miR-708-5p通过抑制TMEM88表达促进人骨髓间充质干细胞迁移

目的:研究年龄相关microRNA-708-5p(miR-708-5p)对人骨髓间充质干细胞(h MSCs)迁移能力的调控作用。方法:通过microRNA芯片和real-time PCR检测供体年龄对h MSCs中miR-708-5p表达的影响;通过转染miR-708-5p模拟物或抑制物,过表达或抑制miR-708-5p表达;通过细胞划痕及Transwell实验检测h MSCs迁移能力。通过siRNA研究miR-708-5p靶基因跨膜蛋白88(TMEM88)对h MSCs中β链球蛋白(β-catenin)及h MSCs迁移功能的影响。结果:随供体年龄增加,h MSCs中miR-708-5p的表达下降。过表达miR-708-5p可促进h MSCs迁移。相反,抑制miR-708-5p的表达可减少h MSCs迁移。随供体年龄增加,TMEM88表达增加,而β-catenin表达下降,直接抑制TMEM88的表达可促进β-catenin表达,促进h MSCs迁移。同时抑制miR-708-5p和TMEM88,使miR-708-5p失去对h MSCs的调控作用。结论:miR-708-5p可通过抑制TMEM88表达,上调β-catenin,从而活化Wnt/β-catenin信号通路,促进h MSCs迁移。     

miR-486-5p在氧化应激引起人骨髓间充质干细胞凋亡中的作用

目的:观察microRNA-486-5p(miR-486-5p)在氧化应激引起人骨髓间充质干细胞(h MSCs)凋亡中的作用并探讨其作用机制。方法:h MSCs经培养鉴定后分为5组:空白对照组、H2O2组、miR-486-5p模拟物+H2O2组、抑制物(αnti-miR)+H2O2组及相应的阴性对照(scrambled control)+H2O2组。荧光定量PCR(real-time PCR)检测氧化应激诱导h MSCs凋亡过程中miR-486-5p的表达变化。用脂质体分别转染miR-486-5p的模拟物、抑制物及阴性对照到h MSCs。应用MTT、Hoechst标记和流式细胞术的方法检测miR-486-5p对氧化应激介导细胞活性下降及凋亡效应的影响,Western blotting检测凋亡相关蛋白、Akt与其磷酸化水平,采用试剂盒测定caspase-3活性。结果:H2O2诱导h MSCs凋亡过程中miR-486-5p的表达较对照组显著下降(P0.05)。与阴性对照组相比,在h MSCs中过表达miR-486-5p,能使细胞在氧化应激情况下活性显著下降,凋亡发生率增高,蛋白Bcl-2/Bax比值、caspase-3酶原含量及Akt磷酸化水平降低,caspase-3活性增强;而使用抑制物阻遏miR-486-5p的作用后,细胞在氧化应激条件下活性增加,凋亡发生率降低,蛋白Bcl-2/Bax比值及Akt磷酸化水平升高,caspase-3活性下降。结论:过表达miR-486-5p促进氧化应激引起的h MSCs凋亡,阻遏miR-486-5p的作用抑制氧化应激条件下的h MSCs凋亡,其中作用机制可能与调控Akt通路有关。     

miR-9-5p通过抑制SIRT1调控骨关节炎发病进程中软骨细胞的凋亡

为研究miR-9-5p靶向沉默信息调节因子2相关酶1(silent information regulator factor 2-related enzyme 1, SIRT1)对骨关节炎(osteoarthritis, OA)软骨细胞凋亡的影响及相关机制,对小鼠的原代软骨细胞进行分离、培养并构建OA细胞模型(加入IL-1β)和OA小鼠模型,检测miR-9-5p的表达、Caspase-3活性、细胞活性及凋亡。确定miR-9-5p和SIRT1存在靶向关系后检测SIRT1活性和上述指标。用番红O-固绿对OA小鼠组织进行染色并分析,在OA小鼠模型中再次验证miR-9-5p通过抑制SIRT1对软骨细胞凋亡的影响。结果显示,miR-9-5p mRNA在OA组织及IL-1β处理的软骨细胞中表达显著升高(P<0.001), miR-9-5p可抑制OA软骨细胞活性(P<0.001)并促进其凋亡(P<0.01)。miR-9-5p靶向作用于SIRT1,并通过抑制SIRT1抑制OA软骨细胞活性(P<0.001),促进其凋亡(P<0.05)。在OA动物模型的验证中得到相同的结果。...     

