Histological and immunohistochemical effects of Curcuma longa on activation of rat hepatic stellate cells after cadmium induced hepatotoxicity.

PubMed

El-Mansy, A A; Mazroa, S A; Hamed, W S; Yaseen, A H; El-Mohandes, E A

2016-01-01

The liver is a target for toxic chemicals such as cadmium (Cd). When the liver is damaged, hepatic stellate cells (HSC) are activated and transformed into myofibroblast-like cells, which are responsible for liver fibrosis. Curcuma longa has been reported to exert a hepato-protective effect under various pathological conditions. We investigated the effects of C. longa administration on HSC activation in response to Cd induced hepatotoxicity. Forty adult male albino rats were divided into: group 1 (control), group 2 (Cd treated), group 3 (C. longa treated) and group 4 (Cd and C. longa treated). After 6 weeks, liver specimens were prepared for light and electron microscopy examination of histological changes and immunohistochemical localization of alpha smooth muscle actin (αSMA) as a specific marker for activated HSC. Activated HSC with a positive αSMA immune reaction were not detected in groups 1 and 3. Large numbers of activated HSC with αSMA immune reactions were observed in group 2 in addition to Cd induced hepatotoxic changes including excess collagen deposition in thickened portal triads, interlobular septa with hepatic lobulation, inflammatory cell infiltration, a significant increase in Kupffer cells and degenerated hepatocytes. In group 4, we observed a significant decrease in HSC that expressed αSMA with amelioration of the hepatotoxic changes. C. longa administration decreased HSC activation and ameliorated hepatotoxic changes caused by Cd in adult rats.

Lipid peroxidation products do not activate hepatic stellate cells.

PubMed

Fang, Hsun-Lang; Lin, Wen-Chuan

2008-11-20

Lipid peroxidation (LPO) is known to be associated with liver fibrosis in chronic liver injury. However, direct effects of the products of LPO on liver fibrogenesis are still not clear. In this study, we examined the LPO products, such as malondiladehyde (MDA), 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)), and 15-keto-13,14-dihydro-PGF(2alpha) (15-keto-PGF(2alpha)), on the activation of hepatic stellate cells (HSCs) in vivo and in vitro. Carbon tetrachloride (CCl(4)) was given orally to rats twice a week for 8 weeks. Corn oil was given daily to rats for 8 weeks. CCl(4) induced both free-radical-medicated and cyclooxygenase-2-dependent LPO. Free radical-medicated LPO showed an increase with corn oil treatment, whereas no effect was reflected on COX-2-dependent LPO. CCl(4) induced liver fibrosis in rats, but no liver fibrosis was observed in rats treated with corn oil. In vitro studies demonstrated that MDA, 8-iso-PGF(2alpha) and 15-keto-PGF(2alpha), did not activate HSCs, which were preactivated or not preactivated by TGF-beta1. Our results clearly indicate that LPO products, such as MDA, 8-iso-PGF(2alpha) and 15-keto-PGF(2alpha), cannot directly activate HSCs.

Oral vitamin-A-coupled valsartan nanomedicine: High hepatic stellate cell receptors accessibility and prolonged enterohepatic residence.

PubMed

El-Mezayen, Nesrine S; El-Hadidy, Wessam F; El-Refaie, Wessam M; Shalaby, Thanaa I; Khattab, Mahmoud M; El-Khatib, Aiman S

2018-05-22

So far, liver fibrosis still has no clinically-approved treatment. The loss of stored vitamin-A (V A ) in hepatic stellate cells (HSCs), the main regulators to hepatic fibrosis, can be applied as a mechanism for their targeting. Valsartan is a good candidate for this approach; it is a marketed oral-therapy with inverse- and partial-agonistic activity to the over-expressed angiotensin-II type1 receptor (AT1R) and depleted nuclear peroxisome proliferator-activated receptor-gamma (PPAR-γ), respectively, in activated HSCs. However, efficacy on AT1R and PPAR-γ necessitates high drug permeability which is lacking in valsartan. In the current study, liposomes were used as nanocarriers for valsartan to improve its permeability and hence efficacy. They were coupled to V A and characterized for HSCs-targeting. Tracing of orally-administered fluorescently-labeled V A -coupled liposomes in normal rats and their fluorescence intensity quantification in different organs convincingly demonstrated their intestinal entrapment. On the other hands, their administration to rats with induced fibrosis revealed preferential hepatic, and less intestinal, accumulation which lasted up to six days. This indicated their uptake by intestinal stellate cells that acted as a depot for their release over time. Confocal microscopical examination of immunofluorescently-stained HSCs in liver sections, with considerable formula accumulation, confirmed HSCs-targeting and nuclear uptake. Consequently, V A -coupled valsartan-loaded liposomes (VLC)-therapy resulted in profound re-expression of hepatic Mas-receptor and PPAR-γ, potent reduction of fibrogenic mediators' level and nearly normal liver function tests. Therefore, VLC epitomizes a promising antifibrotic therapy with exceptional extended action and additional PPAR-γ agonistic activity. Copyright © 2018 Elsevier B.V. All rights reserved.

Hepatic fibrosis: It is time to go with hepatic stellate cell-specific therapeutic targets.

PubMed

Ezhilarasan, Devaraj; Sokal, Etienne; Najimi, Mustapha

2018-06-01

Hepatic fibrosis is a pathological lesion, characterized by the progressive accumulation of extracellular matrix (ECM) in the perisinusoidal space and it is a major problem in chronic liver diseases. Phenotypic activation of hepatic stellate cells (HSC) plays a central role in the progression of hepatic fibrosis. Retardation of proliferation and clearance of activated HSCs from the injured liver is an appropriate therapeutic strategy for the resolution and treatment of hepatic fibrosis. Clearance of activated HSCs from the injured liver by autophagy inhibitors, proapoptotic agents and senescence inducers with the high affinity toward the activated HSCs may be the novel therapeutic strategy for the treatment of hepatic fibrosis in the near future. Copyright © 2018. Published by Elsevier B.V.

Amelioration of CCl4-induced liver injury in rats by selenizing Astragalus polysaccharides: Role of proinflammatory cytokines, oxidative stress and hepatic stellate cells.

PubMed

Hamid, Mohammed; Liu, Dandan; Abdulrahim, Yassin; Liu, Yunhuan; Qian, Gang; Khan, Alamzeb; Gan, Fang; Huang, Kehe

2017-10-01

Selenizing Astragalus polysaccharides (sAPS) were prepared by nitric acid-sodium selenite method. Effect of sAPS on carbon tetrachloride (CCl4)-induced liver injury and the underlying mechanisms were investigated in the rat. Forty male Wistar rats were divided into five equal groups as follows: control group; CCl 4 group; CCl 4 +Astragalus polysaccharides group; CCl 4 +sodium selenite group and CCl 4 +selenizing Astragalus polysaccharides group. The results showed that sAPS significantly decreased the levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase in the serum, malondialdehyde and hydroxyproline content in liver (P<0.01), and increased the levels of total protein, total antioxidant capacity, glutathione peroxidase, and superoxide dismutase in liver of rats induced by CCl 4. In addition, expression levels of antioxidant-related genes (GPX1, SOD1, and Nrf2) were significantly increased following supplementation of the sAPS (P<0.01). Furthermore, sAPS effectively ameliorated CCl 4 induced hepatic necrosis and inflammation, and it also reduced the expression levels of proinflammatory cytokines including TNF-α, IL-6, COX-2 and NFκB (P<0.01) . Moreover, sAPS significantly decreased the expression levels of α-smooth muscle actin, collagen 1, TGF-β1, but increased the Bcl-2/Bax mRNA ratio in rats administered CCl 4 (P<0.01). Taken together, it could be concluded that sAPS could increase the activities of Astragalus polysaccharides and sodium selenite to protect the liver from damage by attenuating hepatic inflammation, oxidative stress, fibrogenesis, and induces apoptosis and cell cycle arrest in hepatic stellate cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

Withagulatin A inhibits hepatic stellate cell viability and procollagen I production through Akt and Smad signaling pathways

PubMed Central

Liu, Qiong; Chen, Jing; Wang, Xu; Yu, Liang; Hu, Li-hong; Shen, Xu

2010-01-01

Aim: To investigate the effects of the natural product Withagulatin A on hepatic stellate cell (HSC) viability and type I procollagen production. The potential mechanism underlying the pharmacological actions was also explored. Methods: The effect of Withagulatin A on cell viability was evaluated in HSC and LX-2 cells using a sulforhodamine B (SRB) assay. Cell cycle distribution was analyzed using flow cytometry. Type I procollagen gene expression was determined using real-time PCR. Regulation of signaling molecules by Withagulatin A was detected using Western blotting. Results: Primary rat HSCs and the human hepatic stellate cell line LX-2 treated with Withagulatin A (0.625-20 μmol/L) underwent a dose-dependent decrease in cell viability, which was associated with S phase arrest and the induction of cell apoptosis. In addition, the natural product decreased phosphorylation of the Akt/mTOR/p70S6K pathway that controls cell proliferation and survival. Furthermore, Withagulatin A (1, 2 μmol/L) inhibited transforming growth factor-β (TGF-β) stimulated type I procollagen gene expression, which was attributable to the suppression of TGF-β stimulated Smad2 and Smad3 phosphorylation. Conclusion: Our results demonstrated that Withagulatin A potently inhibited HSC viability and type I procollagen production, thereby implying that this natural product has potential use in the development of anti-fibrogenic reagents for the treatment of hepatic fibrosis. PMID:20644552

Lymphotoxin-beta receptor signaling regulates hepatic stellate cell function and wound healing in a murine model of chronic liver injury.

PubMed

Ruddell, Richard G; Knight, Belinda; Tirnitz-Parker, Janina E E; Akhurst, Barbara; Summerville, Lesa; Subramaniam, V Nathan; Olynyk, John K; Ramm, Grant A

2009-01-01

Lymphotoxin-beta (LTbeta) is a proinflammatory cytokine and a member of the tumor necrosis factor (TNF) superfamily known for its role in mediating lymph node development and homeostasis. Our recent studies suggest a role for LTbeta in mediating the pathogenesis of human chronic liver disease. We hypothesize that LTbeta co-ordinates the wound healing response in liver injury via direct effects on hepatic stellate cells. This study used the choline-deficient, ethionine-supplemented (CDE) dietary model of chronic liver injury, which induces inflammation, liver progenitor cell proliferation, and portal fibrosis, to assess (1) the cellular expression of LTbeta, and (2) the role of LTbeta receptor (LTbetaR) in mediating wound healing, in LTbetaR(-/-) versus wild-type mice. In addition, primary isolates of hepatic stellate cells were treated with LTbetaR-ligands LTbeta and LTbeta-related inducible ligand competing for glycoprotein D binding to herpesvirus entry mediator on T cells (LIGHT), and mediators of hepatic stellate cell function and fibrogenesis were assessed. LTbeta was localized to progenitor cells immediately adjacent to activated hepatic stellate cells in the periportal region of the liver in wild-type mice fed the CDE diet. LTbetaR(-/-) mice fed the CDE diet showed significantly reduced fibrosis and a dysregulated immune response. LTbetaR was demonstrated on isolated hepatic stellate cells, which when stimulated by LTbeta and LIGHT, activated the nuclear factor kappa B (NF-kappaB) signaling pathway. Neither LTbeta nor LIGHT had any effect on alpha-smooth muscle actin, tissue inhibitor of metalloproteinase 1, transforming growth factor beta, or procollagen alpha(1)(I) expression; however, leukocyte recruitment-associated factors intercellular adhesion molecule 1 and regulated upon activation T cells expressed and secreted (RANTES) were markedly up-regulated. RANTES caused the chemotaxis of a liver progenitor cell line expressing CCR5. This study suggests that

[Curcumine inhibits migration and invasion of hepatic stellate cells by reducing MMP-2 expression and activity].

PubMed

Huang, Jian-xian; Zhu, Bao-he; He, De; Huang, Lin; Hu, Ke; Huang, Bo

2009-11-01

To investigate the molecular mechanism of the inhibitory effect of curcumine on the migration and invasion of hepatic stellate cells (HSC). Rat hepatic stellate cells were cultured and activated with ConA. Matrix metalloproteinase-2 (MMP-2) expression and activity was determined by Western blot and gelatin zymography. Migration and invasion of HSC was assessed by wound healing assay and modified Boyden chamber assay. Curcumine reduced the level and activity of MMP-2 expression in activated HSC in a dose-dependent manner. When treated with 25, 50 or 100 micromol/L curcumine, the expression of MMP-2 was reduced by 21.8%+/-5.1%, 65.5%+/-9.2% or 87.9%+/-11.5% (P < 0.05), and the activity of MMP-2 was also significantly reduced by curcumine. Migration and invasion of activated HSC was also inhibited by curcumine in a dose-dependent way. When treated with 25, 50 or 100 micromol/L curcumine, the migration of activated HSC was reduced by 27.5%+/-5.8%, 54.4%+/-7.6% or 67.1%+/-9.3% (P < 0.05), and the invasion of activated HSC was also significantly reduced by curcumine. Curcumine inhibits migration and invasion of activated HSC by reducing MMP-2 expression and activity.

Two novel antifibrotics, HOE 077 and Safironil, modulate stellate cell activation in rat liver injury: differential effects in males and females.

PubMed Central

Wang, Y. J.; Wang, S. S.; Bickel, M.; Guenzler, V.; Gerl, M.; Bissell, D. M.

1998-01-01

The perisinusoidal stellate cells of the liver in an injury milieu undergo activation, acquiring a myofibroblast-like phenotype. In this state, they are the principal source of collagen and related proteins in fibrosis. The present studies evaluate the mechanism of action of two novel antifibrotic compounds, HOE 077 and Safironil, which were designed as competitive inhibitors of collagen protein synthesis. Fibrosis was induced in rats by administration of carbon tetrachloride, and activation was monitored as the level of collagen I mRNA or smooth muscle alpha-actin. Both male and female rats were studied. Stellate cell activation, rather than collagen synthesis, proved to be the target of both HOE 077 and Safironil in the intact liver. In culture, the drugs not only prevented the activation of stellate cells but also accelerated their deactivation. They were no more effective in co-cultures containing hepatocytes than in pure stellate cell cultures, indicating that metabolic conversion of HOE 077 was not required. Interestingly, the response of cells from females was greater than that of male cells, leading to the conclusion that stellate activation is sexually dimorphic. This finding may be relevant to the observation that fibrosis in chronic viral hepatitis progresses less rapidly and that hepatocellular carcinoma is less frequent in females than in males. Images Figure 1 Figure 2 Figure 7 PMID:9422545

Low concentrations of bilirubin inhibit activation of hepatic stellate cells in vitro.

PubMed

Tang, Yinhe; Zhang, Qiyu; Zhu, Yefan; Chen, Gang; Yu, Fuxiang

2017-04-01

Hepatic stellate cell (HSC) activation serves a key role in liver fibrosis, and is associated with chronic liver diseases. Bilirubin, a product of heme degradation, has been demonstrated to have antioxidant properties. The present study investigated the effects of physiological concentrations of bilirubin on rat HSC activation. Rat HSCs were isolated and cultured for several generations to induce activation. The activated HSCs were subsequently treated with 0, 1, 10 or 20 mg/l bilirubin and assayed for parameters of cell activation. As the bilirubin concentration increased, HSCs demonstrated reduced production of reactive oxygen species, reduced protein expression levels of α‑smooth muscle actin, a decreased mRNA expression ratio of tissue inhibitor of matrix metalloproteinase‑1/matrix metalloproteinase‑2, decreased proliferation and increased apoptosis. In conclusion, elevated bilirubin levels, within its physiological concentration range, appeared to inhibit HSC activation. These findings suggested a potential role for bilirubin in the treatment of fibrosis that requires further investigation.

The improving effects on hepatic fibrosis of interferon-γ liposomes targeted to hepatic stellate cells

NASA Astrophysics Data System (ADS)

Li, Qinghua; Yan, Zhiqiang; Li, Feng; Lu, Weiyue; Wang, Jiyao; Guo, Chuanyong

2012-07-01

No satisfactory anti-fibrotic therapies have yet been applied clinically. One of the main reasons is the inability to specifically target the responsible cells to produce an available drug concentration and the side-effects. Exploiting the key role of the activated hepatic stellate cells (HSCs) in both hepatic fibrogenesis and over-expression of platelet-derived growth factor receptor-β (PDGFR-β), we constructed targeted sterically stable liposomes (SSLs) modified by a cyclic peptide (pPB) with affinity for the PDGFR-β to deliver interferon (IFN)-γ to HSCs. The pPB-SSL-IFN-γ showed satisfactory size distribution. In vitro pPB-SSL could be taken up by activated HSCs. The study of tissue distribution via living-body animal imaging showed that the pPB-SSL-IFN-γ mostly accumulated in the liver until 24 h. Furthermore, the pPB-SSL-IFN-γ showed more significant remission of hepatic fibrosis. In vivo the histological Ishak stage, the semiquantitative score for collagen in fibrotic liver and the serum levels of collagen type IV-C in fibrotic rats treated with pPB-SSL-IFN-γ were less than those treated with SSL-IFN-γ, IFN-γ and the control group. In vitro pPB-SSL-IFN-γ was also more effective in suppressing activated HSC proliferation and inducing apoptosis of activated HSCs. Thus the data suggest that pPB-SSL-IFN-γ might be a more effective anti-fibrotic agent and a new opportunity for clinical therapy of hepatic fibrosis.

ATGL and CGI-58 are lipid droplet proteins of the hepatic stellate cell line HSC-T6.

PubMed

Eichmann, Thomas O; Grumet, Lukas; Taschler, Ulrike; Hartler, Jürgen; Heier, Christoph; Woblistin, Aaron; Pajed, Laura; Kollroser, Manfred; Rechberger, Gerald; Thallinger, Gerhard G; Zechner, Rudolf; Haemmerle, Günter; Zimmermann, Robert; Lass, Achim

2015-10-01

Lipid droplets (LDs) of hepatic stellate cells (HSCs) contain large amounts of vitamin A [in the form of retinyl esters (REs)] as well as other neutral lipids such as TGs. During times of insufficient vitamin A availability, RE stores are mobilized to ensure a constant supply to the body. To date, little is known about the enzymes responsible for the hydrolysis of neutral lipid esters, in particular of REs, in HSCs. In this study, we aimed to identify LD-associated neutral lipid hydrolases by a proteomic approach using the rat stellate cell line HSC-T6. First, we loaded cells with retinol and FAs to promote lipid synthesis and deposition within LDs. Then, LDs were isolated and lipid composition and the LD proteome were analyzed. Among other proteins, we found perilipin 2, adipose TG lipase (ATGL), and comparative gene identification-58 (CGI-58), known and established LD proteins. Bioinformatic search of the LD proteome for α/β-hydrolase fold-containing proteins revealed no yet uncharacterized neutral lipid hydrolases. In in vitro activity assays, we show that rat (r)ATGL, coactivated by rat (r)CGI-58, efficiently hydrolyzes TGs and REs. These findings suggest that rATGL and rCGI-58 are LD-resident proteins in HSCs and participate in the mobilization of both REs and TGs. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

Estrogen receptor β selective agonist ameliorates liver cirrhosis in rats by inhibiting the activation and proliferation of hepatic stellate cells.

PubMed

Zhang, Bin; Zhang, Cheng-Gang; Ji, Lin-Hua; Zhao, Gang; Wu, Zhi-Yong

2018-03-01

The aim of this study is to explore the roles of estrogen receptor (ER) subtypes and corresponding agonists/antagonists on the development of cirrhosis and activation and proliferation of hepatic stellate cells (HSCs). Carbon tetrachloride (CCl 4 )-induced cirrhotic ovariectomized rats were administered non-selective ER agonist (β-estradiol, E2), ER selective agonists (ERα agonist, propylpyrazoletriol; ERβ agonist, diarylpropionitrile [DPN]; and G-protein-coupled ER [GPER] agonist, G1), or E2 + ER selective antagonists (ERα antagonist, MPP; ERβ antagonist, PHTPP; and GPER antagonist, G15) for 12 weeks. The expression of the three ER subtypes in livers and HSCs and the effects of the drugs on hepatic fibrosis, isolated HSCs, and uteri were evaluated. Selective ER agonists/antagonists had various effects on CCl 4 -induced cirrhosis. The cirrhotic rats in the CCl 4  + E2, CCl 4  + DPN, CCl 4  + E2 + MPP, and CCl 4  + E2 + G15 groups presented reduced fibrosis scores, compared with those in the CCl 4 group. The cirrhotic rats in the E2 + PHTPP group presented increased fibrosis scores that similar to those in the CCl 4 group. The ovariectomized rats had enlarged uteri with increased uterus indexes after E2 administration; however, the proliferative effects of E2 were partially blocked by MPP or G15, but not PHTPP. In the in vitro study, DPN attenuated the transformation of quiescent HSCs to activated phenotype, suppressed collagen I, and α-smooth muscle actin expression. DPN also suppressed platelet-derived growth factor-induced proliferation in cultured HSCs, which was reversed by PHTPP. The antifibrogenic effects of estrogen were mediated by ERβ but not ERα or GPER. The ERβ selective agonist exerted a fibrosuppressive effect by inhibiting the activation and proliferation of HSCs, but did not induce uterine hyperplasia. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Periostin promotes liver fibrogenesis by activating lysyl oxidase in hepatic stellate cells.

PubMed

Kumar, Pradeep; Smith, Tekla; Raeman, Reben; Chopyk, Daniel M; Brink, Hannah; Liu, Yunshan; Sulchek, Todd; Anania, Frank A

2018-06-25

Liver fibrosis arises from dysregulated wound healing due to persistent inflammatory hepatic injury. Periostin is a non-structural extracellular matrix protein that promotes organ fibrosis in adults. Here, we sought to identify the molecular mechanisms in periostin-mediated hepatic fibrosis. Hepatic fibrosis in periostin -/- mice was attenuated as evidenced by significantly reduced collagen fibril density and liver stiffness compared with those in WT controls. A single dose of carbon tetrachloride caused similar acute liver injury in periostin -/- and WT littermates, and we did not detect significant differences in transaminases and major fibrosis-related hepatic gene expression between these two genotypes. Activated hepatic stellate cells (HSCs) are the major periostin-producing liver cell type. We found that in primary rat HSCs in vitro, periostin significantly increases the expression levels and activities of lysyl oxidase (LOX) and lysyl oxidase-like (LOXL) isoforms 1-3. Periostin also induced expression of intra- and extracellular collagen type 1 and fibronectin in HSCs. Interestingly, periostin stimulated phosphorylation of SMAD2/3, which was sustained despite sh-RNA mediated knockdown of transforming growth factor β (TGFβ) receptor I and II, indicating that periostin periostin-mediated SMAD2/3 phosphorylation is independent of TGFβ receptors. Moreover, periostin induced the phosphorylation of focal adhesion kinase (FAK) and AKT in HSCs. Notably, si-RNA mediated FAK knockdown failed to block periostin-induced SMAD2/3 phosphorylation. These results suggest that periostin promotes enhanced matrix stiffness in chronic liver disease by activating LOX and LOXL, independently of TGFβ receptors. Hence, targeting periostin may be of therapeutic benefit in combating hepatic fibrosis. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Accumulation of vitamin A in the hepatic stellate cell of arctic top predators.

PubMed

Senoo, Haruki; Imai, Katsuyuki; Mezaki, Yoshihiro; Miura, Mitsutaka; Morii, Mayako; Fujiwara, Mutsunori; Blomhoff, Rune

2012-10-01

We performed a systematic characterization of the hepatic vitamin A storage in mammals and birds of the Svalbard Archipelago and Greenland. The liver of top predators, including polar bear, Arctic fox, bearded seal, and glaucous gull, contained about 10-20 times more vitamin A than the liver of all other arctic animals studied, as well as their genetically related continental top predators. The values are also high compared to normal human and experimental animals like mouse and rat. This massive amount of hepatic vitamin A was located in large autofluorescent lipid droplets in hepatic stellate cells (HSCs; also called vitamin A-storing cells, lipocytes, interstitial cells, fat-storing cells, or Ito cells). The droplets made up most of the cells' cytoplasm. The development of such an efficient vitamin A-storing mechanism in HSCs may have contributed to the survival of top predators in the extreme environment of the arctic. These animals demonstrated no signs of hypervitaminosis A. We suggest that HSCs have capacity to take-up and store large amounts of vitamin A, which may play a pivotal role in maintenance of the food web, food chain, biodiversity, and eventually ecology of the arctic. Copyright © 2012 Wiley Periodicals, Inc.

Curcumin attenuates angiogenesis in liver fibrosis and inhibits angiogenic properties of hepatic stellate cells

PubMed Central

Zhang, Feng; Zhang, Zili; Chen, Li; Kong, Desong; Zhang, Xiaoping; Lu, Chunfeng; Lu, Yin; Zheng, Shizhong

2014-01-01

Hepatic fibrosis is concomitant with sinusoidal pathological angiogenesis, which has been highlighted as novel therapeutic targets for the treatment of chronic liver disease. Our prior studies have demonstrated that curcumin has potent antifibrotic activity, but the mechanisms remain to be elucidated. The current work demonstrated that curcumin ameliorated fibrotic injury and sinusoidal angiogenesis in rat liver with fibrosis caused by carbon tetrachloride. Curcumin reduced the expression of a number of angiogenic markers in fibrotic liver. Experiments in vitro showed that the viability and vascularization of rat liver sinusoidal endothelial cells and rat aortic ring angiogenesis were not impaired by curcumin. These results indicated that hepatic stellate cells (HSCs) that are characterized as liver-specific pericytes could be potential target cells for curcumin. Further investigations showed that curcumin inhibited VEGF expression in HSCs associated with disrupting platelet-derived growth factor-β receptor (PDGF-βR)/ERK and mTOR pathways. HSC motility and vascularization were also suppressed by curcumin associated with blocking PDGF-βR/focal adhesion kinase/RhoA cascade. Gain- or loss-of-function analyses revealed that activation of peroxisome proliferator-activated receptor-γ (PPAR-γ) was required for curcumin to inhibit angiogenic properties of HSCs. We concluded that curcumin attenuated sinusoidal angiogenesis in liver fibrosis possibly by targeting HSCs via a PPAR-γ activation-dependent mechanism. PPAR-γ could be a target molecule for reducing pathological angiogenesis during liver fibrosis. PMID:24779927

Suppression of hepatic stellate cell activation by microRNA-29b

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sekiya, Yumiko; Ogawa, Tomohiro; Liver Research Center, Graduate School of Medicine, Osaka City University, Osaka

Highlights: {yields} Expression of miR-29b was found to be down-regulated during the activation of hepatic stellate cells in primary culture. {yields} Transfection of a miR-29b precursor markedly attenuated the expression of Col1a1 and Col1a2 mRNAs. {yields} It blunted the increased expression of {alpha}-SMA, DDR2, FN1, ITGB1, and PDGFR-b mRNAs essential for stellate cell activation. {yields} miR-29b overexpression led stellate cells to remain in a quiescent state, as evidenced by their star-like morphology. {yields} miR-29b overexpression suppressed the expression of c-fos mRNA. -- Abstract: MicroRNAs (miRNAs) participate in the regulation of cellular functions including proliferation, apoptosis, and migration. It has beenmore » previously shown that the miR-29 family is involved in regulating type I collagen expression by interacting with the 3'UTR of its mRNA. Here, we investigated the roles of miR-29b in the activation of mouse primary-cultured hepatic stellate cells (HSCs), a principal collagen-producing cell in the liver. Expression of miR-29b was found to be down-regulated during HSC activation in primary culture. Transfection of a miR-29b precursor markedly attenuated the expression of Col1a1 and Col1a2 mRNAs and additionally blunted the increased expression of {alpha}-SMA, DDR2, FN1, ITGB1, and PDGFR-{beta}, which are key genes involved in the activation of HSCs. Further, overexpression of miR-29b led HSCs to remain in a quiescent state, as evidenced by their quiescent star-like cell morphology. Although phosphorylation of FAK, ERK, and Akt, and the mRNA expression of c-jun was unaffected, miR-29b overexpression suppressed the expression of c-fos mRNA. These results suggested that miR-29b is involved in the activation of HSCs and could be a candidate molecule for suppressing their activation and consequent liver fibrosis.« less

Glial Fibrillary Acidic Protein (GFAP) as a Mesenchymal marker of Early Hepatic Stellate Cells Activation in Liver Fibrosis in Chronic Hepatitis C Infection

PubMed Central

Hassan, Sobia; Syed, Serajuddaula; Kehar, Shahnaz Imdad

2014-01-01

Objective: This study aims to determine expression of Glial Fibrillary Acidic Protein and of Alpha Smooth Muscle Actin (α-SMA) in hepatic stellate cells of CHC cases and their association with stage of fibrosis. Methods: The study was conducted at Ziauddin University, Clifton Campus during the year 2010-2012. Sixty Chronic Hepatitis C cases were immmunostained using anti α-SMA antibody and anti-GFAP antibody. Semi quantitative scoring in pericentral, periportal and perisinusoidal area of each case was done to assess immunoexpression of each marker. Results : Immunoexpression of GFAP showed significant association with α-SMA. GFAP expression was inversely correlated with progression of fibrosis. Conclusion : GFAP could represent a useful marker for early hepatic stellate cells activation. Follow up biopsies showing decline in GFAP levels may help identify the target group requiring aggressive therapy. PMID:25225520

Clinical associations of hepatic stellate cell (HSC) hyperplasia.

PubMed

Mounajjed, Taofic; Graham, Rondell P; Sanderson, Schuyler O; Smyrk, Thomas C

2014-07-01

Hepatic stellate cell (HSC) hyperplasia has been principally attributed to hypervitaminosis A. There are sporadic reports of HSC hyperplasia in other conditions such as chronic biliary disease and hepatitis C, but clinical associations of this entity have not been studied in detail. We aimed to investigate the clinical associations of HSC hyperplasia aside from hypervitaminosis A. We identified 34 patients whose liver histology showed HSC hyperplasia. We reviewed the liver samples; additional histologic findings in addition to HSC hyperplasia were consolidated into a histologic diagnosis. We collected clinical, laboratory, and radiologic data; the histologic diagnosis was combined with this data to reach an "overall diagnosis." Four patients had hypervitaminosis A (all native livers). In native livers (n = 24), HSC hyperplasia also occurred in association with drug-induced hepatitis [n = 6, niacin was the most common inducing agent (n = 3)], reactive hepatitis (n = 4), chronic hepatitis C (n = 4), autoimmune hepatitis (n = 3), steatohepatitis (n = 1), chronic biliary disease (n = 1), and portal venopathy (n = 1). In liver allografts (n = 10), HSC hyperplasia was seen in protocol biopsies without other significant abnormalities (n = 5), chronic biliary disease (n = 4), and acute cellular rejection (n = 1). All patients used medications (total of 99) and 82 % were on multiple medications. HSC hyperplasia is an uncommon and relatively nonspecific finding that most commonly occurs in multimedicated patients, often in the absence of hypervitaminosis A. Associated conditions include drug toxicity (such as niacin), post-liver transplant setting, reactive hepatitis (due to systemic illness or inflammatory disorders of the gastrointestinal tract), and chronic liver disease.

Systemic PEGylated TRAIL treatment ameliorates liver cirrhosis in rats by eliminating activated hepatic stellate cells.

PubMed

Oh, Yumin; Park, Ogyi; Swierczewska, Magdalena; Hamilton, James P; Park, Jong-Sung; Kim, Tae Hyung; Lim, Sung-Mook; Eom, Hana; Jo, Dong Gyu; Lee, Choong-Eun; Kechrid, Raouf; Mastorakos, Panagiotis; Zhang, Clark; Hahn, Sei Kwang; Jeon, Ok-Cheol; Byun, Youngro; Kim, Kwangmeyung; Hanes, Justin; Lee, Kang Choon; Pomper, Martin G; Gao, Bin; Lee, Seulki

2016-07-01

Liver fibrosis is a common outcome of chronic liver disease that leads to liver cirrhosis and hepatocellular carcinoma. No US Food and Drug Administration-approved targeted antifibrotic therapy exists. Activated hepatic stellate cells (aHSCs) are the major cell types responsible for liver fibrosis; therefore, eradication of aHSCs, while preserving quiescent HSCs and other normal cells, is a logical strategy to stop and/or reverse liver fibrogenesis/fibrosis. However, there are no effective approaches to specifically deplete aHSCs during fibrosis without systemic toxicity. aHSCs are associated with elevated expression of death receptors and become sensitive to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cell death. Treatment with recombinant TRAIL could be a potential strategy to ameliorate liver fibrosis; however, the therapeutic application of recombinant TRAIL is halted due to its very short half-life. To overcome this problem, we previously generated PEGylated TRAIL (TRAILPEG ) that has a much longer half-life in rodents than native-type TRAIL. In this study, we demonstrate that intravenous TRAILPEG has a markedly extended half-life over native-type TRAIL in nonhuman primates and has no toxicity in primary human hepatocytes. Intravenous injection of TRAILPEG directly induces apoptosis of aHSCs in vivo and ameliorates carbon tetrachloride-induced fibrosis/cirrhosis in rats by simultaneously down-regulating multiple key fibrotic markers that are associated with aHSCs. TRAIL-based therapies could serve as new therapeutics for liver fibrosis/cirrhosis and possibly other fibrotic diseases. (Hepatology 2016;64:209-223). © 2015 by the American Association for the Study of Liver Diseases.

Dihydroartemisinin counteracts fibrotic portal hypertension via farnesoid X receptor-dependent inhibition of hepatic stellate cell contraction.

PubMed

Xu, Wenxuan; Lu, Chunfeng; Zhang, Feng; Shao, Jiangjuan; Yao, Shunyu; Zheng, Shizhong

2017-01-01

Portal hypertension is a frequent pathological symptom occurring especially in hepatic fibrosis and cirrhosis. Current paradigms indicate that inhibition of hepatic stellate cell (HSC) activation and contraction is anticipated to be an attractive therapeutic strategy, because activated HSC dominantly facilitates an increase in intrahepatic vein pressure through secreting extracellular matrix and contracting. Our previous in vitro study indicated that dihydroartemisinin (DHA) inhibited contractility of cultured HSC by activating intracellular farnesoid X receptor (FXR). However, the effect of DHA on fibrosis-related portal hypertension still requires clarification. In this study, gain- and loss-of-function models of FXR in HSC were established to investigate the mechanisms underlying DHA protection against chronic CCl 4 -caused hepatic fibrosis and portal hypertension. Immunofluorescence staining visually showed a decrease in FXR expression in CCl 4 -administrated rat HSC but an increase in that in DHA-treated rat HSC. Serum diagnostics and morphological analyses consistently indicated that DHA exhibited hepatoprotective effects on CCl 4 -induced liver injury. DHA also reduced CCl 4 -caused inflammatory mediator expression and inflammatory cell infiltration. These improvements were further enhanced by INT-747 but weakened by Z-guggulsterone. Noteworthily, DHA, analogous to INT-747, significantly lowered portal vein pressure and suppressed fibrogenesis. Experiments on mice using FXR shRNA lentivirus consolidated the results above. Mechanistically, inhibition of HSC activation and contraction was found as a cellular basis for DHA to relieve portal hypertension. These findings demonstrated that DHA attenuated portal hypertension in fibrotic rodents possibly by targeting HSC contraction via a FXR activation-dependent mechanism. FXR could be a target molecule for reducing portal hypertension during hepatic fibrosis. © 2016 Federation of European Biochemical Societies.

Anti-fibrotic effects of Orostachys japonicus A. Berger (Crassulaceae) on hepatic stellate cells and thioacetamide-induced fibrosis in rats.

PubMed

Koppula, Sushruta; Yum, Mun-Jeong; Kim, Jin-Seoub; Shin, Gwang-Mo; Chae, Yun-Jin; Yoon, Tony; Chun, Chi-Su; Lee, Jae-Dong; Song, MinDong

2017-12-01

Orostachys japonicus A. Berger (Crassulaceae) has been used in traditional herbal medicines in Korea and other Asian countries to treat various diseases, including liver disorders. In the present study, the anti-fibrotic effects of O. japonicus extract (OJE) in cellular and experimental hepatofibrotic rat models were investigated. An in vitro hepatic stellate cells (HSCs) system was used to estimate cell viability, cell cycle and apoptosis by MTT assay, flow cytometry, and Annexin V-FITC/PI staining techniques, respectively. In addition, thioacetamide (TAA)-induced liver fibrosis was established in Sprague Dawley rats. Briefly, animals were divided into five groups (n = 8): Control, TAA, OJE 10 (TAA with OJE 10 mg/kg), OJE 100 (TAA with OJE 100 mg/kg) and silymarin (TAA with Silymarin 50 mg/kg). Fibrosis was induced by treatment with TAA (200 mg/kg, i.p. ) twice per week for 13 weeks, while OJE and silymarin were administered orally two times per week from week 7 to 13. The fibrotic related gene expression serum biomarkers glutathione and hydroxyproline were estimated by RT-PCR and spectrophotometry, respectively, using commercial kits. OJE (0.5 and 0.1 mg/mL) and silymarin (0.05 mg/mL) treatment significantly ( P < 0.01 and P < 0.001) induced apoptosis (16.95% and 27.48% for OJE and 25.87% for silymarin, respectively) in HSC-T6 cells when compared with the control group (9.09%). Further, rat primary HSCs showed changes in morphology in response to OJE 0.1 mg/mL treatment. In in vivo studies, OJE (10 and 100 mg/kg) treatment significantly ameliorated TAA-induced alterations in levels of serum biomarkers, fibrotic related gene expression, glutathione, and hydroxyproline ( P < 0.05- P < 0.001) and rescued the histopathological changes. OJE can be developed as a potential agent for the treatment of hepatofibrosis.

Adenoviral overexpression of Lhx2 attenuates cell viability but does not preserve the stem cell like phenotype of hepatic stellate cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Genz, Berit; Thomas, Maria; Pützer, Brigitte M.

2014-11-01

Hepatic stellate cells (HSC) are well known initiators of hepatic fibrosis. After liver cell damage, HSC transdifferentiate into proliferative myofibroblasts, representing the major source of extracellular matrix in the fibrotic organ. Recent studies also demonstrate a role of HSC as progenitor or stem cell like cells in liver regeneration. Lhx2 is described as stem cell maintaining factor in different organs and as an inhibitory transcription factor in HSC activation. Here we examined whether a continuous expression of Lhx2 in HSC could attenuate their activation and whether Lhx2 could serve as a potential target for antifibrotic gene therapy. Therefore, we evaluatedmore » an adenoviral mediated overexpression of Lhx2 in primary HSC and investigated mRNA expression patterns by qRT-PCR as well as the activation status by different in vitro assays. HSC revealed a marked increase in activation markers like smooth muscle actin alpha (αSMA) and collagen 1α independent from adenoviral transduction. Lhx2 overexpression resulted in attenuated cell viability as shown by a slightly hampered migratory and contractile phenotype of HSC. Expression of stem cell factors or signaling components was also unaffected by Lhx2. Summarizing these results, we found no antifibrotic or stem cell maintaining effect of Lhx2 overexpression in primary HSC. - Highlights: • We performed adenoviral overexpression of Lhx2 in primary hepatic stellate cells. • Hepatic stellate cells expressed stem cell markers during cultivation. • Cell migration and contractility was slightly hampered upon Lhx2 overexpression. • Lhx2 overexpression did not affect stem cell character of hepatic stellate cells.« less

TRPM7 channel regulates PDGF-BB-induced proliferation of hepatic stellate cells via PI3K and ERK pathways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang, Ling, E-mail: fangling_1984@126.com; Zhan, Shuxiang; Huang, Cheng

2013-11-01

TRPM7, a non-selective cation channel of the TRP channel superfamily, is implicated in diverse physiological and pathological processes including cell proliferation. Recently, TRPM7 has been reported in hepatic stellate cells (HSCs). Here, we investigated the contribution role of TRPM7 in activated HSC-T6 cell (a rat hepatic stellate cell line) proliferation. TRPM7 mRNA and protein were measured by RT-PCR and Western blot in rat model of liver fibrosis in vivo and PDGF-BB-activated HSC-T6 cells in vitro. Both mRNA and protein of TRPM7 were dramatically increased in CCl{sub 4}-treated rat livers. Stimulation of HSC-T6 cells with PDGF-BB resulted in a time-dependent increasemore » of TRPM7 mRNA and protein. However, PDGF-BB-induced HSC-T6 cell proliferation was inhibited by non-specific TRPM7 blocker 2-aminoethoxydiphenyl borate (2-APB) or synthetic siRNA targeting TRPM7, and this was accompanied by downregulation of cell cycle proteins, cyclin D1, PCNA and CDK4. Blockade of TRPM7 channels also attenuated PDGF-BB induced expression of myofibroblast markers as measured by the induction of α-SMA and Col1α1. Furthermore, the phosphorylation of ERK and AKT, associated with cell proliferation, decreased in TRPM7 deficient HSC-T6 cells. These observations suggested that TRPM7 channels contribute to perpetuated fibroblast activation and proliferation of PDGF-BB induced HSC-T6 cells via the activation of ERK and PI3K pathways. Therefore, TRPM7 may constitute a useful target for the treatment of liver fibrosis. - Highlights: • Upregulation of TRPM7 mRNA and protein in the fibrotic livers from CCl{sub 4}-treated rats. • Increasing expression of TRPM7 mRNA and protein during HSC activation. • Blockade of TRPM7 inhibited the PDGF-BB induced proliferation of HSC-T6 cells. • Blockade of TRPM7 decreased α-SMA and Col1α1 expressions in activated HSC-T6 cells. • TRPM7 up-regulation contributes to the activation of ERK and AKT pathways.« less

Hepatic stellate cells: fibrogenic, regenerative or both? Heterogeneity and context are key.

PubMed

Bansal, Meena B

2016-11-01

Since their original identification, our understanding of the role of hepatic stellate cells in both health and disease continues to grow. Numerous studies have delineated the role of stellate cell activation in contributing to the pool of myofibroblasts responsible for liver fibrosis, and these have resulted in the development of a number of anti-fibrotic strategies targeting this cell. However, their potential role in liver regeneration, both initiation and termination, is also emerging and needs to be contemplated when considering targeted therapy. Perhaps what is most striking is the increasing recognition that this is not just one cell, but rather, a heterogenous population made up of a number of different subsets of cells, each with differentiated and specific functions. The tools are emerging for this dissection and are greatly needed to truly develop targeted therapies that will inhibit fibrosis while promoting liver regeneration and repair.

Vitamin B12 supplement alleviates N'-nitrosodimethylamine-induced hepatic fibrosis in rats.

PubMed

Ahmad, Areeba; Afroz, Nishat; Gupta, Umesh D; Ahmad, Riaz

2014-01-10

Abstract Context: Altered vitamin B 12 levels have been correlated with hepatotoxicity; however, further evidence is required to establish its protective role. Objective: To evaluate the effects of vitamin B 12 supplement in protecting N'-nitrosodimethylamine (NDMA)-induced hepatic fibrosis in Wistar rats. Materials and methods: Hepatic fibrosis was induced by administering NDMA in doses of 10 mg/kg body weight thrice a week for 21 days. Another group received equal doses (10 mg/kg body weight) of vitamin B 12 subsequent to NDMA treatment. Animals from either group were sacrificed weekly from the start of the treatment along with their respective controls. Progression of hepatic fibrosis, in addition to the effect of vitamin B 12 , was assessed biochemically for liver function biomarkers, liver glycogen, hydroxyproline (HP) and B 12 reserves along with histopathologically by hematoxylin and eosin (H & E) as well immunohistochemical staining for α-SMA expression. Results and discussion: Elevation in the levels of aminotransferases, SALP, total bilirubin and HP was observed in NDMA treated rats, which was concomitant with remarkable depletion in liver glycogen and B 12 reserves (p < 0.05). Liver biopsies also demonstrated disrupted lobular architecture, collagen amassing and intense fibrosis by NDMA treatment. Immunohistochemical staining showed the presence of activated stellate cells that was dramatically increased up to day 21 in fibrotic rats. Following vitamin B 12 treatment, liver function biomarkers, glycogen contents and hepatic vitamin B 12 reserves were restored in fibrotic rats, significantly. Vitamin B 12 administration also facilitated restoration of normal liver architecture. Conclusion: These findings provide interesting new evidence in favor of protective role for vitamin B 12 against NDMA-induced hepatic fibrosis in rats.

Anti-fibrotic effects of Orostachys japonicus A. Berger (Crassulaceae) on hepatic stellate cells and thioacetamide-induced fibrosis in rats

PubMed Central

Koppula, Sushruta; Yum, Mun-Jeong; Kim, Jin-Seoub; Shin, Gwang-Mo; Chae, Yun-Jin; Yoon, Tony; Chun, Chi-Su; Lee, Jae-Dong

2017-01-01

BACKGROUND/OBJECTIVE Orostachys japonicus A. Berger (Crassulaceae) has been used in traditional herbal medicines in Korea and other Asian countries to treat various diseases, including liver disorders. In the present study, the anti-fibrotic effects of O. japonicus extract (OJE) in cellular and experimental hepatofibrotic rat models were investigated. MATERIALS/METHODS An in vitro hepatic stellate cells (HSCs) system was used to estimate cell viability, cell cycle and apoptosis by MTT assay, flow cytometry, and Annexin V-FITC/PI staining techniques, respectively. In addition, thioacetamide (TAA)-induced liver fibrosis was established in Sprague Dawley rats. Briefly, animals were divided into five groups (n = 8): Control, TAA, OJE 10 (TAA with OJE 10 mg/kg), OJE 100 (TAA with OJE 100 mg/kg) and silymarin (TAA with Silymarin 50 mg/kg). Fibrosis was induced by treatment with TAA (200 mg/kg, i.p.) twice per week for 13 weeks, while OJE and silymarin were administered orally two times per week from week 7 to 13. The fibrotic related gene expression serum biomarkers glutathione and hydroxyproline were estimated by RT-PCR and spectrophotometry, respectively, using commercial kits. RESULTS OJE (0.5 and 0.1 mg/mL) and silymarin (0.05 mg/mL) treatment significantly (P < 0.01 and P < 0.001) induced apoptosis (16.95% and 27.48% for OJE and 25.87% for silymarin, respectively) in HSC-T6 cells when compared with the control group (9.09%). Further, rat primary HSCs showed changes in morphology in response to OJE 0.1 mg/mL treatment. In in vivo studies, OJE (10 and 100 mg/kg) treatment significantly ameliorated TAA-induced alterations in levels of serum biomarkers, fibrotic related gene expression, glutathione, and hydroxyproline (P < 0.05-P < 0.001) and rescued the histopathological changes. CONCLUSIONS OJE can be developed as a potential agent for the treatment of hepatofibrosis. PMID:29209457

Protective effects of L-carnosine on CCl4 -induced hepatic injury in rats.

PubMed

Alsheblak, Mehyar Mohammad; Elsherbiny, Nehal M; El-Karef, Amro; El-Shishtawy, Mamdouh M

2016-03-01

The present study was undertaken to investigate the possible protective effect of L-carnosine (CAR), an endogenous dipeptide of alanine and histidine, on carbon tetrachloride (CCl4)-induced hepatic injury. Liver injury was induced in male Sprague-Dawley rats by intraperitoneal (i.p.) injections of CCl4, twice weekly for six weeks. CAR was administered to rats daily, at dose of 250 mg/kg, i.p. At the end of six weeks, blood and liver tissue specimens were collected. Results show that CAR treatment attenuated the hepatic morphological changes, necroinflammation and fibrosis induced by CCl4, as indicated by hepatic histopathology scoring. In addition, CAR treatment significantly reduced the CCl4-induced elevation of liver-injury parameters in serum. CAR treatment also combatted oxidative stress; possibly by restoring hepatic nuclear factor erythroid 2-related factor 2 (Nrf-2) levels. Moreover, CAR treatment prevented the activation of hepatic stellate cells (HSCs), as indicated by reduced α-smooth muscle actin (α-SMA) expression in the liver, and decreased hepatic inflammation as demonstrated by a reduction in hepatic tumor necrosis factor-α (TNF-α) and restoration of interleukin-10 (IL-10) levels. In conclusion, CCl4-induced hepatic injury was alleviated by CAR treatment. The results suggest that these beneficial, protective effects are due, at least in part, to its anti-oxidant, anti-inflammatory and anti-fibrotic activities.

Some Lipid Droplets Are More Equal Than Others: Different Metabolic Lipid Droplet Pools in Hepatic Stellate Cells.

PubMed

Molenaar, Martijn R; Vaandrager, Arie B; Helms, J Bernd

2017-01-01

Hepatic stellate cells (HSCs) are professional lipid-storing cells and are unique in their property to store most of the retinol (vitamin A) as retinyl esters in large-sized lipid droplets. Hepatic stellate cell activation is a critical step in the development of chronic liver disease, as activated HSCs cause fibrosis. During activation, HSCs lose their lipid droplets containing triacylglycerols, cholesteryl esters, and retinyl esters. Lipidomic analysis revealed that the dynamics of disappearance of these different classes of neutral lipids are, however, very different from each other. Although retinyl esters steadily decrease during HSC activation, triacylglycerols have multiple pools one of which becomes transiently enriched in polyunsaturated fatty acids before disappearing. These observations are consistent with the existence of preexisting "original" lipid droplets with relatively slow turnover and rapidly recycling lipid droplets that transiently appear during activation of HSCs. Elucidation of the molecular machinery involved in the regulation of these distinct lipid droplet pools may open new avenues for the treatment of liver fibrosis.

Pancreatic Stellate Cells Have Distinct Characteristics From Hepatic Stellate Cells and Are Not the Unique Origin of Collagen-Producing Cells in the Pancreas.

PubMed

Yamamoto, Gen; Taura, Kojiro; Iwaisako, Keiko; Asagiri, Masataka; Ito, Shinji; Koyama, Yukinori; Tanabe, Kazutaka; Iguchi, Kohta; Satoh, Motohiko; Nishio, Takahiro; Okuda, Yukihiro; Ikeno, Yoshinobu; Yoshino, Kenji; Seo, Satoru; Hatano, Etsuro; Uemoto, Shinji

2017-10-01

The origin of collagen-producing myofibroblasts in pancreatic fibrosis is still controversial. Pancreatic stellate cells (PSCs), which have been recognized as the pancreatic counterparts of hepatic stellate cells (HSCs), are thought to play an important role in the development of pancreatic fibrosis. However, sources of myofibroblasts other than PSCs may exist because extensive studies of liver fibrosis have uncovered myofibroblasts that did not originate from HSCs. This study aimed to characterize myofibroblasts in an experimental pancreatic fibrosis model in mice. We used transgenic mice expressing green fluorescent protein via the collagen type I α1 promoter and induced pancreatic fibrosis with repetitive injections of cerulein. Collagen-producing cells that are negative for glial fibrillary acidic protein (ie, not derived from PSCs) exist in the pancreas. Pancreatic stellate cells had different characteristics from those of HSCs in a very small possession of vitamin A using mass spectrometry and a low expression of lecithin retinol acyltransferase. The microstructure of PSCs was entirely different from that of HSCs using flow cytometry and electron microscopy. Our study showed that characteristics of PSCs are different from those of HSCs, and myofibroblasts in the pancreas might be derived not only from PSCs but also from other fibrogenic cells.

FXR agonist obeticholic acid reduces hepatic inflammation and fibrosis in a rat model of toxic cirrhosis

PubMed Central

Verbeke, Len; Mannaerts, Inge; Schierwagen, Robert; Govaere, Olivier; Klein, Sabine; Vander Elst, Ingrid; Windmolders, Petra; Farre, Ricard; Wenes, Mathias; Mazzone, Massimiliano; Nevens, Frederik; van Grunsven, Leo A.; Trebicka, Jonel; Laleman, Wim

2016-01-01

Hepatic inflammation drives hepatic stellate cells (HSC), resulting in liver fibrosis. The Farnesoid-X receptor (FXR) antagonizes inflammation through NF-κB inhibition. We investigated preventive and therapeutic effects of FXR agonist obeticholic acid (OCA) on hepatic inflammation and fibrosis in toxic cirrhotic rats. Cirrhosis was induced by thioacetamide (TAA) intoxication. OCA was given during or after intoxication with vehicle-treated rats as controls. At sacrifice, fibrosis, hemodynamic and biochemical parameters were assessed. HSC activation, cell turn-over, hepatic NF-κB activation, pro-inflammatory and pro-fibrotic cytokines were determined. The effect of OCA was further evaluated in isolated HSC, Kupffer cells, hepatocytes and liver sinusoidal endothelial cells (LSEC). OCA decreased hepatic inflammation and fibrogenesis during TAA-administration and reversed fibrosis in established cirrhosis. Portal pressure decreased through reduced intrahepatic vascular resistance. This was paralleled by decreased expression of pro-fibrotic cytokines (transforming growth-factor β, connective tissue growth factor, platelet-derived growth factor β-receptor) as well as markers of hepatic cell turn-over, by blunting effects of pro-inflammatory cytokines (e.g. monocyte chemo-attractant protein-1). In vitro, OCA inhibited both LSEC and Kupffer cell activation; while HSC remained unaffected. This related to NF-κB inhibition via up-regulated IκBα. In conclusion, OCA inhibits hepatic inflammation in toxic cirrhotic rats resulting in decreased HSC activation and fibrosis. PMID:27634375

SIRT1 antagonizes liver fibrosis by blocking hepatic stellate cell activation in mice.

PubMed

Li, Min; Hong, Wenxuan; Hao, Chenzhi; Li, Luyang; Wu, Dongmei; Shen, Aiguo; Lu, Jun; Zheng, Yuanlin; Li, Ping; Xu, Yong

2018-01-01

Hepatic stellate cells (HSCs) are a major source of fibrogenesis in the liver, contributing to cirrhosis. When activated, HSCs transdifferentiate into myofibroblasts and undergo profound functional alterations paralleling an overhaul of the transcriptome, the mechanism of which remains largely undefined. We investigated the involvement of the class III deacetylase sirtuin [silent information regulator 1 (SIRT1)] in HSC activation and liver fibrosis. SIRT1 levels were down-regulated in the livers in mouse models of liver fibrosis, in patients with cirrhosis, and in activated HSCs as opposed to quiescent HSCs. SIRT1 activation halted, whereas SIRT1 inhibition promoted, HSC transdifferentiation into myofibroblasts. Liver fibrosis was exacerbated in mice with HSC-specific deletion of SIRT1 [conditional knockout (cKO)], receiving CCl 4 (1 mg/kg) injection or subjected to bile duct ligation, compared to wild-type littermates. SIRT1 regulated peroxisome proliferator activated receptor γ (PPARγ) transcription by deacetylating enhancer of zeste homolog 2 (EZH2) in quiescent HSCs. Finally, EZH2 inhibition or PPARγ activation ameliorated fibrogenesis in cKO mice. In summary, our data suggest that SIRT1 plays an essential role guiding the transition of HSC phenotypes.-Li, M., Hong, W., Hao, C., Li, L., Wu, D., Shen, A., Lu, J., Zheng, Y., Li, P., Xu, Y. SIRT1 antagonizes liver fibrosis by blocking hepatic stellate cell activation in mice. © FASEB.

Glutathione and antioxidant enzymes serve complementary roles in protecting activated hepatic stellate cells against hydrogen peroxide-induced cell death.

PubMed

Dunning, Sandra; Ur Rehman, Atta; Tiebosch, Marjolein H; Hannivoort, Rebekka A; Haijer, Floris W; Woudenberg, Jannes; van den Heuvel, Fiona A J; Buist-Homan, Manon; Faber, Klaas Nico; Moshage, Han

2013-12-01

In chronic liver disease, hepatic stellate cells (HSCs) are activated, highly proliferative and produce excessive amounts of extracellular matrix, leading to liver fibrosis. Elevated levels of toxic reactive oxygen species (ROS) produced during chronic liver injury have been implicated in this activation process. Therefore, activated hepatic stellate cells need to harbor highly effective anti-oxidants to protect against the toxic effects of ROS. To investigate the protective mechanisms of activated HSCs against ROS-induced toxicity. Culture-activated rat HSCs were exposed to hydrogen peroxide. Necrosis and apoptosis were determined by Sytox Green or acridine orange staining, respectively. The hydrogen peroxide detoxifying enzymes catalase and glutathione-peroxidase (GPx) were inhibited using 3-amino-1,2,4-triazole and mercaptosuccinic acid, respectively. The anti-oxidant glutathione was depleted by L-buthionine-sulfoximine and repleted with the GSH-analogue GSH-monoethylester (GSH-MEE). Upon activation, HSCs increase their cellular glutathione content and GPx expression, while MnSOD (both at mRNA and protein level) and catalase (at the protein level, but not at the mRNA level) decreased. Hydrogen peroxide did not induce cell death in activated HSCs. Glutathione depletion increased the sensitivity of HSCs to hydrogen peroxide, resulting in 35% and 75% necrotic cells at 0.2 and 1mmol/L hydrogen peroxide, respectively. The sensitizing effect was abolished by GSH-MEE. Inhibition of catalase or GPx significantly increased hydrogen peroxide-induced apoptosis, which was not reversed by GSH-MEE. Activated HSCs have increased ROS-detoxifying capacity compared to quiescent HSCs. Glutathione levels increase during HSC activation and protect against ROS-induced necrosis, whereas hydrogen peroxide-detoxifying enzymes protect against apoptotic cell death. © 2013.

N1-acetyl substituted pyrrolidine derivative CIP-A5: a novel compound that could ameliorate liver cirrhosis through modulation of hepatic stellate cell activity.

PubMed

Wang, Xiao-Dan; Gao, Zu-Hua; Xue, Xia; Cheng, Yan-Na; Yue, Pan; Fang, Xu-Wen; Qu, Xian-Jun

2011-06-01

(2S,4R)-methyl 1-acetyl-4-(N-(4-bromophenyl)sulfamoyloxy)pyrrolidine-2-carboxylate (CIP-A5) is the N1-acetyl substituted pyrrolidine derivative which was designed against the structure of matrix metalloproteinase (MMP-2) and MMP-9. CIP-A5 has been considered as a candidate compound for treatment of liver cirrhosis. In this study, we evaluated the efficacy of CIP-A5 on the activity of hepatic stellate cells. CIP-A5 prevented the transforming growth factor β (TGF-β)-induced proliferation of hepatic stellate HSC-T6 cells as estimated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. CIP-A5 stimulated MMPs activity as evidenced by an increase of degradation of succinylated gelatin. Gelatin zymography analysis showed that CIP-A5 stimulated the secretion and activity of MMP-2 and MMP-9 in HSC-T6 cells. This stimulatory effect on MMPs was verified by the observation of increased expression of MMP-2 and MMP-9 as evaluated by Western blot assay. At the same time, a significant decrease of the expression of tissue inhibitors of matrix metalloproteinases-1 (TIMP-1) was observed, suggesting a modulation of the balance of MMPs/TIMPs in hepatic stellate cells. CIP-A5 treatment also resulted in suppression of the profibrogenic cytokines, such as TGF-β, tumor necrosis factor alpha (TNF-α) and connective tissue growth factor (CTGF) in HSC-T6 cells. CIP-A5 did not have cytotoxicity to human normal hepatic cells. These results implied that CIP-A5 could selectively ameliorate the process of liver cirrhosis through modulation of activated hepatic stellate cell activity, which offers hope for prevention and treatment of this devastating end-stage liver disease. Copyright © 2011 Elsevier Ltd. All rights reserved.

Pirfenidone inhibits proliferation, arrests the cell cycle, and downregulates heat shock protein-47 and collagen type I in rat hepatic stellate cells in vitro.

PubMed

Xiang, Xian-Hong; Jiang, Tian-Peng; Zhang, Shuai; Song, Jie; Li, Xing; Yang, Jian-Yong; Zhou, Shi

2015-07-01

Pirfenidone (esbiret) is an established anti-fibrotic and anti-inflammatory drug used to treat idiopathic pulmonary fibrosis. In the present study, the dose-dependent effects of pirfenidone on the cell cycle, proliferation and expression of heat shock protein (HSP)-47 and collagen type I in a cultured rat hepatic stellate cell line (HSC-T6) were investigated. Following pirfenidone treatment, cell proliferation was determined using the cell counting kit-8 assay and the cell cycle was measured using flow cytometry. HSP-47 expression was estimated using western blot analysis and collagen type I mRNA was assessed using reverse transcription quantitative polymerase chain reaction. Pirfenidone induced significant dose-dependent inhibition of proliferation in HSC-T6 cells. Cell viability was unaffected by treatment with pirfenidone (0, 10 or 100 µM) for 24 and 72 h. However, after 24 h, HSC-T6 cells exhibited dose-dependent decreases in HSP-47 protein and collagen I mRNA levels. In conclusion, pirfenidone inhibited HSC-T6 cell proliferation, arrested the cell cycle and reduced the expression of HSP-47 and collagen type I, indicating that pirfenidone may be a promising drug in the treatment of liver fibrosis.

OPC-13013, a cyclic nucleotide phosphodiesterase type III, inhibitor, inhibits cell proliferation and transdifferentiation of cultured rat hepatic stellate cells.

PubMed

Shimizu, E; Kobayashi, Y; Oki, Y; Kawasaki, T; Yoshimi, T; Nakamura, H

1999-01-01

Activated hepatic stellate cells (HSC; lipocytes; Ito cells) proliferate and are responsible for extracellular matrix synthesis during hepatic fibrogenesis. During activation, HSC undergo transdifferentiation into myofibroblasts expressing alpha-smooth muscle actin (alpha-SMA). Adenosine 3', 5'-cyclic monophosphate (cyclic AMP) is an ubiquitous intracellular signaling molecule, and is upregulated by the activation of adenylate cyclase and downregulated via hydrolysis by cyclic nucleotide phosphodiesterases (PDEs). Recently, increased intracellular cyclic AMP has been shown to inhibit HSC activation. The aim of the current study was to determine the effects of inhibition of PDEs on cell proliferation and transdifferentiation in cultured rat HSC. Cell proliferation was determined by [3H]thymidine incorporation, and Western blot analysis was performed for detection of alpha-SMA, a phenotypic marker of transdifferentiation into myofibroblast. When the cells were exposed to 3-isobutyl-1-methylxanthine (IBMX; 50-1000 microM), a nonselective PDE inhibitor, serum-stimulated [3H]thymidine incorporation was suppressed in a dose-dependent manner with a maximum inhibition of 66% at a concentration of 500 microM OPC-13013 (1-60 microM), a selective PDE III isoenzyme inhibitor, induced a dose-dependent inhibitory effect on serum-stimulated DNA synthesis that reached a maximum inhibition of 95% at a concentration of 60 microM, while neither 8-methoxymethyl-3-isobutyl-1-methylxanthine (8-MMX), a PDE I isoenzyme inhibitor, nor Ro-20-1724, a PDE IV isoenzyme inhibitor, had an inhibitory effect. Western blot analysis revealed that IBMX or OPC-13013 decreased alpha-SMA expression, while other selective PDE isoenzyme inhibitors did not have a suppressive effect. IBMX, OPC-13013 or Ro-20-1724, but not 8-MMX augmented forskolin-induced increase in intracellular cyclic AMP levels although cyclic AMP levels were not affected by treatment with any of these PDE inhibitors alone. These data

Establishment of a novel collagenase perfusion method to isolate rat pancreatic stellate cells and investigation of their gene expression of TGF-beta1, type I collagen, and CTGF in primary culture or freshly isolated cells.

PubMed

Shinji, Toshiyuki; Ujike, Kozo; Ochi, Koji; Kusano, Nobuchika; Kikui, Tetsuya; Matsumura, Naoki; Emori, Yasuyuki; Seno, Toshinobu; Koide, Norio

2002-08-01

In studies of the pathogenesis of pancreatic fibrosis, pancreatic stellate cells (PSCs) have recently gained attention. In the present study, we established a new collagenase perfusion method through thoracic aorta cannulation to isolate PSCs, and we studied gene expression of TGF-beta1, type I collagen, and connective tissue growth factor using primary cultured PSCs. Our method facilitated PSC isolation, and by our new method, 4.3 +/- 1.2 x 10(6) PSCs were obtained from a rat. In comparing the expression of these genes with that of hepatic stellate cells (HSCs), we observed a similar pattern, although PSCs expressed type I collagen gene earlier than did HSCs. These results suggest that PSCs may play an important role in fibrosis of the pancreas, as HSCs do in liver fibrosis; in addition, PSCs may exist in a preactivated state or may be more easily activated than are HSCs. We also isolated the PSCs from a WBN/Kob rat, the spontaneous pancreatitis rat, and compared the gene expression with that from a normal rat.

The antifibrotic effects of TGF-{beta}1 siRNA on hepatic fibrosis in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lang, Qing; Liu, Qi; Xu, Ning

2011-06-10

Highlights: {yields} We constructed CCL4 induced liver fibrosis model successfully. {yields} We proofed that the TGF-{beta}1 siRNA had a definite therapy effect to CCL4 induced liver fibrosis. {yields} The therapy effect of TGF-{beta}1 siRNA had dose-dependent. -- Abstract: Background/aims: Hepatic fibrosis results from the excessive secretion of matrix proteins by hepatic stellate cells (HSCs), which proliferate during fibrotic liver injury. Transforming growth factor (TGF)-{beta}1 is the dominant stimulus for extracellular matrix (ECM) production by stellate cells. Our study was designed to investigate the antifibrotic effects of using short interference RNA (siRNA) to target TGF-{beta}1 in hepatic fibrosis and its mechanismmore » in rats exposed to a high-fat diet and carbon tetrachloride (CCL4). Methods: A total of 40 healthy, male SD (Sprague-Dawley) rats were randomly divided into five even groups containing of eight rats each: normal group, model group, TGF-{beta}1 siRNA 0.125 mg/kg treatment group, TGF-{beta}1 siRNA 0.25 mg/kg treatment group and TGF-{beta}1 siRNA negative control group (0.25 mg/kg). CCL4 and a high-fat diet were used for 8 weeks to induce hepatic fibrosis. All the rats were then sacrificed to collect liver tissue samples. A portion of the liver samples were soaked in formalin for Hematoxylin-Eosin staining, classifying the degree of liver fibrosis, and detecting the expression of type I and III collagen and TGF-{beta}1; the remaining liver samples were stored in liquid nitrogen to be used for detecting TGF-{beta}1 by Western blotting and for measuring the mRNA expression of type I and III collagen and TGF-{beta}1 by quantitative real-time polymerase chain reaction. Results: Comparing the TGF-{beta}1 siRNA 0.25 mg/kg treatment group to the model group, the TGF-{beta}1 siRNA negative control group and the TGF-{beta}1 siRNA 0.125 mg/kg treatment group showed significantly reduced levels of pathological changes, protein expression and the m

Stiffening hydrogels for investigating the dynamics of hepatic stellate cell mechanotransduction during myofibroblast activation

NASA Astrophysics Data System (ADS)

Caliari, Steven R.; Perepelyuk, Maryna; Cosgrove, Brian D.; Tsai, Shannon J.; Lee, Gi Yun; Mauck, Robert L.; Wells, Rebecca G.; Burdick, Jason A.

2016-02-01

Tissue fibrosis contributes to nearly half of all deaths in the developed world and is characterized by progressive matrix stiffening. Despite this, nearly all in vitro disease models are mechanically static. Here, we used visible light-mediated stiffening hydrogels to investigate cell mechanotransduction in a disease-relevant system. Primary hepatic stellate cell-seeded hydrogels stiffened in situ at later time points (following a recovery phase post-isolation) displayed accelerated signaling kinetics of both early (Yes-associated protein/Transcriptional coactivator with PDZ-binding motif, YAP/TAZ) and late (alpha-smooth muscle actin, α-SMA) markers of myofibroblast differentiation, resulting in a time course similar to observed in vivo activation dynamics. We further validated this system by showing that α-SMA inhibition following substrate stiffening resulted in attenuated stellate cell activation, with reduced YAP/TAZ nuclear shuttling and traction force generation. Together, these data suggest that stiffening hydrogels may be more faithful models for studying myofibroblast activation than static substrates and could inform the development of disease therapeutics.

Long live the liver: immunohistochemical and stereological study of hepatocytes, liver sinusoidal endothelial cells, Kupffer cells and hepatic stellate cells of male and female rats throughout ageing.

PubMed

Marcos, Ricardo; Correia-Gomes, Carla

2016-12-01

Male/female differences in enzyme activity and gene expression in the liver are known to be attenuated with ageing. Nevertheless, the effect of ageing on liver structure and quantitative cell morphology remains unknown. Male and female Wistar rats aged 2, 6, 12 and 18 months were examined by means of stereological techniques and immunohistochemical tagging of hepatocytes (HEP), liver sinusoidal endothelial cells (LSEC), Kupffer cells (KC) and hepatic stellate cells (HSC) in order to assess the total number and number per gram of these cells throughout life. The mean cell volume of HEP and HSC, the lobular position and the collagen content of the liver were also evaluated with stereological techniques. The number per gram of HSC was similar for both genders and was maintained throughout ageing. The mean volume of HSC was also conserved but differences in the cell body and lobular location were observed. Statistically significant gender differences in HEP were noted in young rats (females had smaller and more binucleated HEP) but were attenuated with ageing. The same occurred for KC and LSEC, since the higher number per gram in young females disappeared in older animals. Liver collagen increased with ageing but only in males. Thus, the numbers of these four cell types are related throughout ageing, with well-defined cell ratios. The shape and lobular position of HSC change with ageing in both males and females. Gender dimorphism in HEP, KC and LSEC of young rat liver disappears with ageing.

The let-7/Lin28 axis regulates activation of hepatic stellate cells in alcoholic liver injury.

PubMed

McDaniel, Kelly; Huang, Li; Sato, Keisaku; Wu, Nan; Annable, Tami; Zhou, Tianhao; Ramos-Lorenzo, Sugeily; Wan, Ying; Huang, Qiaobing; Francis, Heather; Glaser, Shannon; Tsukamoto, Hidekazu; Alpini, Gianfranco; Meng, Fanyin

2017-07-07

The let-7/Lin28 axis is associated with the regulation of key cellular regulatory genes known as microRNAs in various human disorders and cancer development. This study evaluated the role of the let-7/Lin28 axis in regulating a mesenchymal phenotype of hepatic stellate cells in alcoholic liver injury. We identified that ethanol feeding significantly down-regulated several members of the let-7 family in mouse liver, including let-7a and let-7b. Similarly, the treatment of human hepatic stellate cells (HSCs) with lipopolysaccharide (LPS) and transforming growth factor-β (TGF-β) significantly decreased the expressions of let-7a and let-7b. Conversely, overexpression of let-7a and let-7b suppressed the myofibroblastic activation of cultured human HSCs induced by LPS and TGF-β, as evidenced by repressed ACTA2 (α-actin 2), COL1A1 (collagen 1A1), TIMP1 (TIMP metallopeptidase inhibitor 1), and FN1 (fibronectin 1); this supports the notion that HSC activation is controlled by let-7. A combination of bioinformatics, dual-luciferase reporter assay, and Western blot analysis revealed that Lin28B and high-mobility group AT-hook (HMGA2) were the direct targets of let-7a and let-7b. Furthermore, Lin28B deficiency increased the expression of let-7a/let-7b as well as reduced HSC activation and liver fibrosis in mice with alcoholic liver injury. This feedback regulation of let-7 by Lin28B is verified in hepatic stellate cells isolated by laser capture microdissection from the model. The identification of the let-7/Lin28 axis as an important regulator of HSC activation as well as its upstream modulators and down-stream targets will provide insights into the involvement of altered microRNA expression in contributing to the pathogenesis of alcoholic liver fibrosis and novel therapeutic approaches for human alcoholic liver diseases. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Changes in Inward Rectifier K+ Channels in Hepatic Stellate Cells During Primary Culture

PubMed Central

Lee, Dong Hyeon; Kong, In Deok; Lee, Joong-Woo

2008-01-01

Purpose This study examined the expression and function of inward rectifier K+ channels in cultured rat hepatic stellate cells (HSC). Materials and Methods The expression of inward rectifier K+ channels was measured using real-time RT-PCR, and electrophysiological properties were determined using the gramicidin-perforated patch-clamp technique. Results The dominant inward rectifier K+ channel subtypes were Kir2.1 and Kir6.1. These dominant K+ channel subtypes decreased significantly during the primary culture throughout activation process. HSC can be classified into two subgroups: one with an inward-rectifying K+ current (type 1) and the other without (type 2). The inward current was blocked by Ba2+ (100 µM) and enhanced by high K+ (140 mM), more prominently in type 1 HSC. There was a correlation between the amplitude of the Ba2+-sensitive current and the membrane potential. In addition, Ba2+ (300 µM) depolarized the membrane potential. After the culture period, the amplitude of the inward current decreased and the membrane potential became depolarized. Conclusion HSC express inward rectifier K+ channels, which physiologically regulate membrane potential and decrease during the activation process. These results will potentially help determine properties of the inward rectifier K+ channels in HSC as well as their roles in the activation process. PMID:18581597

PHP14 regulates hepatic stellate cells migration in liver fibrosis via mediating TGF-β1 signaling to PI3Kγ/AKT/Rac1 pathway.

PubMed

Xu, Anjian; Li, Yanmeng; Zhao, Wenshan; Hou, Fei; Li, Xiaojin; Sun, Lan; Chen, Wei; Yang, Aiting; Wu, Shanna; Zhang, Bei; Yao, Jingyi; Wang, Huan; Huang, Jian

2018-02-01

Hepatic fibrosis is characterized by the activation of hepatic stellate cells (HSCs). Migration of the activated HSCs to the site of injury is one of the key characteristics during the wound healing process. We have previously demonstrated that 14 kDa phosphohistidine phosphatase (PHP14) is involved in migration and lamellipodia formation of HSCs. However, the role of PHP14 in liver fibrosis remains unknown. In this study, we first assessed PHP14 expression and distribution in liver fibrotic tissues using western blot, immunohistochemistry, and double immunofluorescence staining. Next, we investigated the role of PHP14 in liver fibrosis and, more specifically, the migration of HSCs by Transwell assay and 3D collagen matrices assay. Finally, we explored the possible molecular mechanisms of the effects of PHP14 on these processes. Our results show that the PHP14 expression is up-regulated in fibrotic liver and mainly in HSCs. Importantly, TGF-β1 can induce PHP14 expression in HSCs accompanied with the activation of HSCs. Consistent with the previous study, PHP14 promotes HSCs migration, especially, promotes 3D floating collagen matrices contraction but inhibits stressed-released matrices contraction. Mechanistically, the PI3Kγ/AKT/Rac1 pathway is involved in migration regulated by PHP14. Moreover, PHP14 specifically mediates the TGF-β1 signaling to PI3Kγ/AKT pathway and regulates HSC migration, and thus participates in liver fibrosis. Our study identified the role of PHP14 in liver fibrosis, particularly HSC migration, and suggested a novel mediator of transducting TGF-β1 signaling to PI3Kγ/AKT/Rac1 pathway. PHP14 is up-regulated in fibrotic liver and activated hepatic stellate cells. The expression of PHP14 is induced by TGF-β1. The migration of hepatic stellate cells is regulated by PHP14. PHP14 is a mediator of TGF-β1 signaling to PI3Kγ/AKT/Rac1 pathway in hepatic stellate cells.

Alteration of pancreatic carcinoma and promyeloblastic cell adhesion in liver microvasculature by co-culture of hepatocytes, hepatic stellate cells and endothelial cells in a physiologically-relevant model.

PubMed

Danoy, Mathieu; Shinohara, Marie; Rizki-Safitri, Astia; Collard, Dominique; Senez, Vincent; Sakai, Yasuyuki

2017-04-18

In vitro models of the liver microvasculature, especially with respect to cancer cell extravasation, should include not only endothelial and cancer cells but also surrounding cells to mimic the physiological situation. To this end, in the present study, we established a physiologically-relevant hierarchical co-culture model by stacking layers of primary rat hepatocytes (Hep), hepatic stellate cells embedded in collagen gel (LX-2) and endothelial cells (HUVECs) on a specially designed oxygen-permeable polydimethylsiloxane PDMS bottom plate. The model was used to investigate the role and contribution of each of the three cell types in pancreatic cancer and promyeloblast cell adhesion. In particular, we showed an increase in albumin production by the primary hepatocytes and in the consumption of the produced vascular endothelial growth factors (VEGFs). Furthermore, in co-culture, the HUVECs exhibited a mature vascular endothelial and non-inflamed phenotype, as evidenced by Stabilin-1, lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), intercellular adhesion molecule (ICAM-1), and vascular adhesion protein-1 (VAP-1) expression. The HUVECs were also successfully activated with an inflammatory cytokine and their ICAM-1 response was found to be higher in monoculture compared to co-culture. Additionally, the adhesion of MiaPaCa-2 pancreatic cancer cells and HL60 promyeloblasts was tested in both cases (i.e.: activation or not by an inflammatory cytokine). It has been found that their adhesion was always reduced in the co-culture model. These results highlight the importance of integrating hepatic stellate cells in the design of biomimetic models of the hepatic endothelial barrier.

Activated hepatic stellate cells are dependent on self-collagen, cleaved by membrane type 1 matrix metalloproteinase for their growth.

PubMed

Birukawa, Naoko Kubo; Murase, Kazuyuki; Sato, Yasushi; Kosaka, Akemi; Yoneda, Akihiro; Nishita, Hiroki; Fujita, Ryosuke; Nishimura, Miyuki; Ninomiya, Takafumi; Kajiwara, Keiko; Miyazaki, Miyono; Nakashima, Yusuke; Ota, Sigenori; Murakami, Yuya; Tanaka, Yasunobu; Minomi, Kenjiro; Tamura, Yasuaki; Niitsu, Yoshiro

2014-07-18

Stellate cells are distributed throughout organs, where, upon chronic damage, they become activated and proliferate to secrete collagen, which results in organ fibrosis. An intriguing property of hepatic stellate cells (HSCs) is that they undergo apoptosis when collagen is resolved by stopping tissue damage or by treatment, even though the mechanisms are unknown. Here we disclose the fact that HSCs, normal diploid cells, acquired dependence on collagen for their growth during the transition from quiescent to active states. The intramolecular RGD motifs of collagen were exposed by cleavage with their own membrane type 1 matrix metalloproteinase (MT1-MMP). The following evidence supports this conclusion. When rat activated HSCs (aHSCs) were transduced with siRNA against the collagen-specific chaperone gp46 to inhibit collagen secretion, the cells underwent autophagy followed by apoptosis. Concomitantly, the growth of aHSCs was suppressed, whereas that of quiescent HSCs was not. These in vitro results are compatible with the in vivo observation that apoptosis of aHSCs was induced in cirrhotic livers of rats treated with siRNAgp46. siRNA against MT1-MMP and addition of tissue inhibitor of metalloproteinase 2 (TIMP-2), which mainly inhibits MT1-MMP, also significantly suppressed the growth of aHSCs in vitro. The RGD inhibitors echistatin and GRGDS peptide and siRNA against the RGD receptor αVβ1 resulted in the inhibition of aHSCs growth. Transduction of siRNAs against gp46, αVβ1, and MT1-MMP to aHSCs inhibited the survival signal of PI3K/AKT/IκB. These results could provide novel antifibrosis strategies. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Inhibitory effect of OPC-15161, a component of fungus Thielavia minor, on proliferation and extracellular matrix production of rat cultured hepatic stellate cells.

PubMed

Sugawara, H; Ueno, T; Torimura, T; Inuzuka, S; Tanikawa, K

1998-03-01

A component of fungus Thielavia minor, OPC-15161, has been shown to inhibit the proliferation and extracellular matrix production of extracellular matrix-producing mesangial cells in the kidney in vivo. In this study, we examined the effects of OPC-15161 on the proliferation and extracellular matrix production of rat cultured hepatic stellate cells (HSCs). To determine the effect of OPC-15161 on proliferation of HSCs, the cell number and the uptake of [3H]thymidine were investigated in the presence and absence of interleukin-1beta (IL-1beta). IL-1beta significantly increased the uptake of [3H]thymidine in the HSCs, and the addition of OPC-15161 inhibited the uptake in a dose-dependent manner. The cell number of HSCs was also increased by IL-1beta, which was inhibited by OPC-15161. Production of extracellular matrix by OPC-15161 was studied by the production of [3H]-hydroxyproline in the presence and absence of transforming growth factor-beta1 (TGF-beta1). TGF-beta1 significantly increased the production of [3H]-hydroxyproline in the cells, whereas the addition of OPC-15161 inhibited this effect dose dependently. We also investigated the effects of OPC-15161 on Ca2+ mobilization and measured D-myo-inositol 1,4,5-triphosphate (IP3) in the HSCs. IL-1beta induced the increase of intracellular Ca2+ and IP3 concentrations in the HSCs, which were decreased by OPC-15161. Based on these results, we conclude that OPC-1 5161 inhibited the proliferation and production of hydroxyproline in cultured rat HSCs, and thus, it may have a role in prevention of liver fibrosis in vivo.

Over-expression of C/EBP-{alpha} induces apoptosis in cultured rat hepatic stellate cells depending on p53 and peroxisome proliferator-activated receptor-{gamma}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Xueqing; Huang Guangcun; Mei Shuang

2009-03-06

Hepatic stellate cells (HSCs) play a key role in the pathogenesis of hepatic fibrosis. In our previous studies, CCAAT enhancer binding protein-{alpha} (C/EBP-{alpha}) has been shown to be involved in the activation of HSCs and to have a repression effect on hepatic fibrosis in vivo. However, the mechanisms are largely unknown. In this study, we show that the infection of adenovirus vector expressing C/EBP-{alpha} gene (Ad-C/EBP-{alpha}) could induce HSCs apoptosis in a dose- and time-dependent manner by Annexin V/PI staining, caspase-3 activation assay, and flow cytometry. Also, over-expression of C/EBP-{alpha} resulted in the up-regulation of peroxisome proliferator-activated receptor-{gamma} (PPAR-{gamma}) andmore » P53, while P53 expression was regulated by PPAR-{gamma}. In addition, Fas, FasL, DR4, DR5, and TRAIL were studied. The results indicated that the death receptor pathway was mainly involved and regulated by PPAR-{gamma} and p53 in the process of apoptosis triggered by C/EBP-{alpha} in HSCs.« less

Corona-directed nucleic acid delivery into hepatic stellate cells for liver fibrosis therapy.

