Portal fibroblasts with mesenchymal stem cell features form a reservoir of proliferative myofibroblasts in liver fibrosis

Lin Lei (1, 2) , Alix Bruneau (3) , Haquima El Mourabit (1, 2) , Justine Guégan (4, 5) , Trine Folseraas (6) , Sara Lemoinne (1, 2, 7) , Tom Hemming Karlsen (6) , Bénédicte Hoareau (8, 9) , Romain Morichon (1, 2) , Ester Gonzalez‐sanchez (2, 1) , Claire Goumard (1, 2, 10) , Vlad Ratziu (10) , Pierre Charbord (11) , Jérémie Gautheron (2, 1) , Frank Tacke (3) , Thierry Jaffredo (11) , Axelle Cadoret (1, 2) , Chantal Housset (1, 2, 7)

1 CRSA - Centre de Recherche Saint-Antoine
2 IHU ICAN - Institut de Cardiométabolisme et Nutrition = Institute of Cardiometabolism and Nutrition [CHU Pitié Salpêtrière]
3 Charité - UniversitätsMedizin = Charité - University Hospital [Berlin]
4 ICM - Institut du Cerveau = Paris Brain Institute
5 Plateforme iCONICS [ICM Paris]
6 Oslo University Hospital [Oslo]
7 CHU Saint-Antoine [AP-HP]
8 PASS - Unité Mixte de Service Production et Analyse de données en Sciences de la vie et en Santé
9 PASS-CYPS - Cytométrie Pitié-Salpêtrière
10 CHU Pitié-Salpêtrière [AP-HP]
11 IBPS - Institut de Biologie Paris Seine

Background and Aims: In liver fibrosis, myofibroblasts derive from HSCs and as yet undefined mesenchymal cells. We aimed to identify portal mesenchymal progenitors of myofibroblasts. Approach and Results: Portal mesenchymal cells were isolated from mouse bilio-vascular tree and analyzed by single-cell RNA-sequencing. Thereby, we uncovered the landscape of portal mesenchymal cells in homeostatic mouse liver. Trajectory analysis enabled inferring a small cell population further defined by surface markers used to isolate it. This population consisted of portal fibroblasts with mesenchymal stem cell features (PMSCs), i.e., high clonogenicity and trilineage differentiation potential, that generated proliferative myofibroblasts, contrasting with nonproliferative HSC-derived myofibroblasts (-MF). Using bulk RNA-sequencing, we built oligogene signatures of the two cell populations that remained discriminant across myofibroblastic differentiation. SLIT2, a prototypical gene of PMSC/PMSC-MF signature, mediated profibrotic and angiogenic effects of these cells, which conditioned medium promoted HSC survival and endothelial cell tubulogenesis. Using PMSC/PMSC-MF 7-gene signature and slit guidance ligand 2 fluorescent in situ hybridization, we showed that PMSCs display a perivascular portal distribution in homeostatic liver and largely expand with fibrosis progression, contributing to the myofibroblast populations that form fibrotic septa, preferentially along neovessels, in murine and human liver disorders, irrespective of etiology. We also unraveled a 6-gene expression signature of HSCs/HSC-MFs that did not vary in these disorders, consistent with their low proliferation rate. Conclusions: PMSCs form a small reservoir of expansive myofibroblasts, which, in interaction with neovessels and HSC-MFs that mainly arise through differentiation from a preexisting pool, underlie the formation of fibrotic septa in all types of liver diseases

Keywords: Cirrhosis; Hepatic stellate cells; Perivascular; Single-cell RNA-sequencing

Domains: Hépatology and Gastroenterology; Subcellular Processes [q-bio.SC]

Lin Lei, Alix Bruneau, Haquima El Mourabit, Justine Guégan, Trine Folseraas, et al.. Portal fibroblasts with mesenchymal stem cell features form a reservoir of proliferative myofibroblasts in liver fibrosis. Hepatology, inPress, ⟨10.1002/hep.32456⟩. ⟨hal-03667547⟩