RESUMEN
Although the gut microbiota can influence central nervous system (CNS) autoimmune diseases, the contribution of the intestinal epithelium to CNS autoimmunity is less clear. Here, we showed that intestinal epithelial dopamine D2 receptors (IEC DRD2) promoted sex-specific disease progression in an animal model of multiple sclerosis. Female mice lacking Drd2 selectively in intestinal epithelial cells showed a blunted inflammatory response in the CNS and reduced disease progression. In contrast, overexpression or activation of IEC DRD2 by phenylethylamine administration exacerbated disease severity. This was accompanied by altered lysozyme expression and gut microbiota composition, including reduced abundance of Lactobacillus species. Furthermore, treatment with N2-acetyl-L-lysine, a metabolite derived from Lactobacillus, suppressed microglial activation and neurodegeneration. Taken together, our study indicates that IEC DRD2 hyperactivity impacts gut microbial abundances and increases susceptibility to CNS autoimmune diseases in a female-biased manner, opening up future avenues for sex-specific interventions of CNS autoimmune diseases.
Asunto(s)
Enfermedades Autoinmunes del Sistema Nervioso , Esclerosis Múltiple , Masculino , Femenino , Ratones , Animales , Esclerosis Múltiple/metabolismo , Modelos Animales de Enfermedad , Transducción de Señal , Progresión de la Enfermedad , Receptores DopaminérgicosRESUMEN
Congenital adrenal hyperplasia (CAH) is a rare X-linked recessive inherited disease that is considered a major cause of steroidogenesis disorder and is associated with variants or complete deletion of the NR0B1 gene. The DAX-1 protein (encoded by NR0B1) is a vertebrate-specific orphan nuclear receptor and is also a transcriptional factor for adrenal and reproductive development. CAH usually causes adrenal insufficiency in infancy and early childhood, leading to hypogonadotropic hypogonadism in adulthood; however, few adult cases have been reported to date. In this study, we examined a Chinese family with one adult patient with CAH, and identified a putative variant of NR0B1 gene via next-generation sequencing (NGS), which was confirmed with Sanger sequencing. A novel nonsense variant (c.265C>T) was identified in the NR0B1 gene, which caused the premature termination of DAX-1 at residue 89 (p.G89*). Furthermore, mutant NR0B1 gene displayed a partial DAX-1 function, which may explain the late pathogenesis in our case. Additionally, qPCR revealed the abnormal expression of four important genes identified from ChIP-seq, which were associated with energy homeostasis and steroidogenesis, and were influenced by the DAX-1 mutant. In addition, hormone disorders can be caused by DAX-1 mutant and partially recovered by siRNA of PPARGC1A. Herein, we identified a novel nonsense variant (c.265C>T) of NR0B1 in a 24-year-old Chinese male who was suffering from CAH. This mutant DAX-1 protein was found to have disordered energy homeostasis and steroidogenesis based on in vitro studies, which was clinically consistent with the patient's phenotypic features.
Asunto(s)
Hiperplasia Suprarrenal Congénita/genética , Codón sin Sentido/genética , Receptor Nuclear Huérfano DAX-1/genética , Hormonas/genética , Insuficiencia Suprarrenal/genética , Adulto , Células Cultivadas , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Homeostasis/genética , Humanos , Hipogonadismo/genética , Masculino , Linaje , Adulto JovenRESUMEN
BACKGROUND: Melatonin is reported to be related to diabetes mellitus (DM) risk; however, the effect of melatonin on diabetic retinopathy (DR) risk remains unclear. AIM: The aim of this study was to determine the effect of melatonin on DR risk. METHODS: A hospital-based case-control study was conducted from January 2020 to June 2020. DR was assessed using the Diabetic Retinopathy preferred practice pattern (PPP)-updated 2019 criteria. The participants were divided into the DM cases without DR (NDR) group, non-proliferative DR (NPDR) group and proliferative DR (PDR) group. Plasma melatonin concentration was detected with the enzyme-linked immunosorbent assay kit. The relationship between plasma melatonin concentration and DR risk as well as severity was assessed. RESULTS: It was found that plasma melatonin was 72.83 ± 16.25, 60.38 ± 13.43, 44.48 ± 10.30 and 44.69 ± 8.95 pg/mL in healthy controls, NDR group, NPDR and PDR group, respectively. In addition, it was found that plasma melatonin could be used as a potential diagnostic biomarker for DR (AUC = 0.893, P < 0.001). There was a significant positive relationship between total bilirubin and melatonin content (P < 0.001) based on the correlation assay. Significant associations between total bilirubin and melatonin content were also detected in the NPDR (R 2 = 0.360, P < 0.001) and PDR (R 2 = 0.183, P < 0.001) groups. CONCLUSION: The data obtained in this study demonstrated that plasma melatonin concen-tration was decreased in DR cases and could be used as a sensitive and specific marker for the diagnosis of DR. A significant positive relationship between total bilirubin and melatonin was detected. More related studies are required to understand the role of melatonin in DR.
