Enteroids\nto Study Pediatric Intestinal Drug Transport

Intestinal maturational changes after birth affect the\npharmacokinetics\n(PK) of drugs, having major implications for drug safety and efficacy.\nHowever, little is known about ontogeny-related PK patterns in the\nintestine. To explore the accuracy of human enteroid monolayers for\nstudying drug transport in the pediatric intestine, we compared the\ndrug transporter functionality and expression in enteroid monolayers\nand tissue from pediatrics and adults. Enteroid monolayers were cultured\nof 14 pediatric [median (range) age: 44 weeks (2 days–13 years)]\nand 5 adult donors, in which bidirectional drug transport experiments\nwere performed. In parallel, we performed similar experiments with\ntissue explants in Ussing chamber using 11 pediatric [median (range)\nage: 54 weeks (15 weeks–10 years)] and 6 adult tissues. Enalaprilat,\npropranolol, talinolol, and rosuvastatin were used to test paracellular,\ntranscellular, and transporter-mediated efflux by P-gp and breast\ncancer resistance protein (BCRP), respectively. In addition, we compared\nthe expression patterns of ADME-related genes in pediatric and adult\nenteroid monolayers with tissues using RNA sequencing. Efflux transport\nby P-gp and BCRP was comparable between the enteroids and tissue.\nEfflux ratios (ERs) of talinolol and rosuvastatin by P-gp and BCRP,\nrespectively, were higher in enteroid monolayers compared to Ussing\nchamber, likely caused by experimental differences in model setup\nand cellular layers present. Explorative statistics on the correlation\nwith age showed trends of increasing ER with age for P-gp in enteroid\nmonolayers; however, it was not significant. In the Ussing chamber\nsetup, lower enalaprilat and propranolol transport was observed with\nage. Importantly, the RNA sequencing pathway analysis revealed that\nage-related variation in drug metabolism between neonates and adults\nwas present in both enteroids and intestinal tissue. Age-related differences\nbetween 0 and 6 months old and adults were observed in tissue as well\nas in enteroid monolayers, although to a lesser extent. This study\nprovides the first data for the further development of pediatric enteroids\nas an in vitro model to study age-related variation in drug transport.\nOverall, drug transport in enteroids was in line with data obtained\nfrom ex vivo tissue (using chamber) experiments. Additionally, pathway\nanalysis showed similar PK-related differences between neonates and\nadults in both tissue and enteroid monolayers. Given the challenge\nto elucidate the effect of developmental changes in the pediatric\nage range in human tissue, intestinal enteroids derived from pediatric\npatients could provide a versatile experimental platform to study\npediatric phenotypes.