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Introduction According to the literature, 8% of the population claim to have an allergy to penicillin. Allergy tests show that 90% of these patients tolerate this molecule. Physicians working in the French Navy are faced with situations of real isolation and only have a limited number of antibiotics on board, the majority of which are penicillins. They must anticipate the risks linked to the prescription of antibiotics before the mission. However, there is no French recommendation, either military or civilian, intended for general practitioners clarifying the management and allergy assessments of patients alleging a history of allergy to penicillin. This study is the first to evaluate the professional practices of French military practitioners taking care of these patients. The main objective was to evaluate the proportion of sailors who reported an allergy to penicillin and who have never been referred for a consultation with an allergist, by studying the medical files of all the submariners working on the submersible ballistic nuclear submarines squadron in Brest. The secondary objective was to compare these data with the practices of Navy doctors by means of questionnaires. Material and methods Our work is composed of two parts: monocentric study of the digital and paper medical files of Brest submariners (n = 814) looking for allergist consultation reports in cases alleging an allergy to penicillin, then comparison with a multicentric collection of all Navy doctors’ practices collected by an anonymized questionnaire (n = 37 out of 53 practicing at the time of the study). Results Forty-seven subjects out of 814 alleged an allergy to penicillin (5.8%). Among them, only 12 (25.5%) had undergone allergy tests, of which 3 (6.4%) were confirmed to be allergic, with no cross-reaction between β-lactam antibiotics. Yet, according to the questionnaire, 25 doctors (67%) report referring their patients to an allergist and 16 (43%) report having had difficulties at sea in connection with the prescription of antibiotics for these patients. Conclusions A study of medical records shows that the allergic risk is not anticipated for 74.5% of patients labeled allergic, despite the difficulties encountered at sea. Standardization of practices within the French Navy is necessary to avoid the prescription of second-line antibiotics, less effective and sometimes unavailable on board, and to improve patient safety in isolation situations. In agreement with French military allergists, we propose, in this article, guidelines for a systematic exploration of allegations of allergy to penicillin in the French Navy.

The human genome contains more than 4.5 million inserts derived from transposable elements (TE), the result of recurrent waves of invasion and internal propagation throughout evolution. For new TE copies to be inherited, they must become integrated in the genome of the germline or preimplantation embryo, which requires that their source TE be expressed at these stages. Accordingly, many TEs harbor DNA binding sites for the pluripotency factors OCT4, NANOG, SOX2, KLFs and are transiently expressed during embryonic genome activation. Here, we describe how many primate-restricted TEs have additional binding sites for lineage-specific transcription factors driving their expression during human gastrulation and later steps of fetal development. These TE integrants serve as lineage-specific enhancers fostering the transcription, amongst other targets, of KRAB-zinc finger proteins of similar evolutionary age, which in turn corral the activity of TE-embedded regulatory sequences in an equally lineage-restricted fashion. Thus, TEs and their KZFP controllers play broad roles in shaping transcriptional networks during early human development.

International audience; ObjectivesThe subsurface ballistic missile nuclear submarine (SSBN) is an extreme professional environment in which personnel are both isolated and confined during patrols, which can last longer than 2 months. This environment is known to degrade submariners’ mood and cognition.MethodsThis exploratory, empirical study followed a cohort of 24 volunteer submariners. Dispositional mindfulness was assessed with the Freiburg Mindfulness Inventory, in order to identify two groups (mindful and non-mindful) and compare change in emotional state, interoception, and health behaviors during the patrol.ResultsOverall, psychological health deteriorated during the patrol. However, mindful submariners demonstrated better psychological adaptation and interoception than the non-mindful group. This was associated with better subjective health behaviors (sleeping and eating).ConclusionsDispositional mindfulness appears to protect against the negative effects of long-term containment in a professional environment, such as a submarine patrol. Our work highlights that mindfulness may help individuals to cope with stress in such situations. Developing mindfulness could also be an important preventive healthcare measure during quarantine imposed by the outbreak of a serious infectious disease.

Germ cells are essential to pass DNA from one generation to the next. In human reproduction, germ cell development begins with the specification of primordial germ cells (PGCs) and a failure to specify PGCs leads to human infertility. Recent studies have revealed that the transcription factor network required for PGC specification has diverged in mammals, and this has a significant impact on our understanding of human reproduction. Here, we evaluated the emerging epigenetic landscape during hPGC specification using a combination of in vivo and in vitro analysis of hPGCs/hPGC-like cells (hPGCLCs) and human embryonic stem cells (hESCs). Our data reveals that hominid restricted Transposable Elements (TEs) partly derived from ancient viruses are pre-bound by the transcription factors TFAP2C and NANOG in undifferentiated hESCs, become transcriptionally induced during PGC specification and undergo dynamic epigenetic reprogramming leading to increased chromatin accessibility, localized DNA demethylation and establishment of broad peaks of H3K27ac. Using KRAB mediated CRISPRi we show that blocking this remodeling has a significant impact on hPGC specification. In summary, our data reveals that human reproduction requires the establishment of an epigenetic landscape during hPGC specification driven by the acquisition of hominid-specific TEs that were derived from ancient viral infections that entered the hominid germline less than 5 million years ago.

The human forebrain has expanded in size and complexity compared to chimpanzees despite limited changes in protein-coding genes, suggesting that gene expression regulation is an important driver of brain evolution. Here, we identify a KRAB-ZFP transcription factor, ZNF558, that is expressed in human but not chimpanzee forebrain neural progenitor cells. ZNF558 evolved as a suppressor of LINE-1 transposons but has been co-opted to regulate a single target, the mitophagy gene SPATA18. ZNF558 plays a role in mitochondrial homeostasis, and loss-of-function experiments in cerebral organoids suggests that ZNF558 influences developmental timing during early human brain development. Expression of ZNF558 is controlled by the size of a variable number tandem repeat that is longer in chimpanzees compared to humans, and variable in the human population. Thus, this work provides mechanistic insight into how a cis-acting structural variation establishes a regulatory network that affects human brain evolution.

