Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells

BACKGROUND Liver fibrosis is the common pathological process associated with the occurrence and development of various chronic liver diseases.At present,there is still a lack of effective prevention and treatment methods in clinical practice.Hepatic stellate cell(HSC)plays a key role in liver fibrogenesis.In recent years,the study of liver fibrosis targeting HSC autophagy has become a hot spot in this research field.Angiotensin-converting enzyme 2(ACE2)is a key negative regulator of reninangiotensin system,and its specific molecular mechanism on autophagy and liver fibrosis needs to be further explored.AIM To investigate the effect of ACE2 on hepatic fibrosis in mice by regulating HSC autophagy through the Adenosine monophosphate activates protein kinases(AMPK)/mammalian target of rapamycin(mTOR)pathway.METHODS Overexpression of ACE2 in a mouse liver fibrosis model was induced by injection of liver-specific recombinant adeno-associated virus ACE2 vector(rAAV2/8-ACE2).The degree of liver fibrosis was assessed by histopathological staining and the biomarkers in mouse serum were measured by Luminex multifactor analysis.The number of apoptotic HSCs was assessed by terminal deoxynucleoitidyl transferase-mediated dUTP nick-end labeling(TUNEL)and immunofluorescence staining.Transmission electron microscopy was used to identify the changes in the number of HSC autophagosomes.The effect of ACE2 overexpression on Wu Y et al.ACE2 improves liver fibrosis through autophagy WJG https://www.wjgnet.com 4976 September 7,2023 Volume 29 Issue 33 autophagy-related proteins was evaluated by multicolor immunofluorescence staining.The expression of autophagy-related indicators and AMPK pathway-related proteins was measured by western blotting.RESULTS A mouse model of liver fibrosis was successfully established after 8 wk of intraperitoneal injection of carbon tetrachloride(CCl4).rAAV2/8-ACE2 administration reduced collagen deposition and alleviated the degree of liver fibrosis in mice.The serum levels of platelet-derived growth factor,angiopoietin-2,vascular endothelial growth factor and angiotensin II were decreased,while the levels of interleukin(IL)-10 and angiotensin-(1-7)were increased in the rAAV2/8-ACE2 group.In addition,the expression of alpha-smooth muscle actin,fibronectin,and CD31 was down-regulated in the rAAV2/8-ACE2 group.TUNEL and immunofluorescence staining showed that rAAV2/8-ACE2 injection increased HSC apoptosis.Moreover,rAAV2/8-ACE2 injection notably decreased the number of autophagosomes and the expression of autophagy-related proteins(LC3I,LC3II,Beclin-1),and affected the expression of AMPK pathway-related proteins(AMPK,p-AMPK,p-mTOR).CONCLUSION ACE2 overexpression can inhibit HSC activation and promote cell apoptosis by regulating HSC autophagy through the AMPK/mTOR pathway,thereby alleviating liver fibrosis and hepatic sinusoidal remodeling.

P2X7 receptor inhibitor suppressed extracellular ATP/LPS-primed human hepatic stellate cells activation via downregulating NLRP3 inflammasome

OBJECTIVE To investigate the effect of P2X7receptor(P2X7r)inhibition,using a specific inhibitor(A438079)to prevent the development of liver fibrosis on human hepatic stellate cells,LX-2.METHODS The supernatant from lipopolysaccharide(LPS)-stimulated RAW264.7 mouse macrophages was supplemented to LX-2 cells for 24 h.LX-2cells were primed with LPS for 4h and subsequently stimulated for 30 min with 3mmol·L-1 of adenosine 5′-triphosphate(ATP).A438079(10μmol·L-1)was supplemented to LX-2 cells 10 min prior to ATP.RESULTS Directly treated with LPS on LX-2 cells,mRNA expressions of IL-1β,IL-18 and IL-6 were increased,as well as P2X7 r.And caspase-1,ASC and NLRP3 mRNA expressions were increased with LPS stimulation.LPS stimulation also increasedα-SMA and collagenⅠ mRNA expressions.Interestingly treatment of LX-2cells with mediums from LPS-primed RAW264.7mouse macrophages exhibited greater increase of mRNA expressions of above genes than those in LX-2directly treated with LPS.Pretreatment of directly or indirectly LPS-stimulated LX-2 cells with A438079 both suppressed IL-1βmRNA expression.In addition treatment of LPS-primed LX-2 cells with 3mmol·L-1 ATP induced the significant increase of IL-1β,IL-6,caspase-1,pannexin-1,α-SMA and collagenⅠ mRNA expression,the increasing ofα-SMA protein expression and cleavage of IL-1β.These events were significantly suppressed by pretreatment with P2X7 rantagonist A438079.P2X7 rblockade also significantly reduced the protein expression ofα-SMA.CONCLUSION Our results suggest that the involvement of the P2X7r-NLRP3 inflammasome pathway in the secretion of IL-1βfrom extracellular ATP/LPS-stimulated human hepatic stellate cells.This study demonstrated that repression of the P2X7 rrepresents a novel potential therapeutic approach to control liver fibrosis.

MicroRNA-194 inactivates hepatic stellate cells and alleviates liver fibrosis by inhibiting AKT2

BACKGROUND Activation of hepatic stellate cells(HSCs)is a pivotal event in the onset and progression of liver fibrosis.Loss of microRNA-194(miR-194)has been reported in activated HSCs,but the actual role of miR-194 in liver fibrosis remains uncertain.AIM To explore the role and potential mechanism of miR-194-mediated regulation of liver fibrosis in vitro and in vivo.METHODS The expression of miR-194 was examined in human fibrotic liver tissues,activated HSCs,and a carbon tetrachloride(CCl4)mouse model by qPCR.The effects of AKT2 regulation by miR-194 on the activation and proliferation of HSCs were assessed in vitro.For in vivo experiments,we reintroduced miR-194 in mice using a miR-194 agomir to investigate the functions of miR-194 in liver fibrosis.RESULTS MiR-194 expression was notably lacking in activated HSCs from both humans and mice.Overexpression of miR-194(OV-miR-194)inhibitedα-smooth muscle actin(α-SMA)and type I collagen(Col I)expression and suppressed cell proliferation in HSCs by causing cell cycle arrest in G0/G1 phase.AKT2 was predicted to be a target of miR-194.Notably,the effects of miR-194 knockdown in HSCs were almost blocked by AKT2 deletion,indicating that miR-194 plays a role in HSCs via regulation of AKT2.Finally,miR-194 agomir treatment dramatically ameliorated liver fibrosis in CCl4-treated mice.CONCLUSION We revealed that miR-194 plays a protective role by inhibiting the activation and proliferation of HSCs via AKT2 suppression.Our results further propose miR-194 as a potential therapeutic target for liver fibrosis.

Expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 in hepatic stellate cells during rat hepatic fibrosis and its intervention by IL-10

AIM: To investigate the expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 in hepatic fibrosis and the antifibrogenic role of exogenous interleukin-10 (IL-10).METHODS: Hepatic fibrosis was induced by CCl4administration and 60 male Sprague-Dawley rats were randomly divided into normal control group (group N, 8rats), CCl4-induced group (group C, 28 rats) and IL-10-treated group (group I, 24 rats). At the beginning of the 7th and 11th wk, rats in each group were routinely perfused with pronase E and type Ⅳ collagenase through portal vein catheter and the suspension was centrifuged by 11%Nycodenz density gradient to isolate hepatic stellate cells (HSCs). RT-PCR was used to analyze mRNA of MMP-2 and TIMP-1 from freshly isolated cells. Densitometric data were standardized with β-actin signals. Immunocytochemistry was performed to detect MMP-2 and TIMP-1 expression in HSC cultured for 72 h.RESULTS: Compared to group N in the 7th wk, MMP-2and TIMP-1 mRNA increased in group C (P= 0.001/0.001)and group I (P = 0.001/0.009). The level of MMP-2 and TIMP-1 mRNA in group I was significantly lower than that in group C (P= 0.001/0.001). In the 11th wk, MMP-2 mRNAin group I was still lower than that in group C (P = 0.005),but both dropped compared with that in the 7th week (P = 0.001/0.004). TIMP-1 mRNA in group I was still lower than that in group C (P= 0.001), and increased in group C (P = 0.001) while decreased in group I (P = 0.042)compared with that in the 7th wk. Same results were found by immunocytochemistry.CONCLUSION: Expression of MMP-2 and TIMP-1 is increased in hepatic fibrosis. IL-10 exhibits an antifibrogenic effect by suppressing MMP-2 and TIMP-1 expression.

