Exosomes-mediated delivery of miR-486-3p alleviates neuroinflammation via SIRT2-mediated inhibition of mitophagy after subarachnoid hemorrhage.

BACKGROUND: Neuroinflammation participates in the pathogenesis of subarachnoid haemorrhage (SAH); however, no effective treatments exist. MicroRNAs regulate several aspects of neuronal dysfunction. In a previous study, we found that exosomal miR-486-3p is involved in the pathophysiology of SAH. Targeted delivery of miR-486-3p without blood-brain barrier (BBB) restriction to alleviate SAH is a promising neuroinflammation approach. METHODS: In this study, we modified exosomes (Exo) to form an RVG-miR-486-3p-Exo (Exo/miR) to achieve targeted delivery of miR-486-3p to the brain. Neurological scores, brain water content, BBB damage, flow cytometry and FJC staining were used to determine the effect of miR-486-3p on SAH. Western blot analysis, ELISA and RT-qPCR were used to measure relevant protein and mRNA levels. Immunofluorescence staining and laser confocal detection were used to measure the expression of mitochondria, lysosomes and autophagosomes, and transmission electron microscopy was used to observe the level of mitophagy in the brain tissue of mice after SAH. RESULTS: Tail vein injection of Exo/miR improved targeting of miR-486-3p to the brains of SAH mice. The injection reduced levels of neuroinflammation-related factors by changing the phenotype switching of microglia, inhibiting the expression of sirtuin 2 (SIRT2) and enhancing mitophagy. miR-486-3p treatment alleviated neurobehavioral disorders, brain oedema, BBB damage and neurodegeneration. Further research found that the mechanism was achieved by regulating the acetylation level of peroxisome proliferator-activated receptor γ coactivator l alpha (PGC-1α) after SIRT2 enters the nucleus. CONCLUSION: Exo/miR treatment attenuates neuroinflammation after SAH by inhibiting SIRT2 expression and stimulating mitophagy, suggesting potential clinical applications.

Intimal Injury Potentially Plays a Key Role in the Formation of Carotid Artery Dissection: A Novel Animal Model Establishing.

Research on the pathophysiological mechanism of carotid artery dissection and its clinical translation is limited due to the lack of effective animal models to simulate the occurrence of this condition. Assuming that intimal injury is an important factor in the formation of carotid dissection, we established a novel method for inducing carotid dissection models by scraping the carotid intima using a fine needle. Scraping the carotid intima with fine needles can induce the rapid formation of carotid dissection. Magnetic resonance imaging and hematoxylin-eosin staining suggest the presence of false lumens and mural hematomas in the vessels. Our model-induction technique, inspired by iatrogenic catheter-induced artery dissections (carotid, coronary, aortic), significantly mimics the pathological process of clinical carotid dissection. The results suggest that mechanical injury may be a significant cause of carotid dissection and that intimal injury is a major factor in the formation of arterial dissections. This approach will provide assistance in the understanding of medically induced arterial dissection.

miR-93-5p impairs autophagy-lysosomal pathway via TET3 after subarachnoid hemorrhage.

Intact autophagy-lysosomal pathway (ALP) in neuronal survival is crucial. However, it remains unclear whether ALP is intact after subarachnoid hemorrhage (SAH). Ten-eleven translocation (TET) 3 primarily regulates genes related to autophagy in neurons in neurodegenerative diseases. This study aims to investigate the role of TET3 in the ALP following SAH. The results indicate that the ALP is impaired after SAH, with suppressed autophagic flux and an increase in autophagosomes. This is accompanied by a decrease in TET3 expression. Activation of TET3 by α-KG can improve ALP function and neural function to some extent. Silencing TET3 in neurons significantly inhibited the ALP function and increased apoptosis. Inhibition of miR-93-5p, which is elevated after SAH, promotes TET3 expression. This suggests that the downregulation of TET3 after SAH is, at least in part, due to elevated miR-93-5p. This study clarifies the key role of TET3 in the functional impairment of the ALP after SAH. The preliminary exploration revealed that miR-93-5p could lead to the downregulation of TET3, which could be a new target for neuroprotective therapy after SAH.

Potential of BMI as a screening indicator for extracranial-intracranial bypass surgery in patients with symptomatic artery occlusion: a post-hoc analysis of the CMOSS trial.

BACKGROUND: To investigate the association between BMI and the incidence of ischemic stroke in patients with symptomatic artery occlusion, and further to evaluate the utility of BMI as a screening tool for identifying candidates for extracranial-intracranial bypass surgery. MATERIALS AND METHODS: The authors analyzed the relationship between BMI and the occurrence of ipsilateral ischemic stroke (IIS) among patients receiving only medical management in the Carotid or Middle cerebral artery Occlusion Surgery Study (CMOSS). Additionally, the authors compared the primary endpoint of CMOSS-stroke or death within 30 days, or IIS after 30 days up to 2 years-among patients with varying BMIs who underwent either surgery or medical treatment. RESULTS: Of the 165 patients who treated medically only, 16 (9.7%) suffered an IIS within 2 years. BMI was independently associated with the incidence of IIS (hazard ratio: 1.16 per kg/m 2 ; 95% CI: 1.06-1.27). The optimal BMI cutoff for predicting IIS was 24.5 kg/m 2 . Patients with BMI ≥24.5 kg/m 2 experienced a higher incidence of IIS compared to those with BMI <24.5 kg/m 2 (17.4 vs. 0.0%, P <0.01). The incidence of the CMOSS primary endpoint was significantly different between the surgical and medical groups for patients with BMI ≥24.5 kg/m 2 (5.3 vs. 19.8%, P <0.01) and those with BMI <24.5 kg/m 2 (10.6 vs. 1.4%; P =0.02). Surgical intervention was independently associated with a reduced rate of the CMOSS primary endpoint in patients with BMI ≥24.5 kg/m 2 . CONCLUSION: Data from the CMOSS trial indicate that patients with BMI ≥24.5 kg/m 2 are at a higher risk of IIS when treated medically only and appear to derive greater benefit from bypass surgery compared to those with lower BMIs. Given the small sample size and the inherent limitations of retrospective analyses, further large-scale, prospective studies are necessary to confirm these findings.

Qualifying Event and Recurrence of Ischemic Stroke in Symptomatic Artery Occlusion: A Post Hoc Analysis of CMOSS.

BACKGROUND: The authors aimed to elucidate the relationship between latest ischemic event and the incidence of subsequent ischemic stroke in patients with symptomatic artery occlusion. METHODS AND RESULTS: We analyzed the association between qualifying event-the latest ischemic event (transient ischemic attack [TIA] or stroke)-and the incidence of ipsilateral ischemic stroke in patients with symptomatic artery occlusion treated with medical therapy alone in CMOSS (Carotid or Middle Cerebral Artery Occlusion Surgery Study). The incidence of CMOSS primary outcomes, including any stroke or death within 30 days after randomization or ipsilateral ischemic stroke between 30 days and 2 years, between the bypass surgical and medical groups, stratified by qualifying events, was also compared. Of the 165 patients treated with medical therapy alone, 75 had a TIA and 90 had a stroke as their qualifying event. The incidence of ipsilateral ischemic stroke did not significantly differ between patients with a TIA and those with a stroke as their qualifying event (13.3% versus 6.7%, P=0.17). In multivariate analysis, the qualifying event was not associated with the incidence of ipsilateral ischemic stroke. There were no significant differences in the CMOSS primary outcomes between the surgical and medical groups, regardless of the qualifying event being TIA (10.1% versus 12.2%, P=0.86) or stroke (6.7% versus 8.9%, P=0.55). CONCLUSIONS: Among patients with symptomatic artery occlusion and hemodynamic insufficiency, the risk of subsequent ipsilateral ischemic stroke does not appear to be lower in patients presenting with a TIA compared with those with a stroke. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01758614.

Gender potentially affects early postoperative hyponatremia in pituitary adenoma: XGBoost-based predictive modeling.

Purpose: The occurrence of hyponatremia is a prevalent complication following transnasal transsphenoidal surgery for pituitary adenoma surgery, which adversely affects patient prognosis, hospitalization duration, and rehospitalization risk. The primary objective of this study is to strengthen the correlation between clinical factors associated with pituitary adenoma and postoperative hyponatremia. Additionally, the study aims to develop a predictive model for postoperative hyponatremia in patients with pituitary adenoma, with the ultimate goal of establishing a basis for reducing the occurrence of postoperative hyponatremia following surgical interventions. Methods: The chi-square test or Fisher test was employed for nominal data, while the t-test or Mann-Whitney test was utilized for continuous data analysis. In cases where the data exhibited statistical differences, binary logistic analysis was conducted to examine the risk and protective factors associated with postoperative hyponatremia. XGBoost was employed to construct predictive models for hyponatremia in this study. The patients were partitioned into training and test sets, and the most suitable parameters were determined through five-fold cross-validation and subsequently utilized for training on the training set. The discriminatory capability was assessed on the internal validation set. Results and conclusions: Out of the total 280 patients included in this investigation, 82 patients experienced early postoperative hyponatremia. Among these individuals, male gender (P = 0.02, odds ratio = 1.98) was identified as a risk factor for early postoperative hyponatremia, while preoperative chloride levels (P = 0.021, odds ratio = 0.866) and surgery time (P = 0.039, odds ratio = 0.990) were identified as protective factors against postoperative hyponatremia. The XGBoost model exhibited a sensitivity of 94.2%, a specificity of 61.5%, a positive predictive value of 51.6%, a negative predictive value of 96%, and identified male gender, preoperative sodium, and preoperative cortisol as the most significant predictors. Our findings indicate that gender may have influence in the development of early postoperative hyponatremia in patients with pituitary adenomas.

Neuron-targeted liposomal coenzyme Q10 attenuates neuronal ferroptosis after subarachnoid hemorrhage by activating the ferroptosis suppressor protein 1/coenzyme Q10 system.

Subarachnoid hemorrhage (SAH) is primarily attributed to the rupture of intracranial aneurysms and is associated with a high incidence of disability and mortality. SAH disrupts the blood‒brain barrier, leading to the release of iron ions from blood within the subarachnoid space, subsequently inducing neuronal ferroptosis. A recently discovered protein, known as ferroptosis suppressor protein 1 (FSP1), exerts anti-ferroptotic effects by facilitating the conversion of oxidative coenzyme Q 10 (CoQ10) to its reduced form, which effectively scavenges reactive oxygen radicals and mitigates iron-induced ferroptosis. In our investigation, we observed an increase in FSP1 levels following SAH. However, the depletion of CoQ10 caused by SAH hindered the biological function of FSP1. Therefore, we created neuron-targeted liposomal CoQ10 by introducing the neuron-targeting peptide Tet1 onto the surface of liposomal CoQ10. Our objective was to determine whether this formulation could activate the FSP1 system and subsequently inhibit neuronal ferroptosis. Our findings revealed that neuron-targeted liposomal CoQ10 effectively localized to neurons at the lesion site after SAH. Furthermore, it facilitated the upregulation of FSP1, reduced the accumulation of malondialdehyde and reactive oxygen species, inhibited neuronal ferroptosis, and exerted neuroprotective effects both in vitro and in vivo. Our study provides evidence that supplementation with CoQ10 can effectively activate the FSP1 system. Additionally, we developed a neuron-targeted liposomal CoQ10 formulation that can be selectively delivered to neurons at the site of SAH. This innovative approach represents a promising therapeutic strategy for neuronal ferroptosis following SAH. STATEMENT OF SIGNIFICANCE: Subarachnoid hemorrhage (SAH) is primarily attributed to the rupture of intracranial aneurysms and is associated with a high incidence of disability and mortality. Ferroptosis suppressor protein 1 (FSP1), exerts anti-ferroptotic effects by facilitating the conversion of oxidative coenzyme Q 10 (CoQ10) to its reduced form, which effectively scavenges reactive oxygen radicals and mitigates iron-induced ferroptosis. In our investigation, we observed an increase in FSP1 levels following SAH. However, the depletion of CoQ10 caused by SAH hindered the biological function of FSP1. Therefore, we created neuron-targeted liposomal CoQ10. We find that it effectively localized to neurons at the lesion site after SAH and activated the FSP1/CoQ10 system. This innovative approach represents a promising therapeutic strategy for neuronal ferroptosis following SAH and other central nervous system diseases characterized by disruption of the blood-brain barrier.

Hydrogen exerts neuroprotective effects after subarachnoid hemorrhage by attenuating neuronal ferroptosis and inhibiting neuroinflammation.

OBJECTIVE: Spontaneous subarachnoid hemorrhage (SAH), the third most common stroke subtype, is associated with high mortality and disability rates. Therefore, finding effective therapies to improve neurological function after SAH is critical. The objective of this study was to investigate the potential neuroprotective effects of hydrogen in the context of SAH, specifically, by examining its role in attenuating neuronal ferroptosis and inhibiting neuroinflammation, which are exacerbated by excess iron ions after SAH. METHODS: Mice were exposed to chambers containing 3% hydrogen, and cells were cultured in incubators containing 60% hydrogen. Neurological function in mice was assessed using behavioral scores. Protein changes were detected using western blotting. Inflammatory factors were detected using enzyme linked immunosorbent assay. Probes, electron microscopy, and related kits were employed to detect oxidative stress and ferroptosis. RESULTS: Hydrogen improved the motor function, sensory function, and cognitive ability of mice after SAH. Additionally, hydrogen facilitated Nuclear factor erythroid 2 -related factor 2 activation, upregulated Glutathione peroxidase 4, and inhibited Toll-like receptor 4, resulting in downregulation of inflammatory responses, attenuation of oxidative stress after SAH, and inhibition of neuronal ferroptosis. CONCLUSION: Hydrogen exerts neuroprotective effects by inhibiting neuronal ferroptosis and attenuating neuroinflammation after SAH.

Novel perfluorocarbon-based oxygenation therapy alleviates Post-SAH hypoxic brain injury by inhibiting HIF-1α.

In comparison to other stroke types, subarachnoid hemorrhage (SAH) is characterized by an early age of onset and often results in poor prognosis. The inadequate blood flow at the site of the lesion leads to localized oxygen deprivation, increased level of hypoxia-inducible factor-1α (HIF-1α), and triggers inflammatory responses and oxidative stress, ultimately causing hypoxic brain damage. Despite the potential benefits of oxygen (O2) administration, there is currently a lack of efficient focal site O2 delivery following SAH. Conventional clinical O2 supply methods, such as transnasal oxygenation and hyperbaric oxygen therapy, do not show the ideal therapeutic effect in severe SAH patients. The perfluorocarbon oxygen carrier (PFOC) demonstrates efficacy in transporting O2 and responding to elevated levels of CO2 at the lesion site. Through cellular experiments, we determined that PFOC oxygenation serves as an effective therapeutic approach in inhibiting hypoxia. Furthermore, our animal experiments showed that PFOC oxygenation outperforms O2 breathing, leading to microglia phenotypic switching and the suppression of inflammatory response via the inhibition of HIF-1α. Therefore, as a new type of O2 therapy after SAH, PFOC oxygenation can effectively reduce hypoxic brain injury and improve neurological function.

Menaquinone-4 attenuates ferroptosis by upregulating DHODH through activation of SIRT1 after subarachnoid hemorrhage.

BACKGROUND: Menaquinone-4(MK-4), the isoform of vitamin K2 in the brain, exerts neuroprotective effects against a variety of central nervous system disorders. This study aimed to demonstrate the anti-ferroptosis effects of MK-4 in neurons after SAH. METHODS: A subarachnoid hemorrhage (SAH) model was prepared by endovascular perforation in mice. In vitro hemoglobin stimulation of primary cortical neurons mimicked SAH. MK-4, Brequinar (BQR, DHODH inhibitor), and Selisistat (SEL, SIRT1 inhibitor) were administered, respectively. Subsequently, WB, immunofluorescence was used to determine protein expression and localization, and transmission electron microscopy was used to observe neuronal mitochondrial structure while other indicators of ferroptosis were measured. RESULTS: MK-4 treatment significantly upregulated the protein levels of DHODH; decreased GSH, PTGS2, NOX1, ROS, and restored mitochondrial membrane potential. Meanwhile, MK-4 upregulated the expression of SIRT1 and promoted its entry into the nucleus. BQR or SEL partially abolished the protective effect of MK-4 on, neurologic function, and ferroptosis. CONCLUSIONS: Taken together, our results suggest that MK-4 attenuates ferroptosis after SAH by upregulating DHODH through the activation of SIRT1.

Systemic Immune-Inflammation Index Predicts the Prognosis of Traumatic Brain Injury.

OBJECTIVE: Systemic inflammation following traumatic brain injury (TBI) has been extensively studied over the past decades, as it contributes significantly to the pathophysiological injury mechanisms and subsequent poor outcomes. Systemic immune-inflammation (SII) index is a novel biomarker of systemic inflammatory response. However, its predictive value regarding TBI prognosis in clinical practice remains insufficiently investigated. METHODS: A total of 102 TBI patients admitted to Nanjing Drum Tower Hospital from July 2019 to February 2022 were enrolled. We employed various statistical analyses to evaluate the correlation between inflammatory indicators upon admission and patient prognosis, compared the predictive accuracy of these indicators, and generated receiver operating curve analysis to test their prognostic performance. RESULTS: The SII index, platelet count, absolute lymphocyte count, and neutrophil/lymphocyte ratio (NLR) were capable of distinguishing TBI prognosis according to univariate logistic regression models (P < 0.05). Multivariate logistic regression models revealed that increased SII index, platelet count, and NLR upon admission were independent predictors of poor TBI prognosis (P < 0.05). Receiver operating curve analysis further demonstrated that the SII index (area under the curve = 0.845, 95% confidence interval 0.769-0.921, P = 0.000) exhibited higher predictive ability than the NLR (area under the curve = 0.694, 95% confidence interval 0.591-0.796, P = 0.001). CONCLUSIONS: Our findings suggested that increased SII index during the early stages of TBI was an independent risk factor for poor prognosis with satisfactory predictive value. The SII index provides a reliable, convenient, and cost-effective prognostic model to evaluate systemic inflammation after TBI and identify patients at risk of poor outcomes, thereby offering valuable guidance for clinical practice.

Extracranial-Intracranial Bypass and Risk of Stroke and Death in Patients With Symptomatic Artery Occlusion: The CMOSS Randomized Clinical Trial.

Importance: Prior trials of extracranial-intracranial (EC-IC) bypass surgery showed no benefit for stroke prevention in patients with atherosclerotic occlusion of the internal carotid artery (ICA) or middle cerebral artery (MCA), but there have been subsequent improvements in surgical techniques and patient selection. Objective: To evaluate EC-IC bypass surgery in symptomatic patients with atherosclerotic occlusion of the ICA or MCA, using refined patient and operator selection. Design, Setting, and Participants: This was a randomized, open-label, outcome assessor-blinded trial conducted at 13 centers in China. A total of 324 patients with ICA or MCA occlusion with transient ischemic attack or nondisabling ischemic stroke attributed to hemodynamic insufficiency based on computed tomography perfusion imaging were recruited between June 2013 and March 2018 (final follow-up: March 18, 2020). Interventions: EC-IC bypass surgery plus medical therapy (surgical group; n = 161) or medical therapy alone (medical group; n = 163). Medical therapy included antiplatelet therapy and stroke risk factor control. Main Outcomes and Measures: The primary outcome was a composite of stroke or death within 30 days or ipsilateral ischemic stroke beyond 30 days through 2 years after randomization. There were 9 secondary outcomes, including any stroke or death within 2 years and fatal stroke within 2 years. Results: Among 330 patients who were enrolled, 324 patients were confirmed eligible (median age, 52.7 years; 257 men [79.3%]) and 309 (95.4%) completed the trial. For the surgical group vs medical group, no significant difference was found for the composite primary outcome (8.6% [13/151] vs 12.3% [19/155]; incidence difference, -3.6% [95% CI, -10.1% to 2.9%]; hazard ratio [HR], 0.71 [95% CI, 0.33-1.54]; P = .39). The 30-day risk of stroke or death was 6.2% (10/161) in the surgical group and 1.8% (3/163) in the medical group, and the risk of ipsilateral ischemic stroke beyond 30 days through 2 years was 2.0% (3/151) and 10.3% (16/155), respectively. Of the 9 prespecified secondary end points, none showed a significant difference including any stroke or death within 2 years (9.9% [15/152] vs 15.3% [24/157]; incidence difference, -5.4% [95% CI, -12.5% to 1.7%]; HR, 0.69 [95% CI, 0.34-1.39]; P = .30) and fatal stroke within 2 years (2.0% [3/150] vs 0% [0/153]; incidence difference, 1.9% [95% CI, -0.2% to 4.0%]; P = .08). Conclusions and Relevance: Among patients with symptomatic ICA or MCA occlusion and hemodynamic insufficiency, the addition of bypass surgery to medical therapy did not significantly change the risk of the composite outcome of stroke or death within 30 days or ipsilateral ischemic stroke beyond 30 days through 2 years. Trial Registration: ClinicalTrials.gov Identifier: NCT01758614.