Research progress of the structure and function of untranslated regions of enterovirus 71 genome / 中华实验和临床病毒学杂志

Enterovirus 71 (EV71) is one of the important pathogens of hand, foot and mouth disease (HFMD) in infants and young children. It is also a very important and common virus after poliovirus which is associated with severe acute neurological disease. Mutations or spatial structure changes in untranslated regions (UTRs) may affect the ability of the virus to translate and replicate, as well as the affinity of the virus for cellular tissue, and even lead to changes in virulence. At present, the pathogenic mechanism of EV71 is still unknown, and the study of untranslated regions is an indispensable part. Here we briefly review the development of the study of basic structure and function of EV71 untranslated regions in recent years.

MTHFR 3′-untranslated region polymorphisms contribute to recurrent pregnancy loss risk and alterations in peripheral natural killer cell proportions / 대한생식의학회지

OBJECTIVE: To identify the associations between polymorphisms of the 3′-untranslated region (UTR) of methylenetetrahydrofolate reductase (MTHFR) gene, which codes for an important regulatory enzyme primarily involved in folate metabolism, and idiopathic recurrent pregnancy loss (RPL) in Korean women. METHODS: The study population comprised 369 RPL patients and 228 controls. MTHFR 2572C>A, 4869C>G, 5488C>T, and 6685T>C 3′-UTR polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis or by TaqMan allelic discrimination assays. Natural killer cell proportions were determined by flow cytometry. RESULTS: The MTHFR 2572-5488-6685 (A-C-T) haplotype had an adjusted odds ratio of 0.420 (95% confidence interval, 0.178–0.994; p=0.048) for RPL. Analysis of variance revealed that MTHFR 4869C>G was associated with altered CD56⁺ natural killer cell percentages (CC, 17.91%±8.04%; CG, 12.67%±4.64%; p=0.024) and folate levels (CC, 12.01±7.18 mg/mL; CG, 22.15±26.25 mg/mL; p=0.006). CONCLUSION: Variants in the 3′-UTR of MTHFR are potential biomarkers for RPL. However, these results should be validated in additional studies of ethnically diverse groups of patients.

Alternative Polyadenylation in Human Diseases

Varying length of messenger RNA (mRNA) 3′-untranslated region is generated by alternating the usage of polyadenylation sites during pre-mRNA processing. It is prevalent through all eukaryotes and has emerged as a key mechanism for controlling gene expression. Alternative polyadenylation (APA) plays an important role for cell growth, proliferation, and differentiation. In this review, we discuss the functions of APA related with various physiological conditions including cellular metabolism, mRNA processing, and protein diversity in a variety of disease models. We also discuss the molecular mechanisms underlying APA regulation, such as variations in the concentration of mRNA processing factors and RNA-binding proteins, as well as global transcriptome changes under cellular signaling pathway.

Genomic Analysis of miR-21-3p and Expression Pattern with Target Gene in Olive Flounder

MicroRNAs (miRNAs) act as regulators of gene expression by binding to the 3’ untranslated region (UTR) of target genes. They perform important biological functions in the various species. Among many miRNAs, miR-21-3p is known to serve vital functions in development and apoptosis in olive flounder. Using genomic and bioinformatic tools, evolutionary conservation of miR-21-3p was examined in various species, and expression pattern was analyzed in olive flounder. Conserved sequences (5’-CAGUCG-3’) in numerous species were detected through the stem-loop structure of miR-21-3p. Thus, we analyzed target genes of miR-21-3p. Among them, 3’ UTR region of PPIL2 gene indicated the highest binding affinity with miR-21-3p based on the minimum free energy value. The PPIL2 gene showed high expression levels in testis tissue of the olive flounder, whereas miR-21-3p showed rather ubiquitous expression patterns except in testis tissue, indicating that miR-21-3p seems to control the PPIL2 gene expression in a complementary repression manner in various tissues of olive flounder. Taken together, this current study contributes to infer the target gene candidates for the miR-21-3p using bioinformatics tools. Furthermore, our data offers important information on the relationship between miR-21-3p and target gene for further functional study.

Analysis of variants located in 3'UTR regions of NOTCH1 and JAG1 genes for children with conotruncal heart defects / 上海交通大学学报（医学版）

Objective · To explore the correlation between variants located in 3' untranslated regions (3'UTR) of NOTCH1 and JAG1 genes and conotruncal heart defects (CTD). Methods · Six hundred CTD children without 22q11 deletion and three hundred healthy children were enrolled in this hospital-based case-control study. Variants located in the 3'UTR regions of NOTCH1 and JAG1 genes were detected by high-throughput sequencing. The accuracy of the variants were verified by PCR and Sanger sequencing. Online software PicTar, TargetScan and microRNA.org were used to make functional predictions. Results · One mutation and three SNPs were found in the 3'UTR of NOTCH1. Three mutations and six SNPs were found in the 3'UTR of JAG1. The genotypic distributions of two SNPs (rs3840074 and rs8708) located in JAG13'UTR between CTD group and the controls were statistically significant (both P<0.05). Results of prediction showed that all the four mutations and two meaningful SNPs could bind to microRNA. Conclusion · The variants located in 3'UTR regions of NOTCH1 and JAG1 genes may be related to the occurrence of CTD.

Construction of Nfic gene 3′UTR dual luciferase reporter vector and targeting verification between Nfic and miR-20a / 天津医药

Objective To construct a luciferase reporter vector containing the 3′untranslated region (3′UTR) of nuclear factor I-C (nuclear factor I-C, Nfic), and apply dual luciferase reporter gene system to determine the association between microRNA-20a (miR-20a) and its potential target gene Nfic. Methods The potential complementary binding sites of miR-20a and Nfic were predicted by Targetscan. The 3′UTR of Nfic fragment amplified by PCR was cloned into luciferase reporter vector MIR- Report Luciferase. The luciferase reporters containing 3′ UTR of Nfic and miR- 20 mimics (experimental group) or NC mimics (control group) were co-transfected into 293-AD cells. Cells were collected, and then dual-luciferase reporter assay was performed to detect the luciferase activity of the two groups of cells, consequently the relationship between miR-20a and Nfic was identified. The miR-20a mimics and NC mimics were transfected into marrow stromal cell line ST2 respectively. The total cell lysates were collected, and the expression level of NFIC was detected by Western blotting assay. Results Results of double enzyme digestion and DNA sequencing showed that sequence of luciferase reporter vector was correct. miR-20a specificity bounded to Nfic 3′UTR and inhibited the luciferase activity of the reporter construct (P<0.05). Western blotting assay showed that the NFIC protein level was obviously down-regulated in ST2 cells after the transfection of miR-20a mimics compared with that of control. Conclusion The luciferase reporter vector containing the 3′UTR of Nfic is constructed successfully, which confirms that miR-20a can direct effect on Nfic3′UTR and repress its luciferase activity.

Effects of ZEB2 3′UTR Transfection on Proliferation, Invasion and Migration in Human Gastric Epithelial Cell GES-1 / 天津医药

Objective To explore the effects of zinc finger E-box binding protein (ZEB)2 3′UTR gene transfection on proliferation, invasion and migration in human gastric epithelial cell line GES-1. Methods The synthetic ZEB2 3′UTR and miR-200b micmics were transfected into GES-1 cell line by lipofectamine 2000. We set up control grop, the mutation group and ZEB2 3′UTR group. Real-time quantitative PCR was performed to evaluate the expression levels of miR-200a/b/c and ZEB1/ZEB2 mRNAs after transfection.And then we set up control group, ZEB2 3′UTR group, ZEB2 3′UTR+negative control group and ZEB2 3′UTR+miR-200b micmics group. The protein expression levels of ZEB1, ZEB2, matrix metallopro-teinases (MMP) 2/9 and proliferating cell nuclear antigen (PCNA) were detected by Western blot assay. The invasion and mi-gration capability were analyzed by transwell assay and wound healing test. MTT assay was used to detect the proliferation ability. Results Compared with control group and mutation group, the expressions of miR-200a/b/c were significantly de-creased, especially for miR-200b. And the expressions of ZEB1/ZEB2 were significantly increased at both mRNA and pro-tein levels after transfected with the ZEB2 3′UTR, enhancing the capability of migration,invasion,and proliferation (P <0.05). Compared with ZEB2 3′UTR group, the capabilities of proliferation,invasion and migration were significantly lower in combined group. Conclusion ZEB2 3′UTR can increase the ability of cell proliferation, invasion and metastasis through regulating the levels of miR-200a/b/c, and then influence the regulation of transcription of the target gene, which could lead to malignant transformation of GES-1 cells.

GATA4 Expression During Induction of the Cardiomyocyte-Like Cells Differentiation Regulated by miR-122 / 天津医药

Objective To identify the miR-122 which regulateing GATA4 expression during the induction of rat bone marrow mesenchymal stem cells (bMSCs) differentiating into cardiomyocyte-like cells. Methods BMSCs were isolat-ed from bone marrow and induced to differentiate into cardiomyocyte-like cells using 5-azacytidine. The miR-122 which may regulate expression of GATA4 were predicted using miRanda and TargetScan softwares and identified by dual luciferase report system. The expressions of miR-122 and GATA4 were determined using q-PCR during the differentiation of bMSCs into cardiomyocyte-like cells. Results The induced cells were completely in contacted with adjoining cells and uniform in shape and aligned parallelly. Cardiac troponin I (cTnI) expression was detected by immunofluorescence cytochemistry. Using dual luciferase reporter system in vitro, miR-122 were proved to be able to effectively inhibit GATA4 expression by binding the 3′UTR of GATA4 mRNA. q-PCR results showed that the expression of miR-122 is negatively correlated with that of GATA4 mRNA transcription. Conclusion These results indicated that miR-122 regulate the expression of GATA4 during the induction of cardiomyocyte-like cells.

Association between genetic polymorphisms of interleukin-12 p40 3' untranslated region and hepatitis C virus infection / 中华传染病杂志

Objective To investigate the association between single nucleotide polymorphism (SNP) of interleukin-12 (IL-12) p40 3'untranslated region rs3212227 site and hepatitis C virus (HCV) infection. Methods Patients with hepatitis C (n=127) were genotyped and analyzed for the SNP of IL-12 p40 rs3212227 using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing. The serum HCV RNA levels of patients with hepatitis C were detected using real time fluorescence quantitative-polymerase chain reaction (FQPCR). Inter-group comparisons of genotype and allele frequency were analyzed using chi-square test.Results In patients with hepatitis C, the frequencies of AA, AC and CC genotypes of IL-12 p40 rs3212227 site were 34. 6% ,40. 9% and 24. 4% , respectively,and the frequencies of allele A, C of IL12 p40 rs3212227 site were 55.1% and 44. 9%, respectively. The frequency of rs3212227 C allele in patients with HCV RNA ≥2. 0× 106 copy/mL was higher than that in patients with HCV RNA <2. 0 ×106 copy/mL (χ2 =7. 367, P = 0. 007). The frequency of rs3212227 C allele in responders to interferon (IFN) therapy was lower than that in patients with nonresponse to IFN therapy (χ2 =4. 942,P=0. 026). Conclusions The SNP of rs3212227 is correlated with HCV infection. The carriers with C allele may be susceptible to HCV infection, while resistant to IFN therapy.

Influence of 3' untranslated region of vascular endothelial growth factor-C gene on the expression of luciferase / 解放军医学杂志

Objective To construct a luciferase gene expression vector containing full-length 3' untranslated region(3'UTR)of mouse vascular endothelial growth factor-C(VEGF-C)gene,and to observe the effects of VEGF-C 3'UTR on luciferase gene expression by a double-fluorescence report system.Methods Polymerase chain reaction(PCR)was used to amplify VEGF-C 3'UTR and a 312bp VEGF-C coding region(CR)fragment from full-length VEGF-C cDNA in mouse Lewis lung cancer cells.The luciferase expression vectors containing VEGF-C 3'UTR or VEGF-C CR were constructed by subcloning the PCR products to luciferase reporter vector pGL3-Promoter using gene engineering technology,and then they were transfected to mouse Lewis lung carcinoma cells by LipofectamineTM 2000.The activities and mRNA expression of luciferase were detected by Dual-Luciferase Reporter System and quantitative RT-PCR,respectively.Results Mouse VEGF-C 3'UTR(429bp)and VEGF-C CR(312bp)were successfully amplified by PCR.The VEGF-C 3'UTR and VEGF-C CR fragments were successfully inserted into pTA2 vector,and then subcloned to pGL3-Promoter vector at Xba Ⅰ site by using restriction endonucleases analysis.The DNA sequences and insertion orientation of PCR products were all correct by sequencing analysis.The resulted luciferase expression plasmids were named pGL3-VEGF-C 3'UTR and pGL3-VEGF-C CR,respectively.Dual-Luciferase Reporter System detection and quantitative RT-PCR showed that in Lewis lung carcinoma cells,the activities of luciferase and expression of luciferase mRNA in the pGL3-Promoter group were higher than that in the pGL3-VEGF-C 3'UTR group,and there was no significant difference between pGL3-VEGF-C CR group and pGL3-Promoter group.Conclusion VEGF-C 3'UTR can inhibit luciferase gene expression.