Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 250
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Cell ; 160(4): 745-758, 2015 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-25662011

RESUMEN

Impaired insulin-mediated suppression of hepatic glucose production (HGP) plays a major role in the pathogenesis of type 2 diabetes (T2D), yet the molecular mechanism by which this occurs remains unknown. Using a novel in vivo metabolomics approach, we show that the major mechanism by which insulin suppresses HGP is through reductions in hepatic acetyl CoA by suppression of lipolysis in white adipose tissue (WAT) leading to reductions in pyruvate carboxylase flux. This mechanism was confirmed in mice and rats with genetic ablation of insulin signaling and mice lacking adipose triglyceride lipase. Insulin's ability to suppress hepatic acetyl CoA, PC activity, and lipolysis was lost in high-fat-fed rats, a phenomenon reversible by IL-6 neutralization and inducible by IL-6 infusion. Taken together, these data identify WAT-derived hepatic acetyl CoA as the main regulator of HGP by insulin and link it to inflammation-induced hepatic insulin resistance associated with obesity and T2D.


Asunto(s)
Acetilcoenzima A/metabolismo , Resistencia a la Insulina , Hígado/metabolismo , Paniculitis/metabolismo , Tejido Adiposo Blanco/química , Adolescente , Animales , Diabetes Mellitus Tipo 2 , Dieta Alta en Grasa , Glucosa/metabolismo , Humanos , Hiperglucemia , Interleucina-6/análisis , Lipólisis , Masculino , Ratones , Obesidad/metabolismo , Ratas Sprague-Dawley
2.
Nature ; 579(7798): 279-283, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32132708

RESUMEN

Although it is well-established that reductions in the ratio of insulin to glucagon in the portal vein have a major role in the dysregulation of hepatic glucose metabolism in type-2 diabetes1-3, the mechanisms by which glucagon affects hepatic glucose production and mitochondrial oxidation are poorly understood. Here we show that glucagon stimulates hepatic gluconeogenesis by increasing the activity of hepatic adipose triglyceride lipase, intrahepatic lipolysis, hepatic acetyl-CoA content and pyruvate carboxylase flux, while also increasing mitochondrial fat oxidation-all of which are mediated by stimulation of the inositol triphosphate receptor 1 (INSP3R1). In rats and mice, chronic physiological increases in plasma glucagon concentrations increased mitochondrial oxidation of fat in the liver and reversed diet-induced hepatic steatosis and insulin resistance. However, these effects of chronic glucagon treatment-reversing hepatic steatosis and glucose intolerance-were abrogated in Insp3r1 (also known as Itpr1)-knockout mice. These results provide insights into glucagon biology and suggest that INSP3R1 may represent a target for therapies that aim to reverse nonalcoholic fatty liver disease and type-2 diabetes.


Asunto(s)
Glucagón/farmacología , Gluconeogénesis/efectos de los fármacos , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Hígado/efectos de los fármacos , Acetilcoenzima A/metabolismo , Tejido Adiposo/efectos de los fármacos , Animales , Diabetes Mellitus Tipo 2/fisiopatología , Activación Enzimática/efectos de los fármacos , Glucagón/sangre , Receptores de Inositol 1,4,5-Trifosfato/genética , Lipasa/metabolismo , Lipólisis/efectos de los fármacos , Lipólisis/genética , Ratones Noqueados , Mitocondrias/efectos de los fármacos , Enfermedad del Hígado Graso no Alcohólico/fisiopatología , Oxidación-Reducción/efectos de los fármacos
3.
Proc Natl Acad Sci U S A ; 120(52): e2312666120, 2023 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-38127985

RESUMEN

AGPAT2 (1-acyl-sn-glycerol-3-phosphate-acyltransferase-2) converts lysophosphatidic acid (LPA) into phosphatidic acid (PA), and mutations of the AGPAT2 gene cause the most common form of congenital generalized lipodystrophy which leads to steatohepatitis. The underlying mechanism by which AGPAT2 deficiency leads to lipodystrophy and steatohepatitis has not been elucidated. We addressed this question using an antisense oligonucleotide (ASO) to knockdown expression of Agpat2 in the liver and white adipose tissue (WAT) of adult male Sprague-Dawley rats. Agpat2 ASO treatment induced lipodystrophy and inflammation in WAT and the liver, which was associated with increased LPA content in both tissues, whereas PA content was unchanged. We found that a controlled-release mitochondrial protonophore (CRMP) prevented LPA accumulation and inflammation in WAT whereas an ASO against glycerol-3-phosphate acyltransferase, mitochondrial (Gpam) prevented LPA content and inflammation in the liver in Agpat2 ASO-treated rats. In addition, we show that overnutrition, due to high sucrose feeding, resulted in increased hepatic LPA content and increased activated macrophage content which were both abrogated with Gpam ASO treatment. Taken together, these data identify LPA as a key mediator of liver and WAT inflammation and lipodystrophy due to AGPAT2 deficiency as well as liver inflammation due to overnutrition and identify LPA as a potential therapeutic target to ameliorate these conditions.


