牙龈卟啉单胞菌感染对hPDL细胞中成骨标志基因表达及炎症因子分泌的影响

目的观察牙龈卟啉单胞菌(P.gingivalis)感染对人牙周膜(hPDL)细胞中成骨标志基因表达及炎症因子分泌的影响。方法原代hPDL细胞,分为P.gingivalis感染的P.gingivalis组、常规处理的对照组,成骨诱导后茜素红染色检测矿化结节,PCR法检测成骨标志基因Runt相关转录因子2(RUNX2)、骨钙素(OCN)、骨保护素(OPG)、骨碱性磷酸酶(BALP)的mRNA表达量,ELISA法检测炎症因子肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-1β、IL-6的分泌量,Western blot检测核因子-κB(NF-κB)及NF-κB抑制蛋白(I-κB)的蛋白表达量。结果与对照组比较,P.gingivalis组细胞成骨诱导后茜素红染色的矿化结节明显减少,细胞中RUNX2、OCN、OPG、BALP的mRNA表达量及I-κB的蛋白表达量均明显降低,培养基中TNF-α、IL-1β、IL-6的分泌量及细胞中NF-κB的蛋白表达量均明显增加。结论 P.gingivalis感染hPDL细胞后能够抑制成骨分化、激活炎症反应且该作用与NF-κB通路的激活有关。     

齐墩果酸抑制肿瘤坏死因子-α诱导的成纤维细胞样滑膜细胞炎症因子表达及其机制研究

探讨齐墩果酸(Oleanolic acid,OA)对肿瘤坏死因子-α(TNF-α)诱导成纤维细胞样滑膜细胞的炎症因子表达的影响及其机制。首先复苏培养人成纤维细胞样滑膜细胞(FLS),通过RT-PCR检测细胞IL-6及IL-1βmRNA表达,采用Western blot方法检测p38MAPK及NF-κB蛋白表达变化,通过ELISA法检测细胞上清液中IL-6及IL-1β浓度。与对照组比较,TNF-α明显诱导FLS细胞IL-6及IL-1βmRNA的表达及上清液中IL-6及IL-1β的分泌(P0.05),同时磷酸化p38蛋白和核NF-κB明显增加(P0.05),且p38MAPK阻断剂SB203580能抑制TNF-α诱导的核NF-κB增加。OA呈浓度依赖性抑制TNF-α诱导的FLS细胞p38蛋白磷酸化和核NF-κB增加(P0.05)。且OA、p38MAPK通路抑制剂SB203580或NF-κB阻断剂BAY 11-7082均能抑制TNF-α诱导的IL-6及IL-1β分泌增加(P0.05)。综上所述,OA能抑制TNF-α诱导的FLS细胞炎症因子IL-6及IL-1β的产生,其机制可能与抑制p38MAPK/NF-κB信号通路有关。     

BET蛋白通过调控NF-κB通路参与炎症基因转录

目的:探讨特异性抑制溴结构域(bromodomain and extra-terminal,BET)蛋白对血管内皮细胞激活与早期动脉粥样硬化形成的作用及其分子机制。方法:1.原代分离培养脐静脉内皮细胞和小鼠心脏血管内皮细胞后用肿瘤坏死因α(TNFα)刺激模拟炎症过程,以小分子化合物JQ1特异性抑制BET蛋白,分组如下:(1)对照组;(2)TNFα(25 ng/m L)处理组;(3)TNFα+JQ1处理组。采用Realtime-PCR及流式细胞术检测各组细胞炎症因子m RNA及蛋白水平的表达,采用5XκB荧光素酶报告基因检测各组核转录因子kappa B(NF-κB)转录活性。2.LDL受体基因敲除(LDLR-/-)小鼠随机分为2组:JQ1组(n=8,JQ1腹腔注射,50 mg/kg,每天一次)和对照组(n=8,DMSO溶媒组),同时给予高胆固醇饮食8周,采用免疫组化方法检测主动脉弓部血管细胞黏附分子-1(VCAM-1)表达水平。结果:与对照组相比,TNFα组炎症因子m RNA、蛋白表达明显上调(P0.01),使用JQ1干预后,炎症因子E选择素(E-selectin)、P选择素(P-selectin)、VCAM-1及白细胞介素-8(IL-8)m RNA及蛋白表达均明显下调(P0.01)。LDLR-/-小鼠高脂饮食诱导8周后JQ1显著下调了主动脉弓部VCAM-1蛋白表达。5XκB荧光素酶报告基因结果显示,与TNFα(-)相比,TNFα(+)组荧光素酶报告基因活性增强,JQ1可以显著下调报告基因活性(P0.01)。结论:BET蛋白通过调控NF-κB信号通路参与了血管内皮炎症基因转录;抑制BET蛋白下调了NF-κB目的基因表达从而减轻了内皮激活及高脂诱导的早期动脉粥样硬化病理改变。     

AMPK激活剂下调爆发性肝炎小鼠肝内组织因子表达北大核心CSCD

腺苷酸活化蛋白激酶(AMP activated protein kinase,AMPK)是重要的代谢调节酶及炎症调控新靶点。以往研究显示,AMPK激活剂5-氨基咪唑-4-甲酰胺核苷酸转甲酰酶(5-amino-4-imidazolecarboxamide riboside,AICAR)可通过抑制炎症反应减轻脂多糖/右旋半乳糖胺(lipopolysaccharide/D-galactosamine,LPS/D-gal)诱导的爆发性肝炎。由于炎症可通过激活凝血反应加重组织损伤,本研究旨在以炎症诱导凝血反应为切入点探讨AICAR保肝效应的机制。腹腔注射LPS/D-gal建立爆发性肝炎小鼠模型,用Western blot检测肝内组织因子(tissue factor,TF)、缺氧诱导因子1-α(hypoxia-inducible factor 1α,HIF-1α)以及细胞核内核因子kappa B(nuclear factor kappa B,NF-κB)p65蛋白表达,用实时定量PCR检测肝细胞促红细胞生成素(erythropoietin,EPO)m RNA表达,用试剂盒检测肝组织乳酸(lactic acid,LA)水平。结果显示,LPS/D-gal可促进小鼠肝细胞内TF蛋白表达,提高细胞核内NF-κB p65水平,上调HIF-1α蛋白及EPO m RNA表达,并提高肝组织LA水平;而AICAR干预后,以上指标均明显下调。以上结果提示,AICAR可通过抑制NF-κB活性下调TF表达及凝血活性,从而减轻肝组织缺氧及代谢紊乱,这可能是AICAR减轻LPS/D-gal诱导的爆发性肝炎的新机制。     

AMPK激活剂下调爆发性肝炎小鼠肝内组织因子表达

腺苷酸活化蛋白激酶(AMP activated protein kinase,AMPK)是重要的代谢调节酶及炎症调控新靶点。以往研究显示,AMPK激活剂5-氨基咪唑-4-甲酰胺核苷酸转甲酰酶(5-amino-4-imidazolecarboxamide riboside,AICAR)可通过抑制炎症反应减轻脂多糖/右旋半乳糖胺(lipopolysaccharide/D-galactosamine,LPS/D-gal)诱导的爆发性肝炎。由于炎症可通过激活凝血反应加重组织损伤,本研究旨在以炎症诱导凝血反应为切入点探讨AICAR保肝效应的机制。腹腔注射LPS/D-gal建立爆发性肝炎小鼠模型,用Western blot检测肝内组织因子(tissue factor,TF)、缺氧诱导因子1-α(hypoxia-inducible factor 1α,HIF-1α)以及细胞核内核因子kappa B(nuclear factor kappa B,NF-κB)p65蛋白表达,用实时定量PCR检测肝细胞促红细胞生成素(erythropoietin,EPO)m RNA表达,用试剂盒检测肝组织乳酸(lactic acid,LA)水平。结果显示,LPS/D-gal可促进小鼠肝细胞内TF蛋白表达,提高细胞核内NF-κB p65水平,上调HIF-1α蛋白及EPO m RNA表达,并提高肝组织LA水平;而AICAR干预后,以上指标均明显下调。以上结果提示,AICAR可通过抑制NF-κB活性下调TF表达及凝血活性,从而减轻肝组织缺氧及代谢紊乱,这可能是AICAR减轻LPS/D-gal诱导的爆发性肝炎的新机制。     

脂多糖对新生小鼠肺血管内皮细胞的影响及机制探讨

该文旨在探讨脂多糖(lipopolysaccharide, LPS)对新生小鼠肺血管内皮细胞的影响及机制。将分离培养的肺血管内皮细胞随机分为空白对照组和LPS组;用10μg/mL的LPS处理细胞后分别于0 h、6 h、12 h、24 h、48 h时间点收集细胞标本进行检测;采用划痕实验观察LPS对肺血管内皮细胞迁移的影响;用荧光定量PCR(Real-time PCR, RT-PCR)检测白介素-1β(IL-1β)、巨噬细胞炎性蛋白-1α(MIP-1α)、单核细胞趋化蛋白-1(MCP-1)、肿瘤坏死因子-α(TNF-α) mRNA水平变化; Western blot检测血管内皮生长因子(VEGF)、血管内皮生长因子受体2(VEGFR2)及核因子κB(nuclear factor kappa-B, NF-κB)相关蛋白P65水平的变化。结果显示,体外分离培养的肺血管内皮细胞成鹅卵石样排列, VIII因子相关抗原和CD31表面抗原荧光染色阳性。划痕实验中, LPS组细胞在12 h的迁移高于对照组(P0.001);荧光定量PCR检测到LPS组分泌的炎症因子IL-1β、TNF-α和趋化因子MIP-1α、MCP-1的mRNA表达明显高于对照组(P0.001); Western blot显示, LPS组与对照组相比, VEGF蛋白表达在24 h、48 h处降低(P0.05), VEGFR2蛋白表达在各时间段都明显降低(P0.001),同时, NF-κB相关蛋白P65活性显著升高(P0.05)。研究表明,脂多糖诱发的炎症反应影响肺血管内皮细胞的发育,其机制可能与NF-κB通路激活,诱导炎症因子、趋化因子表达升高和VEGF/VEGFR2表达下降有关。     

丹参酮IIA 磺酸钠在创伤失血性休克过程中的保护作用研究

目的:研究中药提取物丹参酮IIA磺酸钠在创伤失血性休克中的作用。方法:复制SD大鼠创伤失血性休克模型,即经右侧股动脉插管放血,左侧股静脉建立液体通道,经颈动脉插管至左心室监测创伤失血性休克大鼠平均动脉压;在达到最大放血量后,治疗组大鼠给予丹参酮IIA磺酸(10mg/kg)。按时间点经股静脉取大鼠静脉血,测量血清肌酸激酶(CK)及乳酸脱氢酶(LDH)水平,比较各组心肌酶改变。并以酶联免疫法检测各组大鼠血清促炎因子IL-Iβ、IL-6、IL-10和TNFα的改变。结果:丹参酮IIA磺酸钠在一定程度上改善了创伤失血性休克导致大鼠的血流动力学的改变,显著减轻了炎症反应过程中的各种炎症因子的表达。结论:丹参酮IIA磺酸钠改善了创伤失血性休克导致大鼠的低血压;抑制了大鼠创伤失血性休克过程中炎症因子的表达,可能在创伤失血性休克过程中发挥保护作用,为临床提供了疗创伤失血性休克提供了新的可能的参考。     

热休克转录因子1的抗炎症作用

热休克转录因子1(heat shock factor 1, HSF1)是调节细胞保护性应激蛋白--热休克蛋白表达的主要转录因子,可被热应激、氧化应激等多种理化因素激活.近年研究表明,HSF1具有抗炎症作用:HSF1可抑制TNFα、IL-1β、M-CSF等致炎因子表达,促进IL-10等抗炎因子表达,并降低NF-κB、AP-1等致炎转录因子的活性.HSF1上调热休克蛋白和抑制炎症的双重活性,提示其很可能是联系应激反应和炎症反应的重要因子.     

绝经后骨质疏松症TNF-α通过激活NF-κB促进RANKL诱导的破骨细胞形成

本研究检测了绝经后骨质疏松症妇女的肿瘤坏死因子-α(TNF-α)和雌激素水平,并探讨了TNF-α对破骨前体细胞RAW264.7中破骨细胞标志物核因子κB受体激活因子(nuclear factor kappa-B, RANK)、组织蛋白酶K (Cathepsin K, CTSK)和凝血酶受体激活肽(thrombin receptor activating peptide, TRAP)以及核因子-κB (NF-κB)亚基(p65)和NF-κB抑制蛋白(IκBα)的影响。研究结果表明,绝经后骨质疏松症患者的TNF-α水平显著升高,而雌二醇水平显著降低。核因子κB受体激活因子配体(receptor activator for NF-κBligand, RANKL)处理1周后,破骨前体细胞RAW264.7中破骨细胞标志物RANK、CTSK和TRAP的mRNA和蛋白高度表达。与RANKL对照组相比,TNF-α处理可上调RANK、CTSK和TRAP m RNA的表达。但是,仅TNF-α不能诱导培养的RAW264.7细胞分化为破骨细胞成。TNF-α以剂量依赖性方式诱导NF-κB亚基p65和IκBα磷酸化,而NF-κB抑制剂处理则有效降低了RANK和TRAP的表达。本研究结论表明,绝经后骨质疏松症中TNF-α通过激活NF-κB来促进RANKL诱导的破骨细胞形成。     

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.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

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).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.