Shigeo Hashimoto

Treatment of Kearns‐Sayre syndrome with coenzyme Q10

We studied the metabolism of coenzyme Q10 (CoQ) and the effects of CoQ therapy in five patients with Kearns-Sayre syndrome (KSS). Although the mitochondrial fraction was increased in muscles from KSS patients, CoQ content was slightly low. CoQ synthesis was normal in fibroblasts from KSS patients. Administration of 120 to 150 mg/d of CoQ improved abnormal metabolism of pyruvate and NADH oxidation in skeletal muscle. CoQ therapy decreased CSF protein concentration and CSF lactate/pyruvate ratio. ECG abnormalities and neurologic symptoms also improved.

Abnormal distribution of cathepsins in the brain of patients with Alzheimer's disease

Formalin-fixed paraffin-embedded hippocampal sections of brains with early-onset and late-onset Alzheimers disease were studied immunohistochemically with antisera against cathepsin D and cathepsin B. In addition to the staining of neuronal perikarya, some of the senile plaques visualized by Bielshowsky silver staining and some of reactive astrocytes were positively stained with the antisera against cathepsin D and cathepsin B in brains with Alzheimers disease. Abnormal localization of cathepsin D and cathepsin B immunoreactivity in neuronal perikarya was observed in brains with early-onset Alzheimers disease. These findings demonstrate that the distribution of lysosomal proteases was altered in brains with Alzheimers disease, suggesting the primary and/or secondary involvement of the lysosomal proteases in the pathological process of Alzheimers disease.

Improvement of abnormal pyruvate metabolism and cardiac conduction defect with coenzyme Ql0 in Kearns‐Sayre syndrome

In a patient with Kearns-Sayre syndrome, concentration of coenzyme Ql0, a component of the mito-chondrial electron transport system, was decreased in serum and in the mitochondrial fraction of skeletal muscle. Serum concentrations of lactate and pyruvate were abnormally high, especially after exercise or oral glucose loading. Levels of folic acid in plasma and CSF were decreased. ECG showed a first-degree atrioventricular block. After administration of coenzyme Ql0 60 to 120 mg daily for 3 months, serum levels of lactate and pyruvate became normal, with improvement of atrioventricular block and ocular movements.

Differentiation between dysmyelination and demyelination using magnetic resonance diffusional anisotropy

Using magnetic resonance (MR) diffusion-weighted method, we examined the optic and the trigeminal nerves of jimpy and twitcher mice, considered to be animal models of Pelizaeus-Merzbacher disease, hypomyelination disorder, and Krabbe disease, demyelination disorder, respectively. In jimpy mice, diffusional anisotropy of optic nerve did not show a significant difference compared to age-matched control mice, suggesting that diffusional anisotropy does exist in absence of multiple layers of myelin sheath. In twitcher mice, diffusional anisotropy was attenuated remarkably in the optic and trigeminal nerves. Loss of axonal straightness on longitudinal section confirmed by electron microscopy appeared to be the principal explanation for it. It is further suggested that this MR diffusion-weighted imaging method enables us to differentiate hypomyelination from demyelination in vivo.

The relationship between SDF-1α/CXCR4 and neural stem cells appearing in damaged area after traumatic brain injury in rats

Abstract Objective: The actual relationship between neural stem cells and SDF-1α/CXCR4 after brain injury has not yet been elucidated, although recent studies have speculated that stromal cell-derived factor-1α (SDF-1α) and its receptor, CXCR4, could contribute to neural stem cells migration after brain injury. In the present study, the temporal relationship between neural stem cells (NSCs) and SDF-1α/CXCR4 around a damaged area was investigated using a rat traumatic brain injury (TBI) model. Methods: We used molecular biology techniques and immunohistochemistry to investigate the relationship between SDF-1α/CXCR4 expression and NSCs existence around a damaged area after TBI in the rat brain. Results: SDF-1α mRNA expression and SDF-1α protein synthesis did not increase after TBI. However, SDF-1α leaked from the injured area and diffused into the cortex 1–3 days after TBI. Subsequently, the levels of CXCR4 mRNA expression and CXCR4 protein synthesis increased significantly. Many small cells with a nestin-positive cytoplasm and fibers also showed immunopositivity for both CXCR4 and SOX-2, but not for GFAP, 3–7 days after TBI. Moreover, a proportion of the CXCR4-positive cells and fibers also showed immunostaining for neurofilaments. Discussion: These results suggest that the leaked SDF-1α attracted CXCR4-positive NSCs as well as elongated nerve fibers. It is considered that the SDF-1α/CXCR4 system in the brain contributes to neural stem cells appearance and maturation after TBI. Therefore, exploitation of the SDF-1α/CXCR4 system around a damaged area may improve the brain dysfunction after TBI.

Expression of amyloid precursor protein after rat traumatic brain injury.

Abstract Objective: Previous reports have demonstrated that some focal brain injuries increase amyloid precursor protein (APP) immunoreactivity in the region surrounding the injury in the cerebral cortex. However, the chronologic changes in APP expression have not been evaluated after traumatic brain injury (TBI). Methods: In this study, we immunohistochemically and biologically investigated chronologic changes in cellular sources and levels of APP production after rat TBI. Results: In the present report, we show that traumatic brain injury increased the expression of APP in the neuronal perikarya and in damaged dystrophic neurites from 1 to 90 days after injury. Moreover, 7 days after injury, some macrophages/microglia also were co-localized with APP, which was overproduced by the neuronal perikarya and APP-positive dystrophic neurites after injury and then APP were phagocytosed by macrophages/microglia during this phase. However, astroglia did not express APP immunopositivity after brain injury. Discussion: These results suggested that long-term overexpression of APP was confirmed by immunohistochemical and biologic technique after TBI. This may be related to the induction of Alzheimer type dementia and it is a very important risk factor for this disease.

A MORPHOLOGICAL STUDY ON THE EFFECTS OF COLLAGEN GEL MATRIX ON REGENERATION OF SEVERED RAT SCIATIC NERVE IN SILICONE TUBES

The present study is a chronological morphological examination on the effects of collagen gel matrix on regeneration of severed sciatic nerves. The nerves (5 mm length) were resected, and both the distal and proximal stumps were inserted into a silicone tube with 5 mm gap in between. In the test side, the gap in the tube was then injected with liquid collagen which gells in the tissue when reconstructed with a certain buffer solution. The gap space in the tube of the control side was left empty. In a chronological examination of the tissue in the tube, considerably more rapid growth of sprouting axons toward the distal stump in the test side was revealed in comparison with the control side. The cells, including both fibroblasts and larger Schwann cells, were less in number. More orderly directions were observed in the collagen matrix than in the control tube. The result indicates that regeneration of the peripheral nerves in the silicone tube can be improved, by using appropriate exogenous fine materials, collagen matrix.

Cumulative white matter changes in the gerbil brain under chronic cerebral hypoperfusion

SummaryAn animal model of chronic brain hypoperfusion has been developed by applying coiled clips to the bilateral carotid artery of Mongorian gerbils. The brain tissue damage was neuropathologically studied after 1, 4, 8, and 12 weeks of hypoperfusion. The hippocampus, basal ganglia, and cerebral cortex of the chronically hypoperfused gerbil showed lesions with various severity which are probably due to ischemic episodes. In the cerebral white matter, however, two types of lesions were observed; one similar to those in the gray matter, and the other observed only in the white matter after more than an 8-week duration of brain hypoperfusion. The lesion specific to the white matter showed rarefaction and gliosis without locally associated ischemic changes. This type of the white matter lesion was never found in the gerbil brain before 8 weeks and, significantly, increased in number and size by 12 weeks post operation. The accumulation of the white matter lesions is characteristic in the gerbil with chronic hypoperfusion. The observed white matter-specific lesion resembles the histological changes in aged brain with cerebrovascular diseases.

Immature and mature neurons coexist among glial scars after rat traumatic brain injury

Abstract Objectives: Glial scars around a damaged area after brain injury inhibit neurite elongation from surviving neurons and axonal plasticity, and thus prevent neural network regeneration. However, the generation, differentiation and maturation of neural stem cells (NSCs) among glial scars after brain injury have not yet been reported. Methods: In the present study, we investigated the chronological relationship between gliosis and maturation of new neurons around a damaged area using a rat traumatic brain injury (TBI) model. Results: Between 1 and 7 days after injury, many nestin-positive cells were observed around the damaged area. Three days after injury, many small nestin-positive cells showed an astrocytic morphology. Between 1 and 30 days after injury, doublecortin (DCX)-positive cells were present around the damaged area. Three and 7 days after injury, a small number of nestin-positive cells were immunopositive for glial fibrillary acidic protein (GFAP). Seven days after injury, there were DCX-positive cells in the gliosis occurring in the lesion. Thirty days after injury, DCX-positive cells were observed near and among the glial scars and a small number of these cells were immunopositive for NeuN. Discussion: These results suggest that DCX-positive cells were present near and among the glial scars after brain injury, and that these cells changed from immature to mature neurons. It is considered that promotion of the maturation and differentiation of newly formed immature neurons near and among glial scars after injury may improve the brain dysfunction induced by glial scars after brain injury.

Cultured Rat Astrocytes Give Rise to Neural Stem Cells

Previously, we reported the occurrence of neural stem cells (NSCs) around an area of damage after rat traumatic brain injury (TBI), but it was unclear if this was due to blastgenesis in astrocytes, or to NSCs migrating from the subventricular zone (SVZ). In this study, NSCs were isolated and cultured from cultured type 1 astrocytes taken from newborn rat cortex in which the subventricular zone and hippocampus had been discarded. All cultured type 1 astrocytes showed glial fibrillary acidic protein (GFAP) immunopositivity. Nestin immunopositive spheres were isolated from type 1 astrocytes and cultured in the presence of bFGF and EGF in the medium. Neurospheres differentiated into Tuj1-, GFAP- and A2B5-positive cells after 4 days of culture without bFGF and EGF. These results indicate that isolated neurospheres from brain cortex astrocytes can differentiate into neurons and glia and might contribute to neurogenesis and neuroplasticity.