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1.
Anticancer Res ; 40(9): 4843-4856, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32878772

RESUMO

Aberrant fatty acid (FA) metabolism has long been recognized in colorectal cancer (CRC) cells. Since de novo lipogenesis is required for CRC tumour growth and survival, the inhibition of FA metabolism is a promising potential therapeutic target. Inhibition of the opposite process, ß-oxidation of FAs, has also showed promising results in many CRC models. For patients with CRC, both FA synthesis and ß-oxidation inhibitors are promising potential therapeutic options as monotherapies or as combination therapies with other anticancer agents. In this review, we discuss recent reports concerning inhibitors of FA synthesis and ß-oxidation in various CRC models. The exact mechanisms of action of the selected compounds described in this review remain unknown and require precise evaluation before the development of new successful therapies for CRC is possible.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Colorretais/metabolismo , Inibidores Enzimáticos/farmacologia , Ácidos Graxos/metabolismo , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Inibidores Enzimáticos/uso terapêutico , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Oxirredução/efeitos dos fármacos
2.
Nat Commun ; 11(1): 4830, 2020 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-32973134

RESUMO

Non-invasively probing metabolites within single live cells is highly desired but challenging. Here we utilize Raman spectro-microscopy for spatial mapping of metabolites within single cells, with the specific goal of identifying druggable metabolic susceptibilities from a series of patient-derived melanoma cell lines. Each cell line represents a different characteristic level of cancer cell de-differentiation. First, with Raman spectroscopy, followed by stimulated Raman scattering (SRS) microscopy and transcriptomics analysis, we identify the fatty acid synthesis pathway as a druggable susceptibility for differentiated melanocytic cells. We then utilize hyperspectral-SRS imaging of intracellular lipid droplets to identify a previously unknown susceptibility of lipid mono-unsaturation within de-differentiated mesenchymal cells with innate resistance to BRAF inhibition. Drugging this target leads to cellular apoptosis accompanied by the formation of phase-separated intracellular membrane domains. The integration of subcellular Raman spectro-microscopy with lipidomics and transcriptomics suggests possible lipid regulatory mechanisms underlying this pharmacological treatment. Our method should provide a general approach in spatially-resolved single cell metabolomics studies.


Assuntos
Melanoma/metabolismo , Metabolômica/métodos , Microscopia/métodos , Análise Espectral Raman/métodos , Apoptose , Linhagem Celular Tumoral , Ácidos Graxos/metabolismo , Humanos , Gotículas Lipídicas , Metabolismo dos Lipídeos , Lipidômica , Lipídeos , Ácido Oleico , Estearoil-CoA Dessaturase/metabolismo , Transcriptoma
3.
Adv Exp Med Biol ; 1274: 5-27, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32894505

RESUMO

Biophysical properties of membranes are dependent on their glycerophospholipid compositions. Lysophospholipid acyltransferases (LPLATs) selectively incorporate fatty chains into lysophospholipids to affect the fatty acid composition of membrane glycerophospholipids. Lysophosphatidic acid acyltransferases (LPAATs) of the 1-acylglycerol-3-phosphate O-acyltransferase (AGPAT) family incorporate fatty chains into phosphatidic acid during the de novo glycerophospholipid synthesis in the Kennedy pathway. Other LPLATs of both the AGPAT and the membrane bound O-acyltransferase (MBOAT) families further modify the fatty chain compositions of membrane glycerophospholipids in the remodeling pathway known as the Lands' cycle. The LPLATs functioning in these pathways possess unique characteristics in terms of their biochemical activities, regulation of expressions, and functions in various biological contexts. Essential physiological functions for LPLATs have been revealed in studies using gene-deficient mice, and important roles for several enzymes are also indicated in human diseases where their mutation or dysregulation causes or contributes to the pathological condition. Now several LPLATs are emerging as attractive therapeutic targets, and further understanding of the mechanisms underlying their physiological and pathological roles will aid in the development of novel therapies to treat several diseases that involve altered glycerophospholipid metabolism.


