Cytokine profiles in cord blood in relation to prenatal traffic-related air pollution: The NELA cohort

BACKGROUND

Outdoor air pollution may disturb immune system development. We investigated whether gestational exposure to traffic-related air pollutants (TRAP) is associated with unstimulated cytokine profiles in newborns.

METHODS

Data come from 235 newborns of the NELA cohort. Innate response-related cytokines (IL-6, IFN-α, IL1-β, and TNF-α), Th1-related (IFN-γ and IL-2), Th2-related (IL-4, IL-5, and IL-13), Th17-related (IL-17 and IL-23), and immunomodulatory cytokine IL-10 were quantified in the supernatant of unstimulated whole umbilical cord blood cells after 7 days of culture using the Luminex technology. Dispersion/chemical transport modeling was used to estimate long-term (whole pregnancy and trimesters) and short-term (15 days before delivery) residential exposures to traffic-related nitrogen dioxide (NO₂ ), particulate matter (PM_2.5 and PM₁₀ ), and ozone (O₃ ). We fitted multivariable logistic regression, Bayesian kernel machine regression (BKMR), and weighted quantile sum (WQS) regression models.

RESULTS

NO₂ during the whole pregnancy increased the odds of detection of IL-1β (OR per 10 µg/m³ increase = 1.37; 95% CI, 1.02, 1.85) and IL-6 (OR per 10 µg/m³ increase = 1.32; 95% CI 1.00, 1.75). Increased odds of detected concentrations of IL-10 was found in newborns exposed during whole pregnancy to higher levels of NO₂ (OR per 10 µg/m³ increase = 1.30; 95% CI 0.99, 1.69), PM₁₀ (OR per 10 µg/m³ increase = 1.49; 95% CI 0.95, 2.33), and PM_2.5 (OR per 5 µg/m³ increase = 1.56; 95% CI 0.97, 2.51). Exposure to O₃ during the whole pregnancy increased the odds of detected IL-13 (OR per 10 µg/m³ increase = 1.22; 95% CI 1.01, 1.49). WQS model revealed first and third trimesters of gestation as windows of higher susceptibility.

CONCLUSIONS

Gestational exposure to TRAP may increase detection of pro-inflammatory, Th2-related, and T regulatory cytokines in newborns. These changes might influence immune system responses later in life.

Modeling of the biotransformation of crotonobetaine into L-(-)-carnitine by Escherichia coli strains

A simple unstructured model, which includes carbon source as the limiting and essential substrate and oxygen as an enhancing substrate for cell growth, has been implemented to depict cell population evolution of two Escherichia coli strains and the expression of their trimethylammonium metabolism in batch and continuous reactors. Although the model is applied to represent the trans-crotonobetaine to L-(-)-carnitine biotransformation, it is also useful for understanding the complete metabolic flow of trimethylammonium compounds in E. coli. Cell growth and biotransformation were studied in both anaerobic and aerobic conditions. For this reason we derived equations to modify the specific growth rate, mu, and the cell yield on the carbon source (glycerol), Y(xg), as oxygen increased the rate of growth. Inhibition functions representing an excess of the glycerol and oxygen were included to depict cell evolution during extreme conditions. As a result, the model fitted experimental data for various growth conditions, including different carbon source concentrations, initial oxygen levels, and the existence of a certain degree of cell death. Moreover, the production of enzymes involved within the E. coli trimethylammonium metabolism and related to trans-crotonobetaine biotransformation was also modeled as a function of both the cell and oxygen concentrations within the system. The model describes all the activities of the different enzymes within the transformed and wild strains, able to produce L-(-)-carnitine from trans-crotonobetaine under both anaerobic and aerobic conditions. Crotonobetaine reductase inhibition by either oxygen or the addition of fumarate as well as its non-reversible catalytic action was taken into consideration. The proposed model was useful for describing the whole set of variables under both growing and resting conditions. Both E. coli strains within membrane high-density reactors were well represented by the model as results matched the experimental data.

