| 1. |
- Ramamoorthy, Sunil Kumar, et al.
(författare)
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Biocomposites From Regenerated Cellulose Textile Fibers And Bio-Based Thermoset Matrix For Automotive Applications
- 2013
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Konferensbidrag (refereegranskat)abstract
- Biocomposites were produced from regenerated cellulose fiber reinforcement and soybean based bio-matrix. Mechanical, thermal, viscoelastic and morphological results show the good potential of these composites to be used as structural materials in automotive industries. This article focuses on manufacturing and testing of these composites for engineering materials. Regenerated cellulose fibers such as Lyocell and viscose were reinforced in soybean based thermoset matrix to produce composites by compression molding. Hybrid composites were produced by mixing both these fibers at known ratio and the total fiber content in composite was between 40 and 60 weight %. In general, Lyocell based composites showed better tensile properties than viscose based composites. Composites consisting 60 weight % Lyocell and rest with matrix had tensile strength of 135 MPa and tensile modulus of 17 GPa. These composites also showed good flexural properties; flexural strength of 127 Mpa and flexural modulus of 7 GPa. Dynamic mechanical thermal analysis showed that these composites had good viscoelastic properties. Viscose based composites had better percentage elongation during tensile test. These composites also showed relatively good impact and viscoelastic properties. Scanning electron microscope images showed that the composites had good fiber-matrix adhesion. Several efforts are made to produce sustainable biomaterials to replace synthetic materials due to inherent properties like renewable, biodegradable and low density. Biocomposites play significant role in sustainable materials which has already found applications in automotive and construction industries. Many researchers produced biocomposites from natural fiber and bio-based/synthetic matrix and it had found several applications. There are several disadvantages of using natural fiber in composites; quality variation, place dependent, plant maturity, harvesting method, high water absorption etc. These composites also give odor which has to be avoided in indoor automotive applications. These natural fibers can be replaced with lignocelluloses, agro mass and biomass to develop biocomposites as they are from natural origin. Lyocell and viscose are manmade regenerated cellulose fibers which is from natural origin has excellent properties. These fibers can be used as reinforcements to produce biocomposites which can overcome most of the above listed disadvantages of natural fibers. Many composites were made from natural fiber reinforcement and petroleum based synthetic matrix. Researchers have been finding ways to get matrix out of natural resources like soybean and linseed on chemical modifications. This article is focused on producing and testing sustainable material with regenerated cellulose and soybean based bio-matrix for automotive applications.
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| 2. |
- Ramamoorthy, Sunil Kumar, et al.
(författare)
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Characterization Of Wood Based Fiber Reinforced Bio-Composites
- 2013
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Konferensbidrag (refereegranskat)abstract
- Natural fiber composites have got more focus in recent times due to their intrinsic properties such as lightweight, biodegradable, low cost etc. Several researchers have made bio-composites out of many natural fibers such as jute, flax, sisal. These composites have large market in Europe and North America where it is used in automobile and construction industry. A lot of research has been done to improve the properties such as surface modification of fiber, manufacturing hybrid composites. However, the natural fibers are dissimilar and vary largely due to many factors such as variety, harvest, maturity, climate etc. Apart from technical drawbacks, these fibers grow only in certain countries such as India and China. High demand raised the price of these fibers which increases the product price as well. Wood-based fibers such as Lyocell and Viscose was used to make composites in order to make less variation in products, decrease the dependency of natural fibers, promoting locally available fibers and encourage forest products as value-added products. Lyocell and viscose fibers have relatively less variation and high quality. Bio-composites were made