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

Analysis of circulating hem-endothelial marker RNA levels in preterm infants

<p>Abstract</p> <p>Background</p> <p>Circulating endothelial cells may serve as novel markers of angiogenesis. These include a subset of hem-endothelial progenitor cells that play a vital role in vascular growth and repair. The presence and clinical implications of circulating RNA levels as an expression for hematopoietic and endothelial-specific markers have not been previously evaluated in preterm infants. This study aims to determine circulating RNA levels of hem-endothelial marker genes in peripheral blood of preterm infants and begin to correlate these findings with prenatal complications.</p> <p>Methods</p> <p>Peripheral blood samples from seventeen preterm neonates were analyzed at three consecutive post-delivery time points (day 3–5, 10–15 and 30). Using quantitative reverse transcription-polymerase chain reaction we studied the expression patterns of previously established hem-endothelial-specific progenitor-associated genes (<it>AC133, Tie-2, Flk-1 (VEGFR2) and Scl/Tal1</it>) in association with characteristics of prematurity and preterm morbidity.</p> <p>Results</p> <p>Circulating <it>Tie-2 </it>and <it>SCL/Tal1 </it>RNA levels displayed an inverse correlation to gestational age (GA). We observed significantly elevated <it>Tie-2 </it>levels in preterm infants born to mothers with amnionitis, and in infants with sustained brain echogenicity on brain sonography. Other markers showed similar expression patterns yet we could not demonstrate statistically significant correlations.</p> <p>Conclusion</p> <p>These preliminary findings suggest that circulating RNA levels especially <it>Tie2 </it>and <it>SCL </it>decline with maturation and might relate to some preterm complication. Further prospective follow up of larger cohorts are required to establish this association.</p

Basilar artery occlusion management: An international survey of middle versus high-income countries

Background and Purpose Two early basilar artery occlusion (BAO) randomized controlled trials (RCTs) did not establish the superiority of endovascular thrombectomy (EVT) over medical management. Yet many providers continued to recommend EVT. The goal of the present article is to compare physicians’ diagnostic and management strategies of BAO among middle-income and high-income countries (MICs and HICs, respectively). Methods We conducted an international survey from January to March 2022 regarding management strategies in acute BAO, to examine clinical and imaging parameters influencing clinician management of patients with BAO. We compared responses between physicians from HIC and MIC. Results Among the 1245 respondents from 73 countries, 799 (64.2%) were from HIC, with the remaining 393 (31.6%) from MIC. Most respondents perceived that EVT was superior to medical management for acute BAO, but more so in respondents from HIC (98.0% vs. 94.2%, p < 0.01). MIC respondents were more likely to believe further RCTs were warranted (91.6% vs. 74.0%, p < 0.01) and were more likely to find it acceptable to enroll any patient who met a trial’s criteria in the standard medical treatment arm (58.8% vs. 38.5%, p < 0.01).Conclusions Conclusions In an area where clinical equipoise was called into question despite the lack of RCT evidence, we found that respondents from MIC were more likely to express willingness to enroll patients with BAO in an RCT than their HIC counterparts

Global impact of COVID-19 on stroke care

Background: The COVID-19 pandemic led to profound changes in the organization of health care systems worldwide. Aims: We sought to measure the global impact of the COVID-19 pandemic on the volumes for mechanical thrombectomy, stroke, and intracranial hemorrhage hospitalizations over a three-month period at the height of the pandemic (1 March–31 May 2020) compared with two control three-month periods (immediately preceding and one year prior). Methods: Retrospective, observational, international study, across 6 continents, 40 countries, and 187 comprehensive stroke centers. The diagnoses were identified by their ICD-10 codes and/or classifications in stroke databases at participating centers. Results: The hospitalization volumes for any stroke, intracranial hemorrhage, and mechanical thrombectomy were 26,699, 4002, and 5191 in the three months immediately before versus 21,576, 3540, and 4533 during the first three pandemic months, representing declines of 19.2% (95%CI, −19.7 to −18.7), 11.5% (95%CI, −12.6 to −10.6), and 12.7% (95%CI, −13.6 to −11.8), respectively. The decreases were noted across centers with high, mid, and low COVID-19 hospitalization burden, and also across high, mid, and low volume stroke/mechanical thrombectomy centers. High-volume COVID-19 centers (−20.5%) had greater declines in mechanical thrombectomy volumes than mid- (−10.1%) and low-volume (−8.7%) centers (p &lt; 0.0001). There was a 1.5% stroke rate across 54,366 COVID-19 hospitalizations. SARS-CoV-2 infection was noted in 3.9% (784/20,250) of all stroke admissions. Conclusion: The COVID-19 pandemic was associated with a global decline in the volume of overall stroke hospitalizations, mechanical thrombectomy procedures, and intracranial hemorrhage admission volumes. Despite geographic variations, these volume reductions were observed regardless of COVID-19 hospitalization burden and pre-pandemic stroke/mechanical thrombectomy volumes