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Glioblastoma is a highly aggressive neoplasm and the most common primary malignant brain tumor. Endothelial tissue plays a critical role in glioblastoma growth and progression, facilitating angiogenesis, cellular communication, and tumorigenesis. In this review, we present an up-to-date and comprehensive summary of the role of endothelial cells in glioblastomas, along with an overview of recent developments in glioblastoma therapies and tumor endothelial marker identification.

AIMS: Pulmonary hypertension (PH) is a pulmonary vascular disease characterized by a high mortality rate. Pulmonary arterial endothelium cells (PAECs) serve as a primary sensor of various environmental cues, such as shear stress and hypoxia, but PAEC dysfunction may trigger vascular remodelling during the onset of PH. This study aimed to illustrate the role of Sirtuin 7 (SIRT7) in endothelial dysfunction during PH and explore the potential therapeutic strategy for PH. METHODS AND RESULTS: SIRT7 levels were measured in human and murine experimental PH samples. Bioinformatic analysis, immunoprecipitation, and deacetylation assay were used to identify the association between SIRT7 and Krüpple-like factor 4 (KLF4), a key transcription factor essential for endothelial cell (EC) homeostasis. Sugen5416 + hypoxia (SuHx)-induced PH mouse models and cell cultures were used for the study of the therapeutic effect of SIRT7 for PH. SIRT7 level was significantly reduced in lung tissues and PAECs from PH patients and the SuHx-induced PH mouse model as compared with healthy controls. Pulmonary endothelium-specific depletion of Sirt7 increased right ventricular systolic pressure and exacerbated right ventricular hypertrophy in the SuHx-induced PH model. At the molecular level, we identified KLF4 as a downstream target of SIRT7, which deacetylated KLF4 at K228 and inhibited the ubiquitination-proteasome degradation. Thus, the SIRT7/KLF4 axis maintained PAEC homeostasis by regulating proliferation, migration, and tube formation. PAEC dysfunction was reversed by adeno-associated virus type 1 vector-mediated endothelial overexpression of Sirt7 or supplementation with nicotinamide adenine dinucleotide (NAD)+ intermediate nicotinamide riboside which activated Sirt7; both approaches successfully reversed PH phenotypes. CONCLUSION: The SIRT7/KLF4 axis ensures PAEC homeostasis, and pulmonary endothelium-specific SIRT7 targeting might constitute a PH therapeutic strategy.

Exercise promotes pulsatile shear stress in the arterial circulation and ameliorates cardiometabolic diseases. However, exercise-mediated metabolic transducers for vascular protection remain under-investigated. Untargeted metabolomic analysis demonstrated that wild-type mice undergoing voluntary wheel running exercise expressed increased endothelial stearoyl-CoA desaturase 1 (SCD1) that catalyzes anti-inflammatory lipid metabolites, namely, oleic (OA) and palmitoleic acids (PA), to mitigate NF-κB-mediated inflammatory responses. In silico analysis revealed that exercise augmented time-averaged wall shear stress but mitigated flow recirculation and oscillatory shear index in the lesser curvature of the mouse aortic arch. Following exercise, endothelial Scd1-deleted mice (Ldlr-/- Scd1EC-/-) on high-fat diet developed persistent VCAM1-positive endothelium in the lesser curvature and the descending aorta, whereas SCD1 overexpression via adenovirus transfection mitigated endoplasmic reticulum stress and inflammatory biomarkers. Single-cell transcriptomics of the aorta identified Scd1-positive and Vcam1-negative endothelial subclusters interacting with other candidate genes. Thus, exercise mitigates flow recirculation and activates endothelial SCD1 to catalyze OA and PA for vascular endothelial protection.

Statin therapy is a cornerstone in the treatment of systemic vascular diseases. However, statins have failed to translate as therapeutics for pulmonary vascular disease. Early pulmonary vascular disease in the setting of congenital heart disease (CHD) is characterized by endothelial dysfunction, which precedes the more advanced stages of vascular remodeling. These features make CHD an ideal cohort in which to re-evaluate the potential pulmonary vascular benefits of statins, with a focus on endothelial biology. However, it is critical that the full gamut of the pleiotropic effects of statins in the endothelium are uncovered. The purpose of this investigation was to evaluate the therapeutic potential of simvastatin for children with CHD and pulmonary over-circulation, and examine mechanisms of simvastatin action on the endothelium. Our data demonstrate that daily simvastatin treatment preserves endothelial function in our shunt lamb model of pulmonary over-circulation. Further, using pulmonary arterial endothelial cells (PAECs) isolated from Shunt and control lambs, we identified a new mechanism of statin action mediated by increased expression of the endogenous Akt1 inhibitor, C-terminal modifying protein (CTMP). Increases in CTMP were able to decrease the Akt1-mediated mitochondrial redistribution of endothelial nitric oxide synthase (eNOS) which correlated with increased enzymatic coupling, identified by increases in NO generation and decreases in NOS-derived superoxide. Together our data identify a new mechanism by which simvastatin enhances NO signaling in the pulmonary endothelium and identify CTMP as a potential therapeutic target to prevent the endothelial dysfunction that occurs in children born with CHD resulting in pulmonary over-circulation.

[Display omitted] • The brain transcriptional response to acute endotoxemia quickly returns to basal levels. • Reduced expression of mitochondrial activity and translation genes remain for days post LPS. • Loss of endothelial SOCS3 leads to an increase in the transcriptional response to LPS. • Acute endotoxemia leads to mild, sex-dependent cognitive impairment after recovery. Sepsis-associated encephalopathy (SAE) is associated with increased risk of long-term cognitive impairment. SAE is driven, at least in part, by brain endothelial dysfunction in response to systemic cytokine signaling. However, the mechanisms driving SAE and its consequences remain largely unknown. Here, we performed translating ribosome affinity purification and RNA-sequencing (TRAP-seq) from the brain endothelium to determine the transcriptional changes after an acute endotoxemic (LPS) challenge. LPS induced a strong acute transcriptional response in the brain endothelium that partially correlates with the whole brain transcriptional response and suggested an endothelial-specific hypoxia response. Consistent with a crucial role for IL-6, loss of the main regulator of this pathway, SOCS3, leads to a broadening of the population of genes responsive to LPS, suggesting that an overactivation of the IL-6/JAK/STAT3 pathway leads to an increased transcriptional response that could explain our prior findings of severe brain injury in these mice. To identify any potential sequelae of this acute response, we performed brain TRAP-seq following a battery of behavioral tests in mice after apparent recovery. We found that the transcriptional response returns to baseline within days post-challenge, but reductions in gene expression regulating protein translation and respiratory electron transport remained. We observed that mice that recovered from the endotoxemic shock showed mild, sex-dependent cognitive impairment, suggesting that the acute brain injury led to sustained effects. A better understanding of the transcriptional and non-transcriptional changes in response to shock is needed in order to prevent and/or revert the devastating consequences of septic shock. [ABSTRACT FROM AUTHOR]

Cellular senescence is a hallmark of advanced age and a major instigator of numerous inflammatory pathologies. While endothelial cell (EC) senescence is aligned with defective vascular functionality, its impact on fundamental inflammatory responses in vivo at single-cell level remain unclear. To directly investigate the role of EC senescence on dynamics of neutrophil-venular wall interactions, we applied high resolution confocal intravital microscopy to inflamed tissues of an EC-specific progeroid mouse model, characterized by profound indicators of EC senescence. Progerin-expressing ECs supported prolonged neutrophil adhesion and crawling in a cell autonomous manner that additionally mediated neutrophil-dependent microvascular leakage. Transcriptomic and immunofluorescence analysis of inflamed tissues identified elevated levels of EC CXCL1 on progerin-expressing ECs and functional blockade of CXCL1 suppressed the dysregulated neutrophil responses elicited by senescent ECs. Similarly, cultured progerin-expressing human ECs exhibited a senescent phenotype, were pro-inflammatory and prompted increased neutrophil attachment and activation. Collectively, our findings support the concept that senescent ECs drive excessive inflammation and provide new insights into the mode, dynamics, and mechanisms of this response at single-cell level. Synopsis: A murine model of endothelial cell (EC) senescence reveals that exacerbated generation of EC-derived CXCL1 is a driver of pathogenic neutrophil interactions with senescent endothelium at sites of inflammation. Senescent progerin-expressing ECs support aberrant neutrophil adhesion in inflamed tissues. Senescent ECs promote neutrophil-dependent vascular leakage. The pro-inflammatory effects of senescent ECs is mediated by excessive EC production of CXCL1. A murine model of endothelial cell (EC) senescence reveals that exacerbated generation of EC-derived CXCL1 is a driver of pathogenic neutrophil interactions with senescent endothelium at sites of inflammation. [ABSTRACT FROM AUTHOR]

