The adult human intestine is over 20 feet long and has a functional absorptive surface area of nearly 2,000 square feet. Three major processes (which take place prior to birth) establish the effective absorptive surface required to sustain life: a) intestinal lengthening; b) generation of villi and c) apical surface polarization. The molecular processes underlying these attributes are important clinically and therapeutically, but are poorly understood. Work in the last project period established a model of intestinal growth, characterized by rapid proliferation, low apoptosis and directional dispersion of cells along the anterior/posterior (A/P) axis. Analysis of Wnt5a null intestines (a short bowel model) revealed defects in extension of radial filopodia during interkinetic nuclear migration, increased apoptosis, reduced pJNK activity, altered Golgi positioning and reduced Filamin A.
Aim 1 is driven by the hypothesis that a Wnt5a-Ror2-Filamin A pathway controls radial filopodial extension, insuring cell survival in the epithelium; this is important for proper lengthening. This pathway will be explored using genetic tools and intestinal explant cultures. At E14.5, subepithelial mesenchymal clusters form, causing overlying epithelial cells to change shape. Epithelial cells between clusters activate Cd44v6; rounded mitotic cells in these regions appear to drive a process of rapid invagination that determines the villus domains. The hypothesis driving Aim 2 is that Epithelial invagination defines the apical surfaces of the first villi; this process is driven by patterned mesenchymal clusters and aided by mechanical forces and specialized cell divisions. The role of intra-epithelial pressure and the need for mitotic progression and oriented cell division will be examined; the basis for impeded invagination in Ezrin-/- mice will be investigated. Finally, the cellular and molecular aspects of apical surface polarization and maturation will be studied in the early human endoderm using a new in vitro model system. The hypothesis underlying Aim 3 is: Human congenital short bowel caused by mutations in FLNA and CLMP result in improper apical polarization. The molecular sequence of polarization will be established in cultures of differentiating CDX2 cells and effects of short bowel mutations on that sequence will be determined. By focusing on the cell biology underlying the developmental biology of the early intestine, these studies are unveiling key processes that establish the template for generation of the apical absorptive surface. Mathematical modeling of the data is revealing which parameters are most critical over developmental time.

Public Health Relevance

An enormous intestinal surface area is essential for nutrient absorption. Events that generate this surface take place in fetal life but are understudied. Elucidation of the cellular molecular underpinnings involved could improve diagnosis and treatment of enteropathies and enhance in vitro engineering of intestine.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
2R01DK089933-06
Application #
9177514
Study Section
Clinical, Integrative and Molecular Gastroenterology Study Section (CIMG)
Program Officer
Greenwel, Patricia
Project Start
2010-08-15
Project End
2020-06-30
Budget Start
2016-08-01
Budget End
2017-06-30
Support Year
6
Fiscal Year
2016
Total Cost
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Wang, Sha; Cebrian, Cristina; Schnell, Santiago et al. (2018) Radial WNT5A-Guided Post-mitotic Filopodial Pathfinding Is Critical for Midgut Tube Elongation. Dev Cell 46:173-188.e3
Walton, Katherine D; Mishkind, Darcy; Riddle, Misty R et al. (2018) Blueprint for an intestinal villus: Species-specific assembly required. Wiley Interdiscip Rev Dev Biol 7:e317
Taniguchi, Kenichiro; Shao, Yue; Townshend, Ryan F et al. (2017) An apicosome initiates self-organizing morphogenesis of human pluripotent stem cells. J Cell Biol 216:3981-3990
Shao, Yue; Taniguchi, Kenichiro; Townshend, Ryan F et al. (2017) A pluripotent stem cell-based model for post-implantation human amniotic sac development. Nat Commun 8:208
Shao, Yue; Taniguchi, Kenichiro; Gurdziel, Katherine et al. (2017) Self-organized amniogenesis by human pluripotent stem cells in a biomimetic implantation-like niche. Nat Mater 16:419-425
Kumar, Namit; Srivillibhuthur, Manasa; Joshi, Shilpy et al. (2016) A YY1-dependent increase in aerobic metabolism is indispensable for intestinal organogenesis. Development 143:3711-3722
Walton, Katherine D; Freddo, Andrew M; Wang, Sha et al. (2016) Generation of intestinal surface: an absorbing tale. Development 143:2261-72
Walton, Katherine D; Whidden, Mark; Kolterud, ├ůsa et al. (2016) Villification in the mouse: Bmp signals control intestinal villus patterning. Development 143:427-36
Freddo, Andrew M; Shoffner, Suzanne K; Shao, Yue et al. (2016) Coordination of signaling and tissue mechanics during morphogenesis of murine intestinal villi: a role for mitotic cell rounding. Integr Biol (Camb) 8:918-28
Taniguchi, Kenichiro; Shao, Yue; Townshend, Ryan F et al. (2015) Lumen Formation Is an Intrinsic Property of Isolated Human Pluripotent Stem Cells. Stem Cell Reports 5:954-962

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