Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.354
Filtrar
1.
Fitoterapia ; 139: 104393, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31669721

RESUMO

The extract of Dioscorea zingiberensis C.H. Wright rhizomes is found to be effective in the therapy of cardiovascular disease. Steroidal saponins make substantial contribution. Previous study has proposed that methylprotodioscin (MP) may promote cholesterol efflux by increasing ABCA1 expression. But the other main saponins ingredients are not referred to. The aim of the present work was to reveal the effect and mechanism of protodioscin (PD), MP and pseudoprotodioscin (PPD) on the synthesis-related gene expression of cholesterol and triglycerides. MTT assay apoptosis assay with annexin AV-APC and 7-AAD double staining were performed. MicroRNA assay and qRT-PCR were used to analyze the gene expression which regulates synthesis of cholesterol and triglycerides. Western blot was to demonstrate the levels of target proteins. Cholesterol efflux assay was executed to study the stimulative effect of saponins on cholesterol efflux. In Hep G2 cells, PPD increased ABCA1 protein and mRNA levels, and promoted the effluxion of ApoA-1-mediated cholesterol. The underlying mechanisms involved that PPD inhibited SREBP1c and SREBP2 transcription by decreasing microRNA 33a/b levels. This procedure reciprocally led to the increase of ABCA1 levels. In THP-1 macrophages, PPD showed the similar effect, which reduced HMGCR, FAS and ACC mRNA levels and promoted low density lipoprotein receptor by decreasing the PCSK9 levels. These studies demonstrated that PPD is a potential agent for cholesterol efflux, SREBPs and microRNA 33a/b inhibition, which related to the gene expression for the synthesis of cholesterol and triglycerides.


Assuntos
Colesterol/biossíntese , Diosgenina/análogos & derivados , MicroRNAs/antagonistas & inibidores , Saponinas/farmacologia , Proteína de Ligação a Elemento Regulador de Esterol 1/antagonistas & inibidores , Proteína de Ligação a Elemento Regulador de Esterol 2/antagonistas & inibidores , Triglicerídeos/biossíntese , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Dioscorea/química , Diosgenina/farmacologia , Células Hep G2 , Humanos , MicroRNAs/genética , Extratos Vegetais/farmacologia , Pró-Proteína Convertase 9/metabolismo , Receptores de LDL/metabolismo , Rizoma/química , Células THP-1
2.
Mol Cell ; 76(5): 811-825.e14, 2019 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-31628041

RESUMO

Physical contact between organelles is vital to the function of eukaryotic cells. Lipid droplets (LDs) are dynamic organelles specialized in lipid storage that interact physically with mitochondria in several cell types. The mechanisms coupling these organelles are, however, poorly understood, and the cell-biological function of their interaction remains largely unknown. Here, we discover in adipocytes that the outer mitochondrial membrane protein MIGA2 links mitochondria to LDs. We identify an amphipathic LD-targeting motif and reveal that MIGA2 binds to the membrane proteins VAP-A or VAP-B in the endoplasmic reticulum (ER). We find that in adipocytes MIGA2 is involved in promoting triglyceride (TAG) synthesis from non-lipid precursors. Our data indicate that MIGA2 links reactions of de novo lipogenesis in mitochondria to TAG production in the ER, thereby facilitating efficient lipid storage in LDs. Based on its presence in many tissues, MIGA2 is likely critical for lipid and energy homeostasis in a wide spectrum of cell types.


Assuntos
Adipócitos/metabolismo , Lipogênese/fisiologia , Proteínas de Membrana/metabolismo , Proteínas Mitocondriais/metabolismo , Células 3T3 , Adipócitos/fisiologia , Animais , Células COS , Diferenciação Celular/fisiologia , Retículo Endoplasmático/metabolismo , Células HEK293 , Humanos , Gotículas Lipídicas/metabolismo , Lipogênese/genética , Proteínas de Membrana/fisiologia , Camundongos , Mitocôndrias/metabolismo , Proteínas Mitocondriais/fisiologia , Triglicerídeos/biossíntese , Proteínas de Transporte Vesicular/metabolismo
3.
Genomics Proteomics Bioinformatics ; 17(3): 260-272, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31494267

RESUMO

Chromochloris zofingiensis represents an industrially relevant and unique green alga, given its capability of synthesizing triacylglycerol (TAG) and astaxanthin simultaneously for storage in lipid droplets (LDs). To further decipher lipid metabolism, the nitrogen deprivation (ND)-induced LDs from C. zofingiensis were isolated, purified, and subjected to proteomic analysis. Intriguingly, many C. zofingiensis LD proteins had no orthologs present in LD proteome of the model alga Chlamydomonas reinhardtii. Seven novel LD proteins (i.e., two functionally unknown proteins, two caleosins, two lipases, and one l-gulonolactone oxidase) and the major LD protein (MLDP), which were all transcriptionally up-regulated by ND, were selected for further investigation. Heterologous expression in yeast demonstrated that all tested LD proteins were localized to LDs and all except the two functionally unknown proteins enabled yeast to produce more TAG. MLDP could restore the phenotype of mldp mutant strain and enhance TAG synthesis in wild-type strain of C. reinhardtii. Although MLDP and caleosins had a comparable abundance in LDs, they responded distinctly to ND at the transcriptional level. The two lipases, instead of functioning as TAG lipases, likely recycled polar lipids to support TAG synthesis. For the first time, we reported that l-gulonolactone oxidase was abundant in LDs and facilitated TAG accumulation. Moreover, we also proposed a novel working model for C. zofingiensis LDs. Taken together, our work unravels the unique characteristics of C. zofingiensis LDs and provides insights into algal LD biogenesis and TAG synthesis, which would facilitate genetic engineering of this alga for TAG improvement.


