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1.
Nat Commun ; 15(1): 5962, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39013901

RESUMO

Dual emission (DE) in nanoclusters (NCs) is considerably significant in the research and application of ratiometric sensing, bioimaging, and novel optoelectronic devices. Exploring the DE mechanism in open-shell NCs with doublet or quartet emissions remains challenging because synthesizing open-shell NCs is difficult due to their inherent instability. Here, we synthesize two dual-emissive M1Ag13(PFBT)6(TPP)7 (M = Pt, Pd; PFBT = pentafluorobenzenethiol; TPP = triphenylphosphine) NCs with a 7-electron open-shell configuration to reveal the DE mechanism. Both NCs comprise a crown-like M1Ag11 kernel with Pt or Pd in the center surrounded by five PPh3 ligands and two Ag(SR)3(PPh3) motifs. The combined experimental and theoretical studies revealed the origin of DE in Pt1Ag13 and Pd1Ag13. Specifically, the high-energy visible emission and the low-energy near-infrared emission arise from two distinct quartet excited states: the core-shell charge transfer and core-based states, respectively. Moreover, PFBT ligands are found to play an important role in the existence of DE, as its low-lying π* levels result in energetically accessible core-shell transitions. This novel report on the dual-quartet phosphorescent emission in NCs with an open-shell electronic configuration advances insights into the origin of dual-emissive NCs and promotes their potential application in magnetoluminescence and novel optoelectronic devices.

2.
Differentiation ; 135: 100744, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38128465

RESUMO

Differentiation of human umbilical cord mesenchymal stem cells (Uc-MSCs) into islet-like clusters which are capable of synthesizing and secreting insulin can potentially serve as donors for islet transplantation in the patient deficiency in islet ß cell function both in type 1 or type 2 diabetic patients. Therefore, we developed an easy and higher efficacy approach by trypsinazing the Uc-MSCs and followed culture in differentiation medium to induce of Uc-MSCs differentiation into islet-like clusters, and the potential mechanism that in the early stage of differentiation was also investigated by using RNA-sequencing and bioinformatics. Results show that induction efficacy was reached to 98% and TGF-ß signaling pathway may play critical role in the early stage differentiation, it was further confirmed that the retardant effect of differentiation progress either in cell morphology or in islet specific genes expression can be observed upon blocking the activation of TGF-ß signaling pathway using specific inhibitor of LY2109761 (TßRI/II kinase inhibitor). Our current study, for the first time, development a protocol for differentiation of Uc-MSCs into islet-like clusters, and revealed the importance of TGF-ß signaling pathway in the early stage of differentiation of Uc-MSCs into islet-like clusters. Our study will provide alternative approach for clinical treatment of either type I or type II diabtes mellitus with dysfunctional pancreatic islets.


Assuntos
Células Secretoras de Insulina , Células-Tronco Mesenquimais , Humanos , Insulina , Tripsina/metabolismo , Diferenciação Celular/genética , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Transdução de Sinais , Cordão Umbilical
3.
World J Surg Oncol ; 21(1): 83, 2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36882854

RESUMO

PURPOSE: The study aimed to construct a predictive model for clinically significant prostate cancer (csPCa) and investigate its clinical efficacy to reduce unnecessary prostate biopsies. METHODS: A total of 847 patients from institute 1 were included in cohort 1 for model development. Cohort 2 included a total of 208 patients from institute 2 for external validation of the model. The data obtained were used for retrospective analysis. The results of magnetic resonance imaging were obtained using Prostate Imaging Reporting and Data System version 2.1 (PI-RADS v2.1). Univariate and multivariate analyses were performed to determine significant predictors of csPCa. The diagnostic performances were compared using the receiver operating characteristic (ROC) curve and decision curve analyses. RESULTS: Age, prostate-specific antigen density (PSAD), and PI-RADS v2.1 scores were used as predictors of the model. In the development cohort, the areas under the ROC curve (AUC) for csPCa about age, PSAD, PI-RADS v2.1 scores, and the model were 0.675, 0.823, 0.875, and 0.938, respectively. In the external validation cohort, the AUC values predicted by the four were 0.619, 0.811, 0.863, and 0.914, respectively. Decision curve analysis revealed that the clear net benefit of the model was higher than PI-RADS v2.1 scores and PSAD. The model significantly reduced unnecessary prostate biopsies within the risk threshold of > 10%. CONCLUSIONS: In both internal and external validation, the model constructed by combining age, PSAD, and PI-RADS v2.1 scores exhibited excellent clinical efficacy and can be utilized to reduce unnecessary prostate biopsies.


