Small molecule inhibitor DDQ-treated hippocampal neuronal cells show improved neurite outgrowth and synaptic branching

The process of neurite outgrowth and branching is a crucial aspect of neuronal development and regeneration.Axons and dendrites,sometimes referred to as neurites,are extensions of a neuron's cellular body that are used to start networks.Here we explored the effects of diethyl(3,4-dihydroxyphenethylamino)(quinolin-4-yl)methylphosphonate(DDQ)on neurite developmental features in HT22 neuronal cells.In this work,we examined the protective effects of DDQ on neuronal processes and synaptic outgrowth in differentiated HT22cells expressing mutant Tau(mTau)cDNA.To investigate DDQ chara cteristics,cell viability,biochemical,molecular,western blotting,and immunocytochemistry were used.Neurite outgrowth is evaluated through the segmentation and measurement of neural processes.These neural processes can be seen and measured with a fluorescence microscope by manually tracing and measuring the length of the neurite growth.These neuronal processes can be observed and quantified with a fluorescent microscope by manually tracing and measuring the length of the neuronal HT22.DDQ-treated mTau-HT22 cells(HT22 cells transfected with cDNA mutant Tau)were seen to display increased levels of synaptophysin,MAP-2,andβ-tubulin.Additionally,we confirmed and noted reduced levels of both total and p-Tau,as well as elevated levels of microtubule-associated protein 2,β-tubulin,synaptophysin,vesicular acetylcholine transporter,and the mitochondrial biogenesis protein-pe roxisome prolife rator-activated receptor-gamma coactivator-1α.In mTa u-expressed HT22 neurons,we observed DDQ enhanced the neurite characteristics and improved neurite development through increased synaptic outgrowth.Our findings conclude that mTa u-HT22(Alzheimer's disease)cells treated with DDQ have functional neurite developmental chara cteristics.The key finding is that,in mTa u-HT22 cells,DDQ preserves neuronal structure and may even enhance nerve development function with mTa u inhibition.

Modulation of the Nogo signaling pathway to overcome amyloid-β-mediated neurite inhibition in human pluripotent stem cell-derived neurites

Neuronal cell death and the loss of connectivity are two of the primary pathological mechanisms underlying Alzheimer's disease.The accumulation of amyloid-βpeptides,a key hallmark of Alzheimer's disease,is believed to induce neuritic abnormalities,including reduced growth,extension,and abnormal growth cone morphology,all of which contribute to decreased connectivity.However,the precise cellular and molecular mechanisms governing this response remain unknown.In this study,we used an innovative approach to demonstrate the effect of amyloid-βon neurite dynamics in both two-dimensional and three-dimensional cultu re systems,in order to provide more physiologically relevant culture geometry.We utilized various methodologies,including the addition of exogenous amyloid-βpeptides to the culture medium,growth substrate coating,and the utilization of human-induced pluripotent stem cell technology,to investigate the effect of endogenous amyloid-βsecretion on neurite outgrowth,thus paving the way for potential future applications in personalized medicine.Additionally,we also explore the involvement of the Nogo signaling cascade in amyloid-β-induced neurite inhibition.We demonstrate that inhibition of downstream ROCK and RhoA components of the Nogo signaling pathway,achieved through modulation with Y-27632(a ROCK inhibitor)and Ibuprofen(a Rho A inhibitor),respectively,can restore and even enhance neuronal connectivity in the presence of amyloid-β.In summary,this study not only presents a novel culture approach that offers insights into the biological process of neurite growth and inhibition,but also proposes a specific mechanism for reduced neural connectivity in the presence of amyloid-βpeptides,along with potential intervention points to restore neurite growth.Thereby,we aim to establish a culture system that has the potential to serve as an assay for measuring preclinical,predictive outcomes of drugs and their ability to promote neurite outgrowth,both generally and in a patient-specific manner.

