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1.
Genes Cells ; 29(4): 347-355, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38351722

RESUMO

CdsA is a CDP-diacylglycerol synthase essential for phospholipid and glycolipid MPIase biosynthesis, and therefore for growth. The initiation codon of CdsA has been assigned as "TTG," while methionine at the 37th codon was reported to be an initiation codon in the original report. Since a vector containing the open reading frame starting with "TTG" under a controllable promoter complemented the cdsA knockout, "TTG" could function as an initiation codon. However, no evidence supporting that this "TTG" is the sole initiation codon has been reported. We determined the initiation codon by examining the ability of mutants around the N-terminal region to complement cdsA mutants. Even if the "TTG" was substituted with a stop codon, the clear complementation was observed. Moreover, the clones with multiple mutations of stop codons complemented the cdsA mutant up to the 37th codon, indicating that cdsA possesses multiple codons that can function as initiation codons. We constructed an experimental system in which the chromosomal expression of cdsA can be analyzed. By means of this system, we found that the cdsA mutant with substitution of "TTG" with a stop codon is fully functional. Thus, we concluded that CdsA contains multiple initiation codons.


Assuntos
Diacilglicerol Colinofosfotransferase , Glicolipídeos , Fosfolipídeos , Diacilglicerol Colinofosfotransferase/metabolismo , Códon de Iniciação/genética , Códon de Terminação/genética , Biossíntese de Proteínas
2.
FEMS Microbiol Lett ; 3702023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-38070879

RESUMO

YnbB is a paralogue of CdsA, a CDP-diacylglycerol synthase. While the cdsA gene is essential, the ynbB gene is dispensable. So far, no phenotype of ynbB knockout has been observed. We found that a ynbB knockout strain acquired cold-sensitivity on growth under CdsA-limited conditions. We found that MPIase, a glycolipid involved in protein export, is cold-upregulated to facilitate protein export in the cold, by increasing the mRNA levels of not only CdsA but also that of YnbB. Under non-permissive conditions, phospholipid biosynthesis proceeded normally, however, MPIase upregulation was inhibited with accumulation of precursors of membrane and secretory proteins such as M13 procoat and proOmpA, indicating that YnbB is dedicated to MPIase biosynthesis, complementing the CdsA function.


Assuntos
Diacilglicerol Colinofosfotransferase , Proteínas de Membrana , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Diacilglicerol Colinofosfotransferase/genética , Diacilglicerol Colinofosfotransferase/metabolismo , Diglicerídeos de Citidina Difosfato , Regulação para Cima , Glicolipídeos/metabolismo
3.
Trends Plant Sci ; 28(12): 1344-1346, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37648632

RESUMO

Lesion mimic mutations (LMMs) often confer broad-spectrum resistance (BSR) in plants, but with significant yield penalties. Sha et al. recently demonstrated that genome editing of the rice BSR gene RESISTANCE TO BLAST1 (RBL1), encoding a cytidine diphosphate diacylglycerol (CDP-DAG) synthase involved in phospholipid biosynthesis, confers multipathogen resistance without an obvious trade-off in yield.


Assuntos
Diacilglicerol Colinofosfotransferase , Oryza , Diacilglicerol Colinofosfotransferase/genética , Oryza/genética , Cistina Difosfato , Diglicerídeos , Mutação/genética
4.
Nature ; 618(7967): 1017-1023, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37316672

RESUMO

The discovery and application of genome editing introduced a new era of plant breeding by giving researchers efficient tools for the precise engineering of crop genomes1. Here we demonstrate the power of genome editing for engineering broad-spectrum disease resistance in rice (Oryza sativa). We first isolated a lesion mimic mutant (LMM) from a mutagenized rice population. We then demonstrated that a 29-base-pair deletion in a gene we named RESISTANCE TO BLAST1 (RBL1) caused broad-spectrum disease resistance and showed that this mutation caused an approximately 20-fold reduction in yield. RBL1 encodes a cytidine diphosphate diacylglycerol synthase that is required for phospholipid biosynthesis2. Mutation of RBL1 results in reduced levels of phosphatidylinositol and its derivative phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2). In rice, PtdIns(4,5)P2 is enriched in cellular structures that are specifically associated with effector secretion and fungal infection, suggesting that it has a role as a disease-susceptibility factor3. By using targeted genome editing, we obtained an allele of RBL1, named RBL1Δ12, which confers broad-spectrum disease resistance but does not decrease yield in a model rice variety, as assessed in small-scale field trials. Our study has demonstrated the benefits of editing an LMM gene, a strategy relevant to diverse LMM genes and crops.


