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1.
J Cancer Res Ther ; 16(6): 1382-1386, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33342801

RESUMO

Introduction: Fatty acids (FAs) are the vital constituents of membrane structures. De novo synthesis of FAs includes an enzymatic complex of FA synthase and delta desaturases. These enzymes are overexpressed in tumors, and inhibition of these enzymes is gaining interest. Our aim was to determine if delta desaturase activities are altered in breast cancer (BC) cases and if altered whether delta desaturase activities differ among BC genotypes. Materials and Methods: In this observational comparative study, 50 women with BC and 30 control women were recruited for the study. Gas chromatography-flame ionization detector was used to measure the plasma FA levels. Desaturase activities were assessed as product-to-precursor FA ratios. The Wilcoxon signed-rank test was used to compare between two groups, and P ≤ 0.05 was considered as statistically significant. Results: The FA analysis revealed higher levels of monounsaturated FAs (MUFAs) and linolenic acid metabolites (C18:3n-6, C20:4n-6) in BC patients, whereas C20:5n-3 was higher in controls. The Delta 9 desaturase (D9D) and D6D were higher in BC cases suggesting greater conversion saturated FA to MUFA and linoleic acid to its metabolites. D9D-16 activity was statistically significant (P = 0.03) in BC women, particularly in estrogen-receptor-positive patients. Conclusion: There is limited evidence to substantiate the link between diet and cancer. The current study showed there is an altered lipid desaturase activity. Nutritional intervention and drugs that target the FA pathway may provide a new approach to prevent and treat BC.


Assuntos
Neoplasias da Mama/sangue , Ácidos Graxos Monoinsaturados/sangue , Ácido Linoleico/sangue , Linoleoil-CoA Desaturase/metabolismo , Estearoil-CoA Dessaturase/metabolismo , Adulto , Mama/enzimologia , Mama/patologia , Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Estudos de Casos e Controles , Ácidos Graxos Monoinsaturados/metabolismo , Feminino , Humanos , Ácido Linoleico/metabolismo , Masculino , Pessoa de Meia-Idade , Receptores de Estrogênio/análise , Receptores de Estrogênio/metabolismo
2.
PLoS One ; 15(7): e0236601, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730353

RESUMO

Omega-3 polyunsaturated fatty acids (n-3 PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), exhibit antibacterial and anti-inflammatory activities. Furthermore, diets rich in n-3 PUFAs are known to improve disease resistance and limit pathogen infection in commercial aquaculture fishes. In this study, we examined the effects of transgenic overexpression of n-3 PUFA biosynthesis genes on the physiological response to bacterial infection in tilapia. We first established tilapia strains with single or dual expression of salmon delta-5 desaturase and/or delta-6 desaturase and then challenged the fish with Vibrio vulnificus infection. Interestingly, our data suggest that n-3 PUFA-mediated alterations in gut microbiota may be important in determining disease outcome via effects on immune response of the host. Both liver- and muscle-specific single and dual expression of delta-5 desaturase and delta-6 desaturase resulted in higher n-3 PUFA content in transgenic fish fed with a LO basal diet. The enrichment of n-3 PUFAs in dual-transgenic fish is likely responsible for their improved survival rate and comparatively reduced expression of inflammation- and immune-associated genes after V. vulnificus infection. Gut microbiome analysis further revealed that dual-transgenic tilapia had high gut microbiota diversity, with low levels of inflammation-associated microbiota (i.e., Prevotellaceae). Thus, our findings indicate that dual expression of transgenic delta-5 and delta-6 desaturase in tilapia enhances disease resistance, an effect that is associated with increased levels of n-3 PUFAs and altered gut microbiota composition.


Assuntos
Resistência à Doença , Ácidos Graxos Dessaturases/metabolismo , Proteínas de Peixes/metabolismo , Microbioma Gastrointestinal , Linoleoil-CoA Desaturase/metabolismo , Tilápia/microbiologia , Vibrio vulnificus/patogenicidade , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/microbiologia , Dieta/veterinária , Análise Discriminante , Resistência à Doença/genética , Ácidos Docosa-Hexaenoicos/metabolismo , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Ômega-3/metabolismo , Doenças dos Peixes/microbiologia , Doenças dos Peixes/patologia , Proteínas de Peixes/genética , Expressão Gênica , Análise dos Mínimos Quadrados , Linoleoil-CoA Desaturase/genética , Tilápia/genética , Vibrioses/patologia , Vibrioses/veterinária
3.
Biochemistry ; 59(14): 1398-1409, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32208646

RESUMO

Marine algae are a major source of ω-3 long-chain polyunsaturated fatty acids (ω3-LCPUFAs), which are conditionally essential nutrients in humans and a target for industrial production. The biosynthesis of these molecules in marine algae requires the desaturation of fatty acids by Δ6-desaturases, and enzymes from different species display a range of specificities toward ω3- and ω6-LCPUFA precursors. In the absence of a molecular structure, the structural basis for the variable substrate specificity of Δ6-desaturases is poorly understood. Here we have conducted a consensus mutagenesis and ancestral protein reconstruction-based analysis of the Δ6-desaturase family, focusing on the ω3-specific Δ6-desaturase from Micromonas pusilla (MpΔ6des) and the bispecific (ω3/ω6) Δ6-desaturase from Ostreococcus tauri (OtΔ6des). Our characterization of consensus amino acid substitutions in MpΔ6des revealed that residues in diverse regions of the protein, such as the N-terminal cytochrome b5 domain, can make important contributions to determining substrate specificity. Ancestral protein reconstruction also suggests that some extant Δ6-desaturases, such as OtΔ6des, could have adapted to different environmental conditions by losing specificity for ω3-LCPUFAs. This data set provides a map of regions within Δ6-desaturases that contribute to substrate specificity and could facilitate future attempts to engineer these proteins for use in biotechnology.


Assuntos
Clorófitas/enzimologia , Linoleoil-CoA Desaturase/química , Linoleoil-CoA Desaturase/genética , Clorófitas/química , Clorófitas/classificação , Clorófitas/genética , Ácidos Graxos Ômega-3/química , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Ômega-6/química , Ácidos Graxos Ômega-6/metabolismo , Linoleoil-CoA Desaturase/metabolismo , Família Multigênica , Mutagênese , Filogenia , Conformação Proteica , Especificidade por Substrato
4.
J Biotechnol ; 308: 130-140, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31843519

RESUMO

Buglossoides arvensis seed oil is the richest natural source of stearidonic acid (SDA), an ω-3 fatty acid with nutraceutical potential superior to α-linolenic acid (ALA). The molecular basis of polyunsaturated fatty acid synthesis in B. arvensis is unknown. Here, we describe the identification of B. arvensis fatty acid desaturase2 (BaFAD2), fatty acid desaturase3 (BaFAD3), and Delta-6-desaturase (BaD6D-1 and BaD6D-2) genes by mining the transcriptome of developing seeds and their functional characterization by heterologous expression in Saccharomyces cerevisiae. In silico analysis of their encoded protein sequences showed conserved histidine-boxes and signature motifs essential for desaturase activity. Expression profiling of these genes showed higher transcript abundance in reproductive tissues than in vegetative tissues, and their expression varied with temperature stress treatments. Yeast expressing BaFAD2 was found to desaturate both oleic acid and palmitoleic acid into linoleic acid (LA) and hexadecadienoic acid, respectively. Fatty acid supplementation studies in yeast expressing BaFAD3 and BaD6D-1 genes revealed that the encoded enzyme activities of BaFAD3 efficiently converted LA to ALA, and BaD6D-1 converted LA to γ-linolenic acid and ALA to SDA, but with an apparent preference to LA. BaD6D-2 did not show the encoded enzyme activity and is not a functional D6D. Our results provide an insight into SDA biosynthesis in B. arvensis and expand the repository of fatty acid desaturase targets available for biotechnological production of SDA in traditional oilseed crops.


Assuntos
Vias Biossintéticas , Boraginaceae/genética , Ácidos Graxos Insaturados/metabolismo , Perfilação da Expressão Gênica/métodos , Boraginaceae/metabolismo , Simulação por Computador , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Linoleoil-CoA Desaturase/genética , Linoleoil-CoA Desaturase/metabolismo , Microssomos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/genética , Sementes/metabolismo , Estresse Fisiológico , Temperatura
5.
PLoS Biol ; 17(8): e3000364, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31430281

RESUMO

Many eukaryotic microbes have complex life cycles that include both sexual and asexual phases with strict species specificity. Whereas the asexual cycle of the protistan parasite Toxoplasma gondii can occur in any warm-blooded mammal, the sexual cycle is restricted to the feline intestine. The molecular determinants that identify cats as the definitive host for T. gondii are unknown. Here, we defined the mechanism of species specificity for T. gondii sexual development and break the species barrier to allow the sexual cycle to occur in mice. We determined that T. gondii sexual development occurs when cultured feline intestinal epithelial cells are supplemented with linoleic acid. Felines are the only mammals that lack delta-6-desaturase activity in their intestines, which is required for linoleic acid metabolism, resulting in systemic excess of linoleic acid. We found that inhibition of murine delta-6-desaturase and supplementation of their diet with linoleic acid allowed T. gondii sexual development in mice. This mechanism of species specificity is the first defined for a parasite sexual cycle. This work highlights how host diet and metabolism shape coevolution with microbes. The key to unlocking the species boundaries for other eukaryotic microbes may also rely on the lipid composition of their environments as we see increasing evidence for the importance of host lipid metabolism during parasitic lifecycles. Pregnant women are advised against handling cat litter, as maternal infection with T. gondii can be transmitted to the fetus with potentially lethal outcomes. Knowing the molecular components that create a conducive environment for T. gondii sexual reproduction will allow for development of therapeutics that prevent shedding of T. gondii parasites. Finally, given the current reliance on companion animals to study T. gondii sexual development, this work will allow the T. gondii field to use of alternative models in future studies.


Assuntos
Linoleoil-CoA Desaturase/metabolismo , Toxoplasma/enzimologia , Animais , Gatos , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Intestinos/parasitologia , Estágios do Ciclo de Vida/fisiologia , Ácido Linoleico/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Parasitos/metabolismo , Desenvolvimento Sexual/fisiologia , Especificidade da Espécie , Toxoplasma/crescimento & desenvolvimento , Toxoplasma/patogenicidade
6.
Asian Pac J Cancer Prev ; 20(4): 1005-1018, 2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31030467

RESUMO

Background: The phosphatidylinositol 3-kinase/ protein kinase B /mammalian target of rapamycin (PI3K/Akt/ mTOR) signaling regulates multiple cellular processes and organizes cell proliferation, survival, and differentiation with the available nutrients, in particular, fatty acids. Polyunsaturated fatty acids (PUFAs) are cytotoxic to cancer cells and play a critical role in the treatment of multiple sclerosis (MS) and diabetes mellitus (DM). PUFAs are produced in the body by desaturases and elongases from dietary essential fatty acids (EFAs), primarily involving delta-6-desaturase (D6D). D6D is a rate-limiting enzyme for maintaining many aspects of lipid homeostasis and normal health. D6D is important to recognize the mechanisms that regulate the expression of this enzyme in humans. A lower level of D6D was seen in breast tumors compared to normal tissues. Interestingly, the elevated serum level of D6D was seen in MS and DM, which explains the critical role of D6D in inflammatory diseases. Methods: We searched databases of PubMed, Web of Science (WOS), Google Scholar, Scopus and related studies by predefined eligibility criteria. We assessed their quality and extracted data. Results: Regarding the mTOR signaling pathway, there is remarkable contributions of many inflammatory diseases to attention to common metabolic pathways are depicted. Of course, we need to have the insights into each disorder and their pathological process. The first step in balancing the intake of EFAs is to prevent the disruption of metabolism and expression of the D6D enzyme. Conclusions: The ω6 and ω3 pathways are two major pathways in the biosynthesis of PUFAs. In both of these, D6D is a vital bifunctional enzyme desaturating linoleic acid or alpha-linolenic acid. Therefore, if ω6 and ω3 EFAs are given together in a ratio of 2: 1, the D6D expression will be down-regulated and normalized.


Assuntos
Diabetes Mellitus/patologia , Linoleoil-CoA Desaturase/metabolismo , Esclerose Múltipla/patologia , Neoplasias/patologia , Diabetes Mellitus/enzimologia , Humanos , Esclerose Múltipla/enzimologia , Neoplasias/enzimologia , Prognóstico
7.
Animal ; 13(9): 1934-1942, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30774049

RESUMO

Standard feeds are imbalanced in term of n-6/n-3 polyunsaturated fatty acids (PUFA) ratio, with a low proportion of the latter. The reproductive system appears to be strongly affected by administration of n-3 PUFA, and ingredients rich in α-linolenic acid (ALA; i.e. vegetable sources) or EPA and DHA acids (i.e. fish oil) can be included in animal diets to balance PUFA intake. The aim of this study was to evaluate the effect of dietary supplementation with flaxseed (ALA) or fish oil (EPA and DHA) on PUFA metabolism in rabbit does. A total of 60 New Zealand White female rabbits were assigned to three experimental groups: control group, FLAX group fed 10% extruded flaxseed and FISH group fed 3% fish oil. Blood, milk, liver and ovaries were collected from the does to assess the lipid composition; furthermore, FADS2 gene expression was assessed in liver and ovary tissues. Reproductive performance of does was also recorded. The fertility rate and number of weaned rabbits improved with n-3 dietary supplementation: does at first parity showed the lowest reproductive results, but the administration of n-3 reduced the gap between primiparous and multiparous does. Feed consumption and milk production were not affected by the feeding regime. The fatty acid composition of milk, plasma, liver and ovaries were widely influenced by diet, showing higher concentrations of n-3 long-chain PUFA (LCP) in does fed with n-3 enriched diets. FISH diet resulted in the highest n-3 LCP enrichment, whereas in the FLAX group, this increase was lower. Blood and milk showed low levels of LCP, whereas liver and ovaries were the main sites of n-3 LCP synthesis and accumulation. Accordingly, although the liver is the main metabolic centre for LCP synthesis, ovaries also have a prominent role in LCP generation. FADS2 expression in liver and ovary tissue was downregulated by FISH administration. In conclusion, the enrichment of diets with n-3 PUFA could be an effective strategy for improving the reproductive performance of does.


Assuntos
Ração Animal/análise , Suplementos Nutricionais , Ácidos Graxos Insaturados/metabolismo , Óleos de Peixe/administração & dosagem , Linho , Coelhos/fisiologia , Animais , Dieta/veterinária , Ácidos Graxos/metabolismo , Ácidos Graxos Ômega-3/metabolismo , Feminino , Linoleoil-CoA Desaturase/genética , Linoleoil-CoA Desaturase/metabolismo , Fígado/metabolismo , Leite/química , Ovário/metabolismo , Coelhos/sangue , Ácido alfa-Linoleico/metabolismo
8.
Artigo em Inglês | MEDLINE | ID: mdl-30118764

RESUMO

Silver barb (Puntius gonionotus) is considered as a promising medium-sized carp species for freshwater aquaculture in Asia. This study in silver barb was carried out to evaluate the effects of increasing dietary levels of lipid on growth, nutrient utilization, whole-body composition, tissue fatty acid composition and Δ6 fatty acyl desaturase (Δ6 fad) gene expression. Fish (11.3 ±â€¯0.23 g of initial body weight) was fed for 60 days with five experimental diets: FO-0 (control feed); FO-30; FO-60; FO-90 and FO-120 containing 0, 30, 60, 90 and 120 g fish oil kg-1 diet, respectively. Among the diets, the highest specific growth rate (SGR), protein efficiency ratio (PER) and whole-body lipid content, and the lowest feed conversion ratio (FCR) were recorded with FO-120 diet. The saturated fatty acids (SFA) level in the muscle was significantly (P < .05) increased with the enhanced FO supplementation, whereas monounsaturated fatty acids (MUFA) level decreased. Increased level of fish oil in the diet also enhanced the n-3 PUFA and n-3 LC-PUFA (long-chain polyunsaturated fatty acid) in the muscle and liver. The expression of Δ6 fad gene was downregulated, whereas the serum biochemical constituents were either remain unchanged or enhanced with increased FO supplementation in the diets of silver barb.


Assuntos
Ração Animal , Carpas/fisiologia , Ácidos Graxos/metabolismo , Óleos de Peixe/administração & dosagem , Proteínas de Peixes/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Linoleoil-CoA Desaturase/metabolismo , Animais , Aquicultura , Carpas/crescimento & desenvolvimento , Ingestão de Energia , Ácidos Graxos Ômega-3/metabolismo , Óleos de Peixe/metabolismo , Proteínas de Peixes/genética , Humanos , Índia , Linoleoil-CoA Desaturase/genética , Metabolismo dos Lipídeos , Fígado/enzimologia , Fígado/crescimento & desenvolvimento , Fígado/metabolismo , Músculo Esquelético/enzimologia , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/metabolismo , Valor Nutritivo , Especificidade de Órgãos , Distribuição Aleatória , Alimentos Marinhos/análise , Ganho de Peso
9.
Artigo em Inglês | MEDLINE | ID: mdl-30103919

RESUMO

Dietary fatty acids are associated with the development of many chronic diseases, such as obesity, diabetes, cardiovascular disease, metabolic syndrome, and several cancers. This review explores the literature surrounding the combined and individual roles of n-6 PUFAs linoleic acid (LA) and arachidonic acid (AA) as they relate to immune and inflammatory response, cardiovascular health, liver health, and cancer. The evidence suggests that a pro-inflammatory view of LA and AA may be over simplified. Overall, this review highlights gaps in our understanding of the biological roles of LA, AA and their complex relationship with n-3 PUFA and the need for future studies that examine the roles of individual fatty acids, rather than groups.


Assuntos
Ácido Araquidônico/efeitos adversos , Ácido Araquidônico/metabolismo , Ácido Linoleico/efeitos adversos , Ácido Linoleico/metabolismo , Animais , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/metabolismo , Gorduras Insaturadas na Dieta/efeitos adversos , Gorduras Insaturadas na Dieta/metabolismo , Técnicas de Inativação de Genes , Humanos , Inflamação/induzido quimicamente , Inflamação/genética , Inflamação/metabolismo , Linoleoil-CoA Desaturase/genética , Linoleoil-CoA Desaturase/metabolismo , Hepatopatias/etiologia , Hepatopatias/genética , Hepatopatias/metabolismo , Neoplasias/induzido quimicamente , Neoplasias/genética , Neoplasias/metabolismo
10.
Artigo em Inglês | MEDLINE | ID: mdl-30103922

RESUMO

BACKGROUND: Diabetes and pregnancy are both associated with oxidative stress, characterized by an increase of F2-isoprostanes from the non-enzymatic oxidation of arachidonic acid, a n - 6 polyunsaturated fatty acid (PUFA). We hypothesized that pregnant women with pre-existing diabetes will be characterized by elevated levels of specific F2-isoPs isomers and altered PUFA composition in plasma early pregnancy when compared to normoglycemic controls. METHODS: Plasma samples from 23 women with uncomplicated pregnancies and 11 women with pre-existing diabetes in pregnancy were collected between 12 and 18 weeks of pregnancy (MIROS cohort). Six F2-isoprostanes isomers were measured by high-performance liquid chromatography coupled to tandem mass spectrometry. Fatty acids concentrations in plasmatic phospholipids were measured by gas chromatography coupled to a flame ionization detector. RESULTS: F2-isoprostanes, specifically the 8-iso-15(R)-PGF2α levels, were 67% higher in diabetic than normoglycemic pregnancies (p = 0.026). The total n - 6 PUFA and arachidonic acid level did not differ between study groups. In contrast, total n - 3 level was 32% lower in diabetic pregnancies than in controls (p = 0.002); EPA(20:5) and DHA(22:6) being specifically reduced (p = 0.035 and p = 0.003 respectively). Delta-6-desaturase (D6D) activity index, calculated using fatty acid ratios, was 9% lower in pre-existing diabetes than in controls (p = 0.042). CONCLUSIONS: Pre-existing diabetes in early pregnancy displays a distinctive F2-isoprostanes profile when compared to other pathologies of pregnancy, such as preeclampsia, as previously assessed in the same cohort.


Assuntos
Diabetes Mellitus/sangue , F2-Isoprostanos/análise , Ácidos Graxos/análise , Primeiro Trimestre da Gravidez/sangue , Segundo Trimestre da Gravidez/sangue , Adulto , Cromatografia Líquida de Alta Pressão/métodos , F2-Isoprostanos/sangue , Ácidos Graxos/sangue , Feminino , Idade Gestacional , Humanos , Linoleoil-CoA Desaturase/metabolismo , Estresse Oxidativo , Fosfolipídeos/química , Gravidez , Espectrometria de Massas em Tandem/métodos
11.
Artigo em Inglês | MEDLINE | ID: mdl-30030191

RESUMO

Desaturase enzymes play an important role in the synthesis of unsaturated fatty acids. In this study, a complete cDNA sequence of a Δ6 desaturase-like gene was cloned from the hepatopancreas of the red claw crayfish, Cherax quadricarinatus. The full-length 1885 bp sequence comprises a 5' UTR of 254 bp, 3' UTR of 234 bp, and an open reading frame (ORF) of 1377 bp encoding a 458 amino acid polypeptide (GenBank accession no. MF497442). Bioinformatics analysis revealed three conserved histidine-rich regions, a cytochrome b5 domain at the N-terminus, and a haem binding site (HPGG) in the cytochrome b5 domain, all of which are typical of Δ6 desaturases. Quantitative real-time PCR demonstrated significantly higher expression in the hepatopancreas than other tissues. After feeding crayfish four formulated diets in which fish oil was replaced by 0, 33, 67, or 100% highly unsaturated soybean oil for 8 weeks, Δ6 desaturase-like mRNA expression and enzyme activity were higher than in the fish oil only group. Additionally, a 4-week low temperature treatment at 25, 20, 15, or 9 °C increased Δ6 desaturase mRNA expression and enzyme activity with decreasing water temperature. These results may help us better understand the biosynthesis of unsaturated fatty acids in C. quadricarinatus.


Assuntos
Astacoidea/genética , Astacoidea/metabolismo , Regulação da Expressão Gênica , Linoleoil-CoA Desaturase/genética , Linoleoil-CoA Desaturase/metabolismo , Temperatura , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Ácidos Graxos Insaturados/biossíntese , Linoleoil-CoA Desaturase/química , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sequência
12.
Artigo em Inglês | MEDLINE | ID: mdl-29735017

RESUMO

Flavonoids upregulate gene expression of PPAR-α and underregulate the gene expression of SREBP-1c, and their intake increases the plasmatic concentration of n-3 LC-PUFAs. However, the biological mechanisms underlying these effects have not been elucidated. In this work, the effect of oral supplementation of ALA from chia (Salvia hispanica L.) seed oil and anthocyanins from a purple corn extract (PCE) on gene expression of SREBP-1c, PPAR-α and Δ5 and Δ6 desaturases (Δ5D and Δ6D), the activity of these enzymes in the liver as well as the hepatic lipid profile were evaluated in thirty-six female Sprague Dawley rats whose diet was supplemented with olive oil (OL), chia oil (CH), olive oil and PCE (OL + PCE) or chia oil and PCE (CH + PCE). Gene expression of PPAR-α was significantly higher when supplemented with CH and CH + PCE, SREBP-1c gene expression was higher when supplemented with chia oil. CH supplementation enhanced Δ5D expression whereas no significant differences between treatments were observed concerning Δ6D gene expression. Activities of both desaturases were increased by including olive oil (OL + PCE and OL), and they were found to be higher in CH + PCE respect to CH for both enzymes. The ALA and n-3 LCPUFAs hepatic content was higher with CH, decreasing the levels of AA and n-6 LCPUFAs. It is concluded that the joint action of flavonoids such as anthocyanins and ALA show an anti-adipogenic effect. Desaturase activity was inhibited by ALA and kept by the anthocyanins from PCE, thus anthocyanins would exert a protective effect on the desaturase activity but they would not affect on its gene expression, however, high doses of ALA increased the production of its metabolites, masking the effect of PCE.


Assuntos
Suplementos Nutricionais , Ácidos Graxos Dessaturases/genética , Linoleoil-CoA Desaturase/genética , Extratos Vegetais/farmacologia , Óleos Vegetais/farmacologia , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Animais , Dieta/métodos , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Ômega-6/metabolismo , Feminino , Regulação da Expressão Gênica , Linoleoil-CoA Desaturase/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Azeite de Oliva/farmacologia , PPAR alfa/genética , PPAR alfa/metabolismo , Extratos Vegetais/química , Óleos Vegetais/isolamento & purificação , Ratos , Ratos Sprague-Dawley , Salvia/química , Proteína de Ligação a Elemento Regulador de Esterol 1/antagonistas & inibidores , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Zea mays/química , Ácido alfa-Linoleico/farmacologia
13.
Mol Nutr Food Res ; 62(9): e1701007, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29579359

RESUMO

SCOPE: We investigated the interaction between streptozotocin (STZ)-induced diabetes and dietary n6/n3 ratio, and its influence on lipogenesis. METHODS AND RESULTS: The animals were treated with STZ and fed with different dietary n6/n3 ratios: 1, 7, and 60, or supplemented with DHA/EPA. Gene expression was assessed by RT-PCR and protein expression by western blotting and immunohistochemistry. Fatty acid profile was determined by GC-MS. Pancreas and liver histology were assessed by hematoxylin and eosin (H&E) staining. STZ-induced characteristic changes in all STZ treated groups, including: increased blood glucose, decreased body mass, increased lipid peroxidation and CD36 expression, decreased 16:1n7 and 18:1n7, increases in 20:3n6, decreases in phospholipid (PL) content of 20:4n6, as well as decreases in the expression of SREBP1c, Δ-9-desaturase (Δ9D), and Δ-5-desaturase (Δ5D). Additionally, other changes occurred that were dependent on the n6/n3 ratio. Among the diabetic groups, the lower n6/n3 ratio caused higher lipid peroxidation and CD36 expression, a greater decrease in 20:4n6 and decreased Δ6-desaturase (Δ6D) expression, while the higher n6/n3 ratio caused increased partitioning of 20:4n6 into hepatic neutral lipids (NL), a decrease in 20:5n3 content, and increased ß-oxidation. CONCLUSION: Presented data suggest that the n6/n3 ratio could significantly influence lipogenesis, lipid peroxidation, and ß-oxidation in STZ-induced diabetes, which could have clinical significance.


Assuntos
Encéfalo/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-6/administração & dosagem , Regulação Enzimológica da Expressão Gênica , Fígado/enzimologia , Animais , Encéfalo/patologia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/patologia , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácidos Docosa-Hexaenoicos/sangue , Ácidos Docosa-Hexaenoicos/metabolismo , Ácido Eicosapentaenoico/administração & dosagem , Ácido Eicosapentaenoico/sangue , Ácido Eicosapentaenoico/metabolismo , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Ômega-3/sangue , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Ômega-6/sangue , Ácidos Graxos Ômega-6/metabolismo , Linoleoil-CoA Desaturase/genética , Linoleoil-CoA Desaturase/metabolismo , Peroxidação de Lipídeos , Fígado/metabolismo , Fígado/patologia , Masculino , Neurônios/metabolismo , Neurônios/patologia , Pâncreas/metabolismo , Pâncreas/patologia , Distribuição Aleatória , Ratos Wistar , Estearoil-CoA Dessaturase/genética , Estearoil-CoA Dessaturase/metabolismo , Estreptozocina
14.
Microb Cell Fact ; 17(1): 7, 2018 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-29331150

RESUMO

Dunaliella salina is a unicellular green alga with a high α-linolenic acid (ALA) level, but a low eicosapentaenoic acid (EPA) level. In a previous analysis of the catalytic activity of delta 6 fatty acid desaturase (FADS6) from various species, FADS6 from Thalassiosira pseudonana (TpFADS6), a marine diatom, showed the highest catalytic activity for ALA. In this study, to enhance EPA production in D. salina, FADS6 from D. salina (DsFADS6) was identified, and substrate specificities for DsFADS6 and TpFADS6 were characterized. Furthermore, a plasmid harboring the TpFADS6 gene was constructed and overexpressed in D. salina. Our results revealed that EPA production reached 21.3 ± 1.5 mg/L in D. salina transformants. To further increase EPA production, myoinositol (MI) was used as a growth-promoting agent; it increased the dry cell weight of D. salina transformants, and EPA production reached 91.3 ± 11.6 mg/L. The combination of 12% CO2 aeration with glucose/KNO3 in the medium improved EPA production to 192.9 ± 25.7 mg/L in the Ds-TpFADS6 transformant. We confirmed that the increase in ALA was optimal at 8 °C; the EPA percentage reached 41.12 ± 4.78%. The EPA yield was further increased to 554.3 ± 95.6 mg/L by supplementation with 4 g/L perilla seed meal (PeSM), 500 mg/L MI, and 12% CO2 aeration with glucose/KNO3 at varying temperatures. EPA production and the percentage of EPA in D. salina were 343.8-fold and 25-fold higher than those in wild-type D. salina, respectively. IMPORTANCE: FADS6 from Thalassiosira pseudonana, which demonstrates high catalytic activity toward α-linolenic acid, was used to enhance EPA production by Dunaliella salina. Transformation of FADS6 from Thalassiosira pseudonana into Dunaliella salina with myoinositol, CO2, low temperatures, and perilla seed meal supplementation substantially increased EPA production in Dunaliella salina to 554.3 ± 95.6 mg/L. Accordingly, D. salina could be a potential alternative source of EPA and is suitable for its large-scale production.


Assuntos
Clorófitas/enzimologia , Clorófitas/metabolismo , Ácido Eicosapentaenoico/biossíntese , Linoleoil-CoA Desaturase/metabolismo , Ácido alfa-Linoleico/metabolismo , Dióxido de Carbono/farmacologia , Clorófitas/efeitos dos fármacos , Clorófitas/genética , Diatomáceas/genética , Diatomáceas/metabolismo , Ácido Eicosapentaenoico/análise , Ácido Eicosapentaenoico/genética , Ácido Eicosapentaenoico/metabolismo , Glucose/farmacologia , Inositol/farmacologia , Perilla/química , Plasmídeos , Especificidade por Substrato , Temperatura , Ácido alfa-Linoleico/análise
15.
Nutrition ; 45: 49-58, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29129237

RESUMO

OBJECTIVES: Iron is involved in processes involving oxygen transfer and utilization. Excess iron is linked to cardiovascular diseases and some types of cancer. Iron overload is associated with oxidative stress development, and may have important interactions with lipid metabolism in the liver favoring the development and progression of non-alcoholic fatty liver disease. The aim of the study described here was to assess the effect of high intake of iron on oxidative stress-related parameters, lipid metabolism, and levels of long-chain polyunsaturated fatty acids (LCPUFAs) in liver and other tissues of the rat. METHODS: Male Wistar rats (21 d old) were fed an iron-rich diet (200 mg iron/kg diet, IRD) versus a control diet (50 mg iron/kg diet; CD) for 21 d. Samples of erythrocytes, liver, adipose tissue, brain, heart, and testicles were evaluated for fatty acid composition and hepatic biochemical and oxidative stress parameters, Δ-6 and Δ-5 desaturase activities, SREBP-1c and PPAR-α mRNA expression and DNA-binding capacity, and lipolytic, lipogenic, and antioxidant enzymatic activities. RESULTS: The IRD caused liver steatosis and increased activity of plasma transaminases, with higher oxidative stress status in plasma and liver. Liver Δ-6 and Δ-5 desaturase exhibited decreased activity, but enhanced expression in response to the IRD compared with the CD, with lower levels of ω-3 and ω-6 LCPUFAs and higher expression and DNA binding of SREBP-1c, whereas expression and DNA-binding activity of PPAR-α were diminished. CONCLUSIONS: IRD induced oxidative stress and a reduction in the desaturation capacity of the liver, with LCPUFA depletion in the different tissues studied, thus promoting a pro-steatotic condition in the liver.


Assuntos
Ácidos Graxos Ômega-3/sangue , Ácidos Graxos Ômega-6/sangue , Sobrecarga de Ferro/fisiopatologia , Ferro/efeitos adversos , Lipogênese , Estresse Oxidativo , Animais , Catalase/genética , Catalase/metabolismo , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Glutationa Redutase/genética , Glutationa Redutase/metabolismo , Ferro/administração & dosagem , Linoleoil-CoA Desaturase/genética , Linoleoil-CoA Desaturase/metabolismo , Fígado/metabolismo , Masculino , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/etiologia , PPAR alfa/genética , PPAR alfa/metabolismo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
16.
Biotechnol Lett ; 40(3): 577-584, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29288354

RESUMO

OBJECTIVES: To express a Δ6-desaturase gene and produce gamma-linolenic acid (GLA) and stearidonic acid (SDA) in prokaryotic expression system (Escherichia coli), and analyze its substrate specificity in the omega-3 fatty acid biosynthetic pathway. RESULTS: Full-length ORF (1448 bp) of Δ6Des-Iso was isolated from Isochrysis sp. and characterized using multiple sequence alignment, phylogenetic analysis, transmembrane domain, and protein tertiary structure. Δ6Des-Iso is a front-end desaturase consisting of three conserved histidine domains and a cytochrome b5 domain. Δ6Des-Iso was cloned and expressed in E. coli with the production of GLA and SDA. Recombinant E. coli utilized 27 and 8% of exogenously supplied alpha-linolenic acid (ALA) and linoleic acid (LA) to produce 6.3% of SDA and 2.3% of GLA, respectively, suggesting that isolated Δ6Des-Iso is specific to the omega-3 pathway. CONCLUSION: For the first time production of GLA and SDA in a prokaryotic system was achieved.


Assuntos
Ácidos Graxos Insaturados/metabolismo , Haptófitas/enzimologia , Linoleoil-CoA Desaturase/metabolismo , Microalgas/enzimologia , Proteínas Recombinantes/metabolismo , Escherichia coli/genética , Ácidos Graxos Insaturados/química , Haptófitas/genética , Linoleoil-CoA Desaturase/química , Linoleoil-CoA Desaturase/genética , Microalgas/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Especificidade por Substrato
17.
J Clin Lipidol ; 12(2): 311-320.e3, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29246731

RESUMO

BACKGROUND: Numbers of single nucleotide polymorphisms (SNPs) associated with fatty acid desaturase activities have been previously identified within the FADS1-FADS2 gene cluster, which encodes delta-5 (D5D) and delta-6 (D6D) desaturases, respectively. OBJECTIVE: We aimed at further characterizing the genetic variability associated with D5D and D6D activities on a genome-wide scale. METHODS: We conducted a genome-wide association study of D5D and D6D activities in a cohort of 141 individuals from the greater Quebec City metropolitan area using the Illumina HumanOmni5-Quad BeadChip. Estimates of D5D and D6D activities were computed using product-to-precursor fatty acid ratios, arachidonic acid (AA)/dihomo-gamma-linolenic acid (DGLA) for D5D, and DGLA/linoleic acid (LA) for D6D. Levels of fatty acids were measured by gas chromatography in plasma phospholipids. RESULTS: We identified 24 previously reported SNPs associated with fatty acid levels and desaturase activities as significantly associated with D5D activity within the FADS1-FADS2 gene cluster (lead SNP rs174566/A>G). Furthermore, we identified 5 novel loci potentially associated with D5D activity at chromosomes 1, 6, 4, 8 and 19. A novel SNP associated with D6D activity and mapped to the ARHGEF10 locus (rs2280885/A>G) was identified, with carriers of the rare allele showing a significant increase in D6D activity and plasma triglyceride levels. After multiple testing correction by permutation, only rs174566 and rs2280885 remained significantly associated to D5D and D6D activity estimates, respectively. CONCLUSIONS: These results confirm previous genetic associations within the FADS1-FADS2 gene cluster with D5D activity. A novel genetic variation associated with higher D6D activity within the ARHGEF10 gene is potentially altering plasma triglyceride levels.


Assuntos
Predisposição Genética para Doença/genética , Hipertrigliceridemia/genética , Linoleoil-CoA Desaturase/genética , Polimorfismo de Nucleotídeo Único , Fatores de Troca de Nucleotídeo Guanina Rho/genética , Adulto , Feminino , Perfilação da Expressão Gênica , Frequência do Gene , Estudo de Associação Genômica Ampla/métodos , Genótipo , Humanos , Hipertrigliceridemia/enzimologia , Linoleoil-CoA Desaturase/metabolismo , Masculino , Triglicerídeos/sangue , Adulto Jovem
18.
J Lipid Res ; 59(1): 79-88, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29167410

RESUMO

Delta 6 desaturase (FADS2) is a critical bifunctional enzyme required for PUFA biosynthesis. In some organisms, FADS2s have high substrate specificity, whereas in others, they have high catalytic activity. Previously, we analyzed the molecular mechanisms underlying high FADS2 substrate specificity; in this study, we assessed those underlying the high catalytic activity of FADS2s from Glossomastix chrysoplasta and Thalassiosira pseudonana To understand the structural basis of this catalytic activity, GcFADS2 and TpFADS2 sequences were divided into nine sections, and a domain-swapping approach was applied to examine the role of each section in facilitating the catalytic activity of the overall protein. The results revealed two regions essential to this process: one that extends from the end of the fourth to the beginning of the fifth cytoplasmic transmembrane domain, and another that includes the C-terminal region that occurs after the sixth cytoplasmic transmembrane domain. Based on the domain-swapping analyses, the amino acid residues at ten sites were identified to differ between the GcFADS2 and TpFADS2 sequences, and therefore further analyzed by site-directed mutagenesis. T302V, S322A, Y375F, and M384S/M385 substitutions in TpFADS2 significantly affected FADS2 catalytic efficiency. This study offers a solid basis for in-depth understanding of catalytic efficiency of FADS2.


Assuntos
Biocatálise , Diatomáceas/enzimologia , Eucariotos/enzimologia , Linoleoil-CoA Desaturase/metabolismo , Linoleoil-CoA Desaturase/genética , Mutagênese Sítio-Dirigida
19.
J Lipid Res ; 59(1): 123-136, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29167412

RESUMO

DHA is important for fetal neurodevelopment. During pregnancy, maternal plasma DHA increases, but the mechanism is not fully understood. Using rats fed a fixed-formula diet (DHA as 0.07% total energy), plasma and liver were collected for fatty acid profiling before pregnancy, at 15 and 20 days of pregnancy, and 7 days postpartum. Phosphatidylethanolamine methyltransferase (PEMT) and enzymes involved in PUFA synthesis were examined in liver. Ad hoc transcriptomic and lipidomic analyses were also performed. With pregnancy, DHA increased in liver and plasma lipids, with a large increase in plasma DHA between day 15 and day 20 that was mainly attributed to an increase in 16:0/DHA phosphatidylcholine (PC) in liver (2.6-fold) and plasma (3.9-fold). Increased protein levels of Δ6 desaturase (FADS2) and PEMT at day 20 and increased Pemt expression and PEMT activity at day 15 suggest that during pregnancy, both DHA synthesis and 16:0/DHA PC synthesis are upregulated. Transcriptomic analysis revealed minor changes in the expression of genes related to phospholipid synthesis, but little insight on DHA metabolism. Hepatic PEMT appears to be the mechanism for increased plasma 16:0/DHA PC, which is supported by increased DHA biosynthesis based on increased FADS2 protein levels.


Assuntos
Linoleoil-CoA Desaturase/sangue , Fosfatidilcolinas/sangue , Fosfatidiletanolamina N-Metiltransferase/sangue , Gravidez/sangue , Animais , Feminino , Linoleoil-CoA Desaturase/metabolismo , Fosfatidilcolinas/metabolismo , Fosfatidiletanolamina N-Metiltransferase/metabolismo , Ratos , Ratos Sprague-Dawley
20.
Anim Biotechnol ; 29(3): 161-173, 2018 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-28657495

RESUMO

Fish are an important source of highly unsaturated fatty acids (HUFA) such as eicosapentaenoic acid EPA (20:5 n-3) and docosahexaenoic acid DHA (22:6 n-3) and play a significant role in human nutrition. The fatty acyl delta6-desaturase (Δ6 desaturase) is a rate-limiting enzyme in the biosynthetic pathway of highly unsaturated fatty acids (HUFA) that converts polyunsaturated fatty acids (PUFA) such as linoleic (18:2n-6) and α-linolenic (18:3n-3) acids into HUFA. In this study, fatty acyl Δ6 desaturase was identified from pangasius (Pangasianodon hypophthalmus) and further analyzed for sequenced-based characterization and 3D structural conformation. Sequenced-based analysis revealed some important secondary information such as physicochemical property. e.g., isoelectric point, extinction coefficient, aliphatic index, and grand average hydropathy, among others, and also post-translational modification sites were identified. An evolutionary-conserved stretch of amino acid residue and a functionally significant conserved structural ancestor, N-terminal cytochrome b5 and membrane FADS-like superfamily, were identified. Protein association analysis showed a high confidence score with acyl-CoA synthetase, elovl5, elovl2, and phospholipase A2. Herein, we report, for the first time, a 3D native structure of Δ6 desaturase protein by homology modeling approach; molecular docking analysis was performed with linoleic (18:2n-6) and α-linolenic (18:3n-3) acids, which are the two key substrates in the HUFA biosynthetic pathway. This work provides insight into the structural and functional characterization of Δ6 desaturase, which is involved in HUFA biosynthesis as a rate-limiting enzyme.


Assuntos
Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/metabolismo , Linoleoil-CoA Desaturase/química , Linoleoil-CoA Desaturase/metabolismo , Sequência de Aminoácidos , Animais , Peixes-Gato , Ácidos Docosa-Hexaenoicos/química , Ácidos Docosa-Hexaenoicos/metabolismo , Ácido Eicosapentaenoico/química , Ácido Eicosapentaenoico/metabolismo , Simulação de Acoplamento Molecular , Ligação Proteica , Domínios Proteicos
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