Partial alpha-sarcoglycan deficiency with retention of the dystrophin-glycoprotein complex in a LGMD2D family

In patients with sarcoglycan (SG) deficiency, a primary defect in any one of the four SG proteins usually leads to reduced expression of the whole SG complex. We report a limb-girdle muscular dystrophy type 2D family (LGMD2D), with variable phenotype, where a mutation in the alpha-SG gene resulted in the partial deficiency of alpha-SG alone. The normal expression of the other three SG proteins suggests that mutations close to the alpha-SG transmembrane domain might be less critical for complex integrity, and that weakness may occur despite its retention.

Paternal inheritance or different mutations in maternally related patients occur in about 3% of Duchenne familial cases

Duchenne dystrophy (DMD) is an X-linked lethal condition which affects 1 in 3,500 boys. The DMD gene is deleted in about 60-65% of patients while in the remaining 35-40% the condition is caused by point mutations, small insertions, or duplications. We have ascertained 967 DMD families (680 isolated and 287 familial cases). Screening for deletions showed a molecular deletion in 383 among 615 (62.3%) analyzed cases. However, 10 families were unusual: In 7 of them, 2 or more DMD patients were related through paternal lines while in 3 others, affected boys related through maternal lines carried different mutations or originated through independent new mutation events. The finding of 10 atypical genealogies, which represent about 1% of the sample (10/967) or about 3% of familial cases (10/287) is higher than we would expect by chance. Even so, it is an underestimate because screening of mutations in all the affected DMD relatives from each genealogy is not done in many of the familial cases. It suggests that other mechanisms (such as transposon-like elements, for example) could be responsible for a higher genomic instability leading to novel mutations as reported previously by us and others in DMD and in other genetic disorders such as hemophilia and inherited peripheral neuropathies. On the other hand, it shows the importance of testing all affected patients within each genealogy to prevent possible mistakes in carrier detection, genetic counseling, and prenatal diagnosis.

The sarcoglycan complex in the six autosomal recessive limb-girdle muscular dystrophies

To enhance our understanding of the autosomal recessive limb-girdle muscular dystrophy (LGMD), patients from six genetically distinct forms (LGMD2A to LGMD2F) were studied with antibodies directed against four sarcoglycan subunits (alpha-, beta-, gamma-, delta-SG), dystrophin, beta-dystroglycan (beta-DG) and merosin. All patients with LGMD2A and 2B had a mild clinical course while those with a primary sarcoglycan mutation (LGMD2C to 2F) had a range of clinical severity. Dystrophin and merosin immunofluorescence pattern was positive in patients with all six AR LGMDs. The majority of patients with a severe Duchenne-like phenotype presented total absence of the SG complex. However, some exceptions were found in 13q linked patients, indicating that the presence of a certain labelling for components of the SG may not be prognostic for a milder phenotype. The observation that the primary absence of alpha-SG results in the total absence of beta- and delta-SG but not of gamma-SG suggests that the alpha-, beta- and delta-subunits of sarcoglycan may be more closely associated. A secondary reduction in dystrophin amount was seen in patients with primary sarcoglycan mutations, which was most marked in patients with primary beta-, gamma- and delta-SG deficiencies. In contrast, beta-DG staining was retained in all patients, suggesting that the association between SG and DG subcomplexes is not so strong. Based on the above findings, we have refined the model for the interaction among the known glycoproteins of the sarcoglycan complex, within the DGC.

Evidence for a class 4 effect of cibenzoline "in vivo"

In anesthetized dogs, it has already been shown that cibenzoline (4 mg/kg i.v.) possesses class 1 anti-arrhythmic properties. In this work, the cardiac electrophysiologic effects of cibenzoline (1 mg/kg i.v.) were studied before and after propranolol (0.2 mg/kg i.v.) treatment. Cibenzoline caused a slight tachycardia, a reduction of conduction velocity in the His-Purkinje system and in the ventricle, but no significant effects in the atria and the atrioventricular node were detected. On the contrary, when dogs were given the beta-adrenoceptor blocking agent propranolol, cibenzoline produced major effects in the slow response structures, especially in the sinus node and the atrioventricular node (bradycardia and depression of the atrioventricular nodal conduction). No further effects were observed on the His-Purkinje system and ventricle as compared to administration of cibenzoline alone. In dogs, cibenzoline given i.v., had no effects on the slow response systems, probably because of sympathetic nervous system intervention since the class 4 effects of cibenzoline appeared after beta-adrenoceptor blockade.