Biomarkers for stroke

A Comprehensive Review of Cryptogenic Stroke and Atrial Fibrillation: Real-World Insights Into the Role of Insertable Cardiac Monitors

Cryptogenic stroke, a subtype of ischemic stroke with no identifiable cause after comprehensive evaluation, presents a unique challenge in stroke prevention. Atrial fibrillation (AF), a common risk factor for ischemic stroke, is often underdiagnosed in these patients due to its intermittent, asymptomatic nature. Early detection of AF is critical, as anticoagulation therapy significantly reduces the risk of recurrent stroke in AF patients. However, traditional short-term monitoring methods frequently fail to identify paroxysmal AF. Insertable cardiac monitors (ICMs) offer a novel solution by providing continuous, long-term heart rhythm monitoring, which has proven effective in detecting occult AF. Real-world data further support the clinical value of ICMs in guiding the initiation of anticoagulation therapy, ultimately improving stroke prevention strategies. Despite some limitations, such as false positives and the invasive nature of the device, ICMs have emerged as a critical tool in modern stroke management. As technology evolves, future advancements may further enhance AF detection by integrating artificial intelligence and wearable devices. This review provides a comprehensive overview of the role of AF in cryptogenic stroke, the importance of early detection, and the growing significance of ICMs in clinical practice.

Epidemiology, Pathophysiology, and Imaging of Atherosclerotic Intracranial Disease

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of stroke worldwide. Among people with stroke, those of East Asia descent and non-White populations in the United States have a higher burden of ICAD-related stroke compared with Whites of European descent. Disparities in the prevalence of asymptomatic ICAD are less marked than with symptomatic ICAD. In addition to stroke, ICAD increases the risk of dementia and cognitive decline, magnifying ICAD societal burden. The risk of stroke recurrence among patients with ICAD-related stroke is the highest among those with confirmed stroke and stenosis ≥70%. In fact, the 1-year recurrent stroke rate of >20% among those with stenosis >70% is one of the highest rates among common causes of stroke. The mechanisms by which ICAD causes stroke include plaque rupture with in situ thrombosis and occlusion or artery-to-artery embolization, hemodynamic injury, and branch occlusive disease. The risk of stroke recurrence varies by the presumed underlying mechanism of stroke, but whether techniques such as quantitative magnetic resonance angiography, computed tomographic angiography, magnetic resonance perfusion, or transcranial Doppler can help with risk stratification beyond the degree of stenosis is less clear. The diagnosis of ICAD is heavily reliant on lumen-based studies, such as computed tomographic angiography, magnetic resonance angiography, or digital subtraction angiography, but newer technologies, such as high-resolution vessel wall magnetic resonance imaging, can help distinguish ICAD from stenosing arteriopathies.

An Intensive Exercise Program Using a Technology-Enriched Rehabilitation Gym for the Recovery of Function in People With Chronic Stroke: Usability Study

BACKGROUND

Rehabilitation improves poststroke recovery with greater effect for many when applied intensively within enriched environments. The failure of health care providers to achieve minimum recommendations for rehabilitation motivated the development of a technology-enriched rehabilitation gym (TERG) that enables individuals under supervision to perform high-intensity self-managed exercises safely in an enriched environment.

OBJECTIVE

This study aimed to assess the feasibility of the TERG approach and gather preliminary evidence of its effect for future research.

METHODS

This feasibility study recruited people well enough to exercise but living with motor impairment following a stroke at least 12 months previously. Following assessment, an 8-week exercise program using a TERG (eg, virtual reality treadmills, power-assisted equipment, balance trainers, and upper limb training systems) was structured in partnership with participants. The feasibility was assessed through recruitment, retention, and adherence rates along with participant interviews. Effect sizes were calculated from the mean change in standard outcome measures.

RESULTS

In total, 70 individuals registered interest, the first 50 were invited for assessment, 39 attended, and 31 were eligible and consented. Following a pilot study (n=5), 26 individuals (mean age 60.4, SD 13.3 years; mean 39.0, SD 29.2 months post stroke; n=17 males; n=10 with aphasia) were recruited to a feasibility study, which 25 individuals completed. Participants attended an average of 18.7 (SD 6.2) sessions with an 82% attendance rate. Reasons for nonattendance related to personal life, illness, weather, care, and transport. In total, 19 adverse events were reported: muscle or joint pain, fatigue, dizziness, and viral illness, all resolved within a week. Participants found the TERG program to be a positive experience with the equipment highly usable albeit with some need for individual tailoring to accommodate body shape and impairment. The inclusion of performance feedback and gamification was well received. Mean improvements in outcome measures were recorded across all domains with low to medium effect sizes.

CONCLUSIONS

This study assessed the feasibility of a holistic technology-based solution to the gap between stroke rehabilitation recommendations and provision. The results clearly demonstrate a rehabilitation program delivered through a TERG is feasible in terms of recruitment, retention, adherence, and user acceptability and may lead to considerable improvement in function, even in a chronic stroke population.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-doi.org/10.3389/fresc.2021.820929.

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-1β, 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.

Leukoaraiosis as a Predictor of Depression and Cognitive Impairment among Stroke Survivors: A Systematic Review

Stroke survivors are at increased risk of developing depression and cognitive decline. Thus, it is crucial for both clinicians and stroke survivors to be provided with timely and accurate prognostication of post-stroke depression (PSD) and post-stroke dementia (PSDem). Several biomarkers regarding stroke patients' propensity to develop PSD and PSDem have been implemented so far, leukoaraiosis (LA) being among them. The purpose of the present study was to review all available work published within the last decade dealing with pre-existing LA as a predictor of depression (PSD) and cognitive dysfunction (cognitive impairment or PSDem) in stroke patients. A literature search of two databases (MEDLINE and Scopus) was conducted to identify all relevant studies published between 1 January 2012 and 25 June 2022 that dealt with the clinical utility of preexisting LA as a prognostic indicator of PSD and PSDem/cognitive impairment. Only full-text articles published in the English language were included. Thirty-four articles were traced and are included in the present review. LA burden, serving as a surrogate marker of "brain frailty" among stroke patients, appears to be able to offer significant information about the possibility of developing PSD or cognitive dysfunction. Determining the extent of pre-existing white matter abnormalities can properly guide decision making in acute stroke settings, as a greater degree of such lesioning is usually coupled with neuropsychiatric aftermaths, such as PSD and PSDem.

Circulating Thrombomodulin: Release Mechanisms, Measurements, and Levels in Diseases and Medical Procedures

Thrombomodulin (TM) is a type-I transmembrane protein that is mainly expressed on endothelial cells and plays important roles in many biological processes. Circulating TM of different forms are also present in biofluids, such as blood and urine. Soluble TM (sTM), comprised of several domains of TM, is the major circulating TM which is generated by either enzymatic or chemical cleavage of the intact protein under different conditions. Under normal conditions, sTM is present in low concentrations (<10 ng/mL) in the blood but is elevated in several pathological conditions associated with endothelial dysfunction such as cardiovascular, inflammatory, infection, and metabolic diseases. Therefore, sTM level has been examined for monitoring disease development, such as disseminated intravascular coagulation (DIC), sepsis and multiple organ dysfunction syndrome in patients with novel coronavirus disease 2019 (COVID-19) recently. In addition, microvesicles (MVs) that contain membrane TM (MV-TM) have been found to be released from activated cells which also contribute to levels of circulating TM in certain diseases. Several release mechanisms of sTM and MV-TM have been reported, including enzymatic, chemical, and TM mutation mechanisms. Measurements of sTM and MV-TM have been developed and explored as biomarkers in many diseases. In this review, we summarize all these advances in three categories as follows: (1) release mechanisms of circulating TM, (2) methods for measuring circulating TM in biological samples, and (3) correlation of circulating TM with diseases. Altogether, it provides a whole picture of recent advances on circulating TM in health and disease.

