Fig. 4.

Activation of STAT3 and pSTAT3 by IL-22 stimulation. HSG cells (2 × 10⁵) in serum-free media were stimulated without (NS: no stimulation) or with rIL-22 at 10, 50, 100, and 500 ng. Cells lysates were obtained and separated by electrophoresis. The membranes were probed with specific primary antibodies, including anti-STAT3 and their anti-pSTAT3 (Cell Signaling, 1:1000 dilution for anti-STATs and -pSTATs) and anti-β-actin at 1:20,000 (Sigma). Membranes were probed with secondary antibody conjugated with IRDye infrared dye (1:20,000) for 1 h at RT. The signals were visualized using the Odyssey Dual-Mode Imaging System. Blots on each film were quantified by using ImageJ software (http://rsbweb.nih.gov/ij/index.htm) with relative fold difference obtained by normalizing against respective β-actin. Experiments were repeated twice for consistency. Statistical significance was determined using Mann–Whitney U test. The two-tailed p value < 0.05 was considered significant. *p < 0.05, **p < 0.01, and ***p < 0.001.