RESUMO
Detrimental molecular processes in multiple sclerosis (MS) lead to the cellular accumulation of lipid peroxidation products and iron in the CNS, which represents the main driving force for ferroptosis. Ferroptosis is an iron-dependent form of regulated cell death, with proposed roles in neurodegeneration, oligodendrocyte loss and neuroinflammation in the pathogenesis of MS. Ferroptosis-related gene expression signature and molecular markers, which could reflect MS severity and progression, are currently understudied in humans. To tackle these challenges, we have applied a curated approach to create and experimentally analyze a comprehensive panel of ferroptosis-related genes covering a wide range of biological processes associated with ferroptosis. We performed the first ferroptosis-related targeted RNAseq on PBMCs from highly distinctive MS phenotype groups: mild relapsing-remitting (RR) (n = 24) and severe secondary progressive (SP) (n = 24), along with protein detection of GPX4 and products of lipid peroxidation (MDA and 4-HNE). Out of 138 genes, 26 were differentially expressed genes (DEGs), indicating changes in both pro- and anti-ferroptotic genes, representing a molecular signature associated with MS severity. The top three DEGs, as non-core ferroptosis genes, CDKN1A, MAP1B and EGLN2, were replicated by qPCR to validate findings in independent patient groups (16 RR and 16 SP MS). Co-expression and interactions of DEGs were presented as additional valuable assets for deeper understanding of molecular mechanisms and key targets related to MS severity. Our study integrates a wide genetic signature and biochemical markers related to ferroptosis in easily obtainable PBMCs of MS patients with clinical data and disease severity, thus providing novel molecular markers which can complement disease-related changes in the brain and undergo further research as potential therapeutic targets.
Assuntos
Ferroptose , Esclerose Múltipla , Humanos , Transcriptoma , Recidiva Local de Neoplasia , Gravidade do Paciente , Ferro , Prolina Dioxigenases do Fator Induzível por HipóxiaRESUMO
Prostate-specific membrane antigen (PSMA) and caveolin-1 are membrane proteins that are overexpressed in prostate cancer (PCa) and are involved in tumor growth and increase in aggressiveness. The aim of the present study is therefore to evaluate PSMA and caveolin-1 proteins from plasma exosomes as effective liquid biopsy biomarkers for PCa. This study included 39 patients with PCa and 33 with benign prostatic hyperplasia (BPH). The shape and size of the exosomes were confirmed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analysis. Immunogold analysis showed that PSMA is localized to the membrane of exosomes isolated from the plasma of both groups of participants. The relative protein levels of PSMA and caveolin-1 in the plasma exosomes of PCa and BPH patients were determined by Western blot analysis. The relative level of the analyzed plasma exosomal proteins was compared between PCa and BPH patients and the relevance of the exosomal PSMA and caveoin-1 level to the clinicopathological parameters in PCa was investigated. The analysis performed showed an enrichment of exosomal PSMA in the plasma of PCa patients compared to the exosomes of men with BPH. The level of exosomal caveolin-1 in plasma was significantly higher in PCa patients with high PSA levels, clinical-stage T3 or T4 and in the group of PCa patients with aggressive PCa compared to favorable clinicopathological features or tumor aggressiveness. Plasma exosomes may serve as a suitable object for the identification of potential biomarkers for the early diagnosis and prognosis of PCa as well as carriers of therapeutic agents in precision medicine of PCa treatment.
Assuntos
Hiperplasia Prostática , Neoplasias da Próstata , Masculino , Humanos , Hiperplasia Prostática/metabolismo , Próstata/patologia , Caveolina 1/metabolismo , Sérvia , Biomarcadores Tumorais/metabolismo , Neoplasias da Próstata/metabolismo , Antígeno Prostático Específico/metabolismoRESUMO
Polycystic ovary syndrome (PCOS) is a complex disorder characterized by endocrine and metabolic abnormalities such as obesity and insulin resistance. PCOS is also associated with psychiatric disorders and cognitive impairment. The animal model of PCOS was induced by treating rats with 5α-dihydrotestosterone (5α-DHT) and additionally modified to induce adiposity by litter size reduction (LSR). Spatial learning and memory were assessed using the Barnes Maze test, and striatal markers of synaptic plasticity were analyzed. Striatal insulin signaling was estimated by the levels of insulin receptor substrate 1 (IRS1), its inhibitory phosphorylation at Ser307, and glycogen synthase kinase-3α/ß (GSK3α/ß) activity. Both LSR and DHT treatment significantly decreased striatal protein levels of IRS1, followed by increased GSK3α/ß activity in small litters. Results of the behavioral study showed that LSR had a negative effect on learning rate and memory retention, whereas DHT treatment did not induce impairment in memory formation. While protein levels of synaptophysin, GAP43, and postsynaptic density protein 95 (PSD-95) were not altered by the treatments, DHT treatment induced an increase in phosphorylation of PSD-95 at Ser295 in both normal and small litters. This study revealed that LSR and DHT treatment suppressed insulin signaling by downregulating IRS1 in the striatum. However, DHT treatment did not have an adverse effect on learning and memory, probably due to compensatory elevation in pPSD-95-Ser295, which had a positive effect on synaptic strength. This implies that hyperandrogenemia in this setting does not represent a threat to spatial learning and memory, opposite to the effect of overnutrition-related adiposity.
Assuntos
Hiperandrogenismo , Resistência à Insulina , Síndrome do Ovário Policístico , Feminino , Humanos , Ratos , Animais , Síndrome do Ovário Policístico/induzido quimicamente , Síndrome do Ovário Policístico/complicações , Síndrome do Ovário Policístico/metabolismo , Hiperandrogenismo/complicações , Hiperandrogenismo/metabolismo , Aprendizagem Espacial , Resistência à Insulina/fisiologia , Insulina/metabolismo , Di-Hidrotestosterona/farmacologia , Obesidade/complicações , Modelos Animais de DoençasRESUMO
Obesity is on the rise worldwide, and consequently, obesity-related non-communicable diseases are as well. Nutritional overload induces metabolic adaptations in an attempt to restore the disturbed balance, and the byproducts of the mechanisms at hand include an increased generation of reactive species. Obesity-related oxidative stress causes damage to vulnerable systems and ultimately contributes to neoplastic transformation. Dysfunctional obese adipose tissue releases cytokines and induces changes in the cell microenvironment, promoting cell survival and progression of the transformed cancer cells. Other than the increased risk of cancer development, obese cancer patients experience higher mortality rates and reduced therapy efficiency as well. The fact that obesity is considered the second leading preventable cause of cancer prioritizes the research on the mechanisms connecting obesity to cancerogenesis and finding the solutions to break the link. Oxidative stress is integral at different stages of cancer development and advancement in obese patients. Hypocaloric, balanced nutrition, and structured physical activity are some tools for relieving this burden. However, the sensitivity of simultaneously treating cancer and obesity poses a challenge. Further research on the obesity-cancer liaison would offer new perspectives on prevention programs and treatment development.
Assuntos
Neoplasias , Obesidade , Humanos , Obesidade/metabolismo , Estresse Oxidativo , Tecido Adiposo/metabolismo , Neoplasias/etiologia , Neoplasias/metabolismo , Citocinas/metabolismo , Microambiente TumoralRESUMO
Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that represents a link between diet-induced inflammation and insulin resistance. Our aim was to examine whether fructose diet affects inflammation and insulin signaling in the prefrontal cortex (PFC) of Mif knockout mice (MIF-KO), and their possible link to neural plasticity and behavior. We analyzed nuclear factor κB (NF-κB) and glucocorticoid signaling, expression of F4/80, IL-1ß, TNF-α, TLR-4, MyD88, arginase 1 (Arg-1), mannose receptor (Mrc-1), and leukemia inhibitory factor (Lif) to assess inflammation in the PFC of C57/BL6J and MIF-KO mice consuming 20% fructose solution for 9 weeks. Insulin receptor (IR), IRS-1 serine phosphorylations (307 and 1101) and activity of PKCα, Akt, GSK-3ß and AMPKα were used to analyze insulin signaling. Brain-derived neurotrophic factor (BDNF) and insulin-like growth factor 1 (IGF-1) mRNA levels, together with synapthophysin and PSD-95 protein level and calcium calmodulin-dependent kinase 2 (CaMKII) activity, were used as plasticity markers. Behavior was examined in elevated plus maze, light dark box and novel object recognition test. The results showed concomitant increase of Tnf-α, Tlr-4, MyD88 and M2 microglia markers (Arg-1, Mrc-1, Lif) in the PFC of MIF-KO, paralleled with unchanged glucocorticoid and insulin signaling. Increase of BDNF and IGF-1 was paralleled with increased CaMKII activity, decreased PSD-95 protein level, anxiogenic behavior, and impaired memory in MIF-KO mice. Fructose feeding restored these parameters in the PFC to the control level and mitigated behavioral changes, suggesting that ameliorating effects of fructose on neuroinflammation and behavior depend on the presence of MIF.
Assuntos
Fatores Inibidores da Migração de Macrófagos , Camundongos , Masculino , Animais , Fator de Crescimento Insulin-Like I/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Glucocorticoides , Fator de Necrose Tumoral alfa/metabolismo , Frutose , Proteína 4 Homóloga a Disks-Large/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Receptor 4 Toll-Like/metabolismo , Inflamação/metabolismo , Dieta , Insulina/metabolismo , Córtex Pré-Frontal/metabolismo , Plasticidade Neuronal , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Polycystic ovary syndrome (PCOS) is a well-known reproductive syndrome usually associated with obesity, insulin resistance, and hyperinsulinemia. Although the first signs of PCOS begin early in adolescence, it is underexplored whether peripubertal obesity predisposes women to PCOS metabolic disturbances. To highlight that, we examined the impact of postnatal overfeeding-induced obesity, achieved by litter size reduction during the suckling period, on metabolic disturbances associated with visceral and subcutaneous adipose tissue (VAT and SAT) function in the 5α-dihydrotestosterone (5α-DHT)-induced animal model of PCOS. We analyzed markers of insulin signaling, lipid metabolism, and energy sensing in the VAT and SAT. Our results showed that postnatally overfed DHT-treated Wistar rats had increased VAT mass with hypertrophic adipocytes, together with hyperinsulinemia and increased HOMA index. In the VAT of these animals, insulin signaling remained unchanged while lipogenic markers decreased, which was accompanied by increased AMPK activation. In the SAT of the same animals, markers of lipogenesis and lipolysis increased, while the activity of AMPK decreased. Taken together, obtained results showed that postnatal overfeeding predisposes development of PCOS systemic insulin resistance, most likely as a result of worsened metabolic function of SAT, while VAT preserved its tissue insulin sensitivity through increased activity of AMPK.
Assuntos
Resistência à Insulina , Síndrome do Ovário Policístico , Proteínas Quinases Ativadas por AMP/metabolismo , Tecido Adiposo/metabolismo , Animais , Feminino , Humanos , Insulina/metabolismo , Resistência à Insulina/fisiologia , Obesidade/metabolismo , Síndrome do Ovário Policístico/metabolismo , Ratos , Ratos Wistar , Gordura Subcutânea/metabolismoRESUMO
A number of alterations have been identified in lipid metabolism within adipose tissue and liver in obesity. Less is known about the capacity of skeletal muscle for the metabolism of fatty acids in obesity-related insulin resistance, though it is evident that dry cow muscles may contain increased triglyceride content. The current study was therefore undertaken to evaluate the skeletal muscle expression of proteins of the fatty acid metabolism in dry cows with different body condition scores (BCS). Sixteen Holstein-Friesian close-up cows were divided into 2 equal groups based on their BCS as optimal (3.25 ≤ BCS ≤ 3.5) and high (4.0 ≤ BCS ≤ 4.25). Blood samples collection and skeletal muscle biopsies were carried out at day 10 before calving. Blood serum was assayed for concentration of resistin using a bovine specific ELISA. Protein expression of insulin receptor beta subunit (IRß), glucose transporter 4 (GLUT4), fatty acid translocase (FAT/CD36), fatty acid transporter 1 (FATP1), carnitine palmitoyltransferase 1 (CPT1), AMP-acitvated protein kinase (AMPK) and lipin 1 were analyzed in semitendinosus muscle by immunoblot. Resistin differed non-significantly between high-BCS and optimal-BCS cows. Insulin-resistant lipid metabolism in obese cows was paralleled with increased skeletal muscle expression of lipin 1 and GLUT4, and decreased expression of IRß and FATP1. These data suggest that in obesity-related insulin resistance, metabolic capacity in dry cow skeletal muscles appears to be organized towards the synthesis of signaling intermediates rather than fatty acids oxidation and that altered fatty acid uptake does not contribute to this disposition.
Assuntos
Doenças dos Bovinos , Resistência à Insulina , Animais , Antígenos CD36/metabolismo , Bovinos , Doenças dos Bovinos/metabolismo , Ácidos Graxos/metabolismo , Feminino , Insulina , Resistência à Insulina/fisiologia , Lactação/fisiologia , Músculo Esquelético/metabolismo , Obesidade/metabolismo , Obesidade/veterinária , Compostos Orgânicos , Resistina/metabolismoRESUMO
Appetite regulation in the hypothalamus is dependent on hormonal signals from the periphery, such as insulin and leptin, and can be modulated by both sugar-rich diet and stress. Our aim was to explore the effects of 9-week feeding with 20% fructose solution combined with 4-week chronic unpredictable stress, on appetite-regulating neuropeptides and modulatory role of leptin and insulin signalling in the hypothalamus of male Wistar rats. Energy intake, body mass and adiposity, as well as circulatory leptin and insulin concentrations were assessed. Hypothalamic insulin signalling was analysed at the level of glucose transporters, as well as at the protein level and phosphorylation of insulin receptor, insulin receptor supstrate-1, Akt and ERK. Phosphorylation of AMP-activated protein kinase (AMPK), level of protein tyrosine phosphatase 1B (PTP1B) and expression of leptin receptor (ObRb) and suppressor of cytokine signalling 3 (SOCS3) were also analysed, together with the expression of orexigenic agouti-related protein (AgRP) and anorexigenic proopiomelanocortin (POMC) neuropeptides. The results revealed that stress decreased body mass and adiposity, blood leptin level and expression of ObRb, SOCS3 and POMC, while combination with fructose diet led to marked increase of AgRP, associated with AMPK phosphorylation despite increased plasma insulin. Reduced Akt, enhanced ERK activity and elevated PTP1B were also observed in the hypothalamus of these animals. In conclusion, our results showed that joint effects of fructose diet and stress are more deleterious than the separate ones, since inappropriate appetite control in the hypothalamus may provide a setting for the disturbed energy homeostasis in the long run.
