Arteriosclerosis, Thrombosis, and Vascular Biology最新文献

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.

Background: Sickle cell disease (SCD) is a challenging genetic disorder characterized by hemolytic anemia, vaso-occlusive crises (VOC), and progressive organ damage. Despite its severity, effective treatments are limited. The recent withdrawal of promising therapies, such as the anti-P-selectin antibody Crizanlizumab and the hemoglobin polymerization inhibitor Voxelotor, highlights the urgent need for innovative approaches to alleviate vaso-occlusion and thromboinflammation.

Methods: In this study, we used advanced techniques, including intravital microscopy, laser speckle contrast imaging, and histological analysis, to examine the role of syk (spleen tyrosine kinase) in platelet and neutrophil recruitment, and blood perfusion in the lung, kidney, liver, and spleen of SCD mice.

Results: In the Berkeley SCD model, hemin-induced vaso-occlusion and impairment in pulmonary blood perfusion were independent of red cell congestion and fibrin deposition. Hypoperfusion was driven by adhesion of neutrophils and platelets in the microcirculation and exacerbated by pulmonary emboli. Hemin-induced cell adhesion and hypoperfusion were also observed in the renal microcirculation, whereas it was limited in the liver and spleen of SCD mice, suggesting that organ-specific mechanisms drive hypoperfusion and vaso-occlusion. To explore therapeutic options, we investigated the potential of Syk inhibition in improving blood perfusion and reducing thrombo-inflammation in different organs. Selective Syk inhibition, using BI-1002494, reduced cellular adhesion in the pulmonary and renal microvasculature, effectively restoring blood perfusion and reducing thrombo-inflammation. Low-dose Syk inhibitor was effective in reducing neutrophil adhesion and improving blood perfusion without inducing bleeding. Increasing the dose exacerbated hemin-induced bleeding in the lungs, likely due to off-target activity againt other kinases, including Src.

Conclusions: These findings underscore the critical role of Syk in platelet and neutrophil mediated-thrombo-inflammation and hypoperfusion in SCD, suggesting that Syk inhibition is a promising strategy to reduce organ-specific vaso-occlusion, improve renal and pulmonary perfusion, and reduce organ damage.

Background: Atherosclerosis progresses through endothelial dysfunction, vascular inflammation, endothelial-to-mesenchymal transition (EndMT), and plaque instability. While ANGPTL4 (angiopoietin-like 4) is known for its metabolic functions, its role in endothelial homeostasis remains unclear.

Methods: We investigated the protective effects of ANGPTL4 on endothelial inflammation, vascular integrity, and EndMT using Apoe^-/^- mice, human umbilical vein endothelial cells, human aortic endothelial cells, and induced pluripotent stem cell-derived endothelial cells. EndMT features were also evaluated in human atherosclerotic plaques. In patients with coronary artery disease, we analyzed plasma ANGPTL4 levels in relation to coronary microvascular dysfunction, as assessed by coronary flow reserve and the index of microcirculatory resistance.

Results: ANGPTL4 suppressed TNF-α (tumor necrosis factor alpha)-induced and IL-1β (interleukin-1 beta)-induced endothelial inflammation and preserved vascular barrier integrity in vitro and in vivo. It also inhibited TGF-β (transforming growth factor-β)-driven EndMT by restoring endothelial markers and suppressing mesenchymal marker expression. Mechanistically, ANGPTL4 attenuated TGF-β-Smad2 (suppressor of mothers against decapentaplegic 2) signaling and restored KLF2 (Krüppel-like factor 2) expression, which was essential for its anti-inflammatory and anti-EndMT effects. KLF2 knockdown abolished ANGPTL4-mediated endothelial protection, confirming its pivotal role in maintaining endothelial identity. In human atherosclerotic plaques, EndMT marker expression strongly correlated with plaque complexity, suggesting that EndMT exacerbates atherosclerosis progression. Plasma ANGPTL4 levels were significantly reduced in patients with coronary artery disease with coronary microvascular dysfunction and were positively correlated with coronary flow reserve, supporting its potential as a biomarker and preventive modulator of endothelial dysfunction.

