scholarly journals Influence of N-limitation on Malic Enzyme Isoforms and Lipogenesis of Cunninghamella bainieri 2A1

2014 ◽  
Vol 67 (1) ◽  
Author(s):  
Aidil Abdul Hamid ◽  
Shuwahida Shuib ◽  
Ekhlass M. Taha ◽  
Othman Omar ◽  
Mohd Sahaid Khalil ◽  
...  
Keyword(s):  
Lipid Content ◽  
Lipid Accumulation ◽  
Malic Enzyme ◽  
Lipid Synthesis ◽  
Lower Activity ◽  
Ammonium Tartrate ◽  
Ammonium Ions ◽  
Activity Staining ◽  
N Limitation ◽  
Enzyme Isoforms

The influence of the presence of ammonium ions in growth culture on malic enzyme (ME) isoforms activity and lipogenesis in Cunninghamella bainieri 2A1 was investigated. The fungus was cultivated in a nitrogen-limiting medium for 120 h at 30oC under two conditions. One of the cultures was intermittently fed with ammonium tartrate to maintain the ammonium concentrations above 0.5 g/L. The second culture was performed without any feeding to allow N limitation, thus promoting lipid accumulation. Activity staining of ME isoforms was carried out for both cultures. The culture which was not intermittently fed with ammonium tartrate achieved a maximum lipid content of 35% (g/g biomass) at 48 h. This culture possessed five ME isoforms (A, B, C, D and E) with isoform E showing a parallel correlation to lipid accumulation profile. In contrast, intensity of bands representing isoform D decreased as lipid accumulated. No appreciable differences of all other isoforms were observed. However, the culture which was intermittently fed with ammonium tartrate, accumulated only up to 16% lipid (g/g biomass). All isoforms were present but with a more pronounced activity of isoform D and a lower activity of isoform E was observed. These findings support further evidence that isoform E is the key isoform for lipid synthesis in C. bainieri 2A1.

scholarly journals Strategic Feeding of Ammonium and Metal Ions for Enhanced GLA-Rich Lipid Accumulation inCunninghamella bainieri2A1

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Shuwahida Shuib ◽  
Wan Nazatul Naziah Wan Nawi ◽  
Ekhlass M. Taha ◽  
Othman Omar ◽  
Abdul Jalil Abdul Kader ◽  
...  
Keyword(s):  
Metal Ions ◽  
Lipid Content ◽  
Lipid Accumulation ◽  
Malic Enzyme ◽  
Fatty Acid Synthase ◽  
Ammonium Tartrate ◽  
Atp Citrate Lyase ◽  
Enzymes Activities ◽  
Citrate Lyase ◽  
Strategic Feeding

Strategic feeding of ammonium and metal ions (Mg2+, Mn2+, Fe3+, Cu2+, Ca2+, Co2+, and Zn2+) for enhanced GLA-rich lipid accumulation inC. bainieri2A1 was established. When cultivated in nitrogen-limited medium, the fungus produced up to 30% lipid (g/g biomass) with 12.9% (g/g lipid) GLA. However, the accumulation of lipid stopped at 48 hours of cultivation although glucose was abundant. This event occurred in parallel to the diminishing activity of malic enzyme (ME), fatty acid synthase (FAS), and ATP citrate lyase (ACL) as well as the depletion of metal ions in the medium. Reinstatement of the enzymes activities was achieved by feeding of ammonium tartrate, but no increment in the lipid content was observed. However, increment in lipid content from 32% to 50% (g/g biomass) with 13.2% GLA was achieved when simultaneous feeding of ammonium, glucose, and metal ions was carried out. This showed that the cessation of lipid accumulation was caused by diminishing activities of the enzymes as well as depletion of the metal ions in the medium. Therefore, strategic feeding of ammonium and metal ions successfully reinstated enzymes activities and enhanced GLA-rich lipid accumulation inC. bainieri2A1.

scholarly journals A Mathematical Model of Neutral Lipid Content in terms of Initial Nitrogen Concentration and Validation in Coelastrum sp. HA-1 and Application in Chlorella sorokiniana

