterol absorption from the gastrointestinal tract leading to a further fall in plasma LDL-C concentration by 20% to 25% when added to ongoing statin therapy. The recently published results of the Improved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT) study showed, for the first time, that the additional ezetimibe-induced decrease in LDL-C levels (compared with simvastatin monotherapy) is associated with a significant further decrease in major CV events in very high-risk patients with acute coronary syndrome. Thus, the IMPROVE-IT trial confirms the LDL-C story. A lower LDL-C concentration is better for the reduction in CV events. These findings also refute any hypothesis that focuses on LDL-C–independent pleiotropic effects of statins. Additionally, a recently published meta-analysis of randomized controlled trials showed that adding ezetimibe to statin therapy not only decreases LDL-C concentration but also reduces CV events (relative risk: 0.92, P 1⁄4 .004). The IMPROVE-IT trial showed that elderly individuals and diabetic patients gain greater benefit from the addition of ezetimibe (Table 1). Interestingly, the addition of ezetimibe to ongoing statin therapy may induce a greater reduction in plasma LDL-C levels in diabetic patients compared with nondiabetic individuals. It is worth mentioning that the incidence of side effects (including cancer) in the IMPROVE-IT trial was not different between the statin and the statin þ ezetimibe combination groups. This finding not only confirms the long-term safety of ezetimibe but also that of very low LDL-C levels. Furthermore, recently published Mendelian randomization studies have also confirmed the benefits of decreased cholesterol absorption, which is associated with reduction in LDL-C concentration, in terms of CV disease. These studies showed that genetic polymorphisms of the NPC1L1 gene, which can be used as a proxy of ezetimibe therapy that targets the NPC1L1 protein, are not only associated with a reduction in LDL-C levels but also with a reduction in CV events (Table 2). Thus, combination therapy of statins with ezetimibe is a reasonable, effective, and safe option to treat diabetic dyslipidemia. Nowadays, fixed-dose combinations of a statin with ezetimibe are currently, or awaiting to be, marketed. The fixed-dose atorvastatin þ ezetimibe combination is especially attractive, since it can substantially increase adherence to statin therapy, while atorvastatin (the most commonly used statin in many countries) has the unique properties of lower renal excretion and fewer interactions with other commonly used drugs compared with simvastatin. Further analysis of the results of the IMPROVE-IT trial will clarify the role of ezetimibe (and of statin þ ezetimibe combination therapy) in carbohydrate homeostasis. Some recently published preliminary data hint that ezetimibe might favorably affect insulin resistance and carbohydrate metabolism, in part due to its ability to stimulate intestinal glucagon-like peptide 1 secretion via the mitogen-activated protein/extracellular signal-regulated kinase kinase/extracellular signal-regulated kinase signaling pathway. It is worth mentioning that ezetimibe can also exhibit pleiotropic effects

Accessions of Arabidopsis thaliana originating from climatically different habitats show different levels of cold acclimation when exposed to low temperatures. The central carbohydrate metabolism plays a crucial role during this acclimation. Subcellular distribution of carbohydrates over the compartments cytosol, vacuole and plastids, and putative interactions of the compartments, are analyzed in three differentially cold-tolerant accessions of Arabidopsis thaliana, originating from the Iberian Peninsula (C24), Russia (Rschew) and Scandinavia (Tenela), respectively. Subcellular carbohydrate concentrations were determined by applying the nonaqueous fractionation technique. Mathematical modeling and steady-state simulation was used to analyse the metabolic homeostasis during cold exposure. In all accessions, the initial response to cold exposure was a significant increase of plastidial and cytosolic sucrose concentrations. Raffinose accumulated in all cellular compartments of cold-tolerant accessions with a delay of 3 d, indicating that raffinose accumulation is a long-term component of cold acclimation. Minimal rates of metabolite transport permitting steady-state simulations of metabolite concentrations correlated with cold tolerance, indicating an important role of subcellular re-distribution of metabolites during cold acclimation. A highly regulated interplay of enzymatic reactions and intracellular transport processes appears to be a prerequisite for maintaining carbohydrate homeostasis during cold exposure and allowing cold acclimation in Arabidopsis thaliana.

Dyslipidemia is a frequent component of the metabolic disorder of diabetic patients contributing to organ damage. Herein, in low-density lipoprotein receptor–deficient hyperlipidemic and streptozotozin-induced diabetic mice, hyperglycemia and hyperlipidemia acted reciprocally, accentuating renal injury and altering renal function. In hyperglycemic-hyperlipidemic kidneys, the accumulation of Tip47-positive lipid droplets in glomeruli, tubular epithelia, and macrophages was accompanied by the concomitant presence of the oxidative stress markers xanthine oxidoreductase and nitrotyrosine, findings that could also be evidenced in renal biopsy samples of diabetic patients. As liver X receptors (LXRα,β) regulate genes linked to lipid and carbohydrate homeostasis and inhibit inflammatory gene expression in macrophages, the effects of systemic and macrophage-specific LXR activation were analyzed on renal damage in hyperlipidemic-hyperglycemic mice. LXR stimulation by GW3965 up-regulated genes involved in cholesterol efflux and down-regulated proinflammatory/profibrotic cytokines, inhibiting the pathomorphology of diabetic nephropathy, renal lipid accumulation, and improving renal function. Xanthine oxidoreductase and nitrotyrosine levels were reduced. In macrophages, GW3965 or LXRα overexpression significantly suppressed glycated or acetylated low-density lipoprotein–induced cytokines and reactive oxygen species. Specifically, in mice, transgenic expression of LXRα in macrophages significantly ameliorated hyperlipidemic-hyperglycemic nephropathy. The results demonstrate the presence of lipid droplet–induced oxidative mechanisms and the pathophysiologic role of macrophages in diabetic kidneys and indicate the potent regulatory role of LXRs in preventing renal damage in diabetes.

