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1.
BMC Womens Health ; 20(1): 101, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32393366

RESUMO

BACKGROUND: The postoperative severity of symptoms among women with breast cancer affects their quality of life (QoL). Although it is recommended that performing shoulder-arm exercise 30 min/day can alleviate symptoms and improve the QoL, there is little research on the mediating effects of performing shoulder-arm exercise 30 min/day on the postoperative severity of symptoms and QoL among patients with breast cancer. METHODS: A cross-sectional study was conducted 2 ~ 4 months after surgery on women diagnosed with breast cancer but with no distant metastasis and who had undergone breast cancer surgery for the first time. A structured questionnaire was employed which included a severity of symptoms scale, performing shoulder-arm exercise for 30 min/day, a QoL scale, demographic characteristics, and medical status. RESULTS: In total, 117 women with breast cancer completed the survey. The severity of symptoms and performing shoulder-arm exercise 30 min/day separately affected the QoL (B = -0.447, standard error (SE) = 0.050, p < 0.001; B = 15.666, SE = 4.542, p = 0.001, respectively). In model 3, performing shoulder-arm exercise for 30 min/day played a partial mediating role in the relationship of the severity of symptoms and QoL (R2 = 0.51, F = 5.41, p < 0.001). CONCLUSIONS: During 2 ~ 4 months after surgery, regular shoulder-arm exercise for 30 min/day could decrease the effect of the severity of symptoms on the QoL among women with breast cancer. Clinical healthcare providers may inform and educate patients as to the benefits of regular shoulder-arm exercise for 30 min/day.


Assuntos
Braço/fisiopatologia , Neoplasias da Mama/reabilitação , Exercício Físico/psicologia , Qualidade de Vida/psicologia , Ombro/fisiopatologia , Atividades Cotidianas , Adulto , Idoso , Neoplasias da Mama/psicologia , Neoplasias da Mama/cirurgia , Estudos Transversais , Exercício Físico/fisiologia , Feminino , Humanos , Mastectomia , Pessoa de Meia-Idade , Período Pós-Operatório , Índice de Gravidade de Doença , Inquéritos e Questionários
2.
Int J Qual Health Care ; 31(10): 798-803, 2019 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-31125086

RESUMO

OBJECTIVE: The objective of this study was to examine the impact of urban landscape from window views on quality of care for women who underwent Cesarean Section (C-section) in Taiwan. DESIGN: The participants were randomly assigned into 46 different hospital rooms to see the effects of various window views and daylight exposure on women's recovery from post C-section care. SETTING: We carried out this study in the obstetrics departments of three tertiary hospitals located in two major cities of Taiwan: Taipei City and New Taipei City. PARTICIPANTS: A total of 296 women who underwent C-sections and used patient-controlled analgesic (PCA) for pain control after their surgery during the 10-month data collection period were recruited for this study. INTERVENTION: The 46 different patient rooms provided diverse window views and different daylight exposure for the participants. MAIN OUTCOME MEASURES: Recovery for the women who underwent C-sections in this study was defined as PCA usage and perceived pain measured by Brief Pain Inventory (BFI). RESULTS: Higher satisfaction of window view significantly decreased analgesic usage (P = 0.057), reduced the scores of overall perceived pain (P = 0.046), pain severity (P = 0.004), and 'pain's interference with relations with others, enjoyment of life, and mood (REM).' (P = 0.095). CONCLUSIONS: To maximize benefit and well-being of patients recovering from surgery, health care architects should design patient rooms to create maximum satisfaction with visual impacts and optimize window views. By doing so, it may decrease the use of pain medication and substantially reduce healthcare costs.