Assuntos
Neuropeptídeos , Pró-Opiomelanocortina , Proteínas Quinases Ativadas por AMP/metabolismo , Proteína Relacionada com Agouti/metabolismo , Proteína Relacionada com Agouti/farmacologia , Animais , Citocinas/metabolismo , Dieta , Frutose/efeitos adversos , Frutose/metabolismo , Glucose/metabolismo , Hipotálamo/metabolismo , Insulina , Leptina , Masculino , Neuropeptídeos/metabolismo , Neuropeptídeos/farmacologia , Fosforilação , Pró-Opiomelanocortina/metabolismo , Pró-Opiomelanocortina/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 1/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Wistar , Receptor de Insulina/metabolismo , Receptores para Leptina/metabolismoRESUMO
The modern lifestyle brings both excessive fructose consumption and daily exposure to stress which could lead to metabolic disturbances and type 2 diabetes. Muscles are important points of glucose and lipid metabolism, with a crucial role in the maintenance of systemic energy homeostasis. We investigated whether 9-week fructose-enriched diet, with and without exposure to 4-week unpredictable stress, disturbs insulin signaling in the skeletal muscle of male rats and evaluated potential contributory roles of muscle lipid metabolism, glucocorticoid signaling and inflammation. The combination of fructose-enriched diet and stress increased peroxisome proliferator-activated receptors-α and -δ and stimulated lipid uptake, lipolysis and ß-oxidation in the muscle of fructose-fed stressed rats. Combination of treatment also decreased systemic insulin sensitivity judged by lower R-QUICKI, and lowered muscle protein content and stimulatory phosphorylations of insulin receptor supstrate-1 and Akt, as well as the level of 11ß-hydroxysteroid dehydrogenase type 1 and glucocorticoid receptor. At the same time, increased levels of protein tyrosine phosphatase-1B, nuclear factor-κB, tumor necrosis factor-α, were observed in the muscle of fructose-fed stressed rats. Based on these results, we propose that decreased glucocorticoid signaling in the skeletal muscle can make a setting for lipid-induced inflammation and the development of insulin resistance in fructose-fed stressed rats.
Assuntos
Frutose/administração & dosagem , Glucocorticoides/metabolismo , Inflamação/metabolismo , Metabolismo dos Lipídeos , Músculo Esquelético/metabolismo , Estresse Fisiológico/fisiologia , Animais , Frutose/efeitos adversos , Humanos , Inflamação/etiologia , Resistência à Insulina/fisiologia , Masculino , Modelos Biológicos , Ratos , Ratos Wistar , Receptores de Glucocorticoides/metabolismo , Transdução de SinaisRESUMO
PURPOSE: Polycystic ovary syndrome (PCOS) is a complex reproductive disorder often associated with obesity, insulin resistance, and dyslipidemia. Hormonal changes in PCOS may also include altered glucocorticoid signaling. Our aim was to examine whether alterations in hepatic glucocorticoid signaling are associated with disturbances of glucose and lipid metabolism in animal model of PCOS. METHODS: Female rats, 3 weeks old, were subcutaneously implanted with 5α-dihydrotestosterone (DHT) or placebo pellets for 90 days to induce PCOS. Expression of 11ß-hydroxysteroid dehydrogenase 1 (11ßHSD1) and A-ring reductases (5α and 5ß), as well as intracellular distribution of glucocorticoid receptor (GR) and expression of its regulated genes were examined in the liver. Proteins of hepatic lipid and carbohydrate metabolism and markers of inflammation were also assessed. RESULTS: DHT treatment induced increase in body and liver mass, as well as in triglycerides and free fatty acids levels in plasma. Elevation of 11ßHSD1 and reduction of 5α-reductase expression was observed together with increased hepatic corticosterone concentration and nuclear GR activation. Induced expression of Krüppel-like factor 15 and decreased expression of genes for proinflammatory cytokines and de novo lipogenesis (DNL) were detected in the liver of DHT-treated rats, while DNL regulators and proinflammatory markers were not changed. However, increased mRNA levels of stearoyl-CoA desaturase and apolipoprotein B were observed in DHT animals. CONCLUSIONS: DHT treatment stimulated hepatic glucocorticoid prereceptor metabolism through increased corticosterone availability which is associated with enhanced GR activation. This does not affect gluconeogenesis and DNL, but could be linked to stimulated triglyceride synthesis and hypertriglyceridemia.
Assuntos
Síndrome do Ovário Policístico , Animais , Di-Hidrotestosterona , Modelos Animais de Doenças , Feminino , Glucocorticoides/metabolismo , Humanos , Metabolismo dos Lipídeos , Fígado/metabolismo , Síndrome do Ovário Policístico/induzido quimicamente , Síndrome do Ovário Policístico/metabolismo , Ratos , Ratos WistarRESUMO
Foods and food products that contain polyphenols are proposed to modulate risk of cardiovascular disease. The aim of this three-arm, crossover, randomized, double-blind, placebo-controlled intervention study was to examine the impact of Aronia melanocarpa juice (AMJ), high-polyphenol (AMJ treatment, 1.17 g/100 mL polyphenols) and low-polyphenol (dAMJ treatment, 0.29 g/100 mL polyphenols) dose, on the transcriptome in peripheral blood mononuclear cells (PBMC) of 19 subjects at cardiovascular risk. Transcriptome data were obtained by microarray. Bioinformatic functional annotation analysis was performed on both the whole transcriptome datasets and the differentially expressed genes (DEGs). Expression of selected DEGs was validated by RT-qPCR. Administration of AMJ and dAMJ treatments during the two consecutive four-week treatment periods had additive effects on PBMC transcriptome profiles, with the most pronounced and specific effect noticed for AMJ in the last treatment period (TP3) of the trial. Between the high-dose and low-dose treatments in TP3, there was a multitude of overlapping DEGs and DEG-enriched biological processes and pathways, which primarily included immunomodulation and regulation of cell proliferation/death. Increased expression of TNF, IL1B, IL8, RGS1, OSM, and DUSP2 in TP3 was confirmed by RT-qPCR. The results suggest the immunomodulatory effects of prolonged habitual consumption of polyphenol-rich aronia juice in individuals at cardiovascular risk.
Assuntos
Doenças Cardiovasculares , Fatores de Risco de Doenças Cardíacas , Leucócitos Mononucleares/metabolismo , Photinia/química , Extratos Vegetais/farmacologia , RNA Mensageiro/metabolismo , Doenças Cardiovasculares/genética , Morte Celular , Proliferação de Células , Método Duplo-Cego , Feminino , Sucos de Frutas e Vegetais , Humanos , Masculino , Polifenóis/farmacologia , Fatores de Risco , TranscriptomaRESUMO
Both a diet rich in fructose and chronic stress exposure induce metabolic and cardiovascular disturbances. The aim of this study was to examine the effects of the fructose-rich diet and chronic stress, separately and in combination, on insulin signaling and molecules regulating glycogen synthesis and ion transport in the heart, and to reveal whether these effects coincide with changes in glucocorticoid receptor (GR) activation. Male Wistar rats were subjected to 10% fructose in drinking water and/or to chronic unpredictable stress for 9 weeks. Protein expression and/or phosphorylation of the insulin receptor (IR), protein tyrosine phosphatase 1B, insulin receptor substrate 1 (IRS1), protein kinase B (Akt), extracellular signal-regulated kinase 1/2 (ERK1/2), glycogen synthase kinase-3ß (GSK-3ß) and Na+/K+-ATPase α-subunits in cardiac tissue were analyzed by western blot. GR distribution between cytosolic and nuclear fractions was also analyzed. The fructose-rich diet decreased the level of pERK1/2 (Thr202/Tyr204) and pGSK-3ß (Ser9) independently of stress, while chronic stress increased the IRS1 content and prevented the fructose diet-induced decrease of the pAkt (Ser473) level. The fructose-rich diet in combination with chronic stress reduced the protein content of cardiac IR and attenuated IRS1 upregulation. Separate treatments increased the protein content of Na+/K+-ATPase α1- and α2-subunits, while after combined treatment the α2 content was at the control level and the α1 content was lower than the control level. The effect of combined treatment on cardiac IR and α2-subunit expression could be mediated by increased GR nuclear accumulation. Our study provides new insights into the effects of chronic stress and a combination of the fructose diet and chronic stress on the studied molecules in the heart.
Assuntos
Frutose/farmacologia , Glicogênio Sintase Quinase 3 beta/efeitos dos fármacos , Coração/efeitos dos fármacos , Receptor de Insulina/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/efeitos dos fármacos , Animais , Dieta , Glicogênio Sintase Quinase 3 beta/metabolismo , Masculino , Ratos , Ratos Wistar , Receptor de Insulina/metabolismo , Transdução de Sinais/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/metabolismo , Estresse FisiológicoRESUMO
Macrophage migration inhibitory factor (MIF) is a multifunctional cytokine well known for its role in inflammation enhancement. However, a growing body of evidence is emerging on its role in energy metabolism in insulin sensitive tissues such as hippocampus, a brain region implicated in cognition, learning and memory. We hypothesized that genetic deletion of MIF may result in the specific behavioral changes, which may be linked tо impairments in brain or systemic insulin sensitivity by possible changes of the hippocampal synaptic plasticity. To assess memory, exploratory behavior and anxiety, three behavioral tests were applied on Mif gene-deficient (MIF-/-) and "wild type" C57BL/6J mice (WT). The parameters of systemic and hippocampal insulin sensitivity were also determined. The impact of MIF deficiency on hippocampal plasticity was evaluated by analyzing the level of synaptosomal polysialylated-neural cell adhesion molecule (PSA-NCAM) plasticity marker and mRNA levels of different neurotrophic factors. The results showed that MIF-/- mice exhibit emphasized anxiety-like behaviors, as well as impaired recognition memory, which may be hippocampus-dependent. This behavioral phenotype was associated with impaired systemic insulin sensitivity and attenuated hippocampal insulin sensitivity, characterized by increased inhibitory Ser307 phosphorylation of insulin receptor substrate 1 (IRS1). Finally, MIF-/- mice displayed a decreased hippocampal PSA-NCAM level and unchanged Bdnf, NT-3, NT-4 and Igf-1 mRNA levels. The results suggest that the lack of MIF leads to disturbances of systemic and hippocampal insulin sensitivity, which are possibly responsible for memory deficits and anxiety, most likely through decreased PSA-NCAM-mediated neuroplasticity rather than through neurotrophic factors.
