Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Tipo de estudo
Intervalo de ano de publicação
1.
Interv Neuroradiol ; : 1591019919901037, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992106

RESUMO

OBJECTIVE: To investigate factors affecting recurrence and effects and safety of endovascular retreatment for aneurysms recurrent after embolization. METHODS: Among 815 aneurysms treated with embolization, recurrence was in 114 aneurysms (14.0%). Forty-three recurrent aneurysms were managed with re-embolization. Procedural complications, angiographic, and clinical results of retreatment were analyzed. RESULTS: Patients with recurrent aneurysms were significantly (P < 0.01) younger than without recurrence (51.09 ± 10.46 vs. 53.88 ± 9.61 years). Recurrent aneurysms (n = 114) were significantly (P = 0.00) greater (11.12 ± 8.35 vs. 5.81 ± 3.44 mm) with a significantly (P = 0.00) greater neck (4.34 ± 2.26 vs. 2.90 ± 1.44 mm) than without recurrence. The rupture status of aneurysms significantly (P = 0.00) affected recurrence at follow-up. Significantly (P = 0.00) more aneurysms without recurrence were treated with advanced embolization techniques (81.0% vs. 62.3%) and got complete occlusion at the first embolization than those with recurrence (93.7% vs. 36.8%). In treating 43 recurrent aneurysms, stent-assisted recoiling was used in 48.8% in the first retreatment and 50% in the second and third retreatment procedures. Angiographic follow-up in 38 (88.4%) cases showed complete or near complete occlusion in 30 aneurysms, with the rest eight aneurysms experiencing a second recurrence (21.1%). Of the eight aneurysms with the second recurrence, five underwent the second endovascular retreatment, with complete aneurysm occlusion achieved in three cases (60%), near-complete occlusion in one (20%), and incomplete occlusion in one case at immediate angiography and six-month follow-up. Procedure-related complications occurred in three patients. CONCLUSIONS: Endovascular retreatment of recurrent previously coiled aneurysms is safe and effective even though advanced embolization techniques are frequently involved especially for large and giant aneurysms.

2.
Sci China Life Sci ; 61(2): 235-243, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28895115

RESUMO

The SU(VAR)-3-9-related protein family member SUVR2 has been previously identified to be involved in transcriptional gene silencing both in RNA-dependent and -independent pathways. It interacts with the chromatin-remodeling proteins CHR19, CHR27, and CHR28 (CHR19/27/28), which are also involved in transcriptional gene silencing. Here our study demonstrated that SUVR2 is almost fully mono-sumoylated in vivo. We successfully identified the exact SUVR2 sumoylation site by combining in vitro mass spectrometric analysis and in vivo immunoblotting confirmation. The luminescence imaging assay and quantitative RT-PCR results demonstrated that SUVR2 sumoylation is involved in transcriptional gene silencing. Furthermore, we found that SUVR2 sumoylation is required for the interaction of SUVR2 with CHR19/27/28, which is consistent with the fact that SUMO proteins are necessary for transcriptional gene silencing. These results suggest that SUVR2 sumoylation contributes to transcriptional gene silencing by facilitating the interaction of SUVR2 with the chromatin-remodeling proteins CHR19/27/28.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Sumoilação , Proteínas de Arabidopsis/genética , Montagem e Desmontagem da Cromatina/genética , Immunoblotting , Espectrometria de Massas , Mutação , Proteínas Nucleares/metabolismo , Plantas Geneticamente Modificadas , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/genética , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo
3.
Biochem Biophys Res Commun ; 495(1): 1041-1047, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29162449

RESUMO

Protein disulfide isomerases (PDIs) can catalyze disulfide bond formation in nascent secretory proteins and membrane proteins and can introduce correct disulfide bonds into substrate proteins containing mispaired disulfides. The functions of mammalian PDIs have been extensively studied; however, relative to mammalian PDIs, the systematic characterization of PDIs for their oxidoreductase activity in plants is still lacking. Arabidopsis protein disulfide isomerases-11 (AtPDI11), with the structure of a-a'-D, has no ortholog in animals or yeast. In this study, we demonstrated that AtPDI11 has oxidoreductase activity in vitro using a GSSG/GSH-mediated oxidative protein folding system. Moreover, the active site in the a' domain of AtPDI11 is critical for its oxidative folding activity. AtPDI11 is present in four redox forms in vivo, which are determined by the active site cysteines (Cys52 and Cys55 in the a domain, and Cys171 and Cys174 in the a' domain). Genetic evidence suggests that AtPDI11 is required for plant growth under reducing conditions. Our work provides an example for studying the oxidoreductase function of other plant PDIs.


