Bepridil exhibits anti‐leukemic activity associated with NOTCH1 pathway inhibition in chronic lymphocytic leukemia

Dysregulated NOTCH1 signaling, by either gene mutations or microenvironment interactions, has been increasingly linked to chronic lymphocytic leukemia (CLL). Thus, inhibiting NOTCH1 activity represents a potential therapeutic opportunity for this disease. Using gene expression‐based screening, we identified the calcium channel modulator bepridil as a new NOTCH1 pathway inhibitor. In primary CLL cells, bepridil induced selective apoptosis even in the presence of the protective stroma. Cytotoxic effects of bepridil were independent of NOTCH1 mutation and other prognostic markers. The antitumor efficacy of bepridil was associated with inhibition of NOTCH1 activity through a decrement in trans‐membrane and activated NOTCH1 protein levels with unchanged NOTCH2 protein levels. In a CLL xenotransplant model, bepridil significantly reduced the percentage of leukemic cells infiltrating the spleen via enhanced apoptosis and decreased NOTCH1 activation. In conclusion, we report in vitro and in vivo anti‐leukemic activity of bepridil associated with inhibition of the NOTCH1 pathway in CLL. These data provide a rationale for the clinical development of bepridil as anti‐NOTCH1 targeted therapy for CLL patients.     

Cardiac autonomic characteristics in infants sleeping with their head covered by bedclothes

The risk of Sudden Infant Death Syndrome is increased in infants sleeping with their head covered by bedding items. This study was designed to evaluate cardiac autonomic nervous controls in infants sleeping with the head covered by bedclothes. Sixteen healthy infants with a median age of 12 weeks (range 9-13 weeks) were recorded polygraphically for one night. While they slept in their usual supine position, a bedsheet was placed over their head for about 45 min. All infants were challenged with the head covered and with the head free during both rapid eye movement (REM) and non-rapid eye movement (NREM) sleep. Sleep, breathing and heart rate (HR) characteristics were recorded simultaneously, together with rectal and pericephalic temperatures. In both head-free and head-covered conditions, autoregressive spectral analysis of HR was evaluated as a function of sleep stages. During the head-covered periods, parasympathetic tonus decreased and sympathetic activity increased in both REM and NREM sleep. Compared with the head-free periods, the head-covered sleep periods were characterized by greater rectal (P = 0.012) and pericephalic temperatures (P = 0.002). Covering the infant's head with a bedsheet was associated with significant changes in autonomic balance. The finding could be related to an elevation in temperatures within the infant's microenvironment.     

Analysis of the OA1 gene reveals mutations in only one-third of patients with X-linked ocular albinism

The locus for ocular albinism type 1 (OA1) has been assignedto the Xp22.3 region through both linkage and deletion mapping.The disorder was found to be genetically homogeneous, as allinformative families showed convincing linkage data with markerson Xp22.3 and all identified deletions involved the same region.The OA1 gene was recently cloned and several intragenic deletionswere identified in affected individuals. We have characterizedthe genomic structure of the OA1 gene, which spans approximately40 kb of genomic DNA and contains nine exons. A highly polymorphicdinucleotide repeat was identified in intron 1, that providesa useful tool for molecular diagnosis. Knowledge of the intron/exonboundaries allowed us to search for point mutations in patients'genomic DNA. All nine exons of the OA1 gene, as well as the5' and 3' untranslated regions, were scanned for point mutationsin PCR-amplified DNA from 60 OA1 patients. The mutations identifiedinclude: two frameshifts and a splice site mutation leadingto truncated OA1 proteins; a deletion of a threonine codon atposition 290; and four missense mutations, two of which involveamino acids located within putative transmembrane domains. Twoof the mutations each occur in three apparently unrelated families,consistent with previous observations of a founder effect inOA1. Surprisingly, mutations were detected in only one-thirdof the patients (21 of 60) ascertained. We postulate that mutationsnot yet identified in either regulatory elements of the OA1gene, or in other gene(s) located within the same chromosomalregion, may be a common cause of X-linked ocular albinism.     

The tumor microenvironment drives NK cell metabolic dysfunction leading to impaired antitumor activity

NK cells represent key players capable of driving antitumor immune responses. However, the potent immunosuppressive activity of the tumor microenvironment (TME) may impair their effector function. Here, we strengthen the importance of metabolic interactions between NK cells and TME and propose metabolic dysfunction as one of the major mechanisms behind NK failure in cancer treatment. In particular, we described that TME has a direct negative impact on NK cell function by disrupting their mitochondrial integrity and function in pediatric and adult patients with primary and metastatic cancer. Our results will help to design new strategies aimed at increasing the NK cell antitumor efficacy by their metabolic reprogramming. In this regard, we reveal an unprecedented role of IL15 in the metabolic reprogramming of NK cells enhancing their antitumor functions. IL15 prevents the inhibitory effect of soluble factors present in TME and restores both the metabolic characteristics and the effector function of NK cells inhibited by exposure to malignant pleural fluid. Thus, we propose here that IL15 may be exploited as a new strategy to metabolically reprogram NK cells with the aim of increasing the efficacy of NK-based immunotherapy in a wide range of currently refractory adult and pediatric solid tumors.     

25(OH)D Levels in Relation to Gender,Overweight, Insulin Resistance,and Inflammation in a Cross-Sectional Cohort of Northern Italian Workers: Evidence in Support of Preventive Health Care Programs

Objective: In recent years, the welfare of workers and the prevention of chronic disabling diseases has become a topic of great interest. This study investigates serum levels of total 25-hydroxyvitamin D (25(OH)D) in a cohort of overweight–obese and insulin-resistant northern Italian indoor workers in apparent good health followed a nutritional education program.

Methods: An observational cross-sectional study on 385 patients (females = 291, males = 94), age range 18–69 years and body mass index (BMI) > 25 kg/m², was performed at the Department of Occupational Medicine Milan, Italy, latitude 45.465454 N. We evaluated nutritional intakes, occupational and leisure physical activity, anthropometric measurements, impedance evaluation, blood pressure, the presence of metabolic syndrome (MetS) and nonalcoholic fatty liver diseases (NAFLD) by fatty liver index (FLI). Hematologic and biochemical parameters and (25(OH)D) levels were evaluated from fasting blood samples.

Results: Only 10.91% of subjects had optimal values of 25(OH)D; 17.40% of the remaining 89.09% subjects were severely deficient, with no gender difference and insufficient intake of vitamin D. Only 28% declared leisure physical activity; 39.48% had metabolic syndrome and 62.60% had an FLI > 30. An inverse relationship between 25(OH)D levels and BMI was found, with a significant reduction of total 25(OH)D serum concentrations in winter. The homeostasis model assessment–insulin resistance (HOMA-IR) is positively related to BMI and inversely related to 25(OH)D concentrations. A positive correlation between vitamin D and leisure physical activity was found. At univariate analysis adjusted for age, gender and BMI, an inverse relationship between vitamin D and FLI was observed in both genders. The correlation between 25(OH)D levels, inflammation markers, BMI, and FLI showed an increased risk of cardiovascular disease in this cohort of workers.

Conclusion: Our results suggest the rationale for a large-scale screening program for vitamin D by means of easily implementable low-cost preventive supplementation.     

Chemical afferent vagal axotomy blocks re-intake after partial withdrawal of gastric food contents

Objectives: The aim of this study was to investigate the biological process by which animals regulate meal size. An experimental procedure for its study is to examine food re-intake after partial withdrawal of gastric food contents.

Methods: The aim of the present experiments was to investigate the role of vagal afferents in food re-intake after perivagal administration of capsaicin, a neurotoxin that specifically damages weakly myelinated or unmyelinated vagal sensory axons.

Results: In experiment 1, capsaicin-treated animals initially consumed higher amounts of food in comparison to controls (in first 24 hours) but their excess intake was compensated for in subsequent daily satiation tests. However, capsaicin treatment impaired the common short-term re-intake behavior observed in control rats after partial removal of gastric food nutrients, and the lesioned animals consumed significantly less food than had been withdrawn after completion of the initial meal; moreover, in this deficit condition, no counteraction was observed in subsequent repeated tests. This behavioral disturbance cannot be attributed to an indirect effect of capsaicin on gastric emptying volume, because the stomach contents were similar in both groups (Experiment 2).

Discussion: These findings are discussed in terms of the critical role played by vagal afferents in rapid visceral adjustments related to short-term food intake, as also observed in other gastrointestinal regulatory behaviors that require immediate processing of visceral sensory information.     

A PHD-polycomb repressive complex 2 triggers the epigenetic silencing of FLC during vernalization

Vernalization, the acceleration of flowering by winter, involves cold-induced epigenetic silencing of Arabidopsis FLC. This process has been shown to require conserved Polycomb Repressive Complex 2 (PRC2) components including the Su(z)12 homologue, VRN2, and two plant homeodomain (PHD) finger proteins, VRN5 and VIN3. However, the sequence of events leading to FLC repression was unclear. Here we show that, contrary to expectations, VRN2 associates throughout the FLC locus independently of cold. The vernalization-induced silencing is triggered by the cold-dependent association of the PHD finger protein VRN5 to a specific domain in FLC intron 1, and this association is dependent on the cold-induced PHD protein VIN3. In plants returned to warm conditions, VRN5 distribution changes, and it associates more broadly over FLC, coincident with significant increases in H3K27me3. Biochemical purification of a VRN5 complex showed that during prolonged cold a PHD-PRC2 complex forms composed of core PRC2 components (VRN2, SWINGER [an E(Z) HMTase homologue], FIE [an ESC homologue], MSI1 [p55 homologue]), and three related PHD finger proteins, VRN5, VIN3, and VEL1. The PHD-PRC2 activity increases H3K27me3 throughout the locus to levels sufficient for stable silencing. Arabidopsis PHD-PRC2 thus seems to act similarly to Pcl-PRC2 of Drosophila and PHF1-PRC2 of mammals. These data show FLC silencing involves changed composition and dynamic redistribution of Polycomb complexes at different stages of the vernalization process, a mechanism with greater parallels to Polycomb silencing of certain mammalian loci than the classic Drosophila Polycomb targets.