Browsing by Subject "Mass spectrometry"

Sort by: Order: Results:

Now showing items 1-20 of 23
  • Bressi, M.; Cavalli, F.; Putaud, J.P.; Fröhlich, R.; Petit, J.-E.; Aas, W.; Äijälä, M.; Alastuey, A.; Allan, J.D.; Aurela, M.; Berico, M.; Bougiatioti, A.; Bukowiecki, N.; Canonaco, F.; Crenn, V.; Dusanter, S.; Ehn, Mikael; Elsasser, M.; Flentje, H.; Graf, P.; Green, D.C.; Heikkinen, Liine; Hermann, H.; Holzinger, R.; Hueglin, C.; Keernik, H.; Kiendler-Scharr, A.; Kubelová, L.; Lunder, C.; Maasikmets, M.; Makeš, O.; Malaguti, A.; Mihalopoulos, N.; Nicolas, J.B.; O'Dowd, C.; Ovadnevaite, J.; Petralia, E.; Poulain, L.; Priestman, M.; Riffault, V.; Ripoll, A.; Schlag, P.; Schwarz, J.; Sciare, J.; Slowik, J.; Sosedova, Y.; Stavroulas, I.; Teinemaa, E.; Via, M.; Vodička, P.; Williams, P.I.; Wiedensohler, A.; Young, D.E.; Zhang, S.; Favez, O.; Minguillón, M.C.; Prevot, A.S.H. (2021)
    Similarities and differences in the submicron atmospheric aerosol chemical composition are analyzed from a unique set of measurements performed at 21 sites across Europe for at least one year. These sites are located between 35 and 62 degrees N and 10 degrees W - 26 degrees E, and represent various types of settings (remote, coastal, rural, industrial, urban). Measurements were all carried out on-line with a 30-min time resolution using mass spectroscopy based instruments known as Aerosol Chemical Speciation Monitors (ACSM) and Aerosol Mass Spectrometers (AMS) and following common measurement guidelines. Data regarding organics, sulfate, nitrate and ammonium concentrations, as well as the sum of them called non-refractory submicron aerosol mass concentration ([NR-PM1]) are discussed. NR-PM1 concentrations generally increase from remote to urban sites. They are mostly larger in the mid-latitude band than in southern and northern Europe. On average, organics account for the major part (36-64%) of NR-PM1 followed by sulfate (12-44%) and nitrate (6-35%). The annual mean chemical composition of NR-PM1 at rural (or regional background) sites and urban background sites are very similar. Considering rural and regional background sites only, nitrate contribution is higher and sulfate contribution is lower in midlatitude Europe compared to northern and southern Europe. Large seasonal variations in concentrations (mu g/m(3)) of one or more components of NR-PM1 can be observed at all sites, as well as in the chemical composition of NR-PM1 (%) at most sites. Significant diel cycles in the contribution to [NR-PM1] of organics, sulfate, and nitrate can be observed at a majority of sites both in winter and summer. Early morning minima in organics in concomitance with maxima in nitrate are common features at regional and urban background sites. Daily variations are much smaller at a number of coastal and rural sites. Looking at NR-PM1 chemical composition as a function of NR-PM1 mass concentration reveals that although organics account for the major fraction of NR-PM1 at all concentration levels at most sites, nitrate contribution generally increases with NR-PM1 mass concentration and predominates when NR-PM1 mass concentrations exceed 40 mu g/m(3) at half of the sites.
  • Itokazu, Yutaka; Tajima, Nobuyoshi; Kerosuo, Laura; Somerharju, Pentti; Sariola, Hannu; Yu, Robert K.; Kakela, Reijo (2016)
    The central nervous system (CNS) harbors multiple glial fibrillary acidic protein (GFAP) expressing cell types. In addition to the most abundant cell type of the CNS, the astrocytes, various stem cells and progenitor cells also contain GFAP+ populations. Here, in order to distinguish between two types of GFAP expressing cells with or without the expression of the A2B5 antigens, we performed lipidomic analyses on A2B5+/GFAP+ and A2B5-/GFAP+ cells from rat spinal cord. First, A2B5+/GFAP- progenitors were exposed to the leukemia inhibitory factor (LIF) or bone morphogenetic protein (BMP) to induce their differentiation to A2B5+/GFAP+ cells or A2B5-/GFAP+ astrocytes, respectively. The cells were then analyzed for changes in their phospholipid, sphingolipid or acyl chain profiles by mass spectrometry and gas chromatography. Compared to A2B5+/GFAP- progenitors, A2B5-/GFAP+ astrocytes contained higher amounts of ether phospholipids (especially the species containing arachidonic acid) and sphingomyelin, which may indicate characteristics of cellular differentiation and inability for multipotency. In comparison, principal component analyses revealed that the lipid composition of A2B5+/GFAP+ cells retained many of the characteristics of A2B5+/GFAP- progenitors, but their lipid profile was different from that of A2B5-/GFAP+ astrocytes. Thus, our study demonstrated that two GFAP+ cell populations have distinct lipid profiles with the A2B5+/GFAP+ cells sharing a phospholipid profile with progenitors rather than astrocytes. The progenitor cells may require regulated low levels of lipids known to mediate signaling functions in differentiated cells, and the precursor lipid profiles may serve as one measure of the differentiation capacity of a cell population.
  • Avela, Henri F.; Siren, Heli (2020)
    The review concentrates on the properties of analytical and statistical ultrahigh-performance liquid chromatographic (UHPLC) - mass spectrometric (MS) methods suitable for glycero-, glycerophospho- and sphingolipids in lipidomics published between the years 2017 2019. Trends and fluctuations of conventional and nano-UHPLC methods with MS and tandem MS detection were observed in context of analysis conditions and tools used for data-analysis. Whereas general workflow characteristics are agreed upon, more details related to the chromatographic methodology (i.e. stationary and mobile phase conditions) need evidently agreements. Lipid quantitation relies upon isotope-labelled standards in targeted analyses and fully standardless algorithm-based untargeted analyses. Furthermore, a wide spectrum of setups have shown potential for the elucidation of complex and large datasets by minimizing the risks of systematic misinterpretation like false positives. This kind of evaluation was shown to have increased importance and usage for cross-validation and data-analysis. (C) 2020 Elsevier B.V. All rights reserved.
  • Tähkä, Sari M.; Bonabi, Ashkan; Jokinen, Ville P.; Sikanen, Tiina M. (2017)
    This work describes aqueous and non-aqueous capillary electrophoresis on thiol-ene-based microfluidic separation devices that feature fully integrated and sharp electrospray ionization (ESI) emitters. The chip fabrication is based on simple and low-cost replica-molding of thiol-ene polymers under standard laboratory conditions. The mechanical rigidity and the stability of the materials against organic solvents, acids and bases could be tuned by adjusting the respective stoichiometric ratio of the thiol and allyl ("ene") monomers, which allowed us to carry out electrophoresis separation in both aqueous and non-aqueous (methanol- and ethanol-based) background electrolytes. The stability of the ESI signal was generally
  • Reinert, Jochim; Richard, Bernhard C.; Klafki, Hans W.; Friedrich, Beate; Bayer, Thomas A.; Wiltfang, Jens; Kovacs, Gabor G.; Ingelsson, Martin; Lannfelt, Lars; Paetau, Anders; Bergquist, Jonas; Wirths, Oliver (2016)
    In Alzheimer's disease (AD) a variety of amyloid beta-peptides (A beta) are deposited in the form of extracellular diffuse and neuritic plaques (NP), as well as within the vasculature. The generation of A beta from its precursor, the amyloid precursor protein (APP), is a highly complex procedure that involves subsequent proteolysis of APP by beta-and gamma-secretases. Brain accumulation of A beta due to impaired A beta degradation and/or altered ratios between the different A beta species produced is believed to play a pivotal role in AD pathogenesis. While the presence of A beta 40 and A beta 42 in vascular and parenchymal amyloid have been subject of extensive studies, the deposition of carboxyterminal truncated A beta peptides in AD has not received comparable attention. In the current study, we for the first time demonstrate the immunohistochemical localization of A beta 37 and A beta 39 in human sporadic AD (SAD). Our study further included the analysis of familial AD (FAD) cases carrying the APP mutations KM670/671NL, E693G and I716F, as well as a case of the PSEN1 Delta Exon9 mutation. A beta 37 and A beta 39 were found to be widely distributed within the vasculature in the brains of the majority of studied SAD and FAD cases, the latter also presenting considerable amounts of A beta 37 containing NPs. In addition, both peptides were found to be present in extracellular plaques but only scarce within the vasculature in brains of a variety of transgenic AD mouse models. Taken together, our study indicates the importance of C-terminally truncated A beta in sporadic and familial AD and raises questions about how these species are generated and regulated.
  • Kauhanen, Dimple; Sysi-Aho, Marko; Koistinen, Kaisa M.; Laaksonen, Reijo; Sinisalo, Juha; Ekroos, Kim (2016)
    Monitoring the levels of the ceramides (Cer) d18:1/16:0, Cer d18:1/18:0, Cer d18:1/24:0, and Cer d18:1/24:1 and ratios thereof in human plasma empowers the prediction of fatal outcome of coronary artery disease (CAD). We describe a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) methodology for clinical-scaled measurement of the four distinct ceramides. Rapid plasma precipitation was accomplished in 96-well format. Excellent extraction recoveries in the range of 98-109 % were achieved for each ceramide. Addition of corresponding D-7-labeled ceramide standards facilitated precise quantification of each plasma ceramide species utilizing a novel short 5-min LC-MS/MS method. Neither matrix interference nor carryover was observed. Robust intra- and inter-assay accuracy and precision <15 % at five different concentrations were obtained. Linear calibration lines with regressions, R (2) > 0.99, were achieved for all analytes. Short-term bench top, long-term plasma, and extract stability demonstrated that the distinct ceramides were stable in the conditions evaluated. The validity of the methodology was demonstrated by determining the precise ceramide concentrations in a small CAD case-control study. Thus, our LC-MS/MS methodology features simple sample preparation and short analysis time for accurate quantification of Cer d18:1/16:0, Cer d18:1/18:0, Cer d18:1/24:0, and Cer d18:1/24:1, designed for routine analysis.
  • Holm, Matilda; Joenväärä, Sakari; Saraswat, Mayank; Tohmola, Tiialotta; Ristimäki, Ari; Renkonen, Risto; Haglund, Caj (BioMed Central, 2019)
    Abstract Background Colorectal cancer (CRC) is the third most common cancer worldwide, and its incidence is expected to increase to over 2.2 million new cases in 2030. Stage II CRC is classified as localized disease, while stage III CRC has spread to regional lymph nodes. The 5-year survival rate is over 80% for patients with stage II CRC, but less than 60% for patients with stage III CRC. Proteins, especially plasma proteins that are detectable in easily obtained blood samples, that differ between stage II and III CRC could be useful for predicting and monitoring disease progression. CRC displays differences depending on primary tumor location (right colon, left colon, or rectum), and how plasma protein expression changes during CRC progression from stage II to III depending on primary tumor location is not well-characterized. Methods In this study, we have used Ultra Performance Liquid Chromatography-Ultra Definition Mass Spectrometry (UPLC-UDMSE)-based proteomics to analyze plasma samples from 83 patients with stage II or III CRC, followed by statistical and pathway analysis (data are available via ProteomeXchange). The patients were divided into groups according to tumor stage (II or III) and changes in plasma protein expression between stage II and III (localized and regional disease) samples were studied both regardless of primary tumor location and also within each primary tumor location (right colon, left colon, rectum). Results We discovered differences in plasma protein expression within all groups analyzed and identified proteins whose levels changed in one, two, or all three primary tumor locations between stage II and III CRC. Proteins were identified that could separate the groups compared and pathway analysis by IPA discovered altered pathways involved in lipid metabolism and inflammation, among others. Conclusions Plasma protein expression changes significantly as CRC progresses from stage II to III. While the levels of certain plasma proteins changed during cancer progression in only one or two primary tumor locations, the levels of 13 proteins changed in all primary tumor locations and are therefore common to CRC progression.
  • Batchu, Krishna Chaithanya; Hänninen, Satu; Jha, Sawan Kumar; Jeltsch, Michael; Somerharju, Pentti (2016)
    Cytosolic phospholipase A(2) alpha (cPLA(2)alpha) plays a key role in signaling in mammalian cells by releasing arachidonic acid (AA) from glycerophospholipids (GPLs) but the factors determining the specificity of cPLA(2)alpha for AA- containing GPLs are not well understood. Accordingly, we investigated those factors by determining the activity of human cPLA(2)alpha towards a multitude of GPL species present in micelles or bilayers. Studies on isomeric PC sets containing a saturated acyl chain of 6 to 24 carbons in the sn1 or sn2 position in micelles showed an abrupt decrease in hydrolysis when the length of the snl or sn2 chain exceeded 17 carbons suggesting that the acyl binding cavity on the enzyme is of the corresponding length. Notably, the saturated isomer pairs were hydrolyzed identically in micelles as well as in bilayers suggesting promiscuous binding of acyl chains to the active site of cPLA(2)alpha. Such promiscuous binding would explain the previous finding that cPLA(2)alpha has both PLA(1) and PLA(2) activities. Interestingly, increasing the length of either the sn1 or sn2 acyl chain inhibited the hydrolysis in bilayers far more than that in micelles suggesting that with micelles (loosely packed) substrate accommodation at the active site of cPLA(2)alpha is rate-limiting, while with bilayers (tightly packed) upward movement of the substrate from the bilayer (efflux) is the rate-limiting step. With the AA-containing PCs, the length of the saturated acyl chain also had a much stronger effect on hydrolysis in bilayers vs. micelles in agreement with this model. In contrast to saturated PCs, a marked isomer preference was observed for AA-containing PCs both in micelles and bilayers. In conclusion, these data significantly help to understand the mode of action and specificity of cPLA(2)alpha. (C) 2016 Elsevier B.V. All rights reserved.
  • Sulima, Anna; Bień, Justyna; Savijoki, Kirsi; Näreaho, Anu; Sałamatin, Rusłan; Conn, David B; Młocicki, Daniel (BioMed Central, 2017)
    Abstract Background A wide range of molecules are used by tapeworm metacestodes to establish successful infection in the hostile environment of the host. Reports indicating the proteins in the cestode-host interactions are limited predominantly to taeniids, with no previous data available for non-taeniid species. A non-taeniid, Hymenolepis diminuta, represents one of the most important model species in cestode biology and exhibits an exceptional developmental plasticity in its life-cycle, which involves two phylogenetically distant hosts, arthropod and vertebrate. Results We identified H. diminuta cysticercoid proteins that were recognized by sera of H. diminuta-infected rats using two-dimensional gel electrophoresis (2DE), 2D-immunoblotting, and LC-MS/MS mass spectrometry. Proteomic analysis of 42 antigenic spots revealed 70 proteins. The largest number belonged to structural proteins and to the heat-shock protein (HSP) family. These results show a number of the antigenic proteins of the cysticercoid stage, which were present already in the insect host prior to contact with the mammal host. These are the first parasite antigens that the mammal host encounters after the infection, therefore they may represent some of the molecules important in host-parasite interactions at the early stage of infection. Conclusions These results could help in understanding how H. diminuta and other cestodes adapt to their diverse and complex parasitic life-cycles and show universal molecules used among diverse groups of cestodes to escape the host response to infection.
  • Sulima, Anna; Bien, Justyna; Savijoki, Kirsi; Nareaho, Anu; Salamatin, Ruslan; Conn, David Bruce; Mlocicki, Daniel (2017)
    Background: A wide range of molecules are used by tapeworm metacestodes to establish successful infection in the hostile environment of the host. Reports indicating the proteins in the cestode-host interactions are limited predominantly to taeniids, with no previous data available for non-taeniid species. A non-taeniid, Hymenolepis diminuta, represents one of the most important model species in cestode biology and exhibits an exceptional developmental plasticity in its life-cycle, which involves two phylogenetically distant hosts, arthropod and vertebrate. Results: We identified H. diminuta cysticercoid proteins that were recognized by sera of H. diminuta-infected rats using two-dimensional gel electrophoresis (2DE), 2D-immunoblotting, and LC-MS/MS mass spectrometry. Proteomic analysis of 42 antigenic spots revealed 70 proteins. The largest number belonged to structural proteins and to the heat-shock protein (HSP) family. These results show a number of the antigenic proteins of the cysticercoid stage, which were present already in the insect host prior to contact with the mammal host. These are the first parasite antigens that the mammal host encounters after the infection, therefore they may represent some of the molecules important in host-parasite interactions at the early stage of infection. Conclusions: These results could help in understanding how H. diminuta and other cestodes adapt to their diverse and complex parasitic life-cycles and show universal molecules used among diverse groups of cestodes to escape the host response to infection.
  • Tähkä, Sari; Sarfraz, Jawad; Urvas, Lauri; Provenzani, Riccardo; Wiedmer, Susanne K.; Peltonen, Jouko; Jokinen, Ville; Sikanen, Tiina (2019)
    We introduce rapid replica molding of ordered, high-aspect-ratio, thiol-ene micropillar arrays for implementation of microfluidic immobilized enzyme reactors (IMERs). By exploiting the abundance of free surface thiols of off-stoichiometric thiol-ene compositions, we were able to functionalize the native thiol-ene micropillars with gold nanoparticles (GNPs) and these with proteolytic alpha-chymotrypsin (CHT) via thiol-gold interaction. The micropillar arrays were replicated via PDMS soft lithography, which facilitated thiol-ene curing without the photoinitiators, and thus straightforward bonding and good control over the surface chemistry (number of free surface thiols). The specificity of thiol-gold interaction was demonstrated over allyl-rich thiol-ene surfaces and the robustness of the CHT-IMERs at different flow rates and reaction temperatures using bradykinin hydrolysis as the model reaction. The product conversion rate was shown to increase as a function of decreasing flow rate (increasing residence time) and upon heating of the IMER to physiological temperature. Owing to the effective enzyme immobilization onto the micropillar array by GNPs, no further purification of the reaction solution was required prior to mass spectrometric detection of the bradykinin hydrolysis products and no clogging problems, commonly associated with conventional capillary packings, were observed. The activity of the IMER remained stable for at least 1.5 h (continuous use), suggesting that the developed protocol may provide a robust, new approach to implementation of IMER technology for proteomics research.
  • Parviainen, Ville I.; Joenväärä, Sakari; Tohmola, Niina; Renkonen, Risto (2013)
  • Hyotylainen, Tuulia; Ahonen, Linda; Pöhö, Paivi; Oresic, Matej (2017)
    Lipids have many central physiological roles including as structural components of cell membranes, energy storage sources and intermediates in signaling pathways. Lipid-related disturbances are known to underlie many diseases and their co-morbidities. The emergence of lipidomics has empowered researchers to study lipid metabolism at the cellular as well as physiological levels at a greater depth than was previously possible. The key challenges ahead in the field of lipidomics in medical research lie in the development of experimental protocols and in silico techniques needed to study lipidomes at the systems level. Clinical questions where lipidomics may have an impact in healthcare settings also need to be identified, both from the health outcomes and health economics perspectives. This article is part of a Special Issue entitled: BBALIP_Lipidomics Opinion Articles edited by Sepp Kohlwein.
  • 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.
  • Turunen, Soile; Puurunen, Jenni; Auriola, Seppo; Kullaa, Arja M.; Kärkkäinen, Olli; Lohi, Hannes; Hanhineva, Kati (2020)
    Introduction Saliva metabolites are suggested to reflect the health status of an individual in humans. The same could be true with the dog (Canis lupus familiaris), an important animal model of human disease, but its saliva metabolome is unknown. As a non-invasive sample, canine saliva could offer a new alternative material for research to reveal molecular mechanisms of different (patho)physiological stages, and for veterinary medicine to monitor dogs' health trajectories. Objectives To investigate and characterize the metabolite composition of dog and human saliva in a non-targeted manner. Methods Stimulated saliva was collected from 13 privately-owned dogs and from 14 human individuals. We used a non-targeted ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-qTOF-MS) method to measure metabolite profiles from saliva samples. Results We identified and classified a total of 211 endogenous and exogenous salivary metabolites. The compounds included amino acids, amino acid derivatives, biogenic amines, nucleic acid subunits, lipids, organic acids, small peptides as well as other metabolites, like metabolic waste molecules and other chemicals. Our results reveal a distinct metabolite profile of dog and human saliva as 25 lipid compounds were identified only in canine saliva and eight dipeptides only in human saliva. In addition, we observed large variation in ion abundance within and between the identified saliva metabolites in dog and human. Conclusion The results suggest that non-targeted metabolomics approach utilizing UHPLC-qTOF-MS can detect a wide range of small compounds in dog and human saliva with partially overlapping metabolite composition. The identified metabolites indicate that canine saliva is potentially a versatile material for the discovery of biomarkers for dog welfare. However, this profile is not complete, and dog saliva needs to be investigated in the future with other analytical platforms to characterize the whole canine saliva metabolome. Furthermore, the detailed comparison of human and dog saliva composition needs to be conducted with harmonized study design.
  • Lauren, Eva; Tigistu-Sahle, Feven; Valkonen, Sami; Westberg, Melissa; Valkeajarvi, Anne; Eronen, Juha; Siljander, Pia R-M; Pettila, Ville; Kakela, Reijo; Laitinen, Saara; Kerkela, Erja (2018)
    Red blood cells (RBCs) are stored up to 35-42 days at 2-6 degrees C in blood banks. During storage, the RBC membrane is challenged by energy depletion, decreasing pH, altered cation homeostasis, and oxidative stress, leading to several biochemical and morphological changes in RBCs and to shedding of extracellular vesicles (EVs) into the storage medium. These changes are collectively known as RBC storage lesions. EVs accumulate in stored RBC concentrates and are, thus, transfused into patients. The potency of EVs as bioactive effectors is largely acknowledged, and EVs in RBC concentrates are suspected to mediate some adverse effects of transfusion. Several studies have shown accumulation of lipid raft associated proteins in RBC EVs during storage, whereas a comprehensive phospholipidomic study on RBCs and corresponding EVs during the clinical storage period is lacking. Our mass spectrometric and chromatographic study shows that RBCs maintain their major phospholipid (PL) content well during storage despite abundant vesiculation. The phospholipidomes were largely similar between RBCs and EVs. No accumulation of raft lipids in EVs was seen, suggesting that the primary mechanism of RBC vesiculation during storage might not be raft-based. Nonetheless, a slight tendency of EV PLs for shorter acyl chains was observed.
  • McGlinchey, Aidan; Sinioja, Tim; Lamichhane, Santosh; Sen, Partho; Bodin, Johanna; Siljander, Heli; Dickens, Alex M.; Geng, Dawei; Carlsson, Cecilia; Duberg, Daniel; Ilonen, Jorma; Virtanen, Suvi M.; Dirven, Hubert; Berntsen, Hanne Friis; Zimmer, Karin; Nygaard, Unni C.; Oresic, Matej; Knip, Mikael; Hyötyläinen, Tuulia (2020)
    In the last decade, increasing incidence of type 1 diabetes (T1D) stabilized in Finland, a phenomenon that coincides with tighter regulation of perfluoroalkyl substances (PFAS). Here, we quantified PFAS to examine their effects, during pregnancy, on lipid and immune-related markers of T1D risk in children. In a mother-infant cohort (264 dyads), high PFAS exposure during pregnancy associated with decreased cord serum phospholipids and progression to T1D-associated islet autoantibodies in the offspring. This PFAS-lipid association appears exacerbated by increased human leukocyte antigen-conferred risk of T1D in infants. Exposure to a single PFAS compound or a mixture of organic pollutants in non-obese diabetic mice resulted in a lipid profile characterized by a similar decrease in phospholipids, a marked increase of lithocholic acid, and accelerated insulitis. Our findings suggest that PFAS exposure during pregnancy contributes to risk and pathogenesis of T1D in offspring.
  • Holm, Matilda; Joenväärä, Sakari; Saraswat, Mayank; Tohmola, Tiialotta; Ristimäki, Ari; Renkonen, Risto; Haglund, Caj (2020)
    Introduction:Colorectal cancer (CRC) is the third most common cancer worldwide, accounting for 10% of the global cancer burden. Rectal cancer accounts for around 30% of CRC cases, and patients with resectable rectal cancer are often given preoperative radiotherapy (PRT) to reduce the rate of local recurrence. The human plasma proteome is an exceptionally complex proteome and ideal to study due to its ability to reflect the presence of diseases such as cancer and the ease of obtaining blood samples. Previous proteomic studies involving rectal cancer patients have mostly focused on the identification of proteins involved in resistance to radiotherapy.Objective:The aim of this study was to investigate the overall effects of PRT on plasma protein expression in rectal cancer patients, as there is a lack of such studies.Methods:Here, we have used mass spectrometry and subsequent statistical analyses to analyze the plasma samples of 30 rectal cancer patients according to PRT status (positive or negative) and tumor stage (II or III).Results and Conclusions:We discovered 42 proteins whose levels differed significantly between stage II and III rectal cancer patients who did or did not receive PRT. This study shows that PRT, although localized to the pelvis, leads to measurable, tumor stage-specific changes in plasma protein expression. Future studies of plasma proteins should, when relevant, take this into account and be aware of the widespread effects that PRT has on the plasma proteome.
  • Nandania, Jatin; Kokkonen, Meri; Euro, Liliya; Velagapudi, Vidya (2018)
    The folate cycle is an essential metabolic pathway in the cell, involved in nucleotide synthesis, maintenance of the redox balance in the cell, methionine metabolism and re-methylation reactions. Standardised methods for the measurement of folate cycle intermediates in different biological matrices are in great demand. Here we describe a rapid, sensitive, precise and accurate liquid chromatographic-tandem mass spectrometric (LC-MS/ MS) method with a wide calibration curve range and a short run time for the simultaneous determination of folate cycle metabolites, including tetrahydrofolic acid (THF), 5-methyl THF, 5-formyl THF, 5,10-methenyl THF, 5,10-methylene THF, dihydrofolic acid (DHF) and folic acid in different biological matrices. Extraction of folate derivatives from soft and hard tissue samples as well as from adherent cells was achieved using homogenisation in buffer, while extraction from the whole blood and plasma relied on the anion exchange solid-phase extraction (SPE) method. Chromatographic separation was completed using a Waters Atlantis dC(18) 2.0 x 100 mm, 3-mu column with a gradient elution using formic acid in water (0.1% v/v) and acetonitrile as the mobile phases. LC gradient started with 95% of the aqueous phase which was gradually changed to 95% of the organic phase during 2.70 min in order to separate the selected metabolites. The analytes were separated with a run time of 5 min at a flow rate of 0.300 mL/min and detected using a Waters Xevo-TQS triple quadrupole mass spectrometer in the multiple reaction monitoring mode (MRM) at positive polarity. The instrument response was linear over a calibration range of 0.5 to 2500ng/mL (r(2) > 0.980). The developed bioanalytical method was thoroughly validated in terms of accuracy, precision, linearity, recovery, sensitivity and stability for tissue and blood samples. The matrix effect was compensated by using structurally similar isotope labelled internal standard (IS), C-13(5)-methyl THF, for all folate metabolites. However, not all folate metabolites can be accurately quantified using this method due to their high interconversion rates especially at low pH. This applies to 5,10-methylene THF which interconverts into THF, and 5,10-methenyl-THF interconverting into 5-formyl-THF. Using this method, we measured folate cycle intermediates in mouse bone marrow cells and plasma, in human whole blood; in mouse muscle, liver, heart and brain samples.
  • El Fellah, Samira; Duporte, Geoffroy; Siren, Heli (2017)
    Steroid hormones, botrydial, and inorganic ions were studied from cold and hot tap water samples with capillary electrophoresis techniques using UV detection. Identification of the steroids and botrydial was made with ultra-high -performance liquid chromatography (UHPLC) coupled to electrospray ionization orbitrap high-resolution mass spectrometry. Solid phase extraction with nonpolar and ion-exchange sorbents was needed to enrich the compounds for CE and UHPLC studies. The steroids identified from the drinking water samples were estradiol glucoside, androstenedione, testosterone, and progesterone. However, only progesterone could be quantified in both cold and hot tap water samples from Helsinki households. Its concentration varied from 0.031 ng/L to 0.135 ng/L and from 0.054 ng/L to 0.191 ng/L, respectively. Chloride and nitrate amounts were 25 mg/L. Calcium, potassium, magnesium, and sodium were 20, 1, 1, and 17 mg/L at the highest, respectively. Copper, iron, sulphate, and ammonium were below the methods concentration limits. Botrydial from Botrytis cinerea mould was identified in all drinking waters. In both cold and hot tap waters its concentration was 861-3900% higher than in a drilled well water that was also used as the household tap water. The mould was also confirmed by identification of its metabolite abscisic acid. (C) 2017 Elsevier B.V. All rights reserved.