Knockdown of ANGPTL2 promotes left ventricular systolic dysfunction by upregulation of NOX4 in mice.

Background: Angiopoietin-like 2 (ANGPTL2) is a pro-inflammatory and pro-oxidant circulating protein that predicts and promotes chronic inflammatory diseases such as atherosclerosis in humans. Transgenic murine models demonstrated the deleterious role of ANGPTL2 in vascular diseases, while deletion of ANGPTL2 was protective. The nature of its role in cardiac tissues is, however, less clear. Indeed, in adult mice knocked down (KD) for ANGPTL2, we recently reported a mild left ventricular (LV) dysfunction originating from a congenital aortic valve stenosis, demonstrating that ANGPTL2 is essential to cardiac development and function. Hypothesis: Because we originally demonstrated that the KD of ANGPTL2 protected vascular endothelial function via an upregulation of arterial NOX4, promoting the beneficial production of dilatory H2O2, we tested the hypothesis that increased cardiac NOX4 could negatively affect cardiac redox and remodeling and contribute to LV dysfunction observed in adult Angptl2-KD mice. Methods and results: Cardiac expression and activity of NOX4 were higher in KD mice, promoting higher levels of cardiac H2O2 when compared to wild-type (WT) mice. Immunofluorescence showed that ANGPTL2 and NOX4 were co-expressed in cardiac cells from WT mice and both proteins co-immunoprecipitated in HEK293 cells, suggesting that ANGPTL2 and NOX4 physically interact. Pressure overload induced by transverse aortic constriction surgery (TAC) promoted LV systolic dysfunction in WT mice but did not further exacerbate the dysfunction in KD mice. Importantly, the severity of LV systolic dysfunction in KD mice (TAC and control SHAM) correlated with cardiac Nox4 expression. Injection of an adeno-associated virus (AAV9) delivering shRNA targeting cardiac Nox4 expression fully reversed LV systolic dysfunction in KD-SHAM mice, demonstrating the causal role of NOX4 in cardiac dysfunction in KD mice. Targeting cardiac Nox4 expression in KD mice also induced an antioxidant response characterized by increased expression of NRF2/KEAP1 and catalase. Conclusion: Together, these data reveal that the absence of ANGPTL2 induces an upregulation of cardiac NOX4 that contributes to oxidative stress and LV dysfunction. By interacting and repressing cardiac NOX4, ANGPTL2 could play a new beneficial role in the maintenance of cardiac redox homeostasis and function.

Angiopoietin-Like Proteins: Cardiovascular Biology and Therapeutic Targeting for the Prevention of Cardiovascular Diseases.

Despite the best pharmacologic tools available, cardiovascular diseases (CVDs) remain a major cause of morbidity and mortality in developed countries. After 2 decades of research, new therapeutic targets, such as angiopoietin-like proteins (ANGPTLs), are emerging. ANGPTLs belong to a family of 8 members, from ANGPTL1 to ANGPTL8; they have structural homology with angiopoietins and are secreted in the circulation. ANGPTLs display a multitude of physiological and pathologic functions; they contribute to inflammation, angiogenesis, cell death, senescence, hematopoiesis, and play a role in repair, maintenance, and tissue homeostasis. ANGPTLs-particularly the triad ANGPTL3, 4, and 8-have an established role in lipid metabolism through the regulation of triacylglycerol trafficking according to the nutritional status. Some ANGPTLs also contribute to glucose metabolism. Therefore, dysregulation in ANGPTL expression associated with abnormal circulating levels are linked to a plethora of CVD and metabolic disorders including atherosclerosis, heart diseases, diabetes, but also obesity and cancers. Because ANGPTLs bind to different receptors according to the cell type, antagonists are therapeutically inadequate. Recently, direct inhibitors of ANGPTLs, mainly ANGPTL3, have been developed, and specific monoclonal antibodies and antisense oligonucleotides are currently being tested in clinical trials. The aim of the current review is to provide an up-to-date preclinical and clinical overview on the function of the 8 members of the ANGPTL family in the cardiovascular system, their contribution to CVD, and the therapeutic potential of manipulating some of them.

Angiopoietin-like 2 is essential to aortic valve development in mice.