Impact of Exercise on Cerebrovascular Physiology and Risk of Stroke

Ischemic heart disease and stroke are the number 1 and number 2 causes of death worldwide, respectively. A lifelong commitment to exercise reduces the risk of these adverse events and is also associated with several cardiometabolic improvements, including reductions in blood pressure, cholesterol, and inflammatory markers, as well as improved glucose control. Routine exercise also reduces the risk of developing comorbidities that increase the risk of cardiovascular or cerebrovascular disease. While the benefits of a lifelong commitment to exercise are well documented, there is a complex interaction between exercise and stroke risk, such that the risk of ischemic or hemorrhagic stroke may increase acutely during or immediately following exercise. In this article, we discuss the physiological responses to different types of exercise, as well as the determinants of resting and exertional cerebrovascular perfusion, and explore the complex interaction between atrial fibrillation, exercise, and stroke risk. Finally, we highlight the increased risk of stroke during different types of exercise, as well as factors that may alleviate this risk.

Comparison of stroke cases with other neurological diseases on the basis of haemogram parameters

AIMS

This study aimed to examine the haemogram parameters, including the neutrophil/lymphocyte ratio (NLR), which is fast, easy and practical to determine, in stroke patients who present with more physiological stress and inflammation and compare them with patients presenting other neurological diseases.

METHODS

The demographic, laboratory and imaging features of all patients who were admitted to the neurology clinic within a three-year period and met the study criteria were retrospectively analysed. A haemogram from peripheral venous blood samples was taken at the time of admission, and its parameters was calculated.

RESULTS

A total of 3152 patients, 1604 of whom were women (50.9%), with a mean age of 66.1 ± 14 (18-100) years who were hospitalised in the neurology clinic from 1 January 2015 to 1 January 2018, comprised the study's sample. Mean age, mean leukocyte-neutrophil count and NLR were significantly higher in stroke patients than in those without stroke (P < .001, P < .001 and P < .001, respectively), but mean red blood cell, platelet and lymphocyte counts, and haemoglobin and haematocrit values were found to be significantly lower (P < .001, P < .001, P < .001, P < .001 and P < .001, respectively). When the haemogram parameters were compared according to stroke type, red blood cell, haemoglobin, haematocrit and NLR values in patients with haemorrhagic stroke (P = .019, P = .002, P = .002 and P = .001, respectively) and platelet and lymphocyte values in ischaemic stroke patients were found to be significantly higher (P = .002 and P < .001, respectively).

CONCLUSION

In this study, significant data obtained by comparing the haemogram parameters of those with stroke and other neurological diseases are presented. All neurological diseases, especially acute stroke and its types, should be examined in future prospective, randomised and controlled studies with all haemogram parameters, especially the NLR. However, it should be noted that haematological parameters are more useful for group studies rather than determining the diagnosis of an individual patient.

Interhemispheric Cortical Network Connectivity Reorganization Predicts Vision Impairment in Stroke

Stroke is one of the main causes of disability in human beings, and when the occipital lobe is affected, this leads to partial vision loss (homonymous hemianopia). To understand brain mechanisms of vision loss and recovery, graph theory-based brain functional connectivity network (FCN) analysis was recently introduced. However, few brain network studies exist that have studied if the strength of the damaged FCN can predict the extent of functional impairment. We now characterized the brain FCN using deep neural network analysis to describe multiscale brain networks and explore their corresponding physiological patterns. In a group of 24 patients and 24 controls, Bi-directional long short-term memory (Bi-LSTM) was evaluated to reveal the cortical network pattern learning efficiency compared with other traditional algorithms. Bi-LSTM achieved the best balanced-overall accuracy of 73% with sensitivity of 70% and specificity and 75% in the low alpha band. This demonstrates that bi-directional learning can capture the brain network feature representation of both hemispheres. It shows that brain damage leads to reorganized FCN patterns with a greater number of functional connections of intermediate density in the high alpha band. Future studies should explore how this understanding of brain FCN can be used for clinical diagnostics and rehabilitation.

Change and predictive ability of circulating immunoregulatory lymphocytes in long-term outcomes of acute ischemic stroke

Lymphocytes play an important role in the immune response after stroke. However, our knowledge of the circulating lymphocytes in ischemic stroke is limited. Herein, we collected the blood samples of clinical ischemic stroke patients to detect the change of lymphocytes from admission to 3 months after ischemic stroke by flow cytometry. A total of 87 healthy controls and 210 patients were enrolled, and the percentages of circulating T cells, CD4⁺ T cells, CD8⁺ T cells, double negative T cells (DNTs), CD4⁺ regulatory T cells (Tregs), CD8⁺ Tregs, B cells and regulatory B cells (Bregs) were measured. Among patients, B cells, Bregs and CD8⁺ Tregs increased significantly, while CD4⁺ Tregs dropped and soon reversed after ischemic stroke. CD4⁺ Tregs, CD8⁺ Tregs, and DNTs also showed high correlations with the infarct volume and neurological scores of patients. Moreover, these lymphocytes enhanced the predictive ability of long-term prognosis of neurological scores when added to basic clinical information. The percentage of CD4⁺ Tregs within lymphocytes showed high correlations with both acute and long-term neurological outcomes, which exhibited a great independent predictive ability. These findings suggest that CD4⁺ Tregs can be a biomarker to predict stroke outcomes and improve existing therapeutic strategies of immunoregulatory lymphocytes.

Engineering 3D Cortical Spheroids for an In Vitro Ischemic Stroke Model

Three-dimensional (3D) spheroids composed of brain cells have shown great potential to mimic the pathophysiology of the brain. However, a 3D spheroidal brain-disease model for cerebral ischemia has not been reported. This study investigated an ultralow attachment (ULA) surface-mediated formation of 3D cortical spheroids using primary rat cortical cells to recapitulate the cerebral ischemic responses in stroke by oxygen-glucose deprivation-reoxygenation (OGD-R) treatment. Comparison between two-dimensional (2D) and 3D cell culture models confirmed the better performance of the 3D cortical spheroids as normal brain models. The cortical cells cultured in 3D maintained their healthy physiological morphology of a less activated state and suppressed mRNA expressions of pathological stroke markers, S100B, IL-1β, and MBP, selected based on in vivo stroke model. Interestingly, the spheroids formed on the ULA surface exhibited striking aggregation dynamics involving active cell-substrate interactions, whereas those formed on the agarose surface aggregated passively by the convective flow of the media. Accordingly, ULA spheroids manifested a layered arrangement of neurons and astrocytes with higher expressions of integrin β1, integrin α5, N-cadherin, and fibronectin than the agarose spheroids. OGD-R-induced stroke model of the ULA spheroids successfully mimicked the ischemic response as evidenced by the upregulated mRNA expressions of the key markers for stroke, S100B, IL-1β, and MBP. Our study suggested that structurally and functionally distinct cortical spheroids could be generated by simply tuning the cell-substrate binding activities during dynamic spheroidal formation, which should be an essential factor to consider in establishing a brain-disease model.

Long non-coding RNA H19 expression and functional polymorphism rs217727 are linked to increased ischemic stroke risk

Background

Efforts to identify potential biomarkers for the diagnosis of ischemic stroke (IS) are valuable. The H19 gene plays a functional role in increasing the prevalence of IS risk factors. We evaluated the correlation between H19 rs217727 polymorphism and the expression level of H19 lncRNA with susceptibility to IS among the Iranian population.

Methods

Blood samples were collected from IS patients (n = 114) and controls (n = 114). We concentrated on the expression pattern of H19 at different time points (i.e., 0–24, 24–48, and 48–72 h after stroke). The tetra-amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) method was applied for DNA genotyping. We used the quantitative real-time PCR to evaluate H19 expression levels. We used the receiver operating characteristic (ROC) curve to evaluate the diagnosis and prognosis of IS.

Results

The rs217727polymorphism of H19 was related with IS susceptibility in the co-dominant (OR = 2.92, 95% CI = 0.91–10.92, P = 0.04) and recessive models (OR = 2.80, 95% CI = 0.96–8.15, P = 0.04). H19 expression was significantly upregulated in IS and remained high for 72 h after stroke. ROC curves showed that H19 expression within the first 24 h from stroke onset might serve as a biomarker for the early diagnosis of IS with 79.49% sensitivity and 80.00% specificity. H19 expression in small vessel occlusion (SVO) and large-artery atherosclerosis (LAA) patients were 3.74 and 3.34 times higher than the undetermined (UD) subtype, respectively [OR = 3.74 95% CL (1.14–12.27) P = 0.030 and OR = 3.34 95% CL (1.13–9.85) P = 0.029].

Conclusion

The rs217727 polymorphism of the H19 is correlated with IS susceptibility, and H19 expression levels were higher in SVO and LAA patients. The upregulation of H19 may be considered as a diagnostic biomarker in IS among the Iranian population, but it cannot serve as a useful prognostic marker.

Statin Effects in Atrial Fibrillation-Related Stroke: A Systematic Review and Meta-Analysis

Background: Statins lower the risk of recurrent stroke and mortality and improve outcomes in patients with ischemic stroke. However, the effects of statins on atrial fibrillation (AF)-related stroke are not well-established. Our study aims to investigate the effects of statin therapy on the clinical outcomes in patients with AF-related stroke.

Methods: Electronic databases (MEDLINE, Embase, and Scopus) were searched for previous studies on the effects of pre- and post-stroke statins on the clinical outcomes in AF-related stroke patients. The primary outcome was all-cause mortality. Secondary outcomes included recurrent ischemic stroke, acute coronary events, major adverse cardiovascular events (MACE), and short-term functional outcomes. We extracted hazard ratios (HRs) or odds ratios (ORs) with 95% confidence interval (CI) from each study and pooled them through a meta-analysis.

Results: A total of eight studies (five on post-stroke statins and three on pre-stroke statins) with 12,216 patients were included in the analysis. Post-stroke statin therapy reduced the risk of all-cause mortality (HR, 0.63; 95% CI, 0.55–0.74). This beneficial effect was sustained regardless of statin intensity. However, no significant associations were observed between statin therapy and a reduction in the risk of recurrent ischemic stroke, acute coronary events, or MACE. Pre-stroke statin use was associated with a lower risk of poor short-term functional outcomes (OR, 0.63; 95% CI, 0.47–0.85).

Conclusions: Statin therapy for AF-related stroke may reduce all-cause mortality and improve functional outcomes. Randomized controlled studies are warranted to confirm the effects of statins on the outcomes of AF-related stroke.

Neurovascular Unit as a Source of Ischemic Stroke Biomarkers-Limitations of Experimental Studies and Perspectives for Clinical Application

Cerebral stroke, which is one of the most frequent causes of mortality and leading cause of disability in developed countries, often leads to devastating and irreversible brain damage. Neurological and neuroradiological diagnosis of stroke, especially in its acute phase, is frequently uncertain or inconclusive. This results in difficulties in identification of patients with poor prognosis or being at high risk for complications. It also makes difficult identification of these stroke patients who could benefit from more aggressive therapies. In contrary to the cardiovascular disease, no single biomarker is available for the ischemic stroke, addressing the abovementioned issues. This justifies the need for identifying of effective diagnostic measures characterized by high specificity and sensitivity. One of the promising avenues in this area is studies on the panels of biomarkers characteristic for processes which occur in different types and phases of ischemic stroke and represent all morphological constituents of the brains' neurovascular unit (NVU). In this review, we present the current state of knowledge concerning already-used or potentially applicable biomarkers of the ischemic stroke. We also discuss the perspectives for identification of biomarkers representative for different types and phases of the ischemic stroke, as well as for different constituents of NVU, which concentration levels correlate with extent of brain damage and patients' neurological status. Finally, a critical analysis of perspectives on further improvement of the ischemic stroke diagnosis is presented.

Association of plasma level of growth differentiation factor-15 and clinical outcome after intraarterial thrombectomy

BACKGROUND AND PURPOSE

As intraarterial thrombectomy (IAT) has been actively practiced, blood biomarkers that can predict outcomes after IAT have drawn attention. Growth differentiation factor-15 (GDF-15) is a stress-responsive cytokine and the levels are increased during inflammation or other pathological conditions of various tissues, including the brain. However, GDF-15 levels have not been reported as a biomarker for IAT outcomes. This study was performed to evaluate whether GDF-15 was related to the extent of brain damage and whether it could predict patient prognosis after IAT.

METHODS

Patients who showed large arterial occlusion and significant diffusion-perfusion mismatch on imaging underwent IAT. A total of 62 patients who underwent IAT and had blood samples for GDF-15 measurements were enrolled from July 2013 to May 2015. We assessed the infarct severity by consecutive changes on the National Institutes of Health Stroke Scale (NIHSS) during admission and the size of the infarction on brain imaging. Modified Rankin Scale scores (mRS) from 0 to 2 were considered good outcomes, representing functional independence at discharge and three months later.

RESULTS

The levels of GDF-15 at the time of admission were significantly correlated with the NIHSS scored at 24 hours (r = 0.306, p = 0.016), three days after IAT (r = 0.261, p = 0.041), and at discharge (r = 0.266, p = 0.037), as well as the infarct size on diffusion-weighted image taken 24 h after IAT (r = 0.452, p = 0.001), but the levels were not correlated with the initial NIHSS or the infarct size before IAT. Multiple logistic regression showed that GDF-15 levels were an independent predictor of functional independence (mRS 0 - 2) at discharge (p = 0.028) and three months after IAT (p = 0.019). Other factors that could predict prognosis were good collateral status on the initial brain angiography and rapid recanalization within six hours from symptom onset.