Activated rat hepatic stellate cells influence Th1/Th2 profile in vitro

AIM: To investigate the effects of activated rat hepatic stellate cells(HSCs) on rat Th1/Th2 profile in vitro.METHODS: Growth and survival of activated HSCs and CD4+ T lymphocytes cultured alone or together was assessed after 24 or 48 h. CD4+ T lymphocytes were then cultured with or without activated HSCs for 24 or 48 h and the proportion of Th1 [interferon(IFN)-γ+] and Th2 [interleukin(IL)-4+] cells was assessed by flow cytometry. Th1 and Th2 cell apoptosis was assessed after 24 h of co-culture using a caspase-3 staining procedure. Differentiation rates of Th1 and Th2 cells from CD4+ T lymphocytes that were positive for CD25 but did not express IFN-γ or IL-4 were also assessed after 48 h of co-culture with activated HSCs. Galectin-9 expression in HSCs was determined by immunofluorescence and Western blotting. ELISA was performed to assess galectin-9 secretion from activated HSCs.RESULTS: Co-culture of CD4+ T lymphocytes with activated rat HSCs for 48 h significantly reduced the proportion of Th1 cells compared to culture-alone conditions(-1.73% ± 0.71%; P < 0.05), whereas the proportion of Th2 cells was not altered; the Th1/Th2 ratio was significantly decreased(-0.44 ± 0.13; P < 0.05). In addition, the level of IFN-γ in Th1 cells wasdecreased(-65.71 ± 9.67; P < 0.01), whereas the level of IL-4 in Th2 cells was increased(82.79 ± 25.12; P < 0.05) by co-culturing, as measured by mean fluorescence intensity by flow cytometry. Apoptosis rates in Th1(12.27% ± 0.99%; P < 0.01) and Th2(1.71% ± 0.185%; P < 0.01) cells were increased 24 h after co-culturing with activated HSCs; the Th1 cell apoptosis rate was significantly higher than in Th2 cells(P < 0.01). Galectin-9 protein expression was significantly decreased in HSCs only 24 h after coculturing(P < 0.05) but not after 48 h. Co-culture for 48 h significantly increased the differentiation of Th1 and Th2 cells; however, the increase in the proportion of Th2 cells was significantly higher than that of Th1 cells(1.85% ± 0.48%; P < 0.05).CONCLUSION: Activated rat HSCs lower the Th1/Th2 profile, inhibiting the Th1 response and enhancing the Th2 response, and this may be a novel pathway for liver fibrogenesis.

KN-93,a specific inhibitor of CaMKⅡ inhibits human hepatic stellate cell proliferation in vitro

AIM: To investigate the effects of KN-93, a CaMKⅡ selective inhibitor on cell proliferation and the expression of p53 or p21 protein in human hepatic stellate cells. METHODS: Human hepatic stellate cells (LX-2) were incubated with various concentrations (0-50 mmol/L) of KN-93 or its inactive derivative, KN-92. Cell proliferation was measured by CCK-8 assay, and the expression of two cell cycle regulators, p53 and p21, was determined by SDS-PAGE and Western blotting. RESULTS: KN-93 (5-50 mmol/L) decreased the proliferation of human hepatic stellate cells in a dose- dependent manner from 81.76% (81.76% ± 2.58% vs 96.63% ± 2.69%, P < 0.05) to 27.15% (27.15% ± 2.86% vs 96.59% ± 2.44%, P < 0.01) after 24 h treatment. Incubation of 10 mmol/L KN-93 induced the cell growth reduction in a time-dependent manner from 78.27% at 8 h to 11.48% at 48 h. However, KN-92, an inactive derivative of KN-93, did not inhibit cell proliferation effectively. Moreover, analysis of cell cycle regulator expression revealed that KN-93 rather than KN-92 reduced the expression of p53 and p21.

Herbal compound 861 regulates mRNA expression of collagen synthesis- and degradation-related genes in human hepatic stellate cells

AIM:To identify the role of herbal compound 861(Cpd 861)in the regulation of mRNA expression of collagen synthesis-and degradation-related genes in human hepatic stellate cells(HSCs). METHODS:mRNA levels of collagen typesⅠand III,matrix metalloproteinase 1(MMP-1),matrix metalloproteinase 2(MMP-2),membrane type-1 matrix metalloproteinase(MT1-MMP),tissue inhibitor of metalloproteinase 1(TIMP-1),and transforming growth factorβ1(TGF-β1)in cultured-activated HSCs treated with Cpd 861 or interferon-g(IFN-g)were determined by real-time PCR. RESULTS:Both Cpd 861 and IFN-g reduced the mRNA levels of collagen typeⅢ,MMP-2 and TGF-β1.Moreover, Cpd 861 significantly enhanced the MMP-1 mRNA levels while down-regulated the TIMP-1 mRNA expression, increasing the ratio of MMP-1 to TIMP-1 to(6.3+0.3)- fold compared to the control group. CONCLUSION:The anti-fibrosis function of Cpd 861 may be mediated by both decreased interstitial collagen sythesis by inhibiting the transcription of collagen type Ⅲand TGF-β1 and increased degradation of these collagens by up-regulating MMP-1 and down-regulating TIMP-1 mRNA levels.

Efficient generation of functional hepatocytelike cells from mouse liver progenitor cells via indirect co-culture with immortalized human hepatic stellate cells

BACKGROUND： Differentiation of liver progenitor cells（LPCs） to functional hepatocytes holds great potential to develop new strategies for hepatocyte transplantation and the screening of drug-induced cytotoxicity. However, reports on the efficient and convenient hepatic differentiation of LPCs to hepatocytes are few. The present study aims to investigate the possibility of generating functional hepatocytes from LPCs in an indirect co-culture system.METHODS： Mouse LPCs were co-cultured in Transwell plates with an immortalized human hepatic stellate cell line（HSCLi） we previously established. The morphology, expression of hepatic markers, and functions of mouse LPC-derived cells were monitored and compared with those of conventionally cultured LPCs. RESULTS： Co-culturing with HSC-Li cells induced differentiation of mouse LPCs into functional hepatocyte-like cells. The differentiated cells were morphologically transformed into hepatocyte-like cells 3 days after co-culture initiation. In addition, the differentiated cells expressed liver-specific genes and possessed hepatic functions, including glycogen storage, lowdensity lipoprotein uptake, albumin secretion, urea synthesis, and cytochrome P450 1A2 enzymatic activity.CONCLUSIONS： Our method, which employs indirect co-culture with HSC-Li cells, can efficiently induce the differentiation of LPCs into functional hepatocytes. This finding suggests that this co-culture system can be a useful method for the efficient generation of functional hepatocytes from LPCs.

Advances in In-vitro Culture Technology of Human Fetal Hepatic Stellate Cells

Liver is an important organ for human metabolism and biological conversion. Medical research on hepatic disease clinic, drug metabolism and drug effi- cacy evaluation all needs an in-vitro model of liver as a research platform. Hepatic stellate cells are core cells for occurrence and development of liver fibrosis. Stud- ies at home and abroad deemed that human fetal hepatic stellate cells are an ideal material for the construction of an in-vitro research model for liver fibrosis. With clinical and basic research of liver going deeper, the requirements to quantity and quality of in-vitro models of fetal hepatic stellate cells become higher and higher. The advances in isolation, culture and cryopreservation technique of human fetal hepatic stellate cells were reviewed in this paper.

P2X7r antagonist suppressed hepatic stellate cells activation through NLPR3 inflammasome signaling

P2X7 receptor （P2X7r） is important in inflammation and fibrosis. The aim of the present study was to investigate the effect of P2X7r inhibition, using a specific inhibitor （A438079） to prevent the development of liver fibrosis on human hepatic stellate cells, LX-2. The supernatant from lipopolysaccharide （LPS）-stimulated RAW 264.7 mouse macrophages was supplemented to LX-2 cells for 24 h. LX-2 cells were primed with LPS for 4 h and subsequently stimulated for 30 rain with 3 mmol · L^-1 of adenosine 5＇-triphosphate （ATP）. A438079 （ 10 μmol · L^-1） was supplemented to LX-2 cells 10 rain prior to ATP. Directly treated with LPS on LX-2 cells, mRNA ex- pressions of IL-1β, IL-18 and IL-6 were increased, as well as P2X7r. And caspase-1, ASC and NLRP3 mRNA ex- pressions were increased with LPS stimulation. LPS stimulation also increased oL-SMA and collagen I mRNA expres- sions. Interestingly treatment of LX-2 cells with mediums from LPS-primed RAW 264.7 mouse macrophages exhibi- ted greater increase of mRNA expressions of above genes than those in LX-2 directly treated with LPS. Pretreatment of directly or indirectly LPS-stimulated LX-2 cells with A438079 both suppressed IL-1β mRNA expression. In addi- tion treatment of LPS-primed LX-2 cells with 3 mM ATP induced the significant increase of IL-1β, IL-6, caspase- 1, pannexin-1, α-SMA and collagen I mRNA expression, the increasing of oL-SMA protein expression and cleavage of IL-1β. These events were significantly suppressed by pretreatment with P2X7r antagonist A438079. P2XTr blockade also significantly reduced the protein expression of oL-SMA. Our results suggest that the involvement of the P2X7r-NLRP3 inflammasome pathway in the secretion of IL-1β from extracellular ATP/LPS-stimulated human he- patic stellate cells. This study demonstrated that repression of the P2XTr represents a novel potential therapeutic ap- proach to control liver fibrosis.

Role of cyclooxygenase-2 in lipid metabolism in hepatic stellate cells

Hepatic stellate cells(HSCs) are a kind of adipocytes. In HSCs lipids mainly exist in the form of lipid droplets. They are abundantly found in the cytoplasm and their main constituents are triglycerides. Lipid metabolism in HSCs is closely related to its biological activity, however the mechanism of lipid droplets disappearance after HSC activation is not clearly established yet. Recent research shows that, cyclooxygenase-2 plays an important regulatory role in the lipid metabolism of HSCs. This paper seeks to review the subject based on studies that have been conducted so far to understand the role of cyclooxygenase-2 in the metabolism of lipids in HSCs.

Switching-on of serotonergic calcium signaling in activated hepatic stellate cells

AIM:To investigate serotonergic Ca 2+ signaling and the expression of 5-hydroxytryptamine(5-HT) receptors,as well as Ca 2+ transporting proteins,in hepatic stellate cells(HSCs) . METHODS:The intracellular Ca 2+ concentration([Ca 2+ ]i) of isolated rat HSCs was measured with a fluorescence microscopic imaging system.Quantitative PCR was per-formed to determine the transcriptional levels of 5-HT receptors and endoplasmic reticulum(ER) proteins involved in Ca 2+ storage and release in cultured rat HSCs. RESULTS:Distinct from quiescent cells,activated HSCs exhibited[Ca 2+ ]i transients following treatment with 5-HT,which was abolished by U-73122,a phospholipase C inhibitor.Upregulation of 5-HT2A and 5-HT2B receptors,but not 5-HT3,was prominent during trans-differentiation of HSCs.Pretreatment with ritanserin,a 5-HT2 antagonist,inhibited[Ca 2+ ]i changes upon application of 5-HT.Expression of type 1 inositol-5'-triphosphate receptor and type 2 sarcoplasmic/endoplasmic reticulum Ca 2+ ATPase were also increased during activation of HSCs and serve as the major isotypes for ER Ca 2+ storage and release in activated HSCs.Ca 2+ binding chaperone proteins of the ER,including calreticulin,calnexin and calsequestrin,were up-regulated following activation of HSCs. CONCLUSION:The appearance of 5-HT-induced[Ca 2+ ]i response accompanied by upregulation of metabotropic 5-HT2 receptors and Ca 2+ transporting/chaperone ER proteins may participate in the activating process of HSCs.

KLF4 Inhibits the Activation of Human Hepatic Stellate Cell In Vitro

Objective Hepatic stellate cells(HSCs)play a crucial role in liver fibrosis.Early-stage liver fibrosis is reversible and intimately associated with the state of HSCs.Kruppel-like factor 4(KLF4)plays a pivotal role in a wide array of physiological and pathological processes.This study aimed to investigate the effect of KLF4 on the proliferation,apoptosis and phenotype of quiescent HSCs Methods We designed a KLF4 lentiviral vector and a KLF4 siRNA lentiviral vector,to upregulate and silence KLF4 expression in human HSC LX-2 cells via transfection.Cell proliferation was assessed using the CCK-8 assay.Flow cytometry was used to detect the cell cycle distribution and apoptosis rate.Western blotting was used to determine the levels of some quiescence and activation markers of HSCs Results Overexpression of KLF4 significantly increased the levels of E-cadherin and ZO-1,which are quiescent HSC markers,while significantly decreased the levels of N-cadherin and a-SMA,known activated HSC markers.In contrast,cell proliferation and apoptosis rates were elevated in LX-2 cells in which KLF4 expression was silenced Conclusion KLF4 inhibits the proliferation and activation of human LX-2 HSCs.It might be a key regulatory protein in the maintenance of HSC quiescence and may serve as a target for the inhibition of hepatic fibrosis.

肝星状细胞特异性Grk2基因敲除小鼠模型的制备及鉴定

目的利用Cre-loxP基因敲除技术建立肝星状细胞特异性G蛋白偶联受体激酶2(G protein-coupled receptor kinase 2,GRK2)基因敲除小鼠模型,为研究GRK2在肝星状细胞中的生物学功能提供动物模型基础。方法将loxP标记的Grk2基因小鼠(Grk2^(fl/fl))和Lrat-Cre工具鼠进行多次繁殖,建立肝星状细胞特异性Grk2基因敲除(Grk2^(ΔHSC))小鼠模型。观察和分析小鼠的生长繁殖情况;通过PCR反应鉴定flox和Cre基因型;免疫荧光双染检测肝星状细胞中GRK2表达;Western blot检测小鼠肝星状细胞及肺、脾、肾脏、心脏组织中GRK2蛋白表达;HE染色观察肝脏及肺、脾、心脏、肾脏组织学形态。结果成功鉴定Grk2^(ΔHSC)小鼠基因型;两组小鼠体质量、繁殖能力无明显差异;免疫荧光双染及Western blot结果表明,Grk2^(ΔHSC)小鼠的肝星状细胞中GRK2蛋白水平明显低于对照组小鼠,Grk2^(ΔHSC)小鼠肺、脾、肾脏和心脏组织中GRK2蛋白表达与对照组相比无明显变化;HE染色结果显示,Grk2^(ΔHSC)小鼠肝脏及主要组织结构与Grk2^(fl/fl)相比差异无显著性,可用于后续研究。结论本研究应用Cre-loxP技术成功构建了肝星状细胞特异性Grk2基因敲除小鼠,为进一步研究GRK2在肝脏中的作用提供了优良工具。

Angiotensin-converting enzyme 2 alleviates liver fibrosis through the renin-angiotensin system

The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can alleviate liver fibrosis by regulating autophagy of hepatic stellate cells and affecting the renin-angiotensin system.

姜黄素对人肝星状细胞株LX-2瘦素和脂联素表达的影响

目的观察姜黄素对人肝星状细胞株LX-2瘦素和脂联素表达的影响,探讨瘦素和脂联素在姜黄素抗肝纤维化中的作用。方法体外培养人肝星状细胞株LX-2,分别给予0、10、20、30、40、50、60、70、80μmol/L的姜黄素处理,MTT法检测细胞增殖并绘制增殖曲线;根据增殖检测结果,选取30、40、50μmol/L姜黄素分别作用于LX-2,免疫细胞化学染色方法分别检测细胞中瘦素、脂联素的表达,计算阳性表达率。结果 10、20μmol/L姜黄素作用下LX-2增殖与0μmol/L姜黄素比较差异无统计学意义(P>0.05);在30～80μmol/L浓度范围内,LX-2增殖明显降低(P<0.05)。正常LX-2的瘦素和脂联素表达率分别为(90.40±8.37)%和(29.88±3.79)%,30～50μmol/L姜黄素处理24 h后,瘦素表达减少,依次为(78.83±6.81)%、(52.60±4.67)%和(34.02±4.50)%,而脂联素表达升高,依次为(48.69±8.34)%、(73.86±5.73)%和(83.22±3.92)%,与正常LX-2细胞比较差异均有统计学意义(P<0.05)。结论姜黄素可通过抑制肝星状细胞中瘦素表达,诱导脂联素表达而发挥抑制细胞增殖、抗肝纤维化作用。

橘皮素的提取分离、改性及对人体肝星状细胞LX-2的抑制作用

通过分离纯化及改性得到橘皮素和5-去甲氧基橘皮素,并研究其对人体肝星状细胞株LX-2的抑制作用。通过无水乙醇提取、氯仿萃取从陈皮中得到多甲基黄酮混合物,再以不同浓度的乙酸乙酯和石油醚的混合液为洗脱剂,采用硅胶柱层析分离纯化多甲基黄酮混合物,得到橘皮素纯品。将橘皮素置于盐酸乙醇溶液中回流,对所得产物进行纯化即可得5-去甲氧基橘皮素,采用质谱和核磁共振谱进行结构确证。利用人体肝星状细胞株LX-2细胞作为工具细胞,研究其生物活性。结果表明,5-去甲氧基橘皮素在12.5μmol/L条件下对人肝星状细胞株LX-2的抑制率即可达到50%,而橘皮素需要在近150μmol/L条件下才能达到50%的抑制率,即改性后的橘皮素对人体肝细胞的抑制有效率增加了10倍以上。

护肝布祖热对CCl4诱导人肝星状细胞LX-2活化的作用及机制研究

目的探讨护肝布祖热(HGBZR)抗肝损伤的作用及机制。方法体外培养人肝星状细胞LX-2,采用MTT法检测LX-2细胞存活率以确定四氯化碳(CCl)造模浓度和药物干预浓度。细胞实验分为6组:空白组、模型组、阳性组(水飞蓟素,10μg·mL)及HGBZR低、中、高剂量组(5、10、20μg·mL),除空白组以外,其余各组分别加入终浓度5 mmol·L^(-1)CCl损伤干预24 h,然后再进行药物干预24 h。采用MTT法检测各组细胞存活率;Annexin V/PE双染法检测细胞凋亡率;qRT-PCR法检测各组细胞α-平滑肌动蛋白(SMA)、TIMP-1、PTP1B、转化生长因子(TGF)-β、Smad3、Smad4、Smad7、CHOP、PERK、IRE1、ATF6 mRNA表达情况;Western Blot法检测各组细胞Jak1、Stat3、TGF-β、Smad3、Smad4、Smad7、CHOP、Caspase12、核因子(NF)-κB p65蛋白表达情况。结果随着CCl浓度(5~30 mmol·L^(-1))升高,LX-2细胞存活率逐渐下降,当CCl浓度为5 mmol·L^(-1)时细胞呈现增殖状态,故选择5 mmol·L^(-1)CCl处理24 h作为肝损伤模型复制条件。与模型组比较,HGBZR中、高剂量组的细胞存活率明显降低(P<0.05),细胞早期凋亡率和晚期凋亡率均明显升高(P<0.05);LX-2细胞的α-SMA、TIMP-1、TGF-β、Smad3、Smad4、CHOP、PERK、IRE1、ATF6 mRNA表达水平明显降低(P<0.05),PTP1B、Smad7 mRNA表达水平明显升高(P<0.05);LX-2细胞的Jak1、Stat3、TGF-β、Smad4、CHOP、Caspase12及NF-κB p65(核蛋白)蛋白表达水平明显降低(P<0.05),Smad7、NF-κB p65(质蛋白)蛋白表达水平明显升高(P<0.05),Smad3蛋白表达水平无明显变化(P>0.05)。结论HGBZR可能通过调控TGF-β/Smad、Jak/Stat和内质网应激信号通路相关目标基因转录水平及蛋白表达,促进活化LX-2细胞的凋亡,对CCl诱导的化学性肝损伤具有一定保护作用。

IL-10-HGF融合基因对肝星状细胞LX-2增殖的抑制作用

目的探讨人白介素-10(IL-10)与人肝细胞生长因子(HGF)融合基因对肝星状细胞LX-2增殖的抑制作用。方法采用PCR方法,分别构建pcDNA3.1-flag-IL-10、pcDNA3.1-flag-HGF与pcDNA3.1-flag-IL-10-HGF真核表达载体,瞬时转染肝星状细胞LX-2;利用RT-PCR和Western blot检测LX-2细胞中IL-10、HGF的表达;选用MTT法检测转染24、48和72 h后LX-2细胞的增殖情况。结果成功构建了IL-10-HGF融合基因真核表达载体pcDNA3.1-flag-IL-10-HGF。与pcDNA3.1-flag-IL-10和pcDNA3.1-flag-HGF组比较,pcDNA3.1-flag-IL-10-HGF融合组48 h和72 h LX-2细胞数减少(n=3,P<0.05)。结论 IL-10-HGF融合基因可有效抑制肝星状细胞LX-2的增殖。

酒精性肝病患者血浆白细胞介素-21水平及重组IL-21对LX-2肝星状细胞增殖和活化的影响

目的：分析酒精性肝病患者血浆白细胞介素-21（IL-21）水平及重组IL-21体外对LX-2肝星状细胞增殖和活化的影响。方法采用ELISA法检测17例酒精性肝炎、51例酒精性肝硬化患者和20例健康人血浆IL-21水平；体外培养LX-2肝星状细胞，以IL-21（1ng/ml或10ng/ml）处理24 h或48 h，检测LX-2细胞增殖及α-平滑肌肌动蛋白表达。结果与健康对照人群比，酒精性肝炎和酒精性肝硬化患者血浆IL-21水平均显著升高（P＆lt;0.05），但酒精性肝炎和肝硬化患者之间无显著性差异，不同Child分级的肝硬化患者之间也无显著性差异；在IL-21作用24～48 h后，LX-2细胞增殖水平与对照组比无显著性差异，但α-平滑肌肌动蛋白表达均较对照组显著升高。结论血浆IL-21可能通过促进肝星状细胞活化参与了酒精性肝病患者肝纤维化的发生和发展。