Dataset Information

The red blood cell as a mediator of endothelial dysfunction in patients with familial hypercholesterolemia and dyslipidemia.

ABSTRACT:

Background

Patients with familial hypercholesterolemia (FH) display high levels of low-density lipoprotein cholesterol (LDL-c), endothelial dysfunction, and increased risk of premature atherosclerosis. We have previously shown that red blood cells (RBCs) from patients with type 2 diabetes induce endothelial dysfunction through increased arginase 1 and reactive oxygen species (ROS).

Objective

To test the hypothesis that RBCs from patients with FH (FH-RBCs) and elevated LDL-c induce endothelial dysfunction.

Methods and results

FH-RBCs and LDL-c >5.0 mM induced endothelial dysfunction following 18-h incubation with isolated aortic rings from healthy rats compared to FH-RBCs and LDL-c <2.5 mM or RBCs from healthy subjects (H-RBCs). Inhibition of vascular but not RBC arginase attenuated the degree of endothelial dysfunction induced by FH-RBCs and LDL-c >5.0 mM. Furthermore, arginase 1 but not arginase 2 was elevated in the vasculature of aortic segments after incubation with FH-RBCs and LDL-c >5.0 mM. A superoxide scavenger, present throughout the 18-h incubation, attenuated the degree of endothelial dysfunction induced by FH-RBCs and LDL-c >5.0 mM. ROS production was elevated in these RBCs in comparison with H-RBCs. Scavenging of vascular ROS through various antioxidants also attenuated the degree of endothelial dysfunction induced by FH-RBCs and LDL-c >5.0 mM. This was corroborated by an increase in the lipid peroxidation product 4-hydroxynonenal. Lipidomic analysis of RBC lysates did not reveal any significant changes across the groups.

Conclusion

FH-RBCs induce endothelial dysfunction dependent on LDL-c levels via arginase 1 and ROS-dependent mechanisms.

SUBMITTER: Mahdi A

PROVIDER: S-EPMC10092865 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature

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Publications

The red blood cell as a mediator of endothelial dysfunction in patients with familial hypercholesterolemia and dyslipidemia.

Mahdi Ali A Wodaje Tigist T Kövamees Oskar O Tengbom John J Zhao Allan A Jiao Tong T Henricsson Marcus M Yang Jiangning J Zhou Zhichao Z Nieminen Anni I AI Levin Malin M Collado Aida A Brinck Jonas J Pernow John J

Journal of internal medicine 20221102 2

<h4>Background</h4>Patients with familial hypercholesterolemia (FH) display high levels of low-density lipoprotein cholesterol (LDL-c), endothelial dysfunction, and increased risk of premature atherosclerosis. We have previously shown that red blood cells (RBCs) from patients with type 2 diabetes induce endothelial dysfunction through increased arginase 1 and reactive oxygen species (ROS).<h4>Objective</h4>To test the hypothesis that RBCs from patients with FH (FH-RBCs) and elevated LDL-c induce ...[more]

PMID: 36324273

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Project description:Familial hypercholesterolemia (FH) is a lipoprotein disorder characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C) and an increased risk of premature atherosclerotic cardiovascular disease. Recent evidences have shown that several glycerophospholipid species were markedly altered in experimental FH animals and exhibited diverse bioactivities. Nevertheless, the glycerophospholipid profiles and their associated biological implications in human FH remain largely unknown. In this study, we sought to comprehensively delineate the glycerophospholipid phenotypes in human FH and to investigate the functional roles of key FH-altered glycerophospholipid molecules on cholesterol metabolism. Targeted analysis of 328 glycerophospholipid metabolites was used to profile the differentiated alterations in patients with homozygous FH (HoFH; n = 181), heterozygous FH (HeFH; n = 452), and non-FH hypercholesterolemia (n = 382). Our findings revealed that the glycerophospholipid phenotypes of FH and non-FH hypercholesterolemia were dominated by a spectrum of metabolites involved in the lysophosphatidic acid (LPA) metabolism. Among the LPA features, palmitoyl-LPA (16:0) showed significant association with the clinical levels of LDL-C and total cholesterol in HoFH and HeFH populations. Using functional metabolomic strategy and murine FH model, we demonstrated that supplementation with LPA 16:0 elevated the plasma levels of LDL and free/esterified cholesterol and exacerbated the atherosclerotic lesions. Conversely, inhibition of autotaxin-mediated LPA 16:0 production significantly ameliorated dyslipidemia. Mechanistically, we uncovered that LPA 16:0 could disrupt hepatic cholesterol homeostasis by impairing cholesterol excretion and inhibiting primary bile acid synthesis. In summary, our study offers novel insights into lipid metabolism in human FH and posits that targeting LPA metabolism may represent a promising therapeutic strategy for reducing cholesterol levels in the FH population.

Project description:Background: Elevated plasma cholesterol promotes the formation of atherosclerotic lesions in which monocyte-derived lipid-laden macrophages are frequently found. To analyze, if circulating monocytes already show increased lipid content and differences in lipoprotein metabolism, we compared monocytes from patients with Familial Hypercholesterolemia (FH) with those from healthy individuals. Methods: Cholesterol and oxidized cholesterol metabolite serum levels of FH and of healthy, gender/age matched control subjects were measured by combined gas chromatography ? mass spectroscopy. Monocytes from patients with FH and from healthy subjects were isolated by antibody-assisted density centrifugation. Gene expression profiles of isolated monocytes were measured using Affymetrix HG-U 133 Plus 2.0 microarrays. We compared monocyte gene expression profiles from FH patients with healthy controls using a Welch T-test with correction for multiple testing (p < 0.05; Benjamini Hochberg correction, False Discovery Rate = 0.05). The differential expression of FH associated genes was validated at the mRNA level by qRT-PCR and/or at the protein level by Western Blot or flow cytometry. Functional validation of monocyte scavenger receptor activities were done by binding assays and dose/time dependent uptake analysis using native and oxidized LDL. Results: Using microarray analysis we found in FH patients a significant up-regulation of 1,617 genes and a down-regulation of 701 genes compared to monocytes from healthy individuals. These include genes of proteins that are involved in the uptake, biosynthesis, disposition, and cellular efflux of cholesterol. In addition, plasma from FH patients contains elevated amounts of sterols and oxysterols. An increased uptake of oxidized as well as of native LDL by FH monocytes combined with a down-regulation of NPC1 and ABCA1 explains the lipid accumulation observed in these cells. Conclusion: Our data demonstrate that circulating FH monocytes show differences in cell physiology that may contribute to the early onset of atherosclerosis in this disease. Keywords: Micro-array analysis, cell type comparison,

Project description:BackgroundHomozygous familial hypercholesterolemia (HoFH) is a rare genetic disorder characterized by severely elevated low-density lipoprotein cholesterol (LDL-C) levels due to profoundly defective LDL receptor (LDLR) function. Given that severely elevated LDL-C starts in utero, atherosclerosis often presents during childhood or adolescence, creating a largely unmet need for aggressive LDLR-independent lipid-lowering therapies in young patients with HoFH. Here we present the first evaluation of the efficacy and safety of evinacumab, a novel LDLR-independent lipid-lowering therapy, in pediatric patients with HoFH from parts A and B of a 3-part study.MethodsThe phase 3, part B, open-label study treated 14 patients 5 to 11 years of age with genetically proven HoFH (true homozygotes and compound heterozygotes) with LDL-C >130 mg/dL, despite optimized lipid-lowering therapy (including LDLR-independent apheresis and lomitapide), with intravenous evinacumab 15 mg/kg every 4 weeks.ResultsEvinacumab treatment rapidly and durably (through week 24) decreased LDL-C with profound reduction in the first week, with a mean (SE) LDL-C reduction of -48.3% (10.4%) from baseline to week 24. ApoB (mean [SE], -41.3% [9.0%]), non-high-density lipoprotein cholesterol (-48.9% [9.8%]), and total cholesterol (-49.1% [8.1%]) were similarly decreased. Treatment-emergent adverse events were reported in 10 (71.4%) patients; however, only 2 (14.3%) reported events that were considered to be treatment-related (nausea and abdominal pain). One serious treatment-emergent adverse event of tonsillitis occurred (n=1), but this was not considered treatment-related.ConclusionsEvinacumab constitutes a new treatment for pediatric patients with HoFH and inadequately controlled LDL-C despite optimized lipid-lowering therapy, lowering LDL-C levels by nearly half in these extremely high-risk and difficult-to-treat individuals.RegistrationURL: https://www.clinicaltrials.gov; Unique identifier: NCT04233918.

Dataset Information

The red blood cell as a mediator of endothelial dysfunction in patients with familial hypercholesterolemia and dyslipidemia.

Background

Objective

Methods and results

Conclusion

Publications

The red blood cell as a mediator of endothelial dysfunction in patients with familial hypercholesterolemia and dyslipidemia.

Similar Datasets

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