Dynamic expression of extracellular signal-regulated kinase in rat liver tissue during hepatic fibrogenesis

INTRODUCTION Mitogen-activated protein kinase (MAPK) pathway is an important intracellular signal transduction system[1], and extracellular signal-regulated kinase 1 (ERK1) is the critical and classical pathway of MAPK and plays an important role in sever…     

Diffuse expression of heparan sulfate proteoglycan and connective tissue growth factor in fibrous septa with many mast cells relate to unresolving hepatic fibrosis of congenital hepatic fibrosis.

BACKGROUND AND AIMS: Congenital hepatic fibrosis (CHF) is characterized by dense portal/septal fibrosis and bile duct proliferation and tortuosity. In this study, the roles and significance of fibrosis-related cells and molecules in the process of progressive and unresolving fibrosis of CHF were examined in comparison with other fibrotic liver diseases. METHODS: Seven CHF livers were examined, and a total of 74 control livers (chronic viral hepatitis (CVH), alcoholic fibrosis/cirrhosis (F/C), extrahepatic biliary obstruction and livers showing non-specific reactive changes) were used as controls. All of these livers were wedge biopsied or surgically resected ones, and were formalin fixed and paraffin embedded. In addition to histologic observations, expression of heparan sulfate proteoglycan (HSPG), connective tissue growth factor (CTGF), mast cell-specific tryptase, alpha-smooth muscle actin for activated hepatic stellate cells (HSC) or myofibroblasts (MF) were immunohistochemically surveyed. HSPG and CTGF at mRNA were also examined by in situ hybridization. RESULTS: Portal/septal fibrosis of CHF were mature collagenous and elastic fiber poor, when compared with controls. HSPG and CTGF were diffusely abundant in fibrous portal tracts/septa in CHF, while they were more or less accentuated at periportal areas in alcoholic F/C and CVH. In CHF, the number of interface and portal/septal MF was increased from mild-to-moderate degree, while their increase was moderate to marked in alcoholic F/C and CVH, particularly F3/F4. While activated HSC were frequent in alcoholic F/C and CVH and they were continuous with interface MF, activated HSC in CHF were scanty. Instead, mast cells were increased in portal/septal fibrosis of CHF. Portal mononuclear cells and endothelial cells were positive for HSPG mRNA, and mononuclear cells for CTGF mRNA, and such cells were accentuated around proliferated bile ducts and ductules in CHF. CONCLUSIONS: Abundant CTGF retained diffusely in HSPG in the fibrous portal tracts/septa may be responsible for non-resolving hepatic fibrosis in CHF, and many mast cells and portal MF not related to HSC may causally relate to such characteristic finding in CHF.     

甘草次酸靶向肝星状细胞治疗肝纤维化的体内研究

目的观察以6-磷酸甘露糖修饰的白蛋白(M6P26-HSA)作为特异性载体,将甘草次酸(GA) 靶向释放到肝星状细胞治疗肝纤维化的效果。方法用125I记由M6P26-HSA和GA在体外合成新的偶合物GA-HSA-M6P26,观察其在体内的器官分布情况,用双重免疫组织化学的方法观察星状细胞对GA- HSA-M6P26的选择性摄取;选用Sirius红染色观察GA-HSA-M6P26对肝纤维化时胶原沉积的影响,用定量聚合酶链反应检测GA-HSA-M6P26对Ⅰ型前胶原mRNA表达的影响。结果静脉注射后10min,GA-HSA- M6P26选择性地分布于肝脏,摄取高峰可达(5 5.093±5.404)%。双重免疫组织化学染色证实GA-HSA- M6P26主要被星状细胞选择性摄取,GA-HSA-M6P26治疗后肝脏胶原沉积明显减少,Ⅰ型前胶原和α-平滑肌肌动蛋白mRNA表达明显降低。结论GA-HSA-M6P26可以选择性地分布于肝脏星状细胞,有显著的抗肝纤维化作用。     

大鼠纤维化肝组织中PTEN的动态表达及其与肝星状细胞增殖和活化的关系

目的 探讨第10号染色体缺失的磷酸酶张力蛋白同源物基因(PTEN)在大鼠纤维化肝组织中的动态表达及其对在体肝星状细胞(HSC)活化、增殖的影响. 方法 采用胆总管结扎法建立大鼠肝纤维化模型;应用免疫组织化学染色、Western blot和实时荧光定量PCR技术测定大鼠肝组织中PTEN的表达;应用免疫荧光双标记共聚焦激光扫描显微术测定大鼠肝组织中活化HSC的PTEN表达;采用免疫组织化学染色检测大鼠肝组织中α-平滑肌肌动蛋白的表达.结果 免疫组织化学染色显示正常大鼠肝组织中PTEN有广泛表达,主要表达于细胞质,随着肝纤维化的发展,PTEN表达逐渐减少(P<0.01),而α-平滑肌肌动蛋白阳性细胞明显增多(P<0.01);造模1、2、3周及4周不同时间大鼠纤维化肝组织中PTEN的mRNA(分别为假手术组的0.66、0.53、0.44和0.37)及蛋白质表达(吸光度比值分别为1.20±0.13,1.07±0.16,0.88±0.08,0.73±0.07)均低于假手术组(P<0.01),并随着肝纤维化的进展逐渐降低(P<0.01);免疫荧光双标记共聚焦激光扫描显微术显示PTEN在活化HSC广泛表达,主要表达于细胞质,随着肝纤维化的进展,表达PTEN的活化HSC占总的活化HSC的比例逐渐减少(P<0.01). 结论 大鼠纤维化肝组织中PTEN的mRNA及蛋白质表达均下调;在体HSC的PTEN表达亦降低;肝组织中PTEN的动态表达与HSC的活化、增殖呈显著负相关.     

The intrahepatic biliary epithelium in the guinea pig: is hepatic artery blood flow essential in maintaining its function and structure?

To determine whether hepatic artery blood flow is essential in maintaining the function and structure of bile ductules/ducts, the acute effects of hepatic artery ligation on bile secretion and hepatic ultrastructure were examined in anesthetized, bile duct-cannulated guinea pigs. Sixty minutes after hepatic artery ligation, spontaneous bile flow (5.08 +/- 0.4 microliter per min per gm liver) was virtually the same as that before hepatic artery ligation (5.31 +/- 0.3 microliter per min per gm), as were the choleretic effects of 10 CU per kg per 30 min secretin (7.14 +/- 0.9 vs. 7.21 +/- 0.9 microliter per min per gm), 300 micrograms per kg per 30 min glucagon (6.72 +/- 0.9 vs. 6.59 +/- 0.8 microliter per min per gm) and 60 mumoles per kg per 30 min glycochenodeoxycholate (6.43 +/- 0.6 vs. 6.45 +/- 0.6 microliter per min per gm). The failure of hepatic artery ligation to affect bile secretory function could not be attributed to the existence of collateral arterial blood flow to the liver. First of all, hepatic artery ligation resulted in diminishing significantly hepatic venous, but not portal, oxygen content. More importantly, in isolated guinea pig livers, perfused through the portal vein alone, secretin, glucagon and glycochenodeoxycholate produced changes in bile flow and composition similar to those seen in vivo. Electron microscopy showed no major ultrastructural changes of hepatic parenchyma and biliary epithelium 2 hr after hepatic artery ligation, or 2 hr after perfusing the liver through the portal vein alone save for some portal edema in the latter instance.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of PPARg agonist pioglitazone on rat hepatic fibrosis

AIM: To investigate effects of pioglitazone on rat hepatic fibrosis and to explore its mechanism. METHODS: Rat hepatic fibrosis was induced by carbontet. achloride (CCI4). Forty Sprague-Dawley rats were divided randomly into 4 groups: control, model, and two treatment (PⅠ, PⅡ) groups. Except for rats in control group, all rats were given subcutaneous injection of 400 mL/L CCI4, twice a wk for 8 wk. Rats in PⅠ and PⅡ groups were also treated with pioglitazone of 3 mg/kg, daily via gastrogavage beginning on the 1^st day and at the end of the 2^nd week, administration of CCI4 respectively. Liver functions (ALT, AST), serum fibrotic markers (HA, LN, PCIII) and hepatic hydroxyproline (HP) concentration were determined respectively. Histochemical staining of formalin-fixed liver sections with HE, Masson-Trichrome, and immunohistochemical staining for m-smooth muscle actin (α-SMA) were performed. Modified Knodell and Chevallier semi-quantitative scoring system (SSS) was used to evaluate necroinflammatory activity and fibrosis degree. RESULTS: Compared with model group, pioglitazone significantly reduced the serum levels of ALT, AST, HA, LN and PCⅢ (P&lt;0.05 or &lt;0.01). The HP concentrations in PⅠ(210.90&#177;24.07 μg/g), and PⅡ (257.36&#177;30.55 μg/g) groups were also lower than those in model group (317.80&#177;36.44) μg/g) (P&lt;0.01). Histologic examination showed that PⅠ and PⅡ groups had milder hepatocellular degeneration, necrosis and infiltration of inflammatory cells, and thinner or less fibrotic septa than did model group. The scores for necroinflammation in P (2.80&#177;1.03), and PⅡ (3.00&#177;1.05) groups were significantly reduced as compared with model group (4.88&#177;2.30) (P&lt;0.05 or &lt;0.01); the fibrosis scores in PⅠ (3.40&#177;1.65), and PⅡ (4.60&#177;1.35) groups were also markedly lower than those in model group (7.00&#177;3.21) (P&lt;0.05 or &lt;0.01). Immunohistochemical staining showed that expression of α-SMA in PⅠ and PⅡ groups was ameliorated dramatically compared with model group. CONCLUSION: PPARγ, agonist pioglitazone greatly retards the progression of rat hepatic fibrosis induced by CCI4 through inhibition of HSC activation and amelioration of hepatocyte necroinflammation in rats.     

Cellular retinol-binding protein-1 expression in normal and fibrotic/cirrhotic human liver: different patterns of expression in hepatic stellate cells and (myo)fibroblast subpopulations

BACKGROUND/AIMS: Cellular retinol-binding protein-1 (CRBP-1) which is involved in vitamin A metabolism is highly expressed in liver cells, particularly in hepatic stellate cells (HSCs). In this work, the CRBP-1 expression was studied by immunohistochemistry in the different liver cell populations, including HSCs and portal fibroblasts, of normal liver and of fibrotic and cirrhotic liver. METHODS: Normal liver, fibrotic liver in different stages and cirrhotic liver sections were studied. Immunohistochemistry was performed using antibodies against CRBP-1, alpha-smooth muscle actin (SMA), CD 68 and CD 34. RESULTS: In normal liver, quiescent HSCs expressed CRBP-1, while portal fibroblasts did not. In fibrotic or cirrhotic liver, activated HSCs co-expressed CRBP-1 and alpha-SMA; a variable proportion of portal and septal (myo)fibroblasts, more important in cirrhosis, neo-expressed both CRBP-1 and alpha-SMA. Biliary epithelial cells both in normal and pathological situations expressed CRBP-1. Neither Kupffer cells, nor endothelial cells showed CRBP-1 expression. CONCLUSIONS: Our study demonstrates that CRBP-1 is a good marker to identify HSC in normal human liver. Furthermore, in fibrotic or cirrhotic liver, the different patterns of expression for CRBP-1 and alpha-SMA allow the distinction of different subsets of fibroblastic cells involved in fibrogenesis and septa formation.     

Pro-fibrogenic potential of PDGF-D in liver fibrosis

BACKGROUND/AIMS: We analyzed the expression of platelet-derived growth factor D (PDGF-D) in an experimental bile duct-ligated (BDL) rat model and assessed its biological function in cultured hepatic stellate cells (HSC) and myofibroblasts (MFB). METHODS: The mRNA for PDGF-A, -B, -C, -D and for PDGF receptor-alpha and -beta chains (PDGFRalpha and PDGFRbeta) in normal and fibrotic rat livers was assessed quantitatively. Protein levels of PDGF-D were quantified by immunoblotting and immunohistochemistry. RESULTS: The relative mRNA expression of all PDGF isoforms and receptors upregulated upon BDL and PDGF-A, -B and -D expression was significantly higher than that of PDGF-C. PDGF-D and PDGFRbeta protein also increased markedly. Immunostaining revealed that PDGF-D is localized along the fibrotic septa of the periportal- and perisinusoidal areas. Besides PDGF-B, PDGF-D is the second most potent PDGF isoform in PDGFRbeta signaling within HSC/MFB, evidenced by PDGFRbeta autophosphorylation and activation of the downstream signaling molecules ERK1/2-, JNK-, p38 MAPK, and PKB/Akt while PDGF-C effects were minimal. PDGF-D exerted mitogenic and fibrogenic effects in both cultured HSC and MFB comparable to PDGF-B but PDGF-A and -C showed only marginal fibrogenic effects. CONCLUSIONS: PDGF-D possesses potential pathogenetic properties for HSC activation and matrix remodeling in liver fibrosis.     

Significance of septal fibrosis for disturbance of hepatic circulation.

To examine the significance of fibrous septa of the liver for hepatic circulatory disturbance, haemodynamic changes were investigated in rats with septal fibrosis induced with horse serum injections. The fibrotic liver showed thin fibrous bands originating in the vicinity of the peripheral branches of the hepatic vein connected with each other and partly with the portal triads, without conspicuous periportal, pericentral or perisinusoidal fibrosis. There was no evidence of hepatic cell enlargement, disarrangement of hepatic cell plates or narrowing of the sinusoids in the fibrotic livers. Portal vascular resistance, bile production and hepatic oxygen consumption, which were measured by an isolated liver perfusion method, were much the same in the normal and the fibrotic livers. Moreover, there was no significant difference in in vivo blood pressures of the portal vein, the terminal portal venule, the terminal hepatic venule and the inferior vena cava between the normal and the fibrotic rats. These data suggest that septal fibrosis in itself does not disturb hepatic circulation.     

Significance of septal fibrosis for disturbance of hepatic circulation

Abstract: To examine the significance of fibrous septa of the liver for hepatic circulatory disturbance, haemodynamic changes were investigated in rats with septal fibrosis induced with horse serum injections. The fibrotic liver showed thin fibrous bands originating in the vicinity of the peripheral branches of the hepatic vein connected with each other and partly with the portal triads, without conspicuous periportal, pericentral or perisinusoidal fibrosis. There was no evidence of hepatic cell enlargement, disarrangement of hepatic cell plates or narrowing of the sinusoids in the fibrotic livers. Portal vascular resistance, bile production and hepatic oxygen consumption, which were measured by an isolated liver perfusion method, were much the same in the normal and the fibrotic livers. Moreover, there was no significant difference in in vivo blood pressures of the portal vein, the terminal portal venule, the terminal hepatic venule and the inferior vena cava between the normal and the fibrotic rats. These data suggest that septal fibrosis in itself does not disturb hepatic circulation.     

Albumin modified with mannose 6-phosphate: A potential carrier for selective delivery of antifibrotic drugs to rat and human hepatic stellate cells

The hallmark of liver fibrosis is an increased extracellular matrix deposition, caused by an activation of hepatic stellate cells (HSC). Therefore, this cell type is an important target for pharmacotherapeutic intervention. Antifibrotic drugs are not efficiently taken up by HSC or may produce unwanted side-effects outside the liver. Cell-specific delivery can provide a solution to these problems, but a specific drug carrier for HSC has not been described until now. The mannose 6-phosphate/insulin-like growth factor II (M6P/IGF-II) receptor, which is expressed in particular upon HSC during fibrosis, may serve as a target-receptor for a potential carrier. The aim of the present study was to examine if human serum albumin (HSA) modified with mannose 6-phosphate (M6P) is taken up by HSC in fibrotic livers. A series of M6Px-modified albumins were synthetized: x = 2, 4, 10, and 28. Organ distribution studies were performed to determine total liver uptake. The hepatic uptake of M6Px-HSA increased with increasing M6P density. M6Px-HSA with a low degree of sugar loading (x = 2-10) remained in the plasma and accumulated for 9% +/- 0.5% or less in fibrotic rat livers. An increase in the molar ratio of M6P:HSA to 28:1 caused an increased liver accumulation to 59% +/- 9% of the administered dose. Furthermore, we determined quantitatively the in vivo intrahepatic distribution of M6Px-HSA using double-immunostaining techniques. An increased substitution of M6P was associated with an increased accumulation in HSC; 70% +/- 11% of the intrahepatic staining for M6P28-HSA was found in HSC. We also demonstrate that M6P-modified bovine serum albumin (BSA) accumulates in slices of normal and cirrhotic human livers. After incubation of this neoglycoprotein with human tissue, the protein is found in nonparenchymal liver cells. Because M6P-modified albumins are taken up by HSC in fibrotic livers, this neoglycoprotein can be applied as a selective drug carrier for HSC. This technology may create new opportunities for the pharmacological intervention of liver fibrosis.     

Hepatic content of collagens and laminin in rat model of experimental liverfibrosis

AIM The hepatic content of collagens (type I, Ⅲ and Ⅶ) and laminin (LN) in rat model of experimentalliver fibrosis was observed to find out their roles in the pathogenesis of liver fibrosis.METHODS The experimental rat model was established by immunological injury induced by injectinghuman albumin. Histopathological and immunohistochemical methods were used to measure the hepaticcontent of collagens and laminin in the fibrotic rat livers.RESULTS The hepatic contents of collagens (type I, Ⅲ, Ⅶ) and LN in the fibrotic rat livers weresignificantly increased as compared with those in the control group, and they were found to be mainlylocalized in the portal space, central veins and fibrous septa. Electron microscopic study showed that pro-collagens were present around the “activated” hepatic stellate cells (HSC) and the hepatocytes atrophied.CONCLUSION Pathological deposition of collagens (type Ⅰ, Ⅲ and Ⅶ ) and laminin was the fundamentallesion of liver fibrosis. HSC may be the major cellular source of collagens (type Ⅰ, Ⅲ and Ⅶ) and laminin inthe liver tissue.     

内毒素受体在肝星状细胞的表达及其作用

目的了解内毒素受体在肝星状细胞活化中的变化和作用。方法分离正常大鼠的肝星状细胞，以逆转录聚合酶链反应法检测其在体外培养过程中内毒素受体（CD14和TLR4）mRNA的表达变化。以细胞免疫染色法检测肝星状细胞内毒素受体CD14的表达。制作肝纤维化和肝硬化的大鼠模型，免疫组织化学法动态检测肝组织内CD14和α平滑肌肌动蛋白的表达变化和定位。结果初分离的肝星状细胞表达低水平的CD14 mRNA，不表达TLR4 mRNA，培养活化的肝星状细胞内毒素受体的表达增强，内毒素可上调这种表达。体外培养10d的肝星状细胞表达CD14蛋白，内毒素作用后CD14表达更明显。在肝纤维化的发展过程中，肝组织内CD14阳性细胞增多，阳性细胞多分布于肝窦周围，晚期CD14阳性细胞聚集在纤维隔内，与α平滑肌肌动蛋白阳性细胞的分布一致。结论肝星状细胞在体内外的活化过程中内毒素受体的表达增强，因此，内毒素受体可能参与肝星状细胞在肝脏炎症和纤维化中的作用。     

原肌球蛋白1在大鼠肝纤维化模型及肝星状细胞中的动态表达及其意义

目的 观察原肌球蛋白1 (TPMl)在大鼠肝纤维化模型及肝星状细胞(HSC)中的动态表达.方法 将SD大鼠随机分为正常对照组(6只)和模型组(24只).二甲基亚硝胺腹腔注射建立大鼠肝纤维化模型,于第2、4、6、8周(每组各6只)门静脉采血及取肝组织标本; HSC-T6细胞设对照组及刺激组,刺激组以5 ng/ml转化生长因子β 1(TGF β 1)作用48h.苏木素-伊红和Masson染色观察肝组织病理变化,RT-PCR、免疫组织化学和Western blot检测组织与细胞中TPMl,TGF β1及α平滑肌肌动蛋白(α-SMA)的mRNA和蛋白的表达,以及TPMl在肝组织中的定位.两样本均数比较采用独立样本t检验;相关性采用Pearson直线相关分析.结果 成功建立肝纤维化模型,TPMl在正常肝组织中低表达于汇管区血管内皮上,在模型组TPMl强表达于增生的肝纤维间隔,TPMl及α-SMA的mRNA及蛋白的表达在肝纤维化过程中均逐渐升高,6周时高于其他各组,8周时下降,与对照组相比,差异均有统计学意义(P＜ 0.05);TGF β 1先升高,4周时高于其他各组,6周时下降(P＜0.05);相关性分析表明TPMl与o-SMA和TGF β 1的表达均呈正相关(rs=0.688和rs=0.692,P＜0.01); HSC-T6细胞中,TGF β 1刺激组TPM1及α- SMA的mRNA表达均升高,差异有统计学意义(P＜0.05).结论 TPMl参与了肝纤维化的发生和发展过程,有望成为肝纤维化诊断与治疗的新靶点.     

Role of hepatic stellate cell/hepatocyte interaction and activation of hepatic stellate cells in the early phase of liver regeneration in the rat

BACKGROUND/AIMS: Hepatic stellate cells (HSCs) are known to play a role in hepatic regeneration. We investigated hepatocyte/HSC interaction and HSC activation at various times after 70% partial hepatectomy (PHx) in the rat. METHODS: The hepatic microcirculation was studied using intravital fluorescence microscopy (IVFM). Desmin and alpha-SMA within liver tissue were detected by immunohistochemistry. In isolated parenchymal liver cells (PLCs) and HSCs, double immunostaining was used to identify activated HSC. RESULTS: Using IVFM, hepatocyte-clusters were often seen in vivo at 3 days after PHx (PHx3). Distance between HSC fell from 61.7+/-2.1 microm in controls to 36.1+/-1.4 microm (P<0.001) while the HSC/hepatocyte ratio rose (0.71+/-0.01 to 1.08+/-0.03; P<0.001). In >80% of in vivo microscopic fields in the PHx3 group, clusters of HSCs were observed especially near hepatocyte-clusters. At PHx1 and PHx3, >20% of cells in the PLC-fraction were HSCs which adhered to hepatocytes. At PHx3, in addition to desmin staining, isolated HSCs were also positive for BrdU and alpha-SMA, and formed clusters. HSCs in the HSC-fraction were only positive for desmin which indicated that adherence to hepatocytes is required for HSC activation. CONCLUSIONS: Our data suggest that HSCs are activated by adhering to hepatocytes in the early phase of liver regeneration.     

整合素αvβ3在肝星状细胞和肝纤维化组织中的表达

目的 研究整合素avβ3在肝星状细胞和纤维化肝组织中的表达,探讨能反映肝星状细胞活化状态的表型受体.方法 分离大鼠肝星状细胞,体外培养激活.硫代乙酰胺175 mg/kg每周2次,连续12周腹腔注射诱导大鼠肝纤维化.免疫染色观察细胞和组织中整合avβ3和a-平滑肌肌动蛋白(a-SMA)的表达.实时PCR和Western印迹法分析avβ3在星状细胞中、正常和肝纤维化组织中的表达.结果 活化星状细胞中avβ3表达明显上调,与第1天相比,第14天的mRNA和蛋白质水平分别增加18倍和5.2倍.免疫染色整合素avβ3成簇极性表达于活化星状细胞的胞膜.肝纤维化模型中avβ3在mRNA和蛋白水平明显高于正常对照(t=2.39,P＜0.05;t=2.74,P＜0.05),正常肝组织中a-SMA和avβ3局限表达于门静脉周围,肝纤维化组织中a-SMA和avβ3表达于扩大的门管区和纤维间隔.结论 体内外活化星状细胞中整合素avβ3表达水平上调,它是星状细胞活化的表型受体,参与肝纤维化的发生.     

转化生长因子β1对不同活化状态肝星状细胞增殖与Ⅰ型胶原表达的影响

目的 观察不同活化状态肝星状细胞(HSC)对外源性转化生长因子-β_1(TGF-β_1)旁分泌刺激的生物学效应作用。方法 原代分离培养大鼠HSC,无包被塑料培养皿上分别培养1、4、7d,细胞处于静止、中间活化与完全活化状态,继以10～500 pmol/L TGF-β_1温育细胞24h,~3H—TdR掺入法测定细胞增殖,western blot法检测细胞α-平滑肌肌动蛋白(α-SMA)与Ⅰ型胶原蛋白表达沉积,~3H-脯氨酸掺入与胶原酶消化法测定细胞总胶原的分泌量。100pmol/L TGF-β_1温育细胞15～90min,northern blot法检测细胞Ⅰ型前胶原mRNA的表达水平。结果 TGF-β_1浓度依赖性抑制培养1d HSC的细胞增殖,10～500 pmol/L TGF-β_1浓度组细胞内~3H—TdR掺入率分别为对照组的52.8％～16.8％,与对照组比较,q值为5.44～10.37,P<0.01。但TGF-β_1对培养4d与7d的细胞增殖无影响。随细胞活化,HSC基础性α-SMA、Ⅰ型胶原蛋白与mRNA水平明显增加,而TGF-β_1刺激各培养时间HSC以上蛋白与基因的表达。培养1、4、7d HSC基础水平与TGF-β_1刺激的总胶原分泌量分别为(804±274)dpm/孔与(1 200±708)dpm/孔;(2 966±1 701)dpm/孔与(6 160±1 123)dpm/孔;(2 580±767)dpm/孔与(4 583±1 467)dpm/孔,后2组组内比较,t值分别为3.84与2.96,P<0.01或P<0.05。以培养4d HSC