Assuntos
Arabidopsis/enzimologia , Arabidopsis/crescimento & desenvolvimento , Isomerases de Dissulfetos de Proteínas/química , Isomerases de Dissulfetos de Proteínas/metabolismo , Dobramento de Proteína , Arabidopsis/genética , Sítios de Ligação , Ativação Enzimática , Oxirredução , Ligação Proteica , Isomerases de Dissulfetos de Proteínas/ultraestrutura , Domínios Proteicos , Relação Estrutura-Atividade
4.
Plant Cell ; 29(1): 70-89, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28082384

RESUMO

Cell-to-cell communication precisely controls the creation of new organs during reproductive growth. However, the sensor molecules that mediate developmental signals in monocot plants are poorly understood. Here, we report that DWARF AND RUNTISH SPIKELET1 (DRUS1) and DRUS2, two closely related receptor-like kinases (RLKs), redundantly control reproductive growth and development in rice (Oryza sativa). A drus1-1 drus2 double knockout mutant, but not either single mutant, showed extreme dwarfism and barren inflorescences that harbored sterile spikelets. The gibberellin pathway was not impaired in this mutant. A phenotypic comparison of mutants expressing different amounts of DRUS1 and 2 revealed that reproductive growth requires a threshold level of DRUS1/2 proteins. DRUS1 and 2 maintain cell viability by repressing protease-mediated cell degradation and likely by affecting sugar utilization or conversion. In the later stages of anther development, survival of the endothecium requires DRUS1/2, which may stimulate expression of the UDP-glucose pyrophosphorylase gene UGP2 and starch biosynthesis in pollen. Unlike their Arabidopsis thaliana ortholog FERONIA, DRUS1 and 2 mediate a fundamental signaling process that is essential for cell survival and represents a novel biological function for the CrRLK1L RLK subfamily.


Assuntos
Metabolismo dos Carboidratos/genética , Oryza/genética , Proteínas de Plantas/genética , Receptores Proteína Tirosina Quinases/genética , Sequência de Aminoácidos , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Morte Celular/genética , Flores/enzimologia , Flores/genética , Flores/ultraestrutura , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Immunoblotting , Hibridização In Situ , Microscopia Confocal , Microscopia Eletrônica , Oryza/enzimologia , Fosfotransferases/genética , Fosfotransferases/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Interferência de RNA , Receptores Proteína Tirosina Quinases/metabolismo , Reprodução/genética , Homologia de Sequência de Aminoácidos , Amido/metabolismo
5.
Plant Cell ; 28(5): 1215-29, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27113777

RESUMO

The mechanism by which MORPHEUS' MOLECULE1 (MOM1) contributes to transcriptional gene silencing has remained elusive since the gene was first identified and characterized. Here, we report that two Arabidopsis thaliana PIAS (PROTEIN INHIBITOR OF ACTIVATED STAT)-type SUMO E3 ligase-like proteins, PIAL1 and PIAL2, function redundantly to mediate transcriptional silencing at MOM1 target loci. PIAL1 and PIAL2 physically interact with each other and with MOM1 to form a high molecular mass complex. In the absence of either PIAL2 or MOM1, the formation of the high molecular mass complex is disrupted. We identified a previously uncharacterized IND (interacting domain) in PIAL1 and PIAL2 and demonstrated that IND directly interacts with MOM1. The CMM2 (conserved MOM1 motif 2) domain of MOM1 was previously shown to be required for the dimerization of MOM1. We demonstrated that the CMM2 domain is also required for the interaction of MOM1 with PIAL1 and PIAL2. We found that although PIAL2 has SUMO E3 ligase activity, the activity is dispensable for PIAL2's function in transcriptional silencing. This study suggests that PIAL1 and PIAl2 act as components of the MOM1-containing complex to mediate transcriptional silencing at heterochromatin regions.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , ATPases Associadas a Diversas Atividades Celulares , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Proteínas Nucleares/genética , Ligação Proteica , Fatores de Transcrição/genética
6.
PLoS One ; 10(6): e0129137, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26053632

RESUMO

MMS19 is an essential component of the cytoplasmic iron-sulfur (Fe-S) cluster assembly complex in fungi and mammals; the mms19 null mutant alleles are lethal. Our study demonstrates that MMS19/MET18 in Arabidopsis thaliana interacts with the cytoplasmic Fe-S cluster assembly complex but is not an essential component of the complex. We find that MMS19 also interacts with the catalytic subunits of DNA polymerases, which have been demonstrated to be involved in transcriptional gene silencing (TGS), DNA repair, and flowering time regulation. Our results indicate that MMS19 has a similar biological function, suggesting a functional link between MMS19 and DNA polymerases. In the mms19 null mutant, the assembly of Fe-S clusters on the catalytic subunit of DNA polymerase α is reduced but not blocked, which is consistent with the viability of the mutant. Our study suggests that MMS19 assists the assembly of Fe-S clusters on DNA polymerases in the cytosol, thereby facilitating transcriptional gene silencing, DNA repair, and flowering time control.


Assuntos
Arabidopsis/genética , Arabidopsis/metabolismo , Reparo do DNA , Flores , Inativação Gênica , Proteínas com Ferro-Enxofre/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Transporte/metabolismo , Catálise , Elementos de DNA Transponíveis , DNA Polimerase Dirigida por DNA/metabolismo , Regulação da Expressão Gênica de Plantas , Espaço Intracelular/metabolismo , Complexos Multiproteicos , Mutação , Ligação Proteica , Transcrição Genética
7.
Korean J Radiol ; 15(6): 850-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25469099

RESUMO

OBJECTIVE: Tiny cerebral aneurysms are difficult to embolize because the aneurysm's sac is too small for a single small coil, and coils within the aneurysm may escape from the confinement of a stent. This study was performed to introduce the stent-assisted coil-jailing technique and to investigate its effect on the coil embolization of tiny intracranial aneurysms. MATERIALS AND METHODS: Sixteen patients with tiny intracranial aneurysms treated with the stent-assisted coil-jailing technique between January 2011 and December 2013 were retrospectively reviewed and followed-up. RESULTS: All aneurysms were successfully treated with the coil-jailing technique, and at the end of embolization, complete occlusion of the aneurysm was achieved in 9 cases (56.3%), incomplete occlusion in 6 (37.5%), and partial occlusion in 1 (6.3%). Intraprocedural complications included acute thrombosis in one case (6.3%) and re-rupture in another (6.3%). Both complications were managed appropriately with no sequela. Follow-up was performed in all patients for 3-24 months (mean, 7.7 months) after embolization. Complete occlusion was sustained in the 9 aneurysms with initial complete occlusion, progressive thrombosis to complete occlusion occurred in the 6 aneurysms with initial near-complete occlusion, and one aneurysm resulted in progressive thrombosis to complete occlusion after initial partial occlusion. No migration of stents or coils occurred at follow-up as compared with their positions immediately after embolization. At follow-up, all patients had recovered with no sequela. CONCLUSION: The stent-assisted coil-jailing technique can be an efficient approach for tiny intracranial aneurysms, even though no definite conclusion regarding its safety can be drawn from the current data.


Assuntos
Embolização Terapêutica/instrumentação , Aneurisma Intracraniano/terapia , Adulto , Idoso , Angiografia Cerebral , Feminino , Seguimentos , Humanos , Aneurisma Intracraniano/patologia , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Índice de Gravidade de Doença , Stents , Resultado do Tratamento
8.
Interv Neuroradiol ; 20(6): 669-76, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25496676

