Levels of Angiopoietin 2 Are Predictive for Mortality in Patients Infected With Yellow Fever Virus.

In 2018 there was a large yellow fever outbreak in São Paulo, Brazil, with a high fatality rate. Yellow fever virus can cause, among other symptoms, hemorrhage and disseminated intravascular coagulation, indicating a role for endothelial cells in disease pathogenesis. Here, we conducted a case-control study and measured markers related to endothelial damage in plasma and its association with mortality. We found that angiopoietin 2 is strongly associated with a fatal outcome and could serve as a predictive marker for mortality. This could be used to monitor severe cases and provide care to improve disease outcome.

Beyond VEGF: Angiopoietin-Tie Signaling Pathway in Diabetic Retinopathy.

Complications from diabetic retinopathy such as diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) constitute leading causes of preventable vision loss in working-age patients. Since vascular endothelial growth factor (VEGF) plays a major role in the pathogenesis of these complications, VEGF inhibitors have been the cornerstone of their treatment. Anti-VEGF monotherapy is an effective but burdensome treatment for DME. However, due to the intensive and burdensome treatment, most patients in routine clinical practice are undertreated, and therefore, their outcomes are compromised. Even in adequately treated patients, persistent DME is reported anywhere from 30% to 60% depending on the drug used. PDR is currently treated by anti-VEGF, panretinal photocoagulation (PRP) or a combination of both. Similarly, a number of eyes, despite these treatments, continue to progress to tractional retinal detachment and vitreous hemorrhage. Clearly there are other molecular pathways other than VEGF involved in the pathogenesis of DME and PDR. One of these pathways is the angiopoietin-Tie signaling pathway. Angiopoietin 1 (Ang1) plays a major role in maintaining vascular quiescence and stability. It acts as a molecular brake against vascular destabilization and inflammation that is usually promoted by angiopoietin 2 (Ang2). Several pathological conditions including chronic hyperglycemia lead to Ang2 upregulation. Recent regulatory approval of the bi-specific antibody, faricimab, may improve long term outcomes in DME. It targets both the Ang/Tie and VEGF pathways. The YOSEMITE and RHINE were multicenter, double-masked, randomized non-inferiority phase 3 clinical trials that compared faricimab to aflibercept in eyes with center-involved DME. At 12 months of follow-up, faricimab demonstrated non-inferior vision gains, improved anatomic outcomes and a potential for extended dosing when compared to aflibercept. The 2-year results of the YOSEMITE and RHINE trials demonstrated that the anatomic and functional results obtained at the 1 year follow-up were maintained. Short term outcomes of previously treated and treatment-naive eyes with DME that were treated with faricimab during routine clinical practice suggest a beneficial effect of faricimab over other agents. Targeting of Ang2 has been reported by several other means including VE-PTP inhibitors, integrin binding peptide and surrobodies.

Angiopoietin2 is associated with coagulation activation and tissue factor expression in extracellular vesicles in COVID-19.

Coagulation activation in immunothrombosis involves various pathways distinct from classical hemostasis, offering potential therapeutic targets to control inflammation-induced hypercoagulability while potentially sparing hemostasis. The Angiopoietin/Tie2 pathway, previously linked to embryonic angiogenesis and sepsis-related endothelial barrier regulation, was recently associated with coagulation activation in sepsis and COVID-19. This study explores the connection between key mediators of the Angiopoietin/Tie2 pathway and coagulation activation. The study included COVID-19 patients with hypoxia and healthy controls. Blood samples were processed to obtain platelet-free plasma, and frozen until analysis. Extracellular vesicles (EVs) in plasma were characterized and quantified using flow cytometry, and their tissue factor (TF) procoagulant activity was measured using a kinetic chromogenic method. Several markers of hemostasis were assessed. Levels of ANGPT1, ANGPT2, and soluble Tie2 correlated with markers of coagulation and platelet activation. EVs from platelets and endothelial cells were increased in COVID-19 patients, and a significant increase in TF+ EVs derived from endothelial cells was observed. In addition, ANGPT2 levels were associated with TF expression and activity in EVs. In conclusion, we provide further evidence for the involvement of the Angiopoietin/Tie2 pathway in the coagulopathy of COVID-19 mediated in part by release of EVs as a potential source of TF activity.

Review of real-world evidence of dual inhibition of VEGF-A and ANG-2 with faricimab in NAMD and DME.

Management of vitreoretinal disorders (e.g., neovascular age-related macular degeneration [nAMD] and diabetic macular edema [DME]) have assumed the standard therapy of lifelong anti-VEGF injections with drugs like aflibercept, brolucizumab, ranibizumab and bevacizumab. However, the burden imposed on patients is a major deterrent for continual therapy and recovery. Faricimab, a bispecific antibody, blocking both VEGF-A and Ang-2 molecules, produces a comparable functional and anatomical results, with less injections, significantly reducing patient burden. Visual acuity, safety, adverse effects, and anatomical outcomes are discussed in the pivotal clinical trials (YOSEMITE/RHINE and TENAYA/LUCERNE), and early data from real-world studies (TRUCKEE, TAHOE, FARWIDE-DME, FARETINA and others). In YOSEMITE and RHINE, faricimab demonstrated non-inferior vision gains, better anatomical outcomes compared to aflibercept every 8 weeks. Faricimab in the personalized treatment interval (PTI), after week 96, achieved 12-week interval in 78.1% of the patients and 16-week interval in 62.3%. TENAYA and LUCERNE reported comparable best corrected visual acuity (BCVA) improvement and better anatomic outcomes during head-to-head phase, parallel to aflibercept, at its 8-week treatment schedule. Faricimab in the PTI regimen, after week 96 achieved 12-week interval in 77.8% of the patients and 16-week interval in 63.1%. Safety of faricimab has been comparable to aflibercept in these pivotal trials. Real-world data supports the data from the pivotal studies regarding the efficacy and safety profile of faricimab in heterogenous real world patient population. Moreover, in previously treated patients, it also demonstrated a faster fluid resolution, good safety profile. Considering faricimab has demonstrated anatomic and durability benefit in the treatment of nAMD and DME, additional data from ongoing extension clinical trials, AVONELLE-X and RHONE-X will help understand longer term outcomes for patients treated with faricimab as well as patients switching from aflibercept to faricimab after finishing the pivotal trials. Longer term data from the real-world studies will also continue to contribute to our understanding of long-term efficacy, safety and durability in the real world patient population.

Levels of angiopoietin-2 are predictive for mortality in yellow fever virus infected patients.

In 2018 there was a large yellow fever outbreak in São Paulo, Brazil, with a high fatality rate. Yellow fever virus can cause, among other symptoms, haemorrhage and disseminated intravascular coagulation, indicating a role for endothelial cells in the disease pathogenesis. Here, we conducted a case-control study and measured markers related to endothelial damage in plasma and its association with mortality. We found that angiopoietin-2 is strongly associated with a fatal outcome and could serve as a predictive marker for mortality. This could be used to monitor severe patients and provide care to improve disease outcome.

Association of Ang/Tie2 pathway mediators with endothelial barrier integrity and disease severity in COVID-19.

Endothelial barrier (EB) disruption contributes to acute lung injury in COVID-19, and levels of both VEGF-A and Ang-2, which are mediators of EB integrity, have been associated with COVID-19 severity. Here we explored the participation of additional mediators of barrier integrity in this process, as well as the potential of serum from COVID-19 patients to induce EB disruption in cell monolayers. In a cohort from a clinical trial consisting of thirty patients with COVID-19 that required hospital admission due to hypoxia we demonstrate that i) levels of soluble Tie2 were increase, and of soluble VE-cadherin were decreased when compared to healthy individuals; ii) sera from these patients induce barrier disruption in monolayers of endothelial cells; and iii) that the magnitude of this effect is proportional to disease severity and to circulating levels of VEGF-A and Ang-2. Our study confirms and extends previous findings on the pathogenesis of acute lung injury in COVID-19, reinforcing the concept that EB is a relevant component of this disease. Our results pave the way for future studies that can refine our understanding of the pathogenesis of acute lung injury in viral respiratory disorders, and contribute to the identification of new biomarkers and therapeutic targets for these conditions.

