p97 inhibits integrated stress response-induced neuronal apoptosis after subarachnoid hemorrhage in mice by enhancing proteasome function.

Neuronal apoptosis is a common pathological change in early brain injury after subarachnoid hemorrhage (SAH), and it is closely associated with neurological deficits. According to previous research, p97 exhibits a remarkable anti-cardiomyocyte apoptosis effect. p97 is a critical molecule in the growth and development of the nervous system. However, it remains unknown whether p97 can exert an anti-neuronal apoptosis effect in SAH. In the present study, we examined the role of p97 in neuronal apoptosis induced after SAH and investigated the underlying mechanism. We established an in vivo SAH mice model and overexpressed the p97 protein through transfection of the mouse cerebral cortex. We analyzed the protective effect of p97 on neurons and evaluated short-term and long-term neurobehavior in mice after SAH. p97 was found to be significantly downregulated in the cerebral cortex of the affected side in mice after SAH. The site showing reduced p97 expression also exhibited a high level of neuronal apoptosis. Adeno-associated virus-mediated overexpression of p97 significantly reduced the extent of neuronal apoptosis, improved early and long-term neurological function, and repaired the neuronal damage in the long term. These neuroprotective effects were accompanied by enhanced proteasome function and inhibition of the integrated stress response (ISR) apoptotic pathway involving eIF2α/CHOP. The administration of the p97 inhibitor NMS-873 induced a contradictory effect. Subsequently, we observed that inhibiting the function of the proteasome with the proteasome inhibitor PS-341 blocked the anti-neuronal apoptosis effect of p97 and enhanced the activation of the ISR apoptotic pathway. However, the detrimental effects of NMS-873 and PS-341 in mice with SAH were mitigated by the administration of the ISR inhibitor ISRIB. These results suggest that p97 can promote neuronal survival and improve neurological function in mice after SAH. The anti-neuronal apoptosis effect of p97 is achieved by enhancing proteasome function and inhibiting the overactivation of the ISR apoptotic pathway.

miR-96-5p alleviates cerebral ischemia-reperfusion injury in mice by inhibiting pyroptosis via downregulating caspase 1.

Ischemic stroke is one of the leading causes of global mortality and disability. Nevertheless, successful treatment remains limited. In this study, we investigated the efficacy and the mechanism of miR-96-5p in protecting acute ischemic brain injury in adult mice. Focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) in adult male C57BL/6 mice. MiR-96-5p or the negative control was administered via intracerebroventricular injection. The expression of pyroptosis-related genes and activation of various resident cells in the brain was assessed by RT-qPCR, western blot, immunohistochemistry, and immunofluorescence. Modified neurological severity score, rotarod test, cylinder test, brain water content, and cerebral infarction volume were used to evaluate the behavioral deficits and the severity of brain injury after MCAO. Flow cytometry, TUNEL staining, and Nissl staining were employed to assess the neuron damage. MiR-96-5p decreased markedly in the ischemic stroke model in vivo and in vitro. MiR-96-5p mimics suppressed the expression of caspase 1 and alleviated the apoptosis rate in OGD/R treatment N2a cells, however, the miR-96-5p inhibitor caused the opposite results. Intracerebroventricular delivery of miR-96-5p agomir significantly mitigated behavioral deficits, brain water content, and cerebral infarction volume after MCAO. In addition, treatment with miR-96-5p agomir downregulated the expression of caspase 1/cleaved caspase 1 and Gsdmd/Gsdmd-N, while alleviating the neuron damage. In summary, overexpression of miR-96-5p suppresses pyroptosis and reduces brain damage in the acute phase of ischemic stroke, providing new insight into the treatment of acute ischemic stroke.

Nrf-2 modulates excitability of hippocampal neurons by regulating ferroptosis and neuroinflammation after subarachnoid hemorrhage in rats.

Excitability of hippocampal neurons in subarachnoid hemorrhage (SAH) rats has not been well studied. The rat SAH model was applied in this study to explore the role of nuclear factor E2-related factor (Nrf-2) in the early brain injury of SAH. The neural excitability of CA1 pyramidal cells (PCs) in SAH rats was evaluated by using electrophysiology experiments. Ferroptosis and neuroinflammation were measured by ELISA, transmission electron microscopy and western blotting. Our results indicated that SAH induced neurological deficits, brain edema, ferroptosis, neuroinflammation and neural excitability in rats. Ferrostatin-1 treatment significantly decreased the expression and distribution of IL-1ß, IL-6, IL-10, TGF-ß and TNF-α. Inhibiting ferroptosis by ferrostatin-1 can attenuate neural excitability, neurological deficits, brain edema and neuroinflammation in SAH rats. Inhibiting the expression of Nrf-2 significantly increased the neural excitability and the levels of IL-1ß, IL-6, IL-10, TGF-ß and TNF-α in Fer-1-treated SAH rats. Taken together, inhibiting the Nrf-2 induces early brain injury, brain edema and the inflammatory response with increasing of neural excitability in Fer-1-treated SAH rats. These results have indicated that inhibiting ferroptosis, neuroinflammation and neural excitability attenuates early brain injury after SAH by regulating the Nrf-2.

VEGF combined with DAPT promotes tissue regeneration and remodeling in vascular grafts.

Previous research on tissue-engineered blood vessels (TEBVs) has mainly focused on the intima or adventitia unilaterally, neglecting the equal importance of both layers. Meanwhile, the efficacy of grafts modified with vascular endothelial growth factor (VEGF) merely has been limited. Here, we developed a small-diameter graft that can gradually release VEGF and γ secretase inhibitor IX (DAPT) to enhance tissue regeneration and remodeling in both the intima and adventitia. In vitro, experiments revealed that the combination of VEGF and DAPT had superior pro-proliferation and pro-migration effects on endothelial cells. In vivo, the sustained release of VEGF and DAPT from the grafts resulted in improved regeneration and remodeling. Specifically, in the intima, faster endothelialization and regeneration of smooth muscle cells led to higher patency rates and better remodeling. In the adventitia, a higher density of neovascularization, M2 macrophages and fibroblasts promoted cellular ingrowth and replacement of the implant with autologous neo-tissue. Furthermore, western blot analysis confirmed that the regenerated ECs were functional and the effect of DAPT was associated with increased expression of vascular endothelial growth factor receptor 2. Our study demonstrated that the sustained release of VEGF and DAPT from the graft can effectively promote tissue regeneration and remodeling in both the intima and adventitia. This development has the potential to significantly accelerate the clinical application of small-diameter TEBVs.

A Mendelian randomisation, propensity score matching study to investigate causal association between serum homocysteine and intracranial aneurysm.

BACKGROUND AND PURPOSE: Recent observational studies have reported that serum total homocysteine (tHcy) is associated with intracranial aneurysms (IAs). However, the causal effect of tHcy on IAs is unknown. We leveraged large-scale genetic association and real-world data to investigate the causal effect of tHcy on IA formation. METHODS: We performed a two-sample Mendelian randomisation (MR) using publicly available genome-wide association studies summary statistics to investigate the causal relationship between tHcy and IAs, following the recommendations of the Strengthening the Reporting of Observational Studies in Epidemiology-MR statement. Furthermore, a propensity score matching (PSM) analysis was conducted to evaluate the detailed effects of tHcy on risk of IA formation by utilizing real-world multicentre data, including 9902 patients with and without IAs (1:1 matched). Further interaction and subgroup analyses were performed to elucidate how tHcy affects risk of IA formation. RESULTS: MR analyses indicated that genetically determined tHcy was causally associated with IA risk (OR, 1.38, 95% CI 1.07 to 1.79; p=0.018). This is consistent with the more conservative weighted median analysis (OR, 1.41, 95% CI 1.03 to 1.93; p=0.039). Further sensitivity analyses showed no evidence of horizontal pleiotropy or heterogeneity of single nucleotide polymorphisms in causal inference. According to the PSM study, we found that, compared with low tHcy (≤15 µmol/L), moderate tHcy (>15-30 µmol/L) (OR 2.13, 95% CI 1.93 to 2.36) and high tHcy (>30 µmol/L) (OR 3.66, 95% CI 2.71 to 4.95) were associated with a higher IA risk (p trend <0.001). Subgroup analyses demonstrated significant ORs of tHcy in each subgroup when stratified by traditional cardiovascular risk factors. Furthermore, there was also a synergistic effect of tHcy and hypertension on IA risk (p interaction <0.001; the relative excess risk due to interaction=1.65, 95% CI 1.29 to 2.01). CONCLUSION: Both large-scale genetic evidence and multicentre real-world data support a causal association between tHcy and risk of IA formation. Serum tHcy may serve as a biomarker to identify high-risk individuals who would particularly benefit from folate supplementation.

Cellular energy supply for promoting vascular remodeling of small-diameter vascular grafts: a preliminary study of a new strategy for vascular graft development.

Rapid endothelialization is extremely essential for the success of small-diameter tissue-engineered vascular graft (TEVG) (<6 mm) transplantation. However, severe inflammation in situ often causes cellular energy decline of endothelial cells. The cellular energy supply involved in vascular graft therapy remains unclear, and whether promoting energy supply would be helpful in the regeneration of vascular grafts needs to be established. In our work, we generated an AMPK activator (5-aminoimidazole-4-carboxamide ribonucleotide, AICAR) immobilized vascular graft. AICAR-modified vascular grafts were successfully generated by the co-electrospinning technique. In vitro results indicated that AICAR could upregulate energy supply in endothelial cells and reprogram macrophages (MΦ) to assume an anti-inflammatory phenotype. Furthermore, endothelial cells (ECs) co-cultured with AICAR achieved higher survival rates, better migration, and angiogenic capacity than the controls. Concurrently, a rabbit carotid artery transplantation model was used to investigate AICAR-modified vascular grafts at different time points. The results showed that AICAR-modified vascular grafts had higher patency rates (92.9% and 85.7% at 6 and 12 weeks, respectively) than those of the untreated group (11.1% and 0%). In conclusion, AICAR strengthened the cellular energy state and attenuated the adverse effects of inflammation. AICAR-modified vascular grafts achieved better vascular remodeling. This study provides a new perspective on promoting the regeneration of small-diameter vascular grafts.

Dexmedetomidine Inhibits Gasdermin D-Induced Pyroptosis via the PI3K/AKT/GSK3ß Pathway to Attenuate Neuroinflammation in Early Brain Injury After Subarachnoid Hemorrhage in Rats.

Subarachnoid hemorrhage (SAH) is one kind of life-threatening stroke, which leads to severe brain damage. Pyroptosis plays a critical role in early brain injury (EBI) after SAH. Previous reports suggest that SAH-induced brain edema, cell apoptosis, and neuronal injury could be suppressed by dexmedetomidine (Dex). In this study, we used a rat model of SAH to investigate the effect of Dex on pyroptosis in EBI after SAH and to determine the mechanisms involved. Pyroptosis was found in microglia in EBI after SAH. Dex significantly alleviated microglia pyroptosis via reducing pyroptosis executioner GSDMD and inhibited the release of proinflammatory cytokines induced by SAH. Furthermore, the reduction of GSDMD by Dex was abolished by the PI3K inhibitor LY294002. In conclusion, our data demonstrated that Dex reduces microglia pyroptosis in EBI after SAH via the activation of the PI3K/AKT/GSK3ß pathway.

Metformin Inhibits NLR Family Pyrin Domain Containing 3 (NLRP)-Relevant Neuroinflammation via an Adenosine-5'-Monophosphate-Activated Protein Kinase (AMPK)-Dependent Pathway to Alleviate Early Brain Injury After Subarachnoid Hemorrhage in Mice.

Neuroinflammation plays a key role in the pathogenesis of early brain injury (EBI) after subarachnoid hemorrhage (SAH). Previous studies have shown that metformin exerts anti-inflammatory effects and promotes functional recovery in various central nervous system diseases. We designed this study to investigate the effects of metformin on EBI after SAH. Our results indicate that the use of metformin alleviates the brain edema, behavioral disorders, cell apoptosis, and neuronal injury caused by SAH. The SAH-induced NLRP3-associated inflammatory response and the activation of microglia are also suppressed by metformin. However, we found that the blockade of AMPK with compound C weakened the neuroprotective effects of metformin on EBI. Collectively, our findings indicate that metformin exerts its neuroprotective effects by inhibiting neuroinflammation in an AMPK-dependent manner, by modulating the production of NLRP3-associated proinflammatory factors and the activation of microglia.

Elucidating the Synergistic Effect of Multiple Chinese Herbal Prescriptions in the Treatment of Post-stroke Neurological Damage.

Background: Traditional Chinese medicine (TCM) has been widely used in the treatment of human diseases. However, the synergistic effects of multiple TCM prescriptions in the treatment of stroke have not been thoroughly studied. Objective of the study: This study aimed to reveal the mechanisms underlying the synergistic effects of these TCM prescriptions in stroke treatment and identify the active compounds. Methods: Herbs and compounds in the Di-Tan Decoction (DTD), Xue-Fu Zhu-Yu Decoction (XFZYD), and Xiao-Xu-Ming Decoction (XXMD) were acquired from the TCMSP database. SEA, HitPick, and TargetNet web servers were used for target prediction. The compound-target (C-T) networks of three prescriptions were constructed and then filtered using the collaborative filtering algorithm. We combined KEGG enrichment analysis, molecular docking, and network analysis approaches to identify active compounds, followed by verification of these compounds with an oxygen-glucose deprivation and reoxygenation (OGD/R) model. Results: The filtered DTD network contained 39 compounds and 534 targets, the filtered XFZYD network contained 40 compounds and 508 targets, and the filtered XXMD network contained 55 compounds and 599 targets. The filtered C-T networks retained approximately 80% of the biological functions of the original networks. Based on the enriched pathways, molecular docking, and network analysis results, we constructed a complex network containing 3 prescriptions, 14 botanical drugs, 26 compounds, 13 targets, and 5 pathways. By calculating the synergy score, we identified the top 5 candidate compounds. The experimental results showed that quercetin, baicalin, and ginsenoside Rg1 independently and synergistically increased cell viability. Conclusion: By integrating pharmacological and chemoinformatic approaches, our study provides a new method for identifying the effective synergistic compounds of TCM prescriptions. The filtered compounds and their synergistic effects on stroke require further research.

Optimal treatment strategy for adult patients with newly diagnosed glioblastoma: a systematic review and network meta-analysis.

To compare the efficacy and safety of treatments based on the Stupp protocol for adult patients with newly diagnosed glioblastoma and to determine the optimal treatment option for patients with different O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation statuses. We estimated hazard ratios (HRs) for overall survival (OS) and odds ratios (ORs) for adverse events of grade 3 or higher (AEs ≥ 3). Twenty-one randomized controlled trials involving 6478 patients treated with 21 different treatment strategies were included. Results of the pooled HRs indicated tumor-treating fields (TTF) combined with the Stupp protocol resulted in the most favorable OS for patients with and without MGMT promoter methylation. Subgroup analyses by the two MGMT promoter statuses indicated that lomustine-temozolomide plus radiotherapy or TTF combination therapy was associated with the best OS for patients with methylated MGMT promoter (HR, 1.03; 95% credible interval [CI], 0.54-1.97), and standard cilengitide combination therapy or TTF combination treatment was associated with the best OS for patients with unmethylated MGMT promoter (HR, 1.05; 95% CI, 0.67-1.64). Regarding AEs ≥ 3, there were no significant differences in pooled ORs. However, Bayesian ranking profiles that demonstrated intensive cilengitide combination therapy and TTF combination therapy have a similar possibility to cause the least toxicity. These results indicated that TTF combination therapy was associated with increased survival, irrespective of the MGMT promoter methylation status, and a relatively tolerated safety profile compared with other combination treatments. The optimal treatment option for glioblastoma patients with different MGMT promoter methylation statuses was different.

Tim-3 deteriorates neuroinflammatory and neurocyte apoptosis after subarachnoid hemorrhage through the Nrf2/HMGB1 signaling pathway in rats.

Inflammation is known to play an important role in early brain injury (EBI) after subarachnoid hemorrhage (SAH). T cell immunoglobulin and mucin domain-3 (Tim-3) has emerged as a critical regulator of adaptive and innate immune responses, and has been identified to play a vital role in certain inflammatory diseases; The present study explored the effect of Tim-3 on inflammatory responses and detailed mechanism in EBI following SAH. We investigated the effects of Tim-3 on SAH models established by endovascular puncture method in Sprague-Dawley rats. The present studies revealed that SAH induced a significant inflammatory response and significantly increased Tim-3 expression. Tim-3-AAV administration aggravated neurocyte apoptosis, brain edema, blood-brain barrier permeability, and neurological dysfunction; significantly inhibited Nrf2 expression; and increased HMGB1 expression and secretion of pro-inflammatory cytokines, such as tumor necrosis factor alpha, interleukin (IL)-1 beta, IL-17, and IL-18. However, Tim-3 siRNA or NK252 administration abolished the pro-inflammatory effects of Tim-3. Our results indicate a function for Tim-3 as a molecular player that links neuroinflammation and brain damage after SAH. We reveal that Tim-3 overexpression deteriorates neuroinflammatory and neurocyte apoptosis after subarachnoid hemorrhage through the Nrf2/HMGB1 signaling pathway in rats.

TSG-6 Attenuates Oxidative Stress-Induced Early Brain Injury in Subarachnoid Hemorrhage Partly by the HO-1 and Nox2 Pathways.

BACKGROUND: Early brain injury (EBI) refers to acute brain injury during the first 72 h after subarachnoid hemorrhage (SAH), which is one of the major causes of poor prognosis after SAH. Here, we investigated the effect and the related mechanism of TSG-6 on EBI after SAH. MATERIALS AND METHODS: The Sprague-Dawley rat model of SAH was developed by the endovascular perforation method. TSG-6 (5µg) was administered by an intraventricular injection within 1.5 h after SAH. The effects of TSG-6 on EBI were assessed by neurological score, brain water content (BWC) and TUNEL staining. Immunofluorescence staining was used to assay NF-κB/p-NF-κB expression in microglia. Protein expression levels of heme oxygenase-1 (HO-1), NADPH oxidase 2 (Nox2), Bcl-2, Bax, and cleaved-caspase-3 were measured to investigate the potential mechanism. The enzyme activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and the level of reactive oxygen species (ROS) were analyzed using commercially available kits. RESULTS: The results showed that TSG-6 treatment alleviated the neurobehavioral dysfunction and reduced BWC and the number of TUNEL-positive neurons in EBI after SAH. TSG-6 decreased the ROS level and enhanced the enzyme activity of SOD and GSH-Px after SAH. Furthermore TSG-6 inhibited the NF-κB activation, increased the protein expression levels of HO-1 and Bcl-2 and decreased the expression levels of Nox2, Bax, and cleaved-caspase-3. The administration of TSG-6 siRNA abolished the protective effects of TSG-6 on EBI after SAH. CONCLUSION: We found that TSG-6 attenuated oxidative stress and apoptosis in EBI after SAH partly by inhibiting NF-κB and activating HO-1 pathway in brain tissue.

Resolvin D1 ameliorates Inflammation-Mediated Blood-Brain Barrier Disruption After Subarachnoid Hemorrhage in rats by Modulating A20 and NLRP3 Inflammasome.

Inflammation is typically related to dysfunction of the blood-brain barrier (BBB) that leads to early brain injury (EBI) after subarachnoid hemorrhage (SAH). Resolvin D1 (RVD1), a lipid mediator derived from docosahexaenoic acid, possesses anti-inflammatory and neuroprotective properties. This study investigated the effects and mechanisms of RVD1 in SAH. A Sprague-Dawley rat model of SAH was established through endovascular perforation. RVD1was injected through the femoral vein at 1 and 12 h after SAH induction. To further explore the potential neuroprotective mechanism, a formyl peptide receptor two antagonist (WRW4) was intracerebroventricularly administered 1 h after SAH induction. The expression of endogenous RVD1 was decreased whereas A20 and NLRP3 levels were increased after SAH. An exogenous RVD1 administration increased RVD1 concentration in brain tissue, and improved neurological function, neuroinflammation, BBB disruption, and brain edema. RVD1 treatment upregulated the expression of A20, occludin, claudin-5, and zona occludens-1, as well as downregulated nuclear factor-κBp65, NLRP3, matrix metallopeptidase 9, and intercellular cell adhesion molecule-1 expression. Furthermore, RVD1 inhibited microglial activation and neutrophil infiltration and promoted neutrophil apoptosis. However, the neuroprotective effects of RVD1 were abolished by WRW4. In summary, our findings reveal that RVD1 provides beneficial effects against inflammation-triggered BBB dysfunction after SAH by modulating A20 and NLRP3 inflammasome.

Silencing of SNHG12 Enhanced the Effectiveness of MSCs in Alleviating Ischemia/Reperfusion Injuries via the PI3K/AKT/mTOR Signaling Pathway.

Previous studies have reported that the long non-coding RNA SNHG12 (lncRNA SNHG12) plays a critical role in regulating the function of mesenchymal stem cells (MSCs); however, the effect of lncRNA SNHG12 on MSCs in injured brain tissue has rarely been reported. We studied the effect and mechanism of lncRNA SNHG12-modified mesenchymal stem cells (MSCs) in treating brain injuries caused by ischemia/reperfusion (I/R). I/R treated rat brain microvascular endothelial cells (BMECs) were co-cultured with MSCs or I/R pretreated MSCs. Next, BMEC proliferation was detected by using CCK-8 and EdU assays, and cell apoptosis was determined by using flow cytometry and the Hoechst staining method. Autophagy of BMECs was determined using immunofluorescence and expression of associated pathway proteins were measured by western blotting. Moreover, BMEC proliferation, apoptosis, and autophagy were also determined after the BMECs had been co-cultured with shSNHG12-MSCs. In addition, a rat model of middle cerebral artery occlusion (MCAO) was used to further confirm the findings obtained with cells. I/R treatment significantly decreased the proliferation of BMECs, but increased their levels of SNHG12 expression, apoptosis, and autophagy. However, co-culturing of BMECs with MSCs markedly alleviated the reduction in BMEC proliferation and the increases in BMEC apoptosis and autophagy, as well as the phosphorylation of PI3K, AKT, and mTOR proteins in BMECs that had been induced by I/R. Furthermore, shSNHG12 remarkably enhanced the effects of MSCs. In addition, an injection MSCs reduced the infarct areas and rates of cell apoptosis in MACO rats, and reduced the phosphorylation of PI3K, AKT, and mTOR proteins. Moreover, shSNHG12 enhanced the ameliorative effect of MSCs in treating brain injuries in the MACO rats. In conclusion, silencing of SNHG12 enhanced the effects of MSCs in reducing apoptosis and autophagy of BMECs by activating the PI3K/AKT/mTOR signaling pathway.

Mesenchymal stem cells alleviate the early brain injury of subarachnoid hemorrhage partly by suppression of Notch1-dependent neuroinflammation: involvement of Botch.

BACKGROUND: Activated microglia-mediated neuroinflammation has been regarded as an underlying key player in the pathogenesis of subarachnoid hemorrhage (SAH)-induced early brain injury (EBI). The therapeutic potential of bone marrow mesenchymal stem cells (BMSCs) transplantation has been demonstrated in several brain injury models and is thought to involve modulation of the inflammatory response. The present study investigated the salutary effects of BMSCs on EBI after SAH and the potential mechanism mediated by Notch1 signaling pathway inhibition. METHODS: The Sprague-Dawley rats SAH model was induced by endovascular perforation method. BMSCs (3 × 106 cells) were transplanted intravenously into rats, and N-[N-(3,5-difluorophenacetyl-L-alanyl)]-S-phenylglycine t-butyl ester (DAPT), a Notch1 activation inhibitor, and Notch1 small interfering RNA (siRNA) were injected intracerebroventricularly. The effects of BMSCs on EBI were assayed by neurological score, brain water content (BWC), blood-brain barrier (BBB) permeability, magnetic resonance imaging, hematoxylin and eosin staining, and Fluoro-Jade C staining. Immunofluorescence and immunohistochemistry staining, Western blotting, and quantitative real-time polymerase chain reaction were used to analyze various proteins and transcript levels. Pro-inflammatory cytokines were measured by enzyme-linked immunosorbent assay. RESULTS: BMSCs treatment mitigated the neurobehavioral dysfunction, BWC and BBB disruption associated with EBI after SAH, reduced ionized calcium binding adapter molecule 1 and cluster of differentiation 68 staining and interleukin (IL)-1 beta, IL-6 and tumor necrosis factor alpha expression in the left hemisphere but concurrently increased IL-10 expression. DAPT or Notch1 siRNA administration reduced Notch1 signaling pathway activation following SAH, ameliorated neurobehavioral impairments, and BBB disruption; increased BWC and neuronal degeneration; and inhibited activation of microglia and production of pro-inflammatory factors. The augmentation of Notch1 signal pathway agents and phosphorylation of nuclear factor-κB after SAH were suppressed by BMSCs but the levels of Botch were upregulated in the ipsilateral hemisphere. Botch knockdown in BMSCs abrogated the protective effects of BMSCs treatment on EBI and the suppressive effects of BMSCs on Notch1 expression. CONCLUSIONS: BMSCs treatment alleviated neurobehavioral impairments and the inflammatory response in EBI after SAH; these effects may be attributed to Botch upregulation in brain tissue, which subsequently inhibited the Notch1 signaling pathway.

The role of wall shear stress in the parent artery as an independent variable in the formation status of anterior communicating artery aneurysms.

OBJECTIVES: The study aimed to determine which hemodynamic parameters independently characterize anterior communicating artery (AcomA) aneurysm formation and explore the threshold of wall shear stress (WSS) of the parent artery to better illustrate the correlation between the magnitude of WSS and AcomA aneurysm formation. METHODS: Eighty-one patients with AcomA aneurysms and 118 patients without intracranial aneurysms (control population), as confirmed by digital subtraction angiography (DSA) from January 2014 to May 2017, were included in this cross-sectional study. Three-dimensional-DSA was performed to evaluate the morphologic characteristics of AcomA aneurysms. Local hemodynamic parameters were obtained using transcranial color-coded duplex (TCCD). Multivariate logistic regression and a two-piecewise linear regression model were used to determine which hemodynamic parameters are independent predictors of AcomA aneurysm formation and identify the threshold effect of WSS of the parent artery with respect to AcomA aneurysm formation. RESULTS: Univariate analyses showed that the WSS (p < 0.0001), angle between the A1 and A2 segments of the anterior cerebral artery (ACA) (p < 0.001), hypertension (grade II) (p = 0.007), fasting blood glucose (FBG; > 6.0 mmol/L) (p = 0.005), and dominant A1 (p < 0.001) were the significant parameters. Multivariate analyses showed a significant association between WSS of the parent artery and AcomA aneurysm formation (p = 0.0001). WSS of the parent artery (7.8-12.3 dyne/cm2) had a significant association between WSS and aneurysm formation (HR 2.0, 95% CI 1.3-2.8, p < 0.001). CONCLUSIONS: WSS ranging between 7.8 and 12.3 dyne/cm2 independently characterizes AcomA aneurysm formation. With each additional unit of WSS, there was a one-fold increase in the risk of AcomA aneurysm formation. KEY POINTS: • Multivariate analyses and a two-piecewise linear regression model were used to evaluate the risk factors for AcomA aneurysm formation and the threshold effect of WSS on AcomA aneurysm formation. • WSS ranging between 7.8 and 12.3 dyne/cm 2 was shown to be a reliable hemodynamic parameter in the formation of AcomA aneurysms. The probability of AcomA aneurysm formation increased one-fold for each additional unit of WSS. • An ultrasound-based TCCD technique is a simple and accessible noninvasive method for detecting WSS in vivo; thus, it can be applied as a screening tool for evaluating the probability of aneurysm formation in primary care facilities and community hospitals because of the relatively low resource intensity.

High wall shear stress beyond a certain range in the parent artery could predict the risk of anterior communicating artery aneurysm rupture at follow-up.

OBJECTIVE: Among clinical and morphological criteria, hemodynamics is the main predictor of aneurysm growth and rupture. This study aimed to identify which hemodynamic parameter in the parent artery could independently predict the rupture of anterior communicating artery (ACoA) aneurysms by using multivariate logistic regression and two-piecewise linear regression models. An additional objective was to look for a more simplified and convenient alternative to the widely used computational fluid dynamics (CFD) techniques to detect wall shear stress (WSS) as a screening tool for predicting the risk of aneurysm rupture during the follow-up of patients who did not undergo embolization or surgery. METHODS: One hundred sixty-two patients harboring ACoA aneurysms (130 ruptured and 32 unruptured) confirmed by 3D digital subtraction angiography at three centers were selected for this study. Morphological and hemodynamic parameters were evaluated for significance with respect to aneurysm rupture. Local hemodynamic parameters were obtained by MR angiography and transcranial color-coded duplex sonography to calculate WSS magnitude. Multivariate logistic regression and a two-piecewise linear regression analysis were performed to identify which hemodynamic parameter independently characterizes the rupture status of ACoA aneurysms. RESULTS: Univariate analysis showed that WSS (p < 0.001), circumferential wall tension (p = 0.005), age (p < 0.001), the angle between the A1 and A2 segments of the anterior cerebral artery (p < 0.001), size ratio (p = 0.023), aneurysm angle (p < 0.001), irregular shape (p = 0.005), and hypertension (grade II) (p = 0.006) were significant parameters. Multivariate analyses showed significant association between WSS in the parent artery and ACoA aneurysm rupture (p = 0.0001). WSS magnitude, evaluated by a two-piecewise linear regression model, was significantly correlated with the rupture of the ACoA aneurysm when the magnitude was higher than 12.3 dyne/cm2 (HR 7.2, 95% CI 1.5-33.6, p = 0.013). CONCLUSIONS: WSS in the parent artery may be one of the reliable hemodynamic parameters characterizing the rupture status of ACoA aneurysms when the WSS magnitude is higher than 12.3 dyne/cm2. Analysis showed that with each additional unit of WSS (even with a 1-unit increase of WSS), there was a 6.2-fold increase in the risk of rupture for ACoA aneurysms.

TSG-6 attenuates inflammation-induced brain injury via modulation of microglial polarization in SAH rats through the SOCS3/STAT3 pathway.

BACKGROUND: An acute and drastic inflammatory response characterized by the production of inflammatory mediators is followed by stroke, including SAH. Overactivation of microglia parallels an excessive inflammatory response and worsened brain damage. Previous studies indicate that TSG-6 has potent immunomodulatory and anti-inflammatory properties. This study aimed to evaluate the effects of TSG-6 in modulating immune reaction and microglial phenotype shift after experimental SAH. METHODS: The SAH model was established by endovascular puncture method for Sprague-Dawley rats (weighing 280-320 g). Recombinant human protein and specific siRNAs for TSG-6 were exploited in vivo. Brain injury was assessed by neurologic scores, brain water content, and Fluoro-Jade C (FJC) staining. Microglia phenotypic status was evaluated and determined by Western immunoblotting, quantitative real-time polymerase chain reaction (qPCR) analyses, flow cytometry, and immunofluorescence labeling. RESULTS: SAH induced significant inflammation, and M1-dominated microglia polarization increased expression of TSG-6 and neurological dysfunction in rats. rh-TSG-6 significantly ameliorated brain injury, decreased proinflammatory mediators, and skewed microglia towards a more anti-inflammatory property 24-h after SAH. While knockdown of TSG-6 further induced detrimental effects of microglia accompanied with more neurological deficits, the anti-inflammation effects of rh-TSG-6 were associated with microglia phenotypic shift by regulating the level of SOCS3/STAT3 axis. CONCLUSIONS: TSG-6 exerted neuroprotection against SAH-induced EBI in rats, mediated in part by skewing the balance of microglial response towards a protective phenotype, thereby preventing excessive tissue damage and improving functional outcomes. Our findings revealed the role of TSG-6 in modulating microglial response partially involved in the SOCS3/STAT3 pathway and TSG-6 may be a promising therapeutic target for the treatment of brain injury following SAH.

China Intracranial Aneurysm Project (CIAP): protocol for a prospective cohort study of interventional treatment and craniotomy for unruptured aneurysms.

INTRODUCTION: There are two approaches for the treatment of intracranial aneurysm (IA): interventional therapy and craniotomy, both of which have their advantages and disadvantages in terms of treatment efficacy. To avoid overtreatment of unruptured aneurysms (UIA), to save valuable medical resources and to reduce patient mortality and disability rate, it is vital that neurosurgeons select the most appropriate type of treatment to provide the best levels of care. In this study, we propose a refined, prospective, multicentre study for the Chinese population with strictly defined patient inclusion criteria, along with the selection of representative clinical participating centres. METHODS AND ANALYSIS: This report describes a multicentre, prospective cohort study. As IA is extremely harmful if it ruptures, ethical issues need to be taken into account with regard to this study. Researchers are therefore not able to use randomised controlled trials. The study will be conducted by 12 clinical centres located in different regions of China. The trial recruitment programme begins in 2016 and is scheduled to be completed in 2020. We expect 1500 participants with UIA to be included. Clinical information relating to the participants will be recorded objectively. The primary endpoints are an evaluation of the safety and efficiency of interventional treatment and craniotomy for 6 months after surgery, with each participant completing at least 1 year of follow-up. The secondary endpoint is the evaluation of safety and efficacy of interventional therapy and craniotomy clipping when participants are treated for 12 months. We also address the success of treatment and the incidence of adverse events. ETHICS AND DISSEMINATION: The research protocol and the informed consent form for participants in this study were approved by the Ethics Committee of Zhujiang Hospital of Southern Medical University (2017-SJWK-001). The results of this study are expected to be disseminated in peer-reviewed journals in 2021. TRIAL REGISTRATION NUMBER: NCT03133598.

Cerebral Microbleeds Could Be Independently Associated with Intracranial Aneurysm Rupture: A Cross-Sectional Population-Based Study.

OBJECTIVE: To determine whether the presence of cerebral microbleeds (CMBs) is independently associated with intracranial aneurysm rupture and to identify the time interval of CMB-related intracranial aneurysm rupture. METHODS: This cross-sectional study included 1847 patients with unruptured and ruptured intracranial aneurysms from January 2010 to November 2017. Clinical records and imaging, including T2-weighted gradient-recalled echo sequence magnetic resonance imaging that identified the presence of CMBs preoperatively, were evaluated. Univariate analysis and multivariate logistic regression were done to determine which parameters were independent factors for aneurysm rupture. The time interval of CMB-related intracranial aneurysm rupture was also evaluated. RESULTS: CMBs confirmed by magnetic resonance imaging were present in 142 patients (142/1847; 7.7%). Of 142 patients with CMBs, 56 patients (including 17 ruptured aneurysms) who received endovascular treatment and another 86 consecutive patients who did not receive embolization or surgery for various reasons were followed for 3-49 months. The incidence of CMB-related intracranial aneurysm rupture was 27.9% (24/86) during the follow-up period. The time interval of CMB-related intracranial aneurysm rupture was 3-27 months (median 9.5 months). Multivariate analyses showed CMBs were significantly correlated with intracranial aneurysm rupture (odds ratio = 1.6; 95% confidence interval, 1.1-2.4; P = 0.010). CONCLUSIONS: CMBs were independently associated with intracranial aneurysm rupture. Patients with CMBs have a 60% increased risk of aneurysm rupture compared with patients without CMBs.