Objective To review the advance in the experimental studies of microRNA(miRNA) and the relationship between miRNA and stem cells. Methods The related literature was reviewed, and the research findings of miRNA and stem cell were summarized. Results miRNA was noncoding small RNA (20-25 nt) involved in posttranscriptional change, that have been shown to regulate gene expressions. Ithas been reported that some kinds of miRNAs were likely important regulators forstem cells maintaining their state of selfrenewal，and play key roles in theirdifferentiation. Conclusion miRNA as regulation of gene expressions, can be served as a new way for stem cells research.
Objective To explore the differential expression of circular RNAs (circRNAs) in polycystic ovary syndrome (PCOS) by bioinformatics, and predict the microRNAs (miRNAs) associated with them. Methods The expression profile of cumulus cells gene chip in PCOS was searched in the Gene Expression Omnibus database, and differential circRNAs were screened by GEO2R tool of the database. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes signaling pathways of different circRNA genes were analyzed using the DAVID 6.8 database. Circular RNA interactome was used to predict the potential regulated miRNAs. Cytoscape software was used to establish circRNA-miRNA network map. The potential regulatory miRNAs were predicted by the 10 circRNAs with the most significant differences in up-regulation and down-regulation. Results A total of 247 circRNAs were obtained in PCOS, and 277 miRNAs binding to up-regulated circRNA genes and 125 miRNAs binding to down-regulated circRNA genes were predicted. The top 10 miRNAs that could bind to multiple differential circRNAs were hsa-miR-557, hsa-miR-507, hsa-miR-224, hsa-miR-136, hsa-miR-127-5p, hsa-miR-579, hsa-miR-502-5p, hsa-miR-186, hsa-miR-1253, and hsa-miR-432. Conclusion The differential expression analysis of circRNAs is helpful to understand the main role of circRNAs in PCOS, and the prediction of potential regulated miRNAs can help to understand the pathogenesis of the disease.
Objective To investigate the effects of expression of TNFα mRNA on glucose uptake in both the liver and skeletal muscle after endotoxemia. Methods In the mice with intraperitoneal injection of lipopolysaccharide (LPS), the changes of TNFα level of plasma and uptake of 2-deoxyglucose (2-DG) in the isolated soleus muscle and hepatic tissues were determined, then the reinstatement of glucose uptake by injecting TNF-McAb for 3 days was also observed. In addition, changes of TNFα mRNA expression of liver were evaluated. Results The expression of TNFα mRNA in the liver showed markedly increased in the first 3 hours post endotoxemia and remaind high for 3 days, and the plasma TNFα level paralleled with TNFα mRNA expression of liver also was elevated. The basal uptake of 2-DG both in muscle and liver were markedly increased, but the stimulated 2-DG uptake with insulin was greatly reduced as compared with the control. In addition, these abnormalities of 2-DG uptake can be partially corrected by neutralization of the circulatory TNFα by administration of TNF-McAb. Conclusion The disorders of glucose uptake of the liver and the muscle due to the overexpression of TNFα mRNA and elevated circulatory TNFα level may be the mechanism of insulin resistance after endotoxemia.
ObjectiveTo investigate the expression of miR-195 and the underlying molecular mechanisms of miR-195 regulating HMGB1 in diabetic retinopathy (DR). MethodsExtract 5 ml venous blood from DR patients, diabetes mellitus (DM) patients and normal subjects, then extract and perificate plasma total RNA. MicroRNA array and real time polymerase chain reaction (RT-PCR) was used to screen out miRNAs which were expressed with significant differences in the serum of patients with DR. Bioinformatics was employed to predict the miR-195 related to high mobility group box 1 (HMGB1) regulation. Next, miR-195 was down-regulated or up-regulated in umbilical vein endothelial cells through transfection of miR-195 inhibitor and miR-29b mimics respectively.Then we analyzed expression of HMGB1 mRNA and protein by RT-PCR and Western blot. ResultsMicroRNA array results showed the expression of miR-195 in DR group is decreased by 8.34 times and 11.47 times compared with DM group and the normal group. RT-PCR verification results conforms to the microRNA array results. Compared with the DM group (F=0.034, t=8.057) and the normal group (F=0.370, t=9.522), the expression of miR-195 in DR group were significantly reduced, the differences were statistically significant (P < 0.05). RT-PCR showed that the expression of HMGB1 mRNA was significantly decreased in up-regulation group, compared with blank (F=0.023, t=11.287) and negative control group (F=0.365, t=7.471), the difference was statistically significant (P < 0.05). The expression of HMGB1 mRNA was significantly increased in down-regulation group, compared with blank (F=0.053, t=10.871) and negative control group (F=0.492, t=6.883), the difference was statistically significant (P < 0.05). Western blot showed that the expression of HMGB1 protein was significantly decreased in up-regulation group, compared with blank (F=0.021, t=8.820) and negative control group (F=0.039, t=7.401), the difference was statistically significant (P < 0.05); and significantly increased in down-regulation group, compared with blank (F=0.186, t=10.092) and negative control group (F=0.017, t=12.923), the difference was statistically significant (P < 0.05). ConclusionMiR-195 can inhibit the expression of HMGB1, reduce the inflammation and angiogenesis, thereby delaying or inhibiting the occurrence and development of DR.
Objective To construct the expression short hairpin RNA （shRNA） targeting gene kir2. 1 in rat myocardial cells, named pEGFP6 kir2. 1, and to observe the effects on the expression of messenger RNA（mRNA） and protein of gene kir2. 1 as well as the changes of myocardial beating rates. Methods Five RNA interference （RNAi） sites targeting the rat kir2. 1 gene was selected, designed and synthesized five pairs of oligonucleotides fragments ,annealed them to double-strand, then cloned them into the vectors containing U6 promoter,obtained the vector expressing five aim genes. Rat myocardial cells were divided into three groups： Experimental group, negative plasmid control group and normal control group. Reverse transcription-polymerase chain reaction（RT PCR） and Western-blot were carried out to detect the expression of the mRNA and protein of gene kir2.1 and the beating rates of myocardial cells were observed after 72 h. Results The expression of mRNA and protein of gene kir2. 1 of experimental group were markedly lower than that of other two control groups after 72 h（P〈0.01）. There was no statistically significant between two control groups. The beating rate in experimental group was much faster than other two control groups （P〈0.01）, remained unchanged in both negative plasmid control group and normal control group. Conclusion Plasmid pEGFP6-kir2.1 could suppress the expression of the mRNA and protein of kir2.1 and increase the rat cardiac muscle cell beats.
Objective To observe the effect of RNA interference (RNAi) on HepG2 hepatic cancer cell by small interfering RNA (siRNA). Methods siRNA targeting vascular endothelial growth factor (VEGF) gene was transfected into HepG2 cells by LipofectimineTM 2000. The VEGF mRNA and protein were respectively detected by real-time quantitive PCR and Western blot, and the concentration of VEGF protein in the cell culture supertant was determined by ELISA at 48 h after culture. Results The average efficiency of siRNA transfection was (90.4±2.9)% after 6 h cell culture. The expressions of VEGF mRNA and protein in HepG2 cells could be effectively suppressed by siRNA, and the concentration of VEGF protein in the cell culture supertant was also decreased. Conclusion siRNA can knock down the expression of VEGF gene and decrease the concentration of VEGF protein in HepG2 cells.
Objective To investigate the relationship between gene expression of endothelin-3 (ET-3） and inflammation of acute pancreatitis （AP） in rats. Methods Fifty-four rats were divided randomly into 4 groups: sham operation group, AP group, arterial injection group and vein injection group. AP was induced by reverse intra-bile duct infusion 4.5% sodium taurocholate, treated with low dose dopamine 〔5 μg/（kg·min）〕 by injecting arterial or tail vein. Rats were sacrificed at 1， 6 and 24 h after the induction of AP. The mRNA expression of ET-3 was evaluated by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and pathological changes was observed in rats. Results Expression of ET-3 mRNA could be detected from 1 up to 24 h after the induction of pancreatitis. Expression of ET-3 mRNA of sham operation group was decreased significantly compared with other three groups. Expression of ET-3 mRNA showed a significant decrease by arterial injection dopamine than that by tail vein (P＜0.05， P＜0.01). The pathologic score in AP group was the highest, vein injection group was the next one, and score in sham operation group was the lowest. Conclusion There are significant relationship between inflammation of AP and expression of ET-3 mRNA. Dopamine administration by arterial injection is more effective than that by tail vein injection.
ObjectiveTo investigate the expressions of cartilage degenerative related genes in meniscus, and to evaluate the potential effect of meniscal damage on cartilage degeneration, and to analyze the relationship between microRNAs (miRNAs) expression and cartilage degeneration. MethodsMeniscal tissue was collected from 5 patients undergoing partial meniscectomy between September 2012 and October 2013 (experimental group), and normally meniscal tissue without tearing from amputees was used as controls (control group). Pathological changes of menisci were observed; and real-time fluorescent quatitative PCR was performed to examine the relative expression levels of cartilage degenerative related genes and miRNAs:Aggrecan (ACAN), type X collagen (COL10A1), matrix metalloproteinases 13 (MMP-13), CCAAT enhancer binding protein β (CEBP-β), a disintegrin and metalloproteinase with thrombospondinmotif 5 (ADAMTS-5), miR-193b, miR-92a, and miR-455-3p in meniscus. ResultsThere were varying degrees of degenerative pathological changes in torn meniscus of experimental group. Compared with normal meniscus of control group, the expression of ACAN was decreased, while the expressions of COL10A1, CEBP-β, ADAMTS-5, and MMP-13 were increased in torn meniscus of experimental group; and significant difference was found (P<0.05) except ACAN and MMP-13 (P>0.05). The expressions of miR-92a, miR-455-3p, and miR-193b in torn meniscus of experimental group were significantly higher than those in normal meniscus of control group (P<0.05). ConclusionMeniscal tissue has the intrinsic tendency of degeration after meniscus tear. The torn meniscus has greater stimulative impact on cartilage degeneration than normally morphological meniscus without tearing. The cartilage degenerative related miRNAs, including miR-193b, miR-92a, and miR-455-3p may contribute to the up-regulation of osteoarthritis.
Objective To explore the effects of dioscin (Dio) on airway inflammation and microRNA-155 (miR-155)/cyclooxygenase 2 (COX-2)/prostaglandin E2 (PGE2) pathways in asthmatic mice. Methods Seventy mice were randomly divided into control group, model group, inhibitor negative control group (inhibitor-NC group), miR-155 inhibitor group, and Dio group, Dio+miR-155 mimic negative control group (Dio+mimic-NC group), Dio+miR-155 mimic group, with 10 mice in each group. Using house dust mite to induce the preparation of asthma mouse models; enzyme linked immunosorbent assay was used to detect the levels of PGE2, tumor necrosis factor α (TNF-α), cysteyl leukotrienes (CysLTs), cysteyl leukotriene receptor 1 (CysLTR1) and interleukin (IL)-4, IL-5, IL-13 in mouse bronchoalveolar lavage fluid (BALF); hematoxylin-eosin and periodic acid-Schiff staining were used to observe the infiltration of inflammatory cells around the airway and the secretion of mucus by goblet cells; quantitative real-time PCR was used to detect the expression levels of miR-155 and COX-2 mRNA in mouse lung tissue; Western blot was used detect the expression of COX-2 protein in mouse lung tissue. Results MiR-155 inhibitor and Dio could reduce the levels of PGE2, TNF-α, CysLTs, CysLTR1 and IL-4, IL-5, IL-13 in BALF of asthmatic mice, reduce lung tissue inflammatory cell infiltration and goblet cell mucus secretion, and reduce lung tissue miR-155, COX-2 mRNA and protein expression; and miR-155 mimic could significantly weaken the anti-asthma effect of Dio. Conclusion The anti-asthma effect of Dio may be related to the inhibition of miR-155/COX-2/PGE2 pathway to reduce airway inflammation in asthmatic mice.
Objective To investigate the effects of X-ray dose on the expressions of microRNA-221 （miR-221） and phosphatase and a tensin homolog deleted from chromosome10 （PTEN） in human colorectal carcinoma （CRC） cells. Methods Human CRC-derived cell line， Caco2， was cultured conventionally. The cells were divided into five groups and exposed to different doses of X-ray （0， 2， 4， 6， and 8 Gy） respectively. The total RNA and protein of the Caco2 cells were extracted after irradiation， and the miR-221 and PTEN mRNA expressions were detected by real-time RT-PCR.Moreover， the protein alteration of PTEN in Caco2 cells was detected by Western-blot analysis. Results The radiation dose of X-ray significantly affected the expressions of miR-221 and PTEN protein in human Caco2 cells in a dose-depen-dent manner. Moreover， the miR-221 expression level was up-regulated gradually with the increase of irradiation dose， on the contrary， the PTEN protein expression level was down-regulated gradually （P＜0.01）. Conclusion The radiation dose can affect the miR-221 and PTEN protein expression pattern in CRC cells.