Outgrowth endothelial cells form a functional cerebral barrier and restore its integrity after damage

Breakdown of blood-brain barrier,formed mainly by brain microvascular endothelial cells(BMECs),represents the major cause of mortality during early phases of ischemic strokes.Hence,discovery of novel agents that can effectively replace dead or dying endothelial cells to restore blood-brain barrier integrity is of paramount importance in stroke medicine.Although endothelial progenitor cells(EPCs)represent one such agents,their rarity in peripheral blood severely limits their adequate isolation and therapeutic use for acute ischemic stroke which necessitate their ex vivo expansion and generate early EPCs and outgrowth endothelial cells(OECs)as a result.Functional analyses of these cells,in the present study,demonstrated that only OECs endocytosed DiI-labelled acetylated low-density lipoprotein and formed tubules on matrigel,prominent endothelial cell and angiogenesis markers,respectively.Further analyses by flow cytometry demonstrated that OECs expressed specific markers for sternness(CD34),immaturity(CD133)and endothelial cells(CD31)but not for hematopoietic cells(CD45).Like BMECs,OECs established an equally tight in vitro model of human BBB with astrocytes and pericytes,suggesting their capacity to form tight junctions.Ischemic injury mimicked by concurrent deprivation of oxygen and glucose(4 hours)or deprivation of oxygen and glucose followed by reperfusion(20 hours)affected both barrier integrity and function in a similar fashion as evidenced by decreases in transendothelial electrical resistance and increases in paracellular flux,respectively.Wound scratch assays comparing the vasculoreparative capacity of cells revealed that,compared to BMECs,OECs possessed a greater proliferative and directional migratory capacity.In a triple culture model of BBB established with astrocytes,pericytes and BMEC,exogenous addition of OECs effectively repaired the damage induced on endothelial layer in serum-free conditions.Taken together,these data demonstrate that OECs may effectively home to the site of vascular injury and repair the damage to maintain(neuro)vascular homeostasis during or after a cerebral ischemic injury.

JAK/STAT signaling regulates tissue outgrowth and male germline stem cell fate in Drosophila

In multicellular organisms, biological activities are regulated by cell signaling. The various signal transduction path- ways regulate cell fate, proliferation, migration, and polarity. Miscoordination of the communicative signals will lead to disasters like cancer and other fatal diseases. The JAK/STAT signal transduction pathway is one of the pathways, which was first identified in vertebrates and is highly conserved throughout evolution. Studying the JAK/STAT signal transduc- tion pathway in Drosophila provides an excellent opportunity to understand the molecular mechanism of the cell regu- lation during development and tumor formation. In this review, we discuss the general overview of JAK/STAT signaling in Drosophila with respect to its functions in the eye development and stem cell fate determination.

ROCK inhibition enhances neurite outgrowth in neural stem cells by upregulating YAP expression in vitro

Spontaneous axonal regeneration of neurons does not occur after spinal cord injury because of inhibition by myelin and other inhibitory factors. Studies have demonstrated that blocking the Rho/Rho-kinase （ROCK） pathway can promote neurite outgrowth in spinal cord injury models. In the present study, we investigated neurite outgrowth and neuronal differentiation in neural stem cells from the mouse subventricular zone after inhibition of ROCK in vitro. Inhibition of ROCK with Y-27632 increased neurite length, enhanced neuronal differentiation, and upregulated the expression of two major signaling pathway effectors, phospho-Akt and phospho-mitogen-activated protein kinase, and the Hippo pathway effector YAP. These results suggest that inhibition of ROCK mediates neurite outgrowth in neural stem cells by activating the Hippo signaling pathway.

Inhibition of neurite outgrowth using commercial myelin associated glycoprotein-Fc in neuro-2a cells

Myelin-associated glycoprotein（MAG） inhibits the growth of neurites from nerve cells. Extraction and purification of MAG require complex operations; therefore, we attempted to determine whether commercially available MAG-Fc can replace endogenous MAG for research purposes. Immunofluorescence using specific antibodies against MAG, Nogo receptor（NgR） and paired immunoglobulin-like receptor B（PirB） was used to determine whether MAG-Fc can be endocytosed by neuro-2a cells. In addition, neurite outgrowth of neuro-2a cells treated with different doses of MAG-Fc was evaluated. Enzyme linked immunosorbent assays were used to measure RhoA activity. Western blot assays were conducted to assess Rho-associated protein kinase（ROCK） phosphorylation. Neuro-2a cells expressed NgR and PirB, and MAG-Fc could be endocytosed by binding to NgR and PirB. This activated intracellular signaling pathways to increase RhoA activity and ROCK phosphorylation, ultimately inhibiting neurite outgrowth. These findings not only verify that MAG-Fc can inhibit the growth of neural neurites by activating RhoA signaling pathways, similarly to endogenous MAG, but also clearly demonstrate that commercial MAG-Fc is suitable for experimental studies of neurite outgrowth.

Enhancing Effect of Aged Garlic Extract on Induction of Morphological Differentiation with Neurite Outgrowth in NGF-treated PC12 Cells

Background: We have been searching effective compounds that can stimulate the growth and differentiation of nerve cells. We found previously that fulleren derivatives enhanced induction of morphological differentiation with neurite outgrowth in nerve growth factor (NGF)-treated PC12 cells. In the course of our further search for other effective compounds, we found the aged garlic extract (AGE) has the activity similar to fulleren. Methods: PC12 cells were used to examine the effectiveness of test compound. Results: AGE enhanced the stimulating effect of NGF to induce morphological differentiation with neurite outgrowth in PC12 cells. In order to examine the active constituents of AGE, it was fractionated into several components. The activity was mainly localized in the F1 fraction that contains low molecular weight polar compounds. S-Allymercaptocysteine (SAMC) is one of the sulfur components of AGE present in F1 fraction and found to exhibit the enhancing effect similar to AGE. Conclusion: AGE had the ability to induce morphological differentiation with neurite outgrowth in NGF-treated PC12 cell and SAMC was one of its active constituents.

Peritoneal macrophages attenuate retinal ganglion cell survival and neurite outgrowth

Inflammation is a critical pathophysiological process that modulates neuronal survival in the central nervous system after disease or injury.However,the effects and mechanisms of macrophage activation on neuronal survival remain unclear.In the present study,we co-cultured adult Fischer rat retinas with primary peritoneal macrophages or zymosan-treated peritoneal macrophages for 7 days.Immunofluorescence analysis revealed that peritoneal macrophages reduced retinal ganglion cell survival and neurite outgrowth in the retinal explant compared with the control group.The addition of zymosan to peritoneal macrophages attenuated the survival and neurite outgrowth of retinal ganglion cells.Conditioned media from peritoneal macrophages also reduced retinal ganglion cell survival and neurite outgrowth.This result suggests that secretions from peritoneal macrophages mediate the inhibitory effects of these macrophages.In addition,increased inflammationand oxidation-related gene expression may be related to the enhanced retinal ganglion cell degeneration caused by zymosan activation.In summary,this study revealed that primary rat peritoneal macrophages attenuated retinal ganglion cell survival and neurite outgrowth,and that macrophage activation further aggravated retinal ganglion cell degeneration.This study was approved by the Animal Ethics Committee of the Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong,Shantou,Guangdong Province,China,on March 11,2014(approval no.EC20140311(2)-P01).

Role of miR-124 in the regulation of retinoic acid-induced Neuro-2A cell differentiation

Retinoic acid can cause many types of cells,including mouse neuroblastoma Neuro-2 A cells,to differentiate into neurons.However,it is still unknown whether microRNAs(miRNAs)play a role in this neuronal differentiation.To address this issue,real-time polymerase chain reaction assays were used to detect the expression of several differentiation-related miRNAs during the differentiation of retinoic acid-treated Neuro-2 A cells.The results revealed that miR-124 and miR-9 were upregulated,while miR-125 b was downregulated in retinoic acid-treated Neuro-2 A cells.To identify the miRNA that may play a key role,miR-124 expression was regulated by transfection of miRNA mimics or inhibitors.Morphological analysis results showed that inhibition of miR-124 expression reversed the effects of retinoic acid on neurite outgrowth.Moreover,miR-124 overexpression alone caused Neuro-2 A cells to differentiate into neurons,and its inhibitor could block this effect.These results suggest that miR-124 plays an important role in retinoic acid-induced differentiation of Neuro-2 A cells.