Conclusions: These findings identify ANGPTL4 as a critical modulator of endothelial inflammation and EndMT via suppression of TGF-β-Smad2 signaling and restoration of KLF2. By preserving vascular integrity and promoting endothelial homeostasis, ANGPTL4 may serve as a preventive modulator in EndMT-driven vascular pathology and coronary microvascular dysfunction.

Background: Coronary artery disease (CAD) and cancer are 2 leading global causes of mortality, with shared modifiable risk factors, yet the genetic and molecular mechanisms underlying their comorbidity remain poorly understood.

Methods: We performed a genome-wide pleiotropy analysis to identify shared genetic mechanisms across CAD and 4 common cancers that share modifiable risk factors with CAD (breast, colorectal, lung, prostate).

Results: Using genome-wide pleiotropy and colocalization analysis, we identified 60 colocalized susceptibility loci shared by CAD and site-specific cancer, of which 43 are novel, including loci at TERT, MYO9B, and SREBF1. For 35 loci, the lead SNP (single-nucleotide polymorphism) exhibited opposing effects on CAD and cancer risk. Gene-set enrichment analysis revealed distinct enrichment patterns of same-direction and opposing-direction pleiotropic loci, including differential associations with blood pressure-related traits, blood cell traits, and waist circumference. By integrating transcriptomic and proteomic data in multitrait colocalization, 13 pleiotropic loci influenced CAD and cancer risk via differential gene or protein expression of neighboring genes, including CALCRL, ANGPTL4, and LAMC1, targets of approved or investigational medications. Phenome-wide association analysis in the UK Biobank identified 1955 associations (false discovery rate [FDR] P<0.05) of lead SNPs at multitrait colocalized loci with serum biomarkers and clinical measures, with apoA, HDL (high-density lipoprotein) cholesterol, and creatinine being associated with the largest number of lead SNPs.

Conclusions: Our findings highlight shared and opposing genetic loci between CAD and cancer and provide insight into molecular intermediates mediating joint disease risk. Importantly, they indicate potential drug repurposing opportunities for dual CAD and cancer prevention while highlighting possible adverse and divergent effects of existing medications across both conditions.

Recent advances in single-cell transcriptomics have provided significant insights into the pathophysiology of preeclampsia, uncovering cell-type-specific gene expression changes at the maternal-fetal interface. Key discoveries include dysregulated angiogenic factors, such as elevated sFlt-1 (soluble fms-like tyrosine kinase-1) and reduced PlGF (placental growth factor), predominantly in syncytiotrophoblasts, alongside inflammatory and stress-related signatures in stromal and immune cells. These findings reinforce the clinically observed concept of 2 distinct preeclampsia subtypes: a placenta-dominant form and a maternal cardiovascular-dominant form, each characterized by unique etiologies, clinical presentations, and therapeutic implications. Ongoing genomic research has the potential to identify novel biomarkers and therapeutic targets, paving the way for improved screening and management strategies for this multifaceted condition.

Background: Vascular calcification is very common in patients with chronic kidney disease and contributes to the increased risk of cardiovascular events. NAMPT (nicotinamide phosphoribosyltransferase), the rate-limiting enzyme in the salvage pathway of nicotinamide adenine dinucleotide, has been shown to exert an antiaging effect on vascular smooth muscle cells. However, whether NAMPT is involved in the regulation of vascular calcification remains unclear.

Methods: ELISA, immunofluorescence, and Western blot were used to detect NAMPT levels in human blood and tissues. Alizarin red staining, calcium content assay, and microcomputed tomography were used to investigate the role of NAMPT in vascular calcification. Gene expression analysis and coimmunoprecipitation were performed to elucidate the underlying mechanism.

