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1.
Sheng Wu Gong Cheng Xue Bao ; 36(10): 2171-2180, 2020 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-33169581

RESUMO

In most insects, polyunsaturated fatty acids (PUFAs) are mainly polyunsaturated fatty acids with a carbon-chain length less than 18 carbon atoms, hardly any long-chain polyunsaturated fatty acids such as C20 and C22 that are more valuable and bioactive. This study, by using Drosophila melanogaster (Fruit fly) as a model organism, optimized the Δ6-fatty acid elongase enzyme Elovl5 gene from mice and transferred it to fruit flies for expression. Vectors containing Elovl5 gene were successfully injected into drosophila embryo through the microscopic injection. There were enhanced green fluorescent proteins expressed in the whole developmental stage of Drosophila be means of fluorescence microscope. At the same time, expression of Elovl5 gene significantly contributed to the transformation of fruit flies C18-polyunsaturated fatty acids in the body towards the biosynthesis of longer-chain polyunsaturated fatty acids. The transgenic fruit fly model rich in long-chain polyunsaturated fatty acids such as C20 and C22 were obtained, providing a basis for further research on biosynthesis of polyunsaturated fatty acids in fruit flies.


Assuntos
Acetiltransferases , Drosophila melanogaster , Elongases de Ácidos Graxos , Ácidos Graxos , Acetiltransferases/genética , Animais , Drosophila melanogaster/genética , Elongases de Ácidos Graxos/genética , Elongases de Ácidos Graxos/metabolismo , Ácidos Graxos/biossíntese , Ácidos Graxos/genética , Técnicas de Transferência de Genes , Camundongos
2.
DNA Cell Biol ; 39(11): 1926-1937, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33001759

RESUMO

GPR84 is an inflammation-induced receptor highly expressed on immune cells, yet its endogenous ligand is still unknown. This makes any interpretation of its physiological activity in vivo difficult. However, experiments with potent synthetic agonists have highlighted what the receptor can do, namely, enhance proinflammatory signaling and macrophage effector functions such as phagocytosis. Developing drugs to block these effects has attracted interest from the scientific community with the aim of decreasing disease activity in inflammatory disorders or enhancing inflammation resolution. In this review, we critically reassess the widely held belief that the major role of GPR84 is that of being a medium-chain fatty acid (MCFA) receptor. While MCFAs have been shown to activate GPR84, it remains to be demonstrated that they are present in relevant tissues at appropriate concentrations. In contrast to four other "full-time" free fatty acid receptor subtypes, GPR84 is not expressed by enteroendocrine cells and has limited expression in the gastrointestinal tract. Across multiple tissues and cell types, the highest expression levels of GPR84 are observed hours after exposure to an inflammatory stimulus. These factors obscure the relationship between ligand and receptor in the human body and do not support the exclusive physiological pairing of MCFAs with GPR84. To maximize the chances of developing efficacious drugs for inflammatory diseases, we must advance our understanding of GPR84 and what it does in vivo.


Assuntos
Ácidos Graxos/genética , Inflamação/genética , Receptores Acoplados a Proteínas-G/genética , Ácidos Graxos/metabolismo , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/patologia , Humanos , Inflamação/metabolismo , Inflamação/patologia , Ligantes , Macrófagos/metabolismo , Fagocitose/genética , Transdução de Sinais/genética
3.
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
4.
Ecotoxicol Environ Saf ; 203: 110943, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678750

RESUMO

High temperature damage impairs the growth of tall fescue by inhibiting secondary metabolites. Little is known about the regulation pattern of the fatty acids and carbohydrate metabolism at the whole-transcriptome level in tall fescue under high temperature stress. Here, two tall fescue genotypes, heat tolerant PI578718 and heat sensitive PI234881 were subjected to high temperature stress for 36 h. PI 578718 showed higher SPAD chloroplast value, lower EL and leaf injury than PI 234881 during the first 36 h high-temperature stress. Furthermore, by transcriptomic analysis, 121 genes were found to be induced during the second energy production phase in tall fescue exposed to high-temperature conditions, indicating that there may be one energy-sensing system in cool-season turfgrass to adapt high-temperature conditions. PI 578718 showed higher differentially expressed unigenes involved in fatty acids and carbohydrate metabolism compared with PI 234881 for 36 h heat stress. Interestingly, a metabolomic analysis using GC-MS uncovered that the sugars and sugar alcohol accounted for more than 65.06% of the total 41 metabolites content and high-temperature elevated the rate to 82.89-91.16% in PI 578718. High-temperature damage decreased the rate of fatty acid in the total 41 metabolites content and PI 578718 showed lower content than in PI 234881, which might be attributed to the down-regulated genes in fatty acid biosynthesis pathway in tall fescue. The integration of deep transcriptome and metabolome analyses provides systems-wide datasets to facilitate the identification of crucial regulation factors in cool-season turfgrass in response to high-temperature damage.


