Endothelial Activation Research Articles

ABO blood groups and increased risk for the development of vascular involvement in Behçet's disease.

Inflammatory endothelial activation is a prominent feature of vascular involvement in Behçet's disease (BD), which is usually accompanied by a thrombotic tendency. Recent studies suggest an association between ABO blood groups and thrombotic vascular disease in those carrying non-O (A, B, and AB) groups. This study aimed to analyse the contribution of ABO blood groups to the vascular involvement in BD. In this retrospective study, BD patients with available ABO blood group data and meeting the ISG criteria were included in the study. The presence of vascular involvement, its clinical characteristics, and the data about other manifestations were recorded from the patient charts. This study was conducted in 411 patients; 143 (34.8%) were carrying O and 268 (65.2%) were carrying non-O groups. The vascular involvement was significantly more frequent and the risk for overall vascular and venous events was up to 2-fold higher in the patients with non-O groups. After adjustments for age, sex, and comorbidities, the risk for arterial disease was also found to be increased in association with non-O groups. ABO blood groups were shown to be independent risk factors for vascular BD by multiple regression models based on known predisposing factors. Compared with other non-O blood groups, the patients carrying blood group B had a higher risk for vascular events. The results of this preliminary study show the potential contribution of ABO blood groups to the vascular-BD phenotype and suggest an increased risk for vascular BD in association with non-O blood groups.

Soluble Urokinase-Type Plasminogen Activator Receptor (suPAR), Growth Differentiation Factor-15 (GDF-15), and Soluble C5b-9 (sC5b-9) Levels Are Significantly Associated with Endothelial Injury Indices in CAR-T Cell Recipients

Endothelial injury indices, such as Endothelial Activation and Stress Index (EASIX), modified EASIX (m-EASIX), and simplified EASIX (s-EASIX) scores, have been previously associated with chimeric antigen receptor-T (CAR-T) cell immunotherapy complications. Soluble urokinase-type plasminogen activator receptor (suPAR), growth differentiation factor-15 (GDF-15), and soluble C5b-9 (sC5b-9) have been described as markers of endothelial injury post-hematopoietic stem cell transplantation. In the current study, we examined whether suPAR, GDF-15, and sC5b-9 levels were associated with endothelial injury indices in adult CAR-T cell recipients. The levels of these markers were measured in patients before CAR-T cell infusion and in healthy individuals with immunoenzymatic methods. We studied 45 CAR-T cell recipients and 20 healthy individuals as the control group. SuPAR, GDF-15, and sC5b-9 levels were significantly higher in the patients’ group compared to the healthy control group (p < 0.001, in all comparisons). SuPAR levels at baseline were associated with the m-EASIX scores calculated at the same time point (p = 0.020), while suPAR and GDF-15 concentrations were correlated with EASIX scores at day 14 post-infusion (p < 0.001 in both comparisons). Moreover, sC5b-9 levels were correlated with the s-EASIX scores at infusion (p = 0.008) and the EASIX scores at day 14 (p = 0.005). In our study, sC5b9, suPAR, and GDF-15 levels were found to reflect endothelial injury in CAR-T cell recipients.

IPSC-derived megakaryocytes and platelets accelerate wound healing and angiogenesis

BackgroundPlatelet-rich plasma (PRP), which is prepared by concentrating platelets in autologous blood, shows efficacy in chronic skin wounds via multiple growth factors. However, it exhibits heterogeneity across patients, leading to unstable therapeutic efficacy. Human induced pluripotent stem cell (iPSC)-derived megakaryocytes and platelets (iMPs) are capable of providing a stable supply, holding promise as materials for novel platelet concentrate-based therapies. In this context, we evaluated the effect of iMPs on wound healing and validated lyophilization for clinical applications.MethodsThe growth factors released by activated iMPs were measured. The effect of the administration of iMPs on human fibroblasts and human umbilical vein endothelial cells (HUVECs) was investigated in vitro. iMPs were applied to dorsal skin defects of diabetic mice to assess the wound closure rate and quantify collagen deposition and angiogenesis. Following the storage of freeze-dried iMPs (FD-iMPs) for three months, the stability of growth factors and their efficacy in animal models were determined.ResultMultiple growth factors that promote wound healing were detected in activated iMPs. iMPs specifically released FGF2 and exhibited a superior enhancement of HUVEC proliferation compared to PRP. Moreover, an RNA-seq analysis revealed that iMPs induce polarization to stalk cells and enhance ANGPTL4 gene expression in HUVECs. Animal studies demonstrated that iMPs promoted wound closure and angiogenesis in chronic wounds caused by diabetes. We also confirmed the long-term stability of growth factors in FD-iMPs and their comparable effects to those of original iMPs in the animal model.ConclusionOur study demonstrates that iMPs promote angiogenesis and wound healing through the activation of vascular endothelial cells. iMPs exhibited more effectiveness than PRP, an effect attributed to the exclusive presence of specific factors including FGF2. Lyophilization enabled the long-term maintenance of the composition of the growth factors and efficacy of the iMPs, therefore contributing to stable supply for clinical application. These findings suggest that iMPs provide a novel treatment for chronic wounds.

Yiqihuoxue decoction (GSC) inhibits mitochondrial fission through the AMPK pathway to ameliorate EPCs senescence and optimize vascular aging transplantation regimens

BackgroundDuring the aging process, the number and functional activity of endothelial progenitor cells (EPCs) are impaired, leading to the unsatisfactory efficacy of transplantation. Previous studies demonstrated that Yiqihuoxue decoction (Ginseng-Sanqi-Chuanxiong, GSC) exerts anti-vascular aging effects. The purpose of this study is to evaluated the effects of GSC on D-galactose (D-gal)induced senescence and the underlying mechanisms.MethodsThe levels of cellular senescence-related markers P16, P21, P53, AMPK and p-AMPK were detected by Western blot analysis (WB). SA-β-gal staining was used to evaluate cell senescence. EPCs function was measured by CCK-8, Transwell cell migration and cell adhesion assay. The morphological changes of mitochondria were detected by confocal microscopy. The protein and mRNA expression of mitochondrial fusion fission Drp1, Mff, Fis1, Mfn1, Mfn2 and Opa1 in mitochondria were detect using WB and RT–qPCR. Mitochondrial membrane potential, mtROS and ATP of EPCs were measured using IF. H&E staining was used to observe the pathological changes and IMT of the aorta. The expressions of AGEs, MMP-2 and VEGF in aorta were measured using Immunohistochemical (IHC). The levels of SOD, MDA, NO and ET-1 in serum were detected by SOD, MDA and NO kits.ResultsIn vitro, GSC ameliorated the senescence of EPCs induced by D-gal and reduced the expression of P16, P21 and P53. The mitochondrial morphology of EPCs was restored, the expression of mitochondrial Drp1, Mff and Fis1 protein was decreased, the levels of mtROS and ATP were decreased, and mitochondrial function was improved. Meanwhile, the expression of AMPK and p-AMPK increased. The improvement effects of GSC on aging and mitochondrial morphology and function were were hindered after adding AMPK inhibitor. In vivo, GSC improved EPCs efficiency, ameliorated aortic structural disorder and decreased IMT in aging mice. The serum SOD level increased and MDA level decreased, indicating the improvement of antioxidant capacity. Increased NO content and ET-1 content suggested improvement of vascular endothelial function. The changes observed in SOD and MMP-2 suggested a reduction in vascular stiffness and the degree of vascular damage. The decreased expression of P21 and P53 indicates the delay of vascular senescence.

Immunoexpression of CD34, CD68 and CD3 in Cadmium-Induced Liver Damage and Protective Effectiveness of Bee Bread (Perga)

