Ikuo Hashimoto

Histone deacetylase inhibitors such as sodium butyrate and trichostatin A induce apoptosis through an increase of the bcl-2-related protein Bad.

The effects of sodium butyrate (SB) and trichostatin A (TSA) on cell proliferation and apoptosis against human glioma T98G, U251MG, and U87MG cells were investigated. Upon exposure to either SB or TSA, cell proliferation was reduced, and apoptosis detected by DNA fragmentation analysis and the cleavage of CPP32 was induced. Previously, we reported that SB increased the expression levels of p21 (WAF-1) and inhibited G1-S transition of the cell cycle. In this study, we showed that TSA also increased p21 expression, suggesting that histone deacetylase (HDAC) inhibitors may up-regulate p21 protein in common and thus arrest proliferation in the G1 phase of the cell cycle. To further determine the underlying molecular mechanisms of apoptosis with either SB or TSA treatment, we studied the expression levels of apoptosisrelated proteins in human glioma cells. SB increased the expression of the Bad protein, although the expression of Bcl-2, Bcl-xL, Bax, and Fas was not changed by the addition of SB. TSA treatment also up-regulated the expression of Bad protein. The results suggest that HDAC inhibitors such as SB and TSA induce apoptosis through an increase in Bad protein in human glioma cells in vitro.

Histone deacetylase inhibitor, FK228, induces apoptosis and suppresses cell proliferation of human glioblastoma cells in vitro and in vivo

We investigated the effects of FK228 on cell proliferation and apoptosis against human glioblastoma (GM) T98G, U251MG, and U87MG cells. Upon exposure to FK228, cell proliferation was inhibited, and apoptosis detected by the cleavage of CPP32 was induced. FK228 increased the expression levels of p21 (WAF-1) and of pro-apoptotic Bad protein in all GM cells. Furthermore, FK228 treatment also reduced the anti-apoptotic protein Bcl-xL in all GM cells and anti-apoptotic Bcl-2 in U87MG cells, thereby shifting the cellular equilibrium from life to death. An increased accumulation of histone H4 was detected in the p21 (WAF-1) promoter and the structural gene (exon 2) and the Bad structural gene (exon 2 and 3) upon treatment with FK228, as assessed by chromatin immunoprecipitation (ChIP) assay. Thus, the results indicated that an increased expression of p21 (WAF1) and Bad due to FK228 is regulated, at least in part, by the degree of acetylation of the gene-associated histone. We also found that FK228 inhibits cellular invasiveness and decreases MMP-2 activity. In addition, the growth of transplanted human GM m-3 cells into the subcutaneous tissue of hereditary athymic mice was significantly inhibited, and apoptosis was induced with FK228 treatment. The results suggested that FK228 might be useful in the treatment of human GM, although further studies will be needed.

Histone deacetylase inhibitors such as sodium butyrate and trichostatin A inhibit vascular endothelial growth factor (VEGF) secretion from human glioblastoma cells

We investigated the effects of histone deacetylase (HDAC) inhibitors such as sodium butyrate (SB) and trichostatin A (TSA) on the expression of vascular endothelial growth factor (VEGF) by human glioblastoma T98G, U251MG, and U87MG cells. The glioblastoma cells secreted three VEGF isoforms, VEGF (189), (165), and (121), although the expression levels of VEGF differed between the cell types. Treatment with either 5mM SB or 100ng/ml TSA reduced VEGF secretion in conditioned media and reduced VEGF mRNA expression. We also studied the expression of VEGF-B,-C, and-D mRNA in human glioblastoma cells and their modulation by HDAC inhibitors. The PCR products of VEGF-B (357 bp), VEGF-C (501 bp), and VEGF-D (484 bp) were amplified in all glioblastoma cells examined. Treatment with SB reduced the expression of VEGF-D mRNA in U251MG cells and the expression of VEGF-B mRNA in U87MG cells. TSA treatment reduced the expression of VEGF-D in U251MG cells. These results suggest that HDAC inhibitors reduce VEGF secretion and modulate the expression of the other VEGF family members, and therefore may inhibit angiogenesis in glioblastoma tissues.

Transient ischemic attacks caused by unruptured intracranial aneurysm

A case is reported of a 56-year-old man in whom an unruptured aneurysm of the left middle cerebral artery was the source of emboli resulting in transient ischemic attacks (TIAs). The potential relationship between TIAs and an unruptured aneurysm is discussed, and the literature is reviewed.

Quantitative imaging of spontaneous neuromagnetic activity for assessing cerebral ischemia using sLORETA-qm.

To image cerebral neural activity in ischemic areas, we proposed a novel technique to analyze spontaneous neuromagnetic fields based on standardized low-resolution brain electromagnetic tomography modified for a quantifiable method (sLORETA-qm). Using a 160-channel whole-head-type magnetoencephalographic system, cerebral magnetic fields were obtained pre- and postoperatively from 5 patients with unilateral internal carotid artery occlusive disease and 16 age-matched healthy volunteers. For quantitative imaging, voxel-based time-averaged intensities of slow waves in 4 frequency bands (0.3-2 Hz, 2-4 Hz, 4-6 Hz and 6-8 Hz) were obtained by the proposed technique based on sLORETA-qm. Positron emission tomography with (15)O gas inhalation ((15)O-PET) was also performed in these patients to evaluate cerebral blood flow and metabolism. In all 5 patients, slow waves in every frequency band were distributed in the area of cerebrovascular insufficiency, as confirmed by (15)O-PET preoperatively. In 4 patients, slow-wave intensities in theta bands (4-6 Hz, 6-8 Hz) decreased postoperatively along with improvements in cerebral blood flow and metabolism, whereas delta bands (0.3-2 Hz, 2-4 Hz) showed no significant differences between pre- and postoperatively. One patient with deterioration of cerebral infarction after surgery showed marked increases in slow-wave intensities in delta bands (0.3-2 Hz, 2-4 Hz) postoperatively, with distribution close to the infarct region. The proposed quantitative imaging of spontaneous neuromagnetic fields enabled clear visualization and alternations of cerebral neural conditions in the ischemic area. This technique may offer a novel, non-invasive method for identifying cerebral ischemia, although further studies in a larger number of patients are warranted.

Prediction of seizure outcome following epilepsy surgery: Asymmetry of thalamic glucose metabolism and cerebral neural activity in temporal lobe epilepsy §

OBJECTIVEnThe objective of this retrospective study is to analyze whether preoperative functional imaging studies using FDG-PET and MEG enable prediction of postoperative seizure outcomes.nnnMETHODSnThirty-six patients with intractable temporal lobe epilepsy were studied. Asymmetry index of tCMRgluc (PET-AI) and the equivalent current dipole intensity of first response of SEF (SEF-AI) were determined preoperatively using (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) and magnetoencephalography (MEG), respectively. Seizure outcomes were evaluated according to the classification proposed by the International League Against Epilepsy (ILAE) at least 24 months after resection of epileptic focuses. Twelve healthy volunteers were included in this study to determine the normal value.nnnRESULTSnQuantitative analysis revealed mean PET-AI in the patients was 5.4+/-5.2% (significantly different from normal controls); mean SEF-AI was 25.2+/-20.6% (not significantly different). PET-AI was positive (indicative of epileptic focus) in 29 of 36 patients (80.6%), while SEF-AI was positive in 17 of 36 patients (47.2%). Although no significant correlation between PET-AI and SEF-AI was noted (r=0.43), concordant asymmetry in both PET-AI and SEF-AI was significantly associated with better seizure outcome than discordant or paradoxical asymmetry of both factors (p<0.01).nnnCONCLUSIONSnThe results suggest that quantitative analysis of tCMRgluc with SEF may be helpful in characterizing the preoperative epileptogenic condition and predicting postoperative seizure outcome in patients with temporal lobe epilepsy, although a constellation of developmental brain abnormalities and environmental factors that together produce epilepsy need to be further explored.

Completely thrombosed giant aneurysm of the angular artery

An unusual case of a completely thrombosed giant aneurysm arising from the angular artery is reported. A 69-year-old women developed a subarachnoid hemorrhage with a large intracranial hematoma. Computed tomography scans and cerebral angiography could not detect the aneurysm. The rarity of aneurysms in this position is stressed and the difficulty of diagnosis in this case is discussed.

Adult classical glioblastoma with a BRAF V600E mutation

The B-Raf proto-oncogene serine/threonine kinase (B-Raf) is a member of the Raf kinase family. The BRAF V600E mutation occurs frequently in certain brain tumors such as pleomorphic xanthoastrocytoma, ganglioglioma, and pilocytic astrocytoma, and less frequently in epithelioid and giant cell glioblastoma. BRAF V600E mutation in these cases has been canonically detected using Sanger sequencing or immunohistochemistry but not with next-generation sequencing (NGS). Moreover, to our knowledge, there is no detailed report of the BRAF V600E mutation in an adult glioblastoma with classical histologic features (c-GBM). Therefore, we performed NGS analysis to determine the mutational status of BRAF of 13 glioblastomas (GBMs) (11 primary and 2 secondary cases) and detected one tumor harboring the BRAF V600E mutation. We report here the detection of the BRAF V600E mutation in a patient with c-GBM and describe the patient’s clinical course as well as the results of histopathological analysis.

Reversible Splenial Lesion in Postpartum Cerebral Angiopathy: A Case Report

Reversible lesions on magnetic resonance imaging that transiently restrict diffusion in the splenium of the corpus callosum (SCC) without any other accompanying lesions have been reported in various clinical conditions. We offer the first report of postpartum cerebral angiopathy with reversible SCC lesions.

Recovery of spontaneous neuromagnetic activity after extracranial–intracranial bypass in a patient with middle cerebral artery occlusion

Patient and MethodsCerebral blood flow and neuromagnetic activity were measured using 123I-iodoamphetamine-single photon emission computed tomography (IMP-SPECT) and magnetoencephalography (MEG), before and after extracranial–intracranial (EC–IC) bypass surgery in a 55-year-old woman with unilateral middle cerebral artery occlusion that occurred with intraventricular haemorrhage. Frequency analysis of slow waves measured on MEG was performed using an adaptive beam-former method.Results and DiscussionDistribution of δ waves was observed pre-operatively corresponding to areas of cerebral hypo-perfusion as confirmed by IMP-SPECT but disappeared post-operatively with improvements in cerebral blood flow. Imaging of slow-wave distributions with MEG may represent a new technique for identifying cerebral ischaemia.