ABSTRACT
Genistein is an isoflavone present in soybeans and is considered a bioactive compound due to its widely reported biological activity. We have previously shown that intraperitoneal genistein administration and diet supplementation activates the thermogenic program in rats and mice subcutaneous white adipose tissue (scWAT) under multiple environmental cues, including cold exposure and high-fat diet feeding. However, the mechanistic insights of this process were not previously unveiled. Uncoupling protein 1 (UCP1), a mitochondrial membrane polypeptide responsible for dissipating energy into heat, is considered the most relevant thermogenic marker; thus, we aimed to evaluate whether genistein regulates UCP1 transcription. Here we show that genistein administration to thermoneutral-housed mice leads to the appearance of beige adipocyte markers, including a sharp upregulation of UCP1 expression and protein abundance in scWAT. Reporter assays showed an increase in UCP1 promoter activity after genistein stimulation, and in silico analysis revealed the presence of estrogen (ERE) and cAMP (CRE) response elements as putative candidates of genistein activation. Mutation of the CRE but not the ERE reduced genistein-induced promoter activity by 51%. Additionally, in vitro and in vivo ChIP assays demonstrated the binding of CREB to the UCP1 promoter after acute genistein administration. Taken together, these data elucidate the mechanism of genistein-mediated UCP1 induction and confirm its potential applications in managing metabolic disorders.
Subject(s)
Adipocytes, Beige , Mice , Rats , Animals , Transcriptional Activation , Adipocytes, Beige/metabolism , Genistein/pharmacology , Uncoupling Protein 1/genetics , Uncoupling Protein 1/metabolism , Adipose Tissue, White/metabolism , Thermogenesis/genetics , Response Elements , Adipose Tissue, Brown/metabolismABSTRACT
Although uncoupling protein 1 (UCP1) is established as a major contributor to adipose thermogenesis, recent data have illustrated an important role for alternative pathways, particularly the futile creatine cycle (FCC). How these pathways co-exist in cells and tissues has not been explored. Beige cell adipogenesis occurs in vivo but has been difficult to model in vitro; here, we describe the development of a murine beige cell line that executes a robust respiratory response, including uncoupled respiration and the FCC. The key FCC enzyme, tissue-nonspecific alkaline phosphatase (TNAP), is localized almost exclusively to mitochondria in these cells. Surprisingly, single-cell cloning from this cell line shows that cells with the highest levels of UCP1 express little TNAP, and cells with the highest expression of TNAP express little UCP1. Immunofluorescence analysis of subcutaneous fat from cold-exposed mice confirms that the highest levels of these critical thermogenic components are expressed in distinct fat cell populations.
ABSTRACT
Ergothioneine (EGT) is a diet-derived, atypical amino acid that accumulates to high levels in human tissues. Reduced EGT levels have been linked to age-related disorders, including neurodegenerative and cardiovascular diseases, while EGT supplementation is protective in a broad range of disease and aging models in mice. Despite these promising data, the direct and physiologically relevant molecular target of EGT has remained elusive. Here we use a systematic approach to identify how mitochondria remodel their metabolome in response to exercise training. From this data, we find that EGT accumulates in muscle mitochondria upon exercise training. Proteome-wide thermal stability studies identify 3-mercaptopyruvate sulfurtransferase (MPST) as a direct molecular target of EGT; EGT binds to and activates MPST, thereby boosting mitochondrial respiration and exercise training performance in mice. Together, these data identify the first physiologically relevant EGT target and establish the EGT-MPST axis as a molecular mechanism for regulating mitochondrial function and exercise performance.
ABSTRACT
Adipose tissue can recruit catabolic adipocytes that utilize chemical energy to dissipate heat. This process occurs either by uncoupled respiration through uncoupling protein 1 (UCP1) or by utilizing ATP-dependent futile cycles (FCs). However, it remains unclear how these pathways coexist since both processes rely on the mitochondrial membrane potential. Utilizing single-nucleus RNA sequencing to deconvolute the heterogeneity of subcutaneous adipose tissue in mice and humans, we identify at least 2 distinct subpopulations of beige adipocytes: FC-adipocytes and UCP1-beige adipocytes. Importantly, we demonstrate that the FC-adipocyte subpopulation is highly metabolically active and utilizes FCs to dissipate energy, thus contributing to thermogenesis independent of Ucp1. Furthermore, FC-adipocytes are important drivers of systemic energy homeostasis and linked to glucose metabolism and obesity resistance in humans. Taken together, our findings identify a noncanonical thermogenic adipocyte subpopulation, which could be an important regulator of energy homeostasis in mammals.
ABSTRACT
SCOPE: Genistein increases whole body energy expenditure by stimulating white adipose tissue (WAT) browning and thermogenesis. G-Coupled receptor GPR30 can mediate some actions of genistein, however, it is not known whether it is involved in the activation of WAT-thermogenesis. Thus, the aim of the study is to determine whether genistein activates thermogenesis coupled to an increase in WAT browning and mitochondrial activity, in GPR30+/+ and GPR30-/- mice. METHODS AND RESULTS: GPR30+/+ and GPR30-/- mice are fed control or high fat sucrose diets containing or not genistein for 8 weeks. Body weight and composition, energy expenditure, glucose tolerance, and browning markers in WAT, and oxygen consumption rate, 3', 5'-cyclic adenosine monophosphate (cAMP) concentration and browning markers in adipocytes are evaluated. Genistein consumption reduces body weight and fat mass gain in a different extent in both genotypes, however, energy expenditure is lower in GPR30-/- compared to GPR30+/+ mice, accompanied by a reduction in browning markers, maximal mitochondrial respiration, cAMP concentration, and browning markers in cultured adipocytes from GPR30-/- mice. Genistein improves glucose tolerance in GPR30+/+ , but this is partially observed in GPR30-/- mice. CONCLUSION: The results show that GPR30 partially mediates genistein stimulation of WAT thermogenesis and the improvement of glucose tolerance.
Subject(s)
Adipose Tissue, Brown , Genistein , Adipose Tissue, Brown/metabolism , Adipose Tissue, White/metabolism , Animals , Body Weight , Energy Metabolism , Genistein/metabolism , Genistein/pharmacology , Glucose/metabolism , Mice , Mice, Inbred C57BL , Thermogenesis/geneticsABSTRACT
Introduction: Obesity has been associated with an increased risk of biologically aggressive variants in breast cancer. Women with obesity often have tumors diagnosed at later stages of the disease, associated with a poorer prognosis and a different response to treatment. Human cell lines have been derived from specific subtypes of breast cancer and have served to define the cell physiology of corresponding breast cancer subtypes. However, there are no current cell lines for breast cancer specifically derived from patients with different BMIs. The availability of those breast cancer cell lines should allow to describe and unravel functional alterations linked to these comorbidities. Methods: Cell cultures were established from tumor explants. Once generated, the triple negative subtype in a patient with obesity and a patient with a normal BMI were chosen for comparison. For cellular characterization, the following assays were conducted: proliferation assays, chemo - sensitivity assays for doxorubicin and paclitaxel, wound healing motility assays, matrix invasion assays, breast cancer cell growth to estradiol by chronic exposure to leptin, induction of endothelial permeability and tumorigenic potential in athymic mice with normo - versus hypercaloric diets with an evaluation of the epithelium - mesenchymal transformation proteins. Results: Two different cell lines, were established from patients with breast cancer: DSG-BC1, with a BMI of 21.9 kg/m2 and DSG-BC2, with a BMI of 31.5 kg/m2. In vitro, these two cell lines show differential growth rates, motility, chemosensitivity, vascular permeability, response to leptin with an activation of the JAK2/STAT3/AKT signaling pathway. In vivo, they displayed distinct tumorigenic potential. In particular, DSG-BC2, presented higher tumorigenicity when implanted in mice fed with a hypercaloric diet. Discussion: To our knowledge, these primary cultures are the first in vitro representation of both breast cancer and obesity. DSG - BC2 presented a more aggressive in vivo and in vitro phenotype. These results support the hypothesis that breast cancer generated in an obese metabolic state may represent a contrasting variant within the same disease. This new model will allow both further comprehension, functional studies and the analysis of altered molecular mechanisms under the comorbidity of obesity and breast cancer.
ABSTRACT
INTRODUCTION: Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). Compared with adults, children with SARS-CoV-2 infection may have fewer and less severe symptoms. Gastrointestinal symptoms are commonly reported in children, sometimes as the only manifestation of the disease, and most often manifest as anorexia, diarrhea, nausea and vomiting, or abdominal pain. Although most children have asymptomatic or mild disease, 10 % of those infected may experience serious or critical disease, or even death. Multisystem inflammatory syndrome is a rare but serious condition recently reported in children with COVID-19. Studies indicate that children with obesity are at higher risk of developing severe COVID-19, and inflammation associated with obesity could be one of the factors that worsens COVID-19 symptoms due to an increased inflammatory response involving molecules such as interleukin 6, tumor necrosis factor alpha, and monocyte chemoattractant protein. On the other hand, evidence has been reported of a higher protein expression of ACE2 in the visceral adipose tissue of obese and malnourished humans, and this could be associated with complications and severity of COVID-19. Therefore, regulation of the intake of macronutrients or micronutrients could be used as a strategy to reduce the consequences of COVID-19. Diet in general and bioactive compounds could play an important role in the prevention of the inflammatory cascade. The micronutrients with the most evidence suggesting a role in immune support are vitamins C and D, zinc, and polyphenols.
INTRODUCCIÓN: La enfermedad por coronavirus 2019 (COVID-19) está causada por el virus "síndrome respiratorio agudo severo-coronavirus 2" (SARS-CoV-2). En comparación con los adultos, los niños con infección por SARS-CoV-2 pueden tener menos síntomas y estos pueden ser menos graves. Los síntomas gastrointestinales se informan comúnmente en los niños, a veces como única manifestación de la enfermedad. Los más comunes son anorexia, diarrea, náuseas y vómitos, y dolor abdominal. Aunque la mayoría de los niños tienen un cuadro leve o asintomático, el 10 % de los infectados pueden experimentar un cuadro grave o crítico, e incluso la muerte. El síndrome inflamatorio multisistémico es una afección poco común, pero grave, que se documentó recientemente en niños con COVID-19. Los estudios indican que los niños con obesidad tienen mayor riesgo de desarrollar COVID-19 grave, y la inflamación asociada con la obesidad podría ser uno de los factores que empeoran los síntomas de la COVID-19 debido a una respuesta inflamatoria aumentada en donde se ven involucradas moléculas como la interleucina 6, el factor de necrosis tumoral alfa y la proteína quimioatrayente de monocitos. Por otro lado, se ha encontrado evidencia de una mayor expresión proteica de ACE2 en el tejido adiposo visceral de los seres humanos obesos y desnutridos, y esto podría estar asociado a las complicaciones y la severidad de la COVID-19. Por tanto, la regulación de la ingesta de macronutrientes o micronutrientes podría utilizarse como estrategia para reducir las consecuencias de la enfermedad. La dieta en general y los compuestos bioactivos podrían desempeñar un papel importante en la prevención de la cascada inflamatoria. Los micronutrientes con mayor evidencia indicativa de que desempeñan un papel en el apoyo inmunológico son las vitaminas C y D, el zinc y los polifenoles.
