Exposure levels of asthmatic children to allergens, endotoxins, and serine proteases in a tropical environment

Novel inhibitors and activity-based probes targeting serine proteases

Serine proteases play varied and manifold roles in important biological, physiological, and pathological processes. These include viral, bacterial, and parasitic infection, allergic sensitization, tumor invasion, and metastasis. The use of activity-based profiling has been foundational in pinpointing the precise roles of serine proteases across this myriad of processes. A broad range of serine protease-targeted activity-based probe (ABP) chemotypes have been developed and we have recently introduced biotinylated and "clickable" peptides containing P1 N-alkyl glycine arginine N-hydroxy succinimidyl (NHS) carbamates as ABPs for detection/profiling of trypsin-like serine proteases. This present study provides synthetic details for the preparation of additional examples of this ABP chemotype, which function as potent irreversible inhibitors of their respective target serine protease. We describe their use for the activity-based profiling of a broad range of serine proteases including trypsin, the trypsin-like protease plasmin, chymotrypsin, cathepsin G, and neutrophil elastase (NE), including the profiling of the latter protease in clinical samples obtained from patients with cystic fibrosis.

Environmental exposure to endotoxin and its health outcomes: A systematic review

Exposure to endotoxin occurs environmentally and occupationally. There are several differences between them in terms of the variety and severity of health outcomes, possible exposed groups and type and route of exposure. Occupational exposures caused adverse health outcomes in almost all cases, but there is disparity in the incidence of significant health outcomes due to environmental exposure to endotoxin. This study has therefore endeavoured to investigate health outcomes from environmental exposure to endotoxin. A systematic review was conducted of three databases and non-occupational studies reporting the environmental concentration of endotoxin, and observed health outcomes in exposed groups were included in the review (n = 27). The studies showed that first exposure to endotoxin occurs in infancy by the inhalation route. Inhalation is the only exposure route that can induce inflammation as the main symptom of exposure to endotoxin. The studies included were conducted using four approaches: molecular immunology, measurement of lung volumes, clinical sensitisation test and diagnosis of asthmatic and respiratory symptoms such as wheezing. By the immunological approach, all the included studies reported that environmental exposure to endotoxin, especially at a younger age, has a protective effect on the incidence of asthma in adolescence. The main disparity observed was in studies using the approach of diagnosed asthma. Overall, however, they confirm the protective effect of exposure to endotoxin although, in the case of children with non-atopic asthma, the results could be different.

Tandem mass tags labeled quantitative proteomics to study the effect of tobacco smoke exposure on the rat lung

BACKGROUND

The causal link between tobacco smoke exposure (TSE) and numerous severe respiratory system diseases (RSD), including chronic bronchitis, chronic obstructive pulmonary disease, and lung cancer, is well established. However, the pathogenesis of TSE-induced RSD remains incompletely understood. This research aims to detect the pathogenetic mechanisms and potential therapeutic targets of TSE-induced RSD.

METHODS

This study employed TSE model which rats were exposed to a concentration of 60% tobacco smoke in a toxicant exposure system for four weeks. Tandem mass tags (TMT) labeled quantitative proteomics combined with off-line high pH reversed-phase fractionation, and nano-liquid chromatography-mass spectrometry method (off-line high pH RPF-nano-LC-MS/MS) were adopted to detect differentially expressed proteins (DEPs) in the lung tissues of the TSE model rats and to compare them with those in control. The accuracy of the results was verified by western blot.

RESULTS

Compared with the control group, 33 proteins in the TSE model group's lung tissues showed significant differential expression. Analysis based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways indicated that, several biological pathways, such as the steroid biosynthesis pathway, were involved and played significant roles in the pathogenesis of the experimental group's TSE.

CONCLUSIONS

These findings make a crucial contribution to the search for a comprehensive understanding of TSE-induced RSD's pathogenesis, and furthermore provide guidance for the diagnosis and treatment of TSE-induced RSD.

