Expansion of the calcium hypothesis of brain aging and Alzheimer's disease: minding the store

Evidence accumulated over more than two decades has implicated Ca2+ dysregulation in brain aging and Alzheimer's disease (AD), giving rise to the Ca2+ hypothesis of brain aging and dementia. Electrophysiological, imaging, and behavioral studies in hippocampal or cortical neurons of rodents and rabbits have revealed aging-related increases in the slow afterhyperpolarization, Ca2+ spikes and currents, Ca2+ transients, and L-type voltage-gated Ca2+ channel (L-VGCC) activity. Several of these changes have been associated with age-related deficits in learning or memory. Consequently, one version of the Ca2+ hypothesis has been that increased L-VGCC activity drives many of the other Ca2+-related biomarkers of hippocampal aging. In addition, other studies have reported aging- or AD model-related alterations in Ca2+ release from ryanodine receptors (RyR) on intracellular stores. The Ca2+-sensitive RyR channels amplify plasmalemmal Ca2+ influx by the mechanism of Ca2+-induced Ca2+ release (CICR). Considerable evidence indicates that a preferred functional link is present between L-VGCCs and RyRs which operate in series in heart and some brain cells. Here, we review studies implicating RyRs in altered Ca2+ regulation in cell toxicity, aging, and AD. A recent study from our laboratory showed that increased CICR plays a necessary role in the emergence of Ca2+-related biomarkers of aging. Consequently, we propose an expanded L-VGCC/Ca2+ hypothesis, in which aging/pathological changes occur in both L-type Ca2+ channels and RyRs, and interact to abnormally amplify Ca2+ transients. In turn, the increased transients result in dysregulation of multiple Ca2+-dependent processes and, through somewhat different pathways, in accelerated functional decline during aging and AD

Expansion of the Calcium Hypothesis of Brain Aging and Alzheimer\u27s Disease: Minding the Store

Evidence accumulated over more than two decades has implicated Ca2+ dysregulation in brain aging and Alzheimer\u27s disease (AD), giving rise to the Ca2+ hypothesis of brain aging and dementia. Electrophysiological, imaging, and behavioral studies in hippocampal or cortical neurons of rodents and rabbits have revealed aging-related increases in the slow afterhyperpolarization, Ca2+ spikes and currents, Ca2+transients, and L-type voltage-gated Ca2+ channel (L-VGCC) activity. Several of these changes have been associated with age-related deficits in learning or memory. Consequently, one version of the Ca2+ hypothesis has been that increased L-VGCC activity drives many of the other Ca2+-related biomarkers of hippocampal aging. In addition, other studies have reported aging- or AD model-related alterations in Ca2+ release from ryanodine receptors (RyR) on intracellular stores. The Ca2+-sensitive RyR channels amplify plasmalemmal Ca2+ influx by the mechanism of Ca2+-induced Ca2+ release (CICR). Considerable evidence indicates that a preferred functional link is present between L-VGCCs and RyRs which operate in series in heart and some brain cells. Here, we review studies implicating RyRs in altered Ca+ regulation in cell toxicity, aging, and AD. A recent study from our laboratory showed that increased CICR plays a necessary role in the emergence of Ca2+-related biomarkers of aging. Consequently, we propose an expanded L-VGCC/Ca2+ hypothesis, in which aging/pathological changes occur in both L-type Ca2+ channels and RyRs, and interact to abnormally amplify Ca2+ transients. In turn, the increased transients result in dysregulation of multiple Ca2+-dependent processes and, through somewhat different pathways, in accelerated functional decline during aging and AD

Methods for Diagnosing and Treating Alzheimer\u27s Disease (AD) Using the Molecules that Stabilize Intracellular Calcium (CA\u3csub\u3e2+\u3c/sub\u3e) Release

The subject technology relates, in part, to a method of treating Alzheimer\u27s Disease (AD), early-stage AD, elevated risk of AD, mild cognitive impairment (MCI), or other forms of age-related cognitive decline in a subject in need thereof by administering to the subject a molecule that promotes calcium-release stabilization in ryanodine receptors (RyRs) and/or inosital triphosphate receptors (InsP3Rs) in brain cells. Diagnostic methods using calcium-release stabilizing immunophilins, junctophilins or calmodulin are also disclosed

