Browsing by Subject "Lipids"

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  • Avela, Henri F.; Siren, Heli (2020)
    The present article examines recently published literature on lipids, mainly focusing on research involving glycero-, glycerophospho- and sphingo-lipids. The primary aim is identification of distinct profiles in biologic lipidomic systems by ultra-high-performance liquid chromatography (UHPLC) coupled with mass spectrometry (MS, tandem MS) with multivariate data analysis. This review specifically targets lipid biomarkers and disease pathway mechanisms in humans and artificial targets. Different specimen matrices such as primary blood derivatives (plasma, serum, erythrocytes, and blood platelets), faecal matter, urine, as well as biologic tissues (liver, lung and kidney) are highlighted.
  • Karjalainen, Minna K.; Holmes, Michael V.; Wang, Qin; Anufrieva, Olga; Kähönen, Mika; Lehtimäki, Terho; Havulinna, Aki S.; Kristiansson, Kati; Salomaa, Veikko; Perola, Markus; Viikari, Jorma S.; Raitakari, Olli T.; Järvelin, Marjo-Riitta; Ala-Korpela, Mika; Kettunen, Johannes (2020)
    Background and aims: Apolipoprotein A-I (apoA-I) infusions represent a potential novel therapeutic approach for the prevention of coronary artery disease (CAD). Although circulating apoA-I concentrations inversely associate with risk of CAD, the evidence base of this representing a causal relationship is lacking. The aim was to assess the causal role of apoA-I using human genetics. Methods: We identified a variant (rs12225230) in APOA1 locus that associated with circulating apoA-I concentrations (p <5 x 10(-8)) in 20,370 Finnish participants, and meta-analyzed our data with a previous GWAS of apoA-I. We obtained genetic estimates of CAD from UK Biobank and CARDIoGRAMplusC4D (totaling 122,733 CAD cases) and conducted a two-sample Mendelian randomization analysis. We compared our genetic findings to observational associations of apoA-I with risk of CAD in 918 incident CAD cases among 11,535 individuals from population-based prospective cohorts. Results: ApoA-I was associated with a lower risk of CAD in observational analyses (HR 0.81; 95%CI: 0.75, 0.88; per 1-SD higher apoA-I), with the association showing a dose-response relationship. Rs12225230 associated with apoA-I concentrations (per-C allele beta 0.076 SD; SE: 0.013; p = 1.5 x 10(-9)) but not with confounders. In Mendelian randomization analyses, apoA-I was not related to risk of CAD (OR 1.13; 95%CI: 0.98,1.30 per 1-SD higher apoA-I), which was different from the observational association. Similar findings were observed using an independent ABCA1 variant in sensitivity analysis. Conclusions: Genetic evidence fails to support a cardioprotective role for apoA-I. This is in line with the cumulative evidence showing that HDL-related phenotypes are unlikely to have a protective role in CAD.
  • Pashay Ahi, Ehsan; A. Lecaudey, Laurène; Ziegelbecker, Angelika; Steiner, Oliver; A. Glabonjat, Ronald; Goessler, Walter; Lass, Achim; Sefc, Kristina M. (2020)
    Background Carotenoids contribute significantly to animal body coloration, including the spectacular color pattern diversity among fishes. Fish, as other animals, derive carotenoids from their diet. Following uptake, transport and metabolic conversion, carotenoids allocated to body coloration are deposited in the chromatophore cells of the integument. The genes involved in these processes are largely unknown. Using RNA-Sequencing, we tested for differential gene expression between carotenoid-colored and white skin regions of a cichlid fish, Tropheus duboisi "Maswa", to identify genes associated with carotenoid-based integumentary coloration. To control for positional gene expression differences that were independent of the presence/absence of carotenoid coloration, we conducted the same analyses in a closely related population, in which both body regions are white. Results A larger number of genes (n = 50) showed higher expression in the yellow compared to the white skin tissue than vice versa (n = 9). Of particular interest was the elevated expression level of bco2a in the white skin samples, as the enzyme encoded by this gene catalyzes the cleavage of carotenoids into colorless derivatives. The set of genes with higher expression levels in the yellow region included genes involved in xanthophore formation (e.g., pax7 and sox10), intracellular pigment mobilization (e.g., tubb, vim, kif5b), as well as uptake (e.g., scarb1) and storage (e.g., plin6) of carotenoids, and metabolic conversion of lipids and retinoids (e.g., dgat2, pnpla2, akr1b1, dhrs). Triglyceride concentrations were similar in the yellow and white skin regions. Extracts of integumentary carotenoids contained zeaxanthin, lutein and beta-cryptoxanthin as well as unidentified carotenoid structures. Conclusion Our results suggest a role of carotenoid cleavage by Bco2 in fish integumentary coloration, analogous to previous findings in birds. The elevated expression of genes in carotenoid-rich skin regions with functions in retinol and lipid metabolism supports hypotheses concerning analogies and shared mechanisms between these metabolic pathways. Overlaps in the sets of differentially expressed genes (including dgat2, bscl2, faxdc2 and retsatl) between the present study and previous, comparable studies in other fish species provide useful hints to potential carotenoid color candidate genes.
  • Mokkala, Kati; Juhila, Juuso; Houttu, Noora; Sorsa, Timo; Laitinen, Kirsi (2020)
    Lower level of insulin-like growth factor-binding protein (IGFBP-1) has been observed in insulin resistance, while higher level of matrix metalloproteinase-8 (MMP-8) has been linked to obesity. The aim here was to study in overweight and obese women, typically manifesting with insulin resistance, whether IGFBP-1 and MMP-8 are related to and reflect systemic low-grade inflammation, metabolism and diet. Fasting serum from overweight and obese pregnant women (n = 100) in early pregnancy were analysed for IGFBP-1, phosphorylated IGFBP-1 (phIGFBP-1) and MMP-8. High-sensitivity CRP and GlycA were used as markers for low grade inflammation. GlycA and lipids were quantified using NMR. IGFBP-1 associated negatively with GlycA, evidenced by higher concentrations in the lowest quartile (median 1.53 (IQR 1.45-1.72)) compared to the highest (1.46 (1.39-1.55)) (P = 0.03). Several lipid metabolites, particularly HDL-cholesterol, correlated inversely with phIGFBP-1 (FDR
  • Seiffert, Nina (Helsingin yliopisto, 2021)
    An increasing number of people are diagnosed with depression. One possible reason for the development of depression is faulty wiring and information processing in certain neural networks (network hypothesis) in the central nervous system. It has been shown that antidepressant drugs (ADs) can induce a juvenile-like plasticity state in the brain (iPlasticity) comparable to the plastic state of critical periods during development. iPlasticity enables the rewiring of neuronal networks in combination with environmental stimuli. At the molecular level, the binding of brain-derived neurotrophic factor (BDNF) to its high-affinity receptor tropomyosin kinase receptor B (TRKB) leads to TRKB dimerization and activation, triggering a downstream signalling cascade promoting brain plasticity. Activation of the TRKB signalling cascade is triggered by neuronal activity as well as AD treatment. Recent findings demonstrate that classical as well as rapid-onset ADs bind directly to the transmembrane domain of TRKB, leading to increased translocation of intracellularly stored TRKB to the plasma membrane and enhanced BDNF binding. Cholesterol, a sterol lipid known to regulate TRKB signalling, has been found to ensure optimal TRKB-BDNF signalling by changing the TRKB dimers’ relative orientation when altering the membrane thickness. A point mutation of TRKB tyrosine 433 to phenylalanine (TRKB.Y433F) has been found to hinder TRKB dimerization. Molecular dynamic simulations reveal that other membrane lipids are likely to participate in AD binding to TRKB. The aim of this thesis was to investigate whether lipid and drug compound treatments affect TRKB dimerization in Neuro2A cells expressing TRKB. Furthermore, we assessed whether the Y433F mutation modulates TRKB dimerization in such treatments. Protein fragment complementation assay (PCA) was used as in vitro protein-protein interaction assay to quantify dimerization of overexpressed TRKB carrying two split luciferase reporter proteins. Additionally, to avoid variability caused by transient transfection and be able to test large compound libraries, the establishment of a stably TRKB-expressing N2A cell line was initiated. The results show that lipid compounds, such as Allopregnanolone, as well as ADs, such as Imipramine and (2R,6R)-Hydroxynorketamine, increased TRKB dimerization in vitro in a dose-dependent manner within 40 minutes. The increase was more pronounced in the TRKB WT-expressing cells. This indicates that the compounds tested here may be directly interacting with TRKB, facilitating dimerization. Moreover, data seem to confirm previous research on the less effective TRKB.Y433F mutation. While stable expression of TRKB carrying one of the luciferase reporter proteins was successfully achieved in a monoclonal cell line, the amount of protein expressed seems to require further optimization before utilising it for PCA. In conclusion, lipid and AD treatments can induce an increase in TRKB dimerization in a dose-dependent fashion. Further investigations are needed to determine where the compounds bind and by which mechanisms they exert their effects on TRKB. Furthermore, the work on the stable cell line will be completed to avoid variability of transient transfection in the future.
  • Kaye, Sanna; Heinonen, Sini; Pietiläinen, Kirsi (2020)
    Vertailemalla harvinaisia identtisiä mutta eripainoisia kaksosia voidaan selvittää lihavuuden vaikutusta aineenvaihduntaan DNA-sekvenssin samankaltaisuudesta riippumatta. Hankinnainen lihavuus vaikuttaa epäedullisesti veren rasvoihin, hyytymistekijöiden pitoisuuksiin ja tulehdusvälittäjäaineisiin sekä huonontaa endoteelitoimintaa ja altistaa ateroskleroosille. Tutkimusten perusteella rasvakudos on keskeisessä asemassa siinä, miten lihavuuden havaitut haitalliset aineenvaihdunnan muutokset syntyvät. Hankinnainen lihavuus liittyy rasvakudoksessa mitokondriotoiminnan heikentymiseen ja lievään tulehdukseen sekä insuliiniresistenssiin. Nämä muutokset heikentävät rasvakudoksen laajenemiskapasiteettia, jolloin ylimääräinen rasva alkaa varastoitua muihin kudoksiin, kuten maksaan, haimaan ja lihakseen, ja aiheuttaa aineenvaihdunnan laaja-alaisen häiriötilan. Erityisesti maksaan kertyvä rasva näyttää määrittävän lihavuuden haitallista metaboliaa.
  • Leiviskä, Jaana; Kouri, Timo; Pulkki, Kari (2017)
  • Hovi, Petteri; Kajantie, Eero; Soininen, Pasi; Kangas, Antti J.; Järvenpää, Anna-Liisa; Andersson, Sture; Eriksson, Johan G.; Ala-Korpela, Mika; Wehkalampi, Karoliina (2013)
  • Bhalke, Monika (Helsingin yliopisto, 2020)
    Lipoproteins are biochemical carriers of the insoluble lipids. They are complexes combining lipids and proteins for the transport of lipids. Amongst the type of lipoproteins are low-density lipoproteins (LDL) which are prevalent in various diseases such as obesity, diabetes, atherosclerosis, and other cardiovascular diseases (CVD). Omega-3 fatty acids are polyunsaturated fatty acids (PUFA) that are essential components of lipid metabolism and play a significant role in the human diet. Omega-3 PUFAs such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are derived from fish and are necessary for proper cardiovascular functioning. Because the human body is unable to produce enough quantities of some omega-3, diet is an important source for its availability. When a diet is rich in saturated fats, the above-mentioned diseases transpire. This study investigated how consumption of two fish diets, Lean fish and Fatty fish, influence the lipid species of human LDL particles. The lipid species analysed in this study are phospholipids such as phosphatidylcholine (PC), sphingomyelin (SM), and lysophosphatidylcholine (LPC), and cholesteryl esters (CE), and triacylglycerols (TAG). A total of 42 volunteers with a history of impaired fasting glucose had randomly been divided into two groups: fatty fish (4 fish meals/week) and lean fish (4 fish meals/week) for 12 weeks. Blood samples had been collected from the volunteers before and after consumption of the fish meals and LDL particles had been isolated from the blood samples by ultracentrifugation. In this study, the lipids were extracted by Folch method, and the extracted lipids were analysed using Triple quadrupole mass spectrometry. The lipid class profile did not change due to the two fish type diets. However, the consumption of fatty fish diet increased the levels of lipid species of PC, LPC, and CE containing EPA and DHA acyl chains, while decreasing levels of several TAG species. Lean fish induced minor changes in the lipid composition of LDL particles. Based on these results, fatty fish diet alters the plasma LDL lipidome profile with changes induced to both the surface and the core composition of the LDL particles in a positive way regarding cardiovascular health.
  • Lamminen, Marjukka (2021)
    Microalgae are a diverse group of microorganisms that are an interesting alternative feed resource for ruminant production. Microalgae species with high protein concentration and adequate amino acid (AA) composition can be used to substitute conventional protein feeds, whereas species with high carbohydrate or lipid concentration can be used to supply energy. Microalgal polyunsaturated acids and short-chain fatty acids have potential to improve the nutritive value of ruminant milk and meat for human consumption and mitigate enteric methane emissions. Microalgae composition is very plastid in comparison to conventional ruminant feeds and it can be influenced relatively easily by environmental conditions, such as nutrient supply. Microalgae also contain many compounds, especially carbohydrates and cell coverings, which are not usually found in ruminant feeds. Standard feed evaluation methods involving the use of crucibles or nylon bags (detergent fibre method, in vitro digestibility and in vivo rumen incubation) suit poorly to the analysis of microalgae with microscopic particle size. This paper attempts to give a general overview of the nutritive value (protein, lipids and carbohydrates) of microalgae for ruminant feeding applications and the possibilities to tailor microalgae composition for a certain ruminant feeding objectives. In addition, the key knowledge gaps related to the nutritive value of microalgae for ruminant nutrition are identified.
  • Ruppel, Meri; Eckhardt, Sabine; Pesonen, Antto; Mizohata, Kenichiro; Oinonen, Markku; Stohl, Andreas; Andersson, August; Jones, Vivienne; Manninen, Sirkku; Gustafsson, Örjan (2021)
    Black carbon (BC) particles contribute to climate warming by heating the atmosphere and reducing the albedo of snow/ice surfaces. The available Arctic BC deposition records are restricted to the Atlantic and North American sectors, for which previous studies suggest considerable spatial differences in trends. Here, we present first long-term BC deposition and radiocarbon-based source apportionment data from Russia using four lake sediment records from western Arctic Russia, a region influenced by BC emissions from oil and gas production. The records consistently indicate increasing BC fluxes between 1800 and 2014. The radiocarbon analyses suggest mainly (similar to 70%) biomass sources for BC with fossil fuel contributions peaking around 1960-1990. Backward calculations with the atmospheric transport model FLEXPART show emission source areas and indicate that modeled BC deposition between 1900 and 1999 is largely driven by emission trends. Comparison of observed and modeled data suggests the need to update anthropogenic BC emission inventories for Russia, as these seem to underestimate Russian BC emissions and since 1980s potentially inaccurately portray their trend. Additionally, the observations may indicate underestimation of wildfire emissions in inventories. Reliable information on BC deposition trends and sources is essential for design of efficient and effective policies to limit climate warming.
  • Hallamaa, Raija; Batchu, Krishna (2016)
    Background: Lipids have become an important target for searching new biomarkers typical of different autoimmune and allergic diseases. The most common allergic dermatitis of the horse is related to stings of insects and is known as insect bite hypersensitivity (IBH) or summer eczema, referring to its recurrence during the summer months. This intense pruritus has certain similarities with atopic dermatitis of humans. The treatment of IBH is difficult and therefore new strategies for therapy are needed. Autoserum therapy based on the use of serum phospholipids has recently been introduced for horses. So far, serum lipids relating to these allergic disorders have been poorly determined. The main aim of this study was to analyse phospholipid profiles in the sera of horses with allergic dermatitis and in their healthy controls and to further assess whether these lipid profiles change according to the clinical status after therapy. Methods: Sera were collected from 10 horses with allergic dermatitis and from 10 matched healthy controls both before and 4 weeks after the therapy of the affected horses. Eczema horses were treated with an autogenous preparation made from a horse's own serum and used for oral medication. Samples were analysed for their phospholipid content by liquid chromatography coupled to a triple-quadrupole mass spectrometer (LC-MS). Data of phospholipid concentrations between the groups and over the time were analysed by using the Friedman test. Correlations between the change of concentrations and the clinical status were assessed by Spearman's rank correlation test. Results: The major phospholipid classes detected were phosphatidylcholine (PC), sphingomyelin (SM), phosphatidylinositol (PI) and phosphatidylethanolamine (PE). Eczema horses had significantly lower total concentrations of PC (p <0.0001) and SM (p = 0.0115) than their healthy controls. After a 4-week therapy, no significant differences were found between the groups. Changes in SM concentrations correlated significantly with alterations in clinical signs (p = 0.0047). Conclusions: Horses with allergic dermatitis have an altered phospholipid profile in their sera as compared with healthy horses and these profiles seem to change according to their clinical status. Sphingomyelin seems to have an active role in the course of equine insect bite hypersensitivity.
  • Hekkala, Anna-Mari; Laukkanen, Jari; Airaksinen, Juhani (2021)
    • Sepelvaltimotautipotilaan ennustetta määrittää pitkälti sekundaariprevention onnistuminen – ¬siis diagnoosin varmistumisen jälkeen toteutettu pitkäaikaishoito. • Keskeisiä onnistumisen elementtejä ovat potilaan sitouttaminen näyttöön perustuvaan lääkehoitoon, ¬sydänterveellinen ruokavalio, painonhallinta, tupakoimattomuus ja liikunta. • Jokaiselle sepelvaltimotautia sairastavalle potilaalle tulisi tarjota mahdollisuus sydänvalmennukseen, ¬jonka avulla tuetaan sekundaariprevention osa-alueiden toteutumista, tarjotaan vertaistukea ja tuetaan ¬hyvää elämänlaatua. • Hoitopolkujen tulee olla katkeamattomia, jotta hoito voisi toteutua asetettujen tavoitteiden ja ¬suositusten mukaisesti.
  • FinnDiane Study Grp; Pongrac Barlovic, Drazenka; Harjutsalo, Valma; Sandholm, Niina; Forsblom, Carol; Groop, Per-Henrik (2020)
    Aims/hypothesis Lipid abnormalities are associated with diabetic kidney disease and CHD, although their exact role has not yet been fully explained. Sphingomyelin, the predominant sphingolipid in humans, is crucial for intact glomerular and endothelial function. Therefore, the objective of our study was to investigate whether sphingomyelin impacts kidney disease and CHD progression in individuals with type 1 diabetes. Methods Individuals (n = 1087) from the Finnish Diabetic Nephropathy (FinnDiane) prospective cohort study with serum sphingomyelin measured using a proton NMR metabolomics platform were included. Kidney disease progression was defined as change in eGFR or albuminuria stratum. Data on incident end-stage renal disease (ESRD) and CHD were retrieved from national registries. HRs from Cox regression models and regression coefficients from the logistic or linear regression analyses were reported per 1 SD increase in sphingomyelin level. In addition, receiver operating curves were used to assess whether sphingomyelin improves eGFR decline prediction compared with albuminuria. Results During a median (IQR) 10.7 (6.4, 13.5) years of follow-up, sphingomyelin was independently associated with the fastest eGFR decline (lowest 25%; median [IQR] for eGFR change:
  • Viitaja, Tuomo; Raitanen, Jan-Erik; Moilanen, Jukka; Paananen, Riku O.; Ekholm, Filip S. (2021)
    The tear film lipid layer (TFLL) that covers the ocular surface contains several unique lipid classes, including O-acyl-omega-hydroxy fatty acids, type I-St diesters, and type II diesters. While the TFLL represents a unique biological barrier that plays a central role in stabilizing the entire tear film, little is known about the properties and roles of individual lipid species. This is because their isolation from tear samples in sufficient quantities is a tedious task. To provide access to these species in their pure form, and to shed light on their properties, we here report a general strategy for the synthesis and structural characterization of these lipid classes. In addition, we study the organization and behavior of the lipids at the air-tear interface. Through these studies, new insights on the relationship between structural features, such as number of double bonds and the chain length, and film properties, such as spreading and evaporation resistance, were uncovered.