Journal article

Authors list: Pauer, Svenja Mareike; Buß, Brigitta; Diener, Martin; Ballout, Jasmin

Publication year: 2024

Journal: Frontiers in Physiology

Volume number: 15

eISSN: 1664-042X

Open access status: Gold

DOI Link: https://doi.org/10.3389/fphys.2024.1382238

Publisher: Frontiers Media

Abstract: 
Background: Intestinal organoids are stem cell-derived, 3D "mini-guts" with similar functions as the native intestinal epithelium such as electrolyte transport or establishment of an epithelial barrier. During intestinal inflammation, epithelial functions are dysregulated by proinflammatory cytokines like tumor necrosis factor alpha (TNF alpha) and other messengers from the immune system resulting in a loss of electrolytes and water due to an impaired epithelial barrier and higher net secretion. Methods: A murine small intestinal organoid model was established to study (long-term) effects of TNF alpha on the intestinal epithelium in vitro using live imaging, immunohistochemical staining and qPCR. Results: TNF alpha induced apoptosis in intestinal organoids as indicated by an increased number of cells with immunoreactivity for cleaved caspase 3. Furthermore, TNF alpha exposure led to swelling of the organoids which was inhibited by bumetanide and was concomitant with an upregulation of the bumetanide-sensitive Na+-K+-2Cl(-) symporter 1 (NKCC1) as shown by qPCR. Fura-2 imaging experiments revealed time-dependent changes in Ca2+ signaling consisting of a rise in the basal cytosolic Ca2+ concentration at day 1 and an increase of the carbachol-induced Ca2+ response after 3 days TNF alpha exposure. This was prevented by preincubation with La3+, an inhibitor of non-selective cation channels, or by using a Ca2+-free buffer indicating an enhancement of the Ca2+ influx from the extracellular side by the cytokine. No significant changes in cDNA levels of epithelial barrier proteins could be observed in the presence of TNF alpha. Conclusion: Intestinal organoids are a useful tool to study the mechanism underlying the TNF alpha-induced secretion on enterocytes such as the regulation of NKCC1 expression or the modulation of cellular Ca2+ signaling.

Harvard Citation style: Pauer, S., Buß, B., Diener, M. and Ballout, J. (2024) Time-dependent effects of tumor necrosis factor α on Ca2+-dependent secretion in murine small intestinal organoids, Frontiers in Physiology, 15, Article 1382238. https://doi.org/10.3389/fphys.2024.1382238

APA Citation style: Pauer, S., Buß, B., Diener, M., & Ballout, J. (2024). Time-dependent effects of tumor necrosis factor α on Ca2+-dependent secretion in murine small intestinal organoids. Frontiers in Physiology. 15, Article 1382238. https://doi.org/10.3389/fphys.2024.1382238