The human forebrain has expanded in size and complexity compared to that of chimpanzee despite limited changes in protein-coding genes, suggesting that gene regulation is an important driver of brain evolution. Here we identify a KRAB-ZFP transcription factor, ZNF558, that is expressed in human but not chimpanzee forebrain neural progenitor cells. ZNF558 evolved as a suppressor of LINE-1 transposons but has been co-opted to regulate the mitophagy gene SPATA18, supporting a link between mitochondrial homeostasis and cortical expansion. The unusual on-off switch for ZNF558 expression resides in a downstream variable number tandem repeat (VNTR) that is contracted in humans relative to chimpanzee. Our data reveal the brain-specific co-option of a transposon-controlling KRAB-ZFP and how a human-specific regulatory network is established by a cis-acting structural genome variation. This represents a previously undescribed genetic mechanism in the evolution of the human brain.

International audience; During cell division, maintenance of chromatin features from the parental genome requires their proper establishment on its newly synthetized copy. The loss of epigenetic marks within heterochromatin, typically enriched in repetitive elements, endangers genome stability and permits chromosomal rearrangements via recombination. However, how histone modifications associated with heterochromatin are maintained across mitosis remains poorly understood. KAP1 is known to act as a scaffold for a repressor complex that mediates local heterochromatin formation, and was previously demonstrated to play an important role during DNA repair. Accordingly, we investigated a putative role for this protein in the replication of heterochromatic regions. We first found that KAP1 associates with several DNA replication factors including PCNA, MCM3 and MCM6. We then observed that these interactions are promoted by KAP1 phosphorylation on serine 473 during S phase. Finally, we could demonstrate that KAP1 forms a complex with PCNA and the histone-lysine methyltransferase Suv39h1 to reinstate heterochromatin after DNA replication.

SETDB1 (SET Domain Bifurcated histone lysine methyltransferase 1) is a key lysine methyltransferase (KMT) required in embryonic stem cells (ESCs), where it silences transposable elements and DNA repeats via histone H3 lysine 9 tri-methylation (H3K9me3), independently of DNA methylation. The H3K9 methylation reader M-Phase Phosphoprotein 8 (MPP8) is highly expressed in ESCs and germline cells. Although evidence of a cooperation between H3K9 KMTs and MPP8 in committed cells has emerged, the interplay between H3K9 methylation writers and MPP8 in ESCs remains elusive. Here, we show that MPP8 interacts physically and functionally with SETDB1 in ESCs. Indeed, combining biochemical, transcriptomic and genomic analyses, we found that MPP8 and SETDB1 co-regulate a significant number of common genomic targets, especially the DNA satellite repeats. Together, our data point to a model in which the silencing of a class of repeated sequences in ESCs involves the cooperation between the H3K9 methylation writer SETDB1 and its reader MPP8. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.

Krüppel‐associated box (KRAB)‐containing zinc finger proteins (KZFPs) are encoded in the hundreds by the genomes of higher vertebrates, and many act with the heterochromatin‐inducing KAP1 as repressors of transposable elements (TEs) during early embryogenesis. Yet, their widespread expression in adult tissues and enrichment at other genetic loci indicate additional roles. Here, we characterized the protein interactome of 101 of the ~350 human KZFPs. Consistent with their targeting of TEs, most KZFPs conserved up to placental mammals essentially recruit KAP1 and associated effectors. In contrast, a subset of more ancient KZFPs rather interacts with factors related to functions such as genome architecture or RNA processing. Nevertheless, KZFPs from coelacanth, our most distant KZFP‐encoding relative, bind the cognate KAP1. These results support a hypothetical model whereby KZFPs first emerged as TE‐controlling repressors, were continuously renewed by turnover of their hosts’ TE loads, and occasionally produced derivatives that escaped this evolutionary flushing by development and exaptation of novel functions.

Lysine methyltransferases G9a and GLP (G9a-like protein) are highly homologous and form functional heterodimeric complexes that establish mono- and dimethylation on histone H3 lysine 9 (H3K9me1, H3K9me2) in euchromatin. Here, we describe unexpected distinct roles for G9a and GLP in skeletal muscle terminal differentiation. Indeed, gain- or loss-of-function assays in myoblasts showed, in agreement with previous reports, that G9a inhibits terminal differentiation. While GLP plays a more intricate role in muscle differentiation,in one hand, both GLP gain and loss of function inhibit late steps of differentiation; on the other hand, in contrast to G9a, GLP overexpression promotes abnormal precocious expression of muscle differentiation-specific genes already in proliferating myoblasts. In agreement, transcriptomic analysis indicates that G9a and GLP regulate different sets of genes. Thus, GLP, but not G9a, inhibits proteasome subunit-encoding genes expression, resulting in an inhibition of the proteasome activities. Subsequently, GLP, but not G9a, overexpression stabilizes MyoD that is likely to be responsible for muscle markers expression in proliferating myoblasts.

The aim of this article is to determine whether some of the urgent (24 hours) medical evacuations (MEDEVACs) (from French Navy surface ships in isolated situations but with an embarked medical officer) of patients suffering from minor surgical emergencies could have been avoided, and if so, which ones.This was a retrospective descriptive study of all MEDEVAC's performed between 2009 and 2014. This was done by an analysis of the records held at the French Naval Medical Headquarters that included both MEDEVAC signals and anonymized files called "Patient Movement Request."560 MEDEVACs were performed from French Navy surface ships which most had an embarked medical officer but which were in isolated situations. Only 34 (6.1%) of the total evacuations were suffering from minor surgical emergencies. The majority of these were nonurgent MEDEVAC's of whom 17 (50%) had no surgical procedure attempted on board. Seven (20%) underwent urgent MEDEVAC and only 2 of them had undergone the indicated therapeutic procedure on board. The most common pathology was displaced fracture of the fifth metacarpal (29.4%) before deep abscess (17.6%).Contrary to our initial expectation, the operational impact of minor surgical emergencies remains low, which might suggest that a French naval medical doctor's training is sufficient in this particular field. However, 50% of the overall evacuated patients and 71% of the "urgent" MEDEVACs (24 hours) did not undergo the indicated, simple surgical procedure before evacuation. The idea of introducing a specific training program for these procedures may therefore still have value.

The methylation of histone Lys residues by Lys methyltransferases (KMTs) regulates chromatin organization and either activates or represses gene expression, depending on the residue that is targeted. KMTs are emerging as key components in several cellular processes, and their deregulation is often associated with pathogenesis. Here, we review the current knowledge on the main KMTs that are associated with gene silencing: namely, those responsible for methylating histone H3 Lys 9 (H3K9), H3K27 and H4K20. We discuss their biochemical properties and the various mechanisms by which they are targeted to the chromatin and regulate gene expression, as well as new data on the interplay between them and other chromatin modifiers.

