Farm exposure and time trends in early childhood may influence DNA methylation in genes related to asthma and allergy

BACKGROUND

Genetic susceptibility and environmental influences are important contributors to the development of asthma and atopic diseases. Epigenetic mechanisms may facilitate gene by environment interactions in these diseases.

METHODS

We studied the rural birth cohort PASTURE (Protection against allergy: study in rural environments) to investigate (a) whether epigenetic patterns in asthma candidate genes are influenced by farm exposure in general, (b) change over the first years of life, and (c) whether these changes may contribute to the development of asthma. DNA was extracted from cord blood and whole blood collected at the age of 4.5 years in 46 samples per time point. DNA methylation in 23 regions in ten candidate genes (ORMDL1, ORMDL2, ORMDL3, CHI3L1, RAD50, IL13, IL4, STAT6, FOXP3, and RUNX3) was assessed by pyrosequencing, and differences between strata were analyzed by nonparametric Wilcoxon-Mann-Whitney tests.

RESULTS

In cord blood, regions in ORMDL1 and STAT6 were hypomethylated in DNA from farmers' as compared to nonfarmers' children, while regions in RAD50 and IL13 were hypermethylated (lowest P-value (STAT6) = 0.001). Changes in methylation over time occurred in 15 gene regions (lowest P-value (IL13) = 1.57*10(-8)). Interestingly, these differences clustered in the genes highly associated with asthma (ORMDL family) and IgE regulation (RAD50, IL13, and IL4), but not in the T-regulatory genes (FOXP3, RUNX3).

CONCLUSIONS

In this first pilot study, DNA methylation patterns change significantly in early childhood in specific asthma- and allergy-related genes in peripheral blood cells, and early exposure to farm environment seems to influence methylation patterns in distinct genes.

[Rivaroxaban: Xarelto--recommendations for pharmacists]

Rivaroxaban is one of the new oral anticoagulants (NOACs). It has many potential advantages in comparison with Vitamin K Antagonists (VKA). It has a predictable anticoagulant effect and does not theoretically require biological monitoring. It is also characterized by less food and drug interactions. However, due to major risks associated with over- and under-dosage, its optimal use in patients should be carefully followed by health care professionals. The aim of this article is to provide recommendations for pharmacists on the practical use of Xarelto in its different approved indications. This document is adapted from the practical user guide of rivaroxaban which was developed by an independent group of Belgian experts in the field of thrombosis and haemostasis.

Retinoic Acid receptor-gamma-selective retinoids exert antiproliferative effects on human-melanoma cell-growth in-vitro

Malignant melanoma is a cancer with dramatically increasing incidence and mortality. Alternative approaches for therapy of disseminated malignant melanoma are urgently needed. In order to develop new alternatives for therapy of metastatic melanoma, we tested the biological activity of eight synthetic retinoids with high affinity and/or selectivity for the retinoic acid receptors (RAR) alpha, beta and gamma in comparison to all-trans retinoic acid, arotinoid acid and CD 367 in four human melanoma cell lines. The melanoma cell growth was not affected by most retinoids tested, however, two of the synthetic substances with high RAR-gamma selectivity (CD 437 and CD 2325) showed a dose-dependent antiproliferative effect on all melanoma cell lines tested with IC50 values between 10(-6) and 10(-7) M. A structurally closely related compound, CD 2398, lacking the carboxyl-terminal group and therefore exhibited no RAR-binding did not change melanoma cell growth behaviour. We demonstrate the expression of RAR-alpha, RAR-beta and RAR-gamma, in four human melanoma cell lines by polymerase chain reaction. Taken together, these results suggest that binding and stimulation of the RAR-gamma receptor might be a major factor in growth inhibition of human melanoma cell by retinoids in vitro. Although several of the compounds altered the cell surface expression of defined melanocytic differentiation markers, the correlation to changes in melanin content was poor. Furthermore, five out of eight retinoids modulated HLA-DR expression on human melanoma cells. The potent growth inhibitory effect of the RAR-gamma selective retinoids as well as their immunomodulating capacities opens an interesting alternative for new antiproliferative and immunomodulatory strategies in the therapy of metastatic melanoma.

Unbiased proteomic analysis of proteins interacting with the HIV-1 5'LTR sequence: role of the transcription factor Meis

To depict the largest picture of a core promoter interactome, we developed a one-step DNA-affinity capture method coupled with an improved mass spectrometry analysis process focused on the identification of low abundance proteins. As a proof of concept, this method was developed through the analysis of 230 bp contained in the 5′long terminal repeat (LTR) of the human immunodeficiency virus 1 (HIV-1). Beside many expected interactions, many new transcriptional regulators were identified, either transcription factors (TFs) or co-regulators, which interact directly or indirectly with the HIV-1 5′LTR. Among them, the homeodomain-containing TF myeloid ectopic viral integration site was confirmed to functionally interact with a specific binding site in the HIV-1 5′LTR and to act as a transcriptional repressor, probably through recruitment of the repressive Sin3A complex. This powerful and validated DNA-affinity approach could also be used as an efficient screening tool to identify a large set of proteins that physically interact, directly or indirectly, with a DNA sequence of interest. Combined with an in silico analysis of the DNA sequence of interest, this approach provides a powerful approach to select the interacting candidates to validate functionally by classical approaches.

[Spontaneous regression of epithelial thymic tumours]

INTRODUCTION

Spontaneous regression of an epithelial thymic tumour has been reported but seems extremely rare. Its mechanism is unknown.

CASE REPORT

We report two cases of epithelial thymic tumour, either histologically proven or highly suspected on imaging, that regressed spontaneously (partially in one patient and totally in the other).

CONCLUSION

Spontaneous regression of an epithelial thymic tumour is very rare but this possibility could lead to clinical and radiological monitoring rather than surgery in selected patients.

MeQA: a pipeline for MeDIP-seq data quality assessment and analysis

MOTIVATION

We present a pipeline for the pre-processing, quality assessment, read distribution and methylation estimation for methylated DNA immunoprecipitation (MeDIP)-sequence datasets. This is the first MeDIP-seq-specific analytic pipeline that starts at the output of the sequencers. This pipeline will reduce the data analysis load on staff and allows the easy and straightforward analysis of sequencing data for DNA methylation. The pipeline integrates customized scripting and several existing tools, which can deal with both paired and single end data.

AVAILABILITY

The package and extensive documentation, and comparison to public data is available at http://life.tongji.edu.cn/meqa/.

Epigenetic mechanisms and the relationship to childhood asthma

Epigenetic mechanisms mediate genomic adaption to the environment and epigenetic alterations can contribute to the development of disease phenotypes, as can genetic variants. A variety of molecular mechanisms are involved in epigenetic regulation, including post-transcriptional histone modifications, histone variants, ATP-dependent chromatin remodelling complexes, polycomb/trithorax protein complexes, small and other noncoding RNAs (small interfering RNA and micro RNAs) and DNA methylation. Epigenetic mechanisms have been identified in cancer but very little is known about these effects in complex diseases such as asthma. Epigenetic mechanisms have been found to play a primordial role in T-cell differentiation and novel aspects of asthma and allergy development are now investigated by systematic epigenetic studies. Here we give an introduction to epigenetics, review the existing literature in relation to asthma and asthma-related mechanisms and hypothesise on feasible approaches for the study of epigenetics in asthma in the future.