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。     

LncRNA TMPO-AS1 up-regulates the expression of HIF-1α and promotes the malignant phenotypes of retinoblastoma cells via sponging miR-199a-5p

BackgroundLong non-coding RNA (lncRNA) TMPO antisense RNA 1 (TMPO-AS1) is reported to be oncogenic in prostate cancer and lung cancer. This study aims to investigate the expression and biological function of it in retinoblastoma (RB), and explore its regulatory role for miR-199a-5p and hypoxia-inducible factor-1α (HIF-1α).MethodsPaired RB samples were collected, and the expression levels of TMPO-AS1, miR-199a-5p and HIF-1α were examined by quantitative real-time polymerase chain reaction (qRT-PCR); TMPO-AS1 overexpressing plasmids and TMPO-AS1 shRNA were transfected into HXO-RB44 and SO-Rb50 cell lines respectively, and then proliferation, migration and invasion of RB cells were detected by CCK-8 assay and Transwell method. qRT-PCR and western blot were used to analyze the regulatory function of TMPO-AS1 on miR-199a-5p and HIF-1α; luciferase reporter gene assay was used to determine the regulatory relationship between miR-199a-5p and TMPO-AS1.ResultsTMPO-AS1 was significantly up-regulated in cancerous tissues of RB samples (relatively expression: 2.97 vs 3.93, p < 0.001), negatively correlated with miR-199a-5p (r=-0.4813, p < 0.01). There was one binding site on TMPO-AS1 for miR-199a-5p. After transfection of TMPO-AS1 shRNAs into RB cells, the proliferation, migration and invasion of cancer cells was significantly inhibited, while TMPO-AS1 had opposite effects; TMPO-AS1 was also demonstrated to regulate the expression of HIF-1α on both mRNA and protein levels via negatively regulating miR-199a-5p.ConclusionTMPO-AS1 is abnormally up-regulated in RB tissues, and it can modulate the proliferation and migration of RB cells. It has the potential to be the “ceRNA” to regulate HIF-1α expression by sponging miR-199a-5p.     

miR-199a-3p targets ETNK1 to promote invasion and migration in gastric cancer cells and is associated with poor prognosis

PurposeTo investigate the prognostic significance of miR-199a-3p and its role in invasion and metastasis in gastric cancer.MethodsmiR-199a-3p expression in 436 formalin-fixed and 39 frozen gastric cancer tissues was investigated by in situ hybridization and RT-PCR, respectively. The role of miR-199a-3p in the migration and invasion of gastric cancer cells was determined in overexpression and inhibitor studies using transwell assays and the SGC-7901, BGC-823 and MGC-803 gastric cancer cells lines. The effect of miR-199a-3p expression on ethanolamine kinase 1 (ETNK1) levels was determined by western botting.ResultsmiR-199a-3p was significantly up-regulated in AGS, SGC-7901, BGC-823 and MGC-803 gastric cancer cells, when compared with GES-1 non-malignant gastric epithelial cells. In situ hybridization studies revealed that human non-tumor gastric mucosa samples were negative for miR-199a-3p expression, while 162 of 436 (37.16%) cases of gastric cancer demonstrated positive expression. miR-199a-3p overexpression was associated with tumor size, Lauren classification, depth of invasion, lymph node and distant metastasis, TNM stage and prognosis. In patients with I, II and III stage tumors, high miR-199a-3p expression was associated with a significantly lower 5-year survival rate. miR-199a-3p overexpression was associated with increased cell migration and invasion. ETNK1 expression was inhibited following miR-199a-3p overexpression in BGC-823 and SGC-7901 cells, and elevated following miR-199a-3p suppression in MGC-803 cells.ConclusionmiR-199a-3p is highly expressed in gastric cancer, and correlates with invasion, metastasis and prognosis. miR-199a-3p regulates the invasion and migration of gastric cancer cells by targeting ETNK1. Consequently, miR-199a-3p may serve as a prognostic indicator in gastric cancer.     

miR-27a-3p靶向HOXA5基因通过Wnt/β-catenin信号通路调控糖尿病患者创面愈合

目的:研究微小RNA-27a-3p(miR-27a-3p)对糖尿病患者创面愈合的影响及作用机制.方法:采用qPCR和Western blot检测糖尿病患者创面愈合组织中miR-27a-3p、同源异型盒基因A5(HOXA5)mRNA和HOXA5蛋白的表达.使用高糖处理人微血管内皮细胞(HMECs),模拟糖尿病HMECs的...     

HSF1基因缺失通过上调microRNA-195a-3p加速压力超负荷下心脏重构

目的:探讨热休克转录因子1(HSF1)调控微小RNA-195a-3p (miR-195a-3p)对心肌微血管内皮细胞血管新生功能的影响,旨在阐明HSF1基因缺失加重压力超负荷下心脏重构的病理分子机制。方法:压力超负荷动物模型采用小鼠主动脉弓缩窄(TAC),辅以心脏超声功能评价。在体实验分组为HSF1基因敲除(HSF1~(-/-))小鼠假手术组、C57BL/6野生型(WT)小鼠假手术组、HSF1~(-/-)小鼠TAC模型组和C57BL/6 WT小鼠TAC组;细胞实验分组为对照组、miR-195a-3p模拟物干预组和阴性对照microRNA(miR-NC)干预组。TAC术后4周,通过病理组织切片检测各组小鼠心肌肥厚(HE染色)和血管新生(CD31染色),小鼠心超检查心脏主要功能指标变化;通过生物信息软件TargetScan 6.2结合萤光素酶(luciferase)报告基因检测,以及Western blot验证,测定miR-195a-3p调控血管新生的下游分子靶点;并用miR-195a-3p诱导微血管内皮细胞,观察其对细胞成管能力的影响。结果:HSF1缺失会导致TAC诱导的小鼠左心室重构加重。芯片筛查结果表明HSF1缺失可促进心脏12种microRNAs表达上调,5种microRNAs在心肌微血管内皮细胞中表达显著升高,其中miR-195a-3p的增高具有统计学显著性。miR-195a-3p过表达可以有效抑制微血管内皮细胞CD31和血管内皮生长因子(VEGF)的表达,阻滞细胞形成管腔样结构。TargetScan 6.2预测miR-195a-3p的靶点为AMP活化蛋白激酶α2(AMPKα2),在微血管内皮细胞用miR-195a-3p模拟物干预可以有效抑制AMPKα2的表达,同时miR-195a-3p模拟物也抑制了CD31和VEGF的表达。结论:HSF1基因缺失导致的miR-195a-3p表达上调是加速压力超负荷下心脏重构的重要诱因,其机制可能是通过抑制AMPKα2介导的血管新生信号通路的激活。     

An involvement of SR-B1 mediated p38 MAPK signaling pathway in serum amyloid A-induced angiogenesis in rheumatoid arthritis

Serum amyloid A (SAA) has been reported high expression in autoimmune diseases, such as rheumatoid arthritis (RA). However, detailed molecular mechanisms induced by SAA in the pathogenesis of RA are still unclear. Herein, we focused on the role of SAA–SR-B1 mediated p38 MAPK signaling pathway in the process of RA angiogenesis. Our results showed that both SAA and SR-B1 predominantly localized to vascular endothelial cells, lining and sublining layers in RA synovium. In a series of in vitro experiments with human umbilical vein endothelial cells (HUVECs), SAA induced the endothelial cells (ECs) proliferation, migration and tube formation. However, blockage of SR-B1 and p38 MAPK inhibited SAA-induced cells proliferation, migration and tube formation. In conclusion, our data showed a possible molecular mechanism for SAA–SR-B1 induced angiogenesis events via p38 MAPK signaling pathway.     

