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1.
Opt Express ; 32(5): 7197-7206, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38439407

RESUMEN

In this work, we demonstrate photonic fabrication by integrating waveguide resonators and groove structures using cost-effective i-line stepper lithography on a 6-inch full wafer. Low-loss silicon nitride (SiN) waveguide can be realized with the quality (Q) factor of waveguide resonators up to 105. In addition, groove structures are also integrated by the full-wafer process, providing long-term stability of coupling and package solutions. The uniformity of different die locations is verified within the full wafer, showing the good quality of the fabricated photonic devices. This process integration of photonic devices provides the potential for mass-productive, high-yield, and high-uniformity manufacturing.

2.
Surg Endosc ; 37(9): 6834-6843, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37308764

RESUMEN

BACKGROUND: The major treatment for perforated peptic ulcers (PPU) is surgery. It remains unclear which patient may not get benefit from surgery due to comorbidity. This study aimed to generate a scoring system by predicting mortality for patients with PPU who received non-operative management (NOM) and surgical treatment. METHOD: We extracted the admission data of adult (≥ 18 years) patients with PPU disease from the NHIRD database. We randomly divided patients into 80% model derivation and 20% validation cohorts. Multivariate analysis with a logistic regression model was applied to generate the scoring system, PPUMS. We then apply the scoring system to the validation group. RESULT: The PPUMS score ranged from 0 to 8 points, composite with age (< 45: 0 points, 45-65: 1 point, 65-80: 2 points, > 80: 3 points), and five comorbidities (congestive heart failure, severe liver disease, renal disease, history of malignancy, and obesity: 1 point each). The areas under ROC curve were 0.785 and 0.787 in the derivation and validation groups. The in-hospital mortality rates in the derivation group were 0.6% (0 points), 3.4% (1 point), 9.0% (2 points), 19.0% (3 points), 30.2% (4 points), and 45.9% when PPUMS > 4 point. Patients with PPUMS > 4 had a similar in-hospital mortality risk between the surgery group [laparotomy: odds ratio (OR) = 0.729, p = 0.320, laparoscopy: OR = 0.772, p = 0.697] and the non-surgery group. We identified similar results in the validation group. CONCLUSION: PPUMS scoring system effectively predicts in-hospital mortality for perforated peptic ulcer patients. It factors in age and specific comorbidities is highly predictive and well-calibrated with a reliable AUC of 0.785-0.787. Surgery, no matter laparotomy or laparoscope, significantly reduced mortality for scores < = 4. However, patients with a score > 4 did not show this difference, calling for tailored approaches to treatment based on risk assessment. Further prospective validation is suggested.


Asunto(s)
Laparoscopía , Úlcera Péptica Perforada , Adulto , Humanos , Resultado del Tratamiento , Mortalidad Hospitalaria , Medición de Riesgo , Laparoscopía/métodos , Úlcera Péptica Perforada/etiología , Estudios Retrospectivos
3.
Anticancer Res ; 43(5): 1933-1941, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37097665

RESUMEN

BACKGROUND/AIM: Colorectal cancer (CRC) is one of the most common malignancies and cause of cancer-related deaths worldwide. The combination of chemotherapeutics working with different mechanisms enhances the therapeutic effects and delays the development of resistance. This study investigated the anticancer effect of the combination of ribociclib (LEE011) and irinotecan (SN38) on CRC cells. MATERIALS AND METHODS: HT-29 and SW480 cells were treated with LEE011, SN38, or the combination of LEE011 and SN38. Cell viability and cell cycle distribution were analyzed. The expression of cell cycle- and apoptosis-related proteins was determined using western blot. RESULTS: The combination of LEE011 and SN38 elicited a synergistic antiproliferative effect on HT-29 (PIK3CAP449T mutation) cells, and an antagonistic antiproliferative effect on SW480 (KRASG12V mutation) cells. LEE011 inhibited retinoblastoma protein (Rb) phosphorylation and led to G1 arrest in HT-29 and SW480 cells. SN38 treatment caused a significant increase in the phosphorylation levels of Rb, cyclin B1, and CDC2 in SW480 cells and induced S phase arrest. Furthermore, SN38 treatment increased the phosphorylation levels of p53 and activated caspase-3 and caspase-8 in HT-29 and SW480 cells. LEE011-induced G1 arrest contributed to its synergistic antiproliferative effect with SN38 in HT-29 cells through the down-regulation of the phosphorylation of Rb. In addition, it elicited an antagonistic effect with SN38 in SW480 cells by changing the phosphorylation levels of Rb and activating caspase-8. CONCLUSION: The effects of the combination of LEE011 and conventional chemotherapy drugs on CRC depend on the chemotherapy drug and the specific gene mutation harbored by tumor cells.


