Ang-2 Levels Research Articles

Pathophysiological Markers of Acute Respiratory Distress Syndrome Severity Are Correlated With Ventilation-Perfusion Mismatch Measured by Electrical Impedance Tomography.

Pulmonary ventilation/perfusion (V/Q) mismatch measured by electrical impedance tomography (EIT) is associated with the outcome of patients with the acute respiratory distress syndrome (ARDS), but the underlying pathophysiological mechanisms have not been fully elucidated. The present study aimed to verify the correlation between relevant pathophysiological markers of ARDS severity and V/Q mismatch. Prospective observational study. General ICU of a university-affiliated hospital. Deeply sedated intubated adult patients with ARDS under controlled mechanical ventilation. Measures of V/Q mismatch by EIT, respiratory mechanics, gas exchange, lung imaging, and plasma biomarkers. Unmatched V/Q units were assessed by EIT as the fraction of ventilated nonperfused plus perfused nonventilated lung units. At the same time, plasma biomarkers with proven prognostic and mechanistic significance for ARDS (carbonic anhydrase 9 [CA9], hypoxia-inducible factor 1 [HIF1], receptor for advanced glycation endproducts [RAGE], angiopoietin 2 [ANG2], gas exchange, respiratory mechanics, and quantitative chest CT scans were measured. Twenty-five intubated ARDS patients were included with median unmatched V/Q units of 37.1% (29.2-49.2%). Unmatched V/Q units were correlated with plasma levels of CA9 (rho = 0.47; p = 0.01), HIF1 (rho = 0.40; p = 0.05), RAGE (rho = 0.46; p = 0.02), and ANG2 (rho = 0.42; p = 0.03). Additionally, unmatched V/Q units correlated with plateau pressure (r = 0.38; p = 0.05) and with the number of quadrants involved on chest radiograph (r = 0.73; p < 0.01). Regional unmatched V/Q units were correlated with the corresponding fraction of poorly aerated lung tissue (r = 0.62; p = 0.01) and of lung tissue weight (rho: 0.51; p = 0.04) measured by CT scan. In ARDS patients, unmatched V/Q units are correlated with pathophysiological markers of lung epithelial and endothelial dysfunction, increased lung stress, and lung edema. Unmatched V/Q units could represent a comprehensive marker of ARDS severity, reflecting the complex organ pathophysiology and reinforcing their prognostic significance.

Comprehensive biomarker and modeling approach to support dose finding for BI 836880, a VEGF/Ang-2 inhibitor

BackgroundBI 836880 is a humanized bispecific nanobody® that binds to and blocks vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2). A comprehensive biomarker and modeling approach is presented here that supported dose finding for BI 836880.MethodsTwo Phase I dose-escalation studies (1336.1 [NCT02674152], 1336.6 [NCT02689505]) assessed BI 836880 in adults with confirmed locally advanced or metastatic solid tumors, refractory to standard therapy or for which standard therapy was not reliably effective. Two dosing schedules were investigated, 3 weeks (q3w) or once weekly (qw), starting at a dose of 40 mg. In a comprehensive biomarker approach, soluble pharmacodynamic markers (free and total plasma VEGF-A and Ang-2), as well as circulating angiogenic factors (soluble VEGF3, soluble Tie2 and placenta growth factor, amongst others) were analyzed to assess target engagement in peripheral blood for q3w doses. A Population based pharmacokinetics/pharmacodynamics (PopPK/PD) model was built using the limited Phase I dataset to support dose finding by simulations. In order to demonstrate drug activity in the tumor, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was applied.ResultsDCE-MRI scans supported target engagement in the tumor. Free VEGF-A was depleted at all doses, whereas free Ang-2 decreased dose-dependently, reaching depletion in most patients from 360 mg q3w onwards. While total VEGF-A levels increased in a dose-dependent manner, reaching saturation at 360 mg q3w, total Ang-2 levels increased, but did not plateau. Angiogenic biomarkers showed changes from doses ≥ 360 mg q3w. PopPK/PD modeling showed that doses ≥ 360 mg q3w led to > 90% inhibition of free Ang-2 at steady-state in most patients. By increasing the dose to ≥ 500 mg q3w, > 90% of patients are expected to achieve this level.ConclusionsThe comprehensive analyses of multiple target engagement markers support BI 836880 720 mg q3w as a biologically relevant monotherapy dose schedule.Trial registration: NCT02674152 and NCT02689505.

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).

The effect of fibroblast growth factor 2 on neovascular vessels depends on the stage of angiogenesis.

