田蓟苷对高脂饮食小鼠血脂代谢的改善作用及肠道菌群的影响

目的初步探讨田蓟苷改善高脂饮食小鼠血脂代谢的作用机制。方法将60只C57BL/6J小鼠随机分为对照组、高脂饮食组及田蓟苷低、中、高剂量给药组(50、100、200 mg/kg)和阿托伐他汀给药组(10 mg/kg),每组10只,连续给药12周后,检测各组小鼠血清总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL C)和低密度脂蛋白胆固醇(LDL C)水平。采用Western Blot法检测各组小鼠肝脏组织中SREBP 2和LDLR蛋白表达。通过16S rDNA基因实时荧光定量PCR法检测各组小鼠肠道菌群变化。结果与对照组相比,高脂饮食组小鼠血清TC、TG、HDL C和LDL C水平明显升高(t=-3.966,P=0.001;t=-3.438,P=0.003;t=3.811,P=0.001;t=-6.591,P<0.001),肝脏中SREBP 2和LDLR蛋白表达明显下调(t=7.198,P<0.001;t=8.892,P<0.001)。与高脂饮食组相比,田蓟苷高剂量给药组和阿托伐他汀给药组小鼠血清TC、LDL C水平明显降低(TC:t=2.483,P=0.023;t=3.300,P=0.004。LDL C:t=2.535,P=0.021;t=3.836,P=0.001),肝组织中的SREBP 2和LDLR蛋白水平明显上调(SREBP 2:t=-2.188,P=0.042;t=-3.317,P=0.007。LDLR:t=-2.649,P=0.016;t=-2.249,P=0.037)。与对照组相比,高脂饮食组小鼠肠道中厚壁菌门水平明显升高(t=-2.287,P=0.047),而拟杆菌门、双歧杆菌属、乳杆菌属、嗜黏蛋白阿克曼菌和普拉梭菌水平明显降低(t=3.127,P=0.006;t=2.737,P=0.014;t=3.542,P=0.002;t=3.491,P=0.003;t=2.780,P=0.012)。与高脂饮食组相比,田蓟苷高剂量给药组小鼠肠道中拟杆菌门、乳杆菌属和嗜黏蛋白阿克曼菌水平明显升高(t=-2.613,P=0.020;t=-2.558,P=0.024;t=-2.109,P=0.049)。结论田蓟苷改善高脂饮食诱导的血脂代谢紊乱可能与肝脏中SREBP 2和LDLR蛋白表达及肠道菌群结构变化有关,但其机制仍需进一步研究。     

二甲双胍调控肠道菌群并抑制结直肠癌的生长

目的探究二甲双胍抑制肠癌的生长及调控肠道菌群的作用。方法 20只C57BL/6J小鼠通过AOM-DSS诱导结直肠癌发生,分成2组每天分别灌胃生理盐水及二甲双胍溶液,12周后处死小鼠,收集结直肠组织及粪便,比较2组小鼠肠道肿瘤个数及大小并进行HE染色分析,运用16S rRNA基因测序技术检测小鼠肠道菌群组成,使用QIIME软件分析菌群物种分类、物种多样性指数及组间显著性差异。结果 2组小鼠体质量随周龄增加均呈现增长趋势,且实验结束时体质量差异无统计学意义(t=0.743 1,P=0.469 7)。与对照组相比,接受二甲双胍灌胃的实验组小鼠结直肠肿瘤数量减少(t=2.260 0,P=0.040 3)且尺寸偏小(t=2.570 0,P=0.014 4)。粪便菌群测序结果显示实验组小鼠肠道菌群丰富度增加(P0.05),而在多样性方面差异无统计学意义(P0.05)。在属水平上,实验组Akkermansia、Ruminococcus及ClostridiumⅩⅣa和Ⅳ等细菌的丰富度增加。结论二甲双胍能够调控肠道菌群的组成,增加肠道内产SCFAs细菌的定植,并抑制肠癌的发生发展。     

