Clinical and angiographic features and stroke types in adult moyamoya disease.

BACKGROUND AND PURPOSE: This study was conducted to elucidate the association between clinical and angiographic characteristics and stroke types in adult Moyamoya disease that has been rarely evaluated. MATERIALS AND METHODS: We analyzed the clinical and radiologic data obtained from a retrospective adult Moyamoya disease cohort with acute strokes, which were classified into 7 categories: large-artery infarct, hemodynamic infarct, perforator infarct, deep intracerebral hemorrhage, lobar intracerebral hemorrhage, intraventricular hemorrhage, and SAH. With conventional angiography, which was performed in the hemispheres with acute strokes, the Suzuki angiographic stage, intracranial aneurysm, major artery occlusion, and collateral vessel development were confirmed within 1 month of stroke onset. RESULTS: This study included 79 patients with acute ischemic stroke and 96 patients with acute hemorrhagic stroke. The angiographic stage had a strong tendency to be more advanced in the hemorrhagic than the ischemic patients (P = .061). Intracranial aneurysms were more frequently found in the hemorrhagic than ischemic or control hemispheres (P = .002). Occlusions of the anterior cerebral artery and development of fetal-type posterior cerebral artery were more frequently observed in the hemorrhagic than the ischemic (P = .001 and .01, respectively) or control hemispheres (P = .011 and .013, respectively). MCA occlusion (P = .039) and collateral flow development, including the ethmoidal Moyamoya vessels (P = .036) and transdural anastomosis of the external carotid artery (P = .022), occurred more often in the hemorrhagic than the ischemic hemispheres. Anterior cerebral artery occlusion occurred more frequently in patients with deep intracerebral hemorrhage or intraventricular hemorrhage than with lobar intracerebral hemorrhage (P = .009). CONCLUSIONS: In adult Moyamoya disease, major artery occlusion and collateral compensation occurred more often in the hemorrhagic than in the ischemic hemispheres. Thus, anterior cerebral artery occlusion with or without MCA occlusion and intracranial aneurysms may be the main contributing factors to hemorrhagic stroke in adult patients with Moyamoya disease.

Merlin facilitates ubiquitination and degradation of transactivation-responsive RNA-binding protein.

The Nf2 tumor suppressor codes for merlin, a protein whose function is largely unknown. We have previously demonstrated a novel interaction between merlin and TRBP, which inhibits the oncogenic activity of TRBP. In spite of the significance of their functional interaction, its molecular mechanism still remains to be elucidated. In this report, we investigated how merlin inhibits the oncogenic activity of TRBP in association with cell growth conditions. In the human embryonic kidney 293 cell line, the level of endogenous merlin increased, whereas that of endogenous TRBP significantly decreased along with the increase in cell confluence. We demonstrated that the carboxyl-terminal region of TRBP was responsible for this phenomenon using stable cell lines expressing deletion mutants of TRBP. The overexpression of merlin decreased the protein level of TRBP, and the ubiquitin-like subdomain of merlin's FERM domain was important for this activity. We also demonstrated that TRBP is ubiquitinylated and the ubiquitinylated forms of TRBP are accumulated by ectopically expressed merlin or cell confluence in the presence of MG132, a proteasome inhibitor. Furthermore, we showed that the regulation of TRBP in response to cell confluence was abolished upon knockdown of merlin expression by specific small interfering RNA. Finally, we showed that ectopically expressed merlin restored cell-cell contact inhibition in cells stably expressing TRBP but not in TRBPDeltac. These results suggest that merlin is involved in the regulation of TRBP protein level by facilitating its ubiquitination in response to such cues as cell-cell contacts.

The induction of BDNF and c-fos mRNA in the hippocampal formation after febrile seizures.

In this study we investigated the expression of brain-derived neurotrophic factor (BDNF) and c-fos mRNA in the hippocampal formation after febrile seizures (FSs) with in situ hybridization histochemistry using riboprobes. The induction of BDNF mRNA was firstly observed in the dentate gyrus at 30 min after FSs. The expression in the dentate gyrus peaked at 3 h and returned to basal level at 24 h. It was also observed in the CA3 of hippocampus from 2 to 3 h. The induction of c-fos mRNA was observed in the dentate gyrus at 30 min and 1 h. These observations suggest that BDNF and c-fos are the genes whose expression can be altered by FSs and might be related to pathologic alterations after FSs.

Effect of bradykinin on cultured bovine corneal endothelial cells.

PURPOSE: To clarify the effect of bradykinin on cytosolic free calcium mobilization and cell proliferation in cultured bovine corneal endothelial cells (BCEC). METHODS: The cytosolic free calcium concentration (Ca2+]i) was measured with the InCa(TM) Imaging System after the treatment of bradykinin (10(-11) to 10(-7) M) alone or with the pretreatments of EGTA, bradykinin receptor (Bk1 and Bk2) antagonists and an inhibition of phospholipase C (U-73122). Also, the effect of bradykinin on cell proliferation in BCEC was evaluated using cell counts. RESULTS: In BCEC, [Ca2+]i in the resting state was 87 +/- 9 nM. Bradykinin induced an increment of [Ca2+]i in a concentration-dependent manner and its 50% effective concentration was approximately 5 x 10(-11) M. A [Ca2+]i increment at 10(-8) M bradykinin was inhibited with the pretreatment of EGTA, an extracellular calcium chelator. U-73122 (5 x 10(-6) M) attenuated the bradykinin-induced [Ca2+]i increment. The pretreatment of HOE-140 (Bk2 antagonist) almost attenuated the bradykinin (10(-8) M)-induced [Ca2+]i increase, but des-Arg9-[Leu(8)]-bradykinin (Bk1 antagonist) did not suppress it. To investigate the physiological effect of bradykinin, the effect of bradykinin on cell proliferation was studied. 10(-8) M of bradykinin produced a significant increase in cell numbers. This mitogenic effect of bradykinin was inhibited by the Bk2 antagonist. CONCLUSIONS: Bradykinin-induced stimulation of the signal transduction pathway in BCEC is coupled with the Bk2 type receptor. Furthermore, bradykinin produces the mitogenic effect in BCEC.

Cloning and characterization of the 5'-flanking region for the mouse phospholipase C-delta1 gene.

To date, little is known about the molecular mechanisms controlling the regulation of phospholipase C-delta1 (PLC-delta1) gene expression. To understand the mechanisms responsible for the regulation of PLC-delta1 gene expression, the 5'-flanking region of the mouse PLC-delta1 gene was isolated from a mouse genomic DNA library. Primer extension analysis revealed that there is a single transcriptional start site located at 127 bases upstream from the translation start codon in the mouse PLC-delta1 gene. DNA sequence analysis showed that the sequence around the transcriptional start site is very GC-rich and has no TATA or CAAT boxes. Transient expression of a luciferase reporter gene under the control of serially deleted 5'-flanking sequences revealed that the 160-base-pair region from -622 to -462 upstream of the transcriptional start site includes a positive cis-acting element(s) for the efficient expression of the PLC-delta1 gene. Gel retardation analysis suggests that multiple transcription factors bind to separate sites on the promoter region. Based on these results, our study suggests that the minimal essential region located at -622 to +70 is fully sufficient to confer high-level transcriptional activity and contains high-affinity binding elements for multiple transcription factors.

Adenosine triphosphate-induced heterologous desensitization of endothelin-1- and glutamate-evoked calcium increases in cultured rat cortical astrocytes.

In rat cortical astrocytes, we investigated the occurrence of cross-talks between purinoceptor and endothelin (ET) receptor, or glutamate receptor. The treatments of adenosine triphosphate (ATP), ET-1, and glutamate induced the increase of intracellular calcium level in the astrocytes. In repetitive additions of ATP to astrocytes, the second application of ATP exhibited comparable amplitude of calcium response, but the stimulation with ATP completely blocked subsequent ET-1- or glutamate-evoked calcium responses showing complete heterologous desensitization. In contrast, ET-1 and glutamate failed to desensitize the response elicited by ATP. Preincubation with sphingosine, a protein kinase C (PKC) inhibitor, reversed the ATP-induced desensitization of ET-1- and glutamate-evoked calcium responses. Taken together, these results demonstrate the resistance of purinoceptor to homologous desensitization, and unidirectional desensitization between ATP and other receptors such as ET and glutamate receptors, suggesting a dominant role of purinoceptor in modulating calcium signal of astrocytes.

Molecular cloning and expression analysis of a mouse phospholipase C-delta1.

We describe here the molecular cloning and expression analysis of mouse PLC-delta1 (mPLC-delta1), a key enzyme in cell signal transduction. A mouse brain cDNA library was screened in order to isolate the mPLC-delta1 cDNA. The mPLC-delta1 cDNA was 2660 bp in length. The predicted open reading frame encodes a protein of 756 amino acids with an estimated molecular mass of 85 kDa. The deduced amino acid sequence exhibits 96.9% and 92.7% identity with the sequence of rat and human PLC-delta1, respectively. The mPLC-delta1 mRNA was highly expressed in brain, heart, lung, and testis. We found that transcripts of mPLC-delta1 are present in almost all regions of mouse brain examined, implying that the enzyme may play a role in some fundamental cellular process in brain. In male reproductive tract, mPLC-delta1 mRNA was widely expressed in the epididymis as well as in the testis. In situ hybridization studies indicate that distribution of mPLC-delta1 mRNA in mouse testis is discrete and unique. The expression of mPLC-delta1 mRNA was defined in the periphery of each seminiferous tubule, especially in spermatogonia, which might imply that mPLC-delta1 plays a role in proliferation of spermatogonia. To the best our knowledge, this is the first report to demonstrate the high expression of mPLC-delta1 mRNA in spermatogonia of testis. Taken together, these results suggest that mPLC-delta1 may carry out fundamental roles in almost all of mouse tissues, especially in brain and specific roles in testis.