Assuntos
Imageamento por Ressonância Magnética Multiparamétrica , Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/diagnóstico por imagem , Imageamento por Ressonância Magnética , Antígeno Prostático Específico , Estudos Retrospectivos
4.
Curr Med Res Opin ; 38(4): 487-499, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35119325

RESUMO

BACKGROUND: Patients with minor stroke suffer a substantial risk of further recurrences, especially in the first two weeks. We aimed to develop and validate a prognostic nomogram to predict in-hospital stroke recurrence among patients with acute minor stroke. METHODS: A total of 1326 patients with minor non-cardiac stroke (NIHSS) ≤5) from three centers were divided into development cohort (1016 patients from two centers) and validation cohort (310 patients from another center). Recurrent stroke was defined as a new ischemic stroke. A logistic regression model was employed to develop the nomogram to predict in-hospital stroke recurrence in patients with minor stroke using demographic, medical and imaging information. We then validated the nomogram externally. The predictive discrimination and calibration of the nomogram were assessed in the development and validation cohorts by area under the curve (AUC) and calibration plots. RESULTS: During a median length of stay of 12 days, stroke recurrence occurred in 34 patients (3.3%). Predictors of in-hospital recurrence included prior history of transient ischemic attack, baseline NIHSS score, multiple infarctions, and carotid stenosis. The clinical and imaging-based nomogram B demonstrated adequate calibration and discrimination (AUC = 0.777), which was validated among 273 patients in a separate validation cohort (AUC = 0.753). Our clinical-imaging based nomogram was determined to be superior to the clinical-based nomogram and the RRE90 score in terms of discrimination. CONCLUSION: A prognostic nomogram that integrates clinical and imaging information to predict the in-hospital risk of stroke recurrence among patients after acute minor stroke was constructed and validated externally. The nomogram demonstrated adequate calibration and discrimination in both the development and validation cohort.


Assuntos
Ataque Isquêmico Transitório , Acidente Vascular Cerebral , Hospitais , Humanos , Nomogramas , Prognóstico , Acidente Vascular Cerebral/diagnóstico
5.
J Comput Assist Tomogr ; 45(3): 442-446, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34297513

RESUMO

OBJECTIVE: This study aimed to evaluate the magnetic resonance imaging (MRI) changes of the symphysis pubis in patients with axial spondyloarthritis (ax-SpA) and to assess its association with clinical factors. METHODS: A retrospective analysis of 172 patients with ax-SpA was performed to assess the presence of active inflammatory and structural changes of the symphysis pubis on MRI scans, and their association with clinical factors and the SPARCC (Spondyloarthritis Research Consortium of Canada) scoring of the sacroiliac joint were evaluated. RESULTS: The proportions of active inflammation and structural changes of the symphysis pubis were 69/172 (40.1%) and 54/172 (31.4%), respectively. When comparing the active inflammation and no-active inflammation symphysis pubis groups, the former had higher level C-reactive protein, higher erythrocyte sedimentation rate, and younger median age of patients. Moreover, no significant correlation was noted between the active inflammation of the symphysis pubis and SPARCC score of the sacroiliac joint. When comparing the normal and abnormal symphysis pubis groups, the latter had longer symptom duration. CONCLUSIONS: The MRI changes of the symphysis pubis were seen in 55.2% of the patients with ax-SpA and were associated with C-reactive protein, erythrocyte sedimentation rate, and symptom duration.