Fluid therapy is a fundamental part of supportive therapy in critical care. However, it is also a suspected risk for endothelial glycocalyx degradation which is associated with poor clinical outcomes. This secondary analysis of RESPONSE randomized trial compares the effect of follow-up strategy (FU) on endothelial biomarkers to that of 500 ml crystalloid fluid bolus (FB) in oliguric, hemodynamically optimized intensive care unit (ICU) patients. 130 adult subjects were enrolled in two Finnish ICUs from January 2017 to November 2020. Blood and urine samples of 63 patients in FU group and 67 patients in FB group were collected before and after the intervention and analyzed using enzyme-linked immunosorbent assays. Single fluid bolus, given after median of 3887 ml (interquartile range 2842; 5359 ml) resuscitation fluids in the preceding 24 h, increased plasma hyaluronan concentration compared to the follow-up strategy (difference in medians 29.2 ng/ml with 95% CI [14.5ng/ml; 55.5ng/ml], P < 0.001). No treatment effect was detected in the plasma levels of syndecan-1, , angiopoietin-2, angiopoietin receptors Tie2 and Tie1, or in soluble thrombomodulin in the adjusted median regression analysis. The increase in hyaluronan was independent of its simultaneous renal clearance but correlated moderately with the increase in endothelium-specific Tie1. The follow-up strategy did not show consistent endothelium-sparing effect but protected against hyaluronan increase. The mechanisms and consequences of hyaluronan fluctuations need further clarification. Trial registration: clinicaltrials.gov, NCT02860572. Registered 1 August 2016, https://www.clinicaltrials.gov/study/NCT02860572?term=NCT02860572&rank=1 [ABSTRACT FROM AUTHOR]

Objective: The endothelial glycocalyx layer (EGL) is the interface between the blood and the endothelium that regulates permeability. This study compared the effects of liberal and restrictive fluid therapies on atrial natriuretic peptide (ANP) release and EGL products in radical cystectomy surgery. We hypothesized that a liberal regimen would damage the glycocalyx layer, resulting in a higher serum EGL product concentration than restrictive therapy. Materials and Methods: Patients were randomized into two groups for restrictive (group R) or liberal (group L) regimens. Group R received 2 mL/kg/h Ringer’s lactate and 2 mcg/kg/h norepinephrine infusion, whereas group L received only Ringer’s lactate infusion at 10 mL/kg/h rate during the surgery. Preoperative and postoperative blood samples were obtained to evaluate ANP levels and glycocalyx degradation products. The stroke volume index, cardiac index, stroke volume variation, and systemic vascular resistance index parameters were recorded at 30-min intervals throughout the surgery. The length of stay in the hospital and intensive care unit and postoperative complications were recorded. Results: The study was completed with 39 patients. Postoperative ANP levels were higher in group L in both between- and within group examination (p<0.05). EGL constituents; syndecan-1 and hyaluronan concentrations, were higher in group L (p<0.05). Advanced hemodynamic parameters indicated insignificant changes between the groups (p>0.05). Postoperative complications and length of stay data were similar (p>0.05). Conclusion: ANP, hyaluronan, and syndecan-1 concentrations can be used as an indirect measurement method to show EGL damage and hypervolemia in major urologic surgeries. Advanced hemodynamic monitoring was ineffective for confirming hypervolemia. [ABSTRACT FROM AUTHOR]

Aim: We aimed to test the hypothesis that a high‐salt diet (HS) impairs NO signaling in kidney microvascular endothelial cells through a histone deacetylase 1 (HDAC1)‐dependent mechanism. Methods: Male Sprague Dawley rats were fed normal salt diet (NS; 0.49% NaCl) or HS (4% NaCl) for 2 weeks. NO signaling was assessed by measuring L‐NAME induced vasoconstriction of the afferent arteriole using the blood perfused juxtamedullary nephron (JMN) preparation. In this preparation, kidneys were perfused with blood from a donor rat on a matching or different diet to that of the kidney donor. Kidney endothelial cells were isolated with magnetic activated cell sorting and HDAC1 activity was measured. Results: We found HS‐induced impaired NO signaling in the afferent arteriole. This was restored by inhibition of HDAC1 with MS‐275. Consistent with these findings, HDAC1 activity was increased in kidney endothelial cells. We further found the loss of NO to be dependent upon the diet of the blood donor rather than the diet of the kidney donor and the plasma from HS‐fed rats to be sufficient to induce impaired NO signaling. This indicates the presence of a humoral factor we termed plasma‐derived endothelial dysfunction mediator (PDEM). Pretreatment with the antioxidants, PEG‐SOD and PEG‐catalase, as well as the NOS cofactor, tetrahydrobiopterin, restored NO signaling. Conclusion: We conclude that HS activates endothelial HDAC1 through PDEM leading to decreased NO signaling. This study provides novel insights into the molecular mechanisms by which a HS decreases renal microvascular endothelial NO signaling. [ABSTRACT FROM AUTHOR]

Ageing is a natural ontogenetic phenomenon that entails a decrease in the adaptive capacity of the organism, as a result of which the body becomes less adaptable to stressful conditions. Nitrate and nitrite enter the body from exogenous sources and from nitrification of ammonia nitrogen by intestinal microorganisms. This review considers the mechanisms of action of l -arginine, a known inducer of nitric oxide (NO) biosynthesis, and nitrates as supplements in the processes of ageing and aggravated stress states, in which mechanisms of individual physiological reactivity play an important role. This approach can be used as an element of individual therapy or prevention of premature ageing processes depending on the different levels of initial reactivity of the functional systems. A search was performed of the PubMed, Scopus, and Google Scholar databases (n = 181 articles) and the author's own research (n = 4) up to May 5, 2023. The review presents analyses of data on targeted treatment of NO generation by supplementation with l -arginine or nitrates, which is a promising means for prevention of hypoxic conditions frequently accompanying pathological processes in an ageing organism. The review clarifies the role of the individual state of physiological reactivity, using the example of individuals with a high predominance of cholinergic regulatory mechanisms who already have a significant reserve of adaptive capacity. In studies of the predominance of adrenergic influences, a poorly trained organism as well as an elderly organism correspond to low resistance, which is an additional factor of damage at increased energy expenditure. Conclusion It is suggested that the role of NO synthesis from supplementation of dietary nitrates and nitrites increases with age rather than from oxygen-dependent biosynthetic reactions from l -arginine supplementation. [ABSTRACT FROM AUTHOR]

Summary: Retinopathy and albuminuria are associated with hip fracture risk. We investigated whether these disorders and endothelial dysfunction (which underlies microvascular diseases) were associated with low trabecular bone density. No significant associations were found, suggesting that microvascular diseases are not related to fracture risk through low trabecular bone density. Purpose: Microvascular diseases of the eye, kidney, and brain are associated with endothelial dysfunction and increased hip fracture risk. To explore the basis for higher hip fracture risk, we comprehensively examined whether markers of microvascular disease and/or endothelial dysfunction are related to trabecular bone mineral density (BMD), a proximate risk factor for osteoporotic fractures. Methods: Among 6814 participants in the Multi-Ethnic Study of Atherosclerosis study (MESA), we derived thoracic vertebral trabecular BMD from computed tomography of the chest and measured urine albumin to creatinine ratios (UACR), retinal arteriolar and venular widths, flow mediated dilation (FMD) of the brachial artery after 5 min of ischemia; and levels of five soluble endothelial adhesion markers (ICAM-1, VCAM-1, L-selectin, P-selectin, and E-selectin). Linear regression models were used to examine the association of trabecular BMD with markers of microvascular disease and with markers of endothelial dysfunction. Results: We observed no significant associations of UACR, retinal arteriolar or venular widths, or FMD with BMD. We also observed no statistically significant association of spine trabecular BMD with levels of endothelial adhesion markers. Men and women had largely similar results. Conclusion: We conclude that there is little evidence to connect thoracic spine trabecular BMD to microvascular disorders or to endothelial dysfunction among multi-ethnic middle-aged and older adults. Other factors beyond trabecular BMD (e.g., bone quality or predisposition to falling) may be responsible for the associations of microvascular disease with osteoporotic fractures. [ABSTRACT FROM AUTHOR]

Red blood cells (RBCs) are the most abundant human blood cells. RBC aggregation and deformation strongly determine blood viscosity which impacts hemorheology and microcirculation. In turn, RBC properties depend on different endogenous and exogenous factors. One such factor is nitric oxide (NO), which is mainly produced by endothelial cells (EC) from L-arginine amino acid in the circulatory system. Since the mechanisms of the RBC-endothelium interplay are not clear up to date and considering its possible clinical importance, the aims of this study are to investigate in vitro: (1) The effect of L-arginine induced NO on RBC aggregation and adhesion to endothelium; (2) the NO effect on RBC aggregation and deformation induced by L-arginine and sodium nitroprusside without the presence of endothelium in the samples. The RBC aggregation and adhesion to a monolayer of EC were studied using optical tweezers (OT). The RBC deformability and aggregation without endothelium in the samples were studied using the flow chamber method and Myrenne aggregometer. We confirmed that NO increases deformability and decreases aggregation of RBCs. We showed that the soluble guanylate cyclase pathway appears to be the only NO signaling pathway involved. In the samples with the endothelium, the "bell-shaped" dependence of RBC aggregation force on L-arginine concentration was observed, which improves our knowledge about the process of NO production by endothelium. Additionally, data related to L-arginine accumulation by endothelium were obtained: Necessity of the presence of extracellular L-arginine stated by other authors was put under question. In our study, NO decreased the RBC-endothelium adhesion, however, the tendency appeared to be weak and was not confirmed in another set of experiments. To our knowledge, this is the first attempt to measure the forces of RBC adhesion to endothelium monolayer with OT. [ABSTRACT FROM AUTHOR]

Endothelial dysfunction (ED) plays a prominent role in the pathogenesis of preeclampsia (PE). There is a need for non-invasive methods to assess endothelial function in preeclamptic patients. In the present study, adropin, autotaxin (ATX), and lysophosphatidic acid (LPA) were evaluated as indicators of ED. Patients diagnosed with PE and healthy pregnant women (n = 42 for each group) were compared. After measuring flow-mediated dilation (FMD), the participants were stratified as ED (+) or ED (−) based on a cut-off value of 6.5%. The PE patients were divided as early/late onset PE and severe/mild PE. Adropin, ATX, and LPA levels were measured, and their relevance to ED was evaluated. Student t, Mann–Whitney U, or ANOVA tests were used for statistics, as appropriate. Adropin levels were diminished in the ED (+) group, whereas ATX and LPA levels were increased. The decrease in adropin levels was more pronounced in severe PE, showing a positive correlation with the FMD. In the logistic regression model, adropin was the only parameter that was an independent variable for the FMD test (P <.001). Adropin measurements in serum may be of value for disease follow-up in patients with PE. [ABSTRACT FROM AUTHOR]

Endothelial dysfunction (ED) is defined as an impairment in the vasodilatory, anti-thrombotic, and anti-inflammatory properties of the cells that make up the lining of blood vessels. ED is considered a key step in the development of atherosclerotic cardiovascular disease. The association between ED and systemic inflammatory diseases is well established. However, the prevalence and clinical significance of ED in psoriatic arthritis (PsA) have been investigated to a lesser extent. This review aims to explore the link between ED and PsA, including ED in macro- and microcirculation, as well as risk factors for its occurrence in PsA and its relationship with atherosclerosis in PsA. Furthermore, the ED in PsA was compared with that of rheumatoid arthritis (RA). Regarding ED in the microcirculation, the coronary flow reserve was found to be significantly reduced in individuals with PsA. The relationship between PsA and macrovascular ED is more pronounced, along with more advanced atherosclerosis detected in patients with PsA. These results are consistent with those obtained in RA studies. On the other hand, arterial stiffness and signs of vascular remodeling were found more frequently in RA than in PsA, with the potential role of efficient anti-TNF treatment in patients with PsA and psoriasis explaining this finding. The impact of ED on cardiovascular diseases and the burden of this risk caused independently by PsA have not yet been precisely established, however, this group of patients requires special attention with regard to cardiovascular events. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the effects of severe COVID-19 infection on the corneal endothelium via in vivo specular microscopy. Methods: This was an observational, prospective, and controlled study including 56 eyes of 56 severe COVID-19 patients, compared to after-recovery and 56 eyes of 56 age- and gender-matched healthy controls. Results: Endothelial cell density was lower in the active disease period compared to healthy controls (p =.001) and decreased even more after recovery (p <.0001). After recovery, the average cell area and coefficient of variation were higher compared to the active disease period (p <.0001 and p =.008, respectively) and the healthy controls (for both, p <.0001), whereas hexagonality was lower (p <.0001). Central corneal thickness increased in the active disease period compared to after recovery (p <.0001) and healthy controls (p =.002). Conclusions: These results may be due to direct host-virus interaction or linked to immune dysregulation, subclinical corneal endotheliitis, or still yet a viral-mediated inflammation. [ABSTRACT FROM AUTHOR]

Purpose: The study aims to investigate changes in tear function, meibomian glands and corneal endothelium in patients receiving systemic isotretinoin therapy. Materials and methods: This prospective study included 38 eyes from 38 patients (23 females and 15 males) treated with systemic isotretinoin (0.5–1 mg/kg/day) following the diagnosis of acne vulgaris. All patients underwent a comprehensive ophthalmologic examination at baseline, 1st month, and third month of treatment. Subjective complaints were assessed using the Ocular Surface Disease Index (OSDI). Tear functions were evaluated through non-invasive tear break up time (NIBUT) and Schirmer I test. Meibomian gland (MG) changes were examined using meibography. Corneal parameters, including endothelial cell density (ECD), coefficient of variation (CV), the number of cells with a hexagonal shape (6A), average cell area (AVG), and central corneal thickness (CCT) were assessed using non-contact specular microscopy. Results: The mean age of the patients was 19.29 ± 2.83 years. Ocular surface-related discomfort, measured with OSDI scores, significantly worsened at the third month measurements compared to the pre-treatment values (p < 0.001). In the 1st month of treatment, there was a significant decrease in NIBUT (p < 0.05). No statistically significant difference was found in the Schirmer test results at each visit. According to the 1st and third-month analysis, there was a significant increase in MG loss compared to the pre-treatment period (p < 0.001). ECD, CV, 6 A, AVG measurements at the first and third months showed a significant change compared to the pre-treatment values (p < 0.001). No significant difference was observed in the CCT measurements during the treatment. Conclusion: Systemic isotretinoin disrupted tear stability, caused MG loss, deterioration in corneal endothelium, and led to symptomatic complaints in patients. [ABSTRACT FROM AUTHOR]

Background: Optimal balance between macro- and microcirculation in critically ill patients is crucial for ensuring optimal organ perfusion. Nitric oxide (NO) is a regulator of vascular hemostasis and tone. The availability of NO is controlled by asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and the availability of the NO substrates arginine and homoarginine. We investigated the changes in plasma concentrations of ADMA, SDMA, arginine, and homoarginine days 1–5 of intensive care unit (ICU) admission and the association between the change in concentration days 1–3 and 30-day all-cause mortality. Methods: Single-center cohort study of adult critically ill patients from the ICU at Copenhagen University Hospital – North Zealand. ADMA, SDMA, arginine, and homoarginine (NO-biomarkers) were measured on days 1–5. Initially, we determined the changes in NO-biomarkers days 1–5 with linear mixed models, and subsequently how the changes in NO-biomarkers days 1–3 were associated with 30-day all-cause mortality. Post-hoc we analyzed the association between plasma concentration at admission and 30-day all-cause mortality. Results: In total 567 out of 577 patients had plasma samples from days 1–5. Plasma concentrations of ADMA and arginine increased from days 1–5. SDMA concentrations increased from days 1–2, followed by a decrease from days 2–5. Concentrations of homoarginine did not change from days 1–3 but slightly increased from days 3–5. In total 512 patients were alive 3 days after ICU admission. Among these patients, a daily twofold increase in ADMA concentration from days 1–3 was associated with decreased mortality in multivariate analysis (HR 0.45; 95% CI 0.21–0.98; p = 0.046). An increase in SDMA, arginine, or homoarginine was not associated with mortality. Post-hoc we found that a twofold increase in ADMA or SDMA concentrations at admission was associated with mortality (HR 1.78; 95% CI 1.24–2.57; p = 0.0025, and HR 1.41; 95% CI 1.05–1.90; p = 0.024, respectively). Conclusions: Increasing ADMA concentrations on days 1–3 are inversely associated with mortality, however not with the same strength as high ADMA or SDMA concentrations at admission. We suggest that admission concentrations are the focus of future research on ADMA and SDMA as predictors of mortality or potential therapeutical targets in ICU patients. [ABSTRACT FROM AUTHOR]

Vascular injury is central to the pathogenesis and progression of cardiovascular diseases, however, fostering alternative strategies to alleviate vascular injury remains a persisting challenge. Given the central role of cell‐derived nitric oxide (NO) in modulating the endogenous repair of vascular injury, NO‐generating proteolipid nanovesicles (PLV‐NO) are designed that recapitulate the cell‐mimicking functions for vascular repair and replacement. Specifically, the proteolipid nanovesicles (PLV) are versatilely fabricated using membrane proteins derived from different types of cells, followed by the incorporation of NO‐generating nanozymes capable of catalyzing endogenous donors to produce NO. Taking two vascular injury models, two types of PLV‐NO are tailored to meet the individual requirements of targeted diseases using platelet membrane proteins and endothelial membrane proteins, respectively. The platelet‐based PLV‐NO (pPLV‐NO) demonstrates its efficacy in targeted repair of a vascular endothelium injury model through systemic delivery. On the other hand, the endothelial cell (EC)‐based PLV‐NO (ePLV‐NO) exhibits suppression of thrombosis when modified onto a locally transplanted small‐diameter vascular graft (SDVG). The versatile design of PLV‐NO may enable a promising therapeutic option for various vascular injury‐evoked cardiovascular diseases. [ABSTRACT FROM AUTHOR]

Simple Summary: Radiobiology has evolved from a mechanistic model based on DNA damage, and other response factors, into a more complex model including effects on the immune system and the tumor microenvironment (TME). Irradiation has an immunomodulatory effect that can manifest as increased anti-tumor immunity or immunosuppression. Irradiation promotes anti-tumor immunity through pro-inflammatory cytokines and endothelial damage, the recruitment of immune cells, and radiation-induced immunogenic cell death (ICD), characterized by the release of damage-associated molecular patterns (DAMPs) and tumor antigens. Irradiation activates both the innate and adaptive arms of the immune system. Irradiation also produces immunosuppression via the recruitment and activation of immune cells, with immunosuppressive effects. In this work, we discuss the mechanism involved in radiation-induced immune effects on which the combination of radiotherapy and immunotherapy for gynecological cancers is based. Radiobiology has evolved from a mechanistic model based on DNA damage and response factors into a more complex model that includes effects on the immune system and the tumor microenvironment (TME). Irradiation has an immunomodulatory effect that can manifest as increased anti-tumor immunity or immunosuppression. Irradiation promotes an inflammatory microenvironment through the release of pro-inflammatory cytokines and endothelial damage, which recruit immune system cells to the irradiated area. Radiation-induced immunogenic cell death (ICD), characterized by the release of damage-associated molecular patterns (DAMPs) and tumor antigens, triggers an anti-tumor immune response of both innate and adaptive immunity. Anti-tumor immunity can manifest at a distance from the irradiated area, a phenomenon known as the abscopal effect (AE), which involves dendritic cells and CD8+ T cells. Irradiation also produces an immunosuppressive effect mediated by tumor-associated macrophages (TAMs) and regulatory T lymphocytes (Tregs), which counterbalances the immunostimulatory effect. In this work, we review the mechanisms involved in the radiation-induced immune response, which support the combined treatment of RT and immunotherapy, focusing, where possible, on gynecologic cancer. [ABSTRACT FROM AUTHOR]

Background and Purpose: The single layer of cells lining all blood vessels, the endothelium, is a sophisticated signal co‐ordination centre that controls a wide range of vascular functions including the regulation of blood pressure and blood flow. To co‐ordinate activities, communication among cells is required for tissue level responses to emerge. While a significant form of communication occurs by the propagation of signals between cells, the mechanism of propagation in the intact endothelium is unresolved. Experimental Approach: Precision signal generation and targeted cellular manipulation was used in conjunction with high spatiotemporal mesoscale Ca2+ imaging in the endothelium of intact blood vessels. Key Results: Multiple mechanisms maintain communication so that Ca2+ wave propagation occurs irrespective of the status of connectivity among cells. Between adjoining cells, regenerative IP3‐induced IP3 production transmits Ca2+ signals and explains the propagated vasodilation that underlies the increased blood flow accompanying tissue activity. The inositide is itself sufficient to evoke regenerative phospholipase C‐dependent Ca2+ waves across coupled cells. None of gap junctions, Ca2+ diffusion or the release of extracellular messengers is required to support this type of intercellular Ca2+ signalling. In contrast, when discontinuities exist between cells, ATP released as a diffusible extracellular messenger transmits Ca2+ signals across the discontinuity and drives propagated vasodilation. Conclusion and Implications: These results show that signalling switches underlie endothelial cell‐to‐cell signal transmission and reveal how communication is maintained in the face of endothelial damage. The findings provide a new framework for understanding wave propagation and cell signalling in the endothelium. [ABSTRACT FROM AUTHOR]

Introduction Methods Results Conclusion Cognitive decline is prevalent in maintenance hemodialysis patients. The blood–brain barrier has been implicated in cognitive decline. In this prospective cohort study, we investigated the associations between endothelium‐related biomarkers and steeper cognitive decline in this population.Cognitive function was assessed using the Portuguese‐adapted Cambridge Cognitive Examination (CAMCOG) with items of the Mini‐Mental State Examination (MMSE). Endothelium‐related biomarkers included syndecan‐1, ICAM‐1, VCAM‐1 and angiopoietin‐2 (AGPT2). Patients were followed up for 4 years, and cognitive assessments were repeated. Multinomial regression analyses were performed to evaluate associations between biomarkers and cognitive decline.A total of 216 patients completed the test battery at baseline. After 4 years, 102 patients had follow‐up data. There was a significant decrease in cognitive function according to the CAMCOG and MMSE scores: a change of −0.39 (95% CI −0.27 to −0.51) and −0.51 (95% CI −0.27 to −0.76) standard deviation (SD) of the baseline scores. Additionally, executive function but not memory significantly decreased. Syndecan‐1 level was independently associated with steeper cognitive decline; each increase in the SD of the syndecan‐1 level was associated with a decrease in the CAMCOG of 0.20 (95% CI 0.07–0.33) SD from baseline. Syndecan‐1 was associated with a steeper decline in MMSE score (β 0.54, 95% CI 0.28–0.81) and executive function (β 0.17, 95% CI 0.02–0.32). Syndecan‐1 predicted severe cognitive impairment with an area under the curve for receiver operating characteristic curves of 0.75 (95% CI 0.64–0.83).Our findings highlight the potential of syndecan‐1, a biomarker of endothelium glycocalyx derangement, as a predictor of steeper cognitive decline in prevalent hemodialysis patients. [ABSTRACT FROM AUTHOR]

The aim of this study was to review the roles of endothelial cells in normal tissue function and to show how COVID‐19 disease impacts on endothelial cell properties that lead to much of its associated symptomatology. This places the endothelial cell as a prominent cell type to target therapeutically in the treatment of this disorder. Advances in glycosaminoglycan analytical techniques and functional glycomics have improved glycosaminoglycan mimetics development, providing agents that can more appropriately target various aspects of the behaviour of the endothelial cell in‐situ and have also provided polymers with potential to prevent viral infection. Thus, promising approaches are being developed to combat COVID‐19 disease and the plethora of symptoms this disease produces. Glycosaminoglycan mimetics that improve endothelial glycocalyx boundary functions have promising properties in the prevention of viral infection, improve endothelial cell function and have disease‐modifying potential. Endothelial cell integrity, forming tight junctions in cerebral cell populations in the blood–brain barrier, prevents the exposure of the central nervous system to circulating toxins and harmful chemicals, which may contribute to the troublesome brain fogging phenomena reported in cognitive processing in long COVID disease. [ABSTRACT FROM AUTHOR]

Objective People living with chronic kidney disease (CKD) and receiving hemodialysis (HD) have impaired respiratory muscle strength and endurance. The objective of this study was to systematically review the effects of inspiratory muscle training (IMT) on respiratory muscle strength, functional capacity, lung function, quality of life, endothelial function, and oxidative stress in people living with CKD and receiving HD. Methods An electronic search was conducted from inception to June 2023. Randomized controlled trials that evaluated the effects of IMT on respiratory muscle strength, functional capacity, lung function, endothelial function, quality of life, or oxidative stress in adults living with CKD and receiving HD, compared with control, placebo IMT, or conventional physical therapy, were included. Results Eight studies were included, totaling 246 people. The meta-analysis showed that IMT increased the maximum inspiratory pressure (MIP) by 22.53 cm H2O, the maximum expiratory pressure (MEP) by 19.54 cm H2O, and the distance covered in the 6-minute walk test by 77.63 m. Changes in lung function and quality of life were not observed. It was not possible to quantitatively analyze data on endothelial function and oxidative stress. Conclusion IMT improves MIP, MEP, and functional capacity in people living with CKD and receiving HD. IMT did not demonstrate significant results for lung function and quality of life. Effects on endothelial function and oxidative capacity remain uncertain. Impact Inspiratory muscle training improves MIP, MEP, and functional capacity in people living with CKD and receiving HD, compared with conventional physical therapy or controls or placebo intervention. Increases in functional capacity in this population are extremely important because of the relationship with the survival of these people. [ABSTRACT FROM AUTHOR]

Air pollution is recognized as a risk factor for cardiovascular diseases; however, the precise underlying mechanisms remain unclear. This study investigated the impact of occupational air pollution exposure on endothelial function in workers within the steel industry. Specifically, we examined male employees in the cokemaking division of the Isfahan Steel Company in Iran, as well as those in administrative roles with no known history of cardiovascular risk. Data on age, body mass index, duration of employment, blood pressure, fasting blood sugar, and lipid profile were collected. To assess endothelial function, flow-mediated dilation (FMD) was measured. The baseline brachial artery diameter was greater (mean difference [95% CI] = 0.068 mm [0.008 to 0.128]), while the FMD was lower (mean difference [95% CI] = -0.908 % [-1.740 to -0.075]) in the cokemaking group than in the control group. After controlling for potential confounding variables, it was observed that working in the coke-making sector of the industry was associated with lower FMD (F = 3.954, p = .049). These findings indicated that occupational air pollution exposure among workers in the steel industry is linked to impaired endothelium-dependent vasodilation. [ABSTRACT FROM AUTHOR]

The antiphospholipid syndrome (APS) is an autoimmune disease characterized by the presence of pathogenic antiphospholipid antibodies (aPL). Since approximately 30 years ago, lipid-binding aPL, which do not require a protein cofactor, have been regarded as irrelevant for APS pathogenesis even though anticardiolipin are a diagnostic criterion of APS. In this review, we will summarize the available evidence from in vitro studies, animal models, and epidemiologic studies, which suggest that this concept is no longer tenable. Accordingly, we will only briefly touch on the role of other aPL in APS. This topic has been amply reviewed in detail elsewhere. We will discuss the consequences for laboratory diagnostics and future research required to resolve open questions related to the pathogenic role of different aPL specificities. [ABSTRACT FROM AUTHOR]

An increasing body of evidence suggests a pivotal role for the microvasculature in the development of cardiovascular disease. A dysfunctional coronary microvascular network, specifically within endothelial cells—the inner most cell layer of vessels—is considered a strong, independent risk factor for future major adverse cardiac events. However, challenges exist with evaluating this critical vascular bed, as many of the currently available techniques are highly invasive and cost prohibitive. The more easily accessible peripheral microcirculation has surfaced as a potential surrogate in which to study mechanisms of coronary microvascular dysfunction and likewise may be used to predict poor cardiovascular outcomes. In this review, we critically evaluate a variety of prognostic, physiological, and mechanistic studies in humans to answer whether the peripheral microcirculation can add insight into coronary microvascular health. A conceptual framework is proposed that the health of the endothelium specifically may link the coronary and peripheral microvascular beds. This is supported by evidence showing a correlation between human coronary and peripheral endothelial function in vivo. Although not a replacement for investigating and understanding coronary microvascular function, the microvascular endothelium from the periphery responds similarly to (patho)physiological stress and may be leveraged to explore potential therapeutic pathways to mitigate stress-induced damage. [Display omitted] • Peripheral microvascular endothelial dysfunction has emerged as a strong independent predictor of poor cardiovascular outcomes. • For the special issue on Microvessels in the Heart , we pose the question of whether peripheral microvessels can be leveraged to answer key questions regarding coronary endothelial health. • Finally, we explore the endothelium as the potential link between the coronary and endothelial vascular beds and identify remaining important and unanswered questions. [ABSTRACT FROM AUTHOR]

Although the cause of interstitial cystitis/painful bladder syndrome (IC/PBS) remains unknown, autoimmune involvement has been strongly suggested to be a contributing factor. To elucidate the pathophysiology of IC/PBS, we characterized the experimental autoimmune cystitis (EAC) in rats. Adult female Sprague-Dawley rats were divided into the EAC and control groups. The EAC rats were generated by administrating a homogenate of donor rat bladder tissue as a bladder antigen. The characteristics of the two groups were determined by evaluating pain behavior and conducting cystometry, histopathology, and molecular analyses. The EAC rats showed: 1) a decreased paw withdrawal threshold, 2) a reduced intercontraction interval on cystometry, 3) the irregular surfaces of the umbrella cells of epithelium throughout the bladder wall, 4) accumulation of stress granules in the bladder and vascular endothelium, 5)the increased expression of genes related to inflammation and ischemia at the mRNA and protein levels, 6) a significantly increased paw withdrawal threshold with pain treatment, and 7) the induction of glomerulation of the bladder wall, epithelium denudation, and lymphocyte infiltration in the interstitium by bladder distension. These results suggest that the EAC rats showed pain and frequent urination with the overexpression of inflammatory chemokines, reflecting clinical IC/BPS, and the bladder epithelium and vascular endothelium may be the primary sites of IC/BPS, and bladder injury, such as bladder distension, can cause progression from BPS to IC with Hunner lesions. NEW & NOTEWORTHY: The experimental autoimmune cystitis model rats showed pain and frequent urination with the overexpression of inflammatory chemokines, reflecting clinical interstitial cystitis/painful bladder syndrome (IC/PBS), and the bladder epithelium and vascular endothelium may be the primary sites of IC/BPS, and bladder injury, such as bladder distension, can cause progression from BPS to IC with Hunner lesions. [ABSTRACT FROM AUTHOR]

The lymphatic network of capillaries and collecting vessels ensures tissue fluid homeostasis, absorption of dietary fats and trafficking of immune cells. Pannexin1 (Panx1) channels allow for the passage of ions and small metabolites between the cytosol and extracellular environment. Panx1 channels regulate the pathophysiological function of several tissues in a sex‐dependent manner. Here, we studied the role of Panx1 in lymphatic function, and potential sex‐dependent differences therein, in Prox1‐CreERT2Panx1fl/fl and Panx1fl/fl control mice. Panx1 expression was higher in lymphatic endothelial cells (LECs) of male mice. Lymphatic vessel morphology was not affected in Prox1‐CreERT2Panx1fl/fl male and female mice. Lymphatic drainage was decreased by 25% in male Prox1‐CreERT2Panx1fl/fl mice, but was similar in females of both genotypes. Accordingly, only male Prox1‐CreERT2Panx1fl/fl mice exhibited tail swelling, pointing to interstitial fluid accumulation in males upon Panx1 deletion in LECs. Moreover, serum triglyceride and free fatty acid levels raised less in Prox1‐CreERT2Panx1fl/fl mice of both sexes in an oral lipid tolerance test. Finally, the percentage of migratory dendritic cells arriving in draining lymph nodes was increased in Prox1‐CreERT2Panx1fl/fl female mice, but was comparable between male mice of both genotypes. Our results point to a LEC‐specific role for Panx1 in the functions of the lymphatic system. [ABSTRACT FROM AUTHOR]

Acute hyperglycemia is a transient increase in plasma glucose level (PGL) frequently observed in patients with ST-elevation myocardial infarction (STEMI). The aim of this review is to clarify the molecular mechanisms whereby acute hyperglycemia impacts coronary flow and myocardial perfusion in patients with acute myocardial infarction (AMI) and to discuss the consequent clinical and prognostic implications. We conducted a comprehensive literature review on the molecular causes of myocardial damage driven by acute hyperglycemia in the context of AMI. The negative impact of high PGL on admission recognizes a multifactorial etiology involving endothelial function, oxidative stress, production of leukocyte adhesion molecules, platelet aggregation, and activation of the coagulation cascade. The current evidence suggests that all these pathophysiological mechanisms compromise myocardial perfusion as a whole and not only in the culprit coronary artery. Acute hyperglycemia on admission, regardless of whether or not in the context of a diabetes mellitus history, could be, thus, identified as a predictor of worse myocardial reperfusion and poorer prognosis in patients with AMI. In order to reduce hyperglycemia-related complications, it seems rational to pursue in these patients an adequate and quick control of PGL, despite the best pharmacological treatment for acute hyperglycemia still remaining a matter of debate. [ABSTRACT FROM AUTHOR]

Piezo are mechanosensitive non‐selective cation channels that are suggested to be involved in vascular development and function. The aim of our study was to determine any sex‐specific contributions of the mechanosensitive Piezo 1 channels on blood vessel wall stiffness. Composite Young modulus (CYM) was determined using pressure myograph experimental approach using third‐order mesenteric arteries (intact and denuded) from Dahl salt‐sensitive male and female normotensive and hypertensive rats (n = 6–8). The effects of Piezo 1 agonist (Yoda 1; 10 μM), and antagonist (GsMTx‐4; 2 μM) were studied in intact and denuded vessels. The distribution of Piezo 1 was identified using immunohistochemistry. In intact blood vessels, there were no differences in CYM between the experimental groups, however, removal of the endothelium unmasked significant increases in CYM in normotensive males and female groups compared to hypertensive males. The presence of Yoda 1 did not affect CYM in any groups. In the intact tissues, GsMTx‐4 led to significant increases in CYM in hypertensive females, and normotensive males and females, but not in hypertensive males. In the denuded vessels, GsMTx‐4, produced a significant increase in CYM but only in the female normotensives. Differential expression of Piezo 1 were found in male versus female blood vessels. Our findings support a greater contribution of Piezo 1 mechanoceptors to vascular biomechanics of male hypertensive compared to male normotensive or female groups. The evidence also points to a possible differential vasoregulatory role for Piezo 1 in endothelial versus vascular smooth cells, with a greater contribution in males than females. [ABSTRACT FROM AUTHOR]

Background: Obesity, a major component of cardiometabolic syndrome, contributes to the imbalance between pro- and anti-atherosclerotic factors via dysregulation of adipocytokine secretion. Among these adipocytokines, the C1q/TNF-related proteins (CTRPs) play a role in the modulation of atherosclerosis development and progression. Here, we investigated the vascular effects of CTRP13. Results: CTRP13 is not only expressed in adipose tissue but also in vessels/endothelial cells (ECs) of mice, rats, and humans. Obese individuals (mice, rats, and humans) showed higher vascular CTRP13 expression. Human Umbilical Vein Endothelial Cells (HUVECs), cultured in the presence of serum from obese mice, mimicked this obesity-associated effect on CTRP13 protein expression. Similarly, high glucose conditions and TNF-alpha, but not insulin, resulted in a strong increase in CTRP13 in these cells. Recombinant CTRP13 induced a reduction in EC proliferation via AMPK. In addition, CTRP13 reduced cell cycle progression and increased p53 phosphorylation and p21 protein expression, but reduced Rb phosphorylation, with the effects largely depending on alpha-2 AMPK as suggested by adenoviral overexpression of dominant-negative (DN) or wild-type (WT) alpha 1/alpha 2 AMPK. Conclusion: The present study demonstrates that CTRP13 expression is induced in ECs under diabetic conditions and that CTRP13 possesses significant vaso-modulatory properties which may have an impact on vascular disease progression in patients. [ABSTRACT FROM AUTHOR]