Aortic valve (AoV) abnormalities during embryogenesis are a major risk for the development of aortic valve stenosis (AVS) and cardiac events later in life. Here, we identify an unexpected role for Angiopoietin-like 2 (ANGPTL2), a pro-inflammatory protein secreted by senescent cells, in valvulogenesis. At late embryonic stage, mice knocked-down for Angptl2 (Angptl2-KD) exhibit a premature thickening of AoV leaflets associated with a dysregulation of the fine balance between cell apoptosis, senescence and proliferation during AoV remodeling and a decrease in the crucial Notch signalling. These structural and molecular abnormalities lead toward spontaneous AVS with elevated trans-aortic gradient in adult mice of both sexes. Consistently, ANGPTL2 expression is detected in human fetal semilunar valves and associated with pathways involved in cell cycle and senescence. Altogether, these findings suggest that Angptl2 is essential for valvulogenesis, and identify Angptl2-KD mice as an animal model to study spontaneous AVS, a disease with unmet medical need.

Increased serum S100A12 levels are associated with higher risk of acute heart failure in patients with type 2 diabetes.

AIMS: The hyperglycaemic stress induces the release of inflammatory proteins such as S100A12, one of the endogenous ligands of the receptors for advanced glycation end products (RAGE). Chronic activation of RAGE has multiple deleterious effects in target tissues such as the heart and the vessels by promoting oxidative stress, inflammation by the release of cytokines, macrophages infiltration, and vascular cell migration and proliferation, causing ultimately endothelial cell and cardiomyocyte dysfunction. The aim of our study was to investigate the prognostic value of circulating S100A12 beyond established cardiovascular risk factors (CVRF) for heart failure (HF) and major adverse cardiovascular events (MACE) in a cohort of patients with type 2 diabetes. METHODS AND RESULTS: Serum S100A12 concentrations were measured at baseline in 1345 type 2 diabetes patients (58% men, 64 ± 11 years) recruited in the SURDIAGENE prospective cohort. Endpoints were the occurrence of acute HF requiring hospitalization (HHF) and MACE. We used a proportional hazard model adjusted for established CVRF (age, sex, duration of diabetes, estimated glomerular filtration rate, albumin/creatinine ratio, history of coronary artery disease) and serum S100A12. During the median follow-up of 84 months, 210 (16%) and 505 (38%) patients developed HHF and MACE, respectively. Baseline serum S100A12 concentrations were associated with an increased risk of HHF [hazard ratio (HR) (95% confidence interval) 1.28 (1.01-1.62)], but not MACE [1.04 (0.90-1.20)]. After adjustment for CVRF, S100A12 concentrations remained significantly associated with an increased risk of HHF [1.29 (1.01-1.65)]. In a sub-analysis, patients with high probability of pre-existing HF [N terminal pro brain natriuretic peptide (NT-proBNP) >1000 pg/mL, n = 87] were excluded. In the remaining 1258 patients, the association of serum S100A12 with the risk of HHF tended to be more pronounced [1.39 (1.06-1.83)]. When including the gold standard HF marker NT-proBNP in the model, the prognostic value of S100A12 for HHF did not reach significance. Youden method performed at 7 years for HHF prediction yielded an optimal cut-off for S100A12 concentration of 49 ng/mL (sensitivity 53.3, specificity 52.2). Compared with those with S100A12 ≤ 49 ng/mL, patients with S100A12 > 49 ng/mL had a significantly increased risk of HHF in the univariate model [HR = 1.58 (1.19-2.09), P = 0.0015] but also in the multivariate model [HR = 1.63 (1.23-2.16), P = 0.0008]. After addition of NT-proBNP to the multivariate model, S100A12 > 49 ng/mL remained associated with an increased risk of HHF [HR = 1.42 (1.07-1.90), P = 0.0160]. However, the addition of S100A12 categories on top of multivariate model enriched by NT-pro BNP did not improve the ability of the model to predict HHF (relative integrated discrimination improvement = 1.9%, P = 0.1500). CONCLUSIONS: In patients with type 2 diabetes, increased serum S100A12 concentration is independently associated with risk of HHF, but not with risk of MACE. Compared with NT-proBNP, the potential clinical interest of S100A12 for the prediction of HF events remains limited. However, S100A12 could be a candidate for a multimarker approach for HF risk assessment in diabetic patients.

Angptl2 is a Marker of Cellular Senescence: The Physiological and Pathophysiological Impact of Angptl2-Related Senescence.

