TBC1Domain Family Member 25 deficiency aggravates cerebral ischemia-reperfusion injury via TAK1-JNK/p38 pathway.

TBC1Domain Family Member 25 (TBC1D25) is a protein that contains a TBC/RAB-GTPase activating protein (GAP) domain, which was shown to participate in autophagy in previous studies. However, the role of TBC1D25 in cerebral ischemia-reperfusion (I/R) injury remains unknown. In this study, we found that the mRNA and protein expression levels of TBC1D25 decreased in mouse brain after I/R injury and primary cortical neurons treated with oxygen and glucose deprivation/reoxygenation (OGD/R). Then TBC1D25 knockout (KO) mice were applied to demonstrate that TBC1D25 ablation aggravated cerebral I/R-induced neuronal loss and infarct size. In addition, neuronal apoptosis and inflammation were significantly potentiated in the TBC1D25-KO group. In in vitro OGD/R model, TBC1D25 knockdown can attenuate neuronal cell viability and aggravate the process of inflammation and apoptosis. Conversely, over-expression of TBC1D25 in primary neurons ameliorated the aforementioned processes. Mechanistically, RNA-sequencing (RNA-seq) analysis revealed mitogen-activated protein kinase (MAPK) signaling pathway was the most significant pathway that contributed to TBC1D25-mediated brain I/R injury process. Through experimental verification, TBC1D25 deficiency increased the phosphorylation of the transforming growth factor-ß-activated kinase 1 (TAK1)-c-Jun N-terminal kinase (JNK)/p38 axis in neurons during the brain I/R injury. Furthermore, we found that TAK1 blockade abrogated the apoptosis and inflammatory response produced by TBC1D25 knockdown in vitro. In conclusion, this study is the first to demonstrate the functional significance of TBC1D25 in the pathophysiology of brain I/R injury, and the protective mechanism of TBC1D25 is dependent on the TAK1-JNK/p38 pathway.

Ovariectomy Reduces Vasocontractile Responses of Rat Middle Cerebral Arteries After Focal Cerebral Ischemia.

ABSTRACT: Effects of sex hormones on stroke outcome are not fully understood. A deleterious consequence of cerebral ischemia is upregulation of vasoconstrictor receptors in cerebral arteries that exacerbate stroke injury. Here, we tested the hypothesis that female sex hormones alter vasocontractile responses after experimental stroke in vivo or after organ culture in vitro, a model of vasocontractile receptor upregulation. Female rats with intact ovaries and ovariectomized (OVX) females treated with 17ß-estradiol, progesterone, or placebo were subjected to transient, unilateral middle cerebral artery occlusion followed by reperfusion (I/R). The maximum contractile response, measured my wire myography, in response to the endothelin B receptor agonist sarafotoxin 6c was increased in female arteries after I/R, but the maximum response was significantly lower in arteries from OVX females. Maximum contraction mediated by the serotonin agonist 5-carboxamidotryptamine was diminished after I/R, with arteries from OVX females showing a greater decrease in maximum contractile response. Contraction elicited by angiotensin II was similar in all arteries. Neither estrogen nor progesterone treatment of OVX females affected I/R-induced changes in endothelin B- and 5-carboxamidotryptamine-induced vasocontraction. These findings suggest that sex hormones do not directly influence vasocontractile alterations that occur after ischemic stroke; however, loss of ovarian function does impact this process.

Transcranial Doppler 6 h after Successful Reperfusion as a Predictor of Infarct Volume.

OBJECTIVES: The aim of the study is to analyze the hemodynamic changes in the middle cerebral artery (MCA) after endovascular revascularization in acute ischemic stroke (AIS) due to large vessel occlusion and its association with the infarct volume size in the control head CT. MATERIALS AND METHODS: Prospective study of patients with AIS due to internal carotid artery terminus or M1 segment of the MCA occlusion, who underwent endovascular treatment with a final TICI 2b-3 score, without concomitant stenosis ≥50% in both cervical carotid arteries. Transcranial Doppler ultrasound (TCD) of both MCAs was carried out at 6 h after the endovascular procedure. Mean flow velocities (MFV) after arterial reperfusion and its association with the infarct volume size in 24-36 h control head CT were determined. RESULTS: 91 patients (51 women) were included with a median age of 78 years and National institute of Health Stroke Scale of 18. The MCA was occluded in 76.92%, and intravenous thrombolysis was administered in 40.7%. The incidence of symptomatic intracranial hemorrhage was 5.5%. At three months, mortality was 19.8% and a 52.7% of patients achieved functional independence (modified Rankin Scale 0-2). After a multivariable logistic regression analysis, an increase in the MFV greater than 50% at 6 h in the treated MCA compared to contralateral MCA, was an independent predictor of large infarct volume in the control head CT with an OR 9.615 (95%CI: 1.908-47.620), p=0.006 CONCLUSIONS: Increased MFV assessed by TCD examination following endovascular recanalization is independently associated with larger infarct volume.

