Golgi apparatus-synthesized sulfated glycosaminoglycans mediate polymerization and activation of the cGAMP sensor STING

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百草枯对A549细胞中解整合素-金属蛋白酶17表达的影响

目的构建体外百草枯（paraquat,PQ）细胞纤维化模型,观察PQ对A549细胞中解整合素-金属蛋白酶17（ADAM17）表达的影响,探讨ADAM17在PQ中毒致肺纤维化中的作用。方法体外培养A549细胞,分为正常对照组、不同浓度PQ组,应用CCK-8检测细胞活力,筛选PQ浓度和时间,显微镜下观察细胞形态,ELISA测定各组纤维化标志物I型胶原（type I collagen,Col I）和纤连蛋白（fibronectin,FN）的表达,建立细胞纤维化模型;免疫细胞化学检测A549细胞中ADAM17的分布情况,RT-PCR和Western blot分别半定量检测ADAM17 mRNA及蛋白水平的表达情况。结果（1）随着PQ浓度增加及作用时间延长,A549细胞活力呈下降趋势,差异有统计学意义（P〈0.05）,呈剂量依赖性和时间依赖性。（2）正常的A549细胞融合呈铺路石样生长,排列比较紧密,经PQ诱导后细胞排列较松散,细胞间连接变疏松,部分细胞溶解、死亡。（3）ELISA显示,随PQ浓度增加,Col I和FN表达增强,差异有统计学意义（P〈0.05）;随PQ时间延长,Col I和FN表达也逐渐增强,差异有统计学意义（P〈0.05）,成功建立PQ细胞纤维化模型。（4）免疫细胞化学显示,ADAM17在A549细胞胞浆表达。（5）RT-PCR和Western blot表明,随着PQ浓度增加,ADAM17 mRNA及蛋白水平表达明显增加,差异有统计学意义（P〈0.05）,以PQ 200 umol/L时最为明显。随着PQ作用时间延长,ADAM17 mRNA及蛋白表达水平也明显增加,差异有统计学意义（P〈0.05）,在24 h达到高峰。结论百草枯可引起肺泡上皮细胞形态学改变,导致细胞损伤,成功建立细胞的纤维化模型,对A549细胞的毒性作用具有剂量和时间依赖性。ADAM17在PQ诱导的A549细胞中过表达,可能参与了百草枯诱导的肺纤维化过程。     

制备脱细胞真皮基质的实验研究

目的 采用高渗盐一胰蛋白酶法制备脱细胞真皮基质(Acellular dermal matrix,ADM)并进行组织学观察和微生物学检测,探讨这种方法的可行性和机制。方法 SD大鼠4只,分别麻醉后以8％硫化钠溶液脱去躯干部皮毛,常规消毒铺巾,切取大鼠背部全层皮肤制成厚约0.4mm的中厚皮,1mol／LNaCl溶液37℃浸泡48h分离表真皮,以0．25％胰蛋白酶 0.1％乙二酸二乙胺(EDTA)溶液37℃分别热消化60、70、80、90min脱去细胞成分,并进行冷冻干燥处理。ADM作光镜、电镜观察和微生物学检测并比较分析每只大鼠不同时间消化处理的ADM的差别和不同大鼠经相同处理得到的ADM的差别。结果消化时间不同的ADM均具有柔软、一定的柔韧性和伸展性、弹性好、弯曲不断裂的特点,组织学观察见表皮细胞均完全去除,但是消化90min,ADM的基底膜(Basement membrane complex,BMC)和胶原纤维的结构与排列有不同程度的破坏;消化60、70min的ADM虽然基底膜和胶原纤维的结构与排列正常存在,但脱细胞不完全;消化80min制备的ADM组织学检查基底膜完整连续．胶原纤维、弹力纤维结构及排列完整规则,没有细胞成分存在。不同SD大鼠经同样的处理所得的ADM一般形状和组织学没有明显差别。微生物学检测没有细菌生长。结论采用高渗盐一胰蛋白酶法制备脱细胞真皮基质的方法能达到既完全脱去细胞成分又使基底膜完整连续,胶原纤维和弹力纤维结构及排列正常的双重目标,ADM柔韧性好、不断裂,无细菌生长。     

Transmission events and antimicrobial susceptibilities of methicillin-resistant Staphylococcus argenteus in Stockholm

ObjectivesStaphylococcus argenteus has been increasingly reported since the species was defined as a novel staphylococcal species in 2015. This study aims to investigate genetic epidemiological links and antimicrobial susceptibilities of methicillin-resistant S. argenteus isolates recovered in Stockholm.MethodsSixteen methicillin-resistant S. argenteus isolates were identified from a collection of methicillin-resistant Staphylococcus aureus in Stockholm 2007–2018, by using whole-genome sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The genomes of the isolates were investigated by pulsed-field gel electrophoresis, single-nucleotide polymorphism (SNP)-based phylogeny, k-mer analysis, core-genome multi-locus sequence typing (cgMLST), resistance traits and virulence factors. The MICs of 19 antimicrobial agents for each isolate were determined by using the broth microdilution method.ResultsOf the 16 isolates, seven, seven and two isolates were assigned to ST1223, ST2250 and ST2793, respectively, with the S. aureus MLST-scheme. Analyses based on SNPs and cgMLST revealed a likely clonal spread of methicillin-resistant S. argenteus in 2007. Four isolates were found to be resistant to non-β-lactams in antimicrobial susceptibility testing.ConclusionsA transmission event of methicillin-resistant S. argenteus in family was identified by this study. Among our limited number of isolates, non-β-lactam resistance was detected, which highlights the necessity of a continued surveillance on this emerging pathogen. S. argenteus could be correctly identified by MALDI-TOF MS with the updated database, enabling its detection also in clinical laboratories.     

