Effects of lipopolysaccharides stimulated Kupffer cells on activation of rat hepatic stellate cells

Jaceosidin attenuates the progression of hepatic fibrosis by inhibiting the VGLL3/HMGB1/TLR4 signaling pathway

BACKGROUND

Jaceosidin (JA) is a natural flavone extracted from Artemisia that is used as a food and traditional medicinal herb. It has been reported to possess numerous biological activities. However, the regulatory mechanisms underlying amelioration of hepatic fibrosis remain unclear.

HYPOTHESIS/PURPOSE

We hypothesized that jaceosidin acid (JA) modulates hepatic fibrosis and inflammation.

METHODS

Thioacetamide (TAA) was used to establish an HF mouse model. In vitro, mouse primary hepatocytes and HSC-T6 cells were induced by TGF-β, whereas mouse peritoneal macrophages received a treatment lipopolysaccharide (LPS)/ATP.

RESULTS

JA decreased serum transaminase levels and improved hepatic histological pathology in TAA-treated mice stimulated by TAA. Moreover, the expression of pro-fibrogenic biomarkers associated with the activation of liver stellate cells was downregulated by JA. Likewise, JA down-regulated the expression of vestigial-like family member 3 (VGLL3), high mobility group protein B1 (HMGB1), toll-like receptors 4 (TLR4), and nucleotide-binding domain-(NOD-) like receptor protein 3 (NLRP3), thereby inhibiting the inflammatory response and inhibiting the release of mature-IL-1β in TAA-stimulated mice. Additionally, JA suppressed HMGB1 release and NLRP3/ASC inflammasome activation in LPS/ATP-stimulated murine peritoneal macrophages. JA decreases the expression of pro-fibrogenic biomarkers related to liver stellate cell activation and inhibits inflammasome activation in mouse primary hepatocytes. It also down-regulated α-SMA and VGLL3 expressions and also suppressed inflammasome activation in HSC-T6 cells. VGLL3 and α-SMA expression levels were decreased in TGF-β-stimulated HSC-T6 cells following Vgll3 knockdown. In addition, the expression levels of NLRP3 and cleaved-caspase-1 were decreased in Vgll3-silenced HSC-T6 cells. JA enhanced the inhibitory effects on Vgll3-silenced HSC-T6 cells. Finally, Vgll3 overexpression in HSC-T6 cells affected the expression levels of α-SMA, NLRP3, and cleaved-caspase-1.

CONCLUSION

JA effectively modulates hepatic fibrosis by suppressing fibrogenesis and inflammation via the VGLL3/HMGB1/TLR4 axis. Therefore, JA may be a candidate therapeutic agent for the management of hepatic fibrosis. Understanding the mechanism of action of JA is a novel approach to hepatic fibrosis therapy.

Antifibrotic effects of hypocalcemic vitamin D analogs in murine and human hepatic stellate cells and in the CCl4 mouse model

Liver cirrhosis is a life-threatening consequence of liver fibrosis. The aim of this study was to investigate the antifibrotic potential of clinically available vitamin D analogs compared to that of calcitriol in vitro and in vivo. Murine hepatic stellate cells, Kupffer cells, and human LX-2 cells were treated with vitamin D analogs, and the profibrotic behavior of these cells was studied. In vivo liver fibrosis was induced using CCl₄ until measurable fibrosis was established. Animals were then treated with calcitriol and paricalcitol. Vitamin D and its analogs showed antifibrotic effects in vitro. Treatment with active vitamin D (calcitriol, CAL) and its analogs reduced the protein expression of α-smooth muscle actin (α-SMA) in mHSC. In human LX-2 cells alfacalcidol reduced transforming growth factor-β (TGF-β) induced platelet-derived growth factor receptor-β protein expression and contractility while paricalcitol (PCT), in its equipotent dose to CAL, reduced TGF-β induced α-SMA protein expression, and ACTA2 and TGF-β mRNA expression. No effects of a treatment with vitamin D and its analogs were observed in Kupffer cells. In vivo, PCT-treated mice had significantly lower calcium levels than CAL-treated mice. CAL and PCT reduced the hepatic infiltration of CD11b-positive cells and alanine transaminase levels, while PCT but not CAL significantly inhibited fibrosis progression, with a favorable side effect profile in the CCl₄ model. We conclude that hypocalcemic vitamin D analogs should be considered in future studies investigating vitamin D for the treatment of liver fibrosis.

Use of Dual-Ligand Modification in Kupffer Cell-Targeted Liposomes To Examine the Contribution of Kupffer Cells to Accelerated Blood Clearance Phenomenon

The "accelerated blood clearance (ABC) phenomenon" is known to be involved in the adaptive immune system. Regretfully, the relationship between the ABC phenomenon and innate immune system, especially with respect to Kupffer cells (KCs) has been largely unexplored. In this study, the contribution of KCs to ABC was examined using the 4-aminophenyl-α-d-mannopyranoside (APM) lipid derivative DSPE-PEG₂₀₀₀-APM (DPM) and the 4-aminophenyl-β-l-fucopyranoside (APF) lipid derivative DSPE-PEG₂₀₀₀-APF (DPF) as ligands for mannose/fucose receptors on KCs, which were synthesized and modified on the surface of liposomes. The results of cellular liposome uptake in vitro and biodistribution in vivo indicated that DPM and DPF comodified liposomes (MFPL5-5) present the strongest capability of KC-targeting among all preparations tested. In rats pretreated with MFPL5-5 instead of PEGylated liposomes (PL), the ABC phenomenon was significantly enhanced and the distribution of liposomes in the liver was increased. Cellular uptake of the second injection of PL in vivo demonstrated that KCs was responsible for the uptake. Furthermore, compared to pretreatment with PL, the uptake of second injection of PL was more enhanced when pretreated with MFPL5-5. These findings suggest that KCs, which are considered traditional members of the innate immune system, play a crucial role in the ABC phenomenon and act as a supplement to the phenomenon.