Assuntos
Comportamento Animal/fisiologia , Hipocampo/metabolismo , Resistência à Insulina/genética , Oxirredutases Intramoleculares/genética , Fatores Inibidores da Migração de Macrófagos/genética , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Ácidos Siálicos/metabolismo , Animais , Ansiedade/genética , Ansiedade/metabolismo , Comportamento Exploratório/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Transtornos da Memória/genética , Transtornos da Memória/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Plasticidade Neuronal/genéticaRESUMO
The adipose tissue renin-angiotensin system (RAS) is proposed to be a pathophysiological link between adipose tissue dysregulation and metabolic disorders induced by a fructose-rich diet (FRD). RAS can act intracellularly. We hypothesized that adipocyte nuclear membranes possess angiotensin receptor types 1 and 2 (AT1R and AT2R), which couple to nuclear signaling pathways and regulate oxidative gene expression under FRD conditions. We analyzed the effect of consumption of 10% fructose solution for 9 weeks on biochemical parameters, adipocyte morphology, and expression of AT1R, AT2R, AT1R-associated protein (ATRAP), NADPH oxidase 4 (NOX4), matrix metalloproteinase-9 (MMP-9), and manganese superoxide dismutase (MnSOD) in adipose tissue of Wistar rats. We detected AT1R and AT2R in the nuclear fraction. FRD reduced the level of angiotensin receptors in the nucleus, while increased AT1R and decreased AT2R levels were observed in the plasma membrane. FRD increased the ATRAP mRNA level and decreased MnSOD mRNA and protein levels. No significant differences were observed for MMP-9 and NOX4 mRNA levels. These findings coincided with hyperleptinemia, elevated blood pressure and triglycerides, and unchanged visceral adipose tissue mass and morphology in FRD rats. Besides providing evidence for nuclear localization of angiotensin receptors in visceral adipose tissue, this study demonstrates the different effects of FRD on AT1R expression in different cellular compartments. Elevated blood pressure and decreased antioxidant capacity in visceral fat of fructose-fed rats were accompanied by an increased AT1R level in the plasma membrane, while upregulation of ATRAP and a decrease of nuclear membrane AT1R suggest an increased capacity for attenuation of excessive AT1R signaling and visceral adiposity.
Assuntos
Membrana Celular/química , Núcleo Celular/metabolismo , Carboidratos da Dieta , Frutose/farmacologia , Receptor Tipo 1 de Angiotensina/metabolismo , Receptor Tipo 2 de Angiotensina/metabolismo , Adipócitos/química , Adipócitos/metabolismo , Animais , Peso Corporal , Núcleo Celular/química , Frutose/administração & dosagem , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Receptor Tipo 1 de Angiotensina/química , Receptor Tipo 1 de Angiotensina/genética , Receptor Tipo 2 de Angiotensina/química , Receptor Tipo 2 de Angiotensina/genética , ATPase Trocadora de Sódio-Potássio/genética , ATPase Trocadora de Sódio-Potássio/metabolismoRESUMO
Polycystic ovary syndrome is a heterogeneous endocrine and metabolic disorder associated with abdominal obesity, dyslipidemia and insulin resistance. Since abdominal obesity is characterized by low-grade inflammation, the aim of the study was to investigate whether visceral adipose tissue inflammation linked to abdominal obesity and dyslipidemia could lead to impaired insulin sensitivity in the animal model of polycystic ovary syndrome.Female Wistar rats were treated with nonaromatizable 5α-dihydrotestosterone pellets in order to induce reproductive and metabolic characteristics of polycystic ovary syndrome. Glucose, triglycerides, non-esterified fatty acids and insulin were determined in blood plasma. Visceral adipose tissue inflammation was evaluated by the nuclear factor kappa B intracellular distribution, macrophage migration inhibitory factor protein level, as well as TNFα, IL6 and IL1ß mRNA levels. Insulin sensitivity was assessed by intraperitoneal glucose tolerance test and homeostasis model assessment index, and through analysis of insulin signaling pathway in the visceral adipose tissue.Dihydrotestosterone treatment led to increased body weight, abdominal obesity and elevated triglycerides and non-esterified fatty acids, which were accompanied by the activation of nuclear factor kappa B and increase in macrophage migration inhibitory factor, IL6 and IL1ß levels in the visceral adipose tissue. In parallel, insulin sensitivity was affected in 5α-dihydrotestosterone-treated animals only at the systemic and not at the level of visceral adipose tissue.The results showed that abdominal obesity and dyslipidemia in the animal model of polycystic ovary syndrome were accompanied with low-grade inflammation in the visceral adipose tissue. However, these metabolic disturbances did not result in decreased tissue insulin sensitivity.
Assuntos
Di-Hidrotestosterona/efeitos adversos , Insulina/metabolismo , Gordura Intra-Abdominal/metabolismo , Obesidade Abdominal/metabolismo , Síndrome do Ovário Policístico/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Di-Hidrotestosterona/farmacologia , Modelos Animais de Doenças , Feminino , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Gordura Intra-Abdominal/patologia , Obesidade Abdominal/induzido quimicamente , Obesidade Abdominal/patologia , Síndrome do Ovário Policístico/induzido quimicamente , Síndrome do Ovário Policístico/patologia , Ratos , Ratos WistarRESUMO
Background: Rapid advancements in the field of metastatic breast cancer (mBC) add to the complexity of managing patients with this disease. An educational needs assessment of multidisciplinary mBC clinicians was executed to identify practice performance gaps and recommend educational strategies aimed at closing these gaps. Methods: To ensure a collection of reliable data for assessment, a systematic process was used to design, develop, and validate the tools that were used. This grounded theory approach included assessment and confirmation by clinical experts and validation testing within the target audiences. A mixed-methods approach was used to identify practice performance gaps in care, using both qualitative in-depth interviews and quantitative surveying. The quantitative survey assessment consisted of 2 main sections: the Clinician Change Readiness Inventory tool and a Clinical Knowledge and Practice Assessment. Results: The study included 42 clinicians in the interview phase and 186 clinicians in the survey phase from 36 different states. Five key practice performance gaps were identified: (1) selecting optimal treatment, (2) personalizing therapy, (3) monitoring mBC, (4) engaging in effective communication, and (5) balancing patient access and time. Most of the gaps overlap and are related to the integral role communication plays in management decision-making in mBC. Conclusions: Awareness of the key practice performance gaps is critical to inform improvements in quality care.
Assuntos
Neoplasias da Mama/terapia , Competência Clínica , Avaliação Educacional/métodos , Comunicação Interdisciplinar , Oncologia/educação , Neoplasias da Mama/patologia , Estudos de Coortes , Comunicação , Educação Médica Continuada/métodos , Feminino , Teoria Fundamentada , Pessoal de Saúde/educação , Humanos , Inquéritos e Questionários , Estados UnidosRESUMO
Knowledge of the antioxidant defense in the stress-responding structures of the CNS is of crucial importance, since oxidative damage is a phenomenon accompanying many stress-related disorders. Regulation of antioxidative and anti-inflammatory defense through Nrf2 (nuclear factor 2 eritroid related factor 2) pathway has emerged as a promising approach for neuroprotection. In this study, we used chronic social isolation of male Wistar rats to induce depressive-like behavior. We hypothesized that Nrf2-Keap1 pathway is compromised in the limbic brain after prolonged stress. Since subcellular trafficking of Nrf2 and its inhibitor Keap1 (Kelch ECH associating protein 1) is essential for the activation of Nrf2, we determined their protein level in cytosolic and nuclear compartments of hippocampus and prefrontal cortex (PFC). We also determined mRNA levels of Nrf2-regulated genes involved in the production and utilization of glutathione, glutamate cysteine ligase (Gclm), glutathione S-transferase (Gsta3) and glutathione reductase (Gsr). Our results showed that chronic isolation induced anxiety and depressive-like behavior, decreased Nrf2 and in parallel increased Keap1 and nuclear factor kappa B (NFκB) in the hippocampus, which were not accompanied by expression profiles of Nrf2-regulated genes. Chronically stressed rats challenged with acute stress failed to induce any response of examined genes in either of brain structures, even though Nrf2/Keap1 was altered, while in naïve animals Nrf2 activity corresponded with an expression of Nrf2-regulated genes. Our results reveal maladaptive character of chronic stress at Nrf2/Keap1 level followed by pro-inflammatory conditions, and suggest a possible role of these alterations in pathogenesis of depressive/anxiety disorders.
Assuntos
Hipocampo/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Córtex Pré-Frontal/metabolismo , Isolamento Social , Estresse Psicológico/metabolismo , Animais , Ansiedade/metabolismo , Núcleo Celular/metabolismo , Doença Crônica , Citosol/metabolismo , Depressão/metabolismo , Glutamato-Cisteína Ligase/metabolismo , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch , Masculino , NF-kappa B/metabolismo , RNA Mensageiro/metabolismo , Ratos Wistar , Transdução de Sinais , Isolamento Social/psicologia , Estresse Psicológico/psicologiaRESUMO
OBJECTIVES: High fructose diet has been shown to have damaging effects on the hippocampus, a brain region critical for learning and memory. Fructose-induced hippocampal dysfunction may arise from insulin resistance and inflammation, and from concomitant changes in plasticity-related presynaptic proteins. We hypothesized that long-term access to fructose (10% and 60% solutions over a period of 9 weeks) affects insulin sensitivity, hippocampal inflammation, and synaptic plasticity in male Wistar rats. METHODS: We used the area under curve (AUC) glucose value and inhibitory Ser³°7 phosphorylation of hippocampal insulin receptor substrate 1 (IRS-1) as hallmarks of insulin resistance. To examine inflammatory state, we analysed protein levels and intracellular redistribution of glucocorticoid receptor and nuclear factor-κB (NFκB), as well as mRNA levels of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1ß (IL-1ß). Polysialylated neural cell adhesion molecule (PSA-NCAM) protein was used as a synaptic plasticity marker. RESULTS: The results indicate different impacts of diverse fructose-enriched diets on insulin sensitivity and hippocampal inflammation and plasticity. Long-term ingestion of 10% fructose solution led to increase in AUC glucose value, as well as to elevation in hippocampal IRS-1 Ser³°7 phosphorylation and increase in IL-6 mRNA. In rats consuming 60% fructose, the level of PSA-NCAM was reduced, in parallel with augmented glucocorticoid signalization. DISCUSSION: The results showed that long-term consumption of 10% fructose solution induces hippocampal insulin resistance and inflammation, with no concomitant plasticity changes. Interestingly, rats fed with higher concentrations of fructose displayed impaired plastic response of the hippocampus, coinciding with augmented glucocorticoid signalling, which may provide a basis for cognitive deficits associated with metabolic syndrome.
Assuntos
Carboidratos da Dieta/efeitos adversos , Frutose/efeitos adversos , Hipocampo/metabolismo , Resistência à Insulina , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Plasticidade Neuronal , Neurônios/metabolismo , Ácidos Siálicos/metabolismo , Animais , Biomarcadores/metabolismo , Citocinas/genética , Citocinas/metabolismo , Carboidratos da Dieta/administração & dosagem , Frutose/administração & dosagem , Hipocampo/imunologia , Proteínas Substratos do Receptor de Insulina/metabolismo , Masculino , NF-kappa B/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/imunologia , Fosforilação , Processamento de Proteína Pós-Traducional , Transporte Proteico , Distribuição Aleatória , Ratos Wistar , Receptores de Glucocorticoides/metabolismoRESUMO
Polycystic ovary syndrome (PCOS) is a reproductive and metabolic disorder characterized by hyperandrogenism, ovulatory dysfunction, visceral obesity and insulin resistance. We hypothesized that changes in glucocorticoid metabolism and signaling in the visceral adipose tissue may contribute to disturbances of lipid metabolism in the rat model of PCOS obtained by 5α-dihydrotestosterone (DHT) treatment of prepubertal female Wistar rats. The results confirmed that DHT treatment caused anovulation, obesity and dyslipidemia. Enhanced glucocorticoid prereceptor metabolism, assessed by elevated intracellular corticosterone and increased 11 beta-hydroxysteroid dehydrogenase type 1 mRNA and protein levels, was accompanied by glucocorticoid receptor (GR) nuclear accumulation. In concert with the increased expression of GR-regulated prolipogenic genes (lipin-1, sterol regulatory element binding protein 1, fatty acid synthase, phosphoenolpyruvate carboxykinase), histological analyses revealed hypertrophic adipocytes. The results suggest that glucocorticoids influence lipid metabolism in the visceral adipose tissue in the way that may contribute to pathogenesis of metabolic disturbances associated with PCOS.
Assuntos
Adipócitos/metabolismo , Androgênios/efeitos adversos , Di-Hidrotestosterona/efeitos adversos , Glucocorticoides/metabolismo , Gordura Intra-Abdominal/metabolismo , Síndrome do Ovário Policístico/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/biossíntese , Adipócitos/patologia , Androgênios/farmacologia , Animais , Di-Hidrotestosterona/farmacologia , Ácido Graxo Sintase Tipo I/biossíntese , Feminino , Gordura Intra-Abdominal/patologia , Proteínas Nucleares/biossíntese , Obesidade/etiologia , Obesidade/metabolismo , Obesidade/patologia , Fosfoenolpiruvato Carboxiquinase (ATP)/biossíntese , Síndrome do Ovário Policístico/induzido quimicamente , Síndrome do Ovário Policístico/complicações , Síndrome do Ovário Policístico/patologia , Ratos , Ratos Wistar , Receptores de Glucocorticoides/biossíntese , Proteína de Ligação a Elemento Regulador de Esterol 1/biossínteseRESUMO
PURPOSE: High fructose consumption provokes metabolic perturbations that result in chronic low-grade inflammation and insulin resistance. Glucocorticoids, potent anti-inflammatory hormones, have important role in pathogenesis of diet-induced metabolic disturbances. The aim of this study was to examine the link between glucocorticoid metabolism and inflammation in the liver of fructose-fed rats. METHODS: Fructose-fed male Wistar rats consumed 60% fructose solution for 9 weeks. Glucocorticoid prereceptor metabolism and signaling were analyzed by measuring the level of 11ß-hydroxysteroid dehydrogenase type 1 (11ßHSD1) and hexose-6-phosphate dehydrogenase expression, as well as via determination of intracellular corticosterone concentration, glucocorticoid receptor subcellular distribution and expression of its target gene, phosphoenolpyruvate carboxykinase. Nuclear factor kappa B (NFκB), tumor necrosis factor alpha (TNFα) and the level of inhibitory phosphorylation of insulin receptor substrate-1 (IRS-1) on Ser(307) were analyzed as markers of hepatic inflammation. The protein and/or mRNA levels of all examined molecules were assessed by Western blot and/or qPCR. RESULTS: Fructose-rich diet led to an enhancement of 11ßHSD1 protein level in the liver, without affecting intracellular level of corticosterone and downstream glucocorticoid signaling. On the other hand, proinflammatory state was achieved through NFκB activation and increased TNFα expression, while elevated level of inhibitory phosphorylation of IRS-1 was observed as an early hallmark of insulin resistance. CONCLUSION: High-fructose diet does not influence hepatic glucocorticoid signaling downstream of the receptor, permitting development of NFκB-driven inflammation. The alteration in 11ßHSD1 expression is most likely the consequence of enhanced inflammation, finally leading to disruption of insulin signaling in the rat liver.