Dissecting a stepwise principle of cellular diversification to instruct regeneration in the enteric nervous system

Project Information

divENSify

Grant agreement ID: 101045026

DOI

10.3030/101045026

EC signature date 8 April 2022

Start date 1 September 2022

End date 31 August 2027

Funded under

• European Research Council (ERC)

Total cost

€ 1 999 981,00

EU contribution

€ 1 999 981,00

Coordinated by

KAROLINSKA INSTITUTET
Sweden

Periodic Reporting for period 1 - divENSify (Dissecting a stepwise principle of cellular diversification to instruct regeneration in the enteric nervous system)

Reporting period: 2022-09-01 to 2025-02-28

Summary of the context and overall objectives of the project

The gastrointestinal tract is equipped with an own intrinsic nervous system. Also denoted the “Brain in the Gut”, the enteric nervous system (ENS) acts independently of the central nervous system (CNS) by virtue of its 500 million neurons and glia that organize in full circuits across the intestines. Deficiencies within the ENS contribute to congenital, degenerative and inflammatory disorders that lack satisfactory treatment. Recently, it has been shown that enteric glia cells can convert into neurons following injury or disease, igniting hope for the development of regenerative therapies targeting gut disorders. Recovery, however, will depend on achieving a balanced neuronal constitution, emphasising the importance to define enteric neuron types and understand their development. My lab has used transcriptomics (gene expression analysis) to establish the cellular composition of the ENS in the murine gut, identifying 12 subclasses of neurons. Further transcriptome analysis at embryonic stages revealed that enteric stem cells undergoing differentiation initially only undertake one out of two neuronal identities and thereafter diversify further to other classes through identity conversions. divENSify builds on these fundamental discoveries and aims to further explore both developmental and regenerative processes in the mouse ENS. More specifically, in the first part of the project we aim to determine the detailed gene regulatory networks that governs the identity acquisition in the developing ENS by further transcriptomic (gene expression) and epigenetic (gene accessibility) analysis as well as in utero (fetal) gene manipulation experiments. In the second part of divENSify, we are deducing the innate ability of the ENS to regenerate and ask which neuron types can be generated, and whether differentiation occurs through similar mechanisms as observed during the embryonic development. In the very last part of divENSify we will attempt to generate specific neuron types in the adult gut guided by information gained from previous subprojects.

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

We have to date performed extensive transcriptome (gene expression) and epigenetic (gene accessibility) profiling encompassing the mouse gut development. Our data suggest coherent developmental mechanisms at early and late stages as well as between different regions of the gut. We have performed functional testing of transcription factors, indicating specific roles in either general differentiation of stem cells to neurons or the diversification of neuron identities. Implementation of new mouse models to study the differentiation of glia to neurons in the adult gut is ongoing as well as spatial transcriptomic methods, which would allow the determination of gene expression directly in developing and adult gut tissue.

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)

In this midterm report we have met some goals set up for divENSify such as a transcriptional cell atlas of the developing ENS, optimization of an in utero gene manipulation technology and implementation of regenerative animal models in the ENS. We expect that these methods will be widely used by the research community to further the general knowledge of the development and regeneration within the ENS. By the end of the project we expect that we will transform our comprehension of neuron identity acquisition in the embryonic and adult gut and provide proof-of-principle experiments that open for regenerative therapy of neurological gut disorders.