Cellular senescence is a cell fate primarily induced by DNA damage, characterized by irreversible growth arrest in an attempt to stop the damage. Senescence is a cellular response to a stressor and is observed with aging, but also during wound healing and in embryogenic developmental processes. Senescent cells are metabolically active and secrete a multitude of molecules gathered in the senescence-associated secretory phenotype (SASP). The SASP includes inflammatory cytokines, chemokines, growth factors and metalloproteinases, with autocrine and paracrine activities. Among hundreds of molecules, angiopoietin-like 2 (angptl2) is an interesting, although understudied, SASP member identified in various types of senescent cells. Angptl2 is a circulatory protein, and plasma angptl2 levels increase with age and with various chronic inflammatory diseases such as cancer, atherosclerosis, diabetes, heart failure and a multitude of age-related diseases. In this review, we will examine in which context angptl2 was identified as a SASP factor, describe the experimental evidence showing that angptl2 is a marker of senescence in vitro and in vivo, and discuss the impact of angptl2-related senescence in both physiological and pathological conditions. Future work is needed to demonstrate whether the senescence marker angptl2 is a potential clinical biomarker of age-related diseases.

Therapeutic Potential of Quercetin to Alleviate Endothelial Dysfunction in Age-Related Cardiovascular Diseases.

The vascular endothelium occupies a catalog of functions that contribute to the homeostasis of the cardiovascular system. It is a physically active barrier between circulating blood and tissue, a regulator of the vascular tone, a biochemical processor and a modulator of coagulation, inflammation, and immunity. Given these essential roles, it comes to no surprise that endothelial dysfunction is prodromal to chronic age-related diseases of the heart and arteries, globally termed cardiovascular diseases (CVD). An example would be ischemic heart disease (IHD), which is the main cause of death from CVD. We have made phenomenal advances in treating CVD, but the aging endothelium, as it senesces, always seems to out-run the benefits of medical and surgical therapies. Remarkably, many epidemiological studies have detected a correlation between a flavonoid-rich diet and a lower incidence of mortality from CVD. Quercetin, a member of the flavonoid class, is a natural compound ubiquitously found in various food sources such as fruits, vegetables, seeds, nuts, and wine. It has been reported to have a wide range of health promoting effects and has gained significant attention over the years. A growing body of evidence suggests quercetin could lower the risk of IHD by mitigating endothelial dysfunction and its risk factors, such as hypertension, atherosclerosis, accumulation of senescent endothelial cells, and endothelial-mesenchymal transition (EndoMT). In this review, we will explore these pathophysiological cascades and their interrelation with endothelial dysfunction. We will then present the scientific evidence to quercetin's anti-atherosclerotic, anti-hypertensive, senolytic, and anti-EndoMT effects. Finally, we will discuss the prospect for its clinical use in alleviating myocardial ischemic injuries in IHD.

Pathological Continuum From the Rise in Pulse Pressure to Impaired Neurovascular Coupling and Cognitive Decline.

The "biomechanical hypothesis" stipulates that with aging, the cumulative mechanical damages to the cerebral microvasculature, magnified by risk factors for vascular diseases, contribute to a breach in cerebral homeostasis producing neuronal losses. In other words, vascular dysfunction affects brain structure and function, and leads to cognitive failure. This is gathered under the term Vascular Cognitive Impairment and Dementia (VCID). One of the main culprits in the occurrence of cognitive decline could be the inevitable rise in arterial pulse pressure due to the age-dependent stiffening of large conductance arteries like the carotids, which in turn, could accentuate the penetration of the pulse pressure wave deeper into the fragile microvasculature of the brain and damage it. In this review, we will discuss how and why the vascular and brain cells communicate and are interdependent, describe the deleterious impact of a vascular dysfunction on brain function in various neurodegenerative diseases and even of psychiatric disorders, and the potential chronic deleterious effects of the pulsatile blood pressure on the cerebral microcirculation. We will also briefly review data from antihypertensive clinical trial aiming at improving or delaying dementia. Finally, we will debate how the aging process, starting early in life, could determine our sensitivity to risk factors for vascular diseases, including cerebral diseases, and the trajectory to VCID.

Serum tenascin-C is independently associated with increased major adverse cardiovascular events and death in individuals with type 2 diabetes: a French prospective cohort.

