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- Bandaru, Manoj Kumar, 1987-, et al.
(författare)
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Apoc2 mutant zebrafish: a model for hypertriglyceridemia and early-stage atherosclerosis
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Zebrafish larvae in a hypertriglyceridemic background can be useful to identify and characterize causal genes for triglyceride metabolism. A previous, small-scale study suggested that apolipoprotein C-II (apoc2)-mutant zebrafish larvae can be used to model hypertriglyceridemia-induced atherosclerosis. We aimed to replicate these findings in a large-scale study and asses if APOC-II may represent a useful therapeutic target. We generated apoc2 mutant zebrafish using CRISPR-Cas9 and examined cardiometabolomic traits in their offspring (F1 generation). Systematic characterization of 384 larvae using our image and assay-based, high-throughput pipeline showed that compound heterozygous larvae for loss of function mutations in apoc2 (n=35) have higher whole-body levels of triglycerides (0.71±0.16 SD), HDL cholesterol (0.32±0.15 SD) and total cholesterol (0.37±0.18 SD), and a trend for lower whole-body glucose levels (0.23±0.14 SD) compared with larvae without mutations in apoc2 (n=174). Such larvae also tended to have more vascular lipid deposition, however this effect did not reach significance (P=0.12). Interestingly, the trends for lower whole-body glucose levels and more vascular lipid deposition in larvae with anticipated loss of functional apoc2 reached significance when larvae (n=3812) from other screens, in which apoc2 was not experimentally perturbed were included as additional wildtype controls. Thus, our large-scale study confirms the role of apoc2 in hypertriglyceridemia and early-stage atherosclerosis. While apoc2 mutant zebrafish model can be used as a genetic background to identify and characterize causal genes for triglyceride metabolism, independent and opposite effects on triglycerides and glucose suggest that APOC-II is likely not a suitable target for prevention and treatment of coronary artery disease.
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| 2. |
- Bandaru, Manoj Kumar, 1987-, et al.
(författare)
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Image-based, in vivo characterization of cardiometabolic consequences of mutations in pcsk9
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Based on the association of loss-of-function mutations in proprotein convertase subtilisin/kexin type 9 (PCSK9) with low plasma LDL cholesterol levels, inhibition of the PCSK9 protein using monoclonal antibodies have emerged as an effective treatment option to lower LDL cholesterol levels and reduce the risk of coronary artery disease. Despite these beneficial effects, PCSK9 inhibitors may increase the risk of diabetes. In this study, we mimicked the mechanistic action of PCSK9 inhibitors in humans by inducing mutations in pcsk9 in zebrafish and examining their effects on dyslipidemia, early-stage atherosclerosis and diabetes-related traits in data from nearly 5000 zebrafish larvae. At 10 days of age, larvae with mutations in pcsk9 were characterized by lower whole-body LDL cholesterol levels (beta±SE -0.056±0.025 SD units) and protection against early-stage atherosclerosis, with less vascular lipid deposition (-0.133±0.035 SD) and less co-localization of macrophages with lipids (-0.086±0.032 SD). Mutant larvae also had fewer pancreatic β-cells (-0.153±0.055 SD). Thus, our findings in pcsk9 mutant larvae are in line with results from people carrying loss-of-function PCSK9 mutations, and are also in line with the effects of PCSK9 inhibitors in humans. Further, our results suggest that mutations in pcsk9 may increase the risk of diabetes through a direct effect on pancreatic β-cells.
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| 4. |
- Nowak, Christoph, et al.
(författare)
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Metabolite profiles during an oral glucose tolerance test reveal new associations with clamp-measured insulin sensitivity
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Impaired insulin sensitivity (IS) is a major risk factor for cardiovascular disease and type 2 diabetes. Metabolomic profiling during an oral glucose tolerance test (OGTT) can reveal early pathogenic alterations in healthy individuals. Our aim was to identify IS biomarkers and gain new pathophysiologic insights by applying untargeted metabolomics to repeated OGTT plasma samples in association with a hyperinsulinemic-euglycemic clamp assessment. We studied 192 metabolites identified by non-targeted liquid chromatography/mass spectrometry in plasma samples taken at 0, 30, and 120 min during an OGTT in 470 non-diabetic 71-yr-old men. Insulin sensitivity was associated with 35 metabolites at one or more time points in multivariable-adjusted linear regression. The trajectories of nine metabolites during the OGTT were related to IS, six of which (oleic and palmitoleic acid, decanoyl- and dodecanoylcarnitine, deoxycholate-glycine and hexose) showed no associations with IS in the baseline fasting state. The strongest effects were detected for medium-chain acylcarnitines, which increased between 30-120 min in insulin-resistant individuals compared to those with normal IS. In this large community sample, we identified novel associations between clamp-measured IS and metabolite profiles that became apparent only after an oral glucose challenge. Associations of differential medium-chain acylcarnitine and monounsaturated fatty acid trajectories with IS provide new insights into the pathogenesis of insulin resistance.
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| 5. |
- Nowak, Christoph, et al.
(författare)
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Type 2 diabetes, glycaemic traits and cardiovascular disease : a Mendelian Randomization study
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Type 2 diabetes (T2D) and its hallmarks insulin resistance, impaired insulin secretion, and hyperglycaemia affect over 400 million persons worldwide and are associated with raised cardiovascular risk, but their causal role has been difficult to dissect due to overlap between risk factors. We used Mendelian randomization analysis, which utilises genetic polymorphisms associated with a risk factor, to assess causal effects of T2D, insulin resistance, insulin secretion, and fasting glucose on mortality, ischaemic stroke, and coronary artery disease (CAD) risk in 120,091 adults in the UK Biobank and in the CARDIoGRAMplusC4D consortium (63,746 cases of CAD and 130,681 controls). We found evidence for a causal effect of T2D on raised CAD risk (odds ratio (OR) per doubling in the odds of T2D, 1.07, 95% confidence interval (CI) 1.05 – 1.09, P = 1.2 x 10-9) and for a causal effect of impaired insulin secretion on the risk of CAD (OR per SD-unit decrease, 1.14, 95% CI 1.06 – 1.22, P = 0.002). The genetic score for insulin resistance was associated with increased coronary artery disease risk; however, sensitivity analysis indicated that the instrument might not be appropriate to use for robust causal inference testing. Our results support previous reports of a causal role of T2D and impaired insulin secretion in coronary artery disease and point to a complex relationship between variants affecting insulin resistance and cardiovascular outcomes.
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