Interplay of early-life nutritional programming on obesity, inflammation and epigenetic outcomes

The huge health burden accompanying obesity is not only attributable to inadequate dietary and sedentary lifestyle habits, since a predisposing genetic make-up and other putative determinants concerning easier weight gain and fat deposition have been reported. Thus, several investigations aiming to understand energy metabolism and body composition maintenance have been performed considering the participation of perinatal nutritional programming and epigenetic processes as well as inflammation phenomena. The Developmental Origins of Health and Disease hypothesis and inheritance-oriented investigations concerning gene–nutrient interactions on energy homoeostasis and metabolic functions have suggested that inflammation could be not only a comorbidity of obesity but also a cause. There are several examples about the role of nutritional interventions in pregnancy and lactation, such as energetic deprivation, protein restriction and excess fat, which determine a cluster of disorders affecting energy efficiency in the offspring as well as different metabolic pathways, which are mediated by epigenetics encompassing the chromatin information encrypted by DNA methylation patterns, histone covalent modifications and non-coding RNA or microRNA. Epigenetic mechanisms may be boosted or impaired by dietary and environmental factors in the mother, intergenerationally or transiently transmitted, and could be involved in the obesity and inflammation susceptibility in the offspring. The aims currently pursued are the early identification of epigenetic biomarkers concerned in individual's disease susceptibility and the description of protocols for tailored dietary treatments/advice to counterbalance adverse epigenomic events. These approaches will allow diagnosis and prognosis implementation and facilitate therapeutic strategies in a personalised ‘epigenomically modelled’ manner to combat obesity and inflammation

Fat-to-glucose interconversion by hydrodynamic transfer of two glyoxylate cycle enzyme genes

The glyoxylate cycle, which is well characterized in higher plants and some microorganisms but not in vertebrates, is able to bypass the citric acid cycle to achieve fat-to-carbohydrate interconversion. In this context, the hydrodynamic transfer of two glyoxylate cycle enzymes, such as isocytrate lyase (ICL) and malate synthase (MS), could accomplish the shift of using fat for the synthesis of glucose. Therefore, 20 mice weighing 23.37 +/- 0.96 g were hydrodinamically gene transferred by administering into the tail vein a bolus with ICL and MS. After 36 hours, body weight, plasma glucose, respiratory quotient and energy expenditure were measured. The respiratory quotient was increased by gene transfer, which suggests that a higher carbohydrate/lipid ratio is oxidized in such animals. This application could help, if adequate protocols are designed, to induce fat utilization for glucose synthesis, which might be eventually useful to reduce body fat depots in situations of obesity and diabete

Dietary supplementation with methyl donors reduces fatty liver and modifies the fatty acid synthase DNA methylation profile in rats fed an obesogenic diet

Non-alcoholic fatty liver disease (NAFLD) is one of the first hepatic manifestations of metabolic syndrome, whose progression can lead to cirrhosis and hepatic carcinoma. Interestingly, methyl donor supplementation could improve obesogenic diet-induced hepatic triglyceride accumulation. The aim of this research is to describe methyl donor effects on a high-fat-sucrose (HFS) diet in both sexes and epigenetic changes induced on fatty acid synthase (FASN) promoter methylation pattern as well as gene expression of NAFLD key metabolic genes. Twenty-four male and 28 female Wistar rats were assigned to three dietary groups: control, HFS, and HFS supplemented with methyl donors (choline, betaine, vitamin B12, and folic acid). After 8 weeks of treatment, somatic, biochemical, mRNA, and epigenetic measurements were performed. Rats fed the HFS diet presented an overweight phenotype and alterations in plasma biochemical measurements. Methyl donor supplementation reverted the HFS-diet-induced hepatic triglyceride accumulation. Analysis of FASN promoter cytosine methylation showed changes in both sexes due to the obesogenic diet at -1,096, -780, -778, and -774 CpG sites with respect to the transcriptional start site. Methyl donor supplementation modified DNA methylation at -852, -833, -829, -743, and -733 CpGs depending on the sex. RT-PCR analysis confirmed that FASN expression tended to be altered in males. Our findings reinforce the hypothesis that methyl donor supplementation can prevent hepatic triglyceride accumulation induced by obesogenic diets in both sexes. Changes in liver gene expression profile and epigenetic-mediated mechanisms related to FASN DNA hypermethylation could be involved in methyl donor-induced NAFLD improvement

Leptin and TNF-alpha promoter methylation levels measured by MSP could predict the response to a low-calorie diet

