Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0239946 (liver fibrosis)
 8,268 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Liver lymphocytes are enriched in natural killer (NK) cells, which are involved in innate immune defenses against viral infection and tumor transformation in the liver. Recent evidence indicates that NK cell activation by IFN-alpha, IFN-gamma or dsRNA attenuates liver fibrosis through the direct killing of activated hepatic stellate cells (HSCs). Interestingly, NK cells do not kill quiescent or fully activated HSCs, but only early-activated HSCs, as only these cells express elevated levels of the NK cell-activating ligand retinoic acid-induced early transcript (RAE)-1 and TNF-related apoptosis-inducing ligand receptors, in addition to downregulated levels of the NK-cell inhibitory ligand, MHC-I. Inhibition of liver fibrosis by NK cells can also be achieved through production of IFN-gamma, which induces HSC cell cycle arrest and apoptosis in a STAT1-dependent manner. Clinically, it has also been observed that NK cell activity is negatively correlated with liver fibrosis in patients with chronic hepatitis C infection. Therefore, since NK cells inhibit liver fibrosis, stimulating NK activity could potentially be a novel strategy to treat liver fibrosis. Clinical studies will be required to confirm whether stimulating NK cell activity is effective and safe in treating human liver fibrosis.
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PMID:Activation of natural killer cells inhibits liver fibrosis: a novel strategy to treat liver fibrosis. 1907 44

Thymic stromal lymphopoietin was recently identified as a master switch for the development of allergen-driven Th2 responses. However, the role of thymic stromal lymphopoietin (TSLP) in the development of helminth-induced Th2 responses is unclear. Here, using TSLPR(-/-) mice, we show that while TSLPR signaling participates in the development of Schistosoma mansoni egg-induced CD4(+) Th2 responses, it plays only a transient role in the development of Th2-dependent pathology in the lung, liver, and intestine. Studies conducted in a pulmonary granuloma model showed that while a reduction in IL-4/IL-13-dependent granulomatous inflammation and tissue eosinophilia was observed in TSLPR(-/-) mice undergoing a primary response, lesion formation was not affected during a secondary granulomatous response, even though IL-5 and IL-13 were modestly reduced in the knockout mice. To evaluate the importance of TSLPR signaling in the development of a chronic Th2-dependent response, TSLPR(-/-) mice were also infected with S. mansoni cercariae. Here, the only significant difference noted in TSLPR(-/-) mice was a modest decrease in liver fibrosis in acutely infected animals. The transient decrease in fibrosis was associated with increased production of the antifibrotic cytokine IFN-gamma and decreased production of the profibrotic cytokine IL-13. Although the altered cytokine response persisted in chronically infected TSLPR(-/-) mice, it failed to reduce granuloma formation or fibrosis, confirming that TSLPR signaling plays a limited role in the development of chronic Th2-dependent pathology. Collectively, these findings suggest that while TSLPR signaling serves a key role in allergen-driven Th2 responses, it exerts minor regulatory activity during this chronic helminth infection.
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PMID:Regulation of helminth-induced Th2 responses by thymic stromal lymphopoietin. 1941 99

A pivotal role of phosphoinositide 3-kinase-gamma (PI3Kgamma) in inflammatory cell activation and recruitment makes it an attractive target for immunomodulatory therapy. In present study we investigated the therapeutic efficiency of AS605240, a selective PI3Kgamma inhibitor, on hepatitis and liver fibrosis in murine models induced by concanavalin A (ConA). Orally administration of AS605240 significantly improved survival, decreased the serum levels of alanine aminotransaminase (ALT), prevented inflammatory infiltration to liver in ConA-induced hepatitis. TNF-alpha and IFN-gamma at protein levels in serum and mRNA levels in liver were markedly reduced. Downregulated phospho-Akt level of inflammatory cells infiltrating the liver by AS605240 treatment was detected by immunohistochemistry analysis in liver and further confirmed by Western blotting analysis in splenocytes. In ConA-induced chronic liver fibrosis model, accumulation of smooth-muscle actin (SMA)-expressing cells was partially inhibited by AS605240 treatment. These observations suggest that AS605240 might be of therapeutic value for the treatment of ConA-induced hepatic injury.
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PMID:Phosphoinositide 3-kinase gamma inhibitor ameliorates concanavalin A-induced hepatic injury in mice. 1953 42

Hepatic lymphocytes are enriched in NK and NKT cells that play important roles in antiviral and antitumor defenses and in the pathogenesis of chronic liver disease. In this review, we discuss the differential distribution of NK and NKT cells in mouse, rat, and human livers, the ultrastructural similarities and differences between liver NK and NKT cells, and the regulation of liver NK and NKT cells in a variety of murine liver injury models. We also summarize recent findings about the role of NK and NKT cells in liver injury, fibrosis, and repair. In general, NK and NKT cells accelerate liver injury by producing proinflammatory cytokines and killing hepatocytes. NK cells inhibit liver fibrosis via killing early-activated and senescent-activated stellate cells and producing IFN-gamma. In regulating liver fibrosis, NKT cells appear to be less important than NK cells as a result of hepatic NKT cell tolerance. NK cells inhibit liver regeneration by producing IFN-gamma and killing hepatocytes; however, the role of NK cells on the proliferation of liver progenitor cells and the role of NKT cells in liver regeneration have been controversial. The emerging roles of NK/NKT cells in chronic human liver disease will also be discussed.Understanding the role of NK and NKT cells in the pathogenesis of chronic liver disease may help us design better therapies to treat patients with this disease.
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PMID:Liver natural killer and natural killer T cells: immunobiology and emerging roles in liver diseases. 1954 50

Hepatitis, a common human disease, may be followed by severe liver injury, eventually leading to fatty liver, liver fibrosis and hepatocellular carcinoma. CD8 T cells are a double-edged sword in the response to infection with the hepatitis virus. On one hand, rapid activation of CD8 T cells is critically important for the elimination of the virus. On the other hand, in persistent viral infection, the activation of CD8 T cells substantially contributes to liver injury. The clinical course of hepatitis, thus, critically depends on mechanisms regulating the activity of CD8 T cells. In observations in human hepatitis and in mice infected with the lymphocytic choriomeningitis virus, the clinical course of hepatitis is modified by several immunological factors including neutralizing antibodies: RIG-I, TLRs, MyD88, interferon type I, TNF-alpha, MHC I, Tap, TCR, CD8, IL-2, IL-7, PD-1, IFN-I, IL-10, IFN-gamma, perforins, serotonin and iNOS (table 1) . Additional experimental effort is needed to understand the concerted interplay of those molecules in viral hepatitis of man and mice.
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PMID:Host mechanisms in viral hepatitis. 2046 Aug 87


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