原发性肝癌H-ras12V小鼠 肠道微生态的初步研究

目的探索原发性肝癌小鼠(H-ras12V小鼠)肠道微生态的特异性。方法设立7月龄的H-ras12V小鼠为实验组,C57BL/6J常态小鼠为对照组。小鼠在标准饮食下饲养2个月。于实验第8周无菌收集小鼠粪便,进行V3-V4高可变区16SrDNA基因组测序,分析两组小鼠肠道菌群多样性和组成的差异。结果肝癌小鼠成瘤率为100%。α多样性:稀释曲线趋于平缓,样品测序数据量较合理。β多样性:通过Anosim分析确定两组组间差异显著大于组内差异(R=0.2857,P=0.0037)。菌群结构:门水平优势菌群有拟杆菌门、厚壁菌门、变形菌门等,属水平优势菌群有Barnesiella、Alloprevotella、拟杆菌属等。显著性差异物种:通过Kruskal-Wallis test分析,发现拟杆菌属等7个属差异有统计学意义(P0.05)。结论原发性肝癌H-ras12V小鼠肠道微生态多样性和菌群结构有显著差异,其中拟杆菌属及其特殊结构鞘脂与肝硬化及肿瘤关系密切,可能与肝癌存在联系。     

采用高通量测序技术 研究抗生素对小鼠肠道菌群的影响

目的探讨不同浓度抗生素对小鼠肠道菌群多样性和结构的影响,并预测相关功能变化。方法 15只SPF级ICR小鼠随机分为正常组、低浓度抗生素组和高浓度抗生素组,连续灌胃5 d后,采集小鼠新鲜粪便样本。利用Illumina MiSeq测序平台,对细菌的16S rRNA V3-V4区进行高通量测序,并对测序的结果进行生物信息学分析。结果高、低浓度抗生素组小鼠肠道菌群组成与正常组存在明显差异。与正常组相比,高剂量组小鼠肠道肠球菌属、志贺埃希菌属相对丰度显著升高(t=-2.71,P=0.026;t=-2.30,P0.05);分节丝状菌属、拟普雷沃菌属相对丰度显著降低(t=2.88,P=0.020;t=2.49,P=0.037),理研菌属极显著降低(t=3.79,P=0.005)。低剂量组小鼠肠道菌群变形菌纲成为优势菌,芽胞杆菌属、粪球菌_2、苏黎世杆菌属、普雷沃菌属_2、普雷沃菌属_7、志贺埃希菌属、沙雷菌属和放线菌属等相对丰度显著升高(均P0.05);梭杆菌属、泛菌属极显著升高(t=-3.19,P=0.013;t=-3.50,P=0.008);分节丝状菌属、理研菌属相对丰度显著降低(t=2.69,P=0.028;t=2.33,P=0.048)。PICRUSt功能预测分析显示,抗生素组显著增加人类疾病、细胞过程和环境信息处理功能层的基因拷贝数,显著降低有机系统、遗传信息处理和代谢功能层的基因拷贝数。结论广谱抗生素能破坏小鼠肠道的微生态平衡,有必要深入研究抗生素对心血管、免疫性、感染性及神经退行性疾病发展的潜在作用。     

肠道菌群及代谢与载脂蛋白E在动脉粥样硬化中的相互作用

目的明确肠道菌群及代谢与载脂蛋白在动脉粥样硬化中的相互作用。方法 C57BL/6J小鼠作为对照组(n=5),载脂蛋白E基因敲除(apolipoprotein E-deficient mice,ApoE~(-/-))小鼠作为动脉粥样硬化模型组(n=8),均为6周龄雄性。两组小鼠均给予高脂饮食,饲养12周后麻醉、摘眼球取血,采用全自动生化分析仪检测血脂,高效液相色谱串联质谱法测定血浆氧化三甲胺(Trimethylamine N-oxid,TMAO)的含量,留取粪便用于肠道菌群16S rRNA V3-V4区域的测序进行菌群鉴定,油红"O"染色主动脉根部确定动脉粥样硬化斑块面积。结果血清学指标:ApoE~(-/-)小鼠较对照组血浆中TMAO(t=-2.87,P0.05)、LDL(t=-11.76,P0.05)、TG(t=-3.56,P0.01)、TC(t=-12.38,P0.01)含量及动脉粥样硬化斑块面积(t=-11.94,P0.01)显著增加,HDL含量降低(t=3.63,P0.01)。肠道菌群测序:两组小鼠随着动脉斑块面积的增加,肠道微生物的丰富度、物种组成及功能预测分析等差异均有统计学意义,还发现ApoE~(-/-)小鼠能够生成TMAO的肠道菌群包括Anaeroplasma、Anaeroplasmatales、Anaeroplasmataceae、Proteus、Paraprevotella和Paraprevotellaceae,而对照组生成TMAO的菌群只有1类,为Anaerotruncus。结论 C57BL/6J小鼠与ApoE~(-/-)小鼠肠道微生物群落的组成、功能及其代谢产物TMAO的血浆含量各不相同,提示ApoE基因缺乏的宿主除导致脂质代谢紊乱外,在动脉粥样硬化形成过程中一定程度上影响着肠道菌群的代谢。     

藤三七类黄酮组分对小鼠代谢综合征模型及其肠道菌群的调节作用

目的探究类黄酮组分对小鼠代谢综合征模型及肠道菌群的调节作用。方法 SPF级雄性BALB/c小鼠分为对照组(NFD)、模型组(HFD)、类黄酮组(HFD+fla),每组6只。采用高脂饲料和高果糖建立代谢综合征模型,处理8周。类黄酮组用100mg/(kg·d)藤三七类黄酮灌胃。记录动物进食量和饮水量,测空腹血糖和体重。第8周处死动物,解剖获取肝脏和附睾脂肪组织。测定总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、甘油三酯(TG)和高密度脂蛋白胆固醇(HDL-C)含量。小鼠肝脏组织切片进行HE染色观察。取小鼠粪便,应用PCR-DGGE技术分析肠道菌群。结果模型组小鼠TC明显高于对照组(P=0.000),类黄酮组TC显著低于模型组(P=0.007)。模型组LDL-C显著高于对照组(P=0.031),类黄酮组LDL与模型组差异无统计学意义(P=0.072),但有降低趋势。肝脏脏器系数与脂肪系数组间比较差异无统计学意义(F=1.891,P=0.185),但类黄酮组与模型组相比,有降低趋势;模型组小鼠血清TG较对照组降低,组间比较差异有统计学意义(F=7.738,P=0.005)。模型组小鼠HDL较对照组升高,组间比较差异无统计学意义(F=3.621,P=0.052);肝脏病理学结果显示,类黄酮组肝细胞水肿得到了明显改善。模型组小鼠肠道菌群多样性和拟杆菌属细菌低于对照组;类黄酮组相比于模型组,肠道菌群多样性和拟杆菌属细菌有所恢复,嗜胆菌属细菌增加。结论藤三七类黄酮组分能促进肠道主要益生菌的生长,可以显著降低BALB/c小鼠TC水平,并有降低血清LDL-C的趋势。类黄酮明显改善小鼠肝细胞水肿,促进肠道菌群的恢复。     

链脲佐菌素诱导糖尿病大鼠模型肠道菌群变化

目的观察链脲佐菌素(streptozotocin,STZ)诱导糖尿病大鼠模型肠道菌群结构和丰度的变化。方法雄性SD大鼠25只,随机分为对照组(C)10只、模型组(M)15只。模型组腹腔注射3%的STZ,剂量30 mg/(kg·bw),连续5 d。成模后每月测量体重、血糖等指标。模型成立4周和12周时,分别在同一时间取各组大鼠的新鲜直肠粪便。在Illumina高通量测序平台上对粪便样本中细菌16S r DNA-V3区进行测序,对肠道菌群结构、丰度进行定量分析。结果模型组和对照组获得的优化序列数差异无显著性(P0.05)。模型组动物肠道菌群的相对丰度指数(Chao1)、多样性指数Shannon与对照组比较降低(P0.05),Simpson指数与对照组比较升高(P0.05)。在门水平,变形菌门(Proteobacteria)、蓝藻菌门(Cyanobacteria)、软壁菌门(Tenericutes)、TM7、放线菌门(Actinobacter)相对丰度降低(P0.05)。在属水平,造模4周,模型组乳杆菌属(Lactobacillus)相对丰度降低(P0.05);拟杆菌属(Bacteroides)相对丰度升高(P0.05)。造模12周,模型组乳杆菌属(Lactobacillus)、拟杆菌属(Bacteroides)、瘤胃球菌属(Ruminococcus)相对丰度升高(P0.05);双歧杆菌属(Bifidobacterium)相对丰度降低(P0.05)。结论 STZ诱导的SD大鼠糖尿病动物肠道菌群的丰度和多样性降低,为糖尿病与肠道菌群关系研究提供参考。     

老年类风湿关节炎患者血清25-羟维生素D_3水平与肠道微生态的关系探讨

目的探讨老年类风湿关节炎(RA)患者血清25-羟维生素D_3[25(OH)D_3]水平与肠道微生态的关系。方法回顾性分析2018年8月至2020年4月甘肃中医药大学附属医院风湿骨病科住院收治的83例老年RA患者的临床资料,并选择同期进行体检的80例健康者的体检资料,分别记为A组、B组。对比2组研究对象血清25(OH)D_3水平以及肠道微生物菌群组成;采用Pearson相关性分析,分析老年RA患者血清25(OH)D_3水平与肠道微生物菌群丰富度的相关性。结果 A组患者血清25(OH)D_3水平明显低于B组(t=23.297,P0.05);A组患者肠道微生物菌群Chaol指数、Observed species指数和Shannon指数均低于B组(t=11.258、14.681、22.157,均P0.05);A组患者肠道微生物菌群拟杆菌门、放线菌门、变形菌门、普雷沃菌属、梭状芽胞杆菌属、戈登菌属的相对丰度均高于B组(t=19.472、12.011、27.354、20.304、15.637、24.414,均P0.05),厚壁菌门、乳杆菌属、类杆菌属、嗜血杆菌属、韦荣球菌属、真杆菌属的相对丰度均低于B组(t=10.095、3.663、6.787、12.848、7.786、9.122,均P0.05);RA患者25(OH)D_3水平与厚壁菌门、乳杆菌属、类杆菌属、嗜血杆菌属、韦荣球菌属、真杆菌属的相对丰度呈正相关(r=8.126、8.031、8.415、8.057、8.236、8.467,均P0.05),与拟杆菌门、放线菌门、变形菌门、普雷沃菌属、梭状芽胞杆菌属、戈登菌属呈负相关(r=-7.639、-7.856、-8.135、-8.127、-7.536、-7.865,均P0.05)。结论 RA患者血清25(OH)D_3水平降低,肠道微生物菌群拟杆菌门、放线菌门、变形菌门、普雷沃菌属、梭状芽胞杆菌属、戈登菌属的相对丰度增加,厚壁菌门、乳杆菌属、类杆菌属、嗜血杆菌属、韦荣球菌属、真杆菌属的相对丰度减少,老年RA患者血清25(OH)D_3水平与肠道微生物菌群分布相关。     

