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1.
Clin Nephrol ; 101(1): 9-16, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37997942

RESUMO

INTRODUCTION: Patients on maintenance hemodialysis show lower serological response to mRNA vaccines. Main causes that contribute to this phenomenon are uremic milieu and older age. However, there are no data on the impact of body composition parameters to humoral response. MATERIALS AND METHODS: In this retrospective study, we used data from adult patients on maintenance hemodialysis who received vaccination with 2 doses of BNT162b2. Quantitative determination of antibodies to SARS-CoV-2 spike (S) protein receptor binding domain was performed using the Elecsys immunoassay. Antibody levels higher than 0.8 and 264 U/mL were considered positive and protective, respectively. Body composition parameters were assessed using multifrequency bioelectrical impedance spectroscopy. RESULTS: Overall, 49 patients were included in the study. Three weeks after the 1st vaccination, 34% of patients, and 3 weeks and 3 months after the 2nd vaccination, 100% of patients had detectable titers. Protective titer was developed in 43% of patients 3 weeks after the 2nd vaccination and then decreased to 24% 3 months after the 2nd vaccination. More years on dialysis were correlated to the absence of protective titers. Higher prediction marker values correlated to poor antibody response, and phase angle was negatively associated with the development of protective titers. Patients with protective titers at 3 months after the 2nd vaccination had significantly lower prediction marker and higher phase angle values. CONCLUSION: Parameters of body composition correlate and affect antibody response in patients on hemodialysis. The main observation is that immunogenicity of mRNA vaccines is influenced by phase angle and prediction marker.


Assuntos
COVID-19 , Adulto , Humanos , COVID-19/prevenção & controle , Diálise Renal , SARS-CoV-2 , Vacina BNT162 , Estudos Retrospectivos , Vacinas de mRNA , Composição Corporal , RNA Mensageiro , Vacinação , Anticorpos Antivirais
2.
Int J Mol Sci ; 23(23)2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36499229

RESUMO

Data on animals emphasize the importance of the neuronal glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) for feeding suppression, although it is unclear whether astrocytes participate in the transduction of anorectic GLP-1R-dependent signals. In humans, the brain circuitry underlying these effects remains insufficiently investigated. The present study aimed to explore GLP-1R protein expression in the human hypothalamus and its correlation with body mass index (BMI). Sections of hypothalamus from 28 autopsy cases, 11 with normal weight (BMI < 25 kg/m2) and 17 with non-normal weight (BMI ≥ 25 kg/m2), were examined using immunohistochemistry and double immunofluorescence labeling. Prominent GLP-1R immunoexpression was detected in neurons of several hypothalamic nuclei, including paraventricular, supraoptic, and infundibular nuclei; the lateral hypothalamic area (LH); and basal forebrain nuclei. Interestingly, in the LH, GLP-1R was significantly decreased in individuals with BMI ≥ 25 kg/m2 compared with their normal weight counterparts (p = 0.03). Furthermore, GLP-1R was negatively correlated (τb = −0.347, p = 0.024) with BMI levels only in the LH. GLP-1R extensively colocalized with the anorexigenic and antiobesogenic neuropeptide nucleobindin-2/nesfatin-1 but not with the astrocytic marker glial fibrillary acidic protein. These data suggest a potential role for GLP-1R in the regulation of energy balance in the human hypothalamus. In the LH, an appetite- and reward-related brain region, reduced GLP-1R immunoexpression may contribute to the dysregulation of homeostatic and/or hedonic feeding behavior. Possible effects of NUCB2/nesfatin-1 on central GLP-1R signaling require further investigation.


