Notch signaling regulates gastric antral LGR5 stem cell function.
The major signaling pathways regulating gastric stem cells are unknown. Here we report that Notch signaling is essential for homeostasis of LGR5(+) antral stem cells. Pathway inhibition reduced proliferation of gastric stem and progenitor cells, while activation increased proliferation. Notch dysregulation also altered differentiation, with inhibition inducing mucous and endocrine cell differentiation while activation reduced differentiation. Analysis of gastric organoids demonstrated that Notch signaling was intrinsic to the epithelium and regulated growth. Furthermore, in vivo Notch manipulation affected the efficiency of organoid initiation from glands and single Lgr5-GFP stem cells, suggesting regulation of stem cell function. Strikingly, constitutive Notch activation in LGR5(+) stem cells induced tissue expansion via antral gland fission. Lineage tracing using a multi-colored reporter demonstrated that Notch-activated stem cells rapidly generate monoclonal glands, suggesting a competitive advantage over unmanipulated stem cells. Notch activation was associated with increased mTOR signaling, and mTORC1 inhibition normalized NICD-induced increases in proliferation and gland fission. Chronic Notch activation induced undifferentiated, hyper-proliferative polyps, suggesting that aberrant activation of Notch in gastric stem cells may contribute to gastric tumorigenesis.
Department of Molecular & Integrative Physiology, The University of Michigan Medical School, Ann Arbor, MI, USA.
Elise S
ES
Demitrack
Department of Molecular & Integrative Physiology, The University of Michigan Medical School, Ann Arbor, MI, USA.
Gail B
GB
Gifford
Department of Molecular & Integrative Physiology, The University of Michigan Medical School, Ann Arbor, MI, USA.
Theresa M
TM
Keeley
Department of Molecular & Integrative Physiology, The University of Michigan Medical School, Ann Arbor, MI, USA.
Alexis J
AJ
Carulli
Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.
Kelli L
KL
VanDussen
Department of Pathology, The University of Michigan Medical School, Ann Arbor, MI, USA.
Dafydd
D
Thomas
Department of Pathology, The University of Michigan Medical School, Ann Arbor, MI, USA Department of Internal Medicine, The University of Michigan Medical School, Ann Arbor, MI, USA.
Thomas J
TJ
Giordano
Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA.
Zhenyi
Z
Liu
Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
Raphael
R
Kopan
Department of Molecular & Integrative Physiology, The University of Michigan Medical School, Ann Arbor, MI, USA Department of Internal Medicine, The University of Michigan Medical School, Ann Arbor, MI, USA lcsam@umich.edu.
Linda C
LC
Samuelson
D000704:Analysis of Variance; D000818:Animals; D001837:Body Weights and Measures; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage / Q000502:physiology; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D006652:Histological Techniques; D006706:Homeostasis / Q000502:physiology*; D017403:In Situ Hybridization; D051379:Mice; D018613:Microscopy, Confocal; D011706:Pyloric Antrum / Q000166:cytology* / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D051880:Receptors, Notch / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D013234:Stem Cells / Q000378:metabolism*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism
C493597:Lgr5 protein, mouse; D043562:Receptors, G-Protein-Coupled; D051880:Receptors, Notch; C546843:mTOR protein, mouse; D058570:TOR Serine-Threonine Kinases
gastric cancer; gastric organoids; gastric stem cells; gland fission; mTOR