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

Bones in the heart skeleton of the otter (Lutra lutra)

In most mammalian species the cardiac skeleton is composed of coarse collagen fibres, fibrocartilage, and pieces of hyaline cartilage. Bone, the os cordis, is a regular constituent of the ruminant heart. The cardiac skeleton of the otter (Lutra lutra) has not previously been described. The skeleton in 30 otter hearts was studied by x-ray analysis and light microscopy. Serial sections were cut parallel to the atrioventricular plane and histochemical staining methods were performed to identify connective tissue fibres, glycosaminoglycans, mineral deposits, and bone. Age and sex of the animals under investigation were considered. The otter heart skeleton was composed of coarse collagen fibres with intercalated pieces of fibrous and/or hyaline cartilage, calcified cartilage, and lamellar bone with red or white marrow. Pieces of hyaline cartilage were not clearly defined: a perichondrial layer was missing and coarse connective tissue continuously transformed into fibrous and hyaline cartilage. In both sexes the amount of cartilage and bone were found to increase with age. Our results establish the presence of bony material in the heart skeleton of the otter, a small mammalian species. This finding indicates that differentiation of bone is not exclusively related to the size of the organ. Increasing amounts of calcified cartilage and bone correlated with increasing age

Selectivity in the Cyclization of Citronellal Introduced by Squalene Hopene Cyclase Variants

Bastian SA, Hammer S, Kreß N, Nestl BM, Hauer B. Selectivity in the Cyclization of Citronellal Introduced by Squalene Hopene Cyclase Variants. ChemCatChem. 2017;9(23):4364-4368

Randomised controlled trial to evaluate the influence of mHealth and eHealth skin cancer prevention education among young organ transplant recipients: the HIPPOlino intervention study

OBJECTIVES: To determine whether a multicomponent sun protection intervention programme (mHealth) for young organ transplant recipients (OTR) leads to a higher increase of preventive knowledge and behavioural change than an e-learning education programme (eHealth). DESIGN: Randomised controlled trial with one preintervention baseline survey and three follow-up surveys after 6 weeks, 6 and 12 months. Comparison of two different intervention schedules with a control group (CG). SETTING: Multicomponent sun protection trainings in Germany, the Netherlands and Austria between June 2013 and September 2015. PARTICIPANTS: Participants 137 OTRs (5–22 years of age, 61 females/76 males) participated in the study. INTERVENTIONS: (A) Intervention group 1 (IG1): personal training with subsequent forwarding of individual ultraviolet index-dependent sun protection recommendations via short message service (SMS); (B) intervention group 2 (IG2): e-learning training without SMS; (C) CG: regular information letters, online training after 1 year. OUTCOME MEASURES: Key questions were used to form a knowledge and a behavioural score. Behavioural strategies and knowledge were quantified through self-administered questionnaires. RESULTS: Analyses 6 weeks after the intervention showed a higher knowledge increase in both IG compared with the CG (IG1 to CG: OR 12.64, 95% CI 4.20 to 38.20; IG2 to CG: OR 2.59, 95% CI 0.95 to 7.04). Sun protection behaviour improved slightly but not significantly in both IG (IG1 to CG: OR 2.56, 95% CI 0.93 to 7.00; IG2 to CG: OR 1.22, 95% CI 0.45 to 3.32). One year after the intervention, no behavioural changes were observed in either IG compared with the CG. IG1 but not IG2 still scored significantly higher in sun protection knowledge than the CG 1 year after intervention (IG1 to CG: OR 4.46, 95% CI 1.48 to 13.43; IG2 to CG: OR 1.41, 95% CI 0.51 to 3.93). CONCLUSIONS: This multicomponent sun protection programme provides a promising strategy to increase sun protection knowledge and possibly also protective behaviour in young OTR. TRIAL REGISTRATION NUMBER: DRKS0001139

Co-targeting HSP90 alpha and CDK7 overcomes resistance against HSP90 inhibitors in BCR-ABL1+ leukemia cells

Abstract HSP90 has emerged as an appealing anti-cancer target. However, HSP90 inhibitors (HSP90i) are characterized by limited clinical utility, primarily due to the resistance acquisition via heat shock response (HSR) induction. Understanding the roles of abundantly expressed cytosolic HSP90 isoforms (α and β) in sustaining malignant cells’ growth and the mechanisms of resistance to HSP90i is crucial for exploiting their clinical potential. Utilizing multi-omics approaches, we identified that ablation of the HSP90β isoform induces the overexpression of HSP90α and extracellular-secreted HSP90α (eHSP90α). Notably, we found that the absence of HSP90α causes downregulation of PTPRC (or CD45) expression and restricts in vivo growth of BCR-ABL1+ leukemia cells. Subsequently, chronic long-term exposure to the clinically advanced HSP90i PU-H71 (Zelavespib) led to copy number gain and mutation (p.S164F) of the HSP90AA1 gene, and HSP90α overexpression. In contrast, acquired resistance toward other tested HSP90i (Tanespimycin and Coumermycin A1) was attained by MDR1 efflux pump overexpression. Remarkably, combined CDK7 and HSP90 inhibition display synergistic activity against therapy-resistant BCR-ABL1+ patient leukemia cells via blocking pro-survival HSR and HSP90α overexpression, providing a novel strategy to avoid the emergence of resistance against treatment with HSP90i alone

Induction of the Alternative NF-κB Pathway by Lymphotoxin αβ (LTαβ) Relies on Internalization of LTβ Receptor ▿ †

Several tumor necrosis factor receptor (TNFR) family members activate both the classical and the alternative NF-κB pathways. However, how a single receptor engages these two distinct pathways is still poorly understood. Using lymphotoxin β receptor (LTβR) as a prototype, we showed that activation of the alternative, but not the classical, NF-κB pathway relied on internalization of the receptor. Further molecular analyses revealed a specific cytosolic region of LTβR essential for its internalization, TRAF3 recruitment, and p100 processing. Interestingly, we found that dynamin-dependent, but clathrin-independent, internalization of LTβR appeared to be required for the activation of the alternative, but not the classical, NF-κB pathway. In vivo, ligand-induced internalization of LTβR in mesenteric lymph node stromal cells correlated with induction of alternative NF-κB target genes. Thus, our data shed light on LTβR cellular trafficking as a process required for specific biological functions of NF-κB