TNFα expressed on the surface of microparticles modulates endothelial cell fate in rheumatoid arthritis

Arthritis Research & Therapy, Dec 2018

Rheumatoid arthritis (RA) is associated with a high prevalence of atherosclerosis. Recently increased levels of microparticles (MPs) have been reported in patients with RA. MPs could represent a link between autoimmunity and endothelial dysfunction by expressing tumor necrosis factor alpha (TNFα), a key cytokine involved in the pathogenesis of RA, altering endothelial apoptosis and autophagy. The aim of this study was to investigate TNFα expression on MPs and its relationship with endothelial cell fate. MPs were purified from peripheral blood from 20 healthy controls (HC) and from 20 patients with RA, before (time (T)0) and after (T4) 4-month treatment with etanercept (ETA). Surface expression of TNFα was performed by flow cytometry analysis. EA.hy926 cells, an immortalized endothelial cell line, were treated with RA-MPs purified at T0 and at T4 and also, with RA-MPs in vitro treated with ETA. Apoptosis and autophagy were then evaluated. RA-MPs purified at T0 expressed TNFα on their surface and this expression significantly decreased at T4. Moreover, at T0 RA-MPs, significantly increased both apoptosis and autophagy levels on endothelial cells, in a dose-dependent manner. RA-MPs did not significantly change these parameters after 4 months of in vivo treatment with ETA. Our data demonstrate that MPs isolated from patients with RA exert a pathological effect on endothelial cells by TNFα expressed on their surface. In vivo and in vitro treatment with ETA modulates this effect, suggesting anti-TNF therapy protects against endothelial damage in patients with RA.

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TNFα expressed on the surface of microparticles modulates endothelial cell fate in rheumatoid arthritis

Research article Open Access TNFα expressed on the surface of microparticles modulates endothelial cell fate in rheumatoid arthritis Cristiana Barbati1Email authorView ORCID ID profile, Marta Vomero1, Tania Colasanti1, Marco Diociaiuti2, Fulvia Ceccarelli1, Sara Ferrigno1, Annacarla Finucci1, Francesca Miranda1, Lucia Novelli1, Carlo Perricone1, Francesca Romana Spinelli1, Simona Truglia1, Fabrizio Conti1, Guido Valesini1 and Cristiano Alessandri1 Arthritis Research & Therapy201820:273 https://doi.org/10.1186/s13075-018-1768-8 ©  The Author(s). 2018 Received: 26 July 2018Accepted: 13 November 2018Published: 7 December 2018 Abstract Background Rheumatoid arthritis (RA) is associated with a high prevalence of atherosclerosis. Recently increased levels of microparticles (MPs) have been reported in patients with RA. MPs could represent a link between autoimmunity and endothelial dysfunction by expressing tumor necrosis factor alpha (TNFα), a key cytokine involved in the pathogenesis of RA, altering endothelial apoptosis and autophagy. The aim of this study was to investigate TNFα expression on MPs and its relationship with endothelial cell fate. Methods MPs were purified from peripheral blood from 20 healthy controls (HC) and from 20 patients with RA, before (time (T)0) and after (T4) 4-month treatment with etanercept (ETA). Surface expression of TNFα was performed by flow cytometry analysis. EA.hy926 cells, an immortalized endothelial cell line, were treated with RA-MPs purified at T0 and at T4 and also, with RA-MPs in vitro treated with ETA. Apoptosis and autophagy were then evaluated. Results RA-MPs purified at T0 expressed TNFα on their surface and this expression significantly decreased at T4. Moreover, at T0 RA-MPs, significantly increased both apoptosis and autophagy levels on endothelial cells, in a dose-dependent manner. RA-MPs did not significantly change these parameters after 4 months of in vivo treatment with ETA. Conclusions Our data demonstrate that MPs isolated from patients with RA exert a pathological effect on endothelial cells by TNFα expressed on their surface. In vivo and in vitro treatment with ETA modulates this effect, suggesting anti-TNF therapy protects against endothelial damage in patients with RA. Keywords Rheumatoid arthritisMicroparticlesAutophagyEndothelial cells Background Microparticles (MPs) are small membrane vesicles (0.1–1.0 μm) released by many cell types under physiological and pathological conditions. In the past these particles were considered as inert cell debris, but recently many studies have demonstrated they could be involved in intercellular communication. Generation and scattering of MPs occurs during different biological processes, including apoptosis and cellular activation [1–3]. Due to their formation, MPs have an array of surface markers derived from their parental cell that can be used to assess their origin. Thus, MPs can transfer biological messages from parental to target cells by direct interaction with the ligands expressed on the surface of target cells and activate cascade signaling; or they can transfer proteins, messenger RNA (mRNA), micro RNA (miRNA), and bioactive lipids by fusion or internalization with target cells [4].Thus, MPs are able to modulate various biological phenomena such as cell proliferation, angiogenesis, immune response, and coagulation [5, 6]. Increased levels of MPs have been reported in various pathological conditions including infections, malignancies, and autoimmune diseases, such as rheumatoid arthritis (RA) [7]. RA is an autoimmune systemic inflammatory disease characterized by chronic synovial inflammation, resulting in cartilage and bone damage with accelerated atherosclerosis and increased mortality [8]. Tumor necrosis factor alpha (TNFα) is the main cytokine involved in the pathogenesis of RA and many studies agree on the pro-atherogenic effect of TNFα in patients with RA. TNF-inhibitors are effective treatments for joint inflammation in RA; however, very little is known about their effect on atherosclerosis and endothelial dysfunction, which occur in this disease. Previous studies have shown that TNF-inhibitors can improve endothelial function and decrease cardiovascular events in responder patients, highlighting the pro-atherogenic effect of TNFα in RA [9, 10]. According to the literature, MPs could also have a role in endothelial dysfunction, contributing to atherosclerosis in patients with RA [11]. Moreover, an imbalance between apoptosis and autophagy mechanisms seems to be involved in endothelial dysfunction. Apoptosis is programmed cell death and many studies suggest the involvement of endothelial apoptosis in the atherosclerosis process [12]. Autophagy is a reparative process by which cytoplasmic components are sequestered in double-membrane vesicles and degraded on fusion with lysosomal compartments. It has been shown that basal autophagy is essential to proper va (...truncated)


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Cristiana Barbati, Marta Vomero, Tania Colasanti, Marco Diociaiuti, Fulvia Ceccarelli, Sara Ferrigno, Annacarla Finucci, Francesca Miranda, Lucia Novelli, Carlo Perricone, Francesca Romana Spinelli, Simona Truglia, Fabrizio Conti, Guido Valesini, Cristiano Alessandri. TNFα expressed on the surface of microparticles modulates endothelial cell fate in rheumatoid arthritis, Arthritis Research & Therapy, 2018, pp. 273, Volume 20, Issue 1, DOI: 10.1186/s13075-018-1768-8