Influence of hyperglycemia on oxidative stress and matrix metalloproteinase-9 activation after focal cerebral ischemia/reperfusion in rats: relation to blood-brain barrier dysfunction

The cerebroprotection and prospects of FNDC5/irisin in stroke

Stroke, the leading cause of disability and cognitive impairment, is also the second leading cause of death worldwide. The drugs with multi-targeted brain cytoprotective effects are increasingly being advocated for the treatment of stroke. Irisin, a newly discovered myokine produced by cleavage of fibronectin type III domain 5, has been shown to regulate glucose metabolism, mitochondrial energy, and fat browning. A large amount of evidence indicated that irisin could exert anti-inflammatory, anti-apoptotic, and antioxidant properties in a variety of diseases such as myocardial infarction, inflammatory bowel disease, lung injury, and kidney or liver disease. Studies have found that irisin is widely distributed in multiple brain regions and also plays an important regulatory role in the central nervous system. The most common cause of a stroke is a sudden blockage of an artery (ischemic stroke), and in some circumstances, a blood vessel rupture can also result in a stroke (hemorrhagic stroke). After a stroke, complicated pathophysiological processes lead to serious brain injury and neurological dysfunction. According to recent investigations, irisin may protect elements of the neurovascular unit by acting on multiple pathological processes in stroke. This review aims to outline the currently recognized effects of irisin on stroke and propose possible directions for future research.

Stress hyperglycemia exacerbates inflammatory brain injury after stroke

Post-stroke hyperglycemia occurs in 30% - 60% of ischemic stroke patients as part of the systemic stress response, but neither clinical evidence nor pre-clinical studies indicate whether post-stroke hyperglycemia affects stroke outcome. Here we investigated this issue using a mouse model of permanent ischemia. Mice were maintained either normoglycemic or hyperglycemic during the interval of 17 - 48 hours after ischemia onset. Post-stroke hyperglycemia was found to increase infarct volume, blood-brain barrier disruption, and hemorrhage formation, and to impair motor recovery. Post-stroke hyperglycemia also increased superoxide formation by peri-infarct microglia/macrophages. In contrast, post-stroke hyperglycemia did not increase superoxide formation or exacerbate motor impairment in p47 phox-/- mice, which cannot form an active superoxide-producing NADPH oxidase-2 complex. These results suggest that hyperglycemia occurring hours-to-days after ischemia can increase oxidative stress in peri-infarct tissues by fueling NADPH oxidase activity in reactive microglia/macrophages, and by this mechanism contribute to worsened functional outcome.

Multimodal imaging of the role of hyperglycemia following experimental subarachnoid hemorrhage

Hyperglycemia has been linked to worsening outcomes after subarachnoid hemorrhage (SAH). Nevertheless, the mechanisms involved in the pathogenesis of SAH have been scarcely evaluated so far. The role of hyperglycemia was assessed in an experimental model of SAH by T2 weighted, dynamic contrast-enhanced magnetic resonance imaging (T2W and DCE-MRI), [18F]BR-351 PET imaging and immunohistochemistry. Measures included the volume of bleeding, the extent of cerebral infarction and brain edema, blood brain barrier disruption (BBBd), neutrophil infiltration and matrix metalloprotease (MMP) activation. The neurofunctional outcome, neurodegeneration and myelinization were also investigated. The induction of hyperglycemia increased mortality, the size of the ischemic lesion, brain edema, neurodegeneration and worsened neurological outcome during the first 3 days after SAH in rats. In addition, these results show for the first time the exacerbating effect of hyperglycemia on in vivo MMP activation, Intercellular Adhesion Molecule 1 (ICAM-1) expression and neutrophil infiltration together with increased BBBd, bleeding volume and fibrinogen accumulation at days 1 and 3 after SAH. Notably, these data provide valuable insight into the detrimental effect of hyperglycemia on early BBB damage mediated by neutrophil infiltration and MMP activation that could explain the worse prognosis in SAH.

Blood glucose to predict symptomatic intracranial hemorrhage after endovascular treatment of acute ischemic stroke with large infarct core: a prospective observational study

Introduction

Symptomatic intracranial hemorrhage (sICH) is a serious complication of acute ischemic stroke (AIS) after endovascular treatment (EVT). Limited data exist regarding predictors and clinical implications of sICH after EVT, underscoring the significance of identifying risk factors to enhance prevention strategies. Therefore, the main objective of this study was to evaluate the incidence of sICH and identify its predictors after EVT in patients with large infarct core-AIS in the pre-circulation stage.

Methods

Using data from the EVT for the Pre-circulation Large Infarct Core-AIS Study, we enrolled patients who were treated with EVT from the Prospective Multicenter Cohort Study of Early Treatment in Acute Stroke (MAGIC) registry. Baseline demographics, medical history, vascular risk factors, blood pressure, stroke severity, radiographic features, and EVT details were collected. The patients were classified into three groups: without intracranial hemorrhage (ICH), with asymptomatic intracranial hemorrhage (aICH), and sICH, based upon the occurrence of sICH. The main outcomes were the occurrence of sICH according to the Heidelberg Bleeding Classification and functional condition at 90 days. Multivariate logistic regression analysis and receiver operating characteristic (ROC) curves were used to identify independent predictors of sICH after EVT.

Results

The study recruited a total of 490 patients, of whom 13.3% (n = 65) developed sICH. Patients with sICH had less favorable outcomes than those without intracranial hemorrhage (ICH) and those with aICH (13.8% vs. 43.5% vs. 32.2%, respectively; p < 0.001). The overall mortality was 41.8% (n = 205) at 90 days post-EVT. The univariate analysis revealed significant differences among the three groups in terms of blood glucose levels at admission, probability of favorable outcomes, incidence of brain herniation, and 90-day mortality. The multifactorial logistic regression analysis revealed that the blood glucose level at admission [odds ratio (OR) 1.169, p < 0.001, confidence interval (CI) 1.076-1.269] was an independent predictor of sICH. A blood glucose level of 6.95 mmol/L at admission was the best predictor of sICH, with an area under the ROC curve (AUC) of 0.685 (95% CI: 0.616-0.754).

Discussion

The study findings demonstrated that the probability of sICH after EVT was 13.3% in patients with pre-circulation large infarct core-AIS, and sICH increased the risk of an unfavorable prognosis. Higher blood glucose levels at admission were associated with sICH after EVT in patients with pre-circulation large infarct core AIS. These findings underscore the importance of early management strategies to mitigate this risk.

Dexmedetomidine alleviates blood-brain barrier disruption in rats after cerebral ischemia-reperfusion by suppressing JNK and p38 MAPK signaling

Dexmedetomidine displays multiple mechanisms of neuroprotection in ameliorating ischemic brain injury. In this study, we explored the beneficial effects of dexmedetomidine on blood-brain barrier (BBB) integrity and neuroinflammation in cerebral ischemia/reperfusion injury. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) for 1.5 h and reperfusion for 24 h to establish a rat model of cerebral ischemia/reperfusion injury. Dexmedetomidine (9 􀁐g/kg) was administered to rats 30 min after MCAO through intravenous injection, and SB203580 (a p38 MAPK inhibitor, 200 􀁐g/kg) was injected intraperitoneally 30 min before MCAO. Brain damages were evaluated by 2,3,5-triphenyltetrazolium chloride staining, hematoxylin-eosin staining, Nissl staining, and brain water content assessment. BBB permeability was examined by Evans blue staining. Expression levels of claudin-5, zonula occludens-1, occludin, and matrix metalloproteinase-9 (MMP-9) as well as M1/M2 phenotypes-associated markers were assessed using immunofluorescence, RT-qPCR, Western blotting, and gelatin zymography. Enzyme-linked immunosorbent assay was used to examine inflammatory cytokine levels. We found that dexmedetomidine or SB203580 attenuated infarct volume, brain edema, BBB permeability, and neuroinflammation, and promoted M2 microglial polarization after cerebral ischemia/reperfusion injury. Increased MMP-9 activity by ischemia/reperfusion injury was inhibited by dexmedetomidine or SB203580. Dexmedetomidine inhibited the activation of the ERK, JNK, and p38 MAPK pathways. Moreover, activation of JNK or p38 MAPK reversed the protective effects of dexmedetomidine against ischemic brain injury. Overall, dexmedetomidine ameliorated brain injury by alleviating BBB permeability and promoting M2 polarization in experimental cerebral ischemia/reperfusion injury model by inhibiting the activation of JNK and p38 MAPK pathways.

Descending thoracic aortic mural ulceration is associated with postoperative spinal cord ischemia after branched endovascular aortic aneurysm repair

OBJECTIVE

Paraplegia is one of the most feared complications after thoracoabdominal aortic aneurysm repair. The purpose of this study is to determine whether aortic thrombus characteristics are associated with spinal cord ischemia (SCI) after branched endovascular aneurysm repair (BEVAR).

METHODS

From April 2011 to April 2020, 62 patients underwent elective BEVAR for thoracoabdominal aortic aneurysm and pararenal aortic aneurysms using a low-profile device and had a complete preoperative computed tomography angiography of the aorta from the sinotubular junction to the aortic bifurcation. Aortic thrombus was evaluated for thrombus thickness ≥5 mm, thrombus >2/3 of aortic circumference, and the presence of an ulcer-like thrombus. One point was assigned at each 5 mm axial image if all 3 criteria were met, resulting in a total "shaggy score" for the entire aorta. Data on demographics, procedural details, and outcomes were collected prospectively. All patients underwent a standard spinal cord protection protocol, including routine cerebrospinal fluid drainage. In July 2016, an insulin infusion protocol (IIP) was initiated to maintain postoperative blood glucose levels <120 mg/dL for 48 hours. The primary clinical end point was postoperative SCI.

RESULTS

10 (16%) patients developed postoperative SCI: 6 with transient paraparesis, 2 with persistent paraparesis, and 2 with persistent paraplegia. Patients with SCI were older, had higher shaggy scores, and were less likely to have been on an IIP. There were no significant differences in demographics, aneurysm type, or operative parameters. In a logistic multivariate regression model for SCI, age (odds ratio [OR]: 1.2 [1.1-1.4], P = .02) and shaggy score (OR: 1.2 [1.1-1.4], P = .02) were independently associated with increased risk of SCI, whereas treatment with the IIP was associated with lower risk of SCI (OR: 0.04 [0.006-0.50], P = .05). Of the individual components of the shaggy score, higher descending thoracic aortic ulcer scores were the most strongly associated with postoperative SCI (P = .009).

CONCLUSIONS

Preoperative characterization of aortic wall thrombus is an important adjunctive tool for individualized clinical decision-making and patient counseling about the risk of SCI after BEVAR.

The role of oxidative stress in blood-brain barrier disruption during ischemic stroke: Antioxidants in clinical trials

Ischemic stroke is one of the leading causes of death and disability. Occlusion and reperfusion of cerebral blood vessels (i.e., ischemia/reperfusion (I/R) injury) generates reactive oxygen species (ROS) that contribute to brain cell death and dysfunction of the blood-brain barrier (BBB) via oxidative stress. BBB disruption influences the pathogenesis of ischemic stroke by contributing to cerebral edema, hemorrhagic transformation, and extravasation of circulating neurotoxic proteins. An improved understanding of mechanisms for ROS-associated alterations in BBB function during ischemia/reperfusion (I/R) injury can lead to improved treatment paradigms for ischemic stroke. Unfortunately, progress in developing ROS targeted therapeutics that are effective for stroke treatment has been slow. Here, we review how ROS are produced in response to I/R injury, their effects on BBB integrity (i.e., tight junction protein complexes, transporters), and the utilization of antioxidant treatments in ischemic stroke clinical trials. Overall, knowledge in this area provides a strong translational framework for discovery of novel drugs for stroke and/or improved strategies to mitigate I/R injury in stroke patients.

Futile reperfusion of endovascular treatment for acute anterior circulation large vessel occlusion in the ANGEL-ACT registry

BACKGROUND

Some patients with large vessel occlusion (LVO) still cannot achieve functional independence despite successful reperfusion after endovascular treatment (EVT), named futile reperfusion. We aimed to explore the incidence and predictors of futile reperfusion of EVT for anterior circulation LVO in the Chinese population based on a nationwide prospective multicenter registry.

METHODS

We selected patients from the ANGEL-ACT (Endovascular Treatment Key Technique and Emergency Workflow Improvement of Acute Ischemic Stroke) registry. Successful reperfusion was defined as modified Treatment In Cerebral Ischemia (mTICI) 2b-3 after EVT, and functional independence was defined as 90-day modified Rankin Scale (mRS) 0-2. A multivariable regression model was performed to identify the independent predictors of futile reperfusion in anterior circulation LVO patients.

RESULTS

A total of 1158 anterior circulation LVO patients were included in our study. 600 of the 1158 patients (51.8%) suffered futile reperfusion. Age ≥69 (adjusted OR (aOR) 1.69, 95% CI 1.21 to 2.35, P=0.002), baseline National Institutes of Health Stroke Scale (NIHSS) ≥14 (aOR 2.36, 95% CI 1.71 to 3.27, P<0.001), baseline serum glucose ≥6.5 mmol/L (aOR 1.73, 95% CI 1.27 to 2.36, P=0.001), drip and ship (aOR 1.56, 95% CI 1.11 to 2.18, P=0.011), and general anesthesia (aOR 2.28, 95% CI 1.66 to 3.14, P<0.001) were associated with a high risk of futile reperfusion in the anterior LVO patients after EVT, whereas baseline Alberta Stroke Program Early CT Score (ASPECTS) ≥8 (aOR 0.65, 95% CI 0.47 to 0.91, P=0.011) and complete reperfusion (aOR 0.62, 95% CI 0.43 to 0.89, P=0.010) were associated with a low risk of futile reperfusion in the anterior LVO patients after EVT.

CONCLUSIONS

In the ANGEL-ACT registry, 51.8% of anterior circulation LVO patients suffered futile reperfusion after EVT. Age ≥69 years, baseline NIHSS ≥14, baseline serum glucose ≥6.5 mmol/L, drip and ship, general anesthesia, baseline ASPECTS <8, and incomplete reperfusion were the independent predictors of futile reperfusion.

Increased Neuron-Specific Enolase Level Predicts Symptomatic Intracranial Hemorrhage in Patients with Ischemic Stroke Treated with Endovascular Treatment

BACKGROUND

Neuron-specific enolase (NSE), which is a highly specific marker for neurons, could be a predictor for prognosis in patients with symptomatic intracranial hemorrhage (sICH) with acute ischemic stroke who are receiving endovascular treatment (EVT). This study aimed to investigate the relationship between NSE and sICH in patients with acute anterior circulation stroke undergoing EVT.

METHODS

A total of 215 consecutive patients with acute stroke treated with EVT were included. Patients with stroke and acute anterior circulation occlusion, receiving EVT treated at our hospital, were enrolled between January 2017 and August 2021. NSE level was measured on arrival at the neurology intensive care unit after EVT. The patients were divided into 2 groups according to whether sICH was present. Univariate and multivariate analyses were performed. NSE level was also incorporated into the TAG score (modified Thrombolysis in Cerebral Infarction score, Alberta Stroke Program Early CT Score, and glucose level), which was developed as a scoring system to predict sICH, and the prediction capability was compared with the TAG score alone. Causal inference was performed using the package DoWhy in Python to evaluate the causal relationship between NSE and sICH.

RESULTS

The area under the curve (AUC) value of NSE showed moderate accuracy, with an AUC value of 0.729 (95% confidence interval, 0.655-0.795; P < 0.001). The NSE cutoff value was set at 23.88 ng/mL. When the NSE level ≥23.88 ng/mL, the sensitivity was 58.33% and the specificity was 78.72% (P < 0.001). The AUC for the TAG + NSE score was 0.801 compared with an AUC of 0.632 for the TAG score (Z = 2.034; P = 0.042). A causal inference model using the DoWhy library shows a proportional relationship between NSE and the diagnosis of sICH.

CONCLUSIONS

This study is the first to show that increased NSE level is an independent predictor of sICH in patients with acute anterior circulation stroke who are undergoing endovascular treatment.

Hyperglycemia exacerbates ischemic stroke not through increased generation of hydrogen peroxide

Diabetes is one of the significant risk factors for ischemic stroke. Hyperglycemia exacerbates the pathogenesis of stroke, leading to more extensive cerebral damage and, as a result, to more severe consequences. However, the mechanism whereby the hyperglycemic status in diabetes affects biochemical processes during the development of ischemic injury is still not fully understood. In the present work, we record for the first time the real-time dynamics of H2O2 in the matrix of neuronal mitochondria in vitro in culture and in vivo in the brain tissues of rats during development of ischemic stroke under conditions of hyperglycemia and normal glucose levels. To accomplish this, we used a highly sensitive HyPer7 biosensor and a fiber-optic interface technology. We demonstrated that a high glycemic status does not affect the generation of H2O2 in the tissues of the ischemic core, while significantly exacerbating the consequences of pathogenesis. For the first time using Raman microspectroscopy approach, we have shown how a sharp increase in the blood glucose level increases the relative amount of reduced cytochromes in the mitochondrial electron transport chain in neurons under normal conditions in awake mice.

Protective effects of KLF4 on blood-brain barrier and oxidative stress after cerebral ischemia-reperfusion in rats through the Nrf2/Trx1 pathway

PURPOSE

To investigate the role of KLF4 in CI/R injury and whether Nrf2/Trx1 axis acted as a downstream pathway of KLF4 to exert the protective role in blood-brain barrier destruction after CI/R.

METHODS

The tMCAO rat model in vivo was constructed and received the intracerebroventricular injection of 5 μg/kg and 10 μg/kg rhKLF4 before operation. TTC, brain water content, neurological function, ELISA, behavioral tests, HE, TUNEL, and qRT-PCR were performed to detect the protective role of KLF4 on CIR. Double-fluorescence staining and western blot were performed to determine the localization and spatiotemporal expression in brain tissues. Furthermore, we also analyzed the effect of KLF4 on the blood-brain barrier (BBB) and related mechanisms in vivo and in vitro. Nrf2 inhibitor tretinoin was applied, which was intraperitoneally injected into CIR rat. Evans blue staining was conducted. In vitro OGD/R models of bEnd.3 cells were also established, and received KLF4 overexpressed transfection and 12.5 µM tretinoin incubation. The permeability of bEnd.3 cells was evaluated by TEER and FITC-dextran leakage. BBB-related factors and oxidative stress were also analyzed, respectively. The tubular ability of KLF4 on OGD/R bEnd3 cells was also evaluated.

RESULTS

In vivo study confirmed that KLF4 was expressed in astrocyte, and its content increased with time. KLF4 protected against brain injury caused by cerebral ischemia-reperfusion, reduced cerebral infarction area and oxidative stress levels, and promoted the recovery of behavioral ability in rats. Simultaneously, mechanism experiments confirmed that the repair effect of KLF4 on cerebral ischemia-reperfusion injury was closely related to the Nrf2/Trx1 pathway. KLF4 exerted the neuroprotective effect through upregulating Nrf2/Trx1 pathway. Consistent with in vivo animal study, in vitro study also confirmed the effect of KLF4 on the permeability of bEnd.3 cells after OGD/R injury through Nrf2/Trx1 pathway.

CONCLUSION

Collectively, KLF4 played neuroprotective role in CIR induced MCAO and OGD/R, and the beneficial effects of KLF4 was partly linked to Nrf2/Trx1 pathway.

AGE-RAGE axis culminates into multiple pathogenic processes: a central road to neurodegeneration

Advanced glycation end-products (AGEs; e.g., glyoxal, methylglyoxal or carboxymethyl-lysine) are heterogenous group of toxic compounds synthesized in the body through both exogenous and endogenous pathways. AGEs are known to covalently modify proteins bringing about loss of functional alteration in the proteins. AGEs also interact with their receptor, receptor for AGE (RAGE) and such interactions influence different biological processes including oxidative stress and apoptosis. Previously, AGE-RAGE axis has long been considered to be the maligning factor for various human diseases including, diabetes, obesity, cardiovascular, aging, etc. Recent developments have revealed the involvement of AGE-RAGE axis in different pathological consequences associated with the onset of neurodegeneration including, disruption of blood brain barrier, neuroinflammation, remodeling of extracellular matrix, dysregulation of polyol pathway and antioxidant enzymes, etc. In the present article, we attempted to describe a new avenue that AGE-RAGE axis culminates to different pathological consequences in brain and therefore, is a central instigating component to several neurodegenerative diseases (NGDs). We also invoke that specific inhibitors of TIR domains of TLR or RAGE receptors are crucial molecules for the therapeutic intervention of NGDs. Clinical perspectives have also been appropriately discussed.

Machine learning predicts the risk of hemorrhagic transformation of acute cerebral infarction and in-hospital death

BACKGROUND

The incidence of hemorrhagic transformation (HT) during thrombolysis after acute cerebral infarction (ACI) is very high. We aimed to develop a model to predict the occurrence of HT after ACI and the risk of death after HT.

METHODS

Cohort 1 is divided into HT and non-HT groups, to train the model and perform internal validation. All first laboratory test results of study subjects were used as features to be selected for machine learning, and the models built by four machine learning algorithms were compared to screen the best algorithm and model. Following that, the HT group was divided into death and non-death for subgroup analysis. Receiver operating characteristic (ROC) curves etc. to evaluate the model. ACI patients in cohort 2 for external validation.

RESULTS

In cohort 1, the HT risk prediction model HT-Lab10 built by the XgBoost algorithm performed the best with AUC_ROC=0.95 (95% CI, 0.93-0.96). Ten features were included in the model, namely B-type natriuretic peptide precursor, ultrasensitive C-reactive protein, glucose, absolute neutrophil value, myoglobin, uric acid, creatinine, Ca²⁺, Thrombin time, and carbon dioxide combining power. The model also had the ability to predict death after HT with AUC_ROC=0.85 (95% CI, 0.78-0.91). The ability of HT-Lab10 to predict the occurrence of HT as well as death after HT was validated in cohort 2.

CONCLUSIONS

The model HT-Lab10 built using the XgBoost algorithm showed excellent predictive ability in both the occurrence of HT and the risk of HT death, achieving a model with multiple uses.

The effect of acute toxicity from tributyltin on Liza haematocheila liver: Energy metabolic disturbance, oxidative stress, and apoptosis

Tributyltin (TBT), a highly toxic and persistent organic pollutant, is widely distributed in coastal waters. Liza haematocheila (L. haematocheila) is one of bony fish distributing coincident with TBT, and exposure risk of TBT to this fish is unknown. In this study, L. haematocheila was exposed to TBT of 0, 3.4, 6.8, and 17.2 μg/L for 48 h to explore hepatic response mechanism. Our results showed that Sn content in livers increased after 48 h of exposure. HSI and histological changes indicated that TBT suppressed liver development of L. haematocheila. TBT reduced ATPase activities. The increased RB in blood and the reduced TBC were measured after exposure to TBT. T-AOC and antioxidant enzymes SOD, CAT, and GPx activities were inhibited while MDA content was increased. Liver cells showed apoptosis characteristics after TBT exposure. Furthermore, transcriptome analysis of livers was performed and the results showed energy metabolism-related GO term (such as ATPase complex and ATPase dependent transmembrance transport complex), oxidative stress-related GO term (such as Celllular response to oxidative stress and Antioxidant activity), and apoptosis-related GO term (such as Regulation of cysteine-type endopeptidase activity involved in apoptosic signaling pathway). Moreover, we found six energy metabolism-related differentially expressed genes (DEGs) including three up-regulated DEGs (atnb233, cftr, and prkag2) and three down-regulated DEGs (acss1, abcd2, and smarcb1); five oxidative stress-related DEGs including one up-regulated DEG (mmp9) and four down-regulated DEG (prdx5, hsp90, hsp98, and gstf9); as well as six apoptosis-related DEGs including five up-regulated DEGs (casp8, cyc, apaf1, hccs, and dapk3) and one down-regulated DEG (bcl2l1). Our transcriptome data above further confirmed that acute stress of TBT led energy metabolic disturbance, oxidative stress, and apoptosis in L. haematocheila livers.

Anethole Pretreatment Modulates Cerebral Ischemia/Reperfusion: The Role of JNK, p38, MMP-2 and MMP-9 Pathways

Anethole (AN) is one of the major constituents of several plant oils, demonstrating plentiful pharmacological actions. Ischemic stroke is the main cause of morbidity and death worldwide, particularly since ischemic stroke therapeutic choices are inadequate and limited; thus, the development of new therapeutic options is indispensable. This study was planned to explore the preventive actions of AN in ameliorating cerebral ischemia/reperfusion-induced brain damage and BBB permeability leakage, as well as to explore anethole’s potential mechanisms of action. The proposed mechanisms included modulating JNK and p38 as well as MMP-2 and MMP-9 pathways. Sprague–Dawley male rats were randomly assigned into four groups: sham, middle cerebral artery occlusion (MCAO), AN125 + MCAO, and AN250 + MCAO. Animals in the third and fourth groups were pretreated with AN 125 or 250 mg/kg orally, respectively, for two weeks before performing middle cerebral artery occlusion (MCAO)-induced cerebral ischemic/reperfusion surgery. Animals that experienced cerebral ischemia/reperfusion exhibited amplified infarct volume, Evans blue intensity, brain water content, Fluoro-Jade B-positive cells, severe neurological deficits, and numerous histopathological alterations. MCAO animals exhibited elevated MMP-9 and MMP-2 gene expressions, enzyme activities, augmented JNK, and p38 phosphorylation. On the other hand, pretreatment with AN diminished the infarct volume, Evans blue dye intensity, brain water content, and Fluoro-Jade B-positive cells, improved the neurological score and enhanced histopathological examination. AN effectively lowered MMP-9 and MMP-2 gene expression and enzyme activities and diminished phosphorylated JNK, p38. AN decreased MDA content, amplified GSH/GSSG ratio, SOD, and CAT, decreased the serum and brain tissue homogenate inflammatory cytokines (TNF-α, IL-6, IL-1β), NF-κB, and deterred the apoptotic status. This study revealed the neuroprotective ability of AN against cerebral ischemia/reperfusion in rats. AN boosted blood–brain barrier integrity via modulating MMPs and diminished oxidative stress, inflammation, and apoptosis through the JNK/p38 pathway.

Does stress hyperglycemia in diabetic and non-diabetic acute ischemic stroke patients predict unfavorable outcomes following endovascular treatment?

BACKGROUND

Hyperglycemia in hospitalized patients is related to increased morbidity and mortality, we determine if stress hyperglycemia, as assessed by the stress hyperglycemia ratio (SHR) index, increases the risk of adverse events in diabetic and non-diabetic AIS (acute ischemic stroke) patients following EVT (endovascular treatment).

METHODS

We retrospectively analyzed data of 209 patients who achieved complete recanalization. SHR was defined as [FPG (mmol/L)/HbA1c (%)]. This study comprised 130 non-diabetic AIS patients and 79 people with diabetes, and they were categorized into three different groups based on SHR (Q1-Q3) tertiles. The primary outcome was futile recanalization, characterized as a 3-month modified Rankin scale score (mRS) of 3-6. Multivariable logistic regression analyses were utilized to calculate the relationship between stress hyperglycemia and poor outcomes.

RESULTS

Non-diabetic patients showed statistically significant differences in the proportion of 3-month all-cause mortality (14.6% for Q1, 63.0% for Q2, 74.4% for Q3, p<0.001) and futile recanalization (2.4% for Q1, 19.6% for Q2, 37.2% for Q3, p<0.001) between the three groups. After adjusting for potential confounders, we found that the highest SHR tertile remained an independent risk factor of futile recanalization (OR 18.13, 95% CI 3.38-97.38, p = 0.001) and 3-month all-cause mortality (OR 15.9, 95% CI 1.46-173.26, p = 0.023) among non-diabetic patients. As demonstrated by restricted cubic splines, the SHR reference was 1.12.

CONCLUSIONS

Severe stress hyperglycemia independently increased the odds of futile recanalization and 3-month all-cause mortality in AIS patients receiving EVT but without diabetes.

Predictors of intracranial hemorrhage after mechanical thrombectomy using a stent-retriever for anterior circulation ischemic stroke: A retrospective study

Intracranial hemorrhage (ICH) after mechanical thrombectomy (MT) is a potentially catastrophic complication. We aimed to identify predictors of hemorrhagic complications following MT using a stent-retriever (SR) for acute ischemic stroke (AIS) patients due to large vessel occlusion of anterior circulation. In consecutive AIS patients, the clinical and procedural variables were retrospectively analyzed. ICH was evaluated on computed tomography performed 24 hours following MT and dichotomized into asymptomatic ICH and symptomatic intracranial hemorrhage (SICH) depending on the presence of neurological deterioration. Using univariate and multivariate analyses, the predictors of ICH and SICH were identified. The optimal cutoff value for predicting SICH was determined by receiver operating characteristic (ROC) analysis. Among 135 patients, ICH was detected in 52 (38.5%), and 17 (12.6%) were classified as having SICH. We found that serum glucose level (odds ratio [OR] 1.016, P = .011) and number of SR passes (OR 2.607, P < .001) were significantly correlated with ICH. Independent predictors of SICH included the baseline Alberta stroke program early computed tomography score (ASPECTS) (OR 0.485, P = .042), time from stroke onset to groin puncture (OTP) (OR 1.033, P = .016), and number of SR passes (OR 2.342, P = .038). In ROC analysis, baseline ASPECTS ≤ 7, OTP > 280 minutes, and SR passes > 3 were the optimal cutoff values for predicting SICH. In conclusion, serum glucose level and SR pass serve as predictors for any form of ICH in large vessel occlusion-induced AIS patients undergoing MT. Moreover, patients with lower ASPECTS, prolonged OTP, and multiple SR passes are more vulnerable to SICH.

A review of stress-induced hyperglycaemia in the context of acute ischaemic stroke: Definition, underlying mechanisms, and the status of insulin therapy

The transient elevation of blood glucose produced following acute ischaemic stroke (AIS) has been described as stress-induced hyperglycaemia (SIH). SIH is common even in patients with AIS who have no previous diagnosis of diabetes mellitus. Elevated blood glucose levels during admission and hospitalization are strongly associated with enlarged infarct size and adverse prognosis in AIS patients. However, insulin-intensive glucose control therapy defined by admission blood glucose for SIH has not achieved the desired results, and new treatment ideas are urgently required. First, we explore the various definitions of SIH in the context of AIS and their predictive value in adverse outcomes. Then, we briefly discuss the mechanisms by which SIH arises, describing the dual effects of elevated glucose levels on the central nervous system. Finally, although preclinical studies support lowering blood glucose levels using insulin, the clinical outcomes of intensive glucose control are not promising. We discuss the reasons for this phenomenon.

Predictors of parenchymal hemorrhage after endovascular treatment in acute ischemic stroke: data from ANGEL-ACT Registry

BACKGROUND

Parenchymal hemorrhage (PH) is a troublesome complication after endovascular treatment (EVT).

OBJECTIVE

To investigate the incidence, independent predictors, and clinical impact of PH after EVT in patients with acute ischemic stroke (AIS) due to anterior circulation large vessel occlusion (LVO).

METHODS

Subjects were selected from the ANGEL-ACT Registry. PH was diagnosed according to the European Collaborative Acute Stroke Study classification. Logistic regression analyses were performed to determine the independent predictors of PH, as well as the association between PH and 90-day functional outcome assessed by modified Rankin Scale (mRS) score.

RESULTS

Of the 1227 enrolled patients, 147 (12.0%) were diagnosed with PH within 12-36 hours after EVT. On multivariable analysis, low admission Alberta Stroke Program Early CT score (ASPECTS)(adjusted OR (aOR)=1.13, 95% CI 1.02 to 1.26, p=0.020), serum glucose >7 mmol/L (aOR=1.82, 95% CI 1.16 to 2.84, p=0.009), and neutrophil-to-lymphocyte ratio (NLR; aOR=1.05, 95% CI 1.02 to 1.09, p=0.005) were associated with a high risk of PH, while underlying intracranial atherosclerotic stenosis (ICAS; aOR=0.42, 95% CI 0.22 to 0.81, p=0.009) and intracranial angioplasty/stenting (aOR=0.37, 95% CI 0.15 to 0.93, p=0.035) were associated with a low risk of PH. Furthermore, patients with PH were associated with a shift towards to worse functional outcome (mRS score 4 vs 3, adjusted common OR (acOR)=2.27, 95% CI 1.53 to 3.38, p<0.001).

CONCLUSIONS

In Chinese patients with AIS caused by anterior circulation LVO, the risk of PH was positively associated with low admission ASPECTS, serum glucose >7 mmol/L, and NLR, but negatively related to underlying ICAS and intracranial angioplasty/stenting.

TRIAL REGISTRATION NUMBER

NCT03370939.

Remote ischemic conditioning attenuates blood-brain barrier disruption after recombinant tissue plasminogen activator treatment via reducing PDGF-CC

Treatment of acute ischemic stroke with the recombinant tissue plasminogen activator (rtPA) is associated with increased blood-brain barrier (BBB) disruption and hemorrhagic transformation. Remote ischemic conditioning (RIC) has demonstrated neuroprotective effects against acute ischemic stroke. However, whether and how RIC regulates rtPA-associated BBB disruption remains unclear. Here, a rodent model of thromboembolic stroke followed by rtPA thrombolysis at different time points was performed with or without RIC. Brain infarction, neurological outcomes, BBB permeability, and intracerebral hemorrhage were assessed. The platelet-derived growth factor CC (PDGF-CC)/PDGFRα pathway in the brain tissue, PDGF-CC levels in the skeletal muscle and peripheral blood were also measured. Furthermore, impact of RIC on serum PDGF-CC levels were measured in healthy subjects and AIS patients. Our results showed that RIC substantially reduced BBB injury, intracerebral hemorrhage, cerebral infarction, and neurological deficits after stroke, even when rtPA was administrated in a delayed therapeutic time window. Mechanistically, RIC significantly decreased PDGFRα activation in ischemic brain tissue and reduced blood PDGF-CC levels, which partially resulted from PDGF-CC reduction in the skeletal muscle of RIC-applied hindlimbs and platelets. Intravenous or intraventricular recombinant PDGF-CC supplementation abolished RIC protective effects on BBB integrity. Moreover, similar changes of PDGF-CC in serum by RIC were also observed in healthy humans and acute ischemic stroke patients. Together, our study demonstrates that RIC can attenuate rtPA-aggravated BBB disruption after ischemic stroke via reducing the PDGF-CC/PDGFRα pathway and thus supports RIC as a potential approach for BBB disruption prevention or treatment following thrombolysis.

Effect of Comorbidities on the Outcome of Patients with Aneurysmal Subarachnoid Hemorrhage: A Prospective Observational Study

Background The pathophysiological changes following aneurysmal subarachnoid hemorrhage (aSAH) lead to a varied degree of neurological deficit and cognitive decline. The presence of comorbidities can contribute to the progression and course of the disease resulting in high morbidity and mortality.

Methods A total of 140 patients with aSAH, scheduled for surgical clipping or endovascular coiling were included. The patients' comorbidities were recorded. The postoperative outcome was evaluated using Glasgow Outcome Scale at 1 month following discharge. Multiple logistic regression analysis was performed to identify variables predicting poor outcome, taking into consideration those variables which were significant in univariate analysis.

Results Sixty-six percent of these patients with aSAH had associated comorbidities. In our patient cohort, we found that smoking and hypertension were associated with worse outcome (odds ratio [OR] = 4.63 [confidence interval [CI] = 1.83–11.7] and OR = 2.92 [CI = 1.41–6.01], respectively). Hypothyroidism, diabetes mellitus, coronary artery disease, and asthma did not influence the neurological outcome because of their small number.

Conclusion Presence of comorbidities like smoking and hypertension significantly worsen the outcome of these patients with aSAH.

A Simple Grading Scale for Predicting Symptomatic Intracranial Hemorrhage after Mechanical Thrombectomy

INTRODUCTION

Hemorrhagic transformation, especially symptomatic intracranial hemorrhage (sICH), is a common complication after mechanical embolectomy. This study explored a grading scale based on clinical and radiological parameters to predict sICH after mechanical embolectomy.

METHODS

Demographic and clinical data were retrospectively collected from patients with acute ischemic stroke treated with mechanical embolectomy at West China Hospital. Clinical and radiological factors associated with sICH were identified and used to develop the "STBA" grading scale. This score was then validated using data from an independent sample at the First Affiliated Hospital of Kunming Medical University.

RESULTS

We analyzed 268 patients with acute ischemic stroke who were treated with mechanical embolectomy at West China Hospital, of whom 30 (11.2%) had sICH. Patients were rated on an "STBA" score ranging from 0 to 6 based on whether systolic blood pressure was ≥145 mm Hg at admission (yes = 2 points; no = 0 points), time from acute ischemic stroke until groin puncture was ≥300 min (yes = 1; no = 0), blood glucose was ≥8.8 mmol/L (yes = 1; no = 0), and the Alberta Stroke Program Early Computed Tomography score at admission was 0-5 (2 points), 6-7 (1 point), or 8-10 (0 points). The STBA score showed good discrimination in the derivation sample (area under the receiver operating characteristic curve = 0.858) and in the validation sample (area = 0.814).

CONCLUSIONS

The STBA score may be a reliable clinical scoring system to predict sICH in acute ischemic stroke patients treated with mechanical embolectomy.

The predictors of hyperglycemia and its effects on neurological outcome in the patients with aneurysmal subarachnoid hemorrhage undergoing surgical clipping: A prospective observational study

Background:

Following intracranial aneurysm rupture, 70–90% of patients have hyperglycemia as a stressful response. Uncontrolled hyperglycemia is deleterious if not controlled well. The objectives of the study were to assess the prevalence, risk factors of hyperglycemia, and its effect on outcome in aneurysmal subarachnoid hemorrhage (aSAH) patients who underwent aneurysmal clipping.

Methods:

Following intracranial aneurysm rupture, 70–90% of patients have hyperglycemia as a stressful response. Uncontrolled hyperglycemia is deleterious if not controlled well. The objectives of the study were to assess the prevalence, risk factors of hyperglycemia, and its effect on outcome in aSAH patients who underwent aneurysmal clipping.

Results:

At admission, the prevalence of hyperglycemia and severe hyperglycemia was 31.8% and 6.8%, respectively. Perioperative hyperglycemia and severe hyperglycemia were seen in 75.7% and 27%, respectively. History of diabetes mellitus (DM), higher admission random blood sugar, and higher admission mean blood pressure were predictors of perioperative hyperglycemia (P- 0.046, 0.00, and 0.004, respectively) and severe hyperglycemia (P- 0.048, 0.00, and 0.031). In addition, female sex, prolonged duration of anesthesia, and surgery were also found to be the predictors of hyperglycemia (P- 0.025, 0.07, and 0.012). Increased ventilator, intensive care unit, and hospital days were associated with perioperative hyperglycemia and severe hyperglycemia, respectively (P ≤ 0.006/0.00, P ≤ 0.007/0.00, and P ≤ 0.038/0.00). Poor Glasgow Outcome Score at 1 and 3 months after discharge was associated with admission and perioperative hyperglycemia ([P ≤ 0.000/0.000 and P ≤ 0.000/0.000], respectively). However, no association was seen between mortality and hyperglycemia or severe hyperglycemia.

Conclusion:

A higher prevalence of hyperglycemia is present in aSAH patients. A higher incidence of perioperative hyperglycemia is associated with poor neurological outcomes. Hence, the identification of risk factors and meticulous perioperative control of hyperglycemia will help in preventing poor neurological outcomes.

Therapeutic Potential and Mechanisms of Novel Simple O-Substituted Isoflavones against Cerebral Ischemia Reperfusion

Isoflavones have been widely studied and have attracted extensive attention in fields ranging from chemotaxonomy and plant physiology to human nutrition and medicine. Isoflavones are often divided into three subgroups: simple O-substituted derivatives, prenylated derivatives, and glycosides. Simple O-substituted isoflavones and their glycosides, such as daidzein (daidzin), genistein (genistin), glycitein (glycitin), biochanin A (astroside), and formononetin (ononin), are the most common ingredients in legumes and are considered as phytoestrogens for daily dietary hormone replacement therapy due to their structural similarity to 17-β-estradiol. On the basis of the known estrogen-like potency, these above isoflavones possess multiple pharmacological activities such as antioxidant, anti-inflammatory, anticancer, anti-angiogenetic, hepatoprotective, antidiabetic, antilipidemic, anti-osteoporotic, and neuroprotective activities. However, there are very few review studies on the protective effects of these novel isoflavones and their related compounds in cerebral ischemia reperfusion. This review primarily focuses on the biosynthesis, metabolism, and neuroprotective mechanism of these aforementioned novel isoflavones in cerebral ischemia reperfusion. From these published works in in vitro and in vivo studies, simple O-substituted isoflavones could serve as promising therapeutic compounds for the prevention and treatment of cerebral ischemia reperfusion via their estrogenic receptor properties and neuron-modulatory, antioxidant, anti-inflammatory, and anti-apoptotic effects. The detailed mechanism of the protective effects of simple O-substituted isoflavones against cerebral ischemia reperfusion might be related to the PI3K/AKT/ERK/mTOR or GSK-3β pathway, eNOS/Keap1/Nrf-2/HO-1 pathway, TLRs/TIRAP/MyD88/NFκ-B pathway, and Bcl-2-regulated anti-apoptotic pathway. However, clinical trials are needed to verify their potential on cerebral ischemia reperfusion because past studies were conducted with rodents and prophylactic administration.

Identification of changed proteins by retinoic acid in cerebral ischemic damage: a proteomic study

Ischemic stroke is a severe neurodegenerative disease with a high mortality rate. Retinoic acid is a representative metabolite of vitamin A. It has many beneficial effects including anti-inflammatory, anti-apoptotic, and neuroprotective effects. The purpose of this study is to identify specific proteins that are regulated by retinoic acid in ischemic stroke. Middle cerebral artery occlusion (MCAO) was performed to induce focal cerebral ischemia. Retinoic acid (5 mg/kg) or vehicle was injected intraperitoneally into male rats for four days prior to MCAO operation. Neurobehavioral tests were performed 24 hr after MCAO and the cerebral cortex was collected for proteomic study. Retinoic acid alleviates neurobehavioral deficits and histopathological changes caused by MCAO. Furthermore, we identified various proteins that were altered by retinoic acid in MCAO damage. Among these identified proteins, adenosylhomocysteinase, isocitrate dehydrogenase [NAD+] subunit α, glycerol-3-phosphate dehydrogenase, Rab GDP dissociation inhibitor β, and apolipoprotein A1 were down-regulated in MCAO animals with vehicle treatment, whereas retinoic acid treatment alleviated these reductions. However, heat shock protein 60 was up-regulated in MCAO animals with vehicle, while retinoic acid treatment attenuated this increase. The changes in these expressions were confirmed by reverse transcription-PCR. These proteins regulate cell metabolism and mediate stress responses. Our results demonstrated that retinoic acid attenuates the neuronal damage by MCAO and regulates the various protein expressions that are involved in the survival of cells. Thus, we can suggest that retinoic acid exerts neuroprotective effects on focal cerebral ischemia by modulation of specific proteins.

Association of hyperglycemia and computed tomographic perfusion deficits in patients who underwent endovascular treatment for acute ischemic stroke caused by a proximal intracranial occlusion: A subgroup analysis of a randomized phase 3 trial (MR CLEAN)

INTRODUCTION

Hyperglycemia is highly prevalent in patients with acute ischemic stroke and is associated with increased risk of symptomatic intracranial hemorrhage, larger infarct size and unfavorable outcome. Furthermore, glucose may modify the effect of endovascular treatment (EVT) in patients with ischemic stroke. Hyperglycemia might lead to accelerated conversion of penumbra into infarct core. However, it remains uncertain whether hyperglycemia on admission is associated with the size of penumbra or infarct core in acute ischemic stroke. In this study, we aimed to assess the association between hyperglycemia and Computed Tomographic Perfusion (CTP) derived parameters in patients who underwent EVT for acute ischemic stroke.

METHODS

We used data from the MR CLEAN study (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands). Hyperglycemia was defined as admission serum glucose of >7.8 mmol/L. Dichotomized and quantiles of glucose levels were related to size of core, penumbra and core penumbra ratio. Hypoperfused area is mean transient time 45% higher than that of the contralateral hemisphere. Core is the area with cerebral blood volume of <2 mL/100 g and penumbra is the area with cerebral blood volume > 2 mL/100 g. Core-penumbra ratio is the ischemic core divided by the total volume of hypoperfused tissue (core plus penumbra) multiplied by 100. Adjustments were made for age, sex, NIHSS on admission, onset-imaging time and diabetes mellitus.

RESULTS

Hundred seventy-three patients were included. Median glucose level on admission was 6.5 mmol/L (IQR 5.8-7.5 mmol/L) and thirty-five patients (20%) were hyperglycemic. Median core volume was 33.3 mL (IQR 13.6-62.4 mL), median penumbra volume was 80.2 mL (IQR 36.3-123.5 mL) and median core-penumbra ratio was 28.5% (IQR 18.6-45.8%). Patients with hyperglycemia on admission had larger core volumes and core penumbra ratio than normoglycemic patients with a regression coefficient of 15.1 (95% confidence interval (CI), 1.8 to 28.3) and 11.5 (95% confidence interval (CI), 3.4 to 19.7) respectively.

CONCLUSION

Hyperglycemia on admission was associated with larger ischemic core volume and larger core-penumbra ratio in patients with acute ischemic stroke who underwent endovascular treatment.

Teriparatide induces angiogenesis in ischemic cerebral infarction zones of rats through AC/PKA signaling and reduces ischemia-reperfusion injury

Teriparatide is a commonly used drug indicated for the treatment of osteoporosis in postmenopausal women. Teriparatide can also upregulate Ang-1 expression through the AC/PKA signaling pathway to promote angiogenesis. At present, promoting angiogenesis is a promising but unrealized strategy for the treatment of ischemic cerebral infarction. However, there are few studies on the application of teriparatide in the treatment of cerebral infarction. We used teriparatide to treat ischemic cerebral infarction in rats and obtained three major findings. First, teriparatide can promote angiogenesis, reduce cerebral infarct size, and increase cerebral perfusion by upregulating Ang-1 expression. Second, teriparatide can promote the expression of HO1, SOD2 and inhibit the production of pro-inflammatory cytokines IL-1β, IL-6 by upregulating Nrf2 expression. Third, we further found that teriparatide can mitigate blood-brain barrier disruption and brain edema by downregulating the expressions of MMP9, Ang-2 and AQP4. Our results indicate that teriparatide is neuroprotective through multiple mechanisms of action that include promoting angiogenesis, inhibiting oxidative stress and neuroinflammation, protecting blood-brain barrier, and reducing brain edema.

Neuroserpin, a crucial regulator for axogenesis, synaptic modelling and cell-cell interactions in the pathophysiology of neurological disease

Neuroserpin is an axonally secreted serpin that is involved in regulating plasminogen and its enzyme activators, such as tissue plasminogen activator (tPA). The protein has been increasingly shown to play key roles in neuronal development, plasticity, maturation and synaptic refinement. The proteinase inhibitor may function both independently and through tPA-dependent mechanisms. Herein, we discuss the recent evidence regarding the role of neuroserpin in healthy and diseased conditions and highlight the participation of the serpin in various cellular signalling pathways. Several polymorphisms and mutations have also been identified in the protein that may affect the serpin conformation, leading to polymer formation and its intracellular accumulation. The current understanding of the involvement of neuroserpin in Alzheimer's disease, cancer, glaucoma, stroke, neuropsychiatric disorders and familial encephalopathy with neuroserpin inclusion bodies (FENIB) is presented. To truly understand the detrimental consequences of neuroserpin dysfunction and the effective therapeutic targeting of this molecule in pathological conditions, a cross-disciplinary understanding of neuroserpin alterations and its cellular signaling networks is essential.

Hemorrhagic Transformation in Acute Ischemic Stroke: A Quantitative Systematic Review

The prevalence and risk factors of hemorrhagic transformation (HT) after acute ischemic stroke HT have not been adequately delineated. We performed a systematic review and meta-analysis to identify English-language prospective observational MEDLINE and EMBASE-listed reports of acute ischemic stroke with HT published from 1985–2017. Studies that used the ECASS-2 definitions of hemorrhagic transformation subtypes, hemorrhagic infarction (HI), and parenchymal hematoma (PH) were included. Patients treated with intravenous thrombolysis with tissue plasminogen activator (IV-tPA) were compared with those who did not receive thrombolysis. A total of 65 studies with 17,259 patients met inclusion criteria. Overall, HT prevalence was 27%; 32% in patients receiving IV-tPA vs. 20% in those without. Overall PH prevalence was 9%; 12% in IV-tPA treated patients vs. 5% in those without. HT was associated with a history of atrial fibrillation (OR 2.94) and use of anticoagulants (OR 2.47). HT patients had higher NIHSS (Hedge’s-G 0.96) and larger infarct volume (diffusion-weighted MRI, Hedge’s-G 0.8). In IV-tPA treated patients, PH correlated with antiplatelet (OR 3) and statin treatment (OR 4). HT (OR 3) and PH (OR 8) were associated with a poor outcome at 90-day (mRS 5–6). Hemorrhagic transformation is a frequent complication of acute ischemic stroke and is associated with poor outcome. Recognition of risk factors for HT and PH may reduce their incidence and severity.

Prognostic Significance of Admission Glucose Combined with Hemoglobin A1c in Acute Ischemic Stroke Patients with Reperfusion Therapy

Background: Elevated admission glucose and hemoglobin A1c (HbA1c) levels have been suggested to be associated with 90-day functional outcomes in acute ischemic stroke (AIS) patients with endovascular thrombectomy (EVT). However, whether the prognostic significance of admission glucose and that of HbA1c have a joint effect on patients with intravascular thrombolysis (IVT) and/or EVT remains unclear. This study aimed to explore the association between admission glucose combined with HbA1c and outcomes in patients with reperfusion therapy. Methods: Consecutive AIS patients treated with IVT and/or EVT between 2 January 2018 and 27 February 2021 in West China hospital were enrolled. Admission glucose and HbA1c levels were measured at admission. Participants were divided into four groups according to admission glucose level (categorical variable: <7.8 and ≥7.8 mmol/L) and HbA1c level (categorical variable: <6.5% and ≥6.5%): normal glucose and normal HbA1c (NGNA), normal glucose and high HbA1c (NGHA), high glucose and normal HbA1c (HGNA), and high glucose and high HbA1c (HGHA). The primary outcome was an unfavorable functional outcome defined as a modified Rankin Scale (mRS) ≥ 3. The secondary outcome was all-cause mortality at 90 days. Results: A total of 519 patients (mean age, 69.0 ± 13.4 years; 53.8% males) were included. Patients in the HGHA group had a significantly increased risk of unfavorable functional outcome (OR, 1.81; 95%CI, 1.01–3.23) and mortality (OR, 1.75; 95%CI, 1.01–3.06) at 90 days compared with those in the NGNA group after adjustment for confounders. There was no significant association between NGHA (OR, 0.43; 95%CI, 0.12–1.53) or HGNA (OR, 1.46; 95%CI, 0.84–2.56) and outcomes compared to the NGNA group. Conclusion: The combination of high admission glucose and high HbA1c level was significantly associated with unfavorable functional outcome and mortality at 90 days in AIS patients with reperfusion therapy.

Association of Stress Hyperglycemia Ratio With Acute Ischemic Stroke Outcomes Post-thrombolysis

Background and Purpose: The association between stress hyperglycemia and clinical outcomes in patients with acute ischemic stroke treated with intravenous thrombolysis (IVT) is uncertain. We sought to analyze the association between the stress hyperglycemia ratio (SHR) using different definitions and clinical outcomes in acute patients with ischemic stroke undergoing IVT.

Methods: A total of 341 patients with ischemic stroke receiving IVT were prospectively enrolled in this study. The SHR was evaluated using different equations: SHR1, fasting glucose (mmol/L)/glycated hemoglobin (HbA1c) (%); SHR2, fasting glucose (mmol/L)/[(1.59 × HbA1c)−2.59]; SHR3, admission blood glucose (mmol/L)/[(1.59 × HbA1c)−2.59]. A poor functional outcome was defined as a modified Rankin scale score of 3–6 at 3 months. Multivariate logistic regression analysis was used to identify the relationship between different SHRs and clinical outcomes after IVT.

Results: A total of 127 (37.2%) patients presented with poor functional outcomes at 3 months. The predictive value of SHR1 for poor functional outcomes was better than that of SHR2 and SHR3 in receiver operating characteristic analyses. On multivariate analysis, SHR1 [odds ratio (OR) 14.639, 95% CI, 4.075–52.589; P = 0.000] and SHR2 (OR, 19.700; 95% CI; 4.475–86.722; P = 0.000) were independently associated with an increased risk of poor functional outcome but not SHR3.

Conclusions: Our study confirmed that the SHR, as measured by SHR1 and SHR2, is independently associated with worse clinical outcomes in patients with ischemic stroke after intravenous thrombolysis. Furthermore, SHR1 has a better predictive performance for outcomes than other SHR definitions.

Hyperglycemia in acute ischemic stroke: physiopathological and therapeutic complexity

Diabetes mellitus and associated chronic hyperglycemia enhance the risk of acute ischemic stroke and lead to worsened clinical outcome and increased mortality. However, post-stroke hyperglycemia is also present in a number of non-diabetic patients after acute ischemic stroke, presumably as a stress response. The aim of this review is to summarize the main effects of hyperglycemia when associated to ischemic injury in acute stroke patients, highlighting the clinical and neurological outcomes in these conditions and after the administration of the currently approved pharmacological treatment, i.e. insulin. The disappointing results of the clinical trials on insulin (including the hypoglycemic events) demand a change of strategy based on more focused therapies. Starting from the comprehensive evaluation of the physiopathological alterations occurring in the ischemic brain during hyperglycemic conditions, the effects of various classes of glucose-lowering drugs are reviewed, such as glucose-like peptide-1 receptor agonists, DPP-4 inhibitors and sodium glucose cotransporter 2 inhibitors, in the perspective of overcoming the up-to-date limitations and of evaluating the effectiveness of new potential therapeutic strategies.

Prognosis and Predictors of Symptomatic Intracranial Hemorrhage After Endovascular Treatment of Large Vessel Occlusion Stroke

Background

Symptomatic intracranial hemorrhage (sICH) is a devastating complication of endovascular treatment (EVT) in patients with acute ischemic stroke (AIS) and is associated with high risk of disability and mortality. This study intended to evaluate the predictors of sICH after EVT in patients with large vessel occlusion (LVO)-induced AIS.

Methods

We conducted a retrospective review on consecutive AIS patients who underwent EVT in our University hospital between January 2019 and August 2020. The patients were classified into two groups based upon the occurrence of sICH. The main outcomes were the occurrence of sICH using the Heidelberg Bleeding Classification and functional condition at 90 days. Multivariate logistic regression analysis and receiver operating characteristics (ROC) curves were used to identify independent predictors of sICH after EVT.

Results

Three hundred and 69 patients were enrolled in the study, of which 16.8% (n = 62) developed sICH. Favorable neurological outcome was lower in patients with sICH than in patients without sICH (6.5 vs. 43.3%; P < 0.001), with the overall mortality being 112 (30.4%) at 90 days post- EVT. Results from univariate analysis showed significant differences between the two groups in the prevalence of diabetes, initial Alberta Stroke Program Early CT Score (ASPECTS) score, National Institutes of Health Stroke Scale (NIHSS) score after operation, the levels of fasting blood glucose (FBG), neutrophil to lymphocyte ratio (NLR), platelets (PLT), and thrombin time (TT) at admission. Multivariate logistic regression analysis showed that FBG ≥ 7.54 mmol/L (OR: 2.765; 95% confidence interval [CI]: 1.513–5.054), NLR ≥ 5.48 (OR: 2.711; 95% CI: 1.433–5.128), TT at admission ≥ 16.25 s (OR: 2.022; 95% CI: 1.115–3.667), and NIHSS score within 24 h after the operation ≥ 10 (OR: 3.728; 95% CI: 1.516–9.170) were independent predictors of sICH. The combination of NLR ≥ 5.48, FBG ≥ 7.54 mmol/L, TT at admission ≥ 16.25 s, and NIHSS score within 24 h after the operation ≥ 10 generated an optimal prediction model (AUC: 0.723).

Conclusion

Higher levels of FDG, NLR, TT at admission, and NIHSS score after operation were associated with sICH after EVT in patients with LVO-induced AIS.

MicroRNA Transcriptomics Analysis Identifies Dysregulated Hedgehog Signaling Pathway in a Mouse Model of Acute Intracerebral Hemorrhage Exposed to Hyperglycemia

OBJECTIVE

Hyperglycemia is often observed in the patients after acute stroke. This study aims to elucidate the potential effect and mechanism of hyperglycemia by screening microRNAs expression in intracerebral hemorrhage mice.

METHODS

We employed the collagenase model of intracerebral hemorrhage. Twenty male C57BL/6 mice were used and randomly divided in normo- and hyperglycemic. The hyperglycemia was induced by intraperitoneally injection of 50% of Dextrose (8 mL/kg) 3 hours after intracerebral hemorrhage. The neurologic impairment was investigated by neurologic deficit scale. To study the specific mechanisms of hyperglycemia, microRNAs expression in perihematomal area was investigated by RNA sequencing. MicroRNAs expression in hyperglycemic intracerebral hemorrhage animals were compared normoglycemic mice. Functional annotation analysis was used to indicate potential pathological pathway, underlying observed effects. Finally, polymerase chain reaction validation was administered.

RESULTS

Intraperitoneal injection of dextrose significantly increased blood glucose level. That was associated with aggravation of neurological deficits in hyperglycemic compared to normoglycemic animals. A total of 73 differentially expressed microRNAs were identified via transcriptomics analysis. Bioinformatics analyses showed that these microRNAs were significantly altered in several signaling pathways, of which the hedgehog signaling pathway was regarded as the most potential pathway associated with the effect of hyperglycemia on acute intracerebral hemorrhage. Furthermore, polymerase chain reaction results validated the correlation between microRNAs and hedgehog signaling pathway.

CONCLUSIONS

MicroRNA elevated in hyperglycemia group may be involved in worsening the neurological function via inhibiting the hedgehog signaling, which provides a novel molecular physiological mechanism and lays the foundation for treatment of intracerebral hemorrhage.

Initial Stress Hyperglycemia Is Associated With Malignant Cerebral Edema, Hemorrhage, and Poor Functional Outcome After Mechanical Thrombectomy

BACKGROUND

Malignant cerebral edema (MCE) and intracranial hemorrhage (ICH) are associated with poor neurological outcomes despite revascularization after mechanical thrombectomy (MT). The factors associated with the development of MCE and ICH after MT are not well understood.

OBJECTIVE

To determine periprocedural factors associated with MCE, ICH, and poor functional outcome.

METHODS

We retrospectively analyzed anterior cerebral circulation large vessel occlusion cases that underwent MT from 2012 to 2019 at a single Comprehensive Stroke Center. Multivariate logistic regression analyses were performed to determine significant predictors of MCE, ICH, and poor functional outcome (modified Rankin Scale, 3-6) at 90 d.

RESULTS

Four hundred patients were included. Significant independent predictors of MCE after MT included initial stress glucose ratio (iSGR) (odds ratio [OR], 14.26; 95% CI, 3.82-53.26; P < .001), National Institutes of Health Stroke Scale (NIHSS) (OR, 1.10; 95% CI, 1.03-1.18; P = .008), internal carotid artery compared with M1 or M2 occlusion, and absence of successful revascularization (OR, 0.16; 95% CI, 0.06-0.44; P < .001). Significant independent predictors of poor functional outcome included MCE (OR, 7.47; 95% CI, 2.20-25.37; P = .001), iSGR (OR, 5.15; 95% CI, 1.82-14.53; P = .002), ICH (OR, 4.77; 95% CI, 1.20-18.69; P = .024), NIHSS (OR, 1.10; 95% CI, 1.05-1.16; P < .001), age (OR, 1.04; 95% CI, 1.03-1.07; P < .001), and thrombolysis in cerebral infarction 2C/3 recanalization (OR, 0.12; 95% CI, 0.05-0.29; P < .001).

CONCLUSION

Elevated iSGR significantly increases the risk of MCE and ICH and is an independent predictor of poor functional outcome. Thrombolysis in cerebral infarction 2C/3 revascularization is associated with reduced risk of MCE, ICH, and poor functional outcome. Whether stress hyperglycemia represents a modifiable risk factor is uncertain, and further investigation is warranted.

Body mass index, blood glucose, and mortality in patients with ischemic stroke in the intensive care unit: A retrospective cohort study

BACKGROUND

Excessive BMI was associated with lower mortality after stroke. However, some believed that excessive BMI can lead to a poor prognosis because of some physiological mechanism, such as glucose metabolism disorder. Therefore, this study aims to discuss the association between mortality, BMI, and blood glucose.

MATERIALS AND METHODS

This was a retrospective observational study and all data were extracted from the Medical Information Mart for Intensive Care III database. The exposure was BMI classified into the normal weight group and the excessive weight group. The outcome concluded 30-day, 90-day, and 1-year mortality. The association between two groups and mortality was elucidated by Cox regression models, propensity score matching (PSM) and inverse probability of treatment weighting (IPTW). The underlying effect of blood glucose on the "obesity paradox" was analyzed by causal mediation analysis.

RESULTS

According to Cox regression models, a significant beneficial effect of excessive BMI in terms of mortality was observed: 30-day mortality (HR 0.57, 95% CI 0.35-0.90, P = 0.017), 90-day mortality (HR 0.53, 95% CI 0.36-0.78, P = 0.001), and 1-year mortality (HR 0.65, 95% CI 0.46-0.91, P = 0.013). After PSM and IPTW, we got a similar conclusion. The causal mediation analysis showed that the protective effect of excessive BMI on 30-day mortality reduced with the increase of blood glucose.

CONCLUSION

For ischemic stroke patients in the Intensive Care Unit, those with excessive BMI are associated with both lower short-term mortality and lower long-term mortality, while the protective effect on 30-day mortality weakened accompanied by the increase of blood glucose.

Fasting Blood-Glucose Level and Clinical Outcome in Anterior Circulation Ischemic Stroke of Different Age Groups After Endovascular Treatment

OBJECTIVE

We aimed to analyze the association between fasting blood-glucose (FBG) level and 3-month functional outcome in anterior circulation ischemic stroke in different age groups after endovascular treatment (EVT).

METHODS

We retrospectively analyzed the consecutive patients with acute ischemic stroke (AIS) receiving EVT from our department between July 2015 and March 2021. The patients were categorized into the older (≥60 years) and younger (<60 years) groups, and patients in each age group were dichotomized into favorable versus unfavorable outcomes according to the 3-month modified Rankin Scale (mRS) score.

RESULTS

A total of 504 patients (286 males and 218 females) were included in our study. Three hundred ninety-two patients (77.8%) belonged to the group aged ≥60 years, and 112 (22.2%) belonged to the group aged <60 years. At the end of the study, 222 (56.6%) patients developed unfavorable outcomes in the older group and 31 (27.7%) showed unfavorable outcomes in the younger group. FBG level of the younger patients was significantly lower than that of older patients. In the older group, FBG level independently predicted a 3-month clinical unfavorable outcome with an odds ratio of 1.242 (95% confidence interval, 1.096-1.407; p = 0.001). However, the association was not found in the younger group (p = 0.376).

CONCLUSION

Higher FBG level is an independent risk factor for 3-month unfavorable outcome in the AIS patients aged ≥60 years receiving EVT, but no similar effect was seen in the group aged <60 years.

Effect of Diabetes on Post-stroke Recovery: A Systematic Narrative Review

Background: Patients with stroke often have comorbid diabetes. Considering its detrimental effects on brain function, diabetes may increase the risk of poor recovery.

Methods: The aim of this review was to investigate the effect of diabetes on post-stroke recovery by a systematic review. Several specific aspects of post-stroke recovery, including activities of daily living (ADL), motor, cognitive, and quality of life (QOL) recovery, were examined. We searched the PubMed, SCOPUS, Embase, and Cochrane Library databases for relevant studies on the effect of diabetes on post-stroke recovery, published until May 26, 2021. A total of 52,051 potentially relevant articles were identified. After reading the titles and abstracts and assessing their eligibility based on full-text articles, 34 publications were included in this review.

Results: Of 29 studies that assessed ADL recovery after stroke, 22 studies suggested that diabetes had a negative effect on recovery of ADL after stroke. Regarding motor recovery, only one out of four studies showed that diabetes had some effect on motor recovery after stroke. Of the two studies on cognitive recovery, one reported that diabetes was an independent predictor of poor cognitive recovery after stroke. Three studies on QOL reported that a poor QOL after stroke was associated with the presence of diabetes.

Conclusions: The current review suggests that the post-stroke recovery of ADL seems to be poorer in patients with diabetes than patients without diabetes. Further, there are insufficient data to conclude the effect of diabetes on motor and cognitive recovery, but it may have some influence on the quality of life after stroke.

Systematic Review Registration: doi: 10.37766/inplasy2021.11.0032, identifier: INPLASY2021110032.

Interaction Effect of Baseline Serum Glucose and Early Ischemic Water Uptake on the Risk of Secondary Hemorrhage After Ischemic Stroke

Background and Purpose: Intracerebral hemorrhage (ICH) after mechanical thrombectomy (MT) for acute ischemic stroke (AIS) remains a major complication and its early prediction is of high relevance. Baseline serum glucose (BGL) is a known predictor of ICH, but its interaction with early ischemic changes remains uncertain. We hypothesized that BGL interacts with the effect of tissue water uptake on the occurrence of ICH. Methods: Three hundred and thirty-six patients with acute ischemic stroke treated with MT were retrospectively analyzed. ICH was diagnosed within 24 h on non-enhanced CT (NECT) and classified according to the Heidelberg Bleeding Classification. Early tissue water homeostasis has been assessed using quantitative lesion net water uptake (NWU) on admission CT. Multivariate logistic regression was used to identify predictors of ICH. Results: One hundred and seven patients fulfilled the inclusion criteria of which 37 (34.6%) were diagnosed with ICH. Patients with ICH had a significant higher BGL on admission (median 177 mg/dl, IQR: 127-221.75, P < 0.001). In patients with low BGL (<120 mg/dl), higher NWU was associated with 1.34-fold increased likelihood of ICH, while higher NWU was associated with a 2.08-fold increased likelihood of ICH in patients with a high BGL (>200 mg/dl). In multivariable logistic regression analysis, BGL (OR: 1.02, 95% CI: 1.00-1.04, P = 0.01) and NWU (OR: 2.32, 95% CI: 1.44-3.73, P < 0.001) were significantly and independently associated with ICH, showing a significant interaction (P = 0.04). Conclusion: A higher degree of early tissue water uptake and high admission BGL were both independent predictors of ICH. Higher BGL was significantly associated with accelerated effects of NWU on the likelihood of ICH. Although a clear causal relationship remains speculative, stricter BGL control and monitoring may be tested to reduce the risk of ICH in patients undergoing thrombectomy.

Damage to the blood‑brain barrier and activation of neuroinflammation by focal cerebral ischemia under hyperglycemic condition

Hyperglycemia aggravates brain damage caused by cerebral ischemia/reperfusion (I/R) and increases the permeability of the blood‑brain barrier (BBB). However, there are relatively few studies on morphological changes of the BBB. The present study aimed to investigate the effect of hyperglycemia on BBB morphological changes following cerebral I/R injury. Streptozotocin‑induced hyperglycemic and citrate‑buffered saline‑injected normoglycemic rats were subjected to 30 min middle cerebral artery occlusion. Neurological deficits were evaluated. Brain infarct volume was assessed by 2,3,5‑triphenyltetrazolium chloride staining and BBB integrity was evaluated by Evans blue and IgG extravasation following 24 h reperfusion. Changes in tight junctions (TJ) and basement membrane (BM) proteins (claudin, occludin and zonula occludens‑1) were examined using immunohistochemistry and western blotting. Astrocytes, microglial cells and neutrophils were labeled with specific antibodies for immunohistochemistry after 1, 3 and 7 days of reperfusion. Hyperglycemia increased extravasations of Evan's blue and IgG and aggravated damage to TJ and BM proteins following I/R injury. Furthermore, hyperglycemia suppressed astrocyte activation and damaged astrocytic endfeet surrounding cerebral blood vessels following I/R. Hyperglycemia inhibited microglia activation and proliferation and increased neutrophil infiltration in the brain. It was concluded that hyperglycemia‑induced BBB leakage following I/R might be caused by damage to TJ and BM proteins and astrocytic endfeet. Furthermore, suppression of microglial cells and increased neutrophil infiltration to the brain may contribute to the detrimental effects of pre‑ischemic hyperglycemia on the outcome of cerebral ischemic stroke.

Relationship between fasting blood glucose and subsequent vascular events in Chinese patients with mild ischaemic stroke: a cohort study

Objective

To characterise the relationship between fasting blood glucose (FBG) and the incidence of subsequent vascular events (SVE) during the 6 months following a mild ischaemic stroke (MIS) in Chinese patients.

Methods

Data from patients with MIS were retrospectively analysed. The primary endpoint was an SVE during the 6-month follow-up period. The participants were allocated to three groups (tertiles), according to their FBG concentration.

Results

Of the 260 participants, 51 (19.6%) reported an SVE during the follow-up period. The incidence of SVE significantly differed among the tertiles of FBG. The odds ratio (OR) was 2.361 (95% confidence interval [CI]: 1.551–3.594) for FBG as a continuous variable and that for FBG categorised according to tertile was 13.30 (95% CI: 3.519–50.322) in the fully adjusted model. Curve fitting showed that the incidence of SVE gradually increased with increasing FBG, with the highest tertile showing the highest mean incidence (46.7%; 95% CI: 16.2%–79.9%). In addition, participants with or without diabetes mellitus, hypertension, headache, dizziness, mild cognitive impairment or anterior circulation artery lesion showed similar associations between FBG and the incidence of SVE.

Conclusion

FBG is an independent predictor of 6-month SVE risk in Chinese patients with MIS.

Uric Acid and Gluconic Acid as Predictors of Hyperglycemia and Cytotoxic Injury after Stroke

Hyperglycemia is a feature of worse brain injury after acute ischemic stroke, but the underlying metabolic changes and the link to cytotoxic brain injury are not fully understood. In this observational study, we applied regression and machine learning classification analyses to identify metabolites associated with hyperglycemia and a neuroimaging proxy for cytotoxic brain injury. Metabolomics and lipidomics were carried out using liquid chromatography-tandem mass spectrometry in admission plasma samples from 381 patients presenting with an acute stroke. Glucose was measured by a central clinical laboratory, and a subgroup of patients (n = 201) had apparent diffusion coefficient (ADC) imaging quantified on magnetic resonance imaging (MRI) to estimate cytotoxic injury. Uric acid was the leading metabolite in univariate analysis of both hyperglycemia (OR 19.6, 95% CI 8.6-44.7, P = 1.44 × 10-12) and ADC (OR 5.3, 95% CI 2.2-13.0, P = 2.42 × 10-4). To further prioritize model features and account for non-linear correlation structure, a random forest machine learning algorithm was applied to separately model hyperglycemia and ADC. The statistical techniques used have identified uric acid and gluconic acids as leading candidate markers common to all models (R2 = 68%, P = 2.2 × 10-10 for uric acid; R2 = 15%, P = 8.09 × 10-10 for gluconic acid). Both uric acid and gluconic acid were associated with hyperglycemia and cytotoxic brain injury. Both metabolites are linked to oxidative stress, which highlights two candidate targets for limiting brain injury after stroke.

Which Glucose Parameter Best Predicts Poor Outcome after Mechanical Thrombectomy for Acute Large Vessel Occlusion Stroke?

BACKGROUND

Hyperglycemia is related to adverse outcomes in patients with acute ischemic stroke treated by mechanical thrombectomy (MT).

AIM

To compare the predictive ability of admission blood glucose (ABG), fasting blood glucose (FBG), and glycated hemoglobin (HbA1c) in patients with acute large vessel occlusion (ALVO) stroke undergoing MT.

METHODS

The study retrospectively analyzed the data of 329 consecutive acute stroke patients treated by MT. Multivariate logistic regression analysis was performed to investigate the predictors of poor functional outcome. Receiver operating characteristic (ROC) analysis was performed to identify the predictive ability of ABG, FBG, and HbA1c for poor functional independence in patients with ALVO stroke undergoing MT. In addition, subgroup analyses were performed for both diabetic and nondiabetic patients.

RESULTS

Multiple logistic regression analysis demonstrated that ABG and FBG were independent predictors of 3-month poor functional outcome; however, HbA1c could not predict poor functional outcome. Receiver operating characteristic (ROC) analysis showed that FBG has a higher predictive ability than ABG (areas under the ROC curve [AUCs]: 0.689 vs. 0.624, P = 0.037) and HbA1c (AUCs: 0.689 vs. 0.541, P<0.001) for poor function outcome.

CONCLUSIONS

ABG and FBG are independent predictors of poor functional outcome in patients with acute ischemic stroke undergoing MT, and FBG has a higher predictive ability than ABG and HbA1c. This article is protected by copyright. All rights reserved.

Peroxynitrite activates NLRP3 inflammasome and contributes to hemorrhagic transformation and poor outcome in ischemic stroke with hyperglycemia

This study aims to test the hypothesis that peroxynitrite-mediated inflammasome activation could be a crucial player in the blood-brain barrier (BBB) disruption, hemorrhagic transformation (HT) and poor outcome in ischemic stroke with hyperglycemia. We used an experimental rat stroke model subjected to 90 min of middle cerebral artery occlusion plus 24 h or 7 days of reperfusion with or without acute hyperglycemia. We detected the production of peroxynitrite, the expression of NADPH oxidase, iNOS, MMPs and NLRP3 inflammasome in the ischemic brains, and evaluated infarct volume, brain edema, HT, neurological deficit score and survival rates. Our results show that: (1) Hyperglycemia increased the expression of NADPH oxidase subunits p47phox and p67phox, and iNOS, and the production of peroxynitrite. (2) Hyperglycemia increased infarct volume, aggravated the BBB hyperpermeability, induced brain edema and HT, and worsened neurological outcomes. These brain damages and poor outcome were reversed by the treatments of FeTmPyP (a representative peroxynitrite decomposition catalyst, PDC), peroxynitrite scavenger uric acid, and iNOS inhibitor 1400W. Furthermore, the activations of MMPs and NLRP3 inflammasome including pro/active-caspase-1 and IL-1β were inhibited both PDC and 1400W, indicating the roles of peroxynitrite in the inductions of MMPs and NLRP3 inflammasome in the ischemic brains under hyperglycemia. (3) NLRP3 inflammasome inhibitor MCC950, caspase-1 inhibitor VX-765 and IL-1β inhibitor diacerein attenuated brain edema, minimized hemorrhagic transformation and improved neurological outcome, demonstrating the roles of NLRP3 inflammasome in the hyperglycemia-mediated HT and poor outcome in the ischemic stroke rats with acute hyperglycemia. In conclusion, peroxynitrite could mediate activations of MMPs and NLRP3 inflammasome, aggravate the BBB damage and HT, and induce poor outcome in ischemic stroke with hyperglycemia. Therefore, targeting peroxynitrite-mediated NLRP3 inflammasome could be a promising strategy for ischemic stroke with hyperglycemia.

Personalized Consideration of Admission-Glucose Gap between Estimated Average and Initial Glucose Levels on Short-Term Stroke Outcome

BACKGROUND

Poststroke hyperglycemia is associated with poor outcomes. Most prior studies used initial glucose as an indicator of poststroke hyperglycemia without considering glycemic control status at the time of stroke occurrence. We aimed to investigate the effect of an admission-glucose gap on short-term functional outcomes in acute ischemic stroke (AIS).

METHODS

We enrolled patients with AIS or transient ischemic attack who had been admitted within 7 days of symptom onset to three stroke centers from May 2016 to December 2019. The admission-glucose gap between estimated average glucose levels (eAG) and initial glucose level (eAG-initial glucose) was categorized into four groups. The short-term functional outcome was evaluated using the modified Rankin Scale (mRS) score at 3 months after stroke onset and was dichotomized.

RESULTS

Among 1332 included subjects, 548 (41.1%) had poor short-term functional outcomes. After adjusting for multiple variables, a severe negative glucose gap (eAG-initial glucose ≤ -50 mg/dL) was significantly associated with poor short-term functional outcome (OR, 1.573; 95% CI, 1.101-2.248). After dichotomizing glycemic control status, its significance was only maintained in the good glycemic control group (HbA1c < 6.5%) (OR, 1.914; 95% CI, 1.155-3.169).

CONCLUSIONS

An elevated admission-glucose gap, in which the initial glucose level was much higher than the estimated glucose level was based on HbA1c, was associated with poor stroke prognosis. In addition to admission-glucose levels, glycemic control status at the time of stroke onset should be considered when predicting short-term stroke outcomes.

The Hsp90 Inhibitor 17-DMAG Attenuates Hyperglycemia-Enhanced Hemorrhagic Transformation in Experimental Stroke

Introduction

Hemorrhagic transformation (HT) is one of the most common complications of ischemic stroke which is exacerbated by hyperglycemia. Oxidative stress, inflammatory response, and matrix metalloproteinases (MMPs) have been evidenced to play a vital role in the pathophysiology of HT. Our previous study has reported that 17-DMAG, an Hsp90 inhibitor, protects the brain against ischemic injury via inhibiting inflammation and reducing MMP-9 after ischemia. However, whether 17-DMAG would attenuate HT in hyperglycemic middle cerebral artery occlusion (MCAO) rats is still unknown.

Methods

Acute hyperglycemia was induced by an injection of 50% dextrose. Rats were pretreated with 17-DMAG before MCAO. Infarction volume, hemorrhagic volume neurological scores, expressions of inflammatory molecules and tight junction proteins, and activity of MMP-2 and MMP-9 were assessed 24 h after MCAO.

Results

17-DMAG was found to reduce HT, improve neurological function, and inhibit expressions of inflammatory molecules and the activation of MMPs at 24 h after MCAO.

Conclusion

These results implicated that Hsp90 could be a novel therapeutic target in HT following ischemic stroke.

Impact of aging and comorbidities on ischemic stroke outcomes in preclinical animal models: A translational perspective

Ischemic stroke is a highly complex and devastating neurological disease. The sudden loss of blood flow to a brain region due to an ischemic insult leads to severe damage to that area resulting in the formation of an infarcted tissue, also known as the ischemic core. This is surrounded by the peri-infarct region or penumbra that denotes the functionally impaired but potentially salvageable tissue. Thus, the penumbral tissue is the main target for the development of neuroprotective strategies to minimize the extent of ischemic brain damage by timely therapeutic intervention. Given the limitations of reperfusion therapies with recombinant tissue plasminogen activator or mechanical thrombectomy, there is high enthusiasm to combine reperfusion therapy with neuroprotective strategies to further reduce the progression of ischemic brain injury. Till date, a large number of candidate neuroprotective drugs have been identified as potential therapies based on highly promising results from studies in rodent ischemic stroke models. However, none of these interventions have shown therapeutic benefits in stroke patients in clinical trials. In this review article, we discussed the urgent need to utilize preclinical models of ischemic stroke that more accurately mimic the clinical conditions in stroke patients by incorporating aged animals and animal stroke models with comorbidities. We also outlined the recent findings that highlight the significant differences in stroke outcome between young and aged animals, and how major comorbid conditions such as hypertension, diabetes, obesity and hyperlipidemia dramatically increase the vulnerability of the brain to ischemic damage that eventually results in worse functional outcomes. It is evident from these earlier studies that including animal models of aging and comorbidities during the early stages of drug development could facilitate the identification of neuroprotective strategies with high likelihood of success in stroke clinical trials.