Fibroblasts co-expressing tyrosinase and the b-protein synthesise both eumelanin and phaeomelanin

AbstractMelanin synthesis in the mouse involves the interaction of many pigmentation loci. Tyrosinase, the product of the albino (c) locus, catalyses the first step of the pathway. The brown (b) locus protein has significant homology to tyrosinase and controls black/brown coat coloration, but its function is controversial. To investigate the function of the b-protein and its interaction with tyrosinase, we established cell lines expressing both tyrosinase and the b-protein by transfecting tyrosinase-expressing fibroblasts with a b-protein expression vector. The tyrosinase-expressing parent line does not have l-dopachrome tautomerase activity, but this enzyme is detectable in double transfectants as well as in fibroblasts expressing the b-protein alone. Cells expressing both proteins have a higher steady-state level of tyrosinase than fibroblasts expressing tyrosinase alone, and contain elevated levels of melanin intermediates. This is thought to result from interaction of tyrosinase with the b-protein. Only phaeomelanin is detectable in fibroblasts expressing tyrosinase alone, whereas double transfectants synthesise significantly more phaeomelanin and detectable eumelanin

GBA and APOE Impact Cognitive Decline in Parkinson's Disease : A 10-Year Population-Based Study

Acknowledgments: We would like to thank all participants, study personnel from each study, and funders of individual studies and of PICC. We would like to thank Artur Wozniak and Adrian Martin from the University of Aberdeen, Data Management Department, for help in developing the PICC database. We acknowledge the contributions of members of the individual study groups as detailed below. Members of PICC Steering Group: Dr. Angus D. Macleod, Dr. Carl E. Counsell (Chair), University of Aberdeen, UK; Prof. Ole-Bjørn Tysnes, University of Bergen, Norway; Marta Camacho, Dr. Caroline WilliamsGray, University of Cambridge, UK; Dr. Rachael A. Lawson, Newcastle University, UK; Dr. Jodi Maple-Grødem, Prof. Guido Alves, Stavanger University Hospital, Norway; Prof. Lars Forgren, Umeå University, Sweden. CamPaIGN study: Roger A. Barker, Thomas Foltynie, Sarah L. Mason, Caroline H. Williams-Gray. ICICLE-PD Study: David Burn, Lynn Rochester, Alison J. Yarnall, Rachael A. Lawson, Gordon W. Duncan, Tien K. Khoo. NYPUM Study: Lars Forsgren, Jan Linder, Mona Edström, Jörgen Andersson, Linda Eriksson, David Bäckström, Gun-Marie Hariz, Magdalena Domellöf. ParkWest Study: ParkWest Principal investigators: Guido Alves (Norwegian Centre for Movement Disorders, Stavanger University Hospital) and Ole-Bjørn Tysnes (Haukeland University Hospital). Study personnel: Michaela Dreetz Gjerstad, Kenn Freddy Pedersen, Elin Bjelland Forsaa, Veslemøy Hamre Frantzen, Anita Laugaland, Jodi MapleGrødem, Johannes Lange, Karen Simonsen, Eldbjørg Fiske and Ingvild Dalen (Stavanger University Hospital); Bernd Müller, Geir Olve Skeie and Marit Renså (Haukeland University Hospital); Wenche Telstad, Aliaksei Labusau and Jane Kastet (Førde Hospital); Ineke HogenEsch, Marianne Kjerandsen and Liv Kari Håland (Haugesund Hospital); Karen Herlofson, Solgunn Ongre, and Siri Bruun (Sørlandet Hospital Arendal). PICNICS study: Roger A. Barker, Marta Camacho, Gemma Cummins, Jonathan R. Evans, David P. Breen, Ruwani S. Wijeyekoon, Caroline H. Williams-Gray. PINE Study: Medical: Carl E. Counsell, Kate S. M. Taylor, Robert Caslake, Angus D. Macleod, David J. M. McGhee, Diane Swallow; Research nurse/assistant: Joanne Gordon, Clare Harris, Ann Hayman, Nicola Johannesson, Hazel Forbes; Data management: Valerie Angus, Alasdair Finlayson, David Dawson, Katie Wilde, David Ritchie, Artur Wozniak; Statisticians: Neil Scott, Shona Fielding; Radiology: Prof. Alison Murray; Pathology: Ishbel Gall, Dr. James MacKenzie, Prof. Colin Smith; Secretarial: Aileen Sylvester, Susan Mitchell, Pam Rebecca, Ann Christie, and Diane McCosh. Funding agencies: This work was supported by the Research Council of Norway (287842). The CamPaIGN study has received funding from the Wellcome Trust, the Medical Research Council, the Patrick Berthoud Trust, and the NIHR Cambridge Biomedical Research Centre (BRC-1215-20014). The ICICLE-PD study was funded by Parkinson’s UK (J-0802, G-1301, G-1507) and supported by the Lockhart Parkinson’s Disease Research Fund, National Institute for Health Research (NIHR) Newcastle Biomedical Research Unit and Centre based at Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University. The NYPUM study was supported by grants from the Swedish Medical Research Council, Erling-Persson Foundation, the Swedish Brain Foundation (Hjärnfonden), Umeå University, Västerbotten County Council, King Gustaf V and Queen Victoria Freemason Foundation, Swedish Parkinson Foundation, Swedish Parkinson Research Foundation, Kempe Foundation, Swedish PD Association, the European Research Council, and the Knut and Alice Wallenberg Foundation. The Norwegian ParkWest study has received funding from the Research Council of Norway (177966), the Western Norway Regional Health Authority (911218), the Norwegian Parkinson’s Research Foundation, and Rebergs Legacy. The PICNICS study was funded by the Cure Parkinson’s Trust, the Van Geest Foundation, the Medical Research Council, Parkinson’s UK, and the NIHR Cambridge Biomedical Research Centre (BRC-1215-20014). The PINE study was funded by Parkinson’s UK (grant numbers G0502, G0914, and G1302), the Scottish Chief Scientist Office (CAF/12/05, PCL/17/10), Academy of Medical Sciences, NHS Grampian endowments, the BMA Doris Hillier award, RS Macdonald Trust, the BUPA Foundation, and SPRING. The PICC collaboration has been supported by The Chief Scientist Office of the Scottish Government (PCL/17/10), the Academy of Medical Sciences, Parkinson’s UK (initial collaborator meeting) and the Norwegian Association for Public Health. C.R.S.’s work was supported by NIH grants NINDS/NIA R01NS115144, U01NS095736, U01NS100603, and the American Parkinson Disease Association Center for Advanced Parkinson Research. This research was funded in whole, or in part by the UKRI Medical Research Council [MR/R007446/1]. For the purpose of open access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission.Peer reviewedPublisher PD

