IL-6, TNF-α and LPS increased <i>SAA1</i> expression and protein content in human skeletal muscle cells <i>in vitro</i>.

<p>(A) Differentiated human skeletal myotubes were treated with human recombinant IL-6 (100 ng/ml), TNF-α (10 ng/ml), or a combination of both (IL-6, 100 ng/ml; TNF-α, 10 ng/ml) for 16 h. RT-PCR was used to measure <i>SAA1</i> expression, which was normalized to <i>beta-2-microglobulin</i> expression. Relative gene expression by fold-induction of <i>SAA1</i> expression (above column) is shown. **<i>P</i><0.01, *<i>P</i><0.05. (B) Immunocytochemistry of SAA1 (green) on differentiated human myotubes following treatment with human recombinant IL-6 (100 ng/ml), human recombinant TNF-α (10 ng/ml), and both cytokines (IL-6, 100 ng/ml; TNF-α, 10 ng/ml) together for 16 h is shown. Nuclei were stained with 4′,6-diamidino-2-phenylindole (DAPI; blue); scale bar 50 μm. (C) Human skeletal myotubes were treated with lipopolysaccharide (LPS, 1 μg/ml) for 16 h. RT-PCR was used to measure <i>SAA1</i> expression, which was normalized to <i>Glyceraldehyde-3 phosphate dehydrogenase</i> (<i>GAPDH</i>); *<i>P</i><0.05. (D) Immunocytochemistry of SAA1 (green) on human myotubes following LPS treatment (1 μg/ml) for 16 h. Nuclei were stained with DAPI (blue); scale bar 50 μm.