FK506-Binding Protein 12.6/1b, a Negative Regulator of [Ca\u3csup\u3e2+\u3c/sup\u3e], Rescues Memory and Restores Genomic Regulation in the Hippocampus of Aging Rats

Hippocampal overexpression of FK506-binding protein 12.6/1b (FKBP1b), a negative regulator of ryanodine receptor Ca2+ release, reverses aging-induced memory impairment and neuronal Ca2+ dysregulation. Here, we tested the hypothesis that FKBP1b also can protect downstream transcriptional networks from aging-induced dysregulation. We gave hippocampal microinjections of FKBP1b-expressing viral vector to male rats at either 13 months of age (long-term, LT) or 19 months of age (short-term, ST) and tested memory performance in the Morris water maze at 21 months of age. Aged rats treated ST or LT with FKBP1b substantially outperformed age-matched vector controls and performed similarly to each other and young controls (YCs). Transcriptional profiling in the same animals identified 2342 genes with hippocampal expression that was upregulated/downregulated in aged controls (ACs) compared with YCs (the aging effect). Of these aging-dependent genes, 876 (37%) also showed altered expression in aged FKBP1b-treated rats compared with ACs, with FKBP1b restoring expression of essentially all such genes (872/876, 99.5%) in the direction opposite the aging effect and closer to levels in YCs. This inverse relationship between the aging and FKBP1b effects suggests that the aging effects arise from FKBP1b deficiency. Functional category analysis revealed that genes downregulated with aging and restored by FKBP1b were associated predominantly with diverse brain structure categories, including cytoskeleton, membrane channels, and extracellular region. Conversely, genes upregulated with aging but not restored by FKBP1b associated primarily with glial–neuroinflammatory, ribosomal, and lysosomal categories. Immunohistochemistry confirmed aging-induced rarefaction and FKBP1b-mediated restoration of neuronal microtubular structure. Therefore, a previously unrecognized genomic network modulating diverse brain structural processes is dysregulated by aging and restored by FKBP1b overexpression

Reversal of Aging-Related Neuronal Ca\u3csup\u3e2+\u3c/sup\u3e Dysregulation and Cognitive Impairment by Delivery of a Transgene Encoding FK506-Binding Protein 12.6/1b to the Hippocampus

Brain Ca(2+) regulatory processes are altered during aging, disrupting neuronal, and cognitive functions. In hippocampal pyramidal neurons, the Ca(2+)-dependent slow afterhyperpolarization (sAHP) exhibits an increase with aging, which correlates with memory impairment. The increased sAHP results from elevated L-type Ca(2+) channel activity and ryanodine receptor (RyR)-mediated Ca(2+) release, but underlying molecular mechanisms are poorly understood. Previously, we found that expression of the gene encoding FK506-binding protein 12.6/1b (FKBP1b), a small immunophilin that stabilizes RyR-mediated Ca(2+) release in cardiomyocytes, declines in hippocampus of aged rats and Alzheimer\u27s disease subjects. Additionally, knockdown/disruption of hippocampal FKBP1b in young rats augments neuronal Ca(2+) responses. Here, we test the hypothesis that declining FKBP1b underlies aging-related hippocampal Ca(2+) dysregulation. Using microinjection of adeno-associated viral vector bearing a transgene encoding FKBP1b into the hippocampus of aged male rats, we assessed the critical prediction that overexpressing FKBP1b should reverse Ca(2+)-mediated manifestations of brain aging. Immunohistochemistry and qRT-PCR confirmed hippocampal FKBP1b overexpression 4-6 weeks after injection. Compared to aged vector controls, aged rats overexpressing FKBP1b showed dramatic enhancement of spatial memory, which correlated with marked reduction of sAHP magnitude. Furthermore, simultaneous electrophysiological recording and Ca(2+) imaging in hippocampal neurons revealed that the sAHP reduction was associated with a decrease in parallel RyR-mediated Ca(2+) transients. Thus, hippocampal FKBP1b overexpression reversed key aspects of Ca(2+) dysregulation and cognitive impairment in aging rats, supporting the novel hypothesis that declining FKBP1b is a molecular mechanism underlying aging-related Ca(2+) dysregulation and unhealthy brain aging and pointing to FKBP1b as a potential therapeutic target. Significance Statement This paper reports critical tests of a novel hypothesis that proposes a molecular mechanism of unhealthy brain aging and possibly, Alzheimer\u27s disease. For more than 30 years, evidence has been accumulating that brain aging is associated with dysregulation of calcium in neurons. Recently, we found that FK506-binding protein 12.6/1b (FKBP1b), a small protein that regulates calcium, declines with aging in the hippocampus, a brain region important for memory. Here we used gene therapy approaches and found that raising FKBP1b reversed calcium dysregulation and memory impairment in aging rats, allowing them to perform a memory task as well as young rats. These studies identify a potential molecular mechanism of brain aging and may also have implications for treatment of Alzheimer\u27s disease

