Differential blood-based biomarkers of subcortical and deep brain small vessel disease.

Background: Cerebral small vessel disease is the most common cause of lacunar strokes (LS). Understanding LS pathogenesis is vital for predicting disease severity, prognosis, and developing therapies. Objectives: To research molecular profiles that differentiate LS in deep brain structures from those in subcortical white matter. Design: Prospective case-control study involving 120 patients with imaging-confirmed LS and a 120 control group. Methods: We examined the relationship between Alzheimer's disease biomarkers [amyloid beta (Aß1-40, Aß1-42)], serum inflammatory marker (interleukin-6, IL-6), and endothelial dysfunction markers [soluble tumor necrosis factor-like weak inducer of apoptosis, and pentraxin-3 (sTWEAK, PTX3)] with respect to LS occurring in deep brain structures and subcortical white matter. In addition, we investigated links between LS, leukoaraiosis presence (white matter hyperintensities, WMHs), and functional outcomes at 3 months. Poor outcome was defined as a modified Rankin scale >2 at 3 months. Results: Significant differences were observed in levels of IL-6, PTX3, and sTWEAK between patients with deep lacunar infarcts and those with recent small subcortical infarcts (20.8 versus 15.6 pg/mL, p < 0.001; 7221.3 versus 4624.4 pg/mL, p < 0.0001; 2528.5 versus 1660.5 pg/mL, p = 0.001). Patients with poor outcomes at 3 months displayed notably higher concentrations of these biomarkers compared to those with good outcomes. By contrast, Aß1-40 and Aß1-42 were significantly lower in patients with deep LS (p < 0.0001). Aß1-42 levels were significantly higher in patients with LS in subcortical white matter who had poor outcomes. WMH severity only showed a significant association with deep LS and correlated with sTWEAK (p < 0.0001). Conclusion: The pathophysiological mechanisms of lacunar infarcts in deep brain structures seem different from those in the subcortical white matter. As a result, specific therapeutic and preventive strategies should be explored.

Plasma fibrinogen and risk of vascular recurrence after ischaemic stroke: An individual participant and summary-level data meta-analysis of 11 prospective studies.

INTRODUCTION: Inflammation is an emerging target for secondary prevention after stroke and randomised trials of anti-inflammatory therapies are ongoing. Fibrinogen, a putative pro-inflammatory marker, is associated with first stroke, but its association with major adverse cardiovascular events (MACE) after stroke is unclear. MATERIALS AND METHODS: We did a systematic review investigating the association between fibrinogen and post-stroke vascular recurrence. Authors were invited to provide individual-participant data (IPD) and where available we did within-study multivariable analyses with adjustment for cardiovascular risk factors and medications. Adjusted summary-level data was extracted from published reports from studies that did not provide IPD. We pooled risk ratios (RR) by random-effects meta-analysis by comparing supra-median with sub-median fibrinogen levels and performed pre-specified subgroup analysis according to timing of phlebotomy after the index event. RESULTS: Eleven studies were included (14,002 patients, 42,800 follow-up years), of which seven provided IPD. Fibrinogen was associated with recurrent MACE on unadjusted (RR 1.35, 95% CI 1.17-1.57, supra-median vs sub-median) and adjusted models (RR 1.21, 95% CI 1.06-1.38). Fibrinogen was associated with recurrent stroke on univariate analysis (RR 1.19, 95% CI 1.03-1.39), but not after adjustment (RR 1.11, 95% CI 0.94-1.31). The association with recurrent MACE was consistently observed in patients with post-acute (⩾14 days) fibrinogen measures (RR 1.29, 95% CI 1.16-1.45), but not in those with early phlebotomy (<14 days) (RR 0.98, 95% CI 0.82-1.18) (Pinteraction = 0.01). Similar associations were observed for recurrent stroke. DISCUSSION AND CONCLUSION: Fibrinogen was independently associated with recurrence after stroke, but the association was modified by timing of phlebotomy. Fibrinogen measurements might be useful to identify patients who are more likely to derive benefit from anti-inflammatory therapies after stroke.

Pharmacological preclinical comparison of tenecteplase and alteplase for the treatment of acute stroke.

Alteplase (rtPA) remains the standard thrombolytic drug for acute ischemic stroke. However, new rtPA-derived molecules, such as tenecteplase (TNK), with prolonged half-lives following a single bolus administration, have been developed. Although TNK is currently under clinical evaluation, the limited preclinical data highlight the need for additional studies to elucidate its benefits. The toxicities of rtPA and TNK were evaluated in endothelial cells, astrocytes, and neuronal cells. In addition, their in vivo efficacy was independently assessed at two research centers using an ischemic thromboembolic mouse model. Both therapies were tested via early (20 and 30 min) and late administration (4 and 4.5 h) after stroke. rtPA, but not TNK, caused cell death only in neuronal cultures. Mice were less sensitive to thrombolytic therapies than humans, requiring doses 10-fold higher than the established clinical dose. A single bolus dose of 2.5 mg/kg TNK led to an infarct reduction similar to perfusion with 10 mg/kg of rtPA. Early administration of TNK decreased the hemorrhagic transformations compared to that by the early administration of rtPA; however, this result was not obtained following late administration. These two independent preclinical studies support the use of TNK as a promising reperfusion alternative to rtPA.

Systemic biomarker associated with poor outcome after futile reperfusion.

BACKGROUND: Successful recanalization does not lead to complete tissue reperfusion in a considerable percentage of ischemic stroke patients. This study aimed to identify biomarkers associated with futile recanalization. Leukoaraiosis predicts poor outcomes of this phenomenon. Soluble tumour necrosis factor-like weak inducer of apoptosis (sTWEAK), which is associated with leukoaraiosis degrees, could be a potential biomarker. METHODS: This study includes two cohorts of ischemic stroke patients in a multicentre retrospective observational study. Effective reperfusion, defined as a reduction of ≥8 points in the National Institutes of Health Stroke Scale (NIHSS) within the first 24 h, was used as a clinical marker of effective reperfusion. RESULTS: In the first cohort study, female sex, age, and high NIHSS at admission (44.7% vs. 81.1%, 71.3 ± 13.7 vs. 81.1 ± 6.7; 16 [13, 21] vs. 23 [17, 28] respectively; p < .0001) were confirmed as predictors of futile recanalization. ROC curve analysis showed that leukocyte levels (sensitivity of 99%, specificity of 55%) and sTWEAK level (sensitivity of 92%, specificity of 88%) can discriminate between poor and good outcomes. Both biomarkers simultaneously are higher associated with outcome after effective reperfusion (OR: 2.17; CI 95% 1.63-4.19; p < .0001) than individually (leukocytes OR: 1.38; CI 95% 1.00-1.64, p = .042; sTWEAK OR: 1.00; C I95% 1.00-1.01, p = .019). These results were validated using a second cohort, where leukocytes and sTWEAK showed a sensitivity of 100% and specificity of 66.7% and 75% respectively. CONCLUSIONS: Leukocyte and sTWEAK could be biomarkers of reperfusion failure and subsequent poor outcomes. Further studies will be necessary to explore its role in reperfusion processes.

C-Reactive Protein, Interleukin-6, and Vascular Recurrence According to Stroke Subtype: An Individual Participant Data Meta-Analysis

BACKGROUND AND OBJECTIVES: Anti-inflammatory therapies reduce major adverse cardiovascular events (MACE) in coronary artery disease but remain unproven after stroke. Establishing the subtype-specific association between inflammatory markers and recurrence risk is essential for optimal selection of patients in randomized trials (RCTs) of anti-inflammatory therapies for secondary stroke prevention. METHODS: Using individual participant data (IPD) identified from a systematic review, we analyzed the association between high-sensitivity C-reactive protein, interleukin-6 (IL-6), and vascular recurrence after ischemic stroke or transient ischemic attack. The prespecified coprimary end points were (1) any recurrent MACE (first major coronary event, recurrent stroke, or vascular death) and (2) any recurrent stroke (ischemic, hemorrhagic, or unspecified) after sample measurement. Analyses were performed stratified by stroke mechanism, per quarter and per biomarker unit increase after loge transformation. We then did study-level meta-analysis with comparable published studies not providing IPD. Preferred Reporting Items for Systematic Review and Meta-Analyses IPD guidelines were followed. RESULTS: IPD was obtained from 10 studies (8,420 patients). After adjustment for vascular risk factors and statins/antithrombotic therapy, IL-6 was associated with recurrent MACE in stroke caused by large artery atherosclerosis (LAA) (risk ratio [RR] 2.30, 95% CI 1.21-4.36, p = 0.01), stroke of undetermined cause (UND) (RR 1.78, 1.19-2.66, p = 0.005), and small vessel occlusion (SVO) (RR 1.71, 0.99-2.96, p = 0.053) (quarter 4 [Q4] vs quarter 1 [Q1]). No association was observed for stroke due to cardioembolism or other determined cause. Similar results were seen for recurrent stroke and when analyzed per loge unit increase for MACE (LAA, RR 1.26 [1.06-1.50], p = 0.009; SVO, RR 1.22 [1.01-1.47], p = 0.04; UND, RR 1.18 [1.04-1.34], p = 0.01). High-sensitivity CRP was associated with recurrent MACE in UND stroke only (Q4 vs Q1 RR 1.45 [1.04-2.03], p = 0.03). Findings were consistent on study-level meta-analysis of the IPD results with 2 other comparable studies (20,136 patients). DISCUSSION: Our data provide new evidence for the selection of patients in future RCTs of anti-inflammatory therapy in stroke due to large artery atherosclerosis, small vessel occlusion, and undetermined etiology according to inflammatory marker profile.

