Relationship between plasma metalloproteinase-9 levels and volume and severity of infarct in patients with acute ischemic stroke

Blood-based protein biomarkers during the acute ischemic stroke treatment window: a systematic review

Background

Rapid and accurate acute ischemic stroke (AIS) diagnosis is needed to expedite emergent thrombolytic and mechanical thrombectomy treatment. Changes in blood-based protein biomarkers during the first 24 h of AIS, the time window for treatment, could complement imaging techniques and facilitate rapid diagnosis and treatment.

Methods

We performed a systematic review according to PRISMA guidelines. MEDLINE, EMBASE, Cochrane Library, and Web of Science databases were searched for eligible studies comparing levels of blood-based protein biomarkers in AIS patients with levels in healthy controls and stroke mimics. Protein biomarkers from the following pathophysiological categories were included: neurovascular inflammation (MMP-9, TNF-alpha), endothelial integrity (VCAM-1, ICAM-1), cell migration (E-Selectin, P-Selectin, L-Selectin), markers of glial and neuronal origin (GFAP, S100, S100B, NSE), and cardiac dysfunction (BNP, NT-proBNP). The literature search was limited to English-language publications before November 7th, 2023.

Results

A total of 61 studies from 20 different countries were identified, which included in total, 4,644 AIS patients, 2,242 stroke mimics, and 2,777 controls. Studies investigating TNF-alpha, MMP-9, VCAM-1, ICAM-1, E-Selectin, L-Selectin, GFAP, NSE, and S100B showed pronounced methodological heterogeneity, making between-study comparisons difficult. However, in 80% of NT-proBNP and BNP studies, and all P-selectin studies, higher biomarker levels were observed in AIS patients compared to healthy controls and/or patients with stroke mimics.

Conclusion

None of the biomarkers included showed sufficient evidence for additional diagnostic benefit for AIS. Comprehensive standardized global multicenter studies are needed to (1) permit comparability, (2) enable valid statements about protein-based biomarkers, and (3) reflect real-world scenarios.

Exploratory factor analysis yields grouping of brain injury biomarkers significantly associated with outcomes in neonatal and pediatric ECMO

In this two-center prospective cohort study of children on ECMO, we assessed a panel of plasma brain injury biomarkers using exploratory factor analysis (EFA) to evaluate their interplay and association with outcomes. Biomarker concentrations were measured daily for the first 3 days of ECMO support in 95 participants. Unfavorable composite outcome was defined as in-hospital mortality or discharge Pediatric Cerebral Performance Category > 2 with decline ≥ 1 point from baseline. EFA grouped 11 biomarkers into three factors. Factor 1 comprised markers of cellular brain injury (NSE, BDNF, GFAP, S100β, MCP1, VILIP-1, neurogranin); Factor 2 comprised markers related to vascular processes (vWF, PDGFRβ, NPTX1); and Factor 3 comprised the BDNF/MMP-9 cellular pathway. Multivariable logistic models demonstrated that higher Factor 1 and 2 scores were associated with higher odds of unfavorable outcome (adjusted OR 2.88 [1.61, 5.66] and 1.89 [1.12, 3.43], respectively). Conversely, higher Factor 3 scores were associated with lower odds of unfavorable outcome (adjusted OR 0.54 [0.31, 0.88]), which is biologically plausible given the role of BDNF in neuroplasticity. Application of EFA on plasma brain injury biomarkers in children on ECMO yielded grouping of biomarkers into three factors that were significantly associated with unfavorable outcome, suggesting future potential as prognostic instruments.

Soluble Biomarkers of Cerebrovascular Pathologies

Vascular contributions to cognitive impairment and dementia (VCID) is an all-encompassing term that describes cognitive impairment due to cerebrovascular origins. With the advancement of imaging and pathological studies, we now understand that VCID is often comorbid with Alzheimer disease. While researchers in the Alzheimer disease field have been working for years to establish and test blood-based biomarkers for Alzheimer disease diagnosis, prognosis, clinical therapy discovery, and early detection, blood-based biomarkers for VCID are in their infancy and also face challenges. VCID is heterogeneous, comprising many different pathological entities (ischemic, or hemorrhagic), and spatial and temporal differences (acute or chronic). This review highlights pathways that are aiding the search for sensitive and specific blood-based cerebrovascular dysfunction markers, describes promising candidates, and explains ongoing initiatives to discover blood-based VCID biomarkers.

Biomarkers for prognostic functional recovery poststroke: A narrative review

Background and objective: Prediction of poststroke recovery can be expressed by prognostic biomarkers that are related to the pathophysiology of stroke at the cellular and molecular level as well as to the brain structural and functional reserve after stroke at the systems neuroscience level. This study aimed to review potential biomarkers that can predict poststroke functional recovery. Methods: A narrative review was conducted to qualitatively summarize the current evidence on biomarkers used to predict poststroke functional recovery. Results: Neurophysiological measurements and neuroimaging of the brain and a wide diversity of molecules had been used as prognostic biomarkers to predict stroke recovery. Neurophysiological studies using resting-state electroencephalography (EEG) revealed an interhemispheric asymmetry, driven by an increase in low-frequency oscillation and a decrease in high-frequency oscillation in the ipsilesional hemisphere relative to the contralesional side, which was indicative of individual recovery potential. The magnitude of somatosensory evoked potentials and event-related desynchronization elicited by movement in task-related EEG was positively associated with the quantity of recovery. Besides, transcranial magnetic stimulation (TMS) studies revealed the potential values of using motor-evoked potentials (MEP) and TMS-evoked EEG potentials from the ipsilesional motor cortex as prognostic biomarkers. Brain structures measured using magnetic resonance imaging (MRI) have been implicated in stroke outcome prediction. Specifically, the damage to the corticospinal tract (CST) and anatomical motor connections disrupted by stroke lesion predicted motor recovery. In addition, a wide variety of molecular, genetic, and epigenetic biomarkers, including hemostasis, inflammation, tissue remodeling, apoptosis, oxidative stress, infection, metabolism, brain-derived, neuroendocrine, and cardiac biomarkers, etc., were associated with poor functional outcomes after stroke. However, challenges such as mixed evidence and analytical concerns such as specificity and sensitivity have to be addressed before including molecular biomarkers in routine clinical practice. Conclusion: Potential biomarkers with prognostic values for the prediction of functional recovery after stroke have been identified; however, a multimodal approach of biomarkers for prognostic prediction has rarely been studied in the literature. Future studies may incorporate a combination of multiple biomarkers from big data and develop algorithms using data mining methods to predict the recovery potential of patients after stroke in a more precise way.

Predictive value of longitudinal changes of serum matrix metalloproteinase-9 and brain-derived neurotrophic factor in acute ischemic stroke

Background

Matrix metalloproteinase-9 (MMP-9) and brain-derived neurotrophic factor (BDNF) have documented roles in the inflammatory injury cascade of neurovascular units following ischemic brain injury. However, their dynamic changes and predictive values after acute ischemic stroke (AIS) have not been well elucidated.

Objective

To investigate the temporal profiles of serum MMP-9 and BDNF concentrations and their relationship with the prognosis in patients with AIS.

Methods

MMP-9 and BDNF levels were measured in 42 AIS patients in prospectively collected blood samples, which were taken on the first day (Day 1), the second day (Day 2), and the fifth day (Day 5) after admission. Healthy subjects (n = 40) were used as controls. The AIS patients were divided into groups of good functional prognosis (n = 24) and poor prognosis (n = 18) according to their modified Rankin Scale score at 3 months. Longitudinal analysis of MMP-9 and BDNF and their association with neurological prognosis was performed using repeated measurement ANOVA.

Results

At baseline (Day 1), the levels of serum MMP-9 and BDNF were significantly higher in the AIS group than in the normal control group (P < 0.01). Repeated measurement ANOVA showed a significant main effect and interaction of MMP-9 between good prognosis and the poor group (P < 0.05). Further simple-effect analysis showed that the MMP-9 level was significantly increased in the poor prognosis group compared with the good prognosis group at T5 (P < 0.05). There were no significant time-dependent or the interaction effect (all P > 0.05), but a main effect (P < 0.05) for BDNF. Compared with the poor prognosis group, the simple-effect results indicated that the BDNF level of the good prognosis group was lower at Day 1, while the same was reversed for expression at Day 5 (P < 0.05).

Conclusion

MMP-9 and BDNF are closely related to the prognosis of patients with AIS in a time-dependent manner. The dynamic changes of the two biomarkers are superior to baseline levels in predicting the prognosis of AIS patients. A sustained decrease in MMP-9 and an increase in BDNF levels in AIS patients after several days of treatment implied a favourable prognosis.

Newly-identified blood biomarkers of neurological damage are correlated with infarct volume in patients with acute ischemic stroke

Our group recently performed a genome-wide informatic analysis that highlighted eight brain-enriched proteins with strong potential to serve as blood biomarkers of neurological injury (GFAP, MBP, β-synuclein, OPALIN, MT-3, SNAP-25, KIF5A, MOBP), including six that have yet to be widely investigated. In this study, our aim was to determine whether the circulating levels of these proteins could be used to approximate the extent of neural tissue damage in ischemic stroke. To address this aim, blood was collected from 43 ischemic stroke patients immediately upon hospital admission. The serum levels of the eight candidate proteins were measured via ELISA, infarct volume was assessed via manual tracing of neuroradiological images, and correlational analysis was performed to examine potential associative relationships. The serum levels of all eight proteins exhibited positive correlations with infarct volume, however the strongest associations were observed in a subset of four proteins known to originate from neurons specifically (MT-3, SNAP-25, KIF5A, β-synuclein). Combining the serum levels of these neuron-originating proteins using principal components analysis produced a single composite value that was more strongly correlated with infarct volume than the levels of any single protein considered in isolation (r = 0.48, p < 0.001). Measures of these proteins could potentially be used to provide a minimally invasive approximation of lesion size when advanced imaging techniques are not available, or when imaging results are inconclusive.

Hyperbaric oxygen via mediating SIRT1-induced deacetylation of HMGB1 improved cReperfusion inj/reperfusion injury

Ischemic stroke leads to severe neurological dysfunction in adults. Hyperbaric oxygen (HBO) induces tolerance to cReperfusion inj/reperfusion (I/R) injury. Therefore, our aims were to investigate whether SIRT1 participates in regulatingin the neuro-protective effect of HBO in a cerebral I/R model and its mechanism. Mice N2a cells were used to construct an oxygen deprivation/reperfusion (OGD/R) model to simulate in vitro brain I/R injury and to evaluate the role of HBO in OGD/R stimulated cells. Cell proliferation was detected using MTT, and apoptosis was determined by flow cytometry. ELISA was used to measure the concentration of TNF-α, IL-1β and IL-6 related inflammatory factors. RT-qPCR and western blot assays were performed to test the expression of SIRT1. Immunoprecipitation was used to detect acetylation of HMGB1. Expression of SIRT1 was obviously reduced after OGD/R treatment in N2a cells, while SIRT1 was obviously enhanced in HBO treated cells. Moreover, knockdown of SIRT1 induced neuro-inflammation damage in cells and HBO effectively improved the inflammatory response in OGD/R treated cells by affecting SIRT1 levels. Furthermore, HBO induced the deacetylation of HMGB1 via regulating SIRT1. Interestingly, HBO via regulating the SIRT1-induced HMGB1 deacetylation and suppressing MMP-9 improved ischemic brain injury. HBO regulated ischemic brain injury via regulation of SIRT1-induced HMGB1 deacetylation, making it a potential treatment for ischemic brain injury treatment.

Blood-Based Biomarkers: A Forgotten Friend of Hyperacute Ischemic Stroke

Ischemic stroke (IS) is the second leading cause of death worldwide. Multimodal neuroimaging techniques that have significantly facilitated the diagnosis of hyperacute IS are not widely used in underdeveloped areas and community hospitals owing to drawbacks such as high cost and lack of trained operators. Moreover, these methods do not have sufficient resolution to detect changes in the brain at the cellular and molecular levels after IS onset. In contrast, blood-based biomarkers can reflect molecular and biochemical alterations in both normal and pathophysiologic processes including angiogenesis, metabolism, inflammation, oxidative stress, coagulation, thrombosis, glial activation, and neuronal and vascular injury, and can thus provide information complementary to findings from routine examinations and neuroimaging that is useful for diagnosis. In this review, we summarize the current state of knowledge on blood-based biomarkers of hyperacute IS including those associated with neuronal injury, glial activation, inflammation and oxidative stress, vascular injury and angiogenesis, coagulation and thrombosis, and metabolism as well as genetic and genomic biomarkers. Meanwhile, the blood sampling time of the biomarkers which are cited and summarized in the review is within 6 h after the onset of IS. Additionally, we also discuss the diagnostic and prognostic value of blood-based biomarkers in stroke patients, and future directions for their clinical application and development.

Scalable Bio Marker Combinations for Early Stroke Diagnosis: A Systematic Review

Background: Acute stroke treatment is a time-critical process in which every minute counts. Laboratory biomarkers are needed to aid clinical decisions in the diagnosis. Although imaging is critical for this process, these biomarkers may provide additional information to distinguish actual stroke from its mimics and monitor patient condition and the effect of potential neuroprotective strategies. For such biomarkers to be effectively scalable to public health in any economic setting, these must be cost-effective and non-invasive. We hypothesized that blood-based combinations (panels) of proteins might be the key to this approach and explored this possibility through a systematic review. Methods: We followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines for systematic review. Initially, the broader search for biomarkers for early stroke diagnosis yielded 704 hits, and five were added manually. We then narrowed the search to combinations (panels) of the protein markers obtained from the blood. Results: Twelve articles dealing with blood-based panels of protein biomarkers for stroke were included in the systematic review. We observed that NR2 peptide (antibody against the NR2 fragment) and glial fibrillary acidic protein (GFAP) are brain-specific markers related to stroke. Von Willebrand factor (vWF), matrix metalloproteinase 9 (MMP-9), and S100β have been widely used as biomarkers, whereas others such as the ischemia-modified albumin (IMA) index, antithrombin III (AT-III), and fibrinogen have not been evaluated in combination. We herein propose the following new combination of biomarkers for future validation: panel 1 (NR2 + GFAP + MMP-9 + vWF + S100β), panel 2 (NR2 + GFAP + MMP-9 + vWF + IMA index), and panel 3 (NR2 + GFAP + AT-III + fibrinogen). Conclusions: More research is needed to validate, identify, and introduce these panels of biomarkers into medical practice for stroke recurrence and diagnosis in a scalable manner. The evidence indicates that the most promising approach is to combine different blood-based proteins to provide diagnostic precision for health interventions. Through our systematic review, we suggest three novel biomarker panels based on the results in the literature and an interpretation based on stroke pathophysiology.

Association between serum matrix metalloproteinase-9 and poor prognosis in acute ischemic stroke patients: The role of dyslipidemia

BACKGROUND AND AIMS

Whether the prognostic value of matrix metalloproteinase-9 (MMP-9) is modified by patients' dyslipidemia status is unknown. The aim of present study was to evaluate the prognostic effect of MMP-9 among ischemic stroke patients stratified by dyslipidemia status.

METHODS AND RESULTS

MMP-9 levels were measured for 2977 acute ischemic stroke patients from 26 participating hospitals across China, and data of clinical outcomes within one year after ischemic stroke was collected. The primary outcome was a composite outcome of major disability and death at one year after stroke onset, and secondary outcomes were major disability, death, vascular events and recurrent stroke. The association between MMP-9 and primary outcome was appreciably modified by dyslipidemia status (P_interaction = 0.048). After multivariate adjustment, increased MMP-9 level was associated with increased risk of primary outcome at one year after ischemic stroke in the patients with dyslipidemia (odds ratio, 1.34; 95% confidence interval, 1.06-1.79), but not in those without dyslipidemia (odds ratio, 1.23; 95% confidence interval, 0.90-1.68). Increased MMP-9 was also significantly associated with major disability, death and vascular events in the patients with dyslipidemia but not in those without dyslipidemia (P for interaction < 0.05 for all).