Cadmium (Cd) is one of the potent environmental toxicants that causes oxidative stress in many organs of the body, including the liver. Perga (bee bread) is used for apitherapeutic purposes due to its medicinal properties. This study was conducted to investigate the effectiveness of perga on endothelial damage and inflammatory cell activation in the liver as a result of exposure to Cd. For this purpose, 32 male Wistar rats (8 rats/group) were randomly divided into 4 groups, as the control, perga (0.5 g/kg of perga), Cd (5 mg/kg of CdCl2), and Cd + perga (0.5 g/kg of perga + 5 mg/kg of CdCl2) groups. Daily intragastric Cd and/or perga was administered for 4 weeks. At the end of the study, the rats were euthanized and liver tissue sections were taken and stained with hematoxylin-eosin and Masson’s Trichrome. Immunohistochemically, the reactivity of the liver sinusoidal endothelium was determined using CD34, the reactivity of the Kupffer cells was determined using CD68, and the levels of T-lymphocyte cells were determined using CD3 antibodies. Exposure to Cd caused significant histological changes in the liver. Immunohistochemically, exposure to Cd caused an increase in the expressions of CD34, CD68, and CD3. On the other hand, the cotreatment of Cd and perga caused partial improvement in some histopathological changes. Compared to the Cd group, there was a decrease in CD34 and CD68 positivity in the Cd + perga group, while no significant difference was detected in the number of CD3-positive cells between the groups. The results revealed that the histopathological changes and inflammation in the rat liver could partially improve with perga supplementation.

Identification of potential microRNAs involved in pathogenesis of venous thromboembolism (VTE): A meta analysis

ObjectiveMicroRNAs (MiRNAs) are master regulators of gene expression and have been suggested as potential diagnostic and therapeutic biomarkers in variety of complex diseases. Venous thromboembolism is a major cause of morbidity and mortality worldwide. Several miRNA expression studies have been conducted to identify miRNAs linked to VTE prognosis. These studies reveal that various miRNAs are significantly up-regulated and down-regulated in VTE patients in comparison to healthy controls. Present meta-analysis deliberate findings of such studies to identify most potential miRNA targets associated with VTE. MethodologyComprehensive literature review on Pubmed was conducted. Present analysis assessed 20 research article out of a total of 383 articles screened, based on inclusion and exclusion criteria. The up-regulated and down-regulated miRNAs obtained from selected research articles were subjected to meta-analysis. The differentially expressed miRNAs so obtained and were used for further bioinformatic analysis, including gene ontology and pathway analysis of their target genes, to study their potential involvement in VTE pathogenesis. ResultsTwenty articles selected for meta-analysis included a total of 808 patients. These included 26 up-regulated miRNAs and 11 down-regulated miRNAs. The meta-analysis based on Odds ratio suggested that one up-regulated miRNA (hsa-miR-1233-3p) and two down-regulated miRNAs (hsa-miR-103a-3p and hsa-miR-200c) returned significantly higher Odds compared to other miRNAs. Further bioinformatics analysis of their target genes revealed that these miRNAs target a large number of genes involved in cell adhesion, cell migration, endothelial activation and inflammation genes. ConclusionsThree miRNAs, viz.; hsa-miR-1233-3p, hsa-miR-103a-3p and hsa-miR-200c may play a crucial role in VTE pathogenesis and has potential to serve as reliable diagnostic or therapeutic biomarkers for VTE.

High-Density Lipoprotein Mimetic Peptide 4F Reduces Toxic Amyloid-Beta Exposure to the Blood-Brain Barrier Endothelium in Alzheimer's Disease Transgenic Mice.

Aβ accumulation in the blood-brain barrier (BBB) endothelium, which lines the cerebrovascular lumen, is a significant contributor to cerebrovascular dysfunction in Alzheimer's disease (AD). Reduced high-density lipoprotein (HDL) levels are associated with increased AD risk, and the HDL mimetic peptide 4F has been developed as a promising therapeutic agent to improve cerebrovascular health in AD. In this study, we evaluated the impact of 4F on 125I-Aβ42 blood-to-brain distribution using dynamic SPECT/CT imaging in both wild-type and APP/PS1 transgenic mice. Graphical analysis of the imaging data demonstrated that 4F significantly reduced the blood-to-brain influx rate in wild-type mice and the distribution of 125I-Aβ42 in the BBB endothelium in APP/PS1 mice. To elucidate the molecular mechanisms underlying the effect of 4F, we evaluated its impact on the p38 pathway and its role in mediating Aβ42 trafficking in human BBB endothelial cell monolayers. Treatment with 4F significantly decreased Aβ42 induced p38 activation in BBB endothelial cells. Furthermore, inhibition of p38 kinase significantly reduced endothelial accumulation of fluorescence-labeled Aβ42 and luminal-to-abluminal permeability across the cell monolayer. While our previous publication has hinted at the potential of 4F to reduce Aβ accumulation in the brain parenchyma, the current findings demonstrated the protective effect of 4F in reducing Aβ42 accumulation in the BBB endothelium of AD transgenic mice. These findings revealed the impact of a clinically tested agent, the HDL mimetic peptide 4F, on Aβ exposure to the BBB endothelium and offer novel mechanistic insights into potential therapeutic strategies to treat cerebrovascular dysfunction in AD.

