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Y Sunada

Publications and source records attributed to Y Sunada.

71 records · Page 4Linked to original sources
PubMed1994

Dp71 can restore the dystrophin-associated glycoprotein complex in muscle but fails to prevent dystrophy.

Two lines of transgenic mdx mice have been generated that express a 71 kD non-muscle isoform of dystrophin (Dp71) in skeletal muscle. This isoform contains the cysteine-rich and C-terminal domains of dystrophin, but lacks the N-terminal actin-binding and central spectrin-like repeat domains. Dp71 was associated with the sarcolemma membrane, where it restored normal expression and localization of all members of the dystrophin-associated glycoprotein complex. However, the skeletal muscle pathology of the transgenic mdx mice remained severe. These results indicate that the dystrophin C terminus cannot function independently to prevent dystrophic symptoms and confirms predictions based on patient data that both the N and C-terminal domains are required for normal dystrophin function.

Animals↗
PubMed1994

Exogenous Dp71 restores the levels of dystrophin associated proteins but does not alleviate muscle damage in mdx mice.

Dp71 is a non-muscle product of the Duchenne muscular dystrophy gene. It consists of the cysteine-rich and C-terminal domains of dystrophin. We have generated transgenic mdx mice which do not have dystrophin but express Dp71 in their muscle. In these mice, Dp71 was localized to the plasma membrane and restored normal levels of dystrophin associated proteins (DAPs), indicating that Dp71 is capable of interacting with the DAPs in a similar manner to dystrophin. However, the presence of Dp71 and DAPs in the muscle fibres of mdx mice was not sufficient to alleviate symptoms of muscle degeneration.

Animals↗
PubMed1994

Prevention of dystrophic pathology in mdx mice by a truncated dystrophin isoform.

The C-terminal domain of dystrophin is alternatively spliced to produce a variety of tissue and developmental stage-specific isoforms. Recent studies suggest that the C-terminal domain binds to the dystrophin-associated glycoprotein complex (DGC) in muscle, but little is known about the functional significance of the alternative splicing or what role individual isoforms may play in specific tissues. The major dystrophin transcript in brain lacks exons 71-74, and encodes an isoform not observed in skeletal muscle. To explore the capacity of this truncated isoform to function in muscle, we have generated transgenic mice expressing a murine dystrophin mini-gene missing exons 71-74. Uniform expression of this construct on a mutant mdx mouse background results in normal muscle morphology and physiology, and prevents the development of muscular dystrophy. These mice also display normal expression and localization of the DGC, suggesting that the alternatively spliced exons are not required for dystrophin function in skeletal muscle. An additional line of mice was analyzed that had a mosaic pattern of expression. These mice display a markedly milder phenotype than mdx mice, despite the expression of dystrophin in only half the muscle fibers. These results indicate that viral delivery of dystrophin to a simple majority of fibers in a muscle group would greatly reduce the dystrophic pathology associated with Duchenne muscular dystrophy.

Alternative Splicing↗
PubMed1994

Congenital muscular dystrophy with merosin deficiency.

Congenital muscular dystrophy is one of the most frequent and severe childhood muscular dystrophies. Several forms of this disease have been described. The form associated with marked central nervous system disturbances, frequent in Japan, is known as Fukuyama congenital muscular dystrophy and was recently linked to chromosome 9. The most frequent form observed in occidental countries appears to be clinically characterized by exclusive involvement of skeletal muscle, and has been identified by clinico-pathological features which are often fallacious. A predominant histopathological feature is the marked increase in endomysial collagen tissue. We investigate whether laminin, a major component of the extracellular matrix, which is linked to the subsarcolemmal cytoskeleton by a large oligomeric complex of dystrophin-associated glycoproteins, could be involved in this form. We observed a specific absence of merosin, the laminin M chain, in 13 patients affected by classical non-Japanese form of congenital muscular dystrophy. This result allows the precise identification of a particular form of congenital muscular dystrophy and gives a clue to understanding its molecular pathogenesis.

Child↗
PubMed1993

Inherited amyloid polyneuropathy type IV (gelsolin variant) in a Japanese family.

We describe a Japanese family with familial amyloid polyneuropathy type IV. The family originates from central Japan, Nagano prefecture, and is unrelated to Finnish or other Caucasian populations. Of 42 members in three generations, 14 individuals (5 men, 9 women) are affected by corneal lattice dystrophy, cranial neuropathy, mild peripheral neuropathy, and skin changes. Polarizing microscopy and immunohistochemistry studies of skin biopsy samples demonstrated abundant amyloid deposits, which bound an antigelsolin monoclonal antibody. Direct sequence analysis of a DNA fragment spanning codon 187 of plasma gelsolin complementary DNA and restriction analysis using a modified polymerase chain reaction demonstrated a single base substitution, guanine to adenine, at nucleotide position 654, which is identical to the mutation in Finnish familial amyloid polyneuropathy type IV. This strongly suggests that the mutation causes the familial amyloid polyneuropathy type IV phenotype regardless of ethnic background.

Adult↗
PubMed1993

Lattice corneal dystrophy type II with familial amyloid polyneuropathy type IV.

Lattice corneal dystrophy type II with familial amyloid polyneuropathy type IV (Finnish type, Meretoja's syndrome, FAP-IV) has not been reported in Japan to date. In this study we report on 7 cases in a Japanese family which we recently examined. The proband, a 64-year-old man, suffering from itching in his limbs, impaired lip movement and dysarthria, consulted the Department of Neurology, University of Tokyo. Neurological examinations revealed bilateral facial, glossopharyngeal, vagal and hypoglossal nerve palsies, and also impaired distal vibratory perception. Immunohistological and biochemical studies confirmed the diagnosis of FAP-IV. Ophthalmological examinations showed his vision was 1.2 with fine lattice corneal dystrophy in both eyes. The lattice dystrophy was randomly scattered with short glassy lines. Corneal sensation was normal and there was no evidence of recurrent corneal erosion. Six family members with similar lattice corneal dystrophies also were suspected to be affected neurologically by FAP-IV. The family pedigree suggested an autosomal dominant trait of inheritance.

Adult↗
PubMed1993

[Lattice corneal dystrophy type II with familial amyloid polyneuropathy type IV].

Lattice corneal dystrophy type II associated with familial amyloid polyneuropathy type IV (Finish type, FAP-IV) has not yet been reported in Japan. We report 7 cases in a Japanese family. The proband, a 64-year-old man, suffering from itching in his limbs, impaired lip movement, and dysarthria, consulted the Department of Neurology, University of Tokyo. Neurological examination revealed bilateral facial, glossopharyngeal, vagal, and hypoglossal nerve palsy, and impaired distal vibratory perception. His vision was 1.2 and he had fine lattice corneal dystrophy in both eyes. Short glassy lines were randomly scattered in the lattice dystrophy. Corneal sensation was normal and there was no evidence of recurrent corneal erosion. Immunohistological and biochemical studies confirmed the diagnosis of FAP-IV. Six siblings were neurologically suspected to be FAP-IV patients with similar lattice corneal dystrophy. The family pedigree suggested an autosomal dominant trait of inheritance.

Adult↗
PubMed1992

Soybean protein-dependent changes in triacylglycerol synthesis and concentration of diacylglycerol in the liver microsomes of fasted-refed rats.

Effects of soybean protein, casein and whole egg protein on various indices for lipid biosynthesis in the liver were compared in fasted-refed rats. Soybean protein compared to casein and whole egg protein significantly reduced activities of glucose 6-phosphate dehydrogenase and fatty acid synthetase. The protein source also slightly reduced the activity of the malic enzyme. Soybean protein compared to other proteins not only reduced the microsomal triacylglycerol but also phosphatidylcholine syntheses when the activities were measured with endogenous diacylglycerol substrate. The protein-dependent changes disappeared, if artificial dispersion of dioleoylglycerol was employed as a substrate. The concentrations of microsomal diacylglycerol and triacylglycerol in whole liver in rats fed soybean protein were lower than those fed other proteins. When the diets containing soybean protein and casein were supplemented with DL-methionine (0.5 and 0.3%, respectively) to meet the nutritional requirement of the animals, soybean protein-dependent reductions in these indices for lipid biosynthesis were still detectable but considerably attenuated. Thus, it is plausible that a soybean protein-dependent decrease in fatty acid synthesis reduced the availability of microsomal diacylglycerol substrate for triacylglycerol synthesis and in turn modified hepatic triacylglycerol concentration. The dietary availability of sulfur amino acids may, at least in part, be responsible for the consequence observed in the present study.

Animals↗
PubMed1992

[Familial amyloidotic polyneuropathy type IV (Finnish type)--the first description of a large kindred in Japan].

Familial amyloidotic polyneuropathy type IV, one of the hereditary systemic amyloidoses with an autosomal dominant trait, is clinically characterized by cranial neuropathy and corneal lattice dystrophy. Recent biochemical studies have indicated that the amyloid fibril protein in FAP IV is related to gelsolin, an actin-modulating protein. Cases were clustered in the Finnish population and only a few cases have been reported from other populations. Here we described a large kindred with FAP IV as the first report in Japan. This family comprises 42 members in three generations with 14 affected individuals. We examined 7 patients at the age ranging from 43 to 80 years. All cases have corneal lattice dystrophy type II. The disease begins with slowly progressive facial weakness in the fifth or sixth decade of life and consequently the V, XII, IX and X cranial nerves become involved. Peripheral neuropathy of the extremities remained mild until late of life. Microscopy of skin biopsy samples showed deposits of amyloid around the eccrine glands, sebaceous glands, epidermal-dermal junction and blood vessel walls. Immunohistochemistry of the skin revealed the immunopositive material against a monoclonal antibody to gelsolin in the amyloid deposits. Molecular analysis of the gelsolin gene is now in progress.

Adult↗
PubMed1992

[Gene analysis of Japanese patients with familial amyloidotic polyneuropathy type IV].

Familial amyloidotic polyneuropathy type IV (FAP IV) is clinically characterized by slowly progressive cranial neuropathy and corneal lattice dystrophy. More than 300 cases were clustered in the Finnish population. Recent biochemical studies have demonstrated that the amyloid fibril protein in FAP IV is related to Asn-187 variant gelsolin, and the corresponding missense mutation, a G to A substitution at nucleotide 654 of plasma gelsolin cDNA, cosegregates with the disease phenotype in Finnish families. Here we analyzed the gelsolin gene of the Japanese family with FAP IV which we described as the first Japanese case. Direct sequence analysis of PCR-amplified DNA fragments spanning the codon 187 of plasma gelsolin cDNA from the 2 affected family members demonstrated a single base substitution, G to A at nucleotide 654, which is identical to the mutation of Finnish FAP IV. Restriction analysis using a modified PCR revealed that three unaffected family members and three unrelated healthy controls were homozygous for the normal allele, whereas the seven affected family members were heterozygous for the normal and the mutated alleles. This indicates the cosegregation of the mutation with the disease phenotype in this Japanese family, suggesting that the mutation causes the FAP IV phenotype regardless of ethnic background.

Alleles↗
PubMed1990

Degradation of connectin (titin) in Fukuyama type congenital muscular dystrophy: immunochemical study with monoclonal antibodies.

Connectin (also called titin) is a myofibrillar elastic filament which links a thick filament to a neighbouring Z line in a sarcomere and thus contributes significantly to the elasticity of myofibrils. In a previous study, we demonstrated by Western blot analysis of the biopsied skeletal muscles using an anti-connectin monoclonal antibody that connectin was degraded extensively after 5 years of age in Duchenne muscular dystrophy (DMD), while it was degraded mildly in Becker muscular dystrophy and only minimally in myotonic dystrophy, limb girdle dystrophy, amyotrophic lateral sclerosis and Charcot-Marie-Tooth disease. In the present study, we investigated the degradation state of connectin in Fukuyama type congenital muscular dystrophy (FCMD) by a similar method using 2 distinct anti-connectin monoclonal antibodies. In FCMD, connectin degradation began much earlier than in DMD: Definite degradation was already observed in 5-8-month-old patients. It was presumed that connectin degradation would play an important role in the myofibrillar degeneration in the early stage of FCMD.

Antibodies, Monoclonal↗
PubMed1989

[Multicystic encephalomalacia in an adult--a case report].

A case of multicystic encephalomalacia found in adult life was described. A 35-year-old man was admitted to our hospital with a chief complaint of unsteadiness. He had developed normally until he fell into the shock state induced by mismatch blood transfusion at the age of 15 months. Since then he has been mentally retarded moderately and had clumsiness of the skillful movement in the right hand. The other neurological abnormality was hyperreflexia only. Laboratory examination failed to disclose metabolic defect. Both CT scan and MRI demonstrated numerous cystic lesions of various size spreading over bilateral cerebral white matter partially involving the inner layer of the cortex. On the contrary basal ganglia, cerebellum and brainstem were completely spared. The diagnosis of MCE was made from (1) anoxic-ischemic episode in infancy, (2) static clinical picture and (3) characteristic distribution of cystic lesions. It is well known that MCE results from perinatal hypoxia, but it is a polyetiologic condition caused by various damages to immature brain of early infancy and usually results in severe psychomotor retardation. Nonetheless, it is intriguing in our case that marked discrepancy was found between morphological change and neurological deficit. It is probable that at the age of 15 months the myelination of major projecting fibers was almost completed, but sufficient plasticity was preserved in immature brain. As a result, the patient had the neurological deficit in the minimum degree in spite of severe morphological change.

Adult↗
PubMedDate not supplied

[Report of a patient with CADASIL having a novel missense mutation of the Notch 3 gene--association with alopecia and lumbar herniated disk].

We report a 52-year-old man with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) presenting dementia, alopecia and lumbar herniated disk. He had an episode of stroke and migraine-like headache lasting for 5 minutes. A lot of members had cerebral infarction in this family. Brain magnetic resonance imaging demonstrated, on T2-weighted images, numerous hyperintense lesions suggestive of small infarcts in the basal ganglia and diffuse hyperintense lesions in the cerebral white matter. The clinical symptoms, the family history and the MRI findings suggested the diagnosis of CADASIL. However, the patient also showed alopecia and lumbar herniated disk, both are characteristic features of cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). The DNA analysis of the Notch 3 gene identified a novel missense mutation Cys174Phe in this patient. Our case report indicated the importance of the DNA analysis for the diagnosis of CADASIL.

Alopecia↗