Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

The Application of PCR Reaction for Identification of MHB Bacteria Species

This study characterizes mycorrhiza helper bacteria (MHB) from selected unpolluted locations as well as subjected to industrial emissions. To determine the species of bacteria isolated from the roots of ectomycorrhizal pine and birch, a method based on the sequence analysis of a 16S rRNA gene was used. The isolated bacteria were initially characterized by available biochemical methods and phenotypic observation. On the selected bacteria representatives isolation of DNA was performed, on which the PCR reaction was carried out. In this way amplified samples were automatically sequenced and the obtained results were compared to public databases. Among the isolated bacteria Pseudomonas fluorescens SBW25 and Burkholderia xenovorans LB400 species were dominant

The expression of RARs and RXRs in cervical cancer tissues HPV(+)

Introduction: Retinoids are essential for the maintenance of epithelial differentiation and play a fundamental role in chemoprevention of epithelial carcinogenesis. Retinoids exert their biological functions through nuclear receptors, retinoic acid receptor (RAR) and retinoid X receptor (RXR). The present study made an effort to analyze serum blood concentration of retinoids in women with cervical cancer as well as to assess an expression of RARs and RXRs in postoperative cervical cancer tissues HPV 16/18 positive. Material and methods: The study material included tissue samples of 42 squamous cell carcinoma, 7 samples of adenocarcinoma cervix uteri and 26 samples carcinoma in situ. The assessment of serum level of retinol, expression of retinoid receptors and presence of HPVs genome was performed. Results and conclusions: The mean retinol content in blood serum of patients with cervical cancer associated with HPV infection type 16 and/or 18 was lower than in controls. The level of RARα, RARβ and RXRβ mRNA expression was significantly decreased in the study group of women with CIS, squamous cell carcinoma and adenocarcinoma cervix to compare morphologically to the control women. In squamous cell carcinoma and carcinoma in situ were found to exhibit a decreased expression of RARα by about 75%, RARβ by 90%, RXRβ by 70% and 83% respectively compared to the control tissues. Among adenocarcinomas RARα, RARβ, RXRβ were expressed in 10%. In the study cancer tissues RARγ, RXRα and RXRγ were expressed on the same level as in the control tissues.Wprowadzenie: Retinoidy są ważnymi czynnikami biorącymi udział w regulacji różnicowania i proliferacji komórek nabłonkowych, a także odgrywają ważną rolę w ich chemioprofilaktyce i nowotworzeniu. Retinoidy wywierają swój efekt biologiczny poprzez receptory jądrowe RAR i RXR. Cel pracy: Celem przeprowadzonych badań była analiza stężenia retinolu w surowicy krwi kobiet z rakiem szyjki macicy oraz ocena ekspresji mRNA RAR i RXR w komórkach raka szyjki macicy zakażonych wirusem brodawczaka ludzkiego (HPV) typu 16. i 18. Materiał i metoda: Materiał badany obejmował 42 skrawki pooperacyjne tkanek raka płaskonabłonkowego, 7 skrawków gruczolakoraka szyjki macicy, a także 26 skrawków raka przedinwazyjnego. U osób, od których pochodziły skrawki tkanek, oceniono surowiczy poziom retinolu, a w tkankach ekspresję receptorów retinoidowych na poziomie mRNA i obecność sekwencji genomu HPV z zastosowaniem technik PCR. Wyniki i wnioski: Średnia zawartość retinolu w surowicy krwi pacjentek z rakiem szyjki macicy z towarzyszącym zakażeniem wirusem HPV typu 16. i 18. była niższa niż w grupie kontrolnej, ale nie znamienna statystycznie. Poziom RARα, RARβ oraz ekspresja mRNA dla RXRβ były znamiennie niższe w grupie badanej – u pacjentek z rakiem przedinwazyjnym (CIS), z rakiem płaskonabłonkowym i z gruczolakorakiem szyjki macicy, w porównaniu z kobietami z grupy kontrolnej. W przypadku raka płaskonabłonkowego i raka przedinwazyjnego stwierdzono zmniejszenie ekspresji RARα mniej więcej o 75%, RARβ o 90%, a RXRβ odpowiednio o 70% i 83% w porównaniu z komórkami tkanek kontrolnych. W przypadku gruczolakoraków ekspresja RARγ, RXRα and RXRγ była na poziomie takim jak w tkankach grupy kontrolnej

Clinical manifestations of intermediate allele carriers in Huntington disease

Objective: There is controversy about the clinical consequences of intermediate alleles (IAs) in Huntington disease (HD). The main objective of this study was to establish the clinical manifestations of IA carriers for a prospective, international, European HD registry. Methods: We assessed a cohort of participants at risk with <36 CAG repeats of the huntingtin (HTT) gene. Outcome measures were the Unified Huntington's Disease Rating Scale (UHDRS) motor, cognitive, and behavior domains, Total Functional Capacity (TFC), and quality of life (Short Form-36 [SF-36]). This cohort was subdivided into IA carriers (27-35 CAG) and controls (<27 CAG) and younger vs older participants. IA carriers and controls were compared for sociodemographic, environmental, and outcome measures. We used regression analysis to estimate the association of age and CAG repeats on the UHDRS scores. Results: Of 12,190 participants, 657 (5.38%) with <36 CAG repeats were identified: 76 IA carriers (11.56%) and 581 controls (88.44%). After correcting for multiple comparisons, at baseline, we found no significant differences between IA carriers and controls for total UHDRS motor, SF-36, behavioral, cognitive, or TFC scores. However, older participants with IAs had higher chorea scores compared to controls (p 0.001). Linear regression analysis showed that aging was the most contributing factor to increased UHDRS motor scores (p 0.002). On the other hand, 1-year follow-up data analysis showed IA carriers had greater cognitive decline compared to controls (p 0.002). Conclusions: Although aging worsened the UHDRS scores independently of the genetic status, IAs might confer a late-onset abnormal motor and cognitive phenotype. These results might have important implications for genetic counseling. ClinicalTrials.gov identifier: NCT01590589