Beverage consumption and obesity in Kuwaiti school children.

Sweetened beverage consumption is particularly important in countries such as Kuwait, where the prevalence of obesity is high, and most children drink sweetened beverages daily. To assess the relationship between three most commonly consumed beverages, (soda, milk, and juice) and the incidence of obesity among Kuwaiti children at the critical age of 10-12 year, Longitudinal cohort data of 6,305 children on initial presentation in 2012 (age, 10 years) and follow-up in 2014 (age, 12 years) were obtained from the Kuwait Healthy Life Study. The servings for the three beverages (soda, juice, and milk) were calculated as servings per day groups (0, 1-2, and 3 servings/day or more). Multivariate logistic regression was performed to assess the relationship between developing obesity during 2012-2014 and soda, juice, and milk consumption. Model selection was based on clinically relevant covariates and potential confounders using stepwise model selection. Six percent children become obese between baseline and follow-up visits. High soda drinking showed significant association with developing obesity. High milk consumption (more than 3 servings a day) was also significantly associated with developing obesity. Potential confounders included in the final model were age, sex, governorates, and fitness level, of which none were significant confounders or effect modifiers for the association. Children with high soda consumption had significantly higher prevalence of obesity. High obesity prevalence was observed with high milk consumption at a lower significance level but not with high juice consumption.

Salivary N1-Methyl-2-Pyridone-5-Carboxamide, a Biomarker for Uranium Uptake, in Kuwaiti Children Exhibiting Exceptional Weight Gain.

In a longitudinal study of 6,158 Kuwaiti children, we selected 94 for salivary metabolomic analysis who were neither obese (by waist circumference) nor metabolic syndrome (MetS) positive (<3 diagnostic features). Half (43) remained healthy for 2 years. The other half (51) were selected because they became obese and MetS positive 2 years later. In the half becoming obese, metabolomic analysis revealed that the level of salivary N1-Methyl-2-pyridone-5-carboxamide (2PY) had the highest positive association with obesity (p = 0.0003, AUC = 0.72) of 441 salivary biochemicals detected. 2PY is a recognized uremic toxin. Also, 2PY has been identified as a biomarker for uranium uptake. Considering that a relatively recent military conflict with documented uranium contamination of the area suggests that this weight gain could be a toxicological effect of long-time, low-level uranium ingestion. Comparison of salivary 2PY in samples from the USA and Kuwait found that only Kuwait samples were significantly related to obesity. Also, the geographic distribution of both reported soil radioactivity from 238U and measured salivary 2PY was highest in the area where military activity was highest. The prevalence pattern of adult diabetes in Kuwait suggests that a transient diabetogenic factor has been introduced into the Kuwaiti population. Although we did not measure uranium in our study, the presence of a salivary biomarker for uranium consumption suggests potential toxicity related to obesity in children.

Corrigendum: Caveolin-1 Variant Is Associated With the Metabolic Syndrome in Kuwaiti Children.

[This corrects the article DOI: 10.3389/fgene.2018.00689.].

Caveolin-1 Variant Is Associated With the Metabolic Syndrome in Kuwaiti Children.

Caveolin-1 (CAV1) variants have been suggested to be associated with obesity and related metabolic disorders, but information based on human studies is limited. In the present study, we aimed to investigate the potential association between the CAV1 rs1997623 C/A variant and metabolic syndrome (MetS) in Kuwaiti children. DNA from saliva samples collected from 1313 Kuwaiti children (mean age: 12 years) were genotyped using the TaqMan SNP genotyping assay. The classification of MetS was based on the presence/absence of four indicators; (1) central obesity, (2) elevated systolic or diastolic blood pressure, (3) low salivary high-density lipoprotein cholesterol (HDLC), and (4) high salivary glucose. In this study, children with MetS scored ≥3, children in the intermediate metabolic group scored 1 or 2 and children without MetS scored 0. About one-third of the children were obese. A total of 246 children (18.7%) were classified as having MetS; 834 children (63.5%) were in the intermediate metabolic group, and 233 children (17.7%) had no indication of MetS. Obesity was highly prevalent in the MetS group (91.9%) while 26.8% of children were obese in the intermediate metabolic group. None of the children were obese in the group without MetS. Analysis of the CAV1 rs1997623 variant revealed a significant association of the A-allele (p = 0.01, Odds Ratio (OR) = 1.66) and the heterozygous CA-genotype (p = 0.005, OR = 1.88) with MetS. Consistently, the A-allele (p = 0.002, OR = 1.71) and CA-genotype (p = 0.005, OR = 1.70) also showed significant association with the intermediate metabolic group. Furthermore, the A-allele (p = 0.01, OR = 1.33) and the CA-genotype (p = 0.008, OR = 1.55) were associated with low levels of saliva HDLC. Individuals who were heterozygous or homozygous for the variant (CA/AA) showed significantly lower levels of high HDLC compared to those harboring the CC-genotype (p = 0.023). Our study revealed a novel association of the CAV1 rs1997623 variant with the MetS and with low saliva HDLC levels in young Kuwaiti children and indicated the need for further in-depth studies to unravel the role of CAV1 gene in the genetic etiology of MetS.

