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2.
Cell ; 154(2): 297-310, 2013 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-23870121

RESUMEN

The H3K4me3 mark in chromatin is closely correlated with actively transcribed genes, although the mechanisms involved in its generation and function are not fully understood. In vitro studies with recombinant chromatin and purified human factors demonstrate a robust SET1 complex (SET1C)-mediated H3K4 trimethylation that is dependent upon p53- and p300-mediated H3 acetylation, a corresponding SET1C-mediated enhancement of p53- and p300-dependent transcription that reflects a primary effect of SET1C through H3K4 trimethylation, and direct SET1C-p53 and SET1C-p300 interactions indicative of a targeted recruitment mechanism. Complementary cell-based assays demonstrate a DNA-damage-induced p53-SET1C interaction, a corresponding enrichment of SET1C and H3K4me3 on a p53 target gene (p21/WAF1), and a corresponding codependency of H3K4 trimethylation and transcription upon p300 and SET1C. These results establish a mechanism in which SET1C and p300 act cooperatively, through direct interactions and coupled histone modifications, to facilitate the function of p53.


Asunto(s)
Proteína p300 Asociada a E1A/metabolismo , N-Metiltransferasa de Histona-Lisina/metabolismo , Activación Transcripcional , Proteína p53 Supresora de Tumor/metabolismo , Acetilación , Secuencia de Aminoácidos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Daño del ADN , Células HCT116 , Código de Histonas , Histonas/metabolismo , Humanos , Metilación , Datos de Secuencia Molecular , Complejos Multiproteicos/metabolismo , Transcripción Genética
3.
Mol Cell ; 74(2): 268-283.e5, 2019 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-30902546

RESUMEN

Linker histone H1 has been correlated with transcriptional inhibition, but the mechanistic basis of the inhibition and its reversal during gene activation has remained enigmatic. We report that H1-compacted chromatin, reconstituted in vitro, blocks transcription by abrogating core histone modifications by p300 but not activator and p300 binding. Transcription from H1-bound chromatin is elicited by the H1 chaperone NAP1, which is recruited in a gene-specific manner through direct interactions with activator-bound p300 that facilitate core histone acetylation (by p300) and concomitant eviction of H1 and H2A-H2B. An analysis in B cells confirms the strong dependency on NAP1-mediated H1 eviction for induction of the silent CD40 gene and further demonstrates that H1 eviction, seeded by activator-p300-NAP1-H1 interactions, is propagated over a CCCTC-binding factor (CTCF)-demarcated region through a distinct mechanism that also involves NAP1. Our results confirm direct transcriptional inhibition by H1 and establish a gene-specific H1 eviction mechanism through an activator→p300→NAP1→H1 pathway.


Asunto(s)
Factor de Unión a CCCTC/genética , Proteína p300 Asociada a E1A/genética , Proteínas/genética , Transcripción Genética , Acetilación , Linfocitos B/química , Sitios de Unión , Factor de Unión a CCCTC/química , Antígenos CD40/genética , Cromatina/química , Cromatina/genética , Proteína p300 Asociada a E1A/química , Código de Histonas , Histonas/química , Histonas/genética , Humanos , Chaperonas Moleculares/química , Chaperonas Moleculares/genética , Nucleosomas/química , Nucleosomas/genética , Regiones Promotoras Genéticas , Unión Proteica/genética , Proteínas/química , ARNt Metiltransferasas
4.
Cell ; 144(4): 513-25, 2011 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-21335234

RESUMEN

Histone H3K4 methylation is associated with active genes and, along with H3K27 methylation, is part of a bivalent chromatin mark that typifies poised developmental genes in embryonic stem cells (ESCs). However, its functional roles in ESC maintenance and differentiation are not established. Here we show that mammalian Dpy-30, a core subunit of the SET1/MLL histone methyltransferase complexes, modulates H3K4 methylation in vitro, and directly regulates chromosomal H3K4 trimethylation (H3K4me3) throughout the mammalian genome. Depletion of Dpy-30 does not affect ESC self-renewal, but significantly alters the differentiation potential of ESCs, particularly along the neural lineage. The differentiation defect is accompanied by defects in gene induction and in H3K4 methylation at key developmental loci. Our results strongly indicate an essential functional role for Dpy-30 and SET1/MLL complex-mediated H3K4 methylation, as a component of the bivalent mark, at developmental genes during the ESC fate transitions.


