Protective effects of angiopoietin-like 4 on cerebrovascular and functional damages in ischaemic stroke

AIMS: Given the impact of vascular injuries and oedema on brain damage caused during stroke, vascular protection represents a major medical need. We hypothesized that angiopoietin-like 4 (ANGPTL4), a regulator of endothelial barrier integrity, might exert a protective effect during ischaemic stroke. METHODS AND RESULTS: Using a murine transient ischaemic stroke model, treatment with recombinant ANGPTL4 led to significantly decreased infarct size and improved behaviour. Quantitative characteristics of the vascular network (density and branchpoints) were preserved in ANGPTL4-treated mice. Integrity of tight and adherens junctions was also quantified and ANGPTL4-treated mice displayed increased VE-cadherin and claudin-5-positive areas. Brain oedema was thus significantly decreased in ANGPTL4-treated mice. In accordance, vascular damage and infarct severity were increased in angptl4-deficient mice thus providing genetic evidence that ANGPTL4 preserves brain tissue from ischaemia-induced alterations. Altogether, these data show that ANGPTL4 protects not only the global vascular network, but also interendothelial junctions and controls both deleterious inflammatory response and oedema. Mechanistically, ANGPTL4 counteracted VEGF signalling and thereby diminished Src-signalling downstream from VEGFR2. This led to decreased VEGFR2-VE-cadherin complex disruption, increased stability of junctions and thus increased endothelial cell barrier integrity of the cerebral microcirculation. In addition, ANGPTL4 prevented neuronal loss in the ischaemic area. CONCLUSION: These results, therefore, show ANGPTL4 counteracts the loss of vascular integrity in ischaemic stroke, by restricting Src kinase signalling downstream from VEGFR2. ANGPTL4 treatment thus reduces oedema, infarct size, neuronal loss, and improves mice behaviour. These results suggest that ANGPTL4 constitutes a relevant target for vasculoprotection and cerebral protection during stroke

Dynamic stroma reorganization drives blood vessel dysmorphia during glioma growth

Glioma growth and progression are characterized by abundant development of blood vessels that are highly aberrant and poorly functional, with detrimental consequences for drug delivery efficacy. The mechanisms driving this vessel dysmorphia during tumor progression are poorly understood. Using longitudinal intravital imaging in a mouse glioma model, we identify that dynamic sprouting and functional morphogenesis of a highly branched vessel network characterize the initial tumor growth, dramatically changing to vessel expansion, leakage, and loss of branching complexity in the later stages. This vascular phenotype transition was accompanied by recruitment of predominantly pro-inflammatory M1-like macrophages in the early stages, followed by in situ repolarization to M2-like macrophages, which produced VEGF-A and relocate to perivascular areas. A similar enrichment and perivascular accumulation of M2 versus M1 macrophages correlated with vessel dilation and malignancy in human glioma samples of different WHO malignancy grade. Targeting macrophages using anti-CSF1 treatment restored normal blood vessel patterning and function. Combination treatment with chemotherapy showed survival benefit, suggesting that targeting macrophages as the key driver of blood vessel dysmorphia in glioma progression presents opportunities to improve efficacy of chemotherapeutic agents. We propose that vessel dysfunction is not simply a general feature of tumor vessel formation, but rather an emergent property resulting from a dynamic and functional reorganization of the tumor stroma and its angiogenic influences

Vascular and liver homeostasis in juvenile mice require endothelial cyclic AMP-dependent protein kinase A

During vascular development, endothelial cAMP-dependent protein kinase A (PKA) regulates angiogenesis by controlling the number of tip cells, and PKA inhibition leads to excessive angiogenesis. Whether this role of endothelial PKA is restricted to embryonic and neonatal development or is also required for vascular homeostasis later on is unknown. Here, we show that perinatal (postnatal days P1-P3) of later (P28-P32) inhibition of endothelial PKA using dominant-negative PKA expressed under the control of endothelial-specific Cdh5-CreERT2 recombinase (dnPKA(iEC) mice) leads to severe subcutaneous edema, hypoalbuminemia, hypoglycemia and premature death. These changes were accompanied by the local hypersprouting of blood vessels in fat pads and the secondary enlargement of subcutaneous lymphatic vessels. Most noticeably, endothelial PKA inhibition caused a dramatic disorganization of the liver vasculature. Hepatic changes correlated with decreased gluconeogenesis, while liver albumin production seems to be unaffected and hypoalbuminemia is rather a result of increased leakage into the interstitium. Interestingly, the expression of dnPKA only in lymphatics using Prox1-CreERT2 produced no phenotype. Likewise, the mosaic expression in only endothelial subpopulations using Vegfr3-CreERT2 was insufficient to induce edema or hypoglycemia. Increased expression of the tip cell marker ESM1 indicated that the inhibition of PKA induced an angiogenic response in the liver, although tissue derived pro- and anti-angiogenic factors were unchanged. These data indicate that endothelial PKA is a gatekeeper of endothelial cell activation not only in development but also in adult homeostasis, preventing the aberrant reactivation of the angiogenic program

Heart failure in COVID-19: the multicentre, multinational PCHF-COVICAV registry.

AIMS: We assessed the outcome of hospitalized coronavirus disease 2019 (COVID-19) patients with heart failure (HF) compared with patients with other cardiovascular disease and/or risk factors (arterial hypertension, diabetes, or dyslipidaemia). We further wanted to determine the incidence of HF events and its consequences in these patient populations. METHODS AND RESULTS: International retrospective Postgraduate Course in Heart Failure registry for patients hospitalized with COVID-19 and CArdioVascular disease and/or risk factors (arterial hypertension, diabetes, or dyslipidaemia) was performed in 28 centres from 15 countries (PCHF-COVICAV). The primary endpoint was in-hospital mortality. Of 1974 patients hospitalized with COVID-19, 1282 had cardiovascular disease and/or risk factors (median age: 72 [interquartile range: 62-81] years, 58% male), with HF being present in 256 [20%] patients. Overall in-hospital mortality was 25% (n = 323/1282 deaths). In-hospital mortality was higher in patients with a history of HF (36%, n = 92) compared with non-HF patients (23%, n = 231, odds ratio [OR] 1.93 [95% confidence interval: 1.44-2.59], P < 0.001). After adjusting, HF remained associated with in-hospital mortality (OR 1.45 [95% confidence interval: 1.01-2.06], P = 0.041). Importantly, 186 of 1282 [15%] patients had an acute HF event during hospitalization (76 [40%] with de novo HF), which was associated with higher in-hospital mortality (89 [48%] vs. 220 [23%]) than in patients without HF event (OR 3.10 [2.24-4.29], P < 0.001). CONCLUSIONS: Hospitalized COVID-19 patients with HF are at increased risk for in-hospital death. In-hospital worsening of HF or acute HF de novo are common and associated with a further increase in in-hospital mortality

ANGPTL4, a multifaceted protein at the cross-talk between metabolism and cardiovascular disorders

We read with interest the letter from Fei Luo et al. Indeed, whether developing therapeutic agents aimed at long-term blocking ANGPTL4 is a matter of intense debate

Cardiovascular research in France Evolution of scientific activities and production over the last decade [La recherche cardiovasculaire en France évolution des activités et de la production scientifique au cours de la dernière décennie]

International audienceBackground: Cardiovascular disease (CVD) is a major cause of death worldwide, and fruitful research is needed for future advances in this field.Aims: To analyse the scientific production and vitality of French cardiovascular clinical research, and its evolution over the last decade.Methods: We first used Lab Times online data obtained through the Web of Science (Thomson-Reuters, Toronto, ON, Canada), then the PubMed database (National Center for Biotechnology Information [NCBI], Bethesda, MD, USA), for studies published between 2005 and 2015 in the multidisciplinary and cardiology journals with the highest impact factors. French abstracts submitted and accepted at the European Society of Cardiology (ESC) congress were provided directly by the ESC. The number of cardiovascular projects was analysed through the http://www.ClinicalTrials.gov database and the French site for government-funded projects, over the decade from 2008 to 2017.Results: Overall, France was ranked fifth in Europe and eighth worldwide for CVD publications. During the 10-year period from 2005 to 2015, French publications accounted for 0.2-0.3% of articles in top multidisciplinary journals and 2% of articles in top cardiology journals. We observed a steady decrease in French abstract submissions at the ESC congress (from 5% to 3.5% in 10 years), and in 2017, France was ranked eighth in Europe. Across European countries, France has been ranked first for declared cardiovascular research on http://www.ClinicalTrials.gov over the last 3 years, for both interventional and observational studies. Regarding the Hospital Programme of Clinical Research, heart ranked second after neurosciences.Conclusions: France is very well represented in terms of new CVD projects, but actual French scientific production scores poorly. Investing in CVD research is a priority to increase the level of publication and to compete with other leading countries