Early Miocene stalked crinoids (Echinodermata) from the southern Rhodanian basin (southeastern France). Paleoenvironments and taxonomy.

Using recent samplings and specimens from ancient collections, 14 sites and five species of stalked crinoids have been listed in the Miocene of the southern Rhodanian basin (southeastern France). Three species and two genera are new for science: Papacrinus avignonensis n. gen., n sp. (Balanocrininae), Paraconocrinus rhodanicus n. sp. (Rhizocrinidae) and Gastecrinus vinealis n. gen., n. sp. (Incertae sedis). The identification among the Mediterranean Miocene fauna of the genus Metacrinus, now confined to the Indo-Pacific province, was confirmed by the discovery of brachial ossicles attributed to Metacrinus berthei. The richest and most diversified site was exposed during temporal excavations at the Place du Palais des Papes in Avignon. Four out of the five stalked crinoid species were found in this fossil assemblage in which M. berthei predominates. ?Endoxocrinus gastaldii is associated with M. berthei in several sites. Using dissociated ossicles, differences in quantitative and qualitative characters between these two species are deeply analyzed with their taphonomical, taxonomical and paleoecological consequences. Paleoreliefs and valleys, which had been incised during the Burdigalian, channeled currents. They favored stalked crinoid settlement on various substrates during the late BurdigalianLower Langhian transgression. Comparison with the extant fauna allows us to estimate the depth range of the biotopes with stalked crinoids from 100 to 250 m. These estimates are in agreement with those deduced from other paleontological studies.

The association between time incarcerated and the search for employment in a veteran sample with substance use disorders.

OBJECTIVE: Incarceration and substance use disorders/mental illness can have a significant negative impact on finding employment. However, it is unclear in what phase of the search for employment, that is, applying for jobs, obtaining interviews, being offered employment, does time incarcerated have the most effect. This study will determine how time incarcerated in the past 10 years is associated with negative job search process outcomes. METHOD: This study evaluates 84 (81 men and 3 women) veterans with substance use disorders and histories of felony convictions. Four path analyses were conducted to evaluate models that incorporated time incarcerated at the different phases. RESULTS: The superior model incorporated time incarcerated negatively affecting the number of interviews obtained. Models that assessed the association between time incarcerated with applications submitted and likelihood of being offered employment did not demonstrate adequate goodness-of-fit. CONCLUSION AND IMPLICATIONS FOR PRACTICE: Overall, the findings demonstrate the ex-offenders enrolled exhibited similar effort in searching for employment across time incarcerated. Also, employers are equally likely to hire those with felony histories, regardless of the time incarcerated, once the applicant has been met and interviewed. The results highlight the need for services focusing on breaking down stigma and reducing barriers that screen out ex-offenders from being interviewed by employers. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Genome data on the extinct Bison schoetensacki establish it as a sister species of the extant European bison (Bison bonasus).

BACKGROUND: The European bison (Bison bonasus), now found in Europe and the Caucasus, has been proposed to originate either from the extinct steppe/extant American bison lineage or from the extinct Bison schoetensacki lineage. Bison schoetensacki remains are documented in Eurasian Middle Pleistocene sites, but their presence in Upper Pleistocene sites has been questioned. Despite extensive genetic studies carried out on the steppe and European bison, no remains from the fossil record morphologically identified as Bison schoetensacki has been analyzed up to now. RESULTS: In this paper, we analyzed a 36,000-year-old Bison schoetensaki bone sample from the Siréjol cave (France) and a cave hyena coprolite (fossilized feces) found in a nearby cave and containing large amounts of Bovinae DNA. We show that the Bovinae mitochondrial DNA sequences from both samples, including a complete mitochondrial genome sequence, belong to a clade recently reported in the literature. This clade only includes ancient bison specimens without taxonomic identification and displays a sister relationship with the extant European bison. The genetic proximity of Bison schoetensacki with specimens from this clade is corroborated by the analysis of nuclear DNA single nucleotide polymorphisms. CONCLUSIONS: This work provides genetic evidence supporting the continuing presence of Bison schoetensacki up to the Upper Pleistocene. Bison schoetensacki turns out to be a sister species of Bison bonasus, excluding the steppe bison Bison priscus as a direct ancestor of the European bison.