Asunto(s)
Células Madre Embrionarias/metabolismo , Histonas/metabolismo , Proteínas Nucleares/metabolismo , Animales , Diferenciación Celular , Línea Celular , Linaje de la Célula , Proteínas de Unión al ADN , Células Madre Embrionarias/citología , Técnicas de Silenciamiento del Gen , Genoma , N-Metiltransferasa de Histona-Lisina/metabolismo , Metilación , Ratones , Neuronas/citología , Proteínas Nucleares/genética , Transcripción Genética , Tretinoina/metabolismo
5.
Proc Natl Acad Sci U S A ; 119(9)2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-35217626

RESUMEN

Acute myeloid leukemias (AMLs) with the NUP98-NSD1 or mixed lineage leukemia (MLL) rearrangement (MLL-r) share transcriptomic profiles associated with stemness-related gene signatures and display poor prognosis. The molecular underpinnings of AML aggressiveness and stemness remain far from clear. Studies with EZH2 enzymatic inhibitors show that polycomb repressive complex 2 (PRC2) is crucial for tumorigenicity in NUP98-NSD1+ AML, whereas transcriptomic analysis reveal that Kdm5b, a lysine demethylase gene carrying "bivalent" chromatin domains, is directly repressed by PRC2. While ectopic expression of Kdm5b suppressed AML growth, its depletion not only promoted tumorigenicity but also attenuated anti-AML effects of PRC2 inhibitors, demonstrating a PRC2-|Kdm5b axis for AML oncogenesis. Integrated RNA sequencing (RNA-seq), chromatin immunoprecipitation followed by sequencing (ChIP-seq), and Cleavage Under Targets & Release Using Nuclease (CUT&RUN) profiling also showed that Kdm5b directly binds and represses AML stemness genes. The anti-AML effect of Kdm5b relies on its chromatin association and/or scaffold functions rather than its demethylase activity. Collectively, this study describes a molecular axis that involves histone modifiers (PRC2-|Kdm5b) for sustaining AML oncogenesis.


Asunto(s)
Histona Demetilasas con Dominio de Jumonji/metabolismo , Leucemia Mieloide Aguda/patología , Proteínas Nucleares/metabolismo , Complejo Represivo Polycomb 2/metabolismo , Proteínas Represoras/metabolismo , Animales , Carcinogénesis , Perfilación de la Expresión Génica , Histona Demetilasas/metabolismo , Humanos , Leucemia Mieloide Aguda/metabolismo , Ratones , Proteínas Oncogénicas/metabolismo , Complejo Represivo Polycomb 2/antagonistas & inhibidores , Unión Proteica , Análisis de Secuencia de ARN/métodos
6.
Int J Cancer ; 154(8): 1443-1454, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38126210

RESUMEN

The cancer burden in China is increasing. We aimed to assess the time trends in the prevalence of 16 modifiable risk factors involved in lifestyle, diet, infection, and air pollution between 1997 and 2025 based on the China Health and Nutrition Survey, the Global Burden of Disease website, and publically available studies. The population attributable fraction (PAF) and its 95% uncertainty interval (UI) from 2007 to 2035 were calculated to quantify the attributable cancer burden in major 12 anatomic sites using the comparative risk assessment method, considering a 10-year lag effect. As a result, 1,559,476 cancer cases (PAF = 54.1%, 95% UI: 36.8%-65.8%) from the 12 anatomic sites were attributable to these modifiable risk factors in 2007, with lung, liver, and gastric cancer raging the top three. It was predicted that by 2035, the attributable cancer cases would reach 1,680,098 (PAF = 44.2%, 95% UI: 29.1%-55.5%), with the top three of lung, liver, and colorectal cancer. Smoking, physical inactivity, insufficient fruit consumption, HBV infection, and Helicobacter pylori infection were the most attributable risk factors in 2007, contributing to 480,352, 233,684, 215,009, 214,455, and 187,305 associated cancer cases, respectively. In 2035, the leading factors for cancer would be smoking, physical inactivity, insufficient fruit intake, HPV infection, and HBV infection, resulting in 427,445, 424,327, 185,144, 156,535, and 154,368 cancer cases, respectively. Intervention strategies should be swiftly established and dynamically altered in response to risk factors like smoking, physical inactivity, poor fruit intake, and infectious factors that may cause a high cancer burden in the Chinese population.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Neoplasias , Humanos , Factores de Riesgo , Fumar/efectos adversos , Fumar/epidemiología , Neoplasias/epidemiología , Neoplasias/etiología
7.
Small ; : e2312129, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38593332

RESUMEN

Lithium (Li) metal is widely recognized as a viable candidate for anode material in future battery technologies due to its exceptional energy density. Nevertheless, the commercial Li foils in common use are too thick (≈100 µm), resulting in a waste of Li resources. Herein, by applying the vacuum evaporation plating technology, the ultra-thin Li foils (VELi) with high purity, strong adhesion, and thickness of less than 10 µm are successfully prepared. The manipulation of evaporation temperature allows for convenient regulation of the thickness of the fabricated Li film. This physical thinning method allows for fast, continuous, and highly accurate mass production. With a current density of 0.5 mA cm-2 for a plating amount of 0.5 mAh cm-2, VELi||VELi cells can stably cycle for 200 h. The maximum utilization of Li is already more than 25%. Furthermore, LiFePO4||VELi full cells present excellent cycling performance at 1 C (1 C = 155 mAh g-1) with a capacity retention rate of 90.56% after 240 cycles. VELi increases the utilization of active Li and significantly reduces the cost of Li usage while ensuring anode cycling and multiplication performance. Vacuum evaporation plating technology provides a feasible strategy for the practical application of ultra-thin Li anodes.

8.
World J Urol ; 42(1): 206, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38561548

RESUMEN

OBJECTIVE: Identification of superficial inguinal lymph nodes during low-risk penile cancer surgery using near-infrared (NIR) fluorescence to improve the accuracy of lymph-node dissection and reduce the incidence of missed micrometastases and complications. METHODS: Thirty-two cases were selected, which were under the criteria of < T1, and no lymph-node metastasis was found with magnetic resonance imaging (MRI) detection. Two groups were randomly divided based on the fluorescence technique, the indocyanine green (ICG) group and the non-ICG group. In the ICG group, the ICG preparation was subcutaneously injected into the edge of the penile tumor 10 min before surgery, and the near-infrared fluorescence imager was used for observation. After the lymph nodes were visualized, the superficial inguinal lymph nodes were removed first, and then, the penis surgery was performed. The non-ICG group underwent superficial inguinal lymph-node dissection and penile surgery. RESULTS: Among the 16 patients in the ICG group, we obtained 11 lymph-node specimens using grayscale values of images (4.13 ± 0.72 vs. 3.00 ± 0.82 P = 0.003) along with shorter postoperative healing time (7.31 ± 1.08 vs. 8.88 ± 2.43 P = 0.025), and less lymphatic leakage (0 vs. 5 P = 0.04) than the 16 patients in the non-ICG group. Out of 11, 3 lymph nodes that are excised were further grouped into fluorescent and non-fluorescent regions (G1/G2) and found to be metastasized. CONCLUSION: Near-infrared fluorescence-assisted superficial inguinal lymph-node dissection in penile carcinoma is accurate and effective, and could reduce surgical complications.


Asunto(s)
Neoplasias del Pene , Humanos , Masculino , Colorantes , Verde de Indocianina , Escisión del Ganglio Linfático/métodos , Ganglios Linfáticos/diagnóstico por imagen , Ganglios Linfáticos/cirugía , Ganglios Linfáticos/patología , Metástasis Linfática/patología , Neoplasias del Pene/diagnóstico por imagen , Neoplasias del Pene/cirugía , Neoplasias del Pene/patología , Biopsia del Ganglio Linfático Centinela/métodos
9.
Prev Med ; 185: 108021, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38821420

RESUMEN

OBJECTIVE: Lifestyle factors after cancer diagnosis could influence cancer survival. This study aimed to investigate the joint effects of smoking, physical activity, alcohol consumption, diet and sleep duration on all-cause, cancer and non-cancer mortality of cancer survivors in UK biobank. METHODS: The follow-up period concluded in December 2021, with post-diagnostic lifestyle factors assessed at baseline. A lifestyle score ranging from 0 to 5 was assigned based on adherence to the selected lifestyle factors. The study employed Cox regression models for hazard ratios (HRs) and Kaplan-Meier for survival rates, with stratified and sensitivity analyses to assess the robustness of our findings under various assumptions. RESULTS: During a median follow-up of 12.7 years, 5652 deaths were documented from 34,184 cancer survivors. Compared to scoring 0-1, the HRs (95% CIs) for all-cause mortality with lifestyle scores of 2, 3, 4, and 5 were 0.70 (95% CI: 0.64, 0.76), 0.57 (0.52, 0.62), 0.50 (0.45, 0.54) and 0.43 (0.38, 0.48), respectively. Specific cancer types, particularly digestive, breast, female reproductive, non-solid, and skin cancers, showed notable benefits from adherence to healthy lifestyle, with the HRs of 0.55 (0.39, 0.79), 0.54 (0.42, 0.70), 0.32 (0.19, 0.53), 0.58 (0.39, 0.86), and 0.36 (0.28, 0.46) for lifestyle score of 5, respectively. Stratified analyses indicated the association was particularly significant among those with normal/lower BMI and higher Townsend Deprivation Index (Pinteraction = 0.001 and < 0.001, respectively). CONCLUSIONS: Healthier lifestyles were significantly linked with reduced mortality among cancer survivors. These findings highlight the need for adherence to healthy lifestyle habits to improve survival.

10.
Analyst ; 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38900434

RESUMEN

Electrochromic visualization of latent fingermarks has already been achieved on conducting surfaces such as stainless steel. However, their enhancement on non-conducting surfaces such as glass via electrochromism has not been reported. Considering the non-conductive nature of substrates, a layer of gold was introduced to the fingermark-bearing surfaces, in which gold was used as the cathodes to assemble electrochromic devices for visualization. The contact between gold nanoparticles of the as-obtained conducting layer in the fingermark region should be affected by the height difference within the fingermark, leading to conductivity differences, which give rise to coloration differences in electrochromic devices. It is demonstrated that 1,1'-dibenzyl-4,4'-bipyridinium dichloride can be used as the electrochromic chromophore for the visualization of latent fingermarks deposited on nonconducting surfaces, and the primary and secondary characteristic information can be obtained. The electrochromic visualization herein solves the problem of electrochromically enhancing latent fingermarks on non-conducting surfaces.

11.
Clin Oral Implants Res ; 35(2): 220-229, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38033198

RESUMEN

OBJECTIVE: Optimal implant planning and placement allows the prosthesis to be well designed to achieve a satisfactory aesthetic and functional outcome. We aimed to compare deviations between implant planning and placement with the assistance of dynamic computer-assisted implant surgery (d-CAIS) or autonomous robotic computer-assisted implant surgery (r-CAIS) methods in a clinical setting. METHODS: The retrospective analysis of medical records between 2021 July and 2022 December was conducted to compare the implantation accuracy of the d-CAIS and r-CAIS system in partially edentulous patients through cone-beam computed tomography. Patient-reported outcomes (PROs) were recorded using a visual analogue scale (VAS). The Kolmogorov-Smirnov test was used to check the data distribution. Student's t-test or Mann-Whitney U-test was used as appropriate, with a defined significant difference (p < .05). RESULTS: Seventy-seven patients were analysed (124 implants), with 38 patients (62 implants) in the d-CAIS group and 39 patients (62 implants) in the r-CAIS group. The differences between d-CAIS and r-CAIS were 4.09 ± 1.79° versus 1.37 ± 0.92° (p < .001) in angular deviation; 1.25 ± 0.54 versus 0.68 ± 0.36 mm (p < .001) in coronal global deviation; 1.39 ± 0.52 versus 0.69 ± 0.36 mm (p < .001) in apical global deviation; the results of the PROMs showed no statistical difference between the two groups. CONCLUSIONS: r-CAIS allows more accurate implant placement than the d-CAIS technology. And both groups achieved overall satisfactory outcomes via VAS (Chinese Clinical Trial Registry ChiCTR2300072004).


Asunto(s)
Implantes Dentales , Procedimientos Quirúrgicos Robotizados , Cirugía Asistida por Computador , Humanos , Implantación Dental Endoósea/métodos , Estudios Retrospectivos , Cirugía Asistida por Computador/métodos , Computadores , Tomografía Computarizada de Haz Cónico , Diseño Asistido por Computadora , Imagenología Tridimensional
12.
Proc Natl Acad Sci U S A ; 118(6)2021 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-33542097

RESUMEN

The chimeric transcription factor E2A-PBX1, containing the N-terminal activation domains of E2A fused to the C-terminal DNA-binding domain of PBX1, results in 5% of pediatric acute lymphoblastic leukemias (ALL). We recently have reported a mechanism for RUNX1-dependent recruitment of E2A-PBX1 to chromatin in pre-B leukemic cells; but the subsequent E2A-PBX1 functions through various coactivators and the general transcriptional machinery remain unclear. The Mediator complex plays a critical role in cell-specific gene activation by serving as a key coactivator for gene-specific transcription factors that facilitates their function through the RNA polymerase II transcriptional machinery, but whether Mediator contributes to aberrant expression of E2A-PBX1 target genes remains largely unexplored. Here we show that Mediator interacts directly with E2A-PBX1 through an interaction of the MED1 subunit with an E2A activation domain. Results of MED1 depletion by CRISPR/Cas9 further indicate that MED1 is specifically required for E2A-PBX1-dependent gene activation and leukemic cell growth. Integrated transcriptome and cistrome analyses identify pre-B cell receptor and cell cycle regulatory genes as direct cotargets of MED1 and E2A-PBX1. Notably, complementary biochemical analyses also demonstrate that recruitment of E2A-PBX1 to a target DNA template involves a direct interaction with DNA-bound RUNX1 that can be further stabilized by EBF1. These findings suggest that E2A-PBX1 interactions with RUNX1 and MED1/Mediator are of functional importance for both gene-specific transcriptional activation and maintenance of E2A-PBX1-driven leukemia. The MED1 dependency for E2A-PBX1-mediated gene activation and leukemogenesis may provide a potential therapeutic opportunity by targeting MED1 in E2A-PBX1+ pre-B leukemia.


Asunto(s)
Carcinogénesis/genética , Proteínas de Homeodominio/metabolismo , Leucemia/genética , Leucemia/patología , Subunidad 1 del Complejo Mediador/metabolismo , Proteínas de Fusión Oncogénica/metabolismo , Transcripción Genética , Linfocitos B/patología , Carcinogénesis/patología , Puntos de Control del Ciclo Celular , Proliferación Celular/genética , Supervivencia Celular , Subunidad alfa 2 del Factor de Unión al Sitio Principal/metabolismo , ADN de Neoplasias/metabolismo , Regulación hacia Abajo/genética , Regulación Leucémica de la Expresión Génica , Genes Relacionados con las Neoplasias , Humanos , Unión Proteica , Estabilidad Proteica
13.
Molecules ; 29(4)2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38398583

RESUMEN

Hydroxylation of aryl sulfonium salts could be realized by utilizing acetohydroxamic acid and oxime as hydroxylative agents in the presence of cesium carbonate as a base, leading to a variety of structurally diverse hydroxylated arenes in 47-95% yields. In addition, the reaction exhibited broad functionality tolerance, and a range of important functional groups (e.g., cyano, nitro, sulfonyl, formyl, keto, and ester) could be well amenable to the mild reaction conditions.

14.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 55(1): 67-73, 2024 Jan 20.
Artículo en Zh | MEDLINE | ID: mdl-38322536

RESUMEN

Objective: To investigate how substrate stiffness regulates the morphology of primary cilia in chondrocytes and to illustrate how Piezo1 mediates the morphology regulation of primary cilia by substrate stiffness. Methods: Polydimethylsiloxane (PDMS) curing agent and the main agent (Dow Corning, Beijing, China) were mixed at the ratio of 1∶10 (stiff), 1∶50 (medium stiffness), and 1∶70 (soft), respectively, to prepare substrate films with the thickness of 1 mm at different levels of stiffness, including stiff substrate of (2.21±0.12) MPa, medium-stiffness substrate of (54.47±6.06) kPa, and soft substrate of (2.13±0.10) kPa. Chondrocytes were cultured with the substrates of three different levels of stiffness. Then, the cells were treated with Tubastatin A (Tub A) to inhibit histone deacetylase 6 (HDAC6), Piezo1 activator Yoda1, and inhibitor GsMTx4, respectively. The effects of HDAC6, Yoda1, and GsMTx4 on chondrocyte morphology and the length of primary cilia were analyzed through immunofluorescence staining. Results: The stiff substrate increased the spread area of the chondrocytes. Immunofluorescence assays showed that the cytoskeleton and the nuclear area of the cells on the stiff substrate were significantly increased (P<0.05) and the primary cilia were significantly extended (P<0.05) compared with those on the medium-stiffness and soft substrates. However, the presence rate of primary cilia was not affected. The HDAC6 activity of chondrocytes increased with the decrease in substrate stiffness. When the activity of HDAC6 was inhibited, the cytoskeletal area, the nuclei area, and the primary cilium length were increased more significantly on the stiff substrate (P<0.05). Further testing showed that Piezo1 activator and inhibitor could regulate the activity of HDAC6 in chondrocytes, and that the length of primary cilia was significantly increased after treatment with the activator Yoda1 (P<0.05). On the other hand, the length of primary cilia was significantly shortened on the stiff substrate after treatment with the inhibitor GsMTx4 (P<0.05). Conclusion: Both substrate stiffness and Piezo1 may affect the morphology of chondrocyte primary cilia by regulating HDAC6 activity.


Asunto(s)
Condrocitos , Cilios , Canales Iónicos , Células Cultivadas , Cilios/fisiología , Citoesqueleto
15.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 41(1): 129-135, 2024 Feb 25.
Artículo en Zh | MEDLINE | ID: mdl-38403613

RESUMEN

The mechanical properties of the cornea in corneal ectasia disease undergo a significant reduction, yet the alterations in mechanical properties within distinct corneal regions remain unclear. In this study, we established a rabbit corneal ectasia model by employing collagenase II to degrade the corneal matrix within a central diameter of 6 mm. Optical coherence tomography was employed for the in vivo assessment of corneal morphology (corneal thickness and corneal curvature) one month after operation. Anisotropy and viscoelastic characteristics of corneal tissue were evaluated through biaxial and uniaxial testing, respectively. The results demonstrated a marked decrease in central corneal thickness, with no significant changes observed in corneal curvature. Under different strains, the elastic modulus of the cornea exhibited no significant differences in the up-down and naso-temporal directions between the control and model groups. However, the cornea in the model group displayed a significantly lower elastic modulus compared to the control group. Specifically, the elastic modulus of the central region cornea in the model group was significantly lower than that of the entire cornea within the same group. Moreover, in comparison to the control group, the cornea in the model group exhibited a significant increase in both creep rate and overall deformation rate. The instantaneous modulus and equilibrium modulus were significantly reduced in the model cornea. No significant differences were observed between the entire cornea and the central cornea concerning these parameters. The results indicate that corneal anisotropy remains unchanged in collagenase-induced ectatic cornea. However, a significant reduction in viscoelastic properties is noticed. This study provides valuable insights for investigating changes in corneal mechanical properties within different regions of ectatic corneal disease.


Asunto(s)
Córnea , Enfermedades de la Córnea , Animales , Conejos , Dilatación Patológica , Anisotropía , Colagenasas
16.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 41(3): 469-475, 2024 Jun 25.
Artículo en Zh | MEDLINE | ID: mdl-38932532

RESUMEN

Accurately evaluating the local biomechanics of arterial wall is crucial for diagnosing and treating arterial diseases. Indentation measurement can be used to evaluate the local mechanical properties of the artery. However, the effects of the indenter's geometric structure and the analysis theory on measurement results remain uncertain. In this paper, four kinds of indenters were used to measure the pulmonary aorta, the proximal thoracic aorta and the distal thoracic aorta in pigs, and the arterial elastic modulus was calculated by Sneddon and Sirghi theory to explore the influence of the indenter geometry and analysis theory on the measured elastic modulus. The results showed that the arterial elastic modulus measured by cylindrical indenter was lower than that measured by spherical indenter. In addition, compared with the calculated results of Sirghi theory, the Sneddon theory, which does not take adhesion forces in account, resulted in slightly larger elastic modulus values. In conclusion, this study provides parametric support for effective measurement of arterial local mechanical properties by millimeter indentation technique.