Reduced Angiopoietin Factor 2 Levels Are Correlated with Better Cardiac Function and Prognosis in Valvular Heart Disease

ABSTRACT Introduction: There are few circulating biomarkers for valvular heart disease. Angiopoietin (Ang) 1, Ang2, and vascular endothelial growth factor are important inflammation-associated cytokines. The aim of this study was to investigate the clinical significance and association of Ang1, Ang2, and vascular endothelial growth factor in valvular heart disease. Methods: This is a retrospective study; a total of 62 individuals (valvular heart disease patients [n=42] and healthy controls [n=20]) were included. Plasma levels of Ang1, Ang2, and vascular endothelial growth factor were detected by enzyme-linked immunosorbent assays. We retrospectively collected the baseline characteristics and short-term outcomes; logistic regression was performed to identify predictor for short-term mortality. Results: Ang2 was significantly decreased in the valvular heart disease group compared with the healthy control group (P=0.023), while no significant difference was observed in the Ang1 and vascular endothelial growth factor levels. The Ang2 level of New York Heart Association (NYHA) I/II patients — but not NYHA III/IV patients — was significantly decreased compared with that of healthy control individuals (NYHA I/II: P=0.017; NYHA III/IV: P=0.485). Univariable logistic regression analysis indicated that Ang2 was a significant independent predictor for short-term mortality (odds ratio 18.75, P=0.033, 95% confidence interval 8.08-102.33). Ang1 was negatively correlated with Ang2 (P=0.032, Pearson's correlation coefficient =-0.317) and was positively correlated with vascular endothelial growth factor (P=0.019, Pearson's correlation coefficient = 0.359). Conclusion: Ang2 might serve as a therapeutic and prognostic target for valvular heart disease.

Inhibition of ANGPT2 activates autophagy during hypertrophic scar formation via PI3K/AKT/mTOR pathway

Abstract Background Hypertrophic scar (HS), a fibroproliferative disorder caused by aberrant wound healing following skin injuries such as burns, lacerations and surgery, is characterized by invasive proliferation of fibroblasts and excessive extracellular matrix (ECM) accumulation. The dysregulation of autophagy is the pathological basis of HS formation. Previously, angiopoietin-2 (ANGPT2) was found to be overexpressed in HS fibroblasts (HSFs) compared with normal skin fibroblasts. However, whether ANGPT2 participates in the process of HS formation and the potential molecular mechanisms are not clear. Objective This study is intended to figure out the role of ANGPT2 and ANGPT2-mediated autophagy during the development of HS. Methods RT-qPCR was used to detect ANGPT2 expression in HS tissues and HSFs. HSFs were transfected with sh-ANGPT2 to knock down ANGPT2 expression and then treated with MHT1485, the mTOR agonist. The effects of sh-ANGPT2 or MHT1485 on the proliferation, migration, autophagy and ECM accumulation of HSFs were evaluated by CCK-8 assay, Transwell assay and western blotting. The expression of PI3K/Akt/mTOR pathway-related molecules (p-PI3K, p-Akt and p-mTOR) was assessed by western blotting. Results ANGPT2 expression was markedly upregulated in HS tissues and HSFs. ANGPT2 knockdown decreased the expression of p-PI3K, p-Akt and p-mTOR. ANGPT2 knockdown activated autophagy and inhibited the proliferation, migration, and ECM accumulation of HSFs. Additionally, the treatment of MHT1485, the mTOR agonist, on ANGPT2-downregulated HSFs, partially reversed the influence of ANGPT2 knockdown on HSFs. Study limitations The study lacks the establishment of more stable in vivo animal models of HS for investigating the effects of ANGPT2 on HS formation in experimental animals. Conclusions ANGPT2 downregulation represses growth, migration, and ECM accumulation of HSFs via autophagy activation by suppressing the PI3K/Akt/mTOR pathway. Our study provides a novel potential therapeutic target for HS.

