食管癌引流淋巴结细胞体外培养及其抑瘤作用的观察

目的观察食管癌引流淋巴结（TDLN）细胞体外培养结果及其抑瘤作用。方法术中切取食管癌患者的TDLN进行培养,分为3组：A组,培养基中添加IL-2;B组,添加IL-2＋IL-4＋粒—巨噬细胞集落刺激因子（GM-CSF）;C组,添加IL-2＋IL-4＋GM-CSF＋自身食管癌细胞抗原。于培养第1、7、14、21天行细胞计数;采用流式细胞技术测定TDLN细胞的CD3＋、CD4＋、CD8＋、CD5＋6、CD8＋3;MTT法测定各组TDLN细胞和淋巴因子激活杀伤（LAK）细胞对自体瘤细胞的抑瘤率。结果每1.0 g淋巴结组织培养第7、14、21天收获细胞数三组间差异不显著;A组第14天细胞明显多于第7天和第21天（P〈0.01）,第7天和第21天之间无明显差异;B组、C组结果类似。三组间CD4＋、CD8＋、CD8＋3细胞数相比,P〈0.05。未经培养的TDLN细胞、LAK细胞和各培养组TDLN细胞对自体肿瘤细胞的杀伤率有显著差异（P〈0.01）。结论TDLN细胞通过培养可以获得大量成熟树突状细胞和T细胞;培养基中添加GM-CSF和IL-4的TDLN培养后对自身肿瘤细胞的杀伤率最高。     

食管癌TDLN细胞对食管癌裸鼠移植瘤的体内抑瘤作用

目的探讨肿瘤引流区淋巴结细胞对食管癌裸鼠移植瘤的体内杀伤作用,为其临床应用提供依据。方法将30只食管癌移植瘤裸鼠模型随机分为对照组、IL-2组、LAK组、I-TDLN组及G-TDLN组。分别予生理盐水、IL-2、LAK细胞及体外培养的I-TDLN、G-TDLN细胞局部注射干预。分别于干预后1、2、3、4周测定各组肿瘤抑制率;干预后4周测定各组肿瘤细胞凋亡率;观察肿瘤组织病理学变化。结果 TDLN组各时点肿瘤抑制率均明显高于对照组、IL-2组及LAK组,G-TDLN组高于I-TDLN组（P均〈0.05）,各组肿瘤抑制率均逐渐升高,于第3周达高峰;对照组、IL-2组、LAK组、I-TDLN组、G-TDLN组细胞凋亡率依次升高,P均〈0.05。LAK组及TDLN组肿瘤组织均有T淋巴细胞和DC浸润,但TDLN组明显多于LAK组。结论体外培养的食管癌TDLN细胞在体内可抑制食管癌移植瘤生长,其机制为直接杀伤肿瘤细胞并诱导肿瘤细胞凋亡。本研究为食管癌TDLN细胞用于临床食管癌的细胞免疫治疗提供了理论依据。     

IL-2、IL-4、GM-CSF对食管癌引流淋巴结细胞生长及分泌细胞因子的影响

目的 探讨不同刺激剂对食管癌肿瘤引流淋巴结(TDLN)细胞生长和分泌细胞因子的影响.方法 术中切取TDLN进行培养,根据培养基中添加刺激剂不同分为三组,A组:添加IL-2;B组:添加IL-2+IL-4+GM-CSF;C组:添加IL-2+IL4+GM-CSF+自身肿瘤细胞抗原(tAg).计数培养第1、7、14、21天的细胞数,采用FCM测定TDLN细胞中CD3+、CD4+、CD8+、CD56+、CD83+细胞的比例,采用ELISA和Griess法测定培养上清液中IL-12、IFN-γ、TNF-а和NO水平.结果 三组间收获细胞数相似(F=1.689,P=0.127),第14天收获细胞数明显多于第7、21天(P<0.001),第7天与第21天相似(P0.05).收获的细胞中,三组CD4+、CD8+、CD83+细胞比例差异显著(P<0.05).三组TNF-а仅水平相近(P=0.302),但在第14天明显高于第7、21天(P<0.05),第7天与第21天时相似(P0.05).三组的IFN-γ、IL-12和NO含量比较,P<0.05.三组的IFN-γ水平在培养第14、21天均明显高于第7天(P相似文献   

抗独特型抗体NP30诱导虫卵肉芽肿细胞凋亡的分子机制

目的研究抗独特型抗体NP30诱导虫卵肉芽肿细胞凋亡的分子机制.方法 BALB/c 小鼠随机分为两组,实验组腹腔注射NP30 10 μg/次,连续3次,对照组腹腔注射生理盐水,分别在尾蚴攻击感染后第39、49、64、108、112天处死,应用免疫组化S-P法检测凋亡相关基因Bax、Bcl-2、Fas、FasL和c-Fos的表达,原位分子杂交检测Bax与Fas mRNA.结果虫卵肉芽肿细胞均表达Bax、Fas、FasL和c-Fos蛋白,其中实验组Bax和FasL蛋白表达均高于对照组(P<0.05);实验组Fas和c-Fos蛋白表达在第64天和第112天低于对照组,其余各时间点均高于对照组(P<0.05);Bcl-2蛋白在实验组和对照组均无表达.实验组Bax和fas mRNA表达均高于对照组.结论死亡受体Fas和FasL途径启动了NP30诱导肉芽肿细胞凋亡的信号,NP30通过凋亡相关基因Bax和c-Fos表达增强来诱导肉芽肿的细胞凋亡.     

益气活血软坚解毒方含药血清诱导人肝癌细胞系Bel-7402细胞凋亡过程中部分凋亡调控基因变化

目的:研究益气活血软坚解毒方(YHRJ)含药血清对人肝癌细胞系Bel-7402细胞凋亡调控基因Fas,FasL,Bcl-2,Bax,P53,NF-kB表达影响.方法:将细胞分为对照组(NS)组、NS DDP(顺氯氨铂)组、YHRJ等剂量组(YHRJD)、YHRJD DDP组、YHRJ高剂量组(YHRJG)、YHRJG DDP组,应用流式细胞术、免疫组化、原位杂交、RT-PCR等方法对用药24,48h的Bel-7402细胞凋亡的主要调控基因Fas,FasL,Bcl-2,Bax,P53,NF-kBmRNA与蛋白表达进行检测.结果:流式细胞术检测显示:与NS组相比,NS DDP、YHRJD、YHRJD DDP及YHRJG DDP组Fas蛋白表达均明显提高(30.12%±22.94%,10.50%±8.41%,30.35%±22.98%,32.61%±26.87%vs8.77%±6.93%,P<0.01),YHRJG组效果不明显(P>0.05);NS DDP、YHRJD DDP组FasL蛋白表达也升高(16.40%±7.168%,8.41%±6.74%vs4.12%±2.60%,P<0.01),而YHRJG组FasL蛋白表达降低(3.05%±2.53%vs4.12%±2.60%,P<0.01).免疫组化结果显示:除YHRJG DDP组外,其余各组突变型P53蛋白表达明显降低(30.2%,14.6%,19.8%,17.3%vs60.0%,P<0.05);各加药组Bax蛋白表达明显增高(40.7%,40.4%,72.1%,68.9%,42.2%vs30.0%,P<0.05);NS DDP组与YHRJG组Bcl-2蛋白表达明显降低(26.3%,24.4%vs30.5%,P<0.05),而YHRJD、YHRJG DDP、YHRJG DDP组Bcl-2表达明显升高(41.8%,39.3%,45.6%vs30.5%,P<0.05);各加药组NF-kB蛋白表达明显降低(15.9%,13.3%,14.1%,7.8%,14.6%vs24.2%,P<0.05).原位杂交结果显示:各加药组NF-kBmRNA表达明显降低(30.5%,13.3%,21.4%,17.4%,53.2%vs58%,P<0.05).RT-PCR结果显示:YHRJ等效剂组凋亡调控基因Bcl-2mRNA表达明显降低(0.717±0.198vs1.327±0.097,P<0.001);DDP、YHRJD、YHRJG组凋亡调控基因BaxmRNA表达明显增高(46.22±6.22,56.19±7.36,62.32±11.06vs35.22±4.38,P<0.05).结论:YHRJ含药血清诱导人肝癌细胞系Bel-7402细胞凋亡可能的基因调控机制在于通过抑制凋亡信号转导基因FasL基因蛋白表达,促进凋亡调控基因Bax基因蛋白表达,抑制NF-kB基因mRNA及蛋白表达来实现的.     

赤芍总苷对人黑色素瘤细胞株凋亡诱导的作用机制

目的 观察赤芍总苷(TPG)对人黑色素瘤A375细胞凋亡的影响并探讨其机制.方法 将12.5、25、50、100、200 mg/L TPG分别加入体外培养的黑色素瘤细胞,对照组加等量生理盐水,孵育24、48 h后MTT测定细胞生长抑制率;25 mg/L TPG 孵育细胞48 h,收集细胞,FCM测定细胞凋亡率;RT-PCR和Western blot分别测定Caspase-3、Bcl-2、Bax、Fas、FasL mRNA和蛋白的表达水平.结果 TPG抑制A375细胞生长作用明显,25 mg/L TPG孵育黑色素瘤细胞48 h后,细胞凋亡率增高,Caspase-3、Bax、Fas、FasL mRNA和蛋白表达也明显升高,Bcl-2 mRNA和蛋白表达水平下降,Bcl-2/Bax比值显著降低(均P＜0.05).结论 TPG可诱导黑色素瘤肿瘤细胞凋亡,其机制与上调Caspase-3、Fas和FasL表达水平,下调Bcl-2,降低Bcl-2/Bax比值密切相关.     

Graves病患者甲状腺组织中凋亡蛋白Fas、FasL、Bcl-2和Bax的表达

目的　探讨凋亡调节蛋白Fas、FasL、Bcl 2和Bax与Graves病 (GD)发病机制的关系。方法采用免疫组织化学法检测 5 4例GD和 10例正常甲状腺组织Fas、FasL、Bcl 2、Bax表达 ,应用Mias 99图像分析系统对检测结果进行定量分析。结果　 (1)GD甲状腺细胞Fas、FasL、Bcl 2及Bax表达增高 ,其阳性颗粒面积、平均光密度及积分光密度均明显高于正常甲状腺 (均P <0 .0 1) ;(2 )GD组甲状腺组织Bcl 2阳性颗粒面积、平均光密度及积分光密度均高于Bax(P <0 .0 1) ,而正常甲状腺Bcl 2阳性颗粒面积及积分光密度与Bax比较差异无显著性 ;(3 )Bcl 2阳性颗粒面积及积分光密度与Bax的比值 ,GD组明显高于正常对照组 ;(4 )GD甲状腺浸润淋巴细胞亦表达一定水平的Fas、FasL、Bcl 2、Bax ,但明显低于同组甲状腺细胞(均P <0 .0 1)。结论　Fas、FasL、Bcl 2及Bax表达异常尤其是Bcl 2高表达导致的甲状腺细胞和浸润淋巴细胞凋亡减少可能与GD甲状腺体积增大、功能亢进有关。     

桥本甲状腺炎甲状腺组织中Fas、Fas配体、Bcl-2、Bax表达及意义

目的　探讨细胞凋亡相关蛋白Fas、Fas配体 (FasL)、Bcl 2、Bax表达与桥本甲状腺炎(HT)发病机制的关系。方法　采用免疫组化S P法检测 41例HT和 10例正常甲状腺组织Fas、FasL、Bcl 2、Bax表达及分布 ,应用Mias99图像分析系统进行定量分析。结果　 (1)HT组甲状腺组织中Fas、FasL、Bcl 2、Bax阳性染色面积、平均光密度和积分光密度均显著高于正常组 (P <0 .0 1) ;(2 )HT组中组织结构破坏较重区域中小滤泡及失去正常滤泡结构的腺上皮Fas、FasL、Bax表达高于其它腺上皮 ,滤泡结构较完整的区域Bcl 2表达较高。结论　Fas、FasL、Bcl 2、Bax的过度表达可能参与HT发病过程 ,其导致的细胞凋亡增高可能是HT甲状腺细胞破坏的重要机制之一 ;Bcl 2在维护HT甲状腺滤泡结构的完整性中起着某种重要作用     

高脂血症对急性坏死性胰腺炎大鼠胰腺NF-κB活化及腺泡细胞凋亡的影响

目的 探讨高脂血症对急性坏死性胰腺炎(ANP)大鼠胰腺组织病理损伤程度、NF-κB活化及胰腺腺泡细胞凋亡的影响.方法 50只雄性SD大鼠随机分成对照组、高脂血症组(HL组)、ANP组及HL+ANP组.对照组予均衡饲料喂养2周,仅开、关腹;HL组脂肪乳灌胃2周后开、关腹;ANP组予均衡饲料喂养2周后采用胰胆管注射牛磺胆酸钠制备ANP模型;HL+ANP组在脂肪乳灌胃2周后制备ANP模型.免疫组化法检测胰腺组织NF-κBp5及Fas、FasL蛋白表达,TUNEL法检测胰腺腺泡细胞凋亡.结果 HL组和HL+ANP组大鼠的血脂明显升高.HL组胰腺见部分细胞有脂质空泡形成,中等量炎症细胞浸润;NF-κB活化轻度增强;凋亡蛋白Fas、FasL表达也有所增强;凋亡指数从(0.62±0.28)%增加到(3.35±1.12)%.ANP组胰腺大片坏死,大量炎症细胞浸润;大量腺胞细胞核有NF-κBp65表达;Fas与FasL表达亦明显增强;凋亡指数为(2.20±1.78)%.HL+ANP组的胰腺坏死较ANP组更严重(3.4±0.7比2.4±1.1,P<0.05),NF-κB p65的表达阳性率及强度较ANP组更高;Fas与FasL的表达较ANP组有所减弱;凋亡指数为(0.93±0.87)%,较ANP组明显降低(P<0.05).结论 高血脂能增强ANP大鼠胰腺NF-κB的活化,抑制腺泡细胞的凋亡,减少Fas与FasL的表达,加重胰腺组织坏死,故必须控制高血脂以减轻胰腺炎的损伤程度.     

自身免疫性甲状腺疾病甲状腺组织中凋亡调控蛋白Fas/FasL、Bcl-2/Bax的表达及意义

目的探讨凋亡调控蛋白Fas/FasL、Bcl-2/Bax在Graves病(GD)和桥本氏病(HT)中的表达及意义。方法取外科手术切取的GD及HT病人甲状腺组织标本,颈部手术时取正常甲状腺组织作为对照;采用免疫组织化学方法检测甲状腺标本Fas/FasL、Bcl-2/Bax的表达和分布状况。结果(1)Fas/FasL在GD和HT甲状腺滤泡上皮细胞表达均较正常对照组增高(P<0.01)。(2)在GD甲状腺滤泡上皮细胞Bcl-2及Bax表达明显高于HT组及正常对照组,以Bcl-2表达强度显著高于同组Bax(P<0.01),而在HT,Bcl-2表达强度与正常对照组比较差异无统计学意义。(3)GD与HT相比较,GD甲状腺滤泡细胞及浸润淋巴细胞Fas,Bcl-2抗原表达均强于HT,但其浸润淋巴细胞表达强度明显低于同组甲状腺滤泡细胞(均P<0.05)。结论Fas/FasL高表达和Bcl-2的低表达可能引起HT甲状腺滤泡上皮细胞的凋亡。在GD,Fas、Bax诱导细胞凋亡的作用可能被高表达Bcl-2对抗,从而致甲状腺体积增大、功能亢进。此外,Bcl-2与Bax表达强度的比值对于凋亡的调控有重要影响作用。     

Release of protein A from the cell wall of Staphylococcus aureus

Staphylococcal protein A (SpA) is anchored to the cell wall envelope of Staphylococcus aureus by sortase A, which links the threonyl (T) of its C-terminal LPXTG motif to peptidoglycan cross-bridges (i.e., Gly₅). SpA binds the Fcγ domains of IgG and protects staphylococci from opsonophagocytic clearance. Moreover, SpA cross-links B-cell receptors to modify host adaptive immune responses. The mechanisms whereby SpA is released from the bacterial surface to access the host’s immune system are not known. Here we demonstrate that SpA is released with murein tetrapeptide-tetraglycyl [l-Ala-d-iGln-(SpA-Gly₅)l-Lys-d-Ala-Gly₄] linked to its C-terminal threonyl. LytN, a cross-wall murein hydrolase, contributes to the release of SpA by removing amino sugars [i.e., N-acetylmuramic acid-N-acetylglucosamine (MurNAc-GlcNAc)] from attached peptidoglycan, whereas LytM, a pentaglycyl-endopeptidase, triggers polypeptide release from the bacterial envelope. A model is proposed whereby murein hydrolases cleave the anchor structure of released SpA to modify host immune responses.The Gram-positive bacterium Staphylococcus aureus is a pathogen of humans (1). Cells of S. aureus are surrounded by a thick layer of highly cross-linked cell wall peptidoglycan (2). The peptidoglycan layer is formed from lipid II precursors, C₅₅-(PO₃)₂-N-acetylmuramic acid (MurNAc)-(l-Ala-d-iGln-(Gly₅)l-Lys-d-Ala-d-Ala)-GlcNAc (3), via the transpeptidation and transglycosylation reactions of cell wall synthesis to generate [MurNAc-(l-Ala-d-iGln-(Gly₅)l-Lys-d-Ala)-GlcNAc]_n polymer (4). Assembled peptidoglycan is a single large macromolecule that protects bacteria against osmotic lysis (5) and also functions as scaffold for the anchoring of wall teichoic acids (6) and proteins (7). These secondary cell wall polymers promote specific interactions between staphylococci and host tissues (8). Cell wall-anchored surface proteins are synthesized as precursors with N-terminal signal peptides and C-terminal LPXTG motif sorting signals (9). Following cleavage of the N-terminal signal peptide by signal peptidase, the C-terminal sorting signal is cleaved by sortase A between the threonyl (T) and the glycyl (G) of the LPXTG motif (10). Sortase A forms an acyl enzyme, capturing the C-terminal carboxyl group of cleaved surface proteins with its active site cysteine thiol (11). These acyl intermediates are relieved by the nucleophilic attack of the amino group of pentaglycyl within lipid II and incorporated into the cell wall via the transpeptidation and transglycosylation reactions (7, 12).The genomes of S. aureus isolates harbor 17 to 22 genes encoding LPXTG motif surface proteins, which can be further classified as precursors with canonical or YSIRK-G/S signal peptides (13). Surface proteins with canonical signal peptides are secreted and immobilized to peptidoglycan near the cell poles of dividing staphylococci (14). In contrast, precursors with YSIRK-G/S signal peptides are secreted into the cross-wall, a membrane enclosed compartment for the de novo synthesis of peptidoglycan that separates daughter cells during division (14). When precursors with YSIRK-G/S signal peptides and LPXTG motif sorting signals have been deposited at the cross-wall and its peptidoglycan has been split, surface proteins are displayed over the staphylococcal surface (14). YSIRK-G/S precursors include proteins with important virulence functions that are synthesized in large abundance, including clumping factor A (15), fibronectin binding proteins (16, 17), iron-regulated surface protein B (18), and staphylococcal protein A (SpA) (19).SpA binds human or animal Ig via its Ig-binding domains that capture the Fcγ domain of IgG or the Fab domain of V_H3-clan IgG and IgM antibodies (20, 21). SpA binding to the Fcγ domain blocks the ability of antibodies with specific binding activities for the staphylococcal surface to promote Fc receptor-mediated opsonophagocytosis and bacterial killing (22). SpA binding to the Fab domain of V_H3-clan IgM triggers B-cell receptor cross-linking and clonal expansion of B lymphocytes, which eventually undergo apoptotic collapse (23). During infection, this B-cell superantigen activity of SpA ablates host adaptive immune responses against many staphylococcal antigens (24). Although S. aureus disease predominantly manifests as localized skin or soft-tissue infection, its suppressive effects on the immune system appear to be general (25). If so, we wondered whether SpA, a key factor for staphylococcal immune evasion, is released from the bacterial surface.     

丙型肝炎病毒不同基因型核心蛋白对肝母细胞瘤细胞凋亡影响的比较

目的比较HCV不同基因型核心蛋白(core)在肝母细胞瘤细胞凋亡中的作用。方法构建6a基因型HCV core的表达载体pcDNA3.1/myc-His(-)-core(6a)[pCore(6a)];分别将1b、3a和6a基因型HCV core质粒以及空质粒pcDNA3.1/myc-His(-)(pNC)瞬时转染HepG2细胞,48小时后利用流式细胞术检测细胞凋亡发生的情况;利用Real-time PCR检测胱冬肽酶-3的mRNA水平变化;利用化学发光法检测胱冬肽酶-3的活性变化,比较HCV不同基因型core对细胞凋亡作用的差异。结果成功构建了6a基因型HCV core的表达载体pcDNA3.1/myc-His(-)-core(6a)[pCore(6a)];与pNC组相比,表达1b、3a和6a基因型HCV core的HepG2细胞中,Annexin V+细胞数均显著减少,其中6a基因型core较1b和3a基因型core作用显著(P=0.000、0.001);同时实验组中凋亡效应分子胱冬肽酶-3的mRNA水平及其活性较对照组均降低;其中与1b和3a基因型core相比较,6a基因型core显著降低胱冬肽酶-3的mRNA水平,而在抑制胱冬肽酶-3活性方面无显著差别。结论 HCV不同基因型core对细胞凋亡的作用不同;基因6a型core对细胞凋亡的抑制作用更为显著;HCV基因6型核心蛋白可能更易导致肝癌的发生,有待进一步研究。     

急性时相反应蛋白与小细胞肺癌预后相关分析研究

目的 C反应蛋白(CRP)是一种急性时相反应蛋白,除了在机体急性损伤感染时的作用得到公认外,升高的急性时相反应蛋白与多种组织类型的非小细胞肺癌差的预后相关.本研究旨在调查治疗前血CRP对神经内分泌肿瘤小细胞肺癌预后的影响.方法 回顾性分析2007年至2010年间初治的小细胞肺癌125例,随访并对可能影响预后的因素进行分析.结果 125例小细胞肺癌患者中有79例(63.2％)治疗前血CRP正常(＜10 mg/L),46例(36.8％)患者血CRP值升高(≥10 mg/L).治疗前血清CRP值的升高与患者的ECOG PS评分(P=0.037)、肿瘤最大直径(P=0.034)、肿瘤分期(P =0.015)、治疗前血清白蛋白(P=0.024)相关.治疗前血CRP值正常的患者中位生存期为13.470个月,而血CRP值≥10 mg/L的患者中位生存期仅为9.780个月,两者差异有统计学意义(P=0.047).单因素分析显示:治疗前血清CRP值(P=0.047)、ECOG PS评分(P=0.017)、疾病分期(P=0.024)、治疗前白蛋白值(P =0.012)、化疗周期数(P=0.034)与患者的预后相关.应用Logistic回归分析上述多因素,结果发现治疗前血清CRP值升高(HR=1.525,P=0.037)、ECOG PS评分高(HR =1.904,P =0.015)、疾病分期晚(HR =1.798,P=0.004)、治疗前白蛋白水平低下(HR =1.542,P=0.038)是导致患者预后差的独立因子.结论 对于小细胞肺癌患者,CRP的存在及强度是独立的预后因素,与患者的功能状态评分、疾病分期、肿瘤大小、低蛋白血症有关.系统性炎症反应越强烈,CRP水平越高,患者的生存预后越差.     

Enforced Bcl-2 expression overrides serum and feeder cell requirements for mouse embryonic stem cell self-renewal

Leukemia inhibitory factor (LIF) is required, but not sufficient, for pluripotent mouse embryonic stem (ES) cell expansion in vitro in the absence of serum or a feeder cell layer, suggesting that additional signals are provided by serum or feeders that are necessary to support self-renewal. Here we show that transgenic ES cell lines expressing Bcl-2, an antiapoptotic protein, continue to self-renew in serum- and feeder-free conditions when supplemented with LIF; even in the absence of bone morphogenic proteins. Bcl-2-expressing clones sustain the characteristics of undifferentiated, pluripotent ES cells during long-term culture, and maintain their potential to differentiate into mature cell types. These results suggest that LIF and Bcl-2 overexpression are sufficient to expand these mouse pluripotent stem cells in vitro.     