Molecular mechanism of panaxydol on promoting axonal growth in PC12 cells

Nerve growth factor（NGF） promotes axonal growth in PC12 cells primarily by regulating the RTK-RAS-MEK-ERK pathway. Panaxydol, a polyacetylene isolated from Panax notoginseng, can mimic the effects of NGF. Panaxydol promotes neurite outgrowth in PC12 cells, but its molecular mechanism remains unclear. Indeed, although alkynol compounds such as panaxydol can increase intracellular cyclic adenosine 3′,5′-monophosphate（cAMP） levels and the ERK inhibitor U0126 inhibits alkynol-induced axonal growth, how pathways downstream of cAMP activate ERK have not been investigated. This study observed the molecular mechanism of panaxydol-, NGF-and forskolin-induced PC12 cell axon growth using specific signaling pathway inhibitors. The results demonstrated that although the RTK inhibitor SU5416 obviously inhibited the growth-promoting effect of NGF, it could not inhibit the promoting effect of panaxydol on axonal growth of PC12 cells. The adenylate cyclase inhibitor SQ22536 and cAMP-dependent protein kinase inhibitor RpcAMPS could suppress the promoting effect of forskolin and panaxydol on axonal growth. The ERK inhibitor U0126 inhibited axonal growth induced by all three factors. However, the PKA inhibitor H89 inhibited the promoting effect of forskolin on axonal growth but could not suppress the promoting effect of panaxydol. A western blot assay was used to determine the effects of stimulating factors and inhibitors on ERK phosphorylation levels. The results revealed that NGF activates the ERK pathway through tyrosine receptors to induce axonal growth of PC12 cells. In contrast, panaxydol and forskolin increased cellular cAMP levels and were inhibited by adenylyl cyclase inhibitors. The protein kinase A inhibitor H89 completely inhibited forskolin-induced axonal outgrowth and ERK phosphorylation, but could not inhibit panaxydol-induced axonal growth and ERK phosphorylation. These results indicated that panaxydol promoted axonal growth of PC12 cells through different pathways downstream of cAMP. Considering that exchange protein directly activated by cAMP 1（Epac1） plays an important role in mediating cAMP signaling pathways, RNA interference experiments targeting the Epac1 gene were employed. The results verified that Epac1 could mediate the axonal growth signaling pathway induced by panaxydol. These findings suggest that compared with NGF and forskolin, panaxydol elicits axonal growth through the cAMP-Epac1-Rap1-MEK-ERK-CREB pathway, which is independent of PKA.

Enteric glia mediate neuronal outgrowth through release of neurotrophic factors

Previous studies have shown that transplanted enteric glia enhance axonal regeneration, reduce tissue damage, and promote functional recovery following spinal cord injury. However, the mechanisms by which enteric glia mediate these beneficial effects are unknown. Neurotrophic factors can promote neuronal differentiation, survival and neurite extension. We hypothesized that enteric glia may exert their protective effects against spinal cord injury partially through the secretion of neurotrophic factors. In the present study, we demonstrated that primary enteric glia cells release nerve growth factor, brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor over time with their concentrations reaching approximately 250, 100 and 50 pg/mL of culture medium respectively after 48 hours. The biological relevance of this secretion was assessed by incubating dissociated dorsal root ganglion neuronal cultures in enteric glia-conditioned medium with and/or without neutralizing antibodies to each of these proteins and evaluating the differences in neurite growth. We discovered that conditioned medium enhances neurite outgrowth in dorsal root ganglion neurons. Even though there was no detectable amount of neurotrophin-3 secretion using ELISA analysis, the neurite outgrowth effect can be attenuated by the antibody-mediated neutralization of each of the aforementioned neurotrophic factors. Therefore, enteric glia secrete nerve growth factor, brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor and neurotrophin-3 into their surrounding environment in concentrations that can cause a biological effect.

Matrilin-2, an extracellular adaptor protein, is needed for the regeneration of muscle, nerve and other tissues

The extracellular matrix （ECM） performs essential functions in the differentiation, maintenance and remodeling of tissues during development and regeneration, and it undergoes dynamic changes during remodeling concomitant to alterations in the cell-ECM interactions. Here we discuss recent data addressing the critical role of the widely expressed ECM protein, matrilin-2 （Matn2） in the timely onset of differentiation and regeneration processes in myogenic, neural and other tissues and in tumorigenesis. As a multiadhesion adaptor protein, it interacts with other ECM proteins and integrins. Matn2 promotes neurite outgrowth, Schwann cell migration, neuromuscular junction formation, skeletal muscle and liver regeneration and skin wound healing. Matn2 deposition by myoblasts is crucial for the timely induction of the global switch toward terminal myogenic differentiation during muscle regeneration by affecting transforming growth factor beta/bone morphogenetic protein 7/Smad and other signal transduction pathways. Depending on the type of tissue and the pathomechanism, Math2 can also promote or suppress tumor growth.

Dental pulp stem cells stimulate neuronal differentiation of PC12 cells

Dental pulp stem cells(DPSCs) secrete neurotrophic factors which may play an important therapeutic role in neural development, maintenance and repair. To test this hypothesis, DPSCs-conditioned medium(DPSCs-CM) was collected from 72 hours serum-free DPSCs cultures. The impact of DPSCs-derived factors on PC12 survival, growth, migration and differentiation was investigated. PC12 cells were treated with nerve growth factor(NGF), DPSCs-CM or co-cultured with DPSCs using Transwell inserts for 8 days. The number of surviving cells with neurite outgrowths and the length of neurites were measured by image analysis. Immunocytochemical staining was used to evaluate the expression of neuronal markers NeuN, microtubule associated protein 2(MAP-2) and cytoskeletal marker βIII-tubulin. Gene expression levels of axonal growth-associated protein 43 and synaptic protein Synapsin-I, NeuN, MAP-2 and βIII-tubulin were analysed by quantitative polymerase chain reaction(qRT-PCR). DPSCs-CM was analysed for the neurotrophic factors(NGF, brain-derived neurotrophic factor [BDNF], neurotrophin-3, and glial cell-derived neurotrophic factor [GDNF]) by specific ELISAs. Specific neutralizing antibodies against the detected neurotrophic factors were used to study their exact role on PC12 neuronal survival and neurite outgrowth extension. DPSCs-CM significantly promoted cell survival and induced the neurite outgrowth confirmed by NeuN, MAP-2 and βIII-tubulin immunostaining. Furthermore, DPSCsCM was significantly more effective in stimulating PC12 neurite outgrowths than live DPSCs/PC12 co-cultures over the time studied. The morphology of induced PC12 cells in DPSCs-CM was similar to NGF positive controls;however, DPSCs-CM stimulation of cell survival was significantly higher than what was seen in NGF-treated cultures. The number of surviving PC12 cells treated with DPSCs-CM was markedly reduced by the addition of anti-GDNF, whilst PC12 neurite outgrowth was significantly attenuated by anti-NGF, anti-GDNF and anti-BDNF antibodies. These findings demonstrated that DPSCs were able to promote PC12 survival and differentiation. DPSCs-derived NGF, BDNF and GDNF were involved in the stimulatory action on neurite outgrowth, whereas GDNF also had a significant role in promoting PC12 survival. DPSCs-derived factors may be harnessed as a cell-free therapy for peripheral nerve repair. All experiments were conducted on dead animals that were not sacrificed for the purpose of the study. All the methods were carried out in accordance with Birmingham University guidelines and regulations and the ethical approval is not needed.

全氟辛烷磺酸对人骨髓间充质干细胞成神经分化的损伤作用

流行病学结果显示全氟辛烷磺酸(perfluorooctane sulfonate,PFOS)暴露与儿童认知能力降低相关,动物毒理学研究表明围产期PFOS暴露造成子代认知能力下降等神经损伤。但是发育中神经系统对PFOS暴露响应更敏感的毒理学机制尚不清楚。本研究基于人骨髓间充质干细胞(human bone marrow derived mesenchymal stem cells,hBMSCs)体外神经分化模型,评估环境相关浓度PFOS暴露对不同分化阶段细胞的毒性效应。在无显著细胞毒性浓度下,分化过程中暴露于20~500 nmol·L^(-1)PFOS对神经元突触产生抑制效应并呈剂量依赖性,抑制率为24.2%~43.9%。细胞经诱导成神经分化后暴露于PFOS,仅在500 nmol·L^(-1)暴露组产生了显著抑制效应,抑制率为17.7%。通过免疫荧光染色检测神经元标志物微管相关蛋白2(microtubule-associated protein 2,MAP2),分化过程中100 nmol·L^(-1)和500 nmol·L^(-1)的PFOS暴露显著抑制了MAP2的表达,抑制率分别为15.9%和18.6%,但分化后PFOS暴露未对MAP2表达产生显著影响。通过对Ca 2+进行实时成像及图像捕捉,发现PFOS暴露刺激成神经分化的细胞钙瞬变,500 nmol·L^(-1)的PFOS暴露诱导钙瞬变峰值F/F 0升高至对照组的1.25倍,提示细胞成神经分化及神经元信号转导等受到干扰。研究结果发现成神经分化过程中细胞对PFOS暴露更为敏感,从细胞分化层面提示了PFOS发育神经毒性的潜在毒理机制,须进一步研究PFOS对细胞分化和细胞命运的敏感靶标,为该类新污染物的健康风险评价和管控提供依据。

不同营养因子组合对大鼠脊髓神经元的作用研究

[目的]探讨NGF、bFGF和BDNF的不同组合对大鼠脊髓神经元的作用。[方法]利用神经元培养技术,将新生1 d的SD大鼠脊髓神经元接种于培养板,根据不同因子两两组合分为3个实验组、空白对照组和单因子对照组,因子终浓度均为50 ng/ml。倒置相差显微镜动态观察,接种后第3、7 d细胞爬片行β-tubulin3免疫荧光染色和Hoechst染色。测量阳性细胞最长突起长度,计算阳性细胞率,第1、3、5、7、9 d行MTT检查,以OD值绘制生长曲线。[结果]各实验组神经元突起长度均优于对照组(P<0.05),联合应用组优于单因子组,其中以A组(BDNF+bFGF)突起最长,各实验组β-tubulin3阳性细胞率均高于对照组,MTT结果与染色结果一致。[结论]特定浓度下NGF、bFGF及BDNF可以有效促进大鼠脊髓神经元轴突的生长,并可有效维持神经元细胞存活,联合应用作用增强,BDNF+bFGF作用最强。

阿魏酸对bFGF诱导PC12细胞分化的影响

目的:探讨阿魏酸在低浓度碱性成纤维生长因子(bFGF)诱导大鼠肾上腺髓质嗜铬瘤细胞(PC12细胞)分化的作用及其初步机制。方法:在0 ng/mL或1 ng/mL bFGF条件下培养PC12细胞,以PC12细胞的突起长度及诱导率确定药效。结果:阿魏酸在无bFGF的情况下不能诱导PC12分化,但在低浓度bFGF(1 ng/mL)情况下,与bFGF(1 ng/mL)对照组比较可明显诱导PC12细胞分化(P<0.01),这种作用能被有丝分裂原激活的蛋白激酶(MAPK)特异性抑制剂PD98059所抑制。结论:阿魏酸可增强bFGF诱导PC12细胞分化,其机制可能与MAPK信号通路有关。

小鼠胚胎与子宫单层上皮细胞共培养的研究

本文报道建立了小鼠胚胎与小鼠子宫单层上皮细胞体外共培养系统。结果揭示；小鼠胚胎与 子宫单层上皮细胞共培养可以促进胚胎的发育、粘附和扩展；如果培养液中加入 ３、６７ × １０－６ｍｏｌ／Ｌ １７β－雌二醇，可以显著提高胚胎在共培养系统中的发育率、粘附率和扩展率。以上结果表明：小鼠 胚胎与小鼠子宫单层上皮细胞共培养系统是研究胚泡着床机理较理想的研究手段。

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(P<0.01),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。

人外周血来源的过度生长内皮细胞的分离、培养及鉴定

与内皮干细胞相比,外周血来源的过度生长内皮细胞(blood outgrowth endothelial cells,BOECs)富含血管新生和细胞黏附所需的蛋白,生物学特性更像内皮细胞;同时它克服了成熟的人脐血内皮细胞体外培养扩增量少和表型易发生改变的缺点,成为一种研究血管异常相关性疾病的新工具。本研究旨在建立从人外周血中体外培养、扩增BOECs,并进行鉴定的方法。采集外周血,梯度离心获得单个核细胞,接种于胶原铺板的细胞培养皿上,EGM-2培养4周。观察BOECs的形态学特征,流式细胞术分析细胞表面抗原表达。血管性血友病因子(von Willebrand factor,v WF)多聚体分析BOECs上清v WF多聚体分布,荧光共聚焦显微镜鉴定细胞内v WF的贮存及v WF的刺激分泌。结果表明,体外诱导培养4周左右,出现克隆性生长的细胞集落,BOECs呈现"铺路石"样外观。经过3周左右的扩增后,过度生长的内皮细胞表达CD31、CD34、EPCR阳性,CD14、CD45、CD133阴性。收集BOECs上清,进行v WF多聚体分析,与正常血浆相比v WF多聚体分布无差异。在荧光共聚焦显微镜下观察,BOECs内贮存v WF,加入佛波酯(phorbol-12-myristate-13-acetate,PMA)刺激后,细胞内v WF增加,细胞表面可见v WF丝状结构。结论:本研究运用该实验方法在国内首次实现了人BOECs的体外培养、扩增及鉴定。该方法可以为血管性血友病病人发病机制的探讨提供天然的细胞模型,并可能为病人基因治疗提供新工具。

非对称性二甲基精氨酸通过Caspase-3信号转导通路诱导晚期内皮祖细胞凋亡

目的观察非对称性二甲基精氨酸对晚期内皮祖细胞的诱导凋亡作用,通过检测Caspase-3的活性探讨其诱导凋亡的信号转导通路。方法从脐带血中分离培养晚期内皮祖细胞。DiI-ac-LDL和FITC-UEA-Ⅰ双荧光染色法鉴定其内皮属性;不同浓度非对称性二甲基精氨酸(0、1、5、10和30μmol/L)作用于细胞48h,激光共聚焦显微镜观察细胞形态变化,流式细胞仪测定细胞凋亡率;不同浓度非对称性二甲基精氨酸作用于细胞48h或10μmol/L非对称性二甲基精氨酸作用于细胞不同时间(0、3、6和9h),酶标仪测Caspase-3活性;加入Caspase-3特异性抑制剂(ac-DEVD-CHO)半小时后加入10μmol/L非对称性二甲基精氨酸作用48h,流式细胞仪测细胞凋亡率。结果非对称性二甲基精氨酸作用于晚期内皮祖细胞后,可见典型的细胞凋亡形态学改变,且随非对称性二甲基精氨酸浓度增加细胞凋亡增加。在此过程中,Caspase-3被活化,其活化程度随非对称性二甲基精氨酸浓度增加及作用时间延长而升高。加入Caspase-3特异性抑制剂后细胞凋亡减少。结论非对称性二甲基精氨酸可呈浓度依赖性诱导晚期内皮祖细胞凋亡,此作用可能是通过激活内源性凋亡途径Caspase-3信号转导通路实现的。