链球菌与香菇多糖联用对PM_(2.5)暴露肺癌小鼠呼吸道菌群的影响CSCD

目的观察潜在益生菌链球菌C17、D19株与香菇多糖联合应用对PM_(2.5)暴露肺癌荷瘤小鼠呼吸道菌群多样性的影响。方法尾静脉注射A549细胞悬液构建荷瘤SCID小鼠模型,气管滴注40μL 20mg/mL的PM_(2.5)溶液,每周1次,持续4周。实验组(LS组)给予链球菌C17、D19株混合菌液喷雾给药,每周2次,同时腹腔注射3mg/kg香菇多糖。对照组(PM组)仅喷雾生理盐水。比较组(LE组)喷雾生理盐水同时给予香菇多糖。全部小鼠均持续处理4周。利用高通量测序对咽拭子样本中的菌群进行16SrDNA序列检测,进行OTU统计、物种组成分析、指示物种分析、Alpha多样性分析、Beta多样性分析。结果PM组小鼠OTU数量大于LE组、LS组。各组主要优势菌为厚壁菌门、变形菌门、放线菌门、蓝细菌门、拟杆菌门。与PM组比较,LE组(t=3.2064,P=0.0071)、LS组(t=3.4061,P=0.0098)放线菌门丰度增加显著,LE组蓝细菌门丰度减少显著(t=2.7316,P=0.0340)。属水平上,LS组与LE组各优势菌属总丰度显著高于PM组。与PM组比较,LS组小鼠呼吸道嗜气杆菌属(t=7.1686,P=0.0008)和普雷沃菌属(t=2.2702,P=0.0230)丰度显著增加,LE组嗜气杆菌属(t=2.5238,P=0.0429)、加德纳菌属(t=2.4720,P=0.0445)、奇异菌属(t=4.8123,P=0.0030)、弧菌属(t=2.4597,P=0.0210)、普雷沃菌属(t=2.6076,P=0.0319)丰度差异显著。种水平上,与PM组比较,LS组小鼠呼吸道酸性链球菌(t=2.4456,P=0.0450)、Rodentibacter_heylii(t=7.1686,P=0.0008)增加显著,LE组普雷沃菌(t=2.2751,P=0.0462)、Rodentibacter_heylii(t=2.5238,P=0.0340)增加显著。Alpha多样性分析显示,LE组与PM组间、LS组与PM组间菌群Chao指数(t=2.3867,P=0.0388;t=5.8780,P=0.0006),Ace指数(t=2.8267,P=0.0192;t=6.1316,P=0.0009)差异有统计学意义。Beta多样性分析显示,LS组与PM组间(t=2.9994,P=0.0056)、LE组与PM组间(t=4.8938,P<0.0001)OTU水平比较差异有统计学意义。结论潜在益生菌C17、D19株与香菇多糖联合应用可调节PM_(2.5)暴露肺癌小鼠呼吸道的菌群多样性。     

低聚果糖对慢性应激小鼠抑郁样行为及 肠道菌群的影响

目的探讨低聚果糖(FOS)对慢性应激小鼠的抑郁样行为及肠道菌群的影响。方法选取8周龄健康雄性ICR小鼠随机分成3组,C组小鼠每天给予正常护理,S组和SF组小鼠每天随机给予1～2种应激源,持续8周,SF组小鼠在应激造模的同时经食物补充FOS。在造模4周和8周后,分别通过强迫游泳、蔗糖偏好试验评估各组小鼠抑郁样行为。造模结束后通过Western blot试验检测小鼠大脑皮层内糖皮质激素受体(GR)的表达,并收集结肠内容物进行16SrDNA扩增子测序分析。结果应激造模8周后,C、S和SF三组小鼠的肠道菌群组成存在明显差异;与C组相比,S组小鼠强迫游泳的不动时间显著增加(t=3.970,P=0.0009),蔗糖偏好率显著降低(t=3.890,P=0.0011),脑内GR的表达显著降低(t=4.311,P=0.0125);与S组相比,SF组小鼠强迫游泳的不动时间显著缩短(t=3.495,P=0.0026),蔗糖偏好率和脑内GR表达有增加趋势。结论益生元FOS可调节肠道菌群,改善慢性应激诱发的精神情绪异常。     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.