AIMS/HYPOTHESIS: Tenascin-C (TN-C) is an extracellular matrix glycoprotein highly expressed in inflammatory and cardiovascular (CV) diseases. Serum TN-C has not yet been specifically studied in individuals with type 2 diabetes, a condition associated with chronic low-grade inflammation and increased CV disease risk. In this study, we hypothesised that elevated serum TN-C at enrolment in participants with type 2 diabetes would be associated with increased risk of death and major adverse CV events (MACE) during follow-up. METHODS: We used a prospective, monocentric cohort of consecutive type 2 diabetes participants (the SURDIAGENE [SUivi Rénal, DIAbète de type 2 et GENEtique] cohort) with all-cause death as a primary endpoint and MACE (CV death, non-fatal myocardial infarction or stroke) as a secondary endpoint. We used a proportional hazard model after adjustment for traditional risk factors and the relative integrated discrimination improvement (rIDI) to assess the incremental predictive value of TN-C for these risk factors. RESULTS: We monitored 1321 individuals (58% men, mean age 64 ± 11 years) for a median of 89 months. During follow-up, 442 individuals died and 497 had MACE. Multivariate Cox analysis showed that serum TN-C concentrations were associated with an increased risk of death (HR per 1 SD: 1.27 [95% CI 1.17, 1.38]; p < 0.0001) and MACE (HR per 1 SD: 1.23 [95% CI 1.13, 1.34]; p < 0.0001). Using TN-C concentrations on top of traditional risk factors, prediction of the risk of all-cause death (rIDI: 8.2%; p = 0.0006) and MACE (rIDI: 6.7%; p = 0.0014) improved significantly, but modestly. CONCLUSIONS/INTERPRETATION: In individuals with type 2 diabetes, increased serum TN-C concentrations were independently associated with death and MACE. Therefore, including TN-C as a prognostic biomarker could improve risk stratification in these individuals.

The impact of high-intensity interval training on ventricular remodeling in patients with a recent acute myocardial infarction-A randomized training intervention pilot study.

BACKGROUND: Aerobic exercise training is associated with beneficial ventricular remodeling and an improvement in cardiac biomarkers in chronic stable heart failure. High-intensity interval training (HIIT) is a time-efficient method to improve V ˙ O 2 peak in stable coronary heart disease patients. This pilot study aimed to compare the effect of HIIT on ventricular remodeling in patients with a recent acute myocardial infarction (AMI). METHODS: Nineteen post-AMI patients were randomized to either HIIT (n = 9) or usual care (n = 10). A cardiopulmonary exercise test (CPET), transthoracic echocardiography, and cardiac biomarker assessment (ie, N-terminal pro B-type natriuretic peptide levels and G protein-coupled receptor kinase 2 expression) were performed before and after a 12-week training intervention. CPET parameters including oxygen uptake efficiency slope (OUES) and V ˙ O 2 at the first ventilatory threshold ( V ˙ O 2 VT1) were calculated. left ventricular (LV) structural and functional echocardiographic parameters including myocardial strain imaging were assessed. RESULTS: V ˙ O 2 peak and OUES improved solely in the HIIT group (P < .05 for group/time, respectively). There was a significant training effect for the improvement of peak work load in both groups (P < .05). O2 pulse and V ˙ O 2 at VT1 both improved only in the HIIT group (P < .05 for time, no interaction). HIIT improved radial strain and pulsed-wave tissue Doppler imaging derived e' (P < .05 for time, no interaction). Cardiac biomarkers did not change in either group. CONCLUSIONS: In post-AMI patients, HIIT lead to significant improvements in prognostic CPET parameters compared to usual care. HIIT was associated with favorable ventricular remodeling regarding certain echocardiographic parameters of LV function.

Knockdown of angiopoietin-like 2 induces clearance of vascular endothelial senescent cells by apoptosis, promotes endothelial repair and slows atherogenesis in mice.

Elimination of senescent cells (SnC) is anti-atherogenic, but the specific contribution of senescent vascular endothelial cells (EC) is unknown. We inactivated angiopoietin like-2 (angptl2), a marker of SnEC and a pro-atherogenic cytokine in LDLr-/-, hApoB100+/+ atherosclerotic (ATX) mice. Three months after a single vascular delivery of a small hairpin (sh)Angptl2 in 3-month old ATX mice using an adeno-associated virus serotype 1 (AAV1), aortic atheroma plaque progression was slowed by 58% (p<0.0001). In the native aortic endothelium, angptl2 expression was decreased by 80%, in association with a reduced expression of p21, a cyclin-dependent kinase inhibitor overexpressed in growth-arrested SnC. Endothelial activation was reduced (lower Icam-1, Il-1ß and Mcp-1 expression), decreasing monocyte Cd68 expression in the endothelium. One week post-injection, the ratio Bax/Bcl2 increased in the endothelium only, suggesting that angptl2+/p21+ SnEC were eliminated by apoptosis. Four weeks post-injection, the endothelial progenitor marker Cd34 increased, suggesting endothelial repair. In arteries of atherosclerotic patients, we observed a strong correlation between p21 and ANGPTL2 (r=0.727, p=0.0002) confirming the clinical significance of angptl2-associated senescence. Our data suggest that therapeutic down-regulation of vascular angptl2 leads to the clearance of SnEC by apoptosis, stimulates endothelial repair and reduces atherosclerosis.

Systolic hypertension-induced neurovascular unit disruption magnifies vascular cognitive impairment in middle-age atherosclerotic LDLr-/-:hApoB+/+ mice.

Cognitive functions are dependent upon intercommunications between the cellular components of the neurovascular unit (NVU). Vascular risk factors are associated with a more rapid rate of cognitive decline with aging and cerebrovascular diseases magnify both the incidence and the rate of cognitive decline. The causal relationship between vascular risk factors and injury to the NVU is, however, lacking. We hypothesized that vascular risk factors, such as hypertension and dyslipidemia, promote disruption of the NVU leading to early cognitive impairment. We compared brain structure and cerebrovascular functions of 1-year old (middle-aged) male wild-type (WT) and atherosclerotic hypertensive (LDLr-/-:hApoB+/+, ATX) mice. In addition, mice were subjected, or not, to a transverse aortic constriction (TAC) for 6 weeks to assess the acute impact of an increase in systolic blood pressure on the NVU and cognitive functions. Compared with WT mice, ATX mice prematurely developed cognitive decline associated with cerebral micro-hemorrhages, loss of microvessel density and brain atrophy, cerebral endothelial cell senescence and dysfunction, brain inflammation, and oxidative stress associated with blood-brain barrier leakage and brain hypoperfusion. These data suggest functional disturbances in both vascular and parenchymal components of the NVU. Exposure to TAC-induced systolic hypertension promoted cerebrovascular damage and cognitive decline in WT mice, similar to those observed in sham-operated ATX mice; TAC exacerbated the existing cerebrovascular dysfunctions and cognitive failure in ATX mice. Thus, a hemodynamic stress such as systolic hypertension could initiate the cascade involving cerebrovascular injury and NVU deregulation and lead to cognitive decline, a process accelerated in atherosclerotic mice.

Non-Alcoholic Fatty Liver Disease, and the Underlying Altered Fatty Acid Metabolism, Reveals Brain Hypoperfusion and Contributes to the Cognitive Decline in APP/PS1 Mice.

Non-alcoholic fatty liver disease (NAFLD), the leading cause of chronic liver disease, is associated with cognitive decline in middle-aged adults, but the mechanisms underlying this association are not clear. We hypothesized that NAFLD would unveil the appearance of brain hypoperfusion in association with altered plasma and brain lipid metabolism. To test our hypothesis, amyloid precursor protein/presenilin-1 (APP/PS1) transgenic mice were fed a standard diet or a high-fat, cholesterol and cholate diet, inducing NAFLD without obesity and hyperglycemia. The diet-induced NAFLD disturbed monounsaturated and polyunsaturated fatty acid (MUFAs, PUFAs) metabolism in the plasma, liver, and brain, and particularly reduced n-3 PUFAs levels. These alterations in lipid homeostasis were associated in the brain with an increased expression of Tnfα, Cox2, p21, and Nox2, reminiscent of brain inflammation, senescence, and oxidative stress. In addition, compared to wild-type (WT) mice, while brain perfusion was similar in APP/PS1 mice fed with a chow diet, NAFLD in APP/PS1 mice reveals cerebral hypoperfusion and furthered cognitive decline. NAFLD reduced plasma ß40- and ß42-amyloid levels and altered hepatic but not brain expression of genes involved in ß-amyloid peptide production and clearance. Altogether, our results suggest that in a mouse model of Alzheimer disease (AD) diet-induced NAFLD contributes to the development and progression of brain abnormalities through unbalanced brain MUFAs and PUFAs metabolism and cerebral hypoperfusion, irrespective of brain amyloid pathology that may ultimately contribute to the pathogenesis of AD.

Reduction of plasma angiopoietin-like 2 after cardiac surgery is related to tissue inflammation and senescence status of patients.

