ag-490 and Liver-Cirrhosis

Angiotensin II (AngII) activates via angiotensin-II-type-I receptor (AT1R) Janus-kinase-2 (JAK2)/Arhgef1 pathway and subsequently RHOA/Rho-kinase (ROCK), which induces experimental and probably human liver fibrosis. This study investigated the relationship of JAK2 to experimental and human portal hypertension.. The mRNA and protein levels of JAK2/ARHGEF1 signalling components were analysed in 49 human liver samples and correlated with clinical parameters of portal hypertension in these patients. Correspondingly, liver fibrosis (bile duct ligation (BDL), carbon tetrachloride (CCl. Hepatic transcription of JAK2/ARHGEF1 pathway components was upregulated in liver cirrhosis dependent on aetiology, severity and complications of human liver cirrhosis (Model for End-stage Liver disease (MELD) score, Child score as well as ascites, high-risk varices, spontaneous bacterial peritonitis). SM22. Hepatic JAK2/ARHGEF1/ROCK expression is associated with portal hypertension and decompensation in human cirrhosis. The deletion of Jak2 in myofibroblasts attenuated experimental fibrosis and acute inhibition of JAK2 decreased PP. Thus, JAK2 inhibitors, already in clinical use for other indications, might be a new approach to treat cirrhosis with portal hypertension.

Topics: Adult; Animals; Carbon Tetrachloride; Collagen; Enzyme Inhibitors; Female; Hepatic Stellate Cells; Humans; Hypertension, Portal; Janus Kinase 2; Ligation; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Microfilament Proteins; Middle Aged; Muscle Proteins; Myofibroblasts; Portal Pressure; Rats; Rats, Sprague-Dawley; Rho Guanine Nucleotide Exchange Factors; rho-Associated Kinases; rhoA GTP-Binding Protein; RNA, Messenger; Severity of Illness Index; Signal Transduction; Transcription, Genetic; Tyrphostins; Up-Regulation; Vascular Resistance; Young Adult

To investigate the role of TGF-beta1 and STAT3 signaling in liver fibrosis using a rat model system and to determine the therapeutic mechanism of AG490 in relation to this signaling pathway.. Rats were randomly divided into a control group and DENA-induced liver fibrosis model group, and then subdivided into AG490 treatment groups. During fibrosis development, liver tissue samples were collected at different time points (0, 4 and 8 weeks) and evaluated according to the Scheuer scoring system. Expression of STAT3, TGFbeta1, alpha-SMA, E-cadherin, MMP2 and TIMP1 was measured by PCR (mRNA) and immunohistochemistry and western blotting (protein).. Increasing degrees of inflammation and fibrosis were observed in liver tissues of DENA-treated rats throughout model establishment. The mRNA expression of TGFbeta1 and STAT3 was significantly increased in DENA-induced rats with advanced fibrosis (AF) compared to those with early fibrosis (EF) (P = 0.034 and P = 0.012 respectively). The protein expression of TGF-beta1, phospho-Smad2, alpha-SMA, E-cadherin, STAT3 and phospho-STAT3 was significantly increased in DENA-induced rats with AF compared to the unmodeled control group (P = 0.048, P = 0.003, P = 0.002, P = 0.028, P = 0.009 and P = 0.039). The protein expression of E-cadherin was lower in the DENA-induced rats with AF than in those with EF (P = 0.026). STAT3 and TGF-beta1 co-expression was detected in AF tissues. DENA-induced AG490-treated rats with AF showed substantially lower protein expression of STAT3, TGF-beta1, MMP2 and TIMP1 compared to DENA-induced untreated rats with AF (P = 0.006, P = 0.018, P = 0.010 and P = 0.005); in addition, the degrees of fibrosis and inflammation were also greatly reduced in the DENA-induced AG490-treated rats with AF compared to DENA-induced untreated rats with AF (P = 0.042 and P = 0.021). Conclusions STAT3 signal transduction may regulate the TGF-beta1 pathway and affect liver fibrosis, especially in the advanced phase. AG490 can inhibit TGFbeta1-STAT3 signaling, resulting in reversal of liver fibrosis.

Topics: Animals; Disease Models, Animal; Liver Cirrhosis; Rats; Rats, Sprague-Dawley; Signal Transduction; STAT3 Transcription Factor; Transforming Growth Factor beta1; Tyrphostins

Non-alcoholic steatohepatitis (NASH) is a major risk factor for hepatic fibrogenesis. NASH is often found in diabetic patients with hyperglycemia. Hyperglycemia induces non-enzymatic glycation of proteins, yielding advanced glycation end-products (AGEs). Effects of AGEs are mainly mediated by two categories of cytoplasmic membrane receptors. Receptor for AGEs (RAGE) is associated with increased oxidative stress and inflammation, whereas AGE receptor-1 (AGE-R1) is involved in detoxification and clearance of AGEs. Activation of hepatic stellate cells (HSC) is crucial to the development of hepatic fibrosis. We recently reported that AGEs stimulated HSC activation likely by inhibiting gene expression of AGE-R1 and inducing gene expression of RAGE in HSC, which were eliminated by the antioxidant curcumin. This study is to test our hypothesis that curcumin eliminates the effects of AGEs on the divergent regulation of the two receptors of AGEs in HSC by interrupting the AGE-caused activation of leptin signaling, leading to the inhibition of HSC activation. We observed herein that AGEs activated leptin signaling by inducing gene expression of leptin and its receptor in HSC. Like AGEs, leptin differentially regulated gene expression of RAGE and AGE-R1. Curcumin eliminated the effects of AGEs in HSC by interrupting leptin signaling and activating transcription factor NF-E2 p45-related factor 2 (Nrf2), leading to the elevation of cellular glutathione and the attenuation of oxidative stress. In conclusions, curcumin eliminated the effects of AGEs on the divergent regulation of gene expression of RAGE and AGE-R1 in HSC by interrupting the AGE-caused activation of leptin signaling, leading to the inhibition of HSC activation.

Topics: Animals; Antineoplastic Agents; Cells, Cultured; Chromones; Curcuma; Curcumin; Gene Expression Regulation; Glycation End Products, Advanced; Hepatic Stellate Cells; Leptin; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Morpholines; Plant Extracts; Rats; Rats, Sprague-Dawley; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Receptors, Leptin; Tyrphostins

In traditional Chinese medicines, Cortex Dictamni is prescribed for the treatment of a variety of inflammatory diseases such as acute rheumatoid arthritis, skin inflammation and jaundice.. This study was designed to investigate the effect of ethanol extract of Cortex Dictamni on treatment of hepatic fibrosis and its possible mechanisms.. The in vivo effect of Cortex Dictamni extract (CDE) was evaluated by measuring histological changes and collagen content in CCl(4)-indcued hepatic fibrosis mice. Viability, apoptosis and protein expression of hepatic stellate cells (HSC) were analyzed by MTT, Annexin V staining and Western blot respectively.. CDE alleviated CCl(4)-induced hepatic fibrosis in mice and showed a much stronger inhibition of cell viability in activated HSC cell line HSC-T6 than that in normal hepatocyte L02 cells. Furthermore, CDE induced apoptosis of HSC-T6 cells associated with increased expressions of cleaved PARP and cleaved caspase-3. Interestingly, CDE activated STAT1 in HSC-T6 cells and the effect of CDE on apoptosis of HSC-T6 cells could be neutralized using JAK/STAT1 signaling inhibitor AG490.. These findings suggest that CDE possesses anti-fibrosis activity with selectively induction of activated HSC apoptosis via activating STAT1, which might be a novel strategy for hepatic fibrosis therapy.

Topics: Animals; Apoptosis; Carbon Tetrachloride; Caspase 3; Cell Line; Cell Survival; Dictamnus; Drugs, Chinese Herbal; Hepatic Stellate Cells; Humans; Liver Cirrhosis; Male; Mice; Mice, Inbred ICR; Phytotherapy; Plant Bark; Plant Roots; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; STAT1 Transcription Factor; Tyrphostins

Collagen accumulation in liver fibrosis is due in part to decreased expression of matrix metalloproteinase (MMP)-1 relative to TIMP-1. LX-2 hepatic stellate cells produce increased amounts of collagen and tissue inhibitor of metalloproteinase (TIMP)-1 in response to leptin. The effect of leptin on MMP-1 production has not been reported.. LX-2 cells were treated with leptin with or without inhibitors. We determined: phosphorylation of Janus kinase (JAK) 1 and -2, signal transducer and activator of transcription (STAT)3 and -5, extracellular signal-regulated kinase (ERK)1/2 and p38 by Western blot; H2O2 concentration by a colorimetric method; MMP-1 mRNA levels and stability by Northern blot; MMP-1 promoter activity as well as pro-MMP-1 by ELISA; and active MMP-1 by fluorescence.. LX-2 cells constitutively expressed the MMP-1 gene and leptin repressed the basal level of MMP-1 mRNA and its promoter activity. The repression was mediated by JAK/STAT pathway in synergism with JAK-mediated H2O2-dependent ERK1/2 and p38 pathways. ERK1/2 inhibited MMP-1 promoter activity, whereas p38 decreased the message stability, contributing to mRNA down-regulation. Inhibition of MMP-1 gene diminished secreted pro-MMP-1 and active MMP-1.. Leptin represses MMP-1 gene expression via the synergistic actions of the JAK/STAT pathway and JAK-mediated H2O2-dependent ERK1/2 and p38 pathways.

Topics: Base Sequence; Catalase; Cell Line; Down-Regulation; Enzyme Inhibitors; Hepatocytes; Humans; Hydrogen Peroxide; Imidazoles; Janus Kinases; Leptin; Liver Cirrhosis; MAP Kinase Signaling System; Matrix Metalloproteinase 1; Models, Biological; Oligodeoxyribonucleotides, Antisense; Pyridines; RNA, Messenger; STAT3 Transcription Factor; STAT5 Transcription Factor; Tyrphostins