Notch signaling sustains the expression of Mcl-1 and the activity of eIF4E to promote cell survival in CLL

In chronic lymphocytic leukemia (CLL), Notch1 and Notch2 signaling is constitutively activated and contributes to apoptosis resistance. We show that genetic inhibition of either Notch1 or Notch2, through small-interfering RNA, increases apoptosis of CLL cells and is associated with decreased levels of the anti-apoptotic protein Mcl-1. Thus, Notch signaling promotes CLL cell survival at least in part by sustaining Mcl-1 expression. In CLL cells, an enhanced Notch activation also contributes to the increase in Mcl-1 expression and cell survival induced by IL-4.Mcl-1 downregulation by Notch targeting is not due to reduced transcription or degradation by caspases, but in part, to increased degradation by the proteasome. Mcl-1 downregulation by Notch targeting is also accompanied by reduced phosphorylation of eukaryotic translation initiation factor 4E (eIF4E), suggesting that this protein is another target of Notch signaling in CLL cells.Overall, we show that Notch signaling sustains CLL cell survival by promoting Mcl-1 expression and eIF4E activity, and given the oncogenic role of these factors, we underscore the therapeutic potential of Notch inhibition in CLL

The CFHT Open Star Cluster Survey II -- Deep CCD Photometry of the Old Open Star Cluster NGC 6819

We present analysis of deep CCD photometry for the very rich, old open star cluster NGC 6819. These CFH12K data results represent the first of nineteen open star clusters which were imaged as a part of the CFHT Open Star Cluster Survey. We find a tight, very rich, main-sequence and turn-off consisting of over 2900 cluster stars in the V, B-V color-magnitude diagram (CMD). Main-sequence fitting of the un-evolved cluster stars with the Hyades star cluster yields a distance modulus of (m-M)v = 12.30 +/- 0.12, for a reddening of E(B-V) = 0.10. These values are consistent with a newly calculated theoretical stellar isochrone of age 2.5 Gyrs, which we take to be the age of the cluster. Detailed star counts indicate a much larger cluster extent (R = 9.5' +/- 1.0'), by a factor of ~2 over some previous estimates. Incompleteness tests confirm a slightly negatively sloped luminosity function extending to faint (V ~ 23) magnitudes which is indicative of a dynamically evolved cluster. Further luminosity function and mass segregation tests indicate that low mass objects (M < 0.65Mo) predominate in the outer regions of the cluster, 3.5 < R < 9.5. The estimation of the number of white dwarfs in NGC 6819 are in good agreement with the observed number. For those white dwarf candidates which pass both a statistical and image classification tests, we show comparisons to white dwarf isochrones and cooling models which suggest the need for spectroscopy to confirm the white dwarf nature of the brighter objects.Comment: 15 Figures and 6 Tables available in higher resolution from ADS. Accepted for Publication in AJ -- Kalirai et al. 2001b, 122, 266. Update

Perspectives of High Energy Neutrino Astronomy

This work discusses the perspectives to observe fluxes of high energy astrophysical neutrinos with the planned km3 telescopes. On the basis of the observations of GeV and TeV gamma-rays, and of ultra high energy cosmic rays, it is possible to construct well motivated predictions that indicate that the discovery of such fluxes is probable. However the range of these predictions is broad, and the very important opening of the ``neutrino window'' on the high energy universe is not guaranteed with the current design of the detectors. The problem of enlarging the detector acceptance using the same (water/ice Cherenkov) or alternative (acoustic/radio) techniques is therefore of central importance.Comment: Proceedings of "Very Large Volume neutrino Telescopes" workshop (Catania, november 2005). 16 pages, 10 figure

Phenolic content and antioxidant activity of einkorn and emmer sprouts and wheatgrass obtained under different radiation wavelengths

