ELAVL1 promotes LPS-induced endothelial cells injury through modulation of cytokine storm

Sepsis is a life-threatening systemic organ dysfunction caused by the host's unregulated response to a widespread bacterial infection. Endothelial injury is a major pathophysiologic symptom of sepsis and is considered a critical factor in promoting the progression of disease severity. ELAV like RNA binding protein 1(ELAVL1) is a ubiquitously expressed RNA-binding protein that may play an important role during sepsis. Nonetheless, the molecular mechanisms of ELAVL1 on endothelial cell damage in sepsis have not been well defined. Here, we aimed to confirm the role of ELAVL1 in sepsis-induced endothelial cell damage using lipopolysaccharide (LPS)-induced zebrafish and endothelial cells (ECs) models. We found that zebrafish larvae treated with LPS exhibited systemic endothelial cell damage, mostly manifested as pericardial edema, curved tail, and impaired angiogenesis. LPS treatments also significantly induced the expression levels of inflammatory cytokines (interleukin-6 (IL-6), IL-8, and tumor necrosis factor (TNF)-α) in vivo. In vitro, we observed the increase of ELAVL1 cytoplasmic translocation with LPS treatment. Mechanistically, targeted disruption of the ELAVL1 gene decreased the expression of TNF-α, IL-6, and IL-8 during induction of sepsis and alleviated LPS-induced blood vessel injury in zebrafish. Taken together, our study indicates that ELAVL1 knockdown may alleviate sepsis-induced endothelial cells injury by suppressing cytokine storm. Our research suggests that inhibition of ELAVL1 could reduce the level of inflammatory cytokine production induced by LPS and protect against endothelial cell injury. ELAVL1 might be a potential therapeutic target to block endothelial cells injury associated with sepsis.     

Snail and the microRNA-200 family act in opposition to regulate epithelial-to-mesenchymal transition and germ layer fate restriction in differentiating ESCs

The reprogramming of somatic cells to inducible pluripotent stem cells requires a mesenchymal-to-epithelial transition. While differentiating ESCs can undergo the reverse process or epithelial-to-mesenchymal transition (EMT), little is known about the role of EMT in ESC differentiation and fate commitment. Here, we show that Snail homolog 1 (Snail) is expressed during ESC differentiation and is capable of inducing EMT on day 2 of ESC differentiation. Induction of EMT by Snail promotes mesoderm commitment while repressing markers of the primitive ectoderm and epiblast. Snail's impact on differentiation can be partly explained through its regulation of a number of ESC-associated microRNAs, including the microRNA-200 (miR-200) family. The miR-200 family is normally expressed in ESCs but is downregulated in a Wnt-dependent manner during EMT. Maintenance of miR-200 expression stalls differentiating ESCs at the epiblast-like stem cell (EpiSC) stage. Consistent with a role for activin in maintaining the EpiSC state, we find that inhibition of activin signaling decreases miR-200 expression and allows EMT to proceed with a bias toward neuroectoderm commitment. Furthermore, miR-200 requires activin to efficiently maintain cells at the epiblast stage. Together, these findings demonstrate that Snail and miR-200 act in opposition to regulate EMT and exit from the EpiSC stage toward induction of germ layer fates. By modulating expression levels of Snail, activin, and miR-200, we are able to control the order in which cells undergo EMT and transition out of the EpiSC state.     