BCR ABL; International audience; BCR-ABL induces an intrinsic genetic instability in chronic myeloid leukemia (CML). The protein breast cancer 1, early onset (BRCA1)-associated protein 1 (BAP1) is a deubiquitinase interacting with the DNA repair regulator BRCA1 and is frequently inactivated in many cancers. Here, we report that BAP1 mRNA and protein levels are downregulated in a BCR-ABL1-expressing hematopoietic cell line (UT-7/11). A decrease of BAP1 transcripts is also observed in newly diagnosed CML patients. Moreover, BAP1 protein levels are low or undetectable in CD34(+) cells from CML patients at diagnosis as compared with CD34(+) cells from normal donors. In addition, BRCA1 protein level is reduced in BCR-ABL1-expressing UT-7/11 cells. Finally, the enforced expression of BAP1 is associated with BRCA1 protein deubiquitination and restoration. These results demonstrate BAP1 as a major link with the BCR-ABL-induced downregulation of BRCA1 in CML.

Significance: Methylation of histone H3 on lysine 9 and 27 (H3K9 and H3K27) are two epigenetic modifications that have been linked to several crucial biological processes, among which are transcriptional silencing and cell differentiation. Recent Advances: Deposition of these marks is catalyzed by H3K9 lysine methyltransferases (KMTs) and polycomb repressive complex 2, respectively. Increasing evidence is emerging in favor of a functional crosstalk between these two major KMT families. Critical Issues: Here, we review the current knowledge on the mechanisms of action and function of these enzymes, with particular emphasis on their interplay in the regulation of chromatin states and biological processes. We outline their crucial roles played in tissue homeostasis, by controlling the fate of embryonic and tissue-specific stem cells, highlighting how their deregulation is often linked to the emergence of a number of malignancies and neurological disorders. Future Directions: Histone methyltransferases are starting to be tested as drug targets. A new generation of highly selective chemical inhibitors is starting to emerge. These hold great promise for a rapid translation of targeting epigenetic drugs into clinical practice for a number of aggressive cancers and neurological disorders. Antioxid. Redox Signal. 22, 1365–1381.

Heterochromatic domains are enriched with repressive histone marks, including histone H3 lysine 9 methylation, written by lysine methyltransferases (KMTs). The pre-replication complex protein, origin recognition complex-associated (ORCA/LRWD1), preferentially localizes to heterochromatic regions in post-replicated cells. Its role in heterochromatin organization remained elusive. ORCA recognizes methylated H3K9 marks and interacts with repressive KMTs, including G9a/GLP and Suv39H1 in a chromatin context-dependent manner. Single-molecule pull-down assays demonstrate that ORCA-ORC (Origin Recognition Complex) and multiple H3K9 KMTs exist in a single complex and that ORCA stabilizes H3K9 KMT complex. Cells lacking ORCA show alterations in chromatin architecture, with significantly reduced H3K9 di- and tri-methylation at specific chromatin sites. Changes in heterochromatin structure due to loss of ORCA affect replication timing, preferentially at the late-replicating regions. We demonstrate that ORCA acts as a scaffold for the establishment of H3K9 KMT complex and its association and activity at specific chromatin sites is crucial for the organization of heterochromatin structure. DOI: http://dx.doi.org/10.7554/eLife.06496.001, eLife digest The genetic material inside cells is contained within molecules of DNA. In animals and other eukaryotes, the DNA is tightly wrapped around proteins called histones to form a compact structure known as chromatin. There are two forms of chromatin: loosely packed chromatin tends to contain genes that are highly active in cells, while tightly packed chromatin—called heterochromatin—tends to contain less-active genes. How tightly DNA is packed in chromatin can be changed by adding small molecules known as methyl tags to individual histone proteins. Enzymes called KMTs are responsible for attaching these methyl tags to a specific site on the histones. Before a cell divides, it duplicates its DNA and these methyl tags, so that they can be passed onto the newly formed cells. This enables the new cells to ‘remember’ which genes were inactive or active in the original cell. A protein known as ORCA associates with heterochromatin, but it is not clear what role it plays in controlling the structure of chromatin. Giri et al. studied ORCA and the KMTs in human cells. The experiments show that ORCA recognizes the methyl tags and binds to the KMTs in regions of heterochromatin, but not in regions where the DNA is more loosely packed. Next, Giri et al. used a technique called single-molecule pull-down, which is able to identify individual proteins within a group. These experiments showed that several KMT enzymes can bind to a single ORCA protein at the same time. ORCA stabilizes the binding of KMTs to chromatin, which enables the KMTs to modify the histones within it. Cells lacking ORCA had fewer methyl tags on their histones, which altered the structure of the chromatin. This also affected the timing with which DNA copying takes place in cells before the cell divides. Giri et al.'s findings suggest that ORCA acts as a scaffold for the KMTs and that its activity at specific sites on chromatin is important for the organization of heterochromatin. The next step is to identify the exact regions in the genome where the timing of DNA copying is regulated by ORCA. DOI: http://dx.doi.org/10.7554/eLife.06496.002

International audience; A genome-wide screen had previously shown that knocking down miR-98 and let-7g, two miRNAs of the let-7 family, leads to a dramatic increase in terminal myogenic differentiation. In the present paper, we report that a transcriptomic analysis of human myoblasts, where miR-98 was knocked down, revealed that approximately 240 genes were sensitive to miR-98 depletion. Among these potential targets of miR-98, we identified the transcriptional repressor E2F5 and showed that it is a direct target of miR-98. Knocking down simultaneously E2F5 and miR-98 almost fully restored normal differentiation, indicating that E2F5 is involved in the regulation of skeletal muscle differentiation. We subsequently show that E2F5 can bind to the promoters of two inhibitors of terminal muscle differentiation, ID1 (inhibitor of DNA binding 1) and HMOX1 (heme oxygenase 1), which decreases their expression in skeletal myoblasts. We conclude that miR-98 regulates muscle differentiation by altering the expression of the transcription factor E2F5 and, in turn, of multiple E2F5 targets.

Myogenic terminal differentiation is a well-orchestrated process starting with permanent cell cycle exit followed by muscle-specific genetic program activation. Individual SWI/SNF components have been involved in muscle differentiation. Here, we show that the master myogenic differentiation factor MyoD interacts with more than one SWI/SNF subunit, including the catalytic subunit BRG1, BAF53a and the tumor suppressor BAF47/INI1. Downregulation of each of these SWI/SNF subunits inhibits skeletal muscle terminal differentiation but, interestingly, at different differentiation steps and extents. BAF53a downregulation inhibits myotube formation but not the expression of early muscle-specific genes. BRG1 or BAF47 downregulation disrupt both proliferation and differentiation genetic programs expression. Interestingly, BRG1 and BAF47 are part of the SWI/SNF remodeling complex as well as the N-CoR-1 repressor complex in proliferating myoblasts. However, our data show that, upon myogenic differentiation, BAF47 shifts in favor of N-CoR-1 complex. Finally, BRG1 and BAF47 are well-known tumor suppressors but, strikingly, only BAF47 seems essential in the myoblasts irreversible cell cycle exit. Together, our data unravel differential roles for SWI/SNF subunits in muscle differentiation, with BAF47 playing a dual role both in the permanent cell cycle exit and in the regulation of muscle-specific genes.

Objectif Mesurer les effets de l’isolation sociale, de la sous-exposition a la lumiere et d’un travail poste specifique sur les rythmes de vigilance et de sommeil des sous-mariniers. Methodes Mesure a deux reprises au cours de la mission du sommeil par polysomnographie au jours j21 et j51 de la patrouille de 70 jours ainsi que des niveaux de cortisol urinaire apres le sommeil, et des mesures subjectives de somnolence (Karolinska), humeur et anxiete (POMS) les memes jours. Lieu : un sous-marin nucleaire lanceur d’engins en mission et isolation sociale complete (pas de telephone ou mail de la famille) dont la lumiere et la temperature sont controlees. Participants : 19 sous-mariniers travaillant en postes alternants reguliers sur 3 jours. Resultats L’analyse des polysomnographies montre que le temps de sommeil et sa composition (REM ou non REM) ne varie pas significativement au cours des deux mesures de j21 et j51. Les marins rapportent un sommeil subjectif similaire, et pas de variation significative de la somnolence, l’anxiete ou l’humeur (sauf pour score de confusion un peu degrade a j51). Les niveaux de cortisolemie ne sont pas modifies significativement. Conclusion Ces resultats montrent que des personnes vivant dans un isolement complet pendant plus de deux mois peuvent maintenir leurs rythmes de sommeil et de vigilance au cours d’un rythme regulier de travail poste et une lumiere et temperature controlees.

G9a/GLP and Polycomb Repressive Complex 2 (PRC2) are two major epigenetic silencing machineries, which in particular methylate histone H3 on lysines 9 and 27 (H3K9 and H3K27), respectively. Although evidence of a crosstalk between H3K9 and H3K27 methylations has started to emerge, their actual interplay remains elusive. Here, we show that PRC2 and G9a/GLP interact physically and functionally. Moreover, combining different genome-wide approaches, we demonstrate that Ezh2 and G9a/GLP share an important number of common genomic targets, encoding developmental and neuronal regulators. Furthermore, we show that G9a enzymatic activity modulates PRC2 genomic recruitment to a subset of its target genes. Taken together, our findings demonstrate an unanticipated interplay between two main histone lysine methylation mechanisms, which cooperate to maintain silencing of a subset of developmental genes.

International audience; Symmetrical dimethylation on arginine-3 of histone H4 (H4R3me2s) has been reported to occur at several repressed genes, but its specific regulation and genomic distribution remained unclear. Here, we show that the type-II protein arginine methyltransferase PRMT5 controls H4R3me2s in mouse embryonic fibroblasts (MEFs). In these differentiated cells, we find that the genome-wide pattern of H4R3me2s is highly similar to that in embryonic stem cells. In both the cell types, H4R3me2s peaks are detected predominantly at G + C-rich regions. Promoters are consistently marked by H4R3me2s, independently of transcriptional activity. Remarkably, H4R3me2s is mono-allelic at imprinting control regions (ICRs), at which it marks the same parental allele as H3K9me3, H4K20me3 and DNA methylation. These repressive chromatin modifications are regulated independently, however, since PRMT5-depletion in MEFs resulted in loss of H4R3me2s, without affecting H3K9me3, H4K20me3 or DNA methylation. Conversely, depletion of ESET (KMT1E) or SUV420H1/H2 (KMT5B/C) affected H3K9me3 and H4K20me3, respectively, without altering H4R3me2s at ICRs. Combined, our data indicate that PRMT5-mediated H4R3me2s uniquely marks the mammalian genome, mostly at G + C-rich regions, and independently from transcriptional activity or chromatin repression. Furthermore, comparative bioinformatics analyses suggest a putative role of PRMT5-mediated H4R3me2s in chromatin configuration in the nucleus.

The histone 3 lysine 9 methyltransferase Setdb1 is essential for both stem cell pluripotency and terminal differentiation of different cell types. To shed light on the roles of Setdb1 in these mutually exclusive processes, we used mouse skeletal myoblasts as a model of terminal differentiation. Ex vivo studies on isolated single myofibres showed that Setdb1 is required for adult muscle stem cells expansion following activation. In vitro studies in skeletal myoblasts confirmed that Setdb1 suppresses terminal differentiation. Genomic binding analyses showed a release of Setdb1 from selected target genes upon myoblast terminal differentiation, concomitant to a nuclear export of Setdb1 to the cytoplasm. Both genomic release and cytoplasmic Setdb1 relocalisation during differentiation were dependent on canonical Wnt signalling. Transcriptomic assays in myoblasts unravelled a significant overlap between Setdb1 and Wnt3a regulated genetic programmes. Together, our findings revealed Wnt-dependent subcellular relocalisation of Setdb1 as a novel mechanism regulating Setdb1 functions and myogenesis.