MicroRNA-378*通过抑制CTGF促进人骨髓间充质干细胞凋亡

 目的:研究年龄相关microRNA-378* (miR-378*) 对人骨髓间充质干细胞（hMSCs）存活和凋亡的调控作用。方法:通过microRNA芯片和qRT-PCR检测供体年龄对hMSCs 中miR-378*表达的影响;通过H2O2诱导hMSCs凋亡;通过转染miR-378*模拟物或抑制物,过表达或抑制miR-378*的表达;用MTT、LDH、caspase-3/7、TUNEL检测等方法研究其对hMSCs存活和凋亡的影响;通过siRNA研究结缔组织生长因子（CTGF）对hMSCs存活和凋亡的影响。结果: 随供体年龄增加,hMSCs 中miR-378*的表达增加。H2O2刺激可促进miR-378*表达,抑制CTGF表达。过表达miR-378*可减少hMSCs的存活,促进细胞凋亡。相反,抑制miR-378*的表达促进hMSCs的存活,减少细胞凋亡。同时抑制miR-378*和CTGF的表达,使miR-378*失去对hMSCs存活和凋亡的调控作用。直接抑制CTGF的表达可减少hMSCs的存活,促进细胞凋亡。结论: miR-378*通过抑制CTGF的表达减少hMSCs存活,促进hMSCs凋亡。     

微小RNA-199a-5p通过靶向SIRT1促进心肌纤维化相关基因表达

目的:研究微小RNA-199a-5p(miR-199a-5p)对心肌成纤维细胞中纤维化相关基因表达的调控作用及其可能作用的靶基因。方法:原代分离并体外培养成体C57BL/6小鼠心肌成纤维细胞;双萤光素酶报告基因实验检测miR-199a-5p与潜在靶基因沉默信息调节因子1(SIRT1)3’端非翻译区(3’-UTR)的结合作用;实时荧光定量PCR(RT-q PCR)和Western blot法分别检测SIRT1以及纤维化标志物胶原蛋白(Col)1a1、Col3a1和α-平滑肌肌动蛋白(α-SMA)的mRNA和蛋白表达。结果:在血管紧张素Ⅱ(AngⅡ)诱导的小鼠心肌成纤维细胞中,Col1a1、Col3a1和α-SMA的表达增强,miR-199a-5p表达上调。在心肌成纤维细胞中过表达miR-199a-5p可以增强Col1a1、Col3a1和α-SMA的表达。双萤光素酶报告基因实验显示miR-199a-5p与SIRT1 3’-UTR有结合作用。RT-q PCR和Western blot结果证实miR-199a-5p可在转录水平抑制SIRT1表达。过表达miR-199a-5p和沉默SIRT1均能一致性促进心肌成纤维细胞中Col1a1、Col3a1和α-SMA的表达。抑制AngⅡ诱导的小鼠心肌成纤维细胞中NF-κB激活,可显著降低miR-199a-5p表达。结论:SIRT1是miR-199a-5p的作用靶基因,并介导miR-199a-5p促进纤维化标志物Col1a1、Col3a1和α-SMA的表达。     

MiR-486-5p在肝癌中的表达及其对肝癌细胞生长的影响

本研究旨在探讨肝癌中miR-486-5p的表达及其对肝癌细胞生长的影响。首先,通过qRT-PCR对40例肝癌患者的肝癌组织及其癌旁组织、以及肝癌细胞系(QGY-7701、QGY-7703、BEL-7404、SMMC-7721、Huh7、HepG2和PCL/PRF/5)进行miR-486-5p表达水平的验证;然后,合成miR-486-5p模拟物及其阴性对照物NC,分别转入上述七种肝癌细胞,采用CCK8试剂检测miR-486-5p对肝癌细胞生长的影响;最后,采用流式细胞术检测miR-486-5p对肝癌细胞周期和细胞凋亡的影响。结果显示,与miRNA第二代高通量大规模平行测序(miRNomes MPSS)结果一致,miR-486-5p在肝癌组织和肝癌细胞中显著低表达(P0.05)。CCK8检测结果表明,转染miR-486-5p模拟物能有效、稳定的抑制上述七种肝癌细胞的生长(P0.05)。流式细胞仪检测发现,过表达miR-486-5p能促进肝癌细胞凋亡(QGY-7703细胞,P0.001;QGY-7701细胞,P0.01),及诱导细胞周期阻滞在G1期(P0.01)。研究结果表明,miR-486-5p在肝癌组织中低表达;重建肝癌细胞内miR-486-5p的表达,可有效诱导肝癌细胞周期阻滞和凋亡,从而抑制肝癌细胞生长,提示miR-486-5p可能在肝癌的发生发展中起着重要作用。     

雌二醇通过ERα抑制miR-16表达并促进蜕膜间充质干细胞生长

目的:研究雌二醇(E2)通过调控微小RNA-16(miR-16)的表达对胎盘蜕膜来源间充质干细胞(MSCs)活力的影响。方法:分别检测E2在正常孕妇及重度子痫前期(PE)患者外周血中的浓度。CCK-8法分析不同浓度E2对MSCs活力的影响。Real-time PCR分析不同浓度E2处理MSCs对miR-16表达的影响。探索E2通过何种受体调控miR-16表达。结果:与正常孕妇相比,重度PE患者外周血中E2浓度显著降低(P0.01)。5、10和100 nmol/L E2分别处理MSCs 48 h后,MSCs活力显著增加(P0.05)。5、10和100 nmol/L E2分别处理MSCs12 h后,miR-16的表达水平下调(P0.05),而用10 nmol/L E2处理MSCs不同时间(0 h、3 h、6 h、12 h和24 h)后,miR-16表达水平随着时间呈现明显下调趋势。在E2处理之前预先转染miR-16,细胞活力被显著逆转。E2处理MSCs之前6 h,用雌激素受体拮抗剂ICI 182780和他莫昔芬预预处理,E2对miR-16失去抑制作用。雌激素受体α(ERα)激动剂丙基吡唑三醇(PPT)及ERβ受体激动剂二芳基丙腈DPN分别处理MSCs后,仅PPT可明显抑制miR-16表达。结论:雌二醇可能通过ERα抑制miR-16表达,从而促进蜕膜MSCs的生长。     

SENP3对大鼠成骨细胞端粒酶活性及端粒长度的影响

目的:研究sentrin特异性蛋白酶3(SENP3)对大鼠成骨细胞端粒酶活性及端粒长度的影响。方法:首先0.2 mmol/L H_2O_2处理体外培养的大鼠成骨细胞后,Western blotting法检测SENP3及特异性蛋白1(Sp1)的表达。pc DNA3.0-SENP3转染成骨细胞,分别于24 h、48 h、72 h后采用四甲基偶氮唑蓝(MTT)法检测细胞活力的变化。转染48 h后,Western blotting法检测Sp1和端粒酶逆转录酶(TERT)的表达,PCR-TRAP法及PCR法检测端粒酶活性及端粒长度;ELISA检测上清中碱性磷酸酶(ALP)和骨桥蛋白(OPN)的含量;放射免疫法(RIA)检测骨钙蛋白(OCN)的含量。最后将pc DNA3.0-SENP3与siRNA-Sp1共转染成骨细胞,并检测以上指标。结果:H_2O_2处理成骨细胞后,SENP3和Sp1的表达显著上升。pc DNA3.0-SENP3转染成骨细胞后,Sp1和TERT的表达显著上升,细胞活力、ALP、OPN及OCN含量也都显著上升;端粒酶活性显著增加及端粒长度缩短显著延缓。而当pc DNA3.0-SENP3与siRNA-Sp1共转染成骨细胞后,细胞活力,ALP、OPN及OCN含量,端粒酶活性及端粒长度均未发生显著变化。结论:SENP1通过上调Sp1的表达促进TERT的表达,增加端粒酶活性上升及延缓端粒长度缩短,从而增强成骨细胞增殖能力。     

