ObjectiveWe tested the hypothesis that the risk of intracranial hemorrhage (ICH) in patients with cardioembolic ischemic stroke who are treated with oral anticoagulants (OAs) can be predicted by evaluating surrogate markers of hemorrhagic-prone cerebral angiopathies using a baseline MRI.MethodsPatients were participants in a multicenter and prospective observational study. They were older than 64 years, had a recent cardioembolic ischemic stroke, and were new users of OAs. They underwent a baseline MRI analysis to evaluate microbleeds, white matter hyperintensities, and cortical superficial siderosis. We collected demographic variables, clinical characteristics, risk scores, and therapeutic data. The primary endpoint was ICH that occurred during follow-up. We performed bivariate and multivariate Cox regression analyses.ResultsWe recruited 937 patients (aged 77.6 ± 6.5 years; 47.9% were men). Microbleeds were detected in 207 patients (22.5%), moderate/severe white matter hyperintensities in 419 (45.1%), and superficial siderosis in 28 patients (3%). After a mean follow-up of 23.1 ± 6.8 months, 18 patients (1.9%) experienced an ICH. In multivariable analysis, microbleeds (hazard ratio 2.7, 95% confidence interval [CI] 1.1–7, p = 0.034) and moderate/severe white matter hyperintensities (hazard ratio 5.7, 95% CI 1.6–20, p = 0.006) were associated with ICH (C index 0.76, 95% CI 0.66–0.85). Rate of ICH was highest in patients with both microbleed and moderate/severe WMH (3.76 per 100 patient-years, 95% CI 1.62–7.4).ConclusionPatients taking OAs who have advanced cerebral small vessel disease, evidenced by microbleeds and moderate to severe white matter hyperintensities, had an increased risk of ICH. Our results should help to determine the risk of prescribing OA for a patient with cardioembolic stroke.ClinicalTrials.gov identifierNCT02238470.

Thrombotic material retrieved from acute ischemic stroke (AIS) patients represents a valuable source of biological information. In this study, we have developed a clinical proteomics workflow to characterize the protein cargo of thrombi derived from AIS patients. To analyze the thrombus proteome in a large-scale format, we developed a workflow that combines the isolation of thrombus by endovascular thrombectomy and peptide chromatographic fractionation coupled to mass-spectrometry. Using this workflow, we have characterized a specific proteomic expression profile derived from four AIS patients included in this study. Around 1600 protein species were unambiguously identified in the analyzed material. Functional bioinformatics analyses were performed, emphasizing a clustering of proteins with immunological functions as well as cardiopathy-related proteins with blood-cell dependent functions and peripheral vascular processes. In addition, we established a reference proteomic fingerprint of 341 proteins commonly detected in all patients. Protein interactome network of this subproteome revealed protein clusters involved in the interaction of fibronectin with 14-3-3 proteins, TGFβ signaling, and TCP complex network. Taken together, our data contributes to the repertoire of the human thrombus proteome, serving as a reference library to increase our knowledge about the molecular basis of thrombus derived from AIS patients, paving the way toward the establishment of a quantitative approach necessary to detect and characterize potential novel biomarkers in the stroke field.

Background: The discovery of novel biomarkers of stroke etiology would be most helpful in management of acute ischemic stroke patients. Recently, circular RNAs (circRNAs) have been proposed as candidate biomarkers of neurological conditions due to its high stability. circRNAs function as sponges, sequestering miRNAs and are involved in most relevant biological functions. Our aim was to identify differentially expressed circRNAs in acute ischemic stroke patients according to stroke etiology. Methods: A comprehensive expression profile of blood circRNAs was conducted by Arraystar Human circRNA arrays (13,617 probes) on a discovery cohort of 30 stroke patients with different stroke etiologies by TOAST classification. Real-time quantitative PCR (RT-qPCR) was used to validate array results in a cohort of 50 stroke patients. Functional in silico analysis was performed to identify potential interactions with microRNAs (miRNAs) and pathways underlying deregulated circRNAs. Results: A set of 60 circRNAs were found to be upregulated in atherotrombotic versus cardioembolic strokes (foldchange > = 1.5 and p-value ≤ 0.05). Differential expression of hsa_circRNA_102488, originated from UBA52 gene, was replicated in the validation cohort. RNA-binding proteins (RBPs) sites of hsa_circRNA_102488 clustered around AGO2 and FUS proteins. Further functional analysis revealed interactions between deregulated circRNAs and a set of miRNAs involved in stroke-related pathways, such as fatty acid biogenesis or lysine degradation. Conclusion: Different stroke subtypes show specific profiles of circRNAs expression. circRNAs may serve as a new source of biomarkers of stroke etiology in acute ischemic stroke patients.

Background Inflammatory response plays an important role in many processes related to acute ischemic stroke (AIS). Calprotectin (S100A8/S100A9), released by monocytes and neutrophils, is a key protein in the regulation of inflammation and thrombosis. The purpose of this study is to evaluate the association of circulating calprotectin with other inflammatory biomarkers and AIS prognosis, as well as the calprotectin content in stroke thrombi. Methods Among the 748 patients treated at a comprehensive stroke center between 2015 and 2017, 413 patients with confirmed acute ischemic injury were prospectively evaluated. Patients with systemic inflammation or infection at onset were excluded. Plasma calprotectin was measured by ELISA in blood samples of AIS patients within the first 24 h. Univariate and multivariate logistic regression models were performed to evaluate its association with mortality and functional independence (FI) at 3 months (defined as modified Rankin Scale < 3) and hemorrhagic transformation (HT) after ischemic stroke. Further, S100A9 was localized by immunostaining in stroke thrombi (n = 44). Results Higher calprotectin levels were associated with 3-month mortality, HT, and lower 3-month FI. After adjusting for potential confounders, plasma calprotectin remained associated with 3-month mortality [OR (95% CI) 2.31 (1.13–4.73)]. Patients with calprotectin ≥ 2.26 μg/mL were 4 times more likely to die [OR 4.34 (1.95–9.67)]. Addition of calprotectin to clinical variables led to significant improvement in the discrimination capacity of the model [0.91 (0.87–0.95) vs 0.89 (0.85–0.93); p < 0.05]. A multimarker approach demonstrated that patients with increased calprotectin, CRP, and NLR had the poorest outcome with a mortality rate of 42.3% during follow-up. S100A9 protein, as part of the heterodimer calprotectin, was present in all thrombi retrieved from AIS patients. Mean S100A9 content was 3.5% and tended to be higher in patients who died (p = 0.09). Moreover, it positively correlated with platelets (Pearson r 0.46, p < 0.002), leukocytes (0.45, p < 0.01), and neutrophil elastase (0.70, p < 0.001) thrombus content. Conclusions Plasma calprotectin is an independent predictor of 3-month mortality and provides complementary prognostic information to identify patients with poor outcome after AIS. The presence of S100A9 in stroke thrombi suggests a possible inflammatory mechanism in clot formation, and further studies are needed to determine its influence in resistance to reperfusion.

Diabetes is an important risk factor for ischemic stroke (IS). Tissue-type plasminogen activator (tPA) has been associated with less successful revascularization and poor functional outcome in diabetes. We assessed whether a new thrombolytic strategy based on MMP10 was more effective than tPA in a murine IS model of streptozotocin (STZ)-induced diabetes. Wild-type mice were administered a single dose of streptozotocin (STZ) (180 mg/kg) to develop STZ-induced diabetes mellitus. Two weeks later, IS was induced by thrombin injection into the middle cerebral artery and the effect of recombinant MMP10 (6.5 μg/kg), tPA (10 mg/kg) or tPA/MMP10 on brain damage and functional outcome were analysed. Motor activity was assessed using the open field test. Additionally, we studied plasminogen activator inhibitor-1 (PAI-1) and thrombin-antithrombin complex levels (TAT) by ELISA and oxidative stress and blood-brain barrier (BBB) integrity by immunohistochemistry and western blot. MMP10 treatment was more effective at reducing infarct size and neurodegeneration than tPA 24 h and 3 days after IS in diabetic mice. Locomotor activity was impaired by hyperglycemia and ischemic injury, but not by the thrombolytic treatments. Additionally, TAT, oxidative stress and BBB permeability were reduced by MMP10 treatment, whereas brain bleeding or PAI-1 expression did not differ between treatments. Thrombolytic treatment with MMP10 was more effective than tPA at reducing stroke and neurodegeneration in a diabetic murine model of IS, without increasing haemorrhage. Thus, we propose MMP10 as a potential candidate for the clinical treatment of IS in diabetic patients.