Neural stem cell-derived exosomes regulate cell proliferation,migration,and cell death of brain microvascular endothelial cells via the miR-9/Hes1 axis under hypoxia

Background:Our previous study found that mouse embryonic neural stem cell(NSC)-derived exosomes(EXOs)regulated NSC differentiation via the miR-9/Hes1 axis.However,the effects of EXOs on brain microvascular endothelial cell(BMEC)dysfunction via the miR-9/Hes1 axis remain unknown.Therefore,the current study aimed to determine the effects of EXOs on BMEC proliferation,migration,and death via the miR-9/Hes1 axis.Methods:Immunofluorescence,quantitative real-time polymerase chain reaction,cell counting kit-8 assay,wound healing assay,calcein-acetoxymethyl/propidium iodide staining,and hematoxylin and eosin staining were used to determine the role and mechanism of EXOs on BMECs.Results:EXOs promoted BMEC proliferation and migration and reduced cell death under hypoxic conditions.The overexpression of miR-9 promoted BMEC prolifera-tion and migration and reduced cell death under hypoxic conditions.Moreover,miR-9 downregulation inhibited BMEC proliferation and migration and also promoted cell death.Hes1 silencing ameliorated the effect of amtagomiR-9 on BMEC proliferation and migration and cell death.Hyperemic structures were observed in the regions of the hippocampus and cortex in hypoxia-induced mice.Meanwhile,EXO treatment improved cerebrovascular alterations.Conclusion:NSC-derived EXOs can promote BMEC proliferation and migra-tion and reduce cell death via the miR-9/Hes1 axis under hypoxic conditions.Therefore,EXO therapeutic strategies could be considered for hypoxia-induced vascular injury.

Exosomes derived from microglia overexpressing miR-124-3p alleviate neuronal endoplasmic reticulum stress damage after repetitive mild traumatic brain injury

We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repetitive mild traumatic brain injury remains unclear.In this study,we first used an HT22 scratch injury model to mimic traumatic brain injury,then co-cultured the HT22 cells with BV2 microglia expressing high levels of miR-124-3p.We found that exosomes containing high levels of miR-124-3p attenuated apoptosis and endoplasmic reticulum stress.Furthermore,luciferase reporter assay analysis confirmed that miR-124-3p bound specifically to the endoplasmic reticulum stress-related protein IRE1α,while an IRE1αfunctional salvage experiment confirmed that miR-124-3p targeted IRE1αand reduced its expression,thereby inhibiting endoplasmic reticulum stress in injured neurons.Finally,we delivered microglia-derived exosomes containing miR-124-3p intranasally to a mouse model of repetitive mild traumatic brain injury and found that endoplasmic reticulum stress and apoptosis levels in hippocampal neurons were significantly reduced.These findings suggest that,after repetitive mild traumatic brain injury,miR-124-3 can be transferred from microglia-derived exosomes to injured neurons,where it exerts a neuroprotective effect by inhibiting endoplasmic reticulum stress.Therefore,microglia-derived exosomes containing miR-124-3p may represent a novel therapeutic strategy for repetitive mild traumatic brain injury.

Engineered targeting tLyp-1 exosomes as gene therapy vectors for efficient delivery of siRNA into lung cancer cells

Natural exosomes can express specific proteins and carbohydratemolecules on the surface and hence have demonstrated the great potentials for gene therapy of cancer.However,the use of natural exosomes is restricted by their low transfection efficiency.Here,we report a novel targeting tLyp-1 exosome by gene recombinant engineering for delivery of siRNA to cancer and cancer stem cells.To reach such a purpose,the engineered tLyp-1-lamp2b plasmids were constructed and amplified in Escherichia coli.The tLyp-1-lamp2b plasmids were further used to transfect HEK293T tool cells and the targeting tLyp-1 exosomes were isolated from secretion of the transfected HEK293T cells.Afterwards,the artificially synthesized siRNA was encapsulated into targeting tLyp-1 exosomes by electroporation technology.Finally,the targeting siRNA tLyp-1 exosomes were used to transfect cancer or cancer stem cells.Results showed that the engineered targeting tLyp-1 exosomes had a nanosized structure(approximately 100 nm)and high transfection efficiency into lung cancer and cancer stem cells.The function verifications demonstrated that the targeting siRNA tLyp-1 exosomes were able to knock-down the target gene of cancer cells and to reduce the stemness of cancer stem cells.In conclusion,the targeting tLyp-1 exosomes are successfully engineered,and can be used for gene therapy with a high transfection efficiency.Therefore,the engineered targeting tLyp-1 exosomes offer a promising gene delivery platform for future cancer therapy.