ObjectiveThe exact relationship between fibroblast growth factor 2 (FGF2) and choroidal neovascularization (CNV) remains unclear. In this study, using optical coherence tomography angiography (OCTA) and FGF2-tg mice which are transgenic mice with a rhodopsin promoter/FGF2 gene fusion, we aimed to investigate the dynamics of FGF2's role in angiogenesis over time. MethodsWe developed laser-induced CNV models of FGF2-tg and wild-type (WT) mice and then separated them into two groups using different laser photocoagulation (PC) conditions. The first group received 3 intense PC shots (1st PC) altogether (one-time PC group), while the other group received 3 intense PC shots (1st PC) followed by 6 additional weak PC shots (2nd PC) on the 7th day after 1st PC (two-times PC group). ResultsUsing OCTA to observe vessel changes within the same individual over time, there was no difference in the timing of vessel transition from the CNV development phase to the CNV regression phase between FGF2-tg and WT mice in the one-time PC group. In contrast, the neovascular vessels in the two-times PC group of FGF2-tg mice were maintained at least 28 days post-2nd PC without regression. In addition, mature vessels surrounded by PDGFRβ positive pericytes and α-SMA positive smooth muscle cells were observed. Real-time qPCR showed a substantial increase in apelin mRNA expression in the one-time PC group of FGF2-tg, rather than VEGF-A (p<0.05, n=5 or 6). Moreover, the expression levels of PDGFRβ, apelin, and Ang1 were significantly higher in FGF2-tg mice of two-times PC group than in WT mice (p<0.05, n=5 or 6). ConclusionsFGF2 not only promotes neovascularization via the apelin/APJ system, which is independent of VEGF signaling pathway, but also helps maintain and stabilize pre-existing neovascular vessels by stimulating PDGFRβ and Ang1. The effect of FGF2 on the neovascular vessels depends on the stage of angiogenesis.

Study on the correlation between angiopoietin-2 and prognosis in patients with acute respiratory distress syndrome

To evaluate the predictive value of angiopoietin-2 (Ang-2) for the prognosis in patients with acute respiratory distress syndrome (ARDS). A retrospective study was conducted, and ARDS patients admitted to the department of emergency medicine of Tongde Hospital of Zhejiang Province from December 2020 to September 2022 were enrolled. General information including gender, age, causes of ARDS, disease severity scores, plasma Ang-2 levels before treatment and at 24, 48, and 72 hours after treatment, and record the 60-day prognosis were collected. Differences in clinical data between groups were compared. Multivariate Logistic regression analysis was used to identify the independent risk factors affecting the 60-day prognosis of ARDS patients, and the receiver operator characteristic curve (ROC curve) was plotted to assess the predictive value of these risk factors for patient outcomes. Pearson correlation analysis was used to assess the correlation between Ang-2 and pulmonary vascular permeability index (PVPI) and extravascular lung water index (EVLWI). A total of 132 ARDS patients were included, of which 49 patients died within 60 days and 83 patients survived. In the death group, plasma Ang-2 levels showed a gradually increasing trend, all significantly higher than before treatment (μg/L: 12.75±1.81, 12.74±1.48, 13.45±2.21 vs. 5.98±0.57, all P < 0.05), while the trend in the survival group was not significant. At 24, 48, and 72 hours after treatment, plasma Ang-2 levels in the death group were significantly higher than those in the survival group (μg/L: 12.75±1.81 vs. 7.48±1.22, 12.74±1.48 vs. 7.41±1.19, 13.45±1.41 vs. 6.88±1.41, all P < 0.05). After adjusting for confounding variables, increased plasma Ang-2 level was an independent risk factor for prognosis in ARDS patients within 60 days [odds ratio (OR) = 0.998, 95% confidence interval (95%CI) was 0.997-0.999, P < 0.01]. ROC curve analysis demonstrated that Ang-2 levels had predictive value for prognosis in ARDS patients [area under the ROC curve (AUC) = 0.985, 95%CI was 0.971-1.000, approximate maximum Youden's index 0.867, optimal cut-off value 8.43 μg/L]. Pearson correlation analysis showed that plasma Ang-2 levels were positively correlated with PVPI and EVLWI ( r values were 0.620 and 0.712 respectively, both P < 0.01). Elevated level of Ang-2 is an independent risk factor for increased mortality in patients with ARDS. Higher Ang-2 levels within 72 hours after treatment may indicate poorer prognosis.

Shenfu injection ameliorates endotoxemia-associated endothelial dysfunction and organ injury via inhibiting PI3K/Akt-mediated glycolysis

Ethnopharmacological relevanceMicrocirculatory dysfunction is one of the main characteristics of sepsis. Shenfu Injection (SFI) as a traditional Chinese medicine is widely applied in clinical severe conditions. Recent studies have shown that SFI has the ability to ameliorate sepsis-induced inflammation and to improve microcirculation perfusion. Aim of the studyThis study aims to investigate the underlying mechanism of SFI for ameliorating sepsis-associated endothelial dysfunction and organ injury. Materials and methodsSide-stream dark-field (SDF) imaging was used to monitor the sublingual microcirculation of septic patients treated with or without SFI. Septic mouse model was used to evaluate the effects of SFI in vivo. Metabolomics and transcriptomics were performed on endothelial cells to identify the underlying mechanism for SFI-related protective effect on endothelial cells. ResultsSFI effectively abolished the disturbance and loss of sublingual microcirculation in septic patients. Twenty septic shock patients with or without SFI administration were enrolled and the data showed that SFI significantly improved the levels of total vessel density (TVD), perfused vessel density (PVD), microvascular flow index (MFI), and the proportion of perfused vessels (PPV). The administration of SFI significantly decreased the elevated plasma levels of Angiopoietin-2 (Ang2) and Syndecan-1, which are biomarkers indicative of endothelial damage in sepsis patients. In the mouse septic model in vivo, SFI inhibited the upregulation of endothelial adhesion molecules and Ly6G + neutrophil infiltration while restored the expression of VE-Cadherin in the vasculature of the lung, kidney, and liver tissue. Additionally, SFI reduced the plasma levels of Ang2, Monocyte Chemoattractant Protein-1(MCP1), and Interleukin-6 (IL6), and alleviated liver and kidney injury in septic mice. Moreover, SFI significantly inhibited the inflammatory activation and increased permeability of endothelial cells induced by endotoxins in vitro. By performing metabolomics and transcriptomics, we identified the activation of PI3K/Akt-mediated glycolysis as the underlying mechanism for SFI-related protective effect on endothelial cells. ConclusionsOur findings revealed that SFI may improve microcirculation perfusion and endothelial function in sepsis via inhibiting PI3K/Akt-mediated glycolysis, providing theoretical evidence for the clinical application of SFI.

Association of cord blood Ang-1 and sCD105 levels with bronchopulmonary dysplasia in preterm infants

BackgroundTo investigate the relationship between cord blood levels of Angiopoietin-1 (Ang-1) and S-endoglin (sCD105) and bronchopulmonary dysplasia (BPD) in preterm infants.MethodsSixty-one preterm infants admitted to the neonatal intensive care unit of the study hospital between July 2021 and September 2022 were included. Cord blood was collected after the birth of premature infants. Ang-1 and sCD105 levels were quantified using the vascular endothelial growth factor enzyme-linked immunosorbent assay. Preterm infants were divided into BPD and non-BPD groups, and differences in Ang-1 and sCD105 levels between the two groups were compared. A binary logistic model was used to assess the association between low and high levels Ang-1 and BPD in preterm infants.ResultsIn the study, there were 20 preterm infants with BPD (32.8%) and 41 preterm infants with non-BPD (67.2%). Ang-1 concentration levels were lower in the BPD group than in the non-BPD group (7105.43 (5617.01–8523.00) pg/ml vs. 10488.03 (7946.19–15962.77) pg/ml, P = 0.027). However, the sCD105 concentration levels were not significantly different between the BPD and non-BPD groups (P = 0.246). A median Ang-1 concentration of 8800.40 pg/ml was calculated. Logistic regression analysis showed that after adjusting for gestational age, birth weight, and maternal prenatal steroid hormone application, the odds ratio (OR) was 8.577 for the risk of BPD in preterm infants with Ang-1 concentrations of ≤ 8800.40 pg/ml compared to those with Ang-1 concentrations of > 8800.40 pg/ml (OR: 8.577, 95% confidence interval: 1.265–58.155, P = 0.028).ConclusionOur study indicated that Ang-1 levels in the cord blood of preterm infants may be associated the risk of BPD. In the future, we will continue to conduct study with large samples.

Angiopoietin-2 as a Predictor of Fibrosis Regression in Hepatitis C Virus-Patients after Direct Acting Antiviral Drugs

Abstract Background HCV infection is a major health concern. Disease progression to fibrosis, cirrhosis, and HCC is aided by the persistence of inflammatory reactions and cellular damage. Moreover, angiogenesis was found to have a substantial pathogenic role in disease progression. Serum Angiopoietin-2 appears to be correlated with liver stiffness in chronic HCV and its elevation is linked to disease progression from chronic hepatitis to cirrhosis. Aim of the Work The aim of this study was to evaluate the role of serum Angiopoietin-2 in the prediction of regression of fibrosis in chronic HCV patients receiving direct-acting antiviral agents. Patients and Methods Forty Egyptian chronic HCV patients for whom direct-acting antiviral agent (DAA) therapy was planned were included. All patients underwent assessment twice, at baseline and at SVR12, for standard laboratory tests, measurement of fibrosis using FibroScan, FIB-4 and APRI scores, and Angiopoietin-2 level. Results Among 40 patients; 26 (65%) are males and 14 (35%) are females. Their age is ranged between 35 and 60 years old with a mean age of 52.35 ± 6.08 and a median of 53.0 (50.0 – 57.0). The HCV-RNA titer is ranged from 3.60 to 7.20 log IU/mL with a mean titer of 5.99 ± 0.87 before treatment. The median is 6.20 (5.30 – 6.65). There was a significant improvement concerning the fibrosis stage after DAA treatment. Liver fibrosis indices were significantly associated with regression of liver fibrosis stage based on FibroScan data after DAA therapy. Liver size, spleen size and portal vein diameter were improved significantly after successful HCV eradication by DAAs. There was improvement in the Child-Pugh score after successful HCV eradication by DAAs but the difference was no statistically significant (p = 0.500). Baseline Ang-2 was statistically significant after successful HCV eradication by DAAs (p &amp;lt; 0.001). Overall, there was a positive significant correlation between Ang-2 and all the fibrosis stages (p = 0.001) and there was a statistically significant higher mean of Ang-2 in higher stages of liver fibrosis before treatment. Indeed Ang-2 increase significantly when the fibrosis stage increased and vice-versa before treatment. Ang-2 in higher stages of liver fibrosis after treatment. Indeed Ang-2 increase significantly when the fibrosis stage increased and vice-versa after treatment. The correlation between Ang-2 and fibrosis group (F0, F1, F2 &amp; F3) were significant and the correlation between Ang-2 and the liver fibrosis stage (F4) were also significant before treatment. The correlations between Ang-2 levels and fibrosis group (F0, F1, F2 &amp; F3) were significant as well as the advanced liver fibrosis (F4) after DAA therapy. Conclusion Angiopoietin-2 can be a useful predictor of fbrosis regression in chronic HCV patients receiving direct acting antiviral agents. Elevated baseline Angiopoietin-2 and advanced ibrosis stages may predict non-regression of liver fibrosis.