Asunto(s)
Aorta Torácica , Módulo de Elasticidad , Arteria Pulmonar , Animales , Porcinos , Fenómenos Biomecánicos , Aorta Torácica/fisiología , Aorta Torácica/anatomía & histología , Arteria Pulmonar/fisiología , Estrés Mecánico , Arterias/fisiología
17.
J Virol ; 96(1): e0137221, 2022 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-34643430

RESUMEN

Coronaviral papain-like proteases (PLpros) are essential enzymes that mediate not only the proteolytic processes of viral polyproteins during virus replication but also the deubiquitination and deISGylation of cellular proteins that attenuate host innate immune responses. Therefore, PLpros are attractive targets for antiviral drug development. Here, we report the crystal structure of papain-like protease 2 (PLP2) of porcine epidemic diarrhea virus (PEDV) in complex with ubiquitin (Ub). The X-ray structural analyses reveal that PEDV PLP2 interacts with the Ub substrate mainly through the Ub core region and C-terminal tail. Mutations of Ub-interacting residues resulted in a moderately or completely abolished deubiquitinylating function of PEDV PLP2. In addition, our analyses also indicate that 2-residue-extended blocking loop 2 at the S4 subsite contributes to the substrate selectivity and binding affinity of PEDV PLP2. Furthermore, the PEDV PLP2 Glu99 residue, conserved in alphacoronavirus PLpros, was found to govern the preference of a positively charged P4 residue of peptidyl substrates. Collectively, our data provided structure-based information for the substrate binding and selectivity of PEDV PLP2. These findings may help us gain insights into the deubiquitinating (DUB) and proteolytic functions of PEDV PLP2 from a structural perspective. IMPORTANCE Current challenges in coronaviruses (CoVs) include a comprehensive understanding of the mechanistic effects of associated enzymes, including the 3C-like and papain-like proteases. We have previously reported that the PEDV PLP2 exhibits a broader substrate preference, superior DUB function, and inferior peptidase activity. However, the structural basis for these functions remains largely unclear. Here, we show the high-resolution X-ray crystal structure of PEDV PLP2 in complex with Ub. Integrated structural and biochemical analyses revealed that (i) three Ub core-interacting residues are essential for DUB function, (ii) 2-residue-elongated blocking loop 2 regulates substrate selectivity, and (iii) a conserved glutamate residue governs the substrate specificity of PEDV PLP2. Collectively, our findings provide not only structural insights into the catalytic mechanism of PEDV PLP2 but also a model for developing antiviral strategies.


Asunto(s)
Proteasas Similares a la Papaína de Coronavirus/química , Virus de la Diarrea Epidémica Porcina/química , Coronavirus/química , Coronavirus/clasificación , Coronavirus/enzimología , Proteasas Similares a la Papaína de Coronavirus/genética , Proteasas Similares a la Papaína de Coronavirus/metabolismo , Cristalografía por Rayos X , Mutación , Virus de la Diarrea Epidémica Porcina/enzimología , Virus de la Diarrea Epidémica Porcina/genética , Unión Proteica , Dominios Proteicos , Relación Estructura-Actividad , Especificidad por Sustrato , Ubiquitina/química , Ubiquitina/metabolismo
18.
Exp Eye Res ; 233: 109541, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37321365

RESUMEN

Ocular diseases and treatment related to rhegmatogenous retinal detachment (RRD) are highly correlated with retinal adhesion behavior. Therefore, this paper proposes to study the adhesion behavior of the intact retina. This can provide theoretical guidance for the treatment and research of retinal detachment (RD) related diseases. To systematically analyze this aspect, two experiments were performed on the porcine retina. The pull-off test combined with the modified JKR theory was used to study the adhesion behavior of the vitreoretinal interface, while the peeling test was used to study the adhesion behavior of the chorioretinal interface. In addition, the adhesion phase involved in the pull-off test was simulated and analyzed by building the corresponding finite element method (FEM). The experimental results of adhesion force on the vitreoretinal interface were obtained by pull-off test with five sizes of rigid punch. The experimental value of the pull-off force FPO tends to increase gradually with increasing punch radius in the range of 0.5-4 mm. A comparison of the experimental results with the simulation results shows that they are in a well agreement. And there is no statistical difference between the experimental and theoretical values of the pull-off force FPO. In addition, the values of retinal adhesion work were also obtained by pull-off test. Interestingly, there is a significant scale effect of the retinal work of adhesion. Finally, the peeling test gave a maximum peeling strength TMax of about 13 mN/mm and a stable peeling strength TD of about 11 mN/mm between the retina and the choroid. The pull-off test well shows the process of retinal traction by the diseased vitreous at the beginning of RRD. A comparison of the experimental results with the finite element results verifies the accuracy of the simulation. The peeling test well investigated the adhesion behavior between the retina and the choroid and obtained key biomechanical data (peeling strength, etc.). The combination of the two experiments allows a more systematic study of the whole retina. This research can provide more complete material parameters for finite element modeling of retina-related diseases, and it also can provide the theoretical guidance for individualized design of retinal repair surgery.