Neural stem cell-derived exosomes promote mitochondrial biogenesis and restore abnormal protein distribution in a mouse model of Alzheimer's disease

Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheimer’s disease affects the entire brain,further research is needed to elucidate alterations in mitochondrial metabolism in the brain as a whole.Here,we investigated the expression of several important mitochondrial biogenesis-related cytokines in multiple brain regions after treatment with neural stem cell-derived exosomes and used a combination of whole brain clearing,immunostaining,and lightsheet imaging to clarify their spatial distribution.Additionally,to clarify whether the sirtuin 1(SIRT1)-related pathway plays a regulatory role in neural stem cell-de rived exosomes interfering with mitochondrial functional changes,we generated a novel nervous system-SIRT1 conditional knoc kout AP P/PS1mouse model.Our findings demonstrate that neural stem cell-de rived exosomes significantly increase SIRT1 levels,enhance the production of mitochondrial biogenesis-related fa ctors,and inhibit astrocyte activation,but do not suppress amyloid-βproduction.Thus,neural stem cell-derived exosomes may be a useful therapeutic strategy for Alzheimer’s disease that activates the SIRT1-PGC1αsignaling pathway and increases NRF1 and COXIV synthesis to improve mitochondrial biogenesis.In addition,we showed that the spatial distribution of mitochondrial biogenesis-related factors is disrupted in Alzheimer’s disease,and that neural stem cell-derived exosome treatment can reverse this effect,indicating that neural stem cell-derived exosomes promote mitochondrial biogenesis.

Exosomes from circ-Astn1-modified adipose-derived mesenchymal stem cells enhance wound healing through miR-138-5p/SIRT1/FOXO1 axis regulation

BACKGROUND Wound healing impairment is a dysfunction induced by hyperglycemia and its effect on endothelial precursor cells(EPCs)in type 2 diabetes mellitus.There is increasing evidence showing that exosomes(Exos)derived from adipose-derived mesenchymal stem cells(ADSCs)exhibit the potential to improve endothelial cell function along with wound healing.However,the potential therapeutic mechanism by which ADSC Exos contribute to wound healing in diabetic mice remains unclear.AIM To reveal the potential therapeutic mechanism of ADSC Exos in wound healing in diabetic mice.METHODS Exos from ADSCs and fibroblasts were used for high-throughput RNA sequencing(RNA-Seq).ADSC-Exo-mediated healing of full-thickness skin wounds in a diabetic mouse model was investigated.We employed EPCs to investigate the therapeutic function of Exos in cell damage and dysfunction caused by high glucose(HG).We utilized a luciferase reporter(LR)assay to analyze interactions among circular RNA astrotactin 1(circ-Astn1),sirtuin(SIRT)and miR-138-5p.A diabetic mouse model was used to verify the therapeutic effect of circ-Astn1 on Exo-mediated wound healing.RESULTS High-throughput RNA-Seq analysis showed that circ-Astn1 expression was increased in ADSC Exos compared with Exos from fibroblasts.Exos containing high concentrations of circ-Astn1 had enhanced therapeutic effects in restoring EPC function under HG conditions by promoting SIRT1 expression.Circ-Astn1 expression enhanced SIRT1 expression through miR-138-5p adsorption,which was validated by the LR assay along with bioinformatics analyses.Exos containing high concentrations of circ-Astn1 had better therapeutic effects on wound healing in vivo compared to wild-type ADSC Exos.Immunofluorescence and immunohistochemical investigations suggested that circ-Astn1 enhanced angiopoiesis through Exo treatment of wounded skin as well as by suppressing apoptosis through promotion of SIRT1 and decreased forkhead box O1 expression.CONCLUSION Circ-Astn1 promotes the therapeutic effect of ADSC-Exos and thus improves wound healing in diabetes via miR-138-5p absorption and SIRT1 upregulation.Based on our data,we advocate targeting the circ-Astn1/miR-138-5p/SIRT1 axis as a potential therapeutic option for the treatment of diabetic ulcers.

Low-temperature 3D-printed collagen/chitosan scaffolds loaded with exosomes derived from neural stem cells pretreated with insulin growth factor-1 enhance neural regeneration after traumatic brain injury

There are various clinical treatments for traumatic brain injury,including surgery,drug therapy,and rehabilitation therapy;howeve r,the therapeutic effects are limited.Scaffolds combined with exosomes represent a promising but challenging method for improving the repair of traumatic brain injury.In this study,we determined the ability of a novel 3D-printed collagen/chitosan scaffold loaded with exosomes derived from neural stem cells pretreated with insulin-like growth factor-1(3D-CC-INEXOS) to improve traumatic brain injury repair and functional recove ry after traumatic brain injury in rats.Composite scaffolds comprising collagen,chitosan,and exosomes derived from neural stem cells pretreated with insulin-like growth fa ctor-1(INEXOS) continuously released exosomes for 2weeks.Transplantation of 3D-CC-INExos scaffolds significantly improved motor and cognitive functions in a rat traumatic brain injury model,as assessed by the Morris water maze test and modified neurological seve rity scores.In addition,immunofluorescence staining and transmission electron microscopy showed that3D-CC-INExos implantation significantly improved the recove ry of damaged nerve tissue in the injured area.In conclusion,this study suggests that transplanted3D-CC-INExos scaffolds might provide a potential strategy for the treatment of traumatic brain injury and lay a solid foundation for clinical translation.

