A path forward in the debate over health impacts of endocrine disrupting chemicals

Several recent publications reflect debate on the issue of “endocrine disrupting chemicals” (EDCs), indicating that two seemingly mutually exclusive perspectives are being articulated separately and independently. Considering this, a group of scientists with expertise in basic science, medicine and risk assessment reviewed the various aspects of the debate to identify the most significant areas of dispute and to propose a path forward. We identified four areas of debate. The first is about the definitions for terms such as “endocrine disrupting chemical”, “adverse effects”, and “endocrine system”. The second is focused on elements of hormone action including “potency”, “endpoints”, “timing”, “dose” and “thresholds”. The third addresses the information needed to establish sufficient evidence of harm. Finally, the fourth focuses on the need to develop and the characteristics of transparent, systematic methods to review the EDC literature. Herein we identify areas of general consensus and propose resolutions for these four areas that would allow the field to move beyond the current and, in our opinion, ineffective debate

Fibroblasts from patients with major depressive disorder show distinct transcriptional response to metabolic stressors

Major depressive disorder (MDD) is increasingly viewed as interplay of environmental stressors and genetic predisposition, and recent data suggest that the disease affects not only the brain, but the entire body. As a result, we aimed at determining whether patients with major depression have aberrant molecular responses to stress in peripheral tissues. We examined the effects of two metabolic stressors, galactose (GAL) or reduced lipids (RL), on the transcriptome and miRNome of human fibroblasts from 16 pairs of patients with MDD and matched healthy controls (CNTR). Our results demonstrate that both MDD and CNTR fibroblasts had a robust molecular response to GAL and RL challenges. Most importantly, a significant part (messenger RNAs (mRNAs): 26-33%; microRNAs (miRNAs): 81-90%) of the molecular response was only observed in MDD, but not in CNTR fibroblasts. The applied metabolic challenges uncovered mRNA and miRNA signatures, identifying responses to each stressor characteristic for the MDD fibroblasts. The distinct responses of MDD fibroblasts to GAL and RL revealed an aberrant engagement of molecular pathways, such as apoptosis, regulation of cell cycle, cell migration, metabolic control and energy production. In conclusion, the metabolic challenges evoked by GAL or RL in dermal fibroblasts exposed adaptive dysfunctions on mRNA and miRNA levels that are characteristic for MDD. This finding underscores the need to challenge biological systems to bring out disease-specific deficits, which otherwise might remain hidden under resting conditions

Isolation and characterization of microsatellite loci in the tropical forage legume Stylosanthes guianensis (Aubl.) Sw.

Stylosanthes guianensis is an important tropical pasture legume. Knowledge of genetic diversity and structure of S. guianensis populations is of great importance for the conservation and germplasm management of this species. Thus, 20 microsatellite markers were developed from a S. guianensis enriched library. The microsatellites were characterized in 20 accessions from the germplasm collection of the Empresa Brasileira de Pesquisa Agropecuária (Embrapa). The average number of alleles per locus varied from 2 to 7, with an average of 4 alleles per locus. The observed and expected heterozygosities ranged from 0 to 0.60 and 0.10 to 0.85, respectively. This new set of microsatellites will contribute towards studies of genetic diversity and conservation of S. guianensis. © Springer Science+Business Media B.V. 2009.M. O. Santos, C. T. Karia, R. M. S. Resende, L. Chiari, L. Jungmann, M. I. Zucchi, A. P. Souz

Isolation and characterization of microsatellite loci in the stingless bee Melipona interrupta manaosensis (Apidae: Meliponini)

Melipona interrupta manaosensis is an important pollinator in the Neotropics. This stingless bee is reared by locals for honey production and also for conservation purposes. Eleven microsatellite markers were isolated from M. i. manaosensis and characterized in 32 individuals from the Meliponary of the Instituto Nacional de Pesquisas da Amazônia, Manaus, AM, Brazil. The number of alleles observed for each locus ranged from 2 to 5 (average 2.77). The polymorphism information content (PIC) varied between 0.08 to 0.62 (average 0.34) and the discriminating power (D) ranged from 0.61 to 0.99 (average 0.85). The observed heterozygosity (H O) and the expected heterozygosity (H E) ranged from 0.04 to 1.00 and 0.04 to 0.67, respectively. These microsatellites will be useful for future genetic studies of M. i. manaosensis populations and correlated species contributing with Amazon biodiversity preservation. © Springer Science+Business Media B.V. 2009