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1.
J Plant Physiol ; 243: 153047, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31639538

RESUMO

Acyl-CoA oxidase (ACX; EC 1.3.3.6) plays a vital role in the biosynthesis of jasmonic acid (JA) in plant peroxisomes. We previously identified an herbivore-induced gene CsACX1 in tea plant (Camellia sinensis) and showed CsACX1 was involved in the wound-induced synthesis of jasmonic acid (JA). Here, another ACX gene CsACX3 was isolated from tea plant. CsACX3 was predicted to consist of 684 amino acid residues. CsACX3 can be induced by mechanical wounding, JA application, and infestation by the tea geometrid Ectropis obliqua Prout and the tea green leafhopper Empoasca (Matsumurasca) onukii Matsuda. These expression patterns are consistent with the previously reported expression pattern of CsACX1 under such treatments. Recombinant CsACX3 showed preference for medium-chain acyl-coA oxidase substrates (C8- to C14-CoA). CsACX3 expression could also be induced by the infection of a pathogen Colletotrichum gloeosporioides (Cgl), and the increased ACX activities in tea plants were correlated with the Cgl-induced CsACX3 expression. Cgl could not induce the expression of CsACX1, which showed preference for C12- to C16-CoA substrates. The constitutive expression of CsACX3 rescued wound-induced JA biosynthesis and enhanced the Cgl-induced JA biosynthesis in Arabidopsis mutant atacx1. However, constitutive expression of CsACX1 could not enhance the Cgl-induced JA biosynthesis in atacx1 plant. These results indicate that CsACX1 and CsACX3 functions overlap and have distinct roles in the wound- and pathogen-activated de novo JA synthesis via enzymatic routes that utilize different ACX isozymes in tea plant.


Assuntos
Acil-CoA Oxidase/genética , Camellia sinensis/genética , Ciclopentanos/metabolismo , Expressão Gênica , Oxilipinas/metabolismo , Proteínas de Plantas/genética , Acil-CoA Oxidase/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Camellia sinensis/enzimologia , Camellia sinensis/metabolismo , Colletotrichum/fisiologia , Comportamento Alimentar , Cadeia Alimentar , Hemípteros/fisiologia , Isoenzimas/genética , Isoenzimas/metabolismo , Mariposas/fisiologia , Filogenia , Doenças das Plantas/microbiologia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
2.
Anim Reprod Sci ; 208: 106104, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31405453

RESUMO

The peri-calving period is characterized by a negative energy balance, which leads to lipid mobilization. Thus, during this period, the liver has important functions related to optimizing milk yield, preventing metabolic and infectious diseases, and improving fertility. To clarify the relationship between liver fatty acid metabolism and reproductive performance, the present study was conducted to assess the abundance of specific hepatic proteins related to lipid metabolism in both plasma and follicular fluid in dairy cattle with different days to conception (DC). Sixteen animals were grouped according to DC, as more and fewer DC (MDC and FDC, respectively). Blood and liver biopsies were sampled 14 days before the expected calving date and 4, 14 and 28 days after calving. The plasma beta-hydroxybutyric acid (BHBA) concentrations and the liver triacylglycerol (TAG) content were greater in the MDC group (P <  0.05), whereas the protein abundance of carnitine palmitoyl transferase 1 was greater in the FDC group (P < 0.05). Additionally, total bilirubin (TBil) concentration was less in the FDC than MDC group on day 28 (P < 0.05). These results indicate lipid mobilization and liver fatty acid oxidation capacity in dairy cows could contribute to the adaptations and reproductive performance.


Assuntos
Bovinos/fisiologia , Ácidos Graxos/metabolismo , Fígado/metabolismo , Reprodução/fisiologia , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Ração Animal , Criação de Animais Domésticos , Animais , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Bovinos/sangue , Diacilglicerol O-Aciltransferase/genética , Diacilglicerol O-Aciltransferase/metabolismo , Feminino , Regulação da Expressão Gênica , Metabolismo dos Lipídeos , PPAR alfa/genética , PPAR alfa/metabolismo , Período Periparto/sangue , Período Periparto/fisiologia , Gravidez , Triglicerídeos/metabolismo
3.
BMB Rep ; 52(9): 566-571, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31401980

RESUMO

Lymphoma is one of the most curable types of cancer. However, drug resistance is the main challenge faced in lymphoma treatment. Peroxisomal acyl-CoA oxidase 1 (ACOX1) is the rate-limiting enzyme in fatty acid ß-oxidation. Deregulation of ACOX1 has been linked to peroxisomal disorders and carcinogenesis in the liver. Currently, there is no information about the function of ACOX1 in lymphoma. In this study, we found that upregulation of ACOX1 promoted proliferation in lymphoma cells, while downregulation of ACOX1 inhibited proliferation and induced apoptosis. Additionally, overexpression of ACOX1 increased resistance to doxorubicin, while suppression of ACOX1 expression markedly potentiated doxorubicin-induced apoptosis. Interestingly, downregulation of ACOX1 promoted mitochondrial location of Bad, reduced mitochondrial membrane potential and provoked apoptosis by activating caspase-9 and caspase-3 related apoptotic pathway. Overexpression of ACOX1 alleviated doxorubicin-induced activation of caspase-9 and caspase-3 and decrease of mitochondrial membrane potential. Importantly, downregulation of ACOX1 increased p73, but not p53, expression. p73 expression was critical for apoptosis induction induced by ACOX1 downregulation. Also, overexpression of ACOX1 significantly reduced stability of p73 protein thereby reducing p73 expression. Thus, our study indicated that suppression of ACOX1 could be a novel and effective approach for treatment of lymphoma. [BMB Reports 2019; 52(9): 566-571].