Two-component protein-engineered physical hydrogels for cell encapsulation

Current protocols to encapsulate cells within physical hydrogels require substantial changes in environmental conditions (pH, temperature, or ionic strength) to initiate gelation. These conditions can be detrimental to cells and are often difficult to reproduce, therefore complicating their use in clinical settings. We report the development of a two-component, molecular-recognition gelation strategy that enables cell encapsulation without environmental triggers. Instead, the two components, which contain multiple repeats of WW and proline-rich peptide domains, undergo a sol–gel phase transition upon simple mixing and hetero-assembly of the peptide domains. We term these materials mixing-induced, two-component hydrogels. Our results demonstrate use of the WW and proline-rich domains in protein-engineered materials and expand the library of peptides successfully designed into engineered proteins. Because both of these association domains are normally found intracellularly, their molecular recognition is not disrupted by the presence of additional biomolecules in the extracellular milieu, thereby enabling reproducible encapsulation of multiple cell types, including PC-12 neuronal-like cells, human umbilical vein endothelial cells, and murine adult neural stem cells. Precise variations in the molecular-level design of the two components including (i) the frequency of repeated association domains per chain and (ii) the association energy between domains enable tailoring of the hydrogel viscoelasticity to achieve plateau shear moduli ranging from ≈9 to 50 Pa. Because of the transient physical crosslinks that form between association domains, these hydrogels are shear-thinning, injectable, and self-healing. Neural stem cells encapsulated in the hydrogels form stable three-dimensional cultures that continue to self-renew, differentiate, and sprout extended neurites.     

The cell biology of the unfolded protein response

The unfolded protein response (UPR) is an ensemble of signal transduction pathways that respond to perturbations in the oxidative, pro-folding environment of the endoplasmic reticulum. During the past decade, ongoing research implicated these pathways in maintaining homeostasis of cells and organisms exposed to various stresses. Herein, we highlight recent findings regarding the functional role of the UPR in both normal and pathophysiologic processes.     

Programmed death ligand-1 expression and its prognostic role in esophageal squamous cell carcinoma

AIM To investigate the expression and prognostic role of programmed death ligand-1(PD-L1) in locally advanced esophageal squamous cell carcinoma(ESCC).METHODS A total of 200 patients with ESCC who underwent radical esophagectomy with standard lymphadenectomy as the initial definitive treatment in Seoul National University Hospital from December 2000 to April 2013 were eligible for this analysis. Tissue microarrays were constructed by collecting tissue cores from surgical specimens, and immunostained with antibodies directed against PD-L1, p16, and c-Met. Medical records were reviewed retrospectively to assess clinical outcomes. Patients were divided into two groups by PD-L1 status, and significant differences in clinicopathologic characteristics between the two groups were assessed. RESULTS Tumor tissues from 67 ESCC patients(33.5%) were PDL1-positive. Positive p16 expression was observed in 21 specimens(10.5%). The H-score for c-Met expression was ≥ 50 in 42 specimens(21.0%). Although PDL1-positivity was not significantly correlated with any clinical characteristics including age, sex, smoking/alcoholic history, stage, or differentiation, H-scores for c-Met expression were significantly associated with PDL1-positivity(OR = 2.34, 95%CI: 1.16-4.72, P = 0.017). PD-L1 expression was not significantly associated with a change in overall survival(P = 0.656). In contrast, the locoregional relapse rate tended to increase(P = 0.134), and the distant metastasis rate was significantly increased(HR = 1.72, 95%CI: 1.01-2.79, P = 0.028) in patients with PD-L1-positive ESCC compared to those with PD-L1-negative ESCC.CONCLUSION PD-L1 expression is positively correlated with c-Met expression in ESCC. PD-L1 may play a critical role in distant failure and progression of ESCC.     

血栓调节素-活化蛋白C-内皮细胞蛋白C受体系统抗炎症作用研究进展

血栓调节素-活化蛋白C-内皮细胞蛋白C受体(TM-APC-EPCR)系统除具有传统的抗血栓、促纤溶特性外,最近的研究认为其还在炎症反应过程中相互协调整合,参与抗炎和抗凋亡作用,防止组织细胞受损,发挥保护作用.目前认为该系统作为炎症反应中的重要调节因素,将成为判断严重炎症疾病预后的指标和炎症治疗进程中的新靶点.