Deferoxamine preconditioning activated hypoxia-inducible factor-1α and MyD88-dependent Toll-like receptor 4 signaling in intestinal stem cells

Background/Purpose

Toll-like receptors (TLRs) are important regulators of innate immunity, and TLR4 pathway can regulate the survival, migration, and differentiation of stem cells, including intestinal stem cells (ISCs). Deferoxamine (DFO), a hypoxia-mimic compound, can activate the proliferation of ISCs. In this study, we investigated the response of TLR4 signaling to DFO-induced hypoxia in cultured ISCs in vitro.

骨髓来源半成熟树突状细胞诱导大鼠小肠移植免疫耐受

Objective To study MyD88 silent semi-mature DC (simDC) inducing immune tolerance in rat small bowel transplantation model. Methods All rats were randomly divided into three groups (n=6). Seven days before transplantation of intestine from F344 donors, Wistar recipient rats were injected with simDC (group A) , imDC (group B) and saline ( group C) through the penile dorsal vein respectively.Small bowel transplantation was performed and the survival time of recipients was observed. Serum IL-2 and IFN-γ levels were assayed. Results The survival time of recipients in group A was ( 13.7±1.2) days, which was significantly longer than that in groups B [(8.0±1.0) days,P<0. 05] and C [(6. 0±0. 8) days P<0. 05]. The serum levels of IL-2 and IFN-γ in group A were lower than in groups B and C (P<0. 05). Conclusion Depending on the unique phenotypic and functional features of sem-DC,they can induce the transplantation tolerance and prolong the survival of intestinal allografts after transplantatin.     

肌酐检测系统溯源性研究

目的:建立新成生物肌酐检测系统的溯源性,提高用户最终检测结果的准确性,为检测结果互认提供条件.方法:依据《GB/T 21415-2008/IS0 17511:2003》[1]中的国际标准溯源链式图自建新成生物溯源流程图;购买参考物质NIST SRM 909b,首先将厂商工作校准品溯源至参考物质,然后将产品校准品溯源至厂商工作校准品,并计算合成不确定度,完成新成肌酐产品校准品的量值溯源.结果:通过测定临床新鲜血清标本进行临床比对确保参考物质具有互通性,同时采用SPSS17.0进行统计学分析,以97％的预测区间和检测项目1/4CLIA’88总允许误差为标准,达到量值传递验证要求,进一步确定不确定度,完成量值溯源工作.结论:新成生物自建溯源流程成功对产品校准品进行了赋值,实现了产品校准品的溯源,提高了新成试剂检测结果的准确性.     

IL-10对脂多糖诱导Ana-1细胞的MyD88/核因子κB活性影响的研究

目的探讨IL-10对小鼠巨噬细胞髓样分化因子88(MyD88)/核因子κB(NF-κB)炎症信号活化的影响。方法将小鼠巨噬细胞Ana-1分为脂多糖(LPS)组和LPS+IL-10组,分别于0.5、1及2h收集巨噬细胞和细胞培养上清液,Western blot检测细胞MyD88与胞浆、胞核NF-κBp65亚基表达,ELISA法检测培养上清中肿瘤坏死因子α(TNF-α)含量。结果在0～2h,LPS组细胞MyD88表达显著持续上升,LPS+IL-10组于LPS刺激后上升,0.5h达峰值,2h恢复至正常水平,1h和2h相对含量均低于LPS组(11.6±1.3比17.5±0.7,8.8±0.3比21.4±1.8,P0.05);总NF-κB表达量在两组间无明显差异。NF-κB核浆比变化趋势与MyD88类似,LPS+IL-10组1h及2h相对含量亦均低于LPS组(1.1±0.1比2.4±0.4,0.6±0.7比3.1±0.6,P0.05);相应的,LPS+IL-10组1h和2hTNF-α含量亦低于LPS组[(222.5±33.5)pg/mL比(365.2±22.7)pg/mL,(212.7±15.9)pg/mL比(566.2±31.5)pg/mL,P0.05]。结论 IL-10通过抑制减少MyD88/NF-κB信号通路活化,降低TNF-α表达,从而下调炎症反应强度。     

慢病毒介导siRNA干扰MyD88表达对大鼠肺泡巨噬细胞功能的影响

目的采用RNA干扰技术,通过构建表达大鼠髓样分化因子88（MyD88）siRNA慢病毒干扰大鼠肺泡巨噬细胞MyD88g／表达,检测其对细胞功能的影响。方法针对MyD88基因,设计并构建3对siRNA表达质粒,分别与预先构建好表达MyD88N质粒共转染HEK-293T细胞,Westernblot检测MyD88的表达情况,筛选出其中1对干扰效率最高的siRNA,用Gateways方法构建慢病毒干扰载体包装成慢病毒,将慢病毒转染大鼠肺泡巨噬细胞系NR8383胞并加入内毒素（LPS）诱导,未转染慢病毒的细胞作为空白对照组和LPS激活组：空白对照组加入与LPS等体积的PBS;LPS激活组加入LPS刺激。ELISA测定各组细胞因子（IL-18、IL-6）释放情况。结果成功筛选出了1对干扰效率最高的siRNA并包装成慢病毒,病毒滴度为2．0×10^6TU／ml。LPS诱导后,与对照组相比．感染慢病毒的NR8383细胞MyD88表达明显受到抑制,IL-1β、IL-6的释放均显著减少,差异有统计学意义。结论慢病毒介导RNA干扰能够有效抑制NR8383细胞MyD88基因的表达,显著减少胞因子的释放,为以抗原提呈细胞（APC）为靶向的体内实验治疗大鼠肺移植相关闭塞性细支气管炎（obliterative bronchitis,OB）的研究提供了手段。     

Avian-specific TLRs and downstream effector responses to CpG-induction in chicken macrophages

Chickens possess toll-like receptor (TLR15), a pattern recognition receptor (PRR) absent in mammals. We characterized the regulation and mechanism of CpG responsiveness via TLRs in chicken macrophage HD11 cells. TLR15 was significantly upregulated after induction with B- and C-type CpG oligonucleotides (ODN), tripalmitoylated lipopeptide (PAM3CSK4), Escherichia coli- and Salmonella enteritidis-derived lipopolysaccharide (LPS). In response to CpG-ODN inhibitor, TLR15 and IL1B were downregulated, but TLR21 was upregulated. IL1B was upregulated with CpG-ODN and downregulated after inhibitor treatment. The results suggest that responsiveness to different types of CpG-ODN in chicken macrophages requires multiple receptors, each with unique variation in expression. We utilized RNA interference (RNAi) technology to examine myeloid differentiation primary response gene (MyD88) dependency of TLR15 and TLR21. HD11 macrophages transfected with multiple MyD88-target siRNAs exhibited 70% decrease in MyD88 mRNA expression. IL1B was upregulated with CpG induction in cells with no reduction of MyD88 mRNA levels, but not in cells with 70% MyD88 reduction. Therefore, induction through TLR15 in response to CpG-ODN operates via the MyD88-dependent pathway in chicken macrophages.     

Phospholipase Cgamma1 signalling regulates lipopolysaccharide-induced cyclooxygenase-2 expression in cardiomyocytes

Lipopolysaccharide (LPS) induces cyclooxygenase-2 (COX-2) expression in cardiomyocytes, which plays a role in myocardial depression during endotoxemia. The purpose of this study was to investigate the role of phosphatidylinositol (PI)-phospholipase Cgamma1 (PLCgamma1) in cardiac COX-2 expression in vitro and in vivo. In cultured mouse neonatal cardiomyocytes, LPS increased PLCgamma1 phosphorylation and COX-2 expression. Knockdown of PLCgamma1 with specific siRNA or inhibition of PI-PLC with U73122 attenuated COX-2 mRNA and protein expression induced by LPS (1 microg/ml). PLCgamma1 activation by LPS also increased ERK1/2 MAPK phosphorylation, and inhibition of ERK1/2 MAPK blocked the effect of PLCgamma1 on COX-2 expression. Furthermore, activation of PLCgamma1 is a consequence of the Src family activation since inhibition of Src abrogated whereas over-expression of Src enhanced PLCgamma1 phosphorylation and COX-2 expression in LPS-stimulated cardiomyocytes. To investigate the role of PLCgamma1 in endotoxemia, wild-type and PLCgamma1(+/-) adult mice were pre-treated with U73122, or its inactive analog, U73343 (9 mg/kg, i.p.), or vehicle for 15 min followed by LPS (4 mg/kg, i.p.) for 4 h. U73122 or heterozygous deletion of PLCgamma1 decreased cardiac COX-2 expression. The phosphorylation of ERK1/2 MAPK induced by LPS was also attenuated in U73122- or PLCgamma1(+/-) compared to U73343-treated or wild-type littermate hearts, respectively. In conclusion, our study suggests that PLCgamma1 signalling represents a novel pathway regulating cardiac COX-2 expression during LPS stimulation. The Src family is responsible for PLCgamma1 activation, which signals the ERK1/2 MAPK pathway, resulting in COX-2 production in LPS-stimulated cardiomyocytes.     

补体C5a受体拮抗剂体外筛选平台的建立

目的建立稳定的补体C5a受体(C5aR)拮抗剂筛选平台。方法采集人外周静脉抗凝血,与不同浓度C5a、脂多糖及PMX-53孵育10～30 min。通过流式细胞术检测中性粒细胞表面CD11b的表达,溶菌酶检测试剂盒观察中性粒细胞分泌溶菌酶的能力变化,罗丹明-123检测中性粒细胞呼吸爆发的变化,ELISA检测细胞上清液中白细胞介素(IL)-8的表达变化,Western Blotting检测胞外信号调节激酶(ERK)、蛋白激酶B(AKB或AKT)含量及其磷酸化水平的变化,考察补体C5a刺激及使用阳性药物PMX-53后对各生化指标的影响。结果 C5a刺激人外周血可增强中性粒细胞CD11b的表达,促进溶菌酶释放和IL-8的分泌,激发呼吸爆发,上调ERK、AKT的含量和磷酸化水平,阳性药物PMX-53则能显著抑制C5a的上述生物学效应。结论成功建立C5aR拮抗剂人全血体外筛选平台,为C5aR拮抗剂筛选及功能研究奠定了基础。     

Hydrophobicity-dependent QSARs to predict the toxicity of perfluorinated carboxylic acids and their mixtures

Perfluorinated carboxylic acids (PFCAs) have wide industrial applications because of their unique physicochemical characteristics. However, data on the toxicity of much of this chemical class is lacking, particularly with regard to mixture toxicity. In this study, the toxicity of individual PFCAs and their mixtures to Photobacterium phosphoreum were observed. There was a tendency of increasing toxicity from C3 to C14 PFCA and a tendency of decreasing toxicity from C14 to C18 PFCA because of “the maximum tolerance of the cell membrane”. Using the equivalent log K_OW (octanol–water partition coefficient) and log K_SD (C₁₈-Empore™ disks/water partition coefficient), two linear quantitative structure–activity relationship (QSAR) models were formulated. This indicated both K_SD and K_OW can describe the hydrophobicity of a single chemical. However, for the PFCA mixtures, K_MD is the more reasonable parameter than K_owmix to describe the hydrophobicity because only the equivalent log K_MD could be used to predict the mixture toxicity.     

小型猪CYP3A88基因克隆与其他动物的序列比较

目的 克隆我国资源小型猪品系巴马香猪肝脏中的CYP3A88基因,并进行生物信息学分析.方法 应用RACE(Rapid Amplification of cDNA Ends)技术对其全长进行扩增,测序,利用Internet和GenBank数据库对其序列进行生物信息学分析.结果首次克隆并鉴定了我国资源小型猪品系巴马香猪肝脏中CYP3A88(GenBank登录号:EF625347)的编码区,获得大小为1965 bp的全长cDNA,编码区长为1512bp,编码503个氨基酸;比较核苷酸序列,与小型猪CYP3A39相似性高达94%,而与人等其它动物的CYP3A相似性则在86%以下;推导和分析氨基酸序列表明,与小型猪CYP3A其它成员(CYP3A39、CYP3A29、CYP3A22)进行对比,其相似性分别为92%,89%,80%,而将小型猪与人的CYP3A分别比对,小型猪CYP3A88与人CYP3A4相似性最高,为77%;对其二级结构预测,它可能含12个α螺旋,4个β折叠;经NCBI上的CDD程序分析可知,其39-491氨基酸区域为P450 3A亚家族保守结构区域;经聚类分析,小型猪和狗的CYP3A与人有较近的进化关系;通过同源建模法对其在线建模,人CYP3A4晶体结构作为其模建模型,得到了其经典的三维结构.结论 在猪CYP3A家族四个基因中,CYP3A88在序列和高级结构上均与人CYP3A4的最为相似.