FIG. 3.

Proinflammatory IL-33 involvement in the OA mouse model. (A) Immunohistochemical localization of pWPT-EGFP- and pWPT-sST2-EGFP-transduced hASCs overexpressing EGFP or both murine sST2-FLAG and EGFP, respectively, in the OA model. Representative lung section images of AP-challenged, hASC-treated mice (AP/AP–hASC) (upper panels), and AP-challenged, hASC-sST2-treated mice (AP/AP–hASC-sST2) (lower panels) day 16 after the initial AP sensitization step. Arrows indicate the brown label detection of sST2-FLAG-overexpressing hASCs (lower left panel), and of EGFP-overexpressing hASCs (right panels). Scale bar=10 μm. (B) Serum IL-33 dynamics in the OA mouse model. Serum IL-33 levels were quantified by ELISA in both treated and nontreated mice at 16, 18, and 21 days after the initial AP sensitization step. Experimental groups are DMSO/SAL–PBS, DMSO/AP–PBS, AP/AP–PBS, AP/AP–hASC, and AP/AP–hASC-sST2. Values are means±SDs (n=4–7 mice per group). *P<0.05, AP/AP–PBS group compared with both DMSO/SAL–PBS and AP/AP–hASC-sST2 groups; ^#P<0.05, AP/AP–hASC group compared with both DMSO/SAL–PBS and AP/AP–hASC-sST2 groups. SAL, saline; PBS, phosphate-buffered saline; AP, ammonium persulfate; hASC, hASCs overexpressing EGFP; hASC-sST2, hASCs overexpressing sST2 and EGFP. Color images available online at www.liebertpub.com/scd