Epigenetic Mechanisms of Gene Regulation in Amyotrophic Lateral Sclerosis.

Despite being clinically described 150 years ago, the mechanisms underlying amyotrophic lateral sclerosis (ALS) pathogenesis have not yet been fully understood. Studies in both animal models of ALS and human patients reveal a plethora of alterations such as increased glutamate-mediated excitotoxicity, redox stress, increased apoptosis, defective axonal transport, protein-misfolding events, mitochondrial impairment and sustained unregulated immune responses. Regardless of being sporadic or familiar ALS, the final outcome at the cellular level is the death of upper and lower motor neurons, and once diagnosed, ALS is typically lethal within the next 5 years. There are neither clear biomarkers nor therapeutic or disease-modifying treatments for ALS.Accumulating evidence supports the concept that epigenetic-driven modifications, including altered chromatin remodelling events, RNA editing and non-coding RNA molecules, might shed light into the pathogenic mechanisms underlying sporadic/familiar ALS onset and/or severity to facilitate the identification of effective therapies, early diagnosis and potentially early-stage therapeutic interventions to increase the survival outcome of ALS patients.

Genome-Wide Association Study of the Modified Stumvoll Insulin Sensitivity Index Identifies BCL2 and FAM19A2 as Novel Insulin Sensitivity Loci.

Genome-wide association studies (GWAS) have found few common variants that influence fasting measures of insulin sensitivity. We hypothesized that a GWAS of an integrated assessment of fasting and dynamic measures of insulin sensitivity would detect novel common variants. We performed a GWAS of the modified Stumvoll Insulin Sensitivity Index (ISI) within the Meta-Analyses of Glucose and Insulin-Related Traits Consortium. Discovery for genetic association was performed in 16,753 individuals, and replication was attempted for the 23 most significant novel loci in 13,354 independent individuals. Association with ISI was tested in models adjusted for age, sex, and BMI and in a model analyzing the combined influence of the genotype effect adjusted for BMI and the interaction effect between the genotype and BMI on ISI (model 3). In model 3, three variants reached genome-wide significance: rs13422522 (NYAP2; P = 8.87 × 10(-11)), rs12454712 (BCL2; P = 2.7 × 10(-8)), and rs10506418 (FAM19A2; P = 1.9 × 10(-8)). The association at NYAP2 was eliminated by conditioning on the known IRS1 insulin sensitivity locus; the BCL2 and FAM19A2 associations were independent of known cardiometabolic loci. In conclusion, we identified two novel loci and replicated known variants associated with insulin sensitivity. Further studies are needed to clarify the causal variant and function at the BCL2 and FAM19A2 loci.

Polymorphisms in the SCD1 gene are associated with indices of stearoyl CoA desaturase activity and obesity: a prospective study.

SCOPE: The serum fatty acid (FA) composition is influenced by dietary fat and the endogenous production of FAs. Stearoyl CoA desaturase 1 (SCD1) is the rate-limiting enzyme catalyzing the synthesis of MUFAs from saturated FAs. Variations in SCD1 activity have been associated with obesity, diabetes, or inflammation. We evaluated the associations between genetic variation of the SCD1 gene, SCD1 activity, intake of oil, and obesity in a population-based prospective study in southern Spain. METHODS AND RESULTS: We collected phenotypic, metabolic, nutritional, and genetic information. The type of dietary fat was assessed from samples of cooking oil taken from the participants' kitchens and analyzed by GC. A total of nine single nucleotide polymorphisms (SNPs) of the SCD1 gene were analyzed by SNPlex technology. We found a significant association between SCD1 genetic variation and enzyme activity in four of nine polymorphisms studied. An interaction between rs10883463 and olive oil intake on the [18:1/18:0] desaturase index was found (p = 0.009). We also showed that genetic variations in the SCD1 gene were associated with obesity. CONCLUSION: Our results show a relationship between genetic variation of the SCD1 gene, enzyme activity, and the risk of obesity, an association that is not independent of the type of oil consumed.

Gut microbiota composition in male rat models under different nutritional status and physical activity and its association with serum leptin and ghrelin levels.

