How do cells know where to position themselves and where to accumulate in order to carry out their functions correctly within each organ? Researchers with the Colorectal Cancer Lab at IRB Barcelona have revealed the molecular mechanisms responsible for organizing the intestinal epithelium into distinct comportments, defined by frontiers or territories. The study, headed by Eduard Batlle, coordinator of the Oncology Programme at IRB Barcelona and ICREA Research Professor, is published in today's online version of the Journal Nature Cell Biology, part of the prestigious editorial group Nature.
The organization of tissues and organs in the human body can be compared to a very complex and sophisticated engine, whose structure is maintained by positioning its components (cells) in a very precise way. Errors in the assembly (location) of the components might lead to changes in the function of the engine (tissue or organ).
New protein complexes that position cells in the right place
Complex tissues and organs require the separation of diverse cells types into separate zones in order to maintain their architecture. In the case of the intestinal epithelium, the lower part of the invaginations formed by the epithelium, called crypts, contains stem cells that regenerate tissue, while the upper part holds differentiated cells that are responsible for nutrient absorption.
The so-called EphB receptors, present in the cells at the bottom of the crypts, bind to Ephrin ligands located mainly in differentiated cells in the upper part of the intestinal epithelium. The ligand-receptor binding occurs at the frontier between the two cell populations and controls cell positioning in the tissue. However, until now, the way in which these ligand-receptor bindings instruct cells to position themselves in one place or another was unknown.
The results of this study demonstrate that EphB-ephrin bindings activate the metaloprotease
|Contact: Nuria Noriega|
Institute for Research in Biomedicine (IRB Barcelona)