Ectopic expression of Chrysanthemum CDM19 in Arabidopsis reveals a novel function in carpel development

BACKGROUND: APETALA3 (AP3) has significant roles in petal and stamen development in accordance with the classical ABC model. RESULTS: The AP3 homolog, CDM19, from Chrysanthemum morifolium cv. Jinba was cloned and sequenced. Sequence and phylogenetic analyses revealed that CDM19 is of DEF/AP3 lineage possessing the characteristic MIKC-type II structure. Expression analysis showed that CDM19 was transcribed in petals and stamens of ray and disc florets with weak expression in the carpels. Ectopic expression of CDM19 in Arabidopsis wild-type background altered carpel development resulting in multi-carpel siliques. CDM19 could only partially rescue the Arabidopsis ap3­­3 mutant. CONCLUSIONS: Our results suggest that CDM19 may partially be involved in petal and stamen development in addition to having novel function in carpel development.

Flavonoids from the aerial parts of Lespedeza cuneata / 药学学报

The chemical constituents of the aerial parts of Lespedeza cuneata (Dum. Cour.) G. Don were investigated using chromatographic techniques, such as silica gel, reversed phase MPLC and preparative HPLC. Five compounds were isolated and their structures were elucidated by spectroscopic data and physicochemical properties, which were identified as 7-O-glucosyllaburnetin (1), kaempferol-3-O-β-D-galactopyranoside (2), kaempferol-3-O-α-L-rhamnoside (3), vitexin (4), and isovitexin (5). Among those, compound 1 is a new compound, compounds 2-3 were isolated from this plant for the first time. Compounds 1-5 were tested for their anti-ulcerative colitis activity by dual luciferase report gene assay targeting xbp1. Compared with control group, compound 1 showed a certain activity on activating the transcription of xbp1, with its relative activating ratio being 1.80 times.

Establishment of stable cell line expressing human bocavirus type 1 non-structural protein NS1 and its trans-transcriptional activation / 生物工程学报

Human bocavirus 1 (HBoV1) non-structural protein NS1 is a multifunctional protein important for virus replication and induction of apoptosis in host cell. To better understand the function of the NS1 protein, it is urgent to address reducing the toxicity of NS1 to host cells. In the present study, we established a stable cell line that regulates expression of NS1 of HBoV1. The recombinant lentivirus plasmid containing a regulatable promoter fused with ns1 gene was constructed and transfected into HEK 293T cells using transfection reagent. The HEK 293T cell lines stably expressing NS1-100 and NS1-70 proteins were established by screening resistant cells with puromycin and inducing NS1 expression with doxycycline. The expression of NS1 protein was determined by fluorescent labeling protein and Western blotting. HBoV1 promoter was transfected into stably expressing NS1 cell line and its trans-transcriptional activity was analyzed. The results showed that NS1 protein was expressed stably in the established cell lines and had a strong activation activity on the HBoV1 promoter driving luciferase gene. Taken together, this study provides a solid basis for further research on the function of NS1 and the pathogenesis of human bocavirus.

Recent advances in small activating RNA and tumors / 肿瘤

RNA activation (RNAa) is gene expression up-regulation mediated by small activating RNA (saRNA). At present, the research of RNAa mainly focuses on the tumors. The gene activation mediated by RNAa has obvious advantages in the research and treatment of tumors. By up-regulating the expression of tumor suppressor gene, saRNA can inhibit the malignant biological behaviors of tumor cells, such as proliferation, invasion and metastasis, so as to achieve the therapeutic effects at the gene level. This article summarizes the recent reports on RNAa mediated by saRNA in the treatment of tumors, and also analyzes the clinical application prospects of saRNA.

Dengue virus infection induces chromatin remodeling at locus AAEL006536 in the midgut of Aedes aegypti / La infección por virus dengue induce remodelación de la cromatina en el locus AAEL006536 en el intestino medio de Aedes aegypti

Abstract: Objective: To identify and characterize Aedes aegypti's AAEL006536 gene proximal upstream cis-regulatory sequences activated by dengue virus infection. Materials and methods: A. aegypti Rockefeller strain mosquitoes were blood fed or infected with dengue virus 2. Open chromatin profiling was then carried out in pools of midguts from each group of mosquitoes. Results: The proximal upstream region does not contain open chromatin sites in the midguts of blood-fed mosquitoes as detected by FAIRE-qPCR. In contrast, two cis-regulatory sites were identified in the same upstream region of dengue virus-infected mosquito midguts. The distal sequence contains STAT-, REL- and C/EBP-type transcription factor binding sites. Conclusion: The activation of two proximal cis-regulatory sequences, induced by dengue virus infection, is mediated by chromatin remodeling mechanisms. Binding sites suggest a dengue virus infection-induced participation of immunity transcription factors in the up-regulation of this gene. This suggests the participation of the AAEL006536 gene in the mosquito's antiviral innate immune response.

Resumen: Objetivo: Identificar y caracterizar las secuencias reguladoras activadas por la infección por virus dengue en la región proximal del gen AAEL006536 de Aedes aegypti. Material y métodos: Mosquitos de la cepa Rockefeller de A. aegypti se infectaron con virus dengue o se alimentaron con sangre. Se obtuvieron los perfiles de cromatina abierta del locus en los intestinos de cada uno de los grupos. Resultados: Se identificaron dos sitios reguladores solo en los intestinos de mosquitos infectados por virus dengue. El sitio distal contiene sitios de unión a factores de transcripción tipo REL, STAT y C/EBP. Conclusiones: La activación de dos sitios reguladores proximales está mediada por la remodelación de la cromatina. Los sitios de unión a factores de transcripción en el sitio regulador distal sugieren la participación de las vías de inmunidad en la regulación del gen. Esto sugiere la participación de este gen en la respuesta inmune del mosquito frente a la infección viral.

SENP3-mediated de-SUMOylation of p53 inhibits its activity in human lung cancer cell lines / 上海交通大学学报（医学版）

Objective • To explore the effect of de-SUMOylation of p53 by SENP3 on its transcriptional activity in lung cancer. Methods • Lung cancer cell lines A549 (p53 wild type) and H1299 (p53 null) were used. Wild type p53 as well as sumoless mutants K386R or E388A were introduced into the cells. Co-immunoprecipitation was performed to detect SUMOylation of p53 under resting status or oxidative stress. Immunofluorescence was applied to observe the localization of p53 WT and K386R or E388A. Dual luciferase reporter assay and quantitative real-time PCR of p21 were performed to monitor the transcriptional activity of p53 WT and K386R or E388A. Growth curve was analyzed to demonstrate the effect of p53 WT and K386R or E388A on cell proliferation. Results • SENP3 was able to mediate de-SUMOylation modification of p53 under oxidative stress. Similar to WT p53, K386R and E388A p53 kept nuclear localization. Further, SENP3 knockdown or oxidative stress did not induce translocation of p53 from nucleus to cytoplasm. However, compared to WT, the transcriptional activation of K386R and E388A p53 were inhibited. Moreover, SENP3 inhibited the activity of p53 in A549. K386R and E388A p53 attenuated the inhibitive activity on cell proliferation in H1299. Conclusion • SENP3-mediated de-SUMOylation of p53 is one of mechanisms of its inactivation as tumor suppressor in lung cancer.

Report of a novel mutation in the SLC26A2 gene found in a Colombian adult patient with diastrophic dysplasia / Reporte de una nueva mutación en el gen SLC26A2 en un paciente adulto colombiano con displasia diastrófica

Summary Background. Diastrophic dysplasia is an osteochondrodysplasia belonging to the group of dysplasias caused by mutations in the diastrophic dysplasia sulfate transporter. This sindrome is a micromelic dysplasia with multiple bone deformities of the hands, feet, knees and spine. Objective. Describe the first report of diastrophic displasia in Colombia Materials and methods. In this paper a Colombian adult patient with diastrophic dysplasia whose clinical diagnosis was confirmed at the molecular level is reported. Results. In this first report of diastrophic dysplasia in Colombia we found that the patient was compound heterozygote for the already reported Arg279Trp substitution and an unpublished mutation, a Ser157Thr substitution in the SLC26A2 gene. Conclusion. Bioinformatic analysis on the latter mutation suggested that it could correspond to a deleterious mutation because it is in a highly conserved domain of the sulfate transporter.

Resumen Antecedentes. La displasia diastrófica es una osteocondrodisplasia que pertenece al grupo de las enfermedades genéticas del esqueleto causadas por mutaciones en los transportadores de sulfato. Se presenta como una displasia micromélica con afectación de múltiples huesos y deformidades en manos, pies, rodillas y columna vertebral. Objetivo. Describir el primer reporte de displasia diastrófica en Colombia. Materiales y métodos. Se reporta un adulto colombiano con esta displasia, con confirmación clínica, radiológica y molecular. Resultados. En este primer reporte colombiano, se encontró que la paciente presentó una mutación heterocigota compuesta, de Arg279Trp y Ser157Thr, esta última no reportada previamente, en el gen SLC26A2. Conclusión. El análisis bioinformático de la mutación nueva sugiere que podría corresponder a una mutación deletérea dado que el dominio afectado en el transportador de sulfatos es altamente conservado.

CpG methylation at GATA elements in the regulatory region of CCR3 positively correlates with CCR3 transcription

DNA methylation may regulate gene expression by restricting the access of transcription factors. We have previously demonstrated that GATA-1 regulates the transcription of the CCR3 gene by dynamically interacting with both positively and negatively acting GATA elements of high affinity binding in the proximal promoter region including exon 1. Exon 1 has three CpG sites, two of which are positioned at the negatively acting GATA elements. We hypothesized that the methylation of these two CpGs sites might preclude GATA-1 binding to the negatively acting GATA elements and, as a result, increase the availability of GATA-1 to the positively acting GATA element, thereby contributing to an increase in GATA-1-mediated transcription of the gene. To this end, we determined the methylation of the three CpG sites by bisulfate pyrosequencing in peripheral blood eosinophils, cord blood (CB)-derived eosinophils, PBMCs, and cell lines that vary in CCR3 mRNA expression. Our results demonstrated that methylation of CpG sites at the negatively acting GATA elements severely reduced GATA-1 binding and augmented transcription activity in vitro. In agreement, methylation of these CpG sites positively correlated with CCR3 mRNA expression in the primary cells and cell lines examined. Interestingly, methylation patterns of these three CpG sites in CB-derived eosinophils mostly resembled those in peripheral blood eosinophils. These results suggest that methylation of CpG sites at the GATA elements in the regulatory regions fine-tunes CCR3 transcription.

Lost sensibility of tyrosine aminotransferase to dexamethasone in human hepatoma cell line SMMC-7721 / 第二军医大学学报

Objective: To investigate the mechanism responsible for lost sensibility of tyrosine aminotransferase (TAT) to dexamethasone(Dex) in human hepatoma cell line SMMC-7721 through examining the cDNA sequence of TAT and the status of glucocorticoid receptor (GR) pathway. Methods: The TAT cDNA fragment containing the full length of coding sequence was amplified by reverse transcription polymerase chain reaction (RT-PCR) and was sequenced. The expression of TAT mRNA was determined by real-time quantitative PCR to observe the influence of Dex on expression of TAT mRNA in SMMC-7721 cells. The experiement with HepG2 cells was performed as the control. Reporter genes (GRE-tk-LUC and GRE-MMTV-CAT) were transiently transfected into SMMC-7721 cells by electroporation. The induction effieiencies of LUC and CAT genes expression by Dex were examined and compared between SMMC-7721 cells and HepG2 cells. Results: The results showed that there was a same-sense mutation (Gln576Gln) in TAT cDNA sequence. TAT mRNA could be induced by Dex, with the maximal induction level being 2.22-folds in SMMC-7721 cells, which was significantly lower than that in HepG2 cells (15.1-fold increase, P<0.01). Dex induced the expression of LUC and CAT genes in SMMC-7721 cells as well as the HepG2 cells. Conclusion: The induction efficiency of Dex for expression of TAT mRNA is decreased in SMMC-7721 cells, which might be due to the unchanged activity of TAT.

Estrogen modulates transactivations of SXR-mediated liver X receptor response element and CAR-mediated phenobarbital response element in HepG2 cells

The nuclear receptors, steroid and xenobiotic receptor (SXR) and constitutive androstane receptor (CAR) play important functions in mediating lipid and drug metabolism in the liver. The present study demonstrates modulatory actions of estrogen in transactivations of SXR-mediated liver X receptor response element (LXRE) and CAR-mediated phenobarbital response element (PBRU). When human estrogen receptor (hERalpha) and SXR were exogenously expressed, treatment with either rifampicin or corticosterone promoted significantly the SXR-mediated transactivation of LXRE reporter gene in HepG2. However, combined treatment with estrogen plus either rifampicin or corticosterone resulted in less than 50% of the mean values of the transactivation by rifampicin or corticosterone alone. Thus, it is suggested that estrogen may repress the SXR-mediated transactivation of LXRE via functional cross-talk between ER and SXR. The CAR-mediated transactivation of PBRU was stimulated by hERalpha in the absence of estrogen. However, the potentiation by CAR agonist, TCPOBOP, was significantly repressed by moxestrol in the presence of ER. Thus, ER may play both stimulatory and inhibitory roles in modulating CAR-mediated transactivation of PBRU depending on the presence of their ligands. In summary, this study demonstrates that estrogen modulates transcriptional activity of SXR and CAR in mediating transactivation of LXRE and PBRU, respectively, of the nuclear receptor target genes through functional cross-talk between ER and the corresponding nuclear receptors.

Difference in the Transcriptional Activity of the Interleukin-4 Promoter Haplotypes / 소아과

PURPOSE: Interleukin-4(IL-4) is a critical component of the Th2 cytokine pathway and contributes to severity of respiratory syncytial virus(RSV) bronchiolitis. Previous studies observed an association between severe RSV bronchiolitis in Korean children with a common haplotype of the IL4 promoter. This study was performed to investigate functional differences of the variant IL4 promoter haplotypes. METHODS: Genomic DNA was obtained from 20 children from 6 to 48 months of age in the Department of Pediatrics, Seoul National University Bundang Hospital. The IL4 promoter spanning an 1.2 kb region was amplified and haplotype was determined by cloning and the PHASE reconstruction. Transcriptional activity of Jurkat T cells which were transfected with each IL4 haplotype were analyzed by use of luciferase assay. RESULTS: Three haplotypes of the IL4 promoter have been identified with the frequency of GCC(7 percent), TCC(17 percent), and TTT(76 percent). The TTT haplotype demonstrated the highest luciferase values in both unstimulated and PMA-stimulated Jurkat T cells. Increases in transcriptional activity compared to GCC have been shown in TTT(5.3 fold higher) followed by TCC(4.2 fold higher) in unstimulated Jurkat T cells. CONCLUSION: We provided evidence that increased transcriptional activity of the TTT haplotype of the IL4 promoter, which has previously been over-represented in Korean children with severe RSV bronchiolitis. Therefore, IL-4 could play a potential role in the pathogenesis of RSV infection, possibly via an altered transcriptional activity of the different IL4 haplotypes.

Bcl-2-associated athanogene 1 regulates the glucocorticoid receptor activity in rat alveolar macrophages / 医学研究生学报

Objective: To investigate the expression changes of Bcl-2-associated athanogene 1(BAG-1) and its regulatory effect on the glucocorticoid receptor(GR) activity in rat alveolar macrophages in conditions of cell inflammation and glucocorticoid therapy.Methods: The expression changes of BAG-1 were detected by Western blot after lipopolysaccharide(LPS) and Dexamethasone(Dex) treatment of rat alveolar macrophages(AMs),the interaction between BAG-1 and GR determined by immune coprecipitation experiment,and the transcriptional activation of GR measured by relative luciferase activity assay.Results:After LPS and Dex treatment,the expression of BAG-1L in total protein increased but that of BAG-1S remained changed,BAG-1L rather than BAG-1S was detected in nuclear protein and its expression increased gradually within 24 hours,the interaction between BAG-1L and GR was observed in nucleoli,and the transcriptional activation of GR decreased,with a negative correlation between BAG-1L expression and GR activity.Conclusion:LPS and Dex acting on rat alveolar macrophages,the expression of BAG-1L increases,which,coupled with GR,translocates into nucleoli and inhibits GR activity.This might be the important mechanism that underlies glucocorticoid resistance in inflammation.

Investigations of glucocorticoid receptor mutant without ligand binding domain / 医学研究生学报

Objective:To construct expression vector of human glucocorticoid receptor mutant.Methods:cDNA sequence of human glucocorticoid receptor mutant having no LBD was amplificated through RT-nested PCR,PCR product was directionally cloned to pEGFP-N2 plasmid vector,and recombinant plasmids were screened through sequencing.Expressions of recombinant plasmids in human macrophage cell line U937 were observed through fluorescence microscope.Transcriptional activation activity of variant was evaluated through methods of relative activity of luciferase.Results:The 1 601 bp length cDNA was obtained,and result of sequencing confirmed the cloned cDNA sequence is completely coincidence with that of glucocorticoid receptor in Genebank.Expression products of recombinant plasmid mainly located in nucleus.Transcriptional activation activity incresed after recombinant plasmid transfected.Conclusion:Expression vector of glucocorticoid receptor mutant was constructed successfully,which has transcriptional activation activity independent of glucocorticoid.

Regulation of nitric oxide on glucocorticoid receptor function in rat alveolar macrophages treated by LPS in vitro / 第三军医大学学报

Objective To investigate the effects of nitric oxide donor (SNP) on glucocorticoid receptor function in condition of cell inflammation. Methods After fluorescence expression plasmid pGFP-GR transfected rat alveolar macrophges (AMs), nuclear translocation of GFP-GR following to lipopolysaccharide (LPS) and SNP treatment was observed through fluorescence microscope. The transcriptional activation activity of GR was evaluated by the method of relative activity of luciferase. Electrophoretic mobility shift assays (EMSA) were used to measure the activity of NF-?B. Results GFP-GR showed nuclear translocation in 2 h after nitric oxide donor (500 ?mol/L SNP) treatment, and the transcriptional activation activity of GR increased and the activity of NF-?B decreased remarkedly. The phenomena of depressed activity of NF-?B disappeared after the addition of GR special antagonism RU486. Conclusion Nitric oxide donor (500 ?mol/L SNP) exerts anti-inflammatory effect through GR activation in condition of cell inflammation.

Transcriptional activation function of a new protein-XTP11 in yeast cells / 解放军医学杂志

Objective To construct the yeast expression vector of a new gene transactivated by hepatitis B virus X protein (XTP11), and to explore the feasibility of cloning the hepatocyte proteins interacting with XTP11 protein by yeast two hybrid system. Methods The XTP11 gene was amplified by polymerase chain reaction (PCR) with specific primers, and the amplified fragment was subcloned into the Nco I/BamH I sites (5′ ends) of yeast expression vector pGBKT7,which was named as pGBKT7(-)-XTP11 encoding fusion proteins of full length of XTP11 and DNA binding domain of yeast protein GAL4. The pGBKT7 (-)-XTP11 plasmid was transformed in the yeast cells AH109 and the expression of XTP11 protein in yeast cells was detected by Western blotting assay. Then the yeast cells were plated on synthetic dropout nutrient medium (SD/-Trp and SD/-Trp-His-Ade) containing X-?-gal, and their autonomous activation was tested. Results The yeast expression vector of XTP11 gene was constructed and the fusion protein in yeast cells was examined. The yeast cells transformed with pGBKT7-XTP11 plasmid could grew well on both of the media, and turned blue on medium containing X-?-gal for the production X-?-galactosidase. This phenomenon suggested that XTP11 protein acted to substitute the functional yeast protein GAL4 activation domain (AD) to activate transcription of reporter genes (ADE2, HIS3, MEL1 and LacZ). Conclusion The XTP11 protein fused to the GAL4 DNA-binding domain functioned as a transcriptional activation domain in yeast, and the transcriptional activation function of XTP11 protein in yeast might restrain researchers to use yeast two hybrid system to clone hepatocyte proteins interacting with XTP11 protein.

Lost sensibility of tyrosine aminotransferase to dexamethasone in human hepatoma cell line SMMC-7721 / 第二军医大学学报

Objective:To investigate the mechanism responsible for lost sensibility of tyrosine aminotransferase(TAT)to dexam- ethasone(Dex)in human hepatoma cell line SMMC-7721 through examining the cDNA sequence of TAT and the status of glucocorticoid receptor(GR)pathway.Methods:The TAT cDNA fragment containing the full length of coding sequence was amplified by reverse transcription-polymerase chain reaction(RT-PCR)and was sequenced.The expression of TAT mRNA was determined by real-time quantitative PCR to observe the influence of Dex on expression of TAT mRNA in SMMC-7721 cells.The experiement with HepG2 cells was performed as the control.Reporter genes(GRE-tk-LUC and GRE-MMTV-CAT)were transiently transfected into SMMC-7721 cells by electroporation.The induction efficiencies of LUC and CAT genes expression by Dex were examined and compared between SMMC-7721 cells and HepG2 cells.Results:The results showed that there was a same-sense mutation(Gln576Gln)in TAT cDNA se- quence.TAT mRNA could be induced by Dex,with the maximal induction level being 2.22-folds in SMMC-7721 cells,which was signifi- cantly lower than that in HepG2 cells(15.1-fold increase,P