miR-30a-5p靶向SIRT1调控骨关节炎软骨细胞增殖和凋亡的研究

为研究miR-30a-5p对骨关节炎(osteoarthritis,OA)软骨细胞增殖和凋亡的影响并探讨其机制,运用实时荧光RT-PCR检测人原代OA软骨细胞及正常软骨细胞中miR-30a-5p、沉默信息调节因子2相关酶Ⅰ(silent information regulator 1, SIRT1)的表达。研究分为正常对照组(正常软骨细胞)、OA+anti-miR-NC组(转染anti-miR-NC)、OA+anti-miR-30a-5p组(转染anti-miR-30a-5p)、OA+pcDNA组(转染pcDNA)、OA+pcDNA-SIRT1组(转染pcDNA-SIRT1)、OA+anti-miR-30a-5p+si-NC组(anti-miR-30a-5p和si-NC共转染)、OA+anti-miR-30a-5p+si-SIRT1组(anti-miR-30a-5p和si-SIRT1共转染),用脂质体法进行细胞转染,Western blotting检测各组细胞中SIRT1的表达,MTT试验检测细胞的增殖能力,流式细胞术检测细胞的凋亡情况,双荧光素酶报告基因检测试验检测细胞的荧光活性。结果显示,与正常软骨细胞比较,OA软骨细胞中miR-30a-5p表达显著升高(P0.05),SIRT1表达显著降低(P0.05);抑制miR-30a-5p、过表达SIRT1均可促进OA软骨细胞增殖,抑制其凋亡。miR-30a-5p靶向SIRT1。敲减SIRT1表达可逆转抑制miR-30a-5p对OA软骨细胞的增殖促进和凋亡抑制作用。提示miR-30a-5p可促进OA软骨细胞增殖,抑制其凋亡,其机制可能与靶向SIRT1有关,这可为OA的靶向治疗提供依据。     

miR-34a通过SIRT1诱导高糖条件下骨髓间充质干细胞衰老

目的:研究微小RNA-34a(microRNA-34a,miR-34a)对高糖条件下骨髓间充质干细胞(bone marrow-derived mesenchymal stem cells,BMSCs)衰老的调控及潜在机制。方法:从60～80 g的雄性SD大鼠骨髓中分离和培养BMSCs,将细胞分为5组:正常葡萄糖(NG)组、高糖(HG)组、HG+miR-34a mimic组、HG+miR-34a NC组和HG+miR-34a inhibitor组;为了探究miR-34a是否通过沉默信息调节因子1(silent information regulator 1, SIRT1)调控高糖条件下BMSCs的衰老水平,除了上述5组,另增加HG+siRNA-SIRT1组、HG+siRNA-NT组和HG+miR-34a inhibitor+siRNA-SIRT1组。RT-qPCR法检测各组细胞中miR-34a及SIRT1 mRNA的表达,CCK-8法检测细胞的活力,衰老相关β-半乳糖苷酶染色法检测细胞的衰老情况,Western blot检测SIRT1、叉头框蛋白O3a(forkhead boxO3a, FOXO3a)和P21蛋白的表达。结果:与NG组相比,HG组miR-34a表达明显上调(P0.01),细胞活力减弱(P0.05),衰老细胞明显增加(P0.01);与HG+miR-34a NC组相比,HG+miR-34a mimic组的细胞活力明显减弱(P0.01),衰老细胞明显增加(P0.01),SIRT1蛋白表达明显降低(P0.01),FOXO3a蛋白表达明显升高(P0.01),HG+miR-34a inhibitor组上述各参数则表现相反;与HG组相比,HG+siRNA-SIRT1组P21及FOXO3a蛋白表达均明显升高(P0.01),当向HG+miR-34a inhibitor组加入siRNA-SIRT1后,miR-34a inhibitor对高糖条件下BMSCs中P21及FOXO3a蛋白表达的抑制作用被部分减弱(P0.05)。结论:miR-34a通过靶向调节SIRT1的表达实现对高糖条件下BMSCs衰老的调控。     

miR-486-5p induces replicative senescence of human adipose tissue-derived mesenchymal stem cells and its expression is controlled by high glucose