miR-130a-3p 通过调控 PDK1 影响肝癌细胞糖代谢的研究

目的 探讨 miR-130a-3p 通过靶向糖代谢关键酶 PDK1 对肝癌细胞糖代谢以及增殖迁移的影响, 为肝癌的诊断及治疗提供新的方向。 方法 qRT-PCR 技术检测肝癌的临床组织和细胞中 miR-130a-3p 的表 达, 克隆形成、 CCK-8、 Transwell 和细胞划痕实验检测细胞的增殖和迁移; Western 印迹检测相关蛋白的表 达; 乳酸检测试剂盒, ATP 检测试剂盒和 PDH 活性检测试剂盒分别检测细胞中乳酸的生成、 ATP 的生成和 PDH 的活性; 双荧光素酶报告基因实验验证 miR-130a-3p 与 PDK1 3′UTR 靶向结合。 结果 在肝癌组织和 细胞中 miR-130a-3p 呈低表达, 并与患者肿瘤组织的大小和 TNM 分期有关; 过表达 miR-130a-3p 能够增强 肝癌细胞中 PDH 活性, 抑制乳酸和 ATP 的生成, 从而抑制肝癌细胞的增殖和迁移; miR-130a-3p 可以靶向 调控 PDK1; 抑制 PDK1 的表达, 能够逆转 miR-130a-3p 过表达对细胞增殖和迁移能力的增强, 此外对 PDH 活 性、 乳酸和 ATP 的影响也被逆转。 结论 miR-130a-3p 通过靶向调控 PDK1 影响肝癌细胞糖酵解及恶性进展。     

下调miR-199a-5p对阿霉素诱导的心肌细胞凋亡的影响和机制研究

目的:探讨下调miR-199a-5p对阿霉素诱导的心肌细胞凋亡的影响和机制。方法:将心肌细胞H9C2分成Control组(常规培养的对照细胞)、DOX组(经含1μM阿霉素的细胞培养液培养)、DOX+Anti-miR-NC组(转染inhibitor control,经含1μM阿霉素的细胞培养液培养)和DOX+Anti-miR-199a-5p组(转染miR-199a-5p inhibitor,经含1μM阿霉素的细胞培养液培养)、DOX+Anti-miR-199a-5p+DKK1组(转染miR-199a-5p inhibitor,经含1μM阿霉素和20ng/ml的Wnt/β-catenin信号抑制剂DKK1的细胞培养液培养)。各组细胞处理24h以后,Realtime PCR测定miR-199a-5p表达,CCK-8测定细胞增殖,流式细胞术测定细胞凋亡,Western blot测定C-Caspase-3、β-catenin、c-Myc蛋白表达。结果:与Control组比较,DOX组细胞中miR-199a-5p水平升高,细胞增殖活性下降,细胞凋亡和C-Caspase-3蛋白表达水平升高,β-catenin、c-Myc蛋白表达水平降低(P均<0.01)。与DOX+Anti-miR-NC组比较,DOX+Anti-miR-199a-5p组细胞中miR-199a-5p水平降低,细胞增殖活性升高,细胞凋亡水平和C-Caspase-3蛋白表达水平降低,β-catenin、c-Myc蛋白表达水平升高(P均<0.01)。与DOX+Anti-miR-199a-5p组相比,DOX+Anti-miR-199a-5p+DKK1组心肌细胞存活率降低,细胞凋亡率升高,细胞中C-Caspase-3蛋白表达水平升高,β-catenin、c-Myc蛋白表达水平降低(P均<0.01)。结论:下调miR-199a-5p通过激活Wnt/β-catenin信号抑制阿霉素诱导的心肌细胞凋亡。     

Resveratrol protects BV2 mouse microglial cells against LPS-induced inflammatory injury by altering the miR-146a-5p/TRAF6/NF-κB axis

Abstract

Objective: To investigate the role of miR-146a-5p in the effects of resveratrol (RSV) on inflammatory response in BV2 mouse microglial cells.

Materials and methods: BV2 cells were pretreated by RSV and stimulated with lipopolysaccharide (LPS). Cell Viability was checked using a MTT assay. Real-Time PCR was performed to detect the levels of pro-inflammatory cytokines (tumor necrosisfactor-α－TNF-α, interleukin-1β－IL-1β and interleukin-6 － IL-6) and miR-146a-5p expression. Western blot was used to analyze the protein expression of TNF receptor associated factor 6 (TRAF6) and phospho-nuclear factor kappa B (pNF-κB). Gain-of-function and loss-of-function analysis of miR-146a-5p was performed using transfection of miR-146a-5p mimic and miR-146a-5p inhibitor, respectively.

Results: Pretreatment with RSV significantly and dose dependently inhibited LPS-induced production of TNF-α, IL-1β and IL-6 in BV2 cells. MiR-146a-5p was significantly upregulated after LPS treatment, and further increased in RSV and LPS-co-treated cells. MiR-146a-5p overexpression via miR-146a-5p mimic transfection downregulated the mRNA level of TNF-α, IL-1β and IL-6, as well as abrogated the protein expression of TRAF6 and pNF-κB in BV2 cells exposed to LPS. More importantly, the reducion of TNF-α, IL-1β and IL-6 level by RSV were reversed by miR-146a-5p silence via miR-146a-5p inhibitor transfection. Furthermore, silencing miR-146a-5p attenuated the inhibitory effect of RSV on the TRAF6/NF-κB pathway which was activated after induction with LPS. Conclusions: RSV can suppress LPS-induced inflammatory injury via modulating the miR-146a-5p/TRAF6/NF-κB axis in BV2 mouse microglial cells.     

miR-18a对人主动脉内皮细胞血管生成能力的影响

目的: 观察miR-18a对人主动脉内皮细胞血管生成能力的影响。方法: 分别将10 nmol/L miR-18a mimics和20 nmol/L miR-18a inhibitor转染至人主动脉内皮细胞,qRT-PCR法检测miR-18a表达情况并观察内皮细胞的迁移、黏附和管腔形成能力。结果: 转染48 h后,miR-18a mimics组miR-18a表达为对照组的608倍(P<0.05);miR-18a inhibitor组miR-18a表达降低至 对照组的31%(P<0.05)。与对照组相比,miR-18a mimics转染后迁移至Transwell小室下层的内皮细胞数目和毛细血管管腔形成数目分别减少60%和52%(P<0.01);而miR-18a inhibitor转染后分别增加100%(P<0.05)和84%(P<0.01),细胞黏附能力增加43%(P<0.05)。结论: miR-18a的表达水平与人主动脉内皮细胞的血管生成能力相关,可能成为血管性疾病治疗的分子靶点。     

miR-199a-3p 通过靶向 CABLES-1 调控流体剪切力介导的成骨细胞增殖

目的 探讨miR-199a-3p在流体剪切力(fluid shear stress, FSS)诱导成骨细胞增殖中的作用及其可能的分子机制。方法 对成骨细胞MC3T3-E1加载1.2 Pa FSS,时间分别为0、15、30、45、60、75、90 min。使用miR-199a-3p模拟物或miR-199a-3p抑制物转染MC3T3-E1细胞。使用将过表达的miR-199a-3p以及其阴性对照分别转染MC3T3-E1细胞,并以1.2 Pa FSS处理45 min。将pcDNA NC、pcDNA-CABLES-1、si RNA NC、si RNA CABLES-1转染至MC3T3-E1细胞中。分别共转染pc DNA-CABLES-1与miR-199a-3p mimic以及si RNA-CABLES-1与miR-199a-3p inhibitor。CCK-8实验检测细胞活性;RT-qPCR检测CABLES-1、 miR-199a-3p、CDK 6、Cyclin D1、PCNA表达水平;荧光素酶报告实验检测CABLES-1和miR-199a-3p的靶向关系。免疫荧光检测CABLES-1蛋白表达。...     

miR-92a-3p promotes ox-LDL induced-apoptosis in HUVECs via targeting SIRT6 and activating MAPK signaling pathway

Atherosclerosis could be induced by multiple factors, including hypertension, hyperlipidemia, and smoking, and its pathogenesis has not been fully elucidated. MicroRNAs have been shown to possess great anti-atherosclerotic potential, but the precise function of miR-92a-3p in atherosclerosis and its potential molecular mechanism have not been well clarified. Flow cytometry assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazol-3-ium bromide (MTT) assay were performed to evaluate effects of oxidized low-density lipoprotein (ox-LDL) on proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs), respectively. Malondialdehyde and superoxide dismutase levels in cell lysate were assessed with biochemical kits. The expression levels of miR-92a-3p and Sirtuin6 (SIRT6) in HUVECs exposed to ox-LDL were estimated by real-time quantitative polymerase chain reaction (RT-qPCR). In addition, the protein levels of SIRT6, c-Jun N-terminal kinase (JNK), phosphorylation JNK (p-JNK), p38 mitogen activated protein kinase (p38 MAPK), and phosphorylation p38 MAPK (p-p38 MAPK) were measured by western blot assays. The relationship between miR-92a-3p and SIRT6 was confirmed by dual-luciferase reporter assay. Ox-LDL induced apoptosis and oxidative stress in HUVECs in concentration- and time-dependent manners. Conversely, miR-92a-3p silencing inhibited apoptosis and SIRT6 expression in HUVECs. The overexpression of miR-92a-3p enhanced apoptosis and phosphorylation levels of JNK and p38 MAPK as well as inhibited proliferation in ox-LDL-induced HUVECs. In addition, SIRT6 was a target of miR-92a-3p. miR-92a-3p negatively regulated SIRT6 expression in ox-LDL-induced HUVECs to activate MAPK signaling pathway in vitro. In summary, miR-92a-3p promoted HUVECs apoptosis and suppressed proliferation in ox-LDL-induced HUVECs by targeting SIRT6 expression and activating MAPK signaling pathway.     

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.     

HB-EGF stimulates eNOS expression and nitric oxide production and promotes eNOS dependent angiogenesis

Heparin-binding EGF-like growth factor (HB-EGF) is a member of the epidermal growth factor (EGF) family of ligands that is expressed by many cell types including endothelial cells. We have previously shown that HB-EGF stimulates angiogenesis in vitro in human umbilical vein endothelial cells (HUVEC). Nitric oxide (NO) derived from endothelial nitric oxide synthase (eNOS) is an important regulator of angiogenesis. However, the role of HB-EGF in regulation of eNOS has not yet been investigated. Whether HB-EGF-induced endothelial cell migration and vascular network formation are mediated via production of NO from eNOS is also unknown. To address these questions, we stimulated HUVEC with HB-EGF and evaluated the expression of eNOS at the mRNA and protein levels. HB-EGF significantly upregulated expression of eNOS mRNA, stimulated eNOS protein production, and increased NO release from HUVEC. HB-EGF phosphorylated eNOS in a phosphatidylinositol 3-kinase (PI3K) dependent fashion, and stimulated in vitro angiogenesis. eNOS siRNA inhibited HB-EGF-stimulated HUVEC migration in a scratch assay. NG-nitro-L-arginine-methyl-ester (L-NAME) and L-N5-(1-lminoethyl)ornithine,dihydochloride (L-NIO) (specific inhibitors of eNOS) also abolished HB-EGF-induced HUVEC migration and angiogenesis. More importantly, we found that HB-EGF also promotes angiogenesis in vivo in the Marigel plug assay. Lastly, inhibition of the p38 MAPK pathway enhanced HB-EGF-induced EC migration and angiogenesis. We conclude that HB-EGF, through its interaction with EGF receptors (EGFR), stimulates eNOS activation and NO production via a PI3K-dependent pathway. Thus, activation of eNOS appears to be one of the key signaling pathways necessary for HB-EGF mediated angiogenesis. These novel findings highlight an important role for HB-EGF as a regulator of endothelial cell function.     

高血压病血瘀证相关miRNA的筛选

目的:筛选与高血压病血瘀证相关微小RNA(microRNA,miRNA),从基因组学探索高血压病血瘀证的发病机制。方法:运用高血压病气虚血瘀证、气滞血瘀证、寒凝血瘀证、热结血瘀证、非血瘀证患者和健康人的血清干预人脐静脉血管内皮细胞CRL-1730,建立高血压病血瘀证血管内皮细胞损伤模型;提取各组总RNA,采用Solexa高通量测序法和数字基因表达谱测序原理对各组样本进行测序分析,筛选各组间的差异表达miRNA和mRNA,使用靶基因miRWalk预测软件对2者进行相关性的整合,筛选与血瘀证相关miRNA,qRT-PCR定量分析验证miRNA的表达。结果:整合气虚血瘀组与非血瘀组、气滞血瘀组与非血瘀组、寒凝血瘀组与非血瘀组、热结血瘀组与非血瘀组相关数据后,在高表达的基因群中发现SAT1-Hsa-miR-199a-5p和ATF4-Hsa-miR-1283;qRT-PCR定量检测Hsa-miR-199a-5p和Hsa-miR-1283在高血压病血瘀证组和非血瘀证组中的上调与下调趋势与基因测序结果一致。结论:Hsa-miR-199a-5p和Hsa-miR-1283可能是高血压病血瘀证形成的特异性相关miRNA。     

miR-15a-5p抑制人肝癌SMMC-7721细胞增殖与迁移

目的:观察高表达的miR-15a-5p对人肝细胞癌SMMC-7721细胞增殖和迁移能力的影响。方法:化学合成加入EcoRⅠ和HindⅢ酶切位点的miR-15a-5p寡聚核苷酸,并进行测序确认;利用pcDNA6.2-GW/EmGFP质粒构建miR-15a-5p真核表达载体,瞬时转染SMMC-7721细胞,实时荧光定量PCR检测miR-15a-5p的表达;CCK-8法和台盼蓝染色活细胞计数检测SMMC-7721细胞的增殖能力,划痕实验检测细胞迁移能力的变化。结果:设计的miR-15a-5p序列与寡核苷酸测序结果匹配达100%;真核表达质粒瞬转后人肝癌SMMC-7721细胞miR-15a-5p的表达量与对照组相比显著增加(P0.05);miR-15a-5p高表达SMMC-7721细胞的增殖能力与对照组相比均显著下降(P0.05);miR-15a-5p高表达组细胞迁移速度低于对照组。结论:高表达的miR-15a-5p可抑制人肝癌SMMC-7721细胞的增殖和迁移能力。     

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.     

miR-486-5p通过抑制端粒酶活性促进人骨髓间充质干细胞衰老

目的:研究年龄相关microRNA-486-5p(miR-486-5p)对人骨髓间充质干细胞(h MSCs)衰老的调控作用。方法:通过microRNA芯片和real-time PCR检测供体年龄对h MSCs中miR-486-5p表达的影响;通过转染miR-486-5p模拟物或抑制物,过表达miR-486-5p或抑制其表达;用β-半乳糖苷酶染色检测miR-486-5p对h MSCs衰老的影响;通过siRNA研究沉默信息调节因子1(SIRT1)对h MSCs端粒酶逆转录酶(TERT)、端粒酶活性及衰老的影响。结果:随供体年龄增加,h MSCs中miR-486-5p的表达增加。过表达miR-486-5p可促进h MSCs衰老。相反,抑制miR-486-5p的表达可减少h MSCs的衰老。SIRT1及TERT随供体年龄增加而表达下降,直接抑制SIRT1的表达可减少TERT表达,抑制端粒酶活性,促进细胞衰老。同时抑制miR-486-5p和SIRT1的表达,使miR-486-5p失去对h MSCs端粒酶活性及衰老的调控作用。结论:miR-486-5p通过抑制SIRT1,减少h MSCs端粒酶活性,促进h MSCs衰老。