Loss of functional small bowel surface area following surgical resection for disorders including Crohn's disease, ischemia, trauma, or radiation enteritis may result in short bowel syndrome (SBS), an important cause of morbidity, mortality and health care costs in the U.S. SBS patients are frequently dependent on parenteral nutrition to meet their nutritional requirements. Following intestinal resection, the remaining small bowel epithelium mounts an adaptive response that increases villus height, crypt depth and enhances nutrient and electrolyte absorption. However, the adaptive response in humans is unpredictable and it may require up to two years to determine which patients will wean off parenteral nutrition, even with an accurate assessment of remnant small bowel length. The mechanistic basis for this clinical variability is unknown. Our application seeks to explore new regenerative, therapeutic approaches to enhance small bowel functional surface area, using patient biopsies from the PI's large SBS patient population. Our approach will translate observations from our preclinical models of short bowel syndrome and myofibroblast signaling in the stem cell niche into studies in human SBS that have therapeutic potential. We have shown that a myofibroblast protein, epimorphin (Epim) regulates crypt fission, gut epithelial proliferation and myofibroblast secretory function in mice. Co-culture with Epim-/- myofibroblasts further enhances WT mouse crypt enteroid growth and surface area. Our overarching goals are to enhance the proliferative epithelial response and increase small bowel surface area as a therapeutic strategy for SBS. Our overarching hypothesis is that modulating myofibroblast Epim and its targets will enhance human small bowel growth providing a novel regenerative therapeutic approach to SBS.
Aim 1 will directly translate our mouse studies by establishing stem cell/enteroid and myofibroblast cultures from the PI's large cohort of SBS patients. We will address the hypothesis that co- culture with Epim-deficient myofibroblasts increases the growth of human enteroids. We will determine whether growth and proliferative capacity of enteroids in vitro can predict the ability t adapt and wean from parenteral nutrition.
Aim 2 will address two hypotheses. 1. MF-crypt epithelial interactions are modulated by Epim deletion to increase crypt stem cell proliferation and enteroid growth via altered Bmp, Hh, and Wnt signaling pathways. 2. Epim demonstrates context-specific inhibitory vs. pro-exocytotic roles in regulating MF secretion. Our studies are significant because we will directly translate our findings from preclinical studies to human studies of Epim deletion's effects on MF function in the stem cell niche. We will expand our unique clinical collection of small bowel crypt stem/enteroid cultures from SBS patients, and generate a national resource for potential future high throughput screening of therapeutic agents that enhance stem and crypt cell proliferation in SBS. Epim and the secretion of soluble factors that are modulated by Epim deletion represent potential novel therapeutic targets to promote intestinal stem/crypt epithelial proliferation, leading to adaptation. .

Public Health Relevance

Short bowel syndrome (SBS) results from intestinal resection due to Crohn's disease, ischemic injury, radiation enteritis or trauma and is an important cause of morbidity, mortality and health care costs in the U.S. This application will study human short bowel syndrome by obtaining intestinal biopsies for stem cell cultures, to understand the contribution of the intestinal myofibroblast to the stem cell niche. An understanding of the stem cell niche is critical for the development of regenerative therapies for SBS, and our studies will generate a national resource for potential future high throughput screening of therapeutic agents that enhance stem and crypt cell proliferation in SBS.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK106382-04
Application #
9531342
Study Section
Clinical, Integrative and Molecular Gastroenterology Study Section (CIMG)
Program Officer
Greenwel, Patricia
Project Start
2015-09-01
Project End
2019-06-30
Budget Start
2018-07-01
Budget End
2019-06-30
Support Year
4
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Washington University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Rubin, Deborah C (2018) CFTR and the Regulation of Crypt Cell Proliferation. Cell Mol Gastroenterol Hepatol 5:418-419
Engelstad, Holly J; Barron, Lauren; Moen, Joseph et al. (2018) Remnant Small Bowel Length in Pediatric Short Bowel Syndrome and the Correlation with Intestinal Dysbiosis and Linear Growth. J Am Coll Surg 227:439-449
Dolai, Subhankar; Liang, Tao; Orabi, Abrahim I et al. (2018) Pancreatitis-Induced Depletion of Syntaxin 2 Promotes Autophagy and Increases Basolateral Exocytosis. Gastroenterology 154:1805-1821.e5
Vishy, Courtney E; Swietlicki, Elzbieta A; Gazit, Vered et al. (2018) Epimorphin regulates the intestinal stem cell niche via effects on the stromal microenvironment. Am J Physiol Gastrointest Liver Physiol 315:G185-G194
Lewis, Mark A; Sharabash, Noura; Miao, Zhi-Feng et al. (2017) Increased IFRD1 Expression in Human Colon Cancers Predicts Reduced Patient Survival. Dig Dis Sci 62:3460-3467
Zhu, Dan; Xie, Li; Kang, Youhou et al. (2017) Syntaxin 2 Acts as Inhibitory SNARE for Insulin Granule Exocytosis. Diabetes 66:948-959
Lu, Jianyun; Garcia, Amy M; Geisman, Taylor et al. (2016) Proline Absorption and SGK1 Expression are Inhibited in Intestinal Tis7 Transgenic Mice. Cell Physiol Biochem 38:1532-43
Rubin, Deborah C; Levin, Marc S (2016) Mechanisms of intestinal adaptation. Best Pract Res Clin Gastroenterol 30:237-48