Jagged1过表达促进老龄大鼠来源的内皮祖细胞向成熟内皮细胞分化

 目的：探讨上调Jagged1表达对内皮培养条件下老龄大鼠来源的内皮祖细胞（EPC）向内皮细胞分化的影响。方法：脱臼处死1～2月龄和19～26月龄SD大鼠,PBS冲洗股骨和胫骨骨髓,Ficoll密度梯度离心分离单个核细胞, 应用含10% FBS的DMEM/F12培养基以差速贴壁法进行体外培养,DiI-ac-LDL与FITC-UEA-1荧光双染进行EPC特性鉴定。实验分为4组：对照组、PIRES2-EGFP转染组、PIRES2-EGFP-Jagged1转染组和未转染的年轻大鼠来源EPC组。荧光显微镜下计数GFP阳性细胞数并计算转染效率;免疫荧光、RT-PCR和Western blotting检测Jagged1 mRNA和蛋白、von Willebrand因子（vWF）及血管内皮生长因子激酶插入区受体（KDR）mRNA表达,体外血管生成实验检测EPC的血管形成能力。结果：转染后Jagged1在EGFP-Jagged1组表达较对照组显著增强（P<0.01）;Jagged1过表达显著促进老龄大鼠EPC vWF与KDR mRNA表达（P<0.01）和体外血管生成能力（P<0.01）; vWF与KDR mRNA表达以及体外血管生成能力在Jagged1转染组与年轻大鼠EPC组间未见有显著差别。结论：Jagged1过表达促进内皮培养条件下老龄大鼠来源EPC向成熟内皮细胞分化。     

转化生长因子β1促进骨髓间充质干细胞迁移与上调Snail表达有关

背景：转化生长因子β1可促进骨髓间充质干细胞迁移及增殖,但机制尚不清楚。 目的：观察转化生长因子β1对体外培养的骨髓间充质干细胞侵袭力的影响,以及对Snail、基质金属蛋白酶2表达的调节作用。 方法：采用密度梯度离心结合贴壁法分离、培养大鼠骨髓间充质干细胞。用改良的Transwell小室检测0,0.5,1,2,5,10 μg/L的转化生长因子β1对细胞迁移的影响。用脂质体转染针对Snail基因的特异性小分子干扰RNA至骨髓间充质干细胞,观察转染前后Snail和基质金属蛋白酶2 的表达。 结果与结论：外源性转化生长因子β1对骨髓间充质干细胞迁移的促进作用具有剂量依赖性,在2 μg/L时达到最高。在此浓度下,Snail、基质金属蛋白酶2 mRNA表达明显增高。Snail基因沉默可以明显抑制转化生长因子β1对基质金属蛋白酶2表达的促进作用。提示转化生长因子β1可通过促进骨髓间充质干细胞基质金属蛋白酶2的表达提高其迁移能力,此作用与上调Snail表达有关。     

抑制HMGB1表达促进血管瘤内皮细胞凋亡的机制研究

目的:探讨高迁移率族蛋白B1(HMGB1)对血管瘤内皮细胞(HemECs)活力和凋亡的影响及机制。方法:分离培养人HemECs,将设计并合成的HMGB1小干扰RNA(HMGB1-siRNA)转染HemECs。CCK-8法检测各组细胞活力;流式细胞术检测细胞凋亡率及活性氧(ROS)含量;Western blot检测HMGB1、NF-κB p65、p-IκBα、细胞周期蛋白D1(cyclin D1)和survivin的蛋白表达。结果:与空白对照组比较,转染HMGB1-siRNA的HemECs中HMGB1的蛋白表达显著降低(P0.05)。与NC组比较,转染HMGB1-siRNA的HemECs活力显著降低,凋亡率显著升高,ROS含量显著升高,NF-κB p65、p-IκBα、cyclin D1和survivin的蛋白表达均显著降低(P0.05);且与si-HMGB1组比较,HemECs中加入NF-κB信号通路抑制剂PDTC后,细胞活力抑制、凋亡率和ROS诱导及NF-κB p65、p-IκBα、cyclin D1和survivin的蛋白表达下调更明显(P0.05)。结论:抑制HMGB1表达可降低人HemECs活力和诱导凋亡,机制可能是通过提高ROS含量及下调NF-κB信号通路。     

microRNA-21可调控Flk1+间充质干细胞的迁移

目的 用microRNA-21抑制刺转染Flk1+间充质干细胞(MSC),探讨microRNA-21对Flk1+MSC(MSC)迁移的影响.方法 在脂质体介导下用microRNA-21抑制剂瞬时转染Flk1+MSC,用Transweil技术检测细胞迁移,用Real-time PCR技术检测micro-RNA的表达.结果 与对照组相比,实验组中microRNA-21表达明显下调,实验组细胞在12、16和20 h迁移率分别是对照组的77.5%、71.3%和69.8%.结论 microRNA-21可调控Flk1+MSC的迁移.     

CCR5介导6T-CEM细胞穿过人脑微血管内皮细胞单层能力分析

目的 为进一步研究T细胞在阿尔茨海默病(AD)患者脑内发挥的作用,探讨CCR5在6T-CEM穿过人脑微血管内皮细胞(HBMECs)过程中所发挥的生物学功能.方法 应用免疫荧光和Western blot等技术,集中探讨了HBMECs膜受体CCR5在6T-CEM细胞穿过HBMECs过程中作用.结果 在6T-CEM细胞与HBMECs单层单独孵育过程中,引起HBMECs膜受体CCR5表达变化;HBMECs膜受体CCR5的高表达使6T-CEM细胞穿过HBMECs单层能力增强.结论 HBMECs膜受体CCR5参与了6T-CEM细胞穿过HBMECs单层过程.     

同型半胱氨酸促进内皮细胞表达巨噬细胞炎性蛋白1α

单核细胞迁入动脉内皮下问隙是动脉粥样硬化(AS)发生的早期事件。巨噬细胞炎性蛋白1α(MIP-1α)对单核细胞有趋化作用。高同型半胱氨酸血症是AS的一个独立危险因子。我们观察同型半胱氨酸(HCY)是否诱导培养的人脐静脉内皮细胞(HUVEC)表达MIP-1α,探讨HCY在AS形成中的作用。     

Cartilage oligometric matrix protein-angiopoietin-1 promotes revascularization through increased survivin expression in dermal endothelial cells of skin grafts in mice

The present study examined the effects of cartilage oligometric matrix protein angiopoietin-1 (COMP-Ang1) on the revascularization of mice skin grafts. Full-thickness skin grafts were autotransferred into BALB/c mice. The donor grafts were soaked in COMP-Ang1 protein (50 mug/ml, n = 10) or in bovine serum albumin (BSA) (50 mug/ml, n = 10) dissolved in 1 ml of sterile, phosphate-buffered saline for 5 minutes before transfer. Revascularization of the grafts was monitored using an intravital microscope on postoperative days 3, 4, and 5. Morphological and immunohistochemical analyses were performed to evaluate platelet-endothelial cell adhesion molecule-1 and survivin expression and apoptotic signal in the transplanted grafts. Grafts soaked in COMP-Ang1 (COMP-Ang1 group) showed significantly increased revascularization compared with grafts soaked in BSA (BSA group) on intravital microscopy and platelet-endothelial cell adhesion molecule-1 staining. The COMP-Ang1 group showed a significant increase of survivin expression in the endothelial cells and a reduction of apoptotic signal in comparison to the BSA group. Therefore, we believe that COMP-Ang1 provides the therapeutic benefit of enhancing the survival of vascular endothelial cells during transplantation of skin graft.     

葛根素通过ERK1/2信号通路促进内皮细胞增殖

目的:体外观察葛根素对人脐静脉内皮细胞(HUVEC)的促增殖作用,并对其机制进行初步探讨。方法:采用四甲基偶氮唑蓝(MTT)法检测不同浓度葛根素对HUVEC细胞增殖的影响;流式细胞术检测细胞凋亡;Western blot检测p-ERK1/2蛋白表达水平。结果:葛根素能剂量依赖性促进HUVEC增殖,在80μM效果最明显,且作用36h时,能显著减少早期凋亡,激活ERK1/2磷酸化。结论:葛根素素对人脐静脉内皮细胞有明显的促进增殖作用,其作用可能与ERK1/2的活化有关。     

尼古丁促人脐静脉内皮细胞凋亡

目的研究不同浓度尼古丁对人脐静脉内皮细胞的促凋亡作用及作用机制。方法体外培养人脐静脉内皮细胞,根据尼古丁浓度分组为10-6、10-7和10-8mol/L组及对照组。尼古丁作用24 h后,用CCK-8法检测细胞增殖,Annexin V-FITC荧光双染色法检测细胞凋亡。Western blot检测Bax、Bcl-2和PARP-1蛋白表达,对其作用机制进行研究。结果与对照组相比,10-6、10-7mol/L尼古丁组细胞增殖活性下降(P0.05);凋亡数目增多(P0.01)。促凋亡蛋白Bax的表达量增加(P0.01);抑凋亡蛋白Bcl-2表达明显减少(P0.01);PARP-1表达增加(P0.01)。结论一定浓度的尼古丁对血管内皮细胞具有促凋亡作用,加速动脉粥样硬化性疾病的发生发展。     

Long noncoding RNA PVT1 promotes cervical cancer progression through epigenetically silencing miR‐200b

Long noncoding RNA PVT1 has been reported to be dysregulated and play vital roles in a variety of cancers. However, the functions and molecular mechanisms of PVT1 in cervical cancer remain unclear. The objective of this study was to investigate the expression, clinical significance, biological roles, and underlying functional mechanisms of PVT1 in cervical cancer. Our results revealed that PVT1 is upregulated in cervical cancer tissues. Enhanced expression of PVT1 is associated with larger tumor size, advanced International Federation of Gynecology and Obstetrics stage, and poor prognosis of cervical cancer patients. Using gain‐of‐function and loss‐of‐function approaches, we demonstrated that overexpression of PVT1 promotes cervical cancer cells proliferation, cell cycle progression and migration, and depletion of PVT1 inhibits cervical cancer cell proliferation, cell cycle progression, and migration. Mechanistically, we verified that PVT1 binds to EZH2, recruits EZH2 to the miR‐200b promoter, increases histone H3K27 trimethylation level on the miR‐200b promoter, and inhibits miR‐200b expression. Furthermore, the effects of PVT1 on cervical cell proliferation and migration depend upon silencing of miR‐200b. Taken together, our findings confirmed that PVT1 functions as an oncogene in cervical cancer and indicated that PVT1 is not only an important prognostic marker, but also a potential therapy target for cervical cancer.     

MiR-199a-5p promotes migration and tube formation of human cytomegalovirus-infected endothelial cells through downregulation of SIRT1 and eNOS

Human cytomegalovirus (HCMV) infection has been shown to contribute to vascular disease through the induction of angiogenesis. However, the role of microRNA in angiogenesis induced by HCMV infection remains unclear. The present study was thus designed to explore the potential effect of miR-199a-5p on angiogenesis and to investigate the underlying mechanism in endothelial cells. We found that HCMV infection of endothelial cells (ECs) enhanced expression of miR-199a-5p and reduced the SIRT1 protein level at 24 h postinfection (hpi). Transfection with miR-199a-5p mimics significantly suppressed SIRT1 protein expression and promoted cellular migration and tube formation induced by HCMV infection, which could be reversed by transfection with an miR-199a-5p inhibitor. Furthermore, pretreatment with resveratrol depressed motility and tube formation of HCMV-infected ECs, which could be reversed by SIRT1 siRNA. Finally, overexpression of miR-199a-5p decreased the level of eNOS modulated by SIRT1, an effect repressed by transfection with an miR-199a-5p inhibitor. In summary, HCMV infection of endothelial cells upregulates miR-199a-5p expression and enhances cell migration and tube formation through downregulation of SIRT1/eNOS by miR-199a-5p.     

长链非编码RNA OIP5-AS1对miR-143介导的动脉粥样硬化血管内皮细胞的作用

目的 探讨长链非编码RNA OIP5-AS1对miR-143介导的动脉粥样硬化血管内皮细胞的作用.方法 首先收集2016年1月至2018年12月我院心内科收治的动脉粥样硬化患者50例,同期收集我院体检中心身体健康志愿者50例作为对照组,采用qPCR检测和比较外周血循环OIP5-AS1的表达水平差异.以人脐动脉内皮细胞(...     

Silent information regulator 1 (SIRT1) promotes the migration and proliferation of endothelial progenitor cells through the PI3K/Akt/eNOS signaling pathway

Silent information regulator 1 (SIRT1) mediates many effects of caloric restriction (CR) on an organism’s lifespan and metabolic pathways. Recent reports have also emphasized its role in vascular function. The present study was designed to investigate the effects of SIRT1 on the properties of mouse spleen derived endothelial progenitor cells (EPCs). SIRT1 in EPCs was significantly increased by serum and by vascular endothelial growth factor (VEGF). Moreover, an adenovirus (Ad) vector expressing SIRT1 (Ad-SIRT1)-mediated overexpression of SIRT1 directly enhanced migration and proliferation of EPCs, whereas silencing of endogenous SIRT1 in EPCs inhibited cell functions. In addition, LY294002 (a PI3K inhibitor), sc-221226 (an Akt inhibitor), and L-NAME (an NOS inhibitor) abolished Ad-SIRT1-induced migration and proliferation of EPCs, and prevented nitric oxide (NO) production. Phosphorylation of Akt, PI3K, and endothelial nitricoxide synthase (eNOS) were up-regulated by Ad-SIRT1, which was attenuated by LY294002, sc-221226, and L-NAME. Together, the results suggested that through the PI3K/Akt/eNOS signaling pathway, SIRT1 plays an important role in the biological properties of EPCs.     

吡格列酮促进大鼠骨髓内皮祖细胞的增殖

背景：内皮祖细胞具有增殖、迁移和分化为内皮细胞的特征,对冠状动脉硬化性心脏病及糖尿病心血管并发症的发生、发展可能起着重要作用。 目的：探讨选择性过氧化物酶体增殖物激活受体γ激动剂吡格列酮对大鼠骨髓内皮祖细胞增殖的影响及相关机制。 方法：①采用密度梯度离心法和差速贴壁法培养大鼠骨髓内皮祖细胞,置于含0,1,10,50,100,200 μmol/L吡格列酮的培养基中培养,观察吡格列酮促进内皮祖细胞增殖的最佳浓度。②将培养7 d的内皮祖细胞随机分5组：对照组加含二甲基亚砜的培养液;吡格列酮组加入50 μmol/L吡格列酮;PPAR-γ拮抗剂组加入50 μmol/L吡格列酮及10 μmol/L过氧化物酶体增殖物激活受体γ拮抗剂GW9662;PI3K/Akt阻滞剂组加入50 μmol/L吡格列酮及50 μmol/L磷脂酰肌醇3-激酶/蛋白激酶B通道阻滞剂Wortmannin;ERK阻滞剂组加入50 μmol/L吡格列酮及20 μmol/L细胞外调节蛋白激酶通道阻滞剂PD98059,观察不同组内皮祖细胞的增殖情况。 结果与结论：倒置显微镜下见培养前4 d细胞增殖不明显,第5-10天迅速增殖,并可见细胞集落及线状结构形成,第10天可达80%融合。培养第7天的内皮祖细胞具有吞噬Dil标记的乙酰化低密度脂蛋白和FITC标记的荆豆凝集素1的功能。10-200 μmol/L的吡格列酮均可明显促进内皮祖细胞的增殖(P < 0.01),以50 μmol/L吡格列酮的作用最明显。进一步阻断相关信号通路发现,Wortmannin和GW9662可明显拮抗吡格列酮的促细胞增殖作用,而PD98059对吡格列酮的作用无影响。说明吡格列酮促进大鼠骨髓内皮祖细胞增殖的作用是通过磷脂酰肌醇3-激酶/蛋白激酶B信号通路介导的。