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- Bandaru, Manoj Kumar, 1987-, et al.
(author)
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Apoc2 mutant zebrafish: a model for hypertriglyceridemia and early-stage atherosclerosis
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Other publication (other academic/artistic)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.
(author)
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Image-based, in vivo characterization of cardiometabolic consequences of mutations in pcsk9
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Other publication (other academic/artistic)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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- Brunet-Ratnasingham, Elsa, et al.
(author)
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Sustained IFN signaling is associated with delayed development of SARS-CoV-2-specific immunity
- 2023
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Other publication (other academic/artistic)abstract
- Plasma RNAemia, delayed antibody responses and inflammation predict COVID-19 outcomes, but the mechanisms underlying these immunovirological patterns are poorly understood. We profile 782 longitudinal plasma samples from 318 hospitalized COVID-19 patients. Integrated analysis using k-means reveal four patient clusters in a discovery cohort: mechanically ventilated critically-ill cases are subdivided into good prognosis and high-fatality clusters (reproduced in a validation cohort), while non-critical survivors are delineated by high and low antibody responses. Only the high-fatality cluster is enriched for transcriptomic signatures associated with COVID-19 severity, and each cluster has distinct RBD-specific antibody elicitation kinetics. Both critical and non-critical clusters with delayed antibody responses exhibit sustained IFN signatures, which negatively correlate with contemporaneous RBD-specific IgG levels and absolute SARS-CoV-2-specific B and CD4+ T cell frequencies. These data suggest that the “Interferon paradox” previously described in murine LCMV models is operative in COVID-19, with excessive IFN signaling delaying development of adaptive virus-specific immunity.
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