CONCLUSION

The GDF-15 level at the time of admission showed a significant positive correlation with the severity of cerebral damage and clinical outcome after IAT. This suggests that GDF-15 can provide useful prognostic information for patients who successfully underwent IAT in an emergency setting.

Cell Therapy for Ischemic Stroke: How to Turn a Promising Preclinical Research into a Successful Clinical Story

Stroke is a major public health issue with limited treatment. The pharmacologically or mechanically removing of the clot is accessible to less than 10% of the patients. Stem cell therapy is a promising alternative strategy since it increases the therapeutic time window but many issues remain unsolved. To avoid a new dramatic failure when translating experimental data on the bedside, this review aims to highlight the indispensable checkpoints to make a successful clinical trial based on the current preclinical literature. The large panel of progenitors/ stem cells at the researcher's disposal is to be used wisely, regarding the type of cells, the source of cells, the route of delivery, the time window, since it will directly affect the outcome. Mechanisms are still incompletely understood, although recent studies have focused on the inflammation modulation of most cells types.

Intracranial Atherosclerotic Stenoses: Pathophysiology, Epidemiology, Risk Factors and Current Therapy Options

Intracranial atherosclerotic stenoses (ICAS) are one of the most common causes of first and recurrent cerebrovascular ischaemic events worldwide, with highest prevalence in Asian, Hispanic and African populations. Clinical trials have improved the understanding of epidemiology, risk factors and imaging characteristics of patients with ICAS. Current therapeutic approaches concerning these patients include management of risk factors, best medical therapy, potentially endovascular and rarely surgical therapy. In our review, we elucidate the current epidemiology and evidence in evaluation of risk factors and therapeutic options for providing favourable outcome for patients with ICAS.

Global metabolomics analysis of serum from humans at risk of thrombotic stroke

We aimed to determine the serum concentrations of altered compounds to understand the changes in metabolism and pathophysiology that occur prior to thrombotic stroke.

Genetic Modifiers at the Crossroads of Personalised Medicine for Haemoglobinopathies

Haemoglobinopathies are common monogenic disorders with diverse clinical manifestations, partly attributed to the influence of modifier genes. Recent years have seen enormous growth in the amount of genetic data, instigating the need for ranking methods to identify candidate genes with strong modifying effects. Here, we present the first evidence-based gene ranking metric (IthaScore) for haemoglobinopathy-specific phenotypes by utilising curated data in the IthaGenes database. IthaScore successfully reflects current knowledge for well-established disease modifiers, while it can be dynamically updated with emerging evidence. Protein-protein interaction (PPI) network analysis and functional enrichment analysis were employed to identify new potential disease modifiers and to evaluate the biological profiles of selected phenotypes. The most relevant gene ontology (GO) and pathway gene annotations for (a) haemoglobin (Hb) F levels/Hb F response to hydroxyurea included urea cycle, arginine metabolism and vascular endothelial growth factor receptor (VEGFR) signalling, (b) response to iron chelators included xenobiotic metabolism and glucuronidation, and (c) stroke included cytokine signalling and inflammatory reactions. Our findings demonstrate the capacity of IthaGenes, together with dynamic gene ranking, to expand knowledge on the genetic and molecular basis of phenotypic variation in haemoglobinopathies and to identify additional candidate genes to potentially inform and improve diagnosis, prognosis and therapeutic management.

Fracture Healing and the Underexposed Role of Extracellular Vesicle-Based Cross Talk

The process of fracture healing is complex and requires an interaction of multiple organ systems. Cell-cell communication is known to be very important during this process. Extracellular vesicles (EVs) are small membranous vesicles generated from a variety of cells. Proteins, RNAs, small molecules, and mitochondria DNA were found to be transported among cells through EVs. EV-based cross talk represents a substantial cell-cell communication pattern that can both interact with cells through molecular surfaces and transfer molecules to cells. These interactions can assist in the synchronization of cellular functions among cells of the same kind, and coordinate the functions of different types of cells. After activation, platelets, neutrophils, macrophages, osteoblasts, osteoclasts, and mesenchymal stem cell (') all secrete EVs, promoting the fracture healing process. Moreover, some studies have found evidence that EVs may be used for diagnosis and treatment of delayed fracture healing, and may be significantly involved in the pathophysiology of fracture healing disturbances. In this review, we summarize recent findings on EVs released by fracture healing-related cells, and EV-mediated communications during fracture healing. We also highlight the potential applications of EVs in fracture healing. Lastly, the prospect of EVs for research and clinical use is discussed.

Comparison of plasma PARK7 and NDKA diagnostic value in acute stroke

AIM

In this prospective case-control study we aimed to compare diagnostic value of plasma PARK7 and NDKA in early diagnosis of acute stroke and evaluate the validated diagnostic values of PARK7 and NDKA in an independent patient cohort. We then assessed the quantitative relationship between the release of these markers: stroke severity and time. Blood samples were drawn upon hospital admission and 14 days later. PARK7 and NDKA concentrations were measured using an ELISA.

RESULTS

The expression of PARK7 (area under the curve [AUC] = 0.897) in acute stroke patients was more significant than in controls, relative to the NDKA expression (AUC = 0.462); p < 0.05. Their expressions were not related to the clinical characteristics of both groups; p > 0.05.

CONCLUSION

Even though both markers cannot differentiate stroke etiologies (ischemic or hemorrhagic), plasma PARK7 has better diagnostic value than NDKA for early diagnosis of stroke. 72 plasma samples obtained from acute stroke patients and 78 plasma samples collected from non-stroke patients were analyzed in this study.

Gut Microbiota and Ischemic Stroke: The Role of Trimethylamine N-Oxide

Trimethylamine N-oxide (TMAO) is produced when trimethylamine, a waste product of gut microbes, is converted via hepatic flavin monooxygenases. As TMAO is a potential causative factor in various cardiovascular diseases (CVDs) considerable research interest has arisen on its use as a biomarker. Higher TMAO levels are associated with future risk of both incident CVD in the general population and established CVD, including stroke. The addition of TMAO into models with traditional risk factors significantly improved the prediction of future CVD risk. TMAO promotes atherosclerosis and is associated with platelet hyperreactivity and inflammation, which are in turn associated with the development of stroke and its secondary consequences. Additionally, TMAO may play a key mediator role in the relationship between the diet, gut microbiota, and CVD development. Compelling evidence suggesting that TMAO is both a risk factor and prognostic marker of stroke and CVD. Potential therapeutic strategy of diet and drugs in reducing TMAO levels have emerged. Thus, TMAO is a novel biomarker and target in stroke and CVD prevention.

Circulating microparticles as biomarkers of stroke: A focus on the value of endothelial- and platelet-derived microparticles

Stroke is one of the leading causes of mortality and disability worldwide. Numerous pathophysiological mechanisms involving blood vessels, coagulation and inflammation contribute to the vascular occlusion. Perturbations in these pathways can be detected by numerous methods including changes in endoplasmic membrane remodeling and rearrangement leading to the shedding of microparticles (MPs) from various cellular origins in the blood. MPs are small membrane-derived vesicles that are shed from nearly all cells in the body in resting state or upon stimulation. MPs act as biological messengers to transfer information to adjacent and distant cells thus regulating various biological processes. MPs may be important biomarkers and tools for the identification of the risk and diagnosis of cerebrovascular diseases. Endothelial activation and dysfunction and altered thrombotic responses are two of the main features predisposing to stroke. Endothelial MPs (EMPs) have been recognized as both biomarkers and effectors of endothelial cell activation and injury while platelet-derived MPs (PMPs) carry a strong procoagulant potential and are activated in thrombotic states. Therefore, we reviewed here the role of EMPs and PMPs as biomarkers of stroke. Most studies reported high circulating levels of EMPs and PMPs in addition to other cell origins in stroke patients and have been linked to stroke severity, the size of infarction, and prognosis. The identification and quantification of EMPs and PMPs may thus be useful for the diagnosis and management of stroke.

Amino Acid Biosignature in Plasma among Ischemic Stroke Subtypes

Ischemic stroke is a neurovascular disorder caused by reduced or blockage of blood flow to the brain, which may permanently affect motor and cognitive abilities. The diagnostic of stroke is performed using imaging technologies, clinical evaluation, and neuropsychological protocols, but no blood test is available yet. In this work, we analyzed amino acid concentrations in blood plasma from poststroke patients in order to identify differences that could characterize the stroke etiology. Plasma concentrations of sixteen amino acids from patients with chronic ischemic stroke (n = 73) and the control group (n = 16) were determined using gas chromatography coupled to mass spectrometry (GC-MS). The concentration data was processed by Partial Least Squares-Discriminant Analysis (PLS-DA) to classify patients with stroke and control. The amino acid analysis generated a first model able to discriminate ischemic stroke patients from control group. Proline was the most important amino acid for classification of the stroke samples in PLS-DA, followed by lysine, phenylalanine, leucine, and glycine, and while higher levels of methionine and alanine were mostly related to the control samples. The second model was able to discriminate the stroke subtypes like atherothrombotic etiology from cardioembolic and lacunar etiologies, with lysine, leucine, and cysteine plasmatic concentrations being the most important metabolites. Our results suggest an amino acid biosignature for patients with chronic stroke in plasma samples, which can be helpful in diagnosis, prognosis, and therapeutics of these patients.

Serum-mediated Activation of Bone Marrow-derived Mesenchymal Stem Cells in Ischemic Stroke Patients: A Novel Preconditioning Method

Stroke induces complex and dynamic, local and systemic changes including inflammatory reactions, immune responses, and repair and recovery processes. Mesenchymal stem cells (MSCs) have been shown to enhance neurological recovery after stroke. We hypothesized that serum factors play a critical role in the activation of bone marrow (BM) MSCs after stroke such as by increasing proliferation, paracrine effects, and rejuvenation. Human MSCs (hMSCs) were grown in fetal bovine serum (FBS), normal healthy control serum (NS), or stroke patient serum (SS). MSCs cultured in growth medium with 10% SS or NS exhibited higher proliferation indices than those cultured with FBS (P < 0.01). FBS-, NS-, and SS-hMSCs showed differences in the expression of trophic factors; vascular endothelial growth factor, glial cell–derived neurotrophic factor, and fibroblast growth factor were densely expressed in samples cultured with SS (P < 0.01). In addition, SS-MSCs revealed different cell cycle– or aging-associated messenger RNA expression in a later passage, and β-galactosidase staining showed the senescence of MSCs observed during culture expansion was lower in MSCs cultured with SS than those cultured with NS or FBS (P < 0.01). Several proteins related to the activity of receptors, growth factors, and cytokines were more prevalent in the serum of stroke patients than in that of normal subjects. Neurogenesis and angiogenesis were markedly increased in rats that had received SS-MSCs (P < 0.05), and these rats showed significant behavioral improvements (P < 0.01). Our results indicate that stroke induces a process of recovery via the activation of MSCs. Culture methods for MSCs using SS obtained during the acute phase of a stroke could constitute a novel MSC activation method that is feasible and efficient for the neurorestoration of stroke.

Role of PARK7 and NDKA in stroke management: a review of PARK7 and NDKA as stroke biomarkers

AIM

Biomarkers are molecules measured in plasma, serum or other body fluids to characterize a disease. PARK7 and NDKA roles in the management of stroke are still on study. Therefore, their potentials need to be developed in totality. The aim of this review is to demonstrate that PARK7 and NDKA could present more clinical important information as biomarkers for management of stroke disease. Main contents: Four main aspects of PARK7 and NDKA are exploited in this review. First, their diagnostic value is discussed in order to demonstrate their possible role as stroke diagnosis markers. Second, this article will exploit the correlation of both markers with time, by showing their dynamic changes in serum and plasma. Third, it describes the observed relationship of their levels with NIH Stroke Scale. The last aspect visits the possibility of their implementation in stroke therapy.

CONCLUSION

This article explores recent findings and proposes the potential roles that PARK7 and NDKA play in the management of acute stroke disease.

Risk Factors, Biomarkers, Etiology, Outcome and Prognosis of Ischemic Stroke in Cancer Patients

Introduction: Cerebrovascular disease is the second most common complication in individuals with tumours. The aim of this study was to investigate risk factors, biomarkers, etiology and prognosis of ischemic stroke in cancer patients (ISCPs). Methods: The medical records of 619 consecutive patients who were admitted with acute ischemic stroke from January 2012 to November 2014 were retrospectively evaluated. The patients were divided into two groups (group 1, patients with an active cancer prior to the onset of ischemic stroke; group 2, patients without an active cancer history). The demographic data, risk factors, NIHSS scores, thrombocyte count, D-dimer, fibrinogen and C reactive protein (CRP) level at admission, modified Rankin Scale (mRS) scores in the follow-up period and location of lesions on DWI were recorded. The Mann-Whitney U test, chi-squared test and logistic regression was used for analyzing data, p<0.05 being considered statistically significant. Results: A total of 46 (7.4%) ISCPs were included. Hyperlipidemia was significantly lower in the ISCP group (p=0.001). Elevated thrombocyte counts, D-dimer, fibrinogen and CRP levels at admission, acute multiple ischemic lesions, other causes, mortality in hospital and worse outcome were significantly related to ISCP (p<0.05). On logistic regression analysis, follow up mRS>3, acute multiple ischemic lesions located in more than one vascular territory (AMIMCT) and other causes were significantly associated with ISCP (p<0.001). Conclusion: In our study, other causes, AMIMCT and mRS>3 were more common in the ISCP group. We consider that CCS could be more suitable for detecting other causes than TOAST. Biomarkers could be important in the ISCP group.

Identification of potential diagnostic biomarkers of cerebral infarction using gas chromatography-mass spectrometry and chemometrics

Cerebral infarction (CI) is one of the most common cerebrovascular diseases and remains a major health problem worldwide. In this study, we evaluated the potential diagnostic biomarkers and important relevant metabolic pathways associated with CI. Metabolomics based on gas chromatography-mass spectrometry coupled with the multivariate pattern recognition technique were used to characterize the potential serum metabolic profiles of CI. Forty healthy controls and thirty-three cerebral infarction patients were recruited for the nontargeted global metabolites' study and subsequent targeted fatty acid analysis. Overall, thirty-four endogenous metabolites were found in serum from the untargeted global study, four of which were detected to be significantly different between the CI group and healthy controls, including l-lysine, octadecanoic acid (fatty acid), l-tyrosine and lactic acid. Additionally, fourteen free fatty acids were identified by the subsequent targeted fatty acid analysis, and seven of them were detected to be significantly different between the CI group and healthy controls, which were mainly associated with arachidonic acid metabolism and fatty acid metabolism. Our results suggest several potential diagnostic biomarkers, and serum metabolism research is demonstrated as a powerful tool to explore the pathogenesis of CI.

Cerebral infarction (CI) is one of the most common cerebrovascular diseases and remains a major health problem worldwide.

Nanoparticle-Based Therapeutics for Brain Injury

Brain injuries affect a large patient population with major physical and emotional suffering for patients and their relatives; at a significant cost to the society. Effective diagnostic and therapeutic options available for brain injuries are limited by the complex brain injury pathology involving blood-brain barrier (BBB). Brain injuries, including ischemic stroke and brain trauma, initiate BBB opening for a short period of time, which is followed by a second reopening for an extended time. The leaky BBB and/or the alterations in the receptor expression on BBB may provide opportunities for therapeutic delivery via nanoparticles (NPs). The approaches for therapeutic interventions via NP delivery are aimed at salvaging the pericontusional/penumbra area for possible neuroprotection and neurovascular unit preservation. The focus of this progress report is to provide a survey of NP strategies employed in cerebral ischemia and brain trauma and finally provide insights for improved NP-based diagnostic/treatment approaches.

Prospective of ischemic stroke biomarkers

Methods currently used in brain vascular disorder diagnostics are neither fast enough nor clear-out; thus, there exists a necessity of finding new types of testing which could enlarge and complete the actual panel of diagnostics or be an alternative to current methods. The discovery of sensitive and specific biomarkers of ischemic brain stroke will improve the effects of treatment and will help to assess the progress or complications of the disease. The relevant diagnosis of ischemic stroke (IS) within the first 4.5 hours after the initial symptoms allows for the initiation of treatment with recombinant tissue plasminogen activators which limits the magnitude of negative changes in the brain and which enhance the final effectiveness of therapy. The potential biomarkers which are under investigation are substances involved in the processes of coagulation and fibrinolysis, and are of molecules released from damaged vascular endothelial cells and from nerves and cardiac tissue. The analyzed substances are typical of oxidative stress, apoptosis, excitotoxicity and damage of the blood brain barrier.

Blood protein biomarkers as diagnostic tool for ischemic stroke: a systematic review

AIM

This systematic review provides a summary of the blood protein biomarkers that have been studied for the diagnosis of acute ischemic stroke.

MATERIALS & METHODS

An extensive MEDLINE (using PubMed) and Web of Knowledge search was performed. From the 354 articles found, 42 were eligible for further analysis and 25 protein biomarkers were examined.

RESULTS

Though many candidate blood-based protein biomarkers were examined, only two could significantly differentiate ischemic stroke patients from healthy controls, stroke mimics and hemorrhagic stroke patients.

CONCLUSION

The blood protein biomarkers, brain natriuretic peptide (BNP) and S100B, were promising biomarkers in diagnosing ischemic stroke. They could be used in cases of diagnostic uncertainty and/or when less experienced healthcare personnel are involved.

Caveolin-1, Ring finger protein 213, and endothelial function in Moyamoya disease

BACKGROUND

Moyamoya disease is a unique cerebrovascular occlusive disease of unknown etiology. Ring finger protein 213 (RNF213) was identified as a susceptibility gene for Moyamoya disease in East Asian countries. However, the pathogenesis of Moyamoya disease remains unclear.

METHODS

We prospectively analyzed clinical data for 139 patients with Moyamoya disease (108 bilateral Moyamoya disease, 31 unilateral Moyamoya disease), 61 patients with intracranial atherosclerotic stroke, and 68 healthy subjects. We compared the genetic (RNF213 variant) and protein biomarkers for caveolae (caveolin-1), angiogenesis (vascular endothelial growth factor (VEGF) and receptor (VEGFR2), and antagonizing cytokine (endostatin)) and endothelial dysfunction (asymmetric dimethylarginine (ADMA), and nitric oxide and its metabolites (nitrite and nitrate)) between patients with Moyamoya disease and intracranial atherosclerotic stroke. We then performed path analysis to evaluate whether a certain protein biomarker mediates the association between genes and Moyamoya disease.

RESULTS

Caveolin-1 level was decreased in patients with Moyamoya disease and markedly decreased in RNF213 variant carriers. Circulating factors such as VEGF and VEGFR2 did not differ among the groups. Markers for endothelial dysfunction were significantly higher in patients with intracranial atherosclerotic stroke but normal in those with Moyamoya disease. Path analysis showed that the presence of the RNF213 variant was associated with caveolin-1 levels that could lead to Moyamoya disease. The level of combined marker of Moyamoya disease (caveolin-1) and intracranial atherosclerotic stroke (ADMA, an endothelial dysfunction marker) predicted Moyamoya disease with good sensitivity and specificity.

CONCLUSION

Our results suggest that Moyamoya disease is a caveolae disorder but is not related to endothelial dysfunction or dysregulation of circulating cytokines.

Extracellular Vesicles in Molecular Diagnostics: An Overview with a Focus on CNS Diseases

All known cells continuously release nanoscale lipid membrane-enclosed packets. These packets, termed extracellular vesicles (EVs), bear the signature of their cells of origin. These vesicles can be detected in just about every type of biofluid tested, including blood, urine, and cerebrospinal fluid. The majority comes from normal cells, but disease cells also release them. There is a great interest in collecting and analyzing EVs in biofluids as diagnostics for a wide spectrum of central nervous system diseases. Here, we will review the state of central nervous system EV research in terms of molecular diagnostics and biomarkers.

Rapid and Sensitive Differentiating Ischemic and Hemorrhagic Strokes by Dried Blood Spot Based Direct Injection Mass Spectrometry Metabolomics Analysis

Cerebral infarction (CI) and intracerebral hemorrhage are lethal cerebrovascular diseases, sometimes sharing similar clinical manifestations but with distinct therapeutic strategies. Delayed treatment usually resulted in poor prognosis. A timely diagnosis report is highly warranted especially in emergency. One hundred twenty-nine CI patients, 73 intracerebral hemorrhage (ICH) patients, and 98 controls were enrolled in this study. A direct injection mass spectrometry metabolomics approach was adopted using dried blood spot samples. This targeted metabolomics analysis focused on absolute quantitation of 23 amino acids, 26 carnitine/carnitine esters, and 22 calculated ratios parameters. Compared to the normal control group, CI and ICH showed distinct metabolite changes, respectively. For stroke differentiation, Tyr, C5-OH/C0, Cit, Asn, Pro, Val, Arg/Orn, Leu, and Val/Phe were elevated in the CI group. On the contrary, C5:1, Phe/Tyr, (C0 + C2 + C3 + C16 + C18:1)/Cit, and Met/Leu were of lower levels in the CI group. Using regression model based on some of the above-mentioned parameters, 79.07% of stroke patients from a new set could be definitely confirmed. This study proved the targeted metabolomics analysis was a promising tool for rapid and timely stroke differentiation.

A Polymorphism in RNF213 Is a Susceptibility Gene for Intracranial Atherosclerosis

Background

Both intracranial atherosclerotic stenosis (ICAS) and moyamoya disease (MMD) are prevalent in Asians. We hypothesized that the Ring Finger protein 213 gene polymorphism (RNF213), a susceptibility locus for MMD in East Asians, is also a susceptibility gene for ICAS in patients whose diagnosis had been confirmed by conventional angiography (absence of basal collaterals) and high-resolution MRI (HR-MRI, presence of plaque).

Methods

We analyzed 532 consecutive patients with ischemic events in the middle cerebral artery (MCA) distribution and relevant stenotic lesion on the distal internal carotid artery or proximal MCA, but no demonstrable carotid or cardiac embolism sources. Additional angiography was performed on 370 (69.5%) patients and HR-MRI on 283 (53.2%) patients.

Results

Based on angiographic and HR-MRI findings, 234 patients were diagnosed with ICAS and 288 with MMD. The RNF213 variant was observed in 50 (21.4%) ICAS patients and in 119 (69.1%) MMD patients. The variant was observed in 25.2% of patients with HR-MRI-confirmed ICAS. Similarly, 15.8% of ICAS patients in whom MMD was excluded by angiography had this variant. Among the ICAS patients, RNF213 variant carriers were younger and more likely to have a family history of MMD than non-carriers were. Multivariate testing showed that only the age of ICAS onset was independently associated with the RNF213 variant (odds ratio, 0.97; 95% CI, 0.944–0.99).

Conclusions

RNF213 is a susceptibility gene not only for MMD but also for ICAS in East Asians. Further studies are needed on RNF213 variants in ICAS patients outside East Asian populations.

Genetic susceptibility to cerebrovascular disease

PURPOSE OF REVIEW

Cerebrovascular disease (CeVD) remains a major cause of death and a leading cause of disability worldwide. CeVD is a complex and multifactorial disease caused by the interaction of vascular risk factors, environment, and genetic factors. In the present article, we discussed genetic susceptibility to CeVD, with particular emphasis on genetic studies of the associations between lipid traits and CeVD.

RECENT FINDINGS

Several animal and clinical studies clearly defined genetic predisposition to atherosclerosis and CeVD, and particularly to ischemic stroke. Recent evidence has shown that traditional vascular risk factors explain only a small proportion of variance in atherosclerosis, suggesting that additional nontraditional factors and novel genetic determinants impact CeVD. With the help of genome-wide technology, novel genetic variants have been implicated in CeVD and lipid metabolism such as those in protein convertase subtilisin/kexin type 9 (PCSK9) gene in stroke and familial hypercholesterolemia. These studies are important as they contribute to our understanding of the genetic mechanisms underlying CeVD and to developing more effective CeVD prevention strategies.

SUMMARY

CeVD is a complex and multifactorial disease and genetics likely plays an important role in its pathogenesis. The gene-gene and gene-environment interactions of genes involved in biology of vascular disease, including the lipid metabolism are important factors for individual susceptibility to CeVD. Accounting for individual variation in genes, environment and lifestyle will bring us closer to precision medicine, which is an emerging and recently introduced new approach for disease treatment and prevention in clinical practice.

Blood biomarkers in the early stage of cerebral ischemia

In ischemic stroke patients, blood-based biomarkers may be applied for the diagnosis of ischemic origin and subtype, prediction of outcomes and targeted treatment in selected patients. Knowledge of the pathophysiology of cerebral ischemia has led to the evaluation of proteins, neurotransmitters, nucleic acids and lipids as potential biomarkers. The present report focuses on the role of blood-based biomarkers in the early stage of ischemic stroke-within 72h of its onset-as gleaned from studies published in English in such patients. Despite growing interest in their potential role in clinical practice, the application of biomarkers for the management of cerebral ischemia is not currently recommended by guidelines. However, there are some promising clinical biomarkers, as well as the N-methyl-d-aspartate (NMDA) peptide and NMDA-receptor (R) autoantibodies that appear to identify the ischemic nature of stroke, and the glial fibrillary acidic protein (GFAP) that might be able to discriminate between acute ischemic and hemorrhagic strokes. Moreover, genomics and proteomics allow the characterization of differences in gene expression, and protein and metabolite production, in ischemic stroke patients compared with controls and, thus, may help to identify novel markers with sufficient sensitivity and specificity. Additional studies to validate promising biomarkers and to identify novel biomarkers are needed.

Brain microangiopathy and macroangiopathy share common risk factors and biomarkers

AIMS

Besides carotid or cardiac embolism, stroke can occur via microangiopathy (small arterial disease [SAD]) and macroangiopathy (intracranial atherosclerotic stroke [ICAS]) of the intracranial vasculature. There have been efforts to identify risk factors specific to microangiopathy and macroangiopathy, including vascular risk factors, and protein and genetic biomarkers. We hypothesized that despite the anatomic and pathophysiological differences between microvessels and macrovessels, microangiopathy and macroangiopathy share common risk factors during disease progression.

METHODS

Among 714 patients with acute infarctions within middle cerebral artery territory, 126 with SAD and 116 with ICAS were included in this study. Subclinical microangiopathy (degree of leukoaraiosis) and macroangiopathy (number of tandem stenosis) was graded in each patient. Inflammatory biomarkers (C-reactive protein, E-selectin, and LpPLA2), endothelial dysfunction (asymmetric dimethylarginine, urinary albumin-to-creatinine ratio, endostatin, and homocysteine), atherogenesis (lipoprotein(a), adiponectin, and resistin), and renal function (creatinine clearance and estimated glomerular filtration rate) were assessed.

RESULTS

Compared with the patients with isolated SAD, those with isolated ICAS were younger, were current smokers, and showed higher apoB levels (p < 0.05 in all cases). However, with the progression of subclinical microangiopathy, asymptomatic macroangiopathy worsened and vice versa. No significant differences in risk factors were observed between advanced SAD and ICAS. Decreased renal function was independently associated with progression of microangiopathy and macroangiopathy. Markers of endothelial dysfunction, but not the other markers, were significantly related to creatinine clearance level.

CONCLUSIONS

Mild to moderate loss of renal function is strongly associated with both intracranial microangiopathy and macroangiopathy. Endothelial dysfunction may be associated with this relationship.

Effects of Mesenchymal Stem Cell Treatment on the Expression of Matrix Metalloproteinases and Angiogenesis during Ischemic Stroke Recovery

Background

The efficacy of mesenchymal stem cell (MSC) transplantation in ischemic stroke might depend on the timing of administration. We investigated the optimal time point of MSC transplantation. After MSC treatment, we also investigated the expression of matrix metalloproteinases (MMPs), which play a role in vascular and tissue remodeling.

Methods

Human bone marrow-derived MSCs (2 × 10⁶, passage 5) were administrated intravenously after permanent middle cerebral artery occlusion (MCAO) was induced in male Sprague-Dawley rats. First, we determined the time point of MSC transplantation that led to maximal neurological recovery at 1 h, 1 day, and 3 days after MCAO. Next, we measured activity of MMP-2 and MMP-9, neurological recovery, infarction volume, and vascular density after transplanting MSCs at the time that led to maximal neurological recovery.

