miR-451对肾小球系膜细胞增殖的抑制作用及其机制

目的探讨微小RNA(microRNA,miRNA)-451对肾小球系膜细胞增殖的抑制作用及其机制。方法在Lipofectamine 2000介导下,将miR-451模拟物(miR-451 mimics)及mimics对照分别转染高糖培养的肾小球系膜细胞,另设高糖未转染组和低糖未转染组,实时荧光RT-PCR法检测各组细胞中miR-451的表达水平;MTT法检测miR-451对小鼠肾小球系膜细胞增殖的影响;Western blot法检测靶蛋白Ywhaz、p-p38 MAPK和p-MKK3的表达水平。结果 miR-451组细胞中miR-451的表达水平较mimics对照组明显升高(P<0.01);miR-451组第2、3、4天的细胞增殖能力明显低于高糖未转染组(P均<0.05),第3、4天明显低于mimics对照组(P均<0.05);与mimics对照组和高糖未转染组比较,miR-451组细胞中Ywhaz、p-p38 MAPK和p-MKK3的表达水平均明显下降(P均<0.05)。结论 miR-451可抑制Ywhaz蛋白的表达,降低p38 MAPK信号途径中p-p38 MAPK和p-MKK3蛋白的表达,从而降低高糖诱导的肾小球系膜的增殖。本实验为研究糖尿病肾病(diabetic nephropathy,DN)的发病机制提供了新的思路。     

小鼠微RNA miR-21真核表达质粒的构建及其在小鼠肾小球系膜细胞中的表达

目的构建小鼠微RNA miR-21真核表达质粒,并在小鼠肾小球系膜细胞中表达。方法人工合成小鼠miR-21基因序列,构建miR-21真核表达质粒pGenesil-miR-21。使用脂质体Lipofectamine2000转染小鼠肾小球系膜细胞后,G418筛选,获得稳定转染克隆,提取总RNA,通过实时荧光定量RT-PCR技术检测miR-21的表达。结果经酶切鉴定和测序证实,合成的miR-21基因序列完全正确,并已成功克隆到真核表达质粒pGenesil-1上。重组真核表达质粒转染小鼠肾小球系膜细胞后,筛选出的阳性克隆可稳定高表达miR-21。结论已成功构建miR-21真核表达质粒,并在小鼠肾小球系膜细胞中高效表达,为进一步探讨miR-21的生物学功能奠定了基础。     

miR-451靶向调控肾小球系膜细胞Ywhaz基因的表达

目的探讨miR-451对肾小球系膜细胞Ywhaz基因表达的靶向调控。方法应用生物信息学技术对miR-451的靶基因进行预测,PCR法扩增靶基因3′UTR全长片段,插入荧光素酶报告载体pmiR-RB-REPORTTMvector中,构建荧光素酶报告质粒pmiR-Ywhaz-3′UTR。将miR-451 mimics和NC mimics分别转染高糖培养条件下的小鼠系膜细胞,将miR-451 inhibitor和NC inhibitor分别转染低糖培养条件下的小鼠系膜细胞,采用Real-time RT-PCR和Westernblot法检测miR-451和Ywhaz的表达水平;将miR-451 mimics和NC mimics分别与pmiR-Ywhaz-3′UTR共转染高糖培养条件下的小鼠系膜细胞,miR-451 inhibitor和NC inhibitor分别与pmiR-Ywhaz-3′UTR共转染低糖培养条件下的小鼠系膜细胞,检测各组细胞荧光素酶活性。结果 Ywhaz基因3′UTR区有11个碱基与miR-451种子序列匹配,其中7个碱基呈高度保守性;荧光素酶报告质粒经测序鉴定构建正确;miR-451在miR-451 mimics组呈高表达,在miR-451 inhibitor组表达降低;miR-451可抑制Ywhaz的蛋白表达;荧光素酶活性检测发现,miR-451可通过与Ywhaz3′UTR的结合,抑制Ywhaz的表达。结论 miR-451可直接靶向糖尿病相关基因Ywhaz,抑制其蛋白表达,为进一步研究miR-451调控早期糖尿病肾病发生发展的机制提供了依据。     

