Farnesol作用变异链球菌脱矿的实验研究

目的 Farnesol(法尼醇)作为密度感应分子,具有影响变异链球菌生物膜代谢以及介导肿瘤细胞凋亡的作用。文中研究Farnesol对变异链球菌脱矿的影响。方法将变异链球菌UA159菌悬液接种于放置牙釉质切片的培养皿中,分为5组,即变链+0μmol/L Farnesol组、变链+50μmol/L Farnesol组、变链+100μmol/L Farnesol组、变链+200μmol/L Farnesol组和对照组。对照组中加入无菌去离子水。采用扫描电镜观察釉质表面的变异链球菌生物膜,显微硬度仪检测实验前后釉质表面显微硬度(surface microhardness,SMH),并用粗糙度仪测定釉面粗糙度。结果随着Farnesol浓度的递增,变异链球菌生物膜生长受抑制,釉质表面粗糙度减少,釉质显微硬度的下降幅度减小,当Farnesol浓度为200μmol/L时釉质显微硬度值[(270.87±12.19)N/mm2]较[变链+50μmol/L Farnesol组、变链+100μmol/L Farnesol组、变链+0μmol/L Farnesol组的(224.63±18.98)、(228.06±10.40)、(198.57±8.19)N/mm2]明显升高(P<0.01),各实验组的SMH较对照组[(368.60±7.33)N/mm2]低,差异有统计学意义(P<0.05)。结论 Farnesol可抑制变异链球菌对牙釉质的脱矿作用。

Farnesol对变形链球菌脱矿作用的体外研究

目的研究Farnesol(法尼醇)对变形链球菌脱矿作用的影响。方法 BHI培养变形链球菌,将常规预备好的牙釉质切片放置于菌悬液中。实验组分别加入浓度为0、50、100、200μmol/L的Farnesol,对照组中加入无菌去离子水。采用原子吸收分光光度法检测不同时间点(24、48及72 h)菌悬液中钙离子的浓度。结果随着Farnesol浓度的递增,菌悬液中钙离子浓度逐渐降低,当Farnesol浓度为200μmol/L时菌悬液中钙离子的浓度与其余3组相比有显著性差异,实验组与对照组相比也有显著性差异(P<0.05)。结论 Farnesol可抑制变形链球菌对牙釉质的脱矿作用。

Farnesol对白假丝酵母菌细胞生长及活性的干扰作用

目的:评价Farnesol对白假丝酵母菌生长、细胞活性及形态的干扰作用;检测氟康唑、克霉唑、制霉菌素、特比萘酚、卡泊芬净在不同浓度Farnesol条件下对白假丝酵母菌的抗菌活性。方法:通过吸光浊度测定不同浓度组Farnesol对白假丝酵母菌生长作用的影响;采用MTT法检测Farnesol对白假丝酵母菌细胞活性的干扰作用;光镜及电镜扫描观察不同浓度组Farnesol作用下,白假丝酵母菌细胞形态改变;测定不同种类抗真菌药物在不同浓度组Farnesol条件下对白假丝酵母菌的抗菌活性。结果:Farnesol对白假丝酵母菌的生长及细胞活性具有抑制作用。低浓度Farnesol即可抑制假丝酵母菌菌丝的形成,随着Farnesol浓度的升高,菌株以孢子相存在且生长受到抑制;高浓度组Farnesol并不能完全抑制菌株生长。Farnesol对抗真菌药物的抗菌活性具有干扰作用,低浓度Farnesol环境可以改善氟康唑的"拖尾"现象。结论:Farnesol对白假丝酵母菌生长及细胞活性具有浓度依赖性的抑制作用。Farnesol抑制白假丝酵母菌菌丝形成,可干扰抗真菌药物的活性,低浓度改善氟康唑的"拖尾"现象。

Influences of trans-trans farnesol,a membrane-targeting sesquiterpenoid,on Streptococcus mutans physiology and survival within mixed-species oral biofilms

Trans-trans farnesol （tt-farnesol） is a bioactive sesquiterpene alcohol commonly found in propolis （a beehive product） and citrus fruits, which disrupts the ability of Streptococcus mutans （S. mutans） to form virulent biofilms. In this study, we investigated whether tt-farnesol affects cell-membrane function, acid production and/or acid tolerance by planktonic cells and biofilms of S. mutans UA159. Furthermore, the influence of the agent on S. mutans gene expression and ability to form biofilms in the presence of other oral bacteria （Streptococcus oralis （S. oralis） 35037 and Actinomyces naeslundii （.4. naeslundil） 12104） was also examined. In general, tt-farnesol （1 mmol-L-1） significantly increased the membrane proton permeability and reduced glycolytie activity of S. mutans in the planktonic state and in biofilms （P〈0.05）. Moreover, topical applications of 1 mmol-L＂l tt-farnesol twice daily （1 min exposure/treatment） reduced biomass accumulation and prevented ecological shifts towards S. mutans dominance within mixed-species biofilms after introduction of 1% sucrose. S. oralis （a non-cariogenie organism） became the major species after treatments with tt-farnesol, whereas vehicle-treated biofilms contained mostly S. mutans （〉90% of total bacterial population）. However, the agent did not affect significantly the expression of S. mutans genes involved in acidogenicity, acid tolerance or polysaccharide synthesis in the treated biofilms. Our data indicate that tt-farnesoi may affect the competi- tiveness of S. mutans in a mixed-species environment by primarily disrupting the membrane function and physiology of this bacterium. This naturally occurring terpenoid could be a potentially useful adjunctive agent to the current anti-biofilm/anti-caries chemotherapeutic strategies.

真菌密度感应分子 Farnesol 在表皮葡萄球菌和白假丝酵母菌混合生物膜形成中的作用

目的探讨真菌密度感应分子Farnesol在表皮葡萄球菌和白假丝酵母菌混合生物膜形成中的作用。方法将表皮葡萄球菌标准株ATCC35984及白假丝酵母菌标准株ATCC10231混合培养建立体外生物膜模型,加入Farnesol或不加入Farnesol分为Farnesol处理组和对照组,孵育2、4、6、8、12、24、48、72、96h时用结晶紫染色法半定量检测生物膜形成能力;二甲氧唑黄(XTT)比色法评价生物膜的体外生长动力学;扫描电子显微镜观察生物膜超微结构;荧光定量PCR分析各组生物膜形成相关基因的表达情况。结果结晶紫染色法生物膜半定量检测显示,12、24hFarnesol处理组和对照组差异有统计学意义(P<0.05)。XTT比色法生长动力学检测显示,Farnesol处理组在4、48h与对照组比较,差异有统计学意义(P<0.05)。扫描电镜结果显示,对照组混合生物膜结构较Farnesol处理组致密复杂。荧光定量PCR结果显示,培养6hFarnesol处理组表皮葡萄球菌生物膜形成相关基因icaA、fbe、aap基因及白假丝酵母菌生物膜形成相关基因als3、hwp1、efg1基因的表达下调;培养24hFarnesol处理组表皮葡萄球菌生物膜形成相关基因aap基因及白假丝酵母菌生物膜形成相关基因als3、hwp1、efg1基因的表达下调。结论在真菌密度感应分子Farnesol的干预下,对照组形成的混合生物膜较Farnesol处理组结构更为致密及复杂,这种结构的改变可能与Farnesol处理组白假丝酵母菌生物膜形成相关基因als3、hwp1、efg1基因的表达下调相关性更密切。

内源性Farnesol对变异链球菌脱矿作用的研究

目的观察内源性Farnesol处理变异链球菌后牙釉质脱矿的变化。方法放置牙釉质切片于培养皿中,实验分5组,前3组加入变异链球菌菌悬液的同时分别添加去离子水、白色念珠菌24 h上清、白色念珠菌菌悬液,第4组加入白色念珠菌菌悬液,去离子水组为空白对照组。采用原子吸收分光光度法检测不同时间点(24、48、72 h)菌悬液中钙离子的浓度。结果加入白色念珠菌24 h上清组在24、48、72 h分别测得钙离子的浓度为(80.26±1.63)、(81.14±1.24)、(78.31±0.76)μg/mL,明显低于其它变异链球菌组,与对照组相比也有显著性差异(P<0.05)。变异链球菌作用牙釉质的脱矿过程受到白色念珠菌分泌的Farnesol的调控,其脱矿作用受到明显的抑制。结论内源性Farnesol可抑制变异链球菌对牙釉质的脱矿作用。

Two farnesyl pyrophosphate synthases,GhFPS1–2,in Gossypium hirsutum are involved in the biosynthesis of farnesol to attract parasitoid wasps

Sesquiterpenoids play an import role in the direct or indirect defense of plants.Farnesyl pyrophosphate synthases(FPSs)catalyze the biosynthesis of farnesyl pyrophosphate,which is a key precursor of farnesol and(E)-β-farnesene.In the current study,two FPS genes in Gossypium hirsutum,GhFPS1 and GhFPS2,were heterologously cloned and functionally characterized in a greenhouse setting.The open reading frames for full-length GhFPS1 and GhFPS2 were each 1029 nucleotides,and encoded two proteins of 342 amino acids with molecular weights of 39.4 kDa.The deduced amino acid sequences of GhFPS1–2 showed high identity to FPSs of other plants.Quantitative real-time PCR analysis revealed that GhFPS1 and GhFPS2 were highly expressed in G.hirsutum leaves,and were upregulated in methyl jasmonate(MeJA)-,methyl salicylate(MeSA)-and aphid infestation-treated cotton plants.The recombinant proteins of either GhFPS1 or GhFPS2 plus calf intestinal alkaline phosphatase could convert geranyl diphosphate(GPP)or isopentenyl diphosphate(IPP)to one major product,farnesol.Moreover,in electrophysiological response and Y-tube olfactometer assays,farnesol showed obvious attractiveness to female Aphidius gifuensis,which is an important parasitic wasp of aphids.Our findings suggest that two GhFPSs are involved in farnesol biosynthesis and they play a crucial role in indirect defense of cotton against aphid infestation.

Farnesol inhibits development of caries by augmenting oxygen sensitivity and suppressing virulence-associated gene expression in Streptococcus mutans

Streptococcus mutans is a primary etiological agent of dental caries.Farnesol,as a potential antimicrobial agent,inhibits the development of S.mutans biofilm.In this study,we hypothesized that farnesol inhibits caries development in vitro and interferes with biofilm fonnation by regulating virulence-associated gene expression.The inhibitory effects of farnesol to S.mutans biofilms on enamel surfaces were investigated by determining micro-hardness and calcium measurements.Additionally,the morphological changes of S.mutans biofilms were compared using field emission scanning electron microscopy and confocal laser scanning microscopy,and the vitality and oxygen sensitivity of S.mutans biofilms were compared using MTT assays.To investigate the molecular mechanisms of farnesol＇s effects,expressions of possible target genes luxS,brpA,ffh,recA,nth,and smx were analyzed using reverse-transcription polymerase chain reaction（PCR） and quantitative PCR.Farnesol-treated groups exhibited significantly higher micro-hardness on the enamel surface and lower calcium concentration of the supernatants as compared to the-untreated control.Microscopy revealed that a thinner film with less extracellular matrix formed in the farnesol-treated groups.As compared to the-untreated control,farnesol inhibited biofilm formation by 26.4%with500 μmol/L and by 37.1%with 1,000 μmol/L（P〈 0.05）.Last,decreased transcription levels of luxS,brpA,ffh,recA,nth,and smx genes were expressed in farnesol-treated biofilms.In vitro farnesol inhibits caries development and S.mutans biofilm formation.The regulation of luxS,brpA,ffh,recA,nth,and smx genes may contribute to the inhibitory effects of farnesol.

Farnesol纳米胶束的构建及对变形链球菌的抑菌作用研究

目的:构建水溶性Farnesol纳米胶束,并研究其对变形链球菌的抑菌作用。方法:采用乳化溶剂扩散法制备Farnesol纳米胶束。通过Malvern粒度仪检测粒径、聚合物分散性系数(PDI)、Zeta电位3项指标,计算载药量及包封率;并考察其稳定性、水溶性、体外释放行为等。通过扫描电镜评价Farnesol纳米胶束对变形链球菌菌斑生物膜形态的影响。采用微板法检测菌悬液中钙离子浓度,探讨Farnesol纳米胶束对变形链球菌产酸及釉质脱矿的抑制作用。结果:Farnesol纳米胶束水溶液澄清,无沉淀。粒径为(19.78±0.21)nm,Zeta电势为(-12.2±0.4)mV,PDI为0.089±0.040,载药量为(8.3±0.5)%,包封率为(46.89±1.10)%,12 h累计释放70%。该纳米胶束能够抑制变形链球菌抑制菌斑生物膜的形成,降低产酸能力抑制釉质脱矿,且呈浓度依赖性。结论:Farnesol纳米胶束制备良好,具有水溶性、稳定性和缓释性等特点,并可抑制变形链球菌的生长,降低其产酸能力,对龋病的防治有重要的临床指导价值。

