Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Mol Cell ; 84(18): 3438-3454.e8, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39232583

RESUMO

Spreading of H3K27me3 is crucial for the maintenance of mitotically inheritable Polycomb-mediated chromatin silencing in animals and plants. However, how Polycomb repressive complex 2 (PRC2) accesses unmodified nucleosomes in spreading regions for spreading H3K27me3 remains unclear. Here, we show in Arabidopsis thaliana that the chromatin remodeler PICKLE (PKL) plays a specialized role in H3K27me3 spreading to safeguard cell identity during differentiation. PKL specifically localizes to H3K27me3 spreading regions but not to nucleation sites and physically associates with PRC2. Loss of PKL disrupts the occupancy of the PRC2 catalytic subunit CLF in spreading regions and leads to aberrant dedifferentiation. Nucleosome density increase endowed by the ATPase function of PKL ensures that unmodified nucleosomes are accessible to PRC2 catalytic activity for H3K27me3 spreading. Our findings demonstrate that PKL-dependent nucleosome compaction is critical for PRC2-mediated H3K27me3 read-and-write function in H3K27me3 spreading, thus revealing a mechanism by which repressive chromatin domains are established and propagated.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Diferenciação Celular , Montagem e Desmontagem da Cromatina , Histonas , Nucleossomos , Complexo Repressor Polycomb 2 , Nucleossomos/metabolismo , Nucleossomos/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Histonas/metabolismo , Histonas/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Complexo Repressor Polycomb 2/metabolismo , Complexo Repressor Polycomb 2/genética , Regulação da Expressão Gênica de Plantas , Cromatina/metabolismo , Cromatina/genética
2.
Plant Cell ; 35(7): 2464-2483, 2023 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-37062961

RESUMO

Switch defective/sucrose nonfermentable (SWI/SNF) complexes are evolutionarily conserved multisubunit machines that play vital roles in chromatin architecture regulation for modulating gene expression via sliding or ejection of nucleosomes in eukaryotes. In plants, perturbations of SWI/SNF subunits often result in severe developmental disorders. However, the subunit composition, pathways of assembly, and genomic targeting of the plant SWI/SNF complexes are poorly understood. Here, we report the organization, genomic targeting, and assembly of 3 distinct SWI/SNF complexes in Arabidopsis thaliana: BRAHMA-Associated SWI/SNF complexes (BAS), SPLAYED-Associated SWI/SNF complexes (SAS), and MINUSCULE-Associated SWI/SNF complexes (MAS). We show that BAS complexes are equivalent to human ncBAF, whereas SAS and MAS complexes evolve in multiple subunits unique to plants, suggesting plant-specific functional evolution of SWI/SNF complexes. We further show overlapping and specific genomic targeting of the 3 plant SWI/SNF complexes on chromatin and reveal that SAS complexes are necessary for the correct genomic localization of the BAS complexes. Finally, we define the role of the core module subunit in the assembly of plant SWI/SNF complexes and highlight that ATPase module subunit is required for global complex stability and the interaction of core module subunits in Arabidopsis SAS and BAS complexes. Together, our work highlights the divergence of SWI/SNF chromatin remodelers during eukaryote evolution and provides a comprehensive landscape for understanding plant SWI/SNF complex organization, assembly, genomic targeting, and function.


Assuntos
Arabidopsis , Humanos , Arabidopsis/genética , Arabidopsis/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Montagem e Desmontagem da Cromatina/genética , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Cromatina/genética , Cromatina/metabolismo , Genômica
3.
Plant Cell ; 34(10): 3915-3935, 2022 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-35866997

RESUMO

PICKLE (PKL) is a chromodomain helicase DNA-binding domain 3 (CHD3) chromatin remodeler that plays essential roles in controlling the gene expression patterns that determine developmental identity in plants, but the molecular mechanisms through which PKL is recruited to its target genes remain elusive. Here, we define a cis-motif and trans-acting factors mechanism that governs the genomic occupancy profile of PKL in Arabidopsis thaliana. We show that two homologous trans-factors VIVIPAROUS1/ABI3-LIKE1 (VAL1) and VAL2 physically interact with PKL in vivo, localize extensively to PKL-occupied regions in the genome, and promote efficient PKL recruitment at thousands of target genes, including those involved in seed maturation. Transcriptome analysis and genetic interaction studies reveal a close cooperation of VAL1/VAL2 and PKL in regulating gene expression and developmental fate. We demonstrate that this recruitment operates at two master regulatory genes, ABSCISIC ACID INSENSITIVE3 and AGAMOUS-LIKE 15, to repress the seed maturation program and ensure the seed-to-seedling transition. Together, our work unveils a general rule through which the CHD3 chromatin remodeler PKL binds to its target chromatin in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ácido Abscísico/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cromatina/genética , Cromatina/metabolismo , DNA/metabolismo , DNA Helicases/genética , DNA Helicases/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Sementes/genética , Transativadores/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
4.
Langmuir ; 39(40): 14328-14335, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37748943