Assuntos
Proteína C-Reativa/metabolismo , Sínfise Pubiana/diagnóstico por imagem , Espondilartrite/sangue , Espondilartrite/diagnóstico por imagem , Adolescente , Adulto , Idoso , Sedimentação Sanguínea , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Sínfise Pubiana/patologia , Estudos Retrospectivos , Índice de Gravidade de Doença , Espondilartrite/patologia , Adulto Jovem
6.
Biochem Pharmacol ; 174: 113785, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31887289

RESUMO

Regeneration of ß-cells by differentiation of pancreatic progenitor cells has the potential to fundamentally solve the problems of the loss of ß-cell function and mass during disease progression in both type 1 or 2 diabetes. Therefore, discovery of novel differentiation inducers to promote islet regeneration is of great significance. Pancreatic and duodenal homeobox1 (PDX-1) is a key transcription factor that promotes the development and maturation of pancreatic ß-cells. To screen potential novel small molecules for enhancing differentiation of PNAC-1 cells, a human pancreatic ductal cell lines into insulin-producing cells (IPCs), we developed a high-throughput screening method through fusing the PDX-1 promoter region with a luciferase reporter gene. We screened and identified that andrographolide named C1037 stimulates PDX-1 expression in both mRNA and protein level and significantly promotes PANC-1 cells differentiation into IPCs as compared with that of control cells. The therapeutic effect of C037 in Streptozotocin induced diabetic mouse model through differentiation of pancreatic ductal cells into insulin positive islets was also observed. Our study provides a novel method to screen compounds regulating the differentiation of pancreatic progenitor cells having the potential of enhancing islet regeneration for diabetes therapy.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Diterpenos/farmacologia , Proteínas de Homeodomínio/metabolismo , Hipoglicemiantes/farmacologia , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , Ductos Pancreáticos/efeitos dos fármacos , Transativadores/metabolismo , Andrographis/química , Animais , Técnicas de Cultura de Células , Diferenciação Celular/genética , Linhagem Celular , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Diterpenos/isolamento & purificação , Diterpenos/uso terapêutico , Expressão Gênica/efeitos dos fármacos , Teste de Tolerância a Glucose , Proteínas de Homeodomínio/genética , Humanos , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/uso terapêutico , Células Secretoras de Insulina/metabolismo , Masculino , Camundongos , Ductos Pancreáticos/metabolismo , Transativadores/genética
7.
J Healthc Eng ; 2019: 3750495, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30891170

RESUMO

Tissue hemodynamics, including the blood flow, oxygenation, and oxygen metabolism, are closely associated with many diseases. As one of the portable optical technologies to explore human physiology and assist in healthcare, near-infrared diffuse optical spectroscopy (NIRS) for tissue oxygenation measurement has been developed for four decades. In recent years, a dynamic NIRS technology, namely, diffuse correlation spectroscopy (DCS), has been emerging as a portable tool for tissue blood flow measurement. In this article, we briefly describe the basic principle and algorithms for static NIRS and dynamic NIRS (i.e., DCS). Then, we elaborate on the NIRS instrumentation, either commercially available or custom-made, as well as their applications to physiological studies and clinic. The extension of NIRS/DCS from spectroscopy to imaging was depicted, followed by introductions of advanced algorithms that were recently proposed. The future prospective of the NIRS/DCS and their feasibilities for routine utilization in hospital is finally discussed.


