Fermented Lentinus edodes extract containingα-glucan ameliorates concanavalin A-induced autoimmune hepatitis in mice

Autoimmune hepatitis(AIH)is a chronic inflammatory liver disease that threatens human health worldwide.The aim of this study was to detect the protective effect of a fermented Lentinus edodes extract containingα-glucan(FLA),in a concanavalin A(Con A)-induced AIH mouse model and to determine the underlying liver-protective mechanism.The results showed that compared with the model group,the level of proinflammatory cytokines in serum of FLA pretreated mice was significantly decreased,and the degree of inflammatory cell infiltration in liver,thymus and spleen was significantly reduced.Quantitative polymerase chain reaction,immunohistochemistry,and Western blotting showed that FLA pre-treatment inhibited the Con A-induced apoptosis of hepatocytes by down-regulating the expression of BAX and up-regulating the expression of BCL-2.Further research found that FLA may improve liver injury in mice by activating NRF2 signaling pathway and inhibiting TRAF6/NF-κB signaling pathway.Thus,FLA may improve liver injury in mice by shifting gut microbial composition to reduce the release of inflammatory cytokines in the serum and prevent the necrosis of hepatocytes.Up-regulation of NRF2 signaling pathway,down-regulation of TRAF6/NF-κB signaling pathway,and an increase in the relative abundance of Lactobacillus_johnsonii and Ligilactobacillus_murinus play a protective role in liver.

Notch signaling mediated by TGF-β/Smad pathway in concanavalin A-induced liver fibrosis in rats

AIM To explore the exact interaction between Notch and transforming growth factor(TGF)-β signaling in liver fibrosis. METHODS We established a rat model of liver fibrosis induced by concanavalin A. Peripheral blood mononuclear cells(PBMCs) were isolated from the modeled rats, and cultured with γ-secretase inhibitor DAPT and TGF-β inhibitor for 24 h. The m RNA levels of Notch and TGF-β signaling were detected by quantitative real-time polymerase chain reaction. Expression of Notch and TGF-β proteins was analyzed by western blotting.RESULTS Compared to control rats, Notch and TGF-β signaling was activated in PBMCs of model rats. Administration of DAPT and TGF-β inhibitor suppressed Notch and TGF-β signal transducer in PBMCs of model rats. DAPT reduced m RNA and protein expression of TGF-β signaling, such as TGF-β1 and Smad3. TGF-β inhibitor also downregulated Notch1, Hes1 and Hes5, and m RNA and protein expression of the Notch signaling pathway.CONCLUSION Notch and TGF-β signaling play a role in liver fibrosis. TGF-β signaling upregulates Notch signaling, which promotes TGF-β signaling.

Immune mechanisms of Concanavalin A model of autoimmune hepatitis

As a chronic inflammatory disease of the liver,the pathogenic mechanisms of autoimmune hepatitis (AIH) have not yet been elucidated,with prognosis and diagnosis remaining unsatisfied.Currently the only viable treatments of AIH are immunosuppressant application and liver transplantation.It is considered that lack of good animal AIH models is the main reason for the shortage of a simple and efficient cure.The Concanavalin A (Con A) model is a typical and well established model for investigating T-cell and macrophage dependent liver injury in mice,which closely mimics the pathogenesis mechanisms and pathological changes of patients,and is regarded as the best experimental model for AIH research so far.In this paper we eluci-dated the pathogenic mechanisms of AIH and the evolution of relative animal models.We go on to further focus on Con A-induced liver injury from the point of immunological mechanisms and the change of cytokine levels.Finally,we manifested the clinical significance of the AIH animal models and the challenges they would meet during their future development.

Interleukin-22 contributes to liver regeneration in micewith concanavalin A-induced hepatitis after hepatectomy

AIM: To investigate the therapeutic effects and mechanisms of interleukin(IL)-22 in liver regeneration in mice with concanavalin A(Con A)-induced liver injury following 70% hepatectomy.METHODS: Mice were injected intravenously with Con A at 10 μg/g body weight 4 d before 70% hepatectomy to create a hepatitis model, and recombinant IL-22 was injected at 0.125 μg/g body weight 30 min prior to 70% hepatectomy to create a therapy model. Control animals received an intravenous injection of an identical volume of normal saline.RESULTS: IL-22 treatment prior to 70% hepatectomy performed under general anesthesia resulted in reductions in the biochemical and histological evidence of liver injury, earlier proliferating cell nuclear antigen expression and accelerated recovery of liver mass. IL-22 pretreatment also significantly induced signal transducer and activator of transcription factor 3(STAT3) activation and increased the expression of a variety of mitogenic proteins, such as Cyclin D1. Furthermore, alpha fetal protein m RNA expression was significantly elevated after IL-22 treatment.CONCLUSION: In this study, we demonstrated that IL-22 is a survival factor for hepatocytes and prevents and repairs liver injury by enhancing pro-growth pathways via STAT3 activation. Treatment with IL-22 protein may represent a novel therapeutic strategy for preventing liver injury in patients with liver disease who have undergone hepatectomy.

Kupffer cells contribute to concanavalin A-induced hepatic injury through a Th1 but not Th17 type response-dependent pathway in mice

BACKGROUND:Increasing evidence suggests that a close interaction of Kupffer cells with T cells plays a central role in concanavalin A-induced hepatic injury in mice,but the underlying mechanisms remain obscure.The present study aimed to determine the relative roles of Th1 and Th17 type responses in concanavalin A-induced hepatic injury in mice, and to investigate whether or not Kupffer cells contribute to hepatic injury via a Th1 or Th17 type response-dependent pathway. METHODS:Immune-mediated hepatic injury was induced in C57BL/6 mice by intravenous injection of concanavalin A. Kupffer cells were inactivated by pretreatment with gadolinium chloride 24 hours before the concanavalin A injection.The interferon-gamma(IFN-γ)and interleukin-17(IL-17)pathways were blocked by specific neutralizing antibodies.Hepatic injury was assessed using serum transferase activity and pathological analysis.Expression of inflammatory cytokines within the liver was detected by real-time polymerase chain reaction and immunohistochemistry. RESULTS:Neutralization of IFN-γsignificantly attenuated concanavalin A-induced hepatic injury.However,neutralization of IL-17 failed to suppress the injury.Inactivation of Kupffer cells by gadolinium chloride pretreatment protected against concanavalin A-induced injury and significantly reduced hepatic cytokine levels including TNF-α,IL-6 and IFN-γbut not IL-17.CONCLUSION:Our findings suggest that Kupffer cells contribute to concanavalin A-induced hepatic injury via a Th1 type response-dependent pathway and production of inflammatory cytokines including TNF-α,IL-6 and IFN-γ.

Stem cells from human exfoliated deciduous teeth ameliorate concanavalin A-induced autoimmune hepatitis by protecting hepatocytes from apoptosis

BACKGROUND Autoimmune hepatitis is a serious autoimmune liver disease that threatens human health worldwide,which emphasizes the urgent need to identify novel treatments.Stem cells from human exfoliated deciduous teeth(SHED),which are easy to obtain in a non-invasive manner,show pronounced proliferative and immunomodulatory capacities.AIM To investigate the protective effects of SHED on concanavalin A(ConA)-induced hepatitis in mice,and to elucidate the associated regulatory mechanisms.METHODS We used a ConA-induced acute hepatitis mouse model and an in vitro co-culture system to study the protective effects of SHED on ConA-induced autoimmune hepatitis,as well as the associated underlying mechanisms.RESULTS SHED infusion could prevent aberrant histopathological liver architecture caused by ConA-induced infiltration of CD3+,CD4+,tumor necrosis-alpha+,and interferon-gamma+inflammatory cells.Alanine aminotransferase and aspartate aminotransferase were significantly elevated in hepatitis mice.SHED infusion could therefore block ConA-induced alanine aminotransferase and aspartate aminotransferase elevations.Mechanistically,ConA upregulated tumor necrosisalpha and interferon-gamma expression,which was activated by the nuclear factor-kappa B pathway to induce hepatocyte apoptosis,resulting in acute liver injury.SHED administration protected hepatocytes from ConA-induced apoptosis.CONCLUSION SHED alleviates ConA-induced acute liver injury via inhibition of hepatocyte apoptosis mediated by the nuclear factor-kappa B pathway.Our findings could provide a potential treatment strategy for hepatitis.