Reduced Angiopoietin Factor 2 Levels Are Correlated with Better Cardiac Function and Prognosis in Valvular Heart Disease.

INTRODUCTION: There are few circulating biomarkers for valvular heart disease. Angiopoietin (Ang) 1, Ang2, and vascular endothelial growth factor are important inflammation-associated cytokines. The aim of this study was to investigate the clinical significance and association of Ang1, Ang2, and vascular endothelial growth factor in valvular heart disease. METHODS: This is a retrospective study; a total of 62 individuals (valvular heart disease patients [n=42] and healthy controls [n=20]) were included. Plasma levels of Ang1, Ang2, and vascular endothelial growth factor were detected by enzyme-linked immunosorbent assays. We retrospectively collected the baseline characteristics and short-term outcomes; logistic regression was performed to identify predictor for short-term mortality. RESULTS: Ang2 was significantly decreased in the valvular heart disease group compared with the healthy control group (P=0.023), while no significant difference was observed in the Ang1 and vascular endothelial growth factor levels. The Ang2 level of New York Heart Association (NYHA) I/II patients - but not NYHA III/IV patients - was significantly decreased compared with that of healthy control individuals (NYHA I/II: P=0.017; NYHA III/IV: P=0.485). Univariable logistic regression analysis indicated that Ang2 was a significant independent predictor for short-term mortality (odds ratio 18.75, P=0.033, 95% confidence interval 8.08-102.33). Ang1 was negatively correlated with Ang2 (P=0.032, Pearson's correlation coefficient =-0.317) and was positively correlated with vascular endothelial growth factor (P=0.019, Pearson's correlation coefficient = 0.359). CONCLUSION: Ang2 might serve as a therapeutic and prognostic target for valvular heart disease.

Inhibition of ANGPT2 activates autophagy during hypertrophic scar formation via PI3K/AKT/mTOR pathway.

BACKGROUND: Hypertrophic scar (HS), a fibroproliferative disorder caused by aberrant wound healing following skin injuries such as burns, lacerations and surgery, is characterized by invasive proliferation of fibroblasts and excessive extracellular matrix (ECM) accumulation. The dysregulation of autophagy is the pathological basis of HS formation. Previously, angiopoietin-2 (ANGPT2) was found to be overexpressed in HS fibroblasts (HSFs) compared with normal skin fibroblasts. However, whether ANGPT2 participates in the process of HS formation and the potential molecular mechanisms are not clear. OBJECTIVE: This study is intended to figure out the role of ANGPT2 and ANGPT2-mediated autophagy during the development of HS. METHODS: RT-qPCR was used to detect ANGPT2 expression in HS tissues and HSFs. HSFs were transfected with sh-ANGPT2 to knock down ANGPT2 expression and then treated with MHT1485, the mTOR agonist. The effects of sh-ANGPT2 or MHT1485 on the proliferation, migration, autophagy and ECM accumulation of HSFs were evaluated by CCK-8 assay, Transwell assay and western blotting. The expression of PI3K/Akt/mTOR pathway-related molecules (p-PI3K, p-Akt and p-mTOR) was assessed by western blotting. RESULTS: ANGPT2 expression was markedly upregulated in HS tissues and HSFs. ANGPT2 knockdown decreased the expression of p-PI3K, p-Akt and p-mTOR. ANGPT2 knockdown activated autophagy and inhibited the proliferation, migration, and ECM accumulation of HSFs. Additionally, the treatment of MHT1485, the mTOR agonist, on ANGPT2-downregulated HSFs, partially reversed the influence of ANGPT2 knockdown on HSFs. STUDY LIMITATIONS: The study lacks the establishment of more stable in vivo animal models of HS for investigating the effects of ANGPT2 on HS formation in experimental animals. CONCLUSIONS: ANGPT2 downregulation represses growth, migration, and ECM accumulation of HSFs via autophagy activation by suppressing the PI3K/Akt/mTOR pathway. Our study provides a novel potential therapeutic target for HS.

