HP1α is highly expressed in glioma cells and facilitates cell proliferation and survival.

Epigenetic alteration plays critical roles in gliomagenesis by regulating gene expression through modifications of Histones and DNA. Trimethylation of H3K9, an essential repressed transcription mark, and one of its methyltransferase, SUV39H1, are implicated in glioma pathogenesis and progression. We find that the protein level of HP1α, a reader of H3K9me3 is elevated in cultured glioma cell lines and glioma tissues. H3K9me3 is also upregulated. Depletion of HP1α and SUV39H1 weakens glioma cell proliferation capacity and results in apoptosis of cells. Furthermore, we find that HP1α and H3K9me3 are enriched in the FAS and PUMA promoters, which suggests that upregulated HP1α and H3K9me3 contribute to cell survival by suppressing apoptotic activators. These data suggests that up-regulated HP1α and H3K9me3 in glioma cells are functionally associated with glioma pathogenesis and progression and may serve as novel biomarkers for diagnostic and therapeutic targeting of brain tumors.

A Novel Anterior Transpedicular Screw Artificial Vertebral Body System for Lower Cervical Spine Fixation: A Finite Element Study.

A finite element model was used to compare the biomechanical properties of a novel anterior transpedicular screw artificial vertebral body system (AVBS) with a conventional anterior screw plate system (ASPS) for fixation in the lower cervical spine. A model of the intact cervical spine (C3-C7) was established. AVBS or ASPS constructs were implanted between C4 and C6. The models were loaded in three-dimensional (3D) motion. The Von Mises stress distribution in the internal fixators was evaluated, as well as the range of motion (ROM) and facet joint force. The models were generated and analyzed by mimics, geomagic studio, and ansys software. The intact model of the lower cervical spine consisted of 286,382 elements. The model was validated against previously reported cadaveric experimental data. In the ASPS model, stress was concentrated at the connection between the screw and plate and the connection between the titanium mesh and adjacent vertebral body. In the AVBS model, stress was evenly distributed. Compared to the intact cervical spine model, the ROM of the whole specimen after fixation with both constructs is decreased by approximately 3 deg. ROM of adjacent segments is increased by approximately 5 deg. Facet joint force of the ASPS and AVBS models was higher than those of the intact cervical spine model, especially in extension and lateral bending. AVBS fixation represents a novel reconstruction approach for the lower cervical spine. AVBS provides better stability and lower risk for internal fixator failure compared with traditional ASPS fixation.

Mechanism of ischemic brain injury repair by endothelial progenitor cell­derived exosomes.

Ischemic stroke is a refractory disease that seriously endangers human health and life. The main treatment aim of stroke is to alleviate brain injury. The present study aimed to investigate the effects and mechanisms of endothelial progenitor cell (EPC)­derived exosomes in repairing ischemic brain injury. Sprague­Dawley rat models of cerebral ischemia­reperfusion (IR) injury were established by middle cerebral artery occlusion. The IR model rats were then treated with PBS, EPC or exosomes; untreated and Sham rats were used as control. EPCs were obtained from tibias and femurs, and exosomes were isolated from the EPCs and characterized. To measure brain injury, 2,3,5­triphenyltetrazolium chloride staining was used to measure the infarct area, neurological deficit was scored, hematoxylin and eosin staining was used to examine pathological changes and TUNEL staining was used to quantify apoptosis. Immunofluorescence staining and reverse transcription­quantitative PCR were used to determine CD31 and VEGF protein and mRNA expressions, respectively, and western blot analysis was used out to measure the protein expression levels of Wnt3a, GSK­3ß and phosphorylated (p)­GSK­3ß. Compared with rats in the Control and Sham groups, in IR model rats the nerve fibers were slightly necrotic and swollen and the number of nerve cells was reduced. Following EPC treatment, the brain tissue exhibited mild liquefaction and degeneration in the small focus area with mild edema in the stroma. The numbers of nerve cells decreased, and the distribution of nerve cells was not very uniform; proliferation of glial cells was observed. Following treatment with exosomes, the distribution of nerve cells was more uniform with less degeneration and necrosis; the proliferation of glial cells was remarkable. Compared with the Control group, the infarct size, neurological defect score, percentage of apoptotic cells, expression of CD31, VEGF, Wnt3a, and p­GSK­3ß were significantly higher in the IR model (P<0.05). After EPC and exosome treatments, the infarct size, neurological defect score, percentage of apoptotic cells, expression of Wnt3a, and p­GSK­3ß were significantly reduced (P<0.05), whereas the mRNA and protein expression levels of CD31 and VEGF were significantly increased (P<0.05). Results from the present study demonstrated that EPC­derived exosomes may alleviate ischemic injury by inhibiting apoptosis and promoting angiogenesis. These findings suggested that exosomes may have a protective role for nerve cells and may be a potentially effective option for treating stroke. However, human clinical studies are needed to validate these findings from animals.

