Stable ^(85)Rb micro vapour cells:fabrication based on anodic bonding and application in chip-scale atomic clocks

We describe the microfabrication of ^85Rb vapour cells using a glass-silicon anodic bonding technique and in situ chemical reaction between rubidium chloride and barium azide to produce Rb. Under controlled conditions, the pure metallic Rb drops and buffer gases were obtained in the cells with a few mm^3 internal volumes during the cell sealing process. At an ambient temperature of 90 ℃ the optical absorption resonance of ^85Rb D1 transition with proper broadening and the corresponding coherent population trapping （CPT） resonance, with a signal contrast of 1.5% and linewidth of about 1.7 kHz, have been detected. The sealing quality and the stability of the cells have also been demonstrated experimentally by using the helium leaking detection and the after-9-month optoelectronics measurement which shows a similar CPT signal as its original status. In addition, the physics package of chip-scale atomic clock （CSAC） based on the cell was realized. The measured frequency stability of the physics package can reach to 2.1 × 10^-10 at one second when the cell was heated to 100 ℃ which proved that the cell has the quality to be used in portable and battery-operated devices.

Design and Performance Analysis of Micro Proton Exchange Membrane Fuel Cells

This study describes a novel micro proton exchange membrane fuel cell(PEMFC)(active area,2.5 cm2).The flow field plate is manufactured by applying micro-electromechanical systems(MEMS) technology to silicon substrates to etch flow channels without a gold-coating.Therefore,this investigation used MEMS technology for fabrication of a flow field plate and presents a novel fabrication procedure.Various operating parameters,such as fuel temperature and fuel stoichiometric flow rate,are tested to optimize micro PEMFC performance.A single micro PEMFC using MEMS technology reveals the ideal performance of the proposed fuel cell.The optimal power density approaches 232.75 mW·cm-1 when the fuel cell is operated at ambient condition with humidified,heated fuel.

Expression of circulating microRNA-20a and let-7a in esophageal squamous cell carcinoma

AIM: To investigate the expressions of micro RNA-20a(mi R-20a) and let-7a in esophageal squamous cell carcinoma(ESCC) and their diagnostic value. METHODS: Seventy patients with ESCC and 40 healthy subjects were enrolled to investigate the expression of mi R-20 a and let-7a using quantitative real-time PCR. The expression of mi R-20 a and let-7a was compared between ESCC patients and healthy subjects. The plasma levels of mi R-20 a and let-7a in relation to patient clinicopathologic parameters, the receiver operating characteristic(ROC) curve, and the sensitivity and specificity of mi R-20 a and let-7a in ESCC diagnosis were analyzed.RESULTS: Plasma levels of mi R-20 a were significantly higher in ESCC patients than in healthy controls, and plasma levels of let-7 were lower in ESCC patients than in healthy controls(both P < 0.05). The area under the ROC curve of mi R-20 a was 0.767(95%CI: 0.677-0.857; P < 0.001), when the cut-off value was set at 4.77, the sensitivity and specificity were 64.3% and 75.0%, respectively. The area under the ROC curve of let-7a was 0.829(95%CI: 0.754-0.904; P < 0.001), when the cut-off value was set at 6.22, the sensitivity and specificity were 74.3% and 85.0%, respectively. Thus, the sensitivity and specificity of let-7a were higher than those of mi R-20 a. The median relative plasma expression of let-7a in clinical stage Ⅲ/Ⅳ(0.24) was lower than that in stage Ⅰ/Ⅱ(0.42), while the expression of mi R-20 a according to stage was not statistically different. The expressions of mi R-20 a and let-7a were not related to gender, age, tumor diameter, tumor grade, or pathologic stage.CONCLUSION: Plasma mi R-20 a and let-7a levels are significantly altered in patients with ESCC and can be used as potential biomarkers in the diagnosis of ESCC.