Expansion of the calcium hypothesis of brain aging and Alzheimer's disease: minding the store

-dependent processes and, through somewhat different pathways, in accelerated functional decline during aging and AD

Tests of the Equivalence Principle with Neutral Kaons

We test the Principle of Equivalence for particles and antiparticles, using CPLEAR data on tagged K0 and K0bar decays into pi^+ pi^-. For the first time, we search for possible annual, monthly and diurnal modulations of the observables |eta_{+-}| and phi_{+-}, that could be correlated with variations in astrophysical potentials. Within the accuracy of CPLEAR, the measured values of |eta_{+-}| and phi_{+-} are found not to be correlated with changes of the gravitational potential. We analyze data assuming effective scalar, vector and tensor interactions, and we conclude that the Principle of Equivalence between particles and antiparticles holds to a level of 6.5, 4.3 and 1.8 x 10^{-9}, respectively, for scalar, vector and tensor potentials originating from the Sun with a range much greater than the distance Earth-Sun. We also study energy-dependent effects that might arise from vector or tensor interactions. Finally, we compile upper limits on the gravitational coupling difference between K0 and K0bar as a function of the scalar, vector and tensor interaction range.Comment: 15 pages latex 2e, five figures, one style file (cernart.csl) incorporate

Research priorities in pediatric parenteral nutrition: a consensus and perspective from ESPGHAN/ESPEN/ESPR/CSPEN

We acknowledge all the authors of the ESPGHAN/ESPR/ESPEN/CSPEN pediatric parenteral nutrition guidelines for their contributions and vote (Christian Braegger, University Children’s Hospital, Zurich, Switzerland; Jiri Bronsky, University Hospital Motol, Prague, Czech Republic; Cristina Campoy, Department of Paediatrics, School of Medicine, University of Granada, Granada, Spain; Magnus Domellof, Department of Clinical Sciences, Pediatrics, Umeå University, Sweden; Nicholas Embleton, Newcastle University, Newcastle upon Tyne, UK; Mary Fewtrell, UCL Great Ormond Street Institute of Child Health, London, UK; Natasa Fidler, University Medical Centre Ljubljana, Ljubljana, Slovenia; Axel Franz, University Children’s Hospital, Tuebingen, Germany; Oliver Goulet, University Sordonne-Paris-Cite; Paris-Descartes Medical School, Paris, France; Corina Hartmann, Schneider Children’s Medical Center of Israel, Petach Tikva, Israel and Carmel Medical Center, Israel; Susan Hill, Great Ormond Street Hospital for Children, NHS Foundation Trust and UCL Institute of Child Health, London, UK; Iva Hojsak, Children’s Hospital Zagreb, University of Zagreb School of Medicine, University of J. J. Strossmayer School of Medicine Osijek, Croatia; Sylvia Iacobelli, CHU La Reunion, Saint Pierre, France; Frank Jochum, Ev. Waldkrankenhaus Spandau, Berlin, Germany; Koen Joosten, Department of Pediatrics and Pediatric Surgery, Intensive Care, Erasmus MC Sophia Children’s Hospital, Rotterdam, The Netherlands; Sanja Kolacek, Children’s Hospital, University of Zagreb School of Medicine, Zagreb, Croatia; Alexandre Lapillone, Paris-Descartes University, Paris, France; Szimonetta Lohner, Department of Pediatrics, University of Pecs, Pecs, Hungary; Dieter Mesotten, KU Leuven, Leuven, Belgium; Walter Mihatsch, Ulm University, Ulm, and Helios Hospital, Pforzheim, Germany; Francis Mimouni, Department of Pediatrics, Division of Neonatology, The Wilf Children’s Hospital, the Shaare Zedek Medical Center, Jerusalem, and the Tel Aviv University, Tel Aviv, Israel; Christian Molgaard, Department of Nutrition, Exercise and Sports, University of Copenhagen, and Paediatric Nutrition Unit, Rigshospitalet, Copenhagen, Denmark; Sissel Moltu, Oslo University Hospital, Oslo, Norway; Antonia Nomayo, Ev. Waldkrankenhaus Spandau, Berlin, Germany; John Puntis, The General Infirmary at Leeds, Leeds, UK; Arieh Riskin, Bnai Zion Medical Center, Rappaport Faculty of Medicine, Technion, Haifa, Israel; Miguel Saenz de Pipaon, Department of Neonatology, La Paz University Hospital, Red de Salud Materno Infantil y Desarrollo e SAMID, Universidad Autonoma de Madrid, Madrid, Spain; Raanan Shamir, Schneider Children’s Medical Center of Israel, Petach Tikva, Israel; Tel Aviv University, Tel Aviv, Israel; Peter Szitanyi, General University Hospital, First Faculty of Medicine, Charles University in Prague, Czech Republic; Merit Tabbers, Emma Children’s Hospital, Amsterdam UMC, Amsterdam, The Netherlands; Chris van den Akker, Emma Children’s Hospital, Amsterdam UMC, Amsterdam, The Netherlands; Hans van Goudoever, Emma Children’s Hospital, Amsterdam UMC, Amsterdam, The Netherlands; Sacha Verbruggen, Department of Pediatrics and Pediatric Surgery, Intensive Care, Erasmus MC-Sophia Children’s Hospital, Rotterdam, The Netherlands; Cai Wei, Shanghai Jiao Tong University, Shanghai, China; Weihui Yan, Department of Gastroenterology and Nutrition, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China) and the members of the ESPR Section on Nutrition, Gastroenterology and Metabolism (Fredrik Ahlsson, Uppsala University Children’s Hospital and Department of Women’s and Children’s Health, Uppsala University, Uppsala, Sweden; Sertac Arslanoglu, Division of Neonatology, Department of Pediatrics, Istanbul Medeniyet University, Istanbul, Turkey; Wolfgang Bernhard, Department of Neonatology, Children’s Hospital, Faculty of Medicine, Eberhard-Karls- University, Tübingen, Germany; Janet Berrington, Newcastle Neonatal Service, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK; Signe Bruun, Hans Christian Andersen Hospital for Children and Adolescents, Odense University Hospital, Odense, Denmark; Christoph Fusch, Department of Pediatrics, Paracelsus Medical School, General Hospital of Nuremberg, Nuremberg, Germany; Shalabh Garg, South Tees Hospitals, Middlesborough, UK; Maria Gianni, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy; Ann Hellstrom, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden; Claus Klingenberg, Department of Pediatrics and Adolescence Medicine, University Hospital of North Norway, Tromsø, Norway; Helen Mactier, Neonatal Unit, Princess Royal Maternity Hospital, Glasgow, UK; Neena Modi, Section of Neonatal Medicine, Department of Medicine, Chelsea and Westminster Campus, Imperial College London, London, UK; Niels Rochow, Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada; Paola Rogerro, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy; Umberto Simeoni, Division of Pediatrics, CHUV & University of Lausanne, Lausanne, Switzerland; Atul Singhal, Paediatric Nutrition, UCL Great Ormond Street Institute of Child Health, London, UK.; Ulrich Thome, Department of Neonatology, Universitatsklinikum Leipzig, Leipzig, Germany; Anne Twomey, Department of Neonatology, The National Maternity Hospital, Dublin, Ireland; Mireille Vanpee, Karolinska University Hospital, Stockholm, Sweden; Gitte Zachariassen, Hans Christian Andersen Hospital for Children and Adolescents, Odense University Hospital, Odense, Denmark) for their vote.Parenteral nutrition is used to treat children that cannot be fully fed by the enteral route. While the revised ESPGHAN/ ESPEN/ESPR/CSPEN pediatric parenteral nutrition guidelines provide clear guidance on the use of parenteral nutrition in neonates, infants, and children based on current available evidence, they have helped to crystallize areas where research is lacking or more studies are needed in order to refine recommendations. This paper collates and discusses the research gaps identified by the authors of each section of the guidelines and considers each nutrient or group of nutrients in turn, together with aspects around delivery and organization. The 99 research priorities identified were then ranked in order of importance by clinicians and researchers working in the field using a survey methodology. The highest ranked priority was the need to understand the relationship between total energy intake, rapid catch-up growth, later metabolic function, and neurocognitive outcomes. Research into the optimal intakes of macronutrients needed in order to achieve optimal outcomes also featured prominently. Identifying research priorities in PN should enable research to be focussed on addressing key issues. Multicentre trials, better definition of exposure and outcome variables, and long-term metabolic and developmental follow-up will be key to achieving this

