Conserved expression of vertebrate microvillar gene homologs in choanocytes of freshwater sponges

International audienceBackground: The microvillus is a versatile organelle that serves important functions in disparate animal cell types. However, from a molecular perspective, the microvillus has been well studied in only a few, predominantly vertebrate, contexts. Little is known about how differences in microvillar structure contribute to differences in function, and how these differences evolved. We sequenced the transcriptome of the freshwater sponge, Ephydatia muelleri, and examined the expression of vertebrate microvillar gene homologs in choanocytes—the only microvilli-bearing cell type present in sponges. Sponges offer a distant phylogenetic comparison with vertebrates, and choanocytes are central to discussions about early animal evolution due to their similarity with choanoflagellates, the single-celled sister line-age of modern animals. Results: We found that, from a genomic perspective, sponges have conserved homologs of most vertebrate microvillar genes, most of which are expressed in choanocytes, and many of which exhibit choanocyte-specific or choanocyte-enriched expression. Possible exceptions include the cadherins that form intermicrovillar links in the enterocyte brush border and hair cell stereocilia of vertebrates and cnidarians. No obvious orthologs of these proteins were detected in sponges, but at least four candidate cadherins were identified as choanocyte-enriched and might serve this function. In contrast to the evidence for conserved microvillar structure in sponges and vertebrates, we found that choanoflagellates and ctenophores lack homologs of many fundamental microvillar genes, suggesting that microvillar structure may diverge significantly in these lineages, warranting further study. Conclusions: The available evidence suggests that microvilli evolved early in the prehistory of modern animals and have been repurposed to serve myriad functions in different cellular contexts. Detailed understanding of the sequence by which different microvilli-bearing cell/tissue types diversified will require further study of microvillar composition and development in disparate cell types and lineages. Of particular interest are the microvilli of choano-flagellates, ctenophores, and sponges, which collectively bracket the earliest events in animal evolution

Performance on Indirect Measures of Race Evaluation Predicts Amygdala Activation

We used fMRI to explore the neural substrates involved in the unconscious evaluation of Black and White social groups. Specifically, we focused on the amygdala, a subcortical structure known to play a role in emotional learning and evaluation. In Experiment 1, White American subjects observed faces of unfamiliar Black and White males. The strength of amygdala activation to Black-versus-White faces was correlated with two indirect (unconscious) measures of race evaluation (Implicit Association Test [IAT] and potentiated startle), but not with the direct (conscious) expression of race attitudes. In Experiment 2, these patterns were not obtained when the stimulus faces belonged to familiar and positively regarded Black and White individuals. Together, these results suggest that amygdala and behavioral responses to Black-versus-White faces in White subjects reflect cultural evaluations of social groups modified by individual experience.Psycholog

Lattice congruences of the weak order

We study the congruence lattice of the poset of regions of a hyperplane arrangement, with particular emphasis on the weak order on a finite Coxeter group. Our starting point is a theorem from a previous paper which gives a geometric description of the poset of join-irreducibles of the congruence lattice of the poset of regions in terms of certain polyhedral decompositions of the hyperplanes. For a finite Coxeter system (W,S) and a subset K of S, let \eta_K:w \mapsto w_K be the projection onto the parabolic subgroup W_K. We show that the fibers of \eta_K constitute the smallest lattice congruence with 1\equiv s for every s\in(S-K). We give an algorithm for determining the congruence lattice of the weak order for any finite Coxeter group and for a finite Coxeter group of type A or B we define a directed graph on subsets or signed subsets such that the transitive closure of the directed graph is the poset of join-irreducibles of the congruence lattice of the weak order.Comment: 26 pages, 4 figure

Control of human endometrial stromal cell motility by PDGF-BB, HB-EGF and trophoblast-secreted factors

Human implantation involves extensive tissue remodeling at the fetal-maternal interface. It is becoming increasingly evident that not only trophoblast, but also decidualizing endometrial stromal cells are inherently motile and invasive, and likely contribute to the highly dynamic processes at the implantation site. The present study was undertaken to further characterize the mechanisms involved in the regulation of endometrial stromal cell motility and to identify trophoblast-derived factors that modulate migration. Among local growth factors known to be present at the time of implantation, heparin-binding epidermal growth factor-like growth factor (HB-EGF) triggered chemotaxis (directed locomotion), whereas platelet-derived growth factor (PDGF)-BB elicited both chemotaxis and chemokinesis (non-directed locomotion) of endometrial stromal cells. Supernatants of the trophoblast cell line AC-1M88 and of first trimester villous explant cultures stimulated chemotaxis but not chemokinesis. Proteome profiling for cytokines and angiogenesis factors revealed neither PDGF-BB nor HB-EGF in conditioned media from trophoblast cells or villous explants, while placental growth factor, vascular endothelial growth factor and PDGF-AA were identified as prominent secretory products. Among these, only PDGF-AA triggered endometrial stromal cell chemotaxis. Neutralization of PDGF-AA in trophoblast conditioned media, however, did not diminish chemoattractant activity, suggesting the presence of additional trophoblast-derived chemotactic factors. Pathway inhibitor studies revealed ERK1/2, PI3 kinase/Akt and p38 signaling as relevant for chemotactic motility, whereas chemokinesis depended primarily on PI3 kinase/Akt activation. Both chemotaxis and chemokinesis were stimulated upon inhibition of Rho-associated, coiled-coil containing protein kinase. The chemotactic response to trophoblast secretions was not blunted by inhibition of isolated signaling cascades, indicating activation of overlapping pathways in trophoblast-endometrial communication. In conclusion, trophoblast signals attract endometrial stromal cells, while PDGF-BB and HB-EGF, although not identified as trophoblast-derived, are local growth factors that may serve to fine-tune directed and non-directed migration at the implantation site

The Rewiring of Ubiquitination Targets in a Pathogenic Yeast Promotes Metabolic Flexibility, Host Colonization and Virulence

Funding: This work was funded by the European Research Council [http://erc.europa.eu/], AJPB (STRIFE Advanced Grant; C-2009-AdG-249793). The work was also supported by: the Wellcome Trust [www.wellcome.ac.uk], AJPB (080088, 097377); the UK Biotechnology and Biological Research Council [www.bbsrc.ac.uk], AJPB (BB/F00513X/1, BB/K017365/1); the CNPq-Brazil [http://cnpq.br], GMA (Science without Borders fellowship 202976/2014-9); and the National Centre for the Replacement, Refinement and Reduction of Animals in Research [www.nc3rs.org.uk], DMM (NC/K000306/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgments We thank Dr. Elizabeth Johnson (Mycology Reference Laboratory, Bristol) for providing strains, and the Aberdeen Proteomics facility for the biotyping of S. cerevisiae clinical isolates, and to Euroscarf for providing S. cerevisiae strains and plasmids. We are grateful to our Microscopy Facility in the Institute of Medical Sciences for their expert help with the electron microscopy, and to our friends in the Aberdeen Fungal Group for insightful discussions.Peer reviewedPublisher PD

The LRRK2 Arg1628Pro variant is a risk factor for Parkinson's disease in the Chinese population

The c.G4883C variant in the leucine-rich repeat kinase 2 (LRRK2) gene (protein effect: Arg1628Pro) has been recently proposed as a second risk factor for sporadic Parkinson's disease in the Han Chinese population (after the Gly2385Arg variant). In this paper, we analyze the Arg1628Pro variant and the associated haplotype in a large sample of 1,337 Han subjects (834 patients and 543 controls) ascertained from a single referral center in Taiwan. In our sample, the Arg1628Pro allele was more frequent among patients (3.8%) than among controls (1.8%; p = 0.004, OR 2.13, 95% CI 1.29-3.52). Sixty heterozygous and two homozygous carriers of the Arg1628Pro variant were identified among the patients, of which only one was also a carrier of the LRRK2 Gly2385Arg variant. We also show that carriers of the Arg1628Pro variant share a common, extended haplotype, suggesting a founder effect. Parkinson's disease onset age was similar in patients who carried the Arg1628Pro variant and in those who did not carry it. Our data support the contention that the Arg1628Pro variant is a second risk factor for Parkinson's disease in the Han Chinese population. Adding the estimated effects of Arg1628Pro (population attributable risk [PAR] ∼4%) and Gly2385Arg variants (PAR ∼6%) yields a total PAR of ∼10%

Erros inatos do metabolismo no Hospital das Clínicas de Ribeirão Preto. Um legado de múltiplas especialidades

Inborn errors of metabolism (IEM) are genetic diseases, mostly due to enzyme deficiencies leading to severe metabolic damages, increasingly diagnosed. The aim is to describe the history of the development of IEM diagnosis and treatment in the Hospital of Clinics of Ribeirão Preto, São Paulo University (HCFMRP-USP). At the beginnings of the Post-Graduate Programs in the School of Medicine of Ribeirão Preto of São Paulo University (FMRP-USP), the first thesis on IEM was performed in 1980 on cystinuria in the area of Genetics; G6PD goal was the second in 1987 in Pediatrics. Since that time, IEM diagnosis was possible, in the sequence, due to the chromatography of amino acids routine by the Center for Protein Chemistry, FMRP-USP in 1984, the partnership with the Department of Genetics, Hospital of Clinics of Porto Alegre. RS in 1988 and the urine screening in the Nutrology Laboratory of FMRP-USP, that resulted of a Master in Neurology in 1990. In the last two decades: the specialized outpatients clinics, the Program for Neonatal Screening, treatment by enzyme replacement and support of the Stem Cell Transplantation Center were implemented. It is noteworthy that by 2009, just one more thesis was presented. The perspective for the development of this area is the consolidation of a line of research focused exclusively on the EIM in FMRP-USP.Erros inatos do metabolismo (EIM) são doenças genéticas decorrentes, em sua maioria, de deficiências enzimáticas que levam a graves distúrbios metabólicos, e que vem sendo cada vez mais diagnosticados. No presente texto relata-se um histórico sobre a evolução da abordagem diagnóstica e tratamento de EIM no HCFMRP-USP. Na FMRP-USP os EIM vêm sendo objeto de estudo em pós-graduação desde a década de 1980, dado o grande apelo clínico nas áreas de Genética Clínica, Pediatria e Neurologia Infantil, até então com auxílio do Laboratório de Patologia, além de convênio com a APAE de São Paulo para o diagnóstico de fenilcetonúria. Já iniciados os Programas de Pós-Graduação da FMRP-USP, a primeira tese a respeito foi realizada em 1980, sobre cistinúria, na Área de Genética; deficiência de glicose-6-fostato desidrogenase (G6PD) foi objetivo da segunda, em 1987, na de Pediatria. Desde essa época, garantem a rotina de investigação a realização da cromatografia de aminoácidos pelo Centro de Química de Proteínas da FMRP-USP, o convênio com o Serviço de Genética do HC de Porto Alegre-RS e a triagem urinária no Laboratório de Nutrologia, este, resultado de Mestrado em Neurologia em 1990. Nas duas últimas décadas vieram os ambulatórios especializados, o Programa de Triagem Neonatal, o tratamento por Reposição Enzimática e o apoio do Centro de Transplante de Células Tronco. Cabe ressaltar que até 2009, apenas mais uma tese foi apresentada. A perpectiva para o desenvolvimento dessa área é a consolidação de uma linha de pesquisa voltada exclusivamente para os EIM na FMRP-USP

Efeitos do chumbo sobre o cérebro em desenvolvimento

No presente trabalho procedeu-se à revisão de literatura dos efeitos do chumbo sobre o cérebro, com enfoque no desenvolvimento infantil. O chumbo pode permanecer no organismo durante toda a vida do indivíduo, sendo difícil a sua remoção. Não há nível estável seguro, considerando sua passagem lenta dos ossos para o sangue, com aceleração em condições como na gravidez. Há evidências de que o cérebro imaturo é um dos mais importantes alvos, e as pesquisas apontam para consequências mais tardias, em processos cerebrodegenerativos no adulto. Na infância, mesmo níveis sanguineos inferiores a 10 ?g/dL podem afetar a cognição. Estudos clínicos registram seus efeitos tóxicos na criança em idade escolar e na adolescência trazendo prejuízos motores, sensoriais, adaptativos, cognitivos e comportamentais, destacando-se a delinquência. Conclui-se, pela gravidade dos efeitos e dificuldade de tratamento, que o enfoque na orientação populacional sobre as medidas preventivas da exposição ao chumbo é prioritário.This work is a review of the lead effects on the brain, focusing on child development. Lead can remain in the body throughout the life, being difficulty its removal, and there is no safe stable level, considering its slow passage of the bones for blood, but acceleration in moments such as pregnancy. There is evidence that the immature brain is one of the most important targets. Surveys point to later consequence in adult life, as the degenerative brain disease. In the childhood, even blood levels under 10 ?g/dL may affect cognition. Clinical studies record their toxic effects in childhood and adolescence, bringing motor, sensory, adaptive, cognitive and behavioral losses, highlighting the crime itself. It is due to the severe effects on the developing nervous system and treatment difficulties, that the priority is the population guidance on the preventive measures of exposure to lead

The LRRK2 signalling system

The LRRK2 gene is a major contributor to genetic risk for Parkinson's disease and understanding the biology of the leucine-rich repeat kinase 2 (LRRK2, the protein product of this gene) is an important goal in Parkinson's research. LRRK2 is a multi-domain, multi-activity enzyme and has been implicated in a wide range of signalling events within the cell. Because of the complexities of the signal transduction pathways in which LRRK2 is involved, it has been challenging to generate a clear idea as to how mutations and disease associated variants in this gene are altered in disease. Understanding the events in which LRRK2 is involved at a systems level is therefore critical to fully understand the biology and pathobiology of this protein and is the subject of this review

LRRK2 at the interface of autophagosomes, endosomes and lysosomes

Over the past 20 years, substantial progress has been made in identifying the underlying genetics of Parkinson’s disease (PD). Of the known genes, LRRK2 is a major genetic contributor to PD. However, the exact function of LRRK2 remains to be elucidated. In this review, we discuss how familial forms of PD have led us to hypothesize that alterations in endomembrane trafficking play a role in the pathobiology of PD. We will discuss the major observations that have been made to elucidate the role of LRRK2 in particular, including LRRK2 animal models and high-throughput proteomics approaches. Taken together, these studies strongly support a role of LRRK2 in vesicular dynamics. We also propose that targeting these pathways may not only be beneficial for developing therapeutics for LRRK2-driven PD, but also for other familial and sporadic cases