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1.
Cell Rep ; 43(2): 113717, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38285738

RESUMEN

The homeostatic regulation of serine palmitoyltransferase (SPT) activity in yeast involves N-terminal phosphorylation of Orm proteins, while higher eukaryotes lack these phosphorylation sites. Although recent studies have indicated a conserved ceramide-mediated feedback inhibition of the SPT-ORM/ORMDL complex in higher eukaryotes, its conservation and relationship with phosphorylation regulation in yeast remain unclear. Here, we determine the structure of the yeast SPT-Orm2 complex in a dephosphomimetic state and identify an evolutionarily conserved ceramide-sensing site. Ceramide stabilizes the dephosphomimetic Orm2 in an inhibitory conformation, facilitated by an intramolecular ß-sheet between the N- and C-terminal segments of Orm2. Moreover, we find that a phosphomimetic mutant of Orm2, positioned adjacent to its intramolecular ß-sheet, destabilizes the inhibitory conformation of Orm2. Taken together, our findings suggest that both Orm dephosphorylation and ceramide binding are crucial for suppressing SPT activity in yeast. This highlights a distinctive regulatory mechanism in yeast involving the collaborative actions of phosphorylation and ceramide.


Asunto(s)
Ceramidas , Proteínas de Saccharomyces cerevisiae , Ceramidas/metabolismo , Saccharomyces cerevisiae/metabolismo , Esfingolípidos/metabolismo , Fosforilación , Proteínas/metabolismo , Serina C-Palmitoiltransferasa/genética , Serina C-Palmitoiltransferasa/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
2.
EMBO J ; 42(24): e114889, 2023 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-37953642

RESUMEN

Ceramide synthases (CerS) catalyze ceramide formation via N-acylation of a sphingoid base with a fatty acyl-CoA and are attractive drug targets for treating numerous metabolic diseases and cancers. Here, we present the cryo-EM structure of a yeast CerS complex, consisting of a catalytic Lac1 subunit and a regulatory Lip1 subunit, in complex with C26-CoA substrate. The CerS holoenzyme exists as a dimer of Lac1-Lip1 heterodimers. Lac1 contains a hydrophilic reaction chamber and a hydrophobic tunnel for binding the CoA moiety and C26-acyl chain of C26-CoA, respectively. Lip1 interacts with both the transmembrane region and the last luminal loop of Lac1 to maintain the proper acyl chain binding tunnel. A lateral opening on Lac1 serves as a potential entrance for the sphingoid base substrate. Our findings provide a template for understanding the working mechanism of eukaryotic ceramide synthases and may facilitate the development of therapeutic CerS modulators.


Asunto(s)
Ceramidas , Proteínas de Saccharomyces cerevisiae , Ceramidas/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Oxidorreductasas/metabolismo , Proteínas de la Membrana/metabolismo
3.
Eur Thyroid J ; 12(6)2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-37855414

RESUMEN

Background: Incidence rates of papillary thyroid cancer (PTC) have increased rapidly, with incidentally detected cancers contributing a large proportion. We aimed to explore the impact of incidental detection on thyroid cancer-specific and competing mortality among PTC patients. Methods: We conducted a retrospective cohort study of PTC patients at a cancer center in Guangzhou. Baseline information on detection route and other covariates were collected between 2010 and 2018, and death outcome was followed up for each patient. Cumulative incidence functions were used to estimate the mortality risk of thyroid cancer and competing risk. Cause-specific hazard models were then utilized to explore the association between detection routes and PTC-specific and competing mortality. Results: Of the 2874 patients included, 2011 (70.0%) were detected incidentally, and the proportion increased from 36.9% in 2011 to 82.3% in 2018. During a median follow-up of 5.6 years, 42 deaths occurred, with 60% of them due to competing causes. The probability of competing mortality at 5 years in the non-incidental group and incidental group was 1.4% and 0.4%, respectively, and PTC-specific mortality in the non-incidental group and incidental group was 1.0% and 0.1%, respectively. After adjusting for covariates, the HRs of incidental detection were 0.13 (95% CI: 0.04-0.46; P = 0.01) and 0.47 (95% CI: 0.20-1.10; P = 0.10) on PTC-specific mortality and competing mortality, respectively. Conclusions: Incidental detection is associated with a lower risk of PTC-specific and competing mortality. Under the context of increasing magnitude of overdiagnosis, incorporation of detection route in clinical decision-making might be helpful to identify patients who might benefit from more extensive or conservative therapeutic strategies.


Asunto(s)
Neoplasias de la Tiroides , Humanos , Cáncer Papilar Tiroideo/diagnóstico , Estudios Retrospectivos , Neoplasias de la Tiroides/diagnóstico , Riesgo , Incidencia
4.
Entropy (Basel) ; 25(9)2023 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-37761562

RESUMEN

Hypergraphs have become an accurate and natural expression of high-order coupling relationships in complex systems. However, applying high-order information from networks to vital node identification tasks still poses significant challenges. This paper proposes a von Neumann entropy-based hypergraph vital node identification method (HVC) that integrates high-order information as well as its optimized version (semi-SAVC). HVC is based on the high-order line graph structure of hypergraphs and measures changes in network complexity using von Neumann entropy. It integrates s-line graph information to quantify node importance in the hypergraph by mapping hyperedges to nodes. In contrast, semi-SAVC uses a quadratic approximation of von Neumann entropy to measure network complexity and considers only half of the maximum order of the hypergraph's s-line graph to balance accuracy and efficiency. Compared to the baseline methods of hyperdegree centrality, closeness centrality, vector centrality, and sub-hypergraph centrality, the new methods demonstrated superior identification of vital nodes that promote the maximum influence and maintain network connectivity in empirical hypergraph data, considering the influence and robustness factors. The correlation and monotonicity of the identification results were quantitatively analyzed and comprehensive experimental results demonstrate the superiority of the new methods. At the same time, a key non-trivial phenomenon was discovered: influence does not increase linearly as the s-line graph orders increase. We call this the saturation effect of high-order line graph information in hypergraph node identification. When the order reaches its saturation value, the addition of high-order information often acts as noise and affects propagation.

5.
Nat Commun ; 14(1): 3475, 2023 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-37308477

RESUMEN

The ORM/ORMDL family proteins function as regulatory subunits of the serine palmitoyltransferase (SPT) complex, which is the initiating and rate-limiting enzyme in sphingolipid biosynthesis. This complex is tightly regulated by cellular sphingolipid levels, but the sphingolipid sensing mechanism is unknown. Here we show that purified human SPT-ORMDL complexes are inhibited by the central sphingolipid metabolite ceramide. We have solved the cryo-EM structure of the SPT-ORMDL3 complex in a ceramide-bound state. Structure-guided mutational analyses reveal the essential function of this ceramide binding site for the suppression of SPT activity. Structural studies indicate that ceramide can induce and lock the N-terminus of ORMDL3 into an inhibitory conformation. Furthermore, we demonstrate that childhood amyotrophic lateral sclerosis (ALS) variants in the SPTLC1 subunit cause impaired ceramide sensing in the SPT-ORMDL3 mutants. Our work elucidates the molecular basis of ceramide sensing by the SPT-ORMDL complex for establishing sphingolipid homeostasis and indicates an important role of impaired ceramide sensing in disease development.