Multi-Approach Analysis for the Identification of Proteases within Birch Pollen

Birch pollen allergy is highly prevalent, with up to 100 million reported cases worldwide. Proteases in such allergen sources have been suggested to contribute to primary sensitisation and exacerbation of allergic disorders. Until now the protease content of Betula verrucosa, a birch species endemic to the northern hemisphere has not been studied in detail. Hence, we aim to identify and characterise pollen and bacteria-derived proteases found within birch pollen. The pollen transcriptome was constructed via de novo transcriptome sequencing and analysis of the proteome was achieved via mass spectrometry; a cross-comparison of the two databases was then performed. A total of 42 individual proteases were identified at the proteomic level. Further clustering of proteases into their distinct catalytic classes revealed serine, cysteine, aspartic, threonine, and metallo-proteases. Further to this, protease activity of the pollen was quantified using a fluorescently-labelled casein substrate protease assay, as 0.61 ng/mg of pollen. A large number of bacterial strains were isolated from freshly collected birch pollen and zymographic gels with gelatinase and casein, enabled visualisation of proteolytic activity of the pollen and the collected bacterial strains. We report the successful discovery of pollen and bacteria-derived proteases of Betula verrucosa.

Particulate matter properties and health effects: consistency of epidemiological and toxicological studies

Identifying the ambient particulate matter (PM) fractions or constituents, critically involved in eliciting adverse health effects, is crucial to the implementation of more cost-efficient abatement strategies to improve air quality. This review focuses on the importance of different particle properties for PM-induced effects, and whether there is consistency in the results from epidemiological and experimental studies. An evident problem for such comparisons is that epidemiological and experimental data on the effects of specific components of ambient PM are limited. Despite this, some conclusions can be drawn. With respect to the importance of the PM size-fractions, experimental and epidemiological studies are somewhat conflicting, but there seems to be a certain consistency in that the coarse fraction (PM10-2.5) has an effect that should not be neglected. Better exposure characterization may improve the consistency between the results from experimental and epidemiological studies, in particular for ultrafine particles. Experimental data indicate that surface area is an important metric, but composition may play an even greater role in eliciting effects. The consistency between epidemiological and experimental findings for specific PM-components appears most convincing for metals, which seem to be important for the development of both pulmonary and cardiovascular disease. Metals may also be involved in PM-induced allergic sensitization, but the epidemiological evidence for this is scarce. Soluble organic compounds appear to be implicated in PM-induced allergy and cancer, but the data from epidemiological studies are insufficient for any conclusions. The present review suggests that there may be a need for improvements in research designs. In particular, there is a need for better exposure assessments in epidemiological investigations, whereas experimental data would benefit from an improved comparability of studies. Combined experimental and epidemiological investigations may also help answer some of the unresolved issues.

Allergy sensitization and asthma among 13-14 year old school children in Nigeria

BACKGROUND

The prevalence of asthma and role of atopy in asthma among children has not been clearly defined in Nigeria.

OBJECTIVE

To determine the prevalence of asthma and investigate risk factors related to allergy sensitization among urban and rural school children in southwest Nigeria.

METHODS

Validated ISAAC questionnaire was administered to 1736 high school children in randomly selected schools in rural and urban communities. Identified asthma cases were matched to controls. Allergy skin tests, blood eosinophil count, serum IgE and stool examination for parasites were performed. Dust samples from homes were also collected and analyzed for allergens.

RESULTS

The prevalence of asthma was 7.5% (95% CI 6.0 to 9.2%) and 8% (95% CI 6.0-10.4%) in the rural and urban communities respectively . Risk factors for asthma included cigarette-smoking, cats in the home and family size. Eosinophil count (109/L) was elevated in asthmatics [0.70 (95% CI 0.48-1.11) vs. 0.32 (95% CI 0.19-0.69); p<0.01], but IgE levels were similar between the two groups (298±229 IU/mL vs. 288±257; p=0.97). Positive skin tests to cat hair, cockroach, mango blossom and mouse epithelium were more frequent in asthmatics than in healthy controls, especially in the rural communities. There was no correlation between allergens in dust collected from homes and skin test reactivity.

