Federica Esposito

Dottoressa di ricerca

ciclo: XXXVI

supervisore: Dott.ssa Valentina Saccone

Titolo della tesi: Study of IntegrinB1 transported by FAPs derived extracellular vesicles in correcting asymmetric division of dystrophic satellite cells.

-RAZIONALE: Duchenne muscular dystrophy (DMD) is a rare neuromuscular disorder caused by mutations in the dystrophin gene, resulting in the lack of the homonymous protein, which leads to progressive muscle degeneration. Our group has evidenced the potential of epigenetic drugs, Thricostatin A, in improving muscle regeneration and counteracting DMD progression by inhibiting the Histone Deacetylases. Through our studies on dystrophic mice, we found that communication between fibro adipogenic progenitors (FAPs) and muscle stem cells (MuSCs), is mediated by extracellular vesicles (EVs) and that the pharmacological treatment with TSA fine-tunes FAPs-derived EV content, by making it pro-regenerative. We observed that the genetic material conveyed within EVs can be transferred to dystrophic MuSCs influencing their activation, differentiation, and counteracting the DMD muscle degeneration. We deepened the pro-regenerative signature of EVs by exploring the protein content of FAPs-derived EVs after TSA treatment. Noteworthy, by proteomic analysis, we revealed Integrin Beta 1 (Itg𝛽1) as one of the most up-regulated proteins in TSA-EVs. Itg𝛽1 governs the maintenance of MuSCs quiescence and drives their proliferation and self-renewal during muscle regeneration. The link between Itg𝛽1 and DMD is strong indeed dystrophic MuSCs have unbalanced integrin dimer a7𝛽1 with a decrease of 𝛽1 chain. -GENERAL OBJECTIVES: The aim of this project is to study the importance of an increased amount of Itg𝛽1 in EVs, after FAPs treatment with TSA, released to dystrophic satellite cells. Our hypothesis is that TSA-EVs are capable of releasing and reconstituting the integrin dimer a7𝛽1 on the satellite cells membrane, thereby correcting processes, such as asymmetric division, which are abnormally activated under pathological conditions as DMD. Furthermore, we aim to investigate the role of Itg𝛽1 in contributing to the beneficial effects of TSA-EVs on the dystrophic muscle environment, as we have previously demonstrated. -EXPERIMENTAL DESIGN AND METHODS To investigate the of Itgb1 protein transported by EVs to dystrophic MuSCs membrane, we used in all our experiments both TSA-EVs (released by FAPs from young mdx mice after 15 days of treatment with TSA), and TSA-EVs with reduced levels of Itg𝛽1 (obtained transfecting FAPs isolated from TSA-treated mdx muscles with a custom siRNA for Itg𝛽1). In detail, to assess the impact of TSA-EVs on MuSCs activation, we set up co-culture experiments by adding the vesicles on single freshly isolated myofibers from the gastrocnemius of young mdx mice. We evaluated at two different time points (24h and 48h) the effect of TSA-EVs and TSA-EV Itg𝛽1 KO on MuSCs. Specifically, we evaluate their influence on the activation of polarity and asymmetric division of MuSCs, as well as the determination of cell fate. Furthermore, to determine whether the amount of Itg𝛽1 in the TSA-EVs is a key component of their regenerative potential, we performed EV transplantation in the aforementioned conditions in muscles of DMD animals and analyzed the regeneration process through histological analysis. -RESULTS: Our findings suggest that the TSA-EVs can establish the formation on dimer a7𝛽1 on the MuSCs surface, regulating the spurious and pathological activation of Itg𝛽1-signaling, which is a feature of a dystrophic environment. Furthermore, Itg𝛽1 loaded onto the external membrane of TSA-EVs is essential in preventing the spurious and aberrant MuSCs proliferation and differentiation, thereby correcting their polarization and restoring the correct asymmetric cell division restoring their correct fate. Moreover, we discovered that Itgb1 released by EVs to dystrophic MuSCs contributes to the beneficial effects of TSA-EVs on the muscle environment. -CONCLUSIONS: These significant results pave the way for deeply understanding the role of Itgb1 loaded in TSA-EVs, which could help to restore muscle architecture, stabilize the MuSCs niche, and preserve muscle tissue.

Produzione scientifica

11573/1556116 - 2021 - Mesenchymal stromal cells and their secretome: new therapeutic perspectives for skeletal muscle regeneration
Sandona, M.; Di Pietro, L.; Esposito, F.; Ventura, A.; Silini, A. R.; Parolini, O.; Saccone, V. - 01g Articolo di rassegna (Review)
rivista: FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY (Lausanne : Frontiers Editorial Office, 2013-) pp. 1-16 - issn: 2296-4185 - wos: WOS:000654967000001 (47) - scopus: 2-s2.0-85107071814 (52)

11573/1556114 - 2020 - Cripto shapes macrophage plasticity and restricts EndMT in injured and diseased skeletal muscle
Iavarone, Francescopaolo; Guardiola, Ombretta; Scagliola, Alessandra; Andolfi, Gennaro; Esposito, Federica; Serrano, Antonio; Perdiguero, Eusebio; Brunelli, Silvia; Muñoz-Cánoves, Pura; Minchiotti, Gabriella - 01a Articolo in rivista
rivista: EMBO REPORTS (Oxford : Oxford University Press, 2000-) pp. 1-17 - issn: 1469-221X - wos: WOS:000516771900001 (12) - scopus: 2-s2.0-85080124203 (15)

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