Abstract Sprouted seeds represent intriguing ready-to-eat micro-scale vegetables for the healthy food market, since they are tasty and rich in bioactive compounds. However, sprouts have been recently proposed as a source for the extraction and purification of several phytochemicals to be used in food supplementation or pharmaceutics. Recently, there has been an industrialization of sprout production, carried out indoor, often with use of artificial light, which have implications on biomass yield and composition, and on energetic and economic costs. This work investigates the effects of different radiation wavelengths from light emitting diodes (LED) on free and bound phenolics and antioxidant activity of sprouts and wheatgrass of einkorn (Triticum monococcum L. ssp. monococcum) and emmer ([(Triticum turgidum L. spp. dicoccum, (Schrank ex Schubler) Thell.)]). After 3 days of grain incubation in the dark, three light treatments were applied, labelled as BLUE (447 and 470 nm), RED (627 and 655 nm), and SUN (447, 470, 505, 530, 590, 627, 655 nm), for a same total photon flux density (PFD) of 200 μmol m−2 s−1. Sprouts were harvested at 5 days after sowing (DAS) and wheatgrass at 9 DAS. The effect of light was generally not significant for sprouts, much greater and species-specific for wheatgrass: BLUE in einkorn and RED in emmer generally increased free and total content of polyphenol (PC), tannins (TC), flavonoid (FC) and phenolic acids (PAs). The antioxidant activity was increased by BLUE in einkorn and decreased by RED in both species. BLUE and RED resulted energy saving compared to SUN

COX, Harvey, Turning East : The Promise and Peril of the New Orientalism

Excessive soil salinity is a major ecological and agronomical problem, the adverse effects of which are becoming a serious issue in regions where saline water is used for irrigation. Plants can employ regulatory strategies, such as DNA methylation, to enable relatively rapid adaptation to new conditions. In this regard, cytosine methylation might play an integral role in the regulation of gene expression at both the transcriptional and post-transcriptional levels. Rapeseed, which is the most important oilseed crop in Europe, is classified as being tolerant of salinity, although cultivars can vary substantially in their levels of tolerance. In this study, the Methylation Sensitive Amplified Polymorphism (MSAP) approach was used to assess the extent of cytosine methylation under salinity stress in salinity-tolerant (Exagone) and salinity-sensitive (Toccata) rapeseed cultivars. Our data show that salinity affected the level of DNA methylation. In particular methylation decreased in Exagone and increased in Toccata. Nineteen DNA fragments showing polymorphisms related to differences in methylation were sequenced. In particular, two of these were highly similar to genes involved in stress responses (Lacerata and trehalose-6-phosphatase synthase S4) and were chosen to further characterization. Bisulfite sequencing and quantitative RT-PCR analysis of selected MSAP loci showed that cytosine methylation changes under salinity as well as gene expression varied. In particular, our data show that salinity stress influences the expression of the two stress-related genes. Moreover, we quantified the level of trehalose in Exagone shoots and found that it was correlated to TPS4 expression and, therefore, to DNA methylation. In conclusion, we found that salinity could induce genome-wide changes in DNA methylation status, and that these changes, when averaged across different genotypes and developmental stages, accounted for 16.8% of the total site-specific methylation differences in the rapeseed genome, as detected by MSAP analysis

Organ culture and Reflectance Confocal Microscopy as new integrated tools for barrier rescue studies in inflammatory skin diseases

Here we present a new integrated approach to understand skin barrier recovery after physical (tape stripping, TS) or chemical (SDS) injury by combining human skin organ culture and Reflectance Confocal Microscopy (RCM). TS in vitro produced a complete removal of stratum corneum and lipids, a drastic decrease of structural and adhesion proteins, and an increase in cell proliferation. Epidermal recovery with either proliferation or differentiation rescue was observed after 18 hours, with no apoptotic cell detection. On the other hand, when skin organ cultures were exposed to 2% SDS, cellular junctions were disrupted and the expression of late differentiation markers decreased. Junctions repair was detected 24 hours after treatment, with the restoration of epidermal integrity. Both models (TP or SDS) showed the induction of immune-inflammatory markers, such as psoriasin, keratin 16, and the increase in Langerhans cell number. RCM confirmed all the morphological and structural features presented by the organ cultures, thus making this technique fast and easily applicable in the context of dermatological research. These results indicate that combination of skin organ models and RCM can be successfully used for the study of barrier perturbation in skin diseases, for toxicology tests, and for evaluating novel therapies

Expression of nuclear survivin in normal skin and squamous cell carcinoma: a possible role in tumor invasion

Background: Survivin is detected in few adult normal cells and it is highly expressed in cancer. Nuclear survivin facilitates cell cycle entry, while the mitochondrial pool protects cells from apoptosis. Survivin is overexpressed in keratinocyte stem cells (KSC) and protects them from apoptosis. Methods: As KSC are at the origin of squamous cell carcinoma (SCC), we evaluated survivin expression in normal and cancerous skin in vivo by immunohistochemistry and western blotting. HaCaT cells overexpressing survivin and wound-healing assay are used. Anova and Student-T tests are used for statistical analysis. Results: Survivin is localized both in the cytoplasm and in the nucleus of normal adult and young keratinocytes. Nuclear survivin is detected in one every 10/11 basal keratinocytes. When present in suprabasal cells, nuclear survivin is co-expressed with K10, but not with K15 or p75-neurotrophin-receptor (p75NTR), a transit amplifying cell marker. Nuclear, but not cytoplasmic survivin expression dramatically increases in actinic keratosis and in SCC in situ, as compared to normal epidermis, and it is highest in poorly differentiated SCC. In SCC tumors, nuclear survivin-positive cells are mainly K10/p75NTR-negative and K15-positive. In poorly differentiated tumors, survivin mostly localizes in the deep infiltrating areas. When overexpressed in keratinocytes, survivin increases cell migration. Conclusion: High survivin expression and the subcellular localization of survivin correlate with keratinocyte differentiation and are associated with undifferentiated and more invasive SCC phenotype

Liver enlargement predicts obstructive sleep apnea–hypopnea syndrome in morbidly obese women

Obstructive sleep apnea–hypopnea syndrome (OSAHS) is frequently present in patients with severe obesity, but its prevalence especially in women is not well defined. OSAHS and non-alcoholic fatty liver disease are common conditions, frequently associated in patients with central obesity and metabolic syndrome and are both the result of the accumulation of ectopic fat mass. Identifying predictors of risk of OSAHS may be useful to select the subjects requiring instrumental sleep evaluation. In this cross-sectional study, we have investigated the potential role of hepatic left lobe volume (HLLV) in predicting the presence of OSAHS. OSAHS was quantified by the apnea/hypopnea index (AHI) and oxygen desaturation index in a cardiorespiratory inpatient sleep study of 97 obese women [age: 47 ± 11 years body mass index (BMI): 50 ± 8 kg/m2]. OSAHS was diagnosed when AHI was ≥5. HLLV, subcutaneous and intra-abdominal fat were measured by ultrasound. After adjustment for age and BMI, both HLLV and neck circumference (NC) were independent predictors of AHI. OSAHS was found in 72% of patients; HLLV ≥ 370 cm3 was a predictor of OSAHS with a sensitivity of 66%, a specificity of 70%, a positive and negative predictive values of 85 and 44%, respectively (AUC = 0.67, p < 0.005). A multivariate logistic model was used including age, BMI, NC, and HLLV (the only independent predictors of AHI in a multiple linear regression analyses), and a cut off value for the predicted probability of OSAHS equal to 0.7 provided the best diagnostic results (AUC = 0.79, p < 0.005) in terms of sensitivity (76%), specificity (89%), negative and positive predictive values (59 and 95%, respectively). All patients with severe OSAHS were identified by this prediction model. In conclusion, HLLV, an established index of visceral adiposity, represents an anthropometric parameter closely associated with OSAHS in severely obese women

Isolation and Characterization of Squamous Cell Carcinoma-Derived Stem-like Cells: Role in Tumor Formation

In human epidermis, keratinocyte stem cells (KSC) are characterized by high levels of β1-integrin, resulting in the rapid adhesion to type IV collagen. Since epithelial tumors originate from KSC, we evaluated the features of rapidly adhering (RAD) keratinocytes derived from primary human squamous cell carcinoma of the skin (cSCC). RAD cells expressed higher levels of survivin, a KSC marker, as compared to non-rapidly adhering (NRAD) cells. Moreover, RAD cells proliferated to a greater extent and were more efficient in forming colonies than NRAD cells. RAD cells also migrated significantly better than NRAD cells. When seeded in a silicone chamber and grafted onto the back skin of NOD SCID mice, RAD cells formed tumors 2–4 fold bigger than those derived from NRAD cells. In tumors derived from RAD cells, the mitotic index was significantly higher than in those derived from NRAD cells, while Ki-67 and survivin expression were more pronounced in RAD tumors. This study suggests that SCC RAD stem cells play a critical role in the formation and development of epithelial tumors