骨髓间充质干细胞抑制小胶质细胞介导的炎症反应

目的研究骨髓间充质干细胞(Bone Marrow Mesenchymal Stem Cells,BMMSCs)对小胶质细胞介导的炎症反应的抑制作用。方法实验分为四组:组一:小胶质细胞(BV2)生长于DMEM(High Glucose)培养液中;组二:BV2细胞生长于加入脂多糖(LPS)的上述培养液中;组三:BV2细胞、BMMSCs共培养于加入LPS的上述培养液中;组四:骨髓间充质干细胞(BMMSCs)生长于加入LPS的上述培养液中。观察BV2细胞的生长状态、电镜超微结构变化及其分泌的炎症因子TNF-α表达量的变化。结果光镜下BV2细胞密度依次为:组一组三组二,组四中BMMSCs生长状态良好;电镜下可见组二BV2细胞内出现大量肿胀及空泡化的线粒体、内质网等细胞器,少见生长活跃多核仁细胞,同时可见大量崩解细胞,组三细胞状态明显好于组二;BV2细胞分泌的炎症因子TNF-α表达量依次为组二组三组一组四。结论 BM-MSCs抑制小胶质细胞介导的炎症反应,进而发挥神经保护作用。     

甘薯提取物对谷氨酸所致PC12细胞损伤的保护作用初探

观察甘薯提取物对谷氨酸诱导的PC12细胞损伤的保护作用.将大鼠嗜铬细胞瘤细胞(PC12)分为空白对照组、模型组、甘薯提取物0.1、1.0、10.0 μg/mL低、中、高剂量组和1.0 μmol/L尼莫地平阳性药物对照组,用2.0 mmol/L谷氨酸造成PC12细胞损伤,MTT法测定损伤细胞的存活率,观察其细胞损伤的形态学变化,考察甘薯提取物对谷氨酸所致PC12细胞损伤的保护作用.结果表明甘薯提取物可明显提高谷氨酸诱导的PC12损伤细胞存活率,同时能够明显改善谷氨酸诱导的PC12损伤细胞的细胞形态变化,并呈现剂量相关性,具有一定的神经营养及保护作用.     

骨髓间充质干细胞移植对大鼠癫痫海马神经炎症的抑制作用研究

目的探讨骨髓间充质干细胞(BMSCs)移植对大鼠癫痫海马神经炎症的抑制作用。方法体外分离纯化SD大鼠BMSCs,BMSCs处理的无血清αMEM和单纯无血清αMEM分别设为实验组和对照组,而后应用ELISA检测BMSCs培养基中抗炎细胞因子单核细胞趋化蛋白-1(MCP-1)和肿瘤坏死因子-α-刺激基因-6(TSG-6)的表达。匹罗卡品腹腔注射诱导大鼠癫痫模型,侧脑室注射5×10~6个BMSCs和同体积生理盐水分别设为实验组和对照组,未经处理的SD大鼠设为正常对照,4 d后免疫组织化学检测各组海马小胶质细胞或活化的小胶质细胞表达变化。单因素方差分析检测各组数据差异,组间数据比较采用独立t检验。结果 BMSCs条件培养基中MCP-1(61.8±15.64)pg/ml和TSG-6(1.3±0.12)ng/ml的表达较对照组明显上升(P0.01)。匹罗卡品诱导癫痫模型后,小胶质细胞胞体和突起所占面积百分比(39.2%±7.68%)较正常对照组(11.7%±3.47%)明显增多(P0.01),且ED1染色发现小胶质细胞明显活化。BMSCs移植4 d后,小胶质细胞和活化的小胶质细胞表达较癫痫对照组明显下降(P0.01)。结论 BMSCs具有旁分泌抗炎细胞因子的潜能,其移植对大鼠癫痫海马神经炎症具有明显抑制作用。     

菟丝子提取物对活性氧引起已分化的PC12细胞损伤的保护作用

以常用的神经嗜铬细胞瘤PC12细胞株为实验模型,通过比较活性氧(ROS)作用细胞后的细胞活力、凋亡相关蛋白(p53、Bax)水平以及细胞中SOD、GSH、MDA的差异,发现菟丝子提取物不仅能提高ROS损伤的已分化PC12细胞活力,调节细胞中凋亡相关基因的表达,而且还能提高细胞中SOD和GSH的含量,降低MDA水平。由此表明,菟丝子提取物对ROS造成的PC12细胞损伤有一定的保护作用。     

急性白血病患者血清、脑脊液趋化因子SDF-1测定及意义

目的:为了探讨基质细胞衍生因子-1(stromal cell derived factor-1,SDF-1)及其受体CXCR4在急性白血病血清及脑脊液中的变化及临床意义。方法:用酶联免疫吸附双抗体夹心法(ELISA)测定45例急性白血病患者的血清及40例急性白血病患者的脑脊液中SDF-1,并分别与正常对照组比较。结果:1.ALL患者组、AML患者组及正常对照组血清的SDF-1水平分别为4255.46±2685.83,2405.10±905.24,2338.24±671.21(pg/ml),其中ALL组患者明显高于AML组及正常组,且差异具有统计学意义(P<0.05)。CNSL患者组及非CNSL患者组SDF-1血清水平分别为3696.30±432.49,3136.62±2157.64(pg/ml),组间无显著差别。2.ALL患者组、AML患者组及正常对照组脑脊液SDF-1水平分别为4576.15±1547.96,3097.20±1408.45,1983.61±857.98(pg/ml),其中急性白血病组高于正常对照组,差异具有统计学意义(P<0.05),ALL组高于AML组,差异也具有统计学意义(P<0.05)...     

妊娠高血压外周血中促Th2 的细胞因子水平及IL-2/IL-10 平衡 的临床意义

目的:检测妊娠高血压患者外周血中促Th2的分子IL-4、IL-2与IL-10的水平,探讨IL-2/IL-10在妊高症中的临床意义。方法:选择40例未妊娠妇女为对照组,30例正常妊娠妇女为妊娠组,28例妊娠高血压患者为妊娠高血压组,ELISA检测血清中IL-4、IL-2和IL-10的水平。结果:与对照组外周血中IL-4水平(0.53±0.04)pg/ml相比:正常妊娠组IL-4水平升高至(0.91±0.03)pg/ml(P<0.05),妊娠高血压组IL-4水平(0.67±0.35)pg/ml升高但明显低于正常妊娠组(P<0.01)。与对照组外周血中IL-2水平(0.41±0.05)pg/ml相比:正常妊娠组IL-2水平升高至(0.82±0.11)pg/ml(P<0.01);妊娠高血压组IL-2水平高达1.57±0.22(pg/ml)明显高于其它两组(P<0.01)。妊娠高血压组外周血中IL-10水平明显低于正常妊娠组IL-10水平(P<0.01);妊娠高血压组外周血中IL-2/IL-10比值明显高于于对照组及正常妊娠组的比值。结论:妊娠高血压患者外周血中细胞因子IL-2和IL-10分泌异常且诱导Th2细胞产生的IL-4降低,打破Th1/Th2平衡,致使Th1型免疫反应增强,使早孕期滋养细胞受到免疫损伤以致侵入能力下降,导致妊娠期高血压疾病的发生。     

周围神经损伤中P2Y12受体-p38MAPK通路的研究进展

周围神经损伤是临床中常见的神经损伤之一,神经胶质细胞和信号通路转导在周围神经损伤和再生修复中发挥重要作用。小胶质细胞的活化与周围神经损伤导致的神经损伤及疼痛密切相关,小胶质细胞是周围神经损伤与修复的关键场所。脊髓背角的小胶质细胞可被嘌呤信号通路的P2Y_(12)受体活化,进而导致p38MAPK磷酸化,造成相关神经损伤及感觉功能障碍。以脊髓背角的小胶质细胞为靶点,从P2Y_(12)受体-p38MAPK通路的角度可揭示周围神经损伤的部分可能机制。探究从嘌呤信号通路与小胶质细胞活化的新角度,将神经损伤后的P2Y_(12)受体与p38MAPK的磷酸化表达联系为P2Y_(12)受体-p38MAPK通路,可为临床治疗周围神经损伤提供新的思路。本文就周围神经损伤中P2Y_(12)受体-p38MAPK通路的研究进展作一综述。     

和厚朴酚抑制线粒体可溶蛋白诱导小胶质细胞活化的体外实验研究

目的:探讨线粒体可溶蛋白诱导小胶质细胞活化作用及和厚朴酚对小胶质细胞活化的影响。方法:培养BV2小胶质细胞,分空白对照组(control)、线粒体可溶蛋白组(MDP)、和厚朴酚干预组(HNK)。ELISA检测不同浓度线粒体可溶蛋白(MSP)刺激不同时间的细胞上清液中IL-6和TNF-α含量;RT-PCR半定量法测定各组转录因子Klf4的表达情况;倒置相差显微镜观察各组细胞形态变化。结果:1.ELISA:MSP(10μg/ml,100μg/ml)处理7h时,IL-6和TNF-α含量与control组比较显著升高(P0.05);100μg/ml MSP处理1、3、5、7h时,IL-6和TNF-α表达与control组比较明显升高(P0.05),且7h时HNK组含量明显低于MDP组(P0.05)。2.RT-PCR结果显示MDP组KLP4的表达显著高于空白对照组和HNK组(P0.05)。3.倒置相差显微镜观察示空白组胶质细胞形态呈静息状态;MDP组小胶质细胞的胞体变圆或者椭圆,突起消失,呈"阿米巴"状;HNK组活化状态的小胶质细胞明显减少。结论:线粒体可溶蛋白可以激活小胶质细胞,促进白细胞介素IL-6和TNF-α的释放,和厚朴酚能够有效地抑制线粒体可溶蛋白诱导的小胶质细胞活化,其机制可能是通过下调Klf4的表达发挥作用。     

慢性丙型肝炎患者治疗前后血清中IL-18、IFN-γ及IL-4的表达及意义

目的:研究慢性丙型肝炎患者治疗前后血清中白介素-18(IL-18)、干扰素-γ(IFN-γ)及白介素-4(IL-4)的表达情况,探讨IL-18、IFN-γ在及IL-4在慢性丙型肝炎发病中的作用及可能临床意义。方法:酶联免疫吸附法(ELISA)检测20例正常人,42例慢性丙型肝炎患者治疗前后血清中IL-18、IFN-γ在及IL-4水平。结果慢性丙型肝炎患者血清IL-18表达高于健康对照组(380.3±27.2pg/mlvs104.1±10.9pg/ml,P<0.05),血清IFN-γ表达也高于健康对照组(3.2±0.4IU/mlvs1.2±0.2IU/ml,P<0.05),而慢性丙型肝炎患者与健康对照组间IL-4表达无统计学差异(23.8±2.7pg/mlvs23.5±2.9pg/ml,P>0.05)。慢性丙型肝炎患者血清IL-18表达与谷丙转氨酶具有正相关性(r1=0.701,P<0.05);IFN-γ表达与谷丙转氨酶均具有正相关性(r2=0.629,P<0.05)。治疗前慢性丙型肝炎患者应对组血清中IL-18及IFN-γ表达高于无应答组(380.3±27.2pg/mlvs280.1±19.8pg/ml,P<...     

卵巢癌细胞与腹膜间皮细胞相互作用对VEGF和bFGF表达的影响

目的探讨卵巢癌细胞与腹膜间皮细胞(HPMC)相互作用对血管内皮生长因子(VEGF)和碱性成纤维细胞生长因子(bFGF)表达的影响。方法用Millicell将卵巢癌细胞SKOV3与HPMC进行非接触性共培养,用RT-PCR检测细胞VEGF及bFGF mRNA表达,ELISA检测细胞条件培养液中VEGF及bFGF蛋白水平。结果共培养后,SK-OV3 VEGF及bFGF mRNA表达分别为3.62±0.23及3.41±0.25,条件培养液中VEGF及bFGF蛋白水平分别为(523.5±24.9)pg/ml及(156.4±17.3)pg/ml,与SKOV3单独培养时相比,差别均有显著性(P<0.01)。HPMC共培养后VEGF及bFGF mRNA表达分别为3.96±0.09及3.54±0.21,条件培养液中VEGF及bFGF蛋白水平分别为(1567.62±45.42)pg/ml及(682.9±33.7)pg/ml,均明显高于HPMC单独培养时的水平(P<0.01)。结论卵巢癌细胞与HPMC均可合成VEGF及bFGF;二者共培养时,相互刺激表达更高的VEGF及bFGF。     

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.