CONCLUSION

Increased MMP-9 was associated with poor prognosis within one-year after stroke only in patients with dyslipidemia, suggesting that the prognostic value of MMP-9 be modified by dyslipidemia status of ischemic stroke patients. Further prospective study from other populations and randomized clinical trials are needed to verify our findings and clarify the potential mechanisms.

Dynamic change of MMP-9 in diabetic stroke visualized by optical imaging and treated with CD28 superagonist

By utilizing NIRF imaging, diabetic stroke mice were visualized with a trend of higher levels of MMP-9 than wild-type mice. CD28 SA down-regulated the expression of MMP-9 and represents a potential treatment to diabetic stroke.

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.

Influence of the Matrix Metalloproteinase 9 Geners3918242 Polymorphism on Development of Ischemic Stroke: A Meta-analysis

BACKGROUND

The association between matrix metalloproteinase 9 (MMP-9) gene -1562C/T (rs3918242) polymorphism and the susceptibility of ischemic stroke (IS) has been investigated. However, results were ambiguous and inconsistent. Therefore, we performed this study to better assess the potential relationship between rs3918242 polymorphism and susceptibility risk of IS.

METHODS

We included case-control studies concerning the relationship between the rs3918242 polymorphism and IS, and odds ratios with corresponding 95% confidence intervals were used to describe the associations. Furthermore, meta-regression analyses, heterogeneity, cumulative analyses, sensitivity analyses, and publication bias were examined.

RESULTS

A total of 19 studies were included for analysis. Significant associations with the risk of IS were detected for the rs3918242 polymorphism in overall population, Asians, and whites. When available data were stratified by gender, we found a significant correlation with the risk of IS in both males and females. Further subgroup analysis by the subtypes of IS showed that the rs3918242 polymorphism was significantly correlated with the risk of patients with large artery atherosclerosis. When stratified by age, we found that the rs3918242 polymorphism was significantly correlated with the risk of IS in patients both aged ≥65 years and >65 years. Both the diabetes and the nondiabetes subgroups reached significant results, and in an analysis stratified by smoking status, an increased risk of IS was associated with smoking.

CONCLUSIONS

The rs3918242 polymorphism may be a susceptible predictor of susceptibility of IS. Further large-scale studies are needed to verify the results of our findings.

Association between Increased Matrix Metalloproteinase-9 (MMP-9) Levels with Hyperglycaemia Incidence in Acute Ischemic Stroke Patients

BACKGROUND:

Hyperglycemia is common in acute stroke patients. Hyperglycemia can induce the production of reactive oxygen species, causing increased activity of matrix metalloproteinase-9 (MMP-9).

AIM:

This study aimed to determine an association between the increased levels of MMP-9 and the incidence of hyperglycemia in acute ischemic stroke patients.

METHODS:

This is a case-control study. Acute ischemic stroke patients admitted to the Stroke Unit of a reference hospital in Yogyakarta, Indonesia was divided into the hyperglycemic and non-hyperglycemic group. Demographic and clinical characteristics of each subject were recorded, and blood levels of MMP-9 were measured. Seventy-one patients were recruited, 40 subjects in the hyperglycemic group and 31 subjects in the non-hyperglycemic group.

RESULTS:

The median levels of blood MMP-9 level in the hyperglycemic and non-hyperglycemic group were 974.37 and 748.48 ng/mL, respectively, and the difference was statistically not significant (95% CI, 191.24-2849.53; p = 0.07). When the calculated cut-off point of 600.99 ng/mL was used, the proportion of patients with higher MMP-9 levels was significantly more in the hyperglycemic group compared with the ones in the non-hyperglycemic group (82.5% and 54.8%, respectively; OR = 3.88; p = 0.011).

CONCLUSION:

We concluded that the proportion of patients with MMP-9 level >600.99 ng/mL was significantly higher in acute ischemic stroke patients with hyperglycemia.

Roles of Specialized Pro-Resolving Lipid Mediators in Cerebral Ischemia Reperfusion Injury

Ischemic stroke contributes to ~80% of all stroke cases. Recanalization with thrombolysis or endovascular thrombectomy are currently critical therapeutic strategies for rebuilding the blood supply following ischemic stroke. However, recanalization is often accompanied by cerebral ischemia reperfusion injury that is mediated by oxidative stress and inflammation. Resolution of inflammation belongs to the end stage of inflammation where inflammation is terminated and the repair of damaged tissue is started. Resolution of inflammation is mediated by a group of newly discovered lipid mediators called specialized pro-resolving lipid mediators (SPMs). Accumulating evidence suggests that SPMs decrease leukocyte infiltration, enhance efferocytosis, reduce local neuronal injury, and decrease both oxidative stress and the production of inflammatory cytokines in various in vitro and in vivo models of ischemic stroke. In this review, we summarize the mechanisms of reperfusion injury and the various roles of SPMs in stroke therapy.

Blood biomarkers in ischemic stroke: Role of biomarkers in differentiation of clinical phenotype

Stroke is the major cause of death and disability worldwide and ischemic stroke contributes 80% among them. Although limited number of patients display hemorrhagic stroke (HS), the disability and death rate are higher in HS. Several studies have been reported on identification of suitable markers for diagnosis of stroke, but none of them holds true worldwide. These observations direct toward identification of population-specific biomarker of stroke. In this study, we screened various blood biomarkers in a large cohort of well-characterized Chinese stroke patients and healthy controls. A total of 308 stroke patients including 262 acute ischemic stroke (AIS) patients and 42 HS patients were enrolled in the study and blood samples were collected within 6–24 h of stroke onset. In addition, 46 stroke mimic subjects were included for comparison of blood markers with stroke patients. Furthermore, healthy controls (n = 200) and patient controls (n = 125) from similar ethnic group were enrolled in the study. Biomarkers (S100 calcium-binding protein B (S100B), C-reactive protein (CRP), interleukin 6 (IL-6), plasminogen activator inhibitor-1 (PAI-1), matrix metallopeptidase 9 (MMP-9), P-selectin, intercellular adhesion molecule 1 (ICAM-1), tumor necrosis factor α (TNF-α), low-density lipoprotein (LDL) cholesterol, interleukin 10 (IL-10), nitric oxide (NO), and glial fibrillary acidic protein (GFAP)) were quantified by ELISA. Blood levels of S100B, CRP, IL-6, PAI-1, MMP-9, P-selectin, ICAM-1, and TNF-α were significantly higher in AIS and HS patients compared to healthy controls, patient controls, and stroke mimic patients. Receiver operating characteristic (ROC) curve analysis revealed CRP, IL-6, PAI-1, P-selectin, and TNF-α as possible biomarkers for AIS patients, and HS patients can be diagnosed based on S100B, IL-6, PAI-1, MMP-9, and TNF-α. Interestingly, significant area under ROC curves were observed for plasma S100B and CRP for differentiating AIS from HS. The results of this study validated certain blood parameters used for diagnosis of AIS or HS in Chinese patients. Furthermore, S100B and CRP are promising biomarkers for differentiation of AIS from HS.

Effects of Vitamin D3 on the NADPH Oxidase and Matrix Metalloproteinase 9 in an Animal Model of Global Cerebral Ischemia

Decreased blood flow in the brain leads to a rapid increase in reactive oxygen species (ROS). NADPH oxidase (NOX) is an enzyme family that has the physiological function to produce ROS. NOX2 and NOX4 overexpression is associated with aggravated ischemic injury, while NOX2/4-deficient mice had reduced stroke size. Dysregulation of matrix metalloproteinases (MMPs) contributes to tissue damage. The active form of vitamin D3 expresses neuroprotective, immunomodulatory, and anti-inflammatory effects in the CNS. The present study examines the effects of the vitamin D3 pretreatment on the oxidative stress parameters and the expression of NOX subunits, MMP9, microglial marker Iba1, and vitamin D receptor (VDR), in the cortex and hippocampus of Mongolian gerbils subjected to ten minutes of global cerebral ischemia, followed by 24 hours of reperfusion. The ischemia/reperfusion procedure has induced oxidative stress, changes in the expression of NOX2 subunits and MMP9 in the brain, and increased MMP9 activity in the serum of experimental animals. Pretreatment with vitamin D3 was especially effective on NOX2 subunits, MMP9, and the level of malondialdehyde and superoxide anion. These results outline the significance of the NOX and MMP9 investigation in brain ischemia and the importance of adequate vitamin D supplementation in ameliorating the injury caused by I/R.

Limb remote ischemic postconditioning protects integrity of the blood-brain barrier after stroke

Integrity of the blood-brain barrier structure is essential for maintaining the internal environment of the brain. Development of cerebral infarction and brain edema is strongly associated with blood-brain barrier leakage. Therefore, studies have suggested that protecting the blood-brain barrier may be an effective method for treating acute stroke. To examine this possibility, stroke model rats were established by middle cerebral artery occlusion and reperfusion. Remote ischemic postconditioning was immediately induced by three cycles of 10-minute ischemia/10-minute reperfusion of bilateral hind limbs at the beginning of middle cerebral artery occlusion reperfusion. Neurological function of rat models was evaluated using Zea Longa’s method. Permeability of the blood-brain barrier was assessed by Evans blue leakage. Infarct volume and brain edema were evaluated using 2,3,5-triphenyltetrazolium chloride staining. Expression of matrix metalloproteinase-9 and claudin-5 mRNA was determined by real-time quantitative reverse transcription-polymerase chain reaction. Expression of matrix metalloproteinase-9 and claudin-5 protein was measured by western blot assay. The number of matrix metalloproteinase-9- and claudin-5-positive cells was analyzed using immunohistochemistry. Our results showed that remote ischemic postconditioning alleviated disruption of the blood-brain barrier, reduced infarct volume and edema, decreased expression of matrix metalloproteinase-9 mRNA and protein and the number of positive cells, increased expression of claudin-5 mRNA and protein and the number of positive cells, and remarkably improved neurological function. These findings confirm that by suppressing expression of matrix metalloproteinase-9 and claudin-5 induced by acute ischemia/reperfusion, remote ischemic postconditioning reduces blood-brain barrier injury, mitigates ischemic injury, and exerts protective effects on the brain.

Serum matrix metalloproteinase-9 levels and prognosis of acute ischemic stroke

OBJECTIVE

To examine the association between serum matrix metalloproteinases-9 (MMP-9) levels and prognosis of acute ischemic stroke.

METHODS

We measured serum MMP-9 levels in 3,186 participants (2,008 men and 1,178 women) from the China Antihypertensive Trial in Acute Ischemic Stroke (CATIS). Study outcome data on death, major disability (modified Rankin Scale score ≥3), and vascular disease were collected at 3 months after stroke onset.

RESULTS

During 3 months of follow-up, 767 participants (24.6%) experienced major disability or died. Serum MMP-9 was significantly associated with an increased risk of death and major disability after adjustment for age, sex, time from onset to randomization, current smoking, alcohol drinking, admission NIH Stroke Scale score, diastolic blood pressure, plasma glucose, white blood cell counts, use of antihypertensive medications, and history of hypertension, coronary heart disease, and diabetes mellitus. For example, 1-SD (0.32 ng/mL) higher log-MMP-9 was associated with an odds ratio (95% confidence interval) of 1.16 (1.06-1.28) for the combined outcome of death and major disability, 1.12 (1.01-1.23) for major disability, and 1.29 (1.01-1.66) for death. The addition of serum MMP-9 to conventional risk factors improved risk prediction of the combined outcome of death or major disability (net reclassification index 9.1%, p = 0.033; integrated discrimination improvement 0.4%, p = 0.004).

CONCLUSIONS

Higher serum MMP-9 levels in the acute phase of ischemic stroke were associated with increased risk of mortality and major disability, suggesting that serum MMP-9 could be an important prognostic factor for ischemic stroke.

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.

Neutrophil-To-Lymphocyte Ratio Predicts 3-Month Outcome of Acute Ischemic Stroke

Increasing evidences have demonstrated that inflammation is involved in the mechanisms of acute ischemic stroke (AIS). As an important and easy-to-measure inflammatory marker, neutrophil-to-lymphocyte ratio (NLR) shows a high association with mortality in patients with stroke in recent studies. In this study, we evaluated the prognostic role of NLR in patients with AIS. One hundred forty-three patients with AIS were enrolled. Clinical data were collected and the NLR was calculated from the admission blood work. The patients were followed up for 3 months after stroke onset. The occurrence of death and the major disability at 3 months after onset were end points in this study. Modified Rankin Scale score ≥3 was considered as poor outcome. In this study, 75 patients (52%) had poor outcome. We used binary logistic regression model to evaluate risk factor for poor outcome of AIS and found that the NLR was independently associated with the poor outcome of 3 months (P < 0.001). The optimal cutoff value for NLR as a predictor for 3-month outcome was 2.995. Therefore, in our study, high NLRs inversely predicted 3-month outcome in patients with AIS.

Matrix Metalloproteinase in Blood-Brain Barrier Breakdown in Dementia

The neurovascular unit, which consists of astrocytic end-feet, neurons, pericytes, and endothelial cells, plays a key role in maintaining brain homeostasis by forming the blood-brain barrier and carefully controlling local cerebral blood flow. When the blood-brain barrier is disrupted, blood components can leak into the brain, damage the surrounding tissue and lead to cognitive impairment. This disruption in the blood-brain barrier and subsequent impairment in cognition are common after stroke and during cerebral amyloid angiopathy and Alzheimer's disease. Matrix metalloproteinases are proteases that degrade the extracellular matrix as well as tight junctions between endothelial cells and have been implicated in blood-brain barrier breakdown in neurodegenerative diseases. This review will focus on the roles of MMP2 and MMP9 in dementia, primarily post-stroke events that lead to dementia, cerebral amyloid angiopathy, and Alzheimer's disease.

Matrix Metalloprotease 3 Exacerbates Hemorrhagic Transformation and Worsens Functional Outcomes in Hyperglycemic Stroke

BACKGROUND AND PURPOSE

Acute hyperglycemia worsens the clinical outcomes and exacerbates cerebral hemorrhage after stroke. The mediators of hemorrhagic transformation (HT) in hyperglycemic stroke are not fully understood. Matrix metalloproteinase 3 (MMP3) plays a critical role in the tissue-type plasminogen activator-induced HT. However, the role of MMP3 in exacerbating the HT and worsening the functional outcomes in hyperglycemic stroke remains unknown.

METHODS

Control/normoglycemic and hyperglycemic (blood glucose, 140-200 mg/dL) male Wistar rats were subjected to middle cerebral artery occlusion for 90 minutes and either 24 hours or 7 days reperfusion. MMP3 was inhibited pharmacologically (UK 356618, 15 mg/kg IV at reperfusion) or knocked down in the brain by shRNA lentiviral particles (injected intracerebroventricular). Neurovascular injury was assessed at 24 hours, and functional outcomes were assessed at 24 hours, day 3, and day 7. MMP3 activity was measured in brain homogenate and cerebral macrovessels. Localization of MMP3 within the neurovascular unit after hyperglycemic stroke was demonstrated by immunohistochemistry.

RESULTS

Hyperglycemia significantly increased MMP3 activity in the brain after stroke, and this was associated with exacerbated HT and worsened functional outcomes. MMP3 inhibition significantly reduced HT and improved functional outcomes.

CONCLUSIONS

MMP3 plays a critical role in mediating cerebrovascular injury in hyperglycemic stroke. Our findings point out MMP3 as a potential therapeutic target in hyperglycemic stroke.

Inflammatory and metabolic markers and short-time outcome in patients with acute ischemic stroke in relation to TOAST subtypes

The aim of this study was to evaluate the association between inflammatory and metabolic markers and short-time outcome with acute ischemic stroke subtypes. A total of 121 patients was classified according to TOAST criteria, such as large artery atherosclerosis (LAAS), lacunar infarct (LAC), cardioembolic infarct (CEI), other determined etiology (ODE), and undetermined etiology (UDE). The functional impairment was evaluated within the first eight hours of stroke and the outcome after three-month follow-up using the modified Rankin Scale. Blood samples were obtained up to 24 h of stroke. Compared with 96 controls, patients with LAAS, CEI, and LAC subtypes showed higher levels of white blood cells, high-sensitivity C-reactive protein (hsCRP), interleukin 6 (IL-6), metalloproteinase 9 (MMP-9), glucose, and iron (p < 0.05); and lower high-density lipoprotein cholesterol (HDL-C) (p < 0.0001); platelets, insulin, insulin resistance, and homocysteine were higher in LAC (p < 0.0001); ferritin was higher in LAAS (p < 0.0001); and total cholesterol (TC) was lower in LAAS and CEI (p < 0.01). When stroke subtypes were compared, insulin was higher in LAAS vs. LAC and in LAC vs. CEI (p < 0.05); and TC was lower in LAAS vs. LAC (p < 0.05). Outcome and rate of mortality after three-month were higher in LAAS vs. LAC (p < 0.001 and p = 0.0391 respectively). The results underscored the important role of the inflammatory response and metabolic changes in the pathogenesis of ischemic stroke subtypes that might be considered on the initial evaluation of stroke patients to identify those that could benefit with individualized therapeutic strategies that taken into account these markers after acute ischemic event.

Matrix Metalloproteinase-9 (MMP-9) Gene Polymorphism in Stroke Patients

Matrix metalloproteinases (MMPs), endopeptidases degrading extracellular matrix, play an important role in the pathogenesis of atherosclerosis and vascular disease. The aim of this study was to evaluate the association between the C(-1562)T functional polymorphism in the MMP-9 gene and risk of stroke. We examined 322 patients with stroke and 410 controls. In the patient group, 52 % had type 2 diabetes. All subjects were genotyped for the C(-1562)T polymorphism by polymerase chain reaction and restriction analysis. A significant increase in T allele and CT + TT genotype frequencies was observed in patients compared with controls (OR 1.73, 95 % CI 1.34-2.23 and 1.89, 95 % CI 1.39-2.56, respectively). The T allele carriers were younger at the onset of stroke (63.5 ± 11.7 years) than patients with CC genotype (71 ± 14.1 years) (p = 0.0002). The comparison between patients with T2DM and without it showed that the T allele and CT + TT genotype were more frequent in T2DM patients (OR 1.48, 95 % CI 1.03-2.12 for T allele and 1.44, 95 % CI 1.93-2.24 for CT + TT genotype). In conclusion, our findings suggest that MMP-9 C(-1562)T polymorphism is significantly associated with risk of stroke in patients with and without T2DM.

Hemorrhagic Transformation after Tissue Plasminogen Activator Reperfusion Therapy for Ischemic Stroke: Mechanisms, Models, and Biomarkers

Intracerebral hemorrhagic transformation (HT) is well recognized as a common cause of hemorrhage in patients with ischemic stroke. HT after acute ischemic stroke contributes to early mortality and adversely affects functional recovery. The risk of HT is especially high when patients receive thrombolytic reperfusion therapy with tissue plasminogen activator, the only available treatment for ischemic stroke. Although many important publications address preclinical models of ischemic stroke, there are no current recommendations regarding the conduct of research aimed at understanding the mechanisms and prediction of HT. In this review, we discuss the underlying mechanisms for HT after ischemic stroke, provide an overview of the models commonly used for the study of HT, and discuss biomarkers that might be used for the early detection of this challenging clinical problem.

Downregulation of serum brain specific microRNA is associated with inflammation and infarct volume in acute ischemic stroke

Cerebral ischemic injury activates a robust inflammatory response, exacerbating neurological deficit. Several brain specific microRNA (miRNA) molecules have been reported to mediate functioning of the immune system, referred to as NeurimmiR. We aimed to explore possible associations between serum miRNA levels and stroke severity and their involvement in the regulation of inflammatory responses after stroke. Blood samples were obtained from 31 patients with acute ischemic stroke and 11 healthy controls. We evaluated infarct volume using diffusion weighted imaging and neurological deficit using the National Institutes of Health Stroke Scale. Serum levels of three NeurimmiR, miR-124, miR-9 and miR-219 were detected by real-time polymerase chain reaction and serum levels of metalloproteinase-9 (MMP-9), a proinflammation marker in brain injury, were examined by enzyme-linked immunosorbent assay. We found that serum miR-124 was significantly decreased within 24 hours after stroke onset and serum miR-9 was decreased in patients with larger stroke. There were no significant changes in serum miR-219. Both serum miR-124 and miR-9 levels within 24 hours were negatively correlated with infarct volume and plasma high-sensitivity C-reactive protein levels. All three NeurimmiR negatively correlated with MMP-9 levels. Our preliminary findings indicate that serum miR-124, miR-9 and miR-219 are suppressed in acute ischemic stroke thus facilitating neuroinflammation and brain injury.

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in amyotrophic lateral sclerosis (ALS)

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases, responsible for the integrity of the basement membrane (BM) via degradation of extracellular matrix and BM components. These enzymes are presented in central and peripheral nervous system. They are considered to be involved in the pathogenesis of several neurological diseases, including amyotrophic lateral sclerosis (ALS). ALS is a motor neuron disease, leading to muscle atrophy, paralysis and death within 3–5 years from diagnosis. Currently, there is no treatment that can substantially prolong life of ALS patients. Despite the fact that MMPs are not specific for ALS, there is also strong evidence that these enzymes are involved in the pathology of ALS. MMPs are able to exert direct neurotoxic effects, or may cause cell death by degrading matrix proteins. The objective of this paper is to provide an updated and comprehensive review concerning the role of MMPs and their tissue inhibitors (TIMPs) in the pathology of ALS with an emphasis on the significance of MMP-2 and MMP-9 as well as their tissue inhibitors as potential biomarkers of ALS. Numerous hypotheses have been proposed regarding the role of selected MMPs and TIMPs in ALS pathogenesis. Moreover, selective MMPs’ inhibitors might be potential targets for therapeutic strategies for patients with ALS. However, future investigations are necessary before some of those non-specific for ALS enzymes could finally be used as biomarkers of this disease.