miRNA-21对肺癌A549细胞抑癌基因PTEN表达的调控

目的探讨miRNA-21对肺癌A549细胞抑癌基因PTEN表达的调控作用。方法人工合成miRNA-21序列,插入到质粒pGenesil-1中,构建重组真核表达质粒,并转染至肺癌A549细胞,采用RT-PCR和Western blot分别检测细胞PTEN基因mRNA转录水平和蛋白的表达水平。结果经酶切和测序鉴定,表明重组真核表达质粒构建正确。转染重组真核表达质粒的A549细胞PTEN基因mRNA转录水平与未转染组相比,差异无统计学意义,蛋白表达水平较未转染组明显降低。结论miRNA-21可能主要在翻译水平调控PTEN基因的表达。     

microRNA-143阻遏乳腺癌细胞免疫抑制的作用及其机制

目的探讨microRNA-143(miR-143)阻遏乳腺癌细胞免疫抑制的作用及其分子机制。方法采用MTT法检测乳腺细胞HBL-100和乳腺癌细胞MCF-7、MDA-MB-231、BT549补体依赖的细胞毒性(complement-dependent cytotoxicity,CDC);在脂质体介导下,将miR-143、miR-143对照物(scramble)和miR-143抑制剂(inhibitor)分别转染MCF-7细胞,将miR-143 scramble和miR-143 inhibitor分别转染HBL-100细胞,采用MTT法检测CDC,RT-PCR法检测细胞中补体调节蛋白CD46基因mRNA的转录水平,Western blot法检测CD46蛋白的表达水平。结果乳腺癌细胞MCF-7、MDA-MB-231、BT-549的A570值与正常乳腺细胞HBL-100相比,均明显升高(P<0.01);与miR-143 scramble转染的MCF-7细胞的A570值相比,miR-143转染组的A570值明显下降(P<0.001),与miR-143 scramble转染的HBL-100细胞的A570值相比,miR-143 inhibitor转染的HBL-100细胞的A570值明显上升(P<0.001);与HBL-100细胞相比,CD46蛋白在MCF-7、MDA-MB-231和BT-549细胞中表达均上调,且与抑制CDC的作用呈正相关;在HBL-100细胞中过表达miR-143 inhibitor能上调CD46蛋白的表达水平,而不影响CD46基因mRNA的转录水平;在MCF-7细胞中过表达miR-143能明显抑制CD46蛋白的表达水平。结论 CD46在乳腺癌细胞中的上调导致了癌细胞对CDC的抵抗作用,是产生免疫抑制的机制之一;miR-143通过抑制CD46蛋白的表达水平,使细胞对CDC的作用更为敏感,提高了补体系统对乳腺癌细胞的杀伤作用,降低了其免疫抑制能力。     

miR-628-3p靶向结合STK17B基因对卵巢癌进展的抑制作用

目的 分析miR-628-3p通过靶向丝氨酸/苏氨酸激酶17B(serine/threonine kinase 17B,STK17B)抑制卵巢癌（ovarian cancer,OV）增殖、迁移和侵袭的能力。方法 生物信息学分析miR-628-3p在OV组织中的表达水平及预后。分别将空载NC质粒（miR-NC）、miR-628-3p、miR-628-3p+STK17B转染至人OV细胞SKOV3和HO8910中,RT-qPCR法检测转染细胞中miR-628-3p表达水平;CCK-8法和克隆试验检测各组细胞增殖能力;划痕愈合试验检测各组细胞迁移能力;Transwell侵袭试验检测各组细胞侵袭能力。裸鼠成瘤试验检测瘤体质量及体积变化。Starbase数据库预测miR-628-3p靶基因,双荧光酶素报告试验进行验证。Western blot法测定各组细胞STK17B蛋白表达水平。结果miR-628-3p在OV组织中低表达,且患者无病生存期低。与miR-NC组相比,miR-628-3p组SKOV3和HO8910细胞中miR-628-3p表达均上调（t分别为7.789和7.862,P均<0.0...     

