For information on in vivo transfer of MDSCs in D-Gal/LPS-treated mice, please see the Supporting Materials. Differences between groups were compared using the Student t test or Mann Whitney’s U test. Initially, we measured IL-25 in proteins extracted from various organs of healthy BALB/c mice by ELISA. IL-25 was detectable in extracts from liver, kidney, intestine, spleen, and lung, but the highest concentrations of the PD98059 research buy cytokine were noted in liver and kidney (Fig. 1A). Western blotting analysis of total liver extracts showed that content of IL-25 was more pronounced in the parenchymal

fraction in comparison to the nonparenchymal fraction (Fig. 1B). To exclude the possibility that the high IL-25 noted in the hepatocyte fraction was the result of contaminating leukocytes, albumin (ALB) and CD3 RNA transcripts were evaluated in both hepatocytes and mononuclear cell fractions by real-time PCR. ALB was detected only in hepatocyte-enriched preparations, whereas CD3 RNA expression was markedly higher in mononuclear cells (Supporting Fig. 1A,B). Further analysis of IL-25 expression in hepatocyte-enriched

Gefitinib concentration fractions by FCM revealed that the cytokine was mostly produced by CD45-negative cells (Fig. 1C), thus confirming that hepatocytes were the major source of IL-25 in this cell preparation. Moreover, comparison of IL-25 expression in hepatocyte-enriched and mononuclear cell preparations confirmed that IL-25 is mostly produced by hepatocytes and that few CD3-positive cells expressed IL-25 (Fig. 1 C-D). To further prove that IL-25 is constitutively produced by murine hepatocytes, we measured IL-25 in supernatants of AML12 cells, a normal murine hepatocyte line, cultured in the presence or absence of transforming growth factor beta (TGF-β)1, a cytokine that positively regulates IL-25 production

in other systems.[18] AML12 spontaneously secreted IL-25 and responded to TGF-β1 with enhanced IL-25 production (Fig. 1E). To evaluate whether induction of acute liver damage changes expression of IL-25, mice were injected IP with D-Gal/LPS, because this experimental model of acute liver damage shows biochemical and immunological changes in Protein tyrosine phosphatase the liver similar to those observed in human FH.[19] Mice given D-Gal/LPS exhibited a time-dependent reduction of IL-25 levels in the liver, compared to PBS-treated (control) mice (Fig. 1F), whereas D-Gal/LPS-induced liver damage was associated with no significant change in IL-6 production (not shown). Consistently, RNA transcripts for Fizz, a molecule positively regulated by IL-25,[12] was reduced in livers of D-Gal/LPS-treated mice (Supporting Fig. 2A). In contrast, RNA expression of hepatocyte-derived alpha-fetoprotein (AFP) remained unchanged (Supporting Fig. 2B), suggesting that the decline in IL-25 production in D-Gal/LPS-injected mice was not simply the result of necrosis of hepatocytes.