Assuntos
Receptor do Peptídeo Semelhante ao Glucagon 1 , Neuropeptídeos , Animais , Humanos , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Índice de Massa Corporal , Hipotálamo/metabolismo , Neuropeptídeos/metabolismo , Núcleo Arqueado do Hipotálamo/metabolismo
3.
Kidney Int ; 99(1): 102-116, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32818518

RESUMO

The nuclear factor erythroid 2-related factor 2 (Nrf2) pathway upregulates key cellular defenses. Clinical trials are utilizing pharmacologic Nrf2 inducers such as bardoxolone methyl to treat chronic kidney disease, but Nrf2 activation has been linked to a paradoxical increase in proteinuria. To understand this effect, we examined genetically engineered mice with elevated Nrf2 signaling due to reduced expression of the Nrf2 inhibitor, Kelch-like ECH-associated protein 1 (Keap1). These Keap1FA/FA mice lacked baseline proteinuria but exhibited increased proteinuria in experimental models evoked by adriamycin, angiotensin II, or protein overload. After injury, Keap1FA/FA mice had increased glomerulosclerosis, nephrin disruption and shedding, podocyte injury, foot process effacement, and interstitial fibrosis. Keap1FA/FA mice also had higher daytime blood pressures and lower heart rates measured by radiotelemetry. Conversely, Nrf2 knockout mice were protected from proteinuria. We also examined the pharmacologic Nrf2 inducer CDDO-Im. Compared to angiotensin II alone, the combination of angiotensin II and CDDO-Im significantly increased proteinuria, a phenomenon not observed in Nrf2 knockout mice. This effect was not accompanied by additional increases in blood pressure. Finally, Nrf2 was found to be upregulated in the glomeruli of patients with focal segmental glomerulosclerosis, diabetic nephropathy, fibrillary glomerulonephritis, and membranous nephropathy. Thus, our studies demonstrate that Nrf2 induction in mice may exacerbate proteinuria in chronic kidney disease.


Assuntos
Fator 2 Relacionado a NF-E2 , Insuficiência Renal Crônica , Animais , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Proteinúria/genética , Insuficiência Renal Crônica/genética
4.
Am J Physiol Endocrinol Metab ; 315(2): E180-E195, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29486138

RESUMO

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a canonical regulator of cytoprotective gene expression, but evidence of its cross talk with other pathways, including metabolic ones, is ever increasing. Pharmacologic or systemic genetic activation of the Nrf2 pathway partially protects from obesity in mice and ameliorates fasting hyperglycemia in mice and humans. However, systemic Nrf2 deletion also protects from diet-induced obesity and insulin resistance in mice. To further investigate the effect of the disruption of Nrf2 on obesity in a tissue-specific manner, we focused on adipocytes and hepatocytes with targeted deletion of Nrf2. To this end, mice with cell-specific deletion of Nrf2 in adipocytes (ANKO) or hepatocytes (HeNKO) were fed a high-fat diet (HFD) for 6 mo and showed similar increases in body weight and body fat content. ANKO mice showed a partially deteriorated glucose tolerance, higher fasting glucose levels, and higher levels of cholesterol and nonesterified fatty acids compared with their Control counterparts. The HeNKO mice, though, had lower insulin levels and trended toward improved insulin sensitivity without having any difference in liver triglyceride accumulation. This study compared for the first time two conditional Nrf2 knockout models in adipocytes and in hepatocytes during HFD-induced obesity. None of these models could completely recapitulate the unexpected protection against obesity observed in the whole body Nrf2 knockout mice, but this study points out the differential roles that Nrf2 may play, beyond cytoprotection, in different target tissues and rather suggests systemic activation of the Nrf2 pathway as an effective means of prevention and treatment of obesity and type 2 diabetes.


Assuntos
Adipócitos/metabolismo , Dieta Hiperlipídica/efeitos adversos , Hepatócitos/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Obesidade/genética , Obesidade/metabolismo , Adiposidade/genética , Animais , Glicemia/metabolismo , Composição Corporal/genética , Peso Corporal/genética , Intolerância à Glucose/genética , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Triglicerídeos/sangue
5.
Arch Biochem Biophys ; 591: 57-65, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26701603