OBJECTIVES: A strong relationship between high circulating angiopoietin-like 2 (ANGPTL2) levels, a proinflammatory adipokine, and cardiovascular diseases has been reported. Our objective was to determine whether plasma ANGPTL2 and high-sensitivity C-reactive protein (hs-CRP) levels change postoperatively in patients who underwent heart valve surgery and/or coronary artery bypass grafting. We hypothesized that a corrective cardiac surgery would decrease ANGPTL2 levels. METHODS: In 47 prospectively recruited patients who underwent coronary artery bypass grafting (n = 16), valve replacement (n = 16), or both (n = 15), we measured plasma ANGPTL2 and hs-CRP levels preoperatively, at 24 hours, at 3 to 5 days (hospital discharge), and at 30 to 90 days (follow-up) after surgery. Mediastinal adipose tissue and distal fragments of the left internal mammary artery (IMA) were harvested during surgery and mRNA expression of inflammatory and senescence markers was assessed using real-time quantitative polymerase chain reaction. RESULTS: ANGPTL2 and hs-CRP levels were elevated 24 hours after surgery and then returned to baseline levels. We noted, however, a dichotomy among patients: compared with baseline, plasma ANGPTL2 levels either significantly decreased (n = 21/47) or increased (n = 26/47) after surgery. In contrast, hs-CRP levels were identical between groups (P = .997). Patients in the increased group were older (P = .002) with a higher systolic blood pressure (P = .038) at baseline. Moreover, changes in ANGPTL2 levels (ΔANGPTL2 = final minus initial levels) positively correlated with mRNA expression of tumor necrosis factor α and interleukin 8 in mediastinal adipose tissue and IMA (P < .05) and with the senescence-associated marker cyclin-dependent kinase inhibitor 1 in IMA (P = .009). CONCLUSIONS: In younger patients with lower levels of tissue inflammation and arterial senescence load, ANGPTL2, but not hs-CRP levels decreased after cardiac surgery, suggesting that circulating ANGPTL2 reflects tissue inflammation and senescence.

High Systolic Blood Pressure Induces Cerebral Microvascular Endothelial Dysfunction, Neurovascular Unit Damage, and Cognitive Decline in Mice.

A chronic and gradual increase in pulse pressure (PP) is associated with cognitive decline and dementia in older individuals, but the mechanisms remain ill-defined. We hypothesized that a chronic elevation of PP would cause brain microvascular endothelial mechanical stress, damage the neurovascular unit, and ultimately induce cognitive impairment in mice, potentially contributing to the progression of vascular dementia and Alzheimer disease. To test our hypothesis, male control wild-type mice and Alzheimer disease model APP/PS1 (amyloid precursor protein/presenilin 1) mice were exposed to a transverse aortic constriction for 6 weeks, creating a PP overload in the right carotid (ipsilateral). We show that the transverse aortic constriction procedure associated with high PP induces a cascade of vascular damages in the ipsilateral parenchymal microcirculation: in wild-type mice, it impairs endothelial dilatory and blood brain barrier functions and causes microbleeds, a reduction in microvascular density, microvascular cell death by apoptosis, leading to severe hypoperfusion and parenchymal cell senescence. These damages were associated with brain inflammation and a significant reduction in learning and spatial memories. In APP/PS1 mice, that endogenously display severe cerebral vascular dysfunctions, microbleeds, parenchymal inflammation and cognitive dysfunction, transverse aortic constriction-induced high PP further aggravates cerebrovascular damage, Aß (beta-amyloid) accumulation, and prevents learning. Our study, therefore, demonstrates that brain microvessels are vulnerable to a high PP and mechanical stress associated with transverse aortic constriction, promoting severe vascular dysfunction, disruption of the neurovascular unit, and cognitive decline. Hence, chronic elevated amplitude of the PP could contribute to the development and progression of vascular dementia including Alzheimer disease.

Influence of micro- and macro-vascular disease and Tumor Necrosis Factor Receptor 1 on the level of lower-extremity amputation in patients with type 2 diabetes.

BACKGROUND: Patients with type 2 diabetes (T2D) face a high amputation rate. We investigated the relationship between the level of amputation and the presence of micro or macro-vascular disease and related circulating biomarkers, Tumor Necrosis Factor Receptor 1 (TNFR1) and Angiopoietin like-2 protein (ANGPTL2). METHODS: We have analyzed data from 1468 T2D participants in a single center prospective cohort (the SURDIAGENE cohort). Our outcome was the occurrence of lower limb amputation categorized in minor (below-ankle) or major (above ankle) amputation. Microvascular disease was defined as a history of albuminuria [microalbuminuria: uACR (urinary albumine-to-creatinine ratio) 30-299 mg/g or macroalbuminuria: uACR ≥ 300 mg/g] and/or severe diabetic retinopathy or macular edema. Macrovascular disease at baseline was divided into peripheral arterial disease (PAD): peripheral artery revascularization and/or major amputation and in non-peripheral macrovascular disease: coronary artery revascularization, myocardial infarction, carotid artery revascularization, stroke. We used a proportional hazard model considering survival without minor or major amputation. RESULTS: During a median follow-up period of 7 (0.5) years, 79 patients (5.5%) underwent amputation including 29 minor and 50 major amputations. History of PAD (HR 4.37 95% CI [2.11-9.07]; p < 0.001), severe diabetic retinopathy (2.69 [1.31-5.57]; p = 0.0073), male gender (10.12 [2.41-42.56]; p = 0.0016) and serum ANGPTL2 concentrations (1.25 [1.08-1.45]; p = 0.0025) were associated with minor amputation outcome. History of PAD (6.91 [3.75-12.72]; p < 0.0001), systolic blood pressure (1.02 [1.00-1.03]; p = 0.004), male gender (3.81 [1.67-8.71]; p = 0.002), and serum TNFR1 concentrations (HR 13.68 [5.57-33.59]; p < 0.0001) were associated with major amputation outcome. Urinary albumin excretion was not significantly associated with the risk of minor and major amputation. CONCLUSIONS: This study suggests that the risk factors associated with the minor vs. major amputation including biomarkers such as TNFR1 should be considered differently in patients with T2D.

Impact of pulse pressure on cerebrovascular events leading to age-related cognitive decline.

Aging is a modern concept: human life expectancy has more than doubled in less than 150 yr in Western countries. Longer life span, however, reveals age-related diseases, including cerebrovascular diseases. The vascular system is a prime target of aging: the "wear and tear" of large elastic arteries exposed to a lifelong pulsatile pressure causes arterial stiffening by fragmentation of elastin fibers and replacement by stiffer collagen. This arterial stiffening increases in return the amplitude of the pulse pressure (PP), its wave penetrating deeper into the microcirculation of low-resistance, high-flow organs such as the brain. Several studies have associated peripheral arterial stiffness responsible for the sustained increase in PP, with brain microvascular diseases such as cerebral small vessel disease, cortical gray matter thinning, white matter atrophy, and cognitive dysfunction in older individuals and prematurely in hypertensive and diabetic patients. The rarefaction of white matter is also associated with middle cerebral artery pulsatility that is strongly dependent on PP and artery stiffness. PP and brain damage are likely associated, but the sequence of mechanistic events has not been established. Elevated PP promotes endothelial dysfunction that may slowly develop in parallel with the accumulation of proinflammatory senescent cells and oxidative stress, generating cerebrovascular damage and remodeling, as well as brain structural changes. Here, we review data suggesting that age-related increased peripheral artery stiffness may promote the penetration of a high PP to cerebral microvessels, likely causing functional, structural, metabolic, and hemodynamic alterations that could ultimately promote neuronal dysfunction and cognitive decline.

Knockdown of angiopoietin-like 2 mimics the benefits of intermittent fasting on insulin responsiveness and weight loss.