PubMed

Zhang, Zhengping; Wang, Chunming; Zha, Yinhe; Hu, Wei; Gao, Zhongfei; Zang, Yuhui; Chen, Jiangning; Zhang, Junfeng; Dong, Lei

2015-03-24

Strategies to modify nanoparticles with biological ligands for targeted drug delivery in vivo have been widely studied but met with limited clinical success. A possible reason is that, in the blood circulation, serum proteins could rapidly form a layer of protein "corona" on the vehicle surface, which might block the modified ligands and hamper their targeting functions. We speculate that strategies for drug delivery can be designed based upon elegant control of the corona formation on the vehicle surfaces. In this study, we demonstrate a retinol-conjugated polyetherimine (RcP) nanoparticle system that selectively recruited the retinol binding protein 4 (RBP) in its corona components. RBP was found to bind retinol, and direct the antisense oligonucleotide (ASO)-laden RcP carrier to hepatic stellate cells (HSC), which play essential roles in the progression of hepatic fibrosis. In both mouse fibrosis models, induced by carbon tetrachloride (CCl4) and bile duct ligation (BDL), respectively, the ASO-laden RcP particles effectively suppressed the expression of type I collagen (collagen I), and consequently ameliorated hepatic fibrosis. Such findings suggest that this delivery system, designed to exploit the power of corona proteins, can serve as a promising tool for targeted delivery of therapeutic agents for the treatment of hepatic fibrosis.

Substance P increases liver fibrosis by differential changes in senescence of cholangiocytes and hepatic stellate cells.

PubMed

Wan, Ying; Meng, Fanyin; Wu, Nan; Zhou, Tianhao; Venter, Julie; Francis, Heather; Kennedy, Lindsey; Glaser, Trenton; Bernuzzi, Francesca; Invernizzi, Pietro; Glaser, Shannon; Huang, Qiaobing; Alpini, Gianfranco

2017-08-01

Substance P (SP) is involved in the proliferation of cholangiocytes in bile duct-ligated (BDL) mice and human cholangiocarcinoma growth by interacting with the neurokinin-1 receptor (NK-1R). To identify whether SP regulates liver fibrosis during cholestasis, wild-type or NK-1R knockout (NK-1R -/- ) mice that received BDL or sham surgery and multidrug resistance protein 2 knockout (Mdr2 -/- ) mice treated with either an NK-1R antagonist (L-733,060) or saline were used. Additionally, wild-type mice were treated with SP or saline intraperitoneally. In vivo, there was increased expression of tachykinin precursor 1 (coding SP) and NK-1R in both BDL and Mdr2 -/- mice compared to wild-type mice. Expression of tachykinin precursor 1 and NK-1R was significantly higher in liver samples from primary sclerosing cholangitis patients compared to healthy controls. Knockout of NK-1R decreased BDL-induced liver fibrosis, and treatment with L-733,060 resulted in decreased liver fibrosis in Mdr2 -/- mice, which was shown by decreased sirius red staining, fibrosis gene and protein expression, and reduced transforming growth factor-β1 levels in serum and cholangiocyte supernatants. Furthermore, we observed that reduced liver fibrosis in NK-1R -/- mice with BDL surgery or Mdr2 -/- mice treated with L-733,060 was associated with enhanced cellular senescence of hepatic stellate cells and decreased senescence of cholangiocytes. In vitro, L-733,060 inhibited SP-induced expression of fibrotic genes in hepatic stellate cells and cholangiocytes; treatment with L-733,060 partially reversed the SP-induced decrease of senescence gene expression in cultured hepatic stellate cells and the SP-induced increase of senescence-related gene expression in cultured cholangiocytes. Collectively, our results demonstrate the regulatory effects of the SP/NK-1R axis on liver fibrosis through changes in cellular senescence during cholestatic liver injury. (Hepatology 2017;66:528-541). © 2017 by the American

Carvedilol Improves Inflammatory Response, Oxidative Stress and Fibrosis in the Alcohol-Induced Liver Injury in Rats by Regulating Kuppfer Cells and Hepatic Stellate Cells

PubMed Central

Leitão, Renata Ferreira de Carvalho; Brito, Gerly Anne de Castro; Miguel, Emilio de Castro; Guedes, Paulo Marcos Matta; de Araújo, Aurigena Antunes

2016-01-01

-α, procollagen type I (PCI), procollagen type III (PCIII), and NF-κB were decreased in the alcohol-CARV 5 mg/kg group relative to the alcohol-only group. Conclusions CARV can reduce the stress oxidative, inflammatory response and fibrosis in ethanol-induced liver injury in a rat model by downregulating signalling of Kuppfer cells and hepatic stellate cells (HSCs) through suppression of inflammatory cytokines. PMID:26891124

Cannabidiol causes activated hepatic stellate cell death through a mechanism of endoplasmic reticulum stress-induced apoptosis

PubMed Central

Lim, M P; Devi, L A; Rozenfeld, R

2011-01-01

The major cellular event in the development and progression of liver fibrosis is the activation of hepatic stellate cells (HSCs). Activated HSCs proliferate and produce excess collagen, leading to accumulation of scar matrix and fibrotic liver. As such, the induction of activated HSC death has been proposed as a means to achieve resolution of liver fibrosis. Here we demonstrate that cannabidiol (CBD), a major non-psychoactive component of the plant Cannabis sativa, induces apoptosis in activated HSCs through a cannabinoid receptor-independent mechanism. CBD elicits an endoplasmic reticulum (ER) stress response, characterized by changes in ER morphology and the initiation of RNA-dependent protein kinase-like ER kinase-, activating transcription factor-6-, and inositol-requiring ER-to-nucleus signal kinase-1 (IRE1)-mediated signaling cascades. Furthermore, CBD induces downstream activation of the pro-apoptotic IRE1/ASK1/c-Jun N-terminal kinase pathway, leading to HSC death. Importantly, we show that this mechanism of CBD-induced ER stress-mediated apoptosis is specific to activated HSCs, as it occurs in activated human and rat HSC lines, and in primary in vivo-activated mouse HSCs, but not in quiescent HSCs or primary hepatocytes from rat. Finally, we provide evidence that the elevated basal level of ER stress in activated HSCs has a role in their susceptibility to the pro-apoptotic effect of CBD. We propose that CBD, by selectively inducing death of activated HSCs, represents a potential therapeutic agent for the treatment of liver fibrosis. PMID:21654828

Stellate-cell lipidosis in liver biopsy specimens. Recognition and significance.

PubMed

Levine, Pascale Hummel; Delgado, Yara; Theise, Neil D; West, A Brian

2003-02-01

Hepatic stellate-cell lipidosis due to hypervitaminosis A can lead to cirrhosis, which can be averted by restricting vitamin A intake. Other causes, including the use of synthetic retinoids, have been postulated. We studied the frequency and etiology of stellate-cell lipidosis in patients undergoing liver biopsy for reasons other than vitamin A abuse. Fourteen cases (1.1%) were identified retrospectively among 1,235 nontransplant liver biopsy specimens examined from January 1995 through December 1999. Diagnostic criteria included the following: lipid-laden cells in the space of Disse; small, dark, crescent-shaped nuclei with inconspicuous nucleoli; and wispy cytoplasmic strands separating fat droplets. Patient details, reason for biopsy, and medication use were studied. Reasons for biopsy included hepatitis C (10 cases), abnormal liver enzyme levels (2 cases), methotrexate use (1 case), and alcohol abuse (1 case). Hypervitaminosis A was not suspected clinically in the 5 patients who used oral vitamin A or 3 who used topical tretinoin (Retin-A). In 6 patients, no cause of stellate-cell lipidosis was discerned. Stellate-cell lipidosis should be reported to alert clinicians to a potentially preventable form of liver injury.

Curcumin inhibits hepatic stellate cell activation via suppression of succinate-associated HIF-1α induction.

PubMed

She, Linlin; Xu, Dan; Wang, Zixia; Zhang, Yirui; Wei, Qingli; Aa, Jiye; Wang, Guangji; Liu, Baolin; Xie, Yuan

2018-05-07

Aberrant succinate accumulation emerges as a unifying mechanism for inflammation and oxidative stress. This study aims to investigate whether curcumin ameliorates hepatic fibrosis via blocking succinate signaling. We investigated the effects of curcumin on hepatic succinate accumulation and liver fibrosis in mice fed a high-fat diet (HFD). Meanwhile, we stimulated mouse primary hepatic stellate cells (HSCs) with succinate and observed the inhibitory effects of curcumin on succinate signaling. Oral administration of curcumin and metformin combated mitochondrial fatty acid oxidation and reduced hepatic succinate accumulation due to the inhibition of succinate dehydrogenase (SDH) activity and demonstrated inhibitory effect on hepatic fibrosis. In mouse primary HSCs, curcumin prevented succinate- and CoCl 2 -induced hypoxia-inducible transcription factor-1α (HIF-1α) induction via suppression of ROS production and effectively reduced gene expressions of Col1α, Col3α, fibronectin and TGF-β1 with inflammation inhibition. Knockdown of HIF-1α with small interfering RNA blocked the action of succinate to induce HSCs activation, indicative of the essential role of HIF-1α in succinate signaling. Hepatic succinate accumulation served as a metabolic signal to promote liver fibrosis through HIF-1α induction. Curcumin reduced succinate accumulation by combating fatty acid oxidation and prevented HSCs activation by blocking succinate/HIF-1α signaling pathway. Copyright © 2018. Published by Elsevier B.V.

Interferon gamma peptidomimetic targeted to hepatic stellate cells ameliorates acute and chronic liver fibrosis in vivo.

PubMed

Bansal, Ruchi; Prakash, Jai; De Ruiter, Marieke; Poelstra, Klaas

2014-04-10

Hepatic stellate cells play a crucial role in the pathogenesis of hepatic fibrosis. Thus, pharmacological inhibition of pro-fibrotic activities of these cells might lead to an effective therapy for this disease. Among the potent anti-fibrotics, interferon gamma (IFNγ), a proinflammatory cytokine, is highly efficacious but it failed in clinical trials due to the poor efficacy and multiple adverse effects attributed to the ubiquitous IFNγ receptor (IFNγR) expression. To resolve these drawbacks, we chemically synthesized a chimeric molecule containing (a) IFNγ signaling peptide (IFNγ peptidomimetic, mimγ) that retains the agonistic activities of IFNγ but lacks an extracellular receptor recognition sequence for IFNγR; coupled via heterobifunctional PEG linker to (b) bicyclic platelet derived growth factor beta receptor (PDGFβR)-binding peptide (BiPPB) to induce internalization into the stellate cells that express PDGFβR. The synthesized targeted IFNγ peptidomimetic (mimγ-BiPPB) was extensively investigated for its anti-fibrotic and adverse effects in acute and chronic CCl4-induced liver fibrosis models in mice. Treatment with mimγ-BiPPB, after the onset of disease, markedly inhibited both early and established hepatic fibrosis as reflected by a reduced intrahepatic α-SMA, desmin and collagen-I mRNA expression and protein levels. While untargeted mimγ and BiPPB had no effect, and native IFNγ only induced a moderate reduction. Additionally, no off-target effects, e.g. systemic inflammation, were found with mimγ-BiPPB, which were substantially observed in mice treated with native IFNγ. The present study highlights the beneficial effects of a novel BiPPB mediated cell-specific targeting of IFNγ peptidomimetic to the disease-inducing cells and therefore represents a highly potential therapeutic approach to treat fibrotic diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

Single cell analysis in native tissue: Quantification of the retinoid content of hepatic stellate cells

NASA Astrophysics Data System (ADS)

Galler, Kerstin; Requardt, Robert Pascal; Glaser, Uwe; Markwart, Robby; Bocklitz, Thomas; Bauer, Michael; Popp, Jürgen; Neugebauer, Ute

2016-04-01

Hepatic stellate cells (HSCs) are retinoid storing cells in the liver: The retinoid content of those cells changes depending on nutrition and stress level. There are also differences with regard to a HSC’s anatomical position in the liver. Up to now, retinoid levels were only accessible from bulk measurements of tissue homogenates or cell extracts. Unfortunately, they do not account for the intercellular variability. Herein, Raman spectroscopy relying on excitation by the minimally destructive wavelength 785 nm is introduced for the assessment of the retinoid state of single HSCs in freshly isolated, unprocessed murine liver lobes. A quantitative estimation of the cellular retinoid content is derived. Implications of the retinoid content on hepatic health state are reported. The Raman-based results are integrated with histological assessments of the tissue samples. This spectroscopic approach enables single cell analysis regarding an important cellular feature in unharmed tissue.

Single cell analysis in native tissue: Quantification of the retinoid content of hepatic stellate cells

PubMed Central

Galler, Kerstin; Requardt, Robert Pascal; Glaser, Uwe; Markwart, Robby; Bocklitz, Thomas; Bauer, Michael; Popp, Jürgen; Neugebauer, Ute

2016-01-01

Hepatic stellate cells (HSCs) are retinoid storing cells in the liver: The retinoid content of those cells changes depending on nutrition and stress level. There are also differences with regard to a HSC’s anatomical position in the liver. Up to now, retinoid levels were only accessible from bulk measurements of tissue homogenates or cell extracts. Unfortunately, they do not account for the intercellular variability. Herein, Raman spectroscopy relying on excitation by the minimally destructive wavelength 785 nm is introduced for the assessment of the retinoid state of single HSCs in freshly isolated, unprocessed murine liver lobes. A quantitative estimation of the cellular retinoid content is derived. Implications of the retinoid content on hepatic health state are reported. The Raman-based results are integrated with histological assessments of the tissue samples. This spectroscopic approach enables single cell analysis regarding an important cellular feature in unharmed tissue. PMID:27063397

Dihydroartemisinin alleviates bile duct ligation-induced liver fibrosis and hepatic stellate cell activation by interfering with the PDGF-βR/ERK signaling pathway.

PubMed

Chen, Qin; Chen, Lianyun; Kong, Desong; Shao, Jiangjuan; Wu, Li; Zheng, Shizhong

2016-05-01

Liver fibrosis represents a frequent event following chronic insult to trigger wound healing responses in the liver. Activation of hepatic stellate cells (HSCs), which is a pivotal event during liver fibrogenesis, is accompanied by enhanced expressions of a series of marker proteins and pro-fibrogenic signaling molecules. Artemisinin, a powerful antimalarial medicine, is extracted from the Chinese herb Artemisia annua L., and can inhibit the proliferation of cancer cells. Dihydroartemisinin (DHA), the major active metabolite of artemisinin, is able to attenuate lung injury and fibrosis. However, the effect of DHA on liver fibrosis remains unclear. The aim of this study was to investigate the effect of DHA on bile duct ligation-induced injury and fibrosis in rats. DHA improved the liver histological architecture and attenuated collagen deposition in the fibrotic rat liver. Experiments in vitro showed that DHA inhibited the proliferation of HSCs and arrested the cell cycle at the S checkpoint by altering several cell-cycle regulatory proteins. Moreover, DHA reduced the protein expressions of a-SMA, α1 (I) collagen and fibronectin, being associated with interference of the platelet-derived growth factor β receptor (PDGF-βR)-mediated ERK pathway. These data collectively revealed that DHA relieved liver fibrosis possibly by targeting HSCs via the PDGF-βR/ERK pathway. DHA may be a therapeutic antifibrotic agent for the treatment of hepatic fibrosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Liver X Receptors Balance Lipid Stores in Hepatic Stellate Cells via Rab18, a Retinoid Responsive Lipid Droplet Protein

PubMed Central

O’Mahony, Fiona; Wroblewski, Kevin; O’Byrne, Sheila M.; Jiang, Hongfeng; Clerkin, Kara; Benhammou, Jihane; Blaner, William S.; Beaven, Simon W.

2014-01-01

Liver X receptors (LXRs) are determinants of hepatic stellate cell (HSC) activation and liver fibrosis. Freshly isolated HSCs from Lxrαβ−/− mice have increased lipid droplet (LD) size but the functional consequences of this are unknown. Our aim was to determine whether LXRs link cholesterol to retinoid storage in HSCs and how this impacts activation. Primary HSCs from Lxrαβ−/− and wild-type (WT) mice were profiled by gene array during in vitro activation. Lipid content was quantified by HPLC and mass spectroscopy. Primary HSCs were treated with nuclear receptor ligands, transfected with siRNA and plasmid constructs, and analyzed by immunocytochemistry. Lxrαβ−/− HSCs have increased cholesterol and retinyl esters (CEs & REs). The retinoid increase drives intrinsic retinoic acid receptor (RAR) signaling and activation occurs more rapidly in Lxrαβ−/− HSCs. We identify Rab18 as a novel retinoic acid responsive, lipid droplet associated protein that helps mediate stellate cell activation. Rab18 mRNA, protein, and membrane insertion increase during activation. Both Rab18 GTPase activity and isoprenylation are required for stellate cell lipid droplet loss and induction of activation markers. These phenomena are accelerated in the Lxrαβ−/− HSCs, where there is greater retinoic acid flux. Conversely, Rab18 knockdown retards lipid droplet loss in culture and blocks activation, just like the functional mutants. Rab18 is also induced with acute liver injury in vivo. Conclusion Retinoid and cholesterol metabolism are linked in stellate cells by the LD associated protein, Rab18. Retinoid overload helps explain the pro-fibrotic phenotype of Lxrαβ−/− mice and we establish a pivotal role for Rab18 GTPase activity and membrane insertion in wild-type stellate cell activation. Interference with Rab18 may have significant therapeutic benefit in ameliorating liver fibrosis. PMID:25482505

Liver X receptors balance lipid stores in hepatic stellate cells through Rab18, a retinoid responsive lipid droplet protein.

PubMed

O'Mahony, Fiona; Wroblewski, Kevin; O'Byrne, Sheila M; Jiang, Hongfeng; Clerkin, Kara; Benhammou, Jihane; Blaner, William S; Beaven, Simon W

2015-08-01

Liver X receptors (LXRs) are determinants of hepatic stellate cell (HSC) activation and liver fibrosis. Freshly isolated HSCs from Lxrαβ(-/-) mice have increased lipid droplet (LD) size, but the functional consequences of this are unknown. Our aim was to determine whether LXRs link cholesterol to retinoid storage in HSCs and how this impacts activation. Primary HSCs from Lxrαβ(-/-) and wild-type mice were profiled by gene array during in vitro activation. Lipid content was quantified by high-performance liquid chromatography and mass spectroscopy. Primary HSCs were treated with nuclear receptor ligands, transfected with small interfering RNA and plasmid constructs, and analyzed by immunocytochemistry. Lxrαβ(-/-) HSCs have increased cholesterol and retinyl esters. The retinoid increase drives intrinsic retinoic acid receptor signaling, and activation occurs more rapidly in Lxrαβ(-/-) HSCs. We identify Rab18 as a novel retinoic acid-responsive, LD-associated protein that helps mediate stellate cell activation. Rab18 mRNA, protein, and membrane insertion increase during activation. Both Rab18 guanosine triphosphatase activity and isoprenylation are required for stellate cell LD loss and induction of activation markers. These phenomena are accelerated in Lxrαβ(-/-) HSCs, where there is greater retinoic acid flux. Conversely, Rab18 knockdown retards LD loss in culture and blocks activation, just like the functional mutants. Rab18 is also induced with acute liver injury in vivo. Retinoid and cholesterol metabolism are linked in stellate cells by the LD-associated protein Rab18. Retinoid overload helps explain the profibrotic phenotype of Lxrαβ(-/-) mice, and we establish a pivotal role for Rab18 GTPase activity and membrane insertion in wild-type stellate cell activation. Interference with Rab18 may have significant therapeutic benefit in ameliorating liver fibrosis. © 2015 by the American Association for the Study of Liver Diseases.

MicroRNA-212 activates hepatic stellate cells and promotes liver fibrosis via targeting SMAD7.

PubMed

Zhu, Jie; Zhang, Ziqiang; Zhang, Yitong; Li, Wenshuai; Zheng, Wanwei; Yu, Jianghong; Wang, Bangting; Chen, Lirong; Zhuo, Qin; Chen, Lin; Zhang, Jun; Liu, Jie

2018-01-29

There has been an increasing number of researches about microRNAs (miRNAs) in the progression of liver fibrosis from the point of their comprehensive functions in regulating the activation of hepatic stellate cells (HSCs). Among them, it has been reported that miR-212 is up-regulated in activated rat primary HSCs. However, its mechanism has not been determined yet. Here, we confirmed that the level of miR-212-3p was up-regulated in livers of carbon tetrachloride (CCl 4 )-treated mice compared with the normal control, which is a classical model of chronically damaged fibrotic liver. In vitro, we demonstrated that TGF-β, a master fibrogenic cytokine, could induce the level of miR-212. In turn, overexpression of miR-212 could induce the activation marker of HSC including α-smooth muscle actin (α-SMA) and collagens by activating TGF-β signaling pathway. Furthermore, SMAD7, a dominant suppressor of TGF-β pathway, was identified as a direct target of miR-212-3p. Our results indicate that miR-212-3p facilitates the activation of HSCs and TGF-β pathway by targeting SMAD7, highlighting that it can be served as a novel biomarker or therapeutic target for liver fibrosis. Copyright © 2018 Elsevier Inc. All rights reserved.

Immunodetection of hepatic stellate cells in dogs with visceral leishmaniasis.

PubMed

Marques, Natália Cassaro; Mo Reira, Pamela Rodrigues Reina; Bertolo, Paulo Henrique Leal; Gava, Fábio Nelson; Vasconcelos, Rosemeri de Oliveira

2018-06-01

Hepatic stellate cells (HSC), or Ito cells, store vitamin A when at rest but undergo phenotypic changes in situations of liver injury, which may induce fibrosis, and they may participate in the immune response in the liver. The objective of the present study was to investigate the role of HSC in the livers of dogs with visceral leishmaniasis (VL). Twenty-eight livers from dogs infected with VL that were living in an area endemic for the disease were evaluated, among which 13 were asymptomatic (A) and 15 were symptomatic (S). A control group (C) was formed by five dogs from an area that was not endemic for VL. These organs were subjected to histopathological analysis (Masson's trichrome for fibrosis) and immunohistochemical analysis (Leishmania, smooth-muscle α-actin and TGF-β). In the livers from the symptomatic dogs, a moderate to severe granulomatous inflammatory reaction was observed in the capsule and in the portal, centrilobular and intralobular regions. In the asymptomatic dogs, there was slight to moderate presence of granulomas, and these were even absent in some dogs. The intensity of hepatic fibrosis was predominantly low in the infected dogs (A and S), and fibrosis was absent in the control group. The immunomarking of HSC in the infected groups (A and S) differed significantly (P = 0.0153) from that of the control group. The symptomatic dogs presented the largest number of positive cells. This group also presented a larger number of parasitized macrophages, but did not differ statistically from the asymptomatic group (P > 0.05). The cytokine TGF-β was only detected at low levels, and only in the infected animals, but this did not differ from the control group. Immunomarking for HSC was observed mainly in the nuclei of cells present in the hepatic granulomas of symptomatic dogs and in the sinusoids of the asymptomatic dogs. It was concluded that in the livers of dogs with VL, the HSC are activated and participate in the hepatic response to the

Hepatic stellate cell-targeted imatinib nanomedicine versus conventional imatinib: A novel strategy with potent efficacy in experimental liver fibrosis.

PubMed

El-Mezayen, Nesrine S; El-Hadidy, Wessam F; El-Refaie, Wessam M; Shalaby, Th I; Khattab, Mahmoud M; El-Khatib, Aiman S

2017-11-28

Liver fibrosis is a global health problem without approved treatment. Imatinib inhibits two key profibrotic pathways; platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-β) and thus can be used to treat liver fibrosis. However, conventional imatinib therapy is hampered by low concentration at target tissue and increased toxicity to other tissues especially heart, lung and liver. Since hepatic stellate cells (HSCs) are the main contributors to liver fibrosis pathogenesis and sole hepatic vitamin A (V A ) storage cells, they can be actively targeted by coupling liposomes to V A . In this study, novel V A -coupled imatinib-loaded liposomes (ILC) were prepared and optimized regarding V A -coupling efficiency, imatinib entrapment efficiency, and particle size. Preferential accumulation of the selected formula in liver was proved by tracing intraperitoneally (i.p.)-injected V A -coupled liposomes loaded with Nile Red (LCNR) to rats with CCl 4 -induced liver fibrosis using live animal imaging. Co-localization of LCNR with immunofluorescently-labeled PDGFR-β in frozen liver tissue sections confirmed HSCs targeting. ILC bio-distribution, following single i.p. injection, revealed 13.5 folds higher hepatic accumulation than conventional imatinib in addition to limited bio-distribution to other organs including heart and lung reflecting diminished adverse effects. ILC therapy resulted in a potent inhibition of phosphorylated PDGFR-β expression when compared to conventional imatinib. Subsequently, there was a statistically significant improvement in liver function tests and reversal of hepatotoxicity along with liver fibrosis. Anti-fibrotic effect was evident from histopathologic Ishak score reduction as well as normalization of the level of profibrotic mediators (hydroxyproline, TGF-B and matrix metalloproteinase-2). Thus, HSC-targeted imatinib therapy shows outstanding anti-fibrotic effects with reduced cytotoxicity compared to conventional

Effect of chlorogenic acid on LPS-induced proinflammatory signaling in hepatic stellate cells.

PubMed

Shi, Haitao; Dong, Lei; Dang, Xiaoyan; Liu, Yaping; Jiang, Jiong; Wang, Yan; Lu, Xiaolan; Guo, Xiaoyan

2013-06-01

This study was aimed at investigating the effect of chlorogenic acid (CGA) on lipopolysaccharide (LPS)-induced proinflammatory signaling in hepatic stellate cells (HSCs). An immortalized rat HSC line was cultured in vitro and treated with LPS in the absence or presence of CGA. Reactive oxygen species (ROS) production in the HSCs was monitored by flow cytometer using DCFH-DA. The protein expression levels of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), nuclear factor-κB (NF-κB), and p-IκB-α were determined by Western blot. The mRNA expression levels of TLR4, MyD88, monocyte chemotactic protein 1(MCP-1), and interleukin 6 (IL-6) were detected by RT-PCR. The levels of MCP-1 and IL-6 in the culture supernatant of HSCs were measured by ELISA. CGA had no effect on expression of TLR4 and MyD88. However, the treatment of CGA can inhibit LPS-induced production of ROS in HSCs. Meanwhile, CGA can inhibit LPS-induced nuclear translocation of NF-κB and IκB-α phosphorylation in HSCs, as well as NAC (a ROS scavenger). The mRNA expression and the levels of MCP-1 and IL-6 in the culture supernatant of the HSCs in this study were elevated by LPS stimulation and inhibited by CGA treatment, as well as NAC and PDTC (a NF-κB inhibitor). Our results indicate that CGA can efficiently inhibit LPS-induced proinflammatory responses in HSCs and the anti-inflammatory effect may be due to the inhibition of LPS/ROS/NF-κB signaling pathway.

Aqueous Date Flesh or Pits Extract Attenuates Liver Fibrosis via Suppression of Hepatic Stellate Cell Activation and Reduction of Inflammatory Cytokines, Transforming Growth Factor-β1 and Angiogenic Markers in Carbon Tetrachloride-Intoxicated Rats

PubMed Central

Al-Rasheed, Nouf M.; Attia, Hala A.; Mohamad, Raeesa A.; Al-Rasheed, Nawal M.; Al-Amin, Maha A.; AL-Onazi, Asma

2015-01-01

Previous data indicated the protective effect of date fruit extract on oxidative damage in rat liver. However, the hepatoprotective effects via other mechanisms have not been investigated. This study was performed to evaluate the antifibrotic effect of date flesh extract (DFE) or date pits extract (DPE) via inactivation of hepatic stellate cells (HSCs), reducing the levels of inflammatory, fibrotic and angiogenic markers. Coffee was used as reference hepatoprotective agent. Liver fibrosis was induced by injection of CCl4 (0.4 mL/kg) three times weekly for 8 weeks. DFE, DPE (6 mL/kg), coffee (300 mg/kg), and combination of coffee + DFE and coffee + DPE were given to CCl4-intoxicated rats daily for 8 weeks. DFE, DPE, and their combination with coffee attenuated the elevated levels of inflammatory cytokines including tumor necrosis factor-α, interleukin-6, and interleukin-1β. The increased levels of transforming growth factor-β1 and collagen deposition in injured liver were alleviated by both extracts. CCl4-induced expression of α-smooth muscle actin was suppressed indicating HSCs inactivation. Increased angiogenesis was ameliorated as revealed by reduced levels and expression of vascular endothelial growth factor and CD31. We concluded that DFE or DPE could protect liver via different mechanisms. The combination of coffee with DFE or DPE may enhance its antifibrotic effects. PMID:25945106

A retinoic acid receptor β2 agonist reduces hepatic stellate cell activation in nonalcoholic fatty liver disease.

PubMed

Trasino, Steven E; Tang, Xiao-Han; Jessurun, Jose; Gudas, Lorraine J

2016-10-01

Hepatic stellate cells (HSCs) are an important cellular target for the development of novel pharmacological therapies to prevent and treat nonalcoholic fatty liver diseases (NAFLD). Using a high fat diet (HFD) model of NAFLD, we sought to determine if synthetic selective agonists for retinoic acid receptor β2 (RARβ2) and RARγ can mitigate HSC activation and HSC relevant signaling pathways during early stages of NAFLD, before the onset of liver injury. We demonstrate that the highly selective RARβ2 agonist, AC261066, can reduce the activation of HSCs, marked by decreased HSC expression of α-smooth muscle actin (α-SMA), in mice with HFD-induced NAFLD. Livers of HFD-fed mice treated with AC261066 exhibited reduced steatosis, oxidative stress, and expression of pro-inflammatory mediators, such as tumor necrosis factor-alpha (TNFα), interleukin 1β (IL-1β), and monocyte chemotactic protein-1 (MCP-1). Kupffer cell (macrophage) expression of transforming growth factor-β1 (TGF-β1), which plays a critical role in early HSC activation, was markedly reduced in AC261066-treated, HFD-fed mice. In contrast, HFD-fed mice treated with an RARγ agonist (CD1530) showed no decreases in steatosis, HSC activation, or Kupffer cell TGF-β1 levels. In conclusion, our data demonstrate that RARβ2 is an attractive target for development of NAFLD therapies. • Hepatic stellate cells (HSCs) are an important pharmacological target for the prevention of nonalcoholic fatty liver diseases (NAFLD). • Retinoids and retinoic acid receptors (RARs) possess favorable metabolic modulating properties. • We show that an agonist for retinoic acid receptor-β2 (RARβ2), but not RARγ, mitigates HSC activation and NAFLD.

Alteration of hepatic structure and oxidative stress induced by intravenous nanoceria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tseng, Michael T., E-mail: mttsen01@louisville.edu; Lu, Xiaoqin, E-mail: x0lu0003@louisville.edu; Duan, Xiaoxian, E-mail: x0duan02@louisville.edu

2012-04-15

Beyond the traditional use of ceria as an abrasive, the scope of nanoceria applications now extends into fuel cell manufacturing, diesel fuel additives, and for therapeutic intervention as a putative antioxidant. However, the biological effects of nanoceria exposure have yet to be fully defined, which gave us the impetus to examine its systemic biodistribution and biological responses. An extensively characterized nanoceria (5 nm) dispersion was vascularly infused into rats, which were terminated 1 h, 20 h or 30 days later. Light and electron microscopic tissue characterization was conducted and hepatic oxidative stress parameters determined. We observed acute ceria nanoparticle sequestrationmore » by Kupffer cells with subsequent bioretention in parenchymal cells as well. The internalized ceria nanoparticles appeared as spherical agglomerates of varying dimension without specific organelle penetration. In hepatocytes, the agglomerated nanoceria frequently localized to the plasma membrane facing bile canaliculi. Hepatic stellate cells also sequestered nanoceria. Within the sinusoids, sustained nanoceria bioretention was associated with granuloma formations comprised of Kupffer cells and intermingling CD3{sup +} T cells. A statistically significant elevation of serum aspartate aminotransferase (AST) level was seen at 1 and 20 h, but subsided by 30 days after ceria administration. Further, elevated apoptosis was observed on day 30. These findings, together with increased hepatic protein carbonyl levels on day 30, indicate ceria-induced hepatic injury and oxidative stress, respectively. Such observations suggest a single vascular infusion of nanoceria can lead to persistent hepatic retention of particles with possible implications for occupational and therapeutic exposures. -- Highlights: ► Time course study on nanoceria induced hepatic alterations in rats. ► Serum AST elevation indicated acute hepatotoxicity. ► Ceria is retained for up to 30 days in Kupffer

Endothelin and hepatic wound healing

PubMed Central

Khimji, Al-karim; Rockey, Don C.

2014-01-01

Liver wound healing is a coordinated response to injury caused by infections (hepatitis) or toxins (alcohol) or other processes where activation of hepatic stellate cells are a central component. During stellate cell activation, a major phenotypic transformation occurs which leads to increased production of increased extracellular matrix proteins and smooth muscle α-actin the results is organ dysfunction due to gross architectural disruption and impaired blood flow. Endothelin-1 (ET-1) is produced in increased amounts and the cellular source of ET-1 shifts from endothelial cells to stellate cells during liver injury thus setting a feedback loop which accentuates further activation, stellate cell proliferation, and production of extracellular matrix proteins. Therapy directed at intervening the ET-1 signaling pathway has significant therapeutic potential in patients with liver disease. PMID:21421048

Liver myofibroblasts of murine origins express mesothelin: Identification of novel rat mesothelin splice variants*

PubMed Central

G. Lavoie, Elise; Dranoff, Jonathan A.

2017-01-01

Liver myofibroblasts are specialized effector cells that drive hepatic fibrosis, a hallmark process of chronic liver diseases, leading to progressive scar formation and organ failure. Liver myofibroblasts are increasingly recognized as heterogeneous with regards to their origin, phenotype, and functions. For instance, liver myofibroblasts express cell markers that are universally represented such as, ItgαV and Pdgfrβ, or restricted to a given subpopulation such as, Lrat exclusively expressed in hepatic stellate cells, and Gpm6a in mesothelial cells. To study liver myofibroblasts in vitro, we have previously generated and characterized a SV40-immortalized polyclonal rat activated portal fibroblast cell line called RGF-N2 expressing multiple mesothelin mRNA transcripts. Mesothelin, a cell-surface molecule expressed in normal mesothelial cells and overexpressed in several cancers such as, mesothelioma and cholangiocarcinoma, was recently identified as a key regulator of portal myofibroblast proliferation, and fibrosis progression in the setting of chronic cholestatic liver disease. Here, we identify novel mesothelin splice variants expressed in rat activated portal fibroblasts. RGF-N2 portal fibroblast cDNA was used as template for insertion of hemagglutinin tag consensus sequence into the complete open reading frame of rat mesothelin variant coding sequences by extension PCR. Purified amplicons were subsequently cloned into an expression vector for in vitro translation and transfection in monkey COS7 fibroblasts, before characterization of fusion proteins by immunoblot and immunofluorescence. We show that rat activated portal fibroblasts, hepatic stellate cells, and cholangiocarcinoma cells express wild-type mesothelin and additional splice variants, while mouse activated hepatic stellate cells appear to only express wild-type mesothelin. Notably, rat mesothelin splice variants differ from the wild-type isoform by their protein properties and cellular distribution

Nicotine induces fibrogenic changes in human liver via nicotinic acetylcholine receptors expressed on hepatic stellate cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soeda, Junpei; Morgan, Maelle; McKee, Chad

Highlights: Black-Right-Pointing-Pointer Cigarette smoke may induce liver fibrosis via nicotine receptors. Black-Right-Pointing-Pointer Nicotine induces proliferation of hepatic stellate cells (HSCs). Black-Right-Pointing-Pointer Nicotine activates hepatic fibrogenic pathways. Black-Right-Pointing-Pointer Nicotine receptor antagonists attenuate HSC proliferation. Black-Right-Pointing-Pointer Nicotinic receptor antagonists may have utility as novel anti-fibrotic agents. -- Abstract: Background and aims: Cigarette smoke (CS) may cause liver fibrosis but possible involved mechanisms are unclear. Among the many chemicals in CS is nicotine - which affects cells through nicotinic acetylcholine receptors (nAChR). We studied the effects of nicotine, and involved pathways, on human primary hepatic stellate cells (hHSCs), the principal fibrogenic cells inmore » the liver. We then determined possible disease relevance by assaying nAChR in liver samples from human non-alcoholic steatohepatitis (NASH). Methods: hHSC were isolated from healthy human livers and nAChR expression analyzed - RT-PCR and Western blotting. Nicotine induction of hHSC proliferation, upregulation of collagen1-{alpha}2 and the pro-fibrogenic cytokine transforming growth factor beta 1 (TGF-{beta}1) was determined along with involved intracellular signaling pathways. nAChR mRNA expression was finally analyzed in whole liver biopsies obtained from patients diagnosed with non-alcoholic steatohepatitis (NASH). Results: hHSCs express muscle type ({alpha}1, {beta}1, delta and epsilon) and neuronal type ({alpha}3, {alpha}6, {alpha}7, {beta}2 and {beta}4) nAChR subunits at the mRNA level. Among these subunits, {alpha}3, {alpha}7, {beta}1 and {epsilon} were predominantly expressed as confirmed by Western blotting. Nicotine induced hHSC proliferation was attenuated by mecamylamine (p < 0.05). Additionally, collagen1-{alpha}2 and TGF-{beta}1 mRNA expression were significantly upregulated by nicotine and inhibited by

Hepatic Stellate Cells Alter Liver Immune Environment to Promote Cancer | Center for Cancer Research

Cancer.gov

Hepatocellular carcinoma (HCC) is the most common form of liver cancer, accounting for up to 90 percent of cases, and is the second most common cause of cancer-related deaths worldwide according to the World Health Organization’s 2014 World Cancer Report. Even when caught early, HCC often recurs, either from intra-liver metastases or new primary tumors, and recurrence is the leading cause of death for patients with HCC. The liver microenvironment is an important contributor to HCC initiation and progression and also likely plays a role in tumor recurrence. Xin Wei Wang, Ph.D., of CCR’s Laboratory of Human Carcinogenesis, and his colleagues wondered whether activated hepatic stellate cells (A-HSCs), stromal cells in the liver known to participate in repair following injury and in the development of fibrosis, contribute directly to HCC recurrence.

RNA Sequencing and Bioinformatics Analysis Implicate the Regulatory Role of a Long Noncoding RNA-mRNA Network in Hepatic Stellate Cell Activation.

PubMed

Guo, Can-Jie; Xiao, Xiao; Sheng, Li; Chen, Lili; Zhong, Wei; Li, Hai; Hua, Jing; Ma, Xiong

2017-01-01

To analyze the long noncoding (lncRNA)-mRNA expression network and potential roles in rat hepatic stellate cells (HSCs) during activation. LncRNA expression was analyzed in quiescent and culture-activated HSCs by RNA sequencing, and differentially expressed lncRNAs verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR) were subjected to bioinformatics analysis. In vivo analyses of differential lncRNA-mRNA expression were performed on a rat model of liver fibrosis. We identified upregulation of 12 lncRNAs and 155 mRNAs and downregulation of 12 lncRNAs and 374 mRNAs in activated HSCs. Additionally, we identified the differential expression of upregulated lncRNAs (NONRATT012636.2, NONRATT016788.2, and NONRATT021402.2) and downregulated lncRNAs (NONRATT007863.2, NONRATT019720.2, and NONRATT024061.2) in activated HSCs relative to levels observed in quiescent HSCs, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed that changes in lncRNAs associated with HSC activation revealed 11 significantly enriched pathways according to their predicted targets. Moreover, based on the predicted co-expression network, the relative dynamic levels of NONRATT013819.2 and lysyl oxidase (Lox) were compared during HSC activation both in vitro and in vivo. Our results confirmed the upregulation of lncRNA NONRATT013819.2 and Lox mRNA associated with the extracellular matrix (ECM)-related signaling pathway in HSCs and fibrotic livers. Our results detailing a dysregulated lncRNA-mRNA network might provide new treatment strategies for hepatic fibrosis based on findings indicating potentially critical roles for NONRATT013819.2 and Lox in ECM remodeling during HSC activation. © 2017 The Author(s). Published by S. Karger AG, Basel.

Oxidative stress and hepatic stellate cell activation are key events in arsenic induced liver fibrosis in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghatak, Subhadip; Biswas, Ayan; Dhali, Gopal Krishna

2011-02-15

Arsenic is an environmental toxicant and carcinogen. Exposure to arsenic is associated with development of liver fibrosis and portal hypertension through ill defined mechanisms. We evaluated hepatic fibrogenesis after long term arsenic exposure in a murine model. BALB/c mice were exposed to arsenic by daily gavages of 6 {mu}g/gm body weight for 1 year and were evaluated for markers of hepatic oxidative stress and fibrosis, as well as pro-inflammatory, pro-apoptotic and pro-fibrogenic factors at 9 and 12 months. Hepatic NADPH oxidase activity progressively increased in arsenic exposure with concomitant development of hepatic oxidative stress. Hepatic steatosis with occasional collection ofmore » mononuclear inflammatory cells and mild portal fibrosis were the predominant liver lesion observed after 9 months of arsenic exposure, while at 12 months, the changes included mild hepatic steatosis, inflammation, necrosis and significant fibrosis in periportal areas. The pathologic changes in the liver were associated with markers of hepatic stellate cells (HSCs) activation, matrix reorganization and fibrosis including {alpha}-smooth muscle actin, transforming growth factor-{beta}1, PDGF-R{beta}, pro-inflammatory cytokines and enhanced expression of tissue inhibitor of metalloproteinase-1 and pro({alpha}) collagen type I. Moreover, pro-apoptotic protein Bax was dominantly expressed and Bcl-2 was down-regulated along with increased number of TUNEL positive hepatocytes in liver of arsenic exposed mice. Furthermore, HSCs activation due to increased hepatic oxidative stress observed after in vivo arsenic exposure was recapitulated in co-culture model of isolated HSCs and hepatocytes exposed to arsenic. These findings have implications not only for the understanding of the pathology of arsenic related liver fibrosis but also for the design of preventive strategies in chronic arsenicosis.« less

TGF-β1-elevated TRPM7 channel regulates collagen expression in hepatic stellate cells via TGF-β1/Smad pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang, Ling, E-mail: fangling_1984@126.com; Institute for Liver Diseases of Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032; Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Mei Shan Road, Hefei, Anhui Province 230032

Transdifferentiation of hepatic stellate cells (HSCs) into myofibroblasts plays a critical role in the development of liver fibrosis, since myofibroblasts are the key cells responsible for excessive deposition of ECM proteins. Transient receptor potential melastatin 7 (TRPM7), a non-selective cation channel with protein serine/threonine kinase activity, has been demonstrated to function in the proliferation of activated HSCs. Here, we investigated the functional role of TRPM7 in collagen deposition in activated HSC-T6 cells (a rat hepatic stellate cell line). TRPM7 mRNA and protein were measured by Real-time PCR and Western blot in TGF-β1-activated HSC-T6 cells in vitro. Results demonstrated that TRPM7more » protein was dramatically increased in fibrotic human livers. Stimulation of HSC-T6 cells with TGF-β1 increased TRPM7 mRNA and protein level in a time-dependent manner. Nevertheless, TGF-β1-elicited upregulation of TRPM7 in HSC-T6 cells was abrogated by SB431542 (TGF-β1 receptor blocker) or SIS3 (inhibitor of Smad3 phosphorylation). Additionally, blockade of TRPM7 channels with non-specific TRPM7 blocker 2-APB or synthetic siRNA targeting TRPM7 attenuated TGF-β1-induced expression of myofibroblast markers, as measured by the induction of α-SMA and Col1α1. Silencing TRPM7 also increased the ratio of MMPs/TIMPs by increasing MMP-13 expression and decreasing TIMP-1 and TIMP-2 levels. Strikingly, phosphorylation of p-Smad2 and p-Smad3, associated with collagen production, was decreased in TRPM7 deficient HSC-T6 cells. These observations suggested that TGF-β1 elevates TRPM7 expression in HSCs via Smad3-dependant mechanisms, which in turn contributes Smad protein phosphorylation, and subsequently increases fibrous collagen expression. Therefore, TRPM7 may constitute a useful target for the treatment of liver fibrosis. - Highlights: • Upregulation of TRPM7 protein in human fibrotic livers • Upregulation of TRPM7 by TGF-β1 elicited Smad signaling in HSC

Silibinin induces hepatic stellate cell cycle arrest via enhancing p53/p27 and inhibiting Akt downstream signaling protein expression.

PubMed

Ezhilarasan, Devaraj; Evraerts, Jonathan; Sid, Brice; Calderon, Pedro Buc; Karthikeyan, Sivanesan; Sokal, Etienne; Najimi, Mustapha

2017-02-01

Proliferation of hepatic stellate cells (HSCs) plays a pivotal role in the progression of liver fibrosis consequent to chronic liver injury. Silibinin, a flavonoid compound, has been shown to possess anti-fibrogenic effects in animal models of liver fibrosis. This was attributed to an inhibition of cell proliferation of activated HSCs. The present study was to gain insight into the molecular pathways involved in silibinin anti-fibrogenic effect. The study was conducted on LX-2 human stellate cells treated with three concentrations of silibinin (10, 50 and 100 μmol/L) for 24 and 96 hours. At the end of the treatment cell viability and proliferation were evaluated. Protein expression of p27, p21, p53, Akt and phosphorylated-Akt was evaluated by Western blotting analysis and Ki-67 protein expression was by immunocytochemistry. Sirtuin activity was evaluated by chemiluminescence based assay. Silibinin inhibits LX-2 cell proliferation in dose- and time-dependent manner; we showed that silibinin upregulated the protein expressions of p27 and p53. Such regulation was correlated to an inhibition of both downstream Akt and phosphorylated-Akt protein signaling and Ki-67 protein expression. Sirtuin activity also was correlated to silibinin-inhibited proliferation of LX-2 cells. The anti-proliferative effect of silibinin on LX-2 human stellate cells is via the inhibition of the expressions of various cell cycle targets including p27, Akt and sirtuin signaling.

ALLYLISOPROPYLACETAMIDE INDUCES RAT HEPATIC ORNITHINE DECARBOXYLASE

EPA Science Inventory

In rat liver, allylisopropylacetamide (AIA) treatment strongly induced (25-fold) the activity of rat hepatic ornithine decarboxylase (ODC). y either the oral or the subcutaneous routes, AIA produced a long-lasting induction (30 to 4O hours) of hepatic ODC activity. hree analogs o...

Hop bitter acids exhibit anti-fibrogenic effects on hepatic stellate cells in vitro.

PubMed

Saugspier, Michael; Dorn, Christoph; Thasler, Wolfgang E; Gehrig, Manfred; Heilmann, Jörg; Hellerbrand, Claus

2012-04-01

Female inflorescences of the hop plant Humulus lupulus L. contain a variety of secondary metabolites with bitter acids (BA) as quantitatively dominating secondary metabolites. The use of hops in beer brewing has a long history due to the antibacterial effects of the BA and their typical bitter taste. Furthermore, hop cones are used in traditional medicine and for pharmaceutical purposes. Recent studies indicate that BA may affect activity of the transcription factor NFκB. NFκB plays a key role in the activation process of hepatic stellate cells (HSC), which is the key event of hepatic fibrosis. The aim of this study was to investigate the effect of BA on HSC (activation) and their potential to inhibit molecular processes involved in the pathogenesis of hepatic fibrosis. HSC were isolated from murine and human liver tissue and incubated with a characterized fraction of bitter acids purified from a CO(2) hop extract. At a concentration of 25μg/ml BA started to induce LDH leakage. Already at lower concentrations BA lead to a dose dependent inhibition of HSC proliferation and inhibited IκB-α-phosphorylation, nuclear p65 translocation and binding activity in a dose dependent way (up to 10μg/ml). Accordingly, the same BA-doses inhibited the expression of pro-inflammatory and NFκB regulated genes as MCP-1 and RANTES, but did not affect expression of genes not related to NFκB signaling. In addition to the effect on activated HSC, BA inhibited the in vitro activation process of freshly isolated HSC as evidenced by delayed expression of collagen I and α-SMA mRNA and protein. Together, these findings indicate that BA inhibit NFκB activation, and herewith the activation and development of profibrogenic phenotype of HSC. Thus, bitter acids appear as potential functional nutrients for the prevention or treatment hepatic fibrosis in chronic liver disease. Copyright © 2011 Elsevier Inc. All rights reserved.

Nonselective inhibition of prostaglandin-endoperoxide synthase by naproxen ameliorates hepatic injury in animals with acute or chronic liver injury

PubMed Central

Bahde, Ralf; Kapoor, Sorabh; Gupta, Sanjeev

2014-01-01

The rising prevalence of hepatic injury due to toxins, metabolites, viruses, etc., necessitates development of further mechanisms for protecting the liver and for treating acute or chronic liver diseases. To examine whether inhibition of inflammation directed by cyclo-oxygenase pathways, we performed animal studies with naproxen, which inhibits prostaglandin-endoperoxide synthases 1 and 2 and is in extensive clinical use. We administered carbon tetrachloride to induce acute liver injury and ligated the common bile duct to induce chronic liver injury in adult rats. These experimental manipulations produced abnormalities in liver tests, tissue necrosis, compensatory hepatocyte or biliary proliferation, and onset of fibrosis, particularly after bile duct ligation. After carbon tetrachloride-induced acute injury, naproxen decreased liver test abnormalities, tissue necrosis and compensatory hepatocellular proliferation. After bile duct ligation-induced chronic injury, naproxen decreased liver test abnormalities, tissue injury and compensatory biliary hyperplasia. Moreover, after bile duct ligation, naproxen-treated rats showed more periductular oval liver cells, which have been classified as hepatic progenitor cells. In naproxen-treated rats, we found greater expression in hepatic stellate cells and mononuclear cells of cytoprotective factors, such as vascular endothelial growth factor. The ability of naproxen to induce expression of vascular endothelial growth factor was verified in cell culture studies with CFSC-8B clone of rat hepatic stellate cells. Whereas assays for carbon tetrachloride toxicity using cultured primary hepatocytes established that naproxen was not directly cytoprotective, we found conditioned medium containing vascular endothelial growth factor from naproxen-treated CFSC-8B cells protected hepatocytes from carbon tetrachloride toxicity. Therefore, naproxen was capable of ameliorating toxic liver injury, which involved naproxen-induced release of

Ultrastructural Characteristics of Rat Hepatic Oval Cells and Their Intercellular Contacts in the Model of Biliary Fibrosis: New Insights into Experimental Liver Fibrogenesis

PubMed Central

Lebensztejn, Dariusz Marek; Daniluk, Urszula; Sobaniec, Piotr; Sendrowski, Krzysztof; Daniluk, Jaroslaw; Debek, Wojciech

2017-01-01

Purpose Recently, it has been emphasized that hepatic progenitor/oval cells (HPCs) are significantly involved in liver fibrogenesis. We evaluated the multipotential population of HPCs by transmission electron microscope (TEM), including relations with adherent hepatic nonparenchymal cells (NPCs) in rats with biliary fibrosis induced by bile duct ligation (BDL). Methods The study used 6-week-old Wistar Crl: WI(Han) rats after BDL for 1, 6, and 8 weeks. Results Current ultrastructural analysis showed considerable proliferation of HPCs in experimental intensive biliary fibrosis. HPCs formed proliferating bile ductules and were scattered in periportal connective tissue. We distinguished 4 main types of HPCs: 0, I, II (bile duct-like cells; most common), and III (hepatocyte-like cells). We observed, very seldom presented in literature, cellular interactions between HPCs and adjacent NPCs, especially commonly found transitional hepatic stellate cells (T-HSCs) and Kupffer cells/macrophages. We showed the phenomenon of penetration of the basement membrane of proliferating bile ductules by cytoplasmic processes sent by T-HSCs and the formation of direct cell-cell contact with ductular epithelial cells related to HPCs. Conclusions HPC proliferation induced by BDL evidently promotes portal fibrogenesis. Better understanding of the complex cellular interactions between HPCs and adjacent NPCs, especially T-HSCs, may help develop antifibrotic therapies in the future. PMID:28769978

Melatonin suppresses activation of hepatic stellate cells through RORα-mediated inhibition of 5-lipoxygenase.

PubMed

Shajari, Shiva; Laliena, Almudena; Heegsma, Janette; Tuñón, María Jesús; Moshage, Han; Faber, Klaas Nico

2015-10-01

Liver fibrosis is scar tissue resulting from an uncontrolled wound-healing process in response to chronic liver injury. Liver damage generates an inflammatory reaction that activates hepatic stellate cells (HSC) that transdifferentiate from quiescent cells that control retinol metabolism to proliferative and migratory myofibroblasts that produce excessive amounts of extracellular matrix proteins, in particular collagen 1a1 (COL1A1). Although liver fibrosis is reversible, no effective drug therapy is available to prevent or reverse HSC activation. Melatonin has potent hepatoprotective properties in a variety of acute and chronic liver injury models and suppresses liver fibrosis. However, it remains unclear whether melatonin acts indirectly or directly on HSC to prevent liver fibrosis. Here, we studied the effect of melatonin on culture-activated rat HSC. Melatonin dose-dependently suppressed the expression of HSC activation markers Col1a1 and alpha-smooth muscle actin (αSMA, Acta2), as well as HSC proliferation and loss of lipid droplets. The nuclear melatonin sensor retinoic acid receptor-related orphan receptor-alpha (RORα/Nr1f1) was expressed in quiescent and activated HSC, while the membranous melatonin receptors (Mtrn1a and Mtrn1b) were not. The synthetic RORα agonist SR1078 more potently suppressed Col1a1 and αSma expression, HSC proliferation, and lipid droplet loss, while the RORα antagonist SR1001 blocked the antifibrotic features of melatonin. Melatonin and SR1078 inhibited the expression of Alox5, encoding 5-lipoxygenase (5-LO). The pharmacological 5-LO inhibitor AA861 reduced Acta2 and Col1a1 expression in activated HSC. We conclude that melatonin directly suppresses HSC activation via RORα-mediated inhibition of Alox5 expression, which provides novel drug targets to treat liver fibrosis. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Suppression of hedgehog signaling regulates hepatic stellate cell activation and collagen secretion.

PubMed

Li, Tao; Leng, Xi-Sheng; Zhu, Ji-Ye; Wang, Gang

2015-01-01

Hepatic stellate cells (HSCs) play an important role in liver fibrosis. This study investigates the expression of hedgehog in HSC and the role of hedgehog signaling on activation and collagen secretion of HSC. Liver ex vivo perfusion with collagenase IV and density gradient centrifugation were used to isolate HSC. Expression of hedgehog signaling components Ihh, Smo, Ptc, Gli2 and Gli3 in HSC were detected by RT-PCR. Hedgehog siRNA vectors targeting Ihh, Smo and Gli2 were constructed and transfected into HSC respectively. Suppression of hedgehog signaling were detected by SYBR Green fluorescence quantitative RT-PCR. Effects of hedgehog signaling inhibition on HSC activation and collagen I secretion were analyzed. Hedgehog signaling components Ihh, Smo, Ptc, Gli2 and Gli3 were expressed in HSC. siRNA vectors targeting Ihh, Smo and Gli2 were successfully constructed and decreased target gene expression. Suppression of hedgehog signaling significantly decreased the expression of α-SMA in HSC (P<0.01). Collagen type I secretion of HSC were also significantly decreased (P<0.01). In summary, HSC activation and collagen secretion can be regulated by hedgehog signaling. Hedgehog may play a role in the pathogenesis of liver fibrosis.

[Stimulation of human hepatic stellate cells by cytochrome P4502E1-mediated oxidative stress].

PubMed

Li, Jing; Liu, Tian-hui; You, Hong; Xu, You-qing; Wang, Chen

2010-08-01

To explore the stimulation of human hepatic stellate cells by Cytochrome P4502E1-mediated oxidative stress. HepG2-line was transfected with human CYP2E1 plasmid (HepG2/CYP2E1) and empty plasmid (HepG2/PCI) respectively. The CYP2E1 expression was evaluated with RT-PCR and Western blot. MDA was measured in culture medium of HepG2 cell lines. LX2 was co-incubated with HepG2/CYP2E1, HepG2/PCI and HepG2 respectively. The level of hydroxyproline in culture medium was examined in 48 hours and the cells were lysated and total RNA and protein were extracted. COL-1 and MMP2 mRNA levels were detected by RT-PCR and analyzed semi-quantitatively. PICP proteins were measured by ELISA. Zymography was performed to investigate MMP2 enzymatic activities. (1) MDA from the HepG2 which (HepG2/CYP2E1)express human CYP2E1 (6.51+/-0.25) was significantly higher than that from the HepG2 which do not (HepG2/PCI) express human CYP2E1 (3.07+/-0.29) and HepG2 alone (2.57+/-0.29). (F=22.66, all P<0.01). (2) After co-incubated for 48 hours,the level of hydroxyproline in culture medium (35.24+/-3.52) excreted from CYP2E1/LX2 could significantly increase (F=58.89, P is less than 0.01). PICP protein (540.01+/-11.38) excreted from CYP2E1/LX2 was significantly increased (F=124.97, P<0.01). Zymography showed MMP2 gene expression and enzymatic activities of MMP2 had no difference among the groups (F=0.29, P>0.05) (F=0.33, P>0.05). CYP2E1 derived oxidative stress mediated stimulation of collagen I synthesis by hepatic stellate cells. Hydroxyproline excreted by LX2 was increased by CYP2E1. COL-1mRNA had no difference among the groups (F=0.73, P>0.05).

Competitive inhibition of leptin signaling results in amelioration of liver fibrosis through modulation of stellate cell function.

PubMed

Elinav, Eran; Ali, Mohammad; Bruck, Rafi; Brazowski, Eli; Phillips, Adam; Shapira, Yami; Katz, Meirav; Solomon, Gila; Halpern, Zamir; Gertler, Arieh

2009-01-01

Leptin signaling is involved in T-cell polarization and is required for profibrotic function of hepatic stellate cells (HSCs). Leptin-deficient ob/ob mice do not develop liver fibrosis despite the presence of severe long-standing steatohepatitis. Here, we blocked leptin signaling with our recently generated mouse leptin antagonist (MLA), and examined the effects on chronic liver fibrosis in vivo using the chronic thioacetamide (TAA) fibrosis model, and in vitro using freshly-isolated primary HSCs. In the chronic TAA fibrosis model, leptin administration was associated with significantly enhanced liver disease and a 100% 5-week to 8-week mortality rate, while administration or coadministration of MLA markedly improved survival, attenuated liver fibrosis, and reduced interferon gamma (IFN-gamma) levels. No significant changes in weight, serum cholesterol, or triglycerides were noted. In vitro administration of rat leptin antagonist (RLA), either alone or with leptin, to rat primary HSCs reduced leptin-stimulated effects such as increased expression of alpha-smooth muscle actin (alpha-SMA), and activation of alpha1 procollagen promoter. Inhibition of leptin-enhanced hepatic fibrosis may hold promise as a future antifibrotic therapeutic modality.

Pancreatic stellate cells are activated by proinflammatory cytokines: implications for pancreatic fibrogenesis.

PubMed

Apte, M V; Haber, P S; Darby, S J; Rodgers, S C; McCaughan, G W; Korsten, M A; Pirola, R C; Wilson, J S

1999-04-01

The pathogenesis of pancreatic fibrosis is unknown. In the liver, stellate cells play a major role in fibrogenesis by synthesising increased amounts of collagen and other extracellular matrix (ECM) proteins when activated by profibrogenic mediators such as cytokines and oxidant stress. To determine whether cultured rat pancreatic stellate cells produce collagen and other ECM proteins, and exhibit signs of activation when exposed to the cytokines platelet derived growth factor (PDGF) or transforming growth factor beta (TGF-beta). Cultured pancreatic stellate cells were immunostained for the ECM proteins procollagen III, collagen I, laminin, and fibronectin using specific polyclonal antibodies. For cytokine studies, triplicate wells of cells were incubated with increasing concentrations of PDGF or TGF-beta. Cultured pancreatic stellate cells stained strongly positive for all ECM proteins tested. Incubation of cells with 1, 5, and 10 ng/ml PDGF led to a significant dose related increase in cell counts as well as in the incorporation of 3H-thymidine into DNA. Stellate cells exposed to 0.25, 0.5, and 1 ng/ml TGF-beta showed a dose dependent increase in alpha smooth muscle actin expression and increased collagen synthesis. In addition, TGF-beta increased the expression of PDGF receptors on stellate cells. Pancreatic stellate cells produce collagen and other extracellular matrix proteins, and respond to the cytokines PDGF and TGF-beta by increased proliferation and increased collagen synthesis. These results suggest an important role for stellate cells in pancreatic fibrogenesis.

Telmisartan prevents hepatic fibrosis and enzyme-altered lesions in liver cirrhosis rat induced by a choline-deficient L-amino acid-defined diet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin Haiyan; Department of Gastroenterology and Hepatology, Yanbian University Hospital, Yanji, Jilin; Yamamoto, Naoki

2007-12-28

Rennin-angiotensin system is involved in liver fibrogenesis through activating hepatic stellate cells (HSCs). Telmisartan (Tel) is an angiotensin II type 1 receptor antagonist, could function as a selective peroxisome proliferator-activated receptor {gamma} activator. Here we studied the effect of Tel on liver fibrosis, pre-neoplastic lesions in vivo and primary HSCs in vitro. In vivo study, we used the choline-deficient L-amino acid-defined (CDAA)-diet induced rat NASH model. The rats were fed the CDAA diet for 8 weeks to induce liver fibrosis and pre-neoplastic lesions, and then co-administrated with Tel for another 10 weeks. Tel prevented liver fibrogenesis and pre-neoplastic lesions bymore » down-regulating TGF{beta}1 and TIMP-1, 2 and increasing MMP-13 expression. Tel inhibited HSCs activation and proliferation. These results suggested that Tel could be a promising drug for NASH related liver fibrosis.« less

Telmisartan prevents hepatic fibrosis and enzyme-altered lesions in liver cirrhosis rat induced by a choline-deficient L-amino acid-defined diet.

PubMed

Jin, Haiyan; Yamamoto, Naoki; Uchida, Koichi; Terai, Shuji; Sakaida, Isao

2007-12-28

Rennin-angiotensin system is involved in liver fibrogenesis through activating hepatic stellate cells (HSCs). Telmisartan (Tel) is an angiotensin II type 1 receptor antagonist, could function as a selective peroxisome proliferator-activated receptor gamma activator. Here we studied the effect of Tel on liver fibrosis, pre-neoplastic lesions in vivo and primary HSCs in vitro. In vivo study, we used the choline-deficient L-amino acid-defined (CDAA)-diet induced rat NASH model. The rats were fed the CDAA diet for 8 weeks to induce liver fibrosis and pre-neoplastic lesions, and then co-administrated with Tel for another 10 weeks. Tel prevented liver fibrogenesis and pre-neoplastic lesions by down-regulating TGFbeta1 and TIMP-1, 2 and increasing MMP-13 expression. Tel inhibited HSCs activation and proliferation. These results suggested that Tel could be a promising drug for NASH related liver fibrosis.

Effect of shear stress on the migration of hepatic stellate cells.

PubMed

Sera, Toshihiro; Sumii, Tateki; Fujita, Ryosuke; Kudo, Susumu

2018-01-01

When the liver is damaged, hepatic stellate cells (HSCs) can change into an activated, highly migratory state. The migration of HSCs may be affected by shear stress due not only to sinusoidal flow but also by the flow in the space of Disse because this space is filled with blood plasma. In this study, we evaluated the effects of shear stress on HSC migration in a scratch-wound assay with a parallel flow chamber. At regions upstream of the wound area, the migration was inhibited by 0.6 Pa and promoted by 2.0 Pa shear stress, compared to the static condition. The platelet-derived growth factor (PDGF)-BB receptor, PDGFR-β, was expressed in all conditions and the differences were not significant. PDGF increased HSC migration, except at 0.6 Pa shear stress, which was still inhibited. These results indicate that another molecular factor, such as PDGFR-α, may act to inhibit the migration under low shear stress. At regions downstream of the wound area, the migration was smaller under shear stress than under the static condition, although the expression of PDGFR-β was significantly higher. In particular, the migration direction was opposite to the wound area under high shear stress; therefore, migration might be influenced by the intercellular environment. Our results indicate that HSC migration was influenced by shear stress intensity and the intercellular environment.

The interplay between hepatic stellate cells and hepatocytes in an in vitro model of NASH.

PubMed

Barbero-Becerra, Varenka J; Giraudi, Pablo J; Chávez-Tapia, Norberto C; Uribe, Misael; Tiribelli, Claudio; Rosso, Natalia

2015-10-01

A complex interplay exists between hepatocytes and hepatic stellate cells (HSC) in hepatic fibrogenesis. The activation of HSCs after liver injury leads to production of extracellular matrix (ECM). Co-culture models could be useful to mimic the liver microenvironment. This study evaluates the effect of free fatty acids (FFA) on HSC cells and the interplay with hepatocytes via both soluble-mediator and cell-cell contact. The human hepatocyte cell line (HuH7) and HSC cells (LX2) were exposed to FFA for 24 h in 3 different experimental set-ups: (A) monoculture of HSC; (B) Transwell® system (effect of soluble mediators); and (C) Simultaneous Co-Culture (SCC) (cell-to-cell connections). Intracellular FFA accumulation was assessed qualitatively (microscopy) and quantitatively (flow cytometry); the activation of HSC (alpha smooth muscle actin, α-SMA) expression of ECM components were quantified by RT-PCR. FFA exposure induces intracellular fat accumulation in all the experimental set-up but the expression of α-SMA was significantly increased only in SCC. On the contrary, the expression of ECM was substantially decreased in the transwell® system. The HSC activation is independent of FFA accumulation but requires cell-to-cell interaction with hepatocyte. On the contrary, the gene regulation of ECM components seems to occur through paracrine mediators. Copyright © 2015 Elsevier Ltd. All rights reserved.

Epigenetic Repression of Matrix Metalloproteinases in Myofibroblastic Hepatic Stellate Cells through Histone Deacetylases 4

PubMed Central

Qin, Lan; Han, Yuan-Ping

2010-01-01

Matrix metalloproteinases (MMPs), which are highly expressed in acute injury, are progressively repressed or silenced in fibrotic liver, favoring extracellular matrix accumulation, while the underlying mechanism is largely unknown. Similarly, normal/quiescent hepatic stellate cells (HSCs) express high levels of MMPs in response to injury signals, such as interleukin-1. After transdifferentiation, the myofibroblastic HSCs are incapable of expressing many MMPs; however, the major signaling pathways required for MMP expression are intact, indicating that repression is at the level of the chromatin. Indeed, both the MMP9 and MMP13 genes are inaccessible to transcription factors and RNA polymerase II, in association with impaired histone acetylation in their promoters. In accordance with impaired histone acetylation at the cellular level, histone deacetylase-4 is accumulated during HSC transdifferentiation. Furthermore, ectopic expression of histone deacetylase-4 in quiescent HSCs results in repression of MMP promoter activities as well as endogenous MMP9 protein expression. Thus, our findings suggest that a histone deacetylase-4-dependent mechanism underlies the epigenetic silencing of MMP genes during tissue fibrogenesis. PMID:20847282

Fate tracing reveals hepatic stellate cells as dominant contributors to liver fibrosis independent of its aetiology

NASA Astrophysics Data System (ADS)

Mederacke, Ingmar; Hsu, Christine C.; Troeger, Juliane S.; Huebener, Peter; Mu, Xueru; Dapito, Dianne H.; Pradere, Jean-Philippe; Schwabe, Robert F.

2013-11-01

Although organ fibrosis causes significant morbidity and mortality in chronic diseases, the lack of detailed knowledge about specific cellular contributors mediating fibrogenesis hampers the design of effective antifibrotic therapies. Different cellular sources, including tissue-resident and bone marrow-derived fibroblasts, pericytes and epithelial cells, have been suggested to give rise to myofibroblasts, but their relative contributions remain controversial, with profound differences between organs and different diseases. Here we employ a novel Cre-transgenic mouse that marks 99% of hepatic stellate cells (HSCs), a liver-specific pericyte population, to demonstrate that HSCs give rise to 82-96% of myofibroblasts in models of toxic, cholestatic and fatty liver disease. Moreover, we exclude that HSCs function as facultative epithelial progenitor cells in the injured liver. On the basis these findings, HSCs should be considered the primary cellular target for antifibrotic therapies across all types of liver disease.

Ferulic acid suppresses activation of hepatic stellate cells through ERK1/2 and Smad signaling pathways in vitro.

PubMed

Xu, Tianjiao; Pan, Zhi; Dong, Miaoxian; Yu, Chunlei; Niu, Yingcai

2015-01-01

Hepatic stellate cells (HSCs) are the primary source of matrix components in hepatic fibrosis. Ferulic acid (FA) has antifibrotic potential in renal and cardiac disease. However, whether FA comprises inhibitive effects of HSCs activation remains to be clarified. This study aims at evaluating the hypothesis that FA inhibits extracellular matrix (ECM)-related gene expression by the interruption of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) or/and Smad signaling pathways in HSC-T6. Our results indicated that FA significantly inhibited both viability and activation of HSC-T6 cells in vitro. In addition, we demonstrated, for the first time, that FA dramatically inhibited the expression of α1(I) collagen (Col-I) and fibronectin at levels of transcription and translation. Moreover, FA treatment inhibited Smad transcriptional activity, as evaluated by transient transfection with a plasmid construction containing SMAD response element and the luciferase reporter gene. Furthermore, FA inhibition of HSCs activation involved in both focal adhesion kinase (FAK)-dependent ERK1/2 and Smad signaling pathways with independent manner. Blocking transforming growth factor-β by a neutralizing antibody caused a marked reduction in both ERK1/2 and Smad signaling. These results support FA as an effective therapeutic agent for the prevention and treatment of hepatic fibrosis. Copyright © 2014 Elsevier Inc. All rights reserved.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) increases necroinflammation and hepatic stellate cell activation but does not exacerbate experimental liver fibrosis in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamb, Cheri L.; Cholico, Giovan N.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a persistent environmental contaminant and high-affinity ligand for the aryl hydrocarbon receptor (AhR). Increasing evidence indicates that AhR signaling contributes to wound healing, which involves the coordinated deposition and remodeling of the extracellular matrix. In the liver, wound healing is attributed to the activation of hepatic stellate cells (HSCs), which mediate fibrogenesis through the production of soluble mediators and collagen type I. We recently reported that TCDD treatment increases the activation of human HSCs in vitro. The goal of this study was to determine how TCDD impacts HSC activation in vivo using a mouse model of experimentalmore » liver fibrosis. To elicit fibrosis, C57BL6/male mice were treated twice weekly for 8 weeks with 0.5 ml/kg carbon tetrachloride (CCl{sub 4}). TCDD (20 μg/kg) or peanut oil (vehicle) was administered once a week during the last 2 weeks. Results indicate that TCDD increased liver-body-weight ratios, serum alanine aminotransferase activity, and hepatic necroinflammation in CCl{sub 4}-treated mice. Likewise, TCDD treatment increased mRNA expression of HSC activation and fibrogenesis genes, namely α-smooth muscle actin, desmin, delta-like homolog-1, TGF-β1, and collagen type I. However, TCDD treatment did not exacerbate fibrosis, nor did it increase the collagen content of the liver. Instead, TCDD increased hepatic collagenase activity and increased expression of matrix metalloproteinase (MMP)-13 and the matrix regulatory proteins, TIMP-1 and PAI-1. These results support the conclusion that TCDD increases CCl{sub 4}-induced liver damage and exacerbates HSC activation, yet collagen deposition and the development of fibrosis may be limited by TCDD-mediated changes in extracellular matrix remodeling. - Highlights: • TCDD increased liver damage and inflammation in mice treated with CCl{sub 4}. • TCDD treatment enhanced markers of hepatic stellate cell activation and

Fecal microbiota transplantation prevents hepatic encephalopathy in rats with carbon tetrachloride-induced acute hepatic dysfunction.

PubMed

Wang, Wei-Wei; Zhang, Yu; Huang, Xiao-Bing; You, Nan; Zheng, Lu; Li, Jing

2017-10-14

To investigate whether fecal microbiota transplantation (FMT) prevents hepatic encephalopathy (HE) in rats with carbon tetrachloride (CCl 4 )-induced acute hepatic dysfunction. A rat model of HE was established with CCl 4 . Rat behaviors and spatial learning capability were observed, and hepatic necrosis, intestinal mucosal barrier, serum ammonia levels and intestinal permeability were determined in HE rats receiving FMT treatment. Furthermore, the expression of tight junction proteins (Claudin-1, Claudin-6 and Occludin), Toll-like receptor (TLR) 4/TLR9, interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α was examined. FMT improved rat behaviors, HE grade and spatial learning capability. Moreover, FMT prevented hepatic necrosis and intestinal mucosal barrier damage, leading to hepatic clearance of serum ammonia levels and reduced intestinal permeability. The expression of TLR4 and TLR9, two potent mediators of inflammatory response, was significantly downregulated in the liver of rats treated with FMT. Consistently, circulating pro-inflammatory factors such as interleukin (IL)-1β, IL-6 and tumor necrosis factor-α were remarkably decreased, indicating that FMT is able to limit systemic inflammation by decreasing the expression of TLR4 and TLR9. Importantly, HE-induced loss of tight junction proteins (Claudin-1, Claudin-6 and Occludin) was restored in intestinal tissues of rats receiving FMT treatment. FMT enables protective effects in HE rats, and it improves the cognitive function and reduces the liver function indexes. FMT may cure HE by altering the intestinal permeability and improving the TLR response of the liver.

Caffeine Suppresses the Activation of Hepatic Stellate Cells cAMP-Independently by Antagonizing Adenosine Receptors.

PubMed

Yamaguchi, Momoka; Saito, Shin-Ya; Nishiyama, Ryota; Nakamura, Misuzu; Todoroki, Kenichiro; Toyo'oka, Toshimasa; Ishikawa, Tomohisa

2017-01-01

During liver injury, hepatic stellate cells (HSCs) are activated by various cytokines and transdifferentiated into myofibroblast-like activated HSCs, which produce collagen, a major source of liver fibrosis. Therefore, the suppression of HSC activation is regarded as a therapeutic target for liver fibrosis. Several epidemiological reports have revealed that caffeine intake decreases the risk of liver disease. In this study, therefore, we investigated the effect of caffeine on the activation of primary HSCs isolated from mice. Caffeine suppressed the activation of HSC in a concentration-dependent manner. BAPTA-AM, an intracellular Ca 2+ chelator, had no effect on the caffeine-induced suppression of HSC activation. None of the isoform-selective inhibitors of phosphodiesterase1 to 5 affected changes in the morphology of HSC during activation, whereas CGS-15943, an adenosine receptor antagonist, inhibited them. Caffeine had no effect on intracellular cAMP level or on the phosphorylation of extracellular signal-regulated kinase (ERK)1/2. In contrast, caffeine significantly decreased the phosphorylation of Akt1. These results suggest that caffeine inhibits HSC activation by antagonizing adenosine receptors, leading to Akt1 signaling activation.

Estradiol inhibits hepatic stellate cell area and collagen synthesis in the chicken liver.

PubMed

Nishimura, Shotaro; Teshima, Akifumi; Kawabata, Fuminori; Tabata, Shoji

2017-11-01

Hepatic stellate cells (HSCs) are the main collagen-producing cells in the liver. The HSC area and amount of collagen fibers are different between male and female chickens. This study was performed to confirm the effect of estradiol on collagen synthesis in the growing chicken liver. Blood estradiol levels in chicks were compared at 4 and 8 weeks of age, and the collagen fibril network in liver tissue was observed at 8 weeks by scanning electron microscopy. Intraperitoneal administrations of estradiol and tamoxifen to male and female chicks, respectively, were performed daily from 5 to 8 weeks of age. The areas of HSCs and collagen contents were measured in the liver tissue. The blood estradiol level was higher in females than in males, and the collagen fibril network was denser in males than in females at 8 weeks of age. Estradiol administration in males induced decreases in the HSC area and collagen content of the liver. Conversely, tamoxifen administration in females induced an increase in the HSC area but did not facilitate collagen synthesis. Based on these results, estradiol inhibits the area and collagen synthesis of HSCs in the growing chicken liver under normal physiological conditions. © 2017 Japanese Society of Animal Science.

Hepatic stellate cell-specific deletion of SIRT1 exacerbates liver fibrosis in mice.

PubMed

Li, Min; Hong, Wenxuan; Hao, Chenzhi; Li, Luyang; Xu, Huihui; Li, Ping; Xu, Yong

2017-12-01

Liver fibrosis is widely perceived as a host defense mechanism that aids tissue repair following liver injury. Excessive fibrogenesis, however, serves to disrupt normal liver structure and precedes such irrevocable human pathologies as cirrhosis and hepatocellular carcinoma. Activation of hepatic stellate cells (HSCs) is a hallmark event during liver fibrosis. In the present study we investigated the mechanism by which the lysine deacetylase SIRT1 regulates HSC activation. We report here that SIRT1 levels were decreased in the liver in different mouse models and in cultured HSCs undergoing activation. SIRT1 down-regulation paralleled HDAC4 up-regulation. HDAC4 was recruited to the SIRT1 promoter during HSC activation and removed acetylated histones H3 and H4 from the SIRT1 promoter leading to SIRT1 trans-repression. HDAC4 silencing restored SIRT1 expression and attenuated HSC activation in SIRT1-dependent manner. More important, selective deletion of SIRT1 in HSCs exacerbated CCl 4 -induced liver fibrosis in mice. Mechanistically, SIRT1 deacetylated PPARγ to block HSC activation. Together, our data reveal an HDAC4-SIRT1-PPARγ axis that contributes to the regulation of HSC activation and liver fibrosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Blocking of SMAD4 expression by shRNA effectively inhibits fibrogenesis of human hepatic stellate cells.

PubMed

Khanizadeh, Sayyad; Ravanshad, Mehrdad; Hosseini, SeyedYounes; Davoodian, Parivash; Nejati Zadeh, Azim; Sarvari, Jamal

2015-01-01

In this study, to clarify the SMAD4 blocking impact on fibrosis process, we investigated its down-regulation by shRNA on activated human LX-2 cell, in vitro. Liver fibrosis is a critical consequence of chronic damage to the liver that can progress toward advanced diseases, liver cirrhosis and hepatocellular carcinoma (HCC). Different SMAD proteins play as major mediators in the fibrogenesis activity of hepatic stellate cells through TGF-β pathways, but the extent of SMAD4 as a co-SMAD protein remained less clear. vector expressing verified shRNA targeting human SMAD4 gene was transfected into LX-2 cells. The GFP expressing plasmid was transfected in the same manner as a control group while leptin treated cells were employed as positive controls. Subsequently, total RNA was extracted and real-time PCR was performed to measure the mRNA levels of SMAD4, COL-1A1, α-SMA, TGF-β and TIMP-1. Furthermore, trypan blue exclusion was performed to test the effect of plasmid transfection and SMAD4 shutting-down on cellular viability. The results indicated that the expression of SMAD4was down-regulated following shRNA transfection intoLX-2 cells (P<0.001). The gene expression analysis of fibrotic genes in LX-2 cells showed that SMAD4 blocking by shRNA significantly reduced the expression level of fibrotic genes when compared to control plasmids (P<0.001). Vector expressing SMAD4-shRNA induced no significant cytotoxic or proliferative effects on LX-2 cells as determined by viability assay (P<0.05). The results of this study suggested that knockdown of SMAD4 expression in stellate cell can control the progression of fibrogenesis through TGF-β pathway blocking.

Effects of Baicalin on Diabetic Cardiac Autonomic Neuropathy Mediated by the P2Y12 Receptor in Rat Stellate Ganglia.

PubMed

Sheng, Xuan; Wang, Jiayue; Guo, Jingjing; Xu, Yurong; Jiang, Huaide; Zheng, Chaoran; Xu, Zixi; Zhang, Yuanruohan; Che, Hongyu; Liang, Shangdong; Zhu, Gaochun; Li, Guilin

2018-01-01

Chronic diabetic hyperglycemia can damage various of organ systems and cause serious complications. Although diabetic cardiac autonomic neuropathy (DCAN) is the primary cause of death in diabetic patients, its pathogenesis remains to be fully elucidated. Baicalin is a flavonoid extracted from Scutellaria baicalensis root and has antibacterial, diuretic, anti-inflammatory, anti- metamorphotic, and antispasmodic effects. Our study explored the effects of baicalin on enhancing sympathoexcitatory response induced by DCAN via the P2Y12 receptor. A type 2 diabetes mellitus rat model was induced by a combination of diet and streptozotocin. Serum epinephrine was measured by enzyme-linked immunosorbent assay. Blood pressure and heart rate were measured using the indirect tail-cuff method. Heart rate variability was analyzed using the frequency-domain of electrocardiogram recordings. The expression levels of P2Y12, interleukin-1beta (IL-1β), tumor necrosis factor alpha (TNF-α), and connexin 43 (Cx43) were determined by quantitative real-time reverse transcription-polymerase chain reaction and western blotting. The interaction between baicalin and P2Y12 determined using by molecular docking. Baicalin alleviated elevated blood pressure and heart rate, improved heart rate variability, and decreased the elevated expression levels of P2Y12, IL-1β, TNF-α, and Cx43 in the stellate ganglia of diabetic rats. Baicalin also reduced the elevated concentration of serum epinephrine and the phosphorylation of p38 mitogen-activated protein kinase in diabetic rats. Baicalin decreases sympathetic activity by inhibiting the P2Y12 receptor in stellate ganglia satellite glial cells to maintain the balance between sympathetic and parasympathetic nerves and relieves DCAN in the rat. © 2018 The Author(s). Published by S. Karger AG, Basel.

Transforming growth factor-beta and platelet-derived growth factor signal via c-Jun N-terminal kinase-dependent Smad2/3 phosphorylation in rat hepatic stellate cells after acute liver injury.

PubMed

Yoshida, Katsunori; Matsuzaki, Koichi; Mori, Shigeo; Tahashi, Yoshiya; Yamagata, Hideo; Furukawa, Fukiko; Seki, Toshihito; Nishizawa, Mikio; Fujisawa, Junichi; Okazaki, Kazuichi

2005-04-01

After liver injury, transforming growth factor-beta (TGF-beta) and platelet-derived growth factor (PDGF) regulate the activation of hepatic stellate cells (HSCs) and tissue remodeling. Mechanisms of PDGF signaling in the TGF-beta-triggered cascade are not completely understood. TGF-beta signaling involves phosphorylation of Smad2 and Smad3 at linker and C-terminal regions. Using antibodies to distinguish Smad2/3 phosphorylated at linker regions from those phosphorylated at C-terminal regions, we investigated Smad2/3-mediated signaling in rat liver injured by CCl(4) administration and in cultured HSCs. In acute liver injury, Smad2/3 were transiently phosphorylated at both regions. Although linker-phosphorylated Smad2 remained in the cytoplasm of alpha-smooth muscle actin-immunoreactive mesenchymal cells adjacent to necrotic hepatocytes in centrilobular areas, linker-phosphorylated Smad3 accumulated in the nuclei. c-Jun N-terminal kinase (JNK) in the activated HSCs directly phosphorylated Smad2/3 at linker regions. Co-treatment of primary cultured HSCs with TGF-beta and PDGF activated the JNK pathway, subsequently inducing endogenous linker phosphorylation of Smad2/3. The JNK pathway may be involved in migration of resident HSCs within the space of Disse to the sites of tissue damage because the JNK inhibitor SP600125 inhibited HSC migration induced by TGF-beta and PDGF signals. Moreover, treatment of HSCs with both TGF-beta and PDGF increased transcriptional activity of plasminogen activator inhibitor-1 through linker phosphorylation of Smad3. In conclusion, TGF-beta and PDGF activate HSCs by transmitting their signals through JNK-mediated Smad2/3 phosphorylation at linker regions, both in vivo and in vitro.

Matrix metalloproteinase-1 induction by diethyldithiocarbamate is regulated via Akt and ERK/miR222/ETS-1 pathways in hepatic stellate cells.

PubMed

Liu, Tianhui; Wang, Ping; Cong, Min; Zhang, Dong; Liu, Lin; Li, Hongyi; Zhai, Qingling; Li, Zhuo; Jia, Jidong; You, Hong

2016-08-01

Matrix metalloproteinase-1 (MMP-1) plays an important role in fibrolysis by degrading excessively deposited collagen I and III. We previously demonstrated that diethyldithiocarbamate (DDC) up-regulates MMP-1 in hepatic stellate cells via the ERK1/2 and Akt signalling pathways. In the current study, we attempted to further explore the molecular mechanisms involved in the regulation of MMP-1. We treated a co-cultured system that included hepatocytes (C3A) and hepatic stellate cells (LX-2) with DDC. The data revealed that the transcriptional factor ETS-1, which is an important regulator of MMP-1, was up-regulated in LX-2 cells following DDC treatment. Furthermore, the up-regulation of MMP-1 by DDC has been abrogated through employing si-ETS-1 to block expression of ETS-1. We found that DDC significantly inhibited the expression of miR-222 in LX-2 cells. We transfected miR-222 mimic into LX-2 cells and then co-cultured the cells with C3A. The up-regulation of ETS-1 and MMP-1 in LX-2 cells treated with DDC were inhibited after miR-222 mimic transfection. These data indicate that DDC up-regulated MMP-1 in LX-2 cells through the miR-222/ETS-1 pathway. Finally, we treated the co-cultured system with an Akt inhibitor (T3830) and an ERK1/2 inhibitor (U0126). Both T3830 and U0126 blocked the suppression of miR-222 by DDC in LX-2. Collectively, these data indicate that DDC up-regulated MMP-1 in LX-2 cells through the Akt and ERK/miR-222/ETS-1 pathways. Our study provides experimental data that will aid the control of the process of fibrolysis in liver fibrosis prevention and treatment. © 2016 The Author(s).

Matrix metalloproteinase-1 induction by diethyldithiocarbamate is regulated via Akt and ERK/miR222/ETS-1 pathways in hepatic stellate cells

PubMed Central

Liu, Tianhui; Wang, Ping; Cong, Min; Zhang, Dong; Liu, Lin; Li, Hongyi; Zhai, Qingling; Li, Zhuo; Jia, Jidong; You, Hong

2016-01-01

Matrix metalloproteinase-1 (MMP-1) plays an important role in fibrolysis by degrading excessively deposited collagen I and III. We previously demonstrated that diethyldithiocarbamate (DDC) up-regulates MMP-1 in hepatic stellate cells via the ERK1/2 and Akt signalling pathways. In the current study, we attempted to further explore the molecular mechanisms involved in the regulation of MMP-1. We treated a co-cultured system that included hepatocytes (C3A) and hepatic stellate cells (LX-2) with DDC. The data revealed that the transcriptional factor ETS-1, which is an important regulator of MMP-1, was up-regulated in LX-2 cells following DDC treatment. Furthermore, the up-regulation of MMP-1 by DDC has been abrogated through employing si-ETS-1 to block expression of ETS-1. We found that DDC significantly inhibited the expression of miR-222 in LX-2 cells. We transfected miR-222 mimic into LX-2 cells and then co-cultured the cells with C3A. The up-regulation of ETS-1 and MMP-1 in LX-2 cells treated with DDC were inhibited after miR-222 mimic transfection. These data indicate that DDC up-regulated MMP-1 in LX-2 cells through the miR-222/ETS-1 pathway. Finally, we treated the co-cultured system with an Akt inhibitor (T3830) and an ERK1/2 inhibitor (U0126). Both T3830 and U0126 blocked the suppression of miR-222 by DDC in LX-2. Collectively, these data indicate that DDC up-regulated MMP-1 in LX-2 cells through the Akt and ERK/miR-222/ETS-1 pathways. Our study provides experimental data that will aid the control of the process of fibrolysis in liver fibrosis prevention and treatment. PMID:27412967

Repopulation of the fibrotic/cirrhotic rat liver by transplanted hepatic stem/progenitor cells and mature hepatocytes

PubMed Central

Yovchev, Mladen I.; Xue, Yuhua; Shafritz, David A.; Locker, Joseph; Oertel, Michael

2013-01-01

Background & Aim Considerable progress has been made in developing anti-fibrotic agents and other strategies to treat liver fibrosis; however, significant long-term restoration of functional liver mass has not yet been achieved. Therefore, we investigated whether transplanted hepatic stem/progenitor cells can effectively repopulate the liver with advanced fibrosis/cirrhosis. Methods Stem/progenitor cells derived from fetal livers or mature hepatocytes from DPPIV+ F344 rats were transplanted into DPPIV− rats with thioacetamide (TAA)-induced fibrosis/cirrhosis; rats were sacrificed 1, 2, or 4 months later. Liver tissues were analyzed by histochemistry, hydroxyproline determination, RT-PCR, and immunohistochemistry. Results After chronic TAA administration, DPPIV− F344 rats exhibited progressive fibrosis, cirrhosis and severe hepatocyte damage. Besides stellate cell activation, increased numbers of stem/progenitor cells (Dlk-1+, AFP+, CD133+, Sox-9+, FoxJ1+) were observed. In conjunction with partial hepatectomy (PH), transplanted stem/progenitor cells engrafted, proliferated competitively compared to host hepatocytes, differentiated into hepatocytic and biliary epithelial cells, and generated new liver mass with extensive long-term liver repopulation (40.8 ± 10.3%). Remarkably, more than 20% liver repopulation was achieved in the absence of PH, associated with reduced fibrogenic activity (e.g., expression of α-SMA, PDGFRβ, desmin, vimentin, TIMP1) and fibrosis (reduced collagen). Furthermore, hepatocytes can also replace liver mass with advanced fibrosis/cirrhosis, but to a lesser extent than FLSPCs. Conclusions This study is a Proof of Principle demonstration that transplanted epithelial stem/progenitor cells can restore injured parenchyma in a liver environment with advanced fibrosis/cirrhosis and exhibit anti-fibrotic effects. PMID:23840008

Cilostazol attenuates cholestatic liver injury and its complications in common bile duct ligated rats.

PubMed

Abdel Kawy, Hala S

2015-04-05

Cilostazol is a phosphodiesterase III inhibitor increases adenosine 3', 5'-cyclic monophosphate (cyclic AMP) level which inhibits hepatic stellate cell activation. Its pharmacological effects include vasodilation, inhibition of vascular smooth muscle cell growth, inhibition of platelet activation and aggregation. The aim of the current study was to determine the effects of early administration of low dose cilostazol on cholestatic liver injury induced by common bile duct ligation (CBDL) in rat. Male Wistar rats (180-200g) were divided into three groups: Group A; simple laparotomy group (sham). Group B; CBDL, Group C; CBDL rats treated with cilostazol (9mg/kg daily for 21 days). Six rats from each group were killed by the end of weeks one and three after surgery, livers and serum were collected for biochemical and histopathological studies. Aspartate aminotransferase, alanine aminotransferase, gama glutamyl transferase, alkaline phosphatase and total bilirubin serum levels decreased in the cilostazol treated rats, when compared with CBDL rats. The hepatic levels of tumor necrosis factor-alpha, transforming growth factor-beta, and platelet derived growth factor-B were significantly lower in cilostazol treated rats than that in CBDL rats. Cilostazol decreased vascular endothelial growth factor level and hemoglobin content in the livers. Cilostazol significantly lowered portal pressure, inhibited ductular proliferation, portal inflammation, hepatic fibrosis and decreased hepatic hydroxyproline contents. Administration of cilostazol in CBDL rats improved hepatic functions, decreased ductular proliferation, ameliorated portal inflammation, lowered portal hypertension and reduced fibrosis. These effects of cilostazol may be useful in the attenuation of liver injury in cholestasis. Copyright © 2015 Elsevier B.V. All rights reserved.

Copper ions stimulate the proliferation of hepatic stellate cells via oxygen stress in vitro.

PubMed

Xu, San-qing; Zhu, Hui-yun; Lin, Jian-guo; Su, Tang-feng; Liu, Yan; Luo, Xiao-ping

2013-02-01

This study examined the effect of copper ions on the proliferation of hepatic stellate cells (HSCs) and the role of oxidative stress in this process in order to gain insight into the mechanism of hepatic fibrosis in Wilson's disease. LX-2 cells, a cell line of human HSCs, were cultured in vitro and treated with different agents including copper sulfate, N-acetyl cysteine (NAC) and buthionine sulfoximine (BSO) for different time. The proliferation of LX-2 cells was measured by non-radioactive cell proliferation assay. Real-time PCR and Western blotting were used to detect the mRNA and protein expression of platelet-derived growth factor receptor β subunit (PDGFβR), ELISA to determine the level of glutathione (GSH) and oxidized glutathione (GSSG), dichlorofluorescein assay to measure the level of reactive oxygen species (ROS), and lipid hydroperoxide assay to quantify the level of lipid peroxide (LPO). The results showed that copper sulfate over a certain concentration range could promote the proliferation of LX-2 cells in a time- and dose-dependent manner. The effect was most manifest when LX-2 cells were treated with copper sulfate at a concentration of 100 μmol/L for 24 h. Additionally, copper sulfate could dose-dependently increase the levels of ROS and LPO, and decrease the ratio of GSH/GSSG in LX-2 cells. The copper-induced increase in mRNA and protein expression of PDGFβR was significantly inhibited in LX-2 cells pre-treated with NAC, a precursor of GSH, and this phenomenon could be reversed by the intervention of BSO, an inhibitor of NAC. It was concluded that copper ions may directly stimulate the proliferation of HSCs via oxidative stress. Anti-oxidative stress therapies may help suppress the copper-induced activation and proliferation of HSCs.

Disruption of transforming growth factor-beta signaling by curcumin induces gene expression of peroxisome proliferator-activated receptor-gamma in rat hepatic stellate cells.

PubMed

Zheng, Shizhong; Chen, Anping

2007-01-01

Activation of hepatic stellate cells (HSC), the major effectors of hepatic fibrogenesis, is coupled with sequential alterations in gene expression, including an increase in receptors for transforming growth factor-beta (TGF-beta) and a dramatic reduction in the peroxisome proliferator-activated receptor-gamma (PPAR-gamma). The relationship between them remains obscure. We previously demonstrated that curcumin induced gene expression of PPAR-gamma in activated HSC, leading to reducing cell proliferation, inducing apoptosis and suppressing expression of extracellular matrix genes. The underlying molecular mechanisms are largely unknown. We recently observed that stimulation of PPAR-gamma activation suppressed gene expression of TGF-beta receptors in activated HSC, leading to the interruption of TGF-beta signaling. This observation supported our assumption of an antagonistic relationship between PPAR-gamma activation and TGF-beta signaling in HSC. In this study, we further hypothesize that TGF-beta signaling might negatively regulate gene expression of PPAR-gamma in activated HSC. The present report demonstrates that exogenous TGF-beta1 inhibits gene expression of PPAR-gamma in activated HSC, which is eliminated by the pretreatment with curcumin likely by interrupting TGF-beta signaling. Transfection assays further indicate that blocking TGF-beta signaling by dominant negative type II TGF-beta receptor increases the promoter activity of PPAR-gamma gene. Promoter deletion assays, site-directed mutageneses, and gel shift assays localize two Smad binding elements (SBEs) in the PPAR-gamma gene promoter, acting as curcumin response elements and negatively regulating the promoter activity in passaged HSC. The Smad3/4 protein complex specifically binds to the SBEs. Overexpression of Smad4 dose dependently eliminates the inhibitory effects of curcumin on the PPAR-gamma gene promoter and TGF-beta signaling. Taken together, these results demonstrate that the interruption of TGF

Hepatic stellate cell and myofibroblast-like cell gene expression in the explanted cirrhotic livers of patients undergoing liver transplantation.

PubMed

Estep, J Michael; O'Reilly, Linda; Grant, Geraldine; Piper, James; Jonsson, Johann; Afendy, Arian; Chandhoke, Vikas; Younossi, Zobair M

2010-02-01

Hepatic stellate cells (HSC) are involved in hepatic fibrogenesis. Cell signaling associated with an insult to the liver affects an HSC transdifferentiation to fibrogenic myofibroblast-like cells. To investigate the transcriptional expression distinguishing HSC and myofibroblast-like cells between livers with and without cirrhosis. Tissue from ten cirrhotic livers (undergoing transplant) and four non-cirrhotic livers from the National Disease Research Interchange underwent cell separation to extract HSC and myofibroblast-like cell populations. Separated cell types as well as LI-90 cells were subjected to microarray analysis. Selected microarray results were verified by quantitative real-time PCR. Differential expression of some genes, such as IL-1beta, IL-1alpha, and IL-6, was associated with both transdifferentiation and disease. Other genes, such as fatty acid 2-hydroxylase only show differential expression in association with disease. Functional analysis supported these findings, indicating some signal transduction pathways (IL-6) are involved in disease and activation, whereas retinoid X receptor signaling in HSC from cirrhotic and non-cirrhotic livers varies in scope and quality. These findings indicate distinct phenotypes for HSC from cirrhotic and non-cirrhotic livers. Furthermore, coordinated differential expression between genes involved in the same signal transduction pathways provides some insight into the mechanisms that may control the balance between fibrogenesis and fibrolysis.

Hepatic mucosal mast cell hyperplasia in rats with secondary biliary cirrhosis.

PubMed

Rioux, K P; Sharkey, K A; Wallace, J L; Swain, M G

1996-04-01

Mast cells have been shown to play a role in many chronic inflammatory and fibrotic disorders. However, their possible contribution to the pathological changes that occur in liver cirrhosis is unknown. To explore this, we examined whether changes in hepatic mast cell number and mediator content were associated with fibrotic changes in experimental biliary cirrhosis. Rats were studied 7, 14, or 21 days after bile duct resection (BDR). Hepatic mast cells were identified by histochemical and immunohistochemical stains. Rat mast cell protease II (RMCP-II), a marker of mast cell degranulation, was measured in liver by enzyme-linked immunosorbent assay. Hepatic collagen deposition was assessed by Sirius Red F3BA staining. In day 21 BDR rats, there was a one- to twofold increase (P < .001) in the number of hepatic mast cells, but this was not observed in day 7 or 14 BDR rats. Mild fibrotic changes were noted in BDR rat livers as early as 7 days after induction of cholestasis. Significant expansion and organization of fibrous tissue had occurred in day 14 BDR rats which progressed to bridging fibrosis by day 21. Liver RMCP-II levels were decreased by 50 percent (P < .05) and mast cell degranulation was apparent as shown by histamine immunostaining. These results suggest that hepatic mast cell hyperplasia and degranulation occur during prolonged cholestasis in the rat. Although these changes do not correlate with the onset of hepatic fibrosis, they do occur at a time during which there is significant deposition and organization extracellular matrix elements. Hepatic mast cells, by releasing profibrogenic mediators, may contribute to fibrotic changes in biliary cirrhosis.

The basic helix-loop-helix transcription factor, heart and neural crest derivatives expressed transcript 2, marks hepatic stellate cells in zebrafish: analysis of stellate cell entry into the developing liver.

PubMed

Yin, Chunyue; Evason, Kimberley J; Maher, Jacquelyn J; Stainier, Didier Y R

2012-11-01

Hepatic stellate cells (HSCs) are liver-specific mesenchymal cells that play vital roles in liver development and injury. Our knowledge of HSC biology is limited by the paucity of in vivo data. HSCs and sinusoidal endothelial cells (SECs) reside in close proximity, and interactions between these two cell types are potentially critical for their development and function. Here, we introduce a transgenic zebrafish line, Tg(hand2:EGFP), that labels HSCs. We find that zebrafish HSCs share many similarities with their mammalian counterparts, including morphology, location, lipid storage, gene-expression profile, and increased proliferation and matrix production, in response to an acute hepatic insult. Using the Tg(hand2:EGFP) line, we conducted time-course analyses during development to reveal that HSCs invade the liver after SECs do. However, HSCs still enter the liver in mutants that lack most endothelial cells, including SECs, indicating that SECs are not required for HSC differentiation or their entry into the liver. In the absence of SECs, HSCs become abnormally associated with hepatic biliary cells, suggesting that SECs influence HSC localization during liver development. We analyzed factors that regulate HSC development and show that inhibition of vascular endothelial growth factor signaling significantly reduces the number of HSCs that enter the liver. We also performed a pilot chemical screen and identified two compounds that affect HSC numbers during development. Our work provides the first comprehensive description of HSC development in zebrafish and reveals the requirement of SECs in HSC localization. The Tg(hand2:EGFP) line represents a unique tool for in vivo analysis and molecular dissection of HSC behavior. Copyright © 2012 American Association for the Study of Liver Diseases.

AQP3 is regulated by PPARγ and JNK in hepatic stellate cells carrying PNPLA3 I148M.

PubMed

Tardelli, Matteo; Bruschi, Francesca V; Claudel, Thierry; Moreno-Viedma, Veronica; Halilbasic, Emina; Marra, Fabio; Herac, Merima; Stulnig, Thomas M; Trauner, Michael

2017-11-07

Aquaglyceroporins (AQPs) allow the movement of glycerol that is required for triglyceride formation in hepatic stellate cells (HSC), as key cellular source of fibrogenesis in the liver. The genetic polymorphism I148M of the patatin-like phospholipase domain-containing 3 (PNPLA3) is associated with hepatic steatosis and its progression to steatohepatitis (NASH), fibrosis and cancer. We aimed to explore the role of AQP3 for HSC activation and unveil its potential interactions with PNPLA3. HSC were isolated from human liver, experiments were performed in primary HSC and human HSC line LX2. AQP3 was the only aquaglyceroporin present in HSC and its expression decreased during activation. The PPARγ agonist, rosiglitazone, recovered AQP3 expression also in PNPLA3 I148M carrying HSC. When PNPLA3 was silenced, AQP3 expression increased. In liver sections from patients with NASH, the decreased amount of AQP3 was proportional to the severity of fibrosis and presence of the PNPLA3 I148M variant. In PNPLA3 I148M cells, the blockade of JNK pathway upregulated AQP3 in synergism with PPARγ. In conclusion, we demonstrated profound reduction of AQP3 in HSC carrying the PNPLA3 I148M variant in parallel to decreased PPARγ activation, which could be rescued by rosiglitazone and blockade of JNK.

Induction of autophagy and apoptosis by miR-148a through the sonic hedgehog signaling pathway in hepatic stellate cells

PubMed Central

Liu, Xu-You; He, Ya-Jun; Yang, Qi-Hong; Huang, Wei; Liu, Zhi-He; Ye, Guo-Rong; Tang, Shao-Hui; Shu, Jian-Chang

2015-01-01

Autophagy is an evolutionarily conserved biological process that is activated in response to stress. Increasing evidence indicate that dysregulated miRNAs significantly contribute to autophagy and are thus implicated in various pathological conditions, including hepatic fibrosis. MiR-148a, a member of the miR-148/152 family, has been found to be downregulated in hepatic fibrosis and human hepatocellular carcinoma. However, the role of miR-148a in the development of hepatic fibrosis remains largely unknown. In this study, we describe the epigenetic regulation of miR-148a and its impact on autophagy in hepatic stellate cells (HSCs), exploring new targets of miR-148a. We found that miR-148a expression was significantly increased under starvation-induced conditions in LX-2 and T-6 cells. In addition, dual-luciferase reporter assays showed that miR-148a suppressed target gene expression by directly interacting with the 3’-untranslated regions (3’-UTRs) of growth arrest-specific gene 1 (Gas1) transcripts. Intriguingly, Gas1, which encodes a Hedgehog surface binding receptor and facilitates the Hedgehog (Hh) signaling pathway, inhibited autophagosome synthesis. Furthermore, we demonstrated a novel function for miR-148a as a potent inducer of autophagy in HSCs. Overexpressing of miR-148a increased autophagic activity, which inhibited proliferation and promoted apoptosis in HSCs. In conclusion, these data support a novel role for miR-148a as a key regulator of autophagy through the Hh signaling pathway, making miR-148a a potential candidate for the development of novel therapeutic strategies. PMID:26609469

GW501516-activated PPARβ/δ promotes liver fibrosis via p38-JNK MAPK-induced hepatic stellate cell proliferation.

PubMed

Kostadinova, Radina; Montagner, Alexandra; Gouranton, Erwan; Fleury, Sébastien; Guillou, Hervé; Dombrowicz, David; Desreumaux, Pierre; Wahli, Walter

2012-10-10

After liver injury, the repair process comprises activation and proliferation of hepatic stellate cells (HSCs), which produce extracellular matrix (ECM) proteins. Peroxisome proliferator-activated receptor beta/delta (PPARβ/δ) is highly expressed in these cells, but its function in liver repair remains incompletely understood. This study investigated whether activation of PPARβ/δ with the ligand GW501516 influenced the fibrotic response to injury from chronic carbon tetrachloride (CCl4) treatment in mice. Wild type and PPARβ/δ-null mice were treated with CCl4 alone or CCl4 co-administered with GW501516. To unveil mechanisms underlying the PPARβ/δ-dependent effects, we analyzed the proliferative response of human LX-2 HSCs to GW501516 in the presence or absence of PPARβ/δ. We found that GW501516 treatment enhanced the fibrotic response. Compared to the other experimental groups, CCl4/GW501516-treated wild type mice exhibited increased expression of various profibrotic and pro-inflammatory genes, such as those involved in extracellular matrix deposition and macrophage recruitment. Importantly, compared to healthy liver, hepatic fibrotic tissues from alcoholic patients showed increased expression of several PPAR target genes, including phosphoinositide-dependent kinase-1, transforming growth factor beta-1, and monocyte chemoattractant protein-1. GW501516 stimulated HSC proliferation that caused enhanced fibrotic and inflammatory responses, by increasing the phosphorylation of p38 and c-Jun N-terminal kinases through the phosphoinositide-3 kinase/protein kinase-C alpha/beta mixed lineage kinase-3 pathway. This study clarified the mechanism underlying GW501516-dependent promotion of hepatic repair by stimulating proliferation of HSCs via the p38 and JNK MAPK pathways.

PNPLA3 has retinyl-palmitate lipase activity in human hepatic stellate cells

PubMed Central

Pirazzi, Carlo; Valenti, Luca; Motta, Benedetta Maria; Pingitore, Piero; Hedfalk, Kristina; Mancina, Rosellina Margherita; Burza, Maria Antonella; Indiveri, Cesare; Ferro, Yvelise; Montalcini, Tiziana; Maglio, Cristina; Dongiovanni, Paola; Fargion, Silvia; Rametta, Raffaela; Pujia, Arturo; Andersson, Linda; Ghosal, Saswati; Levin, Malin; Wiklund, Olov; Iacovino, Michelina; Borén, Jan; Romeo, Stefano

2014-01-01

Retinoids are micronutrients that are stored as retinyl esters in the retina and hepatic stellate cells (HSCs). HSCs are key players in fibrogenesis in chronic liver diseases. The enzyme responsible for hydrolysis and release of retinyl esters from HSCs is unknown and the relationship between retinoid metabolism and liver disease remains unclear. We hypothesize that the patatin-like phospholipase domain-containing 3 (PNPLA3) protein is involved in retinol metabolism in HSCs. We tested our hypothesis both in primary human HSCs and in a human cohort of subjects with non-alcoholic fatty liver disease (N = 146). Here we show that PNPLA3 is highly expressed in human HSCs. Its expression is regulated by retinol availability and insulin, and increased PNPLA3 expression results in reduced lipid droplet content. PNPLA3 promotes extracellular release of retinol from HSCs in response to insulin. We also show that purified wild-type PNPLA3 hydrolyzes retinyl palmitate into retinol and palmitic acid. Conversely, this enzymatic activity is markedly reduced with purified PNPLA3 148M, a common mutation robustly associated with liver fibrosis and hepatocellular carcinoma development. We also find the PNPLA3 I148M genotype to be an independent (P = 0.009 in a multivariate analysis) determinant of circulating retinol-binding protein 4, a reliable proxy for retinol levels in humans. This study identifies PNPLA3 as a lipase responsible for retinyl-palmitate hydrolysis in HSCs in humans. Importantly, this indicates a potential novel link between HSCs, retinoid metabolism and PNPLA3 in determining the susceptibility to chronic liver disease. PMID:24670599

Hepatic inflammation and progressive liver fibrosis in chronic liver disease

PubMed Central

Czaja, Albert J

2014-01-01

Chronic liver inflammation drives hepatic fibrosis, and current immunosuppressive, anti-inflammatory, and anti-viral therapies can weaken this driver. Hepatic fibrosis is reversed, stabilized, or prevented in 57%-79% of patients by conventional treatment regimens, mainly by their anti-inflammatory actions. Responses, however, are commonly incomplete and inconsistently achieved. The fibrotic mechanisms associated with liver inflammation have been clarified, and anti-fibrotic agents promise to improve outcomes as adjunctive therapies. Hepatitis C virus and immune-mediated responses can activate hepatic stellate cells by increasing oxidative stress within hepatocytes. Angiotensin can be synthesized by activated hepatic stellate cells and promote the production of reactive oxygen species. Anti-oxidants (N-acetylcysteine, S-adenosyl-L-methionine, and vitamin E) and angiotensin inhibitors (losartin) have had anti-fibrotic actions in preliminary human studies, and they may emerge as supplemental therapies. Anti-fibrotic agents presage a new era of supplemental treatment for chronic liver disease. PMID:24627588

Endocytosis of collagen by hepatic stellate cells regulates extracellular matrix dynamics

PubMed Central

Bi, Yan; Mukhopadhyay, Dhriti; Drinane, Mary; Ji, Baoan; Li, Xing; Cao, Sheng

2014-01-01

Hepatic stellate cells (HSCs) generate matrix, which in turn may also regulate HSCs function during liver fibrosis. We hypothesized that HSCs may endocytose matrix proteins to sense and respond to changes in microenvironment. Primary human HSCs, LX2, or mouse embryonic fibroblasts (MEFs) [wild-type; c-abl−/−; or Yes, Src, and Fyn knockout mice (YSF−/−)] were incubated with fluorescent-labeled collagen or gelatin. Fluorescence-activated cell sorting analysis and confocal microscopy were used for measuring cellular internalization of matrix proteins. Targeted PCR array and quantitative real-time PCR were used to evaluate gene expression changes. HSCs and LX2 cells endocytose collagens in a concentration- and time-dependent manner. Endocytosed collagen colocalized with Dextran 10K, a marker of macropinocytosis, and 5-ethylisopropyl amiloride, an inhibitor of macropinocytosis, reduced collagen internalization by 46%. Cytochalasin D and ML7 blocked collagen internalization by 47% and 45%, respectively, indicating that actin and myosin are critical for collagen endocytosis. Wortmannin and AKT inhibitor blocked collagen internalization by 70% and 89%, respectively, indicating that matrix macropinocytosis requires phosphoinositide-3-kinase (PI3K)/AKT signaling. Overexpression of dominant-negative dynamin-2 K44A blocked matrix internalization by 77%, indicating a role for dynamin-2 in matrix macropinocytosis. Whereas c-abl−/− MEF showed impaired matrix endocytosis, YSF−/− MEF surprisingly showed increased matrix endocytosis. It was also associated with complex gene regulations that related with matrix dynamics, including increased matrix metalloproteinase 9 (MMP-9) mRNA levels and zymographic activity. HSCs endocytose matrix proteins through macropinocytosis that requires a signaling network composed of PI3K/AKT, dynamin-2, and c-abl. Interaction with extracellular matrix regulates matrix dynamics through modulating multiple gene expressions including MMP-9

Endocytosis of collagen by hepatic stellate cells regulates extracellular matrix dynamics.

PubMed

Bi, Yan; Mukhopadhyay, Dhriti; Drinane, Mary; Ji, Baoan; Li, Xing; Cao, Sheng; Shah, Vijay H

2014-10-01

Hepatic stellate cells (HSCs) generate matrix, which in turn may also regulate HSCs function during liver fibrosis. We hypothesized that HSCs may endocytose matrix proteins to sense and respond to changes in microenvironment. Primary human HSCs, LX2, or mouse embryonic fibroblasts (MEFs) [wild-type; c-abl(-/-); or Yes, Src, and Fyn knockout mice (YSF(-/-))] were incubated with fluorescent-labeled collagen or gelatin. Fluorescence-activated cell sorting analysis and confocal microscopy were used for measuring cellular internalization of matrix proteins. Targeted PCR array and quantitative real-time PCR were used to evaluate gene expression changes. HSCs and LX2 cells endocytose collagens in a concentration- and time-dependent manner. Endocytosed collagen colocalized with Dextran 10K, a marker of macropinocytosis, and 5-ethylisopropyl amiloride, an inhibitor of macropinocytosis, reduced collagen internalization by 46%. Cytochalasin D and ML7 blocked collagen internalization by 47% and 45%, respectively, indicating that actin and myosin are critical for collagen endocytosis. Wortmannin and AKT inhibitor blocked collagen internalization by 70% and 89%, respectively, indicating that matrix macropinocytosis requires phosphoinositide-3-kinase (PI3K)/AKT signaling. Overexpression of dominant-negative dynamin-2 K44A blocked matrix internalization by 77%, indicating a role for dynamin-2 in matrix macropinocytosis. Whereas c-abl(-/-) MEF showed impaired matrix endocytosis, YSF(-/-) MEF surprisingly showed increased matrix endocytosis. It was also associated with complex gene regulations that related with matrix dynamics, including increased matrix metalloproteinase 9 (MMP-9) mRNA levels and zymographic activity. HSCs endocytose matrix proteins through macropinocytosis that requires a signaling network composed of PI3K/AKT, dynamin-2, and c-abl. Interaction with extracellular matrix regulates matrix dynamics through modulating multiple gene expressions including MMP-9

Toll-like receptor 4 mediates inflammatory signaling by bacterial lipopolysaccharide in human hepatic stellate cells.

PubMed

Paik, Yong-Han; Schwabe, Robert F; Bataller, Ramón; Russo, Maria P; Jobin, Christian; Brenner, David A

2003-05-01

Bacterial lipopolysaccharide (LPS) stimulates Kupffer cells and participates in the pathogenesis of alcohol-induced liver injury. However, it is unknown whether LPS directly affects hepatic stellate cells (HSCs), the main fibrogenic cell type in the injured liver. This study characterizes LPS-induced signal transduction and proinflammatory gene expression in activated human HSCs. Culture-activated HSCs and HSCs isolated from patients with hepatitis C virus-induced cirrhosis express LPS-associated signaling molecules, including CD14, toll-like receptor (TLR) 4, and MD2. Stimulation of culture-activated HSCs with LPS results in a rapid and marked activation of NF-kappaB, as assessed by in vitro kinase assays for IkappaB kinase (IKK), IkappaBalpha steady-state levels, p65 nuclear translocation, NF-kappaB-dependent luciferase reporter gene assays, and electrophoretic mobility shift assays. Lipid A induces NF-kappaB activation in a similar manner. Both LPS- and lipid A-induced NF-kappaB activation is blocked by preincubation with either anti-TLR4 blocking antibody (HTA125) or Polymyxin B. Lipid A induces NF-kappaB activation in HSCs from TLR4-sufficient (C3H/OuJ) mice but not from TLR4-deficient (C3H/HeJ) mice. LPS also activates c-Jun N-terminal kinase (JNK), as assessed by in vitro kinase assays. LPS up-regulates IL-8 and MCP-1 gene expression and secretion. LPS-induced IL-8 secretion is completely inhibited by the IkappaB super repressor (Ad5IkappaB) and partially inhibited by a specific JNK inhibitor, SP600125. LPS also up-regulates cell surface expression of ICAM-1 and VCAM-1. In conclusion, human activated HSCs utilize components of TLR4 signal transduction cascade to stimulate NF-kappaB and JNK and up-regulate chemokines and adhesion molecules. Thus, HSCs are a potential mediator of LPS-induced liver injury.

Betaine alleviates hepatic lipid accumulation via enhancing hepatic lipid export and fatty acid oxidation in rats fed with a high-fat diet.

PubMed

Xu, Li; Huang, Danping; Hu, Qiaolin; Wu, Jing; Wang, Yizhen; Feng, Jie

2015-06-28

To assess the effects of betaine on hepatic lipid accumulation and investigate the underlying mechanism, thirty-two male Sprague-Dawley rats weighing 100 (sd 2·50) g were divided into four groups, and started on one of four treatments: basal diet, basal diet with betaine administration, high-fat diet and high-fat diet with betaine administration. The results showed that no significant difference of body weight was found among experimental groups. Compared with high-fat diet-fed rats, a betaine supplementation decreased (P< 0·05) hepatic TAG accumulation induced by high-fat diet, which was also supported by hepatic histology results. Additionally, hepatic betaine-homocysteine methyltransferase concentration [corrected] as well as its mRNA abundance and lecithin level were found increased (P< 0·05) by betaine supplementation in both basal diet-fed rats and high-fat diet-fed rats. Betaine administration in high-fat diet-fed rats exhibited a higher (P< 0·05) concentration [corrected] of hepatic carnitine palmitoyltransferase 1 (CPT1) compared with high-fat diet-fed rats. High-fat diet inhibited (P< 0·05) the gene expression of hepatic PPARα and CPT1. However, betaine administration in high-fat diet-fed rats elevated (P< 0·05) the gene expression of PPARα and CPT1. Moreover, concentration, gene and protein expressions of hepatic fibroblast growth factor 21 (FGF21) were increased (P< 0·05) in response to betaine administration in high-fat diet group; meanwhile the gene expression of hepatic AMP-activated protein kinase was increased (P< 0·05) as well. The results suggest that betaine administration enhanced hepatic lipid export and fatty acid oxidation in high-fat diet-fed rats, thus effectively alleviating fat accumulation in the liver.

Petroselinum crispum extract attenuates hepatic steatosis in rats fed with fructose enriched diet.

PubMed

Nair, V Yuneesha; Balakrishanan, N; Antony Santiago, J Victor

2015-01-01

Non alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and ongoing research efforts are focused on understanding the underlying pathophysiology of hepatic steatosis with the anticipation that these efforts will identify novel therapeutic targets. This study investigated the Petroselinum crispum extract in hepatic steatosis in rats fed with fructose enriched diet. Rats were divided into the 4 groups: Group 1 rats received standard pellet diet with corn starch for the entire experimental period of 8 weeks. Group 2 rats received standard pellet diet and 2 gm/kg body weight crude Parsley leaf ethanol extract for the entire experimental period of 8 weeks. Group 3 rats received modified fructose diet. Group 4 rats received modified fructose diet and 2gm/kg crude Parsley leaf ethanol extract. Hepatic function and structure was evaluated in these rats. Modified fructose diet produced dyslipidemia, hepatic steatosis and infiltration of inflammatory cells in the liver and higher plasma hepatic markers. Petroselinum crispum extract reversed metabolic changes such as abnormal crispum extract attenuated chronic changes in modified fructose diet induced NAFLD (Tab. 2, Fig. 3, Ref. 43).

Effects of raloxifene on portal hypertension and hepatic encephalopathy in cirrhotic rats.

PubMed

Chang, Ching-Chih; Lee, Wen-Shin; Chuang, Chiao-Lin; Hsin, I-Fang; Hsu, Shao-Jung; Chang, Ting; Huang, Hui-Chun; Lee, Fa-Yauh; Lee, Shou-Dong

2017-05-05

Raloxifene, a selective estrogen receptor modulator, has been used extensively for osteoporosis. In addition to the effect of osteoporosis treatment, emerging evidences show that raloxifene affects the vascular function in different tissues. Cirrhosis is characterized with portal hypertension and complicated with hepatic encephalopathy. Portal hypertension affects portal-systemic shunt which leads to hepatic encephalopathy that the vascular modulation might influence severity of hepatic encephalopathy. Herein, we evaluated the impact of raloxifene on bile duct ligation (BDL)-induced cirrhotic rats. The female Sprague-Dawley rats received BDL plus ovariectomy or sham-operation. Four weeks later, rats were divided into 2 subgroups respectively to receive of raloxifene (10mg/kg/day) or saline (vehicle) for 14 days. On the 43th day, motor activities and hemodynamic parameters were measured. Hepatic and vascular mRNA and protein expressions were determined. The histopathological change of liver was examined. We found that the liver biochemistry, ammonia level and motor activity were similar between cirrhotic rats with or without raloxifene administration. The hemodynamic parameters were not significantly different except that raloxifene reduced portal venous inflow. Raloxifene exacerbated hepatic fibrosis and up-regulated hepatic endothelin-1 and cyclooxygenase 2 protein expressions. In addition, raloxifene modulated the mRNA expressions of endothelial nitric oxide synthase, cyclooxygenase and endothelin-1 in the superior mesenteric artery and collateral vessel. In conclusion, raloxifene aggravates hepatic fibrosis and decreases portal venous inflow in cirrhotic rats without adversely affecting portal hypertension and hepatic encephalopathy. The modulation of hepatic and vascular endothelin-1, endothelial nitric oxide synthase and cyclooxygenase expressions may play a role in the mechanism. Copyright © 2017 Elsevier B.V. All rights reserved.

Curcumin eliminates the inhibitory effect of advanced glycation end-products (AGEs) on gene expression of AGE receptor-1 in hepatic stellate cells in vitro

PubMed Central

Lin, Jianguo; Tang, Youcai; Kang, Qiaohua; Chen, Anping

2012-01-01

Diabetes is featured by hyperglycemia, which facilitates the formation of advanced glycation end-products (AGEs). AGEs are a causal factor in development of diabetic complications. AGE receptor-1 (AGE-R1) is responsible for detoxification and clearance of AGEs. Type 2 diabetes mellitus is commonly accompanied by non-alcoholic steatohepatitis, which could cause hepatic fibrosis. Little attention has been paid to effects of AGEs on hepatic fibrogenesis. Curcumin, a phytochemical from turmeric, has been reported to inhibit the activation of hepatic stellate cells (HSCs), the major effectors during hepatic fibrogenesis, and to protect against hepatic fibrogenesis in vitro and in vivo. The current study was designed to evaluate effects of AGEs on inducing HSC activation, to assess the role of curcumin in diminishing the AGE effects and to explore the underlying mechanisms. Our results showed that AGEs stimulated HSC activation by inducing cell proliferation and expression of genes relevant to HSC activation, which were abrogated by curcumin. Curcumin induced gene expression of AGE-R1 in passaged HSCs, which might facilitate the attenuation of the stimulatory effects of AGEs on the activation of HSCs. Further experiments revealed that curcumin inhibited the activity of extracellular signal-regulated kinase (ERK) and induced gene expression and the activity of peroxisome proliferator-activated receptor-gamma (PPARγ), leading to the induction of AGE-R1 gene expression. In summary, AGEs stimulated HSC activation. Curcumin eliminated the AGE effects at least partially by inducing AGE-R1 gene expression. The process was mediated by inhibiting ERK activity, inducing gene expression of PPARγ and stimulating its trans-activity. PMID:22449800

Connective tissue growth factor hammerhead ribozyme attenuates human hepatic stellate cell function

PubMed Central

Gao, Run-Ping; Brigstock, David R

2009-01-01

AIM: To determine the effect of hammerhead ribozyme targeting connective tissue growth factor (CCN2) on human hepatic stellate cell (HSC) function. METHODS: CCN2 hammerhead ribozyme cDNA plus two self-cleaving sequences were inserted into pTriEx2 to produce pTriCCN2-Rz. Each vector was individually transfected into cultured LX-2 human HSCs, which were then stimulated by addition of transforming growth factor (TGF)-β1 to the culture medium. Semi-quantitative RT-PCR was used to determine mRNA levels for CCN2 or collagen I, while protein levels of each molecule in cell lysates and conditioned medium were measured by ELISA. Cell-cycle progression of the transfected cells was assessed by flow cytometry. RESULTS: In pTriEx2-transfected LX-2 cells, TGF-β1 treatment caused an increase in the mRNA level for CCN2 or collagen I, and an increase in produced and secreted CCN2 or extracellular collagen I protein levels. pTriCCN2-Rz-transfected LX-2 cells showed decreased basal CCN2 or collagen mRNA levels, as well as produced and secreted CCN2 or collagen I protein. Furthermore, the TGF-β1-induced increase in mRNA or protein for CCN2 or collagen I was inhibited partially in pTriCCN2-Rz-transfected LX-2 cells. Inhibition of CCN2 using hammerhead ribozyme cDNA resulted in fewer of the cells transitioning into S phase. CONCLUSION: Endogenous CCN2 is a mediator of basal or TGF-β1-induced collagen I production in human HSCs and regulates entry of the cells into S phase. PMID:19673024

PNPLA3 has retinyl-palmitate lipase activity in human hepatic stellate cells.

PubMed

Pirazzi, Carlo; Valenti, Luca; Motta, Benedetta Maria; Pingitore, Piero; Hedfalk, Kristina; Mancina, Rosellina Margherita; Burza, Maria Antonella; Indiveri, Cesare; Ferro, Yvelise; Montalcini, Tiziana; Maglio, Cristina; Dongiovanni, Paola; Fargion, Silvia; Rametta, Raffaela; Pujia, Arturo; Andersson, Linda; Ghosal, Saswati; Levin, Malin; Wiklund, Olov; Iacovino, Michelina; Borén, Jan; Romeo, Stefano

2014-08-01

Retinoids are micronutrients that are stored as retinyl esters in the retina and hepatic stellate cells (HSCs). HSCs are key players in fibrogenesis in chronic liver diseases. The enzyme responsible for hydrolysis and release of retinyl esters from HSCs is unknown and the relationship between retinoid metabolism and liver disease remains unclear. We hypothesize that the patatin-like phospholipase domain-containing 3 (PNPLA3) protein is involved in retinol metabolism in HSCs. We tested our hypothesis both in primary human HSCs and in a human cohort of subjects with non-alcoholic fatty liver disease (N = 146). Here we show that PNPLA3 is highly expressed in human HSCs. Its expression is regulated by retinol availability and insulin, and increased PNPLA3 expression results in reduced lipid droplet content. PNPLA3 promotes extracellular release of retinol from HSCs in response to insulin. We also show that purified wild-type PNPLA3 hydrolyzes retinyl palmitate into retinol and palmitic acid. Conversely, this enzymatic activity is markedly reduced with purified PNPLA3 148M, a common mutation robustly associated with liver fibrosis and hepatocellular carcinoma development. We also find the PNPLA3 I148M genotype to be an independent (P = 0.009 in a multivariate analysis) determinant of circulating retinol-binding protein 4, a reliable proxy for retinol levels in humans. This study identifies PNPLA3 as a lipase responsible for retinyl-palmitate hydrolysis in HSCs in humans. Importantly, this indicates a potential novel link between HSCs, retinoid metabolism and PNPLA3 in determining the susceptibility to chronic liver disease. © The Author 2014. Published by Oxford University Press.

Interleukin-22 ameliorates liver fibrogenesis by attenuating hepatic stellate cell activation and downregulating the levels of inflammatory cytokines

PubMed Central

Lu, Dong-Hong; Guo, Xiao-Yun; Qin, Shan-Yu; Luo, Wei; Huang, Xiao-Li; Chen, Mei; Wang, Jia-Xu; Ma, Shi-Jia; Yang, Xian-Wen; Jiang, Hai-Xing

2015-01-01

AIM: To investigate the effect of interleukin (IL)-22 on hepatic fibrosis in mice and the possible mechanism involved. METHODS: Liver fibrosis was induced in male BALB/c mice by CCl4. Recombinant IL-22 (rmIL-22) was administered intraperitoneally in CCl4-treated mice. Fibrosis was assessed by histology and Masson staining. The activation of hepatic stellate cells (HSCs) was investigated by analysis of α-smooth muscle actin expression. The frequencies of T helper (Th) 22 cells, Th17 cells and Th1 cells, the expression of inflammatory cytokines [IL-22, IL-17A, interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), IL-6, IL-1β] and transcription factors [aryl hydrocarbon receptor (AHR), RAR-related orphan receptor (RORγt), T-bet] mRNA in the liver were investigated. In addition, the plasma levels of IL-22, IL-17A, IFN-γ, TNF-α, IL-6 and IL-1β were evaluated. RESULTS: Significant elevations in circulating Th22 cells, Th17 cells, Th1 cells, IL-22, IL-17A, and IFN-γ were observed in the hepatic fibrosis group compared with the control group (P < 0.01). Treatment with rmIL-22 in mice with hepatic fibrosis ameliorated the severity of hepatic fibrosis, which was confirmed by lower hepatic fibrosis pathological scores (P < 0.01). RmIL-22 decreased the frequencies of Th22 cells (6.71% ± 0.97% vs 8.09% ± 0.74%, P < 0.01), Th17 cells (4.34% ± 0.37% vs 5.71% ± 0.24%, P < 0.01), Th1 cells (3.09% ± 0.49% vs 4.91% ± 0.73%, P < 0.01), and the levels of IL-22 (56.23 ± 3.08 vs 70.29 ± 3.01, P < 0.01), IL-17A (30.74 ± 2.77 vs 45.68 ± 2.71, P < 0.01), and IFN-γ (74.78 ± 2.61 vs 124.89 ± 2.82, P < 0.01). Down-regulation of IL-22, IL-17A, IFN-γ, TNF-α, IL-6, IL-1β, AHR RORγt, and T-bet gene expression in the liver was observed in the rmIL-22 group (P < 0.01). CONCLUSION: The frequencies of Th22, Th17 and Th1 cells are elevated in hepatic fibrosis. RmIL-22 can attenuate HSC activation and down-regulate the levels of inflammatory cytokines, thereby ameliorating

HS-173, a Novel PI3K Inhibitor, Attenuates the Activation of Hepatic Stellate Cells in Liver Fibrosis

PubMed Central

Son, Mi Kwon; Ryu, Ye-Lim; Jung, Kyung Hee; Lee, Hyunseung; Lee, Hee Seung; Yan, Hong Hua; Park, Heon Joo; Ryu, Ji-Kan; Suh, Jun–Kyu; Hong, Sungwoo; Hong, Soon-Sun

2013-01-01

Hepatic stellate cells (HSCs) are the primary source of matrix components in liver disease such as fibrosis. Phosphatidylinositol 3-kinase (PI3K) signaling in HSCs has been shown to induce fibrogenesis. In this study, we evaluated the anti-fibrotic activity of a novel imidazopyridine analogue (HS-173) in human HSCs as well as mouse liver fibrosis. HS-173 strongly suppressed the growth and proliferation of HSCs and induced the arrest at the G2/M phase and apoptosis in HSCs. Furthermore, it reduced the expression of extracellular matrix components such as collagen type I, which was confirmed by an in vivo study. We also observed that HS-173 blocked the PI3K/Akt signaling pathway in vitro and in vivo. Taken together, HS-173 suppressed fibrotic responses such as cell proliferation and collagen synthesis by blocking PI3K/Akt signaling. Therefore, we suggest that this compound may be an effective therapeutic agent for ameliorating liver fibrosis through the inhibition of PI3K signaling. PMID:24326778

Transgenic expression of human neutrophil peptide-1 enhances hepatic fibrosis in mice fed a choline-deficient, L-amino acid-defined diet.

PubMed

Ibusuki, Rie; Uto, Hirofumi; Arima, Shiho; Mawatari, Seiichi; Setoguchi, Yoshiko; Iwashita, Yuji; Hashimoto, Shinichi; Maeda, Takuro; Tanoue, Shiro; Kanmura, Shuji; Oketani, Makoto; Ido, Akio; Tsubouchi, Hirohito

2013-11-01

Neutrophils infiltrate the livers of patients with nonalcoholic steatohepatitis (NASH). Human neutrophil peptides (HNPs) induce cytokine and chemokine production under inflammatory conditions, which may contribute to the progression of NASH. In this study, we focused on the effects of HNP-1 on hepatic steatosis and fibrosis in a mouse model of NASH induced by a choline-deficient, L-amino acid-defined (CDAA) diet. We generated transgenic mice expressing HNP-1 under the control of a β-actin-based promoter. HNP-1 transgenic and wild-type C57BL/6N mice were fed a CDAA diet for 16 weeks to induce hepatic steatosis and fibrosis. Serological and histological features were examined, and the effects of HNP-1 on hepatic stellate cell lines were assessed. HNP-1 transgenic and wild-type mice fed the CDAA diet showed no significant differences in serum alanine aminotransferase levels or the degree of hepatic steatosis based on Oil red O staining and hepatic triglyceride content. In contrast, Sirius Red and Azan staining showed significantly more severe hepatic fibrosis in HNP-1 transgenic mice compared with wild-type mice. In addition, significantly more α-smooth muscle actin-positive hepatic stellate cells were observed in the transgenic mice than in the wild-type mice. Finally, the proliferation of the LI90 hepatic stellate cell line increased in response to HNP-1. Our data indicate that HNP-1 enhances hepatic fibrosis in fatty liver by inducing hepatic stellate cell proliferation. Thus, neutrophil-derived HNP-1 may contribute to the progression of NASH. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

miRNA studies in in vitro and in vivo activated hepatic stellate cells

PubMed Central

Maubach, Gunter; Lim, Michelle Chin Chia; Chen, Jinmiao; Yang, Henry; Zhuo, Lang

2011-01-01

AIM: To understand which and how different miRNAs are implicated in the process of hepatic stellate cell (HSC) activation. METHODS: We used microarrays to examine the differential expression of miRNAs during in vitro activation of primary HSCs (pHSCs). The transcriptome changes upon stable transfection of rno-miR-146a into an HSC cell line were studied using cDNA microarrays. Selected differentially regulated miRNAs were investigated by quantitative real-time polymerase chain reaction during in vivo HSC activation. The effect of miRNA mimics and inhibitor on the in vitro activation of pHSCs was also evaluated. RESULTS: We found that 16 miRNAs were upregulated and 26 were downregulated significantly in 10-d in vitro activated pHSCs in comparison to quiescent pHSCs. Overexpression of rno-miR-146a was characterized by marked upregulation of tissue inhibitor of metalloproteinase-3, which is implicated in the regulation of tumor necrosis factor-α activity. Differences in the regulation of selected miRNAs were observed comparing in vitro and in vivo HSC activation. Treatment with miR-26a and 29a mimics, and miR-214 inhibitor during in vitro activation of pHSCs induced significant downregulation of collagen type I transcription. CONCLUSION: Our results emphasize the different regulation of miRNAs in in vitro and in vivo activated pHSCs. We also showed that miR-26a, 29a and 214 are involved in the regulation of collagen type I mRNA. PMID:21734783

TGF-beta1 modulates matrix metalloproteinase-13 expression in hepatic stellate cells by complex mechanisms involving p38MAPK, PI3-kinase, AKT, and p70S6k.

PubMed

Lechuga, Carmen G; Hernández-Nazara, Zamira H; Domínguez Rosales, José-Alfredo; Morris, Elena R; Rincón, Ana Rosa; Rivas-Estilla, Ana María; Esteban-Gamboa, Andrés; Rojkind, Marcos

2004-11-01

Transforming growth factor-beta1 (TGF-beta1), the main cytokine involved in liver fibrogenesis, induces expression of the type I collagen genes in hepatic stellate cells by a transcriptional mechanism, which is hydrogen peroxide and de novo protein synthesis dependent. Our recent studies have revealed that expression of type I collagen and matrix metalloproteinase-13 (MMP-13) mRNAs in hepatic stellate cells is reciprocally modulated. Because TGF-beta1 induces a transient elevation of alpha1(I) collagen mRNA, we investigated whether this cytokine was able to induce the expression of MMP-13 mRNA during the downfall of the alpha1(I) collagen mRNA. In the present study, we report that TGF-beta1 induces a rapid decline in steady-state levels of MMP-13 mRNA at the time that it induces the expression of alpha1(I) collagen mRNA. This change in MMP-13 mRNA expression occurs within the first 6 h postcytokine administration and is accompanied by a twofold increase in gene transcription and a fivefold decrease in mRNA half-life. This is followed by increased expression of MMP-13 mRNA, which reaches maximal values by 48 h. Our results also show that this TGF-beta1-mediated effect is de novo protein synthesis-dependent and requires the activity of p38MAPK, phosphatidylinositol 3-kinase, AKT, and p70(S6k). Altogether, our data suggest that regulation of MMP-13 by TGF-beta1 is a complex process involving transcriptional and posttranscriptional mechanisms.

The effects of tramadol on hepatic ischemia/reperfusion injury in rats.

PubMed

Mahmoud, Mona F; Gamal, Samar; Shaheen, Mohamed A; El-Fayoumi, Hassan M

2016-01-01

Tramadol is a centrally acting synthetic analgesic. It has a cardioprotective effect against myocardial ischemia-reperfusion (I/R) injury in isolated rat heart. We hypothesized that tramadol may exert a similar protective effect on hepatic I/R injury. Hence, the current investigation was designed to study the possible protective effects of tramadol on experimentally-induced hepatic I/R injury in rats. Tramadol was administered 30 min before ischemia following which the rats were subjected to 45 min of ischemia followed by 1 h of reperfusion. Tramadol attenuated hepatic injury induced by I/R as evidenced by the reduction of transaminases, structural changes, and apoptotic cell death. It decreased the level of inflammatory markers such as tumor necrosis factor-alpha (TNF-α), TNF-α/interleukin-10 (IL-10) ratio, and nuclear factor-κB gene expression. It also increased the anti-inflammatory cytokine, IL-10 levels in hepatic tissues. Furthermore, it reduced oxidative stress parameters except manganese superoxide dismutase activity. The results suggest that tramadol has hepatoprotective effects against hepatic I/R injury via anti-inflammatory, antiapoptotic, and antioxidant effects.

Astragaloside Alleviates Hepatic Fibrosis Function via PAR2 Signaling Pathway in Diabetic Rats.

PubMed

Wang, Zhenchang; Li, Quanqiang; Xiang, Mingpeng; Zhang, Fengying; Wei, Dongyu; Wen, Zhixi; Zhou, Ying

2017-01-01

Astragaloside (AGS) extracted from radix astragalin (Huangqi) has been considered to be beneficial to liver diseases. In this study, we examined the role played by AGS in alleviating hepatic fibrosis function via protease-activated receptor-2 (PAR2) mechanisms. We hypothesized that AGS affects PAR2 signaling pathway thereby improving hepatic function in rats with hepatic fibrosis induced by carbon tetrachloride (CCl4). We further hypothesized that AGS attenuates impaired hepatic function evoked by CCl4 to a greater degree in diabetic animals. ELISA and Western Blot analysis were used to examine PAR2 signaling pathway in diabetic CCl4-rats and non-diabetic CCl4-rats. AGS inhibited the protein expression of PAR2 and its downstream pathway PKA and PKCɛ in CCl4-rats. Notably, the effects of AGS were greater in CCl4-rats with diabetes. AGS also significantly attenuated the CCl4-induced upregulations of pro-inflammatory cytokines, namely interleukin-1β, interleukin-6 and tumor necrosis factor-α accompanied with decreases of collagenic parameters such as hexadecenoic acid, laminin and hydroxyproline. Additionally, AGS improved the CCl4-induced exaggerations of liver index and functions including alanine aminotransferase, aspartate aminotransferase. Moreover, TGF-β1, a marker of hepatic fibrosis, was increased in CCl4-rats and AGS inhibited increases in TGF-β1 induced by CCl4. AGS alleviates hepatic fibrosis by inhibiting PAR2 signaling expression and its effects are largely enhanced in diabetic animals. Targeting one or more of these signaling molecules may present new opportunities for treatment and management of hepatic fibrosis; and results of our study are likely to shed light on strategies for application of AGS because it has potentially greater therapeutic effectiveness for hepatic fibrosis in diabetes. © 2017 The Author(s)Published by S. Karger AG, Basel.

Hepatic uptake of amino acids in late-pregnant rats. Effect of food deprivation.

PubMed Central

Casado, J; Remesar, X; Pastor-Anglada, M

1987-01-01

Hepatic availability, uptake and fractional extraction of amino acids were estimated in anaesthetized 21-day-pregnant and age-matched virgin rats, either fed or after 24 h starvation. Amino acid availability was unaltered in fed pregnant rats as compared with fed virgin controls. However, the hepatic uptake of these compounds was higher in the former than in the latter. These adaptations were mediated by an increase in the hepatic capability to take up amino acids in late-pregnant rats, as reflected by the changes found for the fractional extraction rates. The decrease in amino acid availability found after starvation was more pronounced in pregnant than in virgin rats. Nevertheless, the hepatic uptake was similar in both groups. These results indicate that amino acids are not limiting for ureagenesis during late pregnancy, strongly suggesting that the mechanism(s) which modulate urea synthesis may be intracellular in origin. PMID:3435433

Accretion of visceral fat and hepatic insulin resistance in pregnant rats.

PubMed

Einstein, Francine H; Fishman, Sigal; Muzumdar, Radhika H; Yang, Xiao Man; Atzmon, Gil; Barzilai, Nir

2008-02-01

Insulin resistance (IR) is a hallmark of pregnancy. Because increased visceral fat (VF) is associated with IR in nonpregnant states, we reasoned that fat accretion might be important in the development of IR during pregnancy. To determine whether VF depots increase in pregnancy and whether VF contributes to IR, we studied three groups of 6-mo-old female Sprague-Dawley rats: 1) nonpregnant sham-operated rats (Nonpreg; n = 6), 2) pregnant sham-operated rats (Preg; n = 6), and 3) pregnant rats in which VF was surgically removed 1 mo before mating (PVF-; n = 6). VF doubled by day 19 of pregnancy (Nonpreg 5.1 +/- 0.3, Preg 10.0 +/- 1.0 g, P < 0.01), and PVF- had similar amounts of VF compared with Nonpreg (PVF- 4.6 +/- 0.8 g). Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp in late gestation in chronically catheterized unstressed rats. Glucose IR (mg.kg(-1).min(-1)) was highest in Nonpreg (19.4 +/- 2.0), lowest in Preg (11.1 +/- 1.4), and intermediate in PVF- (14.7 +/- 0.6; P < 0.001 between all groups). During the clamp, Nonpreg had greater hepatic insulin sensitivity than Preg [hepatic glucose production (HGP): Nonpreg 4.5 +/- 1.3, Preg 9.3 +/- 0.5 mg.kg(-1).min(-1); P < 0.001]. With decreased VF, hepatic insulin sensitivity was similar to nonpregnant levels in PVF- (HGP 4.9 +/- 0.8 mg.kg(-1).min(-1)). Both pregnant groups had lower peripheral glucose uptake compared with Nonpreg. In parallel with hepatic insulin sensitivity, hepatic triglyceride content was increased in pregnancy (Nonpreg 1.9 +/- 0.4 vs. Preg 3.2 +/- 0.3 mg/g) and decreased with removal of VF (PVF- 1.3 +/- 0.4 mg/g; P < 0.05). Accretion of visceral fat is an important component in the development of hepatic IR in pregnancy, and accumulation of hepatic triglycerides is a mechanism by which visceral fat may modulate insulin action in pregnancy.

The effects of tramadol on hepatic ischemia/reperfusion injury in rats

PubMed Central

Mahmoud, Mona F.; Gamal, Samar; Shaheen, Mohamed A.; El-Fayoumi, Hassan M.

2016-01-01

Objectives: Tramadol is a centrally acting synthetic analgesic. It has a cardioprotective effect against myocardial ischemia-reperfusion (I/R) injury in isolated rat heart. We hypothesized that tramadol may exert a similar protective effect on hepatic I/R injury. Hence, the current investigation was designed to study the possible protective effects of tramadol on experimentally-induced hepatic I/R injury in rats. Materials and Methods: Tramadol was administered 30 min before ischemia following which the rats were subjected to 45 min of ischemia followed by 1 h of reperfusion. Results: Tramadol attenuated hepatic injury induced by I/R as evidenced by the reduction of transaminases, structural changes, and apoptotic cell death. It decreased the level of inflammatory markers such as tumor necrosis factor-alpha (TNF-α), TNF-α/interleukin-10 (IL-10) ratio, and nuclear factor-κB gene expression. It also increased the anti-inflammatory cytokine, IL-10 levels in hepatic tissues. Furthermore, it reduced oxidative stress parameters except manganese superoxide dismutase activity. Conclusion: The results suggest that tramadol has hepatoprotective effects against hepatic I/R injury via anti-inflammatory, antiapoptotic, and antioxidant effects. PMID:27298497

Adenoviral overexpression of Lhx2 attenuates cell viability but does not preserve the stem cell like phenotype of hepatic stellate cells.

PubMed

Genz, Berit; Thomas, Maria; Pützer, Brigitte M; Siatkowski, Marcin; Fuellen, Georg; Vollmar, Brigitte; Abshagen, Kerstin

2014-11-01

Hepatic stellate cells (HSC) are well known initiators of hepatic fibrosis. After liver cell damage, HSC transdifferentiate into proliferative myofibroblasts, representing the major source of extracellular matrix in the fibrotic organ. Recent studies also demonstrate a role of HSC as progenitor or stem cell like cells in liver regeneration. Lhx2 is described as stem cell maintaining factor in different organs and as an inhibitory transcription factor in HSC activation. Here we examined whether a continuous expression of Lhx2 in HSC could attenuate their activation and whether Lhx2 could serve as a potential target for antifibrotic gene therapy. Therefore, we evaluated an adenoviral mediated overexpression of Lhx2 in primary HSC and investigated mRNA expression patterns by qRT-PCR as well as the activation status by different in vitro assays. HSC revealed a marked increase in activation markers like smooth muscle actin alpha (αSMA) and collagen 1α independent from adenoviral transduction. Lhx2 overexpression resulted in attenuated cell viability as shown by a slightly hampered migratory and contractile phenotype of HSC. Expression of stem cell factors or signaling components was also unaffected by Lhx2. Summarizing these results, we found no antifibrotic or stem cell maintaining effect of Lhx2 overexpression in primary HSC. Copyright © 2014 Elsevier Inc. All rights reserved.

Dietary sea cucumber cerebroside alleviates orotic acid-induced excess hepatic adipopexis in rats

PubMed Central

2012-01-01

Background Nonalcoholic fatty liver disease (NAFLD) is a prevalent chronic liver disease in industrialized countries. The present study was undertaken to explore the preventive effect of dietary sea cucumber cerebroside (SCC) extracted from Acaudina molpadioides in fatty liver rats. Methods Male Wistar rats were randomly divided into four groups including normal control group, NAFLD model group, and two SCC-treated groups with SCC at 0.006% and 0.03% respectively. The fatty liver model was established by administration of 1% orotic acid (OA) to the rats. After 10d, serum and hepatic lipid levels were detected. And the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were also determined. Besides, to gain the potential mechanism, the changes of key enzymes and gene expressions related to the hepatic lipid metabolism were measured. Results Dietary SCC at the level of 0.006% and 0.03% ameliorated the hepatic lipid accumulation in fatty liver rats. SCC administration elevated the serum triglyceride (TG) level and the ALT, AST activities in OA-fed rats. The activities of hepatic lipogenic enzymes including fatty acid synthase (FAS), malic enzyme (ME) and glucose-6-phosphatedehydrogenase (G6PDH) were inhibited by SCC treatment. And the gene expressions of FAS, ME, G6PDH and sterol-regulatory element binding protein (SREBP-1c) were also reduced in rats fed SCC. However, dietary SCC didn't affect the activity and mRNA expression of carnitine palmitoyltransferase (CPT) in liver. Besides, suppression of microsomal triglyceride transfer protein (MTP) activity was observed in SCC-feeding rats. Conclusions These results suggested that dietary SCC could attenuate hepatic steatosis due to its inhibition of hepatic lipogenic gene expression and enzyme activity and the enhancement of TG secretion from liver. PMID:22569330

Carbonated soft drinks alter hepatic cytochrome P450 isoform expression in Wistar rats.

PubMed

Alkhedaide, Adel; Soliman, Mohamed Mohamed; Ibrahim, Zein Shaban

2016-11-01

The aim of the current study was to examine the effects of chronic consumption of soft drinks (SDs) on hepatic oxidative stress and cytochrome P450 enzymes (CYPs) expression in the livers of Wistar rats. For 3 consecutive months, the rats had free access to three different soft drinks, Coca-Cola, Pepsi-Cola and 7-UP. The rats were subsequently compared with control group rats that had consumed water. Blood and hepatic tissue samples were assayed for the changes in antioxidants, liver function biomarkers and hepatic gene expression for different isoforms of hepatic CYP. The results indicated that SD consumption (SDC) decreased serum antioxidant levels and increased malondialdehyde secretion, and increased liver biomarkers (glutamate pyruvate transaminase and glutamate oxaloacetate). SD induced alterations in mRNA expression of hepatic antioxidants and cytochrome isoforms. The expression of peroxidase, catalase, CYP1A2, CYP3A2 and CYP2C11 in the liver were upregulated following SDC. By contrast, CYP2B1 was downregulated after 3 months of SDC in liver tissue samples. Thus, the present findings indicate that SDs induced oxidative stress in the liver of Wistar rats and for the first time, to the best of our knowledge, indicate that SDC disrupts hepatic CYP enzymes that may affect drug metabolism. Therefore, drug-dosing programs should be carefully designed to take these novel findings into consideration for the treatment of diseases.

Carbonated soft drinks alter hepatic cytochrome P450 isoform expression in Wistar rats

PubMed Central

Alkhedaide, Adel; Soliman, Mohamed Mohamed; Ibrahim, Zein Shaban

2016-01-01

The aim of the current study was to examine the effects of chronic consumption of soft drinks (SDs) on hepatic oxidative stress and cytochrome P450 enzymes (CYPs) expression in the livers of Wistar rats. For 3 consecutive months, the rats had free access to three different soft drinks, Coca-Cola, Pepsi-Cola and 7-UP. The rats were subsequently compared with control group rats that had consumed water. Blood and hepatic tissue samples were assayed for the changes in antioxidants, liver function biomarkers and hepatic gene expression for different isoforms of hepatic CYP. The results indicated that SD consumption (SDC) decreased serum antioxidant levels and increased malondialdehyde secretion, and increased liver biomarkers (glutamate pyruvate transaminase and glutamate oxaloacetate). SD induced alterations in mRNA expression of hepatic antioxidants and cytochrome isoforms. The expression of peroxidase, catalase, CYP1A2, CYP3A2 and CYP2C11 in the liver were upregulated following SDC. By contrast, CYP2B1 was downregulated after 3 months of SDC in liver tissue samples. Thus, the present findings indicate that SDs induced oxidative stress in the liver of Wistar rats and for the first time, to the best of our knowledge, indicate that SDC disrupts hepatic CYP enzymes that may affect drug metabolism. Therefore, drug-dosing programs should be carefully designed to take these novel findings into consideration for the treatment of diseases. PMID:27882225

Receptor channel TRPC6 orchestrate the activation of human hepatic stellate cell under hypoxia condition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iyer, Soumya C, E-mail: chidambaram.soumya@gmail.com; Kannan, Anbarasu; Gopal, Ashidha

2015-08-01

Hepatic stellate cells (HSCs), a specialized stromal cytotype have a great impact on the biological behaviors of liver diseases. Despite this fact, the underlying mechanism that regulates HSC still remains poorly understood. The aim of the present study was to understand the role of TRPC6 signaling in regulating the molecular mechanism of HSCs in response to hypoxia. In the present study we showed that under hypoxia condition, the upregulated Hypoxia Inducible Factor 1α (HIF1α) increases NICD activation, which in turn induces the expression of transient receptor potential channel 6 (TRPC6) in HSC line lx-2. TRPC6 causes a sustained elevation ofmore » intracellular calcium which is coupled with the activation of the calcineurin-nuclear factor of activated T-cell (NFAT) pathway which activates the synthesis of extracellular matrix proteins. TRPC6 also activates SMAD2/3 dependent TGF-β signaling in facilitating upregulated expression of αSMA and collagen. As activated HSCs may be a suitable target for HCC therapy and targeting these cells rather than the HCC cells may result in a greater response. Collectively, our studies indicate for the first time the detailed mechanism of activation of HSC through TRPC6 signaling and thus being a promising therapeutic target. - Highlights: • HIF1α increases NICD, induces TRPC6 in lx2 cells. • TRPC6 a novel regulator in the activation of HSC. • HSCs as target for HCC therapy.« less

Hepatic lesions in 90 captive nondomestic felids presented for autopsy.

PubMed

Bernard, J M; Newkirk, K M; McRee, A E; Whittemore, J C; Ramsay, E C

2015-03-01

Hepatic lesions in nondomestic felids are poorly characterized. The purpose of this study was to evaluate hepatic lesions in 90 captive, nondomestic felids including tigers, cougars, and lions. Hepatic lesions were histologically characterized as vacuolar change (lipidosis or glycogenosis), biliary cysts, biliary hyperplasia, hepatitis, necrosis, neoplasia, fibrosis, veno-occlusive disease, cholestasis, hematoma, congestion, or hemorrhage. Stepwise logistic regression analyses were performed for vacuolar change, benign biliary lesions, hepatitis, lipogranulomas, extramedullary hematopoiesis, and hepatic stellate cell hypertrophy and hyperplasia, with species as the outcome variable. Ninety cats met the inclusion criteria. Seventy livers (78%) contained 1 or more lesions. Hepatocellular vacuolar change (41/90 [46%]) was the most common lesion overall. Extramedullary hematopoiesis, lipogranulomas, and hepatic stellate cell hyperplasia were also common. One snow leopard had veno-occlusive disease. Tigers were more likely than other felids to have no significant hepatic histologic lesions (odds ratio [OR], 12.687; P = .002), and lions were more likely to have biliary cysts (OR, 5.97; P = .021). Six animals (7%) died of hepatic disease: cholangiocellular carcinoma (n = 2) and 1 each of hepatic lipidosis, hepatocellular necrosis, pyogranulomatous hepatitis, and suppurative cholecystitis. Hepatocellular iron and copper accumulations were present in 72 of 90 (80%) and 10 of 90 (11%) sections, respectively. Sinusoidal fibrosis was common (74/90 [82%]) and primarily centrilobular (65/74 [88%]). Hepatocellular iron, copper, and fibrosis were not significantly associated with hepatic lesions. Primary hepatic disease was not a common cause of death in nondomestic felids in this study. © The Author(s) 2014.

Vitamin K1 attenuates bile duct ligation-induced liver fibrosis in rats.

PubMed

Jiao, Kun; Sun, Quan; Chen, Baian; Li, Shengli; Lu, Jing

2014-06-01

Vitamin K1 is used as a liver protection drug for cholestasis-induced liver fibrosis in China, but the mechanism of vitamin K1's action in liver fibrosis is unclear. In this study, a model of liver fibrosis was achieved via bile duct ligation in rats. The rats were then injected with vitamin K1, and the levels of serum aspartate aminotransferase, alanine transaminase, total bilirubin and the fibrotic grade score, collagen content, the expressions of α-smooth muscle actin (SMA) and cytokeratin 19 (CK19) were measured on day 28 after ligation. The levels of the biochemical parameters, fibrotic score and collagen content were significantly reduced by treatment with vitamin K1 in bile duct-ligated rats. In addition, α-SMA and CK19 expression was significantly reduced by vitamin K1 treatment in bile duct-ligated rats. These results suggested that vitamin K1 may attenuate liver fibrosis by inhibiting hepatic stellate cell activation in bile duct-ligated rats.

[The effect of urokinase on hepatic fibrogenesis in rats].

PubMed

Wu, Xi-run; Wang, Qi; Wang, Ling; Shi, Shui-sheng; Guo, Wen-dong

2009-12-01

To investigate the effect of urokinase on hepatic fibrogenesis in rats. Hepatic fibrosis was induced in rats by complex pathogenic factors including subcutaneous injections of carbon tetrachloride, alcohol and cholesterol feeding. Animals were randomly divided into 3 groups: normal control group, hepatic fibrosis group (complex pathogenic factors for 6 weeks), UK prevention group (complex pathogenic factors+UK for 6 weeks). The animals were sacrificed at the end of week 6. The expression of alpha-SMA, uPA, PAI-1, TGFb1, TIMP-1, collagen type I and type III proteins in hepatic fibrosis tissue was detected by immunohistochemistry, the expression of PAI-1 and TGFb1 mRNA in the hepatic fibrosis tissue was quantified by real time RT-PCR. The serum levels of hyaluronicacid (HA), alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin (TBil) and the content of liver hydroxyproline (Hyp) were detected using ELISA kits. The serum ALT, AST, TBil, HA and the content of liver Hyp were (46.66+/-6.30) U/L, (126.26+/-31.65) U/L, (31.11+/-4.20) micromol/L, (109.70+/-18.81) microg/L and (0.98+/-0.09) mg/(g liver), respectively, in UK prevention group, which were significantly lower than those [(101.57+/-11.97) U/L, (205.89+/-56.26) U/L, (67.75+/-2.75) micromol/L, (184.43+/-32.36) microg/L and (1.65+/-0.16) mg/(g liver), respectively] in hepatic fibrosis group (q = 3.3801-20.0061, P < 0.01). The levels of a-SMA, collagen type I, type III, TIMP-1, PAI-1, TGFb1 proteins were (299.27+/-37.36), (210.05+/-27.17), (192.94+/-24.48), (213.70+/-32.21), (204.25+/-17.92), (205.97+/-23.81), respectively, in UK prevention group, which were significantly lower than those [(418.83+/-30.21), (323.77+/-21.53), (302.37+/-31.43), (376.63+/-25.19), (313.53+/-26.67) and (327.42+/-36.75), respectively] in hepatic fibrosis group. The level of uPA protein was increased, and the expression of PAI-1, TGFb1 mRNA in hepatic fibrosis tissue was decreased in UK prevention group. In the early

Basis of aggravated hepatic lipid metabolism by chronic stress in high-fat diet-fed rat.

PubMed

Han, Ying; Lin, Min; Wang, Xiaobin; Guo, Keke; Wang, Shanshan; Sun, Mengfei; Wang, Jiao; Han, Xiaoyu; Fu, Ting; Hu, Yang; Fu, Jihua

2015-03-01

Our previous study has demonstrated that long-term stress, known as chronic stress (CS), can aggravate nonalcoholic fatty liver disease in high-fat diet (HFD)-fed rat. In this study, we tried to figure out which lipid metabolic pathways were impacted by CS in the HFD-fed rat. Male Sprague-Dawley rats (6 weeks of age, n = 8 per group) were fed with either standard diet or HFD with or without CS exposure for 8 weeks. Hepatic lipidosis, biochemical, hormonal, and lipid profile markers in serum and liver, and enzymes involved in de novo lipogenesis (DNL) of fatty acids (FAs) and cholesterol, β-oxidation, FAs uptake, triglycerides synthesis, and very low-density lipoprotein (VLDL) assembly in the liver were detected. CS exposure reduced hepatic lipidosis but further elevated hepatic VLDL content with aggravated dyslipidemia in the HFD-fed rats. There was a synergism between CS and HFD on VLDL production and dyslipidemia. PCR and western blot assays showed that CS exposure significantly promoted hepatic VLDL assembly in rats, especially in the HFD-fed rats, while it had little impact on DNL, β-oxidation, FAs uptake, and triglycerides synthesis in the HFD-fed rats. This phenomenon was in accordance with elevated serum glucocorticoid level. The critical influence of CS exposure on hepatic lipid metabolism in the HFD-fed rats is VLDL assembly which might be regulated by glucocorticoid.

Gallic acid ameliorates hyperglycemia and improves hepatic carbohydrate metabolism in rats fed a high-fructose diet.

PubMed

Huang, Da-Wei; Chang, Wen-Chang; Wu, James Swi-Bea; Shih, Rui-Wen; Shen, Szu-Chuan

2016-02-01

Herein, we investigated the hypoglycemic effect of plant gallic acid (GA) on glucose uptake in an insulin-resistant cell culture model and on hepatic carbohydrate metabolism in rats with a high-fructose diet (HFD)-induced diabetes. Our hypothesis is that GA ameliorates hyperglycemia via alleviating hepatic insulin resistance by suppressing hepatic inflammation and improves abnormal hepatic carbohydrate metabolism by suppressing hepatic gluconeogenesis and enhancing the hepatic glycogenesis and glycolysis pathways in HFD-induced diabetic rats. Gallic acid increased glucose uptake activity by 19.2% at a concentration of 6.25 μg/mL in insulin-resistant FL83B mouse hepatocytes. In HFD-induced diabetic rats, GA significantly alleviated hyperglycemia, reduced the values of the area under the curve for glucose in an oral glucose tolerance test, and reduced the scores of the homeostasis model assessment of insulin resistance index. The levels of serum C-peptide and fructosamine and cardiovascular risk index scores were also significantly decreased in HFD rats treated with GA. Moreover, GA up-regulated the expression of hepatic insulin signal transduction-related proteins, including insulin receptor, insulin receptor substrate 1, phosphatidylinositol-3 kinase, Akt/protein kinase B, and glucose transporter 2, in HFD rats. Gallic acid also down-regulated the expression of hepatic gluconeogenesis-related proteins, such as fructose-1,6-bisphosphatase, and up-regulated expression of hepatic glycogen synthase and glycolysis-related proteins, including hexokinase, phosphofructokinase, and aldolase, in HFD rats. Our findings indicate that GA has potential as a health food ingredient to prevent diabetes mellitus. Copyright © 2016 Elsevier Inc. All rights reserved.

The PNPLA3 I148M variant modulates the fibrogenic phenotype of human hepatic stellate cells.

PubMed

Bruschi, Francesca Virginia; Claudel, Thierry; Tardelli, Matteo; Caligiuri, Alessandra; Stulnig, Thomas M; Marra, Fabio; Trauner, Michael

2017-06-01

The genetic polymorphism I148M of patatin-like phospholipase domain-containing 3 (PNPLA3) is robustly associated with hepatic steatosis and its progression to steatohepatitis, fibrosis, and cancer. Hepatic stellate cells (HSCs) are key players in the development of liver fibrosis, but the role of PNPLA3 and its variant I148M in this process is poorly understood. Here we analyzed the expression of PNPLA3 during human HSC activation and thereby explored how a PNPLA3 variant impacts hepatic fibrogenesis. We show that expression of PNPLA3 gene and protein increases during the early phases of activation and remains elevated in fully activated HSCs (P < 0.01). Knockdown of PNPLA3 significantly decreases the profibrogenic protein alpha-smooth muscle actin (P < 0.05). Primary human I148M HSCs displayed significantly higher expression and release of proinflammatory cytokines, such as chemokine (C-C motif) ligand 5 (P < 0.01) and granulocyte-macrophage colony-stimulating factor (P < 0.001), thus contributing to migration of immune cells (P < 0.05). Primary I148M HSCs showed reduced retinol (P < 0.001) but higher lipid droplet content (P < 0.001). In line with this, LX-2 cells stably overexpressing I148M showed augmented proliferation and migration, lower retinol, and abolished retinoid X receptor/retinoid A receptor transcriptional activities but more lipid droplets. Knockdown of I148M PNPLA3 (P < 0.001) also reduces chemokine (C-C motif) ligand 5 and collagen1α1 expression (P < 0.05). Notably, I148M cells display reduced peroxisome proliferator-activated receptor gamma transcriptional activity, and this effect was attributed to increased c-Jun N-terminal kinase, thereby inhibiting peroxisome proliferator-activated receptor gamma through serine 84 phosphorylation and promoting activator protein 1 transcription. Conversely, the c-Jun N-terminal kinase inhibitor SP600125 and the peroxisome proliferator-activated receptor gamma agonist rosiglitazone decreased activator protein

ω-3 PUFAs ameliorate liver fibrosis and inhibit hepatic stellate cells proliferation and activation by promoting YAP/TAZ degradation.

PubMed

Zhang, Kun; Chang, Yanan; Shi, Zhemin; Han, Xiaohui; Han, Yawei; Yao, Qingbin; Hu, Zhimei; Cui, Hongmei; Zheng, Lina; Han, Tao; Hong, Wei

2016-07-20

Elevated levels of the transcriptional regulators Yes-associated protein (YAP) and transcriptional coactivators with PDZ-binding motif (TAZ), key effectors of the Hippo pathway, have been shown to play essential roles in controlling liver cell fate and the activation of hepatic stellate cells (HSCs). The dietary intake of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) has been positively associated with a number of health benefits including prevention and reduction of cardiovascular diseases, inflammation and cancers. However, little is known about the impact of ω-3 PUFAs on liver fibrosis. In this study, we used CCl4-induced liver fibrosis mouse model and found that YAP/TAZ is over-expressed in the fibrotic liver and activated HSCs. Fish oil administration to the model mouse attenuates CCl4-induced liver fibrosis. Further study revealed that ω-3 PUFAs down-regulate the expression of pro-fibrogenic genes in activated HSCs and fibrotic liver, and the down-regulation is mediated via YAP, thus identifying YAP as a target of ω-3 PUFAs. Moreover, ω-3 PUFAs promote YAP/TAZ degradation in a proteasome-dependent manner. Our data have identified a mechanism of ω-3 PUFAs in ameliorating liver fibrosis.

Perfluorooctane Sulfonate-Induced Hepatic Steatosis in Male Sprague Dawley Rats Is Not Attenuated by Dietary Choline Supplementation.

PubMed

Bagley, Bradford D; Chang, Shu-Ching; Ehresman, David J; Eveland, Alan; Zitzow, Jeremiah D; Parker, George A; Peters, Jeffrey M; Wallace, Kendall B; Butenhoff, John L

2017-12-01

Perfluorooctane sulfonate (PFOS) is an environmentally persistent chemical. Dietary 100 ppm PFOS fed to male mice and rats for 4 weeks caused hepatic steatosis through an unknown mechanism. Choline deficient diets can cause hepatic steatosis. A hepatic choline:PFOS ion complex was hypothesized to cause this effect in mice. This study tested whether dietary choline supplementation attenuates PFOS-induced hepatic steatosis in rats. Sprague Dawley rats (12/sex/group) were fed control, choline supplemented (CS), 100 ppm PFOS, or 100 ppm PFOS + CS diets for 3 weeks. Male rats fed both PFOS-containing diets had decreased serum cholesterol and triglycerides (TGs) on days 9, 16, and/or 23 and increased hepatic free fatty acids and TG (ie, steatosis). Female rats fed both PFOS diets had decreased serum cholesterol on days 9 and 16 and decreased hepatic free fatty acid and TG at termination (ie, no steatosis). Liver PFOS concentrations were similar for both sexes. Liver choline concentrations were increased in male rats fed PFOS (±CS), but the increase was lower in the PFOS + CS group. Female liver choline concentrations were not altered by any diet. These findings demonstrate a clear sex-related difference in PFOS-induced hepatic steatosis in the rat. Additional evaluated mechanisms (ie, nuclear receptor activation, mRNA upregulation, and choline kinase activity inhibition) did not appear to be involved in the hepatic steatosis. Dietary PFOS (100 ppm) induced hepatic steatosis in male, but not female, rats that was not attenuated by choline supplementation. The mechanism of lipid accumulation and the sex-related differences warrant further investigation. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

CCN1/CYR61 overexpression in hepatic stellate cells induces ER stress-related apoptosis.

PubMed

Borkham-Kamphorst, Erawan; Steffen, Bettina T; Van de Leur, Eddy; Haas, Ute; Tihaa, Lidia; Friedman, Scott L; Weiskirchen, Ralf

2016-01-01

CCN1/CYR61 is a matricellular protein of the CCN family, comprising six secreted proteins specifically associated with the extracellular matrix (ECM). CCN1 acts as an enhancer of the cutaneous wound healing process by preventing hypertrophic scar formation through induction of myofibroblast senescence. In liver fibrosis, the senescent cells are primarily derived from activated hepatic stellate cells (HSC) that initially proliferate in response to liver damage and are the major source of ECM. We investigate here the possible use of CCN1 as a senescence inducer to attenuate liver fibrogenesis by means of adenoviral gene transfer in primary HSC, myofibroblasts (MFB) and immortalized HSC lines (i.e. LX-2, CFSC-2G). Infection with Ad5-CMV-CCN1 induced large amounts of CCN1 protein in all these cells, resulting in an overload of the endoplasmic reticulum (ER) and in a compensatory unfolded protein response (UPR). The UPR resulted in upregulation of ER chaperones including BIP/Grp78, Grp94 and led to an activation of IRE1α as evidenced by spliced XBP1 mRNA with IRE1α-induced JNK phosphorylation. The UPR arm PERK and eIF2a was phosphorylated, combined with significant CHOP upregulation. Ad5-CMV-CCN1 induced HSC apoptosis that was evident by proteolytic cleavage of caspase-12, caspase-9 and the executor caspase-3 and positive TUNEL stain. Remarkably, Ad5-CMV-CCN1 effectively reduced collagen type I mRNA expression and protein. We conclude that the matricellular protein CCN1 gene transfer induces HSC apoptosis through ER stress and UPR. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Pretreatment of parecoxib attenuates hepatic ischemia/reperfusion injury in rats.

PubMed

Zhang, Tao; Ma, Yi; Xu, Kang-Qing; Huang, Wen-Qi

2015-11-17

Previous studies showed that cyclooxygenase(COX) was involved in ischemia/reperfusion (I/R) injuries. Parecoxib, a selective inhibitor for COX -2, has been shown to have protective properties in reducing I/R injury in the heart, kidney and brain. The aim of this study was to investigate the effects of parecoxib on hepatic I/R and to explore the underlying mechanisms. Fifty-two Sprague-Dawley rats were randomly divided into three groups: the sham-operation (Sham) group, the hepatic ischemia/reperfusion (I/R) group, and the parecoxib pretreated I/R (I/R + Pare) group. Partial warm ischemia was produced in the left and middle hepatic lobes of Sprague-Dawley rats for 60 min, followed by 6 h of reperfusion. Rats in the I/R + Pare group received parecoxib (10 mg/kg) intraperitoneally twice a day for three consecutive days prior to ischemia. Blood and tissue samples from the groups were collected 6 h after reperfusion, and a survival study was performed. Pretreatment with parecoxib prior to I/R insult significantly reduced I/R-induced elevations of aminotransferases, and significantly improved the histological status of the liver. Parecoxib significantly suppressed inflammatory cascades, as demonstrated by attenuations in TNF-α and IL-6. Parecoxib significantly inhibited iNOS and nitrotyrosine expression after I/R and significantly attenuated I/R-induced apoptosis. The 7-day survival rate was increased by pre-administration of parecoxib. Administration of parecoxib prior to hepatic I/R attenuates hepatic injury through inhibition of inflammatory response and nitrosative stress.

NADPH Oxidase Signaling Pathway Mediates Mesenchymal Stem Cell-Induced Inhibition of Hepatic Stellate Cell Activation.

PubMed

Qiao, Haowen; Zhou, Yu; Qin, Xingping; Cheng, Jing; He, Yun; Jiang, Yugang

2018-01-01

Bone marrow-derived mesenchymal stem cells (BMSCs) have blossomed into an effective approach with great potential for the treatment of liver fibrosis. The aim of this study was to investigate the underlying antifibrosis mechanisms by which the BMSC inhibit activated hepatic stellate cells (HSCs) in vivo and in vitro. To study the effect of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) on activated HSCs, we used HSCs and the coculture systems to evaluate the inhibition of activated HSCs from the aspects of the apoptosis of activated HSCs. In addition, activation of NADPH oxidase pathway and the changes in liver histopathology were tested by using the carbon tetrachloride- (CCl 4 -) induced liver fibrosis in mice. Introduction of hBM-MSCs significantly inhibited the proliferation of activated HSCs by inducing the apoptosis process of activated HSCs. The effect of hBM-MSCs reduced the signaling pathway of NADPH oxidase in activated HSCs. Besides, the signaling pathway of NADPH oxidase mediated hBM-MSC upregulation of the expression of the peroxisome proliferator-activated receptor γ and downregulation of the expression of α 1(I) collagen and alpha-smooth muscle actin ( α -SMA) in activated HSCs. Moreover, the hBM-MSC-induced decrease in the signaling pathway of NADPH oxidase was accompanied by the decrease of the activated HSC number and liver fibrosis in a mouse model of CCl 4 -induced liver fibrosis. The hBM-MSCs act as a promising drug source against liver fibrosis development with respect to hepatopathy as a therapeutic target.

A bioinformatic and mechanistic study elicits the antifibrotic effect of ursolic acid through the attenuation of oxidative stress with the involvement of ERK, PI3K/Akt, and p38 MAPK signaling pathways in human hepatic stellate cells and rat liver

PubMed Central

He, Wenhua; Shi, Feng; Zhou, Zhi-Wei; Li, Bimin; Zhang, Kunhe; Zhang, Xinhua; Ouyang, Canhui; Zhou, Shu-Feng; Zhu, Xuan

2015-01-01

NADPH oxidases (NOXs) are a predominant mediator of redox homeostasis in hepatic stellate cells (HSCs), and oxidative stress plays an important role in the pathogenesis of liver fibrosis. Ursolic acid (UA) is a pentacyclic triterpenoid with various pharmacological activities, but the molecular targets and underlying mechanisms for its antifibrotic effect in the liver remain elusive. This study aimed to computationally predict the molecular interactome and mechanistically investigate the antifibrotic effect of UA on oxidative stress, with a focus on NOX4 activity and cross-linked signaling pathways in human HSCs and rat liver. Drug–drug interaction via chemical–protein interactome tool, a server that can predict drug–drug interaction via chemical–protein interactome, was used to predict the molecular targets of UA, and Database for Annotation, Visualization, and Integrated Discovery was employed to analyze the signaling pathways of the predicted targets of UA. The bioinformatic data showed that there were 611 molecular proteins possibly interacting with UA and that there were over 49 functional clusters responding to UA. The subsequential benchmarking data showed that UA significantly reduced the accumulation of type I collagen in HSCs in rat liver, increased the expression level of MMP-1, but decreased the expression level of TIMP-1 in HSC-T6 cells. UA also remarkably reduced the gene expression level of type I collagen in HSC-T6 cells. Furthermore, UA remarkably attenuated oxidative stress via negative regulation of NOX4 activity and expression in HSC-T6 cells. The employment of specific chemical inhibitors, SB203580, LY294002, PD98059, and AG490, demonstrated the involvement of ERK, PI3K/Akt, and p38 MAPK signaling pathways in the regulatory effect of UA on NOX4 activity and expression. Collectively, the antifibrotic effect of UA is partially due to the oxidative stress attenuating effect through manipulating NOX4 activity and expression. The results

Iron Enhances Hepatic Fibrogenesis and Activates Transforming Growth Factor-β Signaling in Murine Hepatic Stellate Cells.

PubMed

Mehta, Kosha J; Coombes, Jason D; Briones-Orta, Marco; Manka, Paul P; Williams, Roger; Patel, Vinood B; Syn, Wing-Kin

2018-02-01

Although excess iron induces oxidative stress in the liver, it is unclear whether it directly activates the hepatic stellate cells (HSC). We evaluated the effects of excess iron on fibrogenesis and transforming growth factor beta (TGF-β) signaling in murine HSC. Cells were treated with holotransferrin (0.005-5g/L) for 24 hours, with or without the iron chelator deferoxamine (10µM). Gene expressions (α-SMA, Col1-α1, Serpine-1, TGF-β, Hif1-α, Tfrc and Slc40a1) were analyzed by quantitative real time-polymerase chain reaction, whereas TfR1, ferroportin, ferritin, vimentin, collagen, TGF-β RII and phospho-Smad2 proteins were evaluated by immunofluorescence, Western blot and enzyme-linked immunosorbent assay. HSC expressed the iron-uptake protein transferrin receptor 1 (TfR1) and the iron-export protein ferroportin. Holotransferrin upregulated TfR1 expression by 1.8-fold (P < 0.03) and ferritin accumulation (iron storage) by 2-fold (P < 0.01), and activated HSC with 2-fold elevations (P < 0.03) in α-SMA messenger RNA and collagen secretion, and a 1.6-fold increase (P < 0.01) in vimentin protein. Moreover, holotransferrin activated the TGF-β pathway with TGF-β messenger RNA elevated 1.6-fold (P = 0.05), and protein levels of TGF-β RII and phospho-Smad2 increased by 1.8-fold (P < 0.01) and 1.6-fold (P < 0.01), respectively. In contrast, iron chelation decreased ferritin levels by 30% (P < 0.03), inhibited collagen secretion by 60% (P < 0.01), repressed fibrogenic genes α-SMA (0.2-fold; P < 0.05) and TGF-β (0.4-fold; P < 0.01) and reduced levels of TGF-β RII and phospho-Smad2 proteins. HSC express iron-transport proteins. Holotransferrin (iron) activates HSC fibrogenesis and the TGF-β pathway, whereas iron depletion by chelation reverses this, suggesting that this could be a useful adjunct therapy for patients with fibrosis. Further studies in primary human HSC and animal models are necessary to confirm this. Published by Elsevier Inc.

RNA Sequencing Reveals Novel Transcripts from Sympathetic Stellate Ganglia During Cardiac Sympathetic Hyperactivity.

PubMed

Bardsley, Emma N; Davis, Harvey; Ajijola, Olujimi A; Buckler, Keith J; Ardell, Jeffrey L; Shivkumar, Kalyanam; Paterson, David J

2018-06-05

Cardiovascular disease is the most prevalent age-related illness worldwide, causing approximately 15 million deaths every year. Hypertension is central in determining cardiovascular risk and is a strong predictive indicator of morbidity and mortality; however, there remains an unmet clinical need for disease-modifying and prophylactic interventions. Enhanced sympathetic activity is a well-established contributor to the pathophysiology of hypertension, however the cellular and molecular changes that increase sympathetic neurotransmission are not known. The aim of this study was to identify key changes in the transcriptome in normotensive and spontaneously hypertensive rats. We validated 15 of our top-scoring genes using qRT-PCR, and network and enrichment analyses suggest that glutamatergic signalling plays a key role in modulating Ca 2+ balance within these ganglia. Additionally, phosphodiesterase activity was found to be altered in stellates obtained from the hypertensive rat, suggesting that impaired cyclic nucleotide signalling may contribute to disturbed Ca 2+ homeostasis and sympathetic hyperactivity in hypertension. We have also confirmed the presence of these transcripts in human donor stellate samples, suggesting that key genes coupled to neurotransmission are conserved. The data described here may provide novel targets for future interventions aimed at treating sympathetic hyperactivity associated with cardiovascular disease and other dysautonomias.

Exercise training modulates the hepatic renin-angiotensin system in fructose-fed rats.

PubMed

Frantz, Eliete Dalla Corte; Medeiros, Renata Frauches; Giori, Isabele Gomes; Lima, Juliana Bittencourt Silveira; Bento-Bernardes, Thais; Gaique, Thaiane Gadioli; Fernandes-Santos, Caroline; Fernandes, Tiago; Oliveira, Edilamar Menezes; Vieira, Carla Paulo; Conte-Junior, Carlos Adam; Oliveira, Karen Jesus; Nobrega, Antonio Claudio Lucas

2017-09-01

What is the central question of this study? What are the effects of exercise training on the hepatic renin-angiotensin system and their contribution to damage resulting from fructose overload in rats? What is the main finding and its importance? Exercise training attenuated the deleterious actions of the angiotensin-converting enzyme/angiotensin II/angiotensin II type 1 receptor axis and increased expression of the counter-regulatory (angiotensin-converting enzyme 2/angiotensin (1-7)/Mas receptor) axis in the liver. Therefore, our study provides evidence that exercise training modulates the hepatic renin-angiotensin system, which contributes to reducing the progression of metabolic dysfunction and non-alcoholic fatty liver disease in fructose-fed rats. The renin-angiotensin system (RAS) has been implicated in the development of metabolic syndrome. We investigated whether the hepatic RAS is modulated by exercise training and whether this modulation improves the deleterious effects of fructose overload in rats. Male Wistar rats were divided into (n = 8 each) control (CT), exercise control (CT-Ex), high-fructose (HFr) and exercise high-fructose (HFr-Ex) groups. Fructose-drinking rats received d-fructose (100 g l -1 ). After 2 weeks, CT-Ex and HFr-Ex rats were assigned to a treadmill training protocol at moderate intensity for 8 weeks (60 min day -1 , 4 days per week). We assessed body mass, glucose and lipid metabolism, hepatic histopathology, angiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) activity, the angiotensin concentration and the expression profile of proteins affecting the hepatic RAS, gluconeogenesis and inflammation. Neither fructose overload nor exercise training influenced body mass gain and serum ACE and ACE2 activity. The HFr group showed hyperinsulinaemia, but exercise training normalized this parameter. Exercise training was effective in preventing hepatic steatosis and in preventing triacylglycerol and

Modulation of gut microbiota contributes to curcumin-mediated attenuation of hepatic steatosis in rats.

PubMed

Feng, Wenhuan; Wang, Hongdong; Zhang, Pengzi; Gao, Caixia; Tao, Junxian; Ge, Zhijuan; Zhu, Dalong; Bi, Yan

2017-07-01

Structural disruption of gut microbiota contributes to the development of non-alcoholic fatty liver disease (NAFLD) and modulating the gut microbiota represents a novel strategy for NAFLD prevention. Although previous studies have demonstrated that curcumin alleviates hepatic steatosis, its effect on the gut microbiota modulation has not been investigated. Next generation sequencing and multivariate analysis were utilized to evaluate the structural changes of gut microbiota in a NAFLD rat model induced by high fat-diet (HFD) feeding. We found that curcumin attenuated hepatic ectopic fat deposition, improved intestinal barrier integrity, and alleviated metabolic endotoxemia in HFD-fed rats. More importantly, curcumin dramatically shifted the overall structure of the HFD-disrupted gut microbiota toward that of lean rats fed a normal diet and altered the gut microbial composition. The abundances of 110 operational taxonomic units (OTUs) were altered by curcumin. Seventy-six altered OTUs were significantly correlated with one or more hepatic steatosis associated parameters and designated 'functionally relevant phylotypes'. Thirty-six of the 47 functionally relevant OTUs that were positively correlated with hepatic steatosis associated parameters were reduced by curcumin. These results indicate that curcumin alleviates hepatic steatosis in part through stain-specific impacts on hepatic steatosis associated phylotypes of gut microbiota in rats. Compounds with antimicrobial activities should be further investigated as novel adjunctive therapies for NAFLD. Copyright © 2017 Elsevier B.V. All rights reserved.

Ammonia produces pathological changes in human hepatic stellate cells and is a target for therapy of portal hypertension.

PubMed

Jalan, Rajiv; De Chiara, Francesco; Balasubramaniyan, Vairappan; Andreola, Fausto; Khetan, Varun; Malago, Massimo; Pinzani, Massimo; Mookerjee, Rajeshwar P; Rombouts, Krista

2016-04-01

Hepatic stellate cells (HSCs) are vital to hepatocellular function and the liver response to injury. They share a phenotypic homology with astrocytes that are central in the pathogenesis of hepatic encephalopathy, a condition in which hyperammonemia plays a pathogenic role. This study tested the hypothesis that ammonia modulates human HSC activation in vitro and in vivo, and evaluated whether ammonia lowering, by using l-ornithine phenylacetate (OP), modifies HSC activation in vivo and reduces portal pressure in a bile duct ligation (BDL) model. Primary human HSCs were isolated and cultured. Proliferation (BrdU), metabolic activity (MTS), morphology (transmission electron, light and immunofluorescence microscopy), HSC activation markers, ability to contract, changes in oxidative status (ROS) and endoplasmic reticulum (ER) were evaluated to identify effects of ammonia challenge (50 μM, 100 μM, 300 μM) over 24-72 h. Changes in plasma ammonia levels, markers of HSC activation, portal pressure and hepatic eNOS activity were quantified in hyperammonemic BDL animals, and after OP treatment. Pathophysiological ammonia concentrations caused significant and reversible changes in cell proliferation, metabolic activity and activation markers of hHSC in vitro. Ammonia also induced significant alterations in cellular morphology, characterised by cytoplasmic vacuolisation, ER enlargement, ROS production, hHSC contraction and changes in pro-inflammatory gene expression together with HSC-related activation markers such as α-SMA, myosin IIa, IIb, and PDGF-Rβ. Treatment with OP significantly reduced plasma ammonia (BDL 199.1 μmol/L±43.65 vs. BDL+OP 149.27 μmol/L±51.1, p<0.05) and portal pressure (BDL 14±0.6 vs. BDL+OP 11±0.3 mmHg, p<0.01), which was associated with increased eNOS activity and abrogation of HSC activation markers. The results show for the first time that ammonia produces deleterious morphological and functional effects on HSCs in vitro. Targeting ammonia

Opuntia ficus indica (nopal) attenuates hepatic steatosis and oxidative stress in obese Zucker (fa/fa) rats.

PubMed

Morán-Ramos, Sofía; Avila-Nava, Azalia; Tovar, Armando R; Pedraza-Chaverri, José; López-Romero, Patricia; Torres, Nimbe

2012-11-01

Nonalcoholic fatty liver disease (NAFLD) is associated with multiple factors such as obesity, insulin resistance, and oxidative stress. Nopal, a cactus plant widely consumed in the Mexican diet, is considered a functional food because of its antioxidant activity and ability to improve biomarkers of metabolic syndrome. The aim of this study was to assess the effect of nopal consumption on the development of hepatic steatosis and hepatic oxidative stress and on the regulation of genes involved in hepatic lipid metabolism. Obese Zucker (fa/fa) rats were fed a control diet or a diet containing 4% nopal for 7 wk. Rats fed the nopal-containing diet had ∼50% lower hepatic TG than the control group as well as a reduction in hepatomegaly and biomarkers of hepatocyte injury such as alanine and aspartate aminotransferases. Attenuation of hepatic steatosis by nopal consumption was accompanied by a higher serum concentration of adiponectin and a greater abundance of mRNA for genes involved in lipid oxidation and lipid export and production of carnitine palmitoyltransferase-1 and microsomal TG transfer proteins in liver. Hepatic reactive oxygen species and lipid peroxidation biomarkers were significantly lower in rats fed nopal compared with the control rats. Furthermore, rats fed the nopal diet had a lower postprandial serum insulin concentration and a greater liver phosphorylated protein kinase B (pAKT):AKT ratio in the postprandial state. This study suggests that nopal consumption attenuates hepatic steatosis by increasing fatty acid oxidation and VLDL synthesis, decreasing oxidative stress, and improving liver insulin signaling in obese Zucker (fa/fa) rats.

Protective effect of gastrodin on bile duct ligation-induced hepatic fibrosis in rats.

PubMed

Zhao, Shuangshuang; Li, Naren; Zhen, Yongzhan; Ge, Maoxu; Li, Yi; Yu, Bin; He, Hongwei; Shao, Rong-Guang

2015-12-01

Gastrodin has been showed to possess many beneficial physiological functions, including protection against inflammation and oxidation and apoptosis. Studies showed inflammation and oxidation play important roles in producing liver damage and initiating hepatic fibrogenesis. However, it has not been reported whether gastrodin has a protective effect against hepatic fibrosis or not. This is first ever made attempts to test gastrodin against liver fibrosis in bile duct ligation (BDL) rats. The aim of the present study is to evaluate the effect of gastrodin on BDL-induced hepatic fibrosis in rats. BDL rats were divided into two groups, BDL alone group, and BDL-gastrodin group treated with gastrodin (5 mg/ml in drinking water). The effects of gastrodin on BDL-induced hepatic injury and fibrosis in rats were estimated by assessing serum, urine, bile and liver tissue biochemistry followed by liver histopathology (using hematoxylin & eosin and sirius red stain) and hydroxyproline content measurement. The results showed that gastrodin treatment significantly reduced collagen content, bile duct proliferation and parenchymal necrosis after BDL. The serum alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST) decreased with gastrodin treatment by 15.1 and 23.6 percent respectively in comparison to BDL group did not receive gastrodin. Gastrodin also significantly increased the level of serum high density lipoprotein (HDL) by 62.5 percent and down-regulated the elevated urine total bilirubin (TBIL) by 56.5 percent, but had no effect on total bile acid (TBA) in serum, bile and liver tissues. The immunohistochemical assay showed gastrodin remarkably reduced the expressions of CD68 and NF-κB in BDL rats. Hepatic SOD levels, depressed by BDL, were also increased by gastrodin by 8.4 percent. In addition, the increases of hepatic MDA and NO levels in BDL rats were attenuated by gastrodin by 31.3 and 38.7 percent separately. Our results indicate that gastrodin

Expression patterns of STAT3, ERK and estrogen-receptor α are associated with development and histologic severity of hepatic steatosis: a retrospective study.

PubMed

Choi, Euno; Kim, Won; Joo, Sae Kyung; Park, Sunyoung; Park, Jeong Hwan; Kang, Yun Kyung; Jin, So-Young; Chang, Mee Soo

2018-04-03

Hepatic steatosis renders hepatocytes vulnerable to injury, resulting in the progression of preexisting liver disease. Previous animal and cell culture studies implicated mammalian target of rapamycin (mTOR), signal transducer and activator of transcription-3 (STAT3), extracellular signal-regulated kinase (ERK) and estrogen-receptor α in the pathogenesis of hepatic steatosis and disease progression. However, to date there have been few studies performed using human liver tissue to study hepatic steatosis. We examined the expression patterns of mTOR, STAT3, ERK and estrogen-receptor α in liver tissues from patients diagnosed with hepatic steatosis. We reviewed the clinical and histomorphological features of 29 patients diagnosed with hepatic steatosis: 18 with non-alcoholic fatty liver disease (NAFLD), 11 with alcoholic fatty acid disease (AFLD), and a control group (16 biliary cysts and 22 hepatolithiasis). Immunohistochemistry was performed on liver tissue using an automated immunostainer. The histologic severity of hepatic steatosis was evaluated by assessing four key histomorphologic parameters common to NAFLD and AFLD: steatosis, lobular inflammation, ballooning degeneration and fibrosis. mTOR, phosphorylated STAT3, phosphorylated pERK, estrogen-receptor α were found to be more frequently expressed in the hepatic steatosis group than in the control group. Specifically, mTOR was expressed in 78% of hepatocytes, and ERK in 100% of hepatic stellate cells, respectively, in patients with NAFLD. Interestingly, estrogen-receptor α was diffusely expressed in hepatocytes in all NALFD cases. Phosphorylated (active) STAT3 was expressed in 73% of hepatocytes and 45% of hepatic stellate cells in patients with AFLD, and phosphorylated (active) ERK was expressed in hepatic stellate cells in all AFLD cases. Estrogen-receptor α was expressed in all AFLD cases (focally in 64% of AFLD cases, and diffusely in 36%). Phosphorylated STAT3 expression in hepatocytes and hepatic

HEPATIC VITAMIN A IN THE RAT AS AFFECTED BY THE ADMINISTRATION OF DIBENZANTHRACENE

PubMed Central

Abels, Jules C.; Gorham, Alice T.; Eberlin, Shirley L.; Halter, Robert; Rhoads, C. P.

1942-01-01

1. The decreased concentrations of vitamin A in the livers of rats given dibenzanthracene probably are due to a particular effect of the carcinogen on the ability of the liver to store the vitamin and not to the production of general hepatic dysfunction. 2. The administration of dibenzanthracene to normal rats does not (a) increase significantly their hepatic content of total fat nor decrease that of phospholipid; (b) impair the ability of their livers to fabricate serum albumin; (c) impair the capacity of their livers to esterify cholesterol or phenol; (d) interfere with the hepatic synthesis and conjugation of glucuronic acid; or (e) interfere with the hepatic storage of riboflavin. 3. The simultaneous ingestion of yeast by the dibenzanthracene-treated rats further depletes their hepatic stores of vitamin A. This depletion conceivably is due to the fact that yeast alone also might deplete the liver of its vitamin A and thus a summation of two similar effects is attained. 4. The results suggest a competition between vitamin A and dibenzanthracene for some substance, possibly a protein, to which vitamin A may be bound in the liver. PMID:19871225

Long-term administration of Salvia miltiorrhiza ameliorates carbon tetrachloride-induced hepatic fibrosis in rats.

PubMed

Lee, Tzung-Yan; Wang, Guei-Jane; Chiu, Jen-Hwey; Lin, Han-Chieh

2003-11-01

Carbon tetrachloride (CCl4) is metabolized by cytochrome P450 to form a reactive trichloromethyl radical that triggers a chain of lipid peroxidation. These changes lead to cell injury, and chronic liver injury leads to excessive deposition of collagen in liver, resulting in liver fibrosis. The aim of this study was to evaluate the effects of long-term Salvia miltiorrhiza administration in CCl4-induced hepatic injury in rats. Salvia miltiorrhiza (10, 25 or 50 mg kg(-1) twice a day) was given for 9 weeks, beginning at the same time as the injections of CCl4. Rats receiving CCl4 alone showed a decreased hepatic glutathione level and an increased glutathione-S-transferase content. The hepatic thiobarbituratic acid-reactive substance levels were increased. CCl4 also caused a prominent collagen deposition in liver histology that was further supported by the increased hepatic mRNA expression of transforming growth factor-beta1, tissue inhibitor of metalloproteinase-1 and procollagen I. Salvia miltiorrhiza administration led to a dose-dependent increase in hepatic glutathione levels and a decrease in peroxidation products. Additionally, it reduced the mRNA expression of markers for hepatic fibrogenesis. In conclusion, long-term administration of Salvia miltiorrhiza in rats ameliorated the CCl4-induced hepatic injury that probably related to a reduced oxidant stress and degree of hepatic fibrosis.

Hypervitaminosis A-induced hepatic fibrosis in a cat.

PubMed

Guerra, Juliana M; Daniel, Alexandre G T; Aloia, Thiago P A; de Siqueira, Adriana; Fukushima, André R; Simões, Denise M N; Reche-Júior, Archivaldo; Cogliati, Bruno

2014-03-01

The excessive intake of vitamin A in the form of vitamin concentrate, supplement or vitamin-rich liver can result in hypervitaminosis A in man and animals. Although osteopathologies resulting from chronic vitamin A intoxication in cats are well characterized, no information is available concerning feline hypervitaminosis A-induced liver disease. We report the first case of hepatic stellate cell lipidosis and hepatic fibrosis in a domestic cat that had been fed a diet based on raw beef liver. Radiographic examination revealed exostoses and ankylosis between vertebrae C1 and T7, compatible with deforming cervical spondylosis. Necropsy showed a slightly enlarged and light yellow to bronze liver. Microscopic and ultrastructural analyses of liver tissues revealed diffuse and severe liver fibrosis associated with hepatic stellate cell hyperplasia and hypertrophy. These cells showed immunopositive staining for α-smooth muscle actin and desmin markers. The necropsy findings of chronic liver disease coupled with osteopathology supported the diagnosis of hypervitaminosis A. As in human hepatology, if there is dietary evidence to support increased intake of vitamin A, then hypervitaminosis A should be considered in the differential diagnosis of chronic liver disease in cats.

Preventive effect of Qianggan-Rongxian Decoction on rat liver fibrosis

PubMed Central

Li, Chun-Hui; Pan, Li-Hui; Yang, Zong-Wei; Li, Chun-Yu; Xu, Wen-Xie

2008-01-01

AIM: To study the preventive effects of Qianggan-Rongxian Decoction on liver fibrosis induced by dimethylnitrosamine (DMN) in rats. METHODS: Male Wistar rats were randomly divided into hepatic fibrosis model group, control group and 3 treatment groups (12 rats in each group). Except for the normal control group, all the rats received 1% DMN (10 μL/kg body weight, i.p), 3 times a week for 4 wk. The rats in the 3 treatment groups including a high-dose DMN group (10 mL/kg), a medium-dose DMN group (7 mL/kg), and a low-dose DMN group (4 mL/kg) were daily gavaged with Qianggan-Rongxian Decoction, and the rats in the model and normal control groups were given saline vehicle. Enzyme-linked immunosorbent assay (ELISA) was used to determine the changes in serum hyaluronic acid (HA), laminin (LN), and type IV collagen levels. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured using routine laboratory methods. Pathologic changes, particularly fibrosis, were examined by hematoxylin and eosin (HE) and Sirius red staining. Hepatic stellate cells (HSC) were examined by transmission electron microscopy. RESULTS: Compared with the model control group, the serum levels of HA, LN, type IV collagen, ALT and AST were decreased markedly in the other groups after treatment with Qianggan-Rongxian Decoction, especially in the medium-dose DMN group (P < 0.05). Moreover, the area-density percentage of collagen fibrosis was lower in the Qianggan-Rongxian Decoction treatment groups than in the model group, and a more significant drop was observed in the medium-dose DMN group (P < 0.05). CONCLUSION: Qianggan-Rongxian Decoction can inhibit hepatic fibrosis due to chronic liver injury, delay the development of cirrhosis, and notably ameliorate liver function. It may be used as a safe and effective thera-peutic drug for patients with fibrosis. PMID:18567088

Exosome Adherence and Internalization by Hepatic Stellate Cells Triggers Sphingosine 1-Phosphate-dependent Migration*

PubMed Central

Wang, Ruisi; Ding, Qian; Yaqoob, Usman; de Assuncao, Thiago M.; Verma, Vikas K.; Hirsova, Petra; Cao, Sheng; Mukhopadhyay, Debabrata; Huebert, Robert C.; Shah, Vijay H.

2015-01-01

Exosomes are cell-derived extracellular vesicles thought to promote intercellular communication by delivering specific content to target cells. The aim of this study was to determine whether endothelial cell (EC)-derived exosomes could regulate the phenotype of hepatic stellate cells (HSCs). Initial microarray studies showed that fibroblast growth factor 2 induced a 2.4-fold increase in mRNA levels of sphingosine kinase 1 (SK1). Exosomes derived from an SK1-overexpressing EC line increased HSC migration 3.2-fold. Migration was not conferred by the dominant negative SK1 exosome. Incubation of HSCs with exosomes was also associated with an 8.3-fold increase in phosphorylation of AKT and 2.5-fold increase in migration. Exosomes were found to express the matrix protein and integrin ligand fibronectin (FN) by Western blot analysis and transmission electron microscopy. Blockade of the FN-integrin interaction with a CD29 neutralizing antibody or the RGD peptide attenuated exosome-induced HSC AKT phosphorylation and migration. Inhibition of endocytosis with transfection of dynamin siRNA, the dominant negative dynamin GTPase construct Dyn2K44A, or the pharmacological inhibitor Dynasore significantly attenuated exosome-induced AKT phosphorylation. SK1 levels were increased in serum exosomes derived from mice with experimental liver fibrosis, and SK1 mRNA levels were up-regulated 2.5-fold in human liver cirrhosis patient samples. Finally, S1PR2 inhibition protected mice from CCl4-induced liver fibrosis. Therefore, EC-derived SK1-containing exosomes regulate HSC signaling and migration through FN-integrin-dependent exosome adherence and dynamin-dependent exosome internalization. These findings advance our understanding of EC/HSC cross-talk and identify exosomes as a potential target to attenuate pathobiology signals. PMID:26534962

Exosome Adherence and Internalization by Hepatic Stellate Cells Triggers Sphingosine 1-Phosphate-dependent Migration.

PubMed

Wang, Ruisi; Ding, Qian; Yaqoob, Usman; de Assuncao, Thiago M; Verma, Vikas K; Hirsova, Petra; Cao, Sheng; Mukhopadhyay, Debabrata; Huebert, Robert C; Shah, Vijay H

2015-12-25

Exosomes are cell-derived extracellular vesicles thought to promote intercellular communication by delivering specific content to target cells. The aim of this study was to determine whether endothelial cell (EC)-derived exosomes could regulate the phenotype of hepatic stellate cells (HSCs). Initial microarray studies showed that fibroblast growth factor 2 induced a 2.4-fold increase in mRNA levels of sphingosine kinase 1 (SK1). Exosomes derived from an SK1-overexpressing EC line increased HSC migration 3.2-fold. Migration was not conferred by the dominant negative SK1 exosome. Incubation of HSCs with exosomes was also associated with an 8.3-fold increase in phosphorylation of AKT and 2.5-fold increase in migration. Exosomes were found to express the matrix protein and integrin ligand fibronectin (FN) by Western blot analysis and transmission electron microscopy. Blockade of the FN-integrin interaction with a CD29 neutralizing antibody or the RGD peptide attenuated exosome-induced HSC AKT phosphorylation and migration. Inhibition of endocytosis with transfection of dynamin siRNA, the dominant negative dynamin GTPase construct Dyn2K44A, or the pharmacological inhibitor Dynasore significantly attenuated exosome-induced AKT phosphorylation. SK1 levels were increased in serum exosomes derived from mice with experimental liver fibrosis, and SK1 mRNA levels were up-regulated 2.5-fold in human liver cirrhosis patient samples. Finally, S1PR2 inhibition protected mice from CCl4-induced liver fibrosis. Therefore, EC-derived SK1-containing exosomes regulate HSC signaling and migration through FN-integrin-dependent exosome adherence and dynamin-dependent exosome internalization. These findings advance our understanding of EC/HSC cross-talk and identify exosomes as a potential target to attenuate pathobiology signals. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

[Inhibitory effects of silymarin on hepatic fibrosis induced by dimethylnitrosamine: experiment with rats].

PubMed

Zhao, Xin-yan; Wang, Bao-en; Wang, Tai-ling; Li, Xin-min

2006-09-26

To investigate the antifibrotic effects of silymarin on hepatic fibrosis. Sixty-one male Wistar rats were randomly divided into three groups: control group (15 rats); DMN model group (23 rats), injected intraperitoneally with dimethylnitrosamine (DMN) 10 mg/kg twice per week for 8 weeks to induce hepatic fibrosis; and silymarin group (23 rats), injected intraperitoneally with DMN and given silymarin 50 mg/kg by gastric gavage daily for 8 weeks. Eight weeks late all rats were sacrificed. Blood samples were collected to measure the alanine transaminase (ALT), aspirate aminotransferase (AST), albumin, and total bilirubin (TBIL). The hydroxyproline (Hyp) content in the liver tissue was measured. The histopathological changes as well as the fibrosis stages and score were examined by microscopy. The levels of ALT, AST, and TBIL of the silymarin groups were 59 U/L +/- 19 U/L, 159 U/L +/- 39 U/L, and mean rank 24 respectively, all significantly lower than those of the DMN model group (128 U/L +/- 25 U/L, 246 U/L +/- 61 U/L, and mean rank 37 respectively, P < 0.01, P = 0.001, and P = 0.003). Compared with DMN rats, the level of Hyp of the silymarin was lower by 42.6%, the hepatic score of the silymarin was 6.2 +/- 2.4, significantly than that of the DMN model group (12.8 +/- 4.4, P = 0.001), and more cases in the silymarin group were at the lower stages. Silymarin markedly inhibits and reverse the progression of hepatic fibrosis induced by dimethylnitrosamine.

Diethylcarbamazine attenuates the expression of pro-fibrogenic markers and hepatic stellate cells activation in carbon tetrachloride-induced liver fibrosis.

PubMed

França, Maria Eduarda Rocha de; Rocha, Sura Wanessa Santos; Oliveira, Wilma Helena; Santos, Laise Aline; de Oliveira, Anne Gabrielle Vasconcelos; Barbosa, Karla Patrícia Sousa; Nunes, Ana Karolina Santana; Rodrigues, Gabriel Barros; Lós, Deniele Bezerra; Peixoto, Christina Alves

2018-04-01

While diethylcarbamazine citrate (DEC) displays important anti-inflammatory effects in experimental models of liver injury, the mechanisms of its action remain poorly understood. The aim of the present study was to investigate the fibrolytic potential of DEC. Mice receive two injections of carbon tetrachloride (CCl 4 ) per week for 8 weeks. DEC 50 mg/kg body weight was administered through drinking water during the last 12 days of liver injury. The expression of hepatic stellate cells (HSCs) activation markers, including smooth muscle α-actin (α-SMA), collagen I, transforming growth factor-β 1 (TGF-β1), matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1) was assessed. The influence of DEC on the intracellular MAPK pathways of the HSCs (JNK and p38 MAPK) was also estimated. DEC inhibited HSCs activation measured as the production of α-SMA and collagen I. In addition, it down regulated the production of TGF-β1 and TIMP-1, and concomitantly increased MMP-2 activity. Furthermore, DEC significantly inhibited the activation of the JNK and p38 MAPK signaling pathways. In conclusion, DEC significantly attenuated the severity of CCl 4 -induced liver injury and the progression of liver fibrosis, exerting a potential fibrolytic effect in the CCl 4 -induced fibrosis model.

High Sucrose Intake Ameliorates the Accumulation of Hepatic Triacylglycerol Promoted by Restraint Stress in Young Rats.

PubMed

Corona-Pérez, Adriana; Díaz-Muñoz, Mauricio; Rodríguez, Ida Soto; Cuevas, Estela; Martínez-Gómez, Margarita; Castelán, Francisco; Rodríguez-Antolín, Jorge; Nicolás-Toledo, Leticia

2015-11-01

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder. Stress promotes the onset of the NAFLD with a concomitant increment in the activity of the hepatic 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1). However, the interaction between the stress and a carbohydrate-enriched diet for the development of NAFLD in young animals is unknown. In the present study, we evaluated the impact of chronic stress on the hepatic triacylglycerol level of young rats fed or not with a high sucrose-diet. For doing this, 21-day old male Wistar rats were allocated into 4 groups: control (C), chronic restraint stress (St), high-sucrose diet (S30), and chronic restraint stress plus a 30 % sucrose diet (St + S30). Chronic restraint stress consisted of 1-hour daily session, 5 days per week and for 4 weeks. Rats were fed with a standard chow and tap water (C group) or 30 % sucrose diluted in water (S30 group). The St + S30 groups consumed less solid food but had an elevated visceral fat accumulation in comparison with the St group. The St group showed a high level of serum corticosterone and a high activity of the hepatic 11β-HSD-1 concomitantly to the augmentation of hepatic steatosis signs, a high hepatic triacylglycerol content, and hepatic oxidative stress. Conversely, the high-sucrose intake in stressed rats (St + S30 group) reduced the hepatic 11β-HSD-1 activity, the level of serum corticosterone, and the hepatic triacylglycerol content. Present findings show that a high-sucrose diet ameliorates the triacylglycerol accumulation in liver promoted by the restraint stress in young male rats.

Dietary medium-chain triglycerides attenuate hepatic lipid deposition in growing rats with protein malnutrition.

PubMed

Kuwahata, Masashi; Kubota, Hiroyo; Amano, Saki; Yokoyama, Meiko; Shimamura, Yasuhiro; Ito, Shunsuke; Ogawa, Aki; Kobayashi, Yukiko; Miyamoto, Ken-ichi; Kido, Yasuhiro

2011-01-01

The objective of this study was to investigate the effects of dietary medium-chain triglycerides (MCT) on hepatic lipid accumulation in growing rats with protein malnutrition. Weaning rats were fed either a low-protein diet (3%, LP) or control protein diet (20%, CP), in combination with or without MCT. The four groups were as follows: CP-MCT, CP+MCT, LP-MCT, and LP+MCT. Rats in the CP-MCT, CP+MCT and LP+MCT groups were pair-fed their respective diets based on the amount of diet consumed by the LP-MCT group. Rats were fed each experimental diet for 30 d. Four weeks later, the respiratory quotient was higher in the LP-MCT group than those in the other groups during the fasting period. Hepatic triglyceride content increased in the LP groups compared with the CP groups. Hepatic triglyceride content in the LP+MCT group, however, was significantly decreased compared with that in the LP-MCT group. Levels of carnitine palmitoyltransferase (CPT) 1a mRNA and CPT2 mRNA were significantly decreased in the livers of the LP-MCT group, as compared with corresponding mRNA levels of the other groups. These results suggest that ingestion of a low-protein diet caused fatty liver in growing rats. However, when rats were fed the low-protein diet with MCT, hepatic triglyceride deposition was attenuated, and mRNA levels encoding CPT1a and CPT2 were preserved at the levels of rats fed control protein diets.

In vivo hepatic differentiation potential of human umbilical cord-derived mesenchymal stem cells: Therapeutic effect on liver fibrosis/cirrhosis.

PubMed

Zhang, Guo-Zun; Sun, Hui-Cong; Zheng, Li-Bo; Guo, Jin-Bo; Zhang, Xiao-Lan

2017-12-14

To investigate the hepatic differentiation potential of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) and to evaluate their therapeutic effect on liver fibrosis/cirrhosis. A CCl 4 -induced liver fibrotic/cirrhotic rat model was used to assess the effect of hUC-MSCs. Histopathology was assessed by hematoxylin and eosin (H&E), Masson trichrome and Sirius red staining. The liver biochemical profile was measured using a Beckman Coulter analyzer. Expression analysis was performed using immunofluorescent staining, immunohistochemistry, Western blot, and real-time PCR. We demonstrated that the infused hUC-MSCs could differentiate into hepatocytes in vivo . Functionally, the transplantation of hUC-MSCs to CCl 4 -treated rats improved liver transaminases and synthetic function, reduced liver histopathology and reversed hepatobiliary fibrosis. The reversal of hepatobiliary fibrosis was likely due to the reduced activation state of hepatic stellate cells, decreased collagen deposition, and enhanced extracellular matrix remodeling via the up-regulation of MMP-13 and down-regulation of TIMP-1. Transplanted hUC-MSCs could differentiate into functional hepatocytes that improved both the biochemical and histopathologic changes in a CCl 4 -induced rat liver fibrosis model. hUC-MSCs may offer therapeutic opportunities for treating hepatobiliary diseases, including cirrhosis.

In vivo hepatic differentiation potential of human umbilical cord-derived mesenchymal stem cells: Therapeutic effect on liver fibrosis/cirrhosis

PubMed Central

Zhang, Guo-Zun; Sun, Hui-Cong; Zheng, Li-Bo; Guo, Jin-Bo; Zhang, Xiao-Lan

2017-01-01

AIM To investigate the hepatic differentiation potential of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) and to evaluate their therapeutic effect on liver fibrosis/cirrhosis. METHODS A CCl4-induced liver fibrotic/cirrhotic rat model was used to assess the effect of hUC-MSCs. Histopathology was assessed by hematoxylin and eosin (H&E), Masson trichrome and Sirius red staining. The liver biochemical profile was measured using a Beckman Coulter analyzer. Expression analysis was performed using immunofluorescent staining, immunohistochemistry, Western blot, and real-time PCR. RESULTS We demonstrated that the infused hUC-MSCs could differentiate into hepatocytes in vivo. Functionally, the transplantation of hUC-MSCs to CCl4-treated rats improved liver transaminases and synthetic function, reduced liver histopathology and reversed hepatobiliary fibrosis. The reversal of hepatobiliary fibrosis was likely due to the reduced activation state of hepatic stellate cells, decreased collagen deposition, and enhanced extracellular matrix remodeling via the up-regulation of MMP-13 and down-regulation of TIMP-1. CONCLUSION Transplanted hUC-MSCs could differentiate into functional hepatocytes that improved both the biochemical and histopathologic changes in a CCl4-induced rat liver fibrosis model. hUC-MSCs may offer therapeutic opportunities for treating hepatobiliary diseases, including cirrhosis. PMID:29290652

Orphan nuclear receptor NR4A2 inhibits hepatic stellate cell proliferation through MAPK pathway in liver fibrosis.

PubMed

Chen, Pengguo; Li, Jie; Huo, Yan; Lu, Jin; Wan, Lili; Li, Bin; Gan, Run; Guo, Cheng

2015-01-01

Hepatic stellate cells (HSCs) play a crucial role in liver fibrosis, which is a pathological process characterized by extracellular matrix accumulation. NR4A2 is a nuclear receptor belonging to the NR4A subfamily and vital in regulating cell growth, metabolism, inflammation and other biological functions. However, its role in HSCs is unclear. We analyzed NR4A2 expression in fibrotic liver and stimulated HSCs compared with control group and studied the influence on cell proliferation, cell cycle, cell apoptosis and MAPK pathway after NR4A2 knockdown. NR4A2 expression was examined by real-time polymerase chain reaction, Western blotting, immunohistochemistry and immunofluorescence analyses. NR4A2 expression was significantly lower in fibrotic liver tissues and PDGF BB or TGF-β stimulated HSCs compared with control group. After NR4A2 knockdown α-smooth muscle actin and Col1 expression increased. In addition, NR4A2 silencing led to the promotion of cell proliferation, increase of cell percentage in S phase and reduced phosphorylation of ERK1/2, P38 and JNK in HSCs. These results indicate that NR4A2 can inhibit HSC proliferation through MAPK pathway and decrease extracellular matrix in liver fibrogenesis. NR4A2 may be a promising therapeutic target for liver fibrosis.

Interleukin-22 induces hepatic stellate cell senescence and restricts liver fibrosis in mice.

PubMed

Kong, Xiaoni; Feng, Dechun; Wang, Hua; Hong, Feng; Bertola, Adeline; Wang, Fu-Sheng; Gao, Bin

2012-09-01

Interleukin (IL)-22 is known to play a key role in promoting antimicrobial immunity, inflammation, and tissue repair at barrier surfaces by binding to the receptors, IL-10R2 and IL-22R1. IL-22R1 is generally thought to be expressed exclusively in epithelial cells. In this study, we identified high levels of IL-10R2 and IL-22R1 expression on hepatic stellate cells (HSCs), the predominant cell type involved in liver fibrogenesis in response to liver damage. In vitro treatment with IL-22 induced the activation of signal transducer and activator of transcription (STAT) 3 in primary mouse and human HSCs. IL-22 administration prevented HSC apoptosis in vitro and in vivo, but surprisingly, the overexpression of IL-22 by either gene targeting (e.g., IL-22 transgenic mice) or exogenous administration of adenovirus expressing IL-22 reduced liver fibrosis and accelerated the resolution of liver fibrosis during recovery. Furthermore, IL-22 overexpression or treatment increased the number of senescence-associated beta-galactosidase-positive HSCs and decreased alpha-smooth muscle actin expression in fibrotic livers in vivo and cultured HSCs in vitro. Deletion of STAT3 prevented IL-22-induced HSC senescence in vitro, whereas the overexpression of a constitutively activated form of STAT3 promoted HSC senescence through p53- and p21-dependent pathways. Finally, IL-22 treatment up-regulated the suppressor of cytokine signaling (SOCS) 3 expression in HSCs. Immunoprecipitation analyses revealed that SOCS3 bound p53 and subsequently increased the expression of p53 and its target genes, contributing to IL-22-mediated HSC senescence. IL-22 induces the senescence of HSCs, which express both IL-10R2 and IL-22R1, thereby ameliorating liver fibrogenesis. The antifibrotic effect of IL-22 is likely mediated by the induction of HSC senescence, in addition to the previously discovered hepatoprotective functions of IL-22. Copyright © 2012 American Association for the Study of Liver Diseases.

Effects of treatment with Maraviroc a CCR5 inhibitor on a human hepatic stellate cell line.

PubMed

Coppola, Nicola; Perna, Angelica; Lucariello, Angela; Martini, Salvatore; Macera, Margherita; Carleo, Maria A; Guerra, Germano; Esposito, Vincenzo; De Luca, Antonio

2018-08-01

After an acute liver damage, tissue regeneration repairs lesions with degradation of deposed fibrotic material, while mechanisms of tissue restoration are persistently activated following several repeated injuries, inducing deposition of extracellular matrix. (ECM). Factors responsible for ECM remodeling have been identified in a pathway involving a family of zinc-dependent enzyme matrix metalloproteinases (MMPs), together with tissue inhibitor of metalloproteinases (TIMPs). Recent experimental models suggested a role of CCR5 receptor in the genesis of liver fibrosis. Drawing from these background we decided to evaluate the effects of the treatment with the CCR5 inhibitor Maraviroc on LX-2, a human hepatic stellate cell line (HSC). Treatment with Maraviroc resulted in a block in S phase of LX-2 cells with increased expression levels of cyclin D1 and p21 while the expression of p53 was reduced. Treatment with Maraviroc was also able to block the accumulation of fibrillar collagens and extracellular matrix proteins (ECM), as demonstrated by the decrease of specific markers as Collagen type I, α-SMA, and TGF-β1. In addition we observed a down regulation of both metalloproteins (MMP-2, MMP-9), used for the degradation of the extracellular matrix and their inhibitors (TIMP-1, TIMP-2). The identification of a compound that may modulate the dynamic of liver fibrosis could be crucial in all chronic liver diseases. Maraviroc could play an important role because, in addition to its own anti-HIV activity, it could reduce the release of pro-inflammatory citokynes implicated in liver fibrogenesis. © 2018 Wiley Periodicals, Inc.

Promotion of hepatic metastases by liver resection in the rat.

PubMed Central

Mizutani, J.; Hiraoka, T.; Yamashita, R.; Miyauchi, Y.

1992-01-01

In the early period following radical hepatectomy for hepatoma, recurrences in the remaining liver are frequently found. In regenerating liver, implantation and growth of tumour cells released into the portal system during surgical treatment might be promoted. We examined the relationship between liver regeneration and the formation of metastases following hepatic resection. Intraportal injections of rat ascites containing hepatoma AH130 cells at a concentration of 1 x 10(5) cells 0.2 ml-1 were made at various periods following two thirds liver resection in rats. Tumour cell injections immediately at 24 h after surgery resulted in an increased number of hepatic metastases compared with control animals. Tumour cell injections 2 weeks after hepatectomy, however, had no significant difference in effect compared with control rats. In contrast, tumour cells injected immediately after removal of half of the caudate lobe resulted in the same number of metastases as control animals. These results demonstrate that the number of artificially induced hepatic metastases was increased during an initial period of active liver regeneration and was proportional to the volume of hepatectomy. The effect of 5-fluorouracil (5FU) or mitomycin C (MMC) as inhibitors of hepatic regeneration on liver metastasis after hepatectomy was studied. The administration of 5FU (20 mg kg-1) or MMC (0.2 mg kg-1) immediately, 24 and 48 h after hepatectomy resulted in a marked reduction in metastatic lesions. The administration of 5FU caused delays in weight gain and decreases in the wet weight of remaining liver, while MMC had no effect on either. Accordingly, results of 5FU administration may be due to inhibitory effects on liver regeneration whilst that of MMC administration may be due to cytocidal antitumour effect. The effect of OK-432 as an immunoactivator on the implantation and growth of tumour cells in regenerating liver was also studied. Pretreatment with OK-432, 0.5 mg intraperitoneally on 7

Increased hepatic nicotine elimination after phenobarbital induction in the conscious rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foth, H.; Walther, U.I.; Kahl, G.F.

1990-09-15

Elimination parameters of (14C)nicotine in conscious rats receiving nicotine (0.3 mg/kg) either intravenously or orally were studied. The oral availability of unchanged nicotine, derived by comparison of the respective areas under the concentration vs time curves (AUC), was 89%, indicating low hepatic extraction ratios of about 10%. Pretreatment of rats with phenobarbital (PB) markedly increased hepatic first-pass extraction of nicotine. The oral availability of unchanged nicotine in plasma dropped to 1.4% of the corresponding values obtained from PB-treated rats receiving nicotine iv. After PB pretreatment, the clearance of iv nicotine was increased approximately twofold over controls, much less than themore » observed more than ninefold increase of hepatic first-pass extraction. It is assumed that extrahepatic metabolism contributed significantly to the rapid removal of nicotine from the plasma. The elimination of cotinine, originating from nicotine administered either po or iv, was significantly increased by PB pretreatment, as determined by the ratio of corresponding AUCs. The pattern of nicotine metabolites in urine also indicated an increase in the rate of cotinine metabolic turnover. The amount of norcotinine in the organic extract of urine paralleled PB microsomal enzyme induction. The ratio between urinary concentrations of the normetabolite and cotinine correlated strongly with the PB-induced state of rat liver. This may be a suitable indicator of PB-inducible hepatic cytochrome P450 isoenzyme(s). Since smoking habits in man are feedback-regulated by nicotine plasma concentrations, a similar increase of nicotine elimination by microsomal enzyme induction in man may be of relevance for tobacco consumption.« less

Different doses of partial liver irradiation promotes hepatic regeneration in rat

PubMed Central

Liu, Ying; Shi, Changzheng; Cui, Meng; Yang, Zhenhua; Gan, Danhui; Wang, Yiming

2015-01-01

The aim of this study is to investigate whether partial liver irradiation promotes hepatic regeneration in rat. Left-half liver of rat was irradiated to 10 Gy, and the Right-half to 0, 5, 10 and 15 Gy, respectively. Then, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) levels were evaluated on 0 day, 15-day, 30-day, 45-day and 60-day after liver irradiation. Next, the serum HGF, NF-κB and TGF-β1 levels were also analyzed on 60-day after liver irradiation. Lastly, the cyclinD1 protein expression was appraised by western blots on 60-day after liver irradiation. ALT, AST and ALP levels were reduced compared with that of controls. The serum HGF, NF-κB and TGF-β1 levels, and the cyclinD1 protein expression in liver irradiation group were increased compared with that of controls group. However, hepatic regeneration of higher dose-irradiated cirrhotic liver was triggered a more enhanced regeneration, compared with that of higher doses group. In summary, these results suggest that different doses of partial liver irradiation promotes hepatic regeneration in rat. PMID:26261535

Chlorogenic acid from honeysuckle improves hepatic lipid dysregulation and modulates hepatic fatty acid composition in rats with chronic endotoxin infusion.

PubMed

Zhou, Yan; Ruan, Zheng; Wen, Yanmei; Yang, Yuhui; Mi, Shumei; Zhou, Lili; Wu, Xin; Ding, Sheng; Deng, Zeyuan; Wu, Guoyao; Yin, Yulong

2016-03-01

Chlorogenic acid as a natural hydroxycinnamic acid has protective effect for liver. Endotoxin induced metabolic disorder, such as lipid dysregulation and hyperlipidemia. In this study, we investigated the effect of chlorogenic acid in rats with chronic endotoxin infusion. The Sprague-Dawley rats with lipid metabolic disorder (LD group) were intraperitoneally injected endotoxin. And the rats of chlorogenic acid-LD group were daily received chlorogenic acid by intragastric administration. In chlorogenic acid-LD group, the area of visceral adipocyte was decreased and liver injury was ameliorated, as compared to LD group. In chlorogenic acid-LD group, serum triglycerides, free fatty acids, hepatic triglycerides and cholesterol were decreased, the proportion of C20:1, C24:1 and C18:3n-6, Δ9-18 and Δ6-desaturase activity index in the liver were decreased, and the proportion of C18:3n-3 acid was increased, compared to the LD group. Moreover, levels of phosphorylated AMP-activated protein kinase, carnitine palmitoyltransferase-I, and fatty acid β-oxidation were increased in chlorogenic acid-LD group compared to LD rats, whereas levels of fatty acid synthase and acetyl-CoA carboxylase were decreased. These findings demonstrate that chlorogenic acid effectively improves hepatic lipid dysregulation in rats by regulating fatty acid metabolism enzymes, stimulating AMP-activated protein kinase activation, and modulating levels of hepatic fatty acids.

The effects of blueberry anthocyanins on histone acetylation in rat liver fibrosis

PubMed Central

Zhan, Wei; Liao, Xin; Xie, Ru-Jia; Tian, Tian; Yu, Lei; Liu, Xing; Liu, Jing; Li, Po; Han, Bing; Yang, Ting; Zhang, Bei; Cai, Li-Jun; Li, Rui; Yang, Qin

2017-01-01

To determine the effects ofanthocyanins from blueberries on hepatic stellate cell (HSCs-T6) and on histone acetylation during liver fibrosis induced by CCl4 in rats. Fifty male SD rats weighing 180 ± 20g were randomly placed into a control group, a hepatic fibrosis group, a blueberry treatment group, a blueberry intervention group, and a natural recovery group. After the rats were sacrificed, the livers and the liver indexes were measured, and the pathological changes were observed by HE staining and Masson staining. The blood was analyzed for the four indexes of liver fibrosis and liver function; nucleoprotein from liver tissues and karyoplasm were isolated to determine the expression of acH3K9, acH3K14, and acH3K18 by Western blotting. Compared with the lethal rate of the control group, the median lethal rate of HSCs-T6 cells treated with a the 50μmol/L concentration was 66.94% (P < 0.05). The protein expression on α-SMA, type I collagen, TIMP1 significantly decreased (P < 0.05) following treatment with 50 ug/ml of anthocyanin for 36 h; moreover, the expression of acH3K9, acH3K14 and acH3K18 modification were up-regulated (P < 0.05). Furthermore, compared with the liver in the model group, the liver in the intervention group showed the most obvious improvement (P < 0.01), and its karyoplasm had increased expression of acH3K9, acH3K14 and acH3K18 (P<0.01). Regulating histone acetylation could improve liver function and liver fibrosis indexes in rats with hepatic fibrosis. The mechanism might be related to certain genes that promote apoptosis, so as to inhibit the effect of anti hepatic fibrosis. PMID:29228569

Ginseng essence, a medicinal and edible herbal formulation, ameliorates carbon tetrachloride-induced oxidative stress and liver injury in rats.

PubMed

Lu, Kuan-Hung; Weng, Ching-Yi; Chen, Wei-Cheng; Sheen, Lee-Yan

2017-07-01

Ginseng essence (GE) is a formulation comprising four medicinal and edible herbs including ginseng ( Panax ginseng ), American ginseng ( Panax quinquefolius ), lotus seed ( Nelumbo nucifera ), and lily bulb ( Lilium longiflorum ). This study was aimed at investigating the hepatoprotective effect of GE against carbon tetrachloride (CCl 4 )-induced liver injury in rats. We treated Wistar rats daily with low, medium, and high [0.625 g/kg body weight (bw), 1.25 g/kg bw, and 3.125 g/kg bw, respectively] doses of GE for 9 wk. After the 1 st wk of treatment, rats were administered 20% CCl 4 (1.5 mL/kg bw) two times a week to induce liver damage until the treatment ended. Serum biochemical analysis indicated that GE ameliorated the elevation of aspartate aminotransferase and alanine aminotransferase and albumin decline in CCl 4 -treated rats. Moreover, CCl 4 -induced accumulation of hepatic total cholesterol and triglyceride was inhibited. The hepatoprotective effects of GE involved enhancing the hepatic antioxidant defense system including glutathione, glutathione peroxidase, glutathione reductase, glutathione S -transferase, superoxide dismutase, and catalase. In addition, histological analysis using hematoxylin and eosin and Masson's trichrome staining showed that GE inhibited CCl 4 -induced hepatic inflammation and fibrosis. Furthermore, immunohistochemical staining of alpha-smooth muscle actin indicated that CCl 4 -triggered activation of hepatic stellate cells was reduced. These findings demonstrate that GE improves CCl 4 -induced liver inflammation and fibrosis by attenuating oxidative stress. Therefore, GE could be a promising hepatoprotective herbal formulation for future development of phytotherapy.

Vitamin E supplementation does not prevent ethanol-reduced hepatic retinoic acid levels in rats

PubMed Central

Chung, Jayong; Veeramachaneni, Sudipta; Liu, Chun; Mernitz, Heather; Russell, Robert M.; Wang, Xiang-Dong

2009-01-01

Chronic, excessive ethanol intake can increase retinoic acid (RA) catabolism by inducing cytochrome P450 2E1 (CYP2E1). Vitamin E (VE) is an antioxidant implicated in CYP2E1 inhibition. In the current study, we hypothesized that VE supplementation inhibits CYP2E1 and decreases RA catabolism, thereby preventing ethanol-induced hepatocyte hyperproliferation. For 1 month, four groups of Sprague-Dawley rats were fed a Lieber-DeCarli liquid ethanol (36% of the total calories) diet as follows: either ethanol alone (Alc group) or ethanol in combination with 0.1 mg/kg body wt of all-trans RA (Alc+RA group), 2 mg/kg body wt of VE (Alc+VE group), or both together (Alc+RA+VE group). Control rats were pair-fed a liquid diet with an isocaloric amount of maltodextrin instead of ethanol. The ethanol-fed groups had three-fold higher hepatic CYP2E1 levels, 50% lower hepatic RA levels, and significantly increased hepatocyte proliferation when compared with the controls. The ethanol-fed rats given VE had more than four-fold higher hepatic VE concentrations than did ethanol-fed rats without VE, but this did not prevent ethanol induction of CYP2E1, lower hepatic retinoid levels, or hepatocellular hyperproliferation. Further, VE supplementation could not prevent RA catabolism in liver microsomal fractions of the ethanol-fed rats in vitro. These results show that VE supplementation can neither inhibit ethanol-induced changes in RA catabolism nor prevent ethanol-induced hepatocyte hyperproliferation in the rat liver. PMID:19854382

CD248/endosialin critically regulates hepatic stellate cell proliferation during chronic liver injury via a PDGF-regulated mechanism.

PubMed

Wilhelm, Annika; Aldridge, Victoria; Haldar, Debashis; Naylor, Amy J; Weston, Christopher J; Hedegaard, Ditte; Garg, Abhilok; Fear, Janine; Reynolds, Gary M; Croft, Adam P; Henderson, Neil C; Buckley, Christopher D; Newsome, Philip N

2016-07-01

CD248 (endosialin) is a stromal cell marker expressed on fibroblasts and pericytes. During liver injury, myofibroblasts are the main source of fibrotic matrix. To determine the role of CD248 in the development of liver fibrosis in the rodent and human setting. CD248 expression was studied by immunostaining and quantitative PCR in both normal and diseased human and murine liver tissue and isolated hepatic stellate cells (HSCs). Hepatic fibrosis was induced in CD248(-/-) and wild-type controls with carbon tetrachloride (CCl4) treatment. Expression of CD248 was seen in normal liver of humans and mice but was significantly increased in liver injury using both immunostaining and gene expression assays. CD248 was co-expressed with a range of fibroblast/HSC markers including desmin, vimentin and α-smooth muscle actin (α-SMA) in murine and human liver sections. CD248 expression was restricted to isolated primary murine and human HSC. Collagen deposition and α-SMA expression, but not inflammation and neoangiogenesis, was reduced in CD248(-/-) mice compared with wild-type mice after CCl4 treatment. Isolated HSC from wild-type and CD248(-/-) mice expressed platelet-derived growth factor receptor α (PDGFR-α) and PDGFR-β at similar levels. As expected, PDGF-BB stimulation induced proliferation of wild-type HSC, whereas CD248(-/-) HSC did not demonstrate a proliferative response to PDGF-BB. Abrogated PDGF signalling in CD248(-/-) HSC was confirmed by significantly reduced c-fos expression in CD248(-/-) HSC compared with wild-type HSC. Our data show that deletion of CD248 reduces susceptibility to liver fibrosis via an effect on PDGF signalling, making it an attractive clinical target for the treatment of liver injury. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Body distribution of nanoparticle-containing adriamycin injected into the hepatic artery of hepatoma-bearing rats.

PubMed

Chen, Jiang-Hao; Wang, Ling; Ling, Rui; Li, Yu; Wang, Zhe; Yao, Qing; Ma, Zhong

2004-08-01

The aim of the study was to investigate the body distribution of nanoparticle-containing adriamycin (NADR) injected into the hepatic artery of hepatoma-bearing rats. Thirty Walker-256 hepatoma-bearing rats were divided into two groups at random, with 15 rats in each. NADR and free adriamycin (FADR) were injected into the hepatic artery of animals on the seventh day after tumor implantation. At 1, 5, and 15 hr, after administration, five animals in each group were sacrificed and the ADR concentrations in the plasma, liver, heart, spleen, lungs, kidneys, and tumor were determined. The results showed that NADR substantially increased the ADR concentrations in liver, spleen, and tumor of rats compared to FADR, whereas the concentrations in plasma, heart, and lungs were significantly decreased. In conclusion, the body distribution of ADR can be modified by its encapsulation into nanoparticles and administration via the hepatic artery.

Rebound spiking in layer II medial entorhinal cortex stellate cells: Possible mechanism of grid cell function

PubMed Central

Shay, Christopher F.; Ferrante, Michele; Chapman, G. William; Hasselmo, Michael E.

2015-01-01

Rebound spiking properties of medial entorhinal cortex (mEC) stellate cells induced by inhibition may underlie their functional properties in awake behaving rats, including the temporal phase separation of distinct grid cells and differences in grid cell firing properties. We investigated rebound spiking properties using whole cell patch recording in entorhinal slices, holding cells near spiking threshold and delivering sinusoidal inputs, superimposed with realistic inhibitory synaptic inputs to test the capacity of cells to selectively respond to specific phases of inhibitory input. Stellate cells showed a specific phase range of hyperpolarizing inputs that elicited spiking, but non-stellate cells did not show phase specificity. In both cell types, the phase range of spiking output occurred between the peak and subsequent descending zero crossing of the sinusoid. The phases of inhibitory inputs that induced spikes shifted earlier as the baseline sinusoid frequency increased, while spiking output shifted to later phases. Increases in magnitude of the inhibitory inputs shifted the spiking output to earlier phases. Pharmacological blockade of h-current abolished the phase selectivity of hyperpolarizing inputs eliciting spikes. A network computational model using cells possessing similar rebound properties as found in vitro produces spatially periodic firing properties resembling grid cell firing when a simulated animal moves along a linear track. These results suggest that the ability of mEC stellate cells to fire rebound spikes in response to a specific range of phases of inhibition could support complex attractor dynamics that provide completion and separation to maintain spiking activity of specific grid cell populations. PMID:26385258

Disposition of [U-2H7]glucose into hepatic glycogen in rat and in seabass.

PubMed

Martins, Fátima O; Rito, João; Jarak, Ivana; Viegas, Ivan; Pardal, Miguel A; Macedo, M Paula; Jones, John G

2013-10-01

The stimulation of hepatic glycogenesis is a ubiquitous response to a glucose challenge and quantifying its contribution to glucose uptake informs its role in restoring euglycemia. Glycogenesis can be quantified with labeled water provided that exchange of glucose-6-phosphate hydrogen 2 (G6P-H2) and body water via glucose-6-phosphate isomerase, and exchange of positions 4, 5 and 6 hydrogens (G6P-H456) via transaldolase, are known. These exchanges were quantified in 24-h fasted rats (Rattus norvegicus; n=6) and 21-day fasted seabass (Dicentrarchus labrax; n=8) by administration of a glucose load (2000mg·kg(-1)) enriched with [U-(2)H7]glucose and by quantifying hepatic glycogen (2)H-enrichments after 2h (rats) and 48h (seabass). Direct pathway contributions of the glucose load to glycogenesis were also estimated. G6P-H2 and body water exchange was 61±1% for rat and 47±3% for seabass. Transaldolase-mediated exchange of G6P-H456 was 5±1% for rat and 10±1% for seabass. Conversion of the glucose load to hepatic glycogen was significant in seabass (249±54mg·kg(-1)) but negligible in rats (12±1mg·kg(-1)). Preload plasma glucose levels were similar for seabass and rats (3.3±0.7 and 4.4±0.1mmol·L(-1), respectively) but post-load plasma glucose was significantly higher in seabass compared to rats (14.6±1.8 versus 5.8±0.3mmol·L(-1), p<0.01). In conclusion, G6P-H2 and body water exchange is incomplete for both species and has to be accounted for in estimating hepatic glycogen synthesis and direct pathway activities with labeled water tracers. Transaldolase-mediated exchange is insignificant. Hepatic direct pathway glycogenesis plays a prominent role in seabass glucose load disposal, but a negligible role in the rat. © 2013.

Effects of Urtica dioica on hepatic ischemia-reperfusion injury in rats.

PubMed

Kandis, Hayati; Karapolat, Sami; Yildirim, Umran; Saritas, Ayhan; Gezer, Suat; Memisogullari, Ramazan

2010-01-01

To evaluate the effects of Urtica dioica on hepatic ischemia-reperfusion injury. Thirty adult male Wistar albino rats were divided into three groups: sham group (group 1), control group (group 2), and Urtica dioica group (group 3). All the rats were exposed to hepatic ischemia for 60 min, followed by 60 min of reperfusion. In group 2, a total of 2 ml/kg 0.9% saline solution was given intraperitoneally. In group 3, a total of 2 ml/kg Urtica dioica was given intraperitoneally. At the end of the procedure, liver tissue and blood samples were taken from all rats. Serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, ceruloplasmin, catalase, paraoxonase, arylesterase, and lipid hydroperoxide levels were measured. Liver tissue histopathologies were also evaluated by light microscopy. Serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels were significantly higher in group 2 than in group 1, and significantly lower in group 3 than in group 2. Also, group 2 had higher serum lipid hydroperoxides and ceruloplasmin levels but lower catalase, paraoxonase, and arylesterase levels than group 1. In group 3, serum lipid hydroperoxides and ceruloplasmin levels were significantly lower, and catalase, paraoxonase, and arylesterase levels were higher than those in group 2. Histopathological examination showed that liver tissue damage was significantly decreased in group 3 compared with group 2. Urtica dioica has a protective effect on the liver in hepatic ischemia-reperfusion-injured rats.

Effects of Urtica dioica on hepatic ischemia‐reperfusion injury in rats

PubMed Central

Kandis, Hayati; Karapolat, Sami; Yildirim, Umran; Saritas, Ayhan; Gezer, Suat; Memisogullari, Ramazan

2010-01-01

OBJECTIVES: To evaluate the effects of Urtica dioica on hepatic ischemia‐reperfusion injury. METHODS: Thirty adult male Wistar albino rats were divided into three groups: sham group (group 1), control group (group 2), and Urtica dioica group (group 3). All the rats were exposed to hepatic ischemia for 60 min, followed by 60 min of reperfusion. In group 2, a total of 2 ml/kg 0.9% saline solution was given intraperitoneally. In group 3, a total of 2 ml/kg Urtica dioica was given intraperitoneally. At the end of the procedure, liver tissue and blood samples were taken from all rats. Serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, ceruloplasmin, catalase, paraoxonase, arylesterase, and lipid hydroperoxide levels were measured. Liver tissue histopathologies were also evaluated by light microscopy. RESULTS: Serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels were significantly higher in group 2 than in group 1, and significantly lower in group 3 than in group 2. Also, group 2 had higher serum lipid hydroperoxides and ceruloplasmin levels but lower catalase, paraoxonase, and arylesterase levels than group 1. In group 3, serum lipid hydroperoxides and ceruloplasmin levels were significantly lower, and catalase, paraoxonase, and arylesterase levels were higher than those in group 2. Histopathological examination showed that liver tissue damage was significantly decreased in group 3 compared with group 2. CONCLUSIONS: Urtica dioica has a protective effect on the liver in hepatic ischemia‐reperfusion‐injured rats. PMID:21340227

Melatonin reduces dimethylnitrosamine-induced liver fibrosis in rats.

PubMed

Tahan, Veysel; Ozaras, Resat; Canbakan, Billur; Uzun, Hafize; Aydin, Seval; Yildirim, Beytullah; Aytekin, Huseyin; Ozbay, Gulsen; Mert, Ali; Senturk, Hakan

2004-09-01

Increased deposition of the extracellular matrix components, particularly collagen, is a central phenomenon in liver fibrosis. Stellate cells, the central mediators in the pathogenesis of fibrosis are activated by free radicals, and synthesize collagen. Melatonin is a potent physiological scavenger of hydroxyl radicals. Melatonin has also been shown to be involved in the inhibitory regulation of collagen content in tissues. At present, no effective treatment of liver fibrosis is available for clinical use. We aimed to test the effects of melatonin on dimethylnitrosamine (DMN)-induced liver damage in rats. Wistar albino rats were injected with DMN intraperitoneally. Following a single dose of 40 mg/kg DMN, either saline (DMN) or 100 mg/kg daily melatonin was administered for 14 days. In other rats, physiologic saline or melatonin were injected for 14 days, following a single injection of saline as control. Hepatic fibrotic changes were evaluated biochemically by measuring tissue hydroxyproline levels and histopathogical examination. Malondialdehyde (MDA), an end product of lipid peroxidation, and glutathione (GSH) and superoxide dismutase (SOD) levels were evaluated in blood and tissue homogenates. DMN caused hepatic fibrotic changes, whereas melatonin suppressed these changes in five of 14 rats (P < 0.05). DMN administration resulted in increased hydroxyproline and MDA levels, and decreased GSH and SOD levels, whereas melatonin reversed these effects. When melatonin was administered alone, no significant changes in biochemical parameters were noted. In conclusion, the present study suggests that melatonin functions as a potent fibrosuppressant and antioxidant, and may be a therapeutic choice.

Cytochrome P450 2E1 inhibition prevents hepatic carcinogenesis induced by diethylnitrosamine in alcohol-fed rats

USDA-ARS?s Scientific Manuscript database

Chronic alcohol ingestion increases hepatic cytochrome P450 2E1 (CYP2E1), which is associated with hepatocarcinogenesis. We investigated whether treatment with chlormethiazole (CMZ), a CYP2E1 inhibitor, protects against alcohol-associated hepatic carcinogenesis in rats. Rats were fed either an ethan...

Combined effect of sesamin and α-lipoic acid on hepatic fatty acid metabolism in rats.

PubMed

Ide, Takashi; Azechi, Ayana; Kitade, Sayaka; Kunimatsu, Yoko; Suzuki, Natsuko; Nakajima, Chihiro

2013-04-01

Dietary sesamin (1:1 mixture of sesamin and episesamin) decreases fatty acid synthesis but increases fatty acid oxidation in rat liver. Dietary α-lipoic acid lowers hepatic fatty acid synthesis. These changes can account for the serum lipid-lowering effect of sesamin and α-lipoic acid. It is expected that the combination of these compounds in the diet potentially ameliorates lipid metabolism more than the individual compounds. We therefore studied the combined effect of sesamin and α-lipoic acid on lipid metabolism in rats. Male Sprague-Dawley rats were fed diets supplemented with 0 or 2 g/kg sesamin and containing 0 or 2.5 g/kg α-lipoic acid for 22 days. Sesamin and α-lipoic acid decreased serum lipid concentrations and the combination of these compounds further decreased the parameters in an additive fashion. These compounds reduced the hepatic concentration of triacylglycerol, the lignan being less effective in decreasing this value. The combination failed to cause a stronger decrease in hepatic triacylglycerol concentration. The combination of sesamin and α-lipoic acid decreased the activity and mRNA levels of hepatic lipogenic enzymes in an additive fashion. Sesamin strongly increased the parameters of hepatic fatty acid oxidation enzymes. α-Lipoic acid antagonized the stimulating effect of sesamin of fatty acid oxidation through reductions in the activity of some fatty acid oxidation enzymes and carnitine concentration in the liver. This may account for the failure to observe strong reductions in hepatic triacylglycerol concentration in rats given a diet containing both sesamin and α-lipoic acid.

Dietary intake of ain-93 standard diet induces Fatty liver with altered hepatic fatty acid profile in Wistar rats.

PubMed

Farias Santos, Juliana; Suruagy Amaral, Monique; Lima Oliveira, Suzana; Porto Barbosa, Júnia; Rego Cabral, Cyro; Sofia Melo, Ingrid; Bezerra Bueno, Nassib; Duarte Freitas, Johnatan; Goulart Sant'ana, Antônio; Rocha Ataíde, Terezinha

2015-05-01

There are several standard diets for animals used in scientific research, usually conceived by scientific institutions. The AIN-93 diet is widely used, but there are some reports of fatty liver in Wistar rats fed this diet. We aimed to evaluate the hepatic repercussions of the AIN-93 diet intake in Wistar rats. Forty newly-weaned 21-day-old male Wistar rats were fed either the AIN-93 diet or a commercial diet for either 1 month or 4 months. Weight gain, serum biochemistry, hepatic histology, and hepatic fatty acid profile were analyzed. Hepatic steatosis was observed, especially in the group fed the AIN-93 diet. Serum blood glucose, absolute and relative liver weight and hepatic levels of oleic, palmitoleic, stearic, and palmitic fatty acids were related to the observed steatosis, while lipidogram and serum markers of liver function and injury were not. AIN-93 diet induced acute hepatic steatosis in Wistar rats, which may compromise its use as a standard diet for experimental studies with rodents. The hepatic fatty acid profile was associated with steatosis, with possible implications for disease prognosis. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Substance P promotes hepatic stellate cell proliferation and activation via the TGF-β1/Smad-3 signaling pathway.

PubMed

Peng, Lei; Jia, Xiaoqing; Zhao, Jianjian; Cui, Ruibing; Yan, Ming

2017-08-15

Prolonged activation and proliferation of hepatic stellate cells (HSCs) usually results in the initiation and progression of liver fibrosis following injury. Recent studies have shown that Substance P (SP) participates in the development of fibrosis. However, whether SP is involved in liver fibrosis, especially in the activation and proliferation of HSCs, is largely unknown. In the present study, we measured the effects of a series of concentrations of SP on the cell viability and activation of HSC-T6 cells and LX2 cells. The underlying mechanism was also investigated. We found that SP effectively increased cell viability, both in an MTT assay (p<0.05) and in a lactate dehydrogenase activity assay (LDH) (p<0.05). Moreover, SP upregulated the protein expression of α-SMA and Collagen I (both p<0.05) and decreased the release of lipid droplets (LDs) (p<0.05), all of which are associated with HSC activation. Apoptosis analysis revealed that SP can attenuate the increase of cell apoptosis induced by serum withdrawal (p<0.05). Furthermore, these effects were all blocked by an SP receptor antagonist, L732138. More importantly, L732138 decreased the activation of the TGF-β1/Smad3 signaling pathway, which is highly associated with liver fibrosis. Taken together, our results demonstrate that SP can promote HSC proliferation and induce HSC activation via the TGF-β1/Smad3 signaling pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

The regulatory effects of fish oil and chitosan on hepatic lipogenic signals in high-fat diet-induced obese rats.

PubMed

Chiu, Chen-Yuan; Chang, Tien-Chia; Liu, Shing-Hwa; Chiang, Meng-Tsan

2017-10-01

The present study investigated the regulatory effects of fish oil and chitosan on the signals of hepatic lipid metabolism and the postulated mechanism in high-fat diet-induced obese rats. Diet supplementation of chitosan and fish oil efficiently suppressed the increased weights in body and livers of high-fat diet-fed rats. Supplementation of chitosan and fish oil significantly decreased the activities of hepatic lipid biosynthesis-related enzymes and efficiently regulated plasma lipoprotein homeostasis. Both chitosan and fish oil significantly ameliorated the alterations in the protein expressions of hepatic lipogenic transcription factors (LXRα and PPARα), and could also significantly regulate the downstream hepatic lipogenic genes (FAS, HMGCR, CYP7A1, FATP, FABP, AOX, and ABCA) expressions in high-fat diet-fed rats. These results suggest that both fish oil and chitosan exerts downregulative effects on hepatic lipid metabolism in high-fat diet-induced obese rats via the LXRα inhibition and PPARα activation, which further affect the expressions of hepatic lipogenesis-associated genes. Copyright © 2017. Published by Elsevier B.V.

Activation of TGF-β1-CD147 positive feedback loop in hepatic stellate cells promotes liver fibrosis.

PubMed

Li, Hai-Yan; Ju, Di; Zhang, Da-Wei; Li, Hao; Kong, Ling-Min; Guo, Yanhai; Li, Can; Wang, Xi-Long; Chen, Zhi-Nan; Bian, Huijie

2015-11-12

Activation of hepatic stellate cells (HSCs) by transforming growth factor-β1 (TGF-β1) initiates HBV-associated fibrogenesis. The mechanism of TGF-β1 modulating HSC activation is not fully uncovered. We hypothesized a positive feedback signaling loop of TGF-β1-CD147 promoting liver fibrogenesis by activation of HSCs. Human HSC cell line LX-2 and spontaneous liver fibrosis model derived from HBV transgenic mice were used to evaluate the activation of molecules in the signaling loop. Wound healing and cell contraction assay were performed to detect the CD147-overexpressed HSC migration and contraction. The transcriptional regulation of CD147 by TGF-β1/Smad4 was determined using dual-luciferase reporter assay and chromatin immunoprecipitation. We found that a positive reciprocal regulation between TGF-β1 and CD147 mediated HSC activation. CD147 over-expression promoted HSC migration and accelerated TGF-β1-induced cell contraction. Phosphorylation of Smad2 and Smad3 in cooperation with Smad4 mediated the TGF-β1-regulated CD147 expression. Smad4 activated the transcription by direct interaction with CD147 promoter. Meanwhile, CD147 modulated the activated phenotype of HSCs through the ERK1/2 and Sp1 which up-regulated α-SMA, collagen I, and TGF-β1 synthesis. These findings indicate that TGF-β1-CD147 loop plays a key role in regulating the HSC activation and combination of TGF-β receptor inhibitor and anti-CD147 antibody might be promised to reverse fibrogenesis.

Activation of TGF-β1-CD147 positive feedback loop in hepatic stellate cells promotes liver fibrosis

PubMed Central

Li, Hai-Yan; Ju, Di; Zhang, Da-Wei; Li, Hao; Kong, Ling-Min; Guo, Yanhai; Li, Can; Wang, Xi-Long; Chen, Zhi-Nan; Bian, Huijie

2015-01-01

Activation of hepatic stellate cells (HSCs) by transforming growth factor-β1 (TGF-β1) initiates HBV-associated fibrogenesis. The mechanism of TGF-β1 modulating HSC activation is not fully uncovered. We hypothesized a positive feedback signaling loop of TGF-β1-CD147 promoting liver fibrogenesis by activation of HSCs. Human HSC cell line LX-2 and spontaneous liver fibrosis model derived from HBV transgenic mice were used to evaluate the activation of molecules in the signaling loop. Wound healing and cell contraction assay were performed to detect the CD147-overexpressed HSC migration and contraction. The transcriptional regulation of CD147 by TGF-β1/Smad4 was determined using dual-luciferase reporter assay and chromatin immunoprecipitation. We found that a positive reciprocal regulation between TGF-β1 and CD147 mediated HSC activation. CD147 over-expression promoted HSC migration and accelerated TGF-β1-induced cell contraction. Phosphorylation of Smad2 and Smad3 in cooperation with Smad4 mediated the TGF-β1-regulated CD147 expression. Smad4 activated the transcription by direct interaction with CD147 promoter. Meanwhile, CD147 modulated the activated phenotype of HSCs through the ERK1/2 and Sp1 which up-regulated α-SMA, collagen I, and TGF-β1 synthesis. These findings indicate that TGF-β1-CD147 loop plays a key role in regulating the HSC activation and combination of TGF-β receptor inhibitor and anti-CD147 antibody might be promised to reverse fibrogenesis. PMID:26559755

Targeted ablation of cardiac sympathetic neurons reduces resting, reflex and exercise-induced sympathetic activation in conscious rats.

PubMed

Lujan, Heidi L; Palani, Gurunanthan; Chen, Ying; Peduzzi, Jean D; Dicarlo, Stephen E

2009-05-01

Cholera toxin B subunit conjugated to saporin (SAP, a ribosomal inactivating protein that binds to and inactivates ribosomes) was injected in both stellate ganglia to evaluate the physiological response to targeted ablation of cardiac sympathetic neurons. Resting cardiac sympathetic activity (cardiac sympathetic tonus), exercise-induced sympathetic activity (heart rate responses to graded exercise), and reflex sympathetic activity (heart rate responses to graded doses of sodium nitroprusside, SNP) were determined in 18 adult conscious Sprague-Dawley male rats. Rats were randomly divided into the following three groups (n = 6/group): 1) control (no injection), 2) bilateral stellate ganglia injection of unconjugated cholera toxin B (CTB), and 3) bilateral stellate ganglia injection of cholera toxin B conjugated to SAP (CTB-SAP). CTB-SAP rats, compared with control and CTB rats, had reduced cardiac sympathetic tonus and reduced heart rate responses to graded exercise and graded doses of SNP. Furthermore, the number of stained neurons in the stellate ganglia and spinal cord (segments T(1)-T(4)) was reduced in CTB-SAP rats. Thus CTB-SAP retrogradely transported from the stellate ganglia is effective at ablating cardiac sympathetic neurons and reducing resting, exercise, and reflex sympathetic activity. Additional studies are required to further characterize the physiological responses to this procedure as well as determine if this new approach is safe and efficacious for the treatment of conditions associated with excess sympathetic activity (e.g., autonomic dysreflexia, hypertension, heart failure, and ventricular arrhythmias).

High dose lycopene supplementation increases hepatic cytochrome P4502E1 protein and inflammation in alcohol-fed rats.

PubMed

Veeramachaneni, Sudipta; Ausman, Lynne M; Choi, Sang Woon; Russell, Robert M; Wang, Xiang-Dong

2008-07-01

Recent in vitro evidence suggests that the antioxidant lycopene can prevent alcohol-induced oxidative stress and inflammation. However, knowledge of possible interactions in vivo between escalating doses of lycopene and chronic alcohol ingestion are lacking. In this study, we investigated potential interactions between alcohol ingestion and lycopene supplementation and their effect on hepatic lycopene concentration, cytochrome P4502E1 (CYP2E1) induction, and inflammation. Fischer 344 rats (6 groups, n = 10 per group) were fed either a liquid ethanol Lieber-DeCarli diet or a control diet (isocaloric maltodextrin substituted for ethanol) with or without lycopene supplementation at 2 doses (1.1 or 3.3 mg x kg body weight(-1) x d(-1)) for 11 wk. Plasma and hepatic concentrations of lycopene isomers were assessed by HPLC analysis. We examined expressions of hepatic CYP2E1 and tumor necrosis factor-alpha (TNFalpha) and the incidence of hepatic inflammatory foci. Both plasma and hepatic lycopene concentrations were greater in alcohol-fed rats than in control rats supplemented with identical doses of lycopene. In contrast, alcohol-fed rats had a lower percentage of lycopene cis isomers in the plasma and the liver compared with control rats fed the same dose of lycopene. Notably, lycopene supplementation at the higher dose significantly induced hepatic CYP2E1 protein, TNFalpha mRNA, and the incidence of inflammatory foci in the alcohol-fed rats but not in the control rats. These data indicate an interaction between chronic alcohol ingestion and lycopene supplementation and suggest a need for caution among individuals consuming high amounts of both alcohol and lycopene.

Non-linear Membrane Properties in Entorhinal Cortical Stellate Cells Reduce Modulation of Input-Output Responses by Voltage Fluctuations

PubMed Central

Fernandez, Fernando R.; Malerba, Paola; White, John A.

2015-01-01

The presence of voltage fluctuations arising from synaptic activity is a critical component in models of gain control, neuronal output gating, and spike rate coding. The degree to which individual neuronal input-output functions are modulated by voltage fluctuations, however, is not well established across different cortical areas. Additionally, the extent and mechanisms of input-output modulation through fluctuations have been explored largely in simplified models of spike generation, and with limited consideration for the role of non-linear and voltage-dependent membrane properties. To address these issues, we studied fluctuation-based modulation of input-output responses in medial entorhinal cortical (MEC) stellate cells of rats, which express strong sub-threshold non-linear membrane properties. Using in vitro recordings, dynamic clamp and modeling, we show that the modulation of input-output responses by random voltage fluctuations in stellate cells is significantly limited. In stellate cells, a voltage-dependent increase in membrane resistance at sub-threshold voltages mediated by Na+ conductance activation limits the ability of fluctuations to elicit spikes. Similarly, in exponential leaky integrate-and-fire models using a shallow voltage-dependence for the exponential term that matches stellate cell membrane properties, a low degree of fluctuation-based modulation of input-output responses can be attained. These results demonstrate that fluctuation-based modulation of input-output responses is not a universal feature of neurons and can be significantly limited by subthreshold voltage-gated conductances. PMID:25909971

Non-linear Membrane Properties in Entorhinal Cortical Stellate Cells Reduce Modulation of Input-Output Responses by Voltage Fluctuations.

PubMed

Fernandez, Fernando R; Malerba, Paola; White, John A

2015-04-01

The presence of voltage fluctuations arising from synaptic activity is a critical component in models of gain control, neuronal output gating, and spike rate coding. The degree to which individual neuronal input-output functions are modulated by voltage fluctuations, however, is not well established across different cortical areas. Additionally, the extent and mechanisms of input-output modulation through fluctuations have been explored largely in simplified models of spike generation, and with limited consideration for the role of non-linear and voltage-dependent membrane properties. To address these issues, we studied fluctuation-based modulation of input-output responses in medial entorhinal cortical (MEC) stellate cells of rats, which express strong sub-threshold non-linear membrane properties. Using in vitro recordings, dynamic clamp and modeling, we show that the modulation of input-output responses by random voltage fluctuations in stellate cells is significantly limited. In stellate cells, a voltage-dependent increase in membrane resistance at sub-threshold voltages mediated by Na+ conductance activation limits the ability of fluctuations to elicit spikes. Similarly, in exponential leaky integrate-and-fire models using a shallow voltage-dependence for the exponential term that matches stellate cell membrane properties, a low degree of fluctuation-based modulation of input-output responses can be attained. These results demonstrate that fluctuation-based modulation of input-output responses is not a universal feature of neurons and can be significantly limited by subthreshold voltage-gated conductances.

The small stellated dodecahedron code and friends.

PubMed

Conrad, J; Chamberland, C; Breuckmann, N P; Terhal, B M

2018-07-13

We explore a distance-3 homological CSS quantum code, namely the small stellated dodecahedron code, for dense storage of quantum information and we compare its performance with the distance-3 surface code. The data and ancilla qubits of the small stellated dodecahedron code can be located on the edges respectively vertices of a small stellated dodecahedron, making this code suitable for three-dimensional connectivity. This code encodes eight logical qubits into 30 physical qubits (plus 22 ancilla qubits for parity check measurements) in contrast with one logical qubit into nine physical qubits (plus eight ancilla qubits) for the surface code. We develop fault-tolerant parity check circuits and a decoder for this code, allowing us to numerically assess the circuit-based pseudo-threshold.This article is part of a discussion meeting issue 'Foundations of quantum mechanics and their impact on contemporary society'. © 2018 The Authors.

Effects of perinatal exposure to nonylphenol on delivery outcomes of pregnant rats and inflammatory hepatic injury in newborn rats

PubMed Central

Yu, J.; Luo, Y.; Yang, X.F.; Yang, M.X.; Yang, J.; Yang, X.S.; Zhou, J.; Gao, F.; He, L.T.; Xu, J.

2016-01-01

The current study aimed to investigate the effects of perinatal exposure to nonylphenol (NP) on delivery outcome of pregnant rats and subsequent inflammatory hepatic injury in newborn rats. The pregnant rats were divided into 2 groups: control group (corn oil) and NP exposure group. Thirty-four pregnant rats were administered NP or corn oil by gavage from the sixth day of pregnancy to 21 days postpartum, with blood samples collected at 12 and 21 days of pregnancy and 60 days after delivery. The NP concentration was measured by HPLC, with chemiluminescence used for detection of estrogen and progesterone levels. Maternal delivery parameters were also observed. Liver and blood of the newborn rats were collected and subjected to automatic biochemical detection of liver function and blood lipid analyzer (immunoturbidimetry), and ultrastructural observation of the hepatic microstructure, with the TNF-α and IL-1β hepatic tissue levels evaluated by immunohistochemistry. Compared with the control group, the pregnant and postpartum serum NP and estradiol levels of the mother rats in the NP group were significantly increased, together with lowered progesterone level, increased number of threatened abortion and dystocia, and fewer newborn rats and lower litter weight. Serum and hepatic NP levels of the newborn rats measured 60 days after birth were significantly higher than those of the control group, as well as lower testosterone levels and increased estradiol levels. When observed under electron microscope, the hepatocyte nuclei of the control group were large and round, with evenly distributed chromatin. The chromatin of hepatocytes in the NP group presented deep staining of the nuclei, significant lipid decrease in the cytoplasm, and the majority of cells bonded with lysate. The results of immunohistochemistry showed that there was almost no TNF-α or IL-1β expression in the hepatocytes of the control group, while the number of TNF-α-, PCNA-, and IL-1β-positive cells

Hepatic damage in newborns from female rats exposed to the pesticide derivative ethylenethiourea.

PubMed

Lemos, Patrícia Veruska Ribeiro Barbosa; Martins, José Luiz; Lemos, Sidney Pereira Pinto; Santos, Fernando Leandro dos; Silva, Sílvio Romero Gonçalves e

2012-12-01

To evaluate hepatic morphological-histological abnormalities in newborns from female rats exposed to ethylenethiourea. A randomized study was conducted on fifty-five newborn Wistar rats were studied: 34 in the experimental group, whose mothers had been exposed to 1% ethylenethiourea; and 21 in the control group, whose mothers had received 0.9% physiological solution. The solution was administered via gavage on the 11(th) day of gestation. Cesarean section was performed on the 20(th) day of gestation. The newborns' livers were examined and any morphological-histological abnormalities were registered. The presence of megakaryocytes was quantified in 50 microscope fields, as the total number of these cells per mm(2). The entire experimental group presented abnormalities of embryonic formation, with musculoskeletal anomalies, digestive system anomalies, hepatic congestion and friability, hydrops and delayed intrauterine growth. The histopathological analysis showed that morphological-histological hepatic destructuring had occurred in all entire experimental with removal of the hepatic trabeculae and severe hepatic megakaryocytosis. The mean megakaryocyte density ranged from 107.9 to 114.2 per mm(2), and it was eight times greater than in the control group, thus characterizing a situation of extramedullary hematopoiesis. The fetal exposure to ethylenethiourea caused hepatic damage characterized by severe extramedullary hematopoiesis.

Sub-acute deltamethrin and fluoride toxicity induced hepatic oxidative stress and biochemical alterations in rats.

PubMed

Dubey, Nitin; Khan, Adil Mehraj; Raina, Rajinder

2013-09-01

The current study investigated the effects of deltamethrin, fluoride (F(-)) and their combination on the hepatic oxidative stress and consequent alterations in blood biochemical markers of hepatic damage in rats. Significant hepatic oxidative stress and hepatic damage were observed in the toxicant exposed groups. These changes were higher in the deltamethrin-F(-) co-exposure treatment group, depicting a positive interaction between the two chemicals.

Docosahexaenoic acid attenuates Western diet-induced hepatic fibrosis in Ldlr−/− mice by targeting the TGFβ-Smad3 pathway[S

PubMed Central

Lytle, Kelli A.; Depner, Christopher M.; Wong, Carmen P.; Jump, Donald B.

2015-01-01

DHA (22:6,ω3), but not EPA (20:5,ω3), attenuates Western diet (WD)-induced hepatic fibrosis in a Ldlr−/− mouse model of nonalcoholic steatohepatitis. We examined the molecular basis for the differential effect of dietary EPA and DHA on WD-induced hepatic fibrosis. DHA was more effective than EPA at preventing WD-induced effects on hepatic transcripts linked to fibrosis, including collagen 1A1 (Col1A1), transforming growth factor-β (TGFβ) signaling and proteins involved in remodeling the extracellular matrix, including metalloproteases, tissue inhibitors of metalloproteases, and lysyl oxidase subtypes. Examination of the TGFβ pathway showed that mice fed the WD supplemented with either olive oil or EPA had a significant (≥2.5-fold) increase in hepatic nuclear abundance of phospho-mothers against decapentaplegic homolog (Smad)3 when compared with mice fed the reference diet (RD); Smad3 is a key regulator of Col1A1 expression in stellate cells. In contrast, mice fed the WD supplemented with DHA had no increase in phospho-Smad3 when compared with mice fed the RD. Changes in hepatic phospho-Smad3 nuclear content correlated with proCol1A1 mRNA and protein abundance. Pretreatment of human LX2 stellate cells with DHA, but not other unsaturated fatty acids, blocked TGFβ1-mediated induction of Col1A1. In conclusion, DHA attenuates WD-induced fibrosis by targeting the TGFβ-Smad3-Col1A1 pathway in stellate cells. PMID:26315048

The pancreatic stellate cell: a star on the rise in pancreatic diseases

PubMed Central

Omary, M. Bishr; Lugea, Aurelia; Lowe, Anson W.; Pandol, Stephen J.

2007-01-01

Pancreatic stellate cells (PaSCs) are myofibroblast-like cells found in the areas of the pancreas that have exocrine function. PaSCs are regulated by autocrine and paracrine stimuli and share many features with their hepatic counterparts, studies of which have helped further our understanding of PaSC biology. Activation of PaSCs induces them to proliferate, to migrate to sites of tissue damage, to contract and possibly phagocytose, and to synthesize ECM components to promote tissue repair. Sustained activation of PaSCs has an increasingly appreciated role in the fibrosis that is associated with chronic pancreatitis and with pancreatic cancer. Therefore, understanding the biology of PaSCs offers potential therapeutic targets for the treatment and prevention of these diseases. PMID:17200706

Hepatic Stellate Cells Orchestrate Clearance of Necrotic Cells in a HIF-1α-dependent Manner by Modulating Macrophage Phenotype in Mice

PubMed Central

Rockwell, Cheryl E.; Roth, Katherine J.; Chow, Aaron; O'Brien, Kate M; Albee, Ryan; Kelly, Kara; Towery, Keara; Luyendyk, James P.; Copple, Bryan L.

2014-01-01

Hypoxia-inducible factor-1α (HIF-1α) is activated in hepatic stellate cells (HSCs) by hypoxia, and regulates genes important for tissue repair. Whether HIF-1α is activated in HSCs after acute injury and contributes to liver regeneration, however, is not known. To investigate this, mice were generated with reduced levels of HIF-1α in HSCs by crossing HIF-1α floxed mice with mice that express Cre recombinase under control of the glial fibrillary acidic protein (GFAP) promoter (i.e., HIF-1α-GFAP Cre+ mice). These mice and control mice (i.e., HIF-1α-GFAP Cre- mice) were treated with a single dose of carbon tetrachloride, and liver injury and repair were assessed. After carbon tetrachloride, HIF-1α was activated in HSCs. Although liver injury was not different between the two strains of mice, during resolution of injury, clearance of necrotic cells was decreased in HIF-1α-GFAP Cre+ mice. In these mice, the persistence of necrotic cells stimulated a fibrotic response characterized by extensive collagen deposition. Hepatic accumulation of macrophages, which clear necrotic cells from the liver after carbon tetrachloride, was not affected by HIF-1α deletion in HSCs. Conversion of macrophages to M1-like, pro-inflammatory macrophages, which have increased phagocytic activity, however, was reduced in HIF-1α-GFAP Cre+ mice as indicated by a decrease in pro-inflammatory cytokines, and a decrease in the percentage of Gr1hi macrophages. Collectively, these studies have identified a novel function for HSCs and HIF-1α in orchestrating the clearance of necrotic cells from the liver, and demonstrated a key role for HSCs in modulating macrophage phenotype during acute liver injury. PMID:24639359

Regulation of hepatic level of fatty-acid-binding protein by hormones and clofibric acid in the rat.

PubMed Central

Nakagawa, S; Kawashima, Y; Hirose, A; Kozuka, H

1994-01-01

Regulation of the hepatic level of fatty-acid-binding protein (FABP) by hormones and p-chlorophenoxyisobutyric acid (clofibric acid) was studied. The hepatic level of FABP, measured as the oleic acid-binding capacity of the cytosolic FABP fraction, was decreased in streptozotocin-diabetic rats. The level of FABP was markedly increased in adrenalectomized rats, and the elevation was prevented by the administration of dexamethasone. Hypothyroidism decreased the level of FABP and hyperthyroidism increased it. A high correlation between the incorporation of [14C]oleic acid in vivo into hepatic triacylglycerol and the level of FABP was found for normal, diabetic and adrenalectomized rats. The level of FABP was increased by administration of clofibric acid to rats in any altered hormonal states, as was microsomal 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase, a peroxisome-proliferator-responsive parameter. These results suggest that the hepatic level of FABP is under regulation by multiple hormones and that clofibric acid induces FABP and 1-acyl-GPC acyltransferase by a mechanism which may be distinct from that by which hormones regulate the level of FABP. PMID:8110197

Entorhinal stellate cells show preferred spike phase-locking to theta inputs that is enhanced by correlations in synaptic activity

PubMed Central

Fernandez, Fernando R.; Malerba, Paola; Bressloff, Paul C.; White, John A.

2013-01-01

In active networks, excitatory and inhibitory synaptic inputs generate membrane voltage fluctuations that drive spike activity in a probabilistic manner. Despite this, some cells in vivo show a strong propensity to precisely lock to the local field potential and maintain a specific spike-phase relationship relative to other cells. In recordings from rat medial entorhinal cortical stellate cells, we measured spike phase-locking in response to sinusoidal “test” inputs in the presence of different forms of background membrane voltage fluctuations, generated via dynamic clamp. We find that stellate cells show strong and robust spike phase-locking to theta (4–12 Hz) inputs. This response occurs under a wide variety of background membrane voltage fluctuation conditions that include a substantial increase in overall membrane conductance. Furthermore, the IH current present in stellate cells is critical to the enhanced spike phase-locking response at theta. Finally, we show that correlations between inhibitory and excitatory conductance fluctuations, which can arise through feed-back and feed-forward inhibition, can substantially enhance the spike phase-locking response. The enhancement in locking is a result of a selective reduction in the size of low frequency membrane voltage fluctuations due to cancelation of inhibitory and excitatory current fluctuations with correlations. Hence, our results demonstrate that stellate cells have a strong preference for spike phase-locking to theta band inputs and that the absolute magnitude of locking to theta can be modulated by the properties of background membrane voltage fluctuations. PMID:23554484

Hyperandrogenism and insulin resistance contribute to hepatic steatosis and inflammation in female rat liver

PubMed Central

Zhang, Yuehui; Meng, Fanci; Sun, Xiaoyan; Sun, Xue; Hu, Min; Cui, Peng; Vestin, Edvin; Li, Xin; Li, Wei; Wu, Xiao-Ke; Jansson, John-Olov; Shao, Linus R.; Billig, Håkan

2018-01-01

Women with polycystic ovary syndrome (PCOS) are at high risk for nonalcoholic fatty liver disease (NAFLD). While insulin resistance is a common trait for both PCOS and NAFLD, hyperandrogenism is also considered to be a key factor contributing to PCOS, and the molecular mechanisms behind the interactions between insulin resistance and hyperandrogenism in the female liver remain largely unexplored. Using chronic treatment with insulin and/or human chorionic gonadotropin (hCG), we showed that all female rats with different treatments induced imbalance between de novo lipogenesis and mitochondrial β-oxidation via the Pparα/β–Srebp1/2–Acc1 axis, resulting in varying degrees of hepatic steatosis. Given the fact that hepatic lipid metabolism and inflammation are tightly linked processes, we found that hCG-induced hyperandrogenic rats had strongly aggravated hepatic inflammation. Further mechanistic investigations revealed that dysregulation of the IRS–PI3K–Akt signaling axis that integrated aberrant inflammatory, apoptotic and autophagic responses in the liver was strongly associated with hyperandrogenism itself or combined with insulin resistance. Additionally, we found that hCG-treated and insulin+hCG-induced rats developed visceral adipose tissue inflammation characterized by the presence of “crown like” structure and increased inflammatory gene expression. Because a more pronounced hepatic steatosis, inflammatory responses, and hepatocyte cell damage were observed in insulin+hCG-induced PCOS-like rats, our finding suggest that NAFLD seen in PCOS patients is dependent of hyperandrogenism and insulin resistance. PMID:29719598

Monounsaturated fat decreases hepatic lipid content in non-alcoholic fatty liver disease in rats

PubMed Central

Hussein, Osamah; Grosovski, Masha; Lasri, Etti; Svalb, Sergio; Ravid, Uzi; Assy, Nimer

2007-01-01

AIM: To evaluate the effects of different types of dietary fats on the hepatic lipid content and oxidative stress parameters in rat liver with experimental non-alcoholic fatty liver disease (NAFLD). METHODS: A total of 32 Sprague-Dawley rats were randomly divided into five groups. The rats in the control group (n = 8) were on chow diet (Group 1), rats (n = 6) on methionine choline-deficient diet (MCDD) (Group 2), rats (n = 6) on MCDD enriched with olive oil (Group 3), rats (n = 6) on MCDD with fish oil (Group 4) and rats (n = 6) on MCDD with butter fat (Group 5). After 2 mo, blood and liver sections were examined for lipids composition and oxidative stress parameters. RESULTS: The liver weight/rat weight ratio increased in all treatment groups as compared with the control group. Severe fatty liver was seen in MCDD + fish oil and in MCDD + butter fat groups, but not in MCDD and MCDD + olive oil groups. The increase in hepatic triglycerides (TG) levels was blunted by 30% in MCDD + olive oil group (0.59 ± 0.09) compared with MCDD group (0.85 ± 0.04, p < 0.004), by 37% compared with MCDD + fish oil group (0.95 ± 0.07, p < 0.001), and by 33% compared with MCDD + butter group (0.09 ± 0.1, p < 0.01). The increase in serum TG was lowered by 10% in MCDD + olive oil group (0.9 ± 0.07) compared with MCDD group (1.05 ± 0.06). Hepatic cholesterol increased by 15-fold in MCDD group [(0.08 ± 0.02, this increment was blunted by 21% in MCDD + fish oil group (0.09 ± 0.02)]. In comparison with the control group, ratio of long-chain polyunsaturated fatty acids omega-6/omega-3 increased in MCDD + olive oil, MCDD + fish oil and MCDD + butter fat groups by 345-, 30- and 397-fold, respectively. In comparison to MCDD group (1.58 ± 0.08), hepatic MDA contents in MCDD + olive oil (3.3 ± 0.6), MCDD + fish oil (3.0 ± 0.4), and MCDD + butter group (2.9 ± 0.36) were increased by 108%, 91% and 87%, respectively (p < 0.004). Hepatic paraoxonase activity decreased significantly in all

Protective effect of Piper betle leaf extract against cadmium-induced oxidative stress and hepatic dysfunction in rats

PubMed Central

Milton Prabu, S.; Muthumani, M.; Shagirtha, K.

2012-01-01

The present study was undertaken to examine the attenuative effect of Piper betle leaf extract (PBE) against cadmium (Cd) induced oxidative hepatic dysfunction in the liver of rats. Pre-oral supplementation of PBE (200 mg/kg BW) treated rats showed the protective efficacy against Cd induced hepatic oxidative stress. Oral administration of Cd (5 mg/kg BW) for four weeks to rats significantly (P > 0.05) elevated the level of serum hepatic markers such as serum aspartate transaminase (AST), serum alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), gamma-glutamyl transpeptidase (GGT), bilirubin (TBRNs), oxidative stress markers viz., thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH), protein carbonyls (PC) and conjugated dienes (CD) and significantly (P > 0.05) reduced the enzymatic antioxidants viz., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PD) and non-enzymatic antioxidants Viz., reduced glutathione (GSH), total sulfhydryls (TSH), vitamin C and vitamin E in the liver. Pre-oral supplementation of PBE (200 mg/kg BW) in Cd intoxicated rats, the altered biochemical indices and pathological changes were recovered significantly (P > 0.05) which showed ameliorative effect of PBE against Cd induced hepatic oxidative stress. From the above findings, we suggested that the pre-administration of P. betle leaf extract exhibited remarkable protective effects against cadmium-induced oxidative hepatic injury in rats. PMID:23961183

Protective effect of Piper betle leaf extract against cadmium-induced oxidative stress and hepatic dysfunction in rats.

PubMed

Milton Prabu, S; Muthumani, M; Shagirtha, K

2012-04-01

The present study was undertaken to examine the attenuative effect of Piper betle leaf extract (PBE) against cadmium (Cd) induced oxidative hepatic dysfunction in the liver of rats. Pre-oral supplementation of PBE (200 mg/kg BW) treated rats showed the protective efficacy against Cd induced hepatic oxidative stress. Oral administration of Cd (5 mg/kg BW) for four weeks to rats significantly (P > 0.05) elevated the level of serum hepatic markers such as serum aspartate transaminase (AST), serum alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), gamma-glutamyl transpeptidase (GGT), bilirubin (TBRNs), oxidative stress markers viz., thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH), protein carbonyls (PC) and conjugated dienes (CD) and significantly (P > 0.05) reduced the enzymatic antioxidants viz., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PD) and non-enzymatic antioxidants Viz., reduced glutathione (GSH), total sulfhydryls (TSH), vitamin C and vitamin E in the liver. Pre-oral supplementation of PBE (200 mg/kg BW) in Cd intoxicated rats, the altered biochemical indices and pathological changes were recovered significantly (P > 0.05) which showed ameliorative effect of PBE against Cd induced hepatic oxidative stress. From the above findings, we suggested that the pre-administration of P. betle leaf extract exhibited remarkable protective effects against cadmium-induced oxidative hepatic injury in rats.

Intrahepatic upregulation of MRTF-A signaling contributes to increased hepatic vascular resistance in cirrhotic rats with portal hypertension.

PubMed

Zheng, Lei; Qin, Jun; Sun, Longci; Gui, Liang; Zhang, Chihao; Huang, Yijun; Deng, Wensheng; Huang, An; Sun, Dong; Luo, Meng

2017-06-01

Portal hypertension in cirrhosis is mediated, in part, by increased intrahepatic resistance, reflecting massive structural changes associated with fibrosis and intrahepatic vasoconstriction. Activation of the Rho/MRTF/SRF signaling pathway is essential for the cellular regulatory network of fibrogenesis. The aim of this study was to investigate MRTF-A-mediated regulation of intrahepatic fibrogenesis in cirrhotic rats. Portal hypertension was induced in rats via an injection of CCl 4 oil. Hemodynamic measurements were obtained using a polyethylene PE-50 catheter and pressure transducers. Expression of hepatic fibrogenesis was measured using histological staining. Expression of protein was measured using western blotting. Upregulation of MRTF-A protein expression in the livers of rats with CCl 4 -induced cirrhosis was relevant to intrahepatic resistance and hepatic fibrogenesis in portal hypertensive rats with increased modeling time. Inhibition of MRTF-A by CCG-1423 decelerated hepatic fibrosis, decreased intrahepatic resistance and portal pressure, and alleviated portal hypertension. Increased intrahepatic resistance in rats with CCl 4 -induced portal hypertension is associated with an upregulation of MRTF-A signaling. Inhibition of this pathway in the liver can decrease hepatic fibrosis and intrahepatic resistance, as well as reduce portal pressure in cirrhotic rats with CCl 4 -induced portal hypertension. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

The role of hepatic mitochondria in the regulation of glucose metabolism in BHE rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, M.J.C.

The interacting effects of dietary fat source and thyroxine treatment on the hepatic mitochondrial function and glucose metabolism were studied. In the first study, three different sources of dietary fatty acids and thyroxine treatment were used to investigate the hepatic mitochondrial thermotropic behavior in two strains of rat. The NIDDM BHE and Sprague-Dawley rats were used. Feeding coconut oil increased serum T{sub 4} levels and T{sub 4} treatment increased serum T{sub 3} levels in the BHE rats. In the mitochondria from BHE rats fed coconut oil and treated with T{sub 4}, the transition temperature disappeared due to a decoupling ofmore » succinate supported respiration. This was not observed in the Sprague-Dawley rats. In the second study, two different sources of dietary fat and T{sub 4} treatment were used to investigate hepatic mitochondrial function. Coconut oil feeding increased Ca{sup ++}Mg{sup ++}ATPase and Mg{sup ++}ATPase. T{sub 4} treatment had potentiated this effect. T{sub 4} increased the malate-aspartate shuttle and {alpha}-glycerophosphate shuttle activities. In the third study, the glucose turnover rate from D-({sup 14}C-U)/(6-{sup 3}H)-glucose and gluconeogeneis from L-({sup 14}C-U)-alanine was examined. Dietary fat or T{sub 4} did not affect the glucose mass. T{sub 4} increased the irreversible fractional glucose turnover rate.« less

Oxidative stress plays a role in high glucose-induced activation of pancreatic stellate cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryu, Gyeong Ryul; Lee, Esder; Chun, Hyun-Ji

Highlights: •High glucose increased production of reactive oxygen species in cultured pancreatic stellate cells. •High glucose facilitated the activation of these cells. •Antioxidant treatment attenuated high glucose-induced activation of these cells. -- Abstract: The activation of pancreatic stellate cells (PSCs) is thought to be a potential mechanism underlying islet fibrosis, which may contribute to progressive β-cell failure in type 2 diabetes. Recently, we demonstrated that antioxidants reduced islet fibrosis in an animal model of type 2 diabetes. However, there is no in vitro study demonstrating that high glucose itself can induce oxidative stress in PSCs. Thus, PSCs were isolated andmore » cultured from Sprague Dawley rats, and treated with high glucose for 72 h. High glucose increased the production of reactive oxygen species. When treated with high glucose, freshly isolated PSCs exhibited myofibroblastic transformation. During early culture (passage 1), PSCs treated with high glucose contained an increased number of α-smooth muscle actin-positive cells. During late culture (passages 2–5), PSCs treated with high glucose exhibited increases in cell proliferation, the expression of fibronectin and connective tissue growth factor, release of interleukin-6, transforming growth factor-β and collagen, and cell migration. Finally, the treatment of PSCs with high glucose and antioxidants attenuated these changes. In conclusion, we demonstrated that high glucose increased oxidative stress in primary rat PSCs, thereby facilitating the activation of these cells, while antioxidant treatment attenuated high glucose-induced PSC activation.« less

Hepatic focal nodular hyperplasia with congenital portosystemic shunt.

PubMed

Cho, Yuki; Shimono, Taro; Morikawa, Hiroyasu; Shintaku, Haruo; Tokuhara, Daisuke

2014-12-01

Hepatic focal nodular hyperplasia (FNH) is a rare benign tumor in children. Vascular anomalies have been identified as pathological features of FNH, but the etiology remains unclear. We describe a rare case including the time course of formation of hepatic FNH in response to congenital portosystemic shunt (PSS). A 4-month-old girl was identified on newborn mass screening to have hypergalactosemia, but no inherited deficiencies in galactose-metabolizing enzymes were found. Ultrasonography and per-rectal portal scintigraphy showed intrahepatic PSS of the right lobe as a cause of the hypergalactosemia. At age 12 months, the patient had elevated hepatic enzymes and small hypoechoic hepatic lesions around the shunt. On abdominal contrast-enhanced ultrasonography spoke-wheel sign and central stellate scar were seen, which are typical features of hepatic FNH without biopsy. Congenital intrahepatic PSS should be evaluated on abdominal contrast-enhanced ultrasonography and observed over time because of its potential to develop into hepatic FNH. © 2014 Japan Pediatric Society.

Effects of 4-nonylphenol on oxidant/antioxidant balance system inducing hepatic steatosis in male rat.

PubMed

Kourouma, Ansoumane; Keita, Hady; Duan, Peng; Quan, Chao; Bilivogui, Koikoi Kebe; Qi, Suqin; Christiane, Ndjiembi Adjonga; Osamuyimen, Aidogie; Yang, Kedi

2015-01-01

An emerging literature suggests that early life exposure to 4-nonylphenol (4-NP), a widespread endocrine disrupting chemical, may increase the risk of metabolic syndrome. In this study, we investigated the hypothesis that intraperitoneal administration of 4-NP induces hepatic steatosis in rat. 24 male Sprague-Dawley rats were administered with 4-NP (0, 2, 10 and 50 mg/kg b.wt) in corn oil for 30 days. Liver histology, biochemical analysis and gene expression profiling were examined. After treatment, abnormal liver morphology and function were observed in the 4-NP-treated rat, and significant changes in gene expression an indicator of hepatic steatosis and apoptosis were observed compared with controls. Up-regulated genes involved in apoptosis, hepatotoxity and oxidative stress, increased ROS and decrease of antioxidant enzyme were observed in the 4-NP exposed rat. Extensive fatty accumulation in liver section and elevated serum GOT, GPT, LDH and γ-GT were also observed. Incidence and severity of liver steatosis was scored and taken into consideration (steatosis, ballooning and lobular inflammation). Hepatocytes apoptosis could promote NAFLD progression; Fas/FasL, TNF-α and Caspase-9 mRNA activation were important contributing factors to hepatic steatosis. These findings provide the first evidence that 4-NP affects the gene expression related to liver hepatotoxicity, which is correlated with hepatic steatosis.

Differing Distribution of Hepatocyte Growth Factor‐positive Cells in the Liver of LEC Rats with Acute Hepatitis, Chronic Hepatitis and Hepatoma

PubMed Central

Kashiwazaki, Haruhiko; Kobayashi, Narumi; Hamada, Jun‐ichi; Matsumoto, Kunio; Nakamura, Toshikazu; Takeichi, Noritoshi

1995-01-01

Using anti‐rat hepatocyte growth factor (HGF) antibody, we investigated the distribution of HGF‐positive cells in the liver tissues of LEC rats at various phases of liver diseases. During the phase of fulminant hepatitis, HGF‐positive cells increased remarkably, and many of them were localized at the portal triads; these cells were identified from their shape as non‐epithelial cells. A reduced number of HGF‐positive cells was observed during the phase of chronic hepatitis, while no HGF‐positive cells were seen in the tissue of cholangiofibrosis. During the phase of carcinoma, staining revealed that both the hepatocellular carcinoma cells and the non‐epithelial cells in cancerous liver tissue were HGF‐positive. These results suggest that, in LEC rats, HGF may play an important role in the regeneration of hepatocytes as well as in the development of hepatocellular carcinoma. PMID:7737910

Magnolol Attenuates Concanavalin A-induced Hepatic Fibrosis, Inhibits CD4+ T Helper 17 (Th17) Cell Differentiation and Suppresses Hepatic Stellate Cell Activation: Blockade of Smad3/Smad4 Signalling.

PubMed

Zhang, Hongjun; Ju, Baoling; Zhang, Xiaoli; Zhu, Yanfei; Nie, Ying; Xu, Yuanhong; Lei, Qiuxia

2017-06-01

Magnolol is a pharmacological biphenolic compound extracted from Chinese herb Magnolia officinalis, which displays anti-inflammatory and antioxidant effects. This study was aimed at exploring the potential effect of magnolol on immune-related liver fibrosis. Herein, BALB/c mice were injected with concanavalin A (ConA, 8 mg/kg/week) up to 6 weeks to establish hepatic fibrosis, and magnolol (10, 20, 30 mg/kg/day) was given to these mice orally throughout the whole experiment. We found that magnolol preserved liver function and attenuated liver fibrotic injury in vivo. In response to ConA stimulation, the CD4 + T cells preferred to polarizing towards CD4 + T helper 17 (Th17) cells in liver. Magnolol was observed to inhibit Th17 cell differentiation in ConA-treated liver in addition to suppressing interleukin (IL)-17A generation. Hepatic stellate cells were activated in fibrotic liver as demonstrated by increased alpha smooth muscle actin (α-SMA) and desmin. More transforming growth factor (TGF)-β1 and activin A were secreted into the serum. Magnolol suppressed this abnormal HSC activation. Furthermore, the phosphorylation of Smad3 in its linker area (Thr179, Ser 204/208/213) was inhibited by magnolol. In vitro, the recombinant IL-17A plus TGF-β1 or activin A induced activation of human LX2 HSCs and promoted their collagen production. Smad3/Smad4 signalling pathway was activated in LX2 cells exposed to the fibrotic stimuli, as illustrated by the up-regulated phospho-Smad3 and the enhanced interaction between Smad3 and Smad4. These alterations were suppressed by magnolol. Collectively, our study reveals a novel antifibrotic effect of magnolol on Th17 cell-mediated fibrosis. © 2017 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

Methylation of Septin9 mediated by DNMT3a enhances hepatic stellate cells activation and liver fibrogenesis.

PubMed

Wu, Yuting; Bu, Fangtian; Yu, Haixia; Li, Wanxia; Huang, Cheng; Meng, Xiaoming; Zhang, Lei; Ma, Taotao; Li, Jun

2017-01-15

Liver fibrosis, resulting from chronic and persistent injury to the liver, is a worldwide health problem. Advanced liver fibrosis results in cirrhosis, liver failure and even hepatocellular cancer (HCC), often eventually requiring liver transplantation, poses a huge health burden on the global community. However, the specific pathogenesis of liver fibrosis remains not fully understood. Numerous basic and clinical studies have provided evidence that epigenetic modifications, especially DNA methylation, might contribute to the activation of hepatic stellate cells (HSCs), the pivotal cell type responsible for the fibrous scar in liver. Here, reduced representation bisulfite sequencing (RRBS) and bisulfite pyrosequencing PCR (BSP) analysis identified hypermethylation status of Septin9 (Sept9) gene in liver fibrogenesis. Sept9 protein was dramatically decreased in livers of CCl4-treated mice and immortalized HSC-T6 cells exposed to TGF-β1. Nevertheless, the suppression of Sept9 could be blocked by DNMT3a-siRNA and DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (5-azadC). Overexpressed Sept9 attenuated TGF-β1-induced expression of myofibroblast markers α-SMA and Col1a1, accompanied by up-regulation of cell apoptosis-related proteins. Conversely, RNAi-mediated silencing of Sept9 enhanced accumulation of extracellular matrix. These observations suggested that Sept9 contributed to alleviate liver fibrosis might partially through promoting activated HSCs apoptosis and this anti-fibrogenesis effect might be blocked by DNMT-3a mediated methylation of Sept9. Therefore, pharmacological agents that inhibit Sept9 methylation and increase its expression could be considered as valuable treatments for liver fibrosis. Copyright © 2016 Elsevier Inc. All rights reserved.

Fasting inhibits hepatic stellate cells activation and potentiates anti-cancer activity of Sorafenib in hepatocellular cancer cells.

PubMed

Lo Re, Oriana; Panebianco, Concetta; Porto, Stefania; Cervi, Carlo; Rappa, Francesca; Di Biase, Stefano; Caraglia, Michele; Pazienza, Valerio; Vinciguerra, Manlio

2018-02-01

Hepatocellular carcinoma (HCC) has a poor outcome. Most HCCs develop in the context of liver fibrosis and cirrhosis caused by chronic inflammation. Short-term fasting approaches enhance the activity of chemotherapy in preclinical cancer models, other than HCC. Multi-tyrosine kinase inhibitor Sorafenib is the mainstay of treatment in HCC. However, its benefit is frequently short-lived. Whether fasting can alleviate liver fibrosis and whether combining fasting with Sorafenib is beneficial remains unknown. A 24 hr fasting (2% serum, 0.1% glucose)-induced changes on human hepatic stellate cells (HSC) LX-2 proliferation/viability/cell cycle were assessed by MTT and flow cytometry. Expression of lypolysaccharide (LPS)-induced activation markers (vimentin, αSMA) was evaluated by qPCR and immunoblotting. Liver fibrosis and inflammation were evaluated in a mouse model of steatohepatitis exposed to cycles of fasting, by histological and biochemical analyses. A 24 hr fasting-induced changes were also analyzed on the proliferation/viability/glucose uptake of human HCC cells exposed to Sorafenib. An expression panel of genes involved in survival, inflammation, and metabolism was examined by qPCR in HCC cells exposed to fasting and/or Sorafenib. Fasting decreased the proliferation and the activation of HSC. Repeated cycles of short term starvation were safe in mice but did not improve fibrosis. Fasting synergized with Sorafenib in hampering HCC cell growth and glucose uptake. Finally, fasting normalized the expression levels of genes which are commonly altered by Sorafenib in HCC cells. Fasting or fasting-mimicking diet diets should be evaluated in preclinical studies as a mean to potentiate the activity of Sorafenib in clinical use. © 2017 Wiley Periodicals, Inc.

STELLATE NONHEREDITARY IDIOPATHIC FOVEOMACULAR RETINOSCHISIS ACCOMPANIED BY CONTRALATERAL PERIPHERAL RETINOSCHISIS.

PubMed

Ahmed, Daniel; Stattin, Martin; Glittenberg, Carl; Krebs, Ilse; Ansari-Shahrezaei, Siamak

2017-01-16

To present a patient with stellate nonhereditary idiopathic foveomacular retinoschisis on one eye and peripheral retinoschisis without foveal affection on the other eye. A case report with complete workup of family history and clinical examination, including multimodal imaging with optical coherence tomography and angiography, fluorescein angiography, and infrared fundus imaging. Genetic testing for gene mutation XRLS1 was performed. A white woman with unremarkable medical history presented with stellate foveal splitting of the outer plexiform layer on the right eye and peripheral splitting of the outer plexiform layer on both eyes. All known allegeable trigger factors for the existence of a hereditary or acquired foveomacular retinoschisis were ruled out either by clinical presentation or genetic testing. This led to the diagnosis of stellate nonhereditary idiopathic foveomacular retinoschisis with central involvement only present on one eye. Although peripheral schisis of the outer plexiform layer is often concomitant with central splitting in X-linked juvenile retinoschisis, this is the first known report of nonhereditary cleavage of the outer plexiform layer of the peripheral retina without central affection in a patient with documented stellate nonhereditary idiopathic foveomacular retinoschisis on the other eye. These findings suggest an accurate bilateral examination of the peripheral retina while confirming the diagnose of stellate nonhereditary idiopathic foveomacular retinoschisis.

Liver Cell-Derived Microparticles Activate Hedgehog Signaling and Alter Gene Expression in Hepatic Endothelial Cells

PubMed Central

Witek, Rafal P.; Yang, Liu; Liu, Renshui; Jung, Youngmi; Omenetti, Alessia; Syn, Wing-Kin; Choi, Steve S.; Cheong, Yeiwon; Fearing, Caitlin M.; Agboola, Kolade M.; Chen, Wei; Diehl, Anna Mae

2013-01-01

Background & Aims Angiogenesis contributes to vascular remodeling during cirrhosis. In cirrhotic livers, cholangiocytes and myofibroblastic hepatic stellate cells (MF-HSC) produce Hedgehog (Hh) ligands. During embryogenesis Hh ligands are released from ligand-producing cells in microparticles and activate Hh signaling in endothelial cells. We studied whether adult liver cell-derived microparticles contain Hh ligands that alter hepatic sinusoidal endothelial cells (SEC). Methods MF-HSCs and cholangiocytes were exposed to platelet-derived growth factor (PDGF) to induce Hh ligands; microparticles were isolated from medium, analyzed by transmission electron microscopy (TEM) and immunoblots, and applied to Hh-reporter containing cells. Microparticles were also obtained from serum and bile of rats after bile duct ligation (BDL) or sham surgery and applied to normal primary liver SEC with or without cyclopamine, a Hh signaling inhibitor. Effects on SEC gene expression were evaluated by QRT-PCR and immunoblotting. Finally, Hh target gene expression and SEC activation markers were compared in primary SEC and in liver sections from healthy and BDL rats. Results PDGF-treated MF-HSC and cholangiocytes released exosome-enriched microparticles containing biologically active Hh ligands. BDL also increased release of Hh-containing exosome-enriched microparticles into plasma and bile. TEM and immunoblots revealed similarities among microparticles from all sources; all microparticles induced similar Hh-dependent changes in SEC gene expression. SEC from healthy livers did not express Hh target genes or activation markers, but both were up-regulated in SEC after BDL. Conclusions Hh-containing exosome-enriched microparticles released from liver cells alter hepatic SEC gene expression, suggesting a novel mechanism for cirrhotic vasculopathy. PMID:19013163

Liver cell-derived microparticles activate hedgehog signaling and alter gene expression in hepatic endothelial cells.

PubMed

Witek, Rafal P; Yang, Liu; Liu, Renshui; Jung, Youngmi; Omenetti, Alessia; Syn, Wing-Kin; Choi, Steve S; Cheong, Yeiwon; Fearing, Caitlin M; Agboola, Kolade M; Chen, Wei; Diehl, Anna Mae

2009-01-01

Angiogenesis contributes to vascular remodeling during cirrhosis. In cirrhotic livers, cholangiocytes, and myofibroblastic hepatic stellate cells (MF-HSC) produce Hedgehog (Hh) ligands. During embryogenesis Hh ligands are released from ligand-producing cells in microparticles and activate Hh signaling in endothelial cells. We studied whether adult liver cell-derived microparticles contain Hh ligands that alter hepatic sinusoidal endothelial cells (SEC). MF-HSC and cholangiocytes were exposed to platelet-derived growth factor to induce Hh ligands; microparticles were isolated from medium, analyzed by transmission electron microscopy and immunoblots, and applied to Hh-reporter-containing cells. Microparticles were obtained from serum and bile of rats after bile duct ligation (BDL) or sham surgery and applied to normal primary liver SEC with or without cyclopamine, an Hh signaling inhibitor. Effects on SEC gene expression were evaluated by quantitative reverse-transcription polymerase chain reaction and immunoblotting. Hh target gene expression and SEC activation markers were compared in primary SEC and in liver sections from healthy and BDL rats. Platelet-derived growth factor-treated MF-HSC and cholangiocytes released exosome-enriched microparticles containing biologically-active Hh ligands. BDL increased release of Hh-containing exosome-enriched microparticles into plasma and bile. Transmission electron microscopy and immunoblots revealed similarities among microparticles from all sources; all microparticles induced similar Hh-dependent changes in SEC gene expression. SEC from healthy livers did not express Hh target genes or activation markers, but both were up-regulated in SEC after BDL. Hh-containing exosome-enriched microparticles released from liver cells alter hepatic SEC gene expression, suggesting a novel mechanism for cirrhotic vasculopathy.

Ischemic Preconditioning Increases the Tolerance of Fatty Liver to Hepatic Ischemia-Reperfusion Injury in the Rat

PubMed Central

Serafín, Anna; Roselló-Catafau, Joan; Prats, Neus; Xaus, Carme; Gelpí, Emilio; Peralta, Carmen

2002-01-01

Hepatic steatosis is a major risk factor in ischemia-reperfusion. The present study evaluates whether preconditioning, demonstrated to be effective in normal livers, could also confer protection in the presence of steatosis and investigates the potential underlying protective mechanisms. Fatty rats had increased hepatic injury and decreased survival after 60 minutes of ischemia compared with lean rats. Fatty livers showed a degree of neutrophil accumulation and microcirculatory alterations similar to that of normal livers. However, in presence of steatosis, an increased lipid peroxidation that could be reduced with glutathione-ester pretreatment was observed after hepatic reperfusion. Ischemic preconditioning reduced hepatic injury and increased animal survival. Both in normal and fatty livers, this endogenous protective mechanism was found to control lipid peroxidation, hepatic microcirculation failure, and neutrophil accumulation, reducing the subsequent hepatic injury. These beneficial effects could be mediated by nitric oxide, because the inhibition of nitric oxide synthesis and nitric oxide donor pretreatment abolished and simulated, respectively, the benefits of preconditioning. Thus, ischemic preconditioning could be an effective surgical strategy to reduce the hepatic ischemia-reperfusion injury in normal and fatty livers under normothermic conditions, including hepatic resections, and liver transplantation. PMID:12163383

Enhanced antitumor efficacy on hepatoma-bearing rats with adriamycin-loaded nanoparticles administered into hepatic artery.

PubMed

Chen, Jiang-Hao; Ling, Rui; Yao, Qing; Wang, Ling; Ma, Zhong; Li, Yu; Wang, Zhe; Xu, Hu

2004-07-01

To investigate the antitumor activity of adriamycin (ADR) encapsulated in nanoparticles (NADR) and injected into the hepatic artery of hepatoma-bearing rats. NADR was prepared by the interfacial polymerization method. Walker-256 carcinosarcomas were surgically implanted into the left liver lobes of 60 male Wistar rats, which were divided into 4 groups at random (15 rats per group). On the 7th day after implantation, normal saline (NS), free ADR (FADR), NADR, or ADR mixed with unloaded nanoparticles (ADR+NP) was respectively injected via the hepatic artery (i.a.) of rats in different groups. The dose of ADR in each formulation was 2.0 mg/kg body weight and the concentration was 1.0 mg/mL. Survival time, tumor enlargement ratio, and tumor necrosis degree were compared between each group. Compared with the rats that received NS i.a., the rats that received FADR or ADR+NP acquired apparent inhibition on tumor growth, as well as prolonged their life span. Further significant anticancer efficacy was observed in rats that received i.a. administration of NADR. Statistics indicated that NADR brought on a more significant tumor inhibition and more extensive tumor necrosis, as compared to FADR or ADR+NP. The mean tumor enlargement ratio on the 7th day after NADR i.a. was 1.106. The mean tumor-bearing survival time was 39.50 days. Prolonged life span ratio was 109.22% as compared with rats that accepted NS. Therapeutic effect of ADR on liver malignancy can be significantly enhanced by its nanopaticle formulation and administration via hepatic artery.

Aerobic capacity and hepatic mitochondrial lipid oxidation alters susceptibility for chronic high-fat diet-induced hepatic steatosis.

PubMed

Morris, E Matthew; Meers, Grace M E; Koch, Lauren G; Britton, Steven L; Fletcher, Justin A; Fu, Xiaorong; Shankar, Kartik; Burgess, Shawn C; Ibdah, Jamal A; Rector, R Scott; Thyfault, John P

2016-10-01

Rats selectively bred for high capacity running (HCR) or low capacity running (LCR) display divergence for intrinsic aerobic capacity and hepatic mitochondrial oxidative capacity, both factors associated with susceptibility for nonalcoholic fatty liver disease. Here, we tested if HCR and LCR rats display differences in susceptibility for hepatic steatosis after 16 wk of high-fat diets (HFD) with either 45% or 60% of kcals from fat. HCR rats were protected against HFD-induced hepatic steatosis, whereas only the 60% HFD induced steatosis in LCR rats, as marked by a doubling of liver triglycerides. Hepatic complete fatty acid oxidation (FAO) and mitochondrial respiratory capacity were all lower in LCR compared with HCR rats. LCR rats also displayed lower hepatic complete and incomplete FAO in the presence of etomoxir, suggesting a reduced role for noncarnitine palmitoyltransferase-1-mediated lipid catabolism in LCR versus HCR rats. Hepatic complete FAO and mitochondrial respiration were largely unaffected by either chronic HFD; however, 60% HFD feeding markedly reduced 2-pyruvate oxidation, a marker of tricarboxylic acid (TCA) cycle flux, and mitochondrial complete FAO only in LCR rats. LCR rats displayed lower levels of hepatic long-chain acylcarnitines than HCR rats but maintained similar levels of hepatic acetyl-carnitine levels, further supporting lower rates of β-oxidation, and TCA cycle flux in LCR than HCR rats. Finally, only LCR rats displayed early reductions in TCA cycle genes after the acute initiation of a HFD. In conclusion, intrinsically high aerobic capacity confers protection against HFD-induced hepatic steatosis through elevated hepatic mitochondrial oxidative capacity.

Aerobic capacity and hepatic mitochondrial lipid oxidation alters susceptibility for chronic high-fat diet-induced hepatic steatosis

PubMed Central

Morris, E. Matthew; Meers, Grace M. E.; Koch, Lauren G.; Britton, Steven L.; Fletcher, Justin A.; Fu, Xiaorong; Shankar, Kartik; Burgess, Shawn C.; Ibdah, Jamal A.; Rector, R. Scott

2016-01-01

Rats selectively bred for high capacity running (HCR) or low capacity running (LCR) display divergence for intrinsic aerobic capacity and hepatic mitochondrial oxidative capacity, both factors associated with susceptibility for nonalcoholic fatty liver disease. Here, we tested if HCR and LCR rats display differences in susceptibility for hepatic steatosis after 16 wk of high-fat diets (HFD) with either 45% or 60% of kcals from fat. HCR rats were protected against HFD-induced hepatic steatosis, whereas only the 60% HFD induced steatosis in LCR rats, as marked by a doubling of liver triglycerides. Hepatic complete fatty acid oxidation (FAO) and mitochondrial respiratory capacity were all lower in LCR compared with HCR rats. LCR rats also displayed lower hepatic complete and incomplete FAO in the presence of etomoxir, suggesting a reduced role for noncarnitine palmitoyltransferase-1-mediated lipid catabolism in LCR versus HCR rats. Hepatic complete FAO and mitochondrial respiration were largely unaffected by either chronic HFD; however, 60% HFD feeding markedly reduced 2-pyruvate oxidation, a marker of tricarboxylic acid (TCA) cycle flux, and mitochondrial complete FAO only in LCR rats. LCR rats displayed lower levels of hepatic long-chain acylcarnitines than HCR rats but maintained similar levels of hepatic acetyl-carnitine levels, further supporting lower rates of β-oxidation, and TCA cycle flux in LCR than HCR rats. Finally, only LCR rats displayed early reductions in TCA cycle genes after the acute initiation of a HFD. In conclusion, intrinsically high aerobic capacity confers protection against HFD-induced hepatic steatosis through elevated hepatic mitochondrial oxidative capacity. PMID:27600823

Urotensin II modulates hepatic fibrosis and portal hemodynamic alterations in rats.

PubMed

Kemp, William; Kompa, Andrew; Phrommintikul, Arintaya; Herath, Chandana; Zhiyuan, Jia; Angus, Peter; McLean, Catriona; Roberts, Stuart; Krum, Henry

2009-10-01

The influence of circulating urotensin II (UII) on liver disease and portal hypertension is unknown. We aimed to evaluate whether UII executes a pathogenetic role in the development of hepatic fibrosis and portal hypertension. UII was administered by continuous infusion over 4 wk in 20 healthy rats divided into three treatment groups, controls (saline, n = 7), low dose (UII, 1 nmol x kg(-1) x h(-1), n = 8), and high dose (UII, 3 nmol x kg(-1) x h(-1), n = 5). Hemodynamic parameters and morphometric quantification of fibrosis were assessed, and profibrotic cytokines and fibrosis markers were assayed in hepatic tissue. UII induced a significant dose-dependent increase in portal venous pressure (5.8 +/- 0.4, 6.4 +/- 0.3, and 7.6 +/- 0.7, respectively, P = 0.03). High-dose UII infusion was associated with an increase in hepatic transcript for transforming growth factor-beta (P < 0.05) and platelet-derived growth factor-beta (P = 0.06). Liver tissue hydroxyproline was elevated in the high-dose group (P < 0.05). No systemic hemodynamic alterations were noted. We concluded that UII infusion elevates portal pressure and induces hepatic fibrosis in normal rats. This response may be mediated via induction of fibrogenic cytokines. These findings have pathophysiological implications in human liver disease where increased plasma UII levels have been observed.

Roles of nuclear receptors in the up-regulation of hepatic cholesterol 7alpha-hydroxylase by cholestyramine in rats.

PubMed

Shibata, Shinya; Hayakawa, Kazuhito; Egashira, Yukari; Sanada, Hiroo

2007-01-16

Nuclear receptors are involved in regulating the expression of cholesterol 7alpha-hydroxylase (CYP7A1), however, their roles in the up-regulation of CYP7A1 by cholestyramine (CSR) are still unclear. In the present study, male Wistar rats were divided into four groups and fed [high sucrose + 10% lard diet] (H), [H + 3% CSR diet] (H + CSR), [H + 0.5% cholesterol + 0.25% sodium cholate diet] (C), or [C + 3% CSR diet] (C + CSR) for 2 weeks. Cholestyramine decreased serum and liver cholesterol levels significantly in rats fed C-based diets, but had no effect on these parameters in rats fed H-based diets. Cholestyramine raised hepatic levels of CYP7A1 mRNA and activity in both groups. The gene expression of hepatic ATP-binding cassettes A1 and G5, regulated by liver X receptor (LXR), were unchanged and down-regulated by cholestyramine, respectively. The mRNA levels of the hepatic ATP-binding cassette B11 and short heterodimer partner (SHP), regulated by farnesoid X receptor (FXR), were not changed by cholestyramine. C-based diets, which contained cholesterol and cholic acid, increased SHP mRNA levels compared to H-based diets. Consequently, in rats fed the C+CSR diet, hepatic FXR was activated by dietary bile acids, but the hepatic CYP7A1 mRNA level was increased 16-fold compared to that in rats fed an H diet. These results suggest that cholestyramine up-regulates the expression of CYP7A1 independently via LXR- or FXR-mediated pathways in rats.

High prevalence of rat hepatitis E virus in wild rats in China.

PubMed

Li, Wei; Guan, Dawei; Su, Juan; Takeda, Naokazu; Wakita, Takaji; Li, Tian-Cheng; Ke, Chang Wen

2013-08-30

Serum samples from a total of 713 wild rats captured in Zhanjiang city in China from December 2011 to September 2012 were investigated for the prevalence of rat hepatitis E virus (HEV) by exploring rat HEV-specific antibodies and RNA. By an ELISA based on recombinant rat HEV-like particles (HEV-LPs), 23.3% (166/713) of the rats were positive for anti-HEV IgG, and 8.3% (59/713) were positive for anti-HEV IgM. The IgG-positive rates in Rattus norvegicus, Bandicota indica, Rattus flavipectus, Rattus rattoides losea, and Rattus rattus hainanus, were 27.8% (64/230), 23.0% (40/174), 19.9% (34/171), 21.5% (26/121), and 11.8% (2/17), while the IgM-positive rates were 8.3% (19/230), 6.9% (12/174), 8.2% (14/171), 10.7% (13/121), and 5.9% (1/17), respectively. The IgG-positive rate of the rats captured in rural areas, 24.1% (84/348), was higher than that in the central area of Zhanjiang city, 15.1% (32/212). The highest IgG-positive rates, as high as 45.3% (39/86), were detected in wild rats trapped in the garbage dump. Twelve of the 59 IgM-positive serum samples were positive for HEV RNA, which was detected in all of the wild rat species except R. rattus hainanus. A phylogenetic analysis of the partial genome of rat HEV ORF1 indicated that all of the 12 HEV strains belong to rat HEV, and no other genotype HEV were detected. The rat HEV from Zhangjiang city could be classified into three separated clusters, suggesting that the infection due to rat HEV with a variety of genome entities occurs extensively among wild rats in China. Copyright © 2013 Elsevier B.V. All rights reserved.

Curcumin inhibits gene expression of receptor for advanced glycation end-products (RAGE) in hepatic stellate cells in vitro by elevating PPARγ activity and attenuating oxidative stress

PubMed Central

Lin, Jianguo; Tang, Youcai; Kang, Qiaohua; Feng, Yunfeng; Chen, Anping

2012-01-01

BACKGROUND AND PURPOSE Diabetes is characterized by hyperglycaemia, which facilitates the formation of advanced glycation end-products (AGEs). Type 2 diabetes mellitus is commonly accompanied by non-alcoholic steatohepatitis, which could lead to hepatic fibrosis. Receptor for AGEs (RAGE) mediates effects of AGEs and is associated with increased oxidative stress, cell growth and inflammation. The phytochemical curcumin inhibits the activation of hepatic stellate cells (HSCs), the major effectors during hepatic fibrogenesis. The aim of this study was to explore the underlying mechanisms of curcumin in the elimination of the stimulating effects of AGEs on the activation of HSCs. We hypothesize that curcumin eliminates the effects of AGEs by suppressing gene expression of RAGE. EXPERIMENTAL APPROACH Gene promoter activities were evaluated by transient transfection assays. The expression of rage was silenced by short hairpin RNA. Gene expression was analysed by real-time PCR and Western blots. Oxidative stress was evaluated. KEY RESULTS AGEs induced rage expression in cultured HSCs, which played a critical role in the AGEs-induced activation of HSCs. Curcumin at 20 µM eliminated the AGE effects, which required the activation of PPARγ. In addition, curcumin attenuated AGEs-induced oxidative stress in HSCs by elevating the activity of glutamate-cysteine ligase and by stimulating de novo synthesis of glutathione, leading to the suppression of gene expression of RAGE. CONCLUSION AND IMPLICATIONS Curcumin suppressed gene expression of RAGE by elevating the activity of PPARγ and attenuating oxidative stress, leading to the elimination of the AGE effects on the activation of HSCs. LINKED ARTICLE This article is commented on by Stefanska, pp. 2209–2211 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2012.01959.x PMID:22352842

Morphology and Molecular Mechanisms of Hepatic Injury in Rats under Simulated Weightlessness and the Protective Effects of Resistance Training.

PubMed

Du, Fang; Ding, Ye; Zou, Jun; Li, Zhili; Tian, Jijing; She, Ruiping; Wang, Desheng; Wang, Huijuan; Lv, Dongqiang; Chang, Lingling

2015-01-01

This study investigated the effects of long-term simulated weightlessness on liver morphology, enzymes, glycogen, and apoptosis related proteins by using two-month rat-tail suspension model (TS), and liver injury improvement by rat-tail suspension with resistance training model (TS&RT). Microscopically the livers of TS rats showed massive granular degeneration, chronic inflammation, and portal fibrosis. Mitochondrial and endoplasmic reticulum swelling and loss of membrane integrity were observed by transmission electron microscopy (TEM). The similar, but milder, morphological changes were observed in the livers of TS&RT rats. Serum biochemistry analysis revealed that the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly higher (p<0.05) in TS rats than in controls. The levels of ALT and AST in TS&RT rats were slightly lower than in RT rats, but they were insignificantly higher than in controls. However, both TS and TS&RT rats had significantly lower levels (p<0.05) of serum glucose and hepatic glycogen than in controls. Immunohistochemistry demonstrated that the expressions of Bax, Bcl-2, and active caspase-3 were higher in TS rats than in TS&RT and control rats. Real-time polymerase chain reaction (real-time PCR) showed that TS rats had higher mRNA levels (P < 0.05) of glucose-regulated protein 78 (GRP78) and caspase-12 transcription than in control rats; whereas mRNA expressions of C/EBP homologous protein (CHOP) and c-Jun N-terminal kinase (JNK) were slightly higher in TS rats. TS&RT rats showed no significant differences of above 4 mRNAs compared with the control group. Our results demonstrated that long-term weightlessness caused hepatic injury, and may trigger hepatic apoptosis. Resistance training slightly improved hepatic damage.

Morphology and Molecular Mechanisms of Hepatic Injury in Rats under Simulated Weightlessness and the Protective Effects of Resistance Training

PubMed Central

Zou, Jun; Li, Zhili; Tian, Jijing; She, Ruiping; Wang, Desheng; Wang, Huijuan; Lv, Dongqiang; Chang, Lingling

2015-01-01

This study investigated the effects of long-term simulated weightlessness on liver morphology, enzymes, glycogen, and apoptosis related proteins by using two-month rat-tail suspension model (TS), and liver injury improvement by rat-tail suspension with resistance training model (TS&RT). Microscopically the livers of TS rats showed massive granular degeneration, chronic inflammation, and portal fibrosis. Mitochondrial and endoplasmic reticulum swelling and loss of membrane integrity were observed by transmission electron microscopy (TEM). The similar, but milder, morphological changes were observed in the livers of TS&RT rats. Serum biochemistry analysis revealed that the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly higher (p<0.05) in TS rats than in controls. The levels of ALT and AST in TS&RT rats were slightly lower than in RT rats, but they were insignificantly higher than in controls. However, both TS and TS&RT rats had significantly lower levels (p<0.05) of serum glucose and hepatic glycogen than in controls. Immunohistochemistry demonstrated that the expressions of Bax, Bcl-2, and active caspase-3 were higher in TS rats than in TS&RT and control rats. Real-time polymerase chain reaction (real-time PCR) showed that TS rats had higher mRNA levels (P < 0.05) of glucose-regulated protein 78 (GRP78) and caspase-12 transcription than in control rats; whereas mRNA expressions of C/EBP homologous protein (CHOP) and c-Jun N-terminal kinase (JNK) were slightly higher in TS rats. TS&RT rats showed no significant differences of above 4 mRNAs compared with the control group. Our results demonstrated that long-term weightlessness caused hepatic injury, and may trigger hepatic apoptosis. Resistance training slightly improved hepatic damage. PMID:26000905

TSA increases C/EBP‑α expression by increasing its lysine acetylation in hepatic stellate cells.

PubMed

Tao, Li-Li; Ding, Di; Yin, Wei-Hua; Peng, Ji-Ying; Hou, Chen-Jian; Liu, Xiu-Ping; Chen, Yao-Li

2017-11-01

CCAAT enhancer binding protein‑α (C/EBP‑α) is a transcription factor expressed only in certain tissues, including the liver. It has been previously demonstrated that C/EBP‑α may induce apoptosis in hepatic stellate cells (HSCs), raising the question of whether acetylation of C/EBP‑α is associated with HSCs, and the potential associated mechanism. A total of three histone deacetylase inhibitors (HDACIs), including trichostatin A (TSA), suberoylanilide hydroxamic acid and nicotinamide, were selected to determine whether acetylation affects C/EBP‑α expression. A Cell Counting Kit‑8 assay was used to determine the rate of proliferation inhibition following treatment with varying doses of the three HDACIs in HSC‑T6 and BRL‑3A cells. Western blot analysis was used to examine Caspase‑3, ‑8, ‑9, and ‑12 levels in HSC‑T6 cells treated with adenoviral‑C/EBP‑α and/or TSA. Following treatment with TSA, a combination of reverse transcription‑quantitative polymerase chain reaction and western blot analyses was used to determine the inherent C/EBP‑α mRNA and protein levels in HSC‑T6 cells at 0, 1, 2, 4, 8, 12, 24, 36 and 48 h. Nuclear and cytoplasmic proteins were extracted to examine C/EBP‑α distribution. Co‑immunoprecipitation analysis was used to examine the lysine acetylation of C/EBP‑α. It was observed that TSA inhibited the proliferation of HSC‑T6 cells to a greater extent compared with BRL‑3A cells, following treatment with the three HDACIs. TSA induced apoptosis in HSC‑T6 cells and enhanced the expression of C/EBP‑α. Following treatment of HSC‑T6 cells with TSA, inherent C/EBP‑α expression increased in a time‑dependent manner, and its lysine acetylation simultaneously increased. Therefore, the results of the present study suggested that TSA may increase C/EBP‑α expression by increasing its lysine acetylation in HSCs.

MiR-29b inhibits collagen maturation in hepatic stellate cells through down-regulating the expression of HSP47 and lysyl oxidase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yifei; Ghazwani, Mohammed; Li, Jiang

Highlights: • Enhanced HSP47 and LOX expression is associated with decreased miR-29b level in liver fibrosis. • miR-29b down-regulates HSP47 and LOX expression. • The suppression of HSP47 and LOX by miR-29b is mediated by putative sites at their 3′-UTRs. • miR-29b inhibits extracellular LOX activity and collagen maturation. - Abstract: Altered expression of miR-29b is implicated in the pathogenesis and progression of liver fibrosis. We and others previously demonstrated that miR-29b down-regulates the expression of several extracellular-matrix (ECM) genes including Col 1A1, Col 3A1 and Elastin via directly targeting their 3′-UTRs. However, whether or not miR-29b plays a rolemore » in the post-translational regulation of ECM biosynthesis has not been reported. Heat shock protein 47 (HSP47) and lysyl oxidase (LOX) are known to be essential for ECM maturation. In this study we have demonstrated that expression of HSP47 and LOX was significantly up-regulated in culture-activated primary rat hepatic stellate cells (HSCs), TGF-β stimulated LX-2 cells and liver tissue of CCl{sub 4}-treated mice, which was accompanied by a decrease of miR-29b level. In addition, over-expression of miR-29b in LX-2 cells resulted in significant inhibition on HSP47 and LOX expression. Mechanistically, miR-29b inhibited the expression of a reporter gene that contains the respective full-length 3′-UTR from HSP47 and LOX gene, and this inhibitory effect was abolished by the deletion of a putative miR-29b targeting sequence from the 3′-UTRs. Transfection of LX-2 cells with miR-29b led to abnormal collagen structure as shown by electron-microscopy, presumably through down-regulation of the expression of molecules involved in ECM maturation including HSP47 and LOX. These results demonstrated that miR-29b is involved in regulating the post-translational processing of ECM and fibril formation.« less

Age dependent in vitro metabolism of bifenthrin in rat and human hepatic microsomes.

PubMed

Nallani, Gopinath C; Chandrasekaran, Appavu; Kassahun, Kelem; Shen, Li; ElNaggar, Shaaban F; Liu, Zhiwei

2018-01-01

Bifenthrin, a pyrethroid insecticide, undergoes oxidative metabolism leading to the formation of 4'-hydroxy-bifenthrin (4'-OH-BIF) and hydrolysis leading to the formation of TFP acid in rat and human hepatic microsomes. In this study, age-dependent metabolism of bifenthrin in rats and humans were determined via the rates of formation of 4'-OH-BIF and TFP acid following incubation of bifenthrin in juvenile and adult rat (PND 15 and PND 90) and human (<5years and >18years) liver microsomes. Furthermore, in vitro hepatic intrinsic clearance (CL int ) of bifenthrin was determined by substrate consumption method in a separate experiment. The mean V max (±SD) for the formation of 4'-OH-BIF in juvenile rat hepatic microsomes was 25.0±1.5pmol/min/mg which was significantly lower (p<0.01) compared to that of adult rats (86.0±17.7pmol/min/mg). However, the mean K m values for juvenile (19.9±6.6μM) and adult (23.9±0.4μM) rat liver microsomes were similar. On the other hand, in juvenile human hepatic microsomes, V max for the formation of 4'-OH-BIF (73.9±7.5pmol/min/mg) was significantly higher (p<0.05) than that of adults (21.6±0.6pmol/min/mg) albeit similar K m values (10.5±2.8μM and 8.9±0.6μM) between the two age groups. The trends in the formation kinetics of TFP acid were similar to those of 4'-OH-BIF between the species and age groups, although the differences between juveniles and adults were less pronounced. The data also show that metabolism of bifenthrin occurs primarily via oxidative pathway with relatively lesser contribution (~30%) from hydrolytic pathway in both rat and human liver microsomes. The CL int values for bifenthrin, determined by monitoring the consumption of substrate, in juvenile and adult rat liver microsomes fortified with NADPH were 42.0±7.2 and 166.7±20.5μl/min/mg, respectively, and the corresponding values for human liver microsomes were 76.0±4.0 and 21.3±1.2μl/min/mg, respectively. The data suggest a major species difference

Effect of dietary supplementation of grape skin and seeds on liver fibrosis induced by dimethylnitrosamine in rats

PubMed Central

Shin, Mi-Ok

2010-01-01

Grape is one of the most popular and widely cultivated fruits in the world. Although grape skin and seeds are waste product of the winery and grape juice industry, these wastes contain large amounts of phytochemicals such as flavonoids, phenolic acids, and anthocyanidins, which play an important role as chemopreventive and anticancer agents. We evaluated efficacies of grape skin and seeds on hepatic injury induced by dimethylnitrosamine (DMN) in rats. Treatment with DMN significantly increased levels of serum alanine transaminase, aspartate transaminase, alkaline phosphatase, and bilirubin. Diet supplementation with grape skin or seeds (10% daily for 4 weeks) prevented these elevations. The grape skin and seeds also restored serum albumin and total protein levels, and reduced the hepatic level of hydroxyproline and malondialdehyde. Furthermore, grape skin and seeds reduced DMN-induced collagen accumulation, as estimated by histological analysis of liver tissue stained with Sirius red. Grape skin and seeds also reduced hepatic stellate cell activation, as assessed by α-smooth muscle actin staining. In conclusion, grape skin and seeds exhibited in vivo hepatoprotective and antifibrogenic effects against DMN-induced liver injury, suggesting that grape skin and seeds may be useful in preventing the development of hepatic fibrosis. PMID:21103082

Thermal injury decreases hepatic blood flow and the intrinsic clearance of indocyanine green in the rat.

PubMed

Pollack, G M; Brouwer, K L

1991-01-01

The influence of severe thermal injury (full-thickness burns involving 50% of the body surface area) on hepatic blood flow in the rat was assessed using the tricarbocyanine dye indocyanine green (ICG). In a randomized crossover fashion, rats received sequential infusions of ICG through both the femoral vein and the portal vein, allowing the estimation of total hepatic plasma clearance and transhepatic extraction of the dye. These two parameters, along with the hematocrit, were used to calculate intrinsic hepatic clearance of ICG and hepatic blood flow. Animals were examined at 0 (control), 0.5, 12, or 24 hr following infliction of scald burns. Hepatic blood flow was decreased significantly by 0.5 hr postburn and remained approximately 20% below normal throughout the remainder of the study. The intrinsic efficiency of the liver in removing ICG from the systemic circulation was also decreased by thermal injury. The potential mechanisms involved in these two physiologic perturbations are discussed.

Modulatory role of kolaviron in phenytoin-induced hepatic and testicular dysfunctions in Wistar rats.

PubMed

Owoeye, Olatunde; Adedara, Isaac A; Adeyemo, Oluwatobi A; Bakare, Oluwafemi S; Egun, Christa; Farombi, Ebenezer O

2015-03-01

Phenytoin, an anticonvulsant agent used for the treatment of epilepsy has been reported to exhibit toxic side effects on the liver and testes. The present study investigated the protective effects of kolaviron (KV, a bioflavonoid from Garcinia kola seeds) against hepatic and testicular damage in rats exposed to phenytoin. The study consisted of four groups of six rats per group. Group I rats received 2 mL/kg of corn alone while group II received 75 mg/kg of phenytoin (PHT) alone. Groups III and IV were co-treated with kolaviron (200 mg/kg KV) and vitamin E (500 mg/kg VTE), respectively, for 14 days. The antioxidant status, hepatic and reproductive functional parameters were subsequently determined. PHT treatment significantly (p < 0.05) increased superoxide dismutase (SOD) and catalase (CAT) activities, elevated lipid peroxidation (LPO) and hydrogen peroxide (H2O2) levels along with significant reduction in the hepatic and testicular levels of glutathione (GSH). Moreover, PHT exposure elicited significant increases in alkaline phosphatase (ALP) and aspartate aminotransferase (AST) levels. The significant reduction in seminal epithelium thickness and the diameter of seminiferous tubules was accompanied with marked decrease in sperm motility, sperm count, and viability in PHT-treated rats. However, antioxidant status and the functional indices of liver and testes were restored to near control levels in rats co-treated with KV and VTE. In conclusion, KV and VTE protect the liver and testes against functional impairment due to PHT treatment.

Bamboo salt attenuates CCl4-induced hepatic damage in Sprague-Dawley rats

PubMed Central

Zhao, Xin; Song, Jia-Le; Kil, Jeung-Ha

2013-01-01

Bamboo salt, a Korean folk medicine, is prepared with solar salt (sea salt) and baked several times at high temperatures in a bamboo case. In this study, we compared the preventive effects of bamboo salt and purified and solar salts on hepatic damage induced by carbon tetrachloride in Sprague-Dawley rats. Compared with purified and solar salts, bamboo salts prevented hepatic damage in rats, as evidenced by significantly reduced serum levels of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase (P < 0.05). Bamboo salt (baked 9×) triggered the greatest reduction in these enzyme levels. In addition, it also reduced the levels of the proinflammatory cytokines interleukin (IL)-6, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. Histopathological sections of liver tissue demonstrated the protective effect of bamboo salt, whereas sections from animals treated with the other salt groups showed a greater degree of necrosis. We also performed reverse transcription-polymerase chain reaction and western blot analyses of the inflammation-related genes iNOS, COX-2, TNF-α, and IL-1β in rat liver tissues. Bamboo salt induced a significant decrease (~80%) in mRNA and protein expression levels of COX-2, iNOS, TNF-α, and IL-1β, compared with the other salts. Thus, we found that baked bamboo salt preparations could prevent CCl4-induced hepatic damage in vivo. PMID:23964314

Effects of high NaCl diet on arterial pressure in Sprague-Dawley rats with hepatic and sinoaortic denervation.