Asunto(s)
Hígado Graso , Lipodistrofia , Hipernutrición , Masculino , Ratas , Animales , Aciltransferasas/metabolismo , Glicerol , 1-Acilglicerol-3-Fosfato O-Aciltransferasa/genética , 1-Acilglicerol-3-Fosfato O-Aciltransferasa/metabolismo , Ratas Sprague-Dawley , Lipodistrofia/genética , Tejido Adiposo Blanco/metabolismo , Ácidos Fosfatidicos , Inflamación , Fosfatos
4.
Proc Natl Acad Sci U S A ; 120(4): e2217543120, 2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36669104

RESUMEN

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, in which prognosis is determined by liver fibrosis. A common variant in hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13, rs72613567-A) is associated with a reduced risk of fibrosis in NAFLD, but the underlying mechanism(s) remains unclear. We investigated the effects of this variant in the human liver and in Hsd17b13 knockdown in mice by using a state-of-the-art metabolomics approach. We demonstrate that protection against liver fibrosis conferred by the HSD17B13 rs72613567-A variant in humans and by the Hsd17b13 knockdown in mice is associated with decreased pyrimidine catabolism at the level of dihydropyrimidine dehydrogenase. Furthermore, we show that hepatic pyrimidines are depleted in two distinct mouse models of NAFLD and that inhibition of pyrimidine catabolism by gimeracil phenocopies the HSD17B13-induced protection against liver fibrosis. Our data suggest pyrimidine catabolism as a therapeutic target against the development of liver fibrosis in NAFLD.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Animales , Humanos , Ratones , Hígado/metabolismo , Cirrosis Hepática/patología , Enfermedad del Hígado Graso no Alcohólico/patología , Pirimidinas/farmacología , Pirimidinas/metabolismo
5.
Small ; 20(5): e2304739, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37726489

RESUMEN

The depletion of fossil fuel resources and its impact on the environment provide a compelling motivation for the development of sustainable energy sources to meet the increasing demand for energy. Accordingly, research and development of energy storage devices have emerged as a critical area of focus. The electrode materials are critical in the electrochemical performance of energy storage devices, such as energy storage capacity and cycle life. Cellulose nanofiber (CNF) represents an important substrate with potentials in the applications of green electrode materials due to their environmental sustainability and excellent compatibility. By utilizing the layer-by layer (LbL) process, well-defined nanoscale multilayer structure is prepared on a variety of substrates. In recent years, increasing attention has focused on electrode materials produced from LbL process on CNFs to yield electrodes with exceptional properties, such as high specific surface area, outstanding electrical conductivity, superior electrochemical activity, and exceptional mechanical stability. This review provides a comprehensive overview on the development of functional CNF via the LbL approach as electrode materials.

6.
Appl Microbiol Biotechnol ; 108(1): 4, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38170312

RESUMEN

The goal of this study was to characterize the fecal microbiota profiles of gestating sows, along with the fecal microbiota and milk fatty acid contents of lactating sows and their correlations with reproductive performance at different parities. The results showed that the microbiota of third parity gestating sows contained a greater abundance of Prevotella compared to the other two parity groups, while lactating sows exhibiting higher reproductive performance at fifth parity exhibited a greater abundance of Lactobacillus species. The lactating sows with higher reproductive performance also exhibited higher total monounsaturated fatty acid (MUFA) and higher total polyunsaturated fatty acid (PUFA) levels relative to sows with lower reproductive performance at all three analyzed parities, especially sows at fifth parity produced the lowest total saturated fatty acid (SFA) levels, and showed the highest C18:1n9c and C18:2n6c concentrations. In correlational analyses, the abundance of Oligella, Lactobacillus, and Corynebacterium was highly positively correlated with C18:1n9c, C18:2n6c, and C20:4n6. Overall, these results provide a rational basis for efforts to improve sow reproductive performance through the provision of precisely regulated nutrition. KEY POINTS: • Clear differences in the fecal microbiota were evident between sows of different parities. • Lactating sows with high reproductive performance showed distinct milk fatty acid profiles.


Asunto(s)
Microbiota , Leche , Embarazo , Femenino , Humanos , Animales , Lactancia , Reproducción , Ácidos Grasos , Dieta/veterinaria , Alimentación Animal/análisis
7.
Artículo en Inglés | MEDLINE | ID: mdl-39316526

RESUMEN

Background: Patients in intensive care units easily develop pressure injuries. Therefore, the prevention of and care for pressure injuries in intensive care units is an important focus of medical care. Objective: To compare the use of a pressure injury risk assessment module of a nursing information system with a paper management system to aid nursing management of high-risk pressure injuries in intensive care units. Design: This was a retrospective study. Setting: This study was performed in the Intensive Care Unit Department, North China Medical Health Group Xingtai General Hospital. Participants: We selected 120 patients who were treated in the intensive care unit of Xingtai General Hospital from January 2020 through December 2022 as the observation objects. Among the 120 enrolled patients, the 60 patients enrolled from January 2020 through June 2021 were allocated to the control group, and the 60 patients enrolled from July 2021 through December 2022 were allocated to the observation group. Interventions: Patients in the control group were nursed using a paper management system to assess pressure injury risk. Patients in the observation group were nursed using a pressure injury risk assessment module based on a nursing information system that was created by the North China Medical Health Group Xingtai General Hospital in accordance with the nursing requirements of patients with high-risk pressure injury. Primary Outcome Measures: The groups were compared for the risk assessment time of pressure injury, warning time of pressure injury reaction, incidence of pressure injury, comfort level, quality of life, and nursing satisfaction rate. Results: The risk assessment time of pressure injury and warning time of pressure injury reaction were shorter in the observation group than in the control group (P < .001, 95% CI: -4.633~-4.047 and P < .001, 95% CI: -10.72~-9.203). The total incidence of pressure injury was lower in the observation group than in the control group (P = .03, χ2=4.6). The comfort level scores, quality of life scores, and patient satisfaction scores were higher in the observation group than in the control group (P < .001, 95% CI: 14.99~19.51, P < .001, 95% CI: 6.050~10.23 and P < .001, 95% CI: 20.92~26.68). Conclusion: The pressure injury risk assessment module based on a nursing information system can effectively standardize the risk management of pressure injury in patients in the intensive care unit, shorten the early warning time of pressure injury reaction, reduce the incidence of pressure injury in patients, promote the quality of life of patients, and improve patient nursing satisfaction.

8.
Ecotoxicol Environ Saf ; 285: 117044, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-39317072

RESUMEN

Probiotics-induced feed fermentation can improve the composition of microbiota, leading to benefits in pig production. However, the influence of probiotics-driven feed fermentation on pollution reduction is limited. This study aimed to analyze the impact of Weissella-based feed fermentation on the chemical characteristics, changes in microbial abundance, and antibiotic resistance genes (ARGs). Moreover, the possible mechanism and the association among them was also analyzed. First, pigs reared on fermented feed exhibited improved growth performance. The fermentation group showed a significant reduction in emissions of total phosphorus (TP), total carbon (TC), organic matter (OM), copper (Cu), and zinc (Zn) levels in feces compared to the control group. The fermentation group also showed a significant decrease in the ARGs, especially for the tetX, tetW, tetQ, tetL, tetO, tet32, tet44, ermG, ermF, CfxA2, CfxA3, aph3-III, aadA, and ant9-I, compared to the control group. The primary functional microbiota, characterized by increased levels of Bifidobacterium, Megasphaera, and Mitsuokella, and decreased levels of Methanosphaera, and Ruminiclostridium, displayed both negative and positive correlations with ARGs, TC, TP, OM, Cu, and Zn. Furthermore, a significant association was observed between the alterations in microbiota and ARGs and the lactic acid concentration in the fermented feed. The molecular docking results showed a good fit between lactate dehydrogenase and three antibiotics, particularly tetracycline. In conclusion, these results offer novel targets and strategies to address environmental pollutants associated with pig farming.


Asunto(s)
Alimentación Animal , Heces , Fermentación , Weissella , Animales , Heces/microbiología , Alimentación Animal/análisis , Porcinos , Weissella/genética , Farmacorresistencia Microbiana/genética , Probióticos , Microbioma Gastrointestinal/efectos de los fármacos , Antibacterianos/farmacología , Genes Bacterianos
9.
Phytother Res ; 2024 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-39410864

RESUMEN

Hyperuricemia is a common comorbidity of hypertension and probably has a causal relationship with hypertension. Alpha-mangostin (α-MG) has been reported to have uric acid lowering effect. This study aimed to investigate the dual effects of α-MG on blood pressure (BP) and uric acid levels in angiotensin II (Ang II)-infused hypertensive mice. Male C57BL/6 mice were randomized into five groups: control, Ang II infusion (500 ng/kg/min for 2 weeks), Ang II infusion with gavage administration of α-MG 4.0 and 8.0 mg/kg and benzbromarone (25 mg/kg) respectively. BP, uric acid levels, vascular structure and function, and renin-Ang II system expressions in the aorta were assessed. Treatment with α-MG reduced BP, improved endothelial relaxation, and reversed aortic wall thickening and collagen deposition in Ang II-induced hypertensive mice. It also downregulated Ang II receptor 1 (AT1R) and angiotensin converting enzyme (ACE) expression, while upregulating ACE2, Mas receptor (MasR), and angiotensin (1-7) in the aorta. Moreover, α-MG demonstrated a significant enhancement in uric acid clearance and reduction in serum uric acid levels. Conversely, benzbromarone did not result in a decrease in BP, indicating that the hypotensive effect of α-MG may not be necessarily dependent on its urate-lowering properties. α-MG can attenuate Ang II-induced hypertension and reverse vascular remodeling, potentially by balancing the ACE/Ang II/AT1R axis and the ACE2/Ang-(1-7)/MasR axis. Our findings provide insights into α-MG as a novel anti-hypertensive drug especially in patients with hyperuricemia.

10.
Molecules ; 29(12)2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38930835

RESUMEN

Ginseng (Panax ginseng C.A. Mey) is known for its rich saponin compounds and tonic effects. To better utilize the medicinal value of ginseng, this study investigated the extraction process, components, free radical scavenging ability, and immunomodulatory activity of total saponins of ginseng fibrous roots. The response surface methodology was employed to optimize the extraction process of total saponins, and Q-Orbitrap high-resolution liquid chromatography-mass spectrometry (LC-MS) was used to identify the chemical constituents in the total saponins extract of ginseng fibrous roots (GRS). The results showed that the optimal extraction process was achieved with an ethanol concentration of 68%, a material-solvent ratio of 1:25 mL/g, and an extraction time of 20 min, yielding a total saponin content of 6.34% under these conditions. The extract contained four terpenoid compounds and four polyphenolic compounds. GRS exhibited considerable scavenging activity against DPPH and ABTS radicals, with IC50 values of 0.893 and 0.210 mg/mL, respectively. Moreover, GRS restored immune suppression in mice by increasing white blood cell, red blood cell, and neutrophil counts, and improving the lymphocyte. It also promoted immune system recovery, as evidenced by elevated serum levels of IL-2, IFN-γ, TNF-α, and IL-1ß in mice. GRS is a natural compound with promising potential for developing antioxidants and immunomodulatory foods.


Asunto(s)
Depuradores de Radicales Libres , Panax , Extractos Vegetales , Raíces de Plantas , Saponinas , Panax/química , Saponinas/farmacología , Saponinas/química , Saponinas/aislamiento & purificación , Depuradores de Radicales Libres/farmacología , Depuradores de Radicales Libres/química , Raíces de Plantas/química , Animales , Ratones , Extractos Vegetales/química , Extractos Vegetales/farmacología , Factores Inmunológicos/farmacología , Factores Inmunológicos/química , Agentes Inmunomoduladores/farmacología , Agentes Inmunomoduladores/química , Antioxidantes/farmacología , Antioxidantes/química
11.
Diabetologia ; 66(3): 567-578, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36456864

RESUMEN

AIMS/HYPOTHESIS: Athletes exhibit increased muscle insulin sensitivity, despite increased intramuscular triacylglycerol content. This phenomenon has been coined the 'athlete's paradox' and is poorly understood. Recent findings suggest that the subcellular distribution of sn-1,2-diacylglycerols (DAGs) in the plasma membrane leading to activation of novel protein kinase Cs (PKCs) is a crucial pathway to inducing insulin resistance. Here, we hypothesised that regular aerobic exercise would preserve muscle insulin sensitivity by preventing increases in plasma membrane sn-1,2-DAGs and activation of PKCε and PKCθ despite promoting increases in muscle triacylglycerol content. METHODS: C57BL/6J mice were allocated to three groups (regular chow feeding [RC]; high-fat diet feeding [HFD]; RC feeding and running wheel exercise [RC-EXE]). We used a novel LC-MS/MS/cellular fractionation method to assess DAG stereoisomers in five subcellular compartments (plasma membrane [PM], endoplasmic reticulum, mitochondria, lipid droplets and cytosol) in the skeletal muscle. RESULTS: We found that the HFD group had a greater content of sn-DAGs and ceramides in multiple subcellular compartments compared with the RC mice, which was associated with an increase in PKCε and PKCθ translocation. However, the RC-EXE mice showed, of particular note, a reduction in PM sn-1,2-DAG and ceramide content when compared with HFD mice. Consistent with the PM sn-1,2-DAG-novel PKC hypothesis, we observed an increase in phosphorylation of threonine1150 on the insulin receptor kinase (IRKT1150), and reductions in insulin-stimulated IRKY1162 phosphorylation and IRS-1-associated phosphoinositide 3-kinase activity in HFD compared with RC and RC-EXE mice, which are sites of PKCε and PKCθ action, respectively. CONCLUSIONS/INTERPRETATION: These results demonstrate that lower PKCθ/PKCε activity and sn-1,2-DAG content, especially in the PM compartment, can explain the preserved muscle insulin sensitivity in RC-EXE mice.


Asunto(s)
Resistencia a la Insulina , Ratones , Animales , Resistencia a la Insulina/fisiología , Proteína Quinasa C-theta/metabolismo , Proteína Quinasa C-epsilon/metabolismo , Cromatografía Liquida , Fosfatidilinositol 3-Quinasas/metabolismo , Ratones Endogámicos C57BL , Espectrometría de Masas en Tándem , Insulina/metabolismo , Músculo Esquelético/metabolismo , Triglicéridos/metabolismo , Ceramidas/metabolismo
12.
Cell ; 135(5): 813-24, 2008 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-19041747

RESUMEN

N-acylphosphatidylethanolamines (NAPEs) are a relatively abundant group of plasma lipids of unknown physiological significance. Here, we show that NAPEs are secreted into circulation from the small intestine in response to ingested fat and that systemic administration of the most abundant circulating NAPE, at physiologic doses, decreases food intake in rats without causing conditioned taste aversion. Furthermore, (14)C-radiolabeled NAPE enters the brain and is particularly concentrated in the hypothalamus, and intracerebroventricular infusions of nanomolar amounts of NAPE reduce food intake, collectively suggesting that its effects may be mediated through direct interactions with the central nervous system. Finally, chronic NAPE infusion results in a reduction of both food intake and body weight, suggesting that NAPE and long-acting NAPE analogs may be novel therapeutic targets for the treatment of obesity.


Asunto(s)
Regulación del Apetito , Fosfatidiletanolaminas/fisiología , Amidas , Animales , Peso Corporal , Grasas de la Dieta/metabolismo , Endocannabinoides , Etanolaminas , Hipotálamo/metabolismo , Intestino Delgado/metabolismo , Ratones , Ratones Obesos , Actividad Motora , Obesidad/metabolismo , Ácidos Palmíticos/metabolismo , Fosfatidiletanolaminas/sangre , Proteínas Proto-Oncogénicas c-fos/metabolismo , Ratas , Espectrometría de Masas en Tándem
13.
J Chem Phys ; 159(1)2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37403851

RESUMEN

Anion exchange is a facile, post-synthetic method to tune the emission wavelength of colloidal cesium lead halide (CsPbX3, X = Cl, Br, I) perovskite nanocrystals. While colloidal nanocrystals can exhibit size-dependent phase stability and chemical reactivity, the role of size in the mechanism of anion exchange in CsPbX3 nanocrystals has not been elucidated. We used single-particle fluorescence microscopy to monitor the transformation of individual CsPbBr3 nanocrystals to CsPbI3. By systematically varying the size of the nanocrystals and the concentration of substitutional iodide, we observed that smaller nanocrystals exhibit longer transition times in their fluorescence trajectories, while larger nanocrystals undergo a more abrupt transition during anion exchange. Monte Carlo simulations were used to rationalize the size-dependent reactivity, in which we varied how each exchange event affects the probability for further exchange. Greater cooperativity for simulated ion exchange leads to shorter transition times to complete the exchange. We propose that size-dependent miscibility between CsPbBr3 and CsPbI3 at the nanoscale controls the reaction kinetics. Smaller nanocrystals maintain a homogeneous composition during anion exchange. As the nanocrystal size increases, variations in the octahedral tilting patterns of the perovskite crystals lead to different structures for CsPbBr3 and CsPbI3. Thus, an iodide-rich region must first nucleate within larger CsPbBr3 nanocrystals, which is followed by rapid transformation to CsPbI3. While higher concentrations of substitutional anions can suppress this size-dependent reactivity, the inherent differences in reactivity between nanocrystals of different sizes are important to consider when scaling up this reaction for applications in solid-state lighting and biological imaging.

14.
Proc Natl Acad Sci U S A ; 117(51): 32584-32593, 2020 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-33293421

RESUMEN

Adiponectin has emerged as a potential therapy for type 2 diabetes mellitus, but the molecular mechanism by which adiponectin reverses insulin resistance remains unclear. Two weeks of globular adiponectin (gAcrp30) treatment reduced fasting plasma glucose, triglyceride (TAG), and insulin concentrations and reversed whole-body insulin resistance, which could be attributed to both improved insulin-mediated suppression of endogenous glucose production and increased insulin-stimulated glucose uptake in muscle and adipose tissues. These improvements in liver and muscle sensitivity were associated with ∼50% reductions in liver and muscle TAG and plasma membrane (PM)-associated diacylglycerol (DAG) content and occurred independent of reductions in total ceramide content. Reductions of PM DAG content in liver and skeletal muscle were associated with reduced PKCε translocation in liver and reduced PKCθ and PKCε translocation in skeletal muscle resulting in increased insulin-stimulated insulin receptor tyrosine1162 phosphorylation, IRS-1/IRS-2-associated PI3-kinase activity, and Akt-serine phosphorylation. Both gAcrp30 and full-length adiponectin (Acrp30) treatment increased eNOS/AMPK activation in muscle and muscle fatty acid oxidation. gAcrp30 and Acrp30 infusions also increased TAG uptake in epididymal white adipose tissue (eWAT), which could be attributed to increased lipoprotein lipase (LPL) activity. These data suggest that adiponectin and adiponectin-related molecules reverse lipid-induced liver and muscle insulin resistance by reducing ectopic lipid storage in these organs, resulting in decreased plasma membrane sn-1,2-DAG-induced nPKC activity and increased insulin signaling. Adiponectin mediates these effects by both promoting the storage of TAG in eWAT likely through stimulation of LPL as well as by stimulation of AMPK in muscle resulting in increased muscle fat oxidation.


Asunto(s)
Adiponectina/farmacología , Dieta Alta en Grasa/efectos adversos , Resistencia a la Insulina/fisiología , Proteínas Quinasas Activadas por AMP/metabolismo , Adiponectina/genética , Adiponectina/metabolismo , Tejido Adiposo Blanco/efectos de los fármacos , Tejido Adiposo Blanco/metabolismo , Animales , Diglicéridos/metabolismo , Insulina/metabolismo , Metabolismo de los Lípidos , Lipoproteína Lipasa/metabolismo , Hígado/metabolismo , Masculino , Ratones Endogámicos C57BL , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Proteína Quinasa C/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacología
15.
Proc Natl Acad Sci U S A ; 117(14): 8166-8176, 2020 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-32188779

RESUMEN

Multiple insulin-regulated enzymes participate in hepatic glycogen synthesis, and the rate-controlling step responsible for insulin stimulation of glycogen synthesis is unknown. We demonstrate that glucokinase (GCK)-mediated glucose phosphorylation is the rate-controlling step in insulin-stimulated hepatic glycogen synthesis in vivo, by use of the somatostatin pancreatic clamp technique using [13C6]glucose with metabolic control analysis (MCA) in three rat models: 1) regular chow (RC)-fed male rats (control), 2) high fat diet (HFD)-fed rats, and 3) RC-fed rats with portal vein glucose delivery at a glucose infusion rate matched to the control. During hyperinsulinemia, hyperglycemia dose-dependently increased hepatic glycogen synthesis. At similar levels of hyperinsulinemia and hyperglycemia, HFD-fed rats exhibited a decrease and portal delivery rats exhibited an increase in hepatic glycogen synthesis via the direct pathway compared with controls. However, the strong correlation between liver glucose-6-phosphate concentration and net hepatic glycogen synthetic rate was nearly identical in these three groups, suggesting that the main difference between models is the activation of GCK. MCA yielded a high control coefficient for GCK in all three groups. We confirmed these findings in studies of hepatic GCK knockdown using an antisense oligonucleotide. Reduced liver glycogen synthesis in lipid-induced hepatic insulin resistance and increased glycogen synthesis during portal glucose infusion were explained by concordant changes in translocation of GCK. Taken together, these data indicate that the rate of insulin-stimulated hepatic glycogen synthesis is controlled chiefly through GCK translocation.


Asunto(s)
Hígado Graso/patología , Glucoquinasa/metabolismo , Glucosa/metabolismo , Glucógeno Hepático/biosíntesis , Hígado/metabolismo , Animales , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Hígado Graso/etiología , Técnicas de Silenciamiento del Gen , Glucoquinasa/genética , Glucosa/administración & dosificación , Glucosa-6-Fosfato/análisis , Glucosa-6-Fosfato/metabolismo , Humanos , Hiperglucemia/etiología , Hiperglucemia/patología , Hiperinsulinismo/etiología , Hiperinsulinismo/patología , Insulina/metabolismo , Resistencia a la Insulina , Hígado/patología , Masculino , Metabolómica , Fosforilación , Ratas
16.
Proc Natl Acad Sci U S A ; 117(28): 16616-16625, 2020 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-32601203

RESUMEN

Enhanced inflammation is believed to contribute to overnutrition-induced metabolic disturbance. Nutrient flux has also been shown to be essential for immune cell activation. Here, we report an unexpected role of nutrient-sensing O-linked ß-N-acetylglucosamine (O-GlcNAc) signaling in suppressing macrophage proinflammatory activation and preventing diet-induced metabolic dysfunction. Overnutrition stimulates an increase in O-GlcNAc signaling in macrophages. O-GlcNAc signaling is down-regulated during macrophage proinflammatory activation. Suppressing O-GlcNAc signaling by O-GlcNAc transferase (OGT) knockout enhances macrophage proinflammatory polarization, promotes adipose tissue inflammation and lipolysis, increases lipid accumulation in peripheral tissues, and exacerbates tissue-specific and whole-body insulin resistance in high-fat-diet-induced obese mice. OGT inhibits macrophage proinflammatory activation by catalyzing ribosomal protein S6 kinase beta-1 (S6K1) O-GlcNAcylation and suppressing S6K1 phosphorylation and mTORC1 signaling. These findings thus identify macrophage O-GlcNAc signaling as a homeostatic mechanism maintaining whole-body metabolism under overnutrition.


Asunto(s)
Macrófagos/inmunología , N-Acetilglucosaminiltransferasas/inmunología , Obesidad/inmunología , Proteínas Quinasas S6 Ribosómicas 90-kDa/inmunología , Acetilglucosamina/inmunología , Tejido Adiposo/inmunología , Animales , Humanos , Activación de Macrófagos , Macrófagos/enzimología , Ratones , Ratones Noqueados , N-Acetilglucosaminiltransferasas/genética , Obesidad/enzimología , Obesidad/genética , Obesidad/metabolismo , Fosforilación , Proteínas Quinasas S6 Ribosómicas 90-kDa/genética , Transducción de Señal
17.
Ecotoxicol Environ Saf ; 263: 115282, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37494734

RESUMEN

Nearly all modern life depends on artificial light; however, it does cause health problems. With certain restrictions of artificial light emitting technology, the influence of the light spectrum is inevitable. The most remarkable problem is its overload in the short wavelength component. Short wavelength artificial light has a wide range of influences from ocular development to mental problems. The visual neuronal pathway, as the primary light-sensing structure, may contain the fundamental mechanism of all light-induced abnormalities. However, how the artificial light spectrum shapes the visual neuronal pathway during development in mammals is poorly understood. We placed C57BL/6 mice in three different spectrum environments (full-spectrum white light: 400-750 nm; violet light: 400 ± 20 nm; green light: 510 ± 20 nm) beginning at eye opening, with a fixed light time of 7:00-19:00. During development, we assessed the ocular axial dimension, visual function and retinal neurons. After two weeks under short wavelength conditions, the ocular axial length (AL), anterior chamber depth (ACD) and length of lens thickness, real vitreous chamber depth and retinal thickness (LLVR) were shorter, visual acuity (VA) decreased, and retinal electrical activity was impaired. The density of S-cones in the dorsal and ventral retinas both decreased after one week under short wavelength conditions. In the ventral retina, it increased after three weeks. Retinal ganglion cell (RGC) density and axon thickness were not influenced; however, the axonal terminals in the lateral geniculate nucleus (LGN) were less clustered and sparse. Amacrine cells (ACs) were significantly more activated. Green light has few effects. The KEGG and GO enrichment analyses showed that many genes related to neural circuitry, synaptic formation and neurotransmitter function were differentially expressed in the short wavelength light group. In conclusion, exposure to short wavelength artificial light in the early stage of vision-dependent development in mice delayed the development of the visual pathway. The axon terminus structure and neurotransmitter function may be the major suffering.


Asunto(s)
Retina , Células Fotorreceptoras Retinianas Conos , Animales , Ratones , Ratones Endogámicos C57BL , Retina/metabolismo , Células Fotorreceptoras Retinianas Conos/fisiología , Células Ganglionares de la Retina/fisiología , Vías Nerviosas , Mamíferos
18.
Nano Lett ; 22(12): 4694-4701, 2022 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-35674669

RESUMEN

Semiconductor nanocrystals are promising candidates for generating chemical feedstocks through photocatalysis. Understanding the role of ligands used to prepare colloidal nanocrystals in catalysis is challenging due to the complexity and heterogeneity of nanocrystal surfaces. We use in situ single-molecule fluorescence imaging to map the spatial distribution of active regions along individual tungsten oxide nanowires before and after functionalizing them with ascorbic acid. Rather than blocking active sites, we observed a significant enhancement in activity for photocatalytic water oxidation after treatment with ascorbic acid. While the initial nanowires contain inactive regions dispersed along their length, the functionalized nanowires show high uniformity in their photocatalytic activity. Spatial colocalization of the active regions with their surface chemical properties shows that oxidation of ascorbic acid during photocatalysis generates new oxygen vacancies along the nanowire surface. We demonstrate that controlling surface-ligand redox chemistry during photocatalysis can enhance the active site concentration on nanocrystal catalysts.


Asunto(s)
Nanocables , Ácido Ascórbico , Catálisis , Ligandos , Nanocables/química , Oxidación-Reducción , Óxidos , Tungsteno
19.
Int J Mol Sci ; 24(4)2023 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-36834680

RESUMEN

Hepatocellular carcinoma (HCC) is one of the most lethal human cancers. Hepatitis B virus (HBV) infection accounts for nearly 50% of HCC cases. Recent studies indicate that HBV infection induces resistance to sorafenib, the first-line systemic treatment for advanced HCC for more than a decade, from 2007 to 2020. Our previous research shows that variant 1 (tv1) of proliferating cell nuclear antigen clamp-associated factor (PCLAF), overexpressed in HCC, protects against doxorubicin-induced apoptosis. However, there are no reports on the relevance of PCLAF in sorafenib resistance in HBV-related HCC. In this article, we found that PCLAF levels were higher in HBV-related HCC than in non-virus-related HCC using bioinformatics analysis. Immunohistochemistry (IHC) staining of clinical samples and the splicing reporter minigene assay using HCC cells revealed that PCLAF tv1 was elevated by HBV. Furthermore, HBV promoted the splicing of PCLAF tv1 by downregulating serine/arginine-rich splicing factor 2 (SRSF2), which hindered the inclusion of PCLAF exon 3 through a putative cis-element (116-123), "GATTCCTG". The CCK-8 assay showed that HBV decreased cell susceptibility to sorafenib through SRSF2/PCLAF tv1. HBV reduced ferroptosis by decreasing intracellular Fe2+ levels and activating GPX4 expression via the SRSF2/PCLAF tv1 axis, according to a mechanism study. Suppressed ferroptosis, on the other hand, contributed to HBV-mediated sorafenib resistance through SRSF2/PCLAF tv1. These data suggested that HBV regulated PCLAF abnormal alternative splicing by suppressing SRSF2. HBV caused sorafenib resistance by reducing ferroptosis via the SRSF2/PCLAF tv1 axis. As a result, the SRSF2/PCLAF tv1 axis may be a prospective molecular therapeutic target in HBV-related HCC, as well as a predictor of sorafenib resistance. The inhibition of the SRSF2/PCLAF tv1 axis may be crucial in the emergence of systemic chemotherapy resistance in HBV-associated HCC.


Asunto(s)
Carcinoma Hepatocelular , Ferroptosis , Hepatitis B , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/metabolismo , Línea Celular Tumoral , Virus de la Hepatitis B , Neoplasias Hepáticas/metabolismo , Factores de Empalme Serina-Arginina , Sorafenib/farmacología
20.
Molecules ; 28(22)2023 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-38005279

RESUMEN

Salix babylonica L. is a species of willow tree that is widely cultivated worldwide as an ornamental plant, but its medicinal resources have not yet been reasonably developed or utilized. Herein, we extracted and purified the total flavonoids from willow buds (PTFW) for component analysis in order to evaluate their in vitro anti-tumor and hypoglycemic activities. Through Q-Orbitrap LC-MS/MS analysis, a total of 10 flavonoid compounds were identified (including flavones, flavan-3-ols, and flavonols). The inhibitory effects of PTFW on the proliferation of cervical cancer HeLa cells, colon cancer HT-29 cells, and breast cancer MCF7 cells were evaluated using an MTT assay. Moreover, the hypoglycemic activity of PTFW was determined by investigating the inhibitory effects of PTFW on α-amylase and α-glucosidase. The results indicated that PTFW significantly suppressed the proliferation of HeLa cells, HT-29 cells, and MCF7 cells, with IC50 values of 1.432, 0.3476, and 2.297 mg/mL, respectively. PTFW, at different concentrations, had certain inhibitory effects on α-amylase and α-glucosidase, with IC50 values of 2.94 mg/mL and 1.87 mg/mL, respectively. In conclusion, PTFW at different doses exhibits anti-proliferation effects on all three types of cancer cells, particularly on HT-29 cells, and also shows significant hypoglycemic effects. Willow buds have the potential to be used in functional food and pharmaceutical industries.


Asunto(s)
Flavonoides , Salix , Humanos , Flavonoides/farmacología , Flavonoides/análisis , Hipoglucemiantes/farmacología , Hipoglucemiantes/análisis , Extractos Vegetales/farmacología , Extractos Vegetales/análisis , Cromatografía Liquida , Células HeLa , alfa-Glucosidasas , Espectrometría de Masas en Tándem , alfa-Amilasas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA