Epithelial transport and deamidation of gliadin peptides: a role for coeliac disease patient immunoglobulin A.

In coeliac disease, the intake of dietary gluten induces small-bowel mucosal damage and the production of immunoglobulin (Ig)A class autoantibodies against transglutaminase 2 (TG2). We examined the effect of coeliac patient IgA on the apical-to-basal passage of gluten-derived gliadin peptides p31-43 and p57-68 in intestinal epithelial cells. We demonstrate that coeliac IgA enhances the passage of gliadin peptides, which could be abolished by inhibition of TG2 enzymatic activity. Moreover, we also found that both the apical and the basal cell culture media containing the immunogenic gliadin peptides were able to induce the proliferation of deamidation-dependent coeliac patient-derived T cells even in the absence of exogenous TG2. Our results suggest that coeliac patient IgA could play a role in the transepithelial passage of gliadin peptides, a process during which they might be deamidated.

Degradation of coeliac disease-inducing rye secalin by germinating cereal enzymes: diminishing toxic effects in intestinal epithelial cells.

Currently the only treatment for coeliac disease is a lifelong gluten-free diet excluding food products containing wheat, rye and barley. There is, however, only scarce evidence as to harmful effects of rye in coeliac disease. To confirm the assumption that rye should be excluded from the coeliac patient's diet, we now sought to establish whether rye secalin activates toxic reactions in vitro in intestinal epithelial cell models as extensively as wheat gliadin. Further, we investigated the efficacy of germinating cereal enzymes from oat, wheat and barley to hydrolyse secalin into short fragments and whether secalin-induced harmful effects can be reduced by such pretreatment. In the current study, secalin elicited toxic reactions in intestinal Caco-2 epithelial cells similarly to gliadin: it induced epithelial cell layer permeability, tight junctional protein occludin and ZO-1 distortion and actin reorganization. In high-performance liquid chromatography and mass spectroscopy (HPLC-MS), germinating barley enzymes provided the most efficient degradation of secalin and gliadin peptides and was thus selected for further in vitro analysis. After germinating barley enzyme pretreatment, all toxic reactions induced by secalin were ameliorated. We conclude that germinating enzymes from barley are particularly efficient in the degradation of rye secalin. In future, these enzymes might be utilized as a novel medical treatment for coeliac disease or in food processing in order to develop high-quality coeliac-safe food products.

Spatial association of prolyl oligopeptidase, inositol 1,4,5-triphosphate type 1 receptor, substance P and its neurokinin-1 receptor in the rat brain: an immunohistochemical colocalization study.

Prolyl oligopeptidase (POP) is a serine endopeptidase which hydrolyzes proline-containing peptides shorter than 30 amino acids. It has been suggested that POP is associated with cognitive functions, possibly via the cleavage of neuropeptides such as substance P (SP). Recently, several studies have also linked POP to the inositol 1,4,5-triphosphate (IP(3)) signaling. However, the neuroanatomical interactions between these substances are not known. We used double-labeled immunofluorescence to determine the POP colocalization with SP, SP receptor (neurokinin-1 receptor, NK-1R) and IP(3) type 1 receptor (IP(3)R1) in the rat brain. Furthermore, since striatal and cortical GABAergic neurons are involved in SP neurotransmission, we studied the coexpression of POP, SP and GABA by triple-labeled immunofluorescence. POP was moderately present in IP(3)R1-containing cells in cortex; the colocalization was particularly high in the thalamus, hippocampal CA1 field and cerebellar Purkinje cells. Colocalization of POP with SP and NK1-receptor was infrequent throughout the brain, though some POP and SP coexpression was observed in cerebellar Purkinje cells. We also found that POP partially colocalized with SP-containing GABAergic neurons in striatum and cortex. Our findings support the view that POP is at least spatially associated with the IP(3)-signaling in the thalamus, hippocampus and cerebellar Purkinje cells. This might point to a role for POP in the regulation of long-term potentiation and/or depression. Moreover, the low degree of colocalization of POP, SP and its NK-1R suggests that a transport system is needed either for POP or SP to make hydrolysis possible and that POP may act both intra- and extracellularly.

