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1.
Int J Mol Sci ; 22(10)2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34065474

RESUMO

Obesity-induced adipose tissue dysfunction and disorders of glycolipid metabolism have become a worldwide research priority. Zfp217 plays a crucial role in adipogenesis of 3T3-L1 preadipocytes, but about its functions in animal models are not yet clear. To explore the role of Zfp217 in high-fat diet (HFD)-induced obese mice, global Zfp217 heterozygous knockout (Zfp217+/-) mice were constructed. Zfp217+/- mice and Zfp217+/+ mice fed a normal chow diet (NC) did not differ significantly in weight gain, percent body fat mass, glucose tolerance, or insulin sensitivity. When challenged with HFD, Zfp217+/- mice had less weight gain than Zfp217+/+ mice. Histological observations revealed that Zfp217+/- mice fed a high-fat diet had much smaller white adipocytes in inguinal white adipose tissue (iWAT). Zfp217+/- mice had improved metabolic profiles, including improved glucose tolerance, enhanced insulin sensitivity, and increased energy expenditure compared to the Zfp217+/+ mice under HFD. We found that adipogenesis-related genes were increased and metabolic thermogenesis-related genes were decreased in the iWAT of HFD-fed Zfp217+/+ mice compared to Zfp217+/- mice. In addition, adipogenesis was markedly reduced in mouse embryonic fibroblasts (MEFs) from Zfp217-deleted mice. Together, these data indicate that Zfp217 is a regulator of energy metabolism and it is likely to provide novel insight into treatment for obesity.


Assuntos
Metabolismo Energético/fisiologia , Obesidade/metabolismo , Obesidade/fisiopatologia , Transativadores/metabolismo , Adipócitos Brancos/metabolismo , Adipócitos Brancos/fisiologia , Adipogenia/fisiologia , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/fisiopatologia , Animais , Dieta Hiperlipídica , Fibroblastos/metabolismo , Fibroblastos/fisiologia , Resistência à Insulina/fisiologia , Metabolismo dos Lipídeos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Obesos , Termogênese/fisiologia , Ganho de Peso/fisiologia
2.
Int J Mol Sci ; 22(10)2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-34063487

RESUMO

Conflicting reports exist with regard to the effect of ecdysterone, the predominating representative of steroid hormones in insects and plants, on hepatic and plasma lipid concentrations in different rodent models of obesity, fatty liver, and diabetes, indicating that the effect is dependent on the rodent model used. Here, the hypothesis was tested for the first time that ecdysterone causes lipid-lowering effects in genetically obese Zucker rats. To test this hypothesis, two groups of male obese Zucker rats (n = 8) were fed a nutrient-adequate diet supplemented without or with 0.5 g ecdysterone per kg diet. To study further if ecdysterone is capable of alleviating the strong lipid-synthetic activity in the liver of obese Zucker rats, the study included also two groups of male lean Zucker rats (n = 8) which also received either the ecdysterone-supplemented or the non-supplemented diet. While hepatic and plasma concentrations of triglycerides and cholesterol were markedly higher in the obese compared to the lean rats (p < 0.05), hepatic and plasma triglyceride and cholesterol concentrations did not differ between rats of the same genotype fed the diets without or with ecdysterone. In conclusion, the present study clearly shows that ecdysterone supplementation does not exhibit lipid-lowering actions in the liver and plasma of lean and obese Zucker rats.


Assuntos
Ecdisterona/metabolismo , Ecdisterona/farmacologia , Metabolismo dos Lipídeos/fisiologia , Fígado/efeitos dos fármacos , Obesidade/metabolismo , Animais , Suplementos Nutricionais , Frutosamina/sangue , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Genótipo , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipídeos/sangue , Fígado/metabolismo , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos Zucker , Reprodutibilidade dos Testes
3.
Int J Mol Sci ; 22(11)2021 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-34067450