PubMed

Gao, Shuang; Tanaka, Kunihiko; Gotoh, Taro M; Morita, Hironobu

2005-08-01

The Na(+) receptor that exists in the hepatoportal region plays an important role in postprandial natriuresis and the regulation of Na(+) balance during NaCl load. Thus it would be considered that a dysfunction of the hepatic Na(+) receptor might result in the elevation of arterial pressure under a condition of high NaCl diet. To elucidate this hypothesis, arterial pressure was continuously measured during three weeks of high NaCl diet (8% NaCl) in four groups of rats: (i) intact rats, (ii) rats with hepatic denervation (HD), (iii) rats with sinoaortic denervation (SAD), and (iv) rats with SAD+HD. During a 1-week normal NaCl diet period, there was no difference in arterial pressure among the four groups. A high NaCl diet had no influence on arterial pressure in intact or HD rats; however, it significantly increased by 11 +/- 3 mmHg in SAD rats. The addition of HD to SAD had no synergistic effect on arterial pressure; i.e., in SAD+HD rats, mean arterial pressure increased by 13 +/- 1 mmHg. In conclusion, sinoaortic baroreceptor, but not hepatic Na(+) receptor, has a significant role in the long-term regulation of arterial pressure on a high NaCl diet.

Effects of Lactobacillus fermented soymilk and soy yogurt on hepatic lipid accumulation in rats fed a cholesterol-free diet.

PubMed

Kitawaki, Ryoko; Nishimura, Yuko; Takagi, Naohiro; Iwasaki, Mitsuhiro; Tsuzuki, Kimiko; Fukuda, Mitsuru

2009-07-01

We examined the effects of lactic acid fermented soymilk, in which part of the soymilk was replaced with okara (soy yogurt), on plasma and hepatic lipid profiles in rats fed a cholesterol-free diet. Additionally, we investigated the effects of soy yogurt on hepatic gene expression in rats using DNA microarray analysis. Male Sprague-Dawley rats aged 5 weeks (n=5/group) were fed a control diet (AIN-93) or a test diet in which 20% of the diet was replaced by soy yogurt for 7 weeks. Soy yogurt consumption did not affect body weight or adipose tissue weight as compared with control diet. In the soy yogurt group, the liver weight and hepatic triglyceride content were significantly lower than the control group, and the level of plasma cholesterol was also lower. Furthermore, DNA microarray analysis indicated that soy yogurt ingestion down-regulated the expression of the SREBP-1 gene and enzymes related to lipogenesis in the rat liver, while expression of beta-oxidation-related genes was up-regulated. These results suggest that soy yogurt is beneficial in preventing hepatic lipid accumulation in rats.

Expression of transmembrane 4 superfamily (TM4SF) proteins and their role in hepatic stellate cell motility and wound healing migration.

PubMed

Mazzocca, Antonio; Carloni, Vinicio; Sciammetta, Silvia; Cordella, Claudia; Pantaleo, Pietro; Caldini, Anna; Gentilini, Paolo; Pinzani, Massimo

2002-09-01

Migration of activated hepatic stellate cells (HSC) is a key event in the progression of liver fibrosis. Little is known about transmembrane proteins involved in HSC motility. Tetraspanins (TM4SF) have been implicated in cell development, differentiation, motility and tumor cell invasion. We evaluated the expression and function of four TM4SF, namely CD9, CD81, CD63 and CD151, and their involvement in HSC migration, adhesion, and proliferation. All TM4SF investigated were highly expressed at the human HSC surface with different patterns of intracellular distribution. Monoclonal antibodies directed against the four TM4SF inhibited HSC migration induced by extracellular matrix proteins in both wound healing and haptotaxis assays. This inhibition was independent of the ECM substrates employed (collagen type I or IV, laminin), and was comparable to that obtained by incubating the cells with an anti-beta1 blocking mAb. Importantly, cell adhesion was unaffected by the incubation with the same antibodies. Co-immunoprecipitation studies revealed different patterns of association between the four TM4SF studied and beta1 integrin. Finally, anti-TM4SF antibodies did not affect HSC growth. These findings provide the first characterization of tetraspanins expression and of their role in HSC migration, a key event in liver tissue wound healing and fibrogenesis.

High-fructose corn syrup-induced hepatic dysfunction in rats: improving effect of resveratrol.

PubMed

Sadi, Gokhan; Ergin, Volkan; Yilmaz, Guldal; Pektas, M Bilgehan; Yildirim, O Gokhan; Menevse, Adnan; Akar, Fatma

2015-09-01

The increased consumption of high-fructose corn syrup (HFCS) may contribute to the worldwide epidemic of fatty liver. In this study, we have investigated whether HFCS intake (20% beverages) influences lipid synthesis and accumulation in conjunction with insulin receptor substrate-1/2 (IRS-1; IRS-2), endothelial nitric oxide synthase (eNOS), sirtuin 1 (SIRT1) and inducible NOS (iNOS) expressions in liver of rats. Resveratrol was tested for its potential efficacy on changes induced by HFCS. Animals were randomly divided into four groups as control, resveratrol, HFCS and resveratrol plus HFCS (resveratrol + HFCS). HFCS was given as 20% solutions in drinking water. Feeding of all rats was maintained by a standard diet that enriched with or without resveratrol for 12 weeks. Dietary HFCS increased triglyceride content and caused mild microvesicular steatosis in association with up-regulation of fatty acid synthase and sterol regulatory element binding protein (SREBP)-1c in liver of rats. Moreover, HFCS feeding impaired hepatic expression levels of IRS-1, eNOS and SIRT1 mRNA/proteins, but did not change iNOS level. Resveratrol promoted IRS, eNOS and SIRT1, whereas suppressed SREBP-1c expression in rats fed with HFCS. Resveratrol supplementation considerably restored hepatic changes induced by HFCS. The improvement of hepatic insulin signaling and activation of SIRT1 by resveratrol may be associated with decreased triglyceride content and expression levels of the lipogenic genes of the liver.

Dietary Supplementation of Blueberry Juice Enhances Hepatic Expression of Metallothionein and Attenuates Liver Fibrosis in Rats

PubMed Central

Wang, Yuping; Cheng, Mingliang; Zhang, Baofang; Nie, Fei; Jiang, Hongmei

2013-01-01

Aim To investigate the effect of blueberry juice intake on rat liver fibrosis and its influence on hepatic antioxidant defense. Methods Rabbiteye blueberry was used to prepare fresh juice to feed rats by daily gastric gavage. Dan-shao-hua-xian capsule (DSHX) was used as a positive control for liver fibrosis protection. Liver fibrosis was induced in male Sprague-Dawley rats by subcutaneous injection of CCl4 and feeding a high-lipid/low-protein diet for 8 weeks. Hepatic fibrosis was evaluated by Masson staining. The expression of α-smooth muscle actin (α-SMA) and collagen III (Col III) were determined by immunohistochemical techniques. The activities of superoxide dismutase (SOD) and malondialdehyde (MDA) in liver homogenates were determined. Metallothionein (MT) expression was detected by real-time RT-PCR and immunohistochemical techniques. Results Blueberry juice consumption significantly attenuates CCl4-induced rat hepatic fibrosis, which was associated with elevated expression of metallothionein (MT), increased SOD activity, reduced oxidative stress, and decreased levels of α-SMA and Col III in the liver. Conclusion Our study suggests that dietary supplementation of blueberry juice can augment antioxidative capability of the liver presumably via stimulating MT expression and SOD activity, which in turn promotes HSC inactivation and thus decreases extracellular matrix collagen accumulation in the liver, and thereby alleviating hepatic fibrosis. PMID:23554912

Distribution of ciprofloxacin into the central nervous system in rats with acute renal or hepatic failure.

PubMed

Naora, K; Ichikawa, N; Hirano, H; Iwamoto, K

1999-05-01

Pharmacokinetic changes of various drugs have been reported in renal or hepatic failure. The present study employed ciprofloxacin, a quinolone antibiotic having neurotoxic side effects, to assess the influence of these diseases on distribution of ciprofloxacin into the central nervous system (CNS). After intravenous dosing of ciprofloxacin (10-30 mg kg(-1)), ciprofloxacin levels in plasma and brain were measured in normal rats (Wistar, male, 10-week-old) and those with acute renal and hepatic injuries which were induced by uranyl nitrate and carbon tetrachloride (CCl4), respectively. In the uranyl nitrate-treated rats, the plasma elimination half-life of ciprofloxacin was prolonged and the total body clearance was reduced when compared with those in the normal rats. Similar but smaller changes were observed in the CCl4-treated group. Brain levels of ciprofloxacin were significantly increased by both uranyl nitrate and CCl4 treatments. A proportional correlation between serum unbound levels and brain levels of ciprofloxacin was observed in the normal group. However, brain-to-serum unbound concentration ratios of ciprofloxacin were reduced in the rats with renal or hepatic failure. These results suggest that renal failure as well as hepatic failure retards elimination of ciprofloxacin from the blood, leading to elevation of the CNS level, and also that ciprofloxacin distribution in the brain is reduced in these disease states.

The soluble fiber complex PolyGlycopleX lowers serum triglycerides and reduces hepatic steatosis in high-sucrose-fed rats.

PubMed

Reimer, Raylene A; Grover, Gary J; Koetzner, Lee; Gahler, Roland J; Lyon, Michael R; Wood, Simon

2011-04-01

Viscous soluble fibers have been shown to reduce risk factors associated with type 2 diabetes and cardiovascular disease. The novel functional fiber, PolyGlycopleX (PGX) (InovoBiologic Inc, Calgary, Alberta, Canada) displays greater viscosity than other currently identified soluble fibers. The objective of this study was to determine if PGX lowers serum and hepatic triglycerides (TGs) in a high-sucrose-fed rat model. In this rodent model, feeding a high-sucrose diet consistently increases serum TGs. We hypothesized that consumption of PGX would attenuate hypertriglyceridemia and reduce hepatic steatosis compared with cellulose in rats fed a high-sucrose background diet. Male Sprague-Dawley rats were fed diets containing 65% sucrose and supplemented with either 5% cellulose (control) or 5% PGX (wt/wt) for 43 weeks. At study termination, serum insulin and TGs, hepatic steatosis, and hepatocellular injury were assessed. Body weight increased over time in both groups, but weight gain was attenuated in rats fed PGX vs cellulose in weeks 2 through 22 (P < .05). Serum TGs did not differ from baseline for the first half of the study but consistently increased in the cellulose group thereafter. PolyGlycopleX significantly reduced serum TG to near-baseline levels. At study termination, rats fed PGX had significantly lower hepatic steatosis scores (measured by Sudan black staining) compared with rats fed cellulose. Hepatocellular injury scores did not differ between the groups. In conclusion, PGX reduced serum TG and lipid accumulation in the liver of sucrose-fed rats. Further examination of its potential as a fiber supplement aimed at lessening the burden of hepatic steatosis is warranted. Copyright © 2011 Elsevier Inc. All rights reserved.

The effects of proton pump inhibitor on hepatic vascular responsiveness and hemodynamics in cirrhotic rats.

PubMed

Hsin, I-Fang; Hsu, Shao-Jung; Chuang, Chiao-Lin; Huo, Teh-Ia; Huang, Hui-Chun; Lee, Fa-Yauh; Ho, Hsin-Ling; Chang, Shu-Yu; Lee, Shou-Dong

2018-05-17

Liver cirrhosis is associated with increased intrahepatic resistance due to hepatic fibrosis and exaggerated vasoconstriction. Recent studies have indicated that proton pump inhibitors (PPIs), in addition to acid suppression, modulate vasoactive substances and vasoresponsiveness. PPIs are frequently prescribed in patients with cirrhosis due to a higher prevalence of peptic ulcers, however other impacts are unknown. Liver cirrhosis was induced in Sprague-Dawley rats with common bile duct ligation (BDL). On the 29th day after BDL and after hemodynamic measurements, the intrahepatic vascular responsiveness to high concentrations of endothelin-1 (ET-1) was evaluated after preincubation with (1) Krebs solution (vehicle), (2) esomeprazole (30 μM), or (3) esomeprazole plus N ω -nitro l-arginine (NNA, a non-selective NO synthase (NOS) inhibitor, 10 -4  M). After perfusion, the hepatic protein expressions of endothelial NOS (eNOS), inducible NOS (iNOS), cyclooxygenase (COX)-1, COX-2, endothelin-1, DDAH-1 (dimethylarginine dimethylaminohydrolase-1, ADMA inhibitor), DDAH-2, ADMA (asymmetrical dimethyl arginine, NOS inhibitor) were evaluated. In the chronic model, the BDL rats received (1) vehicle; or (2) esomeprazole (3.6 mg/kg/day, oral gavage) from the 1st to 28th day after BDL. On the 29th day and after hemodynamic measurements, plasma liver biochemistry and liver fibrosis were evaluated. Esomeprazole did not affect hepatic ET-1 vasoresponsiveness. The hepatic protein expressions of the aforementioned factors were not significantly different among the groups. There were no significant differences in hemodynamics, liver biochemistry and hepatic fibrosis after chronic esomeprazole administration. PPIs did not affect hepatic vasoresponsiveness or the release of vasoactive substances. Furthermore, they did not influence hemodynamics, liver biochemistry or severity of hepatic fibrosis in the cirrhotic rats. Copyright © 2018. Published by Elsevier Taiwan LLC.

TARGETED STELLATE DECENTRALIZATION: IMPLICATIONS FOR SYMPATHETIC CONTROL OF VENTRICULAR ELECTROPHYSIOLOGY

PubMed Central

Buckley, Una; Yamakawa, Kentaro; Takamiya, Tatsuo; Armour, J. Andrew; Shivkumar, Kalyanam; Ardell, Jeffrey L.

2015-01-01

Background Selective, bilateral cervicothoracic sympathectomy has proven to be effective for managing ventricular arrhythmias in the setting of structural heart disease. The procedure currently employed removes the caudal portions of both stellate ganglia, along with thoracic chain ganglia down to T4 ganglia. Objective To define the relative contributions of T1-T2 and the T3-T4 paravertebral ganglia in modulating ventricular electrical function. Methods In anesthetized vagotomised porcine subjects (n=8), the heart was exposed via sternotomy along with right and left paravertebral sympathetic ganglia to the T4 level. A 56-electrode epicardial sock was placed over both ventricles to assess epicardial activation recovery intervals (ARI) in response to individually stimulating right and left stellate vs T3 paravertebral ganglia. Responses to T3 stimuli were repeated following surgical removal of the caudal portions of stellate ganglia and T2 bilaterally. Results In intact preparations, stellate ganglion vs T3 stimuli (4Hz, 4ms duration) were titrated to produce equivalent decreases in global ventricular ARIs (right-side 85±6 vs 55±10 ms; left-side 24±3 vs 17±7 ms). Threshold of stimulus intensity applied to T3 ganglia to achieve threshold was 3 times that of T1 threshold. ARIs in unstimulated states were unaffected by bilateral stellate-T2 ganglion removal. Following acute decentralization, T3 stimulation failed to change ARIs. Conclusion Preganglionic sympathetic efferents arising from the T1-T4 spinal cord that project to the heart transit through stellate ganglia via the paravertebral chain. T1-T2 surgical excision is thus sufficient to functionally interrupt central control of peripheral sympathetic efferent activity. PMID:26282244

Exposure to a Northern Contaminant Mixture (NCM) Alters Hepatic Energy and Lipid Metabolism Exacerbating Hepatic Steatosis in Obese JCR Rats

PubMed Central

Mailloux, Ryan J.; Florian, Maria; Chen, Qixuan; Yan, Jin; Petrov, Ivan; Coughlan, Melanie C.; Laziyan, Mahemuti; Caldwell, Don; Lalande, Michelle; Patry, Dominique; Gagnon, Claude; Sarafin, Kurtis; Truong, Jocelyn; Chan, Hing Man; Ratnayake, Nimal; Li, Nanqin; Willmore, William G.; Jin, Xiaolei

2014-01-01

Non-alcoholic fatty liver disease (NAFLD), defined by the American Liver Society as the buildup of extra fat in liver cells that is not caused by alcohol, is the most common liver disease in North America. Obesity and type 2 diabetes are viewed as the major causes of NAFLD. Environmental contaminants have also been implicated in the development of NAFLD. Northern populations are exposed to a myriad of persistent organic pollutants including polychlorinated biphenyls, organochlorine pesticides, flame retardants, and toxic metals, while also affected by higher rates of obesity and alcohol abuse compared to the rest of Canada. In this study, we examined the impact of a mixture of 22 contaminants detected in Inuit blood on the development and progression of NAFLD in obese JCR rats with or without co-exposure to10% ethanol. Hepatosteatosis was found in obese rat liver, which was worsened by exposure to 10% ethanol. NCM treatment increased the number of macrovesicular lipid droplets, total lipid contents, portion of mono- and polyunsaturated fatty acids in the liver. This was complemented by an increase in hepatic total cholesterol and cholesterol ester levels which was associated with changes in the expression of genes and proteins involved in lipid metabolism and transport. In addition, NCM treatment increased cytochrome P450 2E1 protein expression and decreased ubiquinone pool, and mitochondrial ATP synthase subunit ATP5A and Complex IV activity. Despite the changes in mitochondrial physiology, hepatic ATP levels were maintained high in NCM-treated versus control rats. This was due to a decrease in ATP utilization and an increase in creatine kinase activity. Collectively, our results suggest that NCM treatment decreases hepatic cholesterol export, possibly also increases cholesterol uptake from circulation, and promotes lipid accumulation and alters ATP homeostasis which exacerbates the existing hepatic steatosis in genetically obese JCR rats with or without co

Methylation of Septin9 mediated by DNMT3a enhances hepatic stellate cells activation and liver fibrogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Yuting, E-mail: wuyuting1302@sina.com; Bu, Fan

Liver fibrosis, resulting from chronic and persistent injury to the liver, is a worldwide health problem. Advanced liver fibrosis results in cirrhosis, liver failure and even hepatocellular cancer (HCC), often eventually requiring liver transplantation, poses a huge health burden on the global community. However, the specific pathogenesis of liver fibrosis remains not fully understood. Numerous basic and clinical studies have provided evidence that epigenetic modifications, especially DNA methylation, might contribute to the activation of hepatic stellate cells (HSCs), the pivotal cell type responsible for the fibrous scar in liver. Here, reduced representation bisulfite sequencing (RRBS) and bisulfite pyrosequencing PCR (BSP)more » analysis identified hypermethylation status of Septin9 (Sept9) gene in liver fibrogenesis. Sept9 protein was dramatically decreased in livers of CCl4-treated mice and immortalized HSC-T6 cells exposed to TGF-β1. Nevertheless, the suppression of Sept9 could be blocked by DNMT3a-siRNA and DNA methyltransferase inhibitor, 5-aza-2′-deoxycytidine (5-azadC). Overexpressed Sept9 attenuated TGF-β1-induced expression of myofibroblast markers α-SMA and Col1a1, accompanied by up-regulation of cell apoptosis-related proteins. Conversely, RNAi-mediated silencing of Sept9 enhanced accumulation of extracellular matrix. These observations suggested that Sept9 contributed to alleviate liver fibrosis might partially through promoting activated HSCs apoptosis and this anti-fibrogenesis effect might be blocked by DNMT-3a mediated methylation of Sept9. Therefore, pharmacological agents that inhibit Sept9 methylation and increase its expression could be considered as valuable treatments for liver fibrosis. - Highlights: • This is the first report of Sept9 methylation and function in liver fibrosis. • Ectopic expression of Sept9 could block the liver fibrogenesis. • DNMT3a might be responsible for the suppression of Sept9 in liver fibrosis.« less

Rats fed fructose-enriched diets have characteristics of nonalcoholic hepatic steatosis.

PubMed

Kawasaki, Takahiro; Igarashi, Kanji; Koeda, Tatsuki; Sugimoto, Keiichiro; Nakagawa, Kazuya; Hayashi, Shuichi; Yamaji, Ryoichi; Inui, Hiroshi; Fukusato, Toshio; Yamanouchi, Toshikazu

2009-11-01

Nonalcoholic steatohepatitis (NASH) and nonalcoholic fatty liver disease are increasing in adults and are likely to be increasing in children. Both conditions are hepatic manifestations of metabolic syndrome. Experimental animals fed fructose-enriched diets are widely recognized as good models for metabolic syndrome. However, few reports have described the hepatic pathology of these experimental animals. In this study, 5-wk-old Wistar specific pathogen-free rats, which are a normal strain, were fed experimental diets for 5 wk. We then evaluated the degree of steatohepatitis. The 5 diet groups were as follows: cornstarch (70% wt:wt) [control (C)], high-fructose (70%) (HFr), high-sucrose (70%) (HS), high-fat (15%) (HF), and high-fat (15%) high-fructose (50%) (HFHFr) diets. The macrovesicular steatosis grade, liver:body weight ratio, and hepatic triglyceride concentration were significantly higher in the HFr group than in the other 4 groups. However, the HFr group had a significantly lower ratio of epididymal white fat:body weight than the other 4 groups and had a lower final body weight than the HF and HFHFr groups. The HF group had a greater final body weight than the C, HFr, and HS groups, but no macrovesicular steatosis was observed. The HFr group had a significantly higher grade of lobular inflammation than the other 4 groups. The distribution of lobular inflammation was predominant over portal inflammation, which is consistent with human NASH. In conclusion, rats fed fructose-enriched diets are a better model for NASH than rats fed fat-enriched diets.

Pregnancy and maternal iron deficiency stimulate hepatic CRBPII expression in rats.

PubMed

Cottin, Sarah C; Gambling, Lorraine; Hayes, Helen E; Stevens, Valerie J; McArdle, Harry J

2016-06-01

Iron deficiency impairs vitamin A (VA) metabolism in the rat but the mechanisms involved are unknown and the effect during development has not been investigated. We investigated the effect of pregnancy and maternal iron deficiency on VA metabolism in the mother and fetus. 54 rats were fed either a control or iron deficient diet for 2weeks prior to mating and throughout pregnancy. Another 15 female rats followed the same diet and were used as non-pregnant controls. Maternal liver, placenta and fetal liver were collected at d21 for total VA, retinol and retinyl ester (RE) measurement and VA metabolic gene expression analysis. Iron deficiency increased maternal hepatic RE (P<.05) and total VA (P<.0001), fetal liver RE (P<.05), and decreased placenta total VA (P<.05). Pregnancy increased Cellular Retinol Binding Protein (CRBP)-II gene expression by 7 fold (P=.001), decreased VA levels (P=.0004) and VA metabolic gene expression (P<.0001) in the liver. Iron deficiency increased hepatic CRBPII expression by a further 2 fold (P=.044) and RBP4 by~20% (P=.005), increased RBPR2 and decreased CRBPII, LRAT, and TTR in fetal liver, while it had no effect on VA metabolic gene expression in the placenta. Hepatic CRBPII expression is increased by pregnancy and further increased by iron deficiency, which may play an important role in VA metabolism and homeostasis. Maternal iron deficiency also alters VA metabolism in the fetus, which is likely to have consequences for development. Copyright © 2016 Elsevier Inc. All rights reserved.

Intake of phytic acid and myo-inositol lowers hepatic lipogenic gene expression and modulates gut microbiota in rats fed a high-sucrose diet.

PubMed

Okazaki, Yukako; Sekita, Ayaka; Katayama, Tetsuyuki

2018-05-01

Dietary phytic acid (PA) was recently reported by our group to suppress hepatic lipogenic gene expression and modulate gut microbiota in rats fed a high-sucrose (HSC) diet. The present study aimed to investigate whether the modulatory effects of PA depend on the dietary carbohydrate source and are attributed to the myo-inositol (MI) ring of PA. Male Sprague-Dawley rats were fed an HSC or a high-starch (HSR) diet with or without 1.02% sodium PA for 12 days. Subsequently, the rats were fed the HSC diet, the HSC diet containing 1.02% sodium PA or an HSC diet containing 0.2% MI for 12 days. The HSC diet significantly increased the hepatic triglyceride (TG) concentration as well as the activity and expression of hepatic lipogenic enzymes compared with the HSR diet. The increases were generally suppressed by dietary PA with a concomitant increase in the fecal and cecal ratios of Lactobacillus spp. In rats fed the HSR diet, PA intake did not substantially affect the factors associated with hepatic lipid metabolism or gut microbiota composition. The effects of MI intake were similar to that of PA intake on hepatic lipogenesis and gut microbiota in rats fed the HSC diet. These results suggest that dietary PA downregulates hepatic lipogenic gene expression and modulates gut microbiota composition in rats fed an HSC diet but not in rats fed an HSR diet. The MI ring of PA may be responsible for the effects of PA intake on hepatic lipogenic gene expression and gut microbiota.

Hepatoprotective Effects of Grape Seed Procyanidin B2 in Rats With Carbon Tetrachloride-induced Hepatic Fibrosis.

PubMed

Wang, Zhenli; Zhang, Zemin; Du, Ning; Wang, Kai; Li, Lei

2015-01-01

Infectious hepatitis is a serious problem affecting millions of people worldwide, particularly in China and other developing countries, and it is the major risk factor for hepatic cirrhosis. To date, the pathogenesis of hepatic cirrhosis is complex and unclear. Traditional Chinese medicine (TCM) has long been used in its treatment; however, little is known to date about the effects of grape seed procyanidin B2 (GSPB2) on liver fibrosis. Using a rat model of carbon tetrachloride (CCl4)-induced hepatic fibrosis, the study intended to investigate the hepatoprotective effects of GSPB2 and to determine the possible pathway by which GSPB2 exerts its activities. Design • Thirty-six male, Sprague-Dawley rats were used in the study. Rats in a model (CCl4 only) group and the GSPB2 group were given CCl4 to induce hepatic fibrosis. Simultaneously, animals in the GSPB2 group were treated with GSPB2 by intragastric administration for 12 wk. In addition, the rat's Kupffer cells were cultured with CCl4 and GSPB2. The study took place at the central laboratory of Qilu Hospital at Shandong University in Jinan, China. The following parameters were investigated: (1) hepatic function; (2) the liver fibrosis index-serum hyaluronic acid (HA), laminin (LN), type 3 procollagen (PC-3), collagen 4, and hepatic hydroxyproline; (3) the expression in the liver of transforming growth factor β-1 (TGF-β1); (4) inflammatory cytokines in the liver and cell culture medium-tumor necrosis factor α (TNF-α), interleukin (IL) 1-β (IL-1β), IL-6, and IL-17; (5) oxidative stress markers in the liver and cell culture medium-malondialdehyde (MDA), 8-hydroxy-2-deoxyguanosine (8-OHdG), total superoxide dismutase (T-SOD), and total antioxidant capacity (T-AOC); and (6) levels of angiotensin 2 (Ang 2) in the liver. The CCl4 induced (1) significant hepatic-function damage; (2) elevated levels of the measures of the liver fibrosis index, TGF-β1, inflammatory cytokines, MDA, and 8-OHdG; (3) a reduction in

Saccharomyces boulardii ameliorates clarithromycin- and methotrexate-induced intestinal and hepatic injury in rats.

PubMed

Duman, Deniz Güney; Kumral, Zarife Nigâr Özdemir; Ercan, Feriha; Deniz, Mustafa; Can, Güray; Cağlayan Yeğen, Berrak

2013-08-28

Saccharomyces boulardii is a probiotic used for the prevention of antibiotic-associated diarrhoea. We aimed to investigate whether S. boulardii could alter the effects of clarithromycin (CLA) and methotrexate (MTX) on oro-caecal intestinal transit and oxidative damage in rats. Rats were divided into two groups receiving a single dose of MTX (20 mg/kg) or CLA (20 mg/kg per d) for 1 week. Groups were treated with either saline or S. boulardii (500 mg/kg) twice per d throughout the experiment. The control group was administered only saline. Following decapitation, intestinal transit and inflammation markers of glutathione (GSH), malondialdehyde and myeloperoxidase were measured in intestinal and hepatic tissues. CLA and MTX increased intestinal transit, while S. boulardii treatment slowed down CLA-facilitated transit back to control level. Both MTX and CLA increased lipid peroxidation while depleting the antioxidant GSH content in the hepatic and ileal tissues. Conversely, lipid peroxidation was depressed and GSH levels were increased in the ileal and hepatic tissues of S. boulardii-treated rats. Increased ileal neutrophil infiltration due to MTX and CLA treatments was also reduced by S. boulardii treatment. Histological analysis supported that S. boulardii protected intestinal tissues against the inflammatory effects of both agents. These findings suggest that S. boulardii ameliorates intestinal injury and the accompanying hepatic inflammation by supporting the antioxidant state of the tissues and by inhibiting the recruitment of neutrophils. Moreover, a preventive effect on MTXinduced toxicity is a novel finding of S. boulardii, proposing it as an adjunct to chemotherapy regimens.

Comparative pharmacokinetics and tissue distribution profiles of lignan components in normal and hepatic fibrosis rats after oral administration of Fuzheng Huayu recipe.

PubMed

Yang, Tao; Liu, Shan; Zheng, Tian-Hui; Tao, Yan-Yan; Liu, Cheng-Hai

2015-05-26

Fuzheng Huayu recipe (FZHY) is formulated on the basis of Chinese medicine theory in treating liver fibrosis. To illuminate the influence of the pathological state of liver fibrosis on the pharmacokinetics and tissue distribution profiles of lignan components from FZHY. Male Wistar rats were randomly divided into normal group and Hepatic fibrosis group (induced by dimethylnitrosamine). Six lignan components were detected and quantified by ultrahigh performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in the plasma and tissue of normal and hepatic fibrosis rats. A rapid, sensitive and convenient UHPLC-MS/MS method has been developed for the simultaneous determination of six lignan components in different rat biological samples successfully. After oral administration of FZHY at a dose of 15g/kg, the pharmacokinetic behaviors of schizandrin A (SIA), schizandrin B (SIB), schizandrin C (SIC), schisandrol A (SOA), Schisandrol B (SOB) and schisantherin A (STA) have been significantly changed in hepatic fibrosis rats compared with the normal rats, and their AUC(0-t) values were increased by 235.09%, 388.44%, 223.30%, 669.30%, 295.08% and 267.63% orderly (P<0.05). Tissue distribution results showed the amount of SIA, SIB, SOA and SOB were significant increased in heart, lung, spleen and kidney of hepatic fibrosis rats compared with normal rats at most of the time point (P<0.05). Meanwhile, the result also reveals that the hepatic fibrosis could delay the peak time of lignans in liver. The results proved that the established UHPLC-MS/MS method could be applied to the comparative study on pharmacokinetics and tissue distribution of lignan components in normal and hepatic fibrosis rats. The hepatic fibrosis could alter the pharmacokinetics and tissue distribution properties of lignan components in rats after administration of FZHY. The results might be helpful for guide the clinical application of this medicine. Copyright © 2015 Elsevier Ireland Ltd. All

Effects of gamma-irradiated fats on plasma lipid concentrations and hepatic cholesterol metabolism in rats.

PubMed

Kim, E; Jeon, S M; Choi, M S

2001-01-01

Currently, there is a growing need for food irradiation that is effective in food preservation and quality improvement. Accordingly, this study was designed to observe the effects of gamma-irradiated dietary fat on plasma lipid concentrations and hepatic cholesterol metabolism in rats. Male rats were fed 5-kGy-gamma-irradiated beef tallow (gammaBT), corn oil (gammaCO), perilla oil (gammaPO), and nonirradiated fats (BT, CO, and PO) for 6 weeks. The gamma-irradiated fat feeding did not affect the plasma lipid concentrations. However, the hepatic cholesterol content was significantly higher in the rats fed gamma-CO as compared with the rats fed nonirradiated CO (40.0 vs. 28.2 mg/g liver). The hepatic HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase activities were not significantly different between the controls and the gamma-irradiated fat fed groups. However, the hepatic ACAT (acyl-CoA:cholesterol acyltransferase) activity was significantly lower in the gammaPO group as compared with its control group (138.2 vs. 404.5 pmol min(-1) mg(-1)). Among the nonirradiated groups, the ACAT activities of the CO and PO groups were higher than that of the BT group. The amounts of coprostanone, cholesterol, and total fecal neutral sterol were significantly higher in the gammaPO group as compared with the other groups. These results indicate that although slight changes in the lipid metabolism were observed as a result of 5-kGy-gamma-irradiated fat feeding, they were relative to the fat type and had no harmful consequences. Copyright 2001 S. Karger AG, Basel

[Influence of bear bile on rat hepatocarcinoma induced by diethylnitrosamine].

PubMed

Zhou, Jian-Yin; Yin, Zhen-Yu; Wang, Sheng-Yu; Yan, Jiang-Hua; Zhao, Yi-Lin; Wu, Duan; Liu, Zheng-Jin; Zhang, Sheng; Wang, Xiao-Min

2012-11-01

To investigate the influence of bear bile on rat hepatocarcinoma induced by diethylnitrosamine (DEN), a total of 40 rats were randomly divided into 4 groups: normal control group, model group, and two bear bile treatment groups. The rat liver cancer model was induced by breeding with water containing 100 mg x L(-1) DEN for 14 weeks. The rats of the bear bile groups received bear bile powder (200 or 400 mg x kg(-1)) orally 5 times per week for 18 weeks. The general condition and the body weight of rats were examined every day. After 18 weeks the activities of serum alanine transaminase (ALT), aspartate transaminase (AST) and total bilirubin (TBIL) were detected. Meanwhile, the pathological changes of liver tissues were observed after H&E staining. The expression of proliferative cell nuclear antigen (PCNA) and a-smooth muscle actin (alpha-SMA) in liver tissue were detected by immunohistochemical method. After 4 weeks the body weights of rats in normal group were significantly more than that in other groups (P < 0.05); and that in the two bile groups was significantly more than that in the model group. Compared with normal group, the level of serum glutamic-pyruvic transaminase and total bilirubin increased significantly in other groups; compared with model group, these two indexes decreased significantly in two bile groups. Hepatocellular carcinoma occurred in all rats except for normal group; there were classic cirrhosis and cancer in model group while there were mild cirrhosis and high differentiation in two bile groups. There were almost no expressions of PCNA and alpha-SMA in normal group while there were high expressions in model group; the two bile groups had some expressions but were inferior to the model group, and alpha-SMA reduced markedly. It indicated that bear bile restrained the development of liver cancer during DEN inducing rat hepatocarcinoma, which may be related to its depressing hepatic stellate cell activation and relieving hepatic lesion and

Effect of Rifaximin on Hepatic Fibrosis in Bile Duct-ligated Rat Model.

PubMed

Shin, Seung Kak; Kwon, Oh Sang; Lee, Jong Joon; Park, Yeon Ho; Choi, Cheol Soo; Jeong, Sung Hwan; Choi, Duck Joo; Kim, Yun Soo; Kim, Ju Hyun

2017-11-25

The translocation of bacteria and their lipopolysaccharides from the gut can promote fibrosis in cirrhotic patients. The aim of this study was to investigate the effects of rifaximin on hepatic fibrosis in a bile duct-ligated rat model. The bile duct ligation (BDL) was carried out for eight days (acute injury model: sham-operated rats [G1], BDL rats [G2], and BDL rats treated with rifaximin [G3]) or 22 days (chronic injury model: sham-operated rats [G4], BDL rats [G5], and BDL rats treated with rifaximin [G6]). Rifaximin (50 mg/kg/day) was administered daily via gavage after BDL. Liver function, serum tumor necrosis factor-alpha (TNF-α), and hepatic hydroxyproline levels were measured. Moreover, a histological analysis of fibrosis contents was performed using sirius red stain. In the acute injury model, the liver function and TNF-α level were not improved after the rifaximin treatment. The hydroxyproline levels (µg/g liver tissue) in G1, G2, and G3 were 236.4±103.1, 444.8±114.4, and 312.5±131.6, respectively; and fibrosis contents (%) were 0.22±0.04, 1.64±0.53, and 1.66±0.44, respectively. The rifaximin treatment did not ameliorate acute BDL-induced fibrosis. In the chronic injury model, the hydroxyproline levels in G4, G5, and G6 were 311.5±72.9, 1,110.3±357.9, and 944.3±209.3, respectively; and fibrosis contents (%) were 0.19±0.03, 5.04±0.18, and 4.42±0.68, respectively (G5 vs. G6, p=0.059). The rifaximin treatment marginally ameliorated chronic BDL-induced fibrosis. Rifaximin did not reduce inflammation and fibrosis in bile duct-ligated rat model.

Vitis vinifera Extract Ameliorate Hepatic and Renal Dysfunction Induced by Dexamethasone in Albino Rats

PubMed Central

Hasona, Nabil A.; Alrashidi, Ahmed A.; Aldugieman, Thamer Z.; Alshdokhi, Ali M.; Ahmed, Mohammed Q.

2017-01-01

This study was conducted to evaluate the biochemical effects of grape seed extract against dexamethasone-induced hepatic and renal dysfunction in a female albino rat. Twenty-eight adult female rats were divided randomly into four equal groups: Group 1: animals were injected subcutaneously with saline and consider as normal control one. Group 2: animals were injected subcutaneously with dexamethasone in a dose of 0.1 mg/kg body weight. Group 3: animals were injected subcutaneously with 0.1 mg/kg body weight of dexamethasone, and then treated with a grape seed extract in a dose of 200 mg/kg body weight by oral gavage. Group 4: animals were injected subcutaneously with 0.1 mg/kg body weight of dexamethasone, and then treated with a grape seed extract in a dose of 400 mg/kg body weight by oral gavage. After 4 weeks, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) activities, albumin, uric acid, creatinine, and glucose levels were assayed. Hepatic reduced glutathione (GSH), total protein content, and catalase and glucose-6-phosphate dehydrogenase activities were also assayed. Dexamethasone administration caused elevation of serum levels of glucose, uric acid, creatinine, ALT, AST activities, and a decrease in other parameters such as hepatic glutathione, total protein levels, and catalase enzyme activity. Treatment with Vitis vinifera L. seed extract showed a significant increase in the body weight of rats in the group treated with Vitis vinifera L. seed extract orally compared with the dexamethasone control group. An increase in GSH and catalase activity in response to oral treatment with Vitis vinifera L. seed extract was observed after treatment. Grape seed extract positively affects glucocorticoid-induced hepatic and renal alteration in albino rats. PMID:29051443

Characterization of murine hepatitis virus (JHM) RNA from rats with experimental encephalomyelitis.

PubMed

Jackson, D P; Percy, D H; Morris, V L

1984-09-01

When Wistar Furth rats are inoculated intracerebrally with the murine hepatitis virus JHM they often develop a demyelinating disease with resulting hind leg paralysis. Using an RNA transfer procedure and hybridization kinetic analysis, the virus-specific RNA in these rats was characterized. The pattern of JHM-specific RNA varied with individual infections of Wistar Furth rats. However, two species of JHM-specific RNA, the nucleocapsid and a 2.1-2.4 X 10(6)-Da RNA species were generally present. A general decrease in JHM-specific RNA in brains and spinal cord samples taken later than 20 days postinoculation was observed; however, JHM-specific RNA persisted in the spinal cord longer than in the brain of these rats.

Influence of Moxifloxacin on Hepatic Redox Status and Plasma Biomarkers of Hepatotoxicity and Nephrotoxicity in Rat

PubMed Central

Olayinka, Ebenezer Tunde

2015-01-01

Moxifloxacin is a broad spectrum fluoroquinolone antibacterial agent. We examined the hepatic redox status and plasma biomarkers of nephrotoxicity and hepatotoxicity in rat following administration of moxifloxacin (MXF). Twenty-four Wistar rats, 180–200 g, were randomized into four groups (I–IV). Animals in group I (control) received 1 mL of distilled water, while animals in groups II, III, and IV received 1 mL each of MXF equivalent to 4 mg/kg b.w., 8 mg/kg b.w., and 16 mg/kg b.w., respectively. After seven days, plasma urea, bilirubin, and creatinine were significantly (P < 0.05) elevated in the MXF-treated animals. Activities of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase were significantly increased in the plasma of MXF-treated animals compared to control. Also plasma total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides increased significantly in the MXF-treated groups relative to control. Moreover, MXF triggered a significant decrease in hepatic catalase, superoxide dismutase, and glutathione-S transferase activities. Likewise, MXF caused a decrease in the hepatic levels of glutathione and vitamin C. A significant increase in hepatic MDA content was also observed in the MXF-treated animals relative to control. Overall, our data suggest that the half-therapeutic, therapeutic, and twice the therapeutic dose of MXF induced nephrotoxicity, hepatotoxicity, and altered hepatic redox balance in rats. PMID:26550491

Hepatic differentiation capability of rat bone marrow-derived mesenchymal stem cells and hematopoietic stem cells.

PubMed

Shu, Sai-Nan; Wei, Lai; Wang, Jiang-Hua; Zhan, Yu-Tao; Chen, Hong-Song; Wang, Yu

2004-10-01

To investigate the different effects of mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) on hepatic differentiation. MSCs from rat bone marrow were isolated and cultured by standard methods. HSCs from rat bone marrow were isolated and purified by magnetic activated cell sorting. Both cell subsets were induced. Morphology, RT-PCR and immunocytochemistry were used to identify the hepatic differentiation grade. MSCs exhibited round in shape after differentiation, instead of fibroblast-like morphology before differentiation. Albumin mRNA and protein were expressed positively in MSCs, without detection of alpha-fetoprotein (AFP). HSCs were polygonal in shape after differentiation. The expression of albumin signal decreased and AFP signal increased. The expression of CK18 was continuous in MSCs and HSCs both before and after induction. Both MSCs and HSCs have hepatic differentiation capabilities. However, their capabilities are not the same. MSCs can differentiate into mature hepatocyte-like cells, never expressing early hepatic specific genes, while Thy-1.1(+) cells are inclined to differentiate into hepatic stem cell-like cells, with an increasing AFP expression and a decreasing albumin signal. CK18 mRNA is positive in Thy-1.1(+) cells and MSCs, negative in Thy-1.1(-) cells. It seems that CK18 has some relationship with Thy-1.1 antigen, and CK18 may be a predictive marker of hepatic differentiation capability.

Lung Matrix Metalloproteinase Activation following Partial Hepatic Ischemia/Reperfusion Injury in Rats

PubMed Central

Ferrigno, Andrea; Rizzo, Vittoria; Tarantola, Eleonora

2014-01-01

Purpose. Warm hepatic ischemia-reperfusion (I/R) injury can lead to multiorgan dysfunction. The aim of the present study was to investigate whether acute liver I/R does affect the function and/or structure of remote organs such as lung, kidney, and heart via modulation of extracellular matrix remodelling. Methods. Male Sprague-Dawley rats were subjected to 30 min partial hepatic ischemia by clamping the hepatic artery and the portal vein. After a 60 min reperfusion, liver, lung, kidney, and heart biopsies and blood samples were collected. Serum hepatic enzymes, creatinine, urea, Troponin I and TNF-alpha, and tissue matrix metalloproteinases (MMP-2, MMP-9), myeloperoxidase (MPO), malondialdehyde (MDA), and morphology were monitored. Results. Serum levels of hepatic enzymes and TNF-alpha were concomitantly increased during hepatic I/R. An increase in hepatic MMP-2 and MMP-9 activities was substantiated by tissue morphology alterations. Notably, acute hepatic I/R affect the lung inasmuch as MMP-9 activity and MPO levels were increased. No difference in MMPs and MPO was observed in kidney and heart. Conclusions. Although the underlying mechanism needs further investigation, this is the first study in which the MMP activation in a distant organ is reported; this event is probably TNF-alpha-mediated and the lung appears as the first remote organ to be involved in hepatic I/R injury. PMID:24592193

Hepatoprotective activity of Tridax procumbens against d-galactosamine/lipopolysaccharide-induced hepatitis in rats.

PubMed

Ravikumar, Vilwanathan; Shivashangari, Kanchi Subramanian; Devaki, Thiruvengadam

2005-10-03

The hepatoprotective activity of aerial parts of Tridax procumbens was investigated against d-Galactosamine/Lipopolysaccharide (d-GalN/LPS) induced hepatitis in rats. d-GalN/LPS (300 mg/kg body weight/30 microg/kg body weight)-induced hepatic damage was manifested by a significant increase in the activities of marker enzymes (aspartate transaminase, alanine transaminase, alkaline phosphatase, lactate dehydrogenase and gamma glutamyl transferase) and bilirubin level in serum and lipids both in serum and liver. Pretreatment of rats with a chloroform insoluble fraction from ethanolic extract of Tridax procumbens reversed these altered parameters to normal values. The biochemical observations were supplemented by histopathological examination of liver sections. Results of this study revealed that Tridax procumbens could afford a significant protection in the alleviation of d-GalN/LPS-induced hepatocellular injury.

Phosphorylation of the rat hepatic polymeric IgA receptor.

PubMed Central

Larkin, J M; Sztul, E S; Palade, G E

1986-01-01

In vivo labeling with [35S]cysteine has identified three transmembrane forms of the rat hepatic polymeric IgA receptor: (i) a 105-kDa core glycosylated precursor; (ii) a terminally glycosylated 116-kDa intermediate; and (iii) a mature 120-kDa form. In the current study we show that the 120-kDa form is phosphorylated. After in vivo labeling with [32P]orthophosphate, all receptor forms were immunoprecipitated from hepatic total microsomes (TM) (with an antireceptor antiserum), separated by NaDodSO4/PAGE, and detected by autoradiography. The 120-kDa form was selectively phosphorylated, whereas the 116- and 105-kDa forms incorporated no detectable 32P. To determine the topology of the phosphorylation sites, hepatic TM isolated from rats labeled in vivo with either [35S]cysteine or [32P]orthophosphate were treated with trypsin. TM were solubilized and receptors were immunoprecipitated from lysates. With increasing trypsin concentrations, the [35S]cysteine-labeled receptor triplet was degraded to a trypsin-resistant doublet of approximately 95 and 85 kDa, indicating that approximately 20 kDa was removed from the receptor endodomain by trypsin. The same treatment removed all detectable 32P from labeled receptors. Furthermore, no 32P was detected in the 80-kDa biliary form of the receptor. Serine was identified as the only phosphorylated residue in acid hydrolysates of 32P-labeled immunoprecipitated receptor. These findings indicate that (i) the 120-kDa form is the only phosphorylated species of the receptor; and (ii) the phosphorylated residues are serine(s) located in the endodomain of the protein. Images PMID:3460069

Experimental non-alcoholic fatty liver disease results in decreased hepatic uptake transporter expression and function in rats

PubMed Central

Fisher, Craig D.; Lickteig, Andrew J.; Augustine, Lisa M.; Oude Elferink, Ronald P.J.; Besselsen, David G.; Erickson, Robert P.; Cherrington, Nathan J.

2009-01-01

Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of diagnoses ranging from simple fatty liver (SFL), to non-alcoholic steatohepatitis (NASH). This study aimed to determine the effect of moderate and severe NAFLD on hepatic transporter expression and function in vivo. Rats were fed a high-fat diet (SFL model) or a methionine-choline-deficient diet (NASH model) for eight weeks. Hepatic uptake transporter function was determined by bromosulfophthalein (BSP) disposition. Transporter expression was determined by branched DNA signal amplification assay and western blotting; inflammation was identified by immunostaining of liver slices for interleukin 1 beta (IL-1β). MC- rats showed significant retention of BSP in the plasma when compared to control rats. Hepatic NTCP, OATP1a1, 1a4, 1b2 and 2b1; and OAT 2 and 3 mRNA levels were significantly decreased in high-fat and MC- diet rats when compared to control. Protein expression of OATP1a1 was significantly decreased in high-fat animals, while OATP1a1 and OATP1b2 expression was significantly lower in MC- rats when compared to control. Liver tissue from high-fat and MC- rats stained positive for IL-1β, a pro-inflammatory cytokine known to decrease expression of NTCP, OATP and OAT transporters, suggesting a plausible mechanism for the observed transporter alterations. These data suggest that different stages of NAFLD result in altered hepatic uptake transporter expression that can lead to a functional impairment of xenobiotic uptake from the blood. Furthermore, NAFLD may alter the plasma retention time of clinically relevant drugs that are reliant on these transporters and may increase the potential drug toxicity. PMID:19358839

Vitamin A status affects obesity development and hepatic expression of key genes for fuel metabolism in Zucker fatty rats.

PubMed

Zhang, Yan; Li, Rui; Li, Yang; Chen, Wei; Zhao, Shi; Chen, Guoxun

2012-08-01

We hypothesized that vitamin A (VA) status may affect obesity development. Male Zucker lean (ZL) and fatty (ZF) rats after weaning were fed a synthetic VA deficient (VAD) or VA sufficient (VAS) diet for 8 weeks before their plasma parameters and hepatic genes' expression were analyzed. The body mass (BM) of ZL or ZF rats fed the VAD diet was lower than that of their corresponding controls fed the VAS diet at 5 or 2 weeks, respectively. The VAD ZL and ZF rats had less food intake than the VAS rats after 5 weeks. The VAD ZL and ZF rats had lower plasma glucose, triglyceride, insulin, and leptin levels, as well as lower liver glycogen content, net mass of epididymal fat, and liver/BM and epididymal fat/BM ratios (ZL only) than their respective VAS controls. VAD rats had lower hepatic Cyp26a1, Srebp-1c, Fas, Scd1, Me1, Gck, and Pklr (ZL and ZF); and higher Igfbp1 (ZL and ZF), Pck1(ZF only), and G6pc (ZF only) mRNA levels than their respective VAS controls. We conclude that ZL and ZF rats responded differently to dietary VA deficiency. VA status affected obesity development and altered the expression of hepatic genes for fuel metabolism in ZF rats. The mechanisms will help us to combat metabolic diseases.

Impairment of GH/IGF-1 Axis in the Liver of Patients with HCV-Related Chronic Hepatitis.

PubMed

Carotti, Simone; Guarino, Michele Pier Luca; Valentini, Francesco; Porzio, Silvio; Vespasiani-Gentilucci, Umberto; Perrone, Giuseppe; Zingariello, Maria; Gallo, Paolo; Cicala, Michele; Picardi, Antonio; Morini, Sergio

2018-02-01

Resistance to the action of growth hormone (GH) frequently complicates liver cirrhosis, while, physiologically, the activation of GH receptor (GHR) determines phosphorylation of signal transducer and activator of transcription (STAT)-5 and the consequent induction of insulin-like growth factor-1 (IGF-1) expression. The suppressor of cytokine signaling (SOCS)-3 negatively regulates this intracellular cascade. We aimed to evaluate the hepatic expression of the GH/IGF-1 axis components in the liver of patients with HCV-related chronic hepatitis at different fibrosis stages. The expression of GH/IGF-1 axis components, such as GHR, IGF-1, STAT5-p, and SOCS-3, was assessed by immunohistochemistry at the lobular level in 61 patients with HCV-related hepatitis. At the hepatocyte level, IGF-1 and nuclear STAT5-p positivity scores showed negative correlations with fibrosis stage, while SOCS-3 score a positive one (p<0.05 for all). Furthermore, the reduction of hepatocyte score of IGF-1 expression was associated with the serological parameters of liver damage (p<0.05) and with the increase of the score of IGF-1 expression by hepatic stellate cells (p<0.05). IGF-1 expression by hepatocytes was reduced with fibrosis progression, probably due to the impairment of GHR intracellular cascade by the SOCS-3 activation already in pre-cirrhotic stages. The inverse correlation between IGF-1 expressed by hepatocytes and by hepatic stellate cells suggests that IGF-1 may exert specific functions in different hepatic cells. © Georg Thieme Verlag KG Stuttgart · New York.

IL30 (IL27p28) attenuates liver fibrosis through inducing NKG2D-Rae1 interaction between NKT and activated hepatic stellate cells

PubMed Central

Mitra, Abhisek; Satelli, Arun; Yan, Jun; Xueqing, Xia; Gagea, Mihai; Hunter, Christopher A.; Mishra, Lopa; Li, Shulin

2014-01-01

Chronic hepatic diseases such as cirrhosis, hepatocellular carcinoma and virus mediated immunopathogenic infections are affecting billions of people worldwide. These diseases commonly initiate with fibrosis. Owing to the various side effects of anti-fibrotic therapy and the difficulty of diagnosing asymptomatic patients, suitable medication remains a major concern. To overcome this drawback, the use of cytokine-based sustained therapy might be a suitable alternative with minimal side effects. Here, we studied the therapeutic efficacy and potential mechanisms of IL30 as anti-fibrosis therapy in murine liver fibrosis models. Carbon tetrachloride (CCl4) mixed with corn oil at a ratio 1:3 was injected intraperitoneally (IP) 1µl/gm body weight twice per week for 1 month or 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) 0.1% (wt/wt) Purnima 5015 Chow was fed for 3 weeks to induce liver fibrosis. Either control vector (pCtr) or pIL30 was injected hydrodynamically once per week. A significant decrease in collagen deposition and reduced expression of α-smooth muscle Actin (αSMA) protein indicated that IL30–based gene therapy dramatically reduced bridging fibrosis that was induced by CCl4 or DDC. Immunophenotyping and knockout studies showed that IL30 recruits NKT cells to the liver to decrease activated hepatic stellate cells (HSCs) significantly and ameliorate liver fibrosis. Both flow cytometric and antibody mediated neutralization studies showed NKT cells alleviate liver fibrosis in an NKG2D dependent manner. Furthermore, chronic treatment with CCl4 showed inducible surface expression of the NKG2D ligand Rae1 on activated HSCs as compared to quiescent ones. Taken together, our results show that highly target specific liver NKT cells selectively remove activated HSCs via an NKG2D-Rae1 interaction to ameliorate liver fibrosis after IL30 treatment. PMID:25351459

Fatty Acid Binding Protein 4 (FABP4) Overexpression in Intratumoral Hepatic Stellate Cells within Hepatocellular Carcinoma with Metabolic Risk Factors.

PubMed

Chiyonobu, Norimichi; Shimada, Shu; Akiyama, Yoshimitsu; Mogushi, Kaoru; Itoh, Michiko; Akahoshi, Keiichi; Matsumura, Satoshi; Ogawa, Kosuke; Ono, Hiroaki; Mitsunori, Yusuke; Ban, Daisuke; Kudo, Atsushi; Arii, Shigeki; Suganami, Takayoshi; Yamaoka, Shoji; Ogawa, Yoshihiro; Tanabe, Minoru; Tanaka, Shinji

2018-05-01

Metabolic syndrome is a newly identified risk factor for hepatocellular carcinoma (HCC); however, tumor-specific biomarkers still remain unclear. We performed cross-species analysis to compare gene signatures of HCC from human patients and melanocortin 4 receptor-knockout mice, which develop HCC with obesity, insulin resistance, and dyslipidemia. Unsupervised hierarchical clustering and principle component analysis of 746 differentially expressed orthologous genes classified HCC of 152 human patients and melanocortin 4 receptor-knockout mice into two distinct subgroups, one of which included mouse HCC and was causatively associated with metabolic risk factors. Nine genes commonly overexpressed in human and mouse metabolic disease-associated HCC were identified; fatty acid binding protein 4 (FABP4) was remarkably enriched in intratumoral activated hepatic stellate cells (HSCs). Subclones constitutively expressing FABP4 were established from a human HSC cell line in which expression levels of inflammatory chemokines, including IL-1A and IL-6, were up-regulated through NF-κB nuclear translocation, resulting in recruitment of macrophages. An immunohistochemical validation study of 106 additional human HCC samples indicated that FABP4-positive HSCs were distributed in tumors of 38 cases, and the FABP4-high group consisted of patients with nonviral and nonalcoholic HCC (P = 0.027) and with multiple metabolic risk factors (P < 0.001) compared with the FABP4-low group. Thus, FABP4 overexpression in HSCs may contribute to hepatocarcinogenesis in patients with metabolic risk factors by modulation of inflammatory pathways. Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Modified citrus pectin stops progression of liver fibrosis by inhibiting galectin-3 and inducing apoptosis of stellate cells.

PubMed

Abu-Elsaad, Nashwa M; Elkashef, Wagdi Fawzi

2016-05-01

Modified citrus pectin (MCP) is a pH modified form of the dietary soluble citrus peel fiber known as pectin. The current study aims at testing its effect on liver fibrosis progression. Rats were injected with CCl4 (1 mL/kg, 40% v/v, i.p., twice a week for 8 weeks). Concurrently, MCP (400 or 1200 mg/kg) was administered daily in drinking water from the first week in groups I and II (prophylactic model) and in the beginning of week 5 in groups III and IV (therapeutic model). Liver function biomarkers (ATL, AST, and ALP), fibrosis markers (laminin and hyaluronic acid), and antioxidant biomarkers (reduced glutathione (GSH) and superoxide dismutase (SOD)) were measured. Stained liver sections were scored for fibrosis and necroinflammation. Additionally, expression of galectin-3 (Gal-3), α-smooth muscle actin (SMA), tissue inhibitor metalloproteinase (TIMP)-1, collagen (Col)1A1, caspase (Cas)-3, and apoptosis related factor (FAS) were assigned. Modified pectin late administration significantly (p < 0.05) decreased malondialdehyde (MDA), TIMP-1, Col1A1, α-SMA, and Gal-3 levels and increased levels of FAS, Cas-3, GSH, and SOD. It also decreased percentage of fibrosis and necroinflammation significantly (p < 0.05). It can be concluded that MCP can attenuate liver fibrosis through an antioxidant effect, inhibition of Gal-3 mediated hepatic stellate cells activation, and induction of apoptosis.

[Hepatic artery of the rat in experimental cirrhosis of the liver].

PubMed

Baĭbekov, I M; Vorozheĭkin, V M; Khoroshaev, V A; Khamidov, P M

1984-04-01

In 30 male rats of Wistar strain (20 more rats served as controls) thickness of the internal elastic membrane, that of the media, cross section area of the media and that of the lumen were define 3, 4, 5 and 6 months after the experiment was started. The initial changes in the hepatic artery structure are noted on the 4th month, however, differences in the parameters are not yet statistically significant. On the 5th month certain signs of hypertrophy in the smooth muscle cells of the media are clearly seen, as well as an increasing thickness of the internal elastic membrane and that of the tunica media. Simultaneously, the index of labelling the myocyte nuclei reaches its maximum. The increasing thickness of the arterial wall causes certain decrease in the lumen cross section area. The changes of all the parameters are statistically significant. In 6 months after the beginning of the experiment, a pronounced hyperelastosis develops in the wall of the hepatic artery; a part of the smooth muscle cells in the tunica media undergoes atrophy. The area of the vascular lumen decreases by 16%, comparing to the age control. The experimental data confirm certain clinical observations and reveal some features in the mechanism of pathological changes occurring in the hepatic artery wall at cirrhosis.

Protective Effect of Ethyl Acetate Fraction of Stereospermum Suaveolens Against Hepatic Oxidative Stress in STZ Diabetic Rats.

PubMed

Balasubramanian, Thirumalaiswamy; Senthilkumar, G P; Karthikeyan, M; Chatterjee, Tapan Kumar

2013-07-01

Stereospermum suaveolens is a folk remedy for the treatment of diabetes and liver disorders in southern parts of India. In the present study, the protective effect of the ethyl acetate fraction of ethanol extract from S. suaveolens against hepatic oxidative stress was evaluated in streptozotocin (STZ)-induced diabetic rats for 14 days. The ethyl acetate fraction was administered orally to the STZ diabetic rats at the doses of 200 and 400 mg/kg. Blood glucose level was measured according to glucose oxidase method. In order to determine hepatoprotective activity, changes in the levels of serum biomarker enzymes such as aspartate transaminase (AST), alanine transaminase (ALT), and serum alkaline phosphatase (SALP) were assessed in the ethyl acetate fraction treated diabetic rats and were compared with the levels in diabetic control rats. In addition, the antioxidant activity of ethyl acetate fraction was evaluated using various hepatic parameters such as thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). It was found that administration of ethyl acetate fraction (200 and 400 mg/kg) produced a significant (P < 0.001) fall in fasting blood glucose level, TBARS, bilirubin, AST, ALT, and SALP, while elevating the GSH levels, and SOD and CAT activities in diabetic rats. Histopathologic studies also revealed the protective effect of ethyl acetate fraction on the liver tissues of diabetic rats. It was concluded from this study that the ethyl acetate fraction from ethanol extract of S. suaveolens modulates the activity of enzymatic and nonenzymatic antioxidants and enhances the defense against hepatic oxidative stress in STZ-induced diabetic rats.

Profiles of metabolites and gene expression in rats with chemically induced hepatic necrosis.

PubMed

Heijne, Wilbert H M; Lamers, Robert-Jan A N; van Bladeren, Peter J; Groten, John P; van Nesselrooij, Joop H J; van Ommen, Ben

2005-01-01

This study investigated whether integrated analysis of transcriptomics and metabolomics data increased the sensitivity of detection and provided new insight in the mechanisms of hepatotoxicity. Metabolite levels in plasma or urine were analyzed in relation to changes in hepatic gene expression in rats that received bromobenzene to induce acute hepatic centrilobular necrosis. Bromobenzene-induced lesions were only observed after treatment with the highest of 3 dose levels. Multivariate statistical analysis showed that metabolite profiles of blood plasma were largely different from controls when the rats were treated with bromobenzene, also at doses that did not elicit histopathological changes. Changes in levels of genes and metabolites were related to the degree of necrosis, providing putative novel markers of hepatotoxicity. Levels of endogenous metabolites like alanine, lactate, tyrosine and dimethylglycine differed in plasma from treated and control rats. The metabolite profiles of urine were found to be reflective of the exposure levels. This integrated analysis of hepatic transcriptomics and plasma metabolomics was able to more sensitively detect changes related to hepatotoxicity and discover novel markers. The relation between gene expression and metabolite levels was explored and additional insight in the role of various biological pathways in bromobenzene-induced hepatic necrosis was obtained, including the involvement of apoptosis and changes in glycolysis and amino acid metabolism. The complete Table 2 is available as a supplemental file online at http://taylorandfrancis.metapress.com/openurlasp?genre=journal&issn=0192-6233. To access the file, click on the issue link for 33(4), then select this article. A download option appears at the bottom of this abstract. In order to access the full article online, you must either have an individual subscription or a member subscription accessed through www.toxpath.org.

Quercetin dose affects the fate of hepatic ischemia and reperfusion injury in rats: An experimental research.

PubMed

Uylaş, Mustafa Ufuk; Şahin, Adnan; Şahintürk, Varol; Alataş, İbrahim Özkan

2018-05-01

Quercetin found in fruits and vegetables has an antioxidative effect. We aimed to investigate the protective effects of quercetin according to different doses on hepatic and ischemia-reperfusion (I/R) injury. Fifty mature male Sprague-Dawley rats were randomly divided into five groups (n = 10 for each). All the animal groups underwent laparotomy. Group 1 rats served as a sham-operated group. Groups 2-5 underwent 1 h hepatic ischemia and were followed by 2 h reperfusion. Group 3-5 animals received an additional intraperitoneal dose of 25, 50 or 100 mg/kg quercetin respectively before I/R operation. Blood samples were collected for determining serum aspartate transaminase (AST), alanine transaminase (ALT) and malondialdehyde (MDA) levels. Also, liver tissue samples were taken for measuring of liver MDA concentration and for histopathology assessment. The highest levels of biochemical parameters were observed in group 2. In quercetin-treated groups, serum AST, ALT, MDA levels, and tissue MDA concentration were decreased as inversely with increasing quercetin dose. Microscopic evaluation revealed that most conspicuous histological improvement was observed in 50 mg/kg quercetin co-treated rats. 25 and 100 mg/kg quercetin co-treatment could not protect completely against hepatic I/R injury. Quercetin can be effective in preventing of hepatic I/R injury when the correct dose was used. Copyright © 2018. Published by Elsevier Ltd.

Study of renal and hepatic toxicity in rats supplemented with creatine.

PubMed

Baracho, Nilo Cesar do Vale; Castro, Letícia Pereira de; Borges, Niara da Cunha; Laira, Patrícia Benício

2015-05-01

To evaluate the renal and hepatic function, through biochemical analysis after 14 days of creatine supplementation in physically inactive rats. Twenty four male, adult, Wistar rats were used which were kept in individual metabolic cages and were distributed into four groups, and received the following treatments by gavage:1) CONTROL: distilled water; 2)Creatine 0.5g/Kg/day; 3) Creatine 1g/Kg/day; 4) Creatine 2g/Kg/day. Their urinary outputs as well as food and water intake were daily measured. At the end of the experiment, the animals were euthanized and serum samples were stored for biochemical analysis. Creatine supplementation at the doses given produced no significant changes in plasma levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total protein, albumin, total cholesterol, HDL cholesterol, LDL cholesterol, VLDL cholesterol, triglycerides, glucose, creatinine, urea, and creatinine clearance, compared to control group (p> 0.05) Similarly, water and food intake, as well as urinary output, did not show significant changes among the four groups studied. At the doses used, oral creatine supplementation did not result in renal and/or hepatic toxicity.

L-Cysteine Administration Attenuates Pancreatic Fibrosis Induced by TNBS in Rats by Inhibiting the Activation of Pancreatic Stellate Cell

PubMed Central

Hu, GuoYong; Shen, Jie; Wang, Feng; Xu, Ling; Dai, WeiQi; Xiong, Jie; Ni, JianBo; Guo, ChuanYong; Wan, Rong; Wang, XingPeng

2012-01-01

Background and Aims Recent studies have shown that activated pancreatic stellate cells (PSCs) play a major role in pancreatic fibrogenesis. We aimed to study the effect of L-cysteine administration on fibrosis in chronic pancreatitis (CP) induced by trinitrobenzene sulfonic acid (TNBS) in rats and on the function of cultured PSCs. Methods CP was induced by TNBS infusion into rat pancreatic ducts. L-cysteine was administrated for the duration of the experiment. Histological analysis and the contents of hydroxyproline were used to evaluate pancreatic damage and fibrosis. Immunohistochemical analysis of α-SMA in the pancreas was performed to detect the activation of PSCs in vivo. The collagen deposition related proteins and cytokines were determined by western blot analysis. DNA synthesis of cultured PSCs was evaluated by BrdU incorporation. We also evaluated the effect of L-cysteine on the cell cycle and cell activation by flow cytometry and immunocytochemistry. The expression of PDGFRβ, TGFβRII, collagen 1α1 and α-SMA of PSCs treated with different concentrations of L-cysteine was determined by western blot. Parameters of oxidant stress were evaluated in vitro and in vivo. Nrf2, NQO1, HO-1, IL-1β expression were evaluated in pancreas tissues by qRT-PCR. Results The inhibition of pancreatic fibrosis by L-cysteine was confirmed by histological observation and hydroxyproline assay. α-SMA, TIMP1, IL-1β and TGF-β1 production decreased compared with the untreated group along with an increase in MMP2 production. L-cysteine suppressed the proliferation and extracellular matrix production of PSCs through down-regulating of PDGFRβ and TGFβRII. Concentrations of MDA+4-HNE were decreased by L-cysteine administration along with an increase in GSH levels both in tissues and cells. In addition, L-cysteine increased the mRNA expression of Nrf2, NQO1 and HO-1 and reduced the expression of IL-1β in L-cysteine treated group when compared with control group. Conclusion L

Effects of creatine supplementation on biomarkers of hepatic and renal function in young trained rats.

PubMed

Souza, William Marciel; Heck, Thiago Gomes; Wronski, Evanio Castor; Ulbrich, Anderson Zampier; Boff, Everton

2013-11-01

Creatine supplementation has been widely used by athletes and young physical exercise practioneers in order of increasing muscle mass and enhancing athletic performance, but their use/overuse may represent a health risk on hepatic and renal impaired function. In this study, we evaluated the effects of 40 days of oral creatine supplementation on hepatic and renal function biomarkers in a young animal model. Wistar rats (5 weeks old) were divided in five groups (n = 7): control (CONTR), oral creatine supplementation (CREAT), moderate exercise training (EXERC), moderate exercise training plus oral creatine supplementation (EXERC + CREAT) and pathological group (positive control for liver and kidney injury) by the administration of rifampicin (RIFAMPICIN). Exercise groups were submitted to 60 min/day of swimming exercise session with a 4% of body weight workload for six weeks. The EXERC + CREAT showed the higher body weight at the end of the training protocol. The CREAT and EXERC + CREAT group showed an increase in hepatic (Aspartate transaminase and gamma-glutamyl transpeptidase) and renal (urea and creatinine) biomarkers levels (p < 0.05). Our study showed that the oral creatine supplementation promoted hepatic and renal function challenge in young rats submitted to moderate exercise training.

Early stellate cell activation and veno-occlusive-disease (VOD)-like hepatotoxicity in dogs treated with AR-H047108, an imidazopyridine proton pump inhibitor.

PubMed

Berg, Anna-Lena; Böttcher, Gerhard; Andersson, Kjell; Carlsson, Enar; Lindström, Anna-Karin; Huby, Russell; Håkansson, Helen; Skånberg-Wilhelmsson, Inger; Hellmold, Heike

2008-07-01

Dogs treated with AR-H047108, an imidazopyridine potassium competitive acid blocker (P-CAB), developed clinical signs of hepatic dysfunction as well as morphologically manifest hepatotoxicity in repeat-dose toxicity studies. An investigative one-month study was performed, with interim euthanasia after one and two weeks. A detailed histopathological and immunohistochemical characterization of the liver lesions was conducted, including markers for fibrosis, Kupffer cell activation, apoptosis, and endothelial injury. In addition, hepatic retinoid and procollagen 1alpha2 mRNA levels in livers of dogs treated with AR-H047108 were analyzed. The results showed an early inflammatory process in central veins and centrilobular areas, present after one week of treatment. This inflammatory reaction was paralleled by activation of stellate/Ito cells to myofibroblasts and was associated with sinusoidal and centrivenular fibrosis. The early activation of stellate cells coincided with a significant decrease in retinyl ester levels, and a significant increase in procollagen 1alpha2 mRNA levels, in the liver. At later time points (three and six months), there was marked sinusoidal fibrosis in centrilobular areas, as well as occlusion of central veins resulting from a combination of fibrosis and increased thickness of smooth muscle bundles in the vessel wall. The pattern of lesions suggests a veno-occlusive-disease (VOD)-like scenario, possibly linked to the imidazopyridine chemical structure of the compound facilitated by specific morphological features of the dog liver.

Ascorbic acid deficiency stimulates hepatic expression of inflammatory chemokine, cytokine-induced neutrophil chemoattractant-1, in scurvy-prone ODS rats.

PubMed

Horio, Fumihiko; Kiyama, Keiichiro; Kobayashi, Misato; Kawai, Kaori; Tsuda, Takanori

2006-02-01

ODS rat has a hereditary defect in ascorbic acid biosynthesis and is a useful animal model for elucidating the physiological role of ascorbic acid. We previously demonstrated by using ODS rats that ascorbic acid deficiency changes the hepatic gene expression of acute phase proteins, as seen in acute inflammation. In this study, we investigated the effects of ascorbic acid deficiency on the production of inflammatory chemokine, cytokine-induced neutrophil chemoattractant-1 (CINC-1), in ODS rats. Male ODS rats (6 wk of age) were fed a basal diet containing ascorbic acid (300 mg/kg diet) or a diet without ascorbic acid for 14 d. Obvious symptoms of scurvy were not observed in the ascorbic acid-deficient rats. Ascorbic acid deficiency significantly elevated the serum concentration of CINC-1 on d 14. The liver and spleen CINC-1 concentrations in the ascorbic acid-deficient rats were significantly elevated to 600% and 180% of the respective values in the control rats. However, the lung concentration of CINC-1 was not affected by ascorbic acid deficiency. Ascorbic acid deficiency significantly elevated the hepatic mRNA level of CINC-1 (to 480% of the value in the control rats), but not the lung mRNA level. These results demonstrate that ascorbic acid deficiency elevates the serum, liver and spleen concentrations of CINC-1 as seen in acute inflammation, and suggest that ascorbic acid deficiency stimulate the hepatic CINC-1 gene expression.

Long-Time Choledochal Clamping in Wistar Rats Causes Biliary Obstruction Progressing to Hepatic Fibrosis.

PubMed

Jorge, G D L; Tártaro, R R; Escanhoela, C A F; Boin, I D F S F

2016-09-01

Biliary complications are important causes of morbidity and mortality in patients undergoing hepatic surgery. The aim of the study was to evaluate late liver alterations after a long period of choledochal clamping in Wistar rats. Ten male Wistar rats, weighing 304 grams, anesthetized with sodium thiopental (25 mg/kg) and xylazine (10 mg/kg) intravenously, were distributed into 2 groups: the choledochal clamping group (CCG) and the operation sham group (OSG), with 5 animals each submitted to an abdominal incision. In the CCG, the choledochal was isolated, dissected, and clamped with a microvascular clamp for 40 minutes. After this occlusion time, the clamp was removed and the incision was closed. In the OSG the animals, under normal conditions, were submitted only to anesthesia and laparotomy for choledochal manipulation. In all animals, after the 31st day, a hepatic biopsy was carried out for histology and blood biochemical tests: total bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase. The animals were euthanized under anesthesia. This research was approved by the Ethics Committee on Animal Use (CEUA, Unicamp, No. 2511-1). In the CCG, 100% of the animals showed bile duct dilatation, ductular proliferation, and portal inflammatory infiltrate; 60% showed regenerative nodule formation; and 80% had porta-porta septa and foci of necrosis, all of which were not found in the OSG. All CCG group biochemical tests had significant increases (P < .05) compared with OSG. Long-time choledochal clamping in Wistar rats caused hepatic dysfunction and biochemical and histological injuries with degrees of distortion to the hepatic architecture. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of Green Tea Extract Encapsulated Into Chitosan Nanoparticles on Hepatic Fibrosis Collagen Fibers Assessed by Atomic Force Microscopy in Rat Hepatic Fibrosis Model.

PubMed

Safer, Abdel-Majeed A; Hanafy, Nomany A; Bharali, Dhruba J; Cui, Huadong; Mousa, Shaker A

2015-09-01

The present study examined the effect of Green Tea Extract (GTE) encapsulated into Chitosan Nanoparticles (CS-NPs) on hepatic fibrosis in rat model as determined by atomic force microscopy (AFM). The bioactive compounds in GTE encapsulated into CS-NPs were determined using LC-MS/MS method. Additionally, the uptake of GTE-CS NPs in HepG2 cells showed enhanced uptake. In experimental fibrosis model, AFM was used as a high resolution microscopic tool to investigate collagen fibers as an indicator of hepatic fibrosis induced by treatment with CCl4. Paraffin sections of fibrotic liver tissues caused by CC4 treatment of rats and the effect of GTE-CS NPs treatment with or without CCl4 on hepatic fibrosis were examined. Liver tissues from the different groups of animals were de-waxed and processed as for normal H/E staining and Masson's trichrome staining to locate the proper area of ECM collagen in the CCl4 group versus collagen in liver tissues treated with the GTE-CS NPs with or without CCl4. Selected areas of paraffin sections were trimmed off and fixed flat on top of mica and inserted in the AFM stage. H/E staining, Masson's trichrome stained slides, and AFM images revealed that collagen fibers of 250 to 300 nm widths were abundant in the fibrotic liver samples while those of GTE-CS NPs were clear as in the control group. Data confirmed the hypothesis that GTE-CS NPs are effective in removing all the extracellular collagen caused by CCl4 in the hepatic fibrosis rat liver.

Effect of chronic administration of mestranol, tamoxifen, and toremifene on hepatic ploidy in rats.

PubMed

Dragan, Y P; Shimel, R J; Bahnub, N; Sattler, G; Vaughan, J R; Jordan, V C; Pitot, H C

1998-06-01

The nonsteroidal antiestrogen tamoxifen increases the incidence of rat liver cancer through a variety of mechanisms. To compare the effects of tamoxifen (TAM) and a structurally similar analog toremifene (TOR) on rat liver, we determined the ploidy distribution for hepatocytes isolated from rats treated for 18 months with these antiestrogens or the estrogenic compound mestranol (MS). Female Sprague-Dawley rats were subjected to a 70% partial hepatectomy and administered the solvent, trioctanoin, or diethylnitrosamine (10 mg DEN/kg). After a 2-week recovery from the surgery, the rats were administered a basal diet or one containing TAM (250 or 500 ppm), TOR (250, 500, or 750 ppm), or MS (0.2 ppm) for 18 months. Pathologic changes in the liver were examined in the 15-22 rats per treatment group at the 18-month time point. An increased incidence of hepatocellular carcinomas (HCC) was detected in the 500 ppm TAM group, but not with the other treatments that did not include DEN. Both TOR and TAM promoted formation of DEN-initiated HCCs. At sacrifice, four to five rats per group were perfused and the hepatocytes isolated and cultured. Karyotypic analysis was performed on colcemid-blocked cells after 2 days in culture. The hepatic ploidy distribution was characterized in Giemsa-stained metaphase spreads. These studies indicated that chronic treatment with TAM alone resulted in a shift from tetraploid to diploid, as was also observed for rats treated once with DEN. TOR and MS alone did not cause this change in hepatic ploidy at the doses examined. A shift toward an increased content of diploid hepatocytes occurred in all rats treated once with DEN followed by TAM, TOR, or MS. These results indicate that tamoxifen administration results in a shift toward growth of diploid hepatocytes, thus contributing to its carcinogenic action in the rat liver.

Use of unripe plantain (Musa paradisiaca) in the management of diabetes and hepatic dysfunction in streptozotocin induced diabetes in rats

PubMed Central

Okafor, Polycarp

2015-01-01

Aim This study aims to investigate the effect of unripe plantain (Musa paradisiaca) on markers of hepatic dysfunction in streptozotocin induced diabetic rats. Methods Blood glucose; relative liver weight (RLW); relative kidney weight (RKW); relative heart weight (RHW); relative pancreatic weight (RPW); serum and hepatic serum aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP); serum amylase, lipase, total, and conjugated bilirubin; and chemical analysis of the test feed were determined using standard techniques. Results The diabetic rats had significant alteration (P < 0.05) of blood glucose; RLW; RKW; RPW; serum and hepatic AST, ALT, and ALP; serum total and conjugated bilirubin; and serum lipase activities compared with nondiabetic while these parameters were significantly improved (P < 0.05) in the rats fed unripe plantain. There were no significant differences (P > 0.05) in the RHW of the rats in the three groups, as well as significant decreases (P < 0.05) in the amylase levels of the diabetic rats compared with the nondiabetic, but there was nonsignificant increase (P > 0.05) in the amylase levels of the rats fed unripe plantain compared with the nondiabetic rats. The test and standard rat feeds contained considerable amount of proteins, carbohydrates, fats, phenols, and crude fiber. Conclusion Amelioration of acute pancreatitis by unripe plantain could play a key role in its management of diabetes and related complications. PMID:25838921

Use of unripe plantain (Musa paradisiaca) in the management of diabetes and hepatic dysfunction in streptozotocin induced diabetes in rats.

PubMed

Eleazu, Chinedum O; Okafor, Polycarp

2015-03-01

This study aims to investigate the effect of unripe plantain (Musa paradisiaca) on markers of hepatic dysfunction in streptozotocin induced diabetic rats. Blood glucose; relative liver weight (RLW); relative kidney weight (RKW); relative heart weight (RHW); relative pancreatic weight (RPW); serum and hepatic serum aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP); serum amylase, lipase, total, and conjugated bilirubin; and chemical analysis of the test feed were determined using standard techniques. The diabetic rats had significant alteration (P < 0.05) of blood glucose; RLW; RKW; RPW; serum and hepatic AST, ALT, and ALP; serum total and conjugated bilirubin; and serum lipase activities compared with nondiabetic while these parameters were significantly improved (P < 0.05) in the rats fed unripe plantain. There were no significant differences (P > 0.05) in the RHW of the rats in the three groups, as well as significant decreases (P < 0.05) in the amylase levels of the diabetic rats compared with the nondiabetic, but there was nonsignificant increase (P > 0.05) in the amylase levels of the rats fed unripe plantain compared with the nondiabetic rats. The test and standard rat feeds contained considerable amount of proteins, carbohydrates, fats, phenols, and crude fiber. Amelioration of acute pancreatitis by unripe plantain could play a key role in its management of diabetes and related complications.

Agmatine protects rat liver from nicotine-induced hepatic damage via antioxidative, antiapoptotic, and antifibrotic pathways.

PubMed

El-Sherbeeny, Nagla A; Nader, Manar A; Attia, Ghalia M; Ateyya, Hayam

2016-12-01

Tobacco smoking with its various forms is a global problem with proved hazardous effects to human health. The present work was planned to study the defending role of agmatine (AGM) on hepatic oxidative stress and damage induced by nicotine in rats. Thirty-two rats divided into four groups were employed: control group, nicotine-only group, AGM group, and AGM-nicotine group. Measurements of serum hepatic biochemical markers, lipid profile, and vascular cell adhesion molecule-1 were done. In addition, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) activity, and nitrate/nitrite (NOx) levels were estimated in the liver homogenates. Immunohistochemistry for Bax and transforming growth factor beta (TGF-β1) and histopathology of the liver were also included. Data of the study demonstrated that nicotine administration exhibited marked liver deterioration, an increase in liver enzymes, changes in lipid profile, and an elevation in MDA with a decline in levels of SOD, GSH, and NOx (nitrate/nitrite). Also, levels of proapoptotic Bax and profibrotic TGF-β1 showed marked elevation in the liver. AGM treatment to rats in nicotine-only group ameliorated all the previous changes. These findings indicate that AGM could successfully overcome the nicotine-evoked hepatic oxidative stress and tissue injury, apoptosis, and fibrosis.

Studies on cadmium-induced inhibition of hepatic microsomal drug biotransformation in the rat.

