Growth behavior and mRNA expression profiling during growth of IPEC-J2 cells.

OBJECTIVE: The IPEC-J2 cell line is used as an in vitro small intestine model for swine, but it is also used as a model for the human intestine, presenting a relatively unique setting. By combining electric cell-substrate impedance sensing, with next-generation-sequencing technology, we showed that mRNA gene expression profiles and related pathways can depend on the growth phase of IPEC-J2 cells. Our investigative approach welcomes scientists to reproduce or modify our protocols and endorses putting their gene expression data in the context of the respective growth phase of the cells. RESULTS: Three time points are presented: (TP1) 1 h after medium change (= 6 h after seeding of cells), (TP2) the time point of the first derivative maximum of the cell growth curve, and a third point at the beginning of the plateau phase (TP3). Significantly outstanding at TP1 compared to TP2 was upregulated PLEKHN1, further FOSB and DEGS2 were significantly downregulated at TP2 compared to TP3. Any provided data can be used to improve next-generation experiments with IPEC-J2 cells.

Does environmental stress affect cortisol biodistribution in freshwater mussels?

As of today, regulation and physiological purpose of steroid hormones in invertebrates such as mussels are not completely understood. Many studies were able to show their presence, but their origin and genesis are not clear. Nevertheless, knowledge about changes in steroid hormone biodistribution in reaction to treatments could improve our understanding of their physiological functions in these species. Cortisol is a corticosteroid, which is frequently used as a stress biomarker in vertebrates, like fish or higher organisms. The aim of the study was to optimize cortisol extraction from various tissues of mussels, to develop a quantitative ELISA test system, and to study changes in biodistribution of cortisol in reaction to negative and positive stimulation treatments. As model organism, we used Anodonta anatina, a widespread freshwater mussel species native to Europe. We quantified cortisol concentrations in hepatopancreas, mantle, gills, gonads and the foot muscle. Tissue-specific reactions to environmental influences, simulated with the chemical stressors copper (II) chloride and sodium chloride, were assessed. During the 24-hours treatment, we additionally observed changes in cortisol regulation in response to feeding activity of the mussels. Besides, we found highly significant variations in the biodistribution of cortisol in different tissues, with a peak in the hepatopancreas. Whole body cortisol did not increase in the treated groups. However, balancing of all measured tissues showed redistribution of more than 10% of total body cortisol from the hepatopancreas to all other tissues during copper (II) chloride stressor treatment, but also when mussels ingested feed, compared to the non-fed control group. No redistribution was observed during sodium chloride treatment. We conclude that there can be a redistribution of cortisol in mussels, depending on external influences.