浅表食管癌侵袭深度及分化程度与区域淋巴结转移的临床分析

目的探讨浅表食管癌侵袭深度及分化程度与区域淋巴结转移的关系。方法本院2002年6月至2004年6月总共手术治疗食管癌923例,其中早期浅表食管癌68例,本文就对其术后侵袭深度及分化程度与区域淋巴结转移情况进行回顾性分析。结果本组无手术死亡,全组淋巴结转移率27%,其中高出黏膜型食管癌的淋巴结转移率为38%,侵袭越深,淋巴结转移率越高;分化程度越低淋巴结转移率越高。结论高度重视浅表型食管癌的根治性,对早期食管癌也应按肿瘤外科的原则行食管的次全切除术并常规清扫区域淋巴结。     

CD226 attenuates Treg suppressive capacity via CTLA-4 and TIGIT during EAE

The Cluster of differentiation 226(CD226)/T cell immunoglobulin and immune receptor tyrosine-based inhibitory motif domain (TIGIT) axis plays an important role in the balance of the immune response. A previous study showed that CD226 is involved in CD4+ T cell differentiation and that blocking CD226 may attenuate experimental autoimmune encephalomyelitis (EAE) development. However, the molecular mechanisms underlying this process remain incompletely understood. In this study, it was found that Cd226−/− mice were less susceptible to EAE and that there was less T helper 17(Th17) cell infiltration with higher levels of regulatory cells (Tregs) infiltration in the Cd226−/− EAE mouse central nervous system (CNS) compared with that in the WT EAE mouse CNS. Moreover, the suppressive function of Cd226−/− Tregs was upregulated compared with that of WT Tregs. Furthermore, it was observed that the expression levels of CTLA-4 and TIGIT on Cd226−/− Tregs were higher than those on WT Tregs during EAE in the spleen and CNS. Our results demonstrate a pivotal role for CD226 in attenuating Treg function in EAE that was associated with downregulating the expression levels of CTLA-4 and TIGIT.     

T follicular regulatory cells suppress Tfh-mediated B cell help and synergistically increase IL-10-producing B cells in breast carcinoma

T follicular regulatory (Tfr) cell is a recently discovered subset of T regulatory (Treg) cells. The main function of Tfr cells is thought to suppress germinal cancer reaction and inhibit B cell proliferation and Ig production. However, recent studies demonstrate that Tfr cells may be required for high-affinity Ig formation during acute virus infections. The role of Tfr cells in breast cancer is not thoroughly investigated. In this study, total circulating CD4 T cells were sorted into CD25⁺CXCR5⁻ Treg-like, CD25⁺CXCR5⁺ Tfr-like, and CD25⁻CXCR5⁺ Tfh-like subsets. Data showed that the Tfr-like subset presented intermediate levels of both Foxp3 and Bcl-6, while the Treg-like subset was high in Foxp3 and low in Bcl-6, and the Tfh-like was high in Bcl-6 and low in Foxp3. Of note, the frequencies of Tfr-like and Treg-like cells were significantly elevated in breast cancer (BC) patients than in non-cancer (NC) controls. Tfr-like cells in BC patients also expressed significantly higher levels of Foxp3 than those in NC controls. Neither Treg-like nor Tfr-like cells could support Ig production from naive B cells, while Tfh-like cells potently supported Ig production from naive B cells. Tfr-like cells increased the availability of IL-10, both by directly producing IL-10 and by increasing IL-10 production from B cells. Interestingly, Tfr-like cells increased IL-10 production from B cells synergistically with Tfh cells, but at the same time, significantly reduced Ig production in the Tfh-B cell coculture. These Tfr-mediated effects on Tfh cells were not found in canonical Treg cells. Overall, this study demonstrates several distinctive features in circulating Tfr cells and suggests that Tfr cells may promote the formation of IL-10-producing B cells in BC.

     

Identification and characterization of a novel natural recombinant avian leucosis virus from Chinese indigenous chicken flock

Virus Genes - Avian leukosis virus (ALV) caused tremendous economic losses to poultry industry all over the world, especially in China. One natural recombinant ALV strain, designated as HB2015032,...     

TNF-α/calreticulin dual signaling induced NLRP3 inflammasome activation associated with HuR nucleocytoplasmic shuttling in rheumatoid arthritis

Inflammation Research - The present study was undertaken to validate whether TNF-α and calreticulin (CRT) serve as dual signaling to activate nucleotide-binding oligomerization domain-,...