The restriction endonuclease SmaI has been used for the diagnosis of neurogenic muscle weakness, ataxia and retinitis pigmentosa disease or Leigh’s disease, caused by the Mt8993T→G mutation which results in a Leu156Arg replacement that blocks proton translocation activity of subunit a of F₀F₁-ATPase. Our ultimate goal is to apply SmaI to gene therapy for this disease, because the mutant mitochondrial DNA (mtDNA) coexists with the wild-type mtDNA (heteroplasmy), and because only the mutant mtDNA, but not the wild-type mtDNA, is selectively restricted by the enzyme. For this purpose, we transiently expressed the SmaI gene fused to a mitochondrial targeting sequence in cybrids carrying the mutant mtDNA. Here, we demonstrate that mitochondria targeted by the SmaI enzyme showed specific elimination of the mutant mtDNA. This elimination was followed with repopulation by the wild-type mtDNA, resulting in restoration of both the normal intracellular ATP level and normal mitochondrial membrane potential. Furthermore, in vivo electroporation of the plasmids expressing mitochondrion-targeted EcoRI induced a decrease in cytochrome c oxidase activity in hamster skeletal muscles while causing no degenerative changes in nuclei. Delivery of restriction enzymes into mitochondria is a novel strategy for gene therapy of a special form of mitochondrial diseases.

FSGS may belong to the spectrum of renal involvement in A3243G mtDNA mutation in humans. Severely injured podocytic changes containing abnormal mitochondria may explain the pathogenesis of FSGS in association with the A3243G mtDNA mutation.

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Human coronavirus NL63 recently found in The Netherlands has been detected in Japan with a reverse transcription-polymerase chain reaction technique in clinical specimens from pediatric patients with respiratory symptoms. Of 419 specimens that were negative for common respiratory viruses, 5 were positive for human coronavirus NL63, and these specimens were all collected in the first 3 months of 2003.

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Fabry disease is an X-linked recessive inborn metabolic disorder caused by a deficiency of the lysosomal enzyme α-galactosidase A (EC 3.2. throughout the 7 exons of the α-galactosidase A gene (GLA). Mutation hotspots for Fabry disease do not exist. We examined 62 Fabry patients in Japan and found 24 GLA mutations, including 11 novel ones. A potential treatment reported for Fabry disease is active site specific chaperone (ASSC) therapy using 1-deoxygalactonojirimycin (DGJ), an inhibitor of α-galactosidase A, at subinhibitory concentrations. We transfected COS-7 cells with the 24 mutant GLAs and analyzed the α-galactosidase A activities. We then treated the transfected COS-7 cells with DGJ and analyzed its effect on the mutant enzyme activities. The activity of 11 missense mutants increased significantly with DGJ. Although ASSC therapy is useful only for misfolding mutants and therefore not applicable to all cases, it may be useful for treating many Japanese patients with Fabry disease. © 2007 Wiley-Liss, Inc.KEY WORDS: α-galactosidase A; GLA; lysosomal storage disease; 1-deoxygalactonojirimycin; chaperone therapy INTRODUCTIONFabry disease (FD; MIM# 301500) is a pan-ethnic, X-linked, lysosomal storage disorder caused by a deficiency in the lysosomal enzyme α-galactosidase A (EC 3.2.1.22) (Brady et al., 1967). Human α-galactosidase A is a homodimeric glycoprotein with three N-linked oligosaccharide chains on each subunit. Enzyme deficiency results in a systemic lysosomal accumulation of glycolipids, primarily globotriosylceramide (Gb3), in the vascular endothelium and other tissues. In the classical form of the disease, the patient develops angiokeratoma, hypohidrosis, and episodic pain crises in the extremities during childhood or adolescence. With advancing age, the morbidity of renal failure, cardiac disease, and early onset of stroke increases. The severity of the clinical manifestations depends on the amount of residual α-galactosidase A activity. Hemizygous male patients with no or very low α-galactosidase A activity usually have severe clinical symptoms and die as young adults. Heterozygous female Fabry patients exhibit a wide range of severity, from a virtually symptom-free course (Marguery et al., 1993) to one comparable to that of their male counterparts (Whybra et al., 2001), although they usually have no symptoms or very mild manifestations.We examined Fabry patients in Japan and sequenced the patients' α-galactosidase A gene (GLA) (MIM# 300644). To analyze the mutant α-galactosidase A activities, we transfected COS-7 cells with the mutant GLAs. In addition, since 1-deoxygalactonojirimycin (DGJ) stabilizes the α-galactosidase A conformation and improves its stability (Asano et al., 2000;Ishii et al., 2000;Yam et al., 2006), we added DGJ to the incubation medium and examined its effect on the mutant α-galactosidase A activities. MATERIALS AND METHODS PatientsWe examined 62 Fabry patients from 31 unrelated families. Diagnosis was based on reduced or absent α-galactosidase A activity and typical signs an...

Recent evidence suggests possible linkage between diabetes mellitus and mitochondrial gene mutation. We surveyed mitochondrial tRNA(LEU(UUR)) (3243) mutation in 7 mitochondrial encephalomyopathy, lactic acidosis and stroke-like episode (MELAS) families and identified 24 mutated subjects (7 MELAS probands and 17 non-MELAS relatives) as well as 11 non-mutant family members. An OGTT in the 24 mutant relatives revealed 14 diabetic subjects, 3 with impaired glucose tolerance and 7 with normal glucose tolerance and all non-mutant family members as having normal glucose tolerance. Insulinogenic index was significantly reduced in the mutant diabetic subjects and those with impaired and normal glucose tolerance in comparison with the normal control subjects and the non-mutant members. Urinary 24-h C-peptide immunoreactivity excretion was markedly reduced in the mutant diabetic subjects and those with normal and impaired glucose tolerance, compared with the control subjects and the non-mutant family members. Plasma C-peptide immunoreactivity 6 min after glucagon injection was markedly reduced in the mutant diabetic subjects and those with normal and impaired glucose tolerance compared with the control subjects and the non-mutant family members. Si, an index of insulin sensitivity of the four mutant subjects was within normal range. Islet cell antibodies were negative in sera of eight mutated diabetic subjects, 2 and 6 with impaired and normal glucose tolerance, respectively. Diabetic retinopathy and nephropathy were demonstrated in 7 (50%) and 12 (85.7%) of 14 mutant diabetic subjects, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Background: Bronchial asthma is a chronic airway disorder characterized by bronchial inflammation. Oxidative stress is a key component of inflammation. Glutathione S-transferase P1 (GSTP1), the abundant isoform of glutathione S-transferases (GSTs) in lung epithelium, plays a key role in cellular protection against oxidative stress. Several studies have shown that the GSTP1 geneis involved in the pathogenesis of asthma and a gene-gene interaction may occur within the GST gene superfamily. Methods: We screened single-nucleotide polymorphisms (SNPs) at the GSTP1 locus and performed an association study in the Japanese population using two independent case-control groups (group 1: 391 pediatric patients with asthma, 462 adult patients with asthma, and 639 controls, and group 2: 115 pediatric patients with asthma and 184 controls). The effect of GSTM1 null/present genotype on the association between GSTP1 Ile105Val and asthma was also investigated. Results: We identified 20 SNPs at this locus and found this region consisted of one linkage disequilibrium block represented by four SNPs (tag SNPs). The association between the Ile105Val polymorphism in the GSTP1 gene and childhood asthma was significant in both groups (p = 0.047 in group 1, and p = 0.021 in group 2). This association was only significant in patients with GSTM1-positive genotype in both groups (group 1: GSTM1 present p = 0.013 and GSTM1 null p = 0.925, and group 2: GSTM1 present p = 0.015 and GSTM1 null p = 0.362). Conclusions: These findings suggest that the GSTP1 gene is a childhood asthma susceptible gene, and the GSTM1 gene is a modifier gene of GSTP1 for the risk of childhood asthma in the Japanese population.