Regulation of epithelial-cells renewal by basement membrane protein composition and stiffness during gut homeostasis

Project Information

ReGutBM

Grant agreement ID: 101066253

DOI

10.3030/101066253

Project closed

EC signature date 7 July 2022

Start date 1 September 2023

End date 31 August 2025

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 211 754,88

Coordinated by

INSTITUT CURIE
France

Periodic Reporting for period 1 - ReGutBM (Regulation of epithelial-cells renewal by basement membrane protein composition and stiffness during gut homeostasis)

Reporting period: 2023-09-01 to 2025-08-31

Summary of the context and overall objectives of the project

The intestinal epithelium is the fastest self-renewing tissue in the human body, completely regenerating every few days. Understanding how this renewal is regulated is fundamental to biology and has implications for diseases such as inflammatory bowel disease- which can result from excessive cell extrusion that is not complemented by enough cell proliferation- or for colorectal cancer, which can result from excessive proliferation of cells that is not met by sufficient cell extrusion.
The ReGutBM project investigated whether the basement membrane—a thin layer of specialized proteins underlying intestinal epithelial cells—actively regulates epithelial cell behavior. While traditionally viewed as structural support, this research examined whether variations in basement membrane protein composition across the tissue provide chemical or mechanical signals that control when cells proliferate, migrate, extrude and die.
The project objectives were to characterize basement membrane protein composition and mechanical properties, determine whether these properties influence cell behavior, and identify the molecular pathways through which basement membrane signals regulate tissue homeostasis. This research was interdisciplinary and combined cell biology, mechanobiology, and advanced imaging to address fundamental questions about tissue regulation.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The project characterized basement membrane composition in the mouse small intestine using advanced microscopy, confirming the spatial distribution of laminin proteins, some with expression restricted to the intestinal crypt or the villus tip. However, the project showed that these changes in expression did not impact the stiffness of the tissue. To investigate whether these proteins have functional significance, in-vivo mouse models were used, in combination with engineered substrates with controlled and patterned protein composition and organoid culture systems that mimic intestinal tissue organization.
A key finding was that specific basement membrane proteins regulate the rate of epithelial cell extrusion—the process by which cells are shed from tissue, and can occur to both live or dead cells. This regulation occurs through activation of specific cellular signaling pathways, providing molecular insight into how extracellular matrix composition influences tissue homeostasis.

During the work on the project, the fellow acquired extensive skills including working with intestinal organoid cultures, microfabrication, protein patterning, atomic force microscopy, advanced live-imaging and confocal microscopy, as well as development of computational analysis pipelines. A detailed methodological protocol was published, providing tools now being adopted by other laboratories. The quantification frameworks developed are being applied to additional projects, demonstrating broader utility. These achievements position the researcher to establish an independent research team, further investigating extracellular matrix regulation of tissue behavior.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The project establishes the basement membrane as an active regulatory component of tissue microenvironment, not merely passive structure. This advances understanding across multiple areas.
First, it demonstrates that spatial variations in basement membrane composition create functional zones governing distinct cell behaviors. This framework helps explain how tissues organize and maintain appropriate cell numbers despite constant turnover.
Second, identifying molecular pathways linking basement membrane composition to cellular responses provides mechanistic insight bridging extracellular and intracellular biology, essential for developing targeted interventions.
Third, the methodological advances both in vivo and in vitro- provide tools and practices for investigating how physical and biochemical properties of cellular microenvironment influence tissue function.
These findings open research directions examining whether similar mechanisms operate in other tissues and whether their disruption contributes to disease. Translation toward therapeutic applications requires additional research, including validation in human systems and investigation of disease-associated basement membrane alterations. Nevertheless, this foundational understanding represents an essential step toward such goals.

netafelsenthalintestine.jpg