半乳糖凝集素3对内皮细胞生长、迁移及炎症反应的影响

目的:探讨半乳糖凝集素3(GAL-3)对人脐静脉内皮细胞(HUVECs)生长、迁移及炎症反应的影响及其作用机制。方法:体外培养HUVECs,给予GAL-3重组蛋白2 mg/L或GAL-3短发夹RNA(shRNA)慢病毒载体处理,实验分为正常对照组、GAL-3重组蛋白处理组、阴性对照组和GAL-3-shRNA组。通过实时荧光定量PCR检测GAL-3、单核细胞趋化蛋白1(MCP-1)、IL-6、基质金属蛋白酶9(MMP-9)和cyclin D1的mRNA水平;利用Western blot检测GAL-3、MCP-1和IL-6的蛋白表达;利用ELISA检测MCP-1和IL-6在培养基中的水平;通过CCK-8实验和划痕实验检测HUVECs的活力和迁移能力;利用Western blot检测信号分子热休克蛋白90(HSP90)、ERK1/2、p-ERK1/2、JNK和p-JNK的蛋白水平。结果:首先,给予GAL-3重组蛋白处理后,GAL-3、MCP-1和IL-6的mRNA及蛋白水平,MMP-9和cyclin D1的mRNA水平,MCP-1和IL-6在培养基的分泌水平均明显高于正常对照组;而GAL-3-shRNA感染细胞后,上述分子的表达水平均低于正常对照组和阴性对照组。其次,GAL-3重组蛋白处理后,细胞活力和迁移能力明显高于正常对照组;而GAL-3-shRNA感染后,细胞活力和迁移能力均低于正常对照组和阴性对照组。此外,GAL-3重组蛋白处理组中,p-ERK1/2和HSP90的蛋白水平高于正常对照组;而GAL-3-shRNA组中,p-ERK1/2和HSP90的蛋白水平均低于正常对照组和阴性对照组。p-JNK的蛋白水平在各组间比较,差异无统计学显著性。结论:GAL-3促进血管内皮细胞的生长、迁移及炎症反应的发生,其机制可能与HSP90-ERK1/2信号通路有关。     

供体年龄影响融合生长内皮祖细胞对平滑肌细胞表型转换及增殖迁移的作用

目的:探讨老龄和年轻个体来源融合生长状态内皮祖细胞(EPCs)对血管平滑肌细胞(SMCs)表型转换以及增殖和迁移的调节作用。方法:脱臼处死1~2月龄、19~26月龄SD大鼠,应用含15%FBS的DMEM/F12培养基(含内皮细胞生长添加剂100 mg/L、肝素100 mg/L、青霉素、链霉素各1×105U/L)培养EPCs,取1~2月龄大鼠腹主动脉,组织块法培养血管SMCs,应用Di I-Ac-LDL与FITC-UEA-1荧光双染以及α-SM-actin免疫荧光分别对EPCs和SMCs进行鉴定。建立细胞共培养体系,上室为融合生长状态的EPCs,下室为SMCs,实验分4组:(1)第3代SMCs(P3)组;(2)第4代SMCs(P4)组;(3)第4代SMCs与年轻大鼠来源EPCs共培养(P4YE)组;(4)第4代SMCs与老龄大鼠来源EPCs共培养(P4AE)组。Western blotting检测α-SM-actin和osteopontin蛋白的表达;[3H]-TdR掺入法检测SMCs增殖;细胞划痕实验检测SMCs的迁移能力。结果:与P3组相比,P4组的SMCsα-SM-actin表达显著下调,而osteopontin表达显著增强;P4YE组SMCs的α-SM-actin及osteopontin表达与P3组比较未见有显著差别;与P4组相比,年轻和老龄大鼠来源的EPCs均显著促进第4代SMCs的α-SM-actin和下调osteopontin的表达,抑制第4代SMCs的增殖和迁移;与老龄大鼠来源的EPCs相比,年轻大鼠来源的EPCs更能够显著延迟SMCs表型由收缩型向合成型转换,抑制SMCs增殖和迁移。结论:共培养融合生长状态的EPCs使血管SMCs表型转换延迟、抑制SMCs增殖和迁移,年轻大鼠来源的EPCs较老龄大鼠来源的EPC更显著延迟血管SMCs表型由收缩型向合成型转换,并具有更强的抑制血管SMCs增殖和迁移的能力。     

同型半胱氨酸对血管内皮细胞增殖、贴壁和迁移的影响

目的：探讨同型半胱氨酸（homocysteine，Hcy)对血管内皮细胞生长、增殖、贴壁和迁移的影响。方法:将人脐静脉内皮细胞（HUVEC，6-8代）采用含20%胎牛血清（FBS）、60 mg/ L 内皮细胞生长添加剂（endothelial cell growth supplement，ECGS)、0.005 U/ L 肝素的M199培养。在加入不同浓度的Hcy处理后，用胰酶消化细胞，白细胞计数板计数细胞；同时通过［3H］胸腺嘧啶核苷掺入实验观察Hcy对HUVEC细胞增殖的影响。此外，在加入不同浓度的Hcy处理后，用胰酶消化细胞，重新接种于纤连蛋白包被过的培养皿中，静置培养30 min，洗掉未贴壁细胞，对贴壁细胞进行固定、结晶紫染色、脱色、比色，观察Hcy对细胞贴壁的影响。并进一步通过划伤实验观察Hcy对内皮迁移的影响。结果:100 mmol/L 及以上浓度的Hcy能抑制HUVEC增殖、DNA合成和细胞迁移，200 mmol/L及以上浓度的Hcy能抑制HUVEC贴壁，并且随着剂量的加大，抑制作用都逐渐增强。结论:Hcy对HUVEC细胞增殖、DNA合成、细胞迁移及贴壁均有着不同程度的抑制作用。这可能是Hcy参与动脉粥样硬化发病的机制之一。     

粘着斑激酶在血管内皮细胞黏附和迁移中的作用

目的 采用粘着斑激酶（focal adhesion kinases,FAK)抑制剂抑制FAK在Y397位点的酪氨酸磷酸化,测定不同浓度的FAK抑制剂的对内皮细胞黏附、迁移及下游信号Rac1蛋白表达的影响,探索粘着斑激酶在内皮细胞黏附和迁移中的作用。方法 运用内皮损伤模型（划痕法）测定FAK抑制剂在2、4、8、24 h各时间点对EA.hy 926细胞迁移的影响。Western blot结合免疫荧光测定不同浓度的0~250 nmol/mL的FAK抑制剂的加入对Rac1蛋白分布和表达的影响。结果 随着FAK抑制剂浓度的增加,细胞迁移距离减少,Rac1蛋白表达逐渐减弱。结论 抑制FAK的磷酸化将抑制内皮细胞的黏附和迁移的生物学行为,下游Rac1蛋白表达降低。内皮细胞的黏附和迁移与FAKRho GTPases 信号轴相关。     

内皮细胞Rho及Rho激酶在肉瘤细胞向血管外游走过程中的作用

目的:探讨肉瘤细胞向血管外游走过程中内皮细胞Rho及Rho激酶的作用。方法: 利用肉瘤细胞向血管外游走的体外模型,观察肉瘤细胞的血管外游走状况;并测定肉瘤细胞向血管外游走过程中血管内皮单细胞层的电阻变化。结果:肉瘤细胞可以穿过血管内皮细胞游走至血管外;肉瘤细胞向血管外的游走能够引起单层血管内皮细胞的电阻下降;而内皮细胞Rho抑制剂(C3转移酶)及Rho激酶抑制剂(Y-27632)能够抑制肉瘤细胞向血管外的游走、并抑制游走过程中引起的血管内皮单细胞层电阻下降。结论: 内皮细胞Rho及Rho激酶可以通过诱导血管内皮细胞骨架蛋白的改变,来影响肉瘤细胞穿过内皮细胞间缝隙向血管外游走。     

内皮细胞Jagged1下调促进PDGF诱导的大鼠平滑肌细胞增殖迁移

目的： 探讨内皮细胞Jagged1表达对PDGF诱导的大鼠血管平滑肌细胞增殖迁移的调节作用。方法: 分离培养大鼠主动脉内皮和平滑肌细胞,将内皮接种于下室、平滑肌接种于上室建立细胞共培养体系,根据内皮是否行Jagged1小RNA干扰分为对照组、空载体组和Jagged1小RNA干扰组。用Western blotting检测内皮细胞Jagged1的干扰效率。于下室加入PDGF（10 μg/L）干预24 h后分别用［3H］-TdR 掺入和平滑肌迁移计数检测平滑肌细胞增殖迁移能力,用Western blotting检测平滑肌细胞α-SM-actin蛋白表达。结果: 与对照组相比空载体组内皮细胞Jagged1蛋白表达无明显差异,Jagged1小RNA干扰组内皮细胞Jagged1蛋白吸光度相对值明显降低（0.26±0.02 vs 0.67±0.02, P<0.05）;PDGF+空载体组平滑肌［3H］-TdR 掺入量和迁移数与PDGF组相比无明显差异,PDGF+Jagged1小RNA干扰组平滑肌［3H］-TdR 掺入量和迁移数高于PDGF组{［3H］-TdR 掺入(23 074±2 702)counts·min-1·well-1 vs (16 442±1 803)counts·min-1·well-1,n=5,P<0.05;迁移(27±4)cells/field vs (15±3) cells/field, n=5,P<0.05};PDGF+空载体组平滑肌α-SM-actin蛋白表达与PDGF组相比无明显差异,PDGF+Jagged1小RNA干扰组平滑肌α-SM-actin吸光度相对值低于PDGF组（0.25±0.06 vs 0.49±0.04, n=3,P<0.05）。结论: 内皮细胞Jagged1下调促进PDGF诱导的平滑肌细胞增殖迁移,提示血管内皮细胞Jagged1表达在维持平滑肌收缩表型、抑制平滑肌过度增殖迁移中起一定调控作用。     

Vascular endothelial cells migrate centripetally within embryonic arteries

Summary Migration of vascular endothelial cells was traced in quail-chick chimeras. After heterospecific transplantations of quail limb bud pieces, or other tissues containing blood vessels, into the limbs or the coelomic cavity, the immunohistochemically stained endothelial cells of the quail were found to invade the chick host vessels, favouring the arteries. Within these vessels the endothelial cells regularly reach the host aorta, where they contribute to the endothelium on the ipsilateral side. It is concluded that the endothelial cells activity migrate, because microinjections of a synthetic peptide which contains the RGD-sequence and mimics fibronectin, stop the invasion of endothelial cells.Supported by the Dutch Heart Foundation, The Netherlands Organization for Pure Research N.W.O., the Jo Keurfonds, the Drie Lichten and the Deutsche Forschungsgemeinschaft (Ch 44/9-1)     

人外周血内皮祖细胞的分离、培养和扩增

目的:改进从人外周血中分离、培养和体外扩增血管内皮祖细胞(EPC)的方法。方法:采用不同淋巴细胞分离液,用密度梯度离心法从外周血分离EPC;用CD34免疫磁性活化细胞分选系统(MACS)分离CD34 细胞;分别培养在包被和不包被有人纤维连接蛋白(HFN)的培养板内;采用细胞免疫化学法检测内皮细胞表面标志CD31、CD34和vWF的表达。结果:从成人外周血可分离获得EPC;不同的分离条件可影响获得EPC的数量和质量,HFN对EPC的生长有促进作用。结论:进一步改进从人外周血分离获取EPC并行体外扩增的方法,为EPC的研究奠定了基础。     