EGCG-exosomes通过miR-30a/Beclin-1轴抑制自噬减轻心肌缺血/再灌注损伤

目的:探讨表没食子儿茶素没食子酸酯(EGCG)预处理心肌细胞分泌的外泌体(exosomes)对心肌缺血/再灌注(I/R)损伤的作用及分子机制。方法:体外培养H9c2心肌细胞,给予或不给予EGCG预处理,建立缺氧/复氧模型。提取、纯化外泌体,采用在体基因干扰或基因敲除技术,构建antagomiR-30a和Beclin-1^(+/-)小鼠,建立I/R模型,缺血30 min心肌注射外泌体,研究EGCG预处理心肌细胞分泌的exosomes(EGCG-exosomes)对I/R的作用。采用双荧光素酶报告基因实验检测miR-30a与Beclin-1的相互作用,TTC染色法检测心肌梗死面积,苏木精—伊红(HE)染色观察心肌细胞形态变化;酶联免疫吸附试验(ELISA)法检测血清心肌肌钙蛋I(cTnI)含量;透射电子显微镜观察自噬小体数量;实时荧光定量聚合酶链式反应(RT-qPCR)、蛋白印迹法(western blotting法)检测miR-30a与自噬相关基因和蛋白的表达。结果:与I/R组相比,exosomes组自噬体数量减少,心肌损伤减轻。与exosomes组相比,EGCG-exosomes组心肌梗死面积缩小,cTnI含量降低,自噬体数量减少,Beclin-1和LC3-Ⅱ基因及蛋白表达下调,cathepsin D蛋白表达下调,p62基因及蛋白表达上调;沉默miR-30a促进心肌I/R自噬发生,给予EGCGexosomes则逆转上述作用;此外,敲低Beclin-1与EGCG-exosomes有协同抑制自噬作用(均P<0.05)。结论:EGCG-exosomes通过miR-30a/Beclin-1轴抑制自噬,减轻心肌I/R损伤。

circRNA SIPA1L1修饰牙髓干细胞来源外泌体促血管生成能力的机制

目的 探究环状RNA(circRNA)信号诱导增殖相关蛋白1样蛋白1(SIPA1L1)修饰的人牙髓干细胞(hDPSC)来源外泌体(Exo)对人脐静脉内皮细胞(HUVEC)血管生成能力的影响及机制。方法 从牙髓组织分离培养hDPSC,将circSIPA1L1过表达质粒载体转染至hDPSC后,分离Exo并进行鉴定。将HUVEC分为对照组、hDPSC Exo组、circSIPA1L1-hDPSC Exo组,培养48 h后,Matrigel基质胶血管形成实验检测血管形成能力,qRT-PCR和Western blot测定血管内皮细胞生长因子(VEGF)、血管内皮细胞生长因子受体2(VEGFR2)、胎盘生长因子(PGF)的表达水平。结果 从未转染的hDPSC与转染circSIPA1L1的hDPSC中成功分离出Exo,且相较于h DPSC来源的Exo,转染circSIPA1L1的hDPSC来源的Exo中circSIPA1L1相对表达量显著上调(P <0.05)。与hDPSC Exo组比较,circSIPA1L1-hDPSC Exo组HUVEC的管样结构形成数目显著增加(P <0.05),VEGF、VEGFR2、PGF mRNA与蛋白相对表达量也显著上调(P<0.05)。结论 circRNA SIPA1L1修饰hDPSC来源的Exo能够促进血管生成,其机制可能与上调VEGF、VEGFR2、PGF的表达水平有关。

Sirt1对高糖诱导的足细胞外泌体释放的影响

目的探讨烟酰胺腺嘌呤二核苷酸依赖的去乙酰化酶1(Sirt1)对高糖诱导的足细胞外泌体释放的影响。方法将永生化小鼠足细胞MPC5分为正常糖组(5.5 mmol/L葡萄糖,A组)、高渗组(5.5 mmol/L葡萄糖+24.5 mmol/L甘露醇,B组)、高糖组(30.0 mmol/L葡萄糖,C组)、高糖+Sirt1过表达慢病毒转染组(Sirt1过表达慢病毒转染+30.0 mmol/L葡萄糖,D组)、高糖+阴性慢病毒转染组(阴性慢病毒转染+30.0 mmol/L葡萄糖,E组)、高糖+外泌体分泌抑制剂组(GW4869+30.0 mmol/L葡萄糖,F组)6组。采用免疫印迹法检测各组细胞Sirt1、足细胞裂孔膜蛋白(Nephrin、Podocin)及CD63、CD81、Alix的表达水平,采用实时荧光定量PCR(RT-qPCR)检测D、E组细胞Sirt 1 mRNA表达水平,使用透射电子显微镜观察足细胞外泌体形态,采用纳米粒子跟踪分析技术检测外泌体的粒径和浓度。结果RT-qPCR结果显示,D组足细胞Sirt1 mRNA相对表达量显著高于E组(t=14.580,P<0.01)。纳米粒子跟踪分析及免疫印迹结果显示,A~C组间足细胞Sirt1、Nephrin和Podocin蛋白相对表达量比较差异均具有显著性(F=49.84~106.40,P<0.01);与A组相比,C组足细胞外泌体分泌显著增加(t=14.550,P<0.01),Nephrin、Podocin、Sirt1相对表达量显著减少(t=7.446~15.110,P<0.01);与E组相比,D组足细胞外泌体分泌显著减少(t=74.610,P<0.01),Nephrin、Podocin、Sirt1相对表达量显著增加(t=4.657~32.860,P<0.05);与C组相比,F组足细胞外泌体分泌显著减少(t=16.300,P<0.05),Nephrin、Podocin相对表达量显著增加(t=3.790、8.151,P<0.01),Sirt1表达水平无统计学差异(P>0.05)。结论高糖诱导的足细胞Sirt1减少可促进外泌体分泌及足细胞损伤。

肾细胞癌源性exosomes体外诱导单核细胞分化为PD-L1髓源性抑制细胞

目的研究肾细胞癌源性exosomes诱导人外周血单核细胞分化为髓源性抑制细胞及该细胞PD-L1分子表达情况的效应。方法超滤和蔗糖重水密度梯度离心相结合的方法分离纯化肾细胞癌源性exosomes。Ficoll密度梯度离心法分离外周血单个核细胞,贴壁法获取外周血单核细胞。倒置显微镜观察获得的单核细胞形态。流式细胞仪检测单核细胞比例及活性、经exosomes诱导的单核细胞活性情况、髓源性抑制细胞(MDSCs)及其上PD-L1分子的表达情况。结果贴壁的单核细胞形状为圆形或类圆形具少许短小伪足状突起;贴壁法获得的单核细胞比例达83.5%,活细胞比例约90.0%;髓源性抑制细胞的生成较对照组明显增加[(8.91±0.21)%vs(3.19±0.91)%,P<0.05],且该髓源性抑制细胞表达PD-L1较对照组明显增高[(88.93±8.57)%vs(44.53±5.35)%,P<0.05];体外经exosomes诱导刺激的单核细胞损伤率较对照组明显升高[(39.93±16.51)%vs(12.87±2.43)%,P<0.05]。结论肾细胞癌源性exosomes在体外能够促进单核细胞损伤,诱导单核细胞分化为髓源性抑制细胞,且该髓源性抑制细胞表达PD-L1增高,可能是其抑制T细胞免疫功能的负性调节机制之一。

Exosome-transported IncRNA H19 regulates insulin-like growth factor-1 via the H19/let-7a/insulin-like growth factor-1 receptor axis in ischemic stroke

LncRNA(long non-coding RNA) H19 is a transcript of the H19 gene that is expressed during embryogenesis.We previously discove red a role for circular lncRNA H19 in the onset and prognosis of cerebral ischemic stroke.In this study,we used serum from patients with ischemic stroke,and mouse and cell culture models to elucidate the roles of plasma and neuronal exosomes in the regulatory effect of lncRNA H19 on insulin-like growth factor-1 and its mechanism in ischemic stroke,using western blotting,quantitative real-time polymerase chain reaction,and enzyme-linked immunosorbent assays.Plasma exosomal IncRNA H19 was negatively associated with blood levels of insulin-like growth factor-1 in samples from patients with cerebral ischemic stroke.In a mouse model,levels of exosomal IncRNA H19 were positively correlated with plasma and cerebral lncRNA H19.In a cell co-culture model,we confirmed that IncRNA H19 was transported from neuro ns to astrocytes by exosomes to induce downregulation of insulin-like growth factor-1 through the H19/let-7 a/insulin-like growth factor-1 receptor axis.This study provides the first evidence for the transpo rtation of IncRNA H19 by exosomes and the relationship between IncRNA H19 and insulinlike growth factor-1.

