Michihide Nishihara, Hiroki Aoki, Satoko Ohno, Aya Furusho, Saki Hirakata, Norifumi Nishida, Sohei Ito, Makiko Hayashi, Tsutomu Imaizumi, Yoshihiro Fukumoto
PloS one 2017Although the pathogenesis of abdominal aortic aneurysm (AAA) remains unclear, evidence is accumulating to support a central role for inflammation. Inflammatory responses are coordinated by various soluble cytokines of which IL-6 is one of the major proinflammatory cytokines. In this study we examined the role of IL-6 in the pathogenesis of experimental AAA induced by a periaortic exposure to CaCl2 in mice. We now report that the administration of MR16-1, a neutralizing monoclonal antibody specific for the mouse IL-6 receptor, mildly suppressed the development of AAA. The inhibition of IL-6 signaling provoked by MR16-1 also resulted in a suppression of Stat3 activity. Conversely, no significant changes in either NFκB activity, Jnk activity or the expression of matrix metalloproteinases (Mmp) -2 and -9 were identified. Transcriptome analyses revealed that MR16-1-sensitive genes encode chemokines and their receptors, as well as factors that regulate vascular permeability and cell migration. Imaging cytometric analyses then consistently demonstrated reduced cellular infiltration for MR16-1-treated AAA. These results suggest that IL-6 plays an important but limited role in AAA pathogenesis, and primarily regulates cell migration and infiltration. These data would also suggest that IL-6 activity may play an important role in scenarios of continuous cellular infiltration, possibly including human AAA.
Michihide Nishihara, Hiroki Aoki, Satoko Ohno, Aya Furusho, Saki Hirakata, Norifumi Nishida, Sohei Ito, Makiko Hayashi, Tsutomu Imaizumi, Yoshihiro Fukumoto. The role of IL-6 in pathogenesis of abdominal aortic aneurysm in mice. PloS one. 2017;12(10):e0185923
PMID: 28982132
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