Iron and Oxidative Stress in Parkinson's Disease: An Observational Study of Injury Biomarkers

• Published in: PloS one 2016-01, Vol.11 (1), p.e0146129
• Main Authors: Medeiros, Marcio S, Schumacher-Schuh, Arthur, Cardoso, Andreia Machado, Bochi, Guilherme Vargas, Baldissarelli, Jucimara, Kegler, Aline, Santana, Daniel, Chaves, Carolina Maria Martins Behle Soares, Schetinger, Maria Rosa Chitolina, Moresco, Rafael Noal, Rieder, Carlos R M, Fighera, Michele Rechia
• Format: Article
• Language: English
• Subjects: 5'-Nucleotidase - blood; Adenosine; Adenosine deaminase; Adenosine Deaminase - blood; Adenosine Triphosphatases - blood; Advanced Oxidation Protein Products - blood; Aged; Antioxidants; Ascorbic acid; Ascorbic Acid - blood; Biochemistry; Biomarkers; Biomarkers - blood; Brain research; Cancer; Case-Control Studies; Catalase; Catalase - blood; Dopamine receptors; Dopaminergic Neurons - metabolism; Dopaminergic Neurons - pathology; Female; Ferritin; Ferritins - blood; Health sciences; Homeostasis; Hospitals; Humans; Inflammation; Iron; Iron - blood; Ischemia; Life sciences; Male; Malnutrition; Medical research; Middle Aged; Movement disorders; Neurodegeneration; Neurodegenerative diseases; Neurology; Nucleotidase; Observational studies; Oxidation; Oxidation-Reduction; Oxidative Stress; Oxygen; Parameter identification; Parkinson Disease - blood; Parkinson Disease - pathology; Parkinson's disease; Pars Compacta - metabolism; Pars Compacta - pathology; Pathogenesis; Patients; Peroxidase; Peroxidase - blood; Protein thiols; Proteins; Reactive nitrogen species; Reactive Nitrogen Species - blood; Reactive oxygen species; Reactive Oxygen Species - blood; Recovery (Medical); Rodents; Serum levels; Substantia nigra; Sulfhydryl Compounds - blood; Superoxide dismutase; Superoxide Dismutase - blood; Thiobarbituric acid; Thiobarbituric Acid Reactive Substances - metabolism; Thiols; Transferrin; Transferrin - metabolism; Vitamin C
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0146129

Parkinson's disease (PD) is characterized by progressive motor impairment attributed to progressive loss of dopaminergic neurons in the substantia nigra (SN) pars compacta. In addition to an accumulation of iron, there is also an increased production of reactive oxygen/nitrogen species (ROS/RNS) and inflammatory markers. These observations suggest that iron dyshomeostasis may be playing a key role in neurodegeneration. However, the mechanisms underlying this metal-associated oxidative stress and neuronal damage have not been fully elucidated. To determine peripheral levels of iron, ferritin, and transferrin in PD patients and its possible relation with oxidative/nitrosative parameters, whilst attempting to identify a profile of peripheral biomarkers in this neurological condition. Forty PD patients and 46 controls were recruited to compare serum levels of iron, ferritin, transferrin, oxidative stress markers (superoxide dismutase (SOD), catalase (CAT), nitrosative stress marker (NOx), thiobarbituric acid reactive substances (TBARS), non-protein thiols (NPSH), advanced oxidation protein products (AOPP), ferric reducing ability of plasma (FRAP) and vitamin C) as well as inflammatory markers (NTPDases, ecto-5'-nucleotidase, adenosine deaminase (ADA), ischemic-modified albumin (IMA) and myeloperoxidase). Iron levels were lower in PD patients, whereas there was no difference in ferritin and transferrin. Oxidative stress (TBARS and AOPP) and inflammatory markers (NTPDases, IMA, and myeloperoxidase) were significantly higher in PD, while antioxidants FRAP, vitamin C, and non-protein thiols were significantly lower in PD. The enzymes SOD, CAT, and ecto-5'-nucleotidase were not different among the groups, although NOx and ADA levels were significantly higher in the controls. Our data corroborate the idea that ROS/RNS production and neuroinflammation may dysregulate iron homeostasis and collaborate to reduce the periphery levels of this ion, contributing to alterations observed in the pathophysiology of PD.