Treadmill exercise exerts a synergistic effect with bone marrow mesenchymal stem cell-derived exosomes on neuronal apoptosis and synaptic-axonal remodeling

Treadmill exercise and mesenchymal stem cell transplantation are both practical and effective methods for the treatment of cerebral ischemia.However,whether there is a synergistic effect between the two remains unclear.In this study,we established rat models of ischemia/reperfusion injury by occlusion of the middle cerebral artery for 2 hours and reperfusion for 24 hours.Rat models were perfused with bone marrow mesenchymal stem cell-derived exosomes(MSC-exos)via the tail vein and underwent 14 successive days of treadmill exercise.Neurological assessment,histopathology,and immunohistochemistry results revealed decreased neuronal apoptosis and cerebral infarct volume,evident synaptic formation and axonal regeneration,and remarkably recovered neurological function in rats subjected to treadmill exercise and MSC-exos treatment.These effects were superior to those in rats subjected to treadmill exercise or MSC-exos treatment alone.Mechanistically,further investigation revealed that the activation of JNK1/c-Jun signaling pathways regulated neuronal apoptosis and synaptic-axonal remodeling.These findings suggest that treadmill exercise may exhibit a synergistic effect with MSC-exos treatment,which may be related to activation of the JNK1/c-Jun signaling pathway.This study provides novel theoretical evidence for the clinical application of treadmill exercise combined with MSC-exos treatment for ischemic cerebrovascular disease.

Exosome-mediated transfer of circRNA563 promoting hepatocellular carcinoma by targeting the microRNA148a-3p/metal-regulatory transcription factor-1 pathway

BACKGROUND Mesenchymal stem cells(MSCs)exert anti-oncogenic effects via exosomes containing non-coding RNA(ncRNA),which play important roles in tumor biology.Our preliminary study identified the interaction of the ncRNA hsa_-circ_0000563(circ563)and the circ563-associated miR-148a-3p in exosomes,as miR-148a-3p and its target metal-regulatory transcription factor-1(MTF-1)are implicated in hepatocellular carcinoma(HCC)progression.AIM To identify the clinical significance,functional implications,and mechanisms of circ563 in HCC.METHODS The expression levels of miR-148a-3p and MTF-1 in exosomes derived from MSC and HCC cells were compared,and their effects on HCC cells were assessed.Using a dual-luciferase reporter assay,miR-148a-3p was identified as an associated microRNA of circ563,whose role in HCC regulation was assessed in vitro and in vivo.RESULTS The silencing of circ563 blocked the HCC cell proliferation and invasion and induced apoptosis.Co-culturing of HCC cells with MSC-derived exosomes following circ563 overexpression promoted cell proliferation and metastasis and elicited changes in miR-148a-3p and MTF-1 expression.The tumor-promoting effects of circ563 were partially suppressed by miR-148a-3p overexpression or MTF-1 depletion.Xenograft experiments performed in nude mice confirmed that circ563-enriched exosomes facilitated tumor growth by upregulating the expression of MTF-1.In HCC tissues,circ563 expression was negatively correlated with miR-148a-3p expression but positively correlated with MTF-1 levels.CONCLUSION MSCs may exhibit anti-HCC activity through the exosomal circ563/miR-148a-3p/MTF-1 pathway,while exosomes can transmit circ563 to promote oncogenic behavior by competitively binding to miR-148a-3p to activate MTF-1.

Exosome-derived miR-146a-5p from decidual macrophages in preeclampsia inhibits the viability and invasive ability of trophoblast cells by targeting HIF1α

Objective:To investigate the effect of exosomes secreted by decidual macrophages on trophoblast cells and their molecular mechanism.Methods:The decidual tissues of patients with preeclampsia(PE)and normal-term pregnant women were collected.Macrophages were obtained by the density gradient method and then flow cell sorting,then the exosomes were extracted.The structure of the exosomes was observed by transmission electron microscope.The expression of CD63,a marker protein of the exocrine body,was detected by western blot,and the exosomes were identified.CCK-8 was used to detect the effect of exosomes on trophoblast cell viability.Transwell migration experiment was used to detect the influence on migration ability.The expression of miR-146a-5p in exosomes was detected by qPCR.The effect of exosomes on the expression of HIF1αprotein in trophoblasts was detected by western blot and detection of the binding site between miR-146a-5p and HIF1αby double luciferase reporter gene was conducted.Results:The exosomes of macrophages present a"cake"structure with a middle depression about 30-130 nm in diameter,and CD63 is highly expressed,which conforms to the characteristics of exosomes.Compared with the normal group,the exosomes of decidual macrophages in the PE group inhibited the activity and migration of trophoblast cells(P<0.001).The expression of miR-146a-5p in the exosomes of decidual macrophages in the PE decreased significantly,and after exosomes of PE decidual macrophages treating trophoblast cells,the protein expression of HIF1αin trophoblast cells was significantly increased.There are targeted binding sites between miR-146a-5p and HIF1α.Conclusion:PE decidual macrophage exosomes can inhibit the viability and migration of trophoblast cells,which may be related to the decreased expression of miR-146a-5p in exosomes,thus promoting HIF1αprotein expression of trophoblast cells.