MicroRNA-15a-cell division cycle 42 signaling pathway in pathogenesis of pediatric inflammatory bowel disease

AIM To determine whether cell division cycle(Cdc)42 is regulated by microRNA(miR)-15 a in the development of pediatric inflammatory bowel disease(IBD).METHODS We cultured 293 T cells, used plasmids and performed dual-luciferase assay to determine whether Cdc42 is a miR-15 a target gene. We cultured Caco-2 cells, and stimulated them with tumor necrosis factor(TNF)-α. We then employed lentiviruses to alter the expression of miR-15 a and Cdc42. We performed quantitative reverse transcription polymerase chain reaction(qRTPCR) and immunofluorescence to determine whether Cdc42 is regulated by miR-15 a in Caco-2 cells. Finally, we collected ileocecal tissue by endoscopy from patients and performed qRT-PCR to examine the expression of miR-15 a and Cdc42 in pediatric IBD patients.RESULTS Target Scan and dual-luciferase assay revealed thatCdc42 was a miR-15 a target gene. MiR-15 a expression increased(P = 0.0038) and Cdc42 expression decreased(P = 0.0013) in cells stimulated with TNF-α, and the expression of the epithelial junction proteins zona occludens(ZO)-1(P < 0.05) and E-cadherin(P < 0.001) decreased. Cdc42 levels decreased in miR-15 a-mimic cells(P < 0.001) and increased in miR-15 a inhibitor cells(P < 0.05). ZO-1 and E-cadherin decreased in mi R-15 a-mimic cells(P < 0.001) but not in the miR-15 a inhibitor + TNF-α cells. In Lv-Cdc42 + TNF-α cells, ZO-1 and E-cadherin expression increased compared to the Lv-Cdc42-NC + TNF-α(P < 0.05) or miR-15 a-mimic cells(P < 0.05). Fifty-four pediatric IBD patients were included in this study, 21 in the control group, 19 in the Crohn's disease(CD) active(AC) group, seven in the CD remission(RE) group, and seven in the ulcerative colitis(UC) group. MiR-15 a increased and Cdc42 decreased in the CD AC group compared to the control group(P < 0.05). miR-15 a decreased and Cdc42 increased in the CD RE group compared to the CD AC group(P < 0.05). miR-15 a was positively correlated with the Pediatric Crohn's disease Activity Index(PCDAI)(P = 0.006), while Cdc42 was negatively correlated with PCDAI(P = 0.0008). Finally, miR-15 a expression negatively correlated with Cdc42 in pediatric IBD patients(P = 0.0045).CONCLUSION Mi R-15 a negatively regulates epithelial junctions through Cdc42 in Caco-2 cells and pediatric IBD patients.

Micro RNA-1290 promotes esophageal squamous cell carcinoma cell proliferation and metastasis

AIM:To investigate the biological role of mi R-1290 in esophageal squamous cell carcinoma(ESCC) progression and invasion and the underlying mechanism.METHODS:Quantitative real-time polymerase chain reaction(q RT-PCR) was performed to evaluate mi R-1290 expression in ESCC tissue samples.The roles of mi R-1290 in cell proliferation,migration and invasion were identified using mi R-1290 mimic-transfected cells.In addition,the regulatory effect of mi R-1290 on suppressor of cancer cell invasion(SCAI) was evaluated using q RT-PCR,Western blot analysis and a dual luciferase reporter assay.RESULTS:mi R-1290 was significantly upregulated in ESCC tissue samples compared with normal adjacent tissues(9.213 ± 1.150 vs 1.000 ± 0.0),(P < 0.01).Upregulation of mi R-1290 was associated with tumor differentiation(P = 0.021),N classification(P = 0.006) and tumor-node-metastasis stage(P = 0.021) in ESCC patients.Moreover,ectopic mi R-1290 expression potently promoted ESCC cell growth(P < 0.01),migration(P < 0.01) and invasion(P < 0.01) in vitro.mi R-1290 overexpression in ESCC cell lines decreased SCAI expression at the translational level and reduced SCAI-driven luciferase-reporter activity(P < 0.01).CONCLUSION:Our findings suggested that mi R-1290 may play an oncogenic role in cellular processes of ESCC.