A high-precision chronological model for the decorated Upper Paleolithic cave of Chauvet-Pont d'Arc, Ardèche, France.

Radiocarbon dates for the ancient drawings in the Chauvet-Pont d'Arc Cave revealed ages much older than expected. These early ages and nature of this Paleolithic art make this United Nations Educational, Scientific and Cultural Organization (UNESCO) site indisputably unique. A large, multidisciplinary dating program has recently mapped the anthropological evolution associated with the cave. More than 350 dates (by (14)C, U-Th, TL and (36)Cl) were obtained over the last 15 y. They include 259 radiocarbon dates, mainly related to the rock art and human activity in the cave. We present here more than 80 previously unpublished dates. All of the dates were integrated into a high-precision Bayesian model based on archaeological evidence to securely reconstruct the complete history of the Chauvet-Pont d'Arc Cave on an absolute timescale. It shows that there were two distinct periods of human activity in the cave, one from 37 to 33,500 y ago, and the other from 31 to 28,000 y ago. Cave bears also took refuge in the cave until 33,000 y ago.

A chimerical phagocytosis model reveals the recruitment by Sertoli cells of autophagy for the degradation of ingested illegitimate substrates.

Phagocytosis and autophagy are typically dedicated to degradation of substrates of extrinsic and intrinsic origins respectively. Although overlaps between phagocytosis and autophagy were reported, the use of autophagy for ingested substrate degradation by nonprofessional phagocytes has not been described. Blood-separated tissues use their tissue-specific nonprofessional phagocytes for homeostatic phagocytosis. In the testis, Sertoli cells phagocytose spermatid residual bodies produced during germ cell differentiation. In the retina, pigmented epithelium phagocytoses shed photoreceptor tips produced during photoreceptor renewal. Spermatid residual bodies and shed photoreceptor tips are phosphatidylserine-exposing substrates. Activation of the tyrosine kinase receptor MERTK, which is implicated in phagocytosis of phosphatidylserine-exposing substrates, is a common feature of Sertoli and retinal pigmented epithelial cell phagocytosis. The major aim of our study was to investigate to what extent phagocytosis by Sertoli cells may be tissue specific. We analyzed in Sertoli cell cultures that were exposed to either spermatid residual bodies (legitimate substrates) or retina photoreceptor outer segments (illegitimate substrates) the course of the main phagocytosis stages. We show that whereas substrate binding and ingestion stages occur similarly for legitimate or illegitimate substrates, the degradation of illegitimate but not of legitimate substrates triggers autophagy as evidenced by the formation of double-membrane wrapping, MAP1LC3A-II/LC3-II clustering, SQSTM1/p62 degradation, and by marked changes in ATG5, ATG9 and BECN1/Beclin 1 protein expression profiles. The recruitment by nonprofessional phagocytes of autophagy for the degradation of ingested cell-derived substrates is a novel feature that may be of major importance for fundamentals of both apoptotic substrate clearance and tissue homeostasis.

The vitamin K-dependent anticoagulant factor, protein S, inhibits multiple VEGF-A-induced angiogenesis events in a Mer- and SHP2-dependent manner.