Asunto(s)
Neoplasias Colorrectales , Humanos , Irinotecán/farmacología , Caspasa 8 , Proliferación Celular , Línea Celular Tumoral , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Camptotecina/farmacología , Apoptosis
4.
BMC Surg ; 23(1): 90, 2023 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-37060019

RESUMEN

BACKGROUND: There is no standard reconstruction method following proximal gastrectomy, of which gastroesophageal reflux and anastomotic complications are of great concern. Though several techniques have been devised to overcome these postoperative complications, such as double tract reconstruction, double-flap technique and side overlap fundoplication by Yamashita, none of them is considered a perfect solution. Herein, we designed a novel method of esophagogastrostomy after laparoscopic proximal gastrectomy (LPG), named right-sided overlap and single-flap valvuloplasty (ROSF). METHODS: Between March 2021 and December 2021, 20 consecutive patients underwent LPG-ROSF at Department of Gastrointestinal Surgery, Second Affiliated Hospital of Soochow University. Surgical outcomes and postoperative complications were recorded. All patients were followed-up until December 2022. Endoscopy and assessment of gastrointestinal symptoms were performed 1 year after surgery. Nutrition-related parameters including total body weight, hemoglobin, lymphocyte count, serum total protein, serum albumin and serum prealbumin were evaluated 1 year after surgery and compared with those before surgery. RESULTS: The mean surgery time and anastomosis time was 285.3 ± 71.3 and 61.3 ± 11.2 min respectively. None of the patients had gastrointestinal early postoperative complications. Symptomatic reflux was observed in one patient (5%) while reflux esophagitis (Los Angeles Grade A) was observed in another patient (5%). Four patients (20%) had mild dysphagia (Visick score = II) but none of them had anastomotic stenosis. There were no significant changes in nutritional status postoperatively. CONCLUSIONS: ROSF can be safely performed after LPG and has satisfactory outcomes in preventing reflux and stenosis, and maintaining nutritional status. This technique requires further validation.


Asunto(s)
Reflujo Gastroesofágico , Laparoscopía , Neoplasias Gástricas , Humanos , Constricción Patológica/cirugía , Laparoscopía/métodos , Neoplasias Gástricas/cirugía , Gastrectomía/métodos , Complicaciones Posoperatorias/etiología , Reflujo Gastroesofágico/cirugía , Reflujo Gastroesofágico/complicaciones , Estudios Retrospectivos , Resultado del Tratamiento
5.
Endocrinology ; 164(4)2023 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-36750942

RESUMEN

2,4-Di-tert-butylphenol (2,4-DTBP) is an important commercial antioxidant and a toxic natural secondary metabolite that has been detected in humans. However, there is scant information regarding its toxicological effects. We asked whether 2,4-DTBP is a potential obesogen. Using a human mesenchymal stem cell adipogenesis assay, we found that exposure to 2,4-DTBP led to increased lipid accumulation and expression of adipogenic marker genes. Antagonist assays revealed that 2,4-DTBP increased lipid accumulation by activating the peroxisome proliferator-activated receptor (PPAR) γ-retinoid X receptor (RXR) heterodimer. 2,4-DTBP likely activated the PPARγ/RXRα heterodimer by activating RXRα but not directly binding to PPARγ. We confirmed that 2,4-DTBP directly bound to RXRα by solving the crystal structure of this complex, then predicted and demonstrated that related compounds could also activate RXRα. Our study demonstrated that 2,4-DTBP and related chemicals could act as obesogens and endocrine disruptors via RXRs. These data showed that 2,4-DTBP belongs to a family of compounds whose endocrine-disrupting and obesogenic effects can be strongly modulated by their chemical composition. Structure-activity studies such as the present one could help guide the rational development of safer antioxidants that do not interact with important nuclear receptors having broad effects on human development and physiology.


