Regulation of nutrient and electrolyte absorption in human organoid-derived intestinal epithelial cell monolayers

Recently developed human intestinal epithelial 3D organoid cultures are a useful cell culture model to study intestinal transport physiology. From these, 2D mono -layer cultures can be generated in which apical transporters are exposed to the medium, thereby better facilitating in vitro investigation of intestinal absorption pro-cesses. However, whether nutrient and electrolyte absorption can be physiologi-cally regulated in human organoid-derived monolayers has not been determined. Constitutive nitric oxide (cNO) is known to regulate multiple gastrointestinal physio-logical functions. Previous studies using in vivo and in vitro mammalian animal mod-els indicate that enhanced intracellular cNO differentially regulates the two primary apical Na transporters in small intestinal epithelial cells. Here, we generated human jejunal organoid-derived monolayers to determine whether apical nutrient and electrolyte transporter function is regulated by cNO in human enterocytes. Western blot analysis and immunocytochemical staining showed that organoid-derived 2D cultures express markers of enterocyte differentiation and form intact monolayers of apical-basal polarized epithelial cells. Uptake studies demonstrated that jejunal monolayers exhibit functional activity of Na-glucose cotransporter 1 (SGLT1; SLC5A1) and Na-H exchanger 3 (NHE3; SLC9A3). In response to physiological increases in cNO, the two primary apical Na transporters were differentially regu-lated in human intestinal organoid-derived monolayers, across multiple human specimens. An increase in cNO stimulated SGLT1, while NHE3 was inhibited. These results are similar to what is seen in vivo and in vitro in different animal intestinal models. Thus, human jejunal organoid-derived monolayers are an ideal in vitro model to better understand how intestinal nutrient absorption is regulated. (Transla-tional Research 2022; 248:22-35)

Automated summary

Recent studies have shown that human intestinal organoid-derived monolayer cultures can physiologically regulate the apical nutrient and electrolyte transporter function in intestinal cells, similar to observations in in vivo and in vitro animal models. Therefore, this culture model is of great importance for a better understanding of intestinal nutrient absorption regulation.