MCExtrusion · Mechanisms of Cell Extrusion controlling Tissue Homeostasis in the Intestine
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2021-06-01 → 2023-05-31
- EU contribution
- €187,572
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Mechanisms of Cell Extrusion controlling Tissue Homeostasis in the Intestine
The small intestine is an integral component of the gastrointestinal tract and responsible for the absorption of nutrients from ingested food within the gut lumen. Its distinct anatomy supports this role: The intestinal epithelium is folded into long tissue protrusions containing specialized cells that for example absorb nutrients and cells that secrete mucus. At the same time the intestinal epithelium functions as a protective barrier shielding the underlying tissue from the harsh environment of the gut lumen containing a high pathogenic load. It is therefore exposed to environmental and internal stresses to which it responds by dynamic cell remodelling. The intestine is among the tissues with the fastest turnover of cells revealing a precise orchestration of cell production and removal. Unbalancing of this equilibrium results in severe pathologies, as excessive proliferation causes tissue overgrowth and excessive cell removal compromises the epithelium’s barrier function. Many human pathogens distort this equilibrium either by preventing the removal of infected intestinal cells to allow for bacterial replication or by inducing removal of healthy cells to enable the penetration of the intestinal barrier. Excessive removal of cells from the intestine affects the anatomy of the intestine and compromises its digestive function. This is also hallmark of certain chronic diseases such as inflammatory bowel disease highlighting the importance of cell extrusion for intact tissue homeostasis. Despite the importance of controlled cell extrusion for maintaining the structure and function of the intestine, remarkably little is known about its regulation. With this research I investigate biological mechanisms underlying the regulation of cell extrusion in the intestine. Cells might either commit to extrusion through specific genetic programs or local tissue mechanical constraints might force the extrusion of otherwise indistinguishable cells. I aimed to characterize cell extrusion and identify gene networks that regulate it. At the same time, I investigated the role of mechanical forces for cell extrusion using precision methods including optogenetics and laser microsurgery.
Data: CORDIS, © European Union
Project objective
The intestinal epithelium undergoes continuous self-renewal through coordination of cell proliferation in the crypt and cell removal in the villus region. The aim of this project is to elucidate the mechanisms controlling the removal of differentiated cells from the villus. Preliminary data indicate that most extruding cells are non-apoptotic suggesting alternative mechanisms regulating this key homeostatic event. Cells might either commit to extrusion through specific differentiation programs or local tissue mechanical constraints might force the extrusion of otherwise indistinguishable cells. Feedback between cell fate and mechanical constraints can be also envisaged. Here I propose to identify genes that control cell extrusion by analyzing the dynamic transcriptomic signature of the mouse intestinal epithelium using nascent mRNA sequencing (scEU-seq) and pharmacologic inhibition of candidate pathways in intestinal organoids. Target genes will be functionally validated by a CRISPR-Cas9-mediated knockout screen. This analysis will be flanked by experiments investigating a potential role of tissue-scale mechanical forces in cell extrusion. I will measure the mechanical properties of the intestinal epithelium and obtain a detailed description of the morphological dynamics characterizing cell extrusion using live imaging and 3D-shape reconstruction. Precise manipulation of cortical tension by means of laser ablation combined with subcellular optogenetics will be used to functionally perturb tissue mechanics and reveal the impact of cell contractility and tissue tension on the extrusion process. Collectively, this project will help understanding how tissue homeostasis in the intestinal epithelium is maintained and dissect the relative contribution of genetic signaling circuits and tissue mechanics in regulating cell extrusion.
Original text from CORDIS.
Participants
- KONINKLIJKE NEDERLANDSE AKADEMIE VAN WETENSCHAPPEN - KNAW · AMSTERDAMCoordinatorNetherlands
Links
Data: CORDIS, © European Union