scholarly journals Lipid Composition and Associated Gene Expression Patterns during Pollen Germination and Pollen Tube Growth in Olive (Olea europaea L.)

2020 ◽  
Vol 61 (7) ◽  
pp. 1348-1364
Author(s):  
M Luisa Hernández ◽  
Elena Lima-Cabello ◽  
Juan de D Alché ◽  
José M Martínez-Rivas ◽  
Antonio J Castro
Keyword(s):  
Gene Expression ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Pollen Tube ◽  
Pollen Germination ◽  
De Novo ◽  
Expression Patterns ◽  
Gene Expression Patterns ◽  
Olive Pollen

Abstract Pollen lipids are essential for sexual reproduction, but our current knowledge regarding lipid dynamics in growing pollen tubes is still very scarce. Here, we report unique lipid composition and associated gene expression patterns during olive pollen germination. Up to 376 genes involved in the biosynthesis of all lipid classes, except suberin, cutin and lipopolysaccharides, are expressed in olive pollen. The fatty acid profile of olive pollen is markedly different compared with other plant organs. Triacylglycerol (TAG), containing mostly C12–C16 saturated fatty acids, constitutes the bulk of olive pollen lipids. These compounds are partially mobilized, and the released fatty acids enter the β-oxidation pathway to yield acetyl-CoA, which is converted into sugars through the glyoxylate cycle during the course of pollen germination. Our data suggest that fatty acids are synthesized de novo and incorporated into glycerolipids by the ‘eukaryotic pathway’ in elongating pollen tubes. Phosphatidic acid is synthesized de novo in the endomembrane system during pollen germination and seems to have a central role in pollen tube lipid metabolism. The coordinated action of fatty acid desaturases FAD2–3 and FAD3B might explain the increase in linoleic and alpha-linolenic acids observed in germinating pollen. Continuous synthesis of TAG by the action of diacylglycerol acyltransferase 1 (DGAT1) enzyme, but not phosphoplipid:diacylglycerol acyltransferase (PDAT), also seems plausible. All these data allow for a better understanding of lipid metabolism during the olive reproductive process, which can impact, in the future, on the increase in olive fruit yield and, therefore, olive oil production.

Acute Myeloid Leukemia with Translocation t(8;16) Demonstrates Specific Cytomorphological, Cytogenetic, and Gene Expression Characteristics and Can Clearly Be Discriminated from Other AML with Balanced Translocations.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2897-2897
Author(s):  
Torsten Haferlach ◽  
Helmut Loeffler ◽  
Alexander Kohlmann ◽  
Martin Dugas ◽  
Wolfgang Hiddemann ◽  
...  
Keyword(s):  
Gene Expression ◽  
Who Classification ◽  
De Novo ◽  
Expression Patterns ◽  
Gene Expression Pattern ◽  
Support Vector ◽  
Gene Expression Patterns ◽  
Down Regulation ◽  
Specific Expression ◽  
Balanced Translocations

Abstract Balanced chromosomal rearrangements leading to fusion genes on the molecular level define distinct biological subsets in AML. The four balanced rearrangements (t(15;17), t(8;21), inv(16), and 11q23/MLL) show a close correlation to cytomorphology and gene expression patterns. We here focused on seven AML with t(8;16)(p11;p13). This translocation is rare (7/3515 cases in own cohort). It is more frequently found in therapy-related AML than in de novo AML (3/258 t-AML, and 4/3287 de novo, p=0.0003). Cytomorphologically, AML with t(8;16) is characterized by striking features: In all 7 cases the positivity for myeloperoxidase on bone marrow smears was >70% and intriguingly, in parallel >80% of blast cells stained strongly positive for non-specific esterase (NSE) in all cases. Thus, these cases can not be classified according to FAB categories. These data suggest that AML-t(8;16) arise from a very early stem cell with both myeloid and monoblastic potential. Furthermore, we detected erythrophagocytosis in 6/7 cases that was described as specific feature in AML with t(8;16). Four pts. had chromosomal aberrations in addition to t(8;16), 3 of these were t-AML all showing aberrations of 7q. Survival was poor with 0, 1, 1, 2, 20 and 18+ (after alloBMT) mo., one lost to follow-up, respectively. We then analyzed gene expression patterns in 4 cases (Affymetrix U133A+B). First we compared t(8;16) AML with 46 AML FAB M1, 41 M4, 9 M5a, and 16 M5b, all with normal karyotype. Hierachical clustering and principal component analyses (PCA) revealed that t(8;16) AML were intercalating with FAB M4 and M5b and did not cluster near to M1. Thus, monocytic characteristics influence the gene expression pattern stronger than myeloid. Next we compared the t(8;16) AML with the 4 other balanced subtypes according to the WHO classification (t(15;17): 43; t(8;21): 40; inv(16): 49; 11q23/MLL-rearrangements: 50). Using support vector machines the overall accuracy for correct subgroup assignment was 97.3% (10-fold CV), and 96.8% (2/3 training and 1/3 test set, 100 runs). In PCA and hierarchical cluster analysis the t(8;16) were grouped in the vicinity of the 11q23 cases. However, in a pairwise comparison these two subgroups could be discriminated with an accuracy of 94.4% (10-fold CV). Genes with a specific expression in AML-t(8;16) were further investigated in pathway analyses (Ingenuity). 15 of the top 100 genes associated with AML-t(8;16) were involved in the CMYC-pathway with up regulation of BCOR, COXB5, CDK10, FLI1, HNRPA2B1, NSEP1, PDIP38, RAD50, SUPT5H, TLR2 and USP33, and down regulation of ERG, GATA2, NCOR2 and RPS20. CEBP beta, known to play a role in myelomonocytic differentiation, was also up-regulated in t(8;16)-AML. Ten additional genes out of the 100 top differentially expressed genes were also involved in this pathway with up-regulation of DDB2, HIST1H3D, NSAP1, PTPNS1, RAN, USP4, TRIM8, ZNF278 and down regulation of KIT and MBD2. In conclusion, AML with t(8;16) is a specific subtype of AML with unique characteristics in morphology and gene expression patterns. It is more frequently found in t-AML, outcome is inferior in comparison to other AML with balanced translocations. Due to its unique features, it is a candidate for inclusion into the WHO classification as a specific entity.

scholarly journals Lack of mitochondria-generated acetyl-CoA by pyruvate dehydrogenase complex downregulates gene expression in the hepatic de novo lipogenic pathway

2016 ◽  
Vol 311 (1) ◽  
pp. E117-E127 ◽  
Author(s):  
Saleh Mahmood ◽  
Barbara Birkaya ◽  
Todd C. Rideout ◽  
Mulchand S. Patel
Keyword(s):  
Gene Expression ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Pyruvate Dehydrogenase ◽  
De Novo ◽  
Pyruvate Dehydrogenase Complex ◽  
Acid Oxidation ◽  
Acetyl Coa ◽  
Key Genes ◽  
Dehydrogenase Complex

During the absorptive state, the liver stores excess glucose as glycogen and synthesizes fatty acids for triglyceride synthesis for export as very low density lipoproteins. For de novo synthesis of fatty acids from glucose, the mitochondrial pyruvate dehydrogenase complex (PDC) is the gatekeeper for the generation of acetyl-CoA from glucose-derived pyruvate. Here, we tested the hypothesis that limiting the supply of PDC-generated acetyl-CoA from glucose would have an impact on expression of key genes in the lipogenic pathway. In the present study, although the postnatal growth of liver-specific PDC-deficient (L-PDCKO) male mice was largely unaltered, the mice developed hyperinsulinemia with lower blood glucose levels in the fed state. Serum and liver lipid triglyceride and cholesterol levels remained unaltered in L-PDCKO mice. Expression of several key genes ( ACL, ACC1) in the lipogenic pathway and their upstream regulators ( LXR, SREBP1, ChREBP) as well as several genes in glucose metabolism ( Pklr, G6pd2, Pck1) and fatty acid oxidation ( FAT, Cpt1a) was downregulated in livers from L-PDCKO mice. Interestingly, there was concomitant upregulation of lipogenic genes in adipose tissue from L-PDCKO mice. Although, the total hepatic acetyl-CoA content remained unaltered in L-PDCKO mice, modified acetylation profiles of proteins in the nuclear compartment suggested an important role for PDC-generated acetyl-CoA in gene expression in de novo fatty acid synthesis in the liver. This finding has important implications for the regulation of hepatic lipid synthesis in pathological states.

Protein and gene expression patterns of endo-β-mannanase following germination of rice

2008 ◽  
Vol 18 (3) ◽  
pp. 139-149 ◽  
Author(s):  
Yanfang Ren ◽  
J. Derek Bewley ◽  
Xiaofeng Wang
Keyword(s):  
Gene Expression ◽  
Blot Analysis ◽  
De Novo ◽  
Expression Patterns ◽  
Gene Expression Patterns ◽  
Aleurone Layer ◽  
Starchy Endosperm ◽  
Rice Grains ◽  
Inactive Form ◽  
Mannanase Activity

AbstractThe rice (Oryza sativa L.) cv. Taichung 65, a japonica subspecies, was used to characterize the isoform, protein and gene expression patterns of endo-β-mannanase during and after seed germination. Activity assays and isoform analyses of whole grains or seed parts (scutellum, aleurone layer and starchy endosperm) revealed that seeds began to express endo-β-mannanase activity at 48 h from the start of imbibition at 25°C, after the completion of germination of most seeds. Three isoforms of endo-β-mannanase (pI 8.86, pI 8.92 and pI 8.98) were detected in the aleurone layer and starchy endosperm, but only two (pI 8.86 and pI 8.92) were present in the scutellum. The endo-β-mannanase in the starchy endosperm was mainly from the aleurone layer. Western blot analysis, using a tomato anti-endo-β-mannanase antibody, indicated that an endo-β-mannanase protein was present in an inactive form in dry grains. The amount of this protein decreased in the scutellum, but increased in the aleurone layer during and after germination. Thus, the increase in endo-β-mannanase activity in rice grains may be due to the activation of extant proteins and/or the de novo synthesis of the enzyme. Northern blot analysis showed that four putative rice endo-β-mannanase genes (OsMAN1, OsMAN2, OsMAN6 and OsMANP) were expressed in germinating and germinated rice grains. However, OsMANP was not expressed in the scutellum. The amount of OsMAN6 mRNA decreased after the completion of germination and paralleled the decline in endo-β-mannanase protein. In the aleurone layer, the increase of OsMAN2, OsMAN6 and OsMANP mRNA was prior to the increase of endo-β-mannanase protein.

scholarly journals A conditional mutant of the fatty acid synthase unveils unexpected cross talks in mycobacterial lipid metabolism

Open Biology ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 160277 ◽  
Author(s):  
Matías Cabruja ◽  
Sonia Mondino ◽  
Yi Ting Tsai ◽  
Julia Lara ◽  
Hugo Gramajo ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Fatty Acid Synthase ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Acid Biosynthesis ◽  
Mycolic Acids ◽  
Storage Lipids ◽  
Conditional Mutant

Unlike most bacteria, mycobacteria rely on the multi-domain enzyme eukaryote-like fatty acid synthase I (FAS I) to make fatty acids de novo. These metabolites are precursors of the biosynthesis of most of the lipids present both in the complex mycobacteria cell wall and in the storage lipids inside the cell. In order to study the role of the type I FAS system in Mycobacterium lipid metabolism in vivo , we constructed a conditional mutant in the fas-acpS operon of Mycobacterium smegmatis and analysed in detail the impact of reduced de novo fatty acid biosynthesis on the global architecture of the cell envelope. As expected, the mutant exhibited growth defect in the non-permissive condition that correlated well with the lower expression of fas-acpS and the concomitant reduction of FAS I, confirming that FAS I is essential for survival. The reduction observed in FAS I provoked an accumulation of its substrates, acetyl-CoA and malonyl-CoA, and a strong reduction of C 12 to C 18 acyl-CoAs, but not of long-chain acyl-CoAs (C 19 to C 24 ). The most intriguing result was the ability of the mutant to keep synthesizing mycolic acids when fatty acid biosynthesis was impaired. A detailed comparative lipidomic analysis showed that although reduced FAS I levels had a strong impact on fatty acid and phospholipid biosynthesis, mycolic acids were still being synthesized in the mutant, although with a different relative species distribution. However, when triacylglycerol degradation was inhibited, mycolic acid biosynthesis was significantly reduced, suggesting that storage lipids could be an intracellular reservoir of fatty acids for the biosynthesis of complex lipids in mycobacteria. Understanding the interaction between FAS I and the metabolic pathways that rely on FAS I products is a key step to better understand how lipid homeostasis is regulated in this microorganism and how this regulation could play a role during infection in pathogenic mycobacteria.

