Unlabelled: Incidence and prevalence of inflammatory liver diseases has increased over the last years, but therapeutic options are limited. Pregnancy induces a state of immune tolerance, which can result in spontaneous improvement of clinical symptoms of certain autoimmune diseases including autoimmune hepatitis (AIH). We investigated the immune-suppressive mechanisms of the human pregnancy hormone, chorionic gonadotropin (hCG), in the liver. hCG signaling activates silent mating type information regulation 2 homolog 1 (SIRT1), which deacetylates forkhead box o3 (FOXO3a), leading to repression of proapoptotic gene expression, because the immunosuppressive consequence attributed to the absence of caspase-3 activity of hepatocellular interleukin 16 (IL-16) is no longer processed and released. Thus, serum levels of IL-16, a key chemotactic factor for CD4 lymphocytes, were reduced and migration to injured hepatocytes prevented. Furthermore, elevated IL-16 levels are found in the sera from patients with AIH, hepatitis B virus, hepatitis C virus, and nonalcoholic steatohepatitis.
Conclusion: Here, we report that hCG regulates the SIRT1/FOXO3a axis in hepatocytes, resulting in immune suppression by attenuating caspase-3-dependent IL-16 processing and release, which concomitantly prevents autoaggressive T-cell infiltration of the liver. Considering the low toxicity profile of hCG in humans, interrupting the inflammatory cycle by hCG opens new perspectives for therapeutic intervention of inflammatory liver diseases. (Hepatology 2017;65:2074-2089).
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Biol Open
December 2024
Institut Curie, Université PSL, CNRS UMR3348, 91400 Orsay, France.
The SUMO-targeted ubiquitin ligase (STUbL) family is involved in multiple cellular processes via a wide range of mechanisms to maintain genome stability. One of the evolutionarily conserved functions of STUbL is to promote changes in the nuclear positioning of DNA lesions, targeting them to the nuclear periphery. In Schizossacharomyces pombe, the STUbL Slx8 is a regulator of SUMOylated proteins and promotes replication stress tolerance by counteracting the toxicity of SUMO conjugates.
View Article and Find Full Text PDFBiochem Pharmacol
December 2024
Department of Biological Sciences (Pharmacology & Toxicology), National Institute of Pharmaceutical Education and Research (NIPER) Hyderabad, Telangana 500037, India. Electronic address:
Silent mating-type information regulation 2 homology 3 (SIRT3) is a member of the sirtuins family expressed in mitochondria performs deacetylation of metabolic enzymes and promotes longevity. 7-hydroxy-3-(4'-methoxyphenyl) coumarin (C12) is a small molecule first ever known for its direct activation of SIRT3. SIRT3 performs its function by balancing the redox system by activating manganese superoxide dismutase (MnSOD) and 8-Oxoguanine glycosylase (OGG1).
View Article and Find Full Text PDFWorld J Cardiol
November 2024
National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20810, United States.
Nucleic Acids Res
December 2024
Institute for Genetics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 17, 35392 Giessen, Germany.
Heterochromatin plays a critical role in regulating gene expression and maintaining genome integrity. While structural and enzymatic components have been linked to heterochromatin establishment, a comprehensive view of the underlying pathways at diverse heterochromatin domains remains elusive. Here, we developed a systematic approach to identify factors involved in heterochromatin silencing at pericentromeres, subtelomeres and the silent mating type locus in Schizosaccharomyces pombe.
View Article and Find Full Text PDFJ Cell Sci
December 2024
Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G2W1, Canada.
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