The H19 gene controls the expression of several genes within the Imprinted Gene Network (IGN), involved in growth control of the embryo. However, the underlying mechanisms of this control remain elusive. Here, we identified the methyl-CpG-binding domain protein 1 MBD1 as a physical and functional partner of the H19 long noncoding RNA (lncRNA). The H19 lncRNA-MBD1 complex is required for the control of five genes of the IGN. For three of these genes--Igf2 (insulin-like growth factor 2), Slc38a4 (solute carrier family 38 member 4), and Peg1 (paternally expressed gene 1)--both MBD1 and H3K9me3 binding were detected on their differentially methylated regions. The H19 lncRNA-MBD1 complex, through its interaction with histone lysine methyltransferases, therefore acts by bringing repressive histone marks on the differentially methylated regions of these three direct targets of the H19 gene. Our data suggest that, besides the differential DNA methylation found on the differentially methylated regions of imprinted genes, an additional fine tuning of the expressed allele is achieved by a modulation of the H3K9me3 marks, mediated by the association of the H19 lncRNA with chromatin-modifying complexes, such as MBD1. This results in a precise control of the level of expression of growth factors in the embryo.

Proctologic emergency are very common and are a true challenge for a general practitioner (GP) in a sea-based environment. Performing simple surgical procedures could be essential for the management of these patients. Thrombosed external hemorrhoids are very painful and necessitate the extraction of the blood clot under local anesthesia. The perianal abscess and the pilonidal abscess are also painful entities and represent a significant septic risk. The surgical management of the latter two is simple but requires general anesthesia. Using ketamine and midazolam with these procedures offers a very high level of anesthetic safety. This short article describes the mentioned procedures that are richly illustrated.

Introduction La securite des sous marins en mission intercontinentale depend de hautes technologies, mais aussi de facteurs humains incluant les rythmes veille-sommeil des equipages qui sont exposes a de longues periodes de travil poste et de nuit et a une isolation prolongee (70 jours) du monde reel (avec pas d’acces telephonique ou par Internet avec la famille ou les amis). Dans le but de mesurer ces rythmes veille-sommeil, nous avons realise l’enregistrement a bord du sommeil dans un groupe de 19 sous-mariniers volontaires en mission, travaillant sur un rythme de 3 × 24 heures au cours d’une mission de routine d’un sous marin nucleaire lanceur d’engin (SNLE). Methode Enregistrements polysomnographiques (PSG) a j21 et j51, mesure de cortisolemie apres le sommeil, et mesure subjective du sommeil, de la somnolence, de l’humeur et de l’anxiete (POMS) au cours des memes j21 et j51. La lumiere et la temperature a bord ont ete aussi mesures. Resultats L’analyse des PSG montre que le sommeil ne varie pas en longueur (Temps de sommeil total) ou en qualite durant la mission. Les marins rapportent subjectivement un sommeil, une somnolence, une humeur et une anxiete non significativement differente a J51 qu’a J21. Le score de confusion est plus eleve a J51. Les niveaux de cortisolemie ne varient pas significativement. Conclusion Ces resultats montrent que des hommes vivant dans un environnement isole pour plus de deux mois peuvent presenter des rythmes veille-sommeil maintenus lorsqu’ils suivent un rythme de travail regulier, sans contact avec l’exterieur et avec lumiere et temperature controlees.

Plants are an invaluable source of potential new anti-cancer drugs. Here, we investigated the cytotoxic activity of the acetonic extract of Buxus sempervirens on five breast cancer cell lines, MCF7, MCF10CA1a and T47D, three aggressive triple positive breast cancer cell lines, and BT-20 and MDA-MB-435, which are triple negative breast cancer cell lines. As a control, MCF10A, a spontaneously immortalized but non-tumoral cell line has been used. The acetonic extract of Buxus sempervirens showed cytotoxic activity towards all the five studied breast cancer cell lines with an IC(50) ranging from 7.74 µg/ml to 12.5 µg/ml. Most importantly, the plant extract was less toxic towards MCF10A with an IC(50) of 19.24 µg/ml. Fluorescence-activated cell sorting (FACS) analysis showed that the plant extract induced cell death and cell cycle arrest in G0/G1 phase in MCF7, T47D, MCF10CA1a and BT-20 cell lines, concomitant to cyclin D1 downregulation. Application of MCF7 and MCF10CA1a respective IC(50) did not show such effects on the control cell line MCF10A. Propidium iodide/Annexin V double staining revealed a pre-apoptotic cell population with extract-treated MCF10CA1a, T47D and BT-20 cells. Transmission electron microscopy analyses indicated the occurrence of autophagy in MCF7 and MCF10CA1a cell lines. Immunofluorescence and Western blot assays confirmed the processing of microtubule-associated protein LC3 in the treated cancer cells. Moreover, we have demonstrated the upregulation of Beclin-1 in these cell lines and downregulation of Survivin and p21. Also, Caspase-3 detection in treated BT-20 and T47D confirmed the occurrence of apoptosis in these cells. Our findings indicate that Buxus sempervirens extract exhibit promising anti-cancer activity by triggering both autophagic cell death and apoptosis, suggesting that this plant may contain potential anti-cancer agents for single or combinatory cancer therapy against breast cancer.

Background To assess the effects of isolation, inadequate exposure to light and specific shift work on the subjective and objective measurements of sleep and alertness of submariners. Purpose A strictly controlled randomized crossover study with the polysomnography recorded twice during the mission. Methods Setting: Shift and night work with prolonged (70 days) social isolation from the real world (with no phone or Internet contact with families or friends during a routine mission aboard the “Téméraire” French Strategic Submarine with Ballistic Nuclear missiles (SSBN). Participants: 19 submariners working on a 24-hour shift for three days in a row schedule. Interventions: The participants attended two polysomnographic (PSG) recordings of night sleep on Day 21 (D21) and Day 51 (D51) of the 70-day patrol; urine cortisol levels were also taken after sleep, and subjective assessments of sleep, sleepiness, mood and anxiety on D21 and D51. The light and temperature on board were also recorded. Results PSG analyses showed that sleep did not significantly vary in length (total sleep time) or in quality between D21 and D51. The mariners reported the same subjective sleep, sleepiness, anxiety or mood (except for a slightly worse score for confusion on D51). Blood cortisol levels did not vary significantly. Conclusions These results show that humans living in an isolated environment for more than two months with this specific shift schedule do not suffer from any significant effects on sleep, sleepiness and confusion between D21 and D51, when they follow an organized regular shift pattern with controlled light and temperature.

BCR-ABL has been shown to lead to a genetic instability in leukemic cells either directly by inducing oxidative stress or indirectly by compromising DNA repair mechanisms. BRCA1 is a major DNA repair gene as it promotes homologous recombination and plays thereby a critical role for preserving genomic integrity. We have previously reported that BCR-ABL down-regulates BRCA1 protein using a post-transcriptional mechanism (Deutsch et al, Blood 2003). The precise mechanism of this down regulation had not been established so far. BAP1 (BRCA1 associated protein-1) is a tumor suppressor gene that encodes a nuclear ubiquitin carboxy-terminal hydrolase, which interacts with BRCA1 protein and with many other cell cycle regulators. BAP1 is mutated in hereditary cancers and the overexpression of a deleted form of BAP1 has been shown to lead to a myelodysplastic syndrome in mice (Dey et al, Science 2012). In a gene profiling analysis of the human UT7 cells expressing BCR-ABL, we have discovered that the expression of BAP-1 is down-regulated as compared to parental UT7 cells. Using qRT-PCR and Western blotting analyses, we have confirmed the reduction of BAP1 transcript and protein levels in UT7 cells expressing BCR-ABL. This occurs in a tyrosine kinase dependent manner as exposure to Imatinib reverted BCR-ABL-associated BAP1 down-regulation. To determine the effects of BAP1 complementation in leukemic cells, we have transfected UT7-BCR-ABL cells with a BAP1 expression vector. The enforced expression of BAP1 in BCR-ABL expressing cells restored BRCA1 protein levels without affecting its mRNA level. As BAP1 is a deubiquitinase, we wondered whether there was an increased ubiquitination of BRCA1 in BCR-ABL expressing cells, due to a BAP1 deficiency. In the UT7-BCR-ABL model, we have performed immunoprecipitation of BRCA1 followed by Western blotting using anti-ubiquitin antibodies. These experiments revealed that BRCA1 was highly ubiquitinylated in BCR-ABL-expressing cells as compared to parental UT7 cells, explaining potentially its down-regulation in CML at the protein level via a proteasome-related mechanism. We next wished to validate these findings in primary human CML samples using qRT-PCR. In a cohort of newly diagnosed chronic phase CML patients before any therapy (n= 21) blood mRNA levels of BAP1 were significantly reduced ( p=0.0032, Mann Whitney Test ) as compared to normal controls (n= 8). Thus, our report reveals for the first time loss of BAP1 expression as a mechanism of the down-regulation of the DNA repair protein BRCA1 in CML. In addition to its contribution to genetic instability, BAP1 could be directly involved in the pathophysiology of CML due to its interactions with epigenetic factors such as polycomb proteins. The molecular mechanisms of BAP1 downregulation in BCR-ABL-expressing leukemic cells is under investigation. Disclosures: Guilhot: Novartis, BMS, Ariad, Pfizer: Honoraria. Turhan:BMS, Novartis: Honoraria, Research Funding.

Young transposable elements and their protein controllers team up to regulate the differentiation and function of human neurons., In the first days of embryogenesis, transposable element–embedded regulatory sequences (TEeRS) are silenced by Kruppel-associated box (KRAB) zinc finger proteins (KZFPs). Many TEeRS are subsequently co-opted in transcription networks, but how KZFPs influence this process is largely unknown. We identify ZNF417 and ZNF587 as primate-specific KZFPs repressing HERVK (human endogenous retrovirus K) and SVA (SINE-VNTR-Alu) integrants in human embryonic stem cells (ESCs). Expressed in specific regions of the human developing and adult brain, ZNF417/587 keep controlling TEeRS in ESC-derived neurons and brain organoids, secondarily influencing the differentiation and neurotransmission profile of neurons and preventing the induction of neurotoxic retroviral proteins and an interferon-like response. Thus, evolutionarily recent KZFPs and their TE targets partner up to influence human neuronal differentiation and physiology.

The human genome harbors more than 4.5 million transposable element (TE)-derived insertions, the result of recurrent waves of invasion and internal propagation. Here they show that TEs belonging to evolutionarily recent subfamilies go on to regulate later stages of human embryonic development, notably conditioning the expression of genes involved in gastrulation and early organogenesis., The human genome contains more than 4.5 million inserts derived from transposable elements (TEs), the result of recurrent waves of invasion and internal propagation throughout evolution. For new TE copies to be inherited, they must become integrated in the genome of the germline or pre-implantation embryo, which requires that their source TE be expressed at these stages. Accordingly, many TEs harbor DNA binding sites for the pluripotency factors OCT4, NANOG, SOX2, and KLFs and are transiently expressed during embryonic genome activation. Here, we describe how many primate-restricted TEs have additional binding sites for lineage-specific transcription factors driving their expression during human gastrulation and later steps of fetal development. These TE integrants serve as lineage-specific enhancers fostering the transcription, amongst other targets, of KRAB-zinc finger proteins (KZFPs) of comparable evolutionary age, which in turn corral the activity of TE-embedded regulatory sequences in a similarly lineage-restricted fashion. Thus, TEs and their KZFP controllers play broad roles in shaping transcriptional networks during early human development.

Expansion of transposable elements (TEs) coincides with evolutionary shifts in gene expression. TEs frequently harbor binding sites for transcriptional regulators, thus enabling coordinated genome-wide activation of species- and context-specific gene expression programs, but such regulation must be balanced against their genotoxic potential. Here, we show that Krüppel-associated box (KRAB)-containing zinc finger proteins (KZFPs) control the timely and pleiotropic activation of TE-derived transcriptional cis regulators during early embryogenesis. Evolutionarily recent SVA, HERVK, and HERVH TE subgroups contribute significantly to chromatin opening during human embryonic genome activation and are KLF-stimulated enhancers in naive human embryonic stem cells (hESCs). KZFPs of corresponding evolutionary ages are simultaneously induced and repress the transcriptional activity of these TEs. Finally, the same KZFP-controlled TE-based enhancers later serve as developmental and tissue-specific enhancers. Thus, by controlling the transcriptional impact of TEs during embryogenesis, KZFPs facilitate their genome-wide incorporation into transcriptional networks, thereby contributing to human genome regulation. Transposable elements (TEs) are key to the evolutionary turnover of regulatory sequences but potentially toxic to the host. Trono and colleagues demonstrate that KRAB zinc-finger proteins tame the activity of TEs during human early embryogenesis, thus allowing for their genome-wide incorporation into species-specific transcriptional networks., National Institutes of Health (Grant R37HD045022), National Institutes of Health (Grant R01-NS088538)

