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1.
Nature ; 633(8028): 224-231, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39143215

RESUMEN

Coronaviruses remodel the intracellular host membranes during replication, forming double-membrane vesicles (DMVs) to accommodate viral RNA synthesis and modifications1,2. SARS-CoV-2 non-structural protein 3 (nsp3) and nsp4 are the minimal viral components required to induce DMV formation and to form a double-membrane-spanning pore, essential for the transport of newly synthesized viral RNAs3-5. The mechanism of DMV pore complex formation remains unknown. Here we describe the molecular architecture of the SARS-CoV-2 nsp3-nsp4 pore complex, as resolved by cryogenic electron tomography and subtomogram averaging in isolated DMVs. The structures uncover an unexpected stoichiometry and topology of the nsp3-nsp4 pore complex comprising 12 copies each of nsp3 and nsp4, organized in 4 concentric stacking hexamer rings, mimicking a miniature nuclear pore complex. The transmembrane domains are interdigitated to create a high local curvature at the double-membrane junction, coupling double-membrane reorganization with pore formation. The ectodomains form extensive contacts in a pseudo-12-fold symmetry, belting the pore complex from the intermembrane space. A central positively charged ring of arginine residues coordinates the putative RNA translocation, essential for virus replication. Our work establishes a framework for understanding DMV pore formation and RNA translocation, providing a structural basis for the development of new antiviral strategies to combat coronavirus infection.


Asunto(s)
Membranas Intracelulares , SARS-CoV-2 , Humanos , Arginina/química , Arginina/metabolismo , Microscopía por Crioelectrón , Tomografía con Microscopio Electrónico , Membranas Intracelulares/química , Membranas Intracelulares/metabolismo , Membranas Intracelulares/ultraestructura , Membranas Intracelulares/virología , Modelos Moleculares , Porosidad , Dominios Proteicos , Transporte de ARN , ARN Viral/biosíntesis , ARN Viral/química , ARN Viral/metabolismo , SARS-CoV-2/química , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , SARS-CoV-2/ultraestructura , Proteínas no Estructurales Virales/metabolismo , Proteínas no Estructurales Virales/química , Proteínas no Estructurales Virales/ultraestructura , Replicación Viral , Células HEK293
2.
EMBO J ; 41(23): e111857, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36245269

RESUMEN

Perforin-2 (PFN2, MPEG1) is a key pore-forming protein in mammalian innate immunity restricting intracellular bacteria proliferation. It forms a membrane-bound pre-pore complex that converts to a pore-forming structure upon acidification; but its mechanism of conformational transition has been debated. Here we used cryo-electron microscopy, tomography and subtomogram averaging to determine structures of PFN2 in pre-pore and pore conformations in isolation and bound to liposomes. In isolation and upon acidification, the pre-assembled complete pre-pore rings convert to pores in both flat ring and twisted conformations. On membranes, in situ assembled PFN2 pre-pores display various degrees of completeness; whereas PFN2 pores are mainly incomplete arc structures that follow the same subunit packing arrangements as found in isolation. Both assemblies on membranes use their P2 ß-hairpin for binding to the lipid membrane surface. Overall, these structural snapshots suggest a molecular mechanism for PFN2 pre-pore to pore transition on a targeted membrane, potentially using the twisted pore as an intermediate or alternative state to the flat conformation, with the capacity to cause bilayer distortion during membrane insertion.


Asunto(s)
Liposomas , Mamíferos , Animales , Microscopía por Crioelectrón , Perforina/análisis , Perforina/química , Perforina/metabolismo , Membrana Celular/metabolismo , Liposomas/metabolismo , Membranas
3.
Biochem Genet ; 2024 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-38316654

