Genetic effect of CysLTR2 polymorphisms on its mRNA synthesis and stabilization

Variants in the CYSLTR2 are associated with asthma, atopy markers and helminths infections in the Brazilian population

BACKGROUND

Asthma is a chronic disease of the airways and its most common phenotype is characterized by a T2 type response with IgE production and inflammatory mediators in response to common allergens. Cysteinyl leukotrienes (CysLTs), LTC4, LTD4 and LTE4, are mediators known to possess important proinflammatory action. CysLTs can bind to the Cysteinyl leukotriene receptor type 2 (CysLTR2) and activate an inflammatory. Polymorphisms in CysLTR2 have been associated with asthma and atopy, although the mechanism is not clear.

OBJECTIVE

To evaluate the association between genetic polymorphisms in CYSLTR2 with asthma phenotypes, atopy markers and helminth infection.

METHODS

Genotyping was performed using a panel Illumina and carried out in 1245 participants of SCAALA program (Social Change, Asthma, Allergy in Latin American). Logistic regressions for asthma, helminth infections (Trichuris trichiura and Ascaris lumbricoides) and allergy markers (skin tests and IgE production) were performed using PLINK 1.9 software adjusted for sex, age, helminth infection and ancestry markers.

RESULTS

The G allele of rs1323556 was negatively associated with asthma in the additive model (OR 0.74, 95% CI 0.59-0.93) and in the dominant model (OR 0.71, 95% CI 0.53-0.74). The G allele of rs1575464 was also negatively associated with asthma in two genetic models, additive (OR 0.77, 95% CI 0.62-0.96) and dominant (OR 0.73, 95% CI 0.55-0.97). The G allele of rs61735175 was positively associated with asthma severity in the additive model (OR 1.72, 95% CI 1.07-2.77) and in the dominant model (OR 1.77, 95% CI 1.09-2.85). Five SNVs were associated with atopy markers and four SNVs were associated with helminth infections.

CONCLUSION

Polymorphisms in the CYSLTR2 gene are associated with asthma, atopy markers and helminth infection in Brazilian individuals, which may lead to protection or risk for such conditions, however, more studies are needed to evaluate the functional of this variants here in described.

Hypersensitivity reactions to nonsteroidal anti-inflammatory drugs: an update on pharmacogenetics studies

Nonsteroidal anti-inflammatory drugs are the medications most frequently involved in hypersensitivity reactions to drugs. These can be induced by specific immunological and nonimmunological mechanisms, being the latter the most frequent. The nonimmunological mechanism is related to an imbalance of inflammatory mediators, which is aggravated by the cyclooxygenase inhibition. Genetic studies suggest that multiples genes and additional mechanisms might be involved. The proposals of this review is summarize the contribution of variations in genes involved in the arachidonic acid, inflammatory and immune pathways as well as the recent genome-wide association studies findings related to cross-intolerant nonsteroidal anti-inflammatory drugs hypersensitivity reactions. In addition, using integration of different genetic studies, we propose new target genes. This will help to understand the underlying mechanism of these reactions.

Evolutionary aspects of lipoxygenases and genetic diversity of human leukotriene signaling

Leukotrienes are pro-inflammatory lipid mediators, which are biosynthesized via the lipoxygenase pathway of the arachidonic acid cascade. Lipoxygenases form a family of lipid peroxidizing enzymes and human lipoxygenase isoforms have been implicated in the pathogenesis of inflammatory, hyperproliferative (cancer) and neurodegenerative diseases. Lipoxygenases are not restricted to humans but also occur in a large number of pro- and eucaryotic organisms. Lipoxygenase-like sequences have been identified in the three domains of life (bacteria, archaea, eucarya) but because of lacking functional data the occurrence of catalytically active lipoxygenases in archaea still remains an open question. Although the physiological and/or pathophysiological functions of various lipoxygenase isoforms have been studied throughout the last three decades there is no unifying concept for the biological importance of these enzymes. In this review we are summarizing the current knowledge on the distribution of lipoxygenases in living single and multicellular organisms with particular emphasis to higher vertebrates and will also focus on the genetic diversity of enzymes and receptors involved in human leukotriene signaling.

Unraveling the genetic basis of aspirin hypersensitivity in asthma beyond arachidonate pathways

Although aspirin-exacerbated respiratory disease (AERD) has attracted a great deal of attention because of its association with severe asthma, it remains widely under-diagnosed in the asthmatic population. Oral aspirin challenge is the best method of diagnosing AERD, but this is a time-consuming procedure with serious complications in some cases. Thus, development of non-invasive methods for easy diagnosis is necessary to prevent unexpected complications of aspirin use in susceptible patients. For the past decade, many studies have attempted to elucidate the genetic variants responsible for risk of AERD. Several approaches have been applied in these genetic studies. To date, a limited number of biologically plausible candidate genes in the arachidonate and immune and inflammatory pathways have been studied. Recently, a genome-wide association study was performed. In this review, the results of these studies are summarized, and their limitations discussed. In addition to the genetic variants, changes in methylation patterns on CpG sites have recently been identified in a target tissue of aspirin hypersensitivity. Finally, perspectives on application of new genomic technologies are introduced; these will aid our understanding of the genetic pathogenesis of aspirin hypersensitivity in asthma.

New roles of carboxypeptidase E in endocrine and neural function and cancer

Carboxypeptidase E (CPE) or carboxypeptidase H was first discovered in 1982 as an enkephalin-convertase that cleaved a C-terminal basic residue from enkephalin precursors to generate enkephalin. Since then, CPE has been shown to be a multifunctional protein that subserves many essential nonenzymatic roles in the endocrine and nervous systems. Here, we review the phylogeny, structure, and function of CPE in hormone and neuropeptide sorting and vesicle transport for secretion, alternative splicing of the CPE transcript, and single nucleotide polymorphisms in humans. With this and the analysis of mutant and knockout mice, the data collectively support important roles for CPE in the modulation of metabolic and glucose homeostasis, bone remodeling, obesity, fertility, neuroprotection, stress, sexual behavior, mood and emotional responses, learning, and memory. Recently, a splice variant form of CPE has been found to be an inducer of tumor growth and metastasis and a prognostic biomarker for metastasis in endocrine and nonendocrine tumors.

Functional modules, mutational load and human genetic disease

The ability to generate a massive amount of sequencing and genotyping data is transforming the study of human genetic disorders. Driven by such innovation, it is likely that whole exome and whole-genome resequencing will replace regionally focused approaches for gene discovery and clinical testing in the next few years. However, this opportunity brings a significant interpretative challenge to assigning function and phenotypic variance to common and rare alleles. Understanding the effect of individual mutations in the context of the remaining genomic variation represents a major challenge to our interpretation of disease. Here, we discuss the challenges of assigning mutation functionality and, drawing from the examples of ciliopathies as well as cohesinopathies and channelopathies, discuss possibilities for the functional modularization of the human genome. Functional modularization in addition to the development of physiologically relevant assays to test allele functionality will accelerate our understanding of disease architecture and enable the use of genome-wide sequence data for disease diagnosis and phenotypic prediction in individuals.