Interleukin 1 beta and Prostaglandin E2 affect expression of DNA methylating and demethylating enzymes in human gingival fibroblasts
INTERNATIONAL IMMUNOPHARMACOLOGY
Authors: Seutter, Sara; Winfield, Jacquay; Esbitt, Alexis; Snyder, Samantha; Magner, Anastasia; Kim, Kristine; Carcuffe, Craig; Schmoyer, Jeremy; Kamrani, Payvand; Mercando, Jason; Shamseddin, Seyed M.; Green, Kevan; Borghaei, Ruth C.
Abstract
Periodontitis is a common chronic inflammatory condition that results in increased levels of inflammatory cytokines and inflammatory mediators. In addition to oral disease and tooth loss, it also causes low-grade systemic inflammation that contributes to development of systemic conditions including cardiovascular disease, pre-term birth, diabetes and cancer. Chronic inflammation is associated with epigenetic change, and it has been suggested that such changes can alter cell phenotypes in ways that contribute to both ongoing inflammation and development of associated pathologies. Here we show that exposure of human gingival fibroblasts to IL-1 beta increases expression of maintenance methyltransferase DNMT1 but decreases expression of de novo methyltransferase DNMT3a and the demethylating enzyme TET1, while exposure to PGE2 decreases expression of all three enzymes. IL-1 beta and PGE2 both affect global levels of DNA methylation and hydroxymethylation, as well as methylation of some specific CpG in inflammation-associated genes. The effects of IL-1 beta are independent of its ability to induce production of PGE2, and the effects of PGE2 on DNMT3a expression are mediated by the EP4 receptor. The finding that exposure of fibroblasts to IL-1 beta and PGE2 can result in altered expression of DNA methylating/demethylating enzymes and in changing patterns of DNA methylation suggests a mechanism through which inflammatory mediators might contribute to the increased risk of carcinogenesis associated with inflammation.
Preanalytical robustness of blood collection tubes with RNA stabilizers
CLINICAL CHEMISTRY AND LABORATORY MEDICINE
Authors: Stellino, Chiara; Hamot, Gael; Bellora, Camille; Trouet, Johanna; Betsou, Fay
Abstract
Background: Efficient blood stabilization is essential to obtaining reliable and comparable RNA analysis data in preclinical operations. PAXgene (Qiagen, Becton Dickinson) and Tempus (Applied Biosystems, Life Technologies) blood collection tubes with RNA stabilizers both avoid pre-analytical degradation of mRNA by endogenous nucleases and modifications in specific mRNA concentrations by unintentional up-or down-regulation of gene expression. Methods: Sixteen different preanalytical conditions were tested in PAXgene and Tempus blood samples from seven donors: different mixing after collection, different fill volumes and different 24-h transport temperature conditions after collection. RNA was extracted by column-based methods. The quality of the extracted RNA was assessed by spectrophotometric quantification, A260/A280 purity ratio, RNA Integrity Number (Agilent Bioanalyzer), miRNA quantative real time polymerase chain reaction (qRT-PCR) on two target miRNAs (RNU-24 and miR-16), mRNA quality index by qRT-PCR on the 3' and 5' region of the GAPDH gene, and the PBMC preanalytical score, based on the relative expression levels of the IL8 and EDEM3 coding genes. Results: When PAXgene RNA and Tempus blood collection tubes were used following the manufacturers' instructions, there was no statistically or technically significant difference in the output RNA quality attributes. However, the integrity of the RNA extracted from Tempus collection tubes was more sensitive to fill volumes and effective inversion, than to storage temperature, while the integrity of RNA extracted from PAXgene collection tubes was more sensitive to effective inversion and storage temperature than to fill volumes. Conclusions: Blood collection tubes with different RNA stabilizers present different robustness to common preanalytical variations.