Abnormal neurofilament inclusions and segregations in dorsal root ganglia of a Charcot-Marie-Tooth type 2E mouse model

• Published in: PloS one 2017-06, Vol.12 (6), p.e0180038-e0180038
• Main Authors: Zhao, Jian, Brown, Kristy, Liem, Ronald K H
• Format: Article
• Language: English
• Subjects: Aluminum; Animals; Ataxia; Axons; Axons - metabolism; Biology; Biology and Life Sciences; Cerebellum; Cerebellum - metabolism; Cerebellum - pathology; Charcot-Marie-Tooth disease; Charcot-Marie-Tooth Disease - metabolism; Charcot-Marie-Tooth Disease - pathology; Disease; Disease Models, Animal; Dorsal root ganglia; Embryos; Fluorescent antibody technique; Ganglia; Ganglia, Spinal - metabolism; Ganglia, Spinal - pathology; Ganglia, Spinal - ultrastructure; Genes; Immunofluorescence; Inclusion Bodies - metabolism; Inclusion Bodies - pathology; Inclusion Bodies - ultrastructure; Inclusions; Information dissemination; Intermediate Filaments - metabolism; Intermediate Filaments - pathology; Intermediate Filaments - ultrastructure; Labeling; Medicine and Health Sciences; Mice; Motor neurons; Motor task performance; Mutation; Neurofilament Proteins - metabolism; Neurofilaments; Neurogenesis; Neurons; Neurosciences; Organelles; Pathology; Peripheral neuropathy; Polypeptides; Proteins; Research and Analysis Methods; Rodents; Rope; Segregations; Spinal cord; Spinal Cord - metabolism; Spinal Cord - pathology; Surgeons; Transcription; Transgenic animals
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0180038

Charcot-Marie-Tooth (CMT) disease or hereditary motor and sensory neuropathy is the most prevalent inherited peripheral neuropathy and is associated with over 90 causative genes. Mutations in neurofilament light polypeptide gene, NEFL cause CMT2E, an axonal form of CMT that results in abnormal structures and/or functions of peripheral axons in spinal cord motor neurons and dorsal root ganglion neurons. We have previously generated and characterized a knock-in mouse model of CMT2E with the N98S mutation in Nefl that presented with multiple inclusions in spinal cord neurons. In this report, we conduct immunofluorescence studies of cultured dorsal root ganglia (DRG) from NeflN98S/+ mice, and show that inclusions found in DRG neurites can occur in embryonic stages. Ultrastructural analyses reveal that the inclusions are disordered neurofilaments packed in high density, segregated from other organelles. Immunochemical studies show decreased NFL protein levels in DRG, cerebellum and spinal cord in NeflN98S/+ mice, and total NFL protein pool is shifted toward the triton-insoluble fraction. Our findings reveal the nature of the inclusions in NeflN98S/+ mice, provide useful information to understand mechanisms of CMT2E disease, and identify DRG from NeflN98S/+ mice as a useful cell line model for therapeutic discoveries.