Value of α-smooth muscle actin and glial fibrillary acidic protein in predicting early hepatic fibrosis in chronic hepatitis C virus infection

Introduction

α-Smooth muscle actin (α-SMA)-positive hepatic stellate cells (HSCs) are pericytes responsible for fibrosis in chronic liver injury. The glial fibrillary acidic protein (GFAP), commonly expressed by astrocytes in the central nervous system, is expressed in vivo in the liver in a subpopulation of quiescent stellate cells. The reports concerning GFAP expression in human liver are still conflicting. The aim of the study is investigation the utility of GFAP compared to α-SMA as an indicator of early activated HSCs, in predicting fibrosis in chronic hepatitis C (CHC) patients.

Material and methods

With immunohistochemistry and a semi-quantitative scoring system, the expressions of α-SMA and GFAP on HSCs in liver biopsies from patients with pure CHC (n = 34), hepatitis C virus-induced cirrhosis (n = 24), mixed CHC/schistosomiasis (n = 11) and normal controls (n = 10) were analysed.

Results

The immunoreactivity of α-SMA and GFAP in perisinusoidal, periportal and pericentral areas was assessed. α-Smooth muscle actin and GFAP-positive HSCs were significantly increased in all diseased groups compared with normal controls. In pure CHC with or without cirrhosis, perisinusoidal α-SMA-positive HSCs were predominant in relation to GFAP-positive cells. On the other hand, GFAP-positive cells were predominant in the group of schistosomiasis as compared with the other diseased groups. It was noticed that expression of GFAP on perisinusoidal HSCs in CHC patients sequentially decreased with the progression of fibrosis.

Conclusions

Glial fibrillary acidic protein could represent a more useful marker than α-SMA of early activation of HSCs in CHC patients and seems to be an early indicator of hepatic fibrogenesis.     

miR-144 regulates transforming growth factor-β1 iduced hepatic stellate cell activation in human fibrotic liver

Objectives: Activation of hepatic stellate cells (HSCs) into collagen producing myofibroblasts is critical for pathogenesis of liver fibrosis. Transforming growth factor-β1 (TGF-β1) is one of the main profibrogenic mediators for HSC transdifferentiation. Recent studies have shown effect of microRNAs (miRNAs) on regulating TGF-β1-induced HSC activation during liver fibrosis. Here, we aimed to explore the roles of miR-144 and miR-200c in human liver fibrosis. Methods: Expression of TGF-β1 was detected in 42 fibrotic and 18 normal human liver tissues by quantitative real time polymerase chain reaction (qRT-PCR) and immunohistochemistry, and its correlation with α-smooth muscle actin (α-SMA) was calculated. miR-144 and miR-200c expression level in fibrotic liver tissues were also detected by qRT-PCR. The correlation of TGF-β1 expression with miR-200c and miR-144 in the fibrotic liver was analyzed. Results: The results showed that TGF-β1 expression was much higher in fibrotic liver than that in normal liver tissues (P<0.05). TGF-β1 protein high expressing liver fibrosis showed α-SMA positive cells in the liver parenchyma indicating activated HSCs. Expression of TGF-β1 in fibrotic liver was significantly correlated with α-SMA expression (R=0.633, P<0.001). Furthermore, miR-144 was less expressed in liver fibrosis (P<0.05) and was significantly correlated with expression of TGF-β1 in fibrotic liver tissues (R=-0.442, P<0.01). However, miR-200c did not show significant difference between normal and fibrotic liver (P=0.48) and correlation with TGF-β1 expression (R=0.106, P=0.51). Conclusion: All the results indicate that miR-144 can be a novel regulator of TGF-β1-induced HSC activation during liver fibrosis.     

Antifibrotic potential of a selective COX-2 inhibitor (celecoxib) on liver fibrosis in rats

Hepatic stellate cells (HSCs) play a critical role in the fibrogenesis of the liver, so they are the target cells of antifibrotic therapy. Activated HSCs, but not quiescent HSCs, express cyclooxygenase-2 (COX-2). The present study was designed to investigate the possible prophylactic and therapeutic effects of a selective COX-2 inhibitor (celecoxib) on liver fibrosis induced by thioacetamide (TAA) in rats. Forty-two male albino rats were divided into five groups: group I, negative control; group II, model of fibrosis; group III, preventive model before induction of fibrosis where celecoxib was given for 4 weeks before TAA; group IV, preventive model at the time of induction of fibrosis where celecoxib was given concomitantly with TAA for 6 weeks; group V, therapeutic model treated after induction of fibrosis. Liver function tests, serum TGF-β1 (ELISA), and histopathological examination of liver sections were performed. Both Metavir and Ishak fibrosis scoring systems were used for the evaluation of fibrosis. Groups III, IV, and V showed significant amelioration of liver function tests and a decrease in serum TGF-β1 as compared to the fibrosis model group (II). Histopathological examination showed the mildest degree of fibrosis in group III. Celecoxib had a hepatoprotective and therapeutic effect against liver damage produced by TAA but with different degrees. The highest efficacy of celecoxib was in the preventive group (III) before time of induction of liver fibrosis, followed by the therapeutic group (V) and then the preventive group (IV) at time of induction of liver fibrosis.     

TET3 mediates the activation of human hepatic stellate cells via modulating the expression of long non-coding RNA HIF1A-AS1

Activated Hepatic stellate cells (HSCs) play a critical role in liver fibrosis and a lot of efforts have been made to dissect the underlying mechanism involved in activation of HSCs. However, the underlying mechanism remains douteux up to now. In the present study, we found that TET3, one member of ten-eleven translocation (TET) protein family, reduced significantly in HSCs LX-2 activated by TGF-β1. To study the function of TET3 in activation of HSCs, knockdown was performed by RNA interference. Results showed that cell proliferation rise significantly and cell apoptosis reduce obviously after knockdown of TET3. Meanwhile, IHC showed that the expression of α-SMA rise significantly compared to control. These results indicated that TET3 is closely associated with the activation of HSCs. Further studies found that long non-coding RNA HIF1A-AS1 was reduced significantly in LX-2 cell after treatment with siRNA for TET3. The result hinted that TET3 activate HSCs through modulating the expression of HIF1A-AS1. To confirm this hypothesis, RNA interference was performed to silence the HIF1A-AS1. Results showed that HIF1A-AS1 silencing lead to enhancing in cell proliferation and declining apoptosis. Taken together, TET3 can mediate the activation of HSCs via modulating the expression of the long non-coding RNA HIF1A-AS1.     

抗IGFBPrP1抗体对小鼠肝纤维化的预防作用及其机制的研究

目的: 明确抗胰岛素样生长因子结合蛋白相关蛋白1(IGFBPrP1)抗体能否预防硫代乙酰胺(TAA)诱导的小鼠肝纤维化的形成,同时探讨其机制。方法: 将24只雄性C57BL/6野生型小鼠随机分为正常对照组、TAA 4周组和TAA+抗IGFBPrP1抗体4周组,每组8只,观察肝组织形态学改变,免疫组织化学染色和Western blotting检测肝组织中α-平滑肌肌动蛋白(α-SMA)、转化生长因子β₁(TGF-β₁)、Smad3、磷酸化Smad2/3(p-Smad2/3)、纤维连接蛋白(FN)、Ⅰ、Ⅲ型胶原(collagen Ⅰ、Ⅲ)及IGFBPrP1的表达。结果: TAA 4周组肝损伤严重,α-SMA、TGF-β₁、Smad3、p-Smad2/3、FN、collagen Ⅰ、Ⅲ及IGFBPrP1的表达明显高于正常对照组(P＜0.01),TAA+抗IGFBPrP1抗体4周组肝损伤减轻,上述各指标表达均低于TAA 4周组(P＜0.01)。IGFBPrP1与TGF-β₁、Smad3、p-Smad2/3 、FN及collagen Ⅰ的表达呈正相关(P＜0.01)。结论: 抗IGFBPrP1抗体可预防TAA诱导的小鼠肝纤维化的形成,其机制为抑制肝星状细胞的活化和减少细胞核内p-Smad2/3的表达、抑制TGF-β₁/Smad3信号通路,进而导致细胞外基质在肝组织中沉积减少。     

Histone demethylase retinoblastoma binding protein 2 regulates the expression of α-smooth muscle actin and vimentin in cirrhotic livers

Liver cirrhosis is one of the most common diseases of Chinese patients. Herein, we report the high expression of a newly identified histone 3 lysine 4 demethylase, retinoblastoma binding protein 2 (RBP2), and its role in liver cirrhosis in humans. The siRNA knockdown of RBP2 expression in hepatic stellate cells (HSCs) reduced levels of α-smooth muscle actin (α-SMA) and vimentin and decreased the proliferation of HSCs; and overexpression of RBP2 increased α-SMA and vimentin levels. Treatment with transforming growth factor β (TGF-β) upregulated the expression of RBP2, α-SMA, and vimentin, and the siRNA knockdown of RBP2 expression attenuated TGF-β-mediated upregulation of α-SMA and vimentin expression and HSC proliferation. Furthermore, RBP2 was highly expressed in cirrhotic rat livers. Therefore, RBP2 may participate in the pathogenesis of liver cirrhosis by regulating the expression of α-SMA and vimentin. RBP2 may be a useful marker for the diagnosis and treatment of liver cirrhosis.     

The role of C/EBP-α expression in human liver and liver fibrosis and its relationship with autophagy

Aim: To investigate the expression of CCAAT enhancer binding protein-α (C/EBP-α) in normal human liver and liver fibrosis and its probable association with autophagy. Methods: Double label immunohistochemistry was used to detect the location of C/EBP-α in hepatocytes and hepatic stellate cells (HSCs). The expression of C/EBP-α, Atg5, and Atg6 was also evaluated by immunohistochemistry in paraffin sections of human liver. HSC-T6 cells were treated with rapamycin and 3-methyladenine (3MA) to induce or inhibit autophagy, and the expression of C/EBP-α protein was detected by Western blotting. Results: Double label immunohistochemistry showed that C/EBP-α was predominantly located in hepatocytes and that its expression was significantly decreased in fibrosis compared with normal liver. Atg5 expression was increased in fibrosis but was located primarily in liver septa and peri-vascular areas, which was consistent with the distribution of HSCs. In contrast, Atg6 was not expressed in normal or fibrotic liver. Treatment of HSC-T6 cells in culture with rapamycin or 3MA decreased or increased C/EBP-α expression, respectively, as shown by Western blotting. Conclusion: C/EBP-α was primarily expressed in hepatocytes in normal liver, but its expression decreased significantly in liver fibrosis. Autophagy might play a role in liver fibrosis through its association with C/EBP-α, but this hypothesis warrants further investigation.     

Inhibition of hepatic stellate cells by bone marrow-derived mesenchymal stem cells in hepatic fibrosis

Background/Aims

Therapies involving bone-marrow-derived mesenchymal stem cells (BM-MSCs) have considerable potential in the management of hepatic disease. BM-MSCs have been investigated in regenerative medicine due to their ability to secrete various growth factors and cytokines that regress hepatic fibrosis and enhance hepatocyte functionality. The aim of this study was to determine the antifibrosis effect of BM-MSCs on activated hepatic stellate cells (HSCs) and the mechanism underlying how BM-MSCs modulate the function of activated HSCs.

Methods

We used HSCs in both direct and indirect co-culture systems with BM-MSCs to evaluate the antifibrosis effect of BM-MSCs. The cell viability and apoptosis were evaluated by a direct co-culture system of activated HSCs with BM-MSCs. The activations of both HSCs alone and HSCs with BM-MSCs in the direct co-culture system were observed by immunocytochemistry for alpha-smooth muscle actin (α-SMA). The levels of growth factors and cytokines were evaluated by an indirect co-culture system of activated HSCs with BM-MSCs.

Results

The BM-MSCs in the direct co-culture system significantly decreased the production of α-SMA and the viability of activated HSCs, whereas they induced the apoptosis of activated HSCs. The BM-MSCs in the indirect co-culture system decreased the production of transforming growth factor-β1 and interleukin (IL)-6, whereas they increased the production of hepatocyte growth factor and IL-10. These results confirmed that the juxtacrine and paracrine effects of BM-MSCs can inhibit the proliferative, fibrogenic function of activated HSCs and have the potential to reverse the fibrotic process by inhibiting the production of α-SMA and inducing the apoptosis of HSCs.

Conclusions

These results have demonstrated that BM-MSCs may exert an antifibrosis effect by modulating the function of activated HSCs.     

Heparin-binding epidermal growth factor-like growth factor suppresses experimental liver fibrosis in mice

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a cytoprotective agent in several organ systems but its roles in liver fibrosis are unclear. We studied the roles of HB-EGF in experimental liver fibrosis in mice and during hepatic stellate cell (HSC) activation. Thioacetamide (TAA; 100 mg/kg) was administered by intraperitoneal injection three times a week for 4 weeks to wild-type HB-EGF(+/+) or HB-EGF-null (HB-EGF(-/-)) male mice. Livers were examined for histology and expression of key fibrotic markers. Primary cultured HSCs isolated from untreated HB-EGF(+/+) or HB-EGF(-/-) mice were examined for fibrotic markers and/or cell migration either during culture-induced activation or after exogenous HB-EGF (100 ng/ml) treatment. TAA induced liver fibrosis in both HB-EGF(+/+) and HB-EGF(-/-) mice. Hepatic HB-EGF expression was decreased in TAA-treated HB-EGF(+/+) mice by 37.6% (P<0.05) as compared with animals receiving saline alone. HB-EGF(-/-) mice treated with TAA showed increased hepatic α-smooth muscle actin-positive cells and collagen deposition, and, as compared with HB-EGF(+/+) mice, TAA-stimulated hepatic mRNA levels in HB-EGF(-/-) mice were, respectively, 2.1-, 1.7-, 1.8-, 2.2-, 1.2- or 3.3-fold greater for α-smooth muscle actin, α1 chain of collagen I or III (COL1A1 or COL3A1), transforming growth factor-β1, connective tissue growth factor or tissue inhibitor of metalloproteinase-1 (P<0.05). HB-EGF expression was detectable in primary cultured HSCs from HB-EGF(+/+) mice. Both endogenous and exogenous HB-EGF inhibited HSC activation in primary culture, and HB-EGF enhanced HSC migration. These findings suggest that HB-EGF gene knockout in mice increases susceptibility to chronic TAA-induced hepatic fibrosis and that HB-EGF expression or action is associated with suppression of fibrogenic pathways in HSCs.     

BMP-7 attenuates liver fibrosis via regulation of epidermal growth factor receptor

The aim of this study was to elucidate the effect of bone morphogenetic protein-7 (BMP-7) on liver fibrosis induced by carbon tetrachloride (CCl4) in vivo and on the hepatic stellate cells (HSC) activation in vitro. In vivo, thirty male ICR mice were randomly allocated to three groups, the control group (n = 6), the CCl4 group (n = 18) and the BMP-7+CCl4 group (n = 6). The model of liver fibrosis was induced by intraperitoneal injection with CCl4 three times per week lasting for 12 weeks in CCl4 group and the BMP-7+CCl4 group. After 8 weeks injection with CCl4, mice were intraperitoneal injected with human recombinant BMP-7 in BMP-7+CCl4 group. Meanwhile, mice in the CCl4 group were only intraperitoneal injection with equal amount of saline. The degree of liver fibrosis was assessed by HE and Masson’s staining. PCR and western blot were used to detect mRNA and protein levels. In BMP-7+CCl4 group, serum levels of alanine aminotransferase (ALT) and aminotransferase (AST) were decreased and serum albumin (Alb) was increased. Meanwhile, the expressions of transforming growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) were down-regulated by BMP-7 intervention as compared to the CCl4 group (P < 0.05). Furthermore, BMP-7 also suppressed the expression of epidermal growth factor receptor (EGFR) and phosphorylated-epidermal growth factor receptor (pEGFR). HE and Masson stain showed that liver damage was alleviated in BMP-7+CCl4 group. In vitro study, expression of EGFR, TGF-β1 and α-SMA were down regulated by BMP-7 dose-dependently, indicating it might effect on suppression of HSC activation. Therefore, our data indicate BMP-7 was capable of inhibiting liver fibrosis and suppressing HSCs activation, and these effects might rely on its crosstalk with EGFR and TGF-β1. We suggest that BMP-7 may be a potential reagentfor the prevention and treatment of liver fibrosis.     

Astragaloside effect on TGF-β1, SMAD2/3, and α-SMA expression in the kidney tissues of diabetic KKAy mice

Numerous cytokines participate in the occurrence and development of inflammation and renal interstitial fibrosis. Previous studies confirmed that TGF-β1 overexpressed in diabetic nephropathy. As a downstream signal protein of TGF-β1 family, SMAD has an important role in the process of α-SMA mediated renal interstitial fibrosis. This study aimed to study astragaloside effect on TGF-β1, SMAD2/3, and α-SMA expression in the kidney tissue of diabetic KKAy mice, to reveal its potential impact on renal interstitial fibrosis. 20 type II diabetic KKAy mice were randomly equally divided into model group and astragaloside group, while 10 male C57BL/6J mice were selected as the control. Astragaloside at 40 mg/(kg•d) was given when the KKAy mice fed with high-fat diet to 14 weeks old. The mice were killed at 24 weeks old and the kidney tissue samples were collected. Pathology morphological changes were observed. TGF-β1, SMAD2/3, and α-SMA expression levels were determined by immunohistochemistry. Compared with control, mice kidney in model group appeared obvious fibrosis and up-regulated blood glucose level, TGF-β1, SMAD2/3, and α-SMA expression (P < 0.05). Mice in astragaloside group exhibited alleviated renal interstitial fibrosis compared with the model. Its blood glucose level, TGF-β1, SMAD2/3, and α-SMA expression levels were significantly lower than the model group (P < 0.05). Astragaloside can delay the renal fibrosis process in diabetic mice by influencing the TGF-β/SMADS signaling pathway and down-regulating TGF-β1, SMAD2/3, and α-SMA expression.     

Characterization of glial fibrillary acidic protein (GFAP)-expressing hepatic stellate cells and myofibroblasts in thioacetamide (TAA)-induced rat liver injury

Hepatic stellate cells (HSCs), which can express glial fibrillary acidic protein (GFAP) in normal rat livers, play important roles in hepatic fibrogenesis through the conversion into myofibroblasts (MFs). Cellular properties and possible derivation of GFAP-expressing MFs were investigated in thioacetamide (TAA)-induced rat liver injury and subsequent fibrosis. Seven-week-old male F344 rats were injected with TAA (300 mg/kg BW, once, intraperitoneally), and were examined on post single injection (PSI) days 1–10 by the single and double immunolabeling with MF and stem cell marker antibodies. After hepatocyte injury in the perivenular areas on PSI days 1 and 2, the fibrotic lesion consisting of MF developed at a peak on PSI day 3, and then recovered gradually by PSI day 10. MFs expressed GFAP, and also showed co-expressions such cytoskeletons (MF markers) as vimentin, desmin and α-SMA in varying degrees. Besides MFs co-expressing vimentin/desmin, desmin/α-SMA or α-SMA/vimentin, some GFAP positive MFs co-expressed with nestin or A3 (both, stem cell markers), and there were also MFs co-expressing nestin/A3. However, there were no GFAP positive MFs co-expressing RECA-1 (endothelial marker) or Thy-1 (immature mesenchymal cell marker). GFAP positive MFs showed the proliferating activity, but they did not undergo apoptosis. However, α-SMA positive MFs underwent apoptosis. These findings indicate that HSCs can proliferate and then convert into MFs with co-expressing various cytoskeletons for MF markers, and that the converted MFs may be derived partly from the stem cell lineage. Additionally, well-differentiated MFs expressing α-SMA may disappear by apoptosis for healing. These findings shed some light on the pathogenesis of chemically induced hepatic fibrosis.     

Involvement of MCP-1 in Tubulointerstitial Fibrosis Through Massive Proteinuria in Anti-GBM Nephritis Induced in WKY Rats

We investigated participation of monocyte chemoattractant protein-1 (MCP-1) in tubulointerstitial fibrosis and correlation between MCP-1 and proteinuria in Wistar-Kyoto (WKY) rats with glomerulonephritis induced by anti-glomerular basement membrane (anti-GBM) antibody. WKY rats showed marked proteinuria and severe glomerular crescent formation at 7 days post antibody injection. At 28 days, tubulointerstitial fibrotic lesions were observed, followed by sustained heavy proteinuria and severe tubulointerstitial fibrosis at 56 days. Histological examination revealed that the overlapped immunoreactivities of MCP-1, rat albumin, and p65NF-κB were detected in the same tubular segments of nephritic kidney, and a significant positive correlation was observed between proteinuria and MCP-1 expression in the tubulointerstitial fibrosis. ED-1- and CD8-positive cells were also abundant, and there was a good correlation between monocyte/macrophage recruitment and MCP-1 expression in the tubulointerstitial area. These results suggest that MCP-1 participates in the progression of tubulointerstitial fibrosis, through massive albuminuria, which is accompanied by marked monocyte/macrophage recruitment.     

Inhibitory effects of dimethyl α-ketoglutarate in hepatic stellate cell activation

Aim: The activation of Hepatic stellate cell (HSC) is a pivotal event in the initiation and progression of hepatic fibrosis and a major source of collagen deposition. A recent study found that autophagy fuels the HSC activation. α-ketoglutarate (AKG), an intermediate in the Kerbs CYCLE, has been shown to regulate the level of autophagy. In this study, we aim to investigate the potential effect of dimethyl α-ketoglutarate (DMKG), a membrane-permeable esters of AKG, on the activation of HSC. Methods: HSC and hepatocyte cell lines were treated with DMKG at gradient concentrations, MTT assay was used to assess the cell viability. Concentrations of DMKG that did not affect the cell survival were added to the culture media of HSC cells. Real-time PCR and western blot analysis was carried out to evaluate the expression of fibrogenic genes in HSC after culture for 24 hours. Results: Low dose of DMKG had little cytotoxicity to both HSCs and hepatocytes, while HSCs were more vulnerable to high dose of DMKG than hepatocytes. More importantly, DMKG inhibited the expression of α-SMA and collagen I significantly in HSCs detected by real-time PCR and western blot analysis at the concentrations that didn’t decrease cell viability. Conclusions: DMKG has a significant role of inhibiting the activation of HSC and may attenuate hepatic fibrosis safely.     

Growth inhibition and apoptosis in liver myofibroblasts promoted by hepatocyte growth factor leads to resolution from liver cirrhosis

Liver cirrhosis is characterized by hepatic dysfunction with extensive accumulation of fibrous tissue in the liver. In response to chronic hepatic injury, hepatic portal myofibroblasts and activated hepatic stellate cells (HSCs) play a role in liver fibrosis. Although administration or gene expression of hepatocyte growth factor (HGF) leads to improvement in hepatic fibrosis/cirrhosis, the related mechanisms are not fully understood. We investigated mechanisms involved in resolution from liver cirrhosis by HGF, focusing on growth regulation and apoptosis in portal myofibroblasts. Cultured rat HSCs could not proliferate, were withdrawn after passage, and were replaced by proliferating portal myofibroblasts during the passages. In quiescent HSCs, c-Met receptor expression was undetected whereas c-Met receptor expression was detected in activated HSCs and liver myofibroblasts expressing alpha-smooth muscle actin (alpha-SMA), suggesting that activated HSCs and portal myofibroblasts are targets of HGF. For cultured rat portal myofibroblasts, HGF counteracted phosphorylation of extracellular signal-regulated kinase (Erk) 1/2 and mitogenic stimulus induced by platelet-derived growth factor, induced c-jun N-terminal kinase (JNK) 1 phosphorylation, and promoted apoptotic cell death. In the dimethylnitrosamine rat model of liver cirrhosis, administration of HGF suppressed proliferation while promoting apoptosis of alpha-SMA-positive cells in the liver, events that were associated with reduced hepatic expressions of alpha-SMA and histological resolution from liver cirrhosis. Growth inhibition and enhanced apoptosis in portal myofibroblasts by HGF are newly identified mechanisms aiding resolution from liver fibrosis/cirrhosis by HGF.     

肝纤维化病理过程中ZEB1和ZEB2的动态表达变化及意义

目的:观察慢性肝损伤致肝纤维化过程中上皮-间质转化(EMT)调节蛋白锌指E盒结合同源盒蛋白(ZEB)1和ZEB2的动态表达变化并探讨其调节机制。方法:雄性Wistar大鼠40只,随机分为正常对照组、2周、4周、6周和8周模型组,每组各8只,模型组按3 mL/kg体重的剂量皮下注射60%CCl₄,每隔3 d注射1次,处死大鼠后测定肝脏指数、血清丙氨酸氨基转移酶(ALT)和天冬氨酸氨基转移酶(AST)活性,观察肝组织病理改变;免疫组织化学法检测肝组织中ZEB1、ZEB2、E-钙黏蛋白(E-cadherin)和α-平滑肌肌动蛋白(α-SMA)的表达情况;real-time RT-PCR方法检测肝脏组织中ZEB1及ZEB2 mRNA的表达变化。结果:模型各组大鼠肝脏指数、血清ALT和AST活性显著高于正常对照组(P＜0.01),8周模型组肝纤维化明显;随着肝脏损伤逐渐加重,纤维化程度加深,E-cadherin蛋白的表达显著降低,α-SMA蛋白表达显著升高,ZEB1和ZEB2蛋白和mRNA表达量也逐渐增加,8周模型组肝组织中ZEB1和ZEB2蛋白(46.42±14.36和57.71±13.32)与mRNA(189.00±47.39和277.28±48.55)表达较正常组显著增加(P＜0.01)。结论:ZEB1和ZEB2蛋白及mRNA表达量随纤维化程度的加重而增加,提示EMT可能通过ZEB1和ZEB2参与肝纤维化的发生发展。     

骨髓间质干细胞抑制肝星状细胞增殖与活化的体外研究

目的：探讨骨髓间质干细胞（MSCs）对活化态肝星状细胞（HSCs）增殖的影响。 方法： 分别从骨髓和肝脏分离纯化培养大鼠MSCs及HSCs，塑料板传代培养激活HSCs；在半透膜（transwell insert）上接种MSCs，在6孔塑料培养板上接种HSCs，建立上下双层细胞共培养体系；大鼠正常肝细胞系（BRLs）及HSCs培养分别作为对照。免疫细胞化学检测平滑肌激动蛋白（α-SMA）与结蛋白的表达，IBAS 2.5软件分析阳性染色表达量。 结果： HSCs与MSCs共培养24 h，HSCs表现轻度增殖抑制，随着培养时间延长，HSCs增殖活性受抑制更明显，在48 h和72 h的抑制率分别达15.7%与30.3%，与BRLs共培养体系比较有显著差异；与MSCs共培养72 h, HSCs表达α-SMA量明显低于两个对照组BRLs及HSCs培养体系（50.2% vs 90.2%、95.6%, P＜0.01）；而结蛋白表达的量在3组共培养体系中均无显著差异。 结论： MSCs具有分泌细胞因子抑制HSCs增殖活性的潜能,在治疗肝纤维化中可能发挥作用。     

A Case of Liver Fibrosis with Splenomegaly after Oxaliplatin-Based Adjuvant Chemotherapy for Colon Cancer

Previous studies reported that oxaliplatin is associated with sinusoidal obstruction syndrome. However few reports on oxaliplatin induced liver fibrosis are found in the literature. Furthermore pathogenesis of liver fibrosis is not well known. We report a case of 45-yr-old Korean man in whom liver fibrosis with splenomegaly developed after 12 cycles of oxaliplatin based adjuvant chemotherapy for colon cancer (T4N2M0). Thorough history taking and serological examination revealed no evidence of chronic liver disease. Restaging CT scans demonstrated a good response to chemotherapy. Five month after chemotherapy, he underwent right hepatectomy due to isolated metastatic lesion. The liver parenchyma showed diffuse sinusoidal dilatation and centrilobular vein fibrosis with necrosis without steatosis. We could conclude that splenomegaly was due to perisinusoidal liver fibrosis and liver cell necrosis induced portal hypertension by oxaliplatin. In addition, to investigate the pathogenesis of liver fibrosis, immunohistochemical stains such as CD31 and α-smooth muscle actin (α-SMA) were conducted with control group. The immunohistochemical stains for CD31 and α-SMA were positive along the sinusoidal space in the patient, while negative in the control group. Chemotherapy with oxaliplatin induces liver fibrosis which should be kept in mind as a serious complication.