A p53-independent role for the MDM2 antagonist Nutlin-3 in DNA damage response initiation.

BACKGROUND: The mammalian DNA-damage response (DDR) has evolved to protect genome stability and maximize cell survival following DNA-damage. One of the key regulators of the DDR is p53, itself tightly regulated by MDM2. Following double-strand DNA breaks (DSBs), mediators including ATM are recruited to the site of DNA-damage. Subsequent phosphorylation of p53 by ATM and ATM-induced CHK2 results in p53 stabilization, ultimately intensifying transcription of p53-responsive genes involved in DNA repair, cell-cycle checkpoint control and apoptosis. METHODS: In the current study, we investigated the stabilization and activation of p53 and associated DDR proteins in response to treatment of human colorectal cancer cells (HCT116p53+/+) with the MDM2 antagonist, Nutlin-3. RESULTS: Using immunoblotting, Nutlin-3 was observed to stabilize p53, and activate p53 target proteins. Unexpectedly, Nutlin-3 also mediated phosphorylation of p53 at key DNA-damage-specific serine residues (Ser15, 20 and 37). Furthermore, Nutlin-3 induced activation of CHK2 and ATM - proteins required for DNA-damage-dependent phosphorylation and activation of p53, and the phosphorylation of BRCA1 and H2AX - proteins known to be activated specifically in response to DNA damage. Indeed, using immunofluorescent labeling, Nutlin-3 was seen to induce formation of γH2AX foci, an early hallmark of the DDR. Moreover, Nutlin-3 induced phosphorylation of key DDR proteins, initiated cell cycle arrest and led to formation of γH2AX foci in cells lacking p53, whilst γH2AX foci were also noted in MDM2-deficient cells. CONCLUSION: To our knowledge, this is the first solid evidence showing a secondary role for Nutlin-3 as a DDR triggering agent, independent of p53 status, and unrelated to its role as an MDM2 antagonist

Assessment of fatty acids profile, oil yield and tocopherol content of four Almond cultivars grown in Eastern Morocco

The most cultivated varieties of almond in eastern Morocco: (Beldi (B), a local ecotype, Marcona (M) from Spain, Ferragnes-Ferraduel (F-F) and Fournat de Breznaud (FNB) from France), were studied during three consecutive crop years in order to evaluate variations in kernel oil yield, Fatty acid (FA) profile and physicochemical properties. For this purpose, extraction of almond oils was carried out by mechanical press. The yield of varieties B, M, (F-F) and FNB ranged between 50.68%- 54.33%, 41.46%- 52.59%, 47.70%-52.39% and 51.66%-56.10%, respectively. Oleic, linoleic and palmitic acids are the major fatty acids (FA) ranging between 57.54%- 72.90%, 17.80%- 29.81% and 6.50%-8.48%, respectively. Results showed a noticeable effect (P<0.001) of variety on Total phenolic content (TPC), oxidative stability and α-, β-, γ-, δ-tocopherol isomers; however, acidity and peroxide index, were affected with a lower manner by "variety" factor. In addition, all the analyzed parameters were highly (P<0.001) affected by climatic conditions of the crop year. In addition, the highest variations for the analyzed almond oils were recorded for their contents on α-tocopherol, γ-tocopherol, oleic and linoleic acids. According to the observed results, the couple Ferragnes-Ferraduel seems to produce stable and high quality almond oil compared to the other varieties

Enhanced neuronal Met signalling levels in ALS mice delay disease onset

Signalling by receptor tyrosine kinases (RTKs) coordinates basic cellular processes during development and in adulthood. Whereas aberrant RTK signalling can lead to cancer, reactivation of RTKs is often found following stress or cell damage. This has led to the common belief that RTKs can counteract degenerative processes and so strategies to exploit them for therapy have been extensively explored. An understanding of how RTK stimuli act at cellular levels is needed, however, to evaluate their mechanism of therapeutic action. In this study, we genetically explored the biological and functional significance of enhanced signalling by the Met RTK in neurons, in the context of a neurodegenerative disease. Conditional met-transgenic mice, namely Rosa26LacZ−stop−Met, have been engineered to trigger increased Met signalling in a temporal and tissue-specific regulated manner. Enhancing Met levels in neurons does not affect either motor neuron (MN) development or maintenance. In contrast, increased neuronal Met in amyotrophic lateral sclerosis (ALS) mice prolongs life span, retards MN loss, and ameliorates motor performance, by selectively delaying disease onset. Thus, our studies highlight the properties of RTKs to counteract toxic signals in a disease characterized by dysfunction of multiple cell types by acting in MNs. Moreover, they emphasize the relevance of genetically assessing the effectiveness of agents targeting neurons during ALS evolution

Human surfactant protein D alters oxidative stress and HMGA1 expression to induce p53 apoptotic pathway in eosinophil leukemic cell line

This article is made available through the Brunel Open Access Publishing Fund. Copyright: © 2013 Mahajan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Surfactant protein D (SP-D), an innate immune molecule, has an indispensable role in host defense and regulation of inflammation. Immune related functions regulated by SP-D include agglutination of pathogens, phagocytosis, oxidative burst, antigen presentation, T lymphocyte proliferation, cytokine secretion, induction of apoptosis and clearance of apoptotic cells. The present study unravels a novel ability of SP-D to reduce the viability of leukemic cells (eosinophilic leukemic cell line, AML14.3D10; acute myeloid leukemia cell line, THP-1; acute lymphoid leukemia cell lines, Jurkat, Raji; and human breast epithelial cell line, MCF-7), and explains the underlying mechanisms. SP-D and a recombinant fragment of human SP-D (rhSP-D) induced G2/M phase cell cycle arrest, and dose and timedependent apoptosis in the AML14.3D10 eosinophilic leukemia cell line. Levels of various apoptotic markers viz. activated p53, cleaved caspase-9 and PARP, along with G2/M checkpoints (p21 and Tyr15 phosphorylation of cdc2) showed significant increase in these cells. We further attempted to elucidate the underlying mechanisms of rhSP-D induced apoptosis using proteomic analysis. This approach identified large scale molecular changes initiated by SPD in a human cell for the first time. Among others, the proteomics analysis highlighted a decreased expression of survival related proteins such as HMGA1, overexpression of proteins to protect the cells from oxidative burst, while a drastic decrease in mitochondrial antioxidant defense system. rhSP-D mediated enhanced oxidative burst in AML14.3D10 cells was confirmed, while antioxidant, N-acetyl-L-cysteine, abrogated the rhSP-D induced apoptosis. The rhSP-D mediated reduced viability was specific to the cancer cell lines and viability of human PBMCs from healthy controls was not affected. The study suggests involvement of SP-D in host’s immunosurveillance and therapeutic potential of rhSP-D in the eosinophilic leukemia and cancers of other origins.Department of Biotechnology, Indi

SIGNALS: I. Survey description

SIGNALS, the Star formation, Ionized Gas, and Nebular Abundances Legacy Survey, is a large observing programme designed to investigate massive star formation and H II regions in a sample of local extended galaxies. The programme will use the imaging Fourier transform spectrograph SITELLE at the Canada–France–Hawaii Telescope. Over 355 h (54.7 nights) have been allocated beginning in fall 2018 for eight consecutive semesters. Once completed, SIGNALS will provide a statistically reliable laboratory to investigate massive star formation, including over 50 000 resolved H II regions: the largest, most complete, and homogeneous data base of spectroscopically and spatially resolved extragalactic H II regions ever assembled. For each field observed, three datacubes covering the spectral bands of the filters SN1 (363– 386 nm), SN2 (482–513 nm), and SN3 (647–685 nm) are gathered. The spectral resolution selected for each spectral band is 1000, 1000, and 5000, respectively. As defined, the project sample will facilitate the study of small-scale nebular physics and many other phenomena linked to star formation at a mean spatial resolution of ∼20 pc. This survey also has considerable legacy value for additional topics, including planetary nebulae, diffuse ionized gas, and supernova remnants. The purpose of this paper is to present a general outlook of the survey, notably the observing strategy, galaxy sample, and science requirementsThis research was based on observations obtained at the CFHT, which is operated from the summit of Mauna Kea by the National Research Council of Canada, the Institut National des Sciences de l’Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii

Signals: I. Survey description

SIGNALS, the Star formation, Ionized Gas, and Nebular Abundances Legacy Survey, is a large observing programme designed to investigate massive star formation and H II regions in a sample of local extended galaxies. The programme will use the imaging Fourier transform spectrograph SITELLE at the Canada–France–Hawaii Telescope. Over 355 h (54.7 nights) have been allocated beginning in fall 2018 for eight consecutive semesters. Once completed, SIGNALS will provide a statistically reliable laboratory to investigate massive star formation, including over 50 000 resolved H II regions: the largest, most complete, and homogeneous data base of spectroscopically and spatially resolved extragalactic H II regions ever assembled. For each field observed, three datacubes covering the spectral bands of the filters SN1 (363–386 nm), SN2 (482–513 nm), and SN3 (647–685 nm) are gathered. The spectral resolution selected for each spectral band is 1000, 1000, and 5000, respectively. As defined, the project sample will facilitate the study of small-scale nebular physics and many other phenomena linked to star formation at a mean spatial resolution of ∼20 pc. This survey also has considerable legacy value for additional topics, including planetary nebulae, diffuse ionized gas, and supernova remnants. The purpose of this paper is to present a general outlook of the survey, notably the observing strategy, galaxy sample, and science requirements

Lipidna peroksidacija i aktivnost antioksidativnih enzima u eritrocitima radnika profesionalno izloženih aluminiju

Current research indicates that lipid peroxidation could have a role in aluminium toxicity. The aim of this study was to asses lipid peroxidation and antioxidative enzyme activity in erythrocytes of workers occupationally exposed to aluminium. We investigated a group of 59 workers (Al group) exposed to aluminium fumes (contamination factor F=8.07 to 13.47, national maximal allowed concentration value is 2 mg m-3). The control group (C group) consisted of 75 subjects employed in lime production who had not been occupationally exposed to aluminium or any known toxic substance. Erythrocyte aluminium concentrations were significantly higher in the exposed group than controls [Al group (8.41±3.66) µg L-1, C group (5.60±0.86) µg L-1, p<0.001]. In the Al group, erythrocyte malondialdehyde concentration was also significantly higher [Al group (189.59±81.27) µmol L-1, C group (105.21±49.62) µmol L-1, p<0.001] and antioxidative enzyme activity reduced for glucoso-6-phosphatedehydrogenase [Al group (5.05±1.70) IU g-1 Hb, C group (12.53±4.12) IU g-1 Hb, p<0.001], glutathione reductase [Al group (1.41±0.56) IU g-1 Hb, C group (1.89±0.57) IU g-1 Hb, p<0.001], glutathione peroxidase [Al group (12.37±5.76) IU g-1 Hb, C group (15.54±4.85) IU g-1 Hb, p<0.001], catalase [Al group (116.76±26.60) IU g-1 Hb, C group (158.81±71.85) IU g-1 Hb, p<0.001] and superoxide dismutase [Al group (1175.8±149.9) IU mg-1 Hb, C group (1377.9±207.5) IU mg-1 Hb, p<0.001].Rezultati suvremenih istraživanja pokazuju da lipidna peroksidacija može imati važnu ulogu u toksičnosti aluminija. Cilj istraživanja bio je da se ispita lipidna peroksidacija i aktivnost antioksidativnih enzima u eritrocitima kod radnika profesionalno izloženih aluminiju. Ispitivanjem je obuhvaćena skupina od 59 radnika (Al skupina) profesionalno izloženih aluminiju (faktor onečišćenja F=8,07 do 13,47, nacionalna maksimalno dopuštena koncentracija je 2 mg m-3). Kontrolna skupina sastojala se od 75 osoba zaposlenih u proizvodnji vapna koje nikada nisu bile profesionalno izložene aluminiju ni drugim toksičnim tvarima. U skupini izloženoj aluminiju utvrđene su statistički signifikantno više koncentracije aluminija u eritrocitima nego u kontrolnoj skupini [Al skupina (8,41±3,66) µg L-1, kontrolna skupina (5,60±0,86) µg L-1, p<0,001]. U Al skupini utvrđene su statistički značajno više koncentracije malondialdehida u eritrocitima [Al skupina (189,59±81,27) µmol L-1, kontrolna skupina (105,21±49,62) µmol L-1, p<0,001]. Također, u Al skupini utvrđene su i statistički značajno niže aktivnosti antioksidativnih enzima u eritrocitima: glukozo- 6-fosfatdehidrogenaza [Al skupina (5,05±1,70) IU g-1 Hb, kontrolna skupina (12,53±4,12) IU g-1 Hb, p<0,001], glutationreduktaza [Al skupina (1,41±0,56) IU g-1 Hb, kontrolna skupina (1,89±0,57) IU g-1 Hb, p<0,001], glutationperoksidaza [Al skupina (12,37±5,76) IU g-1 Hb, kontrolna skupina (15,54±4,85) IU g-1 Hb, p<0,001], katalaza [Al skupina (116,76±26,60) IU g-1 Hb, kontrolna skupina (158,81±71,85) IU g-1 Hb, p<0,001] i superoksiddizmutaza [Al skupina (1175,8±149,9) IU mg-1 Hb, kontrolna skupina (1377,9±207,5) IU mg-1 Hb, p<0,001]

Identifying recombination hotspots in the HIV-1 genome

HIV-1 infection is characterised by the rapid generation of genetic diversity that facilitates viral escape from immune selection and antiretroviral therapy. Despite recombination's crucial role in viral diversity and evolution, little is known about the genomic factors that influence recombination between highly similar genomes. In this study, we use a minimally modified full length HIV-1 genome and high throughput sequence analysis to study recombination in gag and pol in T cells. We find that recombination is favoured at a number of recombination hotspots, where recombination occurs six times more frequently than at corresponding coldspots. Interestingly, these hotspots occur near important features of the HIV-1 genome, but do not occur at sites immediately around protease inhibitor or reverse transcriptase inhibitor drug resistance mutations. We show that the recombination hot and cold spots are consistent across five blood donors and are independent of co-receptor mediated entry. Finally, we check common experimental confounders and find that these are not driving the location of recombination hotspots. This is the first study to identify the location of recombination hotspots, between two similar viral genomes with great statistical power and under conditions that closely reflect natural recombination events amongst HIV-1 quasispecies