Yoko Fukuhara

PI3K is a key molecule in the Nrf2-mediated regulation of antioxidative proteins by hemin in human neuroblastoma cells

Oxidative stress and ferrous metabolism are important in the pathogenesis in Parkinsons disease. In dopaminergic neurons, several stress proteins are upregulated under oxidative stress. To clarify this mechanism, we investigated hemin‐related signal transduction and the induction of oxidative stress‐related proteins in SH‐SY5Y cells. We identified phosphatidylinositol 3‐kinase (PI3K) and Nrf2 as important molecules in the induction of heme oxygenase‐1, thioredoxin, and peroxiredoxin‐I. PI3K‐related signal controlled Nrf2 activation, and consequently, PI3K inhibitors blocked the nuclear translocation of Nrf2 and induction of stress proteins. These observations suggest that PI3K and Nrf2 are key molecules in maintaining suitable conditions under oxidative stress and ferrous metabolism.

Population-based door-to-door survey of migraine in Japan: The Daisen Study

Objectives.—To determine prevalence and characteristics of migraine in Japan, and to investigate use of medical care and whether food preference is associated with risk of migraine.

Transcriptional activation of p62/A170/ZIP during the formation of the aggregates: possible mechanisms and the role in Lewy body formation in Parkinson's disease.

Formation of intracellular inclusion bodies due to defects in the protein degradation machinery is associated with the pathogenesis of neurodegenerative diseases. Sequestosomal protein p62/A170/ZIP, which is an oxidative stress-related protein and a ubiquitin-binding protein, is a component protein of Lewy bodies that are observed in patients with Parkinsons disease. The association of p62 with poly-ubiquitinated proteins may be an important step in the formation of intracellular protein aggregates like Lewy bodies. To study the role of p62 in the formation of protein aggregates in PC12 cells, we monitored the intracellular localizations of p62 and ubiquitinated proteins and the levels of both components during treatment with MG132, a proteasome inhibitor. In the early stage of aggregate formation, p62 did not always co-localize with ubiquitin. In contrast, these proteins were always co-localized in later stages. After the treatment of the cells with MG132, we found that the expression level of p62 increased due to the transcriptional activation of the gene and that higher molecular sizes of p62, corresponding to mono- and di-ubiquitinated formes, were also formed. Both the transcriptional inhibitor actinomycin D and an antisense oligonucleotide of p62 inhibited the MG132-mediated increase of p62, the sequestration of ubiquitinated proteins, and the enlargement of the aggregates. Furthermore, p62-positive aggregates were observed primarily in surviving cells. Together, these results suggest that p62 plays an important role in the protection of cells from the toxicity of misfolded proteins by enhancing aggregate formation especially in the later stages.

Pro-apoptotic protein glyceraldehyde-3-phosphate dehydrogenase promotes the formation of Lewy body-like inclusions.

Glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) has long been recognized as a classical glycolytic protein; however, previous studies by our group and others have demonstrated that GAPDH is a general mediator initiating one or more apoptotic cascades. Our most recent findings have elucidated that an expression of a pro‐apoptotic protein GAPDH is critically regulated at the promoter region of the gene. Apoptotic signals for its subsequent aggregate formation and nuclear translocation are controlled by the respective functional domains harboured within its cDNA component. In this study, coexpression of GAPDH with either wild‐type or mutant (A53T) α‐synuclein and less likely with β‐synuclein in transfected COS‐7 cells was found to induce Lewy body‐like cytoplasmic inclusions. Unlike its full‐length construct, the deleted mutant GAPDH construct (C66) abolished these apoptotic signals, disfavouring the formation of inclusions. The generated inclusions were ubiquitin‐ and thioflavin S‐positive appearing fibrils. Furthermore, GAPDH coimmunoprecipitated with wild‐type α‐synuclein in this paradigm. Importantly, immunohistochemical examinations of post mortem materials from patients with sporadic Parkinsons disease revealed the colocalized profiles immunoreactive against these two proteins in the peripheral zone of Lewy bodies from the affected brain regions (i.e. locus coeruleus). Moreover, a quantitative assessment showed that about 20% of Lewy bodies displayed both antigenicities. These results suggest that pro‐apoptotic protein GAPDH may be involved in the Lewy body formation in vivo, probably associated with the apoptotic death pathway.

Static stabilometry in patients with migraine and tension-type headache during a headache-free period

Abstract The vestibulospinal system was evaluated using a stabilometric method in patients with migraine and episodic tension‐type headache during headache‐free periods. Migraine patients often complain of dizziness or vertigo during headache attacks and some exhibit these symptoms between attacks. Computerized static stabilometry is a reliable and non‐invasive technique to evaluate the equilibrium function in various diseases. The subjects consisted of 21 patients with migraine, 12 patients with episodic tension‐type headache and, age‐ and sex‐matched controls. We performed two sets of static stabilometric measurements with eyes open (EO) and eyes closed (EC) for 30 s. The averages of two sessions of the following six stabilometric parameters were used for the analysis: locus length (LNG), environmental area (ENV‐AREA), rectangle area (REC‐AREA), locus length per second, locus length per environ area (L/E), and root mean square area. Romberg quotients (EC/EO) of these six parameters were also analyzed. The mean values of LNG, ENV‐AREA and REC‐AREA in the EC session in the migraine group were significantly greater than those in the controls (P < 0.05, Mann–Whitney rank sum test). Romberg quotients of all stabilometric parameters except the L/E in the migraine group were significantly greater than in the controls. Patients with episodic tension‐type headache did not show any differences in the stabilometric study from the controls. The present findings suggest that patients with migraine show a significant increase of the body sway during the EC session, which indicates an underlying dysfunction in the vestibulospinal system.

GAPDH knockdown rescues mesencephalic dopaminergic neurons from MPP+ -induced apoptosis.

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH; EC 1.2.1.12) has a number of diverse functions apart from glycolytic function. We explored the possible involvement of GAPDH in 1-methyl-4-phenylpyridinium (MPP+)-induced death of mesencephalic dopaminergic neurons (MDNs) in culture. MPP+ (10 and 20 μM, 24 h) exposure selectively decreased the survival of tyrosine hydroxylase positive (TH+) MDNs, which manifested apoptotic features including shrinkage of the cell body, chromatin condensation and nuclear fragmentation. Two types of GAPDH antisense oligonucleotides almost completely rescued MDNs from MPP+ toxicity. GAPDH was strongly expressed in apoptotic TH+ neurons, and MPP+ exposure significantly increased the percentage of TH+ neurons in which GAPDH is over-expressed. Confocal microscopic analysis demonstrated the nuclear accumulation of GAPDH in neurons undergoing MPP+-induced apoptosis. These results suggest that MPP+ causes apoptosis of MDNs, concomitant with the over-expression and nuclear accumulation of GAPDH.

Increased plasma transforming growth factor-β1 in migraine

Background and Objectives.—Migraine is characterized by the peripheral and central sensitization of pain perceptive neural systems, and neurogenic inflammation is a key step in the development of migraine headache. We focused on transforming growth factor‐β1 (TGF‐β1), which is a multifunctional proinflammatory cytokine. To address the possibility of TGF‐β1 involvement in migraine, we investigated the plasma level of TGF‐β1 in patients with migraine headache during headache‐free periods.