bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract TP208: A Novel Rat Model Of Vascular Parkinsonism Using The Vasoconstrictor Endothelin-1
Authors: Kaufhold Cassandra , Grimalo Lucero , Srinivasan Rahul , Sohrabji Farida
Published: February 2023

Background:
Vascular parkinsonism (VP) results from one or more small strokes in the basal ganglia. Patients with vascular parkinsonism usually are unaware of the individual strokes that occur, until progressive motor symptoms gradually appear. While Parkinson’s Disease (PD) and VP share some common symptoms, patients with VP show clear evidence of cerebrovascular disease, are likely to be older, more likely to present with gait difficulty rather than tremor, and less likely to respond to the use of levodopa compared with patients with PD. There is currently no clinically effective treatment for this condition and no rodent model established in the field to study VP.

Methods:
To stimulate the onset of VP, male Sprague Dawley rats (10-12 mos) were injected with the vasoconstrictor endothelin-1 (ET-1) into the dorsolateral striatum (DLS) or sham operation. Adhesive-tape removal test (ART) was used to test sensory-motor function at 2- and 5- days post DLS stroke and brains were removed and stained with TTC to assess the location of the infarct. In another set, animals were tested for apomorphine-induced rotational behavior at 21-28 days, in conjunction with immunohistochemistry to assess dopamine loss in the substantia nigra pars compacta.

Results:
We observed a discrete infarct localized to the DLS in animals injected with ET-1. There was no difference in latency to remove the tape in ART outcomes of ET-1 injected animals at 2- and 5- day post ischemia when compared to sham, consistent the fact that these coordinates resulted in a discrete striatal infarction, rather than a cortico-striatal infarction, which is seen in the ET1-induced middle cerebral artery stroke model in rats. At 21- and 28- days post, there was minimal rotational behavior and minimal loss of tyrosine hydroxylase (TH)-positive cells in the lesioned hemisphere, unlike that of the 6-OHDA model of PD, where rapid changes are seen in rotational behavior and loss of TH-positive cells.

Conclusions:
These data suggest that ET-1-mediated ischemia into the DLS is a promising model for the slow progression of dopaminergic loss and motor deficits reminiscent to that seen in VP patients. Apomorphine induced rotations and TH immunohistochemistry will be evaluated at 30-, 60- and 90- day timepoints.
Abstract TP210: Small Extracellular Vesicle-derived Micrornas Differentiate Ischemic Stroke And Intracerebral Hemorrhage: A Pilot Study
Authors: Knepp Bodie , Rodriguez Fernando , Jickling Glen , Hull Heather , Ander Bradley , Sharp Frank R , Stamova Boryana
Published: February 2023

Investigating the short and long-term signaling mechanisms via small extracellular vesicles (sEVs) in peripheral blood following human Ischemic Stroke (IS) and Intracerebral Hemorrhage (ICH) is of great interest. The sEV’s cargo can induce distant responses which can be used to derive potential novel therapeutic targets and biomarkers to differentiate the two brain pathologies. Thus, we sequenced the miRNA cargo derived from peripheral blood sEVs in IS (n=3), ICH (n=3), and Vascular Risk Factor-matched Control (VRFC; n=3) subjects. Subjects were divided into contrast groups (IS vs VRFC, ICH vs VRFC, ICH vs IS), and log2 transformed expression underwent Kruskal-Wallis tests to identify differentially expressed (DE; p<0.05) miRNAs. We found 55 DE miRNAs in IS vs VRFC, 38 in ICH vs VRFC, and 45 in ICH vs IS (
Fig. 1A
). The combination of these miRNAs differentiated the three groups on Principal Components Analysis (
Fig. 1B
). IS associated miRNA included miR-30a, miR-30b, and miR-144. miR-30a is involved in hematopoietic stem cell self-renewal and can impair B cell differentiation. miR-30b may be an immune suppressor via Notch1. In male mice, miR-144 is protective against atherosclerosis. ICH associated miRNA included miR-195, miR-1-3p, and miR-20b-5p. miR-195 can inhibit the pro-inflammatory roles of macrophages. miR-1-3p is involved in cardiomyocyte development, can target TLR1 (Toll-Like Receptor 1), and may regulate autophagy. miR-20b-5p reduces Amyloid Precursor Protein (APP) mRNA and protein levels; vascular accumulation of APP is one cause of Lobar ICH. We show differential expression of sEV-derived miRNAs in peripheral blood of human IS and ICH patients that are involved in relevant signaling processes. sEV cargo profiles pose a largely underexplored intercellular signaling mechanism in IS and ICH with the potential to better characterize long distance signaling from injured brain to peripheral blood leukocytes in these brain disorders.
Abstract TP216: Suppression Of Macrophage Activation By Myelin
Authors: DeLong Jonathan H , Sun Leonardo , Velazquez Sofia , Landreneau Margaret , Sansing Lauren H
Published: February 2023

Introduction:
In intracerebral hemorrhage, blood-derived macrophages contribute to a neurotoxic inflammatory response. The endogenous signals that are able to suppress this response are poorly understood. Macrophages likely phagocytose myelin in the CNS during intracerebral hemorrhage and uptake of myelin limits macrophage cytokine production in response to LPS. The components of myelin responsible for its suppressive effects are not well understood, although cholesterol is a likely candidate. Additionally, the broader effects of myelin on macrophage phenotype have not been investigated.

