Reduction in Cholesterol Absorption Is Enhanced by Stearate-Enriched Plant Sterol Esters in Hamsters

Consumption of plant sterol esters reduces plasma LDL cholesterol concentration by inhibiting intestinal cholesterol absorption. Commercially available plant sterol esters are prepared by esterifying free sterols to fatty acids from edible plant oils such as canola, soybean, and sunflower. To determine the influence of the fatty acid moiety on cholesterol metabolism, plant sterol esters were made with fatty acids from soybean oil (SO), beef tallow (BT), or purified stearic acid (SA) and fed to male hamsters for 4 wk. A control group fed no plant sterol esters was also included. Hamsters fed BT and SA had significantly lower cholesterol absorption and decreased concentrations of plasma non-HDL cholesterol and liver esterified cholesterol, and significantly greater fecal sterol excretion than SO and control hamsters. Cholesterol absorption was lowest in hamsters fed SA (7.5%), whereas it was 72.9% in control hamsters. Cholesterol absorption was correlated with fecal sterol excretion (r = –0.72, P \u3c 0.001), liver cholesterol concentration (r = 0.88, P \u3c 0.001), and plasma non-HDL cholesterol concentration (r = 0.85, P \u3c 0.001). A multiple regression model that included each sterol ester type vs. cholesterol absorption indicated that intake of steryl stearate was the only dietary component that contributed significantly to the model (R2 = –0.75, P \u3c 0.001). Therefore, our results demonstrate that BT and SA are more effective than SO in reducing cholesterol absorption, liver cholesterol, and plasma non-HDL cholesterol concentration, suggesting that cardioprotective benefits can be achieved by consuming stearate-enriched plant sterol esters

Prioritizing multiple therapeutic targets in parallel using automated DNA-encoded library screening

AbstractThe identification and prioritization of chemically tractable therapeutic targets is a significant challenge in the discovery of new medicines. We have developed a novel method that rapidly screens multiple proteins in parallel using DNA-encoded library technology (ELT). Initial efforts were focused on the efficient discovery of antibacterial leads against 119 targets from Acinetobacter baumannii and Staphylococcus aureus. The success of this effort led to the hypothesis that the relative number of ELT binders alone could be used to assess the ligandability of large sets of proteins. This concept was further explored by screening 42 targets from Mycobacterium tuberculosis. Active chemical series for six targets from our initial effort as well as three chemotypes for DHFR from M. tuberculosis are reported. The findings demonstrate that parallel ELT selections can be used to assess ligandability and highlight opportunities for successful lead and tool discovery.</jats:p

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

Planet of the cavendish - understanding the domination

Those seeking to bring change to cultivars sold in the banana markets of the world have encountered major difficulties over the years. Change has been sought because of production difficulties caused by banana diseases such as Fusarium wilt or a desire to invigorate a stagnant market and obtain a competitive advantage by the introduction of diversity of product. Currently the world banana scene is dominated by cultivars from the Cavendish subgroup with their production in excess of 40% of total world production of banana and plantain combined, and in most western countries Cavendish is synonymous with banana. But Cavendish production usually necessitates very regular applications of pesticides, particularly fungicides for Mycosphaerella leaf spots control. So genetic resistance to these and other diseases would be very beneficial to minimizing costs of production, as well as reducing health risks to banana workers and the general population and minimizing impacts on the environment. In recent years, the overall market sales of some crops, such as tomatoes, have increased by providing diversity of cultivars to consumers. Can the same be done for banana? Perhaps a better understanding of how we have arrived at our current situation and the forces that have shaped our preference for Cavendish will allow us to plan more strategic crop improvement research which has enhanced chances of adoption by the banana industries of the world. A scoping study was recently undertaken in Australia to determine the current market opportunity for alternative cultivars and provide a roadmap for the industry to successfully develop this market. A multidisciplinary team reviewed the literature, surveyed the supply chain, analyzed gross margins and conducted consumer and sensory evaluations of 'new' cultivars. This has provided insight on why Cavendish dominates the market, which is the focus of this paper, and we believe will provide a solid foundation for future progress

Mutations of E3 Ubiquitin Ligase Cbl Family Members Constitute a Novel Common Pathogenic Lesion in Myeloid Malignancies

Purpose Acquired somatic uniparental disomy (UPD) is commonly observed in myelodysplastic syndromes (MDS), myelodysplastic/myeloproliferative neoplasms (MDS/MPN), or secondary acute myelogenous leukemia (sAML) and may point toward genes harboring mutations. Recurrent UPD11q led to identification of homozygous mutations in c-Cbl, an E3 ubiquitin ligase involved in attenuation of proliferative signals transduced by activated receptor tyrosine kinases. We examined the role and frequency of Cbl gene family mutations in MPN and related conditions. Methods We applied high-density SNP-A karyotyping to identify loss of heterozygosity of 11q in 442 patients with MDS, MDS/MPN, MPN, sAML evolved from these conditions, and primary AML. We sequenced c-Cbl, Cbl-b, and Cbl-c in patients with or without corresponding UPD or deletions and correlated mutational status with clinical features and outcomes. Results We identified c-Cbl mutations in 5% and 9% of patients with chronic myelomonocytic leukemia (CMML) and sAML, and also in CML blast crisis and juvenile myelomonocytic leukemia (JMML). Most mutations were homozygous and affected c-Cbl; mutations in Cbl-b were also found in patients with similar clinical features. Patients with Cbl family mutations showed poor prognosis, with a median survival of 5 months. Pathomorphologic features included monocytosis, monocytoid blasts, aberrant expression of phosphoSTAT5, and c-kit overexpression. Serial studies showed acquisition of c-Cbl mutations during malignant evolution. Conclusion Mutations in the Cbl family RING finger domain or linker sequence constitute important pathogenic lesions associated with not only preleukemic CMML, JMML, and other MPN, but also progression to AML, suggesting that impairment of degradation of activated tyrosine kinases constitutes an important cancer mechanism

Molecular Lesions Associated with Loss of Heterozygosity Identified in CMML

Abstract Abstract 416 Chronic myelomonocytic leukemia (CMML) is characterized by monocyte/monoblast proliferation, dysplastic features, progression to leukemia and poor prognosis. With the exception of rare cases of CMML with balanced PDGFRa or PDGFRb translocations, the molecular pathogenesis of the majority of CMML cases remains elusive. To date, somatic mutations pathogenic for CMML have not been identified, and large tyrosine kinase sequencing projects have been negative. The recent application of SNP-A as a karyotyping tool has allowed for more precise analyses of chromosomal defects and detection of copy-neutral loss of heterozygosity (CN-LOH). Previously, various recurrent areas of CN-LOH have been found in myeloid malignancies, but these lesions were particularly frequent in CMML. We have examined 68 patients with CMML and AML with antecedent CMML for recurrent areas of LOH, mapped mutations in genes contained within corresponding minimally affected regions, and examined their impact on clinical outcomes. We focused on Cbl, TET2 and RAS mutations and the resultant clinical and pathomorphologic phenotypes and outcomes associated with individual mutations. SNP-A-based karyotyping showed the presence of chromosomal aberrations in a larger proportion of cases than did metaphase cytogenetics: recurrent areas of somatic UPD were found in 49% of patients, with the most common shared lesions including UPD4q (n=6), UPD7q (n=6) and UPD11q (n=4). Initial identification of recurrent UPD11q and UPD4q and micro-deletions defining the smallest commonly affected areas led to the discovery of new mutations in CMML, including c-Cbl and TET2. In sum, we identified c-Cbl in 13%, TET2 in 49%, and RAS mutations in 10% of patients with CMML and sAML derived from CMML. LOH involving chromosome 7 was present in 18% of patients. All c-Cbl mutations were somatic and in the RING finger domain or linker sequence; 3/6 mutations were homozygous and one case with del11q harbored a hemizygous mutation. TET2 alterations were identified in 23 patients; in 26% of patients, both alleles were affected. However, no clinical differences were found between heterozygous and homozygous cases of TET2 mutations, suggesting a dominant negative effect. We also identified patients who harbored both TET2 and c-Cbl or RAS mutations demonstrating a multi-step pathogenesis of CMML. In addition, aberrant methylation at the CpG islands of promoters of TET2 (2 sites), c-Cbl (2 sites), b-Cbl (2 sites) and RAS (7 sites) was found to be relatively infrequent among patients. Intricate analysis of clinical and phenotypic features did not reveal pathognomonic phenotypes; however TET2 and c-Cbl mutations were associated with higher WBC (p=.027) or thrombocytopenia (p=.026), respectively and RAS mutations were associated with advanced disease (p=.027). Patients with LOH7q were included in our analysis as a separate group because they likely carried mutations in a putative candidate gene on 7q. In general, megakaryocyte nuclei displayed aberrant STAT5 staining in 31% of CMML cases (n=32) and correlated with morphologic dysplasia. Aberrant pSTAT5 staining suggestive of downstream pathways involving proliferative signals was present in 43% of TET2 mutated patients and 67% of c-Cbl mutants. None of the RAS mutants displayed aberrant STAT5 staining. Thus, aberrant STAT5 activation is not an obligatory feature of TET2 and RAS mutant cases, as opposed to the majority of c-Cbl mutant cases. There was no significant difference in survival between patients with TET2, c-Cbl and RAS mutations or those with LOH7q as compared to those without. Nevertheless, TET2 and c-Cbl mutant cases trended towards less favorable survival within lower-risk (<5% blasts) CMML, while no differences were seen in advanced cases, likely due to the uniformly poor survival in this group. Regardless of the presence of putative mutations, patients with LOH7q, including UPD7, shared a poor prognosis (7 vs. 11mo). In sum, our results characterize CMML as a disorder frequently associated with acquired chromosomal lesions, activated STAT5 signaling, genetic mutations in RAS, ubiquitin modification and TET2 pathways. Mutations present in these patients may help to clarify pathogenic pathways, and thereby develop directed therapies. Disclosures: No relevant conflicts of interest to declare