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Sample records for cag repeat length

  1. Discrepancies in reporting the CAG repeat lengths for Huntington's disease

    DEFF Research Database (Denmark)

    Quarrell, Oliver W; Handley, Olivia; O'Donovan, Kirsty

    2011-01-01

    Huntington's disease results from a CAG repeat expansion within the Huntingtin gene; this is measured routinely in diagnostic laboratories. The European Huntington's Disease Network REGISTRY project centrally measures CAG repeat lengths on fresh samples; these were compared with the original...

  2. Age, CAG repeat length, and clinical progression in Huntington's disease.

    Science.gov (United States)

    Rosenblatt, Adam; Kumar, Brahma V; Mo, Alisa; Welsh, Claire S; Margolis, Russell L; Ross, Christopher A

    2012-02-01

    The objective of this study was to further explore the effect of CAG repeat length on the rate of clinical progression in patients with Huntington's disease. The dataset included records for 569 subjects followed prospectively at the Baltimore Huntington's Disease Center. Participants were seen for a mean of 7.1 visits, with a mean follow-up of 8.2 years. Subjects were evaluated using the Quantified Neurologic Examination and its Motor Impairment subscale, the Mini-Mental State Examination, and the Huntington's disease Activities of Daily Living Scale. By itself, CAG repeat length showed a statistically significant but small effect on the progression of all clinical measures. Contrary to our previous expectations, controlling for age of onset increased the correlation between CAG repeat length and progression of all variables by 69% to 159%. Graphical models further supported the idea that individuals with smaller triplet expansions experience a more gradual decline. CAG repeat length becomes an important determinant of clinical prognosis when accounting for age of onset. This suggests that the aging process itself influences clinical outcomes in Huntington's disease. Inconsistent results in prior studies examining CAG repeat length and progression may indeed reflect a lack of age adjustment.

  3. Linking SNPs to CAG repeat length in Huntington's disease patients.

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    Liu, Wanzhao; Kennington, Lori A; Rosas, H Diana; Hersch, Steven; Cha, Jang-Ho; Zamore, Phillip D; Aronin, Neil

    2008-11-01

    Allele-specific silencing using small interfering RNAs targeting heterozygous single-nucleotide polymorphisms (SNPs) is a promising therapy for human trinucleotide repeat diseases such as Huntington's disease. Linking SNP identities to the two HTT alleles, normal and disease-causing, is a prerequisite for allele-specific RNA interference. Here we describe a method, SNP linkage by circularization (SLiC), to identify linkage between CAG repeat length and nucleotide identity of heterozygous SNPs using Huntington's disease patient peripheral blood samples.

  4. The relationship between anogenital distance and the androgen receptor CAG repeat length

    OpenAIRE

    Eisenberg, Michael L.; Hsieh, Tung-Chin; Pastuszak, Alexander W; McIntyre, Matthew G.; Walters, Rustin C; Lamb, Dolores J.; Lipshultz, Larry I

    2013-01-01

    Anogenital distance (AGD) is used to define degree of virilization of genital development, with shorter length being associated with feminization and male infertility. The first exon of the androgen receptor (AR) consists of a polymorphic sequence of cytosine–adenine–guanine (CAG) repeats, with longer CAG repeat lengths being associated with decreased receptor function. We sought to determine if there is an association between AGD and AR CAG repeat length. A cross-sectional, prospective cohor...

  5. The relationship between anogenital distance and the androgen receptor CAG repeat length

    Institute of Scientific and Technical Information of China (English)

    Michael L Eisenberg; Tung-Chin Hsieh; Alexander W Pastuszak; Matthew G McIntyre; Rustin C Walters; Dolores J Lamb; Larry I Lipshultz

    2013-01-01

    Anogenital distance (AGD) is used to define degree of virilization of genital development,with shorter length being associated with feminization and male infertility.The first exon of the androgen receptor (AR) consists of a polymorphic sequence of cytosine-adenine-guanine (CAG) repeats,with longer CAG repeat lengths being associated with decreased receptor function.We sought to determine if there is an association between AGD and AR CAG repeat length.A cross-sectional,prospective cohort of men evaluated at a urology clinic at a single institution was recruited.AGD (the distance from the posterior scrotum to the anal verge) and penile length (PL) were measured.Sanger DNA sequence analysis was used to define CAG repeat length.AGD and CAG repeat lengths in 195 men were determined.On unadjusted analysis,there was no linear relationship between CAG repeat length and PL (P=0.17) or AGD (P=0.31).However,on sub-population analyses,those men with longer CAG repeat lengths (>26) had significantly shorter AGDs compared to men with shorter CAG repeat lengths.For example,the mean AGD was 41.9 vs.32.4 mm with a CAG repeat length ≤ 26 vs.>26 (P=0.01).In addition,when stratifying the cohort based on AGD,those with AGD less than the median (i.e.40 mm) had a longer CAG repeat length compared to men with an AGD >40 mm (P=0.02).In summary,no linear relationship was found between AGD and AR CAG repeat length overall.

  6. The relationship between anogenital distance and the androgen receptor CAG repeat length.

    Science.gov (United States)

    Eisenberg, Michael L; Hsieh, Tung-Chin; Pastuszak, Alexander W; McIntyre, Matthew G; Walters, Rustin C; Lamb, Dolores J; Lipshultz, Larry I

    2013-03-01

    Anogenital distance (AGD) is used to define degree of virilization of genital development, with shorter length being associated with feminization and male infertility. The first exon of the androgen receptor (AR) consists of a polymorphic sequence of cytosine-adenine-guanine (CAG) repeats, with longer CAG repeat lengths being associated with decreased receptor function. We sought to determine if there is an association between AGD and AR CAG repeat length. A cross-sectional, prospective cohort of men evaluated at a urology clinic at a single institution was recruited. AGD (the distance from the posterior scrotum to the anal verge) and penile length (PL) were measured. Sanger DNA sequence analysis was used to define CAG repeat length. AGD and CAG repeat lengths in 195 men were determined. On unadjusted analysis, there was no linear relationship between CAG repeat length and PL (P=0.17) or AGD (P=0.31). However, on sub-population analyses, those men with longer CAG repeat lengths (>26) had significantly shorter AGDs compared to men with shorter CAG repeat lengths. For example, the mean AGD was 41.9 vs. 32.4 mm with a CAG repeat length ≤26 vs. >26 (P=0.01). In addition, when stratifying the cohort based on AGD, those with AGD less than the median (i.e. 40 mm) had a longer CAG repeat length compared to men with an AGD >40 mm (P=0.02). In summary, no linear relationship was found between AGD and AR CAG repeat length overall.

  7. Discrepancies in reporting the CAG repeat lengths for Huntington's disease.

    Science.gov (United States)

    Quarrell, Oliver W; Handley, Olivia; O'Donovan, Kirsty; Dumoulin, Christine; Ramos-Arroyo, Maria; Biunno, Ida; Bauer, Peter; Kline, Margaret; Landwehrmeyer, G Bernhard

    2012-01-01

    Huntington's disease results from a CAG repeat expansion within the Huntingtin gene; this is measured routinely in diagnostic laboratories. The European Huntington's Disease Network REGISTRY project centrally measures CAG repeat lengths on fresh samples; these were compared with the original results from 121 laboratories across 15 countries. We report on 1326 duplicate results; a discrepancy in reporting the upper allele occurred in 51% of cases, this reduced to 13.3% and 9.7% when we applied acceptable measurement errors proposed by the American College of Medical Genetics and the Draft European Best Practice Guidelines, respectively. Duplicate results were available for 1250 lower alleles; discrepancies occurred in 40% of cases. Clinically significant discrepancies occurred in 4.0% of cases with a potential unexplained misdiagnosis rate of 0.3%. There was considerable variation in the discrepancy rate among 10 of the countries participating in this study. Out of 1326 samples, 348 were re-analysed by an accredited diagnostic laboratory, based in Germany, with concordance rates of 93% and 94% for the upper and lower alleles, respectively. This became 100% if the acceptable measurement errors were applied. The central laboratory correctly reported allele sizes for six standard reference samples, blind to the known result. Our study differs from external quality assessment (EQA) schemes in that these are duplicate results obtained from a large sample of patients across the whole diagnostic range. We strongly recommend that laboratories state an error rate for their measurement on the report, participate in EQA schemes and use reference materials regularly to adjust their own internal standards.

  8. CAG repeat length in androgen receptor gene and male infertility in Egyptian patients.

    Science.gov (United States)

    Mosaad, Y M; Shahin, D; Elkholy, A A-M; Mosbah, A; Badawy, W

    2012-02-01

    The CAG repeat and its association with infertility has been debatable. Therefore, this study was planned to assess the distribution of CAG repeat expansion in Egyptian patients and to investigate its association with male infertility. Forty-five infertile men were eligible for the study in addition to 20 aged-matched fertile males as control. Semen analysis, scrotal sonography, assay of serum testosterone, follicle-stimulating hormone (FSH) and luteinising hormone (LH), and determination of the CAG repeat number within exon 1 of the androgen receptor (AR) gene were carried out. Statistically significant difference was found between infertile and control groups regarding sperm count, sperm motility, serum FSH level and CAG repeats (P CAG repeats (P = 1.0) was found between oligozoospermic and asthenospermic groups; negative correlation was found between CAG repeat length and sperm count, and a positive correlation was found between CAG repeat length and serum FSH (P CAG repeat may be associated with lower AR function with derangement of sperm production, and this may contribute to male infertility in Egyptian men.

  9. Striatal and extrastriatal atrophy in Huntington's disease and its relationship with length of the CAG repeat.

    Science.gov (United States)

    Ruocco, H H; Lopes-Cendes, I; Li, L M; Santos-Silva, M; Cendes, F

    2006-08-01

    Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that affects the striatum most severely. However, except for juvenile forms, relative preservation of the cerebellum has been reported. The objective of the present study was to perform MRI measurements of caudate, putamen, cerebral, and cerebellar volumes and correlate these findings with the length of the CAG repeat and clinical parameters. We evaluated 50 consecutive patients with HD using MRI volumetric measurements and compared them to normal controls. Age at onset of the disease ranged from 4 to 73 years (mean: 43.1 years). The length of the CAG repeat ranged from 40 to 69 (mean: 47.2 CAG). HD patients presented marked atrophy of the caudate and putamen, as well as reduced cerebellar and cerebral volumes. There was a significant correlation between age at onset of HD and length of the CAG repeat, as well as clinical disability and age at onset. The degree of basal ganglia atrophy correlated with the length of the CAG repeat. There was no correlation between cerebellar or cerebral volume and length of the CAG repeat. However, there was a tendency to a positive correlation between duration of disease and cerebellar atrophy. While there was a negative correlation of length of the CAG repeat with age at disease onset and with striatal degeneration, its influence on extrastriatal atrophy, including the cerebellum, was not clear. Extrastriatal atrophy occurs later in HD and may be related to disease duration.

  10. Striatal and extrastriatal atrophy in Huntington's disease and its relationship with length of the CAG repeat

    Directory of Open Access Journals (Sweden)

    H.H. Ruocco

    2006-08-01

    Full Text Available Huntington's disease (HD is an autosomal dominant neurodegenerative disorder that affects the striatum most severely. However, except for juvenile forms, relative preservation of the cerebellum has been reported. The objective of the present study was to perform MRI measurements of caudate, putamen, cerebral, and cerebellar volumes and correlate these findings with the length of the CAG repeat and clinical parameters. We evaluated 50 consecutive patients with HD using MRI volumetric measurements and compared them to normal controls. Age at onset of the disease ranged from 4 to 73 years (mean: 43.1 years. The length of the CAG repeat ranged from 40 to 69 (mean: 47.2 CAG. HD patients presented marked atrophy of the caudate and putamen, as well as reduced cerebellar and cerebral volumes. There was a significant correlation between age at onset of HD and length of the CAG repeat, as well as clinical disability and age at onset. The degree of basal ganglia atrophy correlated with the length of the CAG repeat. There was no correlation between cerebellar or cerebral volume and length of the CAG repeat. However, there was a tendency to a positive correlation between duration of disease and cerebellar atrophy. While there was a negative correlation of length of the CAG repeat with age at disease onset and with striatal degeneration, its influence on extrastriatal atrophy, including the cerebellum, was not clear. Extrastriatal atrophy occurs later in HD and may be related to disease duration.

  11. Reduced CAG repeats length in androgen receptor gene is associated with violent criminal behavior.

    Science.gov (United States)

    Rajender, Singh; Pandu, Guguluth; Sharma, J D; Gandhi, K P C; Singh, Lalji; Thangaraj, Kumarasamy

    2008-09-01

    Androgens mediate their functions through androgen receptors (AR). The two triplet repeats in the AR gene (CAG and GGN) are highly polymorphic among various populations and have been extensively studied in diverse clinical conditions and antisocial personality disorders. Several studies have reported either higher levels of testosterone among rapists or the correlation of shorter CAG repeats with criminal activities. However, to date, no study has analyzed AR gene in rapists worldwide, and no study has been conducted on criminals from Indian subcontinent. Therefore, we have analyzed the AR-CAG repeat length in 645 men, of which 241 were convicted for rape, 107 for murder, 26 for both murder and rape, and 271 were control males. The aim was to explore if there was any correlation between CAG repeat length and criminal behavior. The study revealed significantly shorter CAG repeats in the rapists (mean 18.44 repeats) and murderers (mean 17.59 repeats) compared to the control men (mean 21.19 repeats). The criminals who committed murder after rape had a far shorter mean repeat length (mean 17.31 repeats) in comparison to the controls or those convicted of rape or murder alone. In short, our study suggests that the reduced CAG repeats in the AR gene are associated with criminal behavior. This, along with other studies, would help in understanding the biological factors associated with the antisocial or criminal activities.

  12. HD CAGnome: a search tool for huntingtin CAG repeat length-correlated genes.

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    Ekaterina I Galkina

    Full Text Available BACKGROUND: The length of the huntingtin (HTT CAG repeat is strongly correlated with both age at onset of Huntington's disease (HD symptoms and age at death of HD patients. Dichotomous analysis comparing HD to controls is widely used to study the effects of HTT CAG repeat expansion. However, a potentially more powerful approach is a continuous analysis strategy that takes advantage of all of the different CAG lengths, to capture effects that are expected to be critical to HD pathogenesis. METHODOLOGY/PRINCIPAL FINDINGS: We used continuous and dichotomous approaches to analyze microarray gene expression data from 107 human control and HD lymphoblastoid cell lines. Of all probes found to be significant in a continuous analysis by CAG length, only 21.4% were so identified by a dichotomous comparison of HD versus controls. Moreover, of probes significant by dichotomous analysis, only 33.2% were also significant in the continuous analysis. Simulations revealed that the dichotomous approach would require substantially more than 107 samples to either detect 80% of the CAG-length correlated changes revealed by continuous analysis or to reduce the rate of significant differences that are not CAG length-correlated to 20% (n = 133 or n = 206, respectively. Given the superior power of the continuous approach, we calculated the correlation structure between HTT CAG repeat lengths and gene expression levels and created a freely available searchable website, "HD CAGnome," that allows users to examine continuous relationships between HTT CAG and expression levels of ∼20,000 human genes. CONCLUSIONS/SIGNIFICANCE: Our results reveal limitations of dichotomous approaches compared to the power of continuous analysis to study a disease where human genotype-phenotype relationships strongly support a role for a continuum of CAG length-dependent changes. The compendium of HTT CAG length-gene expression level relationships found at the HD CAGnome now provides

  13. Genetic Association Between Androgen Receptor Gene CAG Repeat Length Polymorphism and Male Infertility: A Meta-Analysis.

    Science.gov (United States)

    Pan, Bihui; Li, Rui; Chen, Yao; Tang, Qiuqin; Wu, Wei; Chen, Liping; Lu, Chuncheng; Pan, Feng; Ding, Hongjuan; Xia, Yankai; Hu, Lingqing; Chen, Daozhen; Sha, Jiahao; Wang, Xinru

    2016-03-01

    The association between polymorphism of androgen receptor gene CAG (AR-CAG) and male infertility in several studies was controversial. Based on studies on association between AR-CAG repeat length and male infertility in recent years, an updated meta-analysis is needed. We aimed to evaluate the association between AR-CAG repeat length and male infertility in advantage of the data in all published reports.We searched for reports published before August 2015 using PubMed, CNKI, VIP, and WanFang. Data on sample size, mean, and standard deviation (SD) of AR-CAG repeat length were extracted independently by 3 investigators.Forty-four reports were selected based on criteria. The overall infertile patients and azoospermic patients were found to have longer AR-CAG repeat length (standard mean difference (SMD) = 0.19, 95% confidence interval (CI): 0.10-0.28, P CAG repeat length was longer in infertile men in Asian, Caucasian, and mixed races (SMD = 0.25, 95% CI: 0.08-0.43, P CAG repeat length was associated with male infertility. The subgroup study on races shows that increased AR-CAG repeat length was associated with male infertility in Asian, Caucasian, and mixed races. Increased AR-CAG repeat length was also associated with azoospermia.This meta-analysis supports that increased androgen receptor CAG length is capable of causing male infertility susceptibility.

  14. Factors influencing the clinical expression of intermediate CAG repeat length mutations of the Huntington's disease gene.

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    Panegyres, Peter K; Shu, Chen-Chun; Chen, Huei-Yang; Paulsen, Jane S

    2015-02-01

    Our aim is to elucidate the clinical variables associated with the development of manifest HD in patients with intermediate CAG repeat lengths. 2,167 participants were seen throughout 44 research sites in the United States, Canada or Australia over a five-year natural history observational study (2006-2011) (Trial # NCT00313495). The Chi-square test and a generalised linear model were used to examine the differences in demographics and cognitive tests among three groups of CAG repeat length. The mixed model was then used to examine the time effect on cognitive assessments by CAG groups. No patient with CAG repeat length 27-35 developed manifest HD, whereas three patients with 36-39 did. Total motor score, maximal chorea score and maximal dystonia score were significantly different at baseline (p CAG 36-39; those with an associated university degree or higher education were less frequently diagnosed as manifest HD (OR 0.10, 95 % CI 0.02-0.54, p = 0.007). Age, smoking and lower education achievement were found to be significantly associated with higher odds of manifest HD in patients with intermediate CAG repeat length mutations.

  15. Polymorphic CAG and GGC repeat lengths in the androgen receptor gene and prostate cancer risk: analysis of a Brazilian population.

    Science.gov (United States)

    Silva Neto, Brasil; Koff, Walter J; Biolchi, Vanderlei; Brenner, Cleber; Biolo, Karlo D; Spritzer, Poli Mara; Brum, Ilma S

    2008-02-01

    Variations in transcriptional activity of the androgen receptor (AR) are related to polymorphic CAG and GGC repeats in exon 1 of the AR gene. We investigated the association between CAG and GGC repeat length and the risk of prostate cancer in a case-control study from a Brazilian population. We evaluated 49 patients and 51 healthy controls. DNA was extracted from peripheral leukocytes and the AR gene was analyzed by fragment analysis (GeneMapper software, Applied Biosystems, Foster City, California, USA). CAG and GGC mean lengths were not different between cases and controls. The risk for prostate cancer was higher for CAG repeats repeat lengths (CAG + GGC) repeats ( 17) were not associated with risk for prostate cancer (OR = 1.13 [95% CI 0.47-2.75]). In conclusion, fewer number of CAG repeats and total repeats (CAG + GGC) in the AR gene may be associated with increased risk for prostate cancer.

  16. Relationship between CAG repeat length and brain volume in premanifest and early Huntington's disease.

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    Henley, Susie M D; Wild, Edward J; Hobbs, Nicola Z; Scahill, Rachael I; Ridgway, Gerard R; Macmanus, David G; Barker, Roger A; Fox, Nick C; Tabrizi, Sarah J

    2009-02-01

    Huntington's disease (HD) is caused by an expanded CAG repeat on the gene encoding for the protein huntingtin. There are conflicting findings about the extent to which repeat length predicts signs of the disease or severity of disease progression in adults. This study examined the relationship between CAG repeat length and brain volume in a large cohort of pre- and post-motor onset HD gene carriers, using voxel-based morphometry (VBM), an approach which allowed us to investigate the whole brain without defining a priori regions of interest. We also used VBM to examine group differences between 20 controls, 21 premanifest, and 40 early HD subjects. In the 61 mutation-positive subjects higher CAG repeat length was significantly associated with reduced volume of the body of the caudate nucleus bilaterally, left putamen, right insula, right parahippocampal gyrus, right anterior cingulate, and right occipital lobe, after correcting for age. The group contrasts showed significant reduction in grey matter volume in the early HD group relative to controls in widespread cortical as well as subcortical areas but there was no evidence of difference between controls and premanifest subjects. Overall we have demonstrated that increased CAG repeat length is associated with atrophy in extra-striatal as well as striatal regions, which has implications for the monitoring of disease-modifying therapies in the condition.

  17. Correlation of CAG repeat length between the maternal and paternal allele of the Huntingtin gene: evidence for assortative mating

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    Wassink Tom

    2011-10-01

    Full Text Available Abstract Triplet repeats contribute to normal variation in behavioral traits and when expanded, cause brain disorders. While Huntington's Disease is known to be caused by a CAG triplet repeat in the gene Huntingtin, the effect of CAG repeats on brain function below disease threshold has not been studied. The current study shows a significant correlation between the CAG repeat length of the maternal and paternal allele in the Huntingtin gene among healthy subjects, suggesting assortative mating.

  18. Variation in CAG and GGN repeat lengths and CAG/GGN haplotype in androgen receptor gene polymorphism and prostate carcinoma in Nigerians.

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    Akinloye, O; Gromoll, J; Simoni, M

    2011-01-01

    Prostate cancer has become the most common cancer in Nigerian men. The growth of the prostate gland depends on circulating androgens and intracellular steroid signalling pathways. The effects of androgens are mediated through the androgen receptor (AR), a nuclear transcription factor encoded by the AR gene. The common polymorphisms, CAG and GGN repeats, in exon 1 of this gene have been implicated as possible risk factors. Thus far, existing supporting data are scanty and none are from sub-Saharan African populations. Therefore, this study investigates the possible association between AR polymorphism repeat length (CAG and GGN) and prostate cancer in Nigerians. A total of 261 subjects (70 with prostate cancer, 68 with benign prostate hyperplasia [BPH], 123 age-matched apparently normal subjects as controls) were studied. CAG and GGN repeats length were determined by fragment length analysis using GeneScan. The CAG repeat length in prostate cancer and in BPH compared to the controls was significantly different (P CAG repeats showing a significant odds ratio (OR) in both cases. However, this was not observed in GGN repeat length, which showed no significant difference between cases and controls (P > 0.05). CAG and GGN haplotype variation showed no significant difference between cases and controls (P > 0.05), except that the haplotypes CAG > or =21 and GGN CAG repeat length is a risk factor for prostate cancer, and also suggests an association with BPH.

  19. A Familial Factor Independent of CAG Repeat Length Influences Age at Onset of Machado-Joseph Disease

    OpenAIRE

    DeStefano, Anita L.; Cupples, L. Adrienne; Maciel, Patricia; Gaspar, Claudia; Radvany, Joao; Dawson, David M.; Sudarsky, Lewis; Corwin, Lee; Coutinho, Paula; MacLeod, Patrick; Sequeiros, Jorge; Rouleau, Guy A.; Farrer, Lindsay A.

    1996-01-01

    Machado-Joseph disease (MJD) is a late-onset, progressive, neurodegenerative disorder caused by the expansion of an unstable trinucleotide (CAG) repeat sequence in a novel gene (MJD1) on chromosome 14. Previous studies showed that age at onset is negatively correlated with the number of CAG repeat units, but only part of the variation in onset age is explained by CAG repeat length. Ages at onset and CAG repeat lengths of 136 MJD patients from 23 kindreds of Portuguese descent were analyzed, t...

  20. Long-term disability and prognosis in dentatorubral-pallidoluysian atrophy: a correlation with CAG repeat length.

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    Hasegawa, Arika; Ikeuchi, Takeshi; Koike, Ryoko; Matsubara, Nae; Tsuchiya, Miyuki; Nozaki, Hiroaki; Homma, Atsushi; Idezuka, Jiro; Nishizawa, Masatoyo; Onodera, Osamu

    2010-08-15

    Dentatorubral-pallidoluysian atrophy (DRPLA) is a rare autosomal dominant neurodegenerative disorder caused by CAG repeat expansion. Previous studies demonstrated that the onset of DRPLA is closely associated with CAG repeat length. However, the natural history of DRPLA has not yet been evaluated. We here retrospectively investigated the factors that determine the disease milestones and prognosis in 183 Japanese patients genetically diagnosed with DRPLA. We determined the age at onset, age at which each of the subsequent clinical manifestations appeared, age at becoming wheelchair-bound, and age at death. Kaplan-Meier analysis revealed that the patients with CAG repeats larger than the median length of 65 repeats developed each of the clinical features of DRPLA at a younger age than those with repeats. The patients became wheelchair-bound at a median age of 33 years (n = 61; range, 3-77 years) and died at a median age of 49 years (n = 23; range, 18-80 years). The ages at becoming wheelchair-bound and at death strongly correlated with the expanded CAG repeat length. Moreover, the patients with >or=65 CAG repeats showed a more severe long-term disability and a poorer prognosis. In contrast, the rate of progression after the onset did not correlate with CAG repeat length. The CAG repeat length may have a considerable effect on not only the disease onset but also the disease milestones and prognosis in DRPLA patients. These effects of CAG repeat length may be relevant in designing future clinical therapeutic trials.

  1. CAG repeat length does not associate with the rate of cerebellar degeneration in spinocerebellar ataxia type 3

    OpenAIRE

    Huang, Shang-Ran; Wu, Yu-Te; Jao, Chii-Wen; Soong, Bing-wen; Lirng, Jiing-Feng; Wu, Hsiu-Mei; Wang, Po-Shan

    2016-01-01

    This cross-sectional study investigated the correlation between the CAG repeat length and the degeneration of cerebellum in spinocerebellar ataxia type 3 (SCA3) patients based on neuroimaging approaches. Forty SCA3 patients were recruited and classified into two subgroups according to their CAG repeat lengths (≥ 74 and

  2. Androgen receptor CAG repeats length polymorphism and the risk of polycystic ovarian syndrome (PCOS.

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    Singh Rajender

    Full Text Available OBJECTIVE: Polycystic ovarian syndrome (PCOS refers to an inheritable androgen excess disorder characterized by multiple small follicles located at the ovarian periphery. Hyperandrogenism in PCOS, and inverse correlation between androgen receptor (AR CAG numbers and AR function, led us to hypothesize that CAG length variations may affect PCOS risk. METHODS: CAG repeat region of 169 patients recruited following strictly defined Rotterdam (2003 inclusion criteria and that of 175 ethnically similar control samples, were analyzed. We also conducted a meta-analysis on the data taken from published studies, to generate a pooled estimate on 2194 cases and 2242 controls. RESULTS: CAG bi-allelic mean length was between 8.5 and 24.5 (mean = 17.43, SD = 2.43 repeats in the controls and between 11 and 24 (mean = 17.39, SD = 2.29 repeats in the cases, without any significant difference between the two groups. Further, comparison of bi-allelic mean and its frequency distribution in three categories (short, moderate and long alleles did not show any significant difference between controls and various case subgroups. Frequency distribution of bi-allelic mean in two categories (extreme and moderate alleles showed over-representation of extreme sized alleles in the cases with marginally significant value (50.3% vs. 61.5%, χ(2 = 4.41; P = 0.036, which turned insignificant upon applying Bonferroni correction for multiple comparisons. X-chromosome inactivation analysis showed no significant difference in the inactivation pattern of CAG alleles or in the comparison of weighed bi-allelic mean between cases and controls. Meta-analysis also showed no significant correlation between CAG length and PCOS risk, except a minor over-representation of short CAG alleles in the cases. CONCLUSION: CAG bi-allelic mean length did not differ between controls and cases/case sub-groups nor did the allele distribution. Over-representation of short

  3. Genetic Association Between Androgen Receptor Gene CAG Repeat Length Polymorphism and Male Infertility: A Meta-Analysis

    OpenAIRE

    Pan, Bihui; Li, Rui; CHEN, YAO; Tang, Qiuqin; Wu, Wei; Chen, Liping; Lu, Chuncheng; Pan, Feng; Hongjuan DING; Xia,Yankai; Hu, Lingqing; Chen, Daozhen; Sha, Jiahao; Wang, Xinru

    2016-01-01

    Abstract The association between polymorphism of androgen receptor gene CAG (AR-CAG) and male infertility in several studies was controversial. Based on studies on association between AR-CAG repeat length and male infertility in recent years, an updated meta-analysis is needed. We aimed to evaluate the association between AR-CAG repeat length and male infertility in advantage of the data in all published reports. We searched for reports published before August 2015 using PubMed, CNKI, VIP, an...

  4. Impact of CAG repeat length in the androgen receptor gene on male infertility - a meta-analysis.

    Science.gov (United States)

    Xiao, Feifan; Lan, Aihua; Lin, Zhidi; Song, Jianfei; Zhang, Yuening; Li, Jiatong; Gu, Kailong; Lv, Baihao; Zhao, Dong; Zeng, Siping; Zhang, Ruoheng; Zhao, Wei; Pan, Zhengyan; Deng, Xiaozhen; Yang, Xiaoli

    2016-07-01

    CAG repeats are polymorphic nucleotide repeats present in the androgen receptor gene. Many studies have estimated the association between CAG repeat length and male infertility, but the conclusions are controversial. Previous meta-analyses have come to different conclusions; however, new studies have been published. An updated meta-analysis was conducted. PubMed, CBM, CNKI and Web of Science databases were systematically searched for studies published from 1 January 2000 to 1 October 2015. Case-control studies on the association between CAG repeat length and male infertility using appropriate methodology were included. Forty studies were selected, including 3858 cases and 3161 controls. Results showed statistically significantly longer CAG repeat length among cases compared with controls (SMD = 0.14; 95% CI, 0.02-0.26). Shorter repeat length was associated with a lower risk of male infertility compared with a longer repeat length in the overall analysis (OR = 0.79, 95% CI: 0.66-0.95). Moreover, CAG repeat length was associated with male infertility in Caucasian populations, but not Asian or Egyptian populations. Subgroup analysis revealed no significant difference in German populations, but CAG repeat length was associated with male infertility in China and the USA. There were no significant differences between cases and controls in azoospermia and severe oligozoospermia.

  5. DRPLA transgenic mouse substrains carrying single copy of full-length mutant human DRPLA gene with variable sizes of expanded CAG repeats exhibit CAG repeat length- and age-dependent changes in behavioral abnormalities and gene expression profiles.

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    Suzuki, Kazushi; Zhou, Jiayi; Sato, Toshiya; Takao, Keizo; Miyagawa, Tsuyoshi; Oyake, Mutsuo; Yamada, Mitunori; Takahashi, Hitoshi; Takahashi, Yuji; Goto, Jun; Tsuji, Shoji

    2012-05-01

    Dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant progressive neurodegenerative disorder with intellectual deterioration and various motor deficits including ataxia, choreoathetosis, and myoclonus, caused by an abnormal expansion of CAG repeats in the DRPLA gene. Longer expanded CAG repeats contribute to an earlier age of onset, faster progression, and more severe neurological symptoms in DRPLA patients. In this study, we have established DRPLA transgenic mouse lines (sublines) harboring a single copy of the full-length mutant human DRPLA gene carrying various lengths of expanded CAG repeats (Q76, Q96, Q113, and Q129), which have clearly shown motor deficits and memory disturbance whose severity increases with the length of expanded CAG repeats and age, and successfully replicated the CAG repeat length- and age-dependent features of DRPLA patients. Neuronal intranuclear accumulation of the mutant DRPLA protein has been suggested to cause transcriptional dysregulation, leading to alteration in gene expression and neuronal dysfunction. In this study, we have conducted a comprehensive analysis of gene expression profiles in the cerebrum and cerebellum of transgenic mouse lines at 4, 8, and 12 weeks using multiple microarray platforms, and demonstrated that both the number and expression levels of the altered genes are highly dependent on CAG repeat length and age in both brain regions. Specific groups of genes and their function categories were identified by further agglomerative cluster analysis and gene functional annotation analysis. Calcium signaling and neuropeptide signaling, among others, were implicated in the pathophysiology of DRPLA. Our study provides unprecedented CAG-repeat-length-dependent mouse models of DRPLA, which are highly valuable not only for elucidating the CAG-repeat-length-dependent pathophysiology of DRPLA but also for developing therapeutic strategies for DRPLA.

  6. Analysis of the androgen receptor CAG repeats length in Iranian patients with idiopathic non-obstructive azoospermia

    Directory of Open Access Journals (Sweden)

    Sohreh Zare-Karizi

    2016-03-01

    Conclusion: Although our results indicate a significant negative correlation between the length of CAG repeat and male infertility, however, other genetic modifiers may be required in order to cause male infertility.

  7. Relationships among androgen receptor CAG repeat polymorphism, sex hormones and penile length in Han adult men from China: a cross-sectional study

    OpenAIRE

    Yan-Min Ma; Kai-Jie Wu; Liang Ning; Jin Zeng; Bo Kou; Hong-Jun Xie; Zhen-Kun Ma; Xin-Yang Wang; Yong-Guang Gong; Da-Lin He

    2014-01-01

    This study aimed to investigate the correlations among androgen receptor (AR) CAG repeat polymorphism, sex hormones and penile length in healthy Chinese young adult men. Two hundred and fifty-three healthy men (aged 22.8 ± 3.1 years) were enrolled. The individuals were grouped as CAG short (CAG S ) if they harbored repeat length of ≤20 or as CAG long (CAG L ) if their CAG repeat length was >20. Body height/weight, penile length and other parameters were examined and recorded by the specified ...

  8. CAG repeat length does not associate with the rate of cerebellar degeneration in spinocerebellar ataxia type 3

    Directory of Open Access Journals (Sweden)

    Shang-Ran Huang

    2017-01-01

    Full Text Available This cross-sectional study investigated the correlation between the CAG repeat length and the degeneration of cerebellum in spinocerebellar ataxia type 3 (SCA3 patients based on neuroimaging approaches. Forty SCA3 patients were recruited and classified into two subgroups according to their CAG repeat lengths (≥74 and <74. We measured each patient's Scale for the Assessment and Rating of Ataxia (SARA score, N-acetylaspartate (NAA/creatine (Cr ratios based on magnetic resonance spectroscopy (MRS, and 3-dimensional fractal dimension (3D-FD values derived from magnetic resonance imaging (MRI results. Furthermore, the 3D-FD values were used to construct structural covariance networks based on graph theoretical analysis. The results revealed that SCA3 patients with a longer CAG repeat length demonstrated earlier disease onset. However, the CAG repeat length did not significantly correlate with their SARA scores, cerebellar NAA/Cr ratios or cerebellar 3D-FD values. Network dissociation between cerebellar regions and parietal-occipital regions was found in SCA3 patients with CAG ≥ 74, but not in those with CAG < 74. In conclusion, the CAG repeat length is uncorrelated with the change of SARA score, cerebellar function and cerebellar structure in SCA3. Nevertheless, a longer CAG repeat length may indicate early structural covariance network dissociation.

  9. Shorter CAG repeat length in the AR gene is associated with poor outcome in head and neck cancer

    DEFF Research Database (Denmark)

    Rosa, Fabíola Encinas; dos Santos, Rodrigo Mattos; Poli-Frederico, Regina Célia

    2007-01-01

    of the AR [CAG](n) repeat length. Sixty-nine individuals without cancer were used as a control group for both procedures. The Log-rank test was used to compare overall survival and disease-free survival curves. The Cox proportional hazards regression models were performed to determine the [CAG](n) repeats...... as an independent prognostic factor. RESULTS: Patients with alleles survival (P=0.0325) and with recurrence or metastasis (RR 2.52, CI 95%). In the female group, the allele 2 (longer allele) showed a significant lower mean of [CAG](n) repeat when...... compared to the control group. Microsatellite instability was detected in nine cases in both procedures. In six out of these nine cases, we observed a reduction of the AR [CAG](n) repeat length. LOH was detected in one out of 17 women informative for oral cancer in both procedures. CONCLUSION...

  10. Effect of CAG repeat length on psychiatric disorders in Huntington's disease.

    Science.gov (United States)

    Vassos, Evangelos; Panas, Marios; Kladi, Athina; Vassilopoulos, Dimitrios

    2008-06-01

    There is strong evidence that the length of CAG repeats, in patients with Huntington's disease (HD), govern the age of onset and the rate of clinical progression of neurological symptoms. However, psychiatric manifestations of the disease have not been examined as comprehensively. Seventy two Greek patients with Huntington's disease had DNA testing and were clinically assessed by means of a semi-structured interview (SCID) and four self-rated questionnaires. Genotype-phenotype correlations were examined. The CAG repeat length had a significant negative association with the age of onset of psychiatric disorders, the total level of functioning and the MMSE. However, the probability of developing a psychiatric disorder and the severity of psychiatric symptoms were not determined by the trinucleotide expansion, after controlling for the duration of illness, sex, and age of the subjects. The factors that determine the development of psychiatric symptoms in HD patients seem not to be limited to a dose related toxicity of the expanded Huntington. It is hypothesized that alternative genetic or environmental factors underlie the pathogenesis of the psychiatric phenotype.

  11. Relationships among androgen receptor CAG repeat polymorphism, sex hormones and penile length in Han adult men from China: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Yan-Min Ma

    2014-06-01

    Full Text Available This study aimed to investigate the correlations among androgen receptor (AR CAG repeat polymorphism, sex hormones and penile length in healthy Chinese young adult men. Two hundred and fifty-three healthy men (aged 22.8 ± 3.1 years were enrolled. The individuals were grouped as CAG short (CAG S if they harbored repeat length of ≤20 or as CAG long (CAG L if their CAG repeat length was >20. Body height/weight, penile length and other parameters were examined and recorded by the specified physicians; CAG repeat polymorphism was determined by the polymerase chain reaction (PCR method; and the serum levels of the sex hormones were detected by radioimmunoassay. Student's t-test or linear regression analysis was used to assess the associations among AR CAG repeat polymorphism, sex hormones and penile length. This investigation showed that the serum total testosterone (T level was positively associated with the AR CAG repeat length (P = 0.01; whereas, no significant correlation of T or AR CAG repeat polymorphism with the penile length was found (P = 0.593. Interestingly, an inverse association was observed between serum prolactin (PRL levels and penile length by linear regression analyses (β= −0.024, P = 0.039, 95% confidence interval (CI: −0.047, 0. Collectively, this study provides the first evidence that serum PRL, but not T or AR CAG repeat polymorphism, is correlated with penile length in the Han adult population from northwestern China.

  12. Relationships among androgen receptor CAG repeat polymorphism, sex hormones and penile length in Han adult men from China: a cross-sectional study.

    Science.gov (United States)

    Ma, Yan-Min; Wu, Kai-Jie; Ning, Liang; Zeng, Jin; Kou, Bo; Xie, Hong-Jun; Ma, Zhen-Kun; Wang, Xin-Yang; Gong, Yong-Guang; He, Da-Lin

    2014-01-01

    This study aimed to investigate the correlations among androgen receptor (AR) CAG repeat polymorphism, sex hormones and penile length in healthy Chinese young adult men. Two hundred and fifty-three healthy men (aged 22.8 ± 3.1 years) were enrolled. The individuals were grouped as CAG short (CAG S ) if they harbored repeat length of ≤ 20 or as CAG long (CAG L ) if their CAG repeat length was >20. Body height/weight, penile length and other parameters were examined and recorded by the specified physicians; CAG repeat polymorphism was determined by the polymerase chain reaction (PCR) method; and the serum levels of the sex hormones were detected by radioimmunoassay. Student's t-test or linear regression analysis was used to assess the associations among AR CAG repeat polymorphism, sex hormones and penile length. This investigation showed that the serum total testosterone (T) level was positively associated with the AR CAG repeat length (P = 0.01); whereas, no significant correlation of T or AR CAG repeat polymorphism with the penile length was found (P = 0.593). Interestingly, an inverse association was observed between serum prolactin (PRL) levels and penile length by linear regression analyses (β= -0.024, P = 0.039, 95% confidence interval (CI): -0.047, 0). Collectively, this study provides the first evidence that serum PRL, but not T or AR CAG repeat polymorphism, is correlated with penile length in the Han adult population from northwestern China.

  13. The relationship between CAG repeat length and clinical progression in Huntington's disease.

    Science.gov (United States)

    Ravina, Bernard; Romer, Megan; Constantinescu, Radu; Biglan, Kevin; Brocht, Alicia; Kieburtz, Karl; Shoulson, Ira; McDermott, Michael P

    2008-07-15

    The objective of this study was to examine the relationship between CAG repeat length (CAGn) and clinical progression in patients with Huntington's disease (HD). There are conflicting reports about the relationship between CAGn and clinical progression of HD. We conducted an analysis of data from the Coenzyme Q10 and Remacemide Evaluation in Huntington's Disease (CARE-HD) clinical trial. We modeled progression over 30 months on the Unified Huntington's Disease Rating Scale (UHDRS) and supplemental neuropsychological and behavioral tests using multiple linear regression. Mean subject age was 47.9 +/- 10.5 years and mean CAGn was 45.0 +/- 4.1. Multiple linear regression revealed statistically significant associations between CAGn and worsening on several motor, cognitive, and functional outcomes, but not behavioral outcomes. Many effects were clinically important; 10 additional CAG repeats were associated with an 81% increase in progression on the Independence Scale. These associations were not observed in the absence of age adjustment. Age at the time of assessment confounds the association between CAGn and progression. Adjusting for age shows that longer CAGn is associated with greater clinical progression of HD. This finding may account for the variable results from previous studies examining CAGn and progression. Adjusting for CAGn may be important for clinical trials.

  14. Non-linear association between androgen receptor CAG repeat length and risk of male subfertility--a meta-analysis.

    Science.gov (United States)

    Nenonen, H A; Giwercman, A; Hallengren, E; Giwercman, Y L

    2011-08-01

    The CAG repeat in the androgen receptor (AR) has been widely studied in association with male infertility, but the results are conflicting. In a recent meta-analysis, infertile men had repeat longer CAG stretch than fertile men when analysed in a linear regression model assuming that AR function diminishes with increasing CAG length. However, in vitro, a non-linear activity pattern was recently demonstrated so that ARs containing short and long stretches, respectively, displayed lower activity than the AR of median length. These results prompted us to explore the possible association between CAG number and male infertility risk in a stratified manner on the basis of data from the mentioned meta-analysis and subjects from our clinical unit. The study population included 3915 men, 1831 fertile and 2084 infertile. Data were divided into three categories: CAGCAG 22-23 (reference) and CAG>23 and analysed in a binary logistic regression model. Men with CAGCAG>23 had 20% increased odds ratio of infertility compared with carriers of the median lengths [for CAGCAG>23: p=0.02, 95% CI: 1.03-1.44]. These results show that an alternative model to a linear one for the genotype-phenotype association in relation to AR CAG repeats is likely, as lengths close to the median confine lowest risk of infertility.

  15. Relationships among androgen receptor CAG repeat polymorphism, sex hormones and penile length in Han adult men from China:a cross-sectional study

    Institute of Scientific and Technical Information of China (English)

    YanMin Ma; DaLin He; KaiJie Wu; Liang Ning; Jin Zeng; Bo Kou; HongJun Xie; ZhenKun Ma; XinYang Wang; YongGuang Gong

    2014-01-01

    This study aimed to investigate the correlations among androgen receptor (AR) CAG repeat polymorphism, sex hormones and penile length in healthy Chinese young adult men. Two hundred and iffty-three healthy men (aged 22.8 ± 3.1 years) were enrolled. The individuals were grouped as CAG short (CAGS) if they harbored repeat length of≤20 or as CAG long (CAGL) if their CAG repeat length was>20. Body height/weight, penile length and other parameters were examined and recorded by the speciifed physicians;CAG repeat polymorphism was determined by the polymerase chain reaction (PCR) method;and the serum levels of the sex hormones were detected by radioimmunoassay. Student’s t-test or linear regression analysis was used to assess the associations among AR CAG repeat polymorphism, sex hormones and penile length. This investigation showed that the serum total testosterone (T) level was positively associated with the AR CAG repeat length (P= 0.01); whereas, no signiifcant correlation of T or AR CAG repeat polymorphism with the penile length was found (P= 0.593). Interestingly, an inverse association was observed between serum prolactin (PRL) levels and penile length by linear regression analyses (b=-0.024, P= 0.039, 95%conifdence interval (CI):-0.047, 0). Collectively, this study provides the ifrst evidence that serum PRL, but not T or AR CAG repeat polymorphism, is correlated with penile length in the Han adult population from northwestern China.

  16. Androgen receptor gene CAG repeat length as modifier of the association between Persistent Organohalogen Pollutant exposure markers and semen characteristics

    DEFF Research Database (Denmark)

    Giwercman, Aleksander; Rylander, Lars; Rignell-Hydbom, Anna;

    2007-01-01

    OBJECTIVES: Exposure to persistent organohalogen pollutants was suggested to impair male reproductive function. A gene-environment interaction has been proposed. No genes modifying the effect of persistent organohalogen pollutants on reproductive organs have yet been identified. We aimed...... and morphology) and DNA fragmentation index (DFI) were determined. CAG and GGN repeat lengths were determined by direct sequencing of leukocyte DNA. RESULTS: A statistically significant interaction was found between the CB-153 group and CAG repeat category in relation to sperm concentration and total sperm count...

  17. A critical window of CAG repeat-length correlates with phenotype severity in the R6/2 mouse model of Huntington's disease.

    Science.gov (United States)

    Cummings, Damian M; Alaghband, Yasaman; Hickey, Miriam A; Joshi, Prasad R; Hong, S Candice; Zhu, Chunni; Ando, Timothy K; André, Véronique M; Cepeda, Carlos; Watson, Joseph B; Levine, Michael S

    2012-01-01

    The R6/2 mouse is the most frequently used model for experimental and preclinical drug trials in Huntington's disease (HD). When the R6/2 mouse was first developed, it carried exon 1 of the huntingtin gene with ~150 cytosine-adenine-guanine (CAG) repeats. The model presented with a rapid and aggressive phenotype that shared many features with the human condition and was particularly similar to juvenile HD. However, instability in the CAG repeat length due to different breeding practices has led to both decreases and increases in average CAG repeat lengths among colonies. Given the inverse relationship in human HD between CAG repeat length and age at onset and to a degree, the direct relationship with severity of disease, we have investigated the effect of altered CAG repeat length. Four lines, carrying ~110, ~160, ~210, and ~310 CAG repeats, were examined using a battery of tests designed to assess the basic R6/2 phenotype. These included electrophysiological properties of striatal medium-sized spiny neurons, motor activity, inclusion formation, and protein expression. The results showed an unpredicted, inverted "U-shaped" relationship between CAG repeat length and phenotype; increasing the CAG repeat length from 110 to 160 exacerbated the R6/2 phenotype, whereas further increases to 210 and 310 CAG repeats greatly ameliorated the phenotype. These findings demonstrate that the expected relationship between CAG repeat length and disease severity observed in humans is lost in the R6/2 mouse model and highlight the importance of CAG repeat-length determination in preclinical drug trials that use this model.

  18. CAG repeat lengths > or =335 attenuate the phenotype in the R6/2 Huntington's disease transgenic mouse.

    Science.gov (United States)

    Dragatsis, I; Goldowitz, D; Del Mar, N; Deng, Y P; Meade, C A; Liu, Li; Sun, Z; Dietrich, P; Yue, J; Reiner, A

    2009-03-01

    With spontaneous elongation of the CAG repeat in the R6/2 transgene to > or =335, resulting in a transgene protein too large for passive entry into nuclei via the nuclear pore, we observed an abrupt increase in lifespan to >20 weeks, compared to the 12 weeks common in R6/2 mice with 150 repeats. In the > or =335 CAG mice, large ubiquitinated aggregates of mutant protein were common in neuronal dendrites and perikaryal cytoplasm, but intranuclear aggregates were small and infrequent. Message and protein for the > or =335 CAG transgene were reduced to one-third that in 150 CAG R6/2 mice. Neurological and neurochemical abnormalities were delayed in onset and less severe than in 150 CAG R6/2 mice. These findings suggest that polyQ length and pathogenicity in Huntington's disease may not be linearly related, and pathogenicity may be less severe with extreme repeats. Both diminished mutant protein and reduced nuclear entry may contribute to phenotype attenuation.

  19. Effects of CAG repeat length, HTT protein length and protein context on cerebral metabolism measured using magnetic resonance spectroscopy in transgenic mouse models of Huntington's disease.

    Science.gov (United States)

    Jenkins, Bruce G; Andreassen, Ole A; Dedeoglu, Alpaslan; Leavitt, Blair; Hayden, Michael; Borchelt, David; Ross, Christopher A; Ferrante, Robert J; Beal, M Flint

    2005-10-01

    Huntington's disease is a neurodegenerative illness caused by expansion of CAG repeats at the N-terminal end of the protein huntingtin. We examined longitudinal changes in brain metabolite levels using in vivo magnetic resonance spectroscopy in five different mouse models. There was a large (>50%) exponential decrease in N-acetyl aspartate (NAA) with time in both striatum and cortex in mice with 150 CAG repeats (R6/2 strain). There was a linear decrease restricted to striatum in N171-82Q mice with 82 CAG repeats. Both the exponential and linear decreases of NAA were paralleled in time by decreases in neuronal area measured histologically. Yeast artificial chromosome transgenic mice with 72 CAG repeats, but low expression levels, had less striatal NAA loss than the N171-82Q mice (15% vs. 43%). We evaluated the effect of gene context in mice with an approximate 146 CAG repeat on the hypoxanthine phosphoribosyltransferase gene (HPRT). HPRT mice developed an obese phenotype in contrast to weight loss in the R6/2 and N171-82Q mice. These mice showed a small striatal NAA loss (21%), and a possible increase in brain lipids detectable by magnetic resonance (MR) spectroscopy and decreased brain water T1. Our results indicate profound metabolic defects that are strongly affected by CAG repeat length, as well as gene expression levels and protein context.

  20. Non-linear association between androgen receptor CAG and GGN repeat lengths and reproductive parameters in fertile European and Inuit men

    DEFF Research Database (Denmark)

    Brokken, L J S; Rylander, L; Jönsson, B A

    2013-01-01

    -positive germ cells. Subjects with either short or long CAG had increased seminal levels of prostate-specific antigen and neutral α-glucosidase activity. Compared to men with the median GGN length of 23, those with shorter GGN repeats had higher levels of inhibin B, higher proportions of normal and progressive......Recently the dogma that there is an inverse linear association between androgen receptor (AR) CAG and GGN polymorphisms and receptor activity has been challenged. We analysed the pattern of association between 21 male reproductive phenotypes and AR CAG/GGN repeat lengths in 557 proven-fertile men....... A linear association was only found between sperm DNA fragmentation index (DFI) and CAG length, and between inhibin B and GGN length. Men with longer CAG then the reference (22-24), had higher oestradiol levels, whereas men with shorter CAG stretches had a higher DFI and a higher proportion of Fas...

  1. Heterogenous effect of androgen receptor CAG tract length on testicular germ cell tumor risk: shorter repeats associated with seminoma but not other histologic types.

    Science.gov (United States)

    Davis-Dao, Carol A; Siegmund, Kimberly D; Vandenberg, David J; Skinner, Eila C; Coetzee, Gerhard A; Thomas, Duncan C; Pike, Malcolm C; Cortessis, Victoria K

    2011-08-01

    Increasing rates of testicular germ cells tumors (TGCTs) overtime suggest that environmental factors are involved in disease etiology, but familial risk and genome-wide association studies implicate genetic factors as well. We investigated whether variation in the functional CAG(n) polymorphism in the androgen receptor (AR) gene is associated with TGCT risk, using data from a population-based family study. We estimated odds ratios (OR) and 95% confidence intervals (CI) for the association of CAG repeat length and TGCT risk using matched pairs logistic regression. Analyses of 273 TGCT case-mother pairs revealed no association between AR CAG repeat length and overall TGCT risk. However, risk of seminoma was significantly associated with shorter CAG repeat length [CAG 20-21 versus CAG ≤ 19: OR = 0.82 (95% CI: 0.43-1.58), CAG 22-23 versus CAG ≤ 19: OR = 0.39 (95% CI: 0.19-0.83) and CAG ≥ 24 versus CAG ≤ 19: OR = 0.42 (95% CI: 0.20-0.86)], with a highly significant trend over these four categories of decreasing CAG repeat length (P(trend) = 0.0030). This is the first report of a statistically significant association between AR CAG repeat length and seminoma risk, suggesting that increased AR transactivation may be involved in development of seminoma and/or progression of carcinoma in situ/intratubular germ cell neoplasia unclassified to seminoma. This result provides a rationale whereby androgenic environmental compounds could contribute to increases in TGCT incidence, and identifies for the first time a potential biological pathway influencing whether TGCTs achieve seminomatous versus nonseminomatous histology, a clinically and biologically important distinction.

  2. Assessment of Correlation between Androgen Receptor CAG Repeat Length and Infertility in Infertile Men Living in Khuzestan, Iran

    Directory of Open Access Journals (Sweden)

    Saeid Reza Khatami

    2015-02-01

    Full Text Available Background: The androgen receptor (AR gene contains a polymorphic trinucleotide repeat that encodes a polyglutamine tract in its N-terminal transactivation domain (NTAD. We aimed to find a correlation between the length of this polymorphic tract and azoospermia or oligozoospermia in infertile men living in Khuzestan, Iran. Materials and Methods: In this case-control study during two years till 2010, we searched for microdeletions in the Y chromosome in 84 infertile male patients with normal karyotype who lived in Khuzestan Province, Southwest of Iran. All cases (n=12 of azoospermia or oligozoospermia resulting from Y chromosome microdeletions were excluded from our study. The number of CAG repeats in exon 1 of the AR gene was determined in 72 patients with azoospermia or oligozoospermia and in 72 fertile controls, using the polymerase chain reaction (PCR and polyacrylamide gel electrophoresis. Results: Microdeletions were detected in 14.3% (n=12 patients suffering severe oligozoospermia. The mean CAG repeat length was 18.99 ± 0.35 (range, 11-26 and 19.96 ± 0.54 (range, 12-25 in infertile males and controls, respectively. Also in the infertile group, the most common allele was 19 (26.38%, while in controls, it was 25 (22.22%. Conclusion: Y chromosome microdeletions could be one of the main reasons of male infertility living in Khuzestan Province, while there was no correlation between CAG length in AR gene with azoospermia or oligozoospermia in infertile men living in Khuzestan, Iran.

  3. Direct and accurate measurement of CAG repeat configuration in the ataxin-1 (ATXN-1) gene by "dual-fluorescence labeled PCR-restriction fragment length analysis".

    Science.gov (United States)

    Lin, Jiang X; Ishikawa, Kinya; Sakamoto, Masaki; Tsunemi, Taiji; Ishiguro, Taro; Amino, Takeshi; Toru, Shuta; Kondo, Ikuko; Mizusawa, Hidehiro

    2008-01-01

    Spinocerebellar ataxia type 1 (SCA1; OMIM: #164400) is an autosomal dominant cerebellar ataxia caused by an expansion of CAG repeat, which encodes polyglutamine, in the ataxin-1 (ATXN1) gene. Length of polyglutamine in the ATXN1 protein is the critical determinant of pathogenesis of this disease. Molecular diagnosis of SCA1 is usually undertaken by assessing the length of CAG repeat configuration using primers spanning this configuration. However, this conventional method may potentially lead to misdiagnosis in assessing polyglutamine-encoding CAG repeat length, since CAT interruptions may be present within the CAG repeat configuration, not only in normal controls but also in neurologically symptomatic subjects. We developed a new method for assessing actual CAG repeat numbers not interrupted by CAT sequences. Polymerase chain reaction using a primer pair labeled with two different fluorescences followed by restriction enzyme digestion with SfaNI which recognizes the sequence "GCATC(N)(5)", lengths of actual CAG repeats that encode polyglutamine were directly detected. We named this method "dual fluorescence labeled PCR-restriction fragment length analysis". We found that numbers of actual CAG repeat encoding polyglutamine do not overlap between our cohorts of normal chromosomes (n=385) and SCA1 chromosomes (n=5). We conclude that the present method is a useful way for molecular diagnosis of SCA1.

  4. Non-linear association between androgen receptor CAG and GGN repeat lengths and reproductive parameters in fertile European and Inuit men.

    Science.gov (United States)

    Brokken, L J S; Rylander, L; Jönsson, B A; Spanò, M; Pedersen, H S; Ludwicki, J K; Zviezdai, V; Bizzaro, D; Manicardi, G C; Toft, G; Bonde, J P; Giwercman, A; Lundberg Giwercman, Y

    2013-05-06

    Recently the dogma that there is an inverse linear association between androgen receptor (AR) CAG and GGN polymorphisms and receptor activity has been challenged. We analysed the pattern of association between 21 male reproductive phenotypes and AR CAG/GGN repeat lengths in 557 proven-fertile men. A linear association was only found between sperm DNA fragmentation index (DFI) and CAG length, and between inhibin B and GGN length. Men with longer CAG then the reference (22-24), had higher oestradiol levels, whereas men with shorter CAG stretches had a higher DFI and a higher proportion of Fas-positive germ cells. Subjects with either short or long CAG had increased seminal levels of prostate-specific antigen and neutral α-glucosidase activity. Compared to men with the median GGN length of 23, those with shorter GGN repeats had higher levels of inhibin B, higher proportions of normal and progressive sperm, and a higher fraction of Fas-positive sperm, while men with longer GGN had higher oestradiol levels. These data indicate that at least for some markers of male reproductive function the association with CAG or GGN repeat length is curvilinear.

  5. Dominant effects of the Huntington's disease HTT CAG repeat length are captured in gene-expression data sets by a continuous analysis mathematical modeling strategy.

    Science.gov (United States)

    Lee, Jong-Min; Galkina, Ekaterina I; Levantovsky, Rachel M; Fossale, Elisa; Anne Anderson, Mary; Gillis, Tammy; Srinidhi Mysore, Jayalakshmi; Coser, Kathryn R; Shioda, Toshi; Zhang, Bin; Furia, Matthew D; Derry, Jonathan; Kohane, Isaac S; Seong, Ihn Sik; Wheeler, Vanessa C; Gusella, James F; MacDonald, Marcy E

    2013-08-15

    In Huntington's disease (HD), the size of the expanded HTT CAG repeat mutation is the primary driver of the processes that determine age at onset of motor symptoms. However, correlation of cellular biochemical parameters also extends across the normal repeat range, supporting the view that the CAG repeat represents a functional polymorphism with dominant effects determined by the longer allele. A central challenge to defining the functional consequences of this single polymorphism is the difficulty of distinguishing its subtle effects from the multitude of other sources of biological variation. We demonstrate that an analytical approach based upon continuous correlation with CAG size was able to capture the modest (∼21%) contribution of the repeat to the variation in genome-wide gene expression in 107 lymphoblastoid cell lines, with alleles ranging from 15 to 92 CAGs. Furthermore, a mathematical model from an iterative strategy yielded predicted CAG repeat lengths that were significantly positively correlated with true CAG allele size and negatively correlated with age at onset of motor symptoms. Genes negatively correlated with repeat size were also enriched in a set of genes whose expression were CAG-correlated in human HD cerebellum. These findings both reveal the relatively small, but detectable impact of variation in the CAG allele in global data in these peripheral cells and provide a strategy for building multi-dimensional data-driven models of the biological network that drives the HD disease process by continuous analysis across allelic panels of neuronal cells vulnerable to the dominant effects of the HTT CAG repeat.

  6. Androgen Receptor CAG Repeat Length Is Associated With Body Fat and Serum SHBG in Boys

    DEFF Research Database (Denmark)

    Mouritsen, Annette; Hagen, Casper P; Sørensen, Kaspar;

    2013-01-01

    was to evaluate associations between the AR (CAG)n polymorphism and development of pubic hair, levels of androgens, and body fat content in healthy boys. Methods: A longitudinal study of 78 healthy boys (age 6.2-12.4 years at inclusion) from the COPENHAGEN Puberty Study was conducted with clinical examinations...

  7. The relationship between CAG repeat length and age of onset differs for Huntington's disease patients with juvenile onset or adult onset.

    Science.gov (United States)

    Andresen, J Michael; Gayán, Javier; Djoussé, Luc; Roberts, Simone; Brocklebank, Denise; Cherny, Stacey S; Cardon, Lon R; Gusella, James F; MacDonald, Marcy E; Myers, Richard H; Housman, David E; Wexler, Nancy S

    2007-05-01

    Age of onset for Huntington's disease (HD) varies inversely with the length of the disease-causing CAG repeat expansion in the HD gene. A simple exponential regression model yielded adjusted R-squared values of 0.728 in a large set of Venezuelan kindreds and 0.642 in a North American, European, and Australian sample (the HD MAPS cohort). We present evidence that a two-segment exponential regression curve provides a significantly better fit than the simple exponential regression. A plot of natural log-transformed age of onset against CAG repeat length reveals this segmental relationship. This two-segment exponential regression on age of onset data increases the adjusted R-squared values by 0.012 in the Venezuelan kindreds and by 0.035 in the HD MAPS cohort. Although the amount of additional variance explained by the segmental regression approach is modest, the two slopes of the two-segment regression are significantly different from each other in both the Venezuelan kindreds [F(2, 439) = 11.13, P= 2 x 10(-5)] and in the HD MAPS cohort [F(2, 688) = 38.27, P= 2 x 10(-16)]. In both populations, the influence of each CAG repeat on age of onset appears to be stronger in the adult-onset range of CAG repeats than in the juvenile-onset range.

  8. Androgen receptor gene methylation and exon one CAG repeat length in ovarian cancer: differences from breast cancer.

    Science.gov (United States)

    Kassim, Samar; Zoheiry, Nivan M; Hamed, Wael M; Going, James J; Craft, John A

    2004-07-01

    More than one neoplastic founder clone can exist in benign epithelial tumours. Although theories of clonal selection make pluriclonality appear unlikely in carcinomas, published data do not exclude this possibility. This study looked for evidence of multiclonal X inactivation in ovarian carcinoma using AR methylation as a marker. Fifteen unifocal ovarian carcinomas and 14 multifocal carcinomas all in Scottish patients were studied. One representative formalin-fixed paraffin-embedded tumour block was chosen for each of the former and two for the latter. From each of these 43 tumour blocks three samples each of approximately 10(4) carcinoma cells were obtained by microdissection (129 in all). DNA released by proteinase K digestion was subjected to PCR amplification of the androgen receptor gene AR exon I CAG repeat polymorphism with and without prior digestion with methylation-sensitive restriction enzymes HpaII and HhaI. Complex amplification patterns were consistent with mosaic X inactivation in some ovarian carcinomas but acquired anomalies of AR methylation cannot be excluded. Parallel analysis of other X-linked polymorphic loci would strengthen the inference of clonality status from DNA methylation data in tumour X studies. Strikingly, the number of CAG repeats in the 29 ovarian tumour patients (median 16, range 11 - 20) was substantially fewer than in 34 previously studied breast cancer patients from the same scottish population (median 21, range 14 - 26; P CAG repeat were over-represented in the ovarian cancer patients but not in the breast cancer series. These findings reinforce recent suggestions that AR may have a role in ovarian carcinogenesis.

  9. Corepressor effect on androgen receptor activity varies with the length of the CAG encoded polyglutamine repeat and is dependent on receptor/corepressor ratio in prostate cancer cells.

    Science.gov (United States)

    Buchanan, Grant; Need, Eleanor F; Barrett, Jeffrey M; Bianco-Miotto, Tina; Thompson, Vanessa C; Butler, Lisa M; Marshall, Villis R; Tilley, Wayne D; Coetzee, Gerhard A

    2011-08-01

    The response of prostate cells to androgens reflects a combination of androgen receptor (AR) transactivation and transrepression, but how these two processes differ mechanistically and influence prostate cancer risk and disease outcome remain elusive. Given recent interest in targeting AR transrepressive processes, a better understanding of AR/corepressor interaction and responses is warranted. Here, we used transactivation and interaction assays with wild-type and mutant ARs, and deletion AR fragments, to dissect the relationship between AR and the corepressor, silencing mediator for retinoic acid and thyroid hormone receptors (SMRT). We additionally tested how these processes are influenced by AR agonist and antagonist ligands, as well as by variation in the polyglutamine tract in the AR amino terminal domain (NTD), which is encoded by a polymorphic CAG repeat in the gene. SMRT was recruited to the AR ligand binding domain by agonist ligand, and as determined by the effect of strategic mutations in activation function 2 (AF-2), requires a precise conformation of that domain. A distinct region of SMRT also mediated interaction with the AR-NTD via the transactivation unit 5 (TAU5; residues 315-538) region. The degree to which SMRT was able to repress AR increased from 17% to 56% as the AR polyglutamine repeat length was increased from 9 to 42 residues, but critically this effect could be abolished by increasing the SMRT:AR molar ratio. These data suggest that the extent to which the CAG encoded polyglutamine repeat influences AR activity represents a balance between corepressor and coactivator occupancy of the same ligand-dependent and independent AR interaction surfaces. Changes in the homeostatic relationship of AR to these molecules, including SMRT, may explain the variable penetrance of the CAG repeat and the loss of AR signaling flexibility in prostate cancer progression.

  10. Late-onset Huntington disease with intermediate CAG repeats: true or false?

    NARCIS (Netherlands)

    Groen, J.L.; de Bie, R.M.A.; Foncke, E.M.J.; Roos, R.A.C.; Leenders, K.L.; Tijssen, M.A.J.

    2010-01-01

    Huntington disease (HD) is a neurodegenerative disorder associated with an expanded CAG trinucleotide repeat length in the huntingtin gene. 'Intermediate alleles' with 27 to 35 CAG repeats generally do not cause HD but are unstable upon germ-line transmission. Insights in CAG repeat mosaicism and en

  11. Late-onset Huntington disease with intermediate CAG repeats : true or false?

    NARCIS (Netherlands)

    Groen, Justus L.; de Bie, Rob M. A.; Foncke, Elisabeth M. J.; Roos, Raymund A. C.; Leenders, Klaus L.; Tijssen, Marina A. J.

    2010-01-01

    Huntington disease (HD) is a neurodegenerative disorder associated with an expanded CAG trinucleotide repeat length in the huntingtin gene. 'Intermediate alleles' with 27 to 35 CAG repeats generally do not cause HD but are unstable upon germ-line transmission. Insights in CAG repeat mosaicism and en

  12. Intermediate CAG repeat lengths (53,54) for MJD/SCA3 are associated with an abnormal phenotype

    NARCIS (Netherlands)

    van Alfen, N; Sinke, R J; Zwarts, M J; Gabreëls-Festen, A; Praamstra, P; Kremer, B P; Horstink, M W

    2001-01-01

    We report on a Dutch family in which 4 members in 2 generations have intermediate repeat lengths (53 and 54) for Machado-Joseph Disease/Spinocerebellar Ataxia (MJD/SCA3). All but the youngest have a restless legs syndrome with fasciculations and a sensorimotor axonal polyneuropathy. Central neurolog

  13. Quantification of age-dependent somatic CAG repeat instability in Hdh CAG knock-in mice reveals different expansion dynamics in striatum and liver.

    Directory of Open Access Journals (Sweden)

    Jong-Min Lee

    Full Text Available BACKGROUND: Age at onset of Huntington's disease (HD is largely determined by the CAG trinucleotide repeat length in the HTT gene. Importantly, the CAG repeat undergoes tissue-specific somatic instability, prevalent in brain regions that are disease targets, suggesting a potential role for somatic CAG repeat instability in modifying HD pathogenesis. Thus, understanding underlying mechanisms of somatic CAG repeat instability may lead to discoveries of novel therapeutics for HD. Investigation of the dynamics of the CAG repeat size changes over time may provide insights into the mechanisms underlying CAG repeat instability. METHODOLOGY/PRINCIPAL FINDINGS: To understand how the HTT CAG repeat length changes over time, we quantified somatic instability of the CAG repeat in Huntington's disease CAG knock-in mice from 2-16 months of age in liver, striatum, spleen and tail. The HTT CAG repeat in spleen and tail was very stable, but that in liver and striatum expanded over time at an average rate of one CAG per month. Interestingly, the patterns of repeat instability were different between liver and striatum. Unstable CAG repeats in liver repeatedly gained similar sizes of additional CAG repeats (approximately two CAGs per month, maintaining a distinct population of unstable repeats. In contrast, unstable CAG repeats in striatum gained additional repeats with different sizes resulting in broadly distributed unstable CAG repeats. Expanded CAG repeats in the liver were highly enriched in polyploid hepatocytes, suggesting that the pattern of liver instability may reflect the restriction of the unstable repeats to a unique cell type. CONCLUSIONS/SIGNIFICANCE: Our results are consistent with repeat expansion occurring as a consequence of recurrent small repeat insertions that differ in different tissues. Investigation of the specific mechanisms that underlie liver and striatal instability will contribute to our understanding of the relationship between

  14. CAG trinucleotide RNA repeats interact with RNA-binding proteins

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, B.A.; Eberwine, J.; Spencer, C. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1996-09-01

    Genes associated with several neurological diseases are characterized by the presence of an abnormally long trinucleotide repeat sequence. By way of example, Huntington`s disease (HD), is characterized by selective neuronal degeneration associated with the expansion of a polyglutamine-encoding CAG tract. Normally, this CAG tract is comprised of 11-34 repeats, but in HD it is expanded to >37 repeats in affected individuals. The mechanism by which CAG repeats cause neuronal degeneration is unknown, but it has been speculated that the expansion primarily causes abnormal protein functioning, which in turn causes HD pathology. Other mechanisms, however, have not been ruled out. Interactions between RNA and RNA-binding proteins have previously been shown to play a role in the expression of several eukaryotic genes. Herein, we report the association of cytoplasmic proteins with normal length and extended CAG repeats, using gel shift and LJV crosslinking assays. Cytoplasmic protein extracts from several rat brain regions, including the striatum and cortex, sites of neuronal degeneration in HD, contain a 63-kD RNA-binding protein that specifically interacts with these CAG-repeat sequences. These protein-RNA interactions are dependent on the length of the CAG repeat, with longer repeats binding substantially more protein. Two CAG repeat-binding proteins are present in human cortex and striatum; one comigrates with the rat protein at 63 kD, while the other migrates at 49 kD. These data suggest mechanisms by which RNA-binding proteins may be involved in the pathological course of trinucleotide repeat-associated neurological diseases. 47 refs., 5 figs.

  15. In Vitro Expansion of CAG, CAA, and Mixed CAG/CAA Repeats

    Directory of Open Access Journals (Sweden)

    Grzegorz Figura

    2015-08-01

    Full Text Available Polyglutamine diseases, including Huntington’s disease and a number of spinocerebellar ataxias, are caused by expanded CAG repeats that are located in translated sequences of individual, functionally-unrelated genes. Only mutant proteins containing polyglutamine expansions have long been thought to be pathogenic, but recent evidence has implicated mutant transcripts containing long CAG repeats in pathogenic processes. The presence of two pathogenic factors prompted us to attempt to distinguish the effects triggered by mutant protein from those caused by mutant RNA in cellular models of polyglutamine diseases. We used the SLIP (Synthesis of Long Iterative Polynucleotide method to generate plasmids expressing long CAG repeats (forming a hairpin structure, CAA-interrupted CAG repeats (forming multiple unstable hairpins or pure CAA repeats (not forming any secondary structure. We successfully modified the original SLIP protocol to generate repeats of desired length starting from constructs containing short repeat tracts. We demonstrated that the SLIP method is a time- and cost-effective approach to manipulate the lengths of expanded repeat sequences.

  16. CAG Repeat Number in the Androgen Receptor Gene and Prostate Cancer.

    Science.gov (United States)

    Madjunkova, S; Eftimov, A; Georgiev, V; Petrovski, D; Dimovski, Aj; Plaseska-Karanfilska, D

    2012-06-01

    Prostate cancer (PC) is the second leading cause of cancer deaths in men. The effects of androgens on prostatic tissue are mediated by the androgen receptor (AR) gene. The 5' end of exon 1 of the AR gene includes a polymorphic CAG triplet repeat that numbers between 10 to 36 in the normal population. The length of the CAG repeats is inversely related to the transactivation function of the AR gene. There is controversy over association between short CAG repeat numbers in the AR gene and PC. This retrospective case-control study evaluates the possible effect of short CAG repeats on the AR gene in prostate cancer risk in Macedonian males. A total of 392 male subjects, 134 PC patients, 106 patients with benign prostatic hyperplasia (BPH) and 152 males from the general Macedonian population were enrolled in this study. The CAG repeat length was determined by fluorescent polymerase chain reaction (PCR) amplification of exon1 of the AR gene followed by capillary electrophoresis (CE) on a genetic analyzer. The mean repeat length in PC patients was 21.5 ± 2.65, in controls 22.28 ± 2.86 (p = 0.009) and in BPH patients 22.1 ± 2.52 (p = 0.038). Short CAG repeats (CAG repeat (CAG repeat length. These results suggest that reduced CAG repeat length may be associated with increased prostate cancer risk in Macedonian men.

  17. Cytogenetic and molecular analysis of the Y chromosome: absence of a significant relationship between CAG repeat length in exon 1 of the androgen receptor gene and infertility in Indian men.

    Science.gov (United States)

    Dhillon, Varinderpal S; Husain, Syed A

    2003-10-01

    The genetic basis of male infertility remains unclear in the majority of cases. Recent studies have indicated an association between microdeletions of the azoospermia factor a (AZFa)-AZFc regions of Yq and severe oligospermia or azoospermia. Increased (CAG)n repeat lengths in the androgen receptor (AR) gene have also been reported in infertile men. Therefore, in order to assess the prevalence of these genetic defects to male infertility, 183 men with non-obstructive azoospermia (n = 70), obstructive azoospermia (n = 33), severe oligospermia (n = 80) and 59 fertile men were examined cytogenetically and at molecular level for Yq deletions, microdeletions, and AR-CAG repeat lengths along with hormonal profiles [luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone (T)]. We used high resolution cytogenetics to detect chromosome deletions and multiplex polymerase chain reaction (PCR) involving 27 sequence-tagged site (STS) markers on Yq to determine the rate and extent of Yq microdeletions. PCR amplification with primers flanking exon 1 of AR gene was used to determine the AR-(CAG)n repeat lengths. Hormonal profiles (LH, FSH and T levels) were also analysed in infertile and fertile men. Testicular biopsies showed Sertoli cell only (SCO) morphology, maturation arrests (MA) and hypospermatogenesis. No chromosome aberrations were found in infertile men but there was a significant increase (p CAG repeats in AR gene was observed between infertile and fertile men (22.2 +/- 1.5 and 21.5 +/- 1.4 respectively). No significant increase or decrease in levels of LH, FSH and T was observed in infertile and fertile men. In some infertile men, significantly elevated levels of FSH alone or in combination with LH were found to be indicative of failure of spermatogenesis and/or suggestive of testicular failure. Y-chromosome microdeletions contribute to infertility in some patients but no relationship could be established with the (CAG)n repeat lengths in exon 1 of

  18. Gene expression profiling of R6/2 transgenic mice with different CAG repeat lengths reveals genes associated with disease onset and progression in Huntington's disease.

    Science.gov (United States)

    Tang, Bin; Seredenina, Tamara; Coppola, Giovanni; Kuhn, Alexandre; Geschwind, Daniel H; Luthi-Carter, Ruth; Thomas, Elizabeth A

    2011-06-01

    R6/2 transgenic mice with expanded CAG repeats (>300) have a surprisingly prolonged disease progression and longer lifespan than prototypical parent R6/2 mice (carrying 150 CAGs); however, the mechanism of this phenotype amelioration is unknown. We compared gene expression profiles in the striatum of R6/2 transgenic mice carrying ~300 CAG repeats (R6/2(Q300) transgenic mice) to those carrying ~150 CAG repeats (R6/2(Q150) transgenic mice) and littermate wildtype controls in order to identify genes that may play determinant roles in the time course of phenotypic expression in these mice. Of the top genes showing concordant expression changes in the striatum of both R6/2 lines, 85% were decreased in expression, while discordant expression changes were observed mostly for genes upregulated in R6/2(Q300) transgenic mice. Upregulated genes in the R6/2(Q300) mice were associated with the ubiquitin ligase complex, cell adhesion, protein folding, and establishment of protein localization. We qPCR-validated increases in expression of genes related to the latter category, including Lrsam1, Erp29, Nasp, Tap1, Rab9b, and Pfdn5 in R6/2(Q300) mice, changes that were not observed in R6/2 mice with shorter CAG repeats, even in late stages (i.e., 12 weeks of age). We further tested Lrsam1 and Erp29, the two genes showing the greatest upregulation in R6/2(Q300) transgenic mice, for potential neuroprotective effects in primary striatal cultures overexpressing a mutated human huntingtin (htt) fragment. Overexpression of Lrsam1 prevented the loss of NeuN-positive cell bodies in htt171-82Q cultures, concomitant with a reduction of nuclear htt aggregates. Erp29 showed no significant effects in this model. This is consistent with the distinct pattern of htt inclusion localization observed in R6/2(Q300) transgenic mice, in which smaller cytoplasmic inclusions represent the major form of insoluble htt in the cell, as opposed to large nuclear inclusions observed in R6/2(Q150) transgenic mice

  19. Long CAG repeat sequence and protein expression of androgen receptor considered as prognostic indicators in male breast carcinoma.

    Directory of Open Access Journals (Sweden)

    Yan-Ni Song

    Full Text Available BACKGROUND: The androgen receptor (AR expression and the CAG repeat length within the AR gene appear to be involved in the carcinogenesis of male breast carcinoma (MBC. Although phenotypic differences have been observed between MBC and normal control group in AR gene, there is lack of correlation analysis between AR expression and CAG repeat length in MBC. The purpose of the study was to investigate the prognostic value of CAG repeat lengths and AR protein expression. METHODS: 81 tumor tissues were used for immunostaining for AR expression and CAG repeat length determination and 80 normal controls were analyzed with CAG repeat length in AR gene. The CAG repeat length and AR expression were analyzed in relation to clinicopathological factors and prognostic indicators. RESULTS: AR gene in many MBCs has long CAG repeat sequence compared with that in control group (P = 0.001 and controls are more likely to exhibit short CAG repeat sequence than MBCs. There was statistically significant difference in long CAG repeat sequence between AR status for MBC patients (P = 0.004. The presence of long CAG repeat sequence and AR-positive expression were associated with shorter survival of MBC patients (CAG repeat: P = 0.050 for 5y-OS; P = 0.035 for 5y-DFS AR status: P = 0.048 for 5y-OS; P = 0.029 for 5y-DFS, respectively. CONCLUSION: The CAG repeat length within the AR gene might be one useful molecular biomarker to identify males at increased risk of breast cancer development. The presence of long CAG repeat sequence and AR protein expression were in relation to survival of MBC patients. The CAG repeat length and AR expression were two independent prognostic indicators in MBC patients.

  20. Instability of human TATA-binding protein CAG triplet repeats during amplification by PCR.

    Science.gov (United States)

    Holstege, F C; van der Vliet, P C; Timmers, H T

    1994-09-13

    Polymerase chain reaction (PCR) of a TATA-binding protein cDNA that contains CAG triplet repeats results in heterogeneous products. This is caused by a variable loss in the number of CAG triplets. Sequence analysis of PCR products suggests that instability increases with repeat length.

  1. CAG-encoded polyglutamine length polymorphism in the human genome

    Directory of Open Access Journals (Sweden)

    Hayden Michael R

    2007-05-01

    Full Text Available Abstract Background Expansion of polyglutamine-encoding CAG trinucleotide repeats has been identified as the pathogenic mutation in nine different genes associated with neurodegenerative disorders. The majority of individuals clinically diagnosed with spinocerebellar ataxia do not have mutations within known disease genes, and it is likely that additional ataxias or Huntington disease-like disorders will be found to be caused by this common mutational mechanism. We set out to determine the length distributions of CAG-polyglutamine tracts for the entire human genome in a set of healthy individuals in order to characterize the nature of polyglutamine repeat length variation across the human genome, to establish the background against which pathogenic repeat expansions can be detected, and to prioritize candidate genes for repeat expansion disorders. Results We found that repeats, including those in known disease genes, have unique distributions of glutamine tract lengths, as measured by fragment analysis of PCR-amplified repeat regions. This emphasizes the need to characterize each distribution and avoid making generalizations between loci. The best predictors of known disease genes were occurrence of a long CAG-tract uninterrupted by CAA codons in their reference genome sequence, and high glutamine tract length variance in the normal population. We used these parameters to identify eight priority candidate genes for polyglutamine expansion disorders. Twelve CAG-polyglutamine repeats were invariant and these can likely be excluded as candidates. We outline some confusion in the literature about this type of data, difficulties in comparing such data between publications, and its application to studies of disease prevalence in different populations. Analysis of Gene Ontology-based functions of CAG-polyglutamine-containing genes provided a visual framework for interpretation of these genes' functions. All nine known disease genes were involved in DNA

  2. Association between CAG repeat polymorphisms and the risk of prostate cancer: a meta-analysis by race, study design and the number of (CAG)n repeat polymorphisms.

    Science.gov (United States)

    Sun, Jun-Hyun; Lee, Sang-Ah

    2013-11-01

    Although a number of studies have been conducted on the association between prostate cancer and CAG repeat polymorphisms of the androgen receptor gene, this association remains elusive and controversial. In this meta-analysis, we aimed to evaluate the effects of (CAG)n repeat genetic polymorphisms on the incidence of prostate cancer, particularly as regards race, study design and the number of (CAG)n repeats. To collect articles published on the association between CAG repeats and prostate cancer, publications were identified from the National Center for Biotechnology Information (NCBI) database of epidemiological studies published up to October 2011; our identification of publications was not limited by a language barrier. The following search keywords were used: prostate cancer risk, CAG repeat polymorphism, androgen receptor gene and human. Stata version 10 was used for the meta-analysis and the publication bias was measured through the Begg's test and Egger's test. This meta-analysis included 47 studies with 13,346 cases and 15,172 control or non-cases and consisted of 31 reports based on Caucasians, ten on Asians, one on Hispanics and four on combined ethnic groups. The carriers of a shorter CAG repeat sequence had an increased risk of prostate cancer (OR 1.21, 95% CI 1.10-1.34 for all subjects; OR 1.21, 95% CI 1.10-1.34 for prospective studies; OR 1.32, 95% CI 1.15-1.51 for retrospective studies) regardless of the exact length of the CAG repeat, compared with carriers of a longer repeat sequence. In terms of race, the risk of carrying a shorter CAG repeat sequence was 1.10- and 1.83-fold higher than that of a longer repeat sequence in Caucasians and Asians, respectively. For the specific number of CAG repeat polymorphisms, carriers of repeats were observed to have a higher risk of prostate cancer (OR 1.16, 95% CI 1.04-1.29) compared with carriers with ≥ 22 CAG repeat polymorphisms, particularly for Asians (OR 2.06, 95% CI 1.00-4.24). This meta

  3. Studies of the CAG repeat in the Machado-Joseph disease gene in Taiwan.

    Science.gov (United States)

    Hsieh, M; Tsai, H F; Lu, T M; Yang, C Y; Wu, H M; Li, S Y

    1997-08-01

    Machado-Joseph disease (MJD) is an autosomal dominant spinocerebellar degeneration characterized by cerebellar ataxia and pyramidal signs associated in varying degrees with a dystonic-rigid extrapyramidal syndrome or peripheral amyotrophy. Unstable CAG trinucleotide repeat expansion in the MJD gene on the long arm of chromosome 14 has been identified as the pathological mutation for MJD. While investigating the distribution of CAG repeat lengths of the MJD gene in Taiwan's population, we have identified 18 MJD-affected patients and 12 at-risk individuals in seven families. In addition, we have analyzed the range of CAG repeat lengths in 96 control individuals. The CAG repeat number ranged from 13 to 44 in the controls and 72-85 in the affected and at-risk individuals. Our results indicated that the CAG repeat number was inversely correlated with the age of onset. The differences in CAG repeat length between parent and child and between siblings are greater with paternal transmission than maternal transmission. Our data show a tendency towards the phenomenon of anticipation in the MJD families but do not support unidirectional expansion of CAG repeats during transmission. We also demonstrated that PCR amplification of the CAG repeats in the MJD gene from villous DNA was possible and might prove useful as a diagnostic tool for affected families in the future.

  4. Polymorphic CAG Repeat and Protein Expression of Androgen Receptor Gene in Colorectal Cancer.

    Science.gov (United States)

    Huang, Rui; Wang, Guiyu; Song, Yanni; Wang, Feng; Zhu, Bing; Tang, Qingchao; Liu, Zheng; Chen, Yinggang; Zhang, Qian; Muhammad, Shan; Wang, Xishan

    2015-04-01

    Although somatic alterations in CAG repeats in the androgen receptor (AR) gene have been suggested to predispose to colorectal cancer, less is known about AR in colorectal cancer carcinogenesis. Because of lack of relevant analysis on CAG repeat length and AR expression in colorectal cancer, we aimed to investigate the prognostic value of polymorphic CAG and protein expression of the AR gene in patients with colorectal cancer. A case-control study was carried out on 550 patients with colorectal cancer and 540 healthy controls to investigate whether polymorphic CAG within the AR gene is linked to increased risk for colorectal cancer. Polymorphic CAG and AR expression were analyzed to clarify their relationship with clinicopathologic and prognostic factors in patients with colorectal cancer. The study showed that the AR gene in patients with colorectal cancer had a longer CAG repeat sequence than those in the control group, as well as increased risk for colorectal cancer among females (P = 0.013), males (P = 0.002), and total colorectal cancer population (P CAG repeat sequence among males (P CAG repeat sequence and negative AR expression were associated with a short 5-year overall survival (OS) rate in colorectal cancer. Long CAG repeat sequences and the absence of AR expression were closely related to the development of colorectal cancer. Both long CAG and decreased AR expression were correlated with the poor 5-year OS in patients with colorectal cancer.

  5. Long CAG Repeat Sequence and Protein Expression of Androgen Receptor Considered as Prognostic Indicators in Male Breast Carcinoma

    OpenAIRE

    Yan-Ni Song; Jing-Shu Geng; Tong Liu; Zhen-Bin Zhong; Yang Liu; Bing-Shu Xia; Hong-Fei Ji; Xiao-Mei Li; Guo-Qiang Zhang; Yan-Lv Ren; Zhi-Gao Li; Da Pang

    2012-01-01

    BACKGROUND: The androgen receptor (AR) expression and the CAG repeat length within the AR gene appear to be involved in the carcinogenesis of male breast carcinoma (MBC). Although phenotypic differences have been observed between MBC and normal control group in AR gene, there is lack of correlation analysis between AR expression and CAG repeat length in MBC. The purpose of the study was to investigate the prognostic value of CAG repeat lengths and AR protein expression. METHODS: 81 tumor tiss...

  6. GFP-based fluorescence assay for CAG repeat instability in cultured human cells.

    Directory of Open Access Journals (Sweden)

    Beatriz A Santillan

    Full Text Available Trinucleotide repeats can be highly unstable, mutating far more frequently than point mutations. Repeats typically mutate by addition or loss of units of the repeat. CAG repeat expansions in humans trigger neurological diseases that include myotonic dystrophy, Huntington disease, and several spinocerebellar ataxias. In human cells, diverse mechanisms promote CAG repeat instability, and in mice, the mechanisms of instability are varied and tissue-dependent. Dissection of mechanistic complexity and discovery of potential therapeutics necessitates quantitative and scalable screens for repeat mutation. We describe a GFP-based assay for screening modifiers of CAG repeat instability in human cells. The assay exploits an engineered intronic CAG repeat tract that interferes with expression of an inducible GFP minigene. Like the phenotypes of many trinucleotide repeat disorders, we find that GFP function is impaired by repeat expansion, in a length-dependent manner. The intensity of fluorescence varies inversely with repeat length, allowing estimates of repeat tract changes in live cells. We validate the assay using transcription through the repeat and engineered CAG-specific nucleases, which have previously been reported to induce CAG repeat instability. The assay is relatively fast and should be adaptable to large-scale screens of chemical and shRNA libraries.

  7. Huntington's disease as caused by 34 CAG repeats.

    Science.gov (United States)

    Andrich, Jürgen; Arning, Larissa; Wieczorek, Stefan; Kraus, Peter H; Gold, Ralf; Saft, Carsten

    2008-04-30

    Huntington's disease (HD) is an autosomal dominantly inherited neurodegenerative disorder caused by an abnormal expansion of a polymorphic stretch of CAG repeats in the coding 5' part of the HD gene on chromosome 4p. Expansions of CAG blocks beyond 35 repeats are associated with the clinical presentation of HD. There is an intermediate range of rare alleles between 27 and 35 CAG repeats with a higher risk for further expansion in subsequent generations. Here, we report a 75-year-old male with clinical features of HD and 34 CAG repeat units.

  8. Shorter CAG repeat in the AR gene is associated with atypical hyperplasia and breast carcinoma

    DEFF Research Database (Denmark)

    De Abreu, Francine Blumental; Pirolo, Leandro Júnior; Canevari, Renata de Azevedo

    2007-01-01

    -based GeneScan analysis was used to investigate the [CAG]n repeat length at exon 1 of the AR gene in 59 benign breast lesions (27 fibroadenomas, 18 atypical hyperplasias, and 14 hyperplasias without atypia) and 54 ductal breast carcinomas. Seventy-two cancer-free women were used as a control group....... In addition, [CAG]n repeats were evaluated for the presence of loss of heterozygosity (LOH) and microsatellite instability (MSI) in a subset of these samples (27 fibroadenomas, 14 hyperplasias without atypia and 22 breast carcinomas). RESULTS: Shorter [CAG]n repeat lengths were strongly correlated...

  9. Intergenerational and striatal CAG repeat instability in Huntington's disease knock-in mice involve different DNA repair genes.

    Science.gov (United States)

    Dragileva, Ella; Hendricks, Audrey; Teed, Allison; Gillis, Tammy; Lopez, Edith T; Friedberg, Errol C; Kucherlapati, Raju; Edelmann, Winfried; Lunetta, Kathryn L; MacDonald, Marcy E; Wheeler, Vanessa C

    2009-01-01

    Modifying the length of the Huntington's disease (HD) CAG repeat, the major determinant of age of disease onset, is an attractive therapeutic approach. To explore this we are investigating mechanisms of intergenerational and somatic HD CAG repeat instability. Here, we have crossed HD CAG knock-in mice onto backgrounds deficient in mismatch repair genes, Msh3 and Msh6, to discern the effects on CAG repeat size and disease pathogenesis. We find that different mechanisms predominate in inherited and somatic instability, with Msh6 protecting against intergenerational contractions and Msh3 required both for increasing CAG length and for enhancing an early disease phenotype in striatum. Therefore, attempts to decrease inherited repeat size may entail a full understanding of Msh6 complexes, while attempts to block the age-dependent increases in CAG size in striatal neurons and to slow the disease process will require a full elucidation of Msh3 complexes and their function in CAG repeat instability.

  10. ATXN2 CAG repeat expansions increase the risk for Chinese patients with amyotrophic lateral sclerosis.

    Science.gov (United States)

    Liu, Xiaolu; Lu, Ming; Tang, Lu; Zhang, Nan; Chui, Dehua; Fan, Dongsheng

    2013-09-01

    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder with unclear etiology. Recently, intermediate CAG repeat expansions in ATXN2, the gene responsible for spinocerebellar ataxia type 2 (SCA2), have been identified as a possible genetic risk factor for ALS. In this study, we analyzed the ATXN2 CAG repeat length in Chinese patients with ALS to evaluate the relationship between the genotype and phenotype. We studied 1,067 patients with ALS and 506 controls from mainland China (excluding Tibet). We collected clinical data and analyzed fluorescent PCR products to assess ATXN2 CAG repeat length in all of the samples. We observed that intermediate CAG repeat expansions in ATXN2 (CAG repeat length >30) were associated with ALS (p = 0.004). There was no significant difference in clinical characteristics between the groups with and without intermediate CAG repeat expansions in ATXN2. Our data indicate that, for ALS patients from mainland China, intermediate CAG repeat expansions in ATXN2 increase the risk of ALS but have no effect on disease phenotype.

  11. A pathogenic mechanism in Huntington's disease involves small CAG-repeated RNAs with neurotoxic activity.

    Science.gov (United States)

    Bañez-Coronel, Mónica; Porta, Silvia; Kagerbauer, Birgit; Mateu-Huertas, Elisabet; Pantano, Lorena; Ferrer, Isidre; Guzmán, Manuel; Estivill, Xavier; Martí, Eulàlia

    2012-01-01

    Huntington's disease (HD) is an autosomal dominantly inherited disorder caused by the expansion of CAG repeats in the Huntingtin (HTT) gene. The abnormally extended polyglutamine in the HTT protein encoded by the CAG repeats has toxic effects. Here, we provide evidence to support that the mutant HTT CAG repeats interfere with cell viability at the RNA level. In human neuronal cells, expanded HTT exon-1 mRNA with CAG repeat lengths above the threshold for complete penetrance (40 or greater) induced cell death and increased levels of small CAG-repeated RNAs (sCAGs), of ≈21 nucleotides in a Dicer-dependent manner. The severity of the toxic effect of HTT mRNA and sCAG generation correlated with CAG expansion length. Small RNAs obtained from cells expressing mutant HTT and from HD human brains significantly decreased neuronal viability, in an Ago2-dependent mechanism. In both cases, the use of anti-miRs specific for sCAGs efficiently blocked the toxic effect, supporting a key role of sCAGs in HTT-mediated toxicity. Luciferase-reporter assays showed that expanded HTT silences the expression of CTG-containing genes that are down-regulated in HD. These results suggest a possible link between HD and sCAG expression with an aberrant activation of the siRNA/miRNA gene silencing machinery, which may trigger a detrimental response. The identification of the specific cellular processes affected by sCAGs may provide insights into the pathogenic mechanisms underlying HD, offering opportunities to develop new therapeutic approaches.

  12. Prevalence of Huntington's disease gene CAG repeat alleles in sporadic amyotrophic lateral sclerosis patients.

    Science.gov (United States)

    Ramos, Eliana Marisa; Keagle, Pamela; Gillis, Tammy; Lowe, Patrick; Mysore, Jayalakshmi S; Leclerc, Ashley Lyn; Ratti, Antonia; Ticozzi, Nicola; Gellera, Cinzia; Gusella, James F; Silani, Vincenzo; Alonso, Isabel; Brown, Robert H; MacDonald, Marcy E; Landers, John E

    2012-05-01

    A higher prevalence of intermediate ataxin-2 CAG repeats in amyotrophic lateral sclerosis (ALS) patients has raised the possibility that CAG expansions in other polyglutamine disease genes could contribute to ALS neurodegeneration. We sought to determine whether expansions of the CAG repeat of the HTT gene that causes Huntington's disease, are associated with ALS. We compared the HTT CAG repeat length on a total of 3144 chromosomes from 1572 sporadic ALS patients and 4007 control chromosomes, and also tested its possible effects on ALS-specific parameters, such as age and site of onset and survival rate. Our results show that the CAG repeat in the HTT gene is not a risk factor for ALS nor modifies its clinical presentation. These findings suggest that distinct neuronal degeneration processes are involved in these two different neurodegenerative disorders.

  13. Verification of somatic CAG repeat expansion by pre-PCR fractionation.

    Science.gov (United States)

    Hunter, Jesse M; Crouse, Andrew B; Lesort, Mathieu; Johnson, Gail V W; Detloff, Peter J

    2005-05-15

    The inheritance of a long CAG repeat causes several late onset neurological disorders including Huntington's disease (HD). Longer CAG repeats correlate with earlier onset of HD suggesting an increased toxicity for the products of long repeat alleles. PCR based data has been used to show that HD CAG repeat expansion beyond the inherited length occurs in affected tissues indicating a possible role for somatic instability in the disease process. PCR, however, is prone to artifacts resulting from expansion of repeat sequences during amplification. We describe a method to distinguish between CAG repeat expansions that exist in vivo and those that potentially occur during PCR. The method involves size fractionation of genomic restriction fragments containing the expanded repeats followed by PCR amplification. The application of this method confirms the presence of somatic expansions in the brains of a knock-in mouse model of HD.

  14. An Expanded CAG Repeat in Huntingtin Causes +1 Frameshifting.

    Science.gov (United States)

    Saffert, Paul; Adamla, Frauke; Schieweck, Rico; Atkins, John F; Ignatova, Zoya

    2016-08-26

    Maintenance of triplet decoding is crucial for the expression of functional protein because deviations either into the -1 or +1 reading frames are often non-functional. We report here that expression of huntingtin (Htt) exon 1 with expanded CAG repeats, implicated in Huntington pathology, undergoes a sporadic +1 frameshift to generate from the CAG repeat a trans-frame AGC repeat-encoded product. This +1 recoding is exclusively detected in pathological Htt variants, i.e. those with expanded repeats with more than 35 consecutive CAG codons. An atypical +1 shift site, UUC C at the 5' end of CAG repeats, which has some resemblance to the influenza A virus shift site, triggers the +1 frameshifting and is enhanced by the increased propensity of the expanded CAG repeats to form a stem-loop structure. The +1 trans-frame-encoded product can directly influence the aggregation of the parental Htt exon 1.

  15. CAG Repeat Number in the Androgen Receptor Gene and Prostate Cancer

    OpenAIRE

    Madjunkova, S.; Eftimov, A.; Georgiev, V.; Petrovski, D; Dimovski, AJ; Plaseska-Karanfilska, D

    2012-01-01

    Prostate cancer (PC) is the second leading cause of cancer deaths in men. The effects of androgens on prostatic tissue are mediated by the androgen receptor (AR) gene. The 5′ end of exon 1 of the AR gene includes a polymorphic CAG triplet repeat that numbers between 10 to 36 in the normal population. The length of the CAG repeats is inversely related to the transactivation function of the AR gene. There is controversy over association between short CAG repeat numbers in the AR gene and PC. Th...

  16. Analysis of CAG repeats in IT15 gene in Spanish population

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, A.; Castellvi-Pel, S.; Mila, M. [Hospital Clinic i Provincial de Parcelons (Spain)] [and others

    1994-09-01

    Huntington`s disease (HD) is an autosomal dominant neurodegenerative disorder characterized by involuntary movements, and cognitive and affective changes. HD has a prevalence of 1 in 10,000 individuals in most populations of European origin. The IT15 gene is responsible for HD as it contains a highly polymorphic, unstable (CAG) repeated sequence that is abnormally expanded in HD chromosomes. The IT15 (CAG)n stretch was analyzed in 100 members (50 affected individuals, 40 asymptomatic at risk for HD, and 10 unaffected members) of 50 HD families, and 50 individuals of the general Spanish population. Expansion of the CAG repeat sequence was found in 45 affected members and 14 individuals at risk, with a repeat length of 40 to 85 repeat units. The range of the polymorphic CAG repeat in normal chromosomes was between 11 and 31 repeat units. In the families with several affected members, we found increases of the repeat length in the least generation. Inverse correlation was found between the age of onset and the length of the CAG repeat; the analysis showed also parental male bias. Presymptomatic analysis of HD has been considerably enhanced with the CAG mutation study.

  17. Unusual structures are present in DNA fragments containing super-long Huntingtin CAG repeats.

    Directory of Open Access Journals (Sweden)

    Daniel Duzdevich

    Full Text Available BACKGROUND: In the R6/2 mouse model of Huntington's disease (HD, expansion of the CAG trinucleotide repeat length beyond about 300 repeats induces a novel phenotype associated with a reduction in transcription of the transgene. METHODOLOGY/PRINCIPAL FINDINGS: We analysed the structure of polymerase chain reaction (PCR-generated DNA containing up to 585 CAG repeats using atomic force microscopy (AFM. As the number of CAG repeats increased, an increasing proportion of the DNA molecules exhibited unusual structural features, including convolutions and multiple protrusions. At least some of these features are hairpin loops, as judged by cross-sectional analysis and sensitivity to cleavage by mung bean nuclease. Single-molecule force measurements showed that the convoluted DNA was very resistant to untangling. In vitro replication by PCR was markedly reduced, and TseI restriction enzyme digestion was also hindered by the abnormal DNA structures. However, significantly, the DNA gained sensitivity to cleavage by the Type III restriction-modification enzyme, EcoP15I. CONCLUSIONS/SIGNIFICANCE: "Super-long" CAG repeats are found in a number of neurological diseases and may also appear through CAG repeat instability. We suggest that unusual DNA structures associated with super-long CAG repeats decrease transcriptional efficiency in vitro. We also raise the possibility that if these structures occur in vivo, they may play a role in the aetiology of CAG repeat diseases such as HD.

  18. CAG repeat expansion in Huntington disease determines age at onset in a fully dominant fashion

    DEFF Research Database (Denmark)

    Lee, J-M; Ramos, E M; Lee, J-H;

    2012-01-01

    Age at onset of diagnostic motor manifestations in Huntington disease (HD) is strongly correlated with an expanded CAG trinucleotide repeat. The length of the normal CAG repeat allele has been reported also to influence age at onset, in interaction with the expanded allele. Due to profound...... implications for disease mechanism and modification, we tested whether the normal allele, interaction between the expanded and normal alleles, or presence of a second expanded allele affects age at onset of HD motor signs....

  19. Nonparametric modeling and analysis of association between Huntington's disease onset and CAG repeats.

    Science.gov (United States)

    Ma, Yanyuan; Wang, Yuanjia

    2014-04-15

    Huntington's disease (HD) is a neurodegenerative disorder with a dominant genetic mode of inheritance caused by an expansion of CAG repeats on chromosome 4. Typically, a longer sequence of CAG repeat length is associated with increased risk of experiencing earlier onset of HD. Previous studies of the association between HD onset age and CAG length have favored a logistic model, where the CAG repeat length enters the mean and variance components of the logistic model in a complex exponential-linear form. To relax the parametric assumption of the exponential-linear association to the true HD onset distribution, we propose to leave both mean and variance functions of the CAG repeat length unspecified and perform semiparametric estimation in this context through a local kernel and backfitting procedure. Motivated by including family history of HD information available in the family members of participants in the Cooperative Huntington's Observational Research Trial (COHORT), we develop the methodology in the context of mixture data, where some subjects have a positive probability of being risk free. We also allow censoring on the age at onset of disease and accommodate covariates other than the CAG length. We study the theoretical properties of the proposed estimator and derive its asymptotic distribution. Finally, we apply the proposed methods to the COHORT data to estimate the HD onset distribution using a group of study participants and the disease family history information available on their family members.

  20. New primer for specific amplification of the CAG repeat in Huntington disease alleles

    Energy Technology Data Exchange (ETDEWEB)

    Bond, C.E.; Hodes, M.E. [Indiana Univ. School of Medicine, Indianapolis (United States)

    1994-09-01

    Huntington disease is an autosomal dominant neurodegenerative disorder caused by an expansion of a CAG trinucleotide repeat near the 5{prime} end of the gene for Huntington disease (IT15). The CAG repeat is flanked by a variable-length CCG repeat that is included in the amplification product obtained with most currently used primer sets and PCR protocols. Inclusion of this adjacent CCG repeat complicates the accurate assessment of CAG repeat length and interferes with the genotype determination of those individuals carrying alleles in the intermediate range between normal and expanded sized. Due to the GC-rich nature of this region, attempts at designing a protocol for amplification of only the CAG repeat have proved unreliable and difficult to execute. We report here the development of a compatible primer set and PCR protocol that yields consistent amplification of the CAG-repeat region. PCR products can be visualized in ethidium bromide-stained agarose gels for rapid screening or in 6% polyacrylamide gels for determination of exact repeat length. This assay produces bands that can be sized accurately, while eliminating most nonspecific products. Fifty-five specimens examined showed consistency with another well-known method, but one that amplifies the CCG repeats as well. The results we obtained also matched the known carrier status of the donors.

  1. Neuropathological diagnosis and CAG repeat expansion in Huntington's disease.

    OpenAIRE

    Xuereb, J H; MacMillan, J C; Snell, R; Davies, P.; Harper, P S

    1996-01-01

    OBJECTIVE--To correlate the degree of CAG repeat expansion with neuropathological findings in Huntington's disease. METHODS--The CAG repeat polymorphism was analysed in a large series of brain samples from 268 patients with a clinical diagnosis of Huntington's disease in which full neuropathological data was available. RESULTS--Analysis by polymerase chain reaction was successful in 63% of samples (169 of 268). Repeat expansions were detected in 152 of 153 (99%) samples with a neuropathologic...

  2. Haplotype analysis in Huntington desease provides insights into mechanisms of CAG repeat expansion

    Energy Technology Data Exchange (ETDEWEB)

    Andrew, S.E.; Goldberg, Y.P.; Squitieri, F. [Univ. of British Columbia, Vancouver (Canada)] [and others

    1994-09-01

    Huntington disease (HD) is one of 7 disorders now known to be caused by expansion of a trinucleotide repeat. The HD mutation is a polymorphic trinucleotide (CAG) repeat in the 5{prime} region of a novel gene that expands beyond the normal range of 10-35 repeats in persons destined to develop the disease. Haplotype analysis of other dynamic mutation disorders such as myotonic dystrophy and Fragil X have suggested that a rare ancestral expansion event on a normal chromosome is followed by subsequent expansion events, resulting in a pool of chromosomes in the premutation range, which is inherently unstable and prone to further multiple expansion events leading to disease range chromosomes. Haplotype analysis of 67 HD and 84 control chromosomes using 5 polymorphic markers, both intragenic and 5{prime} to the disease mutation, demonstrate that multiple haplotypes underlie HD. However, 94% of the chromosomes can be grouped under two major haplotypes. These two haplotypes are also present in the normal population. A third major haplotype is seen on 38% of normal chromosomes but rarely on HD chromosomes (6%). CAG lengths on the normal chromosomes with the two haplotypes seen in the HD population are higher than those seen on the normal chromosomes with the haplotype rarely seen on HD chromosomes. Furthermore, in populations with a diminished frequency of HD, CAG length on normal chromosomes is significantly less than other populations with higher prevalence rates for HD. These data suggest that CAG length on normal chromosomes may be a significant factor contributing to repeat instability that eventually leads to chromosomes with CAG repeat lengths in the HD range. Haplotypes on the HD chromosomes are identical to those normal chromosomes which have CAG lengths in the high range of normal, suggesting that further expansions of this pool of chromosomes leads to chromosomes with CAG repeat sizes within the disease range, consistent with a multistep model.

  3. Germ-line CAG repeat instability causes extreme CAG repeat expansion with infantile-onset spinocerebellar ataxia type 2

    DEFF Research Database (Denmark)

    Vinther-Jensen, Tua; Ek, Jakob; Duno, Morten

    2013-01-01

    The spinocerebellar ataxias (SCA) are a genetically and clinically heterogeneous group of diseases, characterized by dominant inheritance, progressive cerebellar ataxia and diverse extracerebellar symptoms. A subgroup of the ataxias is caused by unstable CAG-repeat expansions in their respective...

  4. How strong is the association between CAG and GGN repeat length polymorphisms in the androgen receptor gene and prostate cancer risk?

    NARCIS (Netherlands)

    Zeegers, M.P.; Kiemeney, L.A.L.M.; Nieder, A.M.; Ostrer, H.

    2004-01-01

    OBJECTIVE: Although narrative reviews have suggested an association between (CAG)n and (GGN)n polymorphisms in the AR gene and prostate cancer, it has never been quantified systematically. The purpose of this meta-analysis was to provide relative and absolute quantitative summary estimates with suff

  5. Regulation of mRNA translation by MID1: a common mechanism of expanded CAG repeat RNAs

    Directory of Open Access Journals (Sweden)

    Nadine Griesche

    2016-10-01

    Full Text Available Expansion of CAG repeats, which code for the disease-causing polyglutamine protein, is a common feature in polyglutamine diseases. RNA-mediated mechanisms that contribute to neuropathology in polyglutamine diseases are important. RNA-toxicity describes a phenomenon by which the mutant CAG repeat RNA recruits RNA-binding proteins, thereby leading to aberrant function. For example the MID1 protein binds to mutant huntingtin (HTT RNA, which is linked to Huntington’s disease (HD, at its CAG repeat region and induces protein synthesis of mutant protein. But is this mechanism specific to HD or is it a common mechanism in CAG repeat expansion disorders? To answer this question, we have analysed the interaction between MID1 and three other CAG repeat mRNAs, Ataxin2 (ATXN2, Ataxin3 (ATXN3, and Ataxin7 (ATXN7, that all differ in the sequence flanking the CAG repeat. We show that ATXN2, ATXN3 and ATXN7 bind to MID1 in a CAG repeat length-dependent manner. Furthermore, we show that functionally, in line with what we have previously observed for HTT, the binding of MID1 to ATXN2, ATXN3 and ATXN7 mRNA induces protein synthesis in a repeat length-dependent manner. Our data suggest that regulation of protein translation by the MID1 complex is a common mechanism for CAG repeat containing mRNAs.

  6. Null alleles at the Huntington disease locus: implications for diagnostics and CAG repeat instability.

    Science.gov (United States)

    Williams, L C; Hegde, M R; Nagappan, R; Faull, R L; Giles, J; Winship, I; Snow, K; Love, D R

    2000-01-01

    PCR amplification of the CAG repeat in exon 1 of the IT15 gene is routinely undertaken to confirm a clinical diagnosis of Huntington disease (HD) and to provide predictive testing for at-risk relatives of affected individuals. Our studies have detected null alleles on the chromosome carrying the expanded repeat in three of 91 apparently unrelated HD families. Sequence analysis of these alleles has revealed the same mutation event, leading to the juxtaposition of uninterrupted CAG and CCG repeats. These data suggest that a mutation-prone region exists in the IT15 gene bounded by the CAG and CCG repeats and that caution should be exercised in designing primers that anneal to the region bounded by these repeats. Two of the HD families segregated null alleles with expanded uninterrupted CAG repeats at the lower end of the zone of reduced penetrance. The expanded repeats are meiotically unstable in these families, although this instability is within a small range of repeat lengths. The haplotypes of the disease-causing chromosomes in these two families differ, only one of which is similar to that reported previously as being specific for new HD mutations. Finally, no apparent mitotic instability of the uninterrupted CAG repeat was observed in the brain of one of the HD individuals.

  7. Androgen receptor gene CAG repeat polymorphism and ovarian cancer risk: A meta-analysis.

    Science.gov (United States)

    Deng, Yang; Wang, Jue; Wang, Ling; Du, Yan

    2017-02-28

    Ovarian cancer is one of the common gynecological malignancies worldwide. It is usually diagnosed at a later stage, thus missing the best opportunity for treatment. Despite the advancement of ovarian cancer treatment, the prognosis is still poor. Androgen receptor (AR) may play a role in ovarian carcinogenesis. Previous studies regarding the association between AR CAG repeat length and ovarian cancer risk reported inconsistent results. Therefore, we conducted a meta-analysis to evaluate the association between AR CAG repeat length and ovarian cancer risk following the MOOSE guidelines. PubMed, Web of Science, EBSCO and other databases were searched up to September 15(th) 2016. Case control studies with clear definition of CAG repeat length and detailed genotype information were included. Two authors independently reviewed and extracted data. Pooled analysis and subgroup analysis stratified by ethnicity were performed for different genetic models. Begg's funnel plot and Egger's test were performed for publication bias estimation. Overall, there was no association between the AR CAG repeat polymorphism and ovarian cancer risk. However, short CAG repeat polymorphism was associated with increased ovarian cancer risk in African Americans and Chinese under the dominant model, whereas a reverse association was observed in Caucasians and Italians under the other three models. Our study results should be interpreted with caution. Further well-designed epidemiological and functional studies are needed to elucidate the role of AR in ovarian carcinogenesis.

  8. Discovery, Characterization, and Functional Study of a Novel MEF2D CAG Repeat in Duck (Anas platyrhynchos).

    Science.gov (United States)

    Wang, Yushi; Wang, Jiwen; Liu, Hehe; Zhang, Rongping; Zhang, Tao; Gan, Xiang; Huang, Huilan; Chen, Da; Li, Liang

    2016-08-01

    Myocyte enhancer transcription factor 2D (MEF2D) is an important transcription factor for promoting the growth and development of muscle. CAG repeats have been found in the coding sequence (CDS) of avian MEF2D; however, their functions remain unknown and require further investigation. Here, we examined the characteristics and functional role of MEF2D CAG repeat in duck. The full-length CDS of duck MEF2D was cloned for the first time, and a novel CAG repeat was identified and located in exon 9. Sequence analysis indicated that the protein domains of duck MEF2D are highly conserved relative to other vertebrates, whereas MEF2D CAG repeats with variable repeat numbers are specific to avian species. Furthermore, sequencing has revealed polymorphisms in MEF2D CAG repeat at both DNA and mRNA levels. Four MEF2D CAG repeat genotypes and 10 MEF2D cDNA variants with different CAG repeat numbers were detected in two duck populations. A t-test showed that the expanded CAG repeat generated significantly longer transcription products (p analysis demonstrated positive correlations between the expansion of the CAG repeat and five muscle-related traits. By using protein structure prediction, we suggested that the polymorphisms of the CAG repeat affect protein structures within protein domains. Taken together, these findings reveal that duck MEF2D CAG repeat is a potential functional element with polymorphisms and may cause differences in MEF2D function between duck and other vertebrate species.

  9. Molecular cloning and expression of a novel human cDNA containing CAG repeats.

    Science.gov (United States)

    Takeuchi, T; Chen, B K; Qiu, Y; Sonobe, H; Ohtsuki, Y

    1997-12-19

    A novel human cDNA containing CAG repeats, designated B120, was cloned by PCR amplification. An approximately 300-bp 3' untranslated region in this cDNA was followed by a 3426-bp coding region containing the CAG repeats. A computer search failed to find any significant homology between this cDNA and previously reported genes. The number of CAG trinucleotide repeats appeared to vary from seven to 12 in analyses of genomic DNA from healthy volunteers. An approximately 8-kb band was detected in brain, skeletal muscle and thymus by Northern blot analysis. The deduced amino-acid sequence had a polyglutamine chain encoded by CAG repeats as well as glutamine- and tyrosine-rich repeats, which has also been reported for several RNA binding proteins. We immunized mice with recombinant gene product and established a monoclonal antibody to it. On Western immunoblotting, this antibody detected an approximately 120-kDa protein in human brain tissue. In addition, immunohistochemical staining showed that the cytoplasm of neural cells was stained with this antibody. These findings indicated that B120 is a novel cDNA with a CAG repeat length polymorphism and that its gene product is a cytoplasmic protein with a molecular mass of 120 kDa.

  10. CAG repeat expansion in Huntington disease determines age at onset in a fully dominant fashion

    Science.gov (United States)

    Lee, J.-M.; Ramos, E.M.; Lee, J.-H.; Gillis, T.; Mysore, J.S.; Hayden, M.R.; Warby, S.C.; Morrison, P.; Nance, M.; Ross, C.A.; Margolis, R.L.; Squitieri, F.; Orobello, S.; Di Donato, S.; Gomez-Tortosa, E.; Ayuso, C.; Suchowersky, O.; Trent, R.J.A.; McCusker, E.; Novelletto, A.; Frontali, M.; Jones, R.; Ashizawa, T.; Frank, S.; Saint-Hilaire, M.H.; Hersch, S.M.; Rosas, H.D.; Lucente, D.; Harrison, M.B.; Zanko, A.; Abramson, R.K.; Marder, K.; Sequeiros, J.; Paulsen, J.S.; Landwehrmeyer, G.B.; Myers, R.H.; MacDonald, M.E.; Durr, Alexandra; Rosenblatt, Adam; Frati, Luigi; Perlman, Susan; Conneally, Patrick M.; Klimek, Mary Lou; Diggin, Melissa; Hadzi, Tiffany; Duckett, Ayana; Ahmed, Anwar; Allen, Paul; Ames, David; Anderson, Christine; Anderson, Karla; Anderson, Karen; Andrews, Thomasin; Ashburner, John; Axelson, Eric; Aylward, Elizabeth; Barker, Roger A.; Barth, Katrin; Barton, Stacey; Baynes, Kathleen; Bea, Alexandra; Beall, Erik; Beg, Mirza Faisal; Beglinger, Leigh J.; Biglan, Kevin; Bjork, Kristine; Blanchard, Steve; Bockholt, Jeremy; Bommu, Sudharshan Reddy; Brossman, Bradley; Burrows, Maggie; Calhoun, Vince; Carlozzi, Noelle; Chesire, Amy; Chiu, Edmond; Chua, Phyllis; Connell, R.J.; Connor, Carmela; Corey-Bloom, Jody; Craufurd, David; Cross, Stephen; Cysique, Lucette; Santos, Rachelle Dar; Davis, Jennifer; Decolongon, Joji; DiPietro, Anna; Doucette, Nicholas; Downing, Nancy; Dudler, Ann; Dunn, Steve; Ecker, Daniel; Epping, Eric A.; Erickson, Diane; Erwin, Cheryl; Evans, Ken; Factor, Stewart A.; Farias, Sarah; Fatas, Marta; Fiedorowicz, Jess; Fullam, Ruth; Furtado, Sarah; Garde, Monica Bascunana; Gehl, Carissa; Geschwind, Michael D.; Goh, Anita; Gooblar, Jon; Goodman, Anna; Griffith, Jane; Groves, Mark; Guttman, Mark; Hamilton, Joanne; Harrington, Deborah; Harris, Greg; Heaton, Robert K.; Helmer, Karl; Henneberry, Machelle; Hershey, Tamara; Herwig, Kelly; Howard, Elizabeth; Hunter, Christine; Jankovic, Joseph; Johnson, Hans; Johnson, Arik; Jones, Kathy; Juhl, Andrew; Kim, Eun Young; Kimble, Mycah; King, Pamela; Klimek, Mary Lou; Klöppel, Stefan; Koenig, Katherine; Komiti, Angela; Kumar, Rajeev; Langbehn, Douglas; Leavitt, Blair; Leserman, Anne; Lim, Kelvin; Lipe, Hillary; Lowe, Mark; Magnotta, Vincent A.; Mallonee, William M.; Mans, Nicole; Marietta, Jacquie; Marshall, Frederick; Martin, Wayne; Mason, Sarah; Matheson, Kirsty; Matson, Wayne; Mazzoni, Pietro; McDowell, William; Miedzybrodzka, Zosia; Miller, Michael; Mills, James; Miracle, Dawn; Montross, Kelsey; Moore, David; Mori, Sasumu; Moser, David J.; Moskowitz, Carol; Newman, Emily; Nopoulos, Peg; Novak, Marianne; O'Rourke, Justin; Oakes, David; Ondo, William; Orth, Michael; Panegyres, Peter; Pease, Karen; Perlman, Susan; Perlmutter, Joel; Peterson, Asa; Phillips, Michael; Pierson, Ron; Potkin, Steve; Preston, Joy; Quaid, Kimberly; Radtke, Dawn; Rae, Daniela; Rao, Stephen; Raymond, Lynn; Reading, Sarah; Ready, Rebecca; Reece, Christine; Reilmann, Ralf; Reynolds, Norm; Richardson, Kylie; Rickards, Hugh; Ro, Eunyoe; Robinson, Robert; Rodnitzky, Robert; Rogers, Ben; Rosenblatt, Adam; Rosser, Elisabeth; Rosser, Anne; Price, Kathy; Price, Kathy; Ryan, Pat; Salmon, David; Samii, Ali; Schumacher, Jamy; Schumacher, Jessica; Sendon, Jose Luis Lópenz; Shear, Paula; Sheinberg, Alanna; Shpritz, Barnett; Siedlecki, Karen; Simpson, Sheila A.; Singer, Adam; Smith, Jim; Smith, Megan; Smith, Glenn; Snyder, Pete; Song, Allen; Sran, Satwinder; Stephan, Klaas; Stober, Janice; Sü?muth, Sigurd; Suter, Greg; Tabrizi, Sarah; Tempkin, Terry; Testa, Claudia; Thompson, Sean; Thomsen, Teri; Thumma, Kelli; Toga, Arthur; Trautmann, Sonja; Tremont, Geoff; Turner, Jessica; Uc, Ergun; Vaccarino, Anthony; van Duijn, Eric; Van Walsem, Marleen; Vik, Stacie; Vonsattel, Jean Paul; Vuletich, Elizabeth; Warner, Tom; Wasserman, Paula; Wassink, Thomas; Waterman, Elijah; Weaver, Kurt; Weir, David; Welsh, Claire; Werling-Witkoske, Chris; Wesson, Melissa; Westervelt, Holly; Weydt, Patrick; Wheelock, Vicki; Williams, Kent; Williams, Janet; Wodarski, Mary; Wojcieszek, Joanne; Wood, Jessica; Wood-Siverio, Cathy; Wu, Shuhua; Yastrubetskaya, Olga; de Yebenes, Justo Garcia; Zhao, Yong Qiang; Zimbelman, Janice; Zschiegner, Roland; Aaserud, Olaf; Abbruzzese, Giovanni; Andrews, Thomasin; Andrich, Jurgin; Antczak, Jakub; Arran, Natalie; Artiga, Maria J. Saiz; Bachoud-Lévi, Anne-Catherine; Banaszkiewicz, Krysztof; di Poggio, Monica Bandettini; Bandmann, Oliver; Barbera, Miguel A.; Barker, Roger A.; Barrero, Francisco; Barth, Katrin; Bas, Jordi; Beister, Antoine; Bentivoglio, Anna Rita; Bertini, Elisabetta; Biunno, Ida; Bjørgo, Kathrine; Bjørnevoll, Inga; Bohlen, Stefan; Bonelli, Raphael M.; Bos, Reineke; Bourne, Colin; Bradbury, Alyson; Brockie, Peter; Brown, Felicity; Bruno, Stefania; Bryl, Anna; Buck, Andrea; Burg, Sabrina; Burgunder, Jean-Marc; Burns, Peter; Burrows, Liz; Busquets, Nuria; Busse, Monica; Calopa, Matilde; Carruesco, Gemma T.; Casado, Ana Gonzalez; Catena, Judit López; Chu, Carol; Ciesielska, Anna; Clapton, Jackie; Clayton, Carole; Clenaghan, Catherine; Coelho, Miguel; Connemann, Julia; Craufurd, David; Crooks, Jenny; Cubillo, Patricia Trigo; Cubo, Esther; Curtis, Adrienne; De Michele, Giuseppe; De Nicola, A.; de Souza, Jenny; de Weert, A. Marit; de Yébenes, Justo Garcia; Dekker, M.; Descals, A. Martínez; Di Maio, Luigi; Di Pietro, Anna; Dipple, Heather; Dose, Matthias; Dumas, Eve M.; Dunnett, Stephen; Ecker, Daniel; Elifani, F.; Ellison-Rose, Lynda; Elorza, Marina D.; Eschenbach, Carolin; Evans, Carole; Fairtlough, Helen; Fannemel, Madelein; Fasano, Alfonso; Fenollar, Maria; Ferrandes, Giovanna; Ferreira, Jaoquim J.; Fillingham, Kay; Finisterra, Ana Maria; Fisher, K.; Fletcher, Amy; Foster, Jillian; Foustanos, Isabella; Frech, Fernando A.; Fullam, Robert; Fullham, Ruth; Gago, Miguel; García, RocioGarcía-Ramos; García, Socorro S.; Garrett, Carolina; Gellera, Cinzia; Gill, Paul; Ginestroni, Andrea; Golding, Charlotte; Goodman, Anna; Gørvell, Per; Grant, Janet; Griguoli, A.; Gross, Diana; Guedes, Leonor; BascuñanaGuerra, Monica; Guerra, Maria Rosalia; Guerrero, Rosa; Guia, Dolores B.; Guidubaldi, Arianna; Hallam, Caroline; Hamer, Stephanie; Hammer, Kathrin; Handley, Olivia J.; Harding, Alison; Hasholt, Lis; Hedge, Reikha; Heiberg, Arvid; Heinicke, Walburgis; Held, Christine; Hernanz, Laura Casas; Herranhof, Briggitte; Herrera, Carmen Durán; Hidding, Ute; Hiivola, Heli; Hill, Susan; Hjermind, Lena. E.; Hobson, Emma; Hoffmann, Rainer; Holl, Anna Hödl; Howard, Liz; Hunt, Sarah; Huson, Susan; Ialongo, Tamara; Idiago, Jesus Miguel R.; Illmann, Torsten; Jachinska, Katarzyna; Jacopini, Gioia; Jakobsen, Oda; Jamieson, Stuart; Jamrozik, Zygmunt; Janik, Piotr; Johns, Nicola; Jones, Lesley; Jones, Una; Jurgens, Caroline K.; Kaelin, Alain; Kalbarczyk, Anna; Kershaw, Ann; Khalil, Hanan; Kieni, Janina; Klimberg, Aneta; Koivisto, Susana P.; Koppers, Kerstin; Kosinski, Christoph Michael; Krawczyk, Malgorzata; Kremer, Berry; Krysa, Wioletta; Kwiecinski, Hubert; Lahiri, Nayana; Lambeck, Johann; Lange, Herwig; Laver, Fiona; Leenders, K.L.; Levey, Jamie; Leythaeuser, Gabriele; Lezius, Franziska; Llesoy, Joan Roig; Löhle, Matthias; López, Cristobal Diez-Aja; Lorenza, Fortuna; Loria, Giovanna; Magnet, Markus; Mandich, Paola; Marchese, Roberta; Marcinkowski, Jerzy; Mariotti, Caterina; Mariscal, Natividad; Markova, Ivana; Marquard, Ralf; Martikainen, Kirsti; Martínez, Isabel Haro; Martínez-Descals, Asuncion; Martino, T.; Mason, Sarah; McKenzie, Sue; Mechi, Claudia; Mendes, Tiago; Mestre, Tiago; Middleton, Julia; Milkereit, Eva; Miller, Joanne; Miller, Julie; Minster, Sara; Möller, Jens Carsten; Monza, Daniela; Morales, Blas; Moreau, Laura V.; Moreno, Jose L. López-Sendón; Münchau, Alexander; Murch, Ann; Nielsen, Jørgen E.; Niess, Anke; Nørremølle, Anne; Novak, Marianne; O'Donovan, Kristy; Orth, Michael; Otti, Daniela; Owen, Michael; Padieu, Helene; Paganini, Marco; Painold, Annamaria; Päivärinta, Markku; Partington-Jones, Lucy; Paterski, Laurent; Paterson, Nicole; Patino, Dawn; Patton, Michael; Peinemann, Alexander; Peppa, Nadia; Perea, Maria Fuensanta Noguera; Peterson, Maria; Piacentini, Silvia; Piano, Carla; Càrdenas, Regina Pons i; Prehn, Christian; Price, Kathleen; Probst, Daniela; Quarrell, Oliver; Quiroga, Purificacion Pin; Raab, Tina; Rakowicz, Maryla; Raman, Ashok; Raymond, Lucy; Reilmann, Ralf; Reinante, Gema; Reisinger, Karin; Retterstol, Lars; Ribaï, Pascale; Riballo, Antonio V.; Ribas, Guillermo G.; Richter, Sven; Rickards, Hugh; Rinaldi, Carlo; Rissling, Ida; Ritchie, Stuart; Rivera, Susana Vázquez; Robert, Misericordia Floriach; Roca, Elvira; Romano, Silvia; Romoli, Anna Maria; Roos, Raymond A.C.; Røren, Niini; Rose, Sarah; Rosser, Elisabeth; Rosser, Anne; Rossi, Fabiana; Rothery, Jean; Rudzinska, Monika; Ruíz, Pedro J. García; Ruíz, Belan Garzon; Russo, Cinzia Valeria; Ryglewicz, Danuta; Saft, Carston; Salvatore, Elena; Sánchez, Vicenta; Sando, Sigrid Botne; Šašinková, Pavla; Sass, Christian; Scheibl, Monika; Schiefer, Johannes; Schlangen, Christiane; Schmidt, Simone; Schöggl, Helmut; Schrenk, Caroline; Schüpbach, Michael; Schuierer, Michele; Sebastián, Ana Rojo; Selimbegovic-Turkovic, Amina; Sempolowicz, Justyna; Silva, Mark; Sitek, Emilia; Slawek, Jaroslaw; Snowden, Julie; Soleti, Francesco; Soliveri, Paola; Sollom, Andrea; Soltan, Witold; Sorbi, Sandro; Sorensen, Sven Asger; Spadaro, Maria; Städtler, Michael; Stamm, Christiane; Steiner, Tanja; Stokholm, Jette; Stokke, Bodil; Stopford, Cheryl; Storch, Alexander; Straßburger, Katrin; Stubbe, Lars; Sulek, Anna; Szczudlik, Andrzej; Tabrizi, Sarah; Taylor, Rachel; Terol, Santiago Duran-Sindreu; Thomas, Gareth; Thompson, Jennifer; Thomson, Aileen; Tidswell, Katherine; Torres, Maria M. Antequera; Toscano, Jean; Townhill, Jenny; Trautmann, Sonja; Tucci, Tecla; Tuuha, Katri; Uhrova, Tereza; Valadas, Anabela; van Hout, Monique S.E.; van Oostrom, J.C.H.; van Vugt, Jeroen P.P.; vanm, Walsem Marleen R.; Vandenberghe, Wim; Verellen-Dumoulin, Christine; Vergara, Mar Ruiz; Verstappen, C.C.P.; Verstraelen, Nichola; Viladrich, Celia Mareca; Villanueva, Clara; Wahlström, Jan; Warner, Thomas; Wehus, Raghild; Weindl, Adolf; Werner, Cornelius J.; Westmoreland, Leann; Weydt, Patrick; Wiedemann, Alexandra; Wild, Edward; Wild, Sue; Witjes-Ané, Marie-Noelle; Witkowski, Grzegorz; Wójcik, Magdalena; Wolz, Martin; Wolz, Annett; Wright, Jan; Yardumian, Pam; Yates, Shona; Yudina, Elizaveta; Zaremba, Jacek; Zaugg, Sabine W.; Zdzienicka, Elzbieta; Zielonka, Daniel; Zielonka, Euginiusz; Zinzi, Paola; Zittel, Simone; Zucker, Birgrit; Adams, John; Agarwal, Pinky; Antonijevic, Irina; Beck, Christopher; Chiu, Edmond; Churchyard, Andrew; Colcher, Amy; Corey-Bloom, Jody; Dorsey, Ray; Drazinic, Carolyn; Dubinsky, Richard; Duff, Kevin; Factor, Stewart; Foroud, Tatiana; Furtado, Sarah; Giuliano, Joe; Greenamyre, Timothy; Higgins, Don; Jankovic, Joseph; Jennings, Dana; Kang, Un Jung; Kostyk, Sandra; Kumar, Rajeev; Leavitt, Blair; LeDoux, Mark; Mallonee, William; Marshall, Frederick; Mohlo, Eric; Morgan, John; Oakes, David; Panegyres, Peter; Panisset, Michel; Perlman, Susan; Perlmutter, Joel; Quaid, Kimberly; Raymond, Lynn; Revilla, Fredy; Robertson, Suzanne; Robottom, Bradley; Sanchez-Ramos, Juan; Scott, Burton; Shannon, Kathleen; Shoulson, Ira; Singer, Carlos; Tabbal, Samer; Testa, Claudia; van, Kammen Dan; Vetter, Louise; Walker, Francis; Warner, John; Weiner, illiam; Wheelock, Vicki; Yastrubetskaya, Olga; Barton, Stacey; Broyles, Janice; Clouse, Ronda; Coleman, Allison; Davis, Robert; Decolongon, Joji; DeLaRosa, Jeanene; Deuel, Lisa; Dietrich, Susan; Dubinsky, Hilary; Eaton, Ken; Erickson, Diane; Fitzpatrick, Mary Jane; Frucht, Steven; Gartner, Maureen; Goldstein, Jody; Griffith, Jane; Hickey, Charlyne; Hunt, Victoria; Jaglin, Jeana; Klimek, Mary Lou; Lindsay, Pat; Louis, Elan; Loy, Clemet; Lucarelli, Nancy; Malarick, Keith; Martin, Amanda; McInnis, Robert; Moskowitz, Carol; Muratori, Lisa; Nucifora, Frederick; O'Neill, Christine; Palao, Alicia; Peavy, Guerry; Quesada, Monica; Schmidt, Amy; Segro, Vicki; Sperin, Elaine; Suter, Greg; Tanev, Kalo; Tempkin, Teresa; Thiede, Curtis; Wasserman, Paula; Welsh, Claire; Wesson, Melissa; Zauber, Elizabeth

    2012-01-01

    Objective: Age at onset of diagnostic motor manifestations in Huntington disease (HD) is strongly correlated with an expanded CAG trinucleotide repeat. The length of the normal CAG repeat allele has been reported also to influence age at onset, in interaction with the expanded allele. Due to profound implications for disease mechanism and modification, we tested whether the normal allele, interaction between the expanded and normal alleles, or presence of a second expanded allele affects age at onset of HD motor signs. Methods: We modeled natural log-transformed age at onset as a function of CAG repeat lengths of expanded and normal alleles and their interaction by linear regression. Results: An apparently significant effect of interaction on age at motor onset among 4,068 subjects was dependent on a single outlier data point. A rigorous statistical analysis with a well-behaved dataset that conformed to the fundamental assumptions of linear regression (e.g., constant variance and normally distributed error) revealed significance only for the expanded CAG repeat, with no effect of the normal CAG repeat. Ten subjects with 2 expanded alleles showed an age at motor onset consistent with the length of the larger expanded allele. Conclusions: Normal allele CAG length, interaction between expanded and normal alleles, and presence of a second expanded allele do not influence age at onset of motor manifestations, indicating that the rate of HD pathogenesis leading to motor diagnosis is determined by a completely dominant action of the longest expanded allele and as yet unidentified genetic or environmental factors. Neurology® 2012;78:690–695 PMID:22323755

  11. CAG repeat expansions in bipolar and unipolar disorders

    Energy Technology Data Exchange (ETDEWEB)

    Oruc, L.; Verheyen, G.R.; Raeymaekers, P.; Van Broeckhoven, C. [Univ. of Antwerp (Belgium)] [and others

    1997-03-01

    Family, twin, and adoption studies consistently have indicated that the familial aggregation of bipolar (BP) disorder and unipolar recurrent major depression (UPR) is accounted for largely by genetic factors. However, the mode of inheritance is complex. One of the possible explanations could be that a gene with variable penetrance and variable expression is involved. Recently there have been reports on a new class of genetic diseases caused by an abnormal trinucleotide-repeat expansion (TRE). In a number of genetic disorders, these dynamic mutations were proved to be the biological basis for the clinically observed phenomenon of anticipation. DNA consisting of repeated triplets of nucleotides becomes unstable and increases in size over generations within families, giving rise to an increased severity and/or an earlier onset of the disorder. It has been recognized for a long time that anticipation occurs in multiplex families transmitting mental illness. More recent studies also suggest that both BP disorder and UPR show features that are compatible with anticipation. Although the findings of anticipation in BP disorders and in UPR must be interpreted with caution because of the possible presence of numerous ascertainment biases, they support the hypothesis that pathological TREs are implicated in the transmission of these disorders. TRE combined with variable penetrance of expression could explain the complex transmission pattern observed in BP disorder. In view of this, the recent reports of an association between CAG-repeat length and BP disorder in a Belgian, Swedish, and British population are promising. 14 refs., 1 fig., 1 tab.

  12. Genetic Contributors to Intergenerational CAG Repeat Instability in Huntington’s Disease Knock-In Mice

    Science.gov (United States)

    Neto, João Luís; Lee, Jong-Min; Afridi, Ali; Gillis, Tammy; Guide, Jolene R.; Dempsey, Stephani; Lager, Brenda; Alonso, Isabel; Wheeler, Vanessa C.; Pinto, Ricardo Mouro

    2017-01-01

    Huntington’s disease (HD) is a neurodegenerative disorder caused by the expansion of a CAG trinucleotide repeat in exon 1 of the HTT gene. Longer repeat sizes are associated with increased disease penetrance and earlier ages of onset. Intergenerationally unstable transmissions are common in HD families, partly underlying the genetic anticipation seen in this disorder. HD CAG knock-in mouse models also exhibit a propensity for intergenerational repeat size changes. In this work, we examine intergenerational instability of the CAG repeat in over 20,000 transmissions in the largest HD knock-in mouse model breeding datasets reported to date. We confirmed previous observations that parental sex drives the relative ratio of expansions and contractions. The large datasets further allowed us to distinguish effects of paternal CAG repeat length on the magnitude and frequency of expansions and contractions, as well as the identification of large repeat size jumps in the knock-in models. Distinct degrees of intergenerational instability were observed between knock-in mice of six background strains, indicating the occurrence of trans-acting genetic modifiers. We also found that lines harboring a neomycin resistance cassette upstream of Htt showed reduced expansion frequency, indicative of a contributing role for sequences in cis, with the expanded repeat as modifiers of intergenerational instability. These results provide a basis for further understanding of the mechanisms underlying intergenerational repeat instability. PMID:27913616

  13. Androgen receptor gene CAG and GGN repeat polymorphisms in Chilean men with primary severe spermatogenic failure.

    Science.gov (United States)

    Castro-Nallar, Eduardo; Bacallao, Ketty; Parada-Bustamante, Alexis; Lardone, María C; López, Patricia V; Madariaga, Marcia; Valdevenito, Raúl; Piottante, Antonio; Ebensperger, Mauricio; Castro, Andrea

    2010-01-01

    There is ample documentation supporting the fact that androgens are required for normal spermatogenesis. A minority of infertile men have abnormal testosterone blood levels or mild androgen receptor mutations. We investigated the androgen receptor CAG and GGN repeat lengths in Chilean men with spermatogenic impairment. We studied 117 secretory azoospermic/oligozoospermic men (93 idiopathic and 24 excryptorchidic), without Y-chromosome microdeletions, and 121 controls with normal spermatogenesis (42 obstructive and 79 normozoospermic men). Peripheral blood was drawn to obtain genomic DNA for polymerase chain reaction and automated sequencing of CAG and GGN repeats. Testicular characterization included hormonal studies, physical evaluation, and seminal and biopsy analysis. The CAG and GGN polymorphism distributions were similar among idiopathic men, excryptorchidic men, and controls and among the different types of spermatogenic impairment. However, the proportion of the CAG 21 allele was significantly increased in idiopathic cases compared to controls (P = .012 by Bonferroni test, odds ratio = 2.99, 95% confidence interval, 1.27-7.0) and the CAG 32 allele only was observed in excryptorchidic patients (P CAG 21 allele (P = .024, χ(2) test). On the other hand, in idiopathic cases and controls the most common GGN allele was 23, followed by 24, but an inverse relation was found among excryptorchidic cases. The joint distribution of CAG and GGN in control, idiopathic, and excryptorchidic groups did not show an association between the 2 allele repeat polymorphisms (P > 0.05, χ(2) test). Our results suggest that the CAG 21 allele seems to increase the risk of idiopathic Sertoli cell-only syndrome. Moreover, the GGN 24 allele could be contributing to deranged androgen receptor function, associated with cryptorchidism and spermatogenic failure.

  14. Somatic expansion of the Huntington's disease CAG repeat in the brain is associated with an earlier age of disease onset.

    Science.gov (United States)

    Swami, Meera; Hendricks, Audrey E; Gillis, Tammy; Massood, Tiffany; Mysore, Jayalakshmi; Myers, Richard H; Wheeler, Vanessa C

    2009-08-15

    The age of onset of Huntington's disease (HD) is determined primarily by the length of the HD CAG repeat mutation, but is also influenced by other modifying factors. Delineating these modifiers is a critical step towards developing validated therapeutic targets in HD patients. The HD CAG repeat is somatically unstable, undergoing progressive length increases over time, particularly in brain regions that are the targets of neurodegeneration. Here, we have explored the hypothesis that somatic instability of the HD CAG repeat is itself a modifier of disease. Using small-pool PCR, we quantified somatic instability in the cortex region of the brain from a cohort of HD individuals exhibiting phenotypic extremes of young and old disease onset as predicted by the length of their constitutive HD CAG repeat lengths. After accounting for constitutive repeat length, somatic instability was found to be a significant predictor of onset age, with larger repeat length gains associated with earlier disease onset. These data are consistent with the hypothesis that somatic HD CAG repeat length expansions in target tissues contribute to the HD pathogenic process, and support pursuing factors that modify somatic instability as viable therapeutic targets.

  15. Comparative semi-automated analysis of (CAG) repeats in the Huntington disease gene: use of internal standards.

    Science.gov (United States)

    Williams, L C; Hegde, M R; Herrera, G; Stapleton, P M; Love, D R

    1999-08-01

    Huntington disease (HD) belongs to the group of neurodegenerative disorders characterized by unstable expanded trinucleotide repeats. In the case of HD, the expansion of a CAG repeat occurs in the IT15 gene. The detection of the expanded CAG repeats has usually involved the electrophoretic separation of polymerase chain reaction (PCR) amplification products using conventional agarose and acrylamide gel electrophoresis. We have undertaken the comparative analysis of sizing CAG repeats of the IT15 gene using radioactive and fluorescent PCR amplification, and the subsequent separation of these products by slab gel and capillary electrophoresis. The assays have been performed on both cloned and sequenced CAG repeats, as well as genomic DNA from HD patients with a wide range of repeat lengths. The mobility of the CAG repeat amplification products of the IT15 gene is greater using capillary electrophoresis compared to slab gel electrophoresis. The analysis of 40 DNA samples from HD patients indicates that the mobility difference increases with the length of the repeat. However, we have devised an allele ladder for sizing the CAG repeats. This ladder provides a mandatory internal calibration system for diagnostic purposes and enables the confident use of either capillary or slab gel electrophoresis for sizing HD alleles.

  16. Early onset and novel features in a spinal and bulbar muscular atrophy patient with a 68 CAG repeat.

    Science.gov (United States)

    Grunseich, Christopher; Kats, Ilona R; Bott, Laura C; Rinaldi, Carlo; Kokkinis, Angela; Fox, Derrick; Chen, Ke-Lian; Schindler, Alice B; Mankodi, Ami K; Shrader, Joseph A; Schwartz, Daniel P; Lehky, Tanya J; Liu, Chia-Ying; Fischbeck, Kenneth H

    2014-11-01

    Spinal and bulbar muscular atrophy (SBMA) is an X-linked neuromuscular disease caused by a trinucleotide (CAG) repeat expansion in the androgen receptor gene. Patients with SBMA have weakness, atrophy, and fasciculations in the bulbar and extremity muscles. Individuals with CAG repeat lengths greater than 62 have not previously been reported. We evaluated a 29year old SBMA patient with 68 CAGs who had unusually early onset and findings not seen in others with the disease. Analysis of the androgen receptor gene confirmed the repeat length of 68 CAGs in both peripheral blood and fibroblasts. Evaluation of muscle and sensory function showed deficits typical of SBMA, and in addition the patient had manifestations of autonomic dysfunction and abnormal sexual development. These findings extend the known phenotype associated with SBMA and shed new insight into the effects of the mutated androgen receptor.

  17. Increased risk of breast cancer in women bearing a combination of large CAG and GGN repeats in the exon 1 of the androgen receptor gene.

    Science.gov (United States)

    González, Ana; Javier Dorta, F; Rodriguez, Germán; Brito, Buenaventura; Rodríguez, M A Del Cristo; Cabrera, Antonio; Díaz-Chico, Juan C; Reyes, Ricardo; Aguirre-Jaime, Armando; Nicolás Díaz-Chico, B

    2007-11-01

    The exon 1 of the human androgen receptor gene (AR) contains both CAG (polyglutamine) and GGN (polyglycine) repeat length polymorphisms. Large CAG repeats have been related to an increased risk of breast cancer (BC), whereas the influence of the GGN repeats is still unclear. Here, we have studied how the length of CAG and GGN repeats is associated with the risk of BC in a population from Tenerife (Canary Islands, Spain). The study was carried out on 257 woman diagnosed with BC and 393 controls, nesting in the 'CDC of the Canary Islands' cohort study. The AR CAG and GGN genotyping was performed by means of PCR amplification with specific fluorescently labelled primers followed by a capillary electrophoresis. The allelic distribution of CAG and GGN polymorphisms was similar in cases and controls. The mean of short and long CAG and GGN alleles did not show differences between cases and controls and the same was true when the average length of both CAG alleles (CAG(n)) and GGN alleles (GGN(n)) was considered. However, when CAG(n) and GGN(n) were categorised using 22 and 24 repeats as the cut-off point, respectively, significant differences between cases and controls were observed. The CAG(n)>22 repeats were more frequent in cases than in controls, being associated with an increased risk of BC (OR=1.49; CI(95%)=1.06-2.09; p=0.021). No significant differences were found for categorised GGN(n). For CAG(n)/GGN(n) combinations, the highest BC risk was found to be associated with the CAG(n)>22/GGN(n)24 combination (OR=2.47; CI(95%)=1.37-4.46; p=0.003). In conclusion, our results indicate that longer CAG(n)/GGN(n) combinations increase the risk of BC and suggest that CAG and GGN AR polymorphisms should be considered in order to assess the BC risk.

  18. Long tract of untranslated CAG repeats is deleterious in transgenic mice.

    Directory of Open Access Journals (Sweden)

    Ren-Jun Hsu

    Full Text Available The most frequent trinucleotide repeat found in human disorders is the CAG sequence. Expansion of CAG repeats is mostly found in coding regions and is thought to cause diseases through a protein mechanism. Recently, expanded CAG repeats were shown to induce toxicity at the RNA level in Drosophila and C. elegans. These findings raise the possibility that CAG repeats may trigger RNA-mediated pathogenesis in mammals. Here, we demonstrate that transgenic mice expressing EGFP transcripts with long CAG repeats in the 3' untranslated region develop pathogenic features. Expression of the transgene was directed to the muscle in order to compare the resulting phenotype to that caused by the CUG expansion, as occurs in myotonic dystrophy. Transgenic mice expressing 200, but not those expressing 0 or 23 CAG repeats, showed alterations in muscle morphology, histochemistry and electrophysiology, as well as abnormal behavioral phenotypes. Expression of the expanded CAG repeats in testes resulted in reduced fertility due to defective sperm motility. The production of EGFP protein was significantly reduced by the 200 CAG repeats, and no polyglutamine-containing product was detected, which argues against a protein mechanism. Moreover, nuclear RNA foci were detected for the long CAG repeats. These data support the notion that expanded CAG repeat RNA can cause deleterious effects in mammals. They also suggest the possible involvement of an RNA mechanism in human diseases with long CAG repeats.

  19. Repeat Associated Non-AUG Translation (RAN Translation Dependent on Sequence Downstream of the ATXN2 CAG Repeat.

    Directory of Open Access Journals (Sweden)

    Daniel R Scoles

    Full Text Available Spinocerebellar ataxia type 2 (SCA2 is a progressive autosomal dominant disorder caused by the expansion of a CAG tract in the ATXN2 gene. The SCA2 disease phenotype is characterized by cerebellar atrophy, gait ataxia, and slow saccades. ATXN2 mutation causes gains of toxic and normal functions of the ATXN2 gene product, ataxin-2, and abnormally slow Purkinje cell firing frequency. Previously we investigated features of ATXN2 controlling expression and noted expression differences for ATXN2 constructs with varying CAG lengths, suggestive of repeat associated non-AUG translation (RAN translation. To determine whether RAN translation occurs for ATXN2 we assembled various ATXN2 constructs with ATXN2 tagged by luciferase, HA or FLAG tags, driven by the CMV promoter or the ATXN2 promoter. Luciferase expression from ATXN2-luciferase constructs lacking the ATXN2 start codon was weak vs AUG translation, regardless of promoter type, and did not increase with longer CAG repeat lengths. RAN translation was detected on western blots by the anti-polyglutamine antibody 1C2 for constructs driven by the CMV promoter but not the ATXN2 promoter, and was weaker than AUG translation. Strong RAN translation was also observed when driving the ATXN2 sequence with the CMV promoter with ATXN2 sequence downstream of the CAG repeat truncated to 18 bp in the polyglutamine frame but not in the polyserine or polyalanine frames. Our data demonstrate that ATXN2 RAN translation is weak compared to AUG translation and is dependent on ATXN2 sequences flanking the CAG repeat.

  20. 肯尼迪病临床特征与CAG重复序列数目关系分析%The clinical features of Kennedy disease and the correlation between clinical features and length of CAG re-peats

    Institute of Scientific and Technical Information of China (English)

    何炳接; 何若洁; 石磊; 叶城辉; 戴佳颖; 梁银杏; 卢锡林; 姚晓黎

    2015-01-01

    had family history. Clinical features included medulla oblongata and spinal muscular atrophy and weakness, limbs tremor, perioral muscles twitch and endocrine function and metabolic disorders in some cases. Creatine kinase, triglyceride, low density lipoprotein, follicle estrogen and prolactin were significantly in⁃creased compared to healthy adults (P:0.000,0.018,0.000,0.000,0.003). The number of CAG repeat was negatively correlated with the onset age (r=-0.549, P=0.001) but not associated with the illness severity (ALS rating scale) (r=0.001, P=0.998). ALS score was negatively correlated with course of disease(r=-0.540, P=0.001).Conclusions Chinese KD pa⁃ tients share similar clinical phenotypes with those of other races but exhibit slightly different clinical characteristics. The length of the CAG repeat influences age at onset but not the severity of disease. Severity of disease is related to the course of disease.

  1. The CAG repeat polymorphism in the androgen receptor gene (AR) and its relationship to head and neck cancer.

    Science.gov (United States)

    dos Santos, M L; Sibov, T T; Nishimoto, I N; Kowalski, L P; Miracca, E C; Nagai, M A

    2004-02-01

    Sex hormones may play an important role in the tumorigenic process of the head and neck. The aim of our work was to investigate whether the androgen receptor (AR) CAG repeat polymorphism is associated with an increased relative risk for head and neck cancer. Genomic DNA from 103 male patients with head and neck carcinomas and 100 male controls were analyzed for the AR CAG polymorphism by PCR amplification and direct sequencing or denaturing polyacrilamide gel electrophoresis. Logistic regression analysis showed a significant association between CAG repeat length and risk of head and neck cancer in individuals with more than 20 CAG repeats [OR=2.54 (95% CI, 1.3-4.8)]. For the group of individuals with oral and laryngeal cancer the estimated relative risk was increased to 2.79 (95% CI, 1.2-6.3) and 3.06 (95% CI, 1.0-9.6), respectively, in men with CAG repeat length >20. These results suggest, for the first time, that shorter AR CAG repeat alleles have a protective effect for head and neck cancer development.

  2. Polymorphisms in the CAG repeat--a source of error in Huntington disease DNA testing.

    Science.gov (United States)

    Yu, S; Fimmel, A; Fung, D; Trent, R J

    2000-12-01

    Five of 400 patients (1.3%), referred for Huntington disease DNA testing, demonstrated a single allele on CAG alone, but two alleles when the CAG + CCG repeats were measured. The PCR assay failed to detect one allele in the CAG alone assay because of single-base silent polymorphisms in the penultimate or the last CAG repeat. The region around and within the CAG repeat sequence in the Huntington disease gene is a hot-spot for DNA polymorphisms, which can occur in up to 1% of subjects tested for Huntington disease. These polymorphisms may interfere with amplification by PCR, and so have the potential to produce a diagnostic error.

  3. A general method for the detection of large CAG repeat expansions by fluorescent PCR

    OpenAIRE

    Warner, J P; Barron, L H; Goudie, D; Kelly, K; Dow, D.; FitzPatrick, D.R.; Brock, D J

    1996-01-01

    The expansion of a tandemly repeated trinucleotide sequence, CAG, is the mutational mechanism for several human genetic diseases. We present a generally applicable PCR amplification method using a fluorescently labelled locus specific primer flanking the CAG repeat together with paired primers amplifying from multiple priming sites within the CAG repeat. Triplet repeat primed PCR (TP PCR) gives a characteristic ladder on the fluorescence trace enabling the rapid identification of large pathog...

  4. CAG repeat polymorphisms in the androgen receptor and breast cancer risk in women: a meta-analysis of 17 studies.

    Science.gov (United States)

    Mao, Qixing; Qiu, Mantang; Dong, Gaochao; Xia, Wenjie; Zhang, Shuai; Xu, Youtao; Wang, Jie; Rong, Yin; Xu, Lin; Jiang, Feng

    2015-01-01

    The association between polymorphic CAG repeats in the androgen receptor gene in women and breast cancer susceptibility has been studied extensively. However, the conclusions regarding this relationship remain conflicting. The purpose of this meta-analysis was to identify whether androgen receptor CAG repeat lengths were related to breast cancer susceptibility. The MEDLINE, PubMed, and EMBASE databases were searched through to December 2014 to identify eligible studies. Data and study quality were rigorously assessed by two investigators according to the Newcastle-Ottawa Quality Assessment Scale. The publication bias was assessed by the Begg's test. Seventeen eligible studies were included in this meta-analysis. The overall analysis suggested no association between CAG polymorphisms and breast cancer risk (odds ratio [OR] 1.031, 95% confidence interval [CI] 0.855-1.245). However, in the subgroup analysis, we observed that long CAG repeats significantly increased the risk of breast cancer in the Caucasian population (OR 1.447, 95% CI 1.089-1.992). Additionally, the risk was significantly increased in Caucasian women carrying two alleles with CAG repeats ≥22 units compared with those with two shorter alleles (OR 1.315, 95% CI 1.014-1.707). These findings suggest that long CAG repeats increase the risk of breast cancer in Caucasian women. However, larger scale case-control studies are needed to validate our results.

  5. Predictive value of GGN and CAG repeat polymorphisms of androgen receptors in testicular cancer: a meta-analysis.

    Science.gov (United States)

    Jiang, Weijun; Zhang, Jing; Zhou, Qing; Liu, Shuaimei; Ni, Mengxia; Zhu, Peiran; Wu, Qiuyue; Li, Weiwei; Zhang, Mingchao; Xia, Xinyi

    2016-03-22

    The risk of testicular cancer (TC) is markedly increased in subjects with androgen insensitivity, and previous studies have proposed that GGN and CAG repeats in androgen receptors (AR) could be related to the risk of TC. To evaluate the association between the length of GGN and CAG repeats in AR and TC, a meta-analysis involving 3255 TC cases and 2804 controls was performed. The results suggested that long GGN repeats are associated with an increased risk of TC compared with those analysis revealed that this association occurred in studies with case sizes > 200, and in the mid-latitude, and seminoma subgroups. The subgroup analysis based on populations, high-latitude, and seminomas/non-seminomas suggested that AR CAG repeat polymorphisms with > 25 and 25 repeats might confer a protective effect to the patients with TC (in the high-latitude subgroup analysis, for > 25 vs. 21-25: OR = 0.54, 95% CI = 0.41-0.70). In contrast, an increased risk of TC was observed for AR CAG repeat polymorphisms with > 25 and 25 repeats in the mid-latitude subgroup (for > 25 vs. 21-25: OR = 1.65, 95% CI = 1.09-2.50). In addition, no associations between the remaining subgroups and male infertility were observed. In short, this meta-analysis suggested that AR GGN and CAG repeat polymorphisms may be involved in the etiology of TC.

  6. A new model for prediction of the age of onset and penetrance for Huntington's disease based on CAG length.

    Science.gov (United States)

    Langbehn, D R; Brinkman, R R; Falush, D; Paulsen, J S; Hayden, M R

    2004-04-01

    Huntington's disease (HD) is a neurodegenerative disorder caused by an unstable CAG repeat. For patients at risk, participating in predictive testing and learning of having CAG expansion, a major unanswered question shifts from "Will I get HD?" to "When will it manifest?" Using the largest cohort of HD patients analyzed to date (2913 individuals from 40 centers worldwide), we developed a parametric survival model based on CAG repeat length to predict the probability of neurological disease onset (based on motor neurological symptoms rather than psychiatric onset) at different ages for individual patients. We provide estimated probabilities of onset associated with CAG repeats between 36 and 56 for individuals of any age with narrow confidence intervals. For example, our model predicts a 91% chance that a 40-year-old individual with 42 repeats will have onset by the age of 65, with a 95% confidence interval from 90 to 93%. This model also defines the variability in HD onset that is not attributable to CAG length and provides information concerning CAG-related penetrance rates.

  7. CAG repeat polymorphism in androgen receptor gene is not directly associated with polycystic ovary syndrome but influences serum testosterone levels.

    Science.gov (United States)

    Skrgatic, L; Baldani, D Pavicic; Cerne, J Z; Ferk, P; Gersak, K

    2012-02-01

    Hyperandrogenemia has been the most consistent feature of polycystic ovary syndrome (PCOS). Androgens exert their effects through androgen receptors (ARs). The expansion of the codon CAG trinucleotide repeat polymorphism in exon 1 of the AR gene represents a type of genetic alteration associated with changes in the AR gene function. The purpose of this study was to establish a possible association of the AR gene CAG repeat length polymorphism with PCOS, and its influence on clinical and biochemical androgen traits. Two hundred and fourteen Croatian women with PCOS and 209 healthy control women of reproductive age were enrolled. Phenotypic hyperandrogenism, BMI and waist to hip ratio were recorded. Hormonal profiles, fasting insulin and glucose levels were measured on cycle days 3-5. Genotyping of the CAG repeat polymorphism in the AR gene was performed. We found no significant difference in the mean CAG repeat number between the PCOS patients and controls (22.1±3.4 vs. 21.9±3.2, P=0.286). There was a positive correlation between the CAG repeat length and total testosterone (TT) in the PCOS group (R=0.225, P=0.015). A multiple linear regression model using mean CAG repeat length, BMI, age and HOMA-IR as predictors explained 8.5% (adjusted R²) of the variability in serum TT levels. In this model the CAG repeat polymorphism was found to be a significant predictor of serum TT levels in PCOS patients (P=0.015). The logistic regression analysis revealed that the CAG repeat length is not a significant predictor of hirsutism and acne status (P=0.921 and P=0.437, respectively). The model was adjusted for serum TT, free testosterone, androstendione and DHEAS levels as independent variables, which were also not found to be significant predictors of hirsutism (P=0.687, P=0.194, P=0.675 and P=0.938, respectively) or acne status (P=0.594, P=0.095, P=0.290 and P=0.151, respectively). In conclusion, the AR CAG repeat polymorphism is not a major determinant of PCOS in the

  8. Mental rotation in intellectually gifted boys is affected by the androgen receptor CAG repeat polymorphism.

    Science.gov (United States)

    Durdiaková, Jaroslava; Lakatošová, Silvia; Kubranská, Aneta; Laznibatová, Jolana; Ficek, Andrej; Ostatníková, Daniela; Celec, Peter

    2013-08-01

    Testosterone was shown to organize brain and modulate cognitive functions. It is currently unknown whether mental rotation is also associated with prenatal testosterone exposure and testosterone-related genetic polymorphisms. The aim of our study was to analyze associations between mental rotation performance, the actual testosterone levels, the prenatal testosterone level (expressed as 2D:4D ratio) and the androgen receptor CAG repeat polymorphism in intellectually gifted boys. One hundred forty-seven boys aged 10-18 years with IQ>130 were enrolled. Saliva samples were collected and used for ELISA of actual levels of salivary testosterone. The 2D:4D finger length ratio as an indicator of prenatal testosterone was measured on both hands and averaged. Amthauer mental rotation test was used for the assessment of this spatial ability. The CAG repeat polymorphism in the androgen receptor gene was analyzed using PCR and capillary electrophoresis. Linear regression revealed that 2D:4D finger length ratio and the number of CAG repeats in the androgen receptor gene were associated with mental rotation. Actual levels of testosterone did not correlate significantly with mental rotation. Multivariate analysis of covariance revealed that after adjustment of age as a confounding variable, only the effect of the genetic polymorphism was significant. The results are in line with our previous genetic analysis of intellectually gifted boys showing the importance of CAG repeat polymorphism in the androgen receptor gene. Details of the interactions between androgen signaling, testosterone levels and its metabolism especially during the prenatal development of brain function remain to be elucidated.

  9. A general method for the detection of large CAG repeat expansions by fluorescent PCR.

    Science.gov (United States)

    Warner, J P; Barron, L H; Goudie, D; Kelly, K; Dow, D; Fitzpatrick, D R; Brock, D J

    1996-12-01

    The expansion of a tandemly repeated trinucleotide sequence, CAG, is the mutational mechanism for several human genetic diseases. We present a generally applicable PCR amplification method using a fluorescently labelled locus specific primer flanking the CAG repeat together with paired primers amplifying from multiple priming sites within the CAG repeat. Triplet repeat primed PCR (TP PCR) gives a characteristic ladder on the fluorescence trace enabling the rapid identification of large pathogenetic CAG repeats that cannot be amplified using flanking primers. We used our method to test a cohort of 183 people from myotonic dystrophy families including unaffected subjects and spouses. Eighty five clinically affected subjects with expanded alleles on Southern blot analysis were all correctly identified by TP PCR. This method is applicable for any human diseases involving CAG repeat expansions.

  10. Noninvasive prenatal diagnosis of Huntington disease: detection of the paternally inherited expanded CAG repeat in maternal plasma

    NARCIS (Netherlands)

    Oever, J.M. van den; Bijlsma, E.K.; Feenstra, I.; Muntjewerff, N.; Mathijssen, I.B.; Bakker, E. de; Belzen, M.J. van; Boon, E.M.

    2015-01-01

    OBJECTIVE: With a shift towards noninvasive testing, we have explored and validated the use of noninvasive prenatal diagnosis (NIPD) for Huntington disease (HD). METHODS: Fifteen couples have been included, assessing a total of n = 20 pregnancies. Fetal paternally inherited CAG repeat length was det

  11. Length of CAG repeat in exon 1 of the androgen receptor gene is associated with the development of acne%雄激素受体基因第一外显子CAG重复序列长度多态性与痤疮的相关性

    Institute of Scientific and Technical Information of China (English)

    庞莹; 姜弈; 魏华臣; 陈洪铎; 何春涤; 刘勇; 朱红; 魏彬; 王凯波; 赵宁; 王雅坤; 肖汀

    2008-01-01

    目的 探讨人雄激素受体基因第一外显子CAG重复序列长度多态性与痤疮发生之间的关系.方法 研究对象为中国东北地区238例痤疮患者和207例健康对照,抽取外周血后分离纯化出基因组DNA,采用微卫星扫描(STRs)方法分析CAG重复序列的多态性.结果 男性病例组和对照组的CAG重复均数分别为22.70±3.09和23.48±2.83,两组之间差异有统计学意义(P=0.046);将对照组中CAG重复次数的中位数23作为分割点分组比较,长/短CAG片段在男性病例和对照中的分布差异有统计学意义,携带有CAG短片段的男性较携带CAG长片段的男性患痤疮的风险性明显增加(OR值2.07;95%可信限为1.21~3.54).女性病例组和对照组的CAG重复均数分别为23.41±2.87和23.85±0.21,两组之间差异无统计学意义(P=0.115);按中位数分组比较长/短CAG片段在女性病例和对照中的分布差异有统计学意义,携带有CAG短片段的女性患痤疮的风险性明显增加(P=0.013,OR值2.05;95%可信限为1.18~3.56).结论 雄激素受体基因第一外显子CAG的重复次数与中国东北地区痤疮的发生有关,CAG重复次数少的男性个体患痤疮的风险性增加,雄激素受体基因第一外显子CAG的重复次数可作为痤疮的遗传易感标志之一.%Objective To investigate the relationship of CAG repeat length polymorphism in the androgen receptor(AR)gene to the development of acne.Methods A total of 238 patients with ache vulgaris and 207 healthy human controls in Northeast China were included in this study.Genomic DNA was isolated and purified from the blood of these subjects.The CAG repeat lengths in the AR gene were analyzed by somatic microsatellites (STRs).Results A significant difference was found in the CAG repeat number between the male acne Patients(22.70±3.09)and male controls(23.48±2.83,P=0.046),but not between the female cases and controls(23.41±2.87 versus 23.85±0.21.P=0.12).In order to assess the

  12. Spinal and bulbar muscular atrophy (SBMA): somatic stability of an expanded CAG repeat in fetal tissues.

    Science.gov (United States)

    Jedele, K B; Wahl, D; Chahrokh-Zadeh, S; Wirtz, A; Murken, J; Holinski-Feder, E

    1998-08-01

    Spinal and bulbar muscular atrophy (SBMA) is a rare X-linked motor neuron degenerative disease caused by an expanded trinucleotide repeat. Unlike most other trinucleotide repeat diseases, SBMA shows limited meiotic instability, and evidence thus far indicates absence of somatic instability in adults. Data regarding the presence of fetal tissue somatic mosaicism is unavailable. We present a family in which a woman whose father had SBMA requested prenatal testing. After informed consent. molecular genetic evaluation showed the male fetus to carry the SBMA repeat elongation. Testing of fetal tissues after elective pregnancy termination showed no somatic mosaicism in the CAG repeat length. This is the first report of molecular genetic analysis of multiple tissues in an affected fetus, and only the second report of prenatal diagnosis in SBMA.

  13. CAG repeat variants in the POLG1 gene encoding mtDNA polymerase-gamma and risk of breast cancer in African-American women.

    Science.gov (United States)

    Azrak, Sami; Ayyasamy, Vanniarajan; Zirpoli, Gary; Ambrosone, Christine; Bandera, Elisa V; Bovbjerg, Dana H; Jandorf, Lina; Ciupak, Gregory; Davis, Warren; Pawlish, Karen S; Liang, Ping; Singh, Keshav

    2012-01-01

    The DNA polymerase-gamma (POLG) gene, which encodes the catalytic subunit of enzyme responsible for directing mitochondrial DNA replication in humans, contains a polyglutamine tract encoded by CAG repeats of varying length. The length of the CAG repeat has been associated with the risk of testicular cancer, and other genomic variants that impact mitochondrial function have been linked to breast cancer risk in African-American (AA) women. We evaluated the potential role of germline POLG-CAG repeat variants in breast cancer risk in a sample of AA women (100 cases and 100 age-matched controls) who participated in the Women's Circle of Health Study, an ongoing multi-institutional, case-control study of breast cancer. Genotyping was done by fragment analysis in a blinded manner. Results from this small study suggest the possibility of an increased risk of breast cancer in women with minor CAG repeat variants of POLG, but no statistically significant differences in CAG repeat length were observed between cases and controls (multivariate-adjusted odds ratio 1.74; 95% CI, 0.49-6.21). Our study suggests that POLG-CAG repeat length is a potential risk factor for breast cancer that needs to be explored in larger population-based studies.

  14. CAG repeat variants in the POLG1 gene encoding mtDNA polymerase-gamma and risk of breast cancer in African-American women.

    Directory of Open Access Journals (Sweden)

    Sami Azrak

    Full Text Available The DNA polymerase-gamma (POLG gene, which encodes the catalytic subunit of enzyme responsible for directing mitochondrial DNA replication in humans, contains a polyglutamine tract encoded by CAG repeats of varying length. The length of the CAG repeat has been associated with the risk of testicular cancer, and other genomic variants that impact mitochondrial function have been linked to breast cancer risk in African-American (AA women. We evaluated the potential role of germline POLG-CAG repeat variants in breast cancer risk in a sample of AA women (100 cases and 100 age-matched controls who participated in the Women's Circle of Health Study, an ongoing multi-institutional, case-control study of breast cancer. Genotyping was done by fragment analysis in a blinded manner. Results from this small study suggest the possibility of an increased risk of breast cancer in women with minor CAG repeat variants of POLG, but no statistically significant differences in CAG repeat length were observed between cases and controls (multivariate-adjusted odds ratio 1.74; 95% CI, 0.49-6.21. Our study suggests that POLG-CAG repeat length is a potential risk factor for breast cancer that needs to be explored in larger population-based studies.

  15. Haplotype analysis of the CAG and CCG repeats in 21 Brazilian families with Huntington's disease.

    Science.gov (United States)

    Agostinho, Luciana de A; Rocha, Catielly F; Medina-Acosta, Enrique; Barboza, Hazel N; da Silva, Antônio F Alves; Pereira, Simão P F; da Silva, Iane Dos Santos; Paradela, Eduardo R; Figueiredo, André L dos S; Nogueira, Eduardo de M; Alvarenga, Regina M P; Hernan Cabello, Pedro; dos Santos, Suely R; Paiva, Carmen L A

    2012-12-01

    We studied the allelic profile of CAG and CCG repeats in 61 Brazilian individuals in 21 independent families affected by Huntington's disease (HD). Thirteen individuals had two normal alleles for HD, two had one mutable normal allele and no HD phenotype, and forty-six patients carried at least one expanded CAG repeat allele. Forty-five of these individuals had one expanded allele and one individual had one mutable normal allele (27 CAG repeats) and one expanded allele (48 CAG repeats). Eleven of these forty-five subjects had a mutant allele with reduced penetrance, and thirty-four patients had a mutant allele with complete penetrance. Inter- and intragenerational investigations of CAG repeats were also performed. We found a negative correlation between the number of CAG repeats and the age of disease onset (r=-0.84; Pdisease onset (r=0.06). We found 40 different haplotypes and the analysis showed that (CCG)(10) was linked to a CAG normal allele in 19 haplotypes and to expanded alleles in two haplotypes. We found that (CCG)(7) was linked to expanded CAG repeats in 40 haplotypes (95.24%) and (CCG)(10) was linked to expanded CAG repeats in only two haplotypes (4.76%). Therefore, (CCG)(7) was the most common allele in HD chromosomes in this Brazilian sample. It was also observed that there was a significant association of (CCG)(7) with the expanded CAG alleles (χ(2)=6.97, P=0.0084). Worldwide, the most common CCG alleles have 7 or 10 repeats. In Western Europe, (CCG)(7) is the most frequent allele, similarly to our findings.

  16. Association analysis of a highly polymorphic CAG Repeat in the human potassium channel gene KCNN3 and migraine susceptibility

    Directory of Open Access Journals (Sweden)

    Ovcaric Mick

    2005-09-01

    Full Text Available Abstract Background Migraine is a polygenic multifactorial disease, possessing environmental and genetic causative factors with multiple involved genes. Mutations in various ion channel genes are responsible for a number of neurological disorders. KCNN3 is a neuronal small conductance calcium-activated potassium channel gene that contains two polyglutamine tracts, encoded by polymorphic CAG repeats in the gene. This gene plays a critical role in determining the firing pattern of neurons and acts to regulate intracellular calcium channels. Methods The present association study tested whether length variations in the second (more 3' polymorphic CAG repeat in exon 1 of the KCNN3 gene, are involved in susceptibility to migraine with and without aura (MA and MO. In total 423 DNA samples from unrelated individuals, of which 202 consisted of migraine patients and 221 non-migraine controls, were genotyped and analysed using a fluorescence labelled primer set on an ABI310 Genetic Analyzer. Allele frequencies were calculated from observed genotype counts for the KCNN3 polymorphism. Analysis was performed using standard contingency table analysis, incorporating the chi-squared test of independence and CLUMP analysis. Results Overall, there was no convincing evidence that KCNN3 CAG lengths differ between Caucasian migraineurs and controls, with no significant difference in the allelic length distribution of CAG repeats between the population groups (P = 0.090. Also the MA and MO subtypes did not differ significantly between control allelic distributions (P > 0.05. The prevalence of the long CAG repeat (>19 repeats did not reach statistical significance in migraineurs (P = 0.15, nor was there a significant difference between the MA and MO subgroups observed compared to controls (P = 0.46 and P = 0.09, respectively, or between MA vs MO (P = 0.40. Conclusion This association study provides no evidence that length variations of the second polyglutamine array in

  17. Genes and pathways affected by CAG-repeat RNA-based toxicity in Drosophila.

    Science.gov (United States)

    Shieh, Shin-Yi; Bonini, Nancy M

    2011-12-15

    Spinocerebellar ataxia type 3 is one of the polyglutamine (polyQ) diseases, which are caused by a CAG-repeat expansion within the coding region of the associated genes. The CAG repeat specifies glutamine, and the expanded polyQ domain mutation confers dominant toxicity on the protein. Traditionally, studies have focused on protein toxicity in polyQ disease mechanisms. Recent findings, however, demonstrate that the CAG-repeat RNA, which encodes the toxic polyQ protein, also contributes to the disease in Drosophila. To provide insights into the nature of the RNA toxicity, we extracted brain-enriched RNA from flies expressing a toxic CAG-repeat mRNA (CAG100) and a non-toxic interrupted CAA/G mRNA repeat (CAA/G105) for microarray analysis. This approach identified 160 genes that are differentially expressed specifically in CAG100 flies. Functional annotation clustering analysis revealed several broad ontologies enriched in the CAG100 gene list, including iron ion binding and nucleotide binding. Intriguingly, transcripts for the Hsp70 genes, a powerful suppressor of polyQ and other human neurodegenerative diseases, were also upregulated. We therefore tested and showed that upregulation of heat shock protein 70 mitigates CAG-repeat RNA toxicity. We then assessed whether other modifiers of the pathogenic, expanded Ataxin-3 polyQ protein could also modify the CAG-repeat RNA toxicity. This approach identified the co-chaperone Tpr2, the transcriptional regulator Dpld, and the RNA-binding protein Orb2 as modifiers of both polyQ protein toxicity and CAG-repeat RNA-based toxicity. These findings suggest an overlap in the mechanisms of RNA and protein-based toxicity, providing insights into the pathogenicity of the RNA in polyQ disease.

  18. CAG-repeat variant in the polymerase γ gene and male infertility in the Chinese population: a meta-analysis.

    Science.gov (United States)

    Liu, Shu-Yuan; Zhang, Chang-Jun; Peng, Hai-Ying; Yao, Yu-Feng; Shi, Lei; Chen, Jin-Bao; Lin, Ke-Qin; Yu, Liang; Shi, Li; Huang, Xiao-Qin; Sun, Hao; Chu, Jia-You

    2011-03-01

    Several studies have reported a relationship between the length of the CAG-repeat in the polymerase γ (POLG) gene and male infertility. However, other studies have not reproduced this result. In our study, the POLG-CAG-repeat length was analyzed in 535 healthy individuals from six Chinese Han populations living in different provinces. The frequencies of 10-CAG alleles and genotypes were high (97.38 and 94.13%, respectively), with no significant difference among the six Chinese Han populations. Furthermore, we determined the distribution of the POLG-CAG-repeat in 150 infertile men and 126 fertile men. Our study suggested that the distributions of POLG-CAG-repeat alleles and genotypes were not significantly different between infertile (95.67 and 92.67%, respectively) and fertile men (97.22 and 94.44%, respectively). In a subsequent meta-analysis, combining our data with data from previous studies, a comparison of the CAG-repeat alleles in fertile versus infertile men showed no obvious risk for male infertility associated with any particular allele (pooled odds ratio (OR)=0.94; 95% confidence interval (CI): 0.60-1.48). The significance level was not attained with any of the following genetic models: homozygote comparison (not 10/not 10 versus 10/10: OR=1.34; 95% CI: 0.66-2.72), heterozygote comparison (10/not 10 versus 10/10: OR=1.04; 95% CI: 0.78-1.38), dominant model comparison (not 10/not 10+10/not 10 versus 10/10: OR=1.08; 95% CI: 0.79-1.47) and recessive genetic comparison (not 10/not 10 versus 10/not 10+10/10: OR=1.31; 95% CI: 0.68-2.55). In conclusion, there is no significant difference of the frequencies of POLG-CAG-repeat variants among six Chinese Han populations, and this polymorphism may not be associated with Chinese male infertility. On the basis of a meta-analysis, there is no obvious association between CAG-repeat variants of the POLG gene and male infertility.

  19. Zinc-finger directed double-strand breaks within CAG repeat tracts promote repeat instability in human cells.

    Science.gov (United States)

    Mittelman, David; Moye, Christopher; Morton, Jason; Sykoudis, Kristen; Lin, Yunfu; Carroll, Dana; Wilson, John H

    2009-06-16

    Expanded triplet repeats have been identified as the genetic basis for a growing number of neurological and skeletal disorders. To examine the contribution of double-strand break repair to CAG x CTG repeat instability in mammalian systems, we developed zinc finger nucleases (ZFNs) that recognize and cleave CAG repeat sequences. Engineered ZFNs use a tandem array of zinc fingers, fused to the FokI DNA cleavage domain, to direct double-strand breaks (DSBs) in a site-specific manner. We first determined that the ZFNs cleave CAG repeats in vitro. Then, using our previously described tissue culture assay for identifying modifiers of CAG repeat instability, we found that transfection of ZFN-expression vectors induced up to a 15-fold increase in changes to the CAG repeat in human and rodent cell lines, and that longer repeats were much more sensitive to cleavage than shorter ones. Analysis of individual colonies arising after treatment revealed a spectrum of events consistent with ZFN-induced DSBs and dominated by repeat contractions. We also found that expressing a dominant-negative form of RAD51 in combination with a ZFN, dramatically reduced the effect of the nuclease, suggesting that DSB-induced repeat instability is mediated, in part, through homology directed repair. These studies identify a ZFN as a useful reagent for characterizing the effects of DSBs on CAG repeats in cells.

  20. Analysis of the trinucleotide CAG repeat from the human mitochondrial DNA polymerase gene in healthy and diseased individuals.

    Science.gov (United States)

    Rovio, A; Tiranti, V; Bednarz, A L; Suomalainen, A; Spelbrink, J N; Lecrenier, N; Melberg, A; Zeviani, M; Poulton, J; Foury, F; Jacobs, H T

    1999-01-01

    The human nuclear gene (POLG) for the catalytic subunit of mitochondrial DNA polymerase (DNA polymerase gamma) contains a trinucleotide CAG microsatellite repeat within the coding sequence. We have investigated the frequency of different repeat-length alleles in populations of diseased and healthy individuals. The predominant allele of 10 CAG repeats was found at a very similar frequency (approximately 88%) in both Finnish and ethnically mixed population samples, with homozygosity close to the equilibrium prediction. Other alleles of between 5 and 13 repeat units were detected, but no larger, expanded alleles were found. A series of 51 British myotonic dystrophy patients showed no significant variation from controls, indicating an absence of generalised CAG repeat instability. Patients with a variety of molecular lesions in mtDNA, including sporadic, clonal deletions, maternally inherited point mutations, autosomally transmitted mtDNA depletion and autosomal dominant multiple deletions showed no differences in POLG trinucleotide repeat-length distribution from controls. These findings rule out POLG repeat expansion as a common pathogenic mechanism in disorders characterised by mitochondrial genome instability.

  1. CAG repeat polymorphism in the androgen receptor (AR) gene of SBMA patients and a control group.

    Science.gov (United States)

    Sułek, Anna; Hoffman-Zacharska, Dorota; Krysa, Wioletta; Szirkowiec, Walentyna; Fidziańska, Elzbieta; Zaremba, Jacek

    2005-01-01

    Spinobulbar muscular atrophy (SBMA) is an X-linked form of motor neuron disease characterized by progressive atrophy of the muscles, dysphagia, dysarthria and mild androgen insensitivity. SBMA is caused by CAG repeat expansion in the androgen receptor gene. CAG repeat polymorphism was analysed in a Polish control group (n = 150) and patients suspected of SBMA (n = 60). Normal and abnormal ranges of CAG repeats were established in the control group and in 21 patients whose clinical diagnosis of SBMA was molecularly confirmed. The ranges are similar to those reported for other populations.

  2. Genes and pathways affected by CAG-repeat RNA-based toxicity in Drosophila

    OpenAIRE

    Shieh, Shin-Yi; Bonini, Nancy M.

    2011-01-01

    Spinocerebellar ataxia type 3 is one of the polyglutamine (polyQ) diseases, which are caused by a CAG-repeat expansion within the coding region of the associated genes. The CAG repeat specifies glutamine, and the expanded polyQ domain mutation confers dominant toxicity on the protein. Traditionally, studies have focused on protein toxicity in polyQ disease mechanisms. Recent findings, however, demonstrate that the CAG-repeat RNA, which encodes the toxic polyQ protein, also contributes to the ...

  3. Problems and solutions for the analysis of somatic CAG repeat expansion and their relationship to Huntington's disease toxicity.

    Science.gov (United States)

    Budworth, Helen; McMurray, Cynthia T

    2016-01-01

    Huntington's Disease is caused by inheritance of a single disease-length allele harboring an expanded CAG repeat, which continues to expand in somatic tissues with age. Whether somatic expansion contributed to toxicity was unknown. From extensive work from multiple laboratories, it has been made clear that toxicity depended on length of the inherited allele, but whether preventing or delaying somatic repeat expansion in vivo would be beneficial was unknown, since the inherited disease allele was still expressed. In Budworth et al., we provided definitive evidence that suppressing the somatic expansion in mice substantially delays disease onset in littermates that inherit the same disease-length allele. This key discovery opens the door for therapeutic approaches targeted at stopping or shortening the CAG tract during life. The analysis was difficult and, at times, non-standard. Here, we take the opportunity to discuss the challenges, the analytical solutions, and to address some controversial issues with respect to expansion biology.

  4. The DRPLA CAG repeats in an Italian population sample: evaluation of the polymorphism for forensic applications.

    Science.gov (United States)

    Pelotti, S; Mantovani, V; Esposti, P D; D'Apote, L; Bragliani, M; Maiolini, E; Abbondanza, A; Pappalardo, G

    1998-03-01

    The DRPLA CAG repeats polymorphism has been studied in an Italian population sample. PCR amplification, manual PAGE and silver staining were employed. A total of 16 different alleles, spanning the range from 5 to 21 CAG triplettes, was observed. The heterozygosity was 0.81 and no significant deviation from Hardy-Weinberg equilibrium was found 81 meioses from parentage testing were also analyzed and a Mendelian pattern of inheritance was observed in all cases. In addition, we could successfully type DRPLA locus in some forensic specimens, 1 ng of DNA allowing clear definition of alleles. The authors conclude that the DRPLA CAG repeats analysis may be useful for forensic applications.

  5. 男乳癌与 AR 基因 CAG 重复多态性的相关性研究%Related research of male breast cancer and CAG repeat polymorphism of AR gene

    Institute of Scientific and Technical Information of China (English)

    崔佳琳; 黄睿; 姜永冬; 韩继广; 牛明; 魏巍; 郑伟; 宋燕妮

    2015-01-01

    目的:探讨雄激素受体( AR)基因外显子CAG重复频数多态性与男性乳腺癌(男乳癌)发病风险的关系。方法研究对象为40例男性乳腺癌患者和40例男性健康者,从外周血提取DNA,对AR基因外显子CAG编码序列进行PCR扩增、测序和计算CAG重复频数,用χ2检验和Logistic回归分析AR基因CAG重复频数长度对男乳癌发病风险的影响。结果男性乳腺癌病例组和对照组CAG重复频数长度存在差异,其差异具有统计学意义,CAG重复频数长度超过22男性乳腺癌发病风险是重复频数长度少于21的3.52倍(OR=3.52,P=0.036)。结论 AR基因CAG重复频数长度是预测男性乳腺癌发病风险的指标,较长(超过22)的CAG重复序列可增加男乳癌的发病风险。%Objectiv e To investigate the correlation between ( CAG) n repeat polymorphism of androgen receptor(AR)geneandmalebreastcancer.Methods 40casesofmalebreastcancerand40controlswerecol-lected.DNA was extracted from peripheral blood and the AR gene CAG coding exon sequences for PCR amplifica -tion,sequencing and calculated the number of CAG repeats frquency .χ2 test and Logistic regression analysis were used assess the AR gene CAG repeat length frequency affect the number of male breast cancer risk .Results There was statistically significant difference in male breast cancer cases and controls the number of CAG repeat length frequency.Man for whom the(CAG)n≥22 repeat sequence had 3.52 times risk of male breast compared (CAG)n≤22(OR=3.52,P=0.036).Conclusion AR gene CAG repeat length is a predictor of the frequency of male breast cancer risk .Longer CAG repeats can increase the risk of male breast cancer .

  6. MSH3 polymorphisms and protein levels affect CAG repeat instability in Huntington's disease mice.

    Science.gov (United States)

    Tomé, Stéphanie; Manley, Kevin; Simard, Jodie P; Clark, Greg W; Slean, Meghan M; Swami, Meera; Shelbourne, Peggy F; Tillier, Elisabeth R M; Monckton, Darren G; Messer, Anne; Pearson, Christopher E

    2013-01-01

    Expansions of trinucleotide CAG/CTG repeats in somatic tissues are thought to contribute to ongoing disease progression through an affected individual's life with Huntington's disease or myotonic dystrophy. Broad ranges of repeat instability arise between individuals with expanded repeats, suggesting the existence of modifiers of repeat instability. Mice with expanded CAG/CTG repeats show variable levels of instability depending upon mouse strain. However, to date the genetic modifiers underlying these differences have not been identified. We show that in liver and striatum the R6/1 Huntington's disease (HD) (CAG)∼100 transgene, when present in a congenic C57BL/6J (B6) background, incurred expansion-biased repeat mutations, whereas the repeat was stable in a congenic BALB/cByJ (CBy) background. Reciprocal congenic mice revealed the Msh3 gene as the determinant for the differences in repeat instability. Expansion bias was observed in congenic mice homozygous for the B6 Msh3 gene on a CBy background, while the CAG tract was stabilized in congenics homozygous for the CBy Msh3 gene on a B6 background. The CAG stabilization was as dramatic as genetic deficiency of Msh2. The B6 and CBy Msh3 genes had identical promoters but differed in coding regions and showed strikingly different protein levels. B6 MSH3 variant protein is highly expressed and associated with CAG expansions, while the CBy MSH3 variant protein is expressed at barely detectable levels, associating with CAG stability. The DHFR protein, which is divergently transcribed from a promoter shared by the Msh3 gene, did not show varied levels between mouse strains. Thus, naturally occurring MSH3 protein polymorphisms are modifiers of CAG repeat instability, likely through variable MSH3 protein stability. Since evidence supports that somatic CAG instability is a modifier and predictor of disease, our data are consistent with the hypothesis that variable levels of CAG instability associated with polymorphisms of

  7. CAG repeat polymorphisms in the androgen receptor and breast cancer risk in women: a meta-analysis of 17 studies

    Directory of Open Access Journals (Sweden)

    Mao Q

    2015-08-01

    Full Text Available Qixing Mao,1–3,* Mantang Qiu,1–3,* Gaochao Dong,3 Wenjie Xia,1–3 Shuai Zhang,1,3 Youtao Xu,1,3 Jie Wang,3 Yin Rong,1,3 Lin Xu,1,3 Feng Jiang1,3 1Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Institute of Jiangsu Province, 2Fourth Clinical College of Nanjing Medical University, 3Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing, People’s Republic of China *These authors contributed equally to this work Abstract: The association between polymorphic CAG repeats in the androgen receptor gene in women and breast cancer susceptibility has been studied extensively. However, the conclusions regarding this relationship remain conflicting. The purpose of this meta-analysis was to identify whether androgen receptor CAG repeat lengths were related to breast cancer susceptibility. The MEDLINE, PubMed, and EMBASE databases were searched through to December 2014 to identify eligible studies. Data and study quality were rigorously assessed by two investigators according to the Newcastle-Ottawa Quality Assessment Scale. The publication bias was assessed by the Begg’s test. Seventeen eligible studies were included in this meta-analysis. The overall analysis suggested no association between CAG polymorphisms and breast cancer risk (odds ratio [OR] 1.031, 95% confidence interval [CI] 0.855–1.245. However, in the subgroup analysis, we observed that long CAG repeats significantly increased the risk of breast cancer in the Caucasian population (OR 1.447, 95% CI 1.089–1.992. Additionally, the risk was significantly increased in Caucasian women carrying two alleles with CAG repeats ≥22 units compared with those with two shorter alleles (OR 1.315, 95% CI 1.014–1.707. These findings suggest that long CAG repeats increase the risk of breast cancer in Caucasian women. However, larger scale case-control studies are needed to validate our results. Keywords: androgen, CAG repeat polymorphism, women

  8. Characterization of conservative somatic instability of the CAG repeat region in Huntington`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, F.V.; Calikoglu, A.S.; Whetsell, L.H. [H.A. Chapman Research Institute of Medical Genetics, Tulsa, OK (United States)

    1994-09-01

    Instability and enlargement of a CAG repeat region at the beginning of the huntingtin gene (IT-15) has been linked with Huntington`s disease. The CAG repeat size shows a highly significant correlation with age-of-onset of clinicial features in individuals with 40 or more repeats who have Huntington disease. The clinical status of nonsymptomatic individuals with 30 to 39 CAG repeats is considered ambiguous. In order to define more carefully the nature of the HD expansion instability, we examined patients in our HD population using a discriminating fluorescence-based PCR approach. The degree of somatic mutation increases with both earlier age of onset and the size of the inherited allele. A single prominent band one repeat larger than the index peak was typical in individuals with 40-41 CAG repeats. Three to four larger bands are typically discerned in individuals with 50 or more repeats. In an extreme example, an individual with approximately 95 repeats had at least 8 prominent bands. Plotting the degree of somatic mutation relative to the size of the HD allele shows somatic mutation activity increases with size. By this approach 40-60% of the alleles in a 40-41 CAG repeat HD loci is represented in the primary allele. In contrast, the primary allele represents a relatively minor proportion of the total alleles for expansions greater than 50 CAG repeats (10-20%). The limited range of somatic mutation suggest that the instability is restricted to very early stages of embryogenesis before tissue development diverges or that persistent somatic instability occurs at a slow rate. Therefore, the properties of somatic instability in Huntington`s disease have aspects that are both in common but also different from that found in other trinucleotide repeat expanding diseases such as myotonic muscular dystrophy and fragile X syndrome.

  9. RAI1 point mutations, CAG repeat variation, and SNP analysis in non-deletion Smith-Magenis syndrome.

    Science.gov (United States)

    Bi, Weimin; Saifi, G Mustafa; Girirajan, Santhosh; Shi, Xin; Szomju, Barbara; Firth, Helen; Magenis, R Ellen; Potocki, Lorraine; Elsea, Sarah H; Lupski, James R

    2006-11-15

    Smith-Magenis syndrome (SMS) is a multiple congenital anomalies/mental retardation disorder characterized by distinct craniofacial features and neurobehavioral abnormalities usually associated with an interstitial deletion in 17p11.2. Heterozygous point mutations in the retinoic acid induced 1 gene (RAI1) have been reported in nine SMS patients without a deletion detectable by fluorescent in situ hybridization (FISH), implicating RAI1 haploinsufficiency as the cause of the major clinical features in SMS. All of the reported point mutations are unique and de novo. RAI1 contains a polymorphic CAG repeat and encodes a plant homeo domain (PHD) zinc finger-containing transcriptional regulator. We report a novel RAI1 frameshift mutation, c.3103delC, in a non-deletion patient with many SMS features. The deletion of a single cytosine occurs in a heptameric C-tract (CCCCCCC), the longest mononucleotide repeat in the RAI1 coding region. Interestingly, we had previously reported a frameshift mutation, c.3103insC, in the same mononucleotide repeat. Furthermore, all five single base frameshift mutations preferentially occurred in polyC but not polyG tracts. We also investigated the distribution of the polymorphic CAG repeats in both the normal population and the SMS patients as one potential molecular mechanism for variability of clinical expression. In this limited data set, there was no significant association between the length of CAG repeats and the SMS phenotype. However, we identified a 5-year-old girl with an apparent SMS phenotype who was a compound heterozygote for an RAI1 missense mutation inherited from her father and a polyglutamine repeat of 18 copies, representing the largest known CAG repeat in this gene, inherited from her mother.

  10. Sequencing analysis of the spinal bulbar muscular atrophy CAG expansion reveals absence of repeat interruptions.

    Science.gov (United States)

    Fratta, Pietro; Collins, Toby; Pemble, Sally; Nethisinghe, Suran; Devoy, Anny; Giunti, Paola; Sweeney, Mary G; Hanna, Michael G; Fisher, Elizabeth M C

    2014-02-01

    Trinucleotide repeat disorders are a heterogeneous group of diseases caused by the expansion, beyond a pathogenic threshold, of unstable DNA tracts in different genes. Sequence interruptions in the repeats have been described in the majority of these disorders and may influence disease phenotype and heritability. Spinal bulbar muscular atrophy (SBMA) is a motor neuron disease caused by a CAG trinucleotide expansion in the androgen receptor (AR) gene. Diagnostic testing and previous research have relied on fragment analysis polymerase chain reaction to determine the AR CAG repeat size, and have therefore not been able to assess the presence of interruptions. We here report a sequencing study of the AR CAG repeat in a cohort of SBMA patients and control subjects in the United Kingdom. We found no repeat interruptions to be present, and we describe differences between sequencing and traditional sizing methods.

  11. MSH3 polymorphisms and protein levels affect CAG repeat instability in Huntington's disease mice.

    Directory of Open Access Journals (Sweden)

    Stéphanie Tomé

    Full Text Available Expansions of trinucleotide CAG/CTG repeats in somatic tissues are thought to contribute to ongoing disease progression through an affected individual's life with Huntington's disease or myotonic dystrophy. Broad ranges of repeat instability arise between individuals with expanded repeats, suggesting the existence of modifiers of repeat instability. Mice with expanded CAG/CTG repeats show variable levels of instability depending upon mouse strain. However, to date the genetic modifiers underlying these differences have not been identified. We show that in liver and striatum the R6/1 Huntington's disease (HD (CAG∼100 transgene, when present in a congenic C57BL/6J (B6 background, incurred expansion-biased repeat mutations, whereas the repeat was stable in a congenic BALB/cByJ (CBy background. Reciprocal congenic mice revealed the Msh3 gene as the determinant for the differences in repeat instability. Expansion bias was observed in congenic mice homozygous for the B6 Msh3 gene on a CBy background, while the CAG tract was stabilized in congenics homozygous for the CBy Msh3 gene on a B6 background. The CAG stabilization was as dramatic as genetic deficiency of Msh2. The B6 and CBy Msh3 genes had identical promoters but differed in coding regions and showed strikingly different protein levels. B6 MSH3 variant protein is highly expressed and associated with CAG expansions, while the CBy MSH3 variant protein is expressed at barely detectable levels, associating with CAG stability. The DHFR protein, which is divergently transcribed from a promoter shared by the Msh3 gene, did not show varied levels between mouse strains. Thus, naturally occurring MSH3 protein polymorphisms are modifiers of CAG repeat instability, likely through variable MSH3 protein stability. Since evidence supports that somatic CAG instability is a modifier and predictor of disease, our data are consistent with the hypothesis that variable levels of CAG instability associated with

  12. Positive Selection of a Pre-Expansion CAG Repeat of the Human SCA2 Gene.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available A region of approximately one megabase of human Chromosome 12 shows extensive linkage disequilibrium in Utah residents with ancestry from northern and western Europe. This strikingly large linkage disequilibrium block was analyzed with statistical and experimental methods to determine whether natural selection could be implicated in shaping the current genome structure. Extended Haplotype Homozygosity and Relative Extended Haplotype Homozygosity analyses on this region mapped a core region of the strongest conserved haplotype to the exon 1 of the Spinocerebellar ataxia type 2 gene (SCA2. Direct DNA sequencing of this region of the SCA2 gene revealed a significant association between a pre-expanded allele [(CAG(8CAA(CAG(4CAA(CAG(8] of CAG repeats within exon 1 and the selected haplotype of the SCA2 gene. A significantly negative Tajima's D value (-2.20, p < 0.01 on this site consistently suggested selection on the CAG repeat. This region was also investigated in the three other populations, none of which showed signs of selection. These results suggest that a recent positive selection of the pre-expansion SCA2 CAG repeat has occurred in Utah residents with European ancestry.

  13. Positive selection of a pre-expansion CAG repeat of the human SCA2 gene.

    Directory of Open Access Journals (Sweden)

    Fuli Yu

    2005-09-01

    Full Text Available A region of approximately one megabase of human Chromosome 12 shows extensive linkage disequilibrium in Utah residents with ancestry from northern and western Europe. This strikingly large linkage disequilibrium block was analyzed with statistical and experimental methods to determine whether natural selection could be implicated in shaping the current genome structure. Extended Haplotype Homozygosity and Relative Extended Haplotype Homozygosity analyses on this region mapped a core region of the strongest conserved haplotype to the exon 1 of the Spinocerebellar ataxia type 2 gene (SCA2. Direct DNA sequencing of this region of the SCA2 gene revealed a significant association between a pre-expanded allele [(CAG8CAA(CAG4CAA(CAG8] of CAG repeats within exon 1 and the selected haplotype of the SCA2 gene. A significantly negative Tajima's D value (-2.20, p < 0.01 on this site consistently suggested selection on the CAG repeat. This region was also investigated in the three other populations, none of which showed signs of selection. These results suggest that a recent positive selection of the pre-expansion SCA2 CAG repeat has occurred in Utah residents with European ancestry.

  14. Diversity in the androgen receptor CAG repeat has been shaped by a multistep mutational mechanism.

    Science.gov (United States)

    Santos, Diana; Pimenta, João; Wong, Virginia C N; Amorim, António; Martins, Sandra

    2014-10-01

    The androgen receptor (AR) gene encodes a type of nuclear receptor that functions as a steroid-hormone activated transcription factor. In its coding region, AR includes a CAG repeat, which has been intensely studied due to the inverse correlation between repeat size and AR transcriptional activity. Several studies have reported different (CAG)n sizes associated with the risk of androgen-linked diseases. We aimed at clarifying the mechanisms on the origin of newly CAG sized alleles through a strategy involving the analysis of the associated haplotype diversity. We genotyped 374 control individuals of European and Asian ancestry, and reconstructed the haplotypes associated with the CAG repeat, defined by 10 SNPs and 6 flanking STRs. The most powerful SNPs to tag AR lineages are rs7061037-rs12012620 and rs34191540-rs6625187-rs2768578 in Europeans and Asians, respectively. In the most frequent AR lineage, (CAG)18 alleles seem to have been generated by a multistep mutation mechanism, most probably from longer alleles. We further noticed that the DXS1194-DXS1111 haplotype, in linkage disequilibrium with AR-(CAG)n expanded alleles responsible for spinal bulbar muscular atrophy (SBMA), is rare among our controls; however, the haplotype strategy here described may be used to clarify the origin of expansions in other populations, as in future association studies.

  15. Induced pluripotent stem cells from patients with Huntington's disease show CAG-repeat-expansion-associated phenotypes.

    Science.gov (United States)

    2012-08-03

    Huntington's disease (HD) is an inherited neurodegenerative disorder caused by an expanded stretch of CAG trinucleotide repeats that results in neuronal dysfunction and death. Here, The HD Consortium reports the generation and characterization of 14 induced pluripotent stem cell (iPSC) lines from HD patients and controls. Microarray profiling revealed CAG-repeat-expansion-associated gene expression patterns that distinguish patient lines from controls, and early onset versus late onset HD. Differentiated HD neural cells showed disease-associated changes in electrophysiology, metabolism, cell adhesion, and ultimately cell death for lines with both medium and longer CAG repeat expansions. The longer repeat lines were however the most vulnerable to cellular stressors and BDNF withdrawal, as assessed using a range of assays across consortium laboratories. The HD iPSC collection represents a unique and well-characterized resource to elucidate disease mechanisms in HD and provides a human stem cell platform for screening new candidate therapeutics.

  16. Isolation and characterization of human cerebellum cDNAs containing polymorphic CAG trinucleotide repeats

    Energy Technology Data Exchange (ETDEWEB)

    Igarashi, S.; Onodera, O.; Tanaka, H. [Niigata Univ. (Japan)] [and others

    1994-09-01

    It has been discovered that neurologic diseases such as X linked spinal and bulbar muscular atrophy, Huntington`s disease, spinocerebellar ataxia type 1 (SCA1), and dentatorubral-pallidoluysian atrophy (DRPLA) are caused by unstable expansions of CAG repeats, which shed a light on a new mechanism of human hereditary diseases. The genetic anticipation, a common genetic feature in these diseases, can be explained by the trinucleotide repeat expansions, and an inverse correlation between the ages of onset and the numbers of trinucleotide repeats is demonstrated in these diseases. Furthermore, there have been diseases such as spinocerebellar ataxia 2 (SCA2) and Machado-Joseph disease showing similar genetic anticipation, which suggests that their causative mutations are unstable expansions of trinucleotide repeats. To identify candidate genes for neurodegenerative diseases which are expressed in human cerebellum and contain CAG repeats, we screened a human cerebellum cDNA library with an oligonucleotide (CAG){sub 10}, labelled with [{gamma}{sup 32}P]ATP. Out of 78 clones we have isolated, 43 clones were partially sequenced and 31 clones were shown to contain CAG or CTG tinucleotide repeats. From homology searches, 12 of the 59 clones were identified to contain known sequences including human MAR/SAR DNA binding protein, human glial fibrillary acidic protein, human myelin transcription factor 1, human neuronal growth protein 43 and human myocyte-specific enhancer 2. From 6 clones out of the 43 novel genes, we were able to develop primer pairs flanking CAG repeats and determined chromosomal localizations with human and rodent hybrid mapping panels. These CAG repeats were shown to be polymorphic and mapped to 1, 15, 17 and 18. These novel cDNAs will be useful as candidate genes for hereditary neurologic diseases showing genetic anticipation.

  17. Clinical features of Chinese patients with Huntington's disease carrying CAG repeats beyond 60 within HTT gene.

    Science.gov (United States)

    Liu, Z-J; Sun, Y-M; Ni, W; Dong, Y; Shi, S-S; Wu, Z-Y

    2014-02-01

    Patients with Huntington's disease (HD) carrying CAG repeats beyond 60 are less frequently seen and clinical features of them have been rarely reported. We identified four unrelated patients carrying CAG repeats beyond 60 (84.0 ± 13.76, ranging from 74 to 104) from 119 Chinese HD patients via direct sequencing. These four were all early onset with a mean age at presenting symptom of 9.8 ± 1.71 years. Paternal transmission was found in three of them and the fourth was apparently sporadic. In addition, they had atypical onset symptoms including epilepsy, intellectual decline, tics and walking instability, which might lead the clinicians to make the wrong diagnosis in the early stage of disease. Our work explores clinical features of Chinese HD patients with an expanded CAG repeat over 60 and may help the clinicians make a correct diagnosis in the early stage of disease.

  18. The CAG repeat polymorphism of androgen receptor gene and prostate cancer: a meta-analysis.

    Science.gov (United States)

    Gu, Mingliang; Dong, Xiaoqun; Zhang, Xuezhi; Niu, Wenquan

    2012-03-01

    The association between the polymorphic CAG repeat in androgen receptor gene (AR) and prostate cancer susceptibility has been studied extensively. However, the results are contradictory. The purpose of our meta-analysis was to investigate whether CAG repeat related to prostate cancer risk and had genetic heterogeneity across different geographic regions and study designs. Random-effects model was performed irrespective of between-study heterogeneity. Data and study quality were assessed in duplicate. Publication bias was assessed by the fail-safe number and Egger's test. There were 16 (patients/controls: 2972/3792), 19 (3835/4908) and 12 (3372/2631) study groups for comparisons of ≥ 20, 22 and 23 repeats of CAG sequence, respectively. Compared with CAG repeat repeats had 21% (95% CI: 0.61-1.02; P = 0.076), 5% (95% CI: 0.81-1.11; P = 0.508) and 5% (95% CI: 0.76-1.20; P = 0.681) decreased risk of prostate cancer. After classifying studies by geographic areas, carriers of ≥ 20 repeats had 11% decreased risk in populations from USA, 53% from Europe, and 20% from Asia (P > 0.05), whereas comparison of ≥ 23 repeats with others generated a significant prediction in European populations (OR = 1.17; P = 0.039). Stratification by study designs revealed no material changes in risk estimation. Meta-regression analysis found no significant sources of between-study heterogeneity for age, study design and geographic region for all comparisons. There was no identified publication bias. Taken together, our results demonstrated that AR CAG repeat polymorphism with ≥ 20 repeats might confer a protective effect among the prostate cancer patients with 45 years older but not all the prostate cancer patients.

  19. CAG repeat size correlates to electrophysiological motor and sensory phenotypes in SBMA.

    Science.gov (United States)

    Suzuki, Keisuke; Katsuno, Masahisa; Banno, Haruhiko; Takeuchi, Yu; Atsuta, Naoki; Ito, Mizuki; Watanabe, Hirohisa; Yamashita, Fumitada; Hori, Norio; Nakamura, Tomohiko; Hirayama, Masaaki; Tanaka, Fumiaki; Sobue, Gen

    2008-01-01

    Spinal and bulbar muscular atrophy (SBMA) is an adult-onset, lower motor neuron disease caused by an aberrant elongation of a CAG repeat in the androgen receptor (AR) gene. The main symptoms are weakness and atrophy of bulbar, facial and limb muscles, but sensory disturbances are frequently found in SBMA patients. Motor symptoms have been attributed to the accumulation of mutant AR in the nucleus of lower motor neurons, which is more profound in patients with a longer CAG repeat. We examined nerve conduction properties including F-waves in a total of 106 patients with genetically confirmed SBMA (mean age at data collection = 53.8 years; range = 31-75 years) and 85 control subjects. Motor conduction velocities (MCV), compound muscle action potentials (CMAP), sensory conduction velocities (SCV) and sensory nerve action potentials (SNAP) were significantly decreased in all nerves examined in the SBMA patients compared with that in the normal controls, indicating that axonal degeneration is the primary process in both motor and sensory nerves. More profound abnormalities were observed in the nerves of the upper limbs than in those of the lower limbs. F-waves in the median nerve were absent in 30 of 106 cases (28.3%), but no cases of absent F-waves were observed in the tibial nerve. From an analysis of the relationship between CMAPs and SNAPs, patients were identified with different electrophysiological phenotypes: motor-dominant, sensory-dominant and non-dominant phenotypes. The CAG repeat size and the age at onset were significantly different among the patients with motor- and sensory-dominant phenotypes, indicating that a longer CAG repeat is more closely linked to the motor-dominant phenotype and a shorter CAG repeat is more closely linked to the sensory-dominant phenotype. Furthermore, when we classified the patients by CAG repeat size, CMAP values showed a tendency to be decreased in patients with a longer CAG repeat (> or =47), while SNAPs were significantly

  20. Naphthyridine-Benzoazaquinolone: Evaluation of a Tricyclic System for the Binding to (CAG)n Repeat DNA and RNA.

    Science.gov (United States)

    Li, Jinxing; Sakata, Akihiro; He, Hanping; Bai, Li-Ping; Murata, Asako; Dohno, Chikara; Nakatani, Kazuhiko

    2016-07-05

    The expansion of CAG repeats in the human genome causes the neurological disorder Huntington's disease. The small-molecule naphthyridine-azaquinolone NA we reported earlier bound to the CAG/CAG motif in the hairpin structure of the CAG repeat DNA. In order to investigate and improve NA-binding to the CAG repeat DNA and RNA, we conducted systematic structure-binding studies of NA to CAG repeats. Among the five new NA derivatives we synthesized, surface plasmon resonance (SPR) assay showed that all of the derivatives modified from amide linkages in NA to a carbamate linkage failed to bind to CAG repeat DNA and RNA. One derivative, NBzA, modified by incorporating an additional ring to the azaquinolone was found to bind to both d(CAG)9 and r(CAG)9 . NBzA binding to d(CAG)9 was similar to NA binding in terms of large changes in the SPR assay and circular dichroism (CD) as well as pairwise binding, as assessed by electron spray ionization time-of-flight (ESI-TOF) mass spectrometry. For the binding to r(CAG)9 , both NA and NBzA showed stepwise binding in ESI-TOF MS, and NBzA-binding to r(CAG)9 induced more extensive conformational change than NA-binding. The tricyclic system in NBzA did not show significant effects on the binding, selectivity, and translation, but provides a large chemical space for further modification to gain higher affinity and selectivity. These studies revealed that the linker structure in NA and NBzA was suitable for the binding to CAG DNA and RNA, and that the tricyclic benzoazaquinolone did not interfere with the binding.

  1. Role of androgen receptor CAG repeat polymorphism and X-inactivation in the manifestation of recurrent spontaneous abortions in Indian women.

    Directory of Open Access Journals (Sweden)

    Meka Aruna

    Full Text Available The aim of the present study was to investigate the role of CAG repeat polymorphism and X-chromosome Inactivation (XCI pattern in Recurrent Spontaneous Abortions among Indian women which has not been hitherto explored. 117 RSA cases and 224 Controls were included in the study. Cases were recruited from two different hospitals--Lakshmi Fertility Clinic, Nellore and Fernandez Maternity Hospital, Hyderabad. Controls were roughly matched for age, ethnicity and socioeconomic status. The CAG repeats of the Androgen Receptor gene were genotyped using a PCR-based assay and were analysed using the GeneMapper software to determine the CAG repeat length. XCI analysis was also carried out to assess the inactivation percentages. RSA cases had a significantly greater frequency of allele sizes in the polymorphic range above 19 repeats (p = 0.006, which is the median value of the controls, and in the biallelic mean range above 21 repeats (p = 0.002. We found no evidence of abnormal incidence of skewed X-inactivation. We conclude that longer CAG repeat lengths are associated with increased odds for RSA with statistical power estimated to be ∼90%.

  2. Meta-analysis of relationship between androgen receptor CAG repeats length polymorphism and the polycystic ovary syndrome%雄激素受体(CAG)n基因多态性与多囊卵巢综合征相关性的Meta分析

    Institute of Scientific and Technical Information of China (English)

    余瑞梅; 邱娜璇; 陈春敏

    2015-01-01

    目的 评价雄激素受体(androgen receptor,AR) (CAG)n基因多态性与多囊卵巢综合征(polycystic ovary syndrome,PCOS)易感性的相关性.方法 检索Pubmed、Embase、CNKI、VIP、万方数据库,英文检索词为androgen receptor,polycystic ovarian syndrome,中文检索词为雄激素受体和多囊卵巢综合征,收集有关AR (CAG)n基因多态性与PCOS易感性的病例对照研究,进行Meta分析.结果 共纳入12篇文献,PCOS组1 697例,对照组(健康女性)1 984例.Meta分析结果显示,PCOS组与对照组间AR (CAG)n重复序列长度比较,差异无统计学意义[标准化均数差(SMD)=-0.05,95%CI:-0.19~0.08,P=0.440].PCOS患者中,高雄激素血症(hyperandrogenism,HA)患者与非HA患者间AR (CAG)n重复序列长度比较,差异无统计学意义(SMD=0.56,95%CI:-0.13~1.25,P=0.110).结论 AR (CAG)n基因多态性可能与P-COS及其并发的高雄激素血症的发生无关联.

  3. Targeting CAG repeat RNAs reduces Huntington’s disease phenotype independently of huntingtin levels

    Science.gov (United States)

    Rué, Laura; Bañez-Coronel, Mónica; Creus-Muncunill, Jordi; Giralt, Albert; Alcalá-Vida, Rafael; Mentxaka, Gartze; Kagerbauer, Birgit; Aranda, Zeus; Venturi, Veronica; Pérez-Navarro, Esther; Estivill, Xavier

    2016-01-01

    Huntington’s disease (HD) is a polyglutamine disorder caused by a CAG expansion in the Huntingtin (HTT) gene exon 1. This expansion encodes a mutant protein whose abnormal function is traditionally associated with HD pathogenesis; however, recent evidence has also linked HD pathogenesis to RNA stable hairpins formed by the mutant HTT expansion. Here, we have shown that a locked nucleic acid–modified antisense oligonucleotide complementary to the CAG repeat (LNA-CTG) preferentially binds to mutant HTT without affecting HTT mRNA or protein levels. LNA-CTGs produced rapid and sustained improvement of motor deficits in an R6/2 mouse HD model that was paralleled by persistent binding of LNA-CTG to the expanded HTT exon 1 transgene. Motor improvement was accompanied by a pronounced recovery in the levels of several striatal neuronal markers severely impaired in R6/2 mice. Furthermore, in R6/2 mice, LNA-CTG blocked several pathogenic mechanisms caused by expanded CAG RNA, including small RNA toxicity and decreased Rn45s expression levels. These results suggest that LNA-CTGs promote neuroprotection by blocking the detrimental activity of CAG repeats within HTT mRNA. The present data emphasize the relevance of expanded CAG RNA to HD pathogenesis, indicate that inhibition of HTT expression is not required to reverse motor deficits, and further suggest a therapeutic potential for LNA-CTG in polyglutamine disorders. PMID:27721240

  4. DNA-labelled cytidine assay for the quantification of CAG repeats.

    Science.gov (United States)

    Pérez-Bello, Dannelys; Xu, Z H; Higginson-Clarke, David; Rojas, Ana María Riverón; Le, Weidong; Rodríguez-Tanty, Chryslaine

    2008-03-30

    The sequencing procedure has been used to determine the size of the CAG repeat expansion for the diagnosis of genetic disorders. Likewise, standard polymerase chain reaction (PCR) and gel electrophoresis techniques are applied for screening large number of patients. The trinucleotide repeats (TNR) region amplification by means of the PCR procedure was initially performed using 32-P end-labelled primers and currently carried out with fluorescently end-labelled primers. The goal to obtain reliable TNR quantification assays, at low cost and short assay times, represents a challenge for the molecular diagnosis aimed at massive screening of affected populations. In the current work, we obtained preliminary results of a new methodology for the detection and size estimation of CAG expanded alleles. The assay was based on an indirect enzyme linked immunosorbent assay (ELISA) for quantifying the amount of labelled cytidines in DNA molecules. The label, 6-(p-bromobenzamido)caproyl radical, was introduced by the transamination and acylation reactions. A group of model sequences containing different numbers of CAG repeats, as well as the ATXN3 (ataxin 3) gene (from subjects suffering type 3 spinocerebellar ataxia SCA3) were used for assay standardization. The assay is simple, inexpensive, and easy to perform and differentiates distinct degrees of CAG expansions.

  5. Intergenerational Instability of the CAG Repeat of the Gene for Machado-Joseph Disease (MJD1) is Affected by the Genotype of the Normal Chromosome

    OpenAIRE

    五十嵐, 修一; Igarashi, Shuichi

    1997-01-01

    Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder caused by unstable expansion of a CAG repeat in the MJD1 gene at 14q32.1. To identify elements affecting the intergenerational instability of the CAG repeat, we investigated whether the CGG/GGG polymorphism at the 3' end of the CAG repeat affects the intergenerational instability of the CAG repeat. The [expanded (CAG) n-CGG]/[normal (CAG) n-GGG] haplotypes were found to result in significantly greater instability...

  6. The number of CAG repeats within the normal allele does not influence the age of onset in Huntington's disease.

    Science.gov (United States)

    Klempíř, Jiří; Zidovská, Jana; Stochl, Jan; Ing, Věra Kebrdlová; Uhrová, Tereza; Roth, Jan

    2011-01-01

    Huntington's disease (HD) is caused by the expansion of the number of CAG repeats on the chromosome 4p16.3, which results in elongated glutamine tract of huntingtin. The purpose of this work was to examine the interaction between the normal and mutant alleles of this gene and their effect on the clinical onset of HD. We hypothesized that in patients with identical number of CAG repeats within the mutant allele, the age of onset of HD is influenced by the number of CAG repeats within the normal allele. We analyzed the relations between the number of CAG repeats within the normal and mutant alleles, the age at HD onset, and the character of initial symptoms in 468 patients with clinically expressed HD. Although the Cox regression coefficient of 0.15 was significant (P CAG repeats within normal allele. Within the groups of patients with the same number of CAG repeats of the mutant allele, number of CAG repeats of the normal allele was found uncorrelated to the age at onset. Furthermore, when analyzing subgroups of patients with the same allelic composition on both alleles, we failed to observe any correlation with the age at the onset. Our analysis gives no corroboration to the idea of a normal allele having a share in the modification of the age at HD onset. We believe that with the current state of knowledge it is not possible to devise a mathematical model for HD onset prediction because too many entirely unknown modifying factors are still involved.

  7. Population genetics and new insight into range of CAG repeats of spinocerebellar ataxia type 3 in the Han Chinese population.

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    Shi-Rui Gan

    Full Text Available Spinocerebellar ataxia type 3 (SCA3, also called Machado-Joseph disease (MJD, is one of the most common SCAs worldwide and caused by a CAG repeat expansion located in ATXN3 gene. Based on the CAG repeat numbers, alleles of ATXN3 can be divided into normal alleles (ANs, intermediate alleles (AIs and expanded alleles (AEs. It was controversial whether the frequency of large normal alleles (large ANs is related to the prevalence of SCA3 or not. And there were huge chaos in the comprehension of the specific numbers of the range of CAG repeats which is fundamental for genetic analysis of SCA3. To illustrate these issues, we made a novel CAG repeat ladder to detect CAG repeats of ATXN3 in 1003 unrelated Chinese normal individuals and studied haplotypes defined by three single nucleotide polymorphisms (SNPs closed to ATXN3. We found that the number of CAG repeats ranged from 13 to 49, among them, 14 was the most common number. Positive skew, the highest frequency of large ANs and 4 AIs which had never been reported before were found. Also, AEs and large ANs shared the same haplotypes defined by the SNPs. Based on these data and other related studies, we presumed that de novo mutations of ATXN3 emerging from large ANs are at least one survival mechanisms of mutational ATXN3 and we can redefine the range of CAG repeats as: ANs≤44, 45 ≤AIs ≤49 and AEs≥50.

  8. Population genetics and new insight into range of CAG repeats of spinocerebellar ataxia type 3 in the Han Chinese population.

    Science.gov (United States)

    Gan, Shi-Rui; Ni, Wang; Dong, Yi; Wang, Ning; Wu, Zhi-Ying

    2015-01-01

    Spinocerebellar ataxia type 3 (SCA3), also called Machado-Joseph disease (MJD), is one of the most common SCAs worldwide and caused by a CAG repeat expansion located in ATXN3 gene. Based on the CAG repeat numbers, alleles of ATXN3 can be divided into normal alleles (ANs), intermediate alleles (AIs) and expanded alleles (AEs). It was controversial whether the frequency of large normal alleles (large ANs) is related to the prevalence of SCA3 or not. And there were huge chaos in the comprehension of the specific numbers of the range of CAG repeats which is fundamental for genetic analysis of SCA3. To illustrate these issues, we made a novel CAG repeat ladder to detect CAG repeats of ATXN3 in 1003 unrelated Chinese normal individuals and studied haplotypes defined by three single nucleotide polymorphisms (SNPs) closed to ATXN3. We found that the number of CAG repeats ranged from 13 to 49, among them, 14 was the most common number. Positive skew, the highest frequency of large ANs and 4 AIs which had never been reported before were found. Also, AEs and large ANs shared the same haplotypes defined by the SNPs. Based on these data and other related studies, we presumed that de novo mutations of ATXN3 emerging from large ANs are at least one survival mechanisms of mutational ATXN3 and we can redefine the range of CAG repeats as: ANs≤44, 45 ≤AIs ≤49 and AEs≥50.

  9. Continuous and periodic expansion of CAG repeats in Huntington's disease R6/1 mice.

    Science.gov (United States)

    Møllersen, Linda; Rowe, Alexander D; Larsen, Elisabeth; Rognes, Torbjørn; Klungland, Arne

    2010-12-09

    Huntington's disease (HD) is one of several neurodegenerative disorders caused by expansion of CAG repeats in a coding gene. Somatic CAG expansion rates in HD vary between organs, and the greatest instability is observed in the brain, correlating with neuropathology. The fundamental mechanisms of somatic CAG repeat instability are poorly understood, but locally formed secondary DNA structures generated during replication and/or repair are believed to underlie triplet repeat expansion. Recent studies in HD mice have demonstrated that mismatch repair (MMR) and base excision repair (BER) proteins are expansion inducing components in brain tissues. This study was designed to simultaneously investigate the rates and modes of expansion in different tissues of HD R6/1 mice in order to further understand the expansion mechanisms in vivo. We demonstrate continuous small expansions in most somatic tissues (exemplified by tail), which bear the signature of many short, probably single-repeat expansions and contractions occurring over time. In contrast, striatum and cortex display a dramatic--and apparently irreversible--periodic expansion. Expansion profiles displaying this kind of periodicity in the expansion process have not previously been reported. These in vivo findings imply that mechanistically distinct expansion processes occur in different tissues.

  10. Continuous and periodic expansion of CAG repeats in Huntington's disease R6/1 mice.

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    Linda Møllersen

    Full Text Available Huntington's disease (HD is one of several neurodegenerative disorders caused by expansion of CAG repeats in a coding gene. Somatic CAG expansion rates in HD vary between organs, and the greatest instability is observed in the brain, correlating with neuropathology. The fundamental mechanisms of somatic CAG repeat instability are poorly understood, but locally formed secondary DNA structures generated during replication and/or repair are believed to underlie triplet repeat expansion. Recent studies in HD mice have demonstrated that mismatch repair (MMR and base excision repair (BER proteins are expansion inducing components in brain tissues. This study was designed to simultaneously investigate the rates and modes of expansion in different tissues of HD R6/1 mice in order to further understand the expansion mechanisms in vivo. We demonstrate continuous small expansions in most somatic tissues (exemplified by tail, which bear the signature of many short, probably single-repeat expansions and contractions occurring over time. In contrast, striatum and cortex display a dramatic--and apparently irreversible--periodic expansion. Expansion profiles displaying this kind of periodicity in the expansion process have not previously been reported. These in vivo findings imply that mechanistically distinct expansion processes occur in different tissues.

  11. Progress study on the mechanism of CAG repeats dynamic mutation in polyQ disease

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    WANG Chun-rong

    2012-06-01

    Full Text Available Polyglutamine (polyQ disease is a group of neurodegenerative disorders caused by abnormal expansion of CAG repeats within coding regions of certain causative genes, which are translated into a series of abnormally expanded polyQ tracts causing cytotoxicity. So far, nine diseases caused by expanded polyQ tracts have been demonstrated including Huntington's disease (HD, spinobulbar muscular atrophy (SBMA, dentatorubral-pallidoluysian atrophy (DRPLA and several spinocerebellar ataxias subtypes (SCA. In human, long CAG repeats tend to expand during transmissions from parent to offspring, named as dynamic mutation, leading to an earlier age of disease onset and more severe symptoms in subsequent generations. The review presents some novel mechanisms based on dynamic mutation.

  12. [Somatic mosaicism of expanded CAG trinucleotide repeat in spinal and bulbar muscular atrophy (SBMA)].

    Science.gov (United States)

    Tanaka, F; Ito, Y; Sobue, G

    1999-04-01

    The CAG repeat in spinal and bulbar muscular atrophy (SBMA) is relatively stable in mitotic and meiotic processes as compared with other CAG repeat diseases. Previous reports indicate that SBMA does not manifest somatic mosaicism. However, detailed analysis in various tissues from 20 SBMA including 4 autopsied patients revealed the presence of the tissue-specific pattern of mosaicism. The prominent somatic mosaicism was observed in the cardiac and skeletal muscles, which are predominantly composed of postmitotic cells, and in the skin, prostate, and testis. The central nervous system (CNS) tissues, liver, and spleen showed smallest mosaicism. Such tissue-specific pattern of somatic mosaicism in SBMA is not explained by cell composition with different cell turnover rates. Other cell specific factors are likely more important for the somatic mosaicism in SBMA.

  13. Novel BAC mouse model of Huntington’s disease with 225 CAG repeats exhibits an early widespread and stable degenerative phenotype

    Science.gov (United States)

    Wegrzynowicz, Michal; Bichell, Terry Jo; Soares, Barbara D.; Loth, Meredith K.; McGlothan, Jennifer L.; Alikhan, Fatima S.; Hua, Kegang; Coughlin, Jennifer M.; Holt, Hunter K.; Jetter, Christopher S.; Mori, Susumu; Pomper, Martin G.; Osmand, Alexander P.; Guilarte, Tomás R.; Bowman, Aaron B.

    2015-01-01

    BACKGROUND Unusually large CAG repeat expansions (>60) in exon one of Huntingtin (HTT) are invariably associated with a juvenile-onset form of Huntington’s disease (HD), characterized by a more extensive and rapidly progressing neuropathology than the more prevalent adult-onset form. However, existing mouse models of HD that express the full-length Htt gene with CAG repeat lengths associated with juvenile HD (ranging between ~75 to ~150 repeats in published models) exhibit selective neurodegenerative phenotypes more consistent with adult-onset HD. OBJECTIVE To determine if a very large CAG repeat (>200) in full-length Htt elicits neurodegenerative phenotypes consistent with juvenile HD. METHODS Using a bacterial artificial chromosome (BAC) system, we generated mice expressing full-length mouse Htt with ~225 CAG repeats under control of the mouse Htt promoter. Mice were characterized using behavioral, neuropathological, biochemical and brain imaging methods. RESULTS BAC-225Q mice exhibit phenotypes consistent with a subset of features seen in juvenile-onset HD: very early motor behavior abnormalities, reduced body weight, widespread and progressive increase in Htt aggregates, gliosis, and neurodegeneration. Early striatal pathology was observed, including reactive gliosis and loss of dopamine receptors, prior to detectable volume loss. HD-related blood markers of impaired energy metabolism and systemic inflammation were also increased. Aside from an age-dependent progression of diffuse nuclear aggregates at 6 months of age to abundant neuropil aggregates at 12 months of age, other pathological and motor phenotypes showed little to no progression. CONCLUSIONS The HD phenotypes present in animals 3 to 12 months of age make the BAC-225Q mice a unique and stable model of full-length mutant Htt associated phenotypes, including body weight loss, behavioral impairment and HD-like neurodegenerative phenotypes characteristic of juvenile-onset HD and/or late-stage adult

  14. Chromatin structure of repeating CTG/CAG and CGG/CCG sequences in human disease.

    Science.gov (United States)

    Wang, Yuh-Hwa

    2007-05-01

    In eukaryotic cells, chromatin structure organizes genomic DNA in a dynamic fashion, and results in regulation of many DNA metabolic processes. The CTG/CAG and CGG/CCG repeating sequences involved in several neuromuscular degenerative diseases display differential abilities for the binding of histone octamers. The effect of the repeating DNA on nucleosome assembly could be amplified as the number of repeats increases. Also, CpG methylation, and sequence interruptions within the triplet repeats exert an impact on the formation of nucleosomes along these repeating DNAs. The two most common triplet expansion human diseases, myotonic dystrophy 1 and fragile X syndrome, are caused by the expanded CTG/CAG and CGG/CCG repeats, respectively. In addition to the expanded repeats and CpG methylation, histone modifications, chromatin remodeling factors, and noncoding RNA have been shown to coordinate the chromatin structure at both myotonic dystrophy 1 and fragile X loci. Alterations in chromatin structure at these two loci can affect transcription of these disease-causing genes, leading to disease symptoms. These observations have brought a new appreciation that a full understanding of disease gene expression requires a knowledge of the structure of the chromatin domain within which the gene resides.

  15. The CAG repeat polymorphism of mitochondrial polymerase gamma (POLG) is associated with male infertility in Tunisia.

    Science.gov (United States)

    Baklouti-Gargouri, S; Ghorbel, M; Chakroun, N; Sellami, A; Fakhfakh, F; Ammar-Keskes, L

    2012-05-01

    Male fertility largely depends on sperm quality, which may be affected by environmental and genetic factors. Recent data emphasised the implication of the polymorphism of mitochondrial DNA polymerase gamma (POLG) CAG repeats in male infertility. In this report, we explored a possible role of the (POLG) gene polymorphism in male infertility in Tunisian men. The polymorphic CAG repeat in the nuclear POLG gene was studied in 339 male subjects (216 patients with infertility (69 azoospermic, 115 oligoasthenoteratospermic and 32 normospermic) and 123 fertile) after DNA amplification by PCR, followed by genotyping using an automatic sequencer. The heterozygous and the homozygous mutant genotypes (10/ ≠ 10 and ≠ 10/ ≠ 10) were significantly more frequent among infertile patients than among fertile controls (11.2% versus 1.6%, P = 1.3 × 10(-3) and 4.6% versus 0.8%, P = 4.2 × 10(-7) respectively). We also found a significant difference between the frequencies of 10/ ≠ 10 genotype in azoospermic (4.4%) and in oligoasthenoteratospermic (15.6%) infertile patients (P = 2.6 × 10(-2) ). However, the homozygous mutant genotype (≠ 10/ ≠ 10) was seen at similar frequencies in azoospermic, normospermic and oligoasthenospermic men (4.4%, 3.1% and 5.2% respectively). Under our conditions, the findings showed an association between POLG CAG repeat polymorphism and male infertility in Tunisian population.

  16. Expanded CAG repeats in the murine Huntington's disease gene increases neuronal differentiation of embryonic and neural stem cells.

    Science.gov (United States)

    Lorincz, Matthew T; Zawistowski, Virginia A

    2009-01-01

    Huntington's disease is an uncommon autosomal dominant neurodegenerative disorder caused by expanded polyglutamine repeats. Increased neurogenesis was demonstrated recently in Huntington's disease post-mortem samples. In this manuscript, neuronally differentiated embryonic stem cells with expanded CAG repeats in the murine Huntington's disease homologue and neural progenitors isolated from the subventricular zone of an accurate mouse Huntington's disease were examined for increased neurogenesis. Embryonic stem cells with expanded CAG repeats in the murine Huntington's disease homologue were demonstrated to undergo facilitated differentiation first into neural progenitors, then into more mature neurons. Neural progenitor cells isolated from the subventricular zone of a Huntington's disease knock-in animal displayed increased production of neural progenitors and increased neurogenesis. These findings suggested that neuronally differentiating embryonic stem cells with expanded CAG repeats is a reasonable system to identify factors responsible for increased neurogenesis in Huntington's disease. Expression profiling analysis comparing neuronally differentiating embryonic stem cells with expanded CAG repeats to neuronally differentiating embryonic stem cells without expanded CAG repeats identified transcripts involved in development and transcriptional regulation as factors possibly mediating increased neurogenesis in response to expanded CAG repeats.

  17. Replication Stalling and Heteroduplex Formation within CAG/CTG Trinucleotide Repeats by Mismatch Repair

    KAUST Repository

    Viterbo, David

    2016-03-16

    Trinucleotide repeat expansions are responsible for at least two dozen neurological disorders. Mechanisms leading to these large expansions of repeated DNA are still poorly understood. It was proposed that transient stalling of the replication fork by the repeat tract might trigger slippage of the newly-synthesized strand over its template, leading to expansions or contractions of the triplet repeat. However, such mechanism was never formally proven. Here we show that replication fork pausing and CAG/CTG trinucleotide repeat instability are not linked, stable and unstable repeats exhibiting the same propensity to stall replication forks when integrated in a yeast natural chromosome. We found that replication fork stalling was dependent on the integrity of the mismatch-repair system, especially the Msh2p-Msh6p complex, suggesting that direct interaction of MMR proteins with secondary structures formed by trinucleotide repeats in vivo, triggers replication fork pauses. We also show by chromatin immunoprecipitation that Msh2p is enriched at trinucleotide repeat tracts, in both stable and unstable orientations, this enrichment being dependent on MSH3 and MSH6. Finally, we show that overexpressing MSH2 favors the formation of heteroduplex regions, leading to an increase in contractions and expansions of CAG/CTG repeat tracts during replication, these heteroduplexes being dependent on both MSH3 and MSH6. These heteroduplex regions were not detected when a mutant msh2-E768A gene in which the ATPase domain was mutated was overexpressed. Our results unravel two new roles for mismatch-repair proteins: stabilization of heteroduplex regions and transient blocking of replication forks passing through such repeats. Both roles may involve direct interactions between MMR proteins and secondary structures formed by trinucleotide repeat tracts, although indirect interactions may not be formally excluded.

  18. Genetic background modifies nuclear mutant huntingtin accumulation and HD CAG repeat instability in Huntington's disease knock-in mice.

    Science.gov (United States)

    Lloret, Alejandro; Dragileva, Ella; Teed, Allison; Espinola, Janice; Fossale, Elisa; Gillis, Tammy; Lopez, Edith; Myers, Richard H; MacDonald, Marcy E; Wheeler, Vanessa C

    2006-06-15

    Genetically precise models of Huntington's disease (HD), Hdh CAG knock-in mice, are powerful systems in which phenotypes associated with expanded HD CAG repeats are studied. To dissect the genetic pathways that underlie such phenotypes, we have generated Hdh(Q111) knock-in mouse lines that are congenic for C57BL/6, FVB/N and 129Sv inbred genetic backgrounds and investigated four Hdh(Q111) phenotypes in these three genetic backgrounds: the intergenerational instability of the HD CAG repeat and the striatal-specific somatic HD CAG repeat expansion, nuclear mutant huntingtin accumulation and intranuclear inclusion formation. Our results reveal increased intergenerational and somatic instability of the HD CAG repeat in C57BL/6 and FVB/N backgrounds compared with the 129Sv background. The accumulation of nuclear mutant huntingtin and the formation of intranuclear inclusions were fastest in the C57BL/6 background, slowest in the 129Sv background and intermediate in the FVB/N background. Inbred strain-specific differences were independent of constitutive HD CAG repeat size and did not correlate with Hdh mRNA levels. These data provide evidence for genetic modifiers of both intergenerational HD CAG repeat instability and striatal-specific phenotypes. Different relative contributions of C57BL/6 and 129Sv genetic backgrounds to the onset of nuclear mutant huntingtin and somatic HD CAG repeat expansion predict that the initiation of each of these two phenotypes is modified by different genes. Our findings set the stage for defining disease-related genetic pathways that will ultimately provide insight into disease mechanism.

  19. Critical nucleus size for disease-related polyglutamine aggregation is repeat length dependent

    OpenAIRE

    Kar, Karunakar; Jayaraman, Murali; Sahoo, Bankanidhi; Kodali, Ravindra; Wetzel, Ronald

    2011-01-01

    Since polyglutamine (polyQ) aggregate formation has been implicated as playing an important role in expanded CAG repeat diseases, it is important to understand the biophysics underlying the initiation of aggregation. Previously we showed that relatively long polyQ peptides aggregate by nucleated growth polymerization and a monomeric critical nucleus. We show here that, over a short repeat length range from Q26 to Q23, the size of the critical nucleus for aggregation increases from monomeric t...

  20. Transcription-induced CAG repeat contraction in human cells is mediated in part by transcription-coupled nucleotide excision repair.

    Science.gov (United States)

    Lin, Yunfu; Wilson, John H

    2007-09-01

    Expansions of CAG repeat tracts in the germ line underlie several neurological diseases. In human patients and mouse models, CAG repeat tracts display an ongoing instability in neurons, which may exacerbate disease symptoms. It is unclear how repeats are destabilized in nondividing cells, but it cannot involve DNA replication. We showed previously that transcription through CAG repeats induces their instability (Y. Lin, V. Dion, and J. H. Wilson, Nat. Struct. Mol. Biol. 13:179-180). Here, we present a genetic analysis of the link between transcription-induced repeat instability and nucleotide excision repair (NER) in human cells. We show that short interfering RNA-mediated knockdown of CSB, a component specifically required for transcription-coupled NER (TC-NER), and knockdowns of ERCC1 and XPG, which incise DNA adjacent to damage, stabilize CAG repeat tracts. These results suggest that TC-NER is involved in the pathway for transcription-induced CAG repeat instability. In contrast, knockdowns of OGG1 and APEX1, key components involved in base excision repair, did not affect repeat instability. In addition, repeats are stabilized by knockdown of transcription factor IIS, consistent with a requirement for RNA polymerase II (RNAPII) to backtrack from a transcription block. Repeats also are stabilized by knockdown of either BRCA1 or BARD1, which together function as an E3 ligase that can ubiquitinate arrested RNAPII. Treatment with the proteasome inhibitor MG132, which stabilizes repeats, confirms proteasome involvement. We integrate these observations into a tentative pathway for transcription-induced CAG repeat instability that can account for the contractions observed here and potentially for the contractions and expansions seen with human diseases.

  1. MSH2 ATPase domain mutation affects CTG*CAG repeat instability in transgenic mice.

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    Stéphanie Tomé

    2009-05-01

    Full Text Available Myotonic dystrophy type 1 (DM1 is associated with one of the most highly unstable CTG*CAG repeat expansions. The formation of further repeat expansions in transgenic mice carrying expanded CTG*CAG tracts requires the mismatch repair (MMR proteins MSH2 and MSH3, forming the MutSbeta complex. It has been proposed that binding of MutSbeta to CAG hairpins blocks its ATPase activity compromising hairpin repair, thereby causing expansions. This would suggest that binding, but not ATP hydrolysis, by MutSbeta is critical for trinucleotide expansions. However, it is unknown if the MSH2 ATPase activity is dispensible for instability. To get insight into the mechanism by which MSH2 generates trinucleotide expansions, we crossed DM1 transgenic mice carrying a highly unstable >(CTG(300 repeat tract with mice carrying the G674A mutation in the MSH2 ATPase domain. This mutation impairs MSH2 ATPase activity and ablates base-base MMR, but does not affect the ability of MSH2 (associated with MSH6 to bind DNA mismatches. We found that the ATPase domain mutation of MSH2 strongly affects the formation of CTG expansions and leads instead to transmitted contractions, similar to a Msh2-null or Msh3-null deficiency. While a decrease in MSH2 protein level was observed in tissues from Msh2(G674 mice, the dramatic reduction of expansions suggests that the expansion-biased trinucleotide repeat instability requires a functional MSH2 ATPase domain and probably a functional MMR system.

  2. No CAG repeat expansion of polymerase gamma is associated with male infertility in Tamil Nadu, South India

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    J Poongothai

    2013-01-01

    Full Text Available Mitochondria contains a single deoxyribonucleic acid (DNA polymerase, polymerase gamma (POLG mapped to long arm of chromosome 15 (15q25, responsible for replication and repair of mitochondrial DNA. Exon 1 of the human POLG contains CAG trinucleotide repeat, which codes for polyglutamate. Ten copies of CAG repeat were found to be uniformly high (0.88 in different ethnic groups and considered as the common allele, whereas the mutant alleles (not -10/not -10 CAG repeats were found to be associated with oligospermia/oligoasthenospermia in male infertility. Recent data suggested the implication of POLG CAG repeat expansion in infertility, but are debated. The aim of our study was to explore whether the not -10/not -10 variant is associated with spermato g enic failure. As few study on Indian population have been conducted so far to support this view, we investigated the distribution of the POLG CAG repeats in 61 infertile men and 60 normozoospermic control Indian men of Tamil Nadu, from the same ethnic background. This analysis interestingly revealed that the homozygous wild type genotype (10/-10 was common in infertile men (77% - 47/61 and in normozoospermic control men (71.7% - 43/60. Our study failed to confirm any influence of the POLG gene polymorphism on the efficiency of the spermatogenesis.

  3. No CAG repeat expansion of polymerase gamma is associated with male infertility in Tamil Nadu, South India.

    Science.gov (United States)

    Poongothai, J

    2013-07-01

    Mitochondria contains a single deoxyribonucleic acid (DNA) polymerase, polymerase gamma (POLG) mapped to long arm of chromosome 15 (15q25), responsible for replication and repair of mitochondrial DNA. Exon 1 of the human POLG contains CAG trinucleotide repeat, which codes for polyglutamate. Ten copies of CAG repeat were found to be uniformly high (0.88) in different ethnic groups and considered as the common allele, whereas the mutant alleles (not -10/not -10 CAG repeats) were found to be associated with oligospermia/oligoasthenospermia in male infertility. Recent data suggested the implication of POLG CAG repeat expansion in infertility, but are debated. The aim of our study was to explore whether the not -10/not -10 variant is associated with spermatogenic failure. As few study on Indian population have been conducted so far to support this view, we investigated the distribution of the POLG CAG repeats in 61 infertile men and 60 normozoospermic control Indian men of Tamil Nadu, from the same ethnic background. This analysis interestingly revealed that the homozygous wild type genotype (10/-10) was common in infertile men (77% - 47/61) and in normozoospermic control men (71.7% - 43/60). Our study failed to confirm any influence of the POLG gene polymorphism on the efficiency of the spermatogenesis.

  4. Somatic CTG•CAG repeat instability in a mouse model for myotonic dystrophy type 1 is associated with changes in cell nuclearity and DNA ploidy

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    Wieringa Bé

    2007-07-01

    Full Text Available Abstract Background Trinucleotide instability is a hallmark of degenerative neurological diseases like Huntington's disease, some forms of spinocerebellar ataxia and myotonic dystrophy type 1 (DM1. To investigate the effect of cell type and cell state on the behavior of the DM1 CTG•CAG repeat, we studied a knock-in mouse model for DM1 at different time points during ageing and followed how repeat fate in cells from liver and pancreas is associated with polyploidization and changes in nuclearity after the onset of terminal differentiation. Results After separation of liver hepatocytes and pancreatic acinar cells in pools with 2n, 4n or 8n DNA, we analyzed CTG•CAG repeat length variation by resolving PCR products on an automated PAGE system. We observed that somatic CTG•CAG repeat expansion in our DM1 mouse model occurred almost uniquely in the fraction of cells with high cell nuclearity and DNA ploidy and aggravated with aging. Conclusion Our findings suggest that post-replicative and terminal-differentiation events, coupled to changes in cellular DNA content, form a preconditional state that influences the control of DNA repair or recombination events involved in trinucleotide expansion in liver hepatocytes and pancreatic acinar cells.

  5. Expanded CAG/CTG repeat DNA induces a checkpoint response that impacts cell proliferation in Saccharomyces cerevisiae.

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    Rangapriya Sundararajan

    2011-03-01

    Full Text Available Repetitive DNA elements are mutational hotspots in the genome, and their instability is linked to various neurological disorders and cancers. Although it is known that expanded trinucleotide repeats can interfere with DNA replication and repair, the cellular response to these events has not been characterized. Here, we demonstrate that an expanded CAG/CTG repeat elicits a DNA damage checkpoint response in budding yeast. Using microcolony and single cell pedigree analysis, we found that cells carrying an expanded CAG repeat frequently experience protracted cell division cycles, persistent arrests, and morphological abnormalities. These phenotypes were further exacerbated by mutations in DSB repair pathways, including homologous recombination and end joining, implicating a DNA damage response. Cell cycle analysis confirmed repeat-dependent S phase delays and G2/M arrests. Furthermore, we demonstrate that the above phenotypes are due to the activation of the DNA damage checkpoint, since expanded CAG repeats induced the phosphorylation of the Rad53 checkpoint kinase in a rad52Δ recombination deficient mutant. Interestingly, cells mutated for the MRX complex (Mre11-Rad50-Xrs2, a central component of DSB repair which is required to repair breaks at CAG repeats, failed to elicit repeat-specific arrests, morphological defects, or Rad53 phosphorylation. We therefore conclude that damage at expanded CAG/CTG repeats is likely sensed by the MRX complex, leading to a checkpoint response. Finally, we show that repeat expansions preferentially occur in cells experiencing growth delays. Activation of DNA damage checkpoints in repeat-containing cells could contribute to the tissue degeneration observed in trinucleotide repeat expansion diseases.

  6. Expanded CAG/CTG repeat DNA induces a checkpoint response that impacts cell proliferation in Saccharomyces cerevisiae.

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    Sundararajan, Rangapriya; Freudenreich, Catherine H

    2011-03-01

    Repetitive DNA elements are mutational hotspots in the genome, and their instability is linked to various neurological disorders and cancers. Although it is known that expanded trinucleotide repeats can interfere with DNA replication and repair, the cellular response to these events has not been characterized. Here, we demonstrate that an expanded CAG/CTG repeat elicits a DNA damage checkpoint response in budding yeast. Using microcolony and single cell pedigree analysis, we found that cells carrying an expanded CAG repeat frequently experience protracted cell division cycles, persistent arrests, and morphological abnormalities. These phenotypes were further exacerbated by mutations in DSB repair pathways, including homologous recombination and end joining, implicating a DNA damage response. Cell cycle analysis confirmed repeat-dependent S phase delays and G2/M arrests. Furthermore, we demonstrate that the above phenotypes are due to the activation of the DNA damage checkpoint, since expanded CAG repeats induced the phosphorylation of the Rad53 checkpoint kinase in a rad52Δ recombination deficient mutant. Interestingly, cells mutated for the MRX complex (Mre11-Rad50-Xrs2), a central component of DSB repair which is required to repair breaks at CAG repeats, failed to elicit repeat-specific arrests, morphological defects, or Rad53 phosphorylation. We therefore conclude that damage at expanded CAG/CTG repeats is likely sensed by the MRX complex, leading to a checkpoint response. Finally, we show that repeat expansions preferentially occur in cells experiencing growth delays. Activation of DNA damage checkpoints in repeat-containing cells could contribute to the tissue degeneration observed in trinucleotide repeat expansion diseases.

  7. Cytogenetic and molecular analysis of infertile Chinese men: karyotypic abnormalities, Y-chromosome microdeletions, and CAG and GGN repeat polymorphisms in the androgen receptor gene.

    Science.gov (United States)

    Han, T T; Ran, J; Ding, X P; Li, L J; Zhang, L Y; Zhang, Y P; Nie, S S; Chen, L

    2013-07-08

    Chromosome abnormalities, Y-chromosome microdeletions, and androgen receptor gene CAG and GGN repeat polymorphisms in infertile Chinese men featuring severe oligospermia and azoospermia were analyzed. Ninety-six fertile men and 189 non-obstructive infertile men, including 125 patients with azoospermia and 64 with severe oligozoospermia, were studied. Seventeen infertile men (9.0%) carried a chromosome abnormality. Twenty (10.6%) carried a Y-chromosome microdeletion. In the remainder of the patients and controls, GGN and CAG repeats were sequenced. Short GGN repeats (n repeats strongly correlated with sperm counts. No significant difference in CAG repeats was found between patients and controls, nor were CAG repeats correlated with sperm counts. However, for CAG repeats ranging between 24 and 25, there was a >2.5-fold risk (OR = 2.539, 95%CI = 1.206-5.344, P repeats in Chinese male infertility.

  8. Androgen receptor gene CAG repeat polymorphism and risk of isolated hypospadias: results from a meta-analysis.

    Science.gov (United States)

    Huang, G; Shan, W; Zeng, L; Huang, L

    2015-03-06

    Studies investigating the association between the CAG repeat polymorphism and the risk of isolated hypospadias have reported conflicting results. The aim of this study was to quantitatively summarize the evidence for such a relationship. Two investigators independently searched the Medline, Embase, CNKI, and Wanfang databases. Weighted mean difference and 95% confidence intervals for the CAG repeat polymorphism and isolated hypospadias were calculated using a random-effects model. Subgroup analyses were performed by race, study design, sample for DNA extraction, and hypospadias classifications. This meta-analysis included 6 case-control studies, including 444 isolated hypospadias cases and 727 controls. The results showed that patients with isolated hypospadias had longer CAG repeats in their androgen receptor gene sequence (weighted mean difference = 1.36, 95% confidence interval = 0.60-2.13; P = 0.0005). Similarly, stratified analyses also detected significant associations in all subgroups, excluding the group with severe hypospadias (weighted mean difference = 0.35, 95% confidence interval = -0.42-1.12; P = 0.38). This meta-analysis indicated that longer CAG repeats were associated with the risk of isolated hypospadias, and that longer CAG polymorphisms may be related to the etiology of isolated hypospadias. Future studies based on Asian and African-American patients should be performed to re-evaluate this association.

  9. Huntington CAG repeat size does not modify onset age in familial Parkinson’s disease: The GenePD Study

    Science.gov (United States)

    McNicoll, Christopher F.; Latourelle, Jeanne C.; MacDonald, Marcy E.; Lew, Mark F.; Suchowersky, Oksana; Klein, Christine; Golbe, Lawrence I.; Mark, Margery H.; Growdon, John H.; Wooten, G. Frederick; Watts, Ray L.; Guttman, Mark; Racette, Brad A.; Perlmutter, Joel S.; Ahmed, Anwar; Shill, Holly A.; Singer, Carlos; Saint-Hilaire, Marie H.; Massood, Tiffany; Huskey, Karen W.; DeStefano, Anita L.; Gillis, Tammy; Mysore, Jayalakshmi; Goldwurm, Stefano; Pezzoli, Gianni; Baker, Kenneth B.; Itin, Ilia; Litvan, Irene; Nicholson, Garth; Corbett, Alastair; Nance, Martha; Drasby, Edward; Isaacson, Stuart; Burn, David J.; Chinnery, Patrick F.; Pramstaller, Peter P.; Al-hinti, Jomana; Moller, Anette T.; Ostergaard, Karen; Sherman, Scott J.; Roxburgh, Richard; Snow, Barry; Slevin, John T.; Cambi, Franca; Gusella, James F.; Myers, Richard H.

    2009-01-01

    The ATP/ADP ratio reflects mitochondrial function and has been reported to be influenced by the size of the Huntington disease gene (HD) repeat. Impaired mitochondrial function has long been implicated in the pathogenesis of Parkinson’s disease (PD) and therefore, we evaluated the relationship of the HD CAG repeat size to PD onset age in a large sample of familial PD cases. PD affected siblings (n=495) with known onset ages from 248 families, were genotyped for the HD CAG repeat. Genotyping failed in 11 cases leaving 484 for analysis, including 35 LRRK2 carriers. All cases had HD CAG repeats (range 15 to 34) below the clinical range for HD, although 5.2 percent of the sample (n=25) had repeats in the intermediate range (the intermediate range lower limit=27; upper limit=35 repeats), suggesting that the prevalence of intermediate allele carriers in the general population is significant. No relation between the HD CAG repeat size and the age at onset for PD was found in this sample of familial PD. PMID:18649400

  10. A study of 45,X/46,XX mosaicism in Turner syndrome females: a novel primer pair for the (CAG)n repeat within the androgen receptor gene.

    Science.gov (United States)

    Leonova, J; Hanson, C

    1999-01-01

    This paper describes the procedures developed for the determining of diparental/uniparental origin of X chromosomes in mosaic Turner females (karyotype 45,X/46,XX), and accounts for results of the analysis of chromosomal material from 20 girls with Turner syndrome. An (CAG)n repeat within the androgen receptor (AR) gene was selected as a genetic marker. A novel primer pair for amplification of the (CAG)12-30 repeat was designed. These primers gave an amplification product of 338 bp in length and were following (5'-->3'): agttagggctgggaagggtc and cggctgtgaaggttgctgt. Nineteen of the subjects were heterozygous for the selected marker. In 4 cases there were distinct signals from three alleles. The only Turner female in the study who had been previously ascribed a non-mosaic 45,X karyotype by using cytogenetic techniques, proved to be a cryptic mosaic, displaying two alleles of the genetic marker in the more sensitive molecular assay. These results suggest that in most cases 45,X/46,XX mosaicism in Turner females arises through loss of one of the X chromosomes in some cell lines in originally 46,XX conceptuses, rather than through mitotic non-disjunction during early embryogenesis in originally 45,X conceptuses. A high sensitivity of the modified assay based on PCR-amplification of the (CAG)n repeat within AR gene proves its usefulness as a tool for studying mosaicism in Turner syndrome.

  11. Preimplantation genetic diagnosis of spinocerebellar ataxia 3 by (CAG)(n) repeat detection.

    Science.gov (United States)

    Drüsedau, M; Dreesen, J C F M; De Die-Smulders, C; Hardy, K; Bras, M; Dumoulin, J C M; Evers, J L H; Smeets, H J M; Geraedts, J P M; Herbergs, J

    2004-01-01

    Spinocerebellar ataxia 3 (SCA3) is an autosomal dominant neurodegenerative disorder characterized by variable expression and a variable age of onset. SCA3/MJD (Machado-Joseph disease) is caused by an expansion of a (CAG)(n) repeat in the MJD1 gene on chromosome 14q32.1. A single cell PCR protocol has been developed for preimplantation genetic diagnosis (PGD) of SCA3 to select unaffected embryos on the basis of the CAG genotype. Single leukocytes and blastomeres served as a single cell amplification test system to determine the percentage of allelic drop-out (ADO) and PCR efficiency. Out of 105 tested heterozygous single leukocytes, 103 (98.1%) showed a positive amplification signal, while five cells (4.9%) showed ADO. Amplification in single blastomeres was obtained in 13 out of a total of 14, and ADO was observed in two out of the 13 single blastomeres. PGD of SCA3 was performed in a couple with paternal transmission of the SCA3 allele. Seven embryos were available for biopsy, all biopsied blastomeres showed amplification and no ADO occurred. One embryo was diagnosed as affected whereas six embryos were diagnosed as unaffected. Two unaffected embryos were transferred and resulted in a singleton pregnancy and the birth of a healthy girl.

  12. Triplet repeat mutation length gains correlate with cell-type specific vulnerability in Huntington disease brain.

    Science.gov (United States)

    Shelbourne, Peggy F; Keller-McGandy, Christine; Bi, Wenya Linda; Yoon, Song-Ro; Dubeau, Louis; Veitch, Nicola J; Vonsattel, Jean Paul; Wexler, Nancy S; Arnheim, Norman; Augood, Sarah J

    2007-05-15

    Huntington disease is caused by the expansion of a CAG repeat encoding an extended glutamine tract in a protein called huntingtin. Here, we provide evidence supporting the hypothesis that somatic increases of mutation length play a role in the progressive nature and cell-selective aspects of HD pathogenesis. Results from micro-dissected tissue and individual laser-dissected cells obtained from human HD cases and knock-in HD mice indicate that the CAG repeat is unstable in all cell types tested although neurons tend to have longer mutation length gains than glia. Mutation length gains occur early in the disease process and continue to accumulate as the disease progresses. In keeping with observed patterns of cell loss, neuronal mutation length gains tend to be more prominent in the striatum than in the cortex of low-grade human HD cases, less so in more advanced cases. Interestingly, neuronal sub-populations of HD mice appear to have different propensities for mutation length gains; in particular, smaller mutation length gains occur in nitric oxide synthase-positive striatal interneurons (a relatively spared cell type in HD) compared with the pan-striatal neuronal population. More generally, the data demonstrate that neuronal changes in HD repeat length can be at least as great, if not greater, than those observed in the germline. The fact that significant CAG repeat length gains occur in non-replicating cells also argues that processes such as inappropriate mismatch repair rather than DNA replication are involved in generating mutation instability in HD brain tissue.

  13. Androgen receptor CAG polymorphism and the risk of benign prostatic hyperplasia in a Brazilian population

    Directory of Open Access Journals (Sweden)

    Vanderlei Biolchi

    2012-06-01

    Full Text Available Benign prostatic hyperplasia (BPH is a very frequent age-related proliferative abnormality in men. Polymorphic CAG repeat in the androgen receptor (AR can alter transactivation of androgen-responsive genes and potentially influence BPH risk. We investigated the association between CAG repeat length and risk of BPH in a case-control study of a Brazilian population. We evaluated 214 patients; 126 with BPH and 88 healthy controls. DNA was extracted from peripheral leucocytes and the AR gene was analyzed using fragment analysis. Hazard ratio (HR and 95% confidence interval were estimated using logistic regression models. Mean CAG length was not different between patients with BPH and controls. The CAG repeat length was examined as a categorical variable (CAG 21 and CAG 22 and did not differ between the control vs. the BPH group. We found no evidence for an association between AR CAG repeat length in BPH risk in a population-based sample of Brazilians.

  14. Analysis of SCA1, DRPLA, MJD, SCA2, and SCA6 CAG repeats in 48 Portuguese ataxia families.

    Science.gov (United States)

    Silveira, I; Coutinho, P; Maciel, P; Gaspar, C; Hayes, S; Dias, A; Guimarães, J; Loureiro, L; Sequeiros, J; Rouleau, G A

    1998-03-28

    The spinocerebellar ataxias (SCAs) are clinically and genetically a heterogeneous group of neurodegenerative disorders. To date, eight different loci causing SCA have been identified: SCA1, SCA2, Machado-Joseph disease (MJD)/SCA3, SCA4, SCA5, SCA6, SCA7, and dentatorubropallidoluysian atrophy (DRPLA). Expansion of a CAG repeat in the disease genes has been found in five of these disorders. To estimate the relative frequencies of the SCA1, DRPLA, MJD, SCA2, and SCA6 mutations among Portuguese ataxia patients, we collected DNA samples from 48 ataxia families and performed polymerase chain reaction (PCR) amplification of the CAG repeat mutations on chromosomes 6p, 12p, 14q, 12q, and 19p, respectively. Fifty-five individuals belonging to 34 dominant families (74%) had an expanded CAG repeat at the MJD gene. In five individuals from two kindreds with a dominant pattern of inheritance (4%), an expanded CAG repeat at the SCA2 gene was found. In MJD patients, the normal allele size ranged from 13 to 41, whereas the mutant alleles contained 65 to 80 repeats. For the SCA2 patients, normal alleles had 22 or 23, while expanded alleles had between 36 and 47 CAG units. We did not find the SCA1, DRPLA, or SCA6 mutations in our group of families. The MJD mutation remains the most common cause of SCA in Portugal, while a small number of cases are caused by mutations at the SCA2 gene, and 22% are due to still unidentified genes.

  15. CAG-repeat variant in the polymerase γ gene and male infertility in the Chinese population: a meta-analysis%DNA聚合酶γ基CAG-三核苷酸多态性与中国人群男性不育的相关性研究及元分析

    Institute of Scientific and Technical Information of China (English)

    Shu-Yuan Liu; Xiao-Qin Huang; Hao Sun; Jia-You Chu; Chang-Jun Zhang; Hai-Ying Peng; Yu-Feng Yao; Lei Shi; Jin-Bao Chen; Ke-Qin Lin; Liang Yu; Li Shi

    2011-01-01

    Several studies have reported a relationship between the length of the CAG-repeat in the polymerase γ(POLG)gene and male infertility.However,other studies have not reproduced this result.In our study,the POLG-CAG-repeat length was analyzed in 535 healthy individuals from six Chinese Han populations living in different provinces.The frequencies of 10-CAG alleles and genotypes were high(97.38 and 94.13%,respectively),with no significant difference among the six Chinese Han populations.Furthermore,we determined the distribution of the POLG-CAG-repeat in 150 infertile men and 126 fertile men.Our study suggested that the distributions of POLG-CAG-repeat alleles and genotypes were not significantly different between infertile(95.67 and 92.67%,respectively)and fertile men(97.22 and 94.44%,respectively).In a subsequent meta-analysis,combining our data with data from previous studies,a comparison of the CAG-repeat alleles in fertile versus infertile men showed no obvious risk for male infertility associated with any particular allele(pooled odds ratio(OR)=0.94; 95% confidence interval(CI):0.60-1.48).The significance level was not attained with any of the following genetic models: homozygote comparison(not 10/not 10 versus 10/10:OR=1.34; 95% CI:0.66-2.72),heterozygote comparison(10/not 10 versus 10/10: OR=1.04; 95% CI:0.78-1.38),dominant model comparison(not 10/not 10+10/not 10 versus 10/10: OR=1.08; 95% CI: 0.79-1.47)and recessive genetic comparison(not 10/not 10 versus 10/not 10+10/10:OR=1.31; 95% CI:0.68-2.55).In conclusion,there is no significant difference of the frequencies of POLG-CAG.repeat variants among six Chinese Han populations,and this polymorphism may not be associated with Chinese male infertility.On the basis of a meta-analysis,there is no obvious association between CAG-repeat variants of the POLG gene and male infertility.

  16. Expanded CAG repeats in the murine Huntington’s disease gene increases neuronal differentiation of embryonic and neural stem cells

    OpenAIRE

    Lorincz, Matthew T.; Zawistowski, Virginia A.

    2008-01-01

    Huntington’s disease is an uncommon autosomal dominant neurodegenerative disorder caused by expanded polyglutamine repeats. Increased neurogenesis was demonstrated recently in Huntington’s disease postmortem samples. In this manuscript, neuronally differentiated embryonic stem cells with expanded CAG repeats in the murine Huntington’s disease homologue and neural progenitors isolated from the subventricular zone of an accurate mouse Huntington’s disease were examined for increased neurogenesi...

  17. Oligodeoxynucleotide binding to (CTG) · (CAG) microsatellite repeats inhibits replication fork stalling, hairpin formation, and genome instability.

    Science.gov (United States)

    Liu, Guoqi; Chen, Xiaomi; Leffak, Michael

    2013-02-01

    (CTG)(n) · (CAG)(n) trinucleotide repeat (TNR) expansion in the 3' untranslated region of the dystrophia myotonica protein kinase (DMPK) gene causes myotonic dystrophy type 1. However, a direct link between TNR instability, the formation of noncanonical (CTG)(n) · (CAG)(n) structures, and replication stress has not been demonstrated. In a human cell model, we found that (CTG)(45) · (CAG)(45) causes local replication fork stalling, DNA hairpin formation, and TNR instability. Oligodeoxynucleotides (ODNs) complementary to the (CTG)(45) · (CAG)(45) lagging-strand template eliminated DNA hairpin formation on leading- and lagging-strand templates and relieved fork stalling. Prolonged cell culture, emetine inhibition of lagging-strand synthesis, or slowing of DNA synthesis by low-dose aphidicolin induced (CTG)(45) · (CAG)(45) expansions and contractions. ODNs targeting the lagging-strand template blocked the time-dependent or emetine-induced instability but did not eliminate aphidicolin-induced instability. These results show directly that TNR replication stalling, replication stress, hairpin formation, and instability are mechanistically linked in vivo.

  18. No evidence that 2D:4D is related to the number of CAG repeats in the androgen receptor gene

    Directory of Open Access Journals (Sweden)

    Johannes eHönekopp

    2013-12-01

    Full Text Available The length ratio of the second to the fourth digit (2D:4D is a putative marker of prenatal testosterone (T effects. The number of CAG repeats (CAGn in the AR gene is negatively correlated with T sensitivity in vitro. Results regarding the relationship between 2D:4D and CAGn are mixed but have featured prominently in arguments for and against the validity of 2D:4D. Here, I present random-effects meta-analyses on 14 relevant samples with altogether 1,904 subjects. Results were homogeneous across studies. Even liberal estimates (upper limit of the 95% CI were close to zero and therefore suggested no substantial relationship of CAGn with either right-hand 2D:4D, left-hand 2D:4D, or the difference between the two. However, closer analysis of the effects of CAGn on T dependent gene activation in vitro and of relationships between CAGn and T dependent phenotypic characteristics suggest that normal variability of CAGn has mostly no, very small, or inconsistent effects. Therefore, the lack of a clear association between CAGn and 2D:4D has no negative implications for the latter’s validity as a marker of prenatal T effects.

  19. A unified rapid PCR method for detection of normal and expanded trinucleotide alleles of CAG repeats in huntington chorea and CGG repeats in fragile X syndrome.

    Science.gov (United States)

    Todorov, Tihomir; Todorova, Albena; Georgieva, Bilyana; Mitev, Vanyo

    2010-06-01

    We report on a unified rapid betaine-based-PCR protocol for amplification of the (CAG)n region in Huntington disease (HD) and the (CGG)n region in Fragile X syndrome (FXS), followed by an electrophoretic separation on automated sequencer for precise determination of the triplet numbers. The high betaine concentration (2.5 M betaine) permits precise amplification of the CAG and CGG repeats. Ten HD affected patients and 10 healthy individuals from HD families were re-evaluated. For FXS the CGG region in normal individuals and premutations of about 100 repeats were precisely amplified by this protocol. Ten unrelated FXS premutation carriers and 24 mentally retarded non-FXS affected boys were re-examined by this method. The results totally coincided with the previous ones. This protocol is a good choice as a fast screening test. Within 24 h we can have preliminary information on the patient's genetic status. Normal individuals, CGG premutation carriers up to 100 repeats, as well as HD patients carrying an expansion up to 50 CAG repeats can be easily clarified. This accounts for a relatively large proportion (about 90%) of the suspected HD and FXS patients, referred to our laboratory for genetic analysis. The calculation of the repeat's number is more accurate for the correct interpretation of the results, screening tests and genetic counselling.

  20. ANDROGEN RECEPTOR CAG AND GGN REPEAT POLYMORPHISMS AND BONE MASS IN BOYS AND GIRLS.

    Science.gov (United States)

    Rodríguez-Garcia, Lorena; Ponce-Gonzalez, Jesus G; González-Henriquez, Juan J; Rodriguez-Gonzalez, Francisco G; Díaz-Chico, Bonifacio N; Calbet, Jose A L; Serrano-Sanchez, José A; Dorado, Cecilia; Guadalupe-Grau, Amelia

    2015-12-01

    Introducción: el gen humano del receptor de androgenos (AR) posee dos repeticiones polimorficas de trinucleotidos (CAG y GGN) que afectan a la cantidad de proteina AR traducida. En este estudio, genotipamos esos tractos polimorficos en una muestra representativa de ninos caucasicos espanoles (Tanner ≤ 5), compuesta por 152 ninos (11.5 } 2.6 anos) y 116 ninas (10.1 } 3.2 anos) e investigamos su asociacion con la masa osea. Métodos: la longitud de las repeticiones CAG y GGN se determino mediante PCR y analisis de fragmentos. La composicion corporal se midio mediante absorciometria dual de rayos X (DXA). Los participantes fueron agrupados como CAG cortos (CAGS) si poseian una longitud de repeticiones ≤ 21 y CAG largos si esta era > 21. Ademas, los participantes se agruparon como GGN cortos (GGNS) si poseian una longitud de repeticiones ≤ 23 y GGN largos (GGNL) si esta era > 23. Resultados: en los ninos se encontraron diferencias en talla, peso corporal, densidad mineral osea (BMD) y contenido mineral oseo (BMC) del cuerpo entero, BMC de las extremidades superiores e inferiores, BMD del cuello del femur, BMC y BMD del triangulo de Ward’s y BMD de la espina lumbar entre los grupos CAGS y CAGL (P osea en las ninas. Conclusiones: nuestros resultados apoyan la hipotesis de que los alelos largos de los polimorfismos CAG y GGN del AR estan asociados con una mayor masa osea en ninos prepuberes.

  1. [Tissue variability of androgen receptor gene in bulbospinal muscular atrophy--comparison of the number of CAG repeats between muscles and peripheral blood leukocytes].

    Science.gov (United States)

    Nakajima, H; Kimura, F; Shinoda, K; Ohsawa, N; Nakagawa, T; Shimizu, A

    1993-10-01

    We investigated an expansion of CAG repeats in exon 1 of androgen receptor gene in skeletal muscle tissue obtained from the patients with various neuro-muscular disorders (5 BSMA, 33 patients with amyotrophic lateral sclerosis, 3 patients with spinal progressive muscular atrophy and 2 patients with hereditary motor sensory neuropathy), by polymerase chain reaction (PCR) amplification according to LaSpadas' description. These muscle tissues had been stored at -70 degrees C freezer during 7 years. We also studied the tissue variation of CAG repeats size between muscles and peripheral blood leukocytes in 4 patients with BSMA. And we confirmed the increased number of CAG repeats in all 5 BSMA except for other patients with neurogenic muscular atrophy. In the 4 BSMA patients, we subcloned the PCR products from muscles tissues and peripheral blood leukocytes, and we determined the number of CAG repeats by sequencing. The repeats of them were 43-51, and all BSMA patients showed the same number of CAG repeats in muscles tissues and peripheral blood leukocytes. The CAG repeats fragment of BSMA may be stable region in frozen storage state for 7 years, and we didn't recognized the somatic variation at least between muscles tissues and peripheral blood leukocytes.

  2. Bone mass and the CAG and GGN androgen receptor polymorphisms in young men.

    Directory of Open Access Journals (Sweden)

    Amelia Guadalupe-Grau

    Full Text Available BACKGROUND: To determine whether androgen receptor (AR CAG (polyglutamine and GGN (polyglycine polymorphisms influence bone mineral density (BMD, osteocalcin and free serum testosterone concentration in young men. METHODOLOGY/PRINCIPAL FINDINGS: Whole body, lumbar spine and femoral bone mineral content (BMC and BMD, Dual X-ray Absorptiometry (DXA, AR repeat polymorphisms (PCR, osteocalcin and free testosterone (ELISA were determined in 282 healthy men (28.6+/-7.6 years. Individuals were grouped as CAG short (CAG(S if harboring repeat lengths of 21, and GGN was considered short (GGN(S or long (GGN(L if GGN 23. There was an inverse association between logarithm of CAG and GGN length and Ward's Triangle BMC (r = -0.15 and -0.15, P<0.05, age and height adjusted. No associations between CAG or GGN repeat length and regional BMC or BMD were observed after adjusting for age. Whole body and regional BMC and BMD values were similar in men harboring CAG(S, CAG(L, GGN(S or GGN(L AR repeat polymorphisms. Men harboring the combination CAG(L+GGN(L had 6.3 and 4.4% higher lumbar spine BMC and BMD than men with the haplotype CAG(S+GGN(S (both P<0.05. Femoral neck BMD was 4.8% higher in the CAG(S+GGN(S compared with the CAG(L+GGN(S men (P<0.05. CAG(S, CAG(L, GGN(S, GGN(L men had similar osteocalcin concentration as well as the four CAG-GGN haplotypes studied. CONCLUSION: AR polymorphisms have an influence on BMC and BMD in healthy adult humans, which cannot be explained through effects in osteoblastic activity.

  3. Huntington's disease and mitochondrial DNA deletions: event or regular mechanism for mutant huntingtin protein and CAG repeats expansion?!

    Science.gov (United States)

    Banoei, Mohammad Mehdi; Houshmand, Massoud; Panahi, Mehdi Shafa Shariat; Shariati, Parvin; Rostami, Maryam; Manshadi, Masoumeh Dehghan; Majidizadeh, Tayebeh

    2007-11-01

    The mitochondrial DNA (mtDNA) may play an essential role in the pathogenesis of the respiratory chain complex activities in neurodegenerative disorders such as Huntington's disease (HD). Research studies were conducted to determine the possible levels of mitochondrial defect (deletion) in HD patients and consideration of interaction between the expanded Huntingtin gene as a nuclear gene and mitochondria as a cytoplasmic organelle. To determine mtDNA damage, we investigated deletions based in four areas of mitochondrial DNA, in a group of 60 Iranian patients clinically diagnosed with HD and 70 healthy controls. A total of 41 patients out of 60 had CAG expansion (group A). About 19 patients did not show expansion but had the clinical symptoms of HD (group B). MtDNA deletions were classified into four groups according to size; 9 kb, 7.5 kb, 7 kb, and 5 kb. We found one of the four-mtDNA deletions in at least 90% of samples. Multiple deletions have also been observed in 63% of HD patients. None of the normal control (group C) showed mtDNA deletions. The sizes or locations of the deletions did not show a clear correlation with expanded CAG repeat and age in our samples. The study presented evidence that HD patients had higher frequencies of mtDNA deletions in lymphocytes in comparison to the controls. It is thus proposed that CAG repeats instability and mutant Htt are causative factor in mtDNA damage.

  4. Three Huntington's Disease Specific Mutation-Carrying Human Embryonic Stem Cell Lines Have Stable Number of CAG Repeats upon In Vitro Differentiation into Cardiomyocytes.

    Science.gov (United States)

    Jacquet, Laureen; Neueder, Andreas; Földes, Gabor; Karagiannis, Panagiotis; Hobbs, Carl; Jolinon, Nelly; Mioulane, Maxime; Sakai, Takao; Harding, Sian E; Ilic, Dusko

    2015-01-01

    Huntington disease (HD; OMIM 143100), a progressive neurodegenerative disorder, is caused by an expanded trinucleotide CAG (polyQ) motif in the HTT gene. Cardiovascular symptoms, often present in early stage HD patients, are, in general, ascribed to dysautonomia. However, cardio-specific expression of polyQ peptides caused pathological response in murine models, suggesting the presence of a nervous system-independent heart phenotype in HD patients. A positive correlation between the CAG repeat size and severity of symptoms observed in HD patients has also been observed in in vitro HD cellular models. Here, we test the suitability of human embryonic stem cell (hESC) lines carrying HD-specific mutation as in vitro models for understanding molecular mechanisms of cardiac pathology seen in HD patients. We have differentiated three HD-hESC lines into cardiomyocytes and investigated CAG stability up to 60 days after starting differentiation. To assess CAG stability in other tissues, the lines were also subjected to in vivo differentiation into teratomas for 10 weeks. Neither directed differentiation into cardiomyocytes in vitro nor in vivo differentiation into teratomas, rich in immature neuronal tissue, led to an increase in the number of CAG repeats. Although the CAG stability might be cell line-dependent, induced pluripotent stem cells generated from patients with larger numbers of CAG repeats could have an advantage as a research tool for understanding cardiac symptoms of HD patients.

  5. Three Huntington's Disease Specific Mutation-Carrying Human Embryonic Stem Cell Lines Have Stable Number of CAG Repeats upon In Vitro Differentiation into Cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Laureen Jacquet

    Full Text Available Huntington disease (HD; OMIM 143100, a progressive neurodegenerative disorder, is caused by an expanded trinucleotide CAG (polyQ motif in the HTT gene. Cardiovascular symptoms, often present in early stage HD patients, are, in general, ascribed to dysautonomia. However, cardio-specific expression of polyQ peptides caused pathological response in murine models, suggesting the presence of a nervous system-independent heart phenotype in HD patients. A positive correlation between the CAG repeat size and severity of symptoms observed in HD patients has also been observed in in vitro HD cellular models. Here, we test the suitability of human embryonic stem cell (hESC lines carrying HD-specific mutation as in vitro models for understanding molecular mechanisms of cardiac pathology seen in HD patients. We have differentiated three HD-hESC lines into cardiomyocytes and investigated CAG stability up to 60 days after starting differentiation. To assess CAG stability in other tissues, the lines were also subjected to in vivo differentiation into teratomas for 10 weeks. Neither directed differentiation into cardiomyocytes in vitro nor in vivo differentiation into teratomas, rich in immature neuronal tissue, led to an increase in the number of CAG repeats. Although the CAG stability might be cell line-dependent, induced pluripotent stem cells generated from patients with larger numbers of CAG repeats could have an advantage as a research tool for understanding cardiac symptoms of HD patients.

  6. Critical nucleus size for disease-related polyglutamine aggregation is repeat length dependent

    Science.gov (United States)

    Kar, Karunakar; Jayaraman, Murali; Sahoo, Bankanidhi; Kodali, Ravindra; Wetzel, Ronald

    2010-01-01

    Since polyglutamine (polyQ) aggregate formation has been implicated as playing an important role in expanded CAG repeat diseases, it is important to understand the biophysics underlying the initiation of aggregation. Previously we showed that relatively long polyQ peptides aggregate by nucleated growth polymerization and a monomeric critical nucleus. We show here that, over a short repeat length range from Q26 to Q23, the size of the critical nucleus for aggregation increases from monomeric to dimeric to tetrameric. This variation in nucleus size suggests a common duplex anti-parallel β-sheet framework for the nucleus, and further supports the feasibility of an organized monomeric aggregation nucleus for longer polyQ repeat peptides. The data also suggest that a change in aggregation nucleus size may play a role in the pathogenicity of polyQ expansion in this series of familial neurodegenerative diseases. PMID:21317897

  7. Normal CAG and CCG repeats in the Huntington`s disease genes of Parkinson`s disease patients

    Energy Technology Data Exchange (ETDEWEB)

    Rubinsztein, D.C.; Leggo, J.; Barton, D.E. [Cambridge Univ. (United Kingdom)] [and others

    1995-04-24

    The clinical features of Parkinson`s disease, particularly rigidity and bradykinesia and occasionally tremor, are seen in juvenile-onset Huntington`s disease. Therefore, the CAG and CCG repeats in the Huntington`s disease gene were investigated in 45 Parkinson`s disease patients and compared to 40 control individuals. All of the Parkinson`s disease chromosomes fell within the normal size ranges. In addition, the distributions of the two repeats in the Parkinson`s disease patients did not differ significantly from those of the control population. Therefore, abnormalities of these trinucleotide repeats in the Huntington`s disease gene are not likely to contribute to the pathogenesis of Parkinson`s disease. 12 refs., 2 figs.

  8. Distinct repeat motifs at the C-terminal region of CagA of Helicobacter pylori strains isolated from diseased patients and asymptomatic individuals in West Bengal, India

    Directory of Open Access Journals (Sweden)

    Chattopadhyay Santanu

    2012-05-01

    Full Text Available Abstract Background Infection with Helicobacter pylori strains that express CagA is associated with gastritis, peptic ulcer disease, and gastric adenocarcinoma. The biological function of CagA depends on tyrosine phosphorylation by a cellular kinase. The phosphate acceptor tyrosine moiety is present within the EPIYA motif at the C-terminal region of the protein. This region is highly polymorphic due to variations in the number of EPIYA motifs and the polymorphism found in spacer regions among EPIYA motifs. The aim of this study was to analyze the polymorphism at the C-terminal end of CagA and to evaluate its association with the clinical status of the host in West Bengal, India. Results Seventy-seven H. pylori strains isolated from patients with various clinical statuses were used to characterize the C-ternimal polymorphic region of CagA. Our analysis showed that there is no correlation between the previously described CagA types and various disease outcomes in Indian context. Further analyses of different CagA structures revealed that the repeat units in the spacer sequences within the EPIYA motifs are actually more discrete than the previously proposed models of CagA variants. Conclusion Our analyses suggest that EPIYA motifs as well as the spacer sequence units are present as distinct insertions and deletions, which possibly have arisen from extensive recombination events. Moreover, we have identified several new CagA types, which could not be typed by the existing systems and therefore, we have proposed a new typing system. We hypothesize that a cagA gene encoding higher number EPIYA motifs may perhaps have arisen from cagA genes that encode lesser EPIYA motifs by acquisition of DNA segments through recombination events.

  9. Tandem CAG repeats of the androgen receptor gene and prostate cancer risk in black and white men.

    Science.gov (United States)

    Panz, V R; Joffe, B I; Spitz, I; Lindenberg, T; Farkas, A; Haffejee, M

    2001-07-01

    The most common malignancy in men worldwide is cancer of the prostate. Androgens play a direct role in normal and malignant growth of prostate cells via the androgen receptor (AR). This study analyzed the polymorphic CAG repeat sequence in exon 1 of the AR gene to determine if the number of repeats might be an indicator of prostate cancer risk or aggressive disease. DNA was extracted from blood samples of 20 black and 20 white men with well-documented prostate cancer and 40 healthy controls (20 blacks and 20 whites). PCR amplification was followed by gel electrophoresis and DNA sequencing. This region normally contains between 9 and 29 repeats. Patients and controls both had minor variations in the number of repeats, which ranged from 13 to 27 with 21 being the most frequent allele. Black controls and patients both had a mean of 20 +/- 3 repeats; in whites the mean was significantly lower in patients than controls (21 +/- 2 versus 23 +/- 2; p = 0.004). Combined black and white patients also had a lower number than the combined group of controls (20 +/- 3 versus 22 +/- 3; p = 0.02). Similarly, black and white patients with aggressive disease had a lower number than patients whose disease was more slowly progressive (19 +/- 2 versus 22 +/- 3; p = 0.02). We conclude that the small differences in the number of CAG repeats in both black and white patients do not appear to be a strong indicator of risk or aggressive disease but that this size polymorphism may be one of many genetic and environmental risk factors involved in prostate cancer.

  10. Androgen receptor CAG polymorphism and sporadic and early-onset prostate cancer among Mexican men.

    Science.gov (United States)

    Gómez, Rocío; Torres-Sánchez, Luisa; Camacho-Mejorado, Rafael; Burguete-García, Ana I; Vázquez-Salas, Ruth Argelia; Martínez-Nava, Gabriela A; Santana, Carla; Noris, Gino

    2016-09-01

    A short CAG repeat length in the gene encoding for the androgen receptor (AR) has been associated with prostate cancer (PC) risk and aggressiveness. In Latino men, information on this association is scarce. Hence, the aim of this study was to evaluate this association in Mexican males. Using fragment analysis by capillary electrophoresis, we determined the number of CAG repeats-(CAG)n-in AR gene from 158 incident PC cases and 326 age-matched healthy controls (±5 years), residing in Mexico City, Mexico. According to Gleason scale and age at diagnosis, cases were classified as high (⩾7) and low grade (CAG repeat length than controls (18.6±2.2 vs 19.5±2.5; P=0.02). Lower number of CAG repeats (CAG)⩽19 were associated with a greater risk for early-onset PC (odds ratio: 2.31; 95% confidence interval: 1.14-4.69). CAG repeat length could increase the risk for sporadic and early-onset PC. The best cutoff point for identifying at-risk subjects was (CAG)19. However, further studies are necessary to replicate our findings in subjects with a family history of PC and also to evaluate the association between CAG repeats length and disease progression.

  11. Negative association between androgen receptor gene CAG repeat polymorphism and polycystic ovary syndrome? A systematic review and meta-analysis.

    Science.gov (United States)

    Wang, Rui; Goodarzi, Mark O; Xiong, Ting; Wang, Di; Azziz, Ricardo; Zhang, Hanwang

    2012-10-01

    A number of studies focusing on the association between the exon 1 CAG repeat polymorphism of the androgen receptor (AR) gene and polycystic ovary syndrome (PCOS) have revealed conflicting results. The current systematic review and meta-analysis was conducted to quantify the strength of the association and to explore potential sources of heterogeneity that may have influenced the results. Studies matched to search terms from PubMed, EMBASE and HuGE Navigator published through to 31 January 2012 were retrieved. Data extraction from the included studies was carried out by two authors independently. Weighted mean differences (WMDs) of biallelic mean and odds ratios (ORs) of alleles and genotypes were pooled for meta-analysis. Sixteen articles reporting on 17 studies were included. In continuous data analysis, the summary WMD was -0.06 (95% confidence interval -0.29 to 0.16). In dichotomous data analysis, we divided the alleles into short and long alleles and calculated the summary ORs. No statistically significant results were identified by different comparison models or different cut-off point definitions. No publication bias was observed in continuous and dichotomous data analysis. In summary, the current systematic review and meta-analysis found that the AR CAG microsatellite repeat polymorphism is unlikely to be a major determining factor in the development of PCOS.

  12. Structural Insights Reveal the Dynamics of the Repeating r(CAG Transcript Found in Huntington's Disease (HD and Spinocerebellar Ataxias (SCAs.

    Directory of Open Access Journals (Sweden)

    Arpita Tawani

    Full Text Available In humans, neurodegenerative disorders such as Huntington's disease (HD and many spinocerebellar ataxias (SCAs have been found to be associated with CAG trinucleotide repeat expansion. An important RNA-mediated mechanism that causes these diseases involves the binding of the splicing regulator protein MBNL1 (Muscleblind-like 1 protein to expanded r(CAG repeats. Moreover, mutant huntingtin protein translated from expanded r(CAG also yields toxic effects. To discern the role of mutant RNA in these diseases, it is essential to gather information about its structure. Detailed insight into the different structures and conformations adopted by these mutant transcripts is vital for developing therapeutics targeting them. Here, we report the crystal structure of an RNA model with a r(CAG motif, which is complemented by an NMR-based solution structure obtained from restrained Molecular Dynamics (rMD simulation studies. Crystal structure data of the RNA model resolved at 2.3 Å reveals non-canonical pairing of adenine in 5´-CAG/3´-GAC motif samples in different syn and anti conformations. The overall RNA structure has helical parameters intermediate to the A- and B-forms of nucleic acids due to the global widening of major grooves and base-pair preferences near internal AA loops. The comprehension of structural behaviour by studying the spectral features and the dynamics also supports the flexible nature of the r(CAG motif.

  13. Structural Insights Reveal the Dynamics of the Repeating r(CAG) Transcript Found in Huntington's Disease (HD) and Spinocerebellar Ataxias (SCAs).

    Science.gov (United States)

    Tawani, Arpita; Kumar, Amit

    2015-01-01

    In humans, neurodegenerative disorders such as Huntington's disease (HD) and many spinocerebellar ataxias (SCAs) have been found to be associated with CAG trinucleotide repeat expansion. An important RNA-mediated mechanism that causes these diseases involves the binding of the splicing regulator protein MBNL1 (Muscleblind-like 1 protein) to expanded r(CAG) repeats. Moreover, mutant huntingtin protein translated from expanded r(CAG) also yields toxic effects. To discern the role of mutant RNA in these diseases, it is essential to gather information about its structure. Detailed insight into the different structures and conformations adopted by these mutant transcripts is vital for developing therapeutics targeting them. Here, we report the crystal structure of an RNA model with a r(CAG) motif, which is complemented by an NMR-based solution structure obtained from restrained Molecular Dynamics (rMD) simulation studies. Crystal structure data of the RNA model resolved at 2.3 Å reveals non-canonical pairing of adenine in 5´-CAG/3´-GAC motif samples in different syn and anti conformations. The overall RNA structure has helical parameters intermediate to the A- and B-forms of nucleic acids due to the global widening of major grooves and base-pair preferences near internal AA loops. The comprehension of structural behaviour by studying the spectral features and the dynamics also supports the flexible nature of the r(CAG) motif.

  14. Potential Transfer of Polyglutamine and CAG-Repeat RNA in Extracellular Vesicles in Huntington's Disease: Background and Evaluation in Cell Culture.

    Science.gov (United States)

    Zhang, Xuan; Abels, Erik R; Redzic, Jasmina S; Margulis, Julia; Finkbeiner, Steve; Breakefield, Xandra O

    2016-04-01

    In Huntington's disease (HD) the imperfect expanded CAG repeat in the first exon of the HTT gene leads to the generation of a polyglutamine (polyQ) protein, which has some neuronal toxicity, potentially mollified by formation of aggregates. Accumulated research, reviewed here, implicates both the polyQ protein and the expanded repeat RNA in causing toxicity leading to neurodegeneration in HD. Different theories have emerged as to how the neurodegeneration spreads throughout the brain, with one possibility being the transport of toxic protein and RNA in extracellular vesicles (EVs). Most cell types in the brain release EVs and these have been shown to contain neurodegenerative proteins in the case of prion protein and amyloid-beta peptide. In this study, we used a model culture system with an overexpression of HTT-exon 1 polyQ-GFP constructs in human 293T cells and found that the EVs did incorporate both the polyQ-GFP protein and expanded repeat RNA. Striatal mouse neural cells were able to take up these EVs with a consequent increase in the green fluorescent protein (GFP) and polyQ-GFP RNAs, but with no evidence of uptake of polyQ-GFP protein or any apparent toxicity, at least over a relatively short period of exposure. A differentiated striatal cell line expressing endogenous levels of Hdh mRNA containing the expanded repeat incorporated more of this mRNA into EVs as compared to similar cells expressing this mRNA with a normal repeat length. These findings support the potential of EVs to deliver toxic expanded trinucleotide repeat RNAs from one cell to another, but further work will be needed to evaluate potential EV and cell-type specificity of transfer and effects of long-term exposure. It seems likely that expanded HD-associated repeat RNA may appear in biofluids and may have use as biomarkers of disease state and response to therapy.

  15. Intermediate CAG repeat expansion in the ATXN2 gene is a unique genetic risk factor for ALS--a systematic review and meta-analysis of observational studies.

    Directory of Open Access Journals (Sweden)

    Ming-Dong Wang

    Full Text Available Amyotrophic lateral sclerosis (ALS is a rare degenerative condition of the motor neurons. Over 10% of ALS cases are linked to monogenic mutations, with the remainder thought to be due to other risk factors, including environmental factors, genetic polymorphisms, and possibly gene-environmental interactions. We examined the association between ALS and an intermediate CAG repeat expansion in the ATXN2 gene using a meta-analytic approach. Observational studies were searched with relevant disease and gene terms from MEDLINE, EMBASE, and PsycINFO from January 2010 through to January 2014. All identified articles were screened using disease terms, gene terms, population information, and CAG repeat information according to PRISMA guidelines. The final list of 17 articles was further evaluated based on the study location, time period, and authors to exclude multiple usage of the same study populations: 13 relevant articles were retained for this study. The range 30-33 CAG repeats in the ATXN2 gene was most strongly associated with ALS. The meta-analysis revealed that the presence of an intermediate CAG repeat (30-33 in the ATXN2 gene was associated with an increased risk of ALS [odds ratio (OR = 4.44, 95%CI: 2.91-6.76] in Caucasian ALS patients. There was no significant difference in the association of this CAG intermediate repeat expansion in the ATXN2 gene between familial ALS cases (OR = 3.59, 1.58-8.17 and sporadic ALS cases (OR = 3.16, 1.88-5.32. These results indicate that the presence of intermediate CAG repeat expansion in the ATXN2 gene is a specific genetic risk factor for ALS, unlike monogenic mutations with an autosomal dominant transmission mode, which cause a more severe phenotype of ALS, with a higher prevalence in familial ALS.

  16. Intermediate CAG repeat expansion in the ATXN2 gene is a unique genetic risk factor for ALS--a systematic review and meta-analysis of observational studies.

    Science.gov (United States)

    Wang, Ming-Dong; Gomes, James; Cashman, Neil R; Little, Julian; Krewski, Daniel

    2014-01-01

    Amyotrophic lateral sclerosis (ALS) is a rare degenerative condition of the motor neurons. Over 10% of ALS cases are linked to monogenic mutations, with the remainder thought to be due to other risk factors, including environmental factors, genetic polymorphisms, and possibly gene-environmental interactions. We examined the association between ALS and an intermediate CAG repeat expansion in the ATXN2 gene using a meta-analytic approach. Observational studies were searched with relevant disease and gene terms from MEDLINE, EMBASE, and PsycINFO from January 2010 through to January 2014. All identified articles were screened using disease terms, gene terms, population information, and CAG repeat information according to PRISMA guidelines. The final list of 17 articles was further evaluated based on the study location, time period, and authors to exclude multiple usage of the same study populations: 13 relevant articles were retained for this study. The range 30-33 CAG repeats in the ATXN2 gene was most strongly associated with ALS. The meta-analysis revealed that the presence of an intermediate CAG repeat (30-33) in the ATXN2 gene was associated with an increased risk of ALS [odds ratio (OR) = 4.44, 95%CI: 2.91-6.76)] in Caucasian ALS patients. There was no significant difference in the association of this CAG intermediate repeat expansion in the ATXN2 gene between familial ALS cases (OR = 3.59, 1.58-8.17) and sporadic ALS cases (OR = 3.16, 1.88-5.32). These results indicate that the presence of intermediate CAG repeat expansion in the ATXN2 gene is a specific genetic risk factor for ALS, unlike monogenic mutations with an autosomal dominant transmission mode, which cause a more severe phenotype of ALS, with a higher prevalence in familial ALS.

  17. Association between proton magnetic resonance spectroscopy measurements and CAG repeat number in patients with spinocerebellar ataxias 2, 3, or 6.

    Directory of Open Access Journals (Sweden)

    Po-Shan Wang

    Full Text Available The aim of this study was to correlate magnetic resonance spectroscopy (MRS measurements, including that for the N-acetyl aspartate (NAA/creatine (Cr ratio in the vermis (denoted V-NAA, right cerebellar hemisphere (R-NAA, and left (L-NAA cerebellar hemisphere, with the clinical scale for the assessment and rating of ataxia (SARA score for patients with spinocerebellar ataxia (SCA types 2, 3, and 6. A total of 24 patients with SCA2, 48 with SCA3, and 16 with SCA6 were recruited; 12 patients with SCA2, 43 with SCA3, and 8 with SCA6 underwent detailed magnetic resonance neuroimaging. Forty-four healthy, age-matched individuals without history of neurologic disease served as control subjects. V-NAA and patient age were used to calculate the predicted age at which a patient with SCA2 or SCA3 would reach an onset V-NAA value. Results showed the following: the NAA/Cr ratio decreased with increasing age in patients with SCA but not in control subjects; the SARA score increased progressively with age and duration of illness; V-NAA showed a better correlation with SARA score than R-NAA in patients with SCA2 or SCA3; the ratio of age to V-NAA correlated well with CAG repeat number; the retrospectively predicted age of onset for SCA2 and SCA3 was consistent with patient-reported age of onset; R-NAA showed a better correlation with SARA score than V-NAA in patients with SCA6; V-NAA and R-NAA correlated with clinical severity (SARA score in patients with SCA. The correlation between CAG repeat number and age could be expressed as a simple linear function, which might explain previous observations claiming that the greater the CAG repeat number, the earlier the onset of illness and the faster the disease progression. These findings support the use of MRS values to predict age of disease onset and to retrospectively evaluate the actual age of disease onset in SCA.

  18. Association between proton magnetic resonance spectroscopy measurements and CAG repeat number in patients with spinocerebellar ataxias 2, 3, or 6.

    Science.gov (United States)

    Wang, Po-Shan; Chen, Hung-Chieh; Wu, Hsiu-Mei; Lirng, Jiing-Feng; Wu, Yu-Te; Soong, Bing-Wen

    2012-01-01

    The aim of this study was to correlate magnetic resonance spectroscopy (MRS) measurements, including that for the N-acetyl aspartate (NAA)/creatine (Cr) ratio in the vermis (denoted V-NAA), right cerebellar hemisphere (R-NAA), and left (L-NAA) cerebellar hemisphere, with the clinical scale for the assessment and rating of ataxia (SARA) score for patients with spinocerebellar ataxia (SCA) types 2, 3, and 6. A total of 24 patients with SCA2, 48 with SCA3, and 16 with SCA6 were recruited; 12 patients with SCA2, 43 with SCA3, and 8 with SCA6 underwent detailed magnetic resonance neuroimaging. Forty-four healthy, age-matched individuals without history of neurologic disease served as control subjects. V-NAA and patient age were used to calculate the predicted age at which a patient with SCA2 or SCA3 would reach an onset V-NAA value. Results showed the following: the NAA/Cr ratio decreased with increasing age in patients with SCA but not in control subjects; the SARA score increased progressively with age and duration of illness; V-NAA showed a better correlation with SARA score than R-NAA in patients with SCA2 or SCA3; the ratio of age to V-NAA correlated well with CAG repeat number; the retrospectively predicted age of onset for SCA2 and SCA3 was consistent with patient-reported age of onset; R-NAA showed a better correlation with SARA score than V-NAA in patients with SCA6; V-NAA and R-NAA correlated with clinical severity (SARA score) in patients with SCA. The correlation between CAG repeat number and age could be expressed as a simple linear function, which might explain previous observations claiming that the greater the CAG repeat number, the earlier the onset of illness and the faster the disease progression. These findings support the use of MRS values to predict age of disease onset and to retrospectively evaluate the actual age of disease onset in SCA.

  19. Twisting right to left: A…A mismatch in a CAG trinucleotide repeat overexpansion provokes left-handed Z-DNA conformation.

    Science.gov (United States)

    Khan, Noorain; Kolimi, Narendar; Rathinavelan, Thenmalarchelvi

    2015-04-01

    Conformational polymorphism of DNA is a major causative factor behind several incurable trinucleotide repeat expansion disorders that arise from overexpansion of trinucleotide repeats located in coding/non-coding regions of specific genes. Hairpin DNA structures that are formed due to overexpansion of CAG repeat lead to Huntington's disorder and spinocerebellar ataxias. Nonetheless, DNA hairpin stem structure that generally embraces B-form with canonical base pairs is poorly understood in the context of periodic noncanonical A…A mismatch as found in CAG repeat overexpansion. Molecular dynamics simulations on DNA hairpin stems containing A…A mismatches in a CAG repeat overexpansion show that A…A dictates local Z-form irrespective of starting glycosyl conformation, in sharp contrast to canonical DNA duplex. Transition from B-to-Z is due to the mechanistic effect that originates from its pronounced nonisostericity with flanking canonical base pairs facilitated by base extrusion, backbone and/or base flipping. Based on these structural insights we envisage that such an unusual DNA structure of the CAG hairpin stem may have a role in disease pathogenesis. As this is the first study that delineates the influence of a single A…A mismatch in reversing DNA helicity, it would further have an impact on understanding DNA mismatch repair.

  20. Twisting right to left: A…A mismatch in a CAG trinucleotide repeat overexpansion provokes left-handed Z-DNA conformation.

    Directory of Open Access Journals (Sweden)

    Noorain Khan

    2015-04-01

    Full Text Available Conformational polymorphism of DNA is a major causative factor behind several incurable trinucleotide repeat expansion disorders that arise from overexpansion of trinucleotide repeats located in coding/non-coding regions of specific genes. Hairpin DNA structures that are formed due to overexpansion of CAG repeat lead to Huntington's disorder and spinocerebellar ataxias. Nonetheless, DNA hairpin stem structure that generally embraces B-form with canonical base pairs is poorly understood in the context of periodic noncanonical A…A mismatch as found in CAG repeat overexpansion. Molecular dynamics simulations on DNA hairpin stems containing A…A mismatches in a CAG repeat overexpansion show that A…A dictates local Z-form irrespective of starting glycosyl conformation, in sharp contrast to canonical DNA duplex. Transition from B-to-Z is due to the mechanistic effect that originates from its pronounced nonisostericity with flanking canonical base pairs facilitated by base extrusion, backbone and/or base flipping. Based on these structural insights we envisage that such an unusual DNA structure of the CAG hairpin stem may have a role in disease pathogenesis. As this is the first study that delineates the influence of a single A…A mismatch in reversing DNA helicity, it would further have an impact on understanding DNA mismatch repair.

  1. Analysis of the CAG repeat region of the androgen receptor gene in a kindred with X-linked spinal and bulbar muscular atrophy.

    Science.gov (United States)

    Belsham, D D; Yee, W C; Greenberg, C R; Wrogemann, K

    1992-10-01

    Herein we describe a family with X-linked spinal and bulbar muscular atrophy (SBMA or Kennedy's disease), an adult onset neuromuscular disease characterized by slow progression, predominant proximal and bulbar muscle weakness. One frequent association is the appearance of gynecomastia. This disorder was previously shown to be linked to the locus DXYS1 on the proximal long arm of the X chromosome. Recently, a report implicated a mutation at the N-terminus of the androgen receptor gene involving amplification of CAG repeats as the cause of X-linked SBMA. We studied this region of the androgen receptor in a kindred clinically suspected but not confirmed of having X-linked SBMA by the polymerase chain reaction (PCR) followed by Southern analysis and DNA sequencing. The mutated allele was found to have an increased number of 51 CAG repeats confirming the clinical diagnosis of SBMA. Normal individuals revealed 23 repeat numbers within the normal range, while another unrelated X-linked SBMA patient had an enlarged CAG repeat region. The carrier or disease status could be established or confirmed in 12 individuals of this family on the basis of detecting normal and disease alleles reflected by the number of CAG repeats.

  2. Association of the polymorphism of the CAG repeat in the mitochondrial DNA polymerase gamma gene (POLG) with testicular germ-cell cancer

    DEFF Research Database (Denmark)

    Blomberg Jensen, M; Leffers, H; Petersen, J H

    2008-01-01

    BACKGROUND: A possible association between the polymorphic CAG repeat in the DNA polymerase gamma (POLG) gene and the risk of testicular germ-cell tumours (TGCT) was investigated in this study. The hypothesis was prompted by an earlier preliminary study proposing an association of the absence...

  3. Spinocerebellar ataxia type 7 (SCA7): First report of a systematic neuropathological study of the brain of a patient with a very short expanded CAG-repeat

    NARCIS (Netherlands)

    Rub, U.; Brunt, E.R.; Gierga, K.; Seidel, K.; Schultz, C.; Schols, L.; Auburger, G.; Heinsen, H.; Ippel, P.F.; Glimmerveen, W.F.; Wittebol-Post, D.; Arai, K.; Deller, T.; Rai, D.

    2005-01-01

    Spinocerebellar ataxia type 7 (SCA7) represents a very rare and severe autosomal dominantly inherited cerebellar ataxia (ADCA). It belongs to the group of CAG-repeat or polyglutamine diseases with its underlying molecular genetical defect on chromosome 3p12-p21.1. Here, we performed a systematic stu

  4. Spinocerebellar ataxia type 7 (SCA7) : First report of a systematic neuropathological study of the brain of a patient with a very short expanded CAG-repeat

    NARCIS (Netherlands)

    Rub, U; Brunt, ER; Gierga, K; Seidel, K; Schultz, C; Schols, L; Auburger, G; Heinsen, H; Ippel, PF; Glimmerveen, WF; Wittebol-Post, D; Arai, K; Deller, T; Rai, D

    2005-01-01

    Spinocerebellar ataxia type 7 (SCA7) represents a very rare and severe autosomal dominantly inherited cerebellar ataxia (ADCA). It belongs to the group of CAG-repeat or polyglutamine diseases with its underlying molecular genetical defect on chromosome 3p12-p21.1. Here, we performed a systematic stu

  5. Analysis of the CAG repeat number in exon 1 of the androgen receptor gene in Slovene men with idiopathic azoospermia and oligoasthenoteratozoospermia

    Institute of Scientific and Technical Information of China (English)

    Borut Peterlin; Branko Zorn; Natasa Teran; Tanja Kunej

    2007-01-01

    @@ Dear Sir, I am Borut Peterlin, from Division of Medical Genetics,Department of Obstetrics and Gynaecology, University Medical Center, Ljubljana, Slovenia. We write to you to discuss if the number of CAG repeats in the androgen receptor (AR) gene is associated with male infertility in a group of 190 Slovene infertile men compared to 137 men with proven fertility.

  6. Contributions by the CAG-repeat Polymorphism of the Androgen Receptor Gene and Circulating Androgens to Muscle Size. Odense Androgen Study - A Population-based Study of 20-29 Year-old Danish Men

    DEFF Research Database (Denmark)

    Nielsen, Torben Leo; Hagen, Claus; Wraae, Kristian;

    2007-01-01

    Context: The number of CAG-repeats within the CAG-repeat polymorphism of the androgen receptor gene is inversely correlated with the transcriptional activity of the androgen receptor. Objective: To study the effect of the CAG-repeat number and circulating androgens on muscle size, to examine......-repeat number correlated inversely with thigh and axial muscle area and with lower and upper extremity lean body mass. Except for upper extremity lean body mass, these findings remained significant in multivariate analyses controlling for circulating androgens, physical activity, smoking, alcohol intake...

  7. Random rapid amplification of cDNA ends (RRACE) allows for cloning of multiple novel human cDNA fragments containing (CAG)n repeats.

    Science.gov (United States)

    Carney, J P; McKnight, C; VanEpps, S; Kelley, M R

    1995-04-03

    We describe a new technique for isolating cDNA fragments in which (i) either a partial sequence of the cDNA is known or (ii) a repeat sequence is utilized. We have used this technique, termed random rapid amplification of cDNA ends (random RACE), to isolate a number of trinucleotide repeat (CAG)n-containing genes. Using the random RACE (RRACE) technique, we have isolated over a hundred (CAG)n-containing genes. The results of our initial analysis of ten clones indicate that three are identical to previously cloned (CAG)n-containing genes. Three of our clones matched with expressed sequence tags, one of which contained a CA repeat. The remaining four clones did not match with any sequence in GenBank. These results indicate that this approach provides a rapid and efficient method for isolating trinucleotide repeat-containing cDNA fragments. Finally, this technique may be used for purposes other than cloning repeat-containing cDNA fragments. If only a partial sequence of a gene is known, our system, described here, provides a rapid and efficient method for isolating a fragment of the gene of interest.

  8. Longitudinal behavioral, cross-sectional transcriptional and histopathological characterization of a knock-in mouse model of Huntington's disease with 140 CAG repeats.

    Science.gov (United States)

    Rising, Aaron C; Xu, Jia; Carlson, Aaron; Napoli, Vincent V; Denovan-Wright, Eileen M; Mandel, Ronald J

    2011-04-01

    The discovery of the gene mutation responsible for Huntington's disease (HD), huntingtin, in 1993 allowed for a better understanding of the pathology of and enabled the development of animal models. HD is caused by the expansion of a polyglutamine repeat region in the N-terminal of the huntingtin protein. Here we examine the behavioral, transcriptional, histopathological and anatomical characteristics of a knock-in HD mouse model with a 140 polyglutamine expansion in the huntingtin protein. This CAG 140 model contains a portion of the human exon 1 with 140 CAG repeats knocked into the mouse huntingtin gene. We have longitudinally examined the rearing behavior, accelerating rotarod, constant speed rotarod and gait for age-matched heterozygote, homozygote and non-transgenic mice and have found a significant difference in the afflicted mice. However, while there were significant differences between the non-transgenic and the knock-in mice, these behaviors were not progressive. As in HD, we show that the CAG 140 mice also have a significant decrease in striatally enriched mRNA transcripts. In addition, striatal neuronal intranuclear inclusion density increases with age. Lastly these CAG 140 mice show slight cortical thinning compared to non-transgenic mice, similarly to the cortical thinning recently reported in HD.

  9. An antisense CAG repeat transcript at JPH3 locus mediates expanded polyglutamine protein toxicity in Huntington's disease-like 2 mice.

    Science.gov (United States)

    Wilburn, Brian; Rudnicki, Dobrila D; Zhao, Jing; Weitz, Tara Murphy; Cheng, Yin; Gu, Xiaofeng; Greiner, Erin; Park, Chang Sin; Wang, Nan; Sopher, Bryce L; La Spada, Albert R; Osmand, Alex; Margolis, Russell L; Sun, Yi E; Yang, X William

    2011-05-12

    Huntington's disease-like-2 (HDL2) is a phenocopy of Huntington's disease caused by CTG/CAG repeat expansion at the Junctophilin-3 (JPH3) locus. The mechanisms underlying HDL2 pathogenesis remain unclear. Here we developed a BAC transgenic mouse model of HDL2 (BAC-HDL2) that exhibits progressive motor deficits, selective neurodegenerative pathology, and ubiquitin-positive nuclear inclusions (NIs). Molecular analyses reveal a promoter at the transgene locus driving the expression of a CAG repeat transcript (HDL2-CAG) from the strand antisense to JPH3, which encodes an expanded polyglutamine (polyQ) protein. Importantly, BAC-HDL2 mice, but not control BAC mice, accumulate polyQ-containing NIs in a pattern strikingly similar to those in the patients. Furthermore, BAC mice with genetic silencing of the expanded CUG transcript still express HDL2-CAG transcript and manifest polyQ pathogenesis. Finally, studies of HDL2 mice and patients revealed CBP sequestration into NIs and evidence for interference of CBP-mediated transcriptional activation. These results suggest overlapping polyQ-mediated pathogenic mechanisms in HD and HDL2.

  10. The SCA1 (Spinocerebellar ataxia type 1 and MJD (Machado-Joseph disease CAG repeats in normal individuals: segregation analysis and allele frequencies

    Directory of Open Access Journals (Sweden)

    Cláudia Emília Vieira Wiezel

    2003-01-01

    Full Text Available Spinocerebellar ataxia type 1 (SCA1 and Machado-Joseph disease (MJD/SCA3 are autosomal dominant neurodegenerative diseases caused by expansions of a CAG trinucleotide repeat in the SCA1 and MJD genes. These expanded sequences are unstable upon transmission, leading to an intergeneration increase in the number of repeats (dynamic mutation. The transmission of the CAG repeat was studied in normal mother-father-child trios, referred for paternity testing (SCA1, n = 367; MJD, n = 879. No segregation distortion was detected. The CAG allele frequencies were determined in 330 unrelated individuals (fathers from couples tested for paternity. The allele frequency distributions did not differ from those previously reported for European populations. The estimated values for the statistic parameters indicating diversity at the SCA1 locus did not differ much from those reported previously for other STRs in the Brazilian population, while those for the MJD locus were close to or higher than the maximum values of previous reports. This shows that SCA1 and MJD are highly informative loci for applications in genetic and population studies and for forensic analysis.

  11. Multiple repeats of Helicobacter pylori CagA EPIYA-C phosphorylation sites predict risk of gastric ulcer in Iran.

    Science.gov (United States)

    Honarmand-Jahromy, Sahar; Siavoshi, Farideh; Malekzadeh, Reza; Sattari, Taher Nejad; Latifi-Navid, Saeid

    2015-12-01

    Biological activity of Helicobacter pylori oncoprotein CagA is determined by a diversity in the tyrosine phosphorylation motif sites. In the present study, the diversity and the type of the H. pylori CagA EPIYA motifs and their association with gastric ulcer (GU) and duodenal ulcer (DU) in Iranian dyspeptic patients were assessed. PCR amplification, sequencing, and bioinformatic analysis were performed to determine the pattern of CagA EPIYA motifs. Of 168 H. pylori cagA(+) strains, the frequency of ABC was 93.50%, ABCCC 5.40%, ABC + ABCCC 0.6% and ABCC 0.6%. There was no EPIYA-D segment. The ABCCC pattern of EPIYA motif was more frequent in the H. pylori isolates from GU (8/50, 16%) than in those from chronic gastritis (CG) (0/81, 0%) (P = 0). In contrast, The ABC pattern of EPIYA motif was less frequent in the H. pylori isolates from GU (41/50, 82%) than in those from CG (80/81, 98.80%) (Age-sex-adjusted odds ratio (OR) = 0.020, 95% CI = 0.002-0.259; P = 0.003). The distribution of the ABC motif was almost the same in H. pylori isolates from CG (98.80%) and DU diseases (97.30%). There was no significant association between the number of CagA EPIYA-C segment and DU (P > 0.05). We have proposed that CagA from Iranian H. pylori strains were Western type and all strains had active phosphorylation sites. The three EPIYA-C motifs of CagA were more frequently observed in the H. pylori strains from GU; thus it might be an important biomarker for predicting the GU risk in Iran.

  12. Somatic mosaicism of expanded CAG repeats in brains of patients with dentatorubral-pallidoluysian atrophy: Cellular populaton-dependent dynamics of mitotic instability

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Hiroki; Onodera, Osamu; Igarashi, Shuichi; Oyake, Mutsuo [Niigata Univ. (Japan)] [and others

    1996-06-01

    Dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disease caused by unstable expansion of a CAG repeat in the DRPLA gene. We performed detailed quantitative analysis of the size and the size distribution (range) of the expanded CAG repeats in various regions of the CNS of eight autopsied patients with DRPLA. Expanded alleles (AE) showed considerable variations in size, as well as in range, depending on the region of the CNS, whereas normal alleles did not show such variations, which indicates the occurrence of somatic mosaicism of AE in the CNS. The AE in the cerebellar cortex were consistently smaller by two to five repeat units than those in the cerebellar white matter. Moreover, the AE in the cerebral cortex were smaller by one to four repeat units than those in the cerebral white matter. These results suggest that the smaller AE in the cerebellar and cerebral cortices represent those of neuronal cells. The ranges of the AE in the cerebral cortex, cerebral white matter, and cerebellar white matter showed considerable variation ranging from 9 to 23 repeat units, whereas those in the cerebellar cortex showed little variance and were {approximately}7 repeat units. The ranges of the AE in the cerebral cortex, cerebral white matter, and cerebellar white matter were much broader in patients with higher ages at death than they were in patients with lower ages at death, raising the possibility that the range of AE increases with time, as the result of mitotic instability of AE. 41 refs., 6 figs., 1 tab.

  13. Androgen receptor (CAG)n polymorphisms and breast cancer risk in a Han Chinese population.

    Science.gov (United States)

    Dang, J; Peng, L; Zhong, H J; Huo, Z H

    2015-08-28

    The androgen receptor (AR) is involved in the differentiation and growth of breast cancer. Genetic markers in the AR gene have a plausible role in modulating the risk of breast cancer. In this study, we studied the association of breast cancer and the trinucleotide repeat polymorphism (CAG)n in exon 1 of the AR gene in 202 patients with breast cancer and 183 healthy controls from our hospital (Yinchuan, China). Repeat lengths were determined by fluorescent DNA fragment analysis using the ABI GeneScan software and DNA sequencing. We detected 17 short tandem repeat alleles in exon 1 in the Han population of Ningxia Province, China. The CAG repeat number ranged from 14 to 31 and the frequency ranged from 0.339 to 24.460%. Generally, (CAG)n repeat lengths 22 were classified as long (L). No association was found between breast cancer and the S/L (CAG) variants. However, the frequency of the (CAG)25 repeats in the breast cancer group was significantly higher than that in the control group (P = 0.033, odds ratio = 1.790, 95% confidence interval = 1.044-3.069). These findings indicate a role for AR gene (CAG)n variations in breast cancer and might be informative for future genetic or biological studies on breast cancer, although these findings need replication in other populations.

  14. TPR repeats and ELTR pattern: length variation as a function evolution mechanism.

    Science.gov (United States)

    Yang, Ke-Qian

    2007-12-01

    TPR repeat was originally defined as a 34 amino acid structural repeat (TPR-34). Equal length tandem repeats (ELTR) was proposed to represent the ancestral repeat pattern. Length polymorphism of TPR repeats was analyzed using PATTINPROT, two new versions of TPR repeat of 40 and 42 amino acids were identified. These 'long' TPRs endow new functional capacities to the resulting proteins. A strong correlation between varied lengths and new functions supports the hypothesis that length variation is an underlying mechanism for the function evolution of repeat containing proteins.

  15. Ubiquitous expression of CUG or CAG trinucleotide repeat RNA causes common morphological defects in a Drosophila model of RNA-mediated pathology.

    Directory of Open Access Journals (Sweden)

    Kynan T Lawlor

    Full Text Available Expanded DNA repeat sequences are known to cause over 20 diseases, including Huntington's disease, several types of spinocerebellar ataxia and myotonic dystrophy type 1 and 2. A shared genetic basis, and overlapping clinical features for some of these diseases, indicate that common pathways may contribute to pathology. Multiple mechanisms, mediated by both expanded homopolymeric proteins and expanded repeat RNA, have been identified by the use of model systems, that may account for shared pathology. The use of such animal models enables identification of distinct pathways and their 'molecular hallmarks' that can be used to determine the contribution of each pathway in human pathology. Here we characterise a tergite disruption phenotype in adult flies, caused by ubiquitous expression of either untranslated CUG or CAG expanded repeat RNA. Using the tergite phenotype as a quantitative trait we define a new genetic system in which to examine 'hairpin' repeat RNA-mediated cellular perturbation. Further experiments use this system to examine whether pathways involving Muscleblind sequestration or Dicer processing, which have been shown to mediate repeat RNA-mediated pathology in other model systems, contribute to cellular perturbation in this model.

  16. The HTT CAG-Expansion Mutation Determines Age at Death but Not Disease Duration in Huntington Disease.

    Science.gov (United States)

    Keum, Jae Whan; Shin, Aram; Gillis, Tammy; Mysore, Jayalakshmi Srinidhi; Abu Elneel, Kawther; Lucente, Diane; Hadzi, Tiffany; Holmans, Peter; Jones, Lesley; Orth, Michael; Kwak, Seung; MacDonald, Marcy E; Gusella, James F; Lee, Jong-Min

    2016-02-04

    Huntington disease (HD) is caused by an expanded HTT CAG repeat that leads in a length-dependent, completely dominant manner to onset of a characteristic movement disorder. HD also displays early mortality, so we tested whether the expanded CAG repeat exerts a dominant influence on age at death and on the duration of clinical disease. We found that, as with clinical onset, HD age at death is determined by expanded CAG-repeat length and has no contribution from the normal CAG allele. Surprisingly, disease duration is independent of the mutation's length. It is also unaffected by a strong genetic modifier of HD motor onset. These findings suggest two parsimonious alternatives. (1) HD pathogenesis is driven by mutant huntingtin, but before or near motor onset, sufficient CAG-driven damage occurs to permit CAG-independent processes and then lead to eventual death. In this scenario, some pathological changes and their clinical correlates could still worsen in a CAG-driven manner after disease onset, but these CAG-related progressive changes do not themselves determine duration. Alternatively, (2) HD pathogenesis is driven by mutant huntingtin acting in a CAG-dependent manner with different time courses in multiple cell types, and the cellular targets that lead to motor onset and death are different and independent. In this scenario, processes driven by HTT CAG length lead directly to death but not via the striatal pathology associated with motor manifestations. Each scenario has important ramifications for the design and testing of potential therapeutics, especially those aimed at preventing or delaying characteristic motor manifestations.

  17. 5′CAG and 5′CTG Repeats Create Differential Impediment to the Progression of a Minimal Reconstituted T4 Replisome Depending on the Concentration of dNTPs

    Directory of Open Access Journals (Sweden)

    Emmanuelle Delagoutte

    2011-01-01

    Full Text Available Instability of repetitive sequences originates from strand misalignment during repair or replicative DNA synthesis. To investigate the activity of reconstituted T4 replisomes across trinucleotide repeats (TNRs during leading strand DNA synthesis, we developed a method to build replication miniforks containing a TNR unit of defined sequence and length. Each minifork consists of three strands, primer, leading strand template, and lagging strand template with a 5′ single-stranded (ss tail. Each strand is prepared independently, and the minifork is assembled by hybridization of the three strands. Using these miniforks and a minimal reconstituted T4 replisome, we show that during leading strand DNA synthesis, the dNTP concentration dictates which strand of the structure-forming 5′CAG/5′CTG repeat creates the strongest impediment to the minimal replication complex. We discuss this result in the light of the known fluctuation of dNTP concentration during the cell cycle and cell growth and the known concentration balance among individual dNTPs.

  18. Modelling studies on neurodegenerative disease-causing triplet repeat sequences d(GGC/GCC)n and d(CAG/CTG)n

    Indian Academy of Sciences (India)

    Shibasish Chowdhury; Manju Bansal

    2001-12-01

    Model building and molecular mechanics studies have been carried out to examine the potential structures for d(GGC/GCC)5 and d(CAG/CTG)5 that might relate to their biological function and association with triplet repeat expansion diseases. Model building studies suggested that hairpin and quadruplex structures could be formed with these repeat sequences. Molecular mechanics studies have demonstrated that the hairpin and hairpin dimer structures of triplet repeat sequences formed by looping out of the two strands are as favourable as the corresponding B-DNA type hetero duplex structures. Further, at high salt condition, Greek key type quadruplex structures are energetically comparable with hairpin dimer and B-DNA type duplex structures. All tetrads in the quadruplex structures are well stacked and provide favourable stacking energy values. Interestingly, in the energy minimized hairpin dimer and Greek key type quadruplex structures, all the bases even in the non-G tetrads are cyclically hydrogen bonded, even though the A, C and T-tetrads were not hydrogen bonded in the starting structures.

  19. Repeat length and RNA expression level are not primary determinants in CUG expansion toxicity in Drosophila models.

    Directory of Open Access Journals (Sweden)

    Gwenn Le Mée

    Full Text Available Evidence for an RNA gain-of-function toxicity has now been provided for an increasing number of human pathologies. Myotonic dystrophies (DM belong to a class of RNA-dominant diseases that result from RNA repeat expansion toxicity. Specifically, DM of type 1 (DM1, is caused by an expansion of CUG repeats in the 3'UTR of the DMPK protein kinase mRNA, while DM of type 2 (DM2 is linked to an expansion of CCUG repeats in an intron of the ZNF9 transcript (ZNF9 encodes a zinc finger protein. In both pathologies the mutant RNA forms nuclear foci. The mechanisms that underlie the RNA pathogenicity seem to be rather complex and not yet completely understood. Here, we describe Drosophila models that might help unravelling the molecular mechanisms of DM1-associated CUG expansion toxicity. We generated transgenic flies that express inducible repeats of different type (CUG or CAG and length (16, 240, 480 repeats and then analyzed transgene localization, RNA expression and toxicity as assessed by induced lethality and eye neurodegeneration. The only line that expressed a toxic RNA has a (CTG(240 insertion. Moreover our analysis shows that its level of expression cannot account for its toxicity. In this line, (CTG(240.4, the expansion inserted in the first intron of CG9650, a zinc finger protein encoding gene. Interestingly, CG9650 and (CUG(240.4 expansion RNAs were found in the same nuclear foci. In conclusion, we suggest that the insertion context is the primary determinant for expansion toxicity in Drosophila models. This finding should contribute to the still open debate on the role of the expansions per se in Drosophila and in human pathogenesis of RNA-dominant diseases.

  20. A method for the incremental expansion of polyglutamine repeats in recombinant proteins.

    Science.gov (United States)

    Robertson, Amy L; Bottomley, Stephen P

    2013-01-01

    The polyglutamine diseases are caused by the expansion of CAG repeats. A key step in understanding the disease mechanisms, at the DNA and protein level, is the ability to produce recombinant proteins with specific length glutamine tracts which is a time-consuming first step in setting up in vitro systems to study the effects of polyglutamine expansion. Described here is a PCR-based method for the amplification of CAG repeats, which we used to incrementally extend CAG length by 3-5 repeats per cycle. This method could be translated into various contexts where amplification of repeating elements is necessary.

  1. Molecular phylogeny analysis of full-length vacA and cagA genesfrom Helicobacter pylori%幽门螺杆菌vacA 和cagA 基因全长分子系统发育分析

    Institute of Scientific and Technical Information of China (English)

    杨泽民; 陈蔚文

    2012-01-01

    All amino acid full-length sequences of VacA and CagA proteins from Helicobacter pylori strains including vacA and cagA genes were downloaded from GenBank. Molecular phylogenic trees of VacA and CagA were constructed by ClastalX 2.0 and MEGA 5.05 software to understand phylogenetic relationships of vacA and cagA genes, clinical infection effects, and genotype characteristics of different clustering groups. The results showed that the phylogenetic trees of VacA and CagA recapitulated the same three-clustering groups, i.e., East Asia group 1 and 2 and Western group, and all H. pylori strains had similar distribution. The strains of East Asia group 1 were significantly higher in patients with atrophic gastritis. Genotype vacA contained mainly s1c/m1b ands1a/m1b, while genotype cagA was mostly EPIYA-ABD. The strains of East Asia group 2 were higher in patients with duodenal ulcer. Genotype vacA was mainly slc/m2 and sla/m2, while genotype cagA was mostly EPIYA-AB'C. The strains of Western group were higher in patients with duodenal ulcer and chronic gastritis than with atrophic gastritis. Genotype vacA was mainly s1a/m1a and s1b/m1a, while genotype cagA was mostly EPIYA-AB/B'CC. All of these results illustrated that there might be inheritant relationship of coevolution between vacA and cagA genes; East Asia group 1 and 2 and Western group had different vacA and cagA sub-genotypes, which had close relationship to its clinical infection effects. It might be necessary to deeply analyze vacA and cagA sub-genotypes in the research of H. pylori-related diseases.%文章从GenBank 中下载所有含有vacA 和cagA 基因的H.pylori 菌株的VacA 和CagA全长氨基酸序列,利用ClastalX 2.0 和MEGA 5.05 软件构建VacA 和CagA 分子系统发育树,探讨两基因之间的分子系统发育关系和不同聚类群的临床感染结果与基因型特征.结果显示,VacA 和CagA 具有高度相似的分子系统发育树,并且所有H.pylori 菌株在系统发育树中具

  2. Expansion of CAG triplet repeats by human DNA polymerases λ and β in vitro, is regulated by flap endonuclease 1 and DNA ligase 1.

    Science.gov (United States)

    Crespan, Emmanuele; Hübscher, Ulrich; Maga, Giovanni

    2015-05-01

    Huntington's disease (HD) is a neurological genetic disorder caused by the expansion of the CAG trinucleotide repeats (TNR) in the N-terminal region of coding sequence of the Huntingtin's (HTT) gene. This results in the addition of a poly-glutamine tract within the Huntingtin protein, resulting in its pathological form. The mechanism by which TRN expansion takes place is not yet fully understood. We have recently shown that DNA polymerase (Pol) β can promote the microhomology-mediated end joining and triplet expansion of a substrate mimicking a double strand break in the TNR region of the HTT gene. Here we show that TNR expansion is dependent on the structure of the DNA substrate, as well as on the two essential Pol β co-factors: flap endonuclease 1 (Fen1) and DNA ligase 1 (Lig1). We found that Fen1 significantly stimulated TNR expansion by Pol β, but not by the related enzyme Pol λ, and subsequent ligation of the DNA products by Lig1. Interestingly, the deletion of N-terminal domains of Pol λ, resulted in an enzyme which displayed properties more similar to Pol β, suggesting a possible evolutionary mechanism. These results may suggest a novel mechanism for somatic TNR expansion in HD.

  3. Oxidized dNTPs and the OGG1 and MUTYH DNA glycosylases combine to induce CAG/CTG repeat instability

    Science.gov (United States)

    Cilli, Piera; Ventura, Ilenia; Minoprio, Anna; Meccia, Ettore; Martire, Alberto; Wilson, Samuel H.; Bignami, Margherita; Mazzei, Filomena

    2016-01-01

    DNA trinucleotide repeat (TNR) expansion underlies several neurodegenerative disorders including Huntington's disease (HD). Accumulation of oxidized DNA bases and their inefficient processing by base excision repair (BER) are among the factors suggested to contribute to TNR expansion. In this study, we have examined whether oxidation of the purine dNTPs in the dNTP pool provides a source of DNA damage that promotes TNR expansion. We demonstrate that during BER of 8-oxoguanine (8-oxodG) in TNR sequences, DNA polymerase β (POL β) can incorporate 8-oxodGMP with the formation of 8-oxodG:C and 8-oxodG:A mispairs. Their processing by the OGG1 and MUTYH DNA glycosylases generates closely spaced incisions on opposite DNA strands that are permissive for TNR expansion. Evidence in HD model R6/2 mice indicates that these DNA glycosylases are present in brain areas affected by neurodegeneration. Consistent with prevailing oxidative stress, the same brain areas contained increased DNA 8-oxodG levels and expression of the p53-inducible ribonucleotide reductase. Our in vitro and in vivo data support a model where an oxidized dNTPs pool together with aberrant BER processing contribute to TNR expansion in non-replicating cells. PMID:26980281

  4. The CAG polimorphic repeat within the androgen receptor gent and prostate diseases%雄激素受体基因(CAG)重复序列长度多态性与前列腺疾病

    Institute of Scientific and Technical Information of China (English)

    魏征; 席志军; 张志文

    2001-01-01

    雄激素受体基因中的CAG*重复序列长度的多态性,与前列腺疾病的发病率密切相关,有可能成为有效的危险判定因子.本文试图对这方面的进展作一简要介绍.

  5. Androgen insensitivity syndrome: do trinucleotide repeats in androgen receptor gene have any role?

    Institute of Scientific and Technical Information of China (English)

    Singh Rajender; Nalini J. Gupta; Baidyanath Chakravarty; Lalji Singh; Kumarasamy Thangaraj

    2008-01-01

    Aim: To investigate the role of CAG and GGN repeats as genetic background affecting androgen insensitivity syn- drome (AIS) phenotype. Methods: We analyzed lengths of androgen receptor (AR)-CAG and GGN repeats in 69 AIS cases, along with 136 unrelated normal male individuals. The lengths of repeats were analyzed using polymerase chain reaction (PCR) amplification followed by allelic genotyping to determine allele length. Results: Our study revealed significantly shorter mean lengths of CAG repeats in patients (mean 18.25 repeats, range 14-26 repeats) in comparison to the controls (mean 22.57 repeats, range 12-39 repeats) (two-tailed P < 0.0001). GGN repeats, however, did not differ significantly between patients (mean 21.48 repeats) and controls (mean 21.21 repeats) (two- tailed P = 0.474). Among patients' groups, the mean number of CAG repeats in partial androgen insensitivity cases (mean 15.83 repeats) was significantly less than in complete androgen insensitivity cases (mean 19.46 repeats) (two- tailed P < 0.0001). Conclusion: The findings suggest that shorter lengths of repeats in the AR gene might act as low penetrance genetic background in varying manifestation of androgen insensitivity. (Asian J Androl 2008 Jul; 10: 616-624)

  6. Short QTc Interval in Males with Klinefelter Syndrome-Influence of CAG Repeat Length, Body Composition, and Testosterone Replacement Therapy

    DEFF Research Database (Denmark)

    Jørgensen, Inger Norlyk; Skakkebaek, Anne; Andersen, Niels Holmark;

    2015-01-01

    BackgroundKlinefelter syndrome (KS) is a sex chromosomal aneuploidy (47,XXY) affecting 1/660 males. Based on findings in Turner syndrome, we hypothesized that electrocardiogram (ECG) abnormalities would be present in males with KS. ObjectiveTo investigate ECGs in males with KS and compare...... syndrome was determined in participants with a QTc ... interval comparable to controls. No mutations in genes related to short QT syndrome were found. ConclusionWe found short QTc interval in males with KS, with further shortening of the QTc interval by T. These results suggest that genes on the X chromosome could be involved in regulation of the QTc interval...

  7. Severe and rapidly progressing cognitive phenotype in a SCA17-family with only marginally expanded CAG/CAA repeats in the TATA-box binding protein gene: A case report

    Directory of Open Access Journals (Sweden)

    Nielsen Troels

    2012-08-01

    Full Text Available Abstract Background The autosomal dominant spinocerebellar ataxias (SCAs confine a group of rare and heterogeneous disorders, which present with progressive ataxia and numerous other features e.g. peripheral neuropathy, macular degeneration and cognitive impairment, and a subset of these disorders is caused by CAG-repeat expansions in their respective genes. The diagnosing of the SCAs is often difficult due to the phenotypic overlap among several of the subtypes and with other neurodegenerative disorders e.g. Huntington’s disease. Case presentation We report a family in which the proband had rapidly progressing cognitive decline and only subtle cerebellar symptoms from age 42. Sequencing of the TATA-box binding protein gene revealed a modest elongation of the CAG/CAA-repeat of only two repeats above the non-pathogenic threshold of 41, confirming a diagnosis of SCA17. Normally, repeats within this range show reduced penetrance and result in a milder disease course with slower progression and later age of onset. Thus, this case presented with an unusual phenotype. Conclusions The current case highlights the diagnostic challenge of neurodegenerative disorders and the need for a thorough clinical and paraclinical examination of patients presenting with rapid cognitive decline to make a precise diagnosis on which further genetic counseling and initiation of treatment modalities can be based.

  8. Strategy To Characterize the Number and Type of Repeating EPIYA Phosphorylation Motifs in the Carboxyl Terminus of CagA Protein in Helicobacter pylori Clinical Isolates▿ †

    OpenAIRE

    Panayotopoulou, Effrosini G.; Sgouras, Dionyssios N.; Papadakos, Konstantinos; Kalliaropoulos, Antonios; Papatheodoridis, George; Mentis, Andreas F; Archimandritis, Athanasios J

    2006-01-01

    Cytotoxin-associated gene A (CagA) diversity with regard to EPIYA-A, -B, -C, or -D phosphorylation motifs may play an important role in Helicobacter pylori pathogenesis, and therefore determination of these motifs in H. pylori clinical isolates can become a useful prognostic tool. We propose a strategy for the accurate determination of CagA EPIYA motifs in clinical strains, based upon one-step PCR amplification using primers that flank the EPIYA coding region. We thus analyzed 135 H. pylori i...

  9. Progress study on the mechanism of CAG repeats dynamic mutation in polyQ disease%多聚谷氨酰胺病CAG重复序列动态突变机制研究进展

    Institute of Scientific and Technical Information of China (English)

    王春荣; 江泓

    2012-01-01

    多聚谷氨酰胺病是一类中枢神经系统退行性疾病.由致病基因外显子内胞嘧啶-腺嘌呤-鸟嘌呤(CAG)三核苷酸重复序列拷贝数异常扩增导致其编码的多聚谷氨酰胺链异常延长,引起多聚谷氨酰胺扩展突变蛋白积聚而致病.迄今为止,共发现9种因多聚谷氨酰胺扩展突变型蛋白积聚引起的遗传性神经退行性疾病.CAG重复序列在代间传递过程中发生动态突变(拷贝数不断扩增),进而导致发病年龄提前和疾病严重程度增加.%Polyglutamine (polyQ) disease is a group of neurodegenerative disorders caused by abnormal expansion of CAG repeats within coding regions of certain causative genes, which are translated into a series of abnormally expanded polyQ tracts causing cytotoxicity. So far, nine diseases caused by expanded polyQ tracts have been demonstrated including Huntington's disease (HD), spinobulbar muscular atrophy (SBMA), dentatorubral-pallidoluysian atrophy (DRPLA) and several spinocerebellar ataxias subtypes (SCA). In human, long CAG repeats tend to expand during transmissions from parent to offspring, named as dynamic mutation, leading to an earlier age of disease onset and more severe symptoms in subsequent generations. The review presents some novel mechanisms based on dynamic mutation.

  10. Electrostatic effect of H1-histone protein binding on nucleosome repeat length

    Science.gov (United States)

    Cherstvy, Andrey G.; Teif, Vladimir B.

    2014-08-01

    Within a simple biophysical model we describe the effect of electrostatic binding of H1 histone proteins on the nucleosome repeat length in chromatin. The length of wrapped DNA optimizes its binding energy to the histone core and the elastic energy penalty of DNA wrapping. The magnitude of the effect predicted from our model is in agreement with the systematic experimental data on the linear variation of nucleosome repeat lengths with H1/nucleosome ratio (Woodcock C L et al 2006 Chromos. Res. 14 17-25). We compare our model to the data for different cell types and organisms, with a widely varying ratio of bound H1 histones per nucleosome. We underline the importance of this non-specific histone-DNA charge-balance mechanism in regulating the positioning of nucleosomes and the degree of compaction of chromatin fibers in eukaryotic cells.

  11. Read length and repeat resolution: Exploring prokaryote genomes using next-generation sequencing technologies

    KAUST Repository

    Cahill, Matt J.

    2010-07-12

    Background: There are a growing number of next-generation sequencing technologies. At present, the most cost-effective options also produce the shortest reads. However, even for prokaryotes, there is uncertainty concerning the utility of these technologies for the de novo assembly of complete genomes. This reflects an expectation that short reads will be unable to resolve small, but presumably abundant, repeats. Methodology/Principal Findings: Using a simple model of repeat assembly, we develop and test a technique that, for any read length, can estimate the occurrence of unresolvable repeats in a genome, and thus predict the number of gaps that would need to be closed to produce a complete sequence. We apply this technique to 818 prokaryote genome sequences. This provides a quantitative assessment of the relative performance of various lengths. Notably, unpaired reads of only 150nt can reconstruct approximately 50% of the analysed genomes with fewer than 96 repeat-induced gaps. Nonetheless, there is considerable variation amongst prokaryotes. Some genomes can be assembled to near contiguity using very short reads while others require much longer reads. Conclusions: Given the diversity of prokaryote genomes, a sequencing strategy should be tailored to the organism under study. Our results will provide researchers with a practical resource to guide the selection of the appropriate read length. 2010 Cahill et al.

  12. Read length and repeat resolution: exploring prokaryote genomes using next-generation sequencing technologies.

    Directory of Open Access Journals (Sweden)

    Matt J Cahill

    Full Text Available BACKGROUND: There are a growing number of next-generation sequencing technologies. At present, the most cost-effective options also produce the shortest reads. However, even for prokaryotes, there is uncertainty concerning the utility of these technologies for the de novo assembly of complete genomes. This reflects an expectation that short reads will be unable to resolve small, but presumably abundant, repeats. METHODOLOGY/PRINCIPAL FINDINGS: Using a simple model of repeat assembly, we develop and test a technique that, for any read length, can estimate the occurrence of unresolvable repeats in a genome, and thus predict the number of gaps that would need to be closed to produce a complete sequence. We apply this technique to 818 prokaryote genome sequences. This provides a quantitative assessment of the relative performance of various lengths. Notably, unpaired reads of only 150nt can reconstruct approximately 50% of the analysed genomes with fewer than 96 repeat-induced gaps. Nonetheless, there is considerable variation amongst prokaryotes. Some genomes can be assembled to near contiguity using very short reads while others require much longer reads. CONCLUSIONS: Given the diversity of prokaryote genomes, a sequencing strategy should be tailored to the organism under study. Our results will provide researchers with a practical resource to guide the selection of the appropriate read length.

  13. RUNX2 tandem repeats and the evolution of facial length in placental mammals

    Directory of Open Access Journals (Sweden)

    Pointer Marie A

    2012-06-01

    Full Text Available Abstract Background When simple sequence repeats are integrated into functional genes, they can potentially act as evolutionary ‘tuning knobs’, supplying abundant genetic variation with minimal risk of pleiotropic deleterious effects. The genetic basis of variation in facial shape and length represents a possible example of this phenomenon. Runt-related transcription factor 2 (RUNX2, which is involved in osteoblast differentiation, contains a functionally-important tandem repeat of glutamine and alanine amino acids. The ratio of glutamines to alanines (the QA ratio in this protein seemingly influences the regulation of bone development. Notably, in domestic breeds of dog, and in carnivorans in general, the ratio of glutamines to alanines is strongly correlated with facial length. Results In this study we examine whether this correlation holds true across placental mammals, particularly those mammals for which facial length is highly variable and related to adaptive behavior and lifestyle (e.g., primates, afrotherians, xenarthrans. We obtained relative facial length measurements and RUNX2 sequences for 41 mammalian species representing 12 orders. Using both a phylogenetic generalized least squares model and a recently-developed Bayesian comparative method, we tested for a correlation between genetic and morphometric data while controlling for phylogeny, evolutionary rates, and divergence times. Non-carnivoran taxa generally had substantially lower glutamine-alanine ratios than carnivorans (primates and xenarthrans with means of 1.34 and 1.25, respectively, compared to a mean of 3.1 for carnivorans, and we found no correlation between RUNX2 sequence and face length across placental mammals. Conclusions Results of our diverse comparative phylogenetic analyses indicate that QA ratio does not consistently correlate with face length across the 41 mammalian taxa considered. Thus, although RUNX2 might function as a ‘tuning knob’ modifying face

  14. Clinical characteristics of Huntington disease in two pedigrees and analysis of expanded CAG trinucleotide repeat%2个Huntington病家系临床特征及CAG重复性分析

    Institute of Scientific and Technical Information of China (English)

    曹广娜; 包新华; 卢红梅; 张晶晶; 马一楠; 顾卫红; 熊晖; 秦炯; 吴希如

    2011-01-01

    目的:探讨Huntington病(Huntington disease,HD)的临床和遗传特征.方法:对收集的2个中国汉族HD家系患者的临床资料进行综合分析,应用聚合酶链式反应及基因扫描方法对其中9例家系成员的IT15基因的三核苷酸重复序列进行分析.结果:在两个家系中确诊了6例患者(男女均有发病),患者IT15基因的基因型均为杂合子,致病CAG重复拷贝数介于40~78次.两个家系中子代较父代发病年龄提前,家系2中可见发病年龄与CAG重复拷贝数呈负相关.6例患者中有1例为少年型HD,其临床表现明显不同于成人型,以肌张力障碍为主要表现.结论:HD是一种由CAG重复序列异常扩增所致的神经变性病,存在遗传早现现象;少年型HD的临床表现不同于成人型,CAG重复拷贝数与发病年龄及疾病严重程度有关.%Objective: To understand the clinical and genetic features of Huntington disease ( HD) . Methods: The clinical data of HD cases from 2 Chinese families were analyzed and trinucleotide repeat in the IT15 gene were investigated in 9 of the two families by polymerase chain reaction and GeneScan. Results : Among the two pedigrees, 6 cases were ascertained as HD by genetic test. Genotypes of IT15 were heterozygous in these HD patients. CAG repeat of the patients in the HD chromosome were 40 -78. In the two pedigrees, the onset age was earlier in the subsequent generations than that of their fathers. In pedigree 2, the onset age was inversely correlated with CAG repeat number. One out of the 6 cases was juvenile-onset type of Huntington disease, whose clinical symptoms were different from those of the adultonset cases, especially the hypertonic manifestation. Conclusion: HD is an autosomal dominant neurodegenerative disorder with genetic anticipation caused by enlargement of CAG repeat in IT15 gene. The clinical manifestation is different between the juvenile-onset and the adult-onset. The number of CAG repeat is inversely

  15. PolyQ repeat expansions in ATXN2 associated with ALS are CAA interrupted repeats.

    Directory of Open Access Journals (Sweden)

    Zhenming Yu

    Full Text Available Amyotrophic lateral sclerosis (ALS is a devastating, rapidly progressive disease leading to paralysis and death. Recently, intermediate length polyglutamine (polyQ repeats of 27-33 in ATAXIN-2 (ATXN2, encoding the ATXN2 protein, were found to increase risk for ALS. In ATXN2, polyQ expansions of ≥ 34, which are pure CAG repeat expansions, cause spinocerebellar ataxia type 2. However, similar length expansions that are interrupted with other codons, can present atypically with parkinsonism, suggesting that configuration of the repeat sequence plays an important role in disease manifestation in ATXN2 polyQ expansion diseases. Here we determined whether the expansions in ATXN2 associated with ALS were pure or interrupted CAG repeats, and defined single nucleotide polymorphisms (SNPs rs695871 and rs695872 in exon 1 of the gene, to assess haplotype association. We found that the expanded repeat alleles of 40 ALS patients and 9 long-repeat length controls were all interrupted, bearing 1-3 CAA codons within the CAG repeat. 21/21 expanded ALS chromosomes with 3CAA interruptions arose from one haplotype (GT, while 18/19 expanded ALS chromosomes with <3CAA interruptions arose from a different haplotype (CC. Moreover, age of disease onset was significantly earlier in patients bearing 3 interruptions vs fewer, and was distinct between haplotypes. These results indicate that CAG repeat expansions in ATXN2 associated with ALS are uniformly interrupted repeats and that the nature of the repeat sequence and haplotype, as well as length of polyQ repeat, may play a role in the neurological effect conferred by expansions in ATXN2.

  16. Sequence analysis of trinucleotide repeat microsatellites from an enrichment library of the equine genome.

    Science.gov (United States)

    Tozaki, T; Inoue, S; Mashima, S; Ohta, M; Miura, N; Tomita, M

    2000-04-01

    Microsatellites are useful tools for the construction of a linkage map and parentage testing of equines, but only a limited number of equine microsatellites have been elucidated. Thus, we constructed the equine genomic library enriched for DNA fragments containing (CAG)n repeats. The enriched method includes hybridization-capture of repeat regions using biotin-conjugated oligonucleotides, nucleotide substrate-biased polymerase reaction with the oligonucleotides and subsequent PCR amplification, because these procedures are useful for the cloning of less abundant trinucleotide microsatellites. Microsatellites containing (CAG)n repeats were obtained at the ratio of one per 3-4 clones, indicating an enrichment value about 10(4)-fold, resulting in less time consumption and less cost for cloning. In this study, 66 different microsatellites, (CAG)n repeats, were identified. The number of complete simple CAG repeats in our clones ranged 4-33, with an average repeat length of 8.8 units. The microsatellites were useful as sequence-tagged site (STS) markers. In addition, some clones containing (CAG)n repeats showed homology to human (CAG)n-containing genes, which have been previously mapped. These results indicate that the clones might be a useful tool for chromosome comparison between equines and humans.

  17. Stoichiometry of base excision repair proteins correlates with increased somatic CAG instability in striatum over cerebellum in Huntington's disease transgenic mice.

    Science.gov (United States)

    Goula, Agathi-Vassiliki; Berquist, Brian R; Wilson, David M; Wheeler, Vanessa C; Trottier, Yvon; Merienne, Karine

    2009-12-01

    Huntington's disease (HD) is a progressive neurodegenerative disorder caused by expansion of an unstable CAG repeat in the coding sequence of the Huntingtin (HTT) gene. Instability affects both germline and somatic cells. Somatic instability increases with age and is tissue-specific. In particular, the CAG repeat sequence in the striatum, the brain region that preferentially degenerates in HD, is highly unstable, whereas it is rather stable in the disease-spared cerebellum. The mechanisms underlying the age-dependence and tissue-specificity of somatic CAG instability remain obscure. Recent studies have suggested that DNA oxidation and OGG1, a glycosylase involved in the repair of 8-oxoguanine lesions, contribute to this process. We show that in HD mice oxidative DNA damage abnormally accumulates at CAG repeats in a length-dependent, but age- and tissue-independent manner, indicating that oxidative DNA damage alone is not sufficient to trigger somatic instability. Protein levels and activities of major base excision repair (BER) enzymes were compared between striatum and cerebellum of HD mice. Strikingly, 5'-flap endonuclease activity was much lower in the striatum than in the cerebellum of HD mice. Accordingly, Flap Endonuclease-1 (FEN1), the main enzyme responsible for 5'-flap endonuclease activity, and the BER cofactor HMGB1, both of which participate in long-patch BER (LP-BER), were also significantly lower in the striatum compared to the cerebellum. Finally, chromatin immunoprecipitation experiments revealed that POLbeta was specifically enriched at CAG expansions in the striatum, but not in the cerebellum of HD mice. These in vivo data fit a model in which POLbeta strand displacement activity during LP-BER promotes the formation of stable 5'-flap structures at CAG repeats representing pre-expanded intermediate structures, which are not efficiently removed when FEN1 activity is constitutively low. We propose that the stoichiometry of BER enzymes is one critical

  18. Stoichiometry of base excision repair proteins correlates with increased somatic CAG instability in striatum over cerebellum in Huntington's disease transgenic mice.

    Directory of Open Access Journals (Sweden)

    Agathi-Vassiliki Goula

    2009-12-01

    Full Text Available Huntington's disease (HD is a progressive neurodegenerative disorder caused by expansion of an unstable CAG repeat in the coding sequence of the Huntingtin (HTT gene. Instability affects both germline and somatic cells. Somatic instability increases with age and is tissue-specific. In particular, the CAG repeat sequence in the striatum, the brain region that preferentially degenerates in HD, is highly unstable, whereas it is rather stable in the disease-spared cerebellum. The mechanisms underlying the age-dependence and tissue-specificity of somatic CAG instability remain obscure. Recent studies have suggested that DNA oxidation and OGG1, a glycosylase involved in the repair of 8-oxoguanine lesions, contribute to this process. We show that in HD mice oxidative DNA damage abnormally accumulates at CAG repeats in a length-dependent, but age- and tissue-independent manner, indicating that oxidative DNA damage alone is not sufficient to trigger somatic instability. Protein levels and activities of major base excision repair (BER enzymes were compared between striatum and cerebellum of HD mice. Strikingly, 5'-flap endonuclease activity was much lower in the striatum than in the cerebellum of HD mice. Accordingly, Flap Endonuclease-1 (FEN1, the main enzyme responsible for 5'-flap endonuclease activity, and the BER cofactor HMGB1, both of which participate in long-patch BER (LP-BER, were also significantly lower in the striatum compared to the cerebellum. Finally, chromatin immunoprecipitation experiments revealed that POLbeta was specifically enriched at CAG expansions in the striatum, but not in the cerebellum of HD mice. These in vivo data fit a model in which POLbeta strand displacement activity during LP-BER promotes the formation of stable 5'-flap structures at CAG repeats representing pre-expanded intermediate structures, which are not efficiently removed when FEN1 activity is constitutively low. We propose that the stoichiometry of BER enzymes

  19. Variability and repeatability in gestation length related to litter performance in female pigs on commercial farms.

    Science.gov (United States)

    Sasaki, Y; Koketsu, Y

    2007-07-15

    Forecasting gestation length (GL) in sows enables producers to be prepared to provide assistance at farrowing, or for timely treatment to induce parturition. The objectives of the present study were to determine GL across parities, the repeatability and correlation of the GL, and associations of GL with the three litter size variables (total pigs born, pigs born alive, and dead piglets) and longevity. This study was conducted on 94 farms and encompassed 66,254 farrowing records of 13,715 sows born during 1999. Variance components and correlation analyses were used to determine the repeatability and the correlations of GL. Mixed-effects models were used to analyze associations of GL with litter size variables and longevity. The mean of GL across parities was from 115.2 to 115.4 d. The proportions of GL 114, 115, and 116 d for all farrowing events were 19.2, 30.8, and 22.2%, respectively. The GL between parities were correlated (0.40/=117 d (P<0.01). Sows with GL

  20. Biological activity of the virulence factor cagA of Helicobacter pylori

    Institute of Scientific and Technical Information of China (English)

    朱永良; 郑树; 钱可大; 方平楚

    2004-01-01

    Background China is one of the countries with the highest incidence of H. Pylori and more than 9090 isolates possessed the cagA gene. This study was to evaluate the biological activity of the H.pylori virulence factor cagA isolated from Chinese patients. Methods cagA DNA fragments were amplified from the genomic DNA and subsequently cloned into the mammalian expression vector for cell transfection and DNA sequencing. cagA protein, phosphorylated-tyrosine cagA and the complex of cagA precipitated with SHP-2 were identified respectively by western blot in the crude cell lysate from conditionally immortalized gastric epithelial cells at 48 hours after transfection with cagA DNA. In addition, the ability of induction of scattering phenotype was examined after transient expression of cagA in AGS cells. Results The C-terminal half of cagA contained only one repeated sequence and three tandem five-amino-acid motifs glutamic acid-proline-isoleucine-tyrosine-alanine (EPIYA). Moreover, the amino acid sequence of D2 region in repeated sequence was aspartic acid-phenylanaline-aspartic acid (D-F-D) which was significantly distinguished from the three repeated sequences and aspartic acid-aspartic adid-leucine (D-D-L) in the western standard strain NCTC11637. Western blot revealed that cagA became phosphorylated in tyrosine site and bound with SHP-2 after transient expression of cagA DNA in gastric epithelial cells. Transient expression of cagA in AGS cells showed that cagA was able to induce the elongation phenotype although to a lesser extent than western strains. Conclusions cagA perturbs cell signaling pathways by binding with SHP-2. However, significant difference exists in amino acid sequence and biological function of cagA in Chinese compared with those of western countries.

  1. Recombination frequency in plasmid DNA containing direct repeats--predictive correlation with repeat and intervening sequence length.

    Science.gov (United States)

    Oliveira, Pedro H; Lemos, Francisco; Monteiro, Gabriel A; Prazeres, Duarte M F

    2008-09-01

    In this study, a simple non-linear mathematical function is proposed to accurately predict recombination frequencies in bacterial plasmid DNA harbouring directly repeated sequences. The mathematical function, which was developed on the basis of published data on deletion-formation in multicopy plasmids containing direct-repeats (14-856 bp) and intervening sequences (0-3872 bp), also accounts for the strain genotype in terms of its recA function. A bootstrap resampling technique was used to estimate confidence intervals for the correlation parameters. More than 92% of the predicted values were found to be within a pre-established +/-5-fold interval of deviation from experimental data. The correlation does not only provide a way to predict, with good accuracy, the recombination frequency, but also opens the way to improve insight into these processes.

  2. Methylation of HpaII and HhaI sites near the polymorphic CAG repeat in the human androgen-receptor gene correlates with X chromosome inactivation

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.C.; Zoghbi, H.Y.; Moseley, A.B.; Rosenblatt, H.M.; Belmont, J.W. (Baylor College of Medicine, Houston (United States))

    1992-12-01

    The human androgen-receptor gene (HUMARA; GenBank) contains a highly polymorphic trinucleotide repeat in the first exon. The authors have found that the methylation of HpaII and HhaI sites less than 100 pb away from this polymorphic short tandem repeat (STR) correlates with X inactivation. The close proximity of the restriction-enzyme sites to the STR allows the development of a PCR assay that distinguishes between the maternal and paternal alleles and identifies their methylation status. The accuracy of this assay was tested on (a) DNA from hamster/human hybrid cell lines containing either an active or inactive human X chromosome; (b) DNA from normal males and females; and (c) DNA from females showing nonrandom patterns of X inactivation. Data obtained using this assay correlated substantially with those obtained using the PGK, HPRT, and M27[beta] probes, which detect X inactivation patterns by Southern blot analysis. In order to demonstrate one application of this assay, the authors examined X inactivation patterns in the B lymphocytes of potential and obligate carriers of X-linked agammaglobulinemia. 42 refs., 5 figs., 1 tab.

  3. Repeat length variation in the dopamine D4 receptor gene shows no evidence of association with schizophrenia

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, J.; Williams, J.; Asherson, P. [Univ. of Wales College of Medicine, Cardiff (United Kingdom)] [and others

    1994-09-15

    The D4 receptor has been shown to exist in several allelic forms reflecting variation in the number of 48 base-pair sequence repeats in the putative cytoplasmic loop. We report a comparison of repeat length variation between schizophrenic patients and controls. Our sample of 106 unrelated schizophrenic cases and 119 controls showed no significant differences in allele or genotype distribution between patients and controls. In particular, we were unable to support the previous observation of an excess of 4-repeat homozygotes in patients. 16 refs., 2 tabs.

  4. Molecular characterization and polyclonal antibody generation against core component CagX protein of Helicobacter pylori type IV secretion system

    Science.gov (United States)

    Gopal, Gopal Jee; Kumar, Awanish; Pal, Jagannath; Mukhopadhyay, Gauranga

    2014-01-01

    Gram-negative bacteria Helicobacter pylori cause gastric ulcer, duodenal cancer, and found in almost half of the world’s residents. The protein responsible for this disease is secreted through type IV secretion system (TFSS) of H. pylori. TFSS is encoded by 40-kb region of chromosomal DNA known as cag-pathogenicity island (PAI). TFSS comprises of three major components: cytoplasmic/inner membrane ATPase, transmembrane core-complex and outer membranous pilli, and associated subunits. Core complex consists of CagX, CagT, CagM, and Cag3(δ) proteins as per existing knowledge. In this study, we have characterized one of the important component of core-complex forming sub-unit protein, i.e., CagX. Complete ORF of CagX except signal peptide coding region was cloned and expressed in pET28a vector. Purification of CagX protein was performed, and polyclonal anti-sera against full-length recombinant CagX were raised in rabbit model. We obtained a very specific and high titer, CagX anti-sera that were utilized to characterize endogenous CagX. Surface localization of CagX was also seen by immunofluorescence microscopy. In short for the first time a full-length CagX was characterized, and we showed that CagX is the part of high molecular weight core complex, which is important for assembly and function of H. pylori TFSS. PMID:24637488

  5. Studies of an expanded trinucleotide repeat in transgenic mice

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, P.; Wang, S.; Merry, D. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1994-09-01

    Spinal and bulbar muscular atrophy (SBMA) is a progressive motor neuron disease caused by expansion of a trinucleotide repeat in the androgen receptor gene (AR{sup exp}). AR{sup exp} repeats expand further or contract in approximately 25% of transmissions. Analogous {open_quotes}dynamic mutations{close_quotes} have been reported in other expanded trinucleotide repeat disorders. We have been developing a mouse model of this disease using a transgenic approach. Expression of the SBMA AR was documented in transgenic mice with an inducible promoter. No phenotypic effects of transgene expression were observed. We have extended our previous results on stability of the expanded trinucleotide repeat in transgenic mice in two lines carrying AR{sup exp}. Tail DNA was amplified by PCR using primers spanning the repeat on 60 AR{sup exp} transgenic mice from four different transgenic lines. Migration of the PCR product through an acrylamide gel showed no change of the 45 CAG repeat length in any progeny. Similarly, PCR products from 23 normal repeat transgenics showed no change from the repeat length of the original construct. Unlike the disease allele in humans, the expanded repeat AR cDNA in transgenic mice showed no change in repeat length with transmission. The relative stability of CAG repeats seen in the transgenic mice may indicate either differences in the fidelity of replicative enzymes, or differences in error identification and repair between mice and humans. Integration site or structural properties of the transgene itself might also play a role.

  6. Efficacy Improvement of PCR Amplification of CAG Trinucleotide Repeats in the Coding Sequence of Spinocerebellar Ataxia Type II Gene%提高SCA2编码区CAG三核苷酸重复的PCR扩增效率

    Institute of Scientific and Technical Information of China (English)

    汤熙翔; 夏家辉

    2000-01-01

    To improve the efficacy of PCR amplification of CAG trinucleotide repeats in the coding sequence of spinocerebellar ataxia type II gene(69.2% G+C), hot-start PCR, base-replacement PCR, and the addition of enhancers(1%~12.5% DMSO , 1%~25% glycerol ,1%~12.5% formamide) were performed and compared with normal PCR . The results showed that hot-start PCR, base-replacement PCR and the addition of enhancers(1%~10% DMSO , 5%~20% glycerol , 1%~10% formamide) improved the amplification efficacy of the GC rich region. Gene diagnosis in 70 SCA pedgrees and 60 spontaneous SCA patients were also conducted.%以遗传性脊髓小脑共济失调II型基因(spinocerebellar ataxia type II gene SCA2)编码区内的CAG三核苷酸重复为研究对象(G+C含量为69.2%),比较了热启动PCR、碱基替代PCR、添加增效剂(1%~12.5%二甲亚砜、1%~25%甘油、1%~12.5%甲酰胺)与常规PCR的扩增效率,发现热启动PCR、碱基替代PCR及添加增效剂(1%~10%二甲亚砜、5%~20%甘油、1%~10%甲酰胺)能提高该GC富集区的扩增效率,并对70个SCA家系及60个散发SCA患者进行了SCA2的基因诊断。

  7. Transcription elongation and tissue-specific somatic CAG instability.

    Directory of Open Access Journals (Sweden)

    Agathi-Vasiliki Goula

    Full Text Available The expansion of CAG/CTG repeats is responsible for many diseases, including Huntington's disease (HD and myotonic dystrophy 1. CAG/CTG expansions are unstable in selective somatic tissues, which accelerates disease progression. The mechanisms underlying repeat instability are complex, and it remains unclear whether chromatin structure and/or transcription contribute to somatic CAG/CTG instability in vivo. To address these issues, we investigated the relationship between CAG instability, chromatin structure, and transcription at the HD locus using the R6/1 and R6/2 HD transgenic mouse lines. These mice express a similar transgene, albeit integrated at a different site, and recapitulate HD tissue-specific instability. We show that instability rates are increased in R6/2 tissues as compared to R6/1 matched-samples. High transgene expression levels and chromatin accessibility correlated with the increased CAG instability of R6/2 mice. Transgene mRNA and H3K4 trimethylation at the HD locus were increased, whereas H3K9 dimethylation was reduced in R6/2 tissues relative to R6/1 matched-tissues. However, the levels of transgene expression and these specific histone marks were similar in the striatum and cerebellum, two tissues showing very different CAG instability levels, irrespective of mouse line. Interestingly, the levels of elongating RNA Pol II at the HD locus, but not the initiating form of RNA Pol II, were tissue-specific and correlated with CAG instability levels. Similarly, H3K36 trimethylation, a mark associated with transcription elongation, was specifically increased at the HD locus in the striatum and not in the cerebellum. Together, our data support the view that transcription modulates somatic CAG instability in vivo. More specifically, our results suggest for the first time that transcription elongation is regulated in a tissue-dependent manner, contributing to tissue-selective CAG instability.

  8. (CAG)n·(CTG)n三核苷酸重复序列扩增及相关疾病机制研究进展%Advances in the studies of the expansion of (CAG) n· (CTG) n trinucleotide repeats and mecha-nisms underlying its related diseases

    Institute of Scientific and Technical Information of China (English)

    王希恒; 潘学峰; 李红权; 段斐

    2016-01-01

    The dynamic expansion of ( CAG) n· ( CTG) n trinucleotide repeat in certain human genes is tightly associated with the occurrences of neuromuscular degenerative diseases , including multiple types of Spinal-cerebellar Ataxias .The repeating numbers of the relating ( CAG) n· ( CTG) n trinucleotide repeats in normal individuals are lower than a threshold level , while such repeating numbers of the repeats are beyond the threshold in the affiliated genes in patients , leading to the penetrations of different disease symptoms that mainly involve the neuro-and muscular systems .This review summarizes the disease condi-tion and the pathological characteristics of the ( CAG) n· ( CTG) n repeat expansion-associated human disea-ses in China while discussing the possible molecular mechanisms underlying the ( CAG) n· ( CTG) n repeat expansion in vivo .%出现在基因内三核苷酸重复序列( CAG) n·( CTG) n的“动态”扩增与包括多型脊髓小脑共济失调在内的神经-肌肉系统退行性病变的发生密切有关。正常个体中,相关(CAG)n·(CTG)n三核苷酸重复序列的重复单元数目被限制在一定的阈值之下,而在患者的受累基因内,( CAG) n·( CTG) n的重复数则超出该阈值,并导致患者出现与神经和肌肉系统有关的疾病症候。本文总结归纳了与( CAG) n·( CTG) n重复扩增相关的疾病在国内的发病情况和相关疾病的病理特征,并分析讨论了( CAG) n·( CTG) n序列在患者体内出现扩增的可能分子机制。

  9. ATXN2 with intermediate-length CAG/CAA repeats does not seem to be a risk factor in hereditary spastic paraplegia

    DEFF Research Database (Denmark)

    Nielsen, Troels Tolstrup; Svenstrup, Kirsten; Budtz-Jørgensen, Esben

    2012-01-01

    Hereditary spastic paraplegia (HSP) confines a group of heterogeneous neurodegenerative disorders characterized by progressive spasticity and lower limb weakness. Age of onset is highly variable even in familial cases with known mutations suggesting that the disease is modulated by other yet...

  10. Targeting several CAG expansion diseases by a single antisense oligonucleotide.

    NARCIS (Netherlands)

    Evers, M.M.; Pepers, B.A.; Deutekom, J.C.T. van; Mulders, S.A.M.; Dunnen, J.T. den; Aartsma-Rus, A.; Ommen, G.J.B. van; Roon-Mom, W.M. van

    2011-01-01

    To date there are 9 known diseases caused by an expanded polyglutamine repeat, with the most prevalent being Huntington's disease. Huntington's disease is a progressive autosomal dominant neurodegenerative disorder for which currently no therapy is available. It is caused by a CAG repeat expansion i

  11. Role of androgen receptor CAG repeat polymorphism in pathogenesis of coronary artery disease in elderly men%雄激素受体基因CAG重复数多态性与老年男性冠心病的关系及可能机制

    Institute of Scientific and Technical Information of China (English)

    张秀锦; 李小鹰; 曹甜甜; 叶玲

    2013-01-01

    Objective To investigate the relationship of androgen receptor (AR) CAG repeat polymorphism and coronary artery disease (CAD) in elderly men and its potential mechanism.Methods Totally 296 elderly men undergoing coronary angiography were enrolled in this study.Serum total testosterone (TT) and free testosterone (FT) levels were measured.Androgen receptors (ARs) in peripheral lymphocytes were determined by flow cytometry.Genome DNA was extracted from peripheral leucocytes using standard techniques.Gene fragments containing AR CAG repeats were amplified by PCR with specific fluorescent labeled primers.PCR products were separated with agarose gels.CAG repeat number of each sample was obtained by genotyping.Results AR CAG repeats varied from 11 to 28 (P25-P75:18-22; median:20) in elderly male patients.They were divided into the long AR group (CAG repeats≥22,n=82) and the short AR group (CAG repeats<22,n=214).Compared with the long AR group,serum FT level was much lower in the short AR group [(24.1±23.1) ×10-6mmol/L vs.(31.2±27.8)×10-6mmol/L,P<0.05].The prevalence of coronary artery disease was higher in the short AR group than in the long AR group [84.1% (180 cases) vs.69.5%(57 cases),P<0.05].The FT level was lower in the short AR group combined with CAD than in the control group [(22.4±20.5) ×10-6mmol/L vs.(33.6±32.4)×10 6mmol/L,P<0.01].There were no significant differences in serum TT and AR levels between the long and short AR groups.No significant correlations were found in the AR CAG repeats polymorphism with FT,TT or AR levels.Age was the main risk factor for FT and AR levels.Logistic regression analysis showed that FT level was negatively correlated with CAD (OR=0.98,95 % CI:0.973-0.998,P=0.01),and short AR increased the risk of CAD in elderly male patients (OR=3.44,95%CI:1.887-6.264,P<0.01).Conclusions Serum FT level is correlated with age and is significantly decreased in elderly male patients with short AR repeats,which may

  12. 直接检测IT15基因(CAG)n重复对亨廷顿氏病进行基因诊断%Direct Detection of the Expanded CAG Repeat in IT15 Gene for Molecular Diagnosis of Huntington's Disease

    Institute of Scientific and Technical Information of China (English)

    毛跃华; 周刚; 陈美珏; 任兆瑞; 曾溢滔; 王秀英; 许志大

    1995-01-01

    应用巢式PCR和变性聚丙烯酰胺凝胶电泳放射自显影鉴定IT15基因(CAG)n串联重复序列拷贝数的技术,对40名正常中国人以及徐州和浙江两大亨廷顿氏病(HD病)家系46名家庭成员进行了分析.结果表明,正常中国人IT15基因(CAG)n拷贝数为16左右,而HD患者的突变基因(CAG)n拷贝数均大于40,两者之间不重叠.对38名HD病高风险者进行症状前分子诊断,揭示11名家庭成员为HD基因的携带者,与家系调查和临床分析的结果相吻合.本文结果不仅证明IT15基因的动态突变也是导致中国人HD病的遗传学基础,而且为HD病的基因诊断、遗传咨询和遗传保健提供了科学资料.

  13. A statistical approach designed for finding mathematically defined repeats in shotgun data and determining the length distribution of clone-inserts

    DEFF Research Database (Denmark)

    Zhong, Lan; Zhang, Kunlin; Huang, Xiangang

    2003-01-01

    The large amount of repeats, especially high copy repeats, in the genomes of higher animals and plants makes whole genome assembly (WGA) quite difficult. In order to solve this problem, we tried to identify repeats and mask them prior to assembly even at the stage of genome survey. It is known...... that repeats of different copy number have different probabilities of appearance in shotgun data, so based on this principle, we constructed a statistical model and inferred criteria for mathematically defined repeats (MDRs) at different shotgun coverages. According to these criteria, we developed software......-inserts using our model. In our simulated genomes of human and rice, the length distribution of repeats is different, so their optimal length distributions of clone-inserts were not the same. Thus with optimal length distribution of clone-inserts, a given genome could be assembled better at lower coverage...

  14. Murine protein H is comprised of 20 repeating units, 61 amino acids in length

    DEFF Research Database (Denmark)

    Kristensen, Torsten; Tack, B F

    1986-01-01

    A cDNA library constructed from size-selected (greater than 28 S) poly(A)+ RNA isolated from the livers of C57B10. WR mice was screened by using a 249-base-pair (bp) cDNA fragment encoding 83 amino acid residues of human protein H as a probe. Of 120,000 transformants screened, 30 hybridized...... with this cDNA probe. Ten positives were colony-purified, and the largest plasmid cDNA insert, MH8 (4.4 kb), was sequenced by the dideoxy chain termination method. MH8 contained the complete coding sequence for the precursor of murine complement protein factor H (3702 bp), 100 bp of 5'-untranslated sequence......, 448 bp of 3'-untranslated sequence, and a polyadenylylated tail of undetermined length. Murine pre-protein H was deduced to consist of an 18-amino acid signal peptide and 1216 residues of H-protein sequence. Murine H was composed of 20 repetitive units, each about 61 amino acid residues in length...

  15. 不同群体中ATXN2基因编码区CAG重复的变异研究%Variation of CAG repeats in coding region of ATXN2 gene in different ethnic groups

    Institute of Scientific and Technical Information of China (English)

    陈晓晨; 杨昭庆; 褚嘉祐; 孙浩; 米冬青; 黄小琴; 林克勤; 易文; 于亮; 史磊; 史荔

    2011-01-01

    在中国6个生活环境差异较大的少数民族群体中进行ATXN2基因编码区CAG重复的变异研究,以衡量其是否受到正选择的作用以及寻找推动选择作用的因素.采集6个民族群体共291个健康无关个体,对其进行STR分型,直接计数其等位基因及等位基因型频率,计算其线性Fst值,构建针对该基因的系统进化树,并对各群体进行MDS分析.线性Fst值结果显示:回族和彝族群体间ATXN2基因STR位点进化的差异具有显著性,其他4个群体相互间无显著性差异.结合已报道的其他群体进一步分析,回族、哈尼族、云南蒙古族以及内蒙古自治区蒙古族每个人群都与日本人群有显著性差异;回族、内蒙古自治区蒙古族与汉族具有显著性差异.6个群体中ATXN2基因STR的等位基因频率有各自的分布特点,稀有等位基因频率变化产生的原因可能是选择作用的结果.%Toinvestigate CAG repeats variation of ATXN2 gene coding region in six ethnic groups that live in comparatively different environments, to evaluate whether these variations are under positive selection, and to find factors driving selection effects, 291 unrelated healthy individuals were collected from six ethnic groups and their STR geneotyping was performed.The frequencies of alleles and genotypes were counted and thereby Slatkin's linearized Fst values were calculated.The UPGMA tree against this gene was constructed.The MDS analysis among these groups was carried out as well.The results from the linearized Fst values indicated that there were significant evolutionary differences of the STR in A TXN2 gene between Hui and Yi groups, but not among the other 4 groups.Further analysis was performed by combining our data with published data obtained from other groups.These results indicated that there were significant differences between Japanese and other groups including Hui, Hani, Yunnan Mongolian, and Inner Mongolian.Both Hui and Mongolian from

  16. Study on relationship between polymorphism of Har gene (CAG)n micro-satellite and prostate cancer

    Institute of Scientific and Technical Information of China (English)

    WANG Gang; WANG Xiao-hui; XIA Bing; CHEN Guang-chun; LU Jian

    2002-01-01

    Objective: To study the relationship between the polymorphic (CAG)n micro-satellite of human androgen receptor (bAR) gene and prostate cancer (Pca). Methods: The number of (CAG)n repeats in 107 normal males were measured by a two-step [α-32P]-dCTP incorporated asymmetric polymeric chain reaction (PCR), and the (CAG)n repeats of both malignant and nonmalignant prostate cells in fixed paraffin-embedded tissue (PET) specimen from 36 case of Pca were determined by sequence analysis. Results: The repeats of polymorphic (CAG) n among normal men ranged from 11 to 29, and the most frequent repeat was 22(18. 69%), with 23(14. 02%), 24(10. 28%) and 21(10. 28%) being less frequent. The (CAG)n repeats of malignant prostate cells equaled to that of nonmalignant adjacent prostate tissue cells from the same PET specimen in all 36 Pca, and the (CAG)n repeats in 36 Pca which ranged from 16 to 22 were shorter than that in normal males significantly (P<0. 05), while no significant difference in (CAG)n repeats among various grade of tumor's differentiation(well-differentiated, intermediate-differentiated and poor-differentiated) was found (P> 0. 05). Conclusion: The present study suggest that short hAR gene (CAG)n micro-satellite might be associated with the occurrence of Pca, but not with the differentiation of Pca.

  17. Psychiatric symptoms and CAG expansion in Huntington`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Weber, M.W.; Schmid, W.; Spiegel, R. [Univ. of Zuerich (Switzerland)

    1996-02-16

    The mutation responsible for Huntington`s disease (HD) is an elongated CAG repeat in the coding region of the IT15 gene. A PCR-based test with high sensitivity and accuracy is now available to identify asymptomatic gene carriers and patients. An inverse correlation between CAG copy number and age at disease onset has been found in a large number of affected individuals. The influence of the CAG repeat expansion on other phenotypic manifestations, especially specific psychiatric symptoms has not been studied intensively. In order to elucidate this situation we investigated the relation between CAG copy number and distinct psychiatric phenotypes found in 79 HD-patients. None of the four differentiated categories (personality change, psychosis, depression, and nonspecific alterations) showed significant differences in respect to size of the CAG expansion. In addition, no influence of individual sex on psychiatric presentation could be found. On the other hand in patients with personality changes maternal transmission was significantly more frequent compared with all other groups. Therefore we suggest that clinical severity of psychiatric features in HD is not directly dependent on the size of the dynamic mutation involved. The complex pathogenetic mechanisms leading to psychiatric alterations are still unknown and thus genotyping does not provide information about expected psychiatric symptoms in HD gene carriers. 40 refs., 1 fig., 2 tabs.

  18. Topological diversity of chromatin fibers: Interplay between nucleosome repeat length, DNA linking number and the level of transcription

    Directory of Open Access Journals (Sweden)

    Davood Norouzi

    2015-11-01

    Full Text Available The spatial organization of nucleosomes in 30-nm fibers remains unknown in detail. To tackle this problem, we analyzed all stereochemically possible configurations of two-start chromatin fibers with DNA linkers L = 10-70 bp (nucleosome repeat length NRL = 157-217 bp. In our model, the energy of a fiber is a sum of the elastic energy of the linker DNA, steric repulsion, electrostatics, and the H4 tail-acidic patch interaction between two stacked nucleosomes. We found two families of energetically feasible conformations of the fibers—one observed earlier, and the other novel. The fibers from the two families are characterized by different DNA linking numbers—that is, they are topologically different. Remarkably, the optimal geometry of a fiber and its topology depend on the linker length: the fibers with linkers L = 10n and 10n + 5 bp have DNA linking numbers per nucleosome DLk >>-1.5 and -1.0, respectively. In other words, the level of DNA supercoiling is directly related to the length of the inter-nucleosome linker in the chromatin fiber (and therefore, to NRL. We hypothesize that this topological polymorphism of chromatin fibers may play a role in the process of transcription, which is known to generate different levels of DNA supercoiling upstream and downstream from RNA polymerase. A genome-wide analysis of the NRL distribution in active and silent yeast genes yielded results consistent with this assumption.

  19. A Statistical Approach Designed for Finding Mathematically Defined Repeats in Shotgun Data and Determining the Length Distribution of Clone—Inserts

    Institute of Scientific and Technical Information of China (English)

    LanZhong; KunlinZhang; XiangangHuang; PeixiangNi; YujunHan; KaiWang; JunWang; SonggangLi

    2003-01-01

    The large amount of repeats,especially high copy repeats,in the genomes of higher animals and plants makes whole genome assembly(WGA)quite difficult.In order to solve this problem,we tried to identify repeats and mask them prior to assembly even at the stage of genome survey.It is known that repeats of different copy number have different probabilities of appearance in shotgun data,so based on this principle,we constructed a statistical model and inferred criteria for mathematically defined repeats(MDRs)at different shotgun coverages.According to these criteria,we developed software MDRmasker to identify and mask MDRs in shotgun data.With repeats masked prior to assembly,the speed of as sembly was increased with lower error probability.In addition,clone-insert size affects the accuracy of repeat assembly and scaffold construction.We also designed length distribution of clone-inserts using our model.In our simulated genomes of human and rice,the length distribution of repeats in different,so their optimal length distributions of clone-inserts were not the same.Thus with optimal length distribution of clone-inserts,a given genome could be assembled better at lower coverage.

  20. A Statistical Approach Designed for Finding Mathematically De fined Repeats in Shotgun Data and Determining the Length Distri bution of Clone-Inserts

    Institute of Scientific and Technical Information of China (English)

    Lan Zhong; Kunlin Zhang; Xiangang Huang; Peixiang Ni; Yujun Han; Kai Wang; Jun Wang; Songgang Li

    2003-01-01

    The large amount of repeats, especially high copy repeats, in the genomes of higher animals and plants makes whole genome assembly (WGA) quite difficult. In order to solve this problem, we tried to identify repeats and mask them prior to assembly even at the stage of genome survey. It is known that repeats of different copy number have different probabilities of appearance in shotgun data, so based on this principle, we constructed a statistical model and inferred criteria for mathematically defined repeats (MDRs) at different shotgun coverages. According to these criteria, we developed software MDRmasker to identify and mask MDRs in shotgun data. With repeats masked prior to assembly, the speed of assembly was increased with lower error probability. In addition, clone-insert size affects the accuracy of repeat assembly and scaffold construction. We also designed length distribution of clone-inserts using our model. In our simulated genomes of human and rice, the length distribution of repeats is different, so their optimal length distributions of clone-inserts were not the same. Thus with optimal length distribution of clone-inserts, a given genome could be assembled better at lower coverage.

  1. A novel PCR-based approach for the detection of the Huntington disease associated trinucleotide repeat expansion.

    Science.gov (United States)

    Panagopoulos, I; Lassen, C; Kristoffersson, U; Aman, P

    1999-01-01

    Huntington disease (HD) is an autosomal dominant neurodegenerative disorder associated with expansions of an unstable CAG trinucleotide repeat in exon 1 of the IT15 gene. In normal individuals, IT15 contains up to 35 CAG repeats, while in affected the repeat length is >36. Polymerase chain reaction (PCR) is used to estimate the number of CAG repeats but may be inefficient in long repeats because of the high C+G content of the HD locus. We present a novel PCR approach for the diagnosis of HD, which permits direct visualization of the amplified products on agarose gel, using ethidium bromide. It is based on the methylation-sensitive conversion of C residues to U by bisulfite treatment of single-stranded DNA and subsequent amplification of the sense strand with specific primers. The bisulfite treatment dramatically reduces the C + G content of the region; thus, the high Tm and stable secondary structures are no longer obstacles to PCR. In both normal and affected individuals, UAG repeats (5'- CAG-3', before bisulfite treatment) in the sense strand can easily be amplified and visualized on a gel by ethidium bromide staining. The method has considerable advantages compared with other described PCR-based diagnostic tests for HD.

  2. Molecular anslysis on the CAG trinucleotide repeat of Huntington's disease in Anhui people%安徽入亨廷顿病CAG三核苷酸重复的分子分析

    Institute of Scientific and Technical Information of China (English)

    孙国梅; 余元勋

    2000-01-01

    为在分子水平了解安徽人亨廷顿病(HD)的发病机制,为该病的基因诊断和遗传咨询提供科学依据.应用巢式PCR,变性聚丙烯酰胺凝胶电泳以及DNA测序等方法,对6例正常安徽人以及6例HD家系的研究结果表明:中国人正常IT15基因(CAG)n重复序列的拷贝数为13-26,而所有被分析的HD患者都携带一个CAG序列高度重复的IT15基因,其(CAG)n的拷贝数为40-94;且CAG重复序列的拷贝数与发病年龄呈现一定的相关性.

  3. Gene diagnosis and CAG repeat analysis of spinocerebellar ataxia cases of Guangxi region%广西地区脊髓小脑性共济失调病人的基因诊断和CAG重复扩增

    Institute of Scientific and Technical Information of China (English)

    谭建强; 袁志刚; 汪萍; 胡启平; 李松峰; 舒伟; 马军; 方玲; 华荣; 丁晔

    2009-01-01

    为探讨广西地区脊髓小脑性共济失调(Spinocerebellar ataxia,SCA)患者各种亚型类型特点及分布状况,应用聚合酶链反应(Polymerase chain reaction,PCR),毛细管电泳(Capillary electrophoresis,CE)片段分析等技术检测分析遗传性共济失调患者的SCA1、SCA2、SCA3/MJD、SCA6、SCA7和SCA12(CAG)n突变.在6个SCA家系共检出21例患者和19例症状前患者均为SCA3/MJD突变,CAG重复数分别为59~70次和60~73次.未检测到SCA1、SCA2、SCA6、SCA7和SCA12(CAG)n突变.研究表明,广西地区的SCA病人主要为SCA3/MJD型,患者的CAG重复数低于过去的报道.

  4. Size polymorphism of chicken major histocompatibility complex-encoded B-G molecules is due to length variation in the cytoplasmic heptad repeat region

    DEFF Research Database (Denmark)

    Kaufman, J; Salomonsen, J; Skjødt, K;

    1990-01-01

    that the extracellular regions of these molecules are very similar and that the length polymorphism is due to variations in the cytoplasmic regions. Inspection of the cDNA-derived protein sequence in this region shows many heptad repeats, which may allow variation in length by step deletion and alternative splicing...

  5. CagY Is an Immune-Sensitive Regulator of the Helicobacter pylori Type IV Secretion System.

    OpenAIRE

    Barrozo, RM; Hansen, LM; Lam, AM; Skoog, EC; Martin, ME; Cai, LP; Lin, Y; Latoscha, A; Suerbaum, S; Canfield, DR; Solnick, JV

    2016-01-01

    Peptic ulcer disease and gastric cancer are caused most often by Helicobacter pylori strains that harbor the cag pathogenicity island, which encodes a type IV secretion system (T4SS) that injects the CagA oncoprotein into host cells. cagY is an essential gene in the T4SS and has an unusual DNA repeat structure that predicts in-frame insertions and deletions. These cagY recombination events typically lead to a reduction in T4SS function in mouse and primate models. We examined the role of the ...

  6. Characterization of CagA variable region of Helicobacter pylori isolates from Chinese patients

    Institute of Scientific and Technical Information of China (English)

    Yong-Liang Zhu; Shu Zheng; Qin Du; Ke-Da Qian; Ping-Chu Fang

    2005-01-01

    AIM: To characterize the CagA variable region of Helicobacter pylori isolates from Chinese patients.METHODS: DNA fragments in CagA variable region were amplified and sequenced respectively from genomic DNA of 19 isolates from patients with gastric cancer and 20isolates from patients with chronic gastritis. The tendency of phosphorylation in tyrosine(s) of CagA proteins was evaluated subsequently by phosphorylation assay in vivo and in vitro respectively.RESULTS: About 97.44% (38/39) H pylori isolates possessed CagA gene. CagA+ strains contained 2-4tandem five-amino-acid motifs EPIYA but only one EPIYA had repeated sequence in CagA variable region in different isolates. There was no significant difference between the number of EPIYA motifs in H pylori from patients with different diseases. However, only tyrosine site in EPIYA within repeated sequence could be phosphorylated by AGS cells in vivo although all tyrosine sites in EPIYA could be phosphorylated in vitro.CONCLUSION: CagA in Chinese has no functional difference in perturbing cellular signal pathway among different H pylori isolates.

  7. Conformational analysis of isolated domains of Helicobacter pylori CagA.

    Directory of Open Access Journals (Sweden)

    Amanda P Woon

    Full Text Available The CagA protein of Helicobacter pylori is associated with increased virulence and gastric cancer risk. CagA is translocated into the host cell by a H. pylori type IV secretion system via mechanisms that are poorly understood. Translocated CagA interacts with numerous host factors, altering a variety of host signalling pathways. The recently determined crystal structure of C-terminally-truncated CagA indicated the presence of two domains: the smaller, flexible N-terminal domain and the larger, middle domain. In this study, we have investigated the conformation, oligomeric state and stability of the N-terminal, middle and glutamate-proline-isoleucine-tyrosine-alanine (EPIYA-repeats domains. All three domains are monomeric, suggesting that the multimerisation of CagA observed in infected cells is likely to be mediated not by CagA itself but by its interacting partners. The middle and the C-terminal domains, but not the N-terminal domain, are capable of refolding spontaneously upon heat denaturation, lending support to the hypothesis that unfolded CagA is threaded C-terminus first through the type IV secretion channel with its N-terminal domain, which likely requires interactions with other domains to refold, being threaded last. Our findings also revealed that the C-terminal EPIYA-repeats domain of CagA exists in an intrinsically disordered premolten globule state with regions in PPII conformation--a feature that is shared by many scaffold proteins that bind multiple protein components of signalling pathways. Taken together, these results provide a deeper understanding of the physicochemical properties of CagA that underpin its complex cellular and oncogenic functions.

  8. Tandem repeat sequence variation and length heteroplasmy in the mitochondrial DNA D-loop of the threatened Gulf of Mexico sturgeon, Acipenser oxyrhynchus desotoi.

    Science.gov (United States)

    Miracle, A L; Campton, D E

    1995-01-01

    Genetic variability within the Suwannee River, Florida, population of Gulf of Mexico sturgeon, Acipenser oxyrhynchus desotoi, was assessed by examining sequence and length variation within the control region, or D-loop, of the mitochondrial genome. Although once abundant throughout the Gulf of Mexico, Gulf sturgeon are now listed as a threatened species by the U.S. Fish and Wildlife Service. Mitochondrial DNA was analyzed for length variation from 168 individual Gulf sturgeon by PCR amplification and visualization of PCR products using ethidium bromide-stained agarose gels. Of the 168 individual Gulf sturgeon, 31 (18.5%) were heteroplasmic for one to four copies of an 81-base pair, tandemly repeated sequence in the D-loop region. However, no individuals homoplasmic for multiple copies of the repeat sequence were observed. The existence and nature of these tandem repeats in heteroplasmic individuals was confirmed by direct sequencing of the PCR products for a subset of 22 individuals. The results are consistent with the apparent nature and mechanism of heteroplasmy observed in a congeneric species, A. transmontanus. In addition, sequences for 187 base pairs outside of the tandem repeats were identical among all 16 individuals assayed for this region. Lack of variable sequences is concordant with earlier studies involving mtDNA restriction fragment length profiles of Gulf sturgeon found in the Suwannee River. The absence of sequence variation exclusive of the tandem repeats is consistent with the hypothesis that the subspecies has undergone a population or evolutionary bottleneck.

  9. Clustering of Beijing genotype Mycobacterium tuberculosis isolates from the Mekong delta in Vietnam on the basis of variable number of tandem repeat versus restriction fragment length polymorphism typing.

    NARCIS (Netherlands)

    Huyen, M.N.; Kremer, K.; Lan, N.T.; Buu, T.N.; Cobelens, F.G.; Tiemersma, E.W.; Haas, P. de; Soolingen, D. van

    2013-01-01

    BACKGROUND: In comparison to restriction fragment length polymorphism (RFLP) typing, variable number of tandem repeat (VNTR) typing is easier to perform, faster and yields results in a simple, numerical format. Therefore, this technique has gained recognition as the new international gold standard i

  10. Cloning, characterization, and properties of seven triplet repeat DNA sequences.

    Science.gov (United States)

    Ohshima, K; Kang, S; Larson, J E; Wells, R D

    1996-07-12

    Several neuromuscular and neurodegenerative diseases are caused by genetically unstable triplet repeat sequences (CTG.CAG, CGG.CCG, or AAG.CTT) in or near the responsible genes. We implemented novel cloning strategies with chemically synthesized oligonucleotides to clone seven of the triplet repeat sequences (GTA.TAC, GAT.ATC, GTT.AAC, CAC.GTG, AGG.CCT, TCG.CGA, and AAG.CTT), and the adjoining paper (Ohshima, K., Kang, S., Larson, J. E., and Wells, R. D.(1996) J. Biol. Chem. 271, 16784-16791) describes studies on TTA.TAA. This approach in conjunction with in vivo expansion studies in Escherichia coli enabled the preparation of at least 81 plasmids containing the repeat sequences with lengths of approximately 16 up to 158 triplets in both orientations with varying extents of polymorphisms. The inserts were characterized by DNA sequencing as well as DNA polymerase pausings, two-dimensional agarose gel electrophoresis, and chemical probe analyses to evaluate the capacity to adopt negative supercoil induced non-B DNA conformations. AAG.CTT and AGG.CCT form intramolecular triplexes, and the other five repeat sequences do not form any previously characterized non-B structures. However, long tracts of TCG.CGA showed strong inhibition of DNA synthesis at specific loci in the repeats as seen in the cases of CTG.CAG and CGG.CCG (Kang, S., Ohshima, K., Shimizu, M., Amirhaeri, S., and Wells, R. D.(1995) J. Biol. Chem. 270, 27014-27021). This work along with other studies (Wells, R. D.(1996) J. Biol. Chem. 271, 2875-2878) on CTG.CAG, CGG.CCG, and TTA.TAA makes available long inserts of all 10 triplet repeat sequences for a variety of physical, molecular biological, genetic, and medical investigations. A model to explain the reduction in mRNA abundance in Friedreich's ataxia based on intermolecular triplex formation is proposed.

  11. Evolution of cagA oncogene of Helicobacter pylori through recombination.

    Directory of Open Access Journals (Sweden)

    Yoshikazu Furuta

    Full Text Available Helicobacter pylori is a gastric pathogen that infects half the human population and causes gastritis, ulcers, and cancer. The cagA gene product is a major virulence factor associated with gastric cancer. It is injected into epithelial cells, undergoes phosphorylation by host cell kinases, and perturbs host signaling pathways. CagA is known for its geographical, structural, and functional diversity in the C-terminal half, where an EPIYA host-interacting motif is repeated. The Western version of CagA carries the EPIYA segment types A, B, and C, while the East Asian CagA carries types A, B, and D and shows higher virulence. Many structural variants such as duplications and deletions are reported. In this study, we gained insight into the relationships of CagA variants through various modes of recombination, by analyzing all known cagA variants at the DNA sequence level with the single nucleotide resolution. Processes that occurred were: (i homologous recombination between DNA sequences for CagA multimerization (CM sequence; (ii recombination between DNA sequences for the EPIYA motif; and (iii recombination between short similar DNA sequences. The left half of the EPIYA-D segment characteristic of East Asian CagA was derived from Western type EPIYA, with Amerind type EPIYA as the intermediate, through rearrangements of specific sequences within the gene. Adaptive amino acid changes were detected in the variable region as well as in the conserved region at sites to which no specific function has yet been assigned. Each showed a unique evolutionary distribution. These results clarify recombination-mediated routes of cagA evolution and provide a solid basis for a deeper understanding of its function in pathogenesis.

  12. Prognostic significance of telomeric repeat length alterations in pathological stage I-IIIA non-small cell lung cancer.

    Science.gov (United States)

    Hirashima, T; Komiya, T; Nitta, T; Takada, Y; Kobayashi, M; Masuda, N; Matui, K; Takada, M; Kikui, M; Yasumitu, T; Ohno, A; Nakagawa, K; Fukuoka, M; Kawase, I

    2000-01-01

    This study was performed to evaluate the prognostic significance of alteration in telomere length in pathological stage (p-stage) I-IIIA non-small cell lung cancer (NSCLC). Paired cancer and normal lung tissues were obtained from 72 patients with histologically confirmed p-stage I-IIIA NSCLC. Terminal restriction fragment (TRF) length, which indicates telomere length, was measured by Southern blot analysis. Tumor telomerase activity was also assayed by non-radioactive PCR-ELISA in 55 patients. TRF length (mean +/- SD) in normal tissue was 6.2 +/- 1.1 Kb. Therefore, upper and lower limits of normal range in TRF length was set at 8.4 (mean + 2SD) Kb and 4.0 (mean-2SD) Kb, respectively. A tumor showing TRF length over normal range was defined as positive for the alteration. In 72 patients, 25 (34.7%) with alteration in TRF length had significantly shorter survival durations than those of the others. Telomerase activity did not correlate with survival duration. In multivariate analysis, alteration in TRF length (P = 0.0033) was second to p-stage (P = 0.0004) in importance among the various parameters.

  13. Novel CagA ELISA exhibits enhanced sensitivity of Helicobacter pylori CagA antibody

    Science.gov (United States)

    Matsuo, Yuichi; Kido, Yasutoshi; Akada, Junko; Shiota, Seiji; Binh, Tran Thanh; Trang, Tran Thi Huyen; Dung, Ho D Q; Tung, Pham Huu; Tri, Tran Dinh; Thuan, Ngo P Minh; Tam, Le Quang; Nam, Bui Chi; Khien, Vu Van; Yamaoka, Yoshio

    2017-01-01

    AIM To develop a novel Helicobacter pylori (H. pylori) CagA antibody enzyme-linked immunosorbent assay (ELISA) suitable for detecting serum anti-CagA antibodies with high sensitivity. METHODS Recombinant East Asian-type CagA protein was purified and immobilized for ELISA. Serum samples from 217 Vietnamese individuals (110 H. pylori-infected and 107 uninfected individuals) were applied. Conventional ELISA from Western-type CagA and our East Asian-type CagA ELISA were evaluated by comparing 38 subjects with the Western-type genotype and 72 subjects with the East Asian-type cagA genotype. Histological scores of the gastric mucosa were determined using the updated Sydney System to examine the relationship with anti-CagA antibody titers. RESULTS Recombinant 70-100 kDa fragments were immobilized on the ELISA plate. In ROC analysis, the area under the curve of our East Asian-type CagA ELISA was comparable to that of conventional CagA ELISA. The sensitivity of the two ELISAs differed depending on the cagA genotype. The sensitivity of East Asian-type CagA ELISA was higher for subjects infected with East Asian-type cagA H. pylori (P < 0.001), and the sensitivity of the conventional CagA ELISA tended to be higher for subjects infected with Western cagA H. pylori (P = 0.056). The titer of anti-CagA antibody tended to correlate with monocyte infiltration scores (r = 0.25, P = 0.058) and was inversely correlated with H. pylori density (r = -0.26, P = 0.043). CONCLUSION The novel ELISA is useful to detect anti-CagA antibodies in East Asian countries, and the titer may be a marker for predicting chronic gastritis. PMID:28104980

  14. Respiratory failure in a mouse model of myotonic dystrophy does not correlate with the CTG repeat length.

    OpenAIRE

    Panaite, P.A.; Kuntzer, T; Gourdon, G; Barakat-Walter, I.

    2013-01-01

    Myotonic dystrophy (DM1) is a multisystemic disease caused by an expansion of CTG repeats in the region of DMPK, the gene encoding DM protein kinase. The severity of muscle disability in DM1 correlates with the size of CTG expansion. As respiratory failure is one of the main causes of death in DM1, we investigated the correlation between respiratory impairment and size of the (CTG)n repeat in DM1 animal models. Using pressure plethysmography the respiratory function was assessed in control an...

  15. CAG tract of MJD-1 may be prone to frameshifts causing polyalanine accumulation.

    Science.gov (United States)

    Gaspar, C; Jannatipour, M; Dion, P; Laganière, J; Sequeiros, J; Brais, B; Rouleau, G A

    2000-08-12

    Machado-Joseph disease (MJD) is one of several disorders caused by the expansion of a coding CAG repeat (exp-CAG). The presence of intranuclear inclusions (INIs) in patients and cellular models of exp-CAG-associated diseases has lead to a nuclear toxicity model. Similar INIs are found in oculopharyngeal muscular dystrophy, which is caused by a short expansion of an alanine-encoding GCG repeat. Here we propose that transcriptional or translational frameshifts occurring within expanded CAG tracts result in the production and accumulation of polyalanine-containing mutant proteins. We hypothesize that these alanine polymers deposit in cells forming INIs and may contribute to nuclear toxicity. We show evidence that supports our hypothesis in lymphoblast cells from MJD patients, as well as in pontine neurons of MJD brain and in in vitro cell culture models of the disease. We also provide evidence that alanine polymers alone are harmful to cells and predict that a similar pathogenic mechanism may occur in the other CAG repeat disorders.

  16. [C-11]raclopride-PET studies of the Huntington's disease rate of progression : Relevance of the trinucleotide repeat length

    NARCIS (Netherlands)

    Antonini, A; Leenders, KL; Eidelberg, D

    1998-01-01

    We used [C-11]raclopride and positron emission tomography (PET) to assess the relationship between striatal dopamine D2 receptor binding, trinucleotide repeat number (GAG), and subject age in 10 asymptomatic and 8 symptomatic carriers of the Huntington's disease (HD) mutation. In both preclinical an

  17. Hexanucleotide repeats in ALS/FTD form length-dependent RNA foci, sequester RNA binding proteins, and are neurotoxic.

    Science.gov (United States)

    Lee, Youn-Bok; Chen, Han-Jou; Peres, João N; Gomez-Deza, Jorge; Attig, Jan; Stalekar, Maja; Troakes, Claire; Nishimura, Agnes L; Scotter, Emma L; Vance, Caroline; Adachi, Yoshitsugu; Sardone, Valentina; Miller, Jack W; Smith, Bradley N; Gallo, Jean-Marc; Ule, Jernej; Hirth, Frank; Rogelj, Boris; Houart, Corinne; Shaw, Christopher E

    2013-12-12

    The GGGGCC (G4C2) intronic repeat expansion within C9ORF72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Intranuclear neuronal RNA foci have been observed in ALS and FTD tissues, suggesting that G4C2 RNA may be toxic. Here, we demonstrate that the expression of 38× and 72× G4C2 repeats form intranuclear RNA foci that initiate apoptotic cell death in neuronal cell lines and zebrafish embryos. The foci colocalize with a subset of RNA binding proteins, including SF2, SC35, and hnRNP-H in transfected cells. Only hnRNP-H binds directly to G4C2 repeats following RNA immunoprecipitation, and only hnRNP-H colocalizes with 70% of G4C2 RNA foci detected in C9ORF72 mutant ALS and FTD brain tissues. We show that expanded G4C2 repeats are potently neurotoxic and bind hnRNP-H and other RNA binding proteins. We propose that RNA toxicity and protein sequestration may disrupt RNA processing and contribute to neurodegeneration.

  18. CagI is an essential component of the Helicobacter pylori Cag type IV secretion system and forms a complex with CagL.

    Directory of Open Access Journals (Sweden)

    Kieu Thuy Pham

    Full Text Available Helicobacter pylori, the causative agent of type B gastritis, peptic ulcers, gastric adenocarcinoma and MALT lymphoma, uses the Cag type IV secretion system to induce a strong proinflammatory response in the gastric mucosa and to inject its effector protein CagA into gastric cells. CagA translocation results in altered host cell gene expression profiles and cytoskeletal rearrangements, and it is considered as a major bacterial virulence trait. Recently, it has been shown that binding of the type IV secretion apparatus to integrin receptors on target cells is a crucial step in the translocation process. Several bacterial proteins, including the Cag-specific components CagL and CagI, have been involved in this interaction. Here, we have examined the localization and interactions of CagI in the bacterial cell. Since the cagI gene overlaps and is co-transcribed with the cagL gene, the role of CagI for type IV secretion system function has been difficult to assess, and conflicting results have been reported regarding its involvement in the proinflammatory response. Using a marker-free gene deletion approach and genetic complementation, we show now that CagI is an essential component of the Cag type IV secretion apparatus for both CagA translocation and interleukin-8 induction. CagI is distributed over soluble and membrane-associated pools and seems to be partly surface-exposed. Deletion of several genes encoding essential Cag components has an impact on protein levels of CagI and CagL, suggesting that both proteins require partial assembly of the secretion apparatus. Finally, we show by co-immunoprecipitation that CagI and CagL interact with each other. Taken together, our results indicate that CagI and CagL form a functional complex which is formed at a late stage of secretion apparatus assembly.

  19. Respiratory failure in a mouse model of myotonic dystrophy does not correlate with the CTG repeat length.

    Science.gov (United States)

    Panaite, Petrica-Adrian; Kuntzer, Thierry; Gourdon, Geneviève; Barakat-Walter, Ibtissam

    2013-10-01

    Myotonic dystrophy (DM1) is a multisystemic disease caused by an expansion of CTG repeats in the region of DMPK, the gene encoding DM protein kinase. The severity of muscle disability in DM1 correlates with the size of CTG expansion. As respiratory failure is one of the main causes of death in DM1, we investigated the correlation between respiratory impairment and size of the (CTG)n repeat in DM1 animal models. Using pressure plethysmography the respiratory function was assessed in control and transgenic mice carrying either 600 (DM600) or >1300 CTG repeats (DMSXL). The statistical analysis of respiratory parameters revealed that both DM1 transgenic mice sub-lines show respiratory impairment compared to control mice. In addition, there is no significant difference in breathing functions between the DM600 and DMSXL mice. In conclusion, these results indicate that respiratory impairment is present in both transgenic mice sub-lines, but the severity of respiratory failure is not related to the size of the (CTG)n expansion.

  20. HA novel approach to investigate tissue-specific trinucleotide repeat instability

    Directory of Open Access Journals (Sweden)

    Boily Marie-Josee

    2010-03-01

    Full Text Available Abstract Background In Huntington's disease (HD, an expanded CAG repeat produces characteristic striatal neurodegeneration. Interestingly, the HD CAG repeat, whose length determines age at onset, undergoes tissue-specific somatic instability, predominant in the striatum, suggesting that tissue-specific CAG length changes could modify the disease process. Therefore, understanding the mechanisms underlying the tissue specificity of somatic instability may provide novel routes to therapies. However progress in this area has been hampered by the lack of sensitive high-throughput instability quantification methods and global approaches to identify the underlying factors. Results Here we describe a novel approach to gain insight into the factors responsible for the tissue specificity of somatic instability. Using accurate genetic knock-in mouse models of HD, we developed a reliable, high-throughput method to quantify tissue HD CAG repeat instability and integrated this with genome-wide bioinformatic approaches. Using tissue instability quantified in 16 tissues as a phenotype and tissue microarray gene expression as a predictor, we built a mathematical model and identified a gene expression signature that accurately predicted tissue instability. Using the predictive ability of this signature we found that somatic instability was not a consequence of pathogenesis. In support of this, genetic crosses with models of accelerated neuropathology failed to induce somatic instability. In addition, we searched for genes and pathways that correlated with tissue instability. We found that expression levels of DNA repair genes did not explain the tissue specificity of somatic instability. Instead, our data implicate other pathways, particularly cell cycle, metabolism and neurotransmitter pathways, acting in combination to generate tissue-specific patterns of instability. Conclusion Our study clearly demonstrates that multiple tissue factors reflect the level of

  1. Modulation of the age at onset in spinocerebellar ataxia by CAG tracts in various genes

    NARCIS (Netherlands)

    Tezenas du Montcel, S.; Durr, A.; Bauer, P.; Figueroa, K.P.; Ichikawa, Y.; Brussino, A.; Forlani, S.; Rakowicz, M.; Schols, L.; Mariotti, C.; Warrenburg, B.P.C. van de; Orsi, L.; Giunti, P.; Filla, A.; Szymanski, S.; Klockgether, T.; Berciano, J.; Pandolfo, M.; Boesch, S.; Melegh, B.; Timmann, D.; Mandich, P.; Camuzat, A.; Goto, J.; Ashizawa, T.; Cazeneuve, C.; Tsuji, S.; Pulst, S.M.; Brusco, A.; Riess, O.; Brice, A.; Stevanin, G.

    2014-01-01

    Polyglutamine-coding (CAG)n repeat expansions in seven different genes cause spinocerebellar ataxias. Although the size of the expansion is negatively correlated with age at onset, it accounts for only 50-70% of its variability. To find other factors involved in this variability, we performed a regr

  2. Triplet repeat DNA structures and human genetic disease: dynamic mutations from dynamic DNA

    Indian Academy of Sciences (India)

    Richard R Sinden; Vladimir N Potaman; Elena A Oussatcheva; Christopher E Pearson; Yuri L Lyubchenko; Luda S Shlyakhtenko

    2002-02-01

    Fourteen genetic neurodegenerative diseases and three fragile sites have been associated with the expansion of (CTG)n•(CAG)n, (CGG)n•(CCG)n, or (GAA)n•(TTC)n repeat tracts. Different models have been proposed for the expansion of triplet repeats, most of which presume the formation of alternative DNA structures in repeat tracts. One of the most likely structures, slipped strand DNA, may stably and reproducibly form within triplet repeat sequences. The propensity to form slipped strand DNA is proportional to the length and homogeneity of the repeat tract. The remarkable stability of slipped strand DNA may, in part, be due to loop-loop interactions facilitated by the sequence complementarity of the loops and the dynamic structure of three-way junctions formed at the loop-outs.

  3. A novel methylation PCR that offers standardized determination of FMR1 methylation and CGG repeat length without southern blot analysis.

    Science.gov (United States)

    Grasso, Marina; Boon, Elles M J; Filipovic-Sadic, Stela; van Bunderen, Patrick A; Gennaro, Elena; Cao, Ru; Latham, Gary J; Hadd, Andrew G; Coviello, Domenico A

    2014-01-01

    Fragile X syndrome and associated disorders are characterized by the number of CGG repeats and methylation status of the FMR1 gene for which Southern blot (SB) historically has been required for analysis. This study describes a simple PCR-only workflow (mPCR) to replace SB analysis, that incorporates novel procedural controls, treatment of the DNA in separate control and methylation-sensitive restriction endonuclease reactions, amplification with labeled primers, and two-color amplicon sizing by capillary electrophoresis. mPCR was evaluated in two independent laboratories with 76 residual clinical samples that represented typical and challenging fragile X alleles in both males and females. mPCR enabled superior size resolution and analytical sensitivity for size and methylation mosaicism compared to SB. Full mutation mosaicism was detected down to 1% in a background of 99% normal allele with 50- to 100-fold less DNA than required for SB. A low level of full mutation mosaicism in one sample was detected using mPCR but not observed using SB. Overall, the sensitivity for detection of full mutation alleles was 100% (95% CI: 89%-100%) with an accuracy of 99% (95% CI: 93%-100%). mPCR analysis of DNA from individuals with Klinefelter and Turner syndromes, and DNA from sperm and blood, were consistent with SB. As such, mPCR enables accurate, sensitive, and standardized methods of FMR1 analysis that can harmonize results across different laboratories.

  4. Mature clustered, regularly interspaced, short palindromic repeats RNA (crRNA) length is measured by a ruler mechanism anchored at the precursor processing site.

    Science.gov (United States)

    Hatoum-Aslan, Asma; Maniv, Inbal; Marraffini, Luciano A

    2011-12-27

    Precise RNA processing is fundamental to all small RNA-mediated interference pathways. In prokaryotes, clustered, regularly interspaced, short palindromic repeats (CRISPR) loci encode small CRISPR RNAs (crRNAs) that protect against invasive genetic elements by antisense targeting. CRISPR loci are transcribed as a long precursor that is cleaved within repeat sequences by CRISPR-associated (Cas) proteins. In many organisms, this primary processing generates crRNA intermediates that are subject to additional nucleolytic trimming to render mature crRNAs of specific lengths. The molecular mechanisms underlying this maturation event remain poorly understood. Here, we defined the genetic requirements for crRNA primary processing and maturation in Staphylococcus epidermidis. We show that changes in the position of the primary processing site result in extended or diminished maturation to generate mature crRNAs of constant length. These results indicate that crRNA maturation occurs by a ruler mechanism anchored at the primary processing site. We also show that maturation is mediated by specific cas genes distinct from those genes involved in primary processing, showing that this event is directed by CRISPR/Cas loci.

  5. PHOX2B polyalanine repeat length is associated with sudden infant death syndrome and unclassified sudden infant death in the Dutch population.

    Science.gov (United States)

    Liebrechts-Akkerman, Germaine; Liu, Fan; Lao, Oscar; Ooms, Ariadne H A G; van Duijn, Kate; Vermeulen, Mark; Jaddoe, Vincent W; Hofman, Albert; Engelberts, Adèle C; Kayser, Manfred

    2014-07-01

    Unclassified sudden infant death (USID) is the sudden and unexpected death of an infant that remains unexplained after thorough case investigation including performance of a complete autopsy and review of the circumstances of death and the clinical history. When the infant is below 1 year of age and with onset of the fatal episode apparently occurring during sleep, this is referred to as sudden infant death syndrome (SIDS). USID and SIDS remain poorly understood despite the identification of several environmental and some genetic risk factors. In this study, we investigated genetic risk factors involved in the autonomous nervous system in 195 Dutch USID/SIDS cases and 846 Dutch, age-matched healthy controls. Twenty-five DNA variants from 11 genes previously implicated in the serotonin household or in the congenital central hypoventilation syndrome, of which some have been associated with SIDS before, were tested. Of all DNA variants considered, only the length variation of the polyalanine repeat in exon 3 of the PHOX2B gene was found to be statistically significantly associated with USID/SIDS in the Dutch population after multiple test correction. Interestingly, our data suggest that contraction of the PHOX2B exon 3 polyalanine repeat that we found in six of 160 SIDS and USID cases and in six of 814 controls serves as a probable genetic risk factor for USID/SIDS at least in the Dutch population. Future studies are needed to confirm this finding and to understand the functional effect of the polyalanine repeat length variation, in particular contraction, in exon 3 of the PHOX2B gene.

  6. IS1630 of Mycoplasma fermentans, a Novel IS30-Type Insertion Element That Targets and Duplicates Inverted Repeats of Variable Length and Sequence during Insertion

    Science.gov (United States)

    Calcutt, Michael J.; Lavrrar, Jennifer L.; Wise, Kim S.

    1999-01-01

    A new insertion sequence (IS) of Mycoplasma fermentans is described. This element, designated IS1630, is 1,377 bp long and has 27-bp inverted repeats at the termini. A single open reading frame (ORF), predicted to encode a basic protein of either 366 or 387 amino acids (depending on the start codon utilized), occupies most of this compact element. The predicted translation product of this ORF has homology to transposases of the IS30 family of IS elements and is most closely related (27% identical amino acid residues) to the product of the prototype of the group, IS30. Multiple copies of IS1630 are present in the genomes of at least two M. fermentans strains. Characterization and comparison of nine copies of the element revealed that IS1630 exhibits unusual target site specificity and, upon insertion, duplicates target sequences in a manner unlike that of any other IS element. IS1630 was shown to have the striking ability to target and duplicate inverted repeats of variable length and sequence during transposition. IS30-type elements typically generate 2- or 3-bp target site duplications, whereas those created by IS1630 vary between 19 and 26 bp. With the exception of two recently reported IS4-type elements which have the ability to generate variable large duplications (B. B. Plikaytis, J. T. Crawford, and T. M. Shinnick, J. Bacteriol. 180:1037–1043, 1998; E. M. Vilei, J. Nicolet, and J. Frey, J. Bacteriol. 181:1319–1323, 1999), such large direct repeats had not been observed for other IS elements. Interestingly, the IS1630-generated duplications are all symmetrical inverted repeat sequences that are apparently derived from rho-independent transcription terminators of neighboring genes. Although the consensus target site for IS30 is almost palindromic, individual target sites possess considerably less inverted symmetry. In contrast, IS1630 appears to exhibit an increased stringency for inverted repeat recognition, since the majority of target sites had no

  7. CTG trinucleotide repeat "big jumps": large expansions, small mice.

    Directory of Open Access Journals (Sweden)

    Mário Gomes-Pereira

    2007-04-01

    Full Text Available Trinucleotide repeat expansions are the genetic cause of numerous human diseases, including fragile X mental retardation, Huntington disease, and myotonic dystrophy type 1. Disease severity and age of onset are critically linked to expansion size. Previous mouse models of repeat instability have not recreated large intergenerational expansions ("big jumps", observed when the repeat is transmitted from one generation to the next, and have never attained the very large tract lengths possible in humans. Here, we describe dramatic intergenerational CTG*CAG repeat expansions of several hundred repeats in a transgenic mouse model of myotonic dystrophy type 1, resulting in increasingly severe phenotypic and molecular abnormalities. Homozygous mice carrying over 700 trinucleotide repeats on both alleles display severely reduced body size and splicing abnormalities, notably in the central nervous system. Our findings demonstrate that large intergenerational trinucleotide repeat expansions can be recreated in mice, and endorse the use of transgenic mouse models to refine our understanding of triplet repeat expansion and the resulting pathogenesis.

  8. Relation of atrophic gastritis with Helicobacter pylori-CagA+and interleukin-1 gene polymorphisms

    Institute of Scientific and Technical Information of China (English)

    Rafaela Sierra; Francis Mégraud; Clas Une; Vanessa Ramírez; Warner Alpízar-Alpízar; María I González; José A Ramírez; Antoine de Mascarel; Patricia Cuenca; Guillermo Pérez-Pérez

    2008-01-01

    AIM: To determine the association of Helicobacter pylori (H pylon) CagA+ infection and pro-inflammatory poly-morphisms of the genes interleukin (IL)-IRN and IL-1B with the risk of gastric atrophy and peptic ulcers in a dyspeptic population in Costa Rica, a country with high incidence and mortality of gastric cancer. METHODS: Seven biopsy specimens, a fasting blood sample and a questionnaire concerning nutritional and sociodemographic factors were obtained from 501 con-secutive patients who had undergone endoscopy for dyspeptic symptoms. A histopathological diagnosis was made. Pepsinogen concentrations were analyzed by enzyme linked immunosorbent assay (ELISA). Infection with H pylori CagA* was determined by serology and polymerase chain reaction (PCR). IL-1B and IL-1RN polymorphisms genotyping was performed by PCR-restriction fragment length polymorphism (PCR-RFLP) and PCR respectively. RESULTS: In this dyspeptic population, 86% wereHpy/ori positive and of these, 67.8% were positive forCagA. Atrophic antral gastritis (AAG) was associatedwith CagA+ status [odd ratio (OR) = 4.1; P < 0.000]and fruit consumption (OR = 0.3; P < 0.00). Atrophicbody gastritis (ABG) was associated with pepsinogenPGI/PGII < 3.4 (OR = 4.9; P < 0.04) and alcoholconsumption (OR = 7.3; P < 0.02). Duodenal ulcerwas associated with CagA+ (OR = 2.9; P < 0.04) andsmoking (OR = 2.4; P < 0.04). PGI < 60 μg/L as wellas PGI/PGII < 3.4 were associated with CagA+. CONCLUSION: In a dyspeptic population in Costa Rica,H pylori CagA+ is not associated with ABG, but it is arisk factor for AAG. The pro-inflammatory cytokine poly-morphisms IL-1B + 3945 and IL-1RN are not associatedwith the atrophic lesions of this dyspeptic population.

  9. The characteristics of CAG repeat in the CACNA1A gene in the Chinese Han population and its application in molecular diagnosis of spinocerebellar ataxia type 6%中国汉族人群CACNA1A基因CAG重复数目分布特点及其在脊髓小脑性共济失调6型基因诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    翁声通; 甘世锐; 吴志英; 邬剑军; 王柠; 慕容慎行; 吕传真

    2009-01-01

    目的 探讨我国汉族人群CACNA1A基因CAG重复数目分布特点及其在脊髓小脑性共济失调6型(spinocerebellar ataxias type 6,SCA6)基因诊断中的应用.方法 应用"两步PCR法"、变性聚丙烯酰胺凝胶电泳(DPAGE)和测序等方法对300名健康对照及109例无血缘关系的SCA患者进行CACNA1A基因CAG三核苷酸重复数目分析.结果 300名健康对照的CAG重复次数范围为3~18次,以13次最常见.在109例SCA患者中,发现1例SCA6患者,其CAG异常重复次数为24次,该患者的母亲和哥哥亦为SCA6患者,临床上均表现为缓慢进展的小脑性共济失调、构音障碍、眼震、轻度的振动及本体觉减退,遗传早现现象较明显.结论 SCA6病例在我国较少见,进行CACNA1A基因突变分析有助于临床诊断."两步PCR法"可提高CACNA1A基因突变分析的效率.%Objective To investigate distribution of CAG repeat in the CACNA1A gene in theChinese Han population and its application in molecular diagnosis of spinocerebellar ataxia type 6(SCA6).Methods The trinucleotide repeats of CAG were detected by two-step polymerase chain reaction(PCR).denaturing polyacrylamide gel electrophoresis(DPAGE)and DNA sequencing in 300 normal individuals and 109 unrelated SCA patients.Results In normal individuals.the number of CAG repeats ranged from 3 to 18 with 13 being the most frequent repeats.In 109 SCA patients,one patient was identified of 24 repeats and was diagnosed with SCA6.This patient's mother and elder brother were also SCA6 patients.They all showed slowly progressive cerebellar ataxia,dysarthria,nystagmus,minor impairment in vibration sensation and proprioeeptive sensation in clinical manifestation with obvious anticipation.Conclusions SCA6 is rare in the Chinese Population.Mutation analysis of the CACNA1A gene is helpful for clinical diagnosis of SCA6.Two-step PCR increases the efficieney of molecular diagnosis in SCA6.

  10. Heterogeneity of Helicobacter pylori cag genotypes in experimentally infected mice.

    Science.gov (United States)

    Sozzi, M; Crosatti, M; Kim, S K; Romero, J; Blaser, M J

    2001-09-11

    Our aim was to assess whether the Helicobacter pylori population recovered from experimentally infected mice show heterogeneity in cag genotypes. Wild-type FVB/N mice were challenged with strain Hp1 and sacrificed 8 weeks later. Direct PCR on gastric tissue was performed using primers for glmM and cagA, and for these two genes and for cagE and virB11 using DNA from the infecting and the emerging strains. The gastric tissues of two of five mice were PCR+ for glmM but not cagA. For the infecting strain, the PCRs for all four genes studied were strongly positive, but the sweeps from the emerging strains from both mice gave weaker signals for cagA and cagE. Examination of single colonies showed reduced or absent signals for cagA and cagE in relation to glmM and virB11. Serial dilution PCR of sweep isolates from the mice showed a 10- to 100-fold decrease in cagA signal compared to the infecting strain. The decrease of cagA and cagE, but not virB11, amplification and lack of cagA hybridization in Southern blots indicates a selective loss of the right half of the cag island during murine infection. This phenomenon is consistent with host-induced adaptive changes of cag genotype in the population of colonizing H. pylori cells.

  11. Expressed Sequence Tags Analysis and Design of Simple Sequence Repeats Markers from a Full-Length cDNA Library in Perilla frutescens (L.

    Directory of Open Access Journals (Sweden)

    Eun Soo Seong

    2015-01-01

    Full Text Available Perilla frutescens is valuable as a medicinal plant as well as a natural medicine and functional food. However, comparative genomics analyses of P. frutescens are limited due to a lack of gene annotations and characterization. A full-length cDNA library from P. frutescens leaves was constructed to identify functional gene clusters and probable EST-SSR markers via analysis of 1,056 expressed sequence tags. Unigene assembly was performed using basic local alignment search tool (BLAST homology searches and annotated Gene Ontology (GO. A total of 18 simple sequence repeats (SSRs were designed as primer pairs. This study is the first to report comparative genomics and EST-SSR markers from P. frutescens will help gene discovery and provide an important source for functional genomics and molecular genetic research in this interesting medicinal plant.

  12. TPR重复和ELTR排型:重复的长度变化是一种功能进化的机制%TPR repeats and ELTR pattern: length variation as a function evolution mechanism

    Institute of Scientific and Technical Information of China (English)

    杨克迁

    2007-01-01

    TPR repeat was originally defined as a 34 amino acid structural repeat (TPR-34). Equal length tandem repeats (ELTR) was proposed to represent the ancestral repeat pattern. Length polymorphism of TPR repeats was analyzed using PATTINPROT, two new versions of TPR repeat of 40 and 42 amino acids were identified. These 'long' TPRs endow new functional capacities to the resulting proteins. A strong correlation between varied lengths and new functions supports the hypothesis that length variation is an underlying mechanism for the function evolution of repeat containing proteins.%TPR 重复最初定义为一个34个氨基酸的蛋白结构重复.本文用PATTINPROT软件对基因库中TPR 重复长度多样性进行了分析,发现40和42个氨基酸TPR 重复大量存在. 含40和42个氨基酸TPR重复序列蛋白的功能分析说明,这些长的TPR重复可以赋予蛋白新的功能.根据以上分析,提出重复序列的长度变化可能是功能进化的一种发生机制.

  13. Analysis of polyglutamine-coding repeats in the TATA-binding protein in different human populations and in patients with schizophrenia an bipolar affective disorder

    Energy Technology Data Exchange (ETDEWEB)

    Rubinsztein, D.C.; Leggo, J. [Addenbrooke`s National Health Service Trust, Cambridge (United Kingdom); Crow, T.J. [Cambridge Univ. (United Kingdom)] [and others

    1996-09-20

    A new class of disease (including Huntington disease, Kennedy disease, and spinocerebellar ataxias types 1 and 3) results from abnormal expansions of CAG trinucleotides in the coding regions of genes. In all of these diseases the CAG repeats are thought to be translated into polyglutamine tracts. There is accumulating evidence arguing for CAG trinucleotide expansions as one of the causative disease mutations in schizophrenia and bipolar affective disorder. We and others believe that the TATA-binding protein (TBP) is an important candidate to investigate in these diseases as it contains a highly polymorphic stretch of glutamine codons, which are close to the threshold length where the polyglutamine tracts start to be associated with disease. Thus, we examined the lengths of this polyglutamine repeat in normal unrelated East Anglians, South African Blacks, sub-Saharan Africans mainly from Nigeria, and Asian Indians. We also examined 43 bipolar affective disorder patients and 65 schizophrenic patients. The range of polyglutamine tract-lengths that we found in humans was from 26-42 codons. No patients with bipolar affective disorder and schizophrenia had abnormal expansions at this locus. 22 refs., 1 tab.

  14. Analysis and application of SCA1 and SCA3/MJD gene CAG repeats in Han population in Northeastern China%东北地区正常汉族人群 SCA1及 SCA3/MJD基因内CAG重复变异研究

    Institute of Scientific and Technical Information of China (English)

    姜淼; 金春莲; 林长坤; 邱广荣; 柳宗兰; 王朝祥; 孙开来

    2004-01-01

    目的对东北地区110名汉族正常人 SCA1及 SCA3/MJD基因(CAG)n拷贝进行检测,探讨其正常变异范围,并对临床诊断为遗传型脊髓小脑共济失调的8个家系的25例患者和6个散发病例进行基因分型评价和症状前及产前诊断.方法应用荧光-PCR方法测定不同基因型片段长度,并进行DNA序列分析.结果 SCA3/MJD基因(CAG)n正常变异范围为14~38个拷贝,集中于14个拷贝,其等位基因频率为39.55%,杂合频率为78.18%,共13种等位基因.检出一个家系先证者携带有(CAG)68的SCA3/MJD基因,并对该家系成员进行了症状前诊断,没有发现(CAG)n拷贝异常突变; SCA1基因内(CAG)n正常变异范围20~39拷贝,集中于26及27次,等位基因频率分别为34.09%和20.91%,杂合频率为84.55%,共13种等位基因;散发病例未检出CAG扩展性突变.结论 SCA1及 SCA3/MJD基因中(CAG)n 正常变异范围存在地区和种族差异,SCAs基因分型是该病症状前及产前诊断的首选策略.

  15. Correlation of inter-locus polyglutamine toxicity with CAG•CTG triplet repeat expandability and flanking genomic DNA GC content.

    Directory of Open Access Journals (Sweden)

    Colm E Nestor

    Full Text Available Dynamic expansions of toxic polyglutamine (polyQ-encoding CAG repeats in ubiquitously expressed, but otherwise unrelated, genes cause a number of late-onset progressive neurodegenerative disorders, including Huntington disease and the spinocerebellar ataxias. As polyQ toxicity in these disorders increases with repeat length, the intergenerational expansion of unstable CAG repeats leads to anticipation, an earlier age-at-onset in successive generations. Crucially, disease associated alleles are also somatically unstable and continue to expand throughout the lifetime of the individual. Interestingly, the inherited polyQ length mediating a specific age-at-onset of symptoms varies markedly between disorders. It is widely assumed that these inter-locus differences in polyQ toxicity are mediated by protein context effects. Previously, we demonstrated that the tendency of expanded CAG•CTG repeats to undergo further intergenerational expansion (their 'expandability' also differs between disorders and these effects are strongly correlated with the GC content of the genomic flanking DNA. Here we show that the inter-locus toxicity of the expanded polyQ tracts of these disorders also correlates with both the expandability of the underlying CAG repeat and the GC content of the genomic DNA flanking sequences. Inter-locus polyQ toxicity does not correlate with properties of the mRNA or protein sequences, with polyQ location within the gene or protein, or steady state transcript levels in the brain. These data suggest that the observed inter-locus differences in polyQ toxicity are not mediated solely by protein context effects, but that genomic context is also important, an effect that may be mediated by modifying the rate at which somatic expansion of the DNA delivers proteins to their cytotoxic state.

  16. Amplification of a single-locus variable-number direct repeats with restriction fragment length polymorphism (DR-PCR/RFLP) for genetic typing of Acinetobacter baumannii strains.

    Science.gov (United States)

    Nowak-Zaleska, Alicja; Krawczyk, Beata; Kotłowski, Roman; Mikucka, Agnieszka; Gospodarek, Eugenia

    2008-01-01

    In search of an effective DNA typing technique for Acinetobacter baumannii strains for hospital epidemiology use, the performance and convenience of a new target sequence was evaluated. Using known genomic sequences of Acinetobacter baumannii strains AR 319754 and ATCC 17978, we developed single-locus variable-number direct-repeat analysis using polymerase chain reaction-restriction fragment length polymorphism (DR-PCR/RFLP) method. A total of 90 Acinetobacter baumannii strains isolated from patients of the Clinical Hospital in Bydgoszcz, Poland, were examined. Initially, all strains were typed using macrorestriction analysis of the chromosomal DNA by pulsed-field gel electrophoresis (REA-PFGE). Digestion of the chromosomal DNA with the ApaI endonuclease and separation of the fragments by PFGE revealed 21 unique types. Application of DR-PCR/RFLP resulted in recognition of 12 clusters. The results showed that the DR-PCR/RFLP method is less discriminatory than REA-PFGE, however, the novel genotyping method can be used as an alternative technique for generating DNA profiles in epidemiological studies of intra-species genetic relatedness of Acinetobacter baumannii strains.

  17. Clustering of Beijing genotype Mycobacterium tuberculosis isolates from the Mekong delta in Vietnam on the basis of variable number of tandem repeat versus restriction fragment length polymorphism typing

    Directory of Open Access Journals (Sweden)

    Huyen Mai NT

    2013-02-01

    Full Text Available Abstract Background In comparison to restriction fragment length polymorphism (RFLP typing, variable number of tandem repeat (VNTR typing is easier to perform, faster and yields results in a simple, numerical format. Therefore, this technique has gained recognition as the new international gold standard in typing of Mycobacterium tuberculosis. However, some reports indicated that VNTR typing may be less suitable for Beijing genotype isolates. We therefore compared the performance of internationally standardized RFLP and 24 loci VNTR typing to discriminate among 100 Beijing genotype isolates from the Southern Vietnam. Methods Hundred Beijing genotype strains defined by spoligotyping were randomly selected and typed by RFLP and VNTR typing. The discriminatory power of VNTR and RFLP typing was compared using the Bionumerics software. Results Among 95 Beijing strains available for analysis, 14 clusters were identified comprising 34 strains and 61 unique profiles in 24 loci VNTR typing ((Hunter Gaston Discrimination Index (HGDI = 0.994. 13 clusters containing 31 strains and 64 unique patterns in RFLP typing (HGDI = 0.994 were found. Nine RFLP clusters were subdivided by VNTR typing and 12 VNTR clusters were split by RFLP. Five isolates (5% revealing double alleles or no signal in two or more loci in VNTR typing could not be analyzed. Conclusions Overall, 24 loci VNTR typing and RFLP typing had similar high-level of discrimination among 95 Beijing strains from Southern Vietnam. However, loci VNTR 154, VNTR 2461 and VNTR 3171 had hardly added any value to the level of discrimination.

  18. Spinocerebellar ataxia type 1 and Machado-Joseph disease: Incidence of CAG expansions among adult-onset ataxia patients from 311 families with dominant, recessive, or sporadic ataxia

    Energy Technology Data Exchange (ETDEWEB)

    Ranum, L.P.W.; Gomez, C.; Orr, H.T. [Univ. of Minnesota, Minneapolis, MN (United States)] [and others

    1995-09-01

    The ataxias are a complex group of diseases with both environmental and genetic causes. Among the autosomal dominant forms of ataxia the genes for two, spinocerebellar ataxia type 1 (SCA1) and Machado-Joseph disease (MJD), have been isolated. In both of these disorders the molecular basis of disease is the expansion of an unstable CAG trinucleotide repeat. To assess the frequency of the SCA1 and MJD trinucleotide repeat expansions among individuals diagnosed with ataxia, we have collected DNA from individuals representing 311 families with adult-onset ataxia of unknown etiology and screened these samples for trinucleotide repeat expansions within the SCA1 and MJD genes. Within this group there are 149 families with dominantly inherited ataxia. Of these, 3% have SCA1 trinucleotide repeat expansions, whereas 21% were positive for the MJD trinucleotide expansion. Thus, together SCA1 and MJD represent 24% of the autosomal dominant ataxias in our group, and the frequency of MJD is substantially greater than that of SCA1. For the 57 patients with MJD trinucleotide repeat expansions, a strong inverse correlation between CAG repeat size and age at onset was observed (r = -.838). Among the MJD patients, the normal and affected ranges of CAG repeat size are 14-40 and 68-82 repeats, respectively. For SCA1 the normal and affected ranges are much closer, containing 19-38 and 40-81 CAG repeats, respectively. 30 refs., 1 fig., 3 tabs.

  19. Early cognitive dysfunction in the HD 51 CAG transgenic rat model of Huntington's disease.

    Science.gov (United States)

    Fink, Kyle D; Rossignol, Julien; Crane, Andrew T; Davis, Kendra K; Bavar, Angela M; Dekorver, Nicholas W; Lowrance, Steven A; Reilly, Mark P; Sandstrom, Michael I; von Hörsten, Stephan; Lescaudron, Laurent; Dunbar, Gary L

    2012-06-01

    Huntington's disease (HD) is a neurodegenerative disorder in humans caused by an expansion of a CAG trinucleotide repeat that produces choreic movements, which are preceded by cognitive deficits. The HD transgenic rat (tgHD), which contains the human HD mutation with a 51 CAG repeat allele, exhibits motor deficits that begin when these rats are 12 months of age. However, there are no reports of cognitive dysfunction occurring prior to this. To assess whether cognitive dysfunction might precede motor deficits in tgHD rats, one group of 9-month-old male rats with homozygotic mutated genes and one group of wild-type (WT) rats underwent three testing phases in a unique Spatial Operant Reversal Test (SORT) paradigm, as well as assessment of spontaneous motor activity. After testing, morphological and histological examination of the brains were made. Results indicated that tgHD rats acquired the cued-response (Phase 1) portion of the SORT, but made significantly more errors during the reversal (Phase 2) and during the pseudorandomized reversals (Phase 3) portion of the study, when compared to WT rats. Analysis of the data using mathematical principles of reinforcement revealed no memory, motor, or motivational deficits. These results indicate that early cognitive dysfunction, as measured by the SORT, occur prior to motor deficits, gross anatomical changes, or cell loss in the tgHD rat with 51 CAG repeats, and suggest that this protocol could provide a useful screen for therapeutic studies.

  20. Intermediate-length polyglutamine in ATXN2 is a possible risk factor among Eastern Chinese patients with amyotrophic lateral sclerosis.

    Science.gov (United States)

    Lu, Hai-Peng; Gan, Shi-Rui; Chen, Sheng; Li, Hong-Fu; Liu, Zhi-Jun; Ni, Wang; Wang, Ning; Wu, Zhi-Ying

    2015-03-01

    An effective treatment for amyotrophic lateral sclerosis (ALS) has not yet been found because the pathogenesis of this fatal disease is not well understood. A number of previous studies demonstrated that intermediate-length polyglutamine repeats within the ataxin-2 gene (ATXN2) might be a risk factor among patients with ALS in Western countries. Here, we aim to determine whether this sequence is a risk factor in Eastern Chinese ALS patients. Therefore, 379 unrelated sporadic ALS patients, 15 unrelated familial ALS patients, and 900 neurologically normal controls were studied. The ATXN2 CAG repeats were amplified using polymerase chain reaction. The products were separated on an 8% polyacrylamide gel and confirmed using Sanger sequencing. The results were evaluated using SPSS 17.0. We found that ATXN2 intermediate-length polyglutamine expansions greater than 24 and 27 repeats were associated with sporadic ALS. Our finding supports the hypothesis that ATXN2 plays an important role in the pathogenesis of ALS.

  1. TAA repeat variation in the GRIK2 gene does not influence age at onset in Huntington's disease

    Science.gov (United States)

    Lee, Ji-Hyun; Lee, Jong-Min; Ramos, Eliana Marisa; Gillis, Tammy; Mysore, Jayalakshmi S.; Kishikawa, Shotaro; Hadzi, Tiffany; Hendricks, Audrey E.; Hayden, Michael R.; Morrison, Patrick J.; Nance, Martha; Ross, Christopher A.; Margolis, Russell L.; Squitieri, Ferdinando; Gellera, Cinzia; Gomez-Tortosa, Estrella; Ayuso, Carmen; Suchowersky, Oksana; Trent, Ronald J.; McCusker, Elizabeth; Novelletto, Andrea; Frontali, Marina; Jones, Randi; Ashizawa, Tetsuo; Frank, Samuel; Saint-Hilaire, Marie-Helene; Hersch, Steven M.; Rosas, Herminia D.; Lucente, Diane; Harrison, Madaline B.; Zanko, Andrea; Abramson, Ruth K.; Marder, Karen; Sequeiros, Jorge; Landwehrmeyer, G. Bernhard; Network, Ira Shoulson; Myers, Richard H.; MacDonald, Marcy E.; Gusella, James F.

    2013-01-01

    Huntington's disease is a neurodegenerative disorder caused by an expanded CAG trinucleotide repeat whose length is the major determinant of age at onset but remaining variation appears to be due in part to the effect of genetic modifiers. GRIK2, which encodes GluR6, a mediator of excitatory neurotransmission in the brain, has been suggested in several studies to be a modifier gene based upon a 3′ untranslated region TAA trinucleotide repeat polymorphism. Prior to investing in detailed studies of the functional impact of this polymorphism, we sought to confirm its effect on age at onset in a much larger dataset than in previous investigations. We genotyped the HD CAG repeat and the GRIK2 TAA repeat in DNA samples from 2,911 Huntington's disease subjects with known age at onset, and tested for a potential modifier effect of GRIK2 using a variety of statistical approaches. Unlike previous reports, we detected no evidence of an influence of the GRIK2 TAA repeat polymorphism on age at motor onset. Similarly, the GRIK2 polymorphism did not show significant modifier effect on psychiatric and cognitive age at onset in HD. Comprehensive analytical methods applied to a much larger sample than in previous studies do not support a role for GRIK2 as a genetic modifier of age at onset of clinical symptoms in Huntington's disease. PMID:22771793

  2. Helicobacter pylori cagA Promoter Region Sequences Influence CagA Expression and Interleukin 8 Secretion.

    Science.gov (United States)

    Ferreira, Rui M; Pinto-Ribeiro, Ines; Wen, Xiaogang; Marcos-Pinto, Ricardo; Dinis-Ribeiro, Mário; Carneiro, Fátima; Figueiredo, Ceu

    2016-02-15

    Heterogeneity at the Helicobacter pylori cagA gene promoter region has been linked to variation in CagA expression and gastric histopathology. Here, we characterized the cagA promoter and expression in 46 H. pylori strains from Portugal. Our results confirm the relationship between cagA promoter region variation and protein expression originally observed in strains from Colombia. We observed that individuals with intestinal metaplasia were all infected with H. pylori strains containing a specific cagA motif. Additionally, we provided novel functional evidence that strain-specific sequences in the cagA promoter region and CagA expression levels influence interleukin 8 secretion by the host gastric epithelial cells.

  3. Targeting several CAG expansion diseases by a single antisense oligonucleotide.

    Directory of Open Access Journals (Sweden)

    Melvin M Evers

    Full Text Available To date there are 9 known diseases caused by an expanded polyglutamine repeat, with the most prevalent being Huntington's disease. Huntington's disease is a progressive autosomal dominant neurodegenerative disorder for which currently no therapy is available. It is caused by a CAG repeat expansion in the HTT gene, which results in an expansion of a glutamine stretch at the N-terminal end of the huntingtin protein. This polyglutamine expansion plays a central role in the disease and results in the accumulation of cytoplasmic and nuclear aggregates. Here, we make use of modified 2'-O-methyl phosphorothioate (CUGn triplet-repeat antisense oligonucleotides to effectively reduce mutant huntingtin transcript and protein levels in patient-derived Huntington's disease fibroblasts and lymphoblasts. The most effective antisense oligonucleotide, (CUG(7, also reduced mutant ataxin-1 and ataxin-3 mRNA levels in spinocerebellar ataxia 1 and 3, respectively, and atrophin-1 in dentatorubral-pallidoluysian atrophy patient derived fibroblasts. This antisense oligonucleotide is not only a promising therapeutic tool to reduce mutant huntingtin levels in Huntington's disease but our results in spinocerebellar ataxia and dentatorubral-pallidoluysian atrophy cells suggest that this could also be applicable to other polyglutamine expansion disorders as well.

  4. Depletion of Cognate Charged Transfer RNA Causes Translational Frameshifting within the Expanded CAG Stretch in Huntingtin

    Directory of Open Access Journals (Sweden)

    Hannah Girstmair

    2013-01-01

    Full Text Available Huntington disease (HD, a dominantly inherited neurodegenerative disorder caused by the expansion of a CAG-encoded polyglutamine (polyQ repeat in huntingtin (Htt, displays a highly heterogeneous etiopathology and disease onset. Here, we show that the translation of expanded CAG repeats in mutant Htt exon 1 leads to a depletion of charged glutaminyl-transfer RNA (tRNAGln-CUG that pairs exclusively to the CAG codon. This results in translational frameshifting and the generation of various transframe-encoded species that differently modulate the conformational switch to nucleate fibrillization of the parental polyQ protein. Intriguingly, the frameshifting frequency varies strongly among different cell lines and is higher in cells with intrinsically lower concentrations of tRNAGln-CUG. The concentration of tRNAGln-CUG also differs among different brain areas in the mouse. We propose that translational frameshifting may act as a significant disease modifier that contributes to the cell-selective neurotoxicity and disease course heterogeneity of HD on both cellular and individual levels.

  5. Depletion of cognate charged transfer RNA causes translational frameshifting within the expanded CAG stretch in huntingtin.

    Science.gov (United States)

    Girstmair, Hannah; Saffert, Paul; Rode, Sascha; Czech, Andreas; Holland, Gudrun; Bannert, Norbert; Ignatova, Zoya

    2013-01-31

    Huntington disease (HD), a dominantly inherited neurodegenerative disorder caused by the expansion of a CAG-encoded polyglutamine (polyQ) repeat in huntingtin (Htt), displays a highly heterogeneous etiopathology and disease onset. Here, we show that the translation of expanded CAG repeats in mutant Htt exon 1 leads to a depletion of charged glutaminyl-transfer RNA (tRNA)(Gln-CUG) that pairs exclusively to the CAG codon. This results in translational frameshifting and the generation of various transframe-encoded species that differently modulate the conformational switch to nucleate fibrillization of the parental polyQ protein. Intriguingly, the frameshifting frequency varies strongly among different cell lines and is higher in cells with intrinsically lower concentrations of tRNA(Gln-CUG). The concentration of tRNA(Gln-CUG) also differs among different brain areas in the mouse. We propose that translational frameshifting may act as a significant disease modifier that contributes to the cell-selective neurotoxicity and disease course heterogeneity of HD on both cellular and individual levels.

  6. Enzymatic amplification of synthetic oligodeoxyribonucleotides: implications for triplet repeat expansions in the human genome.

    Science.gov (United States)

    Behn-Krappa, A; Doerfler, W

    1994-01-01

    The triplet repeat sequences (CGG)n, (GCT)n, and (CAG)n, which naturally occur in the human genome, can be autonomously expanded in human DNA by an as yet unknown mechanism. These in part excessive expansions have been causally related to human genetic diseases, the fragile X (Martin-Bell) syndrome, to myotonic dystrophy (Curschmann-Steinert), to spinal and bulbar muscular atrophy (Kennedy disease), and recently to Huntington disease. A GCC trinucleotide repeat was found to be expanded and methylated in the fragile site FRAXE on the human X chromosome. These findings were associated with mental retardation (Knight et al., 1993). In spinocerebellar ataxia type 1 (SCA1), a polymorphic CAG repeat was found to be unstable and expanded in individuals with that disease (Orr et al., 1993). We have demonstrated in in vitro experiments that the synthetic oligodeoxyribonucleotides (CGG)17, (CGG)12, (GCC)17, (CG)25, (CTG)17, or (CAG)17 plus (GTC)17, in the absence of added natural DNA, can be expanded with Taq polymerase in the polymerase chain reaction (PCR). Some expansion can already be detected after 4 PCR cycles. The E. coli Klenow DNA polymerase also functions in a similar amplification and expansion reaction performed at 37 degrees C without cycling. Other oligodeoxyribonucleotides, like, (CGG)7, (CGGT)13, or (TAA)17, are devoid of this property or have very low activity. The cytidine-methylated polymers (GCC)17 or (CG)25 yield expansion products of considerably reduced chain lengths. The expansion of the polymer (CGG)17 is affected by cytidine methylation to a lesser degree. A specific sequence and/or secondary structure and high CG content appear to be requirements for this expansion reaction by a possible slippage mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Genome-Wide Demethylation Promotes Triplet Repeat Instability Independently of Homologous Recombination

    Science.gov (United States)

    Dion, Vincent; Lin, Yunfu; Price, Brandee A.; Fyffe, Sharyl L.; Seluanov, Andrei; Gorbunova, Vera; Wilson, John H.

    2008-01-01

    Trinucleotide repeat instability is intrinsic to a family of human neurodegenerative diseases. The mechanism leading to repeat length variation is unclear. We previously showed that treatment with the demethylating agent 5-aza-2′-deoxycytidine (5-aza-CdR) dramatically increases triplet repeat instability in mammalian cells. Based on previous reports that demethylation increases homologous recombination (HR), and our own observations that HR destabilizes triplet repeats, we hypothesized that demethylation alters repeat stability by stimulating HR. Here, we test that hypothesis at the Aprt (adenosine phosphoribosyl transferase) locus in CHO cells, where CpG demethylation and HR have both been shown to increase CAG repeat instability. We find that the rate of HR at the Aprt locus is not altered by demethylation. The spectrum of recombinants, however, was shifted from the usual 6:1 ratio of conversions to crossovers to more equal proportions in 5-aza-CdR-treated cells. The subtle influences of demethylation on HR at the Aprt locus are not sufficient to account for its dramatic effects on repeat instability. We conclude that 5-aza-CdR promotes triplet repeat instability independently of HR. PMID:18083071

  8. A new subtype of 3' region of cagA gene in Helicobacter pyloristrains isolated from Zhejiang Province in China

    Institute of Scientific and Technical Information of China (English)

    Ran Tao; Ping-Chu Fang; Hai-Yan Liu; Yun-Shui Jiang; Jing Chen

    2004-01-01

    AIM: To isolate the subtypes of 3' region of cagA gene in Helicobacter pylori (H pylori) strains from Zhejiang Province in China and to investigate their relations to H pylori-associated gastroduodenal diseases.METHODS: One hundred and thirty-seven H pylori clinical strains were isolated from the gastric mucosa specimens of 74 patients with chronic gastritis, 61 with peptic ulceration,and 2 with gastric cancer. Bacterial genomic DNA was extracted and 3' region of cagA gene was amplified by polymerase chain reaction (PCR). Subtypes of 3' region of cagA gene were determined by the size of PCR amplified segments. The sequences of the subtypes were analyzed by PCR-based sequencing.RESULTS: Of the 137 Hpylori isolates from Zhejiang Province,132 (96.4%) yielded PCR products that could be classified into three groups of subtypes, named as subtypes Ⅰ, Ⅱ,and Ⅲ according to their sizes. The sizes of subtypes Ⅰ, Ⅱ,and Ⅲ were 648-650 bp, 705-707 bp, and 815 bp, respectively.Among the 132 cagA-positive H pyloristrains, 123 (93.2%)belonged to the group of subtype Ⅰ, 6 (4.5%) presented subtype Ⅱ, 1 (0.8%) was subtype Ⅲ, and 2 (1.5%) presented subtypes Ⅰ and Ⅲ both. The primary structure of subtype Ⅰwas composed of 3 repeats of R1, 1 repeat of R2 and 1repeat of R3. Subtype Ⅱ possessing 4 repeats of R1, 2repeats of R2 and 1 repeat of R3 was a newly found type of 3' region of cagA gene which had not been reported before. The primary structure of subtype Ⅲ consisted of 4repeats of R1, 1 repeat of R2 and 2 repeats of R3. Comparison of the sequences of subtype Ⅰ strains with the corresponding sequences deposited in GenBank, showed a similarity of95.0% (94.0-96.1%) for nucleotide sequences and 95.9%(94.9-97.4%) for deduced amino acid sequences.Comparison of the sequences of subtype Ⅲ strains with the corresponding sequences deposited in GenBank,showed a similarity of 93.9% (90.8-96.9%) for nucleotide sequences and 93.2% (90.2-96.2%) for deduced amino acid

  9. Repeat length variation in the 5'UTR of myo-inositol monophosphatase gene is related to phytic acid content and contributes to drought tolerance in chickpea (Cicer arietinum L.).

    Science.gov (United States)

    Joshi-Saha, Archana; Reddy, Kandali S

    2015-09-01

    Myo-inositol metabolism plays a significant role in plant growth and development, and is also used as a precursor for many important metabolites, such as ascorbate, pinitol, and phytate. Phytate (inositol hexakisphosphate) is the major storage pool for phosphate in the seeds. It is utilized during seed germination and growth of the developing embryo. In addition, it is implicated in protection against oxidative stress. In the present study, a panel of chickpea accessions was used for an association analysis. Association analysis accounting for population structure and relative kinship identified alleles of a simple sequence repeat marker, NCPGR90, that are associated with both phytic acid content and drought tolerance. These alleles varied with respect to the dinucleotide CT repeats present within the marker. NCPGR90 located to the 5'UTR of chickpea myo-inositol monophosphatase gene (CaIMP) and showed transcript length variation in drought-tolerant and drought-susceptible accessions. CaIMP from a drought-tolerant accession with a smaller repeat was almost 2-fold upregulated as compared to a susceptible accession having a longer repeat, even under control non-stressed conditions. This study suggests an evolution of simple sequence repeat length variation in CaIMP, which might be regulating phytic acid levels to confer drought tolerance in natural populations of chickpea.

  10. The (CAG)n tract of Machado–Joseph Disease gene (ATXN3): a comparison between DNA and mRNA in patients and controls

    Science.gov (United States)

    Bettencourt, Conceição; Santos, Cristina; Montiel, Rafael; Kay, Teresa; Vasconcelos, João; Maciel, Patrícia; Lima, Manuela

    2010-01-01

    Machado–Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder of late onset (occurring at a mean age of 40.2 years). The clinical manifestation of MJD is dependent on the presence of an expansion of the (CAG)n motif within exon 10 of the ATXN3 gene, located at 14q32.1. The variance in onset of MJD is only partially correlated (∼50–80%) with the extension of the CAG tract in genomic DNA (gDNA). The main aim of this work was to determine whether there are discrepancies in the size of the (CAG)n tract between gDNA and mRNA, and to establish whether there is a better association between age at onset and repeat size at the mRNA level. We typed gDNA and cDNA samples for the (CAG)n tract totalizing 108 wild-type and 52 expanded ATXN3 alleles. In wild-type alleles no differences were found between gDNA and cDNA. In expanded alleles, the CAG repeat size in gDNA was not always directly transcribed into the mRNA; on average there were differences of +1 repeat at the cDNA level. The slight discrepancies obtained were insufficient to cause significant differences in the distribution of the expanded alleles, and therefore no improvement in onset variance explanation was obtained with mRNA. PMID:19935829

  11. Longitudinal analysis of the behavioural phenotype in Hdh(CAG)150 Huntington's disease knock-in mice.

    Science.gov (United States)

    Brooks, Simon; Higgs, Gemma; Jones, Lesley; Dunnett, Stephen B

    2012-06-01

    In people with Huntington's disease, an expanded CAG repeat sequence on the HTT gene confers a toxic gain function resulting in a progressive and fatal neurodegeneration. The Hdh((CAG)Q150) Huntington's disease mouse line is a knock-in model of the disease that carries ∼150 CAG repeats on the normal mouse Htt locus. To determine that these mice are a useful model of the disease, they were assessed longitudinally for motor and cognitive deficits relevant to the human disease state. Each test was conducted bi-monthly across the lifespan of the animal. The results indicate that the Hdh(Q150/Q150) mice were impaired on each of the measures used, with deficits appearing on a 3-stage water maze test at 4 months of age and on prepulse inhibition at 6 months of age, both of which were prior to the manifestation of motor abnormalities. Grip strength, as measured by the inverted cage lid test, was reduced in the Hdh(Q150/Q150) mice from 10 months of age, when the male mice also exhibited weight loss relative to their wildtype littermates. On the accelerating rotarod, deficits in the carrier mice did not appear until they were 21 months old. Our results demonstrate that the Hdh((CAG)150) is a valid model of HD that displays early and progressive cognitive deficits that precede the onset of motor abnormalities.

  12. 2003 CAG Educational Needs Assessment Report

    Directory of Open Access Journals (Sweden)

    Desmond Leddin

    2003-01-01

    Full Text Available The annual survey of Canadian Association of Gastroenterology (CAG members’ educational needs was conducted online this past April. One hundred eightyseven individuals (one fifth of the membership completed the needs assessment. The topic most in demand for future educational events was inflammatory bowel disease, both from the clinical and basic science perspectives. Other highly rated topics were endoscopy, pharmacological therapeutics, celiac disease and pancreatitis/pancreatic disease. Educational materials were judged to be the most valuable component of exhibit areas. Results of the needs assessment were used to shape the 2004 Canadian Digestive Diseases Week (CDDW program.

  13. Msh2 acts in medium-spiny striatal neurons as an enhancer of CAG instability and mutant huntingtin phenotypes in Huntington's disease knock-in mice.

    Science.gov (United States)

    Kovalenko, Marina; Dragileva, Ella; St Claire, Jason; Gillis, Tammy; Guide, Jolene R; New, Jaclyn; Dong, Hualing; Kucherlapati, Raju; Kucherlapati, Melanie H; Ehrlich, Michelle E; Lee, Jong-Min; Wheeler, Vanessa C

    2012-01-01

    The CAG trinucleotide repeat mutation in the Huntington's disease gene (HTT) exhibits age-dependent tissue-specific expansion that correlates with disease onset in patients, implicating somatic expansion as a disease modifier and potential therapeutic target. Somatic HTT CAG expansion is critically dependent on proteins in the mismatch repair (MMR) pathway. To gain further insight into mechanisms of somatic expansion and the relationship of somatic expansion to the disease process in selectively vulnerable MSNs we have crossed HTT CAG knock-in mice (HdhQ111) with mice carrying a conditional (floxed) Msh2 allele and D9-Cre transgenic mice, in which Cre recombinase is expressed specifically in MSNs within the striatum. Deletion of Msh2 in MSNs eliminated Msh2 protein in those neurons. We demonstrate that MSN-specific deletion of Msh2 was sufficient to eliminate the vast majority of striatal HTT CAG expansions in HdhQ111 mice. Furthermore, MSN-specific deletion of Msh2 modified two mutant huntingtin phenotypes: the early nuclear localization of diffusely immunostaining mutant huntingtin was slowed; and the later development of intranuclear huntingtin inclusions was dramatically inhibited. Therefore, Msh2 acts within MSNs as a genetic enhancer both of somatic HTT CAG expansions and of HTT CAG-dependent phenotypes in mice. These data suggest that the selective vulnerability of MSNs may be at least in part contributed by the propensity for somatic expansion in these neurons, and imply that intervening in the expansion process is likely to have therapeutic benefit.

  14. Progressive CAG expansion in the brain of a novel R6/1-89Q mouse model of Huntington's disease with delayed phenotypic onset.

    Science.gov (United States)

    Vatsavayai, Sarat C; Dallérac, Glenn M; Milnerwood, Austen J; Cummings, Damian M; Rezaie, Payam; Murphy, Kerry P S J; Hirst, Mark C

    2007-04-30

    Transgenic models representing Huntington's disease (HD) have proved useful for understanding the cascade of molecular events leading to the disease. We report an initial characterisation of a novel transgenic mouse model derived from a spontaneous truncation event within the R6/1 transgene. The transgene is widely expressed, carries 89 CAG repeats and the animals exhibit a significantly milder neurological phenotype with delayed onset compared to R6/1. Moreover, we report evidence of progressive somatic CAG expansions in the brain starting at an early age before an overt phenotype has developed. This novel line shares a common genetic ancestry with R6/1, differing only in CAG repeat number, and therefore, provides an additional tool with which to examine early molecular and neurophysiological changes in HD.

  15. Summary of the 2002 CAG Strategic Planning Survey

    Directory of Open Access Journals (Sweden)

    Philip M Sherman

    2004-01-01

    Full Text Available In this Journal, we have recently highlighted the progress of the Canadian Association of Gastroenterology (CAG in meeting the goals and objectives outlined in the first Strategic Plan developed in 1993 (1. In September 2002, a Strategic Planning survey was mailed to all members of the CAG (a copy of the cover letter and survey are present for viewing on the CAG Web site www.cag-acg.org/whatsnew/strat_plann_surv.htm. The results of the responses to this survey were collated and presented to the Past Presidents of the CAG at a retreat held during the summer of 2003. These findings were then employed to develop a Strategic Plan for the CAG to guide its progress and development over the next five to ten years. A subsequent issue of this Journal will include a presentation of the CAG 2004 Strategic Plan, which was finalized and approved by the CAG Governing Board during the annual fall meeting in October 2003.

  16. Modulation of the age at onset in spinocerebellar ataxia by CAG tracts in various genes.

    Science.gov (United States)

    Tezenas du Montcel, Sophie; Durr, Alexandra; Bauer, Peter; Figueroa, Karla P; Ichikawa, Yaeko; Brussino, Alessandro; Forlani, Sylvie; Rakowicz, Maria; Schöls, Ludger; Mariotti, Caterina; van de Warrenburg, Bart P C; Orsi, Laura; Giunti, Paola; Filla, Alessandro; Szymanski, Sandra; Klockgether, Thomas; Berciano, José; Pandolfo, Massimo; Boesch, Sylvia; Melegh, Bela; Timmann, Dagmar; Mandich, Paola; Camuzat, Agnès; Goto, Jun; Ashizawa, Tetsuo; Cazeneuve, Cécile; Tsuji, Shoji; Pulst, Stefan-M; Brusco, Alfredo; Riess, Olaf; Brice, Alexis; Stevanin, Giovanni

    2014-09-01

    Polyglutamine-coding (CAG)n repeat expansions in seven different genes cause spinocerebellar ataxias. Although the size of the expansion is negatively correlated with age at onset, it accounts for only 50-70% of its variability. To find other factors involved in this variability, we performed a regression analysis in 1255 affected individuals with identified expansions (spinocerebellar ataxia types 1, 2, 3, 6 and 7), recruited through the European Consortium on Spinocerebellar Ataxias, to determine whether age at onset is influenced by the size of the normal allele in eight causal (CAG)n-containing genes (ATXN1-3, 6-7, 17, ATN1 and HTT). We confirmed the negative effect of the expanded allele and detected threshold effects reflected by a quadratic association between age at onset and CAG size in spinocerebellar ataxia types 1, 3 and 6. We also evidenced an interaction between the expanded and normal alleles in trans in individuals with spinocerebellar ataxia types 1, 6 and 7. Except for individuals with spinocerebellar ataxia type 1, age at onset was also influenced by other (CAG)n-containing genes: ATXN7 in spinocerebellar ataxia type 2; ATXN2, ATN1 and HTT in spinocerebellar ataxia type 3; ATXN1 and ATXN3 in spinocerebellar ataxia type 6; and ATXN3 and TBP in spinocerebellar ataxia type 7. This suggests that there are biological relationships among these genes. The results were partially replicated in four independent populations representing 460 Caucasians and 216 Asian samples; the differences are possibly explained by ethnic or geographical differences. As the variability in age at onset is not completely explained by the effects of the causative and modifier sister genes, other genetic or environmental factors must also play a role in these diseases.

  17. Survey of Current Practices among Members of CAG in the Follow-Up of Patients Diagnosed with Gastric Ulcer

    Directory of Open Access Journals (Sweden)

    Niall P Breslin

    1999-01-01

    Full Text Available INTRODUCTION: Guidelines recommend a policy of endoscopic follow-up of all gastric ulcers until healing. Analysis of data from the Alberta Endoscopy Project indicates that fewer than 50% of patients diagnosed with benign gastric ulcer had undergone a repeat procedure. The practice and attitudes of physician members of the Canadian Association of Gastroenterology (CAG on the follow-up of such patients were assessed.

  18. Comparative genotyping of Campylobacter jejuni by amplified fragment length polymorphism, multilocus sequence typing, and short repeat sequencing: Strain diversity, host range, and recombination

    NARCIS (Netherlands)

    Schouls, L.M.; Reulen, S.; Duim, B.; Wagenaar, J.A.; Willems, R.J.L.; Dingle, K.E.; Colles, F.M.; Embden, van J.D.A.

    2003-01-01

    Three molecular typing methods were used to study the relationships among 184 Campylobacter strains isolated from humans, cattle, and chickens. All strains were genotyped by amplified fragment length polymorphism (AFLP) analysis, multilocus sequence typing (MLST), and sequence analysis of a genomic

  19. The Repeated Computation of the Bond Length and Ground- State Energy for H2 +%H2+键长和基态能量的再计算

    Institute of Scientific and Technical Information of China (English)

    李旭; 胡先权

    2002-01-01

    Ritz variation method was used to find the numerical relation bctween the energy near the ground - state of the hydrogenmolecular ion H2 + .and the changes of the variation parameter andthe bond length, the computation formula of bond length and ground- state energy for H2 * was also obtained by means of the method ofparabolie interpolation. The computation results were much closer toexperinental values than those of Refs. [ 1,2]' s.%用Ritz变分法求出了氢分子离子H2+基态能量附近的能量随变分参数和分子键长变化的数值关系,并用抛物线插值法获得了H2+键长和基态能量的值及其计算公式,比文献[1,2]更接近于实验值.

  20. Bovine proteins containing poly-glutamine repeats are often polymorphic and enriched for components of transcriptional regulatory complexes

    LENUS (Irish Health Repository)

    Whan, Vicki

    2010-11-23

    Abstract Background About forty human diseases are caused by repeat instability mutations. A distinct subset of these diseases is the result of extreme expansions of polymorphic trinucleotide repeats; typically CAG repeats encoding poly-glutamine (poly-Q) tracts in proteins. Polymorphic repeat length variation is also apparent in human poly-Q encoding genes from normal individuals. As these coding sequence repeats are subject to selection in mammals, it has been suggested that normal variations in some of these typically highly conserved genes are implicated in morphological differences between species and phenotypic variations within species. At present, poly-Q encoding genes in non-human mammalian species are poorly documented, as are their functions and propensities for polymorphic variation. Results The current investigation identified 178 bovine poly-Q encoding genes (Q ≥ 5) and within this group, 26 genes with orthologs in both human and mouse that did not contain poly-Q repeats. The bovine poly-Q encoding genes typically had ubiquitous expression patterns although there was bias towards expression in epithelia, brain and testes. They were also characterised by unusually large sizes. Analysis of gene ontology terms revealed that the encoded proteins were strongly enriched for functions associated with transcriptional regulation and many contributed to physical interaction networks in the nucleus where they presumably act cooperatively in transcriptional regulatory complexes. In addition, the coding sequence CAG repeats in some bovine genes impacted mRNA splicing thereby generating unusual transcriptional diversity, which in at least one instance was tissue-specific. The poly-Q encoding genes were prioritised using multiple criteria for their likelihood of being polymorphic and then the highest ranking group was experimentally tested for polymorphic variation within a cattle diversity panel. Extensive and meiotically stable variation was identified

  1. Bovine proteins containing poly-glutamine repeats are often polymorphic and enriched for components of transcriptional regulatory complexes

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    Barendse William

    2010-11-01

    Full Text Available Abstract Background About forty human diseases are caused by repeat instability mutations. A distinct subset of these diseases is the result of extreme expansions of polymorphic trinucleotide repeats; typically CAG repeats encoding poly-glutamine (poly-Q tracts in proteins. Polymorphic repeat length variation is also apparent in human poly-Q encoding genes from normal individuals. As these coding sequence repeats are subject to selection in mammals, it has been suggested that normal variations in some of these typically highly conserved genes are implicated in morphological differences between species and phenotypic variations within species. At present, poly-Q encoding genes in non-human mammalian species are poorly documented, as are their functions and propensities for polymorphic variation. Results The current investigation identified 178 bovine poly-Q encoding genes (Q ≥ 5 and within this group, 26 genes with orthologs in both human and mouse that did not contain poly-Q repeats. The bovine poly-Q encoding genes typically had ubiquitous expression patterns although there was bias towards expression in epithelia, brain and testes. They were also characterised by unusually large sizes. Analysis of gene ontology terms revealed that the encoded proteins were strongly enriched for functions associated with transcriptional regulation and many contributed to physical interaction networks in the nucleus where they presumably act cooperatively in transcriptional regulatory complexes. In addition, the coding sequence CAG repeats in some bovine genes impacted mRNA splicing thereby generating unusual transcriptional diversity, which in at least one instance was tissue-specific. The poly-Q encoding genes were prioritised using multiple criteria for their likelihood of being polymorphic and then the highest ranking group was experimentally tested for polymorphic variation within a cattle diversity panel. Extensive and meiotically stable variation was

  2. Transcription of TP0126, Treponema pallidum putative OmpW homolog, is regulated by the length of a homopolymeric guanosine repeat.

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    Giacani, Lorenzo; Brandt, Stephanie L; Ke, Wujian; Reid, Tara B; Molini, Barbara J; Iverson-Cabral, Stefanie; Ciccarese, Giulia; Drago, Francesco; Lukehart, Sheila A; Centurion-Lara, Arturo

    2015-06-01

    An effective mechanism for introduction of phenotypic diversity within a bacterial population exploits changes in the length of repetitive DNA elements located within gene promoters. This phenomenon, known as phase variation, causes rapid activation or silencing of gene expression and fosters bacterial adaptation to new or changing environments. Phase variation often occurs in surface-exposed proteins, and in Treponema pallidum subsp. pallidum, the syphilis agent, it was reported to affect transcription of three putative outer membrane protein (OMP)-encoding genes. When the T. pallidum subsp. pallidum Nichols strain genome was initially annotated, the TP0126 open reading frame was predicted to include a poly(G) tract and did not appear to have a predicted signal sequence that might suggest the possibility of its being an OMP. Here we show that the initial annotation was incorrect, that this poly(G) is instead located within the TP0126 promoter, and that it varies in length in vivo during experimental syphilis. Additionally, we show that TP0126 transcription is affected by changes in the poly(G) length consistent with regulation by phase variation. In silico analysis of the TP0126 open reading frame based on the experimentally identified transcriptional start site shortens this hypothetical protein by 69 amino acids, reveals a predicted cleavable signal peptide, and suggests structural homology with the OmpW family of porins. Circular dichroism of recombinant TP0126 supports structural homology to OmpW. Together with the evidence that TP0126 is fully conserved among T. pallidum subspecies and strains, these data suggest an important role for TP0126 in T. pallidum biology and syphilis pathogenesis.

  3. Molecular analysis of the (CAGN repeat causing Huntington′s disease in 34 Iranian families

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    Hormozian F

    2004-01-01

    Full Text Available Huntington′s disease (HD is an inherited neurodegenerative disorder characterized by chorea and progressive dementia. The mutation causing the disease has been identified as an unstable expansion of a trinucleotide (CAG n at the 5′ end of the IT 15 gene on chromosome 4. We have analyzed the distribution of CAG repeats in 71 Iranian individuals (34 patients and 37 unaffected family members belonging to 31 unrelated families thought to segregate HD. We found one expanded CAG allele in 22 individuals (65% belonging to 21 unrelated families. In these HD patients, expanded alleles varied from 40 to 83 CAG units and normal alleles varied from 13 to 36 CAGs. A significant negative correlation between age at onset of symptoms and size of the expanded CAG allele was found (r= - 0.51; P=0. 1. In addition, we genotyped 25 unrelated control individuals (total of 50 alleles and found normal CAG repeats varying from 10 to 34 units. In conclusion, our results showed that molecular confirmation of the clinical diagnosis in HD should be sought in all suspected patients, making it possible for adequate genetic counseling. This Study is the first report of molecular diagnosis of Huntington disease among Iranian population and ever in Middle East and with regard to high frequency of consanguinity marriage in this region.

  4. Correlation study between the polymorphism of repetitive sequence in gene CAG of androgen receptor and the occurrence and progression of prostate cancer

    Institute of Scientific and Technical Information of China (English)

    Xiao-Lei Zhai; Xiao-Wei Qu; Liang Guo; Qian-He Ha

    2014-01-01

    Objective: To explore the relation between the polymorphism of repetitive sequence in gene CAG of androgen receptor (AR) and the susceptibility and clinical stages as well as pathological grading of prostate cancer among Han population. Method: Sixty-eight cases with prostate cancer hospitalized in Urinary Surgery Department from Feb. 2010 to Feb. 2012 and 60 healthy cases were chosen as research subjects. Methods of PCR and direct sequencing were adopted to detect DNA sequence of AR gene and the length of repetitive sequence in CAG. Results: The lengths of repetitive sequence in CAG of patients with prostate cancer and healthy people were (22.3±4.6) and (23.0±4.9), respectively showing no statistical significance. Comparing length (repetitive sequence of CAG)>22, those with that ﹤ 22 suffer a remarkably higher risk of prostate cancer (P﹤0.05). The number of repetitive sequence in CAG of patients at clinical stage C-D was less than that of patients at stage B, and the number of repetitive sequence in CAG of patients with poorly differentiated prostate cancer was also less than that of patients with moderately and highly differentiated prostate cancer. But there was no statistical significance int the difference (P>0.05); the proportion of patients with length ﹤22 at clinical stage C-D was much larger than that of patients at clinical stage B (P﹤0.05), and as the aggravation of pathological grading, the proportion of patients with the length ﹤22 was also remarkably increased and there was significant difference between patients with highly differentiated prostate cancer and those with poorly differentiated prostate cancer (P﹤0.05). Conclusions: There is correlation between the occurrence and development of prostate cancer in Han population and the polymorphism of repetitive sequence in gene CAG of androgen receptor. The less the number of repetitive sequence in CAG is, the higher the risk of prostate cancer will be and the more severe the clinical

  5. Helicobacter pylori cag pathogenicity island genotype diversity within the gastric niche of a single host.

    Science.gov (United States)

    Matteo, Mario José; Granados, Gabriela; Pérez, Cecilia Valeria; Olmos, Martín; Sanchez, Cristian; Catalano, Mariana

    2007-05-01

    cag pathogenicity island (PAI) integrity was investigated in isolates from multiple biopsies recovered from 40 patients in an attempt to determine the co-existence of a varying cagPAI-positive to cagPAI-negative ratio in a single host. Six biopsies were obtained from each patient during the same endoscopic session. cagPAI analysis included amplification of seven loci (cagA, cagE, cagG, cagM, cagT, HP0527 and HP0524) and the left end of cagII (LEC). Absence of the island was confirmed by empty-site PCR. lspA-glmM RFLP and random amplified polymorphic DNA PCR were used for strain delineation. The number of biopsies with Helicobacter pylori-positive culture ranged from three to six per patient and a total of 218 isolates were recovered. Mixed infection was only found in two patients. Nearly one-third of the 40 patients harboured isolates with an intact cagPAI in all niches, another third of the isolates were empty-site-positive in all niches, whilst the remaining third of the isolates had a disrupted cagPAI in all or at least one of the niches. Co-existence of variants of the same strain with different cagPAI genotypes was observed in one-quarter of patients. The variations in cagPAI genotype included co-existence of: diverse cagPAI deletions in different niches, variants with intact and with partially deleted islands, variants with empty-site-positive and with partially deleted cagPAIs, and variants with an intact cagPAI and with empty-site-positive. Half of the patients with different cagPAI genotypes harboured an intact cagPAI in at least one niche. Co-existence of diverse genotypes of putative virulence factors in a single host must be considered when drawing a correlation with clinical presentation.

  6. Anti-CagA IgG Antibody is Independent from Helicobacter pylori vacA and cagA Genotypes

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    Hashem Fakhre Yaseri

    2015-12-01

    Full Text Available Background: Helicobacter pylori strains have two classical virulence genes, the cytotoxinassociated A (cagA gene and the vacuolating cytotoxin A (vacA gene, which are located in thecag pathogenicity island (cagPAI. Serum immunoglobulin G (IgG antibodies to H. pylori,especially, the CagA antigen may be a reliable marker for selection of dyspeptic patients for upperendoscopy.Methods: Serum sample of 129 dyspeptic patients with positive H. pylori, were tested for serumIgG Anti-CagA antibody by ELISA. The presence of the cagA and vacA genotypes weredetermined using polymerase chain reaction (PCR on biopsy samples taken via endoscopy.Results: Positive serum IgG anti-CagA antibodies in patients with cagA+/vacA+ and cagA+/vacA- genotypes were 22/23 (95.6% and 18/19 (94.7%, respectively. In addition, serum IgG anti-CagAantibodies in patients with cagA-/vacA+ and cagA-/vacA- genotypes were 22/47 (46.8% and 33/40(82.5%, respectively.Conclusions: It can be concluded that the serum IgG anti-CagA antibody alone could selectpatients with dyspepsia following upper endoscopy. The assessment of vacuolating cytotoxinactivity of H. Pylori is, therefore, not required, even when vacA gene is positive. This hypothesisneeds to be studied in a large number of patients with dyspepsia.

  7. Infection with cagA-positive and cagA-negative types of Helicobacter pylori among children and adolescents with gastrointestinal symptoms in Latvia.

    Science.gov (United States)

    Daugule, I; Rumba, I; Engstrand, L; Ejderhamn, J

    2003-10-01

    In order to determine the prevalence of concomitant cagA-positive and cagA-negative Helicobacter pylori genotypes in individual subjects, a group of 56 symptomatic patients (aged 8-18 years) was studied. Among 31 patients culture-positive for Helicobacter pylori, only cagA-positive colonies were isolated from 18 patients, both cagA-positive and cagA-negative genotypes were isolated from 4 patients, and in 9 patients all of the individual colonies isolated were cagA-negative, but in seven of them a pool of colonies was positive for cagA. Thus, the presence of both cagA-positive and cagA-negative genotypes in the same individual was identified in 11 of the 31 culture-positive patients tested, and most of the patients predominantly colonized by cagA-negative strains also harbored a small amount of cagA-positive strains. Previous or current infection with cagA-positive strains of Helicobacter pylori was observed in 50 of the 56 patients studied.

  8. Rediscovery of historical Vitis vinifera varieties from the South Anatolia region by using amplified fragment length polymorphism and simple sequence repeat DNA fingerprinting methods.

    Science.gov (United States)

    Yilancioglu, Kaan; Cetiner, Selim

    2013-05-01

    Anatolia played an important role in the diversification and spread of economically important Vitis vinifera varieties. Although several biodiversity studies have been conducted with local cultivars in different regions of Anatolia, our aim is to gain a better knowledge on the biodiversity of endangered historical V. vinifera varieties in the northern Adana region of southern Anatolia, particularly those potentially displaying viticulture characteristics. We also demonstrate the genetic relatedness in a selected subset of widely cultivated and commercialized V. vinifera collection cultivars, which were obtained from the National Grapevine Germplasm located at the Institute of Viticulture, Turkey. In the present study, microsatellites were used in narrowing the sample size from 72 accessions down to a collection of 27 varieties. Amplified fragment length polymorphisms were then employed to determine genetic relatedness among this collection and local V. vinifera cultivars. The unweighted pair group method with arithmetic mean cluster and principal component analyses revealed that Saimbeyli local cultivars form a distinct group, which is distantly related to a selected subset of V. vinifera collection varieties from all over Turkey. To our knowledge, this is the first study conducted with these cultivars. Further preservation and use of these potential viticultural varieties will be helpful to avoid genetic erosion and to promote continued agriculture in the region.

  9. PCR bias in amplification of androgen receptor alleles, a trinucleotide repeat marker used in clonality studies.

    OpenAIRE

    Mutter, G L; Boynton, K A

    1995-01-01

    Trinucleotide CAG repeats in the X-linked human androgen receptor gene (HUMARA) have proved a useful means of determining X chromosome haplotypes, and when combined with methylation analysis of nearby cytosine residues permits identification of non-random X inactivation in tumors of women. Co-amplification of two alleles in a heterozygote generates PCR products which differ in the number of CAG units, and thus their melting and secondary structure characteristics. We have shown that under opt...

  10. Differential effects of the Huntington's disease CAG mutation in striatum and cerebellum are quantitative not qualitative.

    Science.gov (United States)

    Fossale, Elisa; Seong, Ihn Sik; Coser, Kathryn R; Shioda, Toshi; Kohane, Isaac S; Wheeler, Vanessa C; Gusella, James F; MacDonald, Marcy E; Lee, Jong-Min

    2011-11-01

    Huntington's disease (HD) involves marked early neurodegeneration in the striatum, whereas the cerebellum is relatively spared despite the ubiquitous expression of full-length mutant huntingtin, implying that inherent tissue-specific differences determine susceptibility to the HD CAG mutation. To understand this tissue specificity, we compared early mutant huntingtin-induced gene expression changes in striatum to those in cerebellum in young Hdh CAG knock-in mice, prior to onset of evident pathological alterations. Endogenous levels of full-length mutant huntingtin caused qualitatively similar, but quantitatively different gene expression changes in the two brain regions. Importantly, the quantitatively different responses in the striatum and cerebellum in mutant mice were well accounted for by the intrinsic molecular differences in gene expression between the striatum and cerebellum in wild-type animals. Tissue-specific gene expression changes in response to the HD mutation, therefore, appear to reflect the different inherent capacities of these tissues to buffer qualitatively similar effects of mutant huntingtin. These findings highlight a role for intrinsic quantitative tissue differences in contributing to HD pathogenesis, and likely to other neurodegenerative disorders exhibiting tissue-specificity, thereby guiding the search for effective therapeutic interventions.

  11. Amplification of GAA/TTC triplet repeat in vitro: preferential expansion of (TTC)n strand.

    Science.gov (United States)

    Wu, M J; Chow, L W; Hsieh, M

    1998-08-14

    Several human hereditary neuromuscular and neurodegenerative diseases are caused by abnormal expansion of triplet repeat sequences (TRSs) CAG/CTG, CGG/CCG, or GAA/TTC on certain chromosomes. It is generally accepted that multiple slippage synthesis accounts for the instabilities of TRS. Earlier in vitro experiments by Behn-Krappa and Doerfler showed that TRS with high GC content can be expanded. In contrast, here we demonstrated that certain AT-rich TRSs, (TTC)17, (GAA)10/(TTC)10 and (GAA)17/(TTC)17, were also expansion-prone in PCR. With respect to the sequence of TRS, surprisingly, we found that the AT-rich (GAA)17/(TTC)17 extended more efficiently than the GC-rich (CAG)17/(CTG)17. This strongly suggested that the AT content of the repeat may influence TRS expansion. Furthermore, to examine the expansion of single-stranded TRS, we showed that only (TTC)17, but not the complementary (GAA)17, can be expanded. This suggested that a T-T mismatch may stabilize compatible secondary structures, most likely hairpins, for slippage synthesis. However, another poly-pyrimidine TRS, (CCT)17, is not amplification-prone in PCR. Due to the high C-content, this TRS is unlikely to adopt hairpin structures at the high pH used for PCR. Thus, the single-stranded PCR experiment may serve as an indirect assay for the ability of a sequence to adopt a hairpin conformation. When amplification was performed in reactions using Klenow DNA polymerase, only the double-stranded TRSs can be expanded. The reaction rate for (GAA)10/(TTC)10 was slower than for (GAA)17/(TTC)17, suggesting that the length of the repeat may be important for the amplification of TRS. The findings of these in vitro experiments may aid in understanding TRS expansion in vivo.

  12. [Production of a recombinant CagA protein for the detection of Helicobacter pylori CagA antibodies].

    Science.gov (United States)

    Akgüç, Miray; Karatayli, Ersin; Çelik, Esra; Koyuncu, Duygu; Çelik, İnci; Karatayli, Senem Ceren; Özden, Ali; Bozdayi, A Mithat

    2014-07-01

    At present, Helicobacter pylori infections affect approximately 50% of the world population. It is known that H.pylori is related with several gastric diseases including chronic atrophic gastritis, peptic and gastric ulcers as well as gastric carcinomas. CagA (Cytotoxin-associated gene A) protein which is one of the most important virulence factors of H.pylori, is thought to be responsible for the development of gastric cancer. CagA is a 128 kDa hydrophilic protein which binds to the epitelial stomach cells and is known to be phosphorylated on its EPIYA regions. The EPIYA regions are highly variable and carry a higher risk of developing gastric cancer than CagA negative strains. The aim of this study was to construct a prokaryotic expression system expressing a recombinant CagA protein, which can be used for the detection of anti-CagA antibodies. For the isolation of H.pylori genomic DNA, a total of 112 gastric biopsy samples obtained from patients who were previously found positive for rapid urease (CLO) test, were used. H.pylori DNAs were amplified from 57 of those samples by polymerase chain reaction (PCR) and of them 35 were found positive in terms of cagA gene. Different EPIYA motifs were detected in 25 out of 35 cagA positive samples, and one of those samples that contained the highest number of EPIYA motif, was chosen for the cloning procedure. Molecular cloning and expression of the recombinant fragment were performed with Champion Pet151/D expression vector (Invitrogen, USA), the expression of which was induced by the addition of IPTG (Isopropyl-beta-D-thiogalactopyranoside) into the E.coli culture medium. Expression was observed with anti-histidin HRP (Horse Radish Peroxidase) antibodies by SDS-PAGE and Western Blot (WB) analysis. In our study, two clones possessing different fragments from the same H.pylori strain with three different EPIYA motifs were succesfully expressed. Since CagA antigen plays a signicant role in the pathogenesis of H

  13. Relationship between gastric disease and deletion of cag pathogenicity island genes of Helicobacter pylori in gastric juice.

    Science.gov (United States)

    Kawamura, Osamu; Murakami, Masami; Araki, Osamu; Yamada, Takuro; Tomizawa, Sayaka; Shimoyama, Yasuyuki; Minashi, Keiko; Maeda, Masaki; Kusano, Motoyasu; Mori, Masatomo

    2003-01-01

    The cag pathogenicity island genes of Helicobacter pylori (ie, cag1, cag5, cagT, cagE, and cagA) were detected by PCR in DNA extracted from endoscopically collected gastric juice, and the relationship between these genes and gastric disease was studied in 25 patients with early gastric cancer, 9 patients with gastric ulcer, and 15 patients with chronic active gastritis. In three patients with early gastric cancer and one patient with gastric ulcer, cag pathogenicity island genes were amplified although H. pylori was not detected by conventional methods. Compared with conventional methods, the sensitivity of detection of cag genes was 92.3% (36/39) and the specificity was 60% (6/10). Among the patients with cagA amplification, only cagE was not amplified in one case each with early cancer and chronic active gastritis. In addition, none of cag1, cag5, cagT, and cagE were amplified in spite of cagA amplification in one patient with gastric ulcer. This method is a simple procedure, has a high sensitivity, and appears to be useful for accurate assessment of infection with cagA-positive strains. Because deletion of cag PAI genes was found in the patients with all three gastric diseases that we studied, it was suggested that the pathogenicity of H. pylori might not be determined by cag PAI genes in those cases.

  14. Expression of expanded CAG transcripts triggers nucleolar stress in Huntington's disease.

    Science.gov (United States)

    Tsoi, Ho; Chan, Ho Yin Edwin

    2013-06-01

    Polyglutamine (polyQ) diseases, including several types of spinocerebellar ataxias and Huntington's disease (HD), are dominantly inherited neurodegenerative disorders caused by the expansion of the glutamine-coding CAG repeat in the open reading frame of the disease gene. Apart from being translated to produce toxic elongated polyQ domain-containing disease proteins, transcribed expanded CAG RNAs per se also exert toxicity in polyQ degeneration. In the R6/2 HD transgenic mouse model, expanded mutant Huntingtin (Htt) transcripts were found to physically interact with nucleolin (NCL), a nucleolar protein that plays a crucial role in ribosome biogenesis. We further demonstrated that mutant Htt transcripts deprived NCL from binding onto the Upstream Control Element (UCE) of the ribosomal RNA (rRNA) promoter. This resulted in UCE hypermethylation which abolished the binding of the transcription factor Upstream Binding Factor to UCE and subsequently led to down-regulation of pre-45s rRNA transcription. We also found that the p53/mitochondria-dependent nucleolar stress cell death pathway was activated in polyQ diseases. Ribosomal RNA transcription dysfunction has been reported in other types of neurodegenerative disorders including Alzheimer's disease; it is anticipated that nucleolar stress is one common pathogenic signaling mechanism shared by different forms of neurodegeneration.

  15. Msh2 acts in medium-spiny striatal neurons as an enhancer of CAG instability and mutant huntingtin phenotypes in Huntington's disease knock-in mice.

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    Marina Kovalenko

    Full Text Available The CAG trinucleotide repeat mutation in the Huntington's disease gene (HTT exhibits age-dependent tissue-specific expansion that correlates with disease onset in patients, implicating somatic expansion as a disease modifier and potential therapeutic target. Somatic HTT CAG expansion is critically dependent on proteins in the mismatch repair (MMR pathway. To gain further insight into mechanisms of somatic expansion and the relationship of somatic expansion to the disease process in selectively vulnerable MSNs we have crossed HTT CAG knock-in mice (HdhQ111 with mice carrying a conditional (floxed Msh2 allele and D9-Cre transgenic mice, in which Cre recombinase is expressed specifically in MSNs within the striatum. Deletion of Msh2 in MSNs eliminated Msh2 protein in those neurons. We demonstrate that MSN-specific deletion of Msh2 was sufficient to eliminate the vast majority of striatal HTT CAG expansions in HdhQ111 mice. Furthermore, MSN-specific deletion of Msh2 modified two mutant huntingtin phenotypes: the early nuclear localization of diffusely immunostaining mutant huntingtin was slowed; and the later development of intranuclear huntingtin inclusions was dramatically inhibited. Therefore, Msh2 acts within MSNs as a genetic enhancer both of somatic HTT CAG expansions and of HTT CAG-dependent phenotypes in mice. These data suggest that the selective vulnerability of MSNs may be at least in part contributed by the propensity for somatic expansion in these neurons, and imply that intervening in the expansion process is likely to have therapeutic benefit.

  16. Construction of prokaryotic expression system of 2 148-bp fragment from cagA gene and detection of cagA gene, CagA protein in Helicobacter pyloriisolates and its antibody in sera of patients

    Institute of Scientific and Technical Information of China (English)

    Jie Yan; Yuan Wang; Shi-He Shao; Ya-Fei Mao; Hua-Wen Li; Yi-Hui Luo

    2004-01-01

    AIM: To construct a prokaryotic expression system of a Helicobacter pylori ( H pylori) cagA gene fragment and establish enzyme-linked immunosorbent assays (ELISA) for detecting CagA and its antibody, so as to understand the manner in which the infection of CagA-expressing H pylori (CagA+ H pylori) isolates cause diseases.METHODS: H pylori strains in gastric biopsy specimens from 156 patients with positive results in rapid urease test were isolated. PCR was used to detect the frequency of cagA gene in the 109 H pylori isolates and to amplify a 2 148-bp fragment (cagA1) of cagA gene from a clinical strain Y06. A prokaryotic expression system of cagA1 gene was constructed,and the expression of the target recombinant protein (rCagA1) was examined by SDS-PAGE. Western blotting and immunodiffusion assay were employed to determine the immunoreactivity and antigenicity of rCagA1, respectively.Two ELISAs were established to detect CagA expression in 109 H pylori isolates and the presence of CagA antibody in the corresponding patients′ sera, and the correlations between infection with CagA+ H pylori and gastritis as well as peptic ulcer were analyzed.RESULTS: Of all the clinical specimens obtained, 80.8%(126/156) were found to have H pylori isolates and 97.2%of the isolates (106/109) were positive for caaA gene. In comparison with the reported data, the cloned cagA1fragment possessed 94.83% and 93.30% homologies with the nucleotide and putative amino acid sequences,respectively. The output of rCagA1 produced by the constructed recombinant prokaryotic expression system was approximately 30% of the total bacterial protein, rCagA1was able to bind to the commercial antibody against the whole-cells of H pylori and to induce the immunized rabbits to produce antibody with an immunodiffusion titer of 1:4. A proportion as high as 92.6% of the H pylori isolates (101/109)expressed CagA and 88.1% of the patients′ serum samples (96/109) were CagA antibody-positive. The percentage of

  17. A series of N-terminal epitope tagged Hdh knock-in alleles expressing normal and mutant huntingtin: their application to understanding the effect of increasing the length of normal huntingtin’s polyglutamine stretch on CAG140 mouse model pathogenesis

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    Zheng Shuqiu

    2012-08-01

    Full Text Available Abstract Background Huntington’s disease (HD is an autosomal dominant neurodegenerative disease that is caused by the expansion of a polyglutamine (polyQ stretch within Huntingtin (htt, the protein product of the HD gene. Although studies in vitro have suggested that the mutant htt can act in a potentially dominant negative fashion by sequestering wild-type htt into insoluble protein aggregates, the role of the length of the normal htt polyQ stretch, and the adjacent proline-rich region (PRR in modulating HD mouse model pathogenesis is currently unknown. Results We describe the generation and characterization of a series of knock-in HD mouse models that express versions of the mouse HD gene (Hdh encoding N-terminal hemaglutinin (HA or 3xFlag epitope tagged full-length htt with different polyQ lengths (HA7Q-, 3xFlag7Q-, 3xFlag20Q-, and 3xFlag140Q-htt and substitution of the adjacent mouse PRR with the human PRR (3xFlag20Q- and 3xFlag140Q-htt. Using co-immunoprecipitation and immunohistochemistry analyses, we detect no significant interaction between soluble full-length normal 7Q- htt and mutant (140Q htt, but we do observe N-terminal fragments of epitope-tagged normal htt in mutant htt aggregates. When the sequences encoding normal mouse htt’s polyQ stretch and PRR are replaced with non-pathogenic human sequence in mice also expressing 140Q-htt, aggregation foci within the striatum, and the mean size of htt inclusions are increased, along with an increase in striatal lipofuscin and gliosis. Conclusion In mice, soluble full-length normal and mutant htt are predominantly monomeric. In heterozygous knock-in HD mouse models, substituting the normal mouse polyQ and PRR with normal human sequence can exacerbate some neuropathological phenotypes.

  18. The Pathogenic Role of Low Range Repeats in SCA17.

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    Jung Hwan Shin

    Full Text Available SCA17 is an autosomal dominant cerebellar ataxia with expansion of the CAG/CAA trinucleotide repeats in the TATA-binding protein (TBP gene. SCA17 can have various clinical presentations including parkinsonism, ataxia, chorea and dystonia. SCA17 is diagnosed by detecting the expanded CAG repeats in the TBP gene; however, in the literature, pathologic repeat numbers as low as 41 overlap with normal repeat numbers.The subjects in this study included patients with involuntary movement disorders such as cerebellar ataxia, parkinsonism, chorea and dystonia who visited Seoul National University Hospital between Jan. 2006 and Apr. 2014 and were screened for SCA17. Those who were diagnosed with other genetic diseases or nondegenerative diseases were excluded. DNA from healthy subjects who did not have a family history of parkinsonism, ataxia, psychiatric symptoms, chorea or dystonia served as the control. In total, 5242 chromosomes from 2099 patients and 522 normal controls were analyzed.The total number of patients included in the analysis was 2099 (parkinsonism, 1706; ataxia, 345; chorea, 37; and dystonia, 11. In the normal control, up to 44 repeats were found. In the 44 repeat group, there were 7 (0.3% patients and 1 (0.2% normal control. In 43 repeat group, there were 8 (0.4% patients and 2 (0.4% normal controls. In the 42 repeat group, there were 16 (0.8% patients and 3 (0.6% normal controls. In 41 repeat group, there were 48 (2.3% patients and 8 (1.5% normal controls. Considering the overlaps and non-significant differences in allelic frequencies between the patients and the normal controls with low-expansions, we could not determine a definitive cutoff value for the pathologic CAG repeat number of SCA17.Because the statistical analysis between the normal controls and patients with low range expansions failed to show any differences so far, we must consider that clinical cases with low range expansions could be idiopathic movement disorders showing

  19. Mixed Infection with cagA Positive and cagA Negative Strains of Helicobacter pylori Lowers Disease Burden in The Gambia

    Science.gov (United States)

    Secka, Ousman; Antonio, Martin; Berg, Douglas E.; Tapgun, Mary; Bottomley, Christian; Thomas, Vivat; Walton, Robert; Corrah, Tumani; Thomas, Julian E.; Adegbola, Richard A.

    2011-01-01

    Background The prevalence of Helicobacter pylori including strains with putatively virulent genotypes is high, whereas the H. pylori-associated disease burden is low, in Africa compared to developed countries. In this study, we investigated the prevalence of virulence-related H. pylori genotypes and their association with gastroduodenal diseases in The Gambia. Methods and Findings DNA extracted from biopsies and H. pylori cultures from 169 subjects with abdominal pain, dyspepsia or other gastroduodenal diseases were tested by PCR for H. pylori. The H. pylori positive samples were further tested for the cagA oncogene and vacA toxin gene. One hundred and twenty one subjects (71.6%) were H. pylori positive. The cagA gene and more toxigenic s1 and m1 alleles of the vacA gene were found in 61.2%, 76.9% and 45.5% respectively of Gambian patients harbouring H. pylori. There was a high prevalence of cagA positive strains in patients with overt gastric diseases than those with non-ulcerative dyspepsia (NUD) (p = 0.05); however, mixed infection by cagA positive and cagA negative strains was more common in patients with NUD compared to patients with gastric disease (24.5% versus 0%; p = 0.002). Conclusion This study shows that the prevalence of H. pylori is high in dyspeptic patients in The Gambia and that many strains are of the putatively more virulent cagA+, vacAs1 and vacAm1 genotypes. This study has also shown significantly lower disease burden in Gambians infected with a mixture of cag-positive and cag-negative strains, relative to those containing only cag-positive or only cag-negative strains, which suggests that harbouring both cag-positive and cag-negative strains is protective. PMID:22140492

  20. Mixed infection with cagA positive and cagA negative strains of Helicobacter pylori lowers disease burden in The Gambia.

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    Ousman Secka

    Full Text Available BACKGROUND: The prevalence of Helicobacter pylori including strains with putatively virulent genotypes is high, whereas the H. pylori-associated disease burden is low, in Africa compared to developed countries. In this study, we investigated the prevalence of virulence-related H. pylori genotypes and their association with gastroduodenal diseases in The Gambia. METHODS AND FINDINGS: DNA extracted from biopsies and H. pylori cultures from 169 subjects with abdominal pain, dyspepsia or other gastroduodenal diseases were tested by PCR for H. pylori. The H. pylori positive samples were further tested for the cagA oncogene and vacA toxin gene. One hundred and twenty one subjects (71.6% were H. pylori positive. The cagA gene and more toxigenic s1 and m1 alleles of the vacA gene were found in 61.2%, 76.9% and 45.5% respectively of Gambian patients harbouring H. pylori. There was a high prevalence of cagA positive strains in patients with overt gastric diseases than those with non-ulcerative dyspepsia (NUD (p = 0.05; however, mixed infection by cagA positive and cagA negative strains was more common in patients with NUD compared to patients with gastric disease (24.5% versus 0%; p = 0.002. CONCLUSION: This study shows that the prevalence of H. pylori is high in dyspeptic patients in The Gambia and that many strains are of the putatively more virulent cagA+, vacAs1 and vacAm1 genotypes. This study has also shown significantly lower disease burden in Gambians infected with a mixture of cag-positive and cag-negative strains, relative to those containing only cag-positive or only cag-negative strains, which suggests that harbouring both cag-positive and cag-negative strains is protective.

  1. Evaluation of the Pattern of EPIYA Motifs in the Helicobacter pylori cagA Gene of Patients with Gastritis and Gastric Adenocarcinoma from the Brazilian Amazon Region

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    Adenielson Vilar e Silva

    2014-01-01

    Full Text Available The Helicobacter pylori is associated with the development of different diseases. The clinical outcome of infection may be associated with the cagA bacterial genotype. The aim of this study was to determine the EPIYA patterns of strains isolated from patients with gastritis and gastric adenocarcinoma and correlate these patterns with the histopathological features. Gastric biopsy samples were selected from 384 patients infected with H. pylori, including 194 with chronic gastritis and 190 with gastric adenocarcinoma. The presence of the cagA gene and the EPIYA motif was determined by PCR. The cagA gene was more prevalent in patients with gastric cancer and was associated with a higher degree of inflammation, neutrophil activity, and development of intestinal metaplasia. The number of EPIYA-C repeats showed a significant association with an increased risk of gastric carcinoma (OR = 3.79, 95% CI = 1.92–7.46, and P=0.002. A larger number of EPIYA-C motifs were also associated with intestinal metaplasia. In the present study, infection with H. pylori strains harboring more than one EPIYA-C motif in the cagA gene was associated with the development of intestinal metaplasia and gastric adenocarcinoma but not with neutrophil activity or degree of inflammation.

  2. Evaluation of the Pattern of EPIYA Motifs in the Helicobacter pylori cagA Gene of Patients with Gastritis and Gastric Adenocarcinoma from the Brazilian Amazon Region.

    Science.gov (United States)

    Vilar E Silva, Adenielson; Junior, Mario Ribeiro da Silva; Vinagre, Ruth Maria Dias Ferreira; Santos, Kemper Nunes; da Costa, Renata Aparecida Andrade; Fecury, Amanda Alves; Quaresma, Juarez Antônio Simões; Martins, Luisa Caricio

    2014-01-01

    The Helicobacter pylori is associated with the development of different diseases. The clinical outcome of infection may be associated with the cagA bacterial genotype. The aim of this study was to determine the EPIYA patterns of strains isolated from patients with gastritis and gastric adenocarcinoma and correlate these patterns with the histopathological features. Gastric biopsy samples were selected from 384 patients infected with H. pylori, including 194 with chronic gastritis and 190 with gastric adenocarcinoma. The presence of the cagA gene and the EPIYA motif was determined by PCR. The cagA gene was more prevalent in patients with gastric cancer and was associated with a higher degree of inflammation, neutrophil activity, and development of intestinal metaplasia. The number of EPIYA-C repeats showed a significant association with an increased risk of gastric carcinoma (OR = 3.79, 95% CI = 1.92-7.46, and P = 0.002). A larger number of EPIYA-C motifs were also associated with intestinal metaplasia. In the present study, infection with H. pylori strains harboring more than one EPIYA-C motif in the cagA gene was associated with the development of intestinal metaplasia and gastric adenocarcinoma but not with neutrophil activity or degree of inflammation.

  3. Cloning of full-length cDNA of Microsporum canis membrane protein PQ-loop repeat protein gene%犬小孢子菌膜蛋白PQ-LRP基因全长cDNA的克隆

    Institute of Scientific and Technical Information of China (English)

    庞娟; 祝逸平; 杨国玲

    2012-01-01

    Objective To clone the full-length cDNA of Microsporum canis membrane protein PQ-loop repeat protein (PQ-LRP) gene,so as to investigate the roles of PQ-LRP in the pathogenesis of tinea capitis.Methods A Microsporum canis strain (A518) from a patient with tinea capitis served as the experimental strain.Rapid cDNA end amplification (RACE) was performed to clone the full length cDNA sequence of PQLRP gene.Bioinformatics methods were used to make a preliminary functional analysis of the gene.Results The cDNA of PQ-LRP gene was obtained with a full length of 1522 bp,including the 5' untranslated region (49 bp),coding region (1080 bp) and 3' untranslated region (393 bp).The coding region encoded a protein precursor including 359 amino acid residues.The cloned cDNA of PQ-LRP gene shared an 81% nucleotide identity with that of Trichophyton tonsurans and a 79% nucleotide identity with that of Trichophyton rubrum.Conclusions The full-length cDNA of Microsporum canis membrane protein PQ-LRP gene has been successfully cloned,which will provide an important basis for further researches into the roles of PQ-LRP in Microsporum canis-associated diseases.%目的 克隆犬小孢子菌膜蛋白PQ-LRP(PQ-loop repeat protein)基因全长cDNA,探讨在头癣发病机制中的作用.方法 选用犬小孢子菌头癣株(A518)为实验株,采用cDNA快速末端扩增法(RACE),克隆PQ-LRP基因的全长序列.结合生物信息学方法对获得的序列进行初步功能分析.结果 获得犬小孢子菌PQ-LRP全长序列为1522 bp,拥有一个1080 bp的开放阅读框,编码359个氨基酸,5 '非编码区为49 bp,3 '非编码区为393 bp;同源性比对与断发毛癣菌的PQ-LRP同源性达到81%,与红色毛癣菌PQ-LRP同源性达到79%.结论 克隆出犬小孢子菌膜蛋白PQ-LRP cDNA全长序列,为研究膜蛋白PQ-LRP基因在犬小孢子菌病中的功能奠定基础.

  4. Heterogeneity of cag genotypes of Helicobacter pylori in the esophageal mucosa of dyspeptic patients and its relation to histopathological outcomes

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    Monica Contreras

    2014-09-01

    Conclusions: H. pylori may coexist in similar proportions without dominance of one cag genotype, suggesting a heterogeneous distribution in the esophagus. The cagE and virB11 genes can be used as markers of cag-PAI in the esophagus. The single cag-PAI genotype in both mucosae confers an increased risk of developing histological damage.

  5. Genomes of Helicobacter pylori from native Peruvians suggest admixture of ancestral and modern lineages and reveal a western type cag-pathogenicity island

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    Rahman Syed

    2006-07-01

    Full Text Available Abstract Background Helicobacter pylori is presumed to be co-evolved with its human host and is a highly diverse gastric pathogen at genetic levels. Ancient origins of H. pylori in the New World are still debatable. It is not clear how different waves of human migrations in South America contributed to the evolution of strain diversity of H. pylori. The objective of our 'phylogeographic' study was to gain fresh insights into these issues through mapping genetic origins of H. pylori of native Peruvians (of Amerindian ancestry and their genomic comparison with isolates from Spain, and Japan. Results For this purpose, we attempted to dissect genetic identity of strains by fluorescent amplified fragment length polymorphism (FAFLP analysis, multilocus sequence typing (MLST of the 7 housekeeping genes (atpA, efp, ureI, ppa, mutY, trpC, yphC and the sequence analyses of the babB adhesin and oipA genes. The whole cag pathogenicity-island (cagPAI from these strains was analyzed using PCR and the geographic type of cagA phosphorylation motif EPIYA was determined by gene sequencing. We observed that while European genotype (hp-Europe predominates in native Peruvian strains, approximately 20% of these strains represent a sub-population with an Amerindian ancestry (hsp-Amerind. All of these strains however, irrespective of their ancestral affiliation harbored a complete, 'western' type cagPAI and the motifs surrounding it. This indicates a possible acquisition of cagPAI by the hsp-Amerind strains from the European strains, during decades of co-colonization. Conclusion Our observations suggest presence of ancestral H. pylori (hsp-Amerind in Peruvian Amerindians which possibly managed to survive and compete against the Spanish strains that arrived to the New World about 500 years ago. We suggest that this might have happened after native Peruvian H. pylori strains acquired cagPAI sequences, either by new acquisition in cag-negative strains or by recombination

  6. Comparison of a PCR-restriction fragment length polymorphism (PCR-RFLP) assay to pulsed-field gel electrophoresis to determine the effect of repeated subculture and prolonged storage on RFLP patterns of Shiga toxin-producing Escherichia coli O157:H7.

    Science.gov (United States)

    Shima, Kensuke; Wu, Yuluo; Sugimoto, Norihiko; Asakura, Masahiro; Nishimura, Kazuhiko; Yamasaki, Shinji

    2006-11-01

    In this study, we compared a recently developed PCR-restriction fragment length polymorphism (PCR-RFLP) assay with pulsed-field gel electrophoresis (PFGE) using three different Shiga toxin-producing Escherichia coli (STEC) strains to understand whether repeated subculture in vitro and prolonged storage at room temperature affect the RFLP patterns of STEC. The PFGE profiles of the STEC strains changed by 1 to 8 fragments after repeated subculture and prolonged storage; one strain was no longer clonal after repeated subculture compared to the original isolate according to the Tenover criteria. In contrast, RFLP patterns obtained by PCR-RFLP were identical after repeated subculture and prolonged storage. These data clearly indicate that the PCR-RFLP assay which is based on the diversity of region V, a regulatory region of Stx-phage, was not affected by repeated subculture and prolonged storage and is a more practical and reliable method for molecular typing of STEC strains.

  7. Absence of MutSβ leads to the formation of slipped-DNA for CTG/CAG contractions at primate replication forks.

    Science.gov (United States)

    Slean, Meghan M; Panigrahi, Gagan B; Castel, Arturo López; Pearson, August B; Tomkinson, Alan E; Pearson, Christopher E

    2016-06-01

    Typically disease-causing CAG/CTG repeats expand, but rare affected families can display high levels of contraction of the expanded repeat amongst offspring. Understanding instability is important since arresting expansions or enhancing contractions could be clinically beneficial. The MutSβ mismatch repair complex is required for CAG/CTG expansions in mice and patients. Oddly, by unknown mechanisms MutSβ-deficient mice incur contractions instead of expansions. Replication using CTG or CAG as the lagging strand template is known to cause contractions or expansions respectively; however, the interplay between replication and repair leading to this instability remains unclear. Towards understanding how repeat contractions may arise, we performed in vitro SV40-mediated replication of repeat-containing plasmids in the presence or absence of mismatch repair. Specifically, we separated repair from replication: Replication mediated by MutSβ- and MutSα-deficient human cells or cell extracts produced slipped-DNA heteroduplexes in the contraction- but not expansion-biased replication direction. Replication in the presence of MutSβ disfavoured the retention of replication products harbouring slipped-DNA heteroduplexes. Post-replication repair of slipped-DNAs by MutSβ-proficient extracts eliminated slipped-DNAs. Thus, a MutSβ-deficiency likely enhances repeat contractions because MutSβ protects against contractions by repairing template strand slip-outs. Replication deficient in LigaseI or PCNA-interaction mutant LigaseI revealed slipped-DNA formation at lagging strands. Our results reveal that distinct mechanisms lead to expansions or contractions and support inhibition of MutSβ as a therapeutic strategy to enhance the contraction of expanded repeats.

  8. Helicobacter pylori CagA disrupts epithelial patterning by activating myosin light chain.

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    Jonathan B Muyskens

    Full Text Available Helicobacter pylori infection is a leading cause of ulcers and gastric cancer. We show that expression of the H. pylori virulence factor CagA in a model Drosophila melanogaster epithelium induces morphological disruptions including ectopic furrowing. We find that CagA alters the distribution and increases the levels of activated myosin regulatory light chain (MLC, a key regulator of epithelial integrity. Reducing MLC activity suppresses CagA-induced disruptions. A CagA mutant lacking EPIYA motifs (CagA(EPISA induces less epithelial disruption and is not targeted to apical foci like wild-type CagA. In a cell culture model in which CagA(EPISA and CagA have equivalent subcellular localization, CagA(EPISA is equally potent in activating MLC. Therefore, in our transgenic system, CagA is targeted by EPIYA motifs to a specific apical region of the epithelium where it efficiently activates MLC to disrupt epithelial integrity.

  9. Instability of trinucleotidic repeats during chromatin remodeling in spermatids.

    Science.gov (United States)

    Simard, Olivier; Grégoire, Marie-Chantal; Arguin, Mélina; Brazeau, Marc-André; Leduc, Frédéric; Marois, Isabelle; Richter, Martin V; Boissonneault, Guylain

    2014-11-01

    Transient DNA breaks and evidence of DNA damage response have recently been reported during the chromatin remodeling process in haploid spermatids, creating a potential window of enhanced genetic instability. We used flow cytometry to achieve separation of differentiating spermatids into four highly purified populations using transgenic mice harboring 160 CAG repeats within exon 1 of the human Huntington disease gene (HTT). Trinucleotic repeat expansion was found to occur immediately following the chromatin remodeling steps, confirming the genetic instability of the process and pointing to the origin of paternal anticipation observed in some trinucleotidic repeats diseases.

  10. Isolation and characterization of human brain genes with (CCA){sub n} trinucleotide repeats

    Energy Technology Data Exchange (ETDEWEB)

    Longshore, J.W.; Finley, W.H.; Descartes, M. [Univ. of Alabama, Birmingham, AL (United States)] [and others

    1994-09-01

    Expansion of trinucleotide repeats has been described as a new form of mutation. To date, only the expansion of (CGG){sub n} and (CAG){sub n} repeats have been associated with disease. Expansion of (CAG){sub n} repeats has been found to cause Huntington`s disease, Kennedy`s disease, myotonic dystrophy, spinocerebellar ataxia type 1, and dentatorubral pallidoluysian atrophy. (CGG){sub n} repeat expansion has been implicated in the fragile X syndrome and FRAXE mental retardation. In an effort to identify other potential repeats as candidates for expansion, a DNA linguistics approach was used to study 10 Mb of human DNA sequences in GenBank. Our study found the (CCA){sub n} repeat and the disease-associated (CGG){sub n} and (CAG){sub n} repeats to be over-represented in the human genome. The (CCA){sub n} repeat also shares other characteristics with (CGG){sub n} and (CAG){sub n}, making it a good candidate for expansion. Trinucleotide repeat numbers in disease-associated genes are normally polymorphic in a population. Therefore, by studying genes for polymorphisms, candidate genes may be identified. Twelve sequences previously deposited in GenBank with at least five tandem copies of (CCA) were studied and no polymorphisms were found. To identify other candidate genes, a human hippocampus cDNA library was screened with a (CCA){sub 8} probe. This approach identified 19 novel expressed sequences having long tandem (CCA){sub n} repeats which are currently under investigation for polymorphisms. Genes with polymorphic repeats may serve as markers for linkage studies or as candidate genes for genetic diseases showing anticipation.

  11. Outcomes of CAG Regimen for Refractory Biphenotypic Acute Leukemia Patients

    Institute of Scientific and Technical Information of China (English)

    Guang-sheng He; Xiang Zhang; De-pei Wu; Ai-ning Sun; Zheng-ming Jin; Hui-ying Qiu; Miao Miao; Xiao-wen Tang; Zheng-zheng Fu; Yue Han

    2009-01-01

    Objective To evaluated the efficiency of low-dose cytosine arabinoside plus aclarubicin with concurrent administration of granulocyte colony-stimulating factor(CAG)regimen for refractory biphenotypic acute leukemia(BAL).Methods We treated 5 refractory BAL patients by CAG regimen(10 mg·m 2 cytosine arabinoside subcutaneously administrated every 12 hours,day 1-14;5-7 mg·m2 aclarubicin intravenously administrated daily,day 1-8;and concurrently used 200 μg.m-2·d-1 granulocyte colony-stimulating factor subcutaneously)from November 2002 to April 2007.The efficacy of the regimen was evaluated by response rate,and the side effects were also measured.Results The complete remission rate was 80% ,median duration of absolute neutrophil count<5.0×108/L and platelet count<2.0×1010/L was day 13 and day 1,respectively;and the infection rate was low(Ⅲ-Ⅳ infection rate,20.00% ).Conclusion CAG regimen as remission induction chemotherapy for BAL patients is effective with a high remission rate and low toxicity.

  12. Ataxin-2 intermediate-length polyglutamine: a possible risk factor for Chinese patients with amyotrophic lateral sclerosis.

    Science.gov (United States)

    Chen, Yongping; Huang, Rui; Yang, Yuan; Chen, Ke; Song, Wei; Pan, Pinglei; Li, Jianpeng; Shang, Hui-Fang

    2011-10-01

    Intermediate-length polyglutamine (polyQ) expansions in the ataxin-2 (ATXN2) gene have recently been identified as a risk factor for sporadic amyotrophic lateral sclerosis (SALS). Our study aims to analyze cytosine, adenine, guanine (CAG)n expansions in the ATXN2 gene among Chinese patients with SALS. All patients diagnosed with adult-onset sporadic amyotrophic lateral sclerosis (ALS) were consecutively followed up, and their clinical characteristics were collected. To measure the repeat length of ATXN2 polyQ, fluorescence-polymerase chain reaction products were analyzed on a 3100-Avant Genetic Analyzer Applied Biosystem (Foster City, CA, USA) using the ROC-500 size standard. Three hundred forty-five patients with SALS were studied. The mean age of onset was 51.38 ± 12.45 years. ATXN2 polyQ with a repeat length greater than 27 was found to be weakly associated with amyotrophic lateral sclerosis in our study. There was no significant difference in mean age of onset, gender, and onset site between the group of SALS patients with and without ATXN2 polyQ expansion greater than 27. Our finding provides evidence that the ATXN2 polyQ expansion greater than 27 might be a risk factor for Chinese SALS patients.

  13. Larger trinucleotide repeat size in the androgen receptor gene of infertile men with extremely severe oligozoospermia.

    Science.gov (United States)

    Patrizio, P; Leonard, D G; Chen, K L; Hernandez-Ayup, S; Trounson, A O

    2001-01-01

    Androgens are significant regulators of human spermatogenesis. Their action is mediated through the androgen receptor (AR), which binds to the androgen responsive element on DNA and regulates gene transcription. Men become infertile with spinobulbar muscular atrophy (Kennedy disease) caused by a trinucleotide repeat expansion, > or = 40 CAG repeats, in the AR gene located on the X chromosome. In this prospective study, we investigated whether the variable size, larger repeats, of this trinucleotide could alter AR function and result in impaired spermatogenesis. A total of 69 infertile men were studied. Clinical and laboratory analysis showed idiopathic, nonobstructive azoospermia in 16 men, extremely severe oligozoospermia in 27 men (PCR) amplification across the AR repeat region. Accurate size determination of the PCR product using an ABI 373 DNA sequencer allowed precise calculation of CAG repeat sizes. The AR gene was not analyzed for other types of mutations. The difference in CAG repeat size between infertile men and proven fertile controls was statistically significant, P = .03. Patients with extremely severe oligozoospermia had significantly longer CAG repeat tracts (mean, 25.4 +/- 4.0; P = .0005; range 20-39) than controls (mean, 22 +/- 2.8; range 12-30) or patients with severe oligozoospermia (mean, 22.2 +/- 2.3; range 18-26). None of the 26 infertile men with sperm counts CAG repeats compared with 6 out of 45 controls (13%; P = .06). This study suggests that some men with severe impairment of spermatogenesis have longer trinucleotide repeats in the AR gene. Although direct evidence is missing, lower affinity between androgen and the AR protein or decreased AR protein availability with longer repeats could be responsible for a diminished androgen effect on spermatogenesis. Two of the patients in the extremely severe oligozoospermia group had 35 and 39 CAG repeats, respectively (normal range is 11 to 33). Although not yet considered a mutation, longer

  14. A new polymerase chain reaction (PCR) assay for the trinucleotide repeat that is unstable and expanded on Huntington's disease chromosomes.

    Science.gov (United States)

    Warner, J P; Barron, L H; Brock, D J

    1993-06-01

    The Huntington's Disease (HD) Collaborative Research Group has recently published the sequence of a new cDNA, IT15, containing a polymorphic trinucleotide (CAG)n repeat that is expanded and unstable on HD chromosomes. There is a correlation between the repeat size and the age of onset of symptoms. The suggested polymerase chain reaction (PCR) assay of the (CAG)n repeat requires unusual reaction components and primer concentrations and the use of 5% polyacrylamide sequencing gels to resolve the amplification products. We present a simple PCR assay that produces a smaller product using standard reaction conditions. This gives better resolution of the (CAG)n expansion observed on HD chromosomes by acrylamide gel electrophoresis and allows sufficient product to be obtained to perform assays using agarose gels. This will allow diagnostic labs to do rapid and accurate presymptomatic testing of HD in high risk families.

  15. Helicobacter pylori CagA protein polymorphisms and their lack of association with pathogenesis

    Institute of Scientific and Technical Information of China (English)

    Nicole; Acosta; Andrés; Quiroga; Pilar; Delgado; María; Mercedes; Bravo; Carlos; Jaramillo

    2010-01-01

    AIM: To investigate Helicobacter pylori (H. pylori) CagA diversity and to evaluate the association between protein polymorphisms and the occurrence of gastric pathologies. METHODS: One hundred and twenty-two clinical isolates of H. pylori cultured from gastric biopsies obtained from Colombian patients with dyspepsia were included as study material. DNA extracted from isolates was used to determine cagA status, amplifying the C-terminal cagA gene region by polymerase chain reaction. One hundred and six strai...

  16. Roles of the nucleolus in the CAG RNA-mediated toxicity.

    Science.gov (United States)

    Tsoi, Ho; Chan, Ho Yin Edwin

    2014-06-01

    The nucleolus is a subnuclear compartment within the cell nucleus that serves as the site for ribosomal RNA (rRNA) transcription and the assembly of ribosome subunits. Apart from its classical role in ribosomal biogenesis, a number of cellular regulatory roles have recently been assigned to the nucleolus, including governing the induction of apoptosis. "Nucleolar stress" is a term that is used to describe a signaling pathway through which the nucleolus communicates with other subcellular compartments, including the mitochondria, to induce apoptosis. It is an effective mechanism for eliminating cells that are incapable of performing protein synthesis efficiently due to ribosome biogenesis defects. The down-regulation of rRNA transcription is a common cause of nucleolar function disruption that subsequently triggers nucleolar stress, and has been associated with the pathogenesis of neurological disorders such as spinocerebellar ataxias (SCAs) and Huntington's diseases (HD). This article discusses recent advances in mechanistic studies of how expanded CAG trinucleotide repeat RNA transcripts trigger nucleolar stress in SCAs, HD and other trinucleotide repeat disorders. This article is part of a Special Issue entitled: Role of the Nucleolus in Human Disease.

  17. Helicobacter pylori CagA Inhibits PAR1-MARK Family Kinases by Mimicking Host Substrates

    Energy Technology Data Exchange (ETDEWEB)

    Nesic, D.; Miller, M; Quinkert, Z; Stein, M; Chait, B; Stebbins, C

    2010-01-01

    The CagA protein of Helicobacter pylori interacts with numerous cellular factors and is associated with increased virulence and risk of gastric carcinoma. We present here the cocrystal structure of a subdomain of CagA with the human kinase PAR1b/MARK2, revealing that a CagA peptide mimics substrates of this kinase family, resembling eukaryotic protein kinase inhibitors. Mutagenesis of conserved residues central to this interaction renders CagA inactive as an inhibitor of MARK2.

  18. A positive assay for identification of cagA negative strains of Helicobacter pylori.

    Science.gov (United States)

    Sicinschi, Liviu A; Correa, Pelayo; Bravo, Luis E; Schneider, Barbara G

    2003-12-01

    A new PCR protocol was developed for the positive identification of cagA negative Helicobacter pylori strains. Amplification of a portion of the genome across the insertion point of the cag pathogenicity island (the ES-"empty site") generated a 106-bp fragment, which produces a positive signal for cagA negative strains. Combined with the results of the cagA assay, the signals for ES allowed the complete characterization of the patients' cagA status. DNA sequencing analysis confirmed the identity of the ES fragment. The new protocol and cagA assay were applied to 22 DNA preparations isolated from stools from H. pylori infected adult patients and to 21 DNA preparations isolated from stools from H. pylori infected children. The same analysis was also performed on nine colonies of H. pylori derived from gastric biopsies of nine of the adult patients. The total number of cagA positive cases from adult patients was 14 or 63.6% (11 mono- and 3 mixed) and of the cagA negative cases (or ES positive) was 9 or 40.9% (6 mono- and 3 mixed). Of the 21 stool DNA samples from children, 6 (28.6%) were cagA positive, 12 (57.1%) were cagA negative and 3 (14.3%) were positive for cagA and for the ES simultaneously. The proportions of mixed cagA positive and cagA negative H. pylori infections were almost equal in adults and children (13.6% and 14.3%, respectively). No reaction products of the proper fragment sizes for cagA or the empty site (ES) were obtained from any of the stool DNA samples of 10 H. pylori uninfected subjects (100% specificity). This noninvasive assay discriminates consistently cagA negative cases from cagA positive strains and from amplification failures. It can be a useful tool for clinical and epidemiological studies of H. pylori infection.

  19. Mappability and Read Length

    Directory of Open Access Journals (Sweden)

    Wentian eLi

    2014-11-01

    Full Text Available Power-law distributions are the main functional form forthe distribution of repeat size and repeat copy number in the human genome. When the genome is broken into fragments for sequencing, the limited size offragments and reads may prevent an unique alignment of repeatsequences to the reference sequence. Repeats in the human genome canbe as long as $10^4$ bases, or $10^5-10^6$ bases when allowing for mismatches between repeat units. Sequence reads from these regions are therefore unmappable when the read length is in the range of $10^3$ bases.With the read length of exactly 1000 bases, slightly more than 1% of theassembled genome, and slightly less than 1% of the 1kbreads, are unmappable, excluding the unassembled portion of the humangenome (8% in GRCh37. The slow decay (long tail ofthe power-law function implies a diminishing return in convertingunmappable regions/reads to become mappable with the increase of theread length, with the understanding that increasing read length willalways move towards the direction of 100% mappability.

  20. Anthropometry in Klinefelter syndrome - multifactorial influences due to CAG length, testosterone treatment and possibly intrauterine hypogonadism

    DEFF Research Database (Denmark)

    Chang, Simon; Skakkebæk, Anne; Trolle, Christian;

    2015-01-01

    Context: Klinefelter syndrome, 47, XXY (KS), is underdiagnosed partly due to few clinical signs complicating identification of affected individuals. Certain phenotypic traits are common in KS. However, not all aspects of the KS phenotype are well described. Objective: To describe anthropometry...

  1. Trinucleotide repeat expansion and DRPLA (Smith`s disease): Molecular characterization of atrophin-1

    Energy Technology Data Exchange (ETDEWEB)

    Margolis, R.L.; Li, S.H.; Li, X.J.; Ross, C.A. [Johns Hopkins Univ., Balitmore, MD (United States)

    1994-09-01

    Smith`s disease (also known as dentatorubral pallidoluysian atrophy or DRPLA) is a rare, progressive, fatal neuropsychiatric disorder similar to Huntington`s disease (HD). Smith`s disease is characterized by ataxia, choreoathetosis, myoclonic epilepsy, dementia, and genetic anticipation. Neuropathological findings include prominent cell loss in the dentate nucleus of the cerebellum, the globus pallidus, the red nucleus, and the subthalamic nucleus. An expansion of a CAG trinucleotide repeat encoding polyglutamine in a gene originally identified in our laboratory as part of a program to clone candidate genes for disorders with anticipation has recently been found to cause this disorder. We have identified two families that demonstrate the pathological and genetic features (expanded CAG repeat and anticipation) of this disease. Northern analysis indicates that the gene, which we have termed atrophin-1, is widely expressed as a 5 kb mRNA in normal human brain and peripheral tissues. Brain expression is highest in the cerebellum. The developmental expression of the rat homologues of IT-15 (the gene in which a CAG expansion causes HD) and atrophin-1 were compared. Atrophin-1 was most highly expressed in early rat embryo brain (E16), whereas the greatest expression of IT-15 was in the adult rat brain. Cloning and sequencing of the open reading frame from inserts contained in brain cDNA libraries is in progress. In addition to the CAG repeat, the ORF contains an unusual region of alternating acidic and basic amino acids. Further characterization of atrophin-1, and comparison of it to other genes in which trinucleotide repeat expansion leads to neuropsychiatric disorders, should lead to a better understanding of the pathophysiology by which CAG repeat expansion causes human disease.

  2. Crystal structure of the type IV secretion system component CagX from Helicobacter pylori

    Science.gov (United States)

    Zhang, Jin; Fan, Fei; Zhao, Yanhe; Sun, Lifang; Liu, Yadan; Wu, Yunkun

    2017-01-01

    Helicobacter pylori, a Gram-negative bacterial pathogen prevalent in the human population, is the causative agent of severe gastric diseases. An H. pylori type IV secretion (T4S) system encoded by the cytotoxin-associated gene pathogenicity island (cagPAI) is responsible for communication with host cells. As a component of the cagPAI T4S system core complex, CagX plays an important role in virulence-protein translocation into the host cells. In this work, the crystal structure of the C-terminal domain of CagX (CagXct), which is a homologue of the VirB9 protein from the VirB/D4 T4S system, is presented. CagXct is only the second three-dimensional structure to be elucidated of a VirB9-like protein. Another homologue, TraO, which is encoded on the Escherichia coli conjugative plasmid pKM101, shares only 19% sequence identity with CagXct; however, there is a remarkable similarity in tertiary structure between these two β-sandwich protein domains. Most of the residues that are conserved between CagXct and TraO are located within the protein core and appear to be responsible for the preservation of this domain fold. The studies presented here will contribute to our understanding of different bacterial T4S systems. PMID:28291753

  3. Helicobacter pylori and CagA under conditions of iron deficiency.

    Science.gov (United States)

    Noto, Jennifer M; Peek, Richard M

    2015-01-01

    Iron deficiency is the most common nutritional deficiency worldwide and compelling evidence has demonstrated that this condition heightens the risk of gastric cancer. Infection with Helicobacter pylori is the strongest known risk factor for the development of gastric adenocarcinoma. Recent work has demonstrated that, under conditions of iron deficiency, H. pylori-induced gastric carcinogenesis is augmented through increased formation of the strain-specific cag type IV secretion system and enhanced delivery of the bacterial oncoprotein CagA into host cells. Although CagA is a potent virulence factor that promotes oncogenic responses, additional studies have now demonstrated that CagA modulates host cell iron homeostasis in vitro and fundamental metabolic functions of the bacterial cell in vivo. Here we discuss these findings and describe working models by which CagA exerts its effects on gastric epithelial cells, with particular emphasis on its potential role in modulation of host iron homeostasis.

  4. 幽门螺杆菌cagA基因和血清CagA抗体与VacA表达关系的研究

    Institute of Scientific and Technical Information of China (English)

    张尤历; 刘厚钰; 等

    1999-01-01

    目的;探讨幽门螺杆菌cagA基因和血清CagA抗体与VacA表达的关系。方法:用聚合酶链反应法(PCR)测定由62例慢性胃炎、消化性溃疡和胃癌患者胃罕粘膜分离获得Hp菌株:用酶免疫技术测定患者血清HpCagA抗体;用Hela细胞培养法测定Hp菌株VacA活性。结果:cagA基因阳性和阴性Hp菌株表达VacA阳必班组分别为40.00%和33.33%(P>0.05);血清CagA抗体阳性和阴性患者感染Hp菌株体外产生VacA阳性率分别为33.33%和42.11%(P>0.05)。结论:HpcagA基因和血清CagA抗体与VacA表达之间无相互依赖关系,vacA基因是一个独立的标志物。

  5. Relation of CagA+ helicobacter pylori with gastroduodenal disorders%CagA+幽门螺杆菌与上消化道疾病的关系

    Institute of Scientific and Technical Information of China (English)

    贾凯; 王世鑫

    2001-01-01

    目的:探讨细胞毒素相关蛋白(Cytotoxin Associated Protein , CagA)阳性株幽门螺杆菌感染在胃、十二指肠疾病的发生中的意义.方法:分别观察34例慢性胃炎患者、28例消化性溃疡患者幽门螺杆菌的感染情况及CagA基因的阳性率,并与30例正常人群做了对比研究.结果:28例消化性溃疡患者Hp感染率为92.9%,CagA基因的阳性率为96.2%;34例慢性胃炎患者Hp感染率为91.2%,CagA基因的阳性率为51.6%;30例正常人群Hp感染率为53.3%,CagA基因的阳性率为6.25%;3组数据比较有明显差异(P<0.05).结论:CagA+幽门螺杆菌在胃、十二指肠炎症及溃疡发病中起重要作用,应采用必要的治疗措施.

  6. Triplet repeat primed PCR simplifies testing for Huntington disease.

    Science.gov (United States)

    Jama, Mohamed; Millson, Alison; Miller, Christine E; Lyon, Elaine

    2013-03-01

    Diagnostic and predictive testing for Huntington disease (HD) requires an accurate determination of the number of CAG repeats in the Huntingtin (HHT) gene. Currently, when a sample appears to be homozygous for a normal allele, additional testing is required to confirm amplification from both alleles. If the sample still appears homozygous, Southern blot analysis is performed to rule out an undetected expanded HTT allele. Southern blot analysis is expensive, time-consuming, and labor intensive and requires high concentrations of DNA. We have developed a chimeric PCR process to help streamline workflow; true homozygous alleles are easily distinguished by this simplified method, and only very large expanded alleles still require Southern blot analysis. Two hundred forty-six HD samples, previously run with a different fragment analysis method, were analyzed with our new method. All samples were correctly genotyped, resulting in 100% concordance between the methods. The chimeric PCR assay was able to identify expanded alleles up to >150 CAG repeats. This method offers a simple strategy to differentiate normal from expanded CAG alleles, thereby reducing the number of samples reflexed to Southern blot analysis. It also provides assurance that expanded alleles are not routinely missed because of allele dropout.

  7. Serum oxidative stress status in CagA positive Helicobacter pylori infection

    Directory of Open Access Journals (Sweden)

    Zeynep Çizmeci

    2011-06-01

    Full Text Available Previous studies have suggested that CagA positive Helicobacter pylori (H.pylori infection may cause the various oxidative damages. The objective of this study was to investigate serum oxidative status in infectetion with CagA positive H.pylori strains.Materials and methods: Forty-two H.pylori CagA positive subjects and 39 H.pylori CagA negative subjects were enrolled. H.pylori infection was diagnosed by the histopathological assessment of gastric mucosa. CagA status was detected by enzyme immuno assay in a micro ELISA machine. Total antioxidant status (TAS and total oxidant status (TOS were measured autoanalyzer using commercially available kits. Serum oxidative stress index (OSI was calculated using TAS and TOS measurements.Results: The levels TAS and TOS of CagA positive subjects were found to be 1.48 ± 0.18 mmol/L, 36.88 ± 19.84 mmol/L. Those of CagA negative group were measured to be 1.43 ± 0.19 mmol/L and 38.44 ± 14.72 mmol/L respectively. The values of serum OSI were similar (25.28 ± 15.85 and 26.48 ± 10.02 in CagA positive and negative groups.Conclusions: The measurements of serum oxidative status did not show any sigficant difference between the patients infected with CagA positive and CagA negative H.pilori strains. J Clin Exp Invest 2011;2(2:202-6

  8. Repeat associated non-ATG translation initiation: one DNA, two transcripts, seven reading frames, potentially nine toxic entities!

    Directory of Open Access Journals (Sweden)

    Christopher E Pearson

    2011-03-01

    Full Text Available Diseases associated with unstable repetitive elements in the DNA, RNA, and amino acids have consistently revealed scientific surprises. Most diseases are caused by expansions of trinucleotide repeats, which ultimately lead to diseases like Huntington's disease, myotonic dystrophy, fragile X syndrome, and a series of spinocerebellar ataxias. These repeat mutations are dynamic, changing through generations and within an individual, and the repeats can be bi-directionally transcribed. Unsuspected modes of pathogenesis involve aberrant loss of protein expression; aberrant over-expression of non-mutant proteins; toxic-gain-of-protein function through expanded polyglutamine tracts that are encoded by expanded CAG tracts; and RNA-toxic-gain-of-function caused by transcripts harboring expanded CUG, CAG, or CGG tracts. A recent advance reveals that RNA transcripts with expanded CAG repeats can be translated in the complete absence of a starting ATG, and this Repeat Associated Non-ATG translation (RAN-translation occurs across expanded CAG repeats in all reading frames (CAG, AGC, and GCA to produce homopolymeric proteins of long polyglutamine, polyserine, and polyalanine tracts. Expanded CTG tracts expressing CUG transcripts also show RAN-translation occurring in all three frames (CUG, UGC, and GCU, to produce polyleucine, polycysteine, and polyalanine. These RAN-translation products can be toxic. Thus, one unstable (CAG•(CTG DNA can produce two expanded repeat transcripts and homopolymeric proteins with reading frames (the AUG-directed polyGln and six RAN-translation proteins, yielding a total of potentially nine toxic entities. The occurrence of RAN-translation in patient tissues expands our horizons of modes of disease pathogenesis. Moreover, since RAN-translation counters the canonical requirements of translation initiation, many new questions are now posed that must be addressed. This review covers RAN-translation and some of the pertinent

  9. Telomeric repeat factor 1 protein levels correlates with telomere length in colorectal cancer Los niveles proteicos del factor de repetición telomérico 1 se correlacionan con la longitud del telómero en el cáncer colorrectal

    Directory of Open Access Journals (Sweden)

    Cristina Valls-Bautista

    2012-11-01

    Full Text Available Background: colorectal cancer is the third cancer cause of death in Spain. It is important to investigate new tumoral markers for early diagnosis, disease monitoring and prevention strategies. Telomeres protect the chromosome from degradation by nucleases and end-to-end fusion. The progressive loss of the telomeric ends of chromosomes is an important mechanism in the timing of human cellular aging. Telomeric Repeat Factor 1 (TRF1 is a protein that binds at telomere ends. Purpose: to measure the concentrations of TRF1 and the relationships among telomere length, telomerase activity, and TRF1 levels in tumor and normal colorectal mucosa. Method: from normal and tumoral samples of 83 patients who underwent surgery for colorectal cancer we analyzed TRF1 protein concentration by Western Blot, telomerase activity, by the fluorescent-telomeric repeat amplification protocol assay and telomere length by Southern Blot. Results: high levels of TRF1 were observed in 68.7% of tumor samples, while the majority of normal samples (59% showed negative or weak TRF1 concentrations. Among the tumor samples, telomere length was significantly associated with TRF1 protein levels (p = 0.023. Conclusions: a relationship was found between telomere length and TRF1 abundance protein in tumor samples, which means that TRF1 is an important factor in the tumor progression and maybe a diagnostic factor.

  10. Prevalence of cagA EPIYA motifs in Helicobacter pylori among dyspeptic patients in northeast Thailand.

    Science.gov (United States)

    Chomvarin, Chariya; Phusri, Karnchanawadee; Sawadpanich, Kookwan; Mairiang, Pisaln; Namwat, Wises; Wongkham, Chaisiri; Hahnvajanawong, Chariya

    2012-01-01

    The aims of this study were to determine the prevalence of cagA type in Helicobacter pylori isolated from dyspeptic patients in northeastern Thailand and to determine whether the pattern of cagA EPIYA motifs were associated with clinical outcomes. One hundred and forty-seven H. pylori-infected dyspeptic patients were enrolled, of whom 68 had non-ulcer dyspepsia (NUD), 57 peptic ulcer disease (PUD), 18 gastric cancer (GCA), and 4 other gastroduodenal diseases. PCR and DNA sequence analysis were used to determine the cagA genotype and the pattern of EPIYA motifs. cagA-positive H. pylori were identified in 138 (94%) of H. pylori-infected dyspeptic patients of whom 75 (54%) were of the Western-type, 44 (32%) the East Asian type and 19 (14%) of the other types. The Western type is significantly found in PUD patients (p = 0.0175). The majority of cagA EPIYA was EPIYA-ABC (43%) and EPIYA-ABD (28%). There is no significant correlation between the increase in number of EPIYA-C motifs and clinical outcomes. Thus, the most frequent cagA type found among northeastern Thai dyspeptic patients was the Western cagA type, which is significantly associated with PUD indicating a possible predictive parameter for clinical outcome.

  11. Cloning and sequencing of cagA gene fragment of Helicobacter pylori with coccoid form

    Institute of Scientific and Technical Information of China (English)

    Ke-Xia Wang; Xue-Feng Wang

    2004-01-01

    AIM: To clone and sequence the cagA gene fragment of Helicobacter pylori ( H pylori) with coccoid form.METHODS: H pylori strain NCTC11637 were transformed to coccoid form by exposure to antibiotics in subinhibitory concentrations. The coccoid H pyloriwas collected. cagA gene of the coccoid H pylori strain was amplified by PCR.After purified, the target fragment was cloned into plasmid pMD-18T. The recombinant plasmid pMD-18T-cagA was transformed into E. coli JM109. Positive clones were screened and identified by PCR and digestion with restriction endonucleases. The sequence of inserted fragment was then analysed.RESULTS: cagA gene of 3 444 bp was obtained from the coccoid H pylori genome DNA. The recombinant plasmid pMD-18T-cagA was constructed, then it was digested by BamH Ⅰ+Sac Ⅰ, and the product of digestion was identical with the predicted one. Sequence analysis showed that the homology of coccoid and the reported original sequence H pylori was 99.7%.CONCLUSION: The recombinant plasmid containing cagA gene from coccoid H pylori has been constructed successfully.The coccoid H pylori contain completed cagA gene, which may be related to pathogenicity of them.

  12. Inhibition of Helicobacter pylori CagA-Induced Pathogenesis by Methylantcinate B from Antrodia camphorata

    Directory of Open Access Journals (Sweden)

    Chun-Jung Lin

    2013-01-01

    Full Text Available The bacterial pathogen Helicobacter pylori (Hp is the leading risk factor for the development of gastric cancer. Hp virulence factor, cytotoxin-associated gene A (CagA interacted with cholesterol-enriched microdomains and leads to induction of inflammation in gastric epithelial cells (AGS. In this study, we identified a triterpenoid methylantcinate B (MAB from the medicinal mushroom Antrodia camphoratawhich inhibited the translocation and phosphorylation of CagA and caused a reduction in hummingbird phenotype in HP-infected AGS cells. Additionally, MAB suppressed the Hp-induced inflammatory response by attenuation of NF-κB activation, translocation of p65 NF-κB, and phosphorylation of IκB-α, indicating that MAB modulates CagA-mediated signaling pathway. Additionally, MAB also suppressed the IL-8 luciferase activity and its secretion in HP-infected AGS cells. On the other hand, molecular structure simulations revealed that MAB interacts with CagA similarly to that of cholesterol. Moreover, binding of cholesterol to the immobilized CagA was inhibited by increased levels of MAB. Our results demonstrate that MAB is the first natural triterpenoid which competes with cholesterol bound to CagA leading to attenuation of Hp-induced pathogenesis of epithelial cells. Thus, this study indicates that MAB may have a scope to develop as a therapeutic candidate against Hp CagA-induced inflammation.

  13. Flame Length

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Flame length was modeled using FlamMap, an interagency fire behavior mapping and analysis program that computes potential fire behavior characteristics. The tool...

  14. Expression of the CagA gene of H. pylori and application of its product

    Institute of Scientific and Technical Information of China (English)

    Feng Chan Han; Xiao Jun Yan; Cheng Zhi Su

    2000-01-01

    @@ INTRODUCTION Helicobacter pylori (Hp) plays an important role in the upper digestive tract diseases. It can be divided into two main groups (toxic and non-toxic Hp )according to the production of vacuolating cytotoxin (VacA). The toxic bacteria also produce cytotoxin associated protein A (CagA) which might have something to do with the transcription, folding,transportation or the function of VacA. Studies showed that CagA positive Hp ( CagA+ Hp )accounted for more than 50% of all kinds of Hp,and peptic ulcer and gastric cancer were closely related to their infection[1-7].

  15. Burden of Hospital Admission and Repeat Angiography in Angina Pectoris Patients with and without Coronary Artery Disease

    DEFF Research Database (Denmark)

    Jespersen, Lasse; Abildstrom, Steen Z; Hvelplund, Anders

    2014-01-01

    AIMS: To evaluate risk of hospitalization due to cardiovascular disease (CVD) and repeat coronary angiography (CAG) in stable angina pectoris (SAP) with no obstructive coronary artery disease (CAD) versus obstructive CAD, and asymptomatic reference individuals. METHODS AND RESULTS: We followed 11...

  16. [Comparison of clinical efficacy between decitabine combined with CAG regimen and CAG regimen alone in patients with intermediate to high-risk myelodysplastic syndromes].

    Science.gov (United States)

    Zhang, Yun-Ping; Wu, Wen-Zhong; Cui, Guo-Xing

    2014-10-01

    This study was purposed to compare the clinical efficacy and adverse reactions of low-dose decitabine combined with CAG regimen (aclarubicin, Ara-C, and G-CSF) and CAG regimen alone in intermediate to high-risk myelodysplastic syndromes (MDS), and evaluate the validity and efficacy of the former regimen as new treatment method of intermediate to high-risk myelodysplastic syndromes. A total of 12 patients with intermediate (IR) to high-risk (HR) MDS treated by low-dose decitabine combined with CAG regimen and 10 patients with IR to HR MDS treated by CAG regimen alone were evaluated after treatment of 1 cycle and at least after 2 cycles. The complete remission (CR) after 1 cycle, overall remission rate (ORR), progression free survival (PFS) and overall survival (OS) between them were analyzed. The results showed that 9 patients treated by low-dose decitabine combined with CAG regimen achieved complete remission after 1 cycle, 2 patients achieved partial remission, 1 patient did not show reaction. The complete remission rate was 75.0% and overall response rate was 91.7%. The median time of disease free survival was 9 months (0-27 months). The median overall survival time was 16 months (3-28 months). 4 patients suffered from pulmonary infection after treatment and then were all cured after treatment with anti-infective therapy. The 5 patients treated by CAG regimen alone achieved complete remission,3 patients achieved partial remission, 2 patients showed non-reaction. The complete remission rate was 50.0% and overall response rate was 80.0%. The median time of disease free survival was 6 months(0-18 months). The median overall survival time was 13 months(3-31 months), 4 patients suffered from pulmonary infection, 1 patient suffered from enteric infection and 1 patient suffered from Escherichia coli septicemia after treatment, all of them becomed better after active treatment. Two groups of patients all had no serious adverse reactions, All patients could tolerate, no

  17. Mismatch repair genes Mlh1 and Mlh3 modify CAG instability in Huntington's disease mice: genome-wide and candidate approaches.

    Directory of Open Access Journals (Sweden)

    Ricardo Mouro Pinto

    2013-10-01

    Full Text Available The Huntington's disease gene (HTT CAG repeat mutation undergoes somatic expansion that correlates with pathogenesis. Modifiers of somatic expansion may therefore provide routes for therapies targeting the underlying mutation, an approach that is likely applicable to other trinucleotide repeat diseases. Huntington's disease Hdh(Q111 mice exhibit higher levels of somatic HTT CAG expansion on a C57BL/6 genetic background (B6.Hdh(Q111 than on a 129 background (129.Hdh(Q111 . Linkage mapping in (B6x129.Hdh(Q111 F2 intercross animals identified a single quantitative trait locus underlying the strain-specific difference in expansion in the striatum, implicating mismatch repair (MMR gene Mlh1 as the most likely candidate modifier. Crossing B6.Hdh(Q111 mice onto an Mlh1 null background demonstrated that Mlh1 is essential for somatic CAG expansions and that it is an enhancer of nuclear huntingtin accumulation in striatal neurons. Hdh(Q111 somatic expansion was also abolished in mice deficient in the Mlh3 gene, implicating MutLγ (MLH1-MLH3 complex as a key driver of somatic expansion. Strikingly, Mlh1 and Mlh3 genes encoding MMR effector proteins were as critical to somatic expansion as Msh2 and Msh3 genes encoding DNA mismatch recognition complex MutSβ (MSH2-MSH3. The Mlh1 locus is highly polymorphic between B6 and 129 strains. While we were unable to detect any difference in base-base mismatch or short slipped-repeat repair activity between B6 and 129 MLH1 variants, repair efficiency was MLH1 dose-dependent. MLH1 mRNA and protein levels were significantly decreased in 129 mice compared to B6 mice, consistent with a dose-sensitive MLH1-dependent DNA repair mechanism underlying the somatic expansion difference between these strains. Together, these data identify Mlh1 and Mlh3 as novel critical genetic modifiers of HTT CAG instability, point to Mlh1 genetic variation as the likely source of the instability difference in B6 and 129 strains and suggest

  18. Mismatch repair genes Mlh1 and Mlh3 modify CAG instability in Huntington's disease mice: genome-wide and candidate approaches.

    Science.gov (United States)

    Pinto, Ricardo Mouro; Dragileva, Ella; Kirby, Andrew; Lloret, Alejandro; Lopez, Edith; St Claire, Jason; Panigrahi, Gagan B; Hou, Caixia; Holloway, Kim; Gillis, Tammy; Guide, Jolene R; Cohen, Paula E; Li, Guo-Min; Pearson, Christopher E; Daly, Mark J; Wheeler, Vanessa C

    2013-10-01

    The Huntington's disease gene (HTT) CAG repeat mutation undergoes somatic expansion that correlates with pathogenesis. Modifiers of somatic expansion may therefore provide routes for therapies targeting the underlying mutation, an approach that is likely applicable to other trinucleotide repeat diseases. Huntington's disease Hdh(Q111) mice exhibit higher levels of somatic HTT CAG expansion on a C57BL/6 genetic background (B6.Hdh(Q111) ) than on a 129 background (129.Hdh(Q111) ). Linkage mapping in (B6x129).Hdh(Q111) F2 intercross animals identified a single quantitative trait locus underlying the strain-specific difference in expansion in the striatum, implicating mismatch repair (MMR) gene Mlh1 as the most likely candidate modifier. Crossing B6.Hdh(Q111) mice onto an Mlh1 null background demonstrated that Mlh1 is essential for somatic CAG expansions and that it is an enhancer of nuclear huntingtin accumulation in striatal neurons. Hdh(Q111) somatic expansion was also abolished in mice deficient in the Mlh3 gene, implicating MutLγ (MLH1-MLH3) complex as a key driver of somatic expansion. Strikingly, Mlh1 and Mlh3 genes encoding MMR effector proteins were as critical to somatic expansion as Msh2 and Msh3 genes encoding DNA mismatch recognition complex MutSβ (MSH2-MSH3). The Mlh1 locus is highly polymorphic between B6 and 129 strains. While we were unable to detect any difference in base-base mismatch or short slipped-repeat repair activity between B6 and 129 MLH1 variants, repair efficiency was MLH1 dose-dependent. MLH1 mRNA and protein levels were significantly decreased in 129 mice compared to B6 mice, consistent with a dose-sensitive MLH1-dependent DNA repair mechanism underlying the somatic expansion difference between these strains. Together, these data identify Mlh1 and Mlh3 as novel critical genetic modifiers of HTT CAG instability, point to Mlh1 genetic variation as the likely source of the instability difference in B6 and 129 strains and suggest that MLH1

  19. Sex-specific mediation effect of the right fusiform face area volume on the association between variants in repeat length of AVPR1A RS3 and altruistic behavior in healthy adults.

    Science.gov (United States)

    Wang, Junping; Qin, Wen; Liu, Feng; Liu, Bing; Zhou, Yuan; Jiang, Tianzi; Yu, Chunshui

    2016-07-01

    Microsatellite variants in the arginine vasopressin receptor 1A gene (AVPR1A) RS3 have been associated with normal social behaviors variation and autism spectrum disorders (ASDs) in a sex-specific manner. However, neural mechanisms underlying these associations remain largely unknown. We hypothesized that AVPR1A RS3 variants affect altruistic behavior by modulating the gray matter volume (GMV) of specific brain regions in a sex-specific manner. We investigated 278 young healthy adults using the Dictator Game to assess altruistic behavior. All subjects were genotyped and main effect of AVPR1A RS3 repeat polymorphisms and interaction of genotype-by-sex on the GMV were assessed in a voxel-wise manner. We observed that male subjects with relatively short repeats allocated less money to others and exhibited a significantly smaller GMV in the right fusiform face area (FFA) compared with male long homozygotes. In male subjects, the GMV of the right FFA exhibited a significant positive correlation with altruistic behavior. A mixed mediation and moderation analysis further revealed both a significant mediation effect of the GMV of the right FFA on the association between AVPR1A RS3 repeat polymorphisms and allocation sums and a significant moderation effect of sex (only in males) on the mediation effect. Post hoc analysis showed that the GMV of the right FFA was significantly smaller in male subjects carrying allele 426 than in non-426 carriers. These results suggest that the GMV of the right FFA may be a potential mediator whereby the genetic variants in AVPR1A RS3 affect altruistic behavior in healthy male subjects. Hum Brain Mapp 37:2700-2709, 2016. © 2016 Wiley Periodicals, Inc.

  20. Prevalence of Helicobacter pylori cagA genotype among dyspeptic patients in Southern Thailand

    Institute of Scientific and Technical Information of China (English)

    Sueptrakool Wisessombat; Chatruthai Meethai

    2014-01-01

    Objective: To investigate the prevalence of Helicobacter pylori (H. pylori) infection in dyspepsia patients and its relation to virulence factor cagA gene. Methods: In total, 110 gastric biopsies from dyspeptic patients were comparatively studied using rapid urease test and multiplex polymerase chain reaction (PCR). Results: Multiplex PCR detected three genes of 16S rRNA, cagA, and ureC. H. pylori was detected in 14 gastric biopsies (13%). Significantly higher numbers of female were infected. Furthermore,cag A gene was found in all H. pylori-positive specimens. In addition, the result indicated that the multiplex PCR with annealing temperature at 57 oC was able to effectively amplify specific products. Conclusions:The results confirmed high prevalence of cagA gene in H. pylori among dyspeptic patients in Southern Thailand.

  1. Helicobacter pylori Anti-CagA Antibodies: Prevalence in Symptomatic and Asymptomatic Subjects in Turkey

    Directory of Open Access Journals (Sweden)

    M Fatih Abasiyanik

    2002-01-01

    Full Text Available BACKGROUND: Several reports have shown the prevalence of anti-CagA antibodies to be associated with the development of peptic ulcer diseases, while others have indicated that there is no such association.

  2. What exists beyond cagA and vacA? Helicobacter pylori genes in gastric diseases.

    Science.gov (United States)

    da Costa, Débora Menezes; Pereira, Eliane dos Santos; Rabenhorst, Silvia Helena Barem

    2015-10-01

    Helicobacter pylori (H. pylori) infection is present in more than half the world's population and has been associated with several gastric disorders, such as gastritis, peptic ulceration, and gastric adenocarcinoma. The clinical outcome of this infection depends on host and bacterial factors where H. pylori virulence genes seem to play a relevant role. Studies of cagA and vacA genes established that they were determining factors in gastric pathogenesis. However, there are gastric cancer cases that are cagA-negative. Several other virulence genes have been searched for, but these genes remain less well known that cagA and vacA. Thus, this review aimed to establish which genes have been suggested as potentially relevant virulence factors for H. pylori-associated gastrointestinal diseases. We focused on the cag-pathogenicity island, genes with adherence and motility functions, and iceA based on the relevance shown in several studies in the literature.

  3. Diagnostic value of CagA IgG in the process to eradicate Helicobacter pylori

    Institute of Scientific and Technical Information of China (English)

    Zhi Bang Yang; Pi Long Wang; Ming Ming Gu; Li Hao Chen; Quan Chen; Lin Zhan

    2000-01-01

    AIM To investigate the diagnostic value of CagA IgG in serum.METHODS Seventy three patients with peptic ulcer infected with HP were eradicated by antibioticstherapy. At pretreatment, wk9 and wk20 after treatment, the detection of Hp in gastric muscosa bybacteriologic method were performed, and CagA and whole-cell antigen of HP igG in serum by ELISAmethod were also performed at the same time.RESULTS The IgG titres of Hp CagA and whole-cell antigen changes in accordance with the efficacy ofHp eradicated. The former with an earlier appearance and a greater number of cases decreased to normallevel in comparison with the latter.CONCLUSION CagA IgG is a better index for observing the effectiveness of the eradication of Hp.

  4. Molecular mechanisms of gastric epithelial cell adhesion and injection of CagA by Helicobacter pylori

    LENUS (Irish Health Repository)

    Backert, Steffen

    2011-11-01

    Abstract Helicobacter pylori is a highly successful pathogen uniquely adapted to colonize humans. Gastric infections with this bacterium can induce pathology ranging from chronic gastritis and peptic ulcers to gastric cancer. More virulent H. pylori isolates harbour numerous well-known adhesins (BabA\\/B, SabA, AlpA\\/B, OipA and HopZ) and the cag (cytotoxin-associated genes) pathogenicity island encoding a type IV secretion system (T4SS). The adhesins establish tight bacterial contact with host target cells and the T4SS represents a needle-like pilus device for the delivery of effector proteins into host target cells such as CagA. BabA and SabA bind to blood group antigen and sialylated proteins respectively, and a series of T4SS components including CagI, CagL, CagY and CagA have been shown to target the integrin β1 receptor followed by injection of CagA across the host cell membrane. The interaction of CagA with membrane-anchored phosphatidylserine may also play a role in the delivery process. While substantial progress has been made in our current understanding of many of the above factors, the host cell receptors for OipA, HopZ and AlpA\\/B during infection are still unknown. Here we review the recent progress in characterizing the interactions of the various adhesins and structural T4SS proteins with host cell factors. The contribution of these interactions to H. pylori colonization and pathogenesis is discussed.

  5. Risk assessment of gastric cancer caused by Helicobacter pylori using CagA sequence markers.

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    Chao Zhang

    Full Text Available BACKGROUND: As a marker of Helicobacter pylori, Cytotoxin-associated gene A (cagA has been revealed to be the major virulence factor causing gastroduodenal diseases. However, the molecular mechanisms that underlie the development of different gastroduodenal diseases caused by cagA-positive H. pylori infection remain unknown. Current studies are limited to the evaluation of the correlation between diseases and the number of Glu-Pro-Ile-Tyr-Ala (EPIYA motifs in the CagA strain. To further understand the relationship between CagA sequence and its virulence to gastric cancer, we proposed a systematic entropy-based approach to identify the cancer-related residues in the intervening regions of CagA and employed a supervised machine learning method for cancer and non-cancer cases classification. METHODOLOGY: An entropy-based calculation was used to detect key residues of CagA intervening sequences as the gastric cancer biomarker. For each residue, both combinatorial entropy and background entropy were calculated, and the entropy difference was used as the criterion for feature residue selection. The feature values were then fed into Support Vector Machines (SVM with the Radial Basis Function (RBF kernel, and two parameters were tuned to obtain the optimal F value by using grid search. Two other popular sequence classification methods, the BLAST and HMMER, were also applied to the same data for comparison. CONCLUSION: Our method achieved 76% and 71% classification accuracy for Western and East Asian subtypes, respectively, which performed significantly better than BLAST and HMMER. This research indicates that small variations of amino acids in those important residues might lead to the virulence variance of CagA strains resulting in different gastroduodenal diseases. This study provides not only a useful tool to predict the correlation between the novel CagA strain and diseases, but also a general new framework for detecting biological sequence

  6. Molecular mechanisms of gastric epithelial cell adhesion and injection of CagA by Helicobacter pylori

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    Backert Steffen

    2011-11-01

    Full Text Available Abstract Helicobacter pylori is a highly successful pathogen uniquely adapted to colonize humans. Gastric infections with this bacterium can induce pathology ranging from chronic gastritis and peptic ulcers to gastric cancer. More virulent H. pylori isolates harbour numerous well-known adhesins (BabA/B, SabA, AlpA/B, OipA and HopZ and the cag (cytotoxin-associated genes pathogenicity island encoding a type IV secretion system (T4SS. The adhesins establish tight bacterial contact with host target cells and the T4SS represents a needle-like pilus device for the delivery of effector proteins into host target cells such as CagA. BabA and SabA bind to blood group antigen and sialylated proteins respectively, and a series of T4SS components including CagI, CagL, CagY and CagA have been shown to target the integrin β1 receptor followed by injection of CagA across the host cell membrane. The interaction of CagA with membrane-anchored phosphatidylserine may also play a role in the delivery process. While substantial progress has been made in our current understanding of many of the above factors, the host cell receptors for OipA, HopZ and AlpA/B during infection are still unknown. Here we review the recent progress in characterizing the interactions of the various adhesins and structural T4SS proteins with host cell factors. The contribution of these interactions to H. pylori colonization and pathogenesis is discussed.

  7. Pathogenicty and immune prophylaxis of cag pathogenicity island gene knockout homogenic mutants

    Institute of Scientific and Technical Information of China (English)

    Huan-Jian Lin; Jing Xue; Yang Bai; Ji-De Wang; Ya-Li Zhang; Dian-Yuan Zhou

    2004-01-01

    AIM: To clarify the role of cag pathogenicity island (cagPAI)of Helicobacter pylori(H pylori) in the pathogenicity and immune prophylaxis of H pyloriinfection.METHODS: Three pairs of H pylori including 3 strains of cagPAI positive wildtype bacteria and their cagPAI knockout homogenic mutants were utilized. H pylori binding to the gastric epithelial cells was analyzed by flow cytometry assays.Apoptosis of gastric epithelial cells induced by H pylori was determined by ELISA assay. Prophylaxis effect of the wildtype and mutant strains was compared by immunization with the sonicate of the bacteria into mice model.RESULTS: No difference was found in the apoptasis between cagPAI positive and knockout H pylori strains in respective of the ability in the binding to gastric epithelial cells as well as the induction of apoptosis. Both types of the bacteria were able to protect the mice from the infection of H pylori after immunization, with no difference between them regarding to the protection rate as well as the stimulation of the proliferation of splenocytes of the mice.CONCLUSION: The role of cagPAI in the pathogenicity and prophylaxis of H pylori infection remains to be cleared.

  8. Fragmentation of CagA Reduces Hummingbird Phenotype Induction by Helicobactor pylori.

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    Chih-Chi Chang

    Full Text Available Infection with Helicobacter pylori (H. pylori has been linked to various gastro-intestinal diseases; nevertheless it remains to be clarified why only a minority of infected individuals develop illness. Studies from the West have indicated that the cagA gene and the associated EPIYA genotype of H. pylori is closely linked to the development of severe gastritis and gastric carcinoma; however, as yet no consistent correlation has been found among the bacteria from East Asia. In addition to genotype variation, the CagA protein undergoes fragmentation; however, the functional significance of fragmentation with respect to H. pylori infection remains unknown. In this study, we isolated 594 H. pylori colonies from 99 patients and examined the fragmentation patterns of CagA protein using immunoblotting. By analyzing the ability of the isolates to induce the host cell morphological transition to the highly invasive hummingbird phenotype, we demonstrated that H. pylori colonies with substantial CagA fragmentation are less potent in terms of causing this morphological transition. Our results uncovered a functional role for CagA fragmentation with respect to H. pylori-induced hummingbird phenotype formation and these findings suggest the possibility that the post-translational processing of CagA may be involved in H. pylori infection pathogenesis.

  9. Deletion of cagA gene of Helicobacter pylori by PCR products

    Institute of Scientific and Technical Information of China (English)

    Xun Zeng; Li-Hua He; Yan Yin; Mao-Jun Zhang; Jian-Zhong Zhang

    2005-01-01

    AIM: Cytotoxin-associated protein (antigen) A (CagA)plays an important role in Helicobacter pylori(H pylori)pathogenesis. Our aim was to obtain cagA mutant strains by a new mutation method so as to better understand the mechanism of CagA in epithelial cells. METHODS: In contrast with the traditional method using suicide plasmid, we constructed cagA- mutant strains directly with PCR products. The constructed mutant clones grew on selective media and allelic exchange was confirmed by Southern blot. Furthermore, two different transformation methods, electroporation, and natural transformation, were compared with regard to the efficiency of recombination.RESULTS: The mutation by PCR products could be completed within 3-5 d, and the recombination rate by electroporation and natural transformation was 4.02×10-8 and 1.03x 10-9 respectively. Mutation rate by electroporation (4.02× 10-8) was far higher than by natural transformation (1.03× 10-9) (P = 0.000<0.005).CONCLUSION: cagA- mutant strains have been constructed,which is important for further study on the function of CagA in epithelial cells. A mutation method by directly using PCR products has been proved successful with a much higher mutation rate, and is easier, especially when in combination with electroporation. This method could be widely used in gene deletion of H pylori.

  10. Study on Effect of ANTI-VacA + CagA + Helicobacter pylori-IgY Against VacA + CagA + Hp%抗VacA+CagA+幽门螺杆菌IgY的抗感染作用研究

    Institute of Scientific and Technical Information of China (English)

    傅颖媛; 黎健; 李娟; 曾小平; 况南珍

    2006-01-01

    为研究抗VacA+CagA+幽门螺杆菌(Hp)IgY的抗感染作用,以VacA+CagA+Hp为抗原免疫蛋鸡,聚乙二醇法和水稀释法从鸡卵黄中提取抗-VacA+CagA+Hp-lgY,酶联免疫吸附实验(ELISA)测定IgY抗体效价.建立胃腔感染VacA+CagA Hp的昆明系小鼠模型,观察抗-VacA+CagA+Hp-IgY对小鼠胃腔感染VacA+CagA+Hp的防治效果.ELISA法测定IgY效价均为1:20,480;抗-VacA+CagA+Hp-IgY防治小鼠胃腔感染VacA+CagA Hp效果较理想,IgY高、中剂量组效果优于阳性对照组(P<0.05);低剂量组效果等同于阳性对照组(P>0.05).抗-VacA+CagA+Hp-IgY较好的体内抗感染作用,提示该IgY有望成为较理想的治疗VacA+CagA+Hp感染的生物制剂.

  11. Polyglutamine length-dependent toxicity from α1ACT in Drosophila models of spinocerebellar ataxia type 6

    Science.gov (United States)

    Tsou, Wei-Ling; Qiblawi, Sultan H.; Hosking, Ryan R.; Gomez, Christopher M.

    2016-01-01

    ABSTRACT Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disease that results from abnormal expansion of a polyglutamine (polyQ) repeat. SCA6 is caused by CAG triplet repeat expansion in the gene CACNA1A, resulting in a polyQ tract of 19-33 in patients. CACNA1A, a bicistronic gene, encodes the α1A calcium channel subunit and the transcription factor, α1ACT. PolyQ expansion in α1ACT causes degeneration in mice. We recently described the first Drosophila models of SCA6 that express α1ACT with a normal (11Q) or hyper-expanded (70Q) polyQ. Here, we report additional α1ACT transgenic flies, which express full-length α1ACT with a 33Q repeat. We show that α1ACT33Q is toxic in Drosophila, but less so than the 70Q version. When expressed everywhere, α1ACT33Q-expressing adults die earlier than flies expressing the normal allele. α1ACT33Q causes retinal degeneration and leads to aggregated species in an age-dependent manner, but at a slower pace than the 70Q counterpart. According to western blots, α1ACT33Q localizes less readily in the nucleus than α1ACT70Q, providing clues into the importance of polyQ tract length on α1ACT localization and its site of toxicity. We expect that these new lines will be highly valuable for future work on SCA6. PMID:27979829

  12. Androgen receptor gene polymorphisms lean mass and performance in young men.

    Science.gov (United States)

    Guadalupe-Grau, Amelia; Rodríguez-González, F Germán; Dorado, Cecilia; Olmedillas, Hugo; Fuentes, Teresa; Pérez-Gómez, Jorge; Delgado-Guerra, Safira; Vicente-Rodríguez, Germán; Ara, Ignacio; Guerra, Borja; Arteaga-Ortiz, Rafael; Calbet, José A L; Díaz-Chico, B Nicolás

    2011-02-01

    The exon-1 of the androgen receptor (AR) gene contains two repeat length polymorphisms which modify either the amount of AR protein inside the cell (GGN(n), polyglycine) or its transcriptional activity (CAG(n), polyglutamine). Shorter CAG and/or GGN repeats provide stronger androgen signalling and vice versa. To test the hypothesis that CAG and GGN repeat AR polymorphisms affect muscle mass and various variables of muscular strength phenotype traits, the length of CAG and GGN repeats was determined by PCR and fragment analysis and confirmed by DNA sequencing of selected samples in 282 men (28.6 ± 7.6 years). Individuals were grouped as CAG short (CAG(S)) if harbouring repeat lengths of ≤ 21 and CAG long (CAG(L)) if CAG >21. GGN was considered short (GGN(S)) or long (GGN(L)) if GGN ≤ 23 or >23, respectively. No significant differences in lean body mass or fitness were observed between the CAG(S) and CAG(L) groups, or between GGN(S) and GGN(L) groups, but a trend for a correlation was found for the GGN repeat and lean mass of the extremities (r=-0.11, p=0.06). In summary, the lengths of CAG and GGN repeat of the AR gene do not appear to influence lean mass or fitness in young men.

  13. A study on the trinucleotide repeat associated with Huntington`s disease in the Chinese

    Energy Technology Data Exchange (ETDEWEB)

    Bing-wen Soong; Jih-tsuu Wang [Neurological Institute, Taipei (Taiwan, Province of China)

    1994-09-01

    Analysis of the polymorphic (CAG)n repeat in the hungingtin gene in the chinese confirmed the presence of an expanded repeat on all Huntington`s disease chromosomes. Measurement of the specific CAG repeat sequence in 34 HD chromosomes from 15 unrelated families and 190 control chromosomes from the Chinese population showed a range from 9 to 29 repeats in normal subjects and 40 to 58 in affected subjects. The size distributions of normal and affected alleles did not overlap. A clear correlation bewteen early onset of symptoms and very high repeat number was seen, but the spread of the age-at-onset in the major repeat range producing characteristic HD it too wide to be of diagnostic value. There was also variability in the transmitted repeat size for both sexes in the HD size range. Maternal HD alleles showed a moderate instability with a preponderance of size decrease, while paternal HD alleles had a tendency to increase in repeat size on transmission, the degree of which appeared proportional to the initial size.

  14. Association of Helicobacter pylori cagA Gene with Gastric Cancer and Peptic Ulcer in Saudi Patients.

    Science.gov (United States)

    Saber, Taisir; Ghonaim, Mabrouk M; Yousef, Amany R; Khalifa, Amany; Al Qurashi, Hesham; Shaqhan, Mohammad; Samaha, Mohammad

    2015-07-01

    This study was conducted to assess the relationship between occurrence of gastric cancer and peptic ulcer, and the presence of H. pylori cagA gene and anti-CagA IgG, and to estimate the value of these antibodies in detecting infection by cagA gene-positive H. pylori strains in Saudi patients. The study included 180 patients who were subjected to upper gastrointestinal endoscopy in Taif province and Western region of Saudi Arabia (60 gastric cancer, 60 peptic ulcer, and 60 with non-ulcer dyspepsia). Gastric biopsy specimens were obtained and tested for H. pylori infection by rapid urease test and culture. PCR was performed on the isolated strains and biopsy specimens for detection of the cagA gene. Blood samples were collected and tested for CagA IgG by ELISA. H. pylori infection was detected among 72.8% of patients. The cagA gene and anti-CagA IgG were found in 63.4% and 61.8% of H. pylori-infected patients, respectively. They were significantly (p ulcer compared with those with non-ulcer dyspepsia. Detection of the CagA IgG was 91.6% sensitive, 89.6% specific, and 90.8% accurate compared with detection of the cagA gene. Its positive and negative predictive values were 93.8% and 86%, respectively. The study showed a significant association between the presence of the cagA gene and gastric cancer and peptic ulcer disease, and between anti-CagA IgG and the cagA gene in Saudi patients. However, a further larger study is required to confirm this finding.

  15. Intergeneration CAG expansion in a Wuhan juvenile-onset Huntingto ndisease family%武汉地区CAG扩增突变致青少年发病的亨廷顿舞蹈病的家系分析

    Institute of Scientific and Technical Information of China (English)

    刘媛; 沈滟; 李和; 王慧; 杨真荣; 陈燕; 唐艳平

    2007-01-01

    目的 对青少年发病的亨廷顿舞蹈病(Huntington disease)家系进行致病IT15基因早期诊断分析,为家系成员提供遗传咨询,并为后续的HD发病机制及实验治疗研究提供依据.方法 按照知情同意原则抽取家系成员外周血,提取基因组DNA,采用改良的降落PCR方法扩增IT15基因致病区域,DNA测序检测异常等位基因(CAG)n三核苷酸重复次数.结果 在该家系三代25名成员中,共发现8名致病IT15基因携带者,其中,Ⅲ10、Ⅲ12、Ⅲ14、Ⅳ3和Ⅴ2 CAG三核苷酸的拷贝数均为48,Ⅳ11和Ⅳ12均为(CAG)67,Ⅳ14为(CAG)63,而对照组35名正常人的CAG三核苷酸的拷贝数为8-25,两者之间没有重叠.结论 家系中第四代致病基因携带者Ⅳ14与第三代患者Ⅲ10比较,CAG三核苷酸重复次数增加15次,即本家系IT15基因在传递过程中发生了扩增突变.同时,扩增突变导致该家系出现青少年发病及遗传早现现象.%Objective To make early diagnosis of IT15 gene mutation in a Wuhan juvenile-onset Huntington disease (HD)family, for providing them with genetic counseling, and making preparation for the further research on pathogenesis and experimental therapy of HD. Methods According to the principle of informed consent, we extracted genomic DNA from peripheral blood samples and carried genetic diagnosis of pathogenic exon 1 of IT15 gene by modified touchdown PCR and DNA sequencing methods. Results Eight of twenty-five family members carried abnormal allele: Ⅲ10, Ⅲ12, Ⅲ14, Ⅳ3,and Ⅴ2 carried (CAG) 48, Ⅳ11 and Ⅳ12 carried (CAG) 67, and Ⅳ14 carried (CAG) 63, in contrast with the 8-25 CAG trinucleotides in the members of control group. Ⅳ14 carried 15 more CAG trinucleotides than her father Ⅲ10. Conclusion The results definitely confirm the diagnosis of HD and indicate the CAG trinucleotide repeat expansion of IT15 gene in this HD family.In addition, CAG expansion results in juvenile-onset and anticipation (characterized

  16. Helicobacter pylori cagA and vacA genotypes in Cuban and Venezuelan populations

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    Diana Ortiz-Princz

    2010-05-01

    Full Text Available The aim of this study was to determine the presence of Helicobacter pylori cytotoxin-associated gene (cagA/vacuolating cytotoxin gene (vacA among patients with chronic gastritis in Cuba and Venezuela. Gastric antrum biopsies were taken for culture, DNA extraction and PCR analysis. Amplification of vacA and cagA segments was performed using two regions of cagA: 349 bp were amplified with the F1/B1 primers and the remaining 335 bp were amplified with the B7629/B7628 primers. The VA1-F/VA1-R set of primers was used to amplify the 259-bp (s1 or 286-bp (s2 product and the VAG-R/VAG-F set of primers was used to amplify the 567-bp (m1 or 642-bp (m2 regions of vacA. cagA was detected in 87% of the antral samples from Cuban patients and 80.3% of those from Venezuelan patients. All possible combinations of vacA regions were found, with the exception of s2/m1. The predominant combination found in both countries was s1/m1. The percentage of cagA+ strains was increased by the use of a second set of primers and a greater number of strains was amplified with the B7629/B7628 primers in the Cuban patients (p = 0.0001. There was no significant difference between the presence of the allelic variants of vacA and cagA in both populations. The predominant genotype was cagA+/s1m1 in both countries. The results support the necessary investigation of isolates circulating among the human population in each region.

  17. Histone deacetylase complexes promote trinucleotide repeat expansions.

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    Kim Debacker

    2012-02-01

    Full Text Available Expansions of DNA trinucleotide repeats cause at least 17 inherited neurodegenerative diseases, such as Huntington's disease. Expansions can occur at frequencies approaching 100% in affected families and in transgenic mice, suggesting that specific cellular proteins actively promote (favor expansions. The inference is that expansions arise due to the presence of these promoting proteins, not their absence, and that interfering with these proteins can suppress expansions. The goal of this study was to identify novel factors that promote expansions. We discovered that specific histone deacetylase complexes (HDACs promote CTG•CAG repeat expansions in budding yeast and human cells. Mutation or inhibition of yeast Rpd3L or Hda1 suppressed up to 90% of expansions. In cultured human astrocytes, expansions were suppressed by 75% upon inhibition or knockdown of HDAC3, whereas siRNA against the histone acetyltransferases CBP/p300 stimulated expansions. Genetic and molecular analysis both indicated that HDACs act at a distance from the triplet repeat to promote expansions. Expansion assays with nuclease mutants indicated that Sae2 is one of the relevant factors regulated by Rpd3L and Hda1. The causal relationship between HDACs and expansions indicates that HDACs can promote mutagenesis at some DNA sequences. This relationship further implies that HDAC3 inhibitors being tested for relief of expansion-associated gene silencing may also suppress somatic expansions that contribute to disease progression.

  18. ATXN2-CAG42 sequesters PABPC1 into insolubility and induces FBXW8 in cerebellum of old ataxic knock-in mice.

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    Ewa Damrath

    Full Text Available Spinocerebellar Ataxia Type 2 (SCA2 is caused by expansion of a polyglutamine encoding triplet repeat in the human ATXN2 gene beyond (CAG(31. This is thought to mediate toxic gain-of-function by protein aggregation and to affect RNA processing, resulting in degenerative processes affecting preferentially cerebellar neurons. As a faithful animal model, we generated a knock-in mouse replacing the single CAG of murine Atxn2 with CAG42, a frequent patient genotype. This expansion size was inherited stably. The mice showed phenotypes with reduced weight and later motor incoordination. Although brain Atxn2 mRNA became elevated, soluble ATXN2 protein levels diminished over time, which might explain partial loss-of-function effects. Deficits in soluble ATXN2 protein correlated with the appearance of insoluble ATXN2, a progressive feature in cerebellum possibly reflecting toxic gains-of-function. Since in vitro ATXN2 overexpression was known to reduce levels of its protein interactor PABPC1, we studied expansion effects on PABPC1. In cortex, PABPC1 transcript and soluble and insoluble protein levels were increased. In the more vulnerable cerebellum, the progressive insolubility of PABPC1 was accompanied by decreased soluble protein levels, with PABPC1 mRNA showing no compensatory increase. The sequestration of PABPC1 into insolubility by ATXN2 function gains was validated in human cell culture. To understand consequences on mRNA processing, transcriptome profiles at medium and old age in three different tissues were studied and demonstrated a selective induction of Fbxw8 in the old cerebellum. Fbxw8 is encoded next to the Atxn2 locus and was shown in vitro to decrease the level of expanded insoluble ATXN2 protein. In conclusion, our data support the concept that expanded ATXN2 undergoes progressive insolubility and affects PABPC1 by a toxic gain-of-function mechanism with tissue-specific effects, which may be partially alleviated by the induction of FBXW

  19. ABO blood groups and Helicobacter pylori cagA infection: evidence of an association

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    DE Mattos

    2010-01-01

    Full Text Available Diseases resulting from Helicobacter pylori infection appear to be dependent on a host of genetic traits and virulence factors possessed by this microorganism. This paper aimed to investigate the association between the ABO histo-blood groups and H. pylori cagA infections. Genomic DNA samples (n = 110 of gastric biopsies obtained from patients with endoscopic diagnosis of peptic ulcers (n = 25 and chronic active gastritis (n = 85 were analyzed by PCR using specific primers for the cagA gene. Of the samples, 66.4% (n = 73 tested positive and 33.6% (n = 37 negative for the gene. The cagA strain was predominant in peptic ulcers (n = 21; 84.0% compared with chronic active gastritis (n = 52; 61.2% (p = 0.05; OR 3.332; 95% CI: 1.050-10.576. Additionally, the cagA strain was prevalent in the type O blood (48/63; 76.2% compared with other ABO phenotypes (25/47; 53.2% (p = 0.01; OR 2.816; 95% CI: 1.246-6.364. These results suggest that H. pylori cagA infection is associated with the O blood group in Brazilian patients suffering from chronic active gastritis and peptic ulcers.

  20. 幽门螺杆菌CagA蛋白研究进展

    Institute of Scientific and Technical Information of China (English)

    汪苏; 周建奖; 单可人

    2008-01-01

    幽门螺杆菌(Helicobacterpylori,Hp)分泌的许多毒力因子与胃部疾病有关,其中毒素相关基因A(cytotoxin-associatedgeneA,cagA)表达的蛋白C种得到特别关注。cag致病岛(cagpathogenicityisland,cagPAI)编码的Ⅳ型分泌系统(T4SS)将CagA运输到胃上皮细胞,一旦进入胃上皮细胞,CagA通过依赖或不依赖酪氨酸磷酸化与多种细胞蛋白作用,调控细胞生长和运动相关的信号通路,使胃上皮细胞发生转化而致癌变。最近的研究发现,整联蛋白(integrin)、c-Abl等在C甜作用于宿主细胞的过程中起到了非常重要的作用。现就CagA的研究进展综述如下。

  1. Pathogenicity island cag, vacA and IS605 genotypes in Mexican strains of Helicobacter pylori associated with peptic ulcers

    Directory of Open Access Journals (Sweden)

    Tabche-Barrera María L

    2011-05-01

    Full Text Available Abstract Background Helicobacter pylori is associated with chronic gastritis, peptic ulcers, and gastric cancer. Two major virulence factors of H. pylori have been described: the pathogenicity island cag (cag PAI and the vacuolating cytotoxin gene (vacA. Virtually all strains have a copy of vacA, but its genotype varies. The cag PAI is a region of 32 genes in which the insertion of IS605 elements in its middle region has been associated with partial or total deletions of it that have generated strains with varying virulence. Accordingly, the aim of this work was to determine the cag PAI integrity, vacA genotype and IS605 status in groups of isolates from Mexican patients with non-peptic ulcers (NPU, non-bleeding peptic ulcers (NBPU, and bleeding peptic ulcers (BPU. Methods The cag PAI integrity was performed by detection of eleven targeted genes along this locus using dot blot hybridization and PCR assays. The vacA allelic, cag PAI genotype 1 and IS605 status were determined by PCR analysis. Results Groups of 16-17 isolates (n = 50 from two patients with NPU, NBPU, and BPU, respectively, were studied. 90% (45/50 of the isolates harbored a complete cag PAI. Three BPU isolates lacked the cag PAI, and two of the NBPU had an incomplete cag PAI: the first isolate was negative for three of its genes, including deletion of the cagA gene, whereas the second did not have the cagM gene. Most of the strains (76% had the vacA s1b/m1 genotype; meanwhile the IS605 was not present within the cag PAI of any strain but was detected elsewhere in the genome of 8% (4/50. Conclusion The patients had highly virulent strains since the most of them possessed a complete cag PAI and had a vacA s1b/m1 genotype. All the isolates presented the cag PAI without any IS605 insertion (genotype 1. Combined vacA genotypes showed that 1 NPU, 2 NBPU, and 1 BPU patients (66.6% had a mixed infection; coexistence of H. pylori strains with different cag PAI status was observed in 1 NBPU

  2. Molecular chaperones enhance the degradation of expanded polyglutamine repeat androgen receptor in a cellular model of spinal and bulbar muscular atrophy

    NARCIS (Netherlands)

    Bailey, CK; Andriola, IFM; Kampinga, HH; Merry, DE

    2002-01-01

    Spinal and bulbar muscular atrophy (SBMA) is one of a growing number of neurodegenerative diseases caused by a polyglutamine-encoding CAG trinucleotide repeat expansion, and is caused by an expansion within exon 1 of the androgen receptor (AR) gene. The family of polyglutamine diseases is characteri

  3. A broad phenotypic screen identifies novel phenotypes driven by a single mutant allele in Huntington's disease CAG knock-in mice.

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    Sabine M Hölter

    Full Text Available Huntington's disease (HD is an autosomal dominant neurodegenerative disorder caused by the expansion of a CAG trinucleotide repeat in the HTT gene encoding huntingtin. The disease has an insidious course, typically progressing over 10-15 years until death. Currently there is no effective disease-modifying therapy. To better understand the HD pathogenic process we have developed genetic HTT CAG knock-in mouse models that accurately recapitulate the HD mutation in man. Here, we describe results of a broad, standardized phenotypic screen in 10-46 week old heterozygous HdhQ111 knock-in mice, probing a wide range of physiological systems. The results of this screen revealed a number of behavioral abnormalities in HdhQ111/+ mice that include hypoactivity, decreased anxiety, motor learning and coordination deficits, and impaired olfactory discrimination. The screen also provided evidence supporting subtle cardiovascular, lung, and plasma metabolite alterations. Importantly, our results reveal that a single mutant HTT allele in the mouse is sufficient to elicit multiple phenotypic abnormalities, consistent with a dominant disease process in patients. These data provide a starting point for further investigation of several organ systems in HD, for the dissection of underlying pathogenic mechanisms and for the identification of reliable phenotypic endpoints for therapeutic testing.

  4. A broad phenotypic screen identifies novel phenotypes driven by a single mutant allele in Huntington's disease CAG knock-in mice.

    Science.gov (United States)

    Hölter, Sabine M; Stromberg, Mary; Kovalenko, Marina; Garrett, Lillian; Glasl, Lisa; Lopez, Edith; Guide, Jolene; Götz, Alexander; Hans, Wolfgang; Becker, Lore; Rathkolb, Birgit; Rozman, Jan; Schrewed, Anja; Klingenspor, Martin; Klopstock, Thomas; Schulz, Holger; Wolf, Eckhard; Wursta, Wolfgang; Gillis, Tammy; Wakimoto, Hiroko; Seidman, Jonathan; MacDonald, Marcy E; Cotman, Susan; Gailus-Durner, Valérie; Fuchs, Helmut; de Angelis, Martin Hrabě; Lee, Jong-Min; Wheeler, Vanessa C

    2013-01-01

    Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by the expansion of a CAG trinucleotide repeat in the HTT gene encoding huntingtin. The disease has an insidious course, typically progressing over 10-15 years until death. Currently there is no effective disease-modifying therapy. To better understand the HD pathogenic process we have developed genetic HTT CAG knock-in mouse models that accurately recapitulate the HD mutation in man. Here, we describe results of a broad, standardized phenotypic screen in 10-46 week old heterozygous HdhQ111 knock-in mice, probing a wide range of physiological systems. The results of this screen revealed a number of behavioral abnormalities in HdhQ111/+ mice that include hypoactivity, decreased anxiety, motor learning and coordination deficits, and impaired olfactory discrimination. The screen also provided evidence supporting subtle cardiovascular, lung, and plasma metabolite alterations. Importantly, our results reveal that a single mutant HTT allele in the mouse is sufficient to elicit multiple phenotypic abnormalities, consistent with a dominant disease process in patients. These data provide a starting point for further investigation of several organ systems in HD, for the dissection of underlying pathogenic mechanisms and for the identification of reliable phenotypic endpoints for therapeutic testing.

  5. {sup 18}F-FDG PET uptake in the pre-Huntington disease caudate affects the time-to-onset independently of CAG expansion size

    Energy Technology Data Exchange (ETDEWEB)

    Ciarmiello, Andrea; Giovacchini, Giampiero; Bruselli, Laura [Nuclear Medicine Department, S. Andrea Hospital, La Spezia (Italy); Orobello, Sara; Elifani, Francesca; Squitieri, Ferdinando [Centre for Neurogenetics and Rare Diseases, IRCCS Neuromed, Pozzilli, IS (Italy)

    2012-06-15

    To test in a longitudinal follow-up study whether basal glucose metabolism in subjects with a genetic risk of Huntington disease (HD) may influence the onset of manifest symptoms. The study group comprised 43 presymptomatic (preHD) subjects carrying the HD mutation. They underwent a {sup 18}F-FDG PET scan and were prospectively followed-up for at least 5 years using the unified HD rating scale to detect clinical changes. Multiple regression analysis included subject's age, CAG mutation size and glucose uptake as variables in a model to predict age at onset. Of the 43 preHD subjects who manifested motor symptoms, suggestive of HD, after 5 years from the PET scan, 26 showed a mean brain glucose uptake below the cut-off of 1.0493 in the caudate, significantly lower than the 17 preHD subjects who remained symptom-free (P < 0.0001). This difference was independent of mutation size. Measurement of brain glucose uptake improved the CAG repeat number and age-based model for predicting age at onset by 37 %. A reduced level of glucose metabolism in the brain caudate may represent a predisposing factor that contributes to the age at onset of HD in preHD subjects, in addition to the mutation size. (orig.)

  6. 幽门螺杆菌VacA和CagA的研究进展

    Institute of Scientific and Technical Information of China (English)

    龙敏; 别平华; 俞守义; 凌贤龙; 房殿春

    2001-01-01

    幽门螺杆菌(Hp)感染呈全球性分布,多数地区感染达50%,细胞空泡毒素(VacA)及细胞毒相关蛋白(CagA)在Hp致病过程中起重要作用.不同Hp菌株的VacA和CagA存在基因型和表型的差异.研究Hp的vacA和cagA基因及其产物对于进一步阐明与临床的关系、Hp感染疾病的防治都有十分重要的意义.

  7. Characterization of the Cag pathogenicity island in Helicobacter pylori from naturally infected rhesus macaques.

    Science.gov (United States)

    Skoog, Emma C; Deck, Samuel L; Entwistle, Hasan D; Hansen, Lori M; Solnick, Jay V

    2016-12-01

    Helicobacter pylori commonly infects the epithelial layer of the human stomach and in some individuals causes peptic ulcers, gastric adenocarcinoma or gastric lymphoma. Helicobacter pylori is a genetically diverse species, and the most important bacterial virulence factor that increases the risk of developing disease, versus asymptomatic colonization, is the cytotoxin associated gene pathogenicity island (cagPAI). Socially housed rhesus macaques are often naturally infected with H. pylori similar to that which colonizes humans, but little is known about the cagPAI. Here we show that H. pylori strains isolated from naturally infected rhesus macaques have a cagPAI very similar to that found in human clinical isolates, and like human isolates, it encodes a functional type IV secretion system. These results provide further support for the relevance of rhesus macaques as a valid experimental model for H. pylori infection in humans.

  8. Helicobacter pylori cag-Pathogenicity island-dependent early immunological response triggers later precancerous gastric changes in Mongolian gerbils.

    Directory of Open Access Journals (Sweden)

    Tobias Wiedemann

    Full Text Available Infection with Helicobacter pylori, carrying a functional cag type IV secretion system (cag-T4SS to inject the Cytotoxin associated antigen (CagA into gastric cells, is associated with an increased risk for severe gastric diseases in humans. Here we studied the pathomechanism of H. pylori and the role of the cag-pathogenicity island (cag-PAI for the induction of gastric ulcer and precancerous conditions over time (2-64 weeks using the Mongolian gerbil model. Animals were challenged with H. pylori B128 (WT, or an isogenic B128DeltacagY mutant-strain that produces CagA, but is unable to translocate it into gastric cells. H. pylori colonization density was quantified in antrum and corpus mucosa separately. Paraffin sections were graded for inflammation and histological changes verified by immunohistochemistry. Physiological and inflammatory markers were quantitated by RIA and RT-PCR, respectively. An early cag-T4SS-dependent inflammation of the corpus mucosa (4-8 weeks occurred only in WT-infected animals, resulting in a severe active and chronic gastritis with a significant increase of proinflammatory cytokines, mucous gland metaplasia, and atrophy of the parietal cells. At late time points only WT-infected animals developed hypochlorhydria and hypergastrinemia in parallel to gastric ulcers, gastritis cystica profunda, and focal dysplasia. The early cag-PAI-dependent immunological response triggers later physiological and histopathological alterations towards gastric malignancies.

  9. Helicobacter pylori and cagA gene detected by polymerase chain reaction in gastric biopsies: correlation with histological findings, proliferation and apoptosis

    OpenAIRE

    Katia Ramos Moreira Leite; Elaine Darini; Flavio Canelas Canavez; Claudia Muraro de Carvalho; Cristina Aparecida Troquez da Silveira Mitteldorf; Luiz Heraldo Camara-Lopes

    2005-01-01

    CONTEXT AND OBJECTIVE: The virulence of Helicobacter pylori (HP) in gastroduodenal disease is related to pathogenicity islands (cagPAI) present in some strains. Infection with cagPAI induces IL-8 secretion, increases epithelial cell proliferation and may be important in carcinogenesis. Our objective was to detect HP and the cagA gene (cagPAI marker) by polymerase chain reaction (PCR) and to correlate these results to histological findings, epithelial cell proliferation and apoptosis. DESIGN A...

  10. 西安地区幽门螺杆菌cagA、cagE、vacA基因型与上消化道疾病的关系

    Institute of Scientific and Technical Information of China (English)

    庄坤; 宋瑛; 张玲霞; 张沥; 张欣; 张宁霞; 方雅丽

    2014-01-01

    目的:探讨西安地区就医人群幽门螺杆菌(HP)菌株vacA、cagA、cagE基因型与上消化道疾病的关系。方法:选取胃粘膜活检组织中分离培养到幽门螺杆菌的消化性溃疡58例,慢性胃炎30例,采用标准酚-氯仿抽提法提取 HP基因组DNA ,检测幽门螺杆菌cagA、cagE、vacA在消化性溃疡及慢性胃炎患者胃组织中的表达。结果:88株幽门螺杆菌中cag A 的阳性率为100%, cagE的阳性率为100%,vacA s1/m-的阳性率为17.0%,vacA s1/m1a的阳性率为2.3%,vacA s1/m1a+m1b的阳性率为1.1%,vacA s1/m1a+ m2的阳性率为1.1%,vacA s1/m2的阳性率为55.7%,vacA s1/m1b+m2的阳性率为1.1%,vacA s1/m1b的阳性率为17.0%,vacA s2/m2的阳性率为2.3%。结论:西安地区就医人群培养分离的 H P菌株中,cag A 和cag E阳性率均为100%,与本地区疾病类型和严重程度不相关,不能作为西安地区HP毒力强弱的标志。西安地区就医人群幽门螺杆菌菌株的vacA基因型以s1/m2为主,但vacA各基因亚型均与临床结局无相关性。

  11. Mining of simple sequence repeats in the Genome of Gentianaceae

    Directory of Open Access Journals (Sweden)

    R Sathishkumar

    2011-01-01

    Full Text Available Simple sequence repeats (SSRs or short tandem repeats are short repeat motifs that show high level of length polymorphism due to insertion or deletion mutations of one or more repeat types. Here, we present the detection and abundance of microsatellites or SSRs in nucleotide sequences of Gentianaceae family. A total of 545 SSRs were mined in 4698 nucleotide sequences downloaded from the National Center for Biotechnology Information (NCBI. Among the SSR sequences, the frequency of repeat type was about 429 -mono repeats, 99 -di repeats, 15 -tri repeats, and 2 --hexa repeats. Mononucleotide repeats were found to be abundant repeat types, about 78%, followed by dinucleotide repeats (18.16% among the SSR sequences. An attempt was made to design primer pairs for 545 identified SSRs but these were found only for 169 sequences.

  12. CAG microsatellite polymorphisms of androgen receptor gene and the stage and grade of prostate cancer%雄激素受体基因微卫星CAG多态性与前列腺癌的分期分级

    Institute of Scientific and Technical Information of China (English)

    李长岭; 吕宁; 董金堂; 关维民; 万仪增

    2001-01-01

    Objective To explore the relationship between the CAG mirosatellite in androgen receptor(AR)gene and the stage and grade of prostate cancer(PC).Methods The number of CAG repeats in exon 1 of the AR gene was measured in 37 PC tissues by PCR-SSCP analysis, and its association with stages and grades of PC determined.Results The average number of CAG repeats of AR gene differed significantly between PC in stage B (25.04±1.88) and in stage C~D (24.14±2.64)(P=0.002). The frequency of short CAG(<22) was 13.0%(3/23) in stage B and 28.6%(4/14) in stage C~D, while that of long CAG(≥22) was 87.0%(20/23) and 71.4%(10/14) (P=0.029 ), respectively. The average number of CAG repeats increased with the decrease in tumor cell differentiation. The frequency of short CAG repeats dropped with the increase in tumor cell differentiation while the opposite was true for that of long CAG repeats.Conclusion The number of CAG repeats in AR gene may be one of the factors determining the biologic characteratics PC. Short CAG repeats may signify aggressiveness of PC.%目的研究雄激素受体(AR)基因三核苷酸CAG微卫星多态性与前列腺癌(PC)分期和分级的关系,探讨其与肿瘤生物学特性的相关性。方法运用聚合酶链反应-单链构象多态性分析法(PCR-SSCP),对37例PC标本的AR基因CAG微卫星数量进行测定,并进行不同病变期别、分化级别间的比较及统计学分析。结果 AR基因CAG微卫星数量在病变B期与C~D期分别为25.04±1.88和22.14±2.64(P=0.002);其短的AR基因CAG(数量<22)的分布为:B期13.0%(3/23),C~D期28.6%(4/14);其长的AR基因CAG(数量≥22)的分布为:B期87.0%(20/23),C~D期71.4%(10/14),差异有显著性(P=0.029)。AR基因CAG微卫星数量随PC病变分化程度的增高而增加,低分化为23.64±2.56,中分化为24.29±3.45,高分化为25.6±1.67,在高分化与低分化间差异有显著性(P=0.047)。短

  13. Repeat-until-success quantum repeaters

    Science.gov (United States)

    Bruschi, David Edward; Barlow, Thomas M.; Razavi, Mohsen; Beige, Almut

    2014-09-01

    We propose a repeat-until-success protocol to improve the performance of probabilistic quantum repeaters. Conventionally, these rely on passive static linear-optics elements and photodetectors to perform Bell-state measurements (BSMs) with a maximum success rate of 50%. This is a strong impediment for entanglement swapping between distant quantum memories. Every time a BSM fails, entanglement needs to be redistributed between the corresponding memories in the repeater link. The key ingredients of our scheme are repeatable BSMs. Under ideal conditions, these turn probabilistic quantum repeaters into deterministic ones. Under realistic conditions, our protocol too might fail. However, using additional threshold detectors now allows us to improve the entanglement generation rate by almost orders of magnitude, at a nominal distance of 1000 km, compared to schemes that rely on conventional BSMs. This improvement is sufficient to make the performance of our scheme comparable to the expected performance of some deterministic quantum repeaters.

  14. CagA and VacA Helicobacter Pylori Antibodies in Gastric Cancer

    Directory of Open Access Journals (Sweden)

    Renzo Suriani

    2008-01-01

    Full Text Available BACKGROUND: Infection with different genotypes of virulent Helicobacter pylori strains (cytotoxin-associated gene A [CagA]-and/or vacuolating cytotoxin A [VacA]-positive can play a role in the development of atrophic gastritis, duodenal ulcer (DU and gastric cancer (GC.

  15. CagA(+)幽门螺杆菌感染与心血管疾病

    Institute of Scientific and Technical Information of China (English)

    罗悦晨; 李玉明; 周欣

    2010-01-01

    @@ 幽门螺旋杆菌(Helicobacter pylori,HP)不仅与多种胃部疾病有着密切的关系,在其它疾病中也发挥重要的作用.其中细胞毒素相关基因(cytotoxin associated gene,CagA)阳性的HP对心血管疾病的影响是目前研究的热点之一.CagA是HP最重要的毒力标志物,其表达水平与心血管疾病的发生、发展及疾病严重程度密切相关.CagA(+)HP感染是心血管疾病的独立危险因素之一[1].本文就CagA(+)HP的检测技术及与心血管疾病的关系研究进展做一简要综述.

  16. Clinical significance of infection with cag A and vac A positive helicobacter pylori strains

    Directory of Open Access Journals (Sweden)

    Sokić-Milutinović Aleksandra

    2004-01-01

    Full Text Available Clinical relevance of infection with different Helicobacter pylori strains was reviewed in this paper. Helicobacter pylori (H. pylori infection plays a role in pathogenesis of chronic gastritis, peptic ulcer disease, gastric adenocarcinoma and MALT lymphoma. Extragastric manifestations of H. pylori infection most probably include acne rosacea and chronic urticaria, while the importance of H. pylori infection for pathogenesis of growth retardation in children, iron deficiency anemia, coronary heart disease, stroke and idiopathic thrombocytopenic purpura remains vague. The expression of two H. pylori proteins, cytotoxin associated protein (cag A and vacuolization cytotoxin (vac A is considered to be related with pathogenicity of the bacterium. It is clear that presence of cag A+ strains is important for development of peptic ulcer; nevertheless, it is also protective against esophageal reflux disease. On the other hand, cag A+ strains are common in gastric adenocarcinoma and MALT lymphoma patients, but it seems that certain subtypes of vac A cytotoxin are more important risk factors. Infection with cag A+ strains is more common in patients with acne rosacea, stroke and coronary heart disease.

  17. Induction of CD69 expression by cagPAI-positive Helicobacter pylori infection

    Institute of Scientific and Technical Information of China (English)

    Naoki Mori; Chie Ishikawa; Masachika Senba

    2011-01-01

    AIM: To investigate and elucidate the molecular mech-anism that regulates inducible expression of CD69 by Helicobacter pylori (H. pylori ) infection.METHODS: The expression levels of CD69 in a T-cell line, Jurkat, primary human peripheral blood mononu-clear cells (PBMCs), and CD4+T cells, were assessed by immunohistochemistry, reverse transcription polymerase chain reaction, and flow cytometry. Activation of CD69 promoter was detected by reporter gene. Nuclear factor (NF)-κB activation in Jurkat cells infected with H. pylori was evaluated by electrophoretic mobility shift assay. The role of NF-κB signaling in H. pylori -induced CD69 expression was analyzed using inhibitors of NF-κB and dominant-negative mutants. The isogenic mutants with disrupted cag pathogenicity island ( cagPAI) and virD4 were used to elucidate the role of cagPAI-encoding type Ⅳ secretion system and CagA in CD69 expression.RESULTS: CD69 staining was detected in mucosal lymphocytes and macrophages in specimens of pa-tients with H. pylori -positive gastritis. Although cagPAI-positive H. pylori and an isogenic mutant of virD4 induced CD69 expression, an isogenic mutant of cag-PAI failed to induce this in Jurkat cells. H. pylori also induced CD69 expression in PBMCs and CD4+T cells. The activation of the CD69 promoter by H. pylori was mediated through NF-κB. Transfection of dominant-negative mutants of IκBs, IκB kinases, and NF-κB-inducing kinase inhibited H. pylori -induced CD69 activation. Inhibitors of NF-κB suppressed H. pylori -induced CD69 mRNA expression.CONCLUSION: The results suggest that H. pylori in-duces CD69 expression through the activation of NF-κB. cagPAI might be relevant in the induction of CD69 expression in T cells. CD69 in T cells may play a role in H. pylori -induced gastritis.

  18. A transgenic Drosophila model demonstrates that the Helicobacter pylori CagA protein functions as a eukaryotic Gab adaptor.

    Directory of Open Access Journals (Sweden)

    Crystal M Botham

    2008-05-01

    Full Text Available Infection with the human gastric pathogen Helicobacter pylori is associated with a spectrum of diseases including gastritis, peptic ulcers, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. The cytotoxin-associated gene A (CagA protein of H. pylori, which is translocated into host cells via a type IV secretion system, is a major risk factor for disease development. Experiments in gastric tissue culture cells have shown that once translocated, CagA activates the phosphatase SHP-2, which is a component of receptor tyrosine kinase (RTK pathways whose over-activation is associated with cancer formation. Based on CagA's ability to activate SHP-2, it has been proposed that CagA functions as a prokaryotic mimic of the eukaryotic Grb2-associated binder (Gab adaptor protein, which normally activates SHP-2. We have developed a transgenic Drosophila model to test this hypothesis by investigating whether CagA can function in a well-characterized Gab-dependent process: the specification of photoreceptors cells in the Drosophila eye. We demonstrate that CagA expression is sufficient to rescue photoreceptor development in the absence of the Drosophila Gab homologue, Daughter of Sevenless (DOS. Furthermore, CagA's ability to promote photoreceptor development requires the SHP-2 phosphatase Corkscrew (CSW. These results provide the first demonstration that CagA functions as a Gab protein within the tissue of an organism and provide insight into CagA's oncogenic potential. Since many translocated bacterial proteins target highly conserved eukaryotic cellular processes, such as the RTK signaling pathway, the transgenic Drosophila model should be of general use for testing the in vivo function of bacterial effector proteins and for identifying the host genes through which they function.

  19. Consensus and Variable Region PCR Analysis of Helicobacter pylori 3′ Region of cagA Gene in Isolates from Individuals with or without Peptic Ulcer

    Science.gov (United States)

    Rota, Cláudia Augustin; Pereira-Lima, Júlio C.; Blaya, Carolina; Nardi, Nance Beyer

    2001-01-01

    The clinical outcome of Helicobacter pylori infection may be associated with the cagA bacterial genotype. To investigate the cagA status of H. pylori-infected patients and the relationship between cagA and peptic ulcer disease, gastric biopsy specimens from 103 Caucasian patients in Brazil were analyzed by PCR. Since allelic variation in cagA exists and distinct H. pylori subgenotypes may circulate in different regions, PCR using primers for a variable 3′ region of the cagA gene according to a Japanese methodology and for a consensus cagA 3′ region used in Western methods was used for cagA detection. cagA was present in 53 (71%) of 75 H. pylori-positive cases when analyzed by the consensus region method and was associated with duodenal ulcer disease (P = 0.02), but not with gastric ulcer (P = 0.26), when compared to patients with duodenitis or gastritis. The variable region PCR method was able to detect 43 (57%) cagA-positive cases within the same group of H. pylori-positive patients and showed three subtypes of cagA (A, B/D, and C) that were not associated with clinical outcome. However, in 8 (18%) of the cases, more than one subtype was present, and an association between patients with multiple subtypes and disease outcome was observed when compared to patients with isolated subtypes (P = 0.048). cagA was a marker of H. pylori strains for duodenal ulcer disease in our population, and in spite of the differences in the 3′ region of the cagA gene, the Japanese methodology was able to detect the cagA status in most cases. The presence of multiple subgenotypes of cagA was associated with gastric ulcer. PMID:11158115

  20. CagA对幽门螺杆菌与宿主细胞相互作用影响的研究进展%Advance of CagA's Influences on the Interaction of Helicobacter Pylori and Host Cell

    Institute of Scientific and Technical Information of China (English)

    姬晓云; 张建中

    2007-01-01

    在体外实验中,幽门螺杆菌(Helicobacter pylori,H.pylori)和宿主细胞相互作用后发生很多变化,而H.pylori细胞毒素相关蛋白(cytotoxin associated gene A,CagA)是H.pylori重要的毒力因子之一,在H.pylori与宿主细胞相互作用中起着非常重要的作用,包括CagA转运进入细胞、CagA磷酸化和断裂,以及引起胞内信号转导通路的改变.本文就CagA对H.pylori与宿主细胞的相互作用影响进行综述.

  1. The repetitive sequence genotype research of Helicobacter pylori with VacA+ or CagA+%VacA+和CagA+的幽门螺杆菌重复序列基因分型研究

    Institute of Scientific and Technical Information of China (English)

    李晓华; 黄赞松; 黄衍强; 周喜汉; 韦鹏涯; 岑朝; 黄小凤

    2013-01-01

    Objective To investigate the correlation between Helicobacter pylori ( Hp ) with VacA + or CagA + and repetitive sequence genotype. Methods The amplification of VacA and CagA gene fragments were conducted with PCR. Strains were genotyped with REP - PCR and further clustered with NTsys_2 software. Results The 26 VacA and CagA gene positive strains were divided into six genotype groups according to homology, both with 3,3,8,4,6,2 strains in each Hp group, respectively. Conclusion The VacA and CagA positive strains could be divided into six genotype groups, and the repetitive sequence genotype is not associated with VacA and CagA gene.%目的 探索VacA+和CagA+与幽门螺杆菌(Hp)重复序列基因分型的关系.方法 采用PCR方法确定VacA+或CagA+ Hp菌株,重复序列基因分型方法分别对26株VacA+和CagA+的菌株进行基因分型,并运用NTsys_2软件,根据相似性78%进行聚类分型.结果 VacA+和CagA+的26株Hp均被分为6个基因型,分别是Group Ⅰ、Group Ⅱ、Group Ⅲ、Group Ⅳ、Group Ⅴ和Group Ⅵ,且每类聚集的菌株数相同,分别是3、3、8、4、6、2株.结论 VacA+和CagA+的Hp可以分成6大类基因型,VacA+和CagA+与Hp重复序列基因分型无密切关系.

  2. 淮南地区学生幽门螺杆菌vacA和cagA基因分布特征%Distribution Characteristics of vacA and cagA from Helicobacter Pylori Among Students in Huainan

    Institute of Scientific and Technical Information of China (English)

    汪雪峰; 崔玉宝; 王克霞; 陈琳; 吴静; 胡友莹

    2006-01-01

    目的研究淮南地区学生幽门螺杆菌(Helicobacter pylori,H.pylori)cagA和vacA基因分布特征,为防治工作提供理论依据.方法对74例有消化道症状,年龄在7~24岁的在校学生进行胃镜检查,并在胃窦部取活检粘膜作H.pylori的分离培养,利用聚合酶链反应技术(PCR)测定分离培养出的H.pylori菌株的cagA和vacA基因并进行分型.结果74例学生中,分离培养出H.pylori菌株24例,基因测定结果显示,24株H.pylori临床分离株中,94.7%(23/24)含vacA基因,70.8%(17/24)含cagA基因;其中慢性胃炎vacA和cagA基因检出率分别为94.7%(18/19),70.6%(12/17);2例胃溃疡及3例十二指肠球部溃疡均全部为vacA和cagA阳性;进一步分型发现89.5%(17/19)的慢性胃炎为vacA+和cagA+,而5例溃疡患者均为vacA+和cagA+.结论淮南地区学生H.pylori感染多为vacA+和cagA+菌株,应充分重视H.pylori毒力因子的监测.

  3. Association between gastroduodenal diseases and cagA, vacA gene expressions of Helicobacter pylori%具有cagA、vacA基因的幽门螺杆菌及其表达产物的研究

    Institute of Scientific and Technical Information of China (English)

    陈肖肖; 尚世强; 来庆和; 欧弼悠; 陈黎勤; 吴秀英; 章许平

    2003-01-01

    @@ 2000年4月~2001年5月,我们检测了浙江地区小儿感染的Hp菌株的cagA、vacA基因及其CagA、VacA蛋白的抗体阳性率,以研究Hp菌株的基因型与消化性溃疡(Peptic ulcer disease,PUD)和慢性胃炎(Chronic gastritis,CG)的相关性.

  4. Helicobacter pylori cag pathogenicity island (cagPAI involved in bacterial internalization and IL-8 induced responses via NOD1- and MyD88-dependent mechanisms in human biliary epithelial cells.

    Directory of Open Access Journals (Sweden)

    Wongwarut Boonyanugomol

    Full Text Available Helicobacter pylori infection has been proposed to be associated with various diseases of the hepatobiliary tract, including cancer of the bile duct epithelial cells (cholangiocarcinoma, CCA. The ability of H. pylori bacteria to cause pathogenic effects in these cells has, however, yet to be investigated. Given that the cag pathogenicity island (cagPAI is required for H. pylori pathogenesis in gastric epithelial cells, we investigated wild-type and cag mutant strains for their ability to adhere, be internalized and induce pro-inflammatory responses in two bile duct epithelial cell lines derived from cases of CCA. The findings from these experiments were compared to results obtained with the well-characterized AGS gastric cancer cell line. We showed that the cagPAI encodes factors involved in H. pylori internalization in CCA cells, but not for adhesion to these cells. Consistent with previous studies in hepatocytes, actin polymerization and α5β1 integrin may be involved in H. pylori internalization in CCA cells. As for AGS cells, we observed significantly reduced levels of NF-κB activation and IL-8 production in CCA cells stimulated with either cagA, cagL or cagPAI bacteria, when compared with wild-type bacteria. Importantly, these IL-8 responses could be inhibited via either pre-treatment of cells with antibodies to α5β1 integrins, or via siRNA-mediated knockdown of the innate immune signaling molecules, nucleotide oligomerization domain 1 (NOD1 and myeloid differentiation response gene 88 (MyD88. Taken together, the data demonstrate that the cagPAI is critical for H. pylori pathogenesis in bile duct cells, thus providing a potential causal link for H. pylori in biliary tract disease.

  5. Characterisation of full-length cDNA sequences provides insights into the Eimeria tenellatranscriptome

    Directory of Open Access Journals (Sweden)

    Amiruddin Nadzirah

    2012-01-01

    Full Text Available Abstract Background Eimeria tenella is an apicomplexan parasite that causes coccidiosis in the domestic fowl. Infection with this parasite is diagnosed frequently in intensively reared poultry and its control is usually accorded a high priority, especially in chickens raised for meat. Prophylactic chemotherapy has been the primary method used for the control of coccidiosis. However, drug efficacy can be compromised by drug-resistant parasites and the lack of new drugs highlights demands for alternative control strategies including vaccination. In the long term, sustainable control of coccidiosis will most likely be achieved through integrated drug and vaccination programmes. Characterisation of the E. tenella transcriptome may provide a better understanding of the biology of the parasite and aid in the development of a more effective control for coccidiosis. Results More than 15,000 partial sequences were generated from the 5' and 3' ends of clones randomly selected from an E. tenella second generation merozoite full-length cDNA library. Clustering of these sequences produced 1,529 unique transcripts (UTs. Based on the transcript assembly and subsequently primer walking, 433 full-length cDNA sequences were successfully generated. These sequences varied in length, ranging from 441 bp to 3,083 bp, with an average size of 1,647 bp. Simple sequence repeat (SSR analysis identified CAG as the most abundant trinucleotide motif, while codon usage analysis revealed that the ten most infrequently used codons in E. tenella are UAU, UGU, GUA, CAU, AUA, CGA, UUA, CUA, CGU and AGU. Subsequent analysis of the E. tenella complete coding sequences identified 25 putative secretory and 60 putative surface proteins, all of which are now rational candidates for development as recombinant vaccines or drug targets in the effort to control avian coccidiosis. Conclusions This paper describes the generation and characterisation of full-length cDNA sequences from E

  6. 儿童幽门螺杆菌及CagA阳性感染的临床研究

    Institute of Scientific and Technical Information of China (English)

    侯冰文; 翁秀金; 温勇辉

    2007-01-01

    目的 探讨非侵入性检查方法对儿童幽门螺杆菌(H.pylori)的诊断及治疗价值.方法 对2004年10月至2005年12月在梅县人民医院门诊及住院154例慢性反复腹痛患儿进行粪便幽门螺杆菌抗原(HPSA)血清(H.pylori)抗体(HP-Ab)及产细胞毒素相关蛋白(CagA)、H.pylori检查测验,并对CagA阳性患者于短程三联抗H.pylori干预治疗.结果 154例患儿中H.pylori阳性33.8%(52/154),CagA阳性61.5%(32/52).H.pylori阳性及CagA阳性者以上腹疼痛,恶心呕吐多于H.pylori阴性患者,但它们之间差异无显著性,P>0.05;H.pylori阳性及CagA阳性与H.pylori阴性者病程上差异无显著性,P>0.05.对CagA阳性干预治疗后4周临床症状消失达90.6%(29/32),HPSA转阴率为87.5(28/32),结论 H.pylori阳性及CagA阳性与否不能以临床表现作为判断标准,H.pylori及CagA的检测可作为对儿童特别是幼儿诊断H.pylori感染及治疗后复查,简便,患儿易接受,特别适用基层的一种非侵入性检测方法.

  7. Association between cag-pathogenicity island in Helicobacter pylori isolates from peptic ulcer, gastric carcinoma, and nonulcer dyspepsia subjects with histological changes

    Institute of Scientific and Technical Information of China (English)

    Mahaboob Ali; Aleem A Khan; Santosh K Tiwari; Niyaz Ahmed; L Venkateswar Rao; CM Habibullah

    2005-01-01

    AIM: To investigate the presence of the cay-pathogenicity island and the associated histological damage caused by strains with complete cay-PAI and with partial deletions in correlation to the disease status.METHODS: We analyzed the complete cag-PAI of 174representative Helicobacter pylori (H pylori ) clinical isolates obtained from patients with duodenal ulcer,gastric ulcer, gastric cancer, and non-ulcer dyspepsia using eight different oligonucleotide primers viz cagA1,cagA2, cagAP1, cagAP2, cagE, cagT, LEC-1, LEC-2spanning five different loci of the whole cag-PAI by polymerase chain reaction (PCR).RESULTS: The complete screening of the genes comprising the cag-PAI showed that larger proportions of subjects with gastric ulcer (97.8%) inhabited strains with complete cag-PAI, followed by gastric cancer (85.7%),non-ulcer dyspepsia (7.1%), and duodenal ulcer (6.9%),significant differences were found in the percentagedistribution of the genes in all the clinical groups studied.It was found that strains with complete cag-PAI were able to cause severe histological damage than with the partially deleted ones.CONCLUSION: The cay-PAI is a strong virulent marker in the disease pathogenesis as it is shown that a large number of those infected with strain with complete cag-PAI had one or the other of the irreversible gastric pathologies and interestingly 18.5% of them developed gastric carcinoma. The presence of an intact cayPAI correlates with the development of more severe pathology, and such strains were found more frequently in patients with severe gastroduodenal disease. Partial deletions of the cag-PAI appear to be sufficient to render the organism less pathogenic.

  8. The Role of H. pylori CagA in Regulating Hormones of Functional Dyspepsia Patients

    Directory of Open Access Journals (Sweden)

    Wang-Ping Meng

    2016-01-01

    Full Text Available Helicobacter pylori (H. pylori, Hp colonizes the stomachs of approximately 20%–80% of humans throughout the world. The Word Healthy Organization (WHO classified H. pylori as a group 1 carcinogenic factor in 1994. Recently, an increasing number of studies has shown an association between H. pylori infection and various extragastric diseases. Functional dyspepsia (FD is considered a biopsychosocial disorder with multifactorial pathogenesis, and studies have shown that infection with CagA-positive H. pylori strains could explain some of the symptoms of functional dyspepsia. Moreover, CagA-positive H. pylori strains have been shown to affect the secretion of several hormones, including 5-HT, ghrelin, dopamine, and gastrin, and altered levels of these hormones might be the cause of the psychological disorders of functional dyspepsia patients. This review describes the mutual effects of H. pylori and hormones in functional dyspepsia and provides new insight into the pathogenesis of functional dyspepsia.

  9. Composition, structure and function of the Helicobacter pylori cag pathogenicity island encoded type IV secretion system.

    Science.gov (United States)

    Backert, Steffen; Tegtmeyer, Nicole; Fischer, Wolfgang

    2015-01-01

    Many Gram-negative pathogens harbor type IV secretion systems (T4SS) that translocate bacterial virulence factors into host cells to hijack cellular processes. The pathology of the gastric pathogen Helicobacter pylori strongly depends on a T4SS encoded by the cag pathogenicity island. This T4SS forms a needle-like pilus, and its assembly is accomplished by multiple protein-protein interactions and various pilus-associated factors that bind to integrins followed by delivery of the CagA oncoprotein into gastric epithelial cells. Recent studies revealed the crystal structures of six T4SS proteins and pilus formation is modulated by iron and zinc availability. All these T4SS interactions are crucial for deregulating host signaling events and disease progression. New developments in T4SS functions and their importance for pathogenesis are discussed.

  10. Clinical relevance of Helicobacter pylori vacA and cagA genotypes in gastric carcinoma.

    Science.gov (United States)

    Ferreira, Rui M; Machado, José C; Figueiredo, Ceu

    2014-12-01

    Helicobacter pylori infection is the major etiological factor of gastric carcinoma. This disease is the result of a long, multistep, and multifactorial process, which occurs only in a small proportion of patients infected with H. pylori. Gastric carcinoma development is influenced by host genetic susceptibility factors, environmental factors, and H. pylori virulence. H. pylori is genetically highly variable, and variability that affects H. pylori virulence factors may be useful to identify strains with different degrees of pathogenicity. This review will focus on VacA and CagA that have polymorphic regions that impact their functional properties. The characterization of H. pylori vacA and cagA-associated could be useful for identifying patients at highest risk of disease, who could be offered H. pylori eradication therapy and who could be included in programs of more intensive surveillance in an attempt to reduce gastric carcinoma incidence.

  11. Antibiotic resistance and cagA gene correlation: A looming crisis of Helicobacter pylori

    Institute of Scientific and Technical Information of China (English)

    Adnan Khan; Amber Farooqui; Hamid Manzoor; Syed Shakeel Akhtar; Muhammad Saeed Quraishy; Shahana Urooj Kazmi

    2012-01-01

    AIM:To determine antibiotic resistance of Helicobacter pylori (H.pylori) in Pakistan and its correlation with host and pathogen associated factors.METHODS:A total of 178 strains of H.pylori were isolated from gastric biopsies of dyspeptic patients.Susceptibility patterns against first and second-line antibiotics were determined and trends of resistance were analyzed in relation to the sampling period,gastric conditions and cagA gene carriage.The effect of cagA gene on the acquisition of resistance was investigated by mutant selection assay.RESULTS:The observations showed that monoresistant strains were prevalent with rates of 89% for metronidazole,36% for clarithromycin,37% for amoxicillin,18.5% for ofloxacin and 12% for tetracycline.Furthermore,clarithromycin resistance was on the rise from 2005 to 2008 (32% vs 38%,P =0.004) and it is significantly observed in non ulcerative dyspeptic patients compared to gastritis,gastric ulcer and duodenal ulcer cases (53% vs 20%,18% and 19%,P =0.000).On the contrary,metronidazole and ofloxacin resistance were more common in gastritis and gastric ulcer cases.Distribution analysis and frequencies of resistant mutants in vitro correlated with the absence of cagA gene with metronidazole and ofloxacin resistance.CONCLUSION:The study confirms the alarming levels of antibiotic resistance associated with the degree of gastric inflammation and cagA gene carriage in H.pylori strains.

  12. The Helicobacter pylori cytotoxin CagA is essential for suppressing host heat shock protein expression.

    Science.gov (United States)

    J Lang, Ben; J Gorrell, Rebecca; Tafreshi, Mona; Hatakeyama, Masanori; Kwok, Terry; T Price, John

    2016-05-01

    Bacterial infections typically elicit a strong Heat Shock Response (HSR) in host cells. However, the gastric pathogen Helicobacter pylori has the unique ability to repress this response, the mechanism of which has yet to be elucidated. This study sought to characterize the underlying mechanisms by which H. pylori down-modulates host HSP expression upon infection. Examination of isogenic mutant strains of H. pylori defective in components of the type IV secretion system (T4SS), identified the secretion substrate, CagA, to be essential for down-modulation of the HSPs HSPH1 (HSP105), HSPA1A (HSP72), and HSPD1 (HSP60) upon infection of the AGS gastric adenocarcinoma cell line. Ectopic expression of CagA by transient transfection was insufficient to repress HSP expression in AGS or HEK293T cells, suggesting that additional H. pylori factors are required for HSP repression. RT-qPCR analysis of HSP gene expression in AGS cells infected with wild-type H. pylori or isogenic cagA-deletion mutant found no significant change to account for reduced HSP levels. In summary, this study identified CagA to be an essential bacterial factor for H. pylori-mediated suppression of host HSP expression. The novel finding that HSPH1 is down-modulated by H. pylori further highlights the unique ability of H. pylori to repress the HSR within host cells. Elucidation of the mechanism by which H. pylori achieves HSP repression may prove to be beneficial in the identification of novel mechanisms to inhibit the HSR pathway and provide further insight into the interactions between H. pylori and the host gastric epithelium.

  13. E-PILE+BMIA/CAG method for calculating electromagnetic scattering from buried objects below rough surface%计算粗糙地面下方埋藏目标复合散射的E-PILE+BMIA/CAG算法

    Institute of Scientific and Technical Information of China (English)

    姬伟杰; 童创明

    2013-01-01

    In order to calculate quickly the composite electromagnetic scattering from buried objects below a large dimensional rough surface, the E-PILE+BMIA/CAG method is presented by combining the extended propagation-inside-layer expansion (PILE) and banded matrix iterative approach canonical grid (BMIA/CAG). The actual ground surface is simulated by a random surface with Gauss spectrum, and the tapered incident wave is chosen to reduce the truncation error. The composite scattering from an infinite length 2-D cylinder buried under the 1-D randomly rough surface with lossy media is calculated by using E-PILE+BMIA/CAG. The validity and convergence of this method are verified by comparing the result with that of the existing method. The coupling effect between the surface and the object and the roughness is studied. Finally, the scattering pattern of buried targets below a rough surface is studied. The numerical results provide a guide in the application of the ground penetrating radar.%为快速获取电大尺寸随机粗糙面下方埋藏目标的电磁散射特性,基于层内波传播展开法(propagation-inside-layer expansion,PILE)和带状矩阵迭代及规范网格法(banded matrix iterative approach canonical grid,BMIA/CAG),提出了结合带状矩阵迭代及规范网格法的扩展层内波传播展开法(E--PILE+ BMIA/CAG).数值计算过程中,以高斯随机粗糙面模拟实际地表面,并引入锥形入射波以减小人为截断粗糙面所引起的计算误差.为验证算法的有效性和收敛性,计算了一维介质粗糙面下方埋藏无限长二维介质圆柱目标的散射特性,研究了目标与粗糙面之间的相互作用,并与已有算法结果进行比较.最后计算了大入射角情况时地面下方埋藏目标的复合散射特性.该研究成果对于目标探测等领域具有一定的理论指导价值.

  14. A Central Limit Theorem for Repeating Patterns

    CERN Document Server

    Abrams, Aaron; Landau, Henry; Landau, Zeph; Pommersheim, James

    2012-01-01

    This note gives a central limit theorem for the length of the longest subsequence of a random permutation which follows some repeating pattern. This includes the case of any fixed pattern of ups and downs which has at least one of each, such as the alternating case considered by Stanley in [2] and Widom in [3]. In every case considered the convergence in the limit of long permutations is to normal with mean and variance linear in the length of the permutations.

  15. Estimation of genome length

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The genome length is a fundamental feature of a species. This note outlined the general concept and estimation method of the physical and genetic length. Some formulae for estimating the genetic length were derived in detail. As examples, the genome genetic length of Pinus pinaster Ait. and the genetic length of chromosome Ⅵ of Oryza sativa L. were estimated from partial linkage data.

  16. Helicobacter pylori CagA triggers expression of the bactericidal lectin REG3γ via gastric STAT3 activation.

    Directory of Open Access Journals (Sweden)

    Kai Syin Lee

    Full Text Available BACKGROUND: Most of what is known about the Helicobacter pylori (H. pylori cytotoxin, CagA, pertains to a much-vaunted role as a determinant of gastric inflammation and cancer. Little attention has been devoted to potential roles of CagA in the majority of H. pylori infected individuals not showing oncogenic progression, particularly in relation to host tolerance. Regenerating islet-derived (REG3γ encodes a secreted C-type lectin that exerts direct bactericidal activity against Gram-positive bacteria in the intestine. Here, we extend this paradigm of lectin-mediated innate immunity, showing that REG3γ expression is triggered by CagA in the H. pylori-infected stomach. METHODOLOGY/PRINCIPAL FINDINGS: In human gastric mucosal tissues, REG3γ expression was significantly increased in CagA-positive, compared to CagA-negative H. pylori infected individuals. Using transfected CagA-inducible gastric MKN28 cells, we recapitulated REG3γ induction in vitro, also showing that tyrosine phosphorylated, not unphosphorylated CagA triggers REG3γ transcription. In concert with induced REG3γ, pro-inflammatory signalling downstream of the gp130 cytokine co-receptor via the signal transducer and activator of transcription (STAT3 and transcription of two cognate ligands, interleukin(IL-11 and IL-6, were significantly increased. Exogenous IL-11, but not IL-6, directly stimulated STAT3 activation and REG3γ transcription. STAT3 siRNA knockdown or IL-11 receptor blockade respectively abrogated or subdued CagA-dependent REG3γ mRNA induction, thus demonstrating a requirement for uncompromised signalling via the IL-11/STAT3 pathway. Inhibition of the gp130-related SHP2-(Ras-ERK pathway did not affect CagA-dependent REG3γ induction, but strengthened STAT3 activation as well as augmenting transcription of mucosal innate immune regulators, IL-6, IL-8 and interferon-response factor (IRF1. CONCLUSIONS/SIGNIFICANCE: Our results support a model of CagA-directed REG3

  17. Quantum repeated games revisited

    CERN Document Server

    Frackiewicz, Piotr

    2011-01-01

    We present a scheme for playing quantum repeated 2x2 games based on the Marinatto and Weber's approach to quantum games. As a potential application, we study twice repeated Prisoner's Dilemma game. We show that results not available in classical game can be obtained when the game is played in the quantum way. Before we present our idea, we comment on the previous scheme of playing quantum repeated games.

  18. Telomere Length and Mortality

    DEFF Research Database (Denmark)

    Kimura, Masayuki; Hjelmborg, Jacob V B; Gardner, Jeffrey P

    2008-01-01

    Leukocyte telomere length, representing the mean length of all telomeres in leukocytes, is ostensibly a bioindicator of human aging. The authors hypothesized that shorter telomeres might forecast imminent mortality in elderly people better than leukocyte telomere length. They performed mortality...

  19. [Triplet repeat disease, with particular emphasis of spinal and bulbar muscular atrophy (SBMA)].

    Science.gov (United States)

    Sobue, G

    2000-12-01

    Spinal and bulbar muscular atrophy (SBMA) is an X-linked neurodegenerative disease caused by the expansion of a CAG repeat in the first exon of the androgen receptor (AR) gene. To date, eight CAG-repeat diseases have been identified, including spinal and bulbar muscular atrophy (SBMA). Huntington's disease (HD), dentatorubralpallidoluysian atrophy (DRPLA) and five spinocerebellar ataxias (SCAs 1, 2, 3, 6, 7). These disorders likely share a common pathogenesis caused by the gain of a toxic function associated with the expanded polyglutamine tract. Several mechanisms have been postulated as a pathogenic process for neurodegeneration caused by the expanded polyglutamine tract. Processing of the polyglutamine containing proteins by proteases liberate truncated polyglutamine tract, which may cause neurodegeneration as demonstrated in transgenic mice and transfected cells. In addition to cellular toxicity, truncated and expanded polyglutamine tracts have been shown to form intranuclear inclusions (NI). The NIs formed by the disease protein are a common pathological feature of these diseases. In SBMA, NIs containing AR protein have been observed in regions of SBMA central nervous system susceptible to degenerations. Transcriptional factors or their cofactors, such as cerb or creb-binding protein (CBP) sequestrated in the NI may alter the major intracellular transcriptional signal transduction, and ultimately may result in neuronal degeneration. The ubiquitin-proteasome pathway may also contribute to the pathogenesis of CAG-repeat diseases. As for the therapeutic strategies, many possibilities have been demonstrated. Overexpression of Hsp70 and Hsp40 chaperones act together to protect a cultured neuronal cell model of SBMA from a cellular toxicity of expanded polyglutamine tract.

  20. Prevalence of vacA, cagA and babA2 genes in Cuban Helicobacter pylori isolates

    Institute of Scientific and Technical Information of China (English)

    Lino E Torres; Karelia Melián; Arlenis Moreno; Jordis Alonso; Carlos A Sabatier; Mayrín Hernández; Ludisleydis Bermúdez; Boris L Rodríguez

    2009-01-01

    AIM: To investigate the prevalence of vacuolating cytotoxin ( vacA), cytotoxin associated gene A ( cagA) and blood adhesion binding antigen ( babA2) genotypes of Helicobacter pylori ( H pylori) isolates from Cuban dyspeptic patients. METHODS: DNA was extracted from H pylori-positive cultures taken from 130 dyspeptic patients. Genotyping was performed by PCR, using specific primers for vacA ( s1, s2, m1, m2), cagA and babA2 genes. Endoscopic observations and histological examinations were used to determine patient pathologies. RESULTS: vacA alleles s1, s2, m1 and m2 were detected in 96 (73.8%), 34 (26.2%), 75 (57.7%) and 52 isolates (40%), respectively, while the cagA gene was detected in 95 isolates (73.2%). One