Sulfasalazine prevents lung injury due to intra-abdominal sepsis in rats: possible role of Nrf2 and angiopoietin-2

This study aimed to investigate the effect of sulfasalazine in preventing and treating intra-abdominal sepsis-induced acute respiratory distress syndrome (ARDS) in a rat model. Forty male Wistar albino rats were used. The rats were randomly divided into four equal groups, and sepsis was induced in 30 rats by intraperitoneal administration of a fecal saline solution prepared from rat feces. Group 1: normal control (n=10) [non-surgical], Group 2: fecal intraperitoneal injection (FIP) (n=10) [untreated septic group], Group 3: FIP+saline (placebo) (n=10) [saline administered intraperitoneally], Group 4 (n=10): FIP+sulfasalazine [250 mg/kg per day administered intraperitoneally]. Computed tomography was performed and blood samples were collected for biochemical and blood gas analysis. The lungs were removed for histopathological studies. Statistically significant reductions in interleukin (IL)-6, IL1-β, tumor necrosis factor (TNF)-α, malondialdehyde (MDA), and angiopoietin-2 (ANG-2) levels were observed in the sulfasalazine group compared to the FIP+saline group (P<0.001). Nrf2 levels were significantly higher in the sulfasalazine-treated group than in the FIP and FIP+saline groups (P<0.01). Lung tissue scores were significantly reduced in the sulfasalazine group compared to the other sepsis groups. The Hounsfield unit (HU) value was significantly lower in the sulfasalazine group than in the FIP+saline group (P<0.001). PaO2 values were significantly higher in the sulfasalazine-treated group than in the FIP+saline-treated group (P<0.05). Sulfasalazine was shown to be effective in preventing and treating ARDS.

Paricalcitol Improves the Angiopoietin/Tie-2 and VEGF/VEGFR2 Signaling Pathways in Adriamycin-Induced Nephropathy.

Renal endothelial cell (EC) injury and microvascular dysfunction contribute to chronic kidney disease (CKD). In recent years, increasing evidence has suggested that EC undergoes an endothelial-to-mesenchymal transition (EndoMT), which might promote fibrosis. Adriamycin (ADR) induces glomerular endothelial dysfunction, which leads to progressive proteinuria in rodents. The activation of the vitamin D receptor (VDR) plays a crucial role in endothelial function modulation, cell differentiation, and suppression of the expression of fibrotic markers by regulating the production of nitric oxide (NO) by activating the endothelial NO synthase (eNOS) in the kidneys. This study aimed to evaluate the effect of paricalcitol treatment on renal endothelial toxicity in a model of CKD induced by ADR in rats and explore mechanisms involved in EC maintenance by eNOS/NO, angiopoietins (Angs)/endothelium cell-specific receptor tyrosine kinase (Tie-2, also known as TEK) and vascular endothelial growth factor (VEGF)-VEGF receptor 2 (VEGFR2) axis. The results show that paricalcitol attenuated the renal damage ADR-induced with antiproteinuric effects, glomerular and tubular structure, and function protection. Furthermore, activation of the VDR promoted the maintenance of the function and structure of glomerular, cortical, and external medullary endothelial cells by regulating NO production. In addition, it suppressed the expression of the mesenchymal markers in renal tissue through attenuation of (transforming growth factor-beta) TGF-ß1/Smad2/3-dependent and downregulated of Ang-2/Tie-2 axis. It regulated the VEGF/VEGFR2 pathway, which was ADR-deregulated. These effects were associated with lower AT1 expression and VDR recovery to renal tissue after paricalcitol treatment. Our results showed a protective role of paricalcitol in the renal microvasculature that could be used as a target for treating the beginning of CKD.

Relationship Between Endothelial and Angiogenesis Biomarkers Envisage Mortality in a Prospective Cohort of COVID-19 Patients Requiring Respiratory Support.

Purpose: Endothelial damage and angiogenesis are fundamental elements of neovascularisation and fibrosis observed in patients with coronavirus disease 2019 (COVID-19). Here, we aimed to evaluate whether early endothelial and angiogenic biomarkers detection predicts mortality and major cardiovascular events in patients with COVID-19 requiring respiratory support. Methods: Changes in serum syndecan-1, thrombomodulin, and angiogenic factor concentrations were analysed during the first 24 h and 10 days after COVID-19 hospitalisation in patients with high-flow nasal oxygen or mechanical ventilation. Also, we performed an exploratory evaluation of the endothelial migration process induced by COVID-19 in the patients' serum using an endothelial cell culture model. Results: In 43 patients, mean syndecan-1 concentration was 40.96 ± 106.9 ng/mL with a 33.9% increase (49.96 ± 58.1 ng/mL) at day 10. Both increases were significant compared to healthy controls (Kruskal-Wallis p < 0.0001). We observed an increase in thrombomodulin, Angiopoietin-2, human vascular endothelial growth factor (VEGF), and human hepatocyte growth factor (HGF) concentrations during the first 24 h, with a decrease in human tissue inhibitor of metalloproteinases-2 (TIMP-2) that remained after 10 days. An increase in human Interleukin-8 (IL-8) on the 10th day accompanied by high HGF was also noted. The incidence of myocardial injury and pulmonary thromboembolism was 55.8 and 20%, respectively. The incidence of in-hospital deaths was 16.3%. Biomarkers showed differences in severity of COVID-19. Syndecan-1, human platelet-derived growth factor (PDGF), VEGF, and Ang-2 predicted mortality. A multiple logistic regression model with TIMP-2 and PDGF had positive and negative predictive powers of 80.9 and 70%, respectively, for mortality. None of the biomarkers predicted myocardial injury or pulmonary thromboembolism. A proteome profiler array found changes in concentration in a large number of biomarkers of angiogenesis and chemoattractants. Finally, the serum samples from COVID-19 patients increased cell migration compared to that from healthy individuals. Conclusion: We observed that early endothelial and angiogenic biomarkers predicted mortality in patients with COVID-19. Chemoattractants from patients with COVID-19 increase the migration of endothelial cells. Trials are needed for confirmation, as this poses a therapeutic target for SARS-CoV-2.

Association between angiopoietin-2 and functional cardiac remodeling in hemodialysis patients with normal left ventricular ejection.

Cardiac remodeling is the initial process in heart failure development. The aim of this study is to evaluate the association between endothelium-related biomarkers and cardiac remodeling in hemodialysis (HD) patients and how the presence of high blood pressure and diabetes mellitus modulates these associations. This was a cross-sectional study with adult HD and normal left ventricular (LV) ejection fraction-LVEF-patients. The authors correlated several endothelium-related biomarkers with echocardiographic indices-LV mass index (LVMi), LVEF, global longitudinal strain, mitral E/e', and aortic root diameter. Seventy-one patients were included, with 37 women (52.1%) and mean age of 54.3 ± 16.8 years. Angiopoietin-2 (AGPT2) was inversely correlated with global longitudinal strain (r = -.374, p = .001) and directly with E/e' (r = .265, p = .025). After adjustment, only AGPT2 was significantly associated with global longitudinal strain. blood pressure and diabetes mellitus were independent moderators for the AGPT2 and global longitudinal strain association. The conditional association was significant only when the mean pre-HD blood pressure was above 97.5 mmHg or in diabetes mellitus patients. Finally, there was an interaction between diabetes mellitus and blood pressure when moderating the conditional effect of AGPT2 on global longitudinal strain. While in non-diabetic patients, the association between AGPT2 with global longitudinal strain was significant only with pre-HD blood pressure levels as high as 110 mmHg, in diabetic patients, this association was significant with pre-HD blood pressure as low as 90 mmHg. Higher levels of AGPT2 were associated with worse cardiac function as determined by lower global longitudinal strain values. This association was moderated by blood pressure and diabetes mellitus, suggesting that the effects of AGPT2 on cardiac remodeling is dependent of such circumstances.

siRNA knockdown of angiopoietin 2 significantly reduces neovascularization in diabetic rats.

