Left Middle Cerebral Artery Occlusion Research Articles

Dl-3-n-Butylphthalide Alleviates Secondary Brain Damage and Improves Working Memory After Stroke in Cynomolgus Monkeys.

Remote secondary neurodegeneration is associated with poststroke cognitive impairment (PSCI). Dl-3-n-butylphthalide (NBP) improves PSCI clinically. However, whether it ameliorates PSCI by alleviating secondary neurodegeneration remains uncertain. Nonhuman primates provide more relevant models than rodents for human stroke and PSCI. This study investigated the effects of NBP on PSCI and secondary neurodegeneration in cynomolgus monkeys after permanent left middle cerebral artery occlusion (MCAO). Thirteen adult male cynomolgus monkeys were randomly assigned to sham (n=4), MCAO+placebo (n=5), and MCAO+NBP groups (n=4). The MCAO+placebo and MCAO+NBP groups received saline and NBP injections intravenously, respectively, starting at 6-hour postsurgery for 2 weeks, followed by soybean oil and NBP orally, respectively, for 10 weeks after MCAO. Infarct size was assessed at week 4 by magnetic resonance imaging. Working memory and executive function were evaluated dynamically using the delayed response task and object retrieval detour task, respectively. Neuron loss, glia proliferation, and neuroinflammation in the ipsilateral dorsal lateral prefrontal cortex, thalamus, and hippocampus were analyzed by immunostaining 12 weeks after MCAO. Infarcts were located in the left middle cerebral artery region, apart from the ipsilateral dorsal lateral prefrontal cortex, thalamus, or hippocampus, with no significant difference between the MCAO+placebo and MCAO+NBP group. Higher success in delayed response task was achieved at weeks 4, 8, and 12 after NBP compared with placebo treatments (P<0.05), but not in the object retrieval detour task (all P>0.05). More neurons and less microglia, astrocytes, CD68-positive microglia, tumor necrosis factor-α, and inducible NO synthase were observed in the ipsilateral dorsal lateral prefrontal cortex and thalamus after 12 weeks of NBP treatment (P<0.05), but not in the hippocampus (P>0.05). Our findings indicate that NBP improves working memory by alleviating remote secondary neurodegeneration and neuroinflammation in the ipsilateral dorsal lateral prefrontal cortex and thalamus after MCAO in cynomolgus monkeys.

Effect of electroacupuncture on neuronal programmed necrosis by regulating RIP1/RIP3/MLKL pathway in rats with cerebral ischemia reperfusion injury.

To investigate the neuroprotective effect of electroacupuncture (EA) at "Quchi"(LI11) and "Zusanli"(ST36) in the rats with cerebral ischemia reperfusion injury and its influence on programmed necrosis of cerebral cortical neurons. Sixty male SD rats were randomly divided into sham-operation group, model group, EA group and inhibitor group, with 15 rats in each group. Left middle cerebral artery occlusion model was established using the modified thread embolism method. In the sham-operation group, the carotid artery was exposed and dissociated in each rat. EA was applied to "Quchi"(LI11) and "Zusanli"(ST36) on the right side for 30 min each time, once daily for 7 days in the rats of the EA group. The rats in the inhibitor group were intraperitoneally injected with norstatin-1 (0.6 mg/kg) for consecutive 7 days. The neurological deficit score of rats in each group was observed. HE staining was adopted to detect the degree of pathological damage of the cerebral cortex in the infarction area. Using TUNEL staining, the apoptosis of cortical neurons in the infarction area was determined；the contents of tumor necrosis factor α (TNF-α), interleukin (IL)-1β and IL-6 were detected by ELISA；the mRNA and protein expression of the receptor interacting protein-1 (RIP1), the receptor interacting protein-3 (RIP3) and the substrate mixed lineage kinase like protein (MLKL) were detected by fluorescence quantitative PCR and Western blot, respectively. In comparison with the sham-operation group, the neurological deficit score in the model group was higher(P<0.01)；HE staining showed that there was the pathological damage in the infarction area；the neuron apoptosis rate, the contents of TNF-α, IL-1β and IL-6, and the mRNA and protein expressions of RIP1, RIP3 and MLKL increased(P<0.01) in the model group. In the EA group, the neurological deficit score was reduced(P<0.01)；HE staining showed that the pathological damage was ameliorated in the infarction area；the neuron apoptosis rate, the contents of TNF-α, IL-1β and IL-6, and the mRNA and protein expressions of RIP1, RIP3, MLKL decreased(P<0.05, P<0.01) when compared with those in the model group. EA can attenuate cerebral ischemia reperfusion injury and display its neuroprotective effect probably through inhibiting programmed necrosis of cerebral cortical neurons in the rats.

A case of left middle cerebral artery occlusion during catheter ablation for paroxysmal ventricular tachycardia

A case of left middle cerebral artery occlusion during catheter ablation for paroxysmal ventricular tachycardia

Mechanical thrombectomy for acute left middle cerebral artery occlusion in a patient with mirror- image dextrocardia

Mirror-image dextrocardia is a physiological variant in which the heart is located in a mirror position to the right of the position of the normal human heart. Mirror-image dextrocardia combined with acute large-artery occlusive stroke is extremely rare in clinical practice. We present here a 67-year- old woman with complete blockage in her left middle cerebral artery. The patient also had a mirror- image dextrocardia. In this report, we share our experience in treating the patient using mechanical thrombectomy. During her visit to the emergency department, we performed various tests to understand the patient’s anatomy. Based on the findings, we decided to approach the femoral artery. Using a combination of stent thrombectomy and intermediate catheter aspiration, we successfully restored blood flow to the patient’s left middle cerebral artery.

Protein misfolding: an additional player in the stroke-heart syndrome

Abstract Background Patients suffering from acute ischemic stroke experience an increased risk of major adverse cardiovascular events, introducing the term of stroke-heart syndrome (SHS). Beside common risk factors, the so-called brain-heart axis represents a relevant yet not fully understood biological matrix driving this multi-organ condition. Together with inflammatory and neurohormonal signals, protein misfolding appears as an additional component of this matrix. In fact, previous studies employing animal models of cerebral ischemia identified wrongly arranged toxic proteins (oligomers). In light of the spreading capabilities of such proteins, we questioned whether protein misfolding plays a role in the SHS. Purpose The purpose of this study is to investigate the occurrence of protein misfolding in the post-stroke cardiac dysfunction by assessing presence, origin, localization and routes of oligomers in the heart following an acute ischemic stroke. Its biological and physiological relevance are evaluated by in vivo and in vitro assessments of the myocardium. Methods Acute cerebral ischemic injury was induced in the mouse by left transient middle cerebral artery occlusion for 45 minutes followed by 48 hours of reperfusion in 3-4 month-old C57BL/6J wild type males. Sham operated littermate mice were used as controls. Forty-eight hours after acute cerebral ischemia, cardiac function was evaluated by electrocardiography and compared to pre-operative assessment. Organs were harvested after the abovementioned assessment for the localization and semi-quantification of oligomers in heart and lymph nodes. Furthermore, biological responses related to protein homeostasis in the myocardium were assessed on mRNA and protein levels. Results Our preliminary results show that acute ischemic stroke is associated with an increased presence of oligomers in the heart. In addition, higher levels of oligomers were detected in axillary lymph nodes isolated from stroke mice, suggesting a possible route of oligomers spreading (Fig 1A). Correlating with oligomers occurrence, molecular analyses showed significant upregulation of the inositol-requiring enzyme 1 (IRE1), and catalase at mRNA level (Fig 1B). On the other hand, the expression of the 78-kDa glucose-regulated protein (GRP78), and catalase significantly decreased at protein level, indicating impaired myocardial protein quality control and oxidative stress after acute ischemic stroke (Fig 1C). Stroke-induced cardiac dysfunction was presented by decreased heart weight to tibia length ratio as well as slower and irregular heart rhythm suggesting signs of arrhythmia (Fig 2). Conclusions Acute ischemic stroke is associated with an increased oligomers occurrence in the myocardium and ultimately correlates with altered cardiac resistance against proteotoxicity. Further experiments will be conducted in order to elucidate the role of oligomers as active players or bystanders in the stroke-heart syndrome.

Abstract 17085: An Unusual Case of Severe Hypertrophic Cardiomyopathy in a 23-Year-Old Systemic Lupus Erythematosus Patient on Hydroxychloroquine

A 23-year-old female with Systemic lupus erythematosus (SLE), lupus nephritis, antiphospholipid syndrome, venous thromboembolism, stroke, Libman-Sacks endocarditis, and hypertension presented with right upper and lower extremity weakness, right facial droop, and aphasia. Her home medications included hydroxychloroquine, mycophenolate, apixaban, and losartan. ECG showed normal sinus rhythm, left atrial enlargement, ST and T wave abnormalities in V5 and V6. Computed tomography angiography of the brain showed left middle cerebral artery occlusion. Transthoracic echocardiogram (TTE) showed left ventricular ejection fraction of 65%, severe left ventricular hypertrophy, moderate pericardial effusion, and moderately thickened mitral valve (MV) leaflets. Transesophageal echocardiogram showed large vegetations on atrial aspect of both MV leaflets concerning for Libman-Sacks endocarditis. We attempt to investigate the cause of this hypertrophic cardiomyopathy (HCM) in a young patient with SLE. Few reported cases of HCM in patients with SLE were medication induced. Tacrolimus has been observed to induced HCM in a Japanese patient with dermatomyositis. Hydroxychloroquine has been associated with myocardial thickening. Its use can lead to enlarged myocardiocytes with intracytoplasmic vacuoles consisting of concentric lamellar myelin figures in single membrane bound vesicles, curvilinear bodies, glycogen accumulation and fused mitochondria. Hydroxychloroquine use led to reversible inhibition of lysosomal enzyme activity. Cessation of medication use in both cases led to reduction in left ventricle thickness. These patients, like our own, has no family history of aortic valve stenosis, mitral valve prolapse, or HCM. However, this patient’s use of hydroxychloroquine to treat her SLE can be assumed to be a contributing factor to her HCM. This could suggest possible screening with ECG and TTE in patients taking hydroxychloroquine.

Leucine Reduced Blood-Brain Barrier Disruption and Infarct Size in Early Cerebral Ischemia-Reperfusion.

A disruption of the blood-brain barrier (BBB) is a crucial pathophysiological change that can impact the outcome of a stroke. Ribosomal protein S6 (S6) and protein kinase B (Akt) play significant roles in early cerebral ischemia-reperfusion injury. Studies have suggested that branched-chain amino acids (BCAAs) may have neuroprotective properties for spinal cord or brain injuries. Therefore, we conducted research to investigate if leucine, one of the BCAAs, could offer neuroprotection and alter BBB disruption, along with its effects on the phosphorylation of S6 and Akt during the early phase of cerebral ischemia-reperfusion, specifically within the thrombolytic therapy time window. In rats, ten min after left middle cerebral artery occlusion (MCAO), 5 µL of 20 mM L-leucine or normal saline was injected into the left lateral ventricle. After two hours of reperfusion following one hour of MCAO, we determined the transfer coefficient (Ki) of 14C-α-aminoisobutyric acid to assess the BBB disruption, infarct size, and phosphorylation of S6 and Akt. Ischemia-reperfusion increased the Ki (+143%, p < 0.001) and the intra-cerebroventricular injection of leucine lowered the Ki in the ischemic-reperfused cortex (-34%, p < 0.001). Leucine reduced the percentage of cortical infarct (-42%, p < 0.0001) out of the total cortical area. Ischemia-reperfusion alone significantly increased the phosphorylation of both S6 and Akt (p < 0.05). However, the administration of leucine had no further effect on the phosphorylation of S6 or Akt in the ischemic-reperfused cortex. This study suggests that an acute increase in leucine levels in the brain during early ischemia-reperfusion within a few hours of stroke may offer neuroprotection, possibly due to reduced BBB disruption being one of the major contributing factors. Leucine did not further increase the already elevated phosphorylation of S6 or Akt by ischemia-reperfusion under the current experimental conditions. Our data warrant further studies on the effects of leucine on neuronal survival and its mechanisms in the later stages of cerebral ischemia-reperfusion.

Collateral circulation status-guided mechanical thrombectomy in pediatric stroke with an extended ghost infarct core: illustrative case.

Mechanical thrombectomy (MT) has been proved to be a highly effective therapy to treat acute ischemic stroke due to large vessel occlusion. Often, the ischemic core extent on baseline imaging is an important determinant for endovascular treatment eligibility. However, computed tomography (CT) perfusion (CTP) or diffusion-weighted imaging may overestimate the infarct core on admission and, consequently, smaller infarct lesions called "ghost infarct cores." A 4-year-old, previously healthy boy presented with acute-onset, right-sided weakness and aphasia. Fourteen hours after the onset of symptoms, the patient presented with a National Institutes of Health Stroke Scale (NIHSS) score of 22, and magnetic resonance angiography demonstrated a left middle cerebral artery occlusion. MT was not considered because of a large infarct core (infarct core volume: 52 mL; mismatch ratio 1.6 on CTP). However, multiphase CT angiography indicated good collateral circulation, which encouraged MT. Complete recanalization was achieved via MT at 16 hours after the onset of symptoms. The child's hemiparesis improved. Follow-up magnetic resonance imaging was nearly normal and showed that the baseline infarct lesion was reversible, in agreement with neurological improvement (NIHSS score 1). The selection of pediatric stroke with a delayed time window guided by good collateral circulation at baseline seems safe and efficacious, which suggests a promising value of vascular window.

Teaching NeuroImages: An uncommon cause of carotid artery dissection

Cervical internal carotid artery dissection (CAD), a leading cause of ischemic stroke in young adults, has been rarely associated with Fabry disease (FD).1,2 A 49-year-old man with left acute middle cerebral artery occlusion due to underlying spontaneous CAD received IV thrombolysis and mechanical thrombectomy, achieving complete reperfusion (figure 1).

Ca2+ -dependent activator protein for secretion 1 promotes spontaneous recovery in ischemic stroke by regulating BDNF secretion.

Ischemic stroke triggers a cascade of events that facilitates neural protection and spontaneous recovery, which accounts for a major part of functional recovery. Despite the cellular and molecular facilitations on neural protection, the molecular mechanisms of spontaneous recovery have not been fully understood. Ca2+ -dependent activator protein for secretion 1 (CAPS1), a member of CAPS family, plays a major role in synaptic transmission and synaptic effectiveness by regulating vesicle exocytosis. Here, the molecular mechanism of CAPS1 in spontaneous recovery after ischemic stroke was studied. In this study, transient left middle cerebral artery occlusion (MCAO) was used as the ischemic stroke model. The whole brain magnetic resonance imaging (MRI) and neurological score analysis showed decreased infarct volume and neurological scores at 7 days as compared with 1day after MCAO, suggesting the spontaneous recovery. Elisa and Western blot analysis showed elevated BDNF and CAPS1 expression levels in bilateral hippocampus at both 1day and 3 days after MCAO. Then, inhibition of CAPS1 by adeno-associated virus (AAV) microinjection in the hippocampus attenuated the spontaneous recovery of both motor and memory impairment induced by MCAO. In addition, elevated p-TrkB levels were detected after MCAO, which were reduced by CAPS1-AAV microinjection, indicating that CAPS1 could induce BDNF secretion after ischemic stroke. Moreover, we found elevated combination of CAPS1 with dense core vesicles (DCV) in the hippocampus at both 1day and 3 days after MCAO, which could also be inhibited by CAPS1-AAV microinjection, indicating the potential mechanism of CAPS1 in regulating BDNF release after MCAO. Finally, we found that CAPS1/BDNF signaling could influence the neurogenesis in the hippocampus after MCAO. In conclusion, CAPS1 regulates neurogenesis by up-regulating BDNF release in the hippocampus, which finally facilitate spontaneous recovery after ischemic stroke.

Abstract Number ‐ 218: Mechanical Thrombectomy in a HIV Patient with Staphylococcus Lugdunensis Bacteremia: A Case Report.

Introduction Occlusion of cerebral arteries account for 40–50% of neurological complications of infective endocarditis with the emboli most commonly lodging in the middle cerebral artery. The management of these occlusions with the use of thrombolytic therapies are associated with intracranial hemorrhage whereas outcomes with endovascular thrombectomy, while still under investigation, appear to be more favorable. In this case report, we present a HIV patient with persistent staphylococcus lugdunenesis bacteremia of unknown origin and acute left middle cerebral artery occlusion, who underwent endovascular thrombectomy. Methods Case Report Results A 66‐year‐old male past medical history of HIV on Elvitegravir/Cobicistat/Emtricitabine/ Tenofovir, pancytopenia and treated hepatitis C who presented for malaise, back pain, and urinary symptoms for 1 week. Initial labs remarkable for pancytopenia, CD4 count 44 and positive urinalysis. Ceftriaxone was started for UTI and Trimethoprim/Sulfamethoxazole for PJP prophylaxis. Urine and multiple blood cultures were positive for staphylococcus lugdunensis. Vancomycin was added to antibiotic therapy. On day two of hospitalization, patient developed new onset aphasia, right facial droop, and right hemiparesis. Upon evaluation, NIHSS was 14. CT head was negative. CTA head and neck showed left M1 occlusion. CT perfusion showed an infarct core of 20cc and 144cc of penumbra. Due to concern for possible infective endocarditis, thrombolytics were not administered but he was taken for thrombectomy. Emboli retrieval was successful with mTICI‐2c reperfusion. During thrombectomy, clot noted to have septic emboli appearance. Post thrombectomy, patient had complete resolution of neurological deficits. MRI brain showed multiple punctate foci of restricted diffusion in the left middle cerebral artery distribution consistent with embolic process. TTE was inconclusive. Intraoperative cultures of the clot resulted positive for staphylococcus lugdunensis and pathology examination detailed clot with bacterial colonization. TEE was performed and negative for valvular vegetations, mass, thrombus, or endocarditis but there was an intrapulmonary shunt. Patient later developed a small acute left parietal lobe parenchymal hematoma and basal ganglia infarct. His neurological status remained unchanged. He completed 6 weeks of IV antibiotic therapy upon discharge. Conclusions This case illustrates the importance of timely endovascular thrombectomy in suspected cerebral septic emboli as outcomes are favorable. It supports prompt recognition of septic emboli bacterial species for targeted antibiotic therapy along with further investigation into staphylococcus lugdunensis and its relation with cerebral septic emboli. This case urges additional exploration into the relationship between HIV patients and cerebrovascular disease including cerebral septic emboli.

Parallel stent retriever mechanical thrombectomy of an acute internal carotid artery occlusion refractory to standard techniques: A case report

Although mechanical thrombectomy for acute large vessel occlusion is generally effective, some occlusions are refractory. We report a patient in whom the parallel stent retriever technique using two Trevo stent retrievers (Stryker Neurovascular, Fremont, California, USA) was required to treat an intracranial and epidural internal carotid artery occlusion after other techniques had failed. A 68-year-old woman presented with an acute left internal carotid artery occlusion 4 days after mechanical thrombectomy of a left middle cerebral artery occlusion. She was not a candidate for intravenous thrombolysis because of a recent cerebral infarction. Attempts at mechanical thrombectomy using a stent retriever, contact aspiration, or combined contact aspiration and stent retriever were unsuccessful. The parallel stent retriever technique using two 6 × 25-mm Trevo stent retrievers enabled coverage of the entire thrombus, and successful reperfusion was achieved (extended Thrombolysis in Cerebral Infarction grade 2b). After the procedure, the patient was able to walk without assistance. Her modified Rankin Scale score was 2 at 90 days follow-up. Microscopic examination of the retrieved thrombi demonstrated red blood cells, fibrin, and partial endothelialization. The parallel Trevo stent retriever technique has the potential as rescue therapy for refractory large-vessel occlusion. However, complications arising from this technique remain uncertain. Further studies are needed to determine the effect of this technique in terms of recanalization and clinical safety.

Effects of different remote ischemia perconditioning methods on cerebral infarct volume and neurological impairment in rats

Remote ischemic perconditioning (RIPerC) is a novel neuroprotective method against cerebral infarction that has shown efficacy in animal studies but has not been consistently neuroprotective in clinical trials. We focused on the temporal regulation of ischemia–reperfusion by RIPerC to establish an optimal method for RIPerC. Rats were assigned to four groups: 10 min ischemia, 5 min reperfusion; 10 min ischemia, 10 min reperfusion; 5 min ischemia, 10 min reperfusion; and no RIPerC. RIPerC interventions were performed during ischemic stroke, which was induced by a 60-min left middle cerebral artery occlusion. Infarct volume, sensorimotor function, neurological deficits, and cellular expressions of brain-derived neurotrophic factor (BDNF), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and caspase 3 were evaluated 48 h after the induction of ischemia. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) was also performed. RIPerC of 10 min ischemia/10 min reperfusion, and 5 min ischemia/10 min reperfusion decreased infarct volume, improved sensorimotor function, decreased Bax, caspase 3, and TUNEL-positive cells, and increased BDNF and Bcl-2 expressions. Our findings suggest RIPerC with a reperfusion time of approximately 10 min exerts its neuroprotective effects via an anti-apoptotic mechanism. This study provides important preliminary data to establish more effective RIPerC interventions.

The Role of the Dopamine System in Post-Stroke Mood Disorders in Newborn Rats.

Post-stroke mood disorders (PSMD) affect disease prognosis in adults. Adult rodent models underlie the importance of the dopamine (DA) system in PSMD pathophysiology. There are no studies on PSMD after neonatal stroke. We induced neonatal stroke in 7-day-old (P7) rats by temporal left middle cerebral artery occlusion (MCAO). Performance in the tail suspension test (TST) at P14 and the forced swimming test (FST) and open field test (OFT) at P37 were studied to assess PSMD. DA neuron density in the ventral tegmental area, brain DA concentration and DA transporter (DAT) expression as well as D2 receptor (D2R) expression and G-protein functional coupling were also studied. MCAO animals revealed depressive-like symptoms at P14 associated with decreased DA concentration and reduced DA neuron population and DAT expression. At P37, MCAO rats showed hyperactive behavior associated with increased DA concentration, normalization of DA neuron density and decreased DAT expression. MCAO did not modify D2R expression but reduced D2R functionality at P37. MCAO-induced depressive-like symptoms were reversed by the DA reuptake inhibitor GBR-12909. In conclusion, MCAO in newborn rats induced depressive-like symptoms and hyperactive behavior in the medium and long term, respectively, that were associated with alterations in the DA system.

Immediate Angioscopic Investigation After Cerebral Artery Thrombectomy Revealed Aortogenic Cerebral Infarction

Background Aortogenic embolism is one of the causes of embolic stroke of undetermined source, which can be difficult to diagnose. Methods We present the case of a 74‐year‐old male patient with a history of Bentall surgery and thoracic endovascular aortic repair who was transported to our hospital with sudden‐onset right‐sided hemiplegia and total aphasia. Magnetic resonance imaging revealed an acute left middle cerebral artery occlusion. Subsequently, an emergency mechanical thrombectomy was performed, through which the left middle cerebral artery was partially reperfused. We immediately investigated the aorta using an angioscopy. Results The angioscopy revealed a thrombus attached to an artificial blood vessel of the aorta close to the origin of the left common carotid artery. Because no other source of the embolus could be identified using electrocardiography or ultrasound, we diagnosed an aortogenic cerebral infarction by combining these findings with the pathological findings of the collected thrombus. Conclusions This is the first report that aortogenic cerebral infarction could be diagnosed using an angioscopy immediately after a cerebral artery thrombectomy.

Changes in ultrasonic vocalizations after unilateral cerebral ischemia in a rat stroke model

Stroke frequently results in communication impairments that negatively impact quality of life and overall recovery, yet the biological mechanisms underlying these changes are not well understood. Ultrasonic vocalizations (USVs) in rodent models of disease and aging have been used to improve our understanding of the biological mechanisms that underlie vocal deficits and their response to interventions. Changes in USVs after middle cerebral artery occlusion (MCAO) in mice have been reported, yet rat models have significant anatomical and behavioral advantages over mice, including the ability to vocally train rats with an established paradigm. We sought to determine whether a unilateral MCAO rat stroke model provides a biologically and behaviorally relevant way to study post stroke vocalization deficits. We hypothesized that left MCAO would be associated with changes in USVs. Six weeks after MCAO or sham-control surgery, USVs were recorded in rats using an established mating paradigm. Stroke was associated with differences in USV acoustics including more frequent use of simple calls characterized by shorter durations and restricted bandwidths. These parameters were also found to correlate with post stroke lingual weakness. This is the first study to describe changes to rat USVs using a stroke model. These results suggest the unilateral MCAO rat stroke model is a biologically and behaviorally relevant model to understand how stroke affects vocal behaviors.

Effects of electroacupuncture on rats with cognitive impairment: An iTRAQ-based proteomics analysis

ObjectiveThe study explores the effects of electroacupuncture (EA) at the governing vessel (GV) on proteomic changes in the hippocampus of rats with cognitive impairment. MethodsHealthy male rats were randomly divided into 3 groups: sham, model and EA. Cognitive impairment was induced by left middle cerebral artery occlusion in the model and EA groups. Rats in the EA group were treated with EA at Shenting (GV24) and Baihui (GV20) for 7 d. Neurological deficit was scored using the Longa scale, the learning and memory ability was detected using the Morris water maze (MWM) test, and the proteomic profiling in the hippocampus was analyzed using protein-labeling technology based on the isobaric tag for relative and absolute quantitation (iTRAQ). The Western blot (WB) analysis was used to detect the proteins and validate the results of iTRAQ. ResultsCompared with the model group, the neurological deficit score was significantly reduced, and the escape latency in the MWM test was significantly shortened, while the number of platform crossings increased in the EA group. A total of 2872 proteins were identified by iTRAQ. Differentially expressed proteins (DEPs) were identified between different groups: 92 proteins were upregulated and 103 were downregulated in the model group compared with the sham group, while 142 proteins were upregulated and 126 were downregulated in the EA group compared with the model group. Most of the DEPs were involved in oxidative phosphorylation, glycolipid metabolism and synaptic transmission. Furthermore, we also verified 4 DEPs using WB technology. Although the WB results were not exactly the same as the iTRAQ results, the expression trends of the DEPs were consistent. The upregulation of heat-shock protein β1 (Hspb1) was the highest in the EA group compared to the model group. ConclusionEA can effect proteomic changes in the hippocampus of rats with cognitive impairment. Hspb1 may be involved in the molecular mechanism by which acupuncture improves cognitive impairment.

Large vessel occlusions requiring repeated mechanical thrombectomy caused by silent myocardial infarction in a young adult

ObjectivesSilent myocardial ischemia, defined as objective evidence of myocardial ischemia without symptoms, is associated with ischemic stroke. Nevertheless, silent myocardial infarction is a rare cause of ischemic stroke, especially in young adults with no medical history. Materials and methodsHerein, we report a young adult patient with acute ischemic stroke treated with repeated mechanical thrombectomy for recurrent large vessel occlusions caused by left ventricular thrombus following a silent myocardial infarction. ResultsA 40-year-old man was transferred by ambulance to our hospital because of a generalized seizure. He was diagnosed with cerebral infarction and left middle cerebral artery occlusion. We performed intravenous thrombolysis and mechanical thrombectomy. Recanalization was achieved and his symptoms gradually improved. However, the day after treatment he developed bilateral cerebellar infarction and basilar artery occlusion. We performed a second mechanical thrombectomy and recanalization was achieved. Transthoracic echocardiography revealed a mobile left ventricular thrombus. Although he had no previous chest symptomatic episodes, cardiac examination confirmed myocardial infarction of unknown onset. He was diagnosed with acute ischemic stroke with large vessel occlusions caused by left ventricular thrombus following a silent myocardial infarction. Anticoagulation therapy reduced the amount of thrombus. At 1-year follow-up, he had not experienced any recurrences or symptoms. ConclusionsSilent myocardial infarction should be considered a cause of ischemic stroke in young adults, even without any vascular risk factors. Recurrent large vessel occlusion may occur in patients with left ventricular thrombus, and repeated mechanical thrombectomy should be considered for treatment.

Targeting 17β-estradiol biosynthesis in neural stem cells improves stroke outcome.

Dax-1 (dosage-sensitive sex reversal adrenal hypoplasia congenital region on X-chromosome gene 1) blocks 17β-estradiol biosynthesis and its knockdown would be expected to increase 17β-estradiol production. We hypothesized that knockdown of Dax-1 in a conditionally immortalized neural stem cell (NSC) line, MHP36, is a useful approach to increase 17β-estradiol production. Short hairpin (sh) RNA targeted to Dax-1 in NSCs, namely MHP36-Dax1KD cells, resulted in the degradation of Dax-1 RNA and attenuation of Dax-1 protein expression. In vitro, MHP36-Dax1KD cells exhibited overexpression of aromatase and increased 17β-estradiol secretion compared to MHP36 cells. As 17β-estradiol has been shown to promote the efficacy of cell therapy, we interrogated the application of 17β-estradiol-enriched NSCs in a relevant in vivo disease model. We hypothesized that MHP36-Dax1KD cells will enhance functional recovery after transplantation in a stroke model. C57BL/6 male adult mice underwent ischemia/reperfusion by left middle cerebral artery occlusion for 45 min using an intraluminal thread. Two days later male mice randomly received vehicle, MHP36 cells, MHP36-Dax1KD cells, and MHP36 cells suspended in 17β-estradiol (100 nm) or 17β-estradiol alone (100 nm) with serial behavioral testing over 28 days followed by post-mortem histology and blinded analysis. Recovery of sensorimotor function was accelerated and enhanced, and lesion volume was reduced by MHP36-Dax1KD transplants. Regarding mechanisms, immunofluorescence indicated increased synaptic plasticity and neuronal differentiation after MHP36-Dax1KD transplants. In conclusion, knockdown of Dax-1 is a useful target to increase 17β-estradiol biosynthesis in NSCs and improves functional recovery after stroke in vivo, possibly mediated through neuroprotection and improved synaptic plasticity. Therefore, targeting 17β-estradiol biosynthesis in stem cells may be a promising therapeutic strategy for enhancing the efficacy of stem cell-based therapies for stroke.

0127 Brain bacterial peptidoglycan is region-specific and changes after ischemic stroke

Abstract Introduction Sleep disorders and ischemic stroke (IS) are large health burdens. Almost half the USA population reports disturbed sleep and 795,000 Americans suffer a stroke annually. Despite dysregulated sleep being a stroke risk factor that can exacerbate injury and prolong recovery, sleep deprivation immediately preceding experimental stroke is neuroprotective. Bacteria and microbial products associate with (patho-)physiologies, including sleep phenotypes and IS. Peptidoglycans (PGs) are bacterial cell wall components found in diseased and healthy adults, and in developing and sleep-deprived brains. Although they influence atherosclerosis, an IS risk factor, PGs have not been characterized in post-stroke brain. Methods Aged (63 weeks) male wildtype mice (n=5) underwent permanent left middle cerebral artery occlusion, a model that mimics atherosclerotic IS, the most common type in humans. Surgeries began at Zeitgeber time (ZT) 12, lasted 30-40 minutes, and were followed by a 2-2.5-hour recovery period before sacrifice at ZT15. Brain stem (BS), somatosensory and prefrontal cortices (Sctx, PFC) were dissected, homogenized in phosphate buffered saline, and centrifuged. A standardized murine peptidoglycan ELISA (MyBioSource) was used for PG/MP quantification in resultant supernates. Brain areas in the left (L) IS, and right (R) control, hemispheres were compared by two-way ANOVA and Tukey’s HSD tests. Results Mean PG values are expressed as ng/mg tissue wet weight ± SEM. Post-IS PG in the injured L Sctx (4.28±0.48) was lower (F(2,21)=49.29, p&amp;lt;0.05) than the uninjured R Sctx (5.66±0.29; p=0.048). There were no hemispheric PG differences in either BS or PFC. L hemispheric PG was greater in BS (7.59±0.40) versus Sctx (p=0.0008) and PFC (3.82±0.21, p=0.0002). R hemispheric PG was also greater in BS (8.26±0.53) versus Sctx (p=0.005) and PFC (3.56±0.56, p=0.0006) and in Sctx versus PFC (p=0.02). Conclusion This study confirms our parallel study, presented in a separate abstract herein (English et al), that PG regulation is unique within brain areas. Additionally, PG values in uninjured Sctx and in BS were similar between studies. Finally, current results suggest that reduced cerebral blood flow induced by IS reduces PG in the affected brain area. Further, PG may have a role in sleep deprivation-related IS injury and recovery. Support (If Any) W.M. Keck Foundation and NIH (NS025378)