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

Acute ischemic STROKE - from laboratory to the Patient's BED (STROKELABED): A translational approach to reperfusion injury. Study Protocol

Cerebral edema (CE) and hemorrhagic transformation (HT) are frequent and unpredictable events in patients with acute ischemic stroke (AIS), even when an effective vessel recanalization has been achieved. These complications, related to blood-brain barrier (BBB) disruption, remain difficult to prevent or treat and may offset the beneficial effect of recanalization, and lead to poor outcomes. The aim of this translational study is to evaluate the association of circulating and imaging biomarkers with subsequent CE and HT in stroke patients with the dual purpose of investigating possible predictors as well as molecular dynamics underpinning those events and functional outcomes. Concurrently, the preclinical study will develop a new mouse model of middle cerebral artery (MCA) occlusion and recanalization to explore BBB alterations and their potentially harmful effects on tissue. The clinical section of the study is based on a single-center observational design enrolling consecutive patients with AIS in the anterior circulation territory, treated with recanalization therapies from October 1, 2015 to May 31, 2020. The study will employ an innovative evaluation of routine CT scans: in fact, we will assess and quantify the presence of CE and HT after stroke in CT scans at 24 h, through the quantification of anatomical distortion (AD), a measure of CE and HT. We will investigate the relationship of AD and several blood biomarkers of inflammation and extracellular matrix, with functional outcomes at 3 months. In parallel, we will employ a newly developed mouse model of stroke and recanalization, to investigate the emergence of BBB changes 24 h after the stroke onset. The close interaction between clinical and preclinical research can enhance our understanding of findings from each branch of research, enabling a deeper interpretation of the underlying mechanisms of reperfusion injury following recanalization treatment for AIS.

Combined Therapeutics: Future Opportunities for Co-therapy with Thrombectomy

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

Effect of Alteplase Thrombolysis on Coagulation Function and Nerve Function of Patients with Ischemic Stroke

Objective

To investigate the effects of alteplase thrombolysis on coagulation function and nerve function of patients with ischemic stroke.

Methods

76 cases with ischemic stroke receiving thrombolytic therapy in Cangzhou Central Hospital from November 2018 to November 2019 were recruited. They were assigned via the random number table method at a ratio of 1 : 1 to receive alteplase thrombolysis either within 3h after the onset (observation group) or within 3-4.5 h after the onset (control group), followed by aspirin administration after no bleeding in cranial computed tomography (CT). Outcome measures included plasma fibrinogen (FIB), activated partial prothrombin time (APTT), platelet (PLT) levels, the National Institute of Health stroke scale (NIHSS) score, and adverse events.

Results

Alteplase thrombolysis within 3 h was associated with better prothrombin time (PT), APTT, FIB, and PLT levels versus thrombolysis within 3-4.5 h (P < 0.05). Thrombolysis within 3 h showed significantly lower NIHSS scores versus within 3-4.5 h (P < 0.05). The two groups showed a similar incidence of adverse events (X 2 = 2.963, P=0.615).

Conclusion

Alteplase thrombolysis showed benefits in mitigating the coagulation function and nerve function damage of patients with ischemic stroke, especially within 3 hours after the onset, with a high safety profile.

Protective effect of microRNA‑340‑5p against oxygen‑glucose deprivation/reperfusion in PC12 cells through targeting neuronal differentiation 4

The expression levels of microRNA (miR)‑340‑5p are reportedly decreased in the peripheral blood during acute ischemic stroke; however, the direct effect and mechanism of action of miR‑340‑5p in ischemic stroke remains largely unknown. The present study aimed to investigate the effects of miR‑340‑5p, and its mechanism of action, on PC12 cells following oxygen‑glucose deprivation/reperfusion (OGD/R) induction. OGD/R‑induced PC12 cells served as the cellular model and subsequently, mRNA expression levels of miR‑340‑5p and neuronal differentiation 4 (Neurod4) were analyzed using reverse transcription‑quantitative PCR. Tumor necrosis factor‑α, interleukin (IL)‑1β and IL‑6 expression levels were detected using ELISA kits, and flow cytometry was used to determine the rate of cellular apoptosis. In addition, a nitric oxide (NO) synthase activity assay kit was used to detect NO levels and a NADPH assay kit was used to measure NADPH levels. Western blotting was also performed to analyze protein expression levels of bax, bcl‑2, cleaved caspase 3 and phosphorylated endothelial NOS (eNOS), and the target gene of miR‑340‑5p was predicted using TargetScan software and verified using a dual‑luciferase reporter assay. The expression levels of miR‑340‑5p were decreased in PC12 cells following OGD/R induction and Neurod4 was identified as a target gene of miR‑340‑5p. In addition, miR‑340‑5p overexpression reduced inflammation, apoptotic rate, NO production and NADPH levels, in addition to increasing eNOS expression in PC12 cells following OGD/R induction. Notably, the overexpression of Neurod4 reversed the aforementioned effects of miR‑340‑5p on PC12 cells following OGD/R induction. In conclusion, the findings of the present study suggested that miR‑340‑5p may protect PC12 cells against OGD/R through targeting Neurod4, which could provide important implications for the treatment of ischemia‑reperfusion injury based on miR‑340‑5p expression levels in vivo.

Neuroprotective effects of minocycline on focal cerebral ischemia injury: a systematic review

To review the neuroprotective effects of minocycline in focal cerebral ischemia in animal models. By searching in the databases of PubMed, ScienceDirect, and Scopus, and considering the inclusion and exclusion criteria of the study. Studies were included if focal cerebral ischemia model was performed in mammals and including a control group that has been compared with a minocycline group. Written in languages other than English; duplicate data; in vitro studies and combination of minocycline with other neuroprotective agents were excluded. Neurological function of patients was assessed by National Institute of Health Stroke Scale, modified Rankin Scale, and modified Barthel Index. Neuroprotective effects were assessed by detecting the expression of inflammatory cytokines. We examined 35 papers concerning the protective effects of minocycline in focal cerebral ischemia in animal models and 6 clinical trials which had evaluated the neuroprotective effects of minocycline in ischemic stroke. These studies revealed that minocycline increases the viability of neurons and decreases the infarct volume following cerebral ischemia. The mechanisms that were reported in these studies included anti-inflammatory, antioxidant, as well as anti-apoptotic effects. Minocycline also increases the neuronal regeneration following cerebral ischemia. Minocycline has considerable neuroprotective effects against cerebral ischemia-induced neuronal damages. However, larger clinical trials may be required before using minocycline as a neuroprotective drug in ischemic stroke.

Frequency of Blood-Brain Barrier Disruption Post-Endovascular Therapy and Multiple Thrombectomy Passes in Acute Ischemic Stroke Patients

Background and Purpose- The high prevalence of hyperintense acute reperfusion marker (HARM) seen after endovascular therapy is suggestive of blood-brain barrier disruption and hemorrhage risk and may be attributable to multiple thrombectomy passes needed to achieve recanalization. Methods- Patients with acute stroke were included if they were screened from January 2015 through February 2019, received an acute ischemic stroke diagnosis involving the anterior circulation, treated with or without IV tPA (intravenous tissue-type plasminogen activator), consented to the NINDS Natural History Study, and imaged with a baseline magnetic resonance imaging before receiving endovascular therapy. Consensus image reads for HARM and hemorrhagic transformation were performed. Good clinical outcome was defined as 0-2 using the latest available modified Rankin Scale score. Results- Eighty patients met all study criteria and were included in the analyses. Median age was 65 years, 64% female, 51% black/African American, median admit National Institutes of Health Stroke Scale=19, 56% treated with IV tPA, and 84% achieved Thrombolysis in Cerebral Infarction score of 2b/3. Multiple-pass patients had significantly higher rates of severe HARM at 24 hours (67% versus 29%; P=0.001), any hemorrhagic transformation (60% versus 36%; P=0.04) and poor clinical outcome (67% versus 36%; P=0.008). Only age (odds ratio, 1.1; 95% CI, 1.01-1.12; P=0.022) and severe HARM at 24 hours post-endovascular therapy were significantly associated with multiple passes (odds ratio, 7.2; 95% CI, 1.93-26.92; P=0.003). Conclusions- In this exploratory study, multiple thrombectomy passes are independently associated with a significant increase in blood-brain barrier disruption detected at 24 hours. Patients with HARM post-endovascular therapy had a >7-fold increase in the odds of having multiple- versus single-pass thrombectomy. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT00009243.