罗格列酮对ADMA氧化应激损伤内皮生长晕细胞的影响

目的：观察过氧化物体增殖剂激活的受体γ（PPARγ）激动剂罗格列酮对非对称性二甲基精氨酸氧化应激损伤内皮生长晕细胞的影响。方法: 分离脐血中单个核细胞，采用贴壁培养法培养扩增内皮生长晕细胞（EOCs）。以10 μmol/L 非对称性二甲基精氨酸（ADMA）和不同浓度的罗格列酮（0、1、5、10 μmol/L）与第2代细胞孵育72 h，检测细胞的凋亡率、增殖能力、成血管能力，RT-PCR法检测内皮一氧化氮合酶（eNOS）mRNA的表达。结果: 采用贴壁法培养的细胞具有多种内皮细胞特性。ADMA能抑制细胞功能并增加细胞的凋亡率，1、5 μmol/L罗格列酮能够对抗这种损伤（P<0.01）并能够促进细胞的增殖（P<0.01）。但10 μmol/L罗格列酮的保护作用减弱或丧失，甚至可以抑制细胞的成血管能力(P<0.01)。5 μmol/L罗格列酮浓度组eNOS基因表达增强（P<0.01），10 μmol/L组eNOS基因表达减弱（P<0.01）。结论: 低浓度的罗格列酮（<10 μmol/L）能够减轻和保护由ADMA所致的内皮生长晕细胞的氧化应激损伤，并能够促进内皮生长晕细胞增殖，这种作用部分是通过活化eNOS基因实现的。     

ADMA对内皮生长晕细胞凋亡及其相关p38丝裂素活化蛋白激酶表达的影响

目的:探讨非对称性二甲基精氨酸(ADMA)对内皮生长晕细胞(EOCs)凋亡和黏附能力的影响以及凋亡相关p38丝裂素活化蛋白激酶(p38MAPK)表达水平的变化。方法:分离脐血中单个核细胞并原代培养扩增内皮生长晕细胞,免疫细胞化学染色和荧光染色法鉴定其内皮细胞特性。将浓度为0、1、5、10、30μmol/L ADMA与内皮生长晕细胞作用48 h,流式细胞仪检测细胞凋亡率,DAPI染色及AnnexinV/PI双染观察凋亡细胞核形态变化。在倒置显微镜下观察计数重黏附细胞数来测定细胞黏附能力。用特异性的phospho-p38MAPK抗体的W esternb lotting检测p38MAPK的活性。结果:采用贴壁法培养的细胞具有多种内皮细胞特性。ADMA(1-30μmol/L)诱导内皮生长晕细胞的凋亡(P0.01),同时ADMA(5-30μmol/L)使phospho-p38MAPK蛋白表达增加,两者作用均呈浓度依赖性。ADMA作用组和对照组相比,激光共聚焦显微镜下可见更显著的细胞凋亡形态学改变。除1μmol/L ADMA外,5、10、30μmol/L ADMA均可抑制内皮生长晕细胞的黏附能力。结论:ADMA能诱导内皮生长晕细胞发生凋亡并抑制其黏附能力,ADMA诱导内皮生长晕细胞发生凋亡可能与p38 MAPK磷酸化水平上升有关。     

内皮祖细胞在膀胱细胞外基质上的生长及分化

背景：传统的组织工程膀胱支架材料本身无血管结构,植入体内后面临血管化不足的问题。 目的：观察内皮祖细胞与膀胱细胞外基质的生物相容性。 方法：分离培养兔内皮祖细胞,种植于兔膀胱细胞外基质上与其复合培养。将复合生长材料植入兔背部皮下检测其组织相容性。 结果与结论：兔内皮祖细胞能够在膀胱细胞外基质表面正常黏附、生长、增殖,细胞形态良好。内皮祖细胞-膀胱细胞外基质植入兔体内后1周时,可见材料周围炎症反应明显,粘连严重,出血较多;苏木精-伊红染色可见组织中较多炎性细胞浸润,胶原及弹性纤维排列松散。植入后8周时可见材料已降解成碎细丝状,与周围组织融合生长在一起,但质地略脆,易出血;苏木精-伊红染色可见组织中已无明显炎症细胞浸润反应,胶原及弹性纤维排列紧密并且有新生血管长入其中。结果表明内皮祖细胞与膀胱细胞外基质具有良好的相容性,复合培养物与体内组织具有良好的相容性。     

纳米纤维支架的制备及其在组织工程皮肤中的应用

本文通过综述现阶段纳米纤维支架的制备方法、可用材料及制备后的生物功能修饰等方面的研究进展,为设计真正意义的组织工程皮肤纳米纤维支架提供理论帮助。多聚物纳米纤维支架能够提供三维空间结构,并且能够调节细胞行为,具有传递生物分子的潜能,因此它们在组织工程应用中具有广泛的前景。现在能应用多种方法及材料制备纳米纤维结构,但是通过现有的方法和材料还不能将纳米纤维的所有优点完全体现出来,并构建成功一个真正意义上的纳米纤维三维支架结构。所以对纳米纤维支架制备技术的不断改进和对应用的材料体系的深入了解,将对未来临床成功地应用聚合纳米纤维组织工程支架奠定坚实基础。     

新型纳米纤维支架的细胞生物相容性

背景：高孔隙率聚己内酯纳米纤维支架具有适合血管平滑肌细胞黏附、增殖的多级孔径结构,具有良好的细胞生物相容性。 目的：探讨高孔隙率聚己内酯静电纺丝纳米纤维支架的细胞相容性。 方法：根据支架的制作工艺不同分为传统支架组、新型纳米纤维支架组两组,另设单纯细胞组为对照组。采用组织块贴壁法体外原代培养兔主动脉平滑肌细胞并进行传代,用3~6代细胞作为实验用种子细胞。应用WST-1法测定平滑肌细胞黏附率、增殖力,光镜及扫描电镜观察细胞形态,评估支架的细胞生物相容性。 结果与结论：高孔隙率聚己内酯纳米纤维支架对细胞形态无明显影响,新型支架上的种子细胞黏附、增殖及代谢活性情况较传统支架好。提示,高孔隙率聚己内酯静电纺丝纳米纤维支架具有较高的细胞相容性。     

Lir@BSA-PMF纳米颗粒的制备及其细胞功能验证

目的 利用生物膜覆盖纳米粒子的“bottom-up”表面纳米工程化学技术合成牛血清白蛋白(BSA)负载利拉鲁肽(Lir)包裹血小板膜碎片(PMF)的纳米颗粒,并验证其细胞相容性以及抗氧化应激损伤的能力。方法 按照既往文献中的方法提取PMF;利用自组装法制备Lir@BSA纳米颗粒;通过共挤压的方式将PMF包覆在Lir@BSA纳米颗粒表面制备Lir@BSA-PMF。利用粒径、电位、透射电镜、粒径稳定性表征Lir@BSA-PMF颗粒的理化指标;利用酶联免疫吸附试验法计算利拉鲁肽的包封率、负载率和累计释放率;进一步利用SDS-PAGE分析Lir@BSA-PMF仿生纳米载体上是否存在血小板膜完整的膜蛋白质结构;同时利用CCK-8法验证材料的生物相容性;活性氧(ROS)实验探究了Lir@BSA-PMF仿生纳米载体对细胞氧化损伤的影响;最后通过细胞吞噬实验验证细胞对Lir@BSA-PMF仿生纳米载体的摄取效果。结果 制备的Lir@BSA-PMF的纳米粒子粒径可稳定在25 nm,形貌为球形,Zeta电位值为-25.5 mV。利拉鲁肽的包封率、负载率和累计释放率分别为85.56%、7.96%和77.06...     

人脐血中分离培养扩增内皮集落形成细胞及其生物相容性

背景：内皮集落形成细胞是内皮祖细胞的一种亚型,体外培养扩增及其在组织工程中的应用尚不明确。 目的：探索从人脐血中分离培养扩增内皮集落形成细胞并观察其生物相容性。 方法：采用密度梯度离心法从人脐血中分离单个核细胞,接种于Ⅰ型鼠尾胶原包被的培养板上,采用内皮祖细胞专用EGM-2培养基诱导培养,早期传代后扩增,免疫荧光鉴定细胞,并检测其体外成血管和增殖能力,与纳米羟基磷灰石/磷酸三钙材料复合培养后的生物相容性。 结果与结论：脐血来源内皮集落形成细胞呈铺路石样集落生长,吞噬Dil-Ac-LDL并结合FITC-UEA-1,表达CD31,vWF,KDR和Tie-2,早期传代后拥有较强增殖潜能,可在体外大量扩增,在体外基质胶上可形成闭合管腔样结构,复合纳米羟基磷灰石/磷酸三钙材料后生物学特性不受影响。提示可从脐血中分离并体外大量扩增内皮集落形成细胞。     

三种高分子支架对骨髓基质细胞生长影响的研究

研究高分子复合支架聚乳酸均聚物(PLA)、聚乳酸/聚乙二醇共聚物(PLA-PEG)和聚乳酸/聚乙醇酸共聚物(PLGA)对骨髓基质细胞(M SC)黏附、增殖和分化的影响。分离、纯化兔骨髓基质细胞,分别和3种支架材料共培养。在不同时间段,应用细胞计数,碱性磷酸酶(ALP)定量分析,四环素荧光染色,扫描电镜,RT-PCR的方法,观察细胞在3种材料上生长,黏附和矿化沉积情况。结果表明细胞在3种支架材料上生长良好,PLGA上细胞生长的数量最多,其次是PLA-PEG、PLA,呈时间依赖性增加。3种材料上的细胞均表达ALP活性,PLA-PEG和PLGA组的ALP活性无差异,但显著高于PLA组,差异有显著性。RT-PCR反应可检测到骨钙素和纤维I型胶原在mRNA水平的表达。扫描电镜见细胞最初呈球形附着于材料上,7 d后细胞数量增加并分泌细胞外基质。两周后可见钙化结节形成,四环素荧光呈黄绿色染色。结果提示M SC细胞能较好的黏附于3种聚合物支架上,生长良好,并表达一定的成骨潜能,但PLA共聚物PLA-PEG和PLGA优于PLA均聚物,有望成为较好的构建组织工程骨的支架。     

心脏脱细胞支架的制备及其生物相容性

目的:优化心脏脱细胞支架的制备方法,评价所制备的脱细胞支架的基本生物学特征。方法:联合应用十二烷基硫酸钠(SDS)和聚乙二醇辛基苯基醚(Triton X-100)对大鼠心行逆行主动脉灌流制备心脏脱细胞支架。同时,将间充质干细胞(MSCs)接种到支架上构建细胞支架复合体,采用H-E染色及扫描电镜分别对制备支架及复合体进行评价。结果:心脏脱细胞支架大体呈半透明囊状。组织学染色及扫描电镜观察示支架呈多孔网状或束状结构,未见细胞核残留。荧光显微镜观察示MSCs沿支架纤维黏附生长,未见明显坏死细胞。结论:本研究运用灌流法成功制备脱细胞彻底且细胞外基质保留较完整的心脏脱细胞支架,既拥有天然三维结构且具有良好的生物相容性。     

胶原-纳米羟基磷灰石复合支架的细胞相容性

背景：观察成骨细胞在生物材料上的形态、增殖和分化等项目,可评估生物支架材料的生物相容性。 目的：观察复合支架材料纳米羟基磷灰石/胶原对成骨细胞增殖、分化的影响。 方法：取新生24 h内Wistar大鼠的颅盖骨,采用改良胶原酶消化法进行成骨细胞原代培养,取第3代细胞与纳米羟基磷灰石/胶原支架或普通羟基磷灰石材料体外复合培养。培养3,6,9 d后,观察材料周边的细胞形态及支架材料对细胞分化、增殖的影响。 结果与结论：纳米羟基磷灰石/胶原材料较普通的羟基磷灰石材料更有利于成骨细胞的黏附、生长、分化、增殖,证实其生物相容性更好,有望成为一种新型的骨组织工程支架材料。     

Fabrication of Nano-fibrous PLLA Scaffold Reinforced with Chitosan Fibers

In this study, a nano-fibrous PLLA scaffold reinforced by micro-scale chitosan fibers was fabricated using thermally-induced phase separation (TIPS). The morphology, porosity, mechanical performance and pH changes in in vitro degradation of the scaffold were also investigated. Results showed that the mechanical properties of the scaffold increased with the amount of chitosan fibers embedded, and the pH in in vitro degradation of the scaffold changed more slowly than that of the pure nano-fibrous PLLA scaffold without chitosan fibers. The new composite scaffold might be a very promising scaffold for tissue engineering.     

Short Duration Electrical Stimulation to Enhance Neurite Outgrowth and Maturation of Adult Neural Stem Progenitor Cells

New therapies are desperately needed for human central nervous system (CNS) regeneration to circumvent the lack of innate regenerative ability following traumatic injuries. Previously attempted therapies have been stymied by barriers to CNS regeneration largely because of protective mechanisms such as the blood brain barrier, inhibitory molecules, and glial scar formation. The application of electric stimulation (ES) has shown promise for enhancing peripheral nervous system regeneration, but is in its infancy in CNS regeneration. The objective of this study is to better understand how short duration ES can be harnessed to direct adult neural stem progenitor cell (NSPC) neurogenesis, neurite extension, and maturation. Herein, NSPCs were exposed to physiological levels of electrical stimulation of 0.53 or 1.83 V/m (applied power supply setting of 1.2 and 2.5 V) of direct current (DC) for 10 min/days for 2 days with a total differentiation time of 3 days. Culturing conditions consisted of either mitogenic growth factors or the neuronal differentiation factor interferon-γ (IFN-γ). Stimulated NSPCs showed lengths that were over five times longer than unstimulated controls (112.0 ± 88.8 μm at 0.53 V/m vs. 21.3 ± 8.5 μm for 0 V/m with IFN-γ) with the longest neurites reaching up to 600 µm. Additionally, ES resulted in mature neuronal morphologies and signs of differentiation through positive βIII tubulin, neuronal nuclei (NeuN), and better organized filamentous-actin (f-actin) staining with growth cone formation. Additionally, the neurites and soma of stimulated NSPCs showed increases in intracellular Ca²⁺ during stimulation, signifying the presence of functional neurons capable of electrical conductance and communication with other cells. Our study demonstrates that short stimulation times (10 min/ day) result in significant neurite extension of stem cells in a quick time frame (3  days). This ES modality is potentially advantageous for promoting axon re-growth at an injury site using delivered adult stem cells; however, significant work still remains to understand both the delivery approach of cells as well as ES application in vivo.     

Transplanted Late Outgrowth Endothelial Progenitor Cells as Cell Therapy Product for Stroke

Endothelial progenitor cells (EPCs) seem to be a promising option to treat patients with ischemic diseases. Here, we investigated the effects of late outgrowth EPCs, or endothelial colony-forming cells (ECFCs), a recently defined homogeneous subtype of EPCs, in a rat model of transient middle cerebral artery occlusion (MCAO). Either vehicle or 4.10⁶ ECFCs, isolated from human cord blood, were intravenously injected 24?h after 1?h MCAO in rats assigned to control and transplanted groups respectively. ¹¹¹In-oxine-labeled ECFCs specifically homed to ischemic hemisphere and CM-Dil prelabeled ECFCs preferentially settled in the inner boundary of the core area of transplanted animals. Although incorporation of cells into neovessels was hardly detectable, ECFCs transplantation was associated with a reduction in apoptotic cell number, an increase in capillary density and a stimulation of neurogenesis at the site of injury. These effects were associated with an increase in growth factors expression in homogenates from ischemic area and may be related to the secretion by ECFCs of soluble factors that could affect apoptosis, vascular growth and neurogenesis. Microscopic examination of the ischemic hemisphere showed that ECFCs transplantation was also associated with a reduction in reactive astrogliosis. In conclusion, we demonstrated that ECFCs injected 24?h after MCAO settled in the injured area and improved functional recovery. The neurological benefits may be linked to a reduction in ischemia-induced apoptosis and a stimulation of ischemia-induced angiogenesis and neurogenesis. These findings raise perspectives for the use of ECFCs as a well-characterized cell therapy product for optimal therapeutic outcome after stroke.     