Subject(s)
COVID-19/complications , Gastrointestinal Diseases/etiology , Pediatric Obesity/complications , Abdominal Pain/etiology , Angiotensin-Converting Enzyme 2/metabolism , Anorexia/etiology , Ascorbic Acid/administration & dosage , COVID-19/etiology , COVID-19/metabolism , Child , Diarrhea/etiology , Female , Humans , Inflammation/complications , Male , Nausea/etiology , Overweight/complications , Oxidative Stress , Pediatric Obesity/metabolism , Polyphenols/administration & dosage , Systemic Inflammatory Response Syndrome/etiology , Thinness/complications , Thinness/metabolism , Vitamin D/administration & dosage , Vitamins/administration & dosage , Vomiting/etiology , Zinc/administration & dosage , Zinc/deficiencyABSTRACT
The increase in incidence and prevalence of metabolic diseases, such as diabetes, obesity, and metabolic syndrome, is a health problem worldwide. Nutritional strategies that can impact on mitochondrial activity represent a novel and effective option to modulate energy expenditure and energetic metabolism in cells and tissues and could be used as adjuvant treatments for metabolic-associated disorders. Dietary bioactive compounds also known as "food bioactives" have proven to exert multiple health benefits and counteract metabolic alterations. In the last years, it has been consistently reported that the modulation of mitochondrial function represents one of the mechanisms behind the bioactive compounds-dependent health improvements. In this review, we focus on gathering, summarizing, and discussing the evidence that supports the effect of dietary bioactive compounds on mitochondrial activity and the relation of these effects in the pathological context. Despite the evidence presented here on in vivo and in vitro effects, more studies are needed to determine their effectiveness in humans.
Subject(s)
Functional Food , Mitochondria/metabolism , AMP-Activated Protein Kinases/metabolism , Animals , Functional Food/analysis , Gastrointestinal Microbiome , Humans , Mitochondria/pathology , Oxygen Consumption , Sirtuin 1/metabolism , ThermogenesisABSTRACT
The preservation of body proteins is essential to guarantee their functions in organisms. Therefore, the utilization of amino acids as energy substrates is regulated by a precise fine-tuned mechanism. Recent evidence suggests that the transcription factors peroxisome proliferator-activated receptor alpha (PPARα) and hepatocyte nuclear factor 4 alpha (HNF4α) are involved in this regulatory mechanism. Thus, the aim of this study was to determine how these transcription factors interact to regulate the expression of amino acid catabolism genes. In vivo studies using PPARα-knockout mice (Pparα-null) fed different amounts of dietary protein showed that in the absence of PPARα, there was a significant increase in HNF4α abundance in the liver, which corresponded with an increase in amino acid catabolizing enzyme (AACE) expression and the generation of increased amounts of postprandial urea. Moreover, this effect was proportional to the increase in dietary protein consumed. Chromatin immunoprecipitation assays showed that HNF4α can bind to the promoter of AACE serine dehydratase (SDS), an effect that was potentiated by dietary protein in the Pparα-null mice. The mechanistic studies revealed that the presence of retinoid X receptor alpha (RXRα) is essential to repress HNF4α activity in the presence of PPARα, and this interaction accelerates HNF4α degradation via the proteasome pathway. These results showed that PPARα can downregulate liver amino acid catabolism in the presence of RXRα by inhibiting HNF4α activity.
Subject(s)
Amino Acids/metabolism , Hepatocyte Nuclear Factor 4/metabolism , Liver/metabolism , PPAR alpha/physiology , Retinoid X Receptor alpha/physiology , Animals , Down-Regulation/genetics , HEK293 Cells , Hep G2 Cells , Humans , Male , Metabolism/genetics , Mice , Mice, Inbred C57BL , Mice, Knockout , PPAR alpha/genetics , Proteasome Endopeptidase Complex/metabolism , Protein Binding , Proteolysis , Retinoid X Receptor alpha/geneticsABSTRACT
The malignant energetic demands are satisfied through glycolysis, glutaminolysis and de novo synthesis of fatty acids, while the host curses with a state of catabolism and systemic inflammation. The concurrent inhibition of both, tumor anabolism and host catabolism, and their effect upon tumor growth and whole animal metabolism, have not been evaluated. We aimed to evaluate in colon cancer cells a combination of six agents directed to block the tumor anabolism (orlistat + lonidamine + DON) and the host catabolism (growth hormone + insulin + indomethacin). Treatment reduced cellular viability, clonogenic capacity and cell cycle progression. These effects were associated with decreased glycolysis and oxidative phosphorylation, leading to a quiescent energetic phenotype, and with an aberrant transcriptomic landscape showing dysregulation in multiple metabolic pathways. The in vivo evaluation revealed a significant tumor volume inhibition, without damage to normal tissues. The six-drug combination preserved lean tissue and decreased fat loss, while the energy expenditure got decreased. Finally, a reduction in gene expression associated with thermogenesis was observed. Our findings demonstrate that the simultaneous use of this six-drug combination has anticancer effects by inducing a quiescent energetic phenotype of cultured cancer cells. Besides, the treatment is well-tolerated in mice and reduces whole animal energetic expenditure and fat loss.
Subject(s)
Cell Survival/drug effects , Colonic Neoplasms/drug therapy , Energy Metabolism/drug effects , Metabolic Networks and Pathways/drug effects , Animals , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Cell Line, Tumor , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Daunorubicin/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Glycolysis/drug effects , Growth Hormone/pharmacology , Humans , Indazoles/pharmacology , Indomethacin/pharmacology , Insulin/pharmacology , Metabolism/drug effects , Mice , Mitoxantrone/pharmacology , Orlistat/pharmacology , Oxidative Phosphorylation/drug effects , Vincristine/pharmacologyABSTRACT
SCOPE: Soy protein is a high-quality protein and its consumption has been associated with a reduction of serum cholesterol and triglycerides and an improvement in insulin resistance. However, it is not known whether the effects of soy protein are mediated by the gut microbiota. Thus, the aim of this study is to assess whether using antibiotics to partially eradicate the gut microbiota can prevent the beneficial effects of soy protein in rats. METHODS AND RESULTS: Thus, rats are fed one of the following diets for 16 weeks: casein control, soy protein control, high-fat casein, and high-fat soy protein. The rats are then treated for 4 weeks with antibiotics. Body weight and composition, energy expenditure, glucose tolerance test, metabolic endotoxemia, and gut microbiota are measured before and after treatment with antibiotic. The results show that soy protein consumption decreases weight gain, body fat, metabolic endotoxemia, and increases energy expenditure and glucose tolerance. Antibiotic treatment suppresses all these metabolic effects. These changes are accompanied by modifying the diversity and taxonomy of the gut microbiota. CONCLUSION: In conclusion, the evidence suggests that the health benefits of soy protein are partly dependent of the gut microbiota.
Subject(s)
Anti-Bacterial Agents/pharmacology , Gastrointestinal Microbiome/drug effects , Soybean Proteins/pharmacology , Adipose Tissue/drug effects , Ampicillin/adverse effects , Ampicillin/pharmacology , Animals , Anti-Bacterial Agents/adverse effects , Biomarkers/metabolism , Body Composition/drug effects , Caseins/pharmacology , Diet, High-Fat/adverse effects , Endotoxemia/chemically induced , Energy Metabolism/drug effects , Fatty Acids, Volatile/metabolism , Gastrointestinal Microbiome/physiology , Inflammation/genetics , Inflammation/metabolism , Male , Neomycin/adverse effects , Neomycin/pharmacology , Rats, Wistar , Weight Gain/drug effectsABSTRACT
OBJECTIVE: Angiotensin-(1-7) [Ang-(1-7)], a component of the renin angiotensin system, is a vasodilator that exerts its effects primarily through the Mas receptor. The discovery of the Mas receptor in white adipose tissue (WAT) suggests an additional role for this peptide. The aim of the present study was to assess whether Ang-(1-7) can induce the expression of thermogenic genes in white adipose tissue and increase mitochondrial respiration in adipocytes. MATERIALS/METHODS: Stromal Vascular fraction (SVF)-derived from mice adipose tissue was stimulated for one week with Ang-(1-7), then expression of beige markers and mitochondrial respiration were assessed. Mas+/+ and Mas-/- mice fed a control diet or a high fat-sucrose diet (HFSD) were exposed to a short or long term infusion of Ang-(1-7) and body weight, body fat, energy expenditure, cold resistance and expression of beige markers were assessed. Also, transgenic rats overexpressing Ang-(1-7) were fed with a control diet or a high fat-sucrose diet and the same parameters were assessed. Ang-(1-7) circulating levels from human subjects with different body mass index (BMI) or age were measured. RESULTS: Incubation of adipocytes derived from SVF with Ang-(1-7) increased the expression of beige markers. Infusion of Ang-(1-7) into lean and obese Mas+/+mice also induced the expression of Ucp1 and some beige markers, an effect not observed in Mas-/- mice. Mas-/- mice had increased body weight gain and decreased cold resistance, whereas rats overexpressing Ang-(1-7) showed the opposite effects. Overexpressing rats exposed to cold developed new thermogenic WAT in the anterior interscapular area. Finally, in human subjects the higher the BMI, low circulating concentration of Ang-(1-7) levels were detected. Similarly, the circulating levels of Ang-(1-7) peptide were reduced with age. CONCLUSION: These data indicate that Ang-(1-7) stimulates beige markers and thermogenesis via the Mas receptor, and this evidence suggests a potential therapeutic use to induce thermogenesis of WAT, particularly in obese subjects that have reduced circulating concentration of Ang-(1-7).
Subject(s)
Adipose Tissue, Beige/drug effects , Angiotensin I/pharmacology , Peptide Fragments/pharmacology , Proto-Oncogene Proteins/physiology , Receptors, G-Protein-Coupled/physiology , Thermogenesis/drug effects , Adipose Tissue, Beige/metabolism , Adipose Tissue, White/drug effects , Adipose Tissue, White/metabolism , Adult , Animals , Cell Respiration/drug effects , Cell Respiration/genetics , Cells, Cultured , Energy Metabolism/genetics , Female , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Middle Aged , Obesity/genetics , Obesity/metabolism , Obesity/pathology , Proto-Oncogene Mas , Proto-Oncogene Proteins/genetics , Rats , Rats, Transgenic , Receptors, G-Protein-Coupled/genetics , Thermogenesis/genetics , Young AdultABSTRACT
OBJECTIVE: Obesity is associated with metabolic abnormalities, including insulin resistance and dyslipidemias. Previous studies demonstrated that genistein intake modifies the gut microbiota in mice by selectively increasing Akkermansia muciniphila, leading to reduction of metabolic endotoxemia and insulin sensitivity. However, it is not known whether the consumption of genistein in humans with obesity could modify the gut microbiota reducing the metabolic endotoxemia and insulin sensitivity. RESEARCH DESIGN AND METHODS: 45 participants with a Homeostatic Model Assessment (HOMA) index greater than 2.5 and body mass indices of ≥30 and≤40 kg/m2 were studied. Patients were randomly distributed to consume (1) placebo treatment or (2) genistein capsules (50 mg/day) for 2 months. Blood samples were taken to evaluate glucose concentration, lipid profile and serum insulin. Insulin resistance was determined by means of the HOMA for insulin resistance (HOMA-IR) index and by an oral glucose tolerance test. After 2 months, the same variables were assessed including a serum metabolomic analysis, gut microbiota, and a skeletal muscle biopsy was obtained to study the gene expression of fatty acid oxidation. RESULTS: In the present study, we show that the consumption of genistein for 2 months reduced insulin resistance in subjects with obesity, accompanied by a modification of the gut microbiota taxonomy, particularly by an increase in the Verrucomicrobia phylum. In addition, subjects showed a reduction in metabolic endotoxemia and an increase in 5'-adenosine monophosphate-activated protein kinase phosphorylation and expression of genes involved in fatty acid oxidation in skeletal muscle. As a result, there was an increase in circulating metabolites of ß-oxidation and ω-oxidation, acyl-carnitines and ketone bodies. CONCLUSIONS: Change in the gut microbiota was accompanied by an improvement in insulin resistance and an increase in skeletal muscle fatty acid oxidation. Therefore, genistein could be used as a part of dietary strategies to control the abnormalities associated with obesity, particularly insulin resistance; however, long-term studies are needed.
Subject(s)
AMP-Activated Protein Kinases/metabolism , Anti-Obesity Agents/administration & dosage , Gastrointestinal Microbiome/drug effects , Genistein/administration & dosage , Insulin Resistance , Muscle, Skeletal/drug effects , Obesity/metabolism , Obesity/microbiology , Double-Blind Method , Fatty Acids/metabolism , Humans , Muscle, Skeletal/metabolismABSTRACT
White adipose tissue (WAT) can differentiate into beige adipose tissue by the browning process. Some polyphenols, including isoflavones, particularly genistein, are suggested to increase the expression of browning markers. There is evidence that consumption of genistein can attenuate body weight gain and improve glucose tolerance and blood lipid levels. The aim of the present study was to investigate the potential mechanisms of stimulation by which genistein activates the browning of WAT. We studied the stimulation of the expression of browning markers in the following models: mice fed genistein; preadipocytes from 3 T3-L1 cells; and the stromal vascular fraction (SVF) from the inguinal adipose tissue of mice. The results indicated that genistein can stimulate the browning process by at least two mechanisms. An indirect mechanism was involved in the induction of PGC-1α/FNDC5 in skeletal muscle leading to an increase in the myokine irisin. In preadipocytes, irisin was able to increase the expression of Ucp1 and Tmem26, markers of browning, to increase energy expenditure. Interestingly, genistein was also able to activate browning by a direct mechanism. Incubation of preadipocytes with genistein increased UCP1 expression as well as some biomarkers of browning in a concentration-dependent manner, possibly via phosphorylation of AMPK. The effect of genistein was accompanied by an increase in the number of mitochondria as well as in the maximum respiration rate of the adipocytes. In conclusion, this study indicated that genistein can increase energy expenditure by stimulating the browning process directly in preadipocytes and indirectly by increasing the circulating levels of irisin.
Subject(s)
Adipose Tissue, White/drug effects , Adipose Tissue, White/metabolism , Energy Metabolism/drug effects , Genistein/pharmacology , 3T3-L1 Cells , AMP-Activated Protein Kinases/metabolism , Adipose Tissue, Beige/drug effects , Animals , Cell Differentiation/drug effects , Fibronectins/metabolism , Gene Expression Regulation/drug effects , Glucose/metabolism , Male , Mice , Mice, Inbred C57BL , Thermogenesis/drug effectsABSTRACT
Obesity is characterized by an excess of white adipose tissue (WAT). Recent evidence has demonstrated that WAT can change its phenotype to a brown-like adipose tissue known as beige/brite adipose tissue. This transition is characterized by an increase in thermogenic capacity mediated by uncoupling protein 1 (UCP1). This browning process is a potential new target for treating obesity. The aim of this review is to integrate the different mechanisms by which beige/brite adipocytes are formed and to describe the physiological, pharmacological and nutritional inducers that can promote browning. An additional aim is to show evidence of how some of these inducers can be used as potential therapeutic agents against obesity and its comorbidities. This review shows the importance of brown and beige/brite adipose tissue and the mechanisms of their formation. Particularly, the two theories of beige/brite adipocyte origin are discussed: de novo differentiation and transdifferentiation. The gene markers that identify these types of adipocytes and the involvement of microRNAs in the epigenetic regulation of the browning process is also discussed. Additionally, we describe the transcriptional control of UCP1 expression by some of the inducers of browning. Furthermore, we describe in detail how some bioactive dietary compounds can induce browning and their subsequent beneficial health effects. The evidence suggests that browning is a new potential strategy for the treatment of obesity and obesity-associated metabolic disorders.
Subject(s)
Adipose Tissue, Brown/pathology , Adipose Tissue, White/pathology , Obesity/pathology , Thermogenesis , Adipocytes/metabolism , Adipocytes/pathology , Adipose Tissue, Brown/metabolism , Adipose Tissue, White/metabolism , Animals , Cell Differentiation , Cell Transdifferentiation , Diet , Epigenesis, Genetic , Gene Expression Regulation , Humans , MicroRNAs/metabolism , Obesity/genetics , Obesity/physiopathology , Uncoupling Protein 1/genetics , Uncoupling Protein 1/metabolismABSTRACT
Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). Compared with adults, children with SARS-CoV-2 infection may have fewer and less severe symptoms. Gastrointestinal symptoms are commonly reported in children, sometimes as the only manifestation of the disease, and most often manifest as anorexia, diarrhea, nausea and vomiting, or abdominal pain. Although most children have asymptomatic or mild disease, 10 % of those infected may experience serious or critical disease, or even death. Multisystem inflammatory syndrome is a rare but serious condition recently reported in children with COVID-19. Studies indicate that children with obesity are at higher risk of developing severe COVID-19, and inflammation associated with obesity could be one of the factors that worsens COVID-19 symptoms due to an increased inflammatory response involving molecules such as interleukin 6, tumor necrosis factor alpha, and monocyte chemoattractant protein. On the other hand, evidence has been reported of a higher protein expression of ACE2 in the visceral adipose tissue of obese and malnourished humans, and this could be associated with complications and severity of COVID-19. Therefore, regulation of the intake of macronutrients or micronutrients could be used as a strategy to reduce the consequences of COVID-19. Diet in general and bioactive compounds could play an important role in the prevention of the inflammatory cascade. The micronutrients with the most evidence suggesting a role in immune support are vitamins C and D, zinc, and polyphenols. (AU)
La enfermedad por coronavirus 2019 (COVID-19) está causada por el virus "síndrome respiratorio agudo severo-coronavirus 2" (SARS-CoV-2). En comparación con los adultos, los niños con infección por SARS-CoV-2 pueden tener menos síntomas y estos pueden ser menos graves. Los síntomas gastrointestinales se informan comúnmente en los niños, a veces como única manifestación de la enfermedad. Los más comunes son anorexia, diarrea, náuseas y vómitos, y dolor abdominal. Aunque la mayoría de los niños tienen un cuadro leve o asintomático, el 10 % de los infectados pueden experimentar un cuadro grave o crítico, e incluso la muerte. El síndrome inflamatorio multisistémico es una afección poco común, pero grave, que se documentó recientemente en niños con COVID-19. Los estudios indican que los niños con obesidad tienen mayor riesgo de desarrollar COVID-19 grave, y la inflamación asociada con la obesidad podría ser uno de los factores que empeoran los síntomas de la COVID-19 debido a una respuesta inflamatoria aumentada en donde se ven involucradas moléculas como la interleucina 6, el factor de necrosis tumoral alfa y la proteína quimioatrayente de monocitos. Por otro lado, se ha encontrado evidencia de una mayor expresión proteica de ACE2 en el tejido adiposo visceral de los seres humanos obesos y desnutridos, y esto podría estar asociado a las complicaciones y la severidad de la COVID-19. Por tanto, la regulación de la ingesta de macronutrientes o micronutrientes podría utilizarse como estrategia para reducir las consecuencias de la enfermedad. La dieta en general y los compuestos bioactivos podrían desempeñar un papel importante en la prevención de la cascada inflamatoria. Los micronutrientes con mayor evidencia indicativa de que desempeñan un papel en el apoyo inmunológico son las vitaminas C y D, el zinc y los polifenoles. (AU)