Methods and Results:
Murine bone marrow-derived macrophages were treated with cholesterol before stimulation with S100A9 or LPS. The inflammatory response was measured by production of TNF, IL-6, CCL2, and IL-10 by ELISA. Cholesterol limited inflammatory cytokine production in response to LPS but not to S100A9. The LXR antagonist GSK2033 partially blocked the suppressive effects of cholesterol but activation of LXR with T0901317 was not sufficient to suppress cytokine production. An RNA-Seq screen was performed to examine broader effects of myelin and cholesterol uptake. BMDMs were pretreated with cholesterol, myelin, or the LXR agonist T0901317 before stimulation with S100A9, LPS, TNF, IFNg, IL-4, IL-10, TGFb, Poly(I:C), or Pam3CSK4. Myelin suppressed responses to all of these stimulations, as did T0901317 but to a lesser extent. Cholesterol suppressed the macrophage response to LPS but not the other stimulations.

Conclusions:
Myelin broadly limits macrophage responses to pro-inflammatory signals. Cholesterol alone limits the response to LPS, partially through activation of LXR, but LXR-independent mechanisms appear to be involved as well. Cholesterol does not limit the response to other stimulations, suggesting that other components of myelin or activation of phagocytic receptors contribute to suppression of the macrophage response.
Abstract TP22: Temporal Lobe Involvement In Cerebral Amyloid Angiopathy Related Inflammation Is Associated With Relapse Of Inflammation And Rapidly Progressive Cognitive Decline
Authors: Kharal Abbas , Saleem Ehaab , Heugel Michelle , Amin Moein , Uchino Ken
Published: February 2023

Introduction:
Cerebral Amyloid Angiopathy related inflammation (CAARI) is an autoimmune cause of rapidly progressive cognitive decline. Little is known about the magnetic resonance imaging (MRI) brain features associated with relapse of CAARI and the effect of treatment on relapse rates therefore we sought to study this.

Methods:
In this single center prospective cohort study, we analyzed MRI brain scans of 22 patients with CAARI followed at the Cleveland Clinic Cerebrovascular Center between September 2019 and July 2022. We divided patterns of edema on T2 FLAIR imaging into focal, multifocal or diffuse and assessed for temporal lobe involvement (TLI). We analyzed hemosiderin sensitive sequences for the pattern of CAA including cerebral microbleeds (CMB), macrohemorrhage (MH) and/or cortical superficial siderosis (cSS). We collected data on clinical features, treatment duration and cognition after treatment. Relapse was defined as recurrence of edema on T2 FLAIR with cognitive decline or seizure. We report percentages of each clinical feature, imaging pattern and treatment effect on relapse rates.

Results:
Median age was 74 (35% male, 75% White). Progressive cognitive decline (68%) and seizures (68%) were common but headaches (27.2%) occurred less frequently. Most common CAA features were asymmetric CMB (100%), followed by MH (45%) and cSS (22.7%). The most common pattern of cerebral edema was multifocal (50%), followed by focal (31.8%) and diffuse (27.2%). TLI was seen in 17 (77%) patients. 21 (95.4%) patients were treated with prednisone for median (Q1, Q3) duration of 20 (12, 24) weeks whereas 5 (22.7%) were treated with long term mycophenolate. A total of 6 (27.2%) relapses were seen during a median (Q1, Q3) follow up period of 14 (7, 21) months and occurred at a median (Q1, Q3) of 5.5 (5.12, 5.5) months after stopping steroids. Amongst those who relapsed, none were on mycophenolate, 4 (66.6%) had diffuse edema, 2 (33.4%) had focal edema and all had asymmetric CMB and TLI. No relapses were seen after initiating mycophenolate.

Conclusion:
Asymmetric CMBs, diffuse or focal cerebral edema with temporal lobe involvement and not being on steroid sparing therapy were associated with relapse of CAARI and rapidly progressive cognitive decline.
Abstract TP220: The Aging Ovary Impairs Acute Stroke Outcomes
Authors: Branyan Taylor E , Kosel Kelby F , Lepe Esteban , Sohrabji Farida
Published: February 2023

Background:
Adult female rats (5-7 mos) sustain smaller infarcts after middle cerebral artery occlusion (MCAo) compared to middle-aged rats (10-12 mos), likely due to loss of estrogen. Ovariectomizing adult female rats increases infarct volume, and estrogen treatment rescues this effect. Interestingly, ovariectomizing middle-aged female rats and treating with estrogen worsens stroke outcomes. This study aims to assess what role the aging ovary plays in regulating acute stroke outcomes.

Methods:
Reproductively senescent (RS) underwent ovariectomy (OVX) or sham OVX surgery and allowed to recover for 3 weeks. Animals were then subjected to MCAo using endothelin-1 to induce a stroke. Sensory motor function was monitored at 2- and 5-days post-stroke using the adhesive removal task (ART) and the vibrissae-evoked forelimb placement task (VIB). Animals were terminated at 5d post-stroke, brains were excised and stained with TTC, and infarct volume was calculated and normalized to contralateral hemisphere volume. Ovaries were flash frozen, then protein was extracted and analyzed with a Milliplex 27-analyte cytokine panel.

Results:
OVX animals showed reduced latency in ART at both 2- and 5-days post-stroke, indicating improvement in sensory motor function, compared to intact females. Both OVX and intact animals showed impairment in the VIB task at 2-days post-stroke; however, the OVX group recovered by 5 days. Finally, there was a statistical trend towards a reduction in infarct volume in the OVX group (p=0.0862). Analysis of 27 cytokines showed that 5 cytokines (IL-1β, IL12p70, IFNγ, IL-18, and RANTES) were decreased in the aging ovary in the animals that underwent ET-1 surgery compared to shams. Such a decrease was not observed in young ovaries. A Pearson’s correlation matrix indicated significant negative correlations between 2-day ART performance and ovarian expression of IL-6 and IL-10.

Conclusions:
These results indicate that secretions of the aging ovary impair stroke recovery, and that the aging ovary may respond to stroke via extravasation of immune cells into circulation. These data suggest the novel hypothesis that stroke severity in aging females may be exacerbated by the aging ovary.
Supported by
RFAG042189 to FS and 1F31NS118970-01A to TEB.
Abstract TP222: Aging-associated Medin Induces Human Brain Microvascular Endothelial Cell Pro-inflammatory And Pro-thrombotic Activation Partly Via NFκB
Authors: Nabaty Natalie L , Karamanova Nina , Truran Seth , Morrow Kaleb , Schafer Robert , Nikkhah Mehdi , Li Ming , Madine Jillian , Migrino Raymond Q
Published: February 2023

Background:
Vascular aging is characterized by endothelial dysfunction and proinflammatory & prothrombotic changes. It is responsible for aging-associated pathologies including stroke, vascular dementia (VaD) and Alzheimer’s disease (AD). The underlying mechanisms of vascular aging are poorly understood. Medin is an amyloidogenic protein that accumulates in aging vasculature, is associated with VaD and AD, and is a candidate mediator of vascular aging through unknown mechanisms. Our aim is to test the hypothesis that medin induces proinflammatory and prothrombotic changes in human brain microvascular endothelial cells (HBMVECs) through nuclear factor kappa B (NFκB).

Methods:
HBMVECs were exposed to vehicle, recombinant medin (5 μM, a physiologically relevant dose) without or with RO106-9920 (a small molecule selective NFκB inhibitor, 10 μM) or RO106-9920 alone for 20 hours (N=3-17/treatment). Cell lysates were measured for gene expression of inflammatory cytokines/chemokines (IL-8, IL-6, ICAM-1 and VCAM-1) and thrombotic factors (thrombomodulin (TM), a transmembrane glycoprotein and potent inhibitor of coagulation, plasminogen activator inhibitor-1 (PAI-1) which promotes thrombosis and tissue factor (TF) which initiates the coagulation cascade), using real time PCR.

Results:
See Figure. Medin increased gene expression of IL-8, IL-6, ICAM-1, VCAM-1 and PAI-1, reduced TM with no change in TF. Co-treatment of medin with RO106-9920 attenuated the increases in IL-8, IL-6, ICAM-1, VCAM-1 and the reduction in TM, with no change in PAI-1.

Conclusions:
Medin caused increased pro-inflammatory gene expression in HBMVECs. It also caused reduced TM and increased PAI-1 gene expression, signifying prothrombotic activation. Co-treatment with NFκB inhibitor prevented medin’s proinflammatory effect, and effect on TM, but not PAI-1. The effect of inducing endothelial cell activation supports medin as a potential novel target to treat vascular aging.
Abstract TP224: Clotting Analysis Of Computational Model Of Direct Thrombosis In Cerebral Aneaurysms
Authors: Hume Struan , Chien Aichi , Ngoepe Malebogo , Ho Wei Hua , Peach Thomas
Published: February 2023

Introduction:
Many direct thrombosis models for cerebral aneurysms include complicated clotting mechanisms. For example there are models accounts for biochemical reactions and hemodynamics, using a level-set method to track the surface of the expanding clot and models with a coupled direct thrombosis CFD model that predicts thrombus stability and platelet composition. The presented model simplifies clotting in favor of being better able to meet computational time demands whilst retaining sufficient accuracy for use in clinical settings.

Methodology:
A pulsatile-flow direct thrombosis-model has been created in ANSYS® Fluent using a transient-solution implicit pressure-based solver, wherein two patient-derived cerebral aneurysm geometries are applied, and a porous model and Michaelis Menten formulation inclusive of fibrinogen, thrombin and fibrin are applied to model clotting. Clotting is regulated by the concentration of fibrin and flow shear rate. Solutions are computed for each patient-derived cerebral aneurysm geometry with and without the inclusion of a stent and clotting outcomes are evaluated.

Results:
Total occlusion occurs in both patient-derived cerebral aneurysm geometries with the inclusion of a stent. Without stents installed, one patient-derived cerebral aneurysm geometry that included a giant aneurysm occluded fully, while the other aneurysm geometry partially occluded.

Conclusion:
The clotting outcomes for the aneurysms resulting in full occlusion make sense given significant reduction of flow into the aneurysm and wall-shear stress along the aneurysm wall. The isolated interaction between thrombin and fibrinogen to produce fibrin shown that the model is reasonable in comparison to clot times measured for a previously published thrombin-fibrinogen in vitro experiment . Future work incorporates the results of an in-vitro particle image velocimetry validation experiment inclusive of clotting for adjustment of the presented model.
Abstract TP228: Differential Effect Of Serum From Intracerebral Hemorrhage And Small Vessel Disease Patients On Nonischemic Cerebral Arteries
Authors: Hunt Ryan D , Clark Wayne M , Cipolla Marilyn J
Published: February 2023

Introduction:
There is evidence that circulating factors disrupt vessel function in the contralateral hemisphere after stroke. However, how different stroke subtypes, that have more severe vascular disruption, affect nonischemic vessels is unknown. Here, we compared circulating factors from human patients with distinct stroke subtypes of cardioembolic (CE), small vessel disease (SVD), and intracerebral hemorrhage (ICH). We hypothesized that serum from ICH patients would cause greater vascular dysfunction of nonischemic arteries than CE, and that serum from SVD patients would have an intermediate effect.

Methods:
Serum was obtained 24 hours poststroke from patients with SVD (n=3), ICH (n=4), and CE (n=7) and pooled. All patients had a medical history of hypertension. Only SVD and CE patients received tPA. Pooled serum 20% v/v was perfused into the lumen of 3
rd
order posterior cerebral arteries (PCA, CE & ICH n=5, SVD n=6) that were mounted on glass cannulas and pressurized in an arteriograph chamber. Blood brain barrier (BBB) permeability and vascular reactivity was studied to investigate effects on myogenic tone and endothelial function. Data are presented as mean±SEM.

Results:
All vessels reacted myogenically at pressures ≥40 mmHg. However, serum from ICH patients caused a significant increase in tone at 20 mmHg vs. CE and SVD groups: 37.5±1.6 vs. 9.0±1.9% and 13.0±4.8% p<0.05. There was no difference in dilation to NS309; however, constriction to nitric oxide synthase (NOS) inhibition with L-NAME was impaired with SVD and ICH serum compared to CE: 14.0±2.3% vs. 4.6±0.8% (p<0.05) and 5.8±2.1% (p=0.09). However, reactivity to sodium nitroprusside, an NO donor, was not different between groups. Serum caused an increase in BBB permeability over time that was not different with the different serums.

Conclusions:
Circulating factors from ICH, SVD and CE patients had differing vascular effects on nonischemic cerebral arteries. Serum from ICH patients was vasoconstrictive, potentially due to hemostatic factors, whereas serum from both SVD and ICH patients had impaired NO reactivity demonstrating endothelial dysfunction. These effects of ischemic stroke could affect the contralateral hemisphere and contribute to outcome and therapeutic responses.
Abstract TP229: Impact Of Genetic Polymorphisms On The Risk Of Epilepsy Amongst Patients With Acute Brain Injury: A Systematic Review
Authors: Misra Shubham , Quinn Terence J , Falcone Guido J , Sharma Vijay K , De Havenon Adam H , Zhao Yize , Eldem Ece , Yasuda Clarissa , Dawson Jesse , Liebeskind David S , Kwan Patrick , Mishra Nishant K
Published: February 2023

Introduction:
Stroke and traumatic brain injury (TBI) accounts for 70% of secondary epilepsy in the adult population. The genetic architecture of epilepsy secondary to TBI or stroke is poorly understood.

Objective:
We undertook a systematic review to test the association of single nucleotide polymorphisms (SNPs) with the risk of posttraumatic epilepsy (PTE) and post-stroke epilepsy (PSE).

Methods:
We conducted a comprehensive literature search until 5 July 2022 in PubMed, Embase, PsycINFO, Web of Science, and Google Scholar. We preregistered the protocol of this systematic review on PROSPERO (CRD42022325617). We collated the association statistics from the articles to assess the association of SNPs with the risk of epilepsy amongst TBI or stroke patients. We assessed the study quality using the Quality of Genetic Association (Q-Genie) tool. We report Odds Ratio (OR) and Hazard Ratio (HR) with a 95% confidence interval (CI), including combined OR where a meta-analysis was possible.

Results:
The literature search yielded 420 articles, of which 16 were included in our systematic review. Q-Genie-based assessment of the literature found that 58% of the included studies were of poor quality. We examined published data on 127 SNPs from 32 genes identified in PTE and PSE patients. Twelve studies reported that 718 TBI patients (21%) suffered from PTE. Four studies reported PSE in 1192 stroke patients (50%). Eleven SNPs were associated with an increased risk of PTE. Three SNPs,
TRMP6
rs2274924,
ALDH2
rs671,
CD40
-1C/T, were significantly associated with an increased risk of PSE, while two SNPs,
AT1R
rs12721273 and rs55707609, were significantly associated with reduced risk. Only two studies tested the association of
APOE
E4
with PTE; no other studies validated previously reported genetic association data. Hence, the limited data precluded meta-analysis of all but one SNP, i.e., the
APOE
E4
allele. The meta-analysis for the association of the
APOE
E4
allele with PTE was non-significant (OR 1.8, CI 0.6-5.6).

Conclusions:
The current evidence on the association of genetic polymorphisms in epilepsy secondary to TBI or stroke is of low quality and lacks validation. A collaborative effort to pool genetic data linked to epileptogenesis in stroke and TBI patients is warranted.
Abstract TP23: Depression: An Aftermath Of Stroke
Authors: Bacosa Karen A
Published: February 2023

Background:
As the leading cause of disability, stroke compromises physical and mental health. Stroke survivors are distressed by social challenges and emotional health problems. Many stroke survivors struggle with mental health, even with symptom resolution or returning to physical baseline. The feelings of anger, frustration, fear, and hopelessness are common emotions experienced. The sudden nature of this condition brings an overwhelming strain that significantly impacts patients’ lives.

Objectives:
To screen for post-stroke depression (PSD) in the inpatient setting and examine the feasibility of a nurse-led structured depression screening and early referral based on severity compared to care-as-usual. Neuman’s system model and the Iowa model of evidence-practice complemented the scholarly project by looking at patients holistically with a goal of improving their outcomes.

Methods:
We included two groups: a care-as-usual cohort of discharged stroke patients compared to patients screened for depression within 48 hours of admission for stroke. The Patient Health Questionnaire-9 (PHQ-9) instrument was used to screen stroke patients admitted to the hospital. Patients in the screening group were referred to the organization’s Center for Healthy Living, Depression Care Management, Social Services, and Behavioral Health Management prior to discharge. Descriptive statistics were utilized for data analysis.

Results:
There were 43 patients in the sample, 17 in the screening group and 26 in the care-as-usual group. Depression scores for the screening group had a mean of
M
= 5.7 (range 1-27). The care-as-usual group had a mean of
M
= 49.3 days to depression screening. Of the 43 participants, 12 (27.9%) were depressed; 7 (26.9%) in the usual care group versus 5 (29.4%) in the screening group.

Conclusion:
Establishing the nurse-led PSD screening protocol was feasible for identifying depression among stroke survivors within 48 hours of admission. Research is needed to establish whether the protocol can improve early referral, long-term health outcomes, and quality of care. Recognition of depression in the population of stroke patients may support patients with PSD and facilitate early management of mental health needs.
Abstract TP234: Different Type Of Acute Brain Injuries Share Similar Pattern Of Lipidomic Profile Changes In Human Serum
Authors: Sajanti Antti , Hellström Santtu , Girard Romuald , Frantzen Janek , Umemori Juzoh , Koskimäki Fredrika , Lyne Sean B. , Falter Johannes , Rantamäki Tomi , Nazir Kenneth , Gharat Bajera , Posti Jussi , Roine Susanna , Takala Riikka , Kolehmainen Sulo , Cao Ying , Li Yan , Heino Iiro , Rahi Melissa , Rinne Jaakko , Nieminen Anni I , Castren Eero , Koskimaki Janne
Published: February 2023

Background:
Neuronal recovering processes after acute brain injuries such as aneurysmal subarachnoid hemorrhage (aSAH), ischemic stroke (IS) and traumatic brain injury (TBI) are complex including brain plasticity and synaptic regeneration mechanisms. Temporal changes in lipidomic profile after different acute brain injuries may reveal new insights about brain plasticity, recovery and biomarker development after acute injury.

Hypotheses:
Measurable temporal changes in serum lipidomic profile may be similar irrespective of the type of the brain injury and may reveal conserved molecular aberrations after different types of acute brain injuries. These common changes may also be associated to outcome and serve as possible biomarkers.

Methods:
Prospective cohort (n=74) consisted of IS (n=30), aSAH (n=31) and TBI (n=13) patients. Serum samples were collected in two time points after the insult (early 24-48h and late 120-192h). Lipidomic profiling of 1153 lipids was performed using Lipidyzer Platform. The lipidomics data was analyzed with Metaboanalyst for ANOVA, PCA, heatmap, box plots with following settings: missing values were imputated with KNN using 20% cutoff, log-transformed and auto-scaled.

Results:
We identified four diacylglycerols (DAG), one cholesterol ester (CE), seven triacylglycerols (TAG) and one sphingomyelin (SM) which showed increased levels in late serum samples across all types of brain injuries (p<0.05, FDR corrected). Four free fatty acids (FFA) and two phosphatidylethanolamines (PE) levels were decreased in late serum samples across all injury types (p<0.05, FDR corrected).

Conclusion:
Changes in lipidomic profiles across time were identified. This suggests common lipidomic characteristics irrespective of the type of brain insult and encourage further studies. Interestingly, lipidomic profiles may be associated to recovery after acute brain injury and further analyses of this data will follow.
Abstract TP237: Cofilin Inhibitor Protects Against Hydrogen Peroxide-induced Neuronal Cytotoxicity Via The Inhibition Of Oxidative Stress And Microglial Cell Activation
Authors: Bahader Ghaith A , Antonisamy William James , Shah Zahoor
Published: February 2023

Microglial activation & the failure of the antioxidant defense mechanisms are major hallmarks in different central nervous system injuries, mainly ischemic & hemorrhagic strokes. Cofilin is a cytoskeleton-associated protein involved in actin binding & severing. In our previous studies, we identified the potential role of cofilin in mediating microglial activation & neuronal apoptosis in ischemic & hemorrhagic conditions. Others have highlighted the involvement of cofilin in ROS production & the resultant neuronal death; however, more studies are needed to delineate the role of cofilin in oxidative stress conditions. Hence, the present study is aimed to investigate the role of cofilin in hydrogen peroxide (H
2
O
2
)-induced microglial activation & oxidative neuronal injury & its protection using a first-in-class small-molecule inhibitor of cofilin (SZ-3). An in vitro H
2
O
2
-induced cell death model was used in two different types of cells, human neuroblastoma (SH-SY5Y) & microglial (HMC3) cell lines. Cell viability was assessed by the Cell Counting Kit-8 assay. Western blotting was used to measure the expression levels of several proteins. Our results show that treatment with H
2
O
2
increases the expression of cofilin & slingshot-1 (SSH-1), an upstream regulator of cofilin, in microglial cells, which was significantly reduced in the SZ3 treated group. Cofilin inhibition significantly attenuated H
2
O
2
-induced microglial activation by reducing the release of proinflammatory mediators (HMGB1, TNF-α). Furthermore, we demonstrate that SZ3 protects against H
2
O
2
-induced cytotoxicity in SH-SY5Y cells & activates the AKT signaling pathway by increasing its phosphorylation levels. SZ3 treatment also induces the expression of Nrf2, a major transcription factor that regulates the oxidative stress response, & its related antioxidant enzymes (HO-1, SOD2, NQO1) in the SY-SY5Y cell. Together, these results suggest that cofilin inhibition plays an essential role in protecting neuronal cells under H
2
O
2
-induced oxidative stress, possibly by activating the antioxidant defense mechanisms & reducing microglial activation.
Abstract TP238: Acute Ischemic Stroke Induces Gut Virome And Bacteriome Dysbiosis
Authors: Chelluboina Bharath , Mehta Suresh L , Kieft Kristopher , Breister Adam Michael , Anantharaman Karthik , Vemuganti Raghu
Published: February 2023

We currently evaluated the effect of focal cerebral ischemia on gut virome and bacteriome in adult mice. Adult male C57BL/6 mice were subjected to transient middle cerebral artery occlusion or sham surgery. Virome and bacteriome were analyzed using shotgun metagenomics in the fecal samples collected from each mouse before and at 24h of reperfusion. Bioinformatics tools including VIBRANT (v1.2.1), DIAMOND Blastp (v0.9.14.115), VConTACT2 (v0.9.5), Cytoscape (v3.7.2), mash (v2.0), MUMmer (v3.1), Samtools (v1.11), DESeq2 (v1.28.1), MetaWRAP, and CRISPR Recognition Tool (v1.2) were used to assess viral networks, viral auxiliary metabolic genes, and viral protein network changes. Bacteriome was analyzed by kneaddata v0.7.2, MetaPhlAn version 2.7.7, and humann2 v2.8.1. Focal ischemia induced significant differences in fecal viral and bacterial taxa at the strain levels compared with sham. Furthermore, viral protein networks altered significantly after stroke. In particular, the clusters of Clostridia-like phages and Erysipelatoclostridiaceae phages showed a differential association between stroke and sham. In addition, we identified a significant reduction in the phages and bacteria of Lactobacillus after stroke. These studies indicate a possible viral-bacterial correlative change in the gut after stroke.
Abstract TP242: The Absence Of CD36 Reduced Kras
G12V
-induced Brain Arteriovenous Malformations In Mice.
Authors: Kim Eunhee , Kim Sehee , Wilfer Samantha , Park Eunsu , Lee Minjung , Chen Peng R
Published: February 2023

Introduction:
Brain arteriovenous malformations (bAVMs) are a major risk factor for cerebral hemorrhages in young patients. Recent clinical studies have identified somatic activating KRAS mutations in human bAVMs (~76%), and we confirmed the causal role of endothelial
KRAS

G12V

mutation in bAVM development using a mouse model. However, the pathomechanisms underlying bAVM pathology remain to be determined. CD36 is highly expressed in microglia/macrophages (MMs) and microvascular endothelial cells (ECs) and plays various roles in inflammation and angiogenesis, closely related to vascular development and functions. In this study, we determined if CD36 is involved in bAVM pathophysiology.

Methods:
Mice were injected with either AAV-BR1 carrying GFP (control) or KRAS
G12V
. We determined CD36 expression in the control or bAVM tissues dissected from the mouse brains. We also determined CD36 levels in the in vitro cultured ECs overexpressing KRAS
G12V
. Finally, we determined bAVM numbers and size in CD36 knock-out (ko) mice injected with AAV-BR1-KRAS
G12V
.

Results:
We found that gene expression of CD36 and the ligands, thrombospondin-1 and -2 were significantly increased in the KRAS
G12V
-induced bAVMs. However, the CD36 levels were slightly but significantly reduced in KRAS
G12V
transfected ECs. In the CD36 ko mice, we found that the number of large bAVMs was significantly reduced compared to the control (C57BL/6).

Conclusion:
Our results indicate that CD36 expression is dysregulated in KRAS
G12V
-induced bAVMs and contributes to bAVM development. As CD36 has distinctive roles depending on cell types, the role of CD36 in each cell type (e.g., MMs or ECs) on bAVM pathology should be further determined.
Abstract TP243: Efficacy Of Intra-arterial Stem Cell Therapy In A Canine Model Of Ischemic Stroke: Role Of Anti-inflammatory Action In The Brain
Authors: Thakkar Roshni , Ojeda Pedraza Diego A , Yavagal Dileep R
Published: February 2023

Introduction:
Stroke is the 2
nd
leading cause of death globally. Despite the current standard of care for stroke, more than 50% of stroke survivors are chronically disabled, leading to more than $46 billion in annual economic burden in the US alone. It is therefore imperative to develop novel therapies for stroke. Preclinical studies in the past two decades have shown promise in cell therapies for stroke. Intra-arterial (IA) delivery of Mesenchymal Stem Cells (MSCs) is minimally invasive making it attractive for clinical translation. Recent studies from our lab have shown the safety and efficacy of IA-MSC treatment in rodent and canine ischemic stroke models. These studies from our group have established the precise timing and effective dosage of IA-MSC therapy that leads to improved stroke outcomes. It is believed that IA-MSCs exert their protective effects by mediating anti-inflammatory actions. However, this mechanism is not very well studied, specifically in the large animal brain.

Methods:
In this study we determined the expression pattern of microglia, astrocytes, the Nod-like receptor 3 (NLRP3) inflammasome pathway markers, inflammatory cytokines and the activity of Nuclear factor kappa B subunit 1 (NF-κB) in the large animal canine brain following IA MSC therapy after ischemic stroke. Immunohistochemistry staining and immunofluorescence imaging of the canine brain cortex and hippocampus were performed.

Results:
Numerical quantification showed significant reduction in astrocyte and microglia activation, reduced expression of NLRP3 and Interluekin-1beta at different doses of IA-MSCs (10, 20, and 40 million) at 30 days post-stroke. Results from this study showed a significant dose-dependent reduction in inflammation in the canine hippocampus and the cortex. There was a simultaneous increase in surviving neurons.

Conclusions:
These novel findings help us understand inflammation in the canine brain after stroke. Our data further reveal how IA-MSC therapy mediates its action via inflammatory changes. Overall, this approach contributes to developing more robust and engineered IA-MSCs therapies for stroke patients, leading to more effective translation.
Abstract TP244: The Role Of Smooth Muscle Cyclic GMP-dependent Protein Kinase 2 In Ischemic-reperfusion Injury
Authors: Lee Seeun , Lee Kyungjin , Cho Suin , Atochin Dmitiry , Kim Hyung-Hwan
Published: February 2023

Background and Rationale:
Cyclic GMP-dependent protein kinases (cGK1/2) act as a key mediator of the nitric oxide/cGMP signaling pathway in stroke. The cGK1/2 seems to function as a dimer under physiological conditions. Its potential mechanism in ischemia-reperfusion injury has not been investigated sufficiently. Here, we used smooth muscle cell-specific cGK1 knock-out (cGK1 KO) mice to investigate the variability of cGK1/2 in the ischemic stroke and expected dipyridamole, a non-selective phosphodiesterase inhibitor, will affect vasodilation via eNOS/cGMP/cGK1/2 signaling pathways in ischemic stroke.

Methods:
Mice were subjected to diverse episodes of ischemia-reperfusion injury. Laser Doppler measurements indicated that the relative cerebral blood flow values significantly decreased in cGK1 KO mice on reperfusion. Infarction volume was measured by TTC staining and relative cerebral blood flow was measured by Laser Doppler. We investigated the neurological deficit score at 23h after a 60-minute MCAO. Dipyridamole (60 mg/kg) was orally administered by gavage for 3 consecutive days. Protein levels from brain lysates in the cerebral cortex and hippocampus were studied by western blotting. To assess the time-kinetics of cGK1/2, brain samples were divided into ischemia-reperfusion periods. Neurological deficit and infarction volume were determined 24h later.

Results:
Dipyridamole reduced the infarction volume, improved neurological deficit score, and increased rCBF in control mice but the effect was absent in cGK1 KO mice. Basically, protein levels of both cGK1 and cGK2 in permanent MCAO brain samples were degraded during an ischemic condition time-dependent manner (1~3h). Both cGK1 and cGK2 in whole brain lysates were sustained without protein degradation during ischemia-reperfusion injury in littermate control. The protein expressions of cGK2 in both blood vessels and brains with dipyridamole were rapidly reversed on reperfusion onset in cGK1 KO mice.

Conclusion:
These results suggest that cGK1/2 should be balanced by eNOS/cGMP/cGK1/2 signaling pathways in the ischemic brain and the effect of both cGMP and cGK2 upregulation by dipyridamole mediating the neuroprotection in ischemic brains.
Abstract TP26: System-wide Implementation Of Computed Tomography Perfusion (CTP) Imaging
Authors: Kremers Meghan , Abarca Nancy , Potluri Anvita , Stowe Alicia , Wideman Brian , Miller Malgorzata , Tsai Jenny , Tubergen Tricia , Kline Andrew , Mulderink Todd , Furtaw Scott , Min Jiangyong , Wees Nabil , Khan Nadeem I , Ahrar Asad , Singer Justin , Mazaris Paul , Packard Laurel , Oostema John A , Khan Muhib
Published: February 2023

Background:
Mechanical thrombectomy (MT) is effective for reducing morbidity in patients presenting within 24 hours of symptom onset with large vessel occlusion (LVO). Perfusion imaging is helpful in selecting patients in this extended time window. We report our experience of implementing CTP imaging in all our spokes and its impact on quality metrics and outcomes.

Methods:
Acute Stroke Imaging Protocol was updated to include CTP in addition to CT and CTA for all suspected stroke patients presenting within 24 hours of symptoms in April 2021 processed by RAPID AI (iSchema View inc, Menlo Park, CA, USA). Consecutive patients aged ≥18 years with suspected stroke presenting to regional spokes between Jan 2021 to Dec 2021 were included in the analysis. Demographics, NIHSS, quality metrics at regional facility (Door-to-thrombolysis, door-in-door-out times) and Comprehensive Stroke Center-CSC (door-to-arterial access, reperfusion rates (TICI IIb/III), hemorrhagic transformation) and functional outcomes (modified Rankin Scale, mRS) at 90 days were compared between the groups.

Results:
CTP studies were performed on 1113 patients between April 2021 and December 2021. RAPID AI processing identified LVO in 203 (18.7%) patients, of which 29 (14%) patients were included in this analysis; 14 patients were transferred to CSC for possible MT without CTP at regional facility and 15 were transferred with CTP at regional. Age (p=0.44), NIHSS (p=0.08) and onset-arrival time (p=0.54) were similar in both groups at the regional facility. Door to thrombolysis (p=0.13) and door-in-door-out (p=0.17) times were similar in both groups at the regional facility. CSC metrics of door-to-arterial access times (p=0.84), reperfusion (TICI IIB/III) (p=0.83) and hemorrhagic transformation (p=0.49) rates were similar between groups. 90 day good functional outcomes (mRS 0-2) were similar in patients undergoing thrombectomy (p=0.86).

Conclusion:
Our study suggests that AI supported perfusion imaging is feasible in a large stroke network and does not appear to have a significant impact on process times, quality metrics and outcomes. A larger study would need to be conducted to validate the observed results.
Abstract TP29: Nurse-led Acute Stroke Process Promotes Advocacy And Treatment Times: A Case Series
Authors: Pozo Jessilyn , Cruz Nina , De Los Rios La Rosa Felipe , Belnap Starlie
Published: February 2023

Background:
Reperfusion therapies for acute ischemic strokes are highly time sensitive. Centers across the world have implemented various approaches in treating these patients when presenting to the ED using multidisciplinary team approaches, straight-to-CT, and straight-to-angio suite. Several studies recently published the efficiency of an ED nurse-led stroke process on improving timeliness and decreasing door-to-treatment times.

Purpose:
Little to no literature has focused on how a stroke RN leading a stroke alert process serves as a patient advocate to assist the decision-making process.

Methods:
Our CSC built a stroke program using a multidisciplinary team, parallel workflow approach led by a Stroke Responder, filled by a neuroscience RN specially trained to lead the acute stroke process. This case series exemplifies how the Stroke Responder influenced the decision-making process in 2 stroke alerts.

Case Study 1:
A 60-year old high-profile public figure presented to the ED with mild aphasia. With a low NIHSS, some providers may be reluctant to offer thrombolysis based off risk vs benefit. In this patient’s case, mild aphasia was debilitating to life and career. The stroke RN emphasized this resulting in the patient receiving thrombolysis and making a full recovery to baseline.

Case Study 2:
For an incoming stroke alert on a 90+ year old, the stroke RN received pertinent patient information and a family contact number from EMS via telemedicine. The stroke RN was able to confirm information with family and transferred call to neurologist for consent of thrombolysis prior to patient arrival. Patient was transferred straight-to-CT upon arrival, administered the thrombolytic within 12 min, and subsequently taken for mechanical thrombectomy in the right MCA bifurcation when procedure was aborted due to NIHSS from 13 to 3.

Conclusion:
Highly specialized neuroscience nurses assigned to lead a stroke alert process benefit the patient beyond providing effective care coordination and assisting the neurologist with assessments. They can help drive the decision-making process resulting in higher treatment rates and faster door-to-treatment times.
Abstract TP42: Door To Thrombolysis Administration Times Before And After Tenecteplase Implementation Across Different Hospital Types
Authors: Blaginykh Elena , Brown Dena R , Russman Andrew N , Uchino Ken
Published: February 2023

Background:
The switch from alteplase to tenecteplase as a thrombolytic in acute ischemic stroke has been reported to be associated with faster door-to-needle (DTN) times. We aimed to study the effect of the early transitional experience after tenecteplase switch on DTN across different hospital types.

Methods:
We retrospectively analyzed prospectively collected data of patients that underwent thrombolysis at 7 free-standing emergency departments (FSEDs), 8 primary stroke centers (PSC), 3 thrombectomy-capable stroke centers (TSC), and a comprehensive stroke center (CSC) in a large healthcare system. The distributions of DTN time before (January 2021-January 2022) and after (January 2022-June 2022) tenecteplase implementation were compared. The Mann-Whitney test was used to compare door-to-needle time differences between alteplase and tenecteplase treatment groups.

Results:
Alteplase was given to 318 patients with a median DTN of 40 minutes (interquartile range [IQR]: 27;57) and 154 received tenecteplase with a median DTN of 46 minutes (IQR: 33;63). Patients in the two groups had similar demographic characteristics, NIH Stroke Scale scores, and patient distribution across hospital types. Among tenecteplase-treated patients, 68 (44%) were from FSEDs and PSCs, 67 (44%) were from TSCs, and 19 (12%) were from CSCs. The median DTN time at FSEDs and PSCs increased from 39 (IQR: 27;55) to 56 minutes (IQR: 41;72) after tenecteplase implementation (P<0.0001). At the TSCs the median DTN was 40 minutes (IQR: 29;55) and did not change after the switch to tenecteplase (P=0.31). The median DTN at CSC in the alteplase group was 41 minutes (IQR: 26;72) and 33 minutes (IQR:20;45) in the tenecteplase group (P=0.06).

Conclusion:
For the first 6 months of tenecteplase implementation the DTN time increased at FSEDs and PSCs but remained unchanged in higher volume centers.
Abstract TP45: Demonstration Of High Diagnostic Accuracy Of Cerebral Ischemia In A Large Academic Hub And Spoke Telestroke Network
Authors: Chhabra Nikita , English Stephen W , Hanus Abigail E , Basharath Rida , Miller Monet , Butterfield Richard J , Zhang Nan , Demaerschalk Bart M
Published: February 2023

Introduction:
Telestroke facilitates emergent assessment of patients with suspected acute ischemic stroke (AIS) to identify candidates for acute interventions. The diagnostic accuracy of the telestroke consultation of a large academic hub and spoke telemedicine network has yet to be investigated. The goal of our study is to determine the diagnostic accuracy of the initial telestroke consultation.

Methods:
This is an IRB-exempt retrospective study including all patients evaluated for cerebral ischemia via video telestroke consultation in a large academic hub and spoke telemedicine network from 2019 to 2020. Detailed chart review was conducted to identify initial suspected diagnosis and final diagnosis. Cerebral ischemia was defined as AIS and transient ischemic attack (TIA). All other diagnoses were defined as stroke mimics. Data was organized into continuous and categorical variables. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, area under the curve (AUC) and likelihood ratio (LR+) for the initial telestroke consultation diagnosis were calculated while using the final diagnosis as the gold standard diagnosis.

Results:
A total of 1043 patients met inclusion criteria. Final diagnosis of cerebral ischemia was made in 63.5% of all patients (539/1043 with AIS,123/1043 with TIA). Stroke mimic was diagnosed in 36.5% patients (381/1043). The sensitivity and specificity of telestroke evaluation for diagnosis of cerebral ischemia were 97.1% and 81.4%, respectively. PPV was 90.1%, and NPV was 94.2%. Overall diagnostic accuracy was 91.4% with a LR+ of 5.21 and AUC of 0.89. The most common stroke mimics were metabolic encephalopathy (13.7%, 52/381), migraine (10.8%, 41/381) and seizure (10.5%, 40/381).

Conclusions:
This study highlights the high diagnostic accuracy of telestroke providers to diagnose cerebral ischemia and stroke mimic in a large academic hub and spoke network. Further research is needed to investigate methods to improve our diagnostic accuracy further, as well as explore the application of tele-neurology in the non-stroke setting.