A comparative study of changing patterns of concanavalin A-binding proteins in early stage of cholesterol gallstone

IM To elucidate the importance and the changing patterns of biliary concanavalin Abinding proteins (CPs) in the early stage of cholesterol gallstone.METHODS CPs concentrations and nucleation activities were measured by lectin affinity chromatography in biles of patients with cholesterol gallstone, pigment gallstone, gallbladder cholesterosis and nonbiliary diseases.RESULTS The concentrations of CPs were much higher in patients with cholesterol gallstone (039g/L±011g/L, n=36, P<001) or gallbladder cholesterosis (040g/L±009g/L, n=9, P<001) than in those with pigment gallstone (026g/L±012g/L, n=7) and/or nonbiliary diseases (027g/L±009g/L, n=10). Pronucleating activities were much stronger in patients with cholesterol gallstones (nucleation time ratio: 057±021, n=5, P<001 vs pigment gallstone and/or nonbiliary diseases) and gallbladder cholesterosis (nucleation time ratio: 044±023, n=5, P<001 vs pigment gallstone or nonbilliary diseases). The binding percentages of CPs to model biliary vesicles were also higher in patients with cholesterol gallstones (n=6) than those with pigment gallstones (n=6) (24%±09% vs 09%±05%, P<001).CONCLUSION Hypersecretion of CPs, especially those in vesicular phase may be the important changes in the early stage of cholesterol gallstone.

Immunomodulatory effect of schisandrae oil in mouse model of autoimmune hepatitis induced by concanavalin A

Objective:To study the immunomodulatory effect of schisandra oil (SCO) in mouse model of autoimmune hepatitis induced by concanavalin A (ConA). Methods: C57BL/6 mice were divided into control group, model group and SCO group. Mice in SCO group were given SCO at 5 mg/kg by intragastric administration every day for 7 days, followed by intravenous injection of ConA at 10 mg/kg. 10 hours after ConA injection, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were measured by the kits, the expression of inflammatory cytokines like interferon-γ(IFN-γ), interleukin-4 (IL-4), interleukin-17 (IL-17), tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β) and interleukin-6 (IL-6) in liver was detected by real-time quantitative PCR, and the T cell activation and IFN-γ expression in spleen and MLN were examined by flow cytometry. Results: Compared with control group, each indicator in model group were significantly higher. In SCO preventive treatment group, the levels of serum ALT, AST and LDH were significantly reduced (all P < 0.001), the expression levels of inflammatory cytokines in liver were downregulated, the T cell activation in spleen and MLN was inhibited (P = 0.006 and P = 0.008), the percentages of IFN-γ+ CD8+ and IFN-γ+ CD4+ T cells were decreased, and the frequencies of Th2 and Th17 cells in spleen and MLN were also decreased at the same time. Conclusion: SCO has a protective effect on immune liver injury by inhibiting the activation of T cells and reducing the expression of inflammatory cytokines, which reflects that SCO plays a role in the immunomodulation of autoimmune hepatitis, indicating that SCO is of great significance for the maintenance of autoimmune homeostasis.

Concanavalin A-induced changes in lysosomal morphology of macrophages under confocal microscope

Changes in lysosomal morphology of cultured mouse peritoneal macrophages after stimu1ation by Concanavalin A (Con A) were observed with a laser scanning confocal microscope (LSCM). A series of images were obtained including phase-contrast images, optical sectioning images, 3-dimensional reconstruction images. The changes of lysosomal fluorescence intensity and pH were measured. It was found that macrophage lysosomes were Cllstributed mainly at the periphery of the cells in resting conditions, the lysosomal area containing fluorescence probe became markedly enlarged after stimulation by Con A for 30 min, and the fluorescence intensity in the medium increased about 15 min after suggesting that Con A could induce outflow of the fluorescence probe within the macrophage lysosomes. The lysosomal pH rose from 4. 6 to 5. 7 in 7 min after Con A was added, and maintained at that level hereafter.

Effects of interleukin-18 and Anti-interleukin-18-mAb on Experimental immunological Liver Fibrosis induced by Repeatedly Administered Concanavalin A and its Mechanism

Objective To explore the prevention of IL-18 or anti-IL-18-m Ab to the immune liver fibrosis model induced by repeated injection of concanavalin A in BALB/c mice and its mechanism.Methods Total of 120 BALB/c mice were divided into four groups, control group mice(Ga) were injected weekly with normal saline, concanavalin A group was divided into Gb, Gc, Gd. All mice were injected with concanavalin A(15 mg/kg) once a week. Moreover, Gc, Gd mice were injected weekly with IL-18(7.5 mg/kg) and anti-IL-18-m Ab(10 mg/kg) 2 hours before treatment with concanavalin A, respectively. Twenty-four hours after concanavalin A challenge at 1, 5, 12 and 20 weeks, 3 mice were killed by vena orbitalis, repectively. The sera were storaged at 4℃ for detecting of up TNF-α and IFN-γ by ELISA. The liver of mice in different groups were excised and fixed in 10% formalin for HE staining and Masson staining or frozen in liquid nitrogen for immunohistochemical staining for α-SMA. After extracting of total RNA from liver tissue, MMP-2 and TIMP-1A messenger RNA were amplified by reverse transcription polymerase chain reaction(PCR). Products were electrophoresed on agrose gel containing ethidium bromide and visualized under ultraviolet light. Densitometric RT-PCR data were standardized with β-actin signals. Results After experiment, the number of dead mice of Ga, Gb, Gc and Gd were 0, 6, 15 and 3, respectively. There were significant difference on each group(P < 0.05). At the fifth week of experiment, hepatocellular necrosis in IL-18 administered group mice had become widespread throughout the lobule. Evidence of liver fibrosis was observed during this period. However, at the twelfth week of experimemt, bridging fibrosis and large fibrosis strip in the parenchyma with hepatocellular necrosis was detectable in Gb, but at twentieth week, only the small fibrosis strip had been found in anti-IL-18-mA b administered group mice by HE staining and Masson staining. The serum levels of TNF-α and IFN-γ in IL-18 administered group were higher than that in concanavalin A group and anti-IL-18 administered groups(P < 0.05). Moreover, immunohistochemical staining for α-SMA indicated that the semi-quantu scores in IL-18 administered group were more than concanavalin A group and anti-IL-18-mA b administered groups(P < 0.05). MMP-2-mR NA, TIMP-1- mR NA expression levels increased signifigantly compared with concanavalin A group and anti-IL-18-mA b administered group(P < 0.05).Conclusions The immune liver fibrosis model induced by repeated injection of concanavalin A in BALB/c mice could be worsened by IL-18 administration and block by anti-IL-18 mA b administraion.

五味子乙素诱导的HSP27和HSP70对Con A诱导小鼠肝损伤的保护作用

目的探讨五味子乙素(Sch B)对刀豆蛋白A(Concanavalin A,Con A)诱导小鼠肝损伤的保护作用与HSP27和HSP70的关系。方法采用静脉注射Con A诱导小鼠免疫性肝损伤模型,Sch B和热休克蛋白抑制剂槲皮素(Quercetin)灌胃给药。取4周龄雄性ICR小鼠72只,体质量18～22 g,按体质量分为6组:正常对照组、模型组(Con A)、Sch B+Con A组、Sch B+Con A+Quercetin组、Con A+Quercetin组和Quercetin组。Western blot法检测小鼠肝脏HSP27和HSP70蛋白的表达;实时荧光定量PCR法检测小鼠肝脏HSP27和HSP70 mRNA的表达;光镜下观察肝脏组织病理学改变;试剂盒检测小鼠血清转氨酶水平。结果与ConA组相比,Sch B+Con A组小鼠肝脏HSP27和HSP70在蛋白水平和mRNA水平的表达均显著增加,同时肝细胞坏死程度明显减轻、小鼠血清转氨酶水平显著降低。与Sch B+Con A组相比,Sch B+Con A+Quercetin组小鼠肝脏HSP27和HSP70在蛋白水平和mRNA水平的表达均明显降低,同时小鼠肝细胞坏死程度明显增加、血清转氨酶水平显著增高。而与正常对照组相比,Quercetin组小鼠的上述各项指标未见改变。结论 SchB可通过诱导小鼠肝脏HSP27和HSP70的表达保护Con A所致的小鼠免疫性肝损伤。

苦参碱对Con A性肝损伤小鼠IFN释放及肝组织病理改变的影响

目的:观察苦参碱对刀豆蛋白A(Con A)性肝损伤小鼠IFN-γ和TNF-α释放及肝组织病理改变的影响. 方法:NIH小鼠48只随机分为5组,分别为正常对照组,模型组,苦参碱大剂量组(25 mg/kg),苦参碱小剂量组(12.5 mg/kg)和联苯双酯治疗组.除正常对照组外,其他组于实验首日iv Con A 20 mg/kg,苦参碱大剂量组和小剂量组均采用尾iv给药,联苯双酯组按150 mg/kg 灌胃,每天1次,连续3 d,末次给药后4 h,再次iv Con A 20 mg/kg,8 h采血检测血浆IFN-γ和TNF-α含量、ALT活性,观察肝组织病理学变化. 结果:苦参碱大剂量组、小剂量纽小鼠IFN-γ和TNF-α含量均明显低于模型组(IFN-γ:25.5±6.1 vs 69.3±33.6 ng/L,26.5±2.5 vs 69.3±33.6 ng/L,t=4.0,4.0, P<0.01;TNF-α:49.1±11.9 vs 106.7±64.4 ng/L,52.9±5.2 vs 106.7±64.4 ng/L,t=2.9,2.9,P<0.01),但与联苯双酯组比较,差异无显著性意义(P>0.05);苦参碱大、小剂量组血浆ALT活性明显低于模型组(1 086.9 ±675.8 vs 2 477.2±529.9 nkat/L、1 121.9±957.4 vs 2 477.2±529.9 nkat/L,t=5.1,3.9,P<0.01),且可明显减轻肝细胞坏死及炎性细胞浸润的肝组织病理学改变,与模型组比较差异有显著性意义(P<0.05). 结论:苦参碱对刀豆蛋白A性肝损伤小鼠释放IFN-γ和TNF-α有明显的抑制作用.并可显著减轻肝组织病理改变.

藏药波棱瓜子总木脂素对刀豆球蛋白(ConA)致免疫性肝损伤小鼠保护作用及其机制探讨

目的:波棱瓜子是常见的用于治疗肝病的藏药,疗效确切.前期研究表明,总木脂素是波棱瓜子抗肝损伤的有效部位,但疗效尚不明确.本研究拟考察藏药波棱瓜子总木脂素对ConA致小鼠免疫性肝损伤的保护作用,并进一步探讨其对抗肝损伤的作用机制.方法:采用尾静脉注射一次性ConA(20mg/kg)诱发小鼠免疫性肝损伤,造模8h后取血样和肝脏,考察不同剂量的波棱瓜子总木脂素对各组小鼠脏器系数、血清丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、碱性磷酸酶(ALP)、骨过氧化物酶(MPO)、一氧化氮(NO)、一氧化氮合酶(NOS)及肝组织匀浆中超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px)等生化指标活力或水平的影响;以HE染色对肝组织进行组织病理学检查;免疫组织化学法检测波棱瓜子总木脂素对各组小鼠肝脏中肿瘤坏死因子-α(TNF-α)、干扰素-γ(IFN-γ)、白细胞介素-4(IL-4)、白细胞介素-10(IL-10)、核转录因子-κB(NF-κB)表达的影响.结果:波棱瓜子总木脂素可以降低ConA所致免疫性肝损伤小鼠肝脏系数及血清ALT、AST、ALP活力,显示出较好的保肝作用.同时波棱瓜子总木脂素也可降低肝损伤小鼠血清NO水平和MPO、NOS活力,并减少肝组织匀浆中MDA的含量,增强SOD和GSH-Px活性,表现出良好的抗氧化作用;免疫组化结果显示,波棱瓜子总木脂素还能抑制诸如TNF-α、IFN-γ、IL-4、NF-κB等促炎症因子的表达,促进抗炎症因子IL-10的表达,从而抑制肝脏炎症反应而发挥其保肝作用.病理观察结果也表明,波棱瓜子总木脂素能减轻ConA对肝组织的损伤.结论:波棱瓜子总木脂素对ConA致小鼠免疫性肝损伤都具有一定的保护作用,其保肝作用可能与其抗炎、抗氧化能力有关.

ConA诱导小鼠肝损伤模型的发病机制

刀豆蛋白A(Con A)诱发的小鼠急性肝损伤是T淋巴细胞介导的肝损害模型之一,很好地模拟了人类病毒性肝炎、自身免疫性肝病等疾病。其特征是在很短时间内小鼠肝脏有大量中性粒细胞、巨噬细胞、T细胞等炎症性细胞浸润,同时血液中转氨酶水平大量升高。大量的促炎细胞因子(白介素4,肿瘤坏死因子α和γ-干扰素等)、趋化性因子(骨桥蛋白)、趋化因子受体(趋化因子受体5)参与了该模型的发病过程。此外,凋亡机制在该模型的肝脏损伤中也发挥了非常重要的作用。该文就这一肝损害模型的特点和发病机制的研究进展作综述。

激活素结合蛋白在ConA诱导小鼠肝损伤时的表达及作用

目的:探讨激活素结合蛋白(Follistatin,FS)在刀豆蛋白A(ConcanavalinA,Con A)诱导肝损伤中的表达及作用。方法:尾静脉注射ConA诱导小鼠急性肝损伤,实时定量PCR检测FSmRNA表达,ELISA法检测FS及激活素A(Activin A)蛋白水平。结果:注射ConA后肝脏组织中FSmRNA表达水平在第三天明显下降,FS蛋白水平在第三天也呈下降趋势;而Activin A水平明显增高。注射FS中和内源性激活素A作用后,肝脏病理损伤程度明显减轻,血清转氨酶水平也显著低于ConA单纯诱导组。结论:在ConA诱导的急性肝损伤过程中激活素A-FS系统失平衡,应用FS阻断内源激活素A可以减轻ConA诱导的肝脏损伤,因此FS有可能成为治疗肝损伤性疾病的有效药物。

荣肝合剂对ConA诱导急性免疫性肝损伤小鼠免疫调节及肝细胞凋亡相关因子的影响

目的探讨荣肝合剂对刀豆蛋白A(concanavalin A,ConA)介导的急性免疫性肝损伤小鼠免疫调节因子及细胞凋亡相关基因的影响。方法乙肝病毒(hepatitis B virus,HBV)转基因小鼠60只,随机分为6组,即空白组、模型组、荣肝合剂组、茵陈蒿汤组、茵陈组、联苯双酯组,每组10只。采用ConA尾静脉注射制备急性免疫性肝损伤模型。造模前14天,空白组、模型组给予生理盐水灌胃,其余各组分别给予:荣肝合剂、茵陈蒿汤、单味茵陈煎液、联苯双酯溶液,每日灌胃给药干预。末次灌胃给药后1 h,空白组给予磷酸盐缓冲液(PBS)尾静脉注射,其余各组按照ConA 3μg/g体重尾静脉注射造模。造模给药后8 h处死动物取血或组织标本检测丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、总胆红素(TBil)、肿瘤坏死因子α(TNF-α)、干扰素γ(INF-γ)、白介素-4(IL-4)、白介素-10(IL-10)及凋亡相关基因(Fas、FasL、Bax、bcl-2)等指标。结果模型组各指标与空白组比较,差异均有统计学意义(P<0.05,P<0.01)。与模型组比较,荣肝合剂组、联苯双酯组小鼠ALT、AST及荣肝合剂组TBil水平显著降低(P<0.01);荣肝合剂组小鼠肝组织TNF-α的水平降低(P<0.05),荣肝合剂组、茵陈蒿汤组小鼠肝组织IFN-γ的表达水平均降低(P<0.05),各干预药组小鼠肝组织IL-4的表达提高(P<0.05),荣肝合剂组小鼠肝组织IL-10的表达提高(P<0.05);荣肝合剂组、茵陈蒿汤组小鼠肝组织Fas的表达下降(P<0.05),荣肝合剂组小鼠肝组织FasL的表达下降(P<0.05),bcl-2基因的表达升高(P<0.05),荣肝合剂、茵陈组小鼠肝组织Bax基因的表达下调(P<0.05),荣肝合剂组bcl-2/Bax比值上调。同时,荣肝合剂组降低ALT、AST作用优于茵陈组(P<0.05);荣肝合剂组降低TNF-α表达水平优于联苯双酯、茵陈组(P<0.05);荣肝合剂组提高IL-10表达水平作用优于茵陈蒿汤组(P<0.01);荣肝合剂组降低Fas、FasL表达作用优于茵陈蒿汤、茵陈组及联苯双酯组(P<0.05);荣肝合剂组提高肝组织bcl-2基因的表达作用优于茵陈组(P<0.05)。结论荣肝合剂对ConA所致转基因小鼠急性免疫性肝损伤具有保护作用,其保护作用是通过改变Th1/Th2因子平衡(降低TNF-α、IFN-γ的表达,提高IL-10、IL-4表达)和调控肝细胞凋亡相关因子(下调Fas、FasL、Bax基因表达,上调bcl-2基因表达,上调bcl-2/Bax比值)实现的。

婴儿双歧杆菌对ConA诱导小鼠肝纤维化的影响

目的:研究婴儿双歧杆菌对刀豆蛋白A(ConA)诱导的小鼠肝纤维化的作用及其机制。方法:36只小鼠随机分为正常组、模型组和婴儿双歧杆菌组,每组12只。正常组静脉注射生理盐水,模型组和婴儿双歧杆菌组静脉注射12.5 mg/kg ConA溶液,每周1次。每日通过灌胃给予正常组和模型组蒸馏水,婴儿双歧杆菌组通过灌胃给予0.5 g/kg婴儿双歧杆菌溶液,持续7周。检测小鼠肝脏质量指数,小鼠血清肝功能生化指标(ALT、AST、ALB),透明质酸(HA),Ⅲ型前胶原肽(PCⅢ)的水平,以及小鼠肝组织Ⅰ型胶原(ColⅠ)、Ⅲ型胶原(ColⅢ)、基质金属蛋白酶抑制因子(TIMP)-1、基质蛋白金属酶(MMP)-1、MMP-2、MMP-9、肿瘤坏死因子α(TNF-α)、IL-6、IL-10的含量。结果:婴儿双歧杆菌能显著降低ConA诱导小鼠的肝脏质量指数(P<0.05),改善血清肝功能生化指标(P<0.05),降低血清HA、PCⅢ水平(P<0.05),降低肝组织中ColⅠ、ColⅢ、MMP-2、MMP-9、TIMP-1、TNF-α、IL-6含量(P<0.05),升高小鼠肝组织中MMP-1、IL-10含量(P<0.05)。结论:婴儿双歧杆菌具有明确的抗小鼠肝纤维化作用。

甘草酸铵通过抑制HMGB1的表达减轻ConA诱导的免疫性肝损伤

目的探讨甘草酸铵对刀豆蛋白A(Concanavalin A,ConA)诱导的免疫性肝损伤的保护作用及其可能的分子机制。方法在小鼠尾静脉注射ConA(20 mg/kg)前30 min,腹腔注射甘草酸铵(100 mg/kg)。ConA注射后8 h,检测血清转氨酶水平及肝组织学以评估肝损伤程度,应用酶联免疫法(ELISA)检测肝组织肿瘤坏死因子α(TNF-α)、干扰素γ(IFN-γ)、白介素-10(IL-10)水平。同时,分别采用实时荧光定量PCR和免疫组化检测肝组织高迁移率族蛋白-1(HMGB1)mRNA与蛋白的表达。结果预防性应用甘草酸铵有效地保护ConA诱导的小鼠免疫性肝损伤,表现为血清转氨酶水平与肝脏组织炎症坏死程度明显减轻;与ConA模型组相比,甘草酸铵对肝脏内的促炎症细胞因子TNF-α和IFN-γ并无影响,但增加了抗炎症因子IL-10水平(P<0.01);同时,甘草酸铵预防组肝组织HMBG1基因与蛋白的表达均明显低于模型组(P均<0.01)。结论甘草酸铵有效改善ConA诱导的小鼠免疫性肝损伤,其发挥作用的分子机制与抑制HMBG1表达有关。

不同刺激剂PHA和ConA对绒山羊淋巴细胞有丝分裂中期化的影响

试验旨在探索使较高比例的淋巴细胞富集在有丝分裂G2/M期的最佳条件。运用植物血凝素(PHA)和刀豆蛋白A(ConA)对淋巴细胞进行刺激使其增殖,培养一定时间后加秋水仙素对淋巴细胞进行同步化处理,用流式细胞仪检测G2/M期的细胞数量进行比对,观察试剂的最佳作用浓度和加秋水仙素的最佳时间。结果表明,采用PHA和ConA刺激淋巴细胞增殖的最佳作用浓度是60和5μg/mL,且淋巴细胞经ConA刺激培养45h再加秋水仙素处理5hG2期的比例最高为58.38%。结果提示,就绒山羊的淋巴细胞来说,ConA刺激绒山羊淋巴细胞增殖的效果比PHA好,且摸索出细胞G2/M期的时间点至关重要。

淫羊藿苷对ConA诱导的小鼠肝脏损伤保护机理的研究

目的:利用刀豆蛋白A(ConA)诱导建立小鼠肝炎模型,观察淫羊藿苷对该损伤模型保护作用的细胞免疫学和分子免疫学机制。方法:采用C57BL/6雄性小鼠,随机分为淫羊藿苷+ConA组、生理盐水+ConA组、淫羊藿苷+生理盐水组。小鼠尾静脉注射ConA,建立T细胞介导的免疫性肝脏损伤模型;采用转氨酶试剂盒测定各组小鼠血液中转氨酶含量;组织病理学观察实验小鼠肝脏组织和肝细胞坏死变化;采用ELISA试剂盒测定血清中炎性细胞因子IFN-γ、TNF-α含量;流式细胞术观察注射ConA后肝脏淋巴细胞的活化变化。结果:与ConA对照组相比,淫羊藿苷干预组小鼠血液中ALT和AST水平明显降低,P<0.01;IFN-γ、TNF-α含量明显降低,P<0.05;H&E染色可见淫羊藿苷干预组小鼠肝细胞核完整,未见炎性细胞的浸润,而ConA对照组小鼠肝细胞核固缩,部分核膜破裂,肝组织内有炎症细胞和红细胞浸润;流式细胞技术发现淫羊藿苷可明显延缓由ConA引起的肝脏NKT细胞的活化,减弱T细胞的浸润。结论:淫羊藿苷对ConA诱导的小鼠肝脏损伤有明显的保护作用,其机理可能与淫羊藿苷降低血液中IFN-γ、TNF-α表达及影响肝脏NKT细胞的活化有关。