Asunto(s)
Desprendimiento de Retina , Enfermedades de la Retina , Animales , Porcinos , Desprendimiento de Retina/cirugía , Desprendimiento de Retina/patología , Vitrectomía/métodos , Retina/patología , Enfermedades de la Retina/patología , Cuerpo Vítreo/patología , Adherencias Tisulares
19.
Exp Eye Res ; 227: 109363, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36584907

RESUMEN

Corneal cross-linking (CXL) has been proved efficiency for treating progressive keratoconus and other corneal ectasia diseases by stabilizing corneal geometry and biomechanics. However, the necessity of repeated CXL treatment in patients is unknown. This study aimed to investigate corneal biomechanical stiffness and change in corneal histopathological characteristics after repeated accelerated CXL (A-CXL) in cat eyes. A-CXL was performed with 0.1% riboflavin applied for 10 min, followed by ultraviolet A irradiation at 30 mW/cm2 for 3 min at 365 nm in 15 domestic cats. Corneas (n = 30) were divided into three groups: one-time accelerated corneal cross-linking (A-CXL*1 group), repeated accelerated corneal cross-linking (A-CXL*2 group), and an untreated control group. In A-CXL*2 group, A-CXL was repeated at 1-month intervals. In vivo ocular examinations were performed pre- and postoperatively. Biomechanical analysis was performed using a biotester biaxial testing system. We used the Mooney-Rivlin strain-energy function to describe corneal material properties. No infection in any case after A-CXL was observed. Biomechanical tests showed that the stress-strain curves of the two A-CXL groups were significantly different from those of the control group (P < 0.01), whereas stress-strain curve of the A-CXL*2 group was similar to that of the A-CXL*1 group (P > 0.05). Delayed epithelial healing and haze were observed 1 month after surgery. Stromal demarcation line depth measured with anterior spectral-domain optical coherence tomography was 187.6 ± 20.4 and 197.1 ± 11.5 µm for the A-CXL*1 and A-CXL*2 groups, respectively (P > 0.05). These results show that A-CXL can increase corneal biomechanics in cat eyes. The biomechanical enhancement of cat corneas treated with repeated A-CXL at 1-month intervals was similar to that of performing a one-time A-CXL. Repeated cross-linking procedures at short intervals may increase the risk of adverse reactions, and more caution should be taken in clinical applications.


Asunto(s)
Queratocono , Fármacos Fotosensibilizantes , Animales , Gatos , Fármacos Fotosensibilizantes/uso terapéutico , Reticulación Corneal , Sustancia Propia/patología , Colágeno/uso terapéutico , Reactivos de Enlaces Cruzados/uso terapéutico , Córnea/patología , Riboflavina/farmacología , Riboflavina/uso terapéutico , Rayos Ultravioleta , Queratocono/tratamiento farmacológico , Queratocono/patología , Topografía de la Córnea
20.
Prev Med ; 175: 107674, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37604289

RESUMEN

Numerous studies have revealed associations between high intake of whole grains and reduced risk of various cancers. Yet, in recent decades, the traditional Chinese diets have been challenged by reduction in whole grains and increase in refined grains. To assess the impact of this dietary transition on cancer prevention, we analyzed the time trend of whole grain intake using nationally representative sampling data of over 15 thousand individuals from the China Health and Nutrition Survey. We applied the comparative risk assessment method to estimate the population attributable fraction of cancers due to insufficient whole grain intake from 1997 to 2011 and projected the trend of whole grain intake and the associated burden of cancers to 2035. We found a significant decrease of approximately 59% of whole grain intake in the Chinese population from 1997 to 2011. Compared with 1997, insufficient intake of whole grains was responsible for 9940 more cases of breast cancer, 12,903 more cases of colorectal cancer and 434 more cases of pancreatic cancer in 2011. Our projections suggest that if every Chinese would consume 125 g whole grain per day as recommended by the latest Chinese Dietary Guidelines, 0.63% bladder cancer, 8.98% breast cancer, 15.85% colorectal cancer, 3.86% esophageal cancer, 2.52% liver cancer and 2.22% pancreatic cancer (totaling 186,659 incident cases) could theoretically be averted by 2035. Even if everyone maintained the 2011 whole grain intake level, an estimated 8.38% of cancer events could still be prevented by 2035.

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