CONCLUSION

Asthma prevalence is similar in rural and urban children in Southwest Nigeria and atopy with elevated IgE was not observed to be a major factor for asthma in our cohort of children in both communities.

Mouse allergen, lung function, and atopy in Puerto Rican children

Objective

To examine the relation between mouse allergen exposure and asthma in Puerto Rican children.

Methods

Mus m 1, Der p 1, Bla g 2, and Fel d 1 allergens were measured in dust samples from homes of Puerto Rican children with (cases) and without (controls) asthma in Hartford, CT (n = 449) and San Juan (SJ), Puerto Rico (n = 678). Linear or logistic regression was used for the multivariate analysis of mouse allergen (Mus m 1) and lung function (FEV₁ and FEV₁/FVC) and allergy (total IgE and skin test reactivity (STR) to ≥1 allergen) measures.

Results

Homes in SJ had lower mouse allergen levels than those in Hartford. In multivariate analyses, mouse allergen was associated with higher FEV₁ in cases in Hartford (+70.6 ml, 95% confidence interval (CI) = 8.6–132.7 ml, P = 0.03) and SJ (+45.1 ml, 95% CI =  −0.5 to 90.6 ml, P = 0.05). In multivariate analyses of controls, mouse allergen was inversely associated with STR to ≥1 allergen in non-sensitized children (odds ratio [OR] for each log-unit increment in Mus m 1 = 0.7, 95% CI = 0.5–0.9, P<0.01). In a multivariate analysis including all children at both study sites, each log-increment in mouse allergen was positively associated with FEV₁ (+28.3 ml, 95% CI = 1.4–55.2 ml, P = 0.04) and inversely associated with STR to ≥1 allergen (OR for each log-unit increment in Mus m 1 = 0.8, 95% CI = 0.6–0.9, P<0.01).

Conclusions

Mouse allergen is associated with a higher FEV₁ and lower odds of STR to ≥1 allergen in Puerto Rican children. This may be explained by the allergen itself or correlated microbial exposures.

Mite sensitization among Latina women in New York, where dust-mite allergen levels are typically low

In New York (NY), Latinos often have greater asthma morbidity than other ethnicities, and dust-mite sensitization is common despite low allergen levels. We investigated mite allergen exposure and sensitization in atopic and/or asthmatic women, the majority being Puerto Rican. Women (n = 274) recruited for a birth cohort study were visited postnatally. Dust from their homes was analyzed for mite allergens (Der f 1, Der p 1, and Blo t 5). Serum was analyzed for total and allergen-specific IgE. Thirty-seven percent were sensitized to Dermatophagoides pteronyssinus, 34% to Dermatophagoides farinae, and 21% to Blomia tropicalis. Only 5% of NY homes had levels of Der f 1 >2 microg/g; none had Blo t 5 or Der p 1 above this level. Caribbean or Latin American birthplace (a proxy for childhood exposure) was not associated with mite sensitization. Sensitization to D. pteronyssinus and D. farinae was associated with a report of doctor-diagnosed asthma [Odds ratio (OR) = 3.27, P = 0.003; OR = 2.81, P = 0.010, respectively]; sensitization to any mite was associated with asthma medication use in the past 12 months (OR = 3.12, P = 0.004). These associations held even after adjustment for cockroach, mouse, and cat sensitization.

PRACTICAL IMPLICATIONS

Despite the low concentrations of mite allergen in our community, many of the women in the atopically enriched cohort were sensitized to mites, even Blomia tropicalis which is typically found only in tropical environments.

Asthma in the inner city and the indoor environment

Inner-city residents continue to suffer disproportionate asthma morbidity despite recent progress in reducing asthma morbidity and mortality in other strata of the United States population. Studies over the past decade indicate that the indoor environment is a strong contributor to poor asthma control and asthma-related health care use in inner-city populations. Certain indoor exposures are more common and occur in higher concentrations in inner-city communities than in suburban communities. Identification of "asthmagenic" indoor exposures has paved the way for the development of intervention strategies aimed at reducing asthma morbidity. This article reviews the growing body of evidence that certain indoor environmental exposures contribute to the burden of asthma in the inner city.

A pilot study to assess residential endotoxin and blood IgE in a group of pregnant women from Trujillo, Peru

OBJECTIVE

This November 2003 pilot study investigates the correlation between serum IgE and residential endotoxin levels from a group of 18 pregnant women living in Trujillo, Peru, and investigates the impact of the demographic and lifestyle factors of this group on the IgE and endotoxin levels measured.

METHODS

Serum samples were collected from 19 subjects and analyzed for IgE. Dust samples were collected from the mattresses of 18 subjects and measured for endotoxin levels. A questionnaire was used to obtain demographic, socioeconomic, and lifestyle information for each subject.

RESULTS

Geometric means for IgE and endotoxin were 246.8 (GSD=4.3, n=19) IU/mL and 66.5 EU/mg (GSD=1.7, n=18), respectively. Log-transformed IgE and endotoxin were not correlated (R2=0.02; p=0.60).

CONCLUSIONS

Residential endotoxin and serum IgE were not correlated in this group. Potential selection bias and sample size are major limitations of the study. However, 74% (14/19) of the subjects in this study had an IgE over 100 IU/mL, a level generally considered elevated.

Childhood asthma prevalence in northern Puerto Rico, the Rio Grande, and Loíza experience

OBJECTIVE

Childhood asthma is highly prevalent in some areas of Puerto Rico. The objective of this study was to estimate the prevalence of asthma in two municipalities of Northern Puerto Rico.

METHODS

Children 6 to 7 and 13 to 14 years of age participated in the school-based cross-sectional study.

RESULTS

A total of 1,467 elementary school students and 1,334 junior-high school students were included in the survey. A high prevalence of asthma was observed; 46% in elementary schools and 24% in junior-high schools. In elementary schools, family history of asthma (FHA) was associated with ever wheezed (PR = 2.00, 95%CI 1.59, 2.52), wheeze during last year (PR = 2.02, 95%CI 1.54, 2.62), and asthma (PR = 2.33, 95%CI 1.86, 2.92). For junior-high schools FHA was associated with ever wheezed (PR = 2.01, 95%CI 1.56, 2.57), wheeze during previous year (PR = 2.00, 95%CI 1.47, 2.73), and asthma (PR = 2.72, 95%CI 2.06, 3.60).

CONCLUSIONS

This study showed a high prevalence of asthma and related symptoms in Northern Puerto Rico. FHA was strongly associated with asthma and its symptoms. Further research is recommended to look at genetics, sensitivity levels, indoor and outdoor pollution, and gene-environment interactions.

Serine proteases, their inhibitors and allergy

This paper reviews four serine protease inhibitors and three protease gene defects that are associated with allergic conditions, suggesting an important role for these genes and their products in the development of allergy. Serine protease inhibitors may have a therapeutic potential in the treatment of allergy.

Risk assessment and community participation model for environmental asthma management in an elementary public school: a case study in Puerto Rico

Asthma is a rapidly growing chronic disease in the general population of the world, mostly in children. Puerto Ricans have the highest prevalence of children with asthma among the Hispanic community in the US and its territories. Asthma and air quality are becoming a significant and potentially costly public health issue in Puerto Rico. The CDC has reported that in Puerto Rico, 320,350 adults have asthma and this number represents 11.5% of the island adult population. The north east municipality of Carolina, Puerto Rico, has the highest asthma prevalence in the 0 to 17 year old range (2001 data). In this study, we address the potential relationship between anthropogenic and naturally occurring environmental factors, and asthma prevalence in an urban elementary public school in Carolina in an effort to empower and engage communities to work on their environmental health issues. We integrated geographic information systems (GIS) data of anthropogenic activities near the school as well as the natural resources and geomorphology of the region. We found that as Carolina is close by to Caribbean National Forest (El Yunque), this together with the temperature and precipitation cycles in the zone creates the ideal environmental conditions for increased humidity and pollen, mold and fungi development through out the year. We also collected health and socio economic data to generate an asthma profile of the students, employees and parents from the school community, and through a survey we identified perceptions on environmental asthma triggers, and indoor air quality in the school and homes of the students and employees. Finally, we implemented a workshop on indoor air quality designed to engage the school community in managing asthma triggers and the school environment. Our results showed that nearly 30 % of its student's population has asthma, and from this group 58% are males and 42% are female students. Of all asthmatic children, only 43% receive treatment for the disease. The study also showed that most asthmatic children are between 7 and 9 year old, and live in households with an annual income below 10,000 dollars. It also showed that 25 % of the student's parents have the condition, and that 25% of the employees are also affected by this chronic condition. All these numbers are significantly higher than those reported by the CDC for Puerto Rico. The perception component had a response of 83% of school employees, and a 39% response from parents. It showed that people know asthma as a disease but many can't identify most environmental asthma triggers. Pre and post tests of the workshop protocol showed that before the activity only 21% of participants can identify asthma triggers. At the end of the workshop nearly 80% were able to identify and manage environmental asthma triggers. This work validates the fact that Puerto Rico continues to have a significant number of people with asthma, particularly children asthma, and that schools are an important settings to create community based action plans to manage environmental asthma triggers through outreach and training.

Asthma in Hispanics

Hispanic individuals trace their ancestry to countries that were previously under Spanish rule, including Mexico, large parts of Central and South America, and some Caribbean islands. Most--but not all--Hispanics have variable proportions of European, Amerindian, and African ancestry. Hispanics are diverse with regard to many factors, including racial ancestry, country of origin, area of residence, socioeconomic status, education, and access to health care. Recent findings suggest that there is marked variation in the prevalence, morbidity, and mortality of asthma in Hispanics in the United States and in Hispanic America. The reasons for differences in asthma and asthma morbidity among and within Hispanic subgroups are poorly understood but are likely due to the interaction between yet-unidentified genetic variants and other factors, including environmental tobacco smoke exposure, obesity, allergen exposure, and availability of health care. Barriers to optimal management of asthma in Hispanics in the United States and in Hispanic America include inadequate access to health care, suboptimal use of antiinflammatory medications, and lack of reference values for spirometric measures of lung function in many subgroups (e.g., Puerto Ricans). Future studies of asthma in Hispanics should include large samples of subgroups that are well characterized with regard to self-reported ethnicity, country of origin, place of birth, area of residence, and indicators of socioeconomic status. Because Hispanics are disproportionately represented among the poor in the United States, implementation of adequate access to health care and social reforms (e.g., improving housing conditions) would likely have a major impact on reducing asthma morbidity in this population.

Endotoxin and the lung: Insight into the host-environment interaction

Understanding the pathophysiology and basic mechanisms of asthma and chronic obstructive pulmonary disease (COPD) has been an intense source of investigation over the years. For decades, research in these fields has focused on the control of inflammation. However, new evidence has emerged demonstrating that airway inflammation is just the surface of a more complex pathobiological relationship between the disease and its host. Specifically, the relationship is a unique interaction of one's genetic background and the environment. The airway response to inhaled endotoxin serves as an effective model for studying the pathobiology of asthma as well as the importance of host genetic susceptibility. In this review, we provide a brief overview on the role of endotoxin in asthma and COPD, highlighting a few of the major discoveries, but also discussing future directions.