miR-124 upregulates astrocytic glutamate transporter-1 via the Akt and mTOR signaling pathway post ischemic stroke.

High-concentration glutamic acid (Glu) induced by ischemic stroke can be inhibited by glutamate transporter-1 (GLT-1), which is the main mechanism for preventing excessive extracellular glutamate accumulation in the central nervous system. Upregulation of miR-124 could reduce the infarct area and promote the recovery of neurological function after ischemic stroke. A previous study investigated whether miR-124 could regulate GLT-1 expression in normal culture conditions. However, the role of miR-124 in the regulation of GLT-1 expression and further mechanisms after ischemic stroke remain unclear. In this study, the effects of miR-124 on GLT-1 expression in astrocytes after ischemic stroke were explored using an in vitro model of ischemic stroke (oxygen-glucose deprivation/reperfusion, OGD/reperfusion). The expression of GLT-1 was significantly decreased with lower expression of miR-124 in astrocytes injured by OGD/reperfusion. When miR-124 expression was improved, the expression of GLT-1 was notably increased in astrocytes injured by OGD/reperfusion. The results revealed that GLT-1 expression in astrocytes had a relationship with miR-124 after OGD/reperfusion. However, a direct interaction could not be confirmed with a luciferase reporter assay. Further results demonstrated that an inhibitor of Akt could decrease the increased protein expression of GLT-1 induced by miR-124 mimics, and an inhibitor of mTOR could increase the reduced protein expression of GLT-1 caused by a miR-124 inhibitor in astrocytes injured by different OGD/reperfusion conditions. These results indicated that miR-124 could regulate GLT-1 expression in astrocytes after OGD/reperfusion through the Akt and mTOR pathway.

Association between inflammatory cytokines and the risk of post-stroke depression, and the effect of depression on outcomes of patients with ischemic stroke in a 2-year prospective study.

The association between inflammatory cytokines and the risk of post-stroke depression (PSD) remains unclear. The aim of the present study was to investigate this association and the effect of PSD on the outcomes of ischemic stroke patients. A total of 355 patients who had experienced ischemic stroke participated in inflammatory cytokine detection by ELISA, in addition to depression, quality of life (QOL) and body performance testing. Cox regression was used to evaluate the associations between PSD risk, inflammatory cytokines and the outcomes of patients. Measurement data was evaluated using Student's t test, and counted data was measured by χ2 test. The incidence of PSD during the 2-year follow-up was 23.1%. The risk of PSD elevated with increased interleukin (IL)-6 expression levels [hazard ratio (HR)=3.18; 95% confidence interval (CI), 1.37-7.36] following the adjustment of confounders. However, no significant associations were identified between PSD and other inflammatory cytokines. QOL and body performance in the depressed group were significantly worse compared with those in the non-depressed group. The risk of stroke recurrence in patients with depression increased two-fold compared with patients without depression (HR=2.020; 95% CI, 1.123-3.635; Ptrend=0.019). No significant associations between PSD and the risk of mortality (HR=1.497; 95% CI, 0.547-4.098) were observed. In conclusion, depression is prevalent in patients following ischemic stroke. IL-6 is positively associated with the risk of PSD, and may predict its development in patients following ischemic stroke. PSD correlates with outcomes of patients, and the effective management of PSD may improve the prognosis of patients.

Curcumin induces G2/M arrest and triggers apoptosis via FoxO1 signaling in U87 human glioma cells.

It has previously been demonstrated that curcumin possesses an antitumor activity, which is associated with its ability to induce G2/M cell cycle arrest and apoptosis. However the detailed underlying mechanisms remain unclear. The present study aimed to investigate the efficacy and underlying mechanism of curcumin­induced cell cycle arrest and apoptosis in U87 human glioblastoma cells. By immunofluorescence staining, subcellular fractionation and western blotting, the present study demonstrated that curcumin was able to induce G2/M cell cycle arrest and apoptosis by increasing the expression levels of cyclin G2, cleaved caspase­3 and Fas ligand (FasL), and decreasing the expression of cyclin­dependent kinase 1 (CDK1). In addition, increased expression of forkhead box protein O1 (FoxO1) and decreased expression of phosphorylated (p)­FoxO1 were detected in the curcumin­treated U87 cells. Curcumin was also able to induce the translocation of FoxO1 from the cytoplasm to the nucleus. Furthermore, following knockdown of FoxO1 expression in curcumin­treated U87 cells using FoxO1 small interfering RNA, the expression levels of cyclin G2, cleaved caspase­3 and FasL were inhibited; however, the expression levels of CDK1 were not markedly altered. Notably, following knockdown of CDK1 expression under normal conditions, the total expression of FoxO1 was not affected; however, p­FoxO1 expression was decreased and FoxO1 nuclear expression was increased. Furthermore, curcumin­induced G2/M cell cycle arrest and apoptosis could be attenuated by FoxO1 knockdown. These results indicated that curcumin may induce G2/M cell cycle arrest and apoptosis in U87 cells by increasing FoxO1 expression. The present study identified a novel mechanism underlying the antitumor effects of curcumin, and may provide a theoretical basis for the application of curcumin in glioma treatment.