by reinforcing wood-based fibers in soybean based thermoset matrix. Hybrid composites were prepared by mixing two different wood-based fibers in known ratio. The fiber content in the composites was between 40 and 60 weight%. Mechanical properties were characterized by tensile, flexural and impact tests. Lyocell and viscose based composites had better mechanical properties than jute fiber composites. Alkali treatment of Lyocell fibers improved the mechanical properties of the composites. The behaviour of wood-based fiber composites were studied under wet environment as well. In wet environment, the mechanical properties of wood-based fiber composites were superior to jute fiber composites. Lyocell based composites had tensile strength of 135 MPa and tensile modulus of 17 GPa. The composites had flexural strength of 127 MPa and flexural modulus of 7 GPa. Better percentage elongation was obtained when viscose fiber was reinforced in matrix. Viscose composites had better impact strength and viscoelastic properties. The change in properties in two different wood-based fibers (Lyocell and viscose) lies in the morphology of the fiber itself. Hybrid composites were produced and the effect of hybridization was clear in most of the cases. The properties were able to be tailored by making hybrid composites, by changing the amount of each fiber in the composites. The results (tensile and flexural) were competitive and fulfil the requirements of these composites to be used in several applications including automotive headliners, car door panel, construction door frame etc. The forest products such as wood fibers could be used in composites to produce environmentally friendly products and promote forest industry. Wood-based fibers such as Lyocell and Viscose was used to make composites in order to make less variation in products, decrease the dependency of natural fibers, promoting locally available fibers and encourage forest products. Bio-composites were made by reinforcing wood-based fibers in soybean based thermoset matrix. Hybrid composites were prepared by mixing two different wood-based fibers in known ratio. Mechanical properties were characterized by tensile, flexural and impact tests. Lyocell and viscose based composites had better mechanical properties than jute fiber composites. Alkali treatment of Lyocell fibers improved the mechanical properties of the composites. The behaviour of wood-based fiber composites were studied under wet environment as well. In wet environment, the mechanical properties of wood-based fiber composites were superior to jute fiber composites. Lyocell based composites had tensile strength of 135 MPa and tensile modulus of 17 GPa. The composites had flexural strength of 127 MPa and flexural modulus of 7 GPa. Viscose composites had better impact strength and viscoelastic properties. The result fulfils the requirements of these composites to be used in several applications including automotive headliners, car door panel etc. The forest products could be used in composites to produce environmentally friendly products and promote forest industry.
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| 3. |
- Ramamoorthy, Sunil Kumar, et al.
(författare)
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Green Composites Based On Regenerated Cellulose Textile Fibers For Structural Composites
- 2013
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Konferensbidrag (refereegranskat)abstract
- Composites were manufactured from regenerated cellulose and biobased matrix by compression molding. The reinforcing materials used were Lyocell and viscose, while the matrix used was chemically modified soybean oil. Hybrid composites were prepared by mixing both the fibers. The total fiber content in the composites was between 40-60 weight %. Lyocell based composites had better tensile properties than viscose based composites; composites consisting 60 weight % Lyocell impregnated with matrix had tensile strength of 135 MPa and tensile modulus of 17 GPa. These composites also showed better flexural properties; flexural strength of 127 MPa and flexural modulus of 7 GPa. Dynamic mechanical thermal analysis results showed that these composites had good viscoelastic properties. Viscose based composites had better percentage elongation; these composites also showed relatively good impact and viscoelastic properties. Hybrid composites showed good mechanical and viscoelastic properties. Scanning electron microscope images showed that the composites had good fiber-matrix adhesion.
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| 4. |
- Ramamoorthy, Sunil Kumar, et al.
(författare)
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Properties of green composites with regenerated cellulose fiber and soybean-based thermoset for technical applications
- 2014
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Ingår i: Journal of reinforced plastics and composites (Print). - : SAGE. - 0731-6844 .- 1530-7964. ; 33:2, s. 193-201
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Tidskriftsartikel (refereegranskat)abstract
- Composites were developed by reinforcing available non-woven Lyocell and viscose in acrylated epoxidized soybean oil (AESO). Compression molding was used to make composites with 40–60 wt% fiber content. The fiber content comprises only Lyocell or viscose fiber, or mixture of these fibers in known ratio. Hybrid composites were made by a mixture of both the fibers in known ratio and it affects the properties. The effect of hybridization was evident in most tests which gives us an opportunity to tailor the properties according to requirement. Lyocell fiber reinforced composites with 60 wt% fiber content had a tensile strength and modulus of about 135 MPa and 17 GPa, respectively. Dynamic mechanical analysis showed that the Lyocell fiber reinforced composites had good viscoelastic properties. The viscose fiber reinforced composites had the high percentage elongation and also showed relatively good impact strength and flexural modulus. Good fiber-matrix adhesion reflected in mechanical properties. SEM images were made to see the fiber-matrix compatibility.
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| 5. |
- Ramamoorthy, Sunil Kumar, et al.
(författare)
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Regenerated Cellulose Fiber Reinforced Composites
- 2013
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Konferensbidrag (refereegranskat)abstract
- Wood pulp based regenerated cellulose fibers like Lyocell and viscose which are from natural origin have high and even quality; used to develop superior composites with good properties. In this project, Lyocell and viscose fibers were reinforced in chemically modified soybean based bio-matrix, acrylated epoxidized soybean oil (AESO) by compression molding technique. The composites are characterized for mechanical performance by tensile, flexural and impact tests, viscoelastic performance by dynamical mechanical thermal analysis (DMTA) and morphological analysis by scanning electron microscopy (SEM). In general, Lyocell composites had better tensile and flexural properties than viscose based composites. The same goes with elastic and viscous response of the composites. Hybrid composites were formed by fiber blending; on addition of Lyocell to viscose based composites improved the properties. The amount of Lyocell and viscose fibers used determined the properties of hybrid composites and the possibility of tailoring properties for specific application was seen. Hybrid composites showed better impact strength. Morphological analysis showed that the viscose composites had small fiber pull out whereas Lyocell composites had few pores. Hybrid composite analysis showed that they had uneven spreading of matrix; delamination occurred on constant heating and cooling. To overcome the above mentioned issue and to reduce the water absorption, surface modification of the fiber was done by alkali treatment and silane treatment. The effect of treatment is done through swelling, water absorption and morphological analysis tests. The properties could be increased on proper modification of the fibers. The results show the good potential of these composites to be used in automotives and construction industries.
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| 6. |
- Cavalli, Marco, et al.
(författare)
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Single Nuclei Transcriptome Analysis of Human Liver with Integration of Proteomics and Capture Hi-C Bulk Tissue Data
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Tidskriftsartikel (refereegranskat)abstract
- The liver is the largest solid organ and a primary metabolic hub. In recent years, intact cell nuclei were used to perform single-nuclei RNA-seq (snRNA-seq) for tissues difficult to dissociate and for flash-frozen archived tissue samples to discover unknown and rare cell sub-populations. In this study, we performed snRNA-seq of a liver sample to identify sub-populations of cells based on nuclear transcriptomics. In 4,282 single nuclei we detected on average 1,377 active genes and we identified seven major cell types. We integrated data from 94,286 distal interactions (p<0.05) for 7,682 promoters from a targeted chromosome conformation capture technique (HiCap) and mass spectrometry (MS) proteomics for the same liver sample. We observed a reasonable correlation between proteomics and in silico bulk snRNA-seq (r=0.47) using tissue-independent gene-specific protein abundancy estimation factors. We specifically looked at genes of medical importance. The DPYD gene is involved in the pharmacogenetics of fluoropyrimidines toxicity and some of its variants are analyzed for clinical purposes. We identified a new putative polymorphic regulatory element, which may contribute to variation in toxicity. Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and we investigated all known risk genes. We found a complex regulatory network for the SLC2A2 gene with 16 candidate enhancers. Three of them harbor somatic motif breaking and other mutations in HCC in the Pan Cancer Analysis of Whole Genomes dataset and are candidates to contribute to malignancy. Our results highlight the potential of a multi-omics approach in the study of human diseases.
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| 7. |
- Cavalli, Marco, et al.
(författare)
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Studies of liver tissue identify functional gene regulatory elements associated to gene expression, type 2 diabetes, and other metabolic diseases
- 2019
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Ingår i: Human Genomics. - : Springer Science and Business Media LLC. - 1473-9542 .- 1479-7364. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Background:Genome-wide association studies (GWAS) of diseases and traits have found associations to gene regions but not the functional SNP or the gene mediating the effect. Difference in gene regulatory signals can be detected using chromatin immunoprecipitation and next-gen sequencing (ChIP-seq) of transcription factors or histone modifications by aligning reads to known polymorphisms in individual genomes. The aim was to identify such regulatory elements in the human liver to understand the genetics behind type 2 diabetes and metabolic diseases.Methods: The genome of liver tissue was sequenced using 10X Genomics technology to call polymorphic positions. Using ChIP-seq for two histone modifications, H3K4me3 and H3K27ac, and the transcription factor CTCF, and our established bioinformatics pipeline, we detected sites with significant difference in signal between the alleles.Results:We detected 2329 allele-specific SNPs (AS-SNPs) including 25 associated to GWAS SNPs linked to liver biology, e.g., 4 AS-SNPs at two type 2 diabetes loci. Two hundred ninety-two AS-SNPs were associated to liver gene expression in GTEx, and 134 AS-SNPs were located on 166 candidate functional motifs and most of them in EGR1-binding sites.Conclusions:This study provides a valuable collection of candidate liver regulatory elements for further experimental validation.
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| 8. |
- Das, Sarbashis, et al.
(författare)
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Transcriptomics of cardiac biopsies reveals differences in patients with or without diagnostic parameters for heart failure with preserved ejection fraction
- 2019
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Heart failure affects 2-3% of adult Western population. Prevalence of heart failure with preserved left ventricular (LV) ejection fraction (HFpEF) increases. Studies suggest HFpEF patients to have altered myocardial structure and functional changes such as incomplete relaxation and increased cardiac stiffness. We hypothesised that patients undergoing elective coronary bypass surgery (CABG) with HFpEF characteristics would show distinctive gene expression compared to patients with normal LV physiology. Myocardial biopsies for mRNA expression analysis were obtained from sixteen patients with LV ejection fraction >= 45%. Five out of 16 patients (31%) had echocardiographic characteristics and increased NTproBNP levels indicative of HFpEF and this group was used as HFpEF proxy, while 11 patients had Normal LV physiology. Utilising principal component analysis, the gene expression data clustered into two groups, corresponding to HFpEF proxy and Normal physiology, and 743 differentially expressed genes were identified. The associated top biological functions were cardiac muscle contraction, oxidative phosphorylation, cellular remodelling and matrix organisation. Our results also indicate that upstream regulatory events, including inhibition of transcription factors STAT4, SRF and TP53, and activation of transcription repressors HEY2 and KDM5A, could provide explanatory mechanisms to observed gene expression differences and ultimately cardiac dysfunction in the HFpEF proxy group.
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| 9. |
- Diamanti, Klev, 1987-, et al.