Edge cell migration in the extraembryonic mesoderm of the chick embryo

Summary The expansion of the extraembryonic mesoderm was investigated in chick embryos of 2 and 3 days incubation with special regard to the mesodermal edge cells. These cells are lying immediately distal to the sinus terminalis and have the shape of migrating cells. By SEM examination they appear to be linked together to form a uniform edge which extends numerous spike-like filopodia. The shape of these filopodia corresponds to their microtubule pattern, as shown by immunofluorescence staining. Filopodia contain strong bundles of microtubules. By in vivo observation at high magnification, the migration of edge cells was demonstrated, and the results of SEM and immunofluorescence studies could be confirmed. By local application of cytochalasin D, distal to the region of the sinus terminalis, the migration of edge cells was inhibited selectively. Subsequent to the inhibition of migration, the expansion of the mesoderm stopped although the interstitial growth of the mesoderm in drug-treated regions remained unaffected. Thus the edge cells have a promotor function in the expansive growth of the extraembryonic mesoderm. The proliferating mesoderm, located proximally to the edge cells, has no expansive tendency of its own. The selectivity of the cytochalasin effect was checked by examination of the phalloidin stained actin pattern. Furthermore, by in vivo observations at low magnification and by transplantation of endoderm from quail to chick it could be confirmed that the extraembryonic mesoderm spreads out invasively between ectoderm and endoderm separating the two sheets. The promotion of this invasion can be regarded as an additional function of the edge cells. An expansion of the mesoderm can also be observed after endoderm removal. In regions freed from endoderm the mesoderm expands faster than in adjacent regions still covered by endoderm. There is no promoting influence of endoderm on mesodermal expansion. On the contrary, expansion itself is facilitated, when the conditions for invasion are abolished by removing the endoderm.     

The migration of myogenic cells from the somites into the leg region of avian embryos

The migration of myogenic stem cells into the leg anlagen of chick embryos between stages 16--20 of Hamburger and Hamilton was examined. SEM and TEM studies reveal that cell migration starts at stage 16 from the just-formed somites 26-28. The migrating myogenic cells are elongated and oriented in a medio-lateral direction. The leading ends branch into filopodia which contact a fibrillar network. At first, single cells migrate; later on the cells leaving the ventro-lateral edge of the dermatome migrate in strands and have specialized contacts between them. After reaction with ruthenium red and concanavalin A the migrating cells show a thick surface coat to which ruthenium red-positive particles are attached. The surface coat may be important in the interactions among the migrating cells as well as between the cells and the substrate. The migration of myogenic stem cells was found to take place in a matrix of collagenous fibrils and ruthenium red-positive particles, probably containing glycosaminoglycans. At the onset of migration the fibrillar network exhibits a preferred medio-lateral orientation. Therefore, it may be concluded that this alignment of the fibrils influences the direction of cell migration.     

SLeX对肝癌HepG2细胞迁移和侵袭的影响

目的:探讨唾液酸化路易斯寡糖X(sialyl Lewis X,SLeX)在肝癌HepG2细胞中的表达及其对HepG2细胞迁移能力和侵袭能力的影响。方法:实时荧光定量PCR和Western blot法检测α1,3-岩藻糖基转移酶Ⅶ(α1,3-fucosyltransferase Ⅶ,FUT7)在HepG2细胞和L-02细胞中的表达,Western blot及免疫细胞化学染色检测SLeX在HepG2细胞和L-02细胞中表达,应用Transwell小室检测SLeX单克隆抗体封闭后HepG2细胞侵袭和迁移能力的改变。结果:FUT7和SLeX在HepG2细胞中表达,而在L-02细胞中无表达;0.05、0.5和5 mg/L的SLeX单克隆抗体封闭后,HepG2细胞的迁移率逐渐下降,与对照组相比差异显著(P0.05),侵袭穿膜细胞数明显少于对照组(P0.05);SLeX单克隆抗体封闭组间两两比较迁移率与侵袭细胞数的差异均有统计学意义(P0.05)。结论:SLeX在肝癌HepG2细胞中高表达,与HepG2细胞迁移能力和侵袭能力密切相关。     

