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1.
Cell ; 166(4): 977-990, 2016 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-27499023

RESUMEN

Eukaryotic cells can "remember" transient encounters with a wide range of stimuli, inducing lasting states of altered responsiveness. Regulatory T (Treg) cells are a specialized lineage of suppressive CD4 T cells that act as critical negative regulators of inflammation in various biological contexts. Treg cells exposed to inflammatory conditions acquire strongly enhanced suppressive function. Using inducible genetic tracing, we analyzed the long-term stability of activation-induced transcriptional, epigenomic, and functional changes in Treg cells. We found that the inflammation-experienced Treg cell population reversed many activation-induced changes and lost its enhanced suppressive function over time. The "memory-less" potentiation of Treg suppressor function may help avoid a state of generalized immunosuppression that could otherwise result from repeated activation.


Asunto(s)
Linfocitos T Reguladores/inmunología , Animales , Diferenciación Celular , Cromatina/metabolismo , Memoria Inmunológica , Inflamación/metabolismo , Activación de Linfocitos , Ratones , Organismos Libres de Patógenos Específicos , Linfocitos T Reguladores/citología , Linfocitos T Reguladores/metabolismo , Transcripción Genética
3.
Development ; 149(20)2022 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-35899604

RESUMEN

Directed differentiation of pluripotent stem cells (PSCs) is a powerful model system for deconstructing embryonic development. Although mice are the most advanced mammalian model system for genetic studies of embryonic development, state-of-the-art protocols for directed differentiation of mouse PSCs into defined lineages require additional steps and generates target cell types with lower purity than analogous protocols for human PSCs, limiting their application as models for mechanistic studies of development. Here, we examine the potential of mouse epiblast stem cells cultured in media containing Wnt pathway inhibitors as a starting point for directed differentiation. As a proof of concept, we focused our efforts on two specific cell/tissue types that have proven difficult to generate efficiently and reproducibly from mouse embryonic stem cells: definitive endoderm and neural organoids. We present new protocols for rapid generation of nearly pure definitive endoderm and forebrain-patterned neural organoids that model the development of prethalamic and hippocampal neurons. These differentiation models present new possibilities for combining mouse genetic tools with in vitro differentiation to characterize molecular and cellular mechanisms of embryonic development.


Asunto(s)
Endodermo , Células Madre Pluripotentes , Animales , Diferenciación Celular/fisiología , Endodermo/metabolismo , Femenino , Estratos Germinativos , Humanos , Mamíferos , Ratones , Organoides , Embarazo , Prosencéfalo
4.
Nature ; 571(7765): 408-412, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31243370

RESUMEN

Mutations in the transcription factor FOXA1 define a unique subset of prostate cancers but the functional consequences of these mutations and whether they confer gain or loss of function is unknown1-9. Here, by annotating the landscape of FOXA1 mutations from 3,086 human prostate cancers, we define two hotspots in the forkhead domain: Wing2 (around 50% of all mutations) and the highly conserved DNA-contact residue R219 (around 5% of all mutations). Wing2 mutations are detected in adenocarcinomas at all stages, whereas R219 mutations are enriched in metastatic tumours with neuroendocrine histology. Interrogation of the biological properties of wild-type FOXA1 and fourteen FOXA1 mutants reveals gain of function in mouse prostate organoid proliferation assays. Twelve of these mutants, as well as wild-type FOXA1, promoted an exaggerated pro-luminal differentiation program, whereas two different R219 mutants blocked luminal differentiation and activated a mesenchymal and neuroendocrine transcriptional program. Assay for transposase-accessible chromatin using sequencing (ATAC-seq) of wild-type FOXA1 and representative Wing2 and R219 mutants revealed marked, mutant-specific changes in open chromatin at thousands of genomic loci and exposed sites of FOXA1 binding and associated increases in gene expression. Of note, ATAC-seq peaks in cells expressing R219 mutants lacked the canonical core FOXA1-binding motifs (GTAAAC/T) but were enriched for a related, non-canonical motif (GTAAAG/A), which was preferentially activated by R219-mutant FOXA1 in reporter assays. Thus, FOXA1 mutations alter its pioneering function and perturb normal luminal epithelial differentiation programs, providing further support for the role of lineage plasticity in cancer progression.