RESUMEN

Despite many studies on papillary thyroid carcinoma (PTC) in the past few decades, some critical and significant genes remain undiscovered. To explore genes that may play crucial roles in PTC, a detailed analysis of the expression levels, mutations, and clinical significance of Kallikrein-related peptidases (KLKs) family genes in PTC was undertaken to provide new targets for the precise treatment of the disease. A comprehensive analysis of KLK family genes was performed using various online tools, such as GEPIA, Kaplan-Meier Plotter, LinkedOmics, GSCA, TIMER, and Cluego. KLK7, KLK10, and KLK11 were critical factors of KLK family genes. Then, functional assays were carried out on KLK7/10/11 to determine their proliferation, migration, and invasion capabilities in PTC. The mRNA expression levels of KLK7, KLK10, KLK11, and KLK13 were significantly elevated in thyroid carcinoma, while KLK1, KLK2, KLK3 and KLK4 mRNA levels were decreased compared to normal tissues. Correlations between KLK2/7-12/15 expression levels and tumor stage were also observed in thyroid carcinoma. Survival analysis demonstrated that KLK4/5/7/9-12/14 was associated with overall survival in patients with thyroid cancer. Not only were KLK genes strongly associated with cancer-related pathways, but also KLK7/10/11 was associated with immune-cell infiltration. Finally, silencing KLK7/10/11 impaired human papillary thyroid carcinoma cells' growth, migration ability, and invasiveness. The increased expression of KLK7, KLK10, and KLK11 may serve as molecular markers to identify PTC patients. KLK7, KLK10, and KLK11 could be potential prognostic indicators and targets for precision therapy against PTC.

4.
J Struct Biol ; 215(3): 108000, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37467823

RESUMEN

Cryo-electron tomography and subtomogram averaging are rising and fast-evolving imaging techniques to study biological events, providing structural information at an unprecedented resolution while preserving spatial correlation in their native contexts. The latest technology and methodology development ranging from sample preparation to data collection and data processing, has enabled significant advancement in its applications to various biological systems. This review provides an overview of the current technology development enabling high-resolution structural study in situ, highlighting the use of a priori information of biological samples to assess the quality of subtomogram averaging pipeline. We exemplify the applications of this technique to understanding viruses and principles of macromolecule assembly using different biological systems, ranging from in vitro to in situ samples, which provide structural information at different resolutions and contexts.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Virus , Procesamiento de Imagen Asistido por Computador/métodos , Tomografía con Microscopio Electrónico/métodos , Microscopía por Crioelectrón/métodos , Sustancias Macromoleculares/química
5.
Philos Trans A Math Phys Eng Sci ; 381(2240): 20210217, 2023 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-36403635

RESUMEN

In this article, a numerical tool is proposed in the framework of bond-based peridynamics to simulate fatigue crack propagation in composite materials and structures. The cycle-dependent damage-cumulative model derived from Peerlings' law and applied to a bilinear constitutive law is used to evaluate the fatigue degradation of the bond stiffness. Several benchmark cases are studied to validate the proposed approach. Finally, static and fatigue crack propagations in composite systems with single or multi-inclusions are simulated to illustrate the capabilities and characteristics of the developed approach. This article is part of the theme issue 'Ageing and durability of composite materials'.

6.
Immunol Invest ; 51(5): 1407-1422, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34251977

RESUMEN

BACKGROUND: Inflammation and oxidative stress contribute to the pathogenesis of lipopolysaccharide (LPS)-induced acute lung injury (ALI). MicroRNA-762 (miR-762) has been implicated in the progression of inflammation and oxidative stress; however, its role in ALI remains unclear. In this study, we aim to investigate the role and underlying mechanisms of miR-762 in LPS-induced ALI. METHODS: Mice were intravenously injected with miR-762 antagomir, agomir or the negative controls for 3 consecutive days and then received a single intratracheal instillation of LPS (5 mg/kg) for 12 h to establish ALI model. Adenoviral vectors were used to knock down the endogenous SIRT7 expression. RESULTS: An increased miR-762 expression was detected in LPS-treated lungs. miR-762 antagomir significantly reduced inflammation, oxidative stress and ALI in mice, while the mice with miR-762 agomir treatment exhibited a deleterious phenotype. Besides, we found that SIRT7 upregulation was essential for the pulmonoprotective effects of miR-762 antagomir, and that SIRT7 silence completely abolished the anti-inflammatory and anti-oxidant capacities of miR-762 antagomir. CONCLUSION: miR-762 is implicated in the pathogenesis of LPS-induced ALI via modulating inflammation and oxidative stress, which depends on its regulation of SIRT7 expression. It might be a valuable therapeutic target for the treatment of ALI.


Asunto(s)
Lesión Pulmonar Aguda , MicroARNs , Sirtuinas , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/genética , Lesión Pulmonar Aguda/metabolismo , Animales , Antagomirs/farmacología , Progresión de la Enfermedad , Inflamación/genética , Inflamación/metabolismo , Inflamación/patología , Lipopolisacáridos/efectos adversos , Lipopolisacáridos/farmacología , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Pulmón/patología , Ratones , MicroARNs/genética , MicroARNs/metabolismo , Estrés Oxidativo , Sirtuinas/genética , Sirtuinas/metabolismo , Regulación hacia Arriba
7.
Immunopharmacol Immunotoxicol ; 44(1): 47-57, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34783628

RESUMEN

OBJECTIVES: Sepsis-associated acute lung injury (ALI) is a clinically severe respiratory disorder and remains the leading cause of multiple organ failure and mortality. Herein, we used lipopolysaccharide (LPS) to generate sepsis-induced ALI and try to explore the role and mechanism of microRNA-92a-3p (miR-92a-3p) in this process. METHODS: Mice were intravenously injected with miR-92a-3p agomir, antagomir and negative controls for 3 consecutive days and then were intratracheally instillated by LPS (5 mg/kg) for 12 h. To knock down the endogenous A-kinase anchoring protein 1 (AKAP1), mice were intratracheally injected with recombinant adenovirus carrying the short hairpin RNA targeting AKAP1 (shAkap1) at 1 week before LPS administration. RESULTS: miR-92a-3p level was significantly upregulated in the lungs by LPS injection. miR-92a-3p antagomir reduced LPS-induced intrapulmonary inflammation and oxidative stress, thereby preventing pulmonary injury and dysfunction. In contrast, miR-92a-3p agomir aggravated LPS-induced intrapulmonary inflammation, oxidative stress, pulmonary injury and dysfunction. Moreover, we reported that AKAP1 upregulation was required for the beneficial effects of miR-92a-3p antagomir, and that AKAP1 knockdown completely abolished the anti-inflammatory and antioxidant capacities of miR-92a-3p antagomir. CONCLUSION: Our data identify that miR-92a-3p modulates LPS-induced intrapulmonary inflammation, oxidative stress and ALI via AKAP1 in mice.


Asunto(s)
Lesión Pulmonar Aguda , MicroARNs , Sepsis , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/genética , Lesión Pulmonar Aguda/metabolismo , Animales , Lipopolisacáridos/toxicidad , Ratones , MicroARNs/genética , MicroARNs/metabolismo , Estrés Oxidativo
8.
Sensors (Basel) ; 22(10)2022 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-35632031

RESUMEN

In this study, we designed a new type of digital hydraulic transformer using four gear-pump/motor units with a displacement ratio of 20:21:22:23 and two control valve groups that consist of four solenoid directional valves. The driving gear shafts of the four gear-pump/motor units are fixedly connected to achieve synchronous rotation. The two control valve groups are respectively installed through an integrated valve block on the inlet and outlet of each gear-pump/motor unit. With the objective of reducing the installed power and energy consumption of hydraulic traction systems, we propose a new energy-saving hydraulic system based on a digital hydraulic transformer. This hydraulic system uses a digital hydraulic transformer as a pressure/flow control element. By controlling the power on/off states of eight solenoid directional valves, the digital hydraulic transformer can realize a change in output flow and then a change in speed of the hydraulic cylinder piston rod. Through the theoretical derivation and simulation analysis of the hydraulic system pressure/flow change process, and the experimental verification of the built hydraulic traction system based on the experimental platform, a conclusion is drawn that the proposed digital hydraulic transformer can change the output pressure/flow of a hydraulic system through a binary digital control, verifying the feasibility of the pressure change principle of the designed digital hydraulic transformer and the rationality of the hydraulic traction system circuit.

9.
Angew Chem Int Ed Engl ; 61(42): e202210207, 2022 10 17.
Artículo en Inglés | MEDLINE | ID: mdl-35924328

RESUMEN

We reported herein an iridium/silver/acid ternary catalytic system to access bisbenzannulated [6,6]-spiroketals in high efficiency with generally high diastereo- and enantioselectivities (up to >20 : 1 dr, >99 % ee). In this procedure, readily available o-alkynylacetophenones undergo cycloisomerization to generate isochromenes in situ that participate in stereoselective allylation/spiroketalization sequence with 2-(1-hydroxyallyl)phenols. Meanwhile, 2-(1-hydroxyallyl)anilines were also compatible in this cascade reaction, furnishing structurally novel bisbenzannulated [6,6]-spiroaminals with good diastereoselectivities (8 : 1-12 : 1 dr) and excellent enantioselectivities (98 %->99 % ee). Moreover, experimental studies and theoretical calculations were performed to illustrate the reaction mechanism and stereochemistry.


Asunto(s)
Iridio , Plata , Compuestos de Anilina , Catálisis , Furanos , Fenoles , Compuestos de Espiro , Estereoisomerismo
10.
J Cell Mol Med ; 25(9): 4204-4215, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33768729

RESUMEN

This study aimed to investigate the ability of CD146+ subset of ADSCs to repair cartilage defects. In this study, we prepared CD146+ liposome magnetic beads (CD146+ LMB) to isolate CD146+ ADSCs. The cells were induced for chondrogenic differentiation and verified by cartilage-specific mRNA and protein expression. Then a mouse model of cartilage defect was constructed and treated by filling the induced cartilage cells into the damaged joint, to evaluate the function of such cells in the cartilage microenvironment. Our results demonstrated that the CD146+ LMBs we prepared were uniform, small and highly stable, and cell experiments showed that the CD146+ LMB has low cytotoxicity to the ADSCs. ADSCs isolated with CD146+ LMB were all CD146+ , CD105+ , CD166+ and CD73+ . After chondrogenic induction, the cells showed significantly increased expression of cartilage markers Sox9, collagen Ⅱ and aggrecan at protein level and significantly increased Sox9, collagen Ⅱ and aggrecan at mRNA level, and the protein expression and mRNA expression of CD146+ ADSCs group were higher than those of ADSCs group. The CD146+ ADSCs group showed superior tissue repair ability than the ADSCs group and blank control group in the animal experiment, as judged by gross observation, histological observation and histological scoring. The above results proved that CD146+ LMB can successfully isolate the CD146+ ADSCs, and after chondrogenic induction, these cells successfully promoted repair of articular cartilage defects, which may be a new direction of tissue engineering.


Asunto(s)
Enfermedades de los Cartílagos/terapia , Cartílago Articular/citología , Diferenciación Celular , Liposomas/química , Trasplante de Células Madre Mesenquimatosas/métodos , Células Madre Mesenquimatosas/citología , Ingeniería de Tejidos , Animales , Enfermedades de los Cartílagos/etiología , Enfermedades de los Cartílagos/patología , Fenómenos Magnéticos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Andamios del Tejido/química
11.
Sensors (Basel) ; 21(18)2021 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-34577445

RESUMEN

As a complex task, robot sorting has become a research hotspot. In order to enable robots to perform simple, efficient, stable and accurate sorting operations for stacked multi-objects in unstructured scenes, a robot multi-object sorting system is built in this paper. Firstly, the training model of rotating target detection is constructed, and the placement state of five common objects in unstructured scenes is collected as the training set for training. The trained model is used to obtain the position, rotation angle and category of the target object. Then, the instance segmentation model is constructed, and the same data set is made, and the instance segmentation network model is trained. Then, the optimized Mask R-CNN instance segmentation network is used to segment the object surface pixels, and the upper surface point cloud is extracted to calculate the normal vector. Then, the angle obtained by the normal vector of the upper surface and the rotation target detection network is fused with the normal vector to obtain the attitude of the object. At the same time, the grasping order is calculated according to the average depth of the surface. Finally, after the obtained object posture, category and grasping sequence are fused, the performance of the rotating target detection network, the instance segmentation network and the robot sorting system are tested on the established experimental platform. Based on this system, this paper carried out an experiment on the success rate of object capture in a single network and an integrated network. The experimental results show that the multi-object sorting system based on deep learning proposed in this paper can sort stacked objects efficiently, accurately and stably in unstructured scenes.

