基于Bcl-2/CytC探究槲皮素对肝硬化大鼠微循环及肝脏病变的影响

摘要 目的：基于Bcl-2/CytC调控网络探讨槲皮素对肝硬化大鼠微循环及肝脏病变的影响。方法：选取清洁级SD大鼠45 只,随机数字表法分为A组、LC组、QUE low group、QUE high group,ETV组,10 只/组,除10只健康大鼠外其余均建立肝硬化模型,QUE low group采用槲皮素50 mg/kg灌胃,QUE high group采用槲皮素100 mg/kg灌胃,ETV组采用恩替卡韦分散片0.5 mg/次灌胃,A组与LC组均用生理盐水灌胃,均1 次/d,共计14 d。采用ELISA检测大鼠血清中丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST)、总胆固醇（TC）、甘油三酯（TG）水平及血栓素A2（TXA2）、血管紧张素II（AngⅡ）、前列环素（PGI2）含量,HE染色比较各组肝组织形态,免疫印迹检测大鼠肝组织中Bcl-2、Bax、细胞色素C(CytC)蛋白表达。结果：与A group相比,LC group的ALT、AST、TC、TG、TXA2、AngII表达均较高,PGI2、CytC、Bax较低（P<0.05）;与LC组比较,QUE low group的ALT、AST、TC、TG、TXA2、AngII均降低,PGI2、CytC、Bax升高（P<0.05）;与QUE low group比较,ETV group的ALT、AST、TC、TG、TXA2、AngII均降低,PGI2、CytC、Bax升高（P<0.05）;与ETV group比较,QUE high group的ALT、AST、TC、TG、TXA2、AngII均降低,PGI2、CytC、Bax升高（P<0.05）。A组大鼠肝脏组织完好;LC group大鼠肝组织损伤严重;QUE low group大鼠肝间质仍有纤维组织增生及炎症浸润现象;ETV组仍有肝细胞变性及炎性因子;QUE high group大鼠肝组织变性反应及汇管区炎症降低。与A group比较,LC group有明显肝纤维化、肝细胞变性坏死及炎细胞浸润（P＜0.05）;与LC group比较,QUE low group大鼠肝脏纤维化等有所缓解（P＜0.05）;与QUE low group比较,ETV group大鼠肝脏纤维化、变性坏死及炎细胞浸润缓解（P＜0.05）;与ETV group比较,QUE high group大鼠肝脏纤维化、变性坏死及炎细胞浸润改善（P＜0.05）。结论：槲皮素对肝硬化大鼠的肝组织具有一定保护作用,改善肝功能和肝脏微循环、肝脏病变,其机制可能调节Bcl-2、Bax和CytC等相关蛋白有关。     

小檗碱对肝硬化大鼠肠粘膜及肝脏保护作用的研究

目的:观察小檗碱对肝硬化大鼠肝脏和肠粘膜屏障的保护作用。方法:24只Wistar大鼠随机分为小檗碱干预组、肝硬化造模组、正常对照组。小檗碱干预组和肝硬化造模组予以四氯化碳联合酒精进行肝硬化造模。小檗碱干预组造模同时予以小檗碱灌胃,观察大鼠的一般情况、进食量、体重,第8周末处死全部大鼠,检测血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、内毒素(ET)水平,并取肝组织和回肠进行病理检查。结果:肝硬化造模组大鼠和小檗碱干预组大鼠进食量及体重有下降,肝硬化造模组下降大于小檗碱干预组,差别有统计学意义P 0.01。小檗碱干预组ALT,AST,ET水平均低于肝硬化造模组,差别有统计学意义P 0.01。肝脏病理观察:小檗碱干预组肝小叶结构破坏,假小叶形成,汇管区及小叶内炎症细胞浸润方面明显轻于肝硬化造模组。回盲部病理观察:小檗碱干预组的小肠绒毛缩短、变形、数量减少,上皮细胞排列紊乱方面轻于肝硬化造模组。结论:小檗碱对四氯化碳联合酒精所致的肝硬化大鼠有减轻肝损伤和保护肠粘膜的作用。     