scholarly journals Cell wall, lignin and fatty acid-related transcriptome in soybean: achieving gene expression patterns for bioenergy legume

2012 ◽  
Vol 35 (1 suppl 1) ◽  
pp. 322-330 ◽  
Author(s):  
Maria Clara Pestana-Calsa ◽  
Cinthya Mirella Pacheco ◽  
Renata Cruz de Castro ◽  
Renata Rodrigues de Almeida ◽  
Nayara Patrícia Vieira de Lira ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Fatty Acid ◽  
Expression Patterns ◽  
Gene Expression Patterns

scholarly journals Mogroside V Protects against Hepatic Steatosis in Mice on a High-Fat Diet and LO2 Cells Treated with Free Fatty Acids via AMPK Activation

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Linghuan Li ◽  
Wanfang Zheng ◽  
Can Wang ◽  
Jiameng Qi ◽  
Hanbing Li
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Free Fatty Acids ◽  
Mrna Expression ◽  
Hepatic Steatosis ◽  
High Fat Diet ◽  
De Novo ◽  
Acid Oxidation ◽  
High Fat

Previous studies presented various beneficial effects of mogrosides extract from Siraitia grosvenorii, which has been included in the list of Medicine Food Homology Species in China. Mogroside V (MV) is one of the main ingredients in mogrosides extract; however, whether and how MV improves impaired lipid metabolism in the liver remains to be elucidated. Herein, we investigated the therapeutic effects of mogroside V upon hepatic steatosis in vivo and in vitro and explored the underlying mechanisms. The results showed that MV significantly ameliorated hepatic steatosis in high-fat diet- (HFD-) fed mice. Furthermore, the increased protein expression of PPAR-γ, SREBP-1, and FASN and mRNA expression of pparg, srebp1, scd1, and fasn in the liver in HFD-fed mice, which contribute to de novo lipogenesis, were dose-dependently reversed by MV treatment. Meanwhile, MV counteracted the suppressed expression of PPAR-α and CPT-1A and mRNA expression of atgl, hsl, ppara, and cpt1a, thus increasing lipolysis and fatty acid oxidation. In addition, in free fatty acids- (FFAs-) incubated LO2 cells MV downregulated de novo lipogenesis and upregulated lipolysis and fatty acid oxidation, thereby attenuating lipid accumulation, which was significantly abrogated by treatment with Compound C, an inhibitor of AMP-activated protein kinase (AMPK). Taken together, these results suggested that MV exerted a pronounced effect upon improving hepatic steatosis through regulating the disequilibrium of lipid metabolism in the liver via an AMPK-dependent pathway, providing a potential lead compound candidate for preventing nonalcoholic fatty liver disease.

scholarly journals Long-chain fatty acids and inflammation

2012 ◽  
Vol 71 (2) ◽  
pp. 284-289 ◽  
Author(s):  
Philip C. Calder
Keyword(s):  
Gene Expression ◽  
Fatty Acids ◽  
Arachidonic Acid ◽  
Fatty Acid ◽  
Inflammatory Cell ◽  
Expression Patterns ◽  
Cell Signalling ◽  
Inflammatory Cells ◽  
Membrane Phospholipids ◽  
Epa And Dha

Inflammation plays a key role in many common conditions and diseases. Fatty acids can influence inflammation through a variety of mechanisms acting from the membrane to the nucleus. They act through cell surface and intracellular receptors that control inflammatory cell signalling and gene expression patterns. Modifications of inflammatory cell membrane fatty acid composition can modify membrane fluidity, lipid raft formation and cell signalling leading to altered gene expression and can alter the pattern of lipid and peptide mediator production. Cells involved in the inflammatory response usually contain a relatively high proportion of the n-6 fatty acid arachidonic acid in their membrane phospholipids. Eicosanoids produced from arachidonic acid have well-recognised roles in inflammation. Oral administration of the marine n-3 fatty acids EPA and DHA increases the contents of EPA and DHA in the membranes of cells involved in inflammation. This is accompanied by a decrease in the amount of arachidonic acid present. EPA is a substrate for eicosanoid synthesis and these are often less potent than those produced from arachidonic acid. EPA gives rise to E-series resolvins and DHA gives rise to D-series resolvins and protectins. Resolvins and protectins are anti-inflammatory and inflammation resolving. Thus, the exposure of inflammatory cells to different types of fatty acids can influence their function and so has the potential to modify inflammatory processes.

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