hMSCs成骨诱导前后免疫调节的实验研究

目的:从免疫学机制方面探讨人骨髓间充质干细胞(Human bone marrow derived mesenchymal stem cell,hMSCs)、成骨诱导后骨髓间充质干细胞(Osteogenic cells differentiated from mesenchymal stem cells,DOC)免疫调节作用的可能机理。方法:hMSCs、DOC(成骨诱导6天、12天、18天),采用流式细胞技术(FACS),分别检测CD40、CD154、CD80、CD86、HLH-Ⅰ、HLA-Ⅱ在诱导前后其表达水平的变化。hMSCs和DOC(诱导18天),分别作混合淋巴细胞反应(CCK-8法),检测不同数量级hMSCs、DOC体外对双向混合淋巴细胞反应体系同种异体PBMCs增殖的影响,以及不同数量级hMSCs、DOC对经植物血凝素(PHA)刺激后同种异体PBMCS增殖的的影响。结果:hMSCs、DOC低水平表达CD40、CD154、CD80、CD86和HLA-Ⅱ,高水平表达HLA-Ⅰ。不同数量级hMSCs、DOC均可不同程度抑制同种异体PBMCs的增殖反应,其抑制效果大体与细胞量成正比,与阳性对照组相比,均有统计学差异(P<0.01)。结论:在体外实验中,hMSCs、DOC可能通过低免疫原性和降低T细胞的免疫应答从而维持其免疫调节功能。     

IL-10、TGF-β1在HPV相关宫颈病变中的作用

宫颈癌是危害全世界妇女健康的主要恶性肿瘤之一。宫颈癌及其癌前病变——鳞状上皮内病变(SIL)均由高危型人乳头瘤病毒(HPV)持续感染导致。HPV通过下调干扰素表达,促进白介素(IL)-10和转化生长因子(TGF)-β1表达,产生局部免疫抑制微环境,改变肿瘤表面抗原,抑制肿瘤免疫应答。本研究从分子水平分析论述肿瘤微环境中HPV和宫颈癌细胞通过可溶性免疫抑制因子IL-10、TGF-β1逃避宿主免疫反应可能的机制,阐明IL-10、TGF-β1在HPV感染中的免疫抑制功能。     

炎症和纤维标志物在痤疮增生性瘢痕形成中的表达

本研究旨在考察炎症和纤维标志物在痤疮增生性瘢痕形成中的表达模式及其在瘢痕形成中的作用。采用免疫组化和RT-PCR检测了20份痤疮增生性瘢痕组织和20份正常组织中抗炎细胞因子(IL-4和IL-10)、促炎细胞因子(IL-1β和TNF-α)和纤维化标志物(TGF-β1, TGF-β3, IGF-1R和SMAD2)的表达情况。研究显示,增生性瘢痕组织中IL-4和IL-10的阳性染色强度分别下降了36.13%和47.86%(p0.05),而IL-1β和TNF-α的阳性染色强度分别升高了1.34倍和5.37倍(p0.05)。增生性瘢痕组织中IL-4和IL-10的m RNA相对表达量分别下降了53.57%和62.28%(p0.05),而IL-1β和TNF-α的mRNA相对表达量分别升高了2.45倍和1.75倍(p0.05)。增生性瘢痕组织中TGF-β1、TGF-β3、IGF-1R和SMAD2的阳性染色强度分别显著升高了2.46倍、1.18倍、2.65倍和1.54倍(p0.05)。增生性瘢痕组织中TGF-β1、TGF-β3、IGF-1R和SMAD2的mRNA相对表达量均分别升高了4.02倍、2.11倍、3.78倍和2.45倍(p0.05)。本研究表明,增生性瘢痕组织中抗炎细胞因子IL-4和IL-10为低表达模式,而促炎细胞因子IL-1β和TNF-α为高表达模式,另外,纤维化标志物TGF-β1、TGF-β3、IGF-1R和SMAD2均为高表达模式。上述炎症和纤维化标志物均参与调节增生性瘢痕的形成。     

BMP2诱导C3H10细胞成骨分化的TGF-βⅠ型受体的体外分析

筛选和分析与BMP2诱导间充质干细胞C3H10成骨分化有关的TGF-βⅠ型受体.利用显性负性突变型TGF-βⅠ型受体竞争抑制配体功能的特性,运用碱性磷酸酶定量测定、Real time PCR等方法,初步筛选出可能与BMP2诱导间充质干细胞C3H10成骨分化有关的的TGF-βⅠ型受体,随后运用RNA干扰的方法抑制相应TGF-βⅠ型受体的表达,进一步证实相关TGF-βⅠ型受体与BMP2发挥诱导成骨活性的关系.结果证实,显性负性突变的ALK3和ALK6能够抑制BMP2诱导的C3H10细胞成骨分化;RNA干扰抑制ALK3或(和)ALK6表达后,BMP2诱导C3H10细胞向成骨分化的趋势受到抑制.因此,ALK3和ALK6是与BMP2诱导C3H10细胞成骨分化有关的TGF-βⅠ型受体.     

95例SARS患者的Th2细胞因子反应及其临床意义

本研究共收集95例罹患严重急性呼吸综合征(SARS)的医护人员的急性期和恢复期血清,用ELISA方法测定血清中白细胞介素2(IL-2)、白细胞介素4(IL-4)、白细胞介素10(IL-10)、干扰素γ(IFN-γ)、肿瘤坏死因子β(TNF β)以及转化生长因子β(TGF-β)水平,用流式细胞仪测定急性期患者外周血CD4+和CD8+T细胞比例.结果显示,SARS患者病程初、中期血清IFN-γ无明显改变;IL-2在起病2月内无显著变化,但在病程3～5个月时降低;IL-4在健康对照和患者均未能测出;TNF-β在SARS感染的1周内和病程第2个月内下降.与上述细胞因子形成对比,患者IL-10以及TGF-β均在发病起即持续升高直至整个病程.这些细胞因子的变化均与激素的使用无关(P＞0.05).SARS患者急性期CD4+T细胞和CD8+T细胞急剧减少.可见,SARS相关冠状病毒感染可引起Th2细胞因子反应,可能损害患者的细胞免疫功能而促进体液免疫,IL-10和TGF-β可能在SARS的发病中起作用.     

重楼皂甙Ⅱ对狼疮性肾炎患者外周血CD4+CD25+T调节细胞表达的细胞因子的影响

目的:研究重楼皂甙Ⅱ对狼疮性肾炎患者外周血CD4+CD25+Treg分泌的细胞因子IL-10和TGF-β的影响。方法:10例健康人为正常对照组,20例LN病人随机分为四组:LN对照组(n=5)、重楼干预组1(n=5,接种细胞数为1×105/1.5ml/孔)、重楼干预组2(n=5,接种细胞数为2×105/1.5ml/孔)、重楼干预组3(n=5,接种细胞数为5×105/1.5ml/孔)。分离外周血单个核细胞,利用免疫磁珠法分离CD4+CD25+Treg。重楼干预组予重楼皂甙Ⅱ干预,正常对照组和LN对照组不予处理,各组培养72h。取各组上清,用ELISA分别检测IL-10和TGF-β的水平。结果:与正常组比较,其余各组TGF-β和IL-10的水平明显降低(P<0.01)。与LN对照组比较,重楼皂甙Ⅱ干预后各组TGF-β和IL-10的水平升高(P<0.05)。重楼干预组之间比较,重楼干预组2的TGF-β和IL-10水平较其他两组明显升高(P<0.01),而重楼干预组1和3的TGF-β和IL-10水平变化无显著性差异(P>0.05)。结论:重楼皂甙Ⅱ可上调LN患者TGF-β和IL-10的水平,上调的幅度受接种细胞数量的...     

