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1.
Adv Sci (Weinh) ; 10(33): e2305096, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37845006

RESUMO

Despite advances in precision oncology, cancer remains a global public health issue. In this report, proof-of-principle evidence is presented that a cell-penetrable peptide (ACP52C) dissociates transcription factor CP2c complexes and induces apoptosis in most CP2c oncogene-addicted cancer cells through transcription activity-independent mechanisms. CP2cs dissociated from complexes directly interact with and degrade YY1, leading to apoptosis via the MDM2-p53 pathway. The liberated CP2cs also inhibit TDP2, causing intrinsic genome-wide DNA strand breaks and subsequent catastrophic DNA damage responses. These two mechanisms are independent of cancer driver mutations but are hindered by high MDM2 p60 expression. However, resistance to ACP52C mediated by MDM2 p60 can be sensitized by CASP2 inhibition. Additionally, derivatives of ACP52C conjugated with fatty acid alone or with a CASP2 inhibiting peptide show improved pharmacokinetics and reduced cancer burden, even in ACP52C-resistant cancers. This study enhances the understanding of ACP52C-induced cancer-specific apoptosis induction and supports the use of ACP52C in anticancer drug development.


Assuntos
Proteínas de Ligação a DNA , Neoplasias , Humanos , Proteínas de Ligação a DNA/genética , Neoplasias/genética , Mutações Sintéticas Letais , Medicina de Precisão , Fatores de Transcrição/genética , Peptídeos , Diester Fosfórico Hidrolases/genética
2.
Commun Biol ; 4(1): 544, 2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-33972689

RESUMO

Actin-Related Protein-Testis1 (ARP-T1)/ACTRT1 gene mutations cause the Bazex-Dupré-Christol Syndrome (BDCS) characterized by follicular atrophoderma, hypotrichosis, and basal cell cancer. Here, we report an ARP-T1 interactome (PXD016557) that includes proteins involved in ciliogenesis, endosomal recycling, and septin ring formation. In agreement, ARP-T1 localizes to the midbody during cytokinesis and the basal body of primary cilia in interphase. Tissue samples from ARP-T1-associated BDCS patients have reduced ciliary length. The severity of the shortened cilia significantly correlates with the ARP-T1 levels, which was further validated by ACTRT1 knockdown in culture cells. Thus, we propose that ARP-T1 participates in the regulation of cilia length and that ARP-T1-associated BDCS is a case of skin cancer with ciliopathy characteristics.


Assuntos
Carcinoma Basocelular/patologia , Cílios/patologia , Ciliopatias/patologia , Hipotricose/patologia , Queratinócitos/patologia , Proteínas dos Microfilamentos/metabolismo , Neoplasia de Células Basais/patologia , Neoplasias Cutâneas/patologia , Carcinoma Basocelular/genética , Carcinoma Basocelular/metabolismo , Cílios/metabolismo , Ciliopatias/genética , Ciliopatias/metabolismo , Humanos , Hipotricose/genética , Hipotricose/metabolismo , Queratinócitos/metabolismo , Proteínas dos Microfilamentos/genética , Mutação , Neoplasia de Células Basais/genética , Neoplasia de Células Basais/metabolismo , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo
3.
J Clin Med ; 9(11)2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33172126

RESUMO

This study was performed to evaluate the anticancer effects of tolerable doses of metformin with or without medroxyprogesterone (MPA) in endometrial cancer cells. Cell viability, cell invasion, and levels of matrix metallopeptidase (MMP) and transforming growth factor (TGF)-ß1 were analyzed using three human endometrial adenocarcinoma cell lines (Ishikawa, KLE, and uterine serous papillary cancer (USPC)) after treatment with different dose combinations of MPA and metformin. Combining metformin (0, 100, 1000 µM) and 10 µM MPA induced significantly decreased cell viability in a time- and dose-dependent manner in Ishikawa cells, but not in KLE and USPC cells. In KLE cells, metformin treatment alone significantly inhibited cell invasion in a dose-dependent manner. The inhibitory effect of metformin was reversed when 10 µM MPA was combined, which was significantly inhibited again after treatment of MMP-2/9 inhibitor and/or TGF-ß inhibitor. Changes of MMP-9 and TGF-ß1 according to combinations of MPA and metformin were similar to those of invasion in KLE cells. In conclusion, the anticancer effects of tolerable doses of metformin varied according to cell type and combinations with MPA. Anti-invasive effect of metformin in KLE cells was completely reversed by the addition of MPA; this might be associated with MMP-9 and TGF-ß1.