布拉酵母菌散对肝硬化大鼠肠黏膜屏障保护作用的实验研究

目的研究布拉酵母菌散对肝硬化大鼠肠黏膜屏障的保护作用及其可能机制。方法采用皮下注射40%CCL4橄榄油溶液+10%酒精饮料诱导肝硬化模型。造模成功后,治疗组用布拉酵母菌灌胃[75×108CFU/(kg·d)],对照组、模型组给予等容量的生理盐水灌胃,连续14 d。采用鲎试剂终点显色法检测血浆内毒素水平,应用分光光度法测定小肠组织二胺氧化酶(DAO)活性,应用自动生化分析仪检测血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)变化。结果模型组血浆内毒素水平[(0.251±0.011)EU/m L]较治疗组[(0.168±0.012)EU/m L]明显升高,差异有统计学意义(P0.01);模型组肠组织DAO活性为(0.432±0.074)U/mg,明显较对照组[(0.728±0.065)U/mg]降低,差异有统计学意义(P0.01),治疗组DAO活性为(0.548±0.053)U/mg,与模型组相比较,肠DAO活性升高,差异有统计学意义(P0.01),模型组、治疗组肠组织DAO活性较对照组明显降低(P0.01);模型组血清ALT、AST含量分别为(133.89±8.09)U/m L、(176.92±10.94)U/m L,比对照组ALT、AST含量[(36.73±6.95)U/m L、(41.35±10.07)U/m L]明显升高,P0.01;治疗组[(95.76±7.27)U/m L、(158.02±5.94)U/m L]与模型组相比较,ALT、AST含量下降,差异有统计学意义(P0.01)。结论肝硬化大鼠存在肠黏膜屏障受损,布拉酵母菌可通过调整肠道菌群,改善肠源性内毒素血症,对肠黏膜屏障起到保护作用,可作为慢性肝病的辅助治疗。     

R.hominis对肝硬化大鼠肝功能、血清细胞因子和肝肠组织的影响

目的探讨Roseburia hominis对肝硬化大鼠肝功能、血清细胞因子及肝脏、肠道组织的影响。方法 30只体质量250～300 g的雄性大鼠,随机分为3组:RH组10只、正常对照组10只,模型对照组10只,正常对照组给予生理盐水腹腔注射,其余20只大鼠均用四氯化碳制备肝硬化大鼠模型。模型制备后,在处死大鼠之前15天开始,RH组大鼠给予R.hominis活菌菌液灌胃,模型对照组给予等量生理盐水灌胃,采集样本测定。观察肝功能及血清细胞因子;对肝脏和肠道组织行石蜡包埋、切片、苏木精和伊红染色,病理切片观察对比组织的炎症和损伤程度。结果 RH组大鼠肝功能显著好转,ALT、AST、TB与模型组对比均显著下降(t=2.633 1、2.701 2、2.581 4,P=0.011 5、0.008 9、0.013 3)。血清细胞因子的检测结果显示,与模型对照组相比,RH组大鼠IFN-γ和IL-10的水平均显著升高(t=2.256 2、2.001 2,P=0.025 8、0.041 6)。RH组大鼠肝脏、肠道组织病理结果较模型对照组明显好转。结论 R.hominis对肝硬化大鼠肝功能有改善作用,可减轻肝脏及肠道组织损伤,提高血清中IFN-γ和IL-10水平。     

布拉酵母菌对大鼠非酒精性脂肪性肝炎的疗效

目的探讨布拉酵母菌在高脂饮食诱导的非酒精性脂肪性肝炎(NASH)大鼠模型中的疗效及机制。方法 36只雄性SD大鼠随机分为3组:A组(普通饲料组)、B组(高脂饲料组)和C组(高脂饲料+布拉酵母菌组)。实验第6周起,C组给予布拉酵母菌散10 mg/kg灌胃。第16周末进行肝脏病理分析和血清空腹ALT、AST、脂多糖(LPS)、肿瘤坏死因子-α(TNF-α)、脂联素以及丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性测定;检测粪便中双歧杆菌、乳杆菌、肠球菌和大肠埃希菌数量,分析菌群与LPS相关性。结果与A组相比,模型B组肝脏脂肪变性程度和肝脏炎症显著增加,粪便菌群发生紊乱;与B组相比,C组脂肪变性及炎症程度积分显著减轻,血清ALT、AST、LPS、TNF-α及MDA显著下降,脂联素水平和SOD活性增高,大鼠粪便中乳杆菌、双歧杆菌和肠球菌数量明显增高,大肠埃希菌显著降低;乳杆菌、双歧杆菌和肠球菌与LPS负相关,大肠埃希菌与LPS正相关。结论布拉酵母菌可通过调整肠道菌群结构,减少炎性因子释放,拮抗脂质过氧化,改善肝脏脂肪变性及炎症。     