Germ cells are essential to pass DNA from one generation to the next. In human reproduction, germ cell development begins with the specification of primordial germ cells (PGCs) and a failure to specify PGCs leads to human infertility. Recent studies have revealed that the transcription factor network required for PGC specification has diverged in mammals, and this has a significant impact on our understanding of human reproduction. Here, we reveal that the Hominidae-specific Transposable Elements (TEs) LTR5Hs, may serve as TEENhancers (TE Embedded eNhancers) to facilitate PGC specification. LTR5Hs TEENhancers become transcriptionally active during PGC specification both in vivo and in vitro with epigenetic reprogramming leading to increased chromatin accessibility, localized DNA demethylation, enrichment of H3K27ac, and occupation of key hPGC transcription factors. Inactivation of LTR5Hs TEENhancers with KRAB mediated CRISPRi has a significant impact on germ cell specification. In summary, our data reveals the essential role of Hominidae-specific LTR5Hs TEENhancers in human germ cell development., The transcription factor network required for primordial germ cell (PGC) specification is known to diverge in mammals. Here the authors show that hominidae-specific transposable element (TE) LTR5Hs becomes transcriptionally active during PGC specification, and LTR5Hs inactivation abrogates human PGC specification

According to the literature, 8% of the population claim to have an allergy to penicillin. Allergy tests show that 90% of these patients tolerate this molecule. Physicians working in the French Navy are faced with situations of real isolation and only have a limited number of antibiotics on board, the majority of which are penicillins. They must anticipate the risks linked to the prescription of antibiotics prior to the mission. However, there is no French recommendation, either military or civilian, intended for general practitioners clarifying the management and allergy assessments of patients alleging a history of allergy to penicillin. This study is the first to evaluate the professional practices of French military practitioners taking care of these patients. The main objective was to evaluate the proportion of sailors who reported an allergy to penicillin and who have never been referred for a consultation with an allergist, by studying the medical files of all the submariners working on the submersible ballistic nuclear submarines (SSBN) squadron in Brest. The secondary objective was to compare these data with the practices of Navy doctors by means of questionnaires. Material and methods : Exhaustive monocentric study of the digital and paper medical files of Brest submariners (n=814) looking for allergist consultation reports in cases alleging an allergy to penicillin, then comparaison with a multicentric collection of all Navy doctors' practices collected by an anonymised questionnaire (n=37 out of 53 practising at the time of the study). Results : Forty-seven subjects out of 814 alleged an allergy to penicillin (5.8%). Among them, only 12 (25.5%) had undergone allergy tests, of which 3 (6.4%) were confirmed to be allergic, with no cross- reaction between B-Lactam antibiotics. Yet, according to the questionnaire, 25 doctors (67%) report referring their patients to an allergist and 16 (43%) report having had difficulties at sea in connection with the prescription of antibiotics for these patients. Conclusions: A study of medical records shows that the allergic risk is not anticipated for 74.5% of patients labelled allergic, despite the difficulties encountered at sea. Standardisation of practices within the French Navy is necessary to avoid the prescription of second-line antibiotics, less effective and sometimes unavailable on board, and to improve patient safety in isolation situations. In agreement with French military allergists, we propose, in this article, guidelines for a systematic exploration of allegations of allergy to Penicillin in the French Navy.; Selon la littérature, 8% de la population déclarent avoir une allergie à la Pénicilline. Les tests allergologiques montrent que 90% de ces patients tolèrent en réalité la molécule. Les médecins exerçant au sein de la Marine Nationale sont confrontés à des situations de réel isolement et ne disposent que d’un nombre limité d’antibiotiques à bord. Les risques liés à la prescription des antibiotiques doivent être anticipés par le médecin en amont de la mission. L’objectif principal était d’évaluer la proportion de marins ayant déclaré une allergie à la Pénicilline et n’ayant jamais bénéficié d’un bilan allergologique. Quarante-sept sujets sur 814 allèguent une allergie à la Pénicilline (4.7%). Parmi ces cas, seulement 12 (25.5%) ont bénéficié d’un bilan allergologique, dont 3 (6.4%) sont confirmés allergiques, sans réaction croisée entre B-Lactamines. D’après le questionnaire, 36 médecins (97%) déclarent adresser leurs patients chez l’allergologue et 16 (43%) rapportent avoir eu des difficultés en mer en lien avec la prescription d’antibiotique pour ces patients. L’étude des dossiers médicaux montre que le risque allergique n’est pas anticipé pour 74.5% des patients étiquetés allergiques, malgré les difficultés rencontrées en mer. Une harmonisation des pratiques s’impose au sein de la Marine Nationale pour éviter la prescription d’un antibiotique de 2e intention et garantir la sécurité du patient en situation d’isolement. En accord avec les allergologues militaires français, nous formulons des recommandations pour une exploration systématique des allégations d’allergie à la Pénicilline.

