Isolation and properties of genetically defined strains of the methylotrophic yeast Hansenula polymorpha CBS4732

Genetically defined strains of the yeast Hansenula polymorpha were constructed froth a clone of H. polymorpha CBS4732 with very low mating and sporulation abilities. Mating, spore viability, and the percentage of four-spore-containing asci were increased to a level at which tetrad analysis was possible. Auxotrophic mutations in 30 genes were isolated and used to construct strains with multiple markers for mapping studies, transformation with plasmid DNA, and mutant screening. Various other types of mutants were isolated and characterized, among them mutants that displayed an altered morphology, methanol-utilization deficient mutants and strains impaired in the biosynthesis of alcohol oxidase and catalase. Also, the mutability of H. polymorpha CBS4732 vs H. polymorpha NCYC495 was compared. The data revealed clear differences in frequencies of appearance and mutational spectra of some mutants isolated. Many of the mutants isolated had good mating abilities, and diploids resulting from their crossing displayed high sporulation frequencies and high spore viability. Most of the markers used revealed normal Mendelian segregation during meiosis. The frequency of tetratype spore formation was lower than in Saccharomyces cerevisiae suggesting a lower frequency of recombination during the second meiotic division. The properties of genetically defined strains of H. polymorpha CBS4732 as well as their advantages for genetics and molecular studies are discussed

Fusion of Small Peroxisomal Vesicles in Vitro Reconstructs an Early Step in the in Vivo Multistep Peroxisome Assembly Pathway of Yarrowia lipolytica

We have identified and purified six subforms of peroxisomes, designated P1 to P6, from the yeast, Yarrowia lipolytica. An analysis of trafficking of peroxisomal proteins in vivo suggests the existence of a multistep peroxisome assembly pathway in Y. lipolytica. This pathway operates by conversion of peroxisomal subforms in the direction P1, P2→P3→P4→P5→P6 and involves the import of various peroxisomal proteins into distinct vesicular intermediates. We have also reconstituted in vitro the fusion of the earliest intermediates in the pathway, small peroxisomal vesicles P1 and P2. Their fusion leads to the formation of a larger and more dense peroxisomal vesicle, P3. Fusion of P1 and P2 in vitro requires cytosol and ATP hydrolysis and is inhibited by antibodies to two membrane-associated ATPases of the AAA family, Pex1p and Pex6p. We provide evidence that the fusion in vitro of P1 and P2 peroxisomes reconstructs an actual early step in the peroxisome assembly pathway operating in vivo in Y. lipolytica

Identification of common variants influencing risk of the tauopathy progressive supranuclear palsy

CurePSP Foundation, the Peebler PSP Research Foundation, and National Institutes on Health (NIH) grants R37 AG 11762, R01 PAS-03-092, P50 NS72187, P01 AG17216 [National Institute on Aging(NIA)/NIH], MH057881 and MH077930 [National Institute of Mental Health (NIMH)]. Work was also supported in part by the NIA Intramural Research Program, the German National Genome Research Network (01GS08136-4) and the Deutsche Forschungsgemeinschaft (HO 2402/6-1), Prinses Beatrix Fonds (JCvS, 01–0128), the Reta Lila Weston Trust and the UK Medical Research Council (RdS: G0501560). The Newcastle Brain Tissue Resource provided tissue and is funded in part by a grant from the UK Medical Research Council (G0400074), by the Newcastle NIHR Biomedical Research Centre in Ageing and Age Related Diseases to the Newcastle upon Tyne Hospitals NHS Foundation Trust, and by a grant from the Alzheimer’s Society and Alzheimer’s Research Trust as part of the Brains for Dementia Resarch Project. We acknowledge the contribution of many tissue samples from the Harvard Brain Tissue Resource Center. We also acknowledge the 'Human Genetic Bank of Patients affected by Parkinson Disease and parkinsonism' (http://www.parkinson.it/dnabank.html) of the Telethon Genetic Biobank Network, supported by TELETHON Italy (project n. GTB07001) and by Fondazione Grigioni per il Morbo di Parkinson. The University of Toronto sample collection was supported by grants from Wellcome Trust, Howard Hughes Medical Institute, and the Canadian Institute of Health Research. Brain-Net-Germany is supported by BMBF (01GI0505). RdS, AJL and JAH are funded by the Reta Lila Weston Trust and the PSP (Europe) Association. RdS is funded by the UK Medical Research Council (Grant G0501560) and Cure PSP+. ZKW is partially supported by the NIH/NINDS 1RC2NS070276, NS057567, P50NS072187, Mayo Clinic Florida (MCF)Research Committee CR programs (MCF #90052030 and MCF #90052030), and the gift from Carl Edward Bolch, Jr., and Susan Bass Bolch (MCF #90052031/PAU #90052). The Mayo Clinic College of Medicine would like to acknowledge Matt Baker, Richard Crook, Mariely DeJesus-Hernandez and Nicola Rutherford for their preparation of samples. PP was supported by a grant from the Government of Navarra ("Ayudas para la Realización de Proyectos de Investigación" 2006–2007) and acknowledges the "Iberian Atypical Parkinsonism Study Group Researchers", i.e. Maria A. Pastor, Maria R. Luquin, Mario Riverol, Jose A. Obeso and Maria C Rodriguez-Oroz (Department of Neurology, Clínica Universitaria de Navarra, University of Navarra, Pamplona, Spain), Marta Blazquez (Neurology Department, Hospital Universitario Central de Asturias, Oviedo, Spain), Adolfo Lopez de Munain, Begoña Indakoetxea, Javier Olaskoaga, Javier Ruiz, José Félix Martí Massó (Servicio de Neurología, Hospital Donostia, San Sebastián, Spain), Victoria Alvarez (Genetics Department, Hospital Universitario Central de Asturias, Oviedo, Spain), Teresa Tuñon (Banco de Tejidos Neurologicos, CIBERNED, Hospital de Navarra, Navarra, Spain), Fermin Moreno (Servicio de Neurología, Hospital Ntra. Sra. de la Antigua, Zumarraga, Gipuzkoa, Spain), Ainhoa Alzualde (Neurogenétics Department, Hospital Donostia, San Sebastián, Spain)

The peroxisome: still a mysterious organelle

More than half a century of research on peroxisomes has revealed unique features of this ubiquitous subcellular organelle, which have often been in disagreement with existing dogmas in cell biology. About 50 peroxisomal enzymes have so far been identified, which contribute to several crucial metabolic processes such as β-oxidation of fatty acids, biosynthesis of ether phospholipids and metabolism of reactive oxygen species, and render peroxisomes indispensable for human health and development. It became obvious that peroxisomes are highly dynamic organelles that rapidly assemble, multiply and degrade in response to metabolic needs. However, many aspects of peroxisome biology are still mysterious. This review addresses recent exciting discoveries on the biogenesis, formation and degradation of peroxisomes, on peroxisomal dynamics and division, as well as on the interaction and cross talk of peroxisomes with other subcellular compartments. Furthermore, recent advances on the role of peroxisomes in medicine and in the identification of novel peroxisomal proteins are discussed

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders

Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.Peer reviewe