Stem Cell Microenvironments in Planarians Are Regulated by Multiple Cell Types Across Three Germ Layers

30 septembre - 14h30 - 23h59

Centre de recherche - Paris

Amphithéâtre Constant-Burg - 12 rue Lhomond, Paris 5e

12 rue Lhomond, Paris 5ème

Description

The functions of stem cells during tissue regeneration are partly regulated by extrinsic signals from the surrounding microenvironment composed of an extracellular matrix (ECM), making it critical to understand these signals for the advancement of regenerative medicine. Recently, many studies using vertebrates have demonstrated that stem cell microenvironments are maintained by different cell types during tissue regeneration. However, these models have limitations, including limited access to stem cells, a small number of stem cells, and difficulty in studying gene function on a large scale. Therefore, we have chosen planarians, Schmidtea mediterranea, to study stem cell microenvironment during tissue regeneration as they have accessible/numerous adult pluripotent stem cells, whole-body regeneration, extensive conservation of ECM components, and are amenable to high-throughput genetic screening. By employing mass spectrometry on decellularized regenerating animals, we identified protein components of the stem cell microenvironment and measured ECM gene expression during tissue regeneration using Bulk RNA-seq. We found that many proteins that contribute to stem cell microenvironment are secreted by multiple cell types during tissue regeneration. Chiefly among these are intestinal cells, whose transcriptomes appear enriched in protease gene expression early during regeneration, and muscle cells which are enriched in collagen protein deposition at later stages of regeneration. Disruption of these secretory proteins both positively and negatively affect stem cell activity. In addition, we propose the term “matrigenic cell” to describe invertebrate cells capable of expressing both core collagen and genes associated with muscle as the definition of fibroblast is ambiguous across invertebrate phyla. By this definition, matrigenic cells in planarians are found in all three germ layers, including epidermis, muscle, and intestine, and they are responsive to tissue regeneration. In summary, our findings suggest that planarians rely on cells from all three germ layers to remodel their stem cell microenvironment, with each cell type likely having different modes of action. This work lays the groundwork for understanding the cellular origin of the extracellular matrix and may shed light on how matrigenic cells evolved during metazoan evolution.

 

Ekasit K. Sonpho1, Charles A. S. Banks1, Frederick G. Mann Jr.1,2, Eric J. Ross1,2, Carolyn Brewster1,Carlos Guerrero-hernández1, Sean McKinney1, Cathy McKinney1, Jose Emmanuel Javier1, Jeff Haug1,Laurence Florens1, Alejandro Sánchez Alvarado1,2. 1 Stowers Institute for Medical Research, Kansas City, USA, 2 Howard Hughes Medical Institute, Kansas City, USA

Orateurs

Ekasit K. SONPHO

Stowers Institute for Medical Research (Kansas City, USA)

Invité(es) par

Louise DAGHER

Institut Curie

Jean-Léon MAITRE

Institut Curie

Une question sur le séminaire ?