Asunto(s)
Adipogénesis , Células Madre Mesenquimatosas , Humanos , Receptores X Retinoide , PPAR gamma/metabolismo , Lípidos
6.
Sensors (Basel) ; 21(24)2021 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-34960388

RESUMEN

This paper presents a wearable device, fitted on the waist of a participant that recognizes six activities of daily living (walking, walking upstairs, walking downstairs, sitting, standing, and laying) through a deep-learning algorithm, human activity recognition (HAR). The wearable device comprises a single-board computer (SBC) and six-axis sensors. The deep-learning algorithm employs three parallel convolutional neural networks for local feature extraction and for subsequent concatenation to establish feature fusion models of varying kernel size. By using kernels of different sizes, relevant local features of varying lengths were identified, thereby increasing the accuracy of human activity recognition. Regarding experimental data, the database of University of California, Irvine (UCI) and self-recorded data were used separately. The self-recorded data were obtained by having 21 participants wear the device on their waist and perform six common activities in the laboratory. These data were used to verify the proposed deep-learning algorithm on the performance of the wearable device. The accuracy of these six activities in the UCI dataset and in the self-recorded data were 97.49% and 96.27%, respectively. The accuracies in tenfold cross-validation were 99.56% and 97.46%, respectively. The experimental results have successfully verified the proposed convolutional neural network (CNN) architecture, which can be used in rehabilitation assessment for people unable to exercise vigorously.


Asunto(s)
Aprendizaje Profundo , Dispositivos Electrónicos Vestibles , Actividades Cotidianas , Algoritmos , Actividades Humanas , Humanos
7.
Sci Adv ; 7(4)2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33523934

RESUMEN

Polycomb group (PcG) proteins form multiprotein complexes that affect stem cell identity and fate decisions by still largely unexplored mechanisms. Here, by performing a CRISPR-based loss-of-function screen in embryonic stem cells (ESCs), we identify PcG gene Mga involved in the repression of endodermal transcription factor Gata6 We report that deletion of Mga results in peri-implantation embryonic lethality in mice. We further demonstrate that Mga-null ESCs exhibit impaired self-renewal and spontaneous differentiation to primitive endoderm (PE). Our data support a model in which Mga might serve as a scaffold for PRC1.6 assembly and guide this multimeric complex to specific genomic targets including genes that encode endodermal factors Gata4, Gata6, and Sox17. Our findings uncover an unexpected function of Mga in ESCs, where it functions as a gatekeeper to prevent ESCs from entering into the PE lineage by directly repressing expression of a set of endoderm differentiation master genes.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Células Madre Embrionarias , Endodermo , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Diferenciación Celular/genética , Células Madre Embrionarias/metabolismo , Factor de Transcripción GATA6/genética , Factor de Transcripción GATA6/metabolismo , Regulación del Desarrollo de la Expresión Génica , Ratones
8.
Stem Cell Reports ; 16(3): 566-581, 2021 03 09.
Artículo en Inglés | MEDLINE | ID: mdl-33606987

RESUMEN

Polycomb group (PcG) proteins exist in distinct multi-protein complexes and play a central role in silencing developmental genes, yet the underlying mechanisms remain elusive. Here, we show that deficiency of retinoblastoma binding protein 4 (RBBP4), a component of the Polycomb repressive complex 2 (PRC2), in embryonic stem cells (ESCs) leads to spontaneous differentiation into mesendodermal lineages. We further show that Rbbp4 and core PRC2 share an important number of common genomic targets, encoding regulators involved in early germ layer specification. Moreover, we find that Rbbp4 is absolutely essential for genomic targeting of PRC2 to a subset of developmental genes. Interestingly, we demonstrate that Rbbp4 is necessary for sustaining the expression of Oct4 and Sox2 and that the forced co-expression of Oct4 and Sox2 fully rescues the pluripotency of Rbbp4-null ESCs. Therefore, our study indicates that Rbbp4 links maintenance of the pluripotency regulatory network with repression of mesendoderm lineages.