Assuntos
Hemodinâmica/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho , Algoritmos , Animais , Humanos , Camundongos , Oxigênio/sangue , Ratos , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação , Espectroscopia de Luz Próxima ao Infravermelho/métodos
8.
J Tradit Chin Med ; 39(2): 191-198, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-32186041

RESUMO

OBJECTIVE: To determine the therapeutic effect and potential mechanism of Huatan Tongluo decoction on rats with collagen-induced arthritis. METHODS: Forty specific pathogen-free Wistar rats were selected, and 10 were randomly selected as the control (group 1). The remaining rats were injected intradermally with emulsified type II bovine collagen at the tail base and back, followed by a booster 7 d post first immunization. After establishing collagen-induced arthritis (CIA), rats were randomly divided into three groups (n = 10). The rats were treated orally for 30 d as follows: group 1, saline; group 2, model (saline); group 3, tripterygium polyglycoside (TP; 7.81 mg/kg, positive control); group 4, Huatan Tongluo decoction (HTTL; 7.5 g/kg). Body weight, ankle swelling and arthritis index were measured over the course of the study. The rats were sacrificed 30 d after treatment. Morphological changes in the synovium were observed by hematoxylin and eosin staining. Pannus formation and synovial thickness in the left ankle were observed by color Doppler ultrasoundVascular endothelial growth factor (VEGF) and VEGFR2 protein levels were measured by immunohistochemistry. VEGF/VEGFR2 mRNA levels were measured by real-time quantitative polymerase chain reaction. RESULTS: Compared with the model group, a significantly lower arthritis index was observed in the positive control group (P < 0.05) and HTTL group (P < 0.01), after treatment. Both positive control and HTTL reduced intra-articular pannus formation and synovial thickening. Furthermore, VEGF mRNA, and VEGFR2 protein and mRNA levels were significantly downregulated (P < 0.05) in the treatment groups. CONCLUSION: Inhibition of the expression of VEGF and VEGFR2 in synovial tissues and the formation of pannus and synovial hyperplasia may be part of the mechanism of HTTL for relieving the symptoms of rheumatoid arthritis in CIA rats.


Assuntos
Artrite Experimental/metabolismo , Artrite Experimental/patologia , Medicamentos de Ervas Chinesas/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Membrana Sinovial/efeitos dos fármacos , Membrana Sinovial/patologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Antígenos CD34/metabolismo , Artrite Experimental/genética , Medicamentos de Ervas Chinesas/uso terapêutico , Masculino , RNA Mensageiro/genética , Ratos , Ratos Wistar , Membrana Sinovial/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética
9.
J Immunol ; 198(12): 4753-4763, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28526681

RESUMO

The dominant Vγ2Vδ2 T cell subset recognizes phosphoantigen and exists only in humans and nonhuman primates. Despite the discovery of γδ T cells >30 y ago, a proof-of-concept study has not been done to prove the principle that the Vγ2Vδ2 T cell subset is protective against Mycobacterium tuberculosis and other infections. In this study, we used an adoptive cell-transfer strategy to define the protective role of Vγ2Vδ2 T cells in a primate tuberculosis (TB) model. Vγ2Vδ2 T cells for adoptive transfer displayed central/effector memory and mounted effector functions, including the production of anti-M. tuberculosis cytokines and inhibition of intracellular mycobacteria. They also expressed CXCR3/CCR5/LFA-1 trafficking/tissue-resident phenotypes and consistently trafficked to the airway, where they remained detectable from 6 h through 7 d after adoptive transfer. Interestingly, the test group of macaques receiving transfer of Vγ2Vδ2 T cells at weeks 1 and 3 after high-dose (500 CFU) M. tuberculosis infection exhibited significantly lower levels of M. tuberculosis infection burdens in lung lobes and extrapulmonary organs than did the control groups receiving PBLs or saline. Consistently, adoptive transfer of Vγ2Vδ2 T cells attenuated TB pathology and contained lesions primarily in the infection site of the right caudal lung lobe, with no or reduced TB dissemination to other lobes, spleen, or liver/kidney; in contrast, the controls showed widespread TB dissemination. The proof-of-concept finding supports the view that the dominant Vγ2Vδ2 T cell subset may be included in the rational design of a TB vaccine or host-directed therapy.


Assuntos
Transferência Adotiva , Mycobacterium tuberculosis/imunologia , Fosfoproteínas/uso terapêutico , Receptores de Antígenos de Linfócitos T gama-delta/uso terapêutico , Subpopulações de Linfócitos T/imunologia , Tuberculose/imunologia , Tuberculose/terapia , Animais , Carga Bacteriana , Citocinas/biossíntese , Citocinas/imunologia , Memória Imunológica , Pulmão/imunologia , Pulmão/microbiologia , Antígeno-1 Associado à Função Linfocitária/genética , Antígeno-1 Associado à Função Linfocitária/imunologia , Macaca fascicularis , Fosfoproteínas/administração & dosagem , Fosfoproteínas/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Receptores CCR5/genética , Receptores CCR5/imunologia , Receptores CXCR3/genética , Receptores CXCR3/imunologia , Tuberculose/microbiologia
10.
J Virol ; 91(14)2017 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-28356537

RESUMO

Despite a great deal of prior research, the early pathogenic events in natural oral poliovirus infection remain poorly defined. To establish a model for study, we infected 39 macaques by feeding them single high doses of the virulent Mahoney strain of wild type 1 poliovirus. Doses ranging from 107 to 109 50% tissue culture infective doses (TCID50) consistently infected all the animals, and many monkeys receiving 108 or 109 TCID50 developed paralysis. There was no apparent difference in the susceptibilities of the three macaque species (rhesus, cynomolgus, and bonnet) used. Virus excretion in stool and nasopharynges was consistently observed, with occasional viremia, and virus was isolated from tonsils, gut mucosa, and draining lymph nodes. Viral replication proteins were detected in both epithelial and lymphoid cell populations expressing CD155 in the tonsil and intestine, as well as in spinal cord neurons. Necrosis was observed in these three cell types, and viral replication in the tonsil/gut was associated with histopathologic destruction and inflammation. The sustained response of neutralizing antibody correlated temporally with resolution of viremia and termination of virus shedding in oropharynges and feces. For the first time, this model demonstrates that early in the infectious process, poliovirus replication occurs in both epithelial cells (explaining virus shedding in the gastrointestinal tract) and lymphoid/monocytic cells in tonsils and Peyer's patches (explaining viremia), extending previous studies of poliovirus pathogenesis in humans. Because the model recapitulates human poliovirus infection and poliomyelitis, it can be used to study polio pathogenesis and to assess the efficacy of candidate antiviral drugs and new vaccines.IMPORTANCE Early pathogenic events of poliovirus infection remain largely undefined, and there is a lack of animal models mimicking natural oral human infection leading to paralytic poliomyelitis. All 39 macaques fed with single high doses ranging from 107 to 109 TCID50 Mahoney type 1 virus were infected, and many of the monkeys developed paralysis. Virus excretion in stool and nasopharynges was consistently observed, with occasional viremia; tonsil, mesentery lymph nodes, and intestinal mucosa served as major target sites of viral replication. For the first time, this model demonstrates that early in the infectious process, poliovirus replication occurs in both epithelial cells (explaining virus shedding in the gastrointestinal tract) and lymphoid/monocytic cells in tonsils and Peyer's patches (explaining viremia), thereby supplementing historical reconstructions of poliovirus pathogenesis. Because the model recapitulates human poliovirus infection and poliomyelitis, it can be used to study polio pathogenesis, candidate antiviral drugs, and the efficacy of new vaccines.