Development of the nuclei and cell migration in the medulla oblongata

Summary We have tried to obtain new insight into the development of the medulla oblongata by using the quail-to-chick chimera system. Five types of isotopic and isochrome grafts were carried out, between quail and chick embryos, at the 10- to 12-somite stage: exchanges of (I) the entire myelencephalon, (II) the dorsal half of the myelencephalon, (III) the ventral half of the myelencephalon, (IV) the right half of the myelencephalon and (V) the dorsal quarter of the myelencephalon. Before analyzing the chimeric embryos, we studied the ontogeny of the various nuclei in the medulla oblongata of normal birds. The first appearance of nuclei in quail embryos preceded in many cases that of their chick counterpart by 12 to 24 h. The adult pattern of the nuclei was established by E8 in quail and E9 in chick. Similarly, during early development of chimeras, the migration of quail cells began earlier than that of chick cells. This shows that the species specific temporal sequence of proliferation and migration is not significantly altered by transplantation into the host. The possibility of grafting selectively the ventral or dorsal half of the neural tube allowed us to distinguish the fate of the cells belonging respectively to the alar and the basal plate. The nuclei with a total or partial motor function, such as the nucleus nervi abducentis, the nucleus nervi facialis, the nucleus nervi glossopharyngei and the nucleus motorius dorsalis nervi vagi, have either an exclusive or predominant origin from the basal plate. In contrast, the nuclei with essentially or exclusively sensory components (i.e., nucleus angularis, nucleus laminaris, nucleus magnocellularis) arise from the alar plate. The reticular formation such as the nucleus reticularis gigantocellularis and the nucleus reticularis subtrigeminalis was strikingly mixed, with both alar and basal plate origin of neurons. Active dorsoventral migrations of cells originating migrations from the dorsal neural tube, the rhombic lip, contribute the ventral nuclei (i.e., nuclei pontis medialis, lateralis and olivaris inferior), whose functions are essentially associative. This study shows different types of cell migration. Dorsoventral and ventrodorsal movements are essentially active from E5 to E8. In the medulla oblongata, the dorsoventral stream is highly predominant. From E8 to E9, cells belonging to the marginal stream cross the midline laterally in both directions. Beyond E12, longitudinal migrations occur ventrally in both rostrocaudal and caudorostral directions. The immunohistochemical analyses carried out on chimeras generated in experiment V revealed the existence of fibers in marginal zones prior to the onset of the migration of cell bodies. These observations support the suggestion that such tangential fibers serve as guidance substrates for the subpial migrations of cells in the medulla oblongata.     

人脐带间充质干细胞分泌白细胞介素6促进骨肉瘤细胞增殖和迁移

 目的: 探讨人脐带间充质干细胞(hUC-MSCs)对骨肉瘤Saos-2细胞增殖和迁移的作用及分子机制。方法: 组织块贴壁法分离培养hUC-MSCs,流式细胞术鉴定细胞表面标记物;CCK-8法和细胞计数法检测hUC-MSCs条件培养基(CM)、重组人白细胞介素6(rhIL-6)及IL-6中和抗体对Saos-2细胞增殖的作用;ELISA检测hUC-MSCs分泌IL-6的量;RT-PCR检测增殖相关基因增殖细胞核抗原(PCNA)、cyclin D1和survivin的转录水平;Transwell实验检测hUC-MSCs和Saos-2细胞迁移能力的变化。结果: hUC-MSCs可向Saos-2细胞迁移;hUC-MSCs-CM含有高浓度的IL-6,可达(1 835.5±134.1)ng/L;hUC-MSCs-CM和rhIL-6均能促进Saos-2细胞增殖和迁移,IL-6中和抗体能明显削弱hUC-MSCs-CM的促Saos-2细胞增殖和迁移作用;RT-PCR显示hUC-MSCs-CM和rhIL-6均能上调Saos-2细胞增殖相关基因PCNA、cyclin D1和survivin的表达,而IL-6中和抗体则削弱了这一作用。结论: 脐带间充质干细胞能向骨肉瘤Saos-2细胞迁移,并通过分泌IL-6促进其增殖和迁移。     

棕榈酸刺激的巨噬细胞对HepG2细胞侵袭和迁移的影响

目的:研究棕榈酸刺激的巨噬细胞对肝癌细胞侵袭和迁移能力的影响,并进一步探讨其作用机制。方法:应用棕榈酸(0.16 mmol/L)刺激人急性单核细胞白血病细胞系THP-1来源的巨噬细胞,并取其上清液处理HepG2细胞。细胞迁移实验检测巨噬细胞的迁移能力,侵袭实验和划痕实验分别观察HepG2细胞的纵向迁移能力和横向迁移能力;RT-qPCR检测巨噬细胞和HepG2细胞的炎症/趋化因子及HepG2细胞上皮-间充质转化标志蛋白(E-cadherin和N-cadherin)的mRNA表达水平。结果:棕榈酸促进了巨噬细胞迁移,显著上调巨噬细胞白细胞介素1β(IL-1β)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)和单核细胞趋化蛋白1(MCP-1)的mRNA表达;用棕榈酸刺激巨噬细胞的上清液处理HepG2细胞,其纵向迁移能力和横向迁移力明显强于未经棕榈酸处理组,且HepG2细胞的多种炎症因子和N-cadherin表达上调,E-cadherin表达下调。结论:棕榈酸可以增强巨噬细胞的迁移能力,刺激巨噬细胞产生大量炎症因子/趋化因子,进一步通过旁分泌/内分泌作用于HepG2细胞,促进HepG2细胞的上皮-间充质转化,增强HepG2细胞的侵袭与迁移能力。     

基底硬度对肝细胞与肝癌细胞迁移行为的影响

目的通过比较不同硬度基底对肝细胞和肝癌细胞迁移特征的影响,研究肿瘤细胞迁移行为变化的成因。方法运用免疫荧光染色、形态学分析法和Transwell侵袭实验,观察不同硬度基底上HCCLM3和L02细胞的形态特征及对细胞运动能力进行检测和定量分析。结果 (1)相对于极软(0.5 kPa)和极硬(玻璃)基底,HCCLM3和L02细胞在较软基底(4 kPa)上具有较高的迁移速率和迁移净距离,且L02细胞表现出高的迁移效率。(2)HC-CLM3和L02细胞在不同硬度基底上均方位移趋势一致,较软基底上L02细胞具有较高的方向持续能力。(3)0.5和1 mg/mL三维胶原基质中,HCCLM3细胞穿透基底膜的个数分别显著多于L02细胞穿透基底膜的个数;加入40μg/mL水解酶抑制剂GM6001后,HCCLM3细胞穿透基底膜的个数显著增加,而L02细胞穿透基底膜的个数显著减少。结论 (1)二维较软基底上,L02细胞因有较高的方向持续能力而表现出高的迁移效率。(2)三维胶原基质中,HCCLM3细胞以不同迁移模式适应周围环境,从而表现出更大的侵袭能力。     

膜联蛋白A2对人宫颈癌HeLa细胞增殖、迁移和凋亡的影响

 目的：研究膜联蛋白A2（annexin A2, ANXA2）对人宫颈癌HeLa细胞增殖、迁移和凋亡能力的影响。方法：以HeLa细胞为研究对象,构建过表达载体以及ANXA2-siRNA,转染入细胞。将细胞分为正常对照组、scrambled组、ANXA2过表达组及ANXA2-siRNA组。应用real-time PCR法检测ANXA2 mRNA表达水平及Western blotting检测ANXA2蛋白表达水平。分别采用MTT法、Boyden小室法和流式细胞术观察ANXA2对HeLa细胞增殖、迁移及凋亡能力的影响。结果：ANXA2过表达组可以显著促进HeLa细胞的增殖和迁移;ANXA2-siRNA组明显抑制HeLa细胞的增殖和迁移;ANXA2对HeLa细胞凋亡几乎无影响。结论:沉默ANXA2对人宫颈癌细胞的凋亡无显著影响,但可显著抑制其增殖能力和迁移能力。ANXA2可能在宫颈癌的发生发展中具有十分重要的作用,提示它有可能成为宫颈癌治疗的分子靶点。     

过表达微小RNA-21对c-Kit~+心脏干细胞增殖、迁移及分化的影响

目的:探讨转染微小RNA-21(microRNA-21,miR-21)对c-Kit~+心脏干细胞增殖、分化和迁移的影响。方法:采用酶消化法结合免疫磁珠分选法培养c-Kit~+心脏干细胞,以Lipofectamine~2000为载体将miR-21模拟物(mimics)和其阴性对照(mimics negative control,MNC)分别转染至c-Kit~+心脏干细胞。实验分为正常对照(control)组(正常培养的心脏干细胞)、MNC组(转染MNC 48 h的细胞)和mimics组(转染miR-21 mimics 48 h的细胞)。qPCR检测各组细胞miR-21的表达情况,以CCK-8法和EdU法检测细胞增殖状态,qPCR及免疫荧光检测细胞分化情况,划痕实验观察细胞迁移能力。结果:成功获取c-Kit~+心脏干细胞,经流式细胞术鉴定其高表达c-Kit(90.8%),低表达CD45(0.6%)及CD34(0.5%);与control组相比,mimics组中miR-21表达量显著增高(P0.05),MNC组中miR-21表达量与control组无明显差异。CCK-8和EdU实验结果发现与control组比较,mimics组中细胞增殖能力明显增加(P0.05),MNC组中细胞增殖能力无明显变化;免疫荧光及qPCR结果表明3组心肌细胞谱系标志物Nkx2.5、CD31和α-平滑肌肌动蛋白水平无明显差异;细胞划痕实验结果发现,3组间细胞迁移能力无明显不同。结论:过表达miR-21可显著促进c-Kit~+心脏干细胞的增殖能力,但对细胞迁移及分化能力无明显影响。     