4.
Cell Cycle ; 18(21): 2954-2971, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31505996

RESUMO

In previous work, we established an equine induced pluripotent stem cell line (E-iPSCs) from equine adipose-derived stem cells (ASCs) using a lentiviral vector encoding four transcription factors: Oct4, Sox2, Klf4, and c-Myc. In the current study, we attempted to differentiate these established E-iPSCs into mesenchymal stem cells (MSCs) by serial passaging using MSC-defined media for stem cell expansion. Differentiation of the MSCs was confirmed by analyzing expression levels of the MSC surface markers CD44 and CD29, and the pluripotency markers Nanog and Oct4. Results indicated that the E-iPSC-derived MSCs (E-iPSC-MSCs) retained the characteristics of MSCs, including the ability to differentiate into chondrogenic, osteogenic, or myogenic lineages. E-iPSC-MSCs were rendered suitable for therapeutic use by inhibiting immune rejection through exposure to transforming growth factor beta 2 (TGF-ß2) in culture, which down-regulated the expression of major histocompatibility complex class I (MHC class I) proteins that cause immune rejection if they are incompatible with the MHC antigen of the recipient. We reported 16 cases of E-iPSC-MSC transplantations into injured horses with generally positive effects, such as reduced lameness and fraction lines. Our findings indicate that E-iPSC-MSCs can demonstrate MSC characteristics and be safely and practically used in the treatment of musculoskeletal injuries in horses.


Assuntos
Diferenciação Celular/fisiologia , Terapia Baseada em Transplante de Células e Tecidos/métodos , Rejeição de Enxerto/prevenção & controle , Células-Tronco Pluripotentes Induzidas/citologia , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/citologia , Adipócitos/citologia , Tecido Adiposo/citologia , Animais , Desenvolvimento Ósseo/fisiologia , Células Cultivadas , Condrócitos/citologia , Condrogênese/fisiologia , Rejeição de Enxerto/imunologia , Cavalos , Fator 4 Semelhante a Kruppel , Células Musculares/citologia , Desenvolvimento Muscular/fisiologia , Músculo Esquelético/lesões , Osteócitos/citologia , Fator de Crescimento Transformador beta2/metabolismo
5.
Cell Death Dis ; 9(11): 1092, 2018 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-30361642

RESUMO

Life-long regeneration of healthy muscle by cell transplantation is an ideal therapy for patients with degenerative muscle diseases. Yet, obtaining muscle stem cells from patients is very limited due to their exhaustion in disease condition. Thus, development of a method to obtain healthy myogenic stem cells is required. Here, we showed that the four transcription factors, Six1, Eya1, Esrrb, and Pax3, converts fibroblasts into induced myogenic stem cells (iMSCs). The iMSCs showed effective differentiation into multinucleated myotubes and also higher proliferation capacity than muscle derived stem cells both in vitro and in vivo. The iMSCs do not lose their proliferation capacity though the passaging number is increased. We further isolated CD106-negative and α7-integrin-positive iMSCs (sort-iMSCs) showing higher myogenic differentiation capacity than iMSCs. Moreover, genome-wide transcriptomic analysis of iMSCs and sort-iMSCs, followed by network analysis, revealed the genes and signaling pathways associated with enhanced proliferation and differentiation capacity of iMSCs and sort-iMSCs, respectively. The stably expandable iMSCs provide a new source for drug screening and muscle regenerative therapy for muscle wasting disease.


