AUTHOR=Farina Luciapia , Minnone Gaetana , Alivernini Stefano , Caiello Ivan , MacDonald Lucy , Soligo Marzia , Manni Luigi , Tolusso Barbara , Coppola Simona , Zara Erika , Conti Libenzio Adrian , Aquilani Angela , Magni-Manzoni Silvia , Kurowska-Stolarska Mariola , Gremese Elisa , De Benedetti Fabrizio , Bracci-Laudiero Luisa TITLE=Pro Nerve Growth Factor and Its Receptor p75NTR Activate Inflammatory Responses in Synovial Fibroblasts: A Novel Targetable Mechanism in Arthritis JOURNAL=Frontiers in Immunology VOLUME=Volume 13 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.818630 DOI=10.3389/fimmu.2022.818630 ISSN=1664-3224 ABSTRACT=
We have recently provided new evidence for a role of p75NTR receptor and its preferential ligand proNGF in amplifying inflammatory responses in synovial mononuclear cells of chronic arthritis patients. In the present study, to better investigate how activation of the p75NTR/proNGF axis impacts synovial inflammation, we have studied the effects of proNGF on fibroblast-like synoviocytes (FLS), which play a central role in modulating local immune responses and in activating pro-inflammatory pathways. Using single cell RNA sequencing in synovial tissues from active and treatment-naïve rheumatoid arthritis (RA) patients, we demonstrated that p75NTR and sortilin, which form a high affinity receptor complex for proNGF, are highly expressed in PRG4pos lining and THY1posCOL1A1pos sublining fibroblast clusters in RA synovia but decreased in RA patients in sustained clinical remission. In