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Zhenhua Yang ◽  
Yue Zhao ◽  
Zhiyong Liu ◽  
Chenfeng Liu ◽  
Zhipeng Hu ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Lipid Content ◽  
Lipid Accumulation ◽  
Nitrogen Concentration ◽  
Lipid Production ◽  
Lipid Synthesis ◽  
Quantitative Relationship ◽  
Chlorella Sorokiniana ◽  
High Lipid ◽  
Nitrogen Concentrations

Microalgae are considered to be a potential major biomass feedstock for biofuel due to their high lipid content. However, no correlation equations as a function of initial nitrogen concentration for lipid accumulation have been developed for simplicity to predict lipid production and optimize the lipid production process. In this study, a lipid accumulation model was developed with simple parameters based on the assumption protein synthesis shift to lipid synthesis by a linear function of nitrogen quota. The model predictions fitted well for the growth, lipid content, and nitrogen consumption of Coelastrum sp. HA-1 under various initial nitrogen concentrations. Then the model was applied successfully in Chlorella sorokiniana to predict the lipid content with different light intensities. The quantitative relationship between initial nitrogen concentrations and the final lipid content with sensitivity analysis of the model were also discussed. Based on the model results, the conversion efficiency from protein synthesis to lipid synthesis is higher and higher in microalgae metabolism process as nitrogen decreases; however, the carbohydrate composition content remains basically unchanged neither in HA-1 nor in C. sorokiniana.

scholarly journals Transcriptional profiling reveals differentially expressed genes involved in lipid biosynthesis during cacao seed development

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Fupeng Li ◽  
Baoduo Wu ◽  
Lin Yan ◽  
Chaoyun Hao ◽  
Xiaowei Qin ◽  
...  
Keyword(s):  
Differentially Expressed Genes ◽  
Lipid Content ◽  
Lipid Accumulation ◽  
Unsaturated Fatty Acids ◽  
Transcriptional Profiling ◽  
Lipid Production ◽  
Economic Value ◽  
Lipid Synthesis ◽  
Differentially Expressed ◽  
Seed Lipid

AbstractTheobroma cacao is a plant of economic value due to the use of its seed lipid for chocolate, confectionery, and cosmetic industries. The seed lipid contains a stable ratio of saturated and unsaturated fatty acids, which determines its unique melting temperature. However, little is known about the molecular mechanism determining the fatty acid ratio and lipid content in cacao. To gain insight into the unique properties of lipid synthesis in cacao, biochemical and transcriptomic approaches were used to compare the lipid accumulation between high and low lipid content cacao accessions. Lipid accumulation rates and lipid content were different between the two accessions. Moreover, differentially expressed genes were detected between high and low lipid content cacao accessions. The data allowed the identification of distinct candidate genes and furthered our understanding of lipid accumulation, potentially explaining the differences in lipid content between various cacao accessions. The results might be used to develop molecular tools and engineer alternative pathways for cacao breeding with improved lipid production potentials.

scholarly journals The role of malic enzyme in the regulation of lipid accumulation in filamentous fungi

Microbiology ◽  
1999 ◽  
Vol 145 (8) ◽  
pp. 1911-1917 ◽  
Author(s):  
James P. Wynn ◽  
Aidil bin Abdul Hamid ◽  
Colin Ratledge
Keyword(s):  
Filamentous Fungi ◽  
Lipid Accumulation ◽  
Malic Enzyme

scholarly journals Snf1 Is a Regulator of Lipid Accumulation in Yarrowia lipolytica

2013 ◽  
Vol 79 (23) ◽  
pp. 7360-7370 ◽  
Author(s):  
John Seip ◽  
Raymond Jackson ◽  
Hongxian He ◽  
Quinn Zhu ◽  
Seung-Pyo Hong
Keyword(s):  
Yarrowia Lipolytica ◽  
Lipid Accumulation ◽  
Oleaginous Yeast ◽  
De Novo ◽  
Lipid Synthesis ◽  
Omega 3 ◽  
Wild Type ◽  
Content Type ◽  
Reverse Transcription Pcr ◽  
Dry Cell Weight

ABSTRACTIn the oleaginous yeastYarrowia lipolytica,de novolipid synthesis and accumulation are induced under conditions of nitrogen limitation (or a high carbon-to-nitrogen ratio). The regulatory pathway responsible for this induction has not been identified. Here we report that the SNF1 pathway plays a key role in the transition from the growth phase to the oleaginous phase inY. lipolytica. Strains with aY. lipolyticasnf1(Ylsnf1) deletion accumulated fatty acids constitutively at levels up to 2.6-fold higher than those of the wild type. When introduced into aY. lipolyticastrain engineered to produce omega-3 eicosapentaenoic acid (EPA),Ylsnf1deletion led to a 52% increase in EPA titers (7.6% of dry cell weight) over the control. Other components of theY. lipolyticaSNF1 pathway were also identified, and their function in limiting fatty acid accumulation is suggested by gene deletion analyses. Deletion of the gene encoding YlSnf4, YlGal83, or YlSak1 significantly increased lipid accumulation in both growth and oleaginous phases compared to the wild type. Furthermore, microarray and quantitative reverse transcription-PCR (qRT-PCR) analyses of theYlsnf1mutant identified significantly differentially expressed genes duringde novolipid synthesis and accumulation inY. lipolytica. Gene ontology analysis found that these genes were highly enriched with genes involved in lipid metabolism. This work presents a new role for Snf1/AMP-activated protein kinase (AMPK) pathways in lipid accumulation in this oleaginous yeast.

scholarly journals miR-15b negatively correlates with lipid metabolism in mammary epithelial cells

2018 ◽  
Vol 314 (1) ◽  
pp. C43-C52 ◽  
Author(s):  
Meiqiang Chu ◽  
Yong Zhao ◽  
Shuai Yu ◽  
Yanan Hao ◽  
Pengfei Zhang ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Epithelial Cells ◽  
Steroid Hormones ◽  
Lipid Content ◽  
Mammary Epithelial Cells ◽  
Lipid Production ◽  
Fatty Acid Synthetase ◽  
Lipid Synthesis ◽  
Mammary Epithelial ◽  
Lipid Formation

Mammary epithelial cells are regulated by steroid hormones, growth factors, and even microRNAs. miR-15b has been found to regulate lipid metabolism in adipocytes; however, its effects on lipid metabolism in mammary epithelial cells, the cells of lipid synthesis and secretion, are as yet unknown. The main purpose of this investigation was to explore the effect of miR-15b on lipid metabolism in mammary epithelial cells, along with the underlying mechanisms. miR-15b was overexpressed or inhibited by miRNA mimics or inhibitors; subsequently, lipid formation in mammary epithelial cells, and proteins related to lipid metabolism, were investigated. Through overexpression or inhibition of miR-15b expression, the current investigation found that miR-15b downregulates lipid metabolism in mammary epithelial cells and is expressed differentially at various stages of mouse and goat mammary gland development. Inhibition of miR-15b expression increased lipid content in mammary epithelial cells through elevation of the lipid synthesis enzyme fatty acid synthetase (FASN), and overexpression of miR-15b reduced lipid content in mammary epithelial cells with decreasing levels of FASN. Moreover, the steroid hormones estradiol and progesterone decreased miR-15b expression with a subsequent increase in lipid formation in mammary epithelial cells. The expression of miR-15b was lower during lactation and negatively correlated with lipid synthesis proteins, which suggests that it may be involved in lipid synthesis and milk production. miR-15b might be a useful target for altering lipid production and milk yield.

scholarly journals 905 FASN prevents immunogenicity of irradiated glioblastoma by inhibiting ER stress

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A950-A950
Author(s):  
Mara De Martino ◽  
Camille Daviaud ◽  
Claire Vanpouille-Box
Keyword(s):  
Er Stress ◽  
Lipid Accumulation ◽  
Fatty Acid Synthase ◽  
Immune Escape ◽  
De Novo ◽  
Lipid Synthesis ◽  
Adult Brain ◽  
Immune Recognition

BackgroundGlioblastoma (GBM) is the most aggressive and incurable adult brain tumor. Radiation therapy (RT) is an essential modality for GBM treatment and is recognized to stimulate anti-tumor immunity by inducing immunogenic cell death (ICD) subsequent to endoplasmic reticulum (ER) stress. However, RT also exacerbates potent immunosuppressive mechanisms that facilitate immune evasion. Notably, increased de novo lipid synthesis by the fatty acid synthase (FASN) is emerging as a mechanism of therapy resistance and immune escape. Here, we hypothesize that RT induces FASN to promote GBM survival and evade immune recognition by inhibiting ER stress and ICD.MethodsTo determine if lipid synthesis is altered in response to RT, we first assessed FASN expression by western blot (WB) and lipid accumulation by BODIPY staining in murine (CT2A and GL261) and human (U118) GBM cell lines. Next, FASN expression was blocked in CT2A cells using CRISPR-Cas9 or an inducible shRNA directed against Fasn to evaluate ICD and ER stress markers by ELISA, WB, and electron microscopy. Finally, CT2AshFASN cells or its non-silencing control (CT2AshNS) were orthotopically implanted and FASN knockdown was induced by feeding the mice with doxycycline. The immune contexture was determined by in situ immunofluorescence (n=3/group). Remaining mice were followed for survival (n=7/group).ResultsWe found that in vitro irradiation of GBM cells induces lipid accumulation in a dose-dependent fashion; an effect that is magnified over time lasting at least 6/7 days. Consistent with these findings, FASN expression was upregulated in irradiated GBM cells. Confirming the role of FASN, RT-induced accumulation of lipids was reverted when GBM cells were incubated with a FASN inhibitor. Next, we found that FASN ablation in CT2A cells induces mitochondria disruption and was sufficient to increase the expression of the ER stress makers BIP and CHOP. Along similar lines, shFASN enhances the secretion of the ICD markers HMGB1, IFN-beta and CXCL10 in irradiated CT2A cells. In vivo, CT2AshFASN tumors presented increased infiltration of CD11c+ cells and CD8+ T cells, consistent with prolonged mice survival (56 days vs. 28 days for CT2AshNS). Importantly, 43% of CT2AshFASN-bearing mice remained tumor-free for more than 70 days, while none of the CT2AshNS-bearing mice survived.ConclusionsAltogether, our data suggest that FASN-mediated lipid synthesis is an important mechanism to prevent ER stress, ICD, and anti-tumor immune responses in GBM. While much work remains to be done, our data propose FASN as a novel therapeutic target to overcome immunosuppression and sensitize GBM to immunotherapies.

A novel malic enzyme gene, Mime2, from Mortierella isabellina M6-22 contributes to lipid accumulation

2018 ◽  
Vol 40 (7) ◽  
pp. 1109-1118
Author(s):  
Shan Li ◽  
Lingyan Li ◽  
Xiangfeng Xiong ◽  
Xiuling Ji ◽  
Yunlin Wei ◽  
...  
Keyword(s):  
Lipid Accumulation ◽  
Malic Enzyme ◽  
Enzyme Gene ◽  
Mortierella Isabellina ◽  
Malic Enzyme Gene

Baicalin Inhibits Coxsackievirus B3 Replication by Reducing Cellular Lipid Synthesis

2020 ◽  
Vol 48 (01) ◽  
pp. 143-160 ◽  
Author(s):  
Meng-Jie Wang ◽  
Chun-Hua Yang ◽  
Yue Jin ◽  
Chang-Biao Wan ◽  
Wei-He Qian ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Viral Replication ◽  
Lipid Content ◽  
Hela Cells ◽  
Lipid Synthesis ◽  
Heart Weight ◽  
Mrna Levels ◽  
Cellular Lipid ◽  
Autophagosome Formation ◽  
Cvb3 Infection

Baicalin is a flavonoid extracted from Scutellariae Radix and shows a variety of biological activities as reducing lipids, diminishing inflammation, and inhibiting bacterial infection. However, there is no report of baicalin against CVB3 infection. In this study, we found that baicalin can reduce viral titer in a dose-dependent manner in vitro at a dose with no direct virucidal effect. Moreover, we revealed that baicalin can also improve survival rate, reduce heart weight/body weight ratio, prevent virus replication, and relieve myocardial inflammation in the acute viral myocarditis mouse model induced by CVB3. Then, in order to explore the mechanism of baicalin inhibiting CVB3 replication, we respectively examined the expression of autophagosome marker LC3-II by Western blot, tested the concentration of free fatty acid (FFA) and cholesterol (CHO) by commercial kits, detected the mRNA levels of fatty acid synthase (Fasn) and acetyl coenzyme a carboxylase (ACC) by RT-PCR, and observed the lipid content of cells by fluorescence staining. The results showed that CVB3 infection increased autophagosome formation and lipid content in HeLa cells, but these changes were significantly blocked by baicalin. Finally, in order to confirm that baicalin inhibits viral replication and reduces autophagosome formation by reducing cellular lipids, we added exogenous palmitate to cell culture supernatants to promote intracellular lipid synthesis and found that palmitate did not alter LC3-II and CVB3/VP1 expression in HeLa cells with or without CVB3 infection. Interestingly, palmitate can reverse the inhibitory effect of baicalin on autophagosome formation and viral replication. In conclusion, our results indicated that lipids play an important role in CVB3 replication, and the effect of baicalin against CVB3 was associated with its ability to reduce cellular lipid synthesis to limit autophagosome formation.

109 EFFECTS OF LIPOLYTIC AGENTS FORSKOLIN, EPINEPHRINE AND CAFFEINE ON EMBRYONIC DEVELOPMENT AND LIPID CONTENT OF BOVINE EMBRYOS PRODUCED IN VITRO

2009 ◽  
Vol 21 (1) ◽  
pp. 154 ◽  
Author(s):  
M. Barcelo-Fimbres ◽  
G. E. Seidel
Keyword(s):  
Amino Acids ◽  
Fatty Acid ◽  
Embryonic Development ◽  
Lipid Content ◽  
Lipid Accumulation ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Nile Red ◽  
Essential Amino Acids

The objective of this experiment was to evaluate lipid accumulation and embryonic development of bovine morulae treated with different chemicals. A total of 2619 slaughterhouse oocytes from heifers and mature cows were matured in CDM medium (similar to SOF) plus 0.5% fatty acid-free BSA and hormones (M-CDM) for 23 h at 38.5°C in 5% CO2 in air. Frozen–thawed sperm were centrifuged through a Percoll gradient and co-cultured with matured oocytes for 18 h in F-CDM (CDM+heparin). Zygotes were cultured at 38.5°C in 5% CO2/5% O2/90% N2 in CDM-1 with nonessential amino acids, 10 μm EDTA, 0.5% fatty acid free BSA, and 0.5 mm fructose. After 60 h, resulting 8-cell embryos were cultured 120 h in CDM-2 (CDM-1+essential amino acids and 2 mm fructose). A factorial design was used with 7 treatments, 2 ovary sources (cows v. heifers), and 3 bulls (A, B and C) replicated twice for each bull (6 replicates). At Day 2.5 embryo cleavage and 8-cell rates were evaluated, and on Day 6 a total of 755 morulae were randomly assigned to the 7 treatments (control, 2 and 8 mm caffeine, 1 and 4 μm epinephrine, and 10 and 40 μm forskolin). To quantify lipid accumulation, Day 7 blastocysts were fixed and stained with 1 μg mL–1 Nile red dye, after which a digital photograph of the equatorial part of the embryo (including the inner cell mass) was taken at 200×, and fluorescence intensity was measured with Image Pro software from 0 to 255 shades for each pixel (0 = no lipids; 255 = greatest lipid accumulation), as previously reported (Biol. Reprod. 2007 (Suppl. 1), 87–88). Data were analyzed by ANOVA. No differences in cleavage rates (75 v. 68 ± 3.6%) or eight cell rates (61 ± v. 57 ± 2.8%) were found for heifer v. cow oocytes (P > 0.1); however, blastocyst rates per oocyte and per 8-cell embryo were greater for cows than heifers (20 v. 10 ± 2.1%, and 68 v. 35 ± 3.8%, respectively; P < 0.05). Treatments: 2 and 8 mm caffeine produced fewer blastocysts per morula than 1 and 4 μm epinephrine, 10 and 40 μm forskolin and the control (39, 5 v. 54, 49, 48, 54 and 52 ± 5.8%; respectively) (P < 0.01). More lipid content was found in whole embryos and trophoblast of heifer-derived than cow blastocysts (P < 0.05), and forskolin resulted in less lipid content than control, caffeine- and epinephrine-treated morulae in whole embryos, embryonic mass and trophoblasts (P < 0.05; Table 1). In conclusion, mature cows were a better source of oocytes than feedlot heifers for embryonic development. High doses of caffeine were detrimental to embryos, and the addition of the lypolitic agent forskolin reduced lipid content relative to control, caffeine and epinephrine-treated embryos. Table 1.Main effect treatment means of lipid content (arbitrary fluorescence units)

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