Influence of polylactide wound dressings with tannic acid on serum concentration of markers of angiogenesis, endothelial cell alteration and activation in white rats during healing of experimental full-thickness skin defect

Influence of polylactide wound dressings with tannic acid on serum concentration of markers of angiogenesis, endothelial cell alteration and activation in white rats during healing of experimental full-thickness skin defect

Targeting KLF2 as a Novel Therapy for Glomerular Endothelial Cell Injury in Diabetic Kidney Disease.

DKD is a microvascular disease, and glomerular endothelial cell injury is a key pathological event in DKD development. Through unbiased screening of glomerular transcriptomes, we previously identified KLF2 as a highly regulated gene in diabetic kidneys. KLF2 exhibits protective effects in endothelial cells by inhibiting inflammation, thrombotic activation, and angiogenesis, all of which are protective for cardiovascular disease. We previously demonstrated that endothelial cell-specific ablation of Klf2 exacerbated diabetes-induced glomerular endothelial cell injury and DKD in mice. Therefore in this study, we sought to assess the therapeutic potential of KLF2 activation in murine models of DKD. We first examined the effects of endothelial cell-specific inducible overexpression of KLF2 (KLF2ov) in streptozotocin-induced diabetic mice. We developed small molecule KLF2 activators and tested whether increased KLF2 activity could impede DKD progression in type 2 diabetic db/db and BTBR ob/ob mice. Diabetic KLF2ov mice had attenuated albuminuria, glomerular endothelial cell injury, and diabetic glomerulopathy compared to control diabetic mice. Novel KLF2 activator, compound 6 (C-6) effectively induced downstream Nos3 expression and suppressed NF-kB activation in glomerular endothelial cells. The administration of C-6 improved albuminuria and glomerulopathy in db/db and BTBR ob/ob mice, which was associated with improved glomerular endothelial cell and podocyte injury. These results validate KLF2 as a potential drug target and KLF2 activators such as C-6 as a novel therapy for DKD.

The role of metabolic disorders in the development of atherosclerosis.

Atherosclerosis is a major risk factor for cardiovascular disease (CVD), which is the leading cause of death worldwide. Atherosclerosis is initiated by endothelial activation, followed by a cascade of events (accumulation of lipids, fibrous elements, and calcification) triggering vasoconstriction and activation of inflammatory pathways. This review focuses on the various stages in the development of atherosclerosis, ranging from endothelial dysfunction to plaque rupture. In addition, disorders of lipid, glucose and amino acid metabolism in atherosclerosis are considered here. The key pathological stages of metabolism disruption and their role in atherosclerosis are considered in detail which may be helpful for the more better understanding of atherosclerosis pathogenesis. Finally, some therapeutic approaches aimed at modulating lipid metabolism will also be presented which show the therapeutic targets (enzymes and transport proteins) which modulation can prevent further deterioration of patients symptoms.

A Novel Preclinical Murine Model of Systemic Lupus Erythematosus-Like Cardiovascular Disease.