BACKGROUND: Several evidences indicate that gut microbiota is involved in the control of host energy metabolism. OBJECTIVE: To evaluate the differences in the composition of gut microbiota in rat models under different nutritional status and physical activity and to identify their associations with serum leptin and ghrelin levels. METHODS: In a case control study, forty male rats were randomly assigned to one of these four experimental groups: ABA group with food restriction and free access to exercise; control ABA group with food restriction and no access to exercise; exercise group with free access to exercise and feed ad libitum and ad libitum group without access to exercise and feed ad libitum. The fecal bacteria composition was investigated by PCR-denaturing gradient gel electrophoresis and real-time qPCR. RESULTS: In restricted eaters, we have found a significant increase in the number of Proteobacteria, Bacteroides, Clostridium, Enterococcus, Prevotella and M. smithii and a significant decrease in the quantities of Actinobacteria, Firmicutes, Bacteroidetes, B. coccoides-E. rectale group, Lactobacillus and Bifidobacterium with respect to unrestricted eaters. Moreover, a significant increase in the number of Lactobacillus, Bifidobacterium and B. coccoides-E. rectale group was observed in exercise group with respect to the rest of groups. We also found a significant positive correlation between the quantity of Bifidobacterium and Lactobacillus and serum leptin levels, and a significant and negative correlation among the number of Clostridium, Bacteroides and Prevotella and serum leptin levels in all experimental groups. Furthermore, serum ghrelin levels were negatively correlated with the quantity of Bifidobacterium, Lactobacillus and B. coccoides-Eubacterium rectale group and positively correlated with the number of Bacteroides and Prevotella. CONCLUSIONS: Nutritional status and physical activity alter gut microbiota composition affecting the diversity and similarity. This study highlights the associations between gut microbiota and appetite-regulating hormones that may be important in terms of satiety and host metabolism.

Gut microbiota in children with type 1 diabetes differs from that in healthy children: a case-control study.

BACKGROUND: A recent study using a rat model found significant differences at the time of diabetes onset in the bacterial communities responsible for type 1 diabetes modulation. We hypothesized that type 1 diabetes in humans could also be linked to a specific gut microbiota. Our aim was to quantify and evaluate the difference in the composition of gut microbiota between children with type 1 diabetes and healthy children and to determine the possible relationship of the gut microbiota of children with type 1 diabetes with the glycemic level. METHODS: A case-control study was carried out with 16 children with type 1 diabetes and 16 healthy children. The fecal bacteria composition was investigated by polymerase chain reaction-denaturing gradient gel electrophoresis and real-time quantitative polymerase chain reaction. RESULTS: The mean similarity index was 47.39% for the healthy children and 37.56% for the children with diabetes, whereas the intergroup similarity index was 26.69%. In the children with diabetes, the bacterial number of Actinobacteria and Firmicutes, and the Firmicutes to Bacteroidetes ratio were all significantly decreased, with the quantity of Bacteroidetes significantly increased with respect to healthy children. At the genus level, we found a significant increase in the number of Clostridium, Bacteroides and Veillonella and a significant decrease in the number of Lactobacillus, Bifidobacterium, Blautia coccoides/Eubacterium rectale group and Prevotella in the children with diabetes. We also found that the number of Bifidobacterium and Lactobacillus, and the Firmicutes to Bacteroidetes ratio correlated negatively and significantly with the plasma glucose level while the quantity of Clostridium correlated positively and significantly with the plasma glucose level in the diabetes group. CONCLUSIONS: This is the first study showing that type 1 diabetes is associated with compositional changes in gut microbiota. The significant differences in the number of Bifidobacterium, Lactobacillus and Clostridium and in the Firmicutes to Bacteroidetes ratio observed between the two groups could be related to the glycemic level in the group with diabetes. Moreover, the quantity of bacteria essential to maintain gut integrity was significantly lower in the children with diabetes than the healthy children. These findings could be useful for developing strategies to control the development of type 1 diabetes by modifying the gut microbiota.

Influence of red wine polyphenols and ethanol on the gut microbiota ecology and biochemical biomarkers.

BACKGROUND: Few studies have investigated the effect of dietary polyphenols on the complex human gut microbiota, and they focused mainly on single polyphenol molecules and select bacterial populations. OBJECTIVE: The objective was to evaluate the effect of a moderate intake of red wine polyphenols on select gut microbial groups implicated in host health benefits. DESIGN: Ten healthy male volunteers underwent a randomized, crossover, controlled intervention study. After a washout period, all of the subjects received red wine, the equivalent amount of de-alcoholized red wine, or gin for 20 d each. Total fecal DNA was submitted to polymerase chain reaction(PCR)-denaturing gradient gel electrophoresis and real-time quantitative PCR to monitor and quantify changes in fecal microbiota. Several biochemical markers were measured. RESULTS: The dominant bacterial composition did not remain constant over the different intake periods. Compared with baseline, the daily consumption of red wine polyphenol for 4 wk significantly increased the number of Enterococcus, Prevotella, Bacteroides, Bifidobacterium, Bacteroides uniformis, Eggerthella lenta, and Blautia coccoides-Eubacterium rectale groups (P < 0.05). In parallel, systolic and diastolic blood pressures and triglyceride, total cholesterol, HDL cholesterol, and C-reactive protein concentrations decreased significantly (P < 0.05). Moreover, changes in cholesterol and C-reactive protein concentrations were linked to changes in the bifidobacteria number. CONCLUSION: This study showed that red wine consumption can significantly modulate the growth of select gut microbiota in humans, which suggests possible prebiotic benefits associated with the inclusion of red wine polyphenols in the diet. This trial was registered at controlled-trials.com as ISRCTN88720134.