Lugol's iodine增强Micro-CT成像评估口腔鳞状细胞癌切缘状态的研究

目的:本研究拟使用Lugol's iodine增强Micro-CT成像三维评估口腔鳞状细胞癌(oral squamous cell carcinoma,OSCC)切缘状态。方法:本研究共收集68例人OSCC组织样本,所有样本经3%Lugol's iodine染色12 h后行Micro-CT扫描(层厚为50μm)。随后将经Lugol's iodine染色后的样品行常规苏木精-伊红(hematoxylin-eosin,HE)染色切片(厚度为4μm),制作数字化病理切片。分别测量影像图像和病理图像的黏膜切缘(mucosal margin,MM)和深部切缘(deep margin,DM)。结果:Lugol's iodine增强Micro-CT成像可以在三维空间中清晰区分肿瘤边界,且Micro-CT成像相较于二维病理切片,可以更准确地测量MM和DM,发现阳性切缘及临界切缘。结论:Lugol's iodine增强Micro-CT成像可以全面评估OSCC切缘,提供更全面、更清晰的肿瘤边缘信息,指导临床治疗方案选择和预后评估。

The Flow Behavior of Red Blood Cell Reduced Deformability in Microchannel

Blood cells are mainly(~99%)comprised of red blood cells.The most remarkable properties of are their high deformability,which allow they flow through microcapillaries of diameter even smaller than their size.The RBC’s remarkable mechanical properties originate from the unique architecture of its membrane.To study the mechanism of RBC’s deformability,a commonly adopted approach is to localize the cytoskeleton protein by immunofluorescence,followed by exploring the changes of cytoskeleton protein during cell deformation.During this process,the fixed treatment of RBC using GA and PFA is of great importance.However,RBC’s deformability is reduced by the fixation process and skeletal protein of membrane is changed accordingly.The flow behavior of red RBCs through the microchannel also changed.Given the difficulty of observing RBC flow in vivo,in vitro simulation by virtue of microfluidic devices provides a feasible alternative.An important physiological phenomenon of the blood flow is the formation of cell free layer(CFL),with RBCs show a tendency to concentrate towards the central axis of the pipeline and move faster than the plasma layer.However,this phenomena is weaken if the stiffness of the membrane increase,which occurs in some disease,such as hereditary spherocytosis and hereditary elliptocytosis.To study the effects of GA and PFA fix treatment on RBC deformability,a microfluidic platform is employed to measuring the CFL and flow velocity of blood flow in this work.The PDMS micro flow channel used is 100 micrometers in width and 50 micrometers in deep.The RBC suspension is fed into the flow channel by the injection pump(NE-1000.USA),and the experiments are observed and recorded by the inverted microscope(IX70,Olympus,Japan)and high-speed camera(Memrecam GX-1,NAC,Japan)system.Three GA concentrations,i.e.,0.000 5,0.000 75,and 0.001 wt.%were used.Meanwhile,the effect of PFA at a concentration of 2wt.%work with GA was also investigated.Images of the flowing RBCs are processed mainly based on Memrecam GXLink.The results show that,the diameter of the RBC be treated is bigger and the shape of the RBC is became more flat after treated.Some of RBCs lost their biconcave structure.When the RBC suspension with 5%Hct flow in the microchannel,the CFL thickness decrease after being treated.And with concentrations of GA increase,the CFL thickness become thinner.The CFL thickness decrease significantly when GA and 2 wt.%PFA work combined.The velocity of RBCs decreases after treated with the GA or/and 2wt.%PFA.GA is known to relieve the dissolution of red blood cells during fluorescence labeling.On the other hand,the crosslinking of the aldehyde group(-cho)of GA with the amino group(-nh2)of RBC membrane protein will change the conformation of the membrane protein and its visco-elastic properties in turn.Then,the transparent fluidity orrheology characteristics of RBC is altered.Since GA and PFA are commonly used to immobilize red blood cells and keep the fluorescence constant,and PFA works similarly as GA,as a result,the variation of membrane protein conformation is intensified,and the membrane becomes stiffer.

In vitro study of micro-dystrophin gene-modified mesenchymal stem cells

BACKGROUND： Studies have shown that the transplantation of mesenchymal stem cells （MSCs） improves dystrophin expression in muscle cell membrane of mdx mice and plays a role in ameliorating sport injuries to the myocyte. In addition, dystrophin gene plasmid injection exhibits therapeutic effect in mdx mice. However, these two methods exhibit shortcomings, such as low rate of post-transplantation expression. Therefore, the present study determined the combinatorial effects of these two methods. OBJECTIVE： To transfect and observe effects of pSL139 plasmid carrying the micro-dystrophin gene into MSCs, as well as in vitro micro-dystrophin gene expression in transfected MSCs. DESIGN, TIME AND SETTING： A comparative, molecular biology study was performed at the Laboratory of Tissue Engineering, West China Medical Center, Sichuan University from March 2007 to February 2008. MATERIALS： The pSL139 plasmid was cloned and provided by the Department of Neurology, Washington University, USA. Lipofectamine 2000 was purchased from Invitrogen, USA. Mouse anti-human dystrophin N-based terminal monoclonal antibody was purchased from Chemicon, USA. METHODS： Differential velocity adherent technique and density gradient centrifugation were combined to separate and culture MSCs from C57/BL10 mice. The cells were induced to trans-differentiate into osteoblasts. Subsequently, the Lipofectamine 2000 method was used to mediate transfection of plasmid pSL139 into third generation MSCs. MAIN OUTCOME MEASURES： Semi-quantitative reverse transcription polymerase-chain reaction and immunofluorescence were respectively employed to detect micro-dystrophin mRNA and protein expressions in MSCs. RESULTS： At 48 hours after MSC transfection with plasmid pSL139, a 379-kb target band was observed by agarose gel electrophoresis. Immunofluorescence revealed micro-dystrophin expression up to 45%-55%. CONCLUSION： Micro-dystrophin mRNA and protein were highly expressed in pSL139-transfected MSCs, which provided a method for efficient expression of dystrophin.

Meiotic chromosome preparation techniques of pollen mother cells for laser micro-dissection in Populus spp.

In order to isolate meiotic chromosomes of Populus species meiotic chromosome preparation techniques of pollen mother cells for laser micro-dissection were studied. Pollen mother cells at diakinesis ofPopulus canadensis Moench were used as samples. Two methods were used to prepare meiotic chromosomes： in the first, cell suspensions were dropped on polyethylene-naphthalate or polyester membrane slides which had just been incubated at -20~C; in the second method, cell suspensions were also dropped on polyethylene-naphthalate or polyester membrane slides, but spread with the aid of high temperatures. The cells did not completely spread by the first method and chromosomes at diakinesis could not be individually distinguished. In contrast, well-spread diakinesis chromosomes were obtained by the second method, where chromosomes, connected with their nucleolus, were successfully isolated with the laser micro-dissection system. As well, we discuss the prospect of applications of laser micro-dissection in cytogeneties and molecular genetics in Populus species.

Mineralized and Osteoid Tissue from Dental Pulp Stem Cells on Micro-arc Oxidation Titanium in vitro

The presence of insufficient bone volume affects the implant healing and success.The aim of this study was to evaluate osteogenic capacity of dental pulp stem cells(DPSCs) on micro-arc oxidation(MAO) titanium surface.DPSCs were challenged at MAO and smooth titanium surface separately for different durations,and the bone marrow mesenchymal stem cells(BMSCs) served as the positive controls.The osteogenic capacity of DPSCs on MAO titanium surface was assessed by using scanning electron microscopy,energy dispersive spectroscopy,biochemical tests and real-time quantitative PCR.Data showed that DPSCs differentiated into osteoblasts and expressed bone morphogenetic genes on MAO titanium surface.The results of this study revealed that DPSCs had good potential to generate mineralized tissue on MAO titanium plates.The differential potential of DPSCs may be regulated by MAO titanium surface.The osteogenesis potential of DPSCs on the MAO titanium was similar with BMSCs.

Glucocorticoid receptor regulates expression of microRNA-22 and downstream signaling pathway in apoptosis of pancreatic acinar cells

AIM To elucidate the underlying mechanism that microRNA-22(miR-22) promotes the apoptosis of rat pancreatic acinar cells(AR42 J) and the elements that regulate the expression of miR-22.METHODS One hundred nanomoles per liter of caerulein(Cae)was administrated to induce the apoptosis of AR42 J cells and the apoptosis rate was detected by flow cytometry analysis. An amylase assay kit was used to measure the amylase expression level in the supernatant. Quantitative real-time PCR(qRT-PCR)was adopted to measure miR-22 expression. We used online tools to predict the potential transcription promoter of miR-22 and the binding sites, which was further identified by using luciferase reporter analysis,chromatin immunoprecipitation(ChIP) and ChIPqP CR assays. Then, a mimic of miR-22, Nr3 c1 plasmid encoding the glucocorticoid receptor(GR), and siNr3 c1 were used to transfect AR42 J cells, respectively.The mRNA expression of miR-22, Nr3 c1, and Erb-b2 receptor tyrosine kinase 3(ErbB3) was confirmed by qRT-PCR and the apoptosis rate of AR42 J cells was detected by flow cytometry analysis. Western blot was used to detect the expression of ErbB3, GR, PI3 k, PI3 kp85α, Akt, p-Akt, Bad, Bax, Bcl-xl, Bcl-2, and cleaved caspase3.RESULTS After inducing apoptosis of AR42 J cells in vitro, the expression of miR-22 was significantly increased by2.20 ± 0.26 and 4.19 ± 0.54 times, respectively, at3 h and 6 h in comparison with the control group.As revealed by qRT-PCR assay, the expression of miR-22 was 78.25 ± 6.61 times higher in the miR-22 mimic group relative to the miRNA control group,accompanied with an obviously increased acinar cell apoptosis rate(32.53 ± 1.15 vs 18.07 ± 0.89, P =0.0006). The upregulation of miR-22 could suppress its target gene, ErbB3, and the phosphorylation of PI3 k and Akt. Furthermore, we predicted the potential transcription promoter of miR-22 and the binding sites using online tools. Luciferase reporter analysis and sitedirected mutagenesis indicated that the binding site(GACAGCCATGTACA) of the GR, which is encoded by the Nr3 c1 gene. Downregulation of the expression of GR could upregulate the expression of miR-22, which further promoted the apoptosis of AR42 J cells.CONCLUSION GR transcriptionally represses the expression of miR-22,which further promotes the apoptosis of pancreatic acinar cells by downregulating the downstream signaling pathway.

Micro-RNAs Regulate Metabolic Syndrome-induced Senescence in Adipose Tissue-derived Mesenchymal Stem Cells of through P16/MAPK Pathway

Background Mesenchymal stem cells(MSC)constitute an important repair system,but may be impaired by exposure to cardiovascular risk factors.Consequently,adipose tissue-derived MSCs from pigs with the metabolic syndrome(Met S)show decreased vitality.A growing number of micro RNAs(mi RNAs)are recognized as key modulators of senescence,but their role in regulating senescence in MSC in Mets is unclear.We tested the hypothesis that Met S upregulates in MSC expression of mi RNAs that can serve as post-transcriptional regulators of senescence-associated(SA)genes.Methods MSCs were collected from swine abdominal adipose tissue after 16 weeks of Lean or Obese diet(n=6 each).Next-generation mi RNA sequencing(mi RNA-seq)was performed to identify mi RNAs up-or down-regulated in Met S-MSC compare to Lean-MSCs.Functional pathway analysis of SA genes targeted by mi RNAs was performed using gene ontology analysis.MSC senescence was evaluated by p16 and p21 immunoreactivity,H2AX protein expression,and SA-beta-Galactosidase activity.In addition,gene expression of p16,p21,MAPK3,and MAPK14 was studied after inhibition of SA-mi R-27b.Results Senescence biomarkers were significantly elevated in Met S MSC.We found the 7 upregulated mi RNAs,including mi R-27b,and 3 downregulated mi RNAs in Met S-MSCs,which regulate 35 SA genes,particularly MAPK signaling.Inhibition of mi R-27b in cultured MSC downregulated p16 and MARP3 genes.Conclusions Met S modulate MSC expression of SA-mi RNAs that may play the role in modulating their senescence,and the p16 pathway in Met S-MSCs senescence is the primary pathway.

The establishment of a stable PC-3 cell line overexpressing micro RNA-145

Objective To establish stable prostate cancer bone metastasis cell line overexpressing microRAN-145 (miR-145)for the study of the mechanism of miR-145 in bone metastasis.Methods pMSCV-miR-145 plasmids and retroviruses of pMSCV-vector

Micro-environmentally Restricted Yeast Cell Growth within Ca-alginate Microbeads

Micro-environmental restriction effects to yeast cell growth obtained within Ca-alginate microbeads are considered. It is complex phenomenon influenced by: (1) relaxation of expanded polymer network around the cellular clusters, (2) forces generated by cell growth inside the beads and (3) interactions between solvent, network parts and cells. The resulting effects are measured experimentally by estimating volume of microbeads and yeast cell concentration as function of time of cultivation. Comparative analysis of dynamics of cell growth and increase of microbead volume through four regimes indicates that reversible and irreversible local structural changes of Ca-alginate hydrogel induces micro-environmental restrictions to cell growth. The mechanism of restrictions includes both mechanical and electrostatic effects.

Measurement of Ca^(2+) Flow in Cochlear Cells Using Non-Invasive Micro-Test Technique

Objective To test Calcium ion(Ca2+) flow at the head and end of outer hair cells(OHCs) in resting state and in response to Nimodipine treatment.Methods Non-invasive micro-test techniques were used to study Ca2+ in isolated OHCs in adult guinea pigs.Results Four types of Ca2+ transport were identified in OHCs on basilar membrane tissue fragments:influx at the head of with efflux at the bottom(type 1):efflux at the head of OHCs with influx at the bottom(type 2);influx at the both head and bottom(type 3);and efflux at the both head and bottom(type 4).However,only type 1 and type 3 of Ca2+ ion transport were detected in the cochlea.We propose that Ca2+ ion transport exists in adult guinea pig cochlear OHCs in resting state and is variable.Ca2 + flow in OHC can be inhibited by Nimodipine in resting state.

Research on a Manifold Micro-channel Heat Sink Applied in High Concentrated Solar Cells

该文对歧管式微通道冷却技术在聚光电池冷却方面的应用进行了理论和实验研究。歧管式微通道冷却技术有助于在较小的空间内实现高热流密度冷却，较为适合高聚光比的密集阵列聚光电池系统。文中对歧管式微通道热沉热阻的计算方法进行改进，建立该种结构完全基于半经验公式的一维传热模型，并分析影响总热阻的主要因素。同时，对电池-热沉系统进行实验。实验结果表明，在此范围内实验与计算结果具有良好的一致性，电池-热沉系统的整体热阻低于1×10-4 m2·℃/W。结合聚光电池的性能模型，可获得电池的最大输出功率、效率、温度等性能参数随聚光比的变化情况。

微颗粒携带microRNA-126在细胞间信号传递中的作用

目的:探讨微颗粒(microparticles,MP)作为载体携带microRNAs(miRNAs)在介导细胞间信号传递中的作用。方法:用梯度离心的方法获得人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVEC)和293T细胞来源的微颗粒,将微颗粒与人急性单核细胞白血病细胞(THP-1细胞)共培养,然后应用transwell迁移实验观察THP-1细胞迁移情况;用实时定量聚合酶链反应(polymerase chain reaction,PCR)及Western blotting实验的方法,分析微颗粒携带miRNAs影响单核细胞迁移的机制。结果:通过transwell实验发现,HUVEC细胞来源的微颗粒(MPHUVEC)组THP-1细胞迁移数明显多于293T细胞来源的微颗粒(MP293T)组,差异有统计学意义(P<0.05);MPHUVEC组THP-1细胞CXCR4 mRNA及蛋白表达水平均明显高于MP293T组,差异有统计学意义(P<0.05)。HUVEC细胞分别给予lipo2000、lipo2000+miRNA inhibitor和lipo2000+miRNA-126 inhibitor不同处理获得的微颗粒为MPcon、MPneg-con、MPmiR-126 inhibitor,与MPcon组、MPneg-con组相比,MPmiR-126 inhibitor组THP-1细胞迁移数明显减少,差异有统计学意义(P<0.05);MPmiR-126 inhibitor组THP-1细胞CXCR4 mRNA及蛋白表达水平显著低于MPcon组、MPneg-con组,差异有统计学意义(P<0.05)。结论:HUVEC细胞来源的微颗粒可以携带miRNA-126促进单核细胞迁移,微颗粒作为载体可以携带miRNAs介导细胞间信号传递。

Micro-dsytrophin基因修饰的骨髓间充质干细胞移植后mdx鼠腓肠肌病理改变及micro-dystrophin的表达

目的探讨自体骨髓间充质干细胞(mMSCs)携带micro-dystrophin基因在移植鼠体内分化为有功能肌细胞的可能性。方法采用脂质体介导micro-dystrophin基因转染mdx小鼠mMSCs,通过尾静脉注射移植治疗mdx鼠,在移植后不同时间点对腓肠肌进行HE染色、计数核中心移位纤维(CNF)比例,并用免疫荧光法检测micro-dystrophin的表达。结果移植后各时间点腓肠肌病理改变较对照组有所改善,CNF比例下降,差异有统计学意义,部分肌细胞膜能表达micro-dystrophin蛋白,并随移植时间延长micro-dystrophin阳性肌纤维比例增加,分别达到3%(8周时)、6%(12周时)和8%(16周时)。结论自体mMSCs可携带外源性micro-dys-trophin基因在受体鼠体内分化为micro-dystrophin阳性肌细胞。

上调microRNA-34a抑制胶质瘤细胞的增殖及侵袭

目的探讨micro RNA-34a(mi R-34a)在胶质瘤组织中的表达情况以及对人脑胶质瘤细胞系U251增殖及侵袭的影响。方法选取川北医学院附属医院2013年3月至2017年3月胶质瘤组织标本30例和重症脑外伤需行手术者正常脑组织标本10例作为研究对象,采用荧光定量PCR法检测mi R-34a在胶质瘤组织表达情况。体外实验,将人工合成的mi R-34a模拟物mi R-34a mimic转染至U251细胞系,采用荧光定量PCR、MMT、Transwell法检测mi R-34a在U251细胞系中表达以及对U251细胞增殖和侵袭能力的影响。依据细胞转染情况,分为Control组(不转染任何基因)、Mock组(转染mi RNA-neg序列)和mi RNA-34a mimic组(转染mi RNA-34a mimic序列)。结果 mi RNA-34a在人脑胶质瘤组织中相对表达水平为(0.35±0.07),低于正常人脑组织的(1.00±0.13),差异有统计学意义(P<0.05);转染后,荧光定量PCR结果显示,Control组、Mock组、mi RNA-34a mimic组mi RNA-34a相对表达水平分别为(1.00±0.08)、(0.98±0.11)和(6.19±0.34),mi RNA-34a mimic组与Control、Mock组比较,差异有统计学意义(P<0.05);MMT结果显示,在不同时间点,mi RNA-34a mimic组U251细胞增殖抑制率高于Control组、Mock组,差异有统计学意义(P<0.05);Transwell结果显示,Control组、Mock组、mi RNA-34a mimic组侵袭细胞数分别为(90.53±5.84)个、(88.21±5.04)个和(27.46±2.76)个,mi RNA-34a mimic组与Control、Mock组比较,差异有统计学意义(P<0.05)。结论mi R-34a在胶质瘤组织中表达下调,上调mi R-34a表达可抑制胶质瘤细胞的增殖及侵袭。

MicroRNA-33b通过靶向调控SALL4的表达抑制肝细胞癌细胞增殖

目的:探索微小RNA-33b(micro RNA-33b,mi R-33b)在肝细胞癌(hepatocellular carcinoma,HCC)中的表达及调控HCC细胞增殖的相关分子机制。方法:收集配对的HCC及癌旁组织32对,分别采用实时荧光定量PCR和Western印迹法检测人类婆罗双树样基因4(Sal-like 4,SALL4)RNA和蛋白表达,MTT实验检测HCC细胞增殖,萤光素酶报告基因检测验证mi R-33b与SALL4基因的靶点关系。结果:Mi R-33b在HCC组织中的表达显著低于癌旁组织(P<0.001)。过表达mi R-33b能显著降低HCC LH86细胞的增殖。SALL4是mi R-33b的靶基因,其蛋白表达被mi R-33b负调控。过表达SALL4能逆转mi R-33b对LH86细胞增殖的抑制作用。SALL4在HCC组织中的表达显著高于癌旁组织(P<0.001)。结论:Mi R-33b对HCC细胞增殖的抑制作用是通过负调控SALL4的表达而实现。