12.
Sensors (Basel) ; 20(13)2020 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-32630057

RESUMEN

Autonomous vehicles can achieve accurate localization and real-time road information perception using sensors such as global navigation satellite systems (GNSSs), light detection and ranging (LiDAR), and inertial measurement units (IMUs). With road information, vehicles can navigate autonomously to a given position without traffic accidents. However, most of the research on autonomous vehicles has paid little attention to road profile information, which is a significant reference for vehicles driving on uneven terrain. Most vehicles experience violent vibrations when driving on uneven terrain, which reduce the accuracy and stability of data obtained by LiDAR and IMUs. Vehicles with an active suspension system, on the other hand, can maintain stability on uneven roads, which further guarantees sensor accuracy. In this paper, we propose a novel method for road profile estimation using LiDAR and vehicles with an active suspension system. In the former, 3D laser scanners, IMU, and GPS were used to obtain accurate pose information and real-time cloud data points, which were added to an elevation map. In the latter, the elevation map was further processed by a Kalman filter algorithm to fuse multiple cloud data points at the same cell of the map. The model predictive control (MPC) method is proposed to control the active suspension system to maintain vehicle stability, thus further reducing drifts of LiDAR and IMU data. The proposed method was carried out in outdoor environments, and the experiment results demonstrated its accuracy and effectiveness.

13.
Exp Cell Res ; 370(2): 383-388, 2018 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-29966662

RESUMEN

Nod-like receptor pyrin domain-containing proteins (NLRPs) are known to take part in the pathogenesis of chronic liver diseases, including liver fibrosis. However, no known direct role of NLRP6, a member of NLRPs, has been reported in liver fibrosis. Here, we found that NLRP6 expression was decreased in fibrotic and cirrhotic livers. In a human hepatic stellate cell line, LX-2, overexpression of NLRP6 suppressed cell proliferation, hydroxyproline accumulation, as well as the expression of type I and type III collagens (Col-I and Col-III), α-smooth muscle actin (α-SMA) and matrix metalloproteinases (MMP2 and MMP9), whereas NLRP6 knockdown displayed reverse effects. Furthermore, NLRP6 significantly suppressed the phosphorylation of Smad2/3 (p-Smad2/3) and enhanced the expression of protein phosphatase magnesium dependent 1 A (PPM1A), the only phosphatase for Smad2/3. NLRP6 overexpression abrogated TGF-ß1-stimulated hydroxyproline accumulation and p-Smad2/3. Co-immunoprecipitation assay demonstrated that NLRP6 was able to form a complex with PPM1A. NLRP6 overexpression did not change the level of p-Smad2/3 in LX-2 cells with PPM1A knockdown. These data indicated that PPM1A was required for the inhibitory effects of NLRP6 on TGF-ß1/Smad2/3 signaling. In conclusion, our results suggest that NLRP6 exerts anti-fibrotic effects in LX-2 cells via regulating PPM1A/Smad2/3 and that NLRP6 may be an effective target in the treatment of liver fibrosis.


Asunto(s)
Células Estrelladas Hepáticas/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Cirrosis Hepática/metabolismo , Hígado/metabolismo , Línea Celular , Proliferación Celular/fisiología , Colágeno Tipo I/metabolismo , Humanos , Cirrosis Hepática/patología , Fosforilación , Proteína smad3/metabolismo
14.
Sensors (Basel) ; 19(23)2019 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-31766765

RESUMEN

Autonomous vehicles can obtain real-time road information using 3D sensors. With road information, vehicles avoid obstacles through real-time path planning to improve their safety and stability. However, most of the research on driverless vehicles have been carried out on urban even driveways, with little consideration of uneven terrain. For an autonomous full tracked vehicle (FTV), the uneven terrain has a great impact on the stability and safety. In this paper, we proposed a method to predict the pose of the FTV based on accurate road elevation information obtained by 3D sensors. If we could predict the pose of the FTV traveling on uneven terrain, we would not only control the active suspension system but also change the driving trajectory to improve the safety and stability. In the first, 3D laser scanners were used to get real-time cloud data points of the terrain for extracting the elevation information of the terrain. Inertial measurement units (IMUs) and GPS are essential to get accurate attitude angle and position information. Then, the dynamics model of the FTV was established to calculate the vehicle's pose. Finally, the Kalman filter was used to improve the accuracy of the predicted pose. Compared to the traditional method of driverless vehicles, the proposed approach was more suitable for autonomous FTV. The real-world experimental result demonstrated the accuracy and effectiveness of our approach.