Assuntos
Diacilglicerol Colinofosfotransferase , Resistência à Doença , Edição de Genes , Oryza , Melhoramento Vegetal , Doenças das Plantas , Resistência à Doença/genética , Edição de Genes/métodos , Genoma de Planta/genética , Oryza/enzimologia , Oryza/genética , Oryza/microbiologia , Fosfatidilinositóis/metabolismo , Melhoramento Vegetal/métodos , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Alelos , Fosfatidilinositol 4,5-Difosfato/metabolismo , Diacilglicerol Colinofosfotransferase/genética , Diacilglicerol Colinofosfotransferase/metabolismo
5.
Nat Commun ; 14(1): 2753, 2023 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-37179328

RESUMO

Phosphatidylcholine (PC) is the most abundant phospholipid in eukaryotic cell membranes. In eukaryotes, two highly homologous enzymes, cholinephosphotransferase-1 (CHPT1) and choline/ethanolamine phosphotransferase-1 (CEPT1) catalyze the final step of de novo PC synthesis. CHPT1/CEPT1 joins two substrates, cytidine diphosphate-choline (CDP-choline) and diacylglycerol (DAG), to produce PC, and Mg2+ is required for the reaction. However, mechanisms of substrate recognition and catalysis remain unresolved. Here we report structures of a CHPT1 from Xenopus laevis (xlCHPT1) determined by cryo-electron microscopy to an overall resolution of ~3.2 Å. xlCHPT1 forms a homodimer, and each protomer has 10 transmembrane helices (TMs). The first 6 TMs carve out a cone-shaped enclosure in the membrane in which the catalysis occurs. The enclosure opens to the cytosolic side, where a CDP-choline and two Mg2+ are coordinated. The structures identify a catalytic site unique to eukaryotic CHPT1/CEPT1 and suggest an entryway for DAG. The structures also reveal an internal pseudo two-fold symmetry between TM3-6 and TM7-10, and suggest that CHPT1/CEPT1 may have evolved from their distant prokaryotic ancestors through gene duplication.


Assuntos
Diacilglicerol Colinofosfotransferase , Células Eucarióticas , Diacilglicerol Colinofosfotransferase/metabolismo , Células Eucarióticas/metabolismo , Microscopia Crioeletrônica , Fosfotransferases/metabolismo , Citidina Difosfato Colina/metabolismo , Fosfatidilcolinas/metabolismo , Saccharomyces cerevisiae/metabolismo , Catálise
6.
Plant J ; 114(2): 338-354, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36789486

RESUMO

Cytidine diphosphate diacylglycerol (CDP-DAG), an important intermediate for glycerolipid biosynthesis, is synthesized under the catalytic activity of CDP-DAG synthase (CDS) to produce anionic phosphoglycerolipids such as phosphatidylglycerol (PG) and cardiolipin (CL). Previous studies showed that Arabidopsis CDSs are encoded by a small gene family, termed CDS1-CDS5, the members of which are integral membrane proteins in endoplasmic reticulum (ER) and in plastids. However, the details on how CDP-DAG is provided for mitochondrial membrane-specific phosphoglycerolipids are missing. Here we present the identification of a mitochondrion-specific CDS, designated CDS6. Enzymatic activity of CDS6 was demonstrated by the complementation of CL synthesis in the yeast CDS-deficient tam41Δ mutant. The Arabidopsis cds6 mutant lacking CDS6 activity showed decreased mitochondrial PG and CL biosynthesis capacity, a severe growth deficiency finally leading to plant death. These defects were rescued partly by complementation with CDS6 or supplementation with PG and CL. The ultrastructure of mitochondria in cds6 was abnormal, missing the structures of cristae. The degradation of triacylglycerol (TAG) in lipid droplets and starch in chloroplasts in the cds6 mutant was impaired. The expression of most differentially expressed genes involved in the mitochondrial electron transport chain was upregulated, suggesting an energy-demanding stage in cds6. Furthermore, the contents of polar glycerolipids in cds6 were dramatically altered. In addition, cds6 seedlings lost the capacity for cell proliferation and showed a higher oxidase activity. Thus, CDS6 is indispensable for the biosynthesis of PG and CL in mitochondria, which is critical for establishing mitochondrial structure, TAG degradation, energy production and seedling development.