The salivary microbiome is altered in the presence of a high salivary glucose concentration.

BACKGROUND: Type II diabetes (T2D) has been associated with changes in oral bacterial diversity and frequency. It is not known whether these changes are part of the etiology of T2D, or one of its effects. METHODS: We measured the glucose concentration, bacterial counts, and relative frequencies of 42 bacterial species in whole saliva samples from 8,173 Kuwaiti adolescents (mean age 10.00 ± 0.67 years) using DNA probe analysis. In addition, clinical data related to obesity, dental caries, and gingivitis were collected. Data were compared between adolescents with high salivary glucose (HSG; glucose concentration ≥ 1.0 mg/d, n = 175) and those with low salivary glucose (LSG, glucose concentration < 0.1 mg/dL n = 2,537). RESULTS: HSG was associated with dental caries and gingivitis in the study population. The overall salivary bacterial load in saliva decreased with increasing salivary glucose concentration. Under HSG conditions, the bacterial count for 35 (83%) of 42 species was significantly reduced, and relative bacterial frequencies in 27 species (64%) were altered, as compared with LSG conditions. These alterations were stronger predictors of high salivary glucose than measures of oral disease, obesity, sleep or fitness. CONCLUSIONS: HSG was associated with a reduction in overall bacterial load and alterations to many relative bacterial frequencies in saliva when compared with LSG in samples from adolescents. We propose that hyperglycemia due to obesity and/or T2D results in HSG and subsequent acidification of the oral environment, leading to a generalized perturbation in the oral microbiome. This suggests a basis for the observation that hyperglycemia is associated with an increased risk of dental erosion, dental caries, and gingivitis. We conclude that HSG in adolescents may be predicted from salivary microbial diversity or frequency, and that the changes in the oral microbial composition seen in adolescents with developing metabolic disease may the consequence of hyperglycemia.

Unhealthy Phenotype as Indicated by Salivary Biomarkers: Glucose, Insulin, VEGF-A, and IL-12p70 in Obese Kuwaiti Adolescents.

OBJECTIVE: Here, we investigated the relationships between obesity and the salivary concentrations of insulin, glucose, and 20 metabolic biomarkers in Kuwaiti adolescents. Previously, we have shown that certain salivary metabolic markers can act as surrogates for blood concentrations. METHODS: Salivary samples of whole saliva were collected from 8,317 adolescents. Salivary glucose concentration was measured by a high-sensitivity glucose oxidase method implemented on a robotic chemical analyzer. The concentration of salivary insulin and 20 other metabolic biomarkers was assayed in 744 randomly selected saliva samples by multiplexed bead-based immunoassay. RESULTS: Obesity was seen in 26.5% of the adolescents. Salivary insulin predicting hyperinsulinemia occurred in 4.3% of normal-weight adolescents, 8.3% of overweight adolescents, and 25.7% of obese adolescents (p < 0.0001). Salivary glucose predicting hyperglycemia was found in only 3% of obese children and was not predictive (p = 0.89). Elevated salivary glucose and insulin occurring together was associated with elevated vascular endothelial growth factor and reduced salivary interleukin-12. CONCLUSION: Considering the surrogate nature of salivary insulin and glucose, this study suggests that elevated insulin may be a dominant sign of metabolic disease in adolescent populations. It also appears that a proangiogenic environment may accompany elevated glucose in obese adolescents.

Salivary Biomarkers in Pediatric Metabolic Disease Research.

The increasing prevalence of childhood obesity and obesity-related metabolic disorders is now considered a global pandemic. The main goal of the pediatric obesity research community is to identify children who are at risk of becoming obese before their body mass index rises above age norms. To do so, we must identify biomarkers of metabolic health and immunometabolism that can be used for large-scale screening and diagnosis initiatives among at-risk children. Because blood sampling is often unacceptable to both parents and children when there is no direct benefit to the child, as in a community-based research study, there is a clear need for a low-risk, non-invasive sampling strategy. Salivary analysis is now well recognized as a likely candidate for this purpose. In this review, we discuss the physiologic role of saliva and its strengths and limitations as a fluid for biomarker discovery, obesity screening, metabolic disease diagnosis, and response monitoring after interventions. We also describe the current state of the salivary biomarker field as it pertains to metabolic research, with a special emphasis on studies conducted in children and adolescents. Finally, we look forward to technological developments, such as salivary "omics" and point of service diagnostic devices, which have the potential to accelerate the pace of research and discovery in this vitally important field.

Continuous Metabolic Syndrome Scores for Children Using Salivary Biomarkers.

BACKGROUND: Binary definitions of the metabolic syndrome based on the presence of a particular number of individual risk factors are limited, particularly in the pediatric population. To address this limitation, we aimed at constructing composite and continuous metabolic syndrome scores (cmetS) to represent an overall measure of metabolic syndrome (MetS) in a large cohort of metabolically at-risk children, focusing on the use of the usual clinical parameters (waist circumference (WC) and systolic blood pressure (SBP), supplemented with two salivary surrogate variables (glucose and high density lipoprotein cholesterol (HDLC). Two different approaches used to create the scores were evaluated in comparison. METHODS: Data from 8,112 Kuwaiti children (10.00 ± 0.67 years) were used to construct two cmetS for each subject. The first cmetS (cmetS-Z) was created by summing standardized residuals of each variable regressed on age and gender; and the second cmetS (cmetS-PCA) was defined as the first principal component from gender-specific principal component analysis based on the four variables. RESULTS: There was a graded relationship between both scores and the number of adverse risk factors. The areas under the curve using cmetS-Z and cmetS-PCA as predictors for severe metabolic syndrome (defined as the presence of ≥3 metabolic risk factors) were 0.935 and 0.912, respectively. cmetS-Z was positively associated with WC, SBP, and glucose, but inversely associated with HDLC. Except for the lack of association with glucose, cmetS-PCA was similar to cmetS-Z in boys, but had minimum loading on HDLC in girls. Analysis using quantile regression showed an inverse association of fitness level with cmetS-PCA (p = 0.001 for boys; p = 0.002 for girls), and comparison of cmetS-Z and cmetS-PCA suggested that WC and SBP were main contributory components. Significant alterations in the relationship between cmetS and salivary adipocytokines were demonstrated in overweight and obese children as compared to underweight and normal-weight children. CONCLUSION: We have derived continuous summary scores for MetS from a large-scale pediatric study using two different approaches, incorporating salivary measures as surrogate for plasma measures. The derived scores were viable expressions of metabolic risk, and can be utilized to study the relationships of MetS with various aspects of the metabolic disease process.

Salivary glucose concentration exhibits threshold kinetics in normal-weight, overweight, and obese children.

BACKGROUND: Metabolic syndrome in childhood predicts the development of cardiovascular disease and type 2 diabetes (T2D) in adulthood. Testing for features of metabolic syndrome, such as fasting plasma glucose concentration, requires blood sampling which can be difficult in children. Here we evaluated salivary glucose concentration as a surrogate measurement for plasma glucose concentration in 11-year-old US children. METHODS: Children from Portland, Maine, and Cambridge, Massachusetts, with a mean age of 10.6±0.2 years provided 6-hour fasting samples of both blood and whole saliva. Salivary glucose levels were measured with a high-sensitivity assay (sensitivity =0.002 mg/dL). Plasma glucose levels were determined by a commercial clinical laboratory. Blood pressure, salivary flow rate, height, and weight were also measured. RESULTS: Of the 65 children enrolled, there were two underweight children (3.1%), 30 normal-weight children (46.2%), 12 overweight children (18.4%), and 21 obese children (32.3%). The mean overall glucose concentrations were 0.11±0.02 mg/dL in saliva and 86.3±0.8 mg/dL in plasma, and these did not differ significantly by body-weight groups. By regression analysis, the plasma concentration equaled 13.5 times the saliva concentration, with a threshold level of 84.8 mg/dL. Salivary glucose values less than threshold plasma concentration were essentially zero. Diagnostic analysis indicated a positive predictive value of 50%, a negative predictive value of 90%, and a sensitivity and specificity both of approximately 75%. The salivary glucose concentration did not vary with saliva flow rate. CONCLUSION: Taking into account the threshold response characteristics of the salivary glucose concentration response, these results suggest that testing salivary glucose levels may be useful as a screening assay for high fasting plasma glucose levels. The low false positive value is important to assure a low fraction of missed diagnoses.

