TY  - JOUR
A1  - Mosa, Mohammed Hossameldin
A1  - Nicolle, Ophélie
A1  - Maschalidi, Sophia
A1  - Sepulveda, Fernando E.
A1  - Bidaud-Meynard, Aurelien
A1  - Menche, Constantin
A1  - Michels, Birgitta E.
A1  - Michaux, Grégoire
A1  - Saint Basile, Geneviève de
A1  - Farin, Henner
T1  - Dynamic formation of microvillus inclusions during enterocyte differentiation in Munc18-2–deficient intestinal organoids
T2  - Cellular and Molecular Gastroenterology and Hepatology
N2  - 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.
KW  - Microvillus Atrophy
KW  - Disease Modeling
KW  - Brush Border Formation
KW  - Apical Vesicular Transport
Y1  - 2018
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/47932
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-479326
SN  - 2352-345X
N1  - © 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/).
VL  - 6
IS  - 4
SP  - 477
EP  - 493.e1
PB  - Elsevier
CY  - New York, NY
ER  -