RESUMO

Aneurysms with an acutely angled parent artery are difficult to access for coiling. This study aimed to investigate the safety and effectiveness of microcatheter looping for embolization of cerebral aneurysms with access difficulty. Ten patients (male:female=5:5) with cerebral aneurysms treated with the microcatheter looping technique were analyzed retrospectively. The parent artery formed an acute angle with the major artery in five aneurysms. The microcatheter was looped into a "α" loop for treatment in the anterior temporal artery aneurysm and a "U" loop in the remaining nine aneurysms. All ten aneurysms were successfully treated with the microcatheter looping technique. The microcatheter tip was successfully navigated into the aneurysm sac and remained stable throughout the embolization process. All aneurysms were occluded with total occlusion in five and near-total occlusion in five, and the parent artery remained patent in all cases. No complications occurred peri-procedurally. The Glasgow Outcome Scale was 5 in all patients before discharge. Follow-up angiography six to 12 months later revealed a good occlusion status of the aneurysms. The microcatheter looping technique is effective when the conventional embolization technique fails to treat cerebral aneurysms with difficult access especially when the parent artery forming an acute angle with the major artery exacerbates difficult access to the aneurysms.


Assuntos
Cateterismo Venoso Central/métodos , Artérias Cerebrais/diagnóstico por imagem , Embolização Terapêutica/métodos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/terapia , Adulto , Idoso , Cateteres , Angiografia Cerebral , Feminino , Seguimentos , Escala de Resultado de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Resultado do Tratamento
9.
Cell Res ; 24(12): 1445-65, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25420628

RESUMO

The SU(VAR)3-9-like histone methyltransferases usually catalyze repressive histone H3K9 methylation and are involved in transcriptional gene silencing in eukaryotic organisms. We identified a putative SU(VAR)3-9-like histone methyltransferase SUVR2 by a forward genetic screen and demonstrated that it is involved in transcriptional gene silencing at genomic loci targeted by RNA-directed DNA methylation (RdDM). We found that SUVR2 has no histone methyltransferase activity and the conserved catalytic sites of SUVR2 are dispensable for the function of SUVR2 in transcriptional silencing. SUVR2 forms a complex with its close homolog SUVR1 and associate with three previously uncharacterized SNF2-related chromatin-remodeling proteins CHR19, CHR27, and CHR28. SUVR2 was previously thought to be a component in the RdDM pathway. We demonstrated that SUVR2 contributes to transcriptional gene silencing not only at a subset of RdDM target loci but also at many RdDM-independent target loci. Our study suggests that the involvement of SUVR2 in transcriptional gene silencing is related to nucleosome positioning mediated by its associated chromatin-remodeling proteins.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Arabidopsis/metabolismo , Metilação de DNA , Loci Gênicos , Histonas/metabolismo , Ativação Transcricional
10.
Plant Cell ; 26(6): 2538-2553, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24907341

RESUMO

High salinity causes growth inhibition and shoot bleaching in plants that do not tolerate high salt (glycophytes), including most crops. The molecules affected directly by salt and linking the extracellular stimulus to intracellular responses remain largely unknown. Here, we demonstrate that rice (Oryza sativa) Salt Intolerance 1 (SIT1), a lectin receptor-like kinase expressed mainly in root epidermal cells, mediates salt sensitivity. NaCl rapidly activates SIT1, and in the presence of salt, as SIT1 kinase activity increased, plant survival decreased. Rice MPK3 and MPK6 function as the downstream effectors of SIT1. SIT1 phosphorylates MPK3 and 6, and their activation by salt requires SIT1. SIT1 mediates ethylene production and salt-induced ethylene signaling. SIT1 promotes accumulation of reactive oxygen species (ROS), leading to growth inhibition and plant death under salt stress, which occurred in an MPK3/6- and ethylene signaling-dependent manner in Arabidopsis thaliana. Our findings demonstrate the existence of a SIT1-MPK3/6 cascade that mediates salt sensitivity by affecting ROS and ethylene homeostasis and signaling. These results provide important information for engineering salt-tolerant crops.

