Tumor Necrosis Factor (TNF) Receptor Expression Determines Keratinocyte Fate upon Stimulation with TNF-Like Weak Inducer of Apoptosis

Figure 6

The effect of TWEAK/Fn14 interaction on cytoplasmic import of cIAP1 in TNFR2-overexpressing keratinocytes. Primary human keratinocytes were cultured in vitro. TNFR2-overexpressing keratinocytes were constructed using a retroviral vector. Some cells were pretransfected with siRNA against Fn14 or a control target and then received 48 h stimulation with TWEAK (100 ng/ml). (a) The distribution of cIAP1 was analyzed in cells via immunofluorescent staining. (b) The expression of cIAP1 or RIP1 protein was determined in cell lysates or cytoplasmic (or nuclear) fraction via Western blot. In the bottom of this panel, ubiquitinated RIP1 was detected by immunoprecipitation with anti-RIP1 IgG and then antiubiquitin IgG. (c, d) The band intensities of cIAP1 and RIP1 were measured with ImageJ. Data were obtained from five independent experiments. Representative images are shown. . ns: not significant.

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