Effects of Farnesol on Drug-Resistant and Non-Resistant <i>Candida albicans</i>: Implications for Cosmetic and Pharmaceutical Applications

Background: Farnesol is added to numerous consumer products that intentionally, or inadvertently come in contact with tissues that may harbor the opportunistic yeast, Candida albicans. Objective: This study explores biological consequences of the exposure of Candida albicans from community infections or from a panel of antifungal drug resistant organisms on growth and survival of these organisms when exposed to farnesol. Methods: ATCC supplied Candida albicans from the MP8 drug resistance panel and an additional 12 strains of community-acquired Candida albicans were cultured in the presence of farnesol. With standard micobiologic techniques and flow cytometry evaluation, a series of experiments considered growth, morphology, viability and entrance into the quiescent persister phenotype of Candida with emphasis on differences between drug resistant and community organisms. Results: Differences growth yield, relative cell size and heat susceptibility distinguished the community organisms from the drug-resistant organisms. Using a subset of these organisms, exposure to farnesol resulted in diminished growth, inhibited hyphal growth, diminished cell membrane integrity and increased heat stress susceptibility. Data provided suggest that exposure to farnesol pushes cultures of Candida albicans toward the quiescent persister phenotype. Conclusion: Exposure of drug resistant and community strains of Candida albicans are modestly affected by farnesol in ways that may lessen their pathogenic potential. In contrast, the tendency of farnesol to engender greater numbers of quiescent organisms could support persistence of Candida.

Tyrosol和Farnesol对白念珠菌生物被膜形成作用的基因表达谱研究

目的研究Tyrosol和Famesol对不同时相白念珠菌生物被膜形成的调控机制。方法研究对象为白念珠茵标准株SC5314。设立Tyrosol处理组、Farnesol处理组、Tyrosol和Famesol联合处理组、对照组。生物被膜6h和24h收集细胞，提取RNA，反转录cDNA。cDNA与白念珠菌全基因组8K表达谱芯片杂交。采用LuxSean双通道激光扫描仪进行扫描。LttxSean3．0图像分析软件对芯片图像进行分析。借助KEGG基因库对芯片数据进行生物信息学分析。结果不同生物被膜时相，Tyrosol和Famesol对白念珠菌基因表达调控作用不同。Tyrosol和Farnesol调控生物被膜形成相关基因、菌丝相基因和酵母相基因。Tyrosol是生物被膜基因表达的正向调控效应因子。Farnesol是负向调控效应因子。Tyrosol和Famesol主要调控的基因包括生物学过程、分子功能及细胞成分相关基因，这些基因主要通过参与物质代谢通路调控白念珠菌生物学特点及生物被膜形成。结论Tyrosol和Famesol通过调控白念珠菌哇物被膜形成相关基因调控毕物被膜形成。

Tyrosol和Farnesol对白念珠菌生物被膜形成作用初探

目的研究密度感应分子（quorum sensing molecule）tyrosol（对羟基苯乙醇）和farnesol（法呢醇）对白念珠菌生物被膜形成的调控作用。方法在tyrosol和farnesol干预下构建白念珠菌临床株和标准株生物被膜，在倒置显微镜下观察细胞形态，应用RT-PCR技术检测密度感应分子对白念珠菌HTA1和EFG1基因表达的调控作用，并采用MTT法观察密度感应分子对细胞活性的影响。结果tyrosol对白念珠菌生物被膜的菌丝发生和细胞活性无明显促进作用，也无法中和farnesol对菌丝发生和细胞活性的抑制作用。tyrosol使白念珠菌生物被膜内细胞HTA1的表达增强，对EFG1的表达并无明显影响；tyrosol不能改变farnesol对HTA1和EFG1表达的抑制作用。结论tyrosol能在一定程度恢复口腔白念珠菌生物被膜内细胞的活跃状态，但当tyrosol与farnesol同时存在时，tyrosol的作用被后者的抑制效应所掩盖，细胞对farnesol更敏感。

附子理中汤通过FXR-FGF15通路影响非酒精性脂肪肝胆汁酸代谢

目的探讨附子理中汤对非酒精性脂肪性肝病(NAFLD)大鼠胆汁酸(TBA)代谢和肝脏损伤的影响及其机制。方法采用脂肪乳灌胃大鼠,连续4周,构建NAFLD动物模型。造模后用附子理中汤和阳性药物干预治疗,将大鼠分为对照组、模型组、附子理中汤组和阳性药物组。HE染色观察肝脏的病理变化,生化分析法检测高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、游离脂肪酸(NEFA)的含量,Western blot检测回肠组织中法尼酯X受体(FXR)、成纤维细胞生长因子15(FGF15)的蛋白表达和肝脏组织中FXR的蛋白表达,RT-PCR检测回肠组织中FXR、FGF15的mRNA表达和肝脏组织中FXR的mRNA表达,ELISA检测肝组织TBA水平。结果与对照组比较,模型组大鼠肝脏出现严重病理损伤,血清中HDL-C含量下降,LDL-C和NEFA含量增加(均P<0.01),大鼠肝脏组织中FXR蛋白、mRNA表达和回肠组织中FXR、FGF15的蛋白、mRNA表达上升(均P<0.01),肝组织中TBA水平下降(P<0.01)。与模型组比较,附子理中汤组和阳性药物组大鼠肝脏病理损伤缓解,HDL-C含量增加,LDL-C和NEFA含量下降(均P<0.05),大鼠肝组织中FXR蛋白、mRNA表达和回肠组织中FXR、FGF15蛋白、mRNA表达下降(P<0.05),肝组织中TBA水平增加(P<0.01)。结论附子理中汤治疗可通过激活回肠FXR-FGF15信号,增加肝脏TBA代谢,缓解NAFLD引起的肝损伤。

草蔻提取液对鸭肉质构特性及金合欢醇对肌原纤维蛋白结构的影响

为明确草蔻提取液对鸭肉质构的影响机制,分析草蔻提取液主效成分金合欢醇对肌原纤维蛋白(Myofibrillar Protein,MP)结构的影响,测定了不同处理组鸭肉弹性和硬度,采用电子鼻技术检测了不同处理组鸭肉的风味差异,分析了金合欢醇对MP结构的影响,包括羰基含量、表面疏水性、巯基含量以及二酪氨酸荧光强度的变化。结果表明:与固体草蔻相比,草蔻提取液能使鸭肉硬度显著降低54.61%(P<0.05),且草蔻提取液组鸭肉风味与固体草蔻组相比无明显区别。金合欢醇能显著降低MP羰基含量73.16%(P<0.05),显著降低表面疏水性30.35%(P<0.05),显著增加巯基含量84.24%(P<0.05)。此外,添加金合欢醇的MP二酪氨酸荧光强度降低了17.37%。综上所述:草蔻提取液能显著降低提高鸭肉硬度,主要原因是金合欢醇能与MP相互作用稳定其结构,并发挥一定的抗氧化作用。本研究可为草蔻提取液在标准化卤制的应用中提供理论依据。

基于法尼醇X受体通路探讨壮药依山红对胆汁淤积大鼠的影响

目的探讨壮药依山红对α-萘异硫氰酸酯(alpha-naphtyl isothiocyanate,ANIT)诱导胆汁淤积大鼠的影响及其作用机制。方法采用120只SD大鼠,随机分成6组,分别为正常组、模型组、熊去氧胆酸组及壮药依山红高、中、低剂量组,每组20只。除正常组外,余用ANIT灌胃建立胆汁淤积大鼠模型。连续给药15天后,称量计算大鼠肝脾指数;血清生化法检测血清丙氨酸氨基转移酶(alanine aminotransferase,ALT)、门冬氨酸氨基转移酶(aspartate aminotransferase,AST)、碱性磷酸酶(alkaline phosphatase,AKP)等转氨酶指标,测定总胆红素(total bilirubin,TBIL)、直接胆红素(direct bilirubin,DBIL)、总胆汁酸(total bile acids,TBA)等胆红素指标;苏木素—伊红(hematoxylin-Eosin,HE)染色法评估肝组织病理学变化,油红O染色评估肝脏脂滴代谢情况;蛋白免疫印迹法及实时荧光定量聚合酶链式反应检测法尼醇X受体(farnesoid X receptor,FXR)、钠牛磺胆酸共转运肽(Na+-taurocholate co-transporting polypeptide,NTCP)、多药耐药相关蛋白2(multidrug resistance-associated protein 2,MRP2)、胆汁盐转运蛋白(bile salt export pump,BSEP)蛋白和mRNA表达水平。结果与正常组比,模型组大鼠肝脾指数、血清转氨酶(ALT、AST、AKP)及胆红素(TBIL、DBIL、TBA)显著升高(P<0.05),肝组织受损。壮药依山红各剂量及熊去氧胆酸显著降低这些指标(P<0.05),改善肝组织学病变,减少脂滴沉积,效果呈剂量依赖性。同时,依山红各剂量组大鼠肝组织中NTCP、MRP2蛋白的表达量均明显升高(P<0.05);高剂量组大鼠肝组织中BSEP蛋白相对表达量显著下降(P<0.05)。与模型组相比,依山红高、中剂量组大鼠肝组织中Fxr、Ntcp、Mrp2 mRNA的相对表达量显著升高(P<0.05);依山红低剂量组大鼠仅Mrp2 mRNA表达量显著升高(P<0.05);依山红各剂量大鼠肝组织中Bsep mRNA表达水平显著下降(P<0.05)。结论壮药依山红可通过调节FXR及其调控的胆汁转运相关蛋白的表达,对ANIT诱导胆汁淤积模型大鼠起到保肝利胆的作用。

Systematic analysis of protein expression in Candida albicans exposed to farnesol

Background:The phenotypic switching of Candida spp.plays an important role in the development of vulvovaginal candidiasis(VVC).Farnesol,as a quorum-sensing molecule in Candida albicans,has the ability to prevent yeast-to-hyphal conversion in vitro.However,the mechanism underlying this ability is unclear.This study aimed to investigate changes in protein levels to better understand how farnesol impacts processes contributing to VVC.Methods:The isobaric tag for relative and absolute quantitation technique was used to detect protein expression in C.albicans strain SC5314(ATCC MYA-2876)with or without farnesol exposure.Proteins with a threshold fold change greater than 1.5 were screened and considered differentially expressed proteins.All the altered proteins were analyzed using Gene Ontology annotation,Kyoto Encyclopedia of Genes and Genomes(KEGG)annotation,and metabolic pathway annotation.Results:Between the farnesol-exposed group and the farnesol-unexposd group,we detected 297 altered proteins among all 2047 tested proteins based on a threshold fold change of more than 1.5(P<0.05).Eighty-seven of the 297 altered proteins exhibited metabolic enzyme activity and participated in 85 metabolic pathways according to KEGG pathway analysis.Most of these metabolic pathways were associated with central carbon metabolism processes.In the sterol synthesis pathway,which involves the synthesis of farnesol,ERG25(methylsterol monooxygenase)and ERG4(delta 24(24(1))-sterol reductase)were both down-regulated in the farnesol-exposed group.All six altered proteases associated with the oxidative phosphorylation process were down-regulated in the farnesol-exposed group relative to the farnesol-unexposed group.Conclusions:The mechanisms underlying farnesol-induced phenotype switching involves the adjustment of metabolic activities and epigenetic modification.Exogenous farnesol had an evident,but non-deterministic effect on the synthesis of ergosterol.The potential drug activity of farnesol warrants further investigation.

法尼醇脱氢酶基因在不同单倍型棉蚜中的分化及表达分析

棉蚜Aphis gossypii Glover种群出现明显分化,表现在生物型间的寄主偏好差异及单倍型间基因组层面分化。为了解棉蚜种群分化过程中激素合成相关基因的演变,选择Hap1和Hap3型棉蚜的法尼醇脱氢酶(HGO)进行分析。根据本实验室发布的两种单倍型棉蚜的基因组信息,在Hap1和Hap3型棉蚜基因组中各鉴定出5个AgosHGO基因,其中4个为重复拷贝,位于常染色体A1,另外1个位于常染色体A2。AgosHGO基因的CDS序列、基因结构在不同单倍型棉蚜间存在变异。在Hap3型棉蚜中,位于A1染色体上AgosHGO基因分布的区域存在一个Gypsy转座子的插入。利用NCBI公共数据已发布的棉蚜SRA数据,分析得到AgosHGO表达量与棉蚜的取食寄主显著相关,但不随体色及温度发生改变;AgosHGO3表达量在啶虫脒处理后显著下调50%;雄蚜成蚜期AgosHGO5表达量较若蚜期有显著上调,达14~20倍。本研究证实HGO基因在Hap1型和Hap3型棉蚜间出现分化,且其表达量能响应自身发育和外界环境变化,研究结果对于揭示棉蚜种群分化过程中激素响应的调控机制,开发基于激素调控的棉蚜生物防治技术具有重要的意义。

亚砷酸钠对人正常肝细胞脂质代谢及因子调控的作用

背景:肝脏作为砷毒作用的主要靶器官,成为砷毒性作用机制相关研究的焦点。目的:探讨亚砷酸钠对人正常肝细胞脂质代谢、细胞增殖、细胞凋亡及相关调控因子表达的影响。方法:MIHA正常人肝细胞株暴露于0,10,20,30μmol/L亚砷酸钠48 h,光学显微镜观察细胞形态变化,CCK-8法检测细胞活性,单试剂COD-PAP法、单试剂GPO-PAP法及酶微板法检测细胞上清总胆固醇、三酰甘油及总胆汁酸水平,油红O染色法检测细胞内脂质含量,Edu-488渗入法检测细胞增殖,PI染色法及Annexin V-FITC/PI双标记法结合流式细胞术分别检测细胞周期和细胞凋亡,实时荧光定量PCR和Western blot检测肝细胞核因子4α、胆固醇7α-羟化酶及法尼醇X受体的m RNA及蛋白表达水平。结果与结论:(1)与对照组(0μmol/L亚砷酸钠)相比,随着亚砷酸钠浓度的增加:MIHA细胞活性逐渐降低;细胞上清中总胆固醇、三酰甘油水平逐渐增高,总胆汁酸水平逐渐降低;细胞内脂质含量逐渐增多;细胞停滞于S期及G_2/M期细胞比例逐渐增多;细胞凋亡率逐渐升高;肝细胞核因子4α mRNA表达水平未见明显变化,胆固醇7α-羟化酶与法尼醇X受体mRNA表达水平下降;肝细胞核因子4α、胆固醇7α-羟化酶、法尼醇X受体蛋白表达水平逐渐下降;(2)亚砷酸钠具有细胞毒性,显著降低MIHA细胞活性,诱导细胞脂肪变性,阻滞细胞增殖,诱发细胞凋亡等损伤;亚砷酸钠可下调肝细胞核因子4α蛋白表达以及胆固醇7α-羟化酶、法尼醇X受体的转录和蛋白表达,进一步引起肝细胞的脂质代谢紊乱。

群体感应分子Farnesol联合CSA对白色念珠菌生物膜作用的实验研究

目的探讨群体感应分子法尼醇(Farnesol)联合钙调神经磷酸酶抑制剂环孢菌素A(CSA)对白色念珠菌的生物膜形成、形态转换、生长及活性、耐药性、凋亡反应和氧化应激反应的作用及其相关机制。方法体外构建生物膜状态白色念珠菌,分别经CSA、Farnesol、Farnesol联合CSA处理后,用qRT-PCR法检测生物膜状态白色念珠菌中生物膜形成过程中的相关基因CDR1、CEK1、CPH1、EFG1、ERG11、GPR1、HAT1、MDR1、HWP1、ALS3、TUP1mRNA表达水平的变化。结果白色念珠菌均具有不同程度的产膜能力,且单用CSA、Farnesol抗真菌药物对白色念珠菌生物膜的抑制率很低,而联合使用时,受试菌生物膜生长状态受到明显抑制。从临床血流感染中分离获得1株强产生物被膜白色念珠菌,命名为CA NX05;经不同药物组处理后生物膜状态白色念珠菌中的生物膜菌丝形成相关基因CEK1、CPH1、EFG1、ERG11、GPR1、HAT1、HWP1、ALS3、TUP1与其耐药性相关基因CDR1、MDR1的mRNA表达量与空白处理组相比均显著降低(F_(CEK1)=15.725,F_(CPH1)=6.230,F_(EFG1)=87.817,F_(ERG11)=17.527,F_(GPR1)=21.793,F_(HAT1)=65.318,F_(HWP1)=550.531,F_(ALS3)=10.514,F_(TUP1)=16.580,F_(CDR1)=8.089,F_(MDR1)=7.228;F>P,P<0.05)。结论群体感应分子Farnesol联合CSA处理较CSA及Farnesol处理能更有效地抑制白色念珠菌生物膜的形成,从而使其对抗真菌药物的敏感性增加,为临床合理使用抗真菌药物提供了科学导向。