Publications by authors named "Laura Kutzner"
Article Synopsis
- - This study focused on the bioavailability of omega-3 fatty acids, specifically comparing the effects of single doses of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on plasma levels in healthy men aged 20-40 with low fish consumption.
- - Twelve participants underwent a cross-over design, receiving either 2.2 g of EPA or 2.3 g of DHA, with blood samples collected at various intervals to track changes in plasma concentrations.
- - Results showed that EPA led to significantly higher plasma concentrations and a greater area under the concentration curve compared to DHA, indicating that EPA is more effective in raising plasma levels when administered in single doses.
Arachidonic acid 5-lipoxygenase (ALOX5) is the key enzyme in the biosynthesis of pro-inflammatory leukotrienes. We recently created knock-in mice (-KI) which express an arachidonic acid 15-lipoxygenating Alox5 mutant instead of the 5-lipoxygenating wildtype enzyme. These mice were leukotriene deficient but exhibited an elevated linoleic acid oxygenase activity.
View Article and Find Full Text PDFObjective: Cyclooxygenase (COX)-derived prostaglandin E (PGE) is an important lipid mediator in colorectal carcinoma (CRC) pathogenesis. Other lipid mediators derived from lipoxygenases (LOX) have also been implicated in neoplastic processes in the colon. In this study we aimed to characterize lipid mediators, so called oxylipins, in human colon adenomatous polyps.
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- * In a study with mice, diets were analyzed based on their n6-PUFA content, with one group receiving low n6 and another high n6, both supplemented with low or higher amounts of n3-PUFA like EPA or DHA.
- * Results showed that combining n3-PUFA supplementation with a low n6 diet effectively improved n3-PUFA levels in tissues and blood, while the n6-low diet alone had minimal impact on arachidonic acid levels. *
Human lipoxygenase isoforms form complex patterns of double and triple oxygenated compounds from eicosapentaenoic acid.
Biochim Biophys Acta Mol Cell Biol Lipids
December 2020
Article Synopsis
- Lipoxygenases (ALOX) are enzymes that help create lipid mediators involved in inflammation and have implications for various physiological processes in humans.
- The study focused on the oxygenation products formed by different human ALOX isoforms when reacting with eicosapentaenoic acid (EPA) and its derivative, revealing a spectrum of bioactive compounds.
- Key findings included that ALOX15 and ALOX5 generate a variety of double oxygenation products, while ALOX5 is essential for forming complex triple oxygenation products, indicating the potential for these compounds to be biologically active.
Article Synopsis
- - Oxidized unsaturated fatty acids, known as eicosanoids and oxylipins, play a key role in various bodily functions including inflammation and blood flow regulation, and are of great interest in clinical lipidomics for their potential as health biomarkers.
- - This study used liquid chromatography-mass spectrometry to analyze 133 oxylipins in plasma samples, focusing on how sample handling and storage conditions affected their stability and concentration.
- - Findings showed that adding a radical scavenger improved sample reliability, and while oxylipin levels remained stable under certain conditions, longer storage times led to changes indicating residual enzyme activity, emphasizing the need for careful sample processing.
Long-term stimulation of toll-like receptor-2 and -4 upregulates 5-LO and 15-LO-2 expression thereby inducing a lipid mediator shift in human monocyte-derived macrophages.
Biochim Biophys Acta Mol Cell Biol Lipids
September 2020
Article Synopsis
- Macrophages can change their function (polarization) during inflammation, influenced by lipid signals released from cells.
- The study examined how human macrophages, derived from blood monocytes, develop into either M1 or M2 types under specific conditions and respond to various pathogen stimuli.
- Results indicated that M1 macrophages primarily produce pro-inflammatory signals, while sustained stimulation of M2 macrophages leads to the production of anti-inflammatory and pro-resolving lipid mediators, indicating a shift in their activity.
Targeting esterified oxylipins by LC-MS - Effect of sample preparation on oxylipin pattern.
Prostaglandins Other Lipid Mediat
February 2020
Article Synopsis
- A significant portion of oxygenated metabolites from polyunsaturated fatty acids, like eicosanoids, are found in esterified forms, but their biological functions are not fully understood.
- Current methods for measuring these esterified oxylipins involve breaking them down into free forms using alkaline hydrolysis, often with lipid extraction, followed by quantification through liquid chromatography-mass spectrometry.
- A detailed protocol for accurately measuring esterified oxylipins in plasma includes lipid extraction, base hydrolysis, and solid phase extraction, with careful attention to solvent choice and hydrolysis conditions to ensure reliable results.
Article Synopsis
- Arachidonate lipoxygenase (ALOX) isoforms are key in producing inflammatory leukotrienes and pro-resolving mediators, but the specific effects of certain mutations in ALOX5 are not well understood.
- Researchers created knock-in mice with a specific triple mutation in the Alox5 gene to study the biological consequences of these alterations, demonstrating that the mutant enzyme favors the production of a beneficial compound called 13S-hydroxy linoleic acid (13S-HODE) instead of proinflammatory leukotrienes.
- The mutant mice are healthy and fertile but exhibit increased body weight as they age, potentially linked to elevated levels of 13-HODE in their fat tissue, indicating how these genetic
Article Synopsis
- The study investigates the effects of echium oil (EO) on the metabolism of omega-3 polyunsaturated fatty acids (PUFAs), specifically examining the changes in plasma levels after ingestion.
- After healthy young male subjects consumed 26 grams of EO, there were significant increases in plasma concentrations of alpha-linolenic acid (ALA), stearidonic acid (SDA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA3), and docosahexaenoic acid (DHA) over 72 hours.
- The findings suggest that echium oil could be a viable alternative source of omega-3 fatty acids, potentially offering health benefits comparable to those derived
Article Synopsis
- - The study explores how long-chain omega-3 fatty acids (n3 PUFA) can help protect the heart and fight inflammation through their metabolites, especially specialized pro-resolving mediators (SPMs).
- - A new LC-MS/MS method was developed to accurately measure 18 types of SPMs derived from key fatty acids, with careful attention to calibration and validation according to quality standards.
- - The results show that SPM levels are generally very low in healthy individuals (<0.1 nM), but they may increase following conditions like septic shock or peritonitis.
Lipoprotein apheresis reliably reduces low-density lipoprotein (LDL) cholesterol in patients with atherosclerotic disease and therapy-refractory hypercholesterolemia or elevated lipoprotein (a) (Lp(a)). Besides lowering lipoproteins and triglycerides, apheresis also decreases levels of essential omega-6 and omega-3 polyunsaturated fatty acids (6 and 3 PUFAs) in blood plasma. In contrast, heparin-induced extracorporeal low-density lipoprotein precipitation (HELP) lipid apheresis might increase the formation of potentially pro-inflammatory and pro-thrombotic lipid mediators derived from 6 and 3 PUFAs.
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- Misregulation of oxidative stress, linked to various diseases like inflammatory and neurodegenerative disorders, results in the formation of isoprostanes (IsoP) and isofurans (IsoF) from polyunsaturated fatty acids (PUFA), which can serve as biomarkers and lipid mediators.
- A new LC-ESI(-)-MS/MS method enables the simultaneous quantification of 27 IsoP and 8 IsoF derived from six different types of PUFA in just 12 minutes, demonstrating high sensitivity and precision in detecting them in biological samples.
- This comprehensive method has been validated using human plasma and shows distinctive patterns of IsoP and IsoF in response to oxidative stress, contributing valuable insights into targeted metabol
Article Synopsis
- A debate exists on the best dietary balance between the n6 fatty acid linoleic acid (LA) and the n3 fatty acid alpha-linolenic acid (ALA) for converting ALA to beneficial EPA and DHA, which are important for human health.
- In a study involving 15 healthy men, researchers compared the effects of a low-LA/high-ALA diet to a high-LA/low-ALA diet and measured fatty acid levels in red blood cells over two weeks.
- Results showed that the low-LA/high-ALA diet increased ALA and EPA levels while decreasing LA levels, indicating that a lower LA intake better enhances EPA concentrations compared to a high-LA diet, which showed minimal changes.
Article Synopsis
- - The study investigated how a high-ALA (alpha-linolenic acid) diet affects EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) levels in red blood cells of young men with initially low levels of these fatty acids.
- - After 12 weeks on a diet providing 14 g of ALA daily, ALA levels in the blood significantly increased, and EPA levels also rose, while unexpectedly, DHA levels decreased over time.
- - The findings suggest that although ALA intake increases certain fatty acids and their metabolites, it is not sufficient to elevate overall EPA and DHA levels in the blood effectively.
Article Synopsis
- Eicosanoids, like prostaglandins and thromboxanes, are lipids that may promote colon cancer through inflammation, while acetylsalicylic acid (ASA) is linked to a reduced risk of colorectal cancer (CRC) by inhibiting these lipids.
- A study showed that patients on ASA had significantly lower levels of certain eicosanoids in their colon tissue compared to those not on the drug, suggesting ASA's effectiveness in altering lipid profiles.
- Interestingly, statin users had higher levels of these eicosanoids, but those taking both ASA and statins exhibited even greater suppression of eicosanoids, indicating potential combined benefits that warrant further investigation for CRC prevention.
A diet rich in omega-3 fatty acids enhances expression of soluble epoxide hydrolase in murine brain.
Prostaglandins Other Lipid Mediat
November 2017
Article Synopsis
- - Several studies indicate that omega-3 polyunsaturated fatty acids (n3-PUFA) could improve cognitive function, but the exact effects on the adult brain are still unclear.
- - In an experiment with mice, supplementation with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for 30 days led to noticeable changes in the fatty acid composition in the brain, increasing certain n3-PUFAs and decreasing many n6-PUFAs.
- - The study also found significant changes in the levels of oxidative metabolites and enzymes related to fatty acid metabolism, suggesting that n3-PUFA supplementation may influence brain function and potentially have implications for neurodegenerative diseases.
Mammalian ALOX15 orthologs exhibit pronounced dual positional specificity with docosahexaenoic acid.
Biochim Biophys Acta Mol Cell Biol Lipids
July 2017
Article Synopsis
- Mammalian lipoxygenases (LOX) play a significant role in cell differentiation and diseases related to inflammation and neurobiology, yet their functionality with n-3 fatty acids like EPA and DHA is not well understood.
- Researchers characterized the ALOX15 orthologs from eight mammalian species, alongside human ALOX12 and ALOX15B, to analyze their specificity with key polyunsaturated fatty acids (PUFAs).
- The study found that LOX isoforms can modify n-3 fatty acids with varied specificity, often showing a preference for DHA and EPA over arachidonic acid, suggesting more complex interactions than previously thought.
Article Synopsis
- The study analyzes the fatty acid composition of dietary supplements containing n-3 polyunsaturated fatty acids (PUFA) from marine sources to provide more detailed information than typically available from manufacturers.
- Twelve products, including fish oil, krill oil, algal oil, and plant oil, were examined, revealing varying total n-3 PUFA content, with fish oil having the highest at 68 g/100 g fat.
- The analysis categorized these products based on their lipid types (like ethyl esters and triglycerides), finding significant differences in lipid patterns even among similar products, suggesting a need for clearer specifications in n-3 PUFA supplement labeling.
Effects of docosahexaenoic acid supplementation on PUFA levels in red blood cells and plasma.
Prostaglandins Leukot Essent Fatty Acids
December 2016
Article Synopsis
- Polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA), are metabolized through processes like elongation and oxidation, which affect their concentrations in the body.
- A study on 12 healthy men revealed that DHA supplementation (1076 mg/d) significantly increased its levels in red blood cells and led to a notable decrease in arachidonic acid (AA) concentrations, especially in plasma.
- The results also indicated that DHA boosts eicosapentaenoic acid (EPA) levels, suggesting that DHA might convert to EPA, although the effects on EPA-derived lipid mediators remain unclear.