Asunto(s)
Diferenciación Celular , Células Madre Embrionarias/fisiología , Regulación del Desarrollo de la Expresión Génica , Complejo Represivo Polycomb 2/fisiología , Proteína 4 de Unión a Retinoblastoma/fisiología , Animales , Línea Celular , Autorrenovación de las Células , Secuenciación de Inmunoprecipitación de Cromatina , Técnicas de Inactivación de Genes , Células HEK293 , Histonas/metabolismo , Humanos , Metilación , Ratones , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Factores de Transcripción SOXB1/metabolismo
9.
Langenbecks Arch Surg ; 406(2): 497-502, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33420833

RESUMEN

PURPOSE: Esophagojejunostomy is a challenging step in laparoscopic gastrectomy. Although the overlap method is a safe and feasible approach for esophagojejunostomy, it has several technical limitations. We developed novel modifications for the overlap method to overcome these disadvantages. METHODS: Forty-eight consecutive gastric cancer patients underwent totally laparoscopic total gastrectomy or laparoscopic proximal gastrectomy with double-tract reconstruction at our institution from January 2019 to April 2020 using the overlap method with the following modifications. The esophagus was initially rotated by 90° counterclockwise, followed by transection of two-thirds of the esophageal diameter. The unstapled esophagus was then transected with a harmonic ultrasonic scalpel to enable esophagostomy at the posterior side of the esophagus. A side-to-side esophagojejunostomy was then formed at the posterior side of the esophagus using an endoscopic linear stapler through the right lower trocar. The common entry hole was closed via hand sewing method using V-Loc suture. This procedure was termed "esophagus two-step-cut overlap method." RESULTS: Only one patient suffered from esophagojejunal anastomotic leakage but subsequently recovered after conservative treatment. Patients did not experience anastomotic bleeding or stricture. CONCLUSION: Our modified overlap method provides satisfactory surgical outcomes and overcomes several technical limitations, such as entering the false lumen of the esophagus, unnecessary pollution caused by nasogastric tube, and unintended left crus stapling during anastomosis.


Asunto(s)
Laparoscopía , Neoplasias Gástricas , Anastomosis Quirúrgica , Esófago/cirugía , Gastrectomía/efectos adversos , Humanos , Yeyuno/cirugía , Neoplasias Gástricas/cirugía , Grapado Quirúrgico/efectos adversos
10.
Pharmaceuticals (Basel) ; 13(3)2020 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-32197544

RESUMEN

This network meta-analysis aimed to integrate the available direct and indirect evidence on regenerative injections-including 5% dextrose (D5W) and platelet-rich plasma (PRP)-for the treatment of carpal tunnel syndrome (CTS). Literature reports comparing D5W and PRP injections with non-surgical managements of CTS were systematically reviewed. The main outcome was the standardized mean difference (SMD) of the symptom severity and functional status scales of the Boston Carpal Tunnel Syndrome Questionnaire at three months after injections. Ranking probabilities of the SMD of each treatment were acquired by using simulation. Ten studies with 497 patients and comparing five treatments (D5W, PRP, splinting, corticosteroid, and normal saline) were included. The results of the simulation of rank probabilities showed that D5W injection was likely to be the best treatment, followed by PRP injection, in terms of clinical effectiveness in providing symptom relief. With respect to functional improvement, splinting ranked higher than PRP and D5W injections. Lastly, corticosteroid and saline injections were consistently ranked fourth and fifth in terms of therapeutic effects on symptom severity and functional status. D5W and PRP injections are more effective than splinting and corticosteroid or saline injection for relieving the symptoms of CTS. Compared with splinting, D5W and PRP injections do not provide better functional recovery. More studies investigating the long-term effectiveness of regenerative injections in CTS are needed in the future.