Results

Among the MSC-transplanted rats, those of the MSC 1-hour group showed maximal recovery in the rotarod test (P = 0.023) and the Longa score (P = 0.018). MMP-2 activity at 1 day after MCAO in the MSC 1-hour group was significantly higher than that in the control group (P = 0.002), but MMP-9 activity was not distinct. The MSC 1-hour group also showed smaller infarction volume and higher vascular density than did the control group.

Conclusions

In a permanent model of rodent MCAO, very early transplantation of human MSCs (1 h after MCAO) produced greater neurological recovery and decreased infraction volume. The elevation of MMP-2 activity and the increase in vascular density after MSC treatment suggest that MSCs might help promote angiogenesis and lead to neurological improvement during the recovery phase after ischemic stroke.

Serum Phenylalanine, Tyrosine, and their Ratio in Acute Ischemic Stroke: on the Trail of a Biomarker?

Fast diagnosis and appropriate treatment are of utmost importance to improving the outcome in patients with acute ischemic stroke (AIS). A rapid and sensitive blood test for ischemic stroke is required. The aim of this study was to examine the usefulness of phenylalanine (PHE) and tyrosine (TYR) as diagnostic biomarkers in AIS. Serum levels of PHE and TYR, measured using HPLC, and their ratio (PHE/TYR) were compared between 45 patients with AIS and 40 healthy control subjects. The relationship between PHE/TYR and the serum levels of several cytokines were also examined. PHE/TYR was significantly higher in AIS patients than in healthy controls (1.75 vs 1.24, p < 0.001). A receiver operating characteristic (ROC) curve analysis of PHE/TYR in AIS patients relative to healthy controls revealed promising sensitivity and specificity, which at an optimal cutoff of 1.45 were 76 and 85 %, respectively. PHE/TYR was positively correlated with interleukin (IL)-1β (r = 0.37, p = 0.011) and IL-6 (r = 0.33, p = 0.025). This study shows that PHE/TYR is highly elevated in the acute phase of AIS, and that this elevation is coupled to the inflammatory response. The ROC analysis documents the possible value of PHE/TYR as a biomarker for AIS and demonstrates its clinical potential as a blood-based test for AIS.

B-Type Natriuretic Peptides Help in Cardioembolic Stroke Diagnosis

Background and Purpose—

Determining the underlying cause of stroke is important to optimize secondary prevention treatment. Increased blood levels of natriuretic peptides (B-type natriuretic peptide/N-terminal pro-BNP [BNP/NT-proBNP]) have been repeatedly associated with cardioembolic stroke. Here, we evaluate their clinical value as pathogenic biomarkers for stroke through a literature systematic review and individual participants’ data meta-analysis.

Methods—

We searched publications in PubMed database until November 2013 that compared BNP and NT-proBNP circulating levels among stroke causes. Standardized individual participants’ data were collected to estimate predictive values of BNP/NT-proBNP for cardioembolic stroke. Dichotomized BNP/NT-proBNP levels were included in logistic regression models together with clinical variables to assess the sensitivity and specificity to identify cardioembolic strokes and the additional value of biomarkers using area under the curve and integrated discrimination improvement index.

Results—

From 23 selected articles, we collected information of 2834 patients with a defined cause. BNP/NT-proBNP levels were significantly elevated in cardioembolic stroke until 72 hours from symptoms onset. Predictive models showed a sensitivity >90% and specificity >80% when BNP/NT-proBNP were added considering the lowest and the highest quartile, respectively. Both peptides also increased significantly the area under the curve and integrated discrimination improvement index compared with clinical models. Sensitivity, specificity, and precision of the models were validated in 197 patients with initially undetermined stroke with final pathogenic diagnosis after ancillary follow-up.

Conclusions—

Natriuretic peptides are strongly increased in cardioembolic strokes. Future multicentre prospective studies comparing BNP and NT-proBNP might aid in finding the optimal biomarker, the best time point, and the optimal cutoff points for cardioembolic stroke identification.

Prognostic value of copeptin in patients with acute stroke

CONTEXT

There is a need to improve stroke care through the prompt identification of stroke patients at increased risk of an adverse outcome.

OBJECTIVE

To evaluate the prognostic value of copeptin in patients with stroke.

METHODS

We systematically searched PubMed and Embase for relevant studies. Poor outcome and mortality were analyzed.

RESULTS

Twelve studies, containing 2682 patients, were included. Pooled analysis showed that copeptin is an independent prognostic marker of poor outcome after acute stroke and there is a borderline effect of copeptin in predicting mortality after acute stroke.

CONCLUSIONS

Copeptin is an independent predictor of poor outcome and mortality for patients with acute stroke.

Risk factors and biomarkers of ischemic stroke in cancer patients

BACKGROUND AND PURPOSE

Stroke is common among cancer patients. However, risk factors and biomarkers of stroke in cancer patients are not well established. This study aimed to investigate risk factors and biomarkers as well as etiology of ischemic stroke in cancer patients.

METHODS

A retrospective review was conducted in cancer patients with ischemic stroke who were admitted to a general hospital in Busan, Korea, between January 2003 and December 2012. The risk factors and biomarkers for stroke and stroke subtypes in cancer patients were compared with age- and sex-matched noncancer patients with ischemic stroke who were admitted to the same hospital during the same period.

RESULTS

One hundred fifty-six cancer patients with ischemic stroke were identified. Cancer patients with ischemic stroke were found to have a significantly lower proportion of hypertension, atrial fibrillation, hyperlipidemia, and ischemic heart disease than noncancer patients with ischemic stroke. However, stroke biomarkers, such as erythrocyte sedimentation rate and high-sensitivity C-reactive protein, fibrinogen, pro-brain natriuretic peptide, and D-dimer levels, were significantly increased in cancer patients with ischemic stroke than in noncancer patients. Large-artery atherosclerosis and stroke of undetermined cause were more common in cancer patients with ischemic stroke than in noncancer patients with ischemic stroke.

CONCLUSIONS

Cancer patients with ischemic stroke showed different risk factors, stroke biomarkers, and stroke etiology compared with noncancer patients with ischemic stroke.

The prognostic values of leukocyte Rho kinase activity in acute ischemic stroke

Objective. It has been reported that leukocyte ROCK activity is elevated in patients after ischemic stroke, but it is unclear whether leukocyte ROCK activity is associated with clinical outcomes following acute stroke events. The objective of this study is to investigate if leukocyte ROCK activity can predict the outcomes in patients with acute ischemic stroke. Materials and Methods. We enrolled 110 patients of acute ischemic stroke and measured the leukocyte ROCK activity and plasma level of inflammatory cytokines to correlate the clinical outcomes of these patients. Results. The leukocyte ROCK activity at 48 hours after admission in acute ischemic stroke patients was higher as compared to a risk-matched population. The leukocyte ROCK activity significantly correlated with National Institute of Health Stroke Scale (NIHSS) difference between admission and 90 days after stroke event. Kaplan-Meier survival estimates showed lower stroke-free survival during follow-up period in patients with high leukocyte ROCK activity or plasma hsCRP level. Leukocyte ROCK activity independently predicted the recurrent stroke in patients with atherosclerotic stroke. Conclusions. This study shows elevated leukocyte ROCK activity in patients with ischemic stroke as compared to risk-matched subjects and is an independent predictor for recurrent stroke.