The reduction of adult stem cell self-renewal can be an important mechanism of aging. MicroRNAs have been reported to be involved in aging processes. Through a microarray approach, we have identified miR-486-5p, the expression of which is progressively expressed in human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) with aging. Overexpression of miR-486-5p induces a premature senescence-like phenotype and inhibits proliferation of hAT-MSCs and inhibits adipogenic and osteogenic differentiation, whereas inhibition of miR-486-5p has the opposite effects. miR-486-5p regulates the expression of silent information regulator 1 (SIRT1), a major regulator of longevity and metabolic disorders. Decrease of SIRT1 deacetylase activity in hAT-MSCs is correlated with their passage number. miR-486-5p inhibits SIRT1 expression through a miR-486-5p binding site within the 3'-untranslated region of SIRT1. Overexpression of miR-486-5p inhibits SIRT1 deacetylase activity in hAT-MSCs, and transfection of miR-486-5p inhibitor shows the opposite effect. Downregulation of SIRT1 in hAT-MSCs induces senescence and inhibits cell proliferation. Exposure to high glucose increases miR-486-5p expression and inhibits SIRT1 expression in hAT-MSCs. Our data pinpoint miR-486-5p as an endogenous inhibitor of SIRT1 that promotes hAT-MSCs senescence and is potentially applicable to therapeutic manipulation of hAT-MSCs dysfunction in metabolic disorders.     

MicroRNA-196a通过HOXB7调控人骨髓间充质干细胞的增殖功能

 目的:研究年龄相关microRNA-196a (miR-196a) 对人骨髓间充质干细胞（hMSCs）增殖功能的调控作用。方法:通过MTT研究年龄对hMSCs增殖能力的影响。通过microRNA芯片和qRT-PCR检测年龄对miR-196a表达的影响。通过转染miR-196a模拟物或抑制物,研究其对hMSCs增殖能力的影响。通过萤光素酶报告基因系统证实HOXB7为miR-196a的靶基因。通过siRNA研究HOXB7对碱性成纤维细胞生f长因子(bFGF)表达及hMSCs增殖功能的影响和研究bFGF对hMSCs增殖功能的影响。结果:随年龄增加,hMSCs的增殖能力下降,miR-196a的表达增加。miR-196a可抑制hMSCs的增殖。抑制miR-196a的表达可促进hMSCs的增殖。同时抑制miR-196a和HOXB7的表达,使miR-196a失去对hMSCs增殖能力的调控作用。抑制HOXB7的表达可使bFGF的表达下调。直接抑制HOXB7或bFGF的表达可抑制hMSCs的增殖。结论:miR-196a通过抑制HOXB7及bFGF的表达导致hMSCs增殖能力下降。     

miR-150-5p靶向SIRT1提高肝癌细胞系HepG2放疗敏感性

目的探究miR-150-5p靶向SIRT1提高肝癌细胞放射敏感性的作用机制。方法用分次放疗放射递增法诱导建立放射抵抗型细胞株(RR-HepG2);RT-qPCR检测HepG2和RR-HepG2在不同放射剂量下miR-150-5p的表达水平;细胞克隆实验检测相同放射剂量下两种细胞的放疗敏感性;流式细胞计量术和Western blot检测过表达miR-150-5p对HepG2凋亡的影响;双荧光素酶报告基因法检测miR-150-5p与SIRT1的关联;细胞克隆实验和Western blot检测过表达SIRT1后,细胞的放疗敏感性和凋亡蛋白的变化。结果与亲代HepG2比较,相同放射剂量下,RRHepG2组miR-150-5p的表达量均显著降低(P<0. 05);放射处理后,与control、agomiR-NC组比较,agomiR-150-5p组的细胞存活分数显著降低,敏感性高(P<0. 05),Bax、caspase-9蛋白表达水平显著升高,Bcl-2蛋白表达水平显著降低,细胞凋亡率显著升高;双荧光素酶报告基因法验证miR-150-5p靶向调控SIRT1。与agomiR-NC组比较,野生型(WT) agomiR-150-5p荧光素酶活性显著降低,SIRT1蛋白水平显著降低(P<0. 05);与anta-agomiR-NC比较,野生型(WT) anta-agomiR-150-5p荧光素酶活性显著升高,SIRT1蛋白水平显著升高(P<0. 05);放射处理后,与agomiR-NC组比较,agomiR-150-5p组的细胞存活分数显著降低,Bax、caspase-9蛋白表达水平显著升高,Bcl-2蛋白表达水平显著降低(P<0. 05);与agomiR-150-5p+vector组比较,agomiR-150-5p+SIRT1组的细胞存活分数显著升高,Bax、caspase-9蛋白表达水平显著降低,Bcl-2蛋白表达水平显著升高(P<0. 05)。结论 miR-150-5p靶向SIRT1,下调其表达,提高肝癌细胞放射敏感性,可为临床肝癌放射治疗增敏提供靶点。     

Nanoparticle delivery of stable miR-199a-5p agomir improves the osteogenesis of human mesenchymal stem cells via the HIF1a pathway

Elucidating the regulatory mechanisms of osteogenesis of human mesenchymal stem cell (hMSC) is important for the development of cell therapies for bone loss and regeneration. Here we showed that hsa-miR-199a-5p modulated osteogenic differentiation of hMSCs at both early and late stages through HIF1a pathway. hsa-miR-199a expression was up-regulated during osteogenesis for both of two mature forms, miR-199a-5p and -3p. Over-expression of miR-199a-5p but not -3p enhanced differentiation of hMSCs in vitro, whereas inhibition of miR-199a-5p reduced the expression of osteoblast-specific genes, alkaline phosphatase (ALP) activity, and mineralization. Furthermore, over-expression of miR-199a enhanced ectopic bone formation in vivo. Chitosan nanoparticles were used for delivery of stable modified hsa-miR-199a-5p (agomir) both in vitro and in vivo, as a proof-of-concept for stable agomir delivery on bone regeneration. The hsa-mir199a-5p agomir were mixed with Chitosan nanoparticles to form nanoparticle/hsa-mir199a-5p agomir plasmid (nanoparticle/agomir) complexes, and nanoparticle/agomir complexes could improve the in vivo regeneration of bone. Further mechanism studies revealed that hypoxia enhanced osteogenesis at early stage and inhibited osteogenesis maturation at late stage through HIF1a-Twist1 pathway. At early stage of differentiation, hypoxia induced HIF1a-Twist1 pathway to enhance osteogenesis by up-regulating miR-199a-5p, while at late stage of differentiation, miR-199a-5p enhanced osteogenesis maturation by inhibiting HIF1α-Twist1 pathway.     

β-catenin-coordinated lncRNA MALAT1 up-regulation of ZEB-1 could enhance the telomerase activity in HGF-mediated differentiation of bone marrow mesenchymal stem cells into hepatocytes

Objective

To investigate role of β-catenin and lncRNA MALAT1/miR-217 axis to converge into the regulation of ZEB-1 in hepatocyte growth factor (HGF)-induced hepatocytes differentiated from bone marrow mesenchymal stem cells (BM-MSCs).

Increased caveolin-1, a cause for the declined adipogenic potential of senescent human mesenchymal stem cells

Mesenchymal stem cell (MSC) has drawn much attention in the aspect of tissue renewal and wound healing because of its multipotency. We initially observed that bone marrow-derived human MSCs (hMSCs) divided poorly and took flat and enlarged morphology after expanded in culture over a certain number of cell passage, which resembled characteristic features of senescent cells, well-studied in human diploid fibroblasts (HDFs). More interestingly, adipogenic differentiation potential of hMSCs sharply declined as they approached the end of their proliferative life span. In this study, altered hMSCs were verified to be senescent by their senescence-associated beta-galactosidase (SA-beta-gal) activity and the increased expression of cell cycle regulating proteins (p16(INK4a), p21(Waf1) and p53). Similar as in HDFs, basal phosphorylation level of ERK was also significantly increased in senescent hMSCs, implying altered signal paths commonly shared by the senescent cells. Insulin, a major component of adipogenesis inducing medium, did not phosphorylate ERK 1/2 more in senescent hMSCs after its addition whereas it did in young cells. In senescent hMSCs, we also found a significant increase of caveolin-1 expression, previously reported as a cause for the attenuated response to growth factors in senescent HDFs. When we overexpressed caveolin-1 in young hMSC, not only insulin signaling but also adipogenic differentiation was significantly suppressed with down-regulated PPARgamma2. These data indicate that loss of adipogenic differentiation potential in senescent hMSC is mediated by the over-expression of caveolin-1.