title: Interaction of differentiated human adipocytes with macrophages leads to trogocytosis and selective IL-6 secretion.
abstract: Obesity leads to adipose tissue inflammation that is characterized by increased release of proinflammatory molecules and the recruitment of activated immune cells. Although macrophages are present in the highest number among the immune cells in obese adipose tissue, not much is known about their direct interaction with adipocytes. We have introduced an ex vivo experimental system to characterize the cellular interactions and the profile of secreted cytokines in cocultures of macrophages and human adipocytes differentiated from either mesenchymal stem cells or a preadipocyte cell line. As observed by time-lapse microscopy, flow, and laser-scanning cytometry, macrophages phagocytosed bites of adipocytes (trogocytosis), which led to their de novo, phagocytosis and NF-κB-dependent synthesis, then release of interleukin (IL)-6 and monocyte chemoattractant protein (MCP)-1. IL-6 secretion was not accompanied by secretion of other proinflammatory cytokines, such as tumor necrosis factor (TNF)-α and IL-8, except MCP-1. LPS-induced release of TNF-α, IL-8 and MCP-1 was decreased in the presence of the differentiated adipocytes but the IL-6 level did not subside suggesting that phagocytosis-dependent IL-6 secretion may have significant regulatory function in the inflamed adipose tissue.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary.
authors.forename: A K
authors.initials: AK
authors.lastname: Sárvári
authors.affiliation: Department of Biophysics and Cell Biology, University of Debrecen, Debrecen, Hungary.
authors.forename: Q-M
authors.initials: QM
authors.lastname: Doan-Xuan
authors.affiliation: Department of Biophysics and Cell Biology, University of Debrecen, Debrecen, Hungary.
authors.forename: Z
authors.initials: Z
authors.lastname: Bacsó
authors.affiliation: Department of Biophysics and Cell Biology, University of Debrecen, Debrecen, Hungary.
authors.forename: I
authors.initials: I
authors.lastname: Csomós
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary.
authors.forename: Z
authors.initials: Z
authors.lastname: Balajthy
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary.
authors.forename: L
authors.initials: L
authors.lastname: Fésüs
mesh_terms: D017667:Adipocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D020126:Brefeldin A / Q000494:pharmacology; D002450:Cell Communication / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D018920:Coculture Techniques; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects
chemical_list: D018836:Inflammation Mediators; D015850:Interleukin-6; D008070:Lipopolysaccharides; D016328:NF-kappa B; D020126:Brefeldin A