Upregulated Expression of SSTR3 is Involved in Neuronal Apoptosis After Intracerebral Hemorrhage in Adult Rats.

Somatostatin which is a multifunctional growth hormone inhibitory neuropeptide shows diverse physiological effects, such as neurotransmission, cell growth, apoptosis, and endocrine signaling as well as exerts inhibitory effects on hormonal products and other secretory proteins. SSTR3 is a member of superfamily of somatostatin receptors (SSTR), which are G-protein-coupled plasma membrane receptors. Previous studies proved that SSTR3 regulates antiproliferative signaling and apoptosis in several cells. Here, we explored a potential role of SSTR3 in the regulation of neuronal apoptosis in the course of intracerebral hemorrhage (ICH). An ICH rat model was established and assessed by behavioral tests. We found SSTR3 was significantly upregulated surrounding the hematoma after ICH by Western blot and immunohistochemistry. Double immunofluorescence-manifested SSTR3 was strikingly increased in neurons, not astrocytes or microglia. Moreover, increasing SSTR3 level was found to be accompanied by the upregulation of p53, Bax, and active caspase-3 in vivo and in vitro studies. Furthermore, we detected that neuronal apoptosis marker active caspase-3 was co-localized with SSTR3 suggesting its potential role in neuronal apoptosis. In addition, in vitro study, revealed that SSTR3 knockdown specifically resulted in reducing neuronal apoptosis in PC12 cells, which further indicated that SSTR3 might exert its pro-apoptotic function on neuronal apoptosis. All our findings suggested that upregulated SSTR3 may be involved in neuronal apoptosis after ICH.

WY14643 Attenuates the Scopolamine-Induced Memory Impairments in Mice.

WY14643 is a selective agonist of peroxisome proliferator-activated receptor-α (PPAR-α) with neuroprotective and neurotrophic effects. The aim of this study was to evaluate the effects of WY14643 on cognitive impairments induced by scopolamine, a muscarinic acetylcholine receptor antagonist. We conducted different behavior tests including the Y-maze, Morris water maze, and passive avoidance test to measure the cognitive functions of C57BL/6J mice after scopolamine and WY14643 treatment. It was found that WY14643 injection significantly attenuated the scopolamine-induced cognitive impairments in these behavioral tests. Moreover, WY14643 treatment significantly enhanced the expression of brain-derived neurotrophic factor (BDNF) signaling cascade in the hippocampus. The usage of both PPAR-α inhibitor GW6471 and BDNF system inhibitor K252a fully prevented the memory-enhancing effects of WY14643. Therefore, these findings suggest that WY14643 could improve the scopolamine-induced memory impairments, and these effects are mediated by the activation of PPAR-α and BDNF system, thereby exhibiting a cognition-enhancing potential.

Truncated Dyrk1A aggravates neuronal apoptosis by inhibiting ASF-mediated Bcl-x exon 2b inclusion.

AIM: Aggravated neuronal loss, caused mainly by neuronal apoptosis, is observed in the brain of patients with Alzheimer's disease (AD) and animal models of AD. A truncated form of Dual-specific and tyrosine phosphorylation-regulated protein kinase 1A (Dyrk1A) plays a vital role in AD pathogenesis. Downregulation of anti-apoptotic Bcl-xL is tightly correlated with neuronal loss in AD. However, the molecular regulation of neuronal apoptosis and Bcl-x expression by Dyrk1A in AD remains largely elusive. Here, we aimed to explore the role and molecular mechanism of Dyrk1A in apoptosis. METHODS: Cell Counting Kit-8 (CCK8), flow cytometry, and TdT-mediated dUTP Nick-End Labeling (TUNEL) were used to check apoptosis. The cells, transfected with Dyrk1A or/and ASF with Bcl-x minigene, were used to assay Bcl-x expression by RT-PCR and Western blots. Co-immunoprecipitation, autoradiography, and immunofluorescence were conducted to check the interaction of ASF and Dyrk1A. Gene set enrichment analysis (GSEA) of apoptosis-related genes was performed in mice overexpressing Dyrk1A (TgDyrk1A) and AD model 5xFAD mice. RESULTS: Dyrk1A promoted Bcl-xS expression and apoptosis. Splicing factor ASF promoted Bcl-x exon 2b inclusion, leading to increased Bcl-xL expression. Dyrk1A suppressed ASF-mediated Bcl-x exon 2b inclusion via phosphorylation. The C-terminus deletion of Dyrk1A facilitated its binding and kinase activity to ASF. Moreover, Dyrk1a1-483 further suppressed the ASF-mediated Bcl-x exon 2b inclusion and aggravated apoptosis. The truncated Dyrk1A, increased Bcl-xS, and enrichment of apoptosis-related genes was observed in the brain of 5xFAD mice. CONCLUSIONS: We speculate that increased Dyrk1A and truncated Dyrk1A may aggravate neuronal apoptosis by decreasing the ratio of Bcl-xL/Bcl-xS via phosphorylating ASF in AD.

Expression of transforming growth factor-ß1 (TGF-ß1) and E-cadherin in glioma.

Gliomas are the most common tumors in the central nervous system. This study aims to investigate the expressions of transforming growth factor-ß1 (TGF-ß1) and epithelial cadherin (E-cadherin) in human brain glioma tissues and the correlation between their expressions with clinical pathological features and clinical significance. The expressions of mRNA or protein of TGF-ß1 and E-cadherin were detected by using reverse transcription polymerase chain reaction (RT-PCR) and Western blot in these tissues. Positive rates of the expression of TGF-ß1 and E-cadherin were 62.9 % and 38.6 % in brain tissues of glioma patients. The expressions of mRNA or protein for TGF-ß1 in brain glioma tissues were significantly higher than that in normal brain tissues (p < 0.01). Their expressions in well-differentiated glioma brain tissues were lower than those in poorly differentiated glioma brain tissues (p < 0.01). A negative correlation was found between TGF-ß1 and E-cadherin in brain glioma tissues (r = -0.302, p < 0.011). The cell numbers of C6 glioma through Transwell chambers were decreased significantly (p < 0.01), and the expression of TGF-ß1 was downregulated significantly (p < 0.01). However, the expression of E-cadherin was upregulated significantly (p < 0.01) after transfecting TGF-ß1 siRNA. The expression changes of TGF-ß1 and E-cadherin may be related to the emergence and the development of glioma. Downregulation of TGF-ß1 expression using siRNA can decrease the invasive capability of C6 glioma cells.

Overexpression of SASH1 related to the decreased invasion ability of human glioma U251 cells.

The purpose of this study was to investigate the impact of SAM- and SH3-domain containing 1 (SASH1) on the biological behavior of glioma cells, including its effects on cellular growth, proliferation, apoptosis, invasion, and metastasis, and thereby to provide an experimental basis for future therapeutic treatments. A pcDNA3.1-SASH1 eukaryotic expression vector was constructed and transfected into the U251 human glioma cell line. Using the tetrazolium-based colorimetric (MTT) assay, flow cytometry analyses, transwell invasion chamber experiments, and other methods, we examined the impact of SASH1 on the biological behaviors of U251 cells, including effects on viability, cell cycle, apoptosis, and invasion. Furthermore, the effect of SASH1 on the expression of cyclin D1, caspase-3, matrix metalloproteinase (MMP)-2, MMP-9, and other proteins was observed. Compared to the empty vector and blank control groups, the pcDNA3.1-SASH1 group of U251 cells exhibited significantly reduced cell viability, proliferation, and invasion (p < 0.05), although there was no difference between the empty vector and blank control groups. The pcDNA3.1-SASH1 group demonstrated a significantly higher apoptotic index than did the empty vector and blank control groups (p < 0.05), and the percentage of apoptotic cells was similar between the empty vector and blank control groups. In addition, the pcDNA3.1-SASH1 group expressed significantly lower protein levels of cyclin D1 and MMP-2/9 compared to the control and empty vector groups (p < 0.05) and significantly higher protein levels of caspase-3 than the other two groups (p < 0.05). Cyclin D1, caspase-3, and MMP-2/9 expression was unchanged between the empty vector and blank control groups. SASH1 gene expression might be related to the inhibition of the growth, proliferation, and invasion of U251 cells and the promotion of U251 cells apoptosis.

IDH1 mutation diminishes aggressive phenotype in glioma stem cells.

The R132H mutation in isocitrate dehydrogenase 1 (IDH1-R132H) is associated with better prognosis in glioma patients. Glioma stem cells (GSCs) in glioma are believed to be responsible for glioma growth and maintenance. However, the relation between the R132H mutation and GSCs is not fully understood. In the present study, GSC markers were detected in patients with IDH1-R132H or wild-type IDH1 (IDH1-wt) by tissue microarray immunohistochemistry (TMA-IHC). The relationship between the expression patterns of GSC markers and the clinicopathological characteristics in glioma were analyzed. To confirm this mutation's role in GSCs, the IDH1-R132H in GSCs isolated from glioblastoma patients with IDH1 mutations was overexpressed by using lentiviral constructs in vitro, and then the proliferation, differentiation, apoptosis, migration and invasion of the transfected GSCs were explored. At the molecular level, we detected Wnt/ß-catenin signaling expression to verify its role in regulating the cellular properties of GSCs. The results showed that the positive rate of GSCs in patients with IDH1-R132H was significantly less than that in patients with IDH1-wt. The positive rate of GSCs was correlated with IDH1 mutation, TNM stage and poor overall survive. After transfection in vitro, IDH1-R132H overexpression led to reduced GSCs proliferation, migration and invasion, inducing apoptosis and improving GSC differentiation, accompanied by a significant reduction in activity of ß-catenin. Several mediators, effectors and targets of the Wnt/ß-catenin signaling were downregulated. The data demonstrate that IDH1 mutation reduces the malignant progression of glioma by causing a less aggressive phenotype of GSCs which are involved in the Wnt/ß­catenin signaling.

Antidepressant-like effects of ginsenoside Rg3 in mice via activation of the hippocampal BDNF signaling cascade.

Current antidepressants are clinically effective only after several weeks of administration. Ginsenoside Rg3 is one component of ginsenosides, with a similar chemical structure to ginsenoside Rg1. Here, we investigated the antidepressant effects of Rg3 in mouse models of depression. The antidepressant actions of Rg3 were first examined in the forced swim test (FST) and tail suspension test (TST), and then assessed in the chronic social defeat stress (CSDS) model of depression. The changes in the hippocampal brain-derived neurotrophic factor (BDNF) signaling pathway after CSDS and Rg3 treatment were investigated. A tryptophan hydroxylase inhibitor and a BDNF signaling inhibitor were also used to determine the pharmacological mechanisms of Rg3. It was found that Rg3 produced antidepressant effects in the FST and TST without affecting locomotor activity. Rg3 also prevented the CSDS-induced depressive-like symptoms. Moreover, Rg3 fully restored the CSDS-induced decrease in the hippocampal BDNF signaling pathway, and use of the BDNF signaling inhibitor blocked the antidepressant effects of Rg3. In conclusion, ginsenoside Rg3 has antidepressant effects via promotion of the hippocampal BDNF signaling pathway.

GFAP expression is regulated by Pax3 in brain glioma stem cells.

Glioblastomas are understood to evolve from brain glioma stem cells (BGSCs), and yet the biology underlying this model of tumorigenesis is largely unknown. Paired box 3 protein (Pax3) is a member of the paired box (Pax) family of transcription factors that is normally expressed during embryonic development, but has recently been implicated in tumorigenesis. The present study demonstrated that Pax3 is differentially expressed in U87MG human glioma cell, BGSC and normal 1800 human astrocyte lines. Herein, we identified that the glial fibrillary acidic protein (GFAP), a major intermediate filament protein of mature astrocytes, is directly downregulated during the differentiation of BGSCs via the binding of Pax3 to the promoter region of GFAP. Moreover, siRNA silencing of Pax3 arrested BGSC differentiation, while overexpression of Pax3 promoted the differentiation in BGSCs. Furthermore, we studied the cell proliferation, invasion, apoptosis, differentiation and expression of Pax3 and GFAP in Pax3 siRNA-knockdown and Pax3-overexpressing BGSC models by CCK-8, Transwell migration, flow cytometry and western blot assays. The results indicate that Pax3 regulates GFAP expression, and that Pax3 may contribute to the evolution of BGSCs towards malignancy.

Correlation of C-X-C chemokine receptor 2 upregulation with poor prognosis and recurrence in human glioma.

C-X-C chemokine receptor 2 (CXCR2), a member of the G-protein-coupled receptor family, is an interleukin-8 receptor and results in the activation of neutrophils. To date, CXCR2 has been identified with many cell events, including inflammation, neovascularization, metastasis, and cell carcinogenesis. This study aimed to investigate alterations in the expression of CXCR2 in patients with brain gliomas and relationships with pathological grades and clinicopathological characteristics. Brain tissue specimens from 60 patients with glioma and 15 patients undergoing surgery for epilepsy (controls) were detected using streptavidin-perosidase immunohistochemistry. Western blotting was used to evaluate CXCR2 protein levels with fresh tissues derived from glioma cases or controls. Correlations between CXCR2 expression and clinicopathological characteristics were analyzed using SPSS software. The results showed high-grade gliomas with high CXCR2 expression as compared with normal tissues. The expression of CXCR2 was significantly related to high grades and recurrence of tumor but not to age or sex. During an in vitro wound healing assay, U251 migration was reduced when the CXCR2-specific inhibitor SB225002 was applied. Our results suggested that the high expression of CXCR2 in gliomas was closely correlated to the degree of malignancy and recurrence and that CXCR2 inhibition decreased the migration of glioma cells. Therefore, CXCR2 may serve as a potential therapeutic target for the recurrence and migration of gliomas.

Impacts of phosphatase and tensin homology deleted on chromosome ten (PTEN)-inhibiting chitosan scaffold on growth and differentiation of neural stem cells.

OBJECTIVE: The aim of this study was to investigate growth and differentiation of neural stem cells (NSCs) on the phosphatase and tensin homology deleted on chromosome ten (PTEN)-inhibitor-adsorbed chitosan scaffold. METHODS: NSCs were divide into the chitosan group and the control groups, and performed CCK-8 test on 1(st), 3(rd) and 7(th) d to compare the proliferation between the 2 groups. The chitosan scaffold adsorbed PTEN inhibitor bpv (pic), and the empty scaffold was used as the control for co-culture of NSCs, immunofluorescence staining was performed on 7(th) d to detect the differentiation of NSCs on the scaffold. RESULTS: The results of CCK-8 test showed no significant difference in the absorbance between the 2 groups. Immunofluorescence staining showed that the NSCs numbers of the bpv scaffold group were more than the empty scaffold group, among which the anti-glial fibrillary acidic protein (GFAP) positive cells were less than the empty scaffold group, while the anti-ß-Tubulin III positive cells were more than the empty scaffold group, the two groups both showed rare anti-receptor-interacting protein (RIP) positive cells. CONCLUSIONS: Chitosan scaffold exhibited good compatibility to NSCs, the PTEN-inhibitor-adsorbed chitosan scaffold could promote the migration of NSCs towards the scaffold and their differentiation towards neurons.

A comparison of different transarterial embolization techniques for direct carotid cavernous fistulas: a single center experience in 32 patients.

OBJECTIVE: Transarterial treatment of direct carotid cavernous fistulas (DCCF) via embolic materials has been well documented. This study reports, validates, and compares with existing literature our experience treating DCCFs via endovascular approaches by using detachable balloons, coils, and covered stents. METHODS: Between June 2006 to October 2011, 32 patients (21 male, 11 female) with 32 DCCFs (30 traumatic, 2 spontaneous cavernous ICA aneurysms) were embolized endovascularly. Followup was performed for at least 6 months. RESULTS: Among the 32 DCCFs, 21 (65.6%) were embolized using detachable balloons, eight (25.0%) with coils, one (3.1%) with balloons and coils, and two (6.3%) with covered stents. Complete DCCF obliteration was achieved in 31 (96.9%) cases. One fistula failed to respond due to premature balloon detachment. Intracranial bruit in 31 (100%) chemosis and exophthalmos in 28 (100%) cases resolved after embolization. Visual acuity and oculomotor palsy improved in 18 (90%) and 18 (69.2%) cases, respectively. There was no evidence of DCCF recurrence. Thirteen DCCFs were followed up by MRI and five by DSA. In these cases, four (4/13, 30.8%) balloon-embolized DCCFs showed pseudoaneurysms. Three patients were asymptomatic; one had minor left oculomotor palsy. CONCLUSIONS: Our results correlate and reinforce literature regarding endovascular treatment of DCCFs. Application of Transarterial embolization with detachable balloons, despite extensive use has been decreasing. Coil embolization is an effective and safe alternative for treatment, especially when balloon embolization fails. Covered stent placement may be used as another alternative for selected cases.

Chemokines mediate mesenchymal stem cell migration toward gliomas in vitro.

Previous studies have demonstrated the tremendous tropism of mesenchymal stem cells (MSCs) for malignant gliomas, making these cells a potential vehicle for delivery of therapeutic genes to disseminated glioma cells. However, the mechanisms underlying the tropism of MSCs for gliomas remain poorly defined. It has been suggested that malignant gliomas secrete a variety of chemokines, including macrophage chemoattractant protein-1 (MCP-1) and stromal cell-derived factor-1 alpha (SDF-1 alpha). We isolated and cultured MSCs from rat bone marrow and found that these cells express CCR2 and CXCR4, the respective receptors for MCP-1 and SDF-1 alpha. In vitro analysis revealed that MCP-1 and SDF-1 alpha induce the migration of MSCs. Futhermore, neutralization data suggest that MCP-1 and SDF-1 alpha play a role in the mediation of MSC migration toward gliomas. These results highlight the potential of these cells as a tumor targeting strategy for glioma gene therapy.

Microsurgical excision of the craniocervical neurenteric cysts by the far-lateral transcondylar approach: case report and review of the literature.

Neurenteric cysts in the anterior craniocervical junction (CCJ) region can be found in extremely rare cases. We report one case with craniocervical neurenteric cyst that was excised by the far-lateral transcondylar (FLT) approach. A 43-year-old man presented with a history of recurrent episodes of mild neck pain and dysesthesia in his bilateral hands of 2 years' duration with rapid deterioration 3 weeks prior to admission. Magnetic resonance imaging (MRI) of the CCJ region revealed a well-defined intradural cystic lesion located ventral from the pontomedullary junction to C1 vertebra with medulla and C1 cord compression. This patient underwent total excision of the lesion via the FLT approach without any postoperative neurological deficits, and the histopathologic diagnosis was neurenteric cyst. Follow-up MRI has revealed no evidence of recurrence. The clinical features, imaging studies, and surgical approach options involved in resecting craniocervical neurenteric cysts are discussed, along with a review of the literature.