RESUMO

The endocannabinoid system (ECS) consists of endogenous cannabinoids, their receptors, and metabolic enzymes that play a critical homeostatic role in modulating polyunsaturated omega fatty acid (PUFA) signaling to maintain a balanced inflammatory and redox state. Whole food-based diets and dietary interventions linked to PUFAs of animal (fish, calamari, krill) or plant (hemp, flax, walnut, algae) origin, as well as full-spectrum hemp oils, are increasingly used to support the ECS tone, promote healthy metabolism, improve risk factors associated with cardiovascular disorders, encourage brain health and emotional well-being, and ameliorate inflammation. While hemp cannabinoids of THC and CBD groups show distinct but complementary actions through a variety of cannabinoid (CB1 and CB2), adenosine (A2A), and vanilloid (TRPV1) receptors, they also modulate PUFA metabolism within a wide variety of specialized lipid mediators that promote or resolve inflammation and oxidative stress. Clinical evidence reviewed in this study links PUFAs and cannabinoids to changes in ECS tone, immune function, metabolic and oxidative stress adaptation, and overall maintenance of a well-balanced systemic function of the body. Understanding how the body coordinates signals from the exogenous and endogenous ECS modulators is critical for discerning the underlying molecular mechanisms of the ECS tone in healthy and disease states. Nutritional and lifestyle interventions represent promising approaches to address chronic metabolic and inflammatory disorders that may overlap in the population at risk. Further investigation and validation of dietary interventions that modulate the ECS are required in order to devise clinically successful second-generation management strategies.


Assuntos
Cannabis/metabolismo , Endocanabinoides/metabolismo , Ácidos Graxos Insaturados/metabolismo , Extratos Vegetais/metabolismo , Adenosina/metabolismo , Animais , Canabinoides/metabolismo , Dieta , Homeostase/fisiologia , Humanos , Inflamação/metabolismo , Metabolismo dos Lipídeos/fisiologia , Estresse Oxidativo/fisiologia , Transdução de Sinais/fisiologia , Canais de Cátion TRPV/metabolismo
4.
Int J Mol Sci ; 22(10)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34069902

RESUMO

Hepatocellular carcinoma (HCC) still remains a difficult to cure malignancy. In recent years, the focus has shifted to lipid metabolism for the treatment of HCC. Very little is known about hepatitis B virus (HBV) and C virus (HCV)-related hepatic lipid disturbances in non-malignant and cancer tissues. The present study showed that triacylglycerol and cholesterol concentrations were similar in tumor adjacent HBV and HCV liver, and were not induced in the HCC tissues. Higher levels of free cholesterol, polyunsaturated phospholipids and diacylglycerol species were noted in non-tumorous HBV compared to HCV liver. Moreover, polyunsaturated phospholipids and diacylglycerols, and ceramides declined in tumors of HBV infected patients. All of these lipids remained unchanged in HCV-related HCC. In HCV tumors, polyunsaturated phosphatidylinositol levels were even induced. There were no associations of these lipid classes in non-tumor tissues with hepatic inflammation and fibrosis scores. Moreover, these lipids did not correlate with tumor grade or T-stage in HCC tissues. Lipid reprogramming of the three analysed HBV/HCV related tumors mostly resembled HBV-HCC. Indeed, lipid composition of non-tumorous HCV tissue, HCV tumors, HBV tumors and HBV/HCV tumors was highly similar. The tumor suppressor protein p53 regulates lipid metabolism. The p53 and p53S392 protein levels were induced in the tumors of HBV, HCV and double infected patients, and this was significant in HBV infection. Negative correlation of tumor p53 protein with free cholesterol indicates a role of p53 in cholesterol metabolism. In summary, the current study suggests that therapeutic strategies to target lipid metabolism in chronic viral hepatitis and associated cancers have to consider disease etiology.


Assuntos
Carcinoma Hepatocelular/metabolismo , Colesterol/metabolismo , Fígado/metabolismo , Adulto , Idoso , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/genética , Colesterol/fisiologia , Feminino , Alemanha/epidemiologia , Hepacivirus/metabolismo , Hepatite B/virologia , Vírus da Hepatite B/metabolismo , Hepatite C/virologia , Humanos , Metabolismo dos Lipídeos/fisiologia , Lipídeos/fisiologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Masculino , Pessoa de Meia-Idade
5.
Int J Mol Sci ; 22(10)2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-34067931

