Microvascular decompression using a fully transcranial neuroendoscopic approach.

OBJECTIVE: To evaluate the effectiveness and safety of microvascular decompression (MVD) using a fully transcranial neuroendoscopic approach. METHODS: Thirty-one patients who underwent MVD using a fully transcranial neuroendoscopic approach in our department between May 2016 and September 2019 were retrospectively reviewed. RESULTS: All patients successfully underwent MVD, and immediate pain relief was achieved in all 17 cases of trigeminal neuralgia (TGH) and 3 cases of glossopharyngeal neuralgia (GPN). Hemifacial spasm (HFS) was completely resolved in all 11 patients. No mortality or permanent complication was seen. CONCLUSIONS: The endoscope is a useful tool for confirming vascular conflict identified by the microscope and is helpful in detecting the vessel responsible for neuralgia without retracting the brain and nerves. MVD using a fully transcranial neuroendoscopic approach is an effective and safe alternative to endoscopic-assisted MVD and traditional MVD.

Blocking Cross-Species Secondary Binding When Performing Double Immunostaining With Mouse and Rat Primary Antibodies.

Immunostaining is a powerful technique and widely used to identify molecules in tissues and cells, although critical steps are necessary to block cross-reaction. Here we focused on an overlooked cross immunoreactivity issue where a secondary antibody (secondary) cross-reacts with a primary antibody (primary) from a different species. We first confirmed the previously reported cross-species binding of goat anti-mouse secondary to rat primary. This was accomplished by staining with a rat primary against glial fibrillary acidic protein (GFAP) and visualizing with goat (or donkey) anti-mouse secondary. We then further revealed the converse cross-species binding by staining with a mouse primary against neuronal nuclear protein (NeuN) and visualizing with anti-rat secondaries. We speculate that mouse and rat primaries share antigenicity, enabling either secondary to recognize either primary. To block this cross-species binding in double staining experiments, we compared three protocols using mouse anti-NeuN and rat anti-GFAP, two primaries whose antigens have non-overlapping distributions in brain tissues. Simultaneous staining resulted in cross-species astrocytic staining (anti-mouse secondary to rat anti-GFAP primary) but no cross-species neuronal staining (anti-rat secondary to mouse anti-NeuN primary). Cross-species astrocytic staining was missing after sequential same-species staining with mouse anti-NeuN primary, followed by rat anti-GFAP. However, cross-species astrocytic staining could not be diminished after sequential same-species staining with rat anti-GFAP primary, followed by mouse anti-NeuN. We thus hypothesize that a competition exists between anti-mouse and anti-rat secondaries in their binding to both primaries. Single staining for NeuN or GFAP visualized with dual secondaries at different dilution ratio supported this hypothesis.

Hemorrhagic stroke treated by transcranial neuroendoscopic approach.

Hemorrhagic stroke (HS) is usually treated under microscopy, but recently, an increasing number of cases have been treated under neuroendoscopy. The objective of this study was to explore the feasibility and efficacy of a transcranial neuroendoscopic approach for HS. Based on etiology and clinical features, 203 HS patients were classified into two groups, with 100 patients in the primary HS (PHS) group and 103 patients in the secondary HS (SHS) group. All patients were treated either by full neuroendoscopy (FNE) or by neuroendoscopy combined with microsurgery (ECM). Outcomes were assessed according to the Glasgow Coma Scale (GCS) at discharge, and the rate of good plus excellent results was recorded as the GE rate to assess the treatment effect. All 203 patients underwent surgery successfully, with 165 patients who underwent FNE and 38 patients who underwent ECM. No patients died within 3 days after surgery, and the surgery-related mortality rate was 0%, but a total of 4 patients died by discharge, and the overall mortality rate was 1.97%. A total of 133 patients showed an excellent result and 16 showed a good result, for a total GE rate of 73%. Neuroendoscopy can provide excellent illumination, clear visualization, and multiangle views in HS. The transcranial neuroendoscopic approach is feasible and safe for both PHS and SHS and is very effective for hematoma evacuation. However, some aneurysms and most arteriovenous malformations and arteriovenous fistulas require ECM.