11.
Cell Physiol Biochem ; 49(3): 947-960, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30184537

RESUMEN

BACKGROUND/AIMS: The hydroxylation of fatty acids at the C-2 position is the first step of fatty acid α-oxidation and generates sphingolipids containing 2-hydroxy fatty acyl moieties. Fatty acid 2-hydroxylation is catalyzed by Fatty acid 2-hydroxylase (FA2H) enzyme. However, the precise roles of FA2H and fatty acid 2-hydroxylation in whole cell homeostasis still remain unclear. METHODS: Here we utilize Caenorhabditis elegans as the model and systemically investigate the physiological functions of FATH-1/C25A1.5, the highly conserved worm homolog for mammalian FA2H enzyme. Immunostaining, dye-staining and translational fusion reporters were used to visualize FATH-1 protein and a variety of subcellular structures. The "click chemistry" method was employed to label 2-OH fatty acid in vivo. Global and tissue-specific RNAi knockdown experiments were performed to inactivate FATH-1 function. Lipid analysis of the fath-1 deficient mutants was achieved by mass spectrometry. RESULTS: C. elegans FATH-1 is expressed at most developmental stages and in most tissues. Loss of fath-1 expression results in severe growth retardation and shortened lifespan. FATH-1 function is crucially required in the intestine but not the epidermis with stereospecificity. The "click chemistry" labeling technique showed that the FATH-1 metabolites are mainly enriched in membrane structures preferable to the apical side of the intestinal cells. At the subcellular level, we found that loss of fath-1 expression inhibits lipid droplets formation, as well as selectively disrupts peroxisomes and apical endosomes. Lipid analysis of the fath-1 deficient animals revealed a significant reduction in the content of heptadecenoic acid, while other major FAs remain unaffected. Feeding of exogenous heptadecenoic acid (C17: 1), but not oleic acid (C18: 1), rescues the global and subcellular defects of fath-1 knockdown worms. CONCLUSION: Our study revealed that FATH-1 and its catalytic products are highly specific in the context of chirality, C-chain length, spatial distribution, as well as the types of cellular organelles they affect. Such an unexpected degree of specificity for the synthesis and functions of hydroxylated FAs helps to regulate protein transport and fat metabolism, therefore maintaining the cellular homeostasis of the intestinal cells. These findings may help our understanding of FA2H functions across species, and offer potential therapeutical targets for treating FA2H-related diseases.


Asunto(s)
Proteínas de Caenorhabditis elegans/metabolismo , Ácidos Grasos Monoinsaturados/metabolismo , Mucosa Intestinal/metabolismo , Oxigenasas de Función Mixta/metabolismo , Animales , Caenorhabditis elegans/crecimiento & desarrollo , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/antagonistas & inhibidores , Proteínas de Caenorhabditis elegans/genética , Endosomas/metabolismo , Ácidos Grasos/análisis , Ácidos Grasos/metabolismo , Larva/metabolismo , Longevidad , Espectrometría de Masas , Oxigenasas de Función Mixta/antagonistas & inhibidores , Oxigenasas de Función Mixta/genética , Peroxisomas/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Estereoisomerismo
12.
J Biol Chem ; 293(33): 12793-12804, 2018 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-29959227

RESUMEN

The polycomb group (PcG) proteins are key epigenetic regulators in stem cell maintenance. PcG proteins have been thought to act through one of two polycomb repressive complexes (PRCs), but more recent biochemical analyses have challenged this model in the identification of noncanonical PRC1 (nc-PRC1) complexes characterized by the presence of Rybp or Yaf2 in place of the canonical Chromobox proteins. However, the biological significance of these nc-PRC1s and the potential mechanisms by which they mediate gene repression are largely unknown. Here, we explore the functional consequences of Yaf2 disruption on stem cell regulation. We show that deletion of Yaf2 results in compromised proliferation and abnormal differentiation of mouse embryonic stem cells (mESCs). Genome-wide profiling indicates Yaf2 functions primarily as a transcriptional repressor, particularly impacting genes associated with ectoderm cell fate in a manner distinct from Rybp. We confirm that Yaf2 assembles into a noncanonical PRC complex, with deletion analysis identifying the region encompassing amino acid residues 102-150 as required for this assembly. Furthermore, we identified serine 166 as a Yaf2 phosphorylation site, and we demonstrate that mutation of this site to alanine (S166A) compromises Ring1B-mediated H2A monoubiquitination and in turn its ability to repress target gene expression. We therefore propose that Yaf2 and its phosphorylation status serve as dual regulators to maintain the pluripotent state in mESCs.


Asunto(s)
Diferenciación Celular , Histonas/metabolismo , Células Madre Embrionarias de Ratones/citología , Proteínas Musculares/fisiología , Complejo Represivo Polycomb 1/metabolismo , Proteínas Represoras/fisiología , Animales , Células Cultivadas , Cromatina/genética , Perfilación de la Expresión Génica , Ratones , Ratones Noqueados , Células Madre Embrionarias de Ratones/metabolismo , Fosforilación , Complejo Represivo Polycomb 1/genética
13.
Cell Rep ; 22(11): 3032-3043, 2018 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-29539429

RESUMEN

Though genetic data suggest that Polycomb group proteins (PcGs) are central chromatin modifiers and repressors that have been implicated in control of embryonic stem cell (ESC) pluripotency, the precise mechanism of PcG complex recruitment remains elusive, especially in mammals. We now report that the first and second MBT repeats of L3mbtl2 are important structural and functional features that are necessary and sufficient for L3mbtl2-mediated recruitment of PRC1.6 complex to target promoters. Interestingly, this region of L3mbtl2 harbors the evolutionarily conserved Pho-binding pocket also present in Drosophila Sfmbt, and mutation of the critical residues within this pocket completely abolishes its interaction with target promoters. Additionally, decreased PRC1.6 chromatin occupancy was observed following loss of individual components (L3mbtl2, Pcgf6, and Max) of the complex. Our findings suggest that the recruitment of noncanonical PRC1.6 complex in ESCs might be the result of L3mbtl2's interaction with multiple components of the complex.


Asunto(s)
Células Madre Embrionarias/metabolismo , Variación Genética/genética , Diferenciación Celular , Humanos
14.
J Biol Chem ; 292(52): 21527-21537, 2017 12 29.
Artículo en Inglés | MEDLINE | ID: mdl-29054931

RESUMEN

Polycomb group (PcG) proteins are epigenetic transcriptional repressors that orchestrate numerous developmental processes and have been implicated in the maintenance of embryonic stem (ES) cell state. More recent evidence suggests that a subset of PcG proteins engages in transcriptional activation in some cellular contexts, but how this property is exerted remains largely unknown. Here, we generated ES cells with single or combined disruption of polycomb group RING finger protein 3 (Pcgf3) and Pcgf5 with the CRISPR-Cas9 technique. We report that although these mutant cells maintained their self-renewal and colony-forming capacity, they displayed severe defects in mesoderm differentiation in vitro and in vivo Using RNA-seq to analyze transcriptional profiles of ES cells with single or combined Pcgf3/5 deficiencies, we found that in contrast to the canonical role of the related polycomb repressive complex 1 (PRC1) in gene repression, Pcgf3/5 mainly function as transcriptional activators driving expression of many genes involved in mesoderm differentiation. Proteomic approaches and promoter occupancy analyses helped to establish an extended Pcgf3/5 interactome and identified several novel Pcgf3/5 interactors. These included testis-expressed 10 (Tex10), which may directly contribute to transcriptional activation via the transcriptional co-activator p300. Furthermore, Pcgf3/5 deletion in ES cells substantially reduced the occupancy of Tex10 and p300 at target genes. Finally, we demonstrated that Pcgf3/5 are essential for regulating global levels of the histone modifier H2AK119ub1 in ES cells. Our findings establish Pcgf3/5 as transcriptional activators that interact with Tex10 and p300 in ES cells and point to redundant activity of Pcgf3/5 in pluripotency maintenance.


Asunto(s)
Proteínas del Grupo Polycomb/metabolismo , Animales , Diferenciación Celular/genética , Línea Celular , Histonas/metabolismo , Ratones , Células Madre Embrionarias de Ratones/citología , Proteínas Nucleares/metabolismo , Complejo Represivo Polycomb 1/metabolismo , Proteínas del Grupo Polycomb/genética , Proteínas del Grupo Polycomb/fisiología , Regiones Promotoras Genéticas/genética , Activación Transcripcional/fisiología
15.
Sci Rep ; 7: 46276, 2017 04 10.
Artículo en Inglés | MEDLINE | ID: mdl-28393894

RESUMEN

The Polycomb repressive complex 1 (PRC1) is essential for fate decisions of embryonic stem (ES) cells. Emerging evidence suggests that six major variants of PRC1 complex, defined by the mutually exclusive presence of Pcgf subunit, regulate distinct biological processes, yet very little is known about the mechanism by which each version of PRC1 instructs and maintains cell fate. Here, we disrupted the Pcgf1, also known as Nspc1 and one of six Pcgf paralogs, in mouse ES cells by the CRISPR/Cas9 technology. We showed that although these mutant cells were viable and retained normal self-renewal, they displayed severe defects in differentiation in vitro. To gain a better understanding of the role of Pcgf1 in transcriptional control of differentiation, we analysed mRNA profiles from Pcgf1 deficient cells using RNA-seq. Interestingly, we found that Pcgf1 positively regulated expression of essential transcription factors involved in ectoderm and mesoderm differentiation, revealing an unexpected function of Pcgf1 in gene activation during ES cell lineage specification. Chromatin immunoprecipitation experiments demonstrated that Pcgf1 deletion caused a decrease in Ring1B and its associated H2AK119ub1 mark binding to target genes. Altogether, our results suggested an unexpected function of Pcgf1 in gene activation during ES cell maintenance.


Asunto(s)
Diferenciación Celular/genética , Células Madre Embrionarias/citología , Células Madre Embrionarias/metabolismo , Complejo Represivo Polycomb 1/deficiencia , Animales , Biomarcadores , Sistemas CRISPR-Cas , Línea Celular , Autorrenovación de las Células/genética , Técnicas de Inactivación de Genes , Marcación de Gen , Ratones , Modelos Biológicos , Células Madre Embrionarias de Ratones/citología , Células Madre Embrionarias de Ratones/metabolismo , Unión Proteica , Transactivadores/metabolismo
16.
ACS Nano ; 11(5): 4439-4444, 2017 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-28287703

RESUMEN

Reliably obtaining nanostructures of complex oxides over large area with nanoscale resolution and well-controlled shape, spacing, and pattern symmetry remains a major challenge. In this article, millions of nanowells have been routinely generated by beam pen lithography. Each attoliter volume nanowell functions as a "nanoreactor", inside which oxide nanostructures are synthesized from their sol-gel precursors. Importantly, these nanometer scale entities are in single crystalline or textured forms and epitaxial to the underlying substrates, which promises functionalities including ferroelectricity, ferromagnetism, and multiferroicity. This method provides a general solution which allows one to rapidly screen structural parameters of oxide nanostructures comprising of three or more elements for prominent properties.

17.
J Biol Chem ; 292(7): 2773-2784, 2017 02 17.
Artículo en Inglés | MEDLINE | ID: mdl-28049731

RESUMEN

The Polycomb group (PcG) proteins have an important role in controlling the expression of key genes implicated in embryonic development, differentiation, and decision of cell fates. Emerging evidence suggests that Polycomb repressive complexes 1 (PRC1) is defined by the six Polycomb group RING finger protein (Pcgf) paralogs, and Pcgf proteins can assemble into noncanonical PRC1 complexes. However, little is known about the precise mechanisms of differently composed noncanonical PRC1 in the maintenance of the pluripotent cell state. Here we disrupt the Pcgf genes in mouse embryonic stem cells by CRISPR-Cas9 and find Pcgf6 null embryonic stem cells display severe defects in self-renewal and differentiation. Furthermore, Pcgf6 regulates genes mostly involved in differentiation and spermatogenesis by assembling a noncanonical PRC1 complex PRC1.6. Notably, Pcgf6 deletion causes a dramatic decrease in PRC1.6 binding to target genes and no loss of H2AK119ub1. Thus, Pcgf6 is essential for recruitment of PRC1.6 to chromatin. Our results reveal a previously uncharacterized, H2AK119ub1-independent chromatin assembly associated with PRC1.6 complex.


Asunto(s)
Células Madre Embrionarias/citología , Complejo Represivo Polycomb 1/fisiología , Proteínas del Grupo Polycomb/metabolismo , Animales , Diferenciación Celular , Células Cultivadas , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Ratones , Complejo Represivo Polycomb 1/genética
18.
J Am Chem Soc ; 137(5): 1742-5, 2015 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-25608577

RESUMEN

Lithiation-exfoliation produces single to few-layered MoS2 and WS2 sheets dispersible in water. However, the process transforms them from the pristine semiconducting 2H phase to a distorted metallic phase. Recovery of the semiconducting properties typically involves heating of the chemically exfoliated sheets at elevated temperatures. Therefore, it has been largely limited to sheets deposited on solid substrates. Here, we report the dispersion of chemically exfoliated MoS2 sheets in high boiling point organic solvents enabled by surface functionalization and the controllable recovery of their semiconducting properties directly in solution. This process connects the scalability of chemical exfoliation with the simplicity of solution processing, ultimately enabling a facile method for tuning the metal to semiconductor transitions of MoS2 and WS2 within a liquid medium.


Asunto(s)
Disulfuros/química , Molibdeno/química , Semiconductores , Compuestos de Tungsteno/química , Modelos Moleculares , Conformación Molecular , Soluciones , Solventes/química , Propiedades de Superficie
19.
ACS Nano ; 8(10): 10851-7, 2014 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-25233478

RESUMEN

The palette of two-dimensional materials has expanded beyond graphene in recent years to include the chalcogenides among other systems. However, there is a considerable paucity of methods for controlled synthesis of mono- and/or few-layer two-dimensional materials with desirable quality, reproducibility, and generality. Here we show a facile top-down synthesis approach for ultrathin layers of 2D materials down to monolayer. Our method is based on controlled evaporative thinning of initially large sheets, as deposited by vapor mass-transport. Rather than optimizing conditions for monolayer deposition, our approach makes use of selective evaporation of thick sheets to control the eventual thickness, down to a monolayer, a process which appears to be self-stopping. As a result, 2D sheets with high yield, high reproducibility, and excellent quality can be generated with large (>10 µm) and thin (∼ 1-2 nm) dimensions. Evaporative thinning promises to greatly reduce the difficulty involved in isolating large, mono- and few-layers of 2D materials for subsequent studies.

20.
In Vivo ; 28(5): 967-71, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25189915

RESUMEN

Gastric cancer is the second cause of death from cancer worldwide and its prevalence and mortality rates are still very high in developed countries. Interleukin-10 (IL10) is a pleiotropic cytokine produced by macrophages which can suppress and stimulate the immune response in tumorigenesis signaling. However, the contribution of IL10 genomic variants to gastric cancer is still largely unknown. In the present study, we aimed at investigating the role of IL10 genotypes in gastric cancer risk. The promoter single nucleotide polymorphisms on IL10, A-1082G (rs1800896), T-819C (rs3021097) and A-592C (rs1800872), were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method among 716 Taiwanese people (358 patients gastric cancer and 358 cancer-free controls). The results showed that there was a significant difference between the patient and control groups in the genotypic frequency distribution of IL10 A-1082G genotypes (p=0.0004). In addition, those carrying the G allele were found to have a higher risk for gastric cancer compared with those with the A allele (p=3.19×10(-5)). Furthermore, personal cigarrete smoking habits enhanced the gastric cancer risk for those IL10 A-1082G AG and GG carriers. In conclusion, AG and GG genotype at IL10 A-1082G, together with smoking, synergistically contribute to individual susceptibility for gastric cancer in Taiwan.


Asunto(s)
Interleucina-10/genética , Polimorfismo de Nucleótido Simple , Fumar/efectos adversos , Neoplasias Gástricas/etiología , Anciano , Alelos , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Riesgo , Neoplasias Gástricas/epidemiología , Taiwán
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