Diabetes is a disease that leads to proliferative diabetic retinopathy (PDR), which is associated with an increase of new vessels formation due to an overexpression of angiogenic factors, such as angiopoietin 2 (ANGPT2). The aim of this work was to design a siRNA targeting ANGPT2 to decrease the retinal neovascularization associated with PDR. Adult male Wistar rats weighing 325-375 g were used. Diabetes was induced by a single dose of streptozotocin (STZ, 60 mg/kg i.p.). The siRNAs were designed, synthesised, and administered intravitreally at the beginning of diabetes induction (t0), and after 4 weeks of diabetes evolution (t4), subsequently evaluated the retinal neovascularization (junctions and lacunarity) and ANGPT2 expression in the retina by RT-PCR, after 4 weeks of the siRNAs administration. The results showed that the administration of STZ produced significant increases in blood glucose levels, retinal neovascularization (augmented junctions and lower lacunarity), and ANGPT2 expression, while the administration of the ANGPT2-siRNAs at different groups (t0 and t4) reduces the junctions and increases the lacunarity in diabetic rats. Therefore, we conclude that the administration of siRNAs targeting ANGPT2 could be an option to decrease the retinal neovascularization associated with PDR and halt the progression of blindness caused by diabetes.

Lean adolescents with insulin resistance display higher angiopoietin like protein 3, ApoC-III and chylomicron remnant dyslipidemia.

BACKGROUND: Triglyceride-rich lipoproteins (TRL: chylomicrons and VLDL) are a key component of diabetes dyslipoproteinemia and cardiovascular risk. We have shown that it is already prevalent in obese adolescents in association with lipoprotein lipase (LPL) dysregulation. Insulin resistance (IR) suffices to produce TRL dyslipoproteinemia and LPL dysfunction even in the absence of obesity. METHODS: This cross-sectional study included euglycemic adolescents between 15 and 19 y, classified in 4 groups according to BMI, HOMA-IR and fasting lipid as: metabolically healthy lean (MHL, n = 30), metabolically unhealthy lean (MUL, n = 25), metabolically healthy obese (MHO, = 30), and metabolically unhealthy obese (MUO, n = 42). RESULTS: As compared to MHL, MUL participants showed 73% higher concentrations of ApoB-48; 84% of ApoC-III; 24% ANGPTL-3; 200% of TG; 218% of VLDL-C and 238% of TG/HDL-C c, No changes were found in LPL mass. Interestingly, the differences in these parameters between MUL and MHO were not significant. CONCLUSION: Euglycemic lean adolescents with IR display TRL dyslipoproteinemia with increased inhibition of LPL as highlighted by higher concentrations of ANGPTL-3, ApoC-III and fasting chylomicron remnants (ApoB-48).

Triglyceride-Rich Lipoproteins: Their Role in Atherosclerosis.

The term "triglyceride-rich lipoproteins" (TRLs) includes chylomicrons and their remnants, very low-density lipoproteins (VLDL), and intermediate-density lipoproteins (IDL). In this manuscript, the mechanisms by which atherogenic TRLs contribute to the formation of atheroma plaques are reviewed. Cholesterol from TRLs that can be retained in the subendothelial space (i.e., remnants, DLs, and small VLDLs) contributes to the genesis of atherosclerosis. Triglycerides of atherogenic TRLs induce inflammation of the arterial wall. Mechanisms that explain the involvement of TRLs in atherosclerosis are the generation of pro-atherogenic changes in high-density lipoproteins and low-density lipoproteins, accumulation of TRLs in plasma, and their passage to the subendothelial space where they cause endothelial dysfunction and inflammation of the vascular wall. Furthermore, plasma accumulation of TRLs causes hyperviscosity and a procoagulant state. Finally, this manuscript summarizes the controversial aspects of the clinical approach and the treatment of cases with dyslipidemia explained by atherogenic TRLs.

Angiopoietin-2 and angiopoietin-like 4 protein provide prognostic information in patients with suspected acute coronary syndrome.

BACKGROUND: Plasma levels of angiopoietin-2 (ANGPT2) and angiopoietin-like 4 protein (ANGPTL4) reflect different pathophysiological aspects of cardiovascular disease. We evaluated their association with outcome in a hospitalized Norwegian patient cohort (n = 871) with suspected acute coronary syndrome (ACS) and validated our results in a similar Argentinean cohort (n = 982). METHODS: A cox regression model, adjusting for traditional cardiovascular risk factors, was fitted for ANGPT2 and ANGPTL4, respectively, with all-cause mortality and cardiac death within 24 months and all-cause mortality within 60 months as the dependent variables. RESULTS: At 24 months follow-up, 138 (15.8%) of the Norwegian and 119 (12.1%) of the Argentinian cohort had died, of which 86 and 66 deaths, respectively, were classified as cardiac. At 60 months, a total of 259 (29.7%) and 173 (17.6%) patients, respectively, had died. ANGPT2 was independently associated with all-cause mortality in both cohorts at 24 months [hazard ratio (HR) 1.27 (95% confidence interval (CI), 1.08-1.50) for Norway, and HR 1.57 (95% CI, 1.27-1.95) for Argentina], with similar results at 60 months [HR 1.19 (95% CI, 1.05-1.35) (Norway), and HR 1.56 (95% CI, 1.30-1.88) (Argentina)], and was also significantly associated with cardiac death [HR 1.51 (95% CI, 1.14-2.00)], in the Argentinean population. ANGPTL4 was significantly associated with all-cause mortality in the Argentinean cohort at 24 months [HR 1.39 (95% CI, 1.15-1.68)] and at 60 months [HR 1.43 (95% CI, 1.23-1.67)], enforcing trends in the Norwegian population. CONCLUSIONS: ANGPT2 and ANGPTL4 were significantly associated with outcome in similar ACS patient cohorts recruited on two continents. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00521976. ClinicalTrials.gov Identifier: NCT01377402.

Synaptotagmin-Like Protein 2a Regulates Angiogenic Lumen Formation via Weibel-Palade Body Apical Secretion of Angiopoietin-2.

[Figure: see text].

Expression of Serum Vascular Endothelial Growth Factor and Angiopoietin Receptor Tie-2 in Essential Hypertension

ABSTRACT Objective: To investigate the serum levels of a vascular endothelial growth factor (VEGF), an angiogenic factor and a soluble angiopoietin receptor Tie-2 (sTie-2) in patients with essential hypertension. Methods: In the present study 90 individuals (56 males and 34 females, mean age 48 ± 7 years) have been divided into 3 groups: 30 patients with hypertension, 30 healthy individuals with a family history of hypertension and 30 healthy individuals with no family history of hypertension. All individuals have been evaluated in terms of blood pressure and biochemical parameters. The levels of VEGF and Tie-2 receptor have been evaluated by using the enzyme-linked immunosorbent assay method. Results: The findings suggested that the serum VEGF, sTie-2 receptor, low-density lipoprotein and triglycerides levels in the hypertensive patients were significantly higher than those in the control group (p < 0.05). However, the level of high-density lipoprotein cholesterol in the patients was significantly lower than in those in the control group (p < 0.05). In correlation analysis, a positive correlation was found statistically significant between the values of VEGF and sTie-2 (r = 0.405, p = 0.026). Conclusion: As a result of this study, our data indicate that serum levels of VEGF and Tie-2 receptor may be related to the primary hypertension. This study could inspire to further studies to explore the roles of VEGF and Tie-2 receptor in essential hypertension.