PubMed Central

Schnell, R C; Means, J R; Roberts, S A; Pence, D H

1979-01-01

Cadmium is a potent inhibitor of hepatic microsomal drug biotransformation in the rat. Male rats receiving a single intraperitoneal dose of cadmium exhibit significant decreases in hepatic microsomal metabolism of a variety of substrates. The threshold cadmium dose is 0.84 mg Cd/kg, and the effect lasts at least 28 days. Mechanistically, the inhibitory effect results from decreased cytochrome P-450 content since cadmium does not alter NADPH cytochrome c reductase activity. This effect is also observed following acute oral administration of cadmium in doses greater than 80 mg Cd/kg but is not observed following chronic administration of the metal via drinking water in concentrations of 5-200 ppm for periods ranging from 2 to 50 weeks. A tolerance to the inhibitory cadmium effect is observed if male rats are pretreated with subthreshold doses of the metal prior to the challenge cadmium dose. The degree of tolerance can be overcome by increasing the challenge dose of cadmium. Characterization of the tolerance phenomenon in terms of onset, duration, and intensity reveals a good correlation with the kinetics of metallothionein production, suggesting that the underlying basis for the tolerance phenomenon is likely the induction of metallothionein. A sex-related difference in the inhibitory effect of cadmium was observed. Cadmium did not inhibit the metabolism of hexobarbital or ethylmorphine in female rats but did inhibit that of aniline or zoxazolamine. Cadmium did not lower cytochrome P-450 content in female rats. PMID:488042

Regional traumatic limb hypothermia attenuates distant hepatic and renal injury following blast limb trauma in rats.

PubMed

Zhao, Hongzhi; Ning, Jiaolin; Duan, Jiaxiang; Gu, Jianteng; Yi, Bin; Lu, Kaizhi; Mo, Liwen; Lai, Xinan; Hennah, Lindsay; Ma, Daqing

2014-09-01

Blast limb injury was reported to result in distant organ injury including the lungs, which can be attenuated with transient regional hypothermia (RH) to the injured limb. We aimed to further study hepatic and renal injuries following blast limb trauma and also to evaluate the protective effects of regional traumatic limb hypothermia on such injuries in rats. Blast limb trauma (BLT) was created using chartaceous electricity detonators in anesthetized male Sprague-Dawley rats. The BLT rats were randomly allocated to undergo regional traumatic limb hypothermic treatment (RH) for 30 minutes, 60 minutes, or 6 hours immediately after the onset of blast or without RH (n = 8 per group). The severity of hepatic and renal injury was assessed through histologic examination and water content (wet/dry weight) in all animals 6 hours later. The level of plasma tumor necrosis factor α (TNF-α), interleukin 6, hydrogen sulfide (H2S), and myeloperoxidase (MPO) together with hepatic and renal MPO, malondialdehyde (MDA), superoxide dismutase, and total antioxidant capacity were measured 6 hours after the blast injury. Following BLT, hepatic injury was evidenced by histopathologic changes, increased water content, as well as plasma alanine aminotransferase and aspartate aminotransferase. Renal histopathologic but not functional changes were also found. RH treatment for all durations attenuated this distant renal injury, but only RH treatment for 60 minutes and 6 hours attenuated distant hepatic injury following BLT. RH treatment for all durations decreased plasma TNF-α and interleukin 6, reduced liver and kidney MPO activity and kidney MDA, and elevated superoxide dismutase and total antioxidant capacity in both liver and kidneys. RH treatment for 60 minutes is the most effective duration to reduce hepatic MPO activity, plasma TNF-α, and kidney MDA. This study indicates that BLT-induced distant renal and hepatic injury could be attenuated by RH treatment through reduction of

A Chinese herbal medicine, jia-wei-xiao-yao-san, prevents dimethylnitrosamine-induced hepatic fibrosis in rats.

PubMed

Chien, Shu-Chen; Chang, Wei-Chiao; Lin, Pu-Hua; Chang, Wei-Pin; Hsu, Shih-Chung; Chang, Jung-Chen; Wu, Ya-Chieh; Pei, Jin-Kuo; Lin, Chia-Hsien

2014-01-01

Jia-wei-xiao-yao-san (JWXYS) is a traditional Chinese herbal medicine that is widely used to treat neuropsychological disorders. Only a few of the hepatoprotective effects of JWXYS have been studied. The aim of this study was to investigate the hepatoprotective effects of JWXYS on dimethylnitrosamine- (DMN-) induced chronic hepatitis and hepatic fibrosis in rats and to clarify the mechanism through which JWXYS exerts these effects. After the rats were treated with DMN for 3 weeks, serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) levels were significantly elevated, whereas the albumin level decreased. Although DMN was continually administered, after the 3 doses of JWXYS were orally administered, the SGOT and SGPT levels significantly decreased and the albumin level was significantly elevated. In addition, JWXYS treatment prevented liver fibrosis induced by DMN. JWXYS exhibited superoxide-dismutase-like activity and dose-dependently inhibited DMN-induced lipid peroxidation and xanthine oxidase activity in the liver of rats. Our findings suggest that JWXYS exerts antifibrotic effects against DMN-induced chronic hepatic injury. The possible mechanism is at least partially attributable to the ability of JWXYS to inhibit reactive-oxygen-species-induced membrane lipid peroxidation.

Postnatal overfeeding promotes early onset and exaggeration of high-fat diet-induced nonalcoholic fatty liver disease through disordered hepatic lipid metabolism in rats.

PubMed

Ji, Chenlin; Dai, Yanyan; Jiang, Weiwei; Liu, Juan; Hou, Miao; Wang, Junle; Burén, Jonas; Li, Xiaonan

2014-11-01

Exposure to overnutrition in critical or sensitive developmental periods may increase the risk of developing obesity and metabolic syndrome in adults. Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome, but the relationship among postnatal nutrition, lipid metabolism, and NAFLD progression during development remains poorly understood. Here we investigated in a rat model whether postnatal overfeeding increases susceptibility to NAFLD in response to a high-fat diet. Litters from Sprague-Dawley dams were culled to three (small litters) or ten (normal litters) pups and then weaned onto a standard or high-fat diet at postnatal day 21 to generate normal-litter, small-litter, normal-litter/high-fat, and small-litter/high-fat groups. At age 16 weeks, the small-litter and both high-fat groups showed obesity, dyslipidemia, and insulin resistance. Hepatic disorders appeared earlier in the small-litter/high-fat rats with greater liver mass gain and higher hepatic triglycerides and steatosis score versus normal-litter/high-fat rats. Hepatic acetyl-CoA carboxylase activity and mRNA expression were increased in small-litter rats and aggravated in small-litter/high-fat rats but not in normal-litter/high-fat rats. The high expression in small-litter/high-fat rats coincided with high sterol regulatory element-binding protein-1c mRNA and protein expression. However, mRNA expression of enzymes involved in hepatic fatty acid oxidation (carnitine palmitoyltransferase 1) and output (microsomal triglyceride transfer protein) was decreased under a high-fat diet regardless of litter size. In conclusion, overfeeding related to small-litter rearing during lactation contributes to the NAFLD phenotype when combined with a high-fat diet, possibly through up-regulated hepatic lipogenesis. Copyright © 2014 Elsevier Inc. All rights reserved.

Detection of rat hepatitis E virus in wild Norway rats (Rattus norvegicus) and Black rats (Rattus rattus) from 11 European countries.

PubMed

Ryll, René; Bernstein, Samuel; Heuser, Elisa; Schlegel, Mathias; Dremsek, Paul; Zumpe, Maxi; Wolf, Sandro; Pépin, Michel; Bajomi, Daniel; Müller, Gabi; Heiberg, Ann-Charlotte; Spahr, Carina; Lang, Johannes; Groschup, Martin H; Ansorge, Hermann; Freise, Jona; Guenther, Sebastian; Baert, Kristof; Ruiz-Fons, Francisco; Pikula, Jiri; Knap, Nataša; Tsakmakidis, Ιoannis; Dovas, Chrysostomos; Zanet, Stefania; Imholt, Christian; Heckel, Gerald; Johne, Reimar; Ulrich, Rainer G

2017-09-01

Rat hepatitis E virus (HEV) is genetically only distantly related to hepeviruses found in other mammalian reservoirs and in humans. It was initially detected in Norway rats (Rattus norvegicus) from Germany, and subsequently in rats from Vietnam, the USA, Indonesia, China, Denmark and France. Here, we report on a molecular survey of Norway rats and Black rats (Rattus rattus) from 12 European countries for ratHEV and human pathogenic hepeviruses. RatHEV-specific real-time and conventional RT-PCR investigations revealed the presence of ratHEV in 63 of 508 (12.4%) rats at the majority of sites in 11 of 12 countries. In contrast, a real-time RT-PCR specific for human pathogenic HEV genotypes 1-4 and a nested broad-spectrum (NBS) RT-PCR with subsequent sequence determination did not detect any infections with these genotypes. Only in a single Norway rat from Belgium a rabbit HEV-like genotype 3 sequence was detected. Phylogenetic analysis indicated a clustering of all other novel Norway and Black rat-derived sequences with ratHEV sequences from Europe, the USA and a Black rat-derived sequence from Indonesia within the proposed ratHEV genotype 1. No difference in infection status was detected related to age, sex, rat species or density of human settlements and zoological gardens. In conclusion, our investigation shows a broad geographical distribution of ratHEV in Norway and Black rats from Europe and its presence in all settlement types investigated. Copyright © 2017 Elsevier B.V. All rights reserved.

The CYP2E1 inhibitor DDC up-regulates MMP-1 expression in hepatic stellate cells via an ERK1/2- and Akt-dependent mechanism.

PubMed

Liu, Tianhui; Wang, Ping; Cong, Min; Xu, Youqing; Jia, Jidong; You, Hong

2013-06-05

DDC (diethyldithiocarbamate) could block collagen synthesis in HSC (hepatic stellate cells) through the inhibition of ROS (reactive oxygen species) derived from hepatocyte CYP2E1 (cytochrome P450 2E1). However, the effect of DDC on MMP-1 (matrix metalloproteinase-1), which is the main collagen degrading matrix metalloproteinase, has not been reported. In co-culture experiments, we found that DDC significantly enhanced MMP-1 expression in human HSC (LX-2) that were cultured with hepatocyte C3A cells either expressing or not expressing CYP2E1. The levels of both proenzyme and active MMP-1 enzyme were up-regulated in LX-2 cells, accompanied by elevated enzyme activity of MMP-1 and decreased collagen I, in both LX-2 cells and the culture medium. H2O2 treatment abrogated DDC-induced MMP-1 up-regulation and collagen I decrease, while catalase treatment slightly up-regulated MMP-1 expression. These data suggested that the decrease in ROS by DDC was partially responsible for the MMP-1 up-regulation. ERK1/2 (extracellular signal-regulated kinase 1/2), Akt (protein kinase B) and p38 were significantly activated by DDC. The ERK1/2 inhibitor (U0126) and Akt inhibitor (T3830) abrogated the DDC-induced MMP-1 up-regulation. In addition, a p38 inhibitor (SB203580) improved MMP-1 up-regulation through the stimulation of ERK1/2. Our data indicate that DDC significantly up-regulates the expression of MMP-1 in LX-2 cells which results in greater MMP-1 enzyme activity and decreased collagen I. The enhancement of MMP-1 expression by DDC was associated with H2O2 inhibition and coordinated regulation by the ERK1/2 and Akt pathways. These data provide some new insights into treatment strategies for hepatic fibrosis.

The CYP2E1 inhibitor DDC up-regulates MMP-1 expression in hepatic stellate cells via an ERK1/2- and Akt-dependent mechanism

PubMed Central

Liu, Tianhui; Wang, Ping; Cong, Min; Xu, Youqing; Jia, Jidong; You, Hong

2013-01-01

DDC (diethyldithiocarbamate) could block collagen synthesis in HSC (hepatic stellate cells) through the inhibition of ROS (reactive oxygen species) derived from hepatocyte CYP2E1 (cytochrome P450 2E1). However, the effect of DDC on MMP-1 (matrix metalloproteinase-1), which is the main collagen degrading matrix metalloproteinase, has not been reported. In co-culture experiments, we found that DDC significantly enhanced MMP-1 expression in human HSC (LX-2) that were cultured with hepatocyte C3A cells either expressing or not expressing CYP2E1. The levels of both proenzyme and active MMP-1 enzyme were up-regulated in LX-2 cells, accompanied by elevated enzyme activity of MMP-1 and decreased collagen I, in both LX-2 cells and the culture medium. H2O2 treatment abrogated DDC-induced MMP-1 up-regulation and collagen I decrease, while catalase treatment slightly up-regulated MMP-1 expression. These data suggested that the decrease in ROS by DDC was partially responsible for the MMP-1 up-regulation. ERK1/2 (extracellular signal-regulated kinase 1/2), Akt (protein kinase B) and p38 were significantly activated by DDC. The ERK1/2 inhibitor (U0126) and Akt inhibitor (T3830) abrogated the DDC-induced MMP-1 up-regulation. In addition, a p38 inhibitor (SB203580) improved MMP-1 up-regulation through the stimulation of ERK1/2. Our data indicate that DDC significantly up-regulates the expression of MMP-1 in LX-2 cells which results in greater MMP-1 enzyme activity and decreased collagen I. The enhancement of MMP-1 expression by DDC was associated with H2O2 inhibition and coordinated regulation by the ERK1/2 and Akt pathways. These data provide some new insights into treatment strategies for hepatic fibrosis. PMID:23577625

Protective Effect of Ethyl Acetate Fraction of Stereospermum Suaveolens Against Hepatic Oxidative Stress in STZ Diabetic Rats

PubMed Central

Balasubramanian, Thirumalaiswamy; Senthilkumar, G. P; Karthikeyan, M.; Chatterjee, Tapan Kumar

2013-01-01

Stereospermum suaveolens is a folk remedy for the treatment of diabetes and liver disorders in southern parts of India. In the present study, the protective effect of the ethyl acetate fraction of ethanol extract from S. suaveolens against hepatic oxidative stress was evaluated in streptozotocin (STZ)-induced diabetic rats for 14 days. The ethyl acetate fraction was administered orally to the STZ diabetic rats at the doses of 200 and 400 mg/kg. Blood glucose level was measured according to glucose oxidase method. In order to determine hepatoprotective activity, changes in the levels of serum biomarker enzymes such as aspartate transaminase (AST), alanine transaminase (ALT), and serum alkaline phosphatase (SALP) were assessed in the ethyl acetate fraction treated diabetic rats and were compared with the levels in diabetic control rats. In addition, the antioxidant activity of ethyl acetate fraction was evaluated using various hepatic parameters such as thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). It was found that administration of ethyl acetate fraction (200 and 400 mg/kg) produced a significant (P < 0.001) fall in fasting blood glucose level, TBARS, bilirubin, AST, ALT, and SALP, while elevating the GSH levels, and SOD and CAT activities in diabetic rats. Histopathologic studies also revealed the protective effect of ethyl acetate fraction on the liver tissues of diabetic rats. It was concluded from this study that the ethyl acetate fraction from ethanol extract of S. suaveolens modulates the activity of enzymatic and nonenzymatic antioxidants and enhances the defense against hepatic oxidative stress in STZ-induced diabetic rats. PMID:24716175

Comparative oxidative metabolism of BDE-47 and BDE-99 by rat hepatic microsomes.

PubMed

Erratico, Claudio A; Moffatt, Sarah C; Bandiera, Stelvio M

2011-09-01

Polybrominated diphenyl ethers (PBDEs) are flame-retardant chemicals that have become ubiquitous environmental pollutants. 2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) and 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) are among the most prevalent PBDEs detected in humans, wildlife, and abiotic environmental matrices. The purpose of this study was to investigate the oxidative metabolism of BDE-47 and BDE-99 in rat hepatic microsomes by comparing metabolite formation rates, kinetic parameters associated with metabolite formation, and the effects of prototypical cytochrome P450 (CYP) inducers. The CYP enzymes involved were also identified. Incubation of BDE-47 with hepatic microsomes from phenobarbital-treated rats generated a total of five hydroxylated (OH-BDE) metabolites, among which 4'-hydroxy-2,2',4,5'-tetrabromodiphenyl ether (4'-OH-BDE-49) and 3-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (3-OH-BDE-47) were the major metabolites, as identified using authentic standards and quantified by liquid chromatography/mass spectrometry. Incubations of BDE-99 with hepatic microsomes from dexamethasone-treated rats produced a total of seven hydroxylated metabolites, among which 4-hydroxy-2,2',3,4',5-pentabromodiphenyl ether (4-OH-BDE-90) and 6'-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (6'-OH-BDE-99) were the major metabolites. Although the overall rate of oxidative metabolism of BDE-99 by hepatic microsomes was greater than that of BDE-47, para-hydroxylation involving a National Institutes of Health shift mechanism represented a major metabolic pathway for both PBDE congeners. Among the rat recombinant CYP enzymes tested, CYP2A2 and CYP3A1 were the most active in BDE-47 and BDE-99 metabolism, respectively. However, CYP1A1 exhibited the highest activity for 4'-OH-BDE-49 and 6'-OH-BDE-99 formation, and CYP3A1 exhibited the highest activity for 3-OH-BDE-47 and 4-OH-BDE-90 formation. Collectively, the results demonstrate that oxidative metabolism of BDE-47 and BDE-99 is

Bile acids induce necrosis in pancreatic stellate cells dependent on calcium entry and sodium-driven bile uptake.

PubMed

Ferdek, Pawel E; Jakubowska, Monika A; Gerasimenko, Julia V; Gerasimenko, Oleg V; Petersen, Ole H

2016-11-01

Acute biliary pancreatitis is a sudden and severe condition initiated by bile reflux into the pancreas. Bile acids are known to induce Ca 2+ signals and necrosis in isolated pancreatic acinar cells but the effects of bile acids on stellate cells are unexplored. Here we show that cholate and taurocholate elicit more dramatic Ca 2+ signals and necrosis in stellate cells compared to the adjacent acinar cells in pancreatic lobules; whereas taurolithocholic acid 3-sulfate primarily affects acinar cells. Ca 2+ signals and necrosis are strongly dependent on extracellular Ca 2+ as well as Na + ; and Na + -dependent transport plays an important role in the overall bile acid uptake in pancreatic stellate cells. Bile acid-mediated pancreatic damage can be further escalated by bradykinin-induced signals in stellate cells and thus killing of stellate cells by bile acids might have important implications in acute biliary pancreatitis. Acute biliary pancreatitis, caused by bile reflux into the pancreas, is a serious condition characterised by premature activation of digestive enzymes within acinar cells, followed by necrosis and inflammation. Bile acids are known to induce pathological Ca 2+ signals and necrosis in acinar cells. However, bile acid-elicited signalling events in stellate cells remain unexplored. This is the first study to demonstrate the pathophysiological effects of bile acids on stellate cells in two experimental models: ex vivo (mouse pancreatic lobules) and in vitro (human cells). Sodium cholate and taurocholate induced cytosolic Ca 2+ elevations in stellate cells, larger than those elicited simultaneously in the neighbouring acinar cells. In contrast, taurolithocholic acid 3-sulfate (TLC-S), known to induce Ca 2+ oscillations in acinar cells, had only minor effects on stellate cells in lobules. The dependence of the Ca 2+ signals on extracellular Na + and the presence of sodium-taurocholate cotransporting polypeptide (NTCP) indicate a Na + -dependent bile acid

Bile acids induce necrosis in pancreatic stellate cells dependent on calcium entry and sodium‐driven bile uptake

PubMed Central

Jakubowska, Monika A.; Gerasimenko, Julia V.; Gerasimenko, Oleg V.; Petersen, Ole H.

2016-01-01

Key points Acute biliary pancreatitis is a sudden and severe condition initiated by bile reflux into the pancreas.Bile acids are known to induce Ca2+ signals and necrosis in isolated pancreatic acinar cells but the effects of bile acids on stellate cells are unexplored.Here we show that cholate and taurocholate elicit more dramatic Ca2+ signals and necrosis in stellate cells compared to the adjacent acinar cells in pancreatic lobules; whereas taurolithocholic acid 3‐sulfate primarily affects acinar cells.Ca2+ signals and necrosis are strongly dependent on extracellular Ca2+ as well as Na+; and Na+‐dependent transport plays an important role in the overall bile acid uptake in pancreatic stellate cells.Bile acid‐mediated pancreatic damage can be further escalated by bradykinin‐induced signals in stellate cells and thus killing of stellate cells by bile acids might have important implications in acute biliary pancreatitis. Abstract Acute biliary pancreatitis, caused by bile reflux into the pancreas, is a serious condition characterised by premature activation of digestive enzymes within acinar cells, followed by necrosis and inflammation. Bile acids are known to induce pathological Ca2+ signals and necrosis in acinar cells. However, bile acid‐elicited signalling events in stellate cells remain unexplored. This is the first study to demonstrate the pathophysiological effects of bile acids on stellate cells in two experimental models: ex vivo (mouse pancreatic lobules) and in vitro (human cells). Sodium cholate and taurocholate induced cytosolic Ca2+ elevations in stellate cells, larger than those elicited simultaneously in the neighbouring acinar cells. In contrast, taurolithocholic acid 3‐sulfate (TLC‐S), known to induce Ca2+ oscillations in acinar cells, had only minor effects on stellate cells in lobules. The dependence of the Ca2+ signals on extracellular Na+ and the presence of sodium–taurocholate cotransporting polypeptide (NTCP) indicate a Na

Expression of E-selectin ligand-1 (CFR/ESL-1) on hepatic stellate cells: implications for leukocyte extravasation and liver metastasis.

PubMed

Antoine, Marianne; Tag, Carmen G; Gressner, Axel M; Hellerbrand, Claus; Kiefer, Paul

2009-02-01

Leukocytes and tumor cells use E-selectin binding ligands to attach to activated endothelial cells expressing E-selectin during inflammation or metastasis. The cysteine-rich fibroblast growth factor receptor (CFR) represents the main E-selectin ligand (ESL-1) on granulocytes and its expression is exclusively modified by alpha(1,3)-fucosyltransferases IV or VII (FucT4 and FucT7). Hepatic stellate cells (HSC) are pericytes of liver sinusoidal endothelial cells. The activation of HSC and transdifferentiation into a myofibroblastic phenotype is involved in the repair of liver tissue injury, liver regeneration and angiogenesis of liver metastases. In the present study, we demonstrated that HSC expressed CFR together with FucT7 and exhibited a functional E-selectin binding activity on their cell surface. Since HSC appear to be oxygen-sensing cells, the expression of E-selectin binding activity was analyzed in HSC under a hypoxic atmosphere. While the expression of the glycoprotein CFR was unaffected by hypoxia, the cell-associated E-selectin binding activity decreased. However, under the same conditions, mRNA expression of the modifying enzyme FucT7 increased. The loss of E-selectin binding activity, therefore, appears to be neither the result of a reduced expression of the modifying transferase nor the expression of the backbone glycoprotein. After the transient transfection of HSC with CFR cDNA, the E-selectin binding activity (ESL-1) was efficiently released into the supernatant. Therefore, we hypothesize that under hypoxia, ESL-1 is shed from activated HSC. Our findings provide a novel perspective on the function of HSC in liver metastasis and inflammatory liver diseases.

Experiment K-6-14. Hepatic function in rats after spaceflight

NASA Technical Reports Server (NTRS)

Merrill, A., Jr.; Hoel, M.; Wang, E.; Jones, D.; Hargrove, J.; Mullins, R.; Popova, I.

1990-01-01

To determine the possible biochemical consequences of prolonged weightlessness on liver function, tissue samples from rats that had flown aboard Cosmos 1887 were analyzed for hepatic protein, glycogen and lipids as well as the activities of a number of key enzymes involved in metabolism of these compounds and xenobiotics. Among the parameters measured, the major differences were elevations in the hepatic glycogen content and HMG-CoA reductase activities of the rats flown on Cosmos 1887, and a decrease in the amount of microsomal cytochrome P sub 450 and the activity of aniline hydroxylase, a cytochrome P sub 450-dependent enzyme. Decreases in these two indices of the microsomal mixed-function oxidase system indicated that spaceflight may compromise the ability of liver to metabolize drugs and toxins. The higher HMG-CoA reductase correlated with elevated levels of serum cholestrol. Other changes included somewhat higher blood glucose, creatinine, SGOT, and much greater alkaline phosphatase and BUN. These results generally support the earlier observation of changes in these parameters (Merrill et al., Am. J. Physiol. 252:R22-R226, 1987). The importance of these alterations in liver function is not known; however, they have the potential to complicate long-term spaceflight.

Assessing activation of hepatic stellate cells by (99m)Tc-3PRGD2 scintigraphy targeting integrin αvβ3: a feasibility study.

PubMed

Zhang, Xin; Xin, Jun; Shi, Yu; Xu, Weina; Yu, Shupeng; Yang, Zhiguang; Liu, Changping; Cao, Li; Guo, Qiyong

2015-03-01

Hepatic stellate cell (HSC) activation, which is accompanied by increased expression of integrin αvβ3, is an important factor in liver fibrogenesis. Molecular imaging targeting the integrin αvβ3 could provide a non-invasive method for evaluating the expression and the function of the integrin αvβ3 on the activated HSCs (aHSCs) in the injured liver, and then provide important prognostic information. (99m)Tc-3PRGD2 is such a radiotracer specific for integrin αvβ3. In this study, we aimed to compare the differences in liver uptake and retention of the (99m)Tc-3PRGD2 between normal liver and injured liver to evaluate the feasibility of (99m)Tc-3PRGD2 scintigraphy for this purpose. We used planar scintigraphy to assess changes in integrin αvβ3 binding of intravenously-administered (99m)Tc-3PRGD2 in the livers of rats with thioacetamide (TAA)-induced liver fibrosis compared with the controls. We co-injected cold c(RGDyK) with (99m)Tc-3PRGD2 to assess the specific binding of the radiotracer. We performed Sirius red staining to assess liver fibrosis, immunofluorescent colocalization to identify the location of integrin αvβ3 expressed in the fibrotic liver, and we measured protein and messenger RNA expression of integrin αvβ3 and alpha smooth muscle actin (α-SMA) in the control and fibrotic livers. The fibrotic livers showed enhanced (99m)Tc-3PRGD2 uptake and retention. The radiotracer was demonstrated to bind specifically with the integrin αvβ3 mainly expressed on the aHSCs. The liver-to-heart ratio at 30 min post-injection was higher in the fibrotic livers than in the control livers (TAA, 1.98±0.08 vs. control, 1.50±0.12, p<0.01). The liver t1/2 was longer than in the controls (TAA, 27.07±10.69 min vs. control, 12.67±4.10 min, p<0.01). The difference of heart t1/2 between the two groups was not statistically significant (TAA, 3.13±0.63 min vs. control, 3.41±0.77 min, p=0.94). (99m)Tc-3PRGD2 molecular imaging can provide a non-invasive method for

Pregnancy and pentobarbital anaesthesia modify hepatic synthesis of acylglycerol glycerol and glycogen from gluconeogenic precursors during fasting in rats.

PubMed Central

Zorzano, A; Herrera, E

1988-01-01

1. Incorporation of gluconeogenic precursors into blood glucose and hepatic glycogen and acylglycerol glycerol was examined in 24 h-fasted virgin rats by using a flooding procedure for substrate administration. At 10 min after their intravenous injection, the conversion of alanine or glycerol into liver glycogen or acylglycerol glycerol was proportional to glucose synthesis. 2. In 24 h-fasted 21-day-pregnant rats, the incorporation of alanine and glycerol into hepatic acylglycerol glycerol was markedly enhanced compared with the control group. In addition, during fasting at late pregnancy, the proportion of substrates directed to acylglycerol glycerol as compared with the fraction incorporated into glucose was augmented. 3. In pentobarbital-treated fasted rats, the incorporation of both alanine and pyruvate into circulating glucose and into hepatic glycogen and acylglycerol glycerol was increased. Pentobarbital treatment increased the proportion of substrates incorporated into liver glycogen, compared with the fraction appearing in circulating glucose. These changes were concomitant with a marked accumulation of glycogen. 4. The data indicate that, during fasting, gluconeogenesis provides glucose as well as hepatic glycogen and acylglycerol glycerol, independently of whether the substrates enter gluconeogenesis at the level of pyruvate or dihydroxyacetone phosphate. PMID:3223926

Contact-dependent depletion of hydrogen peroxide by catalase is a novel mechanism of myeloid-derived suppressor cell induction operating in human hepatic stellate cells.

PubMed

Resheq, Yazid J; Li, Ka-Kit; Ward, Stephen T; Wilhelm, Annika; Garg, Abhilok; Curbishley, Stuart M; Blahova, Miroslava; Zimmermann, Henning W; Jitschin, Regina; Mougiakakos, Dimitrios; Mackensen, Andreas; Weston, Chris J; Adams, David H

2015-03-15

Myeloid-derived suppressor cells (MDSC) represent a unique cell population with distinct immunosuppressive properties that have been demonstrated to shape the outcome of malignant diseases. Recently, human hepatic stellate cells (HSC) have been reported to induce monocytic-MDSC from mature CD14(+) monocytes in a contact-dependent manner. We now report a novel and unexpected mechanism by which CD14(+)HLADR(low/-) suppressive cells are induced by catalase-mediated depletion of hydrogen peroxide (H2O2). Incubation of CD14(+) monocytes with catalase led to a significant induction of functional MDSC compared with media alone, and H2O2 levels inversely correlated with MDSC frequency (r = -0.6555, p < 0.05). Catalase was detected in primary HSC and a stromal cell line, and addition of the competitive catalase inhibitor hydroxylamine resulted in a dose-dependent impairment of MDSC induction and concomitant increase of H2O2 levels. The NADPH-oxidase subunit gp91 was significantly increased in catalase-induced MDSC as determined by quantitative PCR outlining the importance of oxidative burst for the induction of MDSC. These findings represent a so far unrecognized link between immunosuppression by MDSC and metabolism. Moreover, this mechanism potentially explains how stromal cells can induce a favorable immunological microenvironment in the context of tissue oxidative stress such as occurs during cancer therapy. Copyright © 2015 by The American Association of Immunologists, Inc.

Functional study of miR-27a in human hepatic stellate cells by proteomic analysis: comprehensive view and a role in myogenic tans-differentiation.

PubMed

Ji, Yuhua; Zhang, Jinsheng; Wang, Wenwen; Ji, Juling

2014-01-01

We previous reported that miR-27a regulates lipid metabolism and cell proliferation during hepatic stellate cells (HSCs) activation. To further explore the biological function and underlying mechanisms of miR-27a in HSCs, global protein expression affected by overexpression of miR-27a in HSCs was analyzed by a cleavable isotope-coded affinity tags (cICAT) based comparative proteomic approach. In the present study, 1267 non-redundant proteins were identified with unique accession numbers (score ≥1.3, i.e. confidence ≥95%), among which 1171 were quantified and 149 proteins (12.72%) were differentially expressed with a differential expression ratio of 1.5. We found that up-regulated proteins by miR-27a mainly participate in cell proliferation and myogenesis, while down-regulated proteins were the key enzymes involved in de novo lipid synthesis. The expression of a group of six miR-27a regulated proteins was validated and the function of one miR-27a regulated protein was further validated. The results not only delineated the underlying mechanism of miR-27a in modulating fat metabolism and cell proliferation, but also revealed a novel role of miR-27a in promoting myogenic tans-differentiation during HSCs activation. This study also exemplified proteomics strategy as a powerful tool for the functional study of miRNA.

Long-Term Dexamethasone Exposure Down-Regulates Hepatic TFR1 and Reduces Liver Iron Concentration in Rats

PubMed Central

Li, Huifang; Jiang, Shuxia; Yang, Chun; Yang, Shu; He, Bin; Ma, Wenqiang; Zhao, Ruqian

2017-01-01

Exposure to stress is known to cause hepatic iron dysregulation, but the relationship between prolonged stress and liver iron metabolism is not yet fully understood. Thirty 13-week-old female Sprague–Dawley rats were randomly divided into two groups, as follows: the control group (saline-injection) and the dexamethasone group (Dexamethasone (Dex)-injection 0.1 mg/kg/day). After the 21-day stress trial, the results showed that chronic Dex administration not only impaired serum corticosterone (p = 0.00) and interleukin-6 (IL-6) (p = 0.01) levels, but also decreased white blood cell counts (p = 0.00), and reduced blood lymphocyte counts (p = 0.00). The daily Dex-injection also significantly reduced body weight (p < 0.01) by inhibiting food intake. Consecutive Dex administration resulted in decreased iron intake (p = 0.00), enhanced serum iron levels (p = 0.01), and increased the serum souble transferrin receptor (sTfR) content (p = 0.00) in rats. Meanwhile, long-term Dex exposure down-regulated duodenal cytochrome b (DCYTB) (p = 0.00) and the divalent metal transporter 1 (DMT1) (p = 0.04) protein expression, but up-regulated ferroportin (FPN) protein expression (p = 0.04). Chronic Dex administration reduced liver iron concentration (p = 0.02) in rats. Hepatic transferrin receptor 1 (TFR1) expression was lowered at the protein level (p = 0.03), yet with uncoupled mRNA abundance in Dex-treated rats. Enhanced iron-regulatory protein (IRP)/iron-responsive element (IRE) binding activity was observed, but did not line up with lowered hepatic TFR1 protein expression. This study indicates that long-term Dex exposure reduces liver iron content, which is closely associated with down-regulated hepatic TFR1 protein expression. PMID:28629118

Nutrigenomics analysis reveals that copper deficiency and dietary sucrose up-regulate inflammation, fibrosis and lipogenic pathways in a mature rat model of nonalcoholic fatty liver disease.

PubMed

Tallino, Savannah; Duffy, Megan; Ralle, Martina; Cortés, María Paz; Latorre, Mauricio; Burkhead, Jason L

2015-10-01

Nonalcoholic fatty liver disease (NAFLD) prevalence is increasing worldwide, with the affected US population estimated near 30%. Diet is a recognized risk factor in the NAFLD spectrum, which includes nonalcoholic steatohepatitis (NASH) and fibrosis. Low hepatic copper (Cu) was recently linked to clinical NAFLD/NASH severity. Simple sugar consumption including sucrose and fructose is implicated in NAFLD, while consumption of these macronutrients also decreases liver Cu levels. Though dietary sugar and low Cu are implicated in NAFLD, transcript-level responses that connect diet and pathology are not established. We have developed a mature rat model of NAFLD induced by dietary Cu deficiency, human-relevant high sucrose intake (30% w/w) or both factors in combination. Compared to the control diet with adequate Cu and 10% (w/w) sucrose, rats fed either high-sucrose or low-Cu diet had increased hepatic expression of genes involved in inflammation and fibrogenesis, including hepatic stellate cell activation, while the combination of diet factors also increased ATP citrate lyase and fatty acid synthase gene transcription (fold change > 2, P < 0.02). Low dietary Cu decreased hepatic and serum Cu (P ≤ 0.05), promoted lipid peroxidation and induced NAFLD-like histopathology, while the combined factors also induced fasting hepatic insulin resistance and liver damage. Neither low Cu nor 30% sucrose in the diet led to enhanced weight gain. Taken together, transcript profiles, histological and biochemical data indicate that low Cu and high sucrose promote hepatic gene expression and physiological responses associated with NAFLD and NASH, even in the absence of obesity or severe steatosis. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Immunohistochemistry of connexin 43 throughout anterior pituitary gland in a transgenic rat with green fluorescent protein-expressing folliculo-stellate cells.

PubMed

Horiguchi, Kotaro; Fujiwara, Ken; Kouki, Tom; Kikuchi, Motoshi; Yashiro, Takashi

2008-12-01

Folliculo-stellate (FS) cells in the anterior pituitary gland have been speculated to possess multifunctional properties. Because gap junctions (GJ) have been identified between FS cells, FS cells may be interconnected electrophysiologically by GJ and serve as signal transmission networks to modulate hormone release in the anterior pituitary gland. But whether GJ are localized among FS cells from the pars tuberalis through the pars distalis is unclear. The S100b-GFP transgenic rat has recently been generated, which expresses green fluorescent protein (GFP) specifically in FS cells in the anterior pituitary. This model is expected to be a powerful tool for studies of FS cells. The purpose of the present paper was therefore to examine the localization of GJ on connexin 43 immunohistochemistry throughout the anterior pituitary gland of S100b-GFP rats under confocal laser microscopy. The localization patterns of FS cells was also observed in primary culture of anterior pituitary cells and the question of whether GJ between FS cells are reconstructed in vitro was investigated. In vivo studies showed that GJ were present specifically between FS cells from the pars tuberalis to the pars distalis in the anterior pituitary gland. The appearance of FS cells was distinguished into two types, with localization of GJ differing between types. In vitro, it was observed for the first time that FS cells in primary culture could be categorized into two types. In vivo localization of GJ between FS cells was reconstructed in vitro. These morphological observations are consistent with the hypothesis that FS cells form an electrophysiological network throughout the anterior pituitary for signal transmission.

Hepatic ischemia/reperfusion injury is diminished by atorvastatin in Wistar rats.

PubMed

Cámara-Lemarroy, Carlos Rodrigo; Guzmán-de la Garza, Francisco Javier; Alarcón-Galván, Gabriela; Cordero-Pérez, Paula; Muñoz-Espinosa, Linda; Torres-González, Liliana; Fernández-Garza, Nancy Esthela

2014-04-01

Temporal occlusion of the hepatoduodenal ligament (HDL) is often used during liver surgeries in order to reduce blood loss, resulting in ischemia/reperfusion injury (I/R). The aim of the study was to investigate the effects of atorvastatin (ATOR) on hepatic I/R injury and on serum levels of tumor necrosis factor-alpha (TNF-α), endothelin-1 (ET-1), antithrombin III (ATIII) and intracellular adhesion molecule-1 (ICAM-1). Liver ischemia was induced in Wistar rats by clamping the HDL for 60 min, followed by either 60 or 180 min reperfusion. Rats received either vehicle or 10 mg/kg ATOR before hepatic I/R. Control group received sham surgery. Livers were examined for histological damage and serum AST, ALT, TNF-α, ET-1, ATIII and ICAM-1 concentrations were measured. After I/R, AST and ALT were significantly elevated, ATIII levels were significantly depleted, both TNF-α and ICAM-1 levels increased and ET-1 was significantly elevated (at 180 min). ATOR pretreatment attenuated these alterations and diminished histological injury scores. Our results show that ATOR protects the liver from I/R injury. Copyright © 2014 IMSS. Published by Elsevier Inc. All rights reserved.

Protective effects of Fraxinus xanthoxyloides (Wall.) leaves against CCl4 induced hepatic toxicity in rat.

PubMed

Younis, Tahira; Khan, Muhammad Rashid; Sajid, Moniba

2016-10-24

Leaves and root bark of Fraxinus xanthoxyloides Wall. (Oleaceae) are used locally for the treatment of jaundice, malaria and pneumonia. Decoction of stem, twigs and bark is used in pain, internal injuries, rheumatism and in bone fracture. In this investigation we have evaluated the methanol extract of leaves for its hepatoprotective potential against CCl 4 induced hepatic injuries in rat. Powder of F. xanthoxyloides leaves was extracted with methanol (FXM) and subjected for the determination of polyphenolics through HPLC-DAD analysis. Sprague-Dawley (Rattus novergicus) male rats were divided into eight groups (six rats in each). Group I: non-treated control; Group II: vehicle treated (DMSO plus olive oil) while Group III- VI treated with 1 ml/kg body weight (bw) of CCl 4 (30 % in olive oil) for 30 days (15 dosages) to induce the hepatic injuries. Group IV: treated with silymarin (100 mg/kg bw); Group V and VI with FXM (200, 400 mg/kg bw) on alternate days with CCl 4 treatment. Group VII and VIII was administered with FXM (200, 400 mg/kg bw) alone (15 dosages). After 30 days the serum was evaluated for liver function enzymes and biochemical markers, liver samples for antioxidant enzymes, biochemical markers, comet assay and for histopathology. HPLC-DAD analysis of FXM revealed the existence of rutin and caffeic acid. In CCl 4 treated rats the level of alanine transaminase (ALT), aspartate transaminase (AST), total bilirubin was significantly increased while the albumin concentration in serum was decreased as compared to control group. The level of hepatic antioxidant enzymes, catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), glutathione-S-transferase (GST) and glutathione reductase (GSR) was significantly decreased against the control group. Further, significant decrease in GSH while increase in lipid peroxides (TBARS), H 2 O 2 , DNA damages and comet length was induced with CCl 4 in hepatic tissues of rat. In contrast, co-administration of FXM

Maternal obesity characterized by gestational diabetes increases the susceptibility of rat offspring to hepatic steatosis via a disrupted liver metabolome

PubMed Central

Pereira, Troy J; Fonseca, Mario A; Campbell, Kristyn E; Moyce, Brittany L; Cole, Laura K; Hatch, Grant M; Doucette, Christine A; Klein, Julianne; Aliani, Michel; Dolinsky, Vernon W

2015-01-01

Maternal obesity is associated with a high risk for gestational diabetes mellitus (GDM), which is a common complication of pregnancy. The influence of maternal obesity and GDM on the metabolic health of the offspring is poorly understood. We hypothesize that GDM associated with maternal obesity will cause obesity, insulin resistance and hepatic steatosis in the offspring. Female Sprague-Dawley rats were fed a high-fat (45%) and sucrose (HFS) diet to cause maternal obesity and GDM. Lean control pregnant rats received low-fat (LF; 10%) diets. To investigate the interaction between the prenatal environment and postnatal diets, rat offspring were assigned to LF or HFS diets for 12 weeks, and insulin sensitivity and hepatic steatosis were evaluated. Pregnant GDM dams exhibited excessive gestational weight gain, hyperinsulinaemia and hyperglycaemia. Offspring of GDM dams gained more weight than the offspring of lean dams due to excess adiposity. The offspring of GDM dams also developed hepatic steatosis and insulin resistance. The postnatal consumption of a LF diet did not protect offspring of GDM dams against these metabolic disorders. Analysis of the hepatic metabolome revealed increased diacylglycerol and reduced phosphatidylethanolamine in the offspring of GDM dams compared to offspring of lean dams. Consistent with altered lipid metabolism, the expression of CTP:phosphoethanolamine cytidylyltransferase, and peroxisomal proliferator activated receptor-α mRNA was reduced in the livers of GDM offspring. GDM exposure programs gene expression and hepatic metabolite levels and drives the development of hepatic steatosis and insulin resistance in young adult rat offspring. Key points Gestational diabetes mellitus is a common complication of pregnancy, but its effects on the offspring are poorly understood. We developed a rat model of diet-induced gestational diabetes mellitus that recapitulates many of the clinical features of the disease, including excessive gestational

Hepatic Inflammation and Fibrosis: Functional Links and Key Pathways

PubMed Central

Seki, Ekihiro; Schwabe, Robert F.

2014-01-01

Inflammation is one of the most characteristic features of chronic liver disease of viral, alcoholic, fatty and autoimmune origin. Inflammation is typically present in all disease stages, and associated with the development of fibrosis, cirrhosis and hepatocellular carcinoma. In the past decade, numerous studies have contributed to improved understanding of the links between hepatic inflammation and fibrosis. Here, we review mechanisms that link inflammation with the development of liver fibrosis, focusing on the role of inflammatory mediators in hepatic stellate cell (HSC) activation and HSC survival during fibrogenesis and fibrosis regression. We will summarize the contributions of different inflammatory cells, including hepatic macrophages, T- and B-lymphocytes, NK cells and platelets, as well as key effectors such as cytokines, chemokines, and damage-associated molecular patterns. Furthermore, we will discuss the relevance of inflammatory signaling pathways for clinical liver disease and for the development of anti-fibrogenic strategies. PMID:25066777

Prophylactic action of garlic on the histological and histochemical patterns of hepatic and gastric tissues in rats injected with a snake venom.

PubMed

Rahmy, T R; Hemmaid, K Z

2001-05-01

The present study aimed to examine the prophylactic action of oral administration of two doses of garlic on the histological and histochemical patterns of the gastric and hepatic tissues in rats envenomed with cobra snake. The study included the following groups: Group I contained control rats orally administered distilled water for ten days. Group II included rats orally administered daily for ten days with the equivalent therapeutic dose of garlic to rat (18 mg/kg body weight). Group III included rats orally administered daily for ten days with double the equivalent therapeutic dose of garlic to rat (36 mg/kg body weight). Group IV contained rats intramuscularly (i.m.) injected with 1/2 LD50 of cobra venom (0.0125 microg venom/gm body weight) and dissected after 6 hr from injection. Groups V and VI contained rats daily administered with the previous two doses of garlic for ten days, respectively, followed by a single i.m. injection of the above dose of cobra venom after 24 hr from the last garlic application. Rats of these two groups were dissected after 6 hr from venom injection. Administration of the therapeutic dose of garlic induced slight cytoplasmic granulation in some hepatic cells. However, administration of double the therapeutic dose caused swelling, necrosis, and damage of the gastric glandular epithelia together with signs of erosion, exfoliation, and necrosis of the surface mucosal cells. It also induced swelling and coalescence of the hepatic cells, loss of the normal arrangement of the hepatic cords, and hypertrophy of Kupffer cells. Injection with cobra venom caused loss of the normal characteristic appearance of the gastric glands and the epithelial lining cells of the gastric folds and the appearance of numerous inflammatory cells in the lamina properia. It also induced the occurrence of highly swollen hepatic cells, hepatic cellular necrosis and damage, as well as activated Kupffer cells. Nevertheless, pretreatment with the therapeutic dose of

Nutrigenomics analysis reveals that copper deficiency and dietary sucrose up-regulate inflammation, fibrosis and lipogenic pathways in a mature rat model of non-alcoholic fatty-liver disease

PubMed Central

Tallino, Savannah; Duffy, Megan; Ralle, Martina; Cortés, María Paz; Latorre, Mauricio; Burkhead, Jason L.

2015-01-01

Nonalcoholic fatty-liver disease (NAFLD) prevalence is increasing worldwide, with the affected US population estimated near 30%. Diet is a recognized risk factor in the NAFLD spectrum, which includes non-alcoholic steatohepatitis (NASH) and fibrosis. Low hepatic copper (Cu) was recently linked to clinical NAFLD/NASH severity. Simple sugar consumption including sucrose and fructose is implicated in NAFLD, while consumption of these macronutrients also decrease liver Cu levels. Though dietary sugar and low Cu are implicated in NAFLD, transcript-level responses that connect diet and pathology are not established. We have developed a mature rat model of NAFLD induced by dietary Cu deficiency, human-relevant high sucrose intake (30% w/w), or both factors in combination. Compared to the control diet with adequate Cu and 10% (w/w) sucrose, rats fed either high sucrose or low Cu diets had increased hepatic expression of genes involved in inflammation and fibrogenesis, including hepatic stellate cell activation, while the combination of diet factors also increased ATP citrate lyase (Acly) and fatty-acid synthase (Fasn) gene transcription (Fold change >2, p <0.02). Low dietary Cu decreased hepatic and serum Cu (p ≤0.05), promoted lipid peroxidation, and induced NAFLD-like histopathology, while the combined factors also induced fasting hepatic insulin resistance and liver damage. Neither low Cu nor 30% sucrose in the diet led to enhanced weight gain. Taken together, transcript profiles, histological and biochemical data indicate that low Cu and high sucrose promote hepatic gene expression and physiological responses associated with NAFLD and NASH, even in the absence of obesity or severe steatosis. PMID:26033743

Induction of hepatic and renal ornithine decarboxylase by cobalt and other metal ions in rats.

PubMed Central

Yoshida, T; Numazawa, S; Kuroiwa, Y

1986-01-01

We previously showed that Cd2+ is able to induce hepatic and renal ornithine decarboxylase (ODC). In addition to Cd2+, the administration of Co2+ and other metal ions such as Se2+, Zn2+ and Cr2+ produced a significant increase of hepatic and/or renal ODC activity. Of the metal ions used in this study, Co2+ produced the greatest increase of ODC activity. The maximum increases in hepatic and renal ODC activity, to respectively 70 and 14 times the control values in male rats, were observed 6 h after the administration of Co2+. A similar response was seen in the liver, but not in the kidney, of female rats. Thereafter, ODC activity gradually returned to control values in the liver, but it was profoundly decreased to 7% of the control value at 24 h in the kidney. The pretreatment of animals with either actinomycin D or cycloheximide almost completely blocked the Co2+-mediated increase of ODC activity. Co2+ complexed with either cysteine or glutathione (GSH) failed to induce ODC. Depletion of hepatic GSH content by treatment of rats with diethyl maleate greatly enhanced the inducing effect of Co2+ on ODC. The inhibitors of ODC, 1,3-diaminopropane and alpha-difluoromethylornithine, were able to inhibit the induction of the enzyme, without affecting the induction of haem oxygenase by Co2+. Methylglyoxal bis(guanylhydrazone), an inhibitor of S-adenosylmethionine decarboxylase, significantly inhibited the Co2+-mediated induction of both ODC and haem oxygenase. It is suggested that the inducing effects of Co2+ on ODC and haem oxygenase are brought about in a similar manner. PMID:3754136

Influence of chronic stress on the compositions of hepatic cholesterol and triglyceride in male Wistar rats fed a high fat diet.

PubMed

Gao, Siyuan; Han, Xue; Fu, Jihua; Yuan, Xiaoling; Sun, Xing; Li, Qiang

2012-07-01

  We determined the influence of chronic stress (CS) on the compositions of hepatic cholesterol and triglyceride (TG) in rats fed a high fat diet (HFD).   Male Wistar rats were fed either a standard diet or a HFD and half of the HFD fed rats were given CS (electric foot shock assisted with noise) for 8 weeks.   Compared with the control group, the levels of hepatic total cholesterol (TC) and TG were significantly elevated in the HFD and HFD with chronic stress (HFD+CS) groups, and the more severe elevations of them were found in the HFD group. Inversely, the more severe elevations of hepatic water-soluble parts of TC and TG were found in the HFD+CS group, as the elevations of low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol in liver and serum, tumor necrosis factor-α, interleukin-1β and malondialdehyde in liver. Meanwhile, downregulated mRNA expressions of hepatic liver X receptor-α (LXR-α) and peroxisome proliferator-activated receptor-γ (PPAR-γ) were also more severe in the HFD+CS group.   CS can aggravate the high levels of water-soluble compositions of hepatic TC and TG induced by HFD as it aggravates hepatic inflammation and oxidative stress; in spite of that, however, it cannot further promote hepatic lipidosis. This is consistent with the downregulated mRNA expressions of LXR-α and PPAR-γ. © 2012 The Japan Society of Hepatology.

[Intervention effects of Dan-fang capsule in rats with hepatic fibrosis].

PubMed

Hu, X H; Wu, J; Lu, S

2017-09-19

Objective: To investigate the interventional effect of Dan-fang capsule on liver fibrosis in rats. Methods: Sixty one-week aged male healthy SD rats [weight (180±20) g] were randomly divided into normal control group (group A), hepatic fibrosis model group (group B), Fu-Fang-Bie-Jia-Ruan-Gan tablet group (group C), Dan-fang capsule groups at high, middle and low dose group (group D, E, F, respectively). Except for the normal control group, hepatic fibrosis was induced in other groups by intraperitoneal injection of porcine serum.Simultaneously, rats in Dan-fang capsule groups were administered by gavage with Dan-fang capsule at doses of 4.32, 2.16, 0.54 g/kg, respectively.Rats in Fu-Fang-Bie-Jia-Ruan-Gan tablet group were orally administered by gavage with Fu-Fang-Bie-Jia-Ruan-Gan tablet (0.54 g/kg) every day and the normal control group received saline alone.All rats were killed at the end of the 12th week. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and PⅢnp clia (PⅢNP) were measured in the groups.Pathology changes of hepatic tissue were evaluated by hematoxylin-eosin (HE) and Masson staining.The proteinic expressions of alpha-smooth muscle actin (α-SMA), collagen-Ⅰ (COL-Ⅰ) and collagen-Ⅲ (COL-Ⅲ) were observed with the method of immunohistochemistry.Analysis of variance was applied when data were compared among groups. Results: Compared with those in the group A, the levels of ALT, AST and PⅢNP in serum and the expressions of α-SMA, COL-Ⅰ and COL-Ⅲ in liver tissues were significantly higher in group B [(68.3±3.4) vs (51.5±6.3) U/L, (205±52) vs (135±24) U/L, (3.1±1.4) vs (1.6±0.6) μg/L and 0.35±0.02 vs 0.13±0.02, 0.37±0.02 vs 0.13±0.02, 0.43±0.13 vs 0.13±0.01, t =17.020, 71.053, 1.552, 0.214, 0.241, 0.292, all P <0.01], and the degree of liver fibrosis significantly increased in group B than that in group A. Compared with those in group B, the levels of ALT, AST, PⅢNP and the expressions of α-SMA, COL

HEPATIC METABOLISM OF RETINOIDS AND DISEASE ASSOCIATIONS

PubMed Central

Shirakami, Yohei; Lee, Seung-Ah; Clugston, Robin D.; Blaner, William S.

2012-01-01

The liver is the most important tissue site in the body for uptake of postprandial retinoid, as well as for retinoid storage. Within the liver, both hepatocytes and hepatic stellate cells (HSCs) are importantly involved in retinoid metabolism. Hepatocytes play an indispensable role in uptake and processing of dietary retinoid into the liver, and in synthesis and secretion of retinol-binding protein (RBP), which is required for mobilizing hepatic retinoid stores. HSCs are the central cellular site for retinoid storage in the healthy animal, accounting for as much as 50–60% of the total retinoid present in the entire body. The liver is also an important target organ for retinoid actions. Retinoic acid is synthesized in the liver and can interact with retinoid receptors which control expression of a large number of genes involved in hepatic processes. Altered retinoid metabolism and the accompanying dysregulation of retinoid signaling in the liver contribute to hepatic disease. This is related to HSCs, which contribute significantly to the development of hepatic disease when they undergo a process of cellular activation. HSC activation results in the loss of HSC retinoid stores and changes in extracellular matrix deposition leading to the onset of liver fibrosis. An association between hepatic disease progression and decreased hepatic retinoid storage has been demonstrated. In this review article, we summarize the essential role of the liver in retinoid metabolism and consider briefly associations between hepatic retinoid metabolism and disease. PMID:21763780

Vasodilator-stimulated phosphoprotein promotes activation of hepatic stellate cells by regulating Rab11-dependent plasma membrane targeting of transforming growth factor beta receptors.

PubMed

Tu, Kangsheng; Li, Jiachu; Verma, Vikas K; Liu, Chunsheng; Billadeau, Daniel D; Lamprecht, Georg; Xiang, Xiaoyu; Guo, Luyang; Dhanasekaran, Renumathy; Roberts, Lewis R; Shah, Vijay H; Kang, Ningling

2015-01-01

Liver microenvironment is a critical determinant for development and progression of liver metastasis. Under transforming growth factor beta (TGF-β) stimulation, hepatic stellate cells (HSCs), which are liver-specific pericytes, transdifferentiate into tumor-associated myofibroblasts that promote tumor implantation (TI) and growth in the liver. However, the regulation of this HSC activation process remains poorly understood. In this study, we tested whether vasodilator-stimulated phosphoprotein (VASP) of HSCs regulated the TGF-β-mediated HSC activation process and tumor growth. In both an experimental liver metastasis mouse model and cancer patients, colorectal cancer cells reaching liver sinusoids induced up-regulation of VASP and alpha-smooth muscle actin (α-SMA) in adjacent HSCs. VASP knockdown in HSCs inhibited TGF-β-mediated myofibroblastic activation of HSCs, TI, and growth in mice. Mechanistically, VASP formed protein complexes with TGF-β receptor II (TβRII) and Rab11, a Ras-like small GTPase and key regulator of recycling endosomes. VASP knockdown impaired Rab11 activity and Rab11-dependent targeting of TβRII to the plasma membrane, thereby desensitizing HSCs to TGF-β1 stimulation. Our study demonstrates a requirement of VASP for TGF-β-mediated HSC activation in the tumor microenvironment by regulating Rab11-dependent recycling of TβRII to the plasma membrane. VASP and its effector, Rab11, in the tumor microenvironment thus present therapeutic targets for reducing TI and metastatic growth in the liver. © 2014 by the American Association for the Study of Liver Diseases.

Therapeutic effect of captopril, pentoxifylline, and cordyceps sinensis in pre-hepatic portal hypertensive rats.

PubMed

Ahmed, Ahmed F; El-Maraghy, Nabila N; Abdel Ghaney, Rasha H; Elshazly, Shimaa M

2012-01-01

Portal hypertension is an important and potentially fatal complication of liver disease whereby cellular and fibrotic alterations manifest to increase portal venous pressure. The aim of this study is to investigate the effect of captopril, pentoxifylline (PTX), and cordyceps sinensis in pre-hepatic portal hypertensive rats. Wistar male rats were divided at random into 3 main groups: the first group: control rats. The second group: sham-operated rats and the third group: prehepatic portal hypertensive rats (PHPHT) induced by regulated pre-hepatic portal vein ligation. After 14 days, Group 3 was subdivided into 5 subgroups. Subgroup (1): portal vein-ligated (PVL) was killed at once; Subgroup (2): received distilled water for 30 days (untreated PVL group); subgroups 3-5 were treated with captopril (60 mg/kg, orally); PTX (100 mg/kg, orally); and C. sinensis (200 mg/kg, orally), respectively, as a single daily dose for 30 days. Portal pressure, nitric oxide (NO), antioxidant enzymes, Liver enzymes, and creatinine levels were measured to evaluate the status of the liver state. Portal vein ligation produced significant increments in liver enzymes, NO, creatinine and portal pressure concomitant with significant decrements in glutathione content and superoxide dismutase activity. Treatment with captopril, PTX, and C. sinensis resulted in a significant reduction in liver enzymes, NO, creatinine and portal pressure and observable increase in antioxidant enzymes. captopril, PTX, and C. sinensis have promising effect in controlling PHPHT and reducing hyperdynamic circulatory state through reduction of portal pressure and NO level.

Roux-en-Y Gastric Bypass Improves Hepatic Glucose Metabolism Involving Down-Regulation of Protein Tyrosine Phosphatase 1B in Obese Rats

PubMed Central

Mu, Song; Liu, Jiayu; Guo, Wei; Zhang, Shuping; Xiao, Xiaoqiu; Wang, Zhihong; Zhang, Jun

2017-01-01

Objective This study was initiated to investigate the effects of Roux-en-Y gastric bypass (RYGB) surgery on hepatic glucose metabolism and hepatic expression of protein tyrosine phosphatase 1B (PTP1B) in obese rats. Methods Body weight, glucose, intraperitoneal glucose, insulin, and pyruvate tolerance tests were performed pre- and postoperatively, and plasma lipid, insulin and glucagon-like peptide 1 (GLP-1) were measured. The mRNA levels of G6Pase, Pepck, Gsk-3β and Gys-2, and the expression levels of PTP1B mRNA, protein, and other components of the insulin signaling pathway were measured by using RT-PCR and western blotting. The intracellular localization of PTP1B and hepatic glycogen deposition was also observed. Results RYGB surgery-treated rats showed persistent weight loss, significantly improved glucose tolerance, pyruvate tolerance, and dyslipidemia, as well as increased insulin sensitivity, hepatic glycogen deposition and increased plasma GLP-1 in obese rats. RT-PCR analyses showed Pepck, G6Pase, and Gsk-3β mRNA to be significantly decreased, and Gys-2 mRNA to be significantly increased in liver tissue in the RYGB group (p < 0.05 vs. high-fat diet (HFD) or HFD + sham group); in addition, the expression of PTP1B were significantly decreased and insulin signaling were improved in the RYGB group (p < 0.05 vs. HFD or HFD + sham group). Conclusion RYGB can improve hepatic glucose metabolism and down-regulate PTP1B in obese rats. An increased circulating GLP-1 concentration may be correlated with the effects following RYGB in obese rats. PMID:28564652

Hepatic Concentration and Distribution of Coenzyme A and Carnitine during a Streptococcus pneumoniae Infection in the Rat: Possible Implications on Fatty Acid Metabolism and Ketogenesis

DTIC Science & Technology

1981-01-09

subcellular distribution of carnitine and coenzyme A (CoA). Compared to fasted control ILJ rats, fasted-infected rats have a decreased ketogenic capacity...decreased ketogenic capacity that is associated with an accumulation of total hepatic carnitine and a decrease in total hepatic coenzyme A. The...cholesterol. IiA .Ii INTRODUCTION Rats infected with Streptococcus pneumoniae have a decreased hep-tic ketogenic capacity which is associated with an

HEPATIC GENE EXPRESSION PROFILES OF RATS EXPOSED TO PERFLUOROOCTANE SULFONATE (PFOS) IN UTERO

EPA Science Inventory

Hepatic Gene Expression Profiles of Rats Exposed to Perfluorooctanesulfonate (PFOS) in utero.
J.A. Bjork1, J.M. Berthiaume1, C. Lau2, J. L. Butenhoff3, and K.B. Wallace1

1Department of Biochemistry & Molecular Biology, University of Minnesota School of Medicine, Dulut...

JNK1 induces hedgehog signaling from stellate cells to accelerate liver regeneration in mice.

PubMed

Langiewicz, Magda; Graf, Rolf; Humar, Bostjan; Clavien, Pierre A

2018-04-28

To improve outcomes of two-staged hepatectomies for large/multiple liver tumors, portal vein ligation (PVL) has been combined with parenchymal transection (associating liver partition and portal vein ligation for staged hepatectomy [coined ALPPS]) to greatly accelerate liver regeneration. In a novel ALPPS mouse model, we have reported paracrine Indian hedgehog (IHH) signaling from stellate cells as an early contributor to augmented regeneration. Here, we sought to identify upstream regulators of IHH. ALPPS in mice was compared against PVL and additional control surgeries. Potential IHH regulators were identified through in silico mining of transcriptomic data. c-Jun N-terminal kinase (JNK1 [Mapk8]) activity was reduced through SP600125 to evaluate its effects on IHH signaling. Recombinant IHH was injected after JNK1 diminution to substantiate their relationship during accelerated liver regeneration. Transcriptomic analysis linked Ihh to Mapk8. JNK1 upregulation after ALPPS was validated and preceded the IHH peak. On immunofluorescence, JNK1 and IHH co-localized in alpha-smooth muscle actin-positive non-parenchymal cells. Inhibition of JNK1 prior to ALPPS surgery reduced liver weight gain to PVL levels and was accompanied by downregulation of hepatocellular proliferation and the IHH-GLI1-CCND1 axis. In JNK1-inhibited mice, recombinant IHH restored ALPPS-like acceleration of regeneration and re-elevated JNK1 activity, suggesting the presence of a positive IHH-JNK1 feedback loop. JNK1-mediated induction of IHH paracrine signaling from hepatic stellate cells is essential for accelerated regeneration of parenchymal mass. The JNK1-IHH axis is a mechanism unique to ALPPS surgery and may point to therapeutic alternatives for patients with insufficient regenerative capacity. Associating liver partition and portal vein ligation for staged hepatectomy (so called ALPPS), is a new two-staged approach to hepatectomy, which induces an unprecedented acceleration of liver

Effect of selective versus non-selective cyclooxygenase inhibitors on ischemia-reperfusion-induced hepatic injury in rats.

PubMed

Abdel-Gaber, Seham A; Ibrahim, Mohamed A; Amin, Entesar F; Ibrahim, Salwa A; Mohammed, Rehab K; Abdelrahman, Aly M

2015-08-01

Ischemia-reperfusion (IR) injury represents an important pathological process of liver injury during major hepatic surgery. The role of cyclooxygenase (COX) enzymes in the pathogenesis of ischemia-reperfusion (IR)-induced liver injury is not clear. This study investigated the effect of a selective COX-2 inhibitor, celecoxib, versus non-selective, indomethacin, on hepatic IR injury in rats. Hepatic IR was induced in adult male rats. The animals were divided into 4 groups: normal control (sham group), IR non-treated group; IR-indomethacin-treated group; and IR-celecoxib-treated group. Liver injury was evaluated by serum alanine aminotransferase (ALT) and a histopathological examination of liver tissues. Hepatic tissue content of oxidative stress parameters glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase, malondialdehyde (MDA), nitric oxide (NO) and the inflammatory marker, tumor necrosis factor-alpha, (TNF-α) were measured. Moreover, the immunohistochemical detection of endothelial NO synthase (eNOS), inducible NO synthase (iNOS), and caspase-3 in the hepatic tissue was performed. Celecoxib, but not indomethacin, significantly attenuated hepatic IR injury as evidenced by reduction in serum ALT as well as by improvement in the histopathological scoring. Such effect was associated with attenuation in oxidative stress and TNF-α, along with modulation of immunohistochemical expression of eNOS, iNOS and caspase-3 in the hepatic tissue. The present study concluded that selective COX-2 inhibition (but not non-selective), is hepatoprotective against liver IR injury; indicating a differential role of COX-1 versus COX-2. Modulation of iNOS, eNOS and caspase-3 might participate in the protective effect of selective COX-2-inhibitors. Copyright © 2015 Elsevier Inc. All rights reserved.

Hepatoprotective role of Ricinus communis leaf extract against d-galactosamine induced acute hepatitis in albino rats.

PubMed

Babu, Pappithi Ramesh; Bhuvaneswar, Cherukupalle; Sandeep, Gandham; Ramaiah, Chintha Venkata; Rajendra, Wudayagiri

2017-04-01

Ricinus communis (RC) is a traditional medicinal plant which has been used by Chenchu and Yerukula tribes for treating their liver ailments. The present work is aimed to explore the hepatoprotective efficacy of Ricinus communis against d-galactosamine (D-GalN) induced hepatitis rat model and its therapeutic potential compared with standard drug, silymarin (100mg/kg.bw). In vitro antioxidant activity of Methanolic extract of Ricinus communis leaves (MERCL) was assayed through DPPH and H 2 O 2 free radical scavenging activity. Qualitative and quantitative analysis of MERCL using HPLC, demonstrated that Rutin was found to be predominant bioactive compound in the extract. Hepatitis was induced by treating the rats with D-GalN at a single intraperitoneal dose of 800mg/kg.bw. Serum markers viz, Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), Alkaline phosphatase (ALP) and Malondialdehyde (MDA) levels were significantly increased and the activity levels of antioxidant enzymes such as Superoxide dismutase (SOD),Catalase (CAT), Glutathione reductase (GR), Glutathione peroxidase (GPx), non-enzymatic antioxidant Glutathione (GSH) levels were decreased in the liver of hepatitis induced rats when compared to controls. Pre and post treatment with MERCL significantly altered the enzyme activities, GSH and MDA to normal levels. Histopathological observations also showed protective and curative effects of MERCL against D-GalN intoxication. These results demonstrated that MERCL significantly protected the liver from d-galactosamine induced hepatitis, improved the curative effect in the liver and hence, MERCL can be used as a potent hepatoprotective drug in future. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Genistein modifies liver fibrosis and improves liver function by inducing uPA expression and proteolytic activity in CCl4-treated rats.

PubMed

Salas, Alfonso Leija; Montezuma, Tania Díaz; Fariña, German Garrido; Reyes-Esparza, Jorge; Rodríguez-Fragoso, Lourdes

2008-01-01

To evaluate the effect of genistein on the fibrosis and matrix degradation caused by experimentally induced fibrosis in rats. Hepatic fibrosis was brought about by chronic administration of carbon tetrachloride to rats. To evaluate the effect of genistein on liver fibrosis and function, total collagen content and proteolytic activity in the liver were quantified. Urokinase-type plasminogen activator (uPA) expression during experimental fibrosis was localized by immunohistochemistry. Histopathological changes were evaluated using light and electron microscopy. Animals with fibrosis and treated with genistein showed an important reduction (73%) in hepatic collagen content as well as an improvement in liver function (p < 0.001). Genistein increased the capacity of the liver to degrade type I collagen and Matrigel (3.1- and 3.7-fold, respectively; p < 0.001) in animals with liver fibrosis. Genistein increased the number of uPA-immunoreactive cells. The increase in the uPA expression correlated with an increase in proteolytic activity. Histological analysis revealed a reduction in the number of fiber septa in pericentral and perisinusoidal areas. Transmission electron micrographs of livers from animals with fibrosis and treated with genistein showed a reduction in the number of hepatic stellate cells activated and a smaller number of collagen fibers. Genistein is able to improve the liver after injury and fibrosis induced by chronic administration of carbon tetrachloride. This finding suggests that genistein has antifibrogenic potential and could therefore be useful for treating chronic liver disease. (c) 2008 S. Karger AG, Basel.

Attenuation of CCl4-Induced Hepatic Fibrosis in Mice by Vaccinating against TGF-β1

PubMed Central

Li, Shuang; Lv, Yifei; Su, Houqiang; Jiang, Huiping; Hao, Zhiming

2013-01-01

Transforming growth factor β1 (TGF-β1) is the pivotal pro-fibrogenic cytokine in hepatic fibrosis. Reducing the over-produced expression of TGF-β1 or blocking its signaling pathways is considered to be a promising therapeutic strategy for hepatic fibrosis. In this study, we evaluated the feasibility of attenuating hepatic fibrosis by vaccination against TGF-β1 with TGF-β1 kinoids. Two TGF-β1 kinoid vaccines were prepared by cross-linking TGF-β1-derived polypeptides (TGF-β125–[41-65] and TGF-β130–[83-112]) to keyhole limpet hemocyanin (KLH). Immunization with the two TGF-β1 kinoids efficiently elicited the production of high-levels of TGF-β1-specific antibodies against in BALB/c mice as tested by enzyme-linked immunosorbent assay (ELISA) and Western blotting. The antisera neutralized TGF-β1-induced growth-inhibition on mink lung epithelial cells (Mv1Lu) and attenuated TGF-β1-induced Smad2/3 phosphorylation, α-SMA, collagen type 1 alpha 2 (COL1A2), plasminogen activator inhibitor-1 (PAI-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) expression in the rat hepatic stellate cell (HSC) line, HSC-T6. Vaccination against TGF-β1 with the kinoids significantly suppressed CCl4-induced collagen deposition and the expression of α-SMA and desmin, attenuated hepatocyte apoptosis and accelerated hepatocyte proliferation in BALB/c mice. These results demonstrated that immunization with the TGF-β1 kinoids efficiently attenuated CCl4-induced hepatic fibrosis and liver injury. Our study suggests that vaccination against TGF-β1 might be developed into a feasible therapeutic approach for the treatment of chronic fibrotic liver diseases. PMID:24349218

Ezetimibe improves hepatic steatosis in relation to autophagy in obese and diabetic rats.

PubMed

Chang, Eugene; Kim, Lisa; Park, Se Eun; Rhee, Eun-Jung; Lee, Won-Young; Oh, Ki-Won; Park, Sung-Woo; Park, Cheol-Young

2015-07-07

To investigate whether ezetimibe ameliorates hepatic steatosis and induces autophagy in a rat model of obesity and type 2 diabetes. Male age-matched lean control LETO and obese and diabetic OLETF rats were administered either PBS or ezetimibe (10 mg/kg per day) via stomach gavage for 20 wk. Changes in weight gain and energy intake were regularly monitored. Blood and liver tissue were harvested after overnight fasting at the end of study. Histological assessment was performed in liver tissue. The concentrations of glucose, insulin, triglycerides (TG), free fatty acids (FFA), and total cholesterol (TC) in blood and TG, FFA, and TG in liver tissue were measured. mRNA and protein abundance involved in autophagy was analyzed in the liver. To investigate the effect of ezetimibe on autophagy and reduction in hepatic fat accumulation, human Huh7 hepatocytes were incubated with ezetimibe (10 μmol/L) together with or without palmitic acid (PA, 0.5 mmol/L, 24 h). Transmission electron microscopy (TEM) was employed to demonstrate effect of ezetimibe on autophagy formation. Autophagic flux was measured with bafilomycin A1, an inhibitor of autophagy and following immunoblotting for autophagy-related protein expression. In the OLETF rats that received ezetimibe (10 mg/kg per day), liver weight were significantly decreased by 20% compared to OLETF control rats without changes in food intake and body weight (P < 0.05). Lipid parameters including TG, FFA, and TC in liver tissue of ezetimibe-administrated OLETF rats were dramatically decreased at least by 30% compared to OLETF controls (P < 0.01). The serum glucose, insulin, HOMA-IR, and lipid profiles were also improved by ezetimibe (P < 0.05). In addition, autophagy-related mRNA expression including ATG5, ATG6, and ATG7 and the protein level of microtubule-associated protein light chain 3 (LC3) were significantly increased in the liver in rats that received ezetimibe (P < 0.05). Likewise, for hepatocytes cultured in vitro

Ezetimibe improves hepatic steatosis in relation to autophagy in obese and diabetic rats

PubMed Central

Chang, Eugene; Kim, Lisa; Park, Se Eun; Rhee, Eun-Jung; Lee, Won-Young; Oh, Ki-Won; Park, Sung-Woo; Park, Cheol-Young

2015-01-01

AIM: To investigate whether ezetimibe ameliorates hepatic steatosis and induces autophagy in a rat model of obesity and type 2 diabetes. METHODS: Male age-matched lean control LETO and obese and diabetic OLETF rats were administered either PBS or ezetimibe (10 mg/kg per day) via stomach gavage for 20 wk. Changes in weight gain and energy intake were regularly monitored. Blood and liver tissue were harvested after overnight fasting at the end of study. Histological assessment was performed in liver tissue. The concentrations of glucose, insulin, triglycerides (TG), free fatty acids (FFA), and total cholesterol (TC) in blood and TG, FFA, and TG in liver tissue were measured. mRNA and protein abundance involved in autophagy was analyzed in the liver. To investigate the effect of ezetimibe on autophagy and reduction in hepatic fat accumulation, human Huh7 hepatocytes were incubated with ezetimibe (10 μmol/L) together with or without palmitic acid (PA, 0.5 mmol/L, 24 h). Transmission electron microscopy (TEM) was employed to demonstrate effect of ezetimibe on autophagy formation. Autophagic flux was measured with bafilomycin A1, an inhibitor of autophagy and following immunoblotting for autophagy-related protein expression. RESULTS: In the OLETF rats that received ezetimibe (10 mg/kg per day), liver weight were significantly decreased by 20% compared to OLETF control rats without changes in food intake and body weight (P < 0.05). Lipid parameters including TG, FFA, and TC in liver tissue of ezetimibe-administrated OLETF rats were dramatically decreased at least by 30% compared to OLETF controls (P < 0.01). The serum glucose, insulin, HOMA-IR, and lipid profiles were also improved by ezetimibe (P < 0.05). In addition, autophagy-related mRNA expression including ATG5, ATG6, and ATG7 and the protein level of microtubule-associated protein light chain 3 (LC3) were significantly increased in the liver in rats that received ezetimibe (P < 0.05). Likewise, for hepatocytes

Carvedilol suppresses circulating and hepatic IL-6 responsible for hepatocarcinogenesis of chronically damaged liver in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balaha, Mohamed, E-mail: Mohamed.Balaha@Med.Tanta.

Carvedilol is an anti-oxidant non-selective β-blocker used for reduction of portal blood pressure, prophylaxis of esophageal varices development and bleeding in chronic liver diseases. Recently, it exhibited potent anti-inflammatory, anti-fibrotic, anti-proliferative and anti-carcinogenic effects. In the present study, we evaluated the possible suppressive effect of carvedilol on circulating and hepatic IL-6 levels responsible for hepatocarcinogenesis in a rat model of hepatic cirrhosis. Besides, its effect on hepatic STAT-3 levels, function tests, oxidative stress markers, and hydroxyproline content, hepatic tissue histopathological changes and immunohistochemical expression of E & N-cadherin. Nine-week-old male Wistar rats injected intraperitoneal by 1 ml/kg 10% CCL{sub 4}more » in olive oil three times/week (every other day) for 12 weeks to induce hepatic cirrhosis. Carvedilol (10 mg/kg/day suspended in 0.5% CMC orally), silymarin (50 mg/kg/day suspended in 0.5% CMC orally) or combination of both used to treat hepatic cirrhosis from 15th to 84th day. Our data showed that carvedilol and silymarin co-treatment each alone or in combination efficiently reduced the elevated serum IL-6, ALT, AST, ALP and BIL, hepatic IL-6, STAT-3, MDA levels and hydroxyproline content. In addition, it elevated the reduced serum ALB level, hepatic CAT activity and GSH level. Meanwhile, it apparently restored the normal hepatic architecture, collagen distribution and immunohistochemical E & N-cadherin expression. Furthermore, carvedilol was superior to silymarin in improving MDA level. Moreover, the combination of carvedilol and silymarin showed an upper hand in amelioration of the CCL{sub 4} induced hepatotoxicity than each alone. Therefore, carvedilol could be promising in prevention of hepatocarcinogenesis in chronic hepatic injuries. - Highlights: • Chronic liver damage ends into hepatocellular carcinoma in 5% of patients. • Persistent elevation of IL-6 induces

Effects of age and soybean isoflavones on hepatic cholesterol metabolism and thyroid hormone availability in acyclic female rats.

PubMed

Šošić-Jurjević, Branka; Lütjohann, Dieter; Jarić, Ivana; Miler, Marko; Vojnović Milutinović, Danijela; Filipović, Branko; Ajdžanović, Vladimir; Renko, Kostja; Wirth, Eva Katrin; Janković, Snežana; Kӧhrle, Josef; Milošević, Verica

2017-06-01

Soy-food and its isoflavones, genistein (G) and daidzein (D), were reported to exert mild cholesterol-lowering effect, but the underlying mechanism is still unclear. In this research, first we studied age-related alterations in hepatic cholesterol metabolism of acyclic middle-aged (MA) female rats. Then we tested if purified isoflavones may prevent or reverse these changes, and whether putative changes in hepatic thyroid hormone availability may be associated with this effect. Serum and hepatic total cholesterol (TChol), bile acid and cholesterol precursors, as well as serum TSH and T 4 concentrations, hepatic deiodinase (Dio) 1 enzyme activity and MCT8 protein expression were determined by comparing data obtained for MA with young adult (YA) intact (IC) females. Effects of subcutaneously administered G or D (35mg/kg) to MA rats were evaluated versus vehicle-treated MA females. MA IC females were characterized by: higher (p<0.05) serum TChol, lower (p<0.05) hepatic TChol and its biosynthetic precursors, lower (p<0.05) hepatic 7α-hydroxycholesterol but elevated (p<0.05) 27- and 24-hydroxycholesterol in comparison to YA IC. Both isoflavone treatments decreased (p<0.05) hepatic 27-hydroxycholesterol, G being more effective than D, without affecting any other parameter of Chol metabolism. Only G elevated hepatic Dio1 activity (p<0.05). In conclusion, age-related hypercholesteremia was associated with lower hepatic Chol synthesis and shift from main neutral (lower 7α-hydroxycholesterol) to alternative acidic pathway (higher 27-hydroxycholesterol) of Chol degradation to bile acid. Both isoflavones lowered hepatic 27-hydroxycholesterol, which may be considered beneficial. Only G treatment increased hepatic Dio1 activity, thus indicating local increase in thyroid hormones, obviously insufficient to induce prominent cholesterol-lowering effect. Copyright © 2017 Elsevier Inc. All rights reserved.

Intrinsic electrophysiological properties of entorhinal cortex stellate cells and their contribution to grid cell firing fields

PubMed Central

Pastoll, Hugh; Ramsden, Helen L.; Nolan, Matthew F.

2012-01-01

The medial entorhinal cortex (MEC) is an increasingly important focus for investigation of mechanisms for spatial representation. Grid cells found in layer II of the MEC are likely to be stellate cells, which form a major projection to the dentate gyrus. Entorhinal stellate cells are distinguished by distinct intrinsic electrophysiological properties, but how these properties contribute to representation of space is not yet clear. Here, we review the ionic conductances, synaptic, and excitable properties of stellate cells, and examine their implications for models of grid firing fields. We discuss why existing data are inconsistent with models of grid fields that require stellate cells to generate periodic oscillations. An alternative possibility is that the intrinsic electrophysiological properties of stellate cells are tuned specifically to control integration of synaptic input. We highlight recent evidence that the dorsal-ventral organization of synaptic integration by stellate cells, through differences in currents mediated by HCN and leak potassium channels, influences the corresponding organization of grid fields. Because accurate cellular data will be important for distinguishing mechanisms for generation of grid fields, we introduce new data comparing properties measured with whole-cell and perforated patch-clamp recordings. We find that clustered patterns of action potential firing and the action potential after-hyperpolarization (AHP) are particularly sensitive to recording condition. Nevertheless, with both methods, these properties, resting membrane properties and resonance follow a dorsal-ventral organization. Further investigation of the molecular basis for synaptic integration by stellate cells will be important for understanding mechanisms for generation of grid fields. PMID:22536175

Free radical-triggered hepatic injury of experimental obstructive jaundice of rats involves overproduction of proinflammatory cytokines and enhanced activation of nuclear factor kappaB.

PubMed

Liu, T Z; Lee, K T; Chern, C L; Cheng, J T; Stern, A; Tsai, L Y

2001-10-01

Excessive production of hydroxyl radicals in blood and liver has previously been demonstrated by us in rats with obstructive jaundice induced by common bile duct ligation (CBDL). In this study, we demonstrate overproduction of superoxide radicals in circulating blood of CBDL rats by the lucigenin-amplified chemiluminescence technique. To pinpoint the molecular agents that mediate these processes, we measured circulating proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta ( IL-1beta), and interleukin-6 (IL-6) in controls and CBDL rats. Concentrations of these cytokines in blood of CBDL rats were markedly elevated when compared to the controls (TNF-alpha: 36.7 +/- 5.0 vs 13.8 +/- 0.5 pg/mL; IL-6: 2,814 +/- 1,740 vs 0 pg/mL; IL-1beta: 11.9 +/- 2.6 vs 0 pg/mL). The overproduction of free radicals triggered by elevated cytokines in CBDL rats was correlated with the activation of NF-kappaB in hepatic tissue. Using the TdT-mediated dUTP nick-end label staining technique, we showed that hepatic tissue sections from CBDL rats had an increase in the apoptotic index (AI). Based on these findings, we propose that the severe hepatic injury in CBDL rats is mediated by a cycle that involves the activation of NF-kappaB by combined action of proinflammatory cytokines and reactive oxygen species (ROS). NF-KB, in turn, initiates the transcription of cytokine genes (eg, IL-6, IL-8, TNF-alpha), which triggers hepatic injury, at least in part, by a free radical-mediated apoptotic mechanism. Elevated ROS may be as a positive-feedback signal that triggers NF-KB reactivation; the severe hepatic injury of CBDL rats may result from perpetuation of this vicious cycle.

