ALDH1A2 (RALDH2) genetic variation in human congenital heart disease.

BACKGROUND: Signaling by the vitamin A-derived morphogen retinoic acid (RA) is required at multiple steps of cardiac development. Since conversion of retinaldehyde to RA by retinaldehyde dehydrogenase type II (ALDH1A2, a.k.a RALDH2) is critical for cardiac development, we screened patients with congenital heart disease (CHDs) for genetic variation at the ALDH1A2 locus. METHODS: One-hundred and thirty-three CHD patients were screened for genetic variation at the ALDH1A2 locus through bi-directional sequencing. In addition, six SNPs (rs2704188, rs1441815, rs3784259, rs1530293, rs1899430) at the same locus were studied using a TDT-based association approach in 101 CHD trios. Observed mutations were modeled through molecular mechanics (MM) simulations using the AMBER 9 package, Sander and Pmemd programs. Sequence conservation of observed mutations was evaluated through phylogenetic tree construction from ungapped alignments containing ALDH8 s, ALDH1Ls, ALDH1 s and ALDH2 s. Trees were generated by the Neighbor Joining method. Variations potentially affecting splicing mechanisms were cloned and functional assays were designed to test splicing alterations using the pSPL3 splicing assay. RESULTS: We describe in Tetralogy of Fallot (TOF) the mutations Ala151Ser and Ile157Thr that change non-polar to polar residues at exon 4. Exon 4 encodes part of the highly-conserved tetramerization domain, a structural motif required for ALDH oligomerization. Molecular mechanics simulation studies of the two mutations indicate that they hinder tetramerization. We determined that the SNP rs16939660, previously associated with spina bifida and observed in patients with TOF, does not affect splicing. Moreover, association studies performed with classical models and with the transmission disequilibrium test (TDT) design using single marker genotype, or haplotype information do not show differences between cases and controls. CONCLUSION: In summary, our screen indicates that ALDH1A2 genetic variation is present in TOF patients, suggesting a possible causal role for this gene in rare cases of human CHD, but does not support the hypothesis that variation at the ALDH1A2 locus is a significant modifier of the risk for CHD in humans.

Oral tolerance attenuates changes in in vitro lung tissue mechanics and extracellular matrix remodeling induced by chronic allergic inflammation in guinea pigs.

Recent studies emphasize the presence of alveolar tissue inflammation in asthma. Immunotherapy has been considered a possible therapeutic strategy for asthma, and its effect on lung tissue had not been previously investigated. Measurements of lung tissue resistance and elastance were obtained before and after both ovalbumin and acetylcholine challenges. Using morphometry, we assessed eosinophil and smooth muscle cell density, as well as collagen and elastic fiber content, in lung tissue from guinea pigs with chronic pulmonary allergic inflammation. Animals received seven inhalations of ovalbumin (1-5 mg/ml; OVA group) or saline (SAL group) during 4 wk. Oral tolerance (OT) was induced by offering ad libitum ovalbumin 2% in sterile drinking water starting with the 1st inhalation (OT1 group) or after the 4th (OT2 group). The ovalbumin-exposed animals presented an increase in baseline and in postchallenge resistance and elastance related to baseline, eosinophil density, and collagen and elastic fiber content in lung tissue compared with controls. Baseline and post-ovalbumin and acetylcholine elastance and resistance, eosinophil density, and collagen and elastic fiber content were attenuated in OT1 and OT2 groups compared with the OVA group. Our results show that inducing oral tolerance attenuates lung tissue mechanics, as well as eosinophilic inflammation and extracellular matrix remodeling induced by chronic inflammation.

Impaired glutathione synthesis in schizophrenia: convergent genetic and functional evidence.

Schizophrenia is a complex multifactorial brain disorder with a genetic component. Convergent evidence has implicated oxidative stress and glutathione (GSH) deficits in the pathogenesis of this disease. The aim of the present study was to test whether schizophrenia is associated with a deficit of GSH synthesis. Cultured skin fibroblasts from schizophrenia patients and control subjects were challenged with oxidative stress, and parameters of the rate-limiting enzyme for the GSH synthesis, the glutamate cysteine ligase (GCL), were measured. Stressed cells of patients had a 26% (P = 0.002) decreased GCL activity as compared with controls. This reduction correlated with a 29% (P < 0.001) decreased protein expression of the catalytic GCL subunit (GCLC). Genetic analysis of a trinucleotide repeat (TNR) polymorphism in the GCLC gene showed a significant association with schizophrenia in two independent case-control studies. The most common TNR genotype 7/7 was more frequent in controls [odds ratio (OR) = 0.6, P = 0.003], whereas the rarest TNR genotype 8/8 was three times more frequent in patients (OR = 3.0, P = 0.007). Moreover, subjects with disease-associated genotypes had lower GCLC protein expression (P = 0.017), GCL activity (P = 0.037), and GSH contents (P = 0.004) than subjects with genotypes that were more frequent in controls. Taken together, the study provides genetic and functional evidence that an impaired capacity to synthesize GSH under conditions of oxidative stress is a vulnerability factor for schizophrenia.