multi‐patient dose synthesis of [18F]Flumazenil via a copper‐mediated 18F‐fluorination

Background Flumazenil (FMZ) is a functionally silent imidazobenzodiazepine which binds to the benzodiazepine binding site of approximately 75% of the brain γ-aminobutyric acid-A receptors (GABAARs). Positron Emission Tomography (PET) imaging of the GABAARs with [11C]FMZ has been used to evidence alterations in neuronal density, to assess target engagement of novel pharmacological agents, and to study disorders such as epilepsy and Huntington’s disease. Despite the potential of FMZ PET imaging the short half-life (t1/2) of carbon-11 (20 min) has limited the more widespread clinical use of [11C]FMZ. The fluorine-18 (18F) isotopologue with a longer t1/2 (110 min) is ideally suited to address this drawback. However, the majority of current radiochemical methods for the synthesis of [18F]FMZ are non-trivial and low yielding. We report a robust, automated protocol that is good manufacturing practice (GMP) compatible, and yields multi-patient doses of [18F]FMZ. Results The fully automated synthesis was developed on the Trasis AllinOne (AIO) platform using a single-use cassette. [18F]FMZ was synthesized in a one-step procedure from [18F]fluoride, via a copper-mediated 18F-fluorination of a boronate ester precursor. Purification was performed by semi-preparative radio-HPLC and the collected fraction formulated directly into the final product vial. The overall process from start of synthesis to delivery of product is approximately 55 min. Starting with an initial activity of 23.6 ± 5.8 GBq (n = 3) activity yields of [18F]FMZ were 8.0 ± 1 GBq (n = 3). The synthesis was successfully reproduced at two independent sites, where the product passed quality control release criteria in line with the European Pharmacopoeia standards and ICH Q3D(R1) guidelines to be suitable for human use. Conclusion Reported is a fully automated cassette-based synthesis of [18F]FMZ that is Good Manufacturing Practice (GMP) compatible and produces multi-patient doses of [18F]FMZ

The SysteMHC Atlas project.

Mass spectrometry (MS)-based immunopeptidomics investigates the repertoire of peptides presented at the cell surface by major histocompatibility complex (MHC) molecules. The broad clinical relevance of MHC-associated peptides, e.g. in precision medicine, provides a strong rationale for the large-scale generation of immunopeptidomic datasets and recent developments in MS-based peptide analysis technologies now support the generation of the required data. Importantly, the availability of diverse immunopeptidomic datasets has resulted in an increasing need to standardize, store and exchange this type of data to enable better collaborations among researchers, to advance the field more efficiently and to establish quality measures required for the meaningful comparison of datasets. Here we present the SysteMHC Atlas (https://systemhcatlas.org), a public database that aims at collecting, organizing, sharing, visualizing and exploring immunopeptidomic data generated by MS. The Atlas includes raw mass spectrometer output files collected from several laboratories around the globe, a catalog of context-specific datasets of MHC class I and class II peptides, standardized MHC allele-specific peptide spectral libraries consisting of consensus spectra calculated from repeat measurements of the same peptide sequence, and links to other proteomics and immunology databases. The SysteMHC Atlas project was created and will be further expanded using a uniform and open computational pipeline that controls the quality of peptide identifications and peptide annotations. Thus, the SysteMHC Atlas disseminates quality controlled immunopeptidomic information to the public domain and serves as a community resource toward the generation of a high-quality comprehensive map of the human immunopeptidome and the support of consistent measurement of immunopeptidomic sample cohorts