Assuntos
Acil-CoA Oxidase/metabolismo , Doxorrubicina/farmacologia , Linfoma/metabolismo , Proteína Tumoral p73/metabolismo , Acil-CoA Oxidase/genética , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Western Blotting , Caspase 3/metabolismo , Caspase 9/metabolismo , Células HEK293 , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteína Tumoral p73/genética
4.
Redox Biol ; 26: 101253, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31234015

RESUMO

Fatty acid oxidation (FAO)-driven H2O2 has been shown to be a major source of oxidative stress in several tissues and disease states. Here, we established that the mitochondrial flavoprotein long-chain acyl-CoA dehydrogenase (LCAD), which catalyzes a key step in mitochondrial FAO, directly produces H2O2in vitro by leaking electrons to oxygen. Kinetic analysis of recombinant human LCAD showed that it produces H2O2 15-fold faster than the related mitochondrial enzyme very long-chain acyl-CoA dehydrogenase (VLCAD), but 50-fold slower than a bona fide peroxisomal acyl-CoA oxidase. The rate of H2O2 formation by human LCAD is slow compared to its activity as a dehydrogenase (about 1%). However, expression of hLCAD in HepG2 cells is sufficient to significantly increase H2O2 in the presence of fatty acids. Liver mitochondria from LCAD-/- mice, but not VLCAD-/- mice, produce significantly less H2O2 during incubation with fatty acids. Finally, we observe highest LCAD expression in human liver, followed by kidney, lung, and pancreas. Based on our data, we propose that the presence of LCAD drives H2O2 formation in response to fatty acids in these tissues.


Assuntos
Acil-CoA Desidrogenase de Cadeia Longa/metabolismo , Acil-CoA Oxidase/metabolismo , Ácidos Graxos/metabolismo , Peróxido de Hidrogênio/metabolismo , Fígado/enzimologia , Mitocôndrias Hepáticas/enzimologia , Acil-CoA Desidrogenase de Cadeia Longa/genética , Acil-CoA Oxidase/genética , Animais , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Células Hep G2 , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Rim/enzimologia , Cinética , Pulmão/enzimologia , Masculino , Camundongos , Camundongos Knockout , Especificidade de Órgãos , Oxirredução , Estresse Oxidativo , Pâncreas/enzimologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
5.
Environ Sci Pollut Res Int ; 26(21): 21828-21834, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31134545

RESUMO

The effect of selenium on excessive fatty acid-induced apoptosis and abnormal amino acid metabolism in the liver is well known, because it is an important site in the fatty acid metabolism pathway. However, the protective role of nano-elemental selenium (nano-Se) supplementation against hexavalent chromium (K2Cr2O7)-induced abnormal fatty acid metabolism has not been evaluated yet. Therefore, we conducted chicken experiments with different nano-Se supplementation doses to investigate the role of nano-Se against Cr(VI)-induced adverse effects. For this purpose, a total of 120 1-day-old chicks were randomly divided into control group, Cr(VI)-exposed group, protection group, treatment group, prevention group, and nano-Se control group. The results of RT-qPCR showed that the nano-Se supplementation notably downregulated (P < 0.01) the messenger RNA (mRNA) expression levels of fatty acid synthase (FASN), whereas nano-Se supplementation significantly upregulated (P < 0.01) the mRNA expression level of acyl-coenzyme A oxidase 1 (ACOX1) in chicken's liver at day 35 of the experiment. Similar results were further verified by western blot analysis. Moreover, nano-Se supplementation significantly enhanced and reduced the antibody expression levels of ACOX1 and FASN in immunohistochemical analysis, respectively. Thus, finally, it was concluded that nano-Se can alleviate K2Cr2O7-induced abnormal fatty acid metabolism in chicken's liver.


Assuntos
Galinhas/metabolismo , Cromo/toxicidade , Ácidos Graxos/metabolismo , Fígado/efeitos dos fármacos , Selênio/farmacologia , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Animais , Apoptose/efeitos dos fármacos , Suplementos Nutricionais , Ácido Graxo Sintase Tipo I/genética , Ácido Graxo Sintase Tipo I/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/genética , Fígado/metabolismo , Nanopartículas/administração & dosagem , Nanopartículas/química , Substâncias Protetoras/farmacologia , Selênio/administração & dosagem , Selênio/química
6.
Proc Natl Acad Sci U S A ; 116(21): 10576-10585, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31064880

RESUMO

Epigenetic markers, such as histone acetylation and DNA methylation, determine chromatin organization. In eukaryotic cells, metabolites from organelles or the cytosol affect epigenetic modifications. However, the relationships between metabolites and epigenetic modifications are not well understood in plants. We found that peroxisomal acyl-CoA oxidase 4 (ACX4), an enzyme in the fatty acid ß-oxidation pathway, is required for suppressing the silencing of some endogenous loci, as well as Pro35S:NPTII in the ProRD29A:LUC/C24 transgenic line. The acx4 mutation reduces nuclear histone acetylation and increases DNA methylation at the NOS terminator of Pro35S:NPTII and at some endogenous genomic loci, which are also targeted by the demethylation enzyme REPRESSOR OF SILENCING 1 (ROS1). Furthermore, mutations in multifunctional protein 2 (MFP2) and 3-ketoacyl-CoA thiolase-2 (KAT2/PED1/PKT3), two enzymes in the last two steps of the ß-oxidation pathway, lead to similar patterns of DNA hypermethylation as in acx4 Thus, metabolites from fatty acid ß-oxidation in peroxisomes are closely linked to nuclear epigenetic modifications, which may affect diverse cellular processes in plants.


Assuntos
Arabidopsis/metabolismo , Metilação de DNA , Epigênese Genética , Ácidos Graxos/metabolismo , Peroxissomos/metabolismo , ATP Citrato (pro-S)-Liase/metabolismo , Acetilação , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Histonas/metabolismo , Oxirredução , Plantas Geneticamente Modificadas , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo
7.
Hepatobiliary Pancreat Dis Int ; 18(4): 360-365, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31126802

RESUMO

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver diseases. However, the exact pathogenesis of NAFLD remains to be elucidated. Despite the association with tumors and cardiovascular diseases, the role of miR-222 in NAFLD remains unclear. The present study was to investigate the role of miR-222 in NAFLD. METHODS: Wild-type C57BL/6 mice were fed a high-fat diet for 12 weeks to induce NAFLD. Normal human liver cell line (L02) was cultured with free fatty acid (FFA)-containing medium to stimulate cell steatosis. The mRNA levels of miR-222 and acyl Coenzyme A xidase 1 (ACOX1) were detected by quantitative-PCR (Q-PCR). The prediction of ACOX1 as the target gene for miR-222 was conducted via TargetScan. The overexpression or inhibition of miR-222 was mediated by miR-222 mimics or antagomir, and intracellular triglyceride levels were measured using a triglyceride kit. Luciferase reporter assays verified ACOX1 as the target gene for miR-222. RESULTS: miR-222 was significantly elevated in both the in vivo and in vitro NAFLD models. Overexpression of miR-222 significantly increased triglyceride content in the L02 cells, while inhibition of miR-222 expression restricted the accumulation of triglyceride. Overexpression of miR-222 significantly inhibited ACOX1 expression. Transient transfection assays verified that ACOX1 3'-UTR luciferase reporter activity could be inhibited by miR-222 overexpression. CONCLUSIONS: The present study suggested that miR-222 promotes the accumulation of triglycerides by inhibiting ACOX1.


Assuntos
Acil-CoA Oxidase/metabolismo , Hepatócitos/enzimologia , MicroRNAs/metabolismo , Hepatopatia Gordurosa não Alcoólica/enzimologia , Oxirredutases/metabolismo , Triglicerídeos/metabolismo , Regiões 3' não Traduzidas , Acil-CoA Oxidase/genética , Animais , Sítios de Ligação , Linhagem Celular , Dieta Hiperlipídica , Modelos Animais de Doenças , Regulação Enzimológica da Expressão Gênica , Hepatócitos/patologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/patologia , Oxirredutases/genética , Regulação para Cima
8.
Lipids Health Dis ; 18(1): 11, 2019 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-30621686

RESUMO

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is closely linked to obesity, type 2 diabetes and other metabolic disorders worldwide. Crocin is a carotenoid compound possessing various pharmacological activities. In the present study, we aimed to investigate the effect on fatty liver under diabetic and obese condition and to examine the possible role of AMP-activated protein kinase (AMPK) signaling. METHODS: db/db mice were administrated with crocin and injected with LV-shAMPK or its negative control lentivirus. Metabolic dysfunction, lipogenesis and fatty acid-oxidation in liver were evaluated. RESULTS: In db/db mice, we found that oral administration of crocin significantly upregulated the phosphorylation of AMPK and downregulated the phosphorylation of mTOR in liver. Crocin reduced liver weight, serum levels of alanine aminotransferase, alanine aminotransferase, and liver triglyceride content, and attenuated morphological injury of liver in db/db mice. Crocin inhibited the mRNA expression of lipogenesis-associated genes, including sterol regulatory element binding protein-1c, peroxisome proliferator-activated receptor γ, fatty acid synthase, stearoyl-CoA desaturase 1, and diacylglycerol acyltransferase 1, and increased the mRNA expression of genes involved in the regulation of ß-oxidation of fatty acids, including PPARα, acyl-CoA oxidase 1, carnitine palmitoyltransferase 1, and 3-hydroxy-3-methylglutaryl-CoA synthase 2. Moreover, treatment of crocin resulted in a amelioration of general metabolic disorder, as evidenced by decreased fasting blood glucose, reduced serum levels of insulin, triglyceride, total cholesterol, and non-esterified fatty acid, and improved glucose intolerance. Crocin-induced protective effects against fatty liver and metabolic disorder were significantly blocked by lentivirus-mediated downregulation of AMPK. CONCLUSIONS: The results suggest that crocin can inhibit lipogenesis and promote ß-oxidation of fatty acids through activation of AMPK, leading to improvement of fatty liver and metabolic dysfunction. Therefore, crocin may be a potential promising option for the clinical treatment for NAFLD and associated metabolic diseases.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Fármacos Antiobesidade/farmacologia , Carotenoides/farmacologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/farmacologia , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Proteínas Quinases Ativadas por AMP/metabolismo , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Alanina Transaminase/sangue , Alanina Transaminase/genética , Animais , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/genética , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Diacilglicerol O-Aciltransferase/genética , Diacilglicerol O-Aciltransferase/metabolismo , Modelos Animais de Doenças , Ácido Graxo Sintases/antagonistas & inibidores , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Regulação da Expressão Gênica , Hidroximetilglutaril-CoA Sintase/genética , Hidroximetilglutaril-CoA Sintase/metabolismo , Lipogênese/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , PPAR alfa/agonistas , PPAR alfa/genética , PPAR alfa/metabolismo , PPAR gama/antagonistas & inibidores , PPAR gama/genética , PPAR gama/metabolismo , Transdução de Sinais , Estearoil-CoA Dessaturase/antagonistas & inibidores , Estearoil-CoA Dessaturase/genética , Estearoil-CoA Dessaturase/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/antagonistas & inibidores , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Resultado do Tratamento , Triglicerídeos/sangue
9.
J Clin Invest ; 129(2): 694-711, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30511960

RESUMO

Peroxisomes perform essential functions in lipid metabolism, including fatty acid oxidation and plasmalogen synthesis. Here, we describe a role for peroxisomal lipid metabolism in mitochondrial dynamics in brown and beige adipocytes. Adipose tissue peroxisomal biogenesis was induced in response to cold exposure through activation of the thermogenic coregulator PRDM16. Adipose-specific knockout of the peroxisomal biogenesis factor Pex16 (Pex16-AKO) in mice impaired cold tolerance, decreased energy expenditure, and increased diet-induced obesity. Pex16 deficiency blocked cold-induced mitochondrial fission, decreased mitochondrial copy number, and caused mitochondrial dysfunction. Adipose-specific knockout of the peroxisomal ß-oxidation enzyme acyl-CoA oxidase 1 (Acox1-AKO) was not sufficient to affect adiposity, thermogenesis, or mitochondrial copy number, but knockdown of the plasmalogen synthetic enzyme glyceronephosphate O-acyltransferase (GNPAT) recapitulated the effects of Pex16 inactivation on mitochondrial morphology and function. Plasmalogens are present in mitochondria and decreased with Pex16 inactivation. Dietary supplementation with plasmalogens increased mitochondrial copy number, improved mitochondrial function, and rescued thermogenesis in Pex16-AKO mice. These findings support a surprising interaction between peroxisomes and mitochondria regulating mitochondrial dynamics and thermogenesis.


Assuntos
Tecido Adiposo/metabolismo , Temperatura Baixa , Lipídeos/biossíntese , Mitocôndrias/metabolismo , Dinâmica Mitocondrial , Peroxissomos/metabolismo , Termogênese , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Animais , Células COS , Chlorocebus aethiops , Células HEK293 , Humanos , Lipídeos/genética , Camundongos , Camundongos Knockout , Mitocôndrias/genética , Peroxinas/genética , Peroxinas/metabolismo , Peroxissomos/genética , Plasmalogênios/farmacologia
10.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1864(4): 567-576, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30312667

RESUMO

Acyl-CoA oxidase 1 (ACOX1) deficiency is a rare and severe peroxisomal leukodystrophy associated with a very long-chain fatty acid (VLCFA) ß-oxidation defect. This neurodegenerative disease lacks relevant cell models to further decipher the pathomechanisms in order to identify novel therapeutic targets. Since peroxisomal defects in microglia appear to be a key component of peroxisomal leukodystrophies, we targeted the Acox1 gene in the murine microglial BV-2 cell line. Using CRISPR/Cas9 gene editing, we generated an Acox1-deficient cell line and validated the allelic mutations, which lead to the absence of ACOX1 protein and enzymatic activity. The activity of catalase, the enzyme degrading H2O2, was increased, likely in response to the alteration of redox homeostasis. The mutant cell line grew more slowly than control cells without obvious morphological changes. However, ultrastructural analysis revealed an increased number of peroxisomes and mitochondria associated with size reduction of mitochondria. Changes in the distribution of lipid droplets containing neutral lipids have been observed in mutant cells; lipid analysis revealed the accumulation of saturated and monounsaturated VLCFA. Besides, expression levels of genes encoding interleukin-1 beta and 6 (IL-1ß and IL-6), as well as triggering receptor expressed on myeloid cells 2 (Trem2) were found modified in the mutant cells suggesting modification of microglial polarization and phagocytosis ability. In summary, this Acox1-deficient cell line presents the main biochemical characteristics of the human disease and will serve as a promising model to further investigate the consequences of a specific microglial peroxisomal ß-oxidation defect on oxidative stress, inflammation and cellular functions.


Assuntos
Acil-CoA Oxidase/deficiência , Microglia/citologia , Modelos Biológicos , Mutação , Doenças Neurodegenerativas/genética , Acil-CoA Oxidase/genética , Animais , Sistemas CRISPR-Cas , Linhagem Celular , Proliferação de Células , Ácidos Graxos/metabolismo , Ácidos Graxos Insaturados/metabolismo , Edição de Genes , Peróxido de Hidrogênio/metabolismo , Camundongos , Microglia/metabolismo , Estresse Oxidativo
11.
Plant Physiol Biochem ; 135: 132-140, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30529979

RESUMO

The biosynthesis of jasmonic acid (JA) in plant peroxisomes requires the action of acyl-CoA oxidase (ACX; EC 1.3.3.6). Multiple isoforms of ACXs have been identified in various annual herbaceous plants, but the genes encoding these enzymes in perennial woody plants are yet to be fully investigated. In this study, an ACX gene named CsACX1 (GeneBank accession: KX650077.1) was isolated from tea plant (Camellia sinensis L.). CsACX1 was predicted to consist of 664 amino acid residues. Transcriptional analysis revealed that CsACX1 can be induced by mechanical wounding, JA application, and infestation by the tea geometrid Ectropis obliqua Prout and the tea green leafhopper Empoasca (Matsumurasca) onukii Matsuda. To further elucidate the function of CsACX1, it was heterologously expressed in a bacterial system and characterized. Recombinant CsACX1 showed preference for C12 ∼ C16-CoA substrates. The constitutive expression of CsACX1 can rescue wound-related JA biosynthesis in Arabidopsis mutant acx1. CsACX1 was expressed in different organs, predominantly in flowers. Notably, CsACX1 transcripts were detected up-regulated during flower opening, and the JA levels were correlated with CsACX1 expression. All these results enrich our knowledge of the regulatory pathway involved in the JA biosynthesis in tea, and helps further understand the defense mechanism of tea plant against insects.


Assuntos
Acil-CoA Oxidase/fisiologia , Camellia sinensis/fisiologia , Ciclopentanos/metabolismo , Flores/metabolismo , Genes de Plantas/fisiologia , Oxilipinas/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/fisiologia , Acil-CoA Oxidase/genética , Animais , Arabidopsis , Camellia sinensis/genética , Camellia sinensis/metabolismo , Escherichia coli , Flores/crescimento & desenvolvimento , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Hemípteros , Herbivoria , Filogenia , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase em Tempo Real , Alinhamento de Sequência , Análise de Sequência de DNA
12.
Proc Natl Acad Sci U S A ; 115(30): E7015-E7022, 2018 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-29987047

RESUMO

Robust molecular tool kits in model and industrial microalgae are key to efficient targeted manipulation of endogenous and foreign genes in the nuclear genome for basic research and, as importantly, for the development of algal strains to produce renewable products such as biofuels. While Cas9-mediated gene knockout has been demonstrated in a small number of algal species with varying efficiency, the ability to stack traits or generate knockout mutations in two or more loci are often severely limited by selectable agent availability. This poses a critical hurdle in developing production strains, which require stacking of multiple traits, or in probing functionally redundant gene families. Here, we combine Cas9 genome editing with an inducible Cre recombinase in the industrial alga Nannochloropsis gaditana to generate a strain, NgCas9+Cre+, in which the potentially unlimited stacking of knockouts and addition of new genes is readily achievable. Cre-mediated marker recycling is first demonstrated in the removal of the selectable marker and GFP reporter transgenes associated with the Cas9/Cre construct in NgCas9+Cre+ Next, we show the proof-of-concept generation of a markerless knockout in a gene encoding an acyl-CoA oxidase (Aco1), as well as the markerless recapitulation of a 2-kb insert in the ZnCys gene 5'-UTR, which results in a doubling of wild-type lipid productivity. Finally, through an industrially oriented process, we generate mutants that exhibit up to ∼50% reduction in photosynthetic antennae size by markerless knockout of seven genes in the large light-harvesting complex gene family.


Assuntos
Acil-CoA Oxidase , Sistemas CRISPR-Cas , Edição de Genes , Lipídeos , Característica Quantitativa Herdável , Estramenópilas , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Complexos de Proteínas Captadores de Luz/genética , Complexos de Proteínas Captadores de Luz/metabolismo , Lipídeos/biossíntese , Lipídeos/genética , Estramenópilas/genética , Estramenópilas/metabolismo
13.
Virulence ; 9(1): 1019-1035, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30052120