Metabolic disease risk in children by salivary biomarker analysis.

OBJECTIVE: The study of obesity-related metabolic syndrome or Type 2 diabetes (T2D) in children is particularly difficult because of fear of needles. We tested a non-invasive approach to study inflammatory parameters in an at-risk population of children to provide proof-of-principle for future investigations of vulnerable subjects. DESIGN AND METHODS: We evaluated metabolic differences in 744, 11-year old children selected from underweight, normal healthy weight, overweight and obese categories by analyzing fasting saliva samples for 20 biomarkers. Saliva supernatants were obtained following centrifugation and used for analyses. RESULTS: Salivary C-reactive protein (CRP) was 6 times higher, salivary insulin and leptin were 3 times higher, and adiponectin was 30% lower in obese children compared to healthy normal weight children (all P<0.0001). Categorical analysis suggested that there might be three types of obesity in children. Distinctly inflammatory characteristics appeared in 76% of obese children while in 13%, salivary insulin was high but not associated with inflammatory mediators. The remaining 11% of obese children had high insulin and reduced adiponectin. Forty percent of the non-obese children were found in groups which, based on biomarker characteristics, may be at risk for becoming obese. CONCLUSIONS: Significantly altered levels of salivary biomarkers in obese children from a high-risk population, suggest the potential for developing non-invasive screening procedures to identify T2D-vulnerable individuals and a means to test preventative strategies.

Relation of mitochondrial oxygen consumption in peripheral blood mononuclear cells to vascular function in type 2 diabetes mellitus.

Recent studies have shown mitochondrial dysfunction and increased production of reactive oxygen species in peripheral blood mononuclear cells (PBMCs) and endothelial cells from patients with diabetes mellitus. Mitochondria oxygen consumption is coupled to adenosine triphosphate (ATP) production and also occurs in an uncoupled fashion during formation of reactive oxygen species by components of the electron transport chain and other enzymatic sites. We therefore hypothesized that diabetes would be associated with higher total and uncoupled oxygen consumption in PBMCs that would correlate with endothelial dysfunction. We developed a method to measure oxygen consumption in freshly isolated PBMCs and applied it to 26 patients with type 2 diabetes mellitus and 28 non-diabetic controls. Basal (192 ± 47 vs 161 ± 44 pmoles/min, p = 0.01), uncoupled (64 ± 16 vs 53 ± 13 pmoles/min, p = 0.007), and maximal (795 ± 87 vs 715 ± 128 pmoles/min, p=0.01) oxygen consumption rates were higher in diabetic patients compared to controls. There were no significant correlations between oxygen consumption rates and endothelium-dependent flow-mediated dilation measured by vascular ultrasound. Non-endothelium-dependent nitroglycerin-mediated dilation was lower in diabetics (10.1 ± 6.6 vs 15.8 ± 4.8%, p = 0.03) and correlated with maximal oxygen consumption (r = -0.64, p=0.001). In summary, we found that diabetes mellitus is associated with a pattern of mitochondrial oxygen consumption consistent with higher production of reactive oxygen species. The correlation between oxygen consumption and nitroglycerin-mediated dilation may suggest a link between mitochondrial dysfunction and vascular smooth muscle cell dysfunction that merits further study. Finally, the described method may have utility for the assessment of mitochondrial function in larger scale observational and interventional studies in humans.

Can salivary phosphate levels be an early biomarker to monitor the evolvement of obesity?

Phosphate is an essential nutrient required for important biological reactions that maintain the normal homoeostatic control of the cell. The adverse effects of phosphate metabolism in obesity have not been studied in detail, chiefly because such an association is thought to be uncommon. However, in some animal models of obesity, serum phosphate levels were noted to be higher than the nonobese controls. For example, leptin-deficient (ob/ob) mice become severely obese and have high serum phosphate levels. In this study, we analyzed the phosphate content in saliva collected from children (n = 77; 10.5 ± 1.8) to evaluate association with body mass index; there is a significant increase of salivary phosphate content in obese compared to normal-weight children (ANOVA p < 0.001). The correlation coefficient (r) between BMI and phosphate was 0.33 (p = 0.0032). Our results suggest that the human salivary phosphate level may be an early biomarker of the genesis of obesity in children. The diagnostic importance lies in the fact that the salivary phosphate level could provide a noninvasive predictive marker in the development of obesity. Further studies will be required to understand the underlying mechanism of increased salivary phosphate accumulation in obese and overweight children. Nevertheless, its occurrence without systemic changes could be of diagnostic value, particularly in monitoring evolvement of obesity.

Altered mitochondrial dynamics contributes to endothelial dysfunction in diabetes mellitus.

BACKGROUND: Endothelial dysfunction contributes to the development of atherosclerosis in patients with diabetes mellitus, but the mechanisms of endothelial dysfunction in this setting are incompletely understood. Recent studies have shown altered mitochondrial dynamics in diabetes mellitus with increased mitochondrial fission and production of reactive oxygen species. We investigated the contribution of altered dynamics to endothelial dysfunction in diabetes mellitus. METHODS AND RESULTS: We observed mitochondrial fragmentation (P=0.002) and increased expression of fission-1 protein (Fis1; P<0.0001) in venous endothelial cells freshly isolated from patients with diabetes mellitus (n=10) compared with healthy control subjects (n=9). In cultured human aortic endothelial cells exposed to 30 mmol/L glucose, we observed a similar loss of mitochondrial networks and increased expression of Fis1 and dynamin-related protein-1 (Drp1), proteins required for mitochondrial fission. Altered mitochondrial dynamics was associated with increased mitochondrial reactive oxygen species production and a marked impairment of agonist-stimulated activation of endothelial nitric oxide synthase and cGMP production. Silencing Fis1 or Drp1 expression with siRNA blunted high glucose-induced alterations in mitochondrial networks, reactive oxygen species production, endothelial nitric oxide synthase activation, and cGMP production. An intracellular reactive oxygen species scavenger provided no additional benefit, suggesting that increased mitochondrial fission may impair endothelial function via increased reactive oxygen species. CONCLUSION: These findings implicate increased mitochondrial fission as a contributing mechanism for endothelial dysfunction in diabetic states.

Combined treatment with cisplatin and sirolimus to enhance cell death in human mesothelioma.

OBJECTIVE: Although platinum-based chemotherapy is widely used in malignant pleural mesothelioma, its modest therapeutic effect warrants identification of enhancing agents. As with many cancers, the phosphatidylinositol 3-kinase/Akt pathway is often activated in malignant pleural mesothelioma and has been implicated in the tumor's aggressiveness. Sirolimus is a well-established inhibitor of the mammalian target of rapamycin. We sought to determine whether combination treatment with sirolimus and cisplatin would enhance cell death in malignant pleural mesothelioma. METHODS: Human malignant pleural mesothelioma cell lines were incubated with sirolimus or cisplatin alone or in combination and assayed for cell viability. To characterize phosphorylation status after treatment, Akt and downstream proteins of mammalian target of rapamycin pathway, p70 S6 kinase and 4E-BP1, were analyzed by Western blot. Effect of combination treatment was also analyzed with extreme drug resistance assay in 12 human malignant pleural mesothelioma tumors with varying resistance to cisplatin. RESULTS: Individual malignant pleural mesothelioma cell lines exhibited a range of sensitivities to each drug without correlation with subtype. Sirolimus and cisplatin significantly (P = .029) increased cell death versus either drug alone in 4 cell lines. Combined treatment caused dephosphorylation of Akt, 4E-BP1, and p70 S6 kinase. Cell proliferation was significantly decreased in tumors subjected to sirolimus and cisplatin versus cisplatin or sirolimus alone. CONCLUSIONS: Sirolimus appears to enhance the cytotoxicity of cisplatin in malignant pleural mesothelioma cell lines through the mammalian target of rapamycin pathway. These results provide a basis for the clinical evaluation of combined sirolimus and cisplatin chemotherapy in malignant pleural mesothelioma.

Transcriptome sequencing of malignant pleural mesothelioma tumors.

