CALR and ASXL1 mutations-based molecular prognostication in primary myelofibrosis: an international study of 570 patients

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Rpgrip1 is required for rod outer segment development and ciliary protein trafficking in zebrafish

The authors would like to thank the Royal Society of London, the National Eye Research Centre, the Visual Research Trust, Fight for Sight, the W.H. Ross Foundation, the Rosetrees Trust, and the Glasgow Children’s Hospital Charity for supporting this work. This work was also supported by the Deanship of Scientific Research at King Saud University for funding this research (Research Project) grant number ‘RGP – VPP – 219’.Mutations in the RPGR-interacting protein 1 (RPGRIP1) gene cause recessive Leber congenital amaurosis (LCA), juvenile retinitis pigmentosa (RP) and cone-rod dystrophy. RPGRIP1 interacts with other retinal disease-causing proteins and has been proposed to have a role in ciliary protein transport; however, its function remains elusive. Here, we describe a new zebrafish model carrying a nonsense mutation in the rpgrip1 gene. Rpgrip1homozygous mutants do not form rod outer segments and display mislocalization of rhodopsin, suggesting a role for RPGRIP1 in rhodopsin-bearing vesicle trafficking. Furthermore, Rab8, the key regulator of rhodopsin ciliary trafficking, was mislocalized in photoreceptor cells of rpgrip1 mutants. The degeneration of rod cells is early onset, followed by the death of cone cells. These phenotypes are similar to that observed in LCA and juvenile RP patients. Our data indicate RPGRIP1 is necessary for rod outer segment development through regulating ciliary protein trafficking. The rpgrip1 mutant zebrafish may provide a platform for developing therapeutic treatments for RP patients.Publisher PDFPeer reviewe

The Hubble Constant

I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give $H_0$ values of around 72-74km/s/Mpc , with typical errors of 2-3km/s/Mpc. This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67-68km/s/Mpc and typical errors of 1-2km/s/Mpc. The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.Comment: Extensively revised and updated since the 2007 version: accepted by Living Reviews in Relativity as a major (2014) update of LRR 10, 4, 200

Laboratory-Evolved Mutants of an Exogenous Global Regulator, IrrE from Deinococcus radiodurans, Enhance Stress Tolerances of Escherichia coli

The tolerance of cells toward different stresses is very important for industrial strains of microbes, but difficult to improve by the manipulation of single genes. Traditional methods for enhancing cellular tolerances are inefficient and time-consuming. Recently, approaches employing global transcriptional or translational engineering methods have been increasingly explored. We found that an exogenous global regulator, irrE from an extremely radiation-resistant bacterium, Deinococcus radiodurans, has the potential to act as a global regulator in Escherichia coli, and that laboratory-evolution might be applied to alter this regulator to elicit different phenotypes for E. coli.To extend the methodology for strain improvement and to obtain higher tolerances toward different stresses, we here describe an approach of engineering irrE gene in E. coli. An irrE library was constructed by randomly mutating the gene, and this library was then selected for tolerance to ethanol, butanol and acetate stresses. Several mutants showing significant tolerances were obtained and characterized. The tolerances of E. coli cells containing these mutants were enhanced 2 to 50-fold, based on cell growth tests using different concentrations of alcohols or acetate, and enhanced 10 to 100-fold based on ethanol or butanol shock experiments. Intracellular reactive oxygen species (ROS) assays showed that intracellular ROS levels were sharply reduced for cells containing the irrE mutants. Sequence analysis of the mutants revealed that the mutations distribute cross all three domains of the protein.To our knowledge, this is the first time that an exogenous global regulator has been artificially evolved to suit its new host. The successes suggest the possibility of improving tolerances of industrial strains by introducing and engineering exogenous global regulators, such as those from extremophiles. This new approach can be applied alone or in combination with other global methods, such as global transcriptional machinery engineering (gTME) for strain improvements

IDH1 and IDH2 mutation studies in 1473 patients with chronic-, fibrotic- or blast-phase essential thrombocythemia, polycythemia vera or myelofibrosis

In a multi-institutional collaborative project, 1473 patients with myeloproliferative neoplasms (MPN) were screened for isocitrate dehydrogenase 1 (IDH1)/IDH2 mutations: 594 essential thrombocythemia (ET), 421 polycythemia vera (PV), 312 primary myelofibrosis (PMF), 95 post-PV/ET MF and 51 blast-phase MPN. A total of 38 IDH mutations (18 IDH1-R132, 19 IDH2-R140 and 1 IDH2-R172) were detected: 5 (0.8%) ET, 8 (1.9%) PV, 13 (4.2%) PMF, 1 (1%) post-PV/ET MF and 11 (21.6%) blast-phase MPN (P<0.01). Mutant IDH was documented in the presence or absence of JAK2, MPL and TET2 mutations, with similar mutational frequencies. However, IDH-mutated patients were more likely to be nullizygous for JAK2 46/1 haplotype, especially in PMF (P=0.04), and less likely to display complex karyotype, in blast-phase disease (P<0.01). In chronic-phase PMF, JAK2 46/1 haplotype nullizygosity (P<0.01; hazard ratio (HR) 2.9, 95% confidence interval (CI) 1.7–5.2), but not IDH mutational status (P=0.55; HR 1.3, 95% CI 0.5–3.4), had an adverse effect on survival. This was confirmed by multivariable analysis. In contrast, in both blast-phase PMF (P=0.04) and blast-phase MPN (P=0.01), the presence of an IDH mutation predicted worse survival. The current study clarifies disease- and stage-specific IDH mutation incidence and prognostic relevance in MPN and provides additional evidence for the biological effect of distinct JAK2 haplotypes

Host Gene Expression Profiling of Dengue Virus Infection in Cell Lines and Patients

Dengue is the most prevalent mosquito-born viral disease affecting humans, yet there is, at present, no drug treatment for the disease nor are there any validated host targets for therapeutic intervention. Using microarray technology to monitor the response of virtually every human gene, we aimed to identify the ways in which humans interact with dengue virus during infection in order to discover new therapeutic targets that could be exploited to control viral replication. From the activated genes, we identified three pathways common to in vitro and in vivo infection; the NF-κB initiated immune pathway, the type I interferon pathway, and the ubiquitin proteasome pathway. We next found that inhibiting the ubiquitin proteasome pathway, or activating the type I interferon pathway, resulted in significant inhibition of viral replication. However, inhibiting the NF-κB initiated immune pathway had no effect on viral replication. We suggest that drugs that target the ubiquitin proteasome pathway may prove effective at killing the dengue virus, and, if used therapeutically, improve clinical outcome in dengue disease

The sinus tarsi approach in displaced intra-articular calcaneal fractures: a systematic review

Purpose: Although open reduction and internal fixation is currently considered the gold standard in surgical treatment of displaced intra-articular calcaneal fractures, various different approaches exist including the limited lateral approach. The aim of this systematic review was to combine the results of studies using the sinus tarsi approach, which is the most frequently applied limited lateral approach. Method: A literature search in the electronic databases of the Cochrane Library and Pubmed Medline, between January 1st 2000 to December 1st 2010, was conducted to identify studies in which the sinus tarsi approach or a modified sinus tarsi approach was utilized for the treatment of displaced intra-articular calcaneal fractures. The methodological quality of the included studies was assessed using the Coleman methodology score. Results: A total of eight case series reporting on 256 patients with 271 calcaneal fractures was identified. Overall good to excellent outcome was reached in three-quarters of all patients. An average complication rate of minor wound complications of 4.1% was reported and major wound complications in 0.7%. The need for a secondary subtalar arthrodesis occurred at an average rate of 4.3%. The average Coleman methodology score was 56.8 (range 39-72) points. Conclusion: The results, i.e. functional outcome and complication rates, of the sinus tarsi approach compare similarly or favourably to the extended lateral approach. Therefore, in the process of tailoring the best treatment modality to the right patient and the right fracture type, the sinus tarsi approach might be a valuable asset

Mutations with epigenetic effects in myeloproliferative neoplasms and recent progress in treatment: Proceedings from the 5th International Post-ASH Symposium

Immediately following the 2010 annual American Society of Hematology (ASH) meeting, the 5th International Post-ASH Symposium on Chronic Myelogenous Leukemia and BCR-ABL1-Negative Myeloproliferative Neoplasms (MPNs) took place on 7–8 December 2010 in Orlando, Florida, USA. During this meeting, the most recent advances in laboratory research and clinical practice, including those that were presented at the 2010 ASH meeting, were discussed among recognized authorities in the field. The current paper summarizes the proceedings of this meeting in BCR-ABL1-negative MPN. We provide a detailed overview of new mutations with putative epigenetic effects (TET oncogene family member 2 (TET2), additional sex comb-like 1 (ASXL1), isocitrate dehydrogenase (IDH) and enhancer of zeste homolog 2 (EZH2)) and an update on treatment with Janus kinase (JAK) inhibitors, pomalidomide, everolimus, interferon-α, midostaurin and cladribine. In addition, the new ‘Dynamic International Prognostic Scoring System (DIPSS)-plus' prognostic model for primary myelofibrosis (PMF) and the clinical relevance of distinguishing essential thrombocythemia from prefibrotic PMF are discussed