不同基底硬度对人肝癌细胞黏附、铺展和迁移的影响

目的研究不同基底硬度对肝癌细胞黏附、铺展和迁移行为的影响及对细胞骨架装配方式和细胞表面黏附蛋白整合素β1表达的调控,探讨基底的力学特性在肝癌细胞恶性转移过程中的作用。方法通过调节丙聚酰胺和双丙烯酰胺的比率制备不同硬度的聚丙烯酰胺基底,并在基底表面裱衬2.5μg/mL纤维连接蛋白为细胞提供黏附位点;用显微观察并记录不同硬度基底上细胞黏附、铺展和迁移的变化,并用Image J软件定量分析;分别运用免疫荧光和流式细胞仪的方法检测不同基底硬度对肝癌细胞骨架装配和细胞表面整合素β1表达的影响。结果硬基底利于肝癌细胞的黏附和铺展并缩短细胞的铺展时间。过软(1.1 kPa)或过硬(玻璃)的基底都不利于肝癌细胞的迁移,肝癌细胞在中间硬度的基底上(10.7 kPa)迁移速率最高。硬基底促进细胞骨架的装配和整合素β1表达。结论基底硬度通过调节细胞骨架装配和整合素的表达从而影响肝癌细胞的黏附、铺展和迁移。     

Is chemotaxis a factor in the migration of precardiac mesoderm in the chick?

Summary The chick heart is formed from bilateral patches of presumptive cardiac mesoderm cells which migrate over the endoderm and fuse in the midline. We have tested the possibility that this migration is controlled, at least in part, by a chemotactic substance exuded by the anterior end of the endoderm. We have used chick/quail combinations to follow naturally marked cells during the course of their migration. Chimaeric embryos were formed by fusing together parts of chick and quail embryos of stage 5–6. Each embryo possessed two pairs of precardiac regions, the quail pair lying immediately anterior to that of the chick. These chimaeras were then explanted in embryo culture. In the event of chemotaxis, cells from the posterior end of the quail precardiac mesoderm might be expected to invade the chick area. Samples of explants and chimaeras were examined at intervals from 2 to 24 h, but in no case were cells found to have changed their direction of migration as a result of the proximity of anterior endoderm. It is concluded that this work does not provide evidence for a chemotactic attraction by the anterior end of the endoderm. Supported by the following grants: NIH HD 21048, HD 06819, and AHA 880696 (JWL); the British Heart Foundation, and Action Research (R.B.); and an SERC postgraduate studentship (HSE).     

In vitro‐induced Th17 cells fail to induce inflammation in vivo and show an impaired migration into inflamed sites

Recently, IL‐17 produced by Th17 cells was described as pro‐inflammatory cytokine with an eminent role in autoimmune diseases, e.g. rheumatoid arthritis. A lack of IL‐17 leads to amelioration of collagen‐induced arthritis. IL‐17 induction in naïve CD4⁺ T cells depends on IL‐6 and TGF‐β and is enhanced by IL‐23. The in vivo inflammatory potential of in vitro‐primed Th17 cells however, remains unclear. Here, we show that, although IL‐17 neutralisation results in amelioration of murine OVA‐induced arthritis, in vitro‐primed Th17 cells cannot exacerbate arthritic symptoms after adoptive transfer. Furthermore, Th17 cells cannot induce an inflammatory delayed type hypersensitivity reaction because they fail to migrate into inflamed sites, possibly due to the lack of CXCR3 expression. Also, re‐isolated Th17 cells acquired IFN‐γ expression, indicating instability of the Th17 phenotype. Taken together, the data show that IL‐6, TGF‐β and IL‐23 might not provide sufficient signals to induce “fully qualified” Th17 cells.