Understanding the evolution of regeneration-permissive gene expression and positional memory in Axolotl limb regeneration

Informazioni relative al progetto

RegGeneMems

ID dell’accordo di sovvenzione: 742046

DOI

10.3030/742046

Progetto chiuso

Data della firma CE 10 Maggio 2017

Data di avvio 1 Gennaio 2018

Data di completamento 31 Ottobre 2023

Finanziato da

• EXCELLENT SCIENCE - European Research Council (ERC)

Costo totale

€ 2 325 659,00

Contributo UE

€ 2 325 659,00

Coordinato da

FORSCHUNGSINSTITUT FUR MOLEKULARE PATHOLOGIE GESELLSCHAFT MBH
Austria

Periodic Reporting for period 4 - RegGeneMems (Understanding the evolution of regeneration-permissive gene expression and positional memory in Axolotl limb regeneration)

Periodo di rendicontazione: 2022-07-01 al 2023-10-31

Sintesi del contesto e degli obiettivi generali del progetto

We are working on understanding how, over evolution, the axolotl, which has a body plan similar to humans, evolved the ability to regenerate the limb. We are working on a specific growth factor that has changed its expression characteristics in axolotl compared to all other four-legged animals. We testing how this changed expression affects regeneration, and whether converting the pattern in axolotl to the mammalian one prevents regeneration.
This knowledge will help us to engineer adult sized tissues to replace damaged tissues.
Our goal is to understand how a successful example of regeneration works in order to understand how to promote regeneration in non-regenerative contexts.

Lavoro eseguito dall’inizio del progetto fino alla fine del periodo coperto dalla relazione e principali risultati finora ottenuti

We have identified how the expression of the growth factor fgf8 changes over regeneration and in different sized animals. We have identified the genetic sequences that control its expression, and compared this to the human equivalent sequences. We showed that a signalling pathway called Wnt and its downstream components have shifted from epidermis to mesenchyme in axolotl to control this change in fgf8 expression. Fgf8 and Shh are turned on in opposite sides of the regeneration blastema to control thumb versus pinky formation. We found the factor, Hand2, in posterior adult fibroblasts tell them whether they should turn on Fgf8 or Shh during regeneration. Regenerating cells can be influenced by Shh itself to determine the exact proportions of anterior and posterior cells. The identification of these factors can be exploited in mammalian stem cells to engineer limb tissue.

Progressi oltre lo stato dell’arte e potenziale impatto previsto (incluso l’impatto socioeconomico e le implicazioni sociali più ampie del progetto fino ad ora)

We have deveoped methods to image molecules in very large tissues that allow us to look at how these signalling factors are expressed in large, regenerating tissues. We have also developed spheroid cultures that allow us to study the molecular control of how Fgf8 and Shh hedgehog become upregulated in anterior and posterior cells. We now have exquisite control of cell identity along the anterior-posterior axis of the limb, which informs us how to engineer tissues.

Lineage analysis during regeneration of cells that had expressed sonic hedgehog during development