Diabetes mellitus (DM) is a serious and growing worldwide health problem and is associated with se- vere acute and chronic complications that negatively influence both quality of life and survival of affected individuals. It is a heterogeneous deregulation of car- bohydrate metabolism. The liver is a central regulator of carbohydrate homeostasis and releases glucose according to metabolic demands. In the last years, the liver injury has been recognized as a major complica- tion of DM. In fact, evidence suggests that in diabetic patients, the mortality rate due to liver cirrhosis is even higher than that due to cardiovascular disease and it has been suggested that there is a two-fold in- creased risk of liver disease in diabetic patients. Among the different types of diabetes, we analyze type 1 dia- betes mellitus as a chronic disorder and an inflam- matory process, which is also associated with in- creased risk of chronic liver injury. Animal models have contributed extensively to the study of diabetes, and it is well established that administration of a unique dose of streptozotocin (STZ) induces insulin- dependent type 1 diabetes mellitus. We analyzed the contribution of Tumor Necrosis Factor alpha (TNF-α) intracellular pathway and oxidative stress in the de- velopment of apoptosis in the liver of streptozotocin- induced diabetic animals. In this review, we describe the role of upstream mediators of the interaction be- tween TNF-α and its receptor, TNF-R1, by assessing the ability of the in vivo treatment with etanercept (TNF-α blocking antibody) to protect against TNF-α- induced apoptosis. Also, we studied the role of iNOS- induction in the TNF-α-induced liver apoptosis by type 1 diabetes, by treatment of diabetic rats with aminoguanidine (selective iNOS inhibitor), which blocked the induction of apoptosis. Interestingly, iNOS inhibition significantly reduced TNF-α levels, evidencing an interaction between TNF-α and iNOS activity. On the other hand, we found that the ad- ministration of antioxidants/hydroxyl radical scaven- gers (Tempol and Desferal) prevented oxidative stress by reducing the effects of hydroxyl radical production and both lipid peroxidation (LPO) levels and apop- tosis. Taken together, our studies support that, at least in part, the hydroxyl radical acts as a reactive inter- mediate, which leads to liver apoptosis in a model of STZ-mediated hyperglycemia. Conclusion and Future: The relevance of the present review is to provide fur- ther knowledge about the mechanisms which may contribute to the disease process in the liver during the course of an inflammatory process as it is type 1 diabetes. Regulation of hepatic TNF-α levels and oxi- dative stress in the diabetic state could be of thera- peutic relevance for the improvement or delay of the hepatic complications linked to chronic hyperglycemia. Fil: Frances, Daniel Eleazar Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); Argentina Fil: Ingaramo, Paola Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); Argentina Fil: Ronco, Maria Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); Argentina Fil: Carnovale, Cristina Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); Argentina

Background Most recently, a novel myokine, named irisin, was identified in human that expressed by skeletal muscle after exercise. Irisin increases energy expenditure by turning white adipose tissue into brown adipose tissue. Thus improves carbohydrate homeostasis in humans. Irisin is considered as a potential biomarker for obesity and metabolic syndrome. In recent years, numerous studies have been conducted about irisin with adults, although number of studies with newborns is limited. Objective To evaluate cord blood irisin level with small gestational age (SGA) and appropriate gestational age (AGA) in term newborns. Methods A cross-sectional study of 34 AGA and 34 SGA term newborns who were born in (1–30) December 2015 in Fatih University Hospital. Estimated fetal weight were calculated using the Hadlock formula by gynecologists to pregnant women in second trimester. All the babies were classified at birth as SGA or AGA. SGA was defined according to the Lubchenco scale for gender and gestational age. We collected umbilical cord blood at the time of delivery. Cord blood irisin levels were measured using commercial enzyme-linked immunosorbent assays in our hospital laboratory. Results Cord blood irisin levels were significantly lower in SGA group [median 30 (25 ± 8) ng/ml] than in AGA group [median 40 (39 ± 13) ng/ml, p 0.05). Mothers with gestational diabetes, hypertension, asthma, chronic disease, use of drug or a history of smoking exposure were excluded from the study. When the study data were evaluated, Yates Continuity Correction and Fisher’s exact tests were used in descriptive statistical methods and for comparison of qualitative data. Conclusion Our results support the idea that irisin have a physiologic role in neonates. Low level of irisin is associated with the impaired carbohydrate metabolism in term infants with SGA. However, further studies with larger series are warranted to confirm this.

Introduction The causal role of sympathetic nervous system in the development of metabolic disorders has not been clearly defined. The aim of the study was to determine if a chronic increase of the sympathetic nervous activity can induce and/or accelerate the development of glucose metabolism disorders. For that purpose, we used a transgenic mouse model, in which the gene encoding for the reuptake norepinephrine transporter (NET) has been deleted; these animals display increased urinary catecholamine levels. Methods Carbohydrate homeostasis (intraperitoneal glucose tolerance test, IPGTT, insulin tolerance test, ITT, insulin rates) was studied in heterozygous NET knockout mice (±) or wild-type mice (+/+) at 10, 20 and 25 weeks old. Mice were then fed either with normal chow or 30% w/v fructose in drinking water; glucose metabolism was assessed again after 15 weeks of such diet. Results Heterozygous mice displayed glucose intolerance already at 10 weeks old (area under the curve of the IPGTT (AUC; %) = 24859 vs 18016, p=0.004); similar results were obtained at 25 weeks old, i.e, just before starting the fructose diet: AUC = 24524 vs 20573, p=0.005 for ± and +/+ mice respectively. Moreover sensibility to insulin seemed to be diminished in ± mice compared to +/+ mice (insulin rate = 1.12 vs 0.86 μg/L and HOMAIR= 11.1 vs 8.4). Heterozygous animals were also much more sensitive to high fructose, since a 20% increase in the AUC of the IPGTT was obtained at the end of the high fructose diet, compared to the 2% increase in +/+ mice. This was associated with a decrease of insulin sensibility (HOMA-IR of ± mice = 11.1 vs 18.1, p=0.01, before and after fructose diet respectively). Conclusion Our data show that constitutive chronic sympathetic hyperactivity can induce the early development of carbohydrate metabolism disorders. Moreover, it seems to represent a major factor of susceptibility to diet-induced metabolic dysfunction. The author hereby declares no conflict of interest

Central carbohydrate metabolism of Arabidopsis thaliana is known to play a crucial role during cold acclimation and the acquisition of freezing tolerance. During cold exposure, many carbohydrates accumulate and a new metabolic homeostasis evolves. In the present study, we analyse the diurnal dynamics of carbohydrate homeostasis before and after cold exposure in three natural accessions showing distinct cold acclimation capacity. Diurnal dynamics of soluble carbohydrates were found to be significantly different in cold-sensitive and cold-tolerant accessions. Although experimentally determined maximum turnover rates for sucrose phosphate synthase in cold-acclimated leaves were higher for cold-tolerant accessions, model simulations of diurnal carbohydrate dynamics revealed similar fluxes. This implied a significantly higher capacity for sucrose synthesis in cold-tolerant than cold-sensitive accessions. Based on this implication resulting from mathematical model simulation, a critical temperature for sucrose synthesis was calculated using the Arrhenius equation and experimentally validated in the cold-sensitive accession C24. At the critical temperature suggested by model simulation, an imbalance in photosynthetic carbon fixation ultimately resulting in oxidative stress was observed. It is therefore concluded that metabolic capacities at least in part determine the ability of accessions of Arabidopsis thaliana to cope with changes in environmental conditions.

Insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-3 (IGFBP-3) are involved in cell replication, proliferation, differentiation, protein synthesis, carbohydrate homeostasis and bone metabolism. Circulating IGF-I and IGFBP-3 concentrations predict anthropometric traits and risk of cancer and cardiovascular disease. In a genome-wide association study of 10 280 middle-aged and older men and women from four community-based cohort studies, we confirmed a known association of single nucleotide polymorphisms in the IGFBP3 gene region on chromosome 7p12.3 with IGFBP-3 concentrations using a significance threshold of P < 5 × 10(-8) (P = 3.3 × 10(-101)). Furthermore, the same IGFBP3 gene locus (e.g. rs11977526) that was associated with IGFBP-3 concentrations was also associated with the opposite direction of effect, with IGF-I concentration after adjustment for IGFBP-3 concentration (P = 1.9 × 10(-26)). A novel and independent locus on chromosome 7p12.3 (rs700752) had genome-wide significant associations with higher IGFBP-3 (P = 4.4 × 10(-21)) and higher IGF-I (P = 4.9 × 10(-9)) concentrations; when the two measurements were adjusted for one another, the IGF-I association was attenuated but the IGFBP-3 association was not. Two additional loci demonstrated genome-wide significant associations with IGFBP-3 concentration (rs1065656, chromosome 16p13.3, P = 1.2 × 10(-11), IGFALS, a confirmatory finding; and rs4234798, chromosome 4p16.1, P = 4.5 × 10(-10), SORCS2, a novel finding). Together, the four genome-wide significant loci explained 6.5% of the population variation in IGFBP-3 concentration. Furthermore, we observed a borderline statistically significant association between IGF-I concentration and FOXO3 (rs2153960, chromosome 6q21, P = 5.1 × 10(-7)), a locus associated with longevity. These genetic loci deserve further investigation to elucidate the biological basis for the observed associations and clarify their possible role in IGF-mediated regulation of cell growth and metabolism.

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine produced by many cells and tissues including pancreatic β-cells, liver, skeletal muscle, and adipocytes. This study investigates the potential role of MIF in carbohydrate homeostasis in a physiological setting outside of severe inflammation, utilizing Mif knockout (MIF−/−) mice. Compared with wild-type (WT) mice, MIF−/− mice had a lower body weight, from birth until 4 months of age, but subsequently gained weight faster, resulting in a higher body weight at 12 months of age. The lower weight in young mice was related to a higher energy expenditure, and the higher weight in older mice was related to an increased food intake and a higher fat mass. Fasting blood insulin level was higher in MIF−/− mice compared with WT mice at any age. After i.p. glucose injection, the elevation of blood insulin level was higher in MIF−/− mice compared with WT mice, at 2 months of age, but was lower in 12-month-old MIF−/− mice. As a result, the glucose clearance during intraperitoneal glucose tolerance tests was higher in MIF−/− mice compared with WT mice until 4 months of age, and was lower in 12-month-old MIF−/− mice. Insulin resistance was estimated (euglycemic–hyperinsulinemic clamp tests), and the phosphorylation activity of AKT was similar in MIF−/− mice and WT mice. In conclusion, this mouse model provides evidence for the role of MIF in the control of glucose homeostasis.

ATIENTS undergoing major surgery encounter stereotypical alterations in carbohydrate and protein metabolism often referred to as the catabolic response. Characteristic features of impaired carbohydrate homeostasis are increased production of glucose combined with decreased glucose utilization resulting in hyperglycemia. The magnitude of hyperglycemia depends on the severity of surgical tissue trauma. In fasting non-diabetic patients undergoing elective intra-abdominal operations, blood glucose levels increase to 7–10 mmol·L –1 . During cardiac surgery, blood glucose values frequently exceed 15 mmol·L –1 in non-diabetic patients and 20 mmol·L –1 in diabetic subjects. Protein catabolism is characterized by a net loss of body protein. In metabolically healthy patients cumulative nitrogen losses, after elective abdominal operations, range between 40 and 80 g, equivalent to 1.2 to 2.4 kg lean tissue. Postoperative protein loss in patients with type 2 diabetes is 50% greater than in their non-diabetic counterparts. 1 Much of the catabolic profile can be explained by specific neuroendocrine changes, including increased circulating concentrations of cortisol, glucagon, and catecholamines. These hormones exert catabolic effects, either directly or indirectly, by inhibiting insulin secretion and/or counteracting its peripheral action leading to the impairment of tissue insulin sensitivity. The extent of insulin resistance depends on the intensity of trauma, suggesting that insulin resistance is a marker of surgical stress. Clinical significance of the catabolic response to surgery Evidence is mounting that even moderate increases in blood glucose are associated with adverse outcomes. Patients with fasting glucose levels > 7 mmol·L –1 or random blood glucose levels > 11.1 mmol·L –1 on general surgical wards showed an 18-fold increase in in-hospital mortality, a longer length of stay, and a greater risk of infection. 2 In critically ill patients, mortality was directly correlated with increasing glucose levels above 5 mmol·L –1 . 3 In patients undergoing cardiovascular procedures, hyperglycemia was associated with increased mortality and organ dysfunction. 4 Furthermore, detrimental effects of acute hyperglycemia were documented in patients with cerebrovascular disease, myocardial ischemia, and trauma. Erosion of lean tissue protein delays wound healing, compromises immune function, and diminishes muscle strength after surgery. The resulting muscle weakness prolongs mechanical ventilation, inhibits effective coughing, and impedes mobilization. The length of time for return of normal physiologic function after discharge from the hospital is related to the extent of loss of lean body mass during hospitalization. 5

Oxidative stress plays a major role in the pathogenesis of a variety of acute and chronic diseases. Measurement of the oxidative stress-related end products may be performed, e.g. that of structural isomers of the physiological para-tyrosine, namely meta- and ortho-tyrosine, that are oxidized derivatives of phenylalanine. Recent data suggest that in sepsis, serum level of meta-tyrosine increases, which peaks on the 2(nd) and 3(rd) days (p

Quantifying glucose production and glycogen flux, especially during a glucose challenge, should inform on the underlying nature of glucose intolerance and therein support therapeutic programs aimed...

The glucocorticoid receptor (GR) is a crucial target gene for glucocorticoid-induced insulin resistance and hepatic gluconeogenesis linked to the development of type 2 diabetes. The liver X receptors (LXRs) are nuclear receptors that play an important role in the regulation of the metabolic gene linked to carbohydrate homeostasis. To assess the tissuespecificinteractionofLXRwithGRinthedevelopmentoftype 2 diabetes, we examined the possible effect of LXR agonist T0901317 on GR gene expression in vivo and in vitro in hepatocytes from db/db mice (a model of type 2 diabetes). Chronic ligand activation of LXR by a synthetic LXR T0901317 markedly decreased the expression of both GR mRNA and its protein in liver and improved the phenotype of type 2 diabetes in obese db/db mice. Suppression of hepatic GR expression was correlatedwithreducedlevelsofglucoseandcorrespondedto the inhibition of phosphoenolpyruvate carboxykinase mRNA and 11-hydroxysteroid dehydrogenase type 1-mediated synthesis of active corticosterone from inactive 11-dehydrocorticosterone in liver. Treatment of db/db mouse primary hepatocytes with T0901317 resulted in dramatic suppression of GR mRNA and required ongoing protein synthesis. Addition of T0901317 to primary hepatocytes also suppressed the expression of both 11-hydroxysteroid dehydrogenase type 1 and phosphoenolpyruvate carboxykinase. These findings suggest thatsomeofantidiabeticactionsofLXRagonistT0901317may be mediated, at least in part, through the suppression of hepatic GR gene expression. (Endocrinology 147: 5061–5068, 2006)

The Enteroendocrine cells form the largest endocrine system in the body. They secrete multiple regulatory molecules which control physiological and homeostatic functions particularly postprandial regulation of glucose and GIT motility (Sternini et al. 2008).In Diabetic setting, it is speculated that enteroendocrine cells which secrete hormones involved in carbohydrate metabolism will undergo changes aimed at maintaining carbohydrate homeostasis (Stephanie et al. 2009).To determine how enteroendocrine cells respond to diabetes and their likely role in diabetic complications, Sixty albino Wister rats (male=30 and female =30), weighing between 200-300g were divided into five experimental groups (n=10) per group and a control (n=10) . Diabetes mellitus was induced with a single intraperitoneal dose of 65mg per kg of streptozotocin. Blood was sample from tail vein 30 minutes after the application of EMLAR cream (2.5% lignocaine and 2.5% prilocaine) for glucose test and only those with blood glucose within the ...

A influência da glândula pineal sobre o metabolismo de carboidratos vem sendo investigada há décadas. Entretanto, resultados contraditórios não esclarecem, até o momento, o verdadeiro papel da melatonina sobre a homeostasia dos carboidratos. Através de estudos recentes, contribuímos de maneira ineqüívoca para a caracterização do papel da glândula pineal como moduladora do metabolismo de carboidratos. Além disso, à luz dos conhecimentos atuais, demonstramos quais passos do mecanismo de ação da insulina estão envolvidos nessa modulação. Nossos estudos revelaram que a pinealectomia promove um quadro de resistência à insulina, sem obesidade. A captação máxima de 2-deoxi-glicose, estimulada por insulina, em adipócitos isolados está diminuída, sem entretanto modificar a capacidade da insulina ligar-se ao seu receptor e estimular a fosforilação dos substratos intracelulares representados pela pp 185. Por outro lado, em vários tecidos sensíveis à insulina, observou-se uma diminuição no conteúdo da proteína transportadora de glicose GLUT4, mas diminuição no mRNA do GLUT4 apenas em alguns desses tecidos, sugerindo uma regulação tecido-específica. Adicionalmente, foi demonstrado que a regulação da glândula pineal sobre o metabolismo de carboidratos é mediado pela melatonina: o hormônio aumentou a sensibilidade à insulina de adipócitos isolados e o tratamento de reposição com melatonina restaurou o conteúdo de GLUT4 no tecido adiposo branco. Em síntese, os estudos aqui relatados evidenciam um importante papel da glândula pineal na modulação da homeostasia de carboidratos. Essa regulação é dependente da melatonina e pode ser resumida, até o presente momento, como um aumento da sensibilidade tecidual à insulina, que envolve alterações na expressão gênica do GLUT4. For decades, the influence of the pineal gland on carbohydrate metabolism has been investigated. However, contradictory results have not yet elucidated the role played by melatonin in carbohydrate homeostasis. In our recent studies, we have contributed to characterize the role of the pineal gland as a modulator of carbohydrate metabolism. In addition, based on present-day knowledge, we have demonstrated the steps of insulin action mechanism involved in this modulation. Our studies reveal that pinealectomy causes a condition of obesity-free insulin resistance. The maximum uptake of 2-deoxi-glucose prompted by insulin in isolated adipocytes is diminished, without however changing the insulin capacity to bind to its receptor, and to stimulate the phosphorilation of intracellular substrates represented by pp 185. Conversely, in several insulin-sensitive tissues, our studies detected a decrease in the amount of glucose transporter protein GLUT4, and a decrease in GLUT4 mRNA in only some of these tissues, suggesting a tissue-specific regulation. Additionally, it was demonstrated that the pineal gland regulation influences carbohydrate metabolism through melatonin, by our demonstration that the hormone increased insulin sensitivity of isolated adipocytes, and that melatonin replacement therapy restored the amount of GLUT4 in white adipose tissue. In summary, the studies reported here evidence an important role played by the pineal gland in the modulation of carbohydrate homeostasis. This regulation seems to be melatonin-dependent and can be described, so far, as an increase in tissue sensitivity to insulin, which involves changes in GLUT4 gene expression.

It has been shown that seed development is regulated by a network of transcription factors in Arabidopsis including LEC1 (LEAFY COTYLEDON1), L1L (LEC1-like) and the B3 domain factors LEC2, FUS3 (FUSCA3) and ABI3 (ABA-INSENSITIVE3); however, molecular and genetic regulation of seed development in cereals is poorly understood. To understand seed development and seed germination in cereals, a large-scale screen was performed using our T-DNA mutant population, and a mutant germination-defective1 (gd1) was identified. In addition to the severe germination defect, the gd1 mutant also shows a dwarf phenotype and abnormal flower development. Molecular and biochemical analyses revealed that GD1 encodes a B3 domain-containing transcription factor with repression activity. Consistent with the dwarf phenotype of gd1, expression of the gibberelic acid (GA) inactivation gene OsGA2ox3 is increased dramatically, accompanied by reduced expression of GA biosynthetic genes including OsGA20ox1, OsGA20ox2 and OsGA3ox2 in gd1, resulting in a decreased endogenous GA₄ level. Exogenous application of GA not only induced GD1 expression, but also partially rescued the dwarf phenotype of gd1. Furthermore, GD1 binds to the promoter of OsLFL1, a LEC2/FUS3-like gene of rice, via an RY element, leading to significant up-regulation of OsLFL1 and a large subset of seed maturation genes in the gd1 mutant. Plants over-expressing OsLFL1 partly mimic the gd1 mutant. In addition, expression of GD1 was induced under sugar treatment, and the contents of starch and soluble sugar are altered in the gd1 mutant. These data indicate that GD1 participates directly or indirectly in regulating GA and carbohydrate homeostasis, and further regulates rice seed germination and seedling development.

Glucose and other carbohydrates are transported into cells using members of a family of integral membrane glucose transporter (GLUT) molecules. To date 14 members of this family, also called the solute carrier 2A proteins have been identified which are divided on the basis of transport characteristics and sequence similarities into several families (Classes 1 to 3). The expression of these different receptor subtypes varies between different species, tissues and cellular subtypes and each has differential sensitivities to stimuli such as insulin. The liver is a contributor to metabolic carbohydrate homeostasis and is a major site for synthesis, storage and redistribution of carbohydrates. Situations in which the balance of glucose homeostasis is upset such as diabetes or the metabolic syndrome can lead metabolic disturbances that drive chronic organ damage and failure, confirming the importance of understanding the molecular regulation of hepatic glucose homeostasis. There is a considerable literature describing the expression and function of receptors that regulate glucose uptake and release by hepatocytes, the most import cells in glucose regulation and glycogen storage. However there is less appreciation of the roles of GLUTs expressed by non parenchymal cell types within the liver, all of which require carbohydrate to function. A better understanding of the detailed cellular distribution of GLUTs in human liver tissue may shed light on mechanisms underlying disease pathogenesis. This review summarises the available literature on hepatocellular expression of GLUTs in health and disease and highlights areas where further investigation is required.

Hepatic peroxisomes are essential for lipid conversions that include the formation of mature conjugated bile acids, the degradation of branched chain fatty acids, and the synthesis of docosahexaenoic acid. Through unresolved mechanisms, deletion of functional peroxisomes from mouse hepatocytes (L-Pex5(-/-) mice) causes severe structural and functional abnormalities at the inner mitochondrial membrane. We now demonstrate that the peroxisomal and mitochondrial anomalies trigger energy deficits, as shown by increased AMP/ATP and decreased NAD(+)/NADH ratios. This causes suppression of gluconeogenesis and glycogen synthesis and up-regulation of glycolysis. As a consequence, L-Pex5(-/-) mice combust more carbohydrates resulting in lower body weights despite increased food intake. The perturbation of carbohydrate metabolism does not require a long term adaptation to the absence of functional peroxisomes as similar metabolic changes were also rapidly induced by acute elimination of Pex5 via adenoviral administration of Cre. Despite its marked activation, peroxisome proliferator-activated receptor α (PPARα) was not causally involved in these metabolic perturbations, because all abnormalities still manifested when peroxisomes were eliminated in a peroxisome proliferator-activated receptor α null background. Instead, AMP-activated kinase activation was responsible for the down-regulation of glycogen synthesis and induction of glycolysis. Remarkably, PGC-1α was suppressed despite AMP-activated kinase activation, a paradigm not previously reported, and they jointly contributed to impaired gluconeogenesis. In conclusion, lack of functional peroxisomes from hepatocytes results in marked disturbances of carbohydrate homeostasis, which are consistent with adaptations to an energy deficit. Because this is primarily due to impaired mitochondrial ATP production, these L-Pex5-deficient livers can also be considered as a model for secondary mitochondrial hepatopathies.

Adverse effects highlighted in experimental studies of the industrial chemical bisphenol A (BPA) have centered on reproductive targets, but recent research suggests metabolism also may be affected. BPA is widely present in the environment, as are its halogenated derivatives. A new study investigates the structure and function of these halogenated compounds and shows they could potentially disrupt energy balance (i.e., lipid and carbohydrate homeostasis) in humans and wildlife [EHP 119(9):1227–1232; Riu et al.]. Halogenated BPA derivatives are used as flame retardants, with tetrabromobisphenol A (TBBPA) and tetrachlorobisphenol A (TCBPA) as parent compounds. Previous studies have shown that BPA, TBBPA, and TCBPA have estrogenic activity and that BPA can alter adipogenesis (fat cell formation) in rats. Peroxisome proliferator-activated receptor γ (PPARγ) plays a key role in adipogenesis, and interference with this receptor can contribute to type 2 diabetes and obesity. Cell lines were used to test the ability of BPA, TBBPA, TCBPA, and other halogenated BPA derivatives to activate human estrogen receptors (ERα and ERβ) and human PPARs (PPARα, PPARδ, and PPARγ). The compounds also were applied to undifferentiated fat cells to test their effects on adipogenesis and the genes involved in this process. Competitive binding assays were conducted to further characterize PPARγ activation in both reporter cell lines and undifferentiated fat cells, and crystals of PPARγ bound to TBBPA and TCBPA were purified to study how the chemicals bound and activated the receptor. Another set of experiments used Xenopus and zebrafish PPARγ to test the response to BPA compounds in other species. TCBPA and lower brominated BPAs such as monoBBPA and diBBPA partially activated both ER subtypes, whereas TBBPA had little effect on either. Both TBBPA and TCBPA were able to partially activate PPARγ and promote fat cell differentiation as well as disrupt PPARγ activity in all species studied. Structural examination of the area where compounds are bound to the PPARγ receptor yielded evidence that TBBPA, TCBPA, and other halogenated BPA derivatives partially activate this receptor. What does all this mean? Essentially, the findings support the hypothesis that environmental contaminants may contribute to the disruption of energy balance in humans and wildlife. It also suggests that halogenated derivatives of BPA used as flame retardants, which have not been extensively studied to date, may contribute to obesity. The main active form of PPARγ is the retinoid X receptor (RXR)/PPARγ heterodimer. According to the authors, environmental exposure to BPA compounds alongside other endocrine disruptors with similar RXR and/or PPARγ activity sets the stage for additive and synergistic effects, potentially leading to increased risk of metabolic disease.

