Background: Postmortem and in vivo imaging data support the hypothesis that premature myelin breakdown and subsequent homeostatic remyelination attempts with increased oligodendrocyte and iron levels may contribute to Huntington's Disease (HD) pathogenesis and the symmetrical progress of neuronal loss from earlier-myelinating striatum to later-myelinating regions. A unique combination of in vivo tissue integrity and iron level assessments was used to examine the hypothesis.
Methods: A method that uses two Magnetic resonance imaging (MRI) instruments operating at different field-strengths was used to quantify the iron content of ferritin molecules (ferritin iron) as well as tissue integrity in eight regions in 11 HD and a matched group of 27 healthy control subjects. Three white matter regions were selected based on their myelination pattern (early to later-myelinating) and fiber composition. These were frontal lobe white matter (Fwm) and splenium and genu of the corpus callosum (Swm and Gwm). In addition, gray matter structures were also chosen based on their myelination pattern and fiber composition. Three striatum structures were assessed [caudate, putamen, and globus pallidus (C, P, and G)] as well as two comparison gray matter regions that myelinate later in development and are relatively spared in HD [Hippocampus (Hipp) and Thalamus (Th)].
Results: Compared to healthy controls, HD ferritin iron levels were significantly increased in striatum C, P, and G, decreased in Fwm and Gwm, and were unchanged in Hipp, Th, and Swm. Loss of tissue integrity was observed in C, P, Fwm, and especially Swm but not Hipp, Th, G, or Gwm. This pattern of findings was largely preserved when a small subset of HD subjects early in the disease process was examined.
Conclusions: The data suggest early in the HD process, myelin breakdown and changes in ferritin iron distribution underlie the pattern of regional toxicity observed in HD. Prospective studies are needed to verify myelin breakdown and increased iron levels are causal factors in HD pathogenesis. Tracking the effects of novel interventions that reduce myelin breakdown and iron accumulation in preclinical stages of HD could hasten the development of preventive treatments.
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http://dx.doi.org/10.1007/s11064-007-9352-7 | DOI Listing |
J Neuroophthalmol
December 2024
Experimental and Clinical Research Center (FCO, HGZ, SM, CB, ESA, CC, FP, AUB), Max Delbrück Center for Molecular Medicine and Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany; NeuroCure Clinical Research Center (FCO, HGZ, SM, CB, ESA, CC, FP, AUB), Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany; Department of Neurology (AJG), University of California San Francisco, San Francisco, California; Neurology (RM, ACC), Multiple Sclerosis, Myelin Disorders and Neuroinflammation Pierre Wertheimer Neurological Hospital, Hospices Civils de Lyon, France; Centre d'Esclerosi Múltiple de Catalunya (Cemcat) (ACC), Department of Neurology/Neuroimmunology, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain; Experimental Neurophysiology Unit (LL, MP, M. Radaelli), Institute of Experimental Neurology (INSPE) Scientific Institute, Hospital San Raffaele and University Vita-Salute San Raffaele, Milan, Italy; Hospital Clinic of Barcelona-Institut d'Investigacions (PV, BS-D, EHM-L), Biomèdiques August Pi Sunyer, (IDIBAPS), Barcelona, Spain; CIEM MS Research Center (MAL-P, MAF), University of Minas Gerais, Medical School, Belo Horizonte, Brazil; Department of Neurology (OA, M. Ringelstein, PA), Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany; Department of Neurology (M. Ringelstein), Centre for Neurology and Neuropsychiatry, LVR Klinikum, Heinrich Heine University Düsseldorf, Düsseldorf, Germany; Department of Medicine (MRY), Harbor-University of California at Los Angeles (UCLA) Medical Center, and Lundquist Institute for Biomedical Innovation, Torrance, California; Department of Medicine (MRY), David Geffen School of Medicine at UCLA, Los Angeles, California; Departments of Ophthalmology and Visual Sciences (TJS), Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan; Division of Metabolism, Endocrine and Diabetes (TJS, LC), Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan; Department of Neurology (FP), Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany; and Department of Neurology (AUB), University of California, Irvine, California.
Cell Mol Biol (Noisy-le-grand)
January 2025
Department of Pharmacology, Faculty of Pharmacy, Mersin University, Mersin, Türkiye.
J Neurochem
January 2025
State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
Severe trauma frequently leads to nerve damage. Peripheral nerves possess a degree of regenerative ability, and actively promoting their recovery can help restore the sensory and functional capacities of tissues. The neuropeptide calcitonin gene-related peptide (CGRP) is believed to regulate the repair of injured peripheral nerves, with neuronal transient receptor potential vanilloid type 1 (TRPV1) potentially serving as a crucial upstream factor.
View Article and Find Full Text PDFCells
January 2025
Department of Physical Medicine and Rehabilitation, University of Missouri School of Medicine, Columbia, MO 65211, USA.
Amyotrophic Lateral Sclerosis (ALS) is a complex neurodegenerative disease primarily affecting motor neurons, leading to progressive muscle atrophy and paralysis. This review explores the role of Schwann cells in ALS pathogenesis, highlighting their influence on disease progression through mechanisms involving demyelination, neuroinflammation, and impaired synaptic function. While Schwann cells have been traditionally viewed as peripheral supportive cells, especially in motor neuron disease, recent evidence indicates that they play a significant role in ALS by impacting motor neuron survival and plasticity, influencing inflammatory responses, and altering myelination processes.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563000, China.
As one of the most commonly used general anesthetics (GAs) in surgery, numerous studies have demonstrated the detrimental effects of sevoflurane exposure on myelination in the developing and elderly brain. However, the impact of sevoflurane exposure on intact myelin structure in the adult brain is barely discovered. Here, we show that repeated sevoflurane exposure, but not single exposure, causes hypomyelination and abnormal ultrastructure of myelin sheath in the prefrontal cortex (PFC) of adult male mice, which is considered as a critical brain region for general anesthesia mediated consciousness change.
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