| 1. |
- Björkgren, Ida, et al.
(författare)
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Imbalanced lipid homeostasis in the conditional Dicer1 knockout mouse epididymis causes instability of the sperm membrane.
- 2015
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Ingår i: FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - : Wiley. - 1530-6860. ; 29:2, s. 433-442
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Tidskriftsartikel (refereegranskat)abstract
- During epididymal sperm maturation, the lipid content of the sperm membrane is modified, which facilitates sperm motility and fertility. However, little is known about the mechanisms regulating the maturation process. By generating a conditional knockout (cKO) of Dicer1 in the proximal part of the mouse epididymis, we studied the role of RNA interference in epididymal functions. The Dicer1 cKO epididymis displayed an altered lipid homeostasis associated with a 0.6-fold reduction in the expression of the gene elongation of very long chain fatty acids-like 2, an enzyme needed for production of long-chain polyunsaturated fatty acids (PUFAs). Furthermore, the expression of several factors involved in cholesterol synthesis was up-regulated. Accordingly, the Dicer1 cKO sperm membrane showed a 0.7-fold decrease in long-chain PUFAs, whereas the amount of cholesterol in acrosome-reacted sperm displayed a 1.7-fold increase. The increased cholesterol:PUFA ratio of the sperm membrane caused breakage of the neck and acrosome region and immotility of sperm. Dicer1 cKO mice sperm also displayed reduced ability to bind to and fertilize the oocyte in vitro. This study thus shows that Dicer1 is critical for lipid synthesis in the epididymis, which directly affects sperm membrane integrity and male fertility.-Björkgren, I., Gylling, H., Turunen, H., Huhtaniemi, I., Strauss, L., Poutanen, M., Sipilä, P. Imbalanced lipid homeostasis in the conditional Dicer1 knockout mouse epididymis causes instability of the sperm membrane.
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| 2. |
- Joukamo, Laura, et al.
(författare)
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Rasvainen kala muokkaa HDL-hiukkaskokoa ja lipidipitoisuuksia [Fatty fish modifies HDL particle size and lipid concentrations]
- 2013
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Ingår i: Duodecim. - : Duodecim. - 0012-7183 .- 2242-3281. ; 129:24, s. 2661-2670
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: We investigated with 1HNMR-spectroscopy the effects of habitual fatty fish intake on serum lipiprotein profiles in persons with features of metabolic syndrome.MATERIAL AND METHODS: The participants (n = 105) were randomized into three diet intervention groups. The groups were given different dietary instructions.RESULTS: Increased intake of fatty fish had a significant (p < 0.05) increasing effect on the amount of large HDL-lipoprotein subclasses and their lipids.CONCLUSIONS: Frequent intake of fatty fish may have beneficial effects on HDL-metabolism beyond that assumed to be related to its serum concentrations.
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| 3. |
- Karpale, Mikko, et al.
(författare)
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Activation of nuclear receptor PXR induces atherogenic lipids and PCSK9 through SREBP2-mediated mechanism
- 2021
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Ingår i: British Journal of Pharmacology. - : Macmillan Publishers Ltd.. - 0007-1188 .- 1476-5381. ; 178:12, s. 2461-2481
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Many drugs and environmental contaminants induce hypercholesterolemia and promote the risk of atherosclerotic cardiovascular disease. The mechanisms involved are poorly defined precluding efficient prediction and prevention. We tested the hypothesis that pregnane X receptor (PXR), a xenobiotic-sensing nuclear receptor, regulates the level of circulating atherogenic lipids in humans and utilized mouse experiments to identify the mechanisms involved.EXPERIMENTAL APPROACH: We performed serum NMR metabolomics in healthy volunteers administered rifampicin, a prototypical human PXR ligand, or placebo in a crossover setting. Furthermore, we used high-fat diet fed wildtype and PXR knockout mice to investigate the mechanisms and pathways mediating the PXR-induced alterations in cholesterol homeostasis.KEY RESULTS: Activation of PXR induced cholesterogenesis both in pre-clinical and clinical settings. In human volunteers, rifampicin increased IDL, LDL and total cholesterol and lathosterol-cholesterol ratio, a marker of cholesterol synthesis, suggesting increased cholesterol synthesis. Mechanistic studies in mice indicated that PXR activation launches widespread induction of the cholesterol synthesis genes including the rate-limiting Hmgcr and upregulates the intermediates in the Kandutsch-Russell cholesterol synthesis pathway in the liver. Additionally, PXR activation induced plasma PCSK9, a negative regulator of hepatic LDL uptake, in both mice and humans. We propose that these effects were mediated through increased proteolytic activation of SREBP2 in response to PXR activation.CONCLUSION AND IMPLICATIONS: PXR activation induces cholesterol synthesis and elevates LDL and total cholesterol in humans. The PXR-SREBP2 pathway is a novel regulator of the cholesterol and PCSK9 synthesis, and a molecular mechanism for drug- and chemical-induced hypercholesterolemia.
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| 4. |
- Lankinen, Maria A., et al.
(författare)
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Dietary carbohydrate modification alters serum metabolic profiles in individuals with the metabolic syndrome
- 2010
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Ingår i: NMCD. Nutrition Metabolism and Cardiovascular Diseases. - : Elsevier. - 0939-4753 .- 1590-3729. ; 20:4, s. 249-57
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: Whole-grain cereals and diets with a low glycemic index may protect against the development of type 2 diabetes and heart disease, but the mechanisms are poorly understood. We studied the effect of carbohydrate modification on serum metabolic profiles, including lipids and branched chain amino acids, and dependencies between these and specific gene expression pathways in adipose tissue.METHODS AND RESULTS: Twenty subjects with metabolic syndrome were selected from the larger FUNGENUT study population, randomized either to a diet high in oat and wheat bread and potato (OWP) or rye bread and pasta (RP). Serum metabolomics analyses were performed using ultra-performance liquid chromatography coupled to electrospray ionization mass spectrometry (UPLC/MS), gas chromatography (GC) and UPLC. In the OWP group multiple proinflammatory lysophosphatidylcholines increased, while in the RP group docosahexaenoic acid (DHA 22:6n-3) increased and isoleucine decreased. mRNA expression of stress reactions- and adipose tissue differentiation-related genes were up-regulated in adipose tissue in the OWP group. In the RP group, however, pathways related to stress reactions and insulin signaling and energy metabolism were down-regulated. The lipid profiles had the strongest association with the changes in the adipose tissue differentiation pathway when using the elastic net regression model of the lipidomic profiles on selected pathways.CONCLUSION: Our results suggest that the dietary carbohydrate modification alters the serum metabolic profile, especially in lysoPC species, and may, thus, contribute to proinflammatory processes which in turn promote adverse changes in insulin and glucose metabolism.
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| 5. |
- Lankinen, Maria, et al.
(författare)
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Effects of whole grain, fish and bilberries on serum metabolic profile and lipid transfer protein activities : a randomized trial (Sysdimet)
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We studied the combined effects of wholegrain, fish and bilberries on serum metabolic profile and lipid transfer protein activities in subjects with the metabolic syndrome.METHODS: Altogether 131 subjects (40-70 y, BMI 26-39 kg/m(2)) with impaired glucose metabolism and features of the metabolic syndrome were randomized into three groups with 12-week periods according to a parallel study design. They consumed either: a) wholegrain and low postprandial insulin response grain products, fatty fish 3 times a week, and bilberries 3 portions per day (HealthyDiet), b) wholegrain and low postprandial insulin response grain products (WGED), or c) refined wheat breads as cereal products (Control). Altogether 106 subjects completed the study. Serum metabolic profile was studied using an NMR-based platform providing information on lipoprotein subclasses and lipids as well as low-molecular-weight metabolites.RESULTS: There were no significant differences in clinical characteristics between the groups at baseline or at the end of the intervention. Mixed model analyses revealed significant changes in lipid metabolites in the HealthyDiet group during the intervention compared to the Control group. All changes reflected increased polyunsaturation in plasma fatty acids, especially in n-3 PUFAs, while n-6 and n-7 fatty acids decreased. According to tertiles of changes in fish intake, a greater increase of fish intake was associated with increased concentration of large HDL particles, larger average diameter of HDL particles, and increased concentrations of large HDL lipid components, even though total levels of HDL cholesterol remained stable.CONCLUSIONS: The results suggest that consumption of diet rich in whole grain, bilberries and especially fatty fish causes changes in HDL particles shifting their subclass distribution toward larger particles. These changes may be related to known protective functions of HDL such as reverse cholesterol transport and could partly explain the known protective effects of fish consumption against atherosclerosis.TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov NCT00573781.
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| 6. |
- Lankinen, Maria, et al.
(författare)
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Fatty fish intake decreases lipids related to inflammation and insulin signaling : a lipidomics approach
- 2009
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Ingår i: PLOS ONE. - : PLOS. - 1932-6203. ; 4:4
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The evidence of the multiple beneficial health effects of fish consumption is strong, but physiological mechanisms behind these effects are not completely known. Little information is available on the effects of consumption of different type of fish. The aim of this study was to investigate how fatty fish or lean fish in a diet affect serum lipidomic profiles in subjects with coronary heart disease.METHODOLOGY AND PRINCIPAL FINDINGS: A pilot study was designed which included altogether 33 subjects with myocardial infarction or unstable ischemic attack in an 8-week parallel controlled intervention. The subjects were randomized to either fatty fish (n = 11), lean fish (n = 12) or control (n = 10) groups. Subjects in the fish groups had 4 fish meals per week and subjects in the control group consumed lean beef, pork and chicken. A fish meal was allowed once a week maximum. Lipidomics analyses were performed using ultra performance liquid chromatography coupled to electrospray ionization mass spectrometry and gas chromatography. Multiple bioactive lipid species, including ceramides, lysophosphatidylcholines and diacylglycerols, decreased significantly in the fatty fish group, whereas in the lean fish group cholesterol esters and specific long-chain triacylglycerols increased significantly (False Discovery Rate q-value <0.05).CONCLUSIONS/SIGNIFICANCE: The 8-week consumption of fatty fish decreased lipids which are potential mediators of lipid-induced insulin resistance and inflammation, and may be related to the protective effects of fatty fish on the progression of atherosclerotic vascular diseases or insulin resistance.TRIAL REGISTRATION: ClinicalTrials.gov NCT00720655.
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| 7. |
- Lankinen, Maria, et al.
(författare)
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Metabolomic analysis of plasma metabolites that may mediate effects of rye bread on satiety and weight maintenance in postmenopausal women
- 2011
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Ingår i: Journal of Nutrition. - : Oxford University Press. - 0022-3166 .- 1541-6100. ; 141:1, s. 31-36
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Tidskriftsartikel (refereegranskat)abstract
- The evidence of the beneficial health effects of dietary fiber and whole grain consumption is strong, but the underlying mechanisms are not completely understood. Here, we investigate how the consumption of high-fiber rye bread (RB) or white-wheat bread (WB) modifies the plasma metabolomic profiles in postmenopausal women. The study was a randomized crossover trial consisting of 8-wk intervention periods and an 8-wk washout period. The study included 39 postmenopausal women with elevated serum total cholesterol (5.0-8.5 mmol/L) and BMI 20-33 kg/m(2). During the intervention periods, the study breads contributed to least 20% of total energy intake. Two analytical platforms for metabolomics were applied. Lipidomic analysis was performed using ultra performance liquid chromatography coupled to electrospray ionization MS and the other metabolites, including sterols, organic acids, and alcohols, were analyzed by 2-dimensional GC coupled to time-of-flight MS. Altogether, 540 metabolites were profiled. Ribitol (P < 0.001), ribonic acid (P < 0.001), and indoleacetic acid (P < 0.001) increased during the RB consumption period. Ribonic acid correlated positively with tryptophan (r = 0.40; P = 0.003), which is a precursor for the biosynthesis of hunger-depressing serotonin. There were no changes in plasma lipidomic profiles during the RB or WB intervention periods. The results suggest that 8-wk consumption of high-fiber rye bread increases metabolites that might mediate positive effects of rye bread on satiety and weight maintenance.
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| 8. |
- Lankinen, Maria, et al.
(författare)
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Whole grain products, fish and bilberries alter glucose and lipid metabolism in a randomized, controlled trial : the Sysdimet study
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 6:8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Due to the growing prevalence of type 2 diabetes, new dietary solutions are needed to help improve glucose and lipid metabolism in persons at high risk of developing the disease. Herein we investigated the effects of low-insulin-response grain products, fatty fish, and berries on glucose metabolism and plasma lipidomic profiles in persons with impaired glucose metabolism.METHODOLOGY/PRINCIPAL FINDINGS: Altogether 106 men and women with impaired glucose metabolism and with at least two other features of the metabolic syndrome were included in a 12-week parallel dietary intervention. The participants were randomized into three diet intervention groups: (1) whole grain and low postprandial insulin response grain products, fatty fish three times a week, and bilberries three portions per day (HealthyDiet group), (2) Whole grain enriched diet (WGED) group, which includes principally the same grain products as group (1), but with no change in fish or berry consumption, and (3) refined wheat breads (Control). Oral glucose tolerance, plasma fatty acids and lipidomic profiles were measured before and after the intervention. Self-reported compliance with the diets was good and the body weight remained constant. Within the HealthyDiet group two hour glucose concentration and area-under-the-curve for glucose decreased and plasma proportion of (n-3) long-chain PUFAs increased (False Discovery Rate p-values <0.05). Increases in eicosapentaenoic acid and docosahexaenoic acid associated curvilinearly with the improved insulin secretion and glucose disposal. Among the 364 characterized lipids, 25 changed significantly in the HealthyDiet group, including multiple triglycerides incorporating the long chain (n-3) PUFA.CONCLUSIONS/SIGNIFICANCE: The results suggest that the diet rich in whole grain and low insulin response grain products, bilberries, and fatty fish improve glucose metabolism and alter the lipidomic profile. Therefore, such a diet may have a beneficial effect in the efforts to prevent type 2 diabetes in high risk persons.TRIAL REGISTRATION: ClinicalTrials.gov NCT00573781.
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| 9. |
- Luukkonen, Panu K., et al.
(författare)
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Saturated fat is more metabolically harmful for the human liver than unsaturated fat or simple sugars
- 2018
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Ingår i: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 41:8, s. 1732-1739
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Nonalcoholic fatty liver disease (i.e., increased intrahepatic triglyceride [IHTG] content), predisposes to type 2 diabetes and cardiovascular disease. Adipose tissue lipolysis and hepatic de novo lipogenesis (DNL) are the main pathways contributing to IHTG. We hypothesized that dietary macronutrient composition influences the pathways, mediators, and magnitude of weight gain-induced changes in IHTG. RESEARCH DESIGN AND METHODS: We overfed 38 overweight subjects (age 48 ± 2 years, BMI 31 ± 1 kg/m2, liver fat 4.7 ± 0.9%) 1,000 extra kcal/day of saturated (SAT) or unsaturated (UNSAT) fat or simple sugars (CARB) for 3 weeks. We measured IHTG (1H-MRS), pathways contributing to IHTG (lipolysis ([2H5]glycerol) and DNL (2H2O) basally and during euglycemic hyperinsulinemia), insulin resistance, endotoxemia, plasma ceramides, and adipose tissue gene expression at 0 and 3 weeks. RESULTS: Overfeeding SAT increased IHTG more (+55%) than UNSAT (+15%, P < 0.05). CARB increased IHTG (+33%) by stimulating DNL (+98%). SAT significantly increased while UNSAT decreased lipolysis. SAT induced insulin resistance and endotoxemia and significantly increased multiple plasma ceramides. The diets had distinct effects on adipose tissue gene expression. CONCLUSIONS: Macronutrient composition of excess energy influences pathways of IHTG: CARB increases DNL, while SAT increases and UNSAT decreases lipolysis. SAT induced the greatest increase in IHTG, insulin resistance, and harmful ceramides. Decreased intakes of SAT could be beneficial in reducing IHTG and the associated risk of diabetes. © 2018 by the American Diabetes Association.
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| 10. |
- Schwab, Ursula, et al.
(författare)
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Triacylglycerol fatty acid composition in diet-induced weight loss in subjects with abnormal glucose metabolism : the GENOBIN study
- 2008
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Ingår i: PLOS ONE. - : PLOS. - 1932-6203. ; 3:7
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The effect of weight loss on different plasma lipid subclasses at the molecular level is unknown. The aim of this study was to examine whether a diet-induced weight reduction result in changes in the extended plasma lipid profiles (lipidome) in subjects with features of metabolic syndrome in a 33-week intervention.METHODOLOGY/PRINCIPAL FINDINGS: Plasma samples of 9 subjects in the weight reduction group and 10 subjects in the control group were analyzed using mass spectrometry based lipidomic and fatty acid analyses. Body weight decreased in the weight reduction group by 7.8+/-2.9% (p<0.01). Most of the serum triacylglycerols and phosphatidylcholines were reduced. The decrease in triacylglycerols affected predominantly the saturated short chain fatty acids. This decrease of saturated short chain fatty acid containing triacylglycerols correlated with the increase of insulin sensitivity. However, levels of several longer chain fatty acids, including arachidonic and docosahexanoic acid, were not affected by weight loss. Levels of other lipids known to be associated with obesity such as sphingolipids and lysophosphatidylcholines were not altered by weight reduction.CONCLUSIONS/SIGNIFICANCE: Diet-induced weight loss caused significant changes in global lipid profiles in subjects with abnormal glucose metabolism. The observed changes may affect insulin sensitivity and glucose metabolism in these subjects.TRIAL REGISTRATION: ClinicalTrials.gov NCT00621205.
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