(författare)
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Integration of whole-body [18F]FDG PET/MRI with non-targeted metabolomics can provide new insights on tissue-specific insulin resistance in type 2 diabetes
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Alteration of various metabolites has been linked to type 2 diabetes (T2D) and insulin resistance. However, identifying significant associations between metabolites and tissue-specific phenotypes requires a multi-omics approach. In a cohort of 42 subjects with different levels of glucose tolerance (normal, prediabetes and T2D) matched for age and body mass index, we calculated associations between parameters of whole-body positron emission tomography (PET)/magnetic resonance imaging (MRI) during hyperinsulinemic euglycemic clamp and non-targeted metabolomics profiling for subcutaneous adipose tissue (SAT) and plasma. Plasma metabolomics profiling revealed that hepatic fat content was positively associated with tyrosine, and negatively associated with lysoPC(P-16:0). Visceral adipose tissue (VAT) and SAT insulin sensitivity (Ki), were positively associated with several lysophospholipids, while the opposite applied to branched-chain amino acids. The adipose tissue metabolomics revealed a positive association between non-esterified fatty acids and, VAT and liver Ki. Bile acids and carnitines in adipose tissue were inversely associated with VAT Ki. Furthermore, we detected several metabolites that were significantly higher in T2D than normal/prediabetes. In this study we present novel associations between several metabolites from SAT and plasma with the fat fraction, volume and insulin sensitivity of various tissues throughout the body, demonstrating the benefit of an integrative multi-omics approach.
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| 10. |
- Diamanti, Klev, 1987-, et al.
(författare)
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Integration of whole-body PET/MRI with non-targeted metabolomics provides new insights into insulin sensitivity of various tissues
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: Alteration of various metabolites has been linked to type 2 diabetes (T2D) and insulin resistance. However, identifying significant associations between metabolites and tissue-specific alterations is challenging and requires a multi-omics approach. In this study, we aimed at discovering associations of metabolites from subcutaneous adipose tissue (SAT) and plasma with the volume, the fat fraction (FF) and the insulin sensitivity (Ki) of specific tissues using [18F]FDG PET/MRI.Materials and Methods: In a cohort of 42 subjects with different levels of glucose tolerance (normal, prediabetes and T2D) matched for age and body-mass-index (BMI) we calculated associations between parameters of whole-body FDG PET/MRI during clamp and non-targeted metabolomics profiling for SAT and blood plasma. We also used a rule-based classifier to identify a large collection of prevalent patterns of co-dependent metabolites that characterize non-diabetes (ND) and T2D.Results: The plasma metabolomics profiling revealed that hepatic fat content was positively associated with tyrosine, and negatively associated with lysoPC(P-16:0). Ki in visceral adipose tissue (VAT) and SAT, was positively associated with several species of lysophospholipids while the opposite applied to branched-chain amino acids (BCAA) and their intermediates. The adipose tissue metabolomics revealed a positive association between non-esterified fatty acids and, VAT and liver Ki. On the contrary, bile acids and carnitines in adipose tissue were inversely associated with VAT Ki. Finally, we presented a transparent machine-learning model that predicted ND or T2D in “unseen” data with an accuracy of 78%.Conclusions: Novel associations of several metabolites from SAT and plasma with the FF, volume and insulin senstivity of various tissues throughout the body were discovered using PET/MRI and a new integrative multi-omics approach. A promising computational model that predicted ND and T2D with high certainty, suggested novel non-linear interdependencies of metabolites.
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| 11. |
- Frisk, Christoffer, et al.
(författare)
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Cardiac biopsies reveal differences in transcriptomics between left and right ventricle in patients with or without diagnostic signs of heart failure
- 2024
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- New or mild heart failure (HF) is mainly caused by left ventricular dysfunction. We hypothesised that gene expression differ between the left (LV) and right ventricle (RV) and secondly by type of LV dysfunction. We compared gene expression through myocardial biopsies from LV and RV of patients undergoing elective coronary bypass surgery (CABG). Patients were categorised based on LV ejection fraction (EF), diastolic function and NT-proBNP into pEF (preserved; LVEF ≥ 45%), rEF (reduced; LVEF < 45%) or normal LV function. Principal component analysis of gene expression displayed two clusters corresponding to LV and RV. Up-regulated genes in LV included natriuretic peptides NPPA and NPPB, transcription factors/coactivators STAT4 and VGLL2, ion channel related HCN2 and LRRC38 associated with cardiac muscle contraction, cytoskeleton, and cellular component movement. Patients with pEF phenotype versus normal differed in gene expression predominantly in LV, supporting that diastolic dysfunction and structural changes reflect early LV disease in pEF. DKK2 was overexpressed in LV of HFpEF phenotype, potentially leading to lower expression levels of β-catenin, α-SMA (smooth muscle actin), and enhanced apoptosis, and could be a possible factor in the development of HFpEF. CXCL14 was down-regulated in both pEF and rEF, and may play a role to promote development of HF.
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| 12. |
- Hage, Camilla, et al.
(författare)
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Metabolomic Profile in HFpEF vs HFrEF Patients
- 2020
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Ingår i: Journal of Cardiac Failure. - : Elsevier BV. - 1071-9164 .- 1532-8414. ; 26:12, s. 1050-1059
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Tidskriftsartikel (refereegranskat)abstract
- Background: Heart failure with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF) are associated with metabolic derangements, which may have different pathophysiological implications.Methods and Results: In new-onset HFpEF (EF of >= 50%, n = 46) and HFrEF (EF of <40%, n = 75) patients, 109 endogenous plasma metabolites including amino acids, phospholipids and acylcarnitines were assessed using targeted metabolomics. Differentially altered metabolites and associations with clinical characteristics were explored. Patients with HFpEF were older, more often female with hypertension, atrial fibrillation, and diabetes compared with patients with HFrEF. Patients with HFpEF displayed higher levels of hydroxyproline and symmetric dimethyl arginine, alanine, cystine, and kynurenine reflecting fibrosis, inflammation and oxidative stress. Serine, cGMP, cAMP, L-carnitine, lysophophatidylcholine (18:2), lactate, and arginine were lower compared with patients with HFrEF. In patients with HFpEF with diabetes, kynurenine was higher (P = .014) and arginine lower (P = .014) vs patients with no diabetes, but did not differ with diabetes status in HFrEF. Decreasing kynurenine was associated with higher eGFR only in HFpEF (P-interaction = .020).Conclusions: Patients with new-onset HFpEF compared with patients with new-onset HFrEF display a different metabolic profile associated with comorbidities, such as diabetes and kidney dysfunction. HFpEF is associated with indices of increased inflammation and oxidative stress, impaired lipid metabolism, increased collagen synthesis, and downregulated nitric oxide signaling. Together, these findings suggest a more predominant systemic microvascular endothelial dysfunction and inflammation linked to increased fibrosis in HFpEF compared with HFrEF.
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| 13. |
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| 14. |
- Pan, Gang, et al.
(författare)
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rs953413 Regulates Polyunsaturated Fatty Acid Metabolism by Modulating ELOVL2 Expression
- 2020
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Ingår i: iScience. - : Elsevier BV. - 2589-0042. ; 23:2
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Tidskriftsartikel (refereegranskat)abstract
- Long-chain polyunsaturated fatty acids (LC-PUFAs) influence human health in several areas, including cardiovascular disease, diabetes, fatty liver disease, and cancer. ELOVL2 encodes one of the key enzymes in the in vivo synthesis of LC-PUFAs from their precursors. Variants near ELOVL2 have repeatedly been associated with levels of LC-PUFA-derived metabolites in genome-wide association studies (GWAS), but the mechanisms behind these observations remain poorly defined. In this study, we found that rs953413, located in the first intron of ELOVL2, lies within a functional FOXA and HNF4α cooperative binding site. The G allele of rs953413 increases binding of FOXA1/FOXA2 and HNF4α to an evolutionarily conserved enhancer element, conferring allele-specific upregulation of the rs953413-associated gene ELOVL2. The expression of ELOVL2 was significantly downregulated by both FOXA1 and HNF4α knockdown and CRISPR/Cas9-mediated direct mutation to the enhancer element. Our results suggest that rs953413 regulates LC-PUFAs metabolism by altering ELOVL2 expression through FOXA1/FOXA2 and HNF4α cooperation.
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