It is of major significance that we have discovered that during complete skin regeneration in the spiny mouse, Acomys, the skeletal muscle of the lower layers of the skin are regenerated despite the removal of all the connective tissue components of this tissue. This is in contrast to humans and the lab mouse, Mus, where the skin fibroses with a scar and no muscle is regenerated. The medical importance of this observation for both civilians and soldiers is profound because Acomys can also perfectly regenerate damage through the middle of a muscle belly. We propose here to take our recent microarray, qPCR and RNA-seq analysis of whole skin regeneration to the single cell level with single cell RNA-Seq (scRNA-seq) so that gene regulation patterns of the individual tissue components which make up the regenerating skin can be identified. This project will develop and utilize immunophenotyping panels and comprehensive single cell gene expression assays scRNA-Seq to resolve expression of individual cells and assess changes in tissue cell sub-populations across time between the Mus (scarring) and Acomys (regenerating). The outcome of this project is to identify the gene regulatory networks which characterize individual populations in a regenerating environment in contrast to a scarring environment, and to provide this as a resource to the regenerative medicine community. Future directions will be centered on functionally testing crucial genes for their ability to induce regeneration (hair follicles, sebaceous glands, skeletal muscle) in lieu of scarring with clear implications for its extrapolation to the human condition.
Our research program aims to understand the key controlling elements necessary to induce reparative regeneration in mammals and to translate this knowledge to human setting. This information is critical for the effective development of novel therapeutic targets to reduce fibrosis, abrogate scarring and induce or enable skin and muscle regeneration. Our proposed research will identify differences in tissue cell population structure and gene expression at the single-cell level during scar-free wound repair in the regenerating mammal, Acomys, which will ultimately may lead to the therapeutic development of molecules which can promote regeneration in lieu of fibrosis and pave the way towards the long-term goal of understanding how to induce in vivo tissue regeneration in humans.