Targeting Microglial Metabolic Rewiring Synergizes with Immune-Checkpoint Blockade Therapy for Glioblastoma.

Glioblastoma (GBM) constitutes the most lethal primary brain tumor for which immunotherapy has provided limited benefit. The unique brain immune landscape is reflected in a complex tumor immune microenvironment (TIME) in GBM. Here, single-cell sequencing of the GBM TIME revealed that microglia were under severe oxidative stress, which induced nuclear receptor subfamily 4 group A member 2 (NR4A2)-dependent transcriptional activity in microglia. Heterozygous Nr4a2 (Nr4a2+/-) or CX3CR1+ myeloid cell-specific Nr4a2 (Nr4a2fl/flCx3cr1Cre) genetic targeting reshaped microglia plasticity in vivo by reducing alternatively activated microglia and enhancing antigen presentation capacity for CD8+ T cells in GBM. In microglia, NR4A2 activated squalene monooxygenase (SQLE) to dysregulate cholesterol homeostasis. Pharmacologic NR4A2 inhibition attenuated the protumorigenic TIME, and targeting the NR4A2 or SQLE enhanced the therapeutic efficacy of immune-checkpoint blockade in vivo. Collectively, oxidative stress promotes tumor growth through NR4A2-SQLE activity in microglia, informing novel immune therapy paradigms in brain cancer. SIGNIFICANCE: Metabolic reprogramming of microglia in GBM informs synergistic vulnerabilities for immune-checkpoint blockade therapy in this immunologically cold brain tumor. This article is highlighted in the In This Issue feature, p. 799.

Clinically relevant orthotopic xenograft models of patient-derived glioblastoma in zebrafish.

An accurate prediction of the intracranial infiltration tendency and drug response of individual glioblastoma (GBM) cells is essential for personalized prognosis and treatment for this disease. However, the clinical utility of mouse patient-derived orthotopic xenograft (PDOX) models remains limited given current technical constraints, including difficulty in generating sufficient sample numbers from small tissue samples and a long latency period for results. To overcome these issues, we established zebrafish GBM xenografts of diverse origin, which can tolerate intracranial engraftment and maintain their unique histological features. Subsequent single-cell RNA-sequencing (scRNA-seq) analysis confirmed significant transcriptional identity to that of invading GBM microtumors observed in the proportionally larger brains of model animals and humans. Endothelial scRNA-seq confirmed that the zebrafish blood-brain barrier is homologous to the mammalian blood-brain barrier. Finally, we established a rapid and efficient zebrafish PDOX (zPDOX) model, which can predict long-term outcomes of GBM patients within 20 days. The zPDOX model provides a novel avenue for precision medicine of GBM, especially for the evaluation of intracranial infiltration tendency and prediction of individual drug sensitivity.

Phenotypic plasticity of myeloid cells in glioblastoma development, progression, and therapeutics.

Glioblastoma (GBM) is the most common and malignant type of intracranial tumors with poor prognosis. Accumulating evidence suggests that phenotypic alterations of infiltrating myeloid cells in the tumor microenvironment are important for GBM progression. Conventional tumor immunotherapy commonly targets T-cells, while innate immunity as a therapeutic target is an emerging field. Targeting infiltrating myeloid cells that induce immune suppression in the TME provides a novel direction to improve the prognosis of patients with GBM. The factors released by tumor cells recruit myeloid cells into tumor bed and reprogram infiltrating myeloid cells into immunostimulatory/immunosuppressive phenotypes. Reciprocally, infiltrating myeloid cells, especially microglia/macrophages, regulate GBM progression and affect therapeutic efficacy. Herein, we revisited biological characteristics and functions of infiltrating myeloid cells and discussed the recent advances in immunotherapies targeting infiltrating myeloid cells in GBM. With an evolving understanding of the complex interactions between infiltrating myeloid cells and tumor cells in the tumor microenvironment, we will expand novel immunotherapeutic regimens targeting infiltrating myeloid cells in GBM treatment and improve the outcomes of GBM patients.

Endothelial Autophagy: an Effective Target for Radiation-induced Cerebral Capillary Damage.

Toxicity to central nervous system tissues is the common side effects for radiotherapy of brain tumor. The radiation toxicity has been thought to be related to the damage of cerebral endothelium. However, because of lacking a suitable high-resolution vivo model, cellular response of cerebral capillaries to radiation remained unclear. Here, we present the flk:eGFP transgenic zebrafish larvae as a feasible model to study the radiation toxicity to cerebral capillary. We showed that, in living zebrafish larvae, radiation could induce acute cerebral capillary shrinkage and blood-flow obstruction, resulting brain hypoxia and glycolysis retardant. Although in vivo neuron damage was also observed after the radiation exposure, further investigation found that they didn't response to the same dosage of radiation in vitro, indicating that radiation induced neuron damage was a secondary-effect of cerebral vascular function damage. In addition, transgenic labeling and qPCR results showed that the radiation-induced acute cerebral endothelial damage was correlated with intensive endothelial autophagy. Different autophagy inhibitors could significantly alleviate the radiation-induced cerebral capillary damage and prolong the survival of zebrafish larvae. Therefore, we showed that radiation could directly damage cerebral capillary, resulting to blood flow deficiency and neuron death, which suggested endothelial autophagy as a potential target for radiation-induced brain toxicity.

The prognostic values of neutrophil to lymphocyte ratio for outcomes in chronic obstructive pulmonary disease.

OBJECTIVE: Neutrophil to lymphocyte ratio (NLR) is considered as an inflammatory biomarker for clinical outcomes in patients with chronic obstructive pulmonary disease (COPD). We aimed to conduct a meta-analysis to evaluate the prognostic values of NLR for the exacerbation and mortality in patients with COPD. METHODS: We searched the database of Cochrane Central Register of Controlled Trials, EMBASE, and PubMed, before September 2017. The eligible studies were retrieved by 2 authors independently following the criteria. The pooled odds ratios (ORs) of included studies were used to evaluate the prognostic values of NLR. Subgroup analyses were conducted to make the results more accurate. RESULTS: Nine studies with 5140 patients were enrolled in this analysis. The high NLR was associated with higher risk of exacerbation (OR: 3.81, 95% confidence interval [CI]: 1.20-12.13, P = .02) and mortality (OR: 2.60, 95% CI: 1.48-4.57, P < .01). By subgroup analysis, high NLR could predict the mortality in patients >70 years (OR: 2.16, 95% CI: 1.17-3.98, P = .01) but not in patients <70 years (OR: 4.08, 95% CI: 0.91-18.24, P = .07), and had a higher predictive ability in Asian group (OR: 3.64, 95% CI: 1.87-7.08, P < .01) than Eurasia group (OR: 1.82, 95% CI: 1.43-2.32, P < .01). In addition, high NLR could predict the short-term mortality (OR: 2.70, 95% CI: 1.10-6.63, P = .03) and the long-term mortality (OR: 2.61, 95% CI: 1.20-5.65, P = .02). CONCLUSIONS: The NLR may be an independent predictor for incidence of exacerbation in patients with COPD. In addition, high NLR may be associated with higher mortality in patients with COPD, especially for Asian and the patients with higher mean NLR.

Extravasation of contrast (Spot Sign) predicts in-hospital mortality in ruptured arteriovenous malformation.

BACKGROUND AND PURPOSE: The spot sign is a highly specific and sensitive predictor of hematoma expansion in following primary intracerebral hemorrhage (ICH). Rare cases of the spot sign have been documented in patients with intracranial hemorrhage secondary to arteriovenous malformation (AVM). The purpose of this retrospective study is to assess the accuracy of spot sign in predicting clinical outcomes in patients with ruptured AVM. MATERIALS AND METHODS: A retrospective analysis of a prospectively maintained database was performed for patients who presented to West China Hospital with ICH secondary to AVM in the period between January 2009 and September 2016. Two radiologists blinded to the clinical data independently assessed the imaging data, including the presence of spot sign. Statistical analysis using univariate testing, multivariate logistic regression testing, and receiver operating characteristic curve (AUC) analysis was performed. RESULTS: A total of 116 patients were included. Overall, 18.9% (22/116) of subjects had at least 1 spot sign detected by CT angiography, 7% (8/116) died in hospital, and 27% (31/116) of the patients had a poor outcome after 90 days. The spot sign had a sensitivity of 62.5% and specificity of 84.3% for predicting in-hospital mortality (p = .02, AUC 0.734). No correlation detected between the spot sign and 90-day outcomes under multiple logistic regression (p = .19). CONCLUSIONS: The spot sign is an independent predictor for in-hospital mortality. The presence of spot sign did not correlate with the 90 day outcomes in this patient cohort. The results of this report suggest that patients with ruptured AVM with demonstrated the spot sign on imaging must receive aggressive treatment early on due to the high risk of mortality.

The Association Between the Neutrophil-to-Lymphocyte Ratio and Mortality in Patients With Acute Respiratory Distress Syndrome: A Retrospective Cohort Study.

PURPOSE: Systemic inflammation relates to the initiation and progression of acute respiratory distress syndrome (ARDS). As neutrophil-to-lymphocyte ratio (NLR) has been shown to be a prognostic inflammatory biomarker in various diseases, in this study, we sought to explore whether NLR is a prognostic factor in patients with ARDS. METHODS: A retrospective study was performed on patients diagnosed as ARDS admitted to the intensive care unit (ICU). We calculated the NLR by dividing the neutrophil count by the lymphocyte count and categorized patients into four groups based on quartile of NLR values. The association of NLR quartiles and 28-day mortality was assessed using multivariable Cox regression. Secondary outcomes included ICU mortality and hospital mortality. RESULTS: A total of 224 patients were included in the final analysis. The median (interquartile range) NLRs from first quartile to fourth quartile were as follows: 6.88 (4.61-7.94), 13.06 (11.35-14.89), 20.99 (19.09-23.19), and 39.39 (32.63-50.15), respectively. The 28-day mortalities for the same groups were as follows: 10.7%, 19.6%, 41.4%, and 53.6% (P < 0.001). Cox regression analysis showed NLR was a significant risk factor predicting 28-day mortality (first quartile, reference group; second quartile, adjusted hazard ratio [HR]= 1.674, 95% confidence interval [CI], 0.462-6.063, P = 0.432; third quartile, HR = 5.075, 95% CI, 1.554-16.576, P = 0.007; fourth quartile, HR = 5.815, 95% CI, 1.824-18.533, P = 0.003). Similar trends were observed for ICU mortality and hospital mortality. CONCLUSIONS: High NLR was associated with the poor outcome in critically ill patients with ARDS. The NLR therefore seems to be a prognostic biomarker of outcomes in critically ill patients with ARDS. Further investigation is required to validate this relationship with data collected prospectively.

The factors associated with hemorrhagic presentation in children with untreated brain arteriovenous malformation: a meta-analysis.

OBJECTIVE Rupture of arteriovenous malformations (AVMs) would result in high mortality and prevalence of disability in pediatric patients. Decisions regarding the treatment of AVMs need to weigh the risk of rupture over the course of their natural history against the possibility of creating a lesion during treatment. Multiple factors have been proposed to predict hemorrhagic presentation of pediatric patients with AVMs. The aim of this meta-analysis was to evaluate the predictors of hemorrhagic presentation in pediatric patients with AVMs. METHODS The authors searched the PubMed and EMBASE databases. Studies reporting the predictors of hemorrhagic presentation in children with untreated brain AVMs were included. The predictive ability of identified predictors was assessed by odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS A higher risk of hemorrhagic presentation was found in AVMs with smaller size (< 3 cm, OR 2.97, 95% CI 1.94­4.54, p < 0.00001), deep venous drainage (OR 2.28, 95% CI 1.55­3.36, p < 0.0001), a single draining vein (OR 2.23, 95% CI 1.27­3.92, p = 0.005), a single feeder (OR 3.72, 95% CI 1.31­10.62, p = 0.01), a deep location (OR 1.82, 95% CI 1.22­2.72, p = 0.004), an infratentorial location (OR 2.25, 95% CI 1.19­4.26, p = 0.01), and diffuse morphology (OR 8.94, 95% CI 3.01­26.55, p < 0.0001). In addition, the AVMs with draining vein ectasia (OR 0.35, 95% CI 0.13­0.97, p = 0.04) and high Spetzler-Martin (SM) grade (OR 0.53, 95% CI 0.36­0.78, p = 0.001) had a lower risk of hemorrhagic presentation in pediatric patients. CONCLUSIONS Smaller AVMs, deep venous drainage, a single draining vein, a single feeder, deep/infratentorial location, diffuse morphology, and high SM grade were identified as positive predictors for hemorrhagic presentation. Particularly, patients with diffuse AVMs have a higher risk of hemorrhagic presentation than other factors and may need active treatments. However, factors such as age, sex, draining vein stenosis, and associated aneurysms were not associated with hemorrhagic presentation. ABBREVIATIONS AVM = arteriovenous malformation; CI = confidence interval; NOS = Newcastle-Ottawa Scale; OR = odds ratio; SM = Spetzler-Martin.

The Effect of Cerebrovascular Stenosis on -Peri-Hematoma Cerebral Perfusion and Clinical Outcomes in Patients with Supratentorial Spontaneous Intracerebral Hemorrhage.

BACKGROUND Many factors are associated with the cerebral hypoperfusion after spontaneous intracerebral hemorrhage (sICH), however, the effect of cerebrovascular stenosis on peri-hematoma cerebral blood flow (CBF) and 90-day poor outcomes in patients with spontaneous intracerebral hemorrhage is still unclear. MATERIAL AND METHODS From September 2016 to March 2017, we prospectively collected data on adults with supratentorial spontaneous intracerebral hemorrhages. Using the Propensity Score model, we compared the peri-hematoma CBF and 90-day poor outcomes (mRS ≥3) in the stenosis group and the control group. RESULTS Before matching, a total of 116 patients were included in this study, 25 patients in the stenosis group and 91 patients in the control group. After matching, the patients in the stenosis group had a higher absolute decrease of CBF (p=0.003), higher relative decrease of CBF (p=0.016), and higher incidence of 90-day poor outcomes (p=0.041) than the control group. With subgroup analysis, the patients with Glasgow Coma Scale from 13 to 15 (p=0.035), hematoma in the cerebral lobe (p=0.003), mean arterial pressure lower than 120 mm Hg (p=0.003), absolute decrease of CBF higher than 15 mL/100 g per minute (p=0.007), and relative decrease of CBF higher than 30% (p=0.020) had poorer outcomes. CONCLUSIONS In our series, the stenosis of main cerebral vessels decreased the peri-hematoma CBF and increased the rate of 90-day poor outcomes. Despite higher Glasgow Coma Scale, the evaluation of cerebral perfusion in patients with sICH is needed, especially for the patients with hematoma in the cerebral lobe and lower mean arterial pressure; and treatments to keep adequate cerebral perfusion are needed.

Intracerebral hemorrhage in an adult patient with Tetralogy of Fallot: Case report and review of the literature.

RATIONALE: Tetralogy of Fallot (TOF) accounts for approximately 5% of all congenital heart disease. However, only 1% of patients with TOF survive to the age of 40 years without undergoing surgery. Additionally, the relationship between intracerebral hemorrhage and unrepaired TOF remains unknown. We report a rare case of unrepaired TOF in a patient who presented with intracerebral hemorrhage, and we also present a literature review. PATIENT CONCERNS: A 40-year-old man presented with headache and right-sided limb weakness. DIAGNOSES: He was diagnosed with TOF approximately a year prior to presentation and did not undergo any definitive treatment or any symptomatic management. Head computed tomography revealed an intracerebral hematoma in the left basal ganglia. The patient was drowsy, and his blood oxygen saturation was 77%. INTERVENTIONS: Owing to his poor cardiopulmonary status, the patient did not undergo surgery and was treated with only symptomatic supportive therapy. OUTCOMES: After 2 days of therapy, his disturbance of consciousness and motor ability showed improvement. LESSONS: Literature reviews reveal that intracerebral hemorrhage is rarely observed in patients with TOF, and to date, only 3 cases have been reported. Furthermore, this patient was 40 years old and did not undergo cardiac surgery. Severe hypoxia, as well as low levels of platelets and coagulation factors in the blood could have led to intracerebral hemorrhage.

Macrophages as Nanocarriers for Drug Delivery: Novel Therapeutics for Central Nervous System Diseases.

Many central nervous system (CNS) diseases were thought to be untreatable due to the presence of the blood-brain barrier (BBB). The chemokine gradients secreted from CNS parenchyma can induce macrophage migration to the brain, induce firm adherence to the endothelium of BBB, and eventually to enter the brain parenchyma. Macrophages migrating into CNS can promote neuron regeneration, induce inflammation and angiogenesis. These properties can potentially allow macrophages to act as carriers for drug/nano formulations across the BBB, and reach the potential target sites. Many nanomaterials cannot be used for the management of CNS diseases because of their low carrying efficiency. Macrophage which transports nanomaterials to pathological sites is rendered as an attractive tool for the transportation of drugs to previously inaccessible regions within the brain parenchyma. Nanomaterials engulfed by macrophages can be released at target sites, and be used for therapeutic or diagnostic purposes. In this review, we focus on macrophages as the cell-carrier to deliver nano-drugs into CNS, describe the biological behavior of macrophages during pathological conditions and discuss the application of cell drug delivery system in recent years.

Clinical features and prognostic factors in patients with intraventricular hemorrhage caused by ruptured arteriovenous malformations.

Intraventricular hemorrhage (IVH) was associated with poor outcomes in patients with intracerebral hemorrhage. IVH had a high incidence in patients with ruptured arteriovenous malformations (AVMs). In this study, we aimed to discuss the clinical features and prognostic factors of outcomes in the patients with AVM-related IVH.From January 2010 to January 2016, we collected the data of the patients with AVM-related IVH retrospectively. The data, including clinical and radiological parameters, were collected to evaluate the clinical features. Univariate and multivariate logistic regression analyses were used to identify the prognostic factors for clinical outcomes (hydrocephalus, 6-month outcomes measured by the modified Rankin scale) in our cohort.A total of 67 eligible patients were included and 19 patients (28%) only presented with IVH. Thirty-three patients (49%) presented hydrocephalus, and 12 patients (18%) presented brain ischemia. Nineteen patients (28%) had a poor outcome after 6 months. In multivariate logistic regression, subarachnoid hemorrhage (SAH) (P = .028) was associated with hydrocephalus and higher Graeb score (P = .080) tended to increase the risk of hydrocephalus. The high Glasgow coma scale (P = .010), large hematoma volume of parenchyma (P = .006), and high supplemented Spetzler-Martin (sup-SM) score (P = .041) were independent factors of the poor outcome.IVH was common in ruptured AVMs and increased the poor outcomes in patients with the ruptured AVMs. The AVM-related IVH patients had a high incidence of hydrocephalus, which was associated with brain ischemia and SAH. Patients with lower Glasgow coma scale, lower sup-SM score, and smaller parenchymal hematoma had better long-term outcomes.

The use of neutrophil to lymphocyte ratio as a predictor for clinical outcomes in spontaneous intracerebral hemorrhage.

OBJECTIVE: Neutrophil to lymphocyte ratio (NLR) is used as an independent predictor for clinical outcomes in cancers, cardiovascular disorders and ischemic stroke. The prognostic role of NLR in spontaneous intracerebral hemorrhage (sICH) is still controversial. The aim of this report is to conduct a meta-analysis to evaluate the prognostic significance NLR in patients with sICH. MATERIALS AND METHODS: All related articles were searched on PubMed, EMBASE, Cochrane Central Register of Controlled Trials followed the PRISMA flow diagram. The quality of eligible studies were evaluated and the related data were extracted by two reviewers independently. The end points included the mortality and poor outcomes and subgroup analyses were performed. RESULTS: Five studies with 1944 subjects were included and had acceptable quality. The high NLR had a higher risk of in-hospital mortality (OR: 0.97; 95% CI: 0.94-0.99, p = 0.02) and 90-day mortality (OR: 2.43; 95% CI: 1.01-5.83, p = 0.047); without association with the poor outcomes (OR: 1.17; 95% CI: 0.93-1.47, p = 0.18). After subgroup analyses, the high NLR correlated with an increased 90-day mortality in the high cut-off group (OR: 1.56; 95% CI: 1.15-2.13, p = 0.005). The high NLR additionally predicts poor outcomes in smaller hematoma group (OR: 1.16; 95% CI: 1.01-1.32, p = 0.04) and the high cut-off group (OR: 2.20; 95% CI: 1.54-3.14, p < 0.001). CONCLUSIONS: The high NLR was significantly associated with in-hospital and 90-day mortality in patients with sICH. The NLR with cut-off of 7.5 had statistically significant potential for predicting mortality and poor outcomes, regardless of country, time of laboratory test and hematoma volumes.