Molecular hydrogen upregulates heat shock response and collagen biosynthesis, and downregulates cell cycles: meta-analyses of gene expression profiles

Molecular hydrogen exerts its effect on multiple pathologies, including oxidative stress, inflammation, and apoptosis. However, its molecular mechanisms have not been fully elucidated. In order to explore the effects of molecular hydrogen, we meta-analysed gene expression profiles modulated by molecular hydrogen. We performed microarray analysis of the mouse liver with or without drinking hydrogen water. We also integrated two previously reported microarray datasets of the rat liver into meta-analyses. We used two categories of meta-analysis methods: the cross-platform method and the conventional meta-analysis method (Fisher's method). For each method, hydrogen-modulated pathways were analysed by (i) the hypergeometric test (HGT) in the class of over-representation analysis (ORA), (ii) the gene set enrichment analysis (GSEA) in the class of functional class scoring (FCS), and (iii) the signalling pathway impact analysis (SPIA), pathway regulation score (PRS), and others in the class of pathway topology-based approach (PTA). Pathways in the collagen biosynthesis and the heat-shock response were up-regulated according to (a) HGT with the cross-platform method, (b) GSEA with the cross-platform method, and (c) PRS with the cross-platform method. Pathways in cell cycles were down-regulated according to (a) HGT with the cross-platform method, (b) GSEA with the cross-platform method, and (d) GSEA with the conventional meta-analysis method. Because the heat-shock response leads to up-regulation of collagen biosynthesis and a transient arrest of cell cycles, induction of the heat-shock response is likely to be a primary event induced by molecular hydrogen in the liver of wild-type rodents.

Extracts of Salvia-Nelumbinis Naturalis Ameliorate Nonalcoholic Steatohepatitis via Inhibiting Gut-Derived Endotoxin Mediated TLR4/NF-κB Activation

Nonalcoholic steatohepatitis (NASH) is featured by the presence of hepatic steatosis combined with inflammation and hepatocellular injury. Gut-derived endotoxin plays a crucial role in the pathogenesis of NASH. Salvia-Nelumbinis naturalis (SNN), a formula of Traditional Chinese Medicine, has been identified to be effective for NASH, but the mechanisms were not thoroughly explored. In the present study, a NASH model was generated using C57BL/6 mice fed a high fat diet (HFD) supplemented periodically with dextran sulfate sodium (DSS) in drinking water for 12 weeks. Mice fed HFD alone (without DSS) or chow diet were used as controls. The NASH mice were given the SNN extracts in the following 4 weeks, while control mice were provided with saline. Mice fed HFD developed steatosis, and DSS supplementation resulted in NASH. The SNN extracts significantly improved metabolic disorders including obesity, dyslipidemia, and liver steatosis and reduced hepatic inflammation, circulating tumor necrosis factor-α (TNF-α), and lipopolysaccharide (LPS) levels. The beneficial effect of the SNN extracts was associated with restoration of intestinal conditions (microbiota, integrity of intestinal barrier) and inhibition of TLR4/NF-κB activation. These results suggest that the SNN extracts ameliorate NASH progression, possibly through blocking endotoxin related TLR4/NF-κB activation.

Immune Dysfunction in Cirrhosis

Cirrhosis due to any etiology disrupts the homeostatic role of liver in the body. Cirrhosis-associated immune dysfunction leads to alterations in both innate and acquired immunity, due to defects in the local immunity of liver as well as in systemic immunity. Cirrhosis-associated immune dysfunction is a dynamic phenomenon, comprised of both increased systemic inflammation and immunodeficiency, and is responsible for 30% mortality. It also plays an important role in acute as well as chronic decompensation. Immune paralysis can accompany it, which is characterized by increase in anti-inflammatory cytokines and suppression of proinflammatory cytokines. There is also presence of increased gut permeability, reduced gut motility and altered gut flora, all of which leads to increased bacterial translocation. This increased bacterial translocation and consequent endotoxemia leads to increased blood stream bacterial infections that cause systemic inflammatory response syndrome, sepsis, multiorgan failure and death. The gut microbiota of cirrhotic patients has more pathogenic microbes than that of non-cirrhotic individuals, and this disturbs the homeostasis and favors gut translocation. Prompt diagnosis and treatment of such infections are necessary for better survival. We have reviewed the various mechanisms of immune dysfunction and its consequences in cirrhosis. Recognizing the exact pathophysiology of immune dysfunction will help treating clinicians in avoiding its complications in their patients and can lead to newer therapeutic interventions and reducing the morbidity and mortality rates.

Potentiation of hepatic stellate cell activation by extracellular ATP is dependent on P2X7R-mediated NLRP3 inflammasome activation

Purinergic receptor P2x7 (P2x7R) is a key modulator of liver inflammation and fibrosis. The present study aimed to investigate the role of P2x7R in hepatic stellate cells activation. Lipopolysaccharide (LPS) or the conditioned medium (CM) from LPS-stimulated RAW 264.7 mouse macrophages was supplemented to human hepatic stellate cells, LX-2 for 24h and P2x7R selective antagonist A438079 (10μM) was supplemented to LX-2 cells 1h before LPS or CM stimulation. In addition LX-2 cells were primed with LPS for 4h and subsequently stimulated for 30min with 3mM of adenosine 5'-triphosphate (ATP). A438079 was supplemented to LX-2 cells 10min prior to ATP. Directly treated with LPS on LX-2 cells, mRNA expressions of interleukin (IL)-1β, IL-18 and IL-6 were increased, as well as mRNA expressions of P2x7R, caspase-1, apoptosis-associated speck-like protein containing CARD (ASC) and NOD-like receptor family, pyrin domain containing 3 (NLRP3) mRNA. LPS also increased α-smooth muscle actin (α-SMA) and type I collagen mRNA expressions, as well as collagen deposition. Interestingly treatment of LX-2 cells with LPS-activated CM exhibited the greater increase of above factors than those in LX-2 cells directly treated with LPS. Pretreatment of A438079 on LX-2 cells stimulated by LPS or LPS-activated CM both suppressed IL-1β mRNA expression. LPS combined with ATP dramatically increased protein synthesis and cleavage of IL-1β and its mRNA level than those in HSC treated with LPS or ATP alone. Additionally LX-2 cells primed with LPS and subsequently stimulated for 30min with ATP greatly increased mRNA and protein expression of caspase-1, NLRP3 and P2x7R, as well as liver fibrosis markers, α-SMA and type I collagen. These events were remarkably suppressed by A438079 pretreatment. siRNA against P2x7R reduced protein expression of NLRP3 and α-SMA, and suppressed deposition and secretion of type I collagen. The involvement of P2X7R-mediated NLRP3 inflammasome activation in IL-1β production of HSC might contribute to ECM deposition and suggests that blockade of the P2x7R-NLRP3 inflammasome axis represents a potential therapeutic target to liver fibrosis.

The Deficiency of Indoleamine 2,3-Dioxygenase Aggravates the CCl4-Induced Liver Fibrosis in Mice

In the present study, we examined the role of indoleamine 2,3-dioxygenase (IDO) in the development of CCl4-induced hepatic fibrosis. The liver fibrosis induced by repetitive administration with CCl4 was aggravated in IDO-KO mice compared to WT mice. In IDO-KO mice treated with CCl4, the number of several inflammatory cells and the expression of pro-inflammatory cytokines increased in the liver. In the results, activated hepatic stellate cells (HSCs) and fibrogenic factors on HSCs increased after repetitive CCl4 administration in IDO-KO mice compared to WT mice. Moreover, the treatment with l-tryptophan aggravated the CCl4-induced hepatic fibrosis in WT mice. Our findings demonstrated that the IDO deficiency enhanced the inflammation in the liver and aggravated liver fibrosis in repetitive CCl4-treated mice.