Asunto(s)
Esclerosis Amiotrófica Lateral , Ceramidas , Humanos , Niño , Esfingolípidos , Sitios de Unión , Homeostasis
6.
Nonlinear Dyn ; : 1-20, 2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-37361005

RESUMEN

This study aims at modeling the universal failure in preventing the outbreak of COVID-19 via real-world data from the perspective of complexity and network science. Through formalizing information heterogeneity and government intervention in the coupled dynamics of epidemic and infodemic spreading, first, we find that information heterogeneity and its induced variation in human responses significantly increase the complexity of the government intervention decision. The complexity results in a dilemma between the socially optimal intervention that is risky for the government and the privately optimal intervention that is safer for the government but harmful to the social welfare. Second, via counterfactual analysis against the COVID-19 crisis in Wuhan, 2020, we find that the intervention dilemma becomes even worse if the initial decision time and the decision horizon vary. In the short horizon, both socially and privately optimal interventions agree with each other and require blocking the spread of all COVID-19-related information, leading to a negligible infection ratio 30 days after the initial reporting time. However, if the time horizon is prolonged to 180 days, only the privately optimal intervention requires information blocking, which would induce a catastrophically higher infection ratio than that in the counterfactual world where the socially optimal intervention encourages early-stage information spread. These findings contribute to the literature by revealing the complexity incurred by the coupled infodemic-epidemic dynamics and information heterogeneity to the governmental intervention decision, which also sheds insight into the design of an effective early warning system against the epidemic crisis in the future.

7.
Sci Adv ; 9(13): eadg0728, 2023 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-36989369

RESUMEN

The serine palmitoyltransferase (SPT) complex catalyzes the first and rate-limiting step in sphingolipid biosynthesis in all eukaryotes. ORM/ORMDL proteins are negative regulators of SPT that respond to cellular sphingolipid levels. However, the molecular basis underlying ORM/ORMDL-dependent homeostatic regulation of SPT is not well understood. We determined the cryo-electron microscopy structure of Arabidopsis SPT-ORM1 complex, composed of LCB1, LCB2a, SPTssa, and ORM1, in an inhibited state. A ceramide molecule is sandwiched between ORM1 and LCB2a in the cytosolic membrane leaflet. Ceramide binding is critical for the ORM1-dependent SPT repression, and dihydroceramides and phytoceramides differentially affect this repression. A hybrid ß sheet, formed by the amino termini of ORM1 and LCB2a and induced by ceramide binding, stabilizes the amino terminus of ORM1 in an inhibitory conformation. Our findings provide mechanistic insights into sphingolipid homeostatic regulation via the binding of ceramide to the SPT-ORM/ORMDL complex that may have implications for plant-specific processes such as the hypersensitive response for microbial pathogen resistance.


Asunto(s)
Arabidopsis , Esfingolípidos , Esfingolípidos/metabolismo , Arabidopsis/metabolismo , Serina C-Palmitoiltransferasa/genética , Serina C-Palmitoiltransferasa/metabolismo , Microscopía por Crioelectrón , Proteínas de la Membrana/metabolismo , Ceramidas/metabolismo , Homeostasis
8.
Chaos ; 33(1): 013104, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36725627

RESUMEN

Hypergraphs that can depict interactions beyond pairwise edges have emerged as an appropriate representation for modeling polyadic relations in complex systems. With the recent surge of interest in researching hypergraphs, the centrality problem has attracted much attention due to the challenge of how to utilize higher-order structure for the definition of centrality metrics. In this paper, we propose a new centrality method (HGC) on the basis of the gravity model as well as a semi-local HGC, which can achieve a balance between accuracy and computational complexity. Meanwhile, two comprehensive evaluation metrics, i.e., a complex contagion model in hypergraphs, which mimics the group influence during the spreading process and network s-efficiency based on the higher-order distance between nodes, are first proposed to evaluate the effectiveness of our methods. The results show that our methods can filter out nodes that have fast spreading ability and are vital in terms of hypergraph connectivity.

9.
iScience ; 25(6): 104446, 2022 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-35677641

RESUMEN

Quantifying structural dissimilarities between networks is a fundamental and challenging problem in network science. Previous network comparison methods are based on the structural features, such as the length of shortest path and degree, which only contain part of the topological information. Therefore, we propose an efficient network comparison method based on network embedding, which considers the global structural information. In detail, we first construct a distance matrix for each network based on the distances between node embedding vectors derived from DeepWalk. Then, we define the dissimilarity between two networks based on Jensen-Shannon divergence of the distance distributions. Experiments on both synthetic and empirical networks show that our method outperforms the baseline methods and can distinguish networks well. In addition, we show that our method can capture network properties, e.g., average shortest path length and link density. Moreover, the experiment of modularity further implies the functionality of our method.