Systemic lupus erythematosus (SLE) affects nine women to every man worldwide, and these patients are at greater risk for cardiovascular disease (CVD) morbidity and mortality. Clinical studies have demonstrated that patients with SLE are more likely to develop CVD, including cardiac and vascular dysfunction. Although many preclinical models of SLE are available, including treatment with Toll-like receptor (TLR) 7/8 agonists, a consistent preclinical model of SLE-like CVD with systemic, cardiac, renal, and cerebral endothelial activation and cardiac dysfunction has yet to be described. Here, we hypothesize that acceleration of SLE with the TLR7/8 agonist resiquimod (R848) will promote cardiac and endothelial activation with subsequent end-stage organ damage in the SLE-prone B6.Nba2 mouse model. Female and male SLE-prone B6.Nba2 mice were treated with R848 or acetone, administered topically twice weekly over a four-week period, to accelerate the development of SLE-like pathophysiology. Echocardiography was performed at baseline, 4 weeks, and 16 weeks. At 16 weeks, tissues were harvested, weighed, and analyzed by histology, immunofluorescence, real-time quantitative polymerase chain reaction, and enzyme-linked immunosorbent assays. We found that female R848-treated mice had increased serum anti-Smith and immunoglobulin G complex deposition in the kidney, heart, and brain consistent with SLE-like etiology. Tissue analysis revealed significant enlargement of the spleen in both female and male R848-treated mice, with only cardiac and renal enlargement in females compared to their respective controls. Echocardiographic imaging revealed left ventricular wall thickening by 4 weeks that was followed by a progressive increase in left ventricular internal diameters and subsequent decrease in ejection fraction over the 16-week time course in female mice. We found that circulating levels of soluble vascular adhesion molecule-1 and soluble intracellular adhesion molecule-1 were increased in both female and male R848-treated mice, whereas cardiac and renal fibrosis were significantly increased in only female R848-treated mice. Our data demonstrate that R848 treatment of SLE-prone B6.Nba2 mice is a novel preclinical model to study the sex-dependent pathophysiologic mechanisms of SLE-like CVD.

Noncaloric monosaccharides induce excessive sprouting angiogenesis in zebrafish via foxo1a-marcksl1a signal.

Artificially sweetened beverages containing noncaloric monosaccharides were suggested as healthier alternatives to sugar-sweetened beverages. Nevertheless, the potential detrimental effects of these noncaloric monosaccharides on blood vessel function remain inadequately understood. We have established a zebrafish model that exhibits significant excessive angiogenesis induced by high glucose, resembling the hyperangiogenic characteristics observed in proliferative diabetic retinopathy (PDR). Utilizing this model, we observed that glucose and noncaloric monosaccharides could induce excessive formation of blood vessels, especially intersegmental vessels (ISVs). The excessively branched vessels were observed to be formed by ectopic activation of quiescent endothelial cells (ECs) into tip cells. Single-cell transcriptomic sequencing analysis of the ECs in the embryos exposed to high glucose revealed an augmented ratio of capillary ECs, proliferating ECs, and a series of upregulated proangiogenic genes. Further analysis and experiments validated that reduced foxo1a mediated the excessive angiogenesis induced by monosaccharides via upregulating the expression of marcksl1a. This study has provided new evidence showing the negative effects of noncaloric monosaccharides on the vascular system and the underlying mechanisms.

Platelet integrin αIIbβ3 plays a key role in a venous thrombogenesis mouse model

Venous thrombosis (VT) is a common vascular disease associated with reduced survival and a high recurrence rate. VT is initiated by the accumulation of platelets and neutrophils at sites of endothelial cell activation. A role for platelet αIIbβ3 in VT is not established, a task complicated by the increased bleeding risk caused by partial agonists such as tirofiban. Here, we show that m-tirofiban, a modified version of tirofiban, does not agonize αIIbβ3 based on lack of neoepitope expression and the cryo-EM structure of m-tirofiban/full-length αIIbβ3 complex. m-tirofiban abolishes agonist-induced platelet aggregation while preserving clot retraction ex vivo and, unlike tirofiban, it suppresses venous thrombogenesis in a mouse model without increasing bleeding. These findings establish a key role for αIIbβ3 in VT initiation and suggest that m-tirofiban and compounds with a similar structurally-defined mechanism of action merit consideration as potential thromboprophylaxis agents in patients at high risk for VT and hemorrhage.

SCAR-6 elncRNA locus epigenetically regulates PROZ and modulates coagulation and vascular function.

In this study, we characterize a novel lncRNA-producing gene locus that we name Syntenic Cardiovascular Conserved Region-Associated lncRNA-6 (scar-6) and functionally validate its role in coagulation and cardiovascular function. A 12-bp deletion of the scar-6 locus in zebrafish (scar-6gib007Δ12/Δ12) results in cranial hemorrhage and vascular permeability. Overexpression, knockdown and rescue with the scar-6 lncRNA modulates hemostasis in zebrafish. Molecular investigation reveals that the scar-6 lncRNA acts as an enhancer lncRNA (elncRNA), and controls the expression of prozb, an inhibitor of factor Xa, through an enhancer element in the scar-6 locus. The scar-6 locus suppresses loop formation between prozb and scar-6 sequences, which might be facilitated by the methylation of CpG islands via the prdm14-PRC2 complex whose binding to the locus might be stabilized by the scar-6 elncRNA transcript. Binding of prdm14 to the scar-6 locus is impaired in scar-6gib007Δ12/Δ12 zebrafish. Finally, activation of the PAR2 receptor in scar-6gib007Δ12/Δ12 zebrafish triggers NF-κB-mediated endothelial cell activation, leading to vascular dysfunction and hemorrhage. We present evidence that the scar-6 locus plays a role in regulating the expression of the coagulation cascade gene prozb and maintains vascular homeostasis.

The Angiopoietin-Tie-2 Axis in Children and Young Adults with Dengue Virus Infection in the Philippines.

Dengue virus (DENV) infection is associated with plasma leakage, which may progress to shock. The angiopoietin (Ang)-tyrosine kinase with immunoglobulin and epidermal growth factor homology domain 2 (Tie-2) axis regulates endothelial permeability. We examined the clinical utility of Ang-1, Ang-2, and the Ang-2-to-Ang-1 ratio for prediction of progression to severe DENV in a prospective cohort study of children and young adults (age 1 to <26 years) with DENV infection. Ang-1, Ang-2, Tie-2 were measured at presentation to an outpatient clinic in the Philippines from stored plasma by multiplex Luminex® assay. Patients were followed prospectively to document the clinical course (hospitalization, length of stay, intravenous fluid resuscitation, and transfer to a higher level facility). We included 244 patients (median age 9 years, 40% female). At presentation, 63 patients (26%) had uncomplicated dengue, 179 (73%) had dengue with warning signs, and 2 (0.82%) had severe dengue. One hundred eighty-one patients (74%) were hospitalized. Ang-1 levels were lower and Ang-2 higher in patients who required hospitalization. Ang-2-to-Ang-1 ratio >1 was associated with a relative risk of hospitalization of 1.20 (95% CI: 1.03-1.36, P = 0.016). A higher Ang-2-to-Ang-1 ratio was associated with longer length of hospital stay, higher frequency of transfer to a higher level facility, larger intravenous fluid requirement, hemoconcentration, and thrombocytopenia. Angiopoietin-2 was correlated with procalcitonin (Kendall's τ = 0.17, P = 0.00012), a marker of systemic inflammation, as well as soluble vascular cell adhesion molecule-1 (τ = 0.22, P <0.0001) and Endoglin (τ = 0.14, P = 0.0017), markers of endothelial activation. In conclusion, altered Ang-2-to-Ang-1 ratio can be detected early in the course of DENV infection and predicts clinically meaningful events (hospitalization, length of stay, and fluid resuscitation).

Safety and efficacy of G-CSF after allogeneic hematopoietic cell transplantation using post-transplant cyclophosphamide: clinical and in vitro examination of endothelial activation.

Since 2021 the use of G-CSF was implemented in allo-HCT with PTCY-based prophylaxis with the aim of shortening the aplastic phase and reducing infectious complications. This study investigates the effectiveness of this change in protocol performed at our institution. One-hundred forty-six adults undergoing allo-HCT with PTCY-based prophylaxis were included, and among them, 58 (40%) received G-CSF. The median of days to neutrophil engraftment was shorter in the G-CSF group (15 vs. 20 days, p < 0.001). Patients receiving G-CSF had a lower incidence of day +30 bacterial bloodstream infections (BSI) than the rest (20.7% vs. 47.7%, p < 0.001). GVHD, SOS, and TA-TMA incidences were comparable between groups, and using G-CSF did not impact on survival. Endothelial activation was investigated using EASIX and by the measurement of soluble biomarkers in cryopreserved plasma samples obtained on days 0, +7, +14 and +21 of 39 consecutive patients (10 received G-CSF) included in the study. EASIX, VWF:Ag, sVCAM-1, sTNFRI, ST2, REG3α, TM and NETs medians values were comparable in patients receiving G-CSF and those who did not. Compared with allo-HCT performed without G-CSF, the addition of G-CSF to PTCY-based allo-HCT accelerated neutrophil engraftment contributing on decreasing BSI incidence, and without inducing additional endothelial activation.

Endothelial PHD2 deficiency induces apoptosis resistance and inflammation via AKT activation and AIP1 loss independent of HIF2α.

In hypoxic and pseudohypoxic rodent models of pulmonary hypertension (PH), hypoxia-inducible factor (HIF) inhibition attenuates disease initiation. However, HIF activation alone, due to genetic alterations or use of inhibitors of prolyl hydroxylase domain (PHD) enzymes, has not been definitively shown to cause PH in humans, indicating the involvement of other mechanisms. Given the association between endothelial cell dysfunction and PH, the effects of pseudohypoxia and its underlying pathways were investigated in primary human lung endothelial cells. PHD2 silencing or inhibition, while activating HIF2α, induced apoptosis-resistance and IFN/STAT activation in endothelial cells, independent of HIF signaling. Mechanistically, PHD2 deficiency activated AKT and ERK, inhibited JNK, and reduced AIP1 (ASK1-interacting protein 1), all independent of HIF2α. Like PHD2, AIP1 silencing affected these same kinase pathways and produced a similar dysfunctional endothelial cell phenotype, which was partially reversed by AKT inhibition. Consistent with these in vitro findings, AIP1 protein levels in lung endothelial cells were decreased in Tie2-Cre/Phd2 knockout mice compared with wild-type controls. Lung vascular endothelial cells from patients with pulmonary arterial hypertension (PAH) showed IFN/STAT activation. Lung tissue from both SU5416/hypoxia PAH rats and patients with PAH all showed AKT activation and dysregulated AIP1 expression. In conclusion, PHD2 deficiency in lung vascular endothelial cells drives an apoptosis-resistant and inflammatory phenotype, mediated by AKT activation and AIP1 loss independent of HIF signaling. Targeting these pathways, including PHD2, AKT, and AIP1, holds the potential for developing new treatments for endothelial dysfunction in PH.NEW & NOTEWORTHY HIF activation alone does not conclusively lead to human PH, suggesting that HIF-independent signaling may also contribute to hypoxia-induced PH. This study demonstrated that PHD2 silencing-induced pseudohypoxia in human lung endothelial cells suppresses apoptosis and activates STAT, effects that persist despite HIF2α inhibition or knockdown and are attributed to AKT and ERK activation, JNK inhibition, and AIP1 loss. These findings align with observations in lung endothelial cells and tissues from PAH rodent models and patients.

The Role of Cardio-Renal Inflammation in Deciding the Fate of the Arteriovenous Fistula in Haemodialysis Therapy.

Vascular access is an indispensable component of haemodialysis therapy for end-stage kidney disease patients. The arteriovenous fistula (AVF) is most common, but importantly, two-year failure rates are greater than fifty percent. AVF failure can occur due to a lack of suitable vascular remodelling, and inappropriate inflammation preventing maturation, or alternatively neointimal hyperplasia and vascular stenosis preventing long-term use. A comprehensive mechanistic understanding of these processes is still lacking, but recent studies highlight an essential role for inflammation from uraemia and the AVF itself. Inflammation affects each cell in the cascade of AVF failure, the endothelium, the infiltrating immune cells, and the vascular smooth muscle cells. This review examines the role of inflammation in each cell step by step and the influence on AVF failure. Inflammation resulting in AVF failure occurs initially via changes in endothelial cell activation, permeability, and vasoprotective chemokine secretion. Resultingly, immune cells can extravasate into the subendothelial space to release inflammatory cytokines and cause other deleterious changes to the microenvironment. Finally, all these changes modify vascular smooth muscle cell function, resulting in excessive and unchecked hyperplasia and proliferation, eventually leading to stenosis and the failure of the AVF. Finally, the emerging therapeutic options based off these findings are discussed, including mesenchymal stem cells, small-molecule inhibitors, and far-infrared therapies. Recent years have clearly demonstrated a vital role for inflammation in deciding the fate of the AVF, and future works must be centred on this to develop therapies for a hitherto unacceptably underserved patient population.

Arterial function is preserved in successfully treated patients with psoriasis vulgaris.

Endothelial dysfunction is an early precursor of atherosclerosis and is common in patients with psoriasis, presumably primarily due to psoriasis-related inflammation. We investigated endothelial function, arterial stiffness, and circulating markers of endothelial activation in young patients with psoriasis vulgaris of varying severity, all of whom were effectively treated achieving PASI 90. We conducted a cross-sectional study of 80 patients (54 men/26 women, 30-45 years) who were effectively treated with topical therapy, methotrexate, adalimumab, secukinumab or guselkumab, and 20 healthy controls. Endothelial dysfunction was measured by flow-mediated dilation and arterial stiffness was measured by pulse wave velocity and common carotid artery stiffness. The following circulating biomarkers of endothelial activation were measured: ICAM-1, VCAM-1, E- and P-selectin, GDF-15, and TRAIL. Endothelial function and arterial stiffness parameters did not differ between patients with effectively treated psoriasis and the control group. Circulating endothelial activation biomarkers did not show relevant differences between the groups of effectively treated patients or controls. Although cardiovascular disease is the leading cause of morbidity and mortality in patients with psoriasis, effective antipsoriatic treatment appears to slow the progression of atherosclerosis, even when there are cardiovascular risk factors, such as smoking or obesity. This may suggest that antipsoriatic treatment exerts a cardioprotective effect. Our results suggest that early and effective treatment of varying-severity psoriasis vulgaris in young patients appears to prevent arterial dysfunction related to psoriasis and consequent cardiovascular risk.The study is registered at http://clinicaltrials.gov (identifier: NCT05957120).

Dietary protein in a challenge meal does not alleviate postprandial impairments in vascular endothelial function in healthy older adults with cardiometabolic risk: a randomized crossover-controlled trial

BackgroundPostprandial vascular endothelial dysfunction is an early marker of atherosclerosis. Meal protein has been reported to reduce endothelial dysfunction in adults and the effect could be mediated by the amino acid content. ObjectiveThis trial aims to assess the effect of a specifically designed plant protein blend that contains high leucine, arginine and cysteine on postprandial endothelial function in the elderly. MethodsIn a randomized, double-blind, 3-period crossover (2-wk washout), controlled trial, we compared the vascular effects of 3 high-saturated-fat high-sucrose (HFHS) meals based on either our specific plant-protein blend, milk protein, or without added protein. The trial was conducted on 29 healthy adults >65y presenting at least 2 cardiometabolic risk factors. Postprandial vascular function was evaluated at fasting, 3 hours, and 5 hours postprandially, using brachial flow-mediated dilation (FMD), hand microvascular reactivity (by Flowmetry Laser Doppler, FLD), and finger reactive hyperemia index (using Peripheral Arterial Tonometry, RHI). Immune cells count and gene expression in peripheral blood mononuclear cells (PBMC) was also assessed postprandially. Data were analyzed using mixed linear models with repeated measurements on participants for meal composition and time of sampling. This trial was registered at clinicaltrials.gov as NCT04923555. ResultsFMD iAUC decreased after meals (time effect P<0.01), with no significant differences between meals. RHI also decreased with time (P<0.01). PBMC count and MCP1, IL-1b, IL-6 expression increased after meals showing postprandial endothelial activation (P<0.05). Overall, meal composition had no effect on any of the postprandial changes (Ps>0.10). ConclusionsIn healthy adults over 65 years presenting cardiometabolic risk, adding protein to an HFHS challenge meal does not mitigate postprandial impairments in vascular endothelial function and inflammatory activation. Further studies are needed to explore the potential differences with younger adults.