Obesity-associated adipose tissue enlargement is characterized by an enhanced proinflammatory status and an elevated secretion of adipokines such as leptin and cytokines such as TNF-alpha. Among the different mechanisms that could underlie the interindividual differences in obesity, epigenetic regulation of gene expression has emerged as a potentially important determinant. Therefore, twenty-seven obese women (age: 32-50 years; baseline Body Mass Index, BMI: 34.4±4.2 Kg/m2) were prescribed an eight-week Low-Calorie-Diet and epigenetic marks were assessed. Baseline and endpoint anthropometric parameters were measured and blood samples were drawn. Genomic DNA and RNA from adipose tissue biopsies were isolated before and after the dietary intervention. Leptin and TNF-alpha promoter methylation were measured by MSP after bisulfite treatment and gene expression was also analyzed. Obese women with a successful weight loss (≥5% of initial body weight, n=21) improved the lipid profile and fat mass percentage (-12%, p<0.05). Both systolic (-5%, p<0.05) and diastolic (-8%, p<0.01) blood pressures significantly decreased. At baseline women with better response to the dietary intervention showed lower promoter methylation levels of leptin (-47%, p<0.05) and TNF-alpha (-39%, p=0.071) than the non-responder group (n=6), while no differences were found between responder and non-responder group in leptin and TNF-alpha gene expression analysis. These data suggest that leptin and TNF-alpha methylation levels could be used as epigenetic biomarkers concerning the response to a Low-Calorie-Diet. Indeed, methylation profile could help to predict the susceptibility to weight loss as well as some comorbidities such as hypertension or type 2 diabetes

Impact of hypoxia exposure, combined with induced maternal obesity, on gestating sprague dawley dams

Abstract Obesity is now considered to be a global epidemic, impacting a great number of women and leading to a higher risk of obstetrical and gestational complications. One of such possible adverse outcomes in gestating female is placental hypoxia, which has been related to vascular remodeling and hypertension, as well as adaptive phenomena to reduce levels of oxidative stress and damage. A pool of female Sprague Dawley rats (n=63) was first assigned into two dietary groups (Control and High Sugar). Following mating, the pregnant rats (n=39) were again distributed into two oxygen treatment groups (Normoxia and Hypoxia) for 3 weeks, and tissue sampling and biochemical analyses were carried out. The main results of this study are the following: 1) Hypoxia during gestation may lead to a reduction in the average number of pups per mother, 2) Hypoxia during gestation treatment may lead to a decrease in maternal serum TG levels, and consequentially 3) Hypoxia during gestation may lead to a reduction in TyG Index levels. These results suggest that hypoxia could generate a beneficial response in pregnant Sprague Dawley rats to salvage both maternal and fetal viability. Thus, reproducing mild hypoxic conditions could result being a viable therapeutic option in preventing gestational adversities. In conclusion, progress was made in recognizing the possible role of a mild hypoxic environment in stimulating a maternal protective response

Maternal methyl donors supplementation during lactation prevents the hyperhomocysteinemia induced by a high-fat-sucrose intake by dams

Maternal perinatal nutrition may program offspring metabolic features. Epigenetic regulation is one of the candidate mechanisms that may be affected by maternal dietary methyl donors intake as potential controllers of plasma homocysteine levels. Thirty-two Wistar pregnant rats were randomly assigned into four dietary groups during lactation: control, control supplemented with methyl donors, high-fat-sucrose and high-fat-sucrose supplemented with methyl donors. Physiological outcomes in the offspring were measured, including hepatic mRNA expression and global DNA methylation after weaning. The newborns whose mothers were fed the obesogenic diet were heavier longer and with a higher adiposity and intrahepatic fat content. Interestingly, increased levels of plasma homocysteine induced by the maternal high-fat-sucrose dietary intake were prevented in both sexes by maternal methyl donors supplementation. Total hepatic DNA methylation decreased in females due to maternal methyl donors administration, while Dnmt3a hepatic mRNA levels decreased accompanying the high-fat-sucrose consumption. Furthermore, a negative association between Dnmt3a liver mRNA levels and plasma homocysteine concentrations was found. Maternal high-fat-sucrose diet during lactation could program offspring obesity features, while methyl donors supplementation prevented the onset of high hyperhomocysteinemia. Maternal dietary intake also affected hepatic DNA methylation metabolism, which could be linked with the regulation of the methionine-homocysteine cycle

