α1-Antitrypsin Combines with Plasma Fatty Acids and Induces Angiopoietin-like Protein 4 Expression
| Autor: | Ralf Lichtinghagen, Britta Brügger, Sabina Janciauskiene, Nupur Aggarwal, Tobias Welte, Eileen Frenzel, Stephan Immenschuh, Ravi Mahadeva, Sabine Wrenger, Sandeep Salipalli, Charles A. Dinarello, A. Mario Q. Marcondes |
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| Rok vydání: | 2015 |
| Předmět: |
Male
Linoleic acid CD36 Immunology lnfectious Diseases and Global Health Radboud Institute for Molecular Life Sciences [Radboudumc 4] Peroxisome proliferator-activated receptor Biology Fatty Acid-Binding Proteins Fatty acid-binding protein Monocytes Article Linoleic Acid chemistry.chemical_compound Western blot ANGPTL4 medicine Immunology and Allergy Angiopoietin-Like Protein 4 Humans Receptor chemistry.chemical_classification medicine.diagnostic_test Peroxisome Molecular biology PPAR gamma chemistry Gene Expression Regulation alpha 1-Antitrypsin biology.protein Female Angiopoietins Oleic Acid |
| Zdroj: | Journal of Immunology, 195, 8, pp. 3605-16 Journal of Immunology, 195, 3605-16 |
| ISSN: | 1550-6606 0022-1767 |
| Popis: | α1-Antitrypsin (A1AT) purified from human plasma upregulates expression and release of angiopoietin-like protein 4 (Angptl4) in adherent human blood monocytes and in human lung microvascular endothelial cells, providing a mechanism for the broad immune-regulatory properties of A1AT independent of its antiprotease activity. In this study, we demonstrate that A1AT (Prolastin), a potent inducer of Angptl4, contains significant quantities of the fatty acids (FA) linoleic acid (C18:2) and oleic acid (C18:1). However, only trace amounts of FAs were present in preparations that failed to increase Angplt4 expression, for example, A1AT (Zemaira) or M-type A1AT purified by affinity chromatography. FA pull-down assays with Western blot analysis revealed a FA-binding ability of A1AT. In human blood-adherent monocytes, A1AT-FA conjugates upregulated expression of Angptl4 (54.9-fold, p < 0.001), FA-binding protein 4 (FABP4) (11.4-fold, p < 0.001), and, to a lesser degree, FA translocase (CD36) (3.1-fold, p < 0.001) relative to A1AT devoid of FA (A1AT-0). These latter effects of A1AT-FA were blocked by inhibitors of peroxisome proliferator-activated receptor (PPAR) β/δ (ST247) and PPARγ (GW9662). When compared with controls, cell pretreatment with ST247 diminished the effect of A1AT-LA on Angptl4 mRNA (11.6- versus 4.1-fold, p < 0.001) and FABP4 mRNA (5.4- versus 2.8-fold, p < 0.001). Similarly, preincubation of cells with GW9662 inhibited inducing effect of A1AT-LA on Angptl4 mRNA (by 2-fold, p < 0.001) and FABP4 mRNA (by 3-fold, p < 0.001). Thus, A1AT binds to FA, and it is this form of A1AT that induces Angptl4 and FABP4 expression via a PPAR-dependent pathway. These findings provide a mechanism for the unexplored area of A1AT biology independent of its antiprotease properties. |
| Databáze: | OpenAIRE |
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