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

Circulating microRNA levels predict residual beta cell function and glycaemic control in children with type 1 diabetes mellitus

Aims/hypothesis: We aimed to identify circulating microRNA (miRNA) that predicts clinical progression in a cohort of 123 children with new-onset type 1 diabetes mellitus. Methods: Plasma samples were prospectively obtained at 1, 3, 6, 12 and 60 months after diagnosis from a subset of 40 children from the Danish Remission Phase Cohort, and profiled for miRNAs. At the same time points, meal-stimulated C-peptide and HbA 1c levels were measured and insulin-dose adjusted HbA 1c (IDAA 1c) calculated. miRNAs that at 3 months after diagnosis predicted residual beta cell function and glycaemic control in this subgroup were further validated in the remaining cohort (n = 83). Statistical analysis of miRNA prediction for disease progression was performed by multiple linear regression analysis adjusted for age and sex. Results: In the discovery analysis, six miRNAs (hsa-miR-24-3p, hsa-miR-146a-5p, hsa-miR-194-5p, hsa-miR-197-3p, hsa-miR-301a-3p and hsa-miR-375) at 3 months correlated with residual beta cell function 6–12 months after diagnosis. Stimulated C-peptide at 12 months was predicted by hsa-miR-197-3p at 3 months (p = 0.034). A doubling of this miRNA level corresponded to a sixfold higher stimulated C-peptide level. In addition, a doubling of hsa-miR-24-3p and hsa-miR-146a-5p levels at 3 months corresponded to a 4.2% (p &lt; 0.014) and 3.5% (p &lt; 0.022) lower IDAA 1c value at 12 months. Analysis of the remaining cohort confirmed the initial finding for hsa-miR-197-3p (p = 0.018). The target genes for the six miRNAs revealed significant enrichment for pathways related to gonadotropin-releasing hormone receptor and angiogenesis pathways. Conclusions/interpretation: The miRNA hsa-miR-197-3p at 3 months was the strongest predictor of residual beta cell function 1 year after diagnosis in children with type 1 diabetes mellitus. </p

The evolutionary history of the allopolyploid Squalius alburnoides (Cyprinidae) complex in the northern Iberian Peninsula

Understanding the population structure, population dynamics and processes that give rise to polyploidy and helps to maintain it is central to our knowledge of the evolution of asexual vertebrates. Previous studies revealed high genetic diversity and several reproductive pathways in the southern populations of the Squalius alburnoides hybrid complex. In contrast, lower genetic variability and the associated limited chance of introducing new genetic combinations may threaten the survival of the northern Mondego populations. We analysed the genetic diversity and structure of nine populations of S. alburnoides in the Iberian Peninsula using microsatellite loci to provide further insights on the evolutionary history of this complex. Special attention was given to the less-studied northern populations (Mondego and Douro basins). Marked population structure, a high frequency of private alleles and a high diversity of some biotypes in the Douro basin indicate that some northern populations may not be at high risk of extinction, contrary to what was expected. The genetic diversity found in the northern Douro populations contradicts the general trend of remarkable genetic impoverishment northwards that occurs in other species and regions. The results indicate the possible existence of a glacial refugium in the Rabaçal River, corroborating findings in other species of this region. Historical events seem to have affected the geographical patterns of genetic variability found among and within the northern and southern populations of this complex and contributed to different patterns of genome composition. Therefore, historical events might have a major role in the long-term persistence of some polyploid hybrid taxa