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PURPOSE: Gonadotropin-resistant ovary syndrome (GROS) is a rare endocrine disorder that causes hypergonadotropic hypogonadism, amenorrhea, and infertility. This study reports live birth in two women with GROS who underwent fertility treatment with in vitro maturation (IVM). METHODS: Both patients had primary infertility, amenorrhea (primary and secondary), typical secondary sexual characters, elevated gonadotropin levels, normal ovarian reserve, normal chromosomal characteristics, and previous nonresponsiveness gonadotropin stimulations. One patient had polymorphism of the follicle-stimulating hormone receptor, which is a predictor of poor ovarian response. Given unresponsiveness to exogenous gonadotropin stimulations, IVM with human chorionic gonadotropin priming (hCG-IVM) was performed in both patients. All transferrable embryos were vitrified. RESULTS: Both patients achieved pregnancy after their first frozen embryos transfer, and each delivered a healthy baby boy. CONCLUSIONS: These results suggest that IVM should be a first-line therapeutic option for patients with GROS.
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Gonadotropina Coriónica/metabolismo , Infertilidad Femenina/fisiopatología , Ovario/fisiología , Insuficiencia Ovárica Primaria/fisiopatología , Adulto , Transferencia de Embrión/métodos , Femenino , Fertilización In Vitro/métodos , Humanos , Técnicas de Maduración In Vitro de los Oocitos/métodos , Infertilidad Femenina/metabolismo , Nacimiento Vivo , Ovario/metabolismo , Embarazo , Embarazo Múltiple/metabolismo , Embarazo Múltiple/fisiología , Insuficiencia Ovárica Primaria/metabolismo , Receptores de HFE/metabolismoRESUMEN
Porphyromonas gingivalis is a gram-negative bacterium found in the human oral cavity and is responsible for the development of chronic periodontitis as well as neurological diseases, including Alzheimer's disease (AD). Given the significance of the roles of P. gingivalis in AD pathogenesis, it is critical to understand the underlying mechanisms of P. gingivalis-driven neuroinflammation and their contribution to neurodegeneration. Herein, we hypothesize that P. gingivalis produces secondary metabolites that may cause neurodegeneration through direct or indirect pathways mediated by microglia. To test our hypothesis, we treated human neural cells with bacterial conditioned media on our brain platforms and assessed microgliosis, astrogliosis and neurodegeneration. We found that bacteria-mediated microgliosis induced the production of nitric oxide, which causes neurodegeneration assessed with high pTau level. Our study demonstrated the elevation of detrimental protein mediators, CD86 and iNOS and the production of several pro-inflammatory markers from stimulated microglia. Through inhibition of LPS and succinate dehydrogenase in a bacterial conditioned medium, we showed a decrease in neurodegenerative microgliosis. In addition, we demonstrated the bidirectional effect of microgliosis and astrogliosis on each other exacerbating neurodegeneration. Overall, our study suggests that the mouth-brain axis may contribute to the pathogenesis of AD.
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Enfermedades Neurodegenerativas/microbiología , Porphyromonas gingivalis/patogenicidad , Enfermedad de Alzheimer/microbiología , Humanos , Microglía/metabolismoRESUMEN
Human papillomavirus (HPV) is identified as the leading cause of cervical cancer which is the second most common cancer of females in the world. This study aimed to evaluate the effects of a community-based intervention on knowledge and practice of HPV prevention among married females aged 15 to 49 in rural areas, Vietnam. This study used a quasi-experimental design with serial cross-sectional surveys at one intervention commune (Chi Linh, Hai Duong) and one control commune at other province (Thanh Thuy, Phu Tho). Number of participants in these surveys were respectively 317 and 320 in Chi Linh and 334 and 335 in Thanh Thuy at pre- and postintervention period. The time of intervention was 15 months from April 2015 to June 2016. The study used behavior models to build up a logical framework for identifying related factors of knowledge and practice among females and developing intervention strategies. A difference-in-differences analysis approach was used to evaluate the effects of this intervention program. The study identified that the intervention had a significant change of knowledge of HPV prevention among married females after the intervention (odds ratio = 3.16, 95% confidence interval: 1.3-7.66) after adjusting for other confounders but no any significant change of practice of HPV prevention (eg, condom use, numbers of sexual partner, HPV vaccination, and screening test for cervical cancer). This might be caused by a short intervention program that did not lead to changes of practice but only change of knowledge.
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Participación de la Comunidad , Educación en Salud , Conocimientos, Actitudes y Práctica en Salud , Infecciones por Papillomavirus/prevención & control , Neoplasias del Cuello Uterino/prevención & control , Adolescente , Adulto , Estudios Transversales , Femenino , Humanos , Persona de Mediana Edad , Papillomaviridae/patogenicidad , Infecciones por Papillomavirus/virología , Población Rural , Esposos , Encuestas y Cuestionarios , Neoplasias del Cuello Uterino/virología , Vietnam , Adulto JovenRESUMEN
The retinal pigment epithelium (RPE) is a monolayer of pigmented cells that requires an active metabolism to maintain outer retinal homeostasis and compensate for oxidative stress. Using 13C metabolic flux analysis in human RPE cells, we found that RPE has an exceptionally high capacity for reductive carboxylation, a metabolic pathway that has recently garnered significant interest because of its role in cancer cell survival. The capacity for reductive carboxylation in RPE exceeds that of all other cells tested, including retina, neural tissue, glial cells, and a cancer cell line. Loss of reductive carboxylation disrupts redox balance and increases RPE sensitivity to oxidative damage, suggesting that deficiencies of reductive carboxylation may contribute to RPE cell death. Supporting reductive carboxylation by supplementation with an NAD+ precursor or its substrate α-ketoglutarate or treatment with a poly(ADP ribose) polymerase inhibitor protects reductive carboxylation and RPE viability from excessive oxidative stress. The ability of these treatments to rescue RPE could be the basis for an effective strategy to treat blinding diseases caused by RPE dysfunction.
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Carbono/química , Ojo/embriología , Ácidos Cetoglutáricos/química , Degeneración Macular/metabolismo , Epitelio Pigmentado de la Retina/embriología , Epitelio Pigmentado de la Retina/metabolismo , Anciano de 80 o más Años , Animales , Diferenciación Celular , Línea Celular Tumoral , Proliferación Celular , Supervivencia Celular , Ácidos Grasos/química , Femenino , Células HeLa , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Isocitrato Deshidrogenasa/metabolismo , Degeneración Macular/patología , Ratones , NAD/química , Neoplasias/metabolismo , Neoplasias/patología , Oxidación-Reducción , Estrés Oxidativo , Oxígeno/química , Poli(ADP-Ribosa) Polimerasas/metabolismoRESUMEN
Idiopathic pulmonary fibrosis (IPF) is an irreversible progressive interstitial lung disease of unknown cause. The poorly understood pathophysiology of IPF poses substantial challenges to the development of effective anti-lung fibrotic drugs. The NLRP3 inflammasome, a key component of the innate immune system, has recently been linked to the pathogenesis of lung fibrosis. However, the specific contributions of NLRP3 inflammasomes to determination of the pro-fibrotic phenotype of lung fibroblasts, which play a central role in the production of extracellular matrix protein, remain to be investigated. Therefore, the present study was performed to elucidate the involvement of NLRP3 inflammasome signalling pathways in modulation of lung fibroblast proliferation and differentiation. We found that activation of NLRP3 inflammasomes increased in lung fibroblasts derived from individuals with pulmonary fibrosis and in normal lung fibroblasts stimulated with transforming growth factor ß and platelet-derived growth factor. Importantly, blockage of NLRP3 inflammasome signalling, either by gene silencing of NLRP3 or using pharmacological inhibitors of NLRP3, caspase-1, or IL-1 receptor, inhibited the proliferation, differentiation, and extracellular matrix protein synthesis of activated lung fibroblasts. Moreover, induction of the reactive oxygen species/thioredoxin-interacting protein axis, an upstream signalling pathway of NLRP3 inflammasomes, was essential for maintenance of the pro-fibrotic phenotype of lung fibroblasts. Interestingly, treatments with pharmacological inhibitors of NLRP3 inflammasomes prevented the progression of bleomycin-induced pulmonary fibrosis in mice. Collectively, these findings suggest that aberrant activation of NLRP3 inflammasomes is a critical event in the pathogenesis of IPF and that targeting NLRP3 inflammasomes may serve as a therapeutic strategy for IPF.
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Fibroblastos , Inflamasomas , Pulmón , Proteína con Dominio Pirina 3 de la Familia NLR , Fenotipo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Fibroblastos/metabolismo , Fibroblastos/patología , Fibroblastos/efectos de los fármacos , Inflamasomas/metabolismo , Animales , Humanos , Pulmón/patología , Pulmón/metabolismo , Pulmón/efectos de los fármacos , Pulmón/inmunología , Ratones , Fibrosis Pulmonar Idiopática/patología , Fibrosis Pulmonar Idiopática/metabolismo , Fibrosis Pulmonar Idiopática/inmunología , Ratones Endogámicos C57BL , Células Cultivadas , Proliferación Celular/efectos de los fármacos , Proliferación Celular/fisiología , Masculino , Bleomicina/toxicidad , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/fisiologíaRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing pulmonary disorder that has a poor prognosis and high mortality. Although there has been extensive effort to introduce several new anti-fibrotic agents in the past decade, IPF remains an incurable disease. Mimosa pudica L., an indigenous Vietnamese plant, has been empirically used to treat respiratory disorders. Nevertheless, the therapeutic effects of M. pudica (MP) on lung fibrosis and the mechanisms underlying those effects remain unclear. AIM OF THE STUDY: This study investigated the protective effect of a crude ethanol extract of the above-ground parts of MP against pulmonary fibrogenesis. MATERIALS AND METHODS: Inflammatory responses triggered by TNFα in structural lung cells were examined in normal human lung fibroblasts and A549 alveolar epithelial cells using Western blot analysis, reverse transcription-quantitative polymerase chain reaction assays, and immunocytochemistry. The epithelial-to-mesenchymal transition (EMT) was examined via cell morphology observations, F-actin fluorescent staining, gene and protein expression measurements, and a wound-healing assay. Anti-fibrotic assays including collagen release, differentiation, and measurements of fibrosis-related gene and protein expression levels were performed on TGFß-stimulated human lung fibroblasts and lung fibroblasts derived from mice with fibrotic lungs. Finally, in vitro anti-fibrotic activities were validated using a mouse model of bleomycin-induced pulmonary fibrosis. RESULTS: MP alleviated the inflammatory responses of A549 alveolar epithelial cells and lung fibroblasts, as revealed by inhibition of TNFα-induced chemotactic cytokine and chemokine expression, along with inactivation of the MAPK and NFκB signalling pathways. MP also partially reversed the TGFß-promoted EMT via downregulation of mesenchymal markers in A549 cells. Importantly, MP decreased the expression levels of fibrosis-related genes/proteins including collagen I, fibronectin, and αSMA; moreover, it suppressed collagen secretion and prevented myofibroblast differentiation in lung fibroblasts. These effects were mediated by FOXO3 stabilization through suppression of TGFß-induced ERK1/2 phosphorylation. MP consistently protected mice from the onset and progression of bleomycin-induced pulmonary fibrosis. CONCLUSION: This study explored the multifaceted roles of MP in counteracting the pathobiological processes of lung fibrosis. The results suggest that further evaluation of MP could yield candidate therapies for IPF.
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Transición Epitelial-Mesenquimal , Proteína Forkhead Box O3 , Sistema de Señalización de MAP Quinasas , Extractos Vegetales , Fibrosis Pulmonar , Animales , Humanos , Masculino , Ratones , Células A549 , Antifibróticos/farmacología , Bleomicina , Transición Epitelial-Mesenquimal/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Proteína Forkhead Box O3/metabolismo , Fibrosis Pulmonar Idiopática/tratamiento farmacológico , Fibrosis Pulmonar Idiopática/inducido químicamente , Fibrosis Pulmonar Idiopática/patología , Pulmón/efectos de los fármacos , Pulmón/patología , Pulmón/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones Endogámicos C57BL , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Fibrosis Pulmonar/tratamiento farmacológico , Fibrosis Pulmonar/inducido químicamenteRESUMEN
OBJECTIVE: The purpose of this study was to identify factors associated with twin pregnancy following day 3 double embryo transfer (DET). METHODS: This retrospective cohort study incorporated data from 16,972 day 3 DET cycles. The participants were women aged between 18 and 45 years who underwent in vitro fertilization with intracytoplasmic sperm injection (IVF/ICSI) at My Duc Assisted Reproduction Technique Unit (IVFMD), My Duc Hospital, located in Ho Chi Minh City, Vietnam. RESULTS: Of the 16,972 day 3 DET cycles investigated, 8,812 (51.9%) resulted in pregnancy. Of these, 6,108 cycles led to clinical pregnancy, with 1,543 (25.3% of clinical pregnancies) being twin pregnancies. Factors associated with twin pregnancy included age under 35 years (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.32 to 1.71; p<0.001) and cycles involving the transfer of at least one grade I embryo. Relative to the transfer of two grade III embryos, the risk of twin pregnancy was significantly elevated following the transfer of two grade I embryos (OR, 1.40; 95% CI, 1.16 to 1.69; p<0.001) or a combination of one grade I and one grade II embryo (OR, 1.27; 95% CI, 1.05 to 1.55; p=0.001). CONCLUSION: By analyzing a large number of IVF/ICSI cycles, we identified several predictors of twin pregnancy. These findings can assist medical professionals in tailoring treatment strategies for couples with infertility.
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The purpose of this study is to elucidate both the chemical and conformational structure of an unfractionated fucoidan extracted from brown seaweed Turbinaria ornata collected at Nha-trang bay, Vietnam. Electrospray ionization mass spectrometry (ESI-MS) was used for determining the chemical structure and small angle X-ray scattering (SAXS) provided conformational of the structure at the molecular level. The results showed that the fucoidan has a sulfate content of 25.6% and is mainly composed of fucose and galactose residues (Fuc:Gal ≈ 3:1). ESIMS analysis suggested that the fucoidan has a backbone of 3-linked α-l-Fucp residues with branches, â4)-Galp(1â at C-4 of the fucan chain. Sulfate groups are attached mostly at C-2 and sometimes at C-4 of both fucose and galactose residues. A molecular model of the fucoidan was built based on obtained chemical structure and scattering curves estimated from molecular model and observed SAXS measurement were fitted. The results indicated that fucoidan under study has a rod-like bulky chain conformation.
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Polisacáridos/química , Algas Marinas/química , Fucosa/química , Galactosa/química , Dispersión del Ángulo Pequeño , Espectrometría de Masa por Ionización de Electrospray/métodos , Sulfatos/química , Rayos XRESUMEN
Neuroinflammation has either beneficial or detrimental effects, depending on risk factors and neuron-glia interactions in neurological disorders. However, studying neuroinflammation has been challenging due to the complexity of cell-cell interactions and lack of physio-pathologically relevant neuroinflammatory models. Here, we describe our three-dimensional microfluidic multicellular human neural culture model, referred to as a 'brain-on-a-chip' (BoC). This elucidates neuron-glia interactions in a controlled manner and recapitulates pathological signatures of the major neurological disorders: dementia, brain tumor and brain edema. This platform includes a chemotaxis module offering a week-long, stable chemo-gradient compared with the few hours in other chemotaxis models. Additionally, compared with conventional brain models cultured with mixed phenotypes of microglia, our BoC can separate the disease-associated microglia out of heterogeneous population and allow selective neuro-glial engagement in three dimensions. This provides benefits of interpreting the neuro-glia interactions while revealing that the prominent activation of innate immune cells is the risk factor leading to synaptic impairment and neuronal loss, validated in our BoC models of disorders. This protocol describes how to fabricate and implement our human BoC, manipulate in real time and perform end-point analyses. It takes 2 d to set up the device and cell preparations, 1-9 weeks to develop brain models under disease conditions and 2-3 d to carry out analyses. This protocol requires at least 1 month training for researchers with basic molecular biology techniques. Taken together, our human BoCs serve as reliable and valuable platforms to investigate pathological mechanisms involving neuroinflammation and to assess therapeutic strategies modulating neuroinflammation in neurological disorders.
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Enfermedades Neurodegenerativas , Enfermedades Neuroinflamatorias , Humanos , Dispositivos Laboratorio en un Chip , Enfermedades Neuroinflamatorias/patología , Técnicas de Cultivo de Célula , Enfermedades Neurodegenerativas/patologíaRESUMEN
The evolution of preclinical in vitro cancer models has led to the emergence of human cancer-on-chip or microphysiological analysis platforms (MAPs). Although it has numerous advantages compared to other models, cancer-on-chip technology still faces several challenges such as the complexity of the tumor microenvironment and integrating multiple organs to be widely accepted in cancer research and therapeutics. In this review, we highlight the advancements in cancer-on-chip technology in recapitulating the vital biological features of various cancer types and their applications in life sciences and high-throughput drug screening. We present advances in reconstituting the tumor microenvironment and modeling cancer stages in breast, brain, and other types of cancer. We also discuss the relevance of MAPs in cancer modeling and precision medicine such as effect of flow on cancer growth and the short culture period compared to clinics. The advanced MAPs provide high-throughput platforms with integrated biosensors to monitor real-time cellular responses applied in drug development. We envision that the integrated cancer MAPs has a promising future with regard to cancer research, including cancer biology, drug discovery, and personalized medicine.
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Disciplinas de las Ciencias Biológicas , Neoplasias , Humanos , Evaluación Preclínica de Medicamentos , Ensayos Analíticos de Alto Rendimiento , Descubrimiento de Drogas , Dispositivos Laboratorio en un Chip , Microambiente TumoralRESUMEN
OBJECTIVES: Thalassemia is a genetic disorder that significantly impacts the health and well-being of individuals in Vietnam. This study aimed to assess the economic burden of Thalassemia treatment in Lam-Dong Province from the perspective of the Vietnam Social Security and to develop a model to forecast these costs. METHODS: This study analyzed the medical records of all 288 health-insured Thalassemia patients who received treatment in Lam-Dong Province from 2019-2021. The annual economic burden was calculated as the total direct medical cost of treatment per patient over one year. Bayesian Model Averaging (BMA) was utilized to forecast economic burdens. The best fit model was selected based on evaluation criteria including the R2 value, the Bayesian information criterion (BIC), and posterior model probabilities. RESULTS: The study found that the average annual economic burden of Thalassemia treatment was VND 9,947,000 (±6,854,000), equivalent to approximately USD 426.7 (±294.0), with blood transfusions being the main contributor to costs (63%). Using BMA, the best fit model to forecast economic burdens included variables including patient age, sex, and length of hospitalization, with age being the key factor with the greatest impact on the increase in economic burden. CONCLUSION: These findings provided important information for policymakers in Vietnam, as they highlighted the significant economic burden of Thalassemia treatment in the country. By developing a model to forecast these costs, policymakers can make informed decisions on how to allocate resources and support individuals with Thalassemia and their families.
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Estrés Financiero , Talasemia , Humanos , Vietnam/epidemiología , Teorema de Bayes , Seguridad Social , Talasemia/epidemiología , Talasemia/terapia , Costo de Enfermedad , Costos de la Atención en SaludRESUMEN
Recent epidemiological studies show a noticeable correlation between chronic microbial infections and neurological disorders. However, the underlying mechanisms are still not clear due to the biological complexity of multicellular and multiorgan interactions upon microbial infections. In this review, we show the infection leading to neurodegeneration mediated by multiorgan interconnections and neuroinflammation. Firstly, we highlight three inter-organ communications as possible routes from infection sites to the brain: nose-brain axis, lung-brain axis, and gut-brain axis. Next, we described the biological crosstalk between microglia and astrocytes upon pathogenic infection. Finally, our study indicates how neuroinflammation is a critical player in pathogen-mediated neurodegeneration. Taken together, we envision that antibiotics targeting neuro-pathogens could be a potential therapeutic strategy for neurodegeneration.
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Microglía , Enfermedades Neuroinflamatorias , Astrocitos , Encéfalo , Humanos , Microglía/patologíaRESUMEN
Aims: Raloxifene, a selective estrogen receptor (ER) modulator, has been reported to exert the tumor-suppressive effects in both ER-positive and ER-negative cancer cells; however, the mechanisms underlying its ER-independent anti-cancer effects are poorly understood. The NLRP3 inflammasome, a critical component of the innate immune system, has recently received growing attention owing to its multifaceted roles in various aspects of cancer development. The present study aimed at examining the involvement of NLRP3 inflammasomes in the anti-breast cancer effects of raloxifene and its underlying mechanisms. Results: Raloxifene significantly inhibited the activation of NLRP3 inflammasomes in various breast cancer cell lines. Importantly, forced expression of a gain-of-function variant of NLRP3 rescued breast cancer cells from growth arrest by raloxifene, suggesting that the suppression of NLRP3 inflammasomes activation mediates the raloxifene-induced inhibition of breast cancer growth. Mechanistically, raloxifene suppressed NLRP3 inflammasomes activation by lowering the cellular levels of reactive oxygen species (ROS) through the modulation of redox signaling mediated via aryl hydrocarbon receptor (AhR)-nuclear factor erythroid 2-related factor 2 (Nrf2)-heme oxygenase-1 (HO-1) axis or the impaired generation of mitochondrial ROS in a mitophagy-dependent manner. Further, the blockage of AhR signaling or inhibition of mitophagy abolished the tumor-suppressive effect of raloxifene in a human breast tumor xenograft model. Innovation: We elucidate a novel molecular mechanism underlying the breast tumor suppressing effect of raloxifene. Conclusion: The results observed in this study suggest that the modulation of NLRP3 inflammasomes activation is a critical event in the inhibition of breast tumor growth by raloxifene. Antioxid. Redox Signal. 37, 1030-1050.
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Neoplasias de la Mama , Inflamasomas , Humanos , Femenino , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Mitofagia , Receptores de Hidrocarburo de Aril , Especies Reactivas de Oxígeno/metabolismo , Clorhidrato de Raloxifeno/farmacología , Oxidación-Reducción , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismoRESUMEN
Balanophora laxiflora, a medicinal plant traditionally used to treat fever, pain, and inflammation in Vietnam, has been reported to possess prominent anti-inflammatory activity. This study examined the active constituents and molecular mechanisms underlying these anti-inflammatory effects using bioactivity-guided isolation in combination with cell-based assays and animal models of inflammation. Among the isolated compounds, the triterpenoid (21α)-22-hydroxyhopan-3-one (1) showed the most potent inhibitory effect on COX-2 expression in LPS-stimulated Raw 264.7 macrophages. Furthermore, 1 suppressed the expression of the inflammatory mediators iNOS, IL-1ß, INFß, and TNFα in activated Raw 264.7 macrophages and alleviated the inflammatory response in carrageenan-induced paw oedema and a cotton pellet-induced granuloma model. Mechanistically, the anti-inflammatory effects of 1 were mediated via decreasing cellular reactive oxygen species (ROS) levels by inhibiting NADPH oxidases (NOXs) and free radical scavenging activities. By downregulating ROS signalling, 1 reduced the activation of MAPK signalling pathways, leading to decreased AP-1-dependent transcription of inflammatory mediators. These findings shed light on the chemical constituents that contribute to the anti-inflammatory actions of B. laxiflora and suggest that 1 is a promising candidate for treating inflammation-related diseases.
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Fucoidans are sulfated, fucose-rich marine polysaccharides primarily found in cell walls of brown seaweeds (macroalgae). Fucoidans are known to possess beneficial bioactivities depending on their structure and sulfation degree. Here, we report the first functional characterization and the first crystal structure of a prokaryotic sulfatase, PsFucS1, belonging to sulfatase subfamily S1_13, able to release sulfate from fucoidan oligosaccharides. PsFucS1 was identified in the genome of a Pseudoalteromonas sp. isolated from sea cucumber gut. PsFucS1 (57 kDa) is Ca2+ dependent and has an unusually high optimal temperature (68 °C) and thermostability. Further, the PsFucS1 displays a unique quaternary hexameric structure comprising a tight trimeric dimer complex. The structural data imply that this hexamer formation results from an uncommon interaction of each PsFucS1 monomer that is oriented perpendicular to the common dimer interface (~ 1500 Å2) that can be found in analogous sulfatases. The uncommon interaction involves interfacing (1246 Å2) through a bundle of α-helices in the N-terminal domain to form a trimeric ring structure. The high thermostability may be related to this unusual quaternary hexameric structure formation that is suggested to represent a novel protein thermostabilization mechanism.
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Modelos Moleculares , Polisacáridos/metabolismo , Células Procariotas/enzimología , Conformación Proteica , Sulfatasas/química , Sulfatasas/metabolismo , Animales , Dominio Catalítico , Activación Enzimática , Estabilidad de Enzimas , Microbioma Gastrointestinal , Oligosacáridos/química , Oligosacáridos/metabolismo , Polisacáridos/química , Pepinos de Mar/microbiología , Sulfatasas/genéticaRESUMEN
We studied the structure of fucoidans extracted from two brown seaweed species, Sargassum crassifolium and Padina australis, and their intestinal immunomodulating activity via Peyer's patch cells of C3H/HeJ mice. ESI-MS analysis indicated that the dominant structure of both fucoidans has a backbone of α-(1â4)-linked and α-(1â3)-linked l-fucose residues and sulfate groups are attached at the C-2 and C-4 positions; branches of fucoidan from S. crassifolium are galactose residues with (1â4)- linkage and branching points are at C-4 of fucose, while fucoidan from P. australis, branches are sulfated galactose-fucose disaccharides and sulfated galactose monosaccharides attached to the main chain through (1â3)- or (1â4)- linkages. According to small angle X-ray scattering (SAXS) measurements, the two fucoidans have a branched structure. We simulated them with molecular models based on our proposed primary structure. These fucoidan samples have the ability to stimulate intestinal immunological activity via Peyer's patch cells.