Live probiotic Bifidobacterium lactis bacteria inhibit the toxic effects induced by wheat gliadin in epithelial cell culture.

Wheat gliadin induces severe intestinal symptoms and small-bowel mucosal damage in coeliac disease patients. At present, the only effective treatment for the disease is a strict life-long gluten-free diet. In this study we investigated whether probiotics Lactobacillus fermentum or Bifidobacterium lactis can inhibit the toxic effects of gliadin in intestinal cell culture conditions. The ability of live probiotics to inhibit peptic-tryptic digested gliadin-induced damage to human colon cells Caco-2 was evaluated by measuring epithelial permeability by transepithelial resistance, actin cytoskeleton arrangements by the extent of membrane ruffling and expression of tight junctional protein ZO-1. B. lactis inhibited the gliadin-induced increase dose-dependently in epithelial permeability, higher concentrations completely abolishing the gliadin-induced decrease in transepithelial resistance. The same bacterial strain also inhibited the formation of membrane ruffles in Caco-2 cells induced by gliadin administration. Furthermore, it also protected the tight junctions of Caco-2 cells against the effects of gliadin, as evinced by the pattern of ZO-1 expression. We conclude thus that live B. lactis bacteria can counteract directly the harmful effects exerted by coeliac-toxic gliadin and would clearly warrant further studies of its potential as a novel dietary supplement in the treatment of coeliac disease.

On the role of prolyl oligopeptidase in health and disease.

Prolyl oligopeptidase (POP) is a serine peptidase which digests small peptide-like hormones, neuroactive peptides, and various cellular factors. Therefore, this peptidase has been implicated in many physiological processes as well as in some psychiatric disorders, most probably through interference in inositol cycle. Intense research has been performed to elucidate, on the one hand, the basic structure, ligand binding, and kinetic properties of POP, and on the other, the pharmacology of its inhibitors. There is fairly strong evidence of in vivo importance of POP on substance P, arginine vasopressin, thyroliberin and gonadoliberin metabolism. However, information about the biological relevance of POP is not yet conclusive. Evidence regarding the physiological role of POP is lacking, which is surprising considering that peptidase inhibitors have been exploited for drug development, some of which are currently in clinical trials as memory enhancers for the aged and in a variety of neurological disorders. Here we review the recent progress on POP research and evaluate the relevance of the peptidase in the metabolism of various neuropeptides. The recognition of novel forms and relatives of POP may improve our understanding of how this family of proteins functions in normal and in neuropathological conditions.

Brain prolyl oligopeptidase activity is associated with neuronal damage rather than beta-amyloid accumulation.

Prolyl oligopeptidase (POP) have been suggested to participate in the pathogenesis of Alzheimer's disease (AD). In this study the activity of POP is evaluated in AD patients and in transgenic mice with substantial deposits of beta-amyloid (Abeta). In AD cases, the POP activity displayed a significant negative correlation with the scores of senile/neuritic plaques and neurofibrillary tangles but not with Abeta-load. The transgenic mice with high levels of Abeta did not have altered POP activity compared to wild type mice. Based on our results, the low POP activity in AD seems to be associated with neuronal degeneration rather than to Abeta accumulation.

Cardiovascular fitness as a predictor of mortality in men.