Trp64Arg polymorphism of the ADRB3 gene predicts hyperuricemia risk in a population from southern Spain.

OBJECTIVE: To study the role of Trp64Arg polymorphism of the ADRB3 gene in the risk of developing hyperuricemia in 1051 subjects from southern Spain, with a followup of 6 years. The inclusion of plasma levels of uric acid as a diagnostic criterion to define the metabolic syndrome is under discussion. Genes responsible for insulin resistance could contribute to the development of hyperuricemia. Previous cross-sectional studies have suggested ADRB3 as a possible candidate gene in the development of hyperuricemia and insulin resistance. METHODS: A prospective, population-based, cohort study of 1051 persons examined in 1997-98 and reassessed at a second examination 6 years later. The metabolic phenotype was assessed at baseline and again at the followup. Insulin resistance was measured by homeostasis model assessment. The Trp64Arg polymorphism of ADRB3 was detected by real-time polymerase chain reaction. Subjects were considered normouricemic if their serum uric acid levels were

Effect of the combination of the variants -75G/A APOA1 and Trp64Arg ADRB3 on the risk of type 2 diabetes (DM2).

OBJECTIVE: Numerous genes have been associated with the risk for type 2 diabetes mellitus (DM2). In an attempt to understand how specific variants of different genes interact and intervene in the molecular and physiological mechanisms of disorders such as diabetes or insulin resistance, the search for gene-gene interactions is constantly growing. We searched for a possible interaction between two polymorphisms (Trp64Arg of ADRB3 gene and -75G/A of APOA1gene) and the risk for DM2 in a population from southern Spain. DESIGN AND METHODS: A cross-sectional study in southern Spain of 1020 people, aged 18-65 years. All persons underwent a clinical, anthropometrical and biochemical evaluation, including an oral glucose tolerance test (OGTT). Insulin resistance was measured by homeostasis model of assessment (HOMA). The polymorphisms -75G/A of APOA1 and Trp64Arg of ADRB3 were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and real-time PCR, respectively. RESULTS: The genotype frequencies of the -75G/A polymorphism of the APOA1 gene were 62.7% GG, 25.7% GA and 11.6% AA, whereas for the Trp64Arg polymorphism of the ADRB3 gene, they were 87.5% Trp/Trp, 11.7% Trp/Arg and 0.8% Arg/Arg. Subjects with both gene variants had a greater odds ratio (OR) of having DM2 [OR = 5.5; 95% confidence interval (CI) = 1.2-23.5] than persons with one or none of the variants, after adjusting for age, sex, body mass index (BMI) and homeostasis model assessment of insulin resistance (HOMA-IR). CONCLUSIONS: Joint association of allele -75A (APOA1) and allele Arg64 (ADRB3) increase the risk of DM2 in a population from southern Spain.

Influence of age and sex on levels of anti-oxidized LDL antibodies and anti-LDL immune complexes in the general population.

Most studies of antibodies to oxidized LDL have been undertaken in patients with different diseases and cardiovascular risk factors. However, very few studies have researched the distribution and determining factors of antibodies to oxidized LDL in the general population. A total of 1,354 persons (817 females and 537 males) aged 5-65 years were included in this study. They were selected randomly from the population census of Málaga, in southern Spain. The females had lower levels of total cholesterol and triglycerides and higher levels of HDL-cholesterol and a very significant increase (P < 0.0001) in levels of anti-oxidized LDL [low density lipoprotein modified by malondialdehyde (MDA-LDL)] antibodies but no difference in levels of immune complexes consisting of LDL and IgG antibodies (anti-LDL immune complex). Younger persons (16-35 years) had higher levels of anti-oxidized LDL (MDA-LDL) antibodies than persons older than 35 years (P = 0.05). Levels of immune complexes were significantly higher (P = 0.05) in persons aged 5-15 years than in persons older than 40 years. A very weak association was found between levels of anti-oxidized LDL (MDA-LDL) antibodies and anti-LDL immune complexes. The higher prevalence of anti-oxidized LDL (MDA-LDL) antibodies in females and young persons is in agreement with studies that found an inverse association between atherosclerosis and the level of these antibodies.