Metabolic derivatives of alcohol and the molecular culprits of fibro-hepatocarcinogenesis: Allies or enemies?

Chronic intake of alcohol undoubtedly overwhelms the structural and functional capacity of the liver by initiating complex pathological events characterized by steatosis, steatohepatitis, hepatic fibrosis and cirrhosis. Subsequently, these initial pathological events are sustained and ushered into a more complex and progressive liver disease, increasing the risk of fibro-hepatocarcinogenesis. These coordinated pathological events mainly result from buildup of toxic metabolic derivatives of alcohol including but not limited to acetaldehyde (AA), malondialdehyde (MDA), CYP2E1-generated reactive oxygen species, alcohol-induced gut-derived lipopolysaccharide, AA/MDA protein and DNA adducts. The metabolic derivatives of alcohol together with other comorbidity factors, including hepatitis B and C viral infections, dysregulated iron metabolism, abuse of antibiotics, schistosomiasis, toxic drug metabolites, autoimmune disease and other non-specific factors, have been shown to underlie liver diseases. In view of the multiple etiology of liver diseases, attempts to delineate the mechanism by which each etiological factor causes liver disease has always proved cumbersome if not impossible. In the case of alcoholic liver disease (ALD), it is even more cumbersome and complicated as a result of the many toxic metabolic derivatives of alcohol with their varying liver-specific toxicities. In spite of all these hurdles, researchers and experts in hepatology have strived to expand knowledge and scientific discourse, particularly on ALD and its associated complications through the medium of scientific research, reviews and commentaries. Nonetheless, the molecular mechanisms underpinning ALD, particularly those underlying toxic effects of metabolic derivatives of alcohol on parenchymal and non-parenchymal hepatic cells leading to increased risk of alcohol-induced fibro-hepatocarcinogenesis, are still incompletely elucidated. In this review, we examined published scientific findings on how alcohol and its metabolic derivatives mount cellular attack on each hepatic cell and the underlying molecular mechanisms leading to disruption of core hepatic homeostatic functions which probably set the stage for the initiation and progression of ALD to fibro-hepatocarcinogenesis. We also brought to sharp focus, the complex and integrative role of transforming growth factor beta/small mothers against decapentaplegic/plasminogen activator inhibitor-1 and the mitogen activated protein kinase signaling nexus as well as their cross-signaling with toll-like receptor-mediated gut-dependent signaling pathways implicated in ALD and fibro-hepatocarcinogenesis. Looking into the future, it is hoped that these deliberations may stimulate new research directions on this topic and shape not only therapeutic approaches but also models for studying ALD and fibro-hepatocarcinogenesis.

Epithelial to mesenchymal transition in the liver field: the double face of Everolimus in vitro

Background

Everolimus (EVE), a mammalian target of rapamycin inhibitor, has been proposed as liver transplant immunosuppressive drug, gaining wide interest also for the treatment of cancer. Although an appropriate tolerance, it may induce several adverse effects, such as fibro-interstitial pneumonitis due to the acquisition of activated myofibroblasts. The exact molecular mechanism associated with epithelial to mesenchymal transition (EMT) may be crucial also in the liver context. This work examines the role and the molecular mediators of EMT in hepatic stellate cell (HSC) and human liver cancer cells (HepG2) and the potential role of EVE to maintain the epithelial phenotype rather than to act as a potential initiators of EMT.

Methods

Real time-PCR and western blot have been used to assess the capability of EVE at low-therapeutic (10 nM) and high (100 nM) dose to induce an in vitro EMT in HSC and HepG2.

Results

Biomolecular experiments demonstrated that low concentration of EVE (10 nM) did not modify the gene expression of alpha-smooth muscle actin (α-SMA), Vimentin (VIM), Fibronectin (FN) in both HSC and HepG2 cells, whereas EVE at 100 nM induced a significant over-expression of all the three above-mentioned genes and an increment of α-SMA and FN protein levels. Additionally, 100 nM of EVE induced a significant phosphorylation of AKT and an up-regulation of TGF-β expression in HSC and HepG2 cells.

Discussion

Our data, although obtained in an in vitro model, revealed, for the first time, that high concentration of EVE may induce EMT in liver cells confirming previous published evidences obtained in renal cells. Additionally, they suggested that mTOR-I should be administered at the lowest dose able to maximize their important and specific therapeutic properties minimizing or avoiding fibrosis-related adverse effects.

Conclusions

In summary, if confirmed by additional studies, our results could be useful for researchers to standardize new therapeutic immunosuppressive and anticancer drugs protocols.

Isolation and time lapse microscopy of highly pure hepatic stellate cells

Hepatic stellate cells (HSC) are the main effector cells for liver fibrosis. We aimed at optimizing HSC isolation by an additional step of fluorescence-activated cell sorting (FACS) via a UV laser. HSC were isolated from livers of healthy mice and animals subjected to experimental fibrosis. HSC isolation by iohexol- (Nycodenz) based density centrifugation was compared to a method with subsequent FACS-based sorting. We assessed cellular purity, viability, morphology, and functional properties like proliferation, migration, activation marker, and collagen expression. FACS-augmented isolation resulted in a significantly increased purity of stellate cells (>99%) compared to iohexol-based density centrifugation (60–95%), primarily by excluding doublets of HSC and Kupffer cells (KC). Importantly, this method is also applicable to young animals and mice with liver fibrosis. Viability, migratory properties, and HSC transdifferentiation in vitro were preserved upon FACS-based isolation, as assessed using time lapse microscopy. During maturation of HSC in culture, we did not observe HSC cell division using time lapse microscopy. Strikingly, FACS-isolated, differentiated HSC showed very limited molecular and functional responses to LPS stimulation. In conclusion, isolating HSC from mouse liver by additional FACS significantly increases cell purity by removing contaminations from other cell populations especially KC, without affecting HSC viability, migration, or differentiation.