Assuntos
Cesárea/efeitos adversos , Natureza , Dor Pós-Operatória/prevenção & controle , Luz Solar , Adulto , Analgesia Controlada pelo Paciente , Analgésicos/uso terapêutico , Cesárea/psicologia , Feminino , Ambiente de Instituições de Saúde , Hospitais Urbanos , Humanos , Pessoa de Meia-Idade , Manejo da Dor/psicologia , Dor Pós-Operatória/psicologia , Satisfação do Paciente , Quartos de Pacientes , Gravidez , Taiwan , Centros de Atenção Terciária
3.
Perspect Psychiatr Care ; 55(3): 517-526, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30734309

RESUMO

PURPOSE: This study explored the medical comorbidities of mental disorders using association rule mining. DESIGN AND METHODS: Patients diagnosed with mental disorders between 2002 and 2010 were identified. An equal number of nonmental disorder subjects were randomly selected and matched with case group by age and gender. FINDINGS: Sleep disorders and digestive diseases were frequent comorbidities among mental disorders. The specific medical comorbidities were diabetes mellitus, chronic liver disease, extrapyramidal diseases, disorders of stomach function, general symptoms, sleep disturbance, and family circumstances. PRACTICE IMPLICATIONS: The results suggest that education of professional knowledge of comorbid conditions should be provided to nurses for caring patients with mental illnesses.


Assuntos
Comorbidade , Mineração de Dados , Transtornos Mentais/epidemiologia , Adulto , Distribuição por Idade , Idoso , Estudos de Casos e Controles , Bases de Dados Factuais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Programas Nacionais de Saúde/estatística & dados numéricos , Distribuição por Sexo , Taiwan/epidemiologia
4.
Infect Control Hosp Epidemiol ; 38(4): 417-422, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27995837

RESUMO

OBJECTIVE Effective perioperative hand antisepsis is crucial for the safety of patients and medical staff in surgical rooms. The antimicrobial effectiveness of different antiseptic methods, including conventional hand scrubs and waterless hand rubs, has not been well evaluated. DESIGN, SETTING, AND PARTICIPANTS A randomized controlled trial was conducted to investigate the effectiveness of the 3 antiseptic methods among surgical staff of Taipei Medical University-Shuang Ho Hospital. For each method used, a group of 80 participants was enrolled. INTERVENTION Surgical hand cleansing with conventional 10% povidone-iodine scrub, conventional 4% chlorhexidine scrub, or waterless hand rub (1% chlorhexidine gluconate and 61% ethyl alcohol). RESULTS Colony-forming unit (CFU) counts were collected using the hand imprinting method before and after disinfection and after surgery. After surgical hand disinfection, the mean CFU counts of the conventional chlorhexidine (0.5±0.2, P<0.01) and waterless hand rub groups (1.4±0.7, P<0.05) were significantly lower than that of the conventional povidone group (4.3±1.3). No significant difference was observed in the mean CFU count among the groups after surgery. Similar results were obtained when preexisting differences before disinfection were considered in the analysis of covariance. Furthermore, multivariate regression indicated that the antiseptic method (P=.0036), but not other variables, predicted the mean CFU count. CONCLUSIONS Conventional chlorhexidine scrub and waterless hand rub were superior to a conventional povidone-iodine product in bacterial inhibition. We recommend using conventional chlorhexidine scrub as a standard method for perioperative hand antisepsis. Waterless hand rub may be used if the higher cost is affordable. Infect Control Hosp Epidemiol 2017;38:417-422.


Assuntos
Anti-Infecciosos Locais , Clorexidina , Desinfecção das Mãos/métodos , Higienizadores de Mão , Mãos/microbiologia , Povidona-Iodo , Contagem de Colônia Microbiana , Humanos , Enfermagem de Centro Cirúrgico , Método Simples-Cego , Cirurgiões
5.
Cell Cycle ; 14(8): 1207-17, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25802931