外泌体负载的KV11通过VDAC1和自噬机制对角膜新生血管的抑制作用

目的探讨外泌体(EXO)负载的抗新生血管短肽KV11在角膜新生血管(CNV)中的作用及其机制。方法利用EXO锚定肽CP05将KV11结合到血管内皮来源的EXO膜表面,形成EXO-KV11。通过Apogee纳米流式分析EXO负载KV11的效率和最佳浓度比。选取8周龄SPF级健康雄性SD大鼠100只,其中10只大鼠不做任何处理,为正常对照组;其余大鼠在建立碱烧伤诱导CNV大鼠模型后,采用随机数字表法随机将大鼠分为EXO-KV11组、KV11组和生理盐水组,每组各30只。从碱烧伤后第1天开始每隔1天,各组分别结膜下注射100μl EXO-KV11(25μg)、KV11(25μg)或生理盐水。观察第1、4、7、14天时CNV的生成情况;采用荧光素心室灌注、角膜血管造影法计算CNV面积;采用苏木精-伊红染色法观察各组CNV管腔数量;采用免疫组织化学法检测角膜组织中CD31的表达分布;采用Western blot法检测电压依赖性阴离子通道1(VDAC1)和内质网应激、自噬及凋亡相关蛋白的表达水平。结果Apogee流式分析确定KV11与EXO最佳浓度比为4∶1,EXO负载KV11效率高达87.5%。碱烧伤后7 d和14 d,各组CNV面积总体比较差异均有统计学意义(F=4.613、15.590,均P<0.05),其中碱烧伤后7 d,EXO-KV11组CNV面积小于KV11组和生理盐水组;碱烧伤后14 d,EXO-KV11组和KV11组CNV面积均小于生理盐水组,EXO-KV11组CNV面积小于KV11组,差异均有统计学意义(均P<0.05)。角膜荧光铺片定量分析结果显示,生理盐水组、KV11组和EXO-KV11组CNV相对荧光面积分别为(8.3±1.7)%、(5.2±1.6)%和(3.4±0.7)%,总体比较差异有统计学意义(F=11.735,P<0.01),其中KV11组和生理盐水组CNV相对荧光面积均大于EXO-KV11组,生理盐水组CNV相对荧光面积大于KV11组,差异均有统计学意义(均P<0.05)。碱烧伤后14 d,生理盐水组基质内可见大量新生血管管腔;KV11组基质内新生血管管腔数量较生理盐水组少;EXO-KV11组角膜结构趋于正常,少见新生血管管腔。生理盐水组角膜基质内可见大量CD31染色阳性细胞,细胞围成大小不一的管腔结构;KV11组角膜基质内CD31染色阳性细胞围成的管腔数量较生理盐水组少,EXO-KV11组管腔数量较KV11组少。EXO-KV11组、KV11组、生理盐水组和正常对照组VDAC1、蛋白质激酶R样内质网激酶(PERK)、自噬接头蛋白(SQSTM1/p62)、活化半胱氨酸蛋白酶3(cleaved caspase 3)相对表达量总体比较差异均有统计学意义(F=35.960、8.947、17.791、101.168,均P<0.01),其中EXO-KV11组VDAC1、PERK、p62、cleaved caspase 3相对表达量高于KV11组和生理盐水组,差异均有统计学意义(均P<0.001)。各组自噬微管相关蛋白轻链3B(LC3B)Ⅱ/LC3BⅠ蛋白相对表达量总体比较,差异无统计学意义(F=0.445,P=0.727)。结论与KV11相比,EXO-KV11可通过增加VDAC1表达、刺激PERK产生、抑制自噬流的发生等机制更有效地抑制CNV。

The gene expression level and prognosis analysis of membrane protein AP2M1 based on the protein spectrum of exosomes in hepatocellular carcinoma cells

Objective:Adopting mass spectrometry to analyze the protein spectrum of the exosomes in human hepatocellular carcinoma cells and screening the target membrane protein in order to analyze the relationship between its gene expression level and prognosis.Methods:The exosomes of hepatocellular carcinoma cells HepG2 and 7721 were isolated by ultracentrifugation,and the extracted exosomes were verified by transmission electron microscope, western blotting,and nanosight.The relative quantitative proteomics analysis was used to analyze the protein spectrum of HepG2 and 7721 cells in exosomes.The bioinformatics was used to collect the signal pathway,and the target protein AP2M1 was verified by qRTPCR.Gene Expression Profiling Interactive Analysis(GEPIA),OncoLnc,and The Cancer Genome Atlas(TCGA)database were used to analyze the expression level of AP2M1 and the survival rate of patients with liver cancer.Results:The extracellular exosomes of HepG2 and 7721 cells were isolated by ultracentrifugation.High-purity exosomes were obtained and verified by transmission electron microscopy,western blotting,and nanosight.There were 836 proteins co-expressed by the exosomes of HepG2 and 7721.By the analysis of Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway,a total of 34 pathways that were related to liver cancer were collected,and the target membrane protein AP2M1 was screened.AP2M1 highly expressed in HepG2 cells,HepG2 and Huh7 cells' exosomes were detected by qRT-PCR(P<0.05).The data of GEPIA showed that comparing to the adjacent tissues,gene AP2M1 was highly expressed in hepatocarcinoma tissues.Kaplan-Meier survival curve analysis was performed by OncoLnc.It was found that the survival rate of patients with liver cancer and high expression of AP2M1 was significantly lower than patients with liver cancer and low expression of AP2M1(P<0.01).Conclusion:The high expression of membrane protein AP2M1 in the exosomes of hepatoma cells and the high expression of its gene in liver cancer tissues predicted the low survival rate.

间充质干细胞在1型糖尿病胰岛移植中的应用进展

胰岛移植被认为是治疗1型糖尿病的有效方法之一,但其疗效受到多种因素限制。胰岛在分离、培养和移植过程中的缺氧、应激及排斥反应,都会影响胰岛移植的结局。间充质干细胞(MSC)因其抗炎、促进血管生成和调节免疫代谢等生物特性,一直备受研究者关注。此外,MSC的衍生物如外泌体在调节缺氧诱导的氧化应激、促进机体血管形成和调节免疫方面也具有重要作用。基于MSC的胰岛移植可能是1型糖尿病的有效治疗方法。因此,本文就MSC在胰岛移植前后发挥的潜在作用进行综述,并探讨其临床应用及局限性,以期为今后胰岛移植治疗1型糖尿病的相关研究提供新的思路和见解。

过表达miR-124-1基因的骨髓间充质干细胞外泌体调控小胶质细胞M2型极化对脑卒中的影响

目的探讨骨髓间充质干细胞(bone marrow derived mesenchymal stem cells,BMMSCs)外泌体(exosomes,Exo)过表达miR-124-1基因(Exo/124-1)调控小胶质细胞(microglia,MG)的M2型极化对脑卒中的影响。方法分离培养大鼠BMMSCs,收集其Exo(BMMSCs-Exo),采用流式细胞术、Western blot与透射电子显微镜(transmission electron microscope,TEM)分别对其进行检测鉴定。30只大鼠简单随机分为假手术组(Sham组)、模型组(MCAO/R组)、Exo移植组(Exo组)、空病毒(Empty lentivirus,Elv)转染Exo移植组(Exo-Elv组)及Exo/124-1移植组(Exo/124-1组),每组6只。Sham组仅行假手术,其余各组均复制大脑中动脉栓塞/再灌注(middle cerebral artery occlusion and reperfusion,MCAO/R)模型。模型复制1 d与14 d后,各移植组动物于右侧脑室植入相应移植物,Sham组、模型组注入相同剂量生理盐水作对照。术后2 h及1、3、7、14、21、28 d,分别对各组动物行改良神经系统严重程度评分(modified neurological severity scores,mNSS)。三苯基四氮唑(triphenyl tetrazolium chloride,TTC)染色检测其梗死体积。在基因与蛋白水平分别检测各组28 d脑组织MG的M1型分子[肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)]、M2型分子(CD206)的表达情况。结果成功获取并鉴定了BMMSCs及其Exo。Exo/124-1显著表达miR-124-1。所有动物(假手术组除外)术后出现神经功能缺损。术后7~28 d,Exo/124-1组的mNSS明显低于MCAO/R组(P<0.05)与Exo组、Exo-Elv组(P<0.01);术后28 d,Exo/124-1组的脑梗死体积、TNF-α的表达明显小于MCAO/R组(P<0.01)与Exo组、Exo-Elv组(P<0.01),CD206的表达显著高于MCAO/R组(P<0.01)与Exo组、Exo-Elv组(P<0.01)。结论BMMSCs-Exo携带miR-124-1基因可能调控MG的M2型极化,抑制M1型介导的炎症反应,促进脑卒中大鼠神经功能的恢复。

内质网应激头颈部鳞状细胞癌细胞通过外泌体miR⁃26a⁃5p调控PTEN/AKT通路促进巨噬细胞PD⁃L1表达

目的探讨内质网应激(endoplasmic reticulum stress,ERS)的头颈部鳞状细胞癌(head and neck squa⁃mous cell carcinoma,HNSCC)细胞分泌的外泌体miRNA表达变化对巨噬细胞的影响机制。方法本研究已通过单位伦理委员会审查批准。通过蛋白质免疫印迹(Western blot,WB)和实时荧光定量PCR实验(RT⁃qPCR)检测HNSCC肿瘤组织及癌旁组织ERS相关蛋白,包括蛋白激酶R样内质网激酶(protein kinase R⁃like endoplas⁃mic reticulum kinase,PERK)和葡萄糖调节蛋白78(glucose⁃regulated protein 78,GRP78)的表达水平;以500 U/mL干扰素⁃γ(interferon⁃γ,IFN⁃γ)处理人喉鳞癌细胞系HN4细胞48 h,诱发HN4细胞产生内质网应激反应,收集HN4细胞分泌的外泌体,通过生物信息学分析鉴定外泌体的miRNA种类,预测miRNA的靶基因,将巨噬细胞转染miRNA、与收集的外泌体共培养、并敲低巨噬细胞PTEN表达,以WB和RT⁃qPCR检测外泌体miRNA调控的下游信号通路蛋白酪氨酸磷酸酶(phosphate and tension homology deleted on chromsome ten,PTEN)/蛋白激酶B(protein kinase B,AKT)及程序性死亡受体⁃1配体(programmed death receptor ligand 1,PD⁃L1)表达变化。结果HNSCC肿瘤组织相比癌旁组织ERS相关蛋白表达水平升高(P<0.05);RNA测序及实验验证表明ERS的HN4细胞分泌的外泌体miR⁃26a⁃5p表达上调(P<0.05);PTEN是miR⁃26a⁃5p的靶基因,miR⁃26a⁃5p升高巨噬细胞PD⁃L1表达水平,并下调PTEN表达(P<0.05);巨噬细胞与ERS外泌体共培养,miR⁃26a⁃5p和PD⁃L1表达上升,PTEN表达下降,p⁃AKT表达升高(P<0.05);敲低巨噬细胞PTEN表达,PD⁃L1表达上升(P<0.01)。结论ERS的HNSCC细胞通过外泌体miR⁃26a⁃5p调控PTEN/AKT通路及PD⁃L1的表达。

胃癌外体(exosome)内miRNA-1的检测分析

目的检测胃癌细胞系来源外体（exosome）及其胃癌组织和血清中exosome内miRNA-1的表达水平并分析其临床意义。方法采用实时荧光定量RT-PCR分别检测胃癌细胞系来源exosome、胃癌患者组织及血清exosome内miRNA-1的表达水平,分析其与临床资料相关性,并绘制ROC曲线进行效能分析。结果 miRNA-1在人胃癌细胞系MGC-803（6.51±0.41）和SGC-7901（14.81±1.30）中的含量明显高于胃上皮细胞系GES-1（1.05±0.25）,差异有统计学意义（t分别为11.26、10.38,P均〈0.01）;而MGC-803、SGC-7901细胞培养上清exosome内miRNA-1的表达水平（49.98±11.77和28.68±4.66）显著高于GES-1来源exosome（1.00±0.02）差异有统计学意义（t分别为4.162、5.942,P均〈0.01）;25对胃癌组织标本中有18例癌组织miRNA-1表达上调,7例表达下调,胃癌组织[1.110（0.070,4.307）]平均表达水平高于癌旁组织[1.149（1.110,2.075）],差异有统计学意义（Z=-1.897,P〈0.05）。miRNA-1在胃癌患者血清exosome内的表达水平[4.130（0.151,12.720）]较体检健康者血清exosome内表达水平[0.704（0.077,7.243）]明显增高（Z=-2.407,P〈0.05）,且与胃癌的淋巴结转移相关;胃癌患者血清exosome内miRNA-1的ROC曲线下面积（AUC^ROC）为0.723 0,95%可信区间（CI）为0.627 0～0.818 7,cut off值为2.39,敏感性为66%,特异性为68%。结论胃癌组织及其胃癌患者血清来源exosome内富含miRNA-1,有望成为新的胃癌诊断标志物。