Role of the IL-33/ST2 Activation Pathway in the Development of the Hepatic Fibrosis Induced by Schistosoma mansoni Granulomas in Mice.

Schistosoma mansoni eggs retained in host tissues induce innate cytokine release, contributing to the induction of Type-2 immune responses and granuloma formation, important to restrain cytotoxic antigens, but leading to fibrosis. Interleukin(IL)-33 participates in experimental models of inflammation and chemically induced fibrosis, but its role in S. mansoni-induced fibrosis is still unknown. To explore the role of the IL-33/suppressor of the tumorigenicity 2 (ST2) pathway, serum and liver cytokine levels, liver histopathology, and collagen deposition were comparatively evaluated in S. mansoni-infected wild-type (WT) and IL-33-receptor knockout (ST2-/-) BALB/c mice. Our data show similar egg counts and hydroxyproline in the livers of infected WT and ST2-/- mice; however, the extracellular matrix in ST2-/- granulomas was loose and disorganised. Pro-fibrotic cytokines, such as IL-13 and IL-17, and the tissue-repairing IL-22 were significantly lower in ST2-/- mice, especially in chronic schistosomiasis. ST2-/- mice also showed decreased α-smooth muscle actin (α-SMA) expression in granuloma cells, in addition to reduced Col III and Col VI mRNA levels and reticular fibres. Therefore, IL-33/ST2 signalling is essential for tissue repairing and myofibroblast activation during S. mansoni infection. Its disruption results in inappropriate granuloma organisation, partly due to the reduced type III and VI collagen and reticular fibre formation.

GANT61 Reduces Hedgehog Molecule (GLI1) Expression and Promotes Apoptosis in Metastatic Oral Squamous Cell Carcinoma Cells.

Due to its importance in the pathogenesis of oral squamous cell carcinoma (OSCC), the Hedgehog (HH) pathway is considered a potential therapeutic target. We investigated the effects of GANT61, a GLI inhibitor, on HH gene expression, as well as on metastatic OSCC cell proliferation and death. Following culture in DMEM medium, cytotoxicity of GANT61 against different tumor and non-tumor cell types was assessed by alamarBlue assays. Cytotoxicity analysis revealed that the metastatic HSC3 cell line was the most sensitive (IC50: 36 µM) to the tested compound. The compound's effects on the expression of HH pathways components were analyzed by qPCR and Western blot; cell viability was analyzed by trypan blue assay and flow cytometry were used to investigate cell cycle phase, morphology, and death patterns in HSC3 cells. A significant reduction in mRNA levels of the GLI1 transcription factor was found after 12 h of treatment withGANT61. Protein expression levels of other HH pathway components (PTCH1, SHH, and Gli1) and HSC3 cell viability also decreased after 24 h of treatment. Cell cycle analysis and death pattern evaluations revealed significantly increased nuclear fragmentation in sub-G1 phase, as well as cell death due to apoptosis. In conclusion, the significantly reduced GLI1 gene expression seen in response to the GLI inhibitor indicates diminished downstream activation in HH pathway components. GANT61 significantly reduced cell viability in the metastatic cell line of OSCC and promoted a significant increase in nuclear fragmentation and cell death by apoptosis.

Anti-IL-13Rα2 therapy promotes recovery in a murine model of inflammatory bowel disease.

There continues to be a major need for more effective inflammatory bowel disease (IBD) therapies. IL-13Rα2 is a decoy receptor that binds the cytokine IL-13 with high affinity and diminishes its STAT6-mediated effector functions. Previously, we found that IL-13Rα2 was necessary for IBD in mice deficient in the anti-inflammatory cytokine IL-10. Here, we tested for the first time a therapeutic antibody specifically targeting IL-13Rα2. We also used the antibody and Il13ra2-/- mice to dissect the role of IL-13Rα2 in IBD pathogenesis and recovery. Il13ra2-/- mice were modestly protected from induction of dextran sodium sulfate (DSS)-induced colitis. Following a 7-day recovery period, Il13ra2-/- mice or wild-type mice administered the IL-13Rα2-neutralizing antibody had significantly improved colon health compared to control mice. Neutralizing IL-13Rα2 to increase IL-13 bioavailability promoted resolution of IBD even if neutralization occurred only during recovery. To link our observations in mice to a large human cohort, we conducted a phenome-wide association study of a more active variant of IL-13 (R130Q) that has reduced affinity for IL-13Rα2. Human subjects carrying R130Q reported a lower risk for Crohn's disease. Our findings endorse moving anti-IL-13Rα2 into preclinical drug development with the goal of accelerating recovery and maintaining remission in Crohn's disease patients.

Hepatocellular carcinoma and liver cirrhosis TP53 mutation analysis reflects a moderate dietary exposure to aflatoxins in Espírito Santo State, Brazil.

The close relationship between aflatoxins and 249ser TP53 gene mutation (AGG to AGT, Arg to Ser) in hepatocellular carcinoma (HCC) makes this mutation an indirect indicator of dietary contamination with this toxin. We have examined the prevalence of codon 249 TP53 mutation in 41 HCC and 74 liver cirrhosis (without HCC) cases diagnosed at the HUCAM University Hospital in Vitoria, Espírito Santo State, Brazil. DNA was extracted from paraffin sections and from plasma. The mutation was detected by DNA amplification, followed by restriction endonuclease digestion and confirmed by direct sequencing. DNA restriction showed 249ser mutation in 16 HCC and 13 liver cirrhosis, but sequencing confirmed mutations in only 6 HCC and 1 liver cirrhosis. In addition, sequencing revealed 4 patients with mutations at codon 250 (250ser and 250leu) in HCC cases. The prevalence of TP53 mutation was 10/41 (24.3%) in HCC and 1/74 (1.4%) in liver cirrhosis. No relationship between the presence of mutations and the etiology of HCC was observed. TP53 exon 7 mutations, which are related to aflatoxins exposure, were found at 14.6% (249ser), 7.3% (250leu) and 2.4% (250ser) in 41 cases of HCC and 1.4% in 74 liver cirrhosis (without HCC) cases, suggesting a moderate dietary exposure to aflatoxins in the Espírito Santo State, Brazil.