Transcriptional analysis in peripheral blood cells of individuals with elevated phthalate exposure - Results of the EuroMix study.

Exposure to phthalates is widespread in Europe. Phthalates are considered endocrine disrupting compounds and are classified as toxic for reproduction. However how phthalates affect the transcriptome in humans remains largely unknown. To investigate the effects of phthalate exposure on the transcriptomic profile we conducted RNA sequencing on peripheral blood samples from the Norwegian EuroMix cohort. We compared gene expression changes between participants with high, medium, and low exposure of six phthalates and 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH). Comparing high and low exposure groups, DINCH was the compound that showed the highest number of differentially expressed genes (126 genes) followed by mono-n-butyl phthalate (MnBP; 89 genes) and mono-iso-nonyl phthalate (MiBP; 70 genes). Distributions between up- or down-regulated genes were similar across the different phthalates and DINCH. All phthalates including DINCH shared common differentially expressed genes ranging from 3 to 37 overlaps. Enriched Gene Ontology (GO) and biological pathway analysis revealed that most of the differentially expressed genes were associated with general cellular metabolism GO terms. MnBP and DINCH, particularly, showed a marked enrichment in various immunological function pathways including neutrophil degranulation, adaptive immune system and signaling by interleukins. Furthermore, the association between genes involved in the peroxisome proliferator activated receptor (PPAR) signaling pathway and phthalates, including DINCH, was evaluated. In total, 15 genes showed positive or negative associations across 5 phthalates and DINCH. MnBP and MiBP were the phthalate metabolites with the highest number of associations: 8 and 4 PPAR signaling pathway genes, respectively. Overall, we have performed an association study between phthalate exposure levels and modulation of transcriptomic profiles in human peripheral blood cells. DINCH, which is often mentioned as a substitute for phthalates, had comparable effects on differential gene expression in peripheral blood cells as phthalates.

Intermittent fasting induces chronic changes in the hepatic gene expression of Red Jungle Fowl (Gallus gallus).

BACKGROUND: Intermittent fasting (IF), the implementation of fasting periods of at least 12 consecutive hours on a daily to weekly basis, has received a lot of attention in recent years for imparting the life-prolonging and health-promoting effects of caloric restriction with no or only moderate actual restriction of caloric intake. IF is also widely practiced in the rearing of broiler breeders, the parent stock of meat-type chickens, who require strict feed restriction regimens to prevent the serious health problems associated with their intense appetites. Although intermittent fasting has been extensively used in this context to reduce feed competition and its resulting stress, the potential of IF in chickens as an alternative and complementary model to rodents has received less investigation. In both mammals and birds, the liver is a key component of the metabolic response to IF, responding to variations in energy balance. Here we use a microarray analysis to examine the liver transcriptomics of wild-type Red Jungle Fowl chickens fed either ad libitum, chronically restricted to around 70% of ad libitum daily or intermittently fasted (IF) on a 2:1 (2 days fed, 1 day fasted) schedule without actual caloric restriction. As red junglefowl are ancestral to domestic chicken breeds, these data serve as a baseline to which existing and future transcriptomic results from farmed birds such as broiler breeders can be compared. RESULTS: We find large effects of feeding regimen on liver transcriptomics, with most of the affected genes relating to energy metabolism. A cluster analysis shows that IF is associated with large and reciprocal changes in genes related to lipid and carbohydrate metabolism, but also chronic changes in genes related to amino acid metabolism (generally down-regulated) and cell cycle progression (generally up-regulated). The overall transcription pattern appears to be one of promoting high proliferative plasticity in response to fluctuations in available energy substrates. A small number of inflammation-related genes also show chronically changed expression profiles, as does one circadian rhythm gene. CONCLUSIONS: The increase in proliferative potential suggested by the gene expression changes reported here indicates that birds and mammals respond similarly to intermittent fasting practices. Our findings therefore suggest that the health benefits of periodic caloric restriction are ubiquitous and not restricted to mammals alone. Whether a common fundamental mechanism, for example involving leptin, underpins these benefits remains to be elucidated.

Investigating the in vitro steatotic mixture effects of similarly and dissimilarly acting test compounds using an adverse outcome pathway-based approach.