Assuntos
Macaca , Poliomielite/patologia , Poliovirus/crescimento & desenvolvimento , Poliovirus/patogenicidade , Estruturas Animais/virologia , Animais , Modelos Animais de Doenças , Células Epiteliais/virologia , Fezes/virologia , Leucócitos/virologia , Nasofaringe/virologia , Eliminação de Partículas Virais
11.
Diabetes ; 63(5): 1612-23, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24379354

RESUMO

Pancreatic ß-cell dysfunction is a common feature of type 2 diabetes. Earlier, we had cloned IG20 cDNA from a human insulinoma and had shown that IG20/MADD can encode six different splice isoforms that are differentially expressed and have unique functions, but its role in ß-cell function was unexplored. To investigate the role of IG20/MADD in ß-cell function, we generated conditional knockout (KMA1ko) mice. Deletion of IG20/MADD in ß-cells resulted in hyperglycemia and glucose intolerance associated with reduced and delayed glucose-induced insulin production. KMA1ko ß-cells were able to process insulin normally but had increased insulin accumulation and showed a severe defect in glucose-induced insulin release. These findings indicated that IG20/MADD plays a critical role in glucose-induced insulin release from ß-cells and that its functional disruption can cause type 2 diabetes. The clinical relevance of these findings is highlighted by recent reports of very strong association of the rs7944584 single nucleotide polymorphism (SNP) of IG20/MADD with fasting hyperglycemia/diabetes. Thus, IG20/MADD could be a therapeutic target for type 2 diabetes, particularly in those with the rs7944584 SNP.


Assuntos
Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Hiperglicemia/metabolismo , Insulina/metabolismo , Animais , Apoptose/fisiologia , Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/genética , Diabetes Mellitus Tipo 2/genética , Teste de Tolerância a Glucose , Fatores de Troca do Nucleotídeo Guanina/genética , Hiperglicemia/genética , Resistência à Insulina/fisiologia , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Camundongos , Camundongos Knockout
12.
PLoS One ; 8(2): e56817, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23457619

RESUMO

The Map kinase Activating Death Domain containing protein (MADD) isoform of the IG20 gene is over-expressed in different types of cancer tissues and cell lines and it functions as a negative regulator of apoptosis. Therefore, we speculated that MADD might be over-expressed in human breast cancer tissues and that MADD knock-down might synergize with chemotherapeutic or TRAIL-induced apoptosis of breast cancer cells. Analyses of breast tissue microarrays revealed over-expression of MADD in ductal and invasive carcinomas relative to benign tissues. MADD knockdown resulted in enhanced spontaneous apoptosis in human breast cancer cell lines. Moreover, MADD knockdown followed by treatment with TRAIL or doxorubicin resulted in increased cell death compared to either treatment alone. Enhanced cell death was found to be secondary to increased caspase-8 activation. These data indicate that strategies to decrease MADD expression or function in breast cancer may be utilized to increase tumor cell sensitivity to TRAIL and doxorubicin induced apoptosis.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/patologia , Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/deficiência , Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/genética , Doxorrubicina/farmacologia , Técnicas de Silenciamento de Genes , Fatores de Troca do Nucleotídeo Guanina/deficiência , Fatores de Troca do Nucleotídeo Guanina/genética , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Sequência de Aminoácidos , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/química , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Fatores de Troca do Nucleotídeo Guanina/química , Humanos , Dados de Sequência Molecular , RNA Interferente Pequeno/genética , Receptores de Morte Celular/metabolismo
13.
Thyroid ; 23(1): 70-8, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22998497