Generalized Ricci Curvature Bounds for Three Dimensional Contact Subriemannian manifolds

Measure contraction property is one of the possible generalizations of Ricci curvature bound to more general metric measure spaces. In this paper, we discover sufficient conditions for a three dimensional contact subriemannian manifold to satisfy this property.Comment: 49 page

A dual epigenomic approach for the search of obesity biomarkers: DNA methylation in relation to diet-induced weight loss

Epigenetics could help to explain individual differences in weight loss after an energy-restriction intervention. Here, we identify novel potential epigenetic biomarkers of weight loss, comparing DNA methylation patterns of high and low responders to a hypocaloric diet. Twenty-five overweight or obese men participated in an 8-wk caloric restriction intervention. DNA was isolated from peripheral blood mononuclear cells and treated with bisulfite. The basal and endpoint epigenetic differences between high and low responders were analyzed by methylation microarray, which was also useful in comparing epigenetic changes due to the nutrition intervention. Subsequently, MALDI-TOF mass spectrometry was used to validate several relevant CpGs and the surrounding regions. DNA methylation levels in several CpGs located in the ATP10A and CD44 genes showed statistical baseline differences depending on the weight-loss outcome. At the treatment endpoint, DNA methylation levels of several CpGs on the WT1 promoter were statistically more methylated in the high than in the low responders. Finally, different CpG sites from WT1 and ATP10A were significantly modified as a result of the intervention. In summary, hypocaloric-diet-induced weight loss in humans could alter DNA methylation status of specific genes. Moreover, baseline DNA methylation patterns may be used as epigenetic markers that could help to predict weight loss

Integrated microfluidic tmRNA purification and real-time NASBA device for molecular diagnostics.

We demonstrate the first integrated microfluidic tmRNA purification and nucleic acid sequence-based amplification (NASBA) device incorporating real-time detection. The real-time amplification and detection step produces pathogen-specific response in < 3 min from the chip-purified RNA from 100 lysed bacteria. On-chip RNA purification uses a new silica bead immobilization method. On-chip amplification uses custom-designed high-selectivity primers and real-time detection uses molecular beacon fluorescent probe technology; both are integrated on-chip with NASBA. Present in all bacteria, tmRNA (10Sa RNA) includes organism-specific identification sequences, exhibits unusually high stability relative to mRNA, and has high copy number per organism; the latter two factors improve the limit of detection, accelerate time-to-positive response, and suit this approach ideally to the detection of small numbers of bacteria. Device efficacy was demonstrated by integrated on-chip purification, amplification, and real-time detection of 100 E. coli bacteria in 100 microL of crude lysate in under 30 min for the entire process

The chaperone protein clusterin may serve as a cerebrospinal fluid biomarker for chronic spinal cord disorders in the dog

Chronic spinal cord dysfunction occurs in dogs as a consequence of diverse aetiologies, including long-standing spinal cord compression and insidious neurodegenerative conditions. One such neurodegenerative condition is canine degenerative myelopathy (DM), which clinically is a challenge to differentiate from other chronic spinal cord conditions. Although the clinical diagnosis of DM can be strengthened by the identification of the Sod1 mutations that are observed in affected dogs, genetic analysis alone is insufficient to provide a definitive diagnosis. There is a requirement to identify biomarkers that can differentiate conditions with a similar clinical presentation, thus facilitating patient diagnostic and management strategies. A comparison of the cerebrospinal fluid (CSF) protein gel electrophoresis profile between idiopathic epilepsy (IE) and DM identified a protein band that was more prominent in DM. This band was subsequently found to contain a multifunctional protein clusterin (apolipoprotein J) that is protective against endoplasmic reticulum (ER) stress-mediated apoptosis, oxidative stress, and also serves as an extracellular chaperone influencing protein aggregation. Western blot analysis of CSF clusterin confirmed elevated levels in DM compared to IE (p &#60; 0.05). Analysis of spinal cord tissue from DM and control material found that clusterin expression was evident in neurons and that the clusterin mRNA levels from tissue extracts were elevated in DM compared to the control. The plasma clusterin levels was comparable between these groups. However, a comparison of clusterin CSF levels in a number of neurological conditions found that clusterin was elevated in both DM and chronic intervertebral disc disease (cIVDD) but not in meningoencephalitis and IE. These findings indicate that clusterin may potentially serve as a marker for chronic spinal cord disease in the dog; however, additional markers are required to differentiate DM from a concurrent condition such as cIVDD