Monokine stimulation of interleukin-11 production by human vascular smooth muscle cells in vitro Original Research Article

Human vascular smooth muscle cells (VSMC) are a component of blood vessels, and secrete a variety of cytokines in atherosclerotic loci. Interleukin-11 (IL-11), a member of IL-6-like cytokines, is reported to be involved in inflammation and tissue remodeling, both of which are observed in atherosclerosis. However, no information is available as to the production of IL-11 by VSMC. Therefore, the expression of IL-11 in VSMC is investigated. The amounts of IL-11 protein and mRNA were determined by enzyme-linked immunosorbent assay (ELISA) and Northern blot analysis, respectively. The expression of IL-11 in VSMC was also immunohistochemically determined. IL-1α, transforming growth factor-β (TGFβ) and, to a lesser extent, tumor necrosis factor-α (TNFα) stimulated the IL-11 production by VSMC, and the stimulatory effects of IL-1α and TGFβ on IL-11 production were dose-dependent. IL-1α and TNFα synergistically augmented TGFβ-stimulated IL-11 production by VSMC. Immunohistochemical staining also revealed the expression of IL-11 protein in VSMC. Furthermore, IL-1α, TGFβ, and TNFα induced IL-11 gene expression in VSMC. Because IL-6-like cytokines are reported to be cytoprotective, monokine-stimulated IL-11 may have a potent protective role in atherosclerotic lesions.