Within the EuroMix project, we have previously developed an adverse outcome pathway (AOP)-based in vitro assay toolbox to investigate the combined effects of liver steatosis-inducing compounds in human HepaRG hepatocarcinoma cells. In this study, we applied the toolbox to further investigate mixture effects of combinations, featuring either similarly acting or dissimilarly acting substances. The valproic acid structural analogs 2-propylheptanoic acid (PHP) and 2-propylhexanoic acid (PHX) were chosen for establishing mixtures of similarly acting substances, while a combination with the pesticidal active substance clothianidin (CTD) was chosen for establishing mixtures of dissimilarly acting compounds. We first determined relative potency factors (RPFs) for each compound based on triglyceride accumulation results. Thereafter, equipotent mixtures were tested for nuclear receptor activation in transfected HepG2 cells, while gene expression and triglyceride accumulation were investigated in HepaRG cells, following the proposed AOP for liver steatosis. Dose addition was observed for all combinations and endpoints tested, indicating the validity of the additivity assumption also in the case of the tested mixtures of dissimilarly acting substances. Gene expression results indicate that the existing steatosis AOP can still be refined with respect to the early key event (KE) of gene expression, in order to reflect the diversity of molecular mechanisms underlying the adverse outcome.

Maternal exposure to mixtures of dienestrol, linuron and flutamide. Part II: Endocrine-related gene expression assessment on male offspring rat testes.

Exposure to endocrine-disrupting compounds (EDCs) during pregnancy and early development can lead to adverse developmental outcomes in offspring. One of the endpoints of concern is feminization. The present study aimed to investigate for any possible correlations with endocrine sensitive parameters in the testes of male rat offspring following dam exposure to three EDCs by assessing the expression of endocrine-related genes. Dienestrol (DIES) [0.37-6.25 µg/kg bw/day], linuron (LIN) [1.5-50 mg/kg bw/day], flutamide (FLU) [3.5-50 mg/kg bw/day] as well as their binary mixtures were administered to sexually mature female rats from gestation day (GD) 6 until postnatal day (PND) 21. Gene expression analysis of Star, Cyp11a1, Cyp17a1, Hsd3b2, Pgr and Insl3 was performed by RT-qPCR. Administration of the anti-androgen FLU alone significantly upregulated Cyp11a1 and Cyp17a1 gene expression while administration of LIN and DIES alone did not alter significantly gene expression. The effects of the binary mixtures on gene expression were not as marked as those seen after single compound administrations. Deregulation of Cyp17a1 in rat pup testis, following administration of FLU alone or in mixtures to dams, was significantly correlated with the observed feminization endpoints in male pups.

Genomic Regions Associated With Interspecies Communication in Dogs Contain Genes Related to Human Social Disorders.

Unlike their wolf ancestors, dogs have unique social skills for communicating and cooperating with humans. Previously, significant heritabilities for human-directed social behaviors have been found in laboratory beagles. Here, a Genome-Wide Association Study identified two genomic regions associated with dog's human-directed social behaviors. We recorded the propensity of laboratory beagles, bred, kept and handled under standardized conditions, to initiate physical interactions with a human during an unsolvable problem-task, and 190 individuals were genotyped with an HD Canine SNP-chip. One genetic marker on chromosome 26 within the SEZ6L gene was significantly associated with time spent close to, and in physical contact with, the human. Two suggestive markers on chromosome 26, located within the ARVCF gene, were also associated with human contact seeking. Strikingly, four additional genes present in the same linkage blocks affect social abilities in humans, e.g., SEZ6L has been associated with autism and COMT affects aggression in adolescents with ADHD. This is, to our knowledge, the first genome-wide study presenting candidate genomic regions for dog sociability and inter-species communication. These results advance our understanding of dog domestication and raise the use of the dog as a novel model system for human social disorders.

Cell adhesion molecules and their relation to (cancer) cell stemness.

Despite decades of search for anticancer drugs targeting solid tumors, this group of diseases remains largely incurable, especially if in advanced, metastatic stage. In this review, we draw comparison between reprogramming and carcinogenesis, as well as between stem cells (SCs) and cancer stem cells (CSCs), focusing on changing garniture of adhesion molecules. Furthermore, we elaborate on the role of adhesion molecules in the regulation of (cancer) SCs division (symmetric or asymmetric), and in evolving interactions between CSCs and extracellular matrix. Among other aspects, we analyze the role and changes of expression of key adhesion molecules as cancer progresses and metastases develop. Here, the role of cadherins, integrins, as well as selected transcription factors like Twist and Snail is highlighted, not only in the regulation of epithelial-to-mesenchymal transition but also in the avoidance of anoikis. Finally, we briefly discuss recent developments and new strategies targeting CSCs, which focus on adhesion molecules or targeting tumor vasculature.