15.
Int Wound J ; 16(3): 793-799, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30767371

RESUMEN

Some types of skin and soft tissue tumours may be misdiagnosed as scars because of the scar-like manifestation or the history of injury. It is generally believed that injuries will activate wound healing, ultimately ending in fibrosis. Because of the tumour-promoting properties of both the microenvironment of the wound and the wound-healing process that may go awry, there is a likelihood that injuries may trigger tumour growth. From 2012 to 2016, we treated four patients who underwent unsuccessful treatments because of the misdiagnosis of scars or keloids. Upon the pathological diagnoses of skin and soft tissue tumours in the four cases, extended resection of the tumours was performed. Recurrence was not observed up to the last follow up. Since then, soft tissue tumours have much greater visibility and are considered during diagnosis if a wound is presented with the atypical appearance of scar after injuries. Under these circumstances, biopsy should be conducted.


Asunto(s)
Cicatriz/fisiopatología , Cicatriz/cirugía , Errores Diagnósticos , Neoplasias Cutáneas/diagnóstico , Neoplasias Cutáneas/fisiopatología , Neoplasias Cutáneas/cirugía , Cicatrización de Heridas/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
16.
J Cell Physiol ; 233(10): 7047-7056, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29744878

RESUMEN

Photochemical tissue bonding (PTB) has been found to promote the healing of Achilles tendon tissue injury and to reduce postoperative complications. However, the underlying cellular and molecular mechanisms are not clear. In this study, the cell proliferation, ROS generation, migration and the protein expression of DNM2, NF-κB p65, TGF-ß1 and VEGF in tenocytes after PTB treatment were measured by CCK-8, flow cytometry, Transwell and western blot assay, respectively. And those in tenocytes after DNM2 silencing or overexpressing or treatment with inhibitors of NF-κB, ROS and RhoA were also measured. Our results showed that 10 mW PTB treatment for 80 and 120 s significantly increased cell proliferation and increased ROS generation in tenocytes. 10 mW PTB treatment for 40 and 80 s significantly activated RhoA and increased the protein expression of DNM2, NF-κB p65, TGF-ß1 and VEGF, but 10 mW PTB treatment for 120 s decreased the protein expression of those. DNM2 silencing significantly suppressed cell migration and the expression of DNM2, TGF-ß1, and VEGF in tenocytes after PTB treatment (10 mW, 80 s), which was inhibited by DNM2 overexpression. Individual treatment with inhibitor of NF-κB, ROS, and RhoA in tenocytes showed decreased protein expression of DNM2, TGF-ß1, and VEGF. Moreover, in vivo experiment found that PTB treatment significantly inhibited cell apoptosis and the expression of DNM2, NF-κB p65, RhoA, TGF-ß1, and VEGF in a time-dependent manner. Taken together, our results suggest that PTB promotes the proliferation and migration of injured tenocytes through ROS/RhoA/NF-κB/DNM2 signaling pathway.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Dinamina II/metabolismo , Fármacos Fotosensibilizantes/farmacología , Especies Reactivas de Oxígeno/metabolismo , Tenocitos/metabolismo , Movimiento Celular/fisiología , Proliferación Celular/fisiología , Dinaminas/efectos de los fármacos , Dinaminas/metabolismo , Humanos , FN-kappa B/metabolismo , Fosforilación/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Tenocitos/efectos de los fármacos , Proteína de Unión al GTP rhoA/metabolismo
17.
Biochem J ; 474(4): 539-556, 2017 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-27974389

RESUMEN

Kindlins co-activate integrins alongside talin. They possess, like talin, a FERM domain (4.1-erythrin-radixin-moiesin domain) comprising F0-F3 subdomains, but with a pleckstrin homology (PH) domain inserted in the F2 subdomain that enables membrane association. We present the crystal structure of murine kindlin-3 PH domain determined at a resolution of 2.23 Šand characterise its lipid binding using biophysical and computational approaches. Molecular dynamics simulations suggest flexibility in the PH domain loops connecting ß-strands forming the putative phosphatidylinositol phosphate (PtdInsP)-binding site. Simulations with PtdInsP-containing bilayers reveal that the PH domain associates with PtdInsP molecules mainly via the positively charged surface presented by the ß1-ß2 loop and that it binds with somewhat higher affinity to PtdIns(3,4,5)P3 compared with PtdIns(4,5)P2 Surface plasmon resonance (SPR) with lipid headgroups immobilised and the PH domain as an analyte indicate affinities of 300 µM for PtdIns(3,4,5)P3 and 1 mM for PtdIns(4,5)P2 In contrast, SPR studies with an immobilised PH domain and lipid nanodiscs as the analyte show affinities of 0.40 µM for PtdIns(3,4,5)P3 and no affinity for PtdIns(4,5)P2 when the inositol phosphate constitutes 5% of the total lipids (∼5 molecules per nanodisc). Reducing the PtdIns(3,4,5)P3 composition to 1% abolishes nanodisc binding to the PH domain, as does site-directed mutagenesis of two lysines within the ß1-ß2 loop. Binding of PtdIns(3,4,5)P3 by a canonical PH domain, Grp1, is not similarly influenced by SPR experimental design. These data suggest a role for PtdIns(3,4,5)P3 clustering in the binding of some PH domains and not others, highlighting the importance of lipid mobility and clustering for the biophysical assessment of protein-membrane interactions.


Asunto(s)
Proteínas del Citoesqueleto/química , Fosfatidilcolinas/química , Fosfatidilinositoles/química , Fosfatidilserinas/química , Dominios Homólogos a Pleckstrina , Receptores Citoplasmáticos y Nucleares/química , Secuencia de Aminoácidos , Animales , Sitios de Unión , Clonación Molecular , Cristalografía por Rayos X , Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Cinética , Ratones , Simulación de Dinámica Molecular , Fosfatidilcolinas/metabolismo , Fosfatidilinositoles/metabolismo , Fosfatidilserinas/metabolismo , Unión Proteica , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Dominios y Motivos de Interacción de Proteínas , Receptores Citoplasmáticos y Nucleares/genética , Receptores Citoplasmáticos y Nucleares/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido
18.
J Infect Dis ; 214(4): 556-64, 2016 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-27354370

RESUMEN

BACKGROUND: In recent decades, the GII.4 norovirus genotype has predominated in epidemics worldwide and been associated with an increased rate of evolutionary change. In 2014, a novel GII.17 variant emerged and persisted, causing large outbreaks of gastroenteritis in China and sporadic infections globally. The origin, evolution, and transmission history of this new variant are largely unknown. METHODS: We generated 103 full capsid and 8 whole-genome sequences of GII.17 strains collected between August 2013 and November 2015 in Guangdong, China. Phylogenetic analyses were performed by integrating our data with those for all publically available GII.17 sequences. RESULTS: The novel emergent lineage GII.17_Kawasaki_2014 most likely originated from Africa around 2001 and evolved at a rate of 5.6 × 10(-3) substitutions/site/year. Within this lineage, a new variant containing several important amino acid changes emerged around August 2013 and caused extensive epidemics in 2014-2015. The phylodynamic and epidemic history of the GII.17_Kawasaki lineage shows similarities with the pattern observed for GII.4 norovirus evolution. Virus movements from Hong Kong to neighboring coastal cities were frequently observed. CONCLUSIONS: Our results provide new insights into GII.17 norovirus evolution and transmission and highlight the potential for a rare norovirus genotype to rapidly replace existing strains and cause local epidemics.


Asunto(s)
Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/virología , Evolución Molecular , Variación Genética , Genotipo , Norovirus/clasificación , Norovirus/aislamiento & purificación , África , Infecciones por Caliciviridae/transmisión , China , Análisis por Conglomerados , Transmisión de Enfermedad Infecciosa , Hong Kong/epidemiología , Humanos , Epidemiología Molecular , Norovirus/genética , Filogenia , ARN Viral/genética , Estudios Retrospectivos , Análisis de Secuencia de ADN , Homología de Secuencia
19.
Lasers Surg Med ; 48(5): 530-7, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26996284

