Yazar "Mes, Jurriaan J." seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Coffee induces AHR- and Nrf2-mediated transcription in intestinal epithelial cells
    (Elsevier Sci Ltd, 2021) Toydemir, Gamze; Loonen, Linda M. P.; Venkatasubramanian, Prashanna Balaji; Mes, Jurriaan J.; Wells, Jerry M.; De Wit, Nicole
    Coffee induces a health-promoting adaptive response of cells in the body. Here, we investigated enterocyte responses to AHR agonists in coffee and measured their transport across a polarized intestinal epithelium. AHR-activating potencies of Turkish, filter, and instant coffee were determined using DR CALUX (R) bioassay, before and after intestinal metabolization by Caco-2 cells. Furthermore, effects of coffee on induction of AHRand Nrf2-pathway genes in Caco-2 cells were evaluated by real-time qPCR. Coffee samples showed considerable AHRactivating potencies in DR CALUX (R) bioassay (up to 79% of positive control activity). After incubation with Caco2 cells, AHR activity of different coffees was between 35 and 64% of their initial value, suggesting rapid uptake and metabolization by epithelial cells. Expression of AHR-regulated gene CYP1A1 increased up to 41-fold and most Nrf2-pathway genes were up-regulated by coffee. This in vitro study may support the notion that coffee bioactives contribute to antioxidant defense and detoxification processes in vivo.
  • [ X ]
    Öğe
    Use of microarray datasets to generate Caco-2-dedicated networks and to identify reporter genes of specific pathway activity
    (Nature Publishing Group, 2017) Venkatasubramanian, Prashanna Balaji; Toydemir, Gamze; de Wit, Nicole; Saccenti, Edoardo; dos Santos, Vitor A. P. Martins; van Baarlen, Peter; Mes, Jurriaan J.
    Intestinal epithelial cells, like Caco-2, are commonly used to study the interaction between food, other luminal factors and the host, often supported by microarray analysis to study the changes in gene expression as a result of the exposure. However, no compiled dataset for Caco-2 has ever been initiated and Caco-2-dedicated gene expression networks are barely available. Here, 341 Caco-2-specific microarray samples were collected from public databases and from in-house experiments pertaining to Caco-2 cells exposed to pathogens, probiotics and several food compounds. Using these datasets, a gene functional association network specific for Caco-2 was generated containing 8937 nodes 129711 edges. Two in silico methods, a modified version of biclustering and the new Differential Expression Correlation Analysis, were developed to identify Caco-2-specific gene targets within a pathway of interest. These methods were subsequently applied to the AhR and Nrf2 signalling pathways and altered expression of the predicted target genes was validated by qPCR in Caco-2 cells exposed to coffee extracts, known to activate both AhR and Nrf2 pathways. The datasets and in silico method(s) to identify and predict responsive target genes can be used to more efficiently design experiments to study Caco-2/intestinal epithelial-relevant biological processes.