10.
Sci Adv ; 8(14): eabn3727, 2022 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-35394827

RESUMEN

The adenosine 5'-triphosphate (ATP)-binding cassette (ABC) transporter ABCA3 plays a critical role in pulmonary surfactant biogenesis. Mutations in human ABCA3 have been recognized as the most frequent causes of inherited surfactant dysfunction disorders. Despite two decades of research, in vitro biochemical and structural studies of ABCA3 are still lacking. Here, we report the cryo-EM structures of human ABCA3 in two distinct conformations, both at resolution of 3.3 Å. In the absence of ATP, ABCA3 adopts a "lateral-opening" conformation with the lateral surfaces of transmembrane domains (TMDs) exposed to the membrane and features two positively charged cavities within the TMDs as potential substrate binding sites. ATP binding induces pronounced conformational changes, resulting in the collapse of the potential substrate binding cavities. Our results help to rationalize the disease-causing mutations in human ABCA3 and suggest a conserved "lateral access and extrusion" mechanism for both lipid export and import mediated by ABCA transporters.


Asunto(s)
Transportadoras de Casetes de Unión a ATP , Surfactantes Pulmonares , Transportadoras de Casetes de Unión a ATP/química , Adenosina Trifosfato/metabolismo , Microscopía por Crioelectrón , Humanos , Lipoproteínas/metabolismo , Mutación , Surfactantes Pulmonares/metabolismo , Tensoactivos
11.
IEEE/ACM Trans Comput Biol Bioinform ; 19(4): 2231-2240, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-33656997

RESUMEN

With the advances in gene sequencing technologies, millions of somatic mutations have been reported in the past decades, but mining cancer driver genes with oncogenic mutations from these data remains a critical and challenging area of research. In this study, we proposed a network-based classification method for identifying cancer driver genes with merging the multi-biological information. In this method, we construct a cancer specific genetic network from the human protein-protein interactome (PPI) to mine the network structure attributes, and combine biological information such as mutation frequency and differential expression of genes to achieve accurate prediction of cancer driver genes. Across seven different cancer types, the proposed algorithm always achieves high prediction accuracy, which is superior to the existing advanced methods. In the analysis of the predicted results, about 40 percent of the top 10 candidate genes overlap with the Cancer Gene Census database. Interestingly, the feature comparison indicates that the network based features are still more important than the biological features, including the mutation frequency and genetic differential expression. Further analyses also show that the integration of network structure attributes and biological information is valuable for predicting new cancer driver genes.


Asunto(s)
Neoplasias , Mapas de Interacción de Proteínas , Algoritmos , Redes Reguladoras de Genes/genética , Humanos , Mutación/genética , Neoplasias/genética , Mapas de Interacción de Proteínas/genética
12.
Nat Commun ; 12(1): 3853, 2021 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-34158497

RESUMEN

Human ATP-binding cassette (ABC) subfamily A (ABCA) transporters mediate the transport of various lipid compounds across the membrane. Mutations in human ABCA transporters have been described to cause severe hereditary disorders associated with impaired lipid transport. However, little is known about the mechanistic details of substrate recognition and translocation by ABCA transporters. Here, we present three cryo-EM structures of human ABCA4, a retina-specific ABCA transporter, in distinct functional states at resolutions of 3.3-3.4 Å. In the nucleotide-free state, the two transmembrane domains (TMDs) exhibit a lateral-opening conformation, allowing the lateral entry of substrate from the lipid bilayer. The N-retinylidene-phosphatidylethanolamine (NRPE), the physiological lipid substrate of ABCA4, is sandwiched between the two TMDs in the luminal leaflet and is further stabilized by an extended loop from extracellular domain 1. In the ATP-bound state, the two TMDs display a closed conformation, which precludes the substrate binding. Our study provides a molecular basis to understand the mechanism of ABCA4-mediated NRPE recognition and translocation, and suggests a common 'lateral access and extrusion' mechanism for ABCA-mediated lipid transport.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/química , Transportadoras de Casetes de Unión a ATP/metabolismo , Fosfatidiletanolaminas/metabolismo , Dominios Proteicos , Retinoides/metabolismo , Transportadoras de Casetes de Unión a ATP/ultraestructura , Adenosina Trifosfato/metabolismo , Transporte Biológico , Membrana Celular/metabolismo , Microscopía por Crioelectrón , Humanos , Modelos Moleculares , Fosfolípidos/metabolismo , Unión Proteica
13.
Bioinformatics ; 37(1): 82-88, 2021 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-33416857

RESUMEN

MOTIVATION: Tumor stratification has a wide range of biomedical and clinical applications, including diagnosis, prognosis and personalized treatment. However, cancer is always driven by the combination of mutated genes, which are highly heterogeneous across patients. Accurately subdividing the tumors into subtypes is challenging. RESULTS: We developed a network-embedding based stratification (NES) methodology to identify clinically relevant patient subtypes from large-scale patients' somatic mutation profiles. The central hypothesis of NES is that two tumors would be classified into the same subtypes if their somatic mutated genes located in the similar network regions of the human interactome. We encoded the genes on the human protein-protein interactome with a network embedding approach and constructed the patients' vectors by integrating the somatic mutation profiles of 7344 tumor exomes across 15 cancer types. We firstly adopted the lightGBM classification algorithm to train the patients' vectors. The AUC value is around 0.89 in the prediction of the patient's cancer type and around 0.78 in the prediction of the tumor stage within a specific cancer type. The high classification accuracy suggests that network embedding-based patients' features are reliable for dividing the patients. We conclude that we can cluster patients with a specific cancer type into several subtypes by using an unsupervised clustering algorithm to learn the patients' vectors. Among the 15 cancer types, the new patient clusters (subtypes) identified by the NES are significantly correlated with patient survival across 12 cancer types. In summary, this study offers a powerful network-based deep learning methodology for personalized cancer medicine. AVAILABILITY AND IMPLEMENTATION: Source code and data can be downloaded from https://github.com/ChengF-Lab/NES. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

14.
Math Biosci Eng ; 17(4): 3710-3720, 2020 05 21.
Artículo en Inglés | MEDLINE | ID: mdl-32987551

RESUMEN

Since December 2019, an outbreak of a novel coronavirus pneumonia (WHO named COVID-19) swept across China. In Shanxi Province, the cumulative confirmed cases finally reached 133 since the first confirmed case appeared on January 22, 2020, and most of which were imported cases from Hubei Province. Reasons for this ongoing surge in Shanxi province, both imported and autochthonous infected cases, are currently unclear and demand urgent investigation. In this paper, we developed a SEIQR difference-equation model of COVID-19 that took into account the transmission with discrete time imported cases, to perform assessment and risk analysis. Our findings suggest that if the lock-down date in Wuhan is earlier, the infectious cases are fewer. Moreover, we reveal the effects of city lock-down date on the final scale of cases: if the date is advanced two days, the cases may decrease one half (67, 95% CI: 66-68); if the date is delayed for two days, the cases may reach about 196 (95% CI: 193-199). Our investigation model could be potentially helpful to study the transmission of COVID-19, in other provinces of China except Hubei. Especially, the method may also be used in countries with the first confirmed case is imported.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/transmisión , Modelos Biológicos , Pandemias , Neumonía Viral/transmisión , Número Básico de Reproducción/estadística & datos numéricos , COVID-19 , China/epidemiología , Simulación por Computador , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/prevención & control , Humanos , Cadenas de Markov , Conceptos Matemáticos , Método de Montecarlo , Pandemias/prevención & control , Pandemias/estadística & datos numéricos , Neumonía Viral/epidemiología , Neumonía Viral/prevención & control , Cuarentena/estadística & datos numéricos , SARS-CoV-2 , Factores de Tiempo , Viaje/estadística & datos numéricos
15.
Phytomedicine ; 78: 153305, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32871523

RESUMEN

BACKGROUND: Safflower yellow (SY) is the main active ingredient of safflower, with various pharmacological effects such as anticoagulating, antioxidant, and anti-arthritis effects. PURPOSE: To investigate the anti-inflammatory and chondrocyte protecting role of SY, which subsequently leads to the inhibition of cartilage degradation. METHODS: Rat chondrocytes were stimulated with tumor necrosis factor α (TNF-α) with or without SY treatment. Following this, CCK-8 assay was performed to detect cytotoxicity. RT-qPCR, Western blotting, and immunofluorescence staining were used to detect the gene/protein expression of typical cartilage matrix genes and related inflammatory markers. Subsequently, EdU assay was used to evaluate cell proliferation. RNA sequencing, online target prediction, and molecular docking were performed to determine the possible molecular targets and pathways. RESULTS: The results showed that SY restored the TNF-α-induced up-regulation of IL-1ß, PTGS2, and MMP-13 and down-regulation of COL2A1 and ACAN. Furthermore, it recovered cell proliferation by suppressing TNF-α. Gene expression profiles identified 717 differentially expressed genes (DEGs) in the cells cultured with or without SY under TNF-α stimulation. After pathway enrichment, PI3K-Akt, TNF, Cytokine-cytokine receptor interaction, NF-κB, NOD-like receptor, and Chemokine signaling pathways were notably selected to highlight NFKBIA, CCL5, CCL2, IL6, and TNF as potential targets in osteoarthritis (OA). SY inhibited TNF-α-induced activation of NF-κB and endoplasmic reticulum (ER) stress by promoting AMPK phosphorylation along with SIRT1 expression. Further, SY reduced MMP-13 expression and targeted COX-2 for decreasing PGE2 release. In addition, anterior cruciate ligament transection-induced OA was ameliorated by local administration of SY. CONCLUSION: These results demonstrate that SY protects chondrocytes and inhibits inflammation by regulating the NF-κB/SIRT1/AMPK pathways and ER stress, thus preventing cartilage degeneration in OA.


Asunto(s)
Chalcona/análogos & derivados , Condrocitos/efectos de los fármacos , Dinoprostona/metabolismo , Osteoartritis/tratamiento farmacológico , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Chalcona/química , Chalcona/farmacología , Condrocitos/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Metaloproteinasa 13 de la Matriz/genética , Simulación del Acoplamiento Molecular , FN-kappa B/metabolismo , Osteoartritis/metabolismo , Osteoartritis/patología , Fosfatidilinositol 3-Quinasas/metabolismo , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Sirtuina 1/metabolismo
16.
Biomed Pharmacother ; 130: 110568, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32745911

RESUMEN

Inflammation and poor viability of chondrocytes result in the degradation of cartilage as osteoarthritis (OA) progresses. The purpose of the present study was to investigate whether ursolic acid (UA) can protect chondrocytes and alleviate OA. Following stimulation with tumor necrosis factor-α (TNF-α), 5 µM UA displayed no cytotoxicity and reversed the up-regulation of the inflammatory factors MMP13, IL-1ß, IL-6 and PTGS2, and down-regulation of the cartilaginous genes/proteins type II collagen and Aggrecan. RNA sequencing identified 533 common deferentially expressed genes (DEGs) of which TNF, PI3K-AKT, NOD-like receptor, cytokine receptor interaction and NF-κB pathways were of potential importance. Further notable DEGs in the most-highly expressed 10 pathways contributed to maintenance of cartilaginous ECM homeostasis and were involved in an inflammatory response. The expression of these most-enriched DEGs was reversed by UA following stimulation with TNF-α. Additional investigation demonstrated that treatment with UA inhibited TNF-α-induced nuclear translocation of p65 and phosphorylation of IκBα and AKT, and reversed TNF-α-induced up-regulation of P20, ACS and NLRP3. Furthermore, rat anterior cruciate ligament transection (ACLT) induced-OA was ameliorated by treatment with UA. In conclusion, these results suggest that UA activates chondrocytes through the NF-κB/NLRP3 inflammasome pathway, thus preventing cartilage degeneration in osteoarthritis.