电纺丝方法制备卵磷脂改性聚乳酸血管组织工程支架材料

目的为了改善聚乳酸材料的生物相容性和韧性,在PLLA中混合卵磷脂材料进行电纺丝,以制备血管组织工程支架材料。方法使用共混方法制备聚乳酸／卵磷脂材料,利用红外拉曼光谱仪观察其共混性能,使用电纺丝的方法制各血管组织工程支架,并采用滴液法测定接触角和液体渗透法测定孔隙率,最后使用万能试验机考察卵磷脂浓度对共混材料拉伸性能的影响。结果加入卵磷脂对电纺丝纤维的表面形貌没有明显的影响。两种材料经过物理混合后,材料保持了卵磷脂的生物活性。随着卵磷脂含量的增加,共混材料的接触角逐渐降低,由纯PLLA无纺布的75．2°。降至10％浓度卵磷脂的32．5°,证明材料的亲水性逐渐增加。而电纺丝支架的孔隙率为74．4％到81．8％,适合应用于生物医学、组织工程等领域。最后,随着共混材料中卵磷脂浓度的增加,拉伸强度逐渐降低,而断裂伸长率有所增加。结论卵磷脂可以增加聚乳酸材料的亲水性和整体力学强度,使之更加适用于血管组织工程领域。     

Growth Characteristics of Retinal Capillary Endothelial Cells Compared with Pulmonary Vein Endothelial Cells in Culture

Bovine retinal capillary endothelial cells (RCECs) and pulmonary vein endothelial cells (PVECs) were isolated and investigated in plate culture, three-dimensional culture and in co-culture with pericytes. In plate culture, RCECs required growth factor in the medium for growth whereas PVECs did not. Phenotypic modulation (a tendency to become similar morphologically to smooth muscle cells, and to accumulate into thread-like structures) was observed in PVECs but not in RCECs. In three-dimensional culture, RCECs contracted, aggregated and were unable to proliferate. Proliferation was elicited when the gel matrix was adsorbed by fibronectin or upon co-culture with pericytes. In contrast, PVECs not only proliferated but also formed tubular structures. In co-culture with pericytes, PVECs in close contact with, or in near apposition to pericytes formed tubular structures earlier than those without contact in the same dish. These results provide new findings about differences in the growth characteristics of endothelial cells between microvessels and large vessels. In addition, it is considered that pericytes may promote tube formation by endothelial cells in three-dimensional culture. Acta Pathol Jpn 41: 133-142, 1991.     

Endothelial Cells in Co-culture Enhance Embryonic Stem Cell Differentiation to Pancreatic Progenitors and Insulin-Producing Cells through BMP Signaling

Endothelial cells (ECs) represent the major component of the embryonic pancreatic niche and play a key role in the differentiation of insulin-producing β cells in vivo. However, it is unknown if ECs promote such differentiation in vitro. We investigated whether interaction of ECs with mouse embryoid bodies (EBs) in culture promotes differentiation of pancreatic progenitors and insulin-producing cells and the mechanisms involved. We developed a co-culture system of mouse EBs and human microvascular ECs (HMECs). An increase in the expression of the pancreatic markers PDX-1, Ngn3, Nkx6.1, proinsulin, GLUT-2, and Ptf1a was observed at the interface between EBs and ECs (EB-EC). No expression of these markers was found at the periphery of EBs cultured without ECs or those co-cultured with mouse embryonic fibroblasts (MEFs). At EB-EC interface, proinsulin and Nkx6.1 positive cells co-expressed phospho-Smad1/5/8 (pSmad1/5/8). Therefore, EBs were treated with HMEC conditioned media (HMEC-CM) suspecting soluble factors involved in bone morphogenetic protein (BMP) pathway activation. Upregulation of PDX-1, Ngn3, Nkx6.1, insulin-1, insulin-2, amylin, SUR1, GKS, and amylase as well as down-regulation of SST were detected in treated EBs. In addition, higher expression of BMP-2/-4 and their receptor (BMPR1A) were also found in these EBs. Recombinant human BMP-2 (rhBMP-2) mimicked the effects of the HMEC-CM on EBs. Noggin (NOG), a BMP antagonist, partially inhibited these effects. These results indicate that the differentiation of EBs to pancreatic progenitors and insulin-producing cells can be enhanced by ECs in vitro and that BMP pathway activation is central to this process.     

脂质体介导的VEGF_(165)基因转染对内皮细胞生长的作用

构建血管内皮细胞生长因子基因VEGF165真核表达载体pcDNA3 VEGF165,以阳离子脂质体介导的基因转染技术 ,将基因转入原代培养的人脐静脉内皮细胞中。结果表明 ,基因转染 1h后细胞内就有VEGFDNA存在 ,VEGFmRNA水平显著上升 ;基因转染 2d后培养液上清VEGF蛋白表达显著上升 (135 5 12± 6 2 34)pg/ml和 (19 2 7± 2 96 )pg/ml,P <0 0 1。转染VEGF165基因 2d的内皮细胞再经程序降温冷冻保存复苏后 ,其存活率显著高于对照组 (pcDNA3 组 ) (90 13%± 2 84 %和81 5 2 %± 2 15 % ,P <0 0 5 ) ,凋亡率显著低于对照组 (7 15 %± 0 4 2 %和 17 6 1%± 1 5 6 % ,P <0 0 5 )。MTT法显示转染VEGF165基因能促进内皮细胞VEGF蛋白的表达 ,促进细胞增殖 ,抑制细胞凋亡。在治疗心脏及下肢动脉缺血性疾病中 ,VEGF165基因治疗可能具有重要的意义。     

生物可降解载药纤维的成形特性的研究

为了开发一种用于治疗肿瘤的局部定位缓释给药系统，本研究在室温条件制备了生物可降解的聚乳酸（PLLA）纤维，并且详细研究了制备过程中的处方工艺条件（聚合物分子量、聚合物浓度、注射速度、出口口径以及固化液的种类）对聚乳酸纤维的成形特性（纤维直径、纤维的表面与内部结构以及纤维的结晶度）的影响。此外，还在聚乳酸纤维上上载了一种脂溶性模型药物（尼莫地平），并对载药纤维的体外释放性质进行了研究。结果表明，这类载药纤维可以成为一种有开发前景的局部定位给药缓释系统。     

Endothelial Cells Synthesize Basic Fibroblast Growth Factor and Transforming Growth Factor Beta

Abstract

Endothelial cells, including human umbilical vein endothelial cells (HUVEC), bovine aortic endothelial cells (BAEC), and bovine capillary endothelial cells (BCEC) in culture synthesize basic fibroblast growth factor (bFGF) and transforming growth factor type beta (TGF-beta). Basic FGF was cell-associated and synthesis was demonstrated by (i) the presence of bFGF mRNA species, (ii) binding to heparin-Sepharose and elution at 1.5 M NaCI, (iii) cross-reactivity with anti-bFGF antibodies when analyzed by electrophoretic blotting, and (iv) biological activity. Basic FGF was found in cell lysates at 2.3 ng/30⁶ cells in HUVEC, 2.0 ng/10⁶ cells in BCEC, and 13 ng/10⁶ cells in BAEC. TGF-beta was secreted into media, and synthesis was demonstrated by (i) presence of TGF-beta mRNA species, (ii) cross-reactivity with anti-TGF-beta antibodies when analyzed by immunoprecipitation, (iii) competitive binding with authentic human platelet-derived TGF-beta that was blocked by TGF-beta specific blocking antibodies, and (iv) inhibition of [³H]TdR incorporation in CCI-64 cells. TGF-beta was secreted in an inactive form and required acid activation for detection. HUVEC synthesized 2.0 ng TGF-beta/10⁶ cells per 12 hr; BCEC, 3.5 ng; and BAEC, 3.5 ng. HUVEC proliferation was not affected by treatment with exogenous TGF-beta, while BCEC proliferation was decreased by treatment with TGF-beta. Vascular endothelium is thus a source for these two potent multifunctional regulatory molecules, both of which may affect the growth of endothelium and neighboring fibroblasts, smooth muscle cells and white blood cells. The activation or release of these factors by endothelium may be a precipitating event in important cellular processes such as wound healing, organogenesis, and angiogenesis.     

电纺丝PLLA/HA复合纤维支架的制备及体外降解性能研究

随着组织工程和支架材料的技术发展，复合支架材料的制备成为当前研究的热点。本研究通过静电纺丝法制备了左旋聚乳酸／羟基磷灰石（PLLA／HA）复合纳米纤维膜，对纤维膜的结构形态进行分析，并研究其在与人体环境相近的磷酸盐缓冲溶液（pH7．4，37℃）中浸泡不同时间的体外降解过程。结果表明：HA纳米粒子与PLLA基体间存在化学键合，纳米粒子使纤维直径增大且表面粗糙程度增加，HA的引入抑制了PLLA降解过程中的自催化作用，减缓了PLLA的降解速度，复合纤维体系降解液的pH值在降解后期呈缓慢上升趋势。