Thèse présentée sous la forme d'une "Thèse Article"; Introduction : le sous-marin nucléaire en mission représente un milieu singulier, exposant ses occupants à des contraintes type ICE (isolated and confined environment) et EUE (extreme and unusual environment) pendant une période pouvant varier entre 60 et 90 jours. Les diverses études réalisées sur une population de sous-mariniers ont pu mettre en évidence une altération de la thymie et du bien-être au cours de la mission. De nombreux bienfaits d’une activité physique sur la santé mentale sont décrits dans la littérature. Ce travail de thèse a donc pour objectif de déterminer l’impact d’une activité physique sur la thymie du sous-marinier en cours de mission ; l’impact de la pratique du sport sera évalué sur le maintien de l’intéroception et de l’extéroception en objectif secondaire.Méthode : il s’agit d’une étude exploratoire pragmatique de suivi de cohorte. L’étude a été menée sur 29 sujets sous-mariniers volontaires de l’équipage rouge du Triomphant (SNLE). La pratique sportive a été évaluée par un auto-questionnaire quotidien permettant de classer les sous-mariniers en deux groupes (sportifs réguliers et non-sportifs). Des auto-questionnaires validés en français ont été complétés au début, pendant, et en fin de patrouille afin de comparer l’évolution de la thymie, de la santé et de l’intéroception entre les deux groupes. L‘extéroception visuelle (accommodation) et proprioceptive (stabilométrie) ont été étudiées au décours la patrouille par des tests objectifs, et comparées entre les deux groupes.Résultats : la thymie et la santé se dégradent globalement au cours de la patrouille. Concernant la thymie, il existe, pour les sportifs, une stabilité du niveau d’activation, contrairement aux non-sportifs. Il n’existe pas d’effet du sport sur les variations d’émotion positives/négatives. Leur sensorialité semble davantage préservée en ce qui concerne la proprioception et l’accommodation visuelle éloignée. Leur qualité d’intéroception n’est pas supérieure à celle des non-sportifs.Conclusion : l’activité physique pendant la patrouille seule n’est pas suffisante pour pallier les dysrégulations thymiques induites par le milieu du SNLE. Néanmoins elle semble intéressante pour maintenir une bonne sensorialité. Cette étude exploratoire ouvre des pistes pour d’éventuelles futures recherches sur une activité physique associée à une stimulation sensorielle chez les sous-mariniers et, de manière plus générale, sur le rôle de l’intéroception en milieu ICE et EUE.

Thèse présentée sous la forme d'une "Thèse Article"; Contexte : les sous-mariniers évoluent au cours de leurs missions dans un environnement isolé et confiné (ICE), privés de lumière naturelle et soumis aux rythmes de quart. Les troubles de la vigilance induits peuvent conduire à une erreur de procédure, souvent fatale à plusieurs centaines de mètres de profondeur. L’objectif principal de cette étude était d’évaluer l’utilisation de la sieste comme contre-mesure à la fatigue adaptée aux missions de sous-marins. L’autre objectif était de mesurer en continu la détérioration de la vigilance et le degré de fatigue chez les sous-mariniers en patrouille opérationnelle. Méthodes : 34 sous-mariniers en bonne santé avec une moyenne d’âge de 28,7 ans ont été suivis pendant les 8 semaines d’une patrouille d’un sous-marin nucléaire lanceur d’engins (SNLE), sans semaine de repos ou remontée à la surface. Leur rythme veille-sommeil et les siestes ont été enregistrés en continu par actimétrie (24h/24) et par agenda de sommeil et d’activités. Leur état de fatigue, somnolence et performances cognitives ont été mesurés cinq fois au cours de la patrouille au moyen du questionnaire d’Epworth (ESS), du score de Pichot, et du Psychomotor Vigilance Test (PVT). Résultats : Le sommeil des sous-mariniers était court avec un Temps de Sommeil Total (TST) moyen de 6h, et de mauvaise qualité, comme en témoignent les valeurs pathologiques de l’index d’efficacité du sommeil (SEI 45 minutes). La fatigue ressentie devenait significative autour de J50 alors que le degré de somnolence restait stable (Pichot > 19 et ESS moyen < 4). Les performances cognitives, évaluées par le PVT, étaient significativement dégradées lorsque le temps passé au lit (TIB) précédant le test était inférieur à 6h. Malgré cette fatigue, les sous-mariniers faisaient très peu la sieste (moins de deux par semaine) mais allongeaient progressivement leur TST au cours de la mission.Conclusions : les sous-mariniers ont un sommeil trop court et non récupérateur. Ils compensent en allongeant progressivement mais insuffisamment leur TST. Le rythme de quart « français » avec des quarts courts semble protéger de la somnolence. En revanche, notre travail démontre que les sous-mariniers sont de plus en plus fatigués au cours de leur mission et que leurs performances diminuent lorsqu’ils dorment moins de 6h, durée de leur TST moyen. La navigation sous-marine est dangereuse et exige des réactions parfaites en cas de crise. La gestion de la fatigue doit être une priorité. La sieste, peu utilisée par l’équipage, est pourtant une contre-mesure bien connue et efficace. Elle devrait être encouragée.

Thèse présentée sous la forme d'une "Thèse Article"; Introduction: The empirical finding of obstructive lung disease (OLD) in young submariners in a context of worsening morbidity and mortality of occupational chronic obstructive pulmonary disease (COPD) led us to question the impact of the professional exposure of this special working environment.Material and methods: We conducted a retrospective, mono-centric, epidemiological and analytical study. The studied population accounted 277 submariners, divided into 3 seniority groups of 5, 10 and 15 years. The main objective was to measure the prevalence of OLD in the population. Secondary objectives were to compare the decline in forced expiratory volume in 1 second (FEV1) of our population with the expected charts results and to investigate (by a logistic regression analysis) the impact of different factors for the prevalence of TVO and for the early decline in FEV1.Results: All seniority combined, the prevalence of OLD in the course of career was 9%, 52% of them had an isolated impairment of distal flow. Only 7 subjects (2.5% of our sample) had an obstruction defined by FEV 1 / FVC

Objectif : Evaluer l’impact opérationnel des petites urgences chirurgicales à bord des navires de surface français en calculant la prévalence de ces urgences au sein de l’ensemble des évacuations médicales (MEDEVAC). Déterminer si des MEDEVAC urgentes (< 24 heures) auraient pu être évitées et quelles étaient les principales urgences représentées. Méthode : Etude descriptive rétrospective de l’ensemble des dossiers de MEDEVAC de la Force d’Action Navale entre 2009 et 2014. Résultats : Sur les 560 MEDEVAC pratiquées sur les bâtiments de surface français, 34 (6,1%) furent pour des marins atteints d’une petite urgence chirurgicale prise en charge par un médecin de marine en situation isolée. Parmi eux, 27 ont bénéficié d’une MEDEVAC non urgente et la moitié n’a pas eu de geste tenté à bord. Seuls 7 patients ont imposé une évacuation urgente et parmi eux, 5 patients n’ont pas bénéficié du geste thérapeutique indiqué. La fracture du 5ème métacarpien déplacée était la pathologie la plus représentée. Conclusion : Contrairement à notre idée de départ, l’impact opérationnel des petites urgences chirurgicales reste faible. Toutefois, 17 des patients évacués n’ont pas bénéficié du geste simple indiqué. L’idée qu’une formation pratique spécifique à ces gestes soit institutionnalisée reste donc pertinente.