11.
Mol Med Rep ; 9(4): 1225-31, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24567055

RESUMO

Previous studies have demonstrated that progesterone has neuroprotective effects in the central nervous system (CNS) following traumatic brain injury (TBI). Numerous cellular mechanisms have been reported to be important in the neuroprotective effects of progesterone, including the reduction of edema, inflammation and apoptosis, and the inhibition of oxidative stress. However, the effect of progesterone on neuronal protection following TBI remains unclear. The present study aimed to investigate the effects of progesterone on the expression of Nogo-A, an inhibitor of axonal growth, glial fibrillary acidic protein (GFAP), a main component of the glial scar and growth-associated protein-43 (GAP-43), a signaling molecule in neuronal growth in TBI rats. The TBI model was produced by the weight drop method. In total, 75 rats were assigned to three groups: the sham group, TBI group with vehicle treatment and TBI group with progesterone treatment. The protein expression of Nogo-A, GFAP and GAP-43 in the cortex and the hippocampus was examined by immunocytochemistry. TBI rats significantly increased the expression of Nogo-A, GFAP, and GAP-43 at 1, 3, 7 and 14 days post-injury. Progesterone significantly decreased the expression of Nogo-A and GFAP, and upregulated the GAP-43 protein. Our findings suggested that progesterone promotes neuroprotection following TBI by inhibiting the expression of Nogo-A and GFAP, and increasing GAP-43 expression.


Assuntos
Lesões Encefálicas/metabolismo , Proteína GAP-43/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Proteínas da Mielina/metabolismo , Progesterona/farmacologia , Animais , Lesões Encefálicas/patologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/patologia , Masculino , Proteínas Nogo , Ratos , Ratos Sprague-Dawley
12.
J Surg Res ; 182(2): e69-77, 2013 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-23207171

RESUMO

BACKGROUND: Neurite outgrowth inhibitor-A (Nogo-A), myelin-associated glycoprotein, and oligodendrocyte myelin glycoprotein are three myelin-associated proteins that act as inhibitors to central nervous system regeneration. Neurite outgrowth inhibitor-A imposes the strongest effect on inhibiting axonal regeneration after traumatic brain injury. Alpha-tocopherol, a member of the vitamin E family, is recognized as an active antioxidative substance. Its use has not been well studied in brain injury research, especially in axonal regeneration research. METHODS: We obtained 99 intact adult male Sprague-Dawley rats (200-250 g) from the Experimental Animal Center of Central South University. We used the modified method of Freeney to generate moderate brain injury in the rats. We injected 600 mg/kg α-tocopherol intraperitoneally daily as traumatic brain injury (TBI) treatment. Then, we performed behavioral tests in the corresponding time point, examined brain tissues after hematoxylin-eosin staining to identify changes in cell morphology, and performed immunohistochemical staining and quantitative real-time polymerase chain reaction to detect the expression of NoGo and Nogo receptor (NgR) in brain tissue. RESULTS: For the Neurological Severity Scores of rats, there were obvious differences among the three groups at the corresponding time points. Standard hematoxylin-eosin staining showed that the brain structure of a sham-operated group of rats was clear, uniform, and compact. A TBI group exhibited hemorrhage, edema, inflammatory cell infiltration, condensed nuclei, and necrosis. We also saw glial cells and fibrous tissue proliferation. The α-tocopherol-treated TBI group had similar but less severe changes than the TBI group. Expression of Nogo-A and NgR increased after TBI compared with the sham-operated group. However, Nogo-A and NgR expression was significantly lower in the α-tocopherol-treated TBI group compared with the TBI group. Similarly, results showed that functional neurological deficits among rats in the α-tocopherol-treated TBI group were less pronounced than in the TBI group (model group). CONCLUSIONS: Our data demonstrate that α-tocopherol-treated rats had reduced microscopic evidence of brain damage. Alpha-tocopherol reduced Nogo-A and NgR expression in brain tissue after traumatic brain injury and promoted nerve regeneration. Alpha-tocopherol treatment of TBI rats had a neuroprotective role in their recovery.


Assuntos
Química Encefálica/efeitos dos fármacos , Lesões Encefálicas/tratamento farmacológico , Proteínas da Mielina/análise , Receptores de Superfície Celular/análise , alfa-Tocoferol/uso terapêutico , Animais , Encéfalo/patologia , Lesões Encefálicas/metabolismo , Lesões Encefálicas/fisiopatologia , Proteínas Ligadas por GPI/análise , Proteínas Ligadas por GPI/genética , Imuno-Histoquímica , Masculino , Proteínas da Mielina/genética , Fármacos Neuroprotetores/farmacologia , Proteínas Nogo , Receptor Nogo 1 , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Receptores de Superfície Celular/genética , alfa-Tocoferol/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA