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1.
Front Immunol ; 14: 1233514, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37818377

RESUMO

Psoriasis is a chronic inflammatory skin disease characterized by hyperplasia of keratinocytes and immune cell infiltration. The IL-17-producing T cells play a key role in psoriasis pathogenesis, while regulatory T (Treg) cells are diminished during psoriatic inflammation. Current psoriasis treatments largely focus on IL-17 and IL-23, however, few studies have explored therapeutic drugs targeting an increase of Treg cells to control immune homeostasis. In this study, we investigated the effects of a cytotoxic T lymphocyte antigen-4 (CTLA-4) signaling peptide (dNP2-ctCTLA-4) in Th17, Tc17, γδ T cells, Treg cells in vitro and a mouse model of psoriasis. Treatment with dNP2-ctCTLA-4 peptide showed a significant reduction of psoriatic skin inflammation with increased Treg cell proportion and reduced IL-17 production by T cells, indicating a potential role in modulating psoriatic skin disease. We compared dNP2-ctCTLA-4 with CTLA-4-Ig and found that only dNP2-ctCTLA-4 ameliorated the psoriasis progression, with increased Treg cells and inhibited IL-17 production from γδ T cells. In vitro experiments using a T cell-antigen presenting cell co-culture system demonstrated the distinct mechanisms of dNP2-ctCTLA-4 compared to CTLA-4-Ig in the induction of Treg cells. These findings highlight the therapeutic potential of dNP2-ctCTLA-4 peptide in psoriasis by augmenting Treg/Teff ratio, offering a new approach to modulating the disease.


Assuntos
Dermatite , Psoríase , Camundongos , Animais , Linfócitos T Reguladores/patologia , Interleucina-17 , Antígeno CTLA-4 , Abatacepte/uso terapêutico , Inflamação/patologia
2.
ACS Appl Mater Interfaces ; 15(26): 31765-31775, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37338193

RESUMO

Metalizing three-dimensional (3D)-printed polymers has been spotlighted in the field of manufacturing high-end and customized electrical components. Conventional metalization approaches that rely on the electroless plating (ELP) process typically require the use of noble metal-based catalysts or involve multistep processes, limiting their practical applications. Herein, we propose a straightforward yet effective approach to manufacture 3D-printed polymers with conductive metal layers through a thiol-mediated ELP process without involving an additional catalytic activation process. A photocurable ternary resin based on thiol-ene-acrylate monomers was precisely designed to induce excess thiol moieties on the surface of 3D-printed structures. These exposed thiol moieties served as active sites for metal ion complexion via strong metal-sulfur bonds, allowing the deposition of metal layers on the 3D-printed polymers through the ELP. Diverse metal layers, including Cu, Ag, and NiP, could be deposited onto virtually any 3D-printed structures with high uniformity and adhesion stability. To highlight the potential application of our approach, we fabricated fully functional glucose sensors through the deposition of the Cu layer on 3D-printed electrode models, and these sensors displayed excellent nonenzymatic glucose sensing performance. The proposed approach offers great insights for designing functional metallic structures and opens up new avenues for manufacturing lightweight, customized electrical components.

3.
Polymers (Basel) ; 12(2)2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32059393

RESUMO

For the immediate detection of gaseous strong acids, it is advantageous to employ colorimetric textile sensors based on halochromic dyes. Thus, a rhodamine dye with superior pH sensitivity and high thermal stability was synthesized and incorporated in nylon 6 and polyester fabrics to fabricate textile sensors through dyeing and printing methods. The spectral properties and solubility of the dye were examined; sensitivity to acidic gas as well as durability and reversibility of the fabricated textile sensors were investigated. Both dyed and printed sensors exhibited a high reaction rate and distinctive color change under the acidic condition owing to the high pH sensitivity of the dye. In addition, both sensors have outstanding durability and reversibility after washing and drying.

4.
ACS Appl Mater Interfaces ; 11(21): 19363-19371, 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31062579

RESUMO

Sensitive and deformable chemical sensors manufactured by a low-cost process are promising as they are disposable, can be applied on curved, complex structures, and provide environmental information to users. Although many nanomaterial-based flexible sensors have been suggested to meet these demands, their limited chemical sensitivity and mechanical flexibility pose challenges. Here, a highly deformable chemical sensor is reported with improved sensitivity that integrates multiwalled carbon nanotubes (CNTs) and nanolayered transition metal dichalcogenides (TMDCs) on cellulose paper. Liquid dispersions of CNTs and TMDCs are absorbed and dried on porous cellulose for sensor fabrication, which is simple, scalable, rapid, and inexpensive. The cellulose substrate enables reversible three-dimensional folding and unfolding, bending down to 0.25 mm, and twisting up to 1800° (∼628.4 rad m-1) without degradation, and the CNTs maintain a percolation network and simultaneously provide gas reactivity. Functionalization of CNTs with TMDCs (WS2 or MoS2) greatly improves the sensing response upon exposure to NO2 molecules by more than 150%, and the sensor can also selectively detect NO2 over diverse reducing vapors. The measured NO2 sensitivity is 4.57% ppm-1, which is much higher than that of previous paper-based sensors. Our sensor can stably and sensitively detect the gas even under severe deformation such as heavy folding and crumpling. Hybrid integration of CNTs and TMDCs on cellulose paper may also be used to detect other harmful gases and can be applicable in low-cost portable devices that require reliable deformability.

5.
BMC Genomics ; 19(1): 387, 2018 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-29792157

RESUMO

BACKGROUND: Transposon-mediated, non-viral gene delivery is a powerful tool for generating stable cell lines and transgenic animals. However, as multi-copy insertion is the preferred integration pattern, there is the potential for uncontrolled changes in endogenous gene expression and detrimental effects in cells or animals. Our group has previously reported on the generation of several transgenic cattle by using microinjection of the Sleeping Beauty (SB) and PiggyBac (PB) transposons and seeks to explore the long-term effects of this technology on cattle. RESULTS: Transgenic cattle, one female (SNU-SB-1) and one male (SNU-PB-1), reached over 36 months of age with no significant health issues and normal blood parameters. The detection of transgene integration and fluorescent signal in oocytes and sperm suggested the capacity for germline transmission in both of the founder animals. After natural breeding, the founder transgenic cow delivered a male calf and secreted milk containing fluorescent transgenic proteins. The calf expressed green fluorescent protein in primary cells from ear skin, with no significant change in overall genomic stability and blood parameters. Three sites of transgene integration were identified by next-generation sequencing of the calf's genome. CONCLUSIONS: Overall, these data demonstrate that transposon-mediated transgenesis can be applied to cattle without being detrimental to their long-term genomic stability or general health. We further suggest that this technology may be usefully applied in other fields, such as the generation of transgenic animal models.


Assuntos
Técnicas de Transferência de Genes , Saúde , Óvulo/metabolismo , Espermatozoides/metabolismo , Transposases/genética , Animais , Animais Geneticamente Modificados , Bovinos , Feminino , Masculino , Transgenes/genética , Sequenciamento Completo do Genoma
6.
Plant Cell Physiol ; 54(10): 1620-34, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23921992

RESUMO

Brassinosteroids (BRs) activate the BRI1 and BAK1/SERK3 membrane receptor complex, which leads to a wide range of changes in gene expression, plant growth and development. As an initial step to elucidate additional roles of BAK1, we cloned a BAK1-binding protein, BAK1-Associating Receptor-Like Kinase 1 (BARK1), and characterized its gene expression and root phenotypes. BARK1 is a putative membrane LRR-RLK (leucine-rich repeat receptor-like kinase) protein that specifically binds to BAK1 and its homologs. Careful examination of BARK1 expression using transgenic plants expressing a green fluorescent protein (GFP) reporter under the control of the native BARK1 promoter (BARK1p::GFP) revealed that this gene is ubiquitously expressed in most plant tissues, and shows especially strong expression in the xylem vasculature of primary and lateral roots as well as in mature pollen. Interestingly, the expression of the BARK1 gene was increased in the BR biosynthetic loss-of-function mutant, det2, and a loss-of-function mutant of BR signaling, bak1-3. In contrast, this gene was down-regulated in the bzr1-1D plant, which is a BR signal gain-of-function mutant. BARK1-overexpressing transgenic plants clearly enhanced primary root growth in a dose-dependent manner, and their roots were hypersensitive to BR-induced root growth inhibition. In addition, both the number and density of lateral roots were dramatically increased in the BARK1 transgenic plants in a dose-dependent manner. Together with observations that ARF (AUXIN RESPONSE FACTOR) genes are up-regulated in the BARK1 overexpressor, we suggest that the BARK1 overexpressor phenotype with more lateral roots is partly due to the increased expression of ARF genes in this genetic background. In conclusion, BAK1-interacting BARK1 protein may be involved in BR-mediated plant growth and development such as in lateral roots via auxin regulation.


Assuntos
Proteínas de Arabidopsis/genética , Brassinosteroides/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Proteínas Serina-Treonina Quinases/genética , Sequência de Aminoácidos , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/classificação , Proteínas de Arabidopsis/metabolismo , Western Blotting , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Microscopia Confocal , Dados de Sequência Molecular , Fenótipo , Filogenia , Reguladores de Crescimento de Plantas/farmacologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
7.
Korean J Fam Med ; 34(2): 90-7, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23560207

RESUMO

BACKGROUND: The importance of communication between patients and physicians has been proven in many previous studies. The authors analyzed the effect of interview skill education through videotapes which recorded students' interviews with real patients in the outpatient department of family medicine. METHODS: This study was conducted with all students who chose the elective course of family medicine and one randomly selected student every week from an 'infectious internal medicine' class at Dongguk University Ilsan Hospital during the period from December 2008 to March 2011. All students performed a preliminary examination of a new patient at the outpatient department of family medicine. All consultations were videotaped. Feedback to the student was given on the same day by viewing the videotape together. After feedback, all students performed another preliminary examination of one new patient at the department of family medicine the same week. Three family medicine residents scored all videotapes using 10-item interview skill checklists. Many parts of the checklists were modified using the Arizona Clinical Interview Rating Scales. RESULTS: Thirty-three students participated. Of 10 items, nine showed increased scores after feedback. There was a significant change in four items after feedback: 'type of question' (before 2.36 ± 0.60, after 2.73 ± 0.72), 'timeline' (before 2.82 ± 0.68, after 3.18 ± 0.73), 'positive verbal reinforcement' (before 2.24 ± 0.56, after 2.61 ± 0.90), and the total score (before 21.70 ± 2.62, after 23.39 ± 3.13) (P < 0.05). CONCLUSION: Giving feedback to medical school students on medical interview skills using videotapes of students' preliminary consultations with real patients in outpatient settings, was effective in improving the interview areas of 'type of question,' 'timeline,' 'positive verbal reinforcement,' and the total interview scores.

8.
J Exp Bot ; 64(5): 1153-65, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23183258

RESUMO

During plant embryogenesis, the apical-basal axis is established and both the shoot apical meristem (SAM) and the root apical meristem (RAM) are formed. In both meristems, there are slowly dividing cells which control the differentiation of their surrounding cells called the organizing centre (OC) and the quiescent centre (QC) in the shoot and root, respectively. These centres with their surrounding initial cells form a 'stem cell niche'. The initial cells eventually differentiate into various plant tissues, giving rise to plant organs such as lateral shoots, flowers, leaves, and lateral roots. Plant hormones are important factors involved in the balance between cell division and differentiation such that plant growth and development are tightly controlled in space and time. No single hormone acts by itself in regulating the meristematic activity in the root meristem. Division and differentiation are controlled by interactions between several hormones. Intensive research on plant stem cells has focused on how cell division is regulated to form specific plant organs and tissues, how differentiation is controlled, and how stem cell fate is coordinated. In this review, recent knowledge pertaining to the role of plant hormones in maintaining root stem cells including the QC is summarized and discussed. Furthermore, we suggest diverse approaches to answering the main question of how root stem cells are regulated and maintained by plant hormones.


Assuntos
Reguladores de Crescimento de Plantas/farmacologia , Raízes de Plantas/citologia , Células-Tronco/citologia , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo
9.
Plant Physiol ; 159(3): 1001-12, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22582133

RESUMO

Sugars play important roles in many aspects of plant growth and development, acting as both energy sources and signaling molecules. With the successful use of genetic approaches, the molecular components involved in sugar signaling have been identified and their regulatory roles in the pathways have been elucidated. Here, we describe novel mutants of Arabidopsis (Arabidopsis thaliana), named glucose insensitive growth (gig), identified by their insensitivity to high-glucose (Glc)-induced growth inhibition. The gig mutant displayed retarded growth under normal growth conditions and also showed alterations in the expression of Glc-responsive genes under high-Glc conditions. Our molecular identification reveals that GIG encodes the plastidial copper (Cu) transporter PAA1 (for P(1B)-type ATPase 1). Interestingly, double mutant analysis indicated that in high Glc, gig is epistatic to both hexokinase1 (hxk1) and aba insensitive4 (abi4), major regulators in sugar and retrograde signaling. Under high-Glc conditions, the addition of Cu had no effect on the recovery of gig/paa1 to the wild type, whereas exogenous Cu feeding could suppress its phenotype under normal growth conditions. The expression of GIG/PAA1 was also altered by mutations in the nuclear factors HXK1, ABI3, and ABI4 in high Glc. Furthermore, a transient expression assay revealed the interaction between ABI4 and the GIG/PAA1 promoter, suggesting that ABI4 actively regulates the transcription of GIG/PAA1, likely binding to the CCAC/ACGT core element of the GIG/PAA1 promoter. Our findings indicate that the plastidial Cu transporter PAA1, which is essential for plastid function and/or activity, plays an important role in bidirectional communication between the plastid and the nucleus in high Glc.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , ATPases de Cloroplastos Translocadoras de Prótons/metabolismo , Cobre/metabolismo , Glucose/farmacologia , Mutação/genética , Plastídeos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , ATPases de Cloroplastos Translocadoras de Prótons/genética , Epistasia Genética/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas/genética , Teste de Complementação Genética , Loci Gênicos/genética , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Modelos Biológicos , Plastídeos/efeitos dos fármacos , Fatores de Transcrição/metabolismo
10.
J Exp Bot ; 63(5): 1823-33, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22170941

RESUMO

A metabolic study revealed that 28-norcastasterone in Arabidopsis is synthesized from cholesterol via the late C-6 oxidation pathway. On the other hand, the early C-6 oxidation pathway was found to be interrupted because cholestanol is converted to 6-oxocholestanol, but further metabolism to 28-norcathasterone was not observed. The 6-oxoBRs were found to have been produced from the respective 6-deoxoBRs administered to the enzyme solution, thus indicating that these 6-oxoBRs are supplied from the late C-6 oxidation pathway. Heterologously expressed CYP85A1 and CYP85A2 in yeast catalysed this C-6 oxidation, with CYP85A2 being much more efficient than CYP85A1. Abnormal growth of det2 and dwf4 was restored via the application of 28-norcastasterone and closer precursors. Furthermore, det2 and dwf4 could not convert cholesterol to cholestanol and cholestanol to 6-deoxo-28-norcathasterone, respectively. It is, therefore, most likely that the same enzyme system is operant in the synthesis of both 28-norcastasterone and castasterone. In the presence of S-adenosyl-L-methionine, the cell-free enzyme extract catalysed the C-24 methylation of 28-norcastasterone to castasterone, although the conversion rates of 28-norteasterone to teasterone and 28-nortyphasterol to typhasterol were much lower; this suggests that 28-norcastasterone is the primary precursor for the generation of C(28)-BRs from C(27)-BRs.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Colestanóis/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Colesterol/metabolismo , Mutação , Oxirredução , Saccharomyces/genética , Saccharomyces/metabolismo , Transgenes
11.
J Craniofac Surg ; 22(6): 2238-40, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22134257

RESUMO

Ankyloglossia or tongue-tie is a disease in which the tongue has a mobility disorder because the lingual frenulum is short and tight, and as a result, the tongue tip is tied up. It may be asymptomatic or may cause various problems such as articulation disorder. Surgical treatment is required in many of the patients, and conventional methods release only the mucosal layer of the frenulum. However, conventional method alone is not as effective; therefore, the authors studied the addition of a partial myotomy of the genioglossus muscle along with mucosal layer release for treatment. The authors performed the surgery on 106 patients from 2005 to 2010, and during the surgery, the mucosal layer was released through Z-plasty after myotomy was performed on the contracted genioglossus muscle. During the follow-up, none of the patients showed signs and symptoms of tongue mobility impairment or articulation disorder caused by the partial myotomy of the genioglossus muscle, and a satisfactory outcome was obtained in achieving mobility of the tongue tip. Because tongue mobility disorder in ankyloglossia is accompanied by the contracture and shortening of the genioglossus muscle, an improved outcome is expected in the projection and mobility of the tongue tip from the combined application of conventional Z-plasty and genioglossus muscle release.


Assuntos
Freio Lingual/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Doenças da Língua/cirurgia , Língua/cirurgia , Criança , Pré-Escolar , Disartria/etiologia , Feminino , Humanos , Lactente , Freio Lingual/anormalidades , Masculino , Retalhos Cirúrgicos , Língua/anormalidades , Resultado do Tratamento
12.
Plant Physiol Biochem ; 49(8): 909-16, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21696975

RESUMO

The effects of ascorbic acid (AA) and dehydroascorbic acid (DHA), one of products of the disproportionation of monodehydroascorbate (MDHA) by AA oxidase (AAO, EC 1.10.3.3), on the gravitropic curvature of Arabidopsis roots were characterized by biochemical and genetic approaches. Exogenously applied AA and DHA both stimulated root gravitropic responses in a concentration-dependent fashion. AA also changed the Indole-3-acetic acid (IAA) distribution in the roots after gravistimulation. In an effort to determine the relationship between AA and DHA in the gravitropic response, changes in the amount of reduced AA were evaluated in Arabidopsis under a variety of conditions. The expression level of an AAO gene (AAO1) was increased upon gravistimulation. Brassinolide (BL), indole-3-acetic acid (IAA), and AA also increased the transcript levels of this gene. Root elongation and the gravitropic response were both suppressed in the AA biosynthesis mutant, vtc1, which has a greatly reduced level of total AA. Furthermore, the line of AAO double mutants (aao1-1 X aao3-1, 41-21) showed a reduced gravitropic response and reduced root elongation. Taken together, the results of this study imply that both AA and DHA help to determine the redox environment for the root gravitropic response, but DHA, rather than AA, is a major player in the regulation of the gravitropic response mediated by AA in the roots of Arabidopsis thaliana.


Assuntos
Arabidopsis/fisiologia , Ácido Ascórbico/farmacologia , Ácido Desidroascórbico/farmacologia , Gravitropismo/fisiologia , Raízes de Plantas/fisiologia , Aldeído Oxidase/efeitos dos fármacos , Aldeído Oxidase/genética , Aldeído Oxidase/metabolismo , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ácido Ascórbico/metabolismo , Brassinosteroides/metabolismo , Ácido Desidroascórbico/análogos & derivados , Ácido Desidroascórbico/metabolismo , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Mutação , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Raízes de Plantas/efeitos dos fármacos , Esteroides Heterocíclicos/metabolismo
13.
J Craniofac Surg ; 21(5): 1639-41, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20856067

RESUMO

Cutaneous focal mucinosis is a type of degenerative-inflammatory dermal mucinoses characterized with asymptomatic, single, dermal mucin deposition. Because of its rarity, it is often mistaken clinically for other disorders such as sebaceous cyst, fibroma, myxoma, and xanthoma. In this study, we will discuss a case of cutaneous focal mucinosis arising from the chin of a 27-year-old man.


Assuntos
Queixo , Mucinoses/diagnóstico , Mucinoses/cirurgia , Dermatopatias/diagnóstico , Dermatopatias/cirurgia , Adulto , Meios de Contraste , Diagnóstico Diferencial , Humanos , Masculino , Tomografia Computadorizada por Raios X
14.
Nucleic Acids Res ; 38(4): 1382-91, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19969544

RESUMO

MicroRNA (miR)390 cleaves the non-coding TAS3 precursor RNA for the production of tasiRNA-ARF, a group of an endogenous trans-acting small-interfering RNAs which cleave the transcripts of auxin response factor (ARF) 3/4. miR390-cleaved TAS3 RNA is polymerized and diced into tasiRNA-ARF by RNA-dependent RNA polymerase6 (RDR6) and Dicer-like4 (DCL4), respectively. tasiRNA-ARF-dependent post-transcriptional gene silencing (PTGS) of ARF3/4 is involved in auxin-mediated polarity establishment in the development of aerial lateral organs, such as leaf and flower. To understand how auxin regulates ARF4 expression, we examined auxin responsiveness of miR390 expression, which comprises a regulatory step for the biogenesis pathway of tasiRNA-ARF (the tasiRNA-ARF pathway), in Arabidopsis thaliana lateral root (LR) development. The results of this study provide evidence that miR390 expression is sensitive to TIR1-dependent transcriptional regulation and auxin concentration, and also that mutual negative-regulation between the tasiRNA-ARF pathway and ARF4 modulates the spatiotemporal expression of ARF4. We propose that, together with auxin concentration sensing through miR390 transcription, the tasiRNA-ARF pathway mediates the auxin response and ARF4-mediated LR developmental processes.


Assuntos
Arabidopsis/genética , Ácidos Indolacéticos/farmacologia , MicroRNAs/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Raízes de Plantas/crescimento & desenvolvimento , RNA Interferente Pequeno/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Interferência de RNA
15.
Nucleic Acids Res ; 36(4): 1220-6, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18160413

RESUMO

RNA-dependent RNA polymerase 6 (RDR6) catalyses dsRNA synthesis for post-transcriptional gene silencing (PTGS)-associated amplification and the generation of endogeneous siRNAs involved in developmental determinations or stress responses. The functional importance of RDR6 in PTGS led us to examine its connection to the cellular regulatory network by analyzing the hormonal responses of RDR6 gene expression in a cultured cell system. Delivery of dsRNA, prepared in vitro, into cultured rice (Oryza sativa cv. Japonica Dongjin) cells successfully silenced the target isocitrate lyase (ICL) transcripts. Silencing was transient in the absence of abscisic acid (ABA), while it became persistent in the presence of ABA in growth medium. A transcription assay of the OsRDR6 promoter showed that it was positively regulated by ABA. OsRDR6-dependent siRNA(ICL) generation was also significantly up-regulated by ABA. The results showed that, among the five rice OsRDR isogenes, only OsRDR6 was responsible for the observed ABA-mediated amplification and silencing of ICL transcripts. We propose that ABA modulates PTGS through the transcriptional control of the OsRDR6 gene.


Assuntos
Ácido Abscísico/farmacologia , Regulação da Expressão Gênica de Plantas , Oryza/genética , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/genética , Interferência de RNA , RNA Polimerase Dependente de RNA/genética , Isocitrato Liase/biossíntese , Isocitrato Liase/genética , Oryza/efeitos dos fármacos , Oryza/enzimologia , Proteínas de Plantas/biossíntese , RNA Polimerase Dependente de RNA/biossíntese
16.
Nucleic Acids Res ; 34(6): 1892-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16598073

RESUMO

MicroRNA167 (miR167) was shown to cleave auxin responsive factor 8 (ARF8) mRNA in cultured rice cells. MiR167 level was found to be controlled by the presence of auxin in the growth medium. When cells grew in auxin-free medium, miR167 level decreased, resulting in an increase in the level of ARF8 mRNA. Cells growing in the normal growth medium containing auxin showed a reversed trend. It was also shown that expression of OsGH3-2, an rice IAA-conjugating enzyme, was positively regulated by ARF8. Delivery of synthesized miR167 into cells led to decrease of both ARF8 mRNA and OsGH3-2 mRNA. This study provides an evidence in which the exogeneous auxin signal is transduced to OsGH3-2 through miR167 and ARF8 in sequence. This proposed auxin signal transduction pathway, auxin-miR167-ARF8-OsGH3-2, could be, in conjunction with the other microRNA-mediated auxin signals, an important one for responding to exogeneous auxin and for determining the cellular free auxin level which guides appropriate auxin responses.


Assuntos
Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/farmacologia , MicroRNAs/metabolismo , Oryza/genética , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/genética , Células Cultivadas , Regulação Enzimológica da Expressão Gênica , Oryza/citologia , Oryza/metabolismo , Proteínas de Plantas/metabolismo , RNA Mensageiro/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
17.
FEBS Lett ; 566(1-3): 307-10, 2004 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-15147914

RESUMO

We have used cationic oligopeptide polyarginine-12mer (POA) to deliver double-stranded RNA (dsRNA), prepared in vitro, to tobacco (Nicotiana tabacum) suspension cells. POA interacts electrostatically with dsRNA to form a complex. When dsRNA for the GUS or NPTII gene was delivered into cells carrying the same genes, the corresponding mRNA was degraded. Using RNase protection assay we were able to detect 21-bp small interfering RNA in dsRNA/POA-treated cells. These results demonstrate that POA can be used to deliver dsRNA to induce post-transcriptional gene silencing in plant cells.


Assuntos
Nicotiana/genética , Oligopeptídeos/química , Peptídeos/química , Interferência de RNA , RNA de Cadeia Dupla/química , RNA de Cadeia Dupla/genética , Northern Blotting , Cátions , Células Cultivadas , Genes de Plantas/genética , Brotos de Planta/citologia , Plantas Geneticamente Modificadas/citologia , RNA de Cadeia Dupla/metabolismo , RNA Mensageiro/genética , RNA Interferente Pequeno/biossíntese , Nicotiana/citologia , Nicotiana/ultraestrutura
18.
Biochim Biophys Acta ; 1640(2-3): 129-36, 2003 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-12729922

RESUMO

Certain peptides containing high percentage of cationic amino acids are known to efficiently translocate through the cell membrane. This principle was previously exploited for delivery of variety proteins. We had observed that various basic peptides of earlier studies, though not specifically use for gene delivery, contain DNA or RNA binding domains. In the present study, we reported on arginine peptides, which form DNA complexes that efficiently transfect various cell lines. The transfection abilities of the peptides were observed by green fluorescent protein (GFP) and beta-galactosidase gene expression in 293T, HeLa, Jurkat, and COS-7 cells. We found superior transfection activity of arginine peptides compared with commercially available efficient transfection agents. The expression of marker genes induced by arginine peptides was partially inhibited in the presence of heparan sulfate, chondroitin sulfate B and C, or both heparinase III and chondroitinase ABC. The transfection proficiency of these peptides was affected by endosomotropic reagent as well as low temperature (4 degrees C). Finally, we have investigated the potential of arginine peptides as a delivery agent for gene therapy, by attempting to deliver herpes simplex virus thymidine kinase (HSV-TK) gene into tumor cells. HSV-TK transfected tumor cells exhibited sensitivity to the antiviral drug ganciclovir (GCV), leading to cell death. Taken together, these data demonstrate that arginine peptide is proficient for transfection, indicating its potentially benefit to studies in gene therapy and gene delivery in a range of model organisms.


Assuntos
DNA/administração & dosagem , Terapia Genética/métodos , Peptídeos/administração & dosagem , Transfecção/métodos , Animais , Arginina , Transporte Biológico , Linhagem Celular , Humanos , Neoplasias/terapia , Proteoglicanas/fisiologia , Timidina Quinase/genética
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