Assuntos
Metabolismo dos Carboidratos/efeitos dos fármacos , Ácidos Graxos/metabolismo , Festuca , Resposta ao Choque Térmico , Temperatura Alta , Metabolismo dos Carboidratos/genética , Ácidos Graxos/genética , Festuca/genética , Festuca/crescimento & desenvolvimento , Festuca/metabolismo , Perfilação da Expressão Gênica , Resposta ao Choque Térmico/genética , Metabolômica , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo
5.
Sci Rep ; 10(1): 3749, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32111914

RESUMO

Lipoyl synthases are key enzymes in lipoic acid biosynthesis, a co-factor of several enzyme complexes involved in central metabolism. Plant pyruvate dehydrogenase complex (PDH), located in mitochondria and plastids, catalyses the first step of fatty acid biosynthesis in these organelles. Among their different components, the E2 subunit requires the lipoic acid prosthetic group to be active. De novo lipoic acid biosynthesis is achieved by the successive action of two enzymes on octanoyl-ACP: octanoyltransferase (LIP2) and lipoyl synthase (LIP1). In this study, two plastidial lipoyl synthase genes from sunflower (Helianthus annuus L.) were identified (HaLIP1p1 and HaLIP1p2), sequenced and cloned in a heterologous production system (Escherichia coli). Gene expression studies revealed similar expression patterns for both isoforms, with a slight predominance of HaLIP1p1 in vegetative tissues and mature seeds. Tertiary structural models for these enzymes indicate they both have the same theoretical catalytic sites, using lipoyl-lys and 5-deoxyadenosine as docking substrates. The fatty acid profile of E. coli cells overexpressing HaLIP1p1 and HaLIP1p2 did not present major differences, and the in vivo activity of both proteins was confirmed by complementation of an E. coli JW0623 mutant in which lipoyl synthase is defective. Although no significant differences were detected in the total fatty acid composition of transgenic Arabidopsis thaliana seeds overexpressing any of both proteins, a lipidomic analysis revealed a redistribution of the glycerolipid species, accompanied with increased phosphatidylethanolamine (PE) content and a decrease in diacyglycerols (DAG) and phosphatidylcholine (PC). Depletion of the SAM co-factor caused by HaLIP1p1 and HaLIP1p2 overexpression in transgenic plants could explain this remodelling through its effects on PC synthesis.


Assuntos
Aciltransferases , Arabidopsis , Ácidos Graxos , Helianthus/genética , Proteínas de Plantas , Plantas Geneticamente Modificadas , Sulfurtransferases , Aciltransferases/biossíntese , Aciltransferases/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Ácidos Graxos/biossíntese , Ácidos Graxos/genética , Helianthus/enzimologia , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Sementes/genética , Sementes/metabolismo , Sulfurtransferases/biossíntese , Sulfurtransferases/genética
6.
Mol Cell Biochem ; 468(1-2): 83-96, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32189172

RESUMO

Vitamin B12 deficiency is a critical problem worldwide and peri-conceptional deficiency of this vitamin is associated with the risk of complex cardio-metabolic diseases. Nutritional perturbations during these stages of development may lead to changes in the fetal epigenome. Using Wistar rat model system, we have earlier shown that low maternal B12 levels are associated with low birth weight, adiposity, insulin resistance, and increased triglyceride levels in the offspring, which might predispose them to the risk of cardio-metabolic diseases in adulthood. In this study, we have investigated the effects of maternal B12 deficiency on genome-wide DNA methylation profile of the offspring and the effect of rehabilitation of mothers with B12 at conception. We have performed methylated DNA immunoprecipitation sequencing of liver from pups in four groups of Wistar rats: Control (C), B12-restricted (B12R), B12-rehabilitated at conception (B12RC), and B12-rehabilitated at parturition (B12RP). We have analyzed differentially methylated signatures between the three groups as compared to controls. We have identified a total of 214 hypermethylated and 142 hypomethylated regions in the 10 kb upstream region of transcription start site in pups of B12-deficient mothers, which are enriched in genes involved in fatty acid metabolism and mitochondrial transport/metabolism. B12 rehabilitation at conception and parturition is responsible for reversal of methylation status of many of these regions to control levels suggesting a causal association with metabolic phenotypes. Thus, maternal B12 restriction alters DNA methylation of genes involved in important metabolic processes and influences the offspring phenotype, which is reversed by B12 rehabilitation of mothers at conception.


