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. 2011 Apr;178(4):1591–1604. doi: 10.1016/j.ajpath.2010.12.020

Figure 4.

Figure 4

The PTP1B decreased TNF-induced JNK phosphorylation in human and mouse hepatocytes. A: The HuH-7 human liver cells were transfected with PTP1B or scramble (scr) siRNA oligos for 48 hours before TNF-α or IL-6 stimulation. The phosphorylation of JNK (pJNK) and STAT3 (pSTAT3) was analyzed with the indicated antibodies. A representative Western blot is shown. Autoradiograms corresponding to three independent experiments were quantified by scanning densitometry. Results show arbitrary units of JNK and STAT3 phosphorylation, and average PTP1B levels in scr or PTP1B siRNA-transfected cells are expressed as the mean ± SEM. *P < 0.05 for HuH-7 cells transfected with the PTP1B siRNA versus cells transfected with scr siRNA. B: Immortalized PTP1B−/− hepatocytes were stimulated with 10-ng/mL TNF-α or IL-6 for 10 and 30 minutes, respectively; 60 μL of cell lysates (1 μg/μL) was incubated with 10 U of recombinant PTP1B for 30 minutes at 37°C, and pJNK and pSTAT3 were analyzed by Western blot. As a loading control, membranes were blotted with total JNK or STAT3 antibodies. A representative Western blot is shown. Autoradiograms corresponding to three independent experiments were quantified by scanning densitometry. Results are expressed as arbitrary units of JNK and STAT3 phosphorylation and are the mean ± SEM. *P < 0.05 for PTP1B−/− hepatocytes reconstituted with active PTP1B versus nonreconstituted cells.