| 1. |
- Björnson, Elias, 1988, et al.
(författare)
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Lipid profiling of human diabetic myocardium reveals differences in triglyceride fatty acyl chain length and degree of saturation.
- 2020
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Ingår i: International journal of cardiology. - : Elsevier BV. - 1874-1754 .- 0167-5273. ; 320, s. 106-111
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Tidskriftsartikel (refereegranskat)abstract
- Type 2 diabetes is a major health problem in the world, and is strongly associated with impaired cardiac function and increased mortality. The causal relationship between type 2 diabetes and impaired cardiac function is still incompletely understood but changes in the cardiac lipid metabolism are believed to be a contributing factor. The objective of this study was to determine the lipid profile in human myocardial biopsies collected in vivo from patients with type 2 diabetes and compare to non-diabetic controls.We conducted full lipidomics analyses, using mass spectrometry, of 85 right atrial biopsies obtained from diabetic and non-diabetic patients undergoing elective cardiac surgery. The patients were characterized clinically and serum was analyzed for lipids and biochemical markers.The groups did not differ in BMI and in circulating triglycerides. We demonstrate that type 2 diabetes is associated with alterations in the cardiac lipidome. Interestingly, the absolute amount of lipids is not altered in the diabetic myocardium. However, triglycerides with longer fatty acyl chains are more abundant and there is a higher degree of unsaturated fatty acid chains in triglycerides in diabetic myocardium.Our study reveals that type 2 diabetes is a relatively strong determinant of the human cardiac lipidome (compared to other clinical variables). Although the total lipid content in the diabetic myocardium is not increased, the lipid composition is markedly affected.
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| 2. |
- Gizurarson, Sigfus, et al.
(författare)
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Atrial fibrillation in patients admitted to coronary care units in western Sweden - focus on obesity and lipotoxicity.
- 2015
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Ingår i: Journal of electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 48:5, s. 853-60
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Tidskriftsartikel (refereegranskat)abstract
- Atrial fibrillation (AF) is the most common form of arrhythmia in humans and is associated with substantial morbidity and mortality. Obesity and diabetes have been linked to myocardial lipotoxicity - a condition where the heart accumulates and produces toxic lipid species. We hypothesized that obesity and diabetes were involved in the pathophysiology of AF by means of promoting a lipotoxic phenotype in atrial muscle, and that AF predicts mortality in cardiac care patients.
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| 3. |
- Klevstig, Martina, et al.
(författare)
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Cardiac expression of the microsomal triglyceride transport protein protects the heart function during ischemia
- 2019
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Ingår i: Journal of Molecular and Cellular Cardiology. - : Elsevier BV. - 0022-2828 .- 1095-8584. ; 137, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Aims: The microsomal triglyceride transport protein (MTTP) is critical for assembly and secretion of apolipoprotein B (apoB)-containing lipoproteins and is most abundant in the liver and intestine. Surprisingly, MTTP is also expressed in the heart. Here we tested the functional relevance of cardiac MTTP expression. Materials and methods: We combined clinical studies, advanced expression analysis of human heart biopsies and analyses in genetically modified mice lacking cardiac expression of the MTTP-A isoform of MTTP. Results: Our results indicate that lower cardiac MTTP expression in humans is associated with structural and perfusion abnormalities in patients with ischemic heart disease. MTTP-A deficiency in mice heart does not affect total MTTP expression, activity or lipid concentration in the heart. Despite this, MTTP-A deficient mice displayed impaired cardiac function after a myocardial infarction. Expression analysis of MTTP indicates that MTTP expression is linked to cardiac function and responses in the heart. Conclusions: Our results indicate that MTTP may play an important role for the heart function in conjunction to ischemic events.
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| 4. |
- Klevstig, Martina, et al.
(författare)
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Targeting acid sphingomyelinase reduces cardiac ceramide accumulation in the post-ischemic heart
- 2016
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Ingår i: Journal of Molecular and Cellular Cardiology. - : Elsevier BV. - 0022-2828 .- 1095-8584. ; 93, s. 69-72
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Tidskriftsartikel (refereegranskat)abstract
- Ceramide accumulation is known to accompany acute myocardial ischemia, but its role in the pathogenesis of ischemic heart disease is unclear. In this study, we aimed to determine how ceramides accumulate in the ischemic heart and to determine if cardiac function following ischemia can be improved by reducing ceramide accumulation. To investigate the association between ceramide accumulation and heart function, we analyzed myocardial left ventricle biopsies from subjects with chronic ischemia and found that ceramide levels were higher in biopsies from subjects with reduced heart function. Ceramides are produced by either de novo synthesis or hydrolysis of sphingomyelin catalyzed by acid and/or neutral sphingomyelinase. We used cultured HL-1 cardiomyocytes to investigate these pathways and showed that acid sphingomyelinase activity rather than neutral sphingomyelinase activity or de novo sphingolipid synthesis was important for hypoxia-induced ceramide accumulation. We also used mice with a partial deficiency in acid sphingomyelinase (Smpd1(+/-) mice) to investigate if limiting ceramide accumulation under ischemic conditions would have a beneficial effect on heart function and survival. Although we showed that cardiac ceramide accumulation was reduced in Smpd1(+/-) mice 24 h after an induced myocardial infarction, this reduction was not accompanied by an improvement in heart function or survival. Our findings show that accumulation of cardiac ceramides in the post-ischemic heart is mediated by acid sphingomyelinase. However, targeting ceramide accumulation in the ischemic heart may not be a beneficial treatment strategy.
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| 5. |
- Perman, Jeanna, 1981, et al.
(författare)
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The VLDL receptor promotes lipotoxicity and increases mortality in mice following an acute myocardial infarction.
- 2011
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Ingår i: The Journal of clinical investigation. - : American Society for Clinical Investigation. - 1558-8238 .- 0021-9738. ; 121:7, s. 2625-40
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Tidskriftsartikel (refereegranskat)abstract
- Impaired cardiac function is associated with myocardial triglyceride accumulation, but it is not clear how the lipids accumulate or whether this accumulation is detrimental. Here we show that hypoxia/ischemia-induced accumulation of lipids in HL-1 cardiomyocytes and mouse hearts is dependent on expression of the VLDL receptor (VLDLR). Hypoxia-induced VLDLR expression in HL-1 cells was dependent on HIF-1α through its interaction with a hypoxia-responsive element in the Vldlr promoter, and VLDLR promoted the endocytosis of lipoproteins. Furthermore, VLDLR expression was higher in ischemic compared with nonischemic left ventricles from human hearts and was correlated with the total lipid droplet area in the cardiomyocytes. Importantly, Vldlr-/- mice showed improved survival and decreased infarct area following an induced myocardial infarction. ER stress, which leads to apoptosis, is known to be involved in ischemic heart disease. We found that ischemia-induced ER stress and apoptosis in mouse hearts were reduced in Vldlr-/- mice and in mice treated with antibodies specific for VLDLR. These findings suggest that VLDLR-induced lipid accumulation in the ischemic heart worsens survival by increasing ER stress and apoptosis.
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