RESUMO

Micro/nanospherical lens photolithography (SLPL) constitutes an efficient and precise micro/nanofabrication methodology. It offers advantages over traditional nanolithography approaches, such as cost-effectiveness and ease of implementation. By using micrometer-sized microspheres, SLPL enables the preparation of subwavelength scale features. This technique has gained attention due to its potential applications. However, the SLPL process has a notable limitation in that it mostly produces simple pattern shapes, mainly consisting of circular arrays. There has been a lack of theoretical analysis regarding the possible shapes that can be created. In our experiments, we successfully prepared annular and ring-with-hole pattern shapes. To address this limitation, we applied the Mie scattering theory to systematically analyze and summarize the various patterns that can be obtained through the SLPL process. We also proposed methods to predict and obtain different patterns. This theoretical analysis enhances the understanding of SLPL and expands its potential applications, making it a valuable area for further research.

5.
Nucleic Acids Res ; 49(1): 98-113, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33270882

RESUMO

The Polycomb repressive complex 2 (PRC2) catalyzes histone H3 Lys27 trimethylation (H3K27me3) to repress gene transcription in multicellular eukaryotes. Despite its importance in gene silencing and cellular differentiation, how PRC2 is recruited to target loci is still not fully understood. Here, we report genome-wide evidence for the recruitment of PRC2 by the transcriptional repressors VIVIPAROUS1/ABI3-LIKE1 (VAL1) and VAL2 in Arabidopsis thaliana. We show that the val1 val2 double mutant possesses somatic embryonic phenotypes and a transcriptome strikingly similar to those of the swn clf double mutant, which lacks the PRC2 catalytic subunits SWINGER (SWN) and CURLY LEAF (CLF). We further show that VAL1 and VAL2 physically interact with SWN and CLF in vivo. Genome-wide binding profiling demonstrated that they colocalize with SWN and CLF at PRC2 target loci. Loss of VAL1/2 significantly reduces SWN and CLF enrichment at PRC2 target loci and leads to a genome-wide redistribution of H3K27me3 that strongly affects transcription. Finally, we provide evidence that the VAL1/VAL2-RY regulatory system is largely independent of previously identified modules for Polycomb silencing in plants. Together, our work demonstrates an extensive genome-wide interaction between VAL1/2 and PRC2 and provides mechanistic insights into the establishment of Polycomb silencing in plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Complexo Repressor Polycomb 2/metabolismo , Proteínas Repressoras/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Repressão Epigenética , Ontologia Genética , Histonas/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Complexo Repressor Polycomb 2/genética , Ligação Proteica , Mapeamento de Interação de Proteínas , Proteínas Repressoras/deficiência , Proteínas Repressoras/genética , Elementos de Resposta/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica
6.
Plant J ; 101(2): 310-323, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31536657

RESUMO

Seed is vital to the conservation of germplasm and plant biodiversity. Seed dormancy is an adaptive trait in numerous seed-plant species, enabling plants to survive under stressful conditions. Seed dormancy is mainly controlled by abscisic acid (ABA) and gibberellin (GA) and can be classified as primary and secondary seed dormancy. The primary seed dormancy is induced by maternal ABA. Here we found that AtPER1, a seed-specific peroxiredoxin, is involved in enhancing primary seed dormancy. Two loss-of-function atper1 mutants, atper1-1 and atper1-2, displayed suppressed primary seed dormancy accompanied with reduced ABA and increased GA contents in seeds. Furthermore, atper1 mutant seeds were insensitive to abiotic stresses during seed germination. The expression of several ABA catabolism genes (CYP707A1, CYP707A2, and CYP707A3) and GA biosynthesis genes (GA20ox1, GA20ox3, and KAO3) in atper1 mutant seeds was increased compared to wild-type seeds. The suppressed primary seed dormancy of atper1-1 was completely reduced by deletion of CYP707A genes. Furthermore, loss-of-function of AtPER1 cannot enhance the seed germination ratio of aba2-1 or ga1-t, suggesting that AtPER1-enhanced primary seed dormancy is dependent on ABA and GA. Additionally, the level of reactive oxygen species (ROS) in atper1 mutant seeds was significantly higher than that in wild-type seeds. Taken together, our results demonstrate that AtPER1 eliminates ROS to suppress ABA catabolism and GA biosynthesis, and thus improves the primary seed dormancy and make the seeds less sensitive to adverse environmental conditions.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Germinação/fisiologia , Giberelinas/metabolismo , Dormência de Plantas/fisiologia , Sementes/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Regulação da Expressão Gênica de Plantas , Germinação/genética , Mutação , Fenótipo , Dormência de Plantas/genética , Reguladores de Crescimento de Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas , Espécies Reativas de Oxigênio/metabolismo , Plântula/genética , Plântula/metabolismo , Sementes/genética , Transcriptoma
7.
Plant Physiol ; 184(4): 1969-1978, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33037128

RESUMO

Seed dormancy is an adaptive trait that is crucial to plant survival. Abscisic acid (ABA) is the primary phytohormone that induces seed dormancy. However, little is known about how the level of ABA in seeds is determined. Here we show that the Arabidopsis (Arabidopsis thaliana) H3K27me3 demethylase RELATIVE OF EARLY FLOWERING6 (REF6) suppresses seed dormancy by inducing ABA catabolism in seeds. Seeds of the ref6 loss-of-function mutants displayed enhanced dormancy that was associated with increased endogenous ABA content. We further show that the transcripts of two genes key to ABA catabolism, CYP707A1 and CYP707A3, but not genes involved in ABA biosynthesis, were significantly reduced in ref6 mutants during seed development and germination. In developing siliques, REF6 bound directly to CYP707A1 and CYP707A3, and was responsible for reducing their H3K27me3 levels. Genetic analysis demonstrated that the enhanced seed dormancy and ABA concentration in ref6 depended mainly on the reduced expression of CYP707A1 and CYP707A3 Conversely, overexpression of CYP707A1 could offset the enhanced seed dormancy of ref6 Taken together, our results revealed an epigenetic regulation mechanism that is involved in the regulation of ABA content in seeds.


Assuntos
Ácido Abscísico/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Epigênese Genética , Germinação/genética , Dormência de Plantas/genética , Dormência de Plantas/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas
8.
Endocr Pract ; 27(7): 661-667, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34250908

RESUMO

OBJECTIVE: To evaluate the 2015 American Thyroid Association (ATA) guidelines and 2017 American College of Radiology (ACR) Thyroid Imaging, Reporting and Data System (TI-RADS) for their efficacy in predicting malignant thyroid nodules and safety in recommending fine needle aspiration (FNA). METHODS: We reviewed data of 970 thyroid nodules from 908 patients with core needle biopsy pathology. We calculated the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for each guideline to predict malignancies. We compared the areas under the curve and FNA recommendations between the 2 guidelines. RESULTS: According to the core needle biopsy pathology, 59.9% (581/970) of the thyroid nodules were malignant. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value was 68%, 91%, 33%, 67%, and 70%, respectively, for the ATA guidelines and 70%, 84%, 49%, 71%, and 68%, respectively, for the ACR TI-RADS. Areas under the curve (ATA: 0.71 vs ACR TI-RADS: 0.74; P = .054) were similar when predicting malignancies. For the 545 nodules with maximum diameter ≥1.0 cm, the ACR TI-RADS recommended FNA less often than the ATA guidelines (83.3% [454/545] vs 87.7% [478/545]; P = .01). For the 321 malignant nodules with maximum diameter ≥1.0 cm, the proportions of FNA recommendations were not significantly different (ACR TI-RADS: 90.7% [291/321] vs ATA: 92.5% [297/321]; P = .06). CONCLUSION: The 2015 ATA guidelines and 2017 ACR TI-RADS showed a similar ability in predicting malignancies. Reducing FNA recommendations by the ACR TI-RADS would not lead to a significant decrease in the FNA recommendations given for malignancies with maximum diameter ≥1.0 cm.


Assuntos
Radiologia , Nódulo da Glândula Tireoide , Sistemas de Dados , Humanos , Estudos Retrospectivos , Nódulo da Glândula Tireoide/diagnóstico por imagem , Ultrassonografia , Estados Unidos
9.
New Phytol ; 223(3): 1530-1546, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31059122

RESUMO

How plants can distinguish pathogenic and symbiotic fungi remains largely unknown. Here, we characterized the role of MaLYK1, a lysin motif receptor kinase of banana. Live cell imaging techniques were used in localization studies. RNA interference (RNAi)-silenced transgenic banana plants were generated to analyze the biological role of MaLYK1. The MaLYK1 ectodomain, chitin beads, chitooligosaccharides (COs) and mycorrhizal lipochitooligosaccharides (Myc-LCOs) were used in pulldown assays. Ligand-induced MaLYK1 complex formation was tested in immunoprecipitation experiments. Chimeric receptors were expressed in Lotus japonicus to characterize the function of the MaLYK1 kinase domain. MaLYK1 was localized to the plasma membrane. MaLYK1 expression was induced by Foc4 (Fusarium oxysporum f. sp. cubense race 4) and diverse microbe-associated molecular patterns. MaLYK1-silenced banana lines showed reduced chitin-triggered defense responses, increased Foc4-induced disease symptoms and reduced mycorrhization. The MaLYK1 ectodomain was pulled down by chitin beads and LCOs or COs impaired this process. Ligand treatments induced MaLYK1 complex formation in planta. The kinase domain of MaLYK1 could functionally replace that of the chitin elicitor receptor kinase 1 (AtCERK1) in Arabidopsis thaliana and of a rhizobial LCO (Nod factor) receptor (LjNFR1) in L. japonicus. MaLYK1 represents a central molecular switch that controls defense- and symbiosis-related signaling.


Assuntos
Musa/metabolismo , Musa/microbiologia , Proteínas de Plantas/metabolismo , Transdução de Sinais , Simbiose , Arabidopsis/metabolismo , Quitina/análogos & derivados , Quitina/metabolismo , Quitosana , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Lotus/metabolismo , Musa/genética , Micorrizas/fisiologia , Oligossacarídeos , Moléculas com Motivos Associados a Patógenos/metabolismo , Proteínas de Plantas/química , Domínios Proteicos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
10.
Am J Physiol Cell Physiol ; 308(5): C349-58, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25500739

RESUMO

Nestin is highly expressed in poorly differentiated and newly formed proliferating endothelial cells (ECs); however, the role of this protein in angiogenesis remains unknown. Additionally, the cytoskeleton and associated cytoskeleton-binding proteins mediate the migration of vascular ECs. Therefore, the aim of the present study was to determine whether VEGF regulates the cytoskeleton, as well as other associated proteins, to promote the migration of vascular ECs. The coexpression of nestin and CD31 during angiogenesis in alkali-burned rat corneas was examined via immunohistochemical analysis. Western blot analyses revealed that the exposure of human umbilical vein endothelial cells (HUVECs) to hypoxia promoted nestin expression in vitro. Additionally, nestin silencing via siRNA significantly inhibited many of the process associated with VEGF-induced angiogenesis, including tube formation and the migration and proliferation of HUVECs. Moreover, FITC-phalloidin labeling revealed that F-actin filaments were successfully organized into microfilaments in VEGF-treated cells, suggesting a network rearrangement accomplished via F-actin that contrasted with the uniform and loose actin filament network observed in the siRNA-nestin cells. The results of the present study highlight the key role played by nestin in activated HUVECs during angiogenesis. The inhibition of the ERK pathway suppressed the nestin expression induced by VEGF in the HUVECs. Therefore, our study provides the first evidence that nestin-mediated cytoskeleton remodeling in ECs occurs via filopodia formation along the cell edge, facilitating both filopodia localization and cell polarization and ultimately promoting HUVEC migration via VEGF induction, which may be associated with ERK pathway activation.


Assuntos
Indutores da Angiogênese/farmacologia , Movimento Celular/fisiologia , Citoesqueleto/fisiologia , Células Endoteliais/fisiologia , Nestina/fisiologia , Fator A de Crescimento do Endotélio Vascular/farmacologia , Animais , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Citoesqueleto/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Feminino , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/fisiologia , Humanos , Pseudópodes/efeitos dos fármacos , Pseudópodes/fisiologia , Ratos , Ratos Sprague-Dawley
11.
J Cell Biochem ; 116(10): 2313-24, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25833759

RESUMO

Fetal growth restriction (FGR) increases the risk of perinatal death, partly due to defects in lung development. Leptin, a polypeptide hormone, is involved in fetal lung development. We previously demonstrated that treatment with exogenous leptin during gestation significantly promotes fetal lung maturity in the rat model of FGR. In this study, to delineate the molecular pathways through which leptin may enhance fetal lung development, we investigated the impact of leptin treatment on the survival of type II alveolar epithelial cells (AECs), essential leptin-responsive cells involved in lung development, in a rat model of FGR. The rat model of FGR was induced in pregnant Sprague-Dawley rats by partial uterine artery and vein ligation. In vivo and in vitro analyses of fetal lung tissues and freshly-isolated cultured AECs, respectively, showed that leptin protects type II AECs from hypoxia-induced apoptosis. Further molecular studies revealed the role of Akt activation in the leptin-mediated promotion of survival of type II AECs. The data also showed that the anti-apoptotic effects of leptin are dependent on phosphoinositol 3-kinase (PI3K) activation, and involve the down-regulation of caspases 3 and 9, upregulation of pro-survival proteins Bcl-2, and p-Bad, and inhibition of the release of cytochrome c from mitochondria. Taken together, our data suggested that leptin enhances the maturity of fetal lungs by mediating the regulation of caspase-3 and -9 during hypoxia-induced apoptosis of type II AECs and provide support for the potential of leptin as a therapeutic agent for promoting lung development in FGR.


Assuntos
Citocromos c/metabolismo , Desenvolvimento Fetal , Leptina/metabolismo , Pulmão/metabolismo , Proteína Oncogênica v-akt/genética , Animais , Apoptose/genética , Citocromos c/antagonistas & inibidores , Células Epiteliais/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Leptina/genética , Pulmão/crescimento & desenvolvimento , Mitocôndrias/metabolismo , Proteína Oncogênica v-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Gravidez , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Alvéolos Pulmonares/crescimento & desenvolvimento , Alvéolos Pulmonares/metabolismo , Ratos , Ratos Sprague-Dawley , Proteína de Morte Celular Associada a bcl/metabolismo
12.
Sensors (Basel) ; 15(1): 1496-517, 2015 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-25594592

RESUMO

Grain separation losses is a key parameter to weigh the performance of combine harvesters, and also a dominant factor for automatically adjusting their major working parameters. The traditional separation losses monitoring method mainly rely on manual efforts, which require a high labor intensity. With recent advancements in sensor technology, electronics and computational processing power, this paper presents an indirect method for monitoring grain separation losses in tangential-axial combine harvesters in real-time. Firstly, we developed a mathematical monitoring model based on detailed comparative data analysis of different feeding quantities. Then, we developed a grain impact piezoelectric sensor utilizing a YT-5 piezoelectric ceramic as the sensing element, and a signal process circuit designed according to differences in voltage amplitude and rise time of collision signals. To improve the sensor performance, theoretical analysis was performed from a structural vibration point of view, and the optimal sensor structural has been selected. Grain collide experiments have shown that the sensor performance was greatly improved. Finally, we installed the sensor on a tangential-longitudinal axial combine harvester, and grain separation losses monitoring experiments were carried out in North China, which results have shown that the monitoring method was feasible, and the biggest measurement relative error was 4.63% when harvesting rice.