Assuntos
Arabidopsis , Arabidopsis/metabolismo , Glicogênio Sintase/metabolismo , Cistina Difosfato/metabolismo , Diglicerídeos/metabolismo , Diacilglicerol Colinofosfotransferase/metabolismo , Mitocôndrias/metabolismo , Fosfatidilgliceróis/metabolismo , Saccharomyces cerevisiae/metabolismo
7.
Sci Bull (Beijing) ; 67(3): 299-314, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36546079

RESUMO

Nonalcoholic fatty liver disease (NAFLD) encompasses a spectrum of pathologies, ranging from steatosis to nonalcoholic steatohepatitis (NASH). The factors promoting the progression of steatosis to NASH are still unclear. Recent studies suggest that mitochondrial lipid composition is critical in NASH development. Here, we showed that CDP-DAG synthase 2 (Cds2) was downregulated in genetic or diet-induced NAFLD mouse models. Liver-specific deficiency of Cds2 provoked hepatic steatosis, inflammation and fibrosis in five-week-old mice. CDS2 is enriched in mitochondria-associated membranes (MAMs), and hepatic Cds2 deficiency impaired mitochondrial function and decreased mitochondrial PE levels. Overexpression of phosphatidylserine decarboxylase (PISD) alleviated the NASH-like phenotype in Cds2f/f;AlbCre mice and abnormal mitochondrial morphology and function caused by CDS2 deficiency in hepatocytes. Additionally, dietary supplementation with an agonist of peroxisome proliferator-activated receptor alpha (PPARα) attenuated mitochondrial defects and ameliorated the NASH-like phenotype in Cds2f/f;AlbCre mice. Finally, Cds2 overexpression protected against high-fat diet-induced hepatic steatosis and obesity. Thus, Cds2 modulates mitochondrial function and NASH development.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Camundongos , Diacilglicerol Colinofosfotransferase , Dieta Hiperlipídica , Fibrose , Mitocôndrias/patologia , Hepatopatia Gordurosa não Alcoólica/genética
8.
Int J Mol Sci ; 23(18)2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36142650

RESUMO

Phospholipids (PLs) are a class of lipids with many proven biological functions. They are commonly used in lipid replacement therapy to enrich cell membranes damaged in chronic neurodegenerative diseases, cancer, or aging processes. Due to their amphipathic nature, PLs have been widely used in food, cosmetic, and pharmaceutical products as natural emulsifiers and components of liposomes. In Yarrowia lipolytica, PLs are synthesized through a similar pathway like in higher eukaryotes. However, PL biosynthesis in this yeast is still poorly understood. The key intermediate in this pathway is phosphatidic acid, which in Y. lipolytica is mostly directed to the production of triacylglycerols and, in a lower amount, to PL. This study aimed to deliver a strain with improved PL production, with a particular emphasis on increased biosynthesis of phosphatidylcholine (PC). Several genetic modifications were performed: overexpression of genes from PL biosynthesis pathways as well as the deletion of genes responsible for PL degradation. The best performing strain (overexpressing CDP-diacylglycerol synthase (CDS) and phospholipid methyltransferase (OPI3)) reached 360% of PL improvement compared to the wild-type strain in glucose-based medium. With the substitution of glucose by glycerol, a preferred carbon source by Y. lipolytica, an almost 280% improvement of PL was obtained by transformant overexpressing CDS, OPI3, diacylglycerol kinase (DGK1), and glycerol kinase (GUT1) in comparison to the wild-type strain. To further increase the amount of PL, the optimization of culture conditions, followed by the upscaling to a 2 L bioreactor, were performed. Crude glycerol, being a cheap and renewable substrate, was used to reduce the costs of PL production. In this process 653.7 mg/L of PL, including 352.6 mg/L of PC, was obtained. This study proved that Y. lipolytica is an excellent potential producer of phospholipids, especially from waste substrates.


Assuntos
Yarrowia , Carbono/metabolismo , Diacilglicerol Colinofosfotransferase/metabolismo , Diacilglicerol Quinase/metabolismo , Glucose/metabolismo , Glicerol/metabolismo , Glicerol Quinase/metabolismo , Lipossomos/metabolismo , Ácidos Fosfatídicos/metabolismo , Fosfatidil-N-Metiletanolamina N-Metiltransferase/metabolismo , Fosfatidilcolinas/metabolismo , Triglicerídeos/metabolismo , Yarrowia/genética , Yarrowia/metabolismo
9.
Plant Physiol ; 189(4): 2001-2014, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35522031

RESUMO

Castor bean (Ricinus communis) seed oil (triacylglycerol [TAG]) is composed of ∼90% of the industrially important ricinoleoyl (12-hydroxy-9-octadecenoyl) groups. Here, phosphatidylcholine (PC):diacylglycerol (DAG) cholinephosphotransferase (PDCT) from castor bean was biochemically characterized and compared with camelina (Camelina sativa) PDCT. DAGs with ricinoleoyl groups were poorly used by Camelina PDCT, and their presence inhibited the utilization of DAG with "common" acyl groups. In contrast, castor PDCT utilized DAG with ricinoleoyl groups similarly to DAG with common acyl groups and showed a 10-fold selectivity for DAG with one ricinoleoyl group over DAG with two ricinoleoyl groups. Castor DAG acyltransferase2 specificities and selectivities toward different DAG and acyl-CoA species were assessed and shown to not acylate DAG without ricinoleoyl groups in the presence of ricinoleoyl-containing DAG. Eighty-five percent of the DAG species in microsomal membranes prepared from developing castor endosperm lacked ricinoleoyl groups. Most of these species were predicted to be derived from PC, which had been formed by PDCT in exchange with DAG with one ricinoleoyl group. A scheme of the function of PDCT in castor endosperm is proposed where one ricinoleoyl group from de novo-synthesized DAG is selectivity transferred to PC. Nonricinoleate DAG is formed and ricinoleoyl groups entering PC are re-used either in de novo synthesis of DAG with two ricinoleoyl groups or in direct synthesis of triricinoleoyl TAG by PDAT. The PC-derived DAG is not used in TAG synthesis but is proposed to serve as a substrate in membrane lipid biosynthesis during oil deposition.


Assuntos
Brassicaceae , Óleo de Rícino , Diacilglicerol Colinofosfotransferase , Diglicerídeos , Fosfatidilcolinas , Ricinus/genética , Sementes , Triglicerídeos
10.
J Biochem ; 171(4): 429-441, 2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-34964897

RESUMO

Translocator assembly and maintenance 41 (Tam41) catalyses the synthesis of cytidine diphosphate diacylglycerol (CDP-DAG), which is a high-energy intermediate phospholipid critical for generating cardiolipin in mitochondria. Although Tam41 is present almost exclusively in eukaryotic cells, a Firmicutes bacterium contains the gene encoding Tam41-type CDP-DAG synthase (FbTam41). FbTam41 converted phosphatidic acid (PA) to CDP-DAG using a ternary complex mechanism in vitro. Additionally, FbTam41 functionally substituted yeast Tam41 in vivo. These results demonstrate that Tam41-type CDP-DAG synthase functions in some prokaryotic cells. We determined the crystal structure of FbTam41 lacking the C-terminal 18 residues in the cytidine triphosphate (CTP)-Mg2+ bound form at a resolution of 2.6 Å. The crystal structure showed that FbTam41 contained a positively charged pocket that specifically accommodated CTP-Mg2+ and PA in close proximity. By using this structure, we constructed a model for the full-length structure of FbTam41 containing the last a-helix, which was missing in the crystal structure. Based on this model, we propose a molecular mechanism for CDP-DAG synthesis in bacterial cells and mitochondria.


Assuntos
Cistina Difosfato , Diacilglicerol Colinofosfotransferase , Cardiolipinas , Diacilglicerol Colinofosfotransferase/genética , Diacilglicerol Colinofosfotransferase/metabolismo , Diglicerídeos , Firmicutes/metabolismo
11.
Nat Commun ; 12(1): 6877, 2021 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-34824276

RESUMO

AGPATs (1-acylglycerol-3-phosphate O-acyltransferases) catalyze the acylation of lysophosphatidic acid to form phosphatidic acid (PA), a key step in the glycerol-3-phosphate pathway for the synthesis of phospholipids and triacylglycerols. AGPAT2 is the only AGPAT isoform whose loss-of-function mutations cause a severe form of human congenital generalized lipodystrophy. Paradoxically, AGPAT2 deficiency is known to dramatically increase the level of its product, PA. Here, we find that AGPAT2 deficiency impairs the biogenesis and growth of lipid droplets. We show that AGPAT2 deficiency compromises the stability of CDP-diacylglycerol (DAG) synthases (CDSs) and decreases CDS activity in both cell lines and mouse liver. Moreover, AGPAT2 and CDS1/2 can directly interact and form functional complexes, which promote the metabolism of PA along the CDP-DAG pathway of phospholipid synthesis. Our results provide key insights into the regulation of metabolic flux during lipid synthesis and suggest substrate channelling at a major branch point of the glycerol-3-phosphate pathway.


Assuntos
Aciltransferases/metabolismo , Diglicerídeos de Citidina Difosfato/metabolismo , Diacilglicerol Colinofosfotransferase/metabolismo , Ácidos Graxos/metabolismo , Aciltransferases/deficiência , Animais , Vias Biossintéticas , Linhagem Celular , Diacilglicerol Colinofosfotransferase/deficiência , Humanos , Gotículas Lipídicas/metabolismo , Lipogênese , Fígado/metabolismo , Camundongos , Complexos Multienzimáticos , Ácido Oleico/metabolismo , Ácidos Fosfatídicos/metabolismo
12.
Lipids ; 56(6): 591-602, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34463366

RESUMO

Phosphatidylcholine:diacylglycerol cholinephosphotransferases (PDCT) regulate the fatty acid composition of seed oil (triacylglycerol, TAG) by interconversion of diacylglycerols (DAG) and phosphatidylcholine (PtdCho). PtdCho is the substrate for polyunsaturated fatty acid biosynthesis, as well as for a number of unusual fatty acids. By the action of PDCT, these fatty acids can be transferred into the DAG pool to be utilized in TAG biosynthesis by the action of acyl-CoA:DAG and phospholipid:diacylglycerol acyltransferases. Despite its importance in regulating seed oil composition, biochemical characterization of PDCT enzymes has been lacking. We characterized Camelina sativa PDCT in microsomal preparations of a yeast strain expressing Camelina PDCT and lacking the capacity of producing TAG. Camelina PDCT was specific for PtdCho and the sn-1,2 enantiomer of DAG and could not utilize ceramide. The interconversion reaches equilibrium within 15 min of incubation, indicating that only distinct pools of DAG and PtdCho were available for exchange. However, the pool sizes of DAG and PtdCho involved in the exchange were not fixed but increased with the amount of exogenous DAG or PtdCho added. Camelina PDCT showed about the same selectivity for di-oleoyl, di-linoleoyl, and di-linolenoyl species in both PtdCho and DAG substrates, suggesting that no unidirectional transfer of particular unsaturated substrates occurred. Camelina PDCT had a good activity with erucoyl-DAG as a substrate despite low erucic acid levels in PtdCho in plant species accumulating a high amount of this fatty acid in the seed oil.


Assuntos
Brassicaceae , Diacilglicerol Colinofosfotransferase , Catálise , Ácidos Graxos , Fosfatidilcolinas , Sementes , Triglicerídeos
13.
J Lipid Res ; 62: 100100, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34331935

RESUMO

Choline phospholipids (PLs) such as phosphatidylcholine (PC) and 1-alkyl-2-acyl-sn-glycerophosphocholine are important components for cell membranes and also serve as a source of several lipid mediators. These lipids are biosynthesized in mammals in the final step of the CDP-choline pathway by the choline phosphotransferases choline phosphotransferase 1 (CPT1) and choline/ethanolamine phosphotransferase 1 (CEPT1). However, the contributions of these enzymes to the de novo biosynthesis of lipids remain unknown. Here, we established and characterized CPT1- and CEPT1-deficient human embryonic kidney 293 cells. Immunohistochemical analyses revealed that CPT1 localizes to the trans-Golgi network and CEPT1 to the endoplasmic reticulum. Enzyme assays and metabolic labeling with radiolabeled choline demonstrated that loss of CEPT1 dramatically decreases choline PL biosynthesis. Quantitative PCR and reintroduction of CPT1 and CEPT1 revealed that the specific activity of CEPT1 was much higher than that of CPT1. LC-MS/MS analysis of newly synthesized lipid molecular species from deuterium-labeled choline also showed that these enzymes have similar preference for the synthesis of PC molecular species, but that CPT1 had higher preference for 1-alkyl-2-acyl-sn-glycerophosphocholine with PUFA than did CEPT1. The endogenous level of PC was not reduced by the loss of these enzymes. However, several 1-alkyl-2-acyl-sn-glycerophosphocholine molecular species were reduced in CPT1-deficient cells and increased in CEPT1-deficient cells when cultured in 0.1% FBS medium. These results suggest that CEPT1 accounts for most choline PL biosynthesis activity, and that both enzymes are responsible for the production of different lipid molecular species in distinct organelles.


Assuntos
Colina/biossíntese , Diacilglicerol Colinofosfotransferase/metabolismo , Fosfolipídeos/biossíntese , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo , Células Cultivadas , Células HEK293 , Humanos
14.
Genes Cells ; 26(9): 727-738, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34166546

RESUMO

CDP-diacylglycerol synthases (Cds) are conserved from bacteria to eukaryotes. Bacterial CdsA is involved not only in phospholipid biosynthesis but also in biosynthesis of glycolipid MPIase, an essential glycolipid that catalyzes membrane protein integration. We found that both Cds4 and Cds5 of Arabidopsis chloroplasts complement cdsA knockout by supporting both phospholipid and MPIase biosyntheses. Comparison of the sequences of CdsA and Cds4/5 suggests a difference in membrane topology at the C-termini, since the region assigned as the last transmembrane region of CdsA, which follows the conserved cytoplasmic domain, is missing in Cds4/5. Deletion of the C-terminal region abolished the function, indicating the importance of the region. Both 6 × His tag attachment to CdsA and substitution of the C-terminal 6 residues with 6 × His did not affect the function. These 6 × His tags were sensitive to protease added from the cytosolic side in vitro, indicating that this region is not a transmembrane one but forms a membrane-embedded reentrant loop. Thus, the C-terminal region of Cds homologues forms a reentrant loop, of which structure is important for the Cds function.


Assuntos
Proteínas de Arabidopsis/química , Cloroplastos/genética , Diacilglicerol Colinofosfotransferase/química , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Membrana Celular/química , Membrana Celular/metabolismo , Cloroplastos/metabolismo , Diacilglicerol Colinofosfotransferase/genética , Diacilglicerol Colinofosfotransferase/metabolismo , Escherichia coli , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Teste de Complementação Genética , Domínios Proteicos
15.
Exp Mol Med ; 53(1): 81-90, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33408336

RESUMO

In cancer cells, metabolic pathways are reprogrammed to promote cell proliferation and growth. While the rewiring of central biosynthetic pathways is being extensively studied, the dynamics of phospholipids in cancer cells are still poorly understood. In our study, we sought to evaluate de novo biosynthesis of glycerophospholipids (GPLs) in ex vivo lung cancer explants and corresponding normal lung tissue from six patients by utilizing a stable isotopic labeling approach. Incorporation of fully 13C-labeled glucose into the backbone of phosphatidylethanolamine (PE), phosphatidylcholine (PC), and phosphatidylinositol (PI) was analyzed by liquid chromatography/mass spectrometry. Lung cancer tissue showed significantly elevated isotopic enrichment within the glycerol backbone of PE, normalized to its incorporation into PI, compared to that in normal lung tissue; however, the size of the PE pool normalized to the size of the PI pool was smaller in tumor tissue. These findings indicate enhanced PE turnover in lung cancer tissue. Elevated biosynthesis of PE in lung cancer tissue was supported by enhanced expression of the PE biosynthesis genes ETNK2 and EPT1 and decreased expression of the PC and PI biosynthesis genes CHPT1 and CDS2, respectively, in different subtypes of lung cancer in publicly available datasets. Our study demonstrates that incorporation of glucose-derived carbons into the glycerol backbone of GPLs can be monitored to study phospholipid dynamics in tumor explants and shows that PE turnover is elevated in lung cancer tissue compared to normal lung tissue.


Assuntos
Neoplasias Pulmonares/metabolismo , Pulmão/metabolismo , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/metabolismo , Fosfatidilinositóis/metabolismo , Idoso , Idoso de 80 Anos ou mais , Diacilglicerol Colinofosfotransferase/genética , Diacilglicerol Colinofosfotransferase/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo
16.
Aging (Albany NY) ; 12(24): 25304-25318, 2020 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-33234734

RESUMO

OBJECTIVE: To identify novel prognostic biomarkers in renal cell carcinoma (RCC). RESULTS: 12 coding genes and one miRNA were finally identified as prognostic biomarkers. All of them were related to a poor prognosis. Lower expression levels of the coding genes were observed in higher clinical stages. Prognostic signatures including 7 biomarkers were identified. Patients in the high-risk group had worse survival than those in the low-risk group. The areas under the curves in different years indicated that it was a valuable signature in prognosis. It was found that elevated WDR72 inhibited the survival and invasion of 786-O and 769P cells in vitro. CONCLUSIONS: Thirteen prognostic biomarkers of RCC were identified. Among them, 7 biomarkers comprised a signature to evaluate the RCC prognosis. WDR72 was a cancer suppressor and a potential therapeutic target in RCC. METHODS: Differentially expressed genes/miRNAs (DEGs/DEMs) and prognosis-related genes/miRNAs were acquired from public database. Prognostic biomarkers were identified by overlapping the significant DEGs/DEMs and prognosis-related genes/miRNAs. The associations between these biomarkers and the clinical stages were analyzed. All of these prognostic biomarkers were further investigated with multi-variable Cox regression. Finally, the inhibitory effect of WDR72 on the growth and invasion of RCC cells was studied.


Assuntos
Carcinoma de Células Renais/genética , Neoplasias Renais/genética , Transcriptoma , 3-Hidroxiacil-CoA Desidrogenases/genética , Aldeído Oxirredutases/genética , Carcinoma de Células Renais/mortalidade , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Claudinas/genética , Bases de Dados Genéticas , Diacilglicerol Colinofosfotransferase/genética , Intervalo Livre de Doença , Endodesoxirribonucleases/genética , Células HEK293 , Humanos , Neoplasias Renais/mortalidade , Neoplasias Renais/patologia , MicroRNAs/genética , Invasividade Neoplásica , Prognóstico , Modelos de Riscos Proporcionais , Proteínas/genética , Taxa de Sobrevida
17.
Oncogene ; 39(42): 6556-6571, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32917955

RESUMO

Next generation antiandrogens such as enzalutamide (Enz) are effective initially for the treatment of castration-resistant prostate cancer (CRPC). However, the disease often relapses and the underlying mechanisms remain elusive. By performing H3-lysine-27 acetylation (H3K27ac) ChIP-seq in Enz-resistant CRPC cells, we identified a group of super enhancers (SEs) that are abnormally activated in Enz-resistant CRPC cells and associated with enhanced transcription of a subset of tumor promoting genes such as CHPT1, which catalyzes phosphatidylcholine (PtdCho) synthesis and regulates choline metabolism. Increased CHPT1 conferred CRPC resistance to Enz in vitro and in mice. While androgen receptor (AR) primarily binds to a putative CHPT1 enhancer and mediates androgen-dependent expression of CHPT1 gene in Enz-sensitive prostate cancer cells, AR binds to a different enhancer within the CHPT1 SE locus and facilities androgen-independent expression of CHPT1 in Enz-resistant cells. We further identified a long-non coding RNA transcribed at CHPT1 enhancer (also known as enhancer RNA) that binds to the H3K27ac reader BRD4 and participates in regulating CHPT1 SE activity and CHPT1 gene expression. Our findings demonstrate that aberrantly activated SE upregulates CHPT1 expression and confers Enz resistance in CRPC, suggesting that SE-mediated expression of downstream effectors such as CHPT1 can be viable targets to overcome Enz resistance in PCa.


Assuntos
Antagonistas de Androgênios/farmacologia , Colina Quinase/genética , Diacilglicerol Colinofosfotransferase/genética , Resistencia a Medicamentos Antineoplásicos/genética , Fosfatidilcolinas/biossíntese , Neoplasias de Próstata Resistentes à Castração/terapia , Receptores Androgênicos/metabolismo , Antagonistas de Androgênios/uso terapêutico , Androgênios/metabolismo , Animais , Benzamidas , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Quimioterapia Adjuvante/métodos , Colina Quinase/metabolismo , Sequenciamento de Cromatina por Imunoprecipitação , Diacilglicerol Colinofosfotransferase/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Elementos Facilitadores Genéticos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Nitrilas , Feniltioidantoína/análogos & derivados , Feniltioidantoína/farmacologia , Feniltioidantoína/uso terapêutico , Próstata/patologia , Prostatectomia , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , RNA Longo não Codificante/genética , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Nat Commun ; 11(1): 1204, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32139674

RESUMO

Anti-angiogenic therapies have generated significant interest for their potential to combat tumor growth. However, tumor overproduction of pro-angiogenic ligands can overcome these therapies, hampering success of this approach. To circumvent this problem, we target the resynthesis of phosphoinositides consumed during intracellular transduction of pro-angiogenic signals in endothelial cells (EC), thus harnessing the tumor's own production of excess stimulatory ligands to deplete adjacent ECs of the capacity to respond to these signals. Using zebrafish and human endothelial cells in vitro, we show ECs deficient in CDP-diacylglycerol synthase 2 are uniquely sensitive to increased vascular endothelial growth factor (VEGF) stimulation due to a reduced capacity to re-synthesize phosphoinositides, including phosphatidylinositol-(4,5)-bisphosphate (PIP2), resulting in VEGF-exacerbated defects in angiogenesis and angiogenic signaling. Using murine tumor allograft models, we show that systemic or EC specific suppression of phosphoinositide recycling results in reduced tumor growth and tumor angiogenesis. Our results suggest inhibition of phosphoinositide recycling provides a useful anti-angiogenic approach.


Assuntos
Inibidores da Angiogênese/farmacologia , Endotélio Vascular/metabolismo , Fosfatidilinositóis/metabolismo , Fatores de Crescimento do Endotélio Vascular/metabolismo , Aloenxertos/efeitos dos fármacos , Animais , Bovinos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Diacilglicerol Colinofosfotransferase/deficiência , Diacilglicerol Colinofosfotransferase/metabolismo , Endotélio Vascular/efeitos dos fármacos , Deleção de Genes , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Camundongos Knockout , Modelos Biológicos , Neovascularização Fisiológica/efeitos dos fármacos , Especificidade de Órgãos , Transdução de Sinais , Peixe-Zebra
19.
Pediatr Neonatol ; 61(3): 318-324, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31964590

RESUMO

BACKGROUND: The study of genetic polymorphisms of surfactant-lipids related genes can help to understand individual variability in the susceptibility to development of pulmonary pathologies. The purpose of this study was to evaluate the association of polymorphisms of surfactant-lipids related genes (LPCAT1, CHPT1 and PCYT1B) with the risk/severity of respiratory distress syndrome (RDS) in preterm neonates among the Chinese Han population in Southern China. METHODS: Four hundred and forty-six preterm neonates were enrolled in a case-control study. Six polymorphisms of 3 genes were analyzed by PCR amplification of genomic DNA and genotyping was performed using an improved multiplex ligation detection reaction (iMLDR) technique based on LDR. RESULTS: The GG genotype and G allele of LPCAT1-rs9728 were found less frequently in the RDS group than in the controls (11.5% vs. 22.0% and 38.3% vs. 48.2%, respectively) (p < 0.05). CONCLUSION: This report is the first study to evaluate a direct genetic association between polymorphisms of LPCAT1 and RDS development in Chinese Han preterm infants. Our study raises the possibility that a genetic variation of LPCAT1 could be implicated in the pathophysiology of RDS in preterm neonates. GG genotype and G allele of rs9728 are protective factors for the development of RDS in preterm infants.


Assuntos
1-Acilglicerofosfocolina O-Aciltransferase/genética , Colina-Fosfato Citidililtransferase/genética , Diacilglicerol Colinofosfotransferase/genética , Polimorfismo Genético , Síndrome do Desconforto Respiratório do Recém-Nascido/genética , Estudos de Casos e Controles , China/etnologia , Feminino , Predisposição Genética para Doença , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Síndrome do Desconforto Respiratório do Recém-Nascido/etiologia
20.
Hum Cell ; 33(2): 427-436, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31898195

RESUMO

CIC-DUX4 sarcoma (CDS), an aggressive soft tissue sarcoma, is characterized by a CIC and DUX4 rearrangement. It has a dismal clinical course and high metastatic rate and shows chemotherapy resistance; therefore, a novel therapeutic strategy is required. Patient-derived cell lines are indispensable tools for basic and preclinical research. However, only a few patient-derived CDS cell lines have been currently reported. Therefore, in this study, we aimed to establish and characterize a novel cell line of CDS. We successfully established the NCC-CDS2-C1 cell line by using surgically resected tumor tissue from a patient with CDS. The NCC-CDS2-C1 cells harbored a CIC-DUX4 fusion gene without insertion and exhibited rapid growth, spheroid formation, and invasion. We screened the antiproliferative effects of small anticancer agent compounds, which included FDA-approved anticancer drugs, on NCC-CDS2-C1 cells in comparison with those on the two previously reported patient-derived CDS cell lines, NCC-CDS1-X1-C1 and NCC-CDS1-X3-C1. The response profile of NCC-CDS2-C1 was similar to but distinct from those of the other cell lines for the small anticancer agent compounds. Therefore, we conclude that the NCC-CDS2-C1 cell line will be a useful tool for basic and preclinical studies of CDS.


Assuntos
Linhagem Celular Tumoral , Proteínas de Fusão Oncogênica , Sarcoma/genética , Antineoplásicos/farmacologia , Diacilglicerol Colinofosfotransferase , Humanos , Proteínas de Fusão Oncogênica/genética , Sarcoma/tratamento farmacológico , Sarcoma/patologia
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