双歧三联活菌胶囊辅助治疗对乙肝后肝硬化患者肠黏膜屏障功能及细胞免疫功能的影响

目的探讨双歧三联活菌胶囊辅助治疗对乙肝后肝硬化患者肠黏膜屏障功能及细胞免疫功能的影响。方法选取78例门诊或住院治疗的乙肝后肝硬化患者,随机分为两组,其中观察组和对照组各39例。两组患者予以护肝利尿、控制门脉压和营养支持等基础治疗。观察组加用双歧三联活菌胶囊630mg/次,2次/d,温水口服,连用6周。观察两组治疗前后肝功能指标[丙氨酸转氨酶(ALT)、天门冬氨酸转氨酶(AST)和总胆红素(TBIL)]、肠黏膜屏障功能[前降钙素(PCT)和二胺氧化酶(DAO)]及细胞免疫功能[T淋巴细胞亚群]的变化。结果治疗6周后,两组血清ALT、AST和TBIL指标较前均明显下降(P0.05或P0.01),且观察组下降幅度较对照组更明显(P0.05);两组血清PCT和DAO指标较前明显下降(P0.05或P0.01),且观察组下降幅度较对照组更明显(P0.05);同时两组CD4+水平和CD4+/CD8+比值均较前明显上升(P0.05),且观察组上升幅度较对照组更明显(P0.05),而两组治疗前后CD8+水平无明显变化(P0.05)。结论双歧三联活菌胶囊辅助治疗乙肝后肝硬化患者能更有效降低ALT、AST和TBIL水平,保护其肝功能;降低血清PCT和DAO水平,修复肠黏膜屏障功能;还能纠正T淋巴细胞亚群紊乱,增加其细胞免疫功能。     

双歧杆菌四联活菌片联合谷氨酰胺对酒精性肝硬化患者肠黏膜屏障功能的保护作用

目的探讨双歧杆菌四联活菌片联合谷氨酰胺对酒精性肝硬化患者肠黏膜屏障功能的保护作用。方法选择酒精性肝硬化患者90例,分为观察组和对照组。两组均常规予以对症支持治疗,观察组加用双歧杆菌四联活菌片联合谷氨酰胺治疗,对照组加用单纯双歧杆菌四联活菌片。其中双歧杆菌四联活菌片口服,1.5g/次,3次/d;谷氨酰胺颗粒口服,1.0g/次,3次/d,两组连用8周。观察并比较两组患者治疗前后肝功能指标:丙氨酸转氨酶(ALT)、天门冬氨酸转氨酶(AST)、血总胆红素(TB)和肠黏膜屏障功能指标(血浆二胺氧化酶、降钙素原和尿乳果糖/甘露醇比值)的变化。结果观察组与对照组治疗期间分别失访4例与7例,两组失访率比较差异无统计学意义(χ2=0.79,P0.05)。治疗8周后,两组ALT、AST和TB水平均较前明显下降(P0.05或P0.01),且观察组下降幅度明显高于对照组(P0.05)。同时两组血浆二胺氧化酶、降钙素原和尿乳果糖/甘露醇比值均较前明显下降(P0.05或P0.01),且观察组下降幅度明显高于对照组(P0.05)。结论双歧杆菌四联活菌片联合谷氨酰胺对酒精性肝硬化患者肠黏膜屏障功能的保护作用明显优于单纯的双歧杆菌四联活菌片,能加速肝功能恢复,加速肠黏膜通透性的修复,保护与改善肠黏膜屏障功能,具有辅助治疗酒精性肝硬化的作用。     

双歧杆菌三联活菌肠溶胶囊对高脂饮食所致大鼠非酒精性脂肪肝的疗效及机制探讨

目的 观察微生态制剂贝飞达(双歧杆菌三联活菌肠溶胶囊)治疗高脂饮食所致大鼠非酒精性脂肪肝的疗效并探讨其可能的作用机制.方法 雄性SD大鼠32只,适应性饲养1周后,随机分为3组,正常组:12只给予普通饲料喂养;模型组:12只,贝飞达治疗组:8只,均给予高脂饲料喂养;于喂养12周末正常组及模型组各处死4只,经肝组织HE染色确定造模成功后,贝飞达治疗组给予贝飞达[0.113 g/(kg·d)]灌胃,于16周末全部处死.检测大鼠血清AST、ALT、TC、TG、LDL、HDL、血清内毒素水平,观察其肝组织学变化.结果 模型组于高脂饲料喂养12周末出现脂肪肝,与正常组比较,模型组大鼠血清AST、ALT、TG、TC、LDL、HDL及血清内毒素水平均明显升高(P＜0.01).贝飞达治疗组大鼠各项指标较模型组均有显著改善,肝脏脂肪变性程度减轻.结论 微生态制剂贝飞达可能通过改善肠道菌群紊乱,减轻内毒素血症,从而调节肝脏脂质代谢紊乱,对非酒精性单纯性脂肪肝起到治疗作用.     