OBJECTIVE: To examine the relations of cardiorespiratory fitness, as measured by maximal oxygen uptake and exercise test duration at the initiation of the study, with overall, cardiovascular disease (CVD)-related, and non-CVD-related mortality. METHODS: A population-based cohort study of 1294 men with no CVD, pulmonary disease, or cancer at baseline in Kuopio and surrounding communities in eastern Finland. During an average follow-up of 10.7 years, there were 124 overall, 42 CVD-related, and 82 non-CVD-related deaths. RESULTS: The relative risk of overall death in unfit men (maximal oxygen uptake <27.6 mL/kg per minute) was 2.76 (95% confidence interval, 1.43-5.33) (P =.002), and the relative risk of CVD-related death was 3.09 (95% confidence interval, 1.10-9.56) (P =.05), compared with fit men (maximal oxygen uptake >37.1 mL/kg per minute) after adjusting for age, examination years, smoking, and alcohol consumption. The relative risk of non-CVD-related death in unfit men was almost the same magnitude as for overall death. Furthermore, adjustment for serum lipid levels, blood pressure, plasma fibrinogen level, diabetes, and fasting serum insulin level did not weaken these associations significantly. Exercise test duration also had a strong inverse relation to overall, CVD-related, and non-CVD-related mortality. Poor cardiorespiratory fitness was comparable with elevated systolic blood pressure, smoking, obesity, and diabetes in importance as a risk factor for mortality. CONCLUSIONS: Cardiorespiratory fitness had a strong, graded, inverse association with overall, CVD-related, and non-CVD-related mortality. Maximal oxygen uptake and exercise test duration represent the strongest predictors of mortality.

Relation of leisure-time physical activity and cardiorespiratory fitness to the risk of acute myocardial infarction.

BACKGROUND: Previous studies have suggested that higher levels of regular physical activity and cardiorespiratory fitness are associated with a reduced risk of coronary heart disease. We investigated the independent associations of physical activity during leisure time and maximal oxygen uptake (a measure of cardiorespiratory fitness) with the risk of acute myocardial infarction. METHODS: During the period 1984 to 1989, we performed base-line examinations in 1453 men 42 to 60 years old who did not report having cardiovascular disease or cancer. Physical activity was assessed quantitatively with a detailed questionnaire, and maximal oxygen uptake was measured directly by exercise testing. During an average follow-up of 4.9 years, 42 of the 1166 men with normal electrocardiograms at base line had a first acute myocardial infarction. RESULTS: After adjustment for age and the year of examination, the relative hazard (risk) of myocardial infarction in the third of subjects with the highest level of physical activity (> 2.2 hours per week) was 0.31 (95 percent confidence interval, 0.12 to 0.85; P = 0.02), as compared with the third with the lowest level (P = 0.04 for linear trend over all three groups). The relative hazard in the third with the highest maximal oxygen uptake (> 2.7 liters per minute) was 0.26 (95 percent confidence interval, 0.10 to 0.68; P = 0.006) (P = 0.006 for linear trend), after adjustment for age, the year and season when the examination was performed, weight, height, and the type of respiratory-gas analyzer used. After up to 17 confounding variables were controlled for, the relative hazards for the third of subjects with the highest level of physical activity (0.34; 95 percent confidence interval, 0.12 to 0.94; P = 0.04) and maximal oxygen uptake (0.35; 95 percent confidence interval, 0.13 to 0.92; P = 0.03), as compared with the values in the lowest third, were significantly (P < 0.05) less than 1.0. CONCLUSIONS: Higher levels of both leisure-time physical activity and cardiorespiratory fitness had a strong, graded, inverse association with the risk of acute myocardial infarction, supporting the idea that lower levels of physical activity and cardiorespiratory fitness are independent risk factors for coronary heart disease.

Ketoprofen 2.5% gel versus placebo gel in the treatment of acute soft tissue injuries.

A parallel, double-blind, placebo controlled and randomized study in a single center was done with ketoprofen 2.5% gel to treat acute soft tissue injuries. Patients applied the gel twice a day for seven days, corresponding to 250 mg of ketoprofen per day. Assessments were made on the third and seventh day by VAS, subjective evaluation and pain threshold algometry. The study group consisted of 29 patients and the control group 27 patients. Pain at rest was significantly relieved in the ketoprofen group, whereas in the placebo group the difference was not significant. In terms of side-effects, no difference between the groups was noticed. In both groups, local dermal irritation was found. Our results suggested that ketoprofen 2.5% gel was safe and superior to placebo in the treatment of soft tissue injuries.

The physical strain of dairy farming.