Edoxaban treatment in a post-infarction experimental model.

BACKGROUND: The sequelae of myocardial infarction (MI) require specific pharmacological therapy to minimise the post-MI remodelling, which in many cases evolves into cardiovascular complications. The aim of this study was to analyse the effect of edoxaban, an oral anticoagulant, on cardiac recovery in a rat model of permanent coronary artery ligation. METHODS: An experimental method to assess the post-MI remodelling in rats for 4 weeks, based on cardiac magnetic resonance imaging (MRI) and final histological analysis of the hearts was performed. The influence of daily oral treatment with edoxaban (20 mg/kg/day) for 28 days post-MI was analysed in comparison to vehicle. RESULTS: In our model, edoxaban was shown to be safe and bleeding was observed in 1 of 10 animals. General physical recovery of the treated animals was shown by higher body weight recovery compared with non-treated animals (38.6 ± 2.9 vs. 29.9 ± 3.1 g, respectively, after 28 days). There was not a pronounced effect of edoxaban in post-MI cardiac remodelling, but mitigated fibrosis was observed by the reduced expression of vascular endothelial growth factor and tumour growth factor ß1 in the peri-infarct zone. CONCLUSIONS: Our analysis provided the experimental basis to support the feasibility of MRI to study cardiac function and characterise myocardial scarring in a rat model. Overall data suggested the safety of edoxaban in the model, and compared to placebo, it showed a better post-MI recovery, probably by reducing fibrosis of the heart. Further research on mid-term cardiac recovery with edoxaban after MI is justified.

Perfusion-weighted software written in Python for DSC-MRI analysis.

Introduction: Dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion studies in magnetic resonance imaging (MRI) provide valuable data for studying vascular cerebral pathophysiology in different rodent models of brain diseases (stroke, tumor grading, and neurodegenerative models). The extraction of these hemodynamic parameters via DSC-MRI is based on tracer kinetic modeling, which can be solved using deconvolution-based methods, among others. Most of the post-processing software used in preclinical studies is home-built and custom-designed. Its use being, in most cases, limited to the institution responsible for the development. In this study, we designed a tool that performs the hemodynamic quantification process quickly and in a reliable way for research purposes. Methods: The DSC-MRI quantification tool, developed as a Python project, performs the basic mathematical steps to generate the parametric maps: cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), signal recovery (SR), and percentage signal recovery (PSR). For the validation process, a data set composed of MRI rat brain scans was evaluated: i) healthy animals, ii) temporal blood-brain barrier (BBB) dysfunction, iii) cerebral chronic hypoperfusion (CCH), iv) ischemic stroke, and v) glioblastoma multiforme (GBM) models. The resulting perfusion parameters were then compared with data retrieved from the literature. Results: A total of 30 animals were evaluated with our DSC-MRI quantification tool. In all the models, the hemodynamic parameters reported from the literature are reproduced and they are in the same range as our results. The Bland-Altman plot used to describe the agreement between our perfusion quantitative analyses and literature data regarding healthy rats, stroke, and GBM models, determined that the agreement for CBV and MTT is higher than for CBF. Conclusion: An open-source, Python-based DSC post-processing software package that performs key quantitative perfusion parameters has been developed. Regarding the different animal models used, the results obtained are consistent and in good agreement with the physiological patterns and values reported in the literature. Our development has been built in a modular framework to allow code customization or the addition of alternative algorithms not yet implemented.

Periodontal inflammation is associated with increased circulating levels of endothelial progenitor cells: a retrospective cohort study in a high vascular risk population.

Background: One of the main biological mechanisms behind the link between periodontitis and atherosclerotic vascular diseases is vascular endothelial dysfunction. Particularly, circulating endothelial progenitor cells (EPCs) have been considered a biomarker of altered vascular endothelial function. Objectives: The aim of this study was to investigate relationship between periodontal inflammation and increased number of circulating EPCs. Design: This is retrospective cohort study. Methods: In this study, 85 elderly patients with a previous history of hypertension were followed up to 12 months. A baseline full-mouth periodontal assessment was carried out, and the amount of periodontal tissue inflamed per subject was calculated as a proxy of periodontal inflammation [periodontal inflamed surface area (PISA)]. The number of circulating EPCs (CD34+/CD133+/KDR+) was determined by flow cytometry from peripheral blood samples collected at baseline and 12 months. Results: Mean concentrations of CD34+/CD133+/KDR+ progenitor cells were higher in periodontitis patients than in those without periodontitis at baseline [55.4, 95% confidence interval (CI) = 20.8 to 90.0 versus 27.2, 95% CI = 13.6 to 40.8, p = 0.008] and 12 months (114.6, 95% CI = 53.5 to 175.7 versus 19.1, 95% CI = 10.8 to 27.4, p = 0.003). A significant increase over the follow-up was noticed in the group of subjects with periodontitis (p = 0.049) but not in the nonperiodontitis group (p = 0.819). PISA was independently associated with CD34+/CD133+/KDR+ EPCs at baseline (B coefficient = 0.031, 95% CI = 0.005 to 0.058; p = 0.021). The relationship between PISA and CD34+/CD133+/KDR+ EPCs at 12 months was confounded by increased baseline body mass index (B coefficient = 0.064, 95% CI = -0.005 to 0.132; p = 0.066). Conclusion: Periodontal inflammation is associated with high number of CD34+/CD133+/KDR+ EPCs, thus supporting a potential link between periodontitis and endothelial dysfunction.

C-Reactive Protein, Interleukin-6, and Vascular Recurrence After Stroke: An Individual Participant Data Meta-Analysis.

BACKGROUND: Anti-inflammatory therapies reduce recurrent vascular events in coronary disease. Existing studies have reported highly conflicting findings for the association of blood inflammatory markers with vascular recurrence after stroke leading to uncertainty about the potential of anti-inflammatory therapies after stroke and no consensus about the utility of measurement of inflammatory markers in current guidelines. METHODS: We investigated the association between hsCRP (high-sensitivity C-reactive protein), IL-6 (interluekin-6), and recurrent major adverse cardiovascular events (MACE), and stroke from individual participant data from 8420 patients with ischemic stroke/transient ischemic attack from 10 prospective studies. We did within-study multivariable regression analyses and then combined adjusted risk ratio (RR) by random-effects meta-analysis. RESULTS: During 18 920 person-years of follow-up, 1407 (16.7% [95% CI, 15.9-17.5]) patients had MACE and 1191 (14.1% [95% CI, 13.4-14.9]) patients had recurrent stroke. On bivariate analysis, baseline IL-6 was associated with MACE (RR, 1.26 [95% CI, 1.10-1.43]) and recurrent stroke (RR, 1.18 [95% CI, 1.05-1.32]), per unit increase logeIL-6. Similar associations were observed for hsCRP (MACE RR, 1.19 [95% CI, 1.09-1.29]; recurrent stroke RR, 1.12 [95% CI, 1.04-1.21], per unit increase logehsCRP). After adjustment for vascular risk factors and treatment, independent associations remained with MACE (IL-6, RR, 1.12 [95% CI, 1.04-1.21]; hsCRP, RR, 1.09 [95% CI, 1.04-1.15]) and recurrent stroke (IL-6, RR, 1.09 [95% CI, 1.00-1.19]; hsCRP, RR, 1.05 [95% CI, 1.00-1.11]). Comparing the top with the bottom quarters (Q4 versus Q1), IL-6 (RR, 1.35 [95% CI, 1.09-1.67]) and hsCRP (RR, 1.31 [95% CI, 1.07-1.61]) were associated with MACE after adjustment. Similar results were observed for recurrent stroke for IL-6 (RR, 1.33 [95% CI, 1.08-1.65]) but not hsCRP (RR, 1.16 [95% CI, 0.93-1.43]). CONCLUSIONS: Blood markers of inflammation were independently associated with vascular recurrence after stroke, strengthening the rationale for randomized trials of anti-inflammatory therapies for secondary prevention after ischemic stroke/TIA.

Periodontitis is associated with subclinical cerebral and carotid atherosclerosis in hypertensive patients: A cross-sectional study.

OBJECTIVE: To examine the relationship between periodontitis and subclinical intracranial atherosclerosis. The association of periodontitis with preclinical markers of atherosclerosis in other vascular territories was also explored. MATERIAL AND METHODS: This was a cross-sectional study where 97 elderly subjects with a previous history of hypertension received an ultrasonographic evaluation to assess subclinical atherosclerosis in different vascular territories: (1) cerebral [pulsatility (PI) and resistance index (RI) of the middle cerebral artery], (2) carotid [intima-media thickness (IMT)], and (3) peripheral [ankle-brachial index (ABI)]. Additionally, participants underwent a full-mouth periodontal assessment together with blood sample collection to determine levels of inflammatory biomarkers (leukocytes, fibrinogen, and erythrocyte sedimentation rate), lipid fractions (total cholesterol and high- and low-density lipoprotein), and glucose. RESULTS: Sixty-one individuals had periodontitis. Compared to subjects without periodontitis, those with periodontitis showed higher values of PI (1.24 ± 0.29 vs 1.01 ± 0.16), RI (0.70 ± 0.14 vs 0.60 ± 0.06), and IMT (0.94 ± 0.15 vs 0.79 ± 0.15) (all p < 0.001). No statistically significant differences were found neither for ABI or for other clinical and biochemical parameters. An independent association was found between periodontitis and increased intracranial atherosclerosis (ORadjusted = 10.16; 95% CI: 3.14-32.90, p < 0.001) and to a lesser extent with thicker carotid IMT (ORadjusted = 4.10; 95% CI: 1.61-10.48, p = 0.003). CONCLUSIONS: Periodontitis is associated with subclinical atherosclerosis in both intracranial and carotid arteries in elderly subjects with hypertension. CLINICAL RELEVANCE: The association of periodontitis with intracranial atherosclerosis implies that periodontitis patients might have greater chances to develop ischemic stroke in the future.

Influence of Temperature Chronobiology on Stroke Outcome.

The circadian system regulates numerous physiological variables, including body temperature. Additionally, a circadian patter has been described in stroke onset. Considering this, we hypothesised that the chronobiology of temperature may have an impact on stroke onset and functional outcomes. We also studied the variation of blood biomarkers according to stroke onset time. This is a retrospective observational study. Of the patients included, 2763 had a stroke between midnight and 8:00 h; 1571 between 8:00-14:00 h; and 655 between 14:00 h and midnight. Axillary temperature was measured at admission. At this time, blood samples were collected for biomarker analysis (TNF-α, IL-1ß, IL-6, IL-10, and glutamate). Temperature was higher in patients admitted from 8:00 h to midnight (p < 0.0001). However, the percentage of poor outcome at 3 months was highest in patients from midnight to 8:00 h (57.7%, p < 0.001). The association between temperature and mortality was highest during night time (OR: 2.79; CI 95%: 2.36-3.28; p < 0.001). These patients exhibited high glutamate (220.2 ± 140.2 µM), IL-6 (32.8 ± 14.3 pg/mL) and low IL-10 (9.7 ± 14.3 pg/mL) levels. Therefore, temperature chronobiology could have a significant impact on stroke onset and functional outcome. Superficial body hyperthermia during sleep seems to be more dangerous than during wakefulness. Further studies will be necessary to confirm our data.

Fibrin-Targeted Nanoparticles for Finding, Visualizing and Characterizing Blood Clots in Acute Ischemic Stroke.

Recanalization of the occluded artery is the gold standard treatment for acute ischemic stroke, which includes enzymatic fibrinolytic treatment with the use of recombinant tissue plasminogen activators (rtPAs) to disrupt the occluding clot, the use of mechanical thrombectomy to physically remove the clot, or a combination of both. Fibrin is one of the main components of blood clots causing ischemic stroke and is the target of rtPA upon activation of plasminogen in the clot. In addition, fibrin content also influences the efficacy of mechanical thrombectomy. Current imaging methods can successfully identify occlusions in large vessels; however, there is still a need for contrast agents capable of visualizing small thrombi in ischemic stroke patients. In this work, we describe the synthesis and the in vitro characterization of a new diagnostic nanoparticle, as well as the in vivo evaluation in an animal model of thromboembolic stroke. Gd-labeled KCREKA peptides were synthesized and attached onto the surface of PEGylated superparamagnetic nanoparticles. Magnetic resonance imaging (MRI) of blood clots was performed in vitro and in vivo in animal models of thromboembolic stroke. KCREKA-NPs were synthesized by attaching the peptide to the amino (N) termini of the PEG-NPs. The sizes of the nanoparticles, measured via DLS, were similar for both KCREKA-NPs and PEG-NPs (23 ± 4 nm, PDI = 0.11 and 25 ± 8 nm, PDI = 0.24, respectively). In the same line, r2 relaxivities were also similar for the nanoparticles (149 ± 2 mM Fe s−1 and 151 ± 5 mM Fe s−1), whereas the r1 relaxivity was higher for KCREKA-NPs (1.68 ± 0.29 mM Fe s−1 vs. 0.69 ± 0.3 mM Fe s−1). In vitro studies showed that blood clots with low coagulation times were disrupted by rtPA, whereas aged clots were almost insensitive to the presence of rtPA. MRI in vitro studies showed a sharp decrease in the T1 × T2 signals measured for aged clots incubated with KCREKA-NPs compared with fresh clots (47% [22, 80] to 26% [15, 51]). Furthermore, the control blood showed a higher value of the T1 × T2 signal (39% [20, 61]), being the blood clots with low coagulation times the samples with the lowest values measured by MRI. In vivo studies showed a significant T1 × T2 signal loss in the clot region of 24% after i.v. injection of KCREKA-NPs. The thrombus age (2.5% ± 6.1% vs. 81.3% ± 19.8%, p < 0.01) confirmed our ability to identify in vivo fresh blood clots. In this study, we developed and tested a dual MRI nanoparticle, acting as T1 and T2 contrast agents in MRI analyses. The developed KCREKA-NPs showed affinity for the fibrin content of blood clots, and the MRI signals provided by the nanoparticles showed significant differences depending on the clot age. The developed KCREKA-NPs could be used as a tool to predict the efficacy of a recanalization treatment and improve the triage of ischemic stroke patients.

Need for a Paradigm Shift in the Treatment of Ischemic Stroke: The Blood-Brain Barrier.

Blood-brain barrier (BBB) integrity is essential to maintaining brain health. Aging-related alterations could lead to chronic progressive leakiness of the BBB, which is directly correlated with cerebrovascular diseases. Indeed, the BBB breakdown during acute ischemic stroke is critical. It remains unclear, however, whether BBB dysfunction is one of the first events that leads to brain disease or a down-stream consequence. This review will focus on the BBB dysfunction associated with cerebrovascular disease. An added difficulty is its association with the deleterious or reparative effect, which depends on the stroke phase. We will first outline the BBB structure and function. Then, we will focus on the spatiotemporal chronic, slow, and progressive BBB alteration related to ischemic stroke. Finally, we will propose a new perspective on preventive therapeutic strategies associated with brain aging based on targeting specific components of the BBB. Understanding BBB age-evolutions will be beneficial for new drug development and the identification of the best performance window times. This could have a direct impact on clinical translation and personalised medicine.

Surrogate biomarkers of outcome for wake-up ischemic stroke.

BACKGROUND: Wake-up ischemic stroke (IS) has been usually excluded from acute stroke therapy options for being outside of the safe treatment window. We identified risk factors, and clinical or molecular biomarkers that could be therapeutic targets for wake-up stroke prevention, thus hopefully leading to a decrease in its mortality and disability in medium to long-term outcome. METHODS: 4251 ischemic stroke (IS) patients from a prospectively registered database were recruited; 3838 (90.3%) had known onset-symptom time, and 413 (9.7%) were wake-up strokes. The main endpoint was to analyze the association between different serum biomarkers with wake-up IS episodes and their progression. Leukocytes count, serum levels of C-reactive protein, fibrinogen, interleukin 6 (IL-6), and vitamin D were analyzed as inflammation biomarkers; N-terminal pro-B-type Natriuretic-Peptide and microalbuminuria, used as atrial/endothelial dysfunction biomarkers; finally, glutamate levels as excitotoxicity biomarker. In addition, demographic, clinical and neuroimaging variables associated with the time-evolution of wake-up IS patients and functional outcome at 3 months were evaluated. Good and poor functional outcome were defined as mRS ≤2 and mRS > 2 at 3 months, respectively. RESULTS: Wake-up IS showed a poorer outcome at 3-months than in patients with known on-set-symptom time (59.1% vs. 48.1%; p < 0.0001). Patients with wake-up IS had higher levels of inflammation biomarkers; IL-6 levels at admission (51.5 ± 15.1 vs. 27.8 ± 18.6 pg/ml; p < 0.0001), and low vitamin D levels at 24 h (5.6 ± 5.8 vs. 19.2 ± 9.4 ng/ml; p < 0.0001) are worthy of attention. In a logistic regression model adjusted for vitamin D, OR was 15.1; CI 95%: 8.6-26.3, p < 0.0001. However, we found no difference in vitamin D levels between patients with or without clinical-DWI mismatch (no: 18.95 ± 9.66; yes: 17.84 ± 11.77 ng/mL, p = 0.394). No difference in DWI volume at admission was found (49.3 ± 96.9 ml in wake-up IS patients vs. 51.7 ± 98.2 ml in awake IS patients; p = 0.895). CONCLUSIONS: Inflammatory biomarkers are the main factors that are strongly associated with wake-up IS episodes. Wake-up IS is associated with lower vitamin D levels. These data indicate that vitamin D deficiency could become a therapeutic target to reduce wake-up IS events.

Antihyperthermic Treatment in the Management of Malignant Infarction of the Middle Cerebral Artery.

Malignant infarction of the middle cerebral artery (m-MCA) is a complication of ischemic stroke. Since hyperthermia is a predictor of poor outcome, and antihyperthermic treatment is well tolerated, our main aim was to analyze whether the systemic temperature decrease within the first 24 h was associated with a better outcome. Furthermore, we studied potential biochemical and neuroimaging biomarkers. This is a retrospective observational analysis that included 119 patients. The temperature variations within the first 24 h were recorded. Biochemical laboratory parameters and neuroimaging variables were also analyzed. The temperature increase at the first 24 h (OR: 158.97; CI 95%: 7.29−3465.61; p < 0.001) was independently associated with a higher mortality. Moreover, antihyperthermic treatment (OR: 0.08; CI 95%: 0.02−0.38; p = 0.002) was significantly associated with a good outcome at 3 months. Importantly, antihyperthermic treatment was associated with higher survival at 3 months (78% vs. 50%, p = 0.003). Significant independently associations between the development of m-MCA and both microalbuminuria (OR: 1.01; CI 95%: 1.00−1.02; p = 0.005) and leukoaraiosis (OR: 3.07; CI 1.84−5.13−1.02; p < 0.0001) were observed. Thus, antihyperthermic treatment within the first 24 h was associated with both a better outcome and higher survival. An increased risk of developing m-MCA was associated with leukoaraiosis and an elevated level of microalbuminuria.

Involvement of Ceramide Metabolism in Cerebral Ischemia.

Ischemic stroke, caused by the interruption of blood flow to the brain and subsequent neuronal death, represents one of the main causes of disability in worldwide. Although reperfusion therapies have shown efficacy in a limited number of patients with acute ischemic stroke, neuroprotective drugs and recovery strategies have been widely assessed, but none of them have been successful in clinical practice. Therefore, the search for new therapeutic approaches is still necessary. Sphingolipids consist of a family of lipidic molecules with both structural and cell signaling functions. Regulation of sphingolipid metabolism is crucial for cell fate and homeostasis in the body. Different works have emphasized the implication of its metabolism in different pathologies, such as diabetes, cancer, neurodegeneration, or atherosclerosis. Other studies have shown its implication in the risk of suffering a stroke and its progression. This review will highlight the implications of sphingolipid metabolism enzymes in acute ischemic stroke.

The Smoking Paradox in Stroke Patients Under Reperfusion Treatment Is Associated With Endothelial Dysfunction.

Objective: This study aimed to explore the association between smoking habit and the serum levels of soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK), in relation with the functional outcome of patients with acute ischemic stroke undergoing reperfusion treatment. Methods: Observational and retrospective study of a series of patients with acute ischemic stroke subjected to reperfusion treatments. Clinical, analytical, and neuroimaging parameters were analyzed. The main endpoint was the functional outcome at 3 months, measured by the modified Ranking Scale (mRS). Logistic regression models were used to analyze the association between smoking and sTWEAK levels with functional outcome and leukoaraiosis. Results: The results showed that smoking habit was associated with a good functional outcome at 3 months in patients with stroke (OR: 3.52; 95% CI: 1.03-11.9; p = 0.044). However, this independent association was lost after adjusting by sTWEAK levels (OR 1.73; 95% CI: 0.86-13.28; p = 0.116). sTWEAK levels were significantly lower in smoker patients [4015.5 (973.66-7921.83) pg/ml vs. 5,628 (2,848-10,202) pg/ml, p < 0.0001], while sTWEAK levels were significantly higher in patients with poor functional outcomes at 3 months [10,284 (7,388-13.247) pg/ml vs. 3,405 (2,329-6,629) pg/ml, p < 0.0001]. Conclusion: The decrease in sTWEAK levels was associated with a good functional outcome in smoker patients with stroke undergoing reperfusion therapy.

Stress Granules and Acute Ischemic Stroke: Beyond mRNA Translation.

Ischemic stroke is a leading cause of death and disability worldwide. Following an ischemic insult, cells undergo endoplasmic reticulum (ER) stress, which increases the ER's protein-folding and degradative capacities and blocks the global synthesis of proteins by phosphorylating the eukaryotic translation initiation factor 2-alpha (eIF2α). Phosphorylation of eIF2α is directly related to the dynamics of stress granules (SGs), which are membraneless organelles composed of RNA-binding proteins and mRNA. SGs play a critical role in mRNA metabolism and translational control. Other translation factors are also linked to cellular pathways, including SG dynamics following a stroke. Because the formation of SGs is closely connected to mRNA translation, it is interesting to study the relationship between SG dynamics and cellular outcome in cases of ischemic damage. Therefore, in this review, we focus on the role of SG dynamics during cerebral ischemia.

Associations between RNA-Binding Motif Protein 3, Fibroblast Growth Factor 21, and Clinical Outcome in Patients with Stroke.

BACKGROUND: RNA-binding motif protein 3 (RBM3) is a cold-induced marker of good functional outcome of ischemic stroke that is promising as a protective target. Fibroblast growth factor 21 (FGF21) is an obesity- and temperature-related hormone that upregulates the expression of RBM3, which is beneficial as a recombinant treatment and has been tested under different experimental pathological conditions, including stroke. However, the interaction between RBM3 and FGF21 has not yet been tested for clinical stroke conditions. METHODS: In a sample of 66 stroke patients, we analyzed the associations between the FGF21 and RBM3 serum concentrations on admission and at 72 h, body weight, maximum temperature during the first 24 h, and the outcome of patients at 3 months. We also analyzed their association with biomarkers of obesity (adiponectin and leptin) and inflammation (interleukin-6 (IL-6) and interleukin (IL-10)). RESULTS: Higher concentrations of FGF21 on admission and RBM3 at 72 h were associated with good outcomes. Serum FGF21 and RBM3 were directly related to body mass index and inversely related to the maximum temperature during the first 24 h. We found a positive association between the FGF21 concentrations in obese patients with leptin and a negative correlation with adiponectin in non-obese participants. CONCLUSIONS: This clinical study demonstrates the association between RBM3 and FGF21 levels and the outcome of stroke patients. Although further investigations are required, these data support the pharmacological induction of RBM3 as a promising protective therapy.

Sonosensitive capsules for brain thrombolysis increase ischemic damage in a stroke model.

BACKGROUND: Ischemic stroke is the most common cerebrovascular disease and is caused by interruption of blood supply to the brain. To date, recombinant tissue plasminogen activator (rtPA) has been the main pharmacological treatment in the acute phase. However, this treatment has some drawbacks, such as a short half-life, low reperfusion rate, risk of hemorrhagic transformations, and neurotoxic effects. To overcome the limitations of rtPA and improve its effectiveness, we recently designed sonosensitive sub-micrometric capsules (SCs) loaded with rtPA with a size of approximately 600 nm, synthesized using the layer-by-layer (LbL) technique, and coated with gelatine for clot targeting. In this study, we evaluated the rtPA release of ultrasound (US)-responsive SCs in healthy mice and the therapeutic effect in a thromboembolic stroke model. RESULTS: In healthy mice, SCs loaded with rtPA 1 mg/kg responded properly to external US exposure, extending the half-life of the drug in the blood stream more than the group treated with free rtPA solution. The gelatine coating also contributed to stabilizing the encapsulation and maintaining the response to US. When the same particles were administered in the stroke model, these SCs appeared to aggregate in the ischemic brain region, probably generating secondary embolisms and limiting the thrombolytic effect of rtPA. Despite the promising results of these thrombolytic particles, at least under the dose and size conditions used in this study, the administration of these capsules represents a risk factor for stroke. CONCLUSIONS: This is the first study to report the aggregation risk of a drug carrier in neurological pathologies such as stroke. Biocompatibility analysis related to the use of nano-and microparticles should be deeply studied to anticipate the limitations and orientate the design of new nanoparticles for translation to humans.