Fatty acid bioconversion in harpacticoid copepods in a changing environment : a transcriptomic approach

By 2100, global warming is predicted to significantly reduce the capacity of marine primary producers for long-chain polyunsaturated fatty acid (LC-PUFA) synthesis. Primary consumers such as harpacticoid copepods (Crustacea) might mitigate the resulting adverse effects on the food web by increased LC-PUFA bioconversion. Here, we present a high-quality de novo transcriptome assembly of the copepodPlatychelipus littoralis, exposed to changes in both temperature (+3 degrees C) and dietary LC-PUFA availability. Using this transcriptome, we detected multiple transcripts putatively coding for LC-PUFA-bioconverting front-end fatty acid (FA) desaturases and elongases, and performed phylogenetic analyses to identify their relationship with sequences of other (crustacean) taxa. While temperature affected the absolute FA concentrations in copepods, LC-PUFA levels remained unaltered even when copepods were fed an LC-PUFA-deficient diet. While this suggests plasticity of LC-PUFA bioconversion withinP. littoralis, none of the putative front-end desaturase or elongase transcripts was differentially expressed under the applied treatments. Nevertheless, the transcriptome presented here provides a sound basis for future ecophysiological research on harpacticoid copepods. This article is part of the theme issue 'The next horizons for lipids as 'trophic biomarkers': evidence and significance of consumer modification of dietary fatty acids'

A transgenic Camelina sativa seed oil effectively replaces fish oil as a dietary source of eicosapentaenoic acid in mice

Background: Fish currently supplies only 40% of the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) required to allow all individuals globally to meet the minimum intake recommendation of 500 mg/d. Therefore, alternative sustainable sources are needed. Objective: The main objective was to investigate the ability of genetically engineered Camelina sativa (20% EPA) oil (CO) to enrich tissue EPA and DHA relative to an EPA-rich fish oil (FO) in mammals. Methods: Six-week-old male C57BL/6J mice were fed for 10 wk either a palm oil–containing control (C) diet or diets supplemented with EPA-CO or FO, with the C, low-EPA CO (COL), high-EPA CO (COH), low-EPA FO (FOL), and high-EPA FO (FOH) diets providing 0, 0.4, 3.4, 0.3, and 2.9 g EPA/kg diet, respectively. Liver, muscle, and brain were collected for fatty acid analysis, and blood glucose and serum lipids were quantified. The expression of selected hepatic genes involved in EPA and DHA biosynthesis and in modulating their cellular impact was determined. Results: The oils were well tolerated, with significantly greater weight gain in the COH and FOH groups relative to the C group (P < 0.001). Significantly lower (36–38%) blood glucose concentrations were evident in the FOH and COH mice relative to C mice (P < 0.01). Hepatic EPA concentrations were higher in all EPA groups relative to the C group (P < 0.001), with concentrations of 0.0, 0.4, 2.9, 0.2, and 3.6 g/100 g liver total lipids in the C, COL, COH, FOL, and FOH groups, respectively. Comparable dose-independent enrichments of liver DHA were observed in mice fed CO and FO diets (P < 0.001). Relative to the C group, lower fatty acid desaturase 1 (Fads1) expression (P < 0.005) was observed in the COH and FOH groups. Higher fatty acid desaturase 2 (Fads2), peroxisome proliferator–activated receptor α (Ppara), and peroxisome proliferator–activated receptor γ (Pparg) (P < 0.005) expressions were induced by CO. No impact of treatment on liver X receptor α (Lxra) or sterol regulatory element-binding protein 1c (Srebp1c) was evident. Conclusions: Oil from transgenic Camelina is a bioavailable source of EPA in mice. These data provide support for the future assessment of this oil in a human feeding trial

Study of the expression of different genes of long-chain polyunsaturated fatty acids (LC-PUFA) metabolism during the early paralarval development of the common octopus (Octopus vulgaris)

