Dynamic formation of microvillus inclusions during enterocyte differentiation in Munc18-2–deficient intestinal organoids

  • Background & Aims: Microvillus inclusion disease (MVID) is a congenital intestinal malabsorption disorder caused by defective apical vesicular transport. Existing cellular models do not fully recapitulate this heterogeneous pathology. The aim of this study was to characterize 3-dimensional intestinal organoids that continuously generate polarized absorptive cells as an accessible and relevant model to investigate MVID. Methods: Intestinal organoids from Munc18-2/Stxbp2-null mice that are deficient for apical vesicular transport were subjected to enterocyte-specific differentiation protocols. Lentiviral rescue experiments were performed using human MUNC18-2 variants. Apical trafficking and microvillus formation were characterized by confocal and transmission electron microscopy. Spinning disc time-lapse microscopy was used to document the lifecycle of microvillus inclusions. Results: Loss of Munc18-2/Stxbp2 recapitulated the pathologic features observed in patients with MUNC18-2 deficiency. The defects were fully restored by transgenic wild-type human MUNC18-2 protein, but not the patient variant (P477L). Importantly, we discovered that the MVID phenotype was correlated with the degree of enterocyte differentiation: secretory vesicles accumulated already in crypt progenitors, while differentiated enterocytes showed an apical tubulovesicular network and enlarged lysosomes. Upon prolonged enterocyte differentiation, cytoplasmic F-actin–positive foci were observed that further progressed into classic microvillus inclusions. Time-lapse microscopy showed their dynamic formation by intracellular maturation or invagination of the apical or basolateral plasma membrane. Conclusions: We show that prolonged enterocyte-specific differentiation is required to recapitulate the entire spectrum of MVID. Primary organoids can provide a powerful model for this heterogeneous pathology. Formation of microvillus inclusions from multiple membrane sources showed an unexpected dynamic of the enterocyte brush border.
Author:Mohammed Hossameldin Mosa, Ophélie Nicolle, Sophia Maschalidi, Fernando E. Sepulveda, Aurelien Bidaud-Meynard, Constantin Menche, Birgitta Elisabeth Michels, Grégoire Michaux, Geneviève de Saint Basile, Henner FarinORCiDGND
Pubmed Id:https://pubmed.ncbi.nlm.nih.gov/30364784
Parent Title (English):Cellular and Molecular Gastroenterology and Hepatology
Place of publication:New York, NY
Document Type:Article
Year of Completion:2018
Date of first Publication:2018/08/14
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2018/11/08
Tag:Apical Vesicular Transport; Brush Border Formation; Disease Modeling; Microvillus Atrophy
Page Number:18
First Page:477
Last Page:493.e1
© 2018 The Authors. Published by Elsevier Inc. on behalf of the AGA Institute. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Institutes:Biowissenschaften / Biowissenschaften
Angeschlossene und kooperierende Institutionen / Georg-Speyer-Haus
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Licence (German):License LogoCreative Commons - Namensnennung-Nicht kommerziell - Keine Bearbeitung 4.0