Bilateral cavernous sinus dural arteriovenous fistula with initial ocular symptom: A case report.

RATIONALE: Cavernous sinus dural arteriovenous fistula (CSDAVF) is a rare intracranial vascular malformation. Because of its complicated clinical manifestations, it is easy to miss or misdiagnose CSDAVF. PATIENT CONCERNS: A 42-year-old female had chief complaint that the right eyeball had conjunctival congestion for half a year. She was given levofloxacin eye drops to treat the right eye with anti-inflammatory treatment, but the symptoms did not improve. Cranial magnetic resonance and cerebrovascular imaging showed that the right lateral rectus muscle was slightly enlarged, the right eyeball was prominent, but there was no abnormality in the brain. DIAGNOSES: Based on clinical and imaging examinations and digital subtraction angiography (DSA), she was diagnosed as low-flow CSDAVF. INTERVENTIONS: The patient received interventional embolization with transvenous combined arterial approach using coils and Onyx liquid glue. OUTCOMES: The patient's exophthalmos and congestion symptoms were improved. CONCLUSION: DAS is the gold standard for the diagnose of CSDAVF. Intravascular embolization interventional therapy is an effective treatment for CSDAVF.

Regulatory mechanism of MiR-21 in formation and rupture of intracranial aneurysm through JNK signaling pathway-mediated inflammatory response.

OBJECTIVE: To investigate the regulatory mechanism of micro ribonucleic acid (miR)-21 in the formation and rupture of intracranial aneurysm through the c-Jun N-terminal kinase (JNK) signaling pathway-mediated inflammatory response. METHODS: In the present study, the mice with miR-21 expression deficiency and over-expression in our laboratory were enrolled as the experimental group, while wild-type healthy mice were used as the control group. The mouse model of intracranial aneurysm was established by bilateral carotid artery ligation. The differences in the levels of key genes in the JNK signaling pathway (JNK1 and JNK2) were detected by fluorescence quantitative polymerase chain reaction (qPCR) and western blotting. At the same time, the changes in transcription and translation levels of inflammatory factors, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), in both groups were measured. After the mice were executed by an overdose of anesthesia, the morphology of the aneurysm in different objects was observed by Verhoeff-Van Gieson (EVG) staining and the expressions of TNF-α, JNK1, and JNK2 were determined by immunohistochemistry. RESULTS: Compared with healthy mice, levels of JNK1 and JNK2 in mice with miR-21 deficiency were significantly decreased (P < 0.05) with a significant reduction of inflammatory factors IL-6 and TNF-α (P < 0.05). Compared with healthy mice, levels of JNK1 and JNK2 in mice with miR-21 over-expression were significantly increased (P < 0.05) with significant growing levels of inflammatory factors IL-6 and TNF-α (P < 0.05). The results of EVG staining revealed that the intracranial aneurysm was smaller in mice with miR-21 deficiency [(0.3 ± 0.12) cm] and larger in mice with miR-21 over-expression [(0.8 ± 0.25) cm] and there was a significant difference (P < 0.05). Moreover, the results of immunohistochemistry showed that the expression of TNF-α in intracranial aneurysm was obviously lower in mice with miR-21 deficiency than that in mice with miR-21 over-expression. CONCLUSION: MiR-21 can promote the production of inflammation-related factors through the JNK signaling pathway, leading to the formation and rupture of an intracranial aneurysm.

Mesenchymal stem cells regulate the proliferation and differentiation of neural stem cells through Notch signaling.

The effects of mesenchymal stem cells (MSCs) on proliferation and cell fate determination of neural stem cells (NSCs) have been investigated. NSCs were co-cultured with MSCs or NIH3T3 cells using an in vitro transwell system. After 4 days, immunofluorescence staining showed that the number of cells positive for the cell proliferation antigen, ki-67, in neurospheres in MSCs was greater than in NIH3T3 cells. In some experiments, the top-layers of MSCs and NIH3T3 cells were removed to induce NSCs differentiation. Seven days after initiating differentiation, the levels of the neuronal marker, NSE, were higher in NSCs in MSCs co-culture group, and those of glial fibrillary acidic protein (GFAP) were lower, compared with NIH3T3 cells co-culture group. These were confirmed by immunofluorescence. The role of the Notch signaling pathway analyzed with the specific inhibitor, DAPT, and by examining the expression of Notch-related genes using RT-PCR showed that after co-culturing with MSCs for 24h, NSCs expressed much higher levels of ki-67, Notch1, and Hes1 than did NSCs co-cultured with NIH3T3 cells. Treatment with DAPT decreased ki-67, Notch1 and Hes1 expression in NCSs, and increased Mash1 expression. The data indicate that the interactions between MSCs and NSCs promote NSCs proliferation and are involved in specifying neuronal fate, mediated in part by Notch signaling.

Apc gene suppresses intracranial aneurysm formation and rupture through inhibiting the NF-κB signaling pathway mediated inflammatory response.

Background: Intracranial aneurysm (IA) is a critical acquired cerebrovascular disease that may cause subarachnoid hemorrhage, and nuclear factor-κB (NF-κB)-mediated inflammation is involved in the pathogenesis of IA. Adenomatous polyposis coli (Apc) gene is a tumor suppressor gene associated with both familial and sporadic cancer. Herein, the purpose of our study is to validate effect of Apc gene on IA formation and rupture by regulating the NF-κB signaling pathway mediated inflammatory response. Methods: We collected IA specimens (from incarceration of IA) and normal cerebral arteries (from surgery of traumatic brain injury) to examine expression of Apc and the NF-κB signaling pathway related factors (NF-κB p65 and IκBα). ELISA was used to determine levels of monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß (IL-1ß), and IL-6. IA model was established in rats, and Apc-siRNA was treated to verify effect of Apc on IA formation and rupture. Next, regulation of Apc on the NF-κB signaling pathway was investigated. Results: Reduced expression of Apc and IκBα, and increased expression of NF-κB p65 were found in IA tissues. MCP-1, TNF-α, IL-1ß, and IL-6 exhibited higher levels in unruptured and ruptured IA, which suggested facilitated inflammatory responses. In addition, the IA rats injected with Apc-siRNA showed further enhanced activation of NF-κB signaling pathway, and up-regulated levels of MCP-1, TNF-α, IL-1ß, IL-6, MMP-2, and MMP-9 as well as extent of p65 phosphorylation in IA. Conclusion: Above all, Apc has the potential role to attenuate IA formation and rupture by inhibiting inflammatory response through repressing the activation of the NF-κB signaling pathway.

Lactoferrin- and RGD-comodified, temozolomide and vincristine-coloaded nanostructured lipid carriers for gliomatosis cerebri combination therapy.

PURPOSE: Glioblastoma multiforme (GBM) is the most common malignant brain tumor originating in the central nervous system in adults. Based on nanotechnology such as liposomes, polymeric nanoparticles, and lipid nanoparticles, recent research efforts have been aimed to target drugs to the brain. METHODS: In this study, lactoferrin- and arginine-glycine-aspartic acid (RGD) dual- ligand-comodified, temozolomide and vincristine-coloaded nanostructured lipid carriers (L/RT/V-NLCs) were introduced for GBM combination therapy. The physicochemical properties of L/R-T/V-NLCs such as particle size, zeta potential, and encapsulated efficiency are measured. The drug release profile, cellular uptake, cytotoxicity, tissue distribution, and antitumor activity of L/R-T/V-NLCs are further investigated in vitro and in vivo. RESULTS: L/R-T/V-NLCs were stable with nanosize and high drug encapsulation efficiency. L/R-T/V-NLCs exhibited sustained-release behavior, high cellular uptake, high cytotoxicity and synergy effects, increased drug accumulation in the tumor tissue, and obvious tumor inhibition efficiency with low systemic toxicity. CONCLUSION: L/R-T/V-NLCs could be a promising drug delivery system for glioblastoma chemotherapy.

HP1α is highly expressed in glioma cells and facilitates cell proliferation and survival.

Epigenetic alteration plays critical roles in gliomagenesis by regulating gene expression through modifications of Histones and DNA. Trimethylation of H3K9, an essential repressed transcription mark, and one of its methyltransferase, SUV39H1, are implicated in glioma pathogenesis and progression. We find that the protein level of HP1α, a reader of H3K9me3 is elevated in GOS3 and 1321N1 glioma cell lines. H3K9me3 and SUV39H1 level are also upregulated. Depletion of HP1α and SUV39H1 weakens GOS3 and 1321N1 cell proliferation capacity and results in apoptosis of cells. Furthermore, we find that HP1α and H3K9me3 are enriched in the FAS and PUMA promoters, which suggests that upregulated HP1α and H3K9me3 prevent apoptosis by suppressing apoptotic activators. These data indicates that up-regulated HP1α, SUV39H1, and H3K9me3 in glioma cells are functionally associated with glioma pathogenesis and progression, and may serve as novel biomarkers for future diagnostic and therapeutic targeting of brain tumors.

Nanostructured lipid carriers based temozolomide and gene co-encapsulated nanomedicine for gliomatosis cerebri combination therapy.

BACKGROUND: Co-delivery of gene and anticancer drug into the same cancer cells or tissues by multifunctional nanocarriers may provide a new paradigm in cancer treatment. In this study, nanostructured lipid carriers (NLCs) were constructed as multifunctional nanomedicine for co-delivery of enhanced green fluorescence protein plasmid (DNA) and temozolomide (TMZ). METHODS: TMZ- and DNA-loaded NLCs (TMZ/DNA-NLCs) were prepared. Their particle size, zeta potential, gene-loading capacity (GL) and drug encapsulation efficiency (EE) were evaluated. In vitro cytotoxicity study TMZ/DNA-NLCs was tested in U87 malignant glioma cells (U87 MG cells). In vivo gene transfection and anti-tumor efficacy of the carriers were evaluated on mice bearing malignant glioma model. RESULTS: The optimum TMZ/DNA-NLCs formulations with the particle size of 179 nm and with a +23 mV surface charge; got 91% of GL and 83% of EE. The growth of U87 MG cells in vitro was obviously inhibited. TMZ/DNA-NLCs also displayed the highest gene transfection efficiency and the best antitumor activity than other formulations in vivo. CONCLUSION: The results demonstrated that TMZ/DNA-NLCs were efficient in selective delivery to malignant glioma cells. Also TMZ/DNA-NLCs transfer both drug and gene to the gliomatosis cerebri, enhance the antitumor capacity and gene transfection efficacy. Thus, TMZ/DNA-NLCs could prove to be a superior co-delivery nanomedicine to achieve therapeutic efficacy and this report could be a new promising strategy for treatment in malignant gliomatosis cerebri.

Nanostructured lipid carriers, solid lipid nanoparticles, and polymeric nanoparticles: which kind of drug delivery system is better for glioblastoma chemotherapy?

CONTEXT: Glioblastoma is a malignant brain tumor originating in the central nervous system. Successfully therapy of this disease required the efficient delivery of therapeutic agents to the tumor cells and tissues. Delivery of anticancer drugs using novel nanocarriers is promising in glioma treatment. OBJECTIVE: Polymeric nanoparticles (PNPs), solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs) were constructed for the delivery of temozolomide (TMZ). The anti-tumor effects of the three kinds of nanocarriers were compared to provide the optimum choice for gliomatosis cerebri treatment. METHODS: TMZ-loaded PNPs (T-PNPs), SLNs (T-SLNs), and NLCs (T-NLCs) were formulated. Their particle size, zeta potential, drug encapsulation efficiency (EE), and drug loading (DL) capacity were evaluated. Anti-tumor efficacies of the three kinds of nanocarriers were evaluated on U87 malignant glioma cells (U87 MG cells) and mice-bearing malignant glioma model. RESULTS: T-NLCs displayed the best anti-tumor activity than other formulations in vivo and in vitro. The most significantly glioma inhibition was observed on NLCs formulations than PNPs and SLNs. CONCLUSION: This work demonstrates that NLCs can deliver TMZ into U87MG cells more efficiently, with higher inhibition efficacy than PNPs and SLNs. T-NLCs could be an excellent drug delivery system for glioblastoma chemotherapy.

Differentiation of human bone marrow stromal cells into neural-like cells induced by sodium ferulate in vitro.

Human marrow stromal cells (hMSCs) are multipotential stem cells, capable of differentiating into bone, cartilage, fat and muscle. Several recent reports demonstrated that hMSCs have been also differentiated into neural cells. However, only a few reported inducers are applicable for clinical use. This work is to explore the effects of sodium ferulate (SF) on differentiation of hMSCs into neural cells in vitro. We found that hMSCs could be induced to the cells with typical neural morphology when cultured with SF. The cells express neural proteins, such as nestin, neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP). About 30% of the hMSC-derived cells expressed nestin when cultured with SF for 3 h, but no expression was detected after 24 h. The percentages of positive cells for NSE or GFAP were about 67% and 39% separately at 6 h, and reached the plateau phage after treatment with SF for 3 days. The data suggest that SF can induce hMSCs to differentiate into neural-like cells in vitro.