桑叶中1-脱氧野尻霉素的提取和对高糖诱导的肾小球系膜细胞凋亡和炎性因子的影响

目的：对桑叶中1-脱氧野尻霉素的提取条件进行优化后研究其对高糖诱导的肾小球系膜细胞凋亡和炎性因子的影响。方法：建立1-脱氧野尻霉素的定量检测方法，探讨桑叶中1-脱氧野尻霉素的最佳提取条件。培养小鼠肾小球系膜(SV40 MES 13)细胞，并分为四组：正常对照组(PBS)、高糖组(30mmoL/L葡萄糖)和1-脱氧野尻霉素组(2、50μM)，给药结束后采用CCK-8法测定SV40MES13细胞的存活率，ELISA测定炎性因子单核细胞趋化蛋白1(Monocyte chemoattractant protein-1,MCP-1)、肿瘤坏死因子α(Tumor necrosis factor-alpha,TNF-α)和白细胞介素6(Interleukin-6,IL-6)的水平。最后用Western blotting法检测细胞增殖蛋白Cyclin D1和PCNA的表达水平。结果：桑叶中1-脱氧野尻霉素的提取条件最终优化为料液比1:15 g/mL、p H值3.0和提取时间30 min。1-脱氧野尻霉素明显提高SV40 MES 13细胞的存活率，并下调炎性因子IL-6的表达水平，且高剂量的1-脱氧野尻...     

FOXC1蛋白基因shRNA干扰质粒对胃癌SGC-7901细胞增殖的影响

目的探讨FOXC1蛋白基因RNA干扰质粒对胃癌SGC-7901细胞增殖的影响。方法采用RT-PCR及Westernblot法检测SGC-7901细胞和胃黏膜上皮细胞GES-1中FOXC1基因mRNA的转录水平和蛋白的表达水平。构建3个FOXC1基因shRNA真核表达质粒pshRNA-FOXC1a、pshRNA-FOXC1b、pshRNA-FOXC1c,分别转染SGC-7901细胞,并设pGenesil-1空质粒转染组和未转染的细胞对照组,RT-PCR及Western blot法分别检测转染细胞中FOXC1基因mRNA的转录水平和蛋白的表达水平;MTT法检测转染细胞的增殖活力;流式细胞术检测转染细胞的细胞周期。结果 SGC-7901细胞中FOXC1基因mRNA的转录水平及蛋白的表达水平均显著高于GES-1细胞(P<0.05)。pshRNA-FOXC1a组、pshRNA-FOXC1b组和pshRNA-FOXC1c组SGC-7901细胞中FOXC1基因mRNA的转录水平和蛋白的表达水平均显著低于pGenesil-1组和SGC-7901组(P<0.01);细胞增殖抑制率显著高于pGensil-1组(P<0.05)。处于G1、G2期的细胞比例显著高于SGC-7901组(P<0.01),S期细胞比例显著低于SGC-7901组(P<0.01)。结论成功构建了FOXC1蛋白基因shRNA真核表达质粒。FOXC1在胃癌细胞SGC-7901中呈高表达,抑制其表达后,细胞周期被阻滞在G1～G2期,细胞增殖受到抑制。     

miRNA-155对人乳腺癌MCF-7细胞TP53INP1表达及其增殖的影响

目的探讨miRNA-155对人乳腺癌MCF-7细胞TP53INP1表达及其增殖的影响。方法采用LipofectamineTM2000将miRNA-155 mimics(或带荧光无关序列阴性对照FAM-NC)转染雌激素受体(Estrogen receptor,ER)阳性人乳腺癌MCF-7细胞,并设空白对照组;RT-PCR法检测转染后miRNA-155的表达水平;CCK-8法检测miRNA-155对MCF-7细胞增殖能力的影响;流式细胞术检测MCF-7细胞的凋亡率和增殖周期;Western blot法检测TP53INP1、Caspase-3及p21蛋白的表达水平。结果与空白对照组和阴性对照组相比,转染组miRNA-155的表达量明显增高;随着时间的延长,MCF-7细胞增殖活力逐渐增加;G1期细胞明显减少,S和G2期细胞增多,凋亡率明显降低;TP53INP1、Caspase-3激活型及p21蛋白的表达水平均明显降低。结论 miRNA-155能够抑制人乳腺癌MCF-7细胞TP53INP1蛋白的表达,进而抑制肿瘤细胞凋亡、促进细胞增殖,在乳腺癌发生发展中具有重要作用。     

Matrine Activates PTEN to Induce Growth Inhibition and Apoptosis in V600EBRAF Harboring Melanoma Cells

Here, we report a natural chemical Matrine, which exhibits anti-melanoma potential with its PTEN activation mechanism. Matrine effectively inhibited proliferation of several carcinoma cell lines, including melanoma ^V600EBRAF harboring M21 cells. Flow cytometry analysis showed Matrine induced G₀/G₁ cell cycle arrest in M21 cells dose-dependently. Apoptosis in M21 cells induced by Matrine was identified by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis and Annexin-V/FITC staining. Molecular mechanistic study suggested that Matrine upregulated both mRNA level and protein expression level of phosphatase and tensin homolog deleted on chromosome ten (PTEN), leading to inhibition of the PI3K/Akt pathway. Downregulation of phosphor-Akt^ser473 by Matrine activated p21 and Bax, which contributed to G₀/G₁ cell cycle and apoptosis. Besides, Matrine enhanced the PI3K/Akt inhibition effects to inhibit the cell proliferation with PI3K inhibitor, LY2940002. In summary, our findings suggest Matrine is a promising antitumor drug candidate with its possible PTEN activation mechanisms for treating cancer diseases, such as melanomas.     

Chronic and Intermittent Hyperglycemia Modulates Expression of Key Molecules of PI3K/AKT Pathway in Differentiating Human Visceral Adipocytes

Background: Due to its prominence in the regulation of metabolism and inflammation, adipose tissue is a major target to investigate alterations in insulin action. This hormone activates PI3K/AKT pathway which is essential for glucose homeostasis, cell differentiation, and proliferation in insulin-sensitive tissues, like adipose tissue. The aim of this work was to evaluate the impact of chronic and intermittent high glucose on the expression of biomolecules of insulin signaling pathway during the differentiation and maturation of human visceral preadipocytes. Methods: Human visceral preadipocytes (HPA-V) cells were treated with high glucose (30 mM)during the proliferation and/or differentiation and/or maturation stage. The level of mRNA (by Real-Time PCR) and protein (by Elisa tests) expression of IRS1, PI3K, PTEN, AKT2, and GLUT4 was examined after each culture stage. Furthermore, we investigated whether miR-29a-3p, miR-143-3p, miR-152-3p, miR-186-5p, miR-370-3p, and miR-374b-5p may affect the expression of biomolecules of the insulin signaling pathway. Results: Both chronic and intermittent hyperglycemia affects insulin signaling in visceral pre/adipocytes by upregulation of analyzed PI3K/AKT pathway molecules. Both mRNA and protein expression level is more dependent on stage-specific events than the length of the period of high glucose exposure. What is more, miRs expression changes seem to be involved in PI3K/AKT expression regulation in response to hyperglycemic stimulation.     

Caffeic Acid Phenethyl Ester Suppresses Proliferation and Survival of TW2.6 Human Oral Cancer Cells via Inhibition of Akt Signaling

Caffeic acid phenethyl ester (CAPE) is a bioactive component extracted from honeybee hive propolis. Our observations indicated that CAPE treatment suppressed cell proliferation and colony formation of TW2.6 human oral squamous cell carcinoma (OSCC) cells dose-dependently. CAPE treatment decreased G1 phase cell population, increased G2/M phase cell population, and induced apoptosis in TW2.6 cells. Treatment with CAPE decreased protein abundance of Akt, Akt1, Akt2, Akt3, phospho-Akt Ser473, phospho-Akt Thr 308, GSK3β, FOXO1, FOXO3a, phospho-FOXO1 Thr24, phospho-FoxO3a Thr32, NF-κB, phospho-NF-κB Ser536, Rb, phospho-Rb Ser807/811, Skp2, and cyclin D1, but increased cell cycle inhibitor p27^Kip. Overexpression of Akt1 or Akt2 in TW2.6 cells rescued growth inhibition caused by CAPE treatment. Co-treating TW2.6 cells with CAPE and 5-fluorouracil, a commonly used chemotherapeutic drug for oral cancers, exhibited additive cell proliferation inhibition. Our study suggested that administration of CAPE is a potential adjuvant therapy for patients with OSCC oral cancer.     

miR-21 Promotes Human Nucleus Pulposus Cell Proliferation through PTEN/AKT Signaling

The precise role of nucleus pulposus cell proliferation in the pathogenesis of intervertebral disc degeneration remains to be elucidated. Recent findings have revealed that microRNAs, a class of small noncoding RNAs, may regulate cell proliferation in many pathological conditions. Here, we showed that miR-21 was significantly upregulated in degenerative nucleus pulposus tissues when compared with nucleus pulposus tissues that were isolated from patients with idiopathic scoliosis and that miR-10b levels were associated with disc degeneration grade. Moreover, bioinformatics target prediction identified PTEN as a putative target of miR-21. miR-21 inhibited PTEN expression by directly targeting the 3′UTR, and this inhibition was abolished through miR-21 binding site mutations. miR-21 overexpression stimulated cell proliferation and AKT signaling pathway activation, which led to cyclin D1 translation. Additionally, the increase in proliferation and cyclin D1 expression induced by miR-21 overexpression was almost completely blocked by {"type":"entrez-nucleotide","attrs":{"text":"Ly294002","term_id":"1257998346","term_text":"LY294002"}}Ly294002, an AKT inhibitor. Taken together, aberrant miR-21 upregulation in intervertebral disc degeneration could target PTEN, which would contribute to abnormal nucleus pulposus cell proliferation through derepressing the Akt pathway. Our study also underscores the potential of miR-21 and the PTEN/Akt pathway as novel therapeutic targets in intervertebral disc degeneration.     

miR-486-5p and miR-22-3p Enable Megakaryocytic Differentiation of Hematopoietic Stem and Progenitor Cells without Thrombopoietin

Megakaryocytes release submicron size microparticles (MkMPs) in circulation. We have shown that MkMPs target CD34+ hematopoietic stem/progenitor cells (HSPCs) to induce megakaryocytic differentiation, and that small RNAs in MkMPs play an important role in the development of this phenotype. Here, using single-molecule real-time (SMRT) RNA sequencing (RNAseq), we identify the synergetic effect of two microRNAs (miRs), miR-486-5p and miR-22-3p (highly enriched in MkMPs), in driving the Mk differentiation of HSPCs in the absence of thrombopoietin (TPO). Separately, our data suggest that the MkMP-induced Mk differentiation of HSPCs is enabled through JNK and PI3K/Akt/mTOR signaling. The interaction between the two signaling pathways is likely mediated by a direct target of miR-486-5p and a negative regulator of PI3K/Akt signaling, the phosphatase and tensin homologue (PTEN) protein. Our data provide a possible mechanistic explanation of the biological effect of MkMPs in inducing megakaryocytic differentiation of HSPCs, a phenotype of potential physiological significance in stress megakaryopoiesis.     

NLS-RARα基因沉默对HL-60细胞增殖及分化的影响

目的探讨抑制NLS-RARα基因表达对急性早幼粒细胞白血病(Acute promyeolic leukemia,APL)细胞株HL-60增殖及分化的影响。方法将针对NLS-RARα基因的shRNA真核表达质粒(干扰组)和阴性对照质粒(阴性对照组)采用脂质体法转染HL-60细胞,并设未转染组,经G418筛选出稳定转染的细胞,采用MTT法检测细胞的增殖活力;RT-PCR和QRT-PCR法检测细胞中NLS-RARα基因mRNA的转录水平;Western blot法检测细胞中NLS-RARα蛋白的表达水平;流式细胞术检测细胞表面分化抗原CD11b的表达及细胞周期的分布。结果与阴性对照组和未转染组比较,干扰组HL-60细胞的增殖活力、NLS-RARα基因mRNA的转录水平和蛋白的表达水平均明显下降(P<0.05);CD11b的表达明显升高(P<0.05);G1、G2期细胞比例明显增加,S期细胞比例明显减少(P<0.05)。结论抑制NLS-RARα基因的表达可抑制HL-60细胞增殖,促进其分化。本实验为进一步研究APL发生发展的机制及APL的分子诊断和靶向治疗新途径奠定了基础。