Effects of the tyrosine protein kinase inhibitor genistein on the proliferation, activation of cultured rat hepatic stellate cells

EGF-receptor phosphorylation and downstream signaling are activated by genistein during subacute liver damage

The epidermal growth factor receptor (EGFR) plays an important role on hepatic protection in acute and chronic liver injury. The aim of this study was to investigate the role of genistein on EGFR expression, phosphorylation and signaling pathways in experimental subacute liver damage induced by carbon tetrachloride (CCl₄). We used male Wistar rats that were randomly divided into four groups: (1) Control; (2) Genistein 5 mg/kg per oral; (3) Subacute liver damage induced by CCl₄ 4 mg/kg subcutaneously; and (4) Animals received CCl₄ and genistein at the dosage indicated. The effect of genistein on EGFR expression, phosphorylation and signaling pathways were investigated by western blot and densitometric analyses. Histological changes were evaluated on slices stained with Hematoxylin-Eosin and Masson´s trichromic, as well as an immunohistochemical analysis for proliferating cell nuclear antigen (PCNA). Additionally, pro-inflammatory cytokines and liver enzymes were quantified. Our study showed that genistein increased EGFR expression, EGFR-specific tyrosine residues phosphorylation (pY1068-EGFR and pY84-EGFR), signal transducer and activator of transcription phosphorylation (pSTAT5), protein kinase B phosphorylation (pAKT) and PCNA in animals with CCl₄-induced subacute liver damage. It was found a significant reduction of pro-inflammatory cytokines in serum from animals with subacute liver damage treated with genistein. Those effects were reflected in an improvement in the architecture and liver function. In conclusion, genistein can induce a transactivation of EGFR leading to downstream cell signaling pathways as early events associated with regeneration and hepatoprotection following subacute liver damage.

N-n-Butyl haloperidol iodide ameliorates liver fibrosis and hepatic stellate cell activation in mice

N-n-Butyl haloperidol iodide (F₂) is a novel compound that has antiproliferative and antifibrogenic activities. In this study we investigated the therapeutic potential of F₂ against liver fibrosis in mice and the underlying mechanisms. Two widely used mouse models of fibrosis was established in mice by injection of either carbon tetrachloride (CCl₄) or thioacetamide (TAA). The mice received F₂ (0.75, 1.5 or 3 mg·kg^-1·d^-1, ip) for 4 weeks of fibrosis induction. We showed that F₂ administration dose-dependently ameliorated CCl₄- or TAA-induced liver fibrosis, evidenced by significant decreases in collagen deposition and c-Jun, TGF-β receptor II (TGFBR2), α-smooth muscle actin (α-SMA), and collagen I expression in the liver. In transforming growth factor beta 1 (TGF-β1)-stimulated LX-2 cells (a human hepatic stellate cell line) and primary mouse hepatic stellate cells, treatment with F₂ (0.1, 1, 10 μM) concentration-dependently inhibited the expression of α-SMA, and collagen I. In LX-2 cells, F₂ inhibited TGF-β/Smad signaling through reducing the levels of TGFBR2; pretreatment with LY2109761 (TGF-β signaling inhibitor) or SP600125 (c-Jun signaling inhibitor) markedly inhibited TGF-β1-induced induction of α-SMA and collagen I. Knockdown of c-Jun decreased TGF-β signaling genes, including TGFBR2 levels. We revealed that c-Jun was bound to the TGFBR2 promoter, whereas F₂ suppressed the binding of c-Jun to the TGFBR2 promoter to restrain TGF-β signaling and inhibit α-SMA and collagen I upregulation. In conclusion, the therapeutic benefit of F₂ against liver fibrosis results from inhibition of c-Jun expression to reduce TGFBR2 and concomitant reduction of the responsiveness of hepatic stellate cells to TGF-β1. F₂ may thus be a potentially new effective pharmacotherapy for human liver fibrosis.

Involvement of SIRT1 in amelioration of schistosomiasis-induced hepatic fibrosis by genistein

Previous study revealed that genistein alleviate the extent of hepatic fibrosis in schistosomiasis-infected mice, however, the potential mechanism is still incomplete. Present study was, therefore, carried out to investigate the underlying mechanism of ameliorating schistosomiasis-induced hepatic fibrosis by genistein. α-smooth muscle actin (α-SMA) expression, as a critical fibrotic marker, was markedly upregulated in Schistosoma japonicum (S. japonicum) egg-induced liver fibrosis, and gradually inhibited by genistein administration in infected mice. Contrary to the changes of α-SMA expression, hepatic SIRT1 expression and activity was greatly inhibited in mice upon S. japonicum infection, and the repression was reversed in liver tissues after receiving 25 mg/kg genistein. 50 mg/kg genistein treatment gave rise to the higher SIRT1 expression and activity than that of the control group. In hepatic stellate cells (HSCs), genistein (5, 10, 20 μM) treatment resulted in the increases of SIRT1 expression and activity in concentration-dependent manner. Moreover, to mimic the fibrogenesis in vivo, macrophage was treated with soluble egg antigen (SEA) to obtain macrophage-conditioned medium (MφCM), which was used to stimulate HSCs. Intriguingly, SIRT1 overexpression decreased fibrosis associated gene expression in HSCs exposed to MφCM or not. Additionally, MφCM gave rise to high levels of α-SMA and p-Smad3 and the increments were reversed upon genistein treatment in HSCs. Furthermore, EX527, SIRT1 specific inhibitor, abrogated the inhibitory effects of genistein on HSCs activation. Together, the results support the notion that the strong elevation of SIRT1 expression and activity may represent a potential mechanism of protection against schistosomiasis-induced hepatic fibrosis by genistein.

Molecular Changes Underlying Genistein Treatment of Wound Healing: A Review

Estrogen deprivation is one of the major factors responsible for many age-related processes including poor wound healing in postmenopausal women. However, the reported side-effects of estrogen replacement therapy (ERT) have precluded broad clinical administration. Therefore, selective estrogen receptor modulators (SERMs) have been developed to overcome the detrimental side effects of ERT on breast and/or uterine tissues. The use of natural products isolated from plants (e.g., soy) may represent a promising source of biologically active compounds (e.g., genistein) as efficient alternatives to conventional treatment. Genistein as natural SERM has the unique ability to selectively act as agonist or antagonist in a tissue-specific manner, i.e., it improves skin repair and simultaneously exerts anti-cancer and chemopreventive properties. Hence, we present here a wound healing phases-based review of the most studied naturally occurring SERM.

A Comprehensive Review of Natural Products against Liver Fibrosis: Flavonoids, Quinones, Lignans, Phenols, and Acids

Liver fibrosis resulting from continuous long-term hepatic damage represents a heavy burden worldwide. Liver fibrosis is recognized as a complicated pathogenic mechanism with extracellular matrix (ECM) accumulation and hepatic stellate cell (HSC) activation. A series of drugs demonstrate significant antifibrotic activity in vitro and in vivo. No specific agents with ideally clinical efficacy for liver fibrosis treatment have been developed. In this review, we summarized the antifibrotic effects and molecular mechanisms of 29 kinds of common natural products. The mechanism of these compounds is correlated with anti-inflammatory, antiapoptotic, and antifibrotic activities. Moreover, parenchymal hepatic cell survival, HSC deactivation, and ECM degradation by interfering with multiple targets and signaling pathways are also involved in the antifibrotic effects of these compounds. However, there remain two bottlenecks for clinical breakthroughs. The low bioavailability of natural products should be improved, and the combined application of two or more compounds should be investigated for more prominent pharmacological effects. In summary, exploration on natural products against liver fibrosis is becoming increasingly extensive. Therefore, natural products are potential resources for the development of agents to treat liver fibrosis.

Protective effect of genistein on nonalcoholic fatty liver disease (NAFLD)

NAFLD is a vital health problem worldwide; however, no effective treatment is currently available for NAFLD. Intensive studies have indicated the efficacy of genistein (GE), a bioactive isoflavone extracted from soy, in treating NAFLD. In addition to its oestrogen-like effects, GE is known to have multiple molecular effects, for instance, lipid and glucose metabolism-promoting effects and activities against lipid peroxidation, inflammation, fibrosis, and NAFLD-related tumours. Here, this review summarizes the potential role of GE in the treatment and prevention of NAFLD and some of the currently known targets and signalling pathways of GE in NAFLD.

肝纤维化逆转机制的研究进展及治疗概况

肝纤维化是肝脏对慢性损伤的一种修复反应, 多是持续性肝脏损伤或纤维化刺激因子刺激产生的共有病理改变, 是一项严重的全球性健康难题. 近年来临床研究发现, 由病毒性肝炎造成肝纤维化或肝硬化的患者, 在成功接受病毒性肝炎治疗后, 其肝纤维化甚至肝硬化发生了逆转现象. 因此研究和了解肝纤维化逆转的机制有利于发现新的针对肝纤维化的治疗靶向. 本文就近年来有关肝纤维化逆转机制的研究以及治疗概况作一综述, 以期为肝纤维化的研究提供帮助.

Inhibitory effects of Doenjang, Korean traditional fermented soybean paste, on oxidative stress and inflammation in adipose tissue of mice fed a high-fat diet

BACKGROUND/OBJECTIVES

Doenjang, Korean traditional fermented soybean paste has been reported to have an anti-obesity effect. Because adipose tissue is considered a major source of inflammatory signals, we investigated the protective effects of Doenjang and steamed soybean on oxidative stress and inflammation in adipose tissue of diet-induced obese mice.

MATERIALS/METHODS

Male C57BL/6J mice were fed a low fat diet (LF), a high-fat diet (HF), or a high-fat containing Doenjang diet (DJ) or a high-fat containing steamed soybean diet (SS) for 11 weeks.

RESULTS

Mice fed a DJ diet showed significantly lower body and adipose tissue weights than those in the HF group. Although no significant differences in adipocyte size and number were observed among the HF diet-fed groups, consumption of Doenjang alleviated the incidence of crown-like structures in adipose tissue. Consistently, we observed significantly reduced mRNA levels of oxidative stress markers (heme oxygenase-1 and p40^phox), pro-inflammatory adipokines (tumor necrosis factor alpha and macrophage chemoattractant protein-1), macrophage markers (CD68 and CD11c), and a fibrosis marker (transforming growth factor beta 1) by Doenjang consumption. Gene expression of anti-inflammatory adipokine, adiponectin was significantly induced in the DJ group and the SS group compared to the HF group. The anti-oxidative stress and anti-inflammatory effects observed in mice fed an SS diet were not as effective as those in mice fed a DJ diet, suggesting that the bioactive compounds produced during fermentation and aging may be involved in the observed health-beneficial effects of Doenjang.

CONCLUSIONS

Doenjang alleviated oxidative stress and restored the dysregulated expression of adipokine genes caused by excess adiposity. Therefore, Doenjang may ameliorate systemic inflammation and oxidative stress in obesity via inhibition of inflammatory signals of adipose tissue.

Visfatin: an adipokine activator of rat hepatic stellate cells

The present study was conducted to investigate the effects of visfatin on the activation of hepatic stellate cells (HSC) and the possible underlying mechanism. HSC were isolated from the livers of Sprague‑Dawley rats by in situ perfusion of collagenase and pronase and a single‑step density Nycodenz gradient. The culture‑activated cells were serum‑starved and incubated with different concentrations of recombinant visfatin (0, 25, 50, 100 or 200 ng/ml) for 24 h. The expression of α‑smooth muscle actin (α‑SMA), collagen types I and III and connective tissue growth factor (CTGF) were then measured by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis. The results demonstrated that 100 and 200 ng/ml concentrations of visfatin induced the expression of α‑SMA in culture‑activated rat HSC, which was accompanied by a significant increase in collagen types I and III, as confirmed by western blot and RT‑qPCR analyses. In addition, treatment of the HSC with certain concentrations of visfatin upregulated the expression of CTGF. These findings suggested that visfatin activated HSC and induced the production of collagen types I and III.

The possibility of genistein as a new direct pulp capping agent

Genistein, kind of soy isoflavones, is well-known as natural ingredients and consumed as health foods and supplements. They are expected to improve renal function. They have high-affinity to estrogen receptor β expressed predominantly in bone tissue, they prevent osteoporosis specifically and safely. We examined whether genistein can be a new direct capping agent. In this study, we examined the effect of genistein for the proliferation and differentiation of rat dental pulp cells in vitro and the ability of tertiary dentin formation in vivo. As a result, rat dental pulp cells with genistein were increased activity of ALPase and showed alizarin red positive-staining. Calcification-related genes expression has been confirmed by the addition of genistein. From in vivo study, high quality of tertiary dentin formation and minor pulp reaction were observed. From these findings, it was suggested that genistein may be useful agent for direct pulp capping.

Preliminary investigation of the effects of long-term dietary intake of genistein and daidzein on hepatic histopathology and biochemistry in domestic cats (Felis catus)

Dietary isoflavones have been hypothesised to play a role in hepatic veno-occlusive disease in captive exotic felids, although empirical evidence is lacking. This study aimed to investigate the effect of long-term (>1 year) dietary genistein and daidzein exposure on the hepatic biochemistry and histology of domestic cats. Individual cats were assessed for hepatic enzyme and bile acid production before and after the removal of isoflavones from their diet in the treatment group (n = 4), and at the same times in unexposed control animals (n = 7). No significant differences were detectable in hepatic biochemistry between treatment and control groups, and all serum values were within the normal reference ranges for domestic cats. Additionally, treatment animals demonstrated slightly greater areas of fibrosis surrounding hepatic venules than control animals, but this difference was not statistically significant. On the basis of the results presented, dietary isoflavones, at the current dose and duration of exposure do not appear to modulate hepatic enzyme production or histological parameters.

Soy isoflavone delays the progression of thioacetamide-induced liver fibrosis in rats

OBJECTIVE

Our aim was to investigate the effect of soy isoflavone (SI) on liver fibrosis in a thioacetamide (TAA)-induced rat model.

MATERIALS AND METHODS

Twenty-eight rats were assigned to four groups: sham group, fibrosis group, low-dose treatment group (LDg) and high-dose treatment group (HDg). SI (90 or 270 mg/kg) was administered daily during the model development by TAA. Standard liver tests, platelet derived growth factor-BB (PDGF-BB) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were measured. The expression of collagen, α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1) in liver tissue was determined. Electron microscopy was used to perform ultrastructural analysis of the livers.

RESULTS

Hepatic fibrosis was induced by 8 weeks of TAA administration. However, following the administration of SI, collagen staining significantly declined as compared with the fibrosis group (p < 0.01). Less collagen fibers around the hepatic stellate cells (HSCs) were observed in HDg as compared to the fibrosis group and LDg. There was no significant difference in standard liver tests between the fibrosis group and the two treatment groups. The levels of PDGF-BB and TIMP-1 in the two SI-treated groups were significantly lower than in the fibrosis group (p < 0.01). The expression of α-SMA and TGF-β1 in HDg was less than that in the fibrosis group and LDg (p < 0.01).

CONCLUSION

Administration of a high dose of SI resulted in an obvious inhibitory effect on liver fibrosis induced by TAA in rats. One hypothesis is that the effect may be related to the inhibition of HSC activation and proliferation.

Transcriptional regulation of hepatic stellate cells

Hepatic stellate cell (HSC) activation is a process of cellular transdifferentiation in which, upon liver injury, the quiescent vitamin A storing perisinusoidal HSC is converted into a wound-healing myofibroblast and acquires potent pro-inflammatory and pro-fibrogenic activities. This remarkable phenotypic transformation is underpinned by changes in the expression of a vast number of genes. In this review we survey current knowledge of the transcription factors that either control HSC activation or which regulate specific fibrogenic functions of the activated HSC such as collagen expression, proliferation and resistance to apoptosis.

RNA interference targeting the platelet-derived growth factor receptor beta subunit ameliorates experimental hepatic fibrosis in rats

BACKGROUND/AIMS

Platelet-derived growth factor (PDGF) is the strongest stimulator of the proliferation of hepatic stellate cells (HSCs). PDGF receptor beta subunit (PDGFR-beta) is acquired on HSCs proliferation induced by PDGF. In this study, we aim to investigate the effect of PDGFR-beta small interference RNA (siRNA) on experimental hepatic fibrosis.

METHODS

We constructed a PDGFR-beta siRNA expression plasmid and investigated its effect on the activation of HSCs. Bromodeoxyuridine incorporation was performed to investigate the effect of PDGFR-beta siRNA on HSCs proliferation. A hydrodynamics-based transfection method was used to deliver PDGFR-beta siRNA to rats with hepatic fibrosis. The distribution of transgenes in the liver was observed by immunofluorescence. The antifibrogenic effect of PDGFR-beta siRNA was investigated pathologically.

RESULTS

Platelet-derived growth factor receptor-beta subunit siRNA could significantly downregulate PDGFR-beta expression, suppress HSCs activation, block the mitogen-activated protein kinase signalling pathway and inhibit HSCs proliferation in vitro. PDGFR-beta siRNA expression plasmid could be delivered into activated HSCs by the hydrodynamics-based transfection method, and remarkably improve the liver function of the rat model induced by dimethylnitrosamine and bile duct ligation. Furthermore, the progression of fibrosis in the liver was significantly suppressed by PDGFR-beta siRNA in both animal models.

CONCLUSIONS

Platelet-derived growth factor receptor-beta subunit siRNA may be presented as an effective antifibrogenic gene therapeutic method for hepatic fibrosis.

Genistein and phycocyanobilin may prevent hepatic fibrosis by suppressing proliferation and activation of hepatic stellate cells

Hepatic fibrosis reflects hepatotoxin-mediated activation of hepatic stellate cells, resulting in their proliferation and transformation to myofibroblasts that secrete collagen. This activation is suppressed by estrogen, an effect which explains the decreased risk for hepatic fibrosis enjoyed by premenopausal women and by postmenopausal women receiving hormone replacement therapy. Since stellate cells have been found to express the beta but not the alpha isoform of the estrogen receptor, it can be predicted that nutritional intakes of the soy isoflavone genistein - a selective agonist for ERbeta in the low nanomolar plasma concentrations achievable with these intakes - have potential for suppressing hepatic fibrosis, in both men and women. The antiproliferative impact of estrogen on stellate cells is mediated at least in part by suppression of NADPH oxidase activity; oxidant production by this enzyme complex plays a crucial role in stellate cell activation. Alternatively, it may be feasible to inhibit NADPH oxidase with phycocyanobilin (PCB), a biliverdin homolog found in spirulina that has recently been shown to inhibit the NADPH oxidase activity of human cell cultures in low micromolar concentrations. Joint administration of soy isoflavones and PCB in appropriate doses might have considerable potential for prevention of hepatic fibrosis in at-risk subjects.

Protective role of genistein in acute liver damage induced by carbon tetrachloride

Aim. In the present study, we investigated the protective effect of genistein in experimental acute liver damage induced by CCl₄. Method. Forty rats were equally allocated to 5 groups. The first group was designated as the control group (group 1). The second group was injected with intraperitoneal CCl₄ for 3 days (group 2). The third group was injected with subcutaneous 1 mg/kg genistein for 4 days starting one day before CCl₄ injection. The fourth group was injected with intraperitoneal CCl₄ for 7 days. The fifth group was injected with subcutaneous 1 mg/kg genistein for 8 days starting one day before CCl₄ injection. Plasma and liver tissue malondialdehyde (MDA) and liver glutathione levels, as well as AST and ALT levels were studied. A histopathological examination was conducted. Results. Liver tissue MDA levels were found significantly lower in group 3, in comparison to group 2 (P < .05). Liver tissue MDA level in group 5 was significantly lower than that in group 4 (P < .001). Liver tissue glutathione levels were higher in group 5 and 3, relative to groups 4 and 2, respectively (P > .05 for each). Inflammation and focal necrosis decreased in group 3, in comparison to group 2 (P < .001 for each). Inflammation and focal necrosis in group 5 was lower than that in group 4 (P < .001). Actin expression decreased significantly in group 5, relative to group 4 (P < .05). Conclusion. Genistein has anti-inflammatory and antinecrotic effects on experimental liver damage caused by CCl₄. Genistein reduces liver damage by preventing lipid peroxidation and strengthening antioxidant systems.

Targeted inhibition of platelet-derived growth factor receptor-beta subunit in hepatic stellate cells ameliorates hepatic fibrosis in rats

The activation of hepatic stellate cells (HSCs) is the key event of the pathogenesis of hepatic fibrosis. Platelet-derived growth factor (PDGF) is the most potent mitogen for HSCs, and PDGF receptor-beta subunit (PDGFR-beta) is required for the proliferation of HSCs induced by PDGF. In this study, a high gene-silencing-efficacy PDGFR-beta small interference RNA (siRNA) was synthesized that could suppress the PDGFR-beta expression and inhibit the activation and proliferation but could not induce the apoptosis of HSCs in vitro. To avoid the side effect of nonspecific interference of PDGFR-beta, we constructed an HSCs-specific short hairpin RNA (shRNA) expression plasmid in which PDGFR-beta shRNA was driven by a glial fibrillary acidic protein (GFAP) promoter. The double-staining immunofluorescence examination indicated that GFAP promoter could target the transgene expression into HSCs in carbon tetrachloride induced acute injured rat's liver and bile duct ligation (BDL)-induced chronic injured rat's liver. Furthermore, HSCs-specific PDGFR-beta shRNA could relieve liver injury and hepatic fibrosis in the rat's model induced by BDL. This study demonstrates that PDGFR-beta siRNA may be presented as an antifibrogenic agent. The application of HSCs-specific RNA interference induced by the GFAP promoter might supply a new powerful tool for cell-specific gene therapy of hepatic fibrogenesis.

Gene expression profiles during the activation of rat hepatic stellate cells evaluated by cDNA microarray

Hepatic stellate cells (HSCs) are activated by producing potentially injurious connective tissue components during hepatic fibrosis, thereby exerting a pivotal action in the development of liver fibrogenesis. The aim of this study was to investigate differences in gene expression patterns during the activation of HSCs using complementary cDNA microarrays. HSCs were isolated from normal rat livers and cultured for 0 (3 h), 3, 5 and 7 d. RNA was extracted from cultured cells at each point. The target RNA was hybridized to gene-specific sequence probes immobilized on chips. The hybridization signal was assessed using a confocal laser scanner. Comparison of hybridization signals and patterns allows the identification of mRNAs that are expressed differentially. Statistical analysis was used to classify and cluster the genes according to their up- or downregulation. As a result, 33 upregulated early-stage and 36 upregulated late-stage gene candidates were identified. This time-based study revealed a number of newly discovered genes involved in fibrogenesis during the activation of HSCs.

The treatment with antibody of TNF-alpha reduces the inflammation, necrosis and fibrosis in the non-alcoholic steatohepatitis induced by methionine- and choline-deficient diet

To assess the effects of anti-TNF-alpha antibody (infliximab) in experimental steatohepatitis induced by methionine- and choline-deficient (MCD) diet. The study included thirty rats. One group received normal rat food, and two groups received MCD diet. The treatment group received a single dose intra-peritoneal infliximab (4 mg/kg), at week 8. MCD diet increased levels of AST, ALT, TNF-alpha, TGF-beta(1), tissue and plasma MDA (p < 0.05 for each). Moreover, it led to steatosis, ballooning degeneration, inflammation, fibrosis and increased actin expression, histopathologically (p < 0.05 for each). In this experimental steatohepatitis anti-TNF-alpha antibody decreased the levels of AST, ALT, TGF-beta(1) and plasma and tissue MDA (p < 0.05 for each). Moreover, inflammation, necrosis, actin expression and fibrosis decreased in anti-TNF-alpha group compared to placebo group (p < 0.05 for each). This study indicates that anti-TNF-alpha antibody is effective on necrosis, inflammation and fibrosis in the experimental model of non-alcoholic steatohepatitis, induced by MCD diet.

Preventive role of genistein in an experimental non-alcoholic steatohepatitis model

BACKGROUND AND AIM

The aim of the present study was to evaluate the preventive role of genistein, a phytoestrogen with a wide variety of pharmacological effects, in an experimental non-alcoholic steatohepatitis (NASH) model.

METHODS

Thirty-six Sprague-Dawley rats were divided into three groups. Group 1 (control) received only a standard rat diet, group 2 (placebo) was given a high fat diet (HFD) plus 0.5 mL/day saline subcutaneously, and group 3 (genistein group) a HFD plus subcutaneous genistein injection at dose of 0.2 mg/kg/day for 6 weeks. All rats were killed after 6 weeks. Serum aminotransferases, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta, and plasma and liver malondialdehyde (MDA) levels were measured. Additionally, steatosis, ballooning degeneration and inflammation of the liver were examined histopathologically.

RESULTS

Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) (P < 0.001 for each), plasma and liver tissue MDA and plasma TNF-alpha levels (P < 0.001, <0.001, <0.01, respectively) were found to be higher in the placebo group than in the control group. TGF-beta levels, however, were comparable in the placebo and control groups (P > 0.05). Histopathologically, steatosis, inflammatory cells per mm(2) and ballooning degeneration were significantly higher in the placebo group than in the control group (P < 0.001 for each). Nevertheless, AST and ALT (P < 0.05 for each), plasma and liver tissue MDA (P < 0.05 for each) and plasma TNF-alpha levels (P < 0.001) were significantly decreased in the genistein group compared to the placebo group. Histopathologically, steatosis (P < 0.05), inflammatory cells per mm(2) and ballooning degeneration (P < 0.01 for each) in the genistein group were also significantly lower than in the placebo group.

CONCLUSIONS

Genistein, a strong antioxidant agent, significantly decreased the plasma TNF-alpha level and remarkably prevented the emergence of NASH by improving the biochemical and histopathological abnormalities via attenuating oxidative stress.

Genistein modifies liver fibrosis and improves liver function by inducing uPA expression and proteolytic activity in CCl4-treated rats

AIM

To evaluate the effect of genistein on the fibrosis and matrix degradation caused by experimentally induced fibrosis in rats.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Matrix metalloproteinase gene delivery for liver fibrosis

The resolution of advanced liver fibrosis has been recently recognized to be possible, if the causative stimuli are successfully removed. However, whether complete resolution from cirrhosis, the end stage of liver fibrosis, can be achieved is still questionable. Delivery of interstitial collagenases, such as matrix metalloproteinase (MMP)-1, in the liver could be an attractive strategy to treat advanced hepatic fibrosis from the view point that the imbalance between too few interstitial collagenases and too many of their inhibitors is the main obstacle to the resolution from fibrosis. Remodeling of hepatic extracellular matrix by delivered interstitial collagenases also facilitates the disappearance of activated hepatic stellate cells, the main matrix-producing cells in the liver, and promotes the proliferation of hepatocytes. This review will focus on the impact of the gene delivery of MMPs for the treatment of advanced liver fibrosis while discussing other current therapeutic strategies for liver fibrosis, and on the need for the development of a safe and effective delivery system of MMPs.

Polyphenols and cancer cell growth

Polyphenols constitute an important group of phytochemicals that gained increased research attention since it was found that they could affect cancer cell growth. Initial evidence came from epidemiologic studies suggesting that a diet that includes regular consumption of fruits and vegetables (rich in polyphenols) significantly reduces the risk of many cancers. In the present work we briefly review the effects of polyphenols on cancer cell fate, leading towards growth, differentiation and apoptosis. Their action can be attributed not only to their ability to act as antioxidants but also to their ability to interact with basic cellular mechanisms. Such interactions include interference with membrane and intracellular receptors, modulation of signaling cascades, interaction with the basic enzymes involved in tumor promotion and metastasis, interaction with oncogenes and oncoproteins, and, finally, direct or indirect interactions with nucleic acids and nucleoproteins. These actions involve almost the whole spectrum of basic cellular machinery--from the cell membrane to signaling cytoplasmic molecules and to the major nuclear components--and provide insights into their beneficial health effects. In addition, the actions justify the scientific interest in this class of compounds, and provide clues about their possible pharmaceutical exploitation in the field of oncology.

Tumor necrosis factor-alpha-induced production of plasminogen activator inhibitor 1 and its regulation by pioglitazone and cerivastatin in a nonmalignant human hepatocyte cell line

Plasminogen activator inhibitor 1 (PAI-1) is an important mediator of atherosclerosis and liver fibrosis in insulin resistance. Circulating levels of PAI-1 are elevated in obese individuals, and PAI-1 messenger RNA is significantly higher in the livers of obese type 2 diabetic individuals than in nonobese type 2 diabetic individuals. To address the mechanism underlying the up-regulation of hepatic PAI-1 in obesity, we tested the effects of tumor necrosis factor alpha (TNF-alpha), an important link between obesity and insulin resistance, on PAI-1 production in the nonmalignant human hepatocyte cell line, THLE-5b. Incubation of THLE-5b cells with TNF-alpha stimulated PAI-1 production via protein kinase C-, mitogen-activated protein kinase-, protein tyrosine kinase-, and nuclear factor-kappaB-dependent pathways. A thiazolidinedione, pioglitazone, reduced TNF-alpha-induced PAI-1 production by 32%, via protein kinase C- and nuclear factor-kappaB-dependent pathways. The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor cerivastatin inhibited TNF-alpha-induced PAI-1 production by 59%, which was reversed by coincubation with mevalonic acid. In conclusion, obesity and TNF-alpha up-regulation of PAI-1 expression in human hepatocytes may contribute to the impairment of the fibrinolytic system, leading to the development of atherosclerosis and liver fibrosis in insulin-resistant individuals. A thiazolidinedione and a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor may thus be candidate drugs to inhibit obesity-associated hepatic PAI-1 production.

[6]-Gingerol induces cell cycle arrest and cell death of mutant p53-expressing pancreatic cancer cells

[6]-Gingerol, a major phenolic compound derived from ginger, has anti-bacterial, anti-inflammatory and anti-tumor activities. While several molecular mechanisms have been described to underlie its effects on cells in vitro and in vivo, the underlying mechanisms by which [6]-gingerol exerts anti-tumorigenic effects are largely unknown. The purpose of this study was to investigate the action of [6]-gingerol on two human pancreatic cancer cell lines, HPAC expressing wild- type (wt) p53 and BxPC-3 expressing mutated p53. We found that [6]-gingerol inhibited the cell growth through cell cycle arrest at G1 phase in both cell lines. Western blot analyses indicated that [6]-gingerol decreased both Cyclin A and Cyclin-dependent kinase (Cdk) expression. These events led to reduction in Rb phosphorylation followed by blocking of S phase entry. p53 expression was decreased by [6]-gingerol treatment in both cell lines suggesting that the induction of Cyclin-dependent kinase inhibitor, p21cip1, was p53-independent. [6]-Gingerol induced mostly apoptotic death in the mutant p53-expressing cells, while no signs of early apoptosis were detected in wild type p53-expressing cells and this was related to the increased phosphorylation of AKT. These results suggest that [6]-gingerol can circumvent the resistance of mutant p53- expressing cells towards chemotherapy by inducing apoptotic cell death while it exerts cytostatic effect on wild type p53- expressing cells by inducing temporal growth arrest.

Genistein inhibits invasive potential of human hepatocellular carcinoma by altering cell cycle, apoptosis, and angiogenesis

AIM: To study the in vitro and in vivo inhibitory effects of genistein on invasive potential of Bel 7402 hepatocellular carcinoma (HCC) cells and to explore the underlying mechanism.

METHODS: Bel 7402 HCC cells were exposed to genistein. The invasive activity of tumor cells was assayed in transwell cell culture chamber. p125^FAK expression and cell cycle were evaluated by a functional assay. Cell apoptosis analysis was performed with TUNEL method. In addition, bilateral subrenal capsule xenograft transplantation of HCC was performed in 10 nude mice. Genistein was injected and the invasion of HCC into the renal parenchyma was observed. Microvessels with immunohistochemical staining were detected.

RESULTS: Genistein significantly inhibited the growth of Bel 7402 cells, the inhibitory rate of tumor cells was 26–42%. The invasive potential of Bel 7402 cells in vitro was significantly inhibited, the inhibitory rate was 11–28%. Genistein caused G2/M cell cycle arrest, S phase decreased significantly. The occurrence of apoptosis in genistein group increased significantly. The expression of p125^FAK in 5 μg/mL genistein group (15.26±0.16%) and 10 μg/mL genistein group (12.89±0.36%) was significantly lower than that in the control group (19.75±1.12%, P<0.05). Tumor growth in genistein-treated nude mice was significantly retarded in comparison to control mice, the inhibitory rate of tumor growth was about 20%. Genistein also significantly inhibited the invasion of Bel 7402 cells into the renal parenchyma of nude mice with xenograft transplant. The positive unit value of microvessels in genistein-treated group (10.422 ± 0.807) was significantly lower than that in control group (22.330 ± 5.696, P < 0.01).

CONCLUSION: Genistein can effectively inhibit the invasive potential of Bel 7402 HCC cells by altering cell cycle, apoptosis and angiogenesis, inhibition of focal adhesion kinase may play a significant role in this process.

Mechanisms of liver fibrosis

Liver fibrosis represents a significant health problem worldwide of which no acceptable therapy exists. The most characteristic feature of liver fibrosis is excess deposition of type I collagen. A great deal of research has been performed to understand the molecular mechanisms responsible for the development of liver fibrosis. The activated hepatic stellate cell (HSC) is the primary cell type responsible for the excess production of collagen. Following a fibrogenic stimulus, HSCs change from a quiescent to an activated, collagen-producing cell. Numerous changes in gene expression are associated with HSC activation including the induction of several intracellular signaling cascades, which help maintain the activated phenotype and control the fibrogenic and proliferative state of the cell. Detailed analyses in understanding the molecular basis of collagen gene regulation have revealed a complex process offering the opportunity for multiple potential therapeutic strategies. However, further research is still needed to gain a better understanding of HSC activation and how this cell maintains its fibrogenic nature. In this review we describe many of the molecular events that occur following HSC activation and collagen gene regulation that contribute to the fibrogenic nature of these cells and provide a review of therapeutic strategies to treat this disease.

Effects of Leflunomide on Hyaluronan Synthases (HAS): NF-κB-Independent Suppression of IL-1-Induced HAS1 Transcription by Leflunomide

Despite evidence that points to unfettered hyaluronic acid (HA) production as a culprit in the progression of rheumatic disorders, little is known about differences in regulation and biological functions of the three hyaluronan synthase (HAS) genes. Testing the effects of drugs with proven anti-inflammatory effects could help to clarify biological functions of these genes. In this study, we demonstrate that leflunomide suppresses HA release in fibroblast-like synoviocytes (FLS) in a dose-dependent manner. We further demonstrate that leflunomide suppresses HA synthase activity, as determined by (14)C-glucuronic acid incorporation assays. Additional experiments revealed that in FLS, leflunomide specifically blocked the induction of HAS1. HAS2 and HAS3, genes that are, in contrast to HAS1, constitutively expressed in FLS, are not significantly affected. Leflunomide can function as a NF-kappaB inhibitor. However, EMSA experiments demonstrate that at the concentrations used, leflunomide neither interferes with IL-1beta- nor with PMA-induced NF-kappaB translocation. Furthermore, reconstituting the pyrimidine synthase pathway did not lead to the restoration of IL-1beta-induced HAS1 activation. More importantly, two tyrosine kinase inhibitors mimicked the effect of leflunomide in that both blocked IL-1beta-induced HAS1 activation without affecting HAS2 or HAS3. These data point at HAS1 activation as the possible cause for unfettered HA production in rheumatoid arthritis and might explain, at least in part, the beneficial effects of leflunomide treatment. These findings also support the concept that IL-1beta-induced HAS1 activation depends on the activation of tyrosine kinases, and indicate that leflunomide blocks HA release by suppressing tyrosine kinases rather than through inhibition of NF-kappaB translocation.

Effect of Chinese drug compound Ganzhifu on liver fibrosis in rats

AIM: To investigate the effect of compound Ganzhifu on experimental hepatic fibrosis and its possible mechanism.

METHODS: Forty-five Wistar rats were randomly divided into four groups: normal (N) group, Ganzhifu (G) group, colchicine (C) group and model (M) group. All the rats, except those in N group, were given CCl₄ by subcutaneous injection and alcohol (10%) by oral administration to establish the model of hepatic fibrosis. At the same time, the rats in G, C or M group were treated through stomach irrigation with Ganzhifu, colchicine or saline, respectively. Blood was collected for the examination of liver function and serum fibrosis markers. Hydroxyproline (Hyp), malondial dehyde (MDA) content, and superoxide disumutase (SOD) activity were determined in liver tissues. HE, Masson and Gorden-Sweet staining were used to examine the pathological changes in liver tissue sections. Inflammation and fibrosis were evaluated by semi-quantitative scoring system (SSS). In addition, The expression of typeI, III, IV collagens was detected by immunohistochemistry.

RESULTS: Compared with that in M group, liver function was improved remarkably in G group, and there were significant decreases in the liver fibrosis markers (Hyp: 1.52±0.35 mg/g vs 1.12±0.29 mg/g, P<0.05; MDA: 16.3±6.0 mmol/g vs

8.8±2.1 mmol/g, P<0.01). However, the SOD activity was notably elevated (86.33±17.74 nkat/g vs 122.01±19.12 nkat/g, P<0.01). Less inflammation, lower degree of fibrosis and reduced content of typeI, III, IV collagens were observed in G group than in M group. No significant difference was found between the effects of Ganzhifu and colchicines against fibrosis.

CONCLUSION: Ganzhifu can protect liver from fibrosis and the mechanism may be related to its anti-oxidative effect.

Chinese herbs Kangxian ruangan keli inhibits expression of MEK-1 and c-fos in hepatic stellate cell indused by PDGF

AIM: To investigate the effect of Kangxian ruangan keli (KXR) on the expression of MEK-1 and c-fos in hepatic stellate cell (HSC) indused by PDGF.

METHODS: In a serum-free culture system, HSC was treated with a KXR preparation for 24 hours, followed by stimulation with PDGF-BB for 24 hours. Then the cells were incubated again in the medium containing KXR for 3 hours stimulated with PDGF-BB for 5 minutes, and collected. The proliferation of HSC was examined using an MTT assay. MEK-1 was detected with Western blotting and visualized by the enhenced chemiluminescent (ECL) method. The expression of c-fos mRNA was analyzed with in situ hybridization.

RESULTS: The A values for the HSC growing in the media without and with addition of PDGF were 0.170±0.060 and 0.820±0.050, respectively. The PDGF-induced increase was hindered remarkably by KXR preparation in a dose-dependent manner. Reaction values for the systems with 5 g/L and 1.25 g/L of KXR were 0.280±0.030 and 0.430±0.040 respectively, lower significantly than that in the culture free of KXR (0.820±0.050, P < 0.01). In addition, values for MEK-1 in HSC treated with 5 mg/mL and 1.25 mg/mL of KXR were 0.143±0.013, and 0.170±0.007, respectively, being lower than that in the cells treated only with PDGF-BB (0.186±0.010, P < 0.01). The expression level of c-fos mRNA was 0.152±0.010 and 0.163±0.005, respectively, also lower than that of the PDGF group (0.183±0.014, P < 0.01).

CONCLUSION: Within the dose range used in the present study, KXR preparation shows an inhibitory effect on HSC proliferation induced by PDGF. The mechanism of this process may involve interference with Ras-MEK-MAPK singal transduction mediated by PDGF.

Kangxian ruangan keli inhibits hepatic stellate cell proliferation mediated by PDGF

AIM: To investigate the effect of Kangxian ruangan keli (KXR) on hepatic stellate cell (HSC) proliferation mediated by platelet-derived growth factor (PDGF) and the underlying mechanism.

METHODS: In a serum-free culture system, HSCs were treated with a KXR preparation for 24 h, followed by stimulation with PDGF-BB for 24 h. Then the cells were incubated again in the medium containing KXR for 3 h stimulated with PDGF-BB for 5 minutes, and collected. The proliferation of HSC was examined using an MTT assay and flow cytometry. Tyrosine phosphorylation was detected with Western blotting and visualized by the enhenced chemiluminescent (ECL) method.

RESULTS: The OD values for the HSCs growing in the media without and with addition of PDGF were 0.17 ± 0.06 and 0.82 ± 0.05, respectively. The PDGF-induced increase was hindered remarkably by KXR preparation in a dose-dependent manner. The reaction values for the systems with 5 mg/mL, 2.5 mg/mL and 1.25 mg/mL of KXR were 0.28 ± 0.03, 0.37 ± 0.02 and 0.43 ± 0.04, respectively. Moreover, the percentages of S-phase cells in these KXR-containing culture systems were 10.95 ± 1.35, 32.76 ± 1.07 and 43.19 ± 1.09, respectively, all of which were significantly lower than that in the culture free of KXR (68.24 ± 2.72). In addition, the values for tyrosine-phosphorylated protein in HSCs treated with 5 mg/mL and 1.25 mg/mL of KXR were 0.1349 ± 0.0072 and 0.1658 ± 0.0025, respectively, which were smaller than that in the cells treated only with PDGF-BB (0.1813 ± 0.0117).

CONCLUSION: Within the dose range used in the present study, KXR preparation shows an inhibitory effect on HSC proliferation induced by PDGF. The mechanism of this process may involve interference with tyrosine phosphorylation mediated by PDGF.

Protective effects of Rhodiola sachalinesis A Bor on CCl4-induced liver fibrosis in rats

AIM

To study the protective effects of Rhodiola schalinensis A Bor on CCl4-induced liver fibrosis.

METHODS: Male SD rats were divided into 3 groups: normal(N), Rhodiola sachalinesis A Bor(R) and model(M) group. The M and R group were given 300 ml/L CCl₄(3ml/kg, 2 times/week) for 15 weeks and Rhodiola sachalinesis A Bor (0.5g/kg, p.o., daily for 15 weeks) was administered to rats of R group. Histopathological changes were examined. The changes of hepatic content of hydroxyproline and expression of α1(Ⅰ)mRNA were observed.

RESULTS

Rhodiola sachalinesis A Bor decreased the hepatic content of hydroxyproline (657±74 μg/g vs 1 257±98 μg/g, P<0.05) and severity of hepatic fibrosis, improved the liver histopathological changes and inhibited the expression of α1(Ⅰ) mRNA and decreased the level of HA, CⅣ, PCⅢ and TGFβ1 (164±46 μg/L, 97±15 μg/L, 289±76 μg/L, 60±20 mg/L vs 265±98 μg/L, 160±30 μg/L, 456±113 μg/L, 89±23 mg/L. P<0.05, P<0.01).

CONCLUSION

Rhodiola sachalinesis A Bor is effective in protecting against CCl4-induced liver fibrosis in rats, its machenisms appear to be associated with the inhibition of collagen production and protection of hepatic cells.

Expression of local renin and angiotensinogen mRNA in cirrhotic portal hypertensive patient

AIM

To investigate the expression of local renin and angiotensinogen mRNA in cirrhotic portal hypertensive patients.

METHODS

The expression of local renin and angiotensinogen mRNA in the liver, splenic artery and vein of PH patients was detected by RT-PCR analysis.

RESULTS

Expression of local renin mRNA in the liver of control group was (0.19+/-0.11), significantly lower than that in splenic artery (0.45+/-0.17) or splenic vein(0.39+/-0.12) respectively, (P<0.05). Expression of local angiotensinogen mRNA in the liver was (0.64+/-0.21), significantly higher than that in splenic artery(0.41+/-0.15) or in splenic vein (0.35+/-0.18) respectively, (P<0.05). Expression of local renin mRNA in the liver, splenic artery and vein of PH group was (0.78+/-0.28), (0.86+/-0.35) and (0.81+/-0.22) respectively, significantly higher than that in the control group, (P<0.05). Expression of local angiotensinogen mRNA in the liver, splenic artery and vein of PH group was (0.96+/-0.25), (0.83+/-0.18) and (0.79+/-0.23) respectively, significantly higher than that in the control group, (P<0.05). There was no significant difference between the liver, splenic artery and vein in the expression of local renin or local angiotensinogen mRNA in PH group, (P<0.05).

CONCLUSION

In normal subjects the expression of local renin and angiotensinogen mRNA was organ specific, but with increase of the expression of LRAS, the organ-specificity became lost in cirrhotic patients. LRAS may contribute to increased resistance of portal vein with liver and formation of splanchnic vasculopathy.

Rapid mitogen-activated protein kinase by basic fibroblast growth factor in rat intestine after ischemia/reperfusion injury

AIM: Previous studies showed that exogenous basic fibroblast growth factor (bFGF or FGF-2) could improve physiological dysfunction after intestinal ischemia/reperfusion (I/R) injury. However, the mechanisms of this protective effect of bFGF are still unclear. The present study was to detect the effect of bFGF on the activities of mitogen-activated protein kinase (MAPK) signaling pathway in rat intestine after I/R injury, and to investigate the protective mechanisms of bFGF on intestinal ischemia injury.

METHODS: Rat intestinal I/R injury was produced by clamping the superior mesenteric artery (SMA) for 45 min and followed by reperfusion for 48 h. Seventy-eight Wistar rats were used and divided randomly into sham-operated group (A), normal saline control group (B), bFGF antibody pre-treated group (C), and bFGF treated group (D). In group A, SMA was separated without occlusion. In groups B, C and D, SMA was separated and occluded for 45 min, then, released for reperfusion for 48 h. After the animals were sacrificed, blood and tissue samples were taken from the intestine 45 min after ischemia in group A and 2, 6, 24, and 48 h after reperfusion in the other groups. Phosphorylated forms of p42/p44 MAPK, p38 MAPK and stress activated protein kinase/C-Jun N-terminal kinase (SAPK/JNK) were measured by immunohistochemistry. Plasma levels of D-lactate were examined and histological changes were observed under the light microscope.

RESULTS: Intestinal I/R injury induced the expression of p42/p44 MAPK, p38 MAPK, and SAPK/JNK pathways and exogenous bFGF stimulated the early activation of p42/p44 MAPK and p38 MAPK pathways. The expression of phosphorylated forms of p42/p44 MAPK was primarily localized in the nuclei of crypt cells and in the cytoplasm and nuclei of villus cells. The positive expression of p38 MAPK was localized mainly in the nuclei of crypt cells, very few in villus cells. The activities of p42/p44 MAPK and p38 MAPK peaked 6 h after reperfusion in groups B and C, while SAPK/JNK peaked 24 h after reperfusion. The activities of p42/p44 MAPK and p38 MAPK peaked 2 h after reperfusion in group D and those of SAPK/JNK were not changed in group B. D-lactate levels and HE staining showed that the intestinal barrier was damaged severely 6 h after reperfusion; however, histological structures were much improved 48 h after reperfusion in group D than in the other groups.

CONCLUSION: The results indicate that intestinal I/R injury stimulates the activities of MAPK pathways, and that p42/p44 MAPK and p38MAPK activities are necessary for the protective effect of exogenous bFGF on intestinal I/R injury. The protective effect of bFGF on intestinal dysfunction may be mediated by the early activation of p42/p44 MAPK and p38 MAPK signaling pathways.

Effect of Activin on extracelluar matrix secretion in isolated rat hepatic stellate cell

AIM

To investigate the effect of activin A on the extracelluar matrix secretion of rat hepatic stellate cell.

METHODS

Hepatic stellate cells were isolated and purified from normal male Sprague-Dawley rat liver by a combination of pronase-collagenase perfusion and density gradient centrifugation. Passaged hepatic stellate cells were divided randomly into eight groups: control group(A group), ACTA 1 μg/L group (B group), ACTA 10 μg/L group(C group), ACTA 100 μg/L group (D group), TGF β₁ 10 μg/L group(E group), TGF β₁ 10 μg/L plus ACTA 1 μg/L group(F group), TGF β₁ 10 μg/L plus ACTA 10 μg/L group(G group), TGF β₁ 10 μg/L plus ACTA 100 μg/L group(H group). 24 h after incubation secretion of procollagen Ⅲ, collagen Ⅳ and mRNA of collagen Ⅲ in hepatic stellate cells were detected by radioimmunoassays and semi-quantitative RT-PCR method respectively.

RESULTS

Extracellular matrix secretion in passaged hepatic stellate cells was enhanced by activin A according to its concentration, the capacity of extracellular matrix secretion by 100 μg/L activin A was equal to that of 10 μg/L TGF β₁, extracellular matrix secretion and type Ⅲ collagen mRNA expression in passaged hepatic stellate cells was enhanced by activin A and TGFβ₁ in a synergistic manner.

CONCLUSION

Activin A may contribute to hepatic fibrogenesis.

Effect of caffeic acid phenethyl ester on proliferation and apoptosis of hepatic stellate cells in vitro

AIM

To investigate the role of nuclear factor-kappaB (NF-kappaB) inhibitor caffeic acid phenethy1 ester (CAPE) in the proliferation, collagen synthesis and apoptosis of hepatic stellate cells (HSCs) of rats.

METHODS

The HSCs from rats were isolated and cultured in Dulbecco's Modified Eagle's Medium (DMEM) and treated with CAPE. The proliferation and collagen synthesis of HSCs were determined by (3)H-TdR and (3)H-proline incorporation respectively, and the expression of type I, III procollagen genes was further explored by in situ hybridization. Apoptosis cell indices (AIs) were examined using terminal deoxynucleotidyl transferase- mediated DIG-dUTP nick end labeling (TUNEL).

RESULTS

In activated HSC in culture, CAPE significantly inhibited (3)H-TdR and (3)H-proline incorporation by HSCs at concentrations of 5 micromol/L and 10 micromol/L respectively. CAPE also reduced the type I procollagen gene expression (P<0.05) at higher concentration. Apoptosis of HSC was induced by CAPE and the AIs were time-and dose-dependently increased from 2.82+/-0.73 % to 7.66+/-1.25 % at 12 h (P<0.01) and from 3.15+/-0.88 % to 10.61+/-2.88 % at 24 h (P<0.01).

CONCLUSION

CAPE inhibits proliferation and collagen synthesis of HSC at lower concentration and induces HSC apoptosis at higher concentration.

Fos expression in tyrosine hydroxylase-containing neurons in rat brainstem after visceral noxious stimulation: an immunohistochemical study

AIM: To prove that neurons in the different structures of the brainstem that express tyrosine hydroxylase (TH) are involved in the transmission and modulation of visceral or somatic nociceptive information in rat.

METHODS: Immunohistochemical double-staining method was used to co-localize TH and Fos expression in neurons of the rat brainstem in visceral or subcutaneous noxious stimulation models.

RESULTS: Neurons co-expressing TH/Fos were observed in lateral reticular nucleus (LRT), rostroventrolateral reticular nucleus (RVL), solitary tract nucleus (SOL), locus coeruleus (LC), A5, A7 neuronal groups and ventrolateral subdivision of the periaqueductal gray (vlPAG) in both models. But the proportion and number of the double-labeled neurons responding to the two noxious stimuli were significantly different in the LRT, RVL and LC nuclei. The proportion and number of the TH/Fos double-labeled neurons in the visceral pain model were smaller than that in the subcutaneous pain model. However, in the case of SOL, they were similar in the two models.

CONCLUSION: Differences of Fos expression in TH immunoreactive neurons in animals after visceral and somatic noxious stimulation indicate that the mechanisms of the transmission and modulation of visceral nociceptive information in the brainstem may be different from that of somatic nociceptive information.