RESUMO

BACKGROUND: The IG20/MADD gene is overexpressed in thyroid cancer tissues and cell lines, and can contribute to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance. The ability of the MADD protein to resist TRAIL-induced apoptosis is dependent upon its phosphorylation by Akt. Interestingly, while TRAIL induces a significant reduction in the levels of phospho-Akt (pAkt) and phospho-MADD (pMADD) in TRAIL-sensitive cells, it fails to do so in TRAIL-resistant cells. In this study, we investigated if MADD phosphorylation by Akt was contributing to TRAIL resistance in thyroid cancer cells. METHODS: We determined the susceptibility of different thyroid cancer cell lines to TRAIL-induced apoptosis by fluorescence-activated cell sorting (FACS) analysis. We tested for various TRAIL resistance factors by FACS analyses or for IG20/MADD expression by quantitative reverse transcription-polymerase chain reaction. We determined the levels of pAkt and pMADD upon TRAIL treatment in thyroid cancer cells by Western blotting. We tested if down-modulation of IG20/MADD gene expression using shRNA or phosphorylation using a dominant negative Akt (DN-Akt) or pretreatment with LY294002, a PI3 kinase inhibitor, could help overcome TRAIL resistance. RESULT: BCPAP and TPC1 cells were susceptible, while KTC1 and FTC133 cells were resistant, to TRAIL-induced apoptosis. The differential susceptibility to TRAIL was not related to the levels of expression of death receptors, decoy receptors, or TRAIL. KTC1 and FTC133 cells showed higher levels of IG20/MADD expression relative to BCPAP and TPC1, and were rendered susceptible to TRAIL treatment upon IG20/MADD knockdown. Interestingly, upon TRAIL treatment, the pAkt and pMADD levels were reduced in TRAIL-sensitive BCPAP and TPC1 cells, while they remained unchanged in the resistant KTC1 and FTC133 cells. While expression of a constitutively active Akt in BCPAP and TPC1 cells rendered them resistant to TRAIL, pretreating KTC1 and FTC133 cells with LY294002 rendered them TRAIL-sensitive. Moreover, expression of a DN-Akt in KTC1 and FTC133 cells reduced the levels of pAkt and pMADD and sensitized them to TRAIL-induced apoptosis. CONCLUSION: Our results show that pMADD is an important TRAIL resistance factor in certain thyroid cancer cells and suggest that down-modulation of either IG20/MADD expression or phosphorylation can render TRAIL-resistant thyroid cancer cells sensitive to TRAIL.


Assuntos
Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/antagonistas & inibidores , Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/genética , Fatores de Troca do Nucleotídeo Guanina/antagonistas & inibidores , Fatores de Troca do Nucleotídeo Guanina/genética , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Neoplasias da Glândula Tireoide/tratamento farmacológico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Cromonas/farmacologia , Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/metabolismo , Resistencia a Medicamentos Antineoplásicos , Inibidores Enzimáticos/farmacologia , Técnicas de Silenciamento de Genes , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Humanos , Morfolinas/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Interferente Pequeno/genética , Receptores de Morte Celular/genética , Proteínas Recombinantes/farmacologia , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia , Receptores Chamariz do Fator de Necrose Tumoral/genética
14.
Am J Obstet Gynecol ; 205(4): 362.e12-25, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21855847

RESUMO

OBJECTIVE: The clinical utility of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in the treatment of established human malignancies is limited by the development of resistance to TRAIL. We hypothesized that knockdown of map-kinase activating death domain containing protein (MADD), a TRAIL-resistance factor, may overcome TRAIL resistance in ovarian cancer cells. STUDY DESIGN: MADD expression in resected ovarian cancer specimens and cell lines was quantified with the use of polymerase chain reaction. Sensitivity of ovarian cancer cell lines to TRAIL, with or without MADD knockdown, was assessed. RESULTS: MADD is expressed at relatively higher levels in human malignant ovarian cancer tissues and cell lines, compared with normal ovarian tissues. The cell lines OVCA429 and OVCAR3 were susceptible, and cell lines CAOV-3 and SKOV-3 were resistant to TRAIL. MADD knockdown in CAOV-3 cells, but not in SKOV-3 cells, conferred TRAIL sensitivity. Knockdown of cellular Fas-associated death domain-like interleukin-1 beta-converting enzyme-inhibitory protein (c-FLIP) in SKOV-3 cells increased spontaneous and TRAIL-induced apoptosis, which was further increased on MADD knockdown. CONCLUSION: MADD/c-FLIP(L) knockdown can render TRAIL-resistant ovarian cancer cells susceptible to TRAIL.


Assuntos
Apoptose/fisiologia , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/fisiologia , Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/fisiologia , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Neoplasias Ovarianas/patologia , Ligante Indutor de Apoptose Relacionado a TNF/fisiologia , Feminino , Humanos , Células Tumorais Cultivadas
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