Angiopoietin-like 2 (ANGPTL2) is an inflammatory adipokine linking obesity to insulin resistance. Intermittent fasting, on the other hand, is a lifestyle intervention able to prevent obesity and diabetes but difficult to implement and maintain. Our objectives were to characterize a link between ANGPTL2 and intermittent fasting and to investigate whether the knockdown of ANGPTL2 reproduces the benefits of intermittent fasting on weight gain and insulin responsiveness in knockdown and wild-type littermates mice. Intermittent fasting, access to food ad libitum once every other day, was initiated at the age of three months and maintained for four months. Intermittent fasting decreased by 63% (p < 0.05) gene expression of angptl2 in adipose tissue of wild-type mice. As expected, intermittent fasting improved insulin sensitivity (p < 0.05) and limited weight gain (p < 0.05) in wild-type mice. Knockdown mice fed ad libitum, however, were comparable to wild-type mice following the intermittent fasting regimen: insulin sensitivity and weight gain were identical, while intermittent fasting had no additional impact on these parameters in knockdown mice. Energy intake was similar between both wild-type fed intermittent fasting and ANGPTL2 knockdown mice fed ad libitum, suggesting that intermittent fasting and knockdown of ANGPTL2 equally lower feeding efficiency. These results suggest that the reduction of ANGPTL2 could be a useful and promising strategy to prevent obesity and insulin resistance, although further investigation of the mechanisms linking ANGPTL2 and intermittent fasting is warranted. Impact statement Intermittent fasting is an efficient diet pattern to prevent weight gain and improve insulin sensitivity. It is, however, a difficult regimen to follow and compliance is expected to be very low. In this work, we demonstrate that knockdown of ANGPTL2 in mice fed ad libitum mimics the beneficial effects of intermittent fasting on weight gain and insulin sensitivity in wild-type mice. ANGPTL2 is a cytokine positively associated with fat mass in humans, which inactivation in mice improves resistance to a high-fat metabolic challenge. This study provides a novel pathway by which IF acts to limit obesity despite equivalent energy intake. The development of a pharmacological ANGPTL2 antagonist could provide an efficient tool to reduce the burden of obesity.

High Circulating Levels of ANGPTL2: Beyond a Clinical Marker of Systemic Inflammation.

Angiopoietin-like 2 (ANGPTL2) is a proinflammatory protein belonging to the angiopoietin-like family. ANGPTL2 is secreted and detected in the systemic circulation. Different observational clinical studies reported that circulating levels of ANGPTL2 increase significantly in various chronic inflammatory diseases and showed associations between ANGPTL2 levels and diagnosis and/or prognosis of cardiovascular diseases, diabetes, chronic kidney disease, and various types of cancers. However, these studies did not address the following questions: (a) what are the sources of circulating ANGPTL2? (b) How and by which mechanisms an increase in circulating ANGPTL2 contributes to the pathogenesis of chronic inflammatory diseases? (c) Does an increase in circulating levels of ANGPTL2 measured in a well-defined chronic medical condition originate from a specific cell type? Mechanistic hypotheses have been proposed based on studies performed in mice and cultured cells, and proinflammatory, prooxidative, proangiogenic, proliferative, and antiapoptotic properties of ANGPTL2 have been reported. The aim of this review is to propose answers concerning the potential sources of circulating ANGPTL2 and its common pathological properties associated with various chronic inflammatory diseases and death in humans. We believe that high circulating ANGPTL2 levels are more than an inflammatory marker and may reflect the senescent cellular load of an individual.

Bariatric Surgery-Induced Lower Angiopoietin-Like 2 Protein Is Associated With Improved Cardiometabolic Profile.

BACKGROUND: Plasma angiopoietin-like 2 (Angptl2), a proinflammatory protein, has been associated with obesity and diabetes. Whether weight loss induced by bariatric surgery and associated improvement of the cardiometabolic risk profile influence circulating Angptl2 levels is unknown. We tested whether biliopancreatic diversion with duodenal switch (BPD-DS) surgery alters plasma Angptl2 concentrations. METHODS: Severely obese patients (n = 73; body mass index: 49.8 ± 7.1) underwent BPD-DS. Plasma levels of Angptl2 and metabolic biomarkers were obtained acutely (days 1 and 5) and at 6 and 12 months after surgery, and compared with results in an age- and sex-matched control group (n = 33) remaining on the waiting list. RESULTS: Preoperative Angptl2 levels were high (median: 12.3 ng/mL) and correlated with metabolic and anthropometric parameters. A significant (P < 0.01) increase in Angptl2 levels, fasting glucose, insulin, and interleukin-6 levels was observed acutely postoperatively (day 1) followed by a progressive decline from day 5. Besides weight loss, Angptl2 levels were decreased at the 12-month follow-up (11.5 ± 4.7 vs 14.0 ± 4.0 ng/mL, P < 0.0001), but not at the 6-month time point. Long-term changes in plasma Angptl2 levels showed significant positive correlations with changes in fasting glucose, insulin resistance, and tumour necrosis factor-α levels, and negative correlation with changes in leptin concentration (P < 0.05). No significant correlation was observed between changes in anthropometric parameters and Angptl2. CONCLUSIONS: Plasma Angptl2 levels decreased after BPD-DS in severely obese patients; no changes occurred in control participants. Lowered circulating levels of the inflammatory factor Angptl2 because of BPD-DS were closely related to favourable changes in glucose-insulin homeostasis and inflammatory profiles.