Genetic variants in RORA are associated with asthma and allergy markers in an admixed population

Understanding and controlling asthma in Latin America: A review of recent research informed by the SCAALA programme

Asthma is an important health concern in Latin America (LA) where it is associated with variable prevalence and disease burden between countries. High prevalence and morbidity have been observed in some regions, particularly marginalized urban populations. Research over the past 10 years from LA has shown that childhood disease is primarily non-atopic. The attenuation of atopy may be explained by enhanced immune regulation induced by intense exposures to environmental factors such as childhood infections and poor environmental conditions of the urban poor. Non-atopic symptoms are associated with environmental and lifestyle factors including poor living conditions, respiratory infections, psychosocial stress, obesity, and a diet of highly processed foods. Ancestry (particularly African) and genetic factors increase asthma risk, and some of these factors may be specific to LA settings. Asthma in LA tends to be poorly controlled and depends on access to health care and medications. There is a need to improve management and access to medication through primary health care. Future research should consider the heterogeneity of asthma to identify relevant endotypes and underlying causes. The outcome of such research will need to focus on implementable strategies relevant to populations living in resource-poor settings where the disease burden is greatest.

Maresin-1 and Its Receptors RORα/LGR6 as Potential Therapeutic Target for Respiratory Diseases

Maresin-1 is one of the representative specialized pro-resolving mediators that has shown beneficial effects in inflammatory disease models. Recently, two distinct types of receptor molecules were discovered as the targets of maresin-1, further revealing the pro-resolution mechanism of maresin-1. One is retinoic acid-related orphan receptor α (RORα) and the another one is leucine-rich repeat domain-containing G protein-coupled receptor 6 (LGR6). In this review, we summarized the detailed role of maresin-1 and its two different receptors in respiratory diseases. RORα and LGR6 are potential targets for the treatment of respiratory diseases. Future basic research and clinical trials on MaR1 and its receptors should provide useful information for the treatment of respiratory diseases.

High retinoic acid receptor-related orphan receptor A gene expression in peripheral blood leukocytes may be related to acute myocardial infarction

OBJECTIVE

This study aimed to investigate whether differential expression of the retinoic acid receptor-related orphan receptor A (RORA) gene is related to occurrence of acute myocardial infarction (AMI).

METHODS

This was a retrospective study. White blood cells of 93 patients with acute myocardial infarction and 74 patients with stable coronary artery disease were collected. Reverse transcription quantitative polymerase chain reaction and western blotting were used to measure RORA mRNA and protein expression, respectively.

RESULTS

RORA mRNA expression levels in peripheral blood leukocytes in patients with AMI were 1.57 times higher than those in patients with stable coronary artery disease. Protein RORA levels in peripheral blood of patients with AMI were increased. Binary logistic regression analysis showed that high expression of RORA was an independent risk factor for AMI, and it increased the risk of AMI by 2.990 times.

CONCLUSION

RORA expression levels in patients with AMI is significantly higher than that in patients with stable coronary artery disease. High expression of RORA is related to AMI and it may be an independent risk factor for AMI.

New variants in NLRP3 inflammasome genes increase risk for asthma and Blomia tropicalis-induced allergy in a Brazilian population

Atopic asthma is a chronic lung disease of lower airways caused mainly due to action of T-helper (Th) 2 type cytokines, eosinophilic inflammation, mucus hypersecretion and airway remodelling. Interleukin (IL)-33 increases type 2 immunity polarization in airway playing critical role in eosinophilic asthma. On the other hand, NLRP3 inflammasome activation results in the release of caspase-1 (Casp-1) which, in its turn, promotes IL-33 inactivation. Recent studies have shown associations between NLRP3 variants and inflammatory diseases. However, no study with genes in NLRP3 inflammassome route has been conducted so far with asthma and atopy in any population to date. Blood samples were collected from 1246 asthmatic and non-asthmatic children. Associations were tested for single nucleotide polymorphism (SNP)s in NLRP3 and CASP1 with asthma and markers of atopy and in cultures stimulated with Blomia tropicalis (Bt) mite crude extract. The T allele of rs4925648 (NLRP3) was associated with increased asthma risk (OR 1.50, P = 0.005). In addition, the T allele of rs12130711 polymorphism, whithin the same gene, acted as a protector factor for asthma (OR 0.78, P = 0.038). On the other hand, the C allele of rs4378247 NLRP3 variant was associated with lower levels of IL-13 production when peripheral blood cells were stimulated with Bt (OR 0.39, P = 4E-04). In addition, the greater the number of risk alleles in IL33/NLRP3/CASP1 route the greater was the risk for asthma. The T allele of rs7925706 CASP1 variant was also associated with increased risk for asthma (OR 1.47, P = 0.008). In addition, this same allele increased the eosinophil counts in blood (mm3) in asthmatic individuals compared with non-asthmatic (P = 0.0004). These results suggest that NLRP3 and CASP1 polymorphisms may be associated with susceptibility for asthma and markers of atopy in our population.

The Cytokines of Asthma

Asthma is a chronic inflammatory airway disease associated with type 2 cytokines interleukin-4 (IL-4), IL-5, and IL-13, which promote airway eosinophilia, mucus overproduction, bronchial hyperresponsiveness (BHR), and immunogloubulin E (IgE) synthesis. However, only half of asthma patients exhibit signs of an exacerbated Type 2 response. "Type 2-low" asthma has different immune features: airway neutrophilia, obesity-related systemic inflammation, or in some cases, few signs of immune activation. Here, we review the cytokine networks driving asthma, placing these in cellular context and incorporating insights from cytokine-targeting therapies in the clinic. We discuss established and emerging paradigms in the context of the growing appreciation of disease heterogeneity and argue that the development of new and improved therapeutics will require understanding the diverse mechanisms underlying the spectrum of asthma pathologies.

Association study in African-admixed populations across the Americas recapitulates asthma risk loci in non-African populations

Asthma is a complex disease with striking disparities across racial and ethnic groups. Despite its relatively high burden, representation of individuals of African ancestry in asthma genome-wide association studies (GWAS) has been inadequate, and true associations in these underrepresented minority groups have been inconclusive. We report the results of a genome-wide meta-analysis from the Consortium on Asthma among African Ancestry Populations (CAAPA; 7009 asthma cases, 7645 controls). We find strong evidence for association at four previously reported asthma loci whose discovery was driven largely by non-African populations, including the chromosome 17q12-q21 locus and the chr12q13 region, a novel (and not previously replicated) asthma locus recently identified by the Trans-National Asthma Genetic Consortium (TAGC). An additional seven loci reported by TAGC show marginal evidence for association in CAAPA. We also identify two novel loci (8p23 and 8q24) that may be specific to asthma risk in African ancestry populations.