Treg细胞在慢性乙肝患者外周血中的表达及其对DC细胞的抑制作用

目的:检测慢性乙型肝炎患者外周血中Treg细胞的比例,探讨其对DC细胞的免疫抑制作用。方法:检测CHB患者和正常对照组外周血CD4+,CD25+,Treg及DC表面因子CD80和HLA-DR的表达;在DC培养不同时间内加入不同比例CHB Treg细胞,观察DC对淋巴细胞增殖的影响以及细胞因子IL-10及TGF-β的表达变化。结果:CHB患者外周血Treg细胞比例高于对照组,差异有统计学意义(P0.05);CHB患者DC细胞表面分子CD80和HLA-DR表达均低于对照组,差异有统计学意义(P0.05);经Treg细胞处理后,DC细胞刺激淋巴细胞的增殖能力下降,淋巴细胞增殖的抑制率显著升高(P0.05);随Treg细胞增加,IL-10及TGF-β水平升高,差异有统计学意义(P0.05)。结论:CHB患者外周血中Treg细胞的增加可能通过诱导IL-10和TGF-β的表达来抑制DC细胞的免疫功能。     

普伐他汀对心脏成纤维细胞转化生长因子-β1合成的影响

目的:探讨普伐他汀对醛固酮诱导新生大鼠心脏成纤维细胞转化生长因子-β1(TGF-β1)的影响。方法:采用胰酶消化法和差速贴壁分离法获取和培养心脏成纤维细胞,应用ELISA、Western-blot、RT-PCR的方法分别测定醛固酮、普伐他汀以及甲羟戊酸对心脏成纤维细胞培养液中TGF-β1水平和心脏成纤维细胞TGF-β1mRNA和蛋白质的表达。结果:与正常对照组相比,醛固酮(10-7mol/L)可促进心脏成纤维细胞培养液中TGF-β1水平和心脏成纤维细胞TGFβ-1mRNA和蛋白质的表达,提前给予普伐他汀(10-5,10-4,10-3mol/L)能剂量依赖性地抑制醛固酮的上述作用,同时这种抑制作用可被甲羟戊酸所逆转。结论:普伐他汀可抑制醛固酮诱导的心脏成纤维细胞TGF-β1mRNA表达以及蛋白质的合成和分泌,其机制可能与甲羟戊酸代谢途径有关。     

95例SARS患者的Th2细胞因子反应及其临床意义

本研究共收集95例罹患严重急性呼吸综合征（SARS）的医护人员的急性期和恢复期血清,用ELISA方法测定血清中白细胞介素2（IL-2）、白细胞介素4（IL-4）、白细胞介素10（IL-10）、干扰素γ（IFN-γ）、肿瘤坏死因子β（TNF-β）以及转化生长因子β（TGF-β）水平,用流式细胞仪测定急性期患者外周血CD4^＋和CD8^＋T细胞比例。结果显示,SARS患者病程初、中期血清IFN-γ无明显改变;IL-2在起病2月内无显著变化,但在病程3～5个月时降低;IL-4在健康对照和患者均未能测出;TNF-β在SARS感染的1周内和病程第2个月内下降。与上述细胞因子形成对比,患者IL-10以及TGF-β均在发病起即持续升高直至整个病程。这些细胞因子的变化均与激素的使用无关（P〉0．05）。SARS患者急性期CD4^＋T细胞和CD8^＋T细胞急剧减少。可见,SARS相关冠状病毒感染可引起Th2细胞因子反应,可能损害患者的细胞免疫功能而促进体液免疫,IL-10和TGF-β可能在SARS的发病中起作用。     

铁过载对Wnt信号诱导的ST2细胞成骨分化的作用及机制

该研究探究铁过载对Wnt信号诱导的小鼠骨髓基质细胞(ST2)成骨分化的作用及其可能的机制。采用柠檬酸铁铵(FAC)模拟铁过载微环境,用碱性磷酸酶(ALP)染色及生化定量检测成骨分化水平,qRT-PCR检测成骨分化标志基因Alp、Runx2、Osx、Col1以及Wnt信号靶基因Smad6、CyclinD1、Lef1、BMP4的mRNA表达水平,免疫荧光法检测β-catenin入核情况。结果显示,铁过载剂量依赖性抑制Wnt信号诱导的ST2成骨分化,同时显著降低Wnt信号诱导的成骨分化标志基因及Wnt信号靶基因的表达(P0.05),且铁过载抑制Wnt信号诱导的β-catenin入核。综上所述,铁过载抑制Wnt信号诱导的ST2细胞成骨基因和Wnt靶基因的表达,并通过抑制β-catenin入核而抑制ST2细胞成骨分化。     

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.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).