MMP9 variation after thrombolysis is associated with hemorrhagic transformation of lesion and death

Jingfang granules protects against intracerebral hemorrhage by inhibiting neuroinflammation and protecting blood-brain barrier damage

Intracerebral hemorrhage (ICH) can induce intensive oxidative stress, neuroinflammation, and brain cell apoptosis. However, conventional methods for ICH treatment have many disadvantages. There is an urgent need for alternative, effective therapies with minimal side effects. Pharmacodynamics experiment, molecular docking, network pharmacology, and metabolomics were adopted to investigate the treatment and its mechanism of Jingfang Granules (JFG) in ICH. In this study, we investigated the therapeutic effects of JFG on ICH using behavioral, brain water content and Magnetic resonance imaging experiments. However, the key active component and targets of JFG remain unknown. Here we verified that JFG was beneficial to improve brain injury after ICH. A network pharmacology analysis revealed that the anti-inflammatory effect of JFG is predominantly mediated by its activation of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway through Luteolin, (+)-Anomalin and Phaseol and their targeting of AKT1, tumor necrosis factorα (TNF-α), and interleukin-1β (IL-1β). Molecular docking analyses revealed an average affinity of -8.633 kcal/mol, indicating a binding strength of less than -5 kcal/mol. Metabolomic analysis showed that JFG exerted its therapeutic effect on ICH by regulating metabolic pathways, such as the metabolism of taurine and hypotaurine, biosynthesis of valine, leucine, and isoleucine. In conclusion, we demonstrated that JFG attenuated neuroinflammation and BBB injury subsequent to ICH by activating the PI3K/Akt signaling pathway.

LOX-1 and MMP-9 Inhibition Attenuates the Detrimental Effects of Delayed rt-PA Therapy and Improves Outcomes After Acute Ischemic Stroke

BACKGROUND

Acute ischemic stroke triggers endothelial activation that disrupts vascular integrity and increases hemorrhagic transformation leading to worsened stroke outcomes. rt-PA (recombinant tissue-type plasminogen activator) is an effective treatment; however, its use is limited due to a restricted time window and hemorrhagic transformation risk, which in part may involve activation of MMPs (matrix metalloproteinases) mediated through LOX-1 (lectin-like oxLDL [oxidized low-density lipoprotein] receptor 1). This study's overall aim was to evaluate the therapeutic potential of novel MMP-9 (matrix metalloproteinase 9) ± LOX-1 inhibitors in combination with rt-PA to improve stroke outcomes.

METHODS

A rat thromboembolic stroke model was utilized to investigate the impact of rt-PA delivered 4 hours poststroke onset as well as selective MMP-9 (JNJ0966) ±LOX-1 (BI-0115) inhibitors given before rt-PA administration. Infarct size, perfusion, and hemorrhagic transformation were evaluated by 9.4-T magnetic resonance imaging, vascular and parenchymal MMP-9 activity via zymography, and neurological function was assessed using sensorimotor function testing. Human brain microvascular endothelial cells were exposed to hypoxia plus glucose deprivation/reperfusion (hypoxia plus glucose deprivation 3 hours/R 24 hours) and treated with ±tPA and ±MMP-9 ±LOX-1 inhibitors. Barrier function was assessed via transendothelial electrical resistance, MMP-9 activity was determined with zymography, and LOX-1 and barrier gene expression/levels were measured using qRT-PCR (quantitative reverse transcription PCR) and Western blot.

RESULTS

Stroke and subsequent rt-PA treatment increased edema, hemorrhage, MMP-9 activity, LOX-1 expression, and worsened neurological outcomes. LOX-1 inhibition improved neurological function, reduced edema, and improved endothelial barrier integrity. Elevated MMP-9 activity correlated with increased edema, infarct volume, and decreased neurological function. MMP-9 inhibition reduced MMP-9 activity and LOX-1 expression. In human brain microvascular endothelial cells, LOX-1/MMP-9 inhibition differentially attenuated MMP-9 levels, inflammation, and activation following hypoxia plus glucose deprivation/R.

CONCLUSIONS

Our findings indicate that LOX-1 inhibition and ± MMP-9 inhibition attenuate negative aspects of ischemic stroke with rt-PA therapy, thus resulting in improved neurological function. While no synergistic effect was observed with simultaneous LOX-1 and MMP-9 inhibition, a distinct interaction is evident.

Assessing the predictive value of neutrophil percentage to albumin ratio for ICU admission in ischemic stroke patients

Background

Acute ischemic stroke (AIS) remains a substantial global health challenge, contributing to increased morbidity, disability, and mortality. This study aimed at investigating the predictive value of the neutrophil percentage to albumin ratio (NPAR) in determining intensive care unit (ICU) admission among AIS patients.

Methods

A retrospective observational study was conducted, involving AIS cases admitted to a tertiary hospital in Jordan between 2015 and 2020. Lab data were collected upon admission, and the primary outcome was ICU admission during hospitalization. Descriptive and inferential analyses were performed using SPSS version 29.

Results

In this study involving 364 AIS patients, a subset of 77 (21.2%) required admission to the ICU during their hospital stay, most frequently within the first week of admission. Univariable analysis revealed significantly higher NPAR levels in ICU-admitted ischemic stroke patients compared to those who were not admitted (23.3 vs. 15.7, p < 0.001), and multivariable regression models confirmed that higher NPAR (≥19.107) independently predicted ICU admission in ischemic stroke patients (adjusted odds ratio [aOR] = 4.85, 95% CI: 1.83-12.83). Additionally, lower GCS scores and higher neutrophil-to-lymphocyte ratio (NLR) were also associated with increased likelihood of ICU admission. In terms of predictive performance, NPAR showed the highest accuracy with an AUC of 0.885, sensitivity of 0.805, and specificity of 0.854, using a cutoff value of 19.107. NPAR exhibits an AUC of 0.058, significantly outperforming NLR (Z = 2.782, p = 0.005).

Conclusion

NPAR emerged as a robust independent predictor of ICU admission in ischemic stroke patients, surpassing the predictive performance of the NLR.

Advancing stroke therapy: A deep dive into early phase of ischemic stroke and recanalization

Ischemic stroke, accounting for the majority of stroke events, significantly contributes to global morbidity and mortality. Vascular recanalization therapies, namely intravenous thrombolysis and mechanical thrombectomy, have emerged as critical interventions, yet their success hinges on timely application and patient-specific factors. This review focuses on the early phase pathophysiological mechanisms of ischemic stroke and the nuances of recanalization. It highlights the dual role of neutrophils in tissue damage and repair, and the critical involvement of the blood-brain barrier (BBB) in stroke outcomes. Special emphasis is placed on ischemia-reperfusion injury, characterized by oxidative stress, inflammation, and endothelial dysfunction, which paradoxically exacerbates cerebral damage post-revascularization. The review also explores the potential of targeting molecular pathways involved in BBB integrity and inflammation to enhance the efficacy of recanalization therapies. By synthesizing current research, this paper aims to provide insights into optimizing treatment protocols and developing adjuvant neuroprotective strategies, thereby advancing stroke therapy and improving patient outcomes.

The Role of Extracellular Matrix and Inflammation in the Stratification of Bleeding and Thrombotic Risk of Atrial Fibrillation on Oral Anticoagulant Therapy: Insights from Strat-Af Study

In anticoagulated atrial fibrillation (AF) patients, the validity of models recommended for the stratification of the risk ratio between benefits and hemorrhage risk is limited. We hypothesize that both circulating and neuroimaging-based markers might improve the prediction of bleeding and thrombotic risk in anticoagulated AF patients. The Strat-AF study is an observational, prospective, single-center study enrolling 170 patients with AF; recruited patients are evaluated by means of a comprehensive protocol, with clinical, cerebral magnetic resonance imaging and circulating biomarkers assessment. The main outcome is the evaluation of cerebral microangiopathy related to the levels of circulating biomarkers of inflammation and extracellular matrix (ECM) remodeling. At multivariate logistic regression analysis adjusted for age, sex, CHA2DS2-VASc, HAS-BLED and type of anticoagulant, matrix metalloproteinases (MMP)-2 levels were significantly and positively associated with the presence of cerebral microbleeds (CMBs). A significant association between MMP-2, tissue inhibitor of metalloproteinases (TIMP)-1,-2,-4 levels and white matter hyperintensity was also found. Concerning the small vessel disease (SVD) score, MMP-2 and TIMP-1,-2 levels were associated with the presence of two and three or more signs of SVD, whereas TIMP-4 levels were associated with the presence of three signs of SVD with respect to patients with no instrumental signs of SVD. As regarding the presence of enlarged perivascular spaces (EPVS), a significant association was found for high levels of interleukin (IL)-8 and TIMP 1-2-3. These results demonstrate that patients with AF have evidence of impaired ECM degradation, which is an independent risk factor for thrombotic complications of AF patients on oral anticoagulant therapy. The incorporation of these markers in the prognostic schemes might improve their clinical capability in predicting stroke risk and thrombotic complications.