Promotion of mature angiogenesis in ischemic stroke by Taohong Siwu decoction through glycolysis activation.

Backgrounds: Mature angiogenesis plays a critical role in improving cerebral ischemia-reperfusion injury (CIRI). Glycolysis serves as the primary energy source for brain microvascular endothelial cells (BMECs), whereas other vascular cells rely on aerobic respiration. Therefore, intercellular variations in energy metabolism could influence mature angiogenesis. Taohong Siwu Decoction (THSWD) has demonstrated efficacy in treating ischemic stroke (IS), yet its potential to promote mature angiogenesis through glycolysis activation remains unclear. Methods: In this study, we established a middle cerebral artery occlusion/reperfusion (MCAO/R) model in vivo and an oxygen-glucose deprivation/reoxygenation (OGD/R) model in vitro. We assessed neuroprotective effects using neurobehavioral scoring, 2,3,5-triphenyltetrazolium chloride (TTC) staining, Hematoxylin-eosin (HE) staining, and Nissl staining in MCAO/R rats. Additionally, we evaluated mature angiogenesis and glycolysis levels through immunofluorescence, immunohistochemistry, and glycolysis assays. Finally, we investigated THSWD's mechanism in linking glycolysis to mature angiogenesis in OGD/R-induced BMECs. Results: In vivo experiments demonstrated that THSWD effectively mitigated cerebral damage and restored neurological function in MCAO/R rats. THSWD significantly enhanced CD31, Ang1, PDGFB, and PDGFR-β expression levels, likely associated with improved glucose, pyruvate, and ATP levels, along with reduced lactate and lactate/pyruvate ratios. In vitro findings suggested that THSWD may boost the expression of mature angiogenesis factors (VEGFA, Ang1, and PDGFB) by activating glycolysis, increasing glucose uptake and augmenting lactate, pyruvate, and ATP content, thus accelerating mature angiogenesis. Conclusion: THSWD could alleviate CIRI by activating the glycolysis pathway to promote mature angiogenesis. Targeting the glycolysis-mediated mature angiogenesis alongside THSWD therapy holds promise for IS treatment.

Prognostic value of circulatory growth factors to predict responsiveness to chemotherapy and remission status of patients with acute myeloid leukemia

IntroductionTumor neovascularization, an essential requirement for malignant disease progression and metastasis, depends on the dysregulation of pro-angiogenic and anti-angiogenic activities. This study aimed to investigate the utilization of circulatory angiopoietins (Ang-1 and Ang-2), vascular endothelial growth factor (VEGF-A and VEGF-C), and basic fibroblast growth factor (bFGF) as a prognostic tool for acute myeloid leukemia (AML).Material and methodsTwenty-four AML patients who were under chemotherapeutic intervention were included. Patients’ relapse status, responsiveness to chemotherapy, and remission status were obtained from their medical profiles. For comparative purposes, fifteen healthy subjects were included. Serum levels of growth factors were measured.ResultsAs compared to control subjects, AML patients had significantly lower average levels of Ang-1 (170.8 ±12.7 versus 59.2 ±12.5 ng/ml) and VEGF-A (56.0 ±13.1 versus 98.6 ±11.9 ng/dl) that coincide with a higher average level of Ang-2 (18.5 ±4.1 ng/ml versus 7.5 ±0.8 ng/ml). Spearman’s correlation analysis defined a significant association of sAng-1 and sAng-2 with patients’ response to chemotherapy ( = 0.488) and remission status ( = 0.476), respectively. According to the receiver operating characteristic (ROC) curve, downregulation of Ang-1 has good predictivity for poor responsiveness to chemotherapy (AUC = 0.781, p &lt; 0.05) while upregulation of sAng-2 has good predictivity for failed remission status (AUC = 0.779, p &lt; 0.05).ConclusionsIn the context of AML, dysregulated circulatory levels of Ang-1 and Ang-2 are suggested prognostic markers to provide useful predictivity of patients’ adverse responsiveness to chemotherapy and remission status, respectively.

Swimming training induced sex-specific differences in cardiac hypertrophy and blood levels of the renin-angiotensin system

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): FNS Background Exercise promotes physiological cardiac hypertrophy that is adaptive and reversible and influenced by age, genetics, sex, exercise intensity and type. The renin-angiotensin system (RAS) plays a crucial role in cardiovascular remodelling at both systemic and tissue levels. However, a significant gap exists in our understanding of sex differences in response to physical activity. Our objective is to characterise swimming-induced cardiac remodelling in female and male rats and RAS at both the cardiac tissue and systemic levels. Methods Male and female Lewis rats swam in a container filled with tap water at 32° C for 1 hour per day for 4 weeks or up to 8 weeks, respectively. Sedentary animals served as control. Echocardiography and immunostaining of RAS components, including angiotensin-converting enzyme 2 (ACE2) on cardiac sections' staining were performed. Cardiomyocyte (CM) size was measured. Cardiac RAS receptors were quantified with RT-PCR. Blood levels of Angiotensinogen, Angiotensins (Ang) were measured with Mass Spectrometry. Renin activity was calculated by the ratio Ang1/Angiotensinogen. Results After 4 weeks, an increase in ventricle diameter was shown in exercised male rats compared to the control. The cardiac hypertrophy was confirmed by increased heart/body weight (H/BW= 3x10-3±1.3x10-4vs2.5x10-3±3.10-5mg/g p&amp;lt;0.0001) and CM size (288±23 vs 198±1μm2 p=0.0028) associated with increased intra-CM immunostained ACE2 (AC2 area fraction: 38.5%±2.8%vs20%±5 p=0.0001). In females, ventricle diameter was unchanged, but wall thickness increased. Exercise was pursued for up to 8 weeks. At 6 and 8 weeks, echocardiography measurements remained similar as at 4 weeks. Hypertrophy was then confirmed by increased H/BW (3.2x10-3±1.7x10-4vs control:2.7x103 ±1.8x104mg/g p&amp;lt;0.0001) and CM size (335±47vs233±25μm2 p= 0.0019). An increased intra-CM-ACE2 was characterised by immunostaining (55.8%±6vs32.5%±6.6% p&amp;lt;0.0001) and confirmed by the increased ACE2 gene expression in cardiac tissue. At 4 weeks, the blood levels of RAS components were similar in trained and control males as well as renin activity. On contrary, exercised female rats showed increased blood levels of Angiotensinogen (4.2x10-4±7x10-5 vs 3x10-4±7x10-5au p=0.0288), Ang1 (2±1.9vs0.0±0.9au p=0.0151), Ang2 (1.2±1.5vs0.0±0.9au p=0.0204), and Ang1-7 (3.4±2.9vs 0.0±0.9au p=0.0058). The blood levels of these RAS compounds returned to the control levels after 6 and 8 weeks. In addition, a sex-distinct blood proteome was identified. Conclusion Our results showed a sex-distinct RAS regulation post-exercise and suggested a sex difference in the timing of adaptive responses at the system and cardiac tissue levels.

Angiogenesis-associated pathways play critical roles in neonatal sepsis outcomes

Neonatal sepsis is a major cause of childhood mortality. Limited diagnostic tools and mechanistic insights have hampered our abilities to develop prophylactic or therapeutic interventions. Biomarkers in human neonatal sepsis have been repeatedly identified as associated with dysregulation of angiopoietin signaling and altered arachidonic acid metabolism. We here provide the mechanistic evidence in support of the relevance for these observations. Angiopoetin-1 (Ang-1), which promotes vascular integrity, was decreased in blood plasma of human and murine septic newborns. In preclinical models, administration of Ang-1 provided prophylactic protection from septic death. Arachidonic acid metabolism appears to be functionally connected to Ang-1 via reactive oxygen species (ROS) with a direct role of nitric oxide (NO). Strengthening this intersection via oral administration of arachidonic acid and/or the NO donor L-arginine provided prophylactic as well as therapeutic protection from septic death while also increasing plasma Ang-1 levels among septic newborns. Our data highlight that targeting angiogenesis-associated pathways with interventions that increase Ang-1 activity directly or indirectly through ROS/eNOS provide promising avenues to prevent and/or treat severe neonatal sepsis.

Exosomal EGFR and miR-381-3P Mediate HPV-16 E7 Oncoprotein-Induced Angiogenesis of Non-Small Cell Lung Cancer.

It has been demonstrated that exosomes derived from HPV-16 E7-over-expressiong non-small cell lung cancer (NSCLC) cells (E7 Exo) trigger increased levels of epidermal growth factor receptor (EGFR) and miR-381-3p. The purpose of this investigation was to examine the role of E7 Exo in NSCLC angiogenesis, and to analyze the contribution of exosomal EGFR and miR-381-3p to it. The influence of E7 Exo on the proliferation and migration of human umbilical vein endothelial cells (HUVECs) was assessed using colony formation and transwell migration assays. Experiments on both cells and animal models were conducted to evaluate the angiogenic effect of E7 Exo treatment. The involvement of exosomal EGFR and miR-381-3p in NSCLC angiogenesis was further investigated through suppressing exosome release or EGFR activation, or by over-expressing miR-381-3p. Treatment with E7 Exo increased the proliferation, migration, and tube formation capacities of HUVECs, as well as angiogenesis in animal models. The suppression of exosome release or EGFR activation in NSCLC cells decreased the E7-induced enhancements in HUVEC migration and tube formation, and notably reduced vascular endothelial growth factor A (VEGFA) and Ang-1 levels. HUVECs that combined miR-381-3p mimic transfection and E7 Exo treatment exhibited a more significant tube-forming capacity than E7 Exo-treated HUVECs alone, but were reversed by the miR-381-3p inhibitor. The angiogenesis induced by HPV-16 E7 in NSCLC is mediated through exosomal EGFR and miR-381-3p.

NRASQ61R mutation drives elevated angiopoietin-2 expression in human endothelial cells and a genetic mouse model.

Angiopoietin-2 (Ang-2) is increased in the blood of patients with kaposiform lymphangiomatosis (KLA) and kaposiform hemangioendothelioma (KHE). While the genetic causes of KHE are not clear, a somatic activating NRASQ61R mutation has been found in the lesions of KLA patients. Our study tested the hypothesis that the NRASQ61R mutation drives elevated Ang-2 expression in endothelial cells. Ang-2 was measured in human endothelial progenitor cells (EPC) expressing NRASQ61R and a genetic mouse model with endothelial targeted NRASQ61R. To determine the signaling pathways driving Ang-2, NRASQ61R EPC were treated with signaling pathway inhibitors. Ang-2 levels were increased in EPC expressing NRASQ61R compared to NRASWT by Western blot analysis of cell lysates and ELISA of the cell culture media. Ang-2 levels were elevated in the blood of NRASQ61R mutant mice. NRASQ61R mutant mice also had reduced platelet counts and splenomegaly with hypervascular lesions, like some KLA patients. mTOR inhibitor rapamycin attenuated Ang-2 expression by NRASQ61R EPC. However, MEK1/2 inhibitor trametinib was more effective blocking increases in Ang-2. Our studies show that the NRASQ61R mutation in endothelial cells induces Ang-2 expression in vitro and in vivo. In cultured human endothelial cells, NRASQ61R drives elevated Ang-2 through MAP kinase and mTOR-dependent signaling pathways.

PASC (Post Acute Sequelae of COVID-19) is associated with decreased neutralizing antibody titers in both biological sexes and increased ANG-2 and GM-CSF in females.

Post-acute sequelae of COVID-19 (PASC) or the continuation of COVID-19 (Coronavirus disease 2019) symptoms past 12weeks may affect as many as 30% of people recovering from a SARS-CoV-2 (severe acute respiratory coronavirus 2) infection. The mechanisms regulating the development of PASC are currently not known; however, hypotheses include virus reservoirs, pre-existing conditions, microblood clots, immune dysregulation, as well as poor antibody responses. Importantly, virus neutralizing antibodies are essential for COVID-19 recovery and protection from reinfection but there is currently limited information on these immune regulators and associated cytokines in PASC patients. Understanding the key drivers of general and specific symptoms associated with Long COVID and the presence of virus neutralizing antibodies in PASC will aid in the development of therapeutics, diagnostics, and vaccines which currently do not exist. We designed a cross-sectional study to investigate systemic antibody and cytokine responses during COVID-19 recovery and PASC. In total, 195 participants were recruited in one of four groups: (1) Those who never had COVID-19 (No COVID); (2) Those in acute COVID-19 recovery (Acute Recovery) (4-12weeks post infection); (3) Those who recovered from COVID-19 (Recovered) (+ 12weeks from infection); and (4) those who had PASC (PASC) (+ 12weeks from infection). Participants completed a questionnaire on health history, sex, gender, demographics, experiences with COVID-19 acute and COVID-19 recovery/continuing symptoms. Serum samples collected were evaluated for antibody binding to viral proteins, virus neutralizing antibody titers, and serum cytokine levels using Ella SimplePlex Immunoassay™ panels. We found participants with PASC reported more pre-existing conditions (e.g. such as hypertension, asthma, and obesity), and PASC symptoms (e.g. fatigue, brain fog, headaches, and shortness of breath) following COVID-19 than COVID-19 Recovered individuals. Importantly, we found PASC individuals to have significantly decreased levels of neutralizing antibodies toward both SARS-CoV-2 and the Omicron BA.1 variant. Sex analysis indicated that female PASC study participants had sustained antibody levels as well as levels of the inflammatory cytokines GM-CSF and ANG-2 over time following COVID-19. Our study reports people experiencing PASC had lower levels of virus neutralizing antibodies; however, the results are limited by the collection time post-COVID-19 and post-vaccination. Moreover, we found females experiencing PASC had sustained levels of GM-CSF and ANG-2. With lower levels of virus neutralizing antibodies, this data suggests that PASC individuals not only have had a suboptimal antibody response during acute SARS-CoV-2 infection but may also have increased susceptibility to subsequent infections which may exacerbate or prolong current PASC illnesses. We also provide evidence suggesting GM-CSF and ANG-2 to play a role in the sex-bias of PASC. Taken together, our findings maybe important for understanding immune molecular drivers of PASC and PASC subgroups.

Angiopoietins as Predictor Indexes in COVID-19 Patients in Delta and Omicron Waves.

This study aimed to explore the correlation between Angiopoietin-1 (Ang-1) and Angiopoietin-2 (Ang-2) concentrations and the Angiopoietin-2/Angiopoietin-1 ratio (Ang-2/Ang-1) with clinical outcomes, potentially serving as disease severity and survival biomarkers. A study at AHEPA University Hospital involved 90 Coronavirus Disease 2019 (COVID-19) adult patients, 30 hospitalized intensive care units (ICU), 30 inward units (non-ICU), and 30 asymptomatic non-hospitalized individuals as controls. Estimated endothelial dysfunction markers related to angiogenesis were measured. There was a statistically significant difference only between outpatient and hospitalized patients (non-ICU-ICU groups) for the Ang-1 and Ang-2 indices. The Ang-2/Ang-1 ratio has differed significantly among the individual patient groups. An ROC analysis was conducted to find an optimal threshold for distinguishing between (outpatients-non-ICU) and (non-ICU-ICU) groups. It was based on Youden's index of 0.1122 and 0.3825, respectively. The Ang-1, Ang-2 levels, and Ang-2/Ang-1 ratio were analyzed as severity indicators in COVID-19 patients. The Ang-2/Ang-1 ratio demonstrated better prognostic and diagnostic utility than individual biomarker levels. Monitoring the Ang-2/Ang-1 ratio can identify COVID-19 patients at risk and assist clinicians in tailoring treatment strategies to improve outcomes.

Angiopoietin-2 and Angiopoietin-like Proteins with a Prospective Role in Predicting Diabetic Nephropathy.

Angiopoietins are crucial growth factors for maintaining a healthy, functional endothelium. Patients with type 2 diabetes (T2D) exhibit significant levels of angiogenic markers, particularly Angiopoietin-2, which compromises endothelial integrity and is connected to symptoms of endothelial injury and failure. This report examines the levels of circulating angiopoietins in people with T2D and diabetic nephropathy (DN) and explores its link with ANGPTL proteins. We quantified circulating ANGPTL3, ANGPTL4, ANGPTL8, Ang1, and Ang2 in the fasting plasma of 117 Kuwaiti participants, of which 50 had T2D and 67 participants had DN. The Ang2 levels increased with DN (4.34 ± 0.32 ng/mL) compared with T2D (3.42 ± 0.29 ng/mL). This increase correlated with clinical parameters including the albumin-to-creatinine ratio (ACR) (r = 0.244, p = 0.047), eGFR (r = -0.282, p = 0.021), and SBP (r = -0.28, p = 0.024). Furthermore, Ang2 correlated positively to both ANGPTL4 (r = 0.541, p < 0.001) and ANGPTL8 (r = 0.41, p = 0.001). Multiple regression analysis presented elevated ANGPTL8 and ACRs as predictors for Ang2's increase in people with DN. In people with T2D, ANGPTL4 positively predicted an Ang2 increase. The area under the curve (AUC) in receiver operating characteristic (ROC) analysis of the combination of Ang2 and ANGPTL8 was 0.77 with 80.7% specificity. In conclusion, significantly elevated Ang2 in people with DN correlated with clinical markers such as the ACR, eGFR, and SBP, ANGPTL4, and ANGPTL8 levels. Collectively, this study highlights a close association between Ang2 and ANGPTL8 in a population with DN, suggesting them as DN risk predictors.

Effect of Xuming Decoction in Records of Proved Prescriptions, Ancient a nd Modern on cerebral ischemic injury and angiogenesis in rat model of acute cerebral infarction

This paper aims to explore the effect of Xuming Decoction in the Records of Proved Prescriptions, Ancient and Modern on cerebral ischemic injury and angiogenesis in the rat model of acute cerebral infarction. SD rats were randomized into 6 groups: sham group, model group, low-, medium-, and high-dose(5.13, 10.26, and 20.52 g·kg~(-1), respectively) Xuming Decoction groups, and butylphthalide(0.06 g·kg~(-1)) group. After the successful establishment of the rat model by middle cerebral artery occlusion(MCAO), rats in the sham and model groups were administrated with distilled water and those in other groups with corresponding drugs for 7 consecutive days. After the neurological function was scored, all the rats were sacrificed, and the brain tissue samples were collected. The degree of cerebral ischemic injury was assessed by the neurological deficit score and staining with 2,3,5-triphenyltetrazolium chloride. Hematoxylin-eosin staining was performed to observe the pathological changes in the brain. Transmission electron microscopy was employed to observe the ultrastructures of neurons and microvascular endothelial cells(ECs) on the ischemic side of the brain tissue. Immunofluorescence assay was employed to detect the expression of von Willebrand factor(vWF) and hematopoietic progenitor cell antigen CD34(CD34) in the ischemic brain tissue. Real-time PCR and Western blot were employed to determine the mRNA and protein levels, respectively, of Runt-related transcription factor 1(RUNX1), vascular endothelial growth factor(VEGF), angiopoietin-1(Ang-1), angiopoietin-2(Ang-2), and VEGF receptor 2(VEGFR2) in the ischemic brain tissue. The results showed that compared with the sham group, the model group showed increased neurological deficit score and cerebral infarction area(P&lt;0.01), pathological changes, and damaged ultrastructure of neurons and microvascular ECs in the ischemic brain tissue. Furthermore, the modeling up-regulated the mRNA levels of RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P&lt;0.01) and the protein levels of vWF, CD34, RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P&lt;0.05 or P&lt;0.01). Compared with the model group, high-dose Xuming Decoction and butylphthalide decreased the neurological deficit score and cerebral infarction area(P&lt;0.01) and alleviated the pathological changes and damage of the ultrastructure of neurons and microvascular ECs in the ischemic brain tissue. Moreover, they up-regulated the mRNA levels of RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P&lt;0.01) and the protein levels of vWF, CD34, RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P&lt;0.01). The results suggest that Xuming Decoction in the Records of Proved Prescriptions, Ancient and Modern can promote the angiogenesis and collateral circulation establishment to alleviate neurological dysfunction of the ischemic brain tissue in MCAO rats by regulating the RUNX1/VEGF pathway.

Myxomatous mitral valve disease and associated pulmonary hypertension might increase serum angiopoietin-2 in dogs.

To evaluate the relationships between the severity of myxomatous mitral valve disease (MMVD) and pulmonary hypertension (PH) and serum angiopoietin (Ang)-1 and Ang-2 concentrations in dogs with MMVD. 74 dogs (control, n = 12; MMVD, n = 62) were included. Serum Ang-1 and Ang-2 concentrations were estimated using the canine-specific ELISA kit. The concentrations were compared between dogs with MMVD and healthy dogs, and they were analyzed according to the severity of MMVD and PH. The median serum Ang-1 concentration did not differ among the study groups. The median serum Ang-2 concentration was higher in dogs with stage B2 MMVD (P = .041) and acute congestive heart failure (P = .002) than in control dogs. In addition, the median serum Ang-2 concentration was higher in MMVD dogs with PH than in those without PH (P = .031). Serum Ang-2 concentration was correlated with vertebral heart score (rs = 0.36, P = .004) and vertebral left atrial score (r = 0.50, P < .001) in dogs with MMVD, and correlated with vertebral heart score (r = 0.63, P = .01), maximum E wave amplitude of the diastolic transmitral flow (rs = 0.61, P = .018), ejection fraction (rs = -0.77, P < .001) and fractional shortening (rs = -0.56, P = .032) in dogs with acute congestive heart failure. Circulating Ang-2 levels increase in dogs with the severity of MMVD and the presence of PH.

Ang-1, Ang-2, and Tie2 are diagnostic biomarkers for Henoch-Schönlein purpura and pediatric-onset systemic lupus erythematous.

Henoch-Schönlein purpura (HSP) and pediatric-onset systemic lupus erythematosus (pSLE) are closely associated with vasculitis and vascular diseases. This study aimed to investigate the clinical diagnostic values of Ang-1, Ang-2, and Tie2 for HSP and pSLE. We surveyed 82 HSP patients, 34 pSLE patients, and 10 healthy children. The expression levels of Ang-1, Ang-2, and Tie2 in the serum and urine were assessed using enzyme-linked immunosorbent assay. The diagnostic values of Ang-1, Ang-2, and Tie2 for HSP and pSLE were evaluated using receiver operating characteristic curve analysis. The results revealed that the serum and urine expression levels of Ang-2 and Tie2 were significantly elevated in HSP and pSLE patients, whereas the Ang-1/Ang-2 values were reduced. Additionally, Ang-1 was highly expressed in the serum and urine of HSP patients and in the serum of pSLE patients. Ang-1, Ang-2, and Tie2 showed differential expression in various types of HSP and pSLE compared with their expression in healthy controls. In summary, Ang-1, Ang-2, and Tie2 can serve as biomarkers for HSP and pSLE. Moreover, Ang-1/Ang-2 values are reduced in HSP and pSLE patients. Ang-1, Ang-2, and Tie2 can be used as biomarkers for HSP and pSLE.