Discovery and functional prioritization of Parkinson's disease candidate genes from large-scale whole exome sequencing.

BACKGROUND: Whole-exome sequencing (WES) has been successful in identifying genes that cause familial Parkinson's disease (PD). However, until now this approach has not been deployed to study large cohorts of unrelated participants. To discover rare PD susceptibility variants, we performed WES in 1148 unrelated cases and 503 control participants. Candidate genes were subsequently validated for functions relevant to PD based on parallel RNA-interference (RNAi) screens in human cell culture and Drosophila and C. elegans models. RESULTS: Assuming autosomal recessive inheritance, we identify 27 genes that have homozygous or compound heterozygous loss-of-function variants in PD cases. Definitive replication and confirmation of these findings were hindered by potential heterogeneity and by the rarity of the implicated alleles. We therefore looked for potential genetic interactions with established PD mechanisms. Following RNAi-mediated knockdown, 15 of the genes modulated mitochondrial dynamics in human neuronal cultures and four candidates enhanced α-synuclein-induced neurodegeneration in Drosophila. Based on complementary analyses in independent human datasets, five functionally validated genes-GPATCH2L, UHRF1BP1L, PTPRH, ARSB, and VPS13C-also showed evidence consistent with genetic replication. CONCLUSIONS: By integrating human genetic and functional evidence, we identify several PD susceptibility gene candidates for further investigation. Our approach highlights a powerful experimental strategy with broad applicability for future studies of disorders with complex genetic etiologies

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome