ADRB2 and ADCY9 Sequence Variations in Brazilian Asthmatic Patients.

Asthma is a chronic inflammatory respiratory condition, characterized by variable airflow limitation, leading to clinical symptoms such as dyspnea and chest tightness. These symptoms result from an underlying inflammatory process. The ß2 agonists are bronchodilators prescribed for the relief of the disease. Nevertheless, their efficacy exhibits substantial interindividual variability. Currently, there is widespread recognition of the association between specific genetic variants, predominantly located within the ADRB2 and ADCY9 genes and their efficacy. This association, usually represented by the presence of non-synonymous single nucleotide polymorphisms (SNPs) have a strong impact in the protein functionality. The prevalence of these mutations varies based on the ethnic composition of the population and thus understanding the profiles of variability in different populations would contribute significantly to standardizing the use of these medications. In this study, we conducted a sequence-based genotyping of the relevant SNPs within the ADRB2 and ADCY9 genes in patients undergoing treatment with bronchodilators and/or corticosteroids at two healthcare facilities in the state of Rio de Janeiro, Brazil. We investigated the presence of c.46A>G, c.79C>G, c.252G>A, and c.491C>T SNPs within the ADRB2, and c.1320018 A>G within the ADCY9. Our results were in line with existing literature data with both for individuals in Brazil and Latin American.

Genetic profile of the arylamine N-acetyltransferase 2 coding gene among individuals from two different regions of Brazil.

Arylamine N-acetyltranferase 2 is the main enzyme responsible for the isoniazid metabolization into hepatotoxic intermediates and the degree of hepatotoxicity severity has been attributed to genetic variability in the NAT2 gene. The main goal of this study was to describe the genetic profile of the NAT2 gene in individuals from two different regions of Brazil: Rio de Janeiro and Goiás States. Therefore, after preparation of DNA samples from 404 individuals, genotyping of the coding region of NAT2 was performed by direct PCR sequencing. Thirteen previously described SNPs were detected in these Brazilian populations, from which seven: 191 G>A; 282 C>T; 341 T>C; 481 C>T; 590 G>A; 803 A>G and 857 G>A are the most frequent in other populations. The presence of so-called ethnic-specific SNPs in our population is in accordance with the Brazilians' multiple ancestry. Upon allele and genotype analysis, the most frequent NAT2 alleles were respectively NAT2*5B (33%), NAT2*6A (26%) and NAT2*4 (20%) being NAT2*5/*5 the more prevalent genotype (31.7%). These results clearly demonstrate the predominance in the studied Brazilian groups of NAT2 alleles associated with slow over the fast and intermediate acetylator genotypes. Additionally, in Rio de Janeiro, a significantly higher frequency of intermediate acetylation status was found when compared to Goiás (42.5% versus 25%) (p=0.05), demonstrating that different regions of a country with a population characterized by a multi-ethnic ancestry may present a large degree of variability in NAT2 allelic frequencies. This finding has implications in the determination of nationwide policies for use of appropriate anti-TB drugs.

Comparative evaluation of Mycobacterium vaccae as a surrogate cloning host for use in the study of mycobacterial genetics.

Mycobacterium vaccae represents an alternative mycobacterial cloning host that has been largely overlooked to date. The main reason for this may be the reported non-transformability of this species, specifically the so-called Stanford strain (NCTC 11659), with expression vectors that use kanamycin resistance as a selection method. However, this strain can be transformed using hygromycin resistance as an alternative selectable phenotype. The present study has shown that in contrast to previous reports, M. vaccae (ATCC 15483) is capable of being transformed with a range of vectors encoding kanamycin resistance as the selectable marker. Thereafter, the expression of the lacZ reporter gene in M. vaccae, Mycobacterium bovis BCG and Mycobacterium smegmatis mc(2)155 was evaluated using a range of characterized mycobacterial promoter sequences (hsp60, hsp70, PAN, 18kDa and 16S rRNA) cloned in the same promoter probe vector. In general, the promoters showed similar levels of activity in the three species, demonstrating that existing expression systems can readily be employed with M. vaccae (ATCC 15483). This was further confirmed by the observation that M. vaccae was capable of stable, in vitro expression of recombinant S1 subunit of pertussis toxin at levels equivalent to those obtained with BCG and M. smegmatis. Analysis of structural and functional stability of a range of vectors demonstrated that the incidence of instability noted for M. vaccae was lower than that recorded for M. smegmatis. Taken together, the results indicate that M. vaccae is an additional cloning host which may prove useful for specific aspects of mycobacterial biology and provide increased flexibility to the field of recombinant protein technology for mycobacteria.