The tyrosine phosphatase SHP-1 inhibits proliferation of activated hepatic stellate cells by impairing PDGF receptor signaling

The dimerization and auto-transphosphorylation of platelet-derived growth factor receptor (PDGFR) upon engagement by platelet-derived growth factor (PDGF) activates signals promoting the mitogenic response of hepatic stellate cells (HSCs) due to liver injury, thus contributing to the development of hepatic fibrosis. We demonstrate that the tyrosine phosphatases Src homology 2 domain-containing phosphatase 1 and 2 (SHP-1 and SHP-2) act as crucial regulators of a complex signaling network orchestrated by PDGFR activation in a spatio-temporal manner with diverse and opposing functions in HSCs. In fact, silencing of either phosphatase shows that SHP-2 is committed to PDGFR-mediated cell proliferation, whereas SHP-1 dephosphorylates PDGFR hence abrogating the downstream signaling pathways that result in HSC activation. In this regard, SHP-1 as an off-switch of PDGFR signaling appears to emerge as a valuable molecular target to trigger as to prevent HSC proliferation and the fibrogenic effects of HSC activation. We show that boswellic acid, a multitarget compound with potent anti-inflammatory action, exerts an anti-proliferative effect on HSCs, as in other cell models, by upregulating SHP-1 with subsequent dephosphorylation of PDGFR-β and downregulation of PDGF-dependent signaling after PDGF stimulation. Moreover, the synergism resulting from the combined use of boswellic acid and imatinib, which directly inhibits PDGFR-β activity, on activated HSCs offers new perspectives for the development of therapeutic strategies that could implement molecules affecting diverse players of this molecular circuit, thus paving the way to multi-drug low-dose regimens for liver fibrosis.

Tacrolimus (FK506) prevents early stages of ethanol induced hepatic fibrosis by targeting LARP6 dependent mechanism of collagen synthesis

Tacrolimus (FK506) is a widely used immunosuppressive drug. Its effects on hepatic fibrosis have been controversial and attributed to immunosuppression. We show that in vitro FK506, inhibited synthesis of type I collagen polypeptides, without affecting expression of collagen mRNAs. In vivo, administration of FK506 at a dose of 4 mg/kg completely prevented development of alcohol/carbon tetrachloride induced liver fibrosis in rats. Activation of hepatic stellate cells (HSCs) was absent in the FK506 treated livers and expression of collagen α2(I) mRNA was at normal levels. Collagen α1(I) mRNA was increased in the FK506 treated livers, but this mRNA was not translated into α1(I) polypeptide. No significant inflammation was associated with the fibrosis model used. FK506 binding protein 3 (FKBP3) is one of cellular proteins which binds FK506 with high affinity. We discovered that FKBP3 interacts with LARP6 and LARP6 is the major regulator of translation and stability of collagen mRNAs. In the presence of FK506 the interaction between FKBP3 and LARP6 is weakened and so is the pull down of collagen mRNAs with FKBP3. We postulate that FK506 inactivates FKBP3 and that lack of interaction of LARP6 and FKBP3 results in aberrant translation of collagen mRNAs and prevention of fibrosis. This is the first report of such activity of FK506 and may renew the interest in using this drug to alleviate hepatic fibrosis.

Immunohistochemical Characterization of Macrophages and Myofibroblasts in α-Naphthylisothiocyanate (ANIT)–Induced Bile Duct Injury and Subsequent Fibrogenesis in Rats

To investigate pathogenesis of post–bile duct (BD) injury fibrosis, interlobular BD epithelial injury was induced in male F344 rats by a single IP injection of α-naphthylisothiocyanate (75 mg/kg body weight) and rats were observed for 12 days. On days 1 to 2, cholangiocytes were injured and desquamated. On days 3 to 5, the affected BD began to regenerate, showing positive staining for CK19 and vimentin. On days 5 to 9, fibrotic areas gradually developed around regenerating BD in Glisson’s sheath. These consisted of cells positive for vimentin, desmin, and α-SMA; vimentin- and desmin-positive cells were increased in early stage (days 1–3), whereas α-SMA-positive cells appeared in mid (days 4–7) and late stages (days 8–12), although there were cells coexpressing these cytoskeletons. On day 12, BD regeneration almost completed, with reduced fibrosis. Macrophages positive for ED2 (CD163) increased transiently in early stage, whereas those reacting to ED1 (CD68), OX6 (MHC II), and SRA-E5 (CD204) showed a consistent increase throughout the experiment. Interestingly, OX6-positive cells were limited to Glisson’s sheath, whereas SRA-E5-positive cells were seen exclusively along sinusoids of hepatic lobules. MCP-1 mRNA increased significantly in early stage. This study shows that macrophages exhibiting different immunophenotypes and distributions participate in post-BD injury fibrosis associated with myofibroblasts expressing various mesenchymal cytoskeletons.

Macrophages and tissue injury: agents of defense or destruction?

The past several years have seen the accumulation of evidence demonstrating that tissue injury induced by diverse toxicants is due not only to their direct effects on target tissues but also indirectly to the actions of resident and infiltrating macrophages. These cells release an array of mediators with cytotoxic, pro- and anti-inflammatory, angiogenic, fibrogenic, and mitogenic activity, which function to fight infections, limit tissue injury, and promote wound healing. However, following exposure to toxicants, macrophages can become hyperresponsive, resulting in uncontrolled or dysregulated release of mediators that exacerbate acute tissue injury and/or promote the development of chronic diseases such as fibrosis and cancer. Evidence suggests that the diverse activity of macrophages is mediated by distinct subpopulations that develop in response to signals within their microenvironment. Understanding the precise roles of these different macrophage populations in the pathogenic response to toxicants is key to designing effective treatments for minimizing tissue damage and chronic disease and for facilitating wound repair.

Participation of Functionally Different Macrophage Populations and Monocyte Chemoattractant Protein-1 in Early Stages of Thioacetamide-induced Rat Hepatic Injury

Macrophages are crucial in hepatic fibrogenesis. In acute hepatic necrosis induced in rats by a single injection of 300 mg/kg body weight (BW) of thioacetamide (TAA), macrophage properties were investigated using single or double immunohistochemistry. Macrophages reacting with anti-CD68, anti-CD163, or major histocompatibility complex (anti-MHC) class II antibody appeared in injured centrilobular areas on days 1-5 after injection. Increased expression of CD68 and CD163 reflect phagocytosis and production of pro-inflammatory factors, respectively. There were also macrophages double-positive to CD68/CD163, CD68/MHC class II, or CD163/MHC class II; of these, macrophages double-positive to CD68/MHC class II were most frequent, indicating that macrophages with enhanced phagocytic activity came to express MHC class II. The appearance of these macrophages corresponded to increased expression of mRNAs of monocyte chemoattractant protein-1 (MCP-1), a chemokine, on day 1, and TGF-β1, a fibrogenic factor, on day 3. Some hepatic stellate cells (HSCs) in injured areas reacted with anti-MCP-1 antibody. To investigate the effects of MCP-1, we added MCP-1 to HS-P, a rat macrophage line. Addition of MCP-1 increased immunoexpression for CD68 and CD163 and up-regulated TGF-β1 mRNA expression. Collectively, macrophages in acute hepatic necrosis may express different properties such as phagocytosis, MHC class II expression, and TGF-β1 production; such expression may be influenced by MCP-1 produced by HSCs.

Alcohol metabolites and lipopolysaccharide: roles in the development and/or progression of alcoholic liver disease

The onset of alcoholic liver disease (ALD) is initiated by different cell types in the liver and a number of different factors including: products derived from ethanol-induced inflammation, ethanol metabolites, and the indirect reactions from those metabolites. Ethanol oxidation results in the production of metabolites that have been shown to bind and form protein adducts, and to increase inflammatory, fibrotic and cirrhotic responses. Lipopolysaccharide (LPS) has many deleterious effects and plays a significant role in a number of disease processes by increasing inflammatory cytokine release. In ALD, LPS is thought to be derived from a breakdown in the intestinal wall enabling LPS from resident gut bacterial cell walls to leak into the blood stream. The ability of adducts and LPS to independently stimulate the various cells of the liver provides for a two-hit mechanism by which various biological responses are induced and result in liver injury. Therefore, the purpose of this article is to evaluate the effects of a two-hit combination of ethanol metabolites and LPS on the cells of the liver to increase inflammation and fibrosis, and play a role in the development and/or progression of ALD.

S-adenosyl-L-methionine attenuates oxidative stress and hepatic stellate cell activation in an ethanol-LPS-induced fibrotic rat model

Previous studies report S-adenosyl-L-methionine (SAMe) can exert hepatoprotective effects. At present, the role of SAMe in affecting the activation and/or proliferation of hepatic stellate cells (HSCs) during alcohol-induced fibrotic disease progression is poorly understood. In the human disease state, chronic ethanol intake increases hepatic exposure to LPS and magnifies the hepatic insult leading to fibrosis and cirrhosis. In this study, we developed a "2-hit" ethanol-LPS fibrotic liver rat model with which to investigate the effects of SAMe as a hepatic antifibrotic treatment. Male rats were maintained on liquid diets containing either ethanol or isocalorically matched controls for 8 weeks. Animals received ethanol alone (E), ethanol concomitant with twice weekly LPS injections (EL), or ethanol, LPS, and daily SAMe injections. When using this model, SAMe-treated animals demonstrated significantly decreased fibrosis, oxidative stress, steatosis, and improved liver function versus the EL group. In addition, the EL group showed increased HSC activation, an effect that was abrogated by the addition of SAMe. Analysis of the transforming growth factor-beta (TGF-beta) signaling pathways demonstrated increased hepatic TGF-beta and Smad3 messenger RNA expression in the E and EL groups, which was inhibited in the presence of SAMe. Conversely, SAMe led to increased Smad7 (an inhibitor of TGF-beta signaling) messenger RNA expression. These data demonstrate chronic ethanol feeding combined with LPS induces liver fibrosis, and the addition of SAMe significantly reduces hepatic injury and fibrosis through inhibition of oxidative stress and HSC activation.

Resolution of liver cirrhosis using vitamin A-coupled liposomes to deliver siRNA against a collagen-specific chaperone

There are currently no approved antifibrotic therapies for liver cirrhosis. We used vitamin A-coupled liposomes to deliver small interfering RNA (siRNA) against gp46, the rat homolog of human heat shock protein 47, to hepatic stellate cells. Our approach exploits the key roles of these cells in both fibrogenesis as well as uptake and storage of vitamin A. Five treatments with the siRNA-bearing vitamin A-coupled liposomes almost completely resolved liver fibrosis and prolonged survival in rats with otherwise lethal dimethylnitrosamine-induced liver cirrhosis in a dose- and duration-dependent manner. Rescue was not related to off-target effects or associated with recruitment of innate immunity. Receptor-specific siRNA delivery was similarly effective in suppressing collagen secretion and treating fibrosis induced by CCl(4) or bile duct ligation. The efficacy of the approach using both acute and chronic models of liver fibrosis suggests its therapeutic potential for reversing human liver cirrhosis.

Experimental study of herbal-based medicine Hong Tian Gan Kang on the intervention and therapy for hepatic cirrhosis

AIM: To investigate the prevention and treatment of Hong Tian Gan Kang (HTGK) on experimental hepatic cirrhosis.

METHODS: The female ICR mice were allocated into traditional Chinese medicine (HTGK) prevention group, treatment group, animal model group, and control group. During the process of inducing hepatocirrhosis by CCl4 celiac injection in ICR mice, the HTGK group received HTGK per day, while the model group was created into the animal model by the above means without treatment. The mice of control group were normally raised without being created into models. The control group, animal model group and (HTGK) prevention group were sacrificed randomly at the end of the 60 d, 90 d and 180 d; while treatment group was sacrificed randomly at the end of the 30 d, 60 d and 90 d. Tissue specimens were taken. Animals received liver histopathology and ultrastructure test.

RESULTS: Up to day 180, marked hepatic fatty changes, inflammation, necrosis and fibrosis were observed in mice of model group. In contrast, these alternations were attenuated by HTGK administration although mild fatty changes remained. Compared with the CCl4-induced cirrhotic mice, histological changes of fibrosis were improved significantly in the mice treated with HTGK. Liver histopathology showed that the contents of transforming growth factor-β1 (TGF-β1) and alpha-smooth muscle actin (α-SMA) in the animal model group were significantly higher than those in the control group (TGF-β1, 60 d: 0.269 vs 0.155; 90 d: 0.306 vs 0.155; 180 d: 0.336 vs 0.160; α-SMA, 60 d: 0.269 vs 0.160; 90 d: 0.299 vs 0.150; 180 d: 0.322 vs 0.155, P < 0.01). However, the contents of TGF-β1 and α-SMA in the therapy group were significantly lower than those in the model group (0.220, 0.203, 0.185 vs 0.336, P < 0.01; 0.2451, 0.2113, 0.185 vs 0.3217, P < 0.01).

CONCLUSION: HTGK has suppressive, preventive and curative effect on hepatic fibrosis and hepatocirrhosis.

Cross-talk between PDGF and S1P signalling elucidates the inhibitory effect and potential antifibrotic action of the immunomodulator FTY720 in activated HSC-cultures

Platelet-derived growth factor (PDGF) has been shown to be essential in the activation of hepatic stellate cells (HSCs), contributing to the onset and development of hepatic fibrosis. Recently, sphingosine-1-phosphate (S1P) has been shown to be a mitogen and stimulator of chemotaxis also for HSCs. Since it has been demonstrated in several cell types that cross-talk between PDGF and S1P signalling pathways occurs, our aim was to investigate the potential antifibrotic effect of FTY720, whose phosphorylated form acts as a potent S1P receptor (S1PR) modulator, on HSCs. FTY720 inhibits cell proliferation and migration after PDGF stimulation on HSCs in a concentration range between 0.1 and 1 muM. By using compounds that block S1P signalling (PTX and VPC23019), we assessed that FTY720 also acts in an S1P receptor-independent way by decreasing the level of tyrosine phosphorylation of PDGF receptor, with subsequent inhibition of the PDGF signalling pathway. In addition, inhibition of sphingosine kinase2 (SphK2), which is responsible for FTY720 phosphorylation, by DMS/siRNA unveils a mechanism of action irrespective of its phosphorylation, in particular decreasing the level of S1P(1) on the plasma membrane. These findings led us to hypothesize a potential use of FTY720 as a potential antifibrotic drug for further clinical application.

Liver fibrosis: a balance of ACEs?

There is an increasing body of evidence to suggest that the RAS (renin–angiotensin system) contributes to tissue injury and fibrosis in chronic liver disease. A number of studies have shown that components of a local hepatic RAS are up-regulated in fibrotic livers of humans and in experimental animal models. Angiotensin II, the main physiological effector molecule of this system, mediates liver fibrosis by stimulating fibroblast proliferation (myofibroblast and hepatic stellate cells), infiltration of inflammatory cells, and the release of inflammatory cytokines and growth factors such as TGF (transforming growth factor)-β1, IL (interleukin)-1β, MCP (monocyte chemoattractant protein)-1 and connective tissue growth factor. Furthermore, blockade of the RAS by ACE (angiotensin-converting enzyme) inhibitors and angiotensin type 1 receptor antagonists significantly attenuate liver fibrosis in experimental models of chronic liver injury. In 2000 ACE2 (angiotensin-converting enzyme 2), a human homologue of ACE, was identified. ACE2 efficiently degrades angiotensin II to angiotensin-(1–7), a peptide which has recently been shown to have both vasodilatory and tissue protective effects. This suggests that ACE2 and its products may be part of an alternate enzymatic pathway in the RAS, which counterbalances the generation and actions of angiotensin II, the ACE2–angiotensin-(1–7)–Mas axis. This review focuses on the potential roles of the RAS, angiotensin II and ACE2 in chronic liver injury and fibrogenesis.

Paeoniflorin inhibits TGF-beta1-mediated collagen production by Schistosoma japonicum soluble egg antigen in vitro

The main pathological characteristics of hepatic fibrosis in schistosomiasis are the proliferation of hepatic stellate cells (HSCs) and the deposition of collagen type I (Col I) and collagen type III (Col III). Transforming growth factor beta-1 (TGF-beta1) plays an important role in hepatic fibrosis. Paeoniflorin (PAE) has been reported to have immunoregulatory effects; however, the mechanism of its anti-hepatic fibrosis in S. japonicum has not been elucidated. In the present study, we found that mouse peritoneal macrophages (PMphis) stimulated by soluble egg antigen (SEA) of S. japonicum could secrete TGF-beta1, and the TGF-beta1 in the peritoneal macrophage-conditioned medium (PMCM) could induce proliferation of HSCs and secretion of Col I and III. We selected PMCM at 1 : 2 dilution as the optimum PMCM (OPMCM). Then we treated HSCs pre-incubated with OPMCM with PAE, and found that the inhibition of HSC proliferation or Col I and III production were closely correlated with the concentration of PAE. Further investigation found that PAE significantly decreased the Smad3 transcription and phosphorylation in HSCs stimulated by OPMCM. In conclusion, SEA plays a key role in hepatic fibrosis by inducing TGF-beta1 from PMphis. PAE can exert anti-fibrogenic effects by inhibiting HSCs proliferation and down-regulating Smad3 expression and phosphorylation through TGF-beta1 signalling.

Pattern recognition receptors: a contemporary view on liver diseases

Pattern recognition receptors (PRRs) function as sensors of microbial danger signals enabling the vertebrate host to initiate an immune response. PRRs are present not only in immune cells but also in liver parenchymal cells and the complexity of the cell populations provide unique aspects to pathogen recognition and tissue damage in the liver. This review discusses the role of different PRRs in pathogen recognition in the liver, and focuses on the role of PRRs in hepatic inflammation, cholestasis, ischemia, repair and fibrosis. PRRs as novel therapeutic targets are evaluated.

Kupffer cells abrogate cholestatic liver injury in mice

BACKGROUND & AIMS

Biliary obstruction and cholestasis can cause hepatocellular apoptosis and necrosis. Ligation of the common bile duct in mice provides an excellent model in which to study the underlying mechanisms. Kupffer cells play a key role in modulating the inflammatory response observed in most animal models of liver injury. This study was performed to determine the role of Kupffer cells in the injury attending cholestasis.

METHODS

Mice were not treated or were rendered Kupffer cell-depleted by intravenous inoculation of multilamellar liposome-encapsulated dichloromethylene diphosphonate, the common bile duct was ligated and divided; sham-operated animals served as controls. Similarly, interleukin-6 (IL-6)-deficient and tumor necrosis factor-receptor-deficient mice underwent bile duct ligation (BDL) or sham operations.

RESULTS

Serum alanine transaminase levels were increased in all BDL mice at 3 days after surgery, but were significantly higher in IL-6-deficient mice or mice rendered Kupffer cell-depleted before ligation. Histologic examination of BDL livers showed portal inflammation, neutrophil infiltration, bile duct proliferation, and hepatocellular necrosis. Photoimage analyses confirmed more necrosis in the livers of Kupffer cell-depleted and IL-6-deficient animals. Purified Kupffer cells derived from BDL animals produced more IL-6 in culture. Similarly, Kupffer cells obtained by laser capture microdissection from the livers of BDL mice expressed increased levels of IL-6 messenger RNA. Recombinant mouse IL-6 administered 1 hour before BDL completely reversed the increased liver damage assessed otherwise in Kupffer cell-depleted mice.

CONCLUSIONS

These findings indicate that Kupffer cells abrogate cholestatic liver injury by cytokine-dependent mechanisms that include the production of IL-6.

Ultrastructure of Kupffer cells and hepatocytes in the Dubin-Johnson syndrome: A case report

Ultrastructure of Kupffer cells and hepatocytes in liver bioptate was evaluated in a 17-year-old boy with Dubin–Johnson syndrome (DJS). The liver tissue obtained by needle biopsy was fixed in glutaraldehyde and paraformaldehyde and routinely processed for electron microscopic analysis. The ultrastructural examinations of liver bioptate revealed the accumulation of membrane-bound, electron-dense lysosomal granules within the cytoplasm of hepatocytes, characteristic of DJS. They were located mainly in the vicinity of the biliary pole, and preferentially in the centrilobular region that corresponded to the pigment deposits seen under light microscope. The presence of the granules was accompanied by dilated elements of the granular endoplasmic reticulum and paracrystalline mitochondrial inclusions as well as dilation of the bile canaliculi. The changes in hepatocytes co-existed with marked stimulation and enhanced phagocytic activity of Kupffer cells. This was manifested in the accumulation of pigment deposits within their cytoplasm that corresponded to those observed in hepatocytes. Hyperactive pericentral Kupffer cells which are involved in the response to pigmentary material originating from disintegrated hepatocytes may play an essential role in the development of DJS.

Pathological mechanisms of alcohol-induced hepatic portal hypertension in early stage fibrosis rat model

AIM: To study the role of hepatic sinusoidal capillarization and perisinusoidal fibrosis in rats with alcohol-induced portal hypertension and to discuss the pathological mechanisms of alcohol-induced hepatic portal hypertension.

METHODS: Fifty SD rats were divided into control group (n=20) and model group (n=30). Alcoholic liver fibrosis rat model was induced by intragastric infusion of a mixture containing alcohol, corn oil and pyrazole (1 000:250:3). Fifteen rats in each group were killed at wk 16. The diameter and pressure of portal vein were measured. Plasma hyaluronic acid (HA), type IV collagen (CoIV) and laminin (LN) were determined by radioimmunoassay. Liver tissue was fixed in formalin (10%) and 6-μm thick sections were routinely stained with Mallory and Sirius Red. Liver tissue was treated with rabbit polyclonal antibody against LN and ColIV. Hepatic non-parenchymal cells were isolated, total protein was extracted and separated by SDS-PAGE. MMP-2 and TIMP-1 protein expression was estimated by Western blotting.

RESULTS: The diameter (2.207 ± 0.096 vs 1.528 ± 0.054 mm, P<0.01) and pressure (11.014±0.395 vs 8.533±0.274 mmHg, P<0.01) of portal vein were significantly higher in model group than those in the control group. Plasma HA (129.97±16.10 vs 73.09±2.38 ng/mL, P<0.01), ColIV (210.49±4.36 vs 89.65±4.42 ng/mL, P<0.01) and LN (105.00±7.29 vs 55.70±4.32 ng/mL, P<0.01) were upregulated in model group. Abundant collagen deposited around the central vein of lobules, hepatic sinusoids and hepatocytes in model group. ColI and ColIII increased remarkably and perisinusoids were almost surrounded by ColIII. Immunohistochemical staining showed that ColIV protein level (0.130±0.007 vs 0.032±0.004, P<0.01) and LN protein level (0.152±0.005 vs 0.029±0.005, P<0.01) were up-regulated remarkably in model group. MMP-2 protein expression (2.306±1.089 vs 0.612±0.081, P<0.01) and TIMP-1 protein expression (3.015±1.364 vs 0.446±0.009, P<0.01) in freshly isolated hepatic non-parenchymal cells were up-regulated in model group and TIMP-1 protein expression was evidently higher than MMP-2 protein expression (2.669±0.170 vs 1.695±0.008, P<0.05).

CONCLUSION: Hepatic sinusoidal capillarization and peri-sinusoidal fibrosis are responsible for alcohol-induced portal hypertension in rats.

Effect of Astragalus complanatus flavonoid on anti-liver fibrosis in rats

AIM: To observe the anti-liver fibrosis effect of Astragalus complanatus flavonoids (ACF) in rats.

METHODS: The liver fibrosis model in rats was established by injecting interperitoneally 0.2 mL/100 g 0.5% dimethylnitrosamine, thrice a week. Meanwhile, the rats were administered ACF (30, 60, 120 mg/kg) or colchicine (0.1 mg/kg) once a day for 1 mo. Serum N-propeptide of type I procollagen (PINP) and type III procollagen (PIIINP) was measured using ELISA. Malondialdehyde (MDA) and superoxide dismutase (SOD) in hepatic tissue were evaluated. Matrix metal protease-1 (MMP-1) mRNA expression was assayed by RT-PCR and the protein expression of tissue inhibitor of metal protease-1 (TIMP-1) was analyzed by immunohistochemistry.

RESULTS: In the ACF groups, SOD activity increased and MDA content decreased in comparison to the liver fibrosis model group. The serum PINP and PIIINP contents in ACF-2 and -3 group decreased compared to those in model group. In ACF-2 and -3 group, the expression of MMP-1 mRNA increased significantly and the protein expression of TIMP-1 decreased compared to that in model group.

CONCLUSION: The antifibrotic mechanisms of ACF are associated with its influence on lipid peroxidation and collagen synthesis and degradation.

Exposure to bacterial cell wall products triggers an inflammatory phenotype in hepatic stellate cells

Activated hepatic stellate cells (HSCs) secrete extracellular matrix components during hepatic fibrosis, but recent studies have shown that HSCs can also release a variety of proinflammatory cytokines. Moreover, bacterial endotoxemia is not only associated with systemic complications in the late stages of liver failure but is also a direct cause of liver damage, activating resident inflammatory cells. In this study, we investigated whether HSCs can respond directly to bacterial cell wall products acquiring a new phenotype. RT-PCR and immunocytochemistry assays were used to show that murine HSCs expressed specific mRNA transcripts and proteins for LPS and lipoteichoic acid (LTA) receptor systems and peptidoglycan recognition proteins. Exposing HSCs to bacterial endotoxins led to phosphorylation of mitogen-activated protein kinase ERK1 and the development of a proinflammatory phenotype. After exposure to LPS, LTA, or N-acetyl muramyl peptide, transforming growth factor-beta1, IL-6, and monocyte chemoattractant protein-1 (MCP-1) mRNA specific transcripts and proteins increased significantly in HSCs, as assayed by quantitative real-time RT-PCR and ELISA. These LPS-mediated effects in HSCs were receptor dependent, because LPS-induced ERK1 phosphorylation, IL-6, and MCP-1 mRNA and protein level upregulation were significantly less pronounced in HSCs isolated from C3H/HeJ mice lacking Toll-like receptor 4. In conclusion, our results show that murine HSCs express functional receptors for bacterial endotoxins, and HSCs exposed to bacterial products develop a strong proinflammatory phenotype. We speculate that high levels of bacterial endotoxins in the portal vein may directly induce a proinflammatory phenotype in HSCs that contributes to liver damage.

CD14-positive hepatic monocytes/macrophages increase in hereditary hemochromatosis

BACKGROUND/AIMS

Iron overload in hereditary hemochromatosis (HH) may result in hepatic fibrosis and cirrhosis, primarily due to collagen production by hepatic stellate cells that become activated to myofibroblasts. Endotoxin-responsive monocytes/macrophages (CD14-positive) are potential sources of profibrogenic factors. The aims of this study were to determine (1) whether CD14-positive monocytes/macrophages are present in the livers of patients with HH and (2) the potential relationship between CD14-positive cells and hepatic fibrosis in HH.

METHODS

HH was diagnosed using standard clinical, biochemical and genotypic parameters. Liver specimens from HH patients and control subjects were immunostained for CD14, CD68 and alpha-smooth muscle actin (alpha-SMA) and the number of cells expressing these antigens was determined. Fibrosis was assessed by routine histological methods.

RESULTS

The total number of hepatic CD68-positive monocytes/macrophages was similar in HH patients and control subjects; however, there was a nine-fold increase in the number of CD14-positive monocytes/macrophages in HH patients. Control subjects had very low levels of hepatic CD14 expression. In HH livers with advanced fibrosis, CD14-positive monocytes/macrophages were often associated with fibrous septa containing myofibroblasts expressing alpha-SMA.

CONCLUSIONS

There was a substantial increase in hepatic CD14-positive monocytes/macrophages in HH and, in livers with advanced fibrosis, these cells were often associated with fibrous septa and septal myofibroblasts. The total number of monocytes/macrophages was similar in HH and control livers. In control human liver, Kupffer cells had a very low expression of CD14. These findings suggest that CD14-positive monocytes/macrophages may contribute to the process of hepatic fibrogenesis in HH.

Effect of losartan, an angiotensin II antagonist, on hepatic fibrosis induced by CCl4 in rats

In addition to regulating blood pressure and body fluid homeostasis, the renin-angiotensin system (RAS) is also involved in hepatic fibrogenesis. We aimed to investigate the effect of losartan, an angiotensin II (Ang II) antagonist, on CCl4-induced hepatic fibrosis in rats. Hepatic fibrosis was induced by a subcutaneous injection with 50% CCl4 in Sprague-Dawley rats. The amount of CCl4 administered was 1 mg/kg. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in plasma and hydroxyproline (Hyp) contents in liver tissue were assayed by spectrophotometry. Hyaluronic acid (HA) and procollagen III (PC III) were assessed by radioimmunoassay. Tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta1 (TGF-beta1) levels in culture supernatants of Kupffer cells (KCs) stimulated with Ang II was determined by ELISA. Liver samples collected after 12 weeks of CCl4 treatment were stained with hematoxylin and eosin, then scored. Losartan (2.5, 5, and 10 mg x kg(-1), ig) and captopril (100 mg x kg(-1), ig) significantly decreased liver and spleen indexes, serum transaminase (AST, ALT) activities, HA and PC III levels, and Hyp contents in liver tissue in rats of hepatic fibrosis. Histopathological scores showed that losartan had an inhibitory effect on the progression of hepatic fibrosis. In in vitro experiments, losartan (1 x 10(-9) - 1 x 10(-5) M) significantly reduced TNF-alpha and TGF-beta1 levels in culture supernatants of KCs, but captopril (1 x 10(-5) M) did not. The results showed that losartan significantly inhibited the progression of hepatic fibrosis induced by CCl4, and the inhibitory effect of losartan on hepatic fibrosis might be associated with its ability to inhibit the production of TNF-alpha and TGF-beta1 by activated KCs.

Effects of losartan on TIMP-1 and PAI-1 expression in rat hepatic fibrosis

AIM: To investigate the effect of losartan on the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and plasminogen activator inhibition-1 (PAI-1) in the liver of rat with hepatic fibrosis.

METHODS: Forty-eight SD rats were randomly divided into four groups: normal control group, model group, losartan-prevention group, losartan-treatment group. Except rats in control group, all rats were given subcutaneous injection of carbon tetrachloride. Rats in prevention and treatment (from the 5th wk) groups were also given losartan via gastrogavage. At the end of 12 weeks, rats were sacrificed. HE and VG stains were used to evaluate the degree of fibrosis; Immunohistochemistry was used to detect the expression of TIMP-1 and PAI-1 in the liver tissue, respectively.

RESULTS: Losartan could greatly attenuate the degree of liver fibrosis (P < 0.05) . Intensity score (IS) of TIMP-1 and PAI-1 in prevention (1.6 900±0.4 228, 1.8 900±0.5 127) and treatment (1.9 000±0.5 925, 2.0 540±0.4 251) groups was weaker than that in model group (2.5 111±0.3 919, 2.8 500±0.2 013) (P < 0.05).

CONCLUSION: Losartan can suppress expression of TIMP-1 and PAI-1, which may be related to its anti-hepatic fibrosis activity.

Therapeutic effect of valsartan on chronic type B hepatitis and liver cirrhosis

AIM: To study the clinical effect of valsartan on chronic type B hepatitis and liver cirrhosis.

METHODS: A total of 54 patients with chronic type B hepatitis and liver cirrhosis were divided into therapy group and control group, and each group had 27 cases. The patients in the control group were treated with routine treatment, and those in the therapy group, besides routine treatment, were added with valsartan 80 mg/day, and the therapeutic period was one month. Before and after treatment, serum HA, LN, PCIII, IV-C were measured by radio-immunoassay in each group. The parameters of ALT, AST, TBIL, Alb, r-GT and AKP were obtained. In the therapy group, five patients' liver tissues were obtained by liver biopsy, and then stained by H-E staining before and after treatment.

RESULTS: In these two groups, the parameters of ALT, AST, r-GT, AKP , TBIL, HA, and IV-C were all improved remarkably (P < 0.05 or 0.01) after treatment. In the therapy group, the parameters of ALT (5.7±1.9 ukat/L vs 1.3±0.7 ukat/L), AST (5.1±1.9 ukat/L vs 1.5±0.7 ukat/L), HA (298±107 ug/L vs 159±92 ug/L) and IV-C (102±24 ug/L vs 63±19 ug/L) were all descended (P < 0.05 or 0.01, 2.241≤t≤3.249) before and after treated with valsartan. Compared with control group, especially in chronic hepatitis patients, these parameters were decreased significantly (P < 0.05 or 0.01, 2.324 ≤ t ≤ 3.012), the liver microcirculation was improved, the inflammatory infiltration in liver was relieved, the liver tissue fibrosis was degraded, and the liver histology was remarkably improved.

CONCLUSION: As valsartan can effectively protect the liver cells, reverse the process of liver fibrosis, it is a feasible choice in the treatment of chronic hepatitis and liver cirrhosis.