• Mitochondrial DNA depletion in sporadic inclusion body myositis 

      Bhatt, Padmanabh S.; Tzoulis, Charalampos; Balafkan, Novin; Miletic, Hrvoje; Tran, Gia Tuong Thi; Sanaker, Petter Schandl; Bindoff, Laurence (Peer reviewed; Journal article, 2019)
      Sporadic inclusion body myositis (sIBM) is a late onset disorder of unkown aetiology. Mitochondrial changes such as cytochrome oxidase deficient fibres are a well recognised feature and mitochondrial DNA (mtDNA) deletions ...
    • Mitochondrial respiratory chain deficiency correlates with the severity of neuropathology in sporadic Creutzfeldt-Jakob disease 

      Flønes, Irene Hana; Ricken, Gerda; Klotz, Sigrid; Lang, Alexandra; Ströbel, Thomas; Dölle, Christian; Kovacs, Gabor G.; Tzoulis, Charalampos (Journal article; Peer reviewed, 2020)
      Mitochondrial dysfunction has been implicated in multiple neurodegenerative diseases but remains largely unexplored in Creutzfeldt-Jakob disease. Here, we characterize the mitochondrial respiratory chain at the individual ...
    • Mitochondrial respiratory chain dysfunction—A hallmark pathology of idiopathic Parkinson’s disease? 

      Flønes, Irene Hana; Tzoulis, Charalampos (Journal article; Peer reviewed, 2022)
      Parkinson’s disease (PD) is the most common age-dependent neurodegenerative synucleinopathy. Loss of dopaminergic neurons of the substantia nigra pars compacta, together with region- and cell-specific aggregations of ...
    • Molecular pathogenesis of polymerase gamma-related neurodegeneration 

      Tzoulis, Charalampos; Tran, Gia Tuong Thi; Coxhead, Jonathan; Bertelsen, Bjørn; Lilleng, Peer Kåre; Balafkan, Novin; Payne, Brendan; Miletic, Hrvoje; Chinnery, Patrick F.; Bindoff, Laurence (Peer reviewed; Journal article, 2014-07)
      Objective: Polymerase gamma (POLG) mutations are a common cause of mitochondrial disease and have also been linked to neurodegeneration and aging. We studied the molecular mechanisms underlying POLG-related neurodegeneration ...
    • MRI characterisation of adult onset alpha-methylacyl-coA racemase deficiency diagnosed by exome sequencing 

      Haugarvoll, Kristoffer; Johansson, Stefan; Tzoulis, Charalampos; Haukanes, Bjørn Ivar; Bredrup, Cecilie; Neckelmann, Gesche; Boman, Helge; Knappskog, Per; Bindoff, Laurence (Peer reviewed; Journal article, 2013-01-03)
      Background: Correct diagnosis is pivotal to understand and treat neurological disease. Herein, we report the diagnostic work-up utilizing exome sequencing and the characterization of clinical features and brain MRI in two ...
    • A multicenter study on Leigh syndrome: disease course and predictors of survival 

      Sofou, Kalliopi; De Coo, Irenaeus F. M.; Isohanni, Pirjo; Ostergaard, Elsebet; Naess, Karin; De Meirleir, Linda; Tzoulis, Charalampos; Uusimaa, Johanna; De Angst, Isabell B.; Lönnqvist, Tuula; Pihko, Helena; Mankinen, Katariina; Bindoff, Laurence; Tulinius, Már; Darin, Niklas (Peer reviewed; Journal article, 2014-04-15)
      Background: Leigh syndrome is a progressive neurodegenerative disorder, associated with primary or secondary dysfunction of the mitochondrial oxidative phosphorylation. Despite the fact that Leigh syndrome is the most ...
    • The NADPARK study: A randomized phase I trial of nicotinamide riboside supplementation in Parkinson’s disease 

      Brakedal, Brage; Dölle, Christian; Riemer, Frank; Ma, Yilong; Nido, Gonzalo Sanchez; Skeie, Geir Olve; Craven, Alexander R.; Schwarzlmüller, Thomas; Brekke, Njål; Diab, Joseph; Sverkeli, Lars Jansen; Skjeie, Vivian; Varhaug, Kristin Nielsen; Tysnes, Ole-Bjørn; Peng, Shichun; Haugarvoll, Kristoffer; Ziegler, Mathias; Grüner, Renate; Eidelberg, David; Tzoulis, Charalampos (Journal article; Peer reviewed, 2022)
      We conducted a double-blinded phase I clinical trial to establish whether nicotinamide adenine dinucleotide (NAD) replenishment therapy, via oral intake of nicotinamide riboside (NR), is safe, augments cerebral NAD levels, ...
    • A nationwide study of the incidence, prevalence and mortality of Parkinson’s disease in the Norwegian population 

      Brakedal, Brage; Toker, Lilah; Haugarvoll, Kristoffer; Tzoulis, Charalampos (Journal article; Peer reviewed, 2022)
      Epidemiological studies of Parkinson’s disease (PD) show variable and partially conflicting findings with regard to incidence, prevalence, and mortality. These differences are commonly attributed to technical and methodological ...
    • Nicotinamide riboside supplementation is not associated with altered methylation homeostasis in Parkinson's disease 

      Gaare, Johannes Jernqvist; Dölle, Christian; Brakedal, Brage; Brügger, Kim; Haugarvoll, Kristoffer; Sanchez Nido, Gonzalo; Tzoulis, Charalampos (Journal article; Peer reviewed, 2023)
      Replenishing nicotinamide adenine dinucleotide (NAD) via supplementation of nicotinamide riboside (NR) has been shown to confer neuroprotective effects in models of aging and neurodegenerative diseases, including Parkinson’s ...
    • Not every estimate counts – evaluation of cell composition estimation approaches in brain bulk tissue data 

      Toker, Lilah; Sanchez Nido, Gonzalo; Tzoulis, Charalampos (Journal article; Peer reviewed, 2023-06-07)
      Background: Variation in cell composition can dramatically impact analyses in bulk tissue samples. A commonly employed approach to mitigate this issue is to adjust statistical models using estimates of cell abundance derived ...
    • NSAID use is not associated with Parkinson's disease incidence: A Norwegian Prescription Database study 

      Brakedal, Brage; Tzoulis, Charalampos; Tysnes, Ole-Bjørn; Haugarvoll, Kristoffer (Journal article; Peer reviewed, 2021-09-07)
      Objective: Whether use of nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the risk of incident Parkinson’s disease (PD) remains unresolved. Here, we employed the Norwegian Prescription Database to examine whether NSAID ...
    • PNKP Mutations Identified by Whole-Exome Sequencing in a Norwegian Patient with Sporadic Ataxia and Edema 

      Tzoulis, Charalampos; Sztromwasser, Pawel Szymon; Johansson, Stefan; Gjerde, Ivar Otto; Knappskog, Per; Bindoff, Laurence (Journal article, 2017-02)
      We identified PNKP mutations in a Norwegian woman with AOA. This patient had the typical findings with cognitive dysfunction, peripheral neuropathy, cerebellar dysarthria, horizontal nystagmus, oculomotor apraxia, and ...
    • Poly-ADP-ribose assisted protein localization resolves that DJ-1, but not LRRK2 or α-synuclein, is localized to the mitochondrial matrix 

      Osuagwu, Nelson Uchechukwu; Dölle, Christian; Tzoulis, Charalampos (Peer reviewed; Journal article, 2019)
      Several proteins linked to familial Parkinson disease have been associated with mitochondrial (dys-)function and have been described to reside within mitochondria. The putative mitochondrial and sub-mitochondrial localization ...
    • Progressive striatal necrosis associated with anti-NMDA receptor antibodies 

      Tzoulis, Charalampos; Vedeler, Christian A.; Haugen, Mette; Storstein, Anette; Tran, Gia Tuong Thi; Gjerde, Ivar Otto; Biermann, Martin; Schwarzlmüller, Thomas; Bindoff, Laurence (Peer reviewed; Journal article, 2013-05-31)
      Background: We report a case of childhood onset, generalized dystonia due to slowly progressive bilateral striatal necrosis associated with anti-N-methyl-D-aspartate receptor (NMDAR) antibodies. This clinical phenotype has ...
    • Real-World Dosing of OnabotulinumtoxinA and IncobotulinumtoxinA for Cervical Dystonia and Blepharospasm: Results from TRUDOSE and TRUDOSE II 

      Kent, Ruth; Robertson, Adrian; Quiñones Aguilar, Sandra; Tzoulis, Charalampos; Maltman, John (Journal article; Peer reviewed, 2021)
      The real-world use of onabotulinumtoxinA and incobotulinumtoxinA for cervical dystonia and blepharospasm treatment was assessed in two separate retrospective studies using identical protocols (TRUDOSE and TRUDOSE II). The ...
    • Spastic paraplegia type 7 is associated with multiple mitochondrial DNA deletions 

      Wedding, Iselin Marie; Koht, Jeanette; Tran, Gia Tuong Thi; Misceo, Doriana; Selmer, Kaja Kristine; Holmgren, Asbjørn; Frengen, Eirik; Bindoff, Laurence; Tallaksen, Chantal; Tzoulis, Charalampos (Peer reviewed; Journal article, 2014-01-22)
      Spastic paraplegia 7 is an autosomal recessive disorder caused by mutations in the gene encoding paraplegin, a protein located at the inner mitochondrial membrane and involved in the processing of other mitochondrial ...
    • Targeting NAD+ in translational research to relieve diseases and conditions of metabolic stress and ageing 

      Gilmour, Brian Christopher; Gudmundsrud, Ruben; Frank, Johannes; Hov, Amund; Hindkjær Lautrup, Sofie; Aman, Yahyah; Røsjø, Helge; Brenner, Charles; Ziegler, Mathias; Tysnes, Ole-Bjørn; Tzoulis, Charalampos; Omland, Torbjørn; Søraas, Arne Vasli; Holmøy, Trygve; Bergersen, Linda Hildegard; Storm-Mathisen, Jon; Nilsen, Hilde; Fang, Evandro Fei (Journal article; Peer reviewed, 2020)
      Nicotinamide adenine dinucleotide (NAD+) plays a fundamental role in life and health through the regulation of energy biogenesis, redox homeostasis, cell metabolism, and the arbitration of cell survival via linkages to ...
    • Ultra-deep whole genome bisulfite sequencing reveals a single methylation hotspot in human brain mitochondrial DNA 

      Guitton, Romain Guillaume Bernard; Dölle, Christian; Alves, Guido Werner; Tysnes, Ole-Bjørn; Nido, Gonzalo Sanchez; Tzoulis, Charalampos (Journal article; Peer reviewed, 2022)
      While DNA methylation is established as a major regulator of gene expression in the nucleus, the existence of mitochondrial DNA (mtDNA) methylation remains controversial. Here, we characterized the mtDNA methylation landscape ...
    • Using urine to diagnose large-scale mtDNA deletions in adult patients 

      Varhaug, Kristin Nielsen; Sanchez Nido, Gonzalo; de Coo, Irenaeus; Isohanni, Pirjo; Suomalainen, Anu; Tzoulis, Charalampos; Knappskog, Per; Bindoff, Laurence (Journal article; Peer reviewed, 2020)
      Objective: The aim of this study was to evaluate if urinary sediment cells offered a robust alternative to muscle biopsy for the diagnosis of single mtDNA deletions. Methods: Eleven adult patients with progressive ...