RESUMEN
Biochar is widely used in environmental pollution remediation, soil improvement, and biotransformation of waste. However, the leachable substances within biochar may leach out during the application process, causing detrimental effects to the reaction system and the environment. Here, the simulated solutions (distilled water, buffer salt solution, methanol, and humic acid solution) at different stages of anaerobic digestion were used as the extracting agents, and high-resolution liquid chromatography-mass spectrometry was used to study the dissolved organic composition of biochar leachates. A total of 536 effective substances were detected in the biochar leachates, of which 100 substances were highly matched to the standard substance database. The molecular weights of these 100 substances, which included phenols, aromatic acids, aromatic aldehydes and ketones, aliphatic acids, and other substances, were in the range of 109-458 and averaged 290.2. The buffer salt solution, which is commonly used for anaerobic culturing, extracted three additional aliphatic acids and four additional aromatic substances from biochar than distilled water as used in traditional research methods; the leachate of methanol contained the most diverse compounds-71 in total-including a large number of phenols and organic acids. Some humic acid organic substances are adsorbed by biochar during the leaching by humic acid, including alcohols and aliphatic acids, but humic acid still promoted the leaching of phenolic substances, while the total number of substances that were detected was reduced by 41.7%.
RESUMEN
Human corneal fibroblasts (HCFs) are implicated in corneal neovascularization (CRNV). The mechanisms underlying the inflammatory response in HCFs and the development of CRNV were explored in this study. Alkali burns were applied to the corneas of rats to establish a CRNV model. The expression of long noncoding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) and mRNA and protein levels of nuclear factor kappa B (NF-κB)- activating protein (NKAP) were examined by quantitative real-time (qRT-PCR) and Western blot methods, respectively. Lipopolysaccharide (LPS) is used to stimulate HCFs for inflammatory response. The level of inflammation factors in HCF supernatant was detected using an enzyme-linked immunosorbent assay (ELISA). Binding and interactions between NEAT1 and miRNA 1246 (miR-1246) were determined by RNA immunoprecipitation (RIP) and RNA pull-down assays in HCFs. Compared with the control group (n = 6), NEAT1 was upregulated in the corneas of the CRNV rat model (n = 6). The expression of NEAT1 in HCFs was upregulated by LPS. Downregulation of NEAT1 suppressed the secretion of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). NEAT1 could bind and interact with miR-1246. LPS regulated the expression of NKAP and NF-κB signaling via the NEAT1/miR-1246 pathway. Downregulation of NEAT1 in vivo inhibited CRNV progression in the CRNV rat model. The lncRNA NEAT1 induced secretion of inflammatory factors, mediated by NF-κB, by targeting miR-1246, thereby promoting CRNV progression.
Asunto(s)
Neovascularización de la Córnea/metabolismo , Inflamación/metabolismo , ARN Largo no Codificante/metabolismo , Animales , Western Blotting , Neovascularización de la Córnea/genética , Ensayo de Inmunoadsorción Enzimática , Inmunoprecipitación , Inflamación/genética , Masculino , ARN Largo no Codificante/genética , Ratas , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Acylation-stimulating protein (ASP), produced through activation of the alternative complement immune system, modulates lipid metabolism. Using a trans-well co-culture cell model, the mitigating role of α7-nicotinic acetylcholine receptor (α7nAChR)-mediated cholinergic pathway on ASP resistance was evaluated. ASP signaling in adipocytes via its receptor C5L2 and signaling intermediates Gαq, Gß, phosphorylated protein kinase C-α, and protein kinase C-ζ were markedly suppressed in the presence of TNFα or medium from palmitate-treated RAW264.7 macrophages, indicating ASP resistance. There was no direct effect of α7nAChR activation in 3T3-L1 cell culture. However, α7nAChR activation almost completely reversed the ASP resistance in adipocytes co-cultured with palmitate-treated RAW264.7 macrophages. Further, α7nAChR activation could suppress the production of pro-inflammatory molecules TNFα and interleukin-6 produced from palmitate-treated co-cultured macrophages. These results suggest that macrophages play a significant role in the pathogenesis of ASP resistance and α7nAChR activation secondarily improves adipose ASP resistance through suppression of inflammation in macrophages. Impact statement 1. Adipocyte-macrophage interaction in acylation-stimulating protein (ASP) resistance 2. Lipotoxicity induced inflammatory response in ASP resistance 3. A vicious circle between lipotoxicity and inflammatory response in ASP resistance 4. Cholinergic modulation of inflammatory response in adipocyte and macrophage.
Asunto(s)
Adipocitos/fisiología , Colinérgicos/metabolismo , Complemento C3a/metabolismo , Activación de Macrófagos/efectos de los fármacos , Palmitatos/metabolismo , Animales , Línea Celular , Técnicas de Cocultivo , Ratones , Receptor Nicotínico de Acetilcolina alfa 7/agonistasRESUMEN
A previous study has confirmed that the central melanocortin system was able to mediate skeletal muscle AMP-activated protein kinase (AMPK) activation in mice fed a high-fat diet, while activation of the AMPK signaling pathway significantly induced mitochondrial biogenesis. Our hypothesis was that melanocortin 4 receptor (MC4R) was involved in the development of skeletal muscle injury in diabetic rats. In this study, we treated diabetic rats intracerebroventricularly with MC4R agonist R027-3225 or antagonist SHU9119, respectively. Then, we measured the production of reactive oxygen species (ROS), the levels of malondialdehyde (MDA) and glutathione (GSH), the mitochondrial DNA (mtDNA) content and mitochondrial biogenesis, and the protein levels of p-AMPK, AMPK, peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α), sirtuin 1 (SIRT1), and manganese superoxide dismutase (MnSOD) in the skeletal muscle of diabetic rats. The results showed that there was significant skeletal muscle injury in the diabetic rats along with serious oxidative stress and decreased mitochondrial biogenesis. Treatment with R027-3225 reduced oxidative stress and induced mitochondrial biogenesis in skeletal muscle, and also activated the AMPK-SIRT1-PGC-1α signaling pathway. However, diabetic rats injected with MC4R antagonist SHU9119 showed an aggravated oxidative stress and mitochondrial dysfunction in skeletal muscle. In conclusion, our results revealed that MC4R activation was able to attenuate oxidative stress and mitochondrial dysfunction in skeletal muscle induced by diabetes partially through activating the AMPK-SIRT1-PGC-1α signaling pathway. J. Cell. Biochem. 118: 4072-4079, 2017. © 2017 Wiley Periodicals, Inc.
Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Mitocondrias Musculares/metabolismo , Músculo Esquelético/metabolismo , Receptor de Melanocortina Tipo 4/metabolismo , Transducción de Señal , Animales , Diabetes Mellitus Experimental/patología , Masculino , Mitocondrias Musculares/patología , Músculo Esquelético/patología , Péptidos/farmacología , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Ratas , Ratas Sprague-Dawley , Sirtuina 1/metabolismoRESUMEN
Catch-up growth in adult, is increasingly recognized as an important causative factor for the extremely prevalent insulin resistance-related diseases especially in developing countries/territories. We aimed to investigate the alteration of bile acids level, phosphorylation and sumoylation of its interacting protein, bile acid receptor/farnesoid X receptor and their downstream signaling pathway, as well as insulin sensitivity and lipid profile in catch-up growth in adult rats. Male Sprague-Dawley rats were randomly allocated into four groups for two sampling points: caloric restriction group, catch-up growth in adult refed with normal chow and their normal chow controls for four or eight weeks (N4, N8 individually).We found that total serum bile acids and farnesoid X receptor phosphorylation increased without significant changes in farnesoid X receptor sumoylation and its downstream small heterodimer partner expression at the end of caloric restriction stage, while the visceral fat decreased and insulin resistance never occurred in these animals; After refeeding, total serum bile acids, farnesoid X receptor phosphorylation and sumoylation, as well as Cyp7a1, SREBP-1c mRNA levels were higher with significant decrease in small heterodimer partner expression, which is associated fat accumulation, and drastic insulin resistance in whole body and skeletal muscle. Our findings demonstrated that the fat accumulation and insulin resistance are associated with increases of bile acids, alteration of farnesoid X receptor phosphorylation, and sumoylation and its downstream signaling pathway. These changes of bile acids, farnesoid X receptor phosphorylation and sumoylation, as well as their downstream signaling might be of importance in the etiology of fat accumulation and insulin resistance in catch-up growth in adult.
Asunto(s)
Ácidos y Sales Biliares/metabolismo , Restricción Calórica , Resistencia a la Insulina/fisiología , Grasa Intraabdominal/fisiología , Hígado/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Animales , Ácidos y Sales Biliares/sangre , Glucemia/fisiología , Colesterol 7-alfa-Hidroxilasa/genética , Masculino , Fosforilación , ARN Mensajero/genética , Ratas , Ratas Sprague-Dawley , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Sumoilación , Triglicéridos/sangreRESUMEN
Varroa destructor is a virulent ectoparasitic mite of western honeybee (Apis mellifera), and considered the greatest threat to apiculture around the world. Chemical method is widely used for the management of this mite. However, this method can easily induce the resistance of V. destructor to acaricides, toxicity of acaricides to honeybee and the residues in bee products. Therefore, many safe preventions and control techniques were developed to treat mite in recent years. Using pheromones of honeybee to control V. destructor would be a main tendency. A lot of studies indicated that Varroa mites are able to use honeybee pheromones to distinguish the development stages of the hosts, and show high selectivity for appropriate hosts at a special stage. In recent years, a lot of honey bee pheromones were reported to have effect on V. destructor, including pheromones from adult honeybee, pupa and brood. Some of them have repellent effect on V. destructor, while others have attractant effect on V. destructor. This article reviewed the progresses in pheromones categories, major chemical compositions, and their effects to V. destructor, which would suggest important avenues for further researches and applications in mite control.
Asunto(s)
Abejas , Feromonas , Varroidae , Acaricidas , Animales , PupaRESUMEN
Insufficient insulin produced by pancreatic ß-cells in the control of blood sugar is a central feature of the etiology of diabetes. Reports have shown that endoplasmic reticulum (ER) stress is fundamentally involved in ß-cell dysfunction. In this study, we hypothesized that NAD-dependent deacetylase sirtuin-3 (SIRT3), an important regulator of cell metabolism, protects pancreatic ß-cells from ER stress-mediated apoptosis. To validate our hypothesis, a rat diabetic model was established by a high-fat diet (HFD). We found that SIRT3 expression was markedly decreased in NIT1 and INS1 cells incubated with palmitate. Palmitate treatment significantly decreased ß-cell viability and insulin secretion, and promoted malondialdehyde (MDA) formation. However, SIRT3 overexpression in NIT1 and INS1 cells reversed these effects, resulting in higher insulin secretion, decreased ß-cell apoptosis, and downregulation of the expression of ER stress-associated genes. Moreover, SIRT3 overexpression also inhibited calcium influx and the hyperacetylation of glucose-regulated protein of 78 kDa (GRP78). SIRT3 knockdown effectively enhanced the upregulation of phospho-extracellular regulated protein kinases (pERK), inositol-requiring enzyme-1 (IRE1), activating transcription factor 6 (ATF6), and C/EBP homologous protein (CHOP) induced by palmitate, and promoted palmitate-induced ß-cell apoptosis and dysfunction. Taken together, our results suggest that SIRT3 is an integral regulator of ER function and that its depletion might result in the hyperacetylation of critical ER proteins that protect against islet lipotoxicity under conditions of nutrient excess.
Asunto(s)
Apoptosis , Señalización del Calcio , Estrés del Retículo Endoplásmico , Regulación Enzimológica de la Expresión Génica , Células Secretoras de Insulina/enzimología , Sirtuinas/biosíntesis , Animales , Células Secretoras de Insulina/patología , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
Inflammation is a key feature in adipose tissue, especially in association with obesity comorbidies. The novel adipokine acylation stimulating protein (ASP) is one factor implicated in the inflammatory response. The disruption of the α7 nicotine acetylcholine receptor (α7nAChR), an important component of the endogenous non-neural cholinergic defense system, may exacerbate sustained inflammatory phenotype. We examined cholinergic regulation of ASP-initiated inflammatory response in 3T3-L1 adipocytes. Our results show that preincubation of 3T3-L1 cells with α7nAChR agonist GTS-21 significantly reduces ASP-mediated chemokine MCP-1 secretion, which is regulated though nuclear factor κB (NFκB) and signal transducer and activator of transcription 3 (STAT3). Treatment of 3T3-L1 cells with GTS-21 significantly reduced NFκB activation by DNA binding and STAT3 activation by disturbing post-translational modification.