Protein S is a vitamin K-dependent glycoprotein, which, besides its anticoagulant function, acts as an agonist for the tyrosine kinase receptors Tyro3, Axl, and Mer. The endothelium expresses Tyro3, Axl, and Mer and produces protein S. The interaction of protein S with endothelial cells and particularly its effects on angiogenesis have not yet been analyzed. Here we show that human protein S, at circulating concentrations, inhibited vascular endothelial growth factor (VEGF) receptor 2-dependent vascularization of Matrigel plugs in vivo and the capacity of endothelial cells to form capillary-like networks in vitro as well as VEGF-A-induced endothelial migration and proliferation. Furthermore, protein S inhibited VEGF-A-induced endothelial VEGFR2 phosphorylation and activation of mitogen-activated kinase-Erk1/2 and Akt. Protein S activated the tyrosine phosphatase SHP2, and the SHP2 inhibitor NSC 87877 reversed the observed inhibition of VEGF-A-induced endothelial proliferation. Using siRNA directed against Tyro3, Axl, and Mer, we demonstrate that protein S-mediated SHP2 activation and inhibition of VEGF-A-stimulated proliferation were mediated by Mer. Our report provides the first evidence for the existence of a protein S/Mer/SHP2 axis, which inhibits VEGFR2 signaling, regulates endothelial function, and points to a role for protein S as an endogenous angiogenesis inhibitor.

An endogenous vitamin K-dependent mechanism regulates cell proliferation in the brain subventricular stem cell niche.

Neural stem cells (NSC) persist in the adult mammalian brain, within the subventricular zone (SVZ). The endogenous mechanisms underpinning SVZ stem and progenitor cell proliferation are not fully elucidated. Vitamin K-dependent proteins (VKDPs) are mainly secreted factors that were initially discovered as major regulators of blood coagulation. Warfarin ((S(-)-3-acetonylbenzyl)-4-hydroxycoumarin)), a widespread anticoagulant, is a vitamin K antagonist that inhibits the production of functional VKDP. We demonstrate that the suppression of functional VKDPs production, in vitro, by exposure of SVZ cell cultures to warfarin or, in vivo, by its intracerebroventricular injection to mice, leads to a substantial increase in SVZ cell proliferation. We identify the anticoagulant factors, protein S and its structural homolog Gas6, as the two only VKDPs produced by SVZ cells and describe the expression and activation pattern of their Tyro3, Axl, and Mer tyrosine kinase receptors. Both in vitro and in vivo loss of function studies consisting in either Gas6 gene invalidation or in endogenous protein S neutralization, provided evidence for an important novel regulatory role of these two VKDPs in the SVZ neurogenic niche. Specifically, we show that while a loss of Gas6 leads to a reduction in the numbers of stem-like cells and in olfactory bulb neurogenesis, endogenous protein S inhibits SVZ cell proliferation. Our study opens up new perspectives for investigating further the role of vitamin K, VKDPs, and anticoagulants in NSC biology in health and disease.

Deciphering the complete mitochondrial genome and phylogeny of the extinct cave bear in the Paleolithic painted cave of Chauvet.

Retrieving a large amount of genetic information from extinct species was demonstrated feasible, but complete mitochondrial genome sequences have only been deciphered for the moa, a bird that became extinct a few hundred years ago, and for Pleistocene species, such as the woolly mammoth and the mastodon, both of which could be studied from animals embedded in permafrost. To enlarge the diversity of mitochondrial genomes available for Pleistocene species, we turned to the cave bear (Ursus spelaeus), whose only remains consist of skeletal elements. We collected bone samples from the Paleolithic painted cave of Chauvet-Pont d'Arc (France), which displays the earliest known human drawings, and contains thousands of bear remains. We selected a cave bear sternebra, radiocarbon dated to 32,000 years before present, from which we generated overlapping DNA fragments assembling into a 16,810-base pair mitochondrial genome. Together with the first mitochondrial genome for the brown bear western lineage, this study provides a statistically secured molecular phylogeny assessing the cave bear as a sister taxon to the brown bear and polar bear clade, with a divergence inferred to 1.6 million years ago. With the first mitochondrial genome for a Pleistocene carnivore to be delivered, our study establishes the Chauvet-Pont d'Arc Cave as a new reservoir for Paleogenetic studies. These molecular data enable establishing the chronology of bear speciation, and provide a helpful resource to rescue for genetic analysis archeological samples initially diagnosed as devoid of amplifiable DNA.

Ancient DNA evidence for the loss of a highly divergent brown bear clade during historical times.

The genetic diversity of present-day brown bears (Ursus arctos) has been extensively studied over the years and appears to be geographically structured into five main clades. The question of the past diversity of the species has been recently addressed by ancient DNA studies that concluded to a relative genetic stability over the last 35,000 years. However, the post-last glacial maximum genetic diversity of the species still remains poorly documented, notably in the Old World. Here, we analyse Atlas brown bears, which became extinct during the Holocene period. A divergent brown bear mitochondrial DNA lineage not present in any of the previously studied modern or ancient bear samples was uncovered, suggesting that the diversity of U. arctos was larger in the past than it is now. Specifically, a significant portion (with respect to sequence divergence) of the intraspecific diversity of the brown bear was lost with the extinction of the Atlas brown bear after the Pleistocene/Holocene transition.

Neuroprotective effects of pituitary adenylate cyclase-activating polypeptide (PACAP) in MPP+-induced alteration of translational control in Neuro-2a neuroblastoma cells.

UNLABELLED: Parkinson's disease (PD) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity are both associated with dopaminergic neuron death in the substantia nigra. Although a variety of evidence has shown that degenerative cells have apoptotic features, the role of apoptosis in disease pathology remains controversial. The 1-methyl-4-phenylpyridinium ion (MPP(+)), a metabolite of MPTP, was recently shown to alter the expression of proteins involved in translational control. The initiation step of translational control is regulated by a cascade of phosphorylation affecting proteins of the antiapoptotic way controlled by mammalian target of rapamycin (mTOR) and of the proapoptotic way controlled by double-stranded RNA protein-dependent kinase (PKR). A study showed that MPP(+) induced an increase in eIF2alpha phosphorylation, leading to inhibition of protein synthesis. THE AIMS OF OUR STUDY WERE: (1) to assess the effects of MPP(+) toxicity on molecular factors of PKR and mTOR signaling pathways in murine neuroblastoma cells, and (2) to examine the ability of VIP and PACAP peptides to counteract the MPP(+) toxicity. Our findings showed that MPP(+) induced phosphorylation of eIF2alpha and significantly reduced the expression of phosphorylated mTOR, p70S6K, eIF4E, and 4E-BP1, suggesting its toxicity in controlling protein synthesis. Furthermore, the VIP peptide had no effect on either the PKR or the mTOR signaling pathway. On the contrary, the PACAP 27 neuropeptide prevented MPP(+)-induced eIF2alpha phosphorylation and blocked MPP(+) toxicity in molecular factors of the mTOR pathway. And last, PACAP 27 seemed to protect Neuro-2a cells from the apoptotic process as assessed by the decreased nuclear condensation after DAPI staining. These results could open new paths of research of PACAP in PD.

The VIP-receptor system in neuroblastoma cells.

Neuroblastoma (NB), the most common extracranial tumor during childhood arises from the embryonic sympathetic nervous system. Remarkably, NB can spontaneously regress, even after metastasis, leading to complete remission. Subpopulations of neuroblastic (N-type) and nonneuronal cells coexist in NB. Expression of the high-affinity nerve growth factor (NGF) TrkA receptor in NB is correlated with good prognosis, while MYCN amplification is associated with advanced stages of disease. N-type cells undergo differentiation when treated with different compounds, such as retinoids, phorbol esters, growth and neurotrophic NGF and neuropeptides, especially vasoactive intestinal peptide (VIP). These substances stabilize proliferation, leading to a more mature neuronal phenotype, neurite outgrowth and induction of expression of sympathetic neuronal markers. Therefore, receptors for these substances and their associated signalling pathways, appear like promising targets for the development of novel NB therapeutics. The aim of the present review is to summarize the quite considerable array of data, concerning production of VIP and related peptides, expression of their receptors in NB and the key regulation exerted by the VIP-receptor system in the control of NB cell behaviour.

Vasoactive intestinal peptide-induced neurite remodeling in human neuroblastoma SH-SY5Y cells implicates the Cdc42 GTPase and is independent of Ras-ERK pathway.