Genetic deletion of Rnd3 suppresses apoptosis through NF­κB signaling in the brain.

Rho family GTPase 3 (RND3) is involved in multiple physiological activities involving the Rho kinase­dependent signaling pathway. The present study revealed a novel role of RND3 in the regulation of apoptosis in the brain. Using immunofluorescence and TUNEL assays, a decreased rate of brain apoptosis was observed in Rnd3­knockout mice. In addition, the function of RND3 in promoting apoptosis was determined in PC12 cells by immunoblotting assays and flow cytometry analysis in RNA interference and overexpression experiments. Furthermore, the present study demonstrated that Rnd3 and P65 protein interacted using immunoprecipitation analysis, and Rnd3 regulated apoptosis via its association with NF­κB P65. Notably, Rnd3 blocked the anti­apoptotic action of NF­κB P65 in vitro by downregulating P65. Therefore, RND3­NF­κB P65 represents a novel signaling pathway in the regulation of brain apoptosis. The present study suggested an alternative approach for the treatment of neurodegenerative diseases through regulation of apoptosis via the RND3­NF­κB P65 signaling pathway in the central nervous system.

Pathogenesis, Assessments, and Management of Chemotherapy-Related Cognitive Impairment (CRCI): An Updated Literature Review.

There are various cancer treatments at present, and chemotherapy is one of the main methods. Chemotherapy-related cognitive impairment (CRCI), as one of the side effects of chemotherapy, has gradually attracted the attention of more and more researchers. CRCI has been verified by subjective reports and objective neuropsychological tests so far. But oncologists' understanding of it and its treatments are still incomplete. In this review, we mainly give a comprehensive overview of the mechanism of CRCI, then describe a variety of evaluation methods, and finally summarize the treatment approaches under current medical conditions and compare it with an excellent article published in 2015 with the aim of providing directions for future research and better understanding of CRCI for clinicians.

Cognition Deficits in Parkinson's Disease: Mechanisms and Treatment.

Parkinson's disease (PD) is the second most common progressive neurodegenerative disorder mainly in middle-elderly population, which represents diverse nonmotor symptoms (NMS) besides such well-documented motor symptoms as bradykinesia, resting tremor, rigidity, and postural instability. With the advancement of aging trend worldwide, the global prevalence of PD is mounting up year after year. Nowadays, accumulating lines of studies have given a comprehensive and thorough coverage of motor symptoms in PD. Yet much less attention as compared has been paid to the nonmotor symptoms of PD, such as cognition deficits. Of note, a patient with PD who suffers from cognitive impairment may harbour a statistically significantly higher risk of progressing toward dementia, which negatively affects their life expectancy and daily functioning and overall lowers the global quality of life. Furthermore, it is a widely held view that cognitive dysfunction does not just occur in the late stage of PD. On the basis of numerous studies, mild cognitive impairment (MCI) is a harbinger of dementia in PD, which is observed as an intermediate state with considerable variability; some patients remain stable and some even revert to normal cognition. Considered that the timing, profile, and rate of cognitive impairment vary greatly among PD individuals, it is extremely urgent for researchers and clinicians alike to identify and predict future cognitive decline in this population. Simultaneously, early screening and canonical management of PD with cognitive deficits are very imperative to postpone the disease progression and improve the prognosis of patients. In our review, we focus on a description of cognitive decline in PD, expound emphatically the pathological mechanisms underlying cognition deficits in PD, then give a comprehensive overview of specific therapeutic strategies, and finally dissect what fresh insights may bring new exciting prospect for the subfield.

Tianzhi granule improves cognition and BPSD of vascular dementia: a randomized controlled trial.

BACKGROUND AND PURPOSE: Tianzhi granule (TZ) is usually used for patients with vascular dementia (VaD) in China. The aim was to assess the effect of TZ by a randomized clinical trial (RCT). METHODS: A 24-week RCT was conducted in 16 centres. Participants were grouped into TZ, donepezil or placebo. The co-primary outcomes were the Vascular Dementia Assessment Scale-cognitive subscale (VADAS-cog) and Clinician's Interview-based Impression of Change-plus caregiver information (CIBIC-plus). RESULTS: A total of 543 patients with mild to moderate VaD were enrolled, of whom 242 took TZ granules, 241 took donepezil, and 60 took placebo. The least-squares mean changes from baseline and 95% CI were 6.20 (5.31, 7.09) (TZ group), 6.53 (5.63, 7.42) (donepezil group) and 3.47 (1.76, 5.19) (placebo group), both TZ and donepezil showed small but significantly improvement compared with placebo group. The percent of improvement on the global impression which was measured by CIBIC-plus was 73.71% in TZ and 58.18% in placebo, there was significant different between TZ and placebo group (P = 0.004). No significant differences were observed between TZ and donepezil. No significant differences of adverse events were found. CONCLUSIONS: TZ and donepezil could bring symptomatic benefit for mild to moderate VaD. Trial registration The protocol had retrospectively registered at clinical trial.gov, Unique identifier: NCT02453932, date of registration: May 27, 2015; https://www.clinicaltrials.gov/ct2/show/NCT02453932?term=NCT02453932&rank=1.

Effects of low-frequency repetitive transcranial magnetic stimulation on depression- and anxiety-like behaviors in epileptic rats.

Low-frequency repetitive transcranial magnetic stimulation (rTMS) has been considered as a treatment option for depression and anxiety. However, its role in epilepsy comorbid with depression and anxiety is unclear. Therefore, we evaluated whether low-frequency rTMS can alleviate depression- and anxiety-like behavior in epileptic rats. Forty-eight adult rats were allocated at random to four groups: Control, Pentylenetetrazol (PTZ), PTZ-rTMS and PTZ-Sham. The control group received intraperitoneal injections of normal saline, while the other groups received intraperitoneal injections of pentylenetetrazol (35 mg/kg/d) once a day for 15 days. Low-frequency rTMS or sham stimulation were administered to the PTZ-rTMS and PTZ-Sham group, respectively, over the two-week period. The open-field test (OFT), elevated plus-maze test (EPM) and forced swimming test (FST) were carried out before the experiment, on the 8th and 15th day to assess depression- and anxiety-like behavior in the rats. Two weeks of low-frequency rTMS treatment could not impair the increases of seizure severity in epileptic rats. However, relative to the PTZ and PTZ-Sham group, the two-week low-frequency rTMS treatment significantly reduced the immobility time in the forced swimming test and attenuated the progressive decrease in total distance traveled, frequency of rearing, velocity in the open-field test, number of entries in the open arms (%) and the time spent in the open arms (%) in the elevated plus-maze test of the PTZ-rTMS group. We proposed that low-frequency rTMS can benefit epileptic rats via amelioration of comorbid depression and anxiety, but it can not alleviate the seizure severity.

Efficacy and Safety of Toutongning Capsule in Patients with Migraine: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial.

Objective: Toutongning (TTN) capsule, a Chinese patent medicine, is used as a prophylactic treatment for migraine. The present study was conducted as a postmarketing evaluation of the efficacy and safety of TTN capsule. Design: A randomized, double-blind, placebo-controlled trial. Location: Patients recruited from 14 medical centers in China from May 2014 to August 2015. Subjects: Patients between 18 and 65 years of age with a diagnosis of migraine. Interventions: The patients were randomly assigned to receive either TTN (1200 mg, three times daily) or a matched placebo (1:1) for 4 weeks. Outcome measures: The primary outcome measured was a minimum 50% reduction in the frequency of headaches from the 4-week baseline period to the last 4 weeks of the 12-week trial. Secondary outcomes included duration, days, and visual analog score of headache attack, interval between headache attacks, usage of acute analgesics, and score on the Headache Impact Test-6. In addition, all patients were evaluated for adverse events (AEs). Results: This study initially enrolled 400 patients; a total of 378 participants completed the experiment while fulfilling all study requirements. TTN had a superior effect compared with the placebo on both the primary and secondary outcome measures without any serious AEs or unexpected side effects. Conclusion: TTN can effectively prevent the occurrence of migraine headaches and is well-tolerated and safe. TTN may exhibit a persistent therapeutic effect even after cessation of use. Trial Registration number: ChiCTR-IPR-15007058.

Small GTPase RHOE/RND3, a new critical regulator of NF-κB signalling in glioblastoma multiforme?

OBJECTIVES: Abnormal activation of NF-κB signalling is a major mechanism of apoptosis resistance in glioblastoma multiforme (GBM). Therefore, better understanding of the regulation of NF-κB signalling has a significant impact for GBM therapy. Here, we uncovered a critical role of the small GTPase RND3 in regulating the p65 subunit of NF-κB and NF-κB signalling in GBM. MATERIALS AND METHODS: Human GBM samples, GBM cells and a human orthotopic GBM-xenografted animal model were used. The mechanisms of RND3 in regulation of NF-κB signalling and GBM cell apoptosis were examined by luciferase assay, quantitative PCR, immunostaining, immunoblotting, immunofluorescence, coimmunoprecipitation, TUNEL staining, JC-1 analysis and flow cytometry. RESULTS: Overexpression of RND3 led to reduced p65 activity in GBM-cultured cells and a GBM animal model, indicating that the NF-κB pathway is negatively regulated by RND3 in GBM. Mechanistically, we found that RND3 bound p65 and promoted p65 ubiquitination, leading to decreased p65 protein levels. Furthermore, RND3 enhanced cleaved caspase 3 levels and promoted apoptosis in GBM cells, and RND3 expression was positively correlated with cleaved caspase 3 and IL-8 in human GBM samples. The effect of RND3 on promoting apoptosis disappeared when p65 ubiquitination was blocked by protease inhibitor carfilzomib or upon co-expression of ectopic p65. CONCLUSIONS: RND3 binds p65 protein and promotes its ubiquitination, resulting in reduced p65 protein expression and inhibition of NF-κB signalling to induce GBM cell apoptosis.

Evacuation of chronic and subacute subdural hematoma via transcranial neuroendoscopic approach.

OBJECTIVE: To evaluate the effectiveness and safety of neuroendoscopic surgery for chronic or subacute subdural hematoma. PATIENTS AND METHODS: Between September 2016 and September 2018, neuroendoscopic surgery was performed on 25 patients with chronic and subacute subdural hematoma. Hematoma evacuation was performed with a 0°, 4 mm diameter rigid neuroendoscope via a transcranial neuroendoscopic approach. RESULTS: All patients successfully underwent neuroendoscopic surgery, and no surgical complications or rebleeding was observed. Postoperative computed tomography scans showed that the hematoma was successfully evacuated. All patients had recovered well at discharge, the observed 30-day mortality rate was 0%, and no patients suffered recurrence for 2-26 months after surgery. CONCLUSION: Neuroendoscopic surgery was a safe and effective approach for the treatment of chronic and subacute subdural hematoma. This approach has the advantages of decent visualization and minimal invasiveness and could reduce recurrence and the mortality rate.

Randomized controlled trial of cognitive behavioural therapy for depressive and anxiety symptoms in Chinese women with breast cancer.

Depressive and anxiety symptoms are frequently observed in breast cancer survivors. To date, few randomized controlled trials have been conducted on the efficacy of cognitive behavioural therapy (CBT) for depressive and anxiety symptoms in Chinese population. This study aims to verify the efficacy of CBT in Chinese breast cancer survivors. Women (n = 392) with breast cancer were randomly assigned to 3 groups: CBT (n = 98), self-care management (SCM, n = 98), and usual care (UC, n = 196) using the proportion 1:1:2. Women in the CBT and SCM groups received a series of nine sessions for 12 weeks, while women in the UC group received their usual medical care only. Depressive and anxiety symptoms were assessed using the Hamilton Depression Rating Scale (HAMD) and the Hamilton Anxiety Scale (HAMA) score at baseline, 2, 4, 8, 12, 16, and 24 weeks. A significant intergroup difference was found in the HAMD and HAMA scores. Women in the CBT group showed significantly less depressive and anxiety symptoms compared with women in the SCM and UC groups over time. In conclusion, this study supports the efficacy of CBT for depressive and anxiety symptoms in Chinese breast cancer survivors.

Effects of cognitive behavioral therapy for depression on improving insomnia and quality of life in Chinese women with breast cancer: results of a randomized, controlled, multicenter trial.

PURPOSE: Cognitive behavioral therapy (CBT) for depression had been found to be effective in reducing depressive and anxiety symptoms in breast cancer survivors. It is not known whether CBT for depression would also improve insomnia and quality of life (QOL). The aim of this study was to investigate whether CBT for depression would improve insomnia and QOL in a randomized controlled multicenter trial. PATIENTS AND METHODS: In this study, breast cancer survivors (n=392) were randomly allocated to the following three groups: CBT (n=98), self-care management (SCM, n=98), and usual care (UC, n=196) in a ratio of 1:1:2. CBT and SCM received a series of nine sessions for 12 weeks, whereas UC received UC only. Insomnia and QOL were evaluated using Athens Insomnia Scale (AIS) and Functional Assessment of Cancer Therapy-Breast (FACT-B) questionnaire at baseline, 4, 12, and 24 weeks. RESULTS: There was a significant intergroup difference in AIS and FACT-B scores (both P<0.01). CBT showed less insomnia problems and better overall QOL compared with those in SCM and UC (both P<0.01). No significant differences were found between SCM and UC in insomnia problems and overall QOL. Moreover, the effects of CBT on insomnia and QOL were maintained during the follow-up period. CONCLUSION: CBT for depression can be effective in improving insomnia problems and QOL in the Chinese breast cancer survivors.

Association between depression and the subsequent risk of Parkinson's disease: A meta-analysis.

BACKGROUND: Observational studies, including recent large cohort studies, have reported an association between depression and the risk of Parkinson's disease (PD); however, conclusions were inconsistent. Clarifying this relation might improve the understanding of risk factors for and the disease mechanisms in PD. Therefore, we performed a meta-analysis to examine whether depression is associated with an increased risk of PD. METHODS: A literature search in the PubMed, EMBASE, Scopus, PsycINFO and Web of Science databases was undertaken through March 2018, looking for observational studies evaluating the association between depression and the risk of PD. Pooled relative risk (RR) estimates and 95% confidence intervals (CIs) were calculated using a random-effects model. Subgroup analyses and sensitivity analyses were also performed. RESULTS: A random-effects meta-analysis of 5 cohort studies and 6 case-control studies demonstrated a significant positive association between depression and a subsequent risk of PD (RR, 2.20; 95% CI, 1.87-2.58), and it was consistent across subgroups. Furthermore, sensitivity analysis confirmed the stability of the results; visual examination of funnel plots and Begg's and Egger's tests showed no evidence of publication bias. CONCLUSIONS: Our meta-analysis demonstrated that persons with depression exhibited an increased risk of a subsequent PD diagnosis. The pathophysiological and psychological mechanisms underlying this association are still unclear and warrant further research.

Genetic deletion of Rnd3 in neural stem cells promotes proliferation via upregulation of Notch signaling.

Rnd3, a Rho GTPase, is involved in the inhibition of actin cytoskeleton dynamics through the Rho kinase-dependent signaling pathway. We previously demonstrated that mice with genetic deletion of Rnd3 developed a markedly larger brain compared with wild-type mice. Here, we demonstrate that Rnd3 knockout mice developed an enlarged subventricular zone, and we identify a novel role for Rnd3 as an inhibitor of Notch signaling in neural stem cells. Rnd3 deficiency, both in vivo and in vitro, resulted in increased levels of Notch intracellular domain protein. This led to enhanced Notch signaling and promotion of aberrant neural stem cell growth, thereby resulting in a larger subventricular zone and a markedly larger brain. Inhibition of Notch activity abrogated this aberrant neural stem cell growth.

2',3'-Dideoxycytidine Protects Dopaminergic Neurons in a Mouse Model of Parkinson's Disease.

DNA polymerase-ß (DNA pol-ß) plays a crucial role in the pathogenesis of Parkinson's disease (PD). The aim of this study was to investigate the neuroprotective effects of a DNA polymerase-ß inhibitor 2',3'-dideoxycytidine (DDC) in PD models. In the in vitro studies, primary cultured neurons were challenged with 1-methyl-4-phenylpyridinium ion (MPP+). The expression of DNA pol-ß was assessed using western blot. The neuroprotective effect of DNA pol-ß knockdown and DNA pol-ß inhibitor DDC was determined using cell viability assay and caspase-3 activity assay. We found that MPP+ induced neuronal death and the activation of caspase-3 in a dose-dependent manner. The expression of DNA pol-ß increased after the neurons were exposed to MPP+. DNA pol-ß siRNA or DNA pol-ß inhibitor DDC attenuated neuronal death induced by MPP+. In the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD, MPTP treatment triggered behavioral deficits and nigrostriatal lesions. Pretreatment with DDC attenuated MPTP-induced behavioral deficits, dopaminergic neuronal death and striatal dopamine depletion in the MPTP mouse model. These results indicate that DNA pol-ß inhibitors may present a novel promising therapeutic option for the neuroprotective treatment of PD.

The Interrelation between Reactive Oxygen Species and Autophagy in Neurological Disorders.

Neurological function deficits due to cerebral ischemia or neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD) have long been considered a thorny issue in clinical treatment. Recovery after neurologic impairment is fairly limited, which poses a major threat to health and quality of life. Accumulating evidences support that ROS and autophagy are both implicated in the onset and development of neurological disorders. Notably, oxidative stress triggered by excess of ROS not only puts the brain in a vulnerable state but also enhances the virulence of other pathogenic factors, just like mitochondrial dysfunction, which is described as the culprit of nerve cell damage. Nevertheless, autophagy is proposed as a subtle cellular defense mode against destructive stimulus by timely removal of damaged and cytotoxic substance. Emerging evidence suggests that the interplay of ROS and autophagy may establish a determinant role in the modulation of neuronal homeostasis. However, the underlying regulatory mechanisms are still largely unexplored. This review sets out to afford an overview of the crosstalk between ROS and autophagy and discusses relevant molecular mechanisms in cerebral ischemia, AD, and PD, so as to provide new insights into promising therapeutic targets for the abovementioned neurological conditions.

RND3 promotes Snail 1 protein degradation and inhibits glioblastoma cell migration and invasion.

Activation of Snail1 signaling promotes the migration and invasion of multiple tumors, including glioblastoma multiforme (GBM). However, the molecular mechanism that augments Snail1 signaling during GBM cell migration and invasion remains largely unknown. Identification of the factors that regulate Snail1 signaling is critical to block tumor cell migration and invasion. By screening human GBM specimens, we found that the expression levels of small GTPase RND3 positively correlated with the expression levels of E-cadherin and claudin, the glioblastoma migration biomarkers negatively regulated by Snail1. Downregulation of E-cadherin and claudin has been associated with the migration and invasion of GBM cells. We demonstrated that RND3 functioned as an endogenous inhibitor of the Snail-directed transcriptional regulation. RND3 physically interacted with Snail1 protein, enhanced Snail1 ubiquitination, and facilitated the protein degradation. Forced expression of RND3 inhibited Snail1 activity, which in turn blocked glioblastoma cell migration and invasion in vitro in cell culture and in vivo in GBM xenograft mice. In contrast, downregulation of RND3 augmented Snail1 activity, and subsequently decreased E-cadherin expression, eventually promoted glioblastoma cell migration and invasion. The pro-migration induced by RND3 downregulation was attenuated by Snail1 knockdown. The findings partially explain why Snail1 activity is augmented in GBM, and defines a new function of RND3 in GBM cell migration and invasion.

Verification of the Cross Immunoreactivity of A60, a Mouse Monoclonal Antibody against Neuronal Nuclear Protein.

A60, the mouse monoclonal antibody against the neuronal nuclear protein (NeuN), is the most widely used neuronal marker in neuroscience research and neuropathological assays. Previous studies identified fragments of A60-immunoprecipitated protein as Synapsin I (Syn I), suggesting the antibody will demonstrate cross immunoreactivity. However, the likelihood of cross reactivity has never been verified by immunohistochemical techniques. Using our established tissue processing and immunofluorescent staining protocols, we found that A60 consistently labeled mossy fiber terminals in hippocampal area CA3. These A60-positive mossy fiber terminals could also be labeled by Syn I antibody. After treating brain slices with saponin in order to better preserve various membrane and/or vesicular proteins for immunostaining, we observed that A60 could also label additional synapses in various brain areas. Therefore, we used A60 together with a rabbit monoclonal NeuN antibody to confirm the existence of this cross reactivity. We showed that the putative band positive for A60 and Syn I could not be detected by the rabbit anti-NeuN in Western blotting. As efficient as Millipore A60 to recognize neuronal nuclei, the rabbit NeuN antibody demonstrated no labeling of synaptic structures in immunofluorescent staining. The present study successfully verified the cross reactivity present in immunohistochemistry, cautioning that A60 may not be the ideal biomarker to verify neuronal identity due to its cross immunoreactivity. In contrast, the rabbit monoclonal NeuN antibody used in this study may be a better candidate to substitute for A60.

Downregulation of RND3/RhoE in glioblastoma patients promotes tumorigenesis through augmentation of notch transcriptional complex activity.

Activation of Notch signaling contributes to glioblastoma multiform (GBM) tumorigenesis. However, the molecular mechanism that promotes the Notch signaling augmentation during GBM genesis remains largely unknown. Identification of new factors that regulate Notch signaling is critical for tumor treatment. The expression levels of RND3 and its clinical implication were analyzed in GBM patients. Identification of RND3 as a novel factor in GBM genesis was demonstrated in vitro by cell experiments and in vivo by a GBM xenograft model. We found that RND3 expression was significantly decreased in human glioblastoma. The levels of RND3 expression were inversely correlated with Notch activity, tumor size, and tumor cell proliferation, and positively correlated with patient survival time. We demonstrated that RND3 functioned as an endogenous repressor of the Notch transcriptional complex. RND3 physically interacted with NICD, CSL, and MAML1, the Notch transcriptional complex factors, promoted NICD ubiquitination, and facilitated the degradation of these cofactor proteins. We further revealed that RND3 facilitated the binding of NICD to FBW7, a ubiquitin ligase, and consequently enhanced NICD protein degradation. Therefore, Notch transcriptional activity was inhibited. Forced expression of RND3 repressed Notch signaling, which led to the inhibition of glioblastoma cell proliferation in vitro and tumor growth in the xenograft mice in vivo. Downregulation of RND3, however, enhanced Notch signaling activity, and subsequently promoted glioma cell proliferation. Inhibition of Notch activity abolished RND3 deficiency-mediated GBM cell proliferation. We conclude that downregulation of RND3 is responsible for the enhancement of Notch activity that promotes glioblastoma genesis.