Asunto(s)
Adipocitos/metabolismo , Complemento C3a/metabolismo , FN-kappa B/metabolismo , Factor de Transcripción STAT3/metabolismo , Receptor Nicotínico de Acetilcolina alfa 7/metabolismo , Células 3T3-L1 , Animales , Quimiocina CCL2/metabolismo , Ratones , Transducción de SeñalRESUMEN
SIRT1 is known to improve insulin resistance (IR), but whether this effect is direct or not is still unclear, and this question has not been addressed in vivo in the skeletal muscle. Therefore, we sought to test if acute overexpression of SIRT1 in skeletal muscle of high-fat diet (HFD) rats in vivo would affect subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondrial complexes I-V activities and antioxidant enzymes thereby improving insulin action. In vivo electrotransfer was used to overexpress SIRT1 in the skeletal muscle of rats fed HFD for 12 weeks. Skeletal muscle insulin sensitivity and downstream effects of SIRT1 on AMPK, SIRT3, and mitochondrial biogenesis were studied. Citrate synthase (CS), complexes I-V, oxidative stress, and antioxidant levels were assessed in SS and IMF mitochondria. HFD rats showed skeletal muscle IR as well as decreased SIRT1 and SIRT3 expressions, mitochondrial DNA (mtDNA), and mitochondrial biogenesis (p < 0.05). SS and IMF mitochondria displayed lower CS, complexes I-V, and antioxidant enzyme activities (p < 0.05). By contrast, moderate (~2.5 folds) SIRT1 overexpression attenuated HFD-induced skeletal muscle IR. This improvement was associated with increased AMPK, PGC-1α, SIRT3, and mtDNA expressions as well as SS and IMF mitochondrial CS and complexes I-V activities. Importantly, SIRT1 overexpression largely restored antioxidant enzyme activities and enhanced complex I but not complexes II-V functions in individual SS and IMF mitochondria. This study suggests that SIRT1 overexpression improved IR at least partly by targeting complex I functions of SS and IMF mitochondria through the activation of SIRT1 and SIRT3.
Asunto(s)
Proteínas del Complejo de Cadena de Transporte de Electrón/metabolismo , Resistencia a la Insulina , Mitocondrias Musculares/metabolismo , Sirtuina 1/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Antioxidantes/metabolismo , Citrato (si)-Sintasa/metabolismo , ADN Mitocondrial/metabolismo , Dieta Alta en Grasa/efectos adversos , Masculino , Mitocondrias Musculares/genética , Miofibrillas/metabolismo , Estrés Oxidativo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma , Ratas Sprague-Dawley , Sarcolema/metabolismo , Sirtuina 1/genética , Sirtuina 3/genética , Sirtuina 3/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Insulin resistance is often characterized as the most critical factor contributing to the development of type 2 diabetes mellitus (T2DM). Sustained high glucose is an important extracellular environment that induces insulin resistance. Acquired insulin resistance is associated with reduced insulin-stimulated mitochondrial activity as a result of increased mitochondrial dysfunction. Silent information regulator 1 (SIRT1) is one member of the SIRT2 (Sir2)-like family of proteins involved in glucose homeostasis and insulin secretion in mammals. Although SIRT1 has a therapeutic effect on metabolic deterioration in insulin resistance, it is still not clear how SIRT1 is involved in the development of insulin resistance. Here, we demonstrate that pcDNA3.1 vector-mediated overexpression of SIRT1 attenuates insulin resistance in the high glucose-induced insulin-resistant skeleton muscle cells. These beneficial effects were associated with ameliorated mitochondrial dysfunction. Further studies have demonstrated that SIRT1 restores mitochondrial complex I activity leading to decreased oxidative stress and mitochondrial dysfunction. Furthermore, SIRT1 significantly elevated the level of another SIRT which is named SIRT3, and SIRT3 siRNA-suppressed SIRT1-induced mitochondria complex activity increments. Taken together, these results showed that SIRT1 improves insulin sensitivity via the amelioration of mitochondrial dysfunction, and this is achieved through the SIRT1-SIRT3-mitochondrial complex I pathway.
