Effects of BMI,Fat Mass,and Lean Mass on Asthma in Childhood: A Mendelian Randomization Study

Background

Observational studies have reported associations between body mass index (BMI) and asthma, but confounding and reverse causality remain plausible explanations. We aim to investigate evidence for a causal effect of BMI on asthma using a Mendelian randomization approach.

Methods and Findings

We used Mendelian randomization to investigate causal effects of BMI, fat mass, and lean mass on current asthma at age 7½ y in the Avon Longitudinal Study of Parents and Children (ALSPAC). A weighted allele score based on 32 independent BMI-related single nucleotide polymorphisms (SNPs) was derived from external data, and associations with BMI, fat mass, lean mass, and asthma were estimated. We derived instrumental variable (IV) estimates of causal risk ratios (RRs). 4,835 children had available data on BMI-associated SNPs, asthma, and BMI. The weighted allele score was strongly associated with BMI, fat mass, and lean mass (all p-values<0.001) and with childhood asthma (RR 2.56, 95% CI 1.38–4.76 per unit score, p = 0.003). The estimated causal RR for the effect of BMI on asthma was 1.55 (95% CI 1.16–2.07) per kg/m², p = 0.003. This effect appeared stronger for non-atopic (1.90, 95% CI 1.19–3.03) than for atopic asthma (1.37, 95% CI 0.89–2.11) though there was little evidence of heterogeneity (p = 0.31). The estimated causal RRs for the effects of fat mass and lean mass on asthma were 1.41 (95% CI 1.11–1.79) per 0.5 kg and 2.25 (95% CI 1.23–4.11) per kg, respectively. The possibility of genetic pleiotropy could not be discounted completely; however, additional IV analyses using FTO variant rs1558902 and the other BMI-related SNPs separately provided similar causal effects with wider confidence intervals. Loss of follow-up was unlikely to bias the estimated effects.

Conclusions

Higher BMI increases the risk of asthma in mid-childhood. Higher BMI may have contributed to the increase in asthma risk toward the end of the 20th century. Please see later in the article for the Editors'' Summary     

Differentiation of Bacillus pumilus and Bacillus safensis Using MALDI-TOF-MS

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) despite being increasingly used as a method for microbial identification, still present limitations in which concerns the differentiation of closely related species. Bacillus pumillus and Bacillus safensis, are species of biotechnological and pharmaceutical significance, difficult to differentiate by conventional methodologies. In this study, using a well-characterized collection of B. pumillus and B. safensis isolates, we demonstrated the suitability of MALDI-TOF-MS combined with chemometrics to accurately and rapidly identify them. Moreover, characteristic species-specific ion masses were tentatively assigned, using UniProtKB/Swiss-Prot and UniProtKB/TrEMBL databases and primary literature. Delineation of B. pumilus (ions at m/z 5271 and 6122) and B. safensis (ions at m/z 5288, 5568 and 6413) species were supported by a congruent characteristic protein pattern. Moreover, using a chemometric approach, the score plot created by partial least square discriminant analysis (PLSDA) of mass spectra demonstrated the presence of two individualized clusters, each one enclosing isolates belonging to a species-specific spectral group. The generated pool of species-specific proteins comprised mostly ribosomal and SASPs proteins. Therefore, in B. pumilus the specific ion at m/z 5271 was associated with a small acid-soluble spore protein (SASP O) or with 50S protein L35, whereas in B. safensis specific ions at m/z 5288 and 5568 were associated with SASP J and P, respectively, and an ion at m/z 6413 with 50S protein L32. Thus, the resulting unique protein profile combined with chemometric analysis, proved to be valuable tools for B. pumilus and B. safensis discrimination, allowing their reliable, reproducible and rapid identification.     

Matrix metalloproteinase inhibition attenuates right ventricular dysfunction and improves responses to dobutamine during acute pulmonary thromboembolism

Activated matrix metalloproteinases (MMPs) cause cardiomyocyte injury during acute pulmonary thromboembolism (APT). However, the functional consequences of this alteration are not known. We examined whether doxycycline (a MMP inhibitor) improves right ventricle function and the cardiac responses to dobutamine during APT. APT was induced with autologous blood clots (350 mg/kg) in anaesthetized male lambs pre‐treated with doxycycline (Doxy, 10 mg/kg/day, intravenously) or saline. Non‐embolized control lambs received doxycycline pre‐treatment or saline. The responses to intravenous dobutamine (Dob, 1, 5, 10 μg/kg/min.) or saline infusions at 30 and 120 min. after APT induction were evaluated by echocardiography. APT increased mean pulmonary artery pressure and pulmonary vascular resistance index by ~185%. Doxycycline partially prevented APT‐induced pulmonary hypertension (P < 0.05). RV diameter increased in the APT group (from 10.7 ± 0.8 to 18.3 ± 1.6 mm, P < 0.05), but not in the Doxy+APT group (from 13.3 ± 0.9 to 14.4 ± 1.0 mm, P > 0.05). RV dysfunction on stress echocardiography was observed in embolized lambs (APT+Dob group) but not in embolized animals pre‐treated with doxycycline (Doxy+APT+Dob). APT increased MMP‐9 activity, oxidative stress and gelatinolytic activity in the RV. Although doxycycline had no effects on RV MMP‐9 activity, it prevented the increases in RV oxidative stress and gelatinolytic activity (P < 0.05). APT increased serum cardiac troponin I concentrations (P < 0.05), doxycycline partially prevented this alteration (P < 0.05). We found evidence to support that doxycycline prevents RV dysfunction and improves the cardiac responses to dobutamine during APT.     

MitoTimer

Fluorescent Timer, or DsRed1-E5, is a mutant of the red fluorescent protein, dsRed, in which fluorescence shifts over time from green to red as the protein matures. This molecular clock gives temporal and spatial information on protein turnover. To visualize mitochondrial turnover, we targeted Timer to the mitochondrial matrix with a mitochondrial-targeting sequence (coined “MitoTimer”) and cloned it into a tetracycline-inducible promoter construct to regulate its expression. Here we report characterization of this novel fluorescent reporter for mitochondrial dynamics. Tet-On HEK 293 cells were transfected with pTRE-tight-MitoTimer and production was induced with doxycycline (Dox). Mitochondrial distribution was demonstrated by fluorescence microscopy and verified by subcellular fractionation and western blot analysis. Dox addition for as little as 1 h was sufficient to induce MitoTimer expression within 4 h, with persistence in the mitochondrial fraction for up to 6 d. The color-specific conformation of MitoTimer was stable after fixation with 4% paraformaldehyde. Ratiometric analysis of MitoTimer revealed a time-dependent transition from green to red over 48 h and was amenable to analysis by fluorescence microscopy and flow cytometry of whole cells or isolated mitochondria. A second Dox administration 48 h after the initial induction resulted in a second round of expression of green MitoTimer. The extent of new protein incorporation during a second pulse was increased by administration of a mitochondrial uncoupler or simvastatin, both of which trigger mitophagy and biogenesis. MitoTimer is a novel fluorescent reporter protein that can reveal new insights into mitochondrial dynamics within cells. Coupled with organelle flow cytometry, it offers new opportunities to investigate mitochondrial subpopulations by biochemical or proteomic methods.     

Genetic diversity, structure and conservation of the endangered Cantabrian Capercaillie in a unique peripheral habitat

Populations at the rear edge of the species’ range are often at a high risk of extinction due to their isolation, fragmentation and small population sizes. However, these populations also play a relevant role in the conservation of biodiversity since they may represent a valuable genetic resource. The endangered Cantabrian Capercaillie (Tetrao urogallus cantabricus) inhabits deciduous forests of the Cantabrian Mountains of Spain, at the southwestern limit of the species’ range. Recently, nine Cantabrian Capercaillie leks were discovered in Pyrenean oak forests of the southern slope of the Cantabrian range, where the subspecies historically occurred. To elucidate if the origin of this peripheral population nucleus is the result of a historical range contraction or a recent re-colonization from the core population, we sampled moulted feathers from all the known leks in the southern peripheral forests and from the adjacent main core population, based on nine microsatellite loci genotypes. No significant genetic differentiation was detected between main core and peripheral forests suggesting that gene flow is not interrupted between these nuclei. Contrary to expected, peripheral forests did not represent sink populations, since gene flow mainly occurred from southern peripheral to northern main core forests. Therefore, the origin of these birds inhabiting the peripheral nucleus seems not to be a recent colonization but relicts from the former distribution range that have remained unnoticed in a drier and warmer environment than described so far for the species. Cantabrian Capercaillie faces a high risk of extinction in the southernmost forests of its distribution, not only because of its peripheral location but also due to its small population size, low genetic diversity and low incoming gene flow. According to our results, this peripheral nucleus could represent an expanding edge for the population if Pyrenean oak forests continue to spread out southwards and consequently stress the need for conservation programs to preserve habitat availability and forest connectivity.     

