title: Muramyl dipeptide: Not just another brick in the wall.
abstract: The robust expression of microbial pattern recognition receptors such as TLR4 and Nod2 in intestinal stem cells reflects an active communication dynamic between the host and the gut microbiota. A new study reveals that muramyl dipeptide, the bacterial cell wall peptidoglycan motif, activates Nod2 within crypt base columnar Lgr5-positive stem cells and promotes their survival. Apart from the immediate relevance to the growth of organoids for in vitro experiments, the study raises new questions about the molecular mechanisms whereby gut microbes influence intestinal physiology.
authors: School of Animal & Comparative Biomedical Sciences; University of Arizona; Tucson, AZ USA.
authors: V K
authors: VK
authors: Viswanathan
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000378:metabolism*; D001419:Bacteria / Q000166:cytology / Q000276:immunology*; D002470:Cell Survival / Q000187:drug effects; D002473:Cell Wall / Q000276:immunology*; D007413:Intestinal Mucosa / Q000276:immunology / Q000382:microbiology; D053473:Nod2 Signaling Adaptor Protein / Q000378:metabolism*; D010457:Peptidoglycan / Q000276:immunology*; D013234:Stem Cells / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology*
chemical_list: C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein; D010457:Peptidoglycan; D000119:Acetylmuramyl-Alanyl-Isoglutamine
keywords: Lgr5; Nod2; muramyl dipeptide; organoids; stem cells