SGLT2 inhibitor dapagliflozin alleviates intramyocardial hemorrhage and adverse ventricular remodeling via suppressing hepcidin in myocardial ischemia-reperfusion injury

Intramyocardial hemorrhage (IMH), a reperfusion therapy-associated complication, is the extravasation of red blood cells caused by severe microvascular injury. IMH is an independent predictor of adverse ventricular remodeling (AVR) after acute myocardial infarction (AMI). Hepcidin, a major regulator of iron uptake and systemic distribution, is a key factor affecting AVR. However, the role of cardiac hepcidin in the development of IMH has not been completely elucidated. This study aimed to explore if sodium-dependent glucose co-transporter 2 inhibitor (SGLT2i) exerts therapeutic effects on IMH and AVR by suppressing hepcidin and to elucidate the underlying mechanisms. SGLT2i alleviated IMH and AVR in the ischemia-reperfusion injury (IRI) mouse model. Additionally, SGLT2i downregulated the cardiac levels of hepcidin in IRI mice, suppressed M1-type macrophage polarization, and promoted M2-type macrophage polarization. The effects of hepcidin knockdown on macrophage polarization were similar to those of SGLT2i in RAW264.7 cells. SGLT2i treatment or hepcidin knockdown inhibited the expression of MMP9, an inducer of IMH and AVR, in RAW264.7 cells. Regulation of macrophage polarization and reduction of MMP9 expression by SGLT2i and hepcidin knockdown is achieved through activation of pSTAT3. In conclusion, this study demonstrated that SGLT2i alleviated IMH and AVR by regulating macrophage polarization. The potential mechanism through which SGLT2i exerted its therapeutic effect seems to involve the downregulation of MMP9 via the hepcidin-STAT3 pathway.

Combined Therapeutics: Future Opportunities for Co-therapy with Thrombectomy

Stroke is an urgent public health issue with millions of patients worldwide living with its devastating effects. The advent of thrombolysis and endovascular thrombectomy has transformed the hyperacute care of these patients. However, a significant proportion of patients receiving these therapies still goes on to have unfavorable outcomes and many more remain ineligible for these therapies based on our current guidelines. The future of stroke care will depend on an expansion of the scope of thrombolysis and endovascular thrombectomy to patients outside traditional time windows, more distal occlusions, and large vessel occlusions with mild clinical deficits, for whom clinical trial results have not proven therapeutic efficacy. Novel cytoprotective therapies targeting the ischemic cascade and reperfusion injury therapy, in combination with our existing treatment modalities, should be explored to further improve outcomes for these patients with acute ischemic stroke. In this review, we will review the current status of thrombolysis and thrombectomy, suggest additional data that is needed to enhance these therapies, and discuss how cytoprotection might be combined with thrombectomy.

Leukocyte indicators and variations predict worse outcomes after intravenous thrombolysis in patients with acute ischemic stroke

Leukocytes are systematic inflammation indicators related to stroke prognosis and can exhibit large dynamic waves before and after recombinant tissue plasminogen activator (r-tPA) therapy. However, additional evidence is needed to determine the prognostic significance of various leukocytes including both static and dynamic data among patients who underwent r-tPA therapy. A total of 251 patients treated with r-tPA were included; their leukocyte data were collected at two time points, and patients were followed up for three months. Analysis revealed the following findings. (i) Patients with hemorrhagic transformation (HT) and unfavorable outcomes had a higher level of leukocytes after r-tPA therapy (leukocyte count (adjusted OR (aOR) 1.191 for HT and 1.184 for unfavorable outcomes), neutrophil count (aOR 1.215 and 1.214), neutrophil-to-lymphocyte ratio (NLR; aOR 1.084 and 1.091)) and larger dynamic leukocyte changes. (ii)Among all leukocytes, the NLR after r-tPA administration demonstrated the strongest correlation with HT and unfavorable outcomes. (iii) Patients with an NLR ≥ 3.322 had a 3.492-fold increased risk for HT, and those with an NLR ≥ 5.511 had a 3.024-fold increased risk for functional outcomes. Overall, this study shows that leukocytes, especially leukocyte count, neutrophil count and the NLR, are independently associated with HT and functional outcomes in stroke patients.

Polymorphisms of the Matrix Metalloproteinase Genes are Associated with Acute Ischemic Stroke in Chinese Han Population

Background and Purpose

Studies have shown that matrix metalloproteinase (MMP-2,3,9) plays an important role in the pathologic process of ischemic stroke (IS). The aim of this study was to investigate the relationship between C1306T, 1612-5A/6A, C-1562T polymorphisms of MMP-2,3,9 genes and IS in Chinese Han population.

Methods

The polymorphisms of MMP-2(C1306T), -3(1612-5A/6A), -9(C-1562T) gene were detected by PCR-RFLP and SNaPshot sequencing. Then, stratified analysis was used to study the relationship between IS subtypes and MMP-2,3,9 polymorphisms.

Results

For the MMP-2 gene C1306T polymorphism, TT genotype and T allele were significantly associated with a reduced risk of IS (P = 0.015, P = 0.003, respectively). T allele was significantly associated with a reduced risk of small artery occlusion (SAO) subtype compared with the control group (P = 0.012, OR = 0.550, 95% CI = 0.065-1.291). For the MMP-3 gene-1612 (5A/6A) polymorphism, 5A/5A genotype was significantly increased in the IS group (P = 0.011, OR = 0.370, 95% CI = 0.168-0.814), especially in the large-artery atherosclerosis (LAA) subtype (P = 0.001, OR = 2.345) as compared to the control group.

Conclusion

Our study suggested that the T allele of MMP-2 may be a protective factor of IS, especially in SAO subtype, while the 5A/5A gene of MMP-3 may increase the risk of IS, especially in LAA subtype in Chinese Han population.

Nuclear Magnetic Resonance-Based Metabolomics to Predict Early and Late Adverse Outcomes in Ischemic Stroke Treated with Intravenous Thrombolysis

Metabolic perturbations and inflammatory mediators play a fundamental role in both early and late adverse post-acute ischemic stroke outcomes. Using data from the observational MAGIC (MArker bioloGici nell'Ictus Cerebrale) study, we evaluated the effect of 130 serum metabolic features, using a nuclear magnetic spectroscopy approach, on the following outcomes: hemorrhagic transformation at 24 h after stroke, non-response to intravenous thrombolytic treatment with the recombinant tissue plasminogen activator (rt-PA), and the 3 month functional outcome. Blood circulating metabolites, lipoproteins, and inflammatory markers were assessed at the baseline and 24 h after rt-PA treatment. Adjusting for the major determinants for unfavorable outcomes (i.e., age, sex, time onset-to-treatment, etc.), we found that acetone and 3-hydroxybutyrate were associated with symptomatic hemorrhagic transformation and with non-response to rt-PA; while 24 h after rt-PA, levels of triglycerides high-density lipoprotein (HDL) and triglycerides low-density lipoprotein (LDL) were associated with 3 month mortality. Cholesterol and phospholipids levels, mainly related to smaller and denser very low-density lipoprotein (VLDL) and LDL subfractions were associated with 3 month poor functional outcomes. We also reported associations between baseline 24 h relative variation (Δ) in VLDL subfractions and ΔC-reactive protein, Δinterleukin-10 levels with hemorrhagic transformation. All observed metabolic changes reflect a general condition of energy failure, oxidative stress, and systemic inflammation that characterize the development of adverse outcomes.

Recent advances in drug delivery and targeting to the brain

Our body keeps separating the toxic chemicals in the blood from the brain. A significant number of drugs do not enter the central nervous system (CNS) due to the blood-brain barrier (BBB). Certain diseases, such as tumor growth and stroke, are known to increase the permeability of the BBB. However, the heterogeneity of this permeation makes it difficult and unpredictable to transport drugs to the brain. In recent years, research has been directed toward increasing drug penetration inside the brain, and nanomedicine has emerged as a promising approach. Active targeting requires one or more specific ligands on the surface of nanoparticles (NPs), which brain endothelial cells (ECs) recognize, allowing controlled drug delivery compared to conventional targeting strategies. This review highlights the mechanistic insights about different cell types contributing to the development and maintenance of the BBB and summarizes the recent advancement in brain-specific NPs for different pathological conditions. Furthermore, fundamental properties of brain-targeted NPs will be discussed, and the standard lesion features classified by neurological pathology are summarized.

Fluid biomarkers in stroke: From animal models to clinical care

Stroke is a leading cause of death and disability worldwide. Stroke prevention, early diagnosis, and efficient acute treatment are priorities to successfully impact stroke death and disability. Fluid biomarkers may improve stroke differential diagnostic, patient stratification for acute treatment, and post-stroke individualized rehabilitation. In the present work, we characterized the use of stroke animal models in fluid biomarker research through a systematic review of PubMed and Scopus databases, followed by a literature review on the translation to the human stroke care setting and future perspectives in the field. We found increasing numbers of publications but with limited translation to the clinic. Animal studies are very heterogeneous, do not account for several human features present in stroke, and, importantly, only a minority of such studies used human cohorts to validate biomarker findings. Clinical studies have found appealing candidates, both protein and circulating nucleic acids, to contribute to a more personalized stroke care pathway. Still, brain tissue complexity and the fact that different brain pathologies share lesion biomarkers make this task challenging due to biomarker low specificity. Moreover, the study design and lack of validation cohorts may have precluded a formal integration of biomarkers in different steps of stroke diagnosis and treatment. To overcome such issues, recent pivotal studies on biomarker dynamics in individual patients are providing added value to diagnosis and anticipating patients' early prognosis. Presently, the most consistent protein biomarkers for stroke diagnosis and short- and long-term prognosis are associated with tissue damage at neuronal (TAU), axonal (NFL), or astroglial (GFAP and S100β) levels. Most promising nucleic acids are microRNAs (miR), due to their stability in plasma and ease of access. Still, clinical validation and standardized quantitation place them a step behind compared protein as stroke biomarkers. Ultimately, the definition of clinically relevant biomarker panels and optimization of fast and sensitive biomarker measurements in the blood, together with their combination with clinical and neuroimaging data, will pave the way toward personalized stroke care.

Machine Learning-Based Model for Prediction of Hemorrhage Transformation in Acute Ischemic Stroke After Alteplase

Hemorrhage transformation (HT) is the most dreaded complication of intravenous thrombolysis (IVT) in acute ischemic stroke (AIS). The prediction of HT after IVT is important in the treatment decision-making for AIS. We designed and compared different machine learning methods, capable of predicting HT in AIS after IVT. A total of 345 AIS patients who received intravenous alteplase between January 2016 and June 2021 were enrolled in this retrospective study. The demographic characteristics, clinical condition, biochemical data, and neuroimaging variables were included for analysis. HT was confirmed by head computed tomography (CT) or magnetic resonance imaging (MRI) within 48 h after IVT. Based on the neuroimaging results, all of the patients were divided into the non-HT group and the HT group. Then, the variables were applied in logistic regression (LR) and random forest (RF) algorithms to establish HT prediction models. To evaluate the accuracy of the machine learning models, the models were compared to several of the common scales used in clinics, including the multicenter stroke survey (MSS) score, safe implementation of treatments in stroke (SITS) score, and SEDAN score. The performance of these prediction models was evaluated using the receiver operating characteristic (ROC) curve (AUC). Forty-five patients had HT (13.0%) within 48 h after IVT. The ROC curve results showed that the AUCs of HT that were predicted by the RF model, LR model, MSS, SITS, and SEDAN scales after IVT were 0.795 (95% CI, 0.647–0.944), 0.703 (95% CI, 0.515–0.892), 0.657 (95% CI, 0.574–0.741), 0.660 (95% CI, 0.580–0.740) and 0.655 (95% CI, 0.571–0.739), respectively. The RF model performed better than the other models and scales. The top four most influential factors in the RF importance matrix plot were triglyceride, Lpa, the baseline NIHSS, and hemoglobin. The SHapley Additive exPlanation values made the RF prediction model clinically interpretable. In this study, an RF machine learning method was successfully established to predict HT in AIS patients after intravenous alteplase, which the sensitivity was 66.7%, and the specificity was 80.7%.

Predictive values of Baseline MMP9 Levels in Peripheral Blood on 3-Month outcomes of high-risk patients with minor stroke or TIA

OBJECTIVE

To explore the relationship between baseline levels of matrix metalloproteinase 9 (MMP9) in peripheral blood and the outcomes in patients with acute minor stroke and transient ischemic attack (TIA).

METHODS

We assessed data from patients with acute minor ischemic stroke or TIA who were included in the CHANCE trial. Baseline level of MMP9 in peripheral blood is classified into five quintiles. We assessed the relationship between the baseline MMP9 and outcomes of stroke recurrence, composite vascular events, and poor functional outcomes within 90 days after stroke onset.

RESULTS

Of the 3014 patients included, 295 (9.79%) had recurrent stroke, 289 (9.59%) had recurrent ischemic stroke, 297 (9.85%) had combined vascular events, and 199 (6.64%) had poor functional outcomes within 90 days. Using MMP9 concentrations near HR = 1 (Q3) in restricted cubic splines as the reference. The result showed that, compared to patients in Q3 group, patients in the highest quintile (Q5 group) had an increased risk of poor functional outcomes at 90 days after adjusted the risk factors and confounders (P = 0.030), may be associated with an increased risk of combined vascular events (P = 0.052). Using Cox regression models or logistic regression models with restricted cubic spline, we also observed that higher MMP9 ratios were associated with an increased risk of stroke recurrence, combined events, and poor functional outcomes at a range of concentrations.

CONCLUSIONS

For patients with acute minor stroke or TIA, higher baseline MMP9 level was associated with an increased risk of poor functional outcomes, might be related to stroke recurrence and combined vascular events.

Small Vessel Disease: Ancient Description, Novel Biomarkers

Small vessel disease (SVD) is one of the most frequent pathological conditions which lead to dementia. Biochemical and neuroimaging might help correctly identify the clinical diagnosis of this relevant brain disease. The microvascular alterations which underlie SVD have common origins, similar cognitive outcomes, and common vascular risk factors. Nevertheless, the arteriolosclerosis process, which underlines SVD development, is based on different mechanisms, not all completely understood, which start from a chronic hypoperfusion state and pass through a chronic brain inflammatory condition, inducing a significant endothelium activation and a consequent tissue remodeling action. In a recent review, we focused on the pathophysiology of SVD, which is complex, involving genetic conditions and different co-morbidities (i.e., diabetes, chronic hypoxia condition, and obesity). Currently, many points still remain unclear and discordant. In this paper, we wanted to focus on new biomarkers, which can be the expression of the endothelial dysfunction, or of the oxidative damage, which could be employed as markers of disease progression or for future targets of therapies. Therefore, we described the altered response to the endothelium-derived nitric oxide-vasodilators (ENOV), prostacyclin, C-reactive proteins, and endothelium-derived hyperpolarizing factors (EDHF). At the same time, due to the concomitant endothelial activation and chronic neuroinflammatory status, we described hypoxia-endothelial-related markers, such as HIF 1 alpha, VEGFR2, and neuroglobin, and MMPs. We also described blood–brain barrier disruption biomarkers and imaging techniques, which can also describe perivascular spaces enlargement and dysfunction. More studies should be necessary, in order to implement these results and give them a clinical benefit.

Down-regulation of circular RNA CDC14A peripherally ameliorates brain injury in acute phase of ischemic stroke

Background

Inflammation is integral to the pathophysiology of ischemic stroke and a prime target for the development of new stroke therapies. The aim of the present study is to seek out the regulatory mechanism of circCDC14A in neuroinflammatory injury in tMCAO mice.

Methods

The expression level of circCDC14A in peri-infarct cortex and plasma of mice were detected by qPCR. The localization of circCDC14A in peripheral blood cells and peri-infarct cortex of tMCAO mice were explored by in situ hybridization and immunofluorescence colocalization staining. Lentivirus were microinjected into lateral ventricular of brain or injected into tail vein to interfere with the expression of circCDC14A, thus their effects on behavior, morphology, and molecular biology of tMCAO mice were analyzed.

Results

The expression of circCDC14A in plasma and peri-infarct cortex of tMCAO mice significantly increased, and circCDC14A was mainly localized in neutrophils peripherally while in astrocytes in peri-infarct cortex centrally. Tail vein injection of lentivirus to interfere with the expression of circCDC14A significantly reduced the infarct volume (P < 0.01) at 72 h after reperfusion and density of activated astrocytes in peri-infarct cortex at 3 days, 5 days and 7 days after tMCAO modeling (all P < 0.0001). Moreover, mNSS (P < 0.0001) and survival rate (P < 0.001) were significantly improved within 7 days in si-circCDC14A group compared to circCon group. Additionally, morphology analysis showed the volume and surface area of each activated astrocytes significantly decreased (P < 0.0001). Quantification analysis measured the percentage of N2 phenotype among infiltrated neutrophils in brain sections and found N2 ratio was significantly higher in si-circCDC14A group compared to circCon group (P < 0.001).

Conclusion

Knocking down the expression of circCDC14A in peripheral blood cells relieved astrocytes activation in peri-infarct cortex, thereby relieved brain damage in the acute phase of ischemic stroke.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02333-6.

Analysis of Metabolite and Lipid Association Networks Reveals Molecular Mechanisms Associated with 3-Month Mortality and Poor Functional Outcomes in Patients with Acute Ischemic Stroke after Thrombolytic Treatment with Recombinant Tissue Plasminogen Activator

Here, we present an integrated multivariate, univariate, network reconstruction and differential analysis of metabolite–metabolite and metabolite–lipid association networks built from an array of 18 serum metabolites and 110 lipids identified and quantified through nuclear magnetic resonance spectroscopy in a cohort of 248 patients, of which 22 died and 82 developed a poor functional outcome within 3 months from acute ischemic stroke (AIS) treated with intravenous recombinant tissue plasminogen activator. We explored differences in metabolite and lipid connectivity of patients who did not develop a poor outcome and who survived the ischemic stroke from the related opposite conditions. We report statistically significant differences in the connectivity patterns of both low- and high-molecular-weight metabolites, implying underlying variations in the metabolic pathway involving leucine, glycine, glutamine, tyrosine, phenylalanine, citric, lactic, and acetic acids, ketone bodies, and different lipids, thus characterizing patients’ outcomes. Our results evidence the promising and powerful role of the metabolite–metabolite and metabolite–lipid association networks in investigating molecular mechanisms underlying AIS patient’s outcome.

Combination treatment with U0126 and rt-PA prevents adverse effects of the delayed rt-PA treatment after acute ischemic stroke

In acute ischemic stroke, the only FDA-approved drug; recombinant tissue plasminogen activator (rt-PA) is limited by restricted time-window due to an enhanced risk of hemorrhagic transformation which is thought to be caused by metalloproteinase (MMP). In experimental stroke inhibitors of the mitogen–activated protein kinase kinase extracellular signal–regulated kinase kinase (MEK) 1/2 pathways reduce the MMPs. This study evaluated whether a MEK1/2 inhibitor in combination with rt-PA can prevent the detrimental effects of delayed rt-PA therapy in stroke. Thromboembolic stroke was induced in C57 black/6J mice and the MEK1/2 inhibitor U0126 was administrated 3.5 h and rt-PA 4 h post stroke-onset. Treatment with rt-PA demonstrated enhanced MMP-9 protein levels and hemorrhagic transformation which was prevented when U0126 was given in conjunction with rt-PA. By blocking the MMP-9 with U0126 the safety of rt-PA administration was improved and demonstrates a promising adjuvant strategy to reduce the harmful effects of delayed rt-PA treatment in acute ischemic stroke.

TT genotype of the MMP-9-1562C/T polymorphism may be a risk factor for thrombolytic therapy-induced hemorrhagic complications after acute ischemic stroke

INTRODUCTION

Levels of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) influence recombinant tissue plasminogen activator (rtPA) therapy response in patients with acute ischemic stroke (AIS). Serum levels of MMPs and TIMPs along with the expression of genes coding these proteins are related to the recovery and appearance of adverse effects (AE) after AIS. Consequently, it is important to explore whether polymorphisms in regulatory sequences of MMPs and TIMPs are associated with rtPA response in AIS patients.

OBJECTIVES

To determine whether selected polymorphic variants within MMP-2, MMP-9, and TIMP-2 genes may influence rtPA therapy response with regard to outcomes in patients with AIS and the occurrence of AE.

METHODS

Our study included 166 patients suffering AIS, treated with rtPA. Patients' recovery was estimated using the Modified Rankin Scale (mRS) 3 months after the AIS occurred. Favorable outcome was defined with scores 0-1 and poor outcome with scores 2-6. Genotyping was performed using real-time PCR (rs243866, rs243865, rs243864, rs2277698, and rs8179090) and PCR-RFLP (rs2285053, rs3918242) methods. Additionally, rtPA AE were followed during the hospitalization.

RESULTS

There was no significant association between genotypes and alleles of selected polymorphisms and rtPA therapy response measured through the decrease of the mRS score in patients with AIS. Intracranial hemorrhage, as well as parenchymal hematoma type 2, was significantly more frequent in patients with TT genotype of the MMP-9-1562C/T polymorphism (p = 0.047, p = 0.011, respectively). Patients with intracranial hemorrhages after rtPA were significantly more likely to have the TT genotype of TIMP-2-303C/T polymorphism and the TT genotype of MMP-9-1562C/T polymorphism (p < 0.001).

CONCLUSION

TT genotype of the MMP-9-1562C/T polymorphism may be a risk factor for rtPA-induced hemorrhagic complications after AIS.

Prognostic value of the neutrophil-to-lymphocyte ratio in acute ischemic stroke patients treated with intravenous thrombolysis: a systematic review and meta-analysis

Background

The relationship between the neutrophil-to-lymphocyte ratio (NLR) and poor prognostics in acute ischemic stroke (AIS) patients who receive intravenous thrombolysis (IVT) remains controversial. The purpose of this systematic review and meta-analysis was to evaluate the association between the NLR and poor prognosis after IVT. Furthermore, we aimed to determine whether the NLR at admission or post-IVT plays a role in AIS patients who received IVT.

Methods

The PubMed, Embase, Web of Science and China National Knowledge Infrastructure databases were searched for relevant articles until October 7, 2020. Cohort and case-control studies were included if they were related to the NLR in AIS patients treated with IVT. Odds ratios (ORs) and 95 % confidence intervals (95 % CIs) were pooled to estimate the relationship between NLR and poor prognosis after IVT. A random effects model was used to calculate the pooled data.

Results

Twelve studies, including 3641 patients, met the predefined inclusion criteria. Higher NLRs were associated with an increased risk of hemorrhagic transformation (HT) (OR = 1.33, 95 % CI = 1.14–1.56, P < 0.001) and a poor 3-month functional outcome (OR = 1.64, 95 % CI = 1.38–1.94, P < 0.001) in AIS patients who received IVT. Subgroup analysis suggested that the NLR at admission rather than post-IVT was associated with a higher risk of HT (OR = 1.33, 95 % CI = 1.01–1.75, P = 0.039). There was no statistically significant difference between higher NLRs and 3-month mortality (OR = 1.14, 95 % CI = 0.97–1.35, P = 0.120).

Conclusions

A high NLR can predict HT and poor 3-month functional outcomes in AIS patients who receive IVT. The NLR at admission rather than the post-IVT NLR was an independent risk factor for an increased risk of HT after IVT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02222-8.

PPARγ activation suppresses the expression of MMP9 by downregulating NF-κB post intracerebral hemorrhage

Peroxisome proliferator-activated receptor-gamma (PPARγ) is critical in protecting against inflammatory and oxidative stresses post brain injury. We have previously reported that rosiglitazone, an agonist of PPARγ, was effective to prevent microglia from apoptosis and ameliorate neuronal injuries post intracerebral hemorrhage (ICH) with suppression of matrix metalloproteinase-9 (MMP9) expression. However, molecular mechanisms linking how PPARγ decreases MMP9 remain unknown. Here, we hypothesize that PPARγ downregulates MMP9 expression post hemorrhage by inhibiting nuclear factor kappa B (NF-κB), an upstream regulator of MMPs gene and also key transcription factor involved in the control of immune and neuroinflammatory responses. We found both in vivo and in vitro that PPARγ was significantly downregulated post ICH with prominent increases of NF-κB and MMP9. Activation of PPARγ using rosiglitazone decreased the expression of both NF-κB and MMP9, while reversed effects were observed when administrating the PPARγ antagonist GW9662. Besides, inhibiting NF-κB by JSH-23 also suppressed the expression of MMP9, with only limited effect on PPARγ. Further studies revealed prominent colocalizations of NF-κB with PPARγ and MMP9, respectively. Finally, direct interactions of NF-κB with PPARγ and MMP9 gene were also confirmed, respectively, by protein and chromatin immunoprecipitations. These results suggested a role of NF-κB in mediating the reduction of MMP9 by PPARγ, potentially providing a new therapeutic target for brain hemorrhage.

Association of Matrix Metalloproteinase 9 and Cellular Fibronectin and Outcome in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Introduction: The role of matrix metalloproteinase 9 (MMP-9) and cellular fibronectin (c-Fn) in acute ischemic stroke is controversial. We systematically reviewed the literature to investigate the association of circulating MMP-9 and c-Fn levels and MMP-9 rs3918242 polymorphism with the risk of three outcome measures after stroke.

Methods: We searched English and Chinese databases to identify eligible studies. Outcomes included severe brain edema, hemorrhagic transformation, and poor outcome (modified Rankin scale score ≥3). We estimated standardized mean differences (SMDs) and pooled odds ratios (ORs) with 95% confidence intervals (CIs).

Results: Totally, 28 studies involving 7,239 patients were included in the analysis of circulating MMP-9 and c-Fn levels. Meta-analysis indicated higher levels of MMP-9 in patients with severe brain edema (SMD, 0.76; 95% CI, 0.18–1.35; four studies, 419 patients) and hemorrhagic transformation (SMD, 1.00; 95% CI, 0.41–1.59; 11 studies, 1,709 patients) but not poor outcome (SMD, 0.30; 95% CI, −0.12 to 0.72; four studies, 759 patients). Circulating c-Fn levels were also significantly higher in patients with severe brain edema (SMD, 1.55; 95% CI, 1.18–1.93; four studies, 419 patients), hemorrhagic transformation (SMD, 1.75; 95% CI, 0.72–2.78; four studies, 458 patients), and poor outcome (SMD, 0.46; 95% CI, 0.16–0.76; two studies, 210 patients). Meta-analysis of three studies indicated that the MMP-9 rs3918242 polymorphism may be associated with hemorrhagic transformation susceptibility under the dominant model (TT + CT vs. CC: OR, 0.621; 95% CI, 0.424–0.908; P = 0.014). No studies reported the association between MMP-9 rs3918242 polymorphism and brain edema or functional outcome after acute stroke.

Conclusion: Our meta-analysis showed that higher MMP-9 levels were seen in stroke patients with severe brain edema and hemorrhagic transformation but not poor outcome. Circulating c-Fn levels appear to be associated with all three outcomes including severe brain edema, hemorrhagic transformation, and poor functional outcome. The C-to-T transition at the MMP-9 rs3918242 gene appears to reduce the risk of hemorrhagic transformation.

YiQiFuMai Lyophilized Injection ameliorates tPA-induced hemorrhagic transformation by inhibiting cytoskeletal rearrangement associated with ROCK1 and NF-κB signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Thrombolytic therapy with tissue plasminogen activator (tPA) after ischemic stroke exacerbates blood-brain barrier (BBB) breakdown and leads to hemorrhagic transformation (HT). YiQiFuMai Lyophilized Injection (YQFM) is a modern preparation derived from Sheng-mai San (a traditional Chinese medicine). YQFM attenuates the BBB dysfunction induced by cerebral ischemia-reperfusion injury. However, whether YQFM can suppress tPA-induced HT remains unknown.

AIM OF THE STUDY

We investigated the therapeutic effect of YQFM on tPA-induced HT and explored the underlying mechanisms in vivo and in vitro to improve the safety of tPA use against stroke.

METHODS

Male C57BL/6J mice were subjected to 45 min of ischemia and 24 h of reperfusion. tPA (10 mg/kg) were infused 2 h after occlusion and YQFM (0.671 g/kg) was injected 2.5 h after occlusion. The in vitro effect of YQFM (100, 200, 400 μg/mL) on tPA (60 μg/mL)-induced dysfunction of the microvascular endothelial barrier in the brain following oxygen-glucose deprivation/reoxygenation (OGD/R) was observed in bEnd.3 cells.

RESULTS

YQFM suppressed tPA-induced high hemoglobin level in the brain, mortality, neurologic severity score, BBB permeability, expression and activation of matrix metalloproteinase (MMP)-9 and MMP-2, and degradation of tight-junction proteins. Furthermore, YQFM significantly blocked tPA-induced brain microvascular endothelial permeability and phosphorylation of Rho-associated kinase (ROCK)1, myosin light chain (MLC), cofilin and p65 in vivo and in vitro.

CONCLUSION

YQFM suppressed tPA-induced HT by inhibiting cytoskeletal rearrangement linked with ROCK-cofilin/MLC pathways and inhibiting the nuclear factor-kappa B pathway to ameliorate BBB damage caused by tPA.

Hemorrhagic Transformation After Tissue Plasminogen Activator Treatment in Acute Ischemic Stroke

Hemorrhagic transformation (HT) is a common complication after thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) in ischemic stroke. In this article, recent research progress of HT in vivo and in vitro studies was reviewed. We have discussed new potential mechanisms and possible experimental models of HT development, as well as possible biomarkers and treatment methods. Meanwhile, we compared and analyzed rodent models, large animal models and in vitro BBB models of HT, and the limitations of these models were discussed. The molecular mechanism of HT was investigated in terms of BBB disruption, rt-PA neurotoxicity and the effect of neuroinflammation, matrix metalloproteinases, reactive oxygen species. The clinical features to predict HT were represented including blood biomarkers and clinical factors. Recent progress in neuroprotective strategies to improve HT after stroke treated with rt-PA is outlined. Further efforts need to be made to reduce the risk of HT after rt-PA therapy and improve the clinical prognosis of patients with ischemic stroke.

Combined utility of blood glucose and white blood cell in predicting outcome after acute ischemic stroke: The ENCHANTED trial

BACKGROUND

As hyperglycemia and leukocytosis individually predict poor outcome in acute ischemic stroke (AIS), we aimed to determine the significance of their combination on functional outcome and symptomatic intracerebral hemorrhage (sICH) among participants of the Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED).

METHODS

Post-hoc analyzes of the full ENCHANTED cohort, an international, multicenter, quasi-factorial, randomized, open, blinded outcome-assessed trial of low- versus standard-dose intravenous alteplase and early intensive versus standard blood pressure (BaP) lowering treatment in 4557 thrombolysis-eligible and treated AIS patients. Patients were divided into four groups according to baseline blood glucose and white blood cells (WBC) levels: A (normal glucose + WBC), B (hyperglycemia + normal WBC), C (normal glucose + high WBC), and D (hyperglycemia + high WBC). Logistic regression models were used to determine associations of each group and poor functional outcome (modified Rankin scale scores 2-6) at 90 days and sICH within 48 h, adjusted for confounders. Quality of model fit was examined with Akaike information classification (AIC), Bayesian information classification (BIC), and likelihood ratio test.

RESULTS

Of 4181 AIS patients included in analyzes, and with group A as the reference, an increasing odds of poor functional outcome was evident across groups B (odds ratio [OR] 1.38, 95 % confidence interval [CI] 1.17-1.63), C (OR 1.26, 95 %CI 0.99-1.60), and D (OR 2.26, 95 %CI 1.79-2.85) (P trend <0.001). Group D patients also had a higher rate of sICH (P trend <0.05). The model fit with the combination of blood glucose and WBC was better than models of their individual components.

CONCLUSIONS

Using a combination of blood glucose and WBC provides strong prognostic significance than either alone in thrombolyzed AIS patients.

Development of Brain Targeting Peptide Based MMP-9 Inhibiting Nanoparticles for the Treatment of Brain Diseases with Elevated MMP-9 Activity

Latent and active levels of cerebral matrix metalloproteinase 9 (MMP-9) are elevated in neurological diseases and brain injuries, contributing to neurological damage and poor clinical outcomes. This study aimed developing peptide-based nanoparticles with ability to cross the blood-brain-barrier (BBB) and inhibit MMP-9. Three amphiphilic peptides were synthesised containing brain-targeting ligands (HAIYPRH or CKAPETALC) conjugated with MMP-9 inhibiting peptide (CTTHWGFTLC) linked by glycine (spacer) at the N-terminus, and the peptide sequences were conjugated at the N- terminus to cholesterol. ¹⁹F NMR assay was developed to measure MMP-9 inhibition. Cell toxicity was evaluated by the LDH assay, and dialysis studies were conducted with/without fetal bovine serum. An in vitro model was employed to evaluate the ability of nanoparticles crossing the BBB. The amphiphilic peptide (Cholesterol-GGGCTTHWGFTLCHAIYPRH) formed nanoparticles (average size of 202.8 nm) with ability to cross the BBB model. MMP-9 inhibiting nanoparticles were non-toxic to cells, and reduced MMP-9 activity from kobs of 4.5 × 10^-6s^-1 to complete inhibition. Dialysis studies showed that nanoparticles did not disassemble by extreme dilution (40 folds), but gradually hydrolysed by serum enzymes. In conclusion, the MMP-9 inhibiting nanoparticles reduced the activity of MMP-9, with acceptable serum stability, minimal cell toxicity and ability to cross the in vitro BBB model.

Matrix Metalloproteinase-9 Relationship With Infarct Growth and Hemorrhagic Transformation in the Era of Thrombectomy

Objective: To assess the relationship between matrix metalloproteinase 9 (MMP-9), a proteolytic enzyme involved in the breakdown of the blood-brain barrier, and infarct growth and hemorrhagic transformation in acute ischemic stroke (AIS) with large vessel occlusion (LVO) in the era of mechanical thrombectomy (MT) using the kinetics of MMP-9 and sequential magnetic resonance imaging (MRI).

Methods: HIBISCUS-STROKE is a cohort study including AIS patients with LVO treated with MT following admission MRI. Patients underwent sequential assessment of MMP-9, follow-up CT at day 1, and MRI at day 6. The CT scan at day 1 classified any hemorrhagic transformation according to the European Co-operative Acute Stroke Study-II (ECASS II) classification. Infarct growth was defined as the difference between final Fluid-Attenuated Inversion Recovery volume and baseline diffusion-weighted imaging volume. Conditional logistic regression analyses were adjusted for main confounding variables including reperfusion status.

Results: One hundred and forty-eight patients represent the study population. A high MMP-9 level at 6 h from admission (H6) (p = 0.02), a high glucose level (p = 0.01), a high temperature (p = 0.04), and lack of reperfusion (p = 0.02) were associated with infarct growth. A high MMP-9 level at H6 (p = 0.03), a high glucose level (p = 0.03) and a long delay from symptom onset to groin puncture (p = 0.01) were associated with hemorrhagic transformation.

Conclusions: In this MT cohort study, MMP-9 level at H6 predicts infarct growth and hemorrhagic transformation.

Toll-Like Receptor 4 Signaling in Focal Cerebral Ischemia: a Focus on the Neurovascular Unit

A robust innate immune activation leads to downstream expression of inflammatory mediators that amplify tissue damage and consequently increase the morbidity after stroke. The Toll-like receptor 4 (TLR4) pathway is a major innate immune pathway activated acutely and chronically after stroke. Hence, understanding the intricacies of the temporal profile, specific control points, and cellular specificity of TLR4 activation is crucial for the development of any novel therapeutics targeting the endogenous innate immune response after focal cerebral ischemia. The goal of this review is to summarize the current findings related to TLR4 signaling after stroke with a specific focus on the components of the neurovascular unit such as astrocytes, neurons, endothelial cells, and pericytes. In addition, this review will examine the effects of focal cerebral ischemia on interaction of these neurovascular unit components.

Analysis of the association of MPO and MMP-9 with stroke severity and outcome: Cohort study

OBJECTIVE

In acute cerebral ischemia, circulating neutrophil count and neutrophil-to-lymphocyte ratio (NLR) are positively associated with stroke severity and worse outcomes. Mediators of this effect are unknown. We aimed to investigate (1) the relationship between plasma matrix metalloproteinase-9 (MMP-9) and myeloperoxidase (MPO) concentrations with stroke severity and outcome and (2) MMP-9 and MPO release after ex vivo stimulation of neutrophils by recombinant tissue plasminogen activator (rtPA).

METHODS

We analyzed data collected in 255 patients with supratentorial cerebral infarcts recruited within 48 hours of symptoms onset irrespective of rtPA treatment. The endpoints were excellent outcome (modified Rankin Scale score 0-1), symptomatic intracerebral hemorrhage (European Cooperative Acute Stroke Study-II definition), and death at 3 months. The role of rtPA treatment on peripheral neutrophil degranulation was investigated in 18 patients within 4.5 hours and after 72 hours.

RESULTS

Neutrophil counts, NLR, and MPO plasma concentrations, but not MMP-9, were positively correlated with stroke severity. Higher neutrophil counts and NLR were independently associated with worse outcomes and higher mortality rates at month 3. Higher MPO plasma concentrations, but not MMP-9, were associated with worse outcome. Neutrophil-derived MMP-9, after ex vivo rtPA stimulation, but not MPO, were higher after 72 hours in patients treated by IV rtPA but not associated with hemorrhagic transformation.

CONCLUSIONS

Neutrophil counts, NLR, and MPO plasma concentrations are associated with worse outcome in patients with acute cerebral ischemia, in contrast to MMP-9. Further investigations are needed to deepen our knowledge on MPO's role in the deleterious effect of neutrophils because it could represent a potential therapeutic target.

Blood Biomarkers of Parenchymal Damage in Ischemic Stroke Patients Treated With Revascularization Therapies

Purpose

Postischemic reperfusion injury may exacerbate cerebral damage and capillary dysfunction, leading to brain edema (BE), hemorrhagic transformation (HT), necrosis, and injury from free radicals with subsequent infarct growth (IG). Several plasmatic biomarkers involved in the ischemic cascade have been studied in relation to radiological and clinical outcomes of reperfusion injury in ischemic stroke with heterogeneous results. This article provides a brief overview of the contribution of circulating biomarkers to the pathophysiology of parenchymal damage in ischemic stroke patients treated with revascularization therapies.

Methods

We included full reports with measurements of plasma markers in patients with acute ischemic stroke treated with revascularization therapies.

Findings

Our research included a large number of observational studies investigating a possible role of circulating biomarkers in the development of parenchymal damage after acute stroke treatments. To make the results clearer, we divided the review in 4 sections, exploring the relation of different biomarkers with each of the indicators of parenchymal damage (HT, BE, IG, recanalization).

Discussion and conclusion

Definite conclusions are difficult to draw because of heterogeneity across studies. However, our review seems to confirm an association between some circulating biomarkers (particularly matrix metalloproteinase-9) and occurrence of parenchymal damage in ischemic stroke patients treated with revascularization therapies.

Iron Overload Exacerbates the Risk of Hemorrhagic Transformation After tPA (Tissue-Type Plasminogen Activator) Administration in Thromboembolic Stroke Mice

Background and Purpose- Recanalization with tPA (tissue-type plasminogen activator) is the only pharmacological therapy available for patients with ischemic stroke. However, the percentage of patients who may receive this therapy is limited by the risk of hemorrhagic transformation (HT)-the main complication of ischemic stroke. Our aim is to establish whether iron overload affects HT risk, to identify mechanisms that could help to select patients and to prevent this devastating complication. Methods- Mice fed with control or high-iron diet were subjected to thromboembolic stroke, with or without tPA therapy at different times after occlusion. Blood samples were collected for determination of malondialdehyde, matrix metalloproteinases, and fibronectin. Brain samples were collected 24 hours after occlusion to determine brain infarct and edema size, hemorrhage extension, IgG extravasation, and inflammatory and oxidative markers (neutrophil infiltration, 4-hydroxynonenal, and matrix metalloproteinase-9 staining). Results- Despite an increased rate of recanalization, iron-overload mice showed less neuroprotection after tPA administration. Importantly, iron overload exacerbated the risk of HT after early tPA administration, accelerated ischemia-induced serum matrix metalloproteinase-9 increase, and enhanced basal serum lipid peroxidation. High iron increased brain lipid peroxidation at most times and neutrophil infiltration at the latest time studied. Conclusions- Our data showing that iron overload increases the death of the compromised tissues, accelerates the time of tPA-induced reperfusion, and exacerbates the risk of HT may have relevant clinical implications for a safer thrombolysis. Patients with stroke with iron overload might be at high risk of HT after fibrinolysis, and, therefore, clinical studies must be performed to confirm our results.

High serum levels of tissue inhibitor of matrix metalloproteinase-1 during the first week of a malignant middle cerebral artery infarction in non-surviving patients

Background

Higher circulating levels of tissue inhibitor of matrix metalloproteinases (TIMP)-1 early after ischemic stroke have been associated with lower survival. The objectives of this study were to determine serum TIMP-1 levels during the first week of a severe cerebral infarction in surviving and non-surviving patients, and whether those levels during the first week could be used as a mortality biomarker for these patients.

Methods

We included patients with severe malignant middle cerebral artery infarction (MMCAI) defined as computer tomography showing ischaemic changes in more than 50% of the middle cerebral artery territory and Glasgow Coma Scale (GCS) ≤ 8. We measured serum levels of matrix metalloproteinases (MMP)-9 and TIMP-1. End-point study was 30-day mortality.

Results

We found higher TIMP-1 concentrations at days 1 (p < 0.001), 4 (p = 0.001), and 8 (p = 0.03) of MMCAI in non- urviving (n = 34) than in surviving (n = 34) patients. We found lower serum MMP-9 concentrations at day 1 (p = 0.03) of MMCAI and no significant differences at days 4 and 8. ROC curve analysis of TIMP-1 concentrations performed at days 1, 4, and 8 of MMCAI showed an area under curve to predict 30-day mortality of 81% (p < 0.001), 80% (p < 0.001) and 72% (p = 0.07) respectively.

Conclusions

The new findings of our study were that non-surviving MMCAI patients showed higher serum TIMP-1 levels during the first week of MMCAI that surviving patients, and those levels during the first week of MMCAI could be used as mortality biomarkers.

Renin-angiotensin system activation and imbalance of matrix metalloproteinase-9/tissue inhibitor of matrix metalloproteinase-1 in cold-induced stroke

AIMS

In the present study, we investigated the roles of renin-angiotensin system (RAS) activation and imbalance of matrix metalloproteinase-9 (MMP-9)/tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in cold-induced stroke during chronic hypertension, as well as the protective effects of captopril and recombinant human TIMP-1 (rhTIMP-1).

MAIN METHODS

Rats were randomly assigned to sham; 2-kidney, 2-clip (2K-2C); 2K-2C + captopril, and 2K-2C + rhTIMP-1 groups. After blood pressure values had stabilized, each group was randomly divided into an acute cold exposure (ACE) group (12-h light at 22 °C/12-h dark at 4 °C) and a non-acute cold exposure (NACE) group (12-h light/12-h dark at 22 °C), each of which underwent three cycles of exposure. Captopril treatment was administered via gavage (50 mg/kg/d), while rhTIMP-1 treatment was administered via the tail vein (60 μg/kg/36 h).

KEY FINDINGS

In the 2K-2C group, angiotensin II (AngII) and MMP-9 levels increased in both the plasma and cortex, while no such changes in TIMP-1 expression were observed. Cold exposure further upregulated AngII and MMP-9 levels and increased stroke incidence. Captopril and rhTIMP-1 treatment inhibited MMP-9 expression and activation and decreased stroke incidence in response to cold exposure.

SIGNIFICANCE

The present study is the first to demonstrate that cold exposure exacerbates imbalance between MMP-9 and TIMP-1 by activating the RAS, which may be critical in the initiation of stroke during chronic hypertension. In addition, our results suggest that captopril and rhTIMP-1 exert protective effects against cold-induced stroke by ameliorating MMP-9/TIMP-1 imbalance.

Targeting Platelet GPVI Plus rt-PA Administration but Not α2β1-Mediated Collagen Binding Protects against Ischemic Brain Damage in Mice

Platelet collagen interactions at sites of vascular injuries predominantly involve glycoprotein VI (GPVI) and the integrin α2β1. Both proteins are primarily expressed on platelets and megakaryocytes whereas GPVI expression is also shown on endothelial and integrin α2β1 expression on epithelial cells. We recently showed that depletion of GPVI improves stroke outcome without increasing the risk of cerebral hemorrhage. Genetic variants associated with higher platelet surface integrin α2 (ITGA2) receptor levels have frequently been found to correlate with an increased risk of ischemic stroke in patients. However until now, no preclinical stroke study has addressed whether platelet integrin α2β1 contributes to the pathophysiology of ischemia/reperfusion (I/R) injury. Focal cerebral ischemia was induced in C57BL/6 and Itga2^-/- mice by a 60 min transient middle cerebral artery occlusion (tMCAO). Additionally, wild-type animals were pretreated with anti-GPVI antibody (JAQ1) or Fab fragments of a function blocking antibody against integrin α2β1 (LEN/B). In anti-GPVI treated animals, intravenous (IV) recombinant tissue plasminogen activator (rt-PA) treatment was applied immediately prior to reperfusion. Stroke outcome, including infarct size and neurological scoring was determined on day 1 after tMCAO. We demonstrate that targeting the integrin α2β1 (pharmacologic; genetic) did neither reduce stroke size nor improve functional outcome on day 1 after tMCAO. In contrast, depletion of platelet GPVI prior to stroke was safe and effective, even when combined with rt-PA treatment. Our results underscore that GPVI, but not ITGA2, is a promising and safe target in the setting of ischemic stroke.

Small Vessel Disease Is Associated with Tissue Inhibitor of Matrix Metalloproteinase-4 After Ischaemic Stroke

Small vessel disease (SVD) is frequent in aging and stroke patients. Inflammation and remodeling of extracellular matrix have been suggested as concurrent mechanisms of SVD. We investigated the relationship between imaging features of SVD and circulating metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in patients with ischaemic stroke. In patients treated with intravenous thrombolysis, we took blood samples before intravenous thrombolysis and 90 days after the acute stroke and analysed levels of MMPs and TIMPs. We assessed leukoaraiosis, number of lacunes and brain atrophy on pre-treatment CT scan and graded global SVD burden combining such features. We investigated associations between single features, global SVD and MMPs and TIMPs at baseline and at follow-up, retaining univariate statistically significant associations in multivariate linear regression analysis and adjusting for clinical confounders. A total of 255 patients [mean (±SD) = 68.6 (± 12.7) years, 154 (59%) males] were included, 107 (42%) had no signs of SVD; 47 (19%) had from moderate to severe SVD burden. A total of 107 (42%) patients had no signs of SVD; 47 (19%) had from moderate to severe SVD burden. After adjustment, only TIMP-4 proved associations with SVD features. Brain atrophy was associated with baseline TIMP-4 (β = 0.20;p = 0.019) and leukoaraiosis with 90 days TIMP-4 (β = 0.19; p = 0.013). Global SVD score was not associated with baseline TIMP-4 levels (β = 0.10; p = 0.072), whereas was associated with 90 days TIMP-4 levels (β = 0.21; p = 0.003). Total SVD burden was associated with higher TIMP-4 levels 90 days after stroke, whereas was not during the acute phase. Our results support a biological relationship between SVD grade and TIMP-4.

Differential leukocyte counts on admission predict outcomes in patients with acute ischaemic stroke treated with intravenous thrombolysis

BACKGROUND AND PURPOSE

To determine the association of differential leukocyte counts on admission with efficacy and safety outcomes in patients with acute ischaemic stroke (AIS) treated with intravenous thrombolysis (IVT).

METHODS

Consecutive patients with AIS receiving IVT were evaluated at two stroke centers. Differential leukocyte counts and neutrophil:lymphocyte ratio (NLR) were determined during the initial 12 h of admission. Efficacy outcomes were favorable functional outcome (FFO) (modified Rankin Scale scores of 0-1) and functional independence (FI) (modified Rankin Scale scores of 0-2) at 3 months, whereas safety outcomes were symptomatic intracranial hemorrhage and 3-month mortality.

RESULTS

Among 657 IVT-treated patients with AIS, the mean age was 64 ± 14 years, 50% were female and median National Institutes of Health Stroke Scale score was 7 points (interquartile range, 4-13). Lower neutrophil and leukocyte counts and NLR counts were observed in patients with 3-month FFO and FI, whereas higher counts were observed in patients who died at 3 months. The best discriminative factors for 3-month FFO and FI were NLR < 2.2 (sensitivity 51.4%, specificity 63.1%) and leukocyte count <8100/μL (sensitivity 57.5%, specificity 55.1%), respectively. After adjustment for potential confounders, NLR < 2.2 was associated with higher odds of FFO [odds ratio (OR), 1.56; 95% confidence interval (CI), 1.08-2.24; P = 0.018], whereas leukocyte count <8100/μL demonstrated higher odds of 3-month FI (OR, 1.69; 95% CI, 1.11-2.57; P = 0.014) and lower odds of 3-month mortality (OR, 0.31; 95% CI, 0.16-0.60; P = 0.001). Combined neutrophil (<6800/μL) and leukocyte (<8100/μL) counts demonstrated a strong interaction for 3-month FI (OR, 1.73; 95% CI, 1.13-2.67; P interaction = 0.012).

CONCLUSIONS

Differential leukocyte counts on admission were independently associated with clinical outcomes in patients with AIS treated with IVT. These inflammatory biomarkers are potential targets for adjunctive neuroprotection in this stroke subgroup.

MMP10 Promotes Efficient Thrombolysis After Ischemic Stroke in Mice with Induced Diabetes

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

Association between matrix metalloproteinase family gene polymorphisms and risk of ischemic stroke: A systematic review and meta-analysis of 29 studies

BACKGROUND

Ischemic stroke (IS) is a complex and devastating vascular disease that has become one of the leading causes of disability and mortality worldwide. Several studies have shown the association between matrix metalloproteinase (MMP) family gene polymorphisms and IS. However, the results have been indecisive.

OBJECTIVE

To investigate the association between Matrix Metalloproteinase gene polymorphisms and risk of IS.

METHODS

A literature search for eligible candidate gene studies published before, 28 June 2017, was conducted in the PubMed, EMBASE, Cochrane and Google Scholar databases. The following combinations of main keywords were used: ('Matrix Metalloproteinase' or 'MMP' or 'Stromelysin-1' or 'Gelatinase b') AND ('ischemic stroke' or 'IS') AND ('single nucleotide polymorphism' or 'gene polymorphism' or 'SNP'). Fixed or random effects models were used to estimate the Pooled Odds ratio (OR) and 95% confidence interval (CI). Statistical analysis was carried out by using STATA version 13.0 software.

RESULTS

Total 29 studies were included in our meta-analysis. A significant association was observed for MMP-9 (-1562C/T) (OR 1.27; 95% CI 1.06 to 1.53; p value = 0.01) and MMP-12 (-1082 A/G) (OR 2.55; 95% CI 1.75 to 3.71; p value<0.001) gene polymorphisms and risk of IS. No significant association was found for any of the MMP-1(-1607 1G/2G), MMP-2 (-1306C/T) & (-735C/T) and MMP-3 (-1612 5A/6A) gene polymorphisms with the risk of IS.

CONCLUSION

Our meta-analysis suggests that MMP-9 (-1562C/T) and MMP-12 (-1082 A/G) gene polymorphisms could be a risk factor for IS while MMP-1 (-1607 1G/2G), MMP-2 (-1306C/T) & (-735C/T) and MMP-3 (-1612 5A/6A) have no association with the risk of causing IS. However, large prospective studies with sufficient power are required to validate our findings.

Reperfusion Injury after ischemic Stroke Study (RISKS): single-centre (Florence, Italy), prospective observational protocol study

INTRODUCTION

Treatments aiming at reperfusion of the acutely ischaemic brain tissue may result futile or even detrimental because of the so-called reperfusion injury. The processes contributing to reperfusion injury involve a number of factors, ranging from blood-brain barrier (BBB) disruption to circulating biomarkers. Our aim is to evaluate the relative effect of imaging and circulating biomarkers in relation to reperfusion injury.

METHODS AND ANALYSIS

Observational hospital-based study that will include 140 patients who had ischaemic stroke, treated with systemic thrombolysis, endovascular treatment or both. BBB disruption will be assessed with CT perfusion (CTP) before treatment, and levels of a large panel of biomarkers will be measured before intervention and after 24 hours. Relevant outcomes will include: (1) reperfusion injury, defined as radiologically relevant haemorrhagic transformation at 24 hours and (2) clinical status 3 months after the index stroke. We will investigate the separate and combined effect of pretreatment BBB disruption and circulating biomarkers on reperfusion injury and clinical status at 3 months. Study protocol is registered at http://www.clinicaltrials.gov (ClinicalTrials.gov ID: NCT03041753).

ETHICS AND DISSEMINATION

The study protocol has been approved by ethics committee of the Azienda Ospedaliero Universitaria Careggi (Università degli Studi di Firenze). Informed consent is obtained by each patient at time of enrolment or deferred when the participant lacks the capacity to provide consent during the acute phase. Researchers interested in testing hypotheses with the data are encouraged to contact the corresponding author. Results from the study will be disseminated at national and international conferences and in medical thesis.

TRIAL REGISTRATION NUMBER

NCT03041753.

The Accuracy of Serum Matrix Metalloproteinase-9 for Predicting Hemorrhagic Transformation After Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Hemorrhagic transformation is a serious complication of acute ischemic stroke, which may cause detrimental outcomes and the delayed use of anticoagulation therapy. Early predicting and identifying the patients at high risk of hemorrhagic transformation before clinical deterioration occurrence become a research priority.

OBJECTIVE

To study the value of plasma matrix metalloproteinase-9 predicting hemorrhagic transformation after ischemic stroke.

METHODS

We searched PubMed, Ovid, Cochrane Library, and other 2 Chinese databases to identify literatures published up to September 2017 and performed meta-analysis by STATA (version 12.0, StataCorp LP, College Station, TX).

RESULTS

Twelve studies incorporating 1492 participants were included and 7 studies were included in the quantitative statistical analysis. The pooled sensitivity was 85% (95% confidence interval [CI]: 75%, 91%) and the pooled specificity was 79% (95% CI: 67%, 87%). The area under the receiver operating characteristic curve was .89 (95% CI .86, .91). Significant heterogeneity for all estimates value existed (all the P value < .05 and I² > 50%). There is no threshold effect with P value greater than .05 of the correlation coefficient. Meta-regression and subgroup analysis showed cut-off value and hemorrhagic subtype contributed to heterogeneity. Deeks' funnel plot indicated no significant publication bias for 7 quantitative analysis studies.

CONCLUSIONS

Matrix metalloproteinase-9 has high predictive value for hemorrhagic transformation after acute ischemic stroke. It may be useful to test matrix metalloproteinase-9 to exclude patients at low risk of hemorrhage for precise treatment in the future clinical work.

Influence of Thrombolysis on the Safety and Efficacy of Blocking Platelet Adhesion or Secretory Activity in Acute Ischemic Stroke in Mice

In acute ischemic stroke (AIS), there is an alarming discrepancy between recanalization rates of up to 70% by combined recombinant tissue-type plasminogen activator (rt-PA) therapy and mechanical thrombectomy, and no clinical benefit in at least every second stroke patient. This is partly due to ischemia/reperfusion (I/R) injury. In a translational approach, we used mice lacking dense- (Unc13d^-/-) or α-granules (Nbeal2^-/-) and mice after blocking of platelet glycoprotein receptor (GP) Ib conferring protection from I/R injury. These mice underwent transient middle cerebral artery occlusion (tMCAO) and, as in the clinic, were treated with rt-PA. Our data show that rt-PA treatment is still safe in conjunction with selected anti-platelet therapies and pave the way for eagerly awaited additive treatment options in acute human stroke.

Inflammatory and metalloproteinases profiles predict three-month poor outcomes in ischemic stroke treated with thrombolysis

Inflammatory mediators and metalloproteinases are altered in acute ischemic stroke (AIS) and play a detrimental effect on clinical severity and hemorrhagic transformation of the ischemic brain lesion. Using data from the Italian multicenter observational MAGIC (MArker bioloGici nell'Ictus Cerebrale) Study, we evaluated the effect of inflammatory and metalloproteinases profiles on three-month functional outcome, hemorrhagic transformation and mortality in 327 patients with AIS treated with intravenous thrombolys in according to SITS-MOST (Safe Implementation of Thrombolysis in Stroke-MOnitoring STudy) criteria. Circulating biomarkers were assessed at baseline and 24 h after thrombolysis. Adjusting for age, sex, baseline glycemia and National Institute of Health Stroke Scale, history of atrial fibrillation or congestive heart failure, and of inflammatory diseases or infections, baseline alpha-2macroglobulin (A2M), baseline serum amyloid protein (SAP) and pre-post tissue-plasminogen activator (tPA) variations (Δ) of metalloproteinase 9, remained significantly and independently associated with three-month death [OR (95% CI):A2M:2.99 (1.19-7.53); SAP:5.46 (1.64-18.74); Δmetalloproteinase 9:1.60 (1.12-2.27)]. The addition of baseline A2M and Δmetalloproteinase 9 or baseline SAP and Δmetalloproteinase 9 (model-2 or model-3) to clinical variables (model-1) significantly improved the area under curve for prediction of death [model-2 with A2M: p = 0.0205; model-3 with SAP: p = 0.001]. In conclusion, among AIS patients treated with thrombolysis, circulating A2M, SAP and Δmetalloproteinase 9 are independent markers of poor outcome. These results may prompt controlled clinical research about agents antagonizing their effect.

Neuroprotective effects of adjunctive treatments for acute stroke thrombolysis: a review of clinical evidence

The narrow therapeutic time window and risk of intracranial hemorrhage largely restrict the clinical application of thrombolysis in acute ischemic stroke. Adjunctive treatments added to rt-PA may be beneficial to improve the capacity of neural cell to withstand ischemia, and to reduce the hemorrhage risk as well. This review aims to evaluate the neuroprotective effects of adjunctive treatments in combination with thrombolytic therapy for acute ischemic stroke. Relevant studies were searched in the PubMed, Web of Science and EMBASE database. In this review, we first interpret the potential role of adjunctive treatments to thrombolytic therapy in acute ischemic stroke. Furthermore, we summarize the current clinical evidence for the combination of intravenous recombinant tissue plasminogen activator and various adjunctive therapies in acute ischemic stroke, either pharmacological or non-pharmacological therapy, and discuss the mechanisms of some promising treatments, including uric acid, fingolimod, minocycline, remote ischemic conditioning, hypothermia and transcranial laser therapy. Even though fingolimod, minocycline, hypothermia and remote ischemic conditioning have yielded promising results, they still need to be rigorously investigated in further clinical trials. Further trials should also focus on neuroprotective approach with pleiotropic effects or combined agents with multiple protective mechanisms.

Update on Inflammatory Biomarkers and Treatments in Ischemic Stroke

After an acute ischemic stroke (AIS), inflammatory processes are able to concomitantly induce both beneficial and detrimental effects. In this narrative review, we updated evidence on the inflammatory pathways and mediators that are investigated as promising therapeutic targets. We searched for papers on PubMed and MEDLINE up to August 2016. The terms searched alone or in combination were: ischemic stroke, inflammation, oxidative stress, ischemia reperfusion, innate immunity, adaptive immunity, autoimmunity. Inflammation in AIS is characterized by a storm of cytokines, chemokines, and Damage-Associated Molecular Patterns (DAMPs) released by several cells contributing to exacerbate the tissue injury both in the acute and reparative phases. Interestingly, many biomarkers have been studied, but none of these reflected the complexity of systemic immune response. Reperfusion therapies showed a good efficacy in the recovery after an AIS. New therapies appear promising both in pre-clinical and clinical studies, but still need more detailed studies to be translated in the ordinary clinical practice. In spite of clinical progresses, no beneficial long-term interventions targeting inflammation are currently available. Our knowledge about cells, biomarkers, and inflammatory markers is growing and is hoped to better evaluate the impact of new treatments, such as monoclonal antibodies and cell-based therapies.

Update on the effects of treatment with recombinant tissue-type plasminogen activator (rt-PA) in acute ischemic stroke

INTRODUCTION

Acute ischemic stroke (AIS) represents a major cause of death and disability all over the world. The recommended therapy aims at dissolving the clot to re-establish quickly the blood flow to the brain and reduce neuronal injury. Intravenous administration of recombinant tissue-type plasminogen activator (rt-PA) is clinically used with this goal.

AREAS COVERED

A description of beneficial and detrimental effects of rt-PA treatment is addressed. An overview of new therapies against AIS, such as new thrombolytics, sonolysis and sonothrombolysis, endovascular procedures, and association therapies is provided. Updates on the pathophysiological process leading to intracranial hemorrhage (ICH) is also discussed.

EXPERT OPINION

rt-PA treatment in AIS patients is beneficial to recovery outcomes. To weaken risks and improve benefits, it might be relevant to consider: i) a definitive identification of risk factors for symptomatic ICH; ii). a better organization of the health care system to reduce time-to-treatment and enhance discharge management. The pharmacological improvement of new thrombolytic drugs (such as tenecteplase and desmoteplase) targeting harmful and maximally exploiting beneficial effects might further reduce mortality and disability in AIS.