Length-control of Microvilli in Intestinal Epithelial cells

Actin structures called microvilli project from the apical surface of epithelial cells that line the intestines. Mature microvilli have precisely regulated lengths, and defects in microvillar lengths are associated with celiac disease. Studies using epithelial cells in vitro have determined that actin-binding proteins (EPS8 and NMIIC) are important for maintaining microvillar length, but how these proteins work together to maintain microvillar length are largely unknown. Here we study a theoretical model that describes molecular mechanisms mediated by proteins EPS8 and NMIIC, which can provide length-dependent feedback cues and control microvillar length. We study this process theoretically using stochastic simulations, and statistically analyze the simulated length trajectories. We describe the resulting probability distribution of lengths and the length fluctuations as a function of model parameters like the concentrations of EPS8 and NMIIC. Our study describes how actin binding proteins can work together to maintain sizes of these actin structures.