Figure 4.
Expression and activation of the NLRP3 inflammasome occur in both colonic macrophages and colonic epithelial cells. [A] Expression and activation of adaptor protein ASC in purified colonic epithelial cells [CECs]. CECs isolated from wild-type [WT] and IL-10-/- mice were analysed by sodium dodecyl sulfate polyacrylamide gel electrophoresis [SDS-PAGE] and western blotted for ASC, casapse-1 pro-enzyme form [casp-1/p48], and activated form of caspase-1 [casp-1/p20]. [B] Immunofluorescent staining for NLRP3 and ASC using consecutive sections of proximal colon from IL-10-/- mice [B-a, b]. [B-b] an enlarged area [top left quarter] of the image in panel [B-a]. Positive staining of NLRP3 and ASC is shown in green; nuclei are stained with Hoescht [blue]. ASC- and NLRP3-positive cells are both epithelial cells and cells in the lamina propria [indicated by yellow arrows; B-b]. Luminal surface expression of ASC or NLRP3 often appears punctate [red arrows]. [C] Comparison of NLRP3 and ASC expressions in colonic macrophages and CECs in IL-10-/- mice. Representatives of at least three independent experiments are shown.