粪菌移植对小鼠实验性结肠炎TLR4信号通路及肠黏膜屏障的影响

目的探讨粪菌移植(FMT)对溃疡性结肠炎(UC)小鼠肠黏膜屏障的影响及可能机制。方法小鼠饮用2.0%葡聚糖硫酸钠(DSS)溶液构建小鼠UC模型;50只成年雄性C57BL/6J小鼠,随机留取10只取粪便(这10只不参与后续的实验),其余40只称重、编号,随机分为空白对照组(Con组)、DSS模型对照组(Model组)、美沙拉嗪组(Model+5-ASA组)和粪菌液组(Model+FMT组),每组10只,Con组和Model组均给予0.9%NaCl溶液灌肠,给药组分别给予美沙拉嗪、粪便滤液灌肠;评估疾病活动指数(DAI)、各组结肠组织病理情况,用透射电镜检测各组小鼠的结肠黏膜上皮细胞结构的变化情况,ELISA检测各组血清内毒素、炎症因子TNF-α水平变化,免疫组化法检测结肠组织Toll样受体4(TLR4)及核因子-κB(NF-κB)的表达变化,Western blot检测各组ZO-1蛋白表达。结果与Model组相比,粪菌移植明显改善小鼠的DAI指数和结肠组织的病理损伤,结肠上皮细胞间隙增宽程度减轻,腺上皮细胞间连接较紧密,结肠黏膜上皮细胞微绒毛完整,排列整齐,内毒素、TNF-α的含量明显下降,TLR4及NF-κB在结肠组织的表达明显下降,ZO-1蛋白表达明显升高,促进结肠黏膜屏障的修复,差异具有统计学意义(t=7.9543,P<0.0001;t=3.7641,P=0.0010;t=4.5899,P=0.0020;t=13.2886,P<0.0001;t=4.9750,P=0.0010;t=6.9388,P<0.0001;t=8.3744,P<0.0001)。结论FMT可减少内毒素及炎症因子的产生,改善结肠炎症,TLR4-NF-κB信号通路可能是FMT修复结肠黏膜屏障功能的机制之一。     

黑果枸杞汁对大鼠酒精性肝损伤的保护作用*

目的: 研究黑果枸杞汁对大鼠酒精性肝损伤的保护作用,探讨其中Toll样受体4(TLR4)/p38 丝裂原活化蛋白激酶(p38 MAPK)信号通路的调节机制。方法: 60只雄性SD大鼠随机分为空白对照组(C)、模型组(M)、低剂量黑果枸杞汁组(LLM)、中剂量黑果枸杞汁组(MLM)、高剂量黑果枸杞汁组(HLM),每组12只。M、LLM、MLM和HLM组每天以20 ml/kg(8 g/(kg·d))剂量分2次灌胃400 g/L酒精,C组于相同时间点灌胃等体积蒸馏水。每日首次酒精灌胃前4 h,黑果枸杞汁各剂量组分别以2.4、4.8、9.6 ml/(kg·d)进行灌胃,其他组于相同时间点灌胃等体积蒸馏水。实验周期4周,末次实验结束后24 h处死大鼠,取血液和肝脏,计算肝脏指数,HE染色观察肝脏组织形态,比色法检测血清谷丙转氨酶(ALT)、谷草转氨酶(AST)活性,免疫组化法检测肝脏TLR4、p38 MAPK及磷酸化p38 MAPK(p-p38 MAPK)蛋白质表达,酶联免疫吸附试验检测肝脏肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-10(IL-10)、白细胞介素-18(IL-18)水平。结果: 与C组比较,M组成功建立酒精性肝损伤模型。与M组比较,黑果枸杞汁各剂量组的相关指标出现改善,其中HLM组肝脏组织形态改善最为显著,其肝脏系数、血清ALT和AST、肝脏TLR4蛋白质表达、p-p38 MAPK/p38 MAPK比值、TNF-α、IL-1β和IL-18水平均显著降低(P＜0.05或P＜0.01),肝脏IL-10水平显著升高(P＜0.01)。黑果枸杞汁各剂量组组间比较,肝脏系数、血清AST、肝脏TLR4蛋白质表达、p-p38 MAPK/p38 MAPK比值、TNF-α和IL-18水平,HLM组较LLM组均显著降低(P＜0.05或P＜0.01);肝脏IL-10水平,HLM组较LLM和MLM组均显著升高(P＜0.05或P＜0.01);其余主要指标组间比较均无统计学差异(P＞0.05)。结论: 黑果枸杞汁可以通过调控TLR4/p38 MAPK信号通路,改善炎症应激,缓解大鼠酒精性肝损伤,高剂量组效果优于其他剂量组。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.