Effects of hepatic enzyme inducers on thyroxine (T4) catabolism in primary rat hepatocytes

EPA Science Inventory

Nuclear receptor agonists such as phenobarbital (PB), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), and 3-methylcholantrene (3-MC) decrease circulating thyroxine (T4) concentrations in rats. It is suspected that this decrease occurs through the induction of hepatic metabolizing en...

Regulation of hepatic branched-chain alpha-keto acid dehydrogenase kinase in a rat model for type 2 diabetes mellitus at different stages of the disease.

PubMed

Doisaki, Masao; Katano, Yoshiaki; Nakano, Isao; Hirooka, Yoshiki; Itoh, Akihiro; Ishigami, Masatoshi; Hayashi, Kazuhiko; Goto, Hidemi; Fujita, Yuko; Kadota, Yoshihiro; Kitaura, Yasuyuki; Bajotto, Gustavo; Kazama, Shunsuke; Tamura, Tomohiro; Tamura, Noriko; Feng, Guo-Gang; Ishikawa, Naohisa; Shimomura, Yoshiharu

2010-03-05

Branched-chain alpha-keto acid dehydrogenase (BCKDH) kinase (BDK) is responsible for the regulation of BCKDH complex, which is the rate-limiting enzyme in the catabolism of branched-chain amino acids (BCAAs). In the present study, we investigated the expression and activity of hepatic BDK in spontaneous type 2 diabetes using hyperinsulinemic Zucker diabetic fatty rats aged 9weeks and hyperglycemic, but not hyperinsulinemic rats aged 18weeks. The abundance of hepatic BDK mRNA and total BDK protein did not correlate with changes in serum insulin concentrations. On the other hand, the amount of BDK bound to the complex and its kinase activity were correlated with alterations in serum insulin levels, suggesting that hyperinsulinemia upregulates hepatic BDK. The activity of BDK inversely corresponded with the BCKDH complex activity, which was suppressed in hyperinsulinemic rats. These results suggest that insulin regulates BCAA catabolism in type 2 diabetic rats by modulating the hepatic BDK activity. 2010 Elsevier Inc. All rights reserved.

Combined treatment with dipeptidyl peptidase-4 inhibitor (sitagliptin) and angiotensin-II type 1 receptor blocker (losartan) suppresses progression in a non-diabetic rat model of steatohepatitis.

PubMed

Okura, Yasushi; Namisaki, Tadashi; Moriya, Kei; Kitade, Mitsuteru; Takeda, Kosuke; Kaji, Kosuke; Noguchi, Ryuichi; Nishimura, Norihisa; Seki, Kenichiro; Kawaratani, Hideto; Takaya, Hiroaki; Sato, Shinya; Sawada, Yasuhiko; Shimozato, Naotaka; Furukawa, Masanori; Nakanishi, Keisuke; Saikawa, Soichiro; Kubo, Takuya; Asada, Kiyoshi; Yoshiji, Hitoshi

2017-11-01

Dipeptidyl peptidase-4 (DPP4) inhibitors (DPP4-I) are oral glucose-lowering drugs for type 2 diabetes mellitus. Previously, we reported that DPP4-I (sitagliptin) exerted suppressive effects on experimental liver fibrosis in rats. Blockade of the renin-angiotensin system by angiotensin-II type 1 receptor blocker (losartan), commonly used in the management of hypertension, has been shown to significantly alleviate hepatic fibrogenesis and carcinogenesis. We aimed to elucidate the effects and possible mechanisms of a sitagliptin + losartan combination on the progression of non-diabetic non-alcoholic steatohepatitis (NASH) in a rat model. To induce NASH, Fischer 344 rats were fed a choline-deficient L-amino acid-defined diet for 12 weeks. We elucidated the chemopreventive effects of sitagliptin + losartan, especially in conjunction with hepatic stellate cell (HSC) activation, angiogenesis, and oxidative stress, all known to play important roles in the progression of NASH. Sitagliptin + losartan suppressed choline-deficient L-amino acid-defined diet-induced hepatic fibrogenesis and carcinogenesis. The combination treatment exerted a greater inhibitory effect than monotherapy. These inhibitory effects occurred almost concurrently with the suppression of HSC activation, neovascularization, and oxidative stress. In vitro studies showed that sitagliptin + losartan inhibited angiotensin II-induced proliferation and expression of transforming growth factor-β1 and α1 (I)-procollagen mRNA of activated HSC and in vitro angiogenesis, in parallel with the suppression observed in in vivo studies. The widely and safely used sitagliptin + losartan combination treatment in clinical practice could be an effective strategy against NASH. © 2016 The Japan Society of Hepatology.

Treatment with milk thistle extract (Silybum marianum), ursodeoxycholic acid, or their combination attenuates cholestatic liver injury in rats: Role of the hepatic stem cells.

PubMed

Alaca, Nuray; Özbeyli, Dilek; Uslu, Serap; Şahin, Hasan Hüseyin; Yiğittürk, Gürkan; Kurtel, Hızır; Öktem, Gülperi; Çağlayan Yeğen, Berrak

2017-11-01

Cholestasis, which results in hepatic cell death, fibrosis, cirrhosis, and eventually liver failure, is associated with oxidative stress. The aim of this study was to evaluate the effects of milk thistle (MT, Silybum marianum) and ursodeoxycholic acid (UDCA) or their combination on the activation of hepatic stem cells and on the severity of cholestasis liver injury in rats. Under anesthesia, bile ducts of female Sprague Dawley rats were ligated (BDL) or had sham operation. BDL rats were administered saline, UDCA (15 mg/kg/d), MT (600 mg/kg/d), or UDCA+MT by gavage for 10 days. On the 11th day, rats were sacrificed and blood and liver samples were obtained. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatic malondialdehyde (MDA) levels, and myeloperoxidase (MPO) activity were measured. Hepatic injury, a-smooth muscle actin expression, and stem cell markers c-kit, c-Myc, Oct3/4, and SSEA-1 were histologically determined. Histological scores, serum ALT, and hepatic MDA levels were higher in BDL group than in the sham rats, while all treatments significantly reduced these levels. The reduction in ALT was significantly greater in UCDA+MT-treated group than in other treatment groups. c-Kit, c-Myc, Oct3/4, and SSEA-1 were increased in saline-treated BDL group with respect to sham-operated control group, and these markers were significantly reduced in all treatment groups. In addition to a modulatory effect on the stem cell-induced regenerative response of the liver, UDCA, MT, and their combination demonstrated similar anti-inflammatory and antiproliferative effects on cholestasis-induced hepatic injury.

Chronic moderate alcohol consumption relieves high-fat high-cholesterol diet-induced liver fibrosis in a rat model.

PubMed

Sun, Furong; Zhuang, Zhenjie; Zhang, Dai; Chen, Yushuai; Liu, Shu; Gao, Nan; Shi, Junping; Wang, Bingyuan

2018-05-30

Nonalcoholic fatty liver disease is a worldwide health issue and chronic alcohol consumption may have different effects on this disease. This study explored the role of chronic moderate alcohol consumption on high-fat high-cholesterol (HFHC) diet-induced liver fibrosis in a rodent model. Male Sprague-Dawley rats were divided into five groups: standard chow group, standard chow plus Er Guo Tou (EGT, a Chinese spirits made from fermented cereals) group, HFHC group, HFHC plus EGT group, and HFHC plus pure ethanol group. Rats were fed standard chow or HFHC chow for 12 weeks. EGT or pure ethanol was administrated at a daily dose of 4 g/kg body weight via intra-gastric gavage from the week four. At the end of week 12, hematoxylin and eosin staining, Sirius red and immunohistochemistry of liver sections were examined. The hepatic expression of F4/80, TNF-α, IL-1β, IL-6, CXCL1, CXCL2, α-SMA, Collagen, TGF-β, MMP2, MMP9, and TIMP1 was calculated. Both moderate EGT and pure ethanol did not increase plasma endotoxin in the portal vein comparing with the FHFC group. EGT and pure ethanol did not improve hepatic inflammation, but ameliorated liver fibrosis in histology. Moderate EGT and pure ethanol ameliorated HFHC diet-induced activation of Kupffer cells and hepatic stellate cells. In conclusion, chronic moderate EGT and pure ethanol could ameliorate HFHC diet-induced liver fibrosis. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Mechanisms of Action of Acetaldehyde in the Up-Regulation of the Human α2(I) Collagen Gene in Hepatic Stellate Cells

PubMed Central

Reyes-Gordillo, Karina; Shah, Ruchi; Arellanes-Robledo, Jaime; Hernández-Nazara, Zamira; Rincón-Sánchez, Ana Rosa; Inagaki, Yutaka; Rojkind, Marcos; Lakshman, M. Raj

2015-01-01

Alcohol-induced liver fibrosis and eventually cirrhosis is a leading cause of death. Acetaldehyde, the first metabolite of ethanol, up-regulates expression of the human α2(I) collagen gene (COL1A2). Early acetaldehyde-mediated effects involve phosphorylation and nuclear translocation of SMAD3/4–containing complexes that bind to COL1A2 promoter to induce fibrogenesis. We used human and mouse hepatic stellate cells to elucidate the mechanisms whereby acetaldehyde up-regulates COL1A2 by modulating the role of Ski and the expression of SMADs 3, 4, and 7. Acetaldehyde induced up-regulation of COL1A2 by 3.5-fold, with concomitant increases in the mRNA (threefold) and protein (4.2- and 3.5-fold) levels of SMAD3 and SMAD4, respectively. It also caused a 60% decrease in SMAD7 expression. Ski, a member of the Ski/Sno oncogene family, is colocalized in the nucleus with SMAD4. Acetaldehyde induces translocation of Ski and SMAD4 to the cytoplasm, where Ski undergoes proteasomal degradation, as confirmed by the ability of the proteasomal inhibitor lactacystin to blunt up-regulation of acetaldehyde-dependent COL1A2, but not of the nonspecific fibronectin gene (FN1). We conclude that acetaldehyde up-regulates COL1A2 by enhancing expression of the transactivators SMAD3 and SMAD4 while inhibiting the repressor SMAD7, along with promoting Ski translocation from the nucleus to cytoplasm. We speculate that drugs that prevent proteasomal degradation of repressors targeting COL1A2 may have antifibrogenic properties. PMID:24641900

Liver macrophages: friend or foe during hepatitis B infection?

PubMed

Faure-Dupuy, Suzanne; Durantel, David; Lucifora, Julie

2018-05-17

The Hepatitis B virus chronically infects the liver of 250 million people worldwide. Over the past decades, major advances have been made in the understanding of Hepatitis B virus life cycle in hepatocytes. Beside these parenchymal cells, the liver also contains resident and infiltrating myeloid cells involved in immune responses to pathogens and much less is known about their interplay with Hepatitis B virus. In this review, we summarized and discussed the current knowledge of the role of liver macrophages (including Kupffer cells and liver monocyte-derived macrophages), in HBV infection. While it is still unclear if liver macrophages play a role in the establishment and persistence of HBV infection, several studies disclosed data suggesting that HBV would favour liver macrophage anti-inflammatory phenotypes and thereby increase liver tolerance. In addition, alternatively activated liver macrophages might also play in the long term a key role in hepatitis B associated pathogenesis, especially through the activation of hepatic stellate cells. Therapies aiming at a transient activation of pro-inflammatory liver macrophages should therefore be considered for the treatment of chronic HBV infection. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Therapeutic role of niacin in the prevention and regression of hepatic steatosis in rat model of nonalcoholic fatty liver disease.

PubMed

Ganji, Shobha H; Kukes, Gary D; Lambrecht, Nils; Kashyap, Moti L; Kamanna, Vaijinath S

2014-02-15

Nonalcoholic fatty liver disease (NAFLD), a leading cause of liver damage, comprises a spectrum of liver abnormalities including the early fat deposition in the liver (hepatic steatosis) and advanced nonalcoholic steatohepatitis. Niacin decreases plasma triglycerides, but its effect on hepatic steatosis is elusive. To examine the effect of niacin on steatosis, rats were fed either a rodent normal chow, chow containing high fat (HF), or HF containing 0.5% or 1.0% niacin in the diet for 4 wk. For regression studies, rats were first fed the HF diet for 6 wk to induce hepatic steatosis and were then treated with niacin (0.5% in the diet) while on the HF diet for 6 wk. The findings indicated that inclusion of niacin at 0.5% and 1.0% doses in the HF diet significantly decreased liver fat content, liver weight, hepatic oxidative products, and prevented hepatic steatosis. Niacin treatment to rats with preexisting hepatic steatosis induced by the HF diet significantly regressed steatosis. Niacin had no effect on the mRNA expression of fatty acid synthesis or oxidation genes (including sterol-regulatory element-binding protein 1, acetyl-CoA carboxylase 1, fatty acid synthase, and carnitine palmitoyltransferase 1) but significantly inhibited mRNA levels, protein expression, and activity of diacylglycerol acyltrasferase 2, a key enzyme in triglyceride synthesis. These novel findings suggest that niacin effectively prevents and causes the regression of experimental hepatic steatosis. Approved niacin formulation(s) for other indications or niacin analogs may offer a very cost-effective opportunity for the clinical development of niacin for treating NAFLD and fatty liver disease.

The AMPK-v-ATPase-pH axis: A key regulator of the pro-fibrogenic phenotype of human hepatic stellate cells.

PubMed

Marrone, Giusi; De Chiara, Francesco; Böttcher, Katrin; Levi, Ana; Dhar, Dipok; Longato, Lisa; Mazza, Giuseppe; Zhang, Zhenzhen; Marrali, Martina; Iglesias, Anabel Fernández-; Hall, Andrew; Luong, Tu Vinh; Viollet, Benoit; Pinzani, Massimo; Rombouts, Krista

2018-04-17

Liver fibrosis and cirrhosis are characterized by activation of hepatic stellate cells (HSC) which is associated with higher intracellular pH (pHi). The vacuolar H + adenosine-tri-phosphatase (v-ATPase) multi-subunit complex is a key regulator of intracellular pH homeostasis. The present work was aimed at investigating the functional role of v-ATPase in primary human HSC (hHSC) activation and its modulation by specific AMPK subunits. Here, we demonstrated that the expression of different v-ATPase subunits was increased in in vivo and in vitro activated hHSC, compared to non-activated hHSC. Specific inhibition of v-ATPase with Bafilomycin and KM91104 induced a down-regulation of the HSC fibrogenic gene profile, which coincided with increased lysosomal pH, decreased pHi, activation of AMPK, reduced proliferation, and a lower metabolic activity. Similarly, pharmacological activation of AMPK by treatment with Diflunisal, A769662 and ZLN024, reduced the expression of v-ATPase subunits and pro-fibrogenic markers. V-ATPase expression was differently regulated by AMPKα1 and AMPKα2, as demonstrated in mouse embryo fibroblasts (MEF) specific deficient for AMPKα subunits. In addition, the activation of v-ATPase in hHSC was shown to be AMPKα1 dependent. Accordingly, pharmacological activation of AMPK in AMPKα1-depleted hHSC prevented v-ATPase downregulation. Finally, we showed that v-ATPase expression was increased in fibrotic livers from Bile Duct Ligated mice and in human cirrhotic livers. The down-regulation of v-ATPase might represent a new promising target for the development of anti-fibrotic strategies. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

Niemann-Pick Type C2 Protein Regulates Free Cholesterol Accumulation and Influences Hepatic Stellate Cell Proliferation and Mitochondrial Respiration Function.

PubMed

Wang, Yuan-Hsi; Twu, Yuh-Ching; Wang, Chung-Kwe; Lin, Fu-Zhen; Lee, Chun-Ya; Liao, Yi-Jen

2018-06-05

Liver fibrosis is the first step toward the progression to cirrhosis, portal hypertension, and hepatocellular carcinoma. A high-cholesterol diet is associated with liver fibrosis via the accumulation of free cholesterol in hepatic stellate cells (HSCs). Niemann-Pick type C2 (NPC2) plays an important role in the regulation of intracellular free cholesterol homeostasis via direct binding with free cholesterol. Previously, we reported that NPC2 was downregulated in liver cirrhosis tissues. Loss of NPC2 enhanced the accumulation of free cholesterol in HSCs and made them more susceptible to transforming growth factor (TGF)-β1. In this study, we showed that knockdown of NPC2 resulted in marked increases in platelet-derived growth factor BB (PDGF-BB)-induced HSC proliferation through enhanced extracellular signal-regulated kinases (ERK), p38, c-Jun N-terminal kinases (JNK), and protein kinase B (AKT) phosphorylation. In contrast, NPC2 overexpression decreased PDGF-BB-induced cell proliferation by inhibiting p38, JNK, and AKT phosphorylation. Although NPC2 expression did not affect caspase-related apoptosis, the autophagy marker light chain 3β (LC3B) was decreased in NPC2 knockdown, and free cholesterol accumulated in the HSCs. The mitochondrial respiration functions (such as oxygen consumption rate, ATP production, and maximal respiratory capacity) were decreased in NPC2 knockdown, and free cholesterol accumulated in the HSCs, while NPC2-overexpressed cells remained normal. In addition, NPC2 expression did not affect the susceptibility of HSCs to lipopolysaccharides (LPS), and U18666A treatment induced free cholesterol accumulation, which enhanced LPS-induced Toll-like receptor 4 (TLR4), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 phosphorylation, interleukin (IL)-1 and IL-6 expression. Our study demonstrated that NPC2-mediated free cholesterol homeostasis controls HSC proliferation and mitochondrial function.

Soy compared with milk protein in a western diet changes fecal microbiota and decreases hepatic steatosis in obese OLETF rats

USDA-ARS?s Scientific Manuscript database

Soy protein is effective at preventing hepatic steatosis; however, the mechanisms are poorly understood. We tested the hypothesis that soy versus dairy protein-based diet would alter microbiota and attenuate hepatic steatosis in hyperphagic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Male OLETF ...

The ameliorative effect of thymol against hydrocortisone-induced hepatic oxidative stress injury in adult male rats.

PubMed

Aboelwafa, Hanaa R; Yousef, Hany N

2015-08-01

The aim of the present study was to investigate whether hydrocortisone induces oxidative stress in hepatocytes and to evaluate the possible ameliorative effect of thymol against such hepatic injury. Twenty-four adult male rats were divided into control, thymol, hydrocortisone, and hydrocortisone+thymol groups. The 4 groups were treated daily for 15 days. Hydrocortisone significantly induced oxidative stress in the liver tissues, marked by increased serum levels of alanine transaminase (ALT), aspartate transaminase (AST), total oxidative capacity (TOC), and tumor necrosis factor-alpha (TNF-α) accompanied by marked decline of serum levels of total protein, albumin, and total antioxidant capacity (TAC). Also, marked elevation in the levels of the thiobarbituric acid reactive substances (TBARS) and TNF-α, beside significant decrease in the level of glutathione (GSH) in hepatic tissues were recorded. These biochemical alterations were accompanied by histopathological changes marked by destruction of the normal hepatic architecture, in addition to ultrastructural alterations represented by degenerative features covering almost all the cytoplasmic organelles of the hepatocytes. Supplementation of hydrocortisone-treated rats with thymol reversed most of the biochemical, histological, and ultrastructural alterations. The results of our study confirm that thymol has strong ameliorative effect against hydrocortisone-induced oxidative stress injury in hepatic tissues.

Recovery of hepatic clearance and extraction following a release of common bile duct obstruction in the rat.

PubMed

Melzer, E; Krepel, Z; Ronen, I; Bar-Meir, S

1992-01-01

The rate of recovery for hepatic clearance and extraction following release of common-duct obstruction was investigated in the rat. Male Wistar rats underwent ligation of a cannulated common bile duct. Two weeks later, the cannula was opened and implanted into the duodenum, thus re-establishing enterohepatic circulation. Hepatic extraction and indocyanine green clearance were determined in three groups of six rats each, which differed by the time elapsed from the re-establishment of communication between the common bile duct and duodenum, i.e., 1, 48 and 168 h, respectively. A fourth group, in which a sham operation was performed, served as a control. Clearance was reduced from 16.9 +/- 2.5 ml/min per kg in the control group to 2.9 +/- 0.8, 5.4 +/- 2.4, and 8.5 +/- 3.3 ml/min per kg 1, 48, and 168 h, respectively, after release of common-bile-duct obstruction. Extraction rate was reduced from 37.3 +/- 5.9% to 17.5 +/- 2.7% in the 1st hour and recovered completely at 1 week. Thus, in the rat, release of a 2-week common-bile-duct obstruction is associated with complete recovery of the extraction capacity of the liver within a week, but only incomplete recovery of clearance. This decrease in clearance seems to be due to a decrease in effective hepatic blood flow, mostly probably due to the development of porto-systemic shunts.

Rat hepatitis E virus: geographical clustering within Germany and serological detection in wild Norway rats (Rattus norvegicus).

PubMed

Johne, Reimar; Dremsek, Paul; Kindler, Eveline; Schielke, Anika; Plenge-Bönig, Anita; Gregersen, Henrike; Wessels, Ute; Schmidt, Katja; Rietschel, Wolfram; Groschup, Martin H; Guenther, Sebastian; Heckel, Gerald; Ulrich, Rainer G

2012-07-01

Zoonotic hepatitis E virus (HEV) infection in industrialised countries is thought to be caused by transmission from wild boar, domestic pig and deer as reservoir hosts. The detection of HEV-specific antibodies in rats and other rodents has suggested that these animals may represent an additional source for HEV transmission to human. Recently, a novel HEV (ratHEV) was detected in Norway rats from Hamburg, Germany, showing the typical genome organisation but a high nucleotide and amino acid sequence divergence to other mammalian and to avian HEV strains. Here we describe the multiple detection of ratHEV RNA and HEV-specific antibodies in Norway rats from additional cities in north-east and south-west Germany. The complete genome analysis of two novel strains from Berlin and Stuttgart confirmed the association of ratHEV to Norway rats. The present data indicated a continuing existence of this virus in the rat populations from Berlin and Hamburg. The phylogenetic analysis of a short segment of the open reading frame 1 confirmed a geographical clustering of the corresponding sequences. Serological investigations using recombinant ratHEV and genotype 3 capsid protein derivatives demonstrated antigenic differences which might be caused by the high amino acid sequence divergence in the immunodominant region. The high amount of animals showing exclusively ratHEV RNA or anti-ratHEV antibodies suggested a non-persistent infection in the Norway rat. Future studies have to prove the transmission routes of the virus in rat populations and its zoonotic potential. The recombinant ratHEV antigen generated here will allow future seroepidemiological studies to differentiate ratHEV and genotype 3 infections in humans and animals. Copyright © 2012 Elsevier B.V. All rights reserved.

Surgical anatomy of the liver, hepatic vasculature and bile ducts in the rat.

PubMed

Martins, Paulo Ney Aguiar; Neuhaus, Peter

2007-04-01

The rat is the most used experimental model in surgical research. Virtually all procedures in clinical liver surgery can be performed in the rat. However, the use of the rat model in liver surgery is limited by its small size and limited knowledge of the liver anatomy. As in humans, the rat liver vasculature and biliary system have many anatomical variations. The development of surgical techniques, and the study of liver function and diseases require detailed knowledge of the regional anatomy. The objective of this study was to describe and illustrate systematically the surgical anatomy of the rat liver to facilitate the planning and performance of studies in this animal. Knowledge of the diameter and length of liver vessels is also important for the selection of catheters and perivascular devices. Twelve Wistar rat livers were dissected using a surgical microscope. Hepatic and extrahepatic anatomical structures were measured under magnification with a millimeter scale. In this study, we describe the rat liver topographical anatomy, compare it with the human liver and review the literature. Increased knowledge of the rat liver anatomy and microsurgical skills permit individualized dissection, parenchymal section, embolization and ligature of vascular and biliary branches.

Therapeutic Effect of Captopril, Pentoxifylline, and Cordyceps Sinensis in Pre-Hepatic Portal Hypertensive Rats

PubMed Central

Ahmed, Ahmed F.; El-Maraghy, Nabila N.; Ghaney, Rasha H. Abdel; Elshazly, Shimaa M.

2012-01-01

Background/Aim: Portal hypertension is an important and potentially fatal complication of liver disease whereby cellular and fibrotic alterations manifest to increase portal venous pressure. The aim of this study is to investigate the effect of captopril, pentoxifylline (PTX), and cordyceps sinensis in pre-hepatic portal hypertensive rats. Settings and Design: Wister male rats were divided at random into 3 main groups: the first group: control rats. The second group: sham-operated rats and the third group: prehepatic portal hypertensive rats (PHPHT) induced by regulated pre-hepatic portal vein ligation. After 14 days, Group 3 was subdivided into 5 subgroups. Subgroup (1): portal vein-ligated (PVL) was killed at once; Subgroup (2): received distilled water for 30 days (untreated PVL group); subgroups 3-5 were treated with captopril (60 mg/kg, orally); PTX (100 mg/kg, orally); and C. sinensis (200 mg/kg, orally), respectively, as a single daily dose for 30 days. Patients and Methods: Portal pressure, nitric oxide (NO), antioxidant enzymes, Liver enzymes, and creatinine levels were measured to evaluate the status of the liver state. Results: Portal vein ligation produced significant increments in liver enzymes, NO, creatinine and portal pressure concomitant with significant decrements in glutathione content and superoxide dismutase activity. Treatment with captopril, PTX, and C. sinensis resulted in a significant reduction in liver enzymes, NO, creatinine and portal pressure and observable increase in antioxidant enzymes. Conclusions: captopril, PTX, and C. sinensis have promising effect in controlling PHPHT and reducing hyperdynamic circulatory state through reduction of portal pressure and NO level. PMID:22626797

Altered pharmacokinetics and pharmacodynamics of repaglinide by ritonavir in rats with healthy, diabetic and impaired hepatic function.

PubMed

Goud, Thirumaleswara; Maddi, Srinivas; Nayakanti, Devanna; Thatipamula, Rajendra Prasad

2016-06-01

Ritonavir is an antiretroviral drug to treat HIV AIDS and inhibits cytochrome P450 3A4. To treat diabetes mellitus in HIV, repaglinide is coadministered with ritonavir in the clinic. Multiple cytochrome P450 (CYP) isoforms are involved in the metabolism of repaglinide like CYP2C8 and CYP 3A4. In order to predict and understand drug-drug interactions of these two drugs, the pharmacokinetics and pharmacodynamics (PK/PD) of repaglinide and ritonavir were studied in normal, diabetic and hepatic impaired rats. The purpose of the study was to assess the influence of ritonavir on the PK/PD of repaglinide in rats with normal, diabetic and impaired hepatic function. Human oral therapeutic doses of ritonavir and repaglinide were extrapolated to rats based on the body surface area. Ritonavir (20 mg/kg, p.o.), alone and along with repaglinide (0.5 mg/kg, p.o.), was given to normal, diabetic and hepatic impaired rats, and the PK/PD were studied. The pharmacokinetic parameters like peak plasma concentration (Cmax), area under the plasma concentration time profile (AUC) and elimination half life of repaglinide were significantly (p<0.0001) increased when compared to repaglinide control rats. The repaglinide clearance (CL) was significantly (p<0.0001) decreased in the presence of ritonavir treatment. In the presence of ritonavir, repaglinide hypoglycemic activity was increased significantly (p<0.0005) when compared with repaglinide control group. The significant difference in the PK/PD changes have been due to the increased plasma exposure and decreased total body clearance of repaglinide, which may be due to the inhibition of the CYP P450 metabolic system and organic anion-transporting polypeptide transporter by ritonavir.

Ischemic Preconditioning Produces Comparable Protection Against Hepatic Ischemia/Reperfusion Injury Under Isoflurane and Sevoflurane Anesthesia in Rats.

PubMed

Jeong, J S; Kim, D; Kim, K Y; Ryu, S; Han, S; Shin, B S; Kim, G S; Gwak, M S; Ko, J S

2017-11-01

Various volatile anesthetics and ischemic preconditioning (IP) have been demonstrated to exert protective effect against ischemia/reperfusion (I/R) injury in liver. We aimed to determine whether application of IP under isoflurane and sevoflurane anesthesia would confer protection against hepatic I/R injury in rats. Thirty-eight rats weighing 270 to 300 grams were randomly divided into 2 groups: isoflurane (1.5%) and sevoflurane (2.5%) anesthesia groups. Each group was subdivided into sham (n = 3), non-IP (n = 8; 45 minutes of hepatic ischemia), and IP (n = 8, IP consisting of 10-minute ischemia plus 15-minute reperfusion before prolonged ischemia) groups. The degree of hepatic injury and expressions of B-cell lymphoma 2 (Bcl-2) and caspase 3 were compared at 2 hours after reperfusion. Hepatic ischemia induced significant degree of I/R injuries in both isoflurane and sevoflurane non-IP groups. In both anesthetic groups, introduction of IP dramatically attenuated I/R injuries as marked by significantly lower aspartate aminotransferase and aminotransferase levels and better histologic grades compared with corresponding non-IP groups. There were 2.3- and 1.7-fold increases in Bcl-2 mRNA levels in isoflurane and sevoflurane IP groups, respectively, compared with corresponding non-IP groups (both P < .05). Caspase 3 level was significantly high in the isoflurane non-IP group compared with the sham group; however, there were no differences among the sevoflurane groups. The degree of hepatic I/R injury was significantly high in both isoflurane and sevoflurane groups in rats. However, application of IP significantly protected against I/R injury in both volatile anesthetic groups to similar degrees, and upregulation of Bcl-2 might be an important mechanism. Copyright © 2017 Elsevier Inc. All rights reserved.

Apocynin prevented inflammation and oxidative stress in carbon tetra chloride induced hepatic dysfunction in rats.

PubMed

Rahman, Md Mizanur; Muse, Awale Yousuf; Khan, D M Isha Olive; Ahmed, Ismaile Hussein; Subhan, Nusrat; Reza, Hasan Mahmud; Alam, Md Ashraful; Nahar, Lutfun; Sarker, Satyajit Dey

2017-08-01

Liver fibrosis is a leading pathway to cirrhosis and a global clinical issue. Oxidative stress mediated tissue damage is one of the prime causes of hepatic dysfunction and fibrosis. Apocynin is one of many strong antioxidants. To evaluate the effect of apocynin in the CCl 4 administered hepatic dysfunction in rats. Female Long Evans rats were administered with CCl 4 orally (1mL/kg) twice a week for 2 weeks and were treated with apocynin (100mg/kg). Both plasma and liver tissues were analyzed for alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase activities. Oxidative stress parameters were also measured by determining malondialdehyde (MDA), nitric oxide (NO), myeloperoxidase (MPO), advanced protein oxidation product (APOP). In addition, antioxidant enzyme activities such as superoxide dismutase (SOD) and catalase activities in plasma and liver tissues were analyzed. Moreover, inflammation and tissue fibrosis were confirmed by histological staining of liver tissue sections. Apocynin significantly reduced serum AST, ALT, and ALP activities in carbon tetrachloride treated rats. It also exhibited a considerable reduction of the oxidative stress markers (MDA, MPO, NO, and APOP level) which was elevated due to CCl 4 administration in rats. Apocynin treatment also restored the catalase and superoxide dismutase activity in CCl 4 treated rats. Histological analysis of liver sections revealed that apocynin prevented inflammatory cells infiltration and fibrosis in CCl 4 administered rats. These results suggest that apocynin protects liver damage induced by CCl 4 by inhibiting lipid peroxidation and stimulating the cellular antioxidant system. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Increased binding of LDL and VLDL to apo B,E receptors of hepatic plasma membrane of rats treated with Fibernat.

PubMed

Venkatesan, Nandini; Devaraj, S Niranjali; Devaraj, H

2003-10-01

Research has focussed on the hypocholesterolemic effects of certain types of dietary fiber such as enhancing conversion of hepatic cholesterol to bile acids or increase in catabolism of low density lipoprotein (LDL) via the apo B,E receptor. The effect of oral administration of a unique fibre cocktail of fenugreek seed powder, guar gum and wheat bran (Fibernat) and its varied effects on some aspects of lipid metabolism and cholesterol homeostasis in rats were examined. Rats were administered Fibernat along with the atherogenic diet containing 1.5 % cholesterol and 0.1 % cholic acid. Amounts of hepatic lipids, hepatic and fecal bile acids and activity of hepatic triglyceride lipase (HTGL) were determined. Transmission electron microscopic examination of the liver tissue and extent of uptake of (125)I-LDL and (125)I-VLDL by the hepatic apo B,E receptor was carried out. Food intake and body weight gain were similar between the 3 different dietary groups. Fibernat intake significantly increased apo B,E receptor expression in rat liver as reflected by an increase in the maximum binding capacity (B(max)) of the apo B,E receptor to (125)I-LDL and (125)I-VLDL. The activity of HTGL was increased by approximately 1.5-fold in Fibernat-fed rats as compared to those fed the atherogenic diet alone. A marked hypocholesterolemic effect was observed. Cholesterol homeostasis was achieved in Fibernat-fed rats. Two possible mechanisms are postulated to be responsible for the observed hypocholesterolemic effect a) an increase in conversion of cholesterol to bile acids and b) possibly by intra-luminal binding which resulted in increased fecal excretion of bile acids and neutral sterols. The resulting reduction in cholesterol content of liver cells coupled with upregulation of hepatic apo B,E receptors and increased clearance of circulating atherogenic lipoproteins-LDL and very low density lipoprotein (LDL and VLDL)-is the main mechanism involved in the hypocholesterolemic effect of

[Protective effect of Tanreqing injection on acute hepatic injury induced by CCl4 in rats].

PubMed

Lei, Yang; Zhou, Ai-Min; Guo, Tao; Tan, Ye; Tao, Yan-Yan; Liu, Cheng-Hai

2013-04-01

To observe the protective effect of Tanreqing injection(TRQ) on carbon tetrachloride-induced acute hepatic injury in rats. Rats were randomly divided into the normal group and the model group, and injected subcutaneously with 100% CCl4 5 mL x kg(-1) to establish the single CCl4 infection model, in order to observe the changes in rat liver injury after 3 h and 6 h. Subsequently, the multiple CCl4 infection liver injury model was reproduced by subcutaneously injecting 100% CCl4 (5 mL x kg(-1)), 50% CCl4 olive oil solution (2 mL x kg(-1)) and then 20% CCl4 olive oil solution (2 mL x kg(-1)). At 6 h after the first CCl4 injection, the rats were divided into six groups: the model group, the control group, the diammonium glycyrrhizinate-treated group, and TRQ high, middle and low dose groups. They were injected through caudal veins, while a normal control group was set up. Their weight and liver-body ratio were observed. Hepatic inflammation was observed with HE staining. Assay kits were adopted to detect ALT, AST, T. Bil, D. Bil, CHE, TBA, gamma-GT and Alb. According to the single injection model, serum AST and T. Bil of model rats were obviously increased at 6 h after single subcutaneous injection of CCl4, with disordered lobular structure in liver tissues, notable swollen liver cells and remarkable liver injury. According to the results of the multiple injection pharmacological experiment, compared with the normal group, the model group had higher serum ALT, AST, and gamma-GT activities (P < 0. 05), TBA and T. Bil contents (P < 0.05) and lower CHE activity (P < 0.05). HE staining showed disorganized lobular structure in liver tissues and notable ballooning degeneration in liver cells. Compared with the model group, TRQ high and middle dose groups and the diammonium glycyrrhizinate-treated group showed significant charges in serum liver function and inflammation in liver cells. Specifically, TRQ high and middle dose groups were superior to the diammonium

Vinpocetine ameliorates acute hepatic damage caused by administration of carbon tetrachloride in rats.

PubMed

Abdel Salam, O M E; Oraby, Fatma Hassan; Hassan, Nabila S

2007-12-01

Vinpocetine is a widely used drug for the treatment of cerebrovascular and memory disorders. This study aimed to investigate the effect of vinpocetine on the acute hepatic injury caused in the rat by the administration of CCl4 in vivo. Vinpocetine (2.1, 4.2, 8.4 mg/kg) or silymarin (30 mg/kg) was given once daily orally simultaneously with CCl4 and for 15 days thereafter. Liver damage was assessed by determining serum enzyme activities and hepatic histopathology. Stained sections were subjected to morphometric evaluation using computerized image analyzer. The results showed that vinpocetine administered to CCl4-treated rats decreased the elevated alanine aminotransferase (ALT) by 49.3, 58.1 and 63.6%, aspartate aminotransferase (AST) by 10.5, 22.6 and 27.2% and alkaline phosphatase (ALP) by 52.5, 59.6 and 64.9%, respectively, and in a dose-dependent manner. Meanwhile, silymarin reduced elevated ALT, AST and ALP levels by 53.1, 26.9 and 66%, respectively. Histological examination of liver specimens revealed a marked reduction in liver cell necrosis in vinpocetine and silymarin-treated rats compared with vehicle-treated CCl4-treated rats. Quantitative analysis of the area of damage showed 85.3% reduction in the area of damage after silymarin and 72.2, 78.9 and 82.6% reduction after vinpocetine treatment at 2.1, 4.2, 8.4 mg/kg, respectively. It is concluded that administration of vinpocetine in a model of CCl4-induced liver injury in rats reduced liver damage. The reduction obtained by 4.2 mg/kg of vinpocetine was similar to that obtained by 30 mg/kg silymarin. Therefore, it is suggested that vinpocetine might be a good pharmacological agent in the treatment of liver disease besides its neuroprotective effects.

The enhanced atorvastatin hepatotoxicity in diabetic rats was partly attributed to the upregulated hepatic Cyp3a and SLCO1B1

PubMed Central

Shu, Nan; Hu, Mengyue; Ling, Zhaoli; Liu, Peihua; Wang, Fan; Xu, Ping; Zhong, Zeyu; Sun, Binbin; Zhang, Mian; Li, Feng; Xie, Qiushi; Liu, Xiaodong; Liu, Li

2016-01-01

Liver injury is a common adverse effect of atorvastatin. This study aimed to investigate atorvastatin-induced hepatotoxicity in diabetic rats induced by high-fat diet combined with streptozotocin. The results showed that 40 mg/kg atorvastatin was lethal to diabetic rats, whose mean survival time was 6.2 days. Severe liver injury also occurred in diabetic rats treated with 10 mg/kg and 20 mg/kg atorvastatin. The in vitro results indicated that atorvastatin cytotoxicity in hepatocytes of diabetic rats was more severe than normal and high-fat diet feeding rats. Expressions and activities of hepatic Cyp3a and SLCO1B1 were increased in diabetic rats, which were highly correlated with hepatotoxicity. Antioxidants (glutathione and N-Acetylcysteine), Cyp3a inhibitor ketoconazole and SLCO1B1 inhibitor gemfibrozil suppressed cytotoxicity and ROS formation in primary hepatocytes of diabetic rats. In HepG2 cells, up-regulations of CYP3A4 and SLCO1B1 potentiated hepatotoxicity and ROS generation, whereas knockdowns of CYP3A4 and SLCO1B1 as well as CYP3A4/SLCO1B1 inhibitions showed the opposite effects. Phenobarbital pretreatment was used to induce hepatic Cyp3a and SLCO1B1 in rats. Phenobarbital aggravated atorvastatin-induced hepatotoxicity, while decreased plasma exposure of atorvastatin. All these findings demonstrated that the upregulations of hepatic Cyp3a and SLCO1B1 in diabetic rats potentiated atorvastatin-induced hepatotoxicity via increasing ROS formation. PMID:27624558

Hepatoprotective effects of naturally fermented noni juice against thioacetamide-induced liver fibrosis in rats.

PubMed

Lin, Yi-Ling; Lin, Hui-Wen; Chen, Yi-Chen; Yang, Deng-Jye; Li, Chien-Chun; Chang, Yuan-Yen

2017-04-01

Excessive reactive oxygen species (ROS) can result in inflammation and cytokine secretion in the liver, and then activate hepatic stellate cells that cause the accumulation of extracellular matrix proteins, especially collagen, in liver tissue. Naturally fermented noni juice (NJ; Morinda citrifolia) has been used for decades as a nutraceutical in humans. In this study, we intended to examine if NJ can ameliorate ROS-induced liver fibrosis via a thioacetamide (TAA)-induced rat model. The 50 rats used in this study were separated into five groups of 10 rats each for 8 weeks as follows: (1) control group; (2) TAA; (3) TAA+low-dose NJ (2.51 mL NJ/kg); (4) TAA+medium-dose NJ (5.02 mL NJ/kg); and (5) TAA+high-dose NJ (7.52 mL NJ/kg). Treatment with TAA resulted in lower body weight and serum lipid levels (p<0.05), while liver weight and collagen contents, and serum alanine aminotransferase and aspartate aminotransferase values were increased (p<0.05). The protective effects of NJ on TAA treatment resulted from decreased endoplasmic reticulum stress-related gene expressions (p<0.05), inflammatory cytokines, collagen accumulation, and matrix metalloproteinase (MMP-2 and MMP-9) activities, as well as upregulated (p<0.05) tissue inhibitors of metalloproteinase (TIMP-1 and TIMP-3) in livers. NJ also increased hepatic antioxidant capacities (p<0.05). Naturally fermented NJ manifests a protective potential on liver fibrosis via the enhancement of antioxidant capacities, as well as decreasing endoplasmic-reticulum stress and MMP-2/MMP-9 activities. Copyright © 2017. Published by Elsevier Taiwan LLC.

PPARα/γ antagonists reverse the ameliorative effects of osthole on hepatic lipid metabolism and inflammatory response in steatohepatitic rats.

PubMed

Zhao, Xi; Wang, Feng; Zhou, Ruijun; Zhu, Zengyan; Xie, Meilin

2018-04-01

Our previous studies have indicated that osthole may ameliorate the hepatic lipid metabolism and inflammatory response in nonalcoholic steatohepatitic rats, but the underlying mechanisms remain unclear. This study aimed to determine whether the effects of osthole were mediated by the activation of hepatic peroxisome proliferator-activated receptor α/γ (PPARα/γ). A rat model with steatohepatitis was induced by orally feeding high-fat and high-sucrose emulsion for 6 weeks. These experimental rats were then treated with osthole (20 mg/kg), PPARα antagonist MK886 (1 mg/kg) plus osthole (20 mg/kg), PPARγ antagonist GW9662 (1 mg/kg) plus osthole (20 mg/kg) and MK886 (1 mg/kg) plus GW9662 (1 mg/kg) plus osthole (20 mg/kg) for 4 weeks. The results showed that after osthole treatment, the hepatic triglycerides, free fatty acids, tumor necrosis factor-α, monocyte chemotactic protein-1, interleukin-6 (IL-6), IL-8 and liver index decreased by 52.3, 31.0, 32.4, 28.9, 36.3, 29.3 and 29.9%, respectively, and the score of steatohepatitis also decreased by 70.0%, indicating that osthole improved the hepatic steatosis and inflammation. However, these effects of osthole were reduced or abrogated after simultaneous addition of the specific PPARα antagonist MK886 or/and the PPARγ antagonist GW9662, especially in the co-PPARα/γ antagonists-treated group. Importantly, the osthole-induced hepatic expressions of PPARα/γ proteins were decreased, and the osthole-regulated hepatic expressions of lipogenic and inflammatory gene proteins were also reversed by PPARα/γ antagonist treatment. These findings demonstrated that the ameliorative effect of osthole on nonalcoholic steatohepatitis was mediated by PPARα/γ activation, and osthole might be a natural dual PPARα/γ activator.

Effects of dietary inulin, statin, and their co-treatment on hyperlipidemia, hepatic steatosis and changes in drug-metabolizing enzymes in rats fed a high-fat and high-sucrose diet

PubMed Central

2012-01-01

Background Rats fed a high-fat and high-sucrose (HF) diet develop hepatic steatosis and hyperlipidemia. There are several reports that a change in nutritional status affects hepatic levels of drug-metabolizing enzymes. Synthetic inulin is a dietary component that completely evades glucide digestion. Supplementing a HF diet with inulin ameliorates hypertriglycemia and hepatic steatosis, but not hypercholesterolemia. This study aimed at distinguishing the effects of synthetic inulin and 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin), which inhibit cholesterol biosynthesis. Methods We examined effects of co-treatment with synthetic inulin (5%) and fluvastatin (0, 4, and 8 mg/kg, per os) on body weight, epidydimal white adipose tissue weight, serum and hepatic lipid profiles, and hepatic cytochrome P450 (CYP) mRNA and protein profiles in rats fed a standard diet or a HF diet for 3 weeks. Results Treatment with the synthetic inulin (5%) or fluvastatin at 4 mg/kg (lethal dose in rats fed the HF diet, 8 mg/kg) ameliorated the elevation in hepatic triacylglycerol and total cholesterol levels in rats fed the HF diet. Whereas co-treatment with the inulin (5%) and fluvastatin (4 mg/kg) had a tendency to more strongly suppress the elevation in serum levels of very low density lipoprotein triacylglycerol than either treatment alone, no additive or synergistic effect was found in decrease in hepatic lipid levels. Hepatic levels of CYP1A1/2 and CYP2E1 mRNA and protein and methoxyresorufin O-demethylase and ethoxyresorufin O-deethylase activities were reduced in rats fed the HF diet. The synthetic inulin alleviated the reduction in hepatic levels of CYP1A1/2 and CYP2E1 mRNA and protein more strongly than fluvastatin, and no synergistic effects were observed on co-treatment. Furthermore, hepatic levels of aryl hydrocarbon receptor mRNA were decreased in rats fed the HF diet and recovered to near normal values with the intake of dietary inulin, which correlated

5-lipoxygenase activation is involved in the mechanisms of chronic hepatic injury in a rat model of chronic aluminum overload exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mai, Shaoshan

We previously confirmed that rats overloaded with aluminum exhibited hepatic function damage and increased susceptibility to hepatic inflammation. However, the mechanism of liver toxicity by chronic aluminum overload is poorly understood. In this study, we investigated changes in the 5-lipoxygenase (5-LO) signaling pathway and its effect on liver injury in aluminum-overloaded rats. A rat hepatic injury model of chronic aluminum injury was established via the intragastric administration of aluminum gluconate (Al{sup 3+} 200 mg/kg per day, 5 days a week for 20 weeks). The 5-LO inhibitor, caffeic acid (10 and 30 mg/kg), was intragastrically administered 1 h after aluminum administration.more » Hematoxylin and eosin staining was used to visualize pathological changes in rat liver tissue. A series of biochemical indicators were measured with biochemistry assay or ELISAs. Immunochemistry and RT-PCR methods were used to detect 5-LO protein and mRNA expression in the liver, respectively. Caffeic acid administration protected livers against histopathological injury, decreased plasma ALT, AST, and ALP levels, decreased TNF-α, IL-6, IL-1β and LTs levels, increased the reactive oxygen species content, and down-regulated the mRNA and protein expressions of 5-LO in aluminum overloaded rats. Our results indicate that 5-lipoxygenase activation is mechanistically involved in chronic hepatic injury in a rat model of chronic aluminum overload exposure and that the 5-LO signaling pathway, which associated with inflammation and oxidative stress, is a potential therapeutic target for chronic non-infection liver diseases. - Highlights: • 5-LO signaling contributes to mechanisms of hepatotoxicity of aluminum overload. • Oxidative and inflammatory reaction involve in chonic aluminum hepatotoxicity. • 5-LO inhibitor has a protective effect on aluminum-overload liver injury. • 5-LO signaling is a potential therapeutic target for non-infection liver diseases.« less

Protective effects of a natural herbal compound quercetin against snake venom-induced hepatic and renal toxicities in rats.

PubMed

Al-Asmari, Abdulrahman K; Khan, Haseeb A; Manthiri, Rajamohamed A; Al-Khlaiwi, Ahmad A; Al-Asmari, Bayan A; Ibrahim, Khalid E

2018-05-08

Echis pyramidum is a highly poisonous viper snake. Previous studies have shown acute phase hepatic and renal toxicities of Echis pyramidum venom (EPV) in rats. This study reports the protective effects of a natural herbal compound quercetin (QRC) on EPV-induced hepatic and renal toxicities in rats. A singly injection of EPV (4.76 mg/kg) caused significant increase in serum biomarkers of liver and kidney function. Pre-treatment of QRC (10 mg/kg) significantly reduced the toxic effects of EPV on functional impairment in liver and kidneys of rats. Administration of QRC also reversed EPV-induced increase in lipid peroxidation and decrease in total thiols. The histopathology of liver showed fat accumulation, focal degeneration and cytoplasmic vacuolation of hepatocytes in EPV treated rats. EPV also caused renal tubular dilation and focal atrophy of glomerular tufts in rat kidneys. Administration of QRC prevented EPV-induced structural tissue damage in liver and kidneys of rats. In conclusion, QRC significantly inhibited the acute phase toxic effects of EPV on liver and kidneys of rats by preventing the oxidative stress in these organs. QRC is also known for its anti-inflammatory, anti-edema, anti-hemorrhagic and PLA2-inhibitory properties and therefore may be regarded as a multi-action antidote against snake venom toxicity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of model traumatic injury on hepatic drug metabolism in the rat. IV. Glucuronidation.

PubMed

Griffeth, L K; Rosen, G M; Rauckman, E J

1985-01-01

A previously validated small mammal trauma model, hind-limb ischemia secondary to infrarenal aortic ligation in the rat, was utilized to investigate the effects of traumatic injury on hepatic glucuronidation activity. As was previously observed with hepatic oxidative drug metabolism, model trauma resulted in a significant decrease in the in vivo glucuronidation of chloramphenicol, with a 23% drop in clearance of this drug. The effect on in vivo pharmacokinetics appeared to result from a complex interaction between trauma's differential influences on conjugating enzyme(s), deconjugating enzyme(s), and hepatic UDP-glucuronic acid levels, as well as the relative physiological importance of these variables. Hepatic UDP-glucuronyltransferase activities towards both p-nitrophenol and chloramphenicol were elevated (44-54%) after model injury when measured in native hepatic microsomes. However, microsomes which had been "activated" by treatment with Triton X-100 showed no significant difference between control and traumatized animals. Serum beta-glucuronidase activities were elevated by 58%, while hepatic beta-glucuronidase rose by about 16%. Nevertheless, in vivo deconjugation showed no significant change. Model trauma also resulted in a 46% decrease in hepatic UDP-glucuronic acid content. Thus, the observed post-traumatic depression of in vivo chloramphenicol glucuronidation could be due either to a diminished availability of a necessary cofactor (UDP-glucuronic acid) or to an alteration in enzyme kinetics or function in vivo.

Fractal and Fourier analysis of the hepatic sinusoidal network in normal and cirrhotic rat liver

PubMed Central

Gaudio, Eugenio; Chaberek, Slawomir; Montella, Andrea; Pannarale, Luigi; Morini, Sergio; Novelli, Gilnardo; Borghese, Federica; Conte, Davide; Ostrowski, Kazimierz

2005-01-01

The organization of the hepatic microvascular network has been widely studied in recent years, especially with regard to cirrhosis. This research has enabled us to recognize the distinctive vascular patterns in the cirrhotic liver, compared with the normal liver, which may explain the cause of liver dysfunction and failure. The aim of this study was to compare normal and cirrhotic rat livers by means of a quantitative mathematical approach based on fractal and Fourier analyses performed on photomicrographs and therefore on discriminant analysis. Vascular corrosion casts of livers belonging to the following three experimental groups were studied by scanning electron microscopy: normal rats, CCl4-induced cirrhotic rats and cirrhotic rats after ligation of the bile duct. Photomicrographs were taken at a standard magnification; these images were used for the mathematical analysis. Our experimental design found that use of these different analyses reaches an efficiency of over 94%. Our analyses demonstrated a higher complexity of the normal hepatic sinusoidal network in comparison with the cirrhotic network. In particular, the morphological changes were more marked in the animals with bile duct-ligation cirrhosis compared with animals with CCl4-induced cirrhosis. The present findings based on fractal and Fourier analysis could increase our understanding of the pathophysiological alterations of the liver, and may have a diagnostic value in future clinical research. PMID:16050897

Hepatic Stellate Cells Inhibit T Cells through Active TGF-β1 from a Cell Surface-Bound Latent TGF-β1/GARP Complex.

PubMed

Li, Yan; Kim, Byung-Gyu; Qian, Shiguang; Letterio, John J; Fung, John J; Lu, Lina; Lin, Feng

2015-09-15

Hepatic stellate cells (HSCs) inhibit T cells, a process that could help the liver to maintain its immunoprivileged status. HSCs secrete latent TGF-β1, but the detailed mechanisms by which latent TGF-β1 is activated and whether it plays any role in HSC-mediated T cell suppression remain unclear. Glycoprotein A repetitions predominant (GARP) is a surface marker of activated regulatory T cells. GARP binds latent TGF-β1 for its activation, which is critical for regulatory T cells to suppress effector T cells; however, it is still unclear whether GARP is present on HSCs and whether it has any impact on HSC function. In this study, we found that TGF-β1(+/-) HSCs, which produce reduced levels of TGF-β1, showed decreased potency in inhibiting T cells. We also found that pharmaceutical or genetic inhibition of the TGF-β1 signaling pathway reduced the T cell-inhibiting activity of HSCs. Additionally, using isolated primary HSCs, we demonstrated that GARP was constitutively expressed on HSCs. Blocking GARP function or knocking down GARP expression significantly impaired the potency of HSCs to suppress the proliferation of and IFN-γ production from activated T cells, suggesting that GARP is important for HSCs to inhibit T cells. These results demonstrate the unexpected presence of GARP on HSCs and its significance in regard to the ability of HSCs to activate latent TGF-β1 and thereby inhibit T cells. Our study reveals a new mechanism for HSC-mediated immune regulation and potentially for other conditions, such as liver fibrosis, that involve HSC-secreted TGF-β1. Copyright © 2015 by The American Association of Immunologists, Inc.

Age-Related Pseudocapillarization of the Liver Sinusoidal Endothelium Impairs the Hepatic Clearance of Acetaminophen in Rats

PubMed Central

Huizer-Pajkos, Aniko; Cogger, Victoria C.; McLachlan, Andrew J.; Le Couteur, David G.; Jones, Brett; de Cabo, Rafael; Hilmer, Sarah N.

2011-01-01

We investigated the effect of age-related pseudocapillarization of the liver sinusoidal endothelium on the hepatic disposition of acetaminophen. The multiple indicator dilution technique assessed the hepatic disposition of tracer 14C-acetaminophen and reference markers in isolated perfused livers of young (n = 11) and old (n = 12) rats. Electron microscopy confirmed defenestration of the sinusoidal endothelium in old rats compared with young rats. Acetaminophen recovery following a single pass through the liver was significantly increased in old rats (0.64 ± 0.04, old; 0.59 ± 0.05, young; p < .05). In old age, there was significant reduction of the intercompartmental rate constant k1 (0.34 ± 0.10s-1, old; 0.61 ± 0.38s-1, young; p < .05) and the permeability-surface area product for the transfer of acetaminophen across the sinusoidal endothelium (0.034 ± 0.006 mL/s/g, old; 0.048 ± 0.014 mL/s/g, young; p < .005). There was no difference in k3, the measure of sequestration of acetaminophen that reflects enzyme activity. Age-related pseudocapillarization of the liver sinusoid resulted in increased acetaminophen recovery and decreased transfer of acetaminophen into the liver. PMID:21300741

Vitamin A-coupled liposome system targeting free cholesterol accumulation in hepatic stellate cells offers a beneficial therapeutic strategy for liver fibrosis.

PubMed

Furuhashi, Hirotaka; Tomita, Kengo; Teratani, Toshiaki; Shimizu, Motonori; Nishikawa, Makoto; Higashiyama, Masaaki; Takajo, Takeshi; Shirakabe, Kazuhiko; Maruta, Koji; Okada, Yoshikiyo; Kurihara, Chie; Watanabe, Chikako; Komoto, Shunsuke; Aosasa, Suefumi; Nagao, Shigeaki; Yamamoto, Junji; Miura, Soichiro; Hokari, Ryota

2018-04-01

Liver fibrosis is a life-threatening disorder for which no approved therapy is available. Recently, we reported that mouse hepatic stellate cell (HSC) activation increased free cholesterol (FC) accumulation, partly by enhancing signaling through sterol regulatory element-binding protein 2 (SREBP2) and microRNA-33a (miR-33a), which resulted in HSC sensitization to transforming growth factor-β (TGFβ)-induced activation in a "vicious cycle" of liver fibrosis. Human HSCs were isolated from surgical liver specimens from control patients and patients with liver fibrosis. C57BL/6 mice were treated with carbon tetrachloride for 4 weeks and concurrently given SREBP2-siRNA- or anti-miR-33a-bearing vitamin A-coupled liposomes. In human activated HSCs obtained from patients with liver fibrosis, FC accumulation was enhanced independently of serum cholesterol levels through increased signaling by both SREBP2 and miR-33a. This increased FC accumulation enhanced Toll-like receptor 4 (TLR4) protein levels and lowered the TGFβ-pseudoreceptor Bambi (bone morphogenetic protein and activin membrane-bound inhibitor) mRNA levels in HSCs. Notably, in a mouse liver fibrosis model, reduction of FC accumulation, specifically in activated HSCs by suppression of SREBP2 or miR-33a expression using SREBP2-siRNA- or anti-miR-33a-bearing vitamin A-coupled liposomes, downregulated TLR4 signaling, increased Bambi expression, and consequently ameliorated liver fibrosis. Our results suggest that FC accumulation in HSCs, as an intracellular mediator promoting HSC activation, contributes to a vicious cycle of HSC activation in human and mouse liver fibrosis independent of serum cholesterol levels. Targeting FC accumulation-related molecules in HSCs through a vitamin A-coupled liposomal system represents a favorable therapeutic strategy for liver fibrosis. © 2017 The Japan Society of Hepatology.

Standardized Salvia miltiorrhiza extract suppresses hepatic stellate cell activation and attenuates steatohepatitis induced by a methionine-choline deficient diet in mice.

PubMed

Lee, Hak Sung; Son, Woo-Chan; Ryu, Jae-Eun; Koo, Bon Am; Kim, Yeong Shik

2014-06-17

The aim of this study was to examine the effect of standardized extract of Salvia miltiorrhiza (SME) on gene and protein expression of non-alcoholic steatohepatitis (NASH)-related factors in activated human hepatic stellate cells (HSC), and in mice with steatohepatitis induced by a methionine-choline deficient (MCD) diet. Male C57BL/6J mice were placed on an MCD or control diet for 8 weeks and SME (0, 0.1, 0.5 and 1 mg/kg body weight) was administered orally every other day for 4 or 6 weeks. HSCs from the LX-2 cell line were treated with transforming growth factor β-1 (TGF-β1) or TGF-β1 plus SME (0.1-10 μg/mL). To investigate the effect of SME on reactive oxygen species (ROS)-induced condition, LX-2 cells were treated with hydrogen peroxide (H2O2) or H2O2 plus SME (0.1-100 μg/mL). MCD administration for 12 weeks increased mRNA expression of tumor necrosis factor (TNF-α), TGF-β1, interleukin-1β (IL-1β), C-reactive protein (CRP), α-smooth muscle actin (α-SMA), type I collagen, matrix metalloproteinase-2 (MMP-2) and MMP-9. TGF-β1-induced LX-2 cells exhibited similar gene expression patterns. SME treatment significantly reduced the mRNA and protein expression of NASH-related factors in the mouse model and HSCs. Histopathological liver analysis showed improved non-alcoholic fatty liver disease (NAFLD) activity and fibrosis score in SME-treated mice. The in vivo studies showed that SME had a significant effect at low doses. These results suggest that SME might be a potential therapeutic candidate for NAFLD treatment.

Naringin in Ganshuang Granule suppresses activation of hepatic stellate cells for anti-fibrosis effect by inhibition of mammalian target of rapamycin.

PubMed

Shi, Hongbo; Shi, Honglin; Ren, Feng; Chen, Dexi; Chen, Yu; Duan, Zhongping

2017-03-01

A previous study has demonstrated that Ganshuang granule (GSG) plays an anti-fibrotic role partially by deactivation of hepatic stellate cells (HSCs). In HSCs activation, mammalian target of rapamycin (mTOR)-autophagy plays an important role. We attempted to investigate the role of mTOR-autophagy in anti-fibrotic effect of GSG. The cirrhotic mouse model was prepared to demonstrate the anti-fibrosis effect of GSG. High performance liquid chromatography (HPLC) analyses were used to identify the active component of GSG. The primary mouse HSCs were isolated and naringin was added into activated HSCs to observe its anti-fibrotic effect. 3-methyladenine (3-MA) and Insulin-like growth factor-1 (IGF-1) was added, respectively, into fully activated HSCs to explore the role of autophagy and mTOR. GSG played an anti-fibrotic role through deactivation of HSCs in cirrhotic mouse model. The concentration of naringin was highest in GSG by HPLC analyses and naringin markedly suppressed HSCs activation in vitro, which suggested that naringin was the main active component of GSG. The deactivation of HSCs caused by naringin was not because of the autophagic activation but mTOR inhibition, which was supported by the following evidence: first, naringin induced autophagic activation, but when autophagy was blocked by 3-MA, deactivation of HSCs was not attenuated or reversed. Second, naringin inhibited mTOR pathway, meanwhile when mTOR was activated by IGF-1, deactivation of HSCs was reversed. In conclusion, we have demonstrated naringin in GSG suppressed activation of HSCs for anti-fibrosis effect by inhibition of mTOR, indicating a potential therapeutic application for liver cirrhosis. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Expression of CD163 in the liver of patients with viral hepatitis.

PubMed

Hiraoka, Atsushi; Horiike, Norio; Akbar, Sk Md Fazle; Michitaka, Kojiro; Matsuyama, Takami; Onji, Morikazu

2005-01-01

CD163 is a marker of activated macrophages, and increased levels of soluble CD163 have been detected in sera obtained from patients with hepatitis. The aim of this study was to detect the expression of CD163 in the liver from patients with viral hepatitis. Frozen sections of liver specimens were obtained from 5 patients with acute viral hepatitis (AH) and from 23 patients with chronic viral hepatitis (CH). The expression of CD163 in the liver was determined immunohistochemically using monoclonal antibody to human CD163. Double immunostaining was done to assess those cell types that express CD163 in the liver. The frequencies of CD163-positive cells were significantly higher both in the portal areas and in the hepatic lobules in the liver of patients with AH compared to those with CH (p < 0.05). Double immunostaining revealed that most of the CD163-positive cells were macrophages and Kupffer cells, because they expressed CD68. The expression of CD163 was very low in endothelial cells and liver stellate cells. This study shows that macrophages are activated in hepatitis liver.

Dietary phytic acid prevents fatty liver by reducing expression of hepatic lipogenic enzymes and modulates gut microflora in rats fed a high-sucrose diet.

PubMed

Sekita, Ayaka; Okazaki, Yukako; Katayama, Tetsuyuki

2016-06-01

The aim of this study was to investigate the effect of phytic acid (PA) on fatty liver and gut microflora in rats fed a high-sucrose (HSC) diet. Three groups of rats were fed a high-starch (HSR) diet or an HSC diet with or without 1.02% sodium PA for 12 d. We evaluated hepatic weight, total lipids, and triacylglycerol (TG) levels, the activities and expression of hepatic lipogenic enzymes (glucose-6-phosphate dehydrogenase, malic enzyme 1, and fatty acid synthetase), and fecal microflora. The HSC diet significantly increased hepatic total lipids and TG levels, and the activities and expression of the hepatic lipogenic enzymes compared with the HSR diet. These upregulations were clearly suppressed by dietary PA. Consumption of PA elevated the fecal ratio of Lactobacillus spp. and depressed the ratio of Clostridium cocoides, and suppressed the elevation in the ratio of C. leptum induced by the HSC diet. This work showed that dietary PA ameliorates sucrose-induced fatty liver through reducing the expression of hepatic lipogenesis genes and modulates gut microflora in rats. Copyright © 2016 Elsevier Inc. All rights reserved.

Silymarin-loaded Eudragit(®) RS100 nanoparticles improved the ability of silymarin to resolve hepatic fibrosis in bile duct ligated rats.

PubMed

Younis, N; Shaheen, Mohamed A; Abdallah, Marwa H

2016-07-01

Some nano-formulations of silymarin (SM), a drug commonly used for liver diseases, were developed to overcome its poor solubility and poor bioavailability; antifibrotic effect of these formulations has not been tested yet. In this study we aimed to formulate and evaluate silymarin-loaded Eudragit(®) RS100 nanoparticles (SMnps) and to test the capability of SMnps to reverse an established fibrosis model. SMnps were prepared by solvent evaporation and nano-precipitation techniques. The influence of drug:polymer ratio, concentration of surfactant in the aqueous phase on particle size, drug entrapment efficiency (EE) % and in vitro drug releases were investigated. For in vivo evaluation, bile duct ligated (BDL)-rats were treated with either SM or SMnps every other day (125mg/kg) orally for 3 weeks started 3 weeks after BDL. Liver function tests, oxidative stress and fibrosis/fibrogenesis process were evaluated using biochemical and histopathological techniques. The formulation No (F4) of SMnps showed an average particle size of 632.28±12.15nm, a drug EE% of 89.47±1.65% and released the drug in a prolonged manner over 24h. The prepared SMnps were nearly spherical with smooth surfaces. In BDL-rats, treatments with either SM or SMnps corrected liver function and oxidative stress. Only SMnps was able to reverse the induced fibrosis; SMnps significantly decreased serum tumor necrosis factor- α (TNF-α), serum transforming growth factor- β1 (TGF-β1), hepatic hydroxyproline and downregulated the hepatic expression of tissue inhibitor metalloproteinase-1 (TIMP-1) and cytokeratin-19 (CK-19), whilst increased hepatic hepatocytes growth factor (HGF) and upregulated the hepatic expression of matrix metalloproteinase-2 (MMP-2) and increased MMP-2/TIMP-1 ratio at mRNA level. Livers of rats treated with SMnps showed very little collagen in ECM and restored hepatic architecture as compared to either BDL rats or rats treated with SM. Formulation of silymarin as nanoparticles

Organic Anion-Transporting Polypeptide and Efflux Transporter-Mediated Hepatic Uptake and Biliary Excretion of Cilostazol and Its Metabolites in Rats and Humans.

PubMed

Wang, Chong; Huo, Xiaokui; Wang, Changyuan; Meng, Qiang; Liu, Zhihao; Sun, Pengyuan; Cang, Jian; Sun, Huijun; Liu, Kexin

2017-09-01

Cilostazol undergoes extensive liver metabolism. However, the transporter-mediated hepatic disposition of cilostazol remains unknown. The present study was performed to investigate the hepatic uptake and biliary excretion of cilostazol and its metabolites (OPC-13015 and OPC-13213) using rat liver and human transporter-transfected cells in vitro. Cilostazol uptake by rat liver slices and isolated rat hepatocytes exhibited time-, concentration-, and temperature dependency and was decreased by Oatp inhibitors, which suggested that Oatp was involved in the hepatic uptake of cilostazol. Cilostazol uptake in rat hepatocytes, OATP1B1-, and OATP1B3-HEK293 cells indicated a saturable process with K m values of 2.7 μM, 17.7 μM, and 2.7 μM, respectively. Epigallocatechin gallate, cyclosporin A, rifampicin, and telmisartan inhibited cilostazol uptake in OATP1B1/1B3-HEK293 cells with K i values close to their clinical plasma concentration, which suggested possible drug-drug interactions in humans via OATP1B1/1B3. Moreover, the cumulative biliary excretion of cilostazol and OPC-13015 was significantly decreased by quinidine, bilirubin, and novobiocin in perfused rat liver, but OPC-13213 biliary excretion was only inhibited by novobiocin, which suggested that the efflux transporters Mrp2, Bcrp, and P-gp were involved in the biliary excretion of cilostazol and its metabolites. Our findings indicated that multiple transporters were involved in the hepatic disposition of cilostazol and its metabolites. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Sugary Kefir Strain Lactobacillus mali APS1 Ameliorated Hepatic Steatosis by Regulation of SIRT-1/Nrf-2 and Gut Microbiota in Rats.

PubMed

Chen, Yung-Tsung; Lin, Yu-Chun; Lin, Jin-Seng; Yang, Ning-Sun; Chen, Ming-Ju

2018-04-01

Non-alcoholic fatty liver disease (NAFLD) is a common disease that is concomitant with obesity, resulting in increased mortality. To date, the efficiency of NAFLD treatment still needs to be improved. Therefore, we aimed to evaluate the effect of Lactobacillus mali APS1, which was isolated from sugary kefir, on hepatic steatosis in rats fed a high-fat diet (HFD). Sprague Dawley rats were fed a control diet, a HFD with saline, and a HFD with APS1 intervention by gavage daily for 12 weeks. The results showed that APS1 significantly reduced body weight and body weight gain in HFD-fed rats. APS1 reduced hepatic lipid accumulation by regulating SIRT-1/PGC-1α/SREBP-1 expression. Moreover, APS1 increased hepatic antioxidant activity by modulating Nrf-2/HO-1 expression. Notably, APS1 manipulated the gut microbiota, resulting in increasing proportions of the phylum Bacteroidetes/Firmicutes and reducing the abundance of specific NAFLD-associated bacteria. These results suggested that APS1 ameliorated hepatic steatosis by modulating lipid metabolism and antioxidant activity via manipulating specific NAFLD-associated gut microbiota in vivo. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

188Re-SSS lipiodol: radiolabelling and biodistribution following injection into the hepatic artery of rats bearing hepatoma.

PubMed

Garin, Etienne; Denizot, Benoit; Noiret, Nicolas; Lepareur, Nicolas; Roux, Jerome; Moreau, Myriam; Herry, Jean-Yves; Bourguet, Patrick; Benoit, Jean-Pierre; Lejeune, Jean-Jacques

2004-10-01

Although intra-arterial radiation therapy with 131I-lipiodol is a useful therapeutic approach to the treatment of hepatocellular carcinoma, various disadvantages limit its use. To describe the development of a method for the labelling of lipiodol with 188Re-SSS (188Re (S2CPh)(S3CPh)2 complex) and to investigate its biodistribution after injection into the hepatic artery of rats with hepatoma. 188Re-SSS lipiodol was obtained after dissolving a chelating agent, previously labelled with 188Re, in cold lipiodol. The radiochemical purity (RCP) of labelling was checked immediately. The 188Re-SSS lipiodol was injected into the hepatic artery of nine rats with a Novikoff hepatoma. They were sacrificed 1, 24 and 48 h after injection, and used for ex vivo counting. Labelling of 188Re-SSS lipiodol was achieved with a yield of 97.3+/-2.1%. The immediate RCP was 94.1+/-1.7%. Ex vivo counting confirmed a predominantly hepatic uptake, with a good tumoral retention of 188Re-SSS lipiodol, a weak pulmonary uptake and a very faint digestive uptake. The 'tumour/non-tumoral liver' ratio was high at 1, 24 and 48 h after injection (2.9+/-1.5, 4.1+/-/4.1 and 4.1+/-0.7, respectively). Using the method described here, 188Re-SSS lipiodol can be obtained with a very high yield and a satisfactory RCP. The biodistribution in rats with hepatoma indicates a good tumoral retention of 188Re-SSS lipiodol associated with a predominant hepatic uptake, a weak pulmonary uptake and a very faint digestive uptake. This product should be considered for intra-arterial radiation therapy in human hepatoma.

Subacute effects of hexabromocyclododecane (HBCD) on hepatic gene expression profiles in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Canton, Rocio F.; Peijnenburg, Ad A.C.M.; Hoogenboom, Ron L.A.P.

2008-09-01

Hexabromoyclododecane (HBCD), used as flame retardant (FR) mainly in textile industry and in polystyrene foam manufacture, has been identified as a contaminant at levels comparable to other brominated FRs (BFRs). HBCD levels in biota are increasing slowly and seem to reflect the local market demand. The toxicological database of HBCD is too limited to perform at present a solid risk assessment, combining data from exposure and effect studies. In order to fill in some gaps, a 28-day HBCD repeated dose study (OECD407) was done in Wistar rats. In the present work liver tissues from these animals were used for genemore » expression profile analysis. Results show clear gender specificity with females having a higher number of regulated genes and therefore being more sensitive to HBCD than males. Several specific pathways were found to be affected by HBCD exposure, like PPAR-mediated regulation of lipid metabolism, triacylglycerol metabolism, cholesterol biosynthesis, and phase I and II pathways. These results were corroborated with quantitative RT-PCR analysis. Cholesterol biosynthesis and lipid metabolism were especially down-regulated in females. Genes involved in phase I and II metabolism were up-regulated predominantly in males, which could explain the observed lower HBCD hepatic disposition in male rats in this 28-day study. These sex-specific differences in gene expression profiles could also underlie sex-specific differences in toxicity (e.g. decreased thyroid hormone or increased serum cholesterol levels). To our knowledge, this is the fist study that describes the changes in rat hepatic gene profiles caused by this commonly used flame retardant.« less

Dioscin alleviates BDL- and DMN-induced hepatic fibrosis via Sirt1/Nrf2-mediated inhibition of p38 MAPK pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, Lina; Tao, Xufeng; Xu, Youwei

Oxidative stress is involved in hepatic stellate cells (HSCs) activation and extracellular matrix overproduction. We previously reported the promising effects of dioscin against CCl{sub 4}-induced liver fibrosis, but its effects and mechanisms on BDL- and DMN-induced liver fibrosis remain unknown. The results in the present study indicated that dioscin significantly inhibited HSCs activation and attenuated hepatic fibrosis in rats. Furthermore, dioscin markedly up-regulated the levels of sirtuin 1 (Sirt1), HO-1, GST, GCLC and GCLM via increasing the nuclear translocation of nuclear erythroid factor 2-related factor 2 (Nrf2), which in turn inhibited mitogen-activated protein kinase 14 (p38 MAPK) phosphorylation and reducedmore » the levels of COL1A1, COL3A1, α-SMA and fibronectin. These results were further validated by knockdown of Sirt1 and Nrf2 using siRNAs silencing, and abrogation of p38 MAPK using SB-203580 (a p38 MAPK inhibitor) in HSC-T6 and LX-2 cells. Collectively, our findings confirmed the potent effects of dioscin against liver fibrosis and also provided novel insights into the mechanisms of this compound as a candidate for the prevention of liver fibrosis in the future. - Highlights: • Dioscin showed potent effects against BDL- and DMN-induced liver fibrosis in rats. • Dioscin significantly suppressed oxidative stress. • Dioscin triggered Sirt1/Nrf2-mediated inhibition of p38 MAPK pathway. • Dioscin should be developed as a novel candidate to treat liver fibrosis.« less

Thalamic pain alleviated by stellate ganglion block: A case report.

PubMed

Liao, Chenlong; Yang, Min; Liu, Pengfei; Zhong, Wenxiang; Zhang, Wenchuan

2017-02-01

Thalamic pain is a distressing and treatment-resistant type of central post-stroke pain. Although stellate ganglion block is an established intervention used in pain management, its use in the treatment of thalamic pain has never been reported. A 66-year-old woman presented with a 3-year history of severe intermittent lancinating pain on the right side of the face and the right hand. The pain started from the ulnar side of the right forearm after a mild ischemic stroke in bilateral basal ganglia and left thalamus. Weeks later, the pain extended to the dorsum of the finger tips and the whole palmar surface, becoming more severe. Meanwhile, there was also pain with similar characteristics emerging on her right face, resembling atypical trigeminal neuralgia. Thalamic pain was diagnosed. After refusing the further invasive treatment, she was suggested to try stellate ganglion block. After a 3-day period of pain free (numerical rating scale: 0) postoperatively, she reported moderate to good pain relief with a numerical rating scale of about 3 to 4 lasting 1 month after the first injection. Pain as well as the quality of life was markedly improved with less dose of analgesic agents. Stellate ganglion block may be an optional treatment for thalamic pain.

FLUCONAZOLE-INDUCED HEPATIC CYTOCHROME P450 GENE EXPRESSION AND ENZYMATIC ACTIVITIES IN RATS AND MICE

EPA Science Inventory

This study was undertaken to examine the effects of the triazole antifungal agent fluconazole on the expression of hepatic cytochrome P450 (Cyp) genes and the activities of Cyp enzymes in male Sprague-Dawley rats and male CD-1 mice. Alkoxyresorufin O-dealkylation (AROD) methods w...

Stellate and pyramidal neurons in goldfish telencephalon respond differently to anoxia and GABA receptor inhibition.

PubMed

Hossein-Javaheri, Nariman; Wilkie, Michael P; Lado, Wudu E; Buck, Leslie T

2017-02-15

With oxygen deprivation, the mammalian brain undergoes hyper-activity and neuronal death while this does not occur in the anoxia-tolerant goldfish ( Carassius auratus ). Anoxic survival of the goldfish may rely on neuromodulatory mechanisms to suppress neuronal hyper-excitability. As γ-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the brain, we decided to investigate its potential role in suppressing the electrical activity of goldfish telencephalic neurons. Utilizing whole-cell patch-clamp recording, we recorded the electrical activities of both excitatory (pyramidal) and inhibitory (stellate) neurons. With anoxia, membrane potential ( V m ) depolarized in both cell types from -72.2 mV to -57.7 mV and from -64.5 mV to -46.8 mV in pyramidal and stellate neurons, respectively. While pyramidal cells remained mostly quiescent, action potential frequency (AP f ) of the stellate neurons increased 68-fold. Furthermore, the GABA A receptor reversal potential ( E - GABA ) was determined using the gramicidin perforated-patch-clamp method and found to be depolarizing in pyramidal (-53.8 mV) and stellate neurons (-42.1 mV). Although GABA was depolarizing, pyramidal neurons remained quiescent as E GABA was below the action potential threshold (-36 mV pyramidal and -38 mV stellate neurons). Inhibition of GABA A receptors with gabazine reversed the anoxia-mediated response. While GABA B receptor inhibition alone did not affect the anoxic response, co-antagonism of GABA A and GABA B receptors (gabazine and CGP-55848) led to the generation of seizure-like activities in both neuron types. We conclude that with anoxia, V m depolarizes towards E GABA which increases AP f in stellate neurons and decreases AP f in pyramidal neurons, and that GABA plays an important role in the anoxia tolerance of goldfish brain. © 2017. Published by The Company of Biologists Ltd.

Restorative effects of hydroxysafflor yellow A on hepatic function in an experimental regression model of hepatic fibrosis induced by carbon tetrachloride

PubMed Central

Li, Yanuo; Shi, Yan; Sun, Yan; Liu, Luying; Bai, Xianyong; Wang, Dong; Li, Hongxing

2017-01-01

Hepatic fibrosis is a reversible pathological process, in which fibrotic tissue is excessively deposited in the liver during the repair process that follows hepatic injury. Early prevention or treatment of hepatic fibrosis has great significance on the treatment of chronic hepatic diseases. Hydroxysafflor yellow A (HSYA) is a water-soluble monomer extracted from safflower, which serves numerous pharmacological roles. However, it remains to be elucidated how HSYA regulates hepatic fibrogenesis. The aim of the present study was to reveal the possible mechanisms underlying the effects of HSYA on the prevention and treatment of hepatic fibrosis. A rat model of hepatic fibrosis was established in the present study, and the rats were administered various doses of HSYA. The effects of HSYA on pathological alterations of the liver tissue in rats with hepatic fibrosis were observed using hematoxylin-eosin staining and Masson staining. In order to explore the anti-hepatic fibrosis effects and underlying mechanisms of HSYA, serum levels, and hepatic function and hepatic fibrosis indices were evaluated. The results demonstrated that HSYA can improve the general condition of rats with hepatic fibrosis and relieve cellular swelling of the liver, fatty degeneration, necrosis, inflammatory cell infiltration and fibroplastic proliferation. Subsequent to administration of HSYA, globulin was increased during hepatic fibrosis caused by tetrachloromethane. However, total cholesterol, triglyceride, alanine aminotransferase, aspartate aminotransferase and levels of hyaluronic acid, laminin, procollagen III N-terminal peptide, collagen type IV and hydroxyproline were significantly reduced. The results additionally demonstrated that HSYA could enhance superoxide dismutase activity and reduce malondialdehyde levels, inhibiting lipid peroxidation caused by free radicals. PMID:27909717

Lead nitrate-induced development of hypercholesterolemia in rats: sterol-independent gene regulation of hepatic enzymes responsible for cholesterol homeostasis.

PubMed

Kojima, Misaki; Masui, Toshimitsu; Nemoto, Kiyomitsu; Degawa, Masakuni

2004-12-01

Changes in the gene expressions of hepatic enzymes responsible for cholesterol homeostasis were examined during the process of lead nitrate (LN)-induced development of hypercholesterolemia in male rats. Total cholesterol levels in the liver and serum were significantly increased at 3-72 h and 12-72 h, respectively, after LN-treatment (100 micromol/kg, i.v.). Despite the development of hypercholesterolemia, the genes for hepatic 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) and other enzymes (FPPS, farnesyl diphosphate synthase; SQS, squalene synthase; CYP51, lanosterol 14alpha-demethylase) responsible for cholesterol biosynthesis were activated at 3-24 h and 12-18 h, respectively. On the other hand, the gene expression of cholesterol 7alpha-hydroxylase (CYP7A1), a catabolic enzyme of cholesterol, was remarkably suppressed at 3-72 h. The gene expression levels of cytokines interleukin-1beta (IL-1beta) and TNF-alpha, which activate the HMGR gene and suppress the CYP7A1 gene, were significantly increased at 1-3 h and 3-24 h, respectively. Furthermore, gene activation of SREBP-2, a gene activator of several cholesterogenic enzymes, occurred before the gene activations of FPPS, SQS and CYP51. This is the first report demonstrating sterol-independent gene regulation of hepatic enzymes responsible for cholesterol homeostasis in LN-treated male rats. The mechanisms for the altered-gene expressions of hepatic enzymes in LN-treated rats are discussed.