Vasoactive intestinal peptide (VIP) is known to regulate proliferation or differentiation in normal and tumoral cells. SH-SY5Y is a differentiated cell subclone derived from the SK-N-SH human neuroblastoma cell line and possess all the components for an autocrine action of VIP. In the present study, we investigated the morphological changes and intracellular signaling pathways occurring upon VIP treatment of SH-SY5Y cells. VIP induced an early remodeling of cell projections: a branched neurite network spread out and prominent varicosities developed along neurites. Although activated by VIP, the Ras/ERK pathway was not required for the remodeling process. In contrast, pull-down experiments revealed a strong Cdc42 activation by VIP while expression of a dominant-negative Cdc42 prevented the VIP-induced neurite changes, suggesting an important role for this small GTPase in the process. These data provide the first evidence for a regulation of the activity of Rho family GTPases by VIP and bring new insights in the signaling pathways implicated in neurite remodeling process induced by VIP in neuroblastoma cells.

One-step synthesis of beta-C-glycolipid derivatives from unprotected sugars.

Condensations of nonsymmetrical or symmetrical beta-diketones and unprotected sugars in aq NaHCO3 soln were explored. C-glucosyl and C-maltosyl derivatives bearing lipophilic residue of 8 or 11 carbon atoms were prepared efficiently using this one-step procedure. The amphiphilic properties of these compounds were demonstrated by measuring their CMC.

The protein kinase kin1 is required for cellular symmetry in fission yeast.

The fission yeast Schizosaccharomyces pombe is a highly polarized unicellular eukaryote with two opposite growing poles in which F-actin cytoskeleton is focused. The KIN1/PAR-1/MARK protein family is composed of conserved eukaryotic serine/threonine kinases which are involved in cell polarity, microtubule stability or cell cycle regulation. Here, we investigate the function of the fission yeast KIN1/PAR-1/MARK member, kin1p. Using a deletion allele (kin1Delta), we show that kin1 mutation promotes a delay in septation. Kin1p regulates the structure of the new cell end after cytokinesis by modulating cell wall remodeling. Abnormal shaped interphase kin1Delta cells misplace F-actin patches and the premitotic nucleus. Thus, mitotic kin1Delta cells misposition the F-actin ring assembly site that is dependent on the position of the interphase nucleus. The resulting asymmetric cell division produces daughter cells with distinct shapes. Overexpressed kin1p accumulates asymmetrically at the cell cortex and affects cell shape, F-actin organization and microtubules. Our results suggest that correct dosage of kin1p at the cortex is required for spatial organization of the fission yeast cell.

Looking for nuclear translation using xenopus oocytes.

In eukaryotes transcription and translation takes place in two different compartments separated by the nuclear envelope. Nuclear translation has been reported in several publications, however, all these published results have been criticized, particularly with respect to cytoplasmic contamination of the nuclei. We have investigated the question of nuclear protein synthesis using a different strategy. We microinjected frog oocytes with different DNA and RNA constructs and searched for translation products in nuclei separated from the cytoplasm by microdissection. We have been unable to detect any translation within the nuclei but rather a saturable translation in the perinuclear cytoplasm associated with the isolated nuclei.

Eukaryotic release factors (eRFs) history.

In the present review, we describe the history of the identification of the eukaryotic translation termination factors eRF1 and eRF3. As in the case of several proteins involved in general and essential processes in all cells (e.g., DNA replication, gene expression regulation.) the strategies and methodologies used to identify these release factors were first established in prokaryotes. The genetic investigations in Saccharomyces cerevisiae have made a major contribution in the field. A large amount of data have been produced, from which it was concluded that the SUP45 and SUP35 genes were controlling translation termination but were also involved in other functions important for the cell organization and the cell cycle accomplishment. This does not seem to be restricted to yeast but is also probably the case in eukaryotes in general. The biochemical studies of the proteins encoded by the higher eukaryote homologs of SUP45 and SUP35 were efficient and permitted the identification of eRF1 as being the key protein in the termination process, eRF3 having a stimulating role. Around 25 years were needed after the identification of sup45 and sup35 mutants for the characterization of their gene products as eRF1 and eRF3, respectively. It also has to be pointed out that if the results came first from bacteria, the identification of RF3 and eRF3 was made practically at the same time. Moreover, eRF1 was the first crystal structure obtained for a class-1 release factor, the bacterial RF2 structure came later. The goal is now to understand at the molecular level the roles of both eRF1 and eRF3 in addition to their translation termination functions.

Vasoactive intestinal peptide stimulates proliferation in HT29 human colonic adenocarcinoma cells: concomitant activation of Ras/Rap1-B-Raf-ERK signalling pathway.

The vasoactive intestinal peptide (VIP) has been shown to regulate cell proliferation and differentiation in many cell types. We previously reported that this neuropeptide inhibited proliferation in HT29 adenocarcinoma cells cultured in serum-containing medium. In addition, it has been demonstrated that VIP induced a potent stimulation of intracellular cAMP production in these cells cultured either in the absence or in the presence of serum. We also demonstrated that VIP induced phosphorylation of the small GTPase Rap1 in these cancerogenous cells. In the present study, the effects of VIP on the proliferation of HT29 cells cultured in the absence of growth factors and various concomitant signalling events were investigated. Under serum-free conditions VIP stimulates HT29 cell proliferation and induced a time- and concentration-dependent ERK activation. Furthermore, VIP induced the activation of the small GTPase Rap1 and of a 95 kDa isoform of the serine/threonine kinase B-Raf. Ras GTPase is also activated in VIP-stimulated cells. We hypothesize that VIP-induced proliferation in HT29 adenocarcinoma cells may involve a cAMP-Rap1/Ras-B-Raf-ERK signalling pathway.

Viable nonsense mutants for the essential gene SUP45 of Saccharomyces cerevisiae.

BACKGROUND: Termination of protein synthesis in eukaryotes involves at least two polypeptide release factors (eRFs) - eRF1 and eRF3. The highly conserved translation termination factor eRF1 in Saccharomyces cerevisiae is encoded by the essential gene SUP45. RESULTS: We have isolated five sup45-n (n from nonsense) mutations that cause nonsense substitutions in the following amino acid positions of eRF1: Y53 --> UAA, E266 --> UAA, L283 --> UAA, L317 --> UGA, E385 --> UAA. We found that full-length eRF1 protein is present in all mutants, although in decreased amounts. All mutations are situated in a weak termination context. All these sup45-n mutations are viable in different genetic backgrounds, however their viability increases after growth in the absence of wild-type allele. Any of sup45-n mutations result in temperature sensitivity (37 degrees C). Most of the sup45-n mutations lead to decreased spore viability and spores bearing sup45-n mutations are characterized by limited budding after germination leading to formation of microcolonies of 4-20 cells. CONCLUSIONS: Nonsense mutations in the essential gene SUP45 can be isolated in the absence of tRNA nonsense suppressors.

Poly(A)-binding protein and eRF3 are associated in vivo in human and Xenopus cells.

An interaction between human poly(A)-binding protein (PABP) et human eRF3 has been demonstrated using a double-hybrid approach and in vitro assays. Here, we show that the binding of both proteins is conserved through evolution. We also demonstrate that the last 39 C-terminal amino acids of PABP contain the interface that interacts with eRF3. This region includes helix 5, identified by RMN, which is conserved in all known PABPs. Lastly, we demonstrate that eRF3 et PABP molecules interact in vivo.

Characterization of the poly(A) binding proteins expressed during oogenesis and early development of Xenopus laevis.

During vertebrate oogenesis and early embryogenesis, gene expression is governed mainly by translational control. The recruitment of Poly(A) Binding Protein (PABP) during poly(A) tail lengthening appears to be the key to translational activation during this period of development in Xenopus laevis. We showed that PABP1 and ePABP proteins are both present during oogenesis and early development. We selected ePABP as an eRF3 binding protein in a two-hybrid screening of a X. laevis cDNA library and demonstrated that this protein is associated with translational complexes. It can complement essential functions of the yeast homologue Pab1p. We discuss specific expression patterns of the finely tuned PABP1 and ePABP proteins.