Fig 1: Exogenous IL-33 activates ERK and NF-κB p65 subunit in mouse pancreas.In mice (without duct ligation) injected with 2.5 µg recombinant IL-33 protein i.p. twice daily for 48 hrs, immunoblots of pancreatic homogenates showed activation of ERK and the p65 NF-κB subunit as evidenced by increased phosphorylation of ERK and p65, compared to phosphate buffered saline (PBS) injected controls, while p38 and JNK did not show evidence of activation. Densitometric ratios of phosphorylated to total protein expression were normalized to PBS controls and are graphed on the right (mean ± SEM of the two samples in each group is shown).
Fig 2: IL-33 activates ERK in the human exocrine pancreas.Human normal pancreas fragments were incubated in culture medium and stimulated with 100 ng/ml IL-33 for 6 hrs. The fragments were then processed for immunoblotting using specific antibodies to pERK, then stripped and reprobed for ERK and β-actin expression. Densitometric ratios of pERK to ERK expression were normalized to unstimulated controls (mean ± SEM of the two samples in each group is shown). IL-33 activated ERK in human pancreatic tissue as evidenced by a nearly two-fold increase in pERK expression.
Fig 3: TNF-α stimulates IL-33 release from acinar cells, involving the ERK MAP kinase pathway.A) Isolated mouse acinar cells stimulated with TNF-α (10 ng/ml) for 6 hrs showed increased IL-33 release into the medium. B) Isolated mouse acinar cells were infected with 5 MOI of Ad.GFP or Ad.DN.ERK for 48 hrs and then stimulated with TNF-α (10 ng/ml) for 6 hrs before collecting medium for ELISA analysis. IL-33 levels in the medium were normalized to total protein in cells. Data are mean ± SEM; n = 3 wells/group; ANOVA, asterisk (*) indicates significance compared to unstimulated control, p<0.05.
Fig 4: Exogenous IL-33 induces acute inflammation in the pancreas but not the jejunum.Phosphate buffered saline (PBS) injected control mice lacked pancreatic or jejunal inflammatory changes. In mice (without duct ligation) injected with 2.5 µg recombinant IL-33 protein i.p. twice daily for 48 hrs, histological examination of pancreas tissue showed multifocal expansion of perilobular areas with perivascular edema, neutrophils and some macrophages, with the consistent finding of margination and perivascular neutrophil infiltration (red arrow). Jejunum of IL-33 injected mice showed increased goblet cell density but no evidence of perivascular neutrophil infiltration (black arrows) or acute inflammation. Hematoxylin and eosin stain; original magnification X400.
Fig 5: Acinar cells from mice receiving exogenous IL-33 show increased cytokine release.In mice (without duct ligation) injected with 2.5 µM recombinant IL-33 protein i.p. twice daily for 48 hrs followed by acinar cell isolation and incubation in culture medium for 6 hrs, IL-6 release and CXCL2/MIP-2α release were significantly increased compared to PBS injected controls. Both IL-6 and CXCL2/MIP-2α levels were normalized to total protein in cells. Data are mean ± SEM; n = 6 wells/group; Student's t-test; asterisk (*) indicates significance compared to PBS injected control, p<0.05.
Supplier Page from Enzo Life Sciences, Inc. for IL-33 (mouse), (recombinant)