Chlamydia pneumoniae infection promotes a proliferative phenotype in the vasculature through Egr-1 activation in vitro and in vivo

Jan Rupp, Thomas Hellwig-Burgel, Viola Wobbe, Ulrike Seitzer, Ernst Brandt, M. Maass

38 Zitate (Scopus)


Atherosclerosis is characterized by inflammation and proliferation of vascular cells. The intracellular bacterium Chlamydia (Chlamydophila) pneumoniae uses blood monocytes [peripheral blood mononuclear cells (PBMCs)] for dissemination, has been found to persist in atherosclerotic lesions, and has been implicated in atherogenesis by small GTPase activation and T lymphocyte recruitment. Infection of human coronary artery smooth muscle cells with C. pneumoniae significantly induced mRNA and protein for the angiogenic transcription factor Egr-1, resulting in enhanced coronary artery smooth muscle cell proliferation, which was reduced by transfection with small interfering RNA duplexes targeted at Egr-1 mRNA. These effects required viable chlamydiae and depended on p44/42 mitogen-activated protein kinase activity but not on the p38 mitogen-activated protein kinase pathway. Postinfectious Egr-1 mRNA up-regulation in arterial vessels was confirmed ex vivo in a rat aortic ring model of focal vascular chlamydial infection. An in vivo model based on the injection of C. pneumoniae-infected PBMCs into mice confirmed Egr-1 mRNA up-regulation within 24 h of endovascular infection. Arterial injury from repeated direct chlamydial infections and cell-to-cell contact with C. pneumoniae-infected PBMCs might represent a chronic focus of proliferative activity linked to the media proliferation seen in advanced atherosclerosis. Overall, chlamydial infection induces a proliferative phenotype in vascular cells via transcription factor Egr-1 activation in vitro, ex vivo, and in vivo.

ZeitschriftProceedings of the National Academy of Sciences of the United States of America
Seiten (von - bis)3447-3452
PublikationsstatusVeröffentlicht - 01.03.2005

Strategische Forschungsbereiche und Zentren

  • Forschungsschwerpunkt: Infektion und Entzündung - Zentrum für Infektions- und Entzündungsforschung Lübeck (ZIEL)


Untersuchen Sie die Forschungsthemen von „Chlamydia pneumoniae infection promotes a proliferative phenotype in the vasculature through Egr-1 activation in vitro and in vivo“. Zusammen bilden sie einen einzigartigen Fingerprint.