RESUMO

The Keap1/Nrf2 pathway, known to regulate the expression of a series of cytoprotective and antioxidant genes, has been studied in the context of obesity and type 2 diabetes; diseases that are characterized by chronic oxidative stress. There is increasing evidence, however, that the transcription factor Nrf2 can crosstalk with pathways not directly related to cytoprotection. Our present work focuses on the effect of Nrf2 on hepatic gluconeogenesis and lipogenesis, two metabolic processes which are dysregulated in the obese/diabetic state. To this end, a genetic mouse model of Nrf2 pathway activation was used (Keap1-hypo; both Keap1 alleles are hypomorphic) and was exposed to a 3-month high-fat diet along with the relevant control wild-type mice. The Keap1-hypo mice were partially protected from obesity, had lower fasting glucose and insulin levels and developed less liver steatosis compared to the wild-type. Key gluconeogenic and lipogenic enzymes were repressed in the Keap1-hypo livers with concomitant activated Ampk signaling. Primary Keap1-hypo hepatocyte cultures also show increased Ampk signaling and repressed glucose production. In conclusion, increased Keap1/Nrf2 signaling in the liver is accompanied by repressed gluconeogenesis and lipogenesis that can, at least partially, explain the ameliorated diabetic phenotype in the Keap1-hypo mice.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas do Citoesqueleto/metabolismo , Gorduras na Dieta/metabolismo , Gluconeogênese/fisiologia , Lipogênese/fisiologia , Fígado/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Proteínas do Citoesqueleto/genética , Dieta Hiperlipídica/métodos , Proteína 1 Associada a ECH Semelhante a Kelch , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Transdução de Sinais/fisiologia
6.
Biochem Soc Trans ; 43(4): 639-44, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26551705

RESUMO

Cancer cells adapt their metabolism to their increased needs for energy and substrates for protein, lipid and nucleic acid synthesis. Nuclear erythroid factor 2-like 2 (Nrf2) pathway is usually activated in cancers and has been suggested to promote cancer cell survival mainly by inducing a large battery of cytoprotective genes. This mini review focuses on metabolic pathways, beyond cytoprotection, which can be directly or indirectly regulated by Nrf2 in cancer cells to affect their survival. The pentose phosphate pathway (PPP) is enhanced by Nrf2 in cancers and aids their growth. PPP has also been found to be up-regulated in non-cancer tissues and other pathways, such as de novo lipogenesis, have been found to be repressed after activation of the Nrf2 pathway. The importance of these Nrf2-regulated metabolic pathways in cancer compared with non-cancer state remains to be determined. Last but not least, the importance of context about Nrf2 and cancer is highlighted as the Nrf2 pathway may be activated in cancers but its pharmacological activators are useful in chemoprevention.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Neoplasias/metabolismo , Via de Pentose Fosfato , Proliferação de Células , Sobrevivência Celular , Regulação Neoplásica da Expressão Gênica , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch , Transdução de Sinais
7.
Obes Pillars ; 10: 100104, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38463533

RESUMO

Background: Hypothalamic obesity represents a clinical condition within the broader spectrum of obesity that frequently eludes detection and appropriate diagnosis. This subset of obesity is characterized by a dearth of established predictive markers and a paucity of standardized therapeutic protocols. The advent and rising prominence of glucagon-like peptide-1 (GLP-1) receptor agonists in the obesity treatment landscape present novel therapeutic avenues for hypothalamic obesity management. Nonetheless, critical inquiries persist concerning the efficacy of GLP-1 receptor (GLP-1R) agonists in this context, particularly regarding their central mechanisms of action and specific impact on hypothalamic obesity. Methods: In this narrative review, we concentrate on analyzing research papers that delineate the detection and function of GLP-1 receptors across various hypothalamic and cerebral regions. Additionally, we examine clinical research papers and reports detailing the application of GLP-1 receptor agonists in treating hypothalamic obesity. Furthermore, we include a concise presentation of a clinical case from our unit for contextual understanding. Results: Currently, the clinical evidence supporting the efficacy of GLP-1 receptor agonists in hypothalamic obesity, as well as the diverse characteristics of this obesity subtype, remains insufficient. Preliminary data suggest that GLP-1R agonists might offer an effective treatment option, albeit with variable outcomes, particularly in younger patient cohorts. From a mechanistic perspective, the presence of GLP-1 receptors in various hypothalamic and broader brain regions potentially underpins the efficacy of GLP-1R agonists, even in instances of hypothalamic damage. Nevertheless, additional research is imperative to establish the functional relevance of these receptors in said brain regions. Conclusion: GLP-1R agonists represent a potential therapeutic option for patients with hypothalamic obesity. However, further clinical and basic/translational research is essential to validate the efficacy of these drugs across different presentations of hypothalamic obesity and to understand the functionality of GLP-1R in the diverse brain regions where they are expressed.

8.
Redox Biol ; 69: 102978, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38048653

RESUMO

Iodide plays a pivotal role in thyroid homeostasis due to its crucial involvement in thyroid hormone biosynthesis. Exposure to pharmacological doses of iodide elicits in the thyroid an autoregulatory response to preserve thyroid function, as well as an antioxidant response that is mediated by the Keap1/Nrf2 signaling pathway. The objective of the present study was to investigate the transcriptional response of the thyroid to excess iodide in a background of enhanced Nrf2 signaling. Keap1 knockdown (Keap1KD) mice that have activated Nrf2 signaling were exposed or not to excess iodide in their drinking water for seven days and compared to respective wild-type mice. RNA-sequencing of individual mouse thyroids identified distinct transcriptomic patterns in response to iodide, with Keap1KD mice showing an attenuated inflammatory response, altered thyroidal autoregulation, and enhanced cell growth/proliferative signaling, as confirmed also by Western blotting for key proteins involved in antioxidant, autoregulatory and proliferative responses. These findings underscore novel gene-environment interactions between the activation status of the Keap1/Nrf2 antioxidant response system and the dietary iodide intake, which may have implications not only for the goiter phenotype of Keap1KD mice but also for humans harboring genetic variations in KEAP1 or NFE2L2 or treated with Nrf2-modulating drugs.


Assuntos
Antioxidantes , Glândula Tireoide , Humanos , Camundongos , Animais , Antioxidantes/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Glândula Tireoide/metabolismo , Estresse Oxidativo , Iodetos/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Interação Gene-Ambiente , Perfilação da Expressão Gênica , Homeostase
9.
Comput Struct Biotechnol J ; 23: 1919-1928, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38711760

RESUMO

The decrease in sequencing expenses has facilitated the creation of reference genomes and proteomes for an expanding array of organisms. Nevertheless, no established repository that details organism-specific genomic and proteomic sequences of specific lengths, referred to as kmers, exists to our knowledge. In this article, we present kmerDB, a database accessible through an interactive web interface that provides kmer-based information from genomic and proteomic sequences in a systematic way. kmerDB currently contains 202,340,859,107 base pairs and 19,304,903,356 amino acids, spanning 54,039 and 21,865 reference genomes and proteomes, respectively, as well as 6,905,362 and 149,305,183 genomic and proteomic species-specific sequences, termed quasi-primes. Additionally, we provide access to 5,186,757 nucleic and 214,904,089 peptide sequences absent from every genome and proteome, termed primes. kmerDB features a user-friendly interface offering various search options and filters for easy parsing and searching. The service is available at: www.kmerdb.com.

10.
Antioxid Redox Signal ; 38(7-9): 684-708, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36509429

RESUMO

Significance: The transcription factor NRF2 (NF-E2-related factor 2) plays an important role as a master regulator of the cellular defense system by activating transcriptional programs of NRF2 target genes encoding multiple enzymes related to cellular redox balance and xenobiotic detoxication. Comprehensive transcriptional analyses continue to reveal an ever-broadening range of NRF2 target genes, demonstrating the sophistication and diversification of NRF2 biological signatures beyond its canonical cytoprotective roles. Recent Advances: Accumulating evidence indicates that NRF2 has a strong association with the regulation of cell fates by influencing key processes of cellular transitions in the three major phases of the life cycle of the cell (i.e., cell birth, cell differentiation, and cell death). The molecular integration of NRF2 signaling into this regulatory program occurs through a wide range of NRF2 target genes encompassing canonical functions and those manipulating cell fate pathways. Critical Issues: A singular focus on NRF2 signaling for dissecting its actions limits in-depth understanding of its intersection with the molecular machinery of cell fate determinations. Compensatory responses of downstream pathways governed by NRF2 executed by a variety of transcription factors and multifactorial signaling crosstalk require further exploration. Future Directions: Further investigations using optimized in vivo models and active engagement of overarching approaches to probe the interplay of widespread pathways are needed to study the properties and capabilities of NRF2 signaling as a part of a large network within the cell fate regulatory domain. Antioxid. Redox Signal. 38, 684-708.


Assuntos
Regulação da Expressão Gênica , Fator 2 Relacionado a NF-E2 , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Diferenciação Celular/genética , Transdução de Sinais/fisiologia , Oxirredução , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo
12.
Free Radic Biol Med ; 190: 276-283, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35988853

RESUMO

The signaling pathway centered on the transcription factor nuclear erythroid factor 2-like 2 (Nrf2) has emerged during the last 15 years as a target for the prevention and treatment of diseases broadly related with oxidative stress such as cancer, neurodegenerative and metabolic diseases. The roles of Nrf2 are expanding beyond general cytoprotection, and they encompass its crosstalk with other pathways as well as tissue-specific functions. The thyroid gland relies on reactive oxygen species for its main physiological function, the synthesis and secretion of thyroid hormones. A few years ago, Nrf2 was characterized as a central regulator of the antioxidant response in the thyroid, as well as of the transcription and processing of thyroglobulin, the major thyroidal protein that serves as the substrate for thyroid hormone synthesis. Herein, we summarize the current knowledge about the roles of Nrf2 in thyroid physiology, pathophysiology and disease. We focus specifically on the most recent publications in the field, and we discuss the implications for the preclinical and clinical use of Nrf2 modulators.


Assuntos
Fator 2 Relacionado a NF-E2 , Glândula Tireoide , Antioxidantes/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Transdução de Sinais , Glândula Tireoide/metabolismo , Hormônios Tireóideos/genética , Hormônios Tireóideos/metabolismo
13.
BMJ Open ; 12(5): e057084, 2022 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-35589363

RESUMO

OBJECTIVES: Vaccination against SARS-CoV-2 has been extensively deployed during COVID-19 pandemic. One efficient method to evaluate response to vaccination is the assessment of humoral immunity by measuring SARS-CoV-2 antibody titres. We investigated the association between anthropometric parameters (age, body mass index), smoking, diabetes, statin use, hypertension, levels of 25(OH)D and dehydroepiandrosterone sulfate (DHEAS), and SARS-CoV-2 antibody titres after vaccination. DESIGN: In this longitudinal observational cohort study, 712 subjects were tested for SARS-CoV-2 antibodies 3 months after the second dose of BNT162b2 vaccine. Multiple linear regression analysis was performed to identify which factors are associated with the antibody titres. SETTING: Healthcare units of western Greece (University Hospital of Patras and "St Andrews" State General Hospital of Patras). PARTICIPANTS: All adults receiving their second dose of BNT162b2 vaccine at the participating healthcare units were eligible to participate in the study. Exclusion criteria were SARS-CoV-2 infection or positive SARS-CoV-2 antibody titre at baseline. Patients who did not provide all necessary information were excluded from our analyses. RESULTS: We found age to be negatively associated with antibody titre (-0.005; 95% CI -0.009 to -0.001, p=0.0073), as was male gender (-0.11; 95% CI -0.1738 to -0.04617, p=0.0008). The interaction of age and gender was significant (-0.01090; 95% CI -0.01631 to -0.005490, p<0.0001), highlighting that the rate of decline in antibody titre with increasing age tends to be higher in men rather than in women. No linear trend was found between DHEAS levels and antibody titres when the lower quartile of DHEAS levels was used as reference. Tobacco use was associated with low antibody titre (-0.1097; 95% CI -0.174 to -0.046, p=0.0008) but overweight, obese or underweight subjects had similar antibody responses to normal-weight individuals. Although subjects with diabetes and hypertension had numerically lower antibody titres, this association was not statistically significant. Vitamin D levels showed no clear relationships with antibody titres. CONCLUSIONS: Age, male gender and tobacco use are negatively associated with antibody titres after COVID-19 vaccination, but our data showed no clear correlation with vitamin D levels. TRIAL REGISTRATION NUMBER: NCT04954651; Results.


Assuntos
COVID-19 , Hipertensão , Adulto , Anticorpos Antivirais , Vacina BNT162 , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Feminino , Grécia/epidemiologia , Humanos , Estudos Longitudinais , Masculino , Pandemias/prevenção & controle , SARS-CoV-2 , Vacinação , Vitamina D
14.
Antioxidants (Basel) ; 11(11)2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36421460

RESUMO

BACKGROUND: Calorie restriction is known to enhance Nrf2 signaling and longevity in adult mice, partially by reducing reactive oxygen species, but calorie restriction during pregnancy leads to intrauterine growth retardation. The latter is associated with fetal reprogramming leading to increased incidence of obesity, metabolic syndrome and diabetes in adult life. Transcription factor Nrf2 is a central regulator of the antioxidant response and its crosstalk with metabolic pathways is emerging. We hypothesized that the Nrf2 pathway is induced in embryos during calorie restriction in pregnant mothers. METHODS: From gestational day 10 up to day 16, 50% of the necessary mouse diet was provided to Nrf2 heterozygous pregnant females with fathers being of the same genotype. Embryos were harvested at the end of gestational day 16 and fetal liver was used for qRT-PCR and assessment of oxidative stress (OS). RESULTS: Intrauterine calorie restriction led to upregulation of mRNA expression of antioxidant genes (Nqo1, Gsta1, Gsta4) and of genes related to integrated stress response (Chac1, Ddit3) in WT embryos. The expression of a key gluconeogenic (G6pase) and two lipogenic genes (Acacb, Fasn) was repressed in calorie-restricted embryos. In Nrf2 knockout embryos, the induction of Nqo1 and Gsta1 genes was abrogated while that of Gsta4 was preserved, indicating an at least partially Nrf2-dependent induction of antioxidant genes after in utero calorie restriction. Measures of OS showed no difference (superoxide radical and malondialdehyde) or a small decrease (thiobarbituric reactive substances) in calorie-restricted WT embryos. CONCLUSIONS: Calorie restriction during pregnancy elicits the transcriptional induction of cytoprotective/antioxidant genes in the fetal liver, which is at least partially Nrf2-dependent, with a physiological significance that warrants further investigation.

15.
Mol Med ; 17(7-8): 736-40, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21373720

RESUMO

Fibroblast growth factor-21 (FGF21) is a pleiotropic protein involved in glucose, lipid metabolism and energy homeostasis, with main tissues of expression being the liver and adipose tissue. Brown adipose tissue (BAT) is responsible for cold-induced thermogenesis in rodents. The role of FGF21 in BAT biology has not been investigated. In the present study, wild-type C57BL/6J mice as well as a brown adipocyte cell line were used to explore the potential role of cold exposure and ß3-adrenergic stimulation in the expression of FGF21 in BAT. Our results demonstrate that short-term exposure to cold, as well as ß3-adrenergic stimulation, causes a significant induction of FGF21 mRNA levels in BAT, without a concomitant increase in FGF21 plasma levels. This finding opens new routes for the potential use of pharmaceuticals that could induce FGF21 and, hence, activate BAT thermogenesis.


Assuntos
Tecido Adiposo Marrom/efeitos dos fármacos , Temperatura Baixa , Dioxóis/farmacologia , Fatores de Crescimento de Fibroblastos/genética , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Animais , Linhagem Celular Transformada , Fatores de Crescimento de Fibroblastos/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oxazóis/farmacologia , PPAR alfa/antagonistas & inibidores , PPAR alfa/genética , PPAR alfa/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores Adrenérgicos beta 3/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Termogênese/efeitos dos fármacos , Termogênese/genética , Transativadores/genética , Fatores de Transcrição , Ativação Transcricional/efeitos dos fármacos , Tirosina/análogos & derivados , Tirosina/farmacologia
16.
Antioxidants (Basel) ; 11(1)2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-35052508

RESUMO

Glucocorticoids are used widely on a long-term basis in autoimmune and inflammatory diseases. Their adverse effects include the development of hyperglycemia and osteoporosis, whose molecular mechanisms have been only partially studied in preclinical models. Both these glucocorticoid-induced pathologies have been shown to be mediated at least in part by oxidative stress. The transcription factor nuclear erythroid factor 2-like 2 (NRF2) is a central regulator of antioxidant and cytoprotective responses. Thus, we hypothesized that NRF2 may play a role in glucocorticoid-induced metabolic disease and osteoporosis. To this end, WT and Nrf2 knockout (Nrf2KO) mice of both genders were treated with 2 mg/kg dexamethasone or vehicle 3 times per week for 13 weeks. Dexamethasone treatment led to less weight gain during the treatment period without affecting food consumption, as well as to lower glucose levels and high insulin levels compared to vehicle-treated mice. Dexamethasone also reduced cortical bone volume and density. All these effects of dexamethasone were similar between male and female mice, as well as between WT and Nrf2KO mice. Hepatic NRF2 signaling and gluconeogenic gene expression were not affected by dexamethasone. A 2-day dexamethasone treatment was also sufficient to increase insulin levels without affecting body weight and glucose levels. Hence, dexamethasone induces hyperinsulinemia, which potentially leads to decreased glucose levels, as well as osteoporosis, both independently of NRF2.

17.
Thyroid ; 31(1): 23-35, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32689903

RESUMO

Background: Familial nontoxic multinodular goiter (MNG) is a rare disease. One of the associated genes is Kelch-like ECH-associated protein 1 (KEAP1), which encodes the main inhibitor of nuclear factor erythroid 2-related transcription factor 2 (Nrf2), a central mediator of antioxidant responses. The association of KEAP1 with familial MNG is based on only two loss-of-function mutations identified in two families, only one of which included proper phenotyping and adequate demonstration of co-segregation of the phenotype and the mutation. There is no experimental evidence from model organisms to support that decreased Keap1 levels can, indeed, cause goiter. This study used mice hypomorphic for Keap1 to test whether decreased Keap1 expression can cause goiter, and to characterize the activation status of Nrf2 in their thyroid. Methods: C57BL/6J Keap1flox/flox (Keap1 knock-down [Keap1KD]) mice were studied at 3 and 12 months of age. Plasma and thyroid glands were harvested for evaluation of thyroid function tests and for gene and protein expression by real-time polymerase chain reaction and immunoblotting, respectively. Results: Keap1KD mice showed diffuse goiter that began to develop in early adult life and became highly prominent and penetrant with age. The goiter was characterized by a markedly increased size of thyroid follicles, most notably of the colloid compartment, and by absence of thyroid nodules or hyperplasia. Keap1KD mice also showed decreased T4 levels in early adult life that were eventually well compensated over time by increased thyrotropin (TSH) levels. Nrf2 was activated in the thyroid of Keap1KD mice. Despite a known stimulatory effect of Nrf2 on thyroglobulin (Tg) gene transcription and Tg protein abundance, the expression levels were decreased in the thyroid of Keap1KD mice. No clear patterns were observed in the expression profiles of other thyroid hormone synthesis-specific factors, with the exception of Tg-processing and Tg-degrading cathepsins, including an increase in mature forms of cathepsins D, L, and S. Conclusions: Keap1KD mice develop age-dependent diffuse goiter with elevated TSH levels. The precise mechanism accounting for the thyroidal phenotype remains to be elucidated, but it may involve enhanced Tg solubilization and excessive lysosomal Tg degradation.


Assuntos
Bócio Nodular/genética , Proteína 1 Associada a ECH Semelhante a Kelch/deficiência , Fator 2 Relacionado a NF-E2/metabolismo , Glândula Tireoide/metabolismo , Tireotropina/sangue , Fatores Etários , Animais , Biomarcadores/sangue , Predisposição Genética para Doença , Bócio Nodular/sangue , Bócio Nodular/patologia , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo , Fenótipo , Tireoglobulina/metabolismo , Glândula Tireoide/patologia , Regulação para Cima
18.
Front Oncol ; 10: 499, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32318352

RESUMO

The epithelial-mesenchymal transition (EMT) represents a biological program during which epithelial cells lose their cell identity and acquire a mesenchymal phenotype. EMT is normally observed during organismal development, wound healing and tissue fibrosis. However, this process can be hijacked by cancer cells and is often associated with resistance to apoptosis, acquisition of tissue invasiveness, cancer stem cell characteristics, and cancer treatment resistance. It is becoming evident that EMT is a complex, multifactorial spectrum, often involving episodic, transient or partial events. Multiple factors have been causally implicated in EMT including transcription factors (e.g., SNAIL, TWIST, ZEB), epigenetic modifications, microRNAs (e.g., miR-200 family) and more recently, long non-coding RNAs. However, the relevance of metabolic pathways in EMT is only recently being recognized. Importantly, alterations in key metabolic pathways affect cancer development and progression. In this review, we report the roles of key EMT factors and describe their interactions and interconnectedness. We introduce metabolic pathways that are involved in EMT, including glycolysis, the TCA cycle, lipid and amino acid metabolism, and characterize the relationship between EMT factors and cancer metabolism. Finally, we present therapeutic opportunities involving EMT, with particular focus on cancer metabolic pathways.

19.
Antioxidants (Basel) ; 9(11)2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33158045

RESUMO

The thyroid gland has a special relationship with oxidative stress. On the one hand, like all other tissues, it must defend itself against reactive oxygen species (ROS). On the other hand, unlike most other tissues, it must also produce reactive oxygen species in order to synthesize its hormones that contribute to the homeostasis of other tissues. The thyroid must therefore also rely on antioxidant defense systems to maintain its own homeostasis in the face of continuous self-exposure to ROS. One of the main endogenous antioxidant systems is the pathway centered on the transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2) and its cytoplasmic inhibitor Kelch-like ECH-associated protein 1 (Keap1). Over the last few years, multiple links have emerged between the Keap1/Nrf2 pathway and thyroid physiology, as well as various thyroid pathologies, including autoimmunity, goiter, hypothyroidism, hyperthyroidism, and cancer. In the present mini-review, we summarize recent studies shedding new light into the roles of Keap1/Nrf2 signaling in the thyroid.

20.
Antioxidants (Basel) ; 9(11)2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33212784

RESUMO

Research on the antioxidant pathway comprising the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and its cytoplasmic inhibitor Kelch-like ECH-associated protein 1 (Keap1) is ever increasing. As modulators of this pathway have started to be used in clinical trials and clinical practice, Nrf2 has become the subject of several patents. To assess the patent landscape of the last three years on Nrf2 and evaluate the main fields they refer to, we used the web-based tool PatSeer Pro to identify patents mentioning the Nrf2 pathway between January 2017 and May 2020. This search resulted in 509 unique patents that focus on topics such as autoimmune, neurodegenerative, liver, kidney, and lung diseases and refer to modulators (mainly activators) of the Nrf2 pathway as potential treatments. Autoimmunity emerged as the main theme among the topics of Nrf2 patents, including a broad range of diseases, such as systemic sclerosis, systemic lupus erythematosus, multiple sclerosis, inflammatory bowel diseases, Hashimoto's thyroiditis, etc.; however, there was a dearth of experimental support for the respective patents' claims. Given that chronic inflammation is the main element of the pathophysiology of most autoimmune diseases, the majority of patents referring to activation of Nrf2 as a method to treat autoimmune diseases base their claims on the well-established anti-inflammatory role of Nrf2. In conclusion, there is strong interest in securing intellectual property rights relating to the potential use of Nrf2 pathway activators in a variety of diseases, and this trend parallels the rise in related research publications. However, in the case of autoimmunity, more research is warranted to support the potential beneficial effects of Nrf2 modulation in each disease.

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