Influence of ALA54THR polymorphism of fatty acid-binding protein 2 on obesity and cardiovascular risk factors.

A transition of G to A at codon 54 of FABP2 results in an amino acid substitution (Ala54 to Thr54). This polymorphism was associated with some cardiovascular risk factors. The aim of our study was to investigate the influence of Thr54 polymorphism in the FABP2 gene on obesity anthropometric parameters and cardiovascular risk factors. A population of 226 obesity (body mass index >30) nondiabetic outpatients were analyzed. An indirect calorimetry, tetrapolar electrical bioimpedance, blood pressure, a serial assessment of nutritional intake with 3 days of written food records, and biochemical analysis (lipid profile, adipocytokines, insulin, CRP, and lipoprotein-a) were performed. The statistical analysis was performed for the combined ALA54/THR54 and THR54/THR54 as a mutant group and wild type ALA54/ALA54 as a second group. Two-hundred and twenty-six patients gave informed consent and were enrolled in the study. The mean age was 44.2+/-16 years and the mean BMI 35.1+/-5.1, with 63 males (28.3%) and 163 females (71.7%). One-hundred and thirteen patients (50%) had the genotype ALA54/ALA54 (wild group) and 113 (50%) patients had the genotype ALA54/THR54 (91 patients, 40.2%) or THR54/THR54 (22 patients, 9.8%) (mutant group). The ANOVA analysis of the three groups ( ALA54/THR54, THR54/THR54 and ALA54/ALA54) shows a higher levels of fat mass in Thr54/Thr54 group (45.6+/-14.6 kg) than Ala54/Ala54 (37.5+/-11.2 kg: p<0.05), without differences with Ala54/Thr54 group (41.2+/-13.5 kg). CRP, IL-6, and lipoprotein-a were higher in mutant group ( ALA54/THR54, THR54/THR54) than in wild group ( ALA54/ALA54). The novel finding of this study is the association of the Thr54/Ala54 and Thr54/Thr54 FABP2 phenotypes with higher levels of C reactive protein, IL6, and lipoprotein-a. Further studies are needed to explain the role of this polymorphism in different populations.     

Structures of randomly generated mutants of T4 lysozyme show that protein stability can be enhanced by relaxation of strain and by improved hydrogen bonding via bound solvent.

The structures of three mutants of bacteriophage T4 lysozyme selected using a screen designed to identify thermostable variants are described. Each of the mutants has a substitution involving threonine. Two of the variants, Thr 26-->Ser (T26S) and Thr 151-->Ser (T151S), have increased reversible melting temperatures with respect to the wild-type protein. The third, Ala 93-->Thr (A93T), has essentially the same stability as wild type. Thr 26 is in the wall of the active-site cleft. Its replacement with serine results in the rearrangement of nearby residues, most notably Tyr 18, suggesting that the increase in stability may result from the removal of strain. Thr 151 in the wild-type structure is far from the active site and appears to sterically prevent the access of solvent to a preformed binding site. In the mutant, the removal of the methyl group allows access to the solvent binding site and, in addition, the Ser 151 hydroxyl rotates to a new position so that it also contributes to solvent binding. Residue 93 is in a highly exposed site on the surface of the molecule, and presumably is equally solvent exposed in the unfolded protein. It is, therefore, not surprising that the substitution Ala 93-->Thr does not change stability. The mutant structures show how chemically similar mutations can have different effects on both the structure and stability of the protein, depending on the structural context. The results also illustrate the power of random mutagenesis in obtaining variants with a desired phenotype.(ABSTRACT TRUNCATED AT 250 WORDS)     

Association between FABP2 Ala54Thr polymorphisms and type 2 diabetes mellitus risk: a HuGE Review and Meta‐Analysis

Many studies have examined the association between the FABP2 (rs1799883) Ala54Thr gene polymorphism and type 2 diabetes mellitus risk (T2DM) in various populations, but their results have been inconsistent. To assess this relationship more precisely, A HuGE review and meta‐analysis were performed. The PubMed and CNKI database was searched for case‐control studies published up to April 2014. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, 13 studies, comprising 2020 T2DM cases and 2910 controls were included. Overall, for the Thr carriers (Ala/Thr and Thr/Thr) versus the wild‐type homozygotes (Ala/Ala), the pooled OR was 1.18 (95% CI = 1.04–1.34, P = 0.062 for heterogeneity), for Thr/Thr versus Ala/Ala the pooled OR was 1.17 (95% CI = 1.05–1.41 P = 0.087 for heterogeneity). In the stratified analysis by ethnicity, the significantly risks were found among Asians but not Caucasians. This meta‐analysis suggests that the FABP2 (rs1799883) Ala54Thr polymorphisms are associated with increased susceptibility to T2DM risk among Asians but not Caucasians.     

Study of wild type and genetically modified reaction centers from Rhodobacter capsulatus: structural comparison with Rhodopseudomonas viridis and Rhodobacter sphaeroides.

Reaction centers from the purple bacterium Rhodobacter (Rb.) capsulatus and from two mutants ThrL226-->Ala and IleL229-->Ser, modified in the binding protein pocket of the secondary quinone acceptor (QB), have been studied by flash-induced absorbance spectroscopy. In ThrL226-->Ala, the binding affinities for endogenous QB (ubiquinone 10) and UQ6 are found to be two to three times as high as the wild type. In contrast, in IleL229-->Ser, the binding affinity for UQ6 is decreased about three times compared to the wild type. In ThrL226-->Ala, a markedly increased sensitivity (approximately 30 times) to o-phenanthroline is observed. In Rhodopseudomonas viridis, where Ala is naturally in position L226, the sensitivity to o-phenanthroline is close to that observed in ThrL226-->Ala. We propose that the presence of Ala in position L226 is responsible for the high sensitivity to that inhibitor. The pH dependencies of the rate constants of P+QB- (kBP) charge recombination kinetics (P is a dimer of bacteriochlorophyll, and QB is the secondary quinone electron acceptor) show destabilization of QB- in ThrL226-->Ala and IleL229-->Ser, compared to the wild type. At low pH, similar apparent pK values of protonation of amino acids around QB- are measured in the wild type and the mutants. In contrast to Rb. sphaeroides, in the wild type Rb. capsulatus, kBP substantially increases in the pH range 7-10.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chronic Running Exercise Alleviates Early Progression of Nephropathy with Upregulation of Nitric Oxide Synthases and Suppression of Glycation in Zucker Diabetic Rats

Exercise training is known to exert multiple beneficial effects including renal protection in type 2 diabetes mellitus and obesity. However, the mechanisms regulating these actions remain unclear. The present study evaluated the effects of chronic running exercise on the early stage of diabetic nephropathy, focusing on nitric oxide synthase (NOS), oxidative stress and glycation in the kidneys of Zucker diabetic fatty (ZDF) rats. Male ZDF rats (6 weeks old) underwent forced treadmill exercise for 8 weeks (Ex-ZDF). Sedentary ZDF (Sed-ZDF) and Zucker lean (Sed-ZL) rats served as controls. Exercise attenuated hyperglycemia (plasma glucose; 242 ± 43 mg/dL in Sed-ZDF and 115 ± 5 mg/dL in Ex-ZDF) with increased insulin secretion (plasma insulin; 2.3 ± 0.7 and 5.3 ± 0.9 ng/mL), reduced albumin excretion (urine albumin; 492 ± 70 and 176 ± 11 mg/g creatinine) and normalized creatinine clearance (9.7 ± 1.4 and 4.5 ± 0.8 mL/min per body weight) in ZDF rats. Endothelial (e) and neuronal (n) NOS expression in kidneys of Sed-ZDF rats were lower compared with Sed-ZL rats (p<0.01), while both eNOS and nNOS expression were upregulated by exercise (p<0.01). Furthermore, exercise decreased NADPH oxidase activity, p47^phox expression (p<0.01) and α-oxoaldehydes (the precursors for advanced glycation end products) (p<0.01) in the kidneys of ZDF rats. Additionally, morphometric evidence indicated renal damage was reduced in response to exercise. These data suggest that upregulation of NOS expression, suppression of NADPH oxidase and α-oxoaldehydes in the kidneys may, at least in part, contribute to the renal protective effects of exercise in the early progression of diabetic nephropathy in ZDF rats. Moreover, this study supports the theory that chronic aerobic exercise could be recommended as an effective non-pharmacological therapy for renoprotection in the early stages of type 2 diabetes mellitus and obesity.     

Intestinal fatty acid binding protein and microsomal triglyceride transfer protein polymorphisms in French-Canadian youth

Growing evidence suggests an association between lipid abnormalities and fatty acid binding protein (FABP) and microsomal triglyceride transfer protein (MTP) gene variants. Our objectives were to determine whether Ala54Thr FABP2 and G-493T MTP polymorphisms are associated with increased risks of insulin resistance syndrome (IRS) in youth and/or modify the expression of accompanying dyslipidemia. Our study of 1,742 French-Canadians aged 9, 13, and 16 years did not provide evidence of a potential predisposition to IRS related to either FABP2 or MTP genotypes. However, we observed a heterogeneity of the FABP2 effect by IRS status on total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), and apolipoprotein B (apoB) concentrations (P for interaction=0.045, 0.018, and 0.017, respectively). Among the metabolic components of IRS, only triglyceride (TG) displayed an interaction with FABP2 polymorphism: compared with Thr/Ala and Ala/Ala, the Thr/Thr genotype was associated with a steeper increase in TC, LDL-C, and apoB parallel to TG concentrations (P <0.001). IRS did not modify the associations between the MTP polymorphism and any of the biochemical parameters. Our study suggests that the effects of FABP2 allelic variations on lipid traits are context dependent, indicating that this variant may play an important role in cardiovascular pathogenesis in the presence of IRS or hypertriglyceridemia.     

Functional role of proline and tryptophan residues highly conserved among G protein-coupled receptors studied by mutational analysis of the m3 muscarinic receptor.

Most G protein-coupled receptors contain a series of highly conserved proline and tryptophan residues within their hydrophobic transmembrane domains (TMD I-VII). To study their potential role in ligand binding and receptor function, the rat m3 muscarinic acetylcholine receptor was used as a model system. A series of mutant receptors in which the conserved proline and tryptophan residues were individually replaced with alanine and phenylalanine, respectively, was created and transiently expressed in COS-7 cells. [3H]N-methylscopolamine ([3H]NMS) saturation binding studies showed that three of the seven mutant receptors studied (Pro242-->Ala, TMD V; Pro505-->Ala, TMD VI; Pro540-->Ala, TMD VII) were expressed at 35-100 times lower levels than the wild-type receptor while displaying 'm3-like' antagonist binding affinities. Pro201-->Ala (TMD IV) showed drastically reduced binding affinities (up to 450-fold) for both muscarinic agonists and antagonists. Whereas most mutant receptors retained strong functional activity, Pro540-->Ala (TMD VII) was found to be severely impaired in its ability to stimulate carbachol-induced phosphatidyl inositol hydrolysis (Emax approximately 25% of wild type m3). Interestingly, this mutant receptor bound muscarinic agonists with 7- to 19-fold higher affinities than the wild type receptor. The Trp-->Phe substitutions (Trp192-->Phe, TMD IV; Trp503-->Phe, TMD VI; Trp530-->Phe, TMD VII) resulted in less pronounced changes (compared with the Pro-->Ala mutant receptors) in both ligand binding and receptor function. Our data indicate that the proline residues that are highly conserved across the entire superfamily of G protein-coupled receptors play key roles in receptor expression, ligand binding and receptor activation.     

Intestinal FABP2 A54T Polymorphism: Association with Insulin Resistance and Obesity in Women

Objective: To assess the association between the Ala54Thr genetic polymorphism of the fatty acid‐binding protein 2 (FABP2) gene with insulin resistance and obesity. Research Methods and Procedures: According to a sampling scheme based on BMI, 33 adult obese women (BMI ≥ 30) and 30 adult normal‐weight women (BMI > 18.5 and < 25 kg/m²) were recruited for this study. Women with chronic inflammatory diseases or acute pathology were excluded. Glucose, insulin, leptin, lipids, and tumor necrosis factor α (TNFα) were measured in fasting plasma samples. Insulin resistance was estimated through the homeostasis model assessment for insulin resistance method. The Ala54Thr allelic variant was determined by polymerase chain reaction, followed by restriction fragment‐length polymorphism analysis. Results: The Thr54 allele was more frequent in obese than in nonobese women (47.0% vs. 31.7; p = 0.08). Among obese women, higher TNFα concentrations were found when comparing the Thr54/Thr54 genotype (30.0 ± 7.1 pg/mL) with either the Ala54/Thr54 genotype (21.2 ± 8.4 pg/mL) or the Ala54/Ala44 genotype (20.1 ± 7.0 pg/mL) (p < 0.05). In addition, higher fasting plasma insulin and leptin levels were found among Thr54/Thr54 homozygotes compared with the other genotypes (p < 0.05). Discussion: Our results suggest that the Ala54Thr polymorphism of the FABP2 gene is associated with obesity and insulin resistance. The effect of this polymorphism might be mediated by elevated production of TNFα.     

Mutants at Ser277 of Xenopus cdc2 protein kinase induce oocyte maturation in the absence of the positive regulatory phosphorylation site Thr161.

The cdc2 protein kinase is an important regulatory protein for both meiosis and mitosis. Previously, we demonstrated that simultaneous mutation of Thr14-->Ala14 and Tyr15-->Phe15 in the Xenopus cdc2 protein results in an activated cdc2 mutant that induces maturation in resting oocytes. In addition, we confirmed the importance of the positive regulatory phosphorylation site, Thr161, by demonstrating that cdc2 mutants containing additional mutations of Thr161-->Ala161 or Glu161 are inactive in the induction of oocyte maturation. Here, we have analyzed the importance of an additional putative cdc2 phosphorylation site,Ser277. Single mutation of Ser277-->Asp277 or Ala277 had no effect on activity, and these mutants were unable to induce Xenopus oocyte maturation. However, the double mutant Ala161/Asp277 was capable of inducing oocyte maturation, suggesting that mutation of Ser277-->Asp277 could compensate for the mutation of Thr161-->Ala161. The Asp277 mutation could also compensate for the Ala161 mutation in the background of the activating mutations Ala14/Phe15. Although mutants containing the compensatory Ala161 and Asp277 mutations were capable of inducing oocyte maturation, these mutant cdc2 proteins lacked detectable in vitro kinase activity. Tryptic phosphopeptide mapping of mutant cdc2 protein and comparison with in vitro synthesized peptides indicated that Ser277 is not a major site of phosphorylation in Xenopus oocytes; however, we cannot rule out the possibility of phosphorylation at this site in a biologically active subpopulation of cdc2 molecules. The data presented here, together with prior reports of Ser277 phosphorylation in somatic cells, suggest an important role for Ser277 in the regulation of cdc2 activity. The regulatory role of Ser277 most likely involves its indirect effects on the nearby residue Arg275, which participates in a structurally important ion pair with Glu173, which lies in the same loop as Thr161 in the cdc2 protein.     

The Order of Exercise during Concurrent Training for Rehabilitation Does Not Alter Acute Genetic Expression,Mitochondrial Enzyme Activity or Improvements in Muscle Function

Concurrent exercise combines different modes of exercise (e.g., aerobic and resistance) into one training protocol, providing stimuli meant to increase muscle strength, aerobic capacity and mass. As disuse is associated with decrements in strength, aerobic capacity and muscle size concurrent training is an attractive modality for rehabilitation. However, interference between the signaling pathways may result in preferential improvements for one of the exercise modes. We recruited 18 young adults (10 ♂, 8 ♀) to determine if order of exercise mode during concurrent training would differentially affect gene expression, protein content and measures of strength and aerobic capacity after 2 weeks of knee-brace induced disuse. Concurrent exercise sessions were performed 3x/week for 6 weeks at gradually increasing intensities either with endurance exercise preceding (END>RES) or following (RES>END) resistance exercise. Biopsies were collected from the vastus lateralis before, 3 h after the first exercise bout and 48 h after the end of training. Concurrent exercise altered the expression of genes involved in mitochondrial biogenesis (PGC-1α, PRC, PPARγ), hypertrophy (PGC-1α4, REDD2, Rheb) and atrophy (MuRF-1, Runx1), increased electron transport chain complex protein content, citrate synthase and mitochondrial cytochrome c oxidase enzyme activity, muscle mass, maximum isometric strength and VO_2peak. However, the order in which exercise was completed (END>RES or RES>END) only affected the protein content of mitochondrial complex II subunit. In conclusion, concurrent exercise training is an effective modality for the rehabilitation of the loss of skeletal muscle mass, maximum strength, and peak aerobic capacity resulting from disuse, regardless of the order in which the modes of exercise are performed.     

Effect of high-intensity exercise and high-fat diet on lipid metabolism in the liver of rats

[Purpose]

This study investigated the effects of high-intensity exercise (Ex) and high dietary fat intake on lipid metabolism in the liver of rats.

[Methods]

Male Sprague-Dawley rats were randomly assigned to one of the four groups (n=10 per group) that were maintained on a normal diet (ND) or high-fat diet (HFD) consisting of 30% fat (w/w), with or without exercise on a treadmill at 30 m/min and 8% grade) for 4 weeks (i.e., ND, ND+Ex, HFD, and HFD+Ex groups).

[Results]

Body weight (p<.001), total plasma cholesterol (TC) (p<.001), triglyceride (TG) (p<.05), and liver TG levels (p<.05) were increased in the HFD group relative to the ND groups, and serum glucose (p<.05), insulin (p<.05), homeostatic model assessment of insulin resistance (HOMA-IR) (p<.01), and liver TG levels (p<.01) were also higher in the HFD group compared to the ND+Ex group. Plasma free fatty acid was elevated in the HFD+Ex group compared to the HFD group (p<.01). With the exception of acetyl coenzyme A carboxylase, the expression of lipid metabolism-related genes in the liver was altered in the Ex groups compared to the control group (p<.05), with genes involved in lipolysis specifically up regulated in the HFD+Ex group compared to the other groups.

[Conclusion]

Vigorous exercise may increase glucose utilization and fat oxidation by activating genes in the liver that are associated with lipid metabolism compared to that in animals consuming a HFD without exercise. Therefore, high intensity exercise can be considered to counter the adverse effects of high dietary fat intake.     

Role of Glu318 at the putative distal site in the catalytic function of cytochrome P450d.

Most microsomal P450s have a conserved "threonine cluster" composed of three Thrs (Thr319, Thr321, Thr322 for P450d) at a putative distal site. An ionic amino acid at 318 is also well conserved as Glu or Asp for most P450s. To understand the role of these conserved polar amino acids at the putative distal site in the catalytic function of microsomal P450, we studied how mutations at this site of P450d influence the activation of molecular oxygen in the reconstituted system. Catalytic activity (0.02 min-1) toward 7-ethoxycoumarin of the Glu318Ala mutant of P450d was just 6% of that (0.33 min-1) of the wild type, while those of Glu318Asp, Thr319Ala, and Thr322Ala were comparable to or even higher than that of the wild type. Consumption rates of O2 and formation rates of H2O2 of those mutants varied in accord with the catalytic activities. Especially, the efficiency (0.5%) of incorporated oxygen atom to the substrate versus produced H2O2 for the Glu318Ala mutant was much lower than that (3.7%) of the wild type, while that (58.8%) for the mutant Glu318Asp was 16-fold higher than that of the wild type. In addition, the autoxidation [Fe(II)---- Fe(III)] rate (0.074 s-1) of the Glu318Ala mutant was much lower than those (0.374-0.803 s-1) of the wild type and other mutants. Thus, we strongly suggest that Glu318 plays an important role in the catalytic function toward 7-ethoxycoumarin of microsomal P450d.     

Circulating Adipocyte Fatty Acid Binding Protein (FABP4) Levels Are Associated with Irisin in the Middle-Aged General Chinese Population

Background

Adipocyte fatty acid binding protein (FABP4) has been recently characterized as an adipokine that is closely associated with obesity and metabolic syndrome. Irisin, a novel myokine, activates thermogenesis by increasing the transformation of white adipocytes to brown, and it has improved glucose homeostasis in animal models. In this study, we aimed to explore the relationship between serum FABP4 and irisin in middle-aged Chinese subjects.

Methods

A total of 111 normal residents (56 men and 55 women) of Fengxian District who were 40 to 60 years of age were recruited. Circulating FABP4 and irisin were determined by enzyme-linked immunosorbent assay. Anthropometric parameters, oral glucose tolerance test results, hemoglobin A1C (HbA1C), blood lipids, homeostasis model assessment of insulin resistance, homeostasis model assessment-β and body fat composition were also determined.

Results

All participants were categorized by FABP4 tertiles. There were significant differences in blood pressure, body fat percentage, 2-h plasma glucose, and skeletal muscle mass among the three groups (P<0.05). Furthermore, FABP4 levels in the women were significantly higher than in the men (P<0.05). However, there was no sexual dimorphism in serum irisin (P>0.05). To exclude the effect of sex difference, partial correlations analysis showed that FABP4 was positively correlated with diastolic blood pressure (P<0.05) and body fat percentage (P<0.05) negatively correlated with skeletal muscle mass (P<0.05) and irisin (P<0.05), while irisin was positively correlated with HbA1c (P<0.05) and negatively correlated with creatinine (P<0.05). Multivariate regression analysis demonstrated that serum FABP4 was independently associated with skeletal muscle mass (P<0.001), diastolic blood pressure (P<0.05) and irisin (P<0.05) after adjustment for age, body mass index, body fat percentage, total cholesterol and HbA1C.

Conclusions

Elevated FABP4 levels increase the risks of obesity-related metabolic disorders and hypertension. Serum irisin might exert antagonistic effects on FABP4 in the middle-aged Chinese population.     

Serum Liver Fatty Acid Binding Protein Levels Correlate Positively with Obesity and Insulin Resistance in Chinese Young Adults

Background

Liver fatty acid–binding protein (FABP1) plays an inconclusive role in adiposity. We investigated the association of serum FABP1 levels with obesity and insulin resistance in Chinese young people under 30 years old.

Methodology and Principal Findings

Cross-sectional analysis including 200 obese and 172 normal-weight subjects matched for age and sex, anthropometric measurements were performed and serum FABP1 and biochemical characteristics were measured. Insulin resistance was determined by homeostasis model assessment of insulin resistance (HOMA-IR) and by the insulin sensitivity index (S_i) derived from Bergman’s minimal model. FABP1 levels in obese subjects were significantly higher than those in normal-weight subjects (p<0.001) and the significance remained after adjustment for age, gender, alanine and aspartate aminotransferases (p<0.001). Serum FABP1 levels were significantly correlated with many metabolic-related parameters, with BMI and triglycerides as the independent determinants. FABP1 levels remained an independent risk factor of insulin resistance assessed by binary S_i (OR = 1.868 per SD unit, 95% CI [1.035–3.373], p = 0.038) after adjustment for age, sex, BMI, waist circumference, systolic blood pressure, serum triacylglycerol, total cholesterol, HDL- and LDL-cholesterol,. FABP1 levels were also elevated with an increasing number of components of the metabolic syndrome (p for trend <0.001). Multiple regression modeling for the MetS and its components demonstrated that hypertriglyceridemia and low HDL-cholesterol were significantly correlated to serum FABP1 levels.

Conclusions and Significance

Serum FABP1 correlates positively with obesity and insulin resistance in Chinese young adults. Our data supports the fact that FABP1 might be an important mediator participating in fatty acid metabolism and energy balance.     

Identification of protein regions involved in the interaction of human respiratory syncytial virus phosphoprotein and nucleoprotein: significance for nucleocapsid assembly and formation of cytoplasmic inclusions.

We have reported previously that the nucleoprotein (N), the phosphoprotein (P), and the 22-kDa protein of human respiratory syncytial virus (HRSV) are components of the cytoplasmic inclusion bodies observed in HEp-2-infected cells. In addition, coexpression of N and P was sufficient to induce the formation of N-P complexes detectable by either coimmunoprecipitation with anti-P antibodies or generation of cytoplasmic inclusions. We now report the identification of protein regions required for these interactions. Deletion mutant analysis of the P protein gene indicated that its C-terminal end was essential for interacting with N. This conclusion was strengthened by the finding that an anti-P monoclonal antibody (021/12P), reacting with a 21-residue P protein C-terminal peptide, apparently displaced N from N-P complexes. The same effect was observed with high concentrations of the C-terminal peptide. However, sequence requirements for the P protein C-terminal end were not absolute, and mutants with the substitution Ser-237-->Ala or Ser-237-->Thr were as efficient as the wild type in interacting with N. In addition, P and N proteins from strains of different HRSV antigenic groups, with sequence differences in the P protein C-terminal end, were able to coimmunoprecipitate and formed cytoplasmic inclusions. Deletion mutant analysis of the N gene indicated that large segments of this polypeptide were required for interacting with P. The relevance of these interactions for HRSV is discussed in comparison with those of analogous proteins from related viruses.     

Association between functional FABP2 promoter haplotype and type 2 diabetes.

Fatty acid-binding protein 2 (FABP2) is a cytosolic protein expressed exclusively in epithelial cells of the small intestine. Some, albeit not conclusive, evidence indicates that the Thr-allele of FABP2 Ala54Thr polymorphism is associated with type 2 diabetes. More recently, common FABP2 promoter polymorphisms have shown association with postprandial increase of triglycerides, body composition and plasma lipid levels. Therefore, we reasoned that variants in the FABP2 promoter may also predispose to type 2 diabetes mellitus. In our Caucasian study population, we found three SNPs and three insertion-deletion polymorphisms that are in complete linkage disequilibrium defining promoter haplotype A and B within 1kb 5' of the FABP2 initiation codon. Haplotype calculations indicated that the FABP2 promoter and Ala54Thr variants were strongly linked. Functional analysis of promoter fragments demonstrated that haplotype difference is caused by polymorphisms within 260 bp downstream of the FABP2 initiation codon. Using a prospective case-control study nested within the EPIC-Potsdam cohort of 192 incident type 2 diabetes cases and 384 sex-/age-matched controls, male subjects carrying the FABP2 haplotype B allele showed significantly decreased risk of type 2 diabetes when adjusted for BMI (OR = 0.50, 95 % CI = 0.28 - 0.87, p < 0.05) and additional covariates (OR = 0.42, 95 % CI 0.22 - 0.81, p < 0.01). Further adjustment for the Ala54Thr polymorphism revealed an OR of 0.18 (95 % CI 0.06 - 0.49, p < 0.001). Similarly, Ala/Ala homozygote males carrying the promoter haplotype B had decreased risk (0.33, 0.11 - 0.94, p < 0.05) of type 2 diabetes after stratification for the Ala54Thr polymorphism. FABP2 promoter haplotypes or genotype combinations defined by the promoter and Ala54Thr polymorphism were not associated with BMI, body fat, leptin, HbA (1c), total cholesterol or HDL. In conclusion, our findings suggest that the functional FABP2 promoter haplotype may contribute to type 2 diabetes in a sex-specific manner.     

The interaction effects of aerobic exercise training and vitamin D supplementation on plasma lipid profiles and insulin resistance in ovariectomized rats

Purpose

The purpose of this study was to determine the interaction effects of aerobic exercise training and vitamin D supplementation on indices of obesity and plasma lipid profiles in ovariectomized (OVX) rats.

Methods

Forty female Wistar rats were divided into 5 groups: aerobic training (3 days/week for 8 weeks; AT; n = 8), aerobic training and vitamin D supplementation (OVX + AT + Vit D; n = 8), vitamin D supplementation (OVX + Vit D; n = 8), ovariectomized control (OVX + C, n = 8) and SHAM (n = 8). After blood sampling, visceral fat was taken from the abdominal cavity and weighed immediately. Data was statistically analyzed by One-way ANOVA and Repeated measure ANOVA tests with a 0.05 significance level.

Results

Body weight, visceral fat, BMI and food intake decreased significantly in OVX + AT + Vit D (P < 0.001); whereas these variables increased significantly in OVX + C (P < 0.001) and SHAM (P < 0.023) groups. At the end of two-months of follow-up, we observed significant differences in TC, TG, HDL-C, LDL-C, glucose, insulin, and HOMA-IR in all groups.

Conclusion

It seems that aerobic training with vitamin D, due to the involvement of muscle mass and exposure to dynamic pressure on the bones and muscles, increased energy expenditure, stimulated insulin exudation and glucose homeostasis, decreased insulin resistance and improved the lipid profile in ovariectomized rats.     

The Effects of Acute Exercise and Exercise Training on Plasma Homocysteine: A Meta-Analysis

Background

Although studies have demonstrated that physical exercise alters homocysteine levels in the blood, meta-analyses of the effects of acute exercise and exercise training on homocysteine blood concentration have not been performed, especially regarding the duration and intensity of exercise, which could affect homocysteine levels differently.

Objective

The aim of this meta-analysis was to ascertain the effects of acute exercise and exercise training on homocysteine levels in the blood.

Method

A review was conducted according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses using the online databases PubMed, SPORTDiscus, and SciELO to identify relevant studies published through June 2015. Review Manager was used to calculate the effect size of acute exercise and exercise training using the change in Hcy plasmaserum concentration from baseline to post-acute exercise and trained vs. sedentary control groups, respectively. Weighted mean differences were calculated using random effect models.

Results

Given the abundance of studies, acute exercise trials were divided into two subgroups according to exercise volume and intensity, whereas the effects of exercise training were analyzed together. Overall, 22 studies with a total of 520 participants indicated increased plasma homocysteine concentration after acute exercise (1.18 μmol/L, 95% CI: 0.71 to 1.65, p < .01). Results of a subgroup analysis indicated that either long-term exercise of low-to-moderate intensity (1.39 μmol/L, 95% CI: 0.9 to 1.89, p < .01) or short-term exercise of high intensity (0.83 μmol/L, 95% CI: 0.19 to 1.40, p < .01) elevated homocysteine levels in the blood. Increased homocysteine induced by exercise was significantly associated with volume of exercise, but not intensity. By contrast, resistance training reduced plasma homocysteine concentration (-1.53 μmol/L, 95% CI: -2.77 to -0.28, p = .02), though aerobic training did not. The cumulative results of the seven studies with a total of 230 participants in exercise training analysis did not demonstrate a significant impact on homocysteine levels in the blood (-0.56 μmol/L, 95% CI: -1.61 to 0.50, p = .23).

Conclusions

Current evidence demonstrates that acute exercise increases homocysteine levels in the blood independent of exercise duration and intensity. Resistance, but not aerobic training decreases plasma homocysteine levels.     

The role of helix VIII in the lactose permease of Escherichia coli: II. Site-directed sulfhydryl modification.

Cys-scanning mutagenesis of putative transmembrane helix VIII in the lactose permease of Escherichia coli (Frillingos S. Ujwal ML, Sun J, Kaback HR, 1997, Protein Sci 6:431-437) indicates that, although helix VIII contains only one irreplaceable residue (Glu 269), one face is important for active lactose transport. In this study, the rate of inactivation of each N-ethylmaleimide (NEM)-sensitive mutant is examined in the absence or presence of beta, D-galactopyranosyl 1-thio-beta,D-galactopyranoside (TDG). Remarkably, the analogue affords protection against inactivation with mutants Val 264-->Cys, Gly 268-->Cys, and Asn 272-->Cys, and alkylation of these single-Cys mutants in right-side-out membrane vesicles with [14C]NEM is attenuated by TDG. In contrast, alkylation of Thr 265-->Cys, which borders the three residues that are protected by TDG, is enhanced markedly by the analogue. Furthermore, NEM-labeling in the presence of the impermeant thiol reagent methanethiosulfonate ethylsulfonate demonstrates that ligand enhances the accessibility of position 265 to solvent. Finally, no significant alteration in NEM reactivity is observed for mutant Gly 262-->Cys, Glu 269-->Cys, Ala 273-->Cys, Met 276-->Cys, Phe 277-->Cys, or Ala 279-->Cys. The findings indicate that a portion of one face of helix VIII (Val 264, Gly 268, and Asn 272), which is in close proximity to Cys 148 (helix V), interacts with substrate, whereas another position bordering these residues (Thr 265) is altered by a ligand-induced conformational change.     

The rs225017 Polymorphism in the 3′UTR of the Human DIO2 Gene Is Associated with Increased Insulin Resistance

The Thr92Ala (rs225014) polymorphism in the type 2 deiodinase (DIO2) gene has been associated with insulin resistance (IR) and decreased enzyme activity in human tissues but kinetic studies failed to detect changes in the mutant enzyme, suggesting that this variant might be a marker of abnormal DIO2 expression. Thus, we aimed to investigate whether other DIO2 polymorphisms, individually or in combination with the Thr92Ala, may contribute to IR. The entire coding-region of DIO2 gene was sequenced in 12 patients with type 2 diabetes mellitus (T2DM). Potentially informative variants were evaluated in 1077 T2DM patients and 516 nondiabetic subjects. IR was evaluated using the homeostasis model assessment (HOMA-IR) index. DIO2 gene sequencing revealed no new mutation but 5 previously described single nucleotide polymorphisms (SNPs). We observed that all T2DM patients displaying high HOMA-IR index (n = 6) were homozygous for the rs225017 (T/A) polymorphism. Further analysis showed that the median fasting plasma insulin and HOMA-IR of T2DM patients carrying the T/T genotype were higher than in patients carrying the A allele (P = 0.013 and P = 0.002, respectively). These associations were magnified in the presence of the Ala92Ala genotype of the Thr92Ala polymorphism. Moreover, the rs225017 and the Thr92Ala polymorphisms were in partial linkage disequilibrium (|D′| = 0.811; r ² = 0.365). In conclusion, the rs225017 polymorphism is associated with greater IR in T2DM and it seems to interact with the Thr92Ala polymorphism in the modulation of IR.