p62 Pathology Model in the Rat Substantia Nigra with Filamentous Inclusions and Progressive Neurodegeneration

• Published in: PloS one 2017-01, Vol.12 (1), p.e0169291
• Main Authors: Jackson, Kasey L, Lin, Wen-Lang, Miriyala, Sumitra, Dayton, Robert D, Panchatcharam, Manikandan, McCarthy, Kevin J, Castanedes-Casey, Monica, Dickson, Dennis W, Klein, Ronald L
• Format: Article
• Language: English
• Subjects: Amyotrophic lateral sclerosis; Amyotrophic Lateral Sclerosis - genetics; Amyotrophic Lateral Sclerosis - pathology; Analysis; Animals; Autophagy; Autophagy (Cytology); Behavior; Biodegradation; Biology; Biology and Life Sciences; Brain; Cell culture; Cell death; Cristae; Development and progression; Diagnosis; Diagnostic systems; Disease; Disease Models, Animal; Dissociation; Dopamine; Dopamine receptors; Electron microscopy; Female; Filaments; Fluorescence; Gene transfer; Health sciences; HEK293 Cells; Humans; Inclusion bodies; Inclusion Bodies - genetics; Inclusion Bodies - pathology; Inclusions; Inflammatory diseases; Lesions; Medicine and Health Sciences; Microscopy; Mitochondria; Musculoskeletal diseases; Myositis; Myositis, Inclusion Body - genetics; Myositis, Inclusion Body - pathology; Neurodegeneration; Neurodegenerative diseases; Neurodegenerative Diseases - genetics; Neurodegenerative Diseases - pathology; Neurological diseases; Neurons; Neuropathology; Neurosciences; Pathology; Phagocytosis; Pharmacology; Physical Sciences; Plasmids; Proteins; Rats; Rats, Sprague-Dawley; Rats, Transgenic; Rodents; Rotational behavior; Sequestosome-1 Protein - genetics; Sequestosome-1 Protein - physiology; Substantia nigra; Substantia Nigra - metabolism; Tissues; Toxicology; Ubiquitin; Viruses
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0169291

One of the proteins most frequently found in neuropathological lesions is the ubiquitin binding protein p62 (sequestosome 1). Post-mortem analysis of p62 is a defining diagnostic marker in several neurodegenerative diseases including amyotrophic lateral sclerosis and inclusion body myositis. Since p62 functions in protein degradation pathways including autophagy, the build-up of p62-positive inclusions suggests defects in protein clearance. p62 was expressed unilaterally in the rat substantia nigra with an adeno-associated virus vector (AAV9) in order to study p62 neuropathology. Inclusions formed within neurons from several days to several weeks after gene transfer. By electron microscopy, the inclusions were found to contain packed 10 nm thick filaments, and mitochondria cristae structure was disrupted, resulting in the formation of empty spaces. In corollary cell culture transfections, p62 clearly impaired mitochondrial function. To probe for potential effects on macroautophagy, we co-expressed p62 with a double fluorescent tagged reporter for the autophagosome protein LC3 in the rat. p62 induced a dramatic and specific dissociation of the two tags. By 12 weeks, a rotational behavior phenotype manifested, consistent with a significant loss of dopaminergic neurons analyzed post-mortem. p62 overexpression resulted in a progressive and robust pathology model with neuronal inclusions and neurodegeneration. p62 gene transfer could be a novel methodological probe to disrupt mitochondrial function or autophagy in the brain and other tissues in vivo.