Background and Purpose: An estimated 40% of patients with erectile dysfunction have a poor prognosis for improvement with currently available treatments. The present study investigated whether a newly developed monoamine transport inhibitor, IP2015, improves erectile function. Experimental Approach: We investigated the effects of IP2015 on monoamine uptake and binding, erectile function in rats and diabetic mice and the effect on corpus cavernosum contractility. Key Results: IP2015 inhibited the uptake of 5‐HT, noradrenaline and dopamine by human monoamine transporters expressed in cells and in rat brain synaptosomes. Intracavernosal pressure measurement in anaesthetized rats revealed that IP2015 dose‐dependently increased the number and the duration of spontaneous erections. Whereas pretreatment with the dopamine D2‐like receptor antagonists, clozapine and (−)‐sulpiride, or cutting the cavernosal nerve inhibited IP2015‐induced erectile responses, the phosphodiesterase type 5 inhibitor sildenafil further enhanced the IP2015‐mediated increase in intracavernosal pressure. IP2015 also increased the number of erections in type 2 diabetic db/db mice. Direct intracavernosal injection of IP2015 increased penile pressure, and in corpus cavernosum strips, IP2015 induced concentration‐dependent relaxations. These relaxations were enhanced by sildenafil and blunted by endothelial cell removal, a nitric oxide synthase inhibitor, NG‐nitro‐l‐arginine and a D1‐like receptor antagonist, SCH23390. Quantitative polymerase chain reaction (qPCR) showed the expression of the dopamine transporter in the rat corpus cavernosum. Conclusion and Implications: Our findings suggest that IP2015 stimulates erectile function by a central mechanism involving dopamine reuptake inhibition and direct NO‐mediated relaxation of the erectile tissue. This novel multi‐modal mechanism of action could offer a new treatment approach to erectile dysfunction. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Mild cognitive impairment (MCI) is a prodromal stage of dementia. Understanding the mechanistic changes from healthy aging to MCI is critical for comprehending disease progression and enabling preventative intervention. METHODS: Patients with MCI and age‐matched controls (CN) were administered cognitive tasks during functional near‐infrared spectroscopy (fNIRS) recording, and changes in plasma levels of extracellular vesicles (EVs) were assessed using small‐particle flow cytometry. RESULTS: Neurovascular coupling (NVC) and functional connectivity (FC) were decreased in MCI compared to CN, prominently in the left‐dorsolateral prefrontal cortex (LDLPFC). We observed an increased ratio of cerebrovascular endothelial EVs (CEEVs) to total endothelial EVs in patients with MCI compared to CN, correlating with structural MRI small vessel ischemic damage in MCI. LDLPFC NVC, CEEV ratio, and LDLPFC FC had the highest feature importance in the random Forest group classification. DISCUSSION: NVC, CEEVs, and FC predict MCI diagnosis, indicating their potential as markers for MCI cerebrovascular pathology. Highlights: Neurovascular coupling (NVC) is impaired in mild cognitive impairment (MCI).Functional connectivity (FC) compensation mechanism is lost in MCI.Cerebrovascular endothelial extracellular vesicles (CEEVs) are increased in MCI.CEEV load strongly associates with cerebral small vessel ischemic lesions in MCI.NVC, CEEVs, and FC predict MCI diagnosis over demographic and comorbidity factors. [ABSTRACT FROM AUTHOR]

Introduction: SARS-CoV-2 infection causes severe endothelial damage, an essential step for cardiovascular complications. Endothelial-colony forming cells (ECFCs) act as a biomarker of vascular damage but their role in SARS-CoV-2 remain unclear. The aim of this study was to assess whether the number of ECFCs and angiogenic biomarkers remained altered after 6 and 12-months post-infection and whether this imbalance correlated with the presence of long-COVID syndrome and other biological parameters measured. Methods: Seventy-two patients were recruited at different time-points after overcoming COVID-19 and thirty-one healthy controls. All subjects were matched for age, gender, BMI, and comorbidities. ECFCs were obtained from peripheral blood and cultured with specific conditions. Results: The results confirm the presence of a long-term sequela in post-COVID-19 patients, with an abnormal increase in ECFC production compared to controls (82.8% vs. 48.4%, P < 0.01) that is maintained up to 6-months (87.0% vs. 48.4%, P < 0.01) and 12-months post-infection (85.0% vs. 48.4%, P < 0.01). Interestingly, post-COVID-19 patients showed a significant downregulation of angiogenesis-related proteins compared to controls indicating a clear endothelial injury. Troponin, NT-proBNP and ferritin levels, markers of cardiovascular risk and inflammation, remained elevated up to 12-months post-infection. Patients with lower numbers of ECFC exhibited higher levels of inflammatory markers, such as ferritin, suggesting that ECFCs may play a protective role. Additionally, long-COVID syndrome was associated with higher ferritin levels and with female gender. Conclusions: These findings highlight the presence of vascular sequela that last up to 6- and 12-months post-infection and point out the need for preventive measures and patient follow-up. [ABSTRACT FROM AUTHOR]

Cardiovascular disease (CVD) remains to be the leading cause of death globally today and therefore the need for the development of novel therapies has become increasingly important in the cardiovascular field. The mechanism(s) behind the pathophysiology of CVD have been laboriously investigated in both stem cell and bioengineering laboratories. Scientific breakthroughs have paved the way to better mimic cell types of interest in recent years, with the ability to generate any cell type from reprogrammed human pluripotent stem cells. Mimicking the native extracellular matrix using both organic and inorganic biomaterials has allowed full organs to be recapitulated in vitro. In this paper, we will review techniques from both stem cell biology and bioengineering which have been fruitfully combined and have fueled advances in the cardiovascular disease field. We will provide a brief introduction to CVD, reviewing some of the recent studies as related to the role of endothelial cells and endothelial cell dysfunction. Recent advances and the techniques widely used in both bioengineering and stem cell biology will be discussed, providing a broad overview of the collaboration between these two fields and their overall impact on tissue engineering in the cardiovascular devices and implications for treatment of cardiovascular disease. [ABSTRACT FROM AUTHOR]

This research letter discusses a study that examined the reprogramming of general capillary endothelial cells into arterial endothelial cells in pulmonary hypertension (PH). The study used single-cell RNA sequencing (scRNA-seq) analysis to examine lung endothelial cells in mice with PH and found an increase in arterial endothelial cells and a decrease in general capillary endothelial cells. The researchers also observed a similar increase in arterial endothelial cells in patients with idiopathic PH. The study suggests that Cxcl12 could be a novel marker for arterial endothelial cells in the microvasculature during PH development. The study also identified Sox17 and Notch4 as key molecules involved in this transition and demonstrated that inhibiting Notch4 signaling could prevent the pathological gCap-to-arterial reprogramming in PH. [Extracted from the article]

Background: In cardiovascular disease, high blood pressure is associated with oxidative stress, promoting endothelial dysfunction, vascular remodeling, and inflammation. Clinical trials are discordant that the most effective treatment in the management of hypertension seems to be the administration of anti-hypertensive drugs with antioxidant properties. The study aims to evaluate the effects of the eutomer of thioctic acid on oxidative stress and inflammation in the heart of spontaneously hypertensive rats compared to normotensive Wistar Kyoto rats. Methods: To study the oxidative status, the malondialdehyde and 4-hydroxynonenal concentration, protein oxidation were measured in the heart. Morphological analysis were performed. Immunohistochemistry and Western blot were done for alpha-smooth muscle actin and transforming growth factor beta to assess fibrosis; cytokines and nuclear factor kappaB to assess inflammatory processes. Results: Spontaneously hypertensive rats were characterized by hypertension with increased malondialdehyde levels in the heart. OxyBlot in the heart of spontaneously hypertensive rats showed an increase in proteins' oxidative status. Cardiomyocyte hypertrophy and fibrosis in the ventricles were associated with an increased expression of alpha-smooth muscle actin and pro-inflammatory cytokines, reduced by the eutomer of thioctic acid supplementation. Conclusions: Based on this evidence, eutomer of thioctic acid could represent an appropriate antioxidant molecule to reduce oxidative stress and prevent inflammatory processes on the cardiomyocytes and cardiac vascular endothelium. [ABSTRACT FROM AUTHOR]

Introduction: As the body's first line of defense against disease and infection, neutrophils must efficiently navigate to sites of inflammation; however, neutrophil dysregulation contributes to the pathogenesis of numerous diseases that leave people susceptible to infections. Many of these diseases are also associated with changes to the protein composition of the extracellular matrix. While it is known that neutrophils and endothelial cells, which play a key role in neutrophil activation, are sensitive to the mechanical and structural properties of the extracellular matrix, our understanding of how protein composition in the matrix affects the neutrophil response to infection is incomplete. Methods: To investigate the effects of extracellular matrix composition on the neutrophil response to infection, we used an infection-on-a-chip microfluidic device that replicates a portion of a blood vessel endothelium surrounded by a model extracellular matrix. Model blood vessels were fabricated by seeding human umbilical vein endothelial cells on 2, 4, or 6 mg/mL type I collagen hydrogels. Primary human neutrophils were loaded into the endothelial lumens and stimulated by adding the bacterial pathogen Pseudomonas aeruginosa to the surrounding matrix. Results: Collagen concentration did not affect the cell density or barrier function of the endothelial lumens. Upon infectious challenge, we found greater neutrophil extravasation into the 4 mg/mL collagen gels compared to the 6 mg/mL collagen gels. We further found that extravasated neutrophils had the highest migration speed and distance in 2mg/mL gels and that these values decreased with increasing collagen concentration. However, these phenomena were not observed in the absence of an endothelial lumen. Lastly, no differences in the percent of extravasated neutrophils producing reactive oxygen species were observed across the various collagen concentrations. Discussion: Our study suggests that neutrophil extravasation and migration in response to an infectious challenge are regulated by collagen concentration in an endothelial cell-dependent manner. The results demonstrate how the mechanical and structural aspects of the tissue microenvironment affect the neutrophil response to infection. Additionally, these findings underscore the importance of developing and using microphysiological systems for studying the regulatory factors that govern the neutrophil response. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate whether endothelin‐A receptor (ETAR) inhibition in non‐Hispanic Black (NHB) and White (NHW) young adults depends on biological sex. We recruited females during low hormone (n = 22) and high hormone (n = 22) phases, and males (n = 22). Participants self‐identified as NHB (n = 33) or NHW (n = 33). Participants were instrumented with two microdialysis fibers: (1) lactated Ringer's (control) and (2) 500 nM BQ‐123 (ETAR antagonist). Local heating was used to elicit cutaneous vasodilation, and an infusion of 20 mM L‐NAME to quantify NO‐dependent vasodilation. At control sites, NO‐dependent vasodilation was lowest in NHB males (46 ± 13 %NO) and NHB females during low hormone phases (47 ± 12 %NO) compared to all NHW groups. Inhibition of ETAR increased NO‐dependent vasodilation in NHB males (66 ± 13 %NO), in both groups of females during low hormone phases (NHW, control: 64 ± 12 %NO, BQ‐123: 85 ± 11 %NO; NHB, BQ‐123: 68 ± 13 %NO), and in NHB females during high hormone phases (control: 61 ± 11 %NO, BQ‐123: 83 ± 9 %NO). There was no effect for ETAR inhibition in NHW males or females during high hormone phases. These data suggest the effect of ETAR inhibition on NO‐dependent vasodilation is influenced by biological sex and racial identity. [ABSTRACT FROM AUTHOR]

Purpose Methods Results Conclusions To evaluate the use of vital dyes and light microscopy for assessing canine corneal endothelial morphology ex vivo.The corneas of 40 canine eyes (n = 20 dogs) enucleated <24 h following euthanasia or death were isolated and flat‐mounted on a slide. Corneal endothelium was stained via 0.25% trypan blue followed by 0.5% alizarin red (pH 4.2), photographed, then the following morphological features were calculated using ImageJ: mean cell density (MCD), mean cell area (MCA), polymegathism (coefficient of variation of cell area), and pleomorphism (% hexagonality).Mean ± standard deviation (range) outcomes were: MCD, 2544 ± 541 cells/mm2 (1750–3922 cells/mm2); MCA, 431 ± 97 μm2 (251–626 μm2); polymegathism, 17 ± 2% (14%–22%); pleomorphism, 84 ± 3% (80%–90%). No significant differences (p ≥ .122) were noted for any outcome between male versus female or brachycephalic versus non‐brachycephalic dogs. Young dogs (<10 years) had lower MCA (p = .044), lower pleomorphism (p = .003), and higher MCD (p = .035) when compared to older dogs (≥10 years). Age was significantly (p ≤ .049) correlated with MCA (r = 0.467), MCD (r = −0.476), polymegathism (r = 0.444), and pleomorphism (r = 0.609).The combination of vital dyes and light microscopy allowed for clear visualization and evaluation of the corneal endothelium in canine eyes ex vivo. Our findings can be used in future studies to deepen our understanding of the corneal endothelium in health and disease. [ABSTRACT FROM AUTHOR]

Previous studies have revealed the medicinal and therapeutic effects of Galla chinensis. However, no studies have focused on the antihypertensive effects of G. chinensis. Therefore, we aimed to determine the vasorelaxant and hypotensive effects of G. chinensis 50% ethanolic extract (GCE). To evaluate the vascular relaxing effect of GCE, experiments were conducted using aortic segments dissected from Sprague Dawley rats. GCE showed a vasorelaxant effect via the nitric oxide/cyclic guanosine 3′,5′-monophosphate pathway, inhibiting Ca2+ channels, and activating K+ channels. The hypotensive effects of GCE were evaluated in spontaneously hypertensive rats (SHRs). The SHRs were randomly divided into a control group and orally administered GCE group (100 or 300 mg/kg). The systolic and diastolic blood pressure decreased significantly by −19.47 ± 4.58% and −31.14 ± 7.66% in the GCE 100 mg/kg group, and −21.64 ± 2.40% and −31.91 ± 5.75% in the GCE 300 mg/kg group at 4 h after administration. Considering its vasorelaxant and hypotensive effects, our results indicate that GCE may be a valuable solution for the control of hypertension. However, further studies on the long-term administration and toxicity of GCE are required. [ABSTRACT FROM AUTHOR]

Erythropoietin (EPO) exerts non-canonical roles beyond erythropoiesis that are developmentally, structurally, and physiologically relevant for the heart as a paracrine factor. The role for paracrine EPO signalling and cellular crosstalk in the adult is uncertain. Here, we provided novel evidence showing cardiomyocyte restricted loss of function in Epo in adult mice induced hyper-compensatory increases in Epo expression by adjacent cardiac endothelial cells via HIF-2α independent mechanisms. These hearts showed concentric cellular hypertrophy, elevated contractility and relaxation, and greater resistance to ischemia-reperfusion injury. Voluntary exercise capacity compared to control hearts was improved independent of any changes to whole-body metabolism or blood O2 content or delivery (i.e., hematocrit). Our findings suggest cardiac EPO had a localized effect within the normoxic heart, which was regulated by cellspecific EPO-reciprocity between cardiomyocytes and endothelium. Within the heart, hyper-compensated endothelial Epo expression was accompanied by elevated Vegfr1 and Vegfb RNA, that upon pharmacological pan-inhibition of VEGF-VEGFR signaling, resulted in a paradoxical upregulation in whole-heart Epo. Thus, we provide the first evidence that a novel EPO-EPOR/VEGF-VEGFR axis exists to carefully mediate cardiac homeostasis via cardiomyocyteendothelial EPO crosstalk. [ABSTRACT FROM AUTHOR]

Myocardial ischemia‐reperfusion injury (MIRI) represents a critical pathology in acute myocardial infarction (AMI), which is characterized by high mortality and morbidity. Cardiac microvascular dysfunction contributes to MIRI, potentially culminating in heart failure (HF). Pigment epithelium‐derived factor (PEDF), which belongs to the non‐inhibitory serpin family, exhibits several physiological effects, including anti‐angiogenesis, anti‐inflammatory and antioxidant properties. Our study aims to explore the impact of PEDF and its functional peptide 34‐mer on both cardiac microvascular perfusion in MIRI rats and human cardiac microvascular endothelial cells (HCMECs) injury under hypoxia reoxygenation (HR). It has been shown that MIRI is accompanied by ferroptosis in HCMECs. Furthermore, we investigated the effect of PEDF and its 34‐mer, particularly regarding the Nrf2/HO‐1 signalling pathway. Our results demonstrated that PEDF 34‐mer significantly ameliorated cardiac microvascular dysfunction following MIRI. Additionally, they exhibited a notable suppression of ferroptosis in HCMECs, and these effects were mediated through activation of Nrf2/HO‐1 signalling. These findings highlight the therapeutic potential of PEDF and 34‐mer in alleviating microvascular dysfunction and MIRI. By enhancing cardiac microvascular perfusion and mitigating endothelial ferroptosis, PEDF and its derivative peptide represent promising candidates for the treatment of AMI. [ABSTRACT FROM AUTHOR]

Background Study Design and Methods Results Discussion Septic shock is associated with high morbidity and mortality, the endothelium plays an important role. Crystalloids is standard of care to maintain intravascular volume. Plasma is associated with improved endothelial integrity and restoration of the glycocalyx layer. We evaluated the efficacy and safety aspects of cell‐free and pathogen inactivated pooled plasma (OctaplasLG®) as resuscitation in septic shock patients.This randomized, investigator‐initiated phase IIa trial ran at a Danish single center intensive care unit, from 2017 to 2019. Patients were 18 years of age or older with septic shock and randomized to fluid optimization with OctaplasLG® or Ringer‐acetate in the first 24 h. The primary endpoints were changes in biomarkers indicative of endothelial activation, damage, and microvascular perfusion from baseline to 24 h. Safety events and mortality were assessed during 90 days.Forty‐four patients were randomized, 20 to OctaplasLG versus 24 to Ringer‐acetate. The median age was 69, and 55% were men. Median Sequential Organ Failure Assessment score was 13. Baseline differences favoring the Ringer‐acetate group were observed. The OctaplasLG® group was resuscitated with 740 mL plasma and the Ringer‐acetate group with 841 mL crystalloids. There was no significant change in the microvascular perfusion or five biomarkers except VEGFR1 change, which was higher in patients receiving OctaplasLG® 0.12(SD 0.37) versus Ringer‐acetate −0.24 (SD 0.39), with mean difference 0.36 (95% CI, 0.13–0.59, p = .003) in favor of Ringer‐acetate.This study found that fluid resuscitation with OctaplasLG® in critically ill septic shock patients is feasible. Baseline confounding prevented assessment of the potential effect of OctaplasLG®. [ABSTRACT FROM AUTHOR]

Continuous-flow ventricular assist devices (CFVAD) and counterpulsation devices (CPD) are used to treat heart failure (HF). CFVAD can diminish pulsatility, but pulsatile modes have been implemented to increase vascular pulsatility. The effects of CFVAD in a pulsatile mode and CPD support on the function of endothelial cells (ECs) are yet to be investigated. In this study, two in vitro microfluidic models for culturing ECs are proposed to reproduce blood pressure (BP) and wall shear stress (WSS) on the arterial endothelium while using these medical devices. The layout and parameters of the two microfluidic systems were optimized based on the principle of hemodynamic similarity to efficiently simulate physiological conditions. Moreover, the unique design of the double-pump and double afterload systems could successfully reproduce the working mode of CPDs in an in vitro microfluidic system. The performance of the two systems was verified by numerical simulations and in vitro experiments. BP and WSS under HF, CFVAD in pulsatile modes, and CPD were reproduced accurately in the systems, and these induced signals improved the expression of Ca2+, NO, and reactive oxygen species in ECs, proving that CPD may be effective in normalizing endothelial function and replacing CFVAD to a certain extent to treat non-severe HF. This method offers an important tool for the study of cell mechanobiology and a key experimental basis for exploring the potential value of mechanical circulatory support devices in reducing adverse events and improving outcomes in the treatment of HF in the future. [ABSTRACT FROM AUTHOR]

Background: Garcinia cowa Roxb. ex Choisy (G. cowa) is used in traditional medicine, both for improvement of blood circulation and indigestion, also as an antipyretic and expectorant. Objective: This study investigated the vasorelaxant effects and possible mechanisms of action of G. cowa leaf ethanolic extract (GCE) on the rat isolated thoracic aorta. Methods: The study examined the effects of GCE on isolated rat thoracic aorta, including both endothelium-intact and endothelium-denuded aortic rings, using an organ bath system. Specific inhibitors were used to evaluate the mechanism involved in GCE-induced vasorelaxation. Results: GCE (0.01-10 mg/mL) relaxed endothelium-intact aortic rings, that had been precontracted with phenylephrine. Removal of the endothelium or pretreatment of endothelium-intact aortic rings with Nω-nitro-L-arginine methyl ester (L-NAME), or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), significantly decreased vasorelaxation induced by the GCE. Indomethacin or propranolol had no effect on the GCE-induced relaxation of the endothelium-intact aortic rings. In endothelium-denuded aortic rings, the relaxation effect of GCE was significantly blocked by 4-aminopyridine (4-AP) and tetraethylammonium (TEA) at the maximum dose of GCE, but not by glibenclamide. In Ca2+-free Krebs solution, GCE (5 and 10 mg/mL) significantly inhibited extracellular Ca2+ induced contraction in pre-contracted rings with high KCl levels. Conclusions: These findings suggest that GCE exhibits both an endothelium-dependent, which is mediated by an eNOS/NO/sGC pathway, and an endothelium-independent pathway, which involves KCa and KV channels opening and extracellular Ca2+ influx inhibition. Kaempferol, isovitexin, quercetin, apigenin, luteolin, and amentoflavone might play a role in inducing the vasorelaxant effect of GCE. [ABSTRACT FROM AUTHOR]

Sustained tumor angiogenesis, i.e., the induction and maintenance of blood vessel growth by tumor cells, is one of the hallmarks of cancer. The vascularization of malignant tissues not only facilitates tumor growth and metastasis, but also contributes to immune evasion. Important players in all these processes are the endothelial cells which line the luminal side of blood vessel. In the tumor vasculature, these cells are actively involved in angiogenesis as well in the hampered recruitment of immune cells. This is the result of the abnormal tumor microenvironment which triggers both angiostimulatory and immune inhibitory gene expression profiles in endothelial cells. In recent years, it has become evident that galectins constitute a protein family that is expressed in the tumor endothelium. Moreover, several members of this glycan-binding protein family have been found to facilitate tumor angiogenesis and stimulate immune suppression. All this has identified galectins as potential therapeutic targets to simultaneously hamper tumor angiogenesis and alleviate immune suppression. The current review provides a brief introduction in the human galectin protein family. The current knowledge regarding the expression and regulation of galectins in endothelial cells is summarized. Furthermore, an overview of the role that endothelial galectins play in tumor angiogenesis and tumor immunomodulation is provided. Finally, some outstanding questions are discussed that should be addressed by future research efforts. This will help to fully understand the contribution of endothelial galectins to tumor progression and to exploit endothelial galectins for cancer therapy. [ABSTRACT FROM AUTHOR]

Coronary artery bypass surgery can result in endothelial dysfunction due to ischemia/reperfusion (IR) injury. Previous studies have demonstrated that DuraGraft helps maintain endothelial integrity of saphenous vein grafts during ischemic conditions. In this study, we investigated the potential of DuraGraft to mitigate endothelial dysfunction in arterial grafts after IR injury using an aortic transplantation model. Lewis rats (n = 7–9/group) were divided in three groups. Aortic arches from the control group were prepared and rings were immediately placed in organ baths, while the aortic arches of IR and IR + DuraGraft rats were preserved in saline or DuraGraft, respectively, for 1 h before being transplanted heterotopically. After 1 h after reperfusion, the grafts were explanted, rings were prepared, and mounted in organ baths. Our results demonstrated that the maximum endothelium-dependent vasorelaxation to acetylcholine was significantly impaired in the IR group compared to the control group, but DuraGraft improved it (control: 89 ± 2%; IR: 24 ± 1%; IR + DuraGraft: 48 ± 1%, p < 0.05). Immunohistochemical analysis revealed decreased intercellular adhesion molecule-1, 4-hydroxy-2-nonenal, caspase-3 and caspase-8 expression, while endothelial cell adhesion molecule-1 immunoreactivity was increased in the IR + DuraGraft grafts compared to the IR-group. DuraGraft mitigates endothelial dysfunction following IR injury in a rat bypass model. Its protective effect may be attributed, at least in part, to its ability to reduce the inflammatory response, oxidative stress, and apoptosis. [ABSTRACT FROM AUTHOR]

Background: Syndecan‐1 (SDC1) is an established marker of endothelial glycocalyx shedding. Most research on SDC1 has focused on plasma or serum concentrations, and little is known about urine concentrations. Objectives: Measure urinary SDC1 concentrations in dogs undergoing anesthesia with either sevoflurane or isoflurane and assess the effects of anesthesia duration and IV crystalloids on urinary SDC1 concentrations. Animals: Thirty‐one client‐owned dogs undergoing anesthesia for magnetic resonance imaging (MRI) with or without surgery for suspected intervertebral disk disease (IVDD) were used. Methods: Dogs with suspected IVDD were randomized to undergo anesthesia with either sevoflurane or isoflurane. Urine was collected before and immediately after anesthesia for the analysis of SDC1. Urinary creatinine concentrations also were measured, and the ratio of urinary SDC1 to urinary creatinine (USCR) was used to account for dilution. Results: Median (range) USCR was significantly higher after anesthesia compared with baseline for all groups combined (P <.05). No significant difference was found between the groups for age, sex, weight, and type of anesthesia. Multiple regression analysis of the effect of the independent variables inhalant type, age, weight, sex, anesthesia time, surgery, and quantity of IV fluids on the dependent variable SDC1 found that only the quantity of IV fluids significantly predicted a change (P <.001). Conclusions and Clinical Importance: The total volume of lactated Ringer's solution administered to anesthetized dogs may affect USCR. Further investigations are warranted to evaluate the relationship between IV fluids and SDC1. [ABSTRACT FROM AUTHOR]

Introduction: Blood pressure (BP) variability (BPV) has emerged as an indicator of subclinical organ damage and an independent predictor of cardiovascular disease (CVD) morbidity and mortality in high-risk populations. Aim: We aimed to assess short-term variability of both brachial and aortic BP in psoriasis, a common immune-mediated inflammatory disorder characterized by increased CVD risk. Methods: Psoriasis patients and non-psoriasis individuals had their BP assessed throughout a 24 h period (Mobil-O-Graph device). Brachial and aortic BPV during the 24 h and the respective daytime and nighttime periods was calculated from relevant ambulatory BP profiles. In-house software was applied to automatically calculate average real variability (ARV) of brachial and aortic systolic (bSBP, aSBP) and diastolic BP (bDPB, aDBP), and the weighted standard deviation (wSD) of 24 h bSBP/aSBP. 24 h pulse wave velocity (PWV) and augmentation index (AIx) were used as widely applied markers of arterial stiffness. Results: Psoriasis patients (n = 74) presented increased ARV of 24 h and daytime bSBP/aSBP, and increased ARV of 24 h and daytime bDBP/aDBP, compared to controls (n = 40). PWV and AIx correlated with ARV of 24 h bSBP/aSBP, daytime bSBP/aSBP, while PWV further correlated with ARV of nighttime aSBP. The observed associations with PWV, yet not AIx, with indices of BPV remained significant after adjusting for CVD risk factors. Conclusions: This is the first study reporting increased 24 h variability of both brachial and aortic BP in psoriasis. The association of short-term BPV with arterial stiffness implies a potential role of BPV in terms of CVD risk stratification in patients with chronic immune-mediated inflammation. [ABSTRACT FROM AUTHOR]