Physiological shear stress enhances differentiation and mucus-formation
of intestinal epithelial cells in vitro.
Abstract
The gastrointestinal (GI) mucus layer plays a pivotal role in tissue
homoeostasis and functionality of the gut. However, due to the shortage
of affordable, realistic in vitro mucus models, studies with deeper
insights into its structure and characteristics are rare. To obtain an
improved mucus model, we developed a reusable culture chamber
facilitating the application of physiologically relevant GI shear
stresses (0.002-0.08 dyn/cm2) to cells in a bioreactor
system. Differentiation of a confluent monolayer of human
mucus-producing epithelial HT29-MTX cells was monitored under dynamic
and static culture conditions. Cells under flow remained highly
proliferative and analysis via confocal microscopy revealed superior
reorganization into 3-dimensional villi-like structures compared to
static culture (up to 120 vs. 80 µm in height). Additionally, the median
mucus thickness was significantly increased under dynamic conditions
compared to static culture (41±14 vs. 29±14 µm) with a simultaneous
drastic reduction of culture time from three to two weeks for sufficient
maturation into goblet-like cells. We demonstrated the impact of culture
conditions on the differentiation of HT29-MTX cells, revealing
outstanding in vivo like reorganization of cells and the production of
thick adherent mucus networks when cultured under physiological shear
stress using our newly designed culture chamber.