Impaired vessel relaxation response and increased infarct size in smooth muscle cannabinoid receptor 1 knockout mice.

Cannabinoids are reported to regulate cardiovascular functions. Cannabinoid receptors 1 (CB1Rs) are widely expressed in both the neuronal system and vascular system, but the contribution of CB1Rs in vascular smooth muscle (CB1RSM) to cardiovascular functions is not clear yet. In this research, we analyzed the effects of CB1RSM on blood pressure, vasoconstriction, and vasodilation abilities by using conditionally CB1R knockout mice (CB1RSMKO). The results show no significant difference in basal blood pressure between the conscious CB1RSMKO and control mice, indicating that CB1RSM is not essential for basal blood pressure maintenance. The constriction of the CB1RSMKO mesenteric artery in vitro was not significantly altered compared with that of the control mice. In contrast, the relaxation to CB1R agonist 2-AG or WIN55212-2 was decreased in CB1RSMKO vessels, suggesting that activation of CB1RSM mediates the vasodilation effect of cannabinoids. Ischemia stroke mouse model was used to further identify the potential function of CB1RSM in pathological conditions, and the results showed that the infarct volume in CB1RSMKO mice is significantly increased compared with the control littermates. These results suggest that vascular CB1R may not play a central role in basal vascular health maintenance but is protective in ischemia states, such as stroke. The protection function may be mediated, at least partly, by the relaxation effect of CB1RSM-dependent activities of endocannabinoids.

Hypoxic postconditioning promotes neurogenesis by modulating the metabolism of neural stem cells after cerebral ischemia.

Ischemic stroke is one of the most lethal and severely disabling diseases that seriously affects human health and quality of life. The maintenance of self-renewal and differentiation of neural stem cells are closely related to metabolism. This study aimed to investigate whether hypoxic postconditioning (HPC) could promote neurogenesis after ischemic stroke, and to investigate the role of neuronal stem cell metabolism in HPC-induced neuroprotection. Male C57BL/6 mice were subjected to transient middle cerebral artery occlusion (MCAO), and HPC was performed for 3 h per day. Immunofluorescence staining was used to assess neurogenesis. The cell line NE-4C was used to elucidate the proliferation of neuronal stem cells in 21% O2 or 8% O2. HPC promoted the recovery of neurological function in mice on day 14. HPC promoted neuronal precursor proliferation in the subventricular zone (SVZ) on day 7 and enhanced neuronal precursor migration in the basal ganglia and cortex on day 14. Fatty acid oxidation (FAO) and glycolysis of neural stem cells in the SVZ changed after MCAO with or without HPC. HPC promoted the proliferation of NE-4C stem cells, decreased FAO and increased glycolysis. All these beneficial effects of HPC were ablated by the application of an FAO activator or a glycolysis inhibitor. In conclusion, cerebral ischemia modulated the FAO and glycolysis of neural stem cells. HPC promoted the proliferation and migration of neural stem cells after MCAO, and these effects may be related to the regulation of metabolism, including FAO and glycolysis.

Diet-induced weight loss in obese/diabetic mice normalizes glucose metabolism and promotes functional recovery after stroke.

BACKGROUND: Post-stroke functional recovery is severely impaired by type 2 diabetes (T2D). This is an important clinical problem since T2D is one of the most common diseases. Because weight loss-based strategies have been shown to decrease stroke risk in people with T2D, we aimed to investigate whether diet-induced weight loss can also improve post-stroke functional recovery and identify some of the underlying mechanisms. METHODS: T2D/obesity was induced by 6 months of high-fat diet (HFD). Weight loss was achieved by a short- or long-term dietary change, replacing HFD with standard diet for 2 or 4 months, respectively. Stroke was induced by middle cerebral artery occlusion and post-stroke recovery was assessed by sensorimotor tests. Mechanisms involved in neurovascular damage in the post-stroke recovery phase, i.e. neuroinflammation, impaired angiogenesis and cellular atrophy of GABAergic parvalbumin (PV)+ interneurons were assessed by immunohistochemistry/quantitative microscopy. RESULTS: Both short- and long-term dietary change led to similar weight loss. However, only the latter enhanced functional recovery after stroke. This effect was associated with pre-stroke normalization of fasting glucose and insulin resistance, and with the reduction of T2D-induced cellular atrophy of PV+ interneurons. Moreover, stroke recovery was associated with decreased T2D-induced neuroinflammation and reduced astrocyte reactivity in the contralateral striatum. CONCLUSION: The global diabetes epidemic will dramatically increase the number of people in need of post-stroke treatment and care. Our results suggest that diet-induced weight loss leading to pre-stroke normalization of glucose metabolism has great potential to reduce the sequelae of stroke in the diabetic population.

Role of TLR4 in Neutrophil Dynamics and Functions: Contribution to Stroke Pathophysiology.

Background and Purpose: The immune response subsequent to an ischemic stroke is a crucial factor in its physiopathology and outcome. It is known that TLR4 is implicated in brain damage and inflammation after stroke and that TLR4 absence induces neutrophil reprogramming toward a protective phenotype in brain ischemia, but the mechanisms remain unknown. We therefore asked how the lack of TLR4 modifies neutrophil function and their contribution to the inflammatory process. Methods: In order to assess the role of the neutrophilic TLR4 after stroke, mice that do not express TLR4 in myeloid cells (TLR4loxP/Lyz-cre) and its respective controls (TLR4loxP/loxP) were used. Focal cerebral ischemia was induced by occlusion of the middle cerebral artery and infarct size was measured by MRI. A combination of flow cytometry and confocal microscopy was used to assess different neutrophil characteristics (circadian fluctuation, cell surface markers, cell complexity) and functions (apoptosis, microglia engulfment, phagocytosis, NETosis, oxidative burst) in both genotypes. Results: As previously demonstrated, mice with TLR4 lacking-neutrophils had smaller infarct volumes than control mice. Our results show that the absence of TLR4 keeps neutrophils in a steady youth status that is dysregulated, at least in part, after an ischemic insult, preventing neutrophils from their normal circadian fluctuation. TLR4-lacking neutrophils showed a higher phagocytic activity in the basal state, they were preferentially engulfed by the microglia after stroke, and they produced less radical oxygen species (ROS) in the first stage of the inflammatory process. Conclusions: TLR4 is specifically involved in neutrophil dynamics under physiological conditions as well as in stroke-induced tissue damage. This research contributes to the idea that TLR4, especially when targeted in specific cell types, is a potential target for neuroprotective strategies.

Large-Scale Multivariate Analysis to Interrogate an Animal Model of Stroke: Novel Insights Into Poststroke Pathology.

Background and Purpose: Preclinical stroke studies endeavor to model the pathophysiology of clinical stroke, assessing a range of parameters of injury and impairment. However, poststroke pathology is complex and variable, and associations between diverse parameters may be difficult to identify within the usual small study designs that focus on infarct size. Methods: We have performed a retrospective large-scale big data analysis of records from 631 C57BL/6 mice of either sex in which the middle cerebral artery was occluded by 1 of 5 surgeons either transiently for 1 hour followed by 23-hour reperfusion (transient middle cerebral artery occlusion [MCAO]; n=435) or permanently for 24 hours without reperfusion (permanent MCAO; n=196). Analyses included a multivariate linear mixed model with random intercept for different surgeons as a random effect to reduce type I and type II errors and a generalized ordinal regression model for ordinal data when random effects are low. Results: Analyses indicated that brain edema volume was associated with infarct volume at 24 hours (ß, 0.52 [95% CI, 0.45­0.59]) and was higher after permanent MCAO than after transient MCAO (P<0.05). A more severe clinical score was associated with a greater infarct volume but not with the animal's age or edema volume. Further, a more severe clinical score was observed for a given brain infarct volume after transient MCAO versus permanent MCAO. Remarkably the animal's age, which corresponded with the period of young adulthood (6­40 weeks; equivalent to ≈18­35 years in humans), was positively associated with severity of lung infection (ß, 0.65 [95% CI, 0.42­0.88]) and negatively with spleen weight (ß, −0.36 [95% CI, −0.63 to −0.09]). Conclusions: Large-scale analysis of preclinical stroke data can provide researchers in our field with insight into relationships between variables not possible if individual studies are analyzed in isolation and has identified hypotheses for future study.

DCA Protects against Oxidation Injury Attributed to Cerebral Ischemia-Reperfusion by Regulating Glycolysis through PDK2-PDH-Nrf2 Axis.

Cerebral ischemic stroke (IS) is still a difficult problem to be solved; energy metabolism failure is one of the main factors causing mitochondrion dysfunction and oxidation stress damage within the pathogenesis of cerebral ischemia, which produces considerable reactive oxygen species (ROS) and opens the blood-brain barrier. Dichloroacetic acid (DCA) can inhibit pyruvate dehydrogenase kinase (PDK). Moreover, DCA has been indicated with the capability of increasing mitochondrial pyruvate uptake and promoting oxidation of glucose in the course of glycolysis, thereby improving the activity of pyruvate dehydrogenase (PDH). As a result, pyruvate flow is promoted into the tricarboxylic acid cycle to expedite ATP production. DCA has a protective effect on IS and brain ischemia/reperfusion (I/R) injury, but the specific mechanism remains unclear. This study adopted a transient middle cerebral artery occlusion (MCAO) mouse model for simulating IS and I/R injury in mice. We investigated the mechanism by which DCA regulates glycolysis and protects the oxidative damage induced by I/R injury through the PDK2-PDH-Nrf2 axis. As indicated from the results of this study, DCA may improve glycolysis, reduce oxidative stress and neuronal death, damage the blood-brain barrier, and promote the recovery of oxidative metabolism through inhibiting PDK2 and activating PDH. Additionally, DCA noticeably elevated the neurological score and reduced the infarct volume, brain water content, and necrotic neurons. Moreover, as suggested from the results, DCA elevated the content of Nrf2 as well as HO-1, i.e., the downstream antioxidant proteins pertaining to Nrf2, while decreasing the damage of BBB and the degradation of tight junction proteins. To simulate the condition of hypoxia and ischemia in vitro, HBMEC cells received exposure to transient oxygen and glucose deprivation (OGD). The DCA treatment is capable of reducing the oxidative stress and blood-brain barrier of HBMEC cells after in vitro hypoxia and reperfusion (H/R). Furthermore, this study evidenced that HBMEC cells could exhibit higher susceptibility to H/R-induced oxidative stress after ML385 application, the specific inhibitor of Nrf2. Besides, the protection mediated by DCA disappeared after ML385 application. To sum up, as revealed from the mentioned results, DCA could exert the neuroprotective effect on oxidative stress and blood-brain barrier after brain I/R injury via PDK2-PDH-Nrf2 pathway activation. Accordingly, the PDK2-PDH-Nrf2 pathway may play a key role and provide a new pharmacology target in cerebral IS and I/R protection by DCA.

Improvement effects of tanshinone on the impaired cognition and motor function in MCAO mice with ischemic penumbra.

This study aims to investigate the effects of tanshinone on improving the impaired cognition and motor function in MCAO model mice with ischemic penumbra. MWM test was carried out to evaluate the spatial learning and memory performance and the cognitive function of mice. The area of cerebral infarction was analyzed by immunohistochemistry. The TUNEL apoptosis detection kit was used to detect neuronal apoptosis. On the 25th day, the induction model group had lower body weight than the control group and the tanshinone treatment group; the induction model group had decreased walking deficiency and correct area escape times than the other two groups; while, tanshinone treatment group had higher movement distance, movement speed, periphery entry frequency, grooming rate, decreased center entry frequency, infarction area, apoptotic neuron number, latent escape time than induction model group; additionally, the control group had increased periphery and corner entry frequency, but decreased center entry frequency and latent escape time than the other two groups. Tanshinone can reduce neuronal damage in the ischemic penumbra after stroke, improve the integrity of white and gray matter, and restore connectivity in motor and cognitive functions, thereby supporting recovery from ischemic stroke.

Geniposide attenuates postischemic long-term potentiation via GluN2A.

N-Methyl-D-aspartate receptor (NMDAR)-induced antioxidation is a significant cause of neuronal injury after ischemic stroke. In a previous work, we verified the neuroprotective roles of geniposide during tMCAO in vivo. However, it remains unknown whether geniposide ameliorates injury to hippocampal neurons during Ischemic Long Term Potentiation (iLTP) induction in vitro. After induction of cells oxygen-glucose deprivation or hydrogen peroxide, the protection of geniposide evaluated by MTT assay and electrophysiological tests. In this study, we suggested neuronal cell apoptosis was attenuated by geniposide. Furthermore, field excitatory postsynaptic potentials (fEPSCs) following postischemic LTP were assessed by electrophysiological tests. Finally, we determined that medium and high doses of geniposide attenuated oxidative stress insult and improved iLTP. Importantly, these effects were abolished by cotreatment with geniposide and the GluN2A antagonist NVP. In contrast, the GluN2B inhibitor ifenprodil failed to have an effect. In conclusion, we suggest for the first time that treatment with geniposide can attenuate postischemic LTP induction in a concentration-dependent manner. We infer that GluN2A-containing NMDARs are involved in the neuroprotection induced by geniposide treatment in ischemia.

Expression of Slit and Robo during remodeling of corticospinal tract in cervical spinal cord in middle cerebral artery occlusion rats.

BACKGROUND: Slits and Robos were associated with the generation of axons of corticospinal tract during the corticospinal tract (CST) remodeling after the cerebral ischemic stroke (CIS). However, little is known about the mechanism of CST remodeling. In this study, we detected the expression of Slits and Robos in middle cerebral artery occlusion (MCAO) rats to investigate the roles of Slits and Robos in the CIS. METHODS: MCAO model was established using modified Zea Longa method. Beam walking test (BWT) was conducted to evaluate the motor function. The images of the track of cortical spinal cord beam on day 7, 14 and 21 were observed by anterograde CST tracing. Biopinylated dextan amine (BDA) was used to mark CST anterogradely. Expression of GAP-43 mRNA and GAP-43 protein in cervical spinal cord was detected by Real-Time PCR and Western blot analysis, respectively. The expression of Slit1, Slit2 and Robo1 in cervical spinal cord was detected by immunofluorescence staining. RESULTS: The scores in the model group were significantly reduced compared to sham-operation group on day 7 (P < 0.001), 14 (P < 0.001) and 21 (P < 0.001), respectively. There was no significant difference in the score on day 7, 14 and 21 of the sham-operation groups (P > 0.05). In contrast, significant increase was noticed in the scores in model group, presenting a time-dependent manner. More CST staining fibers could be observed at the degenerative side in the model group compared with that of the sham-operation group on day 21. GAP-43 mRNA expression in the model group showed significant increase compared to that of sham-operation group on day 14 (P = 0.015) and 21 days (P = 0.002). The expression of GAP-43 protein in model group showed significant increase compared to that of sham-operation group on day 14 (P = 0.022) and day 21 (P = 0.008), respectively. The expression of Slit1 and Slit2 showed increase on day 14 and day 21, while the expression of Robo1 showed significant decrease in MCAO rats. CONCLUSION: Up-regulation of Slit1 and Slit2 and the downregulation of Robo1 may be related to the axons of CST midline crossing in spinal cord of MCAO rat during the spontaneous recovery of impaired motor function.

In situ slow-release recombinant growth differentiation factor 11 exhibits therapeutic efficacy in ischemic stroke.

Systemic growth differentiation factor 11 (GDF11) treatment improves the vasculature in the hippocampus and cortex in mice in recent studies. However, systemic application of recombinant GDF11 (rGDF11) cannot cross the brain blood barrier (BBB). Thus, large doses and long-term administration are required, while systemically applied high-dose rGDF11 is associated with deleterious effects, such as severe cachexia. This study tested whether in situ low dosage rGDF11 (1 µg/kg) protects the brain against ischemic stroke and it investigated the underlying mechanisms. Fibrin glue mixed with rGDF11 was applied to the surgical cortex for the slow release of rGDF11 in mice after permanent middle cerebral artery occlusion (MCAO). In situ rGDF11 improved cerebral infarction and sensorimotor function by upregulating Smad2/3 and downregulating FOXO3 expression. In situ rGDF11 was associated with reductions in protein and lipid oxidation, Wnt5a, iNOS and COX2 expression, at 24 h after injury. In situ rGDF11 protected hippocampal neurons and subventricular neural progenitor cells against MCAO injury, and increased newborn neurogenesis in the peri-infarct cortex. Systematic profiling and qPCR analysis revealed that Pax5, Sox3, Th, and Cdk5rap2, genes associated with neurogenesis, were increased by in situ rGDF11 treatment. In addition, greater numbers of newborn neurons in the peri-infarct cortex were observed with in situ rGDF11 than with systemic application. Our evidence indicates that in situ rGDF11 effectively decreases the extent of damage after ischemic stroke via antioxidative, anti-inflammatory and proneurogenic activities. We suggest that in situ slow-release rGDF11 with fibrin glue is a potential therapeutic approach against ischemic stroke.

Arbutin protects brain against middle cerebral artery occlusion-reperfusion (MCAo/R) injury.

Focal ischemia causes irreversible brain damage if cerebral blood flow is not restored promptly. Acute phase excitotoxicity and pro-oxidant and inflammatory events in the sub-chronic phase elicit coagulative necrosis, vascular injury, cerebral oedema, and neurobehavioral deficits. Earlier, in pre-clinical studies arbutin protected behavioral functions and improved therapeutic outcomes in different models of brain and metabolic disorders. Arbutin is natural hydroquinone that might protect against ischemia-reperfusion (I/R) injury. In this study, cerebro-protective effects of arbutin were evaluated in the middle cerebral artery occlusion-reperfusion (MCAo/R) mouse model. Mice were administered arbutin (50, 100 mg/kg, i.p.) for 21 days, and subjected to MCAo/R or sham surgery on day 14. Results showed brain infarction, blood-brain barrier dysfunction, oedema, and neurological deficits 24 h post-MCAo/R injury that were prevented by arbutin. Behavioral evaluations over the sub-chronic phase revealed MCAo/R triggered spatial and working memory deficits. Arbutin protected the memory against MCAo/R injury and decreased hydroxy-2'-deoxyguanosine, protein carbonyls, inflammatory cytokines (tumor necrosis factor-α, myeloperoxidase, matrix metalloproteinase-9, inducible nitric oxide synthase), and enhanced glutathione levels in the ischemia ipsilateral hemisphere. Arbutin decreased brain acetylcholinesterase activity, glutamate, and enhanced GABA levels against MCAo/R. Arbutin can alleviate I/R pathogenesis and protects neurobehavioral functions in the MCAo/R mouse model.

Circular RNA 0025984 Ameliorates Ischemic Stroke Injury and Protects Astrocytes Through miR-143-3p/TET1/ORP150 Pathway.

MiR-143-3p is aberrantly expressed in patients with ischemic stroke and associated with ischemic brain injury. However, the underlying mechanisms are largely unknown. Here, we confirmed circ_0025984 and TET1 as a sponge and target of miR-143-3p, respectively, by luciferase reporter assay. In astrocytes, OGD significantly decreased circ_0025984 and TET1 levels but increased miR-143-3p levels, which was also observed in brains of mice with MCAO. Treatment with miR-143-3p inhibitor or circ_0025984 significantly decreased astrocyte apoptosis and autophagy, as well as cerebral injury and neuron loss in mice with MCAO. Notably, TET1 overexpression decreased astrocyte apoptosis and autophagy and induced promoter hypomethylation and expression of ORP150. Our results demonstrated for the first time that circ_0025984 protects astrocytes from ischemia-induced autophagy and apoptosis by targeting the miR-143-3p/TET1 pathway and might inhibit cerebral injury induced by ischemic stroke. Furthermore, our data revealed the important positive regulation of ORP150 by TET1, which could be associated with its neuroprotective role. Graphical abstract Model for signaling pathway of circ_0025984/miR-143-3p/TET1 inastrocytes cultured under OGD. In astrocytes, circ_0025984 acts as a sponge of miR-143-3p, which directly targets TET1 and decreases its expression (A). After translocatinginto the nucleus, TET1 binds to the promoter of ORP150, converts 5mC into 5hmC,leading to DNA demethylation and increased expression of ORP150 (B). In astrocytescultured under OGD, ER stress is induced and eventually leads to apoptosis andautophagy mediated by ATG7, which is regulated by circ_0025984 via ORP150 andGRP78 (C).

25-Hydroxycholesterol protecting from cerebral ischemia-reperfusion injury through the inhibition of STING activity.

Middle cerebral artery occlusion (MCAO) injury refers to impaired blood supply to the brain that is caused by a cerebrovascular disease, resulting in local brain tissue ischemia, hypoxic necrosis, and rapid neurological impairment. Nevertheless, the mechanisms involved are unclear, and pharmacological interventions are lacking. 25-Hydroxycholesterol (25-HC) was reported to be involved in cholesterol and lipid metabolism as an oxysterol molecule. This study aimed to determine whether 25-HC exerts a cerebral protective effect on MCAO injury and investigate its potential mechanism. 25-HC was administered prior to reperfusion in a mouse model of MCAO injury. 25-HC evidently decreased infarct size induced by MCAO and enhanced brain function. It reduced stimulator of interferon gene (STING) activity and regulated mTOR to inhibit autophagy and induce cerebral ischemia tolerance. Thus, 25-HC improved MCAO injury through the STING channel. As indicated in this preliminary study, 25-HC improved MCAO injury by inhibiting STING activity and autophagy as well as by reducing brain nerve cell apoptosis. Thus, it is a potential treatment drug for brain injury.

Pediatric Case of Life-Threatening Stroke Caused by Reversible Cerebral Vasoconstriction Syndrome with Spontaneous Cervical Internal Carotid Artery Vasospasm: A Case Report.

Pediatric reversible cerebral vasoconstriction syndrome (RCVS) and spontaneous cervical internal carotid artery (ICA) vasospasm are rare conditions; the former is commonly associated with a favorable prognosis. A healthy 13-year-old girl presented with thunderclap headache, followed by left hemiparesis, during a curling match. Six days after onset, left hemiparesis worsened to hemiplegia. Magnetic resonance imaging showed progressive cerebral infarction caused by severe right middle cerebral artery and cervical ICA stenosis. She became comatose because of impending uncal herniation. Emergent surgical decompression was performed. Then, 59 days after onset, her multiple stenoses improved, which was consistent with RCVS concomitant with spontaneous cervical ICA vasospasm. This is the first case of RCVS that concurrently developed spontaneous cervical ICA vasospasm. The patient developed life-threatening stroke due to the hemodynamic impairment of the affected intracranial and cervical arteries. Spontaneous extracranial supra-aortic artery vasospasm can be a poor prognostic predictor of RCVS.

Recovery of an injured arcuate fasciculus via transcallosal fiber in a stroke patient: A case report.

RATIONALE: We report on a patient whose arcuate fasciculus (AF) and corticobulbar tract (CBT) recovered following an infarct in the middle cerebral artery (MCA) territory, demonstrated on serial diffusion tensor tractography (DTT). PATIENT CONCERNS: The patient showed moderate conduction aphasia on the Western Aphasia Battery with an aphasia quotient of 46.5‰ (spontaneous speech: 35.0‰, auditory comprehension: 36.0‰, and naming: 53.1‰) at 1 month after onset. His aphasia improved with an aphasia quotient of 49‰ (spontaneous speech: 71.0‰, auditory comprehension: 52.0‰, and naming: 59.0‰) at 10 months after onset. DIAGNOSIS: A 44-year-old right-handed male patient presented with aphasia and quadriplegia, which occurred at the onset of an infarct in the left MCA territory. INTERVENTION: Diffusion tensor imaging data were acquired twice (1 month and 10 months after onset). OUTCOMES: On one-month DTT, the discontinuation of the left AF and severe narrowing of the right CBT were observed. However, on ten-month DTT, the left AF was connected to the opposite AF by a new tract that passed through the splenium of corpus callosum, and the right CBT had become thicker. LESSONS: We believe that our results suggest a recovery mechanism of injured AF and CBT in stroke patients.

Long non­coding RNA XIST promotes cerebral ischemia/reperfusion injury by modulating miR­27a­3p/FOXO3 signaling.

Cerebral ischemia/reperfusion (I/R) injury leads to neuronal damage, which may cause disability and even mortality. Multiple studies have revealed that long non­coding RNAs (lncRNAs) serve pivotal roles in the pathogenesis of cerebral I/R injury. Therefore, the present study aimed to investigate whether the lncRNA X inactivate­specific transcript (XIST) protects neuronal cells from cerebral I/R injury. In the present study, reverse transcription­quantitative PCR demonstrated that XIST expression was upregulated in the brain tissues of an I/R mouse model and in oxygen and glucose deprivation/reperfusion (OGD/R)­treated Neuro­2a (N2a) cells. Knockdown of XIST alleviated cerebral injury, as well as reduced N2a cell apoptosis and reactive oxygen species (ROS) production. Additionally, luciferase reporter and RNA immunoprecipitation assays identified that XIST could bind with microRNA (miR)­27a­3p. It was found that miR­27a­3p expression was downregulated in the brain tissues of an I/R mouse model and in OGD/R­induced N2a cells. In addition, miR­27a­3p overexpression attenuated I/R­induced cerebral injury, and inhibited the apoptosis and ROS production of N2a cells. miR­27a­3p was found to target FOXO3. Silencing of FOXO3 alleviated cerebral injury, as well as inhibited N2a cell apoptosis and ROS production. Collectively, these findings indicated that XIST aggravated cerebral I/R injury by regulating miR­27a­3p/FOXO3 signaling, which may provide a novel insight into the treatment of cerebral I/R injury.

10-O-(N N-Dimethylaminoethyl)-Ginkgolide B Methane-Sulfonate (XQ-1H) Ameliorates Cerebral Ischemia Via Suppressing Neuronal Apoptosis.

OBJECTIVES: The 10-O-(N N-dimethylaminoethyl)-ginkgolide B methane-sulfonate (XQ-1H) is an effective novel drug for the treatment of ischemic cerebrovascular disease derived from Ginkgolide B, a traditional Chinese medicine, has been widely used in the treatment of cardiovascular and cerebrovascular diseases. However, whether XQ-1H exerts neuroprotective effect via regulating neuronal apoptosis and the underlying mechanism remain to be elucidated. MATERIALS AND METHODS: This study was aimed to investigate the neuroprotective effect of XQ-1H in rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) and the oxygen glucose deprivation/reoxygenation (OGD/R) induced neuronal apoptosis on pheochromocytoma (PC-12) cells. RESULTS: The results showed that administration of XQ-1H at different dosage (7.8, 15.6, 31.2 mg/kg) reduced the brain infarct and edema, attenuated the neuro-behavioral dysfunction, and improved cell morphology in brain tissue after MCAO/R in rats. Moreover, incubation with XQ-1H (1 µM, 3 µM, 10 µM, 50 µM, 100 µM) could increase the cell viability, and showed no toxic effect to PC-12 cells. XQ-1H at following 1 µM, 10 µM, 100 µM decreased the lactate dehydrogenase (LDH) activity and suppressed the cell apoptosis in PC-12 cells exposed to OGD/R. In addition, XQ-1H treatment could significantly inhibit caspase-3 activation both in vivo and in vitro, reciprocally modulate the expression of apoptosis related proteins, bcl-2, and bax via activating PI3K/Akt signaling pathway. For mechanism verification, LY294002, the inhibitor of PI3K/Akt pathway was introduced the expressions of bcl-2 and phosphorylated Akt were down-regulated, the expression of bax was up-regulated, indicating that XQ-1H could alleviate the cell apoptosis through activating the PI3K/Akt pathway. CONCLUSIONS: Our findings demonstrated that XQ-1H treatment could provide a neuroprotective effect against ischemic stroke induced by cerebral ischemia/reperfusion injury in vivo and in vitro through regulating neuronal survival and inhibiting apoptosis. The findings of the study confirmed that XQ-1H could be develop as a potential drug for treatment of cerebral ischemic stroke.