Remorin, a uronide binding protein with physical properties similar to the tobacco mosaic virus movement protein

The extracellular pectic matrix is a rich source of oligogalacturonic acid (OGA), one of the most abundant polymeric regulatory molecules on the earth's surface. OGAs regulate the expression of a variety of defense genes and have also been implicated in developmental processes. Little is known about how cells perceive OGAs and we have been attempting to characterise proteins capable of interacting with these molecules. We recently succeeded in cloning a cDNA encoding a small OGA-binding protein, remorin. OGA-binding to remorin is not highly specific, the protein binds homogalacturonides, complex pectic polymers and the animal polyuronide heparin. This lack of specificity contrasts with that often observed with classical receptors and the function of remorin remains to be discovered. Remorin copurifies with the plasma membrane but is a very hydrophilic polypeptide. Its behavior during cell fractionation, as well as a number of properties including the OGA-stimulated in vitro phosphorylation and preliminary localization studies, all suggest parallels with some viral movement proteins. Some of these comparisons will be presented. Experiments to directly test for the possible role of this protein in cell-to-cell signalling are in progress. EEF is supported by FNRS grant 31-3672-92.

Influence of physical activity and dietary habits on lipid profile, blood pressure and BMI in subjects with metabolic syndrome

BACKGROUND The present study was determined the influence of physical activity and dietary habits on lipid profile, blood pressure (BP) and body mass index (BMI) in subjects with metabolic syndrome (MS). AIMS Identify the relationship between physical activity and proper nutrition and the probability of suffering from myocardial infarction (MI). METHODS Hundred chronically ill with MS who were active and followed a healthy diet were classified as compliant, while the remaining subjects were classified as non-compliant. RESULTS The compliant subjects show lower BMI values (30.8±4.9 vs 32.5±4.6), as well as lower levels of triacylglycerol (130.4±48.2 vs 242.1±90.1), total cholesterol (193.5±39 vs 220.2±52.3) and low-density lipoprotein cholesterol (105.2±38.3 vs 139.2±45). They show higher values in terms of high-density lipoprotein cholesterol levels (62.2±20.1 vs 36.6±15.3), with statistically significant differences. In terms of both systolic and diastolic pressure, no differences were revealed between the groups; however, those who maintain proper dietary habits show lower systolic blood pressure levels than the inactive subjects. The probability of suffering from MI greatly increases among the group of non-compliant subjects. CONCLUSIONS Our results demonstrate how performing aerobic physical activity and following an individualized, Mediterranean diet significantly reduces MS indicators and the chances of suffering from MI.

Contribution of physical education to overall physical activity.

For many children, physical activity (PA) during physical education (PE) lessons provides an important opportunity for being physically active. Although PA during PE has been shown to be low, little is known about the contribution of PA during PE to overall PA. The aim was therefore to assess children's PA during PE and to determine the contribution of PE to overall PA with special focus on overweight children. Accelerometer measurements were done in 676 children (9.3 ± 2.1 years) over 4-7 days in 59 randomly selected classes. Moderate-and-vigorous PA (MVPA; ≥ 2000 counts/min) during PE (MVPA(PE) ), overall MVPA per day (MVPA(DAY) ), and a comparison of days with and without PE were calculated by a regression model with gender, grade, and weight status (normal vs overweight) as fixed factors and class as a random factor. Children spent 32.8 ± 15.1% of PE time in MVPA. Weight status was not associated to MVPA(PE) . MVPA(PE) accounted for 16.8 ± 8.5% of MVPA(DAY) , and 17.5 ± 8.2% in overweight children. All children were more active on days with PE than on days without PE (differences: 16.1 ± 29.0 min of MVPA(DAY) ; P ≤ 0.001; 13.7 ± 28.0 min for overweight children). Although MVPA(PE) was low, PE played a considerable role in providing PA and was not compensated by reducing extracurricular MVPA.

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.

Interaction between dietary lipids an physical inactivity on insulin sensitivity and on intramyocellular lipids in healthy men

Résumé Interaction entre les lipides alimentaires et l'inactivité physique sur la sensibilité à l'insuline et les lipides intramyocellulaires chez le sujet masculin en bonne santé Ces deux dernières décennies, l'incidence de la résistance à l'insuline n'a cessé de progresser dans les pays industrialisés. Un grand nombre de travaux suggèrent que ce trouble métabolique joue un rôle important dans la pathogenèse de maladies propres au monde industrialisé, telles que le diabète, l'hypertension et les maladies cardiovasculaires. Malgré de nombreuses études, les mécanismes à l'origine de la résistance à l'insuline restent encore incomplètement élucidés. En plus d'une composante génétique, de nombreux facteurs environnementaux semblent impliqués parmi ces derniers, nous nous sommes intéressés à l'effet d'une alimentation riche en graisses associée à une période d'inactivité physique de courte durée. Nous nous sommes également penchés sur la corrélation décrite entre la résistance à l'insuline et la concentration de graisses présentes à l'intérieur des cellules musculaires squelettiques, appelées lipides intramyocellulaires. Pour ce faire, 8 volontaires masculins ont été étudiés à deux occasions. Après deux jours de diète équilibrée associée à une activité physique, les participants étaient confinés au lit strict pour 60 heures et devaient manger une alimentation soit riche en graisses saturées soit riche en hydrates de carbones. Pour évaluer l'effet de l'alimentation seule, 6 des 8 volontaires ont été réétudiés après deux jours de diète équilibrée suivie par 60 heures d'alimentation riche en graisses saturées associées à une activité physique contrôlée. Nous avons estimé la sensibilité à l'insuline par la technique du clamp hyperinsulinémique euglycémique alors que la concentration de lipides intramyocellulaires a été déterminée par spectroscopie par résonance magnétique. Après 60 heures d'inactivité physique associée à une alimentation riche en lipides, nous avons observé une diminution de l'utilisation de glucose dépendante de l'insuline (-24±6%; p<0.05), alors qu'aucune modification significative de ce même paramètre n'a été constatée lorsque l'inactivité physique était associée à une alimentation riche en hydrates de carbones (+19±10%). Ces deux conditions se sont accompagnées d'une augmentation des lipides intramyocellulaires (+32±7% et +17±8% respectivement). Bien que l'augmentation des lipides intramyocellulaires observée après 60 heures d'une alimentation riche en graisses saturées associée à une activité physique modérée fût d'une ampleur similaire à celle de la condition associant une alimentation riche en graisses et inactivité physique, l'utilisation de glucose induite par l'insuline n'a pas été modifiée de manière significative (-7±9%) Ces résultats indiquent que l'inactivité physique et une alimentation riche en graisses saturées semblent interagir, induisant une diminution de la sensibilité à l'insuline globale. La concentration de lipides intramyocellulaires a été influencée par les lipides issus de l'alimentation et l'inactivité physique, sans être toutefois corrélée à la résistance à l'insuline. Abstract OBJECTIVE - To assess the effect of a possible interaction between dietary fat and physical inactivity on whole-body insulin sensitivity and intramyocellular lipids (IMCLs). RESEARCH DESIGN AND METHODS - Eight healthy male volunteers were studied on two occasions. After 2 days of an equilibrated diet and moderate physical activity, participants remained inactive (bed rest) for 60 h and consumed either a high-saturated fat (45% fat, of which ~60% was saturated fat [BR-HF]) or a high-carbohydrate (70% carbohydrate [BR-HCHO]) diet. To evaluate the effect of a high-fat diet alone, six of the eight volunteers were restudied after a 2-day equilibrated diet followed by 60 h on a high-saturated fat diet and controlled physical activity (PA-HF). Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp and IMCL concentrations by H-magnetic resonance spectroscopy. RESULTS - Insulin-mediated glucose disposal was decreased by BR-HF condition (-24 ± 6%, P < 0.05) but did not change with BR-HCHO ( + 19 ± 10%, NS). BR-HF and BR-HCHO increased IMCL levels (+32 ± 7%, P < 0.05 and +17 ± 8%, P < 0.0011, respectively). Although the increase in IMCL levels with PA-HF (+31 ± 19%, P = 0.12) was similar to that during BR-HF, insulin-mediated glucose disposal ( -7 ± 9%, NS) was not decreased. CONCLUSIONS - These data indicate that physical inactivity and a high-saturated fat diet may interact to reduce whole-body insulin sensitivity. IMCL content was influenced by dietary lipid and physical inactivity but was not directly associated with insulin resistance.

The forgotten face of regular physical exercise: a 'natural' anti-atherogenic activity.

Humans are not programmed to be inactive. The combination of both accelerated sedentary lifestyle and constant food availability disturbs ancient metabolic processes leading to excessive storage of energy in tissue, dyslipidaemia and insulin resistance. As a consequence, the prevalence of Type 2 diabetes, obesity and the metabolic syndrome has increased significantly over the last 30 years. A low level of physical activity and decreased daily energy expenditure contribute to the increased risk of cardiovascular morbidity and mortality following atherosclerotic vascular damage. Physical inactivity leads to the accumulation of visceral fat and consequently the activation of the oxidative stress/inflammation cascade, which promotes the development of atherosclerosis. Considering physical activity as a 'natural' programmed state, it is assumed that it possesses atheroprotective properties. Exercise prevents plaque development and induces the regression of coronary stenosis. Furthermore, experimental studies have revealed that exercise prevents the conversion of plaques into a vulnerable phenotype, thus preventing the appearance of fatal lesions. Exercise promotes atheroprotection possibly by reducing or preventing oxidative stress and inflammation through at least two distinct pathways. Exercise, through laminar shear stress activation, down-regulates endothelial AT1R (angiotensin II type 1 receptor) expression, leading to decreases in NADPH oxidase activity and superoxide anion production, which in turn decreases ROS (reactive oxygen species) generation, and preserves endothelial NO bioavailability and its protective anti-atherogenic effects. Contracting skeletal muscle now emerges as a new organ that releases anti-inflammatory cytokines, such as IL-6 (interleukin-6). IL-6 inhibits TNF-α (tumour necrosis factor-α) production in adipose tissue and macrophages. The down-regulation of TNF-α induced by skeletal-muscle-derived IL-6 may also participate in mediating the atheroprotective effect of physical activity.

Physical activity, bodyweight, health and fear of negative evaluation in primary school children.

Fear of negative evaluation (FNE) is regarded as being the core feature of social anxiety. The present study examined how FNE is associated with physical activity (PA), body mass index (BMI) and perceived physical health (PPH) in children. Data were collected in a sample of 502 primary school children in first and fifth grades taking part in a randomized-controlled trial ("Kinder-Sportstudie KISS") aimed at increasing PA and health. PA was assessed by accelerometry over 7 days, PPH by the Child Health Questionnaire and FNE by the Social Anxiety Scale for Children--Revised. BMI z-scores were calculated based on Swiss norms. Cross-sectional analyses indicated that children high in FNE exercised less, reported lower levels of PPH and had higher BMI z-scores (P&lt;0.01). Using mixed linear models, the school-based PA intervention did not manage to reduce FNE scores. Overweight children demonstrated a greater increase in FNE (P&lt;0.05) indicating that enhanced weight may be a risk factor for FNE. In conclusion, the associations among high FNE, low PA and increased BMI should be considered when promoting an active lifestyle in children.

Physical activity and energy expenditure in haemodialysis patients: an international survey.

BACKGROUND: The assessment of physical activity and energy expenditure is relevant to the care of maintenance haemodialysis (MHD) patients. In the current study, we aimed to evaluate measurements of physical activity and energy expenditure in MHD patients from different centres and countries and explored the predictors of physical activity in these patients.¦METHODS: In this cross-sectional multicentre study, 134 MHD patients from four countries (France, Switzerland, Sweden and Brazil) were included. The physical activity was evaluated for 5.0 ± 1.4 days (mean ± SD) by a multisensory device (SenseWear Armband) and comprised the assessment of number of steps per day, activity-related energy expenditure (activity-related EE) and physical activity level (PAL).¦RESULTS: The number of steps per day, activity-related EE and PAL from the MHD patients were compatible with a sedentary lifestyle. In addition, all parameters were significantly lower in dialysis days when compared to non-dialysis days (P < 0.001). The multivariate regression analysis revealed that diabetes and higher body mass index (BMI) predicted a lower PAL and older age and diabetes predicted a reduced number of steps.¦CONCLUSIONS: The physical activity parameters of MHD patients were compatible with a sedentary lifestyle. This inactivity was worsened by aging, diabetes and higher BMI. Our results indicate that MHD patients should be encouraged by the health care team to increase their physical activity.

Assessment of Physical Activity and Energy Expenditure by GPS Combined With Accelerometry in Real-Life Conditions.

Background: Physical activity (PA) and related energy expenditure (EE) is often assessed by means of a single technique. Because of inherent limitations, single techniques may not allow for an accurate assessment both PA and related EE. The aim of this study was to develop a model to accurately assess common PA types and durations and thus EE in free-living conditions, combining data from global positioning system (GPS) and 2 accelerometers. Methods: Forty-one volunteers participated in the study. First, a model was developed and adjusted to measured EE with a first group of subjects (Protocol I, n = 12) who performed 6 structured and supervised PA. Then, the model was validated over 2 experimental phases with 2 groups (n = 12 and n = 17) performing scheduled (Protocol I) and spontaneous common activities in real-life condition (Protocol II). Predicted EE was compared with actual EE as measured by portable indirect calorimetry. Results: In protocol I, performed PA types could be recognized with little error. The duration of each PA type could be predicted with an accuracy below 1 minute. Measured and predicted EE were strongly associated (r = .97, P < .001). Conclusion: Combining GPS and 2 accelerometers allows for an accurate assessment of PA and EE in free-living situations.

Moderate-Vigorous Physical Activity across Body Mass Index in Females: Moderating Effect of Endocannabinoids and Temperament.

BACKGROUND Endocannabinoids and temperament traits have been linked to both physical activity and body mass index (BMI) however no study has explored how these factors interact in females. The aims of this cross-sectional study were to 1) examine differences among distinct BMI groups on daytime physical activity and time spent in moderate-vigorous physical activity (MVPA), temperament traits and plasma endocannabinoid concentrations; and 2) explore the association and interaction between MVPA, temperament, endocannabinoids and BMI. METHODS Physical activity was measured with the wrist-worn accelerometer Actiwatch AW7, in a sample of 189 female participants (43 morbid obese, 30 obese, and 116 healthy-weight controls). The Temperament and Character Inventory-Revised questionnaire was used to assess personality traits. BMI was calculated by bioelectrical impedance analysis via the TANITA digital scale. Blood analyses were conducted to measure levels of endocannabinoids and endocannabinoid-related compounds. Path-analysis was performed to examine the association between predictive variables and MVPA. RESULTS Obese groups showed lower MVPA and dysfunctional temperament traits compared to healthy-weight controls. Plasma concentrations of 2-arachidonoylglyceryl (2-AG) were greater in obese groups. Path-analysis identified a direct effect between greater MVPA and low BMI (b = -0.13, p = .039) and high MVPA levels were associated with elevated anandamide (AEA) levels (b = 0.16, p = .049) and N-oleylethanolamide (OEA) levels (b = 0.22, p = .004), as well as high Novelty seeking (b = 0.18, p<.001) and low Harm avoidance (b = -0.16, p<.001). CONCLUSIONS Obese individuals showed a distinct temperament profile and circulating endocannabinoids compared to controls. Temperament and endocannabinoids may act as moderators of the low MVPA in obesity.

The influence of individual, social and physical environment factors on physical activity in the adult population in Andalusia, Spain.

A person's physical and social environment is considered as an influencing factor in terms of rates of engagement in physical activity. This study analyses the influence of socio-demographic, physical and social environmental factors on physical activity reported in the adult population in Andalusia. This is a cross-sectional study using data collected in the Andalusia Health Survey in 1999 and 2003. In addition to the influence of the individual's characteristics, if there are no green spaces in the neighbourhood it is less likely that men and women will take exercise (OR = 1.26; 95% CI = 1.13, 1.41). Likewise, a higher local illiteracy rate also has a negative influence on exercise habits in men (OR = 1.39; 95% CI = 1.21, 1.59) and in women (OR = 1.22; 95% CI = 1.07, 1.40). Physical activity is influenced by individuals' characteristics as well as by their social and physical environment, the most disadvantaged groups are less likely to engage in physical activity.