RESUMO

Mouse embryonic stem cells (ES cells) can proliferate indefinitely. To identify potential signals involved in suppression of self-renewal, we previously screened a kinase/phosphatase expression library in ES cells, and observed that inhibition of Dual Leucine zipper-bearing Kinase (DLK) increased relative cell numbers. DLK protein was detected in both the pluripotent and differentiated states of mouse ES cells while DLK kinase activity increased upon differentiation. Overexpression of DLK in mouse ES cells displayed reductions in relative cell/colony numbers and Nanog expression, suggesting a suppressive role of DLK in self-renewal. By examining protein sequences of DLK, we identified 2 putative Akt phosphorylation sites at S584 and T659. Blocking PI3K/Akt signaling with LY-294002 enhanced DLK kinase activity dramatically. We found that Akt interacts with and phosphorylates DLK. Mutations of DLK amino acid residues at putative Akt phosphorylation sites (S584A, T659A, or S584A and T659A) diminished the level of DLK phosphorylation. While the mutated DLKs (S584A, T659A, or S584A and T659A) were expressed, a further reduction in cell/colony numbers and Nanog expression appeared in mouse ES cells. In addition, these mutant DLKs (S584A, T659A, or S584A and T659A) exhibited more robust kinase activity and cell death compared to wild type DLK or green fluorescence (GFP) controls. In summary, our results show that DLK functions to suppress self-renewal of mouse ES cells and is restrained by Akt phosphorylation.


Assuntos
MAP Quinase Quinase Quinases/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sequência de Aminoácidos , Animais , Diferenciação Celular , Linhagem Celular , Cromonas/farmacologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , MAP Quinase Quinase Quinases/antagonistas & inibidores , MAP Quinase Quinase Quinases/genética , Camundongos , Dados de Sequência Molecular , Morfolinas/farmacologia , Células-Tronco Embrionárias Murinas/citologia , Mutagênese Sítio-Dirigida , Proteína Homeobox Nanog , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Ratos , Alinhamento de Sequência , Transdução de Sinais/efeitos dos fármacos
6.
J Biol Chem ; 289(29): 20170-81, 2014 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-24898246

RESUMO

Cobra cardiotoxins (CTX) are a family of three-fingered basic polypeptides known to interact with diverse targets such as heparan sulfates, sulfatides, and integrins on cell surfaces. After CTX bind to the membrane surface, they are internalized to intracellular space and exert their cytotoxicity via an unknown mechanism. By the combined in vitro kinetic binding, three-dimensional x-ray structure determination, and cell biology studies on the naturally abundant CTX homologues from the Taiwanese cobra, we showed that slight variations on the spatial distribution of positively charged or hydrophobic domains among CTX A2, A3, and A4 could lead to significant changes in their endocytotic pathways and action mechanisms via distinct sulfated glycoconjugate-mediated processes. The intracellular locations of these structurally similar CTX after internalization are shown to vary between the mitochondria and lysosomes via either dynamin2-dependent or -independent processes with distinct membrane cholesterol sensitivity. Evidence is presented to suggest that the shifting between the sulfated glycoconjugates as distinct targets of CTX A2, A3, and A4 might play roles in the co-evolutionary arms race between venomous snake toxins to cope with different membrane repair mechanisms at the cellular levels. The sensitivity of endocytotic routes to the spatial distribution of positively charged or hydrophobic domains may provide an explanation for the diverse endocytosis pathways of other cell-penetrating basic polypeptides.


Assuntos
Proteínas Cardiotóxicas de Elapídeos/química , Proteínas Cardiotóxicas de Elapídeos/farmacocinética , Sequência de Aminoácidos , Animais , Sítios de Ligação , Células CHO , Linhagem Celular , Membrana Celular/metabolismo , Proteínas Cardiotóxicas de Elapídeos/genética , Cricetinae , Cricetulus , Cristalografia por Raios X , Elapidae/genética , Elapidae/metabolismo , Endocitose , Evolução Molecular , Glicoconjugados/química , Glicoconjugados/metabolismo , Heparitina Sulfato/química , Heparitina Sulfato/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Dados de Sequência Molecular , Domínios e Motivos de Interação entre Proteínas , Ratos , Eletricidade Estática , Homologia Estrutural de Proteína
7.
Geriatr Nurs ; 35(3): 212-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24679550

RESUMO

We conducted this study to investigate how an exercise program affects the risk components of metabolic syndrome (MS), serum interleukin (IL)-6 levels, and exercise capacity in postmenopausal women. A randomized clinical trial design was used. Women in an exercise group participated in a treadmill-exercise program for 12 weeks, whereas women in a control group maintained their customary lifestyle. Data on variables were collected at baseline and after 12 weeks of the study, which was completed by 46 women (mean age, 56.0 ± 7.0 y). Our results indicate endurance exercise exerted significant beneficial effects on waist circumference, serum high-density lipoprotein cholesterol (HDL-C) and IL-6 levels, and exercise capacity (all P < 0.05). The beneficial effects on IL-6 and exercise capacity were correlated with improvements in HDL-C levels (r = -0.33, P = 0.03 and r = 0.31, P = 0.04, respectively). Our results suggest that health-care providers can incorporate an exercise program in treatments to improve the health of postmenopausal women.


Assuntos
Interleucina-6/fisiologia , Síndrome Metabólica/fisiopatologia , Resistência Física , Pós-Menopausa , Feminino , Humanos , Pessoa de Meia-Idade , Fatores de Risco
8.
J Cell Sci ; 126(Pt 6): 1440-53, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23418360

RESUMO

MicroRNAs are known to play regulatory roles in gene expression associated with cancer development. We analyzed levels of the microRNA miR-24 in patients with breast carcinoma and found that miR-24 was higher in breast carcinoma samples than in benign breast tissues. We generated constructs expressing miR-24 and studied its functions using both in vitro and in vivo techniques. We found that the ectopic expression of miR-24 promoted breast cancer cell invasion and migration. In vivo experiments in mice indicated that the expression of miR-24 enhanced tumor growth, invasion into local tissues, metastasis to lung tissues and decreased overall mouse survival. In the miR-24-expressing cells and tumors, EGFR was highly phosphorylated, whereas expression of the phosphatases tyrosine-protein phosphatase non-receptor type 9 (PTPN9) and receptor-type tyrosine-protein phosphatase F (PTPRF) were repressed. We confirmed that miR-24 could directly target both PTPN9 and PTPRF. Consistent with this, we found that the levels of phosphorylated epidermal growth factor receptor (pEGFR) were higher whereas the levels of PTPN9 and PTPRF were lower in the patients with metastatic breast carcinoma. Ectopic expression of PTPN9 and PTPRF decreased pEGFR levels, cell invasion, migration and tumor metastasis. Furthermore, we found that MMP2, MMP11, pErk, and ADAM15 were upregulated, whereas TIMP2 was downregulated; all of which supported the roles of miR-24 in tumor invasion and metastasis. Our results suggest that miR-24 plays a key role in breast cancer invasion and metastasis. miR-24 could potentially be a target for cancer intervention.


Assuntos
Neoplasias da Mama/patologia , MicroRNAs/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Proteínas Tirosina Fosfatases Classe 2 Semelhantes a Receptores/metabolismo , Animais , Neoplasias da Mama/genética , Processos de Crescimento Celular/genética , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , MicroRNAs/genética , Invasividade Neoplásica/genética , Metástase Neoplásica , Transplante de Neoplasias , Proteínas Tirosina Fosfatases não Receptoras/genética , Proteínas Tirosina Fosfatases Classe 2 Semelhantes a Receptores/genética , Transdução de Sinais/genética , Transgenes/genética
9.
Stem Cells ; 30(10): 2199-211, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22899353

RESUMO

In contrast to the somatic cells, embryonic stem cells (ESCs) are characterized by its immortalization ability, pluripotency, and oncogenicity. Revealing the underlying mechanism of ESC characteristics is important for the application of ESCs in clinical medicine. We performed systematic functional screen in mouse ESCs with 4,801 shRNAs that target 929 kinases and phosphatases. One hundred and thirty-two candidate genes that regulate both ESC expansion and stem cell marker expression were identified. Twenty-seven out of the 132 genes were regarded as most important since knockdown of each gene induces morphological changes from undifferentiated to differentiated state. Among the 27 genes, we chose nonmetastatic cell 6 (Nme6, also named as Nm23-H6) and nonmetastatic cell 7 (Nme7, also designated as Nm23-H7) to study first. Nme6 and Nme7 both belong to the members of nucleoside diphosphate kinase family. We demonstrate that Nme6 and Nme7 are important for the regulation of Oct4, Nanog, Klf4, c-Myc, telomerase, Dnmt3B, Sox2, and ERas expression. Either knockdown of Nme6 or Nme7 reduces the formation of embryoid body (EB) and teratoma. The overexpression of either Nme6 or Nme7 can rescue the stem cell marker expression and the EB formation in the absence of leukemia inhibiting factor. This implies the importance of Nme6 and Nme7 in ESC renewal. This finding not only pinpoints Nme6 or Nme7 can regulate several critical regulators in ESC renewal but also increases our understanding of the ESC renewal and oncogenesis.


Assuntos
Células-Tronco Embrionárias/metabolismo , Núcleosídeo-Difosfato Quinase/genética , Células-Tronco Pluripotentes/metabolismo , RNA Interferente Pequeno/genética , Animais , Diferenciação Celular , Linhagem Celular , Células-Tronco Embrionárias/citologia , Expressão Gênica , Perfilação da Expressão Gênica , Técnicas de Inativação de Genes , Ensaios de Triagem em Larga Escala , Fator 4 Semelhante a Kruppel , Camundongos , Núcleosídeo-Difosfato Quinase/metabolismo , Células-Tronco Pluripotentes/citologia
10.
Biochem J ; 433(1): 127-38, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-20964630

RESUMO

HDGF (hepatoma-derived growth factor) stimulates cell proliferation by functioning on both sides of the plasma membrane as a ligand for membrane receptor binding to trigger cell signalling and as a stimulator for DNA synthesis in the nucleus. Although HDGF was initially identified as a secretory heparin-binding protein, the biological significance of its heparin-binding ability remains to be determined. In the present study we demonstrate that cells devoid of surface HS (heparan sulfate) were unable to internalize HDGF, HATH (N-terminal domain of HDGF consisting of amino acid residues 1-100, including the PWWP motif) and HATH(K96A) (single-site mutant form of HATH devoid of receptor binding activity), suggesting that the binding of HATH to surface HS is important for HDGF internalization. We further demonstrate that both HATH and HATH(K96A) could be internalized through macropinocytosis after binding to the cell surface HS. Interestingly, HS-mediated HATH(K96A) internalization is found to exhibit an inhibitory effect on cell migration and proliferation in contrast with that observed for HATH action on NIH 3T3 cells, suggesting that HDGF exploits the innate properties of both cell surface HS and membrane receptor via the HATH domain to affect related cell signalling processes. The present study indicates that MAPK (mitogen-activated protein kinase) signalling pathways could be affected by the HS-mediated HATH internalization to regulate cell migration in NIH 3T3 fibroblasts, as judged from the differential effect of HATH and HATH(K96A) treatment on the expression level of matrix metalloproteases.


Assuntos
Movimento Celular , Fibroblastos/fisiologia , Heparitina Sulfato/fisiologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Pinocitose , Transdução de Sinais/fisiologia , Células 3T3 , Animais , Membrana Celular/química , Proliferação de Células , Fibroblastos/citologia , Metaloproteinases da Matriz/biossíntese , Camundongos , Estrutura Terciária de Proteína
11.
PLoS One ; 4(10): e7535, 2009 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-19844573

RESUMO

MicroRNAs (miRNAs) are small fragments of single-stranded RNA containing 18-24 nucleotides, and are generated from endogenous transcripts. MicroRNAs function in post-transcriptional gene silencing by targeting the 3'-untranslated region (UTR) of mRNAs, resulting in translational repression. We have developed a system to study the role of miRNAs in cell differentiation. We have found that one of the miRNAs tested in our system (miR-378, also called miR-378*) plays a role in modulating nephronectin-mediated differentiation in the osteoblastic cell line, MC3T3-E1. Nephronectin is an extracellular matrix protein, and we have demonstrated that its over-expression enhanced osteoblast differentiation and bone nodule formation. Furthermore, we found that the nephronectin 3'-untranslated region (3'UTR) contains a binding site for miR-378. Stable transfection of MC3T3-E1 cells with miR-378 inhibited cell differentiation. MC3T3-E1 cells stably transfected with nephronectin exhibited higher rates of differentiation and nodule formation as compared with cells transfected with nephronectin containing the 3'UTR in the early stages of development, suggesting that endogenous miR-378 is present and active. However, in the later stages of MC3T3-E1 development, the differentiation rates were opposite, with higher rates of differentiation and nodule formation in the cells over-expressing the 3'UTR of nephronectin. This appeared to be the consequence of competition between nephronectin and UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 7 (GalNAc-T7 or GalNT7) for miR-378 binding, resulting in increased GalNT7 activity, which in turn lead to increased nephronectin glycosylation and product secretion, thereby resulting in a higher rate of osteoblast differentiation.


Assuntos
Proteínas da Matriz Extracelular/biossíntese , Proteínas da Matriz Extracelular/genética , Regulação da Expressão Gênica , MicroRNAs/fisiologia , N-Acetilgalactosaminiltransferases/metabolismo , Osteoblastos/citologia , Regiões 3' não Traduzidas , Animais , Sequência de Bases , Diferenciação Celular , Linhagem Celular , Glicosilação , Humanos , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Dados de Sequência Molecular , Osteoblastos/metabolismo , Polipeptídeo N-Acetilgalactosaminiltransferase
12.
PLoS One ; 3(6): e2420, 2008 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-18560585

RESUMO

Morphogenesis is crucial to initiate physiological development and tumor invasion. Here we show that a microRNA controls zonation morphogenesis by targeting hyaluronan receptor CD44. We have developed a novel system to study microRNA functions by generating constructs expressing pre-miRNAs and mature miRNAs. Using this system, we have demonstrated that expression of miR-328 reduced cell adhesion, aggregation, and migration, and regulated formation of capillary structure. Protein analysis indicated that miR-328 repressed CD44 expression. Activities of luciferase constructs harboring the target site in CD44, but not the one containing mutation, were repressed by miR-328. Zonation morphogenesis appeared in cells transfected by miR-328: miR-328-transfected cells were present on the surface of zonating structures while the control cells stayed in the middle. MiR-328-mediated CD44 actions was validated by anti-CD44 antibody, hyaluronidase, CD44 siRNA, and CD44 expression constructs. In vivo experiments showed that CD44-silencing cells appeared as layers on the surfaces of nodules or zonating structures. Immuno-histochemistry also exhibited CD44-negative cells on the surface layers of normal rat livers and the internal zones of Portal veins. Our results demonstrate that miR-328 targets CD44, which is essential in regulating zonation morphogenesis: silencing of CD44 expression is essential in sealing the zonation structures to facilitate their extension and to inhibit complex expansion.


Assuntos
Receptores de Hialuronatos/metabolismo , MicroRNAs/genética , Morfogênese , Animais , Western Blotting , Capilares/crescimento & desenvolvimento , Adesão Celular , Citometria de Fluxo , Imuno-Histoquímica , Camundongos , Camundongos Nus , RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Proc Natl Acad Sci U S A ; 104(51): 20350-5, 2007 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-18077375

RESUMO

MicroRNAs are single-stranded RNA of 18-24 nt expressed endogenously that play important roles in cancer development. Here, we show that expression of miR-378 enhances cell survival, reduces caspase-3 activity, and promotes tumor growth and angiogenesis. Proteomic analysis indicates reduced expression of suppressor of fused (Sufu), a potential target of miR-378, which was confirmed in vitro and in vivo. Expression of a luciferase construct containing the target site in Sufu was repressed when cotransfected with miR-378. Transfection of a Sufu construct reversed the effect of miR-378, suggesting an important role for miR-378 in tumor cell survival. We also discovered that miR-378 targets Fus-1. Expression of luciferase constructs harboring the target sites in Fus-1 was repressed by miR-378. Fus-1 constructs with or without its 3' UTR were also generated. Cotransfection experiments showed that the presence of miR-378 repressed Fus-1 expression. Suppression of Fus-1 expression by siRNA against Fus-1 enhanced cell survival. Transfection of the Fus-1 construct reversed the function of miR-378 in cell survival. Our results suggest that miR-378 transfection enhanced cell survival, tumor growth, and angiogenesis through repression of the expression of two tumor suppressors, Sufu and Fus-1.


Assuntos
Proliferação de Células , MicroRNAs/fisiologia , Neovascularização Patológica/genética , Proteínas Repressoras/antagonistas & inibidores , Proteínas Supressoras de Tumor/antagonistas & inibidores , Animais , Pareamento de Bases , Linhagem Celular , Sobrevivência Celular , Humanos , Camundongos , Camundongos Endogâmicos , MicroRNAs/genética , MicroRNAs/farmacologia , Dados de Sequência Molecular , Proteínas Repressoras/genética , Transfecção , Proteínas Supressoras de Tumor/genética
14.
J Biol Chem ; 281(1): 656-67, 2006 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-16263708

RESUMO

Cobra cardiotoxins, a family of basic polypeptides having lipid- and heparin-binding capacities similar to the cell-penetrating peptides, induce severe tissue necrosis and systolic heart arrest in snakebite victims. Whereas cardiotoxins are specifically retained on the cell surface via heparan sulfate-mediated processes, their lipid binding ability appears to be responsible, at least in part, for cardiotoxin-induced membrane leakage and cell death. Although the exact role of lipids involved in toxin-mediated cytotoxicity remains largely unknown, monoclonal anti-sulfatide antibody O4 has recently been shown to inhibit the action of CTX A3, the major cardiotoxin from Taiwan cobra venom, on cardiomyocytes by preventing cardiotoxin-induced membrane leakage and CTX A3 internalization into mitochondria. Here, we show that anti-sulfatide acts by blocking the binding of CTX A3 to the sulfatides in the plasma membrane to prevent sulfatide-dependent CTX A3 membrane pore formation and internalization. We also describe the crystal structure of a CTX A3-sulfatide complex in a membrane-like environment at 2.3 angstroms resolution. The unexpected orientation of the sulfatide fatty chains in the structure allows prediction of the mode of toxin insertion into the plasma membrane. CTX A3 recognizes both the headgroup and the ceramide interfacial region of sulfatide to induce a lipid conformational change that may play a key role in CTX A3 oligomerization and cellular internalization. This proposed lipid-mediated toxin translocation mechanism may also shed light on the cellular uptake mechanism of the amphiphilic cell-penetrating peptides known to involve multiple internalization pathways.


Assuntos
Proteínas Cardiotóxicas de Elapídeos/química , Proteínas Cardiotóxicas de Elapídeos/farmacocinética , Miócitos Cardíacos/metabolismo , Sulfoglicoesfingolipídeos/metabolismo , Animais , Anticorpos , Membrana Celular/metabolismo , Células Cultivadas , Dimerização , Bicamadas Lipídicas/metabolismo , Potenciais da Membrana/fisiologia , Proteínas de Membrana/metabolismo , Miócitos Cardíacos/citologia , Técnicas de Patch-Clamp , Estrutura Quaternária de Proteína , Estrutura Terciária de Proteína , Ratos , Ratos Wistar , Sulfoglicoesfingolipídeos/imunologia
15.
Toxicon ; 46(4): 430-40, 2005 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-16081119

RESUMO

Cobra cardiotoxins (CTXs) are basic polypeptides with diverse pharmacological functions that are cytotoxic to many different cell types through both necrotic and apoptotic cell death pathways. In this comparative study of the action of CTX A3 from the Taiwan cobra (Naja atra) on fetal rat cardiomyocytes and cortical neurons, it was shown that CTX A3 induced different patterns of elevation of intracellular Ca2+ concentration ([Ca2+]i), CTX internalization, caspase-3 activity and viability. Application of an anti-sulfatide monoclonal antibody, O4 specific for 3-sulfo-galactose lipid, but not in the control experiments using anti-GM3 monoclonal antibody, reduces CTX-induced [Ca2+]i elevation, CTX internalization and toxicity. Therefore, CTX may target similar sulfo-containing cell surface receptors in both fetal rat cardiomyocytes and cortical neurons, but induce cell death through different pathways specific to each cell type.


Assuntos
Proteínas Cardiotóxicas de Elapídeos/toxicidade , Feto/efeitos dos fármacos , Miocárdio/patologia , Necrose/induzido quimicamente , Neurônios/patologia , Animais , Anticorpos Monoclonais , Cálcio/metabolismo , Caspase 3 , Caspases/metabolismo , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Núcleo Celular/efeitos dos fármacos , Espectrometria de Massas , Neurônios/efeitos dos fármacos , Ratos , Ratos Wistar , Taiwan
16.
FEBS Lett ; 579(14): 3169-74, 2005 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-15922335

RESUMO

Recent advance in understanding the role of toxin proteins in controlling cell death has revealed that pro-apoptotic viral proteins targeting mitochondria contain amphiphilic alpha-helices with pore-forming properties. Herein, we describe that the pore-forming amphiphilic beta-sheet cardiotoxins (or cytotoxins, CTXs) from Taiwan cobra (Naja atra) also target mitochondrial membrane after internalization and act synergistically with CTX-induced cytosolic calcium increase to disrupt mitochondria network. It is suggested that CTX-induced fragmentation of mitochondria play a role in controlling CTX-induced necrosis of myocytes and cause severe tissue necrosis in the victims.


Assuntos
Proteínas Cardiotóxicas de Elapídeos/química , Proteínas Cardiotóxicas de Elapídeos/farmacologia , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias Cardíacas/fisiologia , Animais , Cálcio/metabolismo , Linhagem Celular , Elapidae , Interações Hidrofóbicas e Hidrofílicas , Membranas Intracelulares/efeitos dos fármacos , Modelos Moleculares , Mioblastos/efeitos dos fármacos , Mioblastos/patologia , Necrose , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Ratos , Água/química
17.
J Biol Chem ; 280(10): 9567-77, 2005 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-15590643

RESUMO

Anionic citrate is a major component of venom, but the role of venom citrate in toxicity other than its inhibitory effect on the cation-dependent action of venom toxins is poorly understood. By immobilizing Chinese hamster ovary cells in microcapillary tubes and heparin on sensor chips, we demonstrated that heparan sulfate-mediated cell retention of the major cardiotoxin (CTX) from the Taiwan cobra, CTX A3, near membrane surfaces is citrate-dependent. X-ray determination of a CTX A3-heparin hexasaccharide complex structure at 2.4 A resolution revealed a molecular mechanism for toxin retention in which heparin-induced conformational changes of CTX A3 lead to citrate-mediated dimerization. A citrate ion bound to Lys-23 and Lys-31 near the tip of loop II stabilizes hydrophobic contact of the CTX A3 homodimer at the functionally important loop I and II regions. Additionally, the heparin hexasaccharide interacts with five CTX A3 molecules in the crystal structure, providing another mechanism whereby the toxin establishes a complex network of interactions that result in a strong interaction with cell surfaces presenting heparan sulfate. Our results suggest a novel role for venom citrate in biological activity and reveal a structural model that explains cell retention of cobra CTX A3 through heparan sulfate-CTX interactions.


Assuntos
Membrana Celular/metabolismo , Citratos/farmacologia , Proteínas Cardiotóxicas de Elapídeos/química , Proteínas Cardiotóxicas de Elapídeos/metabolismo , Heparitina Sulfato/farmacologia , Sequência de Aminoácidos , Animais , Venenos Elapídicos/química , Elapidae , Modelos Moleculares , Dados de Sequência Molecular , Oligossacarídeos/química , Conformação Proteica , Estrutura Secundária de Proteína , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Taiwan
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