Effects of c-myb antisense RNA on TGF-β1 and α1-Ⅰ collagen expression in cultured hepatic stellate cells

AIM: To investigate the effects of c-myb antisense RNA on cell proliferation and the expression of c-myb, TGF-β1 and α1-Ⅰ collagen in cultured hepatic stellate cells (HSC) from rats.METHODS: Recombinant retroviral vector of c-myb antisense gene (pDOR-myb) was constructed, and then transfected into retroviral package cell line PA317 by means of DOTAP.The pseudoviruses produced from the resistant PA317 cells were selected with G418 to infect HSCs isolated from rat livers. The cell proliferation was measured by 3-[4,5-Dimethylthiazolzyl]-2, 5-diphenyl tetrazo-dium bromide (MTT) method.The expression of c-myb, α1-Ⅰ collagen and TGF-β1 rnRNA, and c-myb protein in HSCs was detected with semi-quantitive reverse transeription-polymerase chain reaction (RT-PCR) and Western-blot respectively.RESULTS: HSCs from rats were isolated successfully with the viability >98%. In the pDOR-myb infected HSCs, the cmyb protein expression, cell proliferation,and α1-Ⅰ collagen and TGF-β1 mRNA expression were repressed significantly compared with their corresponding control groups (P<0.01).CONCLUSION: c-myb plays a key role in activation and proliferation of HSC. c-myb antisense RNA can inhibit cell proliferation, α1-Ⅰ collagen and TGF-β1 mRNA expression,suggesting that inhibition of c-myb gene expression might be a potential way for the treatment of liver fibrosis.     

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

AIM: To investigate the role of nuclear factor-κB (NF-κB)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 3H-TdR and 3H-proline incorporation respectively, and the expression of type Ⅰ, Ⅲ procollagen genes was further explored byin situ hybridization. Apoptosis cell indices (AIs) were examined using terminal deoxynucleotidyl transferase- mediated DIG-dUTP nick end labeling (TUNEL). RESULTS: Tn activated HSC in culture, CAPE significantly inhibited 3H-TdR and 3H-proline incorporation by HSCs at concentrations of 5 μmol/L and 10 μmol/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 10.6L±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.     

Involvement of 90-kuD ribosomal S6 kinase in collagen type Ⅰ expression in rat hepatic fibrosis

AIM: To investigate the relationship between 90-kuD ribosomal S6 kinase (p90RSK) and collagen type Ⅰ expression during the development of hepatic fibrosis in vivo and in vitro. METHODS: Rat hepatic fibrosis was induced by intraperitoneal injection of dimethylnitrosamine. The protein expression and cell location of p90RSK and their relationship with collagen type Ⅰ were determined by co-immunofluoresence and confocal microscopy. Subsequently, RNAi strategy was employed to silence p90RSK mRNA expression in HSC-T6, an activated hepatic stellate cell (HSC) line. The expression of collagen type Ⅰ in HSC-T6 cells was assessed by Western blotting and real-time polymerase chain reaction. Furthermore, HSCs were transfected with expression vectors or RNAi constructs of p90RSK to increase or decrease the p90RSK expression, then collagen type Ⅰ promoter activity in the transfected HSCs was examined by reporter assay. Lastly HSC-T6 cells transfected with p90RSK siRNA was treated with or without platelet-derived growth factor (PDGF)-BB at a final concentration of 20 μg/L and the cell growth was determined by MTS conversion. RESULTS: In fibrotic liver tissues, p90RSK was overexpressed in activated HSCs and had a significant positive correlation with collagen type Ⅰ levels. In HSC-T6 cells transfected with RNAi targeted to p90RSK, the expression of collagen type Ⅰ was downregulated (61.8% in mRNA, P < 0.01, 89.1% in protein, P < 0.01). However, collagen type Ⅰ promoter activity was not increased with over-expression of p90RSK and not decreased with low expression either, compared with controls in the same cell line ( P = 0.076). Furthermore, p90RSK siRNA exerted the inhibition of HSC proliferation, and also abolished the effect of PDGF on the HSC proliferation. CONCLUSION: p90RSK is over-expressed in activated HSCs and involved in regulating the abnormal expression of collagen type Ⅰ through initiating the proliferation of HSCs.     

Involvement of 90-kuD ribosomal S6 kinase in collagen type I expression in rat hepatic fibrosis

AIM： To investigate the relationship between 90-kuD ribosomal $6 kinase （pg0RSK） and collagen type I expression during the development of hepatic fibrosis in vivo and in vitro.METHODS： Rat hepatic fibrosis was induced by intraperitoneal injection of dimethylnitrosamine. The protein expression and cell location of p90RSK and their relationship with collagen type I were determined by co-immunofluoresence and confocal microscopy.Subsequently, RNAi strategy was employed to silence p90RSK mRNA expression in HSC-T6, an activated hepatic stellate cell （HSC） line. The expression of collagen type I in HSC-T6 cells was assessed by Western blotting and real-time polymerase chainreaction. Furthermore, HSCs were transfected with expression vectors or RNAi constructs of p90RSK to increase or decrease the p90RSK expression, thencollagen type I promoter activity in the transfected HSCs was examined by reporter assay. Lastly HSC-T6 cells transfected with p90RSK siRNA was treated withor without platelet-derived growth factor （PDGF）-BB at a final concentration of 20μg/L and the cell growthwas determined by MTS conversion.RESULTS： In fibrotic liver tissues, p90RSK was over-expressed in activated HSCs and had a significantpositive correlation with collagen type I levels.In HSC-T6 cells transfected with RNAi targeted top90RSK, the expression of collagen type I was down-regulated （61.8% in mRNA, P 〈 0.01, 89.1% inprotein, P 〈 0.01）. However, collagen type ] promoteractivity was not increased with over-expression of p90RSK and not decreased with low expression either,compared with controls in the same cell line （P = 0.076）.Furthermore, p90RSK siRNA exerted the inhibitionof HSC proliferation, and also abolished the effect of PDGF on the HSC proliferation.CONCLUSION： p90RSK is over-expressed in activatedHSCs and involved in regulating the abnormalexpression of collagen type I through initiating theproliferation of HSCs.     

Effect of IL-10 on the expression of HSC growth factors in hepatic fibrosis rat

AIM: To study the effect of IL-10 on the expression of growth factors - transforming growth factor-β1(TGF-β1), epidermal growth factor (EGF), hepatocyte growth factor (HGF)and platelet-derived growth factor (PDGF) of hepatic stellate cells (HSCs) of hepatic fibrosis rat and the anti-fibrogenic role of exogenous IL-10. METHODS: Hepatic fibrosis was induced by CCl4 administration intra-peritoneally. Sixty clean male Sprague-Dawley (SD) rats were randomly divided into three groups: normal control group (GN, 8 rats), hepatic fibrosis model group (GC, 28 rats) and IL-10 treated group (GI, 24 rats). At the beginning of the 7th and 11th wk, rats in each group were routinely perfused with pronase E and type IV collag-enase through a portal vein catheter and the suspension obtained from the liver was spun by centrifugation with 11% Nycodenz density gradient to isolate HSCs. Histological examination was used to determine the degree of hepatic fibrosis. RT-PCR was employed to analyze mRNA expression from freshly isolated cells. Immunocytochemistry was performed to detect protein expression in primary cultured HSCs. RESULTS: Rat hepatic fibrosis was developed with the increase of injection frequency of CCl4, and HSCs were successfully isolated. At the 7th and 11th wk, TGF-β1, EGF, and HGF mRNA in GC increased obviously compared with GN (P= 0.001/0.042, 0.001/0.001, 0.001/0.001) and GI (P=0.001/0.007, 0.002/0.001, 0.001/0.001). For TGF-β1, no difference was observed between GI and GN. For EGF, mRNA level in GI increased compared with GN during the 7th wk (P=0.005) and 11th wk (P=0.049). For HGF, mRNA level in GI decreased compared with GN at the 7th wk (P=0.001) and 11th wk (P=0.021). Between these two time points, TGF-β1 expression at the 7th wk was higher than that of the 11th wk (P=0.049), but for EGF, the former was lower than the latter (P=0.022). As for PDGF mRNA, there was no significant difference between these groups, but difference seemed to exist in protein levels. Results by immunocytochemistry of TGF-β1 and EGF were paralleled with the above findings. CONCLUSION: The expression of TGF-β1, EGF and HGF increased in HSC of hepatic fibrosis rat and decreased after treatment with IL-10. IL-10 plays an anti-fibrogenic role by suppressing growth factors expression.     

Resistin mediates the hepatic stellate cell phenotype

AIM: To describe the role of resistin in liver fibrosis. METHODS: For the in vivo animal study, Sprague Dawley rats were subjected to bile duct ligation (BDL) for 4 wk. Rat liver, adipose tissue (epididymal fat) and serum were analyzed for resistin expression. For the in vitro experiment, rat primary hepatic stellate cells (HSCs) and Kupffer cells (KCs) were used. HSCs were exposed to recombinant resistin, and collagenⅠ, transforming growth factor β1, α smooth muscle actin, tissue inhibitor of metalloproteinase 1 and connective tissue growth factor expression were analyzed. Resistin gene and protein expression was quantified as was the expression of pro-inflammatory cytokines including tumor necrosis factor α (TNFα), interleukin (IL)-1, IL-6, IL-8 and monocyte chemotactic protein-1 (MCP-1). The effects of resistin on HSC proliferation, migration and apoptosis were determined. The effects of resistin on KCs were also investigated. RESULTS: Following BDL, rat epididymal fat and serum rather than liver showed higher resistin expression compared to control rats. In liver, resistin was expressed in quiescent HSCs and KCs. Resistin treatment resulted in enhancement of TNFα , IL-6 , IL-8 and MCP-1 gene expression and increased IL-6 and MCP-1 protein in HSCs. Resistin activated HSC phospho-MAPK/p38, and p38 inhibition diminished IL-6 and MCP-1 expression. Furthermore, resistin facilitated HSC proliferation and migration, but decreased apoptosis which was via an IL-6 and MCP-1 mechanism. Finally, resistin-induced transforming growth factor β1 from KCs enhanced HSC collagenⅠexpression. CONCLUSION: Resistin directly and indirectly modulates HSC behavior towards a more pro-fibrogenic phenotype.     

Tetrandrine inhibits activation of rat hepatic stellate cells in vitro via transforming growth factor-β signaling

AIM: To investigate the effect of various concentrations of tetrandrine on activation of quiescent rat hepatic stellate cells (HSCs) and transforming growth factor-β(TGF-β) signaling in vitro. METHODS: HSCs were isolated from rats by in situ perfusion of liver and 18% Nycodenz gradient centrifugation, and primarily cultured on uncoated plastic plates for 24 h with DMEM containing 20% fetal bovine serum (FBS/ DMEM) before the culture medium was substituted with 2% FBS/DMEM for another 24 h. Then, the HSCs were cultured in 2% FBS/DMEM with tetrandrine (0.25, 0.5, 1, 2 mg/L, respectively). Cell morphological features were observed under an inverted microscope, smooth muscle-α-actin (α-SMA) was detected by immunocytochemistry and image analysis system, laminin (LN) and type Ⅲ procollagen (PCⅢ) in supernatants were determined by radioimmunoassay. TGF-β1 mRNA, Smad 7 mRNA and Smad 7 protein were analyzed with RT-PCR and Western blotting, respectively. RESULTS: Tetrandrine at the concentrations of 0.25-2 mg/L prevented morphological transformation of HSC from the quiescent state to the activated one, while α-SMA, LN and PCⅢ expressions were inhibited. As estimated by gray values, the expression of α-SMA in tetrandrine groups (0.25, 0.5, 1, 2 mg/L) was reduced from 21.3% to 42.2% (control: 0.67, tetrandrine groups: 0.82, 0.85, 0.96, or 0.96, respectively, which were statistically different from the control, P<0.01), and the difference was more significant in tetrandrine at 1 and 2 mg/L. The content of LN in supernatants was significantly decreased in tetrandrine groups to 58.5%, 69.1%, 65.8% or 60.0% that of the control respectively, and that of PCⅢ to 84.6%, 81.5%, 75.7% or 80.7% respectively (P<0.05 vs control), with no significant difference among tetrandrine groups. RT-PCR showed that TGF-β1 mRNA expression was reduced by tetrandrine treatments from 56.56% to 87.90% in comparison with the control, while Smad 7 mRNA was increased 1.4-4.8 times. The TGF-β1 mRNA and Smad 7 mRNA expression was in a significant negative correlation (r= -0.755, P<0.01), and both were significantly correlated with α-SMA protein expression (r= -0.938, P<0.01; r = 0.938,P<0.01, respectively). The up-regulation of Smad 7 protein by tetrandrine (1 mg/L) was confirmed by Western blotting as well. CONCLUSION: Tetrandrine has a direct inhibiting effect on the activation of rat HSCs in culture. It up-regulates the expression of Smad 7 which in turn blocks TGF-β1 expression and signaling.     

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

AIM:To study the effects of Kupffer cell-conditioned medium(KCCN)derived from lipopolysaccharide(LPS)treatment onproliferation of rat hepatic stellate cells(HSC).METHODS:HSC and Kupffer cells were isolated from theliver of Wistar rats by in situ perfusion with pronase andcollagenase and density gradient centrifugation with Nycodenzand cultured.KCCM was prepared and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)colorimetricassay was used to detect HSC proliferation.The content oftype Ⅳ collagen and laminin secreted by HSC in the HSC-conditioned medium was determined by radioimmunoassay.TGF-β_1 production in the KCCM was detected by enzyme-linked immunosorbent assay(ELISA).RESULTS:HSC and Kupffer cells isolated had high purity.One microgram per mililiter LPS-activated KCCM andunstimulated KCCM could significantly promote HSCproliferation[0.132±0.005 and 0.123±0.008 vscontrol group(0.100±0.003),P<0.01],and there was a difference betweenthem(P<0.05).Ten microgram per mililiter LPS-activatedKCCM(0.106±0.010)was unable to promote HSC proliferation(P>0.05).Adding anti-TGF-β_1 antibodies could suppress theproliferation promoted by unstimulated KCCM and LPS(1μg/ml)-activated KCCM(0.109±0.009 vs 0.123±0.008,0.115±0.008 vs 0.132±0.005,P<0.01).LPS(1μg/ml or 10μg/ml)could not promote HSC proliferation immediately(0.096±0.003 and 0.101±0.004 vs 0.100±0.003,P>0.05).Therewas a parallel behavior between HSC proliferation and increasedECM level.One microgram per mililiter LPS-activated KCCNcontained a larger amount of TGF-β_1 than unstimulated KCCM.CONCLUSION:The technique for isolation of HSC andKupffer cells described here is simple and reliable.KCCMstimulated by LPS may promote HSC proliferation and collagenaccumulation,which are associated with hepatic fibrogenesis.     

Bone morphogenetic protein-7 represses hepatic stellate cell activation and liver fibrosis via regulation of TGF-β/Smad signaling pathway

BACKGROUND Liver fibrosis is a refractory disease whose persistence can eventually induce cirrhosis or even liver cancer.Early liver fibrosis is reversible by intervention.As a member of the transforming growth factor-beta(TGF-β)superfamily,bone morphogenetic protein 7(BMP7)has anti-liver fibrosis functions.However,little is known about BMP7 expression changes and its potential regulatory mechanism as well as the relationship between BMP7 and TGF-βduring liver fibrosis.In addition,the mechanism underlying the anti-liver fibrosis function of BMP7 needs to be further explored.AIM To investigate changes in the dynamic expression of BMP7 during liver fibrosis,interactions between BMP7 and TGF-β1,and possible mechanisms underlying the anti-liver fibrosis function of BMP7.METHODS Changes in BMP7 expression during liver fibrosis and the interaction between BMP7 and TGF-β1 in mice were observed.Exogenous BMP7 was used to treat mouse primary hepatic stellate cells(HSCs)to observe its effect on activation,migration,and proliferation of HSCs and explore the possible mechanism underlying the anti-liver fibrosis function of BMP7.Mice with liver fibrosis received exogenous BMP7 intervention to observe improvement of liver fibrosis by using Masson’s trichrome staining and detecting the expression of the HSC activation indicator alpha-smooth muscle actin(α-SMA)and the collagen formation associated protein type I collagen(Col I).Changes in the dynamic expression of BMP7 during liver fibrosis in the human body were further observed.RESULTS In the process of liver fibrosis induced by carbon tetrachloride(CCl4)in mice,BMP7 protein expression first increased,followed by a decrease;there was a similar trend in the human body.This process was accompanied by a sustained increase in TGF-β1 protein expression.In vitro experiment results showed that TGF-β1 inhibited BMP7 expression in a time-and dose-dependent manner.In contrast,high doses of exogenous BMP7 inhibited TGF-β1-induced activation,migration,and proliferation of HSCs;this inhibitory effect was associated with upregulation of pSmad1/5/8 and downregulation of phosphorylation of Smad3 and p38 by BMP7.In vivo experiment results showed that exogenous BMP7 improved liver fibrosis in mice.CONCLUSION During liver fibrosis,BMP7 protein expression first increases and then decreases.This changing trend is associated with inhibition of BMP7 expression by sustained upregulation of TGF-β1 in a time-and dose-dependent manner.Exogenous BMP7 could selectively regulate TGF-β/Smad pathway-associated factors to inhibit activation,migration,and proliferation of HSCs and exert antiliver fibrosis functions.Exogenous BMP7 has the potential to be used as an antiliver fibrosis drug.     

Suppressive effects of 171β-estradiol on hepatic fibrosis in CCI4-induced rat model

AIM: To investigate the pathway via which 17β-estradio(β-Est) exerts suppressive effects on rat hepatic fibrosis.METHODS: In vivo study was done in CCI4-induced female hepatofibrotic rats. Fibrosis-suppressive effect of β-Est(20 μg/kg&#183;d) was evaluated in intact and ovariectomized rat models. Six weeks after the treatment, all the rats were sacrificed and specimens of serum or liver tissue were collected for the studies. Serum liver enzymes,fibrosis markers and estradiol levels were determined by standard enzymatic methods, ELISA and RIA, respectively.Degrees of fibrosis and areas of hepatic stellate cells(HSCs) positive for alpha-smooth muscle actin (a-SMA) in the liver were determined by van Gieson (VG) stain and immunohistochemistry. In vitro studies, HSCs were isolated by a combination of pronase-collagenase perfusion and density gradient centrifugation. First-passage HSCs were randomly divided into 10 groups, and different concentrations of β-Est, 2-hydroxyestradiol (2OHE) or 2-methoxyestradiol(2MeOE) were separately added to the cell groups. After incubation for 72 h, the degree of cell proliferation, collagen production, ~-SMA or estrogen receptor (ER) expression was determined by MTT assay, ELISA and immunohistochemistry,respectively.RESULTS: β-Est treatment reduced aspartate aminotransfer-ase (AST), alanine aminotransferase (ALT), hyaluronic acid(HA) and type IV collagen (C IV) in sera, suppressed hepatic collagen content, decreased the areas of HSCs positive for α-SMA significantly in both intact and ovariectomized female hepatofibrotic rats. There was a negative correlation between the percentage of fibrotic area of liver tissue and the serum estradiol level; the calculated correlation coefficient was -0.57 (P&lt;0.01). β-Est and its metabolites concentration-dependently (10^-9 mol/L-10^-7 mol/L) inhibited HSC proliferation and collagen synthesis. At the concentration of 10^-7 mol/L, they could inhibit α-SMA expression. The order of potency was 2MeOE&gt;2OHE&gt;β-Est.CONCLUSION: β-Est may suppress hepatic fibrosis probably via its biologically active metabolites.     

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

AIM:To study the effects of Kupffer cell-conditioned medium (KCCM) derived from lipopolysaccharide (LPS) treatment on proliferation of rat hepatic stellate cells (HSC).METHODS:HSC and Kupffer cells were isolated from the liver of Wistar rats by in situ perfusion with pronase and collagenase and density gradient centrifugation with Nycodenz and cultured. KCCM was prepared and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay was used to detect HSC proliferation. The content of type Ⅳ collagen and laminin secreted by HSC in the HSC-conditioned medium was determined by radioimmunoassay.TGF-β1 production in the KCCM was detected by enzymelinked immunosorbent assay (ELISA).RESULTS:HSC and Kupffer cells isolated had high purity.One microgram per mililiter LPS-activated KCCM and unstimulated KCCM could significantly promote HSC proliferation [0.132&#177;0.005 and 0.123&#177;0.008 vscontrol group (0.100&#177;0.003), P&lt;0.01], and there was a difference between them (P&lt;0.05). Ten microgram per mililiter LPS-activated KCCM (0.106&#177;0.010) was unable to promote HSC proliferation (P&gt;0.05). Adding anti-TGF-β1 antibodies could suppress the proliferation promoted by unstimulated KCCM and LPS(1μg/ml)-activated KCCM (0.109&#177;0.009 vs 0.123&#177;0.008,0.115&#177;0.008 vs 0.132&#177;0.005, P&lt;0.01). LPS (1μg/ml or 10μg/ml) could not promote HSC proliferation immediately (0.096&#177;0.003 and 0.101&#177;0.004 vs 0.100&#177;0.003, P&gt;0.05). There was a parallel behavior between HSC proliferation and increased ECM level. One microgram per mililiter LPS-activated KCCM contained a larger amount of TGF-β1 than unstimulated KCCM.CONCLUSION:The technique for isolation of HSC and Kupffer cells described here is simple and reliable. KCCM stimulated by LPS may promote HSC proliferation and collagen accumulation, which are associated with hepatic fibrogenesis.     

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

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

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

AIM：Hepatic stellate cell(HSC)plays a pivotal role in liver fibrosis and is considered as the therapeutic target for the treatment of hepatic fibrosis,Tyrosine protein kinase plays an important role in the proliferation,activation of HSC.The purpose of the study is to investigate the effects of the tyosine protein kinase inhibitor genistein on the proliferation and activation of cultured rat HSC.METHODS:Rat HSC were isolated from Wistar rats by in situ perfusion of collagenase and pronase and single-step density Nycodenz gradient,Culture-activated HSC were serum-starved and incubated with10^-9to10^-5mol/L concentration of genistein for 24,48or 72h,In PDGF-induced HSC proliferation,HSC were stimulated with10μg&#183;L^-1PDGF-BBfo15min,and thentreated with genistein for the same time.Cell proliferation was measured by MПassay and based on flow cytometric analysis of cell cycle.The a-smooth muscle actin(α-SMA）expression in HSC was studied with confocallaser microscopy and flow cytometry.c-fos,c-jun and cyclinD1expression in HSCwas also detected by flow cytometry.RESULTS:Genistein inhibited basal and PDGF-induced proliferation of HSCat the concentration of 10^-8to10^-5mol/L,and treatment with10^-7mol/L concentration of genistein for 48h inhibited the HSCproliferation significantly(the inhibition rate was 70.3%,P&lt;0.05).Immunofluorescence detected by confocal laser microscopy and flow cytometry showed that treatment with10^-7mol/L genistein for48h suppressed the expression of α-SMA significantly in HSC(the specific fluorescence intensity were60.2&#177;21.5vs35.3&#177;11.6and12.8&#177;10.4vs9.54&#177;6.39,respectively,bothP&lt;0.05).The intensity of c-fos,c-jun and cyclinD1 expression of HSCs treated with 10^-7mol/L genistein for 48h was also significantly decreased compared with the controls.CONCLUSION;Genistein influences proliferation of HSC,suppresses the expression of α-SMA in HSC and tinhibits the intensity of c-fos,c-jun and cyclinD1 expression of HCSs,Genistein has therapeutic potential against liver fibrosis.     

丹参素对大鼠肝星状细胞氨基末端蛋白激酶信号转导的影响

Objective To investigate the inhibitory effect of danshensu on the activation of JNK signaling in rat hepatic stellate cells (HSCs) induced by IL-1 β. Methods The proliferation of primary rat HSCs treated with different concentration of Danshensu was checked by MTT colorimetric assay. The expres-sion and phosphorylation of JNK and P-JNK was detected by western blotting. Synthesis and secretion of collagen Ⅰ were detected by the quantitative immunocytochemical assay and ELISA. Results Danshensu inhibited the proliferation of HSCs in a dose-dependent manner. At the concentration of 0.0625 to 0.25 mmol/L, Danshensu significantly repressed the proliferation of HSC induced by IL-115 (P < 0.05). Synthesis and secretion of Type β collagen was significantly decreased 24 hours after 0.25 mmol/L Danshensu treatment (P < 0.01). The phosphorylation of JNK induced by IL-1 β was significantly inhibited by Danshensu treatment (P < 0.05), however, the expression of JNK was not regulated by Danshensu. Conelutions Danshensu represses the activation and proliferation of HSCs, and inhibits the synthesis and secretion of Type β collagen, possibly via the repression of the JNK signal transduction.     

丹参素对大鼠肝星状细胞氨基末端蛋白激酶信号转导的影响

Objective To investigate the inhibitory effect of danshensu on the activation of JNK signaling in rat hepatic stellate cells (HSCs) induced by IL-1 β. Methods The proliferation of primary rat HSCs treated with different concentration of Danshensu was checked by MTT colorimetric assay. The expres-sion and phosphorylation of JNK and P-JNK was detected by western blotting. Synthesis and secretion of collagen Ⅰ were detected by the quantitative immunocytochemical assay and ELISA. Results Danshensu inhibited the proliferation of HSCs in a dose-dependent manner. At the concentration of 0.0625 to 0.25 mmol/L, Danshensu significantly repressed the proliferation of HSC induced by IL-115 (P < 0.05). Synthesis and secretion of Type β collagen was significantly decreased 24 hours after 0.25 mmol/L Danshensu treatment (P < 0.01). The phosphorylation of JNK induced by IL-1 β was significantly inhibited by Danshensu treatment (P < 0.05), however, the expression of JNK was not regulated by Danshensu. Conelutions Danshensu represses the activation and proliferation of HSCs, and inhibits the synthesis and secretion of Type β collagen, possibly via the repression of the JNK signal transduction.