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Find video protocols related to scientific articles indexed in Pubmed.
PTK2 rs7460 and rs7843014 Polymorphisms and Exceptional Longevity: A Functional Replication Study.
Rejuvenation Res
PUBLISHED: 06-17-2014
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Abstract Focal adhesion is critical for cell survival. The focal adhesion kinase (FAK, or PTK2) is an important component of the human interactome and thus is a potential longevity-related protein. Here we studied the association between two PTK2 gene single-nucleotide polymorphisms (SNPs) (rs7843014, rs7460) and exceptional longevity (EL). In addition to gaining insight into their functionality by determining luciferase gene reporter activity, we studied the genotype/allele frequency of these two SNPs among three different cohorts: (1) Spanish centenarians (n=175, 100-111 years, 144 women) and healthy controls (n=355, 20-50 years, 284 women); (2) Italian centenarians (n=79, 100-104 years, 40 women) and controls (n=316, 29-50 years, 156 women); and (3) Japanese centenarians (n=742, 100-116 years, 623 women) and healthy controls (n=499, 23-59 years, 356 women). Both SNPs had functional significance, with the A allele up-regulating luciferase activity compared to the other allele (rs7460 T allele and rs7843014 C allele, respectively). The A allele of both SNPs was negatively associated with EL in the Spanish cohort (rs7460, odds ratio [OR] adjusted by sex=0.40, 95% confidence intervals [CI] 0.3, 0.6, p<0.001); rs7843014, OR=0.37, 95% CI 0.3, 0.5, p<0.001). The OR of being a centenarian if having the rs7460-TT genotype was 6.68 (95% CI 4.1, 10.8, p<0.001). The rs7843014 CC genotype was also positively associated with EL (OR=7.58, 95% CI 4.6, 12.3, p<0.001]. No association was, however, found for the Italian or Japanese cohorts. Thus, two genotypes of the FAK gene, rs7460 TT and rs7843014 CC, are possibly associated with lower gene expression and might favor the likelihood of reaching EL in the Spanish population. Further research is needed to unveil the mechanisms by which FAK expression could perhaps influence the rate of aging.
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The Q223R polymorphism in the leptin receptor associates with objectively measured light physical activity in free-living Japanese.
Physiol. Behav.
PUBLISHED: 02-06-2014
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Physical activity (PA) is associated with reductions in the risk of all-cause mortality and in the prevalence of cardiovascular disease and stroke. Nevertheless, a large proportion of the general population may not be sufficiently active. PA level has been reported to be influenced by genetic factors, and we investigated whether Q223R polymorphism in the leptin receptor (LEPR) gene was associated with PA level. A total of 556 Japanese adults aged 24-65years old participated in this cross-sectional study. The duration and intensity of PA were objectively evaluated by triaxial accelerometry. Q223R polymorphism was determined by the TaqMan method. The distribution of Q223R polymorphism was: QQ 0.7%, QR 22.6%, and RR 76.6%. The relation between the LEPR genotype and PA level was analyzed by ANCOVA with age and sex as covariates in the Q dominant genetic model. There were significant differences between LEPR genotypes and the time spent in light PA or inactive time. The subjects with RR genotype showed significantly shorter time spent in light PA (RR genotype: 559.4±102.9min/day, QQ/QR genotype: 579.9±103.1min/day) and longer inactive time (RR genotype: 815.5±107.5min/day, QQ/QR genotype: 792.3±107.7min/day) than the subjects with QQ/QR genotype (P<0.05). There were no such differences in the time spent in moderate or vigorous PA. These results suggest that the variety of PA level, especially spontaneous PA in humans, is partly caused by diversity in the LEPR gene.
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ApoE gene and exceptional longevity: Insights from three independent cohorts.
Exp. Gerontol.
PUBLISHED: 02-03-2014
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The ApoE gene is associated with the risk of Alzheimer or cardiovascular disease but its influence on exceptional longevity (EL) is uncertain. Our primary purpose was to determine, using a case-control design, if the ApoE gene is associated with EL. We compared ApoE allele/genotype frequencies among the following cohorts: cases (centenarians, most with 1+ major disease condition; n=163, 100-111years) and healthy controls (n=1039, 20-85years) from Spain; disease-free cases (centenarians; n=79, 100-104years) and healthy controls (n=597, age 27-81years) from Italy; and cases (centenarians and semi-supercentenarians, most with 1+ major disease condition; n=729, 100-116years) and healthy controls (n=498, 23-59years) from Japan. Our main findings were twofold. First, the ?4-allele was negatively associated with EL in the three cohorts, with the following odds ratio (OR) values (adjusted by sex) having been found: 0.55 (95% confidence interval (CI): 0.33, 0.94), P=0.030 (Spain); 0.41 (95%CI: 0.18, 0.99), P=0.05 (Italy); and 0.35 (95%CI: 0.26, 0.57), P<0.001 (Japan). Second, although no association was found in the Spanish cohort (OR=1.42 (95%CI: 0.89, 2.26), P=0.145), the ?2-allele was positively associated with EL in the Italian (OR=2.14 (95%CI: 1.18, 3.45), P=0.01) and Japanese subjects (OR=1.81 (95%CI: 1.25, 2.63), P=0.002). Notwithstanding the limitations of case-control designs, our data suggest that the ApoE might be a candidate to influence EL. The ?4-allele appears to decrease the likelihood of reaching EL among individuals of different ethnic/geographic origins. An additional, novel finding of our study was that the ?2-allele might favor EL, at least in the Italian and Japanese cohorts.
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Genomics of Elite Sporting Performance: What little We Know and Necessary Advances.
Adv. Genet.
PUBLISHED: 11-23-2013
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Numerous reports of genetic associations with performance- and injury-related phenotypes have been published over the past three decades; these studies have employed primarily the candidate gene approach to identify genes that associate with elite performance or with variation in performance-and/or injury-related traits. Although generally with small effect sizes and heavily prone to type I statistic error, the number of candidate genetic variants that can potentially explain elite athletic status, injury predisposition, or indeed response to training will be much higher than that examined by numerous biotechnology companies. Priority should therefore be given to applying whole genome technology to sufficiently large study cohorts of world-class athletes with adequately measured phenotypes where it is possible to increase statistical power. Some of the elite athlete cohorts described in the literature might suffice, and collectively, these cohorts could be used for replication purposes. Genome-wide association studies are ongoing in some of these cohorts (i.e., Genathlete, Russian, Spanish, Japanese, United States, and Jamaican cohorts), and preliminary findings include the identification of one single nucleotide polymorphism (SNP; among more than a million SNPs analyzed) that associates with sprint performance in Japanese, American (i.e., African American), and Jamaican cohorts with a combined effect size of ~2.6 (P-value <5×10(-7)) and good concordance with endurance performance between select cohorts. Further replications of these signals in independent cohorts will be required, and any replicated SNPs will be taken forward for fine-mapping/targeted resequencing and functional studies to uncover the underlying biological mechanisms. Only after this lengthy and costly process will the true potential of genetic testing in sport be determined.
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Association analysis of ACE and ACTN3 in elite Caucasian and East Asian swimmers.
Med Sci Sports Exerc
PUBLISHED: 06-19-2013
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Polymorphic variation in the angiotensin-converting enzyme (ACE) and ?-actinin-3 (ACTN3) genes has been reported to be associated with endurance and/or power-related human performance. Our aim was to investigate whether polymorphisms in ACE and ACTN3 are associated with elite swimmer status in Caucasian and East Asian populations.
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Comprehensive analysis of common and rare mitochondrial DNA variants in elite Japanese athletes: a case-control study.
J. Hum. Genet.
PUBLISHED: 06-10-2013
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The purpose of the present study was to identify mitochondrial DNA (mtDNA) polymorphisms and rare variants that associate with elite Japanese athletic status. Subjects comprised 185 elite Japanese athletes who had represented Japan at international competitions (that is, 100 endurance/middle-power athletes: EMA; 85 sprint/power athletes: SPA) and 672 Japanese controls (CON). The entire mtDNA sequences (16?569?bp) were analyzed by direct sequencing. Nucleotide variants were detected at 1488 sites in the 857 entire mtDNA sequences. A total of 311 variants were polymorphisms (minor allele frequency?1% in CON), and the frequencies of these polymorphisms were compared among the three groups. The EMA displayed excess of seven polymorphisms, including subhaplogroup D4e2- and D4g-specific polymorphisms, compared with CON (P<0.05), whereas SPA displayed excess of three polymorphisms and dearth of nine polymorphisms, including haplogroup G- and subhaplogroup G2a-specific polymorphisms, compared with CON (P<0.05). The frequencies of 10 polymorphisms, including haplogroup G- and subhaplogroup G2a-specific polymorphisms, were different between EMA and SPA (P<0.05): although none of these polymorphisms differed significantly between groups after correcting for multiple comparison (false discovery rate q-value?0.05). The number of rare variants in the 12S ribosomal RNA and NADH dehydrogenase subunit I genes were also higher in SPA than in CON (P<0.05). Analysis of the entire mtDNA of elite Japanese athletes revealed several haplogroup- and subhaplogroup-specific polymorphisms to be potentially associated with elite Japanese athletic status.
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Genomics of elite sporting performance: what little we know and necessary advances.
Br J Sports Med
PUBLISHED: 04-30-2013
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Numerous reports of genetic associations with performance-related phenotypes have been published over the past three decades but there has been limited progress in discovering and characterising the genetic contribution to elite/world-class performance, mainly owing to few coordinated research efforts involving major funding initiatives/consortia and the use primarily of the candidate gene analysis approach. It is timely that exercise genomics research has moved into a new era utilising well-phenotyped, large cohorts and genome-wide technologies--approaches that have begun to elucidate the genetic basis of other complex traits/diseases. This review summarises the most recent and significant findings from sports genetics and explores future trends and possibilities.
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The rs1333049 polymorphism on locus 9p21.3 and extreme longevity in Spanish and Japanese cohorts.
Age (Dordr)
PUBLISHED: 04-22-2013
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The rs1333049 (G/C) polymorphism located on chromosome 9p21.3 is a candidate to influence extreme longevity owing to its association with age-related diseases, notably coronary artery disease (CAD). We compared allele/genotype distributions of rs1333049 in cases (centenarians) and controls (younger adults, without (healthy) or with CAD) in two independent cohorts: Spanish (centenarians: n?=?152, 128 women, 100-111 years; healthy controls: n?=?343, 212 women, age <50 years; CAD controls: n?=?98, 32 women, age ?65 years) and Japanese (centenarians: n?=?742, 623 women, 100-115 years; healthy controls: n?=?920, 511 women, < 60 years; CAD controls: n?=?395, 45 women, age ?65 years). The frequency of the "risk" C-allele tended to be lower in Spanish centenarians (47.0 %) than in their healthy (52.9 %, P?=?0.088) or CAD controls (55.1 %, P?=?0.078), and significant differences were found in genotype distributions (P?=?0.034 and P?=?0.045), with a higher frequency of the GG genotype in cases than in both healthy and CAD controls as well as a lower proportion of the CG genotype compared with healthy controls. In the Japanese cohort, the main finding was that the frequency of the C-allele did not differ between centenarians (46.4 %) and healthy controls (47.3 %, P?=?0.602), but it was significantly lower in the former than in CAD controls (57.2 %, P?
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Exome sequencing of senescence-accelerated mice (SAM) reveals deleterious mutations in degenerative disease-causing genes.
BMC Genomics
PUBLISHED: 03-19-2013
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Senescence-accelerated mice (SAM) are a series of mouse strains originally derived from unexpected crosses between AKR/J and unknown mice, from which phenotypically distinct senescence-prone (SAMP) and -resistant (SAMR) inbred strains were subsequently established. Although SAMP strains have been widely used for aging research focusing on their short life spans and various age-related phenotypes, such as immune dysfunction, osteoporosis, and brain atrophy, the responsible gene mutations have not yet been fully elucidated.
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Association of the formiminotransferase N-terminal sub-domain containing gene and thrombospondin, type 1, domain-containing 7A gene with the prevalence of vertebral fracture in 2427 consecutive autopsy cases.
J. Hum. Genet.
PUBLISHED: 01-10-2013
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We previously reported 2 osteoporosis-susceptibility genes--formiminotransferase N-terminal sub-domain containing gene (FONG) and thrombospondin, type 1, domain-containing 7A (THSD7A)--in which we identified two common single-nucleotide polymorphisms, rs7605378 (FONG) and rs12673692 (THSD7A). The former was associated with a predisposition to osteoporosis and the latter with bone mineral density. To further elucidate the importance of these polymorphisms in the pathogenesis of osteoporosis, we examined their association with the incidence of vertebral fracture. DNA extracted from the renal cortex of 2427 consecutive Japanese autopsies (1331 men, mean age: 79 years; 1096 women, mean age: 82 years) were examined in this study. The presence or absence of vertebral fracture during each subjects lifetime was determined by a thorough examination of the clinical records, as well as autopsy reports. After adjustments for sex and age at autopsy, logistic regression analysis revealed that homozygotes for the risk alleles of rs7605378 (A-allele) or rs12673629 (A-allele) possess an increased risk of vertebral fracture. The subjects simultaneously homozygous for both the risk alleles of rs7605378 (AA genotype) and rs12673629 (AA genotype) showed significantly higher risk of vertebral fracture (odds ratio 2.401, 95% confidence interval 1.305-4.416, P = 0.0048) than those who had at least one non-risk allele of either rs7605378 (AC/CC genotypes) or rs12673629 (AG/GG genotypes). The results suggest that Japanese subjects homozygous for the risk alleles of rs7605378 and rs12673629 have a higher risk of vertebral fracture.
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Association of 29C>T polymorphism in the transforming growth factor-?1 gene with lean body mass in community-dwelling Japanese population.
Geriatr Gerontol Int
PUBLISHED: 11-08-2011
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Sarcopenia is the significant degenerative loss of skeletal muscle mass and strength associated with aging, and it is one of the components of frailty. We previously reported an association between the 29C>T polymorphism in the transforming growth factor-?1 gene (rs1800470) and the prevalence of vertebral fractures in subjects with postmenopausal osteoporosis. The association was not attributable to bone mineral density, which suggests that polymorphism influences some aspects of bone quality that affects strength and/or frailty rather than bone strength itself. Thus, we examined the relationship between genetic polymorphism and lean body mass in a Japanese population.
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Mitochondrial haplogroups A and M7a confer a genetic risk for coronary atherosclerosis in the Japanese elderly: an autopsy study of 1,536 patients.
J. Atheroscler. Thromb.
PUBLISHED: 11-19-2010
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We previously reported significant associations between mitochondrial single nucleotide polymorphisms (mtSNPs) and myocardial infarction, atherothrombotic cerebral infarction, metabolic syndrome and type 2 diabetes. Here, we assessed the hypothesis that mtSNPs may confer a risk for atherosclerosis, the most important intermediate phenotype of ischemic cardiovascular events.
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FTO genotype and adiposity in children: physical activity levels influence the effect of the risk genotype in adolescent males.
Eur. J. Hum. Genet.
PUBLISHED: 08-18-2010
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Studies of the fat mass and obesity-associated (FTO) gene provide compelling evidence of genetic variation in the general population that influences fat levels and obesity risk. Studies of the interaction between genetic and environmental factors such as physical activity (PA) will promote the understanding of how lifestyle can modulate genetic contributions to obesity. In this study, we investigated the effect of FTO genotype, and interactions with PA or energy intake, in young children and adolescents. In all, 1-5-year-old children from the Growth, Exercise and Nutrition Epidemiological Study in preSchoolers (GENESIS) study (N=1980) and 11-18-year-old Greek adolescents (N=949) were measured for adiposity-related phenotypes and genotyped at the FTO single-nucleotide polymorphism (SNP) marker, rs17817449. Adolescents were classified as physically active or inactive based on self-reported levels of PA. In adolescents, FTO genotype influenced weight (P=0.001) and BMI (P=0.007). There was also a significant SNP(*)PA(*)gender interaction (P=0.028) on BMI, which reflected the association between FTO genotype and BMI in males (P=0.016), but not females (P=0.15), and significant SNP(*)PA interaction in males (P=0.007), but not females (P=0.74). The FTO genotype effect was more pronounced in inactive than active males. Inactive males homozygous for the G allele had a mean BMI 3?kg/m(2) higher than T carriers (P=0.008). In the GENESIS study, no significant association between FTO genotype and adiposity was found. The present findings highlight PA as an important factor modifying the effect of FTO genotype.
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Metabolic analysis of 13C-labeled pyruvate for noninvasive assessment of mitochondrial function.
Ann. N. Y. Acad. Sci.
PUBLISHED: 07-24-2010
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Mitochondria may play important roles in metabolic diseases, neurodegeneration, and aging. Therefore, noninvasive methods to assess mitochondrial metabolic function in humans are urgently needed. We demonstrated that the (13)C-breath test using [1-(13)C] acetate and [1-(13)C] pyruvate holds great potential for assessing the metabolic status in mitochondria. The (13)C-breath test allows us to assess dynamic metabolic pathways noninvasively within 60 min. This test will not only facilitate clinical evaluation of patients but also provide huge opportunities for further understanding of these conditions. The potential of the (13)C-breath test using (13)C-labeled pyruvate in humans cannot be overemphasized.
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Mitochondrial haplogroups associated with lifestyle-related diseases and longevity in the Japanese population.
Geriatr Gerontol Int
PUBLISHED: 07-02-2010
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Recently published results on the association between metabolic syndrome, type 2 diabetes, myocardial infarction or atherothrombotic cerebral infarction and Japanese major haplogroups based on the comprehensive analysis of mitochondrial genome polymorphisms (mtSNP) in the coding region of human mitochondrial DNA (mtDNA), and longevity-related haplogroups are described in the present review. Our aim was to provide information that would allow us to predict the genetic risk for lifestyle-related diseases and thereby contribute to the primary prevention of these conditions. The mitochondrial genome variation is so large that a given haplogroup might consist of various subhaplogroups carrying unique and presumably functional mtSNP. The frequency of each subhaplogroup is sometimes only a few percent. Therefore, large-scale association study is necessary for elucidating the impact of each subhaplogroup on the susceptibility to various common diseases.
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Mitochondrial haplogroups associated with elite Japanese athlete status.
Br J Sports Med
PUBLISHED: 06-15-2010
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It has been hypothesised that certain mitochondrial haplogroups, which are defined by the presence of a characteristic cluster of tightly linked mitochondrial DNA polymorphisms, would be associated with elite Japanese athlete status. To examine this hypothesis, the frequencies of mitochondrial haplogroups found in elite Japanese athletes were compared with those in the general Japanese population.
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Macrophages that survive hyperoxia exposure have higher superoxide dismutase activities in their mitochondria.
Adv. Exp. Med. Biol.
PUBLISHED: 03-06-2010
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Prolonged exposure to hyperoxia, which is routinely used in patients with severe respiratory failure, leads to the generation of excessive reactive oxygen species, resulting in lung injury. In the present study, we focused on macrophages and their survival, superoxide dismutase (SOD) activity in mitochondria (Mn-SOD activity), and mitochondrial DNA (mtDNA) mutation after exposure to hyperoxia. Macrophages were cultured under two different conditions: normoxia and intermittent hyperoxia. The number of cells exposed to intermittent hyperoxia for 3 weeks significantly decreased, compared with the number of cells exposed to normoxia. The Mn-SOD activity of the cells that survived intermittent hyperoxia exposure was significantly higher than that of the cells exposed to normoxia. Direct sequencing and a PCR-RFLP assay did not provide any evidence of mutation in the cells that survived intermittent hyperoxia exposure. In conclusion, an increase in the antioxidative activity of mitochondria is important for the survival of macrophages exposed to hyperoxia, and the increased activity level possibly enhances protective effects against mtDNA mutations in surviving cells.
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Cooperative effect of serum 25-hydroxyvitamin D concentration and a polymorphism of transforming growth factor-beta1 gene on the prevalence of vertebral fractures in postmenopausal osteoporosis.
J. Bone Miner. Metab.
PUBLISHED: 01-07-2010
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A T869-->C polymorphism of the transforming growth factor-beta1 (TGF-beta1) gene is reported to be associated with genetic susceptibility to both osteoporosis and vertebral fractures. A low serum 25-hydroxyvitamin D [25(OH)D] level is known to be associated with a higher risk for hip fracture. This study aimed to assess a possible cooperative effect of the gene polymorphism and vitamin D status on vertebral fracture risk. The prevalence of vertebral fracture in 168 postmenopausal female patients with osteoporosis was analyzed, and its association with the TGF-beta1 gene polymorphism and serum 25(OH)D concentration was assessed cross-sectionally. The fracture prevalence increased according to the rank order of the TGF-beta1 genotypes CC < CT < TT, as expected. A significant difference was found not only between the CC and TT genotypes (P = 0.005) but also between the CC and CT genotypes (P < 0.05) when the patients with serum 25(OH)D of more than the median value [22 ng/ml (55 nmol/l)] were analyzed. On the other hand, when those with serum 25(OH)D of less than the median value were analyzed, the protective effect of the C allele against the fracture was blunted; statistical significance in the difference of the fracture prevalence was lost between the CC genotype and the other genotypes. These data suggest that vitamin D fulfillment is prerequisite for the TGF-beta1 genotype in exerting its full effect on the fracture prevalence.
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Pyruvate therapy for Leigh syndrome due to cytochrome c oxidase deficiency.
Biochim. Biophys. Acta
PUBLISHED: 05-15-2009
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Recently we proposed the therapeutic potential of pyruvate therapy for mitochondrial diseases. Leigh syndrome is a progressive neurodegenerative disorder ascribed to either mitochondrial or nuclear DNA mutations.
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Mitochondrial haplogroups associated with elite Kenyan athlete status.
Med Sci Sports Exerc
PUBLISHED: 05-14-2009
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The maternal inheritance of mitochondrial DNA (mtDNA) has enabled construction of detailed phylogenies. Analysis of key polymorphisms from these phylogenies allows mtDNA to be assigned to haplogroups, which have been associated with elite endurance performance.
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Analysis of mitochondrial DNA variants in Japanese patients with schizophrenia.
Mitochondrion
PUBLISHED: 01-30-2009
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To test the hypothesis that mitochondrial DNA (mtDNA) variants contribute to the susceptibility to schizophrenia, we sequenced the entire mtDNAs from 93 Japanese schizophrenic patients. Three non-synonymous homoplasmic variants in subunit six of the ATP synthase (MT-ATP6) gene that were detected only in patients but not in controls were suggested to be slightly deleterious, because (1) their original amino acid residues (AA) were highly conserved and (2) the physicochemical differences between the original and altered AA were relatively high. In addition, we detected three novel heteroplasmic variants that were potentially pathogenic. Although functional analysis is needed, rare variants in the mtDNA may convey susceptibility to schizophrenia.
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Identification of CELSR1 as a susceptibility gene for ischemic stroke in Japanese individuals by a genome-wide association study.
Atherosclerosis
PUBLISHED: 01-22-2009
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We have performed a genome-wide association study (GWAS) to identify genetic variants that confer susceptibility to ischemic stroke.
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Extended screening for major mitochondrial DNA point mutations in patients with hereditary hearing loss.
J. Hum. Genet.
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Hearing loss (HL) is the most common sensory disorder in humans. Many patients with mitochondrial diseases have sensorineural HL (SNHL). The HL of these patients manifests as a consequence of either syndromic or nonsyndromic mitochondrial diseases. Furthermore, the phenotypes vary among patients even if they are carrying the same mutation. Therefore, these features make it necessary to analyze every presumed mutation in patients with hereditary HL, but the extensive analysis of various mutations is laborious. We analyzed 373 patients with suspected hereditary HL by using an extended suspension-array screening system for major mitochondrial DNA (mtDNA) mutations, which can detect 32 other mtDNA mutations in addition to the previously analyzed 29 mutations. In the present study, we detected 2 different mtDNA mutations among these 373 patients; m.7444G>A in the MT-CO1 gene and m.7472insC in the MT-TS1 gene in 1 patient (0.3%) for each. As these two patients had no clinical features other than HL, they had not been suspected of having mtDNA mutations. This extended screening system together with the previous one is useful for the genetic diagnosis and epidemiological study of both syndromic and nonsyndromic HL.
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An alternative model for the early peopling of southern South America revealed by analyses of three mitochondrial DNA haplogroups.
PLoS ONE
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After several years of research, there is now a consensus that America was populated from Asia through Beringia, probably at the end of the Pleistocene. But many details such as the timing, route(s), and origin of the first settlers remain uncertain. In the last decade genetic evidence has taken on a major role in elucidating the peopling of the Americas. To study the early peopling of South America, we sequenced the control region of mitochondrial DNA from 300 individuals belonging to indigenous populations of Chile and Argentina, and also obtained seven complete mitochondrial DNA sequences. We identified two novel mtDNA monophyletic clades, preliminarily designated B2l and C1b13, which together with the recently described D1g sub-haplogroup have locally high frequencies and are basically restricted to populations from the extreme south of South America. The estimated ages of D1g and B2l, about ~15,000 years BP, together with their similar population dynamics and the high haplotype diversity shown by the networks, suggests that they probably appeared soon after the arrival of the first settlers and agrees with the dating of the earliest archaeological sites in South America (Monte Verde, Chile, 14,500 BP). One further sub-haplogroup, D4h3a5, appears to be restricted to Fuegian-Patagonian populations and reinforces our hypothesis of the continuity of the current Patagonian populations with the initial founders. Our results indicate that the extant native populations inhabiting South Chile and Argentina are a group which had a common origin, and suggest a population break between the extreme south of South America and the more northern part of the continent. Thus the early colonization process was not just an expansion from north to south, but also included movements across the Andes.
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Mitochondrial DNA haplogroup associated with hereditary hearing loss in a Japanese population.
Acta Otolaryngol.
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Haplogroup D4b, especially subhaplogroup D4b2, may be one of the modifiers associated with the phenotypic expression of hereditary hearing loss (HL).
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The mitochondrial T1095C mutation increases gentamicin-mediated apoptosis.
Mitochondrion
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We have previously reported a heteroplasmic mtDNA mutation (T1095C) in the 12SrRNA gene of an Italian family with features of maternally-inherited parkinsonism, antibiotic-mediated deafness and peripheral neuropathy. In the present study, we demonstrate that a transmitochondrial cybrid line derived from the proband of this family shows selective depletion of mitochondrial glutathione and decreases in the activity of complex II/III. Moreover, when exposed to an aminoglycoside antibiotic these cells responded with a ten-fold increase in the number of apoptotic cells compared to controls. These results support a pathogenic role for the T1095C mutation and indicate that the mutation increases the risk for aminoglycoside-induced toxicity.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.