Environmental factors such as microbiota or infection trigger immune-mediated tissue injury, which leads to chronic mucosal diseases in the genetically susceptible subjects, such as Inflammatory Bowel Diseases (IBD). Stem cell therapy has recently achieved many successful cases in the personalized treatment of IBD, but intestinal epithelial stem cell (IESC) treatment is still at an early stage. JAK-STAT activation wa suggested to promote adult intestinal stem cell division and differentiation, respectively, and thereby could drive the renewal of intestinal epithelial cells (IEC). We recently reported that STAT5 signaling prevents intestinal barrier dysfunction and promotes mucosal healing in colitic mouse models. Furthermore, our preliminary data indicated that deletion of STAT5 decreased the expression of stem cell markers Lgr5, Ascl2, and Olfm4, and inhibited NOTCH activation and cellular junction maturation in adult IESC-derived organoid. We therefore hypothesize that STAT5 signaling controls adult IESC activity via regulation of a stem cell gene signature to promote intercellular junction formation;activation of STAT5 signaling enhances IEC organoid engraftment against infection-induced intestinal barrier dysfunction. We will test our hypotheses with the following two Aims.
Our Aim 1 will determine the role of STAT5 signaling for adult IESC differentiation. The studies in this Aim will, first, inducibly delete IEC STAT5 or hyperactivate IEC STAT5 in mice to characterize IESC homeostasis, stem cell gene profiles, and Wnt/Notch signaling in adult mouse intestines. Second, using human pluripotent stem cells-derived intestinal organoids, we will genetically manipulate STAT5 expression to define STAT5's role in the regulation of Wnt/Notch signaling during IESC differentiation.
Our Aim 2 will define the requirement of STAT5 signaling for differentiation-associated development of IEC monolayers. First, we will characterize tight junction development using both STAT5 deficient and STAT5 inducible IESC-derived organoids. Second, we will culture these mouse organoids to implant the recipient control mice to assess IESC integrity and tight junction formation. Overall, we will determine that epithelial STAT5 regulates a stem cell gene signature via interplay with NOTCH signaling to promote intercellular junction reformation for healing mucosal inflammation. Our studies will demonstrate an essential role for STAT5 in the regulation of adult stem cell homeostasis via a stem cell gene signature, and will explore a novel engineered tissue therapy that directly heals the epithelial barrier disruption during mucosal inflammation. We propose a paradigm shift for this research field from understanding STAT5 signaling as an essential regulator of stem cell biology toward developing the potential therapeutic tool. We believe this exploratory R21 mechanism will permit a collaborative team of basic scientists and clinical investigators to start a brand-new project, and explore a novel potential therapeutic avenue for restoring epithelial barrier dysfunction in mucosal inflammation.

Public Health Relevance

Immune barrier impairment leads to chronic mucosal diseases in the susceptible subjects. Stem cell therapy has recently achieved many successful cases in the treatment of immune barrier loss. Our current study is to determine whether STAT5, a transcription factor, increases the production of stem cells to regenerate impaired cells for repairing tissue barrier.

Agency
National Institute of Health (NIH)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AI103388-02
Application #
8610878
Study Section
Gastrointestinal Mucosal Pathobiology Study Section (GMPB)
Program Officer
Rothermel, Annette L
Project Start
Project End
Budget Start
Budget End
Support Year
2
Fiscal Year
2014
Total Cost
Indirect Cost
City
Cincinnati
State
OH
Country
United States
Zip Code
45229
Zhang, Rongli; Gilbert, Shila; Yao, Xinsheng et al. (2015) Natural compound methyl protodioscin protects against intestinal inflammation through modulation of intestinal immune responses. Pharmacol Res Perspect 3:e00118
Han, Shuxin; Han, Sean Shuxin; Zhang, Rongli et al. (2015) Circadian control of bile acid synthesis by a KLF15-Fgf15 axis. Nat Commun 6:7231
Gilbert, Shila; Nivarthi, Harini; Mayhew, Christopher N et al. (2015) Activated STAT5 confers resistance to intestinal injury by increasing intestinal stem cell proliferation and regeneration. Stem Cell Reports 4:209-25
Yang, Fan; Zhou, Lei; Wang, Qiguang et al. (2014) NEXN inhibits GATA4 and leads to atrial septal defects in mice and humans. Cardiovasc Res 103:228-37
Melendez, Jaime; Liu, Ming; Sampson, Leesa et al. (2013) Cdc42 coordinates proliferation, polarity, migration, and differentiation of small intestinal epithelial cells in mice. Gastroenterology 145:808-19
Gilbert, Shila; Zhang, Rongli; Denson, Lee et al. (2012) Enterocyte STAT5 promotes mucosal wound healing via suppression of myosin light chain kinase-mediated loss of barrier function and inflammation. EMBO Mol Med 4:109-24