Behavioral and neurochemical changes in the zebrafish leopard strain

The zebrafish leopard phenotype (leo) displays abnormal pigmentation and shows increased anxiety‐like behavior. The neurochemical changes associated with this anxious phenotype are not known. Here, we demonstrate that leo show increased anxiety‐like behavior in the light/dark box and in the novel tank test. This anxious phenotype is rescued by acute treatment with a dose of a serotonin reuptake inhibitor, fluoxetine, that is inactive in wild‐type animals. Moreover, leo show decreased tissue levels of serotonin, increased serotonin turnover and slightly increased monoamine oxidase activity. These results suggest that the anxious phenotype observed in leo zebrafish is caused by a decrease in serotonin uptake. This work could open an important avenue in defining the neurochemical underpinning of natural variation in anxiety disorders .     

Redescription of Notarius grandicassis and Notarius parmocassis (Siluriformes; Ariidae), with insights into morphological plasticity and evidence of incipient speciation

The Thomas sea catfish is characterized by a highly variable parietosupraoccipital process, which has been recognized as intraspecific variation or phenotypic plasticity. On the basis of this variation, three nominal species have been described, with two of them currently considered to be junior synonyms. Here, the Notarius grandicassis species complex is reviewed, considering the geographic variation of its morphological traits. Notarius grandicassis from north-eastern South America, and Notarius parmocassis, from eastern and southern Brazil, are redescribed as distinct evolutionary units, even though they are not differentiated by partial sequences of the mitochondrial genes CytB and ATPase 8/6. This condition is interpreted as a consequence of the recent evolutionary history of these species, which are found in distinct geographic areas with different environmental conditions.     

The ZC3HC1 rs11556924 polymorphism is associated with increased carotid intima-media thickness in patients with rheumatoid arthritis

Introduction

Rheumatoid arthritis (RA) is a complex polygenic disease associated with chronic inflammation, accelerated atherosclerosis and increased cardiovascular (CV) mortality. A recent meta-analysis has described the ZC3HC1 rs11556924 polymorphism as one of the most important signals associated with coronary artery disease (CAD) in non-rheumatic Caucasian individuals. In this study we evaluated the potential association of this gene polymorphism with subclinical atherosclerosis assessed by the evaluation of carotid intima-media thickness (cIMT) in RA patients.

Methods

This study included 502 RA patients from Northern Spain. The ZC3HC1 rs11556924 polymorphism was genotyped with TaqMan single-nucleotide polymorphism (SNP) genotyping assays (C__31283062_10) in a 7900HT real-time polymerase chain reaction (PCR) system. cIMT was also assessed in these patients by carotid ultrasonography (US) technology.

Results

RA patients carrying the TT genotype had significantly higher cIMT values than those homozygous for the CC genotype (mean ± standard deviation (SD): 0.76 ± 0.18 mm and mean ± SD: 0.71 ± 0.16 mm respectively; P = 0.03) even after adjusting the results for sex, age at the time of US study, follow-up time and traditional CV risk factors (P = 0.04) evidencing that the effect conferred by ZC3HC1 rs11556924 polymorphism is independent of the traditional CV risk factors.

Conclusion

Our results indicate that ZC3HC1 rs11556924 polymorphism is associated with subclinical atherosclerosis in RA.     

Binding of Sulfamethazine to β-cyclodextrin and Methyl-β-cyclodextrin

β-cyclodextrin (βCD) and methyl-β-cyclodextrin (MβCD) complexes with sulfamethazine (SMT) were prepared and characterized by different experimental techniques, and the effects of βCD and MβCD on drug solubility were assessed via phase-solubility analysis. The phase-solubility diagram for the drug showed an increase in water solubility, with the following affinity constants calculated: 40.4 ± 0.4 (pH 2.0) and 29.4 ± 0.4 (pH 8.0) M⁻¹ with βCD and 56 ± 1 (water), 39 ± 3 (pH 2.0) and 39 ± 5 (pH 8.0) M⁻¹ with MβCD. According to ¹H NMR and 2D NMR spectroscopy, the complexation mode involved the aromatic ring of SMT included in the MβCD cavity. The complexes obtained in solid state by freeze drying were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and thermal analysis. The amorphous complexes obtained in this study may be useful in the preparation of pharmaceutical dosage forms of SMT.