Results: ELISA, immunofluorescence, and Western blot showed that NAMPT levels were increased in the blood of patients with chronic kidney disease and human calcified arterial tissues. Alizarin red staining and calcium content assay revealed that pharmacological inhibition or knockdown of NAMPT exacerbated vascular smooth muscle cell calcification, whereas overexpression of NAMPT reduced mineral deposition under osteogenic conditions. Similarly, ex vivo studies revealed that NAMPT inhibited calcification of rat and human arterial rings. Moreover, administration of NAMPT inhibitor FK866 promoted aortic calcification of chronic kidney disease rats, and smooth muscle cell-specific NAMPT knockout mice exhibited aggravated aortic calcification. Furthermore, pharmacological inhibition and knockdown of SIRT1 (sirtuin 1) abrogated the inhibitory effect of NAMPT on vascular calcification. In addition, smooth muscle cell-specific SIRT1 deficiency abrogated the protective effect of recombinant NAMPT on mouse aortic calcification. Coimmunoprecipitation and immunofluorescence assay further revealed that NAMPT inhibited the acetylation of NICD (Notch intracellular domain) and reduced the expression of HES1 (hairy and enhancer of split-1) in a SIRT1-dependent pathway.

Conclusions: Our study unveils that NAMPT could serve as a novel endogenous inhibitor of vascular calcification via modulation of SIRT1-mediated deacetylation of NICD.

Background: Approximately 50% of deep vein thrombosis (DVT) occurrences in the lower extremity proximal veins are associated with pulmonary embolism (PE). The progression of proximal DVT is critical in PE development, as reflected by thrombus composition. Magnetic resonance black-blood thrombus imaging can identify venous thrombus components by displaying thrombus signal intensity variations. This study investigated the association between thrombus signal intensity and PE in patients with proximal DVT.

Methods: A total of 126 patients with proximal DVT were recruited, and all underwent magnetic resonance black-blood thrombus imaging examination. The patients were divided into 2 groups: DVT-only and DVT with PE. The whole thrombus signal intensity ratio, proximal thrombus signal intensity ratio, distal thrombus signal intensity ratio, and thrombus volume were assessed. Histological analysis was performed to characterize the thrombus content. Logistic regression models were performed to evaluate the relationship between thrombus signal intensity and PE.

Results: Of the 126 eligible patients, 73 (58%) patients were in the DVT with PE group. Both proximal thrombus signal intensity ratio and whole thrombus signal intensity ratio were lower in the DVT with PE group compared with the DVT-only group (1.92±0.54 versus 1.31±0.42, P<0.001; 1.76±0.41 versus 1.62±0.36, P=0.034). The percentage of fibrin area (13.99±1.56% versus 7.51±1.25%, P=0.0087) and red blood cells area (49.65±18.8% versus 13.41±4.74%, P=0.0012) were higher in DVT with PE than DVT-only group. Univariate and multivariate logistic regression analysis showed that proximal thrombus signal intensity ratio remained statistically significant (odds ratio, 0.21 [95% CI, 0.12-0.39]; P<0.001).

Conclusions: The proximal thrombus signal intensity ratio of the thrombus was independently associated with acute PE in patients with proximal lower extremity DVT, suggesting that thrombus components may be important in PE occurrence. These findings could provide novel insights for understanding DVT evolution.

Preeclampsia is a multisystem vascular disorder characterized by new-onset hypertension and proteinuria after 20 weeks of gestation. Preeclampsia affects 2% to 5% of pregnancies and is a major contributor to maternal and perinatal morbidity and mortality resulting from aberrant vascular and immunologic responses. While the exact mechanisms of why preeclampsia arises remain unclear, our current understanding suggests that inadequate vascular adaptations are a contributing factor to the disease. In this review, we focus on how immune system changes affect the onset and pathogenesis of preeclampsia, specifically in the context of placental vascular development and maternal cardiovascular dysfunction. We also discuss the potential direct link in preeclampsia between immune cells, inflammation, and how they impact placental vascular remodeling and maternal cardiac dysfunction.