Dottorato in MORFOGENESI E INGEGNERIA TISSUTALE

Titolo della tesi: Spatiotemporal insights into the role of glial cells in nerve and muscle repair following injury.

Recent studies have demonstrated that Plp1 positive glial cells are activated after re-innervation process, but at state-of-the-art the spatial information is lacking. Moreover, the role of glial cells in muscle tissue damage is not well known. The use of spatial transcriptomics (ST) allowed to contextualize gene expression within the real location by providing detailed information on how different muscle units act and synergize under pathological conditions. The goal is to identify possible pathways activated in glial cells after muscle damage, that define the physiological mechanisms in which they are involved. To characterize glial cells upon alteration of muscle homeostasis we decided to use two models of damage: a reversible denervation and myotoxic injury. To study the interactions of glial cells with muscle environment in health and damage condition, we used a bioinformatic tools on datasets from ST, supplemented with single cells (sc) RNA sequencing. To better define the transcriptional profile of cells in response to muscle injury we performed bulk a RNA-seq of Plp1 positive cells isolated from a generate mouse model Plp1CreERT2 tdTomatofl/fl subjected to damage. In addition, we performed co-culture experiments to confirm interaction targets. The glial cells after denervation increase the expression of factors associated with nerve growth and repair like Ngfr; instead after muscle injury they express factor associated with myotubes differentiation like Igf1. We discovered that the muscle glial cells are sensitive to the alteration of the environment and activate different pathways to support regeneration processes.