Assuntos
1-Acilglicerofosfocolina O-Aciltransferase/antagonistas & inibidores , Aciltransferases/antagonistas & inibidores , Membrana Celular/metabolismo , Desenvolvimento de Medicamentos , Glicerofosfolipídeos/biossíntese , Glicerofosfolipídeos/química , 1-Acilglicerofosfocolina O-Aciltransferase/metabolismo , Aciltransferases/metabolismo , Animais , Membrana Celular/química , Membrana Celular/enzimologia , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Humanos
4.
Adv Exp Med Biol ; 1274: 71-99, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32894508

RESUMO

Bioactive lipid mediators resulting from the metabolism of polyunsaturated fatty acids (PUFA) are controlled by many pathways that regulate the levels of these mediators and maintain homeostasis to prevent disease. PUFA metabolism is driven primarily through three pathways. Two pathways, the cyclooxygenase (COX) and lipoxygenase (LO) enzymatic pathways, form metabolites that are mostly inflammatory, while the third route of metabolism results from the oxidation by the cytochrome P450 enzymes to form hydroxylated PUFA and epoxide metabolites. These epoxygenated fatty acids (EpFA) demonstrate largely anti-inflammatory and beneficial properties, in contrast to the other metabolites formed from the degradation of PUFA. Dysregulation of these systems often leads to chronic disease. Pharmaceutical targets of disease focus on preventing the formation of inflammatory metabolites from the COX and LO pathways, while maintaining the EpFA and increasing their concentration in the body is seen as beneficial to treating and preventing disease. The soluble epoxide hydrolase (sEH) is the major route of metabolism of EpFA. Inhibiting its activity increases concentrations of beneficial EpFA, and often disease states correlate to mutations in the sEH enzyme that increase its activity and decrease the concentrations of EpFA in the body. Recent approaches to increasing EpFA include synthetic mimics that replicate biological activity of EpFA while preventing their metabolism, while other approaches focus on developing small molecule inhibitors to the sEH. Increasing EpFA concentrations in the body has demonstrated multiple beneficial effects in treating many diseases, including inflammatory and painful conditions, cardiovascular disease, neurological and disease of the central nervous system. Demonstration of efficacy in so many disease states can be explained by the fundamental mechanism that EpFA have of maintaining healthy microvasculature and preventing mitochondrial and endoplasmic reticulum stress. While there are no FDA approved methods that target the sEH or other enzymes responsible for metabolizing EpFA, current clinical efforts to test for efficacy by increasing EpFA that include inhibiting the sEH or administration of EpFA mimics that block metabolism are in progress.


Assuntos
Doenças Cardiovasculares/tratamento farmacológico , Estresse do Retículo Endoplasmático , Ácidos Graxos/metabolismo , Inflamação/tratamento farmacológico , Mitocôndrias/patologia , Terapia de Alvo Molecular , Manejo da Dor , Doenças Cardiovasculares/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Humanos , Inflamação/patologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Dor
5.
Int Heart J ; 61(5): 1014-1021, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32879261

RESUMO

Impaired fatty acid metabolism is associated with heart failure (HF) prognosis. However, specific changes in acylcarnitine profiles and their potential clinical value have not been well explored in patients recovering from acute decompensation.This study recruited 79 HF patients hospitalized because of acute decompensation with a left ventricular ejection fraction (LVEF) of < 40% and 51 normal controls. Patients were dichotomized into two groups, namely, the "improved (IMP) " and the "non-improved (NIMP) " groups, as defined by the changes in LVEF from baseline to 12 months after discharge. Mass spectrometry was used to quantify the acylcarnitine concentrations at baseline and 6 and 12 months after discharge. The IMP and NIMP groups contained 42 and 37 patients, respectively. At baseline, HF patients had higher plasma concentrations of specific long-, medium-, and short-chain acylcarnitines compared to normal controls. From baseline to 12 months post-discharge, the IMP group showed significant decreases in long- and short-chain acylcarnitine concentrations, but significant increases in medium-chain acylcarnitines. In the NIMP group, none of the acylcarnitines significantly decreased, and significant increases were noted in long-, medium-, and short-chain acylcarnitines. Generalized estimating equations demonstrated that nine acylcarnitines could discriminate the IMP group from the NIMP group, including three long-chain (C18:1, C16, and C16:1) and six short-chain acylcarnitines (C5, C5-OH, C4, C4:1-DC, C3, and C2). After adjusting for age, the six short-chain acylcarnitines remained significant. Changes in short-chain acylcarnitine profiles are independently associated with the improvement in cardiac systolic function after acute decompensation.


Assuntos
Carnitina/análogos & derivados , Ácidos Graxos/metabolismo , Insuficiência Cardíaca/metabolismo , Metabolômica , Idoso , Carnitina/metabolismo , Estudos de Casos e Controles , Ésteres/metabolismo , Feminino , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Humanos , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Prognóstico , Volume Sistólico , Sístole
6.
Nat Commun ; 11(1): 4879, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978379

RESUMO

Synthetic biology allows us to bioengineer cells to synthesize novel valuable molecules such as renewable biofuels or anticancer drugs. However, traditional synthetic biology approaches involve ad-hoc engineering practices, which lead to long development times. Here, we present the Automated Recommendation Tool (ART), a tool that leverages machine learning and probabilistic modeling techniques to guide synthetic biology in a systematic fashion, without the need for a full mechanistic understanding of the biological system. Using sampling-based optimization, ART provides a set of recommended strains to be built in the next engineering cycle, alongside probabilistic predictions of their production levels. We demonstrate the capabilities of ART on simulated data sets, as well as experimental data from real metabolic engineering projects producing renewable biofuels, hoppy flavored beer without hops, fatty acids, and tryptophan. Finally, we discuss the limitations of this approach, and the practical consequences of the underlying assumptions failing.


Assuntos
Aprendizado de Máquina , Engenharia Metabólica/métodos , Biologia Sintética/métodos , Teorema de Bayes , Cerveja , Biocombustíveis , Dodecanol/metabolismo , Escherichia coli/metabolismo , Ácidos Graxos/metabolismo , Saccharomyces cerevisiae/metabolismo
7.
Nat Commun ; 11(1): 4765, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958780

RESUMO

Fatty acids (FAs) are essential nutrients, but how they are transported into cells remains unclear. Here, we show that FAs trigger caveolae-dependent CD36 internalization, which in turn delivers FAs into adipocytes. During the process, binding of FAs to CD36 activates its downstream kinase LYN, which phosphorylates DHHC5, the palmitoyl acyltransferase of CD36, at Tyr91 and inactivates it. CD36 then gets depalmitoylated by APT1 and recruits another tyrosine kinase SYK to phosphorylate JNK and VAVs to initiate endocytic uptake of FAs. Blocking CD36 internalization by inhibiting APT1, LYN or SYK abolishes CD36-dependent FA uptake. Restricting CD36 at either palmitoylated or depalmitoylated state eliminates its FA uptake activity, indicating an essential role of dynamic palmitoylation of CD36. Furthermore, blocking endocytosis by targeting LYN or SYK inhibits CD36-dependent lipid droplet growth in adipocytes and high-fat-diet induced weight gain in mice. Our study has uncovered a dynamic palmitoylation-regulated endocytic pathway to take up FAs.


Assuntos
Antígenos CD36/metabolismo , Endocitose/fisiologia , Ácidos Graxos/metabolismo , Lipoilação , Células 3T3-L1 , Aciltransferases/metabolismo , Adipócitos/metabolismo , Animais , Antígenos CD36/deficiência , Antígenos CD36/genética , Cavéolas/metabolismo , Células Cultivadas , Dieta Hiperlipídica/efeitos adversos , Humanos , Gotículas Lipídicas/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Obesidade/tratamento farmacológico , Fosforilação , Transdução de Sinais , Quinase Syk/antagonistas & inibidores , Quinase Syk/metabolismo , Ganho de Peso/efeitos dos fármacos , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/metabolismo
8.
Mol Cell ; 80(1): 43-58.e7, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32937100

RESUMO

Immune cell function depends on specific metabolic programs dictated by mitochondria, including nutrient oxidation, macromolecule synthesis, and post-translational modifications. Mitochondrial adaptations have been linked to acute and chronic inflammation, but the metabolic cues and precise mechanisms remain unclear. Here we reveal that histone deacetylase 3 (HDAC3) is essential for shaping mitochondrial adaptations for IL-1ß production in macrophages through non-histone deacetylation. In vivo, HDAC3 promoted lipopolysaccharide-induced acute inflammation and high-fat diet-induced chronic inflammation by enhancing NLRP3-dependent caspase-1 activation. HDAC3 configured the lipid profile in stimulated macrophages and restricted fatty acid oxidation (FAO) supported by exogenous fatty acids for mitochondria to acquire their adaptations and depolarization. Rather than affecting nuclear gene expression, HDAC3 translocated to mitochondria to deacetylate and inactivate an FAO enzyme, mitochondrial trifunctional enzyme subunit α. HDAC3 may serve as a controlling node that balances between acquiring mitochondrial adaptations and sustaining their fitness for IL-1ß-dependent inflammation.


Assuntos
Ácidos Graxos/metabolismo , Histona Desacetilases/metabolismo , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Mitocôndrias/metabolismo , Adulto , Animais , Caspase 1/metabolismo , Feminino , Humanos , Inflamação/patologia , Metabolismo dos Lipídeos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Mitocôndrias/ultraestrutura , Subunidade alfa da Proteína Mitocondrial Trifuncional/metabolismo , Células Mieloides/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Oxirredução , Fosforilação Oxidativa , Adulto Jovem
9.
Plant Mol Biol ; 104(3): 283-296, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32740897

RESUMO

KEY MESSAGE: Differences in FAE1 enzyme affinity for the acyl-CoA substrates, as well as the balance between the different pathways involved in their incorporation to triacylglycerol might be determinant of the different composition of the seed oil in Brassicaceae. Brassicaceae present a great heterogeneity of seed oil and fatty acid composition, accumulating Very Long Chain Fatty Acids with industrial applications. However, the molecular determinants of these differences remain elusive. We have studied the ß-ketoacyl-CoA synthase from the high erucic feedstock Thlaspi arvense (Pennycress). Functional characterization of the Pennycress FAE1 enzyme was performed in two Arabidopsis backgrounds; Col-0, with less than 2.5% of erucic acid in its seed oil and the fae1-1 mutant, deficient in FAE1 activity, that did not accumulate erucic acid. Seed-specific expression of the Pennycress FAE1 gene in Col-0 resulted in a 3 to fourfold increase of erucic acid content in the seed oil. This increase was concomitant with a decrease of eicosenoic acid levels without changes in oleic ones. Interestingly, only small changes in eicosenoic and erucic acid levels occurred when the Pennycress FAE1 gene was expressed in the fae1-1 mutant, with high levels of oleic acid available for elongation, suggesting that the Pennycress FAE1 enzyme showed higher affinity for eicosenoic acid substrates, than for oleic ones in Arabidopsis. Erucic acid was incorporated to triacylglycerol in the transgenic lines without significant changes in their levels in the diacylglycerol fraction, suggesting that erucic acid was preferentially incorporated to triacylglycerol via DGAT1. Expression analysis of FAE1, AtDGAT1, AtLPCAT1 and AtPDAT1 genes in the transgenic lines further supported this conclusion. Differences in FAE1 affinity for the oleic and eicosenoic substrates among Brassicaceae, as well as their incorporation to triacylglycerol might explain the differences in composition of their seed oil.


Assuntos
3-Oxoacil-(Proteína de Transporte de Acila) Sintase/metabolismo , Biocombustíveis , Vias Biossintéticas , Brassicaceae/metabolismo , Thlaspi/enzimologia , Thlaspi/metabolismo , Triglicerídeos/biossíntese , 1-Acilglicerofosfocolina O-Aciltransferase/metabolismo , 3-Oxoacil-(Proteína de Transporte de Acila) Sintase/genética , Aciltransferases/metabolismo , Sequência de Aminoácidos , Proteínas de Arabidopsis/metabolismo , Vias Biossintéticas/genética , Diacilglicerol O-Aciltransferase/metabolismo , Ácidos Erúcicos/metabolismo , Elongases de Ácidos Graxos/genética , Elongases de Ácidos Graxos/metabolismo , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica de Plantas , Fenótipo , Óleos Vegetais/metabolismo , Plantas Geneticamente Modificadas , Sementes/genética , Análise de Sequência , Thlaspi/genética , Transcriptoma
10.
Georgian Med News ; (303): 161-167, 2020 Jun.
Artigo em Russo | MEDLINE | ID: mdl-32841199

RESUMO

The review summarizes the current knowledge about inborn errors of fatty acid metabolism (disorders of carnitine transport and mitochondrial fatty acid oxidation), characterized by high mortality, predominant damage of the central nervous system, heart, liver and skeletal muscles. The article presents the main clinical genetic features of diseases this group. After the introduction of newborn screening using the tandem mass-spectrometry (MS/MS), early identification of fatty acid metabolism defects became possible. Using of MS/MS method is promising for mass newborn screening. Early identification and accordingly timely initiated treatment prevents unfavorable outcome. Moreover, a specified medical-genetic diagnosis allows further prenatal diagnosis of pathology in subsequent pregnancies.


Assuntos
Ácidos Graxos/metabolismo , Metabolismo dos Lipídeos/genética , Erros Inatos do Metabolismo , Triagem Neonatal , Espectrometria de Massas em Tandem , Feminino , Humanos , Recém-Nascido , Mitocôndrias , Oxirredução , Gravidez
11.
Nat Commun ; 11(1): 3897, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32753587

RESUMO

Lipo-chitooligosaccharides (LCOs) are signaling molecules produced by rhizobial bacteria that trigger the nodulation process in legumes, and by some fungi that also establish symbiotic relationships with plants, notably the arbuscular and ecto mycorrhizal fungi. Here, we show that many other fungi also produce LCOs. We tested 59 species representing most fungal phyla, and found that 53 species produce LCOs that can be detected by functional assays and/or by mass spectroscopy. LCO treatment affects spore germination, branching of hyphae, pseudohyphal growth, and transcription in non-symbiotic fungi from the Ascomycete and Basidiomycete phyla. Our findings suggest that LCO production is common among fungi, and LCOs may function as signals regulating fungal growth and development.


Assuntos
Quitina/análogos & derivados , Quitina/metabolismo , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Transdução de Sinais/fisiologia , Ascomicetos/crescimento & desenvolvimento , Basidiomycota/crescimento & desenvolvimento , Ecologia , Ácidos Graxos/metabolismo , Micorrizas/fisiologia , Rhizobium/metabolismo , Esporos Fúngicos/crescimento & desenvolvimento , Simbiose/fisiologia
12.
Ecotoxicol Environ Saf ; 204: 111005, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32738624

RESUMO

Freezing temperatures is an important stressor in the arctic regions and has a significant influence on the population dynamics and geographic distribution of terrestrial invertebrates. Toxic metals in the environment can interfere with protective cold-acclimation responses of organisms. It is therefore important to evaluate the combined effects of cold stress and environmental contaminants. Here, we aimed to investigate the effects of Hg (HgCl2) on various physiological aspects of freeze-tolerance in the earthworm (Enchytraeus albidus). We measured the levels of the cryoprotectant glucose, the glycogen content (source of glucose molecules for cryoprotection and fuel for metabolism), and changes in the composition of membrane phospholipid fatty acids (PLFA) as an indicator of lipid peroxidation. Freezing at -6 °C had no effect on survival in uncontaminated soil, however, survival of freezing in Hg contaminated soil was clearly reduced, especially at extended exposure times. Thus, the LC50 value in frozen soil decreased from 8.3 mg Hg kg-1 (when exposed for 17 days) to only 4.2 mg Hg kg-1 after 36 days' exposure indicating that combined effects of Hg and freezing became larger at prolonged exposure times. Hg caused a depletion of glycogen reserves (almost 50% at 12 mg kg-1 dry soil), but despite this effect worms were able to maintain a constant cryoprotectant level (about 0.12 mg glucose mg-1 dry weight) at all Hg concentrations. Hg had clear negative effects on the proportion of unsaturated PLFAs, which could be an indication of lipid peroxidation. Since a high proportion of unsaturated fatty acids in the membrane is important for invertebrate freeze-tolerance, our results suggest that the negative effect of Hg on freeze-tolerance in E. albidus is related to degraded membrane functionality at low temperature.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Congelamento , Cloreto de Mercúrio/efeitos adversos , Oligoquetos/efeitos dos fármacos , Animais , Crioprotetores/farmacologia , Relação Dose-Resposta a Droga , Ácidos Graxos/metabolismo , Glucose/farmacologia , Glicogênio/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Mercúrio/efeitos adversos
13.
Life Sci ; 258: 118030, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32739470

RESUMO

The risk of atherosclerosis (AS) ascends among post-menopausal women, while current hormone replacement therapy exerts several adverse effects. Alisol B 23-acetate (AB23A), a tetracyclic triterpenoid isolated from the rhizome of Alisma orientale, was reported to show multiple physiological activities, including regulating lipid metabolism. According to molecular docking analysis, it was predicted to bind with estrogen receptor α (ERα). In this study, we aimed to observe the effect of AB23A on preventing post-menopausal AS and explore whether the mechanism was mediated by ERα. In vitro, free fatty acid (FFA) was applied to induce the abnormal lipid metabolism of L02 cells. In vivo, the ApoE-/- mice were ovariectomized to mimic the cessation of estrogen. The high-fat diet was also given to induce post-menopausal AS. We demonstrated AB23A attenuated the accumulation of total cholesterol and triglyceride induced by free fatty acids in hepatocytes. In high-fat diet-ovariectomy-treated ApoE-/- mice, AB23A eliminated lipids in blood and liver. AB23A not only reduced the synthesis of proprotein convertase subtilisin/kexin type 9 (PCSK9) through sterol-regulatory element binding proteins (SREBPs) but also suppressed the secretion of PCSK9 through silent information regulator 1 (SIRT1). Notably, AB23A promoted the expression of ERα in vivo and in vitro. The both ERα inhibitor and ERα siRNA were also applied in confirming whether the hepatic protective effect of AB23A was mediated by ERα. We found that AB23A significantly promoted the expression of ERα. AB23A could inhibit the synthesis and secretion of PCSK9 through ERα, lower the accumulation of triglyceride and cholesterol, and prevent post-menopausal AS.


Assuntos
Aterosclerose/patologia , Colestenonas/farmacologia , Receptor alfa de Estrogênio/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Pós-Menopausa/efeitos dos fármacos , Animais , Aterosclerose/genética , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Colestenonas/química , Dieta Hiperlipídica , Ácidos Graxos/metabolismo , Feminino , Lipoproteínas LDL/metabolismo , Camundongos , Ovariectomia , Regiões Promotoras Genéticas/genética , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo , Receptores de LDL/genética , Receptores de LDL/metabolismo , Sirtuína 1/metabolismo , Proteínas de Ligação a Elemento Regulador de Esterol/genética , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismo , Regulação para Cima/efeitos dos fármacos
14.
Nat Commun ; 11(1): 3360, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620763

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is considered the next major health epidemic with an estimated 25% worldwide prevalence. No drugs have yet been approved and NAFLD remains a major unmet need. Here, we identify MCJ (Methylation-Controlled J protein) as a target for non-alcoholic steatohepatitis (NASH), an advanced phase of NAFLD. MCJ is an endogenous negative regulator of the respiratory chain Complex I that acts to restrain mitochondrial respiration. We show that therapeutic targeting of MCJ in the liver with nanoparticle- and GalNAc-formulated siRNA efficiently reduces liver lipid accumulation and fibrosis in multiple NASH mouse models. Decreasing MCJ expression enhances the capacity of hepatocytes to mediate ß-oxidation of fatty acids and minimizes lipid accumulation, which results in reduced hepatocyte damage and fibrosis. Moreover, MCJ levels in the liver of NAFLD patients are elevated relative to healthy subjects. Thus, inhibition of MCJ emerges as an alternative approach to treat NAFLD.


Assuntos
Ácidos Graxos/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Fígado/patologia , Mitocôndrias/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Chaperonas Moleculares/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Adulto , Idoso , Animais , Conjuntos de Dados como Assunto , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Feminino , Proteínas de Choque Térmico HSP40/antagonistas & inibidores , Proteínas de Choque Térmico HSP40/genética , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Fígado/citologia , Fígado/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/genética , Chaperonas Moleculares/antagonistas & inibidores , Chaperonas Moleculares/genética , Nanopartículas/administração & dosagem , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Oxirredução/efeitos dos fármacos , Cultura Primária de Células , RNA Interferente Pequeno/administração & dosagem , RNA-Seq
15.
Plant Mol Biol ; 104(1-2): 187-201, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32681357

RESUMO

KEY MESSAGE: The mutation of FAX1 (Fatty Acid Export 1) disrupts ROS homeostasis and suppresses transcription activity of DYT1-TDF1-AMS-MS188 genetic network, leading to atypical tapetum PCD and defective pollen formation in Arabidopsis. Fatty acids (FAs) have multiple important biological functions and exert diverse cellular effects through modulating Reactive Oxygen Species (ROS) homeostasis. Arabidopsis FAX1 (Fatty Acid Export 1) mediates the export of de novo synthesized FA from chloroplast and loss of function of FAX1 impairs male fertility. However, mechanisms underlying the association of FAX1-mediated FA export with male sterility remain enigmatic. In this study, by using an integrated approach that included morphological, cytological, histological, and molecular analyses, we revealed that loss of function of FAX1 breaks cellular FA/lipid homeostasis, which disrupts ROS homeostasis and suppresses transcriptional activation of the DYT1-TDF1-AMS-MS188 genetic network of anther development, impairing tapetum development and pollen wall formation, and resulting in male sterility. This study provides new insights into the regulatory network for male reproduction in plants, highlighting an important role of FA export-mediated ROS homeostasis in the process.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ácidos Graxos/metabolismo , Proteínas de Membrana/metabolismo , Pólen/metabolismo , Arabidopsis/citologia , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Flores/citologia , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Redes Reguladoras de Genes , Proteínas de Membrana/genética , Mutação , Fenótipo , Pólen/genética , Reprodução , Fatores de Transcrição
16.
Nat Commun ; 11(1): 3703, 2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32710080

RESUMO

Mycobacterium tuberculosis is a pathogen with a unique cell envelope including very long fatty acids, implicated in bacterial resistance and host immune modulation. FasR is a TetR-like transcriptional activator that plays a central role in sensing mycobacterial long-chain fatty acids and regulating lipid biosynthesis. Here we disclose crystal structures of M. tuberculosis FasR in complex with acyl effector ligands and with DNA, uncovering its molecular sensory and switching mechanisms. A long tunnel traverses the entire effector-binding domain, enabling long fatty acyl effectors to bind. Only when the tunnel is entirely occupied, the protein dimer adopts a rigid configuration with its DNA-binding domains in an open state, leading to DNA dissociation. The protein-folding hydrophobic core connects the two domains, and is completed into a continuous spine when the effector binds. Such a transmission spine is conserved in a large number of TetR-like regulators, offering insight into effector-triggered allosteric functional control.


Assuntos
Acil Coenzima A/química , Proteínas de Bactérias/química , Proteínas de Ligação a DNA/química , Mycobacterium tuberculosis/metabolismo , Fatores de Transcrição/química , Acil Coenzima A/metabolismo , Sítio Alostérico , Proteínas de Bactérias/metabolismo , Parede Celular/metabolismo , Cristalografia por Raios X , DNA Bacteriano/química , Proteínas de Ligação a DNA/metabolismo , Ácidos Graxos/metabolismo , Ligantes , Modelos Moleculares , Conformação Proteica , Fatores de Transcrição/metabolismo
17.
PLoS Genet ; 16(7): e1008779, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32730248

RESUMO

Staphylococcus aureus is an opportunistic pathogen that can grow in a wide array of conditions: on abiotic surfaces, on the skin, in the nose, in planktonic or biofilm forms and can cause many type of infections. Consequently, S. aureus must be able to adapt rapidly to these changing growth conditions, an ability largely driven at the posttranscriptional level. RNA helicases of the DEAD-box family play an important part in this process. In particular, CshA, which is part of the degradosome, is required for the rapid turnover of certain mRNAs and its deletion results in cold-sensitivity. To understand the molecular basis of this phenotype, we conducted a large genetic screen isolating 82 independent suppressors of cold growth. Full genome sequencing revealed the fatty acid synthesis pathway affected in many suppressor strains. Consistent with that result, sublethal doses of triclosan, a FASII inhibitor, can partially restore growth of a cshA mutant in the cold. Overexpression of the genes involved in branched-chain fatty acid synthesis was also able to suppress the cold-sensitivity. Using gas chromatography analysis of fatty acids, we observed an imbalance of straight and branched-chain fatty acids in the cshA mutant, compared to the wild-type. This imbalance is compensated in the suppressor strains. Thus, we reveal for the first time that the cold sensitive growth phenotype of a DEAD-box mutant can be explained, at least partially, by an improper membrane composition. The defect correlates with an accumulation of the pyruvate dehydrogenase complex mRNA, which is inefficiently degraded in absence of CshA. We propose that the resulting accumulation of acetyl-CoA fuels straight-chained fatty acid production at the expense of the branched ones. Strikingly, addition of acetate into the medium mimics the cshA deletion phenotype, resulting in cold sensitivity suppressed by the mutations found in our genetic screen or by sublethal doses of triclosan.


Assuntos
RNA Helicases DEAD-box/genética , Ácidos Graxos/metabolismo , Infecções Estafilocócicas/genética , Staphylococcus aureus/genética , Proteínas de Bactérias/genética , Biofilmes/crescimento & desenvolvimento , Ácidos Graxos/genética , Regulação Bacteriana da Expressão Gênica/genética , Humanos , Proteínas de Membrana/genética , RNA Mensageiro/genética , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Staphylococcus aureus/patogenicidade
18.
Proc Natl Acad Sci U S A ; 117(28): 16324-16332, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601219

RESUMO

FadE, an acyl-CoA dehydrogenase, introduces unsaturation to carbon chains in lipid metabolism pathways. Here, we report that FadE5 from Mycobacterium tuberculosis (MtbFadE5) and Mycobacterium smegmatis (MsFadE5) play roles in drug resistance and exhibit broad specificity for linear acyl-CoA substrates but have a preference for those with long carbon chains. Here, the structures of MsFadE5 and MtbFadE5, in the presence and absence of substrates, have been determined. These reveal the molecular basis for the broad substrate specificity of these enzymes. FadE5 interacts with the CoA region of the substrate through a large number of hydrogen bonds and an unusual π-π stacking interaction, allowing these enzymes to accept both short- and long-chain substrates. Residues in the substrate binding cavity reorient their side chains to accommodate substrates of various lengths. Longer carbon-chain substrates make more numerous hydrophobic interactions with the enzyme compared with the shorter-chain substrates, resulting in a preference for this type of substrate.


Assuntos
Acil-CoA Desidrogenase/química , Acil-CoA Desidrogenase/metabolismo , Mycobacterium/enzimologia , Acil Coenzima A/metabolismo , Acil-CoA Desidrogenase/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Domínio Catalítico , Farmacorresistência Bacteriana/genética , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Modelos Moleculares , Mutação , Mycobacterium/efeitos dos fármacos , Mycobacterium/genética , Conformação Proteica , Relação Estrutura-Atividade , Especificidade por Substrato
19.
Life Sci ; 257: 118028, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32615185

RESUMO

AIMS: Sertoli cells (SCs) play an important role in the process of spermatogenesis. SCs provide energy for germ cells (GCs) and themselves through glycolysis and fatty acid oxidation (FAO) respectively. High fat diet (HFD) impairs spermatogenesis by damaging function of SCs, however whether HFD disrupts energy metabolism in SCs remains unclear. MAIN METHODS: To explore this hypothesis, we built male Wistar rat model fed on HFD and cultured rats' primary SCs with palmitic acid (PA). Rats' fertility and sperm quality were evaluated in vivo. Glycolysis, lactate production and mitochondrial respiration were assessed by using extracellular flux analyzer, and the expression of enzymes involved in glucose and FAO was analyzed by Real-Time PCR or Western Blotting. KEY FINDINGS: The showed that the sperm concentration and pups per litter significantly decreased in rats fed on HFD compared to those rats fed on normal diet. There was an elevation of lactate levels in testicular tissue of rats fed on HFD and primary SCs exposed to PA. In vitro, PA increased glycolytic flux, and lactate production, and the levels of carnitine palmitoyltransferase I (CPT1) and long chain acyl-CoA dehydrogenase (LCAD) which were two key enzymes for fatty acid ß oxidation. Further analysis showed that mitochondrial respiration was impaired by PA, followed by the decrease in ATP turnover, maximal respiration and the increase in proton leak. SIGNIFICANCE: Taken together, the elevated lactate level, lipid metabolism disorder and mitochondrial dysfunction caused by HFD lead to SCs dysfunction, which ultimately leads to decreased sperm quality.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Células de Sertoli/metabolismo , Espermatogênese/fisiologia , Animais , Metabolismo Energético , Ácidos Graxos/metabolismo , Glucose/metabolismo , Glicólise , Insulina/metabolismo , Metabolismo dos Lipídeos/fisiologia , Masculino , Oxirredução , Ácido Palmítico , Ratos , Ratos Wistar , Triglicerídeos/metabolismo
20.
Life Sci ; 257: 118122, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32702446

RESUMO

AIMS: Berberine is an isoquinoline alkaloid extracted from the root, rhizome and stem bark of Coptidis Rhizoma. Previous studies have revealed the anti-tumor potential of berberine against various types of cancer cells. However, the underlying mechanisms are not yet fully understood. In this study, we focused on the effects of berberine on fatty acid synthesis and extracellular vesicles formation in cancer cells, and revealed the internal mechanism of berberine inhibition on cancer cell proliferation. MATERIALS AND METHODS: Anti-proliferative activity of berberine was determined by cell counting and microscope observation and cell cycle analysis. Activities of AMPK and ACC, expression of extracellular vesicles markers were detected by western blotting. 13C labeling metabolic flux analysis was used for determination of de novo synthesis of fatty acids. The excreted extracellular vesicles in culture mediums were separated by both polyethylene glycol enrichment of extracellular vesicles and differential centrifugation separation. KEY FINDINGS: Among our early experiments, 5-10 µmol/L berberine exhibited the substantial anti-proliferative effect against human colon cancer cell line HCT116, cervical cancer cell line HeLa and other cancer cells. It was also revealed that, through activating AMPK, berberine inhibited ACC activity then suppressed intracellular fatty acid synthesis, finally decreased the biogenesis of extracellular vesicles. Moreover, supplement with citrate acid, palmitic acid, as well as exogenous extracellular vesicles, could rescue the inhibitory effect of berberine on cell proliferation, suggesting that inhibited ACC activity, suppressed fatty acid synthesis and decreased extracellular vesicles production were important mechanisms account for berberine inhibiting cancer cell proliferation. SIGNIFICANCE: Our study indicates that berberine suppresses cancer cell proliferation through inhibiting the synthesis of fatty acids and decreasing biogenesis and secretion of extracellular vesicles, suggests that berberine is a promising candidate for the development of new therapies for cancer.


Assuntos
Antineoplásicos/farmacologia , Berberina/farmacologia , Vesículas Extracelulares/metabolismo , Ácidos Graxos/metabolismo , Neoplasias/tratamento farmacológico , Proteínas Quinases Ativadas por AMP/metabolismo , Acetil-CoA Carboxilase/metabolismo , Western Blotting , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ácido Cítrico/farmacologia , Vesículas Extracelulares/efeitos dos fármacos , Células HCT116/efeitos dos fármacos , Células HeLa/efeitos dos fármacos , Humanos
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