Leucine-Rich Repeat-Containing G-Protein-Coupled Receptors as Markers of Adult Stem Cells

The document from May 1, 2010, discusses the identification and role of leucine-rich repeat-containing G-protein-coupled receptors (LGRs), specifically Lgr5 and Lgr6, as markers of adult stem cells in various tissues, including the gastrointestinal tract, stomach, and hair follicles. Lgr5+ cells are capable of self-renewal and generating all cell types of the epithelium, while Lgr6+ cells are multipotent skin stem cells involved in wound repair and hair follicle regeneration. The document also highlights the development of an intestinal culture system that allows single stem cells to generate crypt-villus organoids, maintaining basic epithelial architecture. The Lgr5tm1(cre/ESRI)cle mouse model has shown that Lgr5+ stem cells can originate intestinal cancer. The document emphasizes the importance of identifying ligands for Lgr5 and Lgr6 to understand stem cell functions and signaling, and suggests that these stem cells may be developed for regenerative medicine. It also notes the low expression levels of Lgr5 and Lgr6, which complicates their study, and the potential use of additional markers like OlfM4 for clinical studies. The document concludes that further research is needed to fully understand the functions and signaling pathways of Lgr4 and Lgr5, and their significant roles in tissue development and stem cell maintenance.