Cancers arise by the gradual accumulation of mutations in multiple genes. We now use shotgun pyrosequencing to characterize RNA mutations and expression levels unique to malignant pleural mesotheliomas (MPMs) and not present in control tissues. On average, 266 Mb of cDNA were sequenced from each of four MPMs, from a control pulmonary adenocarcinoma (ADCA), and from normal lung tissue. Previously observed differences in MPM RNA expression levels were confirmed. Point mutations were identified by using criteria that require the presence of the mutation in at least four reads and in both cDNA strands and the absence of the mutation from sequence databases, normal adjacent tissues, and other controls. In the four MPMs, 15 nonsynonymous mutations were discovered: 7 were point mutations, 3 were deletions, 4 were exclusively expressed as a consequence of imputed epigenetic silencing, and 1 was putatively expressed as a consequence of RNA editing. Notably, each MPM had a different mutation profile, and no mutated gene was previously implicated in MPM. Of the seven point mutations, three were observed in at least one tumor from 49 other MPM patients. The mutations were in genes that could be causally related to cancer and included XRCC6, PDZK1IP1, ACTR1A, and AVEN.

Role of the extracellular domain of Fc epsilon RI alpha in intracellular processing and surface expression of the high affinity receptor for IgE Fc epsilon RI.

The high affinity receptor for immunoglobulin E, Fc epsilon RI, is a critical component of IgE-mediated allergic reactions. It is expressed as a tetramer (alphabetagamma(2)) made of an IgE-binding alpha chain and a signaling module formed by the beta chain and a dimer of gamma chains. It is expressed in humans and rodents on basophils and mast cells at a high level, and, upon activation, it induces the liberation of allergy mediators. In humans a trimeric form lacking the beta chain also exists (alphagamma(2)). This trimeric form is expressed on antigen presenting cells where it acts to facilitate antigen presentation via IgE. Both the expression and the signaling capacity of the trimer are lower than those of the tetramer. The differences between human (tetrameric and trimeric) and murine (tetrameric only) expression is explained in part by the fact that mouse alpha cannot be expressed at the cell surface in the absence of beta, while human alpha can. Here we demonstrate that the capacity of human alpha to be expressed at the cell surface in the absence of beta is encoded entirely in its extracellular domain. These findings show that the extracellular domain of the type I transmembrane protein Fc epsilon RI alpha plays a role in Fc epsilon RI intracellular processing and expression at the cell surface.

Tryptase activates the mitogen-activated protein kinase/activator protein-1 pathway in human peripheral blood eosinophils, causing cytokine production and release.

We have previously shown that mast cells enhance eosinophil survival and activation. In this study we further characterized mast cell activity toward eosinophils. Sonicate of both rat peritoneal mast cells and the human mast cell line 1 (HMC-1) induced a concentration-dependent IL-6 and IL-8 release from human peripheral blood eosinophils (ELISA). HMC-1-induced IL-8 release was significantly reduced by the tryptase inhibitors GW-45 and GW-58 (90 and 87%, respectively, at an optimal concentration) but not by anti-stem cell factor, anti-TNF-alpha, or anti-IFN-gamma neutralizing Abs or by the antihistamine drugs pyrilamine and cimetidine. In a manner similar to HMC-1, human recombinant tryptase induced the expression of mRNA for IL-8 (RT-PCR) and caused IL-8 release from the eosinophils. Addition of cycloheximide, actinomycin D, dexamethasone, PD 98059, curcumin, or SB 202190 completely inhibited the tryptase-induced IL-6 and IL-8 release. In contrast, cyclosporin A had no effect on tryptase-induced IL-8 release. Tryptase caused phosphorylation of extracellular signal-regulated kinases 1 and 2, c-Jun N-terminal kinases 1 and 2, and p38 (Western blot). Tryptase also induced the translocation of c-Jun from the cytosol to the nucleus (confocal microscopy) and enhanced AP-1 binding activity to the DNA (EMSA). Eosinophils were found to express proteinase-activated receptor 2 (FACS). When eosinophils were incubated with tryptase in the presence of anti-proteinase-activated receptor 2 antagonist Abs a significant decrease in the IL-6 and IL-8 release occurred. In summary, we have demonstrated that the preformed mast cell mediator tryptase induces cytokine production and release in human peripheral blood eosinophils by the mitogen-activated protein kinase/AP-1 pathway.