Relationship between inflammatory cytokines and risk of depression, and effect of depression on the prognosis of high grade glioma patients.

Depression is found to be associated with up-regulation of inflammatory cytokines. However, the relationship in high grade glioma (HGG) patients is still unclear. In this prospective study, a total 132 HGG patients participated in blood sample collection for inflammatory cytokines detection by ELISA, mental status, quality of life (QOL) and physical functional status testing. The association between inflammatory cytokines and depression risk was assessed using conditional logistic regression. The incidences of depressive symptoms and depression in high grade glioama patients were 45.5 and 25 % respectively during 12 months follow-up. We found the risk of depression was elevated with increased C-reactive protein (CRP) and interleukin-6 (IL-6) in high grade glioma patients after adjustment of confounders. The serum levels of CRP and IL-6 in patients with transient depression and depression were higher than those without depressive symptoms. In addition, depression had significant effects on the survival, QOL and physical functional status of patients. Depression is prevalent among patients with HGG. The present study suggests that serum CRP and IL-6 may serve as a depression marker for HGG patients. The survival and quality of life of HGG patients may be improved by an effective management for depression.

Curcumin enhances the radiosensitivity of U87 cells by inducing DUSP-2 up-regulation.

OBJECTIVE: Glioblastoma multiforme (GBM), an aggressive primary brain tumor, is radioresistant and recurs despite aggressive surgery, chemotherapy, and radiotherapy. Curcumin as a potential radiosensitizer has received extensive attention in cancer treatment. To explore an effectiveness of this radiosensitizer for GBM treatment, we evaluated the radiosensitizing effect of curcumin and investigated its potential molecular mechanisms in the human glioma cell line U87. METHODS: The cytotoxic effects of curcumin on U87 cells were evaluated using the Cell Counting Kit-8 assay, and the radiosensitivity of U87 cells treated with curcumin was accessed by colony information assay. The effects of curcumin on cell proliferation and cell cycle regulation were determined using the 5-ethynyl-2-deoxyuridine incorporation assay and flow cytometry, respectively. Western blotting was applied to determine the effects of curcumin on protein expression of dual-specificity phosphatase-2 (DUSP-2), extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) as well as phosphorylated ERK and JNK. RESULTS: Curcumin significantly inhibited the proliferation of U87 cells in a dose-and time-dependent manner. Curcumin treatment at the concentrations of 5 µM and 10 M could significantly reduce the clonogenic activity and enhance the radiosensitivity of U87 cells with sensitive enhancement ratios (SERs) of 1.71 and 4.65, respectively. Curcumin resulted in G2/M cell cycle arrest in U87 cells, which were radiosensitive. Pre-treatment of U87-MG cells with 5 µM curcumin enhanced radiation-induced cell proliferation inhibition and apoptosis. Furthermore, we observed that curcumin increased DUSP-2 protein expression and decreased the phosphorylation of ERK and JNK. CONCLUSION: Our results suggest that low-dose curcumin may enhance the radiosensitivity of human glioma U87 cells in vitro by inducing G2/M cell cycle arrest through up-regulation of DUSP-2 expression and inhibition of ERK and JNK phosphorylation.

Metabolic syndrome factors and risk of postoperative depression in high-grade glioma patients in a 1.5-year prospective study.

To date, the relationship between metabolic syndrome factors and the risk of glioma-related depression is still unclear, and no study investigates this relationship. Our aim was to investigate the relationship between metabolic syndrome factors and the risk of postoperative depression in high-grade patients. A total of 386 high-grade glioma patients participated in blood sample collection for metabolic syndrome factors analysis and the hospital anxiety and depression scale testing. The association between metabolic syndrome factors and the risk of postoperative depression was assessed using Cox regression proportional hazards models, and Student's t tests were used to evaluate the differences in demographic variables and clinical characteristics in subgroups. The incidence of postoperative depression in our 1.5-year follow-up was 30.5%. We found the risk of postoperative depression was elevated with increased blood glucose level [hazard ratios (HR) 2.277, 95% confidence interval (CI) 1.201-4.320, top vs. bottom quartile]. The hazard ratio was increased for z-scores of blood glucose (HR 1.672 per unit standard deviation, 95% CI 1.311-2.133] and of the combined metabolic syndrome score (HR 1.080, 95% CI 1.000-1.167). In addition, risk of postoperative depression risk was increased in high-grade glioma patients with high blood glucose levels (≥6.0 mmol/l) (HR 2.084, 95% CI 1.235-3.515). However, we did not find significant associations between postoperative depression and other metabolic syndrome factors, including body mass index, systolic blood pressure, diastolic blood pressure, cholesterol, and triglycerides. Depression is prevalent among patients with high-grade glioma after operation. Blood glucose level is positively associated with the risk of postoperative depression, and might be involved in the etiology of postoperative depression, and may predict its development in high-grade glioma patients.

Suppressing the malignant phenotypes of glioma cells by lentiviral delivery of small hairpin RNA targeting hypoxia-inducible factor-1α.

Hypoxic microenvironment of solid tumors is known to shape malignant phenotypes of cancer cells through the dimeric transcription factor hypoxia-inducible factor (HIF)-1. In the present study, the therapeutic effect of targeting α subunit of HIF-1 in glioma cells via lentiviral delivery of small hairpin RNA (shRNA) was evaluated. Data from quantitative real-time PCR and immunohistochemistry demonstrated that HIF-1α was progressively upregulated during the development of gliomas. Lentiviral shRNA targeting HIF-1α led to substantial loss of cell viability, G0/G1-phase cell cycle arrest, apoptosis, and impairment of cell motility and invasiveness in human glioma U87MG cells. Xenograft experiments in nude mice further showed that HIF-1α-shRNA inhibited tumor growth and caused persistent repression of HIF-1α and its target genes, including VEGF, GLUT1 and MMP2, up to 25 days post-inoculation. Taken together, lentiviral delivery of shRNA is a promising therapeutic approach for targeting HIF-1α in glioma.

AntagomiR-27a targets FOXO3a in glioblastoma and suppresses U87 cell growth in vitro and in vivo.

OBJECTIVE: To study the effect of the antagomiR-27a inhibitor on glioblastoma cells. METHODS: The miR- 27a expression level in specimens of human glioblastoma and normal human brain tissues excised during decompression for traumatic brain injury was assessed using qRT-PCR; The predicted target gene of miR-27a was screened out through bioinformatics databases, and the predicted gene was verified using genetic report assays; the effect of antagomiR-27a on the invasion and proliferation of glioma cells was analyzed using MTT assays and 5-ethynyl-2'-deoxyuridine (EdU) labeling. A xenograft glioblastoma model in BALB-c nude mice was established to detect the effect of antagomiR-27a on tumour growth. RESULTS: qRT-PCR results showed that miR-27a significantly increased in specimens from glioblastoma comparing with normal human brain tissues. Th miR-27a inhibitor significantly suppressed invasion and proliferation of glioblastoma cells. FOXO3a was verified as a new target of miR-27a by Western blotting and reporter analyzes. Tumor growth in vivo was suppressed by administration of the miR-27a inhibitor. CONCLUSION: MiR-27a may be up-regulated in human glioblastoma, and antagomiR-27a could inhibit the proliferation and invasion ability of glioblastoma cells.

[Pathologic and immunohistochemical study on lethal primary brain stem injury].

OBJECTIVE: To study the histopathologic changes of primary brain stem injury and to investigate their significance in the diagnosis of primary brain stem injury. METHODS: Sixty-five autopsy cases died of primary brain stem injury and other diseases were enrolled into this study. The cases were subdivided into brain stem injury group (n = 25) and control group (including 20 cases died of cardiovascular disease and 20 cases died of non-cardiovascular diseases). The brain stem tissue sections were stained with hematoxylin-eosin and silver impregnation techniques. Immunohisto chemical study for glial fibrillary acidic protein, neurofilament, amyloid-beta and myelin basic protein was carried out. The widest cross diameters of 10 axons highlighted by immunostaining were measured in each low power field (x 100) through light miscroscopy in all the cases studied. RESULTS: In comparing with that of the control group, there were differences in the degree of contusion lesion, reactive astrocytosis, edema and pathologic changes of neuronal cells present in the brain stem injury group and was statistically significant (P < 0.05). The axons locating in the brain stem injury group showed a distinctive histology by the appearance of significantly larger diameters (P < 0.05). CONCLUSIONS: Primary brain stem injury demonstrates certain distinctive histopathologic changes and measurement of axonal diameters provides an additional quantitative index useful in autopsy diagnosis.