The aim of this study was to estimate the physical stress and strain in diary farming, using ambulatory heart rate and oxygen consumption measurements. The rate of perceived exertion was estimated with Borg scale. The maximal oxygen consumption was measured in the laboratory. The study group consisted of eight male and 15 female farmers. The handling of feed and manure was the heaviest work task in dairy farming. The aerobic capacity (VO2 max) of female farmers (26 +/- 3 ml/min/kg) was below average, and their work required over 50% of VO2 max during most of the tasks. The VO2 max of male farmers (32 +/- 10 ml/min/kg) was moderate, and most work tasks required below 50% of VO2 max. The mean heart rate in dairy farming tasks was 99 beats min-1 in men and 116 beats min-1 in women. However, according to the rate of perceived exertion, the mean experienced the same work tasks as subjectively more heavy than did the women. The physical strain of female farmers in dairy farming seems to be too high because of heavy work tasks and relatively low VO2 max of women. Special attention should be paid to these factors in the occupational health services for farmers.

Effect of omega-3 fatty acid supplementation on platelet aggregability and platelet produced thromboxane.

We investigated the sustained effect of 12-week supplementation of 2.880 g/day of omega-3 fatty acids on platelet aggregability, platelet produced thromboxane B2 concentration and serum fatty acid composition in a double-blind controlled trial in 44 healthy mildly overweight eastern Finnish men recruited from a representative population sample. The supplementation was discontinued seven days before the biochemical measurements. Body weight, alcohol consumption and dietary composition remained constant during the study. Even though the percentage of eicosapentaenoic acid (20:5 omega 3) in total serum lipids increased by 37% (p less than 0.01) and that of dihomo-gamma-linolenic acid (20:3 omega 6) decreased by 18% (p less than 0.01) more in the omega-3 supplemented than placebo group during supplementation, there were no significant differences in the changes in either the ADP induced platelet aggregation or in vitro platelet produced thromboxane B2 concentration between the groups. These data suggest that omega-3 fatty acids have no detectable sustained effect either on ADP induced platelet aggregation or on thromboxane produced by the platelets in vitro.

Effects of bevantolol and atenolol on symptoms, exercise tolerance and metabolic risk factors in angina pectoris.

To assess the effects of bevantolol on stable angina pectoris of effort and its impact on metabolic risk factors, a comparison study of this beta 1-blocking agent and atenolol was undertaken in 40 subjects (mean age 51 years). After a 4-week, single-blind, placebo washout period, 12 men and 8 women were randomized to receive 150 mg of bevantolol twice daily and 12 men and 8 women to treatment with 100 mg of atenolol once daily in a parallel, double-blind, 12-week treatment phase. Patients were assessed at weeks 2, 6 and 12 after bicycle exercise until angina or ST-segment depression greater than or equal to 0.15 mV appeared. Concentrations of cholesterol lipoproteins and 3 prostaglandin metabolites were determined. One patient receiving bevantolol was withdrawn from the study because of insufficient efficacy and 2 receiving atenolol were withdrawn because of side effects. After 2 weeks of therapy, significant decreases were seen in both groups in the number of angina attacks, mean sitting heart rate, systolic and diastolic blood pressure, mean maximum heart rate during exercise and mean double-product of systolic blood pressure and heart rate at the end of exercise. There was a trend toward significance in the increase of mean duration of exercise and total work performed with both agents, although these values were not statistically significant. Both high density lipoproteins and the ratio of high density lipoproteins to low density lipoproteins increased in the bevantolol group and decreased in the atenolol group. These changes were statistically significant at week 6.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of platelet aggregability by moderate-intensity physical exercise: a randomized clinical trial in overweight men.

It has been postulated that platelet function plays an important role in the initiation of atherosclerosis. Currently there are no definitive data on the longer-term effects of regular physical exercise on platelet function in humans. We assessed the influence of regular moderate-intensity physical exercise (brisk walking to slow jogging) on platelet aggregation in a population-based sample of middle-aged, overweight, mildly hypertensive men in eastern Finland. In this controlled study, we evaluated the net effect of exercise on platelet aggregation by studying changes in optical density and ATP release in platelet-rich plasma. A significant inhibition of secondary platelet aggregation from 27% to 36% was observed in the men taking regular exercise. These findings give new insight into the possible protective effects of exercise against the risk of ischemic heart disease.