Phenolic metabolites that contain salicylic acid (SA)-like moieties are major non-structural constituents in Populus leaves, shoots and roots. These so-called phenolic glycosides (PGs) are taxonomically limited to the Salicaceae, where they are known to mitigate insect and animal herbivory. SA itself is an important signaling molecule in plant defense and abiotic stress responses, and is derived from the isochorismate or phenylpropanoid pathways, depending on the species [1,2]. Hyper-accumulation of SA reduces growth in Arabidopsis[3], while high levels of PG have been associated with reduced growth in Populus[4]. Although the common PGs, salicin, salicortin, and their derivatives contain a salicyl moiety, a direct metabolic relationship between PG and SA in Populus has not been shown. We have therefore been using stable isotope tracers, cell culture feeding, functional genomics and transgenic perturbation to probe the relationship between SA, PG and growth in Populus. Stable isotope incorporation confirmed a hydroxycinnamate-benzoate origin of the salicyl moiety of PGs, and provided the first empirical evidence that the bioactive hydroxycyclohexenone moiety of salicortin is also a phenylpropanoid derivative [5]. Therefore it is unlikely that PG biosynthesis involves the salicylic acid pathway. To further address any possible involvement of the isochorismate pathway in PG biosynthesis, isochorismate synthase (ICS) was characterized. ICS is present as a single-gene in most sequenced plant genomes, but is duplicated in Arabidopsis. In Arabidopsis, chorismate-derived SA is the obligatory route for defense signaling, mediated by AtICS1 in response to various biotic and abiotic cues. In contrast, the single-copy Populus ICS is not stress-inducible, and is involved in biosynthesis of phylloquinone for photosynthetic electron transport [2]. We found no evidence of ICS involvement in SA or PG biosynthesis in transgenic Populus, pointing to lineage-specific evolution of the ICS-derived SA pathway in Arabidopsis. We transformed Populus with the bacterial genes for the biosynthesis and degradation of SA for a more in-depth investigation of the possibility of an SA interaction with PG regulation. SA-hyperaccumulating and SA-deficient lines were generated by expressing a salicylate synthase and a salicylate hydroxylase, respectively. SA was converted to SA-glycoside (SAG) and gentisic acid-glucoside (GAG) in the hyperaccumulating lines. SAG and GAG were very low in wild-type and were not detected in the SA-deficient lines. Despite these clear differences, no changes in PG levels were detected. These results argue against SA as potential precursor of PGs. Survival and establishment of rooted cuttings were negatively affected by SA-hyperaccumulation. Once established, however, growth rates were similar among plant lines, in sharp contrast to SA-over-producing Arabidopsis. SA-hyperaccumulating lines exhibited altered thermal tolerance, based on electrolyte leakage assays and metabolite profiling. Together, our results provide support for a phenylpropanoid origin of PGs, and argue against the involvement of SA in PG biosynthesis. The data is consistent with complementary roles for SA and PG in Populus fitness. A number of other experiments were conducted to investigate the regulation of PG homeostasis in Populus. Administration of a putative PG precursor salicyl alcohol to cell cultures yielded the glucoside, salicin. Salicyl alcohol-feeding also altered the partitioning of carbon into condensed tannin (CT) biosynthesis, another quantitatively important phenylpropanoid product [6]. Salicyl alcohol-feeding induced expression of several glycosyltransferases (GT1), as well as genes associated with sucrose catabolism, glycolysis and the Krebs cycle, presumably to accommodate the increased glycosylation. Conversely, transcript levels of most of the flavonoid pathway genes were reduced, consistent with reduced CT synthesis. Given that glycosylation was the only PG biosynthetic step occurring in the fed-cells, the results suggest that glycosylation of phenolic products can play a role in regulating the tradeoff between competing chemical defenses, e.g., PGs and CTs. Correlation analysis was used to identify PG-coregulated genes from a number of inductive treatments. One such candidate, SUT4 encoding a tonoplast sucrose transporter, was of particular interest because of the reported salicin transport activity of its Arabidopsis ortholog. RNAi-silencing of SUT4 altered sucrose distribution between source and sink organs, and reduced PG accrual by 20-30%, accompanied by altered biomass partitioning [7]. Chemical and molecular analyses revealed a complex network linking PG accrual and carbohydrate homeostasis. PG-coregulated GT1 members were also targeted for characterization, due to the prominent role of glycosylation in PG biosynthesis. We identified a novel salicyl alcohol glycosyltransferase (UGT71L1). Over-expression of UGT71L1 in transgenic Populus led to a ~2-fold increase in concentrations of salicin and salicortin in roots. The quantitative effect on secondary metabolism is significant, as PGs are the second most abundant non-structural phenolics, after CTs, in the roots of this poplar clone. UGT71L1 is phylogenetically distinct from the well-characterized SAGTs. It belongs to a Populus-specific clade with no close homologs in Arabidopsis, Vitis,Medicago and Oryza, consistent with the limited taxonomic range of PGs. Overall, the experiments described highlight the important contributions of sugar transport and phenolic glycosylation to PG homeostasis, while also showing that SA and PGs make independent but complementary contributions toward the maintenance of Populus fitness.

Sinigrin (SIN) and allyl isothiocyanate (AITC) are compounds found in high concentrations in Brassica family vegetables, especially in Brussels sprouts. Recently, they have been used as a nutrition supplement for their preventive and medicinal effect on some types of cancer and other diseases. In this research, nutritional significance of parent glucosinolate sinigrin 50 μmol/kg b. w./day and its degradation product allyl isothiocyanate 25 μmol/kg b. w./day and 50 μmol/kg b. w./day was studied by the evaluation of their influence on some parameters of carbohydrate and lipid metabolism in an animal rat model in vivo after their single (4 h) and 2 weeks oral administration. Additionally, the aim of this trial was to evaluate the direct action of AITC on basal and epinephrine-induced lipolysis in isolated rat adipocytes at concentration 1 μM, 10 μM and 100 μM in vitro. Sole AITC after 4 h of its ingestion caused liver triacylglycerols increment at both doses and glycaemia only at the higher dose. Multiple SIN treatment showed its putative bioconversion into AITC. It was found that SIN and AITC multiple administration in the same way strongly disturbed lipid and carbohydrate homeostasis, increasing esterified and total cholesterol, free fatty acids and lowering tracylglycerols in the blood serum. Additionally, AITC at both doses elevated insulinaemia and liver glycogen enhancement. The in vitro experiment revealed that AITC potentiated basal lipolysis process at 10 μM, and had stimulatory effect on epinephrine action at 1 μM and 10 μM. The results of this study demonstrated that the effect of SIN and AITC is multidirectional, indicating its impact on many organs like liver as well as pancreas, intestine in vivo action and rat adipocytes in vitro. Whilst consumption of cruciferous vegetables at levels currently considered “normal” seems to be beneficial to human health, this data suggest that any large increase in intake could conceivably lead to undesirable effect. This effect is potentiated with time of action of the examined compounds, whose influence is rather adverse for the majority of metabolic pathways (liver steatosis at short duration and insulinaemia, cholesterolaemia at long time treatment). Beneficial action of AITC concerned intensified hydrolysis of TG in the blood serum with a simultaneous lipolysis in adipocytes.