RESUMO

Consumption of high-calorie foods, such as diets rich in fats, is an important factor leading to the development of steatohepatitis. Several studies have suggested how lipid accumulation creates a lipotoxic microenvironment for cells, leading cells to deregulate their transcriptional and translational activity. This deregulation induces the development of liver diseases such as non-alcoholic fatty liver disease (NAFLD) and subsequently also the appearance of hepatocellular carcinoma (HCC) which is one of the deadliest types of cancers worldwide. Understanding its pathology and studying new biomarkers with better specificity in predicting disease prognosis can help in the personalized treatment of the disease. In this setting, understanding the link between NAFLD and HCC progression, the differentiation of each stage in between as well as the mechanisms underlying this process, are vital for development of new treatments and in exploring new therapeutic targets. Perilipins are a family of five closely related proteins expressed on the surface of lipid droplets (LD) in several tissues acting in several pathways involved in lipid metabolism. Recent studies have shown that Plin5 depletion acts protectively in the pathogenesis of liver injury underpinning the importance of pathways associated with PLIN5. PLIN5 expression is involved in pro-inflammatory cytokine regulation and mitochondrial damage, as well as endoplasmic reticulum (ER) stress, making it critical target of the NAFLD-HCC studies. The aim of this review is to dissect the recent findings and functions of PLIN5 in lipid metabolism, metabolic disorders, and NAFLD as well as the progression of NAFLD to HCC.


Assuntos
Carcinoma Hepatocelular/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Perilipina-5/metabolismo , Biomarcadores/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Humanos , Gotículas Lipídicas/metabolismo , Metabolismo dos Lipídeos/genética , Metabolismo dos Lipídeos/fisiologia , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas/metabolismo , Doenças Metabólicas/metabolismo , Perilipina-5/fisiologia , Microambiente Tumoral/fisiologia
6.
Obesity (Silver Spring) ; 29(6): 1074-1082, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34029446

RESUMO

OBJECTIVE: The purpose of this study was to characterize the metabolomic profiles of shift workers and day workers and to discover the effect of shift work on workers' metabolic health. METHODS: A total of 824 participants aged 25 to 55 years were recruited, and 485 (275 shift workers and 210 day workers) completed the study. The mean age of the shift workers was 37.32 (5.53) years old, and that of day workers was 36.50 (7.83) years old. Serum and salivary samples were collected for the detection of key biochemical indicators (melatonin, cholesterol, and low-density lipoprotein cholesterol) and for metabolome profile analyses. RESULTS: Compared with female day workers, female shift workers had a higher BMI, waist circumference, and hip circumference. Correspondingly, we identified 76 significant metabolites (false discovery rate < 0.05) in shift workers, including L-tryptophan, acylcarnitines, and several fatty acids. Three pathways that presented significant differences were biosynthesis of unsaturated fatty acids, linoleic acid metabolism, and ubiquinone and other terpenoid-quinone biosynthesis. CONCLUSIONS: Compared with day workers, shift workers were more prone to weight gain and central obesity and were at a higher risk for impaired lipid metabolism with disrupted circadian rhythms.


Assuntos
Ritmo Circadiano/fisiologia , Metaboloma/fisiologia , Jornada de Trabalho em Turnos , Adulto , Estudos de Casos e Controles , Colesterol/sangue , LDL-Colesterol/sangue , Estudos Transversais , Feminino , Humanos , Metabolismo dos Lipídeos/fisiologia , Masculino , Melatonina/sangue , Metabolômica , Pessoa de Meia-Idade , Obesidade/epidemiologia , Obesidade/etiologia , Obesidade/metabolismo , Jornada de Trabalho em Turnos/estatística & dados numéricos , Transtornos do Sono do Ritmo Circadiano/complicações , Transtornos do Sono do Ritmo Circadiano/epidemiologia , Transtornos do Sono do Ritmo Circadiano/metabolismo , Local de Trabalho/estatística & dados numéricos
7.
Methods Mol Biol ; 2295: 59-80, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34047972

RESUMO

Lipids are produced through a dynamic metabolic network involving branch points, cycles, reversible reactions, parallel reactions in different subcellular compartments, and distinct pools of the same lipid class involved in different parts of the network. For example, diacylglycerol (DAG) is a biosynthetic and catabolic intermediate of many different lipid classes. Triacylglycerol can be synthesized from DAG assembled de novo, or from DAG produced by catabolism of membrane lipids, most commonly phosphatidylcholine. Quantification of lipids provides a snapshot of the lipid abundance at the time they were extracted from the given tissue. However, quantification alone does not provide information on the path of carbon flux through the metabolic network to synthesize each lipid. Understanding lipid metabolic flux requires tracing lipid metabolism with isotopically labeled substrates over time in living tissue. [14C]acetate and [14C]glycerol are commonly utilized substrates to measure the flux of nascent fatty acids and glycerol backbones through the lipid metabolic network in vivo. When combined with mutant or transgenic plants, tracing of lipid metabolism can provide information on the molecular control of lipid metabolic flux. This chapter provides a method for tracing in vivo lipid metabolism in developing Arabidopsis thaliana seeds, including analysis of 14C labeled lipid classes and fatty acid regiochemistry through both thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) approaches.


Assuntos
Metabolismo dos Lipídeos/fisiologia , Redes e Vias Metabólicas/fisiologia , Plantas/metabolismo , Acetatos/química , Arabidopsis/metabolismo , Radioisótopos de Carbono/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia em Camada Delgada/métodos , Diglicerídeos/metabolismo , Ácidos Graxos/metabolismo , Glicerol/química , Lipídeos/química , Redes e Vias Metabólicas/genética , Sementes/metabolismo , Triglicerídeos/metabolismo
8.
Methods Mol Biol ; 2295: 179-201, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34047978

RESUMO

Total sterol content and composition in plant tissues can be easily determined by gas chromatography (GC) after saponification of the total lipid extract. However, in oleogenic tissues a significant proportion of the sterol is esterified to fatty acids, with GC methodologies unable to provide information about the proportion and the molecular species composition of intact steryl esters (SEs). Here we describe an electrospray ionization-tandem mass spectrometry (ESI-MS/MS) and Multiple Reaction Monitoring (MRM) method which, in parallel with GC analysis, allows for the accurate determination of both free and esterified sterol content and composition in seeds. After extraction of seed oil with hexane, free sterols are derivatized with undecanoyl chloride, total steryl esters are then purified from triacylglycerol (TAG) by liquid chromatography, infused and ionized as ammonium adducts, with molecular species identified and quantified by fragmentation in the presence of internal standards.


Assuntos
Ésteres/análise , Fitosteróis/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Cromatografia Gasosa/métodos , Esterificação , Ácidos Graxos/metabolismo , Glicoesfingolipídeos/metabolismo , Metabolismo dos Lipídeos/fisiologia , Lipídeos/química , Fitosteróis/metabolismo , Plantas/metabolismo , Sementes/química , Esteróis/análise , Espectrometria de Massas em Tandem/métodos
9.
Methods Mol Biol ; 2295: 321-335, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34047984

RESUMO

Plastoglobules are plastid compartments designed for the storage of neutral lipids. They share physical and structural characteristics with cytosolic lipid droplets. Hence, special care must be taken to avoid contamination by cytosolic lipid droplets during plastoglobule purification. We describe the isolation of pure plastoglobules from Arabidopsis thaliana leaves, and the methods we use to determine their lipid composition. After preparation of a crude chloroplast fraction, plastoglobules are isolated from plastid membranes by two steps of ultracentrifugation on discontinuous sucrose gradients. For lipid analyses, total lipids are then extracted by a standard chloroform-methanol protocol, and polar lipids are separated from neutral lipids by liquid-liquid extraction. While polar lipid classes are subsequently separated by thin-layer chromatography (TLC) with the classical Vitiello solvent mix, a double TLC development has to be performed for neutral lipids, to separate phytyl and steryl esters. Lipids are quantified by gas chromatography after conversion of the fatty acids into methyl esters.


Assuntos
Lipídeos/isolamento & purificação , Proteínas de Plantas/isolamento & purificação , Plastídeos/química , Arabidopsis/metabolismo , Proteínas de Arabidopsis/isolamento & purificação , Proteínas de Arabidopsis/metabolismo , Cloroplastos/química , Cromatografia Gasosa/métodos , Cromatografia em Camada Delgada/métodos , Ésteres , Ácidos Graxos/química , Metabolismo dos Lipídeos/fisiologia , Lipídeos/análise , Células Vegetais/metabolismo , Folhas de Planta , Proteínas de Plantas/análise , Plantas/química , Plantas/metabolismo , Plastídeos/metabolismo , Tilacoides
10.
Methods Mol Biol ; 2295: 295-320, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34047983

RESUMO

Cytosolic lipid droplets (LDs) are organelles which emulsify a variety of hydrophobic molecules in the aqueous cytoplasm of essentially all plant cells. Most familiar are the LDs from oilseeds or oleaginous fruits that primarily store triacylglycerols and serve a storage function. However, similar hydrophobic particles are found in cells of plant tissues that package terpenoids, sterol esters, wax esters, or other types of nonpolar lipids. The various hydrophobic lipids inside LDs are coated with a phospholipid monolayer, mostly derived from membrane phospholipids during their ontogeny. Various proteins have been identified to be associated with LDs, and these may be cell-type, tissue-type, or even species specific. While major LD proteins like oleosins have been known for decades, more recently a growing list of LD proteins has been identified, primarily by proteomics analyses of isolated LDs and confirmation of their localization by confocal microscopy. LDs, unlike other organelles, have a density less than that of water, and consequently can be isolated and enriched in cellular fractions by flotation centrifugation for composition studies. However, due to its deep coverage, modern proteomics approaches are also prone to identify contaminants, making control experiments necessary. Here, procedures for the isolation of LDs, and analysis of LD components are provided as well as methods to validate the LD localization of proteins.


Assuntos
Gotículas Lipídicas/química , Lipídeos/isolamento & purificação , Proteínas/isolamento & purificação , Citoplasma/química , Gotículas Lipídicas/metabolismo , Metabolismo dos Lipídeos/fisiologia , Lipídeos/análise , Organelas/química , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Células Vegetais/metabolismo , Plantas/química , Plantas/metabolismo , Proteínas/análise , Proteoma/metabolismo , Proteômica/métodos
11.
Methods Mol Biol ; 2295: 337-349, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34047985

RESUMO

Diverse classes of lipids are found in cell membranes, the major ones being glycerolipids, sphingolipids, and sterols. In eukaryotic cells, each organelle has a specific lipid composition, which defines its identity and regulates its biogenesis and function. For example, glycerolipids are present in all membranes, whereas sphingolipids and sterols are mostly enriched in the plasma membrane. In addition to phosphoglycerolipids, plants also contain galactoglycerolipids, a family of glycerolipids present mainly in chloroplasts and playing an important role in photosynthesis. During phosphate starvation, galactoglycerolipids are also found in large amounts in other organelles, illustrating the dynamic nature of membrane lipid composition. Thus, it is important to determine the lipid composition of each organelle, as analyses performed on total cells do not represent the specific changes occurring at the organelle level. This task requires the optimization of standard protocols to isolate organelles with high yield and low contamination by other cellular fractions. In this chapter, we describe a protocol to isolate mitochondria from Arabidopsis thaliana cell cultures to perform lipidomic analysis.


Assuntos
Cromatografia em Camada Delgada/métodos , Lipídeos/isolamento & purificação , Mitocôndrias/química , Arabidopsis/metabolismo , Proteínas de Arabidopsis/isolamento & purificação , Proteínas de Arabidopsis/metabolismo , Cloroplastos/metabolismo , Metabolismo dos Lipídeos/fisiologia , Lipídeos/análise , Lipídeos de Membrana/metabolismo , Mitocôndrias/metabolismo , Organelas/metabolismo , Fotossíntese , Células Vegetais/metabolismo , Plantas/química , Plantas/metabolismo , Espectrometria de Massas em Tandem/métodos
12.
Methods Mol Biol ; 2295: 351-361, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34047986

RESUMO

The plant phloem is a long-distance conduit for the transport of assimilates but also of mobile developmental and stress signals. These signals can be sugars, metabolites, amino acids, peptides, proteins, microRNA, or mRNA. Yet small lipophilic molecules such as oxylipins and, more recently, phospholipids have emerged as possible long-distance signals as well. Analysis of phloem (phospho)lipids, however, requires enrichment, purification, and sensitive analysis. This chapter describes the EDTA-facilitated approach of phloem exudate collection, phase partitioning against chloroform-methanol for lipid separation and enrichment, and analysis/identification of phloem lipids using LC-MS with multiplexed collision induced dissociation (CID).


Assuntos
Cromatografia em Camada Delgada/métodos , Lipídeos/isolamento & purificação , Floema/química , Arabidopsis/metabolismo , Proteínas de Arabidopsis/isolamento & purificação , Proteínas de Arabidopsis/metabolismo , Metabolismo dos Lipídeos/fisiologia , Lipídeos/análise , Lipídeos de Membrana/metabolismo , Floema/metabolismo , Células Vegetais/metabolismo , Plantas/química , Plantas/metabolismo , RNA Mensageiro/metabolismo , Açúcares/metabolismo , Espectrometria de Massas em Tandem/métodos
13.
Methods Mol Biol ; 2295: 391-399, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34047989

RESUMO

The study of lipid-protein interactions is crucial for understanding reactions of proteins involved in lipid metabolism, lipid transport, and lipid signaling. Different detection methods can be employed for the identification of lipid-binding interactions. Isothermal titration calorimetry (ITC) and surface plasmon resonance (SPR) spectroscopy enable real-time monitoring of lipid protein interactions and provide thermodynamic parameters of the interacting partners. However, these technologies depend on the availability of the large equipment, limiting the practicability in many laboratories. Protein-lipid overlay assays are a simple first approach to screen for protein interactions with different lipids or lipid intermediates and are independent of large equipment. Subsequently, specific interactions can be analyzed in detail using protein-liposome association assays.


Assuntos
Lipídeos/química , Mapeamento de Interação de Proteínas/métodos , Proteínas/química , Calorimetria/métodos , Cinética , Metabolismo dos Lipídeos/fisiologia , Lipossomos/química , Ligação Proteica , Transporte Proteico/fisiologia , Ressonância de Plasmônio de Superfície/métodos , Termodinâmica
14.
Methods Mol Biol ; 2295: 417-438, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34047991

RESUMO

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) has emerged as a major analytical platform for the determination and localization of lipid metabolites directly from tissue sections. Unlike analysis of lipid extracts, where lipid localizations are lost due to homogenization and/ or solvent extraction, MALDI-MSI analysis is capable of revealing spatial localization of metabolites while simultaneously collecting high chemical resolution mass spectra. Important considerations for obtaining high quality MALDI-MS images include tissue preservation, section preparation, MS data collection and data processing. Errors in any of these steps can lead to poor quality metabolite images and increases the chance for metabolite misidentification and/ or incorrect localization. Here, we present detailed methods and recommendations for specimen preparation, MALDI-MS instrument parameters, software analysis platforms for data processing, and practical considerations for each of these steps to ensure acquisition of high-quality chemical and spatial resolution data for reconstructing MALDI-MS images of plant tissues.


Assuntos
Lipídeos/química , Plantas/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Diagnóstico por Imagem/métodos , Técnicas Histológicas/métodos , Processamento de Imagem Assistida por Computador/métodos , Metabolismo dos Lipídeos/fisiologia , Plantas/metabolismo , Software
15.
Methods Mol Biol ; 2295: 441-454, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34047992

RESUMO

Along with the increase in knowledge on lipid metabolism during the last years, different lipid databases were established in a web-based system. This chapter presents an overview on plant lipid databases for simple and complex lipids focusing on nomenclature, structures as well as physical and chemical properties. Many databases provide information on methods and protocols for lipid isolation, fractionation, and analysis, including lipidomic procedures. References to the lipid literature are included in all databases. Additional data including mass spectra derived from GC-MS, LC-MS, and LC-MS/MS experiments are included in specialized lipid databases. An introduction is presented on how to use the most important lipid databases.


Assuntos
Bases de Dados Factuais/tendências , Plantas/química , Plantas/metabolismo , Cromatografia Líquida/métodos , Gerenciamento de Dados , Metabolismo dos Lipídeos/fisiologia , Lipidômica/métodos , Lipídeos/química , Espectrometria de Massas em Tandem/métodos
16.
Methods Mol Biol ; 2295: 455-468, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34047993

RESUMO

Pathways of lipid biosynthesis are highly complex and have been established in model organisms such as Arabidopsis thaliana and Chlamydomonas reinhardtii, whereas in other organisms, we need bioinformatic tools to map individual enzymes onto reference pathways. In this chapter, we explain representative tools that are useful in identifying algal orthologs of lipid biosynthetic enzymes and finding new enzymes that are possibly involved in the pathway of interest. All descriptions in this chapter refer to in silico (i.e., computer-based) methods rather than laboratory experiments.


Assuntos
Cianobactérias/química , Cianobactérias/metabolismo , Bases de Dados Factuais/tendências , Clorófitas/química , Clorófitas/metabolismo , Cromatografia Líquida/métodos , Biologia Computacional/métodos , Gerenciamento de Dados , Metabolismo dos Lipídeos/fisiologia , Lipidômica/métodos , Lipídeos/química , Rodófitas/química , Rodófitas/metabolismo , Espectrometria de Massas em Tandem/métodos
17.
Optom Vis Sci ; 98(4): 341-349, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33828039

RESUMO

SIGNIFICANCE: Previous in vitro measurements of contact lenses commonly investigate the impact of nonpolar tear film lipids (i.e., sterols). Polar lipids, however, are equally important stabilizing components of the tear film. This research explores and presents further knowledge about various aspects of polar lipid uptake that may impact contact lens performance. PURPOSE: This study evaluated the impact of incubation time, lipid concentration, and replenishment of an artificial tear solution (ATS) on the uptake of phosphatidylcholine (PC) onto conventional hydrogel (CH) and silicone hydrogel (SH) contact lens materials. METHODS: Four SHs and two CH lens materials (n = 4) were soaked in a complex ATS containing radioactive 14C-PC as a probe molecule. Phosphatidylcholine uptake was monitored at various incubation time points (1, 3, 7, 14, and 28 days), with different ATS lipid concentrations (0.5×, 1×, 2×) and with and without regular replenishment of the ATS. Phosphatidylcholine was extracted from the lenses, processed, and counted by a ß counter, and accumulated PC (µg/lens) was extrapolated from standard lipid calibration curves. RESULTS: All materials exhibited increasing PC deposition over time. Conventional hydrogel materials showed significantly lower PC uptake rates (P < .001) than any of the SH materials. Increasing lipid concentration in the ATS resulted in increased PC binding onto the contact lens materials (P < .001). Replenishing the ATS every other day, however, impacted the PC deposition differently, showing increased binding (P < .001) on CHs and reduced PC deposition for SH materials (P < .001). CONCLUSIONS: Length of incubation, lipid concentration in the ATS, and renewal of the incubation solution all influenced the amount of PC that sorbed onto various lens materials and therefore need to be considered when conducting future in vitro deposition studies.


Assuntos
Lentes de Contato Hidrofílicas , Fosfatidilcolinas/metabolismo , Adsorção , Hidrogéis , Metabolismo dos Lipídeos/fisiologia , Lubrificantes Oftálmicos/metabolismo , Silicones , Lágrimas/química
18.
Int J Mol Sci ; 22(9)2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33926097

RESUMO

Ovarian hormone deficiency leads to increased body weight, visceral adiposity, fatty liver and disorders associated with menopausal metabolic syndrome. To better understand the underlying mechanisms of these disorders in their early phases of development, we investigated the effect of ovariectomy on lipid and glucose metabolism. Compared to sham-operated controls, ovariectomized Wistar female rats markedly increased whole body and visceral adipose tissue weight (p ˂ 0.05) and exhibited insulin resistance in peripheral tissues. Severe hepatic triglyceride accumulation (p ˂ 0.001) after ovariectomy preceded changes in both serum lipids and glucose intolerance, reflecting alterations in some CYP proteins. Increased CYP2E1 (p ˂ 0.05) and decreased CYP4A (p ˂ 0.001) after ovariectomy reduced fatty acid oxidation and induced hepatic steatosis. Decreased triglyceride metabolism and secretion from the liver contributed to hepatic triglyceride accumulation in response to ovariectomy. In addition, interscapular brown adipose tissue of ovariectomized rats exhibited decreased fatty acid oxidation (p ˂ 0.01), lipogenesis (p ˂ 0.05) and lipolysis (p ˂ 0.05) despite an increase in tissue weight. The results provide evidence that impaired hepatic triglycerides and dysregulation of some CYP450 proteins may have been involved in the development of hepatic steatosis. The low metabolic activity of brown adipose tissue may have contributed to visceral adiposity as well as triglyceride accumulation during the postmenopausal period.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Transtornos do Metabolismo dos Lipídeos/etiologia , Metabolismo dos Lipídeos/fisiologia , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Sistema Enzimático do Citocromo P-450/fisiologia , Dieta Hiperlipídica , Dislipidemias/metabolismo , Fígado Gorduroso/metabolismo , Feminino , Glucose/metabolismo , Insulina/metabolismo , Resistência à Insulina , Gordura Intra-Abdominal/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Transtornos do Metabolismo dos Lipídeos/fisiopatologia , Lipídeos/sangue , Lipogênese/efeitos dos fármacos , Lipólise , Fígado/metabolismo , Menopausa/metabolismo , Menopausa/fisiologia , Obesidade/metabolismo , Ovariectomia/efeitos adversos , Pós-Menopausa/metabolismo , Pós-Menopausa/fisiologia , Ratos , Ratos Wistar , Triglicerídeos/metabolismo , Ganho de Peso
19.
Nutrients ; 13(4)2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33919779

RESUMO

Nutritional intake can influence exercise metabolism and performance, but there is a lack of research comparing protein-rich pre-exercise meals with endurance exercise performed both in the fasted state and following a carbohydrate-rich breakfast. The purpose of this study was to determine the effects of three pre-exercise nutrition strategies on metabolism and exercise capacity during cycling. On three occasions, seventeen trained male cyclists (VO2peak 62.2 ± 5.8 mL·kg-1·min-1, 31.2 ± 12.4 years, 74.8 ± 9.6 kg) performed twenty minutes of submaximal cycling (4 × 5 min stages at 60%, 80%, and 100% of ventilatory threshold (VT), and 20% of the difference between power at the VT and peak power), followed by 3 × 3 min intervals at 80% peak aerobic power and 3 × 3 min intervals at maximal effort, 30 min after consuming a carbohydrate-rich meal (CARB; 1 g/kg CHO), a protein-rich meal (PROTEIN; 0.45 g/kg protein + 0.24 g/kg fat), or water (FASTED), in a randomized and counter-balanced order. Fat oxidation was lower for CARB compared with FASTED at and below the VT, and compared with PROTEIN at 60% VT. There were no differences between trials for average power during high-intensity intervals (367 ± 51 W, p = 0.516). Oxidative stress (F2-Isoprostanes), perceived exertion, and hunger were not different between trials. Overall, exercising in the overnight-fasted state increased fat oxidation during submaximal exercise compared with exercise following a CHO-rich breakfast, and pre-exercise protein ingestion allowed similarly high levels of fat oxidation. There were no differences in perceived exertion, hunger, or performance, and we provide novel data showing no influence of pre-exercise nutrition ingestion on exercise-induced oxidative stress.


Assuntos
Ciclismo/fisiologia , Jejum/fisiologia , Refeições/fisiologia , Estresse Oxidativo/fisiologia , Adolescente , Adulto , Atletas , Desempenho Atlético/fisiologia , Carboidratos da Dieta/administração & dosagem , Proteínas na Dieta/administração & dosagem , Humanos , Fome/fisiologia , Metabolismo dos Lipídeos/fisiologia , Masculino , Oxirredução , Resistência Física/fisiologia , Esforço Físico/fisiologia , Adulto Jovem
20.
Nutrients ; 13(4)2021 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-33916877

RESUMO

The western dietary pattern is known for its frequent meals rich in saturated fat and protein, resulting in a postprandial state for a large part of the day. Therefore, our aim was to investigate the postprandial glucose and lipid metabolism in response to high (HP) or normal (NP) protein, high-fat hypercaloric diet and to identify early biomarkers of protein intake and hepatic lipid accumulation. In a crossover design, 17 healthy subjects were randomly assigned to consume a HP or NP hypercaloric diet for two weeks. In parallel, a control group (CD; n = 10) consumed a weight-maintaining control diet. Biomarkers of postprandial lipid and glucose metabolism were measured in 24 h urine and in plasma before and following a meal challenge. The metabolic profile of urine but not plasma, showed increased excretion of 13C, carnitine and short chain acyl-carnitines after adaptation to the HP diet. Urinary excretion of decatrienoylcarnitine and octenoylcarnitine increased after adaptation to the NP diet. Our results suggest that the higher excretion of short-chain urinary acyl-carnitines could facilitate the elimination of excess fat of the HP diet and thereby reduce hepatic fat accumulation previously reported, whereas the higher excretion medium-chains acyl-carnitine could be early biomarkers of hepatic lipid accumulation.


Assuntos
Carnitina/análogos & derivados , Dieta Hiperlipídica/efeitos adversos , Dieta Rica em Proteínas/efeitos adversos , Dieta Ocidental/efeitos adversos , Síndrome Metabólica/diagnóstico , Adulto , Biomarcadores/urina , Carnitina/metabolismo , Carnitina/urina , Estudos Cross-Over , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/metabolismo , Proteínas na Dieta/metabolismo , Ingestão de Energia/fisiologia , Feminino , Glucose/metabolismo , Voluntários Saudáveis , Humanos , Metabolismo dos Lipídeos/fisiologia , Fígado/metabolismo , Masculino , Síndrome Metabólica/etiologia , Síndrome Metabólica/metabolismo , Síndrome Metabólica/urina , Período Pós-Prandial/fisiologia , Eliminação Renal/fisiologia , Adulto Jovem
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