Assuntos
Agricultura/instrumentação , Eletricidade , Sementes/crescimento & desenvolvimento , Modelos Teóricos , Processamento de Sinais Assistido por Computador , Análise de Ondaletas
13.
Artigo em Inglês | MEDLINE | ID: mdl-38659209

RESUMO

OBJECTIVE: This retrospective study involving a large dataset of unilateral multifocal papillary thyroid carcinoma (UM-PTC) sought to identify factors that predict central lymph node metastases (CLNM) in patients. METHODS: We identified a cohort of 158 patients who underwent cervical ultrasonography followed by UM-PTC diagnosis based on postoperative pathology. The relationship between CLNM and UM-PTC clinical ultrasound features was evaluated using univariate and multivariate analyses. Receiver operating characteristic (ROC) curve analysis was used to determine the ability of total tumor diameter (TTD) to predict CLNM. RESULTS: Among the 158 UM-PTC patients, the incidence of CLNM was 29.7% (47/158). Univariate and multivariate analyses revealed that a number of similarity of sonographic features (NSSF) ≥4 (odds ratio [OR] = 11.335, 95% confidence interval [CI]: 3.95-32.50, p = 0.000), microcalcifications (OR = 3.54, 95% CI: 1.30-9.70, p = 0.014), a TTD of ≥2 cm (OR = 4.48, 95% CI: 1.62-12.34, p = 0.004), number of nodules ≥3 (OR = 13.17, 95% CI: 3.24-53.52, p = 0.000), and Lateral cervical lymph node metastasis (LLNM) (OR = 5.57, 95% CI: 1.59-19.48, p = 0.007) were independently associated with CLNM in UM-PTC. ROC curve analysis revealed that the TTD cut-off of 1.795 cm had a sensitivity of 0.723 and a specificity of 0.676 for predicting CLNM. CONCLUSIONS: Patients with UM-PTC are at high risk of CLNM. NSSF ≥4, microcalcifications, TTD of ≥2 cm, LLNM, and a number of nodules ≥3 were independently associated with CLNM. Our data show that ultrasound may guide surgical decisions in the treatment of UM-PTC.

14.
Nat Commun ; 15(1): 935, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38296999

RESUMO

Switch defective/sucrose non-fermentable (SWI/SNF) chromatin remodeling complexes are multi-subunit machineries that establish and maintain chromatin accessibility and gene expression by regulating chromatin structure. However, how the remodeling activities of SWI/SNF complexes are regulated in eukaryotes remains elusive. B-cell lymphoma/leukemia protein 7 A/B/C (BCL7A/B/C) have been reported as subunits of SWI/SNF complexes for decades in animals and recently in plants; however, the role of BCL7 subunits in SWI/SNF function remains undefined. Here, we identify a unique role for plant BCL7A and BCL7B homologous subunits in potentiating the genome-wide chromatin remodeling activities of SWI/SNF complexes in plants. BCL7A/B require the catalytic ATPase BRAHMA (BRM) to assemble with the signature subunits of the BRM-Associated SWI/SNF complexes (BAS) and for genomic binding at a subset of target genes. Loss of BCL7A and BCL7B diminishes BAS-mediated genome-wide chromatin accessibility without changing the stability and genomic targeting of the BAS complex, highlighting the specialized role of BCL7A/B in regulating remodeling activity. We further show that BCL7A/B fine-tune the remodeling activity of BAS complexes to generate accessible chromatin at the juvenility resetting region (JRR) of the microRNAs MIR156A/C for plant juvenile identity maintenance. In summary, our work uncovers the function of previously elusive SWI/SNF subunits in multicellular eukaryotes and provides insights into the mechanisms whereby plants memorize the juvenile identity through SWI/SNF-mediated control of chromatin accessibility.


Assuntos
Cromatina , Fatores de Transcrição , Animais , Cromatina/genética , Fatores de Transcrição/metabolismo , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Montagem e Desmontagem da Cromatina , Expressão Gênica
15.
Micromachines (Basel) ; 15(4)2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38675353

RESUMO

The heterogeneity of circulating tumor cells has a significant impact on the diagnosis, treatment, and monitoring of cancer. Research on the subtypes of circulating tumor cells can bring better treatment outcomes for cancer patients. Here, we proposed a microfluidic chip for the magnetic capture of subtypes of circulating tumor cells from the whole blood and phenotypic profiling by stacking laminar flow vertically. Circulating tumor cells were sorted and captured by the three-dimensional regulation of both magnetic fields in the vertical direction and flow fields in the lateral direction. Using EpCAM-magnetic beads, we achieved sorting and sectional capture of target cells in whole blood and analyzed the surface expression levels of the captured cells, confirming the functionality of the microfluidic chip in sorting and capturing subtypes of circulating tumor cells. This microfluidic chip can also aid in the subsequent subtype analysis of other rare cells.

16.
Dev Cell ; 59(7): 924-939.e6, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38359831

RESUMO

Brassinosteroid (BR) signaling leads to the nuclear accumulation of the BRASSINAZOLE-RESISTANT 1 (BZR1) transcription factor, which plays dual roles in activating or repressing the expression of thousands of genes. BZR1 represses gene expression by recruiting histone deacetylases, but how it activates transcription of BR-induced genes remains unclear. Here, we show that BR reshapes the genome-wide chromatin accessibility landscape, increasing the accessibility of BR-induced genes and reducing the accessibility of BR-repressed genes in Arabidopsis. BZR1 physically interacts with the BRAHMA-associated SWI/SNF (BAS)-chromatin-remodeling complex on the genome and selectively recruits the BAS complex to BR-activated genes. Depletion of BAS abrogates the capacities of BZR1 to increase chromatin accessibility, activate gene expression, and promote cell elongation without affecting BZR1's ability to reduce chromatin accessibility and expression of BR-repressed genes. Together, these data identify that BZR1 recruits the BAS complex to open chromatin and to mediate BR-induced transcriptional activation of growth-promoting genes.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Cromatina/genética , Cromatina/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Ativação Transcricional , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Regulação da Expressão Gênica de Plantas
17.
Quant Imaging Med Surg ; 13(6): 3776-3788, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37284109

RESUMO

Background: This study sought to investigate the applicability of different ultrasound (US) thyroid risk stratification systems in diagnosing medullary thyroid carcinoma (MTC) and determining the need for biopsy. Methods: In total, 34 MTC nodules, 54 papillary thyroid carcinoma (PTC) nodules, and 62 benign thyroid nodules were examined in this study. All the diagnoses were histopathologically confirmed postoperatively. All the thyroid nodule sonographic features were recorded and categorized by 2 independent reviewers according to the Thyroid Imaging Reporting and Data System (TIRADS) of the American College of Radiology (ACR), the American Thyroid Association (ATA) guidelines, the European Thyroid Association (EU) TIRADS, the Kwak-TIRADS, and the Chinese TIRADS (C-TIRADS). The sonographic differences and risk stratifications of the MTCs, PTCs, and benign thyroid nodules were analyzed. The diagnostic performance and recommended biopsy rates for each classification system were evaluated. Results: The risk stratifications of MTCs were all higher than the benign thyroid nodules (P<0.01) and lower than PTCs (P<0.01) with each classification system. Hypoechogenicity and malignant marginal features were independent risk factors for identifying malignant thyroid nodules, and the area under the receiver operating characteristic curve (AUC) for identifying MTCs was lower than that for identifying PTCs (0.873 vs. 0.954, respectively). The AUCs, sensitivity, specificity, positive predictive values, negative predictive values, and accuracy values of the 5 systems for MTC were all lower than those for PTC. The best cut-off values for diagnosing MTC were TIRADS (TR) 4 in the ACR-TIRADS, intermediate suspicion in the ATA guidelines, TR 4 in EU-TIRADS, and TR 4b in both the Kwak-TIRADS and the C-TIRADS. The Kwak-TIRADS had the highest recommended biopsy rate for MTCs (97.1%), followed by the ATA guidelines, the EU-TIRADS (88.2%), the C-TIRADS (85.3%), and the ACR-TIRADS (79.4%). Conclusions: The US-based thyroid malignancy risk stratification systems analyzed in this study were able to satisfactorily identify MTC and recommend biopsy, but the diagnostic performance of these systems for MTC was not as good as that for PTC.

18.
Orphanet J Rare Dis ; 18(1): 30, 2023 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-36800969

RESUMO

BACKGROUND: Intrathecal injection of medications can be challenging in spinal muscular atrophy (SMA) patients with severe scoliosis or after spine surgery. Here we report our experience with real-time ultrasound (US)-guided intrathecal administration of nusinersen in patients with SMA. METHODS: Seven patients (six children and one adult) with either spinal fusion or severe scoliosis were enrolled. We performed intrathecal injections of nusinersen under US guidance. The efficacy and safety of US-guided injection were explored. RESULTS: Five patients had undergone spinal fusion, while the other two presented severe scoliosis. Success was achieved in 19/20 lumbar punctures (95%), 15 of which were performed through the near-spinous process approach. The intervertebral space with a designated channel was selected for the five postoperative patients, while the interspaces with the smallest rotation angle were chosen for the other two patients with severe scoliosis. In 89.5% (17/19) of the punctures, the number of insertions was no more than two. No major adverse events were observed. CONCLUSION: Given its safety and efficacy, real-time US guidance is recommended for SMA patients with spine surgery or severe scoliosis, and the near-spinous process view can be used as a interlaminar puncture approach for US guidance.


Assuntos
Atrofia Muscular Espinal , Escoliose , Fusão Vertebral , Criança , Adulto , Humanos , Escoliose/tratamento farmacológico , Escoliose/cirurgia , Atrofia Muscular Espinal/tratamento farmacológico , Atrofia Muscular Espinal/cirurgia , Ultrassonografia de Intervenção
19.
ACS Nano ; 17(3): 2101-2113, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36479877

RESUMO

Intracellular delivery and genetic modification have brought a significant revolutionary to tumor immunotherapy, yet existing methods are still limited by low delivery efficiency, poor throughput, excessive cell damage, or unsuitability for suspension immune cells, specifically the natural killer cell, which is highly resistant to transfection. Here, we proposed a vibration-assisted nanoneedle/microfluidic composite system that uses large-area nanoneedles to rapidly puncture and detach the fast-moving suspension cells in the microchannel under vibration to achieve continuous high-throughput intracellular delivery. The nanoneedle arrays fabricated based on the large-area self-assembly technique and microchannels can maximize the delivery efficiency. Cas9 ribonucleoprotein complexes (Cas9/RNPs) can be delivered directly into cells due to the sufficient cellular membrane nanoperforation size; for difficult-to-transfect immune cells, the delivery efficiency can be up to 98%, while the cell viability remains at about 80%. Moreover, the throughput is demonstrated to maintain a mL/min level, which is significantly higher than that of conventional delivery techniques. Further, we prepared CD96 knockout NK-92 cells via this platform, and the gene-edited NK-92 cells possessed higher immunity by reversing exhaustion. The high-throughput, high-efficiency, and low-damage performance of our intracellular delivery strategy has great potential for cellular immunotherapy in clinical applications.


Assuntos
Edição de Genes , Microfluídica , Sobrevivência Celular , Edição de Genes/métodos , Transfecção , Vibração , Imunoterapia/métodos , Humanos , Antígenos CD/genética , Antígenos CD/uso terapêutico , Ribonucleoproteínas/genética , Ribonucleoproteínas/uso terapêutico , Terapia Baseada em Transplante de Células e Tecidos/métodos
20.
Front Oncol ; 12: 929500, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36106124

RESUMO

Background: Although echogenic foci may raise malignancy rates in thyroid nodules, the association between peripheral calcification or macrocalcification and thyroid carcinoma is controversial. We evaluated the malignancy probability of various echogenic foci and explored whether the method of determining a thyroid nodule's point score in the echogenic focus category of the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) is reasonable. Methods: We retrospectively evaluated 819 patients with 852 nodules. The patterns of echogenic foci on ultrasonography were classified into the following four categories: punctate echogenic foci, macrocalcification, peripheral calcification, and multiple different types of echogenic foci. The core needle biopsy results were divided into two groups: benign and malignant or suspicious for malignancy. Results: Among the 852 nodules, 471 (55.3%) had echogenic foci on ultrasonography. Of these nodules, there was no significant statistical difference in the malignant or suspicious for malignancy rate between nodules with peripheral calcification and those with macrocalcification [40.0% (8/20) vs. 30.6% (11/36), respectively; p = 0.474]. The incidence of malignancy or suspicious for malignancy for nodules with peripheral calcification, macrocalcification, or multiple different types of echogenic foci was significantly lower than the incidence for punctate echogenic foci alone, with odds ratios of 0.265 [95% confidence interval (CI): 0.105-0.667; p = 0.005], 0.175 (95% CI: 0.083-0.368; p = 0.000), and 0.256 (95% CI: 0.136-0.482; p = 0.000), respectively. Conclusion: We found no significant statistical difference in the risk of malignancy or suspicious for malignancy rate between peripheral calcification and macrocalcification in thyroid nodules. We observed that nodules with multiple different types of echogenic foci were not associated with higher malignant or suspicious for malignancy rates compared with nodules with punctate echogenic foci alone.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA