AIM:To investigate anti-apoptotic effects of glycyrrhizic acid(GA) against fibrosis in carbon tetrachloride(CCl4)-induced liver injury and its contributing factors.METHODS:Liver fibrosis was induced by administration ...AIM:To investigate anti-apoptotic effects of glycyrrhizic acid(GA) against fibrosis in carbon tetrachloride(CCl4)-induced liver injury and its contributing factors.METHODS:Liver fibrosis was induced by administration of CCl4 for 8 wk.Pathological changes in the liver of rats were examined by hematoxylin-eosin staining.Collagen fibers were detected by Sirius red staining.Hepatocyte apoptosis was determined by TUNEL assay and the expression levels of cleaved caspase-3,Bax,α-SMA,connective tissue growth factor(CTGF),matrix metalloproteinase(MMP) 2 and MMP9 proteins were evaluated by western blot analysis,and α-SMA m RNA,collagen type Ⅰ and Ⅲ m RNA were estimated by real-time PCR.RESULTS:Treatment with GA significantly improved the pathological changes in the liver and markedly decreased the positive area of Sirius red compared with rats in the CCl4-treated group.TUNEL assay showed that GA significantly reduced the number of TUNEL-positive cells compared with the CCl4-treated group.The expression levels of cleaved caspase-3,Bax,α-SMA,CTGF,MMP2 and MMP9 proteins,and α-SMA m RNA,collagen type Ⅰ and Ⅲ m RNA were also significantly reduced by GA compared with the CCl4-treated group(P < 0.05).CONCLUSION:GA treatment can ameliorate CCl4-induced liver fibrosis by inhibiting hepatocyte apoptosis and hepatic stellate cell activation.展开更多
AIM:To investigate the effect of interferon-a (IFN-α) on preventing or reversing hepatic fibrosis in rat experimental model induced by CCI4. METHODS: One hundred and ten Sprague-Dawley rats were divided into five gro...AIM:To investigate the effect of interferon-a (IFN-α) on preventing or reversing hepatic fibrosis in rat experimental model induced by CCI4. METHODS: One hundred and ten Sprague-Dawley rats were divided into five groups: group A (normal controls, n = 18), group B (fibrotic model controls, n = 22), group C (IFN-α prevention, n = 22) initially treated with intramuscular injection of IFN-a in saline daily at the doses of 1× 105 U for 6 wk, group D (IFN-a treatment, n = 24) treated with intra-muscular injection of IFN-a in saline daily at the doses of 1×105 U for 6 wk after the first 6 wk, group E (0.9% sodium chloride treatment control, n = 24) treated with intra-muscular injection of 0.01 mL/kg daily for 6 wk after the first 6 wk. At the end of the experiment, all rats of each group were killed. Samples of the liver obtained by biopsy were subjected to histological, immunohistochemical and electron microscopic studies for the expressions of transforming growth factor-pi (TGF- μ41) and α-smooth muscle actin (α-SMA). RESULTS: The expressions of TGF-pl, the number of activated hepatic stellate cells and a-SMA in hepatic tissue of group C were significantly less than those of group B (P<0.01). The degree of fibrosis score in group B was also significantly less than that of group C under light microscope (P<0.01). CONCLUSION: IFN-a can inhibit the production of TGF-pl, decrease HSC activation and stimulate its apoptosis.展开更多
AIM： To investigate the potential mechanism of Arg- Gly-Asp （RGD） peptide-labeled liposome loading oxy- matrine （OM） therapy in CCI4-induced hepatic fibrosis in rats. METHODS： We constructed a rat model of CCh- ...AIM： To investigate the potential mechanism of Arg- Gly-Asp （RGD） peptide-labeled liposome loading oxy- matrine （OM） therapy in CCI4-induced hepatic fibrosis in rats. METHODS： We constructed a rat model of CCh- induced hepatic fibrosis and treated the rats with dif- ferent formulations of OM. To evaluate the antifibrotic effect of OM, we detected levels of alkaline phospha- tase, hepatic histopathology （hematoxylin and eosin stain and Masson staining） and fibrosis-related gene expression of matrix metallopeptidase （MMP）-2, tis- sue inhibitor of metalloproteinase （TIMP）-I as well as type I procollagen via quantitative real-time poly- merase chain reaction. To detect cell viability and apop- tosis of hepatic stellate cells （HSCs）, we performed 3-（4,5）-dimethylthiahiazo（-z-yl）-3,5-diphenytetrazoli- umromide assay and flow cytometry. To reinforce the combination of oxymatrine with HSCs, we constructed fluorescein-isothiocyanate-conjugated Arg-Gly-Asp peptide-labeled liposomes loading OM, and its targeting of HSCs was examined by fluorescent microscopy. RESULTS： OM attenuated CCh-induced hepatic fibro- sis, as defined by reducing serum alkaline phosphatase （344.47± 27.52 U/L vs 550.69 ± 43.78 U/L, P 〈 0.05）, attenuating liver injury and improving collagen deposits （2.36% ± 0.09% vs 7.70% ±0.60%, P 〈 0.05） and downregulating fibrosis-related gene expression, that is, MMP-2, TIMP-1 and type I procollagen （P 〈 0.05）. OM inhibited cell viability and induced apoptosis of HSCs in vitro. RGD promoted OM targeting of HSCs and en- hanced the therapeutic effect of OM in terms of serum alkaline phosphatase （272.51 ± 19.55 U/L vs 344.47 ± 27.52 U/L, P 〈 0.05）, liver injury, collagen deposits （0.26%± 0.09% vs 2.36% ± 0.09%, P 〈 0.05） and downregulating fibrosis-related gene expression, that is, MMP-2, TIMP-1 and type I procollagen （P 〈 0.05）. Moreover, in vitro assay demonstrated that RGD en- hanced the effect of OM on HSC viability and apoptosis. CO展开更多
AIM To study the molecular mechanisms ofretinoic acid(RA)on proliferation andexpression of cyclin-dependent kinase inhibitors(CKI),i.e.p16,p21 and p27 in cultured rathepatic stellate cells(HSC)stimulated withtransform...AIM To study the molecular mechanisms ofretinoic acid(RA)on proliferation andexpression of cyclin-dependent kinase inhibitors(CKI),i.e.p16,p21 and p27 in cultured rathepatic stellate cells(HSC)stimulated withtransforming growth factor beta 1(TGF-β1).METHODS HSC were isolated from healthy ratlivers and cultured.After stimulated with1 mg/L TGF-β1,subcultured HSC were treatedwith or without 1 nmol/L RA.MTT assay,immunocytochemistry(ICC)for p16,p21,p27and α-smooth muscle actin(α-SMA)protein,insitu hybridization(ISH)for retinoic acidreceptor beta 2(RAR-β2)and p16,p21 and p27mRNA and quantitative image analysis(partially)were performed.RESULTS RA inhibited HSC proliferation(41.50%,P【0.05),decreased the protein levelof α-SMA(55.09%,P【0.05),and induced HSCto express RAR-β2 mRNA.In addition,RAincreased the protein level of p16(218.75%,P【0.05)and induced p21 protein expression;meanwhile,p27 was undetectable by ICC in bothcontrol and RA-treated HSC.However,RA hadno influence on the mRNA levels of p16,p21 orp27 as determined by ISH.CONCLISION Up-regulation of p16 and p21 on post-transcriptional level may contribule, in part to RA inhibition of TGF-β1-initiated rat HSC activation in vitro.展开更多
AIM: To identify signaling pathways and genes that initiate and commit hepatic stellate cells (HSCs) to transdifferentiation. METHODS: Primary HSCs were isolated from male Sprague-Dawley rats and cultured on plastic f...AIM: To identify signaling pathways and genes that initiate and commit hepatic stellate cells (HSCs) to transdifferentiation. METHODS: Primary HSCs were isolated from male Sprague-Dawley rats and cultured on plastic for 0-10 d. Gene expression was assessed daily (quiescent to day 10 culture-activation) by real time polymerase chain reaction and data clustered using AMADA software. The significance of JAK/STAT signaling to HSC transdifferentiation was determined by treating cells with a JAK2 inhibitor. RESULTS: Genetic cluster analyses, based on expression of these 21 genes, showed similar expression profiles on days 1-3, days 5 and 6, and days 7-10, while freshly isolated cells (day Q) and day 4 cells were genotypically distinct from any of the other days. Additionally, gene expression clustering revealed strong upregulation of interleukin-6, JAK2 and STAT3 mRNA in the early stages of activation. Inhibition of the JAK/STAT signaling pathway impeded the morphological transdifferentiation of HSCs which correlated with decreased mRNA expression of several profibrotic genes including collagens, α-SMA, PDGFR and TGFβR. CONCLUSION: These data demonstrate unique clustered genetic profiles during the daily progression of HSC transdifferentiation and that JAK/STAT signaling may be critical in the early stages of transdifferentiation.展开更多
Background Hepatitis B is at particularly high risk of fibrosis progression. Unfortunately, the mechanism of hepatic fibrogenesis induced by hepatitis B virus （HBV） has not been fully understood to date. The aim of ...Background Hepatitis B is at particularly high risk of fibrosis progression. Unfortunately, the mechanism of hepatic fibrogenesis induced by hepatitis B virus （HBV） has not been fully understood to date. The aim of this study was to observe whether HBV can infect hepatic stellate cells （HSCs）, and to examine the effects of HBV or HBV S protein （HBs） on the proliferation and collagen type I expression of HSCs. Methods The supernatants of HepG2.2.15 cells which contained HBV-DNA or HBs were added to LX-2 cells for 72 hours. Cell survival was determined by MTT assay. HBV particles in LX-2 cells were detected by transmission electron microscopy. The expression of HBs and HBV C protein （HBc） was determined by confocal fluorescence microscopy. The expression levels of HBV-DNA were measured by real-time PCR. The cellular collagen type I mRNA and protein levels were quantified by reverse transcription-PCR and ELISA, respectively. Results High concentrations of HBV （1.2×10^5-5.0×10^5 copies/ml） or HBs （1.25-20 μg/ml） inhibited the proliferation of LX-2 cells, while low concentrations of HBV （1.0×10^3-6.2×10^4 copies/ml） or HBs （0.04-0.62 μg/ml） promoted the proliferation. After treating LX-2 cells with HBV for 72 hours, about 42 nm HBV-sized particles and strong expression of HBs and HBc were found in the cytoplasm of LX-2 cells. HBV-DNA in the culture medium of LX-2 cells decreased at 24 hours, rose at 48 hours and thereafter, decreased again at 72 hours. The mRNA and protein expression of cellular collagen type I in LX-2 ceils were significantly increased by HBV infection but not by recombinant HBs. Conclusions HBV and HBs affect the proliferation of HSCs; HBV can transiently infect and replicate in cultured HSCs and express HBs and HBc in vitro. Furthermore, HBV can significantly increase the expression of collagen type I mRNA and protein in HSCs.展开更多
Liver fibrosis is a wound-healing response to chronic injuries, characterized by the excessive accumulation of extracellular matrix or scar tissue within the liver;in addition, its formation is associated with multipl...Liver fibrosis is a wound-healing response to chronic injuries, characterized by the excessive accumulation of extracellular matrix or scar tissue within the liver;in addition, its formation is associated with multiple cytokines as well as several cell types and a variety of signaling pathways. When liver fibrosis is not well controlled, it can progress to liver cirrhosis, but it is reversible in principle. Thus far, no efficient therapy is available for treatment of liver fibrosis. Although liver transplantation is the preferred strategy, there are many challenges remaining in this approach, such as shortage of donor organs, immunological rejection, and surgical complications. Hence, there is a great need for an alternative therapeutic strategy. Currently, mesenchymal stem cell (MSC) therapy is considered a promising therapeutic strategy for the treatment of liver fibrosis;advantageously, the characteristics of MSCs are continuous self-renewal, proliferation, multipotent differentiation, and immunomodulatory activities. The human umbilical cord-derived (hUC)-MSCs possess not only the common attributes of MSCs but also more stable biological characteristics, relatively easy accessibility, abundant source, and no ethical issues (e.g., bone marrow being the adult source), making hUC-MSCs a good choice for treatment of liver fibrosis. In this review, we summarize the biological characteristics of hUC-MSCs and their paracrine effects, exerted by secretion of various cytokines, which ultimately promote liver repair through several signaling pathways. Additionally, we discuss the capacity of hUC-MSCs to differentiate into hepatocyte-like cells for compensating the function of existing hepatocytes, which may aid in amelioration of liver fibrosis. Finally, we discuss the current status of the research field and its future prospects.展开更多
AIM: Silymarin is a potent antioxidant, antiinflammatory and anti-fibrogenic agent in the liver, which is mediated by alteration of hepatic Kupffer cell function, lipid peroxidation, and collagen production. Especiall...AIM: Silymarin is a potent antioxidant, antiinflammatory and anti-fibrogenic agent in the liver, which is mediated by alteration of hepatic Kupffer cell function, lipid peroxidation, and collagen production. Especially, in hepatic fibrogenesis, mast cells are expressed in chronic inflammatory conditions, and promote fibroblast growth and stimulate production of the extracellular matrix by hepatic stellate cells. METHODS: We examined the inhibitory mechanism of silymarin on CCI4-induced hepatic cirrhosis in rats. At 4, 8, and 12 wk, liver tissues were examined histopathologically for fibrotic changes produced by silymarin treatment. RESULTS: In the silymarin with CCU-treated group, increase of hepatic stellate cells and TGF-β1 production were lower than in the CCI4-treated group at early stages. Additionally, at the late fibrogenic stage, expressions of TGF-β1 were weaker and especially not expressed in hepatocytes located in peripheral areas. Moreover, the number of mast cell in portal areas gradually increased and was dependent on the fibrogenic stage, but those of CCI4+silymarin-treated group decreased significantly. CONCLUSION: Anti-fibrotic and antiinflammatory effects of silymarin were associated with activation of hepatic stellate cells through the expression of TGF-β1 and stabilization of mast cells. These results suggest that silymarin prevent hepatic fibrosis through suppression of inflammation and hypoxia in the hepatic fibrogenesis.展开更多
Liver fibrosis is the common pathological basis of all chronic liver diseases,and is the necessary stage for the progression of chronic liver disease to cirrhosis.As one of pathogenic factors,inflammation plays a pred...Liver fibrosis is the common pathological basis of all chronic liver diseases,and is the necessary stage for the progression of chronic liver disease to cirrhosis.As one of pathogenic factors,inflammation plays a predominant role in liver fibrosis via communication and interaction between inflammatory cells,cytokines,and the related signaling pathways.Damaged hepatocytes induce an increase in proinflammatory factors,thereby inducing the development of inflammation.In addition,it has been reported that inflammatory response related signaling pathway is the main signal transduction pathway for the development of liver fibrosis.The crosstalk regulatory network leads to hepatic stellate cell activation and proinflammatory cytokine production,which in turn initiate the fibrotic response.Compared with the past,the research on the pathogenesis of liver fibrosis has been greatly developed.However,the liver fibrosis mechanism is complex and many pathways involved need to be further studied.This review mainly focuses on the crosstalk regulatory network among inflammatory cells,cytokines,and the related signaling pathways in the pathogenesis of chronic inflammatory liver diseases.Moreover,we also summarize the recent studies on the mechanisms underlying liver fibrosis and clinical efforts on the targeted therapies against the fibrotic response.展开更多
Objective: To investigate the effect of Fuzhenghuayu decoction on autocrine activation of hepatic stellate cell (HSC). Methods: The drug serum containing Fuzhenghuayu decoction was collected from normal rats, and cul-...Objective: To investigate the effect of Fuzhenghuayu decoction on autocrine activation of hepatic stellate cell (HSC). Methods: The drug serum containing Fuzhenghuayu decoction was collected from normal rats, and cul- tured with activated HSC in vitro. The conditioned medium from the drug serum treated HSC was added to primary cultured quiescent HSC. Cell prolifera- tion was assayed by tetrazolium colorimetric test, and the contents of type Ⅰ collagen and vascular endo- thelial growth factor (VEGF) in the supernatant were measured with ELISA. Results: The conditioned medium from activated HSC could stimulate the quiescent HSC proliferation and type Ⅰ collagen secretion. The drug serum inhibi- ted this stimulating action and VEGF secretion from the activated HSC. Conclusion: Fuzhenghuayu decoction acts effectively against the autocrine activation pathway of HSC. The mechanism may be associated with the inhibition of the secretion of VEGF by activated HSC.展开更多
Constant alcohol consumption is a major cause of chronic liver disease, and there has been a growing concern regarding the increased mortality rates worldwide. Alcoholic liver diseases (ALDs) range from mild to more s...Constant alcohol consumption is a major cause of chronic liver disease, and there has been a growing concern regarding the increased mortality rates worldwide. Alcoholic liver diseases (ALDs) range from mild to more severe conditions, such as steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. The liver is enriched with innate immune cells (e.g. natural killer cells and Kupffer cells) and hepatic stellate cells (HSCs), and interestingly, emerging evidence suggests that innate immunity contributes to the development of ALDs (e.g. steatohepatitis and liver fibrosis). Indeed, HSCs play a crucial role in alcoholic steatosis via production of endocannabinoid and retinol metabolites. This review describes the roles of the innate immunity and HSCs in the pathogenesis of ALDs, and suggests therapeutic targets and strategies to assist in the reduction of ALD.展开更多
Obeticholic acid(OCA), the first FXR-targeting drug, has been claimed effective in the therapy of liver fibrosis. However, recent clinical trials indicated that OCA might not be effective against liver fibrosis, possi...Obeticholic acid(OCA), the first FXR-targeting drug, has been claimed effective in the therapy of liver fibrosis. However, recent clinical trials indicated that OCA might not be effective against liver fibrosis, possibly due to the lower dosage to reduce the incidence of the side-effect of pruritus. Here we propose a combinatory therapeutic strategy of OCA and apoptosis inhibitor for combating against liver fibrosis. CCl4-injured mice, D-galactosamine/LPS(GalN/LPS)-treated mice and cycloheximide/TNFα(CHX/TNFα)-treated HepG2 cells were employed to assess the effects of OCA, or together with IDN-6556, an apoptosis inhibitor. OCA treatment significantly inhibited hepatic stellate cell(HSC)activation/proliferation and prevented fibrosis. Elevated bile acid(BA) levels and hepatocyte apoptosis triggered the activation and proliferation of HSCs. OCA treatment reduced BA levels but could not inhibit hepatocellular apoptosis. An enhanced anti-fibrotic effect was observed when OCA was co-administrated with IDN-6556. Our study demonstrated that OCA inhibits HSCs activation/proliferation partially by regulating BA homeostasis and thereby inhibiting activation of HSCs. The findings in this study suggest that combined use of apoptosis inhibitor and OCA at lower dosage represents a novel therapeutic strategy for liver fibrosis.展开更多
基金Medical and Health Science and Technology Planning Project of Zhejiang Province in 2012,China,Grant NO.2012RCB007
文摘AIM:To investigate anti-apoptotic effects of glycyrrhizic acid(GA) against fibrosis in carbon tetrachloride(CCl4)-induced liver injury and its contributing factors.METHODS:Liver fibrosis was induced by administration of CCl4 for 8 wk.Pathological changes in the liver of rats were examined by hematoxylin-eosin staining.Collagen fibers were detected by Sirius red staining.Hepatocyte apoptosis was determined by TUNEL assay and the expression levels of cleaved caspase-3,Bax,α-SMA,connective tissue growth factor(CTGF),matrix metalloproteinase(MMP) 2 and MMP9 proteins were evaluated by western blot analysis,and α-SMA m RNA,collagen type Ⅰ and Ⅲ m RNA were estimated by real-time PCR.RESULTS:Treatment with GA significantly improved the pathological changes in the liver and markedly decreased the positive area of Sirius red compared with rats in the CCl4-treated group.TUNEL assay showed that GA significantly reduced the number of TUNEL-positive cells compared with the CCl4-treated group.The expression levels of cleaved caspase-3,Bax,α-SMA,CTGF,MMP2 and MMP9 proteins,and α-SMA m RNA,collagen type Ⅰ and Ⅲ m RNA were also significantly reduced by GA compared with the CCl4-treated group(P < 0.05).CONCLUSION:GA treatment can ameliorate CCl4-induced liver fibrosis by inhibiting hepatocyte apoptosis and hepatic stellate cell activation.
文摘AIM:To investigate the effect of interferon-a (IFN-α) on preventing or reversing hepatic fibrosis in rat experimental model induced by CCI4. METHODS: One hundred and ten Sprague-Dawley rats were divided into five groups: group A (normal controls, n = 18), group B (fibrotic model controls, n = 22), group C (IFN-α prevention, n = 22) initially treated with intramuscular injection of IFN-a in saline daily at the doses of 1× 105 U for 6 wk, group D (IFN-a treatment, n = 24) treated with intra-muscular injection of IFN-a in saline daily at the doses of 1×105 U for 6 wk after the first 6 wk, group E (0.9% sodium chloride treatment control, n = 24) treated with intra-muscular injection of 0.01 mL/kg daily for 6 wk after the first 6 wk. At the end of the experiment, all rats of each group were killed. Samples of the liver obtained by biopsy were subjected to histological, immunohistochemical and electron microscopic studies for the expressions of transforming growth factor-pi (TGF- μ41) and α-smooth muscle actin (α-SMA). RESULTS: The expressions of TGF-pl, the number of activated hepatic stellate cells and a-SMA in hepatic tissue of group C were significantly less than those of group B (P<0.01). The degree of fibrosis score in group B was also significantly less than that of group C under light microscope (P<0.01). CONCLUSION: IFN-a can inhibit the production of TGF-pl, decrease HSC activation and stimulate its apoptosis.