Hemorrhagic transformation after ischemic stroke in animals and humans

Hemorrhagic transformation (HT) is a common complication of ischemic stroke that is exacerbated by thrombolytic therapy. Methods to better prevent, predict, and treat HT are needed. In this review, we summarize studies of HT in both animals and humans. We propose that early HT (<18 to 24 hours after stroke onset) relates to leukocyte-derived matrix metalloproteinase-9 (MMP-9) and brain-derived MMP-2 that damage the neurovascular unit and promote blood-brain barrier (BBB) disruption. This contrasts to delayed HT (>18 to 24 hours after stroke) that relates to ischemia activation of brain proteases (MMP-2, MMP-3, MMP-9, and endogenous tissue plasminogen activator), neuroinflammation, and factors that promote vascular remodeling (vascular endothelial growth factor and high-moblity-group-box-1). Processes that mediate BBB repair and reduce HT risk are discussed, including transforming growth factor beta signaling in monocytes, Src kinase signaling, MMP inhibitors, and inhibitors of reactive oxygen species. Finally, clinical features associated with HT in patients with stroke are reviewed, including approaches to predict HT by clinical factors, brain imaging, and blood biomarkers. Though remarkable advances in our understanding of HT have been made, additional efforts are needed to translate these discoveries to the clinic and reduce the impact of HT on patients with ischemic stroke.

Investigating the role of perlecan domain V in post-ischemic cerebral angiogenesis

Cerebral angiogenesis is an important process for physiological events such as brain development, but it also occurs in pathological conditions such as stroke. Defined as the generation of new blood vessels from preexisting vasculature, angiogenesis after ischemic stroke is important to limit the subsequent neuronal injury and death, as well as contribute to neurorepair. However, current therapies for ischemic stroke are largely focused on reestablishing uninterrupted blood flow, an important but inherently risky proposition. Furthermore, these therapies can have limited efficacy due to narrow therapeutic windows, and in the case of mechanical clot removal, are invasive procedures. Therefore, better stroke therapies are needed. Since the brain possesses mechanisms, including angiogenesis, to attempt self-repair after injury, it may prove beneficial to look at how such mechanisms are regulated to identify potential targets for new and improved stroke therapies. Perlecan domain V (DV), an endogenous extracellular matrix protein fragment, may represent one such therapeutic target. Key to its appeal is that perlecan DV is endogenously and persistently generated in the brain after stroke and has significant angio-modulatory properties. These, and other properties, have been therapeutically manipulated to improve experimental stroke outcomes, suggesting that DV could represent a promising new stroke therapy. Here we discuss a novel approach to studying DV-mediated angiogenesis in vitro using a coculture model.

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in the tumors of central nervous system (CNS)

Malignant neoplasms of the central nervous system (CNS) account for about 1.3 % of all tumors and 2.2 % of all cancer-related deaths. CNS tumors consist of heterogeneous group of neoplasms, including different variants of primary brain tumors and metastatic neoplasms. Advanced imaging techniques improved the neuroradiological diagnostic accuracy, although these methods are not specific enough for differentiation of CNS tumors, thus new approaches of patients' diagnosis are critically needed. The best solution for the diagnosis of patients with CNS tumors could be easily available biomarkers, which could be useful for the management of CNS neoplasms. Biomarkers should facilitate the diagnosis, monitor of treatment response and assess the prognosis of patients' survival. Currently, except for rare germ cell tumors, there is a lack of knowledge on biochemical markers for CNS neoplasms. Therefore, in this paper we summarized and referred a number of comprehensive reviews concerning the role of matrix metalloproteinases (MMPs) and their tissue inhibitors in tumor progression, including CNS neoplasms as well as described the general biochemistry of MMPs and their tissue inhibitors. Moreover, we presented the wide variety of previous findings, where authors suggested the significance of selected MMPs and their tissue inhibitors as potential biomarkers of human tumors, including CNS tumors. However, future investigations are needed to be performed before some of these enzymes could finally be used as biomarkers of specific types of CNS neoplasms.

Matrix metalloproteinases and blood-brain barrier disruption in acute ischemic stroke

Ischemic stroke continues to be one of the most challenging diseases in translational neurology. Tissue plasminogen activator (tPA) remains the only approved treatment for acute ischemic stroke, but its use is limited to the first hours after stroke onset due to an increased risk of hemorrhagic transformation over time resulting in enhanced brain injury. In this review we discuss the role of matrix metalloproteinases (MMPs) in blood-brain barrier (BBB) disruption as a consequence of ischemic stroke. MMP-9 in particular appears to play an important role in tPA-associated hemorrhagic complications. Reactive oxygen species can enhance the effects of tPA on MMP activation through the loss of caveolin-1 (cav-1), a protein encoded in the cav-1 gene that serves as a critical determinant of BBB permeability. This review provides an overview of MMPs' role in BBB breakdown during acute ischemic stroke. The possible role of MMPs in combination treatment of acute ischemic stroke is also examined.