Browsing by Subject "lipids"

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  • Kumpula, Linda S.; Makela, Sanna M.; Mäkinen, Ville-Petteri; Karjalainen, Anna; Liinamaa, Johanna M.; Kaski, Kimmo; Savolainen, Markku J.; Hannuksela, Minna L.; Ala-Korpela, Mika (2010)
  • Aalto, Henni (Helsingfors universitet, 2011)
    Lipids are fat soluble compounds that are derived from living tissues. Lipids have many important physiological functions. Developing methods for efficient lipid analysis is important since lipids can function as biomarkers in diseases. Additionally these methods can be used for the discovery of the biological processes of disease development. Lipids comprise of molecules with different polarity and structure. Several mass spectrometric ionization methods have been used in the analysis of lipids but they usually require sample preparation prior to the analysis. Desorption electrospray ionization-mass spectrometry (DESI-MS) and desorption photoionization-mass spectrometry (DAPPI-MS) are novel ionization methods that allow sample analysis straight from the matrix, such as tissue, usually without any sample preparation. DESI-MS has already been used in the analysis of different lipids, but DAPPI-MS has only been used in the analysis of steroids. The ionization of a range of lipid compounds (phospholipids, triglycerides, fat soluble vitamins, fatty acids, and steroids) by DAPPI-MS and DESI-MS was studied. Analysis conditions were optimized for all the different lipid classes with both DAPPI and DESI using standard samples. Some lipids were also analysed straight from pharmaceutical preparations. There were differences in the suitabilities of DAPPI-MS and DESI-MS for the ionization of different lipid classes. DAPPI-MS worked well for the ionization of nonpolar lipids like triglycerides, vitamins and fatty acids, but the phospholipids fragmented in the DAPPI-MS process and showed no molecular ion. Previous studies have shown that DESI-MS works well in the ionization of phospholipids, and this study showed that it works reasonably well for other lipid groups as well, with the exception of some of the nonpolar lipids. New knowledge was acquired especially about the suitability of DAPPI-MS for the analysis of different lipids. Based on the results it can be said that DAPPI-MS works equally well or better than DESI-MS in the ionization of most lipid classes. The DAPPI method should still be further developed so that phospholipids, which are very important lipids in human physiology, could be analysed by DAPPI-MS. As lipids were not analysed straight from a tissue sample, there are no conclusions about the suitability of DAPPI-MS for the analysis of lipids straight from tissue samples.
  • Kuang, Alan; Erlund, Iris; Herder, Christian; Westerhuis, Johan A.; Tuomilehto, Jaakko; Cornelis, Marilyn C. (2018)
    Coffee is widely consumed and contains many bioactive compounds, any of which may impact pathways related to disease development. Our objective was to identify individual lipid changes in response to coffee drinking. We profiled the lipidome of fasting serum samples collected from a previously reported single blinded, three-stage clinical trial. Forty-seven habitual coffee consumers refrained from drinking coffee for 1 month, consumed 4 cups of coffee/day in the second month and 8 cups/day in the third month. Samples collected after each coffee stage were subject to quantitative lipidomic profiling using ion-mobility spectrometry-mass spectrometry. A total of 853 lipid species mapping to 14 lipid classes were included for univariate analysis. Three lysophosphatidylcholine (LPC) species including LPC (20:4), LPC (22:1) and LPC (22:2), significantly decreased after coffee intake (p <0.05 and q <0.05). An additional 72 species mapping to the LPC, free fatty acid, phosphatidylcholine, cholesteryl ester and triacylglycerol classes of lipids were nominally associated with coffee intake (p <0.05 and q > 0.05); 58 of these decreased after coffee intake. In conclusion, coffee intake leads to lower levels of specific LPC species with potential impacts on glycerophospholipid metabolism more generally.
  • Mannisto, Ville T.; Simonen, Marko; Soininen, Pasi; Tiainen, Mika; Kangas, Antti J.; Kaminska, Dorota; Venesmaa, Sari; Kakela, Pirjo; Karja, Vesa; Gylling, Helena; Ala-Korpela, Mika; Pihlajamaki, Jussi (2014)
  • Ellul, Susan; Wake, Melissa; Clifford, Susan A.; Lange, Katherine; Würtz, Peter; Juonala, Markus; Dwyer, Terence; Carlin, John B.; Burgner, David P.; Saffery, Richard (2019)
    Objectives Nuclear magnetic resonance (NMR) metabolomics is high throughput and cost-effective, with the potential to improve the understanding of disease and risk. We examine the circulating metabolic profile by quantitative NMR metabolomics of a sample of Australian 11-12 year olds children and their parents, describe differences by age and sex, and explore the correlation of metabolites in parent-child dyads. Design The population-based cross-sectional Child Health CheckPoint study nested within the Longitudinal Study of Australian Children. Setting Blood samples collected from CheckPoint participants at assessment centres in seven Australian cities and eight regional towns; February 2015-March 2016. Participants 1180 children and 1325 parents provided a blood sample and had metabolomics data available. This included 1133 parent-child dyads (518 mother-daughter, 469 mother-son, 68 father-daughter and 78 father-son). Outcome measures 228 metabolic measures were obtained for each participant. We focused on 74 biomarkers including amino acid species, lipoprotein subclass measures, lipids, fatty acids, measures related to fatty acid saturation, and composite markers of inflammation and energy homeostasis. Results We identified differences in the concentration of specific metabolites between childhood and adulthood and in metabolic profiles in children and adults by sex. In general, metabolite concentrations were higher in adults than children and sex differences were larger in adults than in children. Positive correlations were observed for the majority of metabolites including isoleucine (CC 0.33, 95% CI 0.27 to 0.38), total cholesterol (CC 0.30, 95% CI 0.24 to 0.35) and omega 6 fatty acids (CC 0.28, 95% CI 0.23 to 0.34) in parent-child comparisons. Conclusions We describe the serum metabolite profiles from mid-childhood and adulthood in a population-based sample, together with a parent-child concordance. Differences in profiles by age and sex were observed. These data will be informative for investigation of the childhood origins of adult non-communicable diseases and for comparative studies in other populations.
  • Anttila, Pekka (Helsingin yliopisto, 2017)
    Microalgae are the most primitive and simple members of plant kingdom, unicellular or colonial and can be found worldwide. Microalgae are promising organism for producing sustainable biomass and microalgae can be used to produce proteins, lipids, colourants, vitamins and carbohydrates to food industry and can be used as feed for animals and source for biofuels. The objective of this study was to select the most effective extraction solvent and develop and optimize an accelerated solvent extraction (ASE) method for microalgal lipids. ASE is an extraction technique that needs only small amounts of solvents and uses elevated temperature and pressure for better extractability. Study had two separated parts; 1. Choosing the best solvent for ASE, 2. Optimizing extraction conditions. Study was made with two freeze dried biomasses; Euglena gracilis and Selenastrum Sp. Choosing an extraction solvent for ASE was made between acetone, ethanol and 2-ethoxyethanol and those were compared for Bligh and Dyer chloroform- methanol-water solvent extraction. Lipid yields were analyzed as total fat as sum of fatty acid methyl esters and fatty acid composition with GC-FID. Overview of lipidclasses was studied with TLC. Tocopherol analysis was made with NP-HPLC-FLD and carotenoids and chlophylls were analyzed with UV-VIS spectroscopy. Optimizing the extraction conditions was made with experimental design program with 2*15 samples in different extraction conditions with ethanol as solvent. Evaluation of results was made by total fat, omega-3 fattyacids EPA and DHA, tocopherol, carotenoid and chlorophyll contents. Optimized extraction conditions were: Temperature 125 ⁰C, Extraction time 11 min, 1 extraction cycle and Pressure 1500 psi. Temperature had the greatest effect on the studied extraction parameters.
  • InterAct Consortium; LifeLines Cohort Study Grp; de Vries, Paul S.; Brown, Michael R.; Bentley, Amy R.; Heikkinen, Sami; Koistinen, Heikki A.; Weir, David R. (2019)
    A person's lipid profile is influenced by genetic variants and alcohol consumption, but the contribution of interactions between these exposures has not been studied. We therefore incorporated gene-alcohol interactions into a multiancestry genome-wide association study of levels of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. We included 45 studies in stage 1 (genome-wide discovery) and 66 studies in stage 2 (focused follow-up), for a total of 394,584 individuals from 5 ancestry groups. Analyses covered the period July 2014-November 2017. Genetic main effects and interaction effects were jointly assessed by means of a 2-degrees-of-freedom (df) test, and a 1-df test was used to assess the interaction effects alone. Variants at 495 loci were at least suggestively associated (P <1 x 10(-6)) with lipid levels in stage 1 and were evaluated in stage 2, followed by combined analyses of stage 1 and stage 2. In the combined analysis of stages 1 and 2, a total of 147 independent loci were associated with lipid levels at P <5 x 10(-8) using 2-df tests, of which 18 were novel. No genome-wide-significant associations were found testing the interaction effect alone. The novel loci included several genes (proprotein convertase subtilisin/kexin type 5 (PCSK5), vascular endothelial growth factor B (VEGFB), and apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1 (APOBEC1) complementation factor (A1CF)) that have a putative role in lipid metabolism on the basis of existing evidence from cellular and experimental models.
  • Hunter, Kerri (Helsingfors universitet, 2013)
    Orexins are neuropeptides for which signalling effects have been noted in multiple functions of the central nervous system, and also potentially in the periphery of the body. Orexin receptors couple to a number of different proteins eliciting cellular responses such as activation/inhibition of ion channels, kinase activation, and second messenger generation, and downstream effects such as neuronal excitation, synaptic plasticity, and cell death. The majority of knowledge on orexin signalling has been obtained from recombinant expression systems, thus studies of signalling responses in specific cell or tissue types are desired. The goal of this master’s thesis project was to investigate orexin signalling in two mouse brown adipocyte precursor cell lines (C3H10T1/2 and HIB1b) with native OX1 receptor expression. p38 mitogen-activated protein kinase (MAPK) activation was assessed by western blot analysis, while phospholipase D (PLD) activity, arachidonic acid (AA) and 2-arachidonoylglycerol (2-AG) release, and adenylyl cyclase activity were assessed by radioactive prelabelling, extraction and separation of the molecular species, and quantification of radioactivity. p38 was activated by orexin in C3H10T1/2 cells, but not HIB1b cells; PLD, AA, and 2-AG showed no response to orexin; and adenylyl cyclase appears to be both stimulated and inhibited by orexin, at different concentrations. The results indicate that orexin signalling in these cell lines significantly differs from recombinantly expressed orexin receptors. This raises interesting questions regarding the variability of responses to orexin in different tissue types.
  • Akhi, R.; Wang, C.; Nissinen, A. E.; Kankaanpaa, J.; Bloigu, R.; Paju, S.; Mantyla, P.; Buhlin, K.; Sinisalo, J.; Pussinen, P. J.; Horkko, S. (2019)
    A large body of literature has established the link between periodontal disease and cardiovascular disease. Oxidized low-density lipoproteins (OxLDLs) have a crucial role in atherosclerosis progression through initiation of immunological response. Monoclonal IgM antibodies to malondialdehyde-modified low-density lipoprotein (MDA-LDL) and to malondialdehyde acetaldehyde-modified low-density lipoprotein (MAA-LDL) have been shown to cross-react with the key virulence factors of periodontal pathogens Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. We have previously shown that salivary IgA antibodies to MAA-LDL cross-react with P. gingivalis in healthy humans. In this study, we aim to assess whether oral mucosal immune response represented by salivary IgA to MAA-LDL and oral pathogens is associated with coronary artery disease (CAD). Also, the molecular mimicry through antibody cross-reaction between salivary IgA to MAA-LDL and oral pathogens was evaluated. The study subjects consisted of 451 patients who underwent a coronary angiography with no CAD (n = 133), stable CAD (n = 169), and acute coronary syndrome (ACS, n = 149). Elevated salivary IgA antibody levels to MAA-LDL, Rgp44 (gingipain A hemagglutinin domain of P. gingivalis), and Aa-HSP60 (heat shock protein 60 of A. actinomycetemcomitans) were discovered in stable-CAD and ACS patients when compared to no-CAD patients. In a multinomial regression model adjusted for known cardiovascular risk factors, stable CAD and ACS were associated with IgA to MAA-LDL (P = 0.016, P = 0.043), Rgp44 (P = 0.012, P = 0.004), Aa-HSP60 (P = 0.032, P = 0.030), Tannerella forsythia (P = 0.002, P = 0.004), Porphyromonas endodontalis (P = 0.016, P = 0.020), Prevotella intermedia (P = 0.038, P = 0.005), and with total IgA antibody concentration (P = 0.002, P = 0.016). Salivary IgA to MAA-LDL showed cross-reactivity with the oral pathogens tested in the study patients. The study highlights an association between salivary IgA to MAA-LDL and atherosclerosis. However, whether salivary IgA to MAA-LDL and the related oral humoral responses play a causal role in the development in the CAD should be elucidated in the future.
  • Taipale, Sami J.; Hiltunen, Minna; Vuorio, Kristiina; Peltomaa, Elina (2016)
    The composition and abundance of phytoplankton is an important factor defining ecological status of marine and freshwater ecosystems. Chemotaxonomic markers (e.g., pigments and fatty acids) are needed for monitoring changes in a phytoplankton community and to know the nutritional quality of seston for herbivorous zooplankton. Here we investigated the suitability of sterols along with fatty acids as chemotaxonomic markers using multivariate statistics, by analyzing the sterol and fatty acid composition of 10 different phytoplankton classes including altogether 37 strains isolated from freshwater lakes. We were able to detect a total of 47 fatty acids and 29 sterols in our phytoplankton samples, which both differed statistically significantly between phytoplankton classes. Due to the high variation of fatty acid composition among Cyanophyceae, taxonomical differentiation increased when Cyanophyceae were excluded from statistical analysis. Sterol composition was more heterogeneous within class than fatty acids and did not improve separation of phytoplankton classes when used alongside fatty acids. However, we conclude that sterols can provide additional information on the abundance of specific genera within a class which can be generated by using fatty acids. For example, whereas high C-16 omega-3 PUFA (polyunsaturated fatty acid) indicates the presence of Chlorophyceae, a simultaneous high amount of ergosterol could specify the presence of Chlamydomonas spp. (Chlorophyceae). Additionally, we found specific 4 alpha-methyl sterols for distinct Dinophyceae genera, suggesting that 4a-methyl sterols can potentially separate freshwater dinoflagellates from each other.
  • Boren, Jan; Packard, Chris J.; Taskinen, Marja-Riitta (2020)
    Cardiovascular disease (CVD) is the leading cause of death globally. It is well-established based on evidence accrued during the last three decades that high plasma concentrations of cholesterol-rich atherogenic lipoproteins are causatively linked to CVD, and that lowering these reduces atherosclerotic cardiovascular events in humans (1-9). Historically, most attention has been on low-density lipoproteins (LDL) since these are the most abundant atherogenic lipoproteins in the circulation, and thus the main carrier of cholesterol into the artery wall. However, with the rise of obesity and insulin resistance in many populations, there is increasing interest in the role of triglyceride-rich lipoproteins (TRLs) and their metabolic remnants, with accumulating evidence showing they too are causatively linked to CVD. Plasma triglyceride, measured either in the fasting or non-fasting state, is a useful index of the abundance of TRLs and recent research into the biology and genetics of triglyceride heritability has provided new insight into the causal relationship of TRLs with CVD. Of the genetic factors known to influence plasma triglyceride levels variation inAPOC3- the gene for apolipoprotein (apo) C-III - has emerged as being particularly important as a regulator of triglyceride transport and a novel therapeutic target to reduce dyslipidaemia and CVD risk (10).
  • Ollila, Hanna Maria; Utge, S; Kronholm, E; van Leeuwen, W; Silander, Kaisa; Partonen, T; Perola, Markus; Kaprio, Jaakko; Salomaa, V; Sallinen, M; Härmä, M; Porkka-Heiskanen, Tarja; Paunio, Tiina (2012)
    Epidemiological studies show association between sleep duration and lipid metabolism. In addition, inactivation of circadian genes induces insulin resistance and hyperlipidemia. We hypothesized that sleep length and lipid metabolism are partially controlled by the same genes. We studied the association of total sleep time (TST) with 60 genetic variants that had previously been associated with lipids. The analyses were performed in a Finnish population-based sample (N = 6334) and replicated in 2189 twins. Finally, RNA expression from mononuclear leucocytes was measured in 10 healthy volunteers before and after sleep restriction. The genetic analysis identified two variants near TRIB1 gene that independently contributed to both blood lipid levels and to TST (rs17321515, P = 8.92(*)10(-5), Bonferroni corrected P = 0.0053, β = 0.081 h per allele; rs2954029, P = 0.00025, corrected P = 0.015, β = 0.076; P<0.001 for both variants after adjusting for blood lipid levels or body mass index). The finding was replicated in the twin sample (rs17321515, P = 0.022, β = 0.063; meta-analysis of both samples P = 8.1(*)10(-6), β = 0.073). After the experimentally induced sleep restriction period TRIB1 expression increased 1.6-fold and decreased in recovery phase (P = 0.006). In addition, a negative correlation between TRIB1 expression and slow wave sleep was observed in recovery from sleep restriction. These results show that allelic variants of TRIB1 are independently involved in regulation of lipid metabolism and sleep. The findings give evidence for the pleiotropic nature of TRIB1 and may reflect the shared roots of sleep and metabolism. The shared genetic background may at least partially explain the mechanism behind the well-established connection between diseases with disrupted metabolism and sleep.
  • Spilling, Kristian; Seppälä, Jukka; Schwenk, Dagmar; Rischer, Heiko; Tamminen, Timo (Springer, 2021)
    Journal of Applied Phycology 33: 3
    There is a growing demand for marine omega-3 fatty acids (FAs) that is produced in high amounts by some microalgae. Here we determined the FA profiles of two cold water adapted diatoms, Chaetoceros wighamii and Thalassiosira baltica. The cultures were acclimated to different temperatures (3, 7, 11, 15, and 19 °C) and irradiance (20, 40, 130, and 450 μmol photons m−2 s−1) and the FA profiles were determined in exponential and stationary growth phases, the latter induced by different nutrient limitation (N, P, and Si). The maximum growth rate was obtained by both species at 11 °C, ≥ 130 μmol photons m−2 s−1 and was 0.8 day−1 and 0.6 day−1 for C. wighamii and T. baltica, respectively. Both species contained relatively high amounts of eicosapentaenoic acid (EPA). Thalassiosira baltica accumulated maximally ~ 30 mg EPA g−1 ash-free dry weight (AFDW) under Si-limitation. The content of docosahexaenoic acid (DHA) was lower, reaching up to 4 mg DHA g−1 AFDW in T. baltica. The concentration of EPA correlated positively with the chlorophyll a:carbon ratio, suggesting that it is bound to membranes in the photosynthetic apparatus and the EPA content in T. baltica was high enough to consider it as a potent candidate for cultivation under cold (< 15 °C) conditions. Covering a wide range of environmental conditions, the strongest differentiation in FA profiles was observed between the species with the growth phase/nutrient limitation pattern as the second most important driver of the FA composition.
  • Laanto, Elina; Mantynen, Sari; De Colibus, Luigi; Marjakangas, Jenni; Gillum, Ashley; Stuart, David I.; Ravantti, Janne J.; Huiskonen, Juha T.; Sundberg, Lotta-Riina (2017)
    Viruses have impacted the biosphere in numerous ways since the dawn of life. However, the evolution, genetic, structural, and taxonomic diversity of viruses remain poorly understood, in part because sparse sampling of the virosphere has concentrated mostly on exploring the abundance and diversity of dsDNA viruses. Furthermore, viral genomes are highly diverse, and using only the current sequence-based methods for classifying viruses and studying their phylogeny is complicated. Here we describe a virus, FLiP (Flavobacterium-infecting, lipid-containing phage), with a circular ssDNA genome and an internal lipid membrane enclosed in the icosahedral capsid. The 9,174-nt-long genome showed limited sequence similarity to other known viruses. The genetic data imply that this virus might use replication mechanisms similar to those found in other ssDNA replicons. However, the structure of the viral major capsid protein, elucidated at near-atomic resolution using cryo-electron microscopy, is strikingly similar to that observed in dsDNA viruses of the PRD1-adenovirus lineage, characterized by a major capsid protein bearing two beta-barrels. The strong similarity between FLiP and another member of the structural lineage, bacteriophage PM2, extends to the capsid organization (pseudo T = 21 dextro) despite the difference in the genetic material packaged and the lack of significant sequence similarity.