气道平滑肌细胞Ryanodine受体亚型mRNA的表达及其在哮喘中的变化

目的:测定正常大鼠气道平滑肌细胞(ASMCs)中Ryanodine受体(Ryanodine receptor RyR)各亚型mRNA的表达以及在哮喘中的变化.方法:采用胶原酶消化法培养大鼠ASMCs,RT-PCR测定受体各亚型mRNA的表达.卵蛋白致敏并激发大鼠制备慢性哮喘模型,RT-PCR测定各受体mRNA表达水平的变化.结果:大鼠ASMCs中可见RyR1、RyR2和RyR3三种RyR亚型mRNA共表达,扩增片段测序结果与GenBank中登录的大鼠RyR1-3序列完全一致.制备的慢性哮喘模型中,病理切片显示平滑肌层及黏膜层明显增厚,RyR1的表达较对照组有明显的上调P＜0.05.结论:大鼠气道平滑肌细胞中RyR三种亚型共表达,提示存在着复杂的细胞内钙调节机制;并且RyR1在慢性哮喘的发生过程中可能起了一定的作用.     

VEGF与其受体2在哮喘大鼠气道中表达变化及其对气道平滑肌细胞增殖的影响

目的探讨血管内皮生长因子(VEGF)及其受体2(Flk-1)在哮喘大鼠气道中表达变化及其对气道平滑肌细胞增殖的影响.方法 SD大鼠18只,随机分为对照组,哮喘模型组和地塞米松干预组各6只.以腹腔注射1%卵蛋白致敏和2%卵蛋白雾化吸入激发复制哮喘模型,干预组在每次激发前给予地塞米松干预.用免疫组织化学技术检测气道平滑肌α-actin以及VEGF和Flk-1蛋白质在不同组大鼠肺组织的表达程度;用RT-PCR方法检测VEGF和Flk-1mRNA在不同组大鼠肺组织的表达程度;采用HMIAS-2000型高清晰度彩色医学图文分析系统进行图像分析.结果 (1)哮喘模型组气道壁平滑肌厚度较对照组和干预组显著增加(P<0.05).(2)哮喘模型组VEGF及Flk-1蛋白质在大鼠肺组织中的表达较对照组和干预组显著增加(P<0.05).(3)哮喘模型组VEGF144,VEGF188 mRNA和VEGF205 mRNA在大鼠肺组织中的表达较对照组和干预组显著增加(P<0.05或P<0.01).哮喘模型组Flk-1mRNA在大鼠肺组织中的表达较对照组和干预组显著增加(P<0.05).直线相关性分析显示,气道壁平滑肌厚度与大鼠肺组织中VEGF205,188,144及Flk-1mRNA表达水平呈正相关(r分别为0.739,0.747,0.744,0.682;P<0.05);气道壁平滑肌厚度与大鼠肺组织中VEGF及Flk-1蛋白质表达水平也呈正相关(r分别为0.693,0.672;P<0.05).结论哮喘模型大鼠肺组织中VEGF及其受体Flk-1表达上调,并与气道平滑肌增殖有密切关系.该结果提示VEGF及其受体2可能参与了哮喘气道重建中气道平滑肌增殖的过程.     

雷公藤对哮喘大鼠气道重构及磷脂酰肌醇3激酶表达的影响

目的:探讨雷公藤内酯醇对哮喘气道重构及磷脂酰肌醇3激酶(PI3K)表达的影响。方法:将40只SD大鼠随机分为5组(n=8):A组(正常对照组);B组(哮喘4周组);C组(哮喘6周组);D组(给药4周组);E组(给药6周组)。测定气道反应性并观察气道壁嗜酸性粒细胞浸润;图像分析软件测定支气管壁厚度、支气管平滑肌厚度及支气管平滑肌细胞核数量;免疫组织化学染色、逆转录聚合酶链式反应(RT-PCR)检测PI3K蛋白及mRNA表达。结果:①B组、C组PI3Kp85α的蛋白及mRNA表达水平显著高于A组(P均<0.01),E组上述指标较B组、C组、D组均显著降低(P<0.01、P<0.01、P<0.05);②B组及C组支气管壁厚度、支气管壁平滑肌厚度、支气管壁平滑肌细胞核数量均较A组明显增加(P均<0.01),而E组上述指标较B组、C组、D组均显著降低(P均<0.01);③B组、C组的气道反应性均高于A组(P均<0.01),E组较B组、C组、D组均显著降低(P<0.01、P<0.01、P<0.05)。结论:气道平滑肌增生是气道重构的一个显著特征,PI3K可能在此起促进作用。雷公藤内酯醇可能通过下调PI3K的表达而减轻哮喘气道高反应性及抑制气道平滑肌增生,对哮喘气道重构有一定治疗作用。     

支气管哮喘豚鼠肺组织中KLF2 的表达及意义

目的:探讨锌指Krüppel样转录因2(KLF2)在豚鼠支气管哮喘肺组织中的表达及意义。方法:30只健康雄性豚鼠,按随机数字表法分为对照组(A组)、哮喘组(B组)及地塞米松治疗组(C组),每组10只。卵清蛋白致敏法复制哮喘模型。观察豚鼠肺组织病理学改变,BALF细胞总数及分类计数;采用原位杂交和RT-PCR检测肺组织中KLF2的mRNA表达情况,免疫组化和Westernblot检测肺组织中KLF2的蛋白表达水平。结果:(1)哮喘组豚鼠BALF中细胞总数、嗜酸性粒细胞百分比(EOS%)、中性粒细胞百分比(NEU%)显著高于对照组(P<0.01),哮喘组肺组织可见大量炎症细胞浸润,及明显气道重塑改变,而地塞米松治疗组BALF炎细胞浸润及肺组织病理改变较哮喘组明显减轻;(2)KLF2mRNA和蛋白在哮喘组表达显著低于对照组,在地塞米松治疗组中的表达明显高于哮喘组,3组差异均有统计学意义(P均<0.01);(3)KLF2蛋白以及mRNA与肺泡灌洗液炎细胞总数及EOS%,NEU%呈负相关。结论:KLF2在支气管哮喘急性发作期模型中表达明显下降,而地塞米松治疗后KLF2的表达上调,提示KLF2可能在支气管哮喘的发病机制与防治中起重要作用。     

西地那非抑制低氧肺血管内皮向平滑肌样细胞的转分化及其机制

目的探讨低氧条件下肺动脉内皮细胞(PAECs)向平滑肌样细胞的转分化及西地那非(sildenafil)对其的作用和可能机制。方法经免疫磁珠法(用血小板内皮细胞粘附分子PECAM-1做免疫分选标记)纯化分离的原代肺动脉内皮细胞,分为常氧组(含21%O2,5%CO2和74%N2)、低氧组(含1%O2,5%CO2,94%N2)、常氧 sildenafil组和低氧 sildenafil组。分别培养1d和7d。免疫荧光检测平滑肌特异性标志物α-平滑肌肌动蛋白(α-SM-actin)的表达,结合形态学鉴定平滑肌样细胞的转分化;用逆转录-聚合酶链式反应法(RT-PCR)检测myocardin mRNA的表达。结果(1)免疫荧光结果显示低氧7d组PAECs中α-SM-actin阳性率(2.07‰±0.06)(P<0.05)明显增高,阳性细胞呈梭形或多角形,而常氧组和低氧1d组均未见α-SM-actin的阳性表达;(2)RT-PCR显示myocardin mRNA的表达在低氧7d组(0.23±0.03)(P<0.05)明显增高,常氧各组和低氧1d组均未检测出其表达。(3)用sildenafil后,平滑肌样细胞的转分化率明显低于对应低氧7d组(1.02‰±0.05;P<0.05);Myocardin mRNA水平也明显降低(0.09±0.02)(P<0.05)。结论低氧可促进PAECs向平滑肌样细胞的转分化,sildenafil在一定程度上可抑制其转分化,其可能机制是通过抑制myocardin基因的表达而实现的。     