Asunto(s)
Diferenciación Celular/genética , Factor Nuclear 3-alfa del Hepatocito/genética , Mutación , Fenotipo , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/patología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión , Linaje de la Célula , Cromatina/genética , Cromatina/metabolismo , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica , Factor Nuclear 3-alfa del Hepatocito/química , Humanos , Masculino , Ratones , Ratones Endogámicos NOD , Motivos de Nucleótidos , Organoides/citología , Organoides/metabolismo
5.
Sensors (Basel) ; 24(1)2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38202875

RESUMEN

This research aims to assess the functionality of the VLP-32 LiDAR sensor, which serves as the principal sensor for object recognition in autonomous vehicles. The evaluation is conducted by simulating edge conditions the sensor might encounter in a controlled darkroom setting. Parameters for environmental conditions under examination encompass measurement distances ranging from 10 to 30 m, varying rainfall intensities (0, 20, 30, 40 mm/h), and different observation angles (0°, 30°, 60°). For the material aspects, the investigation incorporates reference materials, traffic signs, and road surfaces. Employing this diverse set of conditions, the study quantitatively assesses two critical performance metrics of LiDAR: intensity and NPC (number of point clouds). The results indicate a general decline in intensity as the measurement distance, rainfall intensity, and observation angles increase. Instances were identified where the sensor failed to record intensity for materials with low reflective properties. Concerning NPC, both the effective measurement area and recorded values demonstrated a decreasing trend with enlarging measurement distance and angles of observation. However, NPC metrics remained stable despite fluctuations in rainfall intensity.

6.
Plant Physiol ; 186(3): 1734-1746, 2021 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-33909905

RESUMEN

The cytokinin (CK) phytohormones have long been known to activate cell proliferation in plants. However, how CKs regulate cell division and cell expansion remains unclear. Here, we reveal that a basic helix-loop-helix transcription factor, CYTOKININ-RESPONSIVE GROWTH REGULATOR (CKG), mediates CK-dependent regulation of cell expansion and cell cycle progression in Arabidopsis thaliana. The overexpression of CKG increased cell size in a ploidy-independent manner and promoted entry into the S phase of the cell cycle, especially at the seedling stage. Furthermore, CKG enhanced organ growth in a pleiotropic fashion, from embryogenesis to reproductive stages, particularly of cotyledons. In contrast, ckg loss-of-function mutants exhibited smaller cotyledons. CKG mainly regulates the expression of genes involved in the regulation of the cell cycle including WEE1. We propose that CKG provides a regulatory module that connects cell cycle progression and organ growth to CK responses.


Asunto(s)
Arabidopsis/crecimiento & desarrollo , Arabidopsis/genética , Ciclo Celular/genética , División Celular/genética , Proliferación Celular/genética , Citocininas/genética , Citocininas/metabolismo , Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Plantas Modificadas Genéticamente
7.
Mol Cell Proteomics ; 19(8): 1248-1262, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32404488

RESUMEN

Peptides derived from non-functional precursors play important roles in various developmental processes, but also in (a)biotic stress signaling. Our (phospho)proteome-wide analyses of C-TERMINALLY ENCODED PEPTIDE 5 (CEP5)-mediated changes revealed an impact on abiotic stress-related processes. Drought has a dramatic impact on plant growth, development and reproduction, and the plant hormone auxin plays a role in drought responses. Our genetic, physiological, biochemical, and pharmacological results demonstrated that CEP5-mediated signaling is relevant for osmotic and drought stress tolerance in Arabidopsis, and that CEP5 specifically counteracts auxin effects. Specifically, we found that CEP5 signaling stabilizes AUX/IAA transcriptional repressors, suggesting the existence of a novel peptide-dependent control mechanism that tunes auxin signaling. These observations align with the recently described role of AUX/IAAs in stress tolerance and provide a novel role for CEP5 in osmotic and drought stress tolerance.


Asunto(s)
Adaptación Fisiológica , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/fisiología , Ácidos Indolacéticos/metabolismo , Péptidos/metabolismo , Proteómica , Estrés Fisiológico , Adaptación Fisiológica/genética , Arabidopsis/genética , Transporte Biológico/genética , Sequías , Regulación de la Expresión Génica de las Plantas , Ósmosis , Fosfoproteínas/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteoma/metabolismo , Plantones/crecimiento & desarrollo , Estrés Fisiológico/genética , Transcripción Genética
8.
Sensors (Basel) ; 22(17)2022 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-36081176

RESUMEN

Inspecting the sealing integrity of lead tabs is an important means of ensuring the reliability and safety of pouch-type lithium-ion (Li-ion) batteries with a thin multi-layered aluminum (Al) laminated film. This paper presents a new air-coupled ultrasonic non-destructive testing (NDT) inspection method based on leaky Lamb wave transmission; and reception for evaluating the sealing integrity between the lead tab and the Al pouch film. The proposed method uses the critical incidence angle between the air and the layer with the fastest Lamb wave velocity to maximize the signal-to-noise ratio in the through-transmission mode. To determine the critical incidence angle, phantom experiments with two test pieces (i.e., an Al tab and an Al tab sealed with an Al pouch film) are conducted. In addition, 2D scans are performed at various incidence angles for an inhouse pouch-type Li-ion battery with a 1-mm-wide foreign material inserted as a defect. At the critical incidence angle (i.e., 22°), the proposed air-coupled ultrasonic NDT method in through-transmission mode successfully identifies the shape and location of the defect through c-scan image reconstruction. These preliminary results indicate that the proposed air-coupled ultrasonic NDT method with leaky Lamb waves can be used to inspect the sealing integrity of Li-ion pouch batteries in dry test conditions.

9.
Int J Mol Sci ; 23(19)2022 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-36232857

RESUMEN

Protoplasts are single cells isolated from tissues or organs and are considered a suitable system for cell studies in plants. Embryogenic cells are totipotent stem cells, but their regeneration ability decreases or becomes lost altogether with extension of the culture period. In this study, we isolated and cultured EC-derived protoplasts (EC-pts) from carrots and compared them with non-EC-derived protoplasts (NEC-pts) with respect to their totipotency. The protoplast isolation conditions were optimized, and the EC-pts and NEC-pts were characterized by their cell size and types. Both types of protoplasts were then embedded using the alginate layer (TAL) method, and the resulting EC-pt-TALs and NEC-pt-TALs were cultured for further regeneration. The expression of the EC-specific genes SERK1, WUS, BBM, LEC1, and DRN was analyzed to confirm whether EC identity was maintained after protoplast isolation. The protoplast isolation efficiency for EC-pts was 2.4-fold higher than for NEC-pts (3.5 × 106 protoplasts·g−1 FW). In the EC-pt group, protoplasts < 20 µm accounted for 58% of the total protoplasts, whereas in the NEC-pt group, small protoplasts accounted for only 26%. In protoplast culture, the number of protoplasts that divided was 2.6-fold higher for EC-pts than for NEC-pts (7.7 × 104 protoplasts·g−1 FW), with a high number of plants regenerated for EC-pt-TALs, whereas no plants were induced by NEC-pt-TAL. Five times more plants were regenerated from EC-pts than from ECs. Regarding the expression of EC-specific genes, WUS and SERK1 expression increased 12-fold, and LEC1 and BBM expression increased 3.6−6.4-fold in isolated protoplasts compared with ECs prior to protoplast isolation (control). These results reveal that the protoplast isolation process did not affect the embryogenic cell identity; rather, it increased the plant regeneration rate, confirming that EC-derived protoplast culture may be an efficient system for increasing the regeneration ability of old EC cultures through the elimination of old and inactivate cells. EC-derived protoplasts may also represent an efficient single-cell system for application in new breeding technologies such as genome editing.


Asunto(s)
Daucus carota , Protoplastos , Alginatos , Fitomejoramiento , Células Madre Totipotentes
10.
New Phytol ; 230(4): 1503-1516, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33570747

RESUMEN

The tight regulation of local auxin homeostasis and signalling maxima in xylem precursor cells specifies the organising activity of the vascular cambium and consequently promotes xylem differentiation and wood formation. However, the molecular mechanisms underlying the local auxin signalling maxima in the vascular cambium are largely unknown. Here, we reveal that brassinosteroid (BR)-activated WALLS ARE THIN1 (WAT1) facilitates wood formation by enhancing local auxin signalling in the vascular cambium in Solanum lycopersicum. Growth defects and low auxin signalling readouts in the BR-deficient tomato cultivar, Micro-Tom, were associated with a novel recessive allele, Slwat1-copi, created by the insertion of a retrotransposon in the last exon of the SlWAT1 locus. Molecular and genetic studies by generating the gain-of-function and loss-of-function tomato mutants revealed that SlWAT1 is a critical regulator for fine tuning local auxin homeostasis and signalling outputs in vascular cambium to facilitate secondary growth. Finally, we discovered that BR-regulated SlBZR1/2 directly activated downstream auxin responses by SlWAT1 upregulation in xylem precursor cells to facilitate xylem differentiation and subsequent wood formation. Our data suggest that the BR-SlBZR1/2-WAT1 signalling network contributes to the high level of auxin signalling in the vascular cambium for secondary growth.


Asunto(s)
Brasinoesteroides , Cámbium , Regulación de la Expresión Génica de las Plantas , Ácidos Indolacéticos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Madera/metabolismo , Xilema/metabolismo
11.
Sensors (Basel) ; 21(21)2021 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-34770600

RESUMEN

Custom inspection using X-ray imaging is a very promising application of modern pattern recognition technology. However, the lack of data or renewal of tariff items makes the application of such technology difficult. In this paper, we present a data augmentation technique based on a new image-to-image translation method to deal with these difficulties. Unlike the conventional methods that convert a semantic label image into a realistic image, the proposed method takes a texture map with a special modification as an additional input of a generative adversarial network to reproduce domain-specific characteristics, such as background clutter or sensor-specific noise patterns. The proposed method was validated by applying it to backscatter X-ray (BSX) vehicle data augmentation. The Fréchet inception distance (FID) of the result indicates the visual quality of the translated image was significantly improved from the baseline when the texture parameters were used. Additionally, in terms of data augmentation, the experimental results of classification, segmentation, and detection show that the use of the translated image data, along with the real data consistently, improved the performance of the trained models. Our findings show that detailed depiction of the texture in translated images is crucial for data augmentation. Considering the comparatively few studies that have examined custom inspections of container scale goods, such as cars, we believe that this study will facilitate research on the automation of container screening, and the security of aviation and ports.


Asunto(s)
Aprendizaje Profundo , Procesamiento de Imagen Asistido por Computador , Radiografía , Rayos X
12.
Int J Mol Sci ; 22(16)2021 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-34445398

RESUMEN

Gibberellins (GAs) are an important group of phytohormones associated with diverse growth and developmental processes, including cell elongation, seed germination, and secondary growth. Recent genomic and genetic analyses have advanced our knowledge of GA signaling pathways and related genes in model plant species. However, functional genomics analyses of GA signaling pathways in Panax ginseng, a perennial herb, have rarely been carried out, despite its well-known economical and medicinal importance. Here, we conducted functional characterization of GA receptors and investigated their physiological roles in the secondary growth of P. ginseng storage roots. We found that the physiological and genetic functions of P. ginseng gibberellin-insensitive dwarf1s (PgGID1s) have been evolutionarily conserved. Additionally, the essential domains and residues in the primary protein structure for interaction with active GAs and DELLA proteins are well-conserved. Overexpression of PgGID1s in Arabidopsis completely restored the GA deficient phenotype of the Arabidopsis gid1a gid1c (atgid1a/c) double mutant. Exogenous GA treatment greatly enhanced the secondary growth of tap roots; however, paclobutrazol (PCZ), a GA biosynthetic inhibitor, reduced root growth in P. ginseng. Transcriptome profiling of P. ginseng roots revealed that GA-induced root secondary growth is closely associated with cell wall biogenesis, the cell cycle, the jasmonic acid (JA) response, and nitrate assimilation, suggesting that a transcriptional network regulate root secondary growth in P. ginseng. These results provide novel insights into the mechanism controlling secondary root growth in P. ginseng.


Asunto(s)
Perfilación de la Expresión Génica/métodos , Giberelinas/farmacología , Panax/crecimiento & desarrollo , Receptores de Superficie Celular/genética , Evolución Molecular , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Mutación con Pérdida de Función , Panax/genética , Proteínas de Plantas/genética , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Dominios Proteicos , Receptores de Superficie Celular/química , Análisis de Secuencia de ARN , Transducción de Señal/efectos de los fármacos , Triazoles/farmacología
13.
J Arthroplasty ; 35(12): 3621-3626, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32773273

RESUMEN

BACKGROUND: This study is prospectively conducted to evaluate surgical complications of monolithic dual mobility cup total hip arthroplasty (THA) in elderly patients with fractured neck of the femur. METHODS: Ninety-seven patients (97 hips) with displaced femoral neck fracture who gave informed consent for participation were prospectively enrolled. Their mean age was 76.6 years (range, 60-95 years), and the mean bone mineral density T-score of neck of the femur was -2.8 (range, -1.2 to -5.5). All patients underwent THA with monolithic dual mobility cup, and computed tomography scans were obtained to evaluate radiographic parameters including anteversion, inclination, and loosening of acetabular cups, and periprosthetic acetabular fractures. RESULTS: With regard to cup orientation, mean inclination angle was 40.2° (range, 23.5°-63°) and mean anteversion was 32.6° (range, 7°-66.2°). The proportion of surgical outliers was 10.3% (10/97) in inclination and 35.1% (34/97) in anteversion. Early cup loosening within 2 weeks was detected in 2 hips. Periprosthetic acetabular fractures were identified in 6 hips (6/97, 6.2%). Of the 6 fractures, 5 nondisplaced fractures were healed with conservative management, but 1 fracture with displacement eventually led to cup loosening and the patient underwent revision surgery. Reoperation rate of the monolithic dual mobility cup was 4.1% (4/97). CONCLUSION: The use of the monolithic dual mobility was associated with improper cup fixation and periprosthetic acetabular fractures in the elderly with poor bone stock, although the dual mobility cup lowered the risk of early dislocation after THA.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Fracturas del Cuello Femoral , Luxación de la Cadera , Prótesis de Cadera , Acetábulo/diagnóstico por imagen , Acetábulo/cirugía , Anciano , Artroplastia de Reemplazo de Cadera/efectos adversos , Fracturas del Cuello Femoral/diagnóstico por imagen , Fracturas del Cuello Femoral/epidemiología , Fracturas del Cuello Femoral/cirugía , Luxación de la Cadera/cirugía , Prótesis de Cadera/efectos adversos , Humanos , Diseño de Prótesis , Falla de Prótesis , Reoperación , Estudios Retrospectivos
14.
Int J Mol Sci ; 21(24)2020 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-33352948

RESUMEN

Brassinosteroids (BRs) play crucial roles in the physiology and development of plants. In the model plant Arabidopsis, BR signaling is initiated at the level of membrane receptors, BRASSINOSTEROIDS INSENSITIVE 1 (BRI1) and BRI1-ASSOCIATED RECEPTOR KINASE 1 (BAK1) complex, thus activating the transcription factors (TFs) BRASSINAZOLE RESISTANT 1/BRI1-EMS-SUPPRESSOR 1 (BZR1/BES1) to coordinate BR responsive genes. BRASSINOSTEROIDS INSENSITIVE 2 (BIN2), glycogen synthase kinase 3 (GSK3) like-kinase, negatively regulates BZR1/BES1 transcriptional activity through phosphorylation-dependent cytosolic retention and shuttling. However, it is still unknown whether this mechanism is conserved in Panax ginseng C. A. Mayer, a member of the Araliaceae family, which is a shade-tolerant perennial root crop. Despite its pharmacological and agricultural importance, the role of BR signaling in the development of P. ginseng and characterization of BR signaling components are still elusive. In this study, by utilizing the Arabidopsisbri1 mutant, we found that ectopic expression of the gain of function form of PgBZR1 (Pgbzr1-1D) restores BR deficiency. In detail, ectopic expression of Pgbzr1-1D rescues dwarfism, defects of floral organ development, and hypocotyl elongation of bri1-5, implying the functional conservation of PgBZR1 in P. ginseng. Interestingly, brassinolide (BL) and BRs biosynthesis inhibitor treatment in two-year-old P. ginseng storage root interferes with and promotes, respectively, secondary growth in terms of xylem formation. Altogether, our results provide new insight into the functional conservation and potential diversification of BR signaling and response in P. ginseng.


Asunto(s)
Brasinoesteroides/farmacología , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Panax/efectos de los fármacos , Panax/fisiología , Proteínas Quinasas/genética , Proteínas Quinasas/metabolismo , Secuencia de Aminoácidos , Arabidopsis/efectos de los fármacos , Arabidopsis/fisiología , Núcleo Celular/metabolismo , Citosol/metabolismo , Proteínas de Unión al ADN/química , Resistencia a Medicamentos , Expresión Génica Ectópica , Regulación de la Expresión Génica de las Plantas , Mutación , Panax/clasificación , Fenotipo , Filogenia , Plantas Modificadas Genéticamente , Proteínas Quinasas/química , Transducción de Señal/efectos de los fármacos , Factores de Transcripción/metabolismo
15.
Molecules ; 25(23)2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-33271996

RESUMEN

We used ultraperformance liquid chromatography coupled with a photodiode-array detector and electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-PDA/ESI-Q-TOF/MS) to rapidly and accurately quantify 17 phenolic compounds. Then, we applied this method to the seed and leaf extracts of two Amaranthus species to identify and quantify phenolic compounds other than the 17 compounds mentioned above. Compounds were eluted within 30 min on a C18 column using a mobile phase (water and acetonitrile) containing 0.1% formic acid, and the specific wavelength and ion information of the compounds obtained by PDA and ESI-Q-TOF/MS were confirmed. The proposed method showed good linearity (r2 > 0.990). Limits of detection and quantification were less than 0.1 and 0.1 µg/mL, respectively. Intra- and interday precision were less than 2.4% and 1.8%, respectively. Analysis of amaranth seed and leaf extracts using the established method showed that the seeds contained high amounts of 2,4-dihydroxybenzoic acid and kaempferol, and leaves contained diverse phenolic compounds. In addition, six tentatively new phenolic compounds were identified. Moreover, seeds potentially contained 2,3-dihydroxybenzaldehyde, a beneficial bioactive compound. Thus, our method was an efficient approach for the qualitative and quantitative analysis of phenolic compounds, and could be used to investigate phenolic compounds in plants.


Asunto(s)
Amaranthus/química , Cromatografía Liquida/métodos , Fenoles/análisis , Extractos Vegetales/análisis , Espectrometría de Masa por Ionización de Electrospray/instrumentación , Espectrometría de Masa por Ionización de Electrospray/métodos , Acetonitrilos/química , Fenoles/clasificación , Extractos Vegetales/química
16.
Pflugers Arch ; 471(11-12): 1407-1418, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31667577

RESUMEN

Orexin A (OXA) is a neuropeptide associated with plasma insulin and leptin levels involved in body weight and appetite regulation. However, little is known about the effect of OXA on leptin secretion in adipocytes and its physiological roles. Leptin secretion and expression were analysed in 3T3-L1 adipocytes. Plasma leptin, adiponectin and insulin levels were measured by ELISA assay. Phosphorylated signal transducer and activator of transcription 3 (pSTAT3) levels in the hypothalamus were evaluated by western blotting. OXA dose-dependently suppressed leptin secretion from 3T3-L1 adipocytes by inhibiting its gene expression while facilitating adiponectin secretion. The leptin inhibition by OXA was mediated via orexin receptors (OXR1 and OXR2). In addition to the pathway via extracellular signal-regulated kinases, OXA triggered adenylyl cyclase-induced cAMP elevation, which results in protein kinase A-mediated activation of cAMP response element-binding proteins (CREB). Accordingly, CREB inhibition restored the OXA-induced downregulation of leptin gene expression and secretion. Exogenous OXA for 4 weeks decreased fasting plasma leptin levels and increased hypothalamic pSTAT3 levels in high-fat diet-fed mice, regardless of increase in body weight and food intake. These results suggest that high dose of OXA directly inhibits leptin mRNA expression and thus secretion in adipocytes, which may be a peripheral mechanism of OXA for its role in appetite drive during fasting. It may be also critical for lowering basal plasma leptin levels and thus maintaining postprandial hypothalamic leptin sensitivity.


Asunto(s)
Adipocitos/efectos de los fármacos , Adipocitos/metabolismo , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Leptina/sangre , Leptina/metabolismo , Orexinas/farmacología , Células 3T3-L1 , Animales , Apetito/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Línea Celular , Dieta Alta en Grasa , Masculino , Ratones , Ratones Endogámicos C57BL , Neuropéptidos/metabolismo , Receptores de Orexina/metabolismo
17.
Pflugers Arch ; 471(6): 829-843, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30617744

RESUMEN

Hydrogen peroxide (H2O2) produced endogenously can cause mitochondrial dysfunction and metabolic complications in various cell types by inducing oxidative stress. In the liver, oxidative and endoplasmic reticulum (ER) stress affects the development of non-alcoholic fatty liver disease (NAFLD). Although a link between both stresses and fatty liver diseases has been suggested, few studies have investigated the involvement of catalase in fatty liver pathogenesis. We examined whether catalase is associated with NAFLD, using catalase knockout (CKO) mice and the catalase-deficient human hepatoma cell line HepG2. Hepatic morphology analysis revealed that the fat accumulation was more prominent in high-fat diet (HFD) CKO mice compared to that in age-matched wild-type (WT) mice, and lipid peroxidation and H2O2 release were significantly elevated in CKO mice. Transmission electron micrographs indicated that the liver mitochondria from CKO mice tended to be more severely damaged than those in WT mice. Likewise, mitochondrial DNA copy number and cellular ATP concentrations were significantly lower in CKO mice. In fatty acid-treated HepG2 cells, knockdown of catalase accelerated cellular lipid accumulation and depressed mitochondrial biogenesis, which was recovered by co-treatment with N-acetyl cysteine or melatonin. This effect of antioxidant was also true in HFD-fed CKO mice, suppressing fatty liver development and improving hepatic mitochondrial function. Expression of ER stress marker proteins and hepatic fat deposition also increased in normal-diet, aged CKO mice compared to WT mice. These findings suggest that H2O2 production may be an important event triggering NAFLD and that catalase may be an attractive therapeutic target for preventing NAFLD.


Asunto(s)
Catalasa/metabolismo , Metabolismo de los Lípidos , Hígado/metabolismo , Enfermedad del Hígado Graso no Alcohólico/enzimología , Obesidad/complicaciones , Animales , Antioxidantes , Estrés del Retículo Endoplásmico , Células Hep G2 , Humanos , Peróxido de Hidrógeno/metabolismo , Hígado/ultraestructura , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias Hepáticas/metabolismo , Enfermedad del Hígado Graso no Alcohólico/etiología , Obesidad/enzimología , Estrés Oxidativo
18.
Regul Toxicol Pharmacol ; 109: 104487, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31585136

RESUMEN

Cassia tora Linn. is an annual or perennial plant of the Fabaceae/Leguminosae family. It is used in traditional medicine for various biological activities including anti-constipation, anti-inflammatory, visual acuity, and hepato-protective activities. The present study was carried out to investigate the potential toxicity of C. tora L. seed ethanol extract (CTSEE) following a 13-week repeated oral administration to Sprague-Dawley rats. CTSEE was administered orally to male and female rats for 13 weeks at 0 (control), 500, 1000, and 2000 mg/kg/day (n = 10, for male and female rats for each dose). Additional recovery groups from the control group and high dose group were observed for a 4-week recovery period. At the end of the treatment and recovery periods, animals were sacrificed, and their organs were weighed and blood samples collected. There were no treatment-related adverse effects in clinical signs, body weight, food consumption, estrous cycle, sperm parameters, urinalysis, hematology, serum biochemistry, necropsy findings, organ weight, and histopathology at any doses tested. Under the present experimental conditions, the no-observed-adverse-effect level of the CTSEE was >2000 mg/kg/day in both genders, and no target organs were identified.


Asunto(s)
Cassia/química , Extractos Vegetales/toxicidad , Administración Oral , Animales , Etanol/química , Femenino , Masculino , Medicina Tradicional/métodos , Nivel sin Efectos Adversos Observados , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Ratas , Ratas Sprague-Dawley , Semillas/química , Pruebas de Toxicidad Subcrónica
19.
BMC Complement Altern Med ; 19(1): 2, 2019 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-30606189

RESUMEN

BACKGROUND: Saururus chinensis leaves have been used as traditional medicine in Korea for pain, intoxication, edema, and furuncle. According to previous reports, these leaves exert renoprotective, neuroprotective, and antioxidant effects by attenuating inflammatory responses. However, the beneficial effect of Saururus chinensis leaves on arthritis has not been elucidated. Thus, we evaluated the water extract of Saururus chinensis leaves (SHW) using type II collagen-induced arthritis (CIA) mice models. METHODS: Quantitative analysis of major components from SHW was performed by HPLC. Arthritis was induced by injection of type II collagen. Each group was orally administered SHW (100 mg/kg and 500 mg/kg). Methotrexate (MTX) was used as a positive control. Serum levels of interleukin-6, TNF-alpha, and type II collagen IgG in the animal models were measured using ELISA. Histological features were observed by H&E staining. RESULTS: Quantitative analysis of SHW showed the contents as 56.4 ± 0.52 mg/g of miquelianin, 7.75 ± 0.08 mg/g of quercetin 3-O-(2"-O-ß -glucopyranosyl)-α-rhamnopyranoside, and 3.17 ± 0.02 mg/g of quercitrin. Treatment with 500 mg/kg SHW decreased the serum level of Interleukin-6 (IL-6), TNF-alpha, and collagen IgG in the CIA model. Moreover, SHW treatment diminished the swelling of hind limbs and monocyte infiltration in blood vessels in CIA animal models. The results indicate that SHW could decrease CIA-induced arthritis in vivo. CONCLUSIONS: The results indicate that SHW could be used to improving arthritis by reducing inflammatory factors (IL-6 and TNF-alpha). However, further experiments are required to determine how SHW influences signal transduction in animal models.


Asunto(s)
Antioxidantes/farmacología , Artritis Experimental/metabolismo , Colágeno Tipo II/efectos adversos , Extractos Vegetales/farmacología , Saururaceae/química , Animales , Inflamación/metabolismo , Interleucina-6/sangre , Interleucina-6/metabolismo , Riñón/efectos de los fármacos , Hígado/efectos de los fármacos , Masculino , Ratones , Hojas de la Planta/química , Membrana Sinovial/efectos de los fármacos , Factor de Necrosis Tumoral alfa/sangre , Factor de Necrosis Tumoral alfa/metabolismo
20.
Pflugers Arch ; 470(12): 1721-1737, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30120555

RESUMEN

Obesity and insulin resistance are considered the main causes of nonalcoholic fatty liver disease (NAFLD), and oxidative stress accelerates the progression of NAFLD. Free fatty acids, which are elevated in the liver by obesity or insulin resistance, lead to incomplete oxidation in the mitochondria, peroxisomes, and microsomes, leading to the production of reactive oxygen species (ROS). Among the ROS generated, H2O2 is mainly produced in peroxisomes and decomposed by catalase. However, when the H2O2 concentration increases because of decreased expression or activity of catalase, it migrates to cytosol and other organelles, causing cell injury and participating in the Fenton reaction, resulting in serious oxidative stress. To date, numerous studies have been shown to inhibit the pathogenesis of NAFLD, but treatment for this disease mainly depends on weight loss and exercise. Various molecules such as vitamin E, metformin, liraglutide, and resveratrol have been proposed as therapeutic agents, but further verification of the dose setting, clinical application, and side effects is needed. Reducing oxidative stress may be a fundamental method for improving not only the progression of NAFLD but also obesity and insulin resistance. However, the relationship between NAFLD progression and antioxidants, particularly catalase, which is most commonly expressed in the liver, remains unclear. Therefore, this review summarizes the role of catalase, focusing on its potential therapeutic effects in NAFLD progression.


Asunto(s)
Catalasa/metabolismo , Hígado/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Animales , Humanos , Hígado/enzimología , Estrés Oxidativo
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