Assuntos
Metilação de DNA , Fígado/metabolismo , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Deficiência de Vitamina B 12 , Vitamina B 12/metabolismo , Animais , Animais Recém-Nascidos , Ilhas de CpG/genética , Ácidos Graxos/genética , Ácidos Graxos/metabolismo , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Imunoprecipitação , Resistência à Insulina/genética , Masculino , Mitocôndrias/genética , Mitocôndrias/metabolismo , Obesidade/metabolismo , Fenótipo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/genética , Ratos , Ratos Wistar , Transdução de Sinais/genética
7.
Sci Rep ; 10(1): 2839, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32071421

RESUMO

The novel anti-fungal cyclic lipopeptide 'Kannurin' and its three structural variants produced by Bacillus cereus AK1 were previously reported from our laboratory. The present study reports unexplored structural variants of Kannurin those have functional benefits. Due to the difference in ß-hydroxy fatty acid tail length, they are designated here as Kannurin A (m/z 994.67 ± 0.015), B (m/z 1008.68 ± 0.017), C (m/z 1022.69 ± 0.021), D (m/z 1036.70 ± 0.01), CL (m/z 1040.71 ± 0.02) and DL (m/z 1054.72 ± 0.01). The isoform A (m/z 994.67 ± 0.015) is the shortest cyclic form of Kannurin identified so far. In addition, CL (m/z 1040.71 ± 0.02) and DL (m/z 1054.72 ± 0.01) are the rare natural linear forms. The results of the antimicrobial assays deduced that the difference in lipid tail length of the isoforms contributes tremendous differences in their antimicrobial properties. The isoforms with short lipid tails (A and B) are more selective and potent towards bacteria, whereas the isoforms with long lipid tails (C and D) are more potent against fungi. The molecular dynamics studies and electron microscopic observations supported with circular dichroic spectroscopy analysis showed the structural confirmation and formation of aggregates of Kannurin in solution. The molecular dynamics simulation studies revealed that a single molecule of Kannurin makes enormous intra-molecular interactions and structural re-arrangements to attain stable lowest energy state in solution. When they reach a particular concentration (CMC) especially in aqueous environment, tends to form structural aggregates called 'micelles'. With the structural information and activity relationship described in this study, it is trying to point out the sensitive structural entities that can be modified to improve the efficacy and target specificities of lipopeptide class of antibiotics.


Assuntos
Ácidos Graxos/química , Lipídeos/química , Lipopeptídeos/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Bacillus cereus/química , Bacillus cereus/genética , Ácidos Graxos/genética , Fungos/efeitos dos fármacos , Fungos/patogenicidade , Lipídeos/genética , Lipopeptídeos/genética , Micelas , Isoformas de Proteínas/química , Isoformas de Proteínas/genética
8.
PLoS One ; 15(2): e0226888, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32027663

RESUMO

Camellia oleifera Abel. (C. oleifera), as an important woody tree species producing edible oils in China, has attracted enormous attention due to its abundant unsaturated fatty acids and their associated benefits to human health. To reveal novel insights into the characters during the maturation period of this plant as well as the molecular basis of fatty acid biosynthesis and degradation, we conducted a conjoint analysis of the transcriptome and proteome of C. oleifera seeds from Hainan Island. Using RNA sequencing (RNA-seq) technology and shotgun proteomic method, 59,391 transcripts and 40,500 unigenes were obtained by TIGR Gene Indices Clustering Tools (TGICL), while 1691 protein species were identified from Mass Spectrometry (MS). Subsequently, all genes and proteins were employed in euKaryotic Orthologous Groups (KOG) classification, Gene Ontology (GO) annotation, and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis to investigate their essential functions. The results indicated that the most abundant pathways were biological metabolic processes. There were 946 unigenes associated with lipid metabolism at the transcriptome level, with 116 proteins at the proteome level; among these, 38 specific proteins were involved in protein-protein interactions, with the majority being related to fatty acid catabolic process. The expression levels of 21 candidate unigenes encoding target proteins were further detected by quantitative real-time polymerase chain reaction (qRT-PCR). Finally, Gas Chromatography Mass Spectrometry (GC-MS) was carried out to determine the fatty acid composition of C. oleifera oil. These findings not only deepened our understanding about the molecular mechanisms of fatty acid metabolism but also offered new evidence concerning the roles of relevant proteins in oil-bearing crops. Furthermore, the lipid-associated proteins recognized in this research might be helpful in providing a reference for the synthetic regulation of C. oleifera oil quality by genetic engineering techniques, thus resulting in potential application in agriculture.


Assuntos
Camellia/genética , Ácidos Graxos/genética , Metabolismo dos Lipídeos/genética , Proteoma/metabolismo , Sementes/genética , Transcriptoma/genética , China , Perfilação da Expressão Gênica/métodos , Ilhas , Óleos Vegetais/química , Análise de Sequência de RNA/métodos
9.
Meat Sci ; 163: 108057, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31954333

RESUMO

Semimembranosus muscle samples from 795 Large White heavy pigs were used to determine their intramuscular fatty acid composition and to estimate the heritability and the genetic correlations of these traits. Muscle fatty acids showed heritability estimates of low-to-moderate magnitude, ranging from 0.157 for total fatty acids to 0.237 for docosahexaenoic acid. Only small differences in heritability appeared among fatty acids based on their chain length, saturation and double bond position. Omega-6 polyunsaturated fatty acids showed positive genetic correlations with carcass lean % (0.563 ± 0.005) and loin thickness (0.438 ± 0.005) while being negatively related to backfat thickness measured both by calibre (-0.225 ± 0.008) and Fat-O-Meat'er (FOM) apparatus (-0.603 ± 0.004). Interestingly, the monounsaturated fatty acid class was not correlated with carcass measures and presented only a weak positive genetic correlation with intramuscular fat (0.145 ± 0.002). This result suggests that in heavy pig breeds monounsaturated fatty acids in muscle could be selected for without interfering with carcass traits.


Assuntos
Ácidos Graxos/genética , Carne de Porco/normas , Sus scrofa/genética , Tecido Adiposo , Animais , Composição Corporal/genética , Ácidos Graxos/análise , Feminino , Masculino , Músculo Esquelético/química , Carne de Porco/análise
10.
Nat Commun ; 11(1): 45, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31896749

RESUMO

Unlike protein-coding genes, the majority of human long non-coding RNAs (lncRNAs) are considered non-conserved. Although lncRNAs have been shown to function in diverse pathophysiological processes in mice, it remains largely unknown whether human lncRNAs have such in vivo functions. Here, we describe an integrated pipeline to define the in vivo function of non-conserved human lncRNAs. We first identify lncRNAs with high function potential using multiple indicators derived from human genetic data related to cardiometabolic traits, then define lncRNA's function and specific target genes by integrating its correlated biological pathways in humans and co-regulated genes in a humanized mouse model. Finally, we demonstrate that the in vivo function of human-specific lncRNAs can be successfully examined in the humanized mouse model, and experimentally validate the predicted function of an obesity-associated lncRNA, LINC01018, in regulating the expression of genes in fatty acid oxidation in humanized livers through its interaction with RNA-binding protein HuR.


Assuntos
Fígado/fisiologia , RNA Longo não Codificante/fisiologia , Animais , Sequência de Bases , Sequência Conservada , Proteína Semelhante a ELAV 1/genética , Proteína Semelhante a ELAV 1/metabolismo , Epigênese Genética , Ácidos Graxos/genética , Ácidos Graxos/metabolismo , Estudo de Associação Genômica Ampla , Hepatócitos/fisiologia , Humanos , Fígado/metabolismo , Hepatopatias/genética , Hepatopatias/metabolismo , Masculino , Metiltransferases/genética , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Obesidade/genética , Obesidade/metabolismo , Locos de Características Quantitativas
11.
Br J Cancer ; 122(2): 245-257, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31819188

RESUMO

BACKGROUND: The fatty acid (FA) composition of phosphatidylinositols (PIs) is tightly regulated in mammalian tissue since its disruption impairs normal cellular functions. We previously found its significant alteration in breast cancer by using matrix-assisted laser desorption and ionisation imaging mass spectrometry (MALDI-IMS). METHODS: We visualised the histological distribution of PIs containing different FAs in 65 primary breast cancer tissues using MALDI-IMS and investigated its association with clinicopathological features and gene expression profiles. RESULTS: Normal ductal cells (n = 7) predominantly accumulated a PI containing polyunsaturated FA (PI-PUFA), PI(18:0/20:4). PI(18:0/20:4) was replaced by PIs containing monounsaturated FA (PIs-MUFA) in all non-invasive cancer cells (n = 12). While 54% of invasive cancer cells (n = 27) also accumulated PIs-MUFA, 46% of invasive cancer cells (n = 23) accumulated the PIs-PUFA, PI(18:0/20:3) and PI(18:0/20:4). The accumulation of PI(18:0/20:3) was associated with higher incidence of lymph node metastasis and activation of the PD-1-related immune checkpoint pathway. Fatty acid-binding protein 7 was identified as a putative molecule controlling PI composition. CONCLUSIONS: MALDI-IMS identified PI composition associated with invasion and nodal metastasis of breast cancer. The accumulation of PI(18:0/20:3) could affect the PD-1-related immune checkpoint pathway, although its precise mechanism should be further validated.


Assuntos
Neoplasias da Mama/genética , Ácidos Graxos/metabolismo , Fosfatidilinositóis/metabolismo , Transcriptoma/genética , Idoso , Animais , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Ácidos Graxos/genética , Feminino , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Espectrometria de Massas , Pessoa de Meia-Idade , Fosfatidilinositóis/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
12.
Cell Prolif ; 53(1): e12705, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31657086

RESUMO

OBJECTIVES: Increasing evidences demonstrate a close correlation between epithelial-to-mesenchymal transition (EMT) induction and cancer lipid metabolism. However, the molecular mechanisms have not been clarified. MATERIALS AND METHODS: In our study, the relative expression level of PRRX1 was detected, its relationship with free fatty acid (FFA) and PPARG2 was analysed in 85 SACC tissues and 15 salivary glands from the benign salivary tumours. We also compared the FFAs composition and levels in these SACC cells. PPARG2 was detected in PRRX1-induced FFAs treatment as well as Src and MMP-9 were detected in FFAs treatment-induced invasion and migration of SACC cells, and ChIP test was performed to identify the target interactions. RESULTS: Our data showed that overexpression of PRRX1 induced EMT and facilitated the invasion and migration of SACC cells, and PRRX1 expression was closely associated with high FFAs level and poor prognosis of SACC patients. Furthermore, PRRX1 silence led to the increase of PPARG2 and the reduction of FFAs level and the migration and invasion of SACC cells. And inhibition of PPARG2 rescued FFAs level and migration and invasion capabilities of SACC cells. Free fatty acids treatment induced an increase of Stat5-DNA binding activity via Src- and MMP-9-dependent pathway. CONCLUSIONS: Collectively, our findings showed that the PRRX1/PPARG2/FFAs signalling in SACC was important for accelerating tumour metastasis through the induction of EMT and the metabolic reprogramming of FFAs.


Assuntos
Carcinoma Adenoide Cístico/metabolismo , Reprogramação Celular , Transição Epitelial-Mesenquimal , Ácidos Graxos/metabolismo , Proteínas de Homeodomínio/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias das Glândulas Salivares/metabolismo , Animais , Carcinoma Adenoide Cístico/genética , Carcinoma Adenoide Cístico/patologia , Linhagem Celular Tumoral , Ácidos Graxos/genética , Proteínas de Homeodomínio/genética , Humanos , Camundongos , Invasividade Neoplásica , Metástase Neoplásica , Proteínas de Neoplasias/genética , Neoplasias das Glândulas Salivares/genética , Neoplasias das Glândulas Salivares/patologia
13.
Plant Biotechnol J ; 18(2): 526-539, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31350932

RESUMO

The biosynthesis of very-long-chain fatty acids (VLCFAs) and their transport are required for fibre development. However, whether other regulatory factors are involved in this process is unknown. We report here that overexpression of an Arabidopsis gene ankyrin repeat-containing protein 2A (AKR2A) in cotton promotes fibre elongation. RNA-Seq analysis was employed to elucidate the mechanisms of AKR2A in regulating cotton fibre development. The VLCFA content and the ratio of VLCFAs to short-chain fatty acids increased in AKR2A transgenic lines. In addition, AKR2A promotes fibre elongation by regulating ethylene and synergizing with the accumulation of auxin and hydrogen peroxide. Analysis of RNA-Seq data indicates that AKR2A up-regulates transcript levels of genes involved in VLCFAs' biosynthesis, ethylene biosynthesis, auxin and hydrogen peroxide signalling, cell wall and cytoskeletal organization. Furthermore, AKR2A interacted with KCS1 in Arabidopsis both in vitro and in vivo. Moreover, the VLCFA content and the ratio of VLCFAs to short-chain fatty acids increased significantly in seeds of AKR2A-overexpressing lines and AKR2A/KCS1 co-overexpressing lines, while AKR2A mutants are the opposite trend. Our results uncover a novel cotton fibre growth mechanism by which the critical regulator AKR2A promotes fibre development via activating hormone signalling cascade by mediating VLCFA biosynthesis. This study provides a potential candidate gene for improving fibre yield and quality through genetic engineering.


