Kunio Tashiro

Amelioration of experimental autoimmune encephalomyelitis in C57BL/6 mice by an agonist of peroxisome proliferator-activated receptor-γ

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma), a member of the nuclear hormone receptor superfamily, plays a critical role in adipocyte differentiation and glucose homeostasis. It has been implicated that PPAR-gamma functions as a regulator of cellular proliferation and inflammatory responses. In the present study, we examined whether troglitazone, a selective PPAR-gamma agonists, ameliorated experimental autoimmune encephalomyelitis (EAE) induced by administration of myelin oligodendrocyte glycoprotein (MOG) peptide 35-55 in C57BL/6 mice. We found that troglitazone attenuated the inflammation and decreased the clinical symptoms. It was suggested that the amelioration was attributed to the attenuation of pro-inflammatory cytokine gene expressions.

Glycation—a sweet tempter for neuronal death

Glycation, one of the post-translational modifications of proteins, is a nonenzymatic reaction initiated by the primary addition of a sugar aldehyde or ketone to the amino groups of proteins. In the early stage of glycation, the synthesis of intermediates leading to the formation of Amadori compounds occurs. In the late stage, advanced glycation end products (AGE) are irreversibly formed after a complex cascade of reactions. Several AGEs have been characterized chemically, while other new compounds remain to be identified. To date, studies of the contribution of glycation to diseases have been primarily focused on its relationship to diabetes and diabetes-related complications. However, glucose-induced damage is not limited to diabetic patients. Although it does not cause rapid or remarkable cell damage, glycation advances slowly and accompanies every fundamental process of cellular metabolism. It has recently become clear that glycation also affects physiological aging and neurodegenerative diseases such as Alzheimers disease and amyotrophic lateral sclerosis. Glycation alters the biological activity of proteins and their degradation processes. Protein cross-linking by AGE results in the formation of detergent-insoluble and protease-resistant aggregates. Such aggregates may interfere with both axonal transport and intracellular protein traffic in neurons. In addition, glycation reactions lead to the production of reactive oxygen species. Conversely, glycation is promoted by oxidative stress. We speculate on the presence of synergism between glycation and oxidative stress. In this review, we provide an outline of glycation and propose some possible mechanisms of its cytotoxicity and defense systems against it.

Neurotoxicity of methylglyoxal and 3‐deoxyglucosone on cultured cortical neurons: Synergism between glycation and oxidative stress, possibly involved in neurodegenerative diseases

In this study, we investigate the neurotoxicity of glycation, particularly early‐stage glycation, and its mechanisms, which are possibly synergized with oxidative stress. Methylglyoxal (MG) and 3‐deoxyglucosone (3DG), intermediate products of glycation, are known to further accelerate glycation and advanced glycation endproducts (AGEs) formation. Both compounds showed neurotoxicity on cultured cortical neurons and these effects were associated with reactive oxygen species production followed by neuronal apoptosis. Pretreatment with N‐acetylcysteine induced neuroprotection against MG and 3DG. Cotreatment, but not pretreatment, with aminoguanidine protected neurons against the neurotoxicities of both compounds. The present study provides the first evidence that MG and 3DG are neurotoxic to cortical neurons in culture. Interference with the process by which glycation and AGEs formation occur may provide new therapeutic opportunities to reduce the pathophysiological changes associated with neurodegeneration, if, as indicated here, the participation of glycoxidation in the pathogenesis of neurodegenerative diseases is essential. J. Neurosci. Res. 57:280–289, 1999.

Macrophage inflammatory protein-1α in the cerebrospinal fluid of patients with multiple sclerosis and other inflammatory neurological diseases

The level of macrophage inflammatory protein-1 alpha (MIP-1 alpha), a newly discovered cytokine of chemokine family, was determined in cerebrospinal fluid (CSF) from 18 patients with multiple sclerosis (MS) and from control patients with other neurological disorders by an enzyme-linked immunosorbent assay (ELISA). The concentration of MIP-1 alpha in CSF was significantly elevated in MS in relapse (4.4 pg/ml) compared with non-inflammatory neurological disease control samples (0.3 pg/ml) (p < 0.0002). These concentrations in MS patients correlated well with leukocyte cell counts and protein content in CSF (r = 0.845, p < 0.0001; r = 0.853, p < 0.0001, respectively). In other inflammatory neurological disorders such as Behçets disease and HTLV-1 associated myelopathy, significantly increased CSF levels of MIP-1 alpha were also observed. Chemokines are reported to play an important role in an early event of inflammation such as lymphocyte traffic. This report is the first study which confirmed the involvement of a chemokine in MS and other inflammatory neurological disorders.

Identification of cell types producing RANTES, MIP-1α and MIP-1β in rat experimental autoimmune encephalomyelitis by in situ hybridization

The chemokines RANTES, macrophage inflammatory protein (MIP)-1α and MIP-1β are members of the β-family of chemokines and potent chemoattractants for lymphocytes and monocytes. To investigate the factors which regulate lymphocyte traffic in experimental autoimmune encephalomyelitis (EAE), we studied, by in situ hybridization analysis, the kinetics of mRNA expression and the potent cellular sources of RANTES, MIP-1α and MIP-1β in the central nervous system (CNS) during the course of EAE. RANTES-positive cells appeared in the subarachnoid space and infiltrated the subpial region at around day 10, increased to a peak at days 12–13 and then decreased following the resolution of the acute phase of EAE, though elevated RANTES message expressions still remained on chronic subclinical stage. Most of RANTES positive cells were identified as T-lymphocytes located mainly around blood vessels, by combined studies of in situ hybridization and immunohistochemistry. The remainder of the RANTES-positive cells were astrocytes and macrophages/microglia. MIP-1α and MIP-1β mRNA-positive cells appeared around day 10, increased further on days 12–13 and then gradually decreased. Most of the MIP-1α- and MIP-1β-positive mononuclear cells were located around blood vessels. The kinetics of RANTES, MIP-1α and MIP-1β expression paralleled those of the recruitment of infiltrating inflammatory cells and disease severity. Our observations support the possibility that chemokine production by T-cells, macrophages and astrocytes lead to the infiltration of inflammatory cells into the CNS parenchyma during the acute phase of EAE.

Deep brain stimulation of subthalamic area for severe proximal tremor

Article abstract Proximal tremors are often refractory to nucleus ventrointermedius thalami thalamotomy. Subthalamotomy has been suggested to be effective for treatment of tremor, although this procedure is associated with considerable adverse effects, and has rarely been considered a suitable treatment modality. The authors demonstrate the efficacy and safety of subthalamic deep brain stimulation in two patients, one with a severe, refractory proximal essential tremor and one with tremor with dystonia.

Vitamin D receptor gene polymorphism in multiple sclerosis and the association with HLA class II alleles

We have previously reported that the association between Bsm I polymorphism, one of the vitamin D receptor genes (VDRG) polymorphism, and multiple sclerosis (MS). In this report, we investigated the further possible role or relevance of VDRG in the pathogenesis of MS. Apa I polymorphism was detected by PCR-RFLP from the DNA of 77 conventional MS patients and 95 healthy controls. The study of the Bsm I and Apa I haplotypes was carried out by employing previously reported Bsm I data. The AA genotype and the [A] allele in the profiles were significantly more prevalent in MS patients than in controls (P=0.0070 and P=0.0321, respectively). In the [A] allele-positive MS patients, the positive rate of DPB1*0501 in HLA was significantly higher than that of the [A] allele-positive controls and that of the [A] allele-negative MS patients even when the corrected P value (P(corr)) was applied (P(corr)=0.0220 and P(corr)=0.0077, respectively). The frequency of DRB1*1501 was higher in the [A] allele-positive patients than in the [A] allele-positive controls and the [A] allele-negative patients (P(uncorr)=0.0431 and P(uncorr)=0.0089, respectively), but the P values did not reach statistical significance after P corrections. The rate of Bsm I and Apa I haplotypes was much higher in bA/bA-positive MS patients than in the controls (P=0.0003), and in the bA positive MS patients, the positive rate of DPB1*0501 was higher than that of the bA-positive controls and that of the bA-negative MS patients (P(corr)=0.0308 and P(corr)=0.0033, respectively). These results indicate that VDRG polymorphism may be associated with susceptibility to MS, and HLA alleles may correlate with risk for MS together with VDRG.

Effect of 1,25-dihydroxyvitamin D3 on cultured mesencephalic dopaminergic neurons to the combined toxicity caused by L-buthionine sulfoximine and 1-methyl-4-phenylpyridine

A decrease in intracellular glutathione content may be related to the primary event in Parkinsons disease, so increasing the glutathione level may have a therapeutic benefit. The biologically active form of vitamin D, 1,25‐dihydroxyvitamin D3 [1,25‐(OH)2D3] has been recently reported to enhance the intracellular glutathione concentration in the central nervous system. Exposing rat cultured mesencephalic neurons for 24 hr to a mixture of L‐buthionine sulfoximine (BSO) and 1‐methyl‐4‐phenylpyridium ions (MPP+) resulted in a relatively selective damage to dopaminergic neurons. This damage has been accompanied by a reduction of intracellular glutathione levels. Low doses, i.e., 1–100 nM, of 1,25‐(OH)2D3 protect cultured dopaminergic neurons against this toxicity, although higher concentrations of this active form of vitamin D have been found to enhance the toxic effect. Generation of reactive oxygen species (ROS) by this toxicity has been attenuated in cultures being pretreated with low concentrations of 1,25‐(OH)2D3. Because the hormone increases the intracellular glutathione content in cultures, determining how this hormone suppresses ROS generation may involve the enhancement of the antioxidative system. These data suggest that low doses of 1,25‐(OH)2D3 are able to protect mesencephalic dopaminergic neurons against BSO/MPP+‐induced toxicity that causes a depletion in glutathione content. J. Neurosci. Res. 62:374–382, 2000.

Nationwide survey of juvenile muscular atrophy of distal upper extremity (Hirayama disease) in Japan

Juvenile muscular atrophy of the distal upper extremity (JMADUE, Hirayama disease) was first reported in 1959 as ‘juvenile muscular atrophy of unilateral upper extremity’. Since then, similar patients in their teens or 20s have been described, under a variety of names, not only in Japan, but also in other Asian countries, as well as Europe and North America. Biomechanical abnormalities associated with JMADUE have recently been reported through various imaging examinations, proposing its disease mechanism. Since JMADUE differs from motor neuron disease, or spinal muscular atrophy, this disease entity should be more widely recognized, and early detection and effective treatments should be considered. We report an epidemiological study in Japan. Two nationwide questionnaire‐based surveys, conducted in Japan from 1996 to 1998, identified 333 cases. The numbers of patients per year, distribution of ages at onset, mode of onset, time lapse between onset and quiescence, neurological signs and symptoms, imaging findings, and the effects of conservative treatments were analyzed. The peak age was 15 to 17 years, with a marked male preponderance, usually a slow onset and progression, and quiescence six or fewer years after onset. There was a predominantly unilateral hand and forearm involvement with ‘cold paresis’. The imaging findings are described.

Macrophage migration inhibitory factor in the cerebrospinal fluid of patients with conventional and optic-spinal forms of multiple sclerosis and neuro-Behcet's disease

Macrophage migration inhibitory factor (MIF) is becoming increasingly recognized as an important regulator of immune and inflammatory responses. It is released by activated T lymphocytes and macrophages and up-regulates the proinflammatory activity of these cells. MIF is required for antigen- and mitogen-driven T cell activation, and stimulates macrophages to release cytokines and nitric oxide. On the basis of the recent suggestion that pharmacological modulation of MIF production and neutralization of its activity may have important implications for treatment of a variety of autoimmune or inflammatory conditions, we determined the level of MIF in the cerebrospinal fluid (CSF) of patients with conventional-form multiple sclerosis (C-MS) and optic-spinal form multiple sclerosis (OpS-MS), and neuro-Behçets disease (NBD). As control, the CSF of patients with non-inflammatory neurological diseases (NIND) was used. The concentration of MIF in CSF samples was significantly elevated in relapsed cases of C-MS (4.13+/-1.07 ng/ml) (mean+/-S.D.) compared with control samples (2.38+/-0.60 ng/ml) (P<0.0001), whereas MIF in the CSF of C-MS patients in remission was not elevated (2.65+/-0.67 ng/ml). The concentration of MIF in the CSF of OpS-MS patients in relapse (5.53+/-1.74 ng/ml) was higher than that of patients with C-MS in relapse (P<0.05). In NBD patients, the concentration of MIF in CSF was significantly elevated (7.47+/-5.61 ng/ml) compared with control samples (P<0.01) and correlated well with cell count in these samples (r=0.910, P<0.005). These results suggest that MIF may play a pivotal role in immune-mediated diseases of the central nervous system, and that MIF may be useful in the study of differences between C-MS and OpS-MS.