Asunto(s)
Antiinflamatorios/uso terapéutico , Condrocitos/efectos de los fármacos , Inflamasomas/metabolismo , FN-kappa B/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Osteoartritis/tratamiento farmacológico , Triterpenos/uso terapéutico , Animales , Antiinflamatorios/farmacología , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Condrocitos/metabolismo , Articulación de la Rodilla/efectos de los fármacos , Articulación de la Rodilla/patología , Masculino , Osteoartritis/genética , Osteoartritis/metabolismo , Osteoartritis/patología , Ratas Sprague-Dawley , Triterpenos/farmacología , Factor de Necrosis Tumoral alfa , Ácido Ursólico
17.
Cereb Cortex ; 30(9): 4771-4789, 2020 07 30.
Artículo en Inglés | MEDLINE | ID: mdl-32313935

RESUMEN

As a substrate for function, large-scale brain structural networks are crucial for fundamental and systems-level understanding of primate brains. However, it is challenging to acquire a complete primate whole-brain structural connectome using track tracing techniques. Here, we acquired a weighted brain structural network across 91 cortical regions of a whole macaque brain hemisphere with a connectivity density of 59% by predicting missing links from the CoCoMac-based binary network with a low density of 26.3%. The prediction model combines three factors, including spatial proximity, topological similarity, and cytoarchitectural similarity-to predict missing links and assign connection weights. The model was tested on a recently obtained high connectivity density yet partial-coverage experimental weighted network connecting 91 sources to 29 target regions; the model showed a prediction sensitivity of 74.1% in the predicted network. This predicted macaque hemisphere-wide weighted network has module segregation closely matching functional domains. Interestingly, the areas that act as integrators linking the segregated modules are mainly distributed in the frontoparietal network and correspond to the regions with large wiring costs in the predicted weighted network. This predicted weighted network provides a high-density structural dataset for further exploration of relationships between structure, function, and metabolism in the primate brain.


Asunto(s)
Encéfalo/anatomía & histología , Encéfalo/fisiología , Conectoma/métodos , Modelos Neurológicos , Animales , Macaca
18.
Am J Trop Med Hyg ; 101(2): 310-318, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31219001

RESUMEN

Acute diarrhea is an important public health issue. Here, we focused on the differences of enteropathogens in acute diarrhea between urban and rural areas in southeast China. Laboratory- and sentinel-based surveillance of acute diarrhea (≥ 3 loose or liquid stools/24 hours) was conducted at 16 hospitals. Fecal specimens were tested for bacterial (Aeromonas sp., Campylobacter sp., diarrheagenic Escherichia coli, Plesiomonas shigelloides, non-typhoidal Salmonella, Shigella sp., Vibrio sp., and Yersinia sp.) and viral (adenovirus, astrovirus, Norovirus, Rotavirus, and Sapovirus) pathogens. Descriptive statistics were used. Between January 1, 2010, and December 31, 2014, 4,548 outpatients with acute diarrhea were enrolled (urban, n = 3,220; rural, n = 1,328). Pathogens were identified in 2,074 (45.6%) patients. Norovirus (25.7%), Vibrio parahaemolyticus (10.2%), enteroaggregative Escherichia coli (EAEC) (8.8%), group A Rotavirus (7.0%), and enterotoxigenic Escherichia coli (ETEC) (5.6%) were the most common pathogens. Enteropathogens were less common in urban than in rural areas (42.0% versus 54.4%, P < 0.001). In urban areas, EAEC and ETEC were more common in high-income than in middle-income regions. Interventions targeting the most common enteropathogens can substantially reduce the burden of acute diarrhea in southeast China.


Asunto(s)
Diarrea/epidemiología , Pacientes Ambulatorios/estadística & datos numéricos , Población Rural/estadística & datos numéricos , Población Urbana/estadística & datos numéricos , Enfermedad Aguda , Adolescente , Adulto , Anciano , Infecciones Bacterianas/epidemiología , Niño , Preescolar , China/epidemiología , Diarrea/microbiología , Diarrea/virología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Vigilancia de Guardia , Virosis/epidemiología , Adulto Joven
19.
Chaos ; 29(3): 033116, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30927861

RESUMEN

Many systems are dynamic and time-varying in the real world. Discovering the vital nodes in temporal networks is more challenging than that in static networks. In this study, we proposed a temporal information gathering (TIG) process for temporal networks. The TIG-process, as a node's importance metric, can be used to do the node ranking. As a framework, the TIG-process can be applied to explore the impact of temporal information on the significance of the nodes. The key point of the TIG-process is that nodes' importance relies on the importance of its neighborhood. There are four variables: temporal information gathering depth n, temporal distance matrix D, initial information c, and weighting function f. We observed that the TIG-process can degenerate to classic metrics by a proper combination of these four variables. Furthermore, the fastest arrival distance based TIG-process ( fad-tig) is performed optimally in quantifying nodes' efficiency and nodes' spreading influence. Moreover, for the fad-tig process, we can find an optimal gathering depth n that makes the TIG-process perform optimally when n is small.

20.
J Infect ; 78(1): 66-74, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30017609

RESUMEN

BACKGROUND: Rotavirus is a leading cause of morbidity and mortality in young children worldwide. In China, the universal immunization of children with the rotavirus vaccine has not been introduced, and the two globally distributed vaccines (RotaTeq and Rotarix) are not licensed in the country. We aim to determine the prevalence and strain diversity of rotavirus in children with diarrhea aged ≤ five years across China. MATERIALS AND METHODS: Sentinel-based surveillance of acute diarrhea was conducted at 213 participating hospitals in China from January 1, 2009, through December 31, 2015. Group A rotavirus (RVA) was tested by using enzyme-linked immunosorbent assays, and G- and P-genotype of RVA were tested by RT-PCR methods. RESULTS: Of 33,616 children with diarrhea, 10,089 (30%) were positive for RVA; RVA-associated diarrhea was identified in 2247 (39.5%, n = 2247/5685) inpatients and 7842 (28.1%, n = 7842/27931) outpatients. Children living in low-middle-income regions suffered from the highest burden of rotavirus, with 40.7% of diarrhea cases attributed to rotavirus infection, followed by 31.3% in upper-middle-income and 11.2% in high-income regions. The majority of children (88.9%, n = 8976/10089) who tested positive for RVA were children aged ≤ 2 years. The seasonal peak of RVA was in the winter. Among all 2533 RVA strains genotyped, five strain combinations, G9P[8], G3P[8], G1P[8], G2P[4] and G3P[4], contributed to 71.3% (1807/2533) of the RVA-associated diarrhea cases. The predominant strain of RVA has rapidly evolved from G3P[8] and G1P[8] to G9P[8] in the recent years, with the proportion of G9P[8] having increased remarkably from 3.4% in 2009 to 60.9% in 2015. CONCLUSIONS: The burden of diarrhea attributed to rotavirus is high in China, highlighting the potential value of vaccination. The rapid shift of RVA strains highlights the importance of conducting rotavirus surveillance to ensure that currently marketed vaccines provide protective efficacy against the circulating strains.


Asunto(s)
Diarrea/epidemiología , Diarrea/virología , Infecciones por Rotavirus/epidemiología , Rotavirus/genética , Enfermedad Aguda , Preescolar , China/epidemiología , Heces/virología , Femenino , Variación Genética , Genotipo , Humanos , Lactante , Recién Nacido , Masculino , Filogenia , Prevalencia , Rotavirus/clasificación , Vigilancia de Guardia
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