Assuntos
Fibra de Algodão , Ácidos Graxos , Gossypium , Arabidopsis/genética , Ácidos Graxos/biossíntese , Ácidos Graxos/genética , Regulação da Expressão Gênica de Plantas/genética , Gossypium/genética , Gossypium/metabolismo , Chaperonas Moleculares/metabolismo , Transdução de Sinais/genética
14.
Biochem Biophys Res Commun ; 523(2): 429-433, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-31870547

RESUMO

Polyamines are low molecular weight, organic cations that play a critical role in many major cellular processes including cell cycle regulation and apoptosis, cellular division, tissue proliferation, and cellular differentiation; however, the functions of polyamines in regulating the storage of metabolic fuels such as triglycerides and glycogen is poorly understood. To address this question, we focused on the Drosophila homolog of ornithine decarboxylase (Odc1), the first rate-limiting enzyme in the synthesis of polyamines. Mutants in Odc1 are lethal, but heterozygotes were viable to adulthood. Odc1 heterozygotes appeared larger than their genetic background control flies and consistent with this observation, weighed more than the controls. However, the increased weight was not due to increased food consumption as heterozygotes ate less than the controls. Interestingly, Odc1 heterozygous flies had augmented triglyceride storage, and this lipid phenotype was due to increased triglyceride storage per cell and an increase in the number of fat cells produced. Odc1 heterozygous flies also displayed increased expression of the lipid synthesis genes fatty acid synthase (FASN) and acetyl-CoA carboxylase (ACC), suggesting increased lipid synthesis was the cause of the augmented triglyceride phenotype. These results provide a link between the expression of Odc1 and triglyceride storage suggesting that the polyamine pathway plays a role in regulating lipid metabolism.


Assuntos
Proteínas de Drosophila/genética , Drosophila melanogaster/metabolismo , Ornitina Descarboxilase/genética , Triglicerídeos/metabolismo , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/metabolismo , Animais , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Ácido Graxo Sintase Tipo I/genética , Ácido Graxo Sintase Tipo I/metabolismo , Ácidos Graxos/genética , Ácidos Graxos/metabolismo , Feminino , Regulação da Expressão Gênica , Heterozigoto , Mutação , Ornitina Descarboxilase/metabolismo , Triglicerídeos/genética
15.
Mol Cell Biochem ; 464(1-2): 11-20, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31677030

RESUMO

Sirtuin 3 (SIRT3) modulates mitochondria-localized processes and is implicated in the metabolic reprogramming of cancer cells, especially fatty acid (FA) synthesis. However, the relationship between SIRT3 and aberrant lipid synthesis in cervical cancer remains unclear. Here, we investigated the clinical relevance of SIRT3 expression in cervical squamous cell carcinoma (CSCC), cervical intraepithelial neoplasia (CIN), and normal tissues. To analyze the role of SIRT3 in CCSC in vitro, endogenous SIRT3 levels were up- and down-regulated in SiHa and C33a cells, respectively, via lentiviral-based transfection. Levels were quantified using qRT-PCR. Acetylation levels for acetyl-coA carboxylase (ACC1) were measured with the anti-acetyllysine antibody. Knockdown of SIRT3 reduced levels of cellular lipid content in cells. To investigate the role of SIRT3 in cell proliferation, nude mice were xenografted with SIRT3-overexpressing or SIRT3-knockdown CCSC cells. Overall, the results demonstrate that SIRT3 significantly contributed to the reprogramming of FA synthesis in CCSC by up-regulating ACC1 to promote de novo lipogenesis by SIRT3 deacetylation. Moreover, the findings show that the SIRT3-mediated regulation of FA synthesis played a critical role in the proliferation and metastasis of CCSC cells, suggesting that SIRT3 has therapeutic potential in CCSC treatment.


Assuntos
Carcinoma de Células Escamosas/enzimologia , Ácido Graxo Sintase Tipo I/metabolismo , Proteínas de Neoplasias/metabolismo , Sirtuína 3/metabolismo , Neoplasias do Colo do Útero/enzimologia , Animais , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Ácido Graxo Sintase Tipo I/genética , Ácidos Graxos/biossíntese , Ácidos Graxos/genética , Feminino , Humanos , Camundongos , Camundongos Nus , Invasividade Neoplásica , Metástase Neoplásica , Proteínas de Neoplasias/genética , Sirtuína 3/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia
16.
Antonie Van Leeuwenhoek ; 113(5): 629-641, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31828448

RESUMO

The whiA gene is widely distributed among Gram-positive bacteria. Although the encoded protein has conserved N-terminal homing endonuclease scaffold and C-terminal helix-turn-helix DNA-binding domains, whiA plays a unique physiological role in its host organisms, reflecting a long history of evolution. Here, we used genetic approaches to unveil the physiological function of whiA in Corynebacterium glutamicum. We found that cells lacking whiA (ΔwhiA) were unable to grow in minimal medium containing glucose, although reduced growth was observed in complex medium. The ΔwhiA strain showed altered transcription of the cell division genes ftsZ, sepF, ftsK, crgA, divIVA, and amiC genes. Accordingly, ΔwhiA cells exhibited large, elongated, branched, and bud-shaped morphologies. In addition, some genes, including fas-IA, fas-IB, accD1, and cmrA, which help synthesize the fatty acid and cell envelope component mycolic acid, showed altered transcription in the ΔwhiA strain. Further, treS, treY, otsA, and otsB, which are involved in the biosynthesis of the outer envelope component trehalose, were down-regulated in the ΔwhiA strain. 2D-PAGE analysis of the ΔwhiA mutant showed that proteins involved in other cellular activities were also affected by the loss of whiA. These findings suggest that C. glutamicum whiA plays a critical role in cell division, envelope formation, and general cell physiology.


Assuntos
Proteínas de Bactérias/genética , Corynebacterium glutamicum/genética , Actinomycetales , Proteínas de Bactérias/metabolismo , Divisão Celular/genética , Parede Celular/genética , Parede Celular/metabolismo , Corynebacterium glutamicum/citologia , Corynebacterium glutamicum/fisiologia , Ácidos Graxos/genética , Ácidos Graxos/metabolismo , Ácidos Micólicos/metabolismo
17.
Prog Lipid Res ; 77: 101020, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31870728

RESUMO

Obesity is featured by chronic systemic low-grade inflammation that eventually contributes to the development of insulin resistance. Toll-like receptor 4 (TLR4) is an important mediator that triggers the innate immune response by activating inflammatory signaling cascades. Human, animal and cell culture studies identified saturated fatty acids (SFAs), the dominant non-esterified fatty acid (NEFA) in the circulation of obese subjects, as non-microbial agonists that trigger the inflammatory response via activating TLR4 signaling, which acts as an important causative link between fatty acid overload, chronic low-grade inflammation and the related metabolic aberrations. The interaction between SFAs and TLR4 may be modulated through the myeloid differentiation primary response gene 88-dependent and independent signaling pathway. Greater understanding of the crosstalk between dietary SFAs and TLR4 signaling in the pathogenesis of metabolic imbalance may facilitate the design of a more efficient pharmacological strategy to alleviate the risk of developing chronic diseases elicited in part by fatty acid overload. The current review discusses recent advances in the impact of crosstalk between SFAs and TLR4 on inflammation and insulin resistance in multiple cell types, tissues and organs in the context of metabolic dysregulation.


Assuntos
Ácidos Graxos/genética , Inflamação/genética , Resistência à Insulina/genética , Receptor 4 Toll-Like/genética , Animais , Humanos , Imunidade Inata/genética , Inflamação/metabolismo , Inflamação/patologia , Obesidade/genética , Obesidade/metabolismo , Obesidade/patologia , Transdução de Sinais/genética
18.
Genes (Basel) ; 10(12)2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31805727

RESUMO

Maize is an important oil seed crop and a major food crop in different parts of the world. Since maize has relatively lower seed oil content as compared to other oil crops, efforts are continuing to improve its oil content percentage. In this study, we analyzed two contrasting maize genotypes with differential oil accumulation percentages. High oil-content (HOC) maize had 11% oil content while low oil-content (LOC) maize had significantly lower oil content (5.4%). Transmission electron microscopy revealed a higher accumulation of oil bodies in the HOC maize embryo as compared to LOC maize. Comparative RNA-sequencing analysis at different developmental stages of the seed embryos identified 739 genes that are constantly differentially expressed (DEGs) at all the six developmental stages from 15 days after pollination (DAP) to 40 DAP. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis identified fatty acid metabolism and fatty acid biosynthesis as the most enriched biological pathways contributed by these DEGs. Notably, transcriptional changes are more intense at the early stages of embryo development as compared to later stages. In addition, pathways related to oil biosynthesis and their corresponding genes were more enriched at 30 DAP, which seems to be the key stage for oil accumulation. The study also identified 33 key DEGs involved in fatty acid and triacylglycerols biosynthesis, most of which were up-regulated in HOC, that may shape the differential oil contents in the two contrasting maize. Notably, we discovered that both acyl-CoA-dependent and acyl-CoA-independent processes are essential for the high oil accumulation in maize embryo.


Assuntos
Ácidos Graxos/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Genes de Plantas , Genótipo , Sementes/genética , Zea mays/genética , Ácidos Graxos/biossíntese , Óleos Vegetais/metabolismo , Sementes/embriologia , Especificidade da Espécie , Zea mays/crescimento & desenvolvimento
19.
PLoS Genet ; 15(11): e1008375, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31738765

RESUMO

DNA variants that alter gene expression contribute to variation in many phenotypic traits. In particular, trans-acting variants, which are often located on different chromosomes from the genes they affect, are an important source of heritable gene expression variation. However, our knowledge about the identity and mechanism of causal trans-acting variants remains limited. Here, we developed a fine-mapping strategy called CRISPR-Swap and dissected three expression quantitative trait locus (eQTL) hotspots known to alter the expression of numerous genes in trans in the yeast Saccharomyces cerevisiae. Causal variants were identified by engineering recombinant alleles and quantifying the effects of these alleles on the expression of a green fluorescent protein-tagged gene affected by the given locus in trans. We validated the effect of each variant on the expression of multiple genes by RNA-sequencing. The three variants differed in their molecular mechanism, the type of genes they reside in, and their distribution in natural populations. While a missense leucine-to-serine variant at position 63 in the transcription factor Oaf1 (L63S) was almost exclusively present in the reference laboratory strain, the two other variants were frequent among S. cerevisiae isolates. A causal missense variant in the glucose receptor Rgt2 (V539I) occurred at a poorly conserved amino acid residue and its effect was strongly dependent on the concentration of glucose in the culture medium. A noncoding variant in the conserved fatty acid regulated (FAR) element of the OLE1 promoter influenced the expression of the fatty acid desaturase Ole1 in cis and, by modulating the level of this essential enzyme, other genes in trans. The OAF1 and OLE1 variants showed a non-additive genetic interaction, and affected cellular lipid metabolism. These results demonstrate that the molecular basis of trans-regulatory variation is diverse, highlighting the challenges in predicting which natural genetic variants affect gene expression.


Assuntos
Proteínas de Ligação a DNA/genética , Evolução Molecular , Sequências Reguladoras de Ácido Nucleico/genética , Proteínas de Saccharomyces cerevisiae/genética , Estearoil-CoA Dessaturase/genética , Fatores de Transcrição/genética , Sistemas CRISPR-Cas/genética , Ácidos Graxos/genética , Ácidos Graxos/metabolismo , Regulação Fúngica da Expressão Gênica/genética , Proteínas de Fluorescência Verde/genética , Metabolismo dos Lipídeos/genética , Proteínas de Transporte de Monossacarídeos/genética , Mutação de Sentido Incorreto/genética , Fenótipo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
20.
Int J Mol Sci ; 20(22)2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31703292

RESUMO

Cardiac mesenchymal stem cells (C-MSC) play a key role in maintaining normal cardiac function under physiological and pathological conditions. Glycolysis and mitochondrial oxidative phosphorylation predominately account for energy production in C-MSC. Dicer, a ribonuclease III endoribonuclease, plays a critical role in the control of microRNA maturation in C-MSC, but its role in regulating C-MSC energy metabolism is largely unknown. In this study, we found that Dicer knockout led to concurrent increase in both cell proliferation and apoptosis in C-MSC compared to Dicer floxed C-MSC. We analyzed mitochondrial oxidative phosphorylation by quantifying cellular oxygen consumption rate (OCR), and glycolysis by quantifying the extracellular acidification rate (ECAR), in C-MSC with/without Dicer gene deletion. Dicer gene deletion significantly reduced mitochondrial oxidative phosphorylation while increasing glycolysis in C-MSC. Additionally, Dicer gene deletion selectively reduced the expression of ß-oxidation genes without affecting the expression of genes involved in the tricarboxylic acid (TCA) cycle or electron transport chain (ETC). Finally, Dicer gene deletion reduced the copy number of mitochondrially encoded 1,4-Dihydronicotinamide adenine dinucleotide (NADH): ubiquinone oxidoreductase core subunit 6 (MT-ND6), a mitochondrial-encoded gene, in C-MSC. In conclusion, Dicer gene deletion induced a metabolic shift from oxidative metabolism to aerobic glycolysis in C-MSC, suggesting that Dicer functions as a metabolic switch in C-MSC, which in turn may regulate proliferation and environmental adaptation.


Assuntos
RNA Helicases DEAD-box/metabolismo , Ácidos Graxos/metabolismo , Células-Tronco Mesenquimais/enzimologia , Mitocôndrias Cardíacas/metabolismo , Miocárdio/enzimologia , Ribonuclease III/metabolismo , Animais , Ciclo do Ácido Cítrico , RNA Helicases DEAD-box/genética , Complexo de Proteínas da Cadeia de Transporte de Elétrons/genética , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Ácidos Graxos/genética , Deleção de Genes , Glicólise , Humanos , Camundongos , Mitocôndrias Cardíacas/genética , Oxirredução , RNA de Transferência de Treonina , Ribonuclease III/genética
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