| Author |
Janecke, Andreas Clevers, Hans Müller, Thomas Huber, Lukas A. Teunissen, Hans El Bouazzaoui, Layla Begthel, Harry Beekman, Jeffrey M. Middendorp, Sabine Vogel, Georg F. Van Ommen, Domenique D. Gerner, Patrick Schneeberger, Kerstin Nieuwenhuis, Edward E. S. Van Es, Johan H. Van Vugt, Anke H. M. Klumperman, Judith Hess, Michael W. |
| Description |
Author Affiliation: Schneeberger K ( Division of Paediatrics, Department of Paediatric Gastroenterology, Wilhelmina Children's Hospital, University Medical Centre (UMC) Utrecht, 3584 EA, Utrecht, The Netherlands); Vogel GF ( Division of Cell Biology, Biocenter, Medical University Innsbruck, A-6020 Innsbruck, Austria); Teunissen H ( Division of Paediatrics, Department of Paediatric Gastroenterology, Wilhelmina Children's Hospital, University Medical Centre (UMC) Utrecht, 3584 EA, Utrecht, The Netherlands); van Ommen DD ( Laboratory of Translational Immunology and Department of Paediatric Pulmonology, Wilhelmina Children's Hospital, UMC Utrecht, 3584 EA, Utrecht, The Netherlands); Begthel H ( Hubrecht Institute for Developmental Biology and Stem Cell Research, Royal Dutch Academy of Sciences and UMC Utrecht, 3584 CT, Utrecht, The Netherlands); El Bouazzaoui L ( Division of Paediatrics, Department of Paediatric Gastroenterology, Wilhelmina Children's Hospital, University Medical Centre (UMC) Utrecht, 3584 EA, Utrecht, The Netherlands); van Vugt AH ( Division of Paediatrics, Department of Paediatric Gastroenterology, Wilhelmina Children's Hospital, University Medical Centre (UMC) Utrecht, 3584 EA, Utrecht, The Netherlands); Beekman JM ( Laboratory of Translational Immunology and Department of Paediatric Pulmonology, Wilhelmina Children's Hospital, UMC Utrecht, 3584 EA, Utrecht, The Netherlands); Klumperman J ( Department of Cell Biology and The Cell Microscopy Centre, UMC Utrecht, 3584 CX, Utrecht, The Netherlands); Müller T ( Department of Pediatrics I, Medical University Innsbruck, A-6020 Innsbruck, Austria); Janecke A ( Department of Pediatrics I, Medical University Innsbruck, A-6020 Innsbruck, Austria); Gerner P ( Zentrum für Kinder- und Jugendmedizin, Universitätsklinikum Freiburg, 79106 Freiburg, Germany.); Huber LA ( Division of Cell Biology, Biocenter, Medical University Innsbruck, A-6020 Innsbruck, Austria); Hess MW ( Division of Histology and Embryology, Medical University Innsbruck, A-6020 Innsbruck Austria); Clevers H ( Hubrecht Institute for Developmental Biology and Stem Cell Research, Royal Dutch Academy of Sciences and UMC Utrecht, 3584 CT, Utrecht, The Netherlands); van Es JH ( Hubrecht Institute for Developmental Biology and Stem Cell Research, Royal Dutch Academy of Sciences and UMC Utrecht, 3584 CT, Utrecht, The Netherlands); Nieuwenhuis EE ( Division of Paediatrics, Department of Paediatric Gastroenterology, Wilhelmina Children's Hospital, University Medical Centre (UMC) Utrecht, 3584 EA, Utrecht, The Netherlands); Middendorp S ( Division of Paediatrics, Department of Paediatric Gastroenterology, Wilhelmina Children's Hospital, University Medical Centre (UMC) Utrecht, 3584 EA, Utrecht, The Netherlands); |
| Abstract |
Microvillus inclusion disease (MVID) is a rare intestinal enteropathy with an onset within a few days to months after birth, resulting in persistent watery diarrhea. Mutations in the myosin Vb gene (MYO5B) have been identified in the majority of MVID patients. However, the exact pathophysiology of MVID still remains unclear. To address the specific role of MYO5B in the intestine, we generated an intestine-specific conditional Myo5b-deficient (Myo5bfl/fl;Vil-CreERT2) mouse model. We analyzed intestinal tissues and cultured organoids of Myo5bfl/fl;Vil-CreERT2 mice by electron microscopy, immunofluorescence, and immunohistochemistry. Our data showed that Myo5bfl/fl;Vil-CreERT2 mice developed severe diarrhea within 4 d after tamoxifen induction. Periodic Acid Schiff and alkaline phosphatase staining revealed subapical accumulation of intracellular vesicles in villus enterocytes. Analysis by electron microscopy confirmed an almost complete absence of apical microvilli, the appearance of microvillus inclusions, and enlarged intercellular spaces in induced Myo5bfl/fl;Vil-CreERT2 intestines. In addition, we determined that MYO5B is involved not only in apical but also basolateral trafficking of proteins. The analysis of the intestine during the early onset of the disease revealed that subapical accumulation of secretory granules precedes occurrence of microvillus inclusions, indicating involvement of MYO5B in early differentiation of epithelial cells. By comparing our data with a novel MVID patient, we conclude that our mouse model completely recapitulates the intestinal phenotype of human MVID. This includes severe diarrhea, loss of microvilli, occurrence of microvillus inclusions, and subapical secretory granules. Thus, loss of MYO5B disturbs both apical and basolateral trafficking of proteins and causes MVID in mice. |
