Differentiation of Intestinal Epithelial Cells Mediated by Cell Confluence and/or Exogenous Nucleoside Supplementation

Abstract

Nucleotides (NT) and nucleosides (NS) play a key role in gastrointestinal development and in enterocyte healing after tissue damage. Exogenous NT and NS may therefore represent a novel therapy for maintaining gastrointestinal tract integrity. An exogenous NS mixture of thymidine, cytidine, guanosine and inosine (T-CGI) increases the proliferation rate of rat intestinal epithelial cell line 6 (IEC-6) cells, while a mixture of uridine, cytidine, guanosine and inosine (U-CGI) reduces IEC-6 proliferation independently of necrosis or apoptosis. This study aimed to analyze the effects of exogenous NS on IEC-6 differentiation under proliferation and differentiation conditions. To this end, IEC-6 cells were treated with NS T-CGI and NS U-CGI mixtures under low- and high-density conditions. Enterocyte differentiation was also assessed by flow cytometry, Western blotting, and light, fluorescence and transmission electron microscopy. Under proliferative conditions, villin expression was reduced in all cases, but NS-treated cells showed twofold the expression observed in NS-free cultures (controls) and more frequently showed characteristics of mature enterocytes. When cells were grown after confluence, villin expression, total protein production and morphology of NS-treated cultures were more differentiated compared with the control group. Our results demonstrate that T-CGI and U-CGI mixtures promote IEC-6 cell differentiation, with no significant differences between them. Unlike previous authors, we obtained this effect in cultures without an exogenous extracellular matrix such as Matrigel, reducing the variability among independent assays.

Schlafen 3 Mediates the Differentiating Effects of Cdx2 in Rat IEC-Cdx2L1 Enterocytes

“…However, villin is expressed when IEC-6 cells are grown beyond confluence [28] and butyric acid stimulates differentiation in those cells [17]. Our previous results also support a direct role for Slfn3 in IEC-6 differentiation in response to several exogenous stimuli [12].…”

Transcriptomic responses to functional feeds in Atlantic salmon (Salmo salar)

“…The immune parameters often found increased following feeding these diets include respiratory burst activity, plasma complement activity, serum lysozyme activity, and proliferative responses of lymphocytes to mitogens [39,60,74]. Often the immunostimulants can provide improved protection against a number of pathogenic bacteria including Aeromonas spp [75], Vibrio spp.…”

“…Both the de novo synthesis and salvage pathways are energy consuming and hence a ready supply of dietary nucleotides may be beneficial to rapidly proliferating tissue, such as the gastrointestinal tract [74]. Much of the nucleotide synthesis and salvage is performed in the liver and many cell types such as immune cells have a limited ability to synthesise nucleotides and rely on the supply of preformed molecules.…”

“…One direct effect is an increase in total gut area in both Atlantic salmon [97] and sea bream [98] following diets enriched with adenosine monophosphate (AMP). In mammals AMP alone can cause increased differentiation and growth in developing rat intestine [74]. Additionally, AMP may also increase the prevalence of the probiotic bacteria Bifidobacteria [99].…”

Growth factor TGF-β induces intestinal epithelial cell (IEC-6) differentiation: miR-146b as a regulatory component in the negative feedback loop

“…guanosine ? inosine) (Rodríguez-Serrano et al 2010), TNF-a, IFN-c (Kolinska et al 2008), gastrin (Wang et al 2003), and Matrigel (Carroll et al 1988) have been reported to effectively induce IEC-6 cell differentiation.…”