血管内皮生长因子及其受体2与哮喘模型大鼠气道平滑肌细胞增殖关系的研究

目的探讨血管内皮生长因子(VEGF)及其受体2(Flk-1)在哮喘大鼠气道平滑肌细胞(ASMC)中表达变化及其对ASMC增殖的影响。方法 SD大鼠18只,随机分为对照组,哮喘模型组和地塞米松干预组各6只,并培养各组气道平滑肌细胞。用免疫组织化学技术检测ASMC增殖细胞核抗原(PCNA)的表达;用RT-PCR及Western blot方法分别检测VEGF和Flk-1mRNA及蛋白质在不同组大鼠ASMC的表达程度。结果(1)哮喘模型组ASMC PCNA表达较对照组和干预组显著增加(P0.05)。(2)哮喘模型组ASMC VEGF164,VEGF188mRNA和VEGF205mRNA的表达较对照组和干预组显著增加(P0.05或P0.01)。(3)哮喘模型组ASMC VEGF及Flk-1蛋白质在大鼠ASMC中的表达较对照组和干预组显著增加(P0.05)。直线相关性分析显示,大鼠ASMC PCNA表达与大鼠ASMC中VEGF205,188,164及Flk-1mRNA表达水平呈正相关(r分别为0.79,0.86,0.83,0.68;P0.05);大鼠ASMC PCNA表达与大鼠ASMC中VEGF及Flk-1蛋白质表达水平也呈正相关(r分别为0.80,0.77;P0.05)。结果 哮喘模型大鼠ASMC中VEGF及其受体Flk-1表达上调,并与气道平滑肌细胞增殖有密切关系。该结果提示VEGF及其受体2可能参与了哮喘气道重建中气道平滑肌细胞增殖的过程。     

Ghrelin对豚鼠胃窦平滑肌细胞钙离子浓度的影响及与NO关系研究

目的:探讨Ghrelin对豚鼠胃窦平滑肌细胞内钙离子浓度的影响及其与一氧化氮(NO)的关系。方法:采用荧光免疫组化检测胃窦平滑肌细胞ghrelin受体(GHS-R)的表达;应用钙离子(Ca2+)指示剂Fluo-3/AM作为细胞内Ca2+的荧光探针,对负载培养的平滑肌细胞应用激光共聚焦显微镜技术,检测不同浓度ghrelin对平滑肌细胞内Ca2+荧光强度(FI)的影响,以及ghrelin受体阻断剂D-Lys3-GHRP-6、NO供体硝普钠(SNP),一氧化氮合酶(NOS)抑制剂N-硝基左旋精氨酸甲酯(L-NAME)对ghrelin调控Ca2+荧光强度的影响。结果:(1)豚鼠胃窦平滑肌细胞呈GHS-R免疫反应阳性表达.(2)随着ghrelin浓度升高(10-11,10-10,10-9,10-8,10-7mol/L),平滑肌细胞内Ca2+荧光强度逐渐升高,组间峰值(分别为54.7±11.5,58.1±5.7,64.8±6.6,84.9±7.1,95.7±10.5)和峰高(分别为1.8±0.3,2.1±0.8,5.3±1.3,28.9±4.2,37.6±3.7)均存在显著差异(P<0.05-0.01),即呈明显剂量依赖...     

IL-13对小鼠AGR2表达的影响及其在哮喘气道黏液过度分泌中的作用

目的研究白细胞介素-13(IL-13)对AGR2mRNA和蛋白在哮喘小鼠肺组织中表达的影响,探讨AGR2在哮喘气道黏液过度分泌中的作用。方法 18只雌性小鼠随机分为哮喘组、对照组和IL-13组,IL-13组于26d-28d激发前经鼻滴入100μg重组小鼠IL-13。收集支气管肺泡灌洗液(BALF)计嗜酸性细胞分类计数。Real time-PCR方法检测肺组织AGR2mRNA表达。免疫组化法分别检测AGR2蛋白和Muc5ac蛋白在小鼠肺组织的表达。结果哮喘组BALF中嗜酸性细胞分类计数(19.1±6.34)%较正常组(0.28±0.29)%明显增多(P<0.01);IL-13组BALF中嗜酸性细胞分类计数(30.05±9.32)%较哮喘组明显升高(P<0.01)。IL-13组小鼠肺组织中AGR2mRNA(1.702±0.046)和蛋白(0.617±0.028)的表达较哮喘组(1.52±0.071,P<0.01;0.505±0.078,P<0.05)升高,IL-13组AGR2mRNA与Muc5ac蛋白的表达水平呈直线正相关(r=0.862,P<0.05);AGR2蛋白与Muc5ac蛋白水平呈直线正相关(r=0.847,P<0.05)。结论 AGR2可能参与了哮喘气道黏液过度分泌发病机制,IL-13可通过上调其表达,进一步促进黏蛋白Muc5ac表达。     

TNF—α对哮喘模型大鼠气道平滑肌细胞增殖及ERK1／2活性的影响

目的探讨TNF—α对哮喘大鼠气道平滑肌细胞（ASMCs）增殖及对ASMCs上ERK1／2mRNA、p-ERK1／2表达水平的影响。方法通过对哮喘模型大鼠ASMCs培养,分别以0．2μg／L、1．0μg/L、20μg/L TNF-α干预ASMCs生长。采用流式细胞仪、MTT法检测ASMCs增殖情况,观察不同浓度TNF—α对ASMCs增殖的影响。RT-PCR检测ASMCs上ERK1／2mRNA表达,免疫细胞化学染色法检测磷酸化ERK1／2蛋白的表达及定位。结果哮喘组ASMCsS期比例、A值、ERK1／2mRNA、p-ERK1／2蛋白的表达量分别为（34．45±2．08）％、（0．550±0．010）、（0．995±0．118）、（130．77±4．16）,与对照组（11．17±0．96）％、（0．292±0．008）、（0．576±0．098）、（163．82±1．38）比较均显著增高（均P〈0．01）。各TNF—α干预组ASMCs的S期比例、A值、ERK1／2mRNA和p-ERK1／2蛋白表达量与哮喘组比较均显著降低（均P〈0．01）,0．2μg/L和1．0μg／LTN-α组p-ERK1／2蛋白表达量高于对照组（P〈0．01）,20μg／L TNF-α组p-ERK1／2蛋白表达量与对照组比较无差异（P〉0．05）。结论与正常鼠相比,慢性哮喘大鼠气道平滑肌细胞增殖明显,处于S期的细胞比例明显增高。经TNF—α干预后,慢性哮喘大鼠气道平滑肌细胞处于S期的细胞比例减少,增殖减弱,TNF-α可能抑制慢性哮喘大鼠气道平滑肌细胞增殖。TNF—α可下调慢性哮喘大鼠气道平滑肌细胞上ERK1／2mRNA及p-ERK1／2表达,TNF-α可能通过抑制ERK信号转导通道的活性对气道平滑肌细胞的增殖进行调控。     

哮喘豚鼠肺内ADM表达变化及对离体气管条张力的作用

目的：通过观察肾上腺髓质素（ADM）mRNA在豚鼠哮喘模型肺内的表达及对哮喘豚鼠离体气管条张力的影响,研究ADM在支气管哮喘（简称哮喘）发病机制中的作用。方法：用原位杂交方法检测ADM mRNA在豚鼠哮喘模型肺内的表达,用组胺诱导豚鼠离体气管条收缩后,观察不同浓度的ADM对其收缩作用影响。结果：原位杂交结果显示正常及哮喘豚鼠肺内均有ADM mRNA的表达,但哮喘组较正常组明显增多（P＜0．05）,ADM可抑制组胺诱导的哮喘豚鼠离体气管条的收缩,并呈量效关系,当浓度达10^-8mol/L时抑经达到最大,而且即使加大ADM的浓度,抑制率未继续明显增加,并对致敏气管螺旋条的舒张作用明显大于正常气管螺旋条。结论：哮喘时,肺内ADM mRNA的表达明显增多,ADM可抑制组胺诱导的豚鼠离体气管条的收缩,浓度为10^-8mol/L时抑制率达到最大。提示ADM在哮喘发病过程中起重要作用。     

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.     

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.     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.     

Composition and diversity of bird communities in Swedish farmland–forest mosaic landscapes

CapsuleThe amount of forest (at local and landscape scales) and occurrence of residual habitats at the local scale are shown to be the major factors influencing bird community composition in farmland–forest landscapes in central Sweden.

Aims To investigate the importance of local habitat and landscape structure for breeding birds in farmland–forest landscapes in central Sweden.

Methods Breeding birds were censused at 292 points. A detailed habitat mapping was made within 300 m of the points. Within a 300–600 m radius only two major habitats (forests and arable fields) were identified.

Results Cluster analyses of bird communities identified three site types that also differed in habitat composition: (i) partially forested sites in forested landscapes; (ii) heterogeneous sites with residual habitats in mosaic landscapes; and (iii) field-dominated farmland sites in open landscapes. A total of 19 of 25 farmland bird species (restricted to farmland or using both farmland and forest) had the highest abundance in farmland sites with mosaics of forest and farmland, while only six farmland species had the highest abundance in field-dominated sites. The bird community changed from being dominated by farmland species to being dominated by forest species (common in forest landscapes without farmland) at small proportions (10–20%) of forest at the local scale. A major difference in habitat composition between heterogeneous and field-dominated sites was the occurrence of different residual habitats (e.g. shrubby areas and seminatural grasslands). These habitats seemed to influence bird community composition more than land-use, despite covering <10% of the area. Seminatural grasslands were important for bird community composition and species-richness, but grazing seemed to be less important. Among different land-use types, cereal crops were the least preferred fields. Set-asides with tall vegetation and short rotation coppices were positively associated with species-richness of farmland birds.

Conclusion In general, the composition of the landscape was important for bird community composition, although amount and distribution of forests, occurrence of residual habitats and land-use of fields at the local scale had the strongest influence on bird community composition. The possible implications of these patterns for managing farmland–forest landscapes are discussed.     

Chemical constituents from the fruits of Rhus typhina L. and their chemotaxonomic significance

This work describes the isolation and characterization of twenty-nine compounds from the fruits of Rhus typhina L., including eleven flavonoids (1–11), eleven phenols (12–22), two pentacyclic triterpenes (23–24), two organic acids (25–26), one lumichrome (27), one courmarin (28) and one pyrimidine (29) on the basis of their spectroscopic data. Compounds apigenin (1), daidzein (4), orobol (5), 3′, 5, 5′, 7-tetrahydroxyflavanone (6), naringenin (7), butein (8), (-)-catechin (9), quercetin-3-O-α-L-(3″-O-galloyl)-rhamnoside (11), 2-hydroxybenzoic acid (13), 4-hydroxybenzaldehyde (14), vanillin (15), methyl 3,4-dihydroxybenzoate (16), 3,5-dihydroxybenzamide (18), tyrosol (19), caffeic acid (20), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (21), phlorizin (22), friedelin (23), oleanolic acid (24), 4,4-dimethyl-heptanedioic acid (25), anthranilic acid (26), lumichrome (27), scoparone (28) and uracil (29) have not been recorded before in this plant. This is the first report on the occurrence of compounds 4–7, 9, 11, 13–14, 16, 18–21, 25–29 from the genus Rhus. Moreover, the chemotaxonomic significance of these isolated compounds was also summarized.