Dissertação de mestrado, Aquacultura e Pescas, Faculdade de Ciências e Tecnologias, Universidade do Algarve, 2015The common octopus, Octopus vulgaris, presents characteristics as high market price, high fecundity, short life cycle, rapid growth and high food conversion rates, which make this species a potential target for future aquaculture. However, two main problems have been pointed as the main causes for the high mortalities observed in the culture of this cephalopod: (i) the lack of standardized culture conditions and (ii) the absence of an appropriate diet that fulfil all the nutritional requirements of paralarvae. Particularly, the lack of a balance in lipid and fatty acid composition such as a deficiency in long-chain polyunsaturated fatty acid (LC-PUFA) has been pointed out as one of the main problems. Additionally, it has been proved that the early life stages of octopus paralarvae have high PUFA requirements. LC-PUFA are considered key factors for a suitable growth during planktonic life of octopus and are biosynthesized by enzymes called desaturases and elongases. In the present study, our main objective was to study the expression of the genes encoding for the Stearoyl-CoA Desaturase with Δ9 activity (Scd), the Fatty acyl desaturase with Δ5 activity (Fad) and the Elongases of Very Long-Chain fatty acids (Elovl5 and Elovl4), all them involved in the LC-PUFA metabolism. The expression of these genes has been analyzed through quantitative PCR (qPCR) from hatching on (day 0) and at days 5, 10, 15 and 20 of paralarval development. These specific genes are already characterized for the adult octopus. Our results revealed the presence of all these enzymes in paralarvae during all the studied period. Moreover, despite some exceptions, a tendency of an increase of the expression of these genes from day 0 to day 20 is observed. This could suggest that each enzyme is incorporated/biosynthesized when the development becomes more complex and/or when this endogenous biosynthesis capacity appears as a response to a poor diet, in order to fulfill the nutritional requirements. The high expression at day 0 observed in scd and elovl5 could also indicate that the activation of the zygote genome can occurs during the embryonic development of the common octopus, although further research will be necessary. In conclusion, this study elucidates and clarifies how these genes are expressed in octopus paralarvae during the first days of development. It will allow to fill the knowledge gaps that still exist on the culture of Octopus vulgaris, possibly contributing to reduce the high mortalities observed in the early paralarval development, and, at the same time, to help to identify the essential fatty acids for paralarvae stages.O polvo comum, Octopus vulgaris, apresenta características como o alto preço no mercado, altas taxas de fecundidade, curto ciclo de vida, crescimento rápido e altas taxas de conversão de alimento, que fazem desta espécie um grande potencial para a aquacultura. Contudo, dois grandes problemas têm sido apontados como as principais causas para as altas mortalidades observadas no cultivo deste cefalópode: (i) a falta de condições padrão no seu cultivo e (ii) a ausência de uma dieta que complete todas as necessidades nutricionais desta paralarva. Particularmente, é observado uma falta de equilíbrio na composição de lípidos e ácidos gordos na dieta, como a deficiência em ácidos gordos polinsaturados de cadeia longa (AGP-CL). Para além disso, tem vindo a ser provado que os estádios primários das paralarvas de polvo apresentam grandes necessidades em ácidos gordos polinsaturados (AGP). Os ácidos gordos polinsaturados de cadeia longa são considerados fatores chave para um bom crescimento durante a vida plantónica do polvo e são biosintetizados por enzimas designadas de desaturases e elongases. O presente estudo teve como principal objectivos o estuda da expressão dos genes que codificam a Estearoil-CoA Dessaturase com actividade Δ9 (Scd), a dessaturase de ácido gordo com actividade Δ5 (Fad) e as Elongases de ácidos gordos de cadeia longa Elovl5 e Elovl4, envolvidos no metabolismo dos AGP-CL. A expressão destes genes foi analisada através de PCR quantitativo (qPCR) a partir da eclosão (dia 0) e aos dias 5, 10, 15 e 20 do desenvolvimento das paralarvas. Estes genes em específico já foram anteriormente caraterizados em polvo adulto. Os resultados revelaram a presença de todas as enzimas nas paralarvas durante o período de tempo estudado. Além disso, e salvo algumas exceções, é observado um aumento da expressão destes genes desde o dia 0 até ao dia 20. Sugere-se que esta tendência pode ser explicada pelo facto das enzimas serem incorporadas/biosintetizadas à medida que o desenvolvimento se torna mais complexo e/ou quando a capacidade endogena de biosintetizar estas enzimas pode aparecer como resposta a uma dieta nutricionalmente pobre, de forma a preencher as necesidades nutricionais destas paralarvas. Foi também verificada uma elevada expressão dos genes scd e elovl5 ao dia 0, podendo indicar a ativação do genoma do zigoto durante o periodo embrionário do polvo comum, embora seja necessária mais pesquisa nesta linha de investigação. Concluíndo, este estudo permitiu elucidar e clarificar como estes genes se expressam nas paralarvas de polvo durante os primeiros dia de desenvolvimento, podendo ajudar na identificação dos ácidos gordos essenciais de cada estádio das paralarvas. Ao mesmo tempo, veio aumentar o conhecimento do cultivo da espécie de polvo, Octopus vulgaris, contribuindo para reduzir as elevadas mortalidades observadas nos estádio iniciais de desenvolvimento das paralarvaras

Hormone deprivation alters mitochondrial function and lipid profile in the hippocampus

Mitochondrial dysfunction is a common hallmark in aging. In the female, reproductive senescence is characterized by loss of ovarian hormones, many of whose neuroprotective effects converge upon mitochondria. The functional integrity of mitochondria is dependent on membrane fatty acid and phospholipid composition, which are also affected during aging. The effect of long-term ovarian hormone deprivation upon mitochondrial function and its putative association with changes in mitochondrial membrane lipid profile in the hippocampus, an area primarily affected during aging and highly responsive to ovarian hormones, is unknown. To this aim, Wistar adult female rats were ovariectomized or sham-operated. Twelve weeks later, different parameters of mitochondrial function (O2 uptake, ATP production, membrane potential and respiratory complex activities) as well as membrane phospholipid content and composition were evaluated in hippocampal mitochondria. Chronic ovariectomy reduced mitochondrial O2 uptake and ATP production rates and induced membrane depolarization during active respiration without altering the activity of respiratory complexes. Mitochondrial membrane lipid profile showed no changes in cholesterol levels but higher levels of unsaturated fatty acids and a higher peroxidizability index in mitochondria from ovariectomized rats. Interestingly, ovariectomy also reduced cardiolipin content and altered cardiolipin fatty acid profile leading to a lower peroxidizability index. In conclusion, chronic ovarian hormone deprivation induces mitochondrial dysfunction and changes in the mitochondrial membrane lipid profile comparable to an aging phenotype. Our study provides insights into ovarian hormone loss-induced early lipidomic changes with bioenergetic deficits in the hippocampus that may contribute to the increased risk of Alzheimer’s disease and other age-associated disorders observed in postmenopause.Fil: Zarate, Sandra Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Astiz, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Magnani, Natalia Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Imsen, Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Merino, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Alvarez, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Reines, Analia Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Seilicovich, Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

Statin-induced myopathic changes in primary human muscle cells and reversal by a prostaglandin F2 alpha analogue

Statin-related muscle side effects are a constant healthcare problem since patient compliance is dependent on side effects. Statins reduce plasma cholesterol levels and can prevent secondary cardiovascular diseases. Although statin-induced muscle damage has been studied, preventive or curative therapies are yet to be reported. We exposed primary human muscle cell populations (n = 22) to a lipophilic (simvastatin) and a hydrophilic (rosuvastatin) statin and analyzed their expressome. Data and pathway analyses included GOrilla, Reactome and DAVID. We measured mevalonate intracellularly and analyzed eicosanoid profiles secreted by human muscle cells. Functional assays included proliferation and differentiation quantification. More than 1800 transcripts and 900 proteins were differentially expressed after exposure to statins. Simvastatin had a stronger effect on the expressome than rosuvastatin, but both statins influenced cholesterol biosynthesis, fatty acid metabolism, eicosanoid synthesis, proliferation, and differentiation of human muscle cells. Cultured human muscle cells secreted ω-3 and ω-6 derived eicosanoids and prostaglandins. The ω-6 derived metabolites were found at higher levels secreted from simvastatin-treated primary human muscle cells. Eicosanoids rescued muscle cell differentiation. Our data suggest a new aspect on the role of skeletal muscle in cholesterol metabolism. For clinical practice, the addition of omega-n fatty acids might be suitable to prevent or treat statin-myopathy

Wide-gene expression analysis of lipid-relevant genes in nutritionally challenged gilthead sea bream (Sparus aurata)

Disturbances of lipid metabolism are a major problem in livestock fish and the present study analysed the different tissue expression patterns and regulations of 40 lipid-relevant genes in gilthead sea bream. Nineteen sequences, including fatty acid elongases (4), phospholipases (7), acylglycerol lipases (8) and lipase-maturating enzymes (1), were new for gilthead sea bream (GenBank, JX975700-JX975718). Up to six different lipase-related enzymes were highly expressed in adipose tissue and liver, which also showed a high expression level of δ6 and δ9 desaturases. In the brain, the greatest gene expression level was achieved by the very long chain fatty acid elongation 1, along with relatively high levels of δ9 desaturases and the phospholipase retinoic acid receptor responder. These two enzymes were also expressed at a high level in white skeletal muscle, which also shared a high expression of lipid oxidative enzymes. An overall down-regulation trend was observed in liver and adipose tissue in response to fasting following the depletion of lipid stores. The white skeletal muscle of fasted fish showed a strong down-regulation of δ9 desaturases in conjunction with a consistent up-regulation of the >lipolytic machinery> including key enzymes of tissue fatty acid uptake and mitochondrial fatty acid transport and oxidation. In contrast, the gene expression profile of the brain remained almost unaltered in fasted fish, which highlights the different tissue plasticity of lipid-related genes. Taken together, these findings provide new fish genomic resources and contribute to define the most informative set of lipid-relevant genes for a given tissue and physiological condition in gilthead sea bream. © 2014 Elsevier B.V.This research was funded by the Spanish MICINN through AQUAFAT (AGL2009-07797; predictive modelling of flesh fatty acid composition in cultured fish species with different muscle lipid contents) and AQUAGENOMICS (CSD2007-00002, improvement of aquaculture production by the use of biotechnological tools) projects. Additional funding was obtained from EU project ARRAINA (KBBE-2011-5-288925, advanced research initiatives for nutrition and aquaculture).Peer Reviewe

Modifying the lipid content and composition of plant seeds: engineering the production of LC-PUFA

Omega-3 fatty acids are characterized by a double bond at the third carbon atom from the end of the carbon chain. Latterly, long chain polyunsaturated omega-3 fatty acids such as eicosapentaenoic acid (EPA; 20:5Δ5,8,11,14,17) and docosahexanoic acid (DHA; 22:6 Δ4,7,10,13,16,19), which typically only enter the human diet via the consumption of oily fish, have attracted much attention. The health benefits of the omega-3 LC-PUFAs EPA and DHA are now well established. Given the desire for a sustainable supply of omega-LC-PUFA, efforts have focused on enhancing the composition of vegetable oils to include these important fatty acids. Specifically, EPA and DHA have been the focus of much study, with the ultimate goal of producing a terrestrial plant-based source of these so-called fish oils. Over the last decade, many genes encoding the primary LC-PUFA biosynthetic activities have been identified and characterized. This has allowed the reconstitution of the LC-PUFA biosynthetic pathway in oilseed crops, producing transgenic plants engineered to accumulate omega-3 LC-PUFA to levels similar to that found in fish oil. In this review, we will describe the most recent developments in this field and the challenges of overwriting endogenous seed lipid metabolism to maximize the accumulation of these important fatty acids

Molecular Cloning And Functional Characterization Of Blue-Spotted Mudskipper (Boleophthalmus Boddarti) Fatty Acyl Desaturase And Elongase

Asid lemak tak tepu yang berantai panjang (LC-PUFA) membawa banyak manfaat kepada manusia dan amat penting untuk fungsi tubuh dari aspek fisiologi dan pertumbuhan Long chain polyunsaturated fatty acids (LC-PUFAs) serve many important roles in human are important for physiological and developmental well bein