Assuntos
Reprogramação Celular , Fibroblastos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Mioblastos/metabolismo , Fatores de Transcrição/metabolismo , Animais , Antígenos CD/metabolismo , Pontos de Checagem do Ciclo Celular , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Distrofina/metabolismo , Feminino , Cadeias alfa de Integrinas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL/embriologia , Camundongos Endogâmicos mdx , Camundongos Nus , Desenvolvimento Muscular , Distrofias Musculares/terapia , Gravidez , RNA Mensageiro/genética , Transplante de Células-Tronco , Transplante Autólogo , Molécula 1 de Adesão de Célula Vascular/metabolismo
6.
Nat Med ; 23(10): 1226-1233, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28869610

RESUMO

Basal cell carcinoma (BCC), the most common human cancer, results from aberrant activation of the Hedgehog signaling pathway. Although most cases of BCC are sporadic, some forms are inherited, such as Bazex-Dupré-Christol syndrome (BDCS)-a cancer-prone genodermatosis with an X-linked, dominant inheritance pattern. We have identified mutations in the ACTRT1 gene, which encodes actin-related protein T1 (ARP-T1), in two of the six families with BDCS that were examined in this study. High-throughput sequencing in the four remaining families identified germline mutations in noncoding sequences surrounding ACTRT1. These mutations were located in transcribed sequences encoding enhancer RNAs (eRNAs) and were shown to impair enhancer activity and ACTRT1 expression. ARP-T1 was found to directly bind to the GLI1 promoter, thus inhibiting GLI1 expression, and loss of ARP-T1 led to activation of the Hedgehog pathway in individuals with BDCS. Moreover, exogenous expression of ACTRT1 reduced the in vitro and in vivo proliferation rates of cell lines with aberrant activation of the Hedgehog signaling pathway. In summary, our study identifies a disease mechanism in BCC involving mutations in regulatory noncoding elements and uncovers the tumor-suppressor properties of ACTRT1.


Assuntos
Carcinoma Basocelular/genética , Hipotricose/genética , Proteínas dos Microfilamentos/genética , Neoplasias Cutâneas/genética , Animais , Sistemas CRISPR-Cas , Imunoprecipitação da Cromatina , Elementos Facilitadores Genéticos/genética , Feminino , Perfilação da Expressão Gênica , Proteínas Hedgehog/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Camundongos , Camundongos Nus , Mutação , Transplante de Neoplasias , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Transdução de Sinais
7.
J Invest Dermatol ; 136(5): 905-911, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27017330

RESUMO

The homeodomain-only protein homeobox (HOPX) is the smallest known member of the homeodomain-containing protein family, atypically unable to bind DNA. HOPX is widely expressed in diverse tissues, where it is critically involved in the regulation of proliferation and differentiation. In human skin, HOPX controls epidermal formation through the regulation of late differentiation markers, and HOPX expression correlates with the level of differentiation in cutaneous pathologies. In mouse skin, Hopx was additionally identified as a lineage tracing marker of quiescent hair follicle stem cells. This review discusses current knowledge of HOPX structure and function in normal and pathological conditions.


Assuntos
Regulação Neoplásica da Expressão Gênica , Genes Homeobox/genética , Proteínas de Homeodomínio/genética , Neoplasias Cutâneas/genética , Animais , Diferenciação Celular/genética , Proliferação de Células/genética , Metilação de DNA , Humanos , Camundongos , Sensibilidade e Especificidade , Neoplasias Cutâneas/fisiopatologia , Células Tumorais Cultivadas
8.
Regen Med ; 6(6): 689-99, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22050521

RESUMO

AIMS: Dental tissue has been the focus of attention as an easily accessible postnatal tissue source of high-quality stem cells. Since the first report on the dental pulp stem cells (DPSCs) from permanent third molar teeth, stem cells from human exfoliated deciduous teeth (SHED) were identified as a population distinct from DPSCs. In this study, we compared DPSCs from supernumerary teeth and SHED in three age- and sex-matched patients. PATIENTS & METHODS: Dental samples were obtained from the three patients, who were 6 years old and male, with the parental consent of the three donors, and then isolated cells from dental pulp for comparative analysis between supernumerary DPSCs and SHED. RESULTS: Colony-forming unit fibroblast levels and the proliferation rate of supernumerary DPSCs were slightly lower than that of SHED. The expression of cell surface antigens in supernumerary DPSCs and SHED were almost identical. Cells were mainly expressing endogenous mesodermal and ectodermal lineage markers. Differentiation capacity to osteogenic, adipogenic and chondrogenic lineage was similar in the SHED and supernumerary DPSCs. Migration assay revealed that both supernumerary DPSCs and SHED rapidly migrated toward wounded areas. Supernumerary DPSCs were altered in cell growth after storage for 2 years. Specially, the population doubling time of supernumerary DPSCs increased while that of SHED remained nearly unchanged. CONCLUSION: Both supernumerary teeth and deciduous teeth share many characteristics, such as highly proliferative clonogenic cells with a similar immunophenotype to that of mesenchymal stem cells, although they are inferior to SHED for long-term banking. Our findings suggest that supernumerary teeth are also easily accessible and noninvasive sources of postnatal stem cells with multipotency and regenerative capacity.


Assuntos
Células-Tronco Mesenquimais/citologia , Esfoliação de Dente/patologia , Dente Decíduo/patologia , Dente Supranumerário/patologia , Diferenciação Celular , Proliferação de Células , Separação Celular , Células Cultivadas , Criança , Células Clonais , Análise Citogenética , Polpa Dentária/citologia , Humanos , Imunofenotipagem , Incisivo/citologia , Masculino , Cicatrização
9.
Cell Stem Cell ; 8(1): 106-18, 2011 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-21211785

RESUMO

Genomic stability is critical for the clinical use of human embryonic and induced pluripotent stem cells. We performed high-resolution SNP (single-nucleotide polymorphism) analysis on 186 pluripotent and 119 nonpluripotent samples. We report a higher frequency of subchromosomal copy number variations in pluripotent samples compared to nonpluripotent samples, with variations enriched in specific genomic regions. The distribution of these variations differed between hESCs and hiPSCs, characterized by large numbers of duplications found in a few hESC samples and moderate numbers of deletions distributed across many hiPSC samples. For hiPSCs, the reprogramming process was associated with deletions of tumor-suppressor genes, whereas time in culture was associated with duplications of oncogenic genes. We also observed duplications that arose during a differentiation protocol. Our results illustrate the dynamic nature of genomic abnormalities in pluripotent stem cells and the need for frequent genomic monitoring to assure phenotypic stability and clinical safety.


Assuntos
Proliferação de Células , Reprogramação Celular , Células-Tronco Embrionárias/citologia , Dosagem de Genes , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes/citologia , Diferenciação Celular , Células Cultivadas , Células-Tronco Embrionárias/metabolismo , Genoma Humano , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Fenótipo , Células-Tronco Pluripotentes/metabolismo
10.
Taehan Kanho Hakhoe Chi ; 37(5): 715-23, 2007 Aug.
Artigo em Coreano | MEDLINE | ID: mdl-17804938

RESUMO

PURPOSE: The purposes of this study were 1) to compare the contribution of demographic-behavioral variables and psychological variables in explaining the variance of depression, 2) identify the most important predictors of depression for Korean female adolescents. METHOD: The participants were 840 female adolescents. Data was collected through self-report questionnaires, which were constructed to include demographicbehavioral factors, self-esteem, hostility, hopelessness, and depression. Data was analyzed using the SPSS program. RESULT: Female adolescents' demographicbehavioral variables explained 17% of the variance in depression, and perceived physical health status, history of physical abuse, smoking, satisfaction of body weight, parental alcohol abuse, parental divorce, and history of suicidal attempt were the significant predictors of depression for female adolescents. Psychological variables explained 50% of the variance in depression, and self-esteem, hostility, and hopelessness were the significant predictors of depression for female adolescents. The significant predictors of depression among female adolescents' demographicbehavioral variables and psychological variables were self-esteem, hostility, hopelessness, perceived physical health status, parental alcohol problem, and history of physical abuse, explaining 52% of the variance in depression. CONCLUSION: In order to reduce depression in female adolescents, it is necessary to design an intervention program that emphasizes improving self-esteem while reducing hostility and hopelessness.


Assuntos
Depressão/psicologia , Psicologia do Adolescente , Adolescente , Análise de Variância , Demografia , Feminino , Hostilidade , Humanos , Coreia (Geográfico) , Solidão , Valor Preditivo dos Testes , Autoimagem , Inquéritos e Questionários
11.
J Gene Med ; 8(12): 1425-34, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17009340

RESUMO

BACKGROUND: Animal viruses such as enveloped virus carry multi-functional proteins in the virion that can mediate more than two distinct steps of a gene delivery process during the transfer of viral genome into host cells. We tested if the aspects of the viral gene delivery mechanism could be mimicked by forming composite formulae from multi-functional synthetic gene carriers having complementary action modes. METHODS: Polyethylenimine (PEI) was chosen as the component responsible for endosome escape and DNA condensation and KALA for cellular entry and DNA condensation. Compact DNA-carrier particles consisting of the core part where DNA chains were tightly condensed by PEI and the outer layer lined with KALA were formulated, characterized and compared with monolithic cationic formulae in terms of gene delivery efficiency and mechanism. RESULTS: High-level gene expression was observed when C2C12 cells were transfected with DNA that was first partially condensed with PEI and, then, fully with KALA. In these formulae KALA mediated enhanced cellular entry of DNA by facilitating endocytic vesicle formation, while PEI provided an effective endosomolytic capacity. An optimal PEI/KALA formula showed transfection efficiencies better than or comparable to the commercial cationic liposome in various cell types in culture and in vivo. CONCLUSIONS: Gene delivery by combining the membrane-active property of KALA with the endosomolytic activity of PEI can be more efficient than that by either of the properties alone. It appears that, in these formulae, the predominant role of KALA is to facilitate cellular entry of DNA by providing a fusogenic capability, rather than an endosomolytic activity.


Assuntos
Proteínas de Ligação a DNA/genética , DNA/química , Técnicas de Transferência de Genes , Vetores Genéticos , Substâncias Macromoleculares/química , Peptídeos/genética , Polietilenoimina , Animais , Linhagem Celular , Células Cultivadas , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL
12.
J Sch Health ; 76(5): 181-8, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16635202

RESUMO

The purpose of this study was to examine the evidence to determine if there are gender differences in suicidal ideation of adolescents. This study examined the main effect of risk factors from 5 domains and protective factors from 1 domain in relation to suicidal ideation by gender and identified the most important predictors of suicidal ideation for males (N = 654) and females (N = 658). This study was a cross-sectional survey, and data were collected through self-report questionnaires. In the univariate analysis, especially, risk factors from behavioral variables and psychosocial-environmental variables appeared to be gender skewed. For males, all behavioral variables were predictive of suicidal ideation. For the females, unlike the males, Wang-tta or victim of bullying behavior and sexual orientation as behavioral variables were predictive of suicidal ideation. For males, parental divorce and parental alcohol abuse as psychosocial-environmental variables were predictive of suicidal ideation. For the females, again unlike for the males, all the psychosocial-environmental variables were not predictive of suicidal ideation. The most important predictors of suicidal ideation for males as a result of the multivariate analysis were history of suicidal attempt, depression, hostility, smoking, parental alcohol abuse, communication with friends, and self-esteem. The most important predictors of suicidal ideation for females as a result of the multivariate analysis were depression, hostility, sexual orientation, and self-esteem. These results would indicate that an effective suicide screening and prevention program for adolescents should consider gender differences.


Assuntos
Suicídio/psicologia , Adolescente , Estudos Transversais , Feminino , Previsões , Humanos , Coreia (Geográfico) , Masculino , Fatores de Risco , Fatores Sexuais , Meio Social , Prevenção do Suicídio
13.
Yonsei Med J ; 46(6): 818-26, 2005 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-16385659

RESUMO

Tumor necrosis factor (TNF)-alpha induces pleiotropic cellular effects through a 55kDa, type 1 receptor (TNFR1) and a 75kDa type 2 receptor (TNFR2). Moreover, it participates in the pathogenesis of several CNS diseases, including demyelinating diseases. TNF-alpha receptors are differentially expressed and are regulated in many cell types. However, data regarding the TNF-alpha receptor expression and regulation in human astrocytes is limited to date. We investigated TNF- receptor expression, its regulation by cytokines, and its functional role in primary cultured human fetal astrocytes, which are the most abundant cellular population in the central nervous system and are known to be immunologically active. In this study, astrocytes were found to constitutively and predominantly transcribe, translate and shed TNFR1 rather than TNFR2, but TNFR2 expression was increased by adding TNF-alpha, IL-1, and IFN-gamma, but not by adding LPS. To determine the functional roles of TNFR1 and TNFR2 on TNF induction, we investigated NF-kappaB activation and TNF-alpha induction after neutralizing TNFR1 and TNFR2 by an antibody treatment. We found that NF-kappaB activation and TNF-alpha induction are blocked by TNFR1 neutralizing antibody treatments.


Assuntos
Astrócitos/metabolismo , Citocinas/farmacologia , Receptores Tipo II do Fator de Necrose Tumoral/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Astrócitos/efeitos dos fármacos , Células Cultivadas , Feto/citologia , Regulação da Expressão Gênica , Humanos , NF-kappa B/metabolismo , RNA Mensageiro/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/fisiologia , Receptores Tipo II do Fator de Necrose Tumoral/genética , Receptores Tipo II do Fator de Necrose Tumoral/fisiologia
14.
Taehan Kanho Hakhoe Chi ; 35(8): 1433-42, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16415624

RESUMO

PURPOSE: The purposes of this study were 1) to examine the differences in suicidal ideation and psychological variables by gender, 2) compare the contribution of demographic-behavioral variables and psychosocial variables in explaining the variance in suicidal ideation, and 3) identify the most important predictors of suicidal ideation for male adolescents and female adolescents. METHODS: The subjects consisted of 271 male adolescents and 230 female adolescents. Data were collected through self-report questionnaires, which were constructed to include SSI-C, DEP subscale of the SCL-90-R, PACI, and SWLS. The data were analyzed by the SPSS/WIN program. RESULTS: Suicidal ideation differed by gender. Depression and family communication differed by gender. The unique contribution of demographic-behavioral variables and psychosocial variables in explaining the variance in suicidal ideation differed between male adolescents and female adolescents. The significant predictors of suicidal ideation for male adolescents were life satisfaction, depression, and family communication, explaining 28% of the variance in suicidal ideation. The significant predictors of suicidal ideation for female adolescents were depression, smoking, and life satisfaction, explaining 38% of the variance in suicidal ideation. CONCLUSION: The findings of this study suggest that the approach to effective suicide prevention program for adolescents should consider gender differences.


Assuntos
Psicologia do Adolescente , Suicídio/psicologia , Adolescente , Depressão/psicologia , Relações Familiares , Feminino , Humanos , Coreia (Geográfico) , Masculino , Análise Multivariada , Análise de Regressão , Fatores de Risco , Fatores Sexuais , Fatores Socioeconômicos , Prevenção do Suicídio
15.
EMBO J ; 23(6): 1381-91, 2004 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-14988734

RESUMO

The cauliflower mosaic virus reinitiation factor TAV interacts with host translation initiation factor 3 (eIF3) and the 60S ribosomal subunit to accomplish translation of polycistronic mRNAs. Interaction between TAV and eIF3g is critical for the reinitiation process. Here, we show that eIF4B can preclude formation of the TAV/eIF3 complex via competition with TAV for eIF3g binding; indeed, the eIF4B- and TAV-binding sites on eIF3g overlap. Our data indicate that eIF4B interferes with TAV/eIF3/40S ribosome complex formation during the first initiation event. Consequently, overexpression of TAV in plant protoplasts affects only second initiation events. Transient overexpression of eIF4B in plant protoplasts specifically inhibits TAV-mediated reinitiation of a second ORF. These data suggest that TAV enters the host translation machinery at the eIF4B removal step to stabilize eIF3 on the translating ribosome, thereby allowing translation of polycistronic viral RNA.


Assuntos
Caulimovirus/genética , Fator de Iniciação 3 em Eucariotos/metabolismo , Fatores de Iniciação em Eucariotos/metabolismo , Fatores de Iniciação de Peptídeos/biossíntese , Fatores de Iniciação de Peptídeos/genética , Ribossomos/metabolismo , Proteínas Virais/biossíntese , Proteínas Virais/genética , Sequência de Aminoácidos , Sítios de Ligação , Linhagem Celular , Fatores de Iniciação em Eucariotos/química , Fatores de Iniciação em Eucariotos/genética , Dados de Sequência Molecular , Ligação Proteica , Protoplastos/metabolismo , Protoplastos/virologia , Alinhamento de Sequência , Nicotiana/genética , Nicotiana/metabolismo , Nicotiana/virologia
16.
Yonsei Med J ; 44(6): 1059-68, 2003 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-14703617

RESUMO

Astrocytes are ubiquitous in the brain and have multiple functions. It is becoming clear that they play an important role in monitoring the neuromicroenvironment, information processing, and signaling in the central nervous system (CNS) in normal conditions and that they respond to CNS injuries. During the development of the CNS, astrocytes play a key role as a substrate for neuronal migration and axonal growth. To identify genes that could participate in astrocyte maturation, we used the differential display reverse transcription-PCR (DDRT-PCR) method. Human fetal astrocytes were cultured and total RNAs were isolated at intervals of 5 days for 50 days. Using 24 primer combinations, we identified a set of 18 candidate cDNAs deriving from the excised DDRT-PCR bands. DNA sequencing revealed 16 genes that have been described already. We found that RTP, TG, hTM-alpha, SPARC, TRIP7, and RPL7 genes were expressed increasingly, while HMGCR, RPL27a, NACA, NPM, and TARBP2 genes were expressed decreasingly, according to their culture stages. We also found two unidentified genes, A3 and C8, which were expressed differently in culture stages; the former was expressed decreasingly and the latter increasingly. These two genes were found in the same amount in genomic DNA from various human cells such as astrocytes, astrocytoma, trophoblasts and lymphocytes. The A3 gene was found only in human genomic DNA, but not in rat (ATr5), mouse (RAW264.7), or monkey (Vero) cells, whereas the C8 gene was found in human genomic DNA and monkey cells, but not in rat or mouse cells. We analysed these two genes for identification. There was >92% nucleotide sequence identity between the A3 gene (3,626 bp) and the Homo sapiens general transcription factor 3 (GTF3), and >96% nucleotide sequence identity between the C8 gene (2,401 bp) and the transmembrane receptor Unc5h2. These findings suggest that these two genes may participate in some functional roles within the cells.


Assuntos
Astrócitos/fisiologia , Feto/fisiologia , Expressão Gênica , Animais , Células Cultivadas , Senescência Celular/genética , Chlorocebus aethiops , Desenvolvimento Embrionário e Fetal , Perfilação da Expressão Gênica , Humanos , Camundongos , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Vero
17.
Biochem Biophys Res Commun ; 294(5): 940-8, 2002 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-12074567

RESUMO

betaig-h3 is an extracellular matrix protein and its expression is highly induced by TGF-beta and it has also been suggested to play important roles in skin wound healing. In this paper, we demonstrate that betaig-h3 is present in the papillary layer of dermis and synthesized in the basal keratinocytes in vivo and its expression is induced by TGF-beta in normal human keratinocytes (NHEK) and HaCaT cells. betaig-h3 mediates not only adhesion and spreading of keratinocytes but also supports migration and proliferation. These activities are mediated through interacting with alpha3beta1 integrin. Previously identified two alpha3beta1 integrin-interacting motifs of betaig-h3, EPDIM, and NKDIL, are responsible for these activities. The results suggest that betaig-h3 may regulate keratinocyte functions in normal skin and potentially during wound-healing process.


Assuntos
Adesão Celular , Movimento Celular , Proteínas da Matriz Extracelular , Integrinas/fisiologia , Queratinócitos/fisiologia , Proteínas de Neoplasias/farmacologia , Sequência de Aminoácidos , Divisão Celular , Linhagem Celular , Células Cultivadas , Sequência Conservada , Derme/anatomia & histologia , Derme/química , Humanos , Integrina alfa3beta1 , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/química , Peptídeos/química , Peptídeos/farmacologia , Pele/citologia , Fator de Crescimento Transformador beta/farmacologia
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