Shuji Mita

Cloning and sequence analysis of cDNA for human prealbumin.

A cDNA coding for human prealbumin has been cloned from a cDNA library prepared from human liver. The DNA sequence codes for a polypeptide which consists of 147 amino acids including a whole human prealbumin sequence and a putative signal sequence. The elucidation of this prealbumin cDNA sequence is expected to facilitate a prenatal diagnosis of familial amyloidotic polyneuropathy.

Bilateral pallidal stimulation for idiopathic segmental axial dystonia advanced from meige syndrome refractory to bilateral thalamotomy

Meige syndrome is an adult‐onset dystonic movement disorder that predominantly involves facial muscles, while some patients with this syndrome develop spasmodic dysphonia and dystonia of the neck, trunk, arms, and legs. We report that all dystonic symptoms that had been refractory to both pharmacotherapy and bilateral thalamotomy were markedly alleviated by bilateral pallidal stimulation in a patient with segmental axial dystonia advanced from Meige syndrome.

Familial amyloidotic polyneuropathy diagnosed by cloned human prealbumin cDNA

A diagnosis of familial amyloidotic polyneuropathy (FAP) can be made by use of restriction endonuclease Nsi I, a cloned human prealbumin cDNA and Southern blot procedures. Digests of DNAs from 10 disease-free individuals showed two bands (6.6 kb and 3.2 kb) complementary to a human prealbumin cDNA, whereas digests from 11 individuals with FAP exhibited two additional bands (5.1 kb and 1.5 kb). We interpret these changes in pattern to be the result of a restriction site for NsiI located in the altered codon and associated with the mutant prealbumin gene. All these individuals with FAP were heterozygous for the prealbumin gene, carrying one normal and one mutant gene.

Bilateral pallidal stimulation for cervical dystonia: An optimal paradigm from our experiences

We sought to identify optimal paradigms of bilateral globus pallidus internus (GPi) stimulation in 3 subsequent patients with severe cervical dystonia. At low frequency stimulation (50–60 Hz) with wide pulse width (500 µs) and high amplitude (4.5–8.0 V), we observed immediate and consistent improvement of dystonia and dystonia-associated pain. Stimulation of the posteroventral portion of the GPi led to pronounced alleviation of dystonia; stimulation of the anterodorsal portion or at the dorsal border of the GPi resulted in significant worsening of symptoms. The therapeutic benefit obtained by using the optimal stimulation parameters continues and has lasted for at least 1 year in each patient.

PCR and immunocytochemical analyses of dystrophin-positive fibers in Duchenne muscular dystrophy

Immunocytochemical studies on serial sections of muscles from 19 patients with Duchenne muscular dystrophy (DMD) were done using seven kinds of antidystrophin antibodies that span dystrophin. Fifteen of the patients were screened for intragenic deletions by the multiplex polymerase chain reaction (PCR); 7 were also tested, using Southern blots. Dystrophin-positive fibers were detected in 10 of the 19 patients, occurring with a frequency of 0.06-75.7%, as clusters or as single fibers in certain muscle bundles. In 7 of the 10 patients, the fibers stained with all antibodies from the N- through the C-terminal region. However, in one patient, there were dystrophin-positive fibers that stained with an N-terminal antibody (DYS-3) and an antibody specific to the rod region (DYS-1), but not with C-terminal antibody (DYS-2). In 2 patients, there were two kinds of fibers: one that did not stain with DYS-1 or DYS-2 and another that stained with all the antibodies used. Single-fiber PCR analysis in 2 patients showed that the genotype of dystrophin-positive fibers differed from that of dystrophin-negative fibers. These results suggest that the majority of dystrophin-positive fibers are of the same clonal origin, but that some are derived from plural reverse mutations, each with a different translation-frame-repairing modality and somatic mosaicism.

Prealbumin gene expression during mouse development studied by in situ hybridization

Localization of prealbumin mRNA in tissues from mice at various stages of gestation was investigated using in situ hybridization procedures. Prealbumin mRNA was detected as early as the 10th day of gestation. It was specifically localized in endodermal cells of the visceral yolk sac, tela choroidea, and hepatocytes. In the adult mice, prealbumin mRNA was localized in the hepatocytes and choroid plexus epithelial cells. These observations indicate that synthesis of prealbumin mRNA is initiated in several different types of cells at early stages of fetal development.

Exonic trinucleotide repeats and expression of androgen receptor gene in spinal cord from X-linked spinal and bulbar muscular atrophy.

We studied exonic trinucleotide repeats and expression of androgen receptor (AR) gene in the spinal cord from an autopsied patient with X-linked spinal and bulbar muscular atrophy (SBMA). Forty-nine CAG triplet repeats were found in tissues from the spinal cord, cerebrum, cerebellum, cardiac muscle and bladder, while there were 20-24 CAG repeats in these tissues from control subjects, consisting of three patients with amyotrophic lateral sclerosis (ALS) and three patients with lung cancer. Thus, mitotic instability of the AR gene in SBMA may not occur at the level of somatic cells. To determine whether expression of the AR gene in the spinal cord of SBMA differs from that in control subjects, we used quantitative reverse transcriptase (RT)-PCR and Western blot. AR mRNA and protein were detected in the spinal cord from the patient with SBMA, but the levels of both AR mRNA and protein were less than those from the patients with ALS in whom the loss of motor neurons was similar to findings in the patient with SBMA. These findings suggest that structural alteration plus a reduced level of AR in the spinal cord are involved in the pathogenesis of SBMA, resulting in degeneration of motor neurons.

Efficient repetitive gene delivery to skeletal muscle using recombinant adenovirus vector containing the Coxsackievirus and adenovirus receptor cDNA.

To improve adenovirus-mediated gene delivery to skeletal muscle, we have used a recombinant adenovirus vector encoding the human Coxsackievirus and adenovirus receptor (hCAR). Because CAR is expressed at a lower level in rodent myoblasts and muscle fibers than in other tissues, we expected that elevated expression of CAR in skeletal muscle would improve the efficacy of adenovirus-mediated gene transfer. Since the mouse myoblasts, C2C12 cells, showed low sensitivity to infection by recombinant adenovirus 5, we initially infected these cells at a high multiplicity of infection (MOI) of 250 with the recombinant adenovirus containing hCAR cDNA and LacZ gene. Subsequent infection by recombinant adenovirus containing the marker gene, green fluorescence protein, became efficient even at a low MOI of 25. Thus, elevated hCAR expression in mouse muscle fibers made a second virus inoculation at low doses possible. We also demonstrated that the elevated hCAR expression did not influence muscle membrane integrity. Our results suggest that co-expression of CAR and a therapeutic gene by adenovirus vector constitutes a novel strategy to advance gene therapy for hereditary muscle diseases.

Cloning of interleukin 2 mRNAs from human tonsils

Human interleukin 2 (IL-2) mRNAs were cloned from a cDNA library prepared from mitogen-stimulated tonsillar mononuclear cells. One of these clones was sequenced and, using this cDNA as a hybridization probe, Southern blot analysis of the human placental DNA was performed. Our results indicate that there is only one IL-2 gene in the human genome.

Derlin-1 overexpression ameliorates mutant SOD1-induced endoplasmic reticulum stress by reducing mutant SOD1 accumulation

Unfolded protein responses, including induction of stress sensor kinases, chaperones, and apoptotic mediators, are involved in the familial amyotrophic lateral sclerosis (ALS) model related to mutant Cu/Zn superoxide dismutase (SOD1) and sporadic ALS. We hypothesized that the endoplasmic reticulum-resident factor Derlin-1 plays a pivotal role in the regulation of misfolded proteins evoked by mutant SOD1. We show that Derlin-1 overexpression reduced mutant SOD1-induced cell toxicity and increased cell viability by suppressing the activation of the ER stress pathway factors: immunoglobulin-binding protein, activating transcription factor 6 p50, and C/EBP homologous protein. Interestingly, exogenous Derlin-1 resulted in a decrease in the amount of mutant SOD1, and a lesser decrease in that of wild-type SOD1, in transfected cells. Reduced SOD1 protein expression was observed in the microsomal fraction of wild-type and mutant SOD1 cells. Our results indicate that Derlin-1 regulates the turn over of SOD1 by promoting the proteasomal and autophagosomal degradation of SOD1 protein, but not by decreasing mutant SOD1 mRNA levels. Insights into the effects of Derlin-1 on mutant SOD1 may facilitate advancements in the treatment of motor neuron degeneration associated with ALS.