Fetal gut laser microdissection in combination with RNA preamplification enables epithelial-specific transcriptional profiling

Polyvinylsulfonic acid: A Low-cost RNase inhibitor for enhanced RNA preservation and cell-free protein translation

The effectiveness and economics of polyvinyl sulfonic acid (PVSA) as a ribonuclease inhibitor for in vitro systems is reported. PVSA was shown to inhibit RNA cleavage in the presence of RNase A as well as in the presence of Escherichia coli lysate, suggesting that PVSA can act as a broader ribonuclease inhibitor. In addition, PVSA was shown to improve the integrity of mRNA transcripts by up to 5-fold in vitro as measured by their translational viability. Improved preservation of mRNA transcripts in the presence of PVSA under common RNA storage conditions is also reported. A cost comparison with commercially available RNAse inhibitors indicates the economic practicality of PVSA which is approximately 1,700 times less expensive than commonly used ribonuclease inhibitors. PVSA can also be separated from RNA by alcohol precipitation for applications that may be sensitive to the presence of PVSA.

Analysis of steroidogenic pathway key transcripts in interrenal cells isolated by laser microdissection (LMD) in stressed rainbow trout

An assessment of the key transcripts expression of the steroidogenesis-related genes in rainbow trout subjected to either acute or chronic stress was performed in both interrenal cells and whole head kidney tissue. The analysis of interrenal cells was possible thanks to the use, for the first time in this specific type of cells, of the technique of laser microdissection (LMD) which allows to isolate specific cells and process them independently of other surrounding cells in the tissue. The results indicated that both acute and chronic stressors induced a significant up-regulation of the steroidogenesis-related genes with a higher but expected degree in the isolated cells. In addition, under acute stress a delay between cortisol levels and transcript expression was found. Under chronic stress a clear relation between plasma cortisol levels, mRNA transcription and interrenal tissue area was observed, since all parameters were concomitantly increased at day 5 after stress. Moreover results indicated that the LMD technique allowed ascertaining with more precision and accuracy whether and when the steroidogenesis-related genes were significantly expressed, disregarding the noise produced by other cells present in the head kidney. Results also showed a typical physiological response in plasma parameters and a positive relationship between plasma cortisol data and transcript abundance in isolated cells. The present results may help to better understand the mechanisms behind the interrenal response to stress challenges in fish.

Maternal High-fat Diet Accelerates Development of Crohn's Disease-like Ileitis in TNFΔARE/WT Offspring

BACKGROUND

Maternal high-fat diet (HFD) and obesity increases the risk of the offspring to develop inflammatory processes in various organs including the gut. We hypothesized that maternal diet-induced obesity programs the fetal gut towards inflammation in a mouse model of genetically-driven Crohn's disease (CD)-like ileitis.

METHODS

TNF(WT/WT) and TNF(ΔARE/WT) dams were fed an experimental control diet (CTRLD; 13 kJ% fat) or HFD (48 kJ%). Offspring mice were fed CTRLD or HFD at 4 weeks of age. Metabolic characteristics and severity of CD-like ileitis was assessed in 8- and 12-week old WT and ARE offspring measuring tissue histopathology and markers of inflammation in the distal ileum as well as plasma cytokine and LPS levels. To study prenatal effects, we laser microdissected fetal intestinal epithelial cells at 17.5 days postconception and performed microarray-based global gene expression analysis.

RESULTS

Maternal HFD significantly accelerated the severity of CD-like ileitis in HFD-fed ARE mice at early life stages associated with increased mucosal neutrophil infiltration, Il12p40 expression, and portal vein LPS levels. In contrast to WT mice, metabolic characteristics of ARE offspring were not affected by maternal HFD. Gene expression patterns in fetal intestinal epithelial cells of ARE mice remained largely unchanged under conditions of maternal diet-induced obesity suggesting that the positive association of intestinal inflammation, portal vein endotoxemia, and plasma TNF levels is independent of prenatal conditioning of the gut epithelium.

CONCLUSIONS

Maternal HFD promotes the early onset of severe CD-like ileitis in genetically susceptible offspring independent of metabolic alterations.