Background Screening tests for Trisomy 21 (T21), also known as Down syndrome, are routinely performed for the majority of pregnant women. However, current tests rely on either evaluating non-specific markers, which lead to false negative and false positive results, or on invasive tests, which while highly accurate, are expensive and carry a risk of fetal loss. We outline a novel, rapid, highly sensitive, and targeted approach to non-invasively detect fetal T21 using maternal plasma DNA. Methods and Findings Highly heterozygous tandem Single Nucleotide Polymorphism (SNP) sequences on chromosome 21 were analyzed using High-Fidelity PCR and Cycling Temperature Capillary Electrophoresis (CTCE). This approach was used to blindly analyze plasma DNA obtained from peripheral blood from 40 high risk pregnant women, in adherence to a Medical College of Wisconsin Institutional Review Board approved protocol. Tandem SNP sequences were informative when the mother was heterozygous and a third paternal haplotype was present, permitting a quantitative comparison between the maternally inherited haplotype and the paternally inherited haplotype to infer fetal chromosomal dosage by calculating a Haplotype Ratio (HR). 27 subjects were assessable; 13 subjects were not informative due to either low DNA yield or were not informative at the tandem SNP sequences examined. All results were confirmed by a procedure (amniocentesis/CVS) or at postnatal follow-up. Twenty subjects were identified as carrying a disomy 21 fetus (with two copies of chromosome 21) and seven subjects were identified as carrying a T21 fetus. The sensitivity and the specificity of the assay was 100% when HR values lying between 3/5 and 5/3 were used as a threshold for normal subjects. Conclusions In summary, a targeted approach, based on calculation of Haplotype Ratios from tandem SNP sequences combined with a sensitive and quantitative DNA measurement technology can be used to accurately detect fetal T21 in maternal plasma when sufficient fetal DNA is present in maternal plasma., Medical College of Wisconsin. Dept. of Surgery, Medical College of Wisconsin. Biotechnology and Bioengineering Center (Inducement Grant Fund), Wallace H. Coulter Foundation, Tandem Diagnostics (Firm), National Science Foundation (U.S.) (NSF#0438604 )

SUMMARYThe regulation of energy homeostasis is fundamental to all organisms. The Drosophila fat body serves as a repository for both triglycerides and glycogen, combining the energy storage functions of mammalian adipose and hepatic tissues, respectively. Here we show that mutation of the Drosophila adipokinetic hormone receptor (AKHR), a functional analog of the mammalian glucagon receptor, leads to abnormal accumulation of both lipid and carbohydrate. As a consequence of their obese phenotypes, AKHR mutants are markedly starvation resistant. We show that AKHR is expressed in the fat body, and, intriguingly, in a subset of gustatory neurons that mediate sweet taste. Genetic rescue experiments establish that the metabolic phenotypes arise exclusively from the fat body AKHR expression. Behavioral experiments demonstrate that AKHR mutants are neither sedentary nor hyperphagic, suggesting the metabolic abnormalities derive from a genetic propensity to retain energy stores. Taken together, our results indicate that a single endocrine pathway contributes to both lipid and carbohydrate catabolism in the Drosophila fat body.

Introduction: It is well recognized that there is a close relationship between TSH and PRL levels. The aim of this study was to evaluate the impact of insulin sensitivity on the association between TSH and PRL in euthyroid obese subjects. Material and Methods: Retrospective cross-sectional analysis was carried out on 165 euthyroid obese or overweight female patients. Prolactin, TSH, free thyroxine (FT4), free triiodothyronine (FT3), fasting plasma levels of insulin and glucose, postprandial levels of glucose, homeostasis model assessment (HOMA) for insulin resistance (HOMA-IR) and insulin secretion (HOMA-β cell), body weight, height, body mass index (BMI) and waist circumference were assessed. Statistical tests used were unpaired Student's t-test adjusted by Bonferroni's method and Pearson correlations with Bonferroni corrections. Results: There was no significant difference in prolactin levels between insulin sensitive and resistant subjects. Compared to insulin sensitive subjects, TSH levels were higher in insulin resistant subjects but it was not statistically significant. We observed significant positive correlation between prolactin and TSH in insulin sensitive and normoglycemic subjects (r=0.273, p=0.039 and r=0.253, p=0.023, respectively) but this correlation was lost in insulin resistant subjects and subjects who had fasting glucose levels ≥100 mg/dl (r=0.057, p=0.609 and r=0.090, p=0.404, respectively). Conclusions: The findings of this study provide some clues about the relationship between PRL and TSH in insulin sensitive obese subjects. The insulin sensitivity and carbohydrate homeostasis seem to be involved in relationship with PRL and TSH by the brain via serotoninergic and dopaminergic system. © J. A. Barth Verlag in Georg Thieme Verlag KG.