Asunto(s)
Glucosa/administración & dosificación , Resistencia a la Insulina , Mitocondrias Musculares/fisiología , Músculo Esquelético/fisiopatología , Sirtuina 1/fisiología , Animales , Secuencia de Bases , Línea Celular , Cartilla de ADN , Ratones , Músculo Esquelético/citología , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
AIM: To study the function and mechanism of bigelovin, a sesquiterpene lactone from the flower of Chinese herb Inula hupehensis, in regulating JAK2/STAT3 signaling and cancer cell growth. METHODS: HepG2 cells stably transfected with the STAT3-responsive firefly luciferase reporter plasmid (HepG2/STAT3 cells), and a panel of human cancer cell lines were used to identify active compounds. Cell viability was measured using MTT assay. Western blotting was used to detect protein expression and phosphorylation. Kinase assays were performed and the reaction between bigelovin and thiol-containing compounds was analyzed with LC-MS. RESULTS: Bigelovin (1-50 µmol/L) dose-dependently inhibited the IL-6-induced STAT3 activation in HepG2/STAT3 cells (IC50=3.37 µmol/L) and the constitutive STAT3 activation in A549 and MDA-MB-468 cells. Furthermore, bigelovin dose-dependently inhibited JAK2 phosphorylation in HeLa and MDA-MB-468 cells, as well as the enzymatic activity of JAK2 in vitro (IC50=44.24 µmol/L). Pretreatment of the cells with DTT (500 µmol/L) or GSH (500 µmol/L) eliminated the inhibitory effects of bigelovin on the IL-6-induced and the constitutive STAT3 activation. The results in LC-MS analysis suggested that bigelovin might react with cysteine residues of JAK2 leading to inactivation of JAK2. Bigelovin (5 and 20 µmol/L) had no effects on the signaling pathways of growth factors EGF, PDGF or insulin. Finally, bigelovin suppressed the cell viability and induced apoptosis in 10 different human cancer cell lines, particularly those with constitutively activated STAT3. CONCLUSION: Bigelovin potently inhibits STAT3 signaling by inactivating JAK2, and induces apoptosis of a variety of human cancer cells in vitro.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Janus Quinasa 2/metabolismo , Lactonas/farmacología , Neoplasias/tratamiento farmacológico , Factor de Transcripción STAT3/metabolismo , Sesquiterpenos/farmacología , Transducción de Señal/efectos de los fármacos , Antineoplásicos Fitogénicos/química , Línea Celular Tumoral , Células Hep G2 , Humanos , Inula/química , Lactonas/química , Neoplasias/metabolismo , Neoplasias/patología , Sesquiterpenos/químicaRESUMEN
Resveratrol (RSV), a natural compound, is known for its effects on energy homeostasis. Here we investigated the effects of RSV and possible mechanism in insulin secretion of high-fat diet rats. Rats were randomly divided into three groups as follows: NC group (animals were fed ad libitum with normal chow for 8 weeks), HF group (animals were fed ad libitum with high-fat diet for 8 weeks), and HFR group (animals were treated with high-fat diet and administered with RSV for 8 weeks). Insulin secretion ability of rats was assessed by hyperglycemic clamp. Mitochondrial biogenesis genes, mitochondrial respiratory chain activities, reactive oxidative species (ROS), and several mitochondrial antioxidant enzyme activities were evaluated in islet. We found that HF group rats clearly showed low insulin secretion and mitochondrial complex dysfunction. Expression of silent mating type information regulation 2 homolog- 1 (SIRT1) and related mitochondrial biogenesis were significantly decreased. However, RSV administration group (HFR) showed a marked potentiation of glucose-stimulated insulin secretion. This effect was associated with elevated SIRT1 protein expression and antioxidant enzyme activities, resulting in increased mitochondrial respiratory chain activities and decreased ROS level. This study suggests that RSV may increase islet mitochondrial complex activities and antioxidant function to restore insulin secretion dysfunction induced by high-fat diet.
Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Grasas de la Dieta/efectos adversos , Hiperglucemia/metabolismo , Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Mitocondrias/metabolismo , Estilbenos/farmacología , Animales , Grasas de la Dieta/farmacología , Transporte de Electrón/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Hiperglucemia/inducido químicamente , Hiperglucemia/patología , Secreción de Insulina , Islotes Pancreáticos/patología , Masculino , Mitocondrias/patología , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Resveratrol , Sirtuina 1/biosíntesisRESUMEN
Catch-up growth in adult (CUGA) is increasingly proposed as an important causative factor for the widespread insulin resistance (IR)-related diseases especially in developing countries/territories. We aimed to investigate the effects of CUGA to insulin sensitivity, lipid profile and stress in rats, as well as the probable relationship among them. Male Sprague-Dawley rats were randomly divided into six groups for two sampling points: caloric restriction group (R4) and normal chow controls for four weeks (NC4); CUGA re-fed with normal chow (RN4), CUGA re-fed with high-fat diet (RH4), normal chow controls (NC8) and high-fat diet controls (HF8) for eight weeks. Visceral fat accumulation (visceral adipose tissue [VAT] percentage), systemic (plasma corticosterone) and local (HSD11B1 mRNA expression in skeletal muscle [SkM] and VAT) stress, whole-body and peripheral insulin sensitivity were determined in this study. After four weeks of caloric restriction, R4 rats showed increases in systemic and local stress, decreases in visceral fat accumulation and no IR (whole-body or peripheral). Yet, after re-feeding, sustained systemic and local stress, remarkable visceral fat accumulation and IR (whole-body and peripheral) were found in RN4 compared with NC8, in RH4 compared with NC8 and HF8. Our findings demonstrated that CUGA rats were characterized by significant IR, visceral fat accumulation and stress. These changes were more severe in CUGA re-fed with high-fat diet. The interaction of sustained caloric restriction-induced stress and re-feeding might be of utmost importance in the etiology of visceral fat accumulation and IR in CUGA.
Asunto(s)
Dieta/métodos , Resistencia a la Insulina , Grasa Intraabdominal , Inanición , Estrés Fisiológico , Animales , Grasa Intraabdominal/metabolismo , Masculino , Músculo Esquelético/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
BACKGROUND: Degummed silk fibroin from Bombyx mori (silkworm) has potential carrier capabilities for drug delivery in humans; however, the processing methods have yet to be comparatively analyzed to determine the differential effects on the silk protein properties, including crystalline structure and activity. METHODS: In this study, we treated degummed silk with four kinds of calcium-alcohol solutions, and performed secondary structure measurements and enzyme activity test to distinguish the differences between the regenerated fibroins and degummed silk fibroin. RESULTS: Gel electrophoresis analysis revealed that Ca(NO3)2-methanol, Ca(NO3)2-ethanol, or CaCl2-methanol treatments produced more lower molecular weights of silk fibroin than CaCl2-ethanol. X-ray diffraction and Fourier-transform infrared spectroscopy showed that CaCl2-ethanol produced a crystalline structure with more silk I (α-form, type II ß-turn), while the other treatments produced more silk II (ß-form, anti-parallel ß-pleated sheet). Solid-State 13C cross polarization and magic angle spinning-nuclear magnetic resonance measurements suggested that regenerated fibroins from CaCl2-ethanol were nearly identical to degummed silk fibroin, while the other treatments produced fibroins with significantly different chemical shifts. Finally, enzyme activity test indicated that silk fibroins from CaCl2-ethanol had higher activity when linked to a known chemotherapeutic drug, L-asparaginase, than the fibroins from other treatments. CONCLUSIONS: Collectively, these results suggest that the CaCl2-ethanol processing method produces silk fibroin with biomaterial properties that are appropriate for drug delivery.
Asunto(s)
Materiales Biocompatibles , Sistemas de Liberación de Medicamentos , Fibroínas/química , Seda/química , Electroforesis en Gel de Poliacrilamida , Espectroscopía de Resonancia Magnética , Microscopía Electrónica de Rastreo , Peso Molecular , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos XRESUMEN
AIM: To investigate the protective effects of arctigenin (ATG), a phenylpropanoid dibenzylbutyrolactone lignan from Arctium lappa L (Compositae), against ER stress in vitro and the underlying mechanisms. METHODS: A cell-based screening assay for ER stress regulators was established. Cell viability was measured using MTT assay. PCR and Western blotting were used to analyze gene and protein expression. Silencing of the CaMKKß, LKB1, and AMPKα1 genes was achieved by RNA interference (RNAi). An ATP bioluminescent assay kit was employed to measure the intracellular ATP levels. RESULTS: ATG (2.5, 5 and 10 µmol/L) inhibited cell death and unfolded protein response (UPR) in a concentration-dependent manner in cells treated with the ER stress inducer brefeldin A (100 nmol/L). ATG (1, 5 and 10 µmol/L) significantly attenuated protein synthesis in cells through inhibiting mTOR-p70S6K signaling and eEF2 activity, which were partially reversed by silencing AMPKα1 with RNAi. ATG (1-50 µmol/L) reduced intracellular ATP level and activated AMPK through inhibiting complex I-mediated respiration. Pretreatment of cells with the AMPK inhibitor compound C (25 µmol/L) rescued the inhibitory effects of ATG on ER stress. Furthermore, ATG (2.5 and 5 µmol/L) efficiently activated AMPK and reduced the ER stress and cell death induced by palmitate (2 mmol/L) in INS-1 ß cells. CONCLUSION: ATG is an effective ER stress alleviator, which protects cells against ER stress through activating AMPK, thus attenuating protein translation and reducing ER load.
Asunto(s)
Arctium/química , Estrés del Retículo Endoplásmico/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Furanos/farmacología , Lignanos/farmacología , Proteínas Quinasas/metabolismo , Quinasas de la Proteína-Quinasa Activada por el AMP , Animales , Furanos/aislamiento & purificación , Células Hep G2 , Humanos , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/efectos de los fármacos , Lignanos/aislamiento & purificación , Masculino , Palmitatos/farmacología , Biosíntesis de Proteínas/efectos de los fármacos , Ratas , Ratas Wistar , Transducción de Señal/efectos de los fármacos , Respuesta de Proteína Desplegada/efectos de los fármacosRESUMEN
Catch-up growth (CUG) after food restriction can increase the risks for insulin resistance-related diseases, and to our knowledge, no previous studies have addressed how bone is influenced by CUG when refeeding diet content differs. The objective of this study was to investigate the bone status resulting from CUG induced by varying refeeding dietary patterns, and to assess the potential influencing factors and the effect of resveratrol on bone status during CUG. Experimental rats were randomly divided into five groups: normal chow (NC) group; CUG group (CUG, containing two subgroups, respectively, refeeding with normal chow or high-fat diet); high-fat diet (HF) group; and resveratrol intervention groups (CUGE and HFE). Bone parameters were detected by dual-energy X-ray absorptiometry. Serum concentrations of tumor necrosis factor (TNF)-α, body weight and food intake were also recorded. Our results showed that food restriction induced a significant decrease in bone parameters. Eight-week CUG by normal chow had a greater degree of improvement in bone mineral density than high-fat diet, and even returned to normal level similar to NC. Bone parameters were elevated in varying degrees in the HF group compared with the NC group. In the resveratrol intervention groups, bone parameters significantly increased. Furthermore, bone parameters were inversely related with serum TNF-α concentrations, but showed positive correlation with body weight. In conclusion, the study shows that CUG can partially reverse the deleterious effects of caloric restriction on bone health, especially in the refeeding with normal chow group. Moreover, resveratrol has a protective effect on bone status during the period of CUG. Serum TNF-α levels and body weight also seem to play an important role in regulating bone parameters.
Asunto(s)
Antioxidantes/farmacología , Huesos/efectos de los fármacos , Restricción Calórica/efectos adversos , Estilbenos/farmacología , Absorciometría de Fotón , Animales , Peso Corporal , Densidad Ósea/efectos de los fármacos , Masculino , Desnutrición/complicaciones , Ratas , Ratas Sprague-Dawley , ResveratrolRESUMEN
The extraction protocol of flavonoids from lotus (Nelumbo nucifera) leaves was optimized through an orthogonal design. The solvent was the most important factor comparing solvent, solvent:tissue ratio, extraction time, and temperature. The highest yield of flavonoids was achieved with 70% methanol-water and a solvent:tissue ratio of 30:1 at 4 °C for 36 h. The optimized analytical method for HPLC was a multi-step gradient elution using 0.5% formic acid (A) and CH3CN containing 0.1% formic acid (B), at a flow rate of 0.6 mL/min. Using this optimized method, thirteen flavonoids were simultaneously separated and identified by high performance liquid chromatography coupled with photodiode array detection/electrospray ionization mass spectrometry (HPLC/DAD/ESI-MS(n)). Five of the bioactive compounds are reported in lotus leaves for the first time. The flavonoid content of the leaves of three representative cultivars was assessed under the optimized extraction and HPLC analytical conditions, and the seed-producing cultivar 'Baijianlian' had the highest flavonoid content compared with rhizome-producing 'Zhimahuoulian' and wild floral cultivar 'Honglian'.