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

Pharmacological CFTR inhibition decreased CD11b expression and phagocytosis capacity in human primary macrophages

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Platinum compounds sensitize ovarian carcinoma cells to ABT-737 by modulation of the Mcl-1/Noxa axis.

International audienceOvarian cancer is the leading cause of death from gynecological cancer. The anti-apoptotic protein Bcl-x(L) is frequently overexpressed in ovarian carcinoma which correlates with chemotherapy resistance. It has been demonstrated that Bcl-x(L) cooperates with another anti-apoptotic protein, Mcl-1, to protect ovarian cancer cells against apoptosis, and that their concomitant inhibition induces massive cell death. Here, we examined the interest of ABT-737, a potent BH3-mimetic molecule targeting Bcl-x(L), both alone and in combination with Mcl-1 modulators, in ovarian cancer cell lines. As a single agent, ABT-737 was ineffective at promoting cell death in the four cell lines we tested in vitro. However, the specific inhibition of Mcl-1 by siRNA dramatically increased the sensitivity of chemoresistant cells to ABT-737. Platinum compounds also sensitize to ABT-737 by dose-dependently decreasing Mcl-1 expression or by increasing the expression of pro-apoptotic BH3-only proteins Noxa and, to a lower extent, Bim. Furthermore, we demonstrated that Noxa accumulation was involved in apoptosis occurring in response to the combination of ABT-737 and platinum compounds, since cells were protected from apoptosis by its silencing. Moreover, the combination was also highly cytotoxic ex vivo in sliced SKOV3 tumor nodes. However we observed in these slices a strong basal expression of Noxa and apoptotic cell death in response to ABT-737 alone. Therefore, we have revealed that the modulation of the Mcl-1/Noxa axis by platinum compounds results in a strong sensitization of chemoresistant ovarian carcinoma cells to ABT-737, which could constitute a promising therapeutic in these cancers

Bcl-x L and MCL-1 constitute pertinent targets in ovarian carcinoma and their concomitant inhibition is sufficient to induce apoptosis

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POSTER 26 sCD14 in macrophages from patients with cystic fibrosis: Origin and involvement in inflammatory functions

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Soluble CD14 acts as a DAMP in human macrophages: origin and involvement in inflammatory cytokine/chemokine production

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NF-κB activation in FL-N/35 tumors.

<p>(A) Immunohistochemical staining of p65 NF-κB subunit (brown) in FL-N/35 and spontaneous tumors. Arrows point to nuclear localization of p65, indicative of NF-κB activation. Nuclei are counterstained in blue. Quantification of p65 translocation is presented as mean+/− SEM of three independent experiments (**p<0.001). (B) p100, p52 protein levels in tumors and peritumoral regions of FL-N/35 mice livers. Processing of p100 to p52 is indicative of noncanonical NF-κB signaling. (C). RT-qPCR analysis of CXCL10 mRNA expression in FL-N/35 tumors and corresponding peritumoral areas. (D) CXCL10 protein levels and corresponding quantification in tumors and peritumoral regions of FL-N/35 mice. PT = peritumoral, T: tumor. Numbers identify animals analyzed.</p

NS5B enzymatic activity is required for activation of lymphotoxin expression and signaling.

<p>(A) Expression of LTβ protein in exponentially growing Huh7 cells, Huh7 stably expressing NS5B (Huh7-NS5B) and Nneo/C-5B replicon (C-5B) (B) Expression of LTβ protein in HepaRG and HepaRG-NS5B doxycycline-inducible cells (HepaRG-iNS5B). (C) Expression of LTβ protein in exponentially growing Huh7 cells and in Huh7 stably expressing NS5B, treated with the NS5B polymerase inhibitor 2′-C-Methylcytidine, as indicated. (D) Expression of LTβ protein in HepaRG, HepaRG-PMSCV, HepaRG-NS5B and HepaRG-NS5B G317V. (E) RT-qPCR analysis of LTα, LTβ, LTβR and CXCL10 mRNA expression in Huh7 and Huh7-NS5B treated or not by 2′-C-Methylcytidine. 18S rRNA served as normalization standard. (F) Immunofluorescence analysis of p65 nuclear translocation in Huh7 cells and Huh7-NS5B treated or not with 2′-C-Methylcytidine. (G) Expression of p100, p52 and LTβ proteins in Huh7 cells and Huh7 stably expressing NS5B treated or not with 2′-C-Methylcytidine. (H) RT-qPCR analysis of CXCL10 mRNA expression. Parental and NS5B-expressing Huh7 cells were transduced with retroviral vectors encoding shRNA directed against p65, LTβ or Firefly luciferase as control. Where appropriate, results are presented as mean+/− SEM of three separate experiments (student test, *p<0.01, **p<0.001).</p

Invalidation of the canonical NF-κB signaling reduces tumor incidence in HCV transgenic mice.

<p>(A) Tumor incidence in control, FL-N/35 Ikkβ^Flox/Flox and FL-N/35 Ikkβ^Δhep male mice as a function of age. All animals are of the same mixed C57Bl/6/C3H genetic background. *p<0.02 (two sided Fisher's exact test). (B) IKKβ protein expression in wild type, FL-N/35Ikkβ^F/F and FL-N/35 Ikkβ^F/F: Alb-Cre (FL-N/35 Ikkβ^Δhep) mice. (C) RT-qPCR analysis of NS5B mRNA expression in FL-N/35 and FL-N/35 Ikkβ<b>^Δhep</b> mice. Student's test showed no significant differences between the two groups.</p