RESUMEN

BACKGROUND AND OBJECTIVE: Colonic anastomotic failure is a dreaded complication, and multiple surgical techniques have failed to eliminate it. Photochemical tissue bonding (PTB) is a method of sealing tissue surfaces by light-activated crosslinking. We evaluated if a human amniotic membrane (HAM), sealed over the anastomotic line by PTB, increases the anastomotic strength. STUDY DESIGN: Sprague-Dawley rats underwent midline laparotomy followed by surgical transection of the left colon. Animals were randomized to colonic anastomosis by one of the following methods (20 per group): single-layer continuous circumferential suture repair (SR); SR with a HAM wrap attached by suture (SR+ HAM-S); SR with HAM bonded photochemically over the anastomotic site using 532 nm light (SR+ HAM-PTB); approximation of the bowel ends with only three sutures and sealing with HAM-PTB (3+ HAM-PTB). A control group underwent laparotomy alone with no colon resection (NR). Sub-groups (n = 10) were sacrificed at days 3 and 7 post-operatively and adhesions were evaluated. A 6 cm section of colon was then removed and strength of anastomosis evaluated by burst pressure (BP) measurement. RESULTS: A fourfold increase in BP was observed in the SR+ HAM-PTB group compared to suture repair alone (94 ± 3 vs. 25 ± 8 mm Hg, P < 0.0001) at day 3. At day 7 the burst pressures were 165 ± 40 and 145 ± 31 mm Hg (P = 1), respectively. A significant decrease in peri-anastomotic adhesions was observed in the SR+ HAM-PTB group compared to the SR group at both time points (P < 0.001). CONCLUSION: Sealing sutured colonic anastomotic lines with HAM-PTB increases the early strength of the repair and reduces peri-anastomotic adhesions. Lasers Surg. Med. 48:530-537, 2016. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Amnios/cirugía , Fuga Anastomótica/prevención & control , Colon/cirugía , Fotoquimioterapia/métodos , Adherencias Tisulares/prevención & control , Técnicas de Cierre de Heridas , Anastomosis Quirúrgica/métodos , Animales , Humanos , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Adherencias Tisulares/etiología , Resultado del Tratamiento
20.
BMC Musculoskelet Disord ; 17: 150, 2016 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-27052304

RESUMEN

BACKGROUND: Recent studies have shown that autophagy was associated with the development of osteoarthritis (OA), the purpose of this research was to determine the exact role of autophagy in OA and investigate effective therapeutic drugs to inhibit the pathological progression of OA. METHODS: In this study, a cellular OA model was generated by stimulating SW1353 cells with IL-1ß and a rabbit OA model was established by intra-articular injection of collagenase, followed by treatment with Torin 1 or 3-Methyladenine (3-MA). The mRNA expression levels of VEGF, MMP-13 and TIMP-1 were determined by quantitative real-time PCR. The caitilage degeneration was examined by histological evaluation, chondrocytes degeneration and autophagosomes were observed by transmission electron microscopy. Expression levels of Beclin-1 and LC3 were evaluated by western blotting and immunofluorescence. RESULTS: The degeneration of SW 1353 cells, cartilage and chondrocytes was related to the loss of autophagy in experimental OA. 3-MA increased the severity of degeneration of cells and cartilage by autophagy inhibition, while Torin 1 reduced that by autophagy activation. CONCLUSIONS: The loss of autophagy is linked with the experimental OA and autophagy may play a protective role in the pathogenesis of OA. Treatment of Torin 1 can inhibit the degenerative changes of experimental OA by activating autophagy and it may be a useful therapeutic drug for OA.


Asunto(s)
Artritis Experimental/tratamiento farmacológico , Autofagia/efectos de los fármacos , Cartílago/efectos de los fármacos , Condrocitos/efectos de los fármacos , Naftiridinas/farmacología , Adenina/análogos & derivados , Adenina/farmacología , Animales , Proteínas Reguladoras de la Apoptosis/metabolismo , Artritis Experimental/metabolismo , Artritis Experimental/patología , Beclina-1 , Cartílago/metabolismo , Cartílago/ultraestructura , Línea Celular Tumoral , Condrocitos/metabolismo , Condrocitos/ultraestructura , Citoprotección , Humanos , Masculino , Metaloproteinasa 13 de la Matriz/genética , Metaloproteinasa 13 de la Matriz/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Conejos , Índice de Severidad de la Enfermedad , Inhibidor Tisular de Metaloproteinasa-1/genética , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo
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