title: TNF-alpha-induced self expression in human lung endothelial cells is inhibited by native and oxidized alpha1-antitrypsin.
abstract: Endothelial cells are among the main physiological targets of the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha). In endothelial cells TNF-alpha elicits a broad spectrum of biological effects including differentiation, proliferation and apoptosis. alpha1-antitrypsin (AAT), an endogenous inhibitor of serine proteases plays a vital role in protecting host tissue from proteolytic injury at sites of inflammation. Recently, it has been shown that AAT can be internalized by pulmonary endothelial cells, raising speculation that it may modulate endothelial cell function in addition to suppressing protease activity. Using Affymetrix microarray technology, real time PCR and ELISA methods we have investigated the effects of AAT on un-stimulated and TNF-alpha stimulated human primary lung microvascular endothelial cell gene expression and protein secretion. We find that AAT and TNF-alpha generally induced expression of distinct gene families with AAT exhibiting little activity in terms of inflammatory gene expression. Approximately 25% of genes up regulated by TNF-alpha were inhibited by co-administration of AAT including TNF-alpha-induced self expression. Surprisingly, the effects of AAT on TNF-alpha-induced self expression was inhibited equally well by oxidized AAT, a modified form of AAT, which lacks serine protease inhibitor activity. Overall, the pattern of gene expression regulated by native and oxidized AAT was similar with neither inducing pro-inflammatory gene expression. These findings suggest that inhibitory effects of native and oxidized forms of AAT on TNF-alpha stimulated gene expression may play an important role in limiting the uncontrolled endothelial cell activation and vascular injury in inflammatory disease.
authors.affiliation: Department of Clinical Sciences, University Hospital Malmö, Lund University, S-20502 Malmö, Sweden.
authors.forename: Devipriya
authors.initials: D
authors.lastname: Subramaniyam
authors.forename: Robert
authors.initials: R
authors.lastname: Virtala
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Pawłowski
authors.forename: Ib Groth
authors.initials: IG
authors.lastname: Clausen
authors.forename: S
authors.initials: S
authors.lastname: Warkentin
authors.forename: Tim
authors.initials: T
authors.lastname: Stevens
authors.forename: Sabina
authors.initials: S
authors.lastname: Janciauskiene
mesh_terms: D002478:Cells, Cultured; D004338:Drug Combinations; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism*; D025461:Feedback, Physiological / Q000187:drug effects; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010084:Oxidation-Reduction; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics* / Q000494:pharmacology*; D000515:alpha 1-Antitrypsin / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D004338:Drug Combinations; D014409:Tumor Necrosis Factor-alpha; D000515:alpha 1-Antitrypsin