基金Supported by National Natural Science Foundation of China,No. 30600848
文摘AIM： To investigate the potential mechanism of Arg- Gly-Asp （RGD） peptide-labeled liposome loading oxy- matrine （OM） therapy in CCI4-induced hepatic fibrosis in rats. METHODS： We constructed a rat model of CCh- induced hepatic fibrosis and treated the rats with dif- ferent formulations of OM. To evaluate the antifibrotic effect of OM, we detected levels of alkaline phospha- tase, hepatic histopathology （hematoxylin and eosin stain and Masson staining） and fibrosis-related gene expression of matrix metallopeptidase （MMP）-2, tis- sue inhibitor of metalloproteinase （TIMP）-I as well as type I procollagen via quantitative real-time poly- merase chain reaction. To detect cell viability and apop- tosis of hepatic stellate cells （HSCs）, we performed 3-（4,5）-dimethylthiahiazo（-z-yl）-3,5-diphenytetrazoli- umromide assay and flow cytometry. To reinforce the combination of oxymatrine with HSCs, we constructed fluorescein-isothiocyanate-conjugated Arg-Gly-Asp peptide-labeled liposomes loading OM, and its targeting of HSCs was examined by fluorescent microscopy. RESULTS： OM attenuated CCh-induced hepatic fibro- sis, as defined by reducing serum alkaline phosphatase （344.47± 27.52 U/L vs 550.69 ± 43.78 U/L, P 〈 0.05）, attenuating liver injury and improving collagen deposits （2.36% ± 0.09% vs 7.70% ±0.60%, P 〈 0.05） and downregulating fibrosis-related gene expression, that is, MMP-2, TIMP-1 and type I procollagen （P 〈 0.05）. OM inhibited cell viability and induced apoptosis of HSCs in vitro. RGD promoted OM targeting of HSCs and en- hanced the therapeutic effect of OM in terms of serum alkaline phosphatase （272.51 ± 19.55 U/L vs 344.47 ± 27.52 U/L, P 〈 0.05）, liver injury, collagen deposits （0.26%± 0.09% vs 2.36% ± 0.09%, P 〈 0.05） and downregulating fibrosis-related gene expression, that is, MMP-2, TIMP-1 and type I procollagen （P 〈 0.05）. Moreover, in vitro assay demonstrated that RGD en- hanced the effect of OM on HSC viability and apoptosis. CO
基金the National Natural Science Foundation of China,No.39670287the Scientific Research Foundation for Doctorate Education,State Education Commission.No.96026530
文摘AIM To study the molecular mechanisms ofretinoic acid(RA)on proliferation andexpression of cyclin-dependent kinase inhibitors(CKI),i.e.p16,p21 and p27 in cultured rathepatic stellate cells(HSC)stimulated withtransforming growth factor beta 1(TGF-β1).METHODS HSC were isolated from healthy ratlivers and cultured.After stimulated with1 mg/L TGF-β1,subcultured HSC were treatedwith or without 1 nmol/L RA.MTT assay,immunocytochemistry(ICC)for p16,p21,p27and α-smooth muscle actin(α-SMA)protein,insitu hybridization(ISH)for retinoic acidreceptor beta 2(RAR-β2)and p16,p21 and p27mRNA and quantitative image analysis(partially)were performed.RESULTS RA inhibited HSC proliferation(41.50%,P【0.05),decreased the protein levelof α-SMA(55.09%,P【0.05),and induced HSCto express RAR-β2 mRNA.In addition,RAincreased the protein level of p16(218.75%,P【0.05)and induced p21 protein expression;meanwhile,p27 was undetectable by ICC in bothcontrol and RA-treated HSC.However,RA hadno influence on the mRNA levels of p16,p21 orp27 as determined by ISH.CONCLISION Up-regulation of p16 and p21 on post-transcriptional level may contribule, in part to RA inhibition of TGF-β1-initiated rat HSC activation in vitro.
基金Supported by National Institutes of Health Grant RO1 AA014891
文摘AIM: To identify signaling pathways and genes that initiate and commit hepatic stellate cells (HSCs) to transdifferentiation. METHODS: Primary HSCs were isolated from male Sprague-Dawley rats and cultured on plastic for 0-10 d. Gene expression was assessed daily (quiescent to day 10 culture-activation) by real time polymerase chain reaction and data clustered using AMADA software. The significance of JAK/STAT signaling to HSC transdifferentiation was determined by treating cells with a JAK2 inhibitor. RESULTS: Genetic cluster analyses, based on expression of these 21 genes, showed similar expression profiles on days 1-3, days 5 and 6, and days 7-10, while freshly isolated cells (day Q) and day 4 cells were genotypically distinct from any of the other days. Additionally, gene expression clustering revealed strong upregulation of interleukin-6, JAK2 and STAT3 mRNA in the early stages of activation. Inhibition of the JAK/STAT signaling pathway impeded the morphological transdifferentiation of HSCs which correlated with decreased mRNA expression of several profibrotic genes including collagens, α-SMA, PDGFR and TGFβR. CONCLUSION: These data demonstrate unique clustered genetic profiles during the daily progression of HSC transdifferentiation and that JAK/STAT signaling may be critical in the early stages of transdifferentiation.
基金This study was supported by the grants from the National Natural Science Foundation of China （No. 30671854）, the National High Technology Research and Development Program of China （863 Program, No. 2006AA02A410）, and the Major State Basic Research Development Program of China （973 Program, No. 2007CB512802）.
文摘Background Hepatitis B is at particularly high risk of fibrosis progression. Unfortunately, the mechanism of hepatic fibrogenesis induced by hepatitis B virus （HBV） has not been fully understood to date. The aim of this study was to observe whether HBV can infect hepatic stellate cells （HSCs）, and to examine the effects of HBV or HBV S protein （HBs） on the proliferation and collagen type I expression of HSCs. Methods The supernatants of HepG2.2.15 cells which contained HBV-DNA or HBs were added to LX-2 cells for 72 hours. Cell survival was determined by MTT assay. HBV particles in LX-2 cells were detected by transmission electron microscopy. The expression of HBs and HBV C protein （HBc） was determined by confocal fluorescence microscopy. The expression levels of HBV-DNA were measured by real-time PCR. The cellular collagen type I mRNA and protein levels were quantified by reverse transcription-PCR and ELISA, respectively. Results High concentrations of HBV （1.2×10^5-5.0×10^5 copies/ml） or HBs （1.25-20 μg/ml） inhibited the proliferation of LX-2 cells, while low concentrations of HBV （1.0×10^3-6.2×10^4 copies/ml） or HBs （0.04-0.62 μg/ml） promoted the proliferation. After treating LX-2 cells with HBV for 72 hours, about 42 nm HBV-sized particles and strong expression of HBs and HBc were found in the cytoplasm of LX-2 cells. HBV-DNA in the culture medium of LX-2 cells decreased at 24 hours, rose at 48 hours and thereafter, decreased again at 72 hours. The mRNA and protein expression of cellular collagen type I in LX-2 ceils were significantly increased by HBV infection but not by recombinant HBs. Conclusions HBV and HBs affect the proliferation of HSCs; HBV can transiently infect and replicate in cultured HSCs and express HBs and HBc in vitro. Furthermore, HBV can significantly increase the expression of collagen type I mRNA and protein in HSCs.
基金Supported by the Natural Science Foundation of Jilin Province of China,No.20190201010JC
文摘Liver fibrosis is a wound-healing response to chronic injuries, characterized by the excessive accumulation of extracellular matrix or scar tissue within the liver;in addition, its formation is associated with multiple cytokines as well as several cell types and a variety of signaling pathways. When liver fibrosis is not well controlled, it can progress to liver cirrhosis, but it is reversible in principle. Thus far, no efficient therapy is available for treatment of liver fibrosis. Although liver transplantation is the preferred strategy, there are many challenges remaining in this approach, such as shortage of donor organs, immunological rejection, and surgical complications. Hence, there is a great need for an alternative therapeutic strategy. Currently, mesenchymal stem cell (MSC) therapy is considered a promising therapeutic strategy for the treatment of liver fibrosis;advantageously, the characteristics of MSCs are continuous self-renewal, proliferation, multipotent differentiation, and immunomodulatory activities. The human umbilical cord-derived (hUC)-MSCs possess not only the common attributes of MSCs but also more stable biological characteristics, relatively easy accessibility, abundant source, and no ethical issues (e.g., bone marrow being the adult source), making hUC-MSCs a good choice for treatment of liver fibrosis. In this review, we summarize the biological characteristics of hUC-MSCs and their paracrine effects, exerted by secretion of various cytokines, which ultimately promote liver repair through several signaling pathways. Additionally, we discuss the capacity of hUC-MSCs to differentiate into hepatocyte-like cells for compensating the function of existing hepatocytes, which may aid in amelioration of liver fibrosis. Finally, we discuss the current status of the research field and its future prospects.
基金Supported by the Brain Korea 21 project in 2004 the Ministry of Agriculture and Forestry project, No. 202059032WTO11
文摘AIM: Silymarin is a potent antioxidant, antiinflammatory and anti-fibrogenic agent in the liver, which is mediated by alteration of hepatic Kupffer cell function, lipid peroxidation, and collagen production. Especially, in hepatic fibrogenesis, mast cells are expressed in chronic inflammatory conditions, and promote fibroblast growth and stimulate production of the extracellular matrix by hepatic stellate cells. METHODS: We examined the inhibitory mechanism of silymarin on CCI4-induced hepatic cirrhosis in rats. At 4, 8, and 12 wk, liver tissues were examined histopathologically for fibrotic changes produced by silymarin treatment. RESULTS: In the silymarin with CCU-treated group, increase of hepatic stellate cells and TGF-β1 production were lower than in the CCI4-treated group at early stages. Additionally, at the late fibrogenic stage, expressions of TGF-β1 were weaker and especially not expressed in hepatocytes located in peripheral areas. Moreover, the number of mast cell in portal areas gradually increased and was dependent on the fibrogenic stage, but those of CCI4+silymarin-treated group decreased significantly. CONCLUSION: Anti-fibrotic and antiinflammatory effects of silymarin were associated with activation of hepatic stellate cells through the expression of TGF-β1 and stabilization of mast cells. These results suggest that silymarin prevent hepatic fibrosis through suppression of inflammation and hypoxia in the hepatic fibrogenesis.
文摘Liver fibrosis is the common pathological basis of all chronic liver diseases,and is the necessary stage for the progression of chronic liver disease to cirrhosis.As one of pathogenic factors,inflammation plays a predominant role in liver fibrosis via communication and interaction between inflammatory cells,cytokines,and the related signaling pathways.Damaged hepatocytes induce an increase in proinflammatory factors,thereby inducing the development of inflammation.In addition,it has been reported that inflammatory response related signaling pathway is the main signal transduction pathway for the development of liver fibrosis.The crosstalk regulatory network leads to hepatic stellate cell activation and proinflammatory cytokine production,which in turn initiate the fibrotic response.Compared with the past,the research on the pathogenesis of liver fibrosis has been greatly developed.However,the liver fibrosis mechanism is complex and many pathways involved need to be further studied.This review mainly focuses on the crosstalk regulatory network among inflammatory cells,cytokines,and the related signaling pathways in the pathogenesis of chronic inflammatory liver diseases.Moreover,we also summarize the recent studies on the mechanisms underlying liver fibrosis and clinical efforts on the targeted therapies against the fibrotic response.
文摘Objective: To investigate the effect of Fuzhenghuayu decoction on autocrine activation of hepatic stellate cell (HSC). Methods: The drug serum containing Fuzhenghuayu decoction was collected from normal rats, and cul- tured with activated HSC in vitro. The conditioned medium from the drug serum treated HSC was added to primary cultured quiescent HSC. Cell prolifera- tion was assayed by tetrazolium colorimetric test, and the contents of type Ⅰ collagen and vascular endo- thelial growth factor (VEGF) in the supernatant were measured with ELISA. Results: The conditioned medium from activated HSC could stimulate the quiescent HSC proliferation and type Ⅰ collagen secretion. The drug serum inhibi- ted this stimulating action and VEGF secretion from the activated HSC. Conclusion: Fuzhenghuayu decoction acts effectively against the autocrine activation pathway of HSC. The mechanism may be associated with the inhibition of the secretion of VEGF by activated HSC.
基金Supported by A grant of the Korea Healthcare Technology R&D Project, Ministry for Health, Welfare and Family Affairs, South Korea (A090183)
文摘Constant alcohol consumption is a major cause of chronic liver disease, and there has been a growing concern regarding the increased mortality rates worldwide. Alcoholic liver diseases (ALDs) range from mild to more severe conditions, such as steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. The liver is enriched with innate immune cells (e.g. natural killer cells and Kupffer cells) and hepatic stellate cells (HSCs), and interestingly, emerging evidence suggests that innate immunity contributes to the development of ALDs (e.g. steatohepatitis and liver fibrosis). Indeed, HSCs play a crucial role in alcoholic steatosis via production of endocannabinoid and retinol metabolites. This review describes the roles of the innate immunity and HSCs in the pathogenesis of ALDs, and suggests therapeutic targets and strategies to assist in the reduction of ALD.
基金supported by National Natural Science Foundation of China (grants 81430091, 81720108032, 81421005, 91429308 and 81603194)the Project for Major New Drug Innovation and Development (grant 2015ZX09501010 and 2017ZX09101003-002-003, China)+3 种基金Overseas Expertise Introduction Project for Discipline Innovation (G20582017001, China)"Double First Class" Initiative Project (CPU2018GF01 and CPU2018GF09, China)State Key Laboratory of Natural Medicines at China Pharmaceutical University (SKLNMZZCX201610 and SKLNMZZCX201801, China)China Postdoctoral Science Foundation (grants 2016M600455 and 2017T100423)
文摘Obeticholic acid(OCA), the first FXR-targeting drug, has been claimed effective in the therapy of liver fibrosis. However, recent clinical trials indicated that OCA might not be effective against liver fibrosis, possibly due to the lower dosage to reduce the incidence of the side-effect of pruritus. Here we propose a combinatory therapeutic strategy of OCA and apoptosis inhibitor for combating against liver fibrosis. CCl4-injured mice, D-galactosamine/LPS(GalN/LPS)-treated mice and cycloheximide/TNFα(CHX/TNFα)-treated HepG2 cells were employed to assess the effects of OCA, or together with IDN-6556, an apoptosis inhibitor. OCA treatment significantly inhibited hepatic stellate cell(HSC)activation/proliferation and prevented fibrosis. Elevated bile acid(BA) levels and hepatocyte apoptosis triggered the activation and proliferation of HSCs. OCA treatment reduced BA levels but could not inhibit hepatocellular apoptosis. An enhanced anti-fibrotic effect was observed when OCA was co-administrated with IDN-6556. Our study demonstrated that OCA inhibits HSCs activation/proliferation partially by regulating BA homeostasis and thereby inhibiting activation of HSCs. The findings in this study suggest that combined use of apoptosis inhibitor and OCA at lower dosage represents a novel therapeutic strategy for liver fibrosis.