Papel da indução de tolerância oral no remodelamento de vias aéreas e na expressão da óxido nítrico sintase neuronal / Role of oral tolerance induction in airway remodeling and the expression of neuronal nitric oxide syntase

Foram investigados os efeitos de dois modelos de indução de tolerância oral em cobaias com inflamação crônica alérgica pulmonar. A indução de tolerância oral concomitante ao início da sensibilização ou depois de estabelecida a resposta alérgica atenuou a inflamação eosinofílica, os títulos de IgG1 e o remodelamento brônquico. A redução dos linfomononucleares e da hiperresponsividade brônquica foi mais efetiva quando a indução de tolerância foi feita em animais previamente sensibilizados. Houve dissociação entre controle da inflamação eosinofílica e a produção de óxido nítrico exalado, o que sugere um mecanismo novo ativado pela indução de tolerância oral...

The effects of two models of oral tolerance induction were investigated in guinea pigs with allergic pulmonary chronic inflammation. The induction of oral tolerance concomitant with the beginning of sensitization or after the established the allergic response attenuated the eosinophilic inflammation, the IgG1 titles and the airway remodeling. The reduction of lymphomononuclear and bronchial hyperresponsiveness were more effective when the induction of tolerance was made in animals previously sensitized. There was dissociation between the control of the eosinophilic inflammation and the exhaled nitric oxide production, what suggests a new mechanism activated by the induction of oral tolerance...

Efeito da fisioterapia respiratória e na saturaçäo de O2 em pacientes submetidos à ventilaçäo mecânica / Effect of the conventional respiratory physiotherapy and of the aspiration maneuver in resistance of the respiratory system and in O2 saturation in patients submitteds to ventilation

Os primeiros relatos dos benefícios da drenagem postural no tratamento das bronquiectasias datam do início do século XX. Desde entäo, numerosos trabalhos têm sido publicados sobre indicaçöes, técnicas, riscos e benefícios da fisioterapia respisratória. Entretanto näo tem sido avaliado comparativamente os efeitos da fisioterapia respiratória convencional (drenagem postural, percussäo e aspiraçäo) e da manobra de aspiraçäo sobre a resistência do sistema respiratório, e sobre a saturaçäo de O2 (SpO2), motivo pelo qual foi proposto neste estudo a avaliaçäo dos efeitos da FRC e da manobra de aspiraçäo isoladamente nos valores da resistência de SPO2. Foram investigados 12 pacientes, idade média de 58 anos, internados na UTI do HC FMB-UNESP, com insuficiência respiratória em ventilaçäo mecânica. Durante quatro dias, os pacientes foram submetidos de forma alternada a sessöes de aspiraçäo isoladamente e de FRC, documentando-se imediatamente antes e após cada procedimento os valores da resistênciae da SpO2. Observou-se que houve uma diminuiçäo significativa (p< 0,05) da resistência em todos os dias quando se utilizou a FRC. Quando o método utilizado foi o de aspiraçäo, näo houve significância estatística (p> 0,05). Os valores da SpO2 näo se alteraram com o uso da FRC e da aspiraçäo. Esses resultados demonstraram que a FRC é benéfica na melhoria da resistência do sistema respiratório.

Avaliação da resistência e da complacência pulmonar em pacientes entubados na Unidade de Terapia Intensiva / Evalution of the compliance and resistence in intubated patients at the Intensive Care Unit

A análise da resistência do sistema respiratório e da complacência pulmonar é importante para avaliar a gravidade e a evolução da doença. Seus valores dependem da doença pulmonar, do volume pulmonar, fluxo aéreo, condições do sistema respiratório e mecânica torácica. Conclui-se que a avaliação da complacência pulmonar e principalmente da resistência pode ser um guia útil para a vigilância da evolução de pacientes criticamente doentes e entubados