Assuntos
Proteínas de Algas/metabolismo , Clorófitas/metabolismo , Gotículas Lipídicas/metabolismo , Metabolismo dos Lipídeos , Proteômica/métodos , Ácidos Graxos/metabolismo , Mutação/genética , Nitrogênio/deficiência , Fases de Leitura Aberta/genética , Fenótipo , Proteoma/metabolismo , Saccharomyces cerevisiae/metabolismo , Triglicerídeos/biossíntese
4.
Artigo em Inglês | MEDLINE | ID: mdl-31473330

RESUMO

Estradiol (E2) is a sex steroid hormone that modulates multiple physiological processes in teleosts. The aim of this study was to explore the role of E2 in the hepatic lipid metabolism of hybrid tilapia. The hybrid tilapias were injected with different concentrations of E2 (0 mg/kg, 10 mg/kg, 25 mg/kg and 50 mg/kg) and ICI 182,780 (ICI) (35 mg/kg) (an E2 receptor antagonist). Subsequently, the liver lipid depositions were analyzed by tissue sections with oil red O staining. Serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and nonesterified fatty acids (NEFAs) were assayed from the fish in different groups. Genes related to very low-density lipoprotein (VLDL) assembly, lipoprotein lipase and lipoprotein receptors, fatty acid uptake and triacylglycerol metabolism were determined by quantitative RT-PCR. The results showed that 50 mg/kg E2 injections enlarged the lipid droplets significantly. Simultaneously, the E2 injections tended to upregulate TC, TG, LDL, and HDL in the serum. The 50 mg/kg E2 group showed a significantly higher expression of the VLDL assembly genes but depressed levels of LDLR and LRP1. In addition, FABP3, FABP11a and DGAT2 were significantly elevated, while CD36 and ACO1 decreased in the 50 mg/kg E2 injection. The ICI injection inhibited the expression of MTP, LPL, LRP1, CD36, FABP11a, ACO1 and FAS in tilapia livers. These results demonstrated that by stimulating the expression of genes associated with the VLDL assembly, inhibiting lipoprotein lipase and lipoprotein receptor-related genes and promoting the rate-limiting enzyme in the synthesis of the TG, E2 induced deposition of lipids in the livers of hybrid tilapia. Overall, the results suggest a role for E2 in fish lipid metabolisms that provide new clues to illustrate the sex steroid function in energy metabolism in livers.


Assuntos
Estradiol/farmacologia , Proteínas de Peixes/biossíntese , Regulação da Expressão Gênica/efeitos dos fármacos , Fígado/metabolismo , Tilápia/metabolismo , Triglicerídeos/biossíntese , Animais , Cruzamentos Genéticos , Relação Dose-Resposta a Droga , Feminino , Proteínas de Peixes/genética , Masculino , Tilápia/genética , Triglicerídeos/genética
5.
Gene ; 718: 144073, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31446096

RESUMO

Cell morphology of the oleaginous fungus, Aspergillus oryzae BCC7051, was genetically engineered by disruption of non-essential genes involved in cell wall biosynthesis. Comparative phenotypic analysis of two disruptant strains defective either in α-1,3-glucan synthase 1 (ΔAoAgs1) or chitin synthase B (ΔAoChsB), and the wild type showed that the ΔAoAgs1 strain had no alterations in colonial growth and sporulation when grown on agar medium whereas the ΔAoChsB disruptant showed growth retardation and lower sporulation. However, tiny and loose pellets were found in the ΔAoAgs1 culture grown in liquid medium, where fungal pellet size was decreased by 35-50% of the wild type size. Further investigation of the ΔAoAgs1 mutant grown under stress-induced conditions, including high salt concentration, ionic strength and osmolarity, showed that its growth and development remained similar to that of the wild type. When cultivating the ΔAoAgs1 strain in a stirred-tank bioreactor, lipid production in terms of titer and productivity was significantly improved. As compared to the wild type, an increase of triacylglycerol and ergosterol contents with a proportional decrease in steryl ester content was observed in the ΔAoAgs1 strain. These results suggest that the morphologically engineered strain of A. oryzae is a robust cell chassis useful for exploitation in further production development of functional lipids with industrial significance.


Assuntos
Aspergillus oryzae/metabolismo , Ergosterol/biossíntese , Engenharia Metabólica , Microrganismos Geneticamente Modificados/metabolismo , Triglicerídeos/biossíntese , Aspergillus oryzae/genética , Quitina Sintase/genética , Quitina Sintase/metabolismo , Ergosterol/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Deleção de Genes , Genes Fúngicos , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Microrganismos Geneticamente Modificados/genética , Triglicerídeos/genética
6.
Int J Mol Sci ; 20(15)2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31344914

RESUMO

The deregulation of cancer cell metabolic networks is now recognized as one of the hallmarks of cancer. Abnormal lipid synthesis and extracellular lipid uptake are advantageous modifications fueling the needs of uncontrolled cancer cell proliferation. Fatty acids are placed at the crossroads of anabolic and catabolic pathways, as they are implicated in the synthesis of phospholipids and triacylglycerols, or they can undergo ß-oxidation. Key players to these decisions are the long-chain acyl-CoA synthetases, which are enzymes that catalyze the activation of long-chain fatty acids of 12-22 carbons. Importantly, the long-chain acyl-CoA synthetases are deregulated in many types of tumors, providing a rationale for anti-tumor therapeutic opportunities. The purpose of this review is to summarize the last up-to-date findings regarding their role in cancer, and to discuss the related emerging tumor targeting opportunities.


Assuntos
Coenzima A Ligases/metabolismo , Lipídeos/genética , Neoplasias/genética , Animais , Coenzima A Ligases/genética , Humanos , Lipídeos/biossíntese , Neoplasias/enzimologia , Neoplasias/patologia , Fosfolipídeos/biossíntese , Fosfolipídeos/metabolismo , Triglicerídeos/biossíntese , Triglicerídeos/metabolismo
7.
Bioprocess Biosyst Eng ; 42(10): 1561-1571, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31187270

RESUMO

In this study, the microalga Chlorella saccharophila was subjected to ultraviolet (UV) mutagenesis, and mutant screening was conducted based on acidity tolerance to generate mutants with increased triacylglycerol (TAG) and polyunsaturated fatty acid (PUFA) contents. Two improved mutant strains (M1 and M5) were generated. M1 and M5 accumulated 27.2% and 27.4% more TAG, respectively, and showed stronger fluorescence intensity than the wild-type (WT) strain when the cells of these mutants were stained with the lipophilic Nile Red stain. In the M1 mutant, 50.5% of the fatty acid methyl esters (FAMEs) were saturated (C16:0 and C18:0) and 25.27% were monounsaturated (C18:1) fatty acids which are suitable for biofuels production. In the M5 mutant, 65.19% of the total FAMEs were nutritional PUFAs (C16:2, C18:2, and C18:3), while these FAMEs were not detected in the WT. These results demonstrated that UV mutagenesis coupled to an acid pH screening strategy represents a valuable and fast platform to generate mutants of C. saccharophila with improved TAG and PUFA contents for biofuels and nutraceutical applications, respectively.


Assuntos
Chlorella , Ácidos Graxos Insaturados , Microalgas , Mutação , Triglicerídeos , Chlorella/genética , Chlorella/metabolismo , Ácidos Graxos Insaturados/biossíntese , Ácidos Graxos Insaturados/genética , Microalgas/genética , Microalgas/metabolismo , Triglicerídeos/biossíntese , Triglicerídeos/genética
8.
Bioresour Technol ; 289: 121686, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31238290

RESUMO

Chlorella kessleri accumulates triacylglycerol usable for biodiesel-fuel production to >20% dry cell weight in three days when cultured in three-fold diluted seawater, which imposes the combinatory stress of hyperosmosis and nutrients limitation. The quantitative behavior of major C-compounds, and related-gene expression patterns were investigated in Chlorella cells stressed with hyperosmosis, nutrients limitation, or their combination, to elucidate the C-metabolism for economical seawater-based triacylglycerol accumulation. Combinatory-stress cells showed repressed protein synthesis with initially accumulated starch being degraded later, the C-metabolic flow thereby being diverted to fatty acid and subsequent triacylglycerol accumulation. This C-flow diversion was induced by cooperative actions of nutrients-limitation and hyperosmosis. Semi-quantitative PCR analysis implied positive rewiring of the diverted C-flow into triacylglycerol in combinatory-stress cells through upregulation of gene expression concerning fatty acid and triacylglycerol synthesis, and starch synthesis and degradation. The information of regulatory C-metabolism will help reinforce the seawater-based triacylglycerol accumulation ability in algae including Chlorella.


Assuntos
Carbono/metabolismo , Chlorella/metabolismo , Triglicerídeos/biossíntese , Biocombustíveis , Ácidos Graxos/metabolismo , Água do Mar , Amido/metabolismo
9.
Gene ; 706: 106-114, 2019 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-31039437

RESUMO

Biological significance of 18-carbon polyunsaturated fatty acids, γ-linolenic acid (GLA; C18:3 n-6) and dihomo-γ-linolenic acid (DGLA; C20:3 n-6) has gained much attention in the systematic development of optimized strains for industrial applications. In this work, a n-6 PUFAs-producing strain of Aspergillus oryzae was generated by manipulating metabolic reactions in fatty acid modification and triacylglycerol biosynthesis. The codon-optimized genes coding for Δ6-desaturase and Δ6-elongase of Pythium sp., and diacylglycerol acyltransferase 2 (mMaDGAT2) of Mortierella alpina were co-transformed in a single vector into A. oryzae BCC14614, yielding strain TD6E6-DGAT2. Comparative phenotypic analysis showed that a 70% increase of lipid titer was found in the engineered strain, which was a result of a significant increase in triacylglycerol (TAG) content (52.0 ±â€¯1.8% of total lipids), and corresponded to the increased size of lipid particles observed in the fungal cells. Interestingly, the proportions of GLA and DGLA in neutral lipids of the engineered strain were similar, with the highest titers obtained in the high C:N culture (29:0; 6% glucose) during the lipid-accumulating stage of growth. Time-course expression analysis of the engineered strain revealed transcriptional control of TAG biosynthesis through a co-operation between the native DGAT2 of A. oryzae and the transformed mMaDGAT2.


Assuntos
Aspergillus oryzae/metabolismo , Lipídeos/biossíntese , Engenharia Metabólica/métodos , Ácido 8,11,14-Eicosatrienoico/metabolismo , Ácido Araquidônico/biossíntese , Aspergillus oryzae/genética , Aspergillus oryzae/fisiologia , Vias Biossintéticas , Ácidos Graxos/metabolismo , Ácidos Graxos Insaturados/metabolismo , Proteínas Fúngicas/genética , Mortierella/genética , Triglicerídeos/biossíntese , Ácido gama-Linolênico/biossíntese
10.
Mol Med Rep ; 19(6): 5087-5096, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31059046

RESUMO

The present study aimed to investigate the inhibitory effects and the mechanisms underlying 17ß­estradiol (E2) effects on triglyceride synthesis and insulin resistance in skeletal muscle tissues and cells. Ovariectomy (OVX) was performed on 6­month­old female rats treated with or without E2. Subsequently, various serum biochemical markers were measured. Additionally, pathological alterations of the uterus, liver and skeletal muscle were analyzed, and the content of triglycerides (TG) in muscle was detected. Differentiated myotubes formed by C2C12 cells were treated with palmitic acid (PA) or pretreated with E2, estrogen receptor (ESR) 1 agonist propylpyrazoletriol (PPT) and ESR2 agonist diarylpropionitrile (DPN). Subsequently, the mRNA or protein expression levels of ESR1/2, peroxisome proliferator activated receptor α (PPARα), CD36 molecule (CD36), fatty acid synthase (FASN), perilipin 2 (PLIN2), phosphorylated acetyl­CoA carboxylase α (p­ACACA), p­AKT serine/threonine kinase (p­AKT) and p­mitogen­activated protein kinase 8 (p­MAPK8) were analyzed in skeletal muscle or in C2C12 cells by reverse transcription­semi­quantitative polymerase chain reaction and western blotting. The present results suggested that treatment with E2 inhibited OVX­induced body weight gain, TG accumulation and insulin resistance. The protein or mRNA expression levels of ESR1, CD36, PPARα, p­ACACA and p­AKT were decreased, whereas the protein or mRNA expression levels of ESR2, PLIN2, FASN and p­MAPK8 were increased in the OVX group. Of note, treatment with E2 restored the expression levels of the aforementioned factors. In C2C12 cells, treatment with E2 or PPT reversed the alterations induced by treatment with PA. In contrast, pretreatment with DPN did not influence the effect of PA. Collectively, E2 was able to interact with ESR1, thus activating the CD36­PPARα pathway, decreasing the level of TG in the muscles and improving insulin resistance in skeletal muscles and C2C12 cells.


Assuntos
Estradiol/farmacologia , Receptor alfa de Estrogênio/metabolismo , Triglicerídeos/biossíntese , Animais , Linhagem Celular , Regulação para Baixo/efeitos dos fármacos , Receptor alfa de Estrogênio/agonistas , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Receptor beta de Estrogênio/metabolismo , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Feminino , Resistência à Insulina , Camundongos , Músculo Esquelético/citologia , Músculo Esquelético/metabolismo , Ovariectomia , Ácido Palmítico/farmacologia , Perilipina-2/genética , Perilipina-2/metabolismo , Fenóis/farmacologia , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirazóis/farmacologia , Ratos , Ratos Sprague-Dawley , Regulação para Cima/efeitos dos fármacos
11.
Sheng Li Xue Bao ; 71(2): 279-286, 2019 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-31008487

RESUMO

The aim of this study was to investigate the role of S100 calcium binding protein A16 (S100A16) in lipid metabolism in hepatocytes and its possible biological mechanism. HepG2 cells (human hepatoma cell line) were cultured with fatty acid to establish fatty acid culture model. The control model was cultured without fatty acid. Each model was divided into three groups and transfected with S100a16 over-expression, shRNA and vector plasmids, respectively. The concentration of triglyceride (TG) in the cells was measured by kit, and the lipid droplets was observed by oil red O staining. Immunoprecipitation and mass spectrometry were used to find the interesting proteins interacting with S100A16, and the interaction was verified by immunoprecipitation. The further mechanism was studied by Western blot and qRT-PCR. The results showed that the intracellular lipid droplet and TG concentrations in the fatty acid culture model were significantly higher than those in the control model. The accumulation of intracellular fat in the S100a16 over-expression group was significantly higher than that in the vector plasmid transfection group. There was an interaction between heat shock protein A5 (HSPA5) and S100A16. Over-expression of S100A16 up-regulated protein expression levels of HSPA5, inositol-requiring enzyme 1α (IRE1α) and pIREα1, which belong to endoplasmic reticulum stress HSPA5/IRE1α-XBP1 pathway. Meanwhile, over-expression of S100A16 up-regulated the mRNA expression levels of adipose synthesis-related gene Srebp1c, Acc and Fas. In the S100a16 shRNA plasmid transfection group, the above-mentioned protein and mRNA levels were lower than those of vector plasmid transfection group. These results suggest that S100A16 may promote lipid synthesis in HepG2 cells through endoplasmic reticulum stress HSPA5/IRE1α-XBP1 pathway.


Assuntos
Estresse do Retículo Endoplasmático , Metabolismo dos Lipídeos , Proteínas S100/fisiologia , Endorribonucleases/fisiologia , Proteínas de Choque Térmico/fisiologia , Células Hep G2 , Humanos , Proteínas Serina-Treonina Quinases/fisiologia , Triglicerídeos/biossíntese , Proteína 1 de Ligação a X-Box/fisiologia
12.
PLoS One ; 14(4): e0214144, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31009469

RESUMO

Castration is an important means of improving the beef quality via increasing fat deposition. However, little is known about the molecular mechanism underlying the fat deposition after castration. Here, the intramuscular fat (IMF) content of the steer group was shown to be much higher than the bull group. To understand transcriptional changes in the genes involved in fat deposition following castration, differential expression patterns of mRNAs in liver tissue were investigated in steers and bulls using RNA sequencing. In total, we obtained 58,282,367-54,918,002 uniquely mapped reads, which covered 90.13% of the currently annotated transcripts; 5,864 novel transcripts and optimized 9,088 known genes were determined. These results indicated that castration could change the expression patterns of mRNAs in liver tissue, and 282 differentially expressed genes (DEGs) were detected between steers and bulls. KEGG pathway analysis showed that the DEGs were mostly enriched in PPAR signaling pathway, steroid biosynthesis, steroid hormone biosynthesis, and biosynthesis of fatty acids. Furthermore, eight DEGs were corroborated via quantitative real-time PCR and we found that FABP1 gene knockdown in bovine hepatocytes prominently reduced intracellular triacylglycerol (TAG) synthesis and very low density lipoprotein (VLDL) secretion in culture medium. In summary, these results indicate that FABP1 may promote fat deposition by promoting the production and secretion of TAG and VLDL in steer liver.


Assuntos
Proteínas de Ligação a Ácido Graxo/genética , Ácidos Graxos/genética , Lipogênese/genética , Triglicerídeos/metabolismo , Tecido Adiposo/crescimento & desenvolvimento , Tecido Adiposo/metabolismo , Animais , Bovinos , Ácidos Graxos/biossíntese , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica , Hepatócitos/metabolismo , Fígado/metabolismo , Masculino , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/metabolismo , Orquiectomia , RNA Mensageiro/genética , Carne Vermelha , Triglicerídeos/biossíntese , Triglicerídeos/genética
13.
Metabolism ; 95: 46-56, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30935969

RESUMO

OBJECTIVE: Alcohol overconsumption and abuse lead to alcoholic liver disease (ALD), which is a major chronic liver disease worldwide. Chitinase-3-like protein 1 (CHI3L1) have an important role in the pathogenesis of inflammatory disease. However, the role of CHI3L1 in ALD has not yet been reported. In the present study, we investigated the effect of CHI3L1 on chronic plus binge ethanol-induced liver injury. METHODS: CHI3L1 knock out (KO) mice and their littermate control mice based on C57BL/6 (10-12 weeks old) were fed on a Lieber-DeCarli diet containing 6.6% ethanol for 10 days. And, CHI3L1 siRNA or CHI3L1 expressing vector was transfected HepG2 cells were treated with ethanol or without. RESULTS: Ethanol-induced hepatic triglyceride (TG) levels and the mRNA levels of TG synthesis-related genes such as acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS) and stearoyl-CoA desaturase-1 (SCD1) were decreased in the liver of CHI3L1 knock out (KO) mice and the HepG2 cells transfected with CHI3L1 siRNA. Increased mRNA level and activation of SREBP1 which is transcription factor of ACC, FAS and SCD1 by ethanol feeding were reduced in the liver of ethanol-fed CHI3L1 KO mice. Moreover, ethanol-induced SREBP1 luciferase activity and mRNA level of SREBP1, ACC, FAS and SCD1 were also decreased in the HepG2 cells transfected with CHI3L1 siRNA, while those were further increased in the HepG2 cells treated with recombinant human CHI3L1. Furthermore, oxidative stress and up-regulated pro-inflammatory cytokines by ethanol were recovered in the liver of ethanol-fed CHI3L1 KO mice. CONCLUSION: Our finding suggest that inhibition of CHI3L1 suppressed ethanol-induced liver injury through inhibition of TG synthesis, and the blocking of oxidative stress and hepatic inflammation induced SREBP1 activity could be significant.


Assuntos
Proteína 1 Semelhante à Quitinase-3/deficiência , Hepatopatias Alcoólicas/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Triglicerídeos/biossíntese , Animais , Bebedeira/complicações , Linhagem Celular , Depressores do Sistema Nervoso Central/farmacologia , Proteína 1 Semelhante à Quitinase-3/genética , Citocinas/metabolismo , Etanol/farmacologia , Feminino , Humanos , Inflamação/genética , Inflamação/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Estresse Oxidativo
14.
FEMS Yeast Res ; 19(3)2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30985885

RESUMO

In this study, we found that cell cycle arrest induced by alpha-factor mating pheromone (G1), hydroxyurea (S) or nocodazole (G2/M) was associated to increased lipid droplet (LD) content. To identify novel cell cycle genes involved in LD homeostasis, we screened a deletion library for strains with altered LD levels. Among the mutants related to mitotic cell cycle, we found 24 hits that displayed a significantly higher LD content. Ontology mapping showed that neither a biological process nor a specific cell cycle phase was enriched among the hits. We decided to further study the role of SWI4 on LD homeostasis as it is involved in G1/S transition, a stage where lipolysis is active. The high LD content of swi4Δ mutant was not due to inhibition of lipolysis, but due to an increase in triacylglycerol (TAG) synthesis. In addition, deletion of the AMP kinase gene SNF1 or inhibition of TORC1 activity, both known regulators of LD homeostasis, further increased the LD content of a swi4Δ mutant. These findings highlight a role of the cell cycle regulator SWI4 in the coordination of lipid metabolism which is independent of the TORC1 and SNF1/AMPK pathways.


Assuntos
Pontos de Checagem do Ciclo Celular , Regulação Fúngica da Expressão Gênica , Gotículas Lipídicas/metabolismo , Saccharomyces cerevisiae/metabolismo , Triglicerídeos/biossíntese , Proteínas de Ligação a DNA/genética , Deleção de Genes , Homeostase , Mutação , Regiões Promotoras Genéticas , Proteínas Serina-Treonina Quinases/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição Genética
15.
Microb Cell Fact ; 18(1): 53, 2019 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-30866936

RESUMO

BACKGROUND: Microalgae are promising sources of lipid triacylglycerol (TAG) for sustainable production of natural edible oils and biofuels. Nevertheless, products derived from microalgal TAG are not yet economically feasible; increasing TAG content via targeted genetic engineering of genes in TAG biosynthesis pathway are important to achieve economic viability. To increase TAG content, oleaginous microalga Neochloris oleoabundans was genetically engineered with the endogenous enzyme lysophosphatidic acid acyltransferase (NeoLPAAT1) responsible for plastidial TAG biosynthesis RESULTS: NeoLPAAT1 was found to contain all canonical motifs attributed to LPAAT proteins, two hypothetical membrane-spanning domains and a putative chloroplast transit peptide, indicating as a member of plastidial LPAAT type 1 subfamily. The NeoLPAAT1-expression cassette integrated in N. oleoabundans transformant was confirmed by PCR. The neutral lipid content in the transformant detected by Nile red staining was 1.6-fold higher than in wild type. The NeoLPAAT1 transcript was twofold higher in the transformant than wild type. Considerably higher lipid quantity was found in the transformant than wild type: total lipid content increased 1.8- to 1.9-fold up to 78.99 ± 1.75% dry cell weight (DCW) and total lipid productivity increased 1.8- to 2.4-fold up to 16.06 ± 2.68 mg/L/day; while TAG content increased 2.1- to 2.2-fold up to 55.40 ± 5.56% DCW and TAG productivity increased 1.9- to 2.8-fold up to 10.67 ± 2.37 mg/L/day. A slightly altered fatty acid composition was detected in the transformant compared to wild type; polyunsaturated fatty acid (C18:2) increased to 19% from 11%. NeoLPAAT1-overexpression stability was observed in the transformant continuously maintained in solid medium over 150 generations in a period of about 6 years. CONCLUSIONS: Our results demonstrate the considerably increased TAG content and productivity in N. oleoabundans by overexpression of plastidial NeoLPAAT1 that are important for products derived from microalgal TAG to achieve economic viability. Plastidial LPAAT1 can be a candidate for target genetic manipulation to increase TAG content in other microalgal species with desired characteristics for production of natural edible oils and biofuels.


Assuntos
Aciltransferases/genética , Microalgas/genética , Microalgas/metabolismo , Organismos Geneticamente Modificados/genética , Triglicerídeos , Biocombustíveis , Plastídeos/genética , Triglicerídeos/biossíntese , Triglicerídeos/genética , Triglicerídeos/metabolismo
16.
Nutrients ; 11(3)2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-30823376

RESUMO

Under normoxic conditions, adipocytes in primary culture convert huge amounts of glucose to lactate and glycerol. This "wasting" of glucose may help to diminish hyperglycemia. Given the importance of insulin in the metabolism, we have studied how it affects adipocyte response to varying glucose levels, and whether the high basal conversion of glucose to 3-carbon fragments is affected by insulin. Rat fat cells were incubated for 24 h in the presence or absence of 175 nM insulin and 3.5, 7, or 14 mM glucose; half of the wells contained 14C-glucose. We analyzed glucose label fate, medium metabolites, and the expression of key genes controlling glucose and lipid metabolism. Insulin increased both glucose uptake and the flow of carbon through glycolysis and lipogenesis. Lactate excretion was related to medium glucose levels, which agrees with the purported role of disposing excess (circulating) glucose. When medium glucose was low, most basal glycerol came from lipolysis, but when glucose was high, release of glycerol via breakup of glycerol-3P was predominant. Although insulin promotes lipogenesis, it also limited the synthesis of glycerol-3P from glucose and its incorporation into acyl-glycerols. We assume that this is a mechanism of adipose tissue defense to avoid crippling fat accumulation which has not yet been described.


Assuntos
Glicerol/metabolismo , Insulina/farmacologia , Lipogênese/fisiologia , Triglicerídeos/biossíntese , Animais , Masculino , Ratos , Ratos Wistar
17.
Appl Microbiol Biotechnol ; 103(9): 3727-3736, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30915502

RESUMO

Shea tree (Vitellaria paradoxa) is one economically important plant species that mainly distributes in West Africa. Shea butter extracted from shea fruit kernels can be used as valuable products in the food and cosmetic industries. The most valuable composition in shea butter was one kind of triacylglycerol (TAG), 1,3-distearoyl-2-oleoyl-glycerol (SOS, C18:0-C18:1-C18:0). However, shea butter production is limited and little is known about the genetic information of shea tree. In this study, we tried to reveal genetic information of shea tree and identified shea TAG biosynthetic genes for future shea butter production in yeast cell factories. First, we measured lipid content, lipid composition, and TAG composition of seven shea fruits at different ripe stages. Then, we performed transcriptome analysis on two shea fruits containing obviously different levels of SOS and revealed a list of TAG biosynthetic genes potentially involved in TAG biosynthesis. In total, 4 glycerol-3-phosphate acyltransferase (GPAT) genes, 8 lysophospholipid acyltransferase (LPAT) genes, and 11 diacylglycerol acyltransferase (DGAT) genes in TAG biosynthetic pathway were predicted from the assembled transcriptome and 14 of them were cloned from shea fruit cDNA. Furthermore, the heterologous expression of these 14 potential GPAT, LPAT, and DGAT genes in Saccharomyces cerevisiae changed yeast fatty acid and lipid profiles, suggesting that they functioned in S. cerevisiae. Moreover, two shea DGAT genes, VpDGAT1 and VpDGAT7, were identified as functional DGATs in shea tree, showing they might be useful for shea butter (SOS) production in yeast cell factories.


Assuntos
Proteínas de Plantas/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Sapotaceae/genética , Triglicerídeos/biossíntese , Leveduras/genética , Leveduras/metabolismo , Vias Biossintéticas , Diacilglicerol O-Aciltransferase/genética , Diacilglicerol O-Aciltransferase/metabolismo , Frutas/genética , Frutas/metabolismo , Engenharia Metabólica , Sapotaceae/enzimologia , Sapotaceae/metabolismo , Transcriptoma
18.
Rev. bras. cir. plást ; 34(1): 31-37, jan.-mar. 2019. ilus, tab
Artigo em Português | LILACS | ID: biblio-994539

RESUMO

Introdução: Lipoaspiração associada a dermolipectomias é o procedimento cirúrgico mais comumente realizado em cirurgia plástica. Apesar de ser considerada uma cirurgia extremamente segura, algumas considerações devem ser levantadas a respeito dos possíveis efeitos metabólicos que essas cirurgias possam causar. O desenvolvimento da técnica tumescente de lipoaspiração permitiu a remoção de grande quantidade de gordura de modo mais seguro. O objetivo é comparar as variações do perfil lipídico em pós-operatório precoce e tardio de pacientes submetidos à lipoaspiração e dermolipectomias. Métodos: Entre outubro de 2006 e junho de 2012, 40 pacientes do sexo feminino candidatas a cirurgias que envolviam lipoaspiração e dermolipectomias foram acompanhadas prospectivamente e o perfil lipídico foi analisado por meio de exames no pré-operatório e no pós-operatório. As cirurgias realizadas foram: mamoplastia + lipoaspiração, abdominoplastia + lipoaspiração e lipoabdominoplastia + mamoplastia. Resultados: Das 40 pacientes que foram acompanhadas no estudo, 20 pacientes do sexo feminino foram selecionadas (após a aplicação dos critérios de exclusão). Em consonância com nosso estudo, Cazes, em 1996, demonstrou que após 12 meses de pós-operatório de lipoabdominoplastia não houve alteração do perfil lipídico das pacientes. Conclusão: Após análise pré- e pós-operatória de 20 pacientes, observamos que não há alterações estatísticas significantes em relação ao perfil lipídico com tendência de equilíbrio das aferições em um ano em patamares próximos aos observados no pré-operatório.


Introduction: Liposuction associated with dermolipectomies is the most commonly performed surgical procedure in plastic surgery. Although regarded as an extremely safe surgery, some considerations must be taken on the possible metabolic effects of these surgeries. The development of the tumescent technique in liposuction allowed the safer removal of large amounts of fat. The objective is to compare lipid profile variations in the early and late postoperative period in patients undergoing liposuction and dermolipectomies. Methods: Between October 2006 and June 2012, 40 female patients who were candidates for surgeries involving liposuction and dermolipectomies were prospectively followed, and the lipid profile was analyzed through preoperative and postoperative examinations. The surgeries performed were mammoplasty + liposuction, abdominoplasty + liposuction, and lipoabdominoplasty + mammoplasty. Results: Of the 40 female patients who were followed, 20 were selected (after applying the exclusion criteria). In agreement with our study, in 1996, Cazes showed that there were no changes in the lipid profile of patients 12 months after lipoabdominoplasty. Conclusion: After a preoperative and postoperative analysis of 20 patients, it was observed that there were no statistically significant changes in the lipid profile and that the measurements after 1 year were close to those obtained in the preoperative period.


Assuntos
Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Complicações Pós-Operatórias/cirurgia , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Procedimentos Cirúrgicos Operatórios/métodos , Triglicerídeos/análise , Triglicerídeos/biossíntese , Lipectomia/métodos , Estudos de Casos e Controles , Transtornos do Metabolismo dos Lipídeos/complicações , Transtornos do Metabolismo dos Lipídeos/diagnóstico , Abdominoplastia/efeitos adversos , Abdominoplastia/métodos , Metabolismo
19.
Aquat Toxicol ; 209: 49-55, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30711855

RESUMO

Organophosphorus compounds exhibit a wide range of toxicity to mammals. In this study the effect of malathion on the growth and biochemical parameters of microalgae was evaluated. Three microalgae (Micractinium pusillum UUIND2, Chlorella singulari UUIND5 and Chlorella sorokiniana UUIND6) were used in this study. Among the three algal strains tested, Chlorella sorokiniana UUIND6 was able to tolerate 100 ppm of malathion. The photosynthetic pigments, the protein, carbohydrate and lipid contents of microalgal cells were also analyzed. About 90% degradation was recorded in 25 ppm, 50 ppm and 70% was recorded in 100 ppm of malathion by Chlorella sorokiniana. A mechanism of degradation of malathion by Chlorella sorokiniana is proposed in this study. Activity of carboxylesterase was increased in algal cells cultivated in malathion containing medium which confirmed that malathion degraded into phosphate. Increased amount of Malondialdehye (MDA) indicate the development of free radicals under the stress of malathion which substantialy increase de novo TAG biosynthesis, while increased level of superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) suggested their association in scavenging of free radical.


Assuntos
Carboxilesterase/metabolismo , Microalgas/metabolismo , Compostos Organofosforados/toxicidade , Praguicidas/toxicidade , Triglicerídeos/biossíntese , Biocombustíveis , Biomassa , Tamanho Celular , Chlorella/citologia , Chlorella/efeitos dos fármacos , Chlorella/metabolismo , Inativação Metabólica/efeitos dos fármacos , Malation/toxicidade , Microalgas/citologia , Microalgas/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier , Testes de Toxicidade , Poluentes Químicos da Água/toxicidade
20.
DNA Cell Biol ; 38(4): 352-357, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30707627

RESUMO

MicroRNAs (miRNAs) can regulate a variety of biological functions such as fat and cholesterol synthesis, translocation, and utilization by regulating degradation or by inhibiting target mRNA translation. In this study, the target gene of miR-21-3p was analyzed through bioinformatics, which predicted Elovl5. Furthermore, miR-21-3p was verified for regulation of triglyceride expression. The results showed that luciferase activity was significantly lower in cells cotransfected with miR-21-3p and Elovl5 reporter vector, pmiR-RB-REPORT-Elovl5-WT, than in cells with miR-21-3p and reporter control vectors, pmiR-RB-REPORT-Elovl5-mut and pmiR-RB-REPORT-Elovl5-si, indicating that target sites exist in the 3'UTR of Elovl5. Further analysis using qPCR and Western blotting showed that the expression of miR-21-3p negatively correlated with the levels of Elovl5 mRNA and protein, suggesting that miR-21-3p might play an important role in regulating Elovl5 gene expression. Finally, transfection with bta-miR-21-3p mimics, bta-miR-21-3p inhibitor, or miRNA-ShNC in mammary epithelial cells suggested that bta-miR-21-3p promotes triglyceride production, which might be attributed to the expression of the target gene Elovl5.


Assuntos
Acetiltransferases/genética , Células Epiteliais/metabolismo , Glândulas Mamárias Animais/citologia , MicroRNAs/genética , Triglicerídeos/biossíntese , Regiões 3' não Traduzidas/genética , Animais , Bovinos , Regulação para Baixo/genética , Feminino
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA