Arteriosclerosis, Thrombosis, and Vascular Biology最新文献

Background: Endotheliopathy and coagulopathy are known complications of COVID-19, with a significant association with mortality. Although dexamethasone is the standard of care for patients with severe COVID-19, its precise mode of action remains elusive. We aim to investigate the functional consequences of dexamethasone treatment on COVID-19-associated procoagulant endotheliopathy.

Methods: First, during the 7 days after hospitalization, we measured several endothelial and coagulopathy biomarkers in a prospective cohort of patients with COVID-19 with acute respiratory distress syndrome (ARDS) who were either treated or not with both dexamethasone and therapeutic UFH (unfractionated heparin). Second, we developed an in vitro thrombin generation assay on cultured human endothelial cells to measure the ability of stimulated endothelial colony-forming cells to activate coagulation in normal plasma, which is expressed as an endogenous thrombin potential (ETP).

Results: Among the cohort of 44 ARDS COVID-19 patients, 23 patients treated with dexamethasone and therapeutic UFH had significantly decreased von Willebrand Factor, Ang-2 (angiopoietin-2), soluble E-selectin, and d-dimer levels over 7 days. To differentiate the effect of UFH and dexamethasone on endotheliopathy, we used the thrombin generation assay and showed that endothelial colony-forming cell stimulation with dexamethasone but not UFH-in addition to a cocktail of proinflammatory cytokines (to mimic the cytokine storm of severe COVID-19)-significantly decreased ETP in comparison to proinflammatory cytokines only. Moreover, in another cohort of 331 patients with COVID-19 of varying severity, the endothelial colony-forming cell stimulation with the plasma of 87 ARDS patients showed significantly higher ETP (1260 nmol/L per minute [interquartile range, 1140-1260]) compared with 75 non-ARDS patients (1024 nmol/L per minute [interquartile range, 915-1200]; P<0.001). Finally, 94 dexamethasone-treated ARDS patients had significantly lower ETP (962.8 nmol/L per minute [interquartile range, 782.9-1112]) in contrast to 75 nondexamethasone-treated ARDS patients (1,260 nmol/L per minute [interquartile range, 1140-1359]; P<0.001). ETP could help predict in-hospital mortality in a Kaplan-Meier estimator analysis (P=0.0002).

Conclusions: Our data suggest that dexamethasone protects against COVID-19 endothelium-induced coagulopathy. These findings are in line with the decreased prevalence of venous thrombosis among hospitalized patients with COVID-19 treated with dexamethasone.

Background: Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of lipid-laden foam cells and plaques within the arterial wall. Dysfunctional vascular smooth muscle cells (VSMCs), fibroblasts, endothelial cells, and macrophages contribute to disease progression. Here, we report that macrophage-specific expression of epsins, highly conserved endocytic adaptor proteins involved in clathrin-mediated endocytosis, accelerates atherosclerosis in Western diet-fed mice.

Methods: WT/Apoe^-/- (wild-type/Apoe-deficient) mice and littermates with a LysM-DKO/Apoe^-/- (myeloid-specific deletion of epsin 1/2 on an Apoe^-/- background) were generated and fed a Western diet for 16 weeks. Single-cell RNA sequencing was conducted to investigate the cellular and molecular mechanisms regulated by macrophage epsins during atherosclerosis. Findings from single-cell RNA sequencing were validated through metabolic profiling, qRT-PCR (quantitative reverse transcription polymerase chain reaction), immunostaining, and coculture experiments to assess associated phenotypic changes.

Results: LysM-DKO/Apoe^-/- mice exhibited significantly reduced atherosclerotic foam cell formation compared with WT/Apoe^-/- controls. Single-cell RNA sequencing analysis identified 19 major cell types, including 6 VSMC and 5 macrophage subpopulations. Modulated VSMC1 and VSMC2 subtypes were associated with inflammation, migration, and VSMC-to-macrophage transition. These populations, along with foamy-Trem2 and inflammatory macrophages, were markedly reduced in LysM-DKO/Apoe^-/- mice. Transition of modulated VSMC2 subtype into macrophages was significantly inhibited, as confirmed by both computational analysis and experimental validation. In addition, macrophage epsin deletion reversed endothelial dysfunction, suppressed cholesterol- and glucose-mediated signaling, and reduced expression of proinflammatory ligands IL (interleukin)-1β and TNF-α (tumor necrosis factor α).

Conclusions: Macrophage epsin deletion limits foam cell formation and preserves VSMC and endothelial cell phenotypes and functions. These findings reveal a potential therapeutic strategy targeting macrophage epsins to combat atherosclerosis.

Background: The underlying mechanisms of atherosclerosis and strategies for identifying high cardiovascular risk in psoriasis are incompletely understood. Platelet activity is increased in psoriasis and induces vascular dysfunction. We investigated the platelet phenotype and platelet transcriptome as one potential mechanism to explain cardiovascular risk in psoriasis.

Methods: Psoriasis and controls underwent platelet aggregation and activation studies and platelet RNA sequencing to generate a psoriasis platelet transcriptomic score. The relationship between the platelet transcriptomic score and cardiovascular risk was assessed by arterial stiffness, coronary calcium, and longitudinally in an independent cohort of high cardiovascular-risk individuals undergoing lower extremity arterial revascularization.

Results: Psoriasis subjects (n=73; median age, 51 years; body surface area of psoriasis, 3%) compared with controls (n=56; median age, 41 years) trended older (P=0.08) and had greater body mass index (P=0.01) and higher hs-CRP (high-sensitivity C-reactive protein) values (P=0.01). Platelet aggregation in response to collagen (P=0.0049) and ADP (P=0.033), and leukocyte-, neutrophil-, and lymphocyte-platelet aggregates (P<0.05 for each comparison) were all higher in psoriasis versus controls. Platelet RNA sequencing comparing 51 patients with psoriasis with 39 controls identified 329 upregulated and 345 downregulated genes (P<0.05). Pathway analysis identified dysregulated platelet activation, apoptosis, VEGF (vascular endothelial growth factor), interferon, senescence, IL (interleukin)-1, and clotting cascade signaling between psoriasis and controls. Using a phenotypic rank-based scoring methodology, a psoriasis platelet transcriptomic score comprised of 142 genes differentiated psoriasis from controls. This score correlated with arterial stiffness (r=0.26; P=0.031) and coronary calcium (r=0.58; P=0.0069). In a separate cohort of high cardiovascular-risk patients undergoing lower extremity arterial revascularization, the psoriasis platelet transcriptomic score associated with incident myocardial infarction (adjusted hazard ratio, 3.7 [95% CI, 1.4-10.1]; P=0.015).

Conclusions: Platelet aggregation and activation are increased in patients with controlled psoriatic disease, with the platelet transcriptome associated with proinflammatory, proatherothrombotic pathways, and cardiovascular risk. Our results warrant further investigation of platelet involvement promoting heightened cardiovascular disease in psoriasis.

Background: The pathogenesis of abdominal aortic aneurysm (AAA) formation involves vascular inflammation, thrombosis formation, and programmed cell death, leading to aortic remodeling. In this study, we deciphered the role of ferroptosis, an excessive iron-mediated cell death in macrophages during aortic inflammation and vascular remodeling in AAA formation.

Methods: Single-cell RNA sequencing analysis was performed on the human AAA tissue database. AAAs were induced in male and female C57BL/6 (wild-type) mice using 2 models with topical elastase or elastase+β-aminopropionitrile, with or without liproxstatin-1, a specific ferroptosis inhibitor, treatment. Aortic diameter, cytokine expression, histology, hallmarks of ferroptosis such as lipid peroxidation and glutathione, and lipid analysis using mass spectrometry were measured in aortic tissue extracts. In vitro studies deciphered the crosstalk of macrophages and smooth muscle cells and analyzed ferroptosis and MMP (matrix metalloproteinase) expressions.

Results: Single-cell RNA sequencing analysis demonstrated significant differences in ferroptosis-related genes in macrophages from human AAAs compared with control aortic tissue. Using 2 established murine models of AAA and aortic rupture in wild-type mice, we observed that treatment with liproxstatin-1 significantly attenuated aortic diameter, proinflammatory cytokine production, immune cell infiltration (neutrophils and macrophages), elastic fiber disruption, and increased smooth muscle cell α-actin expression compared with untreated mice. Lipidomic analysis using mass spectrometry shows a significant increase in ceramides and a decrease in intact lipid species levels in murine AAA tissue compared with controls in the murine AAA model. Mechanistically, in vitro studies demonstrate that liproxstatin-1 treatment of macrophages mitigated ferroptosis and MMP9 expression, as well as the crosstalk with aortic smooth muscle cells by downregulating MMP2 secretion.

Conclusions: Taken together, this study demonstrates that pharmacological inhibition by liproxstatin-1 mitigates macrophage-dependent ferroptosis, contributing to the inhibition of aortic inflammation and remodeling during AAA formation.

Background: The estimated glucose disposal rate (eGDR) is a validated surrogate marker of insulin resistance. However, its association with stroke and dementia in nondiabetic populations remains insufficiently investigated.

Methods: This prospective cohort study included nondiabetic participants from the UK Biobank. The outcomes in this study were stroke, ischemic stroke, hemorrhagic stroke, all-cause dementia, vascular dementia, and Alzheimer disease. Multivariable Cox regression and restricted cubic splines were used to examine the associations between eGDR and outcomes. Polygenic risk score analyses were applied to investigate interactions between eGDR and genetic risk.

Results: Overall, 430 093 participants were included. During a follow-up of around 13.5 years, 10 307 stroke cases and 11 137 all-cause dementia cases were recorded. Restricted cubic splines analyses indicated nonlinear associations between eGDR and the risks of stroke and vascular dementia. Below specific thresholds (<7.64 for stroke, <7.60 for ischemic stroke, <7.75 for hemorrhagic stroke, and <8.31 for vascular dementia), eGDR levels were not significantly associated with these outcomes except a modest inverse association with overall stroke risk (hazard ratio [HR] 0.97 [95% CI, 0.95-0.99]; P=0.012). In contrast, above these thresholds, higher eGDR levels were associated with significantly reduced risks of stroke (HR, 0.80 [95% CI, 0.78-0.82]; P<0.001), ischemic stroke (HR, 0.80 [95% CI, 0.78-0.81]; P<0.001), hemorrhagic stroke (HR, 0.81 [95% CI, 0.78-0.84]; P<0.001), and vascular dementia (HR, 0.89 [95% CI, 0.84-0.94]; P<0.001). A linear inverse relationship was observed between eGDR and all-cause dementia and Alzheimer disease. The HR in the highest versus lowest quartile was 0.81 (95% CI, 0.75-0.88) for all-cause dementia and 0.73 (95% CI, 0.64-0.84) for Alzheimer disease. Stratified polygenic risk score analyses revealed a synergistic interaction between reduced eGDR and elevated genetic susceptibility.

Conclusions: eGDR exhibited nonlinear associations with stroke and vascular dementia risk and linear inverse associations with all-cause dementia and Alzheimer disease in nondiabetic populations.

Background: Low wall shear stress (WSS) at arterial bifurcations and curves damages endothelial cells, promoting the development of atherosclerosis. Although the accumulation of iron in plaques has been observed, the mechanisms behind it and its effects are not fully understood.

Methods: Detect the iron content in different parts of the mouse partial carotid artery ligation model and the aorta. The chelating iron therapy was used to assess the impact of low WSS-induced iron accumulation and atherosclerosis in the arterial wall. In vitro experiments utilized human umbilical vein endothelial cells and an orbital-shaker model to simulate WSS. Mice with endothelial cell-specific knockout of IRP2 (iron regulatory protein 2) and deletion of Apoe (Apolipoprotein e; Apoe^-/-IRP2^iEcko) were constructed, as well as a human umbilical vein endothelial cell line with IRP2 knockdown.

Results: We investigated the iron accumulation induced by low WSS in carotid arteries. Hinokitiol, an iron chelator, was found to reduce this iron buildup and decrease the progression of atherosclerosis. Low WSS in the carotid arteries led to chronic iron accumulation, which altered the expression of iron metabolism-related proteins in endothelial cells, particularly IRP2. Knocking down IRP2 in endothelial cells resulted in an increase in the expression of inflammation-related proteins and a significant elevation in the expression of HIFs (hypoxia-inducible factors). Apoe^-/-IRP2^iEcko mice exhibited an increased susceptibility to atherosclerosis. The use of HIF inhibitors, PX-478 and PT-2385, was able to suppress the exacerbation of atherosclerosis in Apoe^-/- mice caused by the endothelial cell-specific knockout of IRP2.

Conclusions: Our results indicate that low WSS-induced endothelial cell iron metabolism abnormalities, by inducing arterial wall iron accumulation and abnormal expression of iron metabolism-related proteins, promote the occurrence and development of atherosclerosis. The use of iron chelators can alleviate the onset and progression of low WSS-induced atherosclerosis.

Background: Müller cells are the major retinal glial cell type and pivotal regulators of pathological neovascularization in ischemic retinopathy. There is great interest in identifying factors that govern Müller cells in vascular regulation. Nrf2 (NF-E2-related factor 2) plays a major protective role in regulating oxidative stress and inflammation. Our group previously discovered that both global and neuroretinal Nrf2 deficiency suppress retinal revascularization and promote pathological neovascularization in a mouse model of oxygen-induced retinopathy. Here, we investigate the cell-intrinsic role of Nrf2 in Müller cells on retinal angiogenesis.

Methods: The role of Müller cell Nrf2 in retinal angiogenesis was investigated in cell culture and the mouse oxygen-induced retinopathy model. Human retinal endothelial cells were cocultured with primary Müller cells transfected with Nrf2 small-interference RNA. Müller cell-specific Nrf2 knockout mice were subjected to oxygen-induced retinopathy. RNA-seq analysis of a Müller cell-specific RiboTag transcriptome was conducted in wild-type and Nrf2-deficient Müller cells.

Results: Silencing Nrf2 in primary Müller cells increased angiogenic activity in retinal endothelial cells. Müller cell-specific Nrf2 deficiency exacerbated pathological neovascularization in oxygen-induced retinopathy, associated with increased Müller cell gliosis and upregulation of retinal Tnfα (tumor necrosis factor alpha). Müller cell Nrf2 deficiency resulted in dysregulation of multiple genes involved in acute-phase response, inflammation, and angiogenesis, including increased expression of Lcn2 (lipocalin-2) and Fgf2, both of which promoted angiogenesis in human retinal endothelial cells. Blocking LCN2 with a neutralizing antibody attenuated pathological neovascularization and vaso-obliteration, suggesting LCN2 is a key mediator of aberrant angiogenic response in Müller cell-specific Nrf2 deficiency.

Conclusions: Nrf2 in Müller cells plays an integral protective role in modulating retinal angiogenesis and inflammatory responses in ischemic retinopathy. Nrf2 is an important regulator of Müller cell state in retinal ischemia and governs the Müller cell transcriptional program, including LCN2, a novel regulator of angiogenesis. This highlights pharmacological activation of Nrf2 as a therapeutic strategy for pathological neovascularization in ischemic retinopathy.

Background: BMPER (bone morphogenetic protein-binding endothelial regulator) is a secreted protein that is highly expressed in endothelial cells. It regulates the BMP (bone morphogenetic protein) pathway during vascular development and adulthood. Mutations in the BMP pathway are recognized as risk factors for pulmonary arterial hypertension group 1 pulmonary hypertension (PH). However, the roles of BMPER in pulmonary arterial hypertension remain unknown.

Methods: We assessed BMPER expression in Group 1 pulmonary arterial hypertension patient samples and examined its role in vascular remodeling using in vivo and in vitro approaches.

Results: BMPER level was elevated in pulmonary arterial hypertension lungs and significantly associated with pulmonary vascular resistance, but was not increased in patient plasma. Global and endothelial cell-specific depletion of BMPER in a mouse model of hypoxia-induced PH displayed attenuation in pulmonary artery smooth muscle cell proliferation, a hallmark of pulmonary vascular remodeling, and reduced right ventricular pressures. Conversely, adeno-associated virus-assisted BMPER overexpression targeted to the pulmonary endothelium led to the spontaneous development of PH. Mechanistically, BMPER promoted YAP (yes-associated protein 1) activation through the release of YAP sequestration by LRP1 (low-density lipoprotein receptor-related protein 1), a BMPER endocytic receptor, in the membrane of pulmonary artery smooth muscle cells. Moreover, the protective effect of BMPER depletion can be reversed by simultaneous depletion of LRP1 in mice with hypoxia-induced PH.

Conclusions: Collectively, these results implicate secreted BMPER as a discrete regulator for pulmonary vascular remodeling and suggest its inhibition as a new potential therapeutic strategy against PH.