RESUMO

Lipid mediators, derived from arachidonic acid metabolism, play an important role in immune regulation. The functions of bioactive eicosanoids range from modulating cytokine signaling and inflammasome formation to anti-inflammatory and pro-resolving activities. Human pathogenic fungi such as Candida albicans, Candida parapsilosis, Cryptococcus neoformans and Aspergillus fumigatus have been shown to produce such lipid mediators, associated with their virulence. To date, investigations into the molecular mechanisms of fungal eicosanoid biosynthesis in different species have revealed that several genes are associated with prostaglandin production. However, these routes remain uncharacterized in C. parapsilosis with early results suggesting it uses pathways distinct from those found in C. albicans. Therefore, we aimed to identify and characterize C. parapsilosis genes involved in eicosanoid biosynthesis. Following arachidonic acid treatment of C. parapsilosis cells, we identified several genes interfering with prostaglandin production. Out of the identified genes, homologues of a multi copper oxidase (FET3), an Acyl-CoA thiolase (POT1) and an Acyl-CoA oxidase (POX1-3) were found to play a significant role in prostaglandin synthesis. Furthermore, all three genes were confirmed to enhance C. parapsilosis pathogenicity, as the corresponding deletion mutants were cleared more efficiently by human macrophages and induced higher levels of pro-inflammatory cytokines. In addition, the mutants were less virulent than the wild-type strain in a mouse model of systemic infection. Taken together, we identified three genes that regulate eicosanoid biosynthesis in C. parapsilosis and impact the fungus' virulence.


Assuntos
Candida parapsilosis/enzimologia , Candida parapsilosis/patogenicidade , Candidíase/microbiologia , Eicosanoides/biossíntese , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Animais , Vias Biossintéticas , Candida parapsilosis/genética , Coenzima A-Transferases/genética , Coenzima A-Transferases/metabolismo , Feminino , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Oxirredutases/genética , Oxirredutases/metabolismo , Virulência
14.
Food Chem Toxicol ; 116(Pt B): 360-368, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29704577

RESUMO

Remains unknown if dietary lipids and anabolic steroids (AS) can interact to modify energy metabolism, hepatic structure and function. We investigated the impact of AS on gene expression, lipid profile, redox status and the development of nonalcoholic fatty liver disease (NAFLD) in mice treated with a diet rich in trans fatty acids. Seventy-two C57BL/6 mice were equally randomized into six groups and treated with a standard diet (SD) or high-fat diet (HFD) alone or combined with testosterone cypionate (10 or 20 mg/kg) for 12 weeks. When combined with a HFD, AS reduced plasma HDL cholesterol levels. It also upregulated SREBP-1, PPARα, SCD-1 and ACOX1 gene expression; plasma and hepatic triglyceride levels; oxidative stress; circulating hepatic transaminase levels and NAFLD severity. Our finding indicated that the activity of antioxidant enzymes such as catalase, glutathione-s-transferase and superoxide dismutase was attenuated by HFD, an effect whose implications for AS-induced hepatotoxicity requires further investigation. Increased lipid, protein and DNA oxidative damage as well as worsening NAFLD in response to the interaction of HFD and AS were also potentially associated with the ability of AS to amplify the activation of regulatory lipid metabolism genes that are also involved in the control of cellular redox balance.


Assuntos
Interações Alimento-Droga , Fígado/efeitos dos fármacos , Hepatopatia Gordurosa não Alcoólica/induzido quimicamente , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Congêneres da Testosterona/toxicidade , Ácidos Graxos Trans/toxicidade , Triglicerídeos/metabolismo , Acil-CoA Oxidase/genética , Alanina Transaminase/sangue , Animais , Antioxidantes/metabolismo , Aspartato Aminotransferases/sangue , Composição Corporal , Catalase/sangue , Dieta Hiperlipídica , Regulação da Expressão Gênica , Glutationa Transferase/sangue , Fígado/metabolismo , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Estresse Oxidativo/efeitos dos fármacos , PPAR alfa/genética , Estearoil-CoA Dessaturase/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Superóxido Dismutase/sangue , Triglicerídeos/sangue , Regulação para Cima
15.
Regul Toxicol Pharmacol ; 95: 348-361, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29626562

RESUMO

Propaquizafop is an herbicide with demonstrated hepatocarcinogenic activity in rodents. A rodent-specific mode of action (MOA) in the liver via activation of peroxisome proliferator-activated receptor α (PPARα) has been postulated based on existing data. Experience with PPARα-inducing pharmaceuticals indicates a lack of human relevance of this MOA. The objective of the present investigation was to evaluate the dependency of early key events leading to liver tumors on PPARα activation in wildtype (WT) compared to PPARα-knockout (KO) rats following 2 weeks exposure to 75, 500 and 1000 ppm propaquizafop in the diet. In WT rats, both WY-14643 (50 mg/kg bw/day) and propaquizafop (dose-dependently) induced marked increases in liver weights, correlating with liver enlargement and hepatocellular hypertrophy, along with increased CYP4A and acyl-CoA oxidase mRNA expression and enzyme activities versus controls, while in KO rats liver weight was mildly increased only at the high dose with minimal microscopic correlates and without any changes in liver peroxisomal or CYP4A activities. In addition, BrdU labeling resulted in higher numbers and density of positive hepatocytes versus controls in WT but not in KO rats, indicating increased mitotic activity and cell proliferation only in WT rats, thus confirming the PPARα-dependency of the biochemical and histological changes in the liver. Based on an assessment of the results of this investigation, together with existing propaquizafop data according to the MOA-Human Relevance Framework, we conclude that liver tumors observed in rodents after dietary administration of propaquizafop do not pose a relevant health risk to humans.


Assuntos
Herbicidas/toxicidade , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/metabolismo , PPAR alfa/metabolismo , Propionatos/toxicidade , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Animais , Sistema Enzimático do Citocromo P-450/metabolismo , Dieta , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , PPAR alfa/genética , Ratos Sprague-Dawley , Ratos Transgênicos , Medição de Risco
16.
JCI Insight ; 3(6)2018 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-29563328

RESUMO

Nonalcoholic fatty liver disease (NAFLD), a metabolic predisposition for development of hepatocellular carcinoma (HCC), represents a disease spectrum ranging from steatosis to steatohepatitis to cirrhosis. Acox1, a rate-limiting enzyme in peroxisomal fatty acid ß-oxidation, regulates metabolism, spontaneous hepatic steatosis, and hepatocellular damage over time. However, it is unknown whether Acox1 modulates inflammation relevant to NAFLD pathogenesis or if Acox1-associated metabolic and inflammatory derangements uncover and accelerate potential for NAFLD progression. Here, we show that mice with a point mutation in Acox1 (Acox1Lampe1) exhibited altered cellular metabolism, modified T cell polarization, and exacerbated immune cell inflammatory potential. Further, in context of a brief obesogenic diet stress, NAFLD progression associated with Acox1 mutation resulted in significantly accelerated and exacerbated hepatocellular damage via induction of profound histological changes in hepatocytes, hepatic inflammation, and robust upregulation of gene expression associated with HCC development. Collectively, these data demonstrate that ß-oxidation links metabolism and immune responsiveness and that a better understanding of peroxisomal ß-oxidation may allow for discovery of mechanisms central for NAFLD progression.


Assuntos
Acil-CoA Oxidase/metabolismo , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Acil-CoA Oxidase/genética , Tecido Adiposo Marrom/metabolismo , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Citocinas/metabolismo , Dieta , Modelos Animais de Doenças , Progressão da Doença , Ácidos Graxos/metabolismo , Regulação Neoplásica da Expressão Gênica , Hepatócitos/patologia , Inflamação , Fígado/imunologia , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática , Neoplasias Hepáticas/genética , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Obesidade , Mutação Puntual , Estresse Fisiológico , Linfócitos T
17.
EMBO Rep ; 19(5)2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29491006

RESUMO

Peroxisomes account for ~35% of total H2O2 generation in mammalian tissues. Peroxisomal ACOX1 (acyl-CoA oxidase 1) is the first and rate-limiting enzyme in fatty acid ß-oxidation and a major producer of H2O2 ACOX1 dysfunction is linked to peroxisomal disorders and hepatocarcinogenesis. Here, we show that the deacetylase sirtuin 5 (SIRT5) is present in peroxisomes and that ACOX1 is a physiological substrate of SIRT5. Mechanistically, SIRT5-mediated desuccinylation inhibits ACOX1 activity by suppressing its active dimer formation in both cultured cells and mouse livers. Deletion of SIRT5 increases H2O2 production and oxidative DNA damage, which can be alleviated by ACOX1 knockdown. We show that SIRT5 downregulation is associated with increased succinylation and activity of ACOX1 and oxidative DNA damage response in hepatocellular carcinoma (HCC). Our study reveals a novel role of SIRT5 in inhibiting peroxisome-induced oxidative stress, in liver protection, and in suppressing HCC development.


Assuntos
Acil-CoA Oxidase/antagonistas & inibidores , Acil-CoA Oxidase/metabolismo , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Estresse Oxidativo , Sirtuínas/metabolismo , Acil-CoA Oxidase/genética , Animais , Dano ao DNA , Regulação para Baixo , Feminino , Técnicas de Silenciamento de Genes , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Peróxido de Hidrogênio , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Oxirredução , Peroxissomos/química , Prognóstico , Sirtuínas/genética
18.
Biotechnol Bioeng ; 115(7): 1793-1800, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29573412

RESUMO

Squalene, a valuable acyclic triterpene, can be used as a chemical commodity for pharmacology, flavor, and biofuel industries. Microbial production of squalene has been of great interest due to its limited availability, and increasing prices extracted from animal and plant tissues. Here we report genetic perturbations that synergistically improve squalene production in Saccharomyces cerevisiae. As reported previously, overexpression of a truncated HMG-CoA reductase 1 (tHMG1) led to the accumulation 20-fold higher squalene than a parental strain. In order to further increase squalene accumulation in the tHMG1 overexpressing yeast, we introduced genetic perturbations-known to increase lipid contents in yeast-to enhance squalene accumulation as lipid body is a potential storage of squalene. Specifically, DGA1 coding for diacylglycerol acyltranferase was overexpressed to enhance lipid biosynthesis, and POX1 and PXA2 coding for acyl-CoA oxidase and a subunit of peroxisomal ABC transporter were deleted to reduce lipid ß-oxidation. Simultaneous overexpression of tHMG1 and DGA1 coding for rate-limiting enzymes in the mevalonate and lipid biosynthesis pathways led to over 250-fold higher squalene accumulation than a control strain. However, deletion of POX1 and PXA2 in the tHMG1 overexpressing yeast did not improve squalene accumulation additionally. Fed-batch fermentation of the tHMG1 and DGA1 co-overexpressing yeast strain resulted in the production of squalene at a titer of 445.6 mg/L in a nitrogen-limited minimal medium. This report demonstrates that increasing storage capacity for hydrophobic compounds can enhance squalene production, suggesting that increasing lipid content is an effective strategy to overproduce a hydrophobic molecule in yeast.


Assuntos
Metabolismo dos Lipídeos , Engenharia Metabólica/métodos , Redes e Vias Metabólicas/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Esqualeno/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Diacilglicerol O-Aciltransferase/genética , Diacilglicerol O-Aciltransferase/metabolismo , Expressão Gênica , Hidroximetilglutaril-CoA Redutases/genética , Hidroximetilglutaril-CoA Redutases/metabolismo , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
19.
Cancer Res ; 78(10): 2490-2502, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29535221

RESUMO

Although emerging evidence suggests a potential role of calcium/calmodulin-dependent kinase II (CaMKII) in prostate cancer, its role in prostate cancer tumorigenesis is largely unknown. Here, we examine whether the acetyl CoA-CaMKII pathway, first described in frog oocytes, promotes prostate cancer tumorigenesis. In human prostate cancer specimens, metastatic prostate cancer expressed higher levels of active CaMKII compared with localized prostate cancer. Correspondingly, basal CaMKII activity was significantly higher in the more tumorigenic PC3 and PC3-mm2 cells relative to the less tumorigenic LNCaP and C4-2B4 cells. Deletion of CaMKII by CRISPR/Cas9 in PC3-mm2 cells abrogated cell survival under low-serum conditions, anchorage-independent growth and cell migration; overexpression of constitutively active CaMKII in C4-2B4 cells promoted these phenotypes. In an animal model of prostate cancer metastasis, genetic ablation of CaMKII reduced PC3-mm2 cell metastasis from the prostate to the lymph nodes. Knockdown of the acetyl-CoA transporter carnitine acetyltransferase abolished CaMKII activation, providing evidence that acetyl-CoA generated from organelles is a major activator of CaMKII. Genetic deletion of the ß-oxidation rate-limiting enzyme ACOX family proteins decreased CaMKII activation, whereas overexpression of ACOXI increased CaMKII activation. Overall, our studies identify active CaMKII as a novel connection between organelle ß-oxidation and acetyl-CoA transport with cell survival, migration, and prostate cancer metastasis.Significance: This study identifies a cell metabolic pathway that promotes prostate cancer metastasis and suggests prostate cancer may be susceptible to ß-oxidation inhibitors. Cancer Res; 78(10); 2490-502. ©2018 AACR.


Assuntos
Acetilcoenzima A/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Carcinogênese/genética , Movimento Celular/genética , Sobrevivência Celular/genética , Neoplasias da Próstata/patologia , Acil-CoA Oxidase/genética , Animais , Sistemas CRISPR-Cas/genética , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Carnitina O-Acetiltransferase/genética , Linhagem Celular Tumoral , Ácidos Graxos/metabolismo , Humanos , Metástase Linfática/genética , Metástase Linfática/patologia , Masculino , Camundongos , Camundongos Knockout , Camundongos SCID , Oxirredução , Oxirredutases/genética , Células PC-3
20.
Cell Physiol Biochem ; 45(5): 2021-2030, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29529605

RESUMO

BACKGROUND/AIMS: Acetic acid (AcOH), a short-chain fatty acid, is reported to have some beneficial effects on metabolism. Therefore, the aim of this study was to investigate the regulatory mechanism of acetic acid on hepatic lipid metabolism in BRL-3A cells. METHODS: We cultured and treated BRL-3A cells with different concentrations of sodium acetate (neutralized acetic acid) and BML-275 (an AMPKα inhibitor). The total lipid droplet area was measured by oil red O staining, and the triglyceride content was determined by a triglyceride detection kit. We detected mRNA and protein levels of lipid metabolism-related signalling molecules by RT-PCR and Western blot. RESULTS: Acetic acid treatment increased AMPKα phosphorylation, which subsequently increased the expression and transcriptional activity of peroxisome proliferator-activated receptor α and upregulated the expression of lipid oxidation genes. These changes ultimate led to increasing levels of lipid oxidation in BRL-3A cells. Furthermore, elevated AMPKα phosphorylation reduced the expression and transcriptional activity of the sterol regulatory element-binding protein 1c, which reduced the expression of lipogenic genes, thereby decreasing lipid biosynthesis in BRL-3A cells. Consequently, triglyceride content in acetate-treated BRL-3A cells was significantly decreased. CONCLUSIONS: These results indicate that acetic acid activates the AMPKα signalling pathway, leading to increased lipid oxidation and decreased lipid synthesis in BRL-3A cells, thereby reducing liver fat accumulation in vitro.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Ácido Acético/toxicidade , Metabolismo dos Lipídeos/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Animais , Apoptose/efeitos dos fármacos , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Linhagem Celular , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/metabolismo , PPAR